WO2016133022A1 - Heat shielding film - Google Patents

Abstract

　The present invention provides a means for suppressing/preventing an increase in hazing over time in high temperature, high humidity environments. This heat shielding film has a heat shielding layer on a substrate, said heat shielding layer comprising: at least one among tungsten oxide and composite tungsten oxide; a polymer of a monomer component having an acid value of at most 20 and including a (meth)acrylate monomer; and a basic, nitrogen-containing compound.

Description

Thermal barrier film

The present invention relates to a thermal barrier film. More specifically, the present invention relates to a technique for improving weather resistance in a thermal barrier film having a thermal barrier layer containing tungsten oxide.

As part of energy-saving measures, from the viewpoint of reducing the load on cooling equipment, there is an increasing demand for a thermal barrier film that is attached to the window glass of buildings and vehicles and shields the transmission of solar heat rays (infrared rays). .

As such a heat-shielding film, for example, Patent Document 1 discloses a light absorption layer containing tungsten oxide and / or composite tungsten oxide particles having an infrared cut function and an oxime compound between a pair of transparent substrates. A laminated body for heat shielding has been proposed. It is described that the heat shielding laminate can suppress a decrease in visible light transmittance over time.

JP 2013-087762 A

However, the laminated body for heat shielding described in Patent Document 1 has a problem in weather resistance because the haze tends to increase in a high temperature and high humidity environment.

Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a means capable of suppressing and preventing an increase in haze over time in a high-temperature and high-humidity environment.

As a result of intensive studies to solve the above problems, the present inventor has polymerized a (meth) acrylate monomer having a specific acid value in a thermal barrier layer containing tungsten oxide and / or composite tungsten oxide. It was learned that the above problems could be solved by using a product and a basic nitrogen-containing compound, and the present invention was completed.

That is, the object is a thermal barrier film having a thermal barrier layer on a substrate, wherein the thermal barrier layer has an acid value containing at least one of tungsten oxide and composite tungsten oxide, and a (meth) acrylate monomer. This is achieved by a thermal barrier film containing a polymer of 20 or less monomer components and a basic nitrogen-containing compound.

The heat shield film of the present invention has a heat shield layer on the substrate. In the present invention, the thermal barrier layer comprises at least one of tungsten oxide and composite tungsten oxide, a polymer of a monomer component having an acid value of 20 or less containing a (meth) acrylate monomer, and a basic nitrogen-containing compound. contains. According to the above configuration, in the thermal insulation film having the thermal insulation layer containing tungsten oxide and / or composite tungsten oxide, it is possible to suppress / prevent increase in haze over time even in a high temperature and high humidity environment.

In this specification, “at least one of tungsten oxide and composite tungsten oxide” is also collectively referred to as “tungsten oxide or the like”. In the present specification, a polymer of a monomer component containing an (meth) acrylate monomer and having an acid value of 20 or less is also simply referred to as “polymer according to the present invention”.

The heat shielding laminate described in Patent Document 1 has a light absorption layer containing tungsten oxide or the like and an oxime compound that is a basic nitrogen-containing compound. Tungsten oxide or the like has a high energy absorption capability in the near infrared region. For this reason, although the heat shielding laminated body of patent document 1 is excellent in heat-shielding property, on the other hand, in an environment with much moisture, the haze is likely to increase with time, and there is a problem in terms of weather resistance. In Patent Document 1, it is described that the light absorption layer may contain a resin binder, but no investigation has been made on the resin binder.

On the other hand, in the present invention, the thermal barrier layer containing tungsten oxide or the like is a polymer of a monomer component having an acid value of 20 or less containing a (meth) acrylate monomer in addition to the basic nitrogen-containing compound. It is characterized by including. By taking this configuration, it is possible to suppress / prevent the increase in haze of the thermal barrier film over time even in a high temperature and high humidity environment. Although the detailed mechanism by which the heat-shielding film of the present invention exhibits the above effects is unknown, it is presumed as follows. In addition, this invention is not restrained by the following mechanism at all.

