WO2013151136A1 - Infrared-shielding film and infrared-shielding element - Google Patents

Description

Infrared shielding film and infrared shielding body

The present invention relates to an infrared shielding film and an infrared shielding body.

In recent years, many window films have been used that are bonded to the windows of buildings and automobiles. One of them is a film that has the function of suppressing the intrusion of infrared rays and preventing the temperature inside the building from rising excessively, reducing the use of cooling and achieving energy saving.

As a method of cutting infrared rays, it has both functions of an infrared absorption type film in which an infrared absorption layer containing an infrared absorber is applied to the film, and an infrared reflection type film in which an infrared reflection layer is applied to the film. Type film is on the market. An example of such a film is one in which metal films are formed on both sides of the film by sputtering or vapor deposition. Such a film does not allow infrared rays to enter the room during the summer, and reflects the infrared rays emitted from the room to the room indoors during the winter, thereby exhibiting a heat shielding function and also has an efficient heat insulation function. Energy saving can be realized both in summer and winter.

Infrared absorption type film converts light energy into heat energy, so the temperature of the attached glass is likely to rise, and the risk of thermal cracking increases, but the infrared reflection type film has a lower risk and a wider application range.

The infrared reflection type film has a technique of laminating dielectric layer films, and a film in which layers having different refractive indexes are alternately laminated by a coating method in which a coating solution is coated on a substrate and laminated (for example, JP-A-8-110401). JP, 2007-33296, A), a film in which a laminated thin film containing metallic silver having a three-layer structure of tungsten oxide / silver / tungsten oxide having a specific thickness is laminated on the surface of a polyester film (for example, US Pat. No. 4 , 368,945)).

In Japanese Patent Application Laid-Open Nos. 2011-252213 and 2011-253094, flat metal particles are coated on a substrate and arranged in a plane to form a metal-based infrared reflection layer having high electromagnetic wave permeability. Techniques to do this are disclosed.

However, the infrared reflection type films described in the above-mentioned JP-A-8-110401, JP-A-2007-33296 and US Pat. No. 4,368,945 have the number of laminated layers in order to increase the infrared reflectance. There is a problem that the transparency of the film decreases due to the increase in the number of layer interfaces.

Further, in the techniques described in JP2011-252213A and JP2011-253094A, when the infrared rays are reflected by the plate-like metal particles simultaneously with the reflection of the infrared rays, the infrared reflectance is increased. The heat generated by absorption increases, and the risk of thermal cracking increases. Furthermore, the oxidation of the metal particles is accelerated by the heat generation of the film, and as a result, the color of the film changes over time.

On the other hand, the general construction method of window film is that after spraying water on the glass surface to which the film is attached and the adhesive surface of the film, the film and glass are bonded together using a spatula or the like. It pushes out moisture between the surfaces. Therefore, the heat-insulating and heat-insulating film having the metal layers on both surfaces of the base material, such as the window film, has two or more metal films, so that the drying of moisture is very slow and the load for draining water during construction increases. There was an inconvenience.

Furthermore, even after the process of extruding moisture, moisture always remains, and sufficient adhesive strength is unlikely to develop until the water dries. In particular, when a thick base material is used, drying of moisture, that is, so-called drainage is slow, and the end of the film may be peeled off from the glass surface. In particular, because of its nature, heat insulating films are often used in cold regions, and drying is slower in winter in cold regions, so the possibility of film peeling is further increased. Therefore, there has been a demand for a film that exhibits good adhesiveness when attached to a glass surface or the like.

Therefore, an object of the present invention is to provide an infrared shielding film excellent in transparency and capable of suppressing discoloration over time, and an infrared shielding body including the infrared shielding film.

Another object of the present invention is to provide an infrared shielding film having good adhesion to a sticking object such as a glass surface and having an excellent heat shielding function and heat insulating function, and an infrared shielding provided with the infrared shielding film. To provide a body.

The present inventors have intensively studied in view of the above problems. As a result, it has been surprisingly found that the above-mentioned problems are solved by an infrared shielding film having a dielectric multilayer film composed of a high refractive index layer and a low refractive index layer and a layer containing flat metal particles. The present invention has been completed.

The above object of the present invention is achieved by the following configuration.

That is, the infrared shielding film of the present invention has a substrate, a dielectric multilayer film composed of a high refractive index layer and a low refractive index layer, and a layer containing flat metal particles.

In the infrared shielding body of the present invention, the above infrared shielding film is provided on at least one surface of the substrate.

It is the schematic perspective view which showed an example of the shape of a flat metal particle, Comprising: It is a figure which shows the substantially hexagonal flat metal particle. It is the schematic perspective view which showed an example of the shape of a flat metal particle, Comprising: It is a figure which shows the substantially disk-shaped flat metal particle. It is the schematic sectional drawing which showed the presence state of the layer containing the flat metal particle which concerns on this invention, Comprising: It is a figure which shows an ideal presence state. It is a schematic sectional drawing which showed the existence state of the layer containing the flat metal particle which concerns on this invention, Comprising: It is a figure explaining the angle ((theta)) which the plane of a base material and the plane of a flat metal particle make. It is a schematic sectional drawing which showed the existence state of the layer containing the flat metal particle which concerns on this invention, Comprising: It is a figure which shows the existing area in the depth direction of the infrared shielding film of the layer containing a flat metal particle. It is a cross-sectional schematic diagram which shows the laminated constitution (internal bonding structure 1) of the infrared shielding film for internal bonding produced in the Example. It is a cross-sectional schematic diagram which shows the layer structure (configuration 2 for internal bonding) of the infrared shielding film for internal bonding produced in the Example. It is a cross-sectional schematic diagram which shows the layer structure (Structure 3 for external pasting) of the infrared shielding film for external sticking produced in the Example. It is a cross-sectional schematic diagram which shows the layer structure (structure 4 for external bonding) of the infrared shielding film for internal bonding produced in the Example. It is a cross-sectional schematic diagram which shows the layer structure (layer structure 5) of the infrared shielding film for external sticking produced by the comparative example.

The infrared shielding film of the present invention has a substrate, a dielectric multilayer film composed of a high refractive index layer and a low refractive index layer, and a layer containing flat metal particles. The infrared shielding film of the present invention has a dielectric multilayer film, so that when used as a window film, the infrared shielding film reflects a near infrared ray from sunlight and functions as a shielding film by not allowing it to enter a room. The layer containing particles also functions as a heat insulating film by reflecting the mid-infrared rays and far-infrared rays that can be emitted to the outside of the room to the indoor side. As described above, since the infrared shielding film of the present invention further includes a layer containing flat metal particles in addition to the dielectric multilayer film, the infrared reflection film is excellent even if the number of layers of the dielectric multilayer film is small. Ratio (infrared shielding effect) is obtained, and the transparency of the film is improved. Further, since the amount of light entering the layer containing the flat metal particles can be reduced, the amount of heat generated by the layer containing the flat metal particles is reduced, and the discoloration of the film over time is suppressed. Thus, according to the present invention, it is possible to provide an infrared shielding film excellent in transparency and capable of suppressing discoloration over time, and an infrared shielding body including the infrared shielding film.

As the basic optical characteristics of the infrared shielding film of the present invention, the transmittance in the visible light region shown in JIS R3106: 1998 is preferably 40% or more, more preferably 60% or more. Further, the reflectance in the wavelength region of 900 nm to 1400 nm is preferably 50% or more, and more preferably 70% or more. Furthermore, it is preferable that the transmittance in the wavelength region of 900 nm to 1400 nm is 30% or less.

In the infrared shielding film of the present invention, the layer containing the flat metal particles and the dielectric multilayer film are formed via the base material, and the area of the base material is A, and the flat metal particles are used. When the occupied area is B, the area ratio C represented by the following formula 1 is preferably 15% or more and less than 90%. A detailed method for measuring the substrate area A and the occupied area B will be described later.

By adopting the above configuration, the infrared shielding film having such a configuration can also improve the adhesion to an object to be adhered such as a glass surface.

It is difficult for a general window film to obtain a sufficient adhesive force until an object on which the film is adhered, such as a glass surface, and water existing between the films are dried. Therefore, when the window film includes a metal film as in the prior art, water is difficult to dry, and the end of the film may be peeled off from the glass surface.

With respect to this problem, since the dielectric multilayer film and the layer containing the flat metal particles are formed through the base material, the effect that the water is easily dried when the film is pasted using water. Can be expected.

And about the layer containing a flat metal particle, by making the area rate which the said flat metal particle occupies less than 90%, it becomes easy to drain water between a film and a sticking object, As a result, sufficient adhesion It becomes easier to gain power. That is, the adhesion of the film to the object to be applied is greatly improved, and the film can be prevented from peeling off. On the other hand, when the area ratio is 90% or more, drying of water is delayed.

Thus, by making the area ratio of the flat metal particles less than 90%, dehydration can be accelerated and the adhesion of the film can be improved. However, if the area ratio is too small, a sufficient heat shielding effect is obtained. It becomes difficult to obtain a heat insulation effect. Therefore, by setting the area ratio to 15% or more, a sufficient heat shielding effect and heat insulating effect can be obtained by the layer containing the flat metal particles, and not only the adhesion of the infrared shielding film but also the heat shielding effect and The heat insulation effect can be improved. That is, according to the said aspect, the infrared shielding film provided with the infrared shielding film which has favorable adhesiveness with respect to sticking objects, such as a glass surface, and has the outstanding heat-shielding function and heat insulation function, and this infrared shielding film The body can be provided.

In addition, the present inventor has proposed that the infrared shielding film of the present invention can solve the problem that discoloration of the film occurs due to mold fungi resulting from residual water and the product life is shortened. Also found a positive effect. As the configuration of the dielectric multilayer film, as described in detail below, a configuration containing a water-soluble resin is often employed. Thus, when a water-soluble resin is contained in a window film, when the film is used for a long time under a high humidity condition, the film is particularly easily discolored due to the effect of mold.

On the other hand, the infrared shielding film of the present invention uses the bactericidal action by a metal such as silver, so that the dielectric multilayer film is not affected by mold fungus and the effect that the product life is remarkably increased can be obtained. I understood. In order to obtain a higher antifungal effect, it is preferable that the layer containing a metal such as silver, that is, the layer containing flat metal particles is adjacent to the dielectric multilayer film, but the infrared shielding film of the present invention Thus, even if these layers are formed through the substrate, a sufficient antifungal effect can be obtained. By providing the layer containing the flat metal particles in a part of the infrared shielding film, the layer containing the flat metal particles can suppress the growth of mold, and thereby, This is considered to be because the effect of delaying the expansion is obtained.

Hereinafter, the components of the infrared shielding film of the present invention will be described in detail.

[Base material (support)]
The substrate (support) used in the infrared shielding film of the present invention is preferably a film support. The film support may be transparent or opaque, and various resin films can be used. Specific examples include poly (meth) acrylate, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyarylate, polystyrene (PS), aromatic polyamide, polyether ether ketone, polysulfone. And resin films such as polyethersulfone, polyimide, and polyetherimide, and resin films obtained by laminating two or more layers of the above resin films. From the viewpoint of cost and availability, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC) and the like are preferably used.

The thickness of the substrate according to the present invention is preferably 5 to 200 μm, and more preferably 15 to 150 μm. Two or more substrates may be stacked, and in this case, the types of the substrates may be the same or different.

The base material according to the present invention preferably has a visible light region transmittance of 85% or more, more preferably 90% or more, as shown in JIS R3106: 1998. If it is the range of such a transmittance | permeability, it will become advantageous for the transmittance | permeability of the visible region shown by JISR3106: 1998 when it is set as an infrared shielding film to be 40% or more, and is preferable.

The base material according to the present invention can be produced by a conventionally known general method. For example, an unstretched substrate that is substantially amorphous and not oriented can be produced by melting a resin as a material with an extruder, extruding it with an annular die or a T-die, and quenching. In addition, the unstretched base material is subjected to a known method such as uniaxial stretching, tenter-type sequential biaxial stretching, tenter-type simultaneous biaxial stretching, tubular-type simultaneous biaxial stretching, or the flow direction of the base material (vertical axis), or A stretched support can be produced by stretching in the direction perpendicular to the flow direction of the substrate (horizontal axis). The draw ratio in this case can be appropriately selected according to the resin as the raw material of the base material, but is preferably 2 to 10 times in each of the vertical axis direction and the horizontal axis direction.

As described above, the substrate may be an unstretched film or a stretched film, but a stretched film is preferable from the viewpoint of improving the strength and suppressing thermal expansion.

In addition, the base material according to the present invention may be subjected to relaxation treatment or offline heat treatment in terms of dimensional stability. It is preferable that the relaxation treatment is performed in a process from the heat setting in the stretching process of the polyester film to the winding in the transversely stretched tenter or after exiting the tenter. The relaxation treatment is preferably performed at a treatment temperature of 80 to 200 ° C, more preferably 100 to 180 ° C. In addition, the relaxation rate is preferably in the range of 0.1 to 10% in both the longitudinal direction and the width direction, and more preferably, the relaxation rate is 2 to 6%. The relaxed support is subjected to the above-described off-line heat treatment to improve heat resistance and to improve dimensional stability.

In the base material according to the present invention, it is preferable to apply the undercoat layer coating solution inline on one side or both sides in the film forming process. In the present invention, undercoating during the film forming process is referred to as in-line undercoating. Examples of resins used in the undercoat layer coating solution useful in the present invention include polyester resins, acrylic-modified polyester resins, polyurethane resins, acrylic resins, vinyl resins, vinylidene chloride resins, polyethyleneimine vinylidene resins, polyethyleneimine resins, and polyvinyl alcohol resins. , Modified polyvinyl alcohol resin, gelatin and the like can be used, and these can be used alone or in combination of two or more. A conventionally well-known additive can also be added to these undercoat layers. The undercoat layer can be coated by a known method such as roll coating, gravure coating, knife coating, dip coating or spray coating. The coating amount of the undercoat layer is preferably about 0.01 to 2 g / m ² (dry state).

[Layer containing flat metal particles]
The layer containing the flat metal particles according to the present invention is formed on one surface of the substrate. The layer containing the flat metal particles may have a single layer structure or a laminated structure of two or more layers. Moreover, the material of a metal particle may be individual, and may be used in combination of 2 or more types.

The material of the metal particles is not particularly limited, and for example, gold, silver, copper, aluminum, gallium, indium, zinc, rhodium, palladium, iridium, nickel, platinum, manganese, iron, zirconium, molybdenum, chromium, tungsten, tin , Germanium, lead, antimony and the like, which are stable metals at room temperature, or alloys of these metals. Among these, it is preferable to use gold, silver, or copper having high stability. And it is particularly preferable to use silver. That is, the layer containing tabular metal particles preferably contains at least tabular silver particles.

(Plate metal particles)
The flat metal particles are not particularly limited as long as they are particles composed of two main planes, and can be appropriately selected according to the purpose. Examples of the shape when observed from above the main plane include a substantially hexagonal shape (see FIG. 1A), a substantially disk shape (see FIG. 1B), a substantially triangular shape, and the like. Among these, a substantially hexagonal shape and a substantially disk shape are preferable in terms of high visible light transmittance.

The substantially hexagonal shape is not particularly limited as long as it is a substantially hexagonal shape when the flat metal particles are observed from above the main plane with a transmission electron microscope (TEM), and can be appropriately selected according to the purpose. . For example, the hexagonal corners may be sharp or dull, but the corners are preferably dull in that the absorption in the visible light region can be reduced. There is no restriction | limiting in particular as a grade of the dullness of an angle, It can select suitably.

The substantially disk shape is not particularly limited as long as it has no corners when the flat metal particles are observed from above the main plane with a transmission electron microscope (TEM), and can be appropriately selected.

The ratio of the substantially hexagonal or disk-shaped tabular metal particles is preferably 60% by number or more, more preferably 65% by number or more, and even more preferably 70% by number or more with respect to the total number of tabular metal particles. If the ratio of the said flat metal particle is said range, visible light transmittance will improve.

The average particle size of the flat metal particles is not particularly limited and may be appropriately selected. However, it is preferably 70 nm to 500 nm, and more preferably 100 nm to 400 nm. When the average particle diameter is in the above range, sufficient infrared reflectivity is obtained, haze is reduced, and transparency is improved. In addition, the said average particle diameter means the average value of the main plane diameter (maximum length) of 200 tabular grains arbitrarily selected from the image obtained by observing a particle | grain with TEM.

