WO2025223491A1

WO2025223491A1 - A composite assembly, a preparation method thereof, and a window assembly comprising the same

Info

Publication number: WO2025223491A1
Application number: PCT/CN2025/090802
Authority: WO
Inventors: Daming Li; Patrick Gayout; Lu Wang; Ljiljana DURDEVIC
Original assignee: Saint Gobain Sekurit France
Current assignee: Saint Gobain Sekurit France
Priority date: 2024-04-24
Filing date: 2025-04-24
Publication date: 2025-10-30
Anticipated expiration: 2026-10-24
Also published as: CN119928360A

Abstract

The present disclosure relates to a composite assembly comprising: a transparent substrate, a semi-reflective layer, and a light-absorbing substrate; wherein the semi-reflective layer is located between the transparent substrate and the light-absorbing substrate, the semi-reflective layer has a textured first surface and a textured second surface, the transparent substrate is in contact with the first surface of the semi-reflective layer, the contacting surface of the transparent substrate is textured, and the texture is complementary to the texture of the first surface of the semi-reflective layer; and the light-absorbing substrate is in contact with the second surface of the semi-reflective layer, the contacting surface of the light-absorbing substrate is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer; the transparent substrate is closer to an external visible light source than the light-absorbing substrate.

Description

A Composite Assembly, a Preparation Method Thereof, and a Window Assembly Comprising the Same

Technical Field

The present disclosure relates to the field of materials, and in particular, to a composite assembly comprising a semi-reflective layer, a preparation method thereof, and a window assembly comprising the composite assembly.

Background

Smart window products have a wide range of applications in the fields of construction, automobiles, materials, etc. In particular, with the rapid development of the field of smart electric vehicles, the demand for smart window applications also increases accordingly. Under such market demand, multi-functional panoramic vehicle skylights and windows have emerged.

Since the vehicle skylight is transparent and faces external sunlight directly, special considerations need to be given to the design of the window structure and the selection of related materials in order to maintain thermal comfort of the environment inside the vehicle, ensure good light inside the vehicle, and provide an excellent projection display effect on this basis.

In order to obtain good interior light and achieve interior projection effect, a vehicle skylight in the prior art typically employs a dark adhesive layer (e.g., PVB (polyvinyl butyral) ) to absorb most visible light, and employs a projection display film and an infrared reflective coating to achieve projection display and thermal comfort control effect. However, such window design has obvious drawbacks. On the one hand, visible light absorbed by the dark adhesive layer leads to secondary emission issues, and since visible light accounts for the majority (about 50%) of the total amount of solar energy on earth, it is difficult for such design to control the total solar transmittance within 10%. On the other hand, the projection display film and the infrared reflective coating are costly and unfavorable for cost reduction. Therefore, the conventional vehicle skylight and window design have limitations in environmental thermal comfort control and cost, so further research and development efforts still need to be performed to obtain a window material that combines thermal comfort, projection function and cost saving.

Summary

In one aspect, provided herein is a composite assembly comprising: a transparent substrate, a semi-reflective layer, and a light-absorbing substrate; wherein the semi-reflective layer is located between the transparent substrate and the light-absorbing substrate, the semi-reflective layer has a textured first surface and a textured second surface, the transparent substrate is in contact with the first surface of the semi-reflective layer, the contacting surface of the transparent substrate is textured, and the texture is complementary to the texture of the first surface of the semi-reflective layer; and the light-absorbing substrate is in contact with the second surface of the semi-reflective layer, the contacting surface of the light-absorbing substrate is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer; the transparent substrate is closer to an external visible light source than the light-absorbing substrate.

In an embodiment, the composite assembly is used as a projection screen, and the light-absorbing substrate faces towards a projection light for forming a projection image on a side of the semi-reflective layer facing towards the light-absorbing substrate.

In an embodiment, the composite assembly consists of the transparent substrate, the semi-reflective layer, and the light-absorbing substrate.

In an embodiment, the composite assembly has a transmittance of about 0.5%to about 10%, preferably about 0.5%to about 2.5%, for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate.

In an embodiment, the composite assembly has a diffuse reflectance of about 10%to about 25%for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate.

In an embodiment, the composite assembly has a diffuse reflectance of about 40%to about 90%for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate.

In an embodiment, the composite assembly has a total solar transmittance of about 10%or less for sunlight incident from the side of the transparent substrate facing away from the light-absorbing substrate.

In an embodiment, the composite assembly has a solar direct reflectance (RDS) of about 55%or more for diffuse reflection of sunlight incident from the side of the transparent substrate facing away from the light-absorbing substrate.

In an embodiment, the composite assembly has a diffuse reflectance of about 55%to about 95%for near-infrared light incident from the side of the transparent substrate facing away from the light-absorbing substrate.

In an embodiment, the composite assembly has a haze of about 10%or less, preferably 5%or less.

In an embodiment, the diffuse reflectance of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is greater than the diffuse reflectance of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate.

In an embodiment, the transmittance of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is greater than the transmittance of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate.

In an embodiment, the diffuse reflectance of the semi-reflective layer for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate is greater than the diffuse reflectance of the composite assembly for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate.

In an embodiment, the reflection and the transmission of the composite assembly for visible light satisfy the following relationship,

wherein R4 represents the diffuse reflectance of the semi-reflective layer for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate, T2 represents the transmittance of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate.

In an embodiment, the textured first surface is parallel to the textured second surface (the textured surfaces being parallel means that the textures are parallel to each other) .

In another embodiment, the textured first surface and/or the textured second surface has a root mean square slope of profile of about 1° to about 20°.

In an embodiment, the light-absorbing substrate comprises at least one light-absorbing layer, one surface of one of the light-absorbing layer (s) is in contact with the second surface of the semi-reflective layer, the contacting surface of said one of the light-absorbing layer (s) is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer.

In an embodiment, the light-absorbing substrate comprises at least one light-absorbing layer and at least one transparent layer, one surface of one of the light-absorbing layer (s) or one of the transparent layer (s) is in contact with the second surface of the semi-reflective layer, the contacting surface of said one of the light-absorbing layer (s) or said one of the transparent layer (s) is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer.

In an embodiment, the transparent substrate comprises at least one transparent layer, wherein one surface of one of the transparent layer (s) is in contact with the first surface of the semi-reflective layer, the contacting surface of said one of the transparent layer (s) is textured, and the texture is complementary to the texture of the first surface of the semi-reflective layer, and all the layers comprised in the transparent substrate are transparent layers.

In an embodiment, the light-absorbing substrate comprises any one of a glass substrate, an adhesive layer, a switchable film, a polymeric layer and a film substrate layer or any combination thereof.

In an embodiment, the transparent substrate comprises any one of a glass substrate, an adhesive layer, a polymeric layer, and a film substrate layer or any combination thereof.

In an embodiment, the semi-reflective layer is a single layer or a multilayer stack, the single layer is a metal layer or a metal alloy layer, the multilayer stack comprises at least one metal layer or metal alloy layer, each of the contacting surfaces of each layer with its adjacent layers in the multilayer stack is textured, and the texture of each of the contacting surfaces is complementary to the texture of its adjacent contacting surface.

In an embodiment, a first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is a glass substrate, and a first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a polymeric layer or an adhesive layer.

In an embodiment, a first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is a polymeric layer, and a first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a polymeric layer or an adhesive layer or a glass substrate.

In an embodiment, a first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is an adhesive layer, and a first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a polymeric layer or a glass substrate.

In an embodiment, the light-absorbing substrate further comprises a second light-absorbing layer or transparent layer, which is in contact with the first transparent layer or light-absorbing layer of the light-absorbing substrate on a side of the first transparent layer or light-absorbing layer of the light-absorbing substrate facing away from the semi-reflective layer, when the first transparent layer or light-absorbing layer of the light-absorbing substrate is a polymeric layer, the second light-absorbing layer or transparent layer is an adhesive layer, optionally, the light-absorbing substrate further comprises a glass substrate or a switchable film in contact with the adhesive layer on a side of the adhesive layer facing away from the polymeric layer.

In an embodiment, the light-absorbing substrate further comprises a second light-absorbing layer or transparent layer, which is in contact with the first transparent layer or light-absorbing layer of the light-absorbing substrate on a side of the first transparent layer or light-absorbing layer of the light-absorbing substrate facing away from the semi-reflective layer; when the first transparent layer or light-absorbing layer of the light-absorbing substrate is a polymeric layer, the second light-absorbing layer or transparent layer is a film substrate layer; optionally, the light-absorbing substrate further comprises an adhesive layer in contact with the film substrate layer on a side of the film substrate layer facing away from the polymeric layer, further optionally, the light-absorbing substrate further comprises a glass substrate or a switchable film in contact with the adhesive layer on a side of the adhesive layer facing away from the film substrate layer.

In an embodiment, the light-absorbing substrate further comprises a second light-absorbing layer or transparent layer, which is in contact with the first transparent layer or light-absorbing layer of the light-absorbing substrate on a side of the first transparent layer or light-absorbing layer of the light-absorbing substrate facing away from the semi-reflective layer, when the first transparent layer or light-absorbing layer of the light-absorbing substrate is an adhesive layer, the second light-absorbing layer or transparent layer is a glass substrate or a switchable film.

In an embodiment, the transparent substrate further comprises a second transparent layer, which is in contact with the first transparent layer of the transparent substrate on a side of the first transparent layer of the transparent substrate facing away from the semi-reflective layer, when the first transparent layer of the transparent substrate is a polymeric layer, the second transparent layer is an adhesive layer, optionally, the transparent substrate further comprises a glass substrate in contact with the adhesive layer on a side of the adhesive layer facing away from the polymeric layer.

In an embodiment, the transparent substrate further comprises a second transparent layer, which is in contact with the first transparent layer of the transparent substrate on a side of the first transparent layer of the transparent substrate facing away from the semi-reflective layer; when the first transparent layer of the transparent substrate is a polymeric layer, the second transparent layer is a film substrate layer; optionally, the transparent substrate further comprises an adhesive layer in contact with the film substrate layer on a side of the film substrate layer facing away from the polymeric layer, further optionally, the transparent substrate further comprises a glass substrate in contact with the adhesive layer on a side of the adhesive layer facing away from the film substrate layer.

In an embodiment, the transparent substrate further comprises a second transparent layer, which is in contact with the first transparent layer of the transparent substrate on a side of the first transparent layer of the transparent substrate facing away from the semi-reflective layer, when the first transparent layer of the transparent substrate is an adhesive layer, the second transparent layer is a glass substrate.

In another aspect, provided herein is a method for preparing a composite assembly according to the present disclosure, comprising providing at least one layer of one of a light-absorbing substrate and a transparent substrate, forming one surface of one layer of the at least one layer of the one of the light-absorbing substrate and the transparent substrate into a textured surface and forming a semi-reflective layer on the textured surface, forming at least one layer of the other one of the light-absorbing substrate and the transparent substrate on a surface of the semi-reflective layer facing away from the one layer of the at least one layer of the one of the light-absorbing substrate and the transparent substrate to obtain at least a portion of the composite assembly; optionally, further providing other layers of the light-absorbing substrate and the transparent substrate to obtain the composite assembly of the present disclosure. In an embodiment, the one layer of the at least one layer of the one of the light-absorbing substrate and the transparent substrate is a polymeric layer or a glass substrate.

In yet another aspect, provided herein is a window assembly comprising the composite assembly of the present disclosure.

In an embodiment, the window assembly comprises a door, a window, a curtain wall, a vehicle window glass, an airplane glass or a ship glass.

In an embodiment, the window assembly is a vehicle window glass, and the vehicle window glass comprises a rear windshield, a skylight glass, a vehicle door glass or a corner window glass, preferably a skylight glass.

In another embodiment, the transparent substrate faces towards the outside of a vehicle and the light-absorbing substrate faces towards the inside of the vehicle.

In an embodiment, the transparent substrate in the window assembly faces towards a sunlight source, and the light-absorbing substrate in the window assembly faces away from the sunlight source.

In another aspect, provided herein is a vehicle comprising the window assembly of the present disclosure, further comprising a projection device, wherein a projection light of the projection device faces towards the light-absorbing substrate of the window assembly for forming a projection image on a side of the semi-reflective layer facing towards the light-absorbing substrate.

The composite assembly of the present disclosure adopts a novel design, which comprises a transparent substrate, a semi-reflective layer and a light-absorbing substrate in sequence, wherein the semi-reflective layer has a textured surface. Through the specific reflectances (including diffuse reflectances) , transmittances and absorbances of the transparent substrate, the textured semi-reflective layer, and the light-absorbing substrate, for visible light, the composite assembly of the present disclosure achieves excellent projection display effect.

Besides, the reflection and transmission of visible light by the composite assembly of the present disclosure satisfy a specific relationship, which also helps to enable the composite assembly of the present disclosure to achieve excellent thermal comfort effect and projection display effect.

In addition to the above-mentioned thermal comfort effect and clear projection display effect, the specific diffuse reflectance, transmittance and absorbance of the composite assembly for visible light can impart more desired functions to the composite assembly of the present disclosure, such as excellent privacy effect, diversified appearance, gentle indoor light, and better thermal comfort control effect, etc.

Specifically, the composite assembly of the present disclosure employs a novel design: the total solar transmittance can be reduced to 10%or less by the high diffuse reflectance of the semi-reflective layer for visible light (which accounts for a major portion (about 50%) of the total solar energy on Earth) and by maintaining the high diffuse reflectance (e.g., about 55%or more) of the semi-reflective layer for near-infrared light (in the wavelength range of about 780 nm to about 2500 nm) in sunlight. In addition, since the reflection of visible light by the semi-reflective layer is diffuse reflection rather than specular reflection, even if the diffuse reflectance of the semi-reflective layer for visible light is high, serious light pollution will not be caused on either side of the semi-reflective layer. In addition, since the semi-reflective layer may adopt diversified designs (for example, diversified multilayer stack designs) , the composite assembly may also achieve diversified appearances. For example, the composite assembly of the present disclosure used for the vehicle window glass may match the visual effect of the vehicle body paint, so that there is no obvious color deviation between the composite assembly and the vehicle body, thereby leading to an approximately seamless visual effect for the vehicle's appearance. In addition, when used as a vehicle window glass, the composite assembly of the present disclosure can achieve projection display effect comparable to the prior art (for example, an outer transparent glass w/2Ag coating+ dark PVB+ projection display film+ inner transparent PVB+ inner transparent glass may be used in the prior art) by combining with a light-absorbing substrate facing towards the inside of a vehicle. In contrast, the composite assembly of the present disclosure has a significantly lower cost. Specifically, as mentioned above, the projection display film and the infrared reflective coating in the prior art are costly and unfavorable for cost reduction, the present disclosure integrates thermal control and projection display function into the semi-reflective layer, which can significantly reduce costs, and further cost reduction can be achieved when using, for example, an Al metal layer as the main reflective layer. Furthermore, the prior art also faces the problem of being very difficult in controlling the total solar transmittance within 10%. In addition, when the multilayer stack of the semi-reflective layer adopts an asymmetric design, even if the reflection of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is chromatic, the reflection of the composite assembly for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate may still be neutral. In addition, likewise, through the design of the multilayer stack of the semi-reflective layer, the transmission of visible light by the composite assembly can be neutral, while the reflection of visible light by the composite assembly can be chromatic. Moreover, the composite assembly has a high diffuse reflectance for visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate and a suitable diffuse reflectance for visible light incident from a side of the light-absorbing substrate facing away from the transparent substrate, which is helpful to make the composite assembly of the present disclosure achieve an “unidirectional viewing” function, which helps to ensure the privacy of the space on the side of the light-absorbing substrate, which is particularly advantageous for the application of the vehicle window glass, and can better protect the privacy of the occupant.

Brief Description of the Drawings

The detailed descriptions provided below, in combination with the accompanying drawings, will provide a more comprehensive understanding of the above and other aspects of the present disclosure. It should be noted that for the purpose of clarity, the proportions of the drawings may not be consistent without affecting understanding the present disclosure.

FIG. 1 shows a schematic diagram of an embodiment of a composite assembly of the present disclosure.

FIG. 2 is a partially enlarged view of the semi-reflective layer of FIG. 1.

FIG. 3 shows a schematic diagram of another embodiment of a composite assembly of the present disclosure.

FIG. 4 shows a schematic diagram of yet another embodiment of a composite assembly of the present disclosure.

FIG. 5a shows a schematic diagram of visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate passing through the composite assembly of the present disclosure.

FIG. 5b shows a schematic diagram of visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate being reflected (including diffusely reflected) , transmitted and absorbed by the transparent substrate, the semi-reflective layer, and the light-absorbing substrate.

FIG. 5c shows a schematic diagram of visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate being diffusely reflected by the composite assembly of the present disclosure.

FIG. 6a shows a schematic diagram of visible light incident from a side of the light-absorbing substrate facing away from the transparent substrate being diffusely reflected by the composite assembly of the present disclosure.

FIG. 6b shows a schematic diagram of visible light incident from a side of the light-absorbing substrate facing away from the transparent substrate being reflected (including diffusely reflected) , transmitted and absorbed by the light-absorbing substrate and the semi-reflective layer.

FIG. 7 shows a schematic diagram of an embodiment of a metal stack layer of a semi-reflective layer of a composite assembly of the present disclosure.