That is, as a result of earnestly examining the cause of the increase in the haze of the heat shield film over time, the hydrogen ions generated during the formation of the heat shield layer cause hydrolysis of the (meth) acrylate resin (polymer according to the present invention). I guessed to catalyze it. In particular, when tungsten oxide or the like coexists, tungsten oxide or the like induces a redox reaction under acidic conditions, and further promotes hydrolysis of the polymer. As a result, the haze of the thermal barrier film increases with time in a high temperature and high humidity environment. Therefore, by using a monomer component containing a (meth) acrylate monomer having a low acid value, that is, having a low carboxyl group or salt content, hydrogen ions generated in the heat shielding layer under high humidity The amount can be reduced, thereby suppressing hydrolysis of the polymer. Therefore, by taking the above configuration, it is possible to suppress / prevent the haze increase (particularly the initial increase) of the heat-shielding film even in a high temperature and high humidity environment.

In addition to the above, the heat shielding layer according to the present invention contains a basic nitrogen-containing compound. As described above, by using a polymer of a (meth) acrylate monomer having a low acid value for the heat shielding layer, hydrolysis of the polymer under high humidity can be suppressed. However, the carboxylic acid or carboxylate (COOR; R is an alkali metal or alkyl group) present in the polymer (a structural unit derived from a (meth) acrylate monomer) is hydrolyzed by the presence of moisture to generate hydrogen ions. And the polymer is hydrolyzed by the same mechanism as described above. However, since the basic nitrogen-containing compound traps (neutralizes) the generated hydrogen ions, the amount of hydrogen ions present in the heat shield layer is suppressed over time, and the concentration of hydrogen ions in the heat shield layer Is kept low, thereby inhibiting hydrolysis of the polymer. For this reason, by taking the said structure, the raise (especially raise with time) of the heat-shielding film can be suppressed / prevented even in a high temperature and high humidity environment.

Therefore, in the heat-shielding film of the present invention, hydrolysis of the polymer in the heat-shielding layer can be suppressed / prevented even in a high-temperature and high-humidity environment. , Weather resistance can be improved.

Hereinafter, embodiments of the present invention will be described. In addition, this invention is not limited only to the following embodiment.

In this specification, “(meth) acrylate” and “(meth) acryl” are generic names for acrylate and methacrylate. Similarly, a compound containing (meth) such as (meth) acryl is a generic term for a compound having “meth” in the name and a compound not having “meta”. That is, “(meth) acryl” means “acryl and / or methacryl”.

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

[Base material]
The base material has a function of supporting a heat shielding layer and other optional layers (for example, a functional layer typified by a dielectric multilayer film).

The substrate is preferably transparent, and various resin films can be used. For example, polyolefin film (polyethylene, polypropylene, etc.), polyester film (polyethylene terephthalate, polyethylene naphthalate, etc.), polyvinyl chloride, cellulose triacetate, polyimide, polybutyral film, cycloolefin polymer film, transparent cellulose nanofiber film, etc. Can be used. Among these, it is preferable to use a polyester film.

Among the polyester films, from the viewpoint of transparency, mechanical strength and dimensional stability, dicarboxylic acid components such as terephthalic acid and 2,6-naphthalenedicarboxylic acid, and diols such as ethylene glycol and 1,4-cyclohexanedimethanol It is preferable that it is polyester which has the film formation property which makes a component a main structural component. Of these, polyesters mainly composed of polyethylene terephthalate and polyethylene naphthalate, copolymerized polyesters composed of terephthalic acid, 2,6-naphthalenedicarboxylic acid and ethylene glycol, and mixtures of two or more of these polyesters are mainly used. Polyester as a constituent component is preferable.

Further, as the base material of the present application, in addition to those mentioned above, a dielectric multilayer film to be described later and having a self-supporting property can be used. Although it does not restrict | limit especially as a dielectric multilayer film which has a self-supporting property, For example, the dielectric multilayer film etc. which were produced by the co-extrusion method or the co-flow method, etc. are mentioned, for example.

The material and film thickness of the base material are preferably set so that the value obtained by dividing the thermal shrinkage rate of the thermal barrier film by the thermal shrinkage rate of the base material is in the range of 1 to 3.

In particular, the thickness of the substrate is preferably 30 to 200 μm, more preferably 30 to 150 μm, and most preferably 35 to 125 μm. It is preferable that the thickness of the substrate is 30 μm or more because wrinkles during handling are less likely to occur. On the other hand, when the thickness of the substrate is 200 μm or less, for example, when the thermal barrier film is bonded to the substrate, the followability to the curved substrate is improved, and wrinkles are less likely to occur.