The layer containing tabular metal particles can contain two or more types of tabular metal particles having different average particle diameters. In this case, two or more peaks of the average particle diameter of the tabular metal particles, that is, 2 It may have two average particle sizes.

The coefficient of variation in the particle size distribution of the flat metal particles is preferably 30% or less, more preferably 10% or less. When the coefficient of variation is in the above range, the infrared reflection wavelength region in the layer containing flat metal particles becomes sharper.

Here, the coefficient of variation in the particle size distribution of the flat metal particles is, for example, plotting the distribution range of the particle sizes of the 200 flat metal particles used for the calculation of the average particle diameter, and the standard deviation of the particle size distribution. Is the value (%) divided by the average value (average particle diameter) of the main plane diameter (maximum length) obtained by the above method.

The aspect ratio of the tabular metal particles is not particularly limited and can be appropriately selected according to the purpose.From the viewpoint that the reflectance in the near infrared light region is increased from the long wavelength side of the visible light region, It is preferably 2 or more, more preferably 2 to 30, and still more preferably 4 to 25. When the aspect ratio is in the above range, the infrared reflectance is increased and the haze can be decreased. The aspect ratio means a value (L / d) obtained by dividing the average particle diameter (average equivalent circle diameter) (L) of the flat metal particles by the average particle thickness (d) of the flat metal particles (FIG. 1A). And see FIG. 1B). The average particle thickness corresponds to the distance between the main planes of the flat metal particles, and can be measured by, for example, an atomic force microscope (AFM).

The method for measuring the average particle thickness by the AFM is not particularly limited and can be appropriately selected. For example, a particle dispersion containing tabular metal particles is dropped on a glass substrate and dried to obtain a tabular metal. For example, a method of measuring the thickness of one particle may be used.

The content (attachment amount) of the flat metal particles in the layer containing the flat metal particles is preferably 0.01 to 1 g / m ² (10 to 1000 mg / m ² ), preferably 0.02 to 0.5 g. / M ² (20 to 500 mg / m ² ) is more preferable, and 0.025 to 0.15 g / m ² (25 to 150 mg / m ² ) is particularly preferable.

(Method for producing flat metal particles)
Examples of the method for producing the flat metal particles include liquid phase methods such as a chemical reduction method, a photochemical reduction method, and an electrochemical reduction method. Among these, the chemical reduction method, the photochemical reduction method, and the like are preferable from the viewpoints of shape and size controllability. After synthesis the tabular metal particles hexagonal or triangular shape, for example, nitric acid, sodium sulfite, Br ^-, Cl ^- performing the aging process by etching, or heating by dissolving species which dissolves silver and halogen ions such as Accordingly, the corners of the hexagonal or triangular tabular metal particles may be blunted to obtain substantially hexagonal or discoidal tabular metal particles.

In addition to the above, as a method for producing the flat metal particles, a seed crystal is fixed in advance on the surface of a transparent substrate such as a film or glass, and then metal particles (for example, Ag) are crystal-grown in a flat shape. There may be.

The plate-like metal particles may be further processed to give desired properties. There is no restriction | limiting in particular as such a process, For example, formation of various additives, such as formation of a high refractive index shell layer, a dispersing agent, antioxidant, etc. are mentioned.

The flat metal particles may be coated with a high refractive index material having high transparency in the visible light region in order to further enhance the transparency in the visible light region.

As the high refractive index material is not particularly limited, for _example, TiO _x, BaTiO _3, ZnO, etc. SnO _2, ZrO _2, NbO _x and the like.

There is no restriction | limiting in particular as said coating method, For example, Langmuir, 2000, 16 volumes, p. As reported in 2731-2735, a method of forming a TiO _x layer on the surface of the plate-like metal particles by hydrolyzing tetrabutoxy titanium may be used.

Further, when it is difficult to form a high refractive index shell layer directly on the flat metal particles, after synthesizing the flat metal particles as described above, an SiO ₂ or polymer shell layer is appropriately formed, A metal oxide layer may be formed on this shell layer. When TiO _x is used as a material for the high refractive index shell layer, since TiO _x has photocatalytic activity, there is a concern that the matrix in which the plate-like metal particles are dispersed may be deteriorated. After forming the TiO _x layer on the metal particles, an SiO ₂ layer may be appropriately formed.

The flat metal particles may adsorb an antioxidant such as mercaptotetrazole or ascorbic acid in order to suppress oxidation of a metal such as silver constituting the flat metal particles. Further, for the purpose of preventing oxidation, an oxidation sacrificial layer such as Ni may be formed on the surface of the flat metal particles. Further, for the purpose of suppressing oxygen permeation, it may be covered with a metal oxide film such as SiO ₂ .

For the purpose of imparting dispersibility, the flat metal particles are added with a low molecular weight dispersant containing N element, S element, and P element, such as a quaternary ammonium salt, amines, and a high molecular weight dispersant. May be.

(Plane orientation)
In the layer containing the flat metal particles, it is preferable that the main surfaces of the flat metal particles are oriented in a predetermined range with respect to the surface of the substrate.

The flat metal particles are preferably unevenly distributed substantially horizontally with respect to the substrate plane from the viewpoint of increasing the infrared reflectance.

Such a plane orientation is not particularly limited as long as the main plane of the flat metal particles and the surface of the base material are substantially parallel within a predetermined range. The angle is 0 ° to ± 40 °, more preferably 0 ° to ± 30 °, still more preferably 0 ° to ± 20 °, and particularly preferably 0 ° to ± 5 °. If it is said range, an infrared reflectance will improve.

Here, FIGS. 2A to 2C are schematic cross-sectional views showing the state of the presence of the flat metal particles 1 in the layer 2 containing the flat metal particles in the infrared shielding film of the present invention. FIG. 2A is a view showing an ideal existence state of the flat metal particles 1 in the layer 2 containing the flat metal particles. FIG. 2B is a diagram for explaining an angle (± θ) formed by the plane of the substrate 3 and the main plane of the flat metal particles 1. FIG. 2C shows the existence region in the depth direction of the infrared shielding film of the layer 2 containing flat metal particles.

In FIG. 2B, the angle (± θ) formed by the surface of the substrate 1 and the main plane of the tabular metal particles 3 or an extension line of the main plane corresponds to a predetermined range in the plane orientation. That is, the plane orientation means a state in which the tilt angle (± θ) shown in FIG. 2B is small when the cross section of the infrared shielding film is observed. In particular, FIG. 2A shows the surface of the substrate 1 and the flat metal particles 3. A state in which the angle (θ) formed with the main plane is 0 ° is shown. If the angle of the plane orientation of the main plane of the flat metal particles 3 with respect to the surface of the substrate 1, that is, θ in FIG. 2B is preferably within ± 40 °, more preferably within ± 30 °, the infrared shielding film The reflectance of a predetermined wavelength (for example, from the long wavelength side of the visible light region to the near infrared light region) is improved, and the haze is reduced.

(Evaluation method of plane orientation)
As an evaluation method of whether or not the main plane of the flat metal particles is plane-oriented with respect to the surface of the base material, for example, an appropriate cross section is prepared, and the base material and the flat metal particles in this section are observed. And a method for evaluation. Specifically, a cross-section sample or a cross-section sample of the infrared shielding film is prepared from the infrared shielding film using a razor, a microtome, a focused ion beam (FIB), and the like, and this is used for various microscopes (for example, a scanning type). Examples thereof include a method of evaluating from an image obtained by observation using an electron microscope (SEM), a field emission scanning electron microscope (FE-SEM) or the like.

In the infrared shielding film, when the binder covering the plate-like metal particles swells with water, the sample frozen in liquid nitrogen is cut with a diamond cutter attached to a microtome to obtain a cross-sectional sample or cross-sectional piece. A sample may be made. Moreover, when the binder which coat | covers a flat metal particle in an infrared shielding film does not swell with water, you may produce a cross-section sample or a cross-section slice sample.

The method for observing the cross-section sample or cross-section sample prepared as described above is not particularly limited as long as it can confirm whether the main plane of the plate-like metal particles is plane-oriented with respect to the surface of the base material in the sample. There are, for example, observation methods using SEM, FE-SEM, transmission electron microscope (TEM), optical microscope, and the like. The cross-sectional sample may be observed by FE-SEM, and the cross-sectional slice sample may be observed by TEM. When evaluating by FE-SEM, it is preferable to have a spatial resolution that can clearly determine the shape and tilt angle (± θ in FIG. 2B) of the flat metal particles.

(Existence range of flat metal particles)
In the infrared shielding film of the present invention, as shown in FIG. 2C, the plasmon resonance wavelength of the metal constituting the tabular metal particle 3 in the layer 2 including the tabular metal particles is λ, and the layer 2 including the tabular metal particles When the refractive index of the medium in n is n, the layer 2 containing the flat metal particles is preferably present in the range of (λ / n) / 4 in the depth direction from the horizontal plane of the infrared shielding film. . Within this range, the effect of enhancing the phases of the reflected waves at the air interfaces on the front and back surfaces of the infrared shielding film is increased, and the visible light transmittance and infrared maximum reflectance can be improved.

The plasmon resonance wavelength λ of the metal constituting the tabular metal particle in the layer containing the tabular metal particle according to the present invention is not particularly limited, but is 400 nm to 2,500 nm in terms of imparting infrared reflection performance. In view of reducing haze (scattering property) in the visible light region, 700 nm to 2,500 nm is more preferable.

There is no restriction | limiting in particular as a medium in the layer containing a flat metal particle, For example, polyvinyl acetal resin, polyvinyl alcohol resin, polyvinyl butyral resin, polyacrylate resin, polymethylmethacrylate resin, polycarbonate resin, polyvinyl chloride resin, saturated polyester Resins, polyurethane resins, polymers such as natural polymers such as gelatin and cellulose, and inorganic substances such as silicon dioxide and aluminum oxide.

The refractive index (n) of the medium is preferably 1.4 to 1.7.

(Occupied area and area ratio by flat metal particles)
When the infrared shielding film of the present invention is viewed from above, that is, the planar metal particles occupy the area A of the base material when viewed from the direction in which the layers including the dielectric multilayer film and the planar metal particles are laminated. The total area value, that is, the area ratio C, which is the ratio of the occupied area B by the flat metal particles, is represented by the following formula (1).

In addition, when the infrared shielding film has a plurality of layers containing flat metal particles, the area occupied by the flat metal particles when viewed from the stacking direction is defined as B in a state where these layers are stacked. That is, when the tabular metal particles of one layer and the other layer are completely overlapped, only the area of the larger tabular metal particle is measured, and a part of the particles overlaps Suppose that the area within the outer periphery of the overlapping particles is measured.

The area ratio C is specifically measured and calculated from an SEM image observed at 30,000 times. The procedure will be specifically described below.

First, an SEM image is taken at an arbitrary location on the infrared shielding film. Next, the obtained SEM image is binarized as a black and white image, and the total area of the portions where the flat metal particles are present is obtained as the actually occupied area b. On the other hand, the area of the visual field range of the SEM image is a. Based on the following formula (2), an actual area ratio c is obtained.

The above-described series of procedures is performed at any three locations on the infrared shielding film, and the average value of the obtained values of c is defined as the area ratio C of Equation 1 above. Further, the substrate area A and the occupied area B in the above formula (1) are A: a = B: b in relation to the area a of the visual field range and the actually occupied area b.

In the infrared shielding film of the present invention, the area ratio C is preferably 15% or more, and more preferably 20% or more. When the area ratio C is in the above range, the maximum infrared reflectance is improved, and a heat shielding effect and a heat insulating effect are sufficiently obtained.

The upper limit value of the area ratio C is not particularly limited, but it is preferable that the upper limit value is less than 90%, for example, in applications that require transparency, such as observation deck glass. In applications where electromagnetic wave shielding properties are required, such as automotive glass, the upper limit is preferably 100% or less. Moreover, when the area ratio C is less than 90%, when the infrared shielding film is attached to an object such as glass and installed, water can easily escape and an effect of improving adhesion can be obtained. Furthermore, the infrared shielding film having a layer containing flat metal particles having an area ratio C within the above range can also provide an effective antifungal effect.

That is, in the infrared shielding film of the present invention, the area ratio C is preferably 15% or more and less than 90%. The area ratio C is more preferably 20% or more and 85% or less, and particularly preferably 55% or more and 80% or less. By setting it to 20% or more and 85% or less, a high heat shielding effect and a heat insulating effect can be obtained, and extremely good adhesion can be obtained. Furthermore, by setting it to 55% or more and 80% or less, an extremely good infrared shielding film can be obtained in all of the heat shielding effect, the heat insulating effect, and the adhesion. Moreover, in the said range, an infrared shielding film also has a favorable antifungal effect.

The method for forming a layer containing flat metal particles such that the area ratio C is in the above range in the layer containing flat metal particles will be described in detail below.

(Average distance between flat metal particles)
The average interparticle distance between the flat metal particles adjacent in the horizontal direction in the layer containing the flat metal particles according to the present invention is the average particle diameter of the flat metal particles from the viewpoint of visible light transmittance and maximum infrared reflectance. It is preferable that it is 1/10 or more.

If the average inter-particle distance in the horizontal direction of the flat metal particles is in the above range, the maximum infrared reflectance is improved. The horizontal average interparticle distance is preferably non-uniform (random) from the viewpoint of visible light transmittance. If it is random, absorption of visible light hardly occurs and visible light transmittance is improved.

Here, the average inter-particle distance in the horizontal direction of the flat metal particles means an average value of inter-particle distances between two adjacent particles. The average inter-particle distance is random as follows: “When the two-dimensional autocorrelation of the luminance value when binarizing an SEM image including 100 or more tabular metal particles is taken, Does not have a significant local maximum. "

In the infrared shielding film of the present invention, the flat metal particles are arranged in the form of a layer containing the flat metal particles as shown in FIGS. 2A to 2C.

As shown in FIGS. 2A to 2C, the layer containing flat metal particles may be composed of a single layer or a plurality of layers. When composed of a plurality of layers, it becomes possible to provide shielding performance according to the wavelength band to which heat shielding performance is desired.

(Method for forming layer containing flat metal particles)
There is no restriction | limiting in particular as a formation method of the layer containing the flat metal particle which concerns on this invention, It can form according to a well-known method. For example, it can be suitably formed by a coating method in which a coating solution containing flat metal particles formed by blending the above components is applied. By using the coating method, the area ratio C occupied by the above-described flat metal particles can be easily controlled. Specifically, the coating film is prepared by adding the medium and the plate-like metal particles produced by the method described in the above (Method for producing plate-like metal particles) to an appropriate solvent to apply the coating solution. The area ratio C can be controlled to be in a desired range by adjusting the thickness (film thickness in a dry state) using a wire bar or the like. Moreover, since the angle (the above θ) of the plate-like metal particles with respect to the substrate can be adjusted by adjusting the temperature (drying temperature) for drying after applying the coating liquid, as a result, the area ratio C can be controlled. When the drying temperature is increased, the value of θ is close to 90 °, and the area ratio C occupied by the flat metal particles can be reduced. Further, the area ratio C may be controlled by appropriately adjusting the concentration of the coating liquid and adjusting the amount of the flat metal particles.

More specifically, in order to make the area ratio, which is the ratio of the area occupied by the flat metal particles with respect to the area of the base material, in the preferred range, the drying temperature is 50 to 150 ° C., and the amount of the flat metal particles is 10 to 200 mg / m ² is preferable. The drying temperature is more preferably 60 to 100 ° C., and the weight is more preferably 25 to 150 mg / m ² .

Examples of the coating method include spin coating, dip coating, extrusion coating, bar coating, die coating, and gravure coating.

In addition, a method of planarly aligning the flat metal particles by a method such as an LB film method, a self-assembly method, or spray coating can be used.

As a method for plane-aligning the flat metal particles, a method of aligning the plane using electrostatic interaction is adopted in order to enhance the adsorptivity of the flat metal particles to the base material and the plane orientation. Also good. Specifically, when the surface of the flat metal particle is negatively charged (for example, dispersed in a negatively charged medium such as citric acid), the surface of the substrate is positively charged (for example, amino acid). The substrate surface may be modified with a group or the like, and the surface orientation may be increased electrostatically to achieve surface orientation. In addition, when the surface of the flat metal particles is hydrophilic, a hydrophilic / hydrophobic sea-island structure is formed on the surface of the base material by a block copolymer or a microcontact stamp method, and the hydrophilic / hydrophobic interaction is utilized. You may control a plane orientation and the intergranular distance of a flat metal particle.

