KR102183681B1 - Preparation Method for Alignable Substrate - Google Patents

Abstract

The present application provides a method of manufacturing an oriented substrate with improved rubbing process. In this application, since damage to the rubbing cloth can be prevented, the replacement cycle of the rubbing cloth is lengthened, the outer part and the electrode part can be cut at the same time, reducing the process time, and the problem that the rubbing line is recognized when voltage is applied does not occur. As a result, optical properties can be improved, and a method for manufacturing an oriented substrate which is advantageous also for manufacturing a free-shaped optical device can be provided.

Description

Preparation Method for Alignable Substrate {Preparation Method for Alignable Substrate}

The present application relates to a method of manufacturing an oriented substrate.

An alignment film capable of controlling the alignment of liquid crystals mainly included in the optical modulation layer is formed on the surface of the substrate included in the optical device. The alignment treatment of the alignment layer may be performed by a rubbing process.

When manufacturing an optical device, it is necessary to cut the electrode part to connect the driving circuit. After cutting the electrode, a step occurs in the substrate. If the cut surface is sharp and rubs the cut several times, the rubbing cloth may be worn. In addition, if the alignment layer debris remains in the cut area and accumulates on the rubbing cloth, the alignment layer may be damaged or the alignment layer may be peeled off during rubbing.

In addition, when the optical device is manufactured after rubbing with the rubbing cloth worn or the alignment layer debris accumulated, the initial transmittance may be different from that of other parts, and the driving speed may be different when applying a voltage, so that a rubbing line may be visually recognized.

In addition, the current manufacturing process of an optical device such as a liquid crystal cell is divided into the first cutting of the outer part, rubbing, and the second cutting of the electrode part, which takes a lot of time.

Korean Patent Registration Publication No. 10-0880214 Korean Patent Publication No. 2012-0011711

The present application provides a method of manufacturing an oriented substrate with improved rubbing process. In this application, since damage to the rubbing cloth can be prevented, the replacement cycle of the rubbing cloth is lengthened, the outer part and the electrode part can be cut at the same time, reducing the process time, and the problem that the rubbing line is recognized when voltage is applied does not occur. It is an object of the present invention to provide a method for manufacturing an oriented substrate that can improve optical properties and is advantageous also for manufacturing a free-shaped optical device.

The present application relates to a method of manufacturing an oriented substrate. The term alignment substrate refers to a substrate to which an alignment force capable of aligning a liquid crystal is imparted to the surface. In one example, the oriented substrate may be used to manufacture an optical device.

In the scope of the term optical device, it is possible to switch between two or more different optical states, e.g., high transmittance and low transmittance states, high transmittance, medium transmittance and low transmittance states, states in which different colors are implemented, etc. All types of devices formed to be configured may be included.

In the present specification, when the terms such as vertical, horizontal, orthogonal or parallel are used while defining an angle, this means substantially vertical, horizontal, orthogonal or parallel within a range that does not impair the desired effect, for example , Manufacturing errors or variations are included. For example, in each of the above cases, an error within about ±15 degrees, an error within about ±10 degrees, or an error within about ±5 degrees may be included.

The method of manufacturing an oriented substrate of the present application may include inserting a protrusion into a cutting portion of a substrate including an electrode film and an alignment layer, and rubbing the alignment layer using a rubbing roll having a rubbing cloth. In this case, the rubbing treatment may be performed to satisfy the relationship of Equation 1 below.

[Equation 1]

A <B <(C+A)

In Equation 1, A is the thickness of the substrate, B is the height of the protrusion, and C is the thickness of the rubbing cloth. In the above, the thickness (A) of the substrate means the total value of the thickness of the electrode film and the thickness of the alignment layer.

According to the present application, by applying the protrusion to the cutting portion and performing the rubbing treatment to satisfy Equation 1, damage to the rubbing cloth by the cutting portion during the rubbing treatment can be prevented. According to the present application, since damage to the rubbing cloth can be prevented, there is an advantageous effect of lengthening the replacement cycle of the rubbing cloth. In addition, according to the present application, it is possible to cut the outer portion and the electrode portion at the same time, there is an advantageous effect that can shorten the process time. That is, in the present application, damage to the rubbing fabric can be prevented even if the substrate having the cutting portion is subjected to the rubbing treatment, so that the rubbing treatment can be performed after cutting the electrode portion, so that the cutting process of the outer portion and the electrode portion can be reduced to one. Further, according to the present application, it may be advantageous for manufacturing an optical device having excellent optical properties. That is, in the present application, not only can damage to the rubbing fabric be prevented, but since the rubbing fabric does not directly contact the cutting portion, accumulation of alignment layer debris in the rubbing fabric can be reduced. Accordingly, since the rubbing intensity is changed to the alignment layer, the driving speed is changed when the voltage is applied, so that a defect in which the rubbing line is recognized may not occur. In addition, according to the present application, even if rubbing is performed in various directions, a difference in the degree of wear of the rubbing cloth does not occur, and thus it may be advantageous to manufacture a free-shaped optical device.

