JP2016090878A - Optical reflection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical reflection film that features a superior optical reflective property and includes an optical interference film having improved weatherability and water resistance.SOLUTION: An optical reflection film 1 includes optical interference films formed by alternately laminating high refractive index layers 15, comprising a first water-soluble polymer and first metal oxide particles, and low refractive index layers 14, comprising a second water-soluble polymer and second metal oxide particles, on a base material 11. At least one layer of the high refractive index layers 15 and low refractive index layers 14 constituting the optical interference films contains, as a binder, a photocrosslinked polymer compound, having inter-side-chain crosslinks, obtained by irradiating an active energy ray-crosslinkable polymer compound having a plurality of side chains on a hydrophilic main chain with active energy rays.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical reflection film. More specifically, the present invention relates to an optical reflective film that can be suitably used for a heat shielding film (near infrared light reflective film), a metallic glossy film, a visible light colored film, and the like.

  In recent years, interest in energy-saving measures has increased, and development of near-infrared light reflecting films (infrared shielding films) that are attached to the window glass of buildings and vehicles to block the transmission of solar heat rays (infrared rays) has become active. It has come to be. This is because the load on the cooling equipment can be reduced and is effective as an energy saving measure.

  As a method for shielding infrared rays, an optical interference film in which polymer layers (high refractive index layer and low refractive index layer) having different refractive indexes are alternately laminated on a base material is used as a near infrared light reflecting layer. The formed near-infrared light reflecting film is conventionally known and attracts attention as a simpler method. In addition, by adjusting the optical film thickness of the optical interference film in which the high refractive index layer and the low refractive index layer are alternately laminated, the optical reflection that reflects visible light, ultraviolet light, and far infrared light instead of near infrared light. It is also known that films can be designed. Further, Patent Document 1 uses an aqueous coating solution containing a water-soluble polymer functioning as a binder and metal oxide particles in at least one of the high refractive index layer and the low refractive index layer. It is described that an infrared reflective film can be obtained at a lower cost.

International Publication No. 2013/054912

  However, in the infrared reflective film described in Patent Document 1, the optical interference film formed by laminating the high-refractive index layer and the low-refractive index layer using a water-soluble polymer is used for a long time. There was a problem that peeling occurred between layers due to expansion.

  Therefore, in view of the above circumstances, an object of the present invention is to provide an optical reflection film that improves the weather resistance and water resistance of an optical interference film while maintaining excellent optical reflection characteristics.

  As a result of intensive studies to solve the above problems, the present inventor has obtained a photoreactive polymer compound having a plurality of side chains in the hydrophilic main chain as part or all of the water-soluble polymer in the coating solution. Is used to form a film in which high refractive index layers and low refractive index layers are alternately stacked. The film is irradiated with active energy rays to form a film (optical interference film) containing a photocrosslinking polymer compound crosslinked between the side chains. It has been found that the above-mentioned problems can be solved by adopting an optical reflection film configuration having an optical interference film containing such a photocrosslinking polymer compound.

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

1. A high refractive index layer containing a first water-soluble polymer and first metal oxide particles, and a low refractive index layer containing a second water-soluble polymer and second metal oxide particles on a substrate. In the optical reflection film having the optical interference film formed by alternately laminating,
At least one of the high refractive index layer and the low refractive index layer constituting the optical interference film is a polymer compound (also referred to as a photoreactive polymer compound) that is cross-linked by active energy rays, and has a hydrophilic main chain. An optical reflection comprising a photoreactive polymer compound having a plurality of side chains as a binder, which is obtained by irradiating active energy rays with a photocrosslinked polymer compound crosslinked between side chains. the film.

  2. The partial structure of the hydrophilic main chain and side chain of the photoreactive polymer compound has the following general formula (A)

[In the formula, Poly represents a hydrophilic main chain, {} represents a side chain, X ₁ represents a (p + 1) -valent linking group, B represents a crosslinkable group, and Y ₁ represents a hydrogen atom or a substituted group. Represents a group. m represents 0 or 1, n represents 0 or 1, and p represents a positive integer. When p is 2 or more, a plurality of B and Y ₁ may be the same or different. 2. The optical reflective film as described in 1 above, wherein

  3. The above 1 or 2, wherein the hydrophilic main chain of the photoreactive polymer compound is a saponified product of polyvinyl acetate, the saponification degree is in the range of 77 to 99%, and the polymerization degree is in the range of 500 to 5000. 2. The optical reflection film according to 2.

  4). The modification of the side chain with respect to the hydrophilic main chain of the photoreactive polymer compound is in a range of 0.7 to 4.5 mol%, according to any one of the above 1 to 3, Optical reflective film.

  5. 5. An optical reflector formed by providing the optical reflective film according to any one of 1 to 4 on at least one surface of a substrate.

  In the present invention, it is possible to provide an optical reflective film excellent in the weather resistance and water resistance of an optical interference film while maintaining excellent optical reflection characteristics.

It is a schematic sectional drawing which shows the general structure of one Embodiment of the optical reflection film of this invention. It is a schematic sectional drawing which shows the general structure of other embodiment of the optical reflection film of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the technical scope of the present invention should be determined based on the description of the scope of claims, and is not limited to the following embodiments.

The optical reflective film according to the first embodiment of the present invention includes a high refractive index layer containing a first water-soluble polymer and first metal oxide particles, a second water-soluble polymer, and a substrate. In an optical reflective film having an optical interference film formed by alternately laminating low refractive index layers containing second metal oxide particles,
At least one of the high refractive index layer and the low refractive index layer constituting the optical interference film is a polymer compound (hereinafter also referred to as a photoreactive polymer compound) that is cross-linked by active energy rays, and has a hydrophilic main property. The polymer compound having a plurality of side chains in the chain contains, as a binder, a photocrosslinkable polymer compound that is obtained by irradiating active energy rays and crosslinked between side chains. is there. With the above configuration, the effects of the present invention can be effectively exhibited.

  That is, although this inventor tried the improvement by a crosslinking agent as one means to improve the problem of patent document 1, it turned out that there exist the following subjects. That is, when forming the optical interference film (reflective layer), an attempt was made to improve the durability of the film (improvement to make it difficult to break the film in a weather resistance test) by adding a crosslinking agent to the coating solution and crosslinking. However, cross-linking with a cross-linking agent is a well-known technique, but the reaction starts after the addition and causes gelation and aggregation of the liquid, leading to coating failure, failing to obtain a good film, and thus not solving the above problem. all right. For this reason, it is necessary to install a large amount of a crosslinking agent having low reactivity or to mix with the coating solution immediately before coating, and the mixing property (uniform mixing) of the coating solution and the crosslinking agent depends on the respective liquid properties and equipment conditions. It was found that a difficult, homogeneous and good film could not be obtained, and that the above problem could not be solved. In view of these problems, the present inventors have further studied earnestly, and as a result, have found means that can solve these problems. That is, as part or all of the water-soluble polymer that functions as a binder in the coating solution, a photoreactive (active energy ray crosslinkable) polymer compound such as polyvinyl alcohol having a plurality of side chains in the hydrophilic main chain is used. The film is formed by alternately laminating a high refractive index layer and a low refractive index layer. Thereafter, this film is irradiated with active energy rays such as ultraviolet rays, and a film containing a photocrosslinkable polymer compound crosslinked between side chains of adjacent photoreactive polymer compounds (mutually) (optical interference film) Form. By adopting an optical reflective film configuration having an optical interference film containing such a photocrosslinkable polymer compound as a binder, the above problems do not occur, and the weather resistance and water resistance of the optical interference film can be improved. Further, a part of or all of the water-soluble polymer functioning as the binder is formed by using a UV reactive (UV crosslinkable) polymer compound among the photoreactive (active energy ray crosslinkable). Later, when a hard coat layer made of UV curable resin is combined on the laminated film or on the opposite side of the substrate, UV irradiation when applying the coating liquid for the hard coat layer should be used. Can do. Therefore, it is not necessary to newly add equipment such as a UV irradiation device or newly provide a UV irradiation stage (process) in the optical interference film coating formation process, and the process load can be reduced.

  In this specification, a refractive index layer having a higher refractive index than the other is referred to as a high refractive index layer, and a refractive index layer having a lower refractive index than the other is referred to as a low refractive index layer. In this specification, the terms “high refractive index layer” and “low refractive index layer” refer to a refractive index layer having a higher refractive index when comparing the refractive index difference between two adjacent layers. It means that the lower refractive index layer is a low 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.

  Hereinafter, the components of the optical reflecting film of the present invention will be described in detail. Hereinafter, when the low refractive index layer and the high refractive index layer are not distinguished, the concept including both is referred to as a “refractive index layer”.

  In this specification, “X to Y” indicating a range means “X or more and Y or less”. Unless otherwise specified, measurement of operation and physical properties is performed under conditions of room temperature (20 to 25 ° C.) / Relative humidity 40 to 50%.

{Optical reflection film}
The optical reflective film of the present invention includes a base material and an optical interference film formed by alternately laminating a high refractive index layer and a low refractive index layer.

  The optical reflective film of the present invention is not particularly limited as long as it has a multilayer optical interference film formed by alternately laminating a high refractive index layer and a low refractive index layer on one side or both sides of a substrate. . From the viewpoint of productivity, the preferred range of the total number of high refractive index layers and low refractive index layers per one side of the substrate is 100 layers or less, 12 layers or more, more preferably 45 layers or less, 15 layers or more, more preferably 45 layers or less, 21 layers or more. The preferred range of the total number of high refractive index layers and low refractive index layers is applicable even when laminated on only one side of the substrate, and when laminated simultaneously on both sides of the substrate. Is also applicable. When laminated on both surfaces of the substrate, the total number of high refractive index layers and low refractive index layers on one surface of the substrate and the other surface may be the same or different.

  In the optical reflective film of the present invention, the lowermost layer and the uppermost layer (outermost layer) may be either a high refractive index layer or a low refractive index layer. Preferably, the low refractive index layer has a layer configuration located in the lowermost layer and the uppermost layer. By adopting such a layer configuration, the adhesion to the lowermost base material and the undercoat layer, the blowing resistance of the uppermost layer, and further preferable in terms of excellent applicability and adhesion such as a hard coat layer to the uppermost layer. .

  Hereinafter, the general structure of the optical reflective film of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios.

  FIG. 1 is a schematic cross-sectional view showing a general configuration of an embodiment of the optical reflection film of the present invention. The optical reflective film 1 shown in FIG. 1 has a base material 11, an undercoat layer 12 formed on one side of the base material 11 (a surface on which sunlight L is inserted), and the other surface of the base material 11 ( And the optical interference films 13 a and 13 b formed on the undercoat layer 12. In FIG. 1, m low refractive index layers 14, m−1 high refractive index layers 15, and low refractive index layers 14 are disposed in the lowermost and uppermost layers of the optical interference films 13 a and 13 b. The optical interference films 13 a and 13 b are alternately formed on both surfaces of the substrate 11. Here, m is an integer of 2 or more, and FIG. 1 represents an example of m = 5. Further, a transparent hard coat layer (CHC layer) 16 is formed on the uppermost low refractive index layer 14 of the optical interference film 13b on one side of the substrate 11 (the surface on the indoor side opposite to the side where the sunlight L is inserted). Are combined (formed).

  FIG. 2 is a schematic cross-sectional view showing a general configuration of another embodiment of the optical reflecting film of the present invention. 2 is formed on the base layer 11, the undercoat layer 12 formed on one side of the base material 11 (the surface on which sunlight L is inserted), and the undercoat layer 12. The optical interference film 13a is provided. In FIG. 2, the optical interference film 13a in which a laminated film (interference film) having the same configuration as that of FIG. 1 is formed so that the low refractive index layer 14 is disposed in the lowermost layer and the uppermost layer of the optical interference film 13a is a substrate. 11 is formed on one side. Further, a transparent hard coat layer (CHC layer) 16 is combined (formed) on one side of the substrate 11 (the surface on the indoor side opposite to the side on which the sunlight L is inserted).

  In the configuration example of FIGS. 1 and 2, the optical interference film 13a on one side of the base material 11 (the surface on which sunlight L is inserted; the surface that is attached to the base 18 such as an automobile window or a glass window of a building) A transparent adhesive layer 17 is formed on the upper low refractive index layer 14.

  Further, in the configuration example of FIGS. 1 and 2, the optical reflection films 1 and 1 ′ may be pasted on the indoor (inside or inside) side of the base 18 such as an automobile window or a glass window of a building. 1 and 2 show a state after the optical reflection films 1 and 1 ′ are attached to the base 18. 1 and 2 show an example in which the undercoat layer 12 is formed on one surface of the base material 11 (the surface on which sunlight L is inserted), but the undercoat layer 12 is formed on both surfaces of the base material 11. Alternatively, the optical interference films 13 a and 13 b may be formed directly on the substrate 11 without forming the undercoat layer 12. Moreover, depending on the usage pattern, the CHC layer 16 and the transparent adhesive layer 17 are not necessarily required, and a configuration in which these layers are not provided may be employed. Further, a release layer (not shown) may be provided on the transparent adhesive layer 17, and this release layer may be peeled off when being attached to the substrate 18. Similarly, a release layer (not shown) may be provided on the CHC layer 16, and the release layer may be peeled off after being attached to the substrate 18.

  The optical reflecting film of the present invention is not limited to the configuration examples of FIGS. 1 and 2, and is one side of the substrate (for example, the surface on the side opposite to the side where sunlight L is inserted) or the other side. Addition of additional functions to one surface side (for example, the surface into which sunlight L is inserted; the surface attached to the base 18 such as an automobile window or a glass window of a building), an intermediate layer, or an outermost layer For the purpose, not only the CHC layer 16 and the transparent adhesive layer 17 but also various functional layers such as a conductive layer, an antistatic layer, a gas barrier layer, an easy adhesion layer, an antifouling layer, a deodorizing layer, a droplet layer, Sliding layer, abrasion resistant layer, antireflection layer, electromagnetic wave shielding layer, ultraviolet absorbing layer, infrared absorbing layer, printing layer, fluorescent light emitting layer, hologram layer, release layer, adhesive layer, adhesive layer, high refractive index layer of the present invention And a cut layer (metal layer, liquid crystal layer) in a specific wavelength region other than the low refractive index layer Colored layer (visible light absorbing layer), one or more functional layers such as an intermediate layer may be used singly or appropriately utilized in laminated glass.

  In general, in an optical reflection film, designing a large difference in refractive index between a high refractive index layer and a low refractive index layer increases the reflectance (for example, near infrared reflectance) for a specific wavelength region with a small number of layers. From the viewpoint of being able to do. In 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, more preferably 0.25 or more, still more preferably 0.3 or more, and even more. Preferably it is 0.35 or more, and most preferably 0.4 or more.

  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 difference in refractive index, the same reflectance is obtained with fewer layers. It is done. The refractive index difference and the required number of layers can be calculated using commercially available optical design software. As a reflectance for a specific wavelength region, for example, in order to obtain a near-infrared reflectance of 90% or more, if the refractive index difference is smaller than 0.1, it is necessary to stack 200 layers or more, which only reduces productivity. In addition, scattering at the lamination interface increases, transparency is lowered, and it may be very difficult to manufacture without failure. From the standpoint of improving reflectivity and reducing the number of layers, there is no upper limit to the difference in refractive index, but practically about 1.4 is the limit.

  When the optical reflective film is formed by alternately laminating a high refractive index layer and a low refractive index layer, the refractive index difference between the high refractive index layer and the low refractive index layer is within the range of the preferred refractive index difference. Is preferred. However, for example, when the outermost layer is formed as a layer for protecting the film or when the lowermost layer is formed as an adhesion improving layer with the substrate, the above-mentioned preferable refraction is performed with respect to the outermost layer and the lowermost layer. A configuration outside the range of the rate difference may be used.

  Furthermore, as the optical characteristics of the optical reflecting film of the present invention, it is desirable that the haze value is improved, the degree of haze is low, and the transparency is increased. Therefore, the transmittance in the visible light region shown in JIS R3106-1998 is desirable. Is 50% or more, preferably 75% or more, and more preferably 85% or more. In addition, since it is desirable that the optical reflection film can maintain the optical reflection characteristics, for example, in the case of an infrared shielding film, it is preferable that the specific wavelength region has a region with a reflectance exceeding 50% in a wavelength region of 900 nm to 1400 nm. By reflecting the near-infrared wavelength region having a wavelength of 900 nm to 1400 nm, transmission of infrared rays (heat rays) can be blocked, and heat can be prevented. As for the optical reflection characteristics of the optical reflection film, it is desirable that the reflectance in a specific wavelength region to be reflected exceeds 50%, depending on the use application. The transmittance in the visible light region can be measured according to JIS R3106-1998. Specifically, in addition to the visible light transmittance of an infrared shielding film (sample) using a commercially available spectrophotometer (for example, using an integrating sphere, manufactured by Hitachi, Ltd., U-4000 type), infrared transmittance and infrared reflectance In addition, the reflectance in a specific wavelength region can be measured.

  The total thickness of the optical reflective 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. Further, the thickness per layer of the low refractive index layer is preferably 20 to 800 nm, and more preferably 50 to 350 nm. The total thickness of the optical reflection film can be obtained by measuring the cut surface of the optical reflection film with a scanning electron microscope (SEM).

  Next, components included in each element will be described in detail in order with respect to the high refractive index layer, the low refractive index layer, and the base material, which are constituent elements of the optical reflective film of the present invention.