In addition, in order to promote plane orientation, after applying a coating solution containing flat metal particles, it may be passed through a pressing roller such as a calender roller or a laminating roller.

The thickness of the layer containing the flat metal particles is not particularly limited, but is preferably 0.1 μm to 10 μm, and more preferably 0.5 to 8 μm.

(Other ingredients)
The layer containing the flat metal particles according to the present invention may contain various additives, for example, a solvent, a binder, a surfactant, an antioxidant, an antisulfurizing agent, a corrosion inhibitor, an infrared absorber, and an ultraviolet ray as necessary. Absorbers, colorants, viscosity modifiers, preservatives, and the like can be included.

[Dielectric multilayer film]
The infrared shielding film of the present invention has a dielectric multilayer film including a high refractive index layer and a low refractive index layer. The dielectric multilayer film may be formed on the same side as the side on which the layer containing the flat metal particles is formed with respect to the base material. It may be formed on the surface opposite to the side on which the layer containing the flat metal particles is formed. That is, the layer containing flat metal particles and the dielectric layer film may be formed on one surface side of the base material, or they may be formed via the base material. As the material for forming the dielectric multilayer film, conventionally known materials can be used, and examples thereof include metal oxide particles, polymers, and combinations thereof.

Examples of the metal oxide particles may include titanium dioxide (TiO ₂ ), zirconium dioxide (ZrO ₂ ), tantalum pentoxide (Ta ₂ O ₅ ), and the like as examples of the high refractive index material. Examples thereof include silicon dioxide (SiO ₂ ) and magnesium fluoride (MgF ₂ ). Examples of the medium refractive index material include aluminum oxide (Al ₂ O ₃ ). These metal oxide particles can be formed by a dry film forming method such as a vapor deposition method or a sputtering method.

The polymer contained in the dielectric multilayer film is not particularly limited as long as it is a polymer capable of forming the dielectric multilayer film.

For example, as the polymer, a polymer described in JP-T-2002-509279 can be used. Specific examples include, for example, polyethylene naphthalate (PEN) and its isomers (eg, 2,6-, 1,4-, 1,5-, 2,7- and 2,3-PEN), polyalkylene terephthalate (Eg, polyethylene terephthalate (PET), polybutylene terephthalate, and poly-1,4-cyclohexanedimethylene terephthalate), polyimide (eg, polyacrylimide), polyetherimide, atactic polystyrene, polycarbonate, polymethacrylate (eg, Polyisobutyl methacrylate, polypropyl methacrylate, polyethyl methacrylate, and polymethyl methacrylate (PMMA)), polyacrylates (eg, polybutyl acrylate, and polymethyl acrylate), cellulose Derivatives (eg, ethylcellulose, acetylcellulose, cellulose propionate, acetylcellulose butyrate, and cellulose nitrate), polyalkylene polymers (eg, polyethylene, polypropylene, polybutylene, polyisobutylene, and poly (4-methyl) pentene), fluorine Chlorinated polymers (eg, perfluoroalkoxy resins, polytetrafluoroethylene, fluorinated ethylene propylene copolymers, polyvinylidene fluoride, and polychlorotrifluoroethylene), chlorinated polymers (eg, polyvinylidene chloride and polyvinyl chloride), polysulfones, Polyether sulfone, polyacrylonitrile, polyamide, silicone resin, epoxy resin, polyvinyl acetate, polyether amide, ionomer resin Elastomers (e.g., polybutadiene, polyisoprene and neoprene), and polyurethanes. Copolymers such as copolymers of PEN [e.g. (a) terephthalic acid or ester thereof, (b) isophthalic acid or ester thereof, (c) phthalic acid or ester thereof, (d) alkane glycol, (e) cycloalkane glycol ( (E.g., cyclohexanedimethanoldiol), (f) alkanedicarboxylic acid, and / or (g) cycloalkanedicarboxylic acid (e.g., cyclohexanedicarboxylic acid) and 2,6-, 1,4-, 1,5-, 2, 7- and / or copolymers with 2,3-naphthalenedicarboxylic acid or esters thereof], copolymers of polyalkylene terephthalates [eg (a) naphthalenedicarboxylic acid or esters thereof, (b) isophthalic acid or esters thereof, ( c) phthalic acid or The ester, (d) alkane glycol, (e) cycloalkane glycol (eg, cyclohexanedimethanol diol), (f) alkane dicarboxylic acid, and / or (g) cycloalkane dicarboxylic acid (eg, cyclohexanedicarboxylic acid); Also suitable are copolymers with terephthalic acid or esters thereof, and styrene copolymers (eg styrene-butadiene copolymers and styrene-acrylonitrile copolymers), 4,4-bisbenzoic acid and ethylene glycol. In addition, each layer may each include a blend of two or more of the above polymers or copolymers (eg, a blend of syndiotactic polystyrene (SPS) and atactic polystyrene).

As described in US Pat. No. 6,049,419, a dielectric multilayer film can be formed by melt extrusion and stretching of the polymer. In the present invention, a preferred combination of polymers forming the high refractive index layer and the low refractive index layer includes PEN / PMMA, PEN / polyvinylidene fluoride, and PEN / PET.

Further, as the polymer, a polymer described in JP 2010-184493 may be used. Specifically, a polyester (hereinafter also referred to as polyester A) and a polyester (hereinafter also referred to as polyester B) containing residues derived from at least three diols of ethylene glycol, spiroglycol and butylene glycol, Can be used. Polyester A is not particularly limited as long as it has a structure obtained by polycondensation of a dicarboxylic acid component and a diol component. For example, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, Examples thereof include poly-1,4-cyclohexanedimethylene terephthalate and polyethylene diphenylate. Polyester A may be a copolymer. Here, the copolyester has a structure obtained by polycondensation using at least three or more dicarboxylic acid components and diol components. Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, Examples thereof include 4′-diphenylsulfone dicarboxylic acid, adipic acid, sebacic acid, dimer acid, cyclohexanedicarboxylic acid and ester-forming derivatives thereof. Examples of the glycol component include ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentadiol, diethylene glycol, polyalkylene glycol, 2,2-bis (4 ′ -Β-hydroxyethoxyphenyl) propane, isosorbate, 1,4-cyclohexanedimethanol, spiroglycol, and ester-forming derivatives thereof. Polyester A is preferably polyethylene terephthalate or polyethylene naphthalate.

The polyester B includes residues derived from at least three kinds of diols, ethylene glycol, spiroglycol and butylene glycol. Typical examples include copolymerized polyesters having a structure obtained by copolymerization using ethylene glycol, spiroglycol and butylene glycol, and polyesters having a structure obtained by polymerization using these three diols. There is polyester obtained by blending. This configuration is preferable because it is easy to form and difficult to delaminate. Moreover, it is preferable that the polyester B is a polyester containing residues derived from at least two dicarboxylic acids of terephthalic acid / cyclohexanedicarboxylic acid. Such polyesters include copolyesters copolymerized with terephthalic acid / cyclohexanedicarboxylic acid, or those obtained by blending polyesters containing terephthalic acid residues and polyesters containing cyclohexanedicarboxylic acid residues. The polyester containing a cyclohexanedicarboxylic acid residue has a large difference between the in-plane average refractive index of the A layer and the in-plane average refractive index of the B layer, and a high reflectance is obtained. Moreover, since the glass transition temperature difference with polyethylene terephthalate or polyethylene naphthalate is small, it is difficult to be overstretched at the time of molding, and it is preferable that delamination is difficult.

In addition, it is also preferable to use a water-soluble polymer as the polymer. That is, the dielectric multilayer film preferably contains a water-soluble polymer. The water-soluble polymer is preferable because it does not use an organic solvent, has a low environmental load, and has high flexibility, so that the durability of the film during bending is improved. Examples of the water-soluble polymer include polyvinyl alcohols, polyvinyl pyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic ester copolymer, Or acrylic resin such as acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene -Styrene acrylic resin such as acrylic acid copolymer or styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-sodium styrenesulfonate copolymer, styrene-2-hydroxyethyl acrylate copolymer Coalescence, styrene-2 -Hydroxyethyl acrylate-potassium styrene sulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer, vinyl acetate -Synthetic water-soluble polymers such as maleic acid ester copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-based copolymers such as vinyl acetate-acrylic acid copolymers and their salts; gelatin, thickened And natural water-soluble polymers such as saccharides. Among these, particularly preferable examples include polyvinyl alcohol, polyvinylpyrrolidones and copolymers containing them, gelatin, thickening polysaccharides (particularly celluloses) from the viewpoint of handling during production and film flexibility. Is mentioned. These water-soluble polymers may be used alone or in combination of two or more.

The polyvinyl alcohol preferably used in the present invention includes modified polyvinyl alcohol in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate. Examples of the modified polyvinyl alcohol include cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, nonion-modified polyvinyl alcohol, and vinyl alcohol polymers.

The polyvinyl alcohol obtained by hydrolyzing vinyl acetate preferably has an average degree of polymerization of 800 or more, and particularly preferably has an average degree of polymerization of 1,000 to 5,000. The degree of saponification is preferably 70 to 100 mol%, particularly preferably 80 to 99.5 mol%.

Examples of the cation-modified polyvinyl alcohol include primary to tertiary amino groups and quaternary ammonium groups in the main chain or side chain of the polyvinyl alcohol as described in, for example, JP-A-61-110483. It is obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a cationic group and vinyl acetate.

Examples of the ethylenically unsaturated monomer having a cationic group include trimethyl- (2-acrylamido-2,2-dimethylethyl) ammonium chloride and trimethyl- (3-acrylamido-3,3-dimethylpropyl) ammonium chloride. N-vinylimidazole, N-vinyl-2-methylimidazole, N- (3-dimethylaminopropyl) methacrylamide, hydroxylethyltrimethylammonium chloride, trimethyl- (2-methacrylamidopropyl) ammonium chloride, N- (1, And 1-dimethyl-3-dimethylaminopropyl) acrylamide. The ratio of the cation-modified group-containing monomer in the cation-modified polyvinyl alcohol is preferably 0.1 to 10 mol%, more preferably 0.2 to 5 mol%, relative to vinyl acetate.

Examples of the anion-modified polyvinyl alcohol include polyvinyl alcohol having an anionic group as described in JP-A-1-206088, JP-A-61-237681 and JP-A-63-307979. Examples thereof include a copolymer of vinyl alcohol and a vinyl compound having a water-soluble group, and a modified polyvinyl alcohol having a water-soluble group as described in JP-A-7-285265.

Nonionic modified polyvinyl alcohol includes, for example, a polyvinyl alcohol derivative in which a polyalkylene oxide group is added to a part of vinyl alcohol as described in JP-A-7-9758, and JP-A-8-25795. Block copolymer of vinyl compound having hydrophobic group and vinyl alcohol as described, silanol modified polyvinyl alcohol having silanol group, reactivity having reactive group such as acetoacetyl group, carbonyl group, carboxyl group Examples thereof include group-modified polyvinyl alcohol. Examples of the vinyl alcohol-based polymer include EXEVAL (registered trademark, manufactured by Kuraray Co., Ltd.) and Nichigo G polymer (trade name, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.). Polyvinyl alcohol can be used in combination of two or more, such as the degree of polymerization and the type of modification.

As the gelatin used in the present invention, in addition to lime-processed gelatin, acid-processed gelatin may be used, and further, a hydrolyzate of gelatin and an enzyme-decomposed product of gelatin can be used.

Examples of the thickening polysaccharide used in the present invention can include, for example, generally known natural simple polysaccharides, natural complex polysaccharides, synthetic simple polysaccharides, and synthetic complex polysaccharides. Details of these polysaccharides Can refer to “Biochemical Encyclopedia (2nd edition), Tokyo Chemical Doujin Publishing”, “Food Industry”, Vol. 31 (1988), p. 21.

The thickening polysaccharide referred to in the present invention is a polymer of saccharides and has many hydrogen bonding groups in the molecule, and the viscosity at low temperature and the viscosity at high temperature due to the difference in hydrogen bonding force between molecules depending on the temperature. It is a polysaccharide with a large difference in characteristics. When metal oxide fine particles are further added, the viscosity is increased due to hydrogen bonding with the metal oxide fine particles at low temperatures. The viscosity increase width is a polysaccharide which, when added, causes the viscosity at 40 ° C. to rise preferably 1.0 mPa · s or more, more preferably 5.0 mPa · s or more, and even more preferably 10.0 mPa · s. -A polysaccharide having a viscosity increasing ability of s or more.

Examples of the thickening polysaccharide applicable to the present invention include β1-4 glucan (eg, carboxymethylcellulose, carboxyethylcellulose, etc.), galactan (eg, agarose, agaropectin, etc.), galactomannoglycan (eg, locust bean gum). , Guaran, etc.), xyloglucan (eg, tamarind gum, etc.), glucomannoglycan (eg, salmon mannan, wood-derived glucomannan, xanthan gum, etc.), galactoglucomannoglycan (eg, softwood-derived glycan), arabino Galactoglycans (for example, soybean-derived glycans, microbial-derived glycans, etc.), glucoraminoglycans (for example, gellan gum), glycosaminoglycans (for example, hyaluronic acid, keratan sulfate, etc.), alginic acid and alginate, cold , .Kappa.-carrageenan, lambda-carrageenan, iota-carrageenan, natural polymer and polysaccharides derived from red algae such as furcellaran. In particular, in the case of containing metal oxide particles as described later, from the viewpoint of not reducing the dispersion stability of the metal oxide fine particles, it is preferable that the structural unit does not have a carboxyl group or a sulfoxyl group. Such polysaccharides include, for example, pentoses such as L-arabitose, D-ribose, 2-deoxyribose, and D-xylose, and hexoses such as D-glucose, D-fructose, D-mannose, and D-galactose only. It is preferable that it is a polysaccharide. Specifically, tamarind seed gum known as xyloglucan whose main chain is glucose and side chain is xylose, guar gum known as galactomannan whose main chain is mannose and side chain is galactose, locust bean gum, Tara gum or arabinogalactan whose main chain is galactose and whose side chain is arabinose can be preferably used.

In the present invention, two or more thickening polysaccharides may be used in combination.

The weight average molecular weight of the water-soluble polymer is preferably 1,000 to 200,000, more preferably 3,000 to 40,000. In addition, in this specification, the value measured on the measurement conditions shown in following Table 1 using a gel permeation chromatography (GPC) is employ | adopted for a weight average molecular weight.

In the present invention, a curing agent may be used to cure the water-soluble polymer.

The curing agent applicable to the present invention is not particularly limited as long as it causes a curing reaction with a water-soluble polymer. However, when the water-soluble polymer is polyvinyl alcohol, boric acid and its salt are preferable. In addition, other known compounds can be used and are generally compounds having groups capable of reacting with water-soluble polymers or compounds that promote the reaction between different groups of water-soluble polymers. It is appropriately selected according to the type of polymer. Specific examples of the curing agent other than boric acid and its salts include, for example, epoxy curing agents (diglycidyl ethyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-diglycidyl cyclohexane). N, N-diglycidyl-4-glycidyloxyaniline, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, etc.), aldehyde curing agents (formaldehyde, glioxal, etc.), active halogen curing agents (2,4-dichloro-4-) Hydroxy-1,3,5-s-triazine, etc.), active vinyl compounds (1,3,5-tris-acryloyl-hexahydro-s-triazine, bisvinylsulfonylmethyl ether, etc.), aluminum alum and the like.

When the water-soluble polymer is gelatin, for example, organic hardeners such as vinylsulfone compounds, urea-formalin condensates, melanin-formalin condensates, epoxy compounds, aziridine compounds, active olefins, isocyanate compounds, etc. Inorganic polyvalent metal salts such as chromium, aluminum and zirconium.

The form of the copolymer when the polymer is a copolymer may be any of a block copolymer, a random copolymer, a graft copolymer, and an alternating copolymer.

A preferred form of the dielectric multilayer film is preferably a polymer because the area can be increased, the cost is low, and the durability of the film at the time of bending and high temperature and high humidity is improved. In addition to the form in which the dielectric multilayer film is composed only of the polymer, the dielectric multilayer film is more preferably in a form containing a polymer and metal oxide particles.