Hereinafter, a method of manufacturing the oriented substrate of the present application will be described in detail.

The electrode film may include a base film and a transparent conductive layer on the base film. The thickness of the transparent conductive layer may be appropriately selected in consideration of the thickness (A) of the substrate of Equation 1, and may be, for example, 10 nm to 100 nm. In addition, the thickness of the base film may be appropriately adjusted to satisfy the range of the thickness (A) of the substrate of Equation 1 in consideration of the thickness of the transparent conductive layer and the thickness of the alignment layer to be described later.

As the base film, any base film used as a substrate for a known optical device such as a liquid crystal cell may be applied. Various plastic films may be exemplified as the base film. As a plastic film, a triacetyl cellulose (TAC) film; Cycloolefin copolymer (COP) films such as norbornene derivatives; Acrylic film such as PMMA (poly(methyl methacrylate)); PC (polycarbonate) film; Polyolefin film such as PE (polyethylene) or PP (polypropylene); PVA (polyvinyl alcohol) film; DAC (diacetyl cellulose) film; Pac (Polyacrylate) Film; PES (polyether sulfone) film; PEEK (polyetheretherketon) film; PPS (polyphenylsulfone) film, PEI (polyetherimide) film; PEN (polyethylenemaphthatlate) film; PET (polyethyleneterephtalate) film; PI (polyimide) film; PSF (polysulfone) A film or a polyarylate (PAR) film may be exemplified, but is not limited thereto.

As the transparent conductive layer, any transparent conductive layer used in the electrode layer of a known optical device such as a liquid crystal cell can be used. As an example, the transparent conductive layer may include a transparent conductive material such as a conductive polymer, a conductive metal, a conductive nanowire, or a metal oxide. In one example, the transparent conductive layer is transparent such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), AZO (Aluminium Zinc Oxide), GZO (Gallium Zinc Oxide), ATO (Antimony Tin Oxide) or SnO ₂ It may contain a metal oxide.

The alignment layer may be formed on the electrode film, specifically on the transparent conductive layer. The thickness of the alignment layer may be appropriately selected in consideration of the thickness (A) of the substrate of Equation 1, and may be, for example, 50 nm to 300 nm.

The alignment layer may be formed on the electrode film to adjust the alignment of the liquid crystal compound. The type of alignment layer applied in the present application is not particularly limited, and a known alignment layer may be used. For example, it satisfies appropriate coating properties, solubility in solvents, heat resistance, chemical resistance, and durability against orientation treatment such as rubbing, and shows appropriate tilting properties as needed, and impurity management All known alignment layers satisfying physical properties such as an appropriate voltage holding ratio (VHR) and a high contrast ratio may be applied.

The alignment layer may be, for example, a vertical or horizontal alignment layer. As the vertical or horizontal alignment layer, any alignment layer having vertical or horizontal alignment capability with respect to the liquid crystal compound of the adjacent liquid crystal layer may be selected and used without particular limitation.

The alignment layer may include any kind of material known to be capable of exhibiting alignment ability such as vertical or horizontal alignment ability with respect to liquid crystal by rubbing treatment. For example, the alignment layer is a polyimide compound, a poly(vinyl alcohol) compound, a poly(amic acid) compound, a polystylene compound, a polyamide compound, and a poly It may include an alignment layer forming material known to exhibit alignment ability by rubbing alignment such as an oxyethylene compound.

The alignment layer is an alignment layer forming material containing an alignment layer forming material, for example, an alignment layer forming material prepared by dispersing, diluting and/or dissolving an alignment layer forming material in an appropriate solvent, that is, forming an alignment layer containing an alignment layer forming material and a solvent It can be formed in a known manner by applying ash.

In the present application, the alignment layer is formed by using the alignment layer forming material as described above, and in this case, a method of forming the alignment layer is not particularly limited. For example, the alignment layer forming process may include a process of forming a layer of an alignment layer forming material on the electrode film and performing a known treatment such as an alignment treatment on the formed layer. In addition, when the layer of the alignment layer forming material is formed by coating or the like, and the time until firing is not constant for each substrate, or if it is not fired immediately after application, a pretreatment process such as a drying process may be performed. For example, processes such as drying and/or heat treatment may be performed using an appropriate dryer, oven, or hot plate.

The thickness of the alignment layer formed by the above process is, for example, about 50 nm or more and about 1,000 nm or less, 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less, 400 nm or less. , The thickness may be adjusted within a range of 300 nm or less or 200 nm or less.

FIG. 1 exemplarily shows a structure in which a protrusion 30 is inserted into a cutting portion of a substrate 100 including an electrode film 10 and an alignment layer 20.

