JP6724912B2 - Optical reflective film - Google Patents

Description

The present invention relates to an optical reflection film.

In general, a dielectric multilayer film in which a high refractive index layer and a low refractive index layer are laminated on the surface of a substrate by adjusting their optical thicknesses, respectively, can selectively reflect light of a specific wavelength. Are known. Such a dielectric multilayer film is used, for example, as an optical reflection film installed in windows of buildings, members for vehicles, and the like. Such an optical reflection film transmits visible light and selectively blocks near-infrared rays, but the reflection wavelength can be controlled only by adjusting the film thickness and refractive index of each layer. Can be reflected.

As a method for forming a laminated body such as a dielectric multilayer film, generally, there is a method of laminating by a dry film forming method, but the formation of the dielectric multilayer film by the dry film forming method requires a lot of manufacturing cost. , Not practical. As a practical method, for example, a method in which a coating solution containing a mixture of a water-soluble resin and metal oxide particles is applied by a wet application method and laminated is mentioned. In particular, the method of producing by simultaneous multi-layer coating of the coating liquid for the high refractive index layer and the coating liquid for the low refractive index layer is excellent in terms of cost.

However, it is known that water absorption and desorption easily occur in a laminated body in which a plurality of layers are formed by applying a coating solution containing a water-soluble resin and laminated. As each layer repeatedly contracts and expands due to water adsorption and desorption, cracks occur over time.

In order to improve the water resistance of a laminate containing a water-soluble resin, for example, in JP 2012-973A, a coating solution contains a cross-linking agent, and the water-soluble resin and the cross-linking agent are added at the interface between adjacent layers. There is disclosed a method in which the layers are brought into close contact with each other by cross-linking and to suppress the mixing of water.

As in JP 2012-973 A, by using a water-soluble resin in combination with a crosslinking agent, the water resistance of the laminate can be improved. However, in the method described in JP2012-973A, unreacted cross-linking agent remains after coating and drying the coating liquid, and thus the cross-linking agent reacts over time, resulting in shrinkage due to post-curing of the coating film. Occurs. As a result, it was found that the generation of cracks when exposed to a high humidity environment for a long period of time became worse. A high temperature of about 100° C. is required for the reaction so that the unreacted cross-linking agent does not remain, and this is not realistic because it exceeds the glass transition temperature of the resin substrate.

Therefore, the present invention has been made in view of the above circumstances, in the optical reflection film having a refractive index layer containing a water-soluble resin, coating film failure is less, optical cracking less even after long-term use It is intended to provide a reflective film.

As a result of intensive studies to solve the above problems, the present inventors have found that the object of the present invention can be achieved by adopting the following configuration.

That is, the said subject of this invention is solved by the following means.

1. Base material,
Arranged on one surface of the base material, a dielectric multilayer film in which a low refractive index layer and a high refractive index layer are alternately stacked,
At least one layer of the low-refractive index layer and the high-refractive index layer contains a water-soluble resin and a water-dispersible hydrophobic resin of 5 to 55% by mass based on the total mass of the water-dispersible hydrophobic resin. An optical reflection film, which is a containing layer.

2. 1. The water-dispersible hydrophobic resin-containing layer further contains an anionic surfactant, and the water-dispersible hydrophobic resin is an anionic emulsion resin. The optical reflection film described in 1.

3. In the dielectric multilayer film, the uppermost layer on the side opposite to the side in contact with the substrate is the water-dispersible hydrophobic resin-containing layer. Or 2. The optical reflection film described in 1.

4. In the dielectric multilayer film, the lowermost layer in contact with the base material is the water-dispersible hydrophobic resin-containing layer, 1. ~3. The optical reflection film according to any one of 1.

5. 1. The uppermost layer and the lowermost layer of the dielectric multilayer film are low refractive index layers, and all the low refractive index layers are the water-dispersible hydrophobic resin-containing layers. ~4. The optical reflection film according to any one of 1.

6. The average degree of polymerization of the water-soluble resin in the water-dispersible hydrophobic resin-containing layer is 4000 to 6000. ~5. The optical reflection film according to any one of 1.

7. A step of preparing a coating solution by dissolving or dispersing a water-soluble resin, an anionic surfactant, and an anionic emulsion resin in an aqueous solvent,
Forming the water-dispersible hydrophobic resin-containing layer by applying the coating liquid,
And 2. The method for producing an optical reflection film according to.

Embodiments of the present invention will be described below.

One embodiment of the present invention includes a base material and a dielectric multilayer film, which is disposed on one surface of the base material, in which a low refractive index layer and a high refractive index layer are alternately laminated. , At least one of the low refractive index layer and the high refractive index layer comprises a water-soluble resin and a water-dispersible hydrophobic resin in an amount of 5 to 55% by mass based on the total mass. It is an optical reflection film which is a resin-containing layer.

According to the present invention, in an optical reflection film having a refractive index layer containing a water-soluble resin, an optical reflection film having few coating film failures and less cracks even after long-term use can be obtained.

The optical reflection film of the present invention contains a water-soluble resin in at least one of the high refractive index layer and the low refractive index layer. Here, as described above, the optical reflection film containing a water-soluble resin has a problem that cracks occur over time.

Therefore, the present inventors have examined cracks in the optical reflection film, and by using a predetermined amount of a water-dispersible hydrophobic resin together with a water-soluble resin, the expansion and contraction of the refractive index layer are reduced. It has been found that it is possible to reduce the occurrence of cracks over time. When a water-dispersible hydrophobic resin is added to a water-soluble resin, when this resin is fused and formed into a film, a film having stronger hydrophobicity is obtained as compared with the case where the water-dispersible hydrophobic resin is not added. .. Therefore, it is considered that the expansion and contraction of the film due to the change in the amount of water in the atmosphere can be reduced, and the occurrence of cracks can be prevented. In addition, the inclusion of the emulsion resin can soften the coating film and reduce coating film failure. In particular, by combining an anionic surfactant and an anionic water-dispersible hydrophobic resin, the stability of the water-dispersible hydrophobic resin in the coating solution is increased and local aggregation etc. during drying of the coating film is suppressed. It is considered that the coating film failure can be further reduced.

Here, by setting the content of the water-dispersible hydrophobic resin to 5 to 55 mass% with respect to the total mass (solid content mass) of the water-dispersible hydrophobic resin-containing layer, an excellent crack prevention effect can be obtained. can get. Also, coating failure can be reduced. When the content of the water-dispersible hydrophobic resin is less than 5% by mass, the fusion between the water-dispersible hydrophobic resins is reduced and the effect of the present invention cannot be sufficiently obtained. On the other hand, when the content of the water-dispersible hydrophobic resin is more than 55% by mass, voids are easily formed with the water-soluble resin and the coating film haze is likely to increase. Further, when the content of the water-dispersible hydrophobic resin is more than 55% by mass, the viscosity of the coating solution is lowered during aqueous coating, particularly simultaneous simultaneous multilayer coating. Therefore, it is difficult to form a uniform coating film, and cracks easily occur over time. Also, coating film failure is likely to occur. Furthermore, due to the decrease in the viscosity of the coating liquid, the refractive index layers are mixed with each other, and haze is likely to occur. The content of the water-dispersible hydrophobic resin is preferably 10 to 40% by mass, more preferably 10 to 30% by mass based on the total mass of the water-dispersible hydrophobic resin-containing layer. When using two or more kinds of water-dispersible hydrophobic resins, the total amount thereof is adjusted to fall within the above range. When two or more water-dispersible hydrophobic resin-containing layers are included, the content of the water-dispersible hydrophobic resin in at least one layer may be in the above range, but it is more preferable that all layers are in the above range.

Hereinafter, the constituent elements of the optical reflection film of the present invention will be described in detail. In the following, 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”.

Further, in the present specification, “X to Y” indicating a range means “X or more and Y or less”. Unless otherwise specified, operations and measurements of physical properties are carried out under the conditions of room temperature (20 to 25°C)/relative humidity of 40 to 50%.

[Optical reflection film]
The optical reflection film according to the present invention comprises a base material, and a dielectric multilayer film which is disposed on one surface of the base material and in which a low refractive index layer and a high refractive index layer are alternately laminated. Have.

[Base material]
The optical reflection film according to the present invention includes a base material for supporting a dielectric multilayer film or the like. As the base material, various resin films can be used, and polyolefin films (polyethylene, polypropylene, etc.), polyester films (polyethylene terephthalate (PET), polyethylene naphthalate, etc.), polyvinyl chloride, cellulose acetate, etc. should be used. And a polyester film is preferable. The polyester film (hereinafter referred to as polyester) is not particularly limited, but a film-forming polyester containing a dicarboxylic acid component and a diol component as main constituents is preferable.

The main constituent dicarboxylic acid components include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylethane dicarboxylic acid, Examples thereof include cyclohexane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl thioether dicarboxylic acid, diphenyl ketone dicarboxylic acid, phenylindane dicarboxylic acid and the like. As the diol component, ethylene glycol, propylene glycol, tetramethylene glycol, cyclohexanedimethanol, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyethoxyphenyl)propane, bis( 4-hydroxyphenyl) sulfone, bisphenol full orange hydroxyethyl ether, diethylene glycol, neopentyl glycol, hydroquinone, cyclohexanediol and the like can be mentioned. Among the polyesters containing these as the main constituents, terephthalic acid or 2,6-naphthalenedicarboxylic acid as a dicarboxylic acid component and ethylene glycol or 1 as a diol component from the viewpoints of transparency, mechanical strength, dimensional stability and the like. Polyesters containing 4,4-cyclohexanedimethanol as a main constituent are preferred. Among them, polyesters containing polyethylene terephthalate or polyethylene naphthalate as a main constituent, copolymerized polyesters containing terephthalic acid, 2,6-naphthalenedicarboxylic acid and ethylene glycol, and mixtures of two or more of these polyesters Polyester as a constituent is preferable.

The thickness of the base material used in the present invention is preferably 10 to 300 μm, and particularly preferably 20 to 150 μm. In addition, two substrates may be stacked, and in this case, the types may be the same or different.

The base material preferably has a transmittance of 85% or more, particularly 90% or more, in the visible light region shown in JIS R3106-1998. When the base material has the above transmittance or more, it is advantageous in that the transmittance in the visible light region shown in JIS R3106-1998 when it is formed into a laminated film is 50% or more (upper limit: 100%), preferable.

Further, 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 improving strength and suppressing thermal expansion.

The base material can be manufactured by a conventionally known general method. For example, a resin as a material is melted by an extruder, extruded by an annular die or a T-die, and rapidly cooled to produce a substantially amorphous and unoriented unstretched substrate. Further, by a known method such as uniaxial stretching of the unstretched substrate, tenter sequential biaxial stretching, tenter simultaneous biaxial stretching, tubular simultaneous biaxial stretching, the flow direction of the substrate (vertical axis), or A stretched base material can be manufactured by stretching in a direction perpendicular to the flow direction of the base material (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.

[Dielectric multilayer film]
The dielectric multilayer film has a structure in which low-refractive index layers and high-refractive index layers are alternately laminated, and has at least one unit including a low-refractive index layer and a high-refractive index layer. Since the dielectric multilayer film is configured to include the refractive index layers having different refractive indexes as described above, at least a part of this light is input when light having a predetermined wavelength (for example, infrared light) is incident. It can be reflected to exert a shielding effect (and thus a heat shielding effect in the case of infrared light).

In this embodiment, whether the refractive index layer forming the dielectric multilayer film is the low refractive index layer or the high refractive index layer is determined by comparing the refractive index with the adjacent refractive index layer. Specifically, when a refractive index layer is used as a reference layer and the refractive index layer adjacent to the reference layer has a lower refractive index than the reference layer, the reference layer is a high refractive index layer (the adjacent layer has a low refractive index). It is determined to be a stratum). On the other hand, if the refractive index of the adjacent layer is higher than that of the reference layer, it is determined that the reference layer is the low refractive index layer (the adjacent layer is the high refractive index layer). Therefore, whether the refractive index layer is a high refractive index layer or a low refractive index layer is a relative one determined by the relationship with the refractive index of the adjacent layer, and a certain refractive index layer is different from the adjacent layer. Depending on the relationship, it can be a high refractive index layer or a low refractive index layer.