The substrate is preferably a biaxially oriented polyester film, but an unstretched or at least one stretched polyester film can also be used. A stretched film is preferable from the viewpoint of improving strength and suppressing thermal expansion. In particular, when it is used as a laminated glass for an automobile windshield, a stretched film is more preferable.

[Heat shield layer]
In the present invention, the heat shielding layer comprises (a) a tungsten oxide or the like, (b) a polymer of monomer components having a (meth) acrylate monomer and having an acid value of 20 or less, and (c) a basic nitrogen-containing compound. Is mandatory. Specifically, it is formed by applying a heat shielding layer coating solution containing the above (a), (b) and (c) on a substrate, and then irradiating with ultraviolet rays to cure the coating film.

The thickness of the heat shield layer is not particularly limited, but is preferably 1 to 10 μm, more preferably 1.5 to 8 μm. By setting the thickness to 1 μm or more, the heat shielding layer can exhibit sufficient heat shielding properties. On the other hand, by setting the thickness to 10 μm or less, it is possible to prevent cracking of the heat shield layer due to stress.

Here, (a) tungsten oxide is a kind of heat ray shielding metal oxide having infrared absorptivity (also referred to as “infrared shielding metal oxide”). The heat shield layer formed from the coating solution has a heat shield function that shields transmission of heat rays (infrared rays).

The heat shield layer may contain tungsten oxide or composite tungsten oxide, or may contain a combination of tungsten oxide and composite tungsten oxide. Each of the tungsten oxide and the composite tungsten oxide may be used alone or in the form of a mixture of two or more.

The tungsten oxide is represented by the general formula: W _y O _z , and the same tungsten oxide as described in JP 2013-64042 A or JP 2010-215451 A can be used. In the above general formula, W represents tungsten. O represents oxygen. y and z are compositions of tungsten and oxygen (composition of oxygen with respect to tungsten, z / y), and those satisfying the relationship of less than 3 (z / y <3) are generally used. Further, the composition of tungsten and oxygen preferably satisfies the relationship of more than 2 and less than 3 (2 <z / y <3), and 2.2 to 2.999 (2.2 ≦ z / y ≦ 2.999). It is more preferable to satisfy the relationship of With such a z / y ratio, the material is chemically stable and can exhibit high infrared absorbing ability, and a necessary amount of free electrons can be generated to provide an efficient infrared absorbing material.

The composition of the composite tungsten oxide is not particularly limited, but is preferably an oxide represented by the general formula: M _x W _y O _z in general from the viewpoint of stability. Also, the same ones as described in JP 2010-215451 A can be used. In the above general formula, M is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag , Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re , Be, Hf, Os, Bi, I represents one or more elements selected from I. W represents tungsten. O represents oxygen. x, y, and z are generally compositions of tungsten and M (composition of M with respect to tungsten, x / y) satisfying 0 <x / y ≦ 1, and a composition of tungsten and oxygen (of oxygen with respect to tungsten). A composition whose z / y) satisfies 2 <z / y ≦ 3 is used. Further, the composition of tungsten and M (composition of M with respect to tungsten, x / y) satisfies the relationship of 0.001 ≦ x / y ≦ 1, and the composition of tungsten and oxygen (composition of oxygen with respect to tungsten, z / y) ) Preferably satisfies the relationship of 2.2 ≦ z / y ≦ 3, more preferably satisfies the relationship of 0.2 ≦ x / y ≦ 0.5 and 2.45 ≦ z / y ≦ 3, and 0 More preferably, the relationship of .31 ≦ x / y ≦ 0.35 and 0.27 ≦ z / y ≦ 3 is satisfied. Here, the alkali metal is a periodic table group 1 element excluding hydrogen, and is lithium, sodium, potassium, rubidium, cesium, or frangium. Alkaline earth metals are Group 2 elements of the periodic table and are calcium, strontium, barium, and radium. The rare earth elements are Sc, Y and lanthanoid elements (elements from 57th lanthanum to 71st lutetium). In particular, from the viewpoint of the optical characteristics and the weather resistance improvement effect as an infrared absorbing material, the M element is one or more of Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn. Some are preferable, and a cesium-containing composite tungsten oxide represented by Cs _x W _y O _{z in} which the M element is Cs is particularly preferable.