The cutting portion may be formed by cutting the electrode portion in order to connect the driving circuit when manufacturing the optical device. In this specification, a portion cut out of the substrate and cut out may be referred to as a cutting portion. The substrate may have at least one cutting portion. The number of cutting parts can be appropriately adjusted in consideration of the connection of the driving circuit.

As an example, the cutting part may exist in an inner area of the substrate. When the cut substrate is viewed from above, the cut portion may have a shape surrounded by the non-cut portion. The shape of the cross section of the cutting portion is not particularly limited, and may have, for example, a free shape such as a polygonal shape of an irregular shape or a curved shape of an irregular shape, as well as a standardized shape such as polygonal, circular, and elliptical shape. The area of the cut part on the substrate can be appropriately changed in design according to the product to be manufactured.

The cutting portion may be formed by a known cutting method performed to connect a driving circuit during manufacture of an optical device. As an example, the cutting portion of the substrate may be formed by cutting performed in the thickness direction of the substrate through known physical cutting. The cutting of the substrate may be performed using, for example, a knife or a laser.

The material of the protrusion may be appropriately selected within a range that does not impair the object of the present application. As an example, the protrusion may be used by appropriately selecting a metal material that can be molded into a protrusion. In one example, aluminum may be used as the metal. Surface treatment such as polishing may be performed on the metal. The polishing process may be advantageous in terms of minimizing damage to the rubbing cloth during rubbing by lowering the surface roughness of the metal. Examples of the polishing process include anodizing, chemical polishing, electrolytic polishing or buffing. In one example, the metal may be surface treated by anodizing, for example, hard anodizing. Anodizing can function to increase hardness and prevent corrosion of the metal by forming an oxide film, for example, an anodizing film, on the surface of the metal. In the present application, since the protrusions come into direct contact with the rubbing fabric during rubbing, when corrosion occurs in the metal, a problem may occur that may contaminate not only the rubbing fabric but also the substrate to be rubbed. In consideration of this point, it may be advantageous to use a metal protrusion surface-treated by anodizing.

The method of manufacturing the protrusion may be appropriately selected within a range that does not impair the object of the present application. For example, the protrusion may be formed through a known metal forming method capable of forming the shape of the protrusion on the substrate. In one example, the protrusion may be formed by an embossing method. The embossing method is a kind of stamping and fixing, and may be advantageous in that it can locally plastically deform the protrusions without causing a change in the thickness of the material. According to the embossing process, by using a pair of upper and lower dies in which the shape of the desired protrusions are opposite to each other, the shape of the protrusion can be manufactured by imprinting the shape of the protrusion on a substrate made of a metal material.

The area of the cross section of the protrusion may be appropriately selected in consideration of the purpose of the present application. The area of the protrusion may be manufactured to be smaller than the area of the cut. If the area of the protrusion is larger than the area of the cutting unit, rubbing using the protrusion may not be possible because the protrusion is not mounted on the cutting unit. If the area of the protrusion is too small compared to the area of the cut, there is a risk of damage to the rubbing cloth due to the gap between the two parts. In consideration of this point, the area of the protrusion may be 95% to 99% of the area of the cut, for example. When the substrate includes a plurality of cutting portions, the relationship between the individual cutting portions and the areas of the projections applied to the cutting portions may satisfy the above range.

The protrusion may have an upper surface portion and a side portion. The upper surface of the protrusion may be inserted into the cutting portion of the substrate and then exposed to the outside of the substrate. The upper surface portion of the protrusion may have a curved shape, for example, a shape that is convex upward. Through this shape, it may be more advantageous to prevent damage to the rubbing fabric during rubbing treatment. After being inserted into the cutting portion of the substrate, the side portion of the protrusion may exist close to the cut surface (side portion of the cutting portion) of the substrate. That is, the step of inserting the protrusion into the cutting part may be performed so that the side part of the protrusion does not come into contact with the side part of the cutting part.

The step of inserting the projections into the cutting portion may be performed by applying a lower layer having projections to a substrate having the cutting portion. 1 exemplarily shows a lower layer 200 having a protrusion 30. The lower layer may have a bottom portion other than a region having a protrusion. In this case, a lower layer may be applied so that the bottom portion contacts the lower surface of the substrate.

The rubbing treatment of the alignment layer may be performed using a rubbing roll having a rubbing cloth. FIG. 1 exemplarily shows a rubbing roll 40 having a rubbing cloth 50. As shown in FIG. 1, the rubbing roll generally has a cylindrical shape and may have a structure in which a rubbing cloth is wound and attached to a surface thereof. In the above, the rubbing cloth may be usually made of a material such as cotton, rayon or nylon.