As the refractive index layer, at least one refractive index layer among the high refractive index layer and the low refractive index layer constituting the dielectric multilayer film is a water-soluble resin and 5 to the total mass of the refractive index layer. The water-dispersible hydrophobic resin-containing layer containing 55% by mass of the water-dispersible hydrophobic resin is not particularly limited, and a known refractive index layer used in the technical field can be used. As the known refractive index layer, for example, a refractive index layer formed by using a wet film forming method is preferably used from the viewpoint of production efficiency.

Furthermore, from the viewpoint of reflection characteristics, at least one of the high refractive index layer and the low refractive index layer preferably contains metal oxide particles, and both the high refractive index layer and the low refractive index layer contain metal oxide particles. Is more preferable.

Further, as described above, the water-soluble resin is used for at least one of the high refractive index layer and the low refractive index layer in the dielectric multilayer film of the optical reflection film of the present invention. The refractive index layer of the optical reflection film formed by the wet film forming method is preferably a coating film coated with a coating liquid containing a water-soluble resin (usually containing an aqueous solvent such as water). The water-soluble resin is preferable because it does not use an organic solvent, has a low environmental load, and has high flexibility, so that the durability of the film when bent is improved. The water-soluble resin is particularly preferably used when at least one layer of the high refractive index layer and the low refractive index layer contains metal oxide particles.

In the present specification, "water-soluble" means that the G2 glass filter (maximum pore size is 40 to 50 µm) when dissolved in water at a temperature at which the substance is most dissolved to have a concentration of 0.5% by mass. It means that the mass of the insoluble matter to be filtered out is within 50 mass% of the added polymer when filtered by.

As described above, whether the layer is a low refractive index layer or a high refractive index layer is a relative one that is determined by the relationship with the adjacent refractive index layer, and a certain refractive index layer is high in the low refractive index layer. Although it can serve as a refractive index layer, a typical structure of the high refractive index layer and the low refractive index layer among the refractive index layers that can be formed by the respective methods will be described below.

(High refractive index layer)
The high refractive index layer preferably contains a water-soluble resin. In addition, if necessary, metal oxide particles, a curing agent, a surfactant, and other additives may be included. The water-soluble resin and the metal oxide particles contained in the high refractive index layer will be referred to as “first water-soluble resin” and “first metal oxide particle”, respectively, for convenience sake.

At this time, the refractive index of the first metal oxide particles is preferably higher than the refractive index of the second metal oxide particles contained in the low refractive index layer described later. By including metal oxide particles in the high refractive index layer and/or the low refractive index layer, the refractive index difference between the respective refractive index layers can be increased, and the number of laminated layers can be reduced to increase the transparency of the film. It is preferable because it is possible. Further, there is an advantage that stress relaxation works and the physical properties of the film (flexibility at the time of bending and at high temperature and high humidity) are improved. The metal oxide particles may be contained in any of the refractive index layers, but a preferable form is that at least the high refractive index layer contains metal oxide particles, and a more preferable form is the high refractive index layer and the low refractive index layer. Each of the rate layers is in a form containing metal oxide particles.

(1) First Water-Soluble Resin The first water-soluble resin is not particularly limited, but polyvinyl alcohol resins, gelatin, celluloses, thickening polysaccharides, and polymers having a reactive functional group can be used. .. Among these, it is preferable to use polyvinyl alcohol resin.

Polyvinyl alcohol-based resin The polyvinyl alcohol-based resin includes ordinary polyvinyl alcohol (unmodified polyvinyl alcohol) obtained by hydrolyzing polyvinyl acetate, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, nonion-modified polyvinyl alcohol, vinyl alcohol. Examples include modified polyvinyl alcohol such as a system polymer. The modified polyvinyl alcohol may improve the adhesion, water resistance and flexibility of the film.

Gelatin As gelatin, various kinds of gelatin which have been widely used in the field of silver halide photographic light-sensitive materials can be applied. For example, acid-processed gelatin, alkali-processed gelatin, enzyme-processed gelatin that is enzymatically processed in the production process of gelatin, a group having an amino group, an imino group, a hydroxyl group or a carboxyl group as a functional group in a molecule and capable of reacting with it. Examples include gelatin derivatives and the like that have been modified by treatment with a reagent having

When gelatin is used, a gelatin hardener may be added if necessary.

Cellulose As the cellulose, 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, hydroxypropyl cellulose; carboxy group-containing celluloses such as carboxymethyl cellulose (cellulose carboxymethyl ether) and carboxyethyl cellulose; nitro Examples of the cellulose derivative include cellulose, cellulose acetate propionate, cellulose acetate, and cellulose sulfate ester.

Thickening Polysaccharides Thickening polysaccharides are polymers of saccharides and have a large number of hydrogen bonding groups in the molecule. The thickening polysaccharide has a characteristic that a difference in viscosity at low temperature and a difference in viscosity at high temperature are large due to a difference in hydrogen bonding force between molecules depending on temperature. In addition, when metal oxide particles are added to the thickening polysaccharide, the viscosity is thought to increase due to hydrogen bonding with the metal oxide particles at low temperature. Regarding the range of increase in viscosity, the viscosity at 15° C. is usually 1.0 mPa·s or more, preferably 5.0 mPa·s or more, and more preferably 10.0 mPa·s or more.

The thickening polysaccharide that can be used 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 “Biochemistry Dictionary (2nd Edition), Tokyo Kagaku Dojin Shuppan”, “Food Industry”, Vol. 31, (1988), page 21, and the like.

Polymers having reactive functional groups Examples of polymers having reactive functional groups include polyvinylpyrrolidones; polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic acid ester. Acrylic resins such as copolymers, acrylic acid-acrylic acid ester copolymers; styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylic acid ester copolymers, styrene-α -Methylstyrene-acrylic acid copolymer, styrene-acrylic acid resin such as styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer; styrene-sodium styrenesulfonate copolymer, styrene-2-hydroxyethyl acrylate Copolymer, styrene-2-hydroxyethyl acrylate-potassium styrenesulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinylnaphthalene-acrylic acid copolymer, vinylnaphthalene-malein Examples thereof include acid copolymers; vinyl acetate-maleic acid ester copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-acrylic acid copolymers and other vinyl acetate-based copolymers; and salts thereof. Of these, polyvinylpyrrolidones and copolymers containing them are preferably used.

The above water-soluble resins may be used alone or in combination of two or more.

The weight average molecular weight of the first water-soluble resin is preferably 1,000 to 200,000, and more preferably 3,000 to 40,000. In addition, in this specification, the value of "weight average molecular weight" shall adopt the value measured by gel permeation chromatography (GPC).

The content of the first water-soluble resin is preferably 5 to 50% by mass, and more preferably 10 to 40% by mass based on 100% by mass of the solid content of the high refractive index layer.

(2) First Metal Oxide Particles The first metal oxide particles are not particularly limited, but metal oxide particles having a refractive index of 2.0 to 3.0 are preferable. Specifically, titanium oxide, zirconium oxide, zinc oxide, alumina, colloidal alumina, lead titanate, red lead, yellow lead, zinc yellow, chromium oxide, ferric oxide, iron black, copper oxide, magnesium oxide, water. Examples thereof include magnesium oxide, strontium titanate, yttrium oxide, niobium oxide, europium oxide, lanthanum oxide, zircon and tin oxide. Among these, the first metal oxide particles are preferably titanium oxide or zirconium oxide from the viewpoint of forming a transparent high refractive index layer having a high refractive index, and the rutile type (tetragonal type) from the viewpoint of improving weather resistance. ) More preferably, it is titanium oxide.

Further, the titanium oxide may be in the form of core/shell particles coated with a silicon-containing hydrated oxide. The core-shell particles have a structure in which the surface of titanium oxide particles is coated with a shell made of hydrated oxide of silicon-containing titanium oxide serving as a core. At this time, the volume average particle diameter of the titanium oxide particles forming the core portion is preferably more than 1 nm and less than 30 nm, and more preferably 4 nm or more and less than 30 nm. By including such core/shell particles, the inter-layer mixing of the high refractive index layer and the low refractive index layer can be suppressed by the interaction between the hydrated oxide of silicon and the water-soluble resin of the shell layer. ..

The above-mentioned first metal oxide particles may be used alone or in combination of two or more.

The content of the first metal oxide particles is from 15 to 80% by mass based on 100% by mass of the solid content of the high refractive index layer, from the viewpoint of increasing the refractive index difference with the low refractive index layer. It is preferably 20 to 77% by mass, more preferably 30 to 75% by mass.

The volume average particle diameter of the first metal oxide particles is preferably 30 nm or less, more preferably 1 to 30 nm, and further preferably 5 to 15 nm. A volume average particle diameter of 30 nm or less is preferable because haze is small and the visible light transmittance is excellent. In the present specification, the value of “volume average particle diameter” is a value measured by the following method. Specifically, 1000 particles that appear on the cross section or surface of the refractive index layer are observed with an electron microscope to measure the particle size, and particles having a particle size of d1, d2... Di... Dk, respectively. In a group of metal oxide particles each having n1, n2... Ni... nk, the volume average particle diameter (mv) is calculated by the following formula, where vi is the volume per particle.

(3) Hardener The hardener has a function of reacting with the first water-soluble resin (preferably polyvinyl alcohol resin) contained in the high refractive index layer to form a hydrogen bond network.

The curing agent is not particularly limited as long as it causes a curing reaction with the first water-soluble resin, but is generally a compound having a group capable of reacting with the water-soluble resin or a different group contained in the water-soluble resin. Examples thereof include compounds that promote the reaction between them.

As a specific example, when a polyvinyl alcohol resin is used as the first water-soluble resin, boric acid and its salt are preferably used as the curing agent. Further, known curing agents other than boric acid and its salts may be used.

In addition, boric acid and its salt mean the oxyacid and its salt which have a boron atom as a central atom. Specific examples include orthoboric acid, diboric acid, metaboric acid, tetraboric acid, pentaboric acid, octaboric acid, and salts thereof.

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

Particularly, when the polyvinyl alcohol resin is used as the first water-soluble resin, the total amount of the curing agent used is preferably 1 to 600 mg per 1 g of the polyvinyl alcohol resin, and 10 to 600 mg per 1 g of the polyvinyl alcohol resin. Is more preferable.

Surfactant The surfactant is not particularly limited, but it is a zwitterionic surfactant, a cationic surfactant, an anionic surfactant, a nonionic surfactant, a fluorine surfactant and a silicone surfactant. Are listed. Among these, acrylic surfactants, silicone surfactants, or fluorine surfactants are used. As the surfactant, a surfactant containing a long chain alkyl group is preferable, and a surfactant having an alkyl group having 6 to 20 carbon atoms is more preferable.

As the zwitterionic surfactant, alkyl betaine, alkylamine oxide, cocamidopropyl betaine, lauramidopropyl betaine, palm kernel fatty acid amidopropyl betaine, cocoamphoacetate N, lauroamphoacetate Na, lauramidopropyl hydroxysultaine, lauramide. Examples include propylamine oxide, myristamide propylamine oxide, and hydroxyalkyl (C12-14) hydroxyethyl sarcosine.

Examples of cationic surfactants include alkylamine salts and quaternary ammonium salts.