The tungsten oxide that can be used in one embodiment of the present invention is not particularly limited, and examples thereof include Cs _0.33 WO ₃ and Rb _0.33 WO ₃ . It is particularly preferable to use Cs _0.33 WO ₃ which is a cesium-containing composite tungsten oxide. That is, in the present invention, the composite tungsten oxide is preferably cesium-doped tungsten oxide (the thermal barrier layer includes cesium-doped tungsten oxide as the composite tungsten oxide).

The shape of the tungsten oxide or the like is not particularly limited, and may take any structure such as a particle shape, a spherical shape, a rod shape, a needle shape, a plate shape, a column shape, an indeterminate shape, a flake shape, and a spindle shape, but preferably a particulate shape. It is. Further, the size of tungsten oxide or the like is not particularly limited, but when tungsten oxide or the like is in the form of particles, the average particle size (average primary particle diameter, diameter) of the particles such as tungsten oxide is the reflection of visible light. It is preferably 5 to 200 nm, more preferably 10 to 100 nm, since the heat ray absorption effect can be secured while suppressing haze, and haze deterioration due to scattering does not occur and transparency can be secured. The average particle size is determined by observing particles themselves or particles appearing on the cross section or surface of the refractive index layer with an electron microscope, measuring the particle size of 1,000 arbitrary particles, and calculating the simple average value (number average). As required. Here, the particle diameter of each particle is represented by a diameter assuming a circle equal to the projected area.

The content of tungsten oxide or the like in the heat shielding layer is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, based on the total solid content of the heat shielding layer. If it is such quantity, since tungsten oxide etc. can absorb a heat ray enough, the thermal insulation performance of an optical control film can be improved more.

Alternatively, the content of tungsten oxide or the like (in terms of solid content) in the heat shield layer is not particularly limited, but is preferably 10 with respect to the heat shield layer from the viewpoints of the heat shielding effect and the visible light transmittance. -50 mass%, more preferably 15-40 mass%.

In addition, specific trade names of these include CWO-dispersed tungsten oxide based CWO dispersion (YMF-02A, manufactured by Sumitomo Metal Mining Co., Ltd.).

In addition to the above (a), the heat shielding layer essentially includes a polymer of a monomer component having an acid value of 20 or less including (b) a (meth) acrylate monomer. Here, if the acid value of the monomer component exceeds 20, the concentration of hydrogen ions generated in the heat-shielding layer under high humidity becomes too high, excessively inducing hydrolysis of the polymer, and shielding. The haze of the thermal film increases with time and with time. Considering the further inhibitory effect of hydrolysis of the polymer, and hence the further inhibitory effect of the increase in haze of the thermal barrier film, the acid value of the monomer component is preferably 15 or less, more preferably 10 or less. In addition, since it is so preferable that the acid value of a monomer component is low, the minimum of the acid value of a monomer component is 0, but 1 is enough. In the present specification, the (meth) acrylate monomer is a polymerizable compound that is cured by ultraviolet rays. The term (meth) acrylate monomer is a concept that can include not only monomers but also oligomers and prepolymers that can be cured by ultraviolet irradiation.

In this specification, the acid value of the monomer component when using two or more monomers means the acid value of the monomer mixture. Moreover, in this specification, the acid value of a monomer component is the value measured by the following method.

<Method for measuring acid value of monomer component>
The acid value of the monomer component is measured according to JIS K 0070 (1992).

Specifically, (meth) acrylate monomer Sg (5 g) is precisely weighed in a flask and used as a sample. When measuring the acid value of a mixture of two or more (meth) acrylate monomers or a mixture of a (meth) acrylate monomer and another monomer, the desired (meth) acrylate monomer or (meth) acrylate Monomers and other monomers are mixed at a predetermined mass ratio, and the resulting mixture is precisely weighed into a flask with Sg (5 g) (total mass) as a sample. To the sample thus prepared, a mixed solvent of 50 mL of 2-propanol and 50 mL of diethyl ether is added and completely dissolved on a water bath. Next, titration is performed with a 0.1 mol / L potassium hydroxide ethanol solution using a potentiometric titrator, and the inflection point of the obtained titration curve is set as the end point. The acid value is calculated by the following formula (1).

In the above formula (1), B is the amount (ml) of 0.1 mol / l potassium hydroxide ethanol solution used for titration; f is the factor of 0.1 mol / L potassium hydroxide ethanol solution; S is the mass (g) of the sample; 5.611 represents 1/10 of the 1 mol amount of potassium hydroxide 56.11.