<High refractive index layer>
The high refractive index layer according to the present invention contains the first water-soluble polymer and the first metal oxide particles as essential components, and if necessary, includes a curing agent, a surface coating component, a surfactant, and various additives. It may further include at least one selected from the group consisting of:

  The refractive index of the high refractive index layer according to the present invention is preferably 1.80 to 2.50, more preferably 1.90 to 2.20. The refractive index can be measured by the following single film refractive index measurement method. The same applies to the measurement of the refractive index of the low refractive index layer. The difference in refractive index between the adjacent high refractive index layer and low refractive index layer can also be calculated from the measurement results of the refractive indexes of the high refractive index layer and the low refractive index layer.

(Measurement of single film refractive index of each layer)
Samples are prepared by coating the target layers (high refractive index layer and low refractive index layer) whose refractive index is measured on the base material as single layers, and according to the following method, each of the high refractive index layer and the low refractive index layer Find the refractive index of.

  Using a U-4000 type (manufactured by Hitachi, Ltd.) as a spectrophotometer, the back side on the measurement side of each sample is roughened, and then light absorption is performed with a black spray to reflect light on the back side. The refractive index can be obtained from the measurement result of the reflectance in the visible light region (400 nm to 700 nm) under the condition of regular reflection at 5 degrees.

  The thickness per layer of the high refractive index layer according to the present invention is preferably 20 to 800 nm, and more preferably 50 to 350 nm. The thickness per layer of the high refractive index layer can be determined by measuring the cut surface of the optical reflection film with a scanning electron microscope (SEM).

  Here, when measuring the thickness per layer, the high refractive index layer and the low refractive index layer may have a clear interface between them or may be gradually changed. When the interface is gradually changing, the maximum refractive index-minimum refractive index = Δn in the region where the layers are mixed and the refractive index continuously changes, the minimum refractive index between two layers + Δn The point of / 2 is regarded as the layer interface. The same applies to the layer thickness of the low refractive index layer described later.

  The metal oxide concentration profile of the laminated film, which is an optical interference film formed by alternately laminating the high refractive index layer and the low refractive index layer of the present invention, is etched from the surface to the depth direction using the sputtering method. It can be seen by using an XPS surface analyzer, setting the outermost surface to 0 nm, sputtering at a rate of 0.5 nm / min, and measuring the atomic composition ratio. It is also possible to view the cut surface by cutting the laminated film and measuring the atomic composition ratio with an XPS surface analyzer. When the concentration of the metal oxide changes discontinuously in the mixed region, the boundary can be found by a tomographic photograph using an electron microscope (TEM).

  There is no particular limitation on the XPS surface analyzer, and any model can be used, but ESCALAB-200R manufactured by VG Scientific Fix Co. was used. Mg is used for the X-ray anode, and measurement is performed at an output of 600 W (acceleration voltage: 15 kV, emission current: 40 mA).

"First metal oxide particles"
The high refractive index layer of the present invention contains the first metal oxide particles. The first metal oxide particles that can be included in the high refractive index layer are metal oxide particles that are different from the second metal oxide particles included in the low refractive index layer from the viewpoint of different refractive indexes. preferable. In the case where a plurality of high refractive index layers are provided, the first metal oxide particles are included in all of the plurality of high refractive index layers.

  Examples of the first metal oxide particles used in the high refractive index layer according to the present invention include, for example, titanium oxide particles, zirconium oxide particles, zinc oxide particles, synthetic amorphous silica force particles, narrow mouth force particle, alumina Particles, colloidal alumina particles, lead titanate particles, red lead particles, yellow lead particles, zinc yellow particles, chromium oxide particles, ferric oxide particles, iron black particles, oxidized steel particles, magnesium oxide particles, magnesium hydroxide particles, Examples include strontium titanate particles, yttrium oxide particles, niobium oxide particles, europium oxide particles, lanthanum oxide particles, zircon particles, and tin oxide particles. In the present invention, in order to adjust the refractive index, the first metal oxide particles may be used alone or in combination of two or more.

  In the present invention, in order to form a transparent and higher refractive index layer having a higher refractive index, the high refractive index layer is a first metal oxide particle having a high refractive index, such as titanium or zirconia, that is, titanium oxide particles. It is preferable to contain zirconia oxide particles. In addition, containing rutile (tetragonal) titanium oxide particles having a volume average particle size of 100 nm or less is easier to reduce the particle size than the anatase type, and reacts by a photocatalytic action as in the anatase type and has a high refractive index. It is more preferable from the viewpoint that the layer is not colored. A plurality of types of titanium oxide particles may be mixed.

  In addition, the second metal oxide particles contained in the low refractive index layer and the first metal oxide particles contained in the high refractive index layer are in a state of having ionicity (that is, the electric charges have the same sign). It is preferable. For example, in the case of simultaneous multi-layer coating, if the ionicity is different, it reacts at the interface to form an aggregate and haze (transparency) is deteriorated. As means for aligning ionicity, for example, silicon dioxide (anion) was used for the second metal oxide particles of the low refractive index layer, and titanium oxide (cation) was used for the first metal oxide particles of the high refractive index layer. In some cases, silicon dioxide can be treated with aluminum or the like to be cationized, or, as described later, titanium oxide can be treated with silicon-containing hydrated oxide to be anionized.

  The average particle diameter (number average) of the first metal oxide particles contained in the high refractive index layer of the present invention is preferably 3 to 100 nm, and more preferably 3 to 50 nm.

  The first metal oxide particles contained in the high refractive index layer preferably have a volume average particle size of 50 nm or less, more preferably 1 to 45 nm, and further preferably 5 to 40 nm. preferable. A volume average particle size of 50 nm or less is preferable from the viewpoint of low visible light transmittance and low haze.

  The volume average particle size here is a volume average particle size 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, by observing particles themselves using a laser diffraction scattering method, dynamic light scattering method or electron microscope, or by observing particle images appearing on the cross section or surface of the refractive index layer with an electron microscope. , 1,000 arbitrary particles are measured, and there are n1, n2,..., Ni, nk particles each having a particle size of d1, d2,. In a group of metal oxide particles (particulate metal oxide), where the volume per particle is vi, the volume average particle diameter mv = {Σ (vi · di)} / {Σ (vi)} The average particle diameter weighted by the volume represented by is calculated. The volume average particle size measurement and calculation method described above can be applied to both the first metal oxide particles contained in the high refractive index layer and the second metal oxide particles contained in the low refractive index layer. Is.

  Furthermore, the metal oxide particles used in the present invention are preferably monodispersed. This is because, in polydispersion, large particle diameters are mixed and haze increases (thickness uniformity and transparency decrease). The monodispersion here means that the monodispersity obtained by the following formula is 40% or less. This monodispersity is more preferably 30% or less, and particularly preferably 0.1 to 20%. The average value of the particles in the following monodispersity formula refers to the volume average value of the particles. The monodispersion and monodispersity described above can be applied to both the first metal oxide particles contained in the high refractive index layer and the second metal oxide particles contained in the low refractive index layer. It is.

  As content of the 1st metal oxide particle in the high refractive index layer which concerns on this invention, it is preferable that it is 15-95 mass% with respect to 100 mass% of total solids of a high refractive index layer, and is 20-20. More preferably, it is 88 mass%, and it is further more preferable that it is 30-85 mass%. When the content of the first metal oxide particles is within the above range, it is preferable from the viewpoint that the refractive index difference from the low refractive index layer can be increased. Further, by setting the content of the first metal oxide particles within the above range, the optical reflection (shielding) property in a desired wavelength (light ray) region such as infrared ray (heat ray) shielding property (reflective property) is good. I can do it.

  The titanium oxide particles preferably used as the first metal oxide particles of the present invention are preferably those obtained by modifying the surface of the titanium oxide sol so that it can be dispersed in water or an organic solvent.

  Examples of the preparation method of the aqueous titanium oxide sol include, for example, JP-A-63-17221, JP-A-7-819, JP-A-9-165218, JP-A-11-43327, JP-A-63-3. Reference can be made to the matters described in Japanese Patent No. 17221.

  When titanium oxide particles are used as the first metal oxide particles, other methods for producing titanium oxide particles include, for example, “Titanium oxide—physical properties and applied technology” Manabu Seino p255-258 (2000) Gihodo Publishing Co., Ltd. Alternatively, the method of step (2) described in paragraph numbers 0011 to 0023 of WO2007 / 039953 can be referred to.

  In the production method according to the above step (2), titanium dioxide hydrate is treated with at least one basic compound selected from the group consisting of alkali metal hydroxides or alkaline earth metal hydroxides. After the step (1), the titanium dioxide dispersion obtained comprises a step (2) of treating with a carboxylic acid group-containing compound and an inorganic acid.

  The first metal oxide particles of the present invention are preferably in the form of core-shell particles in which titanium oxide particles are coated with a silicon-containing hydrated oxide. This is because the titanium oxide particles coated with the silicon-containing hydrated oxide are contained in the high refractive index layer, so that the interaction between the silicon-containing hydrated oxide and the first water-soluble polymer increases. Effect of suppressing interlayer mixing between refractive index layer and low refractive index layer, and deterioration or choking of water-soluble polymer due to photocatalytic activity of titanium oxide when using not only rutile type titanium oxide particles but also anatase type titanium oxide particles There is an effect that problems such as can be prevented. When the titanium oxide particles coated with the silicon-containing hydrated oxide and the other first metal oxide particles are used in combination, the titanium oxide particles coated with the silicon-containing hydrated oxide are electrically charged. Various ionic dispersants and protective agents can be used so as not to aggregate.

Here, “titanium oxide particles” mean titanium dioxide (TiO ₂ ) particles. The term “coating” means a state in which a silicon-containing hydrated oxide is attached to at least a part of the surface of the titanium oxide particles. That is, the surface of the titanium oxide particles used as the first metal oxide particles according to the present invention may be completely covered with a silicon-containing hydrated oxide, and a part of the surface of the titanium oxide particles may be covered. It may be coated with a silicon-containing hydrated oxide. From the viewpoint that the refractive index of the coated titanium oxide particles is controlled by the coating amount of the silicon-containing hydrated oxide, a part of the surface of the titanium oxide particles may be coated with the silicon-containing hydrated oxide. preferable.

  In the present invention, the first metal oxide particles may be rutile type titanium oxide particles coated with silicon-containing hydrated oxide, or anatase type coated with silicon-containing hydrated oxide. These may be titanium oxide particles, or a mixed particle thereof. Among these, rutile type titanium oxide particles coated with silicon-containing hydrated oxide are more preferable.

  This is because the rutile type titanium oxide particles have lower photocatalytic activity than the anatase type titanium oxide particles, and therefore the weather resistance of the high refractive index layer and the adjacent low refractive index layer is increased, and the refractive index is further increased. Because.

  The aqueous solution containing titanium oxide particles used for the first metal oxide particles according to the present invention has a pH of 1.0 to 3.0 and the surface of an aqueous titanium oxide sol having a positive zeta potential of the titanium particles. Can be made hydrophobic and dispersible in an organic solvent.

  In the present specification, the “silicon-containing hydrated oxide” may be any of a hydrate of an inorganic silicon compound, a hydrolyzate and / or a condensate of an organosilicon compound, and in order to obtain the effects of the present invention. It is more preferable to have a silanol group. Therefore, in the present invention, the first metal oxide particles are preferably silica-modified (silanol-modified) titanium oxide particles in which the titanium oxide particles are silica-modified.

The coating amount of the silicon-containing hydrated compound of titanium oxide is 3 to 30% by mass, preferably 3 to 10% by mass, more preferably 3 to 8% by mass as SiO _{2 with} respect to 100% by mass of titanium oxide. . When the coating amount is 30% by mass or less, it is easy to increase the refractive index of the high refractive index layer, and when the coating amount is 3% by mass or more, the coated particles can be stably formed. .

  The particle diameter of the titanium oxide particles and the titanium oxide particles (core-shell particles; first metal oxide particles) coated with the titanium oxide particles and the silicon-containing hydrated oxide is determined by the volume average particle diameter or the primary average particle diameter. Can do. As the core-shell particles, the volume average particle size of the titanium oxide particles as the core portion is preferably 30 nm or less, more preferably 1 to 30 nm, still more preferably 5 to 15 nm, and most preferably 6 to 10 nm. A shell made of silicon-containing hydrated oxide is used so that the coating amount of silicon-containing hydrated oxide is 3 to 30% by mass as SiO2 with respect to 100% by mass of titanium oxide as a core on the particle surface. It is a structure formed by coating. If the volume average particle diameter of the titanium oxide particles as the core portion is 1 to 30 nm, it is preferable from the viewpoint of low haze and excellent visible light transmittance. Further, in the present invention, by including core-shell particles as the first metal oxide particles, a silicon-containing hydrated oxide of the shell layer and a binder resin (first water-soluble compound containing a photoreactive polymer compound). Due to the interaction with the polymer), the intermixing of the high refractive index layer and the low refractive index layer is suppressed.

  The volume average particle diameter of the titanium oxide particles (core-shell particles; first metal oxide particles) coated with the silicon-containing hydrated oxide is preferably 2 to 31 nm, more preferably 6 to 16 nm. Yes, more preferably 7 to 11 nm. When the volume average particle size of the titanium oxide particles (core-shell particles; first metal oxide particles) coated with the silicon-containing hydrated oxide is 2 to 31 nm, near-infrared (heat ray) shielding properties (reflectivity) Etc.) from the viewpoint of optical properties such as optical reflection (shielding) in a desired wavelength (light ray) region, transparency, and haze.

  The primary average particle size of the titanium oxide particles (core particles) used for the core-shell particles (first metal oxide particles) and not coated with the silicon-containing hydrated oxide is preferably 30 nm or less. It is more preferably ˜30 nm, further preferably 1 to 20 nm, and most preferably 1 to 10 nm. A primary average particle diameter of 1 nm or more and 30 nm or less is preferable from the viewpoint of low haze and excellent visible light transmittance.

  The primary average particle diameter of titanium oxide particles (core-shell particles; first metal oxide particles) coated with a silicon-containing hydrated oxide is preferably 2 to 31 nm, more preferably 2 to 21 nm. More preferably, it is 2-11 nm. When the primary average particle diameter of the core-shell particles (first metal oxide particles) is 2 to 31 nm, optical reflection (shielding) in a desired wavelength (light ray) region such as near infrared (heat ray) shielding (reflection) From the viewpoints of optical properties such as property, transparency, and haze.

  In addition, the primary average particle diameter in this specification can be measured from the electron micrograph by a transmission electron microscope (TEM) etc. You may measure by the particle size distribution meter etc. which utilize a dynamic light scattering method, a static light scattering method, etc.

  When obtained from a transmission electron microscope, the primary average particle diameter of the particles is observed with an electron microscope on the particles themselves or the cross section or surface of the refractive index layer, and the particle diameter of 1000 arbitrary particles is measured. It is obtained as its simple average value (number average). Here, the particle diameter of each particle is represented by a diameter assuming a circle equal to the projected area.

  As a method for producing the first metal oxide particles according to the present invention, a known method can be employed. For example, when the core-shell particles are used as the first metal oxide particles, the following (i) ) To (v).

  (I) An aqueous solution containing titanium oxide particles is hydrolyzed by heating, or an alkali is added to the aqueous solution containing titanium oxide particles and neutralized to obtain titanium oxide having an average particle size of 1 to 30 nm. The slurry in which the titanium oxide particles and the mineral acid are mixed so that the ratio of titanium oxide particles / mineral acid is in the range of 1 / 0.5 to 1/2 in terms of the ratio is 50 ° C. or more and the boiling point of the slurry or less. Heat treatment is performed at a temperature, and then a silicon compound (for example, sodium silicate aqueous solution) is added to the resulting slurry containing titanium oxide particles to precipitate silicon hydrated oxide on the surface of the titanium oxide particles. Then, impurities are removed from the resulting slurry of the surface-treated titanium oxide particles (method described in JP-A-10-158015).

  (Ii) A titanium oxide sol stabilized at pH in the acidic range obtained by peptizing a titanium oxide such as hydrous titanium oxide with a monobasic acid or a salt thereof, and an alkyl silicate as a dispersion stabilizer are mixed by a conventional method. And neutralization method (method described in JP 2000-053421 A).

(Iii) Hydrogen peroxide and metallic tin are added to a mixture aqueous solution such as titanium salt (eg, titanium tetrachloride) simultaneously or alternately while maintaining a H ₂ O ₂ / Sn molar ratio of _{2 to} 3, A basic salt aqueous solution is formed, and the basic salt aqueous solution is held at a temperature of 50 to 100 ° C. for 0.1 to 100 hours to form a composite colloidal aggregate containing titanium oxide; The electrolyte in the aggregate slurry is removed, and a stable aqueous sol of composite colloidal particles containing titanium oxide is produced. On the other hand, a stable aqueous sol of composite colloidal particles containing silicon dioxide is produced by preparing an aqueous solution containing silicate (eg, sodium silicate aqueous solution) and removing cations present in the aqueous solution. Is done. Composite aqueous sol containing the resulting titanium oxide in terms 100 parts by mass in terms of metal oxides TiO _2, composite aqueous sol containing silicon dioxide resulting in a metal oxide SiO ₂ 2 to 100 A method of mixing with parts by mass and removing anions, followed by heating and aging at 80 ° C. for 1 hour (method described in JP-A No. 2000-063119).