FIG. 8 shows a schematic diagram of another embodiment of a metal stack layer of a semi-reflective layer of a composite assembly of the present disclosure.

FIG. 9 shows a color chromaticity diagram of simulated reflection and transmission of the structure shown in FIG. 8 for visible light incident from one side.

FIG. 10 shows a color chromaticity diagram of simulated reflection and transmission of the structure shown in FIG. 8 for visible light incident from the other side.

FIG. 11 shows a schematic diagram of an embodiment of a composite assembly of the present disclosure.

FIG. 12 shows a schematic diagram of another embodiment of a composite assembly of the present disclosure.

FIG. 13 shows a schematic diagram of another embodiment of a composite assembly of the present disclosure.

FIG. 14 shows a schematic diagram of another embodiment of a composite assembly of the present disclosure.

Detailed Description

The present disclosure will be further described in detail below. Such description is for illustrative purposes, and is not meant to be a limitation of the present disclosure. Other advantages and effects of the present disclosure will be readily apparent to those skilled in the art from this disclosure. The present disclosure can also be implemented or applied through other different specific embodiments. Those skilled in the art can make various modifications and variations without departing from the spirit of the present disclosure.

General definitions and terms

Unless otherwise stated, all publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety.

Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by a person skilled in the art. If there is a contradiction, the definition provided in this application shall prevail.

Unless otherwise stated, all percentages, parts, proportions or the like are on a weight basis.

When an amount, concentration or other value or parameter is given as a range, a preferable range or a preferable upper limit and lower limit or a specific value, it should be understood that it corresponds to specifically revealing any range by combining any pair of upper limit of the range or preferable range value with the lower limit of any range or preferable range value, regardless of whether the range is specifically disclosed. Unless otherwise stated, the numerical ranges listed herein are intended to include the endpoints of the range and all integers and fractions within the range. The scope of the disclosure is not limited to the specific values recited when defining a range. For example, “1-20” encompasses 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 and any sub-range consisting of any two of these. For example, 2-6, 3-5, 2-10, 3-15, 4-20, 5-19, etc. For example, “3.0-5.0” encompasses 3.0, 3.2, 3.5, 3.8, 4.0, 4.2, 4.5, 4.7, 4.9, 5.0, and any sub-range subsumed by any two of these values. For example, 3.0-3.5, 3.0-4.0, 3.8-4.5, 4.0-5.0, etc.

When used with a numerical variable, the term “about” usually refers to the value of the variable and all the values of the variable within the experimental error (for example, within an average 95%confidence interval) or within ±10%of the specified value, or a wider range.

The terms “include” , “comprise” , “have” , or “involve” and other variants thereof herein are meant to be inclusive or open-ended, which do not exclude other unlisted elements or process steps. It should be understood by those skilled in the art that the above terms such as “include” encompass the meaning of “consisting of” . The expression “consisting of” excludes any element, step, or ingredient not designated. The expression “substantially consisting of” means that the scope is limited to the designated elements, steps or ingredients, plus elements, steps or ingredients that are optionally present which do not substantially affect the essential and novel feature of the claimed subject matter. It should be understood that the expression “comprise” encompasses the expressions “substantially consist of” and “consist of” .

The term “optional” or “optionally” means the event described subsequent thereto may or may not happen. This term encompasses the cases that the event may or may not happen, and that the contents are selected in an arbitrary manner.

As used herein, the term “one or more” or “at least one” refers to one, two, three, four, five, six, seven, eight, nine, or more.

In addition, if the number of parts or components of the disclosure is not indicated before, it means that there is no limitation to the number of parts or components. Therefore, it should be interpreted as including one or at least one, and the singular word form of a part or component also includes the plural, unless the numerical value clearly indicates the singular.

Unless otherwise stated, the expressions “first” , “second” and so forth as used herein are only used to distinguish various elements, components or steps without limiting the sequence and the number of assembly. Elements, components or steps as defined by the expressions “first” , “second” and so forth can be the same or different.

As used herein, the term “refractive index” has the meaning commonly understood in the field, i.e., the ratio of the propagation velocity of light in vacuum to the propagation velocity of light in a medium. Refractive index can be measured using conventional methods and equipment in the field. For example, the measurement may be performed by using a laser measurement instrument or an ellipsometer. In the present disclosure, the “refractive index” may be measured at a wavelength of 550 nm.

As used herein, the term “transmittance” may also be referred to as “light transmittance” , representing the ability of light to pass through a medium, defined as a percentage of luminous flux that passes through the medium relative to incident luminous flux. Light transmittance can be measured using conventional methods and equipment in the field. The measurement may be performed, for example, using a spectrophotometer. For example, the measurement can be performed with reference to ISO 13837. The measurement wavelength of visible light transmittance is, for example, 380-780 nm. The measurement temperature is, for example, room temperature.

As used herein, the term “diffuse reflectance” refers to the percentage of diffuse reflected luminous flux of a medium for light (including visible light as well as near-infrared light) to incident luminous flux. Diffuse reflectance of visible light can be measured using conventional methods and equipment in the field. The measurement may be performed, for example, using a spectrophotometer. For example, the measurement can be performed with reference to ISO 9050. Diffuse reflectance of near-infrared light can be measured using conventional methods and equipment in the field. The measurement may be performed, for example, using a spectrophotometer. For example, the measurement can be performed with reference to ISO 13837.

As used herein, the term “solar direct reflectance (RDS) ” refers to the ratio of solar intensity reflected (including diffusely reflected) by a medium to the incident solar intensity within the solar spectrum (300 nm to 2500 nm) range. When the SCE (Specular Component Exclude) measurement mode is adopted, the RDS of diffuse reflection of sunlight by the medium can be measured and obtained, i.e., the ratio of the solar intensity diffusely reflected by the medium to the incident solar intensity. Solar direct reflectance can be measured using conventional methods and equipment in the field. The measurement may be performed, for example, using a spectrophotometer. For example, the measurement can be performed with reference to ISO 13837.

As used herein, the term “total solar transmittance (TTS) ” refers to the ratio of the total energy of sunlight transmitted through a medium to the energy of incident sunlight within the solar spectrum (300 nm to 2500 nm) range. Total solar transmittance can be measured using conventional methods, and equipment in the field. The measurement may be performed, for example, using a spectrophotometer. For example, the measurement can be performed with reference to ISO 13837.

As used herein, the term “reflectance” refers to the percentage of reflected luminous flux of a medium for light, particularly visible light, to incident luminous flux. Reflectance of visible light can be measured using conventional methods and equipment in the field. The measurement may be performed, for example, using a spectrophotometer. For example, the measurement can be performed with reference to ISO 9050.

As used herein, the term “haze” refers to the ratio of the scattered luminous flux of incident light deviating from the normal direction through a medium (e.g., a test specimen) to the transmitted luminous flux of incident light, expressed in “%” . The scattered luminous flux that deviates 2.5 degrees or more from the incident light direction is typically used to calculate haze. Haze can be measured using conventional methods and equipment in the field. Haze may be measured, for example, using a haze meter. For example, the measurement can be performed with reference to GB2410 and/or ASTM D1003.

As used herein, the term “absorbance” is also referred to as absorptivity (can be denoted by A) , which refers to the percentage or proportion of absorption of incident light by the medium as the light is directed toward the medium. The light absorbance of the incident visible light by the medium may be measured using conventional methods and equipment in the field. Light absorbance can be measured, for example, using a spectrophotometer. For example, the measurement can be performed with reference to ISO9050 and ISO13837.

Herein, unless otherwise expressly specified, “contact” means direct contact. For example, “alayer is in contact with another layer” means that the two layers are in direct contact, and no other layer is present between the two layers.

As used herein, the term “room temperature” refers to about 20-30℃, such as about 25℃.

As used herein, the term “major surface” refers to the surface of the side of a layered material with the larger surface area. Herein, the “major surface” is also the surface in the layered material that reflects and transmits light. For example, a major surface of a light-absorbing substrate may refer to a surface that faces towards visible light and reflects or transmits visible light.

Composite Assembly

In one aspect, the present disclosure relates to a composite assembly comprising: a transparent substrate, a semi-reflective layer, and a light-absorbing substrate; wherein the semi-reflective layer is located between the transparent substrate and the light-absorbing substrate, the semi-reflective layer has a textured first surface and a textured second surface, the transparent substrate is in contact with the first surface of the semi-reflective layer, the contacting surface of the transparent substrate is textured, and the texture is complementary to the texture of the first surface of the semi-reflective layer; and the light-absorbing substrate is in contact with the second surface of the semi-reflective layer, the contacting surface of the light-absorbing substrate is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer; the transparent substrate is closer to an external visible light source than the light-absorbing substrate. That is, the transparent substrate faces towards an external visible light source, and the light-absorbing substrate faces away from an external visible light source. In a specific embodiment, the external visible light source is sunlight.

In an embodiment, the composite assembly is used as a projection screen, and the light-absorbing substrate faces towards a projection light for forming a projection image on a side of the semi-reflective layer facing towards the light-absorbing substrate. Herein, there is no limitation on the projection image, for example, it can be a static text, a number, a symbol, or a picture, or can be a dynamic video.

FIG. 1 shows an embodiment of a composite assembly of the present disclosure, wherein the composite assembly comprises Transparent substrate 101, Semi-reflective layer 102, and Light-absorbing substrate 103, wherein Semi-reflective layer 102 is located between Transparent substrate 101 and Light-absorbing substrate 103. Further, FIG. 2 shows a partially enlarged view of the semi-reflective layer of FIG. 1, wherein Semi-reflective layer 102 has textured First surface 1021 and textured Second surface 1022.

Transparent Substrate

In the composite assembly of the present disclosure, the transparent substrate refers to a substrate that is transparent to visible light (e.g., a wavelength range of 380 nm to 780 nm) . It is highly transparent and can transmit most of visible light with limited absorption for light in the visible wavelength range. In addition, in order to make full use of the high reflection of near-infrared light by the semi-reflective layer, the transparent substrate is also highly transparent to near-infrared light (for example, a wavelength range of 780 nm to 2500 nm) and can transmit most of near-infrared light with limited absorption for light in the near-infrared wavelength range.

Composition of Transparent Substrate

In an embodiment, the transparent substrate comprises any one of a glass substrate, an adhesive layer, a polymeric layer, and a film substrate layer or any combination thereof. For example, the transparent substrate may be a glass substrate, an adhesive layer, a polymeric layer, a film substrate layer, or the like. In a specific embodiment, the transparent substrate may be a combination of a glass substrate and/or an adhesive layer and/or a polymeric layer and/or a film substrate layer.

Glass Substrate

The glass substrate may be an amorphous inorganic non-metallic material, which is typically made from various inorganic minerals (such as quartz sand, borax, boric acid, barite, barium carbonate, limestone, feldspar, soda ash and the like) as the main raw material, with a small amount of auxiliary raw materials added. Its main components are silica and other oxides. The “glass” may be of any type, including a sodium-containing glass or a low sodium glass (such as a high borosilicate glass, a high aluminosilicate glass or the like) . The shape of the glass substrate may be arbitrary. According to practical requirements, the glass substrate may be for example square, rectangle, circle, ellipse, regular hexagon or the like. According to practical requirements, the glass may be a strengthened glass which has undergone strengthening treatment, such as a glass which has undergone chemically strengthening treatment. In addition, according to actual requirements, the glass substrate may be flat glass or curved glass. In addition, the glass substrate has a thickness of about 1 mm or more. In an embodiment, the glass substrate has a thickness of about 1 mm or more and about 4 mm or less. For example, about 1 mm, about 2 mm, about 3 mm, about 4 mm.

In an embodiment, the glass substrate comprises any one of soda-lime-silica float glass, borosilicate glass, aluminosilicate glass, glass-ceramic glass, and polycarbonate glass or any combination thereof. In a preferred embodiment, the glass substrate is soda-lime-silica float glass.

When a glass substrate is used as the transparent substrate of the present disclosure, the advantages of the glass substrate can be fully utilized, such as low haze, high transparency, good scratch resistance, etc. In addition, the surface of the glass structure has abundant hydroxide groups, which enables the glass substrate to have strong adhesion to adjacent layers, especially adjacent layers of polymeric materials. A suitable type of glass substrate may render the transparent substrate or the composite assembly of the present disclosure with a high transmittance for visible light (for example, external visible light) incident from a side of the transparent substrate facing away from the light-absorbing substrate, so that most of visible light passes through the transparent substrate and reaches the semi-reflective layer, thereby helping the semi-reflective layer achieve its effect, realizing the thermal comfort control effect of the composite assembly and the like.

Adhesive Layer

In the present disclosure, the adhesive layer used as a transparent substrate is transparent with a high transmittance, and can transmit most of visible light. In addition, the adhesive layer also has suitable adhesion to adjacent layers. In an embodiment, the adhesive layer comprises any one of an optical adhesive, a thermoplastic polymer, and a pressure-sensitive adhesive or any combination thereof. In a preferred embodiment, the adhesive layer comprises any one of polyvinyl butyral, ethylene vinyl acetate copolymer, thermoplastic polyurethane elastomer, and ionic intermediate film or any combination thereof. In a more preferred embodiment, the adhesive layer comprises an ionic intermediate film.

Polymeric Layer

In an embodiment, the polymeric layer comprises any one of polyester, polyacrylate, polycarbonate, polyurethane, polyamide, polyimide, photocrosslinked and/or photopolymerized resin, and polythiourethane or any combination thereof.

Film Substrate Layer

In an embodiment, the film substrate layer comprises any one of a glass film and a thermoplastic polymer film or any combination thereof. In a preferred embodiment, the thermoplastic polymer film comprises any one of polyethylene terephthalate, polymethyl methacrylate, polyimide and cyclo olefin polymer or any combination thereof. In a more preferred embodiment, the glass film has a thickness of about 25 μm to about 200 μm. In another more preferred embodiment, the thermoplastic polymer film has a thickness of about 0.15 mm to about 0.25 mm.

Settings for Transparent Substrate

The transparent substrate comprises two major surfaces. In the present disclosure, one major surface of the transparent substrate is textured, and this major surface is in contact with the first surface of the semi-reflective layer, and the texture of the contacting surface of the transparent substrate with the semi-reflective layer is complementary to the texture of the first surface of the semi-reflective layer. Accordingly, the other major surface of the transparent substrate may be smooth and non-rough, which faces away from the semi-reflective layer. The transparent substrate may be a single layer or multiple layers, and all the single layer or multiple layers are transparent.

As used herein, the term “major surface” refers to a surface that faces towards or faces away from light. For example, in the composite assembly of the present disclosure, one major surface of the transparent substrate may be a surface that faces towards visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate. For example, the other major surface of the transparent substrate may be a surface that faces away from visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate.

In an exemplary embodiment, as shown in FIG. 1 and FIG. 2, Transparent substrate 101 is in contact with textured First surface 1021 of Semi-reflective layer 102, and the contacting surface of the transparent substrate with the semi-reflective layer is textured, and such texture is complementary to the texture of First surface 1021 of Semi-reflective layer 102; while the major surface of Transparent substrate 101 facing away from Semi-reflective layer 102 may be smooth and non-rough.

In an embodiment, the transparent substrate comprises at least one transparent layer.

In the composite assembly of the present disclosure, a “transparent layer” refers to a layer consisting of a transparent material, and in view of its highly transparent property, its optical absorption for light in visible light wavelength range is limited, and most of visible light can be transmitted.

In a specific embodiment, when the first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is a glass substrate, the texture on the glass substrate may be achieved by a process such as acid etching, sandblasting, laser etching, etc. When the first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is a polymeric layer, the texture on the polymeric layer may be achieved by, for example, nanoimprint (e.g., UV nanoimprint, thermal nanoimprint, mold compression nanoimprint) or transfer print (e.g., UV transfer print) .

In an embodiment, a first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is a glass substrate, and a first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a polymeric layer or an adhesive layer; or a first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is a polymeric layer, and a first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a polymeric layer or an adhesive layer or a glass substrate; or a first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is an adhesive layer, and a first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a polymeric layer or a glass substrate.

In an embodiment, the transparent substrate further comprises a second transparent layer, which is in contact with the first transparent layer of the transparent substrate on a side of the first transparent layer of the transparent substrate facing away from the semi-reflective layer; when the first transparent layer of the transparent substrate is a polymeric layer, the second transparent layer is an adhesive layer, optionally, the transparent substrate further comprises a glass substrate in contact with the adhesive layer on a side of the adhesive layer facing away from the polymeric layer; or the second transparent layer is a film substrate layer, optionally, the transparent substrate further comprises an adhesive layer in contact with the film substrate layer on a side of the film substrate layer facing away from the polymeric layer, further optionally, the transparent substrate further comprises a glass substrate in contact with the adhesive layer on a side of the adhesive layer facing away from the film substrate layer; when the first transparent layer of the transparent substrate is an adhesive layer, the second transparent layer is a glass substrate.

In a specific embodiment, the transparent substrate is a single-layer transparent layer, wherein one surface of the single-layer transparent layer is in contact with the first surface of the semi-reflective layer, the contacting surface of the single-layer transparent layer is textured, and the texture is complementary to the texture of the first surface of the semi-reflective layer. In a more specific embodiment, the single-layer transparent layer is any one of a glass substrate and a polymeric layer.