Here, the (meth) acrylate monomer having an acid value of 20 or less is not particularly limited, but isocyanuric acid EO-modified di (meth) acrylate, polypropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, diglycerin. EO-modified (meth) acrylate, 1,6-hexanediol di (meth) acrylate, PO-modified neopentylglycol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, trimethylolprohuntri (meth) acrylate, Trimethylolpropane PO modified tri (meth) acrylate, trimethylolpropane EO modified tri (meth) acrylate, isocyanuric acid EO modified tri (meth) acrylate, pentaerythritol tri (me ) Acrylate, glycerol propoxy tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate. Of these, considering the further effect of suppressing hydrolysis of the polymer, and hence the effect of further suppressing the increase in haze of the thermal barrier film, trimethylolprohuntri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipenta Erythritol hexa (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate are preferable, and trimethylolprohantriacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate are more preferable.

In addition, since the acid value of a monomer component should just be 20 or less as mentioned above, a monomer component is other than the (meth) acrylate monomer whose said acid value exceeds 20, or a (meth) acrylate monomer. Other monomers may be included. Here, the (meth) acrylate monomer having an acid value exceeding 20 is not particularly limited as long as it can be cured by ultraviolet irradiation, but ω-carboxy-polycaprolactone mono (meth) acrylate, monohydroxy phthalate Examples include ethyl (meth) acrylate, β-carboxyethyl (meth) acrylate, and 2- (meth) acryloyloxyethyl succinate. Alternatively, for example, commercially available products such as Aronix M-5300 and M-5400 manufactured by Toagosei Co., Ltd. are also used as appropriate.

Here, the monomer or monomer component may be synthesized or a commercially available product may be used. Here, commercially available products include Aronix M-215, M-220, M-225, M-270, M-240, M-309, M-310, M-321, M-350, M-360, M -313, M-315, M-306, M-305, M-303, M-452, M-450, M-408, M-403, M-400, M-402, M-404, M-406 , M-405, M-460 (above, manufactured by Toagosei Co., Ltd.), EBECRYL 145, IRR 214-K, OTA 480, EBECRYL 40, EBECRYL 180, EBECRYL 350 (above, manufactured by Daicel Ornex Co., Ltd.), KAYARAD NPGDA, PEG400DA, FM-400, R-167, HX-220, HX-620, R-604, R-684, GPO-3 3, THE-330, TPA-330, PET-30, DPEA-12, D-310, DPCA-20, DPCA-30, DPCA-60, DPCA-120, FM-700 (above, manufactured by Nippon Kayaku Co., Ltd.) ) Etc. can be used.

Particularly preferably, the monomer component is composed only of a (meth) acrylate monomer having an acid value of 20 or less.

Further, the (meth) acrylate monomer is preferably a polymerizable acrylate having a primary hydroxyl group. Since the acrylate having a hydroxyl group shortens the distance between reactive groups due to hydrogen bonding, the crosslinking density can be increased. Therefore, even if the polymer ((meth) acrylate monomer cured product) undergoes some hydrolysis over time, low molecular components are hardly generated, and haze increase can be more effectively suppressed. Here, the number of primary hydroxyl groups in the molecule of the (meth) acrylate monomer having a primary hydroxyl group is preferably 1 to 4. It is more preferable that it is 4 or less from the viewpoint of adhesion. From the same viewpoint, 1 to 2 is more preferable, and 1 is more preferable.

In the case where the (meth) acrylate monomer is a polymerizable acrylate having a primary hydroxyl group, the hydroxyl value of the polymerizable acrylate is not particularly limited, but is preferably 20 or more in consideration of further suppression of an increase in haze. More preferably, it is 40 or more. That is, in the present invention, the hydroxyl value of the polymerizable acrylate is particularly preferably 40 or more. The upper limit of the hydroxyl value of the (meth) acrylate monomer is not particularly limited, but usually 200 or less is sufficient. When the hydroxyl value is 200 or less, the effect of suppressing curling caused by moisture absorption is greater.

Examples of the (meth) acrylate monomer having such a hydroxyl value include dipentaerythritol penta (meth) acrylate and pentaerythritol tri (meth) acrylate. Alternatively, commercially available products such as Aronix (registered trademark) M-305, M-402, M-404, M-405 manufactured by Toagosei Co., Ltd. may be used as appropriate.