  (Iv) Hydrogen peroxide is added to hydrous titanic acid gel or sol to dissolve hydrous titanic acid, and the resulting peroxotitanic acid aqueous solution is heated by adding a silicon compound or the like to form a rutile structure. A core particle dispersion is obtained, and then a silicon compound or the like is added to the core particle dispersion, followed by heating to form a coating layer on the surface of the core particles, and the composite oxide particles dispersed in the sol And a method of heating (the method described in JP 2000-204301 A).

(V) A hydrosol of titanium oxide obtained by peptizing hydrous titanium oxide from organoalkoxysilane (R ¹ _n SiX _4-n ) or hydrogen peroxide and aliphatic or aromatic hydroxycarboxylic acid as a stabilizer. Examples thereof include core-shell particles produced by a method of adding a selected compound, adjusting the pH of the solution to 3 or more and less than 9 and aging, followed by desalting (a method described in Japanese Patent No. 4550753).

By the methods (i) to (v), the first metal oxide particles (particularly titanium oxide particles coated with a silicon-containing hydrated oxide) according to the present invention can be produced. To adjust the coating amount of the titanium oxide particles as the first metal oxide particles with the silicon-containing hydrated oxide, for example, (1) Titanium oxide used in the above methods (i) and (iv) A method of adjusting a coating amount of a silicon-containing hydrated oxide by adjusting an amount of a silicon compound added to particles; (2) a composite aqueous sol containing titanium oxide obtained in the method (iii); The composite aqueous sol containing silicon dioxide and silicon dioxide is converted into the metal oxides TiO ₂ and SiO ₂ , respectively, and by adjusting the amount of the corresponding SiO ₂ with respect to the corresponding TiO ₂ , Method for adjusting the coating amount; (3) In the above method (v), the coating amount of the silicon-containing hydrated oxide is adjusted by adjusting the amount of the organoalkoxysilane used. (4) In the above method (ii), there may be mentioned a method of adjusting the amount of addition of the alkyl silicate koji.

  When preparing the first metal oxide particles (particularly titanium oxide particles coated with a silicon-containing hydrated oxide) according to the present invention, the first metal oxide particles (silicon-containing hydrated oxide) In the suspension containing the coated titanium oxide particles), the preferable solid content of the first metal oxide particles is 1 to 40% by mass with respect to 100% by mass of the solid content of the entire suspension. The solid content is more preferably 15 to 25% by mass. This is because the solid content is 1% by mass or more, the solid content concentration is increased, the solvent volatilization load can be reduced and the productivity can be improved, and the solid content is 40% by mass or less. This is because aggregation due to high particle density can be prevented and defects during coating can be reduced. When preparing the first metal oxide particles according to the present invention, the pH range of the suspension containing the first metal oxide particles (the titanium oxide particles coated with the silicon-containing hydrated oxide) is 3 to 9 and more preferably 4 to 8. By making the pH of the suspension 9 or less, the change in volume average particle diameter due to alkali dissolution can be suppressed, and the suspension It is because handling property can be improved by making pH of 3 or more.

"First water-soluble polymer"
In the present invention, each high refractive index layer and each low refractive index layer contains a water-soluble polymer (including the photoreactive polymer compound of the present invention) that functions as a binder. The water-soluble polymer contained in each high refractive index layer is referred to as a first water-soluble polymer, and the water-soluble polymer contained in each low refractive index layer is referred to as a second water-soluble polymer. In the present invention, the first water-soluble polymer and the second water-soluble polymer may be the same component or different components, but the first water-soluble polymer and the second water-soluble polymer may be different from each other. More preferably, the constituent components of the two water-soluble polymers are different.

  The first water-soluble polymer according to the present invention or the second water-soluble polymer, which will be described later, is dissolved in water to a concentration of 0.5% by mass at the temperature at which the water-soluble polymer is most dissolved. In this case, the mass of the insoluble matter separated when leaking through the G2 glass filter (maximum pores 40 to 50 μm) is within 50 mass% of the added water-soluble polymer.

  Examples of the first water-soluble polymer according to the present invention include polymers having reactive functional groups, gelatin, thickening polysaccharides, and the like. These first water-soluble polymers may be used alone or in combination of two or more. The first water-soluble polymer may be a synthetic product or a commercially available product. Hereinafter, the first water-soluble polymer according to the present invention will be described in detail. Since the photoreactive polymer compound of the present invention can be contained in the second water-soluble polymer of the low refractive index layer, the details of the low refractive index layer (second water-soluble polymer, etc.) are described. Will be described in detail.

(Polymer having reactive functional group)
Examples of the polymer having a reactive functional group used in the present invention include polyvinyl alcohols, polyvinyl pyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate. -Acrylic resin such as acrylic acid ester copolymer or acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer Styrene-acrylate resins such as styrene-α-methylstyrene-acrylic acid copolymer, or styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-sodium styrenesulfonate copolymer, styrene- 2-hydroxyethyla Chryrate copolymer, styrene-2-hydroxyethyl acrylate-potassium styrene sulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene- Mention may be made of vinyl acetate copolymers such as maleic acid copolymers, vinyl acetate-maleic ester copolymers, vinyl acetate-cuponic acid copolymers, vinyl acetate-acrylic acid copolymers, and salts thereof. . Among these, polyvinyl alcohol is particularly preferably used in the present invention. Below, polyvinyl alcohol is demonstrated.

  The polyvinyl alcohol preferably used in the present invention includes various modified polyvinyl alcohols in addition to normal polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate.

  As the polyvinyl alcohol obtained by hydrolyzing vinyl acetate, those having an average degree of polymerization of 1,000 or more are preferably used. In particular, those having an average degree of polymerization of 1500 to 5,000 are preferably used. The degree of saponification is preferably 70 to 100%, particularly preferably 80 to 99.5%.

  Anion-modified polyvinyl alcohol is described in, for example, 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 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 as described in JP-A-7-9758 is added to a part of vinyl alcohol, and JP-A-8-25795. The block copolymer of the vinyl compound and vinyl alcohol which have the described hydrophobic group is mentioned. Polyvinyl alcohol can be used in combination of two or more, such as the degree of polymerization and the type of modification.

  Examples of the cation-modified polyvinyl alcohol include primary to tertiary amino groups and quaternary ammonium groups, as described in JP-A No. 61-10383, in the main chain or side chain of the polyvinyl alcohol. 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, 1-dimethyl-3-dimethylaminopropyl) acrylamide and the like. The ratio of the cation-modified group-containing monomer of the cation-modified polyvinyl alcohol is 0.1 to 10 mol%, preferably 0.2 to 5 mol%, relative to vinyl acetate.

(gelatin)
As the gelatin applicable to the present invention, various gelatins that have been widely used in the field of silver halide photographic light-sensitive materials can be applied. For example, in addition to acid-processed gelatin and alkali-processed gelatin, production of gelatin is possible. Enzyme-treated gelatin and gelatin derivatives that undergo enzyme treatment in the process, that is, modified with a reagent that has an amino group, imino group, hydroxyl group, carboxyl group as a functional group in the molecule and a group obtained by reaction with it. It may be quality. Well-known methods for producing gelatin are well known. H. James: The Theory of Photographic Process 4th. ed. Reference can be made to descriptions such as 1977 (Macmillan) 55, Science Photo Handbook (above) 72-75 (Maruzen), Fundamentals of Photographic Engineering-Silver Salt Photo Hen 119-124 (Corona). Also, Research Disclosure Magazine Vol. 176, No. And gelatin described in Section IX of 17643 (December, 1978).

(Gelatin hardener)
When gelatin is used, a gelatin hardener can be added as necessary. As the hardener that can be used, known compounds that are used as hardeners for ordinary photographic emulsion layers can be used. For example, vinylsulfone compounds, urea-formalin condensates, melanin-formalin condensates, epoxy compounds And organic hardeners such as aziridine compounds, active olefins and isocyanate compounds, and inorganic polyvalent metal salts such as chromium, aluminum and zirconium.

(Cellulose)
As the celluloses that can be used in the present invention, a water-soluble cellulose derivative can be preferably used. For example, water-soluble cellulose derivatives such as carboxymethyl cellulose (cellulose carboxymethyl ether), methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose. Examples thereof include cellulose derivatives, carboxymethyl cellulose (cellulose carboxymethyl ether) and carboxyethyl cellulose which are carboxylic acid group-containing celluloses. Other examples include cellulose derivatives such as nitrocellulose, cellulose acetate furopionate, cellulose acetate, and cellulose sulfate.

(Thickening polysaccharide)
The thickening polysaccharide that can be used in the present invention is not particularly limited, and examples thereof include generally known natural simple polysaccharides, natural complex polysaccharides, synthetic simple polysaccharides, and synthetic complex polysaccharides. . For details of these polysaccharides, reference can be made to “Biochemical Encyclopedia (2nd edition), Tokyo Chemical Doujinshi”, “Food Industry”, Vol. 31 (1988), p.

  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, and when adding metal oxide fine particles, it causes a viscosity increase that seems to be due to hydrogen bonding with the metal oxide fine particles at a low temperature. When added, the viscosity at 15 ° C. is 1.0 mPa.s. s or higher, preferably 5.0 mPa.s. s or more, and more preferably 10.0 mPa.s. It is a polysaccharide having a viscosity increasing ability of s or more.

  Examples of the thickening polysaccharide applicable to the present invention include 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), arabinogalactoglycan (eg, soybean-derived glycan, microorganism-derived glycan, etc.), Red algae such as glucuronoglycan (eg gellan gum), glycosaminoglycan (eg hyaluronic acid, keratan sulfate etc.), alginic acid and alginates, agar, κ-carrageenan, λ-carrageenan, ι-carrageenan Derived from Such as natural polymer polysaccharides. From the viewpoint of not lowering the dispersion stability of the metal oxide particles coexisting in the coating solution, it is preferable that the structural unit does not have a carboxylic acid group or a sulfonic acid group. Examples of such thickening polysaccharides include 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. It is preferable that it is a polysaccharide which consists only of. Specifically, tamarind seed gum known as xyloglucan whose main chain is glucose and side chain is glucose, guar gum known as galactomannan whose main chain is mannose and side chain is glucose, cationized guar gum, Hydroxypropyl guar gum, locust bean gum, tara gum, and arabinogalactan whose main chain is galactose and whose side chain is arabinose can be preferably used. In the present invention, tamarind, guar gum, cationized guar gum, and hydroxypropyl guar gum are particularly preferable. In the present invention, two or more thickening polysaccharides can be used in combination.

  Among the above, polyvinyl alcohol is preferable as the first water-soluble polymer. When polyvinyl alcohol is used, other water-soluble polymer may be used in combination with polyvinyl alcohol. At this time, the content of the other water-soluble polymer used in combination is 100% by mass of the solid content of the high refractive index layer. On the other hand, it can be used at 0.5 to 10% by mass.

  The weight average molecular weight of the first water-soluble polymer according to the present invention is preferably 1,000 to 200,000, more preferably 3,000 to 40,000. The weight average molecular weight in the present invention can be measured by a known method. For example, it can be measured by a static light scattering method, gel permeation chromatography (GPC), TOFMASS, etc. It is measured by a gel permeation mouth-to-gratula method (GPC method) which is a known method.

  In the present invention, the first water-soluble polymer is preferably contained in the range of 5 to 50% by mass, and preferably contained in the range of 10 to 40% by mass with respect to the total amount of the high refractive index layer. Is more preferable. However, for example, when an emulsion resin is used in combination with the first water-soluble polymer, it may be contained in an amount of 2% by mass or more, preferably 3% by mass or more. If the content of the first water-soluble polymer is 5% by mass or more (2% by mass or more when used in combination with an emulsion resin), the film surface may be disturbed during drying after coating the high refractive index layer. It is excellent in that high transparency can be expressed. On the other hand, if the content of the first water-soluble polymer is 50% by mass or less, high transparency can be expressed, and the relative metal oxide content becomes appropriate, and the high refractive index layer and It becomes easy to increase the refractive index difference of the low refractive index layer.

"Curing agent"
In the present invention, a curing agent can be used to cure the water-soluble polymer as a binder. The curing agent that can be used together with the first water-soluble polymer is not particularly limited as long as it causes a curing reaction with the water-soluble polymer. For example, when polyvinyl alcohol is used as the first water-soluble polymer, boric acid and its salt are preferable as the curing agent. In addition to boric acid and its salts, known ones can be used, and in general, a compound having a group capable of reacting with polyvinyl alcohol or a compound that promotes the reaction between different groups possessed by polyvinyl alcohol. Select and use. Specific examples of the curing agent 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- (3, 5, -S-triazine, etc.), active vinyl compounds (1,3,5-trisacryloyl-hexahydro-s-triazine, bisvinylsulfonylmethyl ether, etc.), aluminum alum, borax and the like.

  Boric acid or a salt thereof refers to an oxygen acid having a central atom as a central atom and a salt thereof, and specifically includes orthoboric acid, diboric acid, metaboric acid, tetraboric acid, pentaboric acid, and octabored acid. Boric acid and their salts.

  Boric acid having a boron atom and a salt thereof as a curing agent may be used alone or in combination of two or more. Particularly preferred is a mixed aqueous solution of boric acid and borax.

  The aqueous solutions of boric acid and borax can be added only in relatively dilute aqueous solutions, respectively, but by mixing them both can be made into a concentrated aqueous solution and the coating solution can be concentrated. Further, there is an advantage that the pH of the aqueous solution to be added can be controlled relatively freely.

  In the present invention, it is preferable to use at least one of boric acid and its salt and borax in order to obtain the effects of the present invention. When at least one of boric acid and its salts and borax is used, metal oxide particles and water-soluble polymer polyvinyl alcohol OH groups and hydrogen bonding networks are more easily formed, resulting in a high refractive index. It is considered that interlayer mixing between the layer and the low refractive index layer is suppressed, and preferable optical reflection characteristics (for example, reflection characteristics for a specific wavelength region, specifically, near-infrared shielding characteristics) are achieved. In particular, a set coating process was used in which a multilayer coating of a high refractive index layer and a low refractive index layer was applied by a coater, the film surface temperature of the coating film was once cooled to about 15 ° C., and then the film surface was dried. In some cases, the effect can be expressed more preferably.

  The content of the curing agent in the high refractive index layer is preferably 1 to 10% by mass and more preferably 2 to 6% by mass with respect to 100% by mass of the solid content of the high refractive index layer.

  In particular, the total amount of the curing agent used when polyvinyl alcohol is used as the first water-soluble polymer is preferably 1 to 600 mg per 1 g of polyvinyl alcohol, and more preferably 100 to 600 mg per 1 g of polyvinyl alcohol.

"Surfactant"
The high refractive index layer according to the present invention and the low refractive index layer described later preferably contain a surfactant from the viewpoint of coatability.

  Anionic surfactants, nonionic surfactants, amphoteric surfactants and the like can be used as the surfactant used for adjusting the surface tension at the time of coating, but anionic surfactants are more preferable. Preferred compounds include those containing a hydrophobic group having 8 to 30 carbon atoms and a sulfonic acid group or a salt thereof in one molecule.

  Anionic surfactants include alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkane or olefin sulfonates, alkyl sulfate esters, polyoxyethylene alkyl or alkyl aryl ether sulfate esters, alkyl phosphates, alkyl diphates. Use surfactants selected from the group consisting of enyl ether disulfonates, ether carboxylates, alkylsulfosuccinic acid ester salts, α-sulfo fatty acid esters and fatty acid salts, condensates of higher fatty acids with amino acids, naphthenates, and the like. be able to. Preferred anionic surfactants are alkylbenzene sulfonates (especially those of linear alkyl), alkanes or olefin sulfonates (especially secondary alkane sulfonates, α-olefin sulfonates), alkyl sulfates Salts, polyoxyethylene alkyl or alkyl aryl ether sulfates (especially polyoxyethylene alkyl ether sulfates), alkyl phosphates (especially monoalkyl type), ether carboxylates, alkyl sulfosuccinates, α-sulfo fatty acid esters and A surfactant selected from the group consisting of fatty acid salts, and alkylsulfosuccinate is particularly preferable.

  The content of the surfactant in the high refractive index layer is preferably 0.001 to 0.03% by mass, with the total mass of the coating liquid of the high refractive index layer being 100% by mass, and preferably 0.005 to 0.03. More preferably, it is 015 mass%.

"Additive"
Various additives can be used in the high refractive index layer according to the present invention and the low refractive index layer described later, if necessary. Moreover, it is preferable that content of the additive in a high refractive index layer is 0-20 mass% with respect to 100 mass% of solid content of a high refractive index layer. Examples of such additives are described below.

(Amino acids with an isoelectric point of 6.5 or less)
The high refractive index layer or the low refractive index layer according to the present invention may contain an amino acid having an isoelectric point of 6.5 or less. By including an amino acid, the dispersibility of the metal oxide particles in the high refractive index layer or the low refractive index layer can be improved.

  The amino acid is a compound having an amino group and a carboxyl group in the same molecule, and may be any type of amino acid such as α-, β-, and γ-. Some amino acids have optical isomers, but in the present invention, there is no difference in effect due to optical isomers, and any isomer can be used alone or in racemic form.

  For a detailed explanation of amino acids, reference can be made to the descriptions on pages 268 to 270 of the Chemical Dictionary 1 Reprint (Kyoritsu Shuppan; issued in 1960).

  Specific examples of preferable amino acids include aspartic acid, glutamic acid, glycine, serine, and the like, and glycine and serine are particularly preferable.

  The isoelectric point of an amino acid means this pH value because an amino acid balances positive and negative charges in a molecule at a specific pH, and the overall charge becomes zero. The isoelectric point of each amino acid can be determined by isoelectric focusing at a low ionic strength.