In another embodiment, the transparent substrate comprises at least one transparent layer, wherein one surface of one of the transparent layer (s) is in contact with the first surface of the semi-reflective layer, the contacting surface of said one of the transparent layer (s) is textured, and the texture is complementary to the texture of the first surface of the semi-reflective layer, and all the layers comprised in the transparent substrate are transparent layers. In a specific embodiment, the transparent substrate comprises two or more transparent layers, and all the layers comprised in the transparent substrate are transparent layers. In a specific embodiment, the at least one transparent layer comprises any one of a glass substrate, an adhesive layer, a polymeric layer, and a film substrate layer or any combination thereof.

In a specific embodiment, the first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is a glass substrate. In another specific embodiment, the first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is a polymeric layer. In yet another specific embodiment, the first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is an adhesive layer.

In a further embodiment, the transparent substrate comprises two or more transparent layers, wherein the transparent layer in contact with the first surface of the semi-reflective layer is a first transparent layer, and the transparent substrate further comprises a second transparent layer, which is in contact with the first transparent layer of the transparent substrate on a side of the first transparent layer of the transparent substrate facing away from the semi-reflective layer, and when the first transparent layer of the transparent substrate is a polymeric layer, the second transparent layer is an adhesive layer. In a still further embodiment, the transparent substrate further comprises a glass substrate in contact with the adhesive layer on a side of the adhesive layer facing away from the polymeric layer.

In another further embodiment, the transparent substrate comprises two or more transparent layers, wherein the transparent layer in contact with the first surface of the semi-reflective layer is a first transparent layer, and the transparent substrate further comprises a second transparent layer, which is in contact with the first transparent layer of the transparent substrate on a side of the first transparent layer of the transparent substrate facing away from the semi-reflective layer, and when the first transparent layer of the transparent substrate is a polymeric layer, the second transparent layer is a film substrate layer. In a still further embodiment, the transparent substrate further comprises an adhesive layer in contact with the film substrate layer on a side of the film substrate layer facing away from the polymeric layer. In a yet further embodiment, the transparent substrate further comprises a glass substrate in contact with the adhesive layer on a side of the adhesive layer facing away from the film substrate layer.

In another further embodiment, the transparent substrate comprises two or more transparent layers, wherein the transparent layer in contact with the first surface of the semi-reflective layer is a first transparent layer, and the transparent substrate further comprises a second transparent layer, which is in contact with the first transparent layer of the transparent substrate on a side of the first transparent layer of the transparent substrate facing away from the semi-reflective layer, and when the first transparent layer of the transparent substrate is an adhesive layer, the second transparent layer is a glass substrate.

In an exemplary embodiment, the transparent substrate comprises or consists of single transparent layer which is in contact with the first surface of the semi-reflective layer, and the single transparent layer is a glass substrate or a polymeric layer.

In an exemplary embodiment, the transparent substrate comprises or consists of two transparent layers, wherein the first transparent layer in contact with the first surface of the semi-reflective layer is an adhesive layer, the second transparent layer is a glass substrate which is in contact with the adhesive layer on a side of the adhesive layer facing away from the semi-reflective layer, that is, the adhesive layer is located between the glass substrate and the semi-reflective layer, and both the adhesive layer and the glass substrate are transparent layers. Alternatively, the first transparent layer in contact with the first surface of the semi-reflective layer is a polymeric layer, and the second transparent layer is a film substrate layer, which is in contact with the polymeric layer on a side of the polymeric layer facing away from the semi-reflective layer, and both the polymeric layer and the film substrate layer are transparent layers.

In an exemplary embodiment, the transparent substrate comprises or consists of three transparent layers, wherein the first transparent layer in contact with the first surface of the semi-reflective layer is a polymeric layer; the second transparent layer is an adhesive layer which is in contact with the polymeric layer on a side of the polymeric layer facing away from the semi-reflective layer; the third transparent layer is a glass substrate which is in contact with the adhesive layer on a side of the adhesive layer facing away from the polymeric layer; and all the adhesive layer, the polymeric layer and the glass substrate are transparent layers.

In an exemplary embodiment, the transparent substrate comprises or consists of four transparent layers, wherein the first transparent layer in contact with the first surface of the semi-reflective layer is a polymeric layer; the second transparent layer is a film substrate layer which is in contact with the polymeric layer on a side of the polymeric layer facing away from the semi-reflective layer; the third transparent layer is an adhesive layer which is in contact with the film substrate layer on a side of the film substrate layer facing away from the polymeric layer; the fourth transparent layer is a glass substrate which is in contact with the adhesive layer on a side of the adhesive layer facing away from the film substrate layer; and all the polymeric layer, the film substrate layer, the adhesive layer and the glass substrate are transparent layers.

Semi-Reflective Layer

In the present disclosure, the semi-reflective layer refers to a layer that is semi-reflective to light. The semi-reflective layer of the present disclosure has a high diffuse reflectance for visible light (e.g., having a diffuse reflectance of greater than 40%for visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate) . In addition, the semi-reflective layer of the present disclosure also has a high diffuse reflectance for near-infrared light (for example, having a diffuse reflectance of greater than or equal to 55%for near-infrared light incident from a side of the transparent substrate facing away from the light-absorbing substrate) . In a specific embodiment, the semi-reflective layer is formed by coating, and thus may also be referred to as a semi-reflective coating layer. The semi-reflectivity of a semi-reflective layer refers to: when incident radiation (such as visible light) reaches a semi-reflective layer, a part of the incident radiation is diffusely reflected by the semi-reflective layer, and a part of the incident radiation is transmitted by the semi-reflective layer.

In an embodiment, the semi-reflective layer is located between the transparent substrate and the light-absorbing substrate. In an embodiment, the semi-reflective layer has a textured first surface and a textured second surface. In a further embodiment, the transparent substrate is in contact with the first surface of the semi-reflective layer, the contacting surface of the transparent substrate is textured, and the texture is complementary to the texture of the first surface of the semi-reflective layer. In a further embodiment, the light-absorbing substrate is in contact with the second surface of the semi-reflective layer, the contacting surface of the light-absorbing substrate is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer.

In an exemplary embodiment, as shown in FIG. 2, Semi-reflective layer 102 is textured and has textured First surface 1021 and textured Second surface 1022.

Diffuse Reflection and Transmission of Semi-Reflective Layer to Visible Light

In the composite assembly of the present disclosure, the semi-reflective layer has a relatively high diffuse reflectance to visible light in incident light incident from a side of the transparent substrate facing away from the light-absorbing substrate. In a specific embodiment, the incident light is sunlight, and the semi-reflective layer also has a relatively high diffuse reflectance for near-infrared light in the incident light.

In one aspect, in the present disclosure, the semi-reflective layer diffusely reflects visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate, and has a high diffuse reflectance. Such a high diffuse reflectance helps to achieve good thermal comfort on the side of the light-absorbing substrate facing away from the transparent substrate, and the diffuse reflection rather than specular reflection can avoid light pollution. Accordingly, the semi-reflective layer has a relatively low transmittance for visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate. In a specific embodiment, the visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate is an external visible light source of the composite assembly. In a more specific embodiment, the external visible light source is external sunlight, and the visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate is a part of the external sunlight. In this case, as described above, the semi-reflective layer may also have a relatively high diffuse reflectance for the near-infrared light in the external sunlight.

On the other hand, in the present disclosure, the semi-reflective layer diffusely reflects visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate, and has a high diffuse reflectance. In combination with an appropriate light absorption property of the light-absorbing substrate, it helps to achieve a good projection display effect on the side of the light-absorbing substrate facing away from the transparent substrate. Likewise, diffuse reflection rather than specular reflection can avoid light pollution. In a specific embodiment, the visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate is an internal visible light source of the composite assembly. In a more specific embodiment, according to an application scenario of the composite assembly, the visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate may be indoor visible light of a transportation means such as an automobile or a train. In a particularly specific embodiment, such visible light is visible light emitted by a projection device indoors in a transportation means such as an automobile or a train.

The media on the two sides of the semi-reflective layer, that is, the transparent substrate and the light-absorbing substrate, have close or identical refractive indices, which helps to make the composite assembly of the present disclosure have low haze, thereby meeting the requirement of low haze in certain application scenarios. The haze may be 10%or less, preferably 5%or less. The low haze of the composite assembly can ensure a clear view through the composite assembly. Specifically, the transparent substrate and the light-absorbing substrate respectively comprise at least one layer and any layer of the transparent substrate has a refractive index close to or the same as that of any layer of the light-absorbing substrate. In an embodiment, the absolute value of the refractive index difference between any layer of the transparent substrate and any layer of the light-absorbing substrate may be 0.05 or less, preferably 0.02 or less, more preferably 0.015 or less, such as 0.05 or less, 0.02 or less, 0.018 or less, 0.016 or less, 0.015 or less, 0.014 or less, 0.012 or less, 0.01 or less, 0.008 or less, 0.006 or less, 0.004 or less, 0.002 or less, and the like.

Textured Surface of Semi-Reflective Layer

The contacting surface of an adjacent layer with the semi-reflective layer is textured. When the adjacent layer is a glass substrate, its textured contacting surface may be achieved by a process such as acid etching, sandblasting, laser etching, etc. When the adjacent layer is a polymeric layer, its textured contacting surface may be achieved by nanoimprint (e.g., UV nanoimprint, thermal nanoimprint, mold compression nanoimprint) or transfer print (e.g., UV transfer print) .

In an embodiment, the textured surface of the adjacent layer may be formed by the method described above, and the material of the semi-reflective layer can be coated on the textured surface to form a semi-reflective layer with a textured surface.

When incident radiation on the composite assembly reaches the contacting surface of the semi-reflective layer with its adjacent layer, the reflection is diffuse reflection because the contacting surface is textured. Thus, the diffuse reflection of the composite assembly of the present disclosure for visible light is related to the textured surface of the semi-reflective layer in contact with its adjacent layer.

In a preferred embodiment, the textured first surface is parallel to the textured second surface. In another preferred embodiment, the textured first surface has a root mean square slope of profile of about 1° to about 20°. In yet another preferred embodiment, the textured second surface has a root mean square slope of profile of about 1° to about 20°. In a more preferred embodiment, the root mean square slope of profile of the textured first surface is equal to the root mean square slope of profile of the textured second surface.

Composition of Semi-Reflective Layer

In an embodiment, the semi-reflective layer is a single layer or a multilayer stack.

In an embodiment, the semi-reflective layer is a single layer, and the single layer is a metal layer or a metal alloy layer. The metal layer or the metal alloy layer has a relatively high diffuse reflectance for visible light and near-infrared light.

In another embodiment, the semi-reflective layer is a multilayer stack comprising at least one metal layer or a metal alloy layer. The metal layer or the metal alloy layer has a relatively high diffuse reflectance for visible light and near-infrared light. Each of the contacting surfaces of each layer with its adjacent layers in the multilayer stack layer is textured, and the texture of each of the contacting surfaces is complementary to the texture of its adjacent contacting surface. In a preferred embodiment, each of the textured contacting surfaces (including the textured first surface and the textured second surface described above) of each layer with its adjacent layers in the multilayer stack is parallel to one another.

In an embodiment, the metal layer comprises any one of aluminum, silver and molybdenum or any combination thereof. In a preferred embodiment, the metal layer comprises aluminum. In another preferred embodiment, the metal layer comprises silver. In yet another preferred embodiment, the metal layer comprises aluminum and silver.

In an embodiment, the metal alloy layer comprises any one of an aluminum alloy, a silver alloy, and a molybdenum alloy or any combination thereof. In a preferred embodiment, the metal alloy layer comprises an aluminum alloy.

When the semi-reflective layer is a multilayer stack, the multilayer stack may comprise the same or different metals or metal alloys. For example, the multilayer stack may comprise two metal layers, where one metal layer comprises silver, and the other metal layer comprises silver or aluminum. When the semi-reflective layer is a multilayer stack, and the multilayer stack comprises two or more metal layers, the metal layers in the multilayer stack may be adjacent or may be separated by other layers. For example, two metal layers may be comprised in the multilayer stack, where the two metal layers may be adjacent or separated by a dielectric layer (which may comprise non-metal oxide, such as TiOx) . For another example, the multilayer stack may comprise two metal alloy layers, where one metal alloy layer comprises aluminum alloy, and the other metal alloy layer comprises silver alloy or molybdenum alloy. When the semi-reflective layer is a multilayer stack, and the multilayer stack comprises two or more metal alloy layers, the metal alloy layers in the multilayer stack may be adjacent or may be separated by other layers. For example, two metal alloy layers may be comprised in the multilayer stack, where the two metal alloy layers may be adjacent or separated by a dielectric layer (which may comprise non-metal oxide, such as TiOx) . Certainly, the multilayer stack may also comprise one or more metal layers and one or more metal alloy layers at the same time. Details are not described herein again.

When the semi-reflective layer is a multilayer stack, the multilayer stack may be symmetrically or asymmetrically stacked. For example, merely for explanation rather than actual stack design, a 40 nm TiOx/20 nm Al/40 nm TiOx stack is a symmetric stack, while a 20 nm Al/60 nm TiOx/5 nm Cu stack is an asymmetric stack. Specifically, when the multilayer stack of the semi-reflective layer is a symmetric stack, it can be considered that the reflection and absorption of the semi-reflective layer for incident light incident from its two sides (from the side of the transparent substrate facing away from the light-absorbing substrate and from the side of the light-absorbing substrate facing away from the transparent substrate) are the same. When the multilayer stack of the semi-reflective layer is an asymmetric stack, on the laminated interface of the semi-reflective layer, the reflection and absorption of the semi-reflective layer for incident light incident from its two sides (from the side of the transparent substrate facing away from the light-absorbing substrate and from the side of the light-absorbing substrate facing away from the transparent substrate) may have a certain difference (but according to the optical theory, the semi-reflective layer has no difference in transmission of incident light incident from its two sides) , and such a difference helps to obtain different optical effects (for example, different color appearances and different reflectivity) on two sides of the semi-reflective layer. For example, when used in a vehicle window glass, different optical effects may be respectively provided inside and outside the vehicle window, for example, a colorful appearance is observed from the outside of the vehicle, and a neutral color is still displayed to the inside of the vehicle. Additionally, transmission can remain neutral while reflection can be designed to be chromatic.

Blocking Layer

In an embodiment, the semi-reflective layer further comprises a blocking layer located on one side of the metal layer or the metal alloy layer or on both sides of the metal layer or the metal alloy layer, each of the contacting surfaces of the blocking layer with its adjacent layers is textured, and the texture is complementary to the texture of its adjacent contacting surface. In a preferred embodiment, the textured contacting surfaces of the blocking layer with adjacent layers are parallel to each other. The blocking layer may be used to isolate the metal layer or the metal alloy layer, thereby preventing the metal or metal alloy in the metal layer or the metal alloy layer from being eroded by the external environment, and prolonging the service life of the semi-reflective layer.

In an embodiment, the blocking layer comprises any one of nickel, chromium, titanium, and nickel-chromium alloy or any combination thereof.

Dielectric Layer

In an embodiment, the semi-reflective layer further comprises a dielectric layer, each of the contacting surfaces of the dielectric layer with its adjacent layers is textured, and the texture is complementary to the texture of its adjacent contacting surface. In a preferred embodiment, the textured contacting surfaces of the dielectric layer with adjacent layers are parallel to each other.

On the one hand, in the semi-reflective layer, the dielectric layer can protect the metal or metal alloy in the metal layer or the metal alloy layer from damage from oxidation, moisture or scratching, thus prolonging the service life of the semi-reflective layer.

On the other hand, introducing such a dielectric layer into the semi-reflective layer may make the diffuse reflectance of the semi-reflective layer for visible light different from that for near-infrared light (for example, making the diffuse reflectance of the semi-reflective layer for near-infrared light be greater than that for visible light) , thereby helping the composite assembly to obtain a better thermal comfort control effect at a specific visible light reflectivity level. In addition, the dielectric layer may also adjust, based on the optical interference, a color in which the semi-reflective layer reflects visible light, so that the composite assembly has a unique appearance and aesthetic value.

In an embodiment, the dielectric layer comprises an oxide, a nitride, a sulfide or a carbide of a metal or an inorganic non-metal. In a preferred embodiment, the dielectric layer may comprise TiOx. In another preferred embodiment, the dielectric layer may comprise SiOx. Wherein TiOx represents an oxide of titanium, SiOx represents an oxide of silicon, 1.5 < x ≤ 2.

Absorption Adjustment Layer

In an embodiment, the semi-reflective layer further comprises an absorption adjustment layer, each of the contacting surfaces of the absorption adjustment layer with its adjacent layers is textured, and the texture is complementary to the texture of its adjacent contacting surface, the blocking layer is located on one side of the absorption adjustment layer or on both sides of the absorption adjustment layer. In the semi-reflective layer, the absorption adjustment layer comprises a metal which has a unique light absorption band in the visible light range, so that the color and light absorption of the semi-reflective layer can be adjusted. The blocking layer may be used to isolate the absorption adjustment layer, thereby preventing the metal in the absorption adjustment layer from being eroded by the external environment and prolonging the service life of the semi-reflective layer. In a preferred embodiment, the textured contacting surfaces of the absorption adjustment layers with adjacent layers are parallel to each other.

In an embodiment, the absorption adjustment layer comprises any one of copper, and gold or any combination thereof.

Light-Absorbing Substrate

In the present disclosure, the light-absorbing substrate refers to a material layer having a high absorbance for visible light. The combination of the light-absorbing substrate and the semi-reflective layer helps the composite assembly of the present disclosure to achieve excellent projection display effect.