The rubbing treatment may be performed by bringing the rubbing cloth into contact with the alignment layer while rotating the rubbing roll having the rubbing cloth. In this process, the contact is performed while moving the rubbing roll and/or the substrate, and thus the contact may be performed while moving the relative position of the substrate and the rubbing roll. As an example, a substrate including an alignment layer may be loaded onto a stage, and a rubbing treatment may be performed while moving the stage in a direction of the rubbing roll while the rubbing roll rotates.

As an example, the rubbing cloth may have a shape curved in one direction. In this case, the rubbing process may be performed while the rotation direction of the rubbing roll is in a direction opposite to the bending direction of the rubbing cloth. In the above, the bending direction and the rotation direction are based on the rubbing roll 40. For example, in the case of the rubbing roll of the type shown in FIG. 1, the rotation direction is counterclockwise, and when the rubbing roll 40 is referenced, the bending direction of the rubbing cloth 50 is clockwise. The rubbing treatment may be performed such that the surface of the rubbing cloth in a curved direction contacts the alignment layer or the protrusion.

According to the present application, the rubbing treatment may be performed so that the rubbing cloth does not contact the cutting part. Specifically, it may be performed so as not to touch the edge portion of the substrate generated by cutting. This is possible by the protrusion inserted in the cutting part, and the rubbing cloth can touch the protrusion instead of touching the cutting part. Accordingly, damage to the rubbing fabric may be prevented, and since the rubbing fabric does not directly contact the cutting portion, accumulation of alignment layer debris on the rubbing fabric may be reduced.

The rubbing process may be performed to satisfy the relationship of Equation 1. The thickness (A) of the substrate, the height of the protrusion (B), and the thickness of the rubbing cloth (C) may be selected within a range satisfying the relationship of Equation 1 above.

As an example, the thickness A of the substrate may be in the range of 50 μm to 300 μm. When the thickness A of the substrate is within the above range, it may be advantageous in that a roll-to-roll process is possible.

The height (B) of the protrusion may be appropriately adjusted in consideration of the purpose of the present application. If the height of the protrusion is too low, the rubbing cloth may come into contact with the cutting part and damage to the rubbing cloth may occur. If the height of the protrusion is too high, damage may accumulate in the rubbing cloth, and the rubbing cloth at the part that contacts the protrusion may become higher than that of other parts, and the rubbing strength may be weakened. In consideration of this point, the height B of the protrusion may be, for example, in the range of 50 μm to 2300 μm.

As an example, the thickness (C) of the rubbing cloth may be in the range of 1 mm to 2 mm. When the thickness of the rubbing cloth is within the above range, it may be advantageous in terms of appropriately performing the rubbing process.

The rubbing treatment may be performed such that the rubbing intensity RS determined by Equation 2 below is in the range of 3 to 250. FIG. 2 is a diagram for explaining the intensity of rubbing, and the alignment layer 20 is shown in the configuration of the substrate. In FIG. 2, a configuration including the rubbing roll 40 and the rubbing cloth 50 is illustrated as a rubbing drum 300.

[Equation 2]

RS = 2×N×M×π×n×r/(v-1)

In Equation 2, RS is the rubbing strength during rubbing treatment, N is the number of rubbing, M is the rubbing depth (unit: mm), r is the radius of the rubbing roll (unit: mm), and n is the rotation speed of the rubbing roll. (Unit: rpm), and v is the relative moving speed of the substrate to the rubbing roll (unit: mm/sec).

The number of rubbings (N), the rubbing depth (M), the radius of the rubbing roll (r), the rotational speed of the rubbing roll (n), and the relative movement speed of the substrate with respect to the rubbing roll (v) represent the rubbing strength of Equation 2, respectively. It can be selected within a satisfactory range.

As an example, the number of rubbing (N) is a number indicating how many times the rubbing roll has moved the surface of the substrate, usually 1 to 10, 1 to 9, 1 to 8, 1 to 7, 1 to 6, 1 to 5, It is in the range of 1 to 4, 1 to 3, or 1 to 2.

As an example, the rubbing depth (M) (unit: mm) may be about 0 mm to 2 mm. In one example, the rubbing depth may be about 0.005 mm or more, or about 1 mm or less.

As an example, the range of the radius (r) of the rubbing roll may also be a conventional range, for example, about 50 mm to 300 mm, about 50 mm to 250 mm, about 50 mm to 200 mm, about 50 mm to It may range from 150 mm or about 50 mm to 100 mm.

In Equation 1, the rotation speed (n) of the rubbing roll is usually in the range of 500 to 2000 rpm, and the relative movement speed (v) of the substrate with respect to the rubbing roll may be in the range of about 500 to 2000 mm/sec. .

The manufacturing method of the present application may further include a process of removing the protrusion from the substrate after performing the rubbing treatment.

In addition to the electrode film and the alignment layer, the substrate may include all known layers or structures necessary for driving and configuring an optical device. Examples of such layers or configurations include spacers. On the substrate, a function of maintaining an interval between two substrates may be performed.