Anionic surfactants are surfactants whose hydrophilic groups are ionized into anions in an aqueous solution, and examples of anionic surfactants include sulfate ester salts, sulfonate salts, carboxylate salts, and phosphate ester salts. To be For example, alkyl sulfate ester salt, polyoxyethylene alkyl ether sulfate ester salt, polyoxyethylene aryl ether sulfate ester salt, alkylbenzene sulfonate, fatty acid salt, polyoxyethylene alkyl ether phosphate, dipotassium alkenyl succinate may be used. .. As a commercially available anionic surfactant, for example, as a sulfate ester salt, Emal (registered trademark) manufactured by Kao Corporation, Hitenol (registered trademark) NF-08, NF-0825, NF- manufactured by Dai-ichi Kogyo Co., Ltd. 13, NF-17 (all of which are polyoxyethylene styrenated phenyl ether ammonium sulfate) and the like, and examples of the sulfonate include Neoperex (registered trademark) and Perex (registered trademark) manufactured by Kao Corporation. Examples of the carboxylic acid salt include Neohightenol (registered trademark) manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and examples of the phosphate ester salt include Plysurf (registered trademark) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. .. In the present invention, a sulfate ester salt or a sulfonate salt is preferable from the viewpoint of miscibility with the liquid.

Examples of nonionic surfactants include polyoxyethylene alkyl ethers (for example, Emulgen (registered trademark) manufactured by Kao Corporation), polyoxyethylene sorbitan fatty acid esters (for example, Leodol (registered trademark) TW series manufactured by Kao Corporation), and glycerin. Examples thereof include fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, and alkylalkanolamide. Alternatively, as the polyoxyethylene alkyl ether, polyoxyethylene mono-2-ethylhexyl ether, polyoxyethylene decyl ether (for example, Neugen (registered trademark) XL-40, XL-50, XL-60 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) Etc.) can also be used.

As the fluorine-based surfactant, Surflon S-211, S-221, S-231, S-241, S-242, S-243, S-420 (manufactured by AGC Seimi Chemical Co., Ltd.), Megafac F-114. , F-410, F-477, F-553 (manufactured by DIC Corporation), FC-430, FC-4430, FC-4432 (manufactured by 3M Company).

Examples of the silicon-based surfactant include BYK-345, BYK-347, BYK-348, and BYK-349 (manufactured by BYK Japan KK).

The high refractive index layer may also contain other additives. Examples of other additives include amino acids and lithium compounds. Further, the ultraviolet absorbers described in JP-A-57-74193, JP-A-57-87988, and JP-A-62-261476; JP-A-57-74192 and JP-A-57-87989. Anti-fading agents described in JP-A No. 60-72785, JP-A No. 61-146591, JP-A No. 1-95091, and JP-A No. 3-13376; Fluorescent brighteners described in JP-A No. 59-52689, JP-A No. 62-280069, JP-A No. 61-242871, and JP-A No. 4-219266; sulfuric acid, phosphoric acid , PH adjusting agents such as acetic acid, citric acid, sodium hydroxide, potassium hydroxide and potassium carbonate; antifoaming agents; lubricants such as diethylene glycol; preservatives; antifungal agents; antistatic agents; matting agents; heat stabilizers; Known additives such as antioxidants, flame retardants, crystal nucleating agents, inorganic particles, organic particles, viscosity reducing agents, lubricants, infrared absorbers, dyes, pigments and the like may be used as other additives.

(Low refractive index layer)
The low refractive index layer also preferably contains a water soluble resin. In addition, if necessary, metal oxide particles, a curing agent, a surfactant, and other additives may be included. The water-soluble resin and the metal oxide particles contained in the low refractive index layer are hereinafter referred to as "second water-soluble resin" and "second metal oxide particles", respectively, for convenience.

(1) Second Water-Soluble Resin As the second water-soluble resin, the same one as the first water-soluble resin can be used.

At this time, when the high refractive index layer and the low refractive index layer both use a polyvinyl alcohol-based resin as the first water-soluble resin and the second water-soluble resin, the polyvinyl alcohol-based resins having different saponification degrees are used. Is preferably used. Thereby, the mixing of the interface is suppressed, the reflectance (for example, the infrared reflectance (infrared shielding rate)) becomes better, and the haze can be lowered. In the present specification, the “saponification degree” means the ratio of hydroxy groups to the total number of acetyloxy groups (derived from vinyl acetate as a raw material) and hydroxy groups in the polyvinyl alcohol resin.

The content of the second water-soluble resin is preferably 3 to 60% by mass, and more preferably 10 to 45% by mass with respect to 100% by mass of the solid content of the low refractive index layer.

(2) Second Metal Oxide Particles The second metal oxide particles are not particularly limited, but it is preferable to use silica (silicon dioxide) such as synthetic amorphous silica or colloidal silica, and an acidic colloidal silica sol. Is more preferably used. From the viewpoint of further reducing the refractive index, hollow fine particles having pores inside the particles can be used as the second metal oxide particles, and it is particularly preferable to use hollow fine particles of silica (silicon dioxide). ..

The colloidal silica may have its surface cation-modified, or may be treated with Al, Ca, Mg, Ba or the like.

Moreover, the second metal oxide particles may be surface-coated with a surface-coating component.

The average particle diameter (number average; diameter) of the second metal oxide particles (preferably silicon dioxide) contained in the low refractive index layer of the present invention is preferably 3 to 100 nm, and 3 to 50 nm. Is more preferable. In the present specification, the "average particle size (number average; diameter)" of the metal oxide particles is 1,000 particles observed by observing the particles themselves or particles appearing on the cross section or surface of the refractive index layer with an electron microscope. The particle diameter of any of the particles is measured, and the simple average value (number average) is obtained. Here, the particle size of each particle is represented by the diameter assuming a circle equal to the projected area.

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 total solid content of the low refractive index layer. Is more preferable, and it is further preferable that it is 45 to 65 mass %.

From the viewpoint of adjusting the refractive index and the like, the above-mentioned second metal oxide may be used alone or in combination of two or more kinds.

Curing Agent, Surfactant, and Other Additives The curing agent, surfactant, and other additives may be the same as those used in the high refractive index layer, and therefore the description thereof is omitted here.

(Water-dispersible hydrophobic resin-containing layer)
In the optical reflection film of the present invention, as described above, at least one layer of the high refractive index layer and the low refractive index layer constituting the dielectric multilayer film is water containing a water-soluble resin and a water-dispersible hydrophobic resin. The dispersible hydrophobic resin-containing layer contains 5 to 55% by mass (solid content) of the water-dispersible hydrophobic resin with respect to the total mass (solid content) of the water-dispersible hydrophobic resin-containing layer.

The water-dispersible hydrophobic resin-containing layer may be a high refractive index layer or a low refractive index layer as long as it is a layer containing a water-soluble resin and a predetermined amount of the water-dispersible hydrophobic resin. As the water-dispersible hydrophobic resin-containing layer, the same structure as the high refractive index layer and the low refractive index layer described above is adopted, except that the water-dispersible hydrophobic resin described below is contained in a predetermined amount. Can be done. Generally, the water-dispersible hydrophobic resin has a low refractive index (about 1.5). Therefore, when the unfused water-dispersible hydrophobic resin remains, the haze may increase depending on the refractive index of the high refractive index layer. Because of concern, the water-dispersible hydrophobic resin-containing layer is preferably a low refractive index layer.

Further, in the optical reflection film of the present invention, at least one of the high refractive index layer and the low refractive index layer constituting the dielectric multilayer film may be a water-dispersible hydrophobic resin-containing layer, but preferably a base The lowermost layer in contact with the material or the uppermost layer on the side opposite to the substrate is the water-dispersible hydrophobic resin-containing layer. More preferably, all the low refractive index layers including the lowermost layer and the uppermost layer are water-dispersible hydrophobic resin-containing layers.

Water-Dispersible Hydrophobic Resin The water-dispersible hydrophobic resin applied to the present invention is formed by fusion of a hydrophobic polymer dispersed in an aqueous solvent at the time of forming the refractive index layer in the production process of the optical reflection film. Resin.

The water-dispersible hydrophobic resin may be an emulsion resin. The emulsion resin is a resin in which fine resin particles having an average particle size of 2.0 μm or less are dispersed in an aqueous medium in an emulsion state, and an oil-soluble monomer such as a polymer dispersant is used. It is obtained by emulsion polymerization using a dispersant.

The oil-soluble monomers that can be used are not particularly limited, but include ethylene, propylene, butadiene, vinyl acetate and partial hydrolysates thereof, vinyl ether, acrylic acid and its esters, methacrylic acid and its esters, acrylamide and its derivatives, Methacrylamide and its derivatives, styrene, divinylbenzene, vinyl chloride, vinylidene chloride, maleic acid, vinylpyrrolidone, diisocyanates such as 1,6-hexamethylene diisocyanate, polyisocyanates, diols, polyols, dicarboxylic acids and the like. To be

The dispersant that can be used is not particularly limited, and examples thereof include low molecular weight dispersants such as alkyl sulfonates, alkylbenzene sulfonates, diethylamine, ethylenediamine, and quaternary ammonium salts, and polyoxyethylene nonyl. Polymer dispersants such as phenyl ether, poly(ethylene ethylene lauric acid ether), hydroxyethyl cellulose, polyvinylpyrrolidone are mentioned.

Examples of the above-mentioned emulsion-polymerizable resin include acrylic resin, styrene-butadiene resin, ethylene-vinyl acetate resin, urethane resin, phenol resin, acrylic ester resin and the like.

As the emulsion resin, a commercially available one may be used, for example, Movinyl 718A, 710A, 731A, LDM7582, 5450, 6960 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Superflex (registered trademark) 150, 170, 300, 500M (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), ADEKA BONTITER HUX-232, HUX-380, HUX-386, HUX-830, HUX-895 (manufactured by ADEKA CORPORATION), AE-116, AE-120A, AE-200A, AE-336B, AE-981A, AE-986B (manufactured by E-Tech Co., Ltd.), ETERNACOLL UW-1005E, UW-5002, UW-5034E, UE-5502 (manufactured by Ube Industries, Ltd.), and Akrit UW-. 309, UW-319SX, UW-520 (manufactured by Taisei Fine Chemical Co., Ltd.) and the like.

As the emulsion resin, any of an anionic emulsion resin, a cationic emulsion resin, and a nonionic emulsion resin can be used. In the water-dispersible hydrophobic resin-containing layer in the optical reflection film of the present invention, an anionic emulsion resin is used. It is preferable to use it in combination with an anionic surfactant.

In an application liquid in which inorganic particles such as metal oxide particles, a water-soluble resin, and a surfactant are dispersed in an aqueous solvent, an anionic emulsion resin is added, and an anionic surfactant is used as a surfactant. It is considered that the structural viscosity of the coating liquid is stabilized, the dispersed state is improved, and the increase in viscosity is suppressed. As a result, coating failure, especially streaky coating failure, can be dramatically improved and product yield can be significantly improved.

Here, as the anionic emulsion resin, anionic urethane emulsion resin, anionic acrylic emulsion resin, anionic styrene-acrylic copolymer emulsion resin and the like can be preferably used. As the anionic surfactant, the same ones as described above can be used.

The particle size of the emulsion resin is not particularly limited, but the average particle size is preferably 1 to 100 nm, more preferably 5 to 60 nm. When the emulsion resin has the above average particle diameter, the haze of the obtained optical reflection film can be reduced and the transparency can be improved. The average particle size of the emulsion resin can be measured by the dynamic light scattering method.

The refractive index of the emulsion resin is also not particularly limited, but it is preferably 1.3 to 1.7, and more preferably 1.4 to 1.6. Within the above range, the refractive index of the water-soluble resin is close to that of the water-soluble resin, so that the haze of the obtained optical reflection film can be reduced.

From the viewpoint of enhancing flexibility, the above-mentioned emulsion resin preferably has a glass transition temperature (Tg) of 20°C or lower, more preferably -30 to 10°C.