The form containing metal oxide particles in addition to the polymer will be described. It is preferable that the dielectric multilayer film contains metal oxide particles because the refractive index difference between the refractive index layers can be increased and the transparency of the film can be increased by reducing the number of layers. In addition, there is an advantage that stress relaxation works and film properties (flexibility at the time of bending and high temperature and high humidity) are improved. The metal oxide particles may be contained in any of the films constituting the dielectric multilayer film. However, a preferable form is that at least the high refractive index layer includes metal oxide particles, and a more preferable form is a high refractive index. Both the layer and the low refractive index layer are in a form containing metal oxide particles. That is, it is preferable that the high refractive index layer and the low refractive index layer contain metal oxide particles.

Examples of the metal oxide particles include titanium dioxide, zirconium dioxide, tantalum pentoxide, zinc oxide, silicon dioxide (synthetic amorphous silica, colloidal silica, etc.), alumina, colloidal alumina, lead titanate, red lead, yellow lead. , Zinc yellow, chromium oxide, ferric oxide, iron black, copper oxide, magnesium oxide, magnesium hydroxide, magnesium fluoride, strontium titanate, yttrium oxide, niobium oxide, europium oxide, lanthanum oxide, zircon, tin oxide, etc. Can be mentioned.

The metal oxide particles preferably have an average particle size of 100 nm or less, more preferably 4 to 50 nm, and even more preferably 5 to 40 nm. The average particle size of the metal oxide particles is determined by observing the particles themselves or the particles appearing on the cross section or surface of the layer with an electron microscope and measuring the particle size of 1,000 arbitrary particles. Average). Here, the particle diameter of each particle is represented by a diameter assuming a circle equal to the projected area.

The content of the metal oxide particles in each refractive index layer is preferably 20 to 90% by mass and more preferably 40 to 75% by mass with respect to the total mass of the refractive index layer.

As the metal oxide particles, it is preferable to use solid fine particles selected from titanium dioxide, silicon dioxide, and alumina.

In the low refractive index layer, it is preferable to use silicon dioxide (silica) as the metal oxide particles, and it is more preferable to use acidic colloidal silica sol.

(Silicon dioxide)
Preferred examples of silicon dioxide (silica) that can be used in the present invention include silica synthesized by an ordinary wet method, colloidal silica, silica synthesized by a gas phase method, and the like. Examples of the fine particle silica include colloidal silica and fine particle silica synthesized by a gas phase method.

The metal oxide particles are preferably in a state where the fine particle dispersion before mixing with the cationic polymer is dispersed to the primary particles.

For example, in the case of the gas phase method fine particle silica, the average particle size (particle size in the dispersion state before coating) of the metal oxide fine particles dispersed in the primary particle state is 100 nm or less. It is preferably 4 to 50 nm, more preferably 4 to 20 nm.

As the silica synthesized by the vapor phase method in which the average particle diameter of primary particles is 4 to 20 nm, for example, Aerosil manufactured by Nippon Aerosil Co., Ltd. is commercially available. The vapor phase fine particle silica can be dispersed to primary particles relatively easily by being sucked and dispersed in water, for example, by a jet stream inductor mixer manufactured by Mitamura Riken Kogyo Co., Ltd.

As the gas phase method silica currently marketed, various types of Aerosil manufactured by Nippon Aerosil Co., Ltd. are applicable.

The colloidal silica preferably used in the present invention is obtained by heating and aging a silica sol obtained by metathesis with an acid of sodium silicate or the like and passing through an ion exchange resin layer.

The preferable average particle size of colloidal silica is usually 5 to 100 nm, but an average particle size of 7 to 30 nm is more preferable.

Silica and colloidal silica synthesized by a vapor phase method may be those whose surfaces are cation-modified, or those treated with Al, Ca, Mg, Ba, or the like.

As the metal oxide particles contained in the high refractive index layer, TiO ₂ , ZnO, and ZrO ₂ are preferable. From the viewpoint of stability of the metal oxide particle-containing composition described later for forming the high refractive index layer, TiO ₂ is used. ₂ (titanium dioxide sol) is more preferable. Of TiO ₂ , rutile type is more preferable than anatase type because the high refractive index layer and the adjacent layer have high weather resistance due to low catalytic activity, and the refractive index is high.

(titanium dioxide)
Method for Producing Titanium Dioxide Sol The first step in the method for producing rutile-type fine particle titanium dioxide is at least one selected from titanium dioxide hydrate selected from the group consisting of hydroxides of alkali metals and alkaline earth metals. This is a step of treating with a basic compound (step (1)).

Titanium dioxide hydrate can be obtained by hydrolysis of water-soluble titanium compounds such as titanium sulfate and titanium chloride. The method of hydrolysis is not particularly limited, and a known method can be applied. Especially, it is preferable that it was obtained by thermal hydrolysis of titanium sulfate.

The step (1) can be performed, for example, by adding the basic compound to an aqueous suspension of the titanium dioxide hydrate and treating (reacting) it under a predetermined temperature condition for a predetermined time. it can.

The method for preparing the titanium dioxide hydrate as an aqueous suspension is not particularly limited, and can be performed by adding the titanium dioxide hydrate to water and stirring. The concentration of the suspension is not particularly limited. For example, it is preferable that the concentration of TiO ₂ is 30 to 150 g / L in the suspension. By setting it within the above range, the reaction (treatment) can proceed efficiently.

The at least one basic compound selected from the group consisting of alkali metal hydroxides and alkaline earth metal hydroxides used in the step (1) is not particularly limited. Examples include potassium, magnesium hydroxide, calcium hydroxide, and the like. The amount of the basic compound added in the step (1) is preferably 30 to 300 g / L in terms of the basic compound concentration in the reaction (treatment) suspension.

The above step (1) is preferably performed at a reaction (treatment) temperature of 60 to 120 ° C. The reaction (treatment) time varies depending on the reaction (treatment) temperature, but is preferably 2 to 10 hours. The reaction (treatment) is preferably performed by adding an aqueous solution of sodium hydroxide, potassium hydroxide, magnesium hydroxide, or calcium hydroxide to a suspension of titanium dioxide hydrate. After the reaction (treatment), the reaction (treatment) mixture is cooled, neutralized with an inorganic acid such as hydrochloric acid as necessary, and then filtered and washed to obtain titanium dioxide hydrate fine particles.

Further, as the second step (step (2)), the compound obtained in the step (1) may be treated with a carboxyl group-containing compound and an inorganic acid. In the production of rutile titanium dioxide fine particles, the method of treating the compound obtained in the above step (1) with an inorganic acid is a known method, but in addition to the inorganic acid, a carboxyl group-containing compound is used to reduce the particle size. Can be adjusted.

The carboxyl group-containing compound is an organic compound having a —COOH group. The carboxyl group-containing compound is preferably a polycarboxylic acid having 2 or more, more preferably 2 or more and 4 or less carboxyl groups. Since the polycarboxylic acid has a coordination ability to a metal atom, it is presumed that the rutile titanium dioxide fine particles can be suitably obtained by suppressing aggregation between the fine particles by coordination.

The carboxyl group-containing compound is not particularly limited, and examples thereof include dicarboxylic acids such as succinic acid, malonic acid, succinic acid, glutaric acid, adipic acid, propylmalonic acid, and maleic acid; and hydroxy compounds such as malic acid, tartaric acid, and citric acid. Carboxylic acids; aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, hemimellitic acid, trimellitic acid; ethylenediaminetetraacetic acid. Among these, two or more compounds may be used in combination.

Note that all or part of the carboxyl group-containing compound may be a neutralized product of an organic compound having a —COOH group (for example, an organic compound having a —COONa group or the like).

The inorganic acid is not particularly limited, and examples thereof include hydrochloric acid, sulfuric acid, nitric acid and the like. The inorganic acid may be added so that the concentration in the reaction (treatment) solution is 0.5 to 2.5 mol / L, more preferably 0.8 to 1.4 mol / L.

The step (2) is preferably performed by suspending the compound obtained in the step (1) in pure water and heating it with stirring as necessary. Although the carboxyl group-containing compound and the inorganic acid may be added simultaneously or sequentially, it is preferable to add them sequentially. The addition may be an addition of an inorganic acid after the addition of the carboxyl group-containing compound or an addition of the carboxyl group-containing compound after the addition of the inorganic acid.

For example, a carboxyl group-containing compound is added to the suspension of the compound obtained by the above step (1), heating is started, and the liquid temperature is preferably 60 ° C. or higher, more preferably 90 ° C. or higher. A method in which an inorganic acid is added and stirring is performed for 15 minutes to 5 hours, more preferably 2 to 3 hours while maintaining the liquid temperature (Method 1); Suspension of the compound obtained by the above step (1) The inside is heated, and when the liquid temperature is preferably 60 ° C. or higher, more preferably 90 ° C. or higher, an inorganic acid is added, and a carboxyl group-containing compound is added 10 to 15 minutes after the inorganic acid is added. A method (method 2) of stirring for 15 minutes to 5 hours, more preferably 2 to 3 hours, while maintaining, can be mentioned. By carrying out these methods, a suitable fine particle rutile type titanium dioxide can be obtained.

When the step (2) is carried out by the method 1, the carboxyl group-containing compound is preferably used in an amount of 0.25 to 1.5 mol% with respect to 100 mol% of TiO ₂ , and 0.4 to 0 More preferably, it is used in a proportion of 8 mol%. If the addition amount of the carboxyl group-containing compound is within the above range, particles having the target particle size can be obtained, and the rutileization of the particles can proceed more efficiently.

When the step (2) is performed by the method 2, the carboxyl group-containing compound is preferably used in an amount of 1.6 to 4.0 mol% with respect to 100 mol% of TiO ₂ , and is preferably 2.0 to 2 More preferably, it is used in a proportion of 4 mol%.

If the addition amount of the carboxyl group-containing compound is in the above range, particles having the target particle size can be obtained, and the rutileization of the particles can proceed more efficiently and is economically advantageous. Further, if the carboxyl group-containing compound is added 10 to 15 minutes after the addition of the inorganic acid, the rutileization of the particles proceeds efficiently, and particles having the desired particle size can be obtained.

In the above step (2), it is preferable to cool after completion of the reaction (treatment) and further neutralize to pH 5.0 to 10.0. The neutralization can be performed with an alkaline compound such as an aqueous sodium hydroxide solution or aqueous ammonia. The target rutile titanium dioxide fine particles can be separated by filtering and washing with water after neutralization.

Further, as a method for producing titanium dioxide fine particles, a known method described in “Titanium oxide—physical properties and applied technology” (Kiyono Manabu, p. 255-258 (2000) Gihodo Publishing Co., Ltd.) can be used.

Furthermore, another method for producing metal oxide particles including titanium dioxide particles is disclosed in JP-A-2000-053421 (comprising alkyl silicate as a dispersion stabilizer, and silicon in the alkyl silicate is changed to SiO _2. The weight ratio of the amount converted to TiO ₂ to the amount converted to TiO ₂ in titanium dioxide (SiO ₂ / TiO ₂ ) is 0.7 to 10), JP 2000-063119 A (TiO ₂ Reference can be made to matters described in, for example, a sol in which a composite colloidal particle of —ZrO ₂ —SnO ₂ is used as a nucleus and a surface thereof is coated with a composite oxide colloidal particle of WO ₃ —SnO ₂ —SiO ₂ .

Further, the titanium dioxide particles may be coated with a silicon-containing hydrated oxide. The coating amount of the silicon-containing hydrated compound is preferably 3 to 30% by mass, more preferably 3 to 10% by mass, and further preferably 3 to 8% by mass. This is because when the coating amount is 30% by mass or less, a desired refractive index of the high refractive index layer can be obtained, and when the coating amount is 3% or more, particles can be stably formed.

As a method of coating titanium dioxide particles with a silicon-containing hydrated oxide, it can be produced by a conventionally known method. For example, JP-A-10-158015 (Si / Al hydration to rutile titanium dioxide) Oxide treatment; a method for producing a titanium dioxide sol in which a hydrous oxide of silicon and / or aluminum is deposited on the surface of titanium oxide after peptization in the alkali region of the titanate cake), JP 2000-204301 A (A sol in which a rutile titanium dioxide is coated with a complex oxide of Si and Zr and / or Al. Hydrothermal treatment), JP 2007-246351 (Oxidation obtained by peptizing hydrous titanium dioxide) To a titanium hydrosol, as a stabilizer, the formula R1 _n SiX _4-n (wherein R1 is a C1-C8 alkyl group, glycidyloxy-substituted C 1-C8 alkyl group or C2-C8 alkenyl group, X is an alkoxy group, and n is 1 or 2.) An organoalkoxysilane or a compound having a complexing action with respect to titanium dioxide is added, and silicic acid is added in an alkaline region. Reference can be made to the matters described in, for example, a method for producing a titanium dioxide hydrosol coated with a hydrous oxide of silicon by adding, adjusting pH, and aging to a solution of sodium or silica sol.

The volume average particle diameter of the titanium dioxide particles is preferably 30 nm or less, more preferably 1 to 30 nm, and even more preferably 5 to 15 nm. A volume average particle size of 30 nm or less is preferable from the viewpoint of low haze and excellent visible light transmittance.

Here, the volume average particle diameter is a volume average particle diameter of primary particles or secondary particles dispersed in a medium, and can be measured by a laser diffraction / scattering method, a dynamic light scattering method, or the like.

Specifically, the particles themselves or the particles appearing on the cross section or surface of the refractive index layer are observed with an electron microscope, and the particle diameters of 1,000 arbitrary particles are measured, and d ₁ , d _2. In a group of metal oxide particles having n 1, n 2,..., ni, and nk particles having particle diameters d _i ..., d _k , respectively, where v _i is the volume per particle. The volume average particle size m _v = {Σ (v _i · d _i )} / {Σ (v _i )} is calculated as the average particle size weighted by the volume.

In the present invention, colloidal silica composite emulsion can also be used as a metal oxide in the low refractive index layer. The colloidal silica composite emulsion preferably used in the present invention comprises a polymer or copolymer as a main component at the center of the particle, and is described in JP-A-59-71316 and JP-A-60-127371. It is obtained by polymerizing a monomer having an ethylenically unsaturated bond in the presence of colloidal silica which has been conventionally known by an emulsion polymerization method. The particle diameter of colloidal silica applied to the composite emulsion is preferably less than 40 nm.

The colloidal silica used for the preparation of this composite emulsion usually includes primary particles of 2 to 100 nm. Examples of the ethylenic monomer include (meth) acrylic acid ester having 1 to 18 carbon atoms, aryl group, or allyl group, styrene, α-methylstyrene, vinyl toluene, acrylonitrile, vinyl chloride, vinylidene chloride. , Vinyl acetate, vinyl propionate, acrylamide, N-methylol acrylamide, ethylene, butadiene, and other materials known in the latex industry. In order to further improve the compatibility with colloidal silica, vinyl trimethoxy is used. Vinyl silanes such as silane, vinyl triethoxy silane, γ-methacrylooxypropyl trimethoxy silane, etc. are also used for the dispersion stability of emulsions (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, etc. Anionic monomer Is used as an auxiliary. In addition, two or more types of ethylenic monomers can be used together as necessary.

Further, the ratio of ethylenic monomer / colloidal silica in the emulsion polymerization is preferably 100/1 to 200 in terms of solid content.

Among the colloidal silica composite emulsions used in the present invention, those having a glass transition point in the range of −30 to 30 ° C. are preferable.

In addition, preferred examples of the composition include ethylenic monomers such as acrylic acid esters and methacrylic acid esters, and particularly preferred are copolymers of (meth) acrylic acid esters and styrene, alkyl (meth) acrylates. Examples thereof include a copolymer of ester and (meth) acrylic acid aralkyl ester, and a (meth) acrylic acid alkyl ester and (meth) acrylic acid aryl ester copolymer.

Examples of emulsifiers used in emulsion polymerization include alkyl allyl polyether sulfonic acid soda salt, lauryl sulfonic acid soda salt, alkyl benzene sulfonic acid soda salt, polyoxyethylene nonylphenyl ether sodium nitrate salt, alkyl allyl sulfosuccinate soda salt, sulfo Examples include propyl maleic acid monoalkyl ester soda salt.

(Other additives)
Each refractive index layer forming the dielectric laminated film can contain various additives as necessary.