The present application also relates to a method of manufacturing an optical device. As the method for manufacturing the optical device, the method for manufacturing the oriented substrate can be used.

The manufacturing method of the optical device of the present application includes forming a light modulation layer between the first oriented substrate and the second oriented substrate, and at least one of the first oriented substrate and the second oriented substrate is added to the manufacturing method. Can be manufactured according to. As an example, both the first and second oriented substrates may be manufactured according to the manufacturing method.

The first alignment substrate may include a first electrode film and a first alignment layer on the first electrode film. The second alignment substrate may include a second electrode film and a second alignment layer on the second electrode film.

The manufacturing method may include forming an optical modulation layer including an optical modulation material between the first alignment layer of the first substrate and the second alignment layer of the second substrate. Accordingly, the optical device manufactured by the above manufacturing method may have a structure including a first electrode film, a first alignment layer, a light modulation layer, a second alignment layer, and a second electrode film in sequence.

The light modulation layer may include a light modulation material. The method of forming the light modulation layer is not particularly limited, and various known methods may be applied.

In an example, when a so-called doting process is applied, the manufacturing method includes doting a light modulating material on an alignment layer of one of the first and second oriented substrates and the other substrate with the light modulating material. It may further include the step of applying pressure in a state facing the doted alignment layer so that the doted light modulation material fills the gap between the alignment layers of the substrate.

The above process may be performed, for example, according to a general doting process, and the specific process is not particularly limited.

Of course, in addition to the above-mentioned doting process, various known methods may be used as a method of forming a light modulation layer. As a method other than the doting process, for example, a process of injecting a light modulating material after bonding the first substrate and the second substrate may be exemplified.

The light modulation layer may include a liquid crystal compound as a light modulation material. Materials, such as the liquid crystal compound, are also selected from known suitable materials as needed without any particular limitation. In one example, as the liquid crystal compound, a nematic liquid crystal or a smectic liquid crystal may be used.

If necessary, the light modulating material may further include a dichroic dye. For example, the dichroic dye can be classified into two types. A dye that absorbs polarization in the long axis direction of the molecule as a molecule that absorbs more light in a specific direction than in other directions is a positive dichroic dye or p A dye absorbing light in a vertical direction may mean a negative dichroic dye or an n-type dye. In general, such a dye may have an absorption spectrum in a narrow region around a wavelength that causes maximum absorption. In addition, dyes used in guest host LCD displays include chemical/optical stability, color and absorption spectrum width, dichroic ratio, pigment order, solubility in host, degree of nonionization, quenching ( extinction) coefficient, purity, and high specific resistance. Unless otherwise specified, the dichroic dye is assumed to be a positive dye.

In the present specification, the term ``dye'' may refer to a material capable of intensively absorbing and/or modifying light in at least a part or the entire range in a visible light region, for example, 400 nm to 700 nm wavelength range, The term "dichroic dye" may mean a material capable of dichroic absorption of light in at least a part or the entire range of the visible light region.

As the dichroic dye, for example, a known dye known to have a property that can be aligned according to the alignment state of the liquid crystal may be selected and used. As a dichroic dye, black dye can be used, for example. Such dyes are known as, for example, azo dyes or anthraquinone dyes, but are not limited thereto.

The dichroic ratio of the dichroic dye may be appropriately selected in consideration of the purpose of the present application. For example, the dichroic dye may have a dichroic ratio of 5 to 20 or less. In the present specification, the term "dicolor ratio" means, for example, in the case of a p-type dye, a value obtained by dividing the absorption of polarized light parallel to the long axis direction of the dye by the absorption of polarized light parallel to the direction perpendicular to the long axis direction. I can. The anisotropic dye may have the dichroic ratio in at least some wavelengths or at any one wavelength within a wavelength range of a visible light region, for example, within a wavelength range of about 380 nm to 700 nm or about 400 nm to 700 nm.

When the light modulating material includes both a liquid crystal compound and a dichroic dye, the light modulating material may function as a guest-host type light modulating material. That is, in the guest-host type light modulation material, dichroic dyes are arranged together according to the arrangement of liquid crystal compounds, so that light parallel to the alignment direction of the dye is absorbed and light perpendicular to the dye is transmitted, thereby exhibiting an anisotropic light absorption effect. . In addition, the content of the anisotropic dye of the light modulating material may be appropriately selected in consideration of the purpose of the present application. For example, the content of the anisotropic dye in the light modulating material may be 0.1% by weight or more to 10% by weight or less.