Metal Oxide Particles The water-dispersible hydrophobic resin-containing layer may include metal oxide particles. The same metal oxide particles as those used for the high refractive index layer and the low refractive index layer can be used.

Water-Soluble Resin The water-dispersible hydrophobic resin-containing layer in the optical reflection film of the present invention contains a water-soluble resin. As the water-soluble resin, the same materials as those used for the high refractive index layer and the low refractive index layer can be used.

The average degree of polymerization of the water-soluble resin in the water-dispersible hydrophobic resin-containing layer is preferably 1500 to 6000, more preferably 4000 to 6000. The average degree of polymerization of the water-soluble resin in the water-dispersible hydrophobic resin-containing layer is more preferably 4000 to 5000, still more preferably 4500 to 5000. When the average degree of polymerization of the water-soluble resin is 1500 or more, it is possible to prevent the water-soluble resin from diffusing and generating haze even when the water-soluble resin is applied by the simultaneous multilayer coating method. Further, if the average degree of polymerization of the water-soluble resin is 6000 or less, the viscosity of the coating solution does not become too high, and thus it is suitable for producing a dielectric multilayer film by coating. In the case of having a plurality of water-dispersible hydrophobic resin-containing layers, the average degree of polymerization of the water-soluble resin in at least one water-dispersible hydrophobic resin-containing layer is preferably within the above range, The average degree of polymerization of the water-soluble resin in the resin-containing layer is more preferably within the above range.

The water-soluble resin in the water-dispersible hydrophobic resin-containing layer is preferably a polyvinyl alcohol-based resin. This stabilizes the dispersibility of the water-dispersible hydrophobic resin and can suppress the increase in haze. The saponification degree of the polyvinyl alcohol-based resin is, for example, 70 to 99.5 mol%, preferably 80 to 95 mol%, and more preferably 85 to 90 mol% from the viewpoint of further suppressing haze. .. The average degree of polymerization of the water-soluble resin is a viscosity average degree of polymerization, and the average degree of polymerization of the polyvinyl alcohol resin can be measured according to Japanese Industrial Standard JIS K6726:1994.

Further, in a preferred embodiment of the present invention, among the refractive index layers constituting the dielectric multilayer film, the uppermost layer on the side opposite to the side in contact with the base material is the water-dispersible hydrophobic resin-containing layer. More preferably, at this time, the average degree of polymerization of the water-soluble resin in the water-dispersible hydrophobic resin-containing layer is 4000 to 6000. The average degree of polymerization of the water-soluble resin in the water-dispersible hydrophobic resin-containing layer is more preferably 4000 to 5000, still more preferably 4500 to 5000. At this time, if the water-dispersible hydrophobic resin-containing layer contains an anionic emulsion resin and an anionic surfactant, the effect of the present invention can be more remarkably obtained.

As described above, in the optical reflection film of the present invention, at least one of the high refractive index layer and the low refractive index layer constituting the dielectric multilayer film may be a water-dispersible hydrophobic resin-containing layer, When the uppermost layer of the dielectric multilayer film is used as an optical reflector by being adhered to a substrate such as glass through an adhesive layer, for example, when expansion and contraction of the layer due to adsorption and desorption of moisture in the environment occur, The stress associated therewith tends to concentrate. Therefore, it is effective to arrange the water-dispersible hydrophobic resin-containing layer capable of suppressing the adsorption and desorption of moisture in the environment in the uppermost layer in order to improve the weather resistance of the optical reflection film.

When a dielectric multilayer film is produced by applying a coating solution containing a water-soluble resin, if the average degree of polymerization of the water-soluble resin is, for example, 1500 or more, preferably 4000 or more Even if it exists, it is possible to prevent the water-soluble resin from diffusing and generating haze. Further, if the average degree of polymerization of the water-soluble resin is 6000 or less, the viscosity of the coating solution does not become too high, and thus it is suitable for producing a dielectric multilayer film by coating. More preferably, the average degree of polymerization of the water-soluble resin is 4000 to 5000, and further preferably 4500 to 5000.

Further, in a further preferred embodiment of the present invention, among the refractive index layers constituting the dielectric multilayer film, the lowermost layer in contact with the base material is the water-dispersible hydrophobic resin-containing layer. The lowermost layer of the dielectric multilayer film is a layer in which stress accompanying the expansion and contraction of the layer due to adsorption and desorption of environmental moisture tends to concentrate in comparison with the inner layer, so the lowermost layer is A water-dispersible hydrophobic resin-containing layer is preferred. More preferably, both the uppermost layer and the lowermost layer are water-dispersible hydrophobic resin-containing layers. At this time, if the water-dispersible hydrophobic resin-containing layer contains an anionic emulsion resin and an anionic surfactant, the effect of the present invention can be more remarkably obtained.

In a preferred embodiment of the present invention, the uppermost layer and the lowermost layer of the dielectric multilayer film are low refractive index layers, and all the low refractive index layers are water-dispersible hydrophobic resin-containing layers. By doing so, it is possible to further reduce the adsorption and desorption of water due to the fluctuation of the water content in the environment in the dielectric multilayer film using the water-soluble resin. If so, the occurrence of cracks can be further reduced. At this time, when the average degree of polymerization of the water-soluble resin in the water-dispersible hydrophobic resin-containing layer is 4000 to 6000, even if all the low refractive index layers contain the water-dispersible hydrophobic resin, the haze is increased. Is less likely to occur.

The thickness of the water-dispersible hydrophobic resin-containing layer is not particularly limited, but when the water-dispersible hydrophobic resin-containing layer is a high refractive index layer, the thickness per layer thereof is 20 to 800 nm. It is more preferably 50 to 500 nm. When the water-dispersible hydrophobic resin-containing layer is a low refractive index layer, its thickness per layer is preferably 20 to 800 nm, more preferably 50 to 500 nm.

[optical properties]
When the optical reflection film according to the present invention is an infrared shielding film that reflects infrared light, it is possible to design a large difference in the refractive index between the low refractive index layer and the high refractive index layer, with a small number of layers. It is preferable from the viewpoint that the infrared reflectance can be increased. In this embodiment, in at least one of the laminated units composed of the low refractive index layer and the high refractive index layer, the refractive index difference between the adjacent low refractive index layer and high refractive index layer is 0.1 or more. It is preferably 0.3 or more, more preferably 0.35 or more, particularly preferably 0.4 or more. When a plurality of laminates of the high refractive index layer and the low refractive index layer are provided, it is preferable that the difference in the refractive index between the high refractive index layer and the low refractive index layer in all the laminated bodies is within the above-mentioned preferable range. However, even in this case, the refractive index layers constituting the uppermost layer and the lowermost layer of the dielectric multilayer film may be out of the preferable range described above.

As the optical characteristics of the optical reflection film of the present embodiment, the transmittance in the visible light region shown in JIS R3106-1998 is preferably 50% or more, more preferably 75% or more, further preferably 85% or more. is there. In addition, it is preferable to have a region with a reflectance of more than 50% in a wavelength region of 900 nm to 1400 nm.

From the above viewpoint, the number of refractive index layers of the dielectric multilayer film (total number of high refractive index layers and low refractive index layers) is, for example, 6 to 500 layers, and 6 to 300 layers. Is preferred. In particular, when it is produced by a wet film forming method, it is preferably 6 to 50 layers, more preferably 8 to 40 layers, further preferably 9 to 30 layers, and 11 to 31 layers. Is particularly preferable. When the number of refractive index layers of the dielectric multilayer film is in the above range, excellent heat shielding performance and transparency, suppression of film peeling and cracking, and the like can be realized, which is preferable. When the dielectric multilayer film has a plurality of high refractive index layers and/or low refractive index layers, each high refractive index layer and/or each low refractive index layer may be the same or different. It may be one.

The thickness of each high refractive index layer is preferably 20 to 800 nm, more preferably 50 to 500 nm. Further, the thickness of each low refractive index layer is preferably 20 to 800 nm, more preferably 50 to 500 nm.

Here, when the thickness per layer is measured, the composition may change continuously without a clear interface at the boundary between the high refractive index layer and the low refractive index layer. In the interface region where the composition changes continuously, when the maximum refractive index−the minimum refractive index=Δn, the point of the minimum refractive index+Δn/2 between the two layers is regarded as the layer interface.

When the high refractive index layer and the low refractive index layer contain metal oxide particles, the above composition can be observed from the concentration profile of the metal oxide particles. The metal oxide concentration profile was obtained by performing etching from the surface to the depth direction using a sputtering method, and using an XPS surface analyzer, setting the outermost surface to 0 nm and performing sputtering at a rate of 0.5 nm/min to obtain an atomic composition. It can be seen by measuring the ratio. Alternatively, the laminated film may be cut and the cut surface may be confirmed by measuring the atomic composition ratio with an XPS surface analyzer.

The XPS surface analyzer is not particularly limited, and any model can be used. As the XPS surface analyzer, for example, ESCALAB-200R manufactured by VG Scientific Co., Ltd. can be used. Mg is used for the X-ray anode, and the output is measured at 600 W (accelerating voltage 15 kV, emission current 40 mA).

[Adhesive layer]
The optical reflection film according to the present invention may have an adhesive layer. This pressure-sensitive adhesive layer is usually provided on the surface of the dielectric multilayer film opposite to the substrate, and a known release paper or separator may be further provided. The constitution of the adhesive layer is not particularly limited and, for example, any of dry laminating agent, wet laminating agent, adhesive agent, heat sealing agent, hot melt agent and the like can be used.

As the adhesive, for example, a polyester adhesive, a urethane adhesive, a polyvinyl acetate adhesive, an acrylic adhesive, a nitrile rubber or the like is used.

The optical reflection film of the present invention, when attached to a window glass, spraying water on the window, a method of attaching the adhesive layer of the optical reflection film to the glass surface in a wet state, a so-called water attaching method is reattached, repositioned, etc. It is preferably used from the viewpoint of. Therefore, an acrylic pressure-sensitive adhesive, which has a weak adhesive force in the presence of water under a wet condition, is preferably used.

The acrylic pressure-sensitive adhesive to be used may be either solvent-based or emulsion-based, but solvent-based pressure-sensitive adhesives are preferable because they easily enhance the adhesive force and the like, and among them, those obtained by solution polymerization are preferable. As a raw material in the case of producing such a solvent-based acrylic pressure-sensitive adhesive by solution polymerization, for example, as a main monomer serving as a skeleton, an acrylic acid ester such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, or ocryyl acrylate, As a comonomer to improve cohesive strength, vinyl acetate, acrylonitrile, styrene, methyl methacrylate, etc., to further promote cross-linking and impart stable adhesive strength, and to maintain some adhesive strength even in the presence of water Examples of the functional group-containing monomer include methacrylic acid, acrylic acid, itaconic acid, hydroxyethyl methacrylate, glycidyl methacrylate and the like. For the adhesive layer, a polymer having a low glass transition temperature (Tg), such as butyl acrylate, is particularly useful as the main polymer because it requires particularly high tackiness.

Examples of commercial products of the acrylic pressure-sensitive adhesive include COPONYL (registered trademark) series (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the like.

This adhesive layer contains additives such as stabilizers, surfactants, ultraviolet absorbers, flame retardants, antistatic agents, antioxidants, heat stabilizers, lubricants, fillers, coloring agents, adhesion control agents, etc. It can also be done. In particular, when used for window sticking, the addition of an ultraviolet absorber is also effective for suppressing the deterioration of the optical reflection film due to ultraviolet rays.

The method for applying the pressure-sensitive adhesive is not particularly limited, and any known method can be used, for example, bar coating method, die coater method, comma coating method, gravure roll coater method, blade coater method, spray coater method, The air knife coating method, the dip coating method, the transfer method and the like are preferably mentioned, and they can be used alone or in combination, but the continuous rolling method is preferable from the viewpoint of economy and productivity. These can be appropriately applied by using a coating solution in which the pressure-sensitive adhesive can be dissolved in a solvent or dispersed, and known solvents can be used.