Specifically, various anionic, cationic or nonionic surfactants; dispersants such as polycarboxylic acid ammonium salt, allyl ether copolymer, benzenesulfonic acid sodium salt, graft compound dispersant, polyethylene glycol type nonionic dispersant; Organic acid salts such as acetate, propionate or citrate; organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, organic phosphate plasticizers, organic phosphorous acid plasticizers, etc. Plasticizers such as phosphoric acid plasticizers; ultraviolet absorbers described in JP-A-57-74193, JP-A-57-87988, and JP-A-62-261476, JP-A-57-74192, JP-A-57 -87989, 60-72785, 61-14659, JP-A-1-95091 and 3-13376, etc .; Japanese Patent Laid-Open Nos. 59-42993, 59-52689, 62-280069, 61-242871, and Japanese Patent Laid-Open No. 4-219266 Optical brighteners described in the Gazettes, etc .; pH adjusters such as sulfuric acid, phosphoric acid, acetic acid, citric acid, sodium hydroxide, potassium hydroxide, potassium carbonate; antifoaming agents; lubricants such as diethylene glycol; Agents; antistatic agents; may contain various known additives such as matting agents.

(Configuration of dielectric multilayer film)
The dielectric multilayer film according to the present invention may have a configuration (laminated film) in which at least one unit composed of a high refractive index layer and a low refractive index layer is stacked. The total number of high refractive index layers and low refractive index layers. Is preferably 300 layers or less, that is, 150 units or less. More preferably, it is 250 layers (125 units) or less, and further, in the order of 100 layers (50 units) or less, 40 layers (20 units) or less, 30 layers (15 units) or less, 20 layers (10 units) or less. preferable. By reducing the number of layers, productivity can be improved and a decrease in transparency due to scattering at the lamination interface can be suppressed.

In addition, the dielectric multilayer film of the present invention may have a structure in which at least one of the above units is laminated. For example, a laminated film in which both the outermost layer and the lowermost layer of the laminated film are high refractive index layers or low refractive index layers. It may be.

In the dielectric multilayer film of the present invention, the high refractive index layer preferably has a refractive index of 1.60 to 2.40, more preferably 1.65 to 2.10. The low refractive index layer of the present invention preferably has a refractive index of 1.30 to 1.50, more preferably 1.34 to 1.50.

In the dielectric multilayer film, it is preferable to design a large difference in refractive index between the high refractive index layer and the low refractive index layer from the viewpoint of increasing the infrared reflectance with a small number of layers. In at least one of the units composed of the high refractive index layer and the low refractive index layer, the refractive index difference between the adjacent high refractive index layer and the low refractive index layer is preferably 0.1 or more, Preferably it is 0.3 or more, More preferably, it is 0.4 or more.

In the dielectric laminated film of the present invention, the difference in refractive index between the adjacent high refractive index layer and low refractive index layer is preferably 0.1 or more, but the high refractive index layer and the low refractive index layer As described above, it is preferable that all refractive index layers satisfy the range defined in the present invention. However, the outermost layer and the lowermost layer may be configured outside the range defined in the present invention.

The reflectance in a specific wavelength region is determined by the difference in refractive index between two adjacent layers (high refractive index layer and low refractive index layer) and the number of layers, and the larger the refractive index difference, the same reflectance can be obtained with a smaller number of layers. . The refractive index difference and the required number of layers can be calculated using commercially available optical design software. For example, in order to obtain an infrared shielding ratio of 90% or more, if the refractive index difference is smaller than 0.1, it is necessary to laminate more than 100 layers, which not only lowers productivity but also scattering at the lamination interface. Increases and transparency decreases. From the viewpoint of improving reflectivity and reducing the number of layers, there is no upper limit to the difference in refractive index, but the limit is substantially about 1.40.

The refractive index difference is obtained by calculating the refractive indexes of the high refractive index layer and the low refractive index layer according to the following method, and the difference between the two is defined as the refractive index difference.

If necessary, each refractive index layer is produced as a single layer using a substrate, and after cutting this sample into 10 cm × 10 cm, the refractive index is determined according to the following method. Using a U-4000 model (manufactured by Hitachi, Ltd.) as a spectrophotometer, the surface opposite to the measurement surface (back surface) of each sample is roughened and then light-absorbed with a black spray. To prevent reflection of light on the back surface, measure the reflectance in the visible light region (400 nm to 700 nm) at 25 points under the condition of regular reflection at 5 degrees, obtain an average value, and calculate the average refractive index from the measurement result Ask for.

Compared to the dielectric laminated film whose material composition is only polymer, since the high refractive index layer contains metal oxide particles, the refractive index of the high refractive index layer can be increased, and the high and low refractive index layers are laminated. It is possible to obtain a high infrared reflectance even if the number of units is reduced to form a thin film.

The total thickness of the infrared shielding film of the present invention is preferably 12 μm to 315 μm, more preferably 15 μm to 200 μm, and still more preferably 20 μm to 100 μm.

In this specification, the terms “high refractive index layer” and “low refractive index layer” refer to the refractive index layer having a higher refractive index when the refractive index difference between two adjacent layers is compared. This means that the lower refractive index layer is the lower refractive index layer. Therefore, the terms “high refractive index layer” and “low refractive index layer” are the same when each refractive index layer constituting the optical reflective film is focused on two adjacent refractive index layers. All forms other than those having a refractive index are included.

(Dielectric multilayer film manufacturing method)
The dielectric multilayer film of the present invention is configured by laminating a unit composed of a high refractive index layer and a low refractive index layer on a substrate. Specifically, as in the method described in US Pat. No. 6,049,419 as described above, in addition to a method of forming a dielectric multilayer film by melt extrusion and stretching of a polymer, water-based high refraction. Examples thereof include a method in which a coating liquid for a refractive index layer and a coating liquid for a low refractive index layer are alternately wet-coated and dried to form a laminate.

As a method for alternately applying a water-based coating solution for a high refractive index layer and a coating solution for a low refractive index layer alternately, the following coating methods are preferably used. For example, as described in roll coating method, rod bar coating method, air knife coating method, spray coating method, curtain coating method, US Pat. Nos. 2,761,419 and 2,761,791 A slide hopper coating method, an extrusion coating method or the like is preferably used. In addition, as a method of applying a plurality of layers in a multilayer manner, sequential multilayer coating or simultaneous multilayer coating may be used.

When the slide hopper coating method is used, the viscosity of the coating solution for the high refractive index layer and the coating solution for the low refractive index layer in the simultaneous multilayer coating is preferably in the range of 5 to 100 mPa · s, more preferably The range is 10 to 50 mPa · s. When the curtain coating method is used, the range of 5 to 1200 mPa · s is preferable, and the range of 25 to 500 mPa · s is more preferable.

The viscosity of the coating solution at 15 ° C. is preferably 100 mPa · s or more, more preferably 100 to 30,000 mPa · s, still more preferably 3,000 to 30,000 mPa · s, and most preferably 10 , 30,000 to 30,000 mPa · s.

As a coating and drying method, a water-based coating solution for a high refractive index layer and a coating solution for a low refractive index layer are heated to 30 ° C. or more, and after coating, the temperature of the coating film formed is 1 to 15 It is preferable that the temperature is once cooled to 10 ° C. and dried at 10 ° C. or more. More preferably, the drying conditions are wet bulb temperature 5 to 50 ° C. and film surface temperature 10 to 50 ° C. Moreover, as a cooling method immediately after application | coating, it is preferable to carry out by a horizontal set system from a viewpoint of the formed coating-film uniformity.

The thickness per layer (thickness after drying) of the high refractive index layer is preferably 20 to 1000 nm, and more preferably 50 to 500 nm.

The thickness per layer of the low refractive index layer (thickness after drying) is preferably 20 to 800 nm, and more preferably 50 to 350 nm.

What is necessary is just to apply | coat so that the coating thickness of the coating liquid for high refractive index layers and the coating liquid for low refractive index layers may become the preferable thickness at the time of drying as shown above.

[Infrared shielding film]
The total thickness of the infrared shielding film of the present invention is preferably 12 μm to 315 μm, more preferably 15 μm to 200 μm, and still more preferably 20 μm to 100 μm.

The infrared shielding film of the present invention has a conductive layer, an antistatic layer, a gas barrier layer, an easy-adhesion layer (for the purpose of adding further functions under the base material or on the outermost surface layer opposite to the base material). Adhesive layer), antifouling layer, deodorant layer, droplet layer, slippery layer, hard coat layer, wear-resistant layer, antireflection layer, electromagnetic wave shielding layer, ultraviolet absorption layer, infrared absorption layer, printing layer, fluorescence Light emitting layer, hologram layer, release layer, adhesive layer, adhesive layer, infrared cut layer (metal layer, liquid crystal layer) other than the high refractive index layer and low refractive index layer of the present invention (colored layer (visible light absorbing layer)), combination One or more functional layers such as an intermediate film layer used for glass may be included. Hereinafter, the adhesive layer, the infrared absorption layer, and the hard coat layer which are preferable functional layers will be described.

<Adhesive layer>
The infrared shielding film of the present invention can be provided with an adhesive layer on any outermost layer surface (excluding the separator). An adhesive layer is a layer provided in order to stick the infrared shielding film of this invention with respect to a glass surface etc., for example.

The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is not particularly limited, and examples thereof include acrylic pressure-sensitive adhesives, silicon pressure-sensitive adhesives, urethane pressure-sensitive adhesives, polyvinyl butyral pressure-sensitive adhesives, and ethylene-vinyl acetate pressure-sensitive adhesives. Can do.

When the infrared shielding film of the present invention is pasted on a window glass, water is sprayed on the window, and the pasting method of matching the adhesive layer of the infrared shielding film on the wet glass surface, the so-called water pasting method is re-stretched, It is preferably used from the viewpoint of repositioning and the like. For this reason, an acrylic pressure-sensitive adhesive that has a weak adhesive force in the presence of water is preferably used.

The acrylic pressure-sensitive adhesive used may be either solvent-based or emulsion-based, but is preferably a solvent-based pressure-sensitive adhesive because it is easy to increase the adhesive strength and the like, and among them, those obtained by solution polymerization are preferable. Examples of the raw material for producing such a solvent-based acrylic pressure-sensitive adhesive by solution polymerization include, for example, acrylic acid esters such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and acryl acrylate as main monomers serving as a skeleton, As a comonomer to improve cohesive strength, vinyl acetate, acrylonitrile, styrene, methyl methacrylate, etc., to further promote crosslinking, to give stable adhesive strength, and to maintain a certain level of adhesive strength even in the presence of water Examples of the functional group-containing monomer include methacrylic acid, acrylic acid, itaconic acid, hydroxyethyl methacrylate, and glycidyl methacrylate. Since the adhesive layer of the laminated film requires a particularly high tack as the main polymer, those having a low glass transition temperature (Tg) such as butyl acrylate are particularly useful.

This adhesive layer contains additives such as stabilizers, surfactants, UV absorbers, flame retardants, antistatic agents, antioxidants, thermal stabilizers, lubricants, fillers, coloring, adhesion modifiers, etc. It can also be made. In particular, when used as a window sticker as in the present invention, the addition of an ultraviolet absorber is also effective for suppressing deterioration of the infrared shielding film due to ultraviolet rays.

The thickness of the adhesive layer is preferably 1 to 100 μm, more preferably 3 to 50 μm, and even more preferably 10 to 30 μm. If it is 1 micrometer or more, there exists a tendency for adhesiveness to improve and sufficient adhesive force is acquired. On the other hand, if the thickness is 100 μm or less, not only the transparency of the infrared shielding film is improved, but also after the infrared shielding film is attached to the window glass, when it is peeled off, cohesive failure does not occur between the adhesive layers. There is a tendency for the remaining adhesive to disappear.

<Infrared absorbing layer>
The infrared shielding film of this invention can have an infrared absorption layer in arbitrary positions.

The material contained in the infrared absorption layer is not particularly limited, and examples thereof include an ultraviolet curable resin, a photopolymerization initiator, and an infrared absorber.

UV curable resins are superior in hardness and smoothness to other resins, and are also advantageous from the viewpoint of dispersibility of tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), and thermally conductive metal oxides. It is. The ultraviolet curable resin can be used without particular limitation as long as it forms a transparent layer by curing, and examples thereof include silicone resins, epoxy resins, vinyl ester resins, acrylic resins, and allyl ester resins. More preferred is an acrylic resin from the viewpoint of hardness, smoothness and transparency.

From the viewpoint of hardness, smoothness, and transparency, the acrylic resin is a reactive silica particle having a photosensitive group having photopolymerization reactivity introduced on its surface as described in International Publication No. 2008/035669 ( In the following, it is preferable to simply include “reactive silica particles”. Here, examples of the photopolymerizable photosensitive group include a polymerizable unsaturated group represented by a (meth) acryloyloxy group. The ultraviolet curable resin contains a photopolymerizable photosensitive group introduced on the surface of the reactive silica particles and a compound capable of photopolymerization, for example, an organic compound having a polymerizable unsaturated group. There may be. In addition, a polymerizable unsaturated group-modified hydrolyzable silane reacts with a silica particle that forms a silyloxy group and is chemically bonded to the silica particle by a hydrolysis reaction of the hydrolyzable silyl group. Can be used as conductive silica particles. Here, the average particle diameter of the reactive silica particles is preferably 0.001 to 0.1 μm. By setting the average particle diameter in such a range, transparency, smoothness, and hardness can be satisfied in a well-balanced manner.

Further, the acrylic resin may contain a structural unit derived from a fluorine-containing vinyl monomer from the viewpoint of adjusting the refractive index. Fluorine-containing vinyl monomers include fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, etc.), (meth) acrylic acid moieties or fully fluorinated alkyl ester derivatives (eg, Biscoat 6FM (commodity) Name, manufactured by Osaka Organic Chemical Industry Co., Ltd.), R-2020 (trade name, manufactured by Daikin Industries, Ltd.), and the like, and fully or partially fluorinated vinyl ethers.

As the photopolymerization initiator, known ones can be used, either alone or in combination of two or more.

Inorganic infrared absorbers that can be included in the infrared absorption layer include tin-doped indium oxide (ITO), antimony-doped tin oxide (from the viewpoint of visible light transmittance, infrared absorptivity, dispersibility in the resin, etc. ATO), zinc antimonate, lanthanum hexaboride (LaB ₆ ), cesium-containing tungsten oxide (Cs _0.33 WO ₃ ) and the like are preferable. These may be used alone or in combination of two or more. The average particle size of the inorganic infrared absorber is preferably 5 to 100 nm, more preferably 10 to 50 nm. If it is less than 5 nm, the dispersibility in the resin and the infrared absorptivity may be lowered. On the other hand, if it is larger than 100 nm, the visible light transmittance may decrease. The average particle size is measured by taking an image with a transmission electron microscope, randomly extracting, for example, 50 particles, measuring the particle size, and averaging the results. Moreover, when the shape of particle | grains is not spherical, it defines as what was calculated by measuring a major axis.

The content of the inorganic infrared absorber in the infrared absorption layer is preferably 1 to 80% by mass, and more preferably 5 to 50% by mass with respect to the total mass of the infrared absorption layer. If the content is 1% or more, a sufficient infrared absorption effect appears, and if it is 80% or less, a sufficient amount of visible light can be transmitted.

The infrared absorption layer may contain other infrared absorbers such as metal oxides other than those described above, organic infrared absorbers, metal complexes, and the like within the scope of the effects of the present invention. Specific examples of such other infrared absorbers include, for example, diimonium compounds, aluminum compounds, phthalocyanine compounds, organometallic complexes, cyanine compounds, azo compounds, polymethine compounds, quinone compounds, diphenylmethane compounds. Compounds, triphenylmethane compounds, and the like.

The thickness of the infrared absorption layer is preferably 0.1 to 50 μm, more preferably 1 to 20 μm. If it is 0.1 μm or more, the infrared absorption ability tends to be improved. On the other hand, if it is 50 μm or less, the crack resistance of the coating film is improved.

<Hard coat layer>
The infrared shielding film of the present invention is a hard coat containing a resin that is cured by heat, ultraviolet rays, or the like, as a surface protective layer for enhancing scratch resistance, on the uppermost layer opposite to the side having the adhesive layer of the substrate. It is preferable to laminate the layers. In the present invention, it is particularly preferable that the hard coat layer is formed above the layer containing the flat metal particles when the base material is disposed below the layer containing the flat metal particles.