The driving mode of the optical device using the liquid crystal is not particularly limited, and for example, the DS (Dynamic Scattering) mode, the ECB (Electrically Controllable Birefringence) mode, the IPS (In-Plane Switching) mode, the FFS (Fringe-Field Wwitching) mode , OCB (Optially Compensated Bend) mode, VA (Vertical Alignment) mode, MVA (Multi-domain Vertical Alignment) mode, PVA (Patterned Vertical Alignment) mode, HAN (Hybrid Aligned Nematic) mode, TN (Twisted Nematic) mode, STN (Super Twisted Nematic) mode and the like can be illustrated.

The present application provides a method of manufacturing an oriented substrate with improved rubbing process. In this application, since damage to the rubbing cloth can be prevented, the replacement cycle of the rubbing cloth is lengthened, the outer part and the electrode part can be cut at the same time, reducing the process time, and the problem that the rubbing line is recognized when voltage is applied does not occur. As a result, optical properties can be improved, and a method for manufacturing an oriented substrate which is advantageous also for manufacturing a free-shaped optical device can be provided.

1 exemplarily shows a structure in which a protrusion is inserted into a cutting portion.
2 is a diagram for explaining the rubbing intensity.
3 exemplarily shows a structure in which a protrusion is inserted into the cutting part of Example 1.
4 exemplarily shows a structure in which a protrusion is not inserted into the cutting portion of Comparative Example 1.
5 is a result of observation of rubbing damage in Examples 1 to 3.
6 is a result of observation of rubbing damage in Comparative Examples 1 to 3.
7 is a result of observation of rubbing damage in Examples 4 to 6.
8 is a result of observation of rubbing damage in Comparative Examples 4 to 6.
Fig. 9 is a schematic diagram of square and free-form rubbing.
10 is an observation result of rubbing damage of Examples 7 to 8 and Comparative Examples 7 to 8.

Hereinafter, the present application will be specifically described through examples according to the present application and comparative examples not according to the present application, but the scope of the present application is not limited by the examples presented below.

Example One

A substrate in which an ITO (Indium Tin Oxide) electrode layer and a polyimide vertical alignment layer (Nissan Corporation, SE-5661) were sequentially formed on a PC (polycarbonate polymer) film substrate having a thickness of 100 μm was prepared. The thickness (A) of the substrate is about 100 μm, and the area is 200 mm wide by 150 mm long. Using a wooden knife for the substrate, the electrode portion was cut in the shape shown in Fig. 4(a). One cutting part has an area of 10mm in width and 15mm in length, and the spacing of the cut part is 50mm.

After forming a protrusion (height (B) 300 μm, width 9.5 mm, length 14.5 mm, spacing 50 mm) in the shape shown in FIG. 4(b) by an embossing method on an aluminum substrate (AL6061), surface treatment with hard anodizing, and the protrusion A lower layer having a was prepared.

Next, a protrusion was inserted into the cutting portion of the substrate. Since the area of the cutting part is larger than the area of the protrusion, there is a little gap, so this part was aligned and physically inserted. 4(a) and 4(b) exemplarily show a structure in which a protrusion is inserted into the cutting part, respectively.

The alignment layer was rubbed while the protrusion was inserted into the cutting portion of the substrate.

The rubbing treatment was performed using a rubbing roll formed with a rubbing cloth (nylon material) having a thickness (C) of 1.5 mm. The rubbing treatment was performed so that the rubbing intensity was 50 as the RS value while moving the substrate to the lower portion of the rubbing drum while rotating the rubbing roll. Rubbing was repeated 30 times to prepare a first oriented substrate.

A second oriented substrate was prepared in the same manner as the method of manufacturing the first oriented substrate. At this time, after the rubbing process was completed, the lower layer having the protrusion was removed.

The end of the first oriented substrate is coated with an adhesive that is usually used for manufacturing a liquid crystal cell, and a light modulating material (HCCH's HNG730200 (ne: 1.551, no: 1.476, ε∥: 9.6, ε⊥: 9.6, TNI: 100°C, Δn: 0.075, Δε: -5.7) by dotting a mixture of liquid crystal and anisotropic dye (BASF, X12) and then bonding the second oriented substrate using a vacuum bonding machine, An optical device was manufactured by allowing the dotting light modulation material to be evenly spread between the two substrates.

Example 2

A substrate and an optical device were manufactured in the same manner as in Example 1, except that the number of rubbing was performed 60 times.

Example 3

A substrate and an optical device were manufactured in the same manner as in Example 1, except that the number of rubbing was performed 90 times.

Comparative example One

A substrate and an optical device were manufactured in the same manner as in Example 1, except that a lower layer having a protrusion was not applied in the manufacture of the first oriented substrate and the second oriented substrate. 4(a) and 4(b) exemplarily show a structure in which a protrusion is not inserted into the cutting part, respectively.

Comparative example 2

A substrate and an optical device were manufactured in the same manner as in Comparative Example 1, except that the number of rubbing was performed 60 times.

Comparative example 3

A substrate and an optical device were manufactured in the same manner as in Comparative Example 1, except that the number of rubbing was performed 90 times.