Specifically, for visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate, after the semi-reflective layer achieves a highly diffuse reflection effect, part of the visible light transmitted through the semi-reflective layer is further absorbed by the light-absorbing substrate. Thus, the composite assembly of the present disclosure achieves a low-transmittance effect, realizing functions such as privacy protection and reducing the interference of external ambient light on the projection display. In addition, for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate, the light-absorbing substrate can appropriately absorb such visible light (including initially incident visible light and visible light diffusely reflected by the semi-reflective layer) , thereby controlling the intensity of the diffusely reflected visible light. This helps to achieve a suitable projection display brightness and avoid potential light pollution on the side of the light-absorbing substrate facing away from the transparent substrate. For example, if the composite assembly is used in a vehicle skylight, the light-absorbing substrate in the composite assembly helps to control the light intensity in the vehicle interior, to achieve a suitable projection display brightness, and to avoid potential light pollution (e.g., excessive reflection of the vehicle interior ambient light or the light from the large-size display panel toward the passengers) . In addition, optionally, the light-absorbing substrate may also help to adjust visible light color on the side of the light-absorbing substrate facing away from the transparent substrate. In an embodiment, the light-absorbing substrate comprises a colored layer, such as a colored polymeric layer, a colored glass substrate, a dark state switchable film (the switchable film is in a dark state) , etc.

Composition of Light-Absorbing Substrate

In an embodiment, the light-absorbing substrate comprises any one of a glass substrate, an adhesive layer, a polymeric layer, a switchable film, and a film substrate layer or any combination thereof. For example, the light-absorbing substrate may be a glass substrate, an adhesive layer, a switchable film, a polymeric layer, a film substrate layer, or the like. In a specific embodiment, the light-absorbing substrate may be a combination of a glass substrate and/or an adhesive layer and/or a switchable film and/or a polymeric layer and/or a film substrate layer.

Glass Substrate

The glass substrate may be an amorphous inorganic non-metallic material, which is typically made from various inorganic minerals (such as quartz sand, borax, boric acid, barite, barium carbonate, limestone, feldspar, soda ash and the like) as the main raw material, with a small amount of auxiliary raw materials added. Its main components are silica and other oxides. The “glass” may be of any type, including a sodium-containing glass or a low sodium glass (such as a high borosilicate glass, a high aluminosilicate glass or the like) . The glass may be, for example, colorless glass, or it may be, for example, colored glass that is tinted by the incorporation of certain metal oxides or salts. The shape of the glass substrate may be arbitrary. According to practical requirements, the glass substrate may be for example square, rectangle, circle, ellipse, regular hexagon or the like. According to practical requirements, the glass may be a strengthened glass which has undergone strengthening treatment, such as a glass which has undergone chemically strengthening treatment. In addition, according to actual requirements, the glass substrate may be flat glass or curved glass. In addition, the glass substrate has a thickness of about 1 mm or more. In an embodiment, the glass substrate has a thickness of about 1 mm or more and about 4 mm or less. For example, about 1 mm, about 2 mm, about 3 mm, about 4 mm.

The glass substrate may be used as a transparent layer and/or a light-absorbing layer in a light-absorbing substrate (described in more detail below) .

In addition, in some embodiments, when the glass substrate serves as the outermost layer of the light-absorbing substrate facing away from the semi-reflective layer, a LowE (Low emissivity) coating may be formed on a surface of the glass substrate facing away from the semi-reflective layer, thereby forming a low emissivity glass substrate. Since the LowE coating has high transmission for visible light and high reflection for infrared light, it helps to achieve a further thermal comfort control effect. In addition, an anti-reflective coating may also be formed on a surface of the glass substrate facing away from the semi-reflective layer, so as to form an anti-reflective glass substrate, thereby helping to achieve a further anti-glare effect.

Adhesive Layer

The adhesive layer has suitable adhesion to adjacent layers. In an embodiment, the adhesive layer comprises any one of an optical adhesive, a thermoplastic polymer, and a pressure-sensitive adhesive or any combination thereof. In a preferred embodiment, the adhesive layer comprises any one of polyvinyl butyral, ethylene vinyl acetate copolymer, thermoplastic polyurethane elastomer, and ionic intermediate film or any combination thereof. In a more preferred embodiment, the adhesive layer comprises an ionic intermediate film.

The adhesive layer may be used as a transparent layer and/or a light-absorbing layer in a light-absorbing substrate (described in more detail below) .

Polymeric Layer

The polymeric layer may be used as a transparent layer and/or a light-absorbing layer in a light-absorbing substrate (detailed below) .

Switchable film

The switchable film may be a smart light-controlling film, which comprises a component with a dimming function, which may be, for example, a liquid crystal molecule, a photosensitizer, or the like. In the present disclosure, when the switchable film is used as the light-absorbing layer described in detail below, a dark state switchable film (the switchable film is in a dark state) is used to achieve the effect of light absorption.

In an embodiment, the switchable film comprises any one of a dye-doped polymer dispersed liquid crystal switchable film, a suspended particle switchable film, an electrochromic switchable film, and a guest-host liquid crystal switchable film or any combination thereof. In a preferred embodiment, the switchable film is a guest-host liquid crystal switchable film.

Film Substrate Layer

The film substrate layer may be used as a transparent layer and/or a light-absorbing layer in a light-absorbing substrate (described in more detail below) .

Settings for Light-Absorbing Substrate

The light-absorbing substrate comprises two major surfaces. In the present disclosure, one major surface of the light-absorbing substrate is textured and this major surface is in contact with the second surface of the semi-reflective layer, and the texture of the contacting surface of the light-absorbing substrate with the semi-reflective layer is complementary to the texture of the second surface of the semi-reflective layer. Accordingly, the other major surface of the light-absorbing substrate is smooth and non-rough, which faces away from the semi-reflective layer. The light-absorbing substrate may be a single layer or multiple layers. When the light-absorbing substrate is a single layer, the single-layer light-absorbing substrate is a light-absorbing layer with a light-absorbing function. When the light-absorbing substrate is multiple layers, at least one layer of the light-absorbing substrate is a light-absorbing layer with a light-absorbing function.

In an exemplary embodiment, as shown in FIG. 1 and FIG. 2, Light-absorbing substrate 103 is in contact with textured Second surface 1022 of Semi-reflective layer 102, and the contacting surface of the light-absorbing substrate with the semi-reflective layer is textured, and the texture of the contacting surface is complementary to the texture of Second surface 1022 of Semi-reflective layer 102; and the major surface of Light-absorbing substrate 103 facing away from Semi-reflective layer 102 is smooth and non-rough.

In an embodiment, the light-absorbing substrate comprises at least one light-absorbing layer, wherein one surface of one of the light-absorbing layer (s) is in contact with the second surface of the semi-reflective layer, the contacting surface of said one of the light-absorbing layer (s) is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer. In another embodiment, the light-absorbing substrate comprises at least one light-absorbing layer and at least one transparent layer, one surface of one of the light-absorbing layer (s) or one of the transparent layer (s) is in contact with the second surface of the semi-reflective layer, the contacting surface of said one of the light-absorbing layer (s) or said one of the transparent layer (s) is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer. In the composite assembly of the present disclosure, the “light-absorbing layer” refers to a layer having a certain light absorption property in the light-absorbing substrate, which is capable of absorbing a certain degree of visible light relative to the transparent layer.

In a specific embodiment, when the first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a glass substrate, the texture on the glass substrate may be achieved by a process such as acid etching, sand blasting, laser etching, etc. When the first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a polymeric layer, the texture on the polymeric layer may be achieved by, for example, nanoimprint (e.g., UV nanoimprint, thermal nanoimprint, mold compression nanoimprint) or transfer print (e.g., UV transfer print) .

In an embodiment, the light-absorbing substrate further comprises a second light-absorbing layer or transparent layer, which is in contact with the first transparent layer or light-absorbing layer of the light-absorbing substrate on a side of the first transparent layer or light-absorbing layer of the light-absorbing substrate facing away from the semi-reflective layer, when the first transparent layer or light-absorbing layer of the light-absorbing substrate is a polymeric layer, the second light-absorbing layer or transparent layer is an adhesive layer, optionally, the light-absorbing substrate further comprises a glass substrate or a switchable film in contact with the adhesive layer on a side of the adhesive layer facing away from the polymeric layer; or the second light-absorbing layer or transparent layer is a film substrate layer, optionally, the light-absorbing substrate further comprises an adhesive layer in contact with the film substrate layer on a side of the film substrate layer facing away from the polymeric layer, further optionally, the light-absorbing substrate further comprises a glass substrate or a switchable film in contact with the adhesive layer on a side of the adhesive layer facing away from the film substrate layer; when the first transparent layer or light-absorbing layer of the light-absorbing substrate is an adhesive layer, the second light-absorbing layer or transparent layer is a glass substrate or a switchable film.

In a specific embodiment, the light-absorbing substrate is a single-layer light-absorbing layer, a surface of the single-layer light-absorbing layer is in contact with a second surface of the semi-reflective layer, the contacting surface of the single-layer light-absorbing layer is textured and the texture is complementary to the texture of the second surface of the semi-reflective layer. In a more specific embodiment, the single-layer light-absorbing layer is any one of a glass substrate and a polymeric layer.

In another specific embodiment, the light-absorbing substrate comprises at least one light-absorbing layer, wherein one surface of one of the light-absorbing layer (s) is in contact with the second surface of the semi-reflective layer, the contacting surface of said one of the light-absorbing layer (s) is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer. In a specific embodiment, the at least one light-absorbing layer comprises any one of a glass substrate, a polymeric layer, an adhesive layer, a switchable film, and a film substrate layer or any combination thereof.

In yet another specific embodiment, the light-absorbing substrate comprises at least one light-absorbing layer and at least one transparent layer, one surface of one of the light-absorbing layer (s) or one of the transparent layer (s) is in contact with the second surface of the semi-reflective layer, the contacting surface of said one of the light-absorbing layer (s) or said one of the transparent layer (s) is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer. In a specific embodiment, the at least one light-absorbing layer or the at least one transparent layer comprises any one of a glass substrate, a polymeric layer, an adhesive layer, a switchable film, and a film substrate layer or any combination thereof.

In a specific embodiment, the first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a glass substrate. In another specific embodiment, the first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a polymeric layer. In yet another specific embodiment, the first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is an adhesive layer.

In a further embodiment, the light-absorbing substrate comprises at least two light-absorbing layers or transparent layers, wherein at least one of the at least two layers is a light-absorbing layer, and the transparent layer or light-absorbing layer in contact with the second surface of the semi-reflective layer is a first transparent layer or light-absorbing layer, and the light-absorbing substrate further comprises a second light-absorbing layer or transparent layer, which is in contact with the first transparent layer or light-absorbing layer of the light-absorbing substrate on a side of the first transparent layer or light-absorbing layer of the light-absorbing substrate facing away from the semi-reflective layer, and when the first transparent layer or light-absorbing layer of the light-absorbing substrate is a polymeric layer, the second light-absorbing layer or transparent layer is an adhesive layer. In yet a further embodiment, the light-absorbing substrate further comprises a glass substrate or a switchable film in contact with the adhesive layer on a side of the adhesive layer facing away from the polymeric layer.

In another further embodiment, the light-absorbing substrate comprises at least two light-absorbing layers or transparent layers, at least one of the at least two layers is a light-absorbing layer, and the transparent layer or light-absorbing layer in contact with the second surface of the semi-reflective layer is a first transparent layer or light-absorbing layer, the light-absorbing substrate further comprises a second light-absorbing layer or transparent layer, which is in contact with the first transparent layer or light-absorbing layer of the light-absorbing substrate on a side of the first transparent layer or light-absorbing layer of the light-absorbing substrate facing away from the semi-reflective layer, and when the first transparent layer or light-absorbing layer of the light-absorbing substrate is a polymeric layer, the second light-absorbing layer or transparent layer is a film substrate layer. In a still further embodiment, the light-absorbing substrate further comprises an adhesive layer in contact with the film substrate layer on a side of the film substrate layer facing away from the polymeric layer. In a yet further embodiment, the light-absorbing substrate further comprises a glass substrate or a switchable film in contact with the adhesive layer on a side of the adhesive layer facing away from the film substrate layer.

In another further embodiment, the light-absorbing substrate comprises at least two light-absorbing layers or transparent layers, at least one of the at least two layers is a light-absorbing layer, and the transparent layer or light-absorbing layer in contact with the second surface of the semi-reflective layer is a first transparent layer or light-absorbing layer, the light-absorbing substrate further comprises a second light-absorbing layer or transparent layer, which is in contact with the first transparent layer or light-absorbing layer of the light-absorbing substrate on a side of the first transparent layer or light-absorbing layer of the light-absorbing substrate facing away from the semi-reflective layer, and when the first transparent layer or light-absorbing layer of the light-absorbing substrate is an adhesive layer, the second light-absorbing layer or transparent layer is a glass substrate or a switchable film.

In an exemplary embodiment, the light-absorbing substrate comprises or consists of single light-absorbing layer, which is in contact with the second surface of the semi-reflective layer, and the single light-absorbing layer is a glass substrate or a polymeric layer.

In an exemplary embodiment, the light-absorbing substrate comprises or consists of two light-absorbing layers or transparent layers and at least one of the two layers is a light-absorbing layer, wherein the first transparent layer or light-absorbing layer in contact with the second surface of the semi-reflective layer is an adhesive layer, and the second transparent layer or light-absorbing layer is a glass substrate or a switchable film which is in contact with the adhesive layer on a side of the adhesive layer facing away from the semi-reflective layer, that is, the adhesive layer is located between the glass substrate or the switchable film and the semi-reflective layer, and at least one of the adhesive layer and the glass substrate/switchable film is a light-absorbing layer. Alternatively, the first transparent layer or light-absorbing layer in contact with the second surface of the semi-reflective layer is a polymeric layer, and the second transparent layer or light-absorbing layer is a film substrate layer, which is in contact with the polymeric layer on a side of the polymeric layer facing away from the semi-reflective layer, and at least one of the polymeric layer and the film substrate layer is a light-absorbing layer.

In an exemplary embodiment, the light-absorbing substrate comprises or consists of three light-absorbing layers or transparent layers and at least one of the three layers is a light-absorbing layer, wherein the first transparent layer or light-absorbing layer in contact with the second surface of the semi-reflective layer is a polymeric layer; the second transparent layer or light-absorbing layer is an adhesive layer which is in contact with the polymeric layer on a side of the polymeric layer facing away from the semi-reflective layer; and the third transparent layer or light-absorbing layer is a glass substrate or a switchable film which is in contact with the adhesive layer on a side of the adhesive layer facing away from the polymeric layer, and at least one of the polymeric layer, the adhesive layer and the glass substrate/switchable film is a light-absorbing layer.

In an exemplary embodiment, the light-absorbing substrate comprises or consists of four light-absorbing layers or transparent layers and at least one of the four layers is a light-absorbing layer, wherein the first transparent layer or light-absorbing layer in contact with the second surface of the semi-reflective layer is a polymeric layer; the second transparent layer or light-absorbing layer is a film substrate layer which is in contact with the polymeric layer on a side of the polymeric layer facing away from the semi-reflective layer; the third transparent layer or light-absorbing layer is an adhesive layer which is in contact with the film substrate layer on a side of the film substrate layer facing away from the polymeric layer; and the fourth transparent layer or light-absorbing layer is a glass substrate or a switchable film which is in contact with the adhesive layer on a side of the adhesive layer facing away from the film substrate layer, and at least one of the polymeric layer, the film substrate layer, the adhesive layer and the glass substrate/switchable film is a light-absorbing layer. Alternatively, the first transparent layer or light-absorbing layer in contact with the second surface of the semi-reflective layer is a first adhesive layer; the second transparent layer or light-absorbing layer is a switchable film which is in contact with the first adhesive layer on a side of the first adhesive layer facing away from the semi-reflective layer; the third transparent layer or light-absorbing layer is a second adhesive layer which is in contact with the switchable film on a side of the switchable film facing away from the first adhesive layer; and the fourth transparent layer or light-absorbing layer is a glass substrate which is in contact with the second adhesive layer on a side of the second adhesive layer facing away from the switchable film, and at least one of the first adhesive layer, the switchable film, the second adhesive layer and the glass substrate is a light-absorbing layer.

In an exemplary embodiment, the light-absorbing substrate comprises or consists of five light-absorbing layers or transparent layers and at least one of the five layers is a light-absorbing layer, wherein the first transparent layer or light-absorbing layer in contact with the second surface of the semi-reflective layer is a polymeric layer; the second transparent layer or light-absorbing layer is a first adhesive layer which is in contact with the polymeric layer on a side of the polymeric layer facing away from the semi-reflective layer; the third transparent layer or light-absorbing layer is a switchable film which is in contact with the first adhesive layer on a side of the first adhesive layer facing away from the polymeric layer; the fourth transparent layer or light-absorbing layer is a second adhesive layer which is in contact with the switchable film on a side of the switchable film facing away from the first adhesive layer; and the fifth transparent layer or light-absorbing layer is a glass substrate which is in contact with the second adhesive layer on a side of the second adhesive layer facing away from the switchable film, and at least one of the polymeric layer, the first adhesive layer, the switchable film, the second adhesive layer and the glass substrate is a light-absorbing layer.