Examples of the curable resin used in the hard coat layer include a thermosetting resin and an ultraviolet curable resin, but an ultraviolet curable resin is preferable because of easy molding, and among them, a pencil hardness is at least 2H. Is more preferable. Such curable resins can be used alone or in combination of two or more. As the curable resin, a commercially available product may be used, or a synthetic product may be used.

As such an ultraviolet curable resin, it is synthesized from, for example, a polyfunctional acrylate resin such as acrylic acid or methacrylic acid ester having a polyhydric alcohol, and acrylic acid or methacrylic acid having a diisocyanate and a polyhydric alcohol. Such polyfunctional urethane acrylate resins can be mentioned. Furthermore, polyether resins, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins or polythiol polyene resins having an acrylate-based functional group can also be suitably used.

As reactive diluents for these resins, relatively low viscosity 1,6-hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, hexanediol (methacrylate) ) Bifunctional or higher functional monomers and oligomers such as acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, neopentylglycol di (meth) acrylate, and Acrylic esters such as N-vinylpyrrolidone, ethyl acrylate, propyl acrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, hexyl Methacrylic acid esters such as tacrylate, isooctyl methacrylate, 2-hydroxyethyl methacrylate, cyclohexyl methacrylate, nonylphenyl methacrylate, derivatives such as tetrahydrofurfuryl methacrylate and its caprolactone modified products, styrene, α-methylstyrene, acrylic acid, etc. A monofunctional monomer or the like can be used. These reactive diluents can be used alone or in combination of two or more.

Furthermore, benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyl methyl ketal are used as photosensitizers (radical polymerization initiators) for these resins. Alkyl ethers; acetophenones such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone; anthraquinones such as methylanthraquinone, 2-ethylanthraquinone, 2-amylanthraquinone; thioxanthone, 2,4 -Thioxanthones such as diethylthioxanthone and 2,4-diisopropylthioxanthone; Ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; Benzophenone and 4,4-bismethi Benzophenones such as amino benzophenone and azo compounds can be used. These may be used alone or in combination of two or more. In addition, tertiary amines such as triethanolamine and methyldiethanolamine; photoinitiators such as 2-dimethylaminoethylbenzoic acid and benzoic acid derivatives such as ethyl 4-dimethylaminobenzoate can be used in combination. it can. The use amount of these radical polymerization initiators is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass with respect to 100 parts by mass of the polymerizable component of the resin.

In addition, you may mix | blend a well-known general coating additive with the above-mentioned curable resin as needed. For example, a silicone-based or fluorine-based paint additive that imparts leveling or surface slip properties is effective in preventing scratches on the surface of a cured film, and in the case of using ultraviolet rays as active energy rays, When the additive bleeds to the air interface, the inhibition of curing of the resin by oxygen can be reduced, and an effective degree of curing can be obtained even under low irradiation intensity conditions.

The hard coat layer preferably contains inorganic fine particles. Preferable inorganic fine particles include fine particles of an inorganic compound containing a metal such as titanium, silica, zirconium, aluminum, magnesium, antimony, zinc or tin. The average particle size of the inorganic fine particles is preferably 1000 nm or less, and more preferably in the range of 10 to 500 nm, from the viewpoint of ensuring visible light transmittance. In addition, the inorganic fine particles have higher photopolymerization reactivity such as monofunctional or polyfunctional acrylates because the higher the bonding strength with the curable resin that forms the hard coat layer, the more the dropping from the hard coat layer can be suppressed. Those having a group introduced on the surface are preferred.

The thickness of the hard coat layer is preferably 0.1 μm to 50 μm, more preferably 1 to 20 μm. If it is 0.1 μm or more, the hard coat property tends to be improved. Conversely, if it is 50 μm or less, the transparency of the infrared shielding film tends to be improved.

The hard coat layer may also serve as the above-described infrared absorption layer.

<Method for forming adhesive layer, infrared absorbing layer, hard coat layer>
As an adhesive coating method, any known method can be used, for example, bar coating method, die coater method, gravure roll coater method, blade coater method, spray coater method, air knife coating method, dip coating method, A transfer method and the like are preferable, and they can be used alone or in combination. These can be appropriately formed into a solution in a solvent capable of dissolving the pressure-sensitive adhesive, or can be applied using a dispersed coating solution, and known solvents can be used.

For the formation of the adhesive layer, it may be applied directly to the infrared shielding film by the previous coating method, or once coated on the release film and dried, the infrared shielding film is then bonded. The adhesive may be transferred. The drying temperature at this time is preferably such that the residual solvent is reduced as much as possible. For this purpose, the drying temperature and time are not specified, but a drying time of 10 seconds to 5 minutes is preferably provided at a temperature of 50 to 150 ° C. Is good. In addition, since the adhesive has fluidity, the reaction is not yet completed immediately after drying by heating, and curing is necessary to complete the reaction and obtain a stable adhesive force. In general, when heated at room temperature for about one week or longer, for example, about 50 ° C. is preferably 3 days or longer. In the case of heating, if the temperature is raised too much, the flatness of the plastic film may be deteriorated.

The method for forming the infrared absorption layer and the hard coat layer is not particularly limited, but a bar coat method, a die coater method, a gravure roll coater method, a spin coating method, a spray method, a blade coating method, an air knife coating method, a dip coating method. It is preferably formed by a wet coating method such as a transfer method or a dry coating method such as a vapor deposition method.

As a method of curing by irradiation with ultraviolet rays, ultraviolet rays in a wavelength region of preferably 100 to 400 nm, more preferably 200 to 400 nm, emitted from an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a metal halide lamp, etc. are irradiated, or The irradiation can be performed by irradiating an electron beam having a wavelength region of 100 nm or less emitted from a scanning or curtain type electron beam accelerator.

<Lamination order of infrared shielding film>
The lamination order of each layer of the infrared shielding film of the present invention is not particularly limited. However, from the viewpoint of further improving the effect of the present invention, it is preferable that the dielectric multilayer film is provided on the light (sunlight) incident side of the layer including the flat metal particles. By adopting such a configuration, the amount of light incident on the layer containing the flat metal particles can be reduced by the dielectric multilayer film, so that the amount of heat generated by the layer containing the flat metal particles is reduced and higher shielding is achieved. A thermal effect can be obtained. Furthermore, by setting it as the said structure, it can anticipate also suppressing the temporal discoloration of a film resulting from discoloration of a flat metal particle.

The infrared shielding film of the present invention is broadly divided into (1) a structure in which a layer containing flat metal particles and a dielectric multilayer film are formed on one surface of a substrate, or (2) via a substrate. A configuration in which a layer containing flat metal particles and a dielectric multilayer film are formed is adopted. Each will be described below.

(1) Configuration in which a layer containing flat metal particles and a dielectric multilayer film are formed on one surface of a substrate For this configuration (1), the infrared shielding film of the present invention is pasted on the indoor side of a window glass ( (Internal paste) specification can be adopted. As the specification, for example, a layer containing flat metal particles, a dielectric multilayer film, and an adhesive layer are laminated on the substrate surface in this order, and a hard surface is formed on the substrate surface opposite to the side where these layers are laminated. The form which coats a coat layer is mentioned as a preferable example (FIG. 3A, the structure 1 for internal bonding). With such a configuration, a high infrared shielding effect can be obtained. As long as the positional relationship between the flat metal particle layer and the dielectric multilayer film is the same, for example, an adhesive layer, a base material, a dielectric multilayer film, a layer containing flat metal particles, and a hard coat layer may be used in this order. . Moreover, you may have another functional layer and a base material between the dielectric multilayer film and the layer containing flat metal particle.

In the present configuration (1), the infrared shielding film of the present invention may be affixed (outside pasting) to the outside of the window glass. As a preferred example in the specification, a dielectric multilayer film, a layer containing flat metal particles, and an adhesive layer are laminated in this order on the substrate surface, and the substrate on the side opposite to the side on which these layers are laminated. In this configuration, a hard coat layer is coated on the surface. If the positional relationship between the layer containing the flat metal particles and the dielectric multilayer film is the same as in the case of the internal bonding, for example, an adhesive layer, a substrate, a layer containing the flat metal particles, a dielectric multilayer film, a hard It may be in the order of the coat layer (FIG. 3C, configuration 3 for external pasting). Moreover, you may have another functional layer and a base material between the dielectric multilayer film and the layer containing flat metal particle.

(2) Configuration in which a layer containing flat metal particles and a dielectric multilayer film are formed via a substrate The infrared shielding film of the present invention has a dielectric multilayer film formed on one surface of the substrate, The form currently formed on the other surface of a base material may be sufficient as the layer containing a flat metal particle. That is, the form in which the dielectric multilayer film and the layer containing flat metal particles are mutually formed through the substrate may be employed.

In such a configuration, the positional relationship among the layer containing the flat metal particles, the dielectric multilayer film, and the substrate is such that the dielectric multilayer film, the substrate, and the flat metal particles are from the side on which light (for example, sunlight) is incident. It is preferable that the layers are arranged in the order of the layers.

For this configuration (2), it is possible to adopt a specification in which the infrared reflective film of the present invention is pasted (internally pasted) on the indoor side of the window glass. Thereby, a particularly high infrared shielding effect can be obtained. As the use, for example, a layer containing flat metal particles is disposed on one surface side of the base material, and a dielectric multilayer film is disposed on the opposite surface, and the flat metal particles are based on the base material. A preferable example is a form in which a hard coat layer is laminated on the layer containing, and an adhesive layer is laminated on the dielectric multilayer film (FIG. 3B, internal pasting configuration 2). Other layers may be inserted between the layers as long as they are within the above stacking order.

Further, in the present configuration (2), the infrared shielding film of the present invention may be affixed (outside pasting) to the outside of the window glass. As a preferred example in the specification, a dielectric multilayer film on one surface of a base material and a hard coat layer covering the dielectric multilayer film are laminated in this order, and a layer containing flat metal particles on the other surface of the base material, and It is the structure which laminated | stacked in order of the adhesion layer which covers this (FIG. 3D, the structure 4 for external pasting). Further, similarly to the in-applied specification, other layers may be inserted between the respective layers as long as they are within the above-described stacking order.

In addition, it is more preferable to use the inner-pasting specification among the above-mentioned inner-pasting specifications and outer-pasting specifications.

In the in-adhesion specification, the adhesive layer is arranged on the side on which the dielectric multilayer film is formed, not on the side on which the layer containing flat metal particles is formed, based on the base material. In other words, in the in-adhesion specification, when a film is applied to a glass surface or the like, water is not sprayed on the layer containing flat metal particles that are greatly related to drainage efficiency, but between the dielectric multilayer film and the glass surface. It becomes the composition which sprays water. Therefore, the effect of obtaining good adhesiveness can be maximized without reducing the efficiency of drainage by adopting the in-bonding specification.

[Infrared shield]
The infrared shielding film of the present invention can be applied to a wide range of fields. For example, as a film for window pasting such as heat ray reflective film that gives heat ray reflection effect, film for agricultural greenhouses, etc. It is mainly used for the purpose of improving the weather resistance and suppressing the excessive increase in the temperature in the house. Moreover, it is used suitably also as an infrared shielding film for motor vehicles pinched | interposed between glass, such as laminated glass for motor vehicles. In this case, since the infrared shielding film can be sealed from outside air gas, it is preferable from the viewpoint of durability.

Particularly, the infrared shielding film according to the present invention is suitably used for a member to be bonded to a substrate such as glass or a glass substitute resin directly or via an adhesive.

That is, this invention provides the infrared shielding body which provides the infrared shielding film of this invention in the at least one surface of a base | substrate.

Preferable substrates include plastic substrates, metal substrates, ceramic substrates, cloth substrates, etc., and the infrared shielding film of the present invention is applied to substrates of various forms such as film, plate, sphere, cube, and cuboid. Can be provided. Among these, a plate-shaped ceramic substrate is preferable, and an infrared shielding body in which the infrared shielding film of the present invention is provided on a glass plate is more preferable. Examples of the glass plate include float plate glass and polished plate glass described in JIS R3202: 1996, and the glass thickness is preferably 0.01 mm to 20 mm.

As a method for providing the infrared shielding film of the present invention on the substrate, a method in which an adhesive layer is coated on the infrared shielding film as described above, and is attached to the substrate via the adhesive layer is suitably used.
As a pasting method, a dry pasting method in which a film is pasted on a substrate as it is, and a water pasting method as described above can be applied, but in order to prevent air from entering between the substrate and the infrared shielding film, From the viewpoint of ease of construction, such as positioning of the infrared shielding film on the substrate, it is more preferable to bond by a water bonding method.

The infrared shielding body of the present invention is an embodiment in which the infrared reflecting film of the present invention is provided on at least one surface of the substrate. However, the infrared shielding film of the present invention or the infrared shielding film of the present invention is provided on a plurality of surfaces of the substrate. An aspect in which a plurality of bases are provided may be used. For example, the aspect which provided the infrared reflective film of this invention on both surfaces of the above-mentioned plate glass, the adhesion layer was coated on both surfaces of the infrared reflective film of this invention, and the above-mentioned plate glass was bonded together on both surfaces of the infrared reflective film. A glass-like aspect may be sufficient.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "mass part" or "mass%" is represented.

Example 1-1
[Production of infrared shielding film]
<Formation of a layer containing tabular silver particles>
(Preparation of coating solution containing flat silver particles)
2.5 mL of 0.5 g / L polystyrene sulfonic acid aqueous solution was added to 50 mL of 2.5 mM sodium citrate aqueous solution and heated to 35 ° C. To this solution, 3 mL of 10 mM aqueous sodium borohydride solution was added, and 50 mL of 0.5 mM aqueous silver nitrate solution was added with stirring at 20 mL / min. This solution was stirred for 30 minutes to prepare a seed solution.

Next, 87.1 mL of ion-exchanged water was added to 132.7 mL of a 2.5 mM sodium citrate aqueous solution and heated to 35 ° C. To this solution, 2 mL of 10 mM aqueous ascorbic acid solution was added, 42.4 mL of the seed solution was added, and 79.6 mmL of 0.5 mM aqueous silver nitrate solution was added at 10 mL / min with stirring. After stirring for 30 minutes, 71.1 mL of 0.35 M potassium hydroquinonesulfonate aqueous solution was added, and 200 g of 7 mass% gelatin aqueous solution was added.

To this solution, a white precipitate mixed solution prepared by mixing 107 mL of a 0.25 M aqueous sodium sulfite solution and 107 mL of a 0.47 M aqueous silver nitrate solution was added. Immediately after adding the white precipitate mixture, 72 mL of 0.17 M aqueous NaOH was added. At this time, an aqueous NaOH solution was added while adjusting the addition rate so that the pH did not exceed 10. This was stirred for 300 minutes to obtain a liquid in which tabular silver particles were dispersed (a coating liquid containing tabular silver particles).

In the obtained flat silver particle-containing coating solution, it was confirmed that silver particles having a substantially hexagonal shape and a flat plate shape were formed. Further, when measured by the following method, it was found that flat silver particles having an average equivalent circle diameter of 230 nm, an average grain thickness of 16 nm, and an aspect ratio of 14.3 were generated.

(Evaluation of tabular silver particles)
Average circle equivalent diameter of tabular silver particles The average circle equivalent diameter of tabular silver particles is the shape of 200 particles arbitrarily extracted from the observed SEM image, A is a substantially hexagonal or substantially disc shaped particle, and tears Image analysis was performed with B having an irregularly shaped particle such as a mold, the equivalent circle diameter of 100 particles corresponding to A was measured with a digital caliper, and the average value was taken as the average equivalent circle diameter.

Average particle thickness The obtained tabular silver particle-containing coating solution was dropped onto a glass substrate and dried, and the thickness of one tabular silver particle was measured using an atomic force microscope (AFM) (Nanocute II, manufactured by Seiko Instruments Inc.). ). The measurement conditions using the AFM were a self-detecting sensor, DFM mode, a measurement range of 5 μm, a scanning speed of 180 seconds / frame, and a data point of 256 × 256.

Aspect Ratio The aspect ratio was calculated by dividing the average equivalent circle diameter by the average grain thickness from the average equivalent circle diameter and the average grain thickness of the obtained tabular silver particles.