Evaluation example One. Loving Process improvement evaluation

An absorption type linear polarizing plate was laminated to one side of the optical devices manufactured in Examples 1 to 3 and Comparative Examples 1 to 3, respectively, and when voltage was applied to the optical device, it was evaluated whether rubbing step damage was observed in the intermediate gray scale process. The rubbing step damage can be evaluated according to whether a rubbing streak is observed in the middle gradation process. In the above, it was laminated so that the rubbing direction of the optical device and the absorption axis of the absorption type linear polarizing plate were perpendicular. The voltage applied to the optical device in the above is 18 V.

5 is a result of observation of rubbing damage of Examples 1 to 3, and FIG. 6 is a result of observation of rubbing damage of Comparative Examples 1 to 3. As a result of the experiment, in the case of Comparative Examples 1 to 3 without protrusions, rubbing lines were observed during gradation when voltage was applied. This is because the rubbing cloth is damaged by the cutting part and the rubbing strength changes, so the response speed changes. On the other hand, in Examples 1 to 3, there was no damage to the rubbing fabric by the protrusion, so that the rubbing line was not observed even in the gradation process.

Example 4

In Example 1, a substrate and an optical device were manufactured in the same manner as in Example 1, except that a PC film having a thickness of 100 μm was used as it was and the number of rubbing was performed 100 times.

Example 5

In Example 1, instead of the PC film, a substrate and an optical device were manufactured in the same manner as in Example 1, except that a PET (polyethylene terephthalate) film having a thickness of 188 μm was used and the number of rubbing was performed 100 times. At this time, the height of the protrusion was changed to 400 μm.

Example 6

In Example 1, a substrate and an optical device were manufactured in the same manner as in Example 1, except that a COP (Cyclo-olefin Polymer) film having a thickness of 50 μm was used, and the number of rubbing was performed 100 times. At this time, the height of the protrusion was changed to 250 μm.

Comparative example 4

A substrate and an optical device were manufactured in the same manner as in Example 4, except that a lower layer having a protrusion was not applied in the manufacture of the first oriented substrate and the second oriented substrate.

Comparative example 5

A substrate and an optical device were manufactured in the same manner as in Example 5, except that a lower layer having a protrusion was not applied in the manufacture of the first oriented substrate and the second oriented substrate.

Comparative example 6

A substrate and an optical device were manufactured in the same manner as in Example 6, except that a lower layer having a protrusion was not applied in the manufacture of the first oriented substrate and the second oriented substrate.

Evaluation example 2. Loving Process improvement evaluation

It was evaluated whether or not spots were observed when voltage was applied to the optical devices manufactured in Examples 4 to 6 and Comparative Examples 4 to 6, respectively. The voltage applied to the optical device in the above is 18 V.

7 is an observation result of Examples 4 to 6, and FIG. 8 is an observation result of Comparative Examples 4 to 6. As a result of the experiment, in Comparative Examples 4 to 6, in which the projections were not applied to the cutting portion, damage to the rubbing cloth occurred, and stains were observed with the naked eye during cell production. From this, it can be seen that even if the type of the base film is different, damage to the rubbing fabric remains in the absence of projections. On the other hand, in Examples 4 to 6 in which the protrusions were inserted into the cutting part, the damage to the rubbing fabric could be minimized regardless of the type of the base film, so that no stains observed with the naked eye were confirmed.

Example 7

When cutting the substrate, a substrate and an optical device were manufactured in the same manner as in Example 1, except that the cross section of the cut portion was made to be a square (width 200 mm, length 200 mm) shown on the left side of Fig. 9. At this time, the height of the protrusions (B) is 300 μm, the width is 199.5 μm, and the length is 199.5 μm, and the thick solid line in Fig. 9 denotes the step 70 of the cutting portion.

Example 8

The same as in Example 1, except that when cutting the substrate, the cross-section of the cut portion is in a free shape shown on the right side of FIG. 9 (the length of the two long sides is 200 mm, and the length of the four short sides is 100 mm). Substrates and optical devices were prepared.

In this case, the protrusion has the same shape as the free shape, but the height of the protrusion is 300 μm, the length of the two long sides is 199.5 μm, and the length of the four short sides of the protrusion is 99.5 μm. In FIG. 9, the thick solid line 70 means a step difference of the cutting part.

Comparative example 7

In the manufacture of the first substrate and the second substrate, a substrate and an optical device were manufactured in the same manner as in Example 7, except that the protrusion was not inserted into the cutting portion.

Comparative example 8

In the manufacture of the first substrate and the second substrate, a substrate and an optical device were manufactured in the same manner as in Example 8, except that the protrusion was not inserted into the cutting portion.

Evaluation example 3. Loving Process improvement evaluation

It was evaluated whether or not stains were observed when voltage was applied to the optical devices manufactured in Examples 7 to 8 and Comparative Examples 7 to 8, respectively. The voltage applied to the optical device in the above is 18 V.