(Emulsion resin)
The high refractive index layer or the low refractive index layer according to the present invention may further contain an emulsion resin. By including the emulsion resin, the flexibility of the film is increased and the workability such as sticking to glass is improved.

  The emulsion resin is a resin in which fine resin particles having an average particle diameter of about 0.01 to 2.0 μm, for example, are dispersed in an emulsion state in an aqueous medium, and an oil-soluble monomer having a high hydroxyl group. Obtained by emulsion polymerization using a molecular dispersant. There is no fundamental difference in the polymer component of the resulting emulsion resin depending on the type of dispersant used. Examples of the dispersant used in the polymerization of the emulsion include polyoxyethylene nonylphenyl ether in addition to low molecular weight dispersants such as alkylsulfonate, alkylbenzenesulfonate, diethylamine, ethylenediamine, and quaternary ammonium salt. , Polymer dispersing agents such as polyoxyethylene lauryl ether, hydroxyethyl cellulose, and polyvinylpyrrolidone. When emulsion polymerization is performed using a polymer dispersant having a hydroxyl group, the presence of hydroxyl groups is estimated on at least the surface of fine particles, and the emulsion resin polymerized using other dispersants has chemical and physical properties of the emulsion. Different.

  The polymer dispersant containing a hydroxyl group is a polymer dispersant having a weight average molecular weight of 10,000 or more, and has a hydroxyl group substituted at the side chain or terminal. For example, an acrylic polymer such as sodium polyacrylate or polyacrylamide is used. Examples of such a polymer include those obtained by copolymerization of 2-ethylhexyl acrylate, polyethers such as polyethylene glycol and polypropylene glycol, and polyvinyl alcohol. Polyvinyl alcohol is particularly preferable.

  Polyvinyl alcohol used as a polymer dispersant is an anion-modified polyvinyl alcohol having an anionic group such as a cation-modified polyvinyl alcohol or a carboxyl group in addition to ordinary polyvinyl alcohol obtained by hydrolysis of polyvinyl acetate. Further, modified polyvinyl alcohol such as silyl-modified polyvinyl alcohol having a silyl group is also included. Polyvinyl alcohol has a higher effect of suppressing the occurrence of cracks when forming a high refractive index layer or a low refractive index layer when the average degree of polymerization is high, but when the average degree of polymerization is within 5000, the viscosity of the emulsion resin Is not expensive and easy to handle during manufacture. Accordingly, the average degree of polymerization is preferably 300 to 5000, more preferably 1500 to 5000, and particularly preferably 3000 to 4500. The saponification degree of polyvinyl alcohol is preferably 70 to 100 mol%, more preferably 80 to 99.5 mol%.

  Examples of the resin that is emulsion-polymerized with the above polymer dispersant include homopolymers or copolymers of ethylene monomers such as acrylic acid esters, methacrylic acid esters, vinyl compounds, and styrene compounds, and diene compounds such as butadiene and isofrene. Examples of the polymer include acrylic resins, styrene-butadiene resins, and ethylene-vinyl acetate resins.

  In addition, the high refractive index layer according to the present invention or the low refractive index layer described later includes, for example, an ultraviolet ray described in JP-A-57-74193, 57-87988 and 62-261476. Absorbents, described in JP-A-57-74192, JP-A-57-87989, JP-A-60-72785, JP-A-61-146591, JP-A-1-95091 and JP-A-3-13376 Anti-fading agents, various anionic, cationic or nonionic surfactants, JP-A-59-42993, JP-A-59-52689, JP-A-62-280069, JP-A-61-242871, and JP-A Fluorescent whitening agent, sulfuric acid, phosphoric acid, acetic acid, citric acid, sodium hydroxide, potassium hydroxide, carbonate pH adjusting agents such as um, antifoaming agents, lubricants such as diethylene glycol, preservatives, antistatic agents, may contain various known additives such as a matting agent.

  As described above, the present invention includes the first metal oxide particles and the first water-soluble polymer by including the first water-soluble polymer and the first metal oxide particles in the high refractive index layer. And the intermixing of the high refractive index layer and the low refractive index layer is suppressed, and problems such as binder deterioration and choking due to the photocatalytic activity of the titanium oxide particles can be prevented. Therefore, the optical reflective film of the present invention has excellent durability and film flexibility, high visible light transmittance, and excellent reflection characteristics (for example, near-infrared shielding) for a specific wavelength region.

<Low refractive index layer>
The low refractive index layer according to the present invention includes the second water-soluble polymer and the second metal oxide particles as essential components, and is selected from the group consisting of a curing agent, a surfactant, and various additives as necessary. It may contain at least one kind.

  The refractive index of the low refractive index layer according to the present invention is preferably 1.10 to 1.60, more preferably 1.30 to 1.50.

  The thickness per layer of the low refractive index layer according to the present invention is preferably 20 to 800 nm, and more preferably 50 to 350 nm.

"Second metal oxide particles"
As the second metal oxide particles according to the present invention, silica (silicon dioxide) is preferably used, and specific examples thereof include synthetic amorphous silica and colloidal silica. Of these, acidic colloidal silica sol is more preferably used, and colloidal silica sol dispersed in an organic solvent is more preferably used. In order to further reduce the refractive index, hollow fine particles having pores inside the particles can be used as the second metal oxide particles, and hollow fine particles of silica (silicon dioxide) are particularly preferable. Moreover, well-known metal oxide particles other than a silica can also be used.

  In the present invention, the second metal oxide particles (preferably silicon dioxide) preferably have a primary average particle size of 3 to 100 nm. The average particle size of primary particles of silicon dioxide dispersed in a primary particle state (primary average particle size in a dispersion state before coating) is more preferably 3 to 50 nm, and more preferably 3 to 40 nm. More preferably, 3 to 20 nm is particularly preferable, and 4 to 10 nm is most preferable. Moreover, as an average particle diameter of secondary particle | grains, it is preferable from a viewpoint with few hazes and excellent visible light transmittance | permeability that it is 30 nm or less.

  In the present invention, the primary average particle size of the second metal oxide particles is determined by observing the particles themselves or the particles appearing on the cross section or surface of the refractive index layer with an electron microscope, and the particle size of 1,000 arbitrary particles. Is obtained as a simple average value (number average). Here, the particle diameter of each particle is represented by a diameter assuming a circle equal to the projected area.

  In the present invention, the particle diameter of the second metal oxide particles can be determined by a volume average particle diameter in addition to the primary average particle diameter. In addition, the measuring method of a volume average particle diameter is the same as that of the case of the above-mentioned 1st metal oxide particle.

  The colloidal silica 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. For example, JP-A-57-14091, JP-A-60-219083, JP-A-60-219084, JP-A-61-20792, JP-A-61-188183, JP-A-63-17807, JP-A-4-93284 No. 5, JP-A-5-278324, JP-A-6-92011, JP-A-6-183134, JP-A-6-297830, JP-A-7-81214, JP-A-7-101142. JP-A-7-179029, JP-A-7-137431, and International Publication No. 94/26530. Than is.

  Such colloidal silica may be a synthetic product or a commercially available product. The surface of the colloidal silica may be cation-modified, or may be treated with Al, Ca, Mg, Ba or the like.

  In the present invention, hollow fine particles can also be used as the second metal oxide particles. When hollow fine particles are used, the average particle pore size is preferably 3 to 70 nm, more preferably 5 to 50 nm, and even more preferably 5 to 45 nm. The average particle pore size of the hollow fine particles is an average value of the inner diameters of the hollow fine particles. In the present invention, when the average particle pore diameter of the hollow fine particles is within the above range, the refractive index of the low refractive index layer is sufficiently lowered. The average particle diameter is 50 or more at random, which can be observed as an ellipse in a circular, elliptical or substantially circular shape by electron microscope observation, and obtains the pore diameter of each particle. Is obtained. In the present specification, as the average particle pore diameter, the minimum distance among the distances between the outer edges of the pore diameter that can be observed as a circle, an ellipse, a substantially circle or an ellipse, between two parallel lines Means.

  The content of the second metal oxide particles in the low refractive index layer is preferably 0.1 to 70% by mass, and 30 to 70% by mass with respect to 100% by mass of the solid content of the low refractive index layer. More preferably, it is more preferably 45 to 65% by mass.

"Second water-soluble polymer"
Specific examples, preferred weight average molecular weights, and the like of the second water-soluble polymer according to the present invention are the same as those described in the column of the first water-soluble polymer, and thus the description thereof is omitted here. . As the second water-soluble polymer according to the present invention, polyvinyl alcohol is preferably used, and a polyvinyl alcohol of a type different from the polyvinyl alcohol preferably used as the first water-soluble polymer is more preferably used. Here, the type of polyvinyl alcohol different from the first water-soluble polymer means that at least one selected from the group consisting of the type of modification, the degree of saponification, the degree of polymerization, and the weight average molecular weight is the first water-soluble polymer. It is different from polyvinyl alcohol used as a conductive polymer.

  In the low refractive index layer according to the present invention, together with polyvinyl alcohol preferably used as the second water-soluble polymer, another water-soluble polymer may be used in combination, and in this case, the content of the other polymer to be used together Can be used at 0.5 to 10% by mass with respect to 100% by mass of the solid content of the low refractive index layer.

  The content of the second water-soluble polymer in the low refractive index layer according to the present invention is preferably 10 to 99.9% by mass with respect to the total amount of the low refractive index layer, and is 20 to 70% by mass. It is more preferable. If the content of the second water-soluble polymer is 10% by mass or more, it is possible to express high transparency without disturbing the film surface during drying after coating the low refractive index layer. Are better. On the other hand, if the content of the second water-soluble polymer is 99.9% by mass or less, not only high transparency can be expressed, but the relative content of metal oxide becomes appropriate, and the low refractive index layer and the low refractive index layer are low. It becomes easy to increase the refractive index difference of the refractive index layer.

  In the low refractive index layer, the content of the other water soluble polymer used in combination with polyvinyl alcohol preferably used as the second water soluble polymer is 0.000% with respect to 100% by mass of the solid content of the low refractive index layer. It can be used at 5 to 10% by mass.

"Curing agent"
Similarly to the high refractive index layer, the low refractive index layer according to the present invention may further include a curing agent. There is no particular limitation as long as it causes a curing reaction with the second water-soluble polymer related to the low refractive index layer. In particular, as a curing agent when polyvinyl alcohol is used as the second water-soluble polymer, at least one of boric acid, a salt thereof, and borax is preferable. Besides these, known ones can be used.

  The content of the curing agent in the low refractive index layer is preferably 1 to 10% by mass and more preferably 2 to 6% by mass with respect to 100% by mass of the solid content of the low refractive index layer.

  In particular, when polyvinyl alcohol is used as the second water-soluble polymer, the total amount of the curing agent used is preferably 1 to 600 mg per 1 g of polyvinyl alcohol, and more preferably 100 to 600 mg per 1 g of polyvinyl alcohol.

  Specific examples of the curing agent and the like are the same as those of the above-described high refractive index layer, and thus description thereof is omitted here.

"Surfactant"
The low refractive index layer according to the present invention also preferably contains a surfactant from the viewpoint of coatability. In particular, it is preferable to contain an anionic surfactant. As the surfactant according to the present invention, the same surfactants as those contained in the high refractive index layer can be used, and the description thereof is omitted here.

  The content of the surfactant in the low refractive index layer is preferably 0.001 to 0.03 mass%, with the total amount of the coating liquid of the low refractive index layer being 100 mass%, and preferably 0.005 to 0.02. More preferably, it is mass%.

"Additive"
Various additives can be used in the low refractive index layer according to the present invention as needed, and the various additives in the low refractive index layer are the same as the additives used in the high refractive index layer. The description thereof is omitted here.

  As described above, in the optical reflective film of the present invention, the high refractive index layer containing the first water-soluble polymer and the first metal oxide particles, the second water-soluble polymer, and the second on the substrate. And an optical interference film formed by alternately laminating low refractive index layers containing metal oxide particles. Furthermore, in the optical reflective film of the present invention, a polymer compound (also referred to as a photoreactive polymer compound) in which at least one of the high refractive index layer and the low refractive index layer constituting the optical interference film is crosslinked by active energy rays. A photocrosslinkable polymer compound that is obtained by irradiating active energy rays to the photoreactive polymer compound having a plurality of side chains in the hydrophilic main chain and that is cross-linked between the side chains. It is characterized by containing as.

<Photoreactive polymer compound>
A polymer compound (photoreactive polymer compound) having a plurality of side chains in a hydrophilic main chain and capable of being cross-linked between side chains by irradiating active energy rays, according to the present invention, Saponified vinyl acetate (polyvinyl alcohol), polyvinyl acetal, polyethylene oxide, polyalkylene oxide, polyvinyl pyrrolidone, polyacrylamide, polyacrylic acid, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, or derivatives of these hydrophilic resins, and these Introducing a modifying group such as a photodimerization type, a photodecomposition type, a photopolymerization type, a photo-denaturation type, or a photo-depolymerization type to the side chain with respect to at least one hydrophilic resin selected from the group consisting of copolymers It is. Photopolymerizable crosslinking groups are desirable from the viewpoints of weather resistance and water resistance.

  There is a preferred combination between the ionicity of the first or second metal oxide particles and the ionicity of the side chain of the photoreactive polymer compound. By selecting anionicity for the first or second metal oxide particles and combining nonionicity or anionicity in the side chain, aggregation is prevented and weather resistance, water resistance, haze, scratch resistance, adhesion It turned out to be excellent from a viewpoint. The side chain is most preferably nonionic. The reason is not clear, but in the case of a combination of the above ions, the aggregation with the first and second metal oxide particles in the coating solution at the time of production is reduced, which affects the above effect. There is a possibility.

  It is preferable that the partial structure of the hydrophilic main chain and side chain of the photoreactive polymer compound of the present invention is represented by the following general formula (A).

  In the above formula, Poly represents a hydrophilic main chain. Saponified polyvinyl acetate (polyvinyl alcohol), polyvinyl acetal, polyethylene oxide, polyalkylene oxide, polyvinyl pyrrolidone, polyacrylamide, polyacrylic acid, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, or derivatives of these hydrophilic resins, and These copolymers are preferred.

The inside of {} represents a side chain. In the side chain, X ₁ represents a (p + 1) -valent linking group. p represents a positive integer, preferably an integer of 1 to 5. Specifically, when p = 1, X ₁ represents a divalent linking group, for example, an alkylene group, an arylene group, a heteroarylene group, an ether group, a thioether group, an imino group, an ester group, an amide group, a sulfonyl group Groups may be mentioned, and these may be combined to form one divalent or higher group. In addition, when p = 2 or more, a plurality of B and Y _l described later may be the same or different.

X _l is preferably an alkylene oxide or a divalent or higher linking group in which an aromatic group is combined at least.

  B represents a crosslinking group. Specifically, it is a group containing a double bond or a triple bond, and represents, for example, an acryl group, a methacryl group, a pinyl group, an allyl group, a diazo group, or an azide group. An acrylic group and a methacryl group are preferable.

Y _l represents a hydrogen atom or a substituent. Specifically, the substituent is a halogen atom (for example, fluorine atom, chlorine atom, etc.), an alkyl group (for example, methyl, ethyl, butyl, ventil, 2-methoxyethyl, trifluoromethyl, 2-ethylhexyl, cyclohexyl, etc.) , Aryl groups (eg, phenyl, p-tolyl, naphthyl, etc.), acyl groups (eg, acetyl, propionyl, benzoyl, etc.), alkoxy groups (eg, methoxy, ethoxy, butoxy, etc.), alkoxycarbonyl groups (eg, methoxycarbonyl) I-propoxycarbonyl etc.), acyloxy group (eg acetyloxy, ethylcarbonyloxy etc.), carbamoyl group (eg methylcarbamoyl, ethylcarbamoyl, butylcarbamoyl, phenylcarbamoyl etc.), sulfamoyl group (eg sulfayl) Yl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl, etc.), alkylthio groups (eg, methylthio, ethylthio, octylthio, etc.), arylthio groups (eg, phenylthio, p-tolylthio, etc.), alkylureido groups (eg, , Methylureido, ethylureido, methoxyethylureido, dimethylureido, etc.), arylureido groups (eg, phenylureido etc.), alkylsulfonamide groups (eg, methanesulfonamide, ethanesulfonamide, butanesulfonamide, trifluoromethylsulfone) Amide, 2,2,2-trifluoroethylsulfonamide, etc.), arylsulfonamide groups (eg, phenylsulfonamide, tolylsulfonamide, etc.), alkylaminosulfonylamino groups (eg, Methylaminosulfonylamino, ethylaminosulfonylamino, etc.), arylaminosulfonylamino groups (eg, phenylaminosulfonylamino, etc.), hydroxy groups, heterocyclic groups (eg, pyridyl, pyrazolyl, imidazolyl, furyl, thienyl, etc.), etc. In addition, these may have a substituent.

  m represents 0 or 1.

  n represents 0 or 1.

(Hydrophilic main chain; main chain polyvinyl alcohol)
In the photoreactive polymer compound of the present invention, in the hydrophilic main chain, polyvinyl alcohol, which is a saponified product of polyvinyl acetate, is preferable from the viewpoint of simplicity of side chain introduction and weather resistance of the resulting optical reflection film. The saponification degree is preferably 77% or more and 99% or less. The degree of polymerization is preferably 200 or more and 5000 or less, more preferably 500 or more and 4500 or less, and further preferably 1000 or more and 4500 or less. If the degree of saponification and the degree of polymerization of the saponified polyvinyl acetate (polyvinyl alcohol) are both within the above ranges, the visible light transmittance and the near infrared reflectance after the weather resistance test are excellent, and the appearance, particularly cracks; Excellent in that there are no cracks, low haze (water haze) after water resistance test, excellent transparency, no film peeling, and good film properties (especially excellent weather resistance and water resistance). Yes. In particular, if the degree of polymerization is within the above range, the weather resistance tends to be better as it becomes larger.