Further, the thickness of the adhesive layer is preferably in the range of usually about 1 to 100 μm from the viewpoint of the adhesive effect, the drying speed, and the like.

The adhesive strength is preferably a peel strength of 2 to 30 N/25 mm, more preferably 4 to 20 N/25 mm, as measured by a 180° peel test described in JIS K6854.

The adhesive layer may be formed by directly coating the dielectric multilayer film by the above coating method, or by coating the release film once and drying it, and then laminating the dielectric multilayer film. The adhesive may be transferred. The drying temperature at this time is preferably such that the residual solvent is as low as possible. For that purpose, the drying temperature and time are not specified, but preferably a temperature of 50 to 150° C. and a drying time of 10 seconds to 5 minutes are provided. Is good.

[Hard coat layer]
The optical reflection film of the present invention may be laminated with a hard coat layer containing a resin curable by heat, ultraviolet rays or the like as a surface protective layer for enhancing scratch resistance. For example, a preferred example is a mode in which a dielectric multilayer film and an adhesive layer are laminated in this order on the substrate surface, and a hard coat layer is coated on the substrate surface on the side opposite to the side on which these layers are laminated. Can be mentioned.

Examples of the curable resin used in the hard coat layer include a thermosetting resin and an ultraviolet curable resin, but an ultraviolet curable resin is preferable because it is easy to mold, and among them, a pencil hardness of at least 2H is preferable. More preferable. Such curable resins may be used alone or in combination of two or more.

Examples of the ultraviolet curable resin include (meth)acrylate, urethane acrylate, polyester acrylate, epoxy acrylate, epoxy resin, and oxetane resin, and these can also be used as a solventless resin composition.

When the above ultraviolet curable resin is used, it is preferable to add a photopolymerization initiator to accelerate curing.

As the photopolymerization initiator, acetophenones, benzophenones, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, thiuram compounds, fluoroamine compounds Are used. Specific examples of the photopolymerization initiator include 2,2′-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 1-hydroxydimethyl phenyl ketone, 2-methyl-4′-methylthio-2-molybdenum. Acetophenones such as holinopropiophenone and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone 1, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyl dimethyl retinal. Benzoins, benzophenone, 2,4'-dichlorobenzophenone, 4,4'-dichlorobenzophenone, benzophenones such as p-chlorobenzophenone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, anthraquinones, thioxanthones, etc. .. These photopolymerization initiators may be used alone, in combination of two or more, or in the form of eutectic mixture. In particular, it is preferable to use acetophenones because of the stability of the curable composition and the polymerization reactivity.

As such a photopolymerization initiator, a commercially available product may be used, and preferred examples thereof include IRGACURE (registered trademark) 819, 184, 907 and 651 manufactured by BASF Japan Ltd.

The thickness of the hard coat layer is preferably 0.1 to 50 μm, and more preferably 1 to 20 μm from the viewpoint of improving hard coat properties and improving transparency of the optical reflection film.

The method for forming the hard coat layer is not particularly limited. For example, after preparing a hard coat layer coating liquid containing the above components, the coating liquid is coated with a wire bar or the like, and the coating liquid is cured by heat and/or UV. , A method of forming a hard coat layer, and the like.

[Other layers]
The optical reflection film according to the present invention may have layers (other layers) other than the above-mentioned layers. For example, an intermediate layer can be provided as the other layer. Here, the “intermediate layer” means a layer between the base material and the dielectric multilayer film, or a layer between the base material and the hard coat layer. Examples of the constituent material of the intermediate layer include a polyester resin, a polyvinyl alcohol resin, a polyvinyl acetate resin, a polyvinyl acetal resin, an acrylic resin, and a urethane resin. A material having a low additive compatibility and a low Tg is preferable. Either may be used as long as it satisfies the conditions. The glass transition temperature (Tg) of the intermediate layer is preferably 30 to 120° C., because sufficient weather resistance can be obtained, and more preferably 30 to 90° C.

[Method for producing optical reflection film]
The method for producing the optical reflection film of the present invention is not particularly limited, and at least one unit composed of a high refractive index layer and a low refractive index layer is formed on a substrate, and the high refractive index layer or the low refractive index layer is formed. Any method can be used as long as at least one of the layers can be the water-dispersible hydrophobic resin-containing layer.

Specifically, it is preferable that a high refractive index layer and a low refractive index layer are alternately coated and dried to form a laminate (dielectric multilayer film). Specific examples include the following forms: (1) A high refractive index layer coating liquid is applied on a substrate and dried to form a high refractive index layer, and then a low refractive index layer coating liquid is applied and dried. Then, a low refractive index layer is formed to form an optical reflection film; (2) A low refractive index layer coating liquid is applied on a substrate and dried to form a low refractive index layer, and then a high refractive index is formed. A method of forming a high-refractive index layer by applying a layer coating liquid and drying it, and forming an optical reflection film; (3) Alternating a high-refractive-index layer coating liquid and a low-refractive-index layer coating liquid on a substrate. To form an optical reflection film including a high refractive index layer and a low refractive index layer; (4) a high refractive index layer coating liquid and a low refractive index layer on a substrate. And the like, in which the coating liquid and the coating liquid are simultaneously multilayered to form an optical reflection film including a high refractive index layer and a low refractive index layer. Of these, the method (4) is preferable because it provides a simpler manufacturing process. That is, the method for producing an optical reflection film of the present invention preferably includes laminating the high refractive index layer and the low refractive index layer by a simultaneous multilayer coating method.

In the case of simultaneous multi-layer coating, layers are mixed in an undried liquid state, so that inter-layer mixing is more likely to occur. However, when the water-soluble resin is a polyvinyl alcohol resin, if the saponification degree of the polyvinyl alcohol resin contained in the high refractive index layer and the saponification degree of the polyvinyl alcohol resin contained in the low refractive index layer are different, saponification It is known that polyvinyl alcohol resins of different degrees have low compatibility. Therefore, even if each layer is mixed to some extent when the high refractive index layer and the low refractive index layer are stacked in an undried liquid state, when the solvent water volatilizes and is concentrated in the drying process, the saponification degree is The polyvinyl alcohol-based resins having different values cause phase separation, and a force for minimizing the area of the interface of each layer is exerted, so that interphase mixing is suppressed and interface disorder is reduced. Therefore, an optical reflection film having excellent light reflection characteristics in a desired wavelength region and less haze can be obtained.

As the coating method, for example, roll coating method, rod bar coating method, air knife coating method, spray coating method, curtain coating method, or US Pat. Nos. 2,761,419 and 2,761,791 are described. The slide bead coating method using the above hopper, the extrusion coating method and the like are preferably used.

The solvent for preparing the high refractive index layer coating liquid and the low refractive index layer coating liquid is not particularly limited, but water, an organic solvent, or a mixed solvent thereof is preferable. In the present invention, since a water-soluble resin is used, an aqueous solvent can be used. Compared with the case where an organic solvent is used, the aqueous solvent does not require a large-scale production facility, and is therefore preferable in terms of productivity and is also preferable in terms of environmental protection.

Examples of the organic solvent include alcohols such as methanol, ethanol, 2-propanol and 1-butanol, ethyl acetate, butyl acetate, esters such as 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, methylethylketone, acetylacetone and cyclohexanone. These organic solvents may be used alone or in combination of two or more. From the standpoint of environment and ease of operation, the solvent of the coating liquid is preferably an aqueous solvent, more preferably water or a mixed solvent of water and methanol, ethanol, or ethyl acetate, and particularly 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, and 90 to 99% by mass based on 100% by mass of the entire mixed solvent. It is more preferably 0.5% by mass. Here, when the content is 80% by mass or more, the volume fluctuation due to the volatilization of the solvent can be reduced and the handling is improved, and when it is 99.9% by mass or less, the homogeneity at the time of adding the liquid is increased and the stability is improved. This is because the obtained liquid physical properties can be obtained.

The concentration of the water-soluble resin in the high refractive index layer coating solution is preferably 0.5 to 10% by mass. The concentration of the metal oxide particles in the high refractive index layer coating liquid is preferably 1 to 50% by mass.

The concentration of the water-soluble resin in the low refractive index layer coating liquid is preferably 0.5 to 10% by mass. The concentration of the metal oxide particles in the low refractive index layer coating liquid is preferably 1 to 50% by mass.

The method for preparing the high-refractive-index layer coating liquid and the low-refractive-index layer coating liquid is not particularly limited, and examples thereof include a method of adding metal oxide particles, a water-soluble resin, a curing agent, etc. to an aqueous solvent and stirring and mixing. To be At this time, the order of addition of the components is not particularly limited, and the components may be sequentially added and mixed with stirring, or may be added and mixed at once with stirring.

When at least one of the high-refractive index layers is a water-dispersible hydrophobic resin-containing layer, the water-dispersible hydrophobic resin is added to the above-mentioned high-refractive index layer coating solution at a final solid concentration of a predetermined value. The water-dispersible hydrophobic resin-containing layer coating liquid (water-dispersible hydrophobic resin-containing high-refractive index layer coating liquid) may be prepared by adding it so as to be within the range. A water-dispersible hydrophobic resin-containing layer that functions as a high refractive index layer can be obtained by applying and drying the water-dispersible hydrophobic resin-containing layer coating solution.

Similarly, when at least one of the low-refractive-index layers is used as the water-dispersible hydrophobic resin-containing layer, the water-dispersible hydrophobic resin is added to the final low-refractive-index layer coating solution to obtain a final solid content concentration. To a predetermined range to prepare a water-dispersible hydrophobic resin-containing layer coating solution (water-dispersible hydrophobic resin-containing low refractive index layer coating solution). A water-dispersible hydrophobic resin-containing layer that functions as a low refractive index layer can be obtained by applying and drying the water-dispersible hydrophobic resin-containing layer coating solution.

The concentration of the water-dispersible hydrophobic resin in the water-dispersible hydrophobic resin-containing layer coating solution is not particularly limited, but the content of the water-dispersible hydrophobic resin in the water-dispersible hydrophobic resin-containing layer (solid content ) Is adjusted within the above range.

As described above, a preferred form of the optical reflection film of the present invention contains an anionic emulsion resin and an anionic surfactant in the water-dispersible hydrophobic resin-containing layer. Therefore, preferably, the optical reflection film of the present invention comprises a step of preparing a coating solution by dissolving or dispersing a water-soluble resin, an anionic surfactant, and an anionic emulsion resin in an aqueous solvent, and applying the coating solution. Thereby forming the water-dispersible hydrophobic resin-containing layer.

When the slide bead coating method is used, the temperature of the high refractive index layer coating liquid and the low refractive index layer coating liquid when performing simultaneous multilayer coating is preferably 25 to 60° C., and 30 to 45° C. Is more preferable. When using the curtain coating method, the temperature range of 25 to 60°C is preferable, and the temperature range of 30 to 45°C is more preferable.

The viscosities of the high refractive index layer coating liquid and the low refractive index layer coating liquid when performing simultaneous multilayer coating are not particularly limited. However, when the slide bead coating method is used, the temperature range of the coating solution is preferably 5 to 160 mPa·s, more preferably 60 to 140 mPa·s. When the curtain coating method is used, the temperature range of the coating liquid is preferably 5 to 1200 mPa·s, more preferably 25 to 500 mPa·s. Within such a viscosity range, simultaneous multilayer coating can be efficiently performed.

The viscosity of the coating liquid at 15° C. is preferably 100 mPa·s or more, more preferably 100 to 30,000 mPa·s, and further preferably 2,500 to 30,000 mPa·s.