10 is an observation result of Examples 7 to 8 and Comparative Examples 7 to 8. As a result of the experiment, in the case of a substrate cut into a square, as in Comparative Example 7, even if the rubbing fabric was damaged by not applying the projections, the number of times the rubbing fabric touched the step portion was the same (2 times), so that a defect in which the driving speed was different did not occur. Did. On the other hand, in the case of the substrate cut in a free shape as in Comparative Example 8, the number of times the rubbing cloth touches the stepped portion in the plane is different (two and four times, respectively), so the degree of damage to the rubbing cloth varies, and the driving speed accordingly There was a defect in which stains were observed due to the difference in On the other hand, in Examples 7 to 8 in which the protrusion was applied, regardless of the cutting shape of the cutting portion of the substrate, damage to the rubbing fabric could be minimized, and thus no stains observed with the naked eye were confirmed. From this, it can be seen that the application of the protrusion is necessary for rubbing in the free shape.

Reference Numerals 100: substrate 200: lower layer 300: rubbing drum 400: stage 10: electrode film 20: alignment film 30: protrusion 40: rubbing roll 50: rubbing cloth 60: cutting portion 70: step of cutting portion M: rubbing depth: r: rubbing roll Radius, n: rotation speed of the rubbing roll, v: relative movement speed of the substrate with respect to the rubbing roll

Claims (21)

Inserting a protrusion into the cutting portion of the substrate including the electrode film and the alignment layer, and rubbing the alignment layer using a rubbing roll having a rubbing cloth, and the rubbing treatment is performed to satisfy the relationship of Equation 1 below. And, the rubbing treatment is a method of manufacturing an oriented substrate performed so that the rubbing intensity (RS) determined by the following Equation 2 is in the range of 3 to 250:
[Equation 1]
A <B <(C+A)
In Equation 1, A is the thickness of the substrate, B is the height of the protrusion, and C is the thickness of the rubbing cloth.
[Equation 2]
RS = 2×N×M×π×n×r/(v-1)
In Equation 2, RS is the rubbing strength during rubbing treatment, N is the number of rubbing, M is the rubbing depth (unit: mm), r is the radius of the rubbing roll (unit: mm), and n is the rotation speed of the rubbing roll. (Unit: rpm), and v is the relative moving speed of the substrate to the rubbing roll (unit: mm/sec). The method of claim 1, wherein the electrode film includes a base film and a transparent conductive layer on the base film. The method of claim 1, wherein the alignment layer is a vertical alignment layer or a horizontal alignment layer. The method of claim 1, wherein the alignment layer is a polyimide compound, a poly(vinyl alcohol) compound, a poly(amic acid) compound, a polystylene compound, a polyamide compound And at least one selected from the group consisting of polyoxyethylene compounds. The method of claim 1, wherein the cutting portion is present in an inner region of the substrate. The method of claim 1, wherein the cutting portion of the substrate is formed by cutting performed in the thickness direction of the substrate using a knife or a laser. The method of claim 1, wherein the protrusion has an upper surface portion convex upward. The method of manufacturing an oriented substrate according to claim 1, wherein the protrusion is inserted into the cutting part so that the side part of the protrusion does not come into contact with the side part of the cutting part. The method of claim 1, wherein inserting the projections into the cutting portion is performed by applying a lower layer having projections to the substrate having the cutting portion. The method of manufacturing an oriented substrate according to claim 9, wherein the lower layer has a bottom portion other than a region having a protrusion, and a lower layer is applied so that the bottom portion contacts the lower surface of the substrate. The method of claim 1, wherein the protrusion comprises a metal. The method of claim 11, wherein the metal is a metal surface-treated by anodizing. The method of claim 1, wherein the rubbing treatment is performed while rotating the rubbing roll having the rubbing cloth while bringing the rubbing cloth into contact with the alignment layer. The method of claim 13, wherein the rubbing treatment is performed so that the rubbing cloth does not contact the cutting portion. The method of claim 1, wherein the thickness (A) of the substrate is in the range of 50 μm to 300 μm. The method of claim 1, wherein the height (B) of the protrusion is within the range of 50 μm to 2300 μm. The method of claim 1, wherein the thickness (C) of the rubbing cloth is in the range of 1 mm to 2 mm. delete A method of manufacturing an optical device comprising the step of forming a light modulation layer between a first oriented substrate and a second oriented substrate, wherein at least one of the first oriented substrate and the second oriented substrate is applied to the manufacturing method of claim 1. The manufacturing method of the optical device manufactured according to this. The method of manufacturing an optical device according to claim 19, wherein the light modulation layer comprises a liquid crystal compound. 21. The method of claim 20, wherein the light modulation layer further comprises a dichroic dye.

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