(Modification rate of side chain)
In the photoreactive polymer compound of the present invention, the modification rate of the side chain with respect to the hydrophilic main chain is preferably in the range of 0.3 to 4.5 mol%, more preferably in the range of 0.7 to 4.5 mol%. The range of 1.0 to 4.5 mol% is more preferable. If the modification rate of the side chain with respect to the hydrophilic main chain is within the above range, the visible light transmittance and the near infrared reflectance after the weather resistance test are excellent, and there is no appearance, particularly cracks; cracks, after the water resistance test. It is excellent in that the haze (cloudiness value) is low, the transparency is excellent, the film is not peeled off, and good film properties (particularly excellent weather resistance and water resistance) can be expressed. If the modification rate of the side chain with respect to the hydrophilic main chain is 0.3 mol% or more, preferably 0.7 mol or more, more preferably 1 mol% or more, in addition to the above film properties, the crosslinkability is not insufficient. This is excellent in that the effect of the present invention can be sufficiently exhibited. If the modification rate of the side chain with respect to the main chain is 4.5 mol% or less, in addition to the above film properties, the crosslinking density will not be too high, so that the film will not be hard and brittle, and the flexibility (flexibility) ), And is strong and strong (hard to crack and difficult to peel off), and is excellent in that high film strength can be expressed.

  In the photoreactive polymer compound of the present invention, a more preferable structure is a photosensitive resin described in JP-A-56-67309. This photosensitive resin contains a side chain of a 2-azido-5-nitrophenylcarbonyloxyethylene structure (nonionic) represented by the following general formula (1) in the polyvinyl alcohol structure, or the following general formula (2 And a side chain of a 4-azido-3-nitrophenylcarbonyloxyethylene structure (nonionic) represented by formula (1).

  A side chain of a modifying group (anionic) represented by the following general formula (3) is also preferably used.

  In the formula, R represents an alkylene group or an aromatic ring. A benzene ring is preferred.

  As the photopolymerization type modifying group, for example, a resin (nonionic) represented by the following general formula (4) disclosed in JP-A Nos. 2000-181062 and 2004-189841 is preferable from the viewpoint of reactivity.

In the formula, R ₂ represents methyl (abbreviated as Me) or a hydrogen atom (abbreviated as H), n represents 1 or 2, X represents (CH ₂ ) _m —COO— or —O—, Y represents an aromatic ring or a single bond, and m represents an integer of 0 to 6.

  Moreover, it is also preferable to use the photopolymerization type | mold modified group (nonionic property) represented by following General formula (5) described in Unexamined-Japanese-Patent No. 2004-161942 for a conventionally well-known water-soluble resin.

In the formula, R ₃ represents Me or H, and R ₄ represents a linear or branched alkylene group having 2 to 10 carbon atoms.

  Furthermore, modified groups (nonionic) represented by the following general formulas (6) to (8) are also preferably used.

  The photoreactive polymer compound which is such an active energy ray-crosslinking resin is based on the total mass of the coating solution for the low refractive index layer or the coating solution for the high refractive index layer (hereinafter also referred to simply as coating solution). It is preferable to contain 0.8-5.0 mass%. The presence of 0.8% by mass or more improves the crosslinking efficiency, and the viscosity of the coating layer (low refractive index layer or high refractive index layer) after coating, drying, and crosslinking (curing) suddenly increases (film strength) In particular, the weather resistance, water resistance, haze, and scratch resistance are more preferable when a multilayer coating of a high refractive index layer and a low refractive index layer is applied simultaneously. In the case of 5.0 mass% or less, it is preferable at the point which the pot life etc. of a coating liquid are maintained and a coating failure does not generate | occur | produce easily.

(Mixing ratio between photoreactive polymer compound and first or second water-soluble polymer)
In the present invention, the first or second water-soluble polymer (the coating solution for the low refractive index layer or the coating solution for the high refractive index layer (coating solution) used for forming the low refractive index layer or the high refractive index layer (the second water soluble polymer). A photoreactive polymer compound is used instead of at least a part of the water-soluble polymer. Specifically, the content of the photoreactive polymer compound in the coating solution is 5 to 80% by mass, preferably 10 to 80% by mass, based on the total amount of the photoreactive polymer compound and the water-soluble polymer. More preferably, it is 20-70 mass%, More preferably, it is the range of 30-60 mass%. If the content of the photoreactive polymer compound is 5% by mass or more, crosslinking between the side chains is sufficiently achieved by irradiation with active energy rays, and the weather resistance and water resistance of the resulting optical interference film are improved. It is excellent in that it can. If the content of the photoreactive polymer compound is 80% by mass or less, the crosslinking is not excessively strong, and the resulting high refractive index layer and low refractive index layer are not too hard and brittle. Since it has strength, it is excellent in that it can prevent film cracking from the production stage to the product stage (practical stage) and can improve the weather resistance of the resulting optical interference film. In the case of only the photoreactive polymer compound (100% by mass), the film becomes too hard due to crosslinking and becomes brittle and causes film cracking. Further, in the case of only the photoreactive polymer compound, since the degree of polymerization is high and the viscosity is high, it is difficult to apply, the surface of the application layer becomes uneven, and light is scattered (reflectance decreases). From such a viewpoint, as described above, the first or second water-soluble polymer functioning as a binder is used as an essential component (preferably at the above-mentioned content) to maintain excellent optical reflection characteristics. Thus, an optical reflection film having improved weather resistance and water resistance of the optical interference film can be provided.

  In the photoreactive polymer compound that is an active energy ray cross-linking resin of the present invention, the main chain having a certain degree of polymerization is cross-linked through a cross-linking bond between side chains. The effect of increasing the molecular weight per photon is remarkably large with respect to the active energy ray-crosslinked resin that polymerizes through a simple chain reaction. On the other hand, in the conventionally known active energy ray curable resins, the number of crosslinking points is not controllable, so the physical properties of the cured film cannot be controlled, and it tends to be a hard and brittle optical interference film.

  In the photoreactive polymer compound, which is an active energy ray cross-linking resin used in the present invention, the number of cross-linking points can be completely controlled by the length of the hydrophilic main chain and the amount of side chains introduced, depending on the purpose. The physical properties of the optical interference film can be controlled.

  Furthermore, the coating liquid containing the conventionally known active energy ray-curable resin is almost entirely curable components other than the first and second metal oxide particles, and therefore the layer after curing becomes too hard. The photoreactive polymer compound, which is an active energy ray cross-linking resin used in the present invention, is required in a small amount, whereas it becomes brittle and it is difficult to obtain an optical reflecting film having sufficient film strength. Since there are many dry components, the film strength after drying and crosslinking can be improved, and the adhesion is good.

(Photopolymerization initiator, sensitizer)
In the present invention, it is also preferable to add a photopolymerization initiator or a sensitizer to the coating liquid (refractive index layer) to which the photoreactive polymer compound is added. These compounds may be dissolved or dispersed in a solvent, or may be chemically bonded to the photosensitive resin.

  There is no restriction | limiting in particular about the photoinitiator and photosensitizer which are applied, A conventionally well-known thing can be used.

  Although there is no restriction | limiting in particular about the photoinitiator and photosensitizer which are applied, A water-soluble thing is preferable from a viewpoint of mixing property and reaction efficiency. In particular, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone (HMPK), thioxanthone ammonium salt (QTX), and benzophenone ammonium salt (ABQ) are preferable from the viewpoint of miscibility with an aqueous solvent.

  Furthermore, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2) represented by the following general formula (9) from the viewpoint of compatibility with the photoreactive polymer compound which is an active energy ray cross-linking resin. -Propyl) ketone (n = 1, HMPK) and its ethylene oxide adduct (n = 2 to 5) are more preferable.

  In the formula, n represents an integer of 1 to 5.

  Other examples include benzophenones such as benzophenone, hydroxybenzophenone, bis-N, N-dimethylaminobenzophenone, bis-N, N-diethylaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone. Thioxanthones such as thioxatone, 2,4-diethylthioxanthone, isopropylthioxanthone, chlorothioxanthone, and isopropoxychlorothioxanthone. Anthraquinones such as ethyl anthraquinone, benzanthraquinone, aminoanthraquinone and chloroanthraquinone. Acetophenones. Benzoin ethers such as benzoin methyl ether. 2,4,6-trihalomethyltriazines, 1-hydroxycyclohexyl phenyl ketone, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di ( m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-phenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-phenylimidazole dimer, 2- (P-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer, 2- (2,4-dimethoxyphenyl) -4, 2,4,5-triarylimidazole dimer such as 5-diphenylimidazole dimer, benzyldimethyl ketal, 2-benzyl-2-di Tylamino-1- (4-morpholinophenyl) butan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-hydroxy-2-methyl-1-phenyl -Propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, phenanthrenequinone, 9,10-phenanthrenequinone, Benzoins such as methylbenzoin and ethylbenzoin, 9-phenylacridine, acridine derivatives such as 1,7-bis (9,9′-acridinyl) heptane, bisacylphosphine oxide, and mixtures thereof are preferably used. The above may be used alone or in combination.

  In addition to these photopolymerization initiators, accelerators and the like can also be added. Examples of these include ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, ethanolamine, diethanolamine, triethanolamine and the like.

  Even if these photoinitiators are grafted to the side chain with respect to the hydrophilic main chain.

(Active energy rays, irradiation method)
Examples of the active energy ray in the present invention include electron beam, ultraviolet ray, α ray, β ray, γ ray, X ray, etc., but it is dangerous to human body, easy to handle, and industrially uses it. Electron beams and ultraviolet rays are widely used.

  When using an electron beam, the amount of the electron beam to be irradiated is preferably in the range of 0.1 to 30 Mrad. If it is 0.1 Mrad or more, it is excellent at the point from which sufficient irradiation effect is acquired. If it is 30 Mrad or less, it is excellent in that sufficient cross-linking can be performed between the side chains of the active energy ray-crosslinkable polymer compound without deteriorating the constituent materials of the optical reflection film such as the base material.

  When ultraviolet rays are used, the light source is, for example, a low pressure, medium pressure, high pressure mercury lamp, metal halide lamp, xenon lamp having a light emission wavelength in the ultraviolet region, cold cathode tube, hot cathode having an operating pressure of 0.1 kPa to 1 MPa. A conventionally well-known thing, such as a pipe | tube and LED, is used.

(Light irradiation conditions for coating layer (refractive index layer) containing photoreactive polymer compound)
As an irradiation condition of actinic rays (active energy rays), a coating layer containing a photoreactive polymer compound is applied (dried) after coating (and further on the coating layer, further crosslinked with other active energy rays, The layer to be cured, for example, the entire coating layer after applying (drying) the coating solution of the infrared absorbing nanoparticle layer, or the coating solution of the infrared absorbing nanoparticle layer on the opposite side across the coating layer and the substrate After application, the active light is preferably irradiated for 0.001 to 1.0 seconds, more preferably 0.001 to 0.5 seconds. In order to form an optical reflective film excellent in weather resistance, water resistance, haze, scratch resistance, and adhesion, it is particularly important that the irradiation timing is as early as possible.

(Installation of lamp)
As a method for irradiating actinic rays (active energy rays), a basic method is disclosed in JP-A-60-132767. According to this, the light source is provided on both sides of the head unit, and the head and the light source are scanned by the shuttle method. Irradiation is a coating layer after coating (drying) a coating solution containing a photoreactive polymer compound (further, a layer that is further crosslinked and cured with actinic rays on the coating layer, for example, infrared absorption. After applying (drying) the coating solution for the nanoparticle layer, or after applying the infrared absorbing nanoparticle layer coating solution on the opposite side across the coating layer and the substrate, leave a certain amount of time. Will be done. Further, the cross-linking (curing) is completed by another light source that is not driven. In US Pat. No. 6,145,979, as an irradiation method, a method using an optical fiber or a collimated light source is applied to a mirror surface provided on the side of the head unit, and UV (ultraviolet) light is applied to the coating layer. A method of irradiating is disclosed. Any of these irradiation methods can be used in the coating layer (formation of the refractive index layer) of the optical reflective film of the present invention.

  In addition, irradiation with actinic rays (active energy rays) is divided into two stages, and a coating solution containing a photoreactive polymer compound is applied (dried) after coating (and further on the coating layer) A layer that is crosslinked and cured by light, for example, an infrared absorbing nanoparticle layer on the opposite side of the entire coating layer after application (drying) of the infrared absorbing nanoparticle layer or between the coating layer and the substrate A method of irradiating actinic rays with the above-mentioned method for 0.001 to 2.0 seconds and then irradiating actinic rays is also a preferred embodiment. By dividing the irradiation of actinic rays into two stages, it is possible to further suppress the shrinkage of the constituent materials (base materials, etc.) of the optical reflection film that occurs when the photoreactive polymer compound is cross-linked between the side chains. It becomes.

<Photo-crosslinking polymer compound>
In the present invention, at least one layer (preferably all layers) of a high refractive index layer or a low refractive index layer is obtained by irradiating the photoreactive polymer compound with active energy rays according to the above irradiation conditions or the like. It contains a photocrosslinking polymer compound crosslinked between them as a binder. That is, together with the first and second water-soluble polymers that function as a binder, a photocrosslinking polymer compound is used in combination as a binder. Here, the layer containing the photocrosslinkable polymer compound as a binder may be at least one layer of a refractive index layer (a high refractive index layer or a low refractive index layer), preferably a half or more layers, more preferably Is all layers. By making the layer containing the photocrosslinkable polymer compound as a binder more than half of the refractive index layer, more preferably all layers, the optical reflection characteristics and the weather resistance of the optical interference film are the effects of the present invention. The water resistance improvement effect is superior in that it is greater. Further, when a layer containing a photocrosslinkable polymer compound as a binder is used in an adjacent layer, it is excellent in that adhesion is improved even between adjacent layers. In addition, in the case where a layer containing a photocrosslinkable polymer compound as a binder is used for all or intermediate layers of the refractive index layer, in addition to the above effects, the weather resistance and water resistance of the refractive index layer (optical interference film) In addition, the haze (transparency) is improved (improved). When a layer containing a photocrosslinking polymer compound as a binder is used as the uppermost layer (outermost layer) of the refractive index layer, in addition to the effects described above, the film strength on the surface of the optical interference film is improved, thereby improving the scratch resistance. Excellent improvement (improvement) effect. In addition, when using a layer containing a photocrosslinkable polymer compound as a binder for the lowermost layer (base material side) of the refractive index layer, in addition to the above effects, adhesion to the base material and undercoat layer, water resistance Excellent improvement (improvement) effect. In addition, when the layer containing the photocrosslinking polymer compound as the binder is the top layer and combined with the hard coat (HC) layer, the adhesion between the top layer and the HC layer and the film strength are improved. Is excellent in terms of

  The content of the photocrosslinkable polymer compound is preferably in the range of 0.25 to 40% by mass, and preferably 0.5 to 32% by mass with respect to the total amount of the refractive index layer (high refractive index layer or low refractive index layer). A range is more preferred. If the content of the photocrosslinkable polymer compound is 0.25% by mass or more, it is possible to form a photocrosslinkable polymer compound in which the crosslinks are sufficiently formed between the side chains. And water resistance can be improved. Furthermore, using the photocrosslinking of the hard coat (HC) layer, the photoreactive polymer compound of the refractive index layer can be simultaneously crosslinked to form a photocrosslinkable polymer compound. It is excellent in that the adhesion with the pulling layer can be improved. On the other hand, if the content of the photocrosslinkable polymer compound is 40% by mass or less, the relative metal oxide content becomes appropriate, and the refractive index difference between the high refractive index layer and the low refractive index layer is increased. Becomes easier.

(Mixing ratio between photocrosslinkable polymer compound and first or second water-soluble polymer)
In the present invention, the first and second water-soluble polymers (water-soluble polymers) functioning as a binder, which are constituent materials of the low refractive index layer or the high refractive index layer, are used as a binder. It is used together. Specifically, the content of the photocrosslinkable polymer compound is 5 to 80% by mass, preferably 10 to 80%, based on the total amount of the binder (the photocrosslinkable polymer compound and the first or second water-soluble polymer). It is in the range of mass%, more preferably 20 to 70 mass%, and still more preferably 30 to 60 mass%. If the content of the photocrosslinkable polymer compound is 5% by mass or more, it is possible to form a photocrosslinkable polymer compound in which the crosslinks are sufficiently formed between the side chains. It is excellent in that the water resistance can be improved. If the content of the photoreactive polymer compound is 80% by mass or less, the crosslinking does not become too strong, and the obtained refractive index layer has sufficient film strength without becoming too hard and brittle. It is excellent in that the film cracking from the production stage to the product stage (practical stage) can be prevented, and the weather resistance of the obtained optical interference film can be improved.

<Base material>
The thickness of the substrate that is the support of the optical reflection film according to the present invention is preferably 5 to 200 μm, more preferably 15 to 150 μm. Moreover, the base material which concerns on this invention may be what piled up two sheets, and the kind may be the same or different in this case.