The conditions of the coating and drying methods are not particularly limited. For example, in the case of the sequential coating method, first, either the high refractive index layer coating solution or the low refractive index layer coating solution heated to 30 to 60° C. is first applied. After coating and drying on a base material to form a layer, the other coating solution is applied on this layer and dried to form a laminated film precursor (unit). Next, the number of units required for expressing the desired optical reflection performance is sequentially applied by the above method, dried and laminated to obtain a laminated film precursor. When drying, the formed coating film is preferably dried at 30° C. or higher. For example, it is preferable to dry at a wet bulb temperature of 5 to 50°C and a film surface temperature of 5 to 100°C (preferably 10 to 50°C). For example, hot air of 40 to 60°C is blown for 1 to 5 seconds. dry. As the drying method, warm air drying, infrared drying, and microwave drying are used. In addition, drying in a multi-stage process is preferable to drying in a single process, and it is more preferable to set the temperature of the constant rate drying unit<the temperature of the decreasing rate drying unit. In this case, the temperature range of the constant rate drying unit is preferably 30 to 60°C, and the temperature range of the rate decreasing drying unit is preferably 50 to 100°C.

In addition, the conditions of the coating and drying methods when performing simultaneous multilayer coating are as follows: the high refractive index layer coating liquid and the low refractive index layer coating liquid are heated to 30 to 60° C. to coat the high refractive index layer on the substrate. After the simultaneous multilayer coating of the liquid and the low refractive index layer coating liquid is performed, the temperature of the formed coating film is preferably once cooled (set) to preferably 1 to 15° C., and then dried at 10° C. or higher. More preferable drying conditions are conditions of a wet bulb temperature of 5 to 50° C. and a film surface temperature of 10 to 50° C. For example, hot air of 40 to 80° C. is blown for 1 to 5 seconds to dry. The cooling method immediately after coating is preferably a horizontal setting method from the viewpoint of improving the uniformity of the formed coating film.

Here, the set means increasing the viscosity of the coating composition by lowering the temperature by applying cold air or the like to the coating to lower the fluidity of the substances in each layer or in each layer, and It means the process of converting into. The state where the finger is pressed against the surface of the coating film by applying cold air to the surface of the coating film and nothing touches the finger is defined as the setting completion state.

The time from the time of application to the completion of setting by applying cold air (set time) is preferably within 5 minutes, more preferably within 2 minutes. The lower limit time is not particularly limited, but it is preferably 45 seconds or more. The step of setting may be omitted if the elasticity of the intermediate layer between the high refractive index layer and the low refractive index layer is rapidly increased.

The setting time can be adjusted by adjusting the concentration of polyvinyl alcohol-based resin and the concentration of metal oxide particles, and adding other components such as various known gelling agents such as gelatin, pectin, agar, carrageenan and gellan gum. It can be adjusted by

The temperature of the cold air is preferably 0 to 25°C, more preferably 5 to 10°C. The time for which the coating film is exposed to cold air is preferably 10 to 360 seconds, more preferably 10 to 300 seconds, further preferably 10 to 120 seconds, depending on the transport speed of the coating film.

The high-refractive-index layer coating liquid and the low-refractive-index layer coating liquid may be applied so as to have the preferable dry thicknesses as described above.

<Optical reflector>
The optical reflection film of the present invention can be applied to a wide range of fields. Therefore, one embodiment of the present invention is an optical reflector in which the above-mentioned optical reflection film is provided on at least one surface of a substrate. For example, a window sticking film such as a heat ray reflecting film that is attached to a facility (base) that is exposed to sunlight for a long period of time such as an outdoor window of a building or an automobile window, a film for agricultural greenhouses. Etc. are mainly used for the purpose of enhancing weather resistance. In particular, it is suitable for a member in which the optical reflection film according to the present invention is bonded to a substrate such as glass or a glass-substituting resin via the above-mentioned adhesive layer.

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, phenol. Examples thereof include resins, diallyl phthalate resins, polyimide resins, urethane resins, polyvinyl acetate resins, polyvinyl alcohol resins, styrene resins, vinyl chloride resins, metal plates and ceramics. The type of resin may be any of a thermoplastic resin, a thermosetting resin, and an ionizing radiation curable resin, and two or more kinds of these may be used in combination. The substrate can be manufactured by a known method such as extrusion molding, calender 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.

The pressure-sensitive adhesive layer for bonding the optical reflection film and the substrate is preferably placed so that the optical reflection film is on the side of the sunlight (heat ray) incident surface side when it is bonded to a window glass or the like. If the optical reflection film is sandwiched between the window glass and the base material, it can be sealed from ambient gas such as moisture, which is preferable for durability. Even if the optical reflection film of the present invention is installed outdoors or on the outside of a car (for external sticking), it is preferable because it has environmental durability.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the examples, “part” or “%” is used, but unless otherwise specified, “part by mass” or “% by mass” is indicated. Unless otherwise specified, each operation is performed at room temperature (25°C).

<<Preparation of optical reflection film>>
(Example 1)
<Preparation of High Refractive Index Layer Coating Liquid 1>
The high refractive index layer coating liquid 1 was prepared according to the following procedure.

(Preparation of silica-attached titanium dioxide sol)
First, a silica-adhered titanium dioxide sol containing rutile titanium dioxide was prepared as follows.

After adding 2 parts by mass of pure water to 0.5 parts by mass of 15.0% by mass titanium oxide sol (SRD-W, volume average particle size: 5 nm, rutile type titanium dioxide particles, manufactured by Sakai Chemical Industry Co., Ltd.), 90°C. Heated to. Next, 0.5 parts by mass of an aqueous solution of silicic acid (sodium silicate No. 4 (manufactured by Nippon Kagaku Kogyo Co., Ltd.) diluted with pure water to a SiO ₂ concentration of 0.5% by mass) was gradually added. Then, heat treatment was carried out in an autoclave at 175° C. for 18 hours, and after cooling, it was concentrated by an ultrafiltration membrane to deposit SiO ₂ having a solid content concentration of 6 mass% with respect to titanium dioxide on the surface. A titanium dioxide sol (hereinafter referred to as silica-adhered titanium dioxide sol) (volume average particle diameter: 9 nm) was obtained.

(Preparation of coating liquid 1 for high refractive index layer)
48 parts by mass of an aqueous citric acid solution (1.92% by mass) was added to 113 parts by mass of the silica-adhered titanium dioxide sol (20% by mass) obtained by the above procedure, and polyvinyl alcohol (PVA-117 manufactured by Kuraray Co., Ltd.) was added. , Average degree of polymerization 1700, degree of saponification: 97.5 to 99 mol%, 8% by mass) were added by 113 parts by mass and stirred, and finally a 5% by mass aqueous solution of a surfactant (Softofazoline LSB-R, Kawaken Fine Chemicals Co., Ltd.) 0.4 parts by mass) was added to prepare a high refractive index layer coating liquid 1.

The refractive index of the film coated with the high refractive index layer coating liquid 1 was 1.80. The method for measuring the refractive index is as follows (the same applies hereinafter).

<Measurement of single film refractive index of each layer>
In order to measure the refractive index, a sample was prepared by coating the above-mentioned high refractive index layer coating liquid 1 in a single layer on a substrate, and after cutting this sample into 10 cm×10 cm, the refractive index was determined according to the following method. .. A spectrophotometer U-4100 (solid sample measurement system) manufactured by Hitachi was used to roughen the surface (back surface) opposite to the measurement surface of each sample, and then perform light absorption processing with a black spray. The reflectance of the visible light region (400 nm to 700 nm) was measured under the condition of 5° specular reflection while preventing the reflection of light on the back surface, and the refractive index was determined from the results.

<Preparation of coating liquid 1 for low refractive index layer>
31 parts by mass of a 10% by mass aqueous solution of acidic colloidal silica (Snowtex (registered trademark) OXS, primary particle size: 5.4 nm, manufactured by Nissan Chemical Industries, Ltd.) is heated to 40° C. to prepare a 3% by mass boric acid aqueous solution. 3 parts by mass was further added, and as a water-soluble resin, 39 parts by mass of a 6% by mass aqueous solution of polyvinyl alcohol (PVA-224, average degree of polymerization: 2400, degree of saponification: 87 to 89 mol%, manufactured by Kuraray Co., Ltd.) and 1 A low-refractive-index layer coating solution 1 was prepared by adding 5 parts by weight of a 5% by mass aqueous solution of a surfactant (Softofazoline LSB-R, manufactured by Kawaken Fine Chemical Co., Ltd.) in this order at 40°C.

The refractive index of the film coated with the low refractive index layer coating liquid 1 was 1.50.

<Preparation of coating liquid 1 for low refractive index layer containing water-dispersible hydrophobic resin>
13 parts by mass of a 10% by mass aqueous solution of acidic colloidal silica (Snowtex (registered trademark) OXS, primary particle size: 5.4 nm, manufactured by Nissan Chemical Industries, Ltd.) was heated to 40° C., and a 3% by mass boric acid aqueous solution was added. In addition to 3 parts by mass, as a water-soluble resin, 35 parts by mass of a 6% by mass aqueous solution of polyvinyl alcohol (PVA-224, average degree of polymerization: 2400, degree of saponification: 87 to 89 mol%, manufactured by Kuraray Co., Ltd.) and 3 parts by mass. Parts of water-dispersed urethane resin 6% by mass aqueous solution (Adekabon Titer HUX-830, average particle size=100 nm, manufactured by ADEKA Corporation) and 1 part by mass of 5% by mass aqueous solution of nonionic surfactant (Neugen XL-40. , Manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) were added in this order at 40° C. to prepare coating solution 1 for water-dispersible hydrophobic resin-containing low refractive index layer.

It was confirmed by measuring the zeta potential that the water-dispersed urethane resin was a nonionic resin. The specific measuring method is as follows.

Device: Malvern Zetasizer Nano ZSP
Measurement method: Electrophoretic light scattering method Sample preparation: Water-dispersible hydrophobic resin diluted to 1% by mass is measured.

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 was 1.50.

<Production of Optical Reflective Film 1>
Using a slide hopper coater capable of 19-layer multi-layer coating, the high refractive index layer coating liquid 1, the low refractive index layer coating liquid 1, and the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 prepared above were prepared. Each was adjusted to 40°C. On a polyethylene terephthalate film having a width of 160 mm and a thickness of 50 μm (A4300 manufactured by Toyobo: double-sided easy-adhesion layer), which is a base material heated to 40° C., the lowermost layer and the uppermost layer are low refractive index layers, and the base material side is 11 Alternately, except that the layer was a water-dispersible hydrophobic resin-containing low-refractive index layer, the dry film thickness of the low-refractive index layer and the water-dispersible hydrophobic-resin-containing low refractive index layer were each 150 nm and had a high refractive index. Simultaneous multi-layer coating of a total of 19 layers was performed so that each layer had a thickness of 130 nm. Immediately after the application, cold air of 10° C. was blown to set (thicken).

After the setting (thickening) was completed, hot air at 60° C. was blown to dry the film, and thus the optical reflection film 1 of Example 1 having a total of 19 layers was produced.

For the measurement (confirmation) of the film thickness, the sample of the optical reflection film is cut, and the cut surface is measured for the abundance of the high refractive index material (TiO ₂ ) and the low refractive index material (SiO ₂ ) with an XPS surface analyzer. Thus, it was confirmed that the film thickness of each of the above layers was secured.

(Example 2)
<Preparation of coating liquid 2 for low refractive index layer containing water-dispersible hydrophobic resin>
Water-dispersible hydrophobicity except that 10% by mass aqueous solution of acidic colloidal silica was 18 parts by mass, 6% by mass aqueous solution of polyvinyl alcohol was 6 parts by mass, and 6% by mass aqueous solution of urethane resin was 47 parts by mass. A water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 2 was prepared in the same manner as the resin-containing low refractive index layer coating liquid 1.

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 2 was 1.50.

<Production of Optical Reflective Film 2>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 was added to the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 2 prepared as described above. An optical reflection film 2 was produced in the same manner as in Example 1 except that the changes were made.