In an exemplary embodiment, the light-absorbing substrate comprises or consists of six light-absorbing layers or transparent layers and at least one of the six layers is a light-absorbing layer, wherein the first transparent layer or light-absorbing layer in contact with the second surface of the semi-reflective layer is a polymeric layer; the second transparent layer or light-absorbing layer is a film substrate layer which is in contact with the polymeric layer on a side of the polymeric layer facing away from the semi-reflective layer; the third transparent layer or light-absorbing layer is a first adhesive layer which is in contact with the film substrate layer on a side of the film substrate layer facing away from the polymeric layer; the fourth transparent layer or light-absorbing layer is a switchable film which is in contact with the first adhesive layer on a side of the first adhesive layer facing away from the film substrate layer; the fifth transparent layer or light-absorbing layer is a second adhesive layer which is in contact with the switchable film on a side of the switchable film facing away from the first adhesive layer; and the sixth transparent layer or light-absorbing layer is a glass substrate which is in contact with the second adhesive layer on a side of the second adhesive layer facing away from the switchable film, and at least one of the polymeric layer, the film substrate layer, the first adhesive layer, the switchable film, the second adhesive layer and the glass substrate is a light-absorbing layer.

Haze of Composite Assembly

As shown in FIG. 1 and FIG. 2, Transparent substrate 101 is in contact with First surface 1021 of Semi-reflective layer 102, and Light-absorbing substrate 103 is in contact with Second surface 1022 of Semi-reflective layer 102, and Light-absorbing substrate 103 has a refractive index close to or the same as that of Transparent substrate 101, which helps to make the composite assembly of the present disclosure have low haze, thereby meeting the requirement of low haze in some application scenarios. For example, the haze may be 10%or less, preferably 5%or less. The low haze of the composite assembly can ensure a clear view through the composite assembly. Specifically, as described above, the transparent substrate and the light-absorbing substrate respectively comprise at least one layer, and any layer of the transparent substrate has a refractive index close to or the same as that of any layer of the light-absorbing substrate. In an embodiment, the absolute value of the refractive index difference between any layer of the light-absorbing substrate and any layer of the transparent substrate may be 0.05 or less, preferably 0.02 or less, more preferably 0.015 or less, such as 0.05 or less, 0.02 or less, 0.018 or less, 0.016 or less, 0.015 or less, 0.014 or less, 0.012 or less, 0.01 or less, 0.008 or less, 0.006 or less, 0.004 or less, 0.002 or less, and the like.

Exemplary Settings for Composite Assembly

When the transparent substrate and the light-absorbing substrate are described above, examples of some possible settings of the transparent substrate and the light-absorbing substrate have been enumerated. Those skilled in the art may understand that all possible settings for the composite assembly cannot be exhausted, and thus only several specific settings of the composite assembly will be listed below as an example.

In an exemplary embodiment, as shown in FIG. 3, the composite assembly of the present disclosure comprises Polymeric layer 2031, Semi-reflective layer 2032, Polymeric layer 2033, and Film substrate layer 2034. Since a transparent substrate is located on one side of Semi-reflective layer 2032 and a light-absorbing substrate is located on the other side thereof, either of Polymeric layer 2031 AND Polymeric layer 2033, Film substrate layer 2034 is the transparent substrate, and the other is the light-absorbing substrate. For example, when Polymeric layer 2033 and Film substrate layer 2034 is the light-absorbing substrate, at least one of Polymeric layer 2033 and Film substrate layer 2034 is a light-absorbing layer. The transparent substrate faces the external visible light source, i.e., the transparent substrate is closer to the external visible light source than the light-absorbing substrate, and the light-absorbing substrate faces towards the projection light when the composite assembly is used as a projection screen. Further, the composite assembly may consist of Polymeric layer 2031, Semi-reflective layer 2032, Polymeric layer 2033, and Film substrate layer 2034.

In a further exemplary embodiment, as shown in FIG. 11, the stack structure shown in FIG. 3 may be adhered to Glass substrate 1101 by Adhesive layer 1102. That is, in this case, the composite assembly of the present disclosure comprises Glass substrate 1101, Adhesive layer 1102, and Stack structure 1103 as shown in FIG. 3. Film substrate layer 2034 shown in FIG. 3 may be away from Adhesive layer 1102 relative to Polymeric layer 2031, and optionally, when Film substrate layer 2034 is a glass film, the glass film may be a tempered glass film, such as a chemically strengthened glass film. Similarly, a transparent substrate is located on one side of Semi-reflective layer 2032, and a light-absorbing substrate is located on the other side thereof. Details are not described herein again. Further, the composite assembly may consist of Glass substrate 1101, Adhesive layer 1102, and Stack structure 1103 as shown in FIG. 3.

In a further exemplary embodiment, as shown in FIG. 12, the stack structure shown in FIG. 3 may be sandwiched between First glass substrate 1201 and Second glass substrate 1205 by First adhesive layer 1202 and Second adhesive layer 1204. That is, in this case, the composite assembly of the present disclosure comprises First glass substrate 1201, First adhesive layer 1202, Stack structure 1203 as shown in FIG. 3, Second adhesive layer 1204, and Second glass substrate 1205. Film substrate layer 2034 shown in FIG. 3 may be closer to First glass substrate 1201 or may also be closer to Second glass substrate 1205, relative to Polymeric layer 2031. Further, Film substrate layer 2034 and/or Polymeric layer 2031 shown in FIG. 3 may also be omitted from the composite assembly shown in FIG. 12. In addition, a switchable film may also be inserted for example between the two glass substrates in FIG. 12 and details are not described herein again. Similarly, a transparent substrate is located on one side of Semi-reflective layer 2032, and a light-absorbing substrate is located on the other side thereof. Details are not described herein again. Further, the composite assembly may consist of First glass substrate 1201, First adhesive layer 1202, Stack structure 1203 as shown in FIG. 3, Second adhesive layer 1204, and Second glass substrate 1205.

In an exemplary embodiment, as shown in FIG. 4, the composite assembly of the present disclosure comprises Glass substrate 2035, Semi-reflective layer 2032, Adhesive layer 2036, and Glass substrate 2037. Since a transparent substrate is located on one side of Semi-reflective layer 2032, and a light-absorbing substrate is located on the other side thereof, either of Glass substrate 2035 AND Adhesive layer 2036, Glass substrate 2037 is the transparent substrate, and the other is the light-absorbing substrate. For example, when Adhesive layer 2036 and Glass substrate 2037 is the light-absorbing substrate, at least one of Adhesive layer 2036 and Glass substrate 2037 is a light-absorbing layer. Alternatively, Glass substrate 2037 may be replaced with a switchable film, in which case Adhesive layer 2036 and Switchable film 2037 is the light-absorbing substrate. The transparent substrate faces the external visible light source, i.e., the transparent substrate is closer to the external visible light source than the light-absorbing substrate, and the light-absorbing substrate faces towards the projection light when the composite assembly is used as a projection screen. Further, the composite assembly may consist of Glass substrate 2035, Semi-reflective layer 2032, Adhesive layer 2036, and Glass substrate 2037.

In an exemplary embodiment, as shown in FIG. 13, the composite assembly of the present disclosure comprises Glass substrate 1301, Adhesive layer 1303, Polymeric layer 1304, Semi-reflective layer 1302, and Glass substrate 1305. Polymeric layer 1304 herein may play a role of planarization, and is therefore sometimes also referred to as a planarization layer. Since a transparent substrate is located on one side of Semi-reflective layer 1302, and a light-absorbing substrate is located on the other side thereof, either of Glass substrate 1301, Adhesive layer 1303, Polymeric layer 1304 AND Glass substrate 1305 is the transparent substrate, and the other is the light-absorbing substrate. For example, when Glass substrate 1301, Adhesive layer 1303, and Polymeric layer 1304 is the light-absorbing substrate, at least one of Glass substrate 1301, Adhesive layer 1303, and Polymeric layer 1304 is a light-absorbing layer. Alternatively, Glass substrate 1301 may be replaced with a switchable film, in which case Switchable film 1301, Adhesive layer 1303, and Polymeric layer 1304 is the light-absorbing substrate. The transparent substrate faces the external visible light source, i.e., the transparent substrate is closer to the external visible light source than the light-absorbing substrate, and the light-absorbing substrate faces towards the projection light when the composite assembly is used as a projection screen. Further, the composite assembly may consist of Glass substrate 1301, Adhesive layer 1303, Polymeric layer 1304, Semi-reflective layer 1302, and Glass substrate 1305.

In an exemplary embodiment, as shown in FIG. 14, the composite assembly of the present disclosure comprises Glass substrate 1401, Adhesive layer 1403, Semi-reflective layer 1402, Polymeric layer 1404, Adhesive layer 1405, and Glass substrate 1406. Preferably, Adhesive layer 1405 may be an optical adhesive. Since a transparent substrate is located on one side of Semi-reflective layer 1402, and a light-absorbing substrate is located on the other side thereof, either of Glass substrate 1401, Adhesive layer 1403, AND Polymeric layer 1404, Adhesive layer 1405, Glass substrate 1406 is the transparent substrate, and the other is the light-absorbing substrate. For example, when Polymeric layer 1404, Adhesive layer 1405, and Glass substrate 1406 is the light-absorbing substrate, at least one of Polymeric layer 1404, Adhesive layer 1405, and Glass substrate 1406 is a light-absorbing layer. Alternatively, Glass substrate 1406 may be replaced with a switchable film, in which case Polymeric layer 1404, Adhesive layer 1405, and Switchable film 1406 is the light-absorbing substrate. The transparent substrate faces the external visible light source, i.e., the transparent substrate is closer to the external visible light source than the light-absorbing substrate, and the light-absorbing substrate faces towards the projection light when the composite assembly is used as a projection screen. Further, the composite assembly may consist of Glass substrate 1401, Adhesive layer 1403, Semi-reflective layer 1402, Polymeric layer 1404, Adhesive layer 1405, and Glass substrate 1406.

Property of Composite Assembly

The composite assembly of the present disclosure comprises a textured semi-reflective layer, which has a high level of diffuse reflection for both visible light and near-infrared light, and comprises a transparent substrate with high transparency and a light-absorbing substrate with light absorption, so that the composite assembly of the present disclosure achieves excellent thermal comfort control effect and projection display effect.

Transmission of Composite Assembly for Visible Light Incident from a Side of Transparent Substrate facing away from Light-Absorbing Substrate

FIG. 5a and FIG. 5b illustrate an exemplary embodiment of a composite assembly of the present disclosure, wherein the composite assembly comprises Transparent substrate 301, Semi-reflective layer 302, and Light-absorbing substrate 303. Visible light 300 may enter the transparent substrate from a side of the transparent substrate facing away from the light-absorbing substrate, and sequentially pass through Transparent substrate 301, Semi-reflective layer 302 and Light-absorbing substrate 303. The composite assembly achieves excellent thermal comfort control effect by reflection, transmission and absorption of the incident light.

Specifically, as shown in FIG. 5a, the composite assembly has a transmittance TL for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate. More specifically, as shown in FIG. 5b, the transmittance TL of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is related to the transmittance T1 of the transparent substrate for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate, the transmittance T2 of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate, and the transmittance T3 of the light-absorbing substrate for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate. Therefore, the transmittance TL of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate may be expressed as the relationship in Formula I.
TL = T1 *T2 *T3 Formula I

More specifically, when visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate passes through the transparent substrate, visible light will be reflected, absorbed and transmitted by the transparent substrate. Specifically, as shown in FIG. 5b, visible light is first reflected at the interface between the outside (e.g., air) and the transparent substrate, and then absorbed by the transparent substrate. Therefore, the transmittance T1 of the transparent substrate to visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate may be expressed as T1 = (100%-R1) * (100%-A1) , where R1 represents the reflectance of the transparent substrate for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate. Specifically, as shown in FIG. 5b, R1 represents the reflectance of the interface between the outside (e.g., air) and the transparent substrate for visible light, and A1 represents the absorbance of the transparent substrate for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate.

Similarly, when visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate passes through the semi-reflective layer, visible light is diffusely reflected, absorbed and transmitted by the semi-reflective layer, and since the thickness of the semi-reflective layer is rather low, as shown in FIG. 5b, the diffuse reflection and the absorption occur in the same phase, thus, the transmittance T2 of the semi-reflective layer to visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate may be expressed as T2 = (100%-R2 -A2) , where R2 represents the diffuse reflectance of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate. As shown in FIG. 5b, the reflection of visible light by the semi-reflective layer is diffuse reflection, and A2 represents the absorbance of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate.

Similarly, when visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate passes through the light-absorbing substrate, visible light is reflected, absorbed and transmitted by the light-absorbing substrate. Specifically, as shown in FIG. 5b, visible light is first absorbed by the light-absorbing substrate and then reflected at the interface between the light-absorbing substrate and the outside (for example, air) . Therefore, the transmittance T3 of the light-absorbing substrate for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate may be expressed as T3 = (100%-R3) * (100%-A3) , where R3 represents the reflectance of the light-absorbing substrate for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate (that is, the reflectance of the light-absorbing substrate for the incident visible light) . Specifically, as shown in FIG. 5b, R3 represents the reflectance of the interface between the light-absorbing substrate and the outside (for example, air) for visible light, and A3 represents the absorbance of the light-absorbing substrate for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate (that is, the absorbance of the light-absorbing substrate for the incident visible light) .

Based on this, the transmittance TL of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate may be expressed as a relationship in Formula II.
TL = (100%-R1) * (100%-A1) * (100%-R2 -A2) * (100%-R3) * (100%-A3)
Formula II

In an embodiment, the transmittance TL is from about 0.5%to about 10%, preferably from about 0.5%to about 2.5% (considering all-weather projection display, which will be described below in detail) . Such transmittance range is set to achieve functions such as privacy function, visibility to the outside function, and reducing interference of external ambient light on projection display.

The present disclosure inventively adopts a composite assembly design comprising a transparent substrate, a semi-reflective layer, and a light-absorbing substrate, which is capable of reflecting, absorbing, and transmitting visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate multiple times.

The semi-reflective layer of the composite assembly diffusely reflects visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate with high diffuse reflectance. On the one hand, this causes most of visible light to be diffusely reflected while a small amount transmits through the semi-reflective layer, effectively controlling the ambient temperature on the light-absorbing substrate side and helping achieve thermal comfort control effect. On the other hand, since it is diffuse reflection rather than specular reflection, the light pollution on the transparent substrate side is very limited. In addition, the transparent substrate is highly transparent to visible light and rarely absorbs visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate, which can ensure that visible light effectively reaches the semi-reflective layer and is highly diffusely reflected by the semi-reflective layer. The transparent substrate also has very low light absorption for visible light diffusely reflected by the semi-reflective layer, thereby avoiding the secondary emission problem caused by absorption of visible light in the prior art, making full use of the function of the semi-reflective layer, thereby achieving the thermal comfort control effect of the composite assembly. In addition, on the one hand, the light-absorbing substrate may be combined with the semi-reflective layer to achieve the target transmittance TL of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate, without affecting the thermal comfort performance. On the other hand, the light-absorbing substrate may absorb appropriately visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate (including visible light diffusely reflected by the semi-reflective layer in this visible light) , thereby achieving appropriate projection display brightness on the light-absorbing substrate side and avoiding potential light pollution.

Diffuse Reflection of Composite Assembly for Incident Light Incident from a Side of Transparent Substrate facing away from Light-Absorbing Substrate

When light enters the composite assembly of the present disclosure from the side of the transparent substrate facing away from the light-absorbing substrate, the composite assembly has a high diffuse reflectance for visible light, and also has a high diffuse reflectance for near-infrared light.

Specifically, as shown in FIG. 5c, the diffuse reflectance of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is SCE2, wherein, in combination with the depiction in FIG. 5b, after Visible light 300 incident from the side of the transparent substrate facing away from the light-absorbing substrate enters Transparent substrate 301, visible light will be reflected, absorbed and transmitted by the transparent substrate. The visible light transmitted through Transparent substrate 301 (the transmittance of the transparent substrate for visible light is T1 = (100%-R1) * (100%-A1) ) reaches Semi-reflective layer 302, and is further diffusely reflected by Semi-reflective layer 302 (in this case, the diffuse reflectance of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is R2) . The diffusely reflected visible light again reaches and passes through Transparent substrate 301 (in this case, the transmittance of the transparent substrate for visible light after diffuse reflection by the semi-reflective layer is (100%-R1) * (100%-A1) , for simplification, here it can be considered that the reflectance of visible light at the interface between the outside and the transparent substrate is the same as the reflectance of visible light at the interface between the transparent substrate and the outside, both of which are R1) . Therefore, the diffuse reflectance SCE2 of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate satisfies the relationship in Formula III.
SCE2 = (100%-R1) * (100%-A1) *R2 * (100%-R1) * (100%-A1) = [ (100%-R1) * (100%
-A1) ] ² *R2 Formula III

In the composite assembly of the present disclosure, a suitable diffuse reflectance SCE2 of the composite assembly for visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate helps to make the composite assembly of the present disclosure achieve excellent thermal comfort control effect.

In an embodiment, the diffuse reflectance SCE2 is from about 40%to about 90%. Such diffuse reflectance range is set to indicate that the composite assembly has a relatively high diffuse reflectance for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate, which helps to make the composite assembly of the present disclosure achieve excellent thermal comfort control effect.