  The substrate applied to the optical reflective film of the present invention is not particularly limited as long as it is transparent, and various resin films can be used. Polyolefin films (polyethylene, polypropylene, etc.), polyester films (polyethylene terephthalate) , Polyethylene naphthalate, etc.), polyvinyl chloride, cellulose acetate, and the like, and a polyester film is preferable. Although it does not specifically limit as a polyester film (henceforth polyester), It is preferable that it is polyester which has the film formation property which has a dicarboxylic acid component and a diol component as main structural components. The main constituent dicarboxylic acid components include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylethanedicarboxylic acid, Examples thereof include cyclohexane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl thioether dicarboxylic acid, diphenyl ketone dicarboxylic acid, and phenylindane dicarboxylic acid. Examples of the diol component include ethylene glycol, propylene glycol, tetramethylene glycol, cyclohexanedimethanol, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyethoxyphenyl) propane, bis ( 4-Hydroxyphenyl) sulfone, bisphenol fluorene hydroxyethyl ether, diethylene glycol, neopentyl glycol, hydroquinone, cyclohexanediol and the like. Among the polyesters having these as main constituent components, from the viewpoint of transparency, mechanical strength, dimensional stability, etc., dicarboxylic acid components such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, diol components such as ethylene glycol and 1 Polyester having 1,4-cyclohexanedimethanol as the main constituent is preferred. Among these, polyesters mainly composed of polyethylene terephthalate and polyethylene naphthalate, copolymerized polyesters composed of terephthalic acid, 2,6-naphthalenedicarboxylic acid and ethylene glycol, and mixtures of two or more of these polyesters are mainly used. Polyester as a constituent component is preferable.

  The substrate preferably has a visible light transmittance of 85% or more as shown in JIS R3106-1998, particularly preferably 90% or more. It is advantageous in that the transmittance of the visible light region shown in JIS R3106-1998 is 50% or more when an optical reflection film (particularly a near-infrared shielding film) is used because the base material has the above transmittance or more. It is preferable.

  In addition, the base material using the resin or the like may be an unstretched film or a stretched film. A stretched film is preferable from the viewpoint of strength improvement and thermal expansion suppression.

  The substrate 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 substrate 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.

  In addition, the base material may be subjected to relaxation treatment or off-line 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 a treatment temperature of 100 to 180 ° C. Moreover, it is preferable that the relaxation rate is 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 base material is subjected to the following off-line heat treatment to improve heat resistance and to improve dimensional stability.

(Undercoat layer)
It is preferable that the substrate is coated with the undercoat layer coating solution inline on one side or both sides during the film forming process. That is, it is preferable to form an undercoat layer on one side or both sides of the substrate (see FIGS. 1 and 2). 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, and any of them can be preferably used. 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).

(Transparent hard coat layer: CHC layer)
The optical reflection films 1 and 1 ′ may further include a transparent hard coat layer (CHC layer) 16 on the outermost layer of the optical reflection film for the purpose of protecting the optical interference films 13a and 13b and the substrate 11 from scratches. Preferred (see FIGS. 1 and 2).

  Examples of the curable resin used in the CHC layer 16 include a thermosetting resin and an active energy ray curable resin, but an active energy ray curable resin is preferable because of easy molding. Such curable resins can be used singly 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.

  The active energy ray resin refers to a resin that is cured through a crosslinking reaction or the like by irradiation with active energy rays such as ultraviolet rays or electron beams. As the active energy ray curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and the active energy ray curable resin layer is cured by irradiation with an active energy ray such as an ultraviolet ray or an electron beam. Is formed. Typical examples of the active energy ray curable resin include an ultraviolet curable resin, an electron beam curable resin, and the like, and an ultraviolet curable resin that is cured by ultraviolet irradiation is preferable.

  As the ultraviolet curable resin, for example, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, or an ultraviolet curable epoxy resin is preferable. Used. Of these, ultraviolet curable acrylate resins are preferred.

  UV curable acrylic / urethane resins generally include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylate) in products obtained by reacting polyester polyols with isocyanate monomers or prepolymers. Only acrylate is indicated), and it can be easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate. For example, a mixture of 100 parts Unidic 17-806 (manufactured by Dainippon Ink Co., Ltd.) and 1 part of Coronate L (manufactured by Nippon Polyurethane Co., Ltd.) described in JP-A-59-151110 is preferably used. It is done.

  The UV curable polyester acrylate resin can be easily obtained by reacting a monomer such as 2-hydroxyethyl acrylate, glycidyl acrylate or acrylic acid with a hydroxyl group or carboxyl group at the end of the polyester (see, for example, JP-A No. 59-151112).

  The ultraviolet curable epoxy acrylate resin is obtained by reacting a terminal hydroxyl group of an epoxy resin with a monomer such as acrylic acid, acrylic acid chloride, or glycidyl acrylate.

  Examples of ultraviolet curable polyol acrylate resins include ethylene glycol (meth) acrylate, polyethylene glycol di (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipenta. Examples include erythritol pentaacrylate, dipentaerythritol hexaacrylate, and alkyl-modified dipentaerythritol pentaacrylate.

  Furthermore, as photosensitizers (radical polymerization initiators) for these resins, benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl methyl ketal and the like Alkyl ethers; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone (trade name Irgacure 184; BASF), 2-methyl-1 [4- (methylthio) phenyl] -2-mori Acetophenones such as folinopropan-1-one (trade name Irgacure 907; BASF); anthraquinones such as methylanthraquinone, 2-ethylanthraquinone and 2-amylanthraquinone; thioxanthone, 2,4-diethylthioxanthone, 2, 4-di Thioxanthones such as isopropyl thioxanthone; acetophenone dimethyl ketal, benzil ketals such as dimethyl ketal; can be used benzophenone, 4,4-bis benzophenones such as methylamino benzophenone and azo compounds. These may be used alone or in combination of two or more. In addition, tertiary amines such as triethanolamine and methyldiethanolamine; photoinitiators such as benzoic acid derivatives such as 2-dimethylaminoethylbenzoic acid and ethyl 4-dimethylaminobenzoate may be used in combination. it can. The amount of these radical polymerization initiators used 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.

  Examples of the thermosetting resin include inorganic materials typified by polysiloxane.

  The starting material of the polysiloxane hard coat layer (CHC layer 16) is represented by the general formula RmSi (OR ') n. R and R ′ represent an alkyl group having 1 to 10 carbon atoms, and m and n are integers satisfying the relationship of m + n = 4. Specifically, tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-polopoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, terapentaethoxy Silane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxy Silane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane, dimethylbutoxysilane, dimethyl Dimethoxysilane, dimethyl diethoxy silane, hexyl trimethoxy silane and the like. In addition, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-β- ( N-aminobenzylaminoethyl) -γ-aminopropylmethoxysilane / hydrochloride, γ-glycidoxypropyltrimethoxysilane, aminosilane, methylmethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloro Propyltrilimethoxysilane, hexamethyldisilazane, vinyltris (β-methoxyethoxy) silane, and octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride can also be used. A state in which a hydrolyzable group such as methoxy group or ethoxy group is substituted with a hydroxyl group is generally called a polyorganosiloxane hard coat. By applying this on a substrate and curing by heating, the dehydration condensation reaction is accelerated, and by curing and crosslinking, a hard coat layer (CHC layer 16) is formed. Among these polyorganosiloxane hard coats, those having an organic group that is not eliminated by hydrolysis are methyl groups have the highest weather resistance. Moreover, if it is a methyl group, since the methyl group is uniformly and densely distributed on the surface after the hard coat film formation, the falling angle is also low. Therefore, in this application, it is preferable to use methylpolysiloxane.

  If the polysiloxane hard coat layer (CHC layer 16) is too thick, there is a risk that the CHC layer 16 will break due to stress, and if it is too thin, the hardness cannot be maintained. Therefore, 1-5 micrometers is preferable as thickness, and it is preferable that it is 1.5-3 micrometers.

  Specific examples of the polyorganosiloxane-based hard coat layer (CHC layer 16) include Surcoat series (manufactured by Doken), SR2441 (Toray Dow Corning), KF-86 (Shin-Etsu Silicone), Perma-New (registered trademark). 6000 (California Hardcoating Company) or the like can be used.

  The blending amount of the cured resin in the CHC layer 16 is preferably 20 to 70% by mass and more preferably 30 to 50% by mass with respect to a total of 100% by mass (in terms of solid content) of the CHC layer 16. preferable.

  The thickness of the CHC layer 16 is preferably 0.1 to 20 μm, more preferably 1 to 15 μm, and more preferably 3 to 10 μm. If it is 0.1 μm or more, the hard coat property tends to be improved, and if it is 20 μm or more, the curl of the CHC layer 16 is large and the bending resistance tends to be lowered.

  The CHC layer 16 can be produced by applying a cured resin layer forming composition (coating solution) by wire bar coating, spin coating, or dip coating, and can also be produced by a dry film forming method such as vapor deposition. it can. The composition (coating liquid) can be applied and formed into a film by a continuous coating apparatus such as a die coater, a gravure coater, or a comma coater. In the case of polysiloxane hard coat, after application, after drying the solvent, heat treatment for 30 minutes to several days is required at a temperature of 50 ° C. or more and 150 ° C. or less in order to promote curing / crosslinking of the hard coat layer. And In consideration of the heat resistance of the coated substrate and the stability of the substrate when it is made into a roll, it is preferable to perform the treatment at 40 ° C. or more and 80 ° C. or less for 2 days or more. In the case of an active energy ray curable resin, the reactivity varies depending on the irradiation wavelength, the illuminance, and the light amount of the active energy ray, and therefore it is necessary to select an optimum condition depending on the resin to be used.

  The composition for forming the cured resin layer (coating liquid) may contain a solvent, or may be appropriately contained and diluted as necessary. Examples of the organic solvent contained in the coating solution include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), It can be appropriately selected from esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents, or a mixture thereof can be used.

  When adhesion to the lower layer of the CHC layer 16 is not obtained, an anchor layer (primer layer; not shown in FIGS. 1 and 2) can be formed before laminating the cured resin layer. The thickness of the anchor layer is not particularly limited, but is about 0.1 to 10 μm. Preferable examples of the resin constituting the anchor layer include polyvinyl acetal resin and acrylic resin.

{Production method of optical reflection film}
There is no restriction | limiting in particular about the manufacturing method of the optical reflection film of this invention, At least 1 unit comprised from a high-refractive-index layer and a low-refractive-index layer is formed on a base material (namely, a high-refractive-index layer and a low refractive index layer). Any method can be used as long as it can form an optical interference film in which refractive index layers are alternately laminated.

  In the method for producing an optical reflective film of the present invention, a unit composed of a high refractive index layer and a low refractive index layer is laminated on a base material. It is preferable to form a laminated body (optical interference film) by applying simultaneous multilayer coating to the refractive index layer and drying. More specifically, an optical reflective film comprising a high refractive index layer coating liquid and a low refractive index layer coating liquid simultaneously coated on a base material and dried, and then dried to provide an optical reflective film comprising the high refractive index layer and the low refractive index layer. The method of forming is preferred.

  As the coating method, for example, a curtain coating method, a slide bead coating method using a hopper described in U.S. Pat. Nos. 2,761,419 and 2,761,791, an extrusion coating method and the like are preferably used. It is done.

  The solvent for preparing the high refractive index layer coating solution and the low refractive index layer coating solution is not particularly limited, but water, an organic solvent, or a mixed solvent thereof is preferable. In consideration of environmental aspects due to the scattering of the organic solvent, water or a mixed solvent of water and a small amount of an organic solvent is more preferable, and water is particularly preferable.

  Examples of the organic solvent include alcohols such as methanol, ethanol, 2-propanol and 1-butanol, esters such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate, diethyl ether, Examples thereof include ethers such as propylene glycol monomethyl ether and ethylene glycol monoethyl ether, amides such as dimethylformamide and N-methylpyrrolidone, and ketones such as acetone, methyl ethyl ketone, acetylacetone and cyclohexanone. These organic solvents may be used alone or in combination of two or more. From the viewpoint of environment and simplicity of operation, the solvent of the coating solution is preferably water or a mixed solvent of water and methanol, ethanol, or ethyl acetate, and more preferably water.

  When using a mixed solvent of water and a small amount of an organic solvent, the content of water in the mixed solvent is preferably 80 to 99.9% by mass, based on 100% by mass of the entire mixed solvent, and 90 to 99%. More preferably, it is 5 mass%. Here, by setting it to 80% by mass or more, volume fluctuation due to solvent volatilization can be reduced, handling is improved, and by setting it to 99.9% by mass or less, homogeneity at the time of liquid addition is increased and stable. This is because the obtained liquid properties can be obtained.

  The concentration of the first water-soluble polymer (not including the photoreactive polymer compound) in the high refractive index layer coating solution is preferably 1 to 10% by mass. Moreover, it is preferable that the density | concentration of the 1st metal oxide particle in a high refractive index layer coating liquid is 1-50 mass%. Further, when the high refractive index layer contains a photocrosslinking polymer compound as a binder, the concentration of the photoreactive polymer compound in the high refractive index layer coating solution is 0.05 to 8% by mass. Preferably there is.

  The concentration of the second water-soluble polymer (not including the photoreactive polymer compound of the present invention) in the low refractive index layer coating solution is preferably 1 to 10% by mass. Moreover, it is preferable that the density | concentration of the 2nd metal oxide particle in a low refractive index layer coating liquid is 1-50 mass%. Furthermore, when the low refractive index layer contains a photocrosslinking polymer compound as a binder, the concentration of the photoreactive polymer compound in the low refractive index layer coating solution is 0.05 to 8% by mass. Preferably there is.

  The method for preparing the high refractive index layer coating solution and the low refractive index layer coating solution is not particularly limited. For example, metal oxide particles, water-soluble polymer (including the photoreactive polymer compound of the present invention), and necessary There may be mentioned a method in which other additives added according to the above are added and mixed with stirring. At this time, the order of addition of the respective components is not particularly limited, and the respective components may be sequentially added and mixed while stirring, or may be added and mixed at one time while stirring. If necessary, it is further adjusted to an appropriate viscosity using a solvent.

  In the present invention, it is preferable to form the high refractive index layer using an aqueous high refractive index layer coating solution prepared by adding and dispersing the first metal oxide particles. At this time, the first metal oxide particles of the present invention are added to the high refractive index layer coating liquid as a sol having a pH of 5.0 or more and 7.5 or less and a negative zeta potential of the particles. It is preferable to prepare them.

  When the slide bead coating method is used, the temperature of the high refractive index layer coating solution and the low refractive index layer coating solution in simultaneous multilayer coating is preferably a temperature range of 25 to 60 ° C, and a temperature range of 30 to 45 ° C. Is more preferable. Moreover, when using a curtain application | coating system, the temperature range of 25-60 degreeC is preferable, and the temperature range of 30-45 degreeC is more preferable.

  The viscosity of the high refractive index layer coating solution and the low refractive index layer coating solution when performing simultaneous multilayer coating is not particularly limited. However, when the slide bead coating method is used, 5 to 100 mPa.s within the preferable temperature range of the coating solution. in the range of 10 to 50 mPa.s. A range of s is more preferable. Further, when the curtain coating method is used, in the preferable temperature range of the coating liquid, 5 to 1200 mPa.s. in the range of 25 to 500 mPa.s. A range of s is more preferable. If it is the range of such a viscosity, simultaneous multilayer coating can be performed efficiently.

  Moreover, as a viscosity at 15 degreeC of a coating liquid, it is 100 mPa.s. s or more, preferably 100 to 30,000 mPa.s. s is more preferable, and more preferably 3,000 to 30,000 mPa.s. s, and most preferably 10,000 to 30,000 mPa.s. s.

  As a coating and drying method, the high refractive index layer coating solution and the low refractive index layer coating solution are heated to 30 ° C. or more and coated, and then the temperature of the formed coating film is temporarily cooled to 1 to 15 ° C. The drying is preferably performed at 10 ° C. or more, and 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.

  In the present invention, an optical reflection film (for example, a near infrared shielding film) used for an optical reflector (for example, a near infrared reflector) has a stacking order when having the above-described various functional layers. There is no particular limitation.

  For example, in the specification of applying a near-infrared shielding film as an optical reflecting film of the present invention on the indoor side of a window glass (internal bonding), an undercoat layer, an optical interference film, and an adhesive layer are laminated in this order on the substrate surface. Further, a preferred example is a mode (see FIG. 2) in which a transparent hard coat layer (CHC layer) is coated on the surface of the substrate opposite to the side where these layers are laminated (opposite side). It is done. Moreover, the form (refer FIG. 1) which coats an adhesion layer, an optical interference film | membrane, an undercoat layer, a base material, an optical interference film | membrane, and a hard-coat layer (CHC layer) is mentioned as a preferable example. Moreover, the order may be an adhesive layer, a base material, an optical interference film, and a hard coat layer (CHC layer), and may further have another functional layer, a base material, or an infrared absorber. Moreover, as an optical reflective film of the present invention on the outdoor side of a window glass, for example, a preferable example is a specification in which a near-infrared shielding film is pasted (outside pasting), an undercoat layer, an optical interference film, an adhesive on the substrate surface It is the structure which laminates | stacks in order of a layer, and coats a hard-coat layer (CHC layer) on the base-material surface on the opposite side (opposite side) to the side where these layers are laminated | stacked. As in the case of the internal bonding, an adhesive layer, an optical interference film, an undercoat layer, a substrate, an optical interference film, and a hard coat layer (CHC layer) may be applied. Furthermore, the order may be an adhesive layer, a substrate, an optical interference film, and a hard coat layer (CHC layer), and may further include another functional layer substrate or an infrared absorber.