(Example 3)
<Preparation of coating liquid 3 for low refractive index layer containing water-dispersible hydrophobic resin>
In Example 1 (Preparation of Dispersible Hydrophobic Resin-Containing Low Refractive Index Layer Coating Liquid 1), 10 mass% aqueous solution of acidic colloidal silica was 19 mass parts, and 6 mass% aqueous solution of polyvinyl alcohol was 38 mass parts, A water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 3 was prepared in the same manner as in Example 1 except that the aqueous 6% by weight aqueous dispersion urethane resin solution was 18 parts by mass.

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 3 was 1.50.

<Production of Optical Reflective Film 3>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 was added to the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 3 prepared as described above. An optical reflection film 3 was produced in the same manner as in Example 1 except that the changes were made.

(Example 4)
<Preparation of coating liquid 4 for low refractive index layer containing water-dispersible hydrophobic resin>
In the above-mentioned Example 1 (preparation of coating liquid 1 for low refractive index layer containing dispersible hydrophobic resin), 19 parts by mass of 10 mass% aqueous solution of acidic colloidal silica was used, and 38 parts by mass of 6 mass% aqueous solution of polyvinyl alcohol was used. The dispersion urethane resin 6 mass% aqueous solution is 18 mass parts, 1 mass part 5 mass% nonionic surfactant 5 mass% aqueous solution (Neugen XL-40, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) is 1 mass part anionic surfactant. A water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 4 was prepared in the same manner as in Example 1 except that a 5 mass% aqueous solution of the agent (Hitenol NF-08, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was used. ..

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 4 was 1.50.

<Production of Optical Reflective Film 4>
In the above Example 1 (manufacture of the optical reflection film 1), the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 was added to the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 4 prepared as described above. An optical reflection film 4 was produced in the same manner as in Example 1 except that the changes were made.

(Example 5)
<Preparation of coating liquid 5 for low refractive index layer containing water-dispersible hydrophobic resin>
In the above-mentioned Example 1 (Preparation of Dispersible Hydrophobic Resin-Containing Low Refractive Index Layer Coating Liquid 1), 3 parts by mass of a 6% by mass aqueous solution of a urethane resin (Adekabon Titer HUX-830, average particle diameter=100 nm, ADEKA) (Manufactured by Co., Ltd.) to 3 parts by mass of a water-dispersed acrylic resin 6% by mass aqueous solution (AE-116, average particle size=80 nm, manufactured by E-TEC Co., Ltd.), and 1 part by mass of 5% by mass of nonionic surfactant. Except that the aqueous solution (Neugen XL-40, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was changed to 1 part by mass of a 5% by mass aqueous solution of anionic surfactant (Hitenol NF-08, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). A water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 5 was prepared in the same manner as in Example 1.

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 5 was 1.50.

It was confirmed by measuring the zeta potential that the water-dispersed acrylic resin was an anionic resin. The specific measuring method is the same as that of the above water-dispersed urethane resin.

<Preparation of optical reflection film 5>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 was added to the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 5 prepared as described above. An optical reflection film 5 was produced in the same manner as in Example 1 except that the changes were made.

(Example 6)
<Preparation of coating liquid 6 for low refractive index layer containing water-dispersible hydrophobic resin>
In the above-mentioned Example 1 (Preparation of coating liquid 1 for low refractive index layer containing dispersible hydrophobic resin), 3 parts by mass of 6% by mass aqueous solution of water-dispersed urethane resin was added to 3 parts by mass of 6% by mass aqueous solution of acrylic resin (AE). -120 A, average particle size = 55 nm, manufactured by E-TEC Co., Ltd., and 1 part by mass of a 5% by mass aqueous solution of a nonionic surfactant is used as 1 part by mass of an anionic surfactant 5% by mass aqueous solution (Hitenol). NF-08, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., except that the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 6 was prepared in the same manner as in Example 1.

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 6 was 1.50.

<Production of Optical Reflective Film 6>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 was added to the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 6 prepared as described above. An optical reflection film 6 was produced in the same manner as in Example 1 except that the changes were made.

(Example 7)
<Preparation of coating liquid 7 for low refractive index layer containing water-dispersible hydrophobic resin>
In Example 1 (Preparation of Dispersible Hydrophobic Resin-Containing Low Refractive Index Layer Coating Liquid 1), a 6 mass% aqueous solution of acidic colloidal silica was 18 mass parts, and a 6 mass% aqueous solution of polyvinyl alcohol was 6 mass parts, 3 parts by weight of an aqueous dispersion urethane resin 6% by weight aqueous solution (Adekabon Titer HUX-830, average particle size = 100 nm, manufactured by ADEKA Corporation) 47 parts by weight of an aqueous dispersion acrylic resin 6% by weight aqueous solution (AE-120A, average) Particle size = 55 nm, manufactured by E-TEC Co., Ltd., and 1 part by mass of a 5% by mass aqueous solution of a nonionic surfactant (Neugen XL-40, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) is used as 1 part by mass of anionic interface. Water-dispersible hydrophobic resin-containing low-refractive-index layer coating liquid in the same manner as in Example 1 except that the activator was changed to a 5% by mass aqueous solution (Hitenol NF-08, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). 7 was prepared.

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 7 was 1.50.

<Production of Optical Reflective Film 7>
In the above-mentioned Example 1 (production of optical reflection film 1), the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 was added to the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 7 prepared as described above. An optical reflection film 7 was produced in the same manner as in Example 1 except that the changes were made.

(Example 8)
<Preparation of coating liquid 8 for low refractive index layer containing water-dispersible hydrophobic resin>
In Example 1 (Preparation of Dispersible Hydrophobic Resin-Containing Low Refractive Index Layer Coating Liquid 1), 10 mass% aqueous solution of acidic colloidal silica was 19 mass parts, and 6 mass% aqueous solution of polyvinyl alcohol was 38 mass parts, 3 parts by weight of 6% by weight aqueous dispersion urethane resin aqueous solution (ADEKA BON TITER HUX-830, average particle size = 100 nm, manufactured by ADEKA CORPORATION) 18 parts by weight aqueous dispersion acrylic resin 6% by weight aqueous solution (AE-120A, average) Particle size = 55 nm, manufactured by E-TEC Co., Ltd., and 1 part by mass of a 5% by mass aqueous solution of a nonionic surfactant (Neugen XL-40, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) is used as 1 part by mass of anionic interface. Water-dispersible hydrophobic resin-containing low-refractive-index layer coating liquid in the same manner as in Example 1 except that the activator was changed to a 5% by mass aqueous solution (Hitenol NF-08, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). 8 was prepared.

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 8 was 1.50.

<Production of Optical Reflective Film 8>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 was added to the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 8 prepared as described above. An optical reflection film 8 was produced in the same manner as in Example 1 except that the changes were made.

(Example 9)
<Preparation of coating liquid 9 for low refractive index layer containing water-dispersible hydrophobic resin>
In the above-mentioned Example 1 (preparation of dispersible hydrophobic resin-containing low refractive index layer coating liquid 1), 10 mass% aqueous solution of acidic colloidal silica was 19 mass parts, and 6 mass% aqueous solution of polyvinyl alcohol was 38 mass parts, 3 parts by mass of a 6% by mass aqueous solution of a water-dispersed urethane resin (Adekabon Titer HUX-830, average particle size=100 nm, manufactured by ADEKA Corporation) was added to 18 parts by mass of a 6% by mass aqueous solution of an acrylic resin in water (AE-120A, A water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 9 was prepared in the same manner as in Example 1 except that the average particle diameter was 55 nm, manufactured by E-Tech Co., Ltd.).

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 9 was 1.50.

<Production of Optical Reflective Film 9>
In the above Example 1 (manufacture of the optical reflection film 1), the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 was added to the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 9 prepared as described above. An optical reflection film 9 was produced in the same manner as in Example 1 except that the changes were made.

(Example 10)
<Production of Optical Reflective Film 10>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the coating liquid for forming the water-dispersible hydrophobic resin-containing low refractive index layer was prepared from the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1. The dispersion liquid hydrophobic resin-containing low refractive index layer coating liquid 8 was changed, and further, instead of the base material side to the 11th layer, the 19th layer from the base material side was used as a water-dispersible hydrophobic resin-containing low refractive index layer. An optical reflection film 10 was produced in the same manner as in Example 1 except that the above was performed.

(Example 11)
<Preparation of coating liquid 10 for low refractive index layer containing water-dispersible hydrophobic resin>
In the above-mentioned Example 1 (preparation of coating liquid 1 for low refractive index layer containing dispersible hydrophobic resin), 10 mass% aqueous solution of acidic colloidal silica was used as 19 mass parts, and water-soluble resin was used as 6 mass% aqueous solution of polyvinyl alcohol (JC -40, average degree of polymerization: 4000, degree of saponification: 99 mol%, manufactured by Nippon Vineline Poval Co., Ltd.), changed to 38 parts by mass, and 3 parts by mass of a 6% by mass aqueous dispersion urethane resin solution (Adekabon Titer HUX- 830, average particle size=100 nm, manufactured by ADEKA CORPORATION) was changed to 18 parts by mass of a 6% by mass aqueous solution of a water-dispersible acrylic resin (AE-120A, average particle size=55 nm, manufactured by ETEC Co., Ltd.), and 1 part by mass was used. 1 part by mass of a 5 mass% aqueous solution of a nonionic surfactant (Neugen XL-40, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (5% by mass of an anionic surfactant (HITENOL NF-08, Daiichi Kogyo Seiyaku Co., Ltd.) A water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 10 was prepared in the same manner as in Example 1 except that the coating liquid 10 was used.

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 10 was 1.50.

<Production of Optical Reflective Film 11>
In Example 1 (Preparation of Optical Reflective Film 1), the coating liquid for forming the water-dispersible hydrophobic resin-containing low refractive index layer was prepared from the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 described above. The water-dispersible hydrophobic resin-containing low-refractive-index layer coating liquid 10 prepared in the above was changed, and the 19th layer from the substrate side was replaced with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 10 instead of the substrate side. An optical reflection film 11 was produced in the same manner as in Example 1 except that the refractive index layer was used.

(Example 12)
<Preparation of coating liquid 11 for low refractive index layer containing water-dispersible hydrophobic resin>
In the above-mentioned Example 1 (preparation of coating liquid 1 for low refractive index layer containing dispersible hydrophobic resin), 10 mass% aqueous solution of acidic colloidal silica was used as 19 mass parts, and water-soluble resin was used as 6 mass% aqueous solution of polyvinyl alcohol (JP -45, average degree of polymerization: 4500, degree of saponification: 99 mol%, made by Nippon Vineline Poval Co., Ltd.) changed to 38 parts by weight, and 3 parts by weight of 6% by weight aqueous dispersion urethane resin solution (Adekabon Titer HUX- 830, average particle size=100 nm, manufactured by ADEKA CORPORATION) was changed to 18 parts by mass of a 6% by mass aqueous solution of a water-dispersible acrylic resin (AE-120A, average particle size=55 nm, manufactured by ETEC Co., Ltd.), and 1 part by mass was used. 1 part by mass of a 5 mass% aqueous solution of a nonionic surfactant (Neugen XL-40, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (5% by mass of an anionic surfactant (HITENOL NF-08, Daiichi Kogyo Seiyaku Co., Ltd.) A water-dispersible hydrophobic resin-containing low-refractive index layer coating liquid 11 was prepared in the same manner as in Example 1 except that it was manufactured by Co., Ltd.).

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 11 was 1.50.

<Production of Optical Reflective Film 12>
In Example 1 (Preparation of Optical Reflective Film 1), the coating liquid for forming the water-dispersible hydrophobic resin-containing low refractive index layer was prepared from the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 described above. Except that the water-dispersible hydrophobic resin-containing low-refractive index layer coating liquid 11 prepared in (4) was used, and the water-dispersible hydrophobic resin-containing low-refractive index layer was used as the 19th layer from the base material side. An optical reflection film 12 was produced in the same manner as in Example 1.