Specifically, on one hand, the semi-reflective layer of the composite assembly diffusely reflects visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate at a high diffuse reflectance; on the other hand, the transparent substrate is highly transparent to visible light, and rarely absorbs visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate, which can ensure that visible light effectively reaches the semi-reflective layer, thereby enabling the semi-reflective layer to achieve diffuse reflection of the visible light with a high diffuse reflectance. Therefore, the transparent substrate in combination with diffuse reflection of the semi-reflective layer for visible light with a high diffuse reflectance enables the composite assembly of the present disclosure to have a relatively high diffuse reflectance for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate, thereby helping to achieve thermal comfort control effect.

In another embodiment, most of near-infrared light incident from the side of the transparent substrate facing away from the light-absorbing substrate can pass through the transparent substrate and reach the semi-reflective layer, and the semi-reflective layer has a high diffuse reflectance (greater than or equal to 55%) for the near-infrared light, which makes the composite assembly have a diffuse reflectance of about 55%to about 95%for the near-infrared light incident from the side of the transparent substrate facing away from the light-absorbing substrate. Such diffuse reflectance range for near-infrared light is set to indicate that the composite assembly has a relatively high diffuse reflectance for near-infrared light incident from a side of the transparent substrate facing away from the light-absorbing substrate, which also helps to make the composite assembly of the present disclosure achieve excellent thermal comfort control effect. Further, the composite assembly has a solar direct reflectance (RDS) of about 55%or more for diffuse reflection of sunlight incident from the side of the transparent substrate facing away from the light-absorbing substrate.

Diffuse Reflection of Composite Assembly for Visible Light Incident from a Side of Light-Absorbing Substrate facing away from Transparent Substrate

FIG. 6a shows a schematic diagram of Visible light 304 incident from a side of Light-absorbing substrate 303 facing away from Transparent substrate 301 being diffusely reflected by the composite assembly of the present disclosure. FIG. 6b shows a schematic diagram of visible light incident from a side of Light-absorbing substrate 303 facing away from Transparent substrate 301 being reflected (including diffusely reflected) , transmitted and absorbed by Light-absorbing substrate 303 and Semi-reflective layer 302.

Specifically, as shown in FIG. 6b, the composite assembly has a diffuse reflectance SCE1 for visible light incident from the side of Light-absorbing substrate 303 facing away from Transparent substrate 301, wherein after visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate enters Light-absorbing substrate 303, visible light transmitted through Light-absorbing substrate 303 (the transmittance of the light-absorbing substrate for visible light is T3) reaches Semi-reflective layer 302, and is further diffusely reflected by Semi-reflective layer 302 (in this case, the diffuse reflectance of the semi-reflective layer for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate is R4) . The diffusely reflected visible light again reaches and transmits through Light-absorbing substrate 303 (in this case, the transmittance of the light-absorbing substrate for visible light after being diffusely reflected by the semi-reflective layer is T5) . Therefore, the diffuse reflectance SCE1 of the composite assembly for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate satisfies the relationship in Formula IV.
SCE1 = T3 *R4 *T5 Formula IV

More specifically, when visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate passes through the light-absorbing substrate, visible light will be reflected, absorbed and transmitted by the light-absorbing substrate. Specifically, as shown in FIG. 6b, visible light is first reflected at the interface between the outside (e.g., air) and the light-absorbing substrate, and then absorbed by the light-absorbing substrate. Therefore, the transmittance T3 of the light-absorbing substrate for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate may be expressed as T3 = (100%-R3) * (100%-A3) , where R3 represents the reflectance of the light-absorbing substrate for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate. Specifically, as shown in FIG. 6b, R3 represents the reflectance of the interface between the outside (e.g., air) and the light-absorbing substrate for visible light, and A3 represents the absorbance of the light-absorbing substrate for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate. In an embodiment, A3 is greater than 16%. In another embodiment, A3 is less than 67%. In yet another embodiment, A3 is greater than 16%and less than 67%.

Similarly, when visible light diffusely reflected by the semi-reflective layer again reaches and transmits through the light-absorbing substrate, the visible light is reflected, absorbed and transmitted by the light-absorbing substrate. Specifically, as shown in FIG. 6b, visible light is first absorbed by the light-absorbing substrate and then reflected at the interface between the light-absorbing substrate and the outside (for example, air) , so that the transmittance T5 of the light-absorbing substrate for visible light diffusely reflected by the semi-reflective layer may be expressed as T5 = (100%-R5) * (100%-A5) , where R5 represents the reflectance of the light-absorbing substrate for visible light diffusely reflected by the semi-reflective layer. Specifically, as shown in FIG. 6b, R5 represents the reflectance of the interface between the light-absorbing substrate and the outside (for example, air) for visible light, and A5 represents the absorbance of the light-absorbing substrate for visible light diffusely reflected by the semi-reflective layer. Since the absorbance of the light-absorbing substrate for visible light remains unchanged when visible light diffusely reflected by the semi-reflective layer reaches and transmits through the light-absorbing substrate again, A3 = A5. Additionally, to simplify calculations, it can be considered that R3 = R5 based on average consideration. Thus, T5 = T3 = (100%-R3) * (100%-A3) .

Based on this, the diffuse reflectance SCE1 of the composite assembly for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate satisfies the relationship in Formula V, which is also the relationship in Formula V′.
SCE1 = (100%-R3) * (100%-A3) *R4 * (100%-R3) * (100%-A3) Formula V
SCE1 = [ (100%-R3) * (100%-A3) ] ² *R4 Formula V′

In an embodiment, the diffuse reflectance SCE1 is from about 10%to about 25%. Such diffuse reflectance range is set to balance projection display effect and light pollution control.

The inventors of the present disclosure unexpectedly found that, in the composite assembly of the present disclosure, for realizing excellent thermal comfort control effect and projection display effect of the composite assembly, the diffuse reflectance SCE1 of the composite assembly for visible light incident from a side of the light-absorbing substrate facing away from the transparent substrate is a key technical parameter. In particular, the composite assembly of the present disclosure adopts a design comprising a transparent substrate, a semi-reflective layer, and a light-absorbing substrate, wherein the absorbance of the light-absorbing substrate for visible light incident from a side of the light-absorbing substrate facing away from the transparent substrate (comprising the visible light entering the light-absorbing substrate for the first time and re-entering the light-absorbing substrate after being diffusely reflected by the semi-reflective layer) can significantly affect the diffuse reflectance of the composite assembly for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate. The light-absorbing substrate of the present disclosure is made of a suitable material, which has suitable transmittance, reflectance and absorbance for visible light from different directions, especially having a suitable absorbance, so that the composite assembly has a suitable diffuse reflectance for visible light incident from a side of the light-absorbing substrate facing away from the transparent substrate. As can be seen from the above, the semi-reflective layer has strong diffuse reflection for visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate, and even with the asymmetric stack design mentioned above, the semi-reflective layer still has strong diffuse reflection on its side facing towards the light-absorbing substrate. The light absorption property of the light-absorbing substrate can be beneficial to control the diffuse reflection on the side of light-absorbing substrate facing away from the transparent substrate, thereby achieving proper projection display brightness and avoiding potential light pollution.

Total Solar Transmittance of Composite Assembly for Sunlight Incident from a Side of Transparent Substrate facing away from Light-Absorbing Substrate

Because the transparent substrate, the semi-reflective layer, and the light-absorbing substrate exhibit specific reflectance (including diffuse reflectance) and transmittance, the composite assembly of the present disclosure has a low total solar transmittance (about 10%or less) and a high diffuse reflectance (about 55%or more) for sunlight incident from a side of the transparent substrate facing away from the light-absorbing substrate, which helps to achieve excellent thermal comfort effect for the composite assembly of the present disclosure, and can ensure a suitable ambient temperature on the side of the light-absorbing substrate facing away from the transparent substrate.

In an embodiment, the transparent substrate of the composite assembly is on a side facing towards sunlight, and the light-absorbing substrate of the composite assembly is on a side facing away from sunlight. That is, the transparent substrate is closer to sunlight than the light-absorbing substrate.

As an example, a composite assembly may be used in a vehicle where the transparent substrate of the composite assembly is on the side facing towards the exterior of the vehicle (i.e., the side facing towards sunlight incident from the outside of the vehicle) , while the light-absorbing substrate of the composite assembly is on the side facing towards the interior of the vehicle (i.e., the side facing towards visible light incident from the inside of the vehicle) . When the composite assembly of the present disclosure is used in a vehicle, sunlight from the outside of the vehicle can pass through the transparent substrate, the semi-reflective layer and the light-absorbing substrate, and in particular, visible light in sunlight undergoes the above reflection (mainly diffuse reflection) , transmission and absorption, so that the composite assembly of the present disclosure achieves excellent thermal comfort control effect. On the other hand, the light from the projection device inside the vehicle may also undergo the above reflection (mainly diffuse reflection) , transmission and absorption, so that the composite assembly of the present disclosure achieves excellent projection display effect. Exemplarily, when the composite assembly of the present disclosure is used as a vehicle window, the composite assembly may also have a specular transmission to visible light (for example, the composite assembly has smooth surfaces, a relatively low absolute value of refractive index difference between layers on two sides of the semi-reflective layer, and a textured first surface of the semi-reflective layer is parallel to the textured second surface (further preferably, each of the textured contacting surfaces of each layer in the semi-reflective layer in the form of a multilayer stack with its adjacent layers is parallel to one another) , to achieve desired specular transmission function.

The use of the composite assembly of the present disclosure in the skylight of the vehicle (the skylight glass at the top of the vehicle) is particularly advantageous because large-sized skylights and their application scenarios are more conducive to the composite assembly to achieve its excellent thermal comfort control effect and projection display effect.

Comprehensive Consideration of Reflection (including diffuse reflection) , Transmission and Absorption of Composite Assembly for Visible Light from Different Directions

Further, the diffuse reflection of the composite assembly for visible light incident from a side of the light-absorbing substrate facing away from the transparent substrate and the transmission of the composite assembly for visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate are comprehensively considered, so as to comprehensively optimize the diffuse reflectance of the semi-reflective layer for visible light incident from a side of the light-absorbing substrate facing away from the transparent substrate and the transmittance of the semi-reflective layer for visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate. Specifically, with reference to the above Formula II and Formula V, the inventor obtains the relationship in Formula VI, wherein the relationship in Formula VI-a can be obtained by combining Formula II with Formula V; and Formula VI-a can be further adjusted (adjustment of the mathematical relationship formula) to obtain the relationships in Formula VI-b and Formula VI.

In an embodiment, the transparent substrate has a reflectance R1 of about 3.8%to about 4.5%, preferably about 4%to about 4.2%, more preferably about 4%, for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate.

In an embodiment, the transparent substrate has an absorbance of about 0.5%to about 1.5%, preferably about 0.8%to about 1.2%, more preferably about 1%, for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate.

Based on this, [ (100%-R1) * (100%-A1) ] ² ranges from about 0.88 to about 0.92.

For example, in the case of an ordinary clear glass sheet with a thickness of 2.1 mm (e.g., an ordinary clear glass with a model of PLC (Planiclear) manufactured by Saint-Gobain) as an outer glass, together with a transparent PVB (polyvinyl butyral) layer for adhesion as a transparent substrate, R1 may be regarded as 4%, and A1 may be regarded as 1%. The relationship in Formula VI above can be further expressed as a relationship in Formula VII.

In an embodiment, the composite assembly has a diffuse reflectance SCE1 of about 10%to about 25%for visible light incident from a side of the light-absorbing substrate facing away from the transparent substrate. Such diffuse reflectance range is set to balance projection display effect and light pollution control.

In an embodiment, the composite assembly has a transmittance of about 0.5%to about 10%, preferably about 0.5%to about 2.5%, for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate. Such transmittance range is set to achieve functions such as privacy function, visibility to the outside function, and reducing interference of external ambient light on projection display.

As an example, a composite assembly may be used in a vehicle where the transparent substrate of the composite assembly is on the side facing towards the exterior of the vehicle (i.e., the side facing towards sunlight from the outside of the vehicle) , while the light-absorbing substrate of the composite assembly is on the side facing towards the interior of the vehicle (i.e., the side facing towards visible light from the inside of the vehicle) . In this case, the composite assembly has a transmittance TL of about 0.5%to about 10%for visible light in incident sunlight from the outside of the vehicle. In a specific embodiment, for all-weather projection display application inside a vehicle, due to the high intensity of sunlight outside the vehicle during the day (e.g., typically in the range of several thousand lux to 100,000 lux, and may be even higher in some regions) , the composite assembly has a transmittance TL of about 0.5%to 2.5%for visible light in incident sunlight from the outside of the vehicle, in order to meet the operational requirements of all-weather projection display. On the one hand, such a design can minimize the interference of the external ambient light on the projection display effect, and realize a clear view, and on the other hand, the transparency of the composite assembly can be maintained to allow observation of the external situation at any time. In addition, in the above use scenario, in order to balance the projection display effect and light pollution control of the composite assembly, the composite assembly has a diffuse reflectance SCE1 of about 10%to about 25%for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate. Therefore, based on the above application scenario, the reflection and the transmission of the composite assembly for visible light further satisfy the following relationship.

In a preferred embodiment, the reflection and the transmission of the composite assembly for visible light satisfy the following relationship.

In a more preferred embodiment, for example, for the above application scenario of the full-weather projection display, the reflection and the transmission of the composite assembly for visible light satisfy the following relationship.

When the composite assembly of the present disclosure satisfies the above relationship, the composite assembly can achieve balanced projection display effect and light pollution control, and can achieve privacy function, visibility to the outside function and reduce interference of external ambient light on projection display, which are unattainable technical effects of the composite assembly in the prior art.

In addition, the above Formulas VIII to VIII′″are used as core constraints for the design of the semi-reflective layer described below.

Further, the diffuse reflectance SCE2 of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate affects the thermal comfort control effect of the composite assembly.

In an embodiment, the composite assembly has a diffuse reflectance SCE2 of about 40%to about 90%for visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate. Such diffuse reflectance range is set to indicate that the composite assembly has a relatively high diffuse reflectance for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate, which helps to make the composite assembly of the present disclosure achieve excellent thermal comfort control effect.

Transmission, diffuse reflection of semi-reflective layer for visible light and technical effects of corresponding composite assembly

In the composite assembly of the present disclosure, suitable transmittance and diffuse reflectance of the semi-reflective layer for visible light are beneficial to make the composite assembly of the present disclosure achieve excellent thermal comfort control effect and projection display effect.

In order to enable the composite assembly of the present disclosure to achieve technical effects of excellent thermal comfort control and clear projection display, the semi-reflective layer in the composite assembly of the present disclosure may satisfy the following relationship.

According to the preceding Formula III, the following Inequality IX can be obtained, that is, the diffuse reflectance R2 of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is greater than the diffuse reflectance SCE2 of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate, i.e., R2>SCE2 (Formula IX) . As described above, the diffuse reflectance SCE2 of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is about 40%to about 90%. Thus, R2>SCE2=40%～90%, which indicates that the semi-reflective layer of the composite assembly needs to have a high diffuse reflection for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate.

According to the preceding Formula I, the following Inequality X can be obtained, that is, the transmittance T2 of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is greater than the transmittance TL of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate, i.e., T2>TL (Formula X) . As described above, when the transmittance TL of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is about 0.5%to about 10%, T2>TL=0.5%～10%. For the application scenario of the full-weather projection display, the transmittance TL of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is from about 0.5%to about 2.5%, and thus, T2>TL=0.5%～2.5%.

According to the preceding Formula IV, the following Inequality XI can be obtained, that is, the diffuse reflectance R4 of the semi-reflective layer for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate is greater than the diffuse reflectance SCE1 of the composite assembly for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate, i.e., R4>SCE1 (Formula XI) . As described above, the diffuse reflectance SCE1 of the composite assembly for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate is from about 10%to about 25%, and thus, R4>SCE1=10%～25%.

In addition to the above-mentioned Formulas VIII to VIII′″which are the core constraints for the design of the semi-reflective layer, the Inequalities IX-XI here are also the core constraints for design of the semi-reflective layer.

Although the diffuse reflectance R2 of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate may be different from the diffuse reflectance R4 of the semi-reflective layer for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate, the semi-reflective layer nevertheless has a high diffuse reflectance for visible light in a laminated state, which indicates that the semi-reflective layer requires a metal layer or metal alloy layer with high diffuse reflectance for visible light, such as an aluminum metal layer or a silver metal layer. Therefore, an aluminum single layer or a silver single layer in a laminated state is first investigated to find the case that matches all constraints, serving as the basis for the design of the semi-reflective layer.

As an example, the semi-reflective layer may be a metal layer, wherein the metal layer is a single-layer aluminum in a laminated state to form a semi-reflective single-layer metal layer. Since the semi-reflective layer is a single-layer metal layer and as described above, the media on the two sides of the semi-reflective layer have close or identical refractive indices, it can be considered that the diffuse reflectance R2 of the semi-reflective layer (i.e., single-layer metal layer) for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is equal to the diffuse reflectance R4 of the semi-reflective layer for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate.