(Formation of a layer containing tabular silver particles)
On a 50 μm-thick polyethylene terephthalate (PET) film (Toyobo Co., Ltd., A4300: double-sided easy-adhesion layer), the area ratio obtained as described above for the flat silver particle-containing coating solution obtained above was 20 %, And a dry film thickness of 5 μm was applied with a wire bar and dried at a drying temperature of 120 ° C. for 2 minutes to form a layer containing tabular silver particles.

(Evaluation of orientation angle of tabular silver particles)
The prepared film having a layer containing tabular silver particles was embedded with an epoxy resin and then cleaved with a razor in a frozen state with liquid nitrogen to prepare a vertical section sample of the film. This vertical section sample was observed with a scanning electron microscope (SEM), and the inclination angle (absolute value) of the substrate with respect to the horizontal plane was calculated as an average value for 100 silver tabular grains.

<Dielectric multilayer film No. 1-1 Production>
In accordance with the melt extrusion method described in US Pat. No. 6,049,419, a laminate of polyethylene naphthalate (PEN: refractive index 1.65) and polymethyl methacrylate (PMMA: refractive index 1.40) is 1 After stacking 50 units (100 layers in total), stretch 2 times in length and 2 times in width, heat fix and cool so that the physical film thickness is 159 nm for PEN layer and 190 nm for PMMA layer The dielectric multilayer film No. 1-1 was produced.

<Layer containing flat silver particles and dielectric multilayer film No. Bonding with 1-1>
The produced dielectric multilayer film No. 1-1 was bonded with a film having a layer containing the above-mentioned tabular silver particles by a bonding machine so as to have a layer structure as shown in FIG. 3A. At this time, the tension at the time of bonding on the PET base material side is 5 kg / m, the tension at the time of bonding on the dielectric multilayer film side is 5 kg / m, the nip roller temperature is 140 ° C., and the speed is 2 m / min. Through the process, a laminate was obtained.

<Formation of hard coat layer (HC layer)>
To 90 parts by mass of a methyl ethyl ketone solvent, 7.5 parts by mass of an ultraviolet curable hard coat material (UV-7600B: UV curable urethane acrylate resin, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) is added, and then a photopolymerization initiator (Irgacure ( (Registered Trademark) 184: Ciba Specialty Chemicals, 1-hydroxycyclohexyl phenyl ketone (0.5 part by mass) was added and mixed by stirring to prepare a hard coat layer coating solution (HC-1).

Next, the hard coat layer coating solution (HC-1) was applied to the laminate produced as described above with a wire bar so as to have the layer structure shown in FIG. 3A, and dried with hot air at 70 ° C. for 3 minutes. Thereafter, in the atmosphere, a hard coat layer having a thickness of 2 μm was formed by curing at a curing condition of 400 mJ / cm ² using an ultraviolet curing apparatus (using a high-pressure mercury lamp) manufactured by Eye Graphics.

<Formation of adhesive layer>
60 parts by mass of ethyl acetate and 20 parts by mass of toluene are mixed, and 20 g of acrylic adhesive (Arontack (registered trademark) M-300: manufactured by Toagosei Co., Ltd.) is added and mixed by stirring to obtain an adhesive coating solution. Prepared.

The pressure-sensitive adhesive layer employs a method in which a pressure-sensitive adhesive layer is applied to a separator film and then bonded to the laminate.

As the separator film, a 25 μm thick polyester film (Therapel (registered trademark): manufactured by Toyo Metallizing Co., Ltd.) was used. On the separator film, a pressure-sensitive adhesive coating solution was applied with a wire bar and dried at 80 ° C. for 2 minutes to produce a film with a pressure-sensitive adhesive layer having a thickness of 18 μm (film with a pressure-sensitive adhesive layer). The pressure-sensitive adhesive layer surface of the film with the pressure-sensitive adhesive layer was bonded to the laminate produced as described above so as to have the layer configuration (internal bonding configuration 1) shown in FIG. 3A. At this time, the tension at the time of bonding on the laminated body side was set to 10 kg / m, and the tension at the time of bonding of the film with the adhesive layer was set to 30 kg / m.

As described above, an infrared shielding film was produced.

Example 1-2
An infrared shielding film was produced in the same manner as in Example 1-1 except that the drying temperature was set to 100 ° C. in the above (formation of a layer containing tabular silver particles).

(Example 1-3)
An infrared shielding film was produced in the same manner as in Example 1-1 except that the drying temperature was set to 80 ° C. in the above (formation of a layer containing tabular silver particles).

(Example 1-4)
An infrared shielding film was produced in the same manner as in Example 1-1 except that the drying temperature was set to 65 ° C. in the above (formation of a layer containing tabular silver particles).

(Example 1-5)
<Dielectric multilayer film No. Preparation of 1-2>
(Preparation of coating solution for low refractive index layer)
To 500 parts by mass of pure water, 10.0 parts by mass of water-soluble resin PVA224 (manufactured by Kuraray Co., Ltd., saponification degree 88 mol%, degree of polymerization 1000) was added, and further water-soluble resin R1130 (manufactured by Kuraray Co., Ltd.). , Silanol-modified polyvinyl alcohol) 5.0 parts by mass, and then 2.0 parts by mass of water-soluble resin AZF8035 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) are added and dissolved by heating to 70 ° C. while mixing. An aqueous resin solution was obtained.

Next, the entire amount of the water-soluble resin aqueous solution was added and mixed in 350 parts by mass of 10% by mass acidic silica sol (Snowtex (registered trademark) OXS: manufactured by Nissan Chemical Industries, Ltd.) containing silica fine particles having an average particle diameter of 5 nm. Furthermore, 0.3 parts by mass of Lapisol (registered trademark) A30 (manufactured by NOF Corporation) was added as an anionic surfactant, stirred for 1 hour, and then finished with pure water to 1000.0 g for a low refractive index layer. A coating solution was prepared.

(Preparation of titanium dioxide sol aqueous dispersion)
To an aqueous suspension (TiO ₂ concentration 100 g / L) 10 L (liter) in which titanium dioxide hydrate is suspended in water, an aqueous sodium hydroxide solution (concentration 10 mol / L) is added under stirring 30 L, 90 The mixture was heated to 0 ° C. and aged for 5 hours, and then neutralized with hydrochloric acid, filtered, and washed with water. In the above reaction (treatment), titanium dioxide hydrate was obtained by thermal hydrolysis of an aqueous titanium sulfate solution according to a known method.

The base-treated titanium compound was suspended in pure water so as to have a TiO ₂ concentration of 20 g / L, and citric acid was added in an amount of 0.4 mol% with respect to the amount of TiO ₂ with stirring, and the temperature was raised. When the liquid temperature reached 95 ° C., concentrated hydrochloric acid was added to a hydrochloric acid concentration of 30 g / L, and the mixture was stirred for 3 hours while maintaining the liquid temperature.

When the pH and zeta potential of the obtained titanium dioxide sol solution were measured, the pH was 1.4 and the zeta potential was +40 mV. Furthermore, when the particle size was measured with a Zetasizer Nano manufactured by Malvern, the average particle size was 35 nm, and the monodispersity was 16%. Also, the titanium oxide sol solution was dried at 105 ° C. for 3 hours to obtain a particulate powder, and X-ray diffraction measurement was performed using JDX-3530 type manufactured by JEOL Datum Co., Ltd. to confirm that the particles were rutile type particles. did. The volume average particle diameter was 10 nm.

4 kg of pure water was added to 1 kg of a 20.0 mass% titanium dioxide sol aqueous dispersion containing rutile-type titanium dioxide fine particles having a volume average particle diameter of 10 nm.

(Preparation of silicic acid aqueous solution)
An aqueous silicic acid solution having a SiO ₂ concentration of 2.0 mass% was prepared.

(Preparation of silica-modified titanium dioxide particles)
2 kg of pure water was added to 0.5 kg of the above 10.0% by mass titanium dioxide sol aqueous dispersion, followed by heating to 90 ° C. Next, 1.3 kg of the above silicic acid aqueous solution is gradually added, followed by heat treatment at 175 ° C. for 18 hours in an autoclave, and further concentrated to titanium dioxide having a rutile structure, and the coating layer is SiO ₂ . 20% by mass of particles was obtained.

(Preparation of coating solution for high refractive index layer)
28.9 parts by weight of the silica-modified titanium dioxide particle sol aqueous dispersion obtained above, 10.5 parts of a 1.92% by weight aqueous citric acid solution, and 10% by weight of an allyl ether copolymer (AKM) -0531 (manufactured by NOF Corporation) 2.0 parts aqueous solution and 9.0 parts 3% by weight boric acid aqueous solution were mixed to prepare a silica-modified titanium dioxide particle dispersion.

Next, 33.5 parts of a 5.0 mass% aqueous solution of polyvinyl alcohol (PVA217; manufactured by Kuraray Co., Ltd.) was added to 16.3 parts of pure water while stirring the titanium dioxide dispersion. Further, 0.5 part of a 1% by weight aqueous solution of an anionic surfactant (Lapisol (registered trademark) A30, manufactured by NOF Corporation) was added, and finally finished to 1000 parts with pure water, for a high refractive index layer. A coating solution was prepared.

The refractive index of the low refractive index layer was 1.44 as measured by the above method. The refractive index of the high refractive index layer measured in the same manner was 1.92.

(Formation of dielectric multilayer)
Using a slide hopper applicator that can apply multiple layers at the same time, the coating solution for the low refractive index layer and the coating solution for the high refractive index layer prepared in the above are further refracted alternately so that the film surface side becomes the low refractive index layer. The refractive index layer and the low refractive index layer were laminated, and simultaneous multilayer coating was performed on the film while keeping the temperature at 45 ° C. so that the total number of laminated layers was 12. Immediately after that, after setting the film surface by blowing cold air for 1 minute under the condition that the film surface is 15 ° C. or less, it was dried by blowing hot air of 80 ° C. 1-2 was formed. When the cross section of the coating film was observed by SEM, the film thickness of the low refractive index layer was 170 nm, and the film thickness of the high refractive index layer was 130 nm.

In this way, the dielectric multilayer film No. In place of 1-1, dielectric multilayer film No. An infrared shielding film was produced in the same manner as in Example 1-1 except that 1-2 was formed.

(Example 1-6)
An infrared shielding film was produced in the same manner as in Example 1-5 except that the drying temperature was set to 100 ° C. in the above (formation of a layer containing tabular silver particles).

(Example 1-7)
An infrared shielding film was produced in the same manner as in Example 1-5 except that the drying temperature was set to 80 ° C. in the above (formation of a layer containing tabular silver particles).

(Example 1-8)
An infrared shielding film was produced in the same manner as in Example 5 except that the drying temperature was 65 ° C. in the above (formation of a layer containing tabular silver particles).

(Example 1-9)
Infrared rays were obtained in the same manner as in Example 1-1 except that the hard coat layer coating solution (HC-2) prepared as follows was used instead of the hard coat layer coating solution (HC-1). A shielding film was produced.

To 90 parts by mass of methyl ethyl ketone solvent, 7.5 parts by mass of an ultraviolet curable hard coat material (UV-7600B: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was added, and then a photopolymerization initiator (Irgacure (registered trademark) 184: Ciba 0.5 parts by mass (made by Specialty Chemicals) was added and mixed with stirring. Next, 2 parts by mass of ATO powder (ultrafine particle ATO: manufactured by Sumitomo Metal Mining Co., Ltd.), which is an inorganic infrared absorber, is added and stirred at high speed with a homogenizer, whereby an infrared absorber-containing hard coat layer coating solution (HC) -2) was produced.

Example 1-10
An infrared shielding film was produced in the same manner as in Example 1-5 except that the above hard coat layer coating solution (HC-2) was used instead of the hard coat layer coating solution (HC-1). .

(Example 1-11)
An infrared shielding film was produced in the same manner as in Example 1-1, except that the layers were laminated with the layer structure (internal bonding structure 2) as shown in FIG. 3B.

(Example 1-12)
An infrared shielding film was produced in the same manner as in Example 1-5 except that the layers were laminated with the layer structure (internal bonding structure 2) as shown in FIG. 3B.

(Example 1-13)
An infrared shielding film was produced in the same manner as in Example 1-1 except that the layers were laminated in a layer configuration (outer attachment configuration 3) as shown in FIG. 3C.

(Example 1-14)
An infrared shielding film was produced in the same manner as in Example 1-5, except that the layers were laminated in the layer configuration shown in FIG. 3C (external bonding configuration 3).

(Comparative Example 1-1)
An infrared shielding film was produced in the same manner as Example 1-1 except that the layer containing tabular silver particles was not formed.

(Comparative Example 1-2)
An infrared shielding film was produced in the same manner as Comparative Example 1-1 except that the number of dielectric multilayer films was 200.

(Comparative Example 1-3)
An infrared shielding film was produced in the same manner as in Example 1-5 except that the layer containing tabular silver particles was not formed.

(Comparative Example 1-4)
An infrared shielding film was produced in the same manner as in Comparative Example 1-3, except that the number of dielectric multilayer films was 22 layers.

(Comparative Example 1-5)
An infrared shielding film was produced in the same manner as in Example 1-4 except that the dielectric laminated film was not formed.

(Comparative Example 1-6)
An infrared shielding film was produced in the same manner as in Comparative Example 1-5, except that the thickness of the layer containing tabular silver particles was 12 μm after drying.

(Comparative Example 1-7)
An infrared shielding film was produced in the same manner as in Comparative Example 1-5 except that the drying temperature was 100 ° C. in the above (formation of a layer containing tabular silver particles).

(Evaluation)
(Infrared reflectance)
The reflectance in the region of 850 to 1150 nm was measured using a spectrophotometer (integral sphere, manufactured by JASCO Corporation, model V-670) for the infrared shielding film attached to a 3 mm thick float plate glass. At the time of measurement, samples were placed so that light was incident from the glass surface except for Examples 1-13 and 1-14. In contrast, in the films of Examples 1-13 and 1-14, samples were placed so that light was incident from the side of the film attached to the glass. The measurement was performed 3 times, the average value was calculated | required, and it was set as the infrared reflectance.

(Solar radiation absorption rate)
The infrared absorption film affixed to a 3 mm-thick float plate glass was measured for solar absorptance according to JIS A5759: 2008 using a spectrophotometer (integral sphere, manufactured by JASCO Corporation, model V-670). At the time of measurement, samples were placed so that light was incident from the glass surface except for Examples 1-13 and 1-14. In contrast, in the films of Examples 1-13 and 1-14, samples were placed so that light was incident from the side of the film attached to the glass. The measurement was performed three times, and the average value was obtained as the solar radiation absorption rate.

(Haze value)
It measured according to JISK7136: 2000 using the haze meter (The Nippon Denshoku Industries Co., Ltd. make, NDH5000). A haze value of 1.5 or less is practical.

(Durability evaluation)
The infrared shielding film affixed to the 3 mm-thick float plate glass was left outdoors for one year. At that time, with respect to the incidence of sunlight, samples were placed so that sunlight was incident from the glass surface except for Examples 1-13 and 14. On the other hand, for the films of Examples 1-13 and 1-14, samples were placed so that sunlight was incident from the film side attached to the glass. Evaluation was made by calculating ΔE from the Lab value before and after being left standing with a spectrophotometer (using an integrating sphere, manufactured by JASCO Corporation, model V-670), and measuring the change in color. A ΔE of 0.5 or less is practical.

The structures and evaluation results of the infrared shielding films obtained in Examples 1-1 to 1-14 and Comparative Examples 1-1 to 1-7 are shown in Table 2 below.

As shown in Table 2 above, although the infrared shielding film of the present invention achieves high infrared reflectance and high transparency, problems such as discoloration are not observed even in long-term use.

In general, the higher the solar absorptivity, the greater the heat generation of the film. However, even a film having an infrared absorbing layer as in Examples 1-9 and 1-10 and having a higher solar absorptivity. , Discoloration over time is suppressed. This is because the layer containing tabular silver particles, which are discolored portions, and the infrared absorbing layer where heat generation occurs are separated via the base material, so the influence of heat generation on the layer containing tabular silver particles is small. Conceivable.

Example 2-1
[Production of infrared shielding film]
<Formation of a layer containing tabular silver particles>
(Preparation of coating solution containing flat silver particles)
Since this is the same as (preparation of flat silver particle-containing coating solution) in Example 1-1, description thereof is omitted here.

(Evaluation of tabular silver particles)
Since this is the same as (Evaluation of tabular silver particles) in Example 1-1, description thereof is omitted here.