(Example 13)
<Production of Optical Reflective Film 13>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the coating liquid for forming the water-dispersible hydrophobic resin-containing low refractive index layer was prepared from the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1. Except that the dispersible hydrophobic resin-containing low refractive index layer coating liquid 10 was changed, and the first and 19th layers from the substrate side were water-dispersible hydrophobic resin-containing low refractive index layers, An optical reflection film 13 was produced in the same manner as in Example 1.

(Example 14)
<Production of Optical Reflective Film 14>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the coating liquid for forming the water-dispersible hydrophobic resin-containing low refractive index layer was prepared from the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1. Except that the dispersible hydrophobic resin-containing low refractive index layer coating liquid 11 was changed, and the first layer and the 19th layer from the base material side were water-dispersible hydrophobic resin-containing low refractive index layers, An optical reflection film 14 was produced in the same manner as in Example 1.

(Example 15)
<Production of Optical Reflective Film 15>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the coating liquid for forming the water-dispersible hydrophobic resin-containing low refractive index layer was prepared from the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1. Same as Example 1 except that the coating liquid 11 for the low refractive index layer containing the dispersible hydrophobic resin was used, and all the low refractive index layers were low refractive index layers containing the water dispersible hydrophobic resin. Then, the optical reflection film 15 was produced.

(Comparative Example 1)
<Preparation of coating liquid 12 for low refractive index layer containing water-dispersible hydrophobic resin>
In Example 1 (Preparation of Dispersible Hydrophobic Resin-Containing Low Refractive Index Layer Coating Liquid 1), 10 mass% aqueous solution of acidic colloidal silica was 31 mass parts, and 6 mass% aqueous solution of polyvinyl alcohol was 38 mass parts, Water-dispersible hydrophobic resin-containing low refractive index layer coating liquid in the same manner as water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 except that 6% by mass of water-dispersible urethane resin aqueous solution was used. 12 was prepared.

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 12 was 1.50.

<Production of Optical Reflective Film 16>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the coating liquid for forming the water-dispersible hydrophobic resin-containing low refractive index layer was prepared from the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1. An optical reflection film 16 was produced in the same manner as in Example 1 except that the coating liquid 12 for the low refractive index layer containing the dispersible hydrophobic resin was used.

(Comparative example 2)
<Preparation of coating liquid 13 for low refractive index layer containing water-dispersible hydrophobic resin>
In the above-mentioned Example 1 (Preparation of Dispersion Hydrophobic Resin-Containing Low Refractive Index Layer Coating Solution 1), the water-soluble resin was a 6 mass% aqueous solution of polyvinyl alcohol (trade name: PVA-210, average degree of polymerization: 1000, degree of saponification). : 88 mol %, manufactured by Kuraray Co., Ltd.) 38 parts by mass, except that the 10% by mass aqueous solution of acidic colloidal silica is 31 parts by mass and the 6% by mass aqueous dispersion urethane resin solution is 1 part by mass. A water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 13 was prepared in the same manner as the dispersible hydrophobic resin-containing low refractive index layer coating liquid 1.

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 13 was 1.50.

<Production of Optical Reflective Film 17>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the coating liquid for forming the water-dispersible hydrophobic resin-containing low refractive index layer was prepared from the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1. A low-refractive index layer-containing coating liquid 13 containing a dispersible hydrophobic resin was used. Further, instead of the 11th layer from the substrate side, the 19th layer from the substrate side was replaced with a water-dispersible hydrophobic resin-containing low refractive index layer. An optical reflection film 17 was produced in the same manner as in Example 1 except that the above was performed.

(Comparative example 3)
<Preparation of coating liquid 14 for low refractive index layer containing water-dispersible hydrophobic resin>
In Example 1 (Preparation of Dispersible Hydrophobic Resin-Containing Low Refractive Index Layer Coating Solution 1), 10 mass% aqueous solution of acidic colloidal silica was 10 mass parts, and 6 mass% aqueous solution of polyvinyl alcohol was 4 mass parts, Water-dispersible hydrophobic resin-containing low refractive index layer coating liquid in the same manner as the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1 except that the water-dispersible urethane resin 6 mass% aqueous solution was changed to 65 parts by mass. 14 was prepared.

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 14 was 1.50.

<Production of Optical Reflective Film 18>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the coating liquid for forming the water-dispersible hydrophobic resin-containing low refractive index layer was prepared from the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1. An optical reflection film 18 was produced in the same manner as in Example 1 except that the coating liquid 14 for a low refractive index layer containing a dispersible hydrophobic resin was used.

(Comparative Example 4)
<Preparation of coating liquid 15 for low refractive index layer containing water-dispersible hydrophobic resin>
In the above-mentioned Example 1 (preparation of coating liquid 1 for low refractive index layer containing dispersible hydrophobic resin), 9 mass parts of 10 mass% aqueous solution of acidic colloidal silica was used, and 6 mass% aqueous solution of polyvinyl alcohol was used as water-soluble resin. (Name: JM-23, average degree of polymerization: 2300, degree of saponification: 97 mol %, made by Japan Vine & Poval Co., Ltd.) 4 parts by mass, 6 parts by mass of water-dispersed urethane resin aqueous solution 65 parts by mass of water-dispersed acrylic Water-dispersible hydrophobicity in the same manner as in Example 1 except that the resin was changed to a 6% by mass aqueous solution (AE-120A, average particle size = 55 nm, manufactured by Etec Co., Ltd.) and no nonionic surfactant was used. A resin-containing low refractive index layer coating liquid 15 was prepared.

The refractive index of the film coated with the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 15 was 1.50.

<Production of Optical Reflective Film 19>
In the above-mentioned Example 1 (manufacture of the optical reflection film 1), the coating liquid for forming the water-dispersible hydrophobic resin-containing low refractive index layer was prepared from the water-dispersible hydrophobic resin-containing low refractive index layer coating liquid 1. An optical reflection film 19 was produced in the same manner as in Example 1 except that the coating liquid 15 for low refractive index layer containing a dispersible hydrophobic resin was used.

<<Evaluation>>
(Measurement of haze)
For the optical reflection film samples produced in the above Examples and Comparative Examples, haze (%) was measured using a haze meter (NDH2000 type manufactured by Nippon Denshoku Industries Co., Ltd.), and an average value of 10 optical reflection film samples was calculated. did. The haze value of the optical reflection film may be 2.5% or less, preferably 1.5% or less.

(Observation of coating film failure)
The optical reflection film samples produced in the above Examples and Comparative Examples were visually observed, and the total number of coating film failures (repelling, aggregates) having a diameter of 2 mm or more (pieces/1000 m ² ) was counted, and the optical reflection film sample 10 was obtained. The average value of the sheets was calculated and evaluated according to the following evaluation criteria.

◯: 10 pieces/1000 m ² or less,
○ △: 10 pieces / 1000m ² more than, 100 / 1000m ² below,
△: 100 pieces / 1000m ² more than, 500 / 1000m ² below,
X: 500/1000 m ^{2 or} more.

It should be noted that ◯, ◯Δ, and Δ can be used practically without any problem.

(Weather resistance test)
The optical reflection films produced in the above Examples and Comparative Examples were attached to blue glass having a thickness of 3 mm via an adhesive layer.

Specifically, the following adhesive layer forming coating liquid was applied to the silicone release surface of the separator NS23MA manufactured by Nakamoto Pax with a comma coater so that the dry film thickness was 10 μm, and dried at 90° C. for 1 minute. To form an adhesive layer. The film having the dielectric multilayer film formed thereon was bonded to the adhesive layer to form an adhesive layer on the dielectric multilayer film.

Preparation of Adhesive Layer-Forming Coating Liquid Corponate L-55E (manufactured by Nippon Polyurethane Industry Co., Ltd.), which is a curing agent, is used against COPONYL (registered trademark) N-6941M (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), which is an adhesive agent. Add 3% by mass, further add 5% by mass of TINUVIN 477 (manufactured by BASF Japan Ltd.), which is an ultraviolet absorber, and dilute it with ethyl acetate as a solvent so that the solid content becomes 10% by mass. A forming coating solution was prepared.

Using a xenon weather meter (manufactured by Suga Test Instruments Co., Ltd., which emits light extremely similar to sunlight) at 50° C. and 70% RH, this sample was sprayed with xenon light having an intensity of 180 W/m ² for 18 minutes with water. 22 minutes of drying were repeatedly exposed. After that, it was visually confirmed whether or not a film crack occurred on the film after every 10 hours, and the film was evaluated according to the following evaluation criteria.

A: No film cracking occurred,
B: A slight film crack has occurred,
C: A film crack that is sufficiently visible is generated,
D: Film cracking is apparently generated on the entire film.

The point where the above evaluation was C or higher was defined as the crack generation time. The evaluation results are shown in Table 1 below.

From the results in Table 1 above, it was found that a water-dispersible hydrophobic resin-containing layer having a water-soluble resin and a water-dispersible hydrophobic resin was provided, and water was added to the solid content mass of the water-dispersible hydrophobic resin-containing layer. It can be seen that the optical reflection films of Examples 1 to 15 containing the dispersible hydrophobic resin in an amount of 5 to 55 mass% have excellent weather resistance as compared with the optical reflection films of Comparative Examples 1 to 4. It was also found that coating film failure was reduced.

Furthermore, in Examples 5 to 8 in which an anionic emulsion resin is used as the water-dispersible hydrophobic resin and an anionic surfactant is used, the coating film failure is further improved as compared with Examples 1 to 4 and 9.

Further, in Examples 11 to 15 using the anionic emulsion resin in the uppermost layer and the water-soluble resin having an average degree of polymerization of 4000 to 6000, the weather resistance was further improved and the haze was also improved. In particular, Examples 13 and 14 in which the lowermost layer is also a water-dispersible hydrophobic resin-containing layer containing an anionic emulsion resin, and all low refractive index layers including the uppermost layer and the lowermost layer are water-dispersible containing anionic emulsion resin. It was found that in Example 15 in which the hydrophobic resin-containing layer was used, the effect of improving the weather resistance was high.

This application is based on Japanese Patent Application No. 2015-111712 filed on June 1, 2015, the disclosure content of which is incorporated by reference in its entirety.

Claims (6)

Base material,
Arranged on one surface of the base material, a dielectric multilayer film in which a low refractive index layer and a high refractive index layer are alternately stacked,
At least one layer of the low-refractive index layer and the high-refractive index layer contains a water-soluble resin and a water-dispersible hydrophobic resin of 5 to 55% by mass based on the total mass of the water-dispersible hydrophobic resin. containing layer der is,
The optical reflection film , wherein the water-dispersible hydrophobic resin-containing layer further contains an anionic surfactant, and the water-dispersible hydrophobic resin is an anionic emulsion resin . The optical reflection film according to claim 1, wherein in the dielectric multilayer film, the uppermost layer on the side opposite to the side in contact with the substrate is the water-dispersible hydrophobic resin-containing layer. The optical reflection film according to claim 1 or 2 , wherein in the dielectric multilayer film, the lowermost layer in contact with the substrate is the water-dispersible hydrophobic resin-containing layer. The top and bottom layers of the dielectric multilayer film is a low refractive index layer, all the low refractive index layer is the water-dispersible hydrophobic resin containing layer, according to any one of claims 1 to 3 Optical reflection film. The average degree of polymerization of the water-soluble resin of the water-dispersible hydrophobic resin containing layer is 4000 to 6000, an optical reflection film according to any one of claims 1-4. A step of preparing a coating solution by dissolving or dispersing a water-soluble resin, an anionic surfactant, and an anionic emulsion resin in an aqueous solvent,
Forming the water-dispersible hydrophobic resin-containing layer by applying the coating liquid, the method for producing an optical reflection film according to claim 1 .