{Optical reflector}
The optical reflection film provided by the optical reflection of the present invention can be applied to a wide range of fields. For example, a near-infrared shielding film (optical reflection film) that gives a near-infrared shielding (optical reflection) effect by bonding to equipment (base) that is exposed to sunlight for a long period of time, such as outdoor windows in buildings and automobile windows It is used mainly for the purpose of improving weather resistance, such as a film for window pasting, a film for agricultural greenhouses, and the like. In particular, the optical reflective film according to the present invention is suitable for a member that is bonded to a substrate such as glass or a glass substitute resin directly or via an adhesive.

  That is, 2nd Embodiment of this invention is an optical reflector (for example, near-infrared shielding body) which provides the optical reflection film which concerns on this invention in the at least one surface of a base | substrate. In such an optical reflector, the same effect is obtained by using an optical reflection film having improved weather resistance and water resistance while maintaining excellent optical reflection characteristics (that is, maintaining excellent optical reflection characteristics). In addition, an optical reflector having improved weather resistance and water resistance can be provided).

  Specific examples of the substrate include, for example, glass, polycarbonate resin, polysulfone resin, acrylic resin, polyolefin resin, polyether resin, polyester resin, polyamide resin, polysulfide resin, unsaturated polyester resin, epoxy resin, melamine resin, Examples thereof include phenol resin, diallyl phthalate resin, polyimide resin, urethane resin, polyvinyl acetate resin, polyvinyl alcohol resin, styrene resin, vinyl chloride resin, metal plate, ceramic and the like. The type of resin may be any of a thermoplastic resin, a thermosetting resin, and an ionizing radiation curable resin, and two or more of these may be used in combination. The substrate that can be used in the present invention can be produced by a known method such as extrusion molding, calendar molding, injection molding, hollow molding, compression molding and the like. The thickness of the substrate is not particularly limited, but is usually 0. 1 mm to 5 cm.

  An adhesive layer or an adhesive layer (which may be used as an adhesive layer or an adhesive layer 17 of a component of the optical reflective film as shown in FIGS. 1 and 2) for bonding the optical reflective film and the substrate to sunlight (heat ray) It is preferable to install on the incident surface side. In addition, it is preferable to sandwich the optical reflection film according to the present invention between a window glass and a substrate because it can be sealed from surrounding gas such as moisture and has excellent durability. Even if the optical reflective film according to the present invention is installed outdoors or outside a car (for external application), it is preferable because of environmental durability.

  As the adhesive used for the adhesive layer or the pressure-sensitive adhesive layer that bonds the optical reflective film and the substrate, an adhesive mainly composed of a photocurable or thermosetting resin can be used.

  As the adhesive (adhesive or adhesive) used for the adhesive layer or adhesive layer for bonding the optical reflective film and the substrate, those having durability against ultraviolet rays are preferable, and acrylic adhesives or silicone adhesives are preferable. . Furthermore, an acrylic adhesive is preferable from the viewpoint of adhesive properties and cost. In particular, a solvent system is preferable in the acrylic pressure-sensitive adhesive because the peel strength can be easily controlled. When a solution polymerization polymer is used as the acrylic solvent-based pressure-sensitive adhesive, known monomers can be used as the monomer.

  Moreover, you may use the polyvinyl butyral resin used as an intermediate | middle layer of a laminated glass, or ethylene-vinyl acetate copolymer type resin. Specifically, plastic polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., Mitsubishi Monsanto Co., Ltd.), ethylene-vinyl acetate copolymer (manufactured by DuPont, Takeda Pharmaceutical Co., Ltd., duramin), modified ethylene-vinyl acetate Copolymers (Mersen G manufactured by Tosoh Corporation) and the like. In addition, you may add and mix | blend an ultraviolet absorber, an antioxidant, an antistatic agent, a heat stabilizer, a lubricant, a filler, a coloring agent, an adhesion adjusting agent etc. suitably in a contact bonding layer.

  As the reflection performance of the optical reflection film or optical reflector with respect to a specific wavelength region such as sunlight (heat rays), for example, heat insulation performance and solar heat shielding performance are generally JIS R3209-1998 (multi-layer glass), JIS R3106. Obtained by a method based on 1998 (Testing method for transmittance, reflectance, emissivity, and solar heat gain of sheet glass) and JIS R3107-1998 (Calculation method for thermal resistance of sheet glass and heat transmissivity in buildings) Can do.

  The solar transmittance, solar reflectance, emissivity, and visible light transmittance are measured by (1) using a spectrophotometer having a wavelength (300 to 2500 nm) to measure the spectral transmittance and spectral reflectance of various single plate glasses. Further, the emissivity is measured using a spectrophotometer having a wavelength of 5.5 to 50 μm. In addition, a predetermined value is used for the emissivity of float plate glass, polished plate glass, mold plate glass, and heat ray absorbing plate glass. (2) The solar transmittance, solar reflectance, solar absorption rate, and modified emissivity are calculated in accordance with JIS R3106-1998 by calculating the solar transmittance, solar reflectance, solar absorption rate, and vertical emissivity. The corrected emissivity is obtained by multiplying the vertical emissivity by the coefficient shown in JIS R3107-1998. The heat insulation and solar heat shielding properties are calculated by (1) calculating the thermal resistance of the multilayer glass according to JIS R3209-1998 using the measured thickness value and the corrected emissivity. However, when the hollow layer exceeds 2 mm, the gas thermal conductance of the hollow layer is determined according to JIS R3107-1998. (2) The heat insulation is obtained by adding a heat transfer resistance to the heat resistance of the double-glazed glass and calculating the heat flow resistance. (3) The solar heat shielding property is calculated by obtaining the solar heat acquisition rate according to JIS R3106-1998 and subtracting it from 1.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

(Measurement of visible light transmittance and near infrared transmittance)
The transmittance | permeability in the 300 nm-2000 nm area | region of the optical reflection film samples 1-14 was measured using the spectrophotometer (The integrating sphere use, the Hitachi Ltd. make, U-4000 type | mold). The transmittance value at 550 nm was measured as the visible light transmittance, and the reflectance value at 1200 nm was measured as the near infrared reflectance. The measurement results are shown in Table 3 below.

(Xenon light resistance (weather resistance) test)
Each of the optical reflection film samples 1 to 14 was attached to blue glass having a thickness of 3 mm via an adhesive layer. This sample was exposed to xenon light having an intensity of 150 W / m ² for 100 hours using a xenon weather meter (manufactured by Suga Test Instruments Co., Ltd .; emitting light very close to sunlight) at 30 ° C. and 60% RH. And it was confirmed visually whether the film had cracked after exposure, and evaluated according to the following evaluation criteria. The evaluation results are shown in Table 3 below.

-Evaluation criteria of film cracking (cracking) by weather resistance test A: No film cracking occurred;
B: Slight film cracking occurred;
C: A film crack that can be sufficiently visually confirmed has occurred;
D: Membrane cracks are clearly generated in the entire film.

(Water resistance test)
Each of the optical reflection film samples 1 to 14 was attached to blue glass having a thickness of 3 mm via an adhesive layer. The sample was irradiated with xenon light having an intensity of 180 W / m 2 for 120 minutes using a xenon xenon weather meter (manufactured by Suga Test Instruments Co., Ltd .; emitting light very close to sunlight) under the conditions of 40 ° C. and 50% RH. Min water spray was repeated and exposed for 300 hours. And whether or not film peeling occurred on the film after exposure was visually confirmed and evaluated according to the following evaluation criteria. The evaluation results are shown in Table 3 below.

-Evaluation criteria for film peeling by water resistance test A: No film peeling occurred;
B: Slight peeling (less than 1% of the pasting area) is observed at the end;
C: Peel off at a rate of 1 to 10% of the pasting area;
D: Peel off at a rate exceeding 10% of the pasted area.

Example 1
<Preparation of UV polymerization type polyvinyl alcohol derivative aqueous solution 1>
According to the method described in Examples of JP-A No. 2000-181062, p- (3-methacryloxy-2-hydroxypropyloxy) benzaldehyde is reacted with polyvinyl alcohol having a polymerization degree of 3500 and a saponification degree of 88%, An aqueous solution 1 of an ultraviolet-polymerizable polyvinyl alcohol derivative having a structure represented by the formula (6) (crosslinking group modification rate: 1.2 mol%, solid content concentration: 4 mass%) was prepared.

<Preparation of UV polymerization type polyvinyl alcohol derivative aqueous solution 2>
In the same manner, except that the polyvinyl alcohol having a polymerization degree of 3500 and a saponification degree of 88% in the ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 1 is changed to a polyvinyl alcohol having a polymerization degree of 2400 and a saponification degree of 98.5% ( An aqueous solution 2 having a crosslinking group modification rate of 0.9 mol% and a solid content concentration of 4 mass% was prepared.

Production of optical reflection film 1 Production of reflection film (ICE configuration)
[Preparation of base material (transparent resin film)]
As a transparent resin film used for the base material, a polyethylene terephthalate film (A4300, double-sided easy-adhesion layer, thickness: 50 μm, length 200 m × width 330 mm, manufactured by Toyobo Co., Ltd., hereinafter abbreviated as PET film) was prepared. .

(Preparation of coating solution 1 for low refractive index layer)
Each constituent material shown in Table 1 below was added and mixed in this order at 45 ° C. in this order (in order from the top of Table 1), then finished to 1000 parts by mass with pure water, and used for the low refractive index layer. Coating solution 1 was prepared.

(Preparation of coating solution 1 for high refractive index layer)
A coating solution 1 for a high refractive index layer was prepared according to the following procedure.

<Preparation of silica-modified titanium oxide particle dispersion>
First, a dispersion of silica-modified titanium oxide particles was prepared according to the following method, and a solvent or the like was added thereto.

  A dispersion of silica-modified titanium oxide particles was prepared as follows.

The titanium sulfate aqueous solution was thermally hydrolyzed by a known method to obtain titanium oxide hydrate. The obtained titanium oxide hydrate was suspended in water to obtain 10 L of an aqueous suspension of titanium oxide hydrate (TiO ₂ concentration: 100 g / L). To this, 30 L of an aqueous sodium hydroxide solution (concentration 10 mol / L) was added with stirring, the temperature was raised to 90 ° C., and the mixture was aged for 5 hours. The obtained solution was neutralized with hydrochloric acid, filtered and washed with water to obtain a base-treated titanium compound.

Next, the base-treated titanium compound was suspended in pure water and stirred so that the TiO ₂ concentration was 20 g / L. Under stirring, it was added citric acid in an amount of 0.4 mol% with respect to TiO ₂ weight. The temperature was raised to 95 ° C., concentrated hydrochloric acid was added so that the hydrochloric acid concentration was 30 g / L, and the solution temperature was maintained, followed by stirring for 3 hours. Here, when the pH and zeta potential of the obtained mixed liquid were measured, the pH at 25 ° C. was 1.4, and the zeta potential was +40 mV. Further, when the particle size was measured by Zetasizer Nano (manufactured by Malvern), the volume average particle size was 35 nm and the monodispersity was 16%.

  1 kg of pure water was added to 1 kg of a 20.0 mass% titanium oxide sol aqueous dispersion containing rutile-type titanium oxide particles to prepare a 10.0 mass% titanium oxide sol aqueous dispersion.

2 kg of pure water was added to 0.5 kg of the 10.0 mass% titanium oxide sol aqueous dispersion, followed by heating to 90 ° C. Thereafter, 1.3 kg of an aqueous silicic acid solution having a SiO ₂ concentration of 2.0 mass% was gradually added. The obtained dispersion is subjected to a heat treatment at 175 ° C. for 18 hours in an autoclave, and further concentrated to thereby contain 20% by mass of silica-modified titanium oxide particles containing titanium oxide having a rutile structure coated with SiO _2. A dispersion (sol aqueous dispersion) was obtained.

<Preparation of coating solution>
The constituent materials shown in Table 2 below were sequentially added at 45 ° C. (in order from the top of Table 2) to the sol dispersion of silica-modified titanium oxide particles prepared above, and finally finished with pure water to 1000 parts by mass, A coating solution 1 for a high refractive index layer was prepared.

  Using a slide hopper type wet coating apparatus capable of 15-layer coating, the above-prepared coating solution 1 for the low refractive index layer and coating solution 1 for the high refractive index layer are kept on the transparent resin film while keeping the temperature at 40 ° C. Fifteen layers were applied. Immediately after coating each refractive index layer coating solution, cold air of 5 ° C. was blown and set. At this time, even if the surface was touched with a finger, the time until the finger was lost (set time) was 5 minutes. After completion of the setting, warm air of 80 ° C. was blown and dried to prepare an optical interference film (optical reflection layer) having 15 layers and a total thickness of 2.1 μm.

  At this time, in the 15-layer optical interference film, the lowermost layer (base material side) and the uppermost layer were low refractive index layers. In the configuration of the optical interference film of the optical reflection film (window pasting film) 1, a low refractive index layer and a high refractive index layer were alternately laminated.

The coating amount was adjusted so that the layer thickness during drying was 150 nm for each low refractive index layer and 130 nm for each high refractive index layer. In addition, each layer thickness was confirmed by cut | disconnecting the produced optical reflection film (film for window pasting) 1, and observing the cut surface with an electron microscope. At this time, when the interface between the two layers could not be clearly observed, the interface was determined by the XPS depth profile in the thickness direction of TiO ₂ contained in the layer obtained by the XPS surface analyzer.

(Formation of infrared absorbing nanoparticle layer)
With respect to the AZO dispersion (zinc antimonate fine particle dispersion; product name: Celnax CX-Z610M-F2, average particle size 15 nm, solvent: methanol, solid content 60% by mass, manufactured by Nissan Chemical Industries, Ltd.), methanol Dilute to an AZO concentration of 40% by mass, add KRM8495 (a mixture of acrylate-based cured resin and polymerization initiator, which is an ultraviolet curable hard coat agent), and a total solid content of 30% by mass. The coating solution 1 for forming an infrared absorbing nanoparticle layer was prepared by adjusting the AZO concentration to 50% by mass with respect to the solid content and 50% by mass of the cured resin (including a polymerization initiator). Using a gravure coater, the infrared absorbing nanoparticle layer forming coating solution 1 is applied to the opposite side through the optical interference film (optical reflection layer) and the substrate so that the dry film thickness becomes 1 μm. After drying at a drying zone temperature of 50 ° C. and a reduced rate drying zone temperature of 90 ° C., an irradiance is 100 mW / cm ² using an ultraviolet lamp and the irradiation amount is 0.2 J / cm ^2. Along with the absorbing nanoparticle layer, the low refractive index layer constituting the optical interference film and the UV-polymerized polyvinyl alcohol derivative (photoreactive polymer compound; photoreactive PVA) in the low refractive index layer are crosslinked, cured, and dried. An infrared absorption nanoparticle layer having a thickness of 1 μm was formed on the optical interference film.

(Formation of adhesive layer; production of optical reflection film 1)
100 parts by mass of an acrylic resin having a hydroxy group, MKC methyl silicate MS-56 (manufactured by Mitsubishi Chemical Corporation, tetramethyl silicate partial hydrolyzate condensate, average value of n = 10 (that is, average tetramer of tetramethoxysilane) 50 parts by mass, 1 part by mass of dibutyltin laurate, 700 parts by mass of xylene, and 150 parts by mass of isopropyl alcohol were mixed and stirred to prepare a resin mixture having a solid content of 10% by mass.

  The obtained resin mixture was mixed with 2.0 parts by mass of Tinuvin 477 (a UV absorber manufactured by BASF Japan Ltd.) to prepare a coating solution 1 for forming an adhesive layer.

  Using the prepared coating liquid 1 for forming an adhesive layer, it was coated on the optical interference film with a wire bar and dried. The film thickness of the adhesive layer after drying was 8 μm. A 25 μm thick polyester film (Therapel, manufactured by Toyo Metallizing Co., Ltd.) was bonded as a separator film to the surface of the pressure-sensitive adhesive layer of the film with the pressure-sensitive adhesive layer to produce an optical reflective film 1.

Example 2
(Preparation of optical reflection film 2)
In the production of the optical reflective film 1 of Example 1, an ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 2 which is a constituent material of the coating solution 1 for the high refractive index layer used for forming the high refractive index layer constituting the optical interference film is prepared. Instead, according to the method described in Examples of JP-A No. 2000-181062, polyvinyl alcohol having a polymerization degree of 2400 and a saponification degree of 98.5% was converted to p- (3-methacryloxy-2-hydroxypropyloxy). ) Except that benzaldehyde was reacted to prepare and use an aqueous solution 3 of an ultraviolet-polymerizable polyvinyl alcohol derivative (crosslinkable group modification rate 1.2 mol%, solid content concentration 4 mass%) having the structure represented by the above formula (6). Similarly, the optical reflection film 2 was produced.

Example 3
(Preparation of optical reflection film 3)
In the production of the optical reflective film 1 of Example 1, an ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 2 which is a constituent material of the coating solution 1 for the high refractive index layer used for forming the high refractive index layer constituting the optical interference film is prepared. Instead, according to the method described in Examples of JP-A No. 2000-181062, polyvinyl alcohol having a polymerization degree of 2400 and a saponification degree of 98.5% was converted to p- (3-methacryloxy-2-hydroxypropyloxy). ) Except that benzaldehyde was reacted to prepare and use an aqueous solution 4 of a UV-polymerized polyvinyl alcohol derivative (crosslinking group modification rate: 3.8 mol%, solid content concentration: 4 mass%) having the structure represented by the above formula (6). Similarly, an optical reflection film 3 was produced.