Further, reference is made to document “Reference of optical index: A. D. Algorithm for the determination of intrinsic optical constants of metal films: application to aluminum, Appl. Opt. 34, 4755-4767 (1995) ” . The above laminated single-layer aluminum used as the semi-reflective metal layer is simulated and its simulation calculation results are shown in the following table.

Table 1 Simulation in Visible Light Range (incident angle 0o) of Laminated Single-Layer Aluminum as Metal Layer of Semi-Reflective Layer

According to the simulation calculation results in the above table, it can be seen that when laminated single-layer aluminum with different thicknesses starting from 10 nm thickness is used, it can satisfy the relationships in the above Formulas VIII to VIII′and Formulas IX-XI, and when laminated single-layer aluminum with different thicknesses starting from 20 nm thickness is used, it can meet the requirements for full-weather projection display, that is, it can satisfy the relationships in the above Formula VIII″and Formula VIII′″and Formulas IX-XI. Specifically, according to the results shown in Table 1, when the thickness of the laminated single-layer aluminum is 10 nm, the diffuse reflectance and transmittance of the laminated single-layer aluminum for visible light satisfy the relationships in Formula VIII and Formula VIII′and Formulas IX-XI. When the thickness of the laminated single-layer aluminum is 20 nm, the diffuse reflectance and the transmittance of the laminated single-layer aluminum for visible light meet the requirements for the full-weather projection display, that is, the diffuse reflectance and the transmittance of the laminated single-layer aluminum for visible light satisfy the relationships in Formula VIII″and Formula VIII′″, and furthermore, also satisfy the relationships in Formulas IX-XI. In the case where the thickness of the laminated single-layer aluminum is 20 nm, considering R1=R3 for simplification; and more specifically, a suitable material is selected, R1=R3=4%, A1=1%, and in this case the TL of the composite assembly may be 2%, then according to the relationships in Formula II, Formula III, and Formula V, in this case, the absorbance A3 of the light-absorbing substrate for the incident visible light is 55.44%, and the diffuse reflectance SCE1 of the composite assembly for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate is 14.54%, and the diffuse reflectance SCE2 of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is 71.81%, and all the above parameters meet the specified parameter range. It can be seen that when laminated single-layer aluminum is used as the metal layer of the semi-reflective layer, the obtained composite assembly can meet the above optical parameter range, and the composite assembly can achieve excellent thermal comfort and projection display effect.

In addition, the total solar transmittance (TTS) of laminated single-layer aluminum is also studied, and its simulation calculation results are shown in the following table.

Table 2 Simulation and Calculation of Laminated Single-Layer Aluminum in the Range of Ultraviolet-Visible-Near Infrared Light (incident angle 0°, ISO13837)

*AE represents the absorbance of a semi-reflective layer (i.e., laminated single-layer aluminum) to ultraviolet-visible-near infrared light

RE represents the reflectance of a semi-reflective layer (i.e., laminated single-layer aluminum) to ultraviolet-visible-near infrared light.

TE represents the transmittance of a semi-reflective layer (i.e., laminated single-layer aluminum) to ultraviolet-visible-near infrared light.

TTS represents the total solar transmittance of a semi-reflective layer (i.e., laminated single-layer aluminum)

According to the simulation calculation results in the above table, it can be found that when the thickness of the laminated single-layer aluminum is 20 nm or more, the laminated single-layer aluminum itself can already have a total solar transmittance lower than 10%, which also indicates that the total solar transmittance of the corresponding entire composite assembly will only be lower, which helps to make the composite assembly of the present disclosure achieve excellent thermal comfort control effect.

Further, a dielectric layer may be introduced into the semi-reflective layer, that is, in this case, in addition to the laminated single-layer aluminum described above, the semi-reflective layer further comprises a dielectric layer, so that a diffuse reflectance of the semi-reflective layer for visible light is different from a diffuse reflectance of the semi-reflective layer for near-infrared light. Such design may enable a relatively thick aluminum stacked semi-reflective layer (that is, the above-mentioned semi-reflective layer including laminated single-layer aluminum and dielectric layer) to have a similar diffuse reflectance for visible light as that of a thinner laminated single-layer aluminum, while maintaining a relatively high diffuse reflectance for near-infrared light. In such an embodiment, since the corresponding aluminum stacked semi-reflective layer has a lower total solar transmittance, it can effectively control the light energy and achieve excellent thermal comfort control effect. For example, if an aluminum stacked semi-reflective layer with a thickness of 25 nm with an introduced dielectric layer has a similar diffuse reflectance for visible light as that of a laminated single-layer aluminum with a thickness of 20 nm, the total solar transmittance TTS of such aluminum stacked semi-reflective layer can be between the total solar transmittance 9.6%of the laminated single-layer aluminum with a thickness of 20 nm and the total solar transmittance 6.77%of the laminated single-layer aluminum with a thickness of 25 nm.

In practical applications of the composite assembly of the present disclosure using aluminum as the metal layer in the semi-reflective layer to realize the thermal comfort control effect and the projection display effect of the composite assembly, the following several considerations may be included:

(1) Aluminum is a cheap and readily available material that can effectively save cost. Aluminum has a lower melting point (660℃) . When coated on a surface of a textured glass, it cannot withstand the high temperatures during thermal bending process of vehicle window glass. Therefore, preferably, aluminum may be suitable for being coated on a surface of a textured polymeric layer or on a surface of a textured glass that does not need to be subjected to thermal bending.

(2) In order to further improve the durability of the composite assembly, provide it with a colorful and aesthetic appearance, enable the semi-reflective layer to have an asymmetric stack design, and make the diffuse reflectance of the semi-reflective layer for visible light different from that for near-infrared light (as described in the previous paragraph) , etc., other metal or dielectric materials can be added to the semi-reflective layer including the single-layer aluminum.

(3) Since the aluminum in the semi-reflective layer helps the composite assembly achieve excellent thermal comfort control effect, there is still sufficient room for further design and research on the semi-reflective layer, so that the composite assembly has a proper appearance and thermal comfort control effect at the same time.

In another embodiment, as an example, the semi-reflective layer may be a metal layer, wherein the metal layer is a single-layer silver in a laminated state to form a semi-reflective single-layer metal layer. Similarly, since the semi-reflective layer is a single-layer metal layer and as described above, the media on the two sides of the semi-reflective layer have close or identical refractive indices, it can be considered that the diffuse reflectance R2 of the semi-reflective layer (i.e., single-layer metal layer) for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is equal to the diffuse reflectance R4 of the semi-reflective layer for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate.

Further, reference is made to document “Reference of optical index: P. B. Johnson and R. W. Christy. Optical constants of the noble metals, Phys. Rev. B 6, 4370-4379 (1972) ” .

Table 3 Simulation in Visible Light Range (incident angle 0°) of Laminated Single-Layer Silver as Metal Layer of Semi-Reflective Layer

Similar to the case of the laminated single-layer aluminum being used as the semi-reflective metal layer, when the laminated single-layer silver is used as the metal layer of the semi-reflective layer, when laminated single-layer silver with different thicknesses starting from the thickness of 25 nm is used as the semi-reflective metal layer, it can satisfy the relationships in the above Formulas VIII to VIII′and Formulas IX-XI. When the laminated single layer silver with different thicknesses starting from the thickness of 40 nm is used as the semi-reflective metal layer, it can meet the requirements for full-weather projection display, that is, it can satisfy the relationships in the above Formula VIII″and Formula VIII′″and Formulas IX-XI. In addition, similar to the case of the laminated single-layer aluminum being used as the semi-reflective metal layer, when the laminated single-layer silver is used as the semi-reflective metal layer, the obtained composite assembly can satisfy the corresponding optical parameter range, and the corresponding composite assembly can achieve excellent thermal comfort control effect and projection display effect.

In addition, similarly, other metal or dielectric materials may also be added to the semi-reflective layer including a single-layer silver to improve the durability of the composite assembly, provide it with a colorful and aesthetic appearance, enable the semi-reflective layer to have an asymmetric stack design, and make the diffuse reflectance of the semi-reflective layer for visible light different from that for near-infrared light to achieve a better thermal comfort control effect, and the like.

The above examples demonstrate that both aluminum and silver can be used as the substantially reflective layer of the semi-reflective layer in the composite assembly of the present disclosure. In addition, when aluminum and/or silver is used as the material of the semi-reflective layer, other materials (for example, other metal or dielectric materials) may be further introduced to form the semi-reflective stack layer, thereby bringing more desired functions for the composite assembly of the present disclosure, such as excellent projection display effect, thermal comfort control effect, excellent privacy effect, aesthetic appearance, enabling the semi-reflective layer to have an asymmetric stack design, making the diffuse reflectance of the semi-reflective layer for visible light different from its diffuse reflectance for near-infrared light to achieve a better thermal comfort control effect, etc. Preferably, the aluminum is cheap and readily available, so the cost of the composite assembly is low when aluminum is used as the material for the metal layer of the semi-reflective layer.

There are numerous designs for semi-reflective stacks that conform to specifications, which cannot be exhaustively described herein. Merely as examples and not as limitations, FIG. 7 and FIG. 8 illustrate two exemplary designs of semi-reflective stack layers using aluminum. In FIG. 7, the semi-reflective layer comprises Aluminum metal layer 704 (e.g., a thickness of 20 nm) , and SiOx (silicon oxide) as Dielectric layer 702 (e.g., a thickness of 20 nm) and Dielectric layer 705 (e.g., a thickness of 20 nm) , and further comprises a nickel-chromium alloy as Blocking layer 703 (e.g., a thickness of less than 1 nm) . Furthermore, in addition to the Semi-reflective layer, FIG. 7 also shows Polymeric layer 701 and Polymeric layer 706; a surface of Polymeric layer 706 facing towards the dielectric layer 705 is a textured surface; Dielectric layer 705 is formed on said textured surface. In the case of a vehicle window glass, Polymeric layer 701 may face towards the outside of a vehicle, and Polymeric layer 706 may face towards the inside of a vehicle. In FIG. 8, the semi-reflective layer comprises Aluminum metal layer 807 (e.g., a thickness of 20 nm) , and SiOx as Dielectric layer 802 (e.g., a thickness of 20 nm) and Dielectric layer 808 (e.g., a thickness of 20 nm) , TiOx (titanium oxide) as Dielectric layer 805 (e.g., a thickness of 60 nm) , nickel-chromium alloy as Blocking layer 803 (e.g., a thickness of less than 1 nm) and Blocking layer 806 (e.g., a thickness of less than 1 nm) , and further comprises copper as Absorption adjustment layer 804 (e.g., a thickness of 5 nm) , where the semi-reflective layer adopts an asymmetric design. Furthermore, in addition to the semi-reflective layer, FIG. 8 also shows Polymeric layer 801 and Polymeric layer 809; a surface of Polymeric layer 809 facing towards Dielectric layer 808 is a textured surface; Dielectric layer 800 is formed on said textured surface. In the case of a vehicle window glass, Polymeric layer 801 may face towards the outside of a vehicle, and Polymeric layer 809 may face towards the inside of a vehicle.

In addition, with the design shown in FIG. 8 and making Polymeric layer 801 face towards the outside of the vehicle and Polymeric layer 809 face towards the inside of the vehicle, the reflection and transmission colors for white visible light from the inside and outside of the vehicle are simulated and the CIE1931 color coordinate diagrams of FIG. 9 to FIG. 10 are obtained, respectively. The light sources in FIG. 9 and FIG. 10 are white light and the incident angle is 0°, the reference white is CIE-C, and the observer angle is 2°. Specifically, as shown in FIG. 9, the diffuse reflection chromaticity coordinates of the above design for the white visible light from the inside of the vehicle are (x = 0.328, y = 0.329) , and the transmission chromaticity coordinates for the white visible light from the inside of the vehicle are (x = 0.333, y = 0.345) . Both reflection and transmission are neutral. In addition, as shown in FIG. 10, the diffuse reflection chromaticity coordinates of the above design for the white visible light from the outside of the vehicle are (x = 0.306, y = 0.268) , and the transmission chromaticity coordinates for the white visible light from the outside of the vehicle are (x = 0.333, y = 0.345) . The reflection is chromatic, and the transmission is neutral. That is, the design shown in FIG. 8 uses the asymmetric design of the reflective layer to achieve different reflective colors on the two sides, while the transmission on both sides is neutral.

In summary, the composite assembly of the present disclosure comprises a transparent substrate, a semi-reflective layer, and a light-absorbing substrate, wherein the semi-reflective layer has a textured surface. Such a design facilitates the composite assembly of the present disclosure to achieve suitable diffuse reflectance for visible light incident from the two sides of the semi-reflective layer and a suitable transmittance for visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate.

Specifically, in one aspect, the transparent substrate of the composite assembly is highly transparent to visible light, which can transmit most of visible light. Therefore, most of visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate can transmit through the transparent substrate, while the semi-reflective layer with a textured surface has a high diffuse reflectance for visible light that transmits through the transparent substrate and reaches the semi-reflective layer. The above design enables the composite assembly of the present disclosure to have a high diffuse reflectance (about 40%to about 90%) for visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate, which helps achieving good thermal comfort on the side of the light-absorbing substrate facing away from the transparent substrate. In addition, since the reflection of visible light by the semi-reflective layer is diffuse reflection rather than specular reflection, the composite assembly can effectively avoid optical pollution while achieving the above high diffuse reflectance. Further, visible light transmitted through the semi-reflective layer is further absorbed by the light-absorbing substrate, so that the composite assembly has a lower transmittance for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate, e.g., only about 0.5%to about 10%. The relatively low visible light transmittance helps to make the composite assembly of the present disclosure achieve, for example, privacy function, and reduce interference of external ambient light on projection display on the side of the light-absorbing substrate. On the other hand, the light-absorbing substrate of the composite assembly is capable of absorbing a certain degree of visible light, so it can properly absorb visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate (including absorbing visible light diffusely reflected by the semi-reflective layer) , and thus the composite assembly has a suitable diffuse reflectance (about 10%to about 25%) for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate. Such a design helps to control the diffuse reflection intensity of visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate, thereby helping to achieve a suitable projection display brightness on the side of the light-absorbing substrate facing away from the transparent substrate, and avoiding potential light pollution on the side of the light-absorbing substrate facing away from the transparent substrate.

Method for Preparing Composite Assembly

At least one layer of one of a light-absorbing substrate and a transparent substrate is provided. One surface of one layer of the at least one layer of the one of the light-absorbing substrate and the transparent substrate is formed into a textured surface and a semi-reflective layer is formed on the textured surface. At least one layer of the other one of the light-absorbing substrate and the transparent substrate is formed on a surface of the semi-reflective layer facing away from the one layer of the at least one layer of the one of the light-absorbing substrate and the transparent substrate, to obtain at least a portion of the composite assembly. Optionally, other layers of the light-absorbing substrate and the transparent substrate are further provided to obtain the composite assembly. Optionally, the one layer of the at least one layer of the one of the light-absorbing substrate and the transparent substrate is a polymeric layer or a glass substrate.

In an embodiment, at least one layer of a light-absorbing substrate is provided, one surface of one layer of the at least one layer of the light-absorbing substrate is formed into a textured surface and a semi-reflective layer is formed on the textured surface, at least one layer of a transparent substrate is formed on a surface of the semi-reflective layer facing away from the one layer of the at least one layer of the light-absorbing substrate, to obtain at least a portion of the composite assembly, optionally, other layers of the light-absorbing substrate and the transparent substrate are further provided to obtain the composite assembly. In an embodiment, the one layer of the at least one layer of the light-absorbing substrate is a polymeric layer or a glass substrate.

The texture of the contacting surface of the semi-reflective layer in contact with the light-absorbing substrate is complementary to the texture of the textured surface of the one layer of the light-absorbing substrate. According to the material of the one layer of the light-absorbing substrate, the one layer of the light-absorbing substrate may be processed by a corresponding process to form a textured surface on one surface of the one layer of the light-absorbing substrate.

For example, when the one layer of the light-absorbing substrate is a glass substrate, the texture may be obtained by a process such as acid etching, sand blasting, laser etching, etc.

For another example, when the one layer of the light-absorbing substrate is a polymeric layer, a pre-designed texture may be formed on one surface of the polymeric layer by, e.g., imprint, so as to obtain a textured surface of the polymeric layer. For example, the texture may be obtained using nanoimprint having advantages such as high efficiency, high resolution, etc., and the nanoimprint technology applicable herein comprises, but is not limited to, UV nanoimprint, thermal nanoimprint, mold compression nanoimprint, and the like. For another example, a textured surface may also be formed on one surface of the polymeric layer by a transfer print technology, such as UV transfer print. Further, the use of a texture printer with a roll to roll function can effectively improve the manufacturing efficiency.

In another embodiment, at least one layer of a transparent substrate is provided, one surface of one layer of the at least one layer of the transparent substrate is formed into a textured surface and a semi-reflective layer is formed on the textured surface, at least one layer of a light-absorbing substrate is formed on a surface of the semi-reflective layer facing away from the one layer of the at least one layer of the transparent substrate, to obtain at least a portion of the composite assembly, optionally, other layers of the light-absorbing substrate and the transparent substrate are further provided to obtain the composite assembly. In an embodiment, the one layer of the at least one layer of the transparent substrate is a polymeric layer or a glass substrate.

The texture of the contacting surface of the semi-reflective layer in contact with the transparent substrate is complementary to the texture of the textured surface of the one layer of the transparent substrate. The textured surface may be formed on the surface of the one layer of the transparent substrate by the same method. According to the material of the one layer of the transparent substrate, the one layer of the transparent substrate may be processed by a corresponding process to form a textured surface on one surface of the one layer of the transparent substrate.