(Formation of a layer containing tabular silver particles)
A solution obtained by diluting the tabular silver particle-containing coating solution obtained above with water so as to have an area ratio shown in Table 3 (for example, 12% in Example 2-1) was prepared. This solution was applied onto a 50 μm-thick polyethylene terephthalate (PET) film (Toyobo Co., Ltd., A4300: double-sided easy-adhesion layer) using a wire bar, and dried at a drying temperature of 70 ° C. for 2 minutes. A layer containing silver particles was formed. In addition, it apply | coated so that a dry film thickness might be 0.03 micrometer at this time. The amount of tabular silver particles applied was 20.4 mg / m ² .

(Evaluation of area ratio occupied by tabular silver particles)
In order to measure the area ratio of the film having a layer containing tabular silver particles produced as described above, the layer containing tabular silver particles was measured using a scanning electron microscope (S-5000, manufactured by Hitachi, Ltd.). The surface was observed. At this time, the magnification was observed at 30,000 times, and the obtained SEM image was binarized, and the area of the silver particle existing part and the non-existing part was calculated to obtain the actual area ratio. Furthermore, the measurement area ratio c was obtained at three places by changing the measurement location in the same procedure, and this average was taken as the area ratio C occupied by the tabular silver particles. As a result, the area ratio C was 12%.

Table 3 shows the area ratio C measured in the same procedure as described above for the following examples and comparative examples.

(Evaluation of orientation angle of tabular silver particles)
The prepared film having a layer containing tabular silver particles was embedded with an epoxy resin and then cleaved with a razor in a frozen state with liquid nitrogen to prepare a vertical section sample of the film. This vertical section sample was observed with a scanning electron microscope (SEM), and the inclination angle (absolute value) of the substrate with respect to the horizontal plane was calculated as an average value for 100 silver tabular grains. As a result, the orientation angle of the obtained tabular silver particles was in the range of 5 to 15 °.

<Formation of hard coat layer (HC layer)>
A hard coat layer coating solution (HC-1) was prepared in the same manner as in Example 1-1.

Next, the hard coat layer coating solution (HC-1) was applied to the laminate prepared above with a wire bar so as to have the layer structure shown in FIG. 3B, and dried with hot air at 70 ° C. for 3 minutes. Thereafter, in the atmosphere, a hard coat layer having a thickness of 3 μm was formed by curing at a curing condition of 400 mJ / cm ² using an ultraviolet curing apparatus (using a high-pressure mercury lamp) manufactured by I Graphics. The thickness of the hard coat layer was determined by observing the cross section of the hard coat layer with SEM.

<Dielectric multilayer film No. Production of 2-1>
Dielectric multilayer film No. 1 in Example 1-1 above. In the same manner as in 1-1, a laminate of polyethylene naphthalate (PEN: refractive index 1.65) and polymethyl methacrylate (PMMA: refractive index 1.40) is taken as one unit, and 120 units (a total of 240 layers) After being laminated, the film is stretched twice in length and twice in width, heat-set and cooled, so that the physical film thickness is 159 nm for the PEN layer and 190 nm for the PMMA layer. 2-1.

<Base material and dielectric multilayer film No. Bonding with 2-1>
The produced dielectric multilayer film No. 2-1 was bonded with a film having a layer containing the above-mentioned tabular silver particles by a bonding machine so as to have a layer structure as shown in FIG. 3B. That is, on the surface of the base material on the side where the layer containing tabular silver particles is not formed, the dielectric multilayer film No. 2-1 was pasted. At this time, the tension at the time of bonding on the PET base material side is 5 kg / m, the tension at the time of bonding on the dielectric multilayer film side is 5 kg / m, the nip roller temperature is 140 ° C., and the speed is 2 m / min. Through the process, a laminate was obtained.

<Formation of adhesive layer>
A pressure-sensitive adhesive coating solution was prepared in the same manner as in Example 1-1.

The pressure-sensitive adhesive layer employs a method in which a pressure-sensitive adhesive layer is applied to a separator film and then bonded to the laminate.

As the separator film, a 25 μm thick polyester film (Therapel (registered trademark): manufactured by Toyo Metallizing Co., Ltd.) was used. On the separator film, a pressure-sensitive adhesive coating solution was applied with a wire bar and dried at 80 ° C. for 2 minutes to prepare a film (adhesive layer-attached film) having an adhesive layer with a thickness of 20 μm. In addition, the thickness of the adhesion layer was calculated | required by observing the cross section of an adhesion layer by SEM.

And the adhesion layer surface of the film with an adhesion layer was bonded to the laminated body produced above by the bonding machine so that it might become the layer composition shown in Drawing 3B (configuration 2 for internal pasting, for internal pasting). At this time, the tension at the time of bonding on the laminated body side was set to 10 kg / m, and the tension at the time of bonding of the film with the adhesive layer was set to 30 kg / m.

As described above, an infrared shielding film was produced.

(Example 2-2)
Infrared shielding film in the same manner as in Example 2-1, except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 28.9 mg / m ^2. Was made. At this time, in the above (evaluation of the area ratio occupied by the tabular silver particles), the area ratio was 17%.

(Example 2-3)
Infrared shielding film in the same manner as in Example 2-1, except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 96.9 mg / m ^2. Was made. At this time, in the above (evaluation of the area ratio occupied by the tabular silver particles), the area ratio was 57%.

(Example 2-4)
Infrared shielding film in the same manner as in Example 2-1, except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 149.6 mg / m ^2. Was made. At this time, in the above (evaluation of the area ratio occupied by the tabular silver particles), the area ratio was 88%.

(Example 2-5)
Infrared shielding film in the same manner as in Example 2-1, except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 163.2 mg / m ^2. Was made. At this time, in the above (evaluation of the area ratio occupied by the tabular silver particles), the area ratio was 96%.

(Example 2-6)
In Example 2-1, the dielectric multilayer film No. Instead of 2-1, the following dielectric multilayer film No. An infrared shielding film was produced in the same manner as in Example 2-1, except that 2-2 was formed.

<Dielectric multilayer film No. Preparation of 2-2>
Dielectric multilayer film No. 1 in Example 1-5 above. In the same manner as in 1-2, the dielectric multilayer film No. 2-2 was produced.

(Example 2-7)
Infrared shielding film in the same manner as in Example 2-6 except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 28.9 mg / m ^2. Was made. At this time, the area ratio was 17% in the above (evaluation of the area ratio occupied by the tabular silver particles).

(Example 2-8)
An infrared shielding film was produced in the same manner as in Example 2-6 except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 68 mg / m ^2. did. At this time, the area ratio was 40% in the above (evaluation of the area ratio occupied by the tabular silver particles).

(Example 2-9)
Infrared shielding film in the same manner as in Example 2-6 except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 96.9 mg / m ^2. Was made. At this time, in the above (evaluation of area ratio occupied by flat silver particles), the area ratio was 57%.

(Example 2-10)
Infrared shielding film in the same manner as in Example 2-6 except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 132.6 mg / m ^2. Was made. At this time, in the above (evaluation of area ratio occupied by tabular silver particles), the area ratio was 78%.

(Example 2-11)
Infrared shielding film in the same manner as in Example 2-6 except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 149.6 mg / m ^2. Was made. At this time, in the above (evaluation of area ratio occupied by flat silver particles), the area ratio was 88%.

(Example 2-12)
Infrared shielding film in the same manner as in Example 2-6 except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 154.7 mg / m ^2. Was made. At this time, in the above (evaluation of the area ratio occupied by the tabular silver particles), the area ratio was 91%.

(Example 2-13)
Infrared shielding film in the same manner as in Example 2-6 except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 163.2 mg / m ^2. Was made. At this time, in the above (evaluation of area ratio occupied by tabular silver particles), the area ratio was 96%.

(Example 2-14)
In the above-described layered structure (outer pasting structure 4) as shown in FIG. 3D, and in the above (formation of a layer containing tabular silver particles), the amount of tabular silver particles is 96.9 mg / m. An infrared shielding film was produced in the same manner as in Example 2-1, except that it was ² . At this time, in the above (evaluation of area ratio occupied by flat silver particles), the area ratio was 57%.

(Example 2-15)
Infrared shielding film in the same manner as in Example 2-14 except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 149.6 mg / m ^2. Was made. At this time, in the above (evaluation of area ratio occupied by flat silver particles), the area ratio was 88%.

(Example 2-16)
In the above-described layered structure (outer pasting configuration 4, outer pasting) as shown in FIG. 3D, and in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles is 96. An infrared shielding film was produced in the same manner as in Example 2-6 except that it was 0.9 mg / m ² . At this time, the area ratio was 57%.

(Example 2-17)
Infrared shielding film in the same manner as in Example 2-16 except that in the above (formation of layer containing tabular silver particles), the amount of tabular silver particles was 132.6 mg / m ^2. Was made. At this time, the area ratio was 78%.

(Comparative Example 2-1)
An infrared shielding film was produced in the same manner as in Example 2-1, except that the layer containing tabular silver particles was not formed.

(Comparative Example 2-2)
An infrared shielding film was produced in the same manner as in Example 2-6 except that the layer containing tabular silver particles was not formed.

(Comparative Example 2-3)
The dielectric multilayer film and the layer containing the flat metal particles are not formed. Instead, as shown in FIG. 3E (layer structure 5), the metal reflective films are formed one by one through the substrate. In the same manner as in Example 2-1, an infrared shielding film was produced. The metal reflective film was formed as follows.

A polyethylene terephthalate (PET) film (Toyobo's A4300: double-sided easy-adhesion layer) of 30 cm × 30 cm size and 50 μm thickness is placed in a vacuum chamber of a vacuum deposition apparatus, and the room is 1.33 × 10 ⁻³ Pa (10 ⁻⁵ torr) Until the film temperature was maintained at 50 ° C. Two evaporation boards were installed in the vacuum chamber, and a silver bar and indium oxide powder were placed in each of them. First, indium oxide was heated to 1200 ° C., and an indium oxide film having a thickness of 350 Å was formed at a deposition rate of 10 Å / second. Next, the silver was heated to 1400 ° C. to form a 100 銀 silver film in the form of an indium oxide film at a rate of 20 Å / sec. Again, an indium oxide film with the same film thickness is formed, and again, a silver film with the same film thickness is formed again, and finally an indium oxide film with the same film thickness is formed. Thus, a metal reflection film was formed. Moreover, the same process was performed also on the back surface of PET base material, and the metal vapor deposition reflective film was formed in both surfaces.

(Evaluation)
(Shielding performance: shielding coefficient, thermal conductivity)
Using a spectrophotometer (integral sphere, manufactured by JASCO Corporation, Model V-670), the infrared shielding film attached to a 3 mm thick float plate glass was used to determine the shielding coefficient and thermal conductivity according to JIS A5759: 2008. It was measured. At the time of measurement, the sample was placed so that light was incident on the glass surface of each of the examples and comparative examples. The measurement was performed 3 times, the average value was calculated | required, and it was set as the shielding coefficient and the heat transmissivity, respectively.

(Adhesiveness)
The adhesiveness (adhesive strength) after water application was evaluated for the purpose of measuring the moisture dry state after water application. The infrared shielding films of the above Examples and Comparative Examples were cut to 250 × 25 mm and pasted on a float plate glass of 125 × 5 × 3 mm thickness so as to be in the form described in JIS A5759: 2008. However, at the time of pasting, the working liquid was sprayed and bonded to the glass surface and the surface of the film adhesive layer, and the roller described in JIS Z0237: 2009 was reciprocated 20 times on the film for pasting. The construction liquid is a liquid prepared by adding 2 g of neutral detergent Joy (registered trademark, manufactured by P & G) to 1000 g of water.

After pasting the film as described above, the film was stored in a refrigerator at 10 ° C., taken out with time, and subjected to a 180 ° peel test described in JIS A5759: 2008. When it was pasted without applying the construction liquid, the peeling force was 12 N / 25 mm (completely adhered state), but the time (days) until the completely adhered state was reached when the construction liquid was applied was measured. It is a practical range to reach a completely bonded state within 3 days.

(Anti-mold effect)
The infrared shielding film affixed to the 3 mm-thick float plate glass was left for 120 days in an environment of 25 ° C. and 80% RH. Discoloration of the film edge after standing was evaluated. This discoloration is discoloration (mold erosion) due to the generation of mold in the dielectric laminated film. If the mold erosion is less than 3 mm from the end of the film, it is at a level that does not cause a practical problem.

The structures and evaluation results of the infrared shielding films obtained in Examples 2-1 to 2-17 and Comparative Examples 2-1 to 2-3 are shown in Table 3 below.

As shown in Table 3 above, the infrared shielding film of the present invention has a short adhesion time of 3 days or less and a good adhesion. In addition, the infrared shielding film of the present invention has a shielding coefficient of 0.65 or less and a thermal conductivity of 5.0 or less, and has an excellent heat shielding effect and heat insulating effect. Furthermore, it can be said that the infrared shielding film of the present invention also has an antifungal effect because mold erosion is very small at less than 3 mm.

In particular, it can be said that Examples 2-9 and 2-10 have an excellent shielding effect because the shielding coefficient is less than 0.60 and the thermal conductivity is less than 4.0. Furthermore, in the infrared shielding films of these examples, the time required to be in a complete contact state was as short as 1 day, and since it was not eroded by mold, adhesion, heat shielding effect, heat insulation effect The antifungal effect was extremely excellent.

In addition, when Example 2-9 and Example 2-16 are compared, Example 2-9 has a smaller shielding coefficient and thermal conductivity, and Example 2-10 and Example 2-17 are compared. Then, since Example 2-10 has a smaller shielding coefficient and thermal conductivity, it can be said that a higher heat shielding effect and shielding effect can be obtained in the in-applied configuration 2, that is, the in-applied specification configuration. .

On the other hand, in the films of Example 2-1 and Example 2-6, those having an area ratio occupied by silver particles of less than 15% have a large shielding coefficient and heat transmissivity, and a relatively low heat shielding effect and heat insulation effect. It is shown that there is a tendency to become. Moreover, in the film in which the area ratio occupied by such silver particles is less than 15%, mold erosion is 3 mm or more, and it can be said that the mold prevention effect tends to be relatively low. Furthermore, as in Example 2-5 and Example 2-12, in which the area ratio occupied by the silver particles is 90% or more, the shielding coefficient and the heat transmissivity are sufficiently small, but until the complete contact state is achieved. It was shown that it takes a relatively long period of time.

Furthermore, this application is based on Japanese Patent Application No. 2012-086590 filed on April 5, 2012, and Japanese Patent Application No. 2012-086594 filed on the same date, Referenced and incorporated in its entirety.

1, 12 base material,
2, 13 Layers containing flat metal particles,
3 flat metal particles,
11 Hard coat layer,
14 Dielectric multilayer,
15 adhesive layer,
16 separator,
17 Metal reflective film.

Claims (11)

A substrate;
A dielectric multilayer film composed of a high refractive index layer and a low refractive index layer;
A layer containing tabular metal particles;
An infrared shielding film having: 2. The infrared shielding film according to claim 1, wherein the dielectric multilayer film is provided closer to a light incident side than a layer including the flat metal particles. The infrared shielding film according to claim 1 or 2, wherein the main plane of the flat metal particles is plane-oriented at an angle of 0 ° to ± 30 ° with respect to the surface of the substrate. The infrared shielding film according to any one of claims 1 to 3, wherein the layer containing the flat metal particles and the dielectric multilayer film are formed via the base material. The area ratio C represented by the following formula 1 is 15% or more and less than 90%, where A is the area of the substrate and B is the area occupied by the flat metal particles. The infrared shielding film of Claim 1.

A hard coat layer laminated on the layer containing the flat metal particles,
The infrared shielding film according to any one of claims 1 to 5, further comprising an adhesive layer laminated on the dielectric multilayer film. The infrared shielding film according to any one of claims 1 to 6, wherein the layer containing tabular metal particles includes tabular silver particles. The infrared shielding film according to any one of claims 1 to 7, wherein the high refractive index layer and the low refractive index layer contain metal oxide particles. The infrared shielding film according to any one of claims 1 to 8, wherein the dielectric multilayer film includes a water-soluble polymer. The infrared shielding film according to any one of claims 1 to 9, further comprising an infrared absorbing layer. An infrared shielding body comprising the infrared shielding film according to any one of claims 1 to 10 provided on at least one surface of a substrate.

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