Example 4
(Preparation of optical reflection film 4)
In the production of the optical reflective film 1 of Example 1, an ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 2 which is a constituent material of the coating solution 1 for the high refractive index layer used for forming the high refractive index layer constituting the optical interference film is prepared. Instead, according to the method described in Examples of JP-A No. 2000-181062, polyvinyl alcohol having a polymerization degree of 2400 and a saponification degree of 98.5% was converted to p- (3-methacryloxy-2-hydroxypropyloxy). ) Except that benzaldehyde was reacted to prepare and use an aqueous solution 5 of a UV-polymerized polyvinyl alcohol derivative having a structure represented by the above formula (6) (crosslinking group modification rate: 4.2 mol%, solid content concentration: 4 mass%). Similarly, an optical reflection film 4 was produced.

Example 5
(Preparation of optical reflection film 5)
In the production of the optical reflective film 1 of Example 1, an ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 2 which is a constituent material of the coating solution 1 for the high refractive index layer used for forming the high refractive index layer constituting the optical interference film is prepared. Instead, according to the method described in Examples of JP-A-2000-181062, polyvinyl alcohol having a polymerization degree of 500 and a saponification degree of 98.5% was converted to p- (3-methacryloxy-2-hydroxypropyloxy). ) Except that benzaldehyde was reacted to prepare and use an aqueous solution 6 of a UV-polymerized polyvinyl alcohol derivative having a structure represented by the above formula (6) (crosslinking group modification rate 1.2 mol%, solid content concentration 4 mass%). Similarly, the optical reflection film 5 was produced.

Example 6
(Preparation of optical reflection film 6)
In the production of the optical reflective film 1 of Example 1, an ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 2 which is a constituent material of the coating solution 1 for the high refractive index layer used for forming the high refractive index layer constituting the optical interference film is prepared. Instead, according to the method described in Examples of JP-A No. 2000-181062, polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 98.5% was converted to p- (3-methacryloxy-2-hydroxypropyloxy). ) Except that benzaldehyde was reacted to prepare and use an aqueous solution 7 of a UV-polymerized polyvinyl alcohol derivative (crosslinkable group modification rate 1.2 mol%, solid content concentration 4 mass%) having the structure represented by the above formula (6). Similarly, an optical reflection film 6 was produced.

Example 7
(Preparation of optical reflection film 7)
In the production of the optical reflective film 1 of Example 1, an ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 1 which is a constituent material of the coating solution 1 for the low refractive index layer used for forming the low refractive index layer constituting the optical interference film is prepared. Instead of this, polyvinyl alcohol having a polymerization degree of 500 and a saponification degree of 88% was converted to p- (3-methacryloxy-2-hydroxypropyloxy) benzaldehyde according to the method described in the examples of JP-A No. 2000-181062. To prepare an aqueous solution 8 of an ultraviolet-polymerizable polyvinyl alcohol derivative having a structure represented by the above formula (6) (crosslinking group modification rate: 1.2 mol%, solid content concentration: 4 mass%), and further using an optical interference film Preparation of UV-polymerizable polyvinyl alcohol derivative aqueous solution 2 which is a constituent material of coating solution 1 for high refractive index layer used for forming the high refractive index layer constituting Instead to, in the same manner except for using an aqueous solution 3 ultraviolet polymerizable polyvinyl alcohol derivative prepared in Example 2, to produce an optical reflection film 7.

Example 8
(Preparation of optical reflection film 8)
In the production of the optical reflective film 1 of Example 1, an ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 1 which is a constituent material of the coating solution 1 for the low refractive index layer used for forming the low refractive index layer constituting the optical interference film is prepared. Instead of this, polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 88% was converted to p- (3-methacryloxy-2-hydroxypropyloxy) benzaldehyde according to the method described in the examples of JP-A-2000-181062. To prepare an aqueous solution 9 of a UV-polymerizable polyvinyl alcohol derivative having a structure represented by the above formula (6) (crosslinking group modification rate: 1.2 mol%, solid content concentration: 4% by mass), and further using an optical interference film UV-polymerizable polyvinyl alcohol derivative aqueous solution 2 which is a constituent material of coating solution 1 for high refractive index layer used for forming the high refractive index layer constituting Ete, in the same manner except for using an aqueous solution 3 ultraviolet polymerizable polyvinyl alcohol derivative prepared in Example 2, to produce an optical reflection film 8.

Example 9
(Preparation of optical reflection film 9)
In the production of the optical reflective film 1 of Example 1, an ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 1 which is a constituent material of the coating solution 1 for the low refractive index layer used for forming the low refractive index layer constituting the optical interference film is prepared. Instead of this, polyvinyl alcohol having a polymerization degree of 4500 and a saponification degree of 88% was converted to p- (3-methacryloxy-2-hydroxypropyloxy) benzaldehyde according to the method described in Examples of JP-A No. 2000-181062. To prepare an aqueous solution 10 of an ultraviolet-polymerizable polyvinyl alcohol derivative having a structure represented by the above formula (6) (crosslinking group modification rate 1.2 mol%, solid content concentration 4% by mass), and further using an optical interference film UV-polymerizable polyvinyl alcohol derivative aqueous solution 2 which is a constituent material of coating solution 1 for high refractive index layer used for forming the high refractive index layer constituting Varied, in the same manner except for using an aqueous solution 3 ultraviolet polymerizable polyvinyl alcohol derivative prepared in Example 2, to produce an optical reflection film 9.

Example 10
(Preparation of optical reflection film 10)
Among the constituent materials of the coating solution 1 for the low refractive index layer used for forming the low refractive index layer constituting the optical interference film in the production of the optical reflective film 1 of Example 1, the ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 1 150. 24 parts by mass (8% by mass in the binder) of 4 parts by mass of polyvinyl alcohol (4% by mass aqueous solution, PVA-235; polymerization degree: 3500; saponification degree: 88 mol%; manufactured by Kuraray Co., Ltd.) 150 parts by mass is changed to 276 parts by mass (ratio 92% by mass in the binder), and UV polymerization is a constituent material of the coating solution 1 for the high refractive index layer used for forming the high refractive index layer constituting the optical interference film. The optical reflective film 1 was prepared in the same manner except that the aqueous solution 3 of the UV-polymerized polyvinyl alcohol derivative prepared in Example 2 was used instead of the aqueous polyvinyl alcohol derivative solution 2. 0 was produced.

Example 11
(Preparation of optical reflection film 11)
Among the constituent materials of the coating solution 1 for the low refractive index layer used for forming the low refractive index layer constituting the optical interference film in the production of the optical reflective film 1 of Example 1, the ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 1 150. 90 parts by mass (ratio in the binder: 30% by mass), 4% by mass of polyvinyl alcohol (4% by mass aqueous solution, PVA-235; degree of polymerization: 3500; degree of saponification: 88 mol%; manufactured by Kuraray Co., Ltd.) 150 parts by mass is changed to 210 parts by mass (70% by mass in the binder), and UV polymerization is a constituent material of the coating solution 1 for the high refractive index layer used for forming the high refractive index layer constituting the optical interference film. In the same manner, except that the aqueous solution 3 of the UV-polymerized polyvinyl alcohol derivative prepared in Example 2 was used instead of the aqueous solution 2 of polyvinyl alcohol derivative, the optical reflective film 11 was produced.

Example 12
(Preparation of optical reflection film 12)
Among the constituent materials of the coating solution 1 for the low refractive index layer used for forming the low refractive index layer constituting the optical interference film in the production of the optical reflective film 1 of Example 1, the ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 1 150. Part by mass is 210 parts by mass (70% by mass in the binder) and 4% by mass of polyvinyl alcohol (4% by mass aqueous solution, PVA-235; degree of polymerization: 3500; degree of saponification: 88 mol%; manufactured by Kuraray Co., Ltd.) UV polymerization, which is a constituent material of the coating solution 1 for the high refractive index layer used for forming the high refractive index layer constituting the optical interference film, by changing 150 parts by mass to 90 parts by mass (ratio of 70% by mass in the binder). In the same manner, except that the aqueous solution 3 of the UV-polymerized polyvinyl alcohol derivative prepared in Example 2 was used instead of the aqueous solution 2 of polyvinyl alcohol derivative, the optical reflective film 12 was produced.

Comparative Example 1
(Preparation of optical reflection film 13)
Among the constituent materials of the coating solution 1 for the low refractive index layer used for forming the low refractive index layer constituting the optical interference film in the production of the optical reflective film 1 of Example 1, the ultraviolet polymerization type polyvinyl alcohol derivative aqueous solution 1 150. Part by mass is 0 part by mass (the ratio in the binder is 0% by mass), 4% by mass of polyvinyl alcohol (4% by mass aqueous solution, PVA-235; degree of polymerization: 3500; degree of saponification: 88 mol%; manufactured by Kuraray Co., Ltd.) 150 parts by mass is changed to 300 parts by mass (ratio in the binder is 100% by mass), and among the constituent materials of the coating liquid 1 for the high refractive index layer, 150 parts by mass of the UV-polymerized polyvinyl alcohol derivative aqueous solution 1 is 0 parts by mass ( 4 wt% polyvinyl alcohol (4 wt% aqueous solution, PVA-124, polymerization degree: 2400, saponification degree: 99 mol%) Except for changing the expression company Kuraray) 150 parts by weight of 300 parts by weight (ratio 100 wt% in the binder) in the same manner to produce an optical reflection film 13 for comparison.

  Using the optical reflective films 1 to 13 obtained in Examples 1 to 12 and Comparative Example 1, the above-described visible light transmittance and near infrared transmittance were measured before and after the above weather resistance test. Moreover, the above-mentioned weather resistance test was conducted, and film cracks (cracks) of the optical reflection films 1 to 13 after the test were observed and evaluated. Further, a water resistance test was performed, and the film peeling of the optical reflection films 1 to 13 after the test was observed and evaluated. These measurements and the evaluation results after the test are shown in Table 3 below.

  In Table 3 above, the reactive PVA of the low refractive index layer refers to an ultraviolet polymerizable polyvinyl alcohol derivative in an aqueous solution of an ultraviolet polymerizable polyvinyl alcohol derivative that is a constituent material of the coating solution for the low refractive index layer. The reactive PVA of the high refractive index layer refers to an ultraviolet polymerizable polyvinyl alcohol derivative in an aqueous solution of an ultraviolet polymerizable polyvinyl alcohol derivative that is a constituent material of the coating solution for the high refractive index layer.

  In Table 3 above, the “reactive binder ratio in binder (mass%)” of the low refractive index layer is the solid content (PVA) of a 4 mass% polyvinyl alcohol aqueous solution that is a constituent material in the coating liquid for the low refractive index layer. -235; Degree of polymerization: 3500; Degree of saponification: 88 mol%; Kuraray Co., Ltd .; non-reactive binder) and total amount of solid content (reactive binder) of UV-polymerizable polyvinyl alcohol derivative aqueous solution as reactive PVA (total amount) ) In the reactive binder (reactive PVA).

  In Table 3 above, “reactive binder ratio in binder (mass%)” of the high refractive index layer is the solid content (PVA) of 4 mass% polyvinyl alcohol aqueous solution which is a constituent material in the coating liquid for the high refractive index layer. -124, degree of polymerization: 2400, degree of saponification: 99 mol%, manufactured by Kuraray Co., Ltd .; non-reactive binder) and the total solid content (reactive binder) of the UV-polymerizable polyvinyl alcohol derivative aqueous solution which is reactive PVA (total amount) ) In the reactive binder (reactive PVA).

  In Table 3 above, the “polymerization degree”, “saponification degree”, and “modification rate (mol%)” of the reactive PVA of the low refractive index layer are reactive PVA that is a constituent material in the coating solution for the low refractive index layer. Represents the polymerization degree, saponification degree, and crosslinking group modification rate (mol%) of a certain UV-polymerized polyvinyl alcohol derivative (polymerization degree and saponification degree are reacted with p- (3-methacryloxy-2-hydroxypropyloxy) benzaldehyde. The degree of polymerization and the degree of saponification of the polyvinyl alcohol obtained according to the method described in the examples of JP-A No. 2000-181062 are the same.

  In Table 3 above, the “polymerization degree”, “saponification degree”, and “modification rate (mol%)” of the reactive PVA of the high refractive index layer are the reactive PVA that is a constituent material in the coating liquid for the high refractive index layer. Represents the polymerization degree, saponification degree, and crosslinking group modification rate (mol%) of a certain UV-polymerized polyvinyl alcohol derivative (polymerization degree and saponification degree are reacted with p- (3-methacryloxy-2-hydroxypropyloxy) benzaldehyde. The degree of polymerization and the degree of saponification of the polyvinyl alcohol obtained according to the method described in the examples of JP-A No. 2000-181062 are the same.

  In addition, in the low refractive index layer and the high refractive index layer in the optical reflective films of Examples and Comparative Examples, the reactive PVA (ultraviolet-polymerized polyvinyl alcohol derivative) in Table 3 is used when forming the infrared absorbing nanoparticle layer. In addition, a photocrosslinked PVA (binder) that is cross-linked between the side chains of the reactive PVA is formed by ultraviolet irradiation.

  From Table 3 above, the optical reflection film samples 1 to 12 of Examples 1 to 12 of the present invention are more visible light transmittance and near infrared reflectance before the test than the optical reflection film sample 13 of Comparative Example 1. Although there is no significant difference, there is a significant improvement and improvement effect in terms of visible light transmittance, near infrared reflectance and cracking (film cracking) after the weathering test, and film peeling after the water resistance test. I understand.

  Moreover, when it sees about the optical reflection film samples 1-12 of Examples 1-12, the reactive PVA of a high refractive index layer is more than Example 5 using the thing of polymerization degree 500 as reactive PVA of a high refractive index layer. As for Examples 2 and 6 using those having a polymerization degree of 1700 to 2400, significant improvement and improvement effects were observed with respect to cracks (film cracking) after the weather resistance test and film peeling after the water resistance test. Similarly, Examples 2 and 8 using those having a polymerization degree of 1700 to 4500 as the reactive PVA of the low refractive index layer than Example 7 using those having a polymerization degree of 500 as the reactive PVA of the low refractive index layer. 9 and the like show that a significant improvement and improvement effect can be seen with respect to film peeling after the water resistance test.

  Moreover, when it sees about the optical reflection film samples 1-12 of Examples 1-12, reaction of a low refractive index layer is more than Example 10 using the thing of the ratio of reactive PVA of a low refractive index layer to 8 mass%. In Examples 2, 11, 12 and the like using a PVA ratio of 30 to 70% by mass, significant improvements and improvements were observed in terms of cracks (film cracks) after the weather resistance test and film peeling after the water resistance test. It turns out that an effect is seen. In Examples 2, 11, and 12, the ratio of reactive PVA in the low refractive index layer is 50 to 50% more than that in Example 11 in which the ratio of reactive PVA in the low refractive index layer is 30% by mass. It can be seen that in Examples 2 and 12 using 70% by mass, significant improvement and improvement effects are observed with respect to film peeling after the water resistance test.

  Moreover, when it sees about the optical reflection film samples 1-12 of Examples 1-12, Examples 1-4 which used the thing of the modification | denaturation rate 0.9-4.2 of the side chain of the reactive PVA of a high refractive index layer. Thus, it can be seen that significant improvement and improvement effects can be seen with respect to visible light transmittance, near infrared reflectance and cracking (film cracking) after the weathering test, and film peeling after the water resistance test.

1, 1 'optical reflective film,
11 substrate,
12 Undercoat layer,
13a, 13b Multi-layer unit (9 layer multi-layer product),
14 low refractive index layer,
15 high refractive index layer,
16 Transparent hard coat layer (CHC layer),
17 Transparent adhesive layer,
18 substrate,
L Sunlight.

Claims (5)

A high refractive index layer containing a first water-soluble polymer and first metal oxide particles, and a low refractive index layer containing a second water-soluble polymer and second metal oxide particles on a substrate. In the optical reflection film having the optical interference film formed by alternately laminating,
At least one of the high refractive index layer and the low refractive index layer constituting the optical interference film is a polymer compound (hereinafter also referred to as a photoreactive polymer compound) that is cross-linked by active energy rays, and has a hydrophilic main property. Optical reflection characterized by containing as a binder a photocrosslinkable polymer compound obtained by irradiating active energy rays to the polymer compound having a plurality of side chains in the chain, which is crosslinked between the side chains the film. The partial structure of the hydrophilic main chain and side chain of the photoreactive polymer compound has the following general formula (A)
[In the formula, Poly represents a hydrophilic main chain, {} represents a side chain, X _l represents a (p + l) -valent linking group, B represents a crosslinkable group, and Y _l represents a hydrogen atom or a substituted group. Represents a group. m represents 0 or 1, n represents 0 or 1, and p represents a positive integer. When p is 2 or more, the plurality of B and Y _l may be the same or different. The optical reflective film according to claim 1, wherein   2. The hydrophilic main chain of the photoreactive polymer compound is a saponified product of polyvinyl acetate, having a saponification degree of 77 to 99% and a polymerization degree of 500 to 5,000. Or the optical reflection film of 2.   The modification rate of the side chain with respect to the hydrophilic main chain of the photoreactive polymer compound is in a range of 0.7 to 4.5 mol%, according to any one of claims 1 to 3. Optical reflective film.   An optical reflector formed by providing the optical reflective film according to any one of claims 1 to 4 on at least one surface of a substrate.