For example, when the one layer of the transparent substrate is a glass substrate, the texture may be obtained by a process such as acid etching, sand blasting, laser etching, etc.

For another example, when the one layer of the transparent substrate is a polymeric layer, a pre-designed texture may be formed on one surface of the polymeric layer by, e.g., imprint, so as to obtain a textured surface of the polymeric layer. For example, the texture may be obtained using nanoimprint having advantages such as high efficiency, high resolution, etc., and the nanoimprint technology applicable herein comprises, but is not limited to, UV nanoimprint, thermal nanoimprint, mold compression nanoimprint, and the like. For another example, a textured surface may also be formed on one surface of the polymeric layer by a transfer print technology, such as UV transfer print. Further, the use of a texture printer with a roll to roll function can effectively improve the manufacturing efficiency.

For another example, when the one layer is a polymeric layer, a textured surface is formed on one surface of the polymeric layer, and a semi-reflective layer is formed on the textured surface, and then another polymeric layer in contact with the semi-reflective layer (as, e.g., at least one layer of the other one of the light-absorbing substrate and the transparent substrate) may be prepared by wet coating, including but not limited to slit coating, curtain coating, blade coating, roller coating, spray coating, spin coating, screen printing, and the like. Specifically, a raw material (which may be a material having suitable fluidity) for forming the another polymeric layer may be applied onto the semi-reflective layer, and the raw material can sufficiently fill the textured surface of the semi-reflective layer by its fluidity, and then the another polymeric layer may be formed by curing, so that one smooth surface of the another polymeric layer may be formed.

The curing method is not particularly limited in the present disclosure, and the curing method commonly used in the field may be selected according to the properties of the specifically used polymeric layer, e.g., thermal curing, UV light curing, electron beam curing, etc. There is almost no mass loss before and after the completion of UV light curing. Forming a polymeric layer by UV light curing generates a relatively low stress for, e.g., the glass film. And UV light curing can be performed at room temperature. Based on the above characteristics of UV light curing, the formation of the polymeric layer by UV light curing does not cause obvious internal stress of, e.g., the glass film, so that the glass film is less likely to be damaged in the subsequent lamination process, which also facilitates mass production.

In a preferred embodiment, the contacting surface of the semi-reflective layer in contact with the transparent substrate (i.e., the textured first surface of the semi-reflective layer) is parallel to the textured second surface (the textured surfaces being parallel means that the textures are parallel to each other) . Further preferably, each of the textured contacting surfaces in the composite assembly is parallel to one another. To ensure parallelism of the each textured contacting surface in the composite assembly, the semi-reflective layer can be formed by, e.g., physical vapor deposition, preferably by cathode sputtering deposition. The cathode sputtering, especially the magnetic field enhanced cathode sputtering, can ensure that the textured first surface of the semi-reflective layer and the textured second surface are parallel to each other, thereby ensuring the parallelism of each textured contacting surface in the semi-reflective layer.

Window Assembly

In another aspect, the present disclosure is related to a window assembly comprising the composite assembly of the present disclosure.

In an embodiment, the window assembly comprises a door, a window, a curtain wall, a vehicle window glass, an airplane glass or a ship glass. In a preferred embodiment, the window assembly is a vehicle window glass, and the vehicle window glass comprises a rear windshield, a skylight glass, a vehicle door glass or a corner window glass. In a more preferred embodiment, the vehicle window glass is a skylight glass.

In a specific embodiment, in the window assembly, the transparent substrate faces towards the outside of a vehicle and the light-absorbing substrate faces towards the inside of the vehicle. In a more specific embodiment, the vehicle window glass has specular transmission to visible light.

In a specific embodiment, the transparent substrate in the window assembly faces towards the sunlight source, and the light-absorbing substrate in the window assembly faces away from the sunlight source.

Vehicle

In another aspect, the present disclosure relates to a vehicle comprising the window assembly of the present disclosure, further comprising a projection device, wherein a projection light of the projection device faces towards the light-absorbing substrate of the window assembly for forming a projection image on a side of the semi-reflective layer facing towards the light-absorbing substrate.

It will be appreciated that the embodiments shown in the figures herein only show optional configurations, shapes, sizes and arrangements of the composite assembly, glass assembly and window assembly according to the present disclosure while they are provided only for illustration rather than limitation. Other shapes, sizes and arrangements may be adopted without departing from the concept and scope of the present disclosure.

The technical contents and technical features of the present disclosure have been disclosed above. However, it can be understood that those skilled in the art can make various changes and improvements to the above disclosed concept under the creative idea of the present disclosure, all of which fall within the protection scope of the present disclosure. The description of the above embodiments is illustrative rather than restrictive, and the protection scope of the present disclosure is determined by the claims.

Claims

A composite assembly comprising:

a transparent substrate,

a semi-reflective layer, and

a light-absorbing substrate;

wherein,

the semi-reflective layer is located between the transparent substrate and the light-absorbing substrate,

the semi-reflective layer has a textured first surface and a textured second surface,

the transparent substrate is in contact with the first surface of the semi-reflective layer, the contacting surface of the transparent substrate is textured, and the texture is complementary to the texture of the first surface of the semi-reflective layer; and

the light-absorbing substrate is in contact with the second surface of the semi-reflective layer, the contacting surface of the light-absorbing substrate is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer;

the transparent substrate is closer to an external visible light source than the light-absorbing substrate.
The composite assembly according to claim 1, wherein

the composite assembly is used as a projection screen, and the light-absorbing substrate faces towards a projection light for forming a projection image on a side of the semi-reflective layer facing towards the light-absorbing substrate.
The composite assembly according to claim 1 or 2, wherein

the composite assembly consists of the transparent substrate, the semi-reflective layer, and the light-absorbing substrate.
The composite assembly according to any one of claims 1-3, wherein

the composite assembly has a diffuse reflectance of about 10%to about 25%for visible light incident from a side of the light-absorbing substrate facing away from the transparent substrate; and/or

the composite assembly has a diffuse reflectance of about 40%to about 90%for visible light incident from a side of the transparent substrate facing away from the light-absorbing substrate; and/or

the composite assembly has a total solar transmittance of about 10%or less for sunlight incident from a side of the transparent substrate facing away from the light-absorbing substrate; and/or

the composite assembly has a solar direct reflectance (RDS) of about 55%or more for diffuse reflection of sunlight incident from the side of the transparent substrate facing away from the light-absorbing substrate.
The composite assembly according to any one of claims 1-4, wherein

the composite assembly has a transmittance of about 0.5%to about 10%, preferably about 0.5%to about 2.5%, for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate; and/or

the composite assembly has a diffuse reflectance of about 55%to about 95%for near-infrared light incident from the side of the transparent substrate facing away from the light-absorbing substrate; and/or

the composite assembly has a haze of about 10%or less, preferably about 5%or less.
The composite assembly according to any one of claims 1-5, wherein

the diffuse reflectance of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is greater than the diffuse reflectance of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate; and/or

the transmittance of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate is greater than the transmittance of the composite assembly for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate; and/or

the diffuse reflectance of the semi-reflective layer for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate is greater than the diffuse reflectance of the composite assembly for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate.
The composite assembly according to any one of claims 1-6, wherein

the transparent substrate has a reflectance of about 3.8%to about 4.5%, preferably about 4%to about 4.2%, more preferably about 4%, for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate; and/or

the transparent substrate has an absorbance of about 0.5%to about 1.5%, preferably about 0.8%to about 1.2%, more preferably about 1%, for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate.
The composite assembly according to any one of claims 1-7, wherein

the reflection and the transmission of the composite assembly for visible light satisfy the following relationship:

preferably, the reflection and the transmission of the composite assembly for visible light satisfy the following relationship:

more preferably, the reflection and the transmission of the composite assembly for visible light satisfy the following relationship:

particularly preferably, the reflection and the transmission of the composite assembly for visible light satisfy the following relationship:

wherein

R4 represents the diffuse reflectance of the semi-reflective layer for visible light incident from the side of the light-absorbing substrate facing away from the transparent substrate,

T2 represents the transmittance of the semi-reflective layer for visible light incident from the side of the transparent substrate facing away from the light-absorbing substrate.
The composite assembly according to any one of claims 1-8, wherein

the textured first surface is parallel to the textured second surface.
The composite assembly of claim 9, wherein

the textured first surface and/or the textured second surface has a root mean square slope of profile of about 1o to about 20o.
The composite assembly according to any one of claims 1-10, wherein

the light-absorbing substrate comprises at least one light-absorbing layer, one surface of one of the light-absorbing layer (s) is in contact with the second surface of the semi-reflective layer, the contacting surface of said one of the light-absorbing layer (s) is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer; or

the light-absorbing substrate comprises at least one light-absorbing layer and at least one transparent layer, one surface of one of the light-absorbing layer (s) or one of the transparent layer (s) is in contact with the second surface of the semi-reflective layer, the contacting surface of said one of the light-absorbing layer (s) or said one of the transparent layer (s) is textured, and the texture is complementary to the texture of the second surface of the semi-reflective layer.
The composite assembly according to any one of claims 1-11, wherein

the transparent substrate comprises at least one transparent layer, one surface of one of the transparent layer (s) is in contact with the first surface of the semi-reflective layer, the contacting surface of said one of the transparent layer (s) is textured, and the texture is complementary to the texture of the first surface of the semi-reflective layer, and

all the layers comprised in the transparent substrate are transparent layers.
The composite assembly according to any one of claims 1-12, wherein

the light-absorbing substrate comprises any one of a glass substrate, an adhesive layer, a switchable film, a polymeric layer and a film substrate layer or any combination thereof;

the transparent substrate comprises any one of a glass substrate, an adhesive layer, a polymeric layer, and a film substrate layer or any combination thereof;

preferably, the glass substrate comprises any one of a soda-lime-silica float glass, a borosilicate glass, an aluminosilicate glass, a glass-ceramic glass, and a polycarbonate glass or any combination thereof, more preferably a soda-lime-silica float glass; and/or

the adhesive layer comprises any one of an optical adhesive, a thermoplastic polymer, and a pressure-sensitive adhesive or any combination thereof, more preferably any one of polyvinyl butyral, ethylene vinyl acetate copolymer, thermoplastic polyurethane elastomer, and an ionic intermediate film or any combination thereof; and/or

the switchable film comprises any one of a dye-doped polymer dispersed liquid crystal switchable film, a suspended particle switchable film, an electrochromic switchable film, and a guest-host liquid crystal switchable film or any combination thereof, and more preferably a guest-host liquid crystal switchable film; and/or

the polymeric layer comprises any one of polyester, polyacrylate, polycarbonate, polyurethane, polyamide, polyimide, photocrosslinked and/or photopolymerized resin, and polythiourethane or any combination thereof; and/or

the film substrate layer comprises any one of a glass film and a thermoplastic polymer film or any combination thereof;

more preferably, the thermoplastic polymer film comprises any one of polyethylene terephthalate, polymethyl methacrylate, polyimide and cyclo olefin polymer or any combination thereof;

particularly preferably,

the glass film has a thickness of about 25 μm to about 200 μm; and/or

the thermoplastic polymer film has a thickness of about 0.15 mm to about 0.25 mm.
The composite assembly according to any one of claim 1-13, wherein

the semi-reflective layer is a single layer or a multilayer stack,

the single layer is a metal layer or a metal alloy layer,

the multilayer stack comprises at least one metal layer or metal alloy layer, each of the contacting surfaces of each layer with its adjacent layers in the multilayer stack is textured, and the texture of each of the contacting surfaces is complementary to the texture of its adjacent contacting surface;

preferably,

the metal layer comprises any one of aluminum, silver and molybdenum or any combination thereof; the metal alloy layer comprises any one of aluminum alloy, silver alloy and molybdenum alloy or any combination thereof;

more preferably,

each of the textured contacting surfaces of each layer with its adjacent layers in the multilayer stack is parallel to one another.
The composite assembly according to claim 14, wherein

the semi-reflective layer further comprises

a blocking layer located on one side of the metal layer or the metal alloy layer or on both sides of the metal layer or the metal alloy layer, each of the contacting surfaces of the blocking layer with its adjacent layers being textured, and the texture being complementary to the texture of its adjacent contacting surface; and/or

a dielectric layer, each of the contacting surfaces of the dielectric layer with its adjacent layers being textured, and the texture being complementary to the texture of its adjacent contacting surface; and/or

an absorption adjustment layer, each of the contacting surfaces of the absorption adjustment layer with its adjacent layers being textured, and the texture being complementary to the texture of its adjacent contacting surface, the blocking layer is located on one side of the absorption adjustment layer or on both sides of the absorption adjustment layer;

preferably,

the blocking layer comprises any one of nickel, chromium, titanium, and nickel-chromium alloy or any combination thereof;

the dielectric layer comprises an oxide, a nitride, a sulfide or a carbide of a metal or an inorganic non-metal;

the absorption adjustment layer comprises any one of copper, and gold or any combination thereof.
The composite assembly according to any one of claims 11-15, wherein

a first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is a glass substrate, and a first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a polymeric layer or an adhesive layer; or

a first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is a polymeric layer, and a first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a polymeric layer or an adhesive layer or a glass substrate; or

a first transparent layer of the transparent substrate in contact with the first surface of the semi-reflective layer is an adhesive layer, and a first transparent layer or light-absorbing layer of the light-absorbing substrate in contact with the second surface of the semi-reflective layer is a polymeric layer or a glass substrate.
The composite assembly according to claim 16, wherein

the light-absorbing substrate further comprises a second light-absorbing layer or transparent layer, which is in contact with the first transparent layer or light-absorbing layer of the light-absorbing substrate on a side of the first transparent layer or light-absorbing layer of the light-absorbing substrate facing away from the semi-reflective layer,

when the first transparent layer or light-absorbing layer of the light-absorbing substrate is a polymeric layer, the second light-absorbing layer or transparent layer is an adhesive layer, optionally, the light-absorbing substrate further comprises a glass substrate or a switchable film in contact with the adhesive layer on a side of the adhesive layer facing away from the polymeric layer; or the second light-absorbing layer or transparent layer is a film substrate layer, optionally, the light-absorbing substrate further comprises an adhesive layer in contact with the film substrate layer on a side of the film substrate layer facing away from the polymeric layer, further optionally, the light-absorbing substrate further comprises a glass substrate or a switchable film in contact with the adhesive layer on a side of the adhesive layer facing away from the film substrate layer;

when the first transparent layer or light-absorbing layer of the light-absorbing substrate is an adhesive layer, the second light-absorbing layer or transparent layer is a glass substrate or a switchable film.
The composite assembly according to claim 16 or 17, wherein

the transparent substrate further comprises a second transparent layer, which is in contact with the first transparent layer of the transparent substrate on a side of the first transparent layer of the transparent substrate facing away from the semi-reflective layer,

when the first transparent layer of the transparent substrate is a polymeric layer, the second transparent layer is an adhesive layer, optionally, the transparent substrate further comprises a glass substrate in contact with the adhesive layer on a side of the adhesive layer facing away from the polymeric layer; or the second transparent layer is a film substrate layer, optionally, the transparent substrate further comprises an adhesive layer in contact with the film substrate layer on a side of the film substrate layer facing away from the polymeric layer, further optionally, the transparent substrate further comprises a glass substrate in contact with the adhesive layer on a side of the adhesive layer facing away from the film substrate layer;

when the first transparent layer of the transparent substrate is an adhesive layer, the second transparent layer is a glass substrate.
A method for preparing the composite assembly according to any one of claims 1-18, comprising

providing at least one layer of one of a light-absorbing substrate and a transparent substrate,

forming one surface of one layer of the at least one layer of the one of the light-absorbing substrate and the transparent substrate into a textured surface and forming a semi-reflective layer on the textured surface,

forming at least one layer of the other one of the light-absorbing substrate and the transparent substrate on a surface of the semi-reflective layer facing away from the one layer of the at least one layer of the one of the light-absorbing substrate and the transparent substrate,

to obtain at least a portion of the composite assembly;

optionally, further providing other layers of the light-absorbing substrate and the transparent substrate to obtain the composite assembly;

optionally, the one layer of the at least one layer of the one of the light-absorbing substrate and the transparent substrate is a polymeric layer or a glass substrate.
A window assembly, comprising the composite assembly according to any one of claims 1-18.
The window assembly according to claim 20, wherein

the window assembly comprises a door, a window, a curtain wall, a vehicle window glass, an airplane glass or a ship glass.
The window assembly according to claim 21, wherein the window assembly is a vehicle window glass, and the vehicle window glass comprises a rear windshield, a skylight glass, a vehicle door glass or a corner window glass, preferably a skylight glass.
The window assembly according to claim 22, wherein the transparent substrate faces towards the outside of a vehicle and the light-absorbing substrate faces towards the inside of the vehicle.
The window assembly according to any one of claims 20-23, wherein

the transparent substrate in the window assembly faces towards a sunlight source, and the light-absorbing substrate in the window assembly faces away from the sunlight source.
A vehicle, comprising the window assembly according to any one of claims 22-24, further comprising a projection device, wherein a projection light of the projection device faces towards the light-absorbing substrate of the window assembly for forming a projection image on a side of the semi-reflective layer facing towards the light-absorbing substrate.