In the present specification, the hydroxyl value of the (meth) acrylate monomer when two or more kinds of (meth) acrylate monomers are used means the hydroxyl value of the (meth) acrylate monomer mixture. Moreover, in this specification, the hydroxyl value of a (meth) acrylate monomer is a value measured by the following method.

<< Measurement of hydroxyl value of (meth) acrylate monomer >>
The hydroxyl value of the (meth) acrylate monomer is measured according to JIS K 0070 (1992).

Specifically, (meth) acrylate monomer Xg (1 g) is precisely weighed in a flask and used as a sample. When measuring the hydroxyl value of a mixture of two or more (meth) acrylate monomers, the desired (meth) acrylate monomers are mixed at a predetermined mass ratio, and the resulting mixture is Xg (1 g) (total Mass) is precisely weighed in a flask, and this is used as a sample. To the sample thus prepared, 20 mL of an acetylating reagent (a solution obtained by adding pyridine to 20 mL of acetic anhydride to 400 mL) was accurately added. Next, an air cooling tube is attached to the mouth of the flask and heated in a glycerin bath at 95 to 100 ° C. After 1 hour and 30 minutes, the mixture is cooled, and 1 mL of purified water is added from an air cooling tube to decompose acetic anhydride into acetic acid. Next, titration is performed with a 0.5 mol / L potassium hydroxide ethanol solution using a potentiometric titrator, and the inflection point of the obtained titration curve is set as the end point. Further, as a blank test, titration is performed without a sample, and an inflection point of the titration curve is obtained. The hydroxyl value is calculated by the following formula (2).

In the above formula (2), B is the amount (mL) of 0.5 mol / L potassium hydroxide ethanol solution used for the blank test; C is 0.5 mol / L potassium hydroxide used for titration Amount of ethanol solution (mL); f is a factor of 0.5 mol / L potassium hydroxide ethanol solution; X is sample weight (g); D is acid value; 05 represents 1/2 of 1 mol amount 56.11 of potassium hydroxide.

The content of the polymer in the heat shield layer (in terms of solid content) is not particularly limited, but is preferably 20 to 90% by mass with respect to the heat shield layer from the viewpoint of the effect of improving the heat shield property, hard coat properties, and the like. More preferably, it is 20 to 80% by mass, and still more preferably 40 to 80% by mass. When the monomer component is formed by polymerization on a substrate, the above “content of polymer in the heat shielding layer (solid content conversion)” excludes the solvent of the coating solution for the heat shielding layer. It can also be regarded as the ratio (mass%) of the monomer component to the total mass of the components.

The method for producing the polymer according to the present invention is not particularly limited, and a known polymerization method can be applied in the same manner or appropriately modified. In addition, the preferable form of the manufacturing method (formation method of a heat shielding layer) of a polymer is explained in full detail below.

In addition to the above (a) and (b), the heat shielding layer essentially includes (c) a basic nitrogen-containing compound. The basic nitrogen-containing compound contains hydrogen ions generated by hydrolysis of carboxylic acid or carboxylate (COOR; R is an alkali metal or alkyl group) present in a polymer (a structural unit derived from a (meth) acrylate monomer). Trapping (neutralizing) suppresses a rise in the concentration of hydrogen ions existing in the heat shield layer over time. For this reason, the presence of the basic nitrogen-containing compound in the heat-shielding layer suppresses hydrolysis of the polymer, and increases the haze of the heat-shielding film (especially over time) even in a high-temperature and high-humidity environment. Rise) can be suppressed / prevented.

In the present specification, the term “basic” in a basic nitrogen-containing compound is intended to neutralize hydrogen ions generated by dissociation of a carboxylic acid or carboxylate of a polymer (particularly derived from a (meth) acrylate monomer). Used. Specifically, “basic” in the basic nitrogen-containing compound means that the pKa (acid dissociation constant) in the water of the conjugate acid of the basic nitrogen-containing compound is larger than the pKa in the water of the (meth) acrylate monomer. . Preferably, the ratio of the pKa in the water of the conjugate acid of the basic nitrogen-containing compound to the pKa in the water of the (meth) acrylate monomer is 1.05 to 2.5. With such a ratio, the basic nitrogen-containing compound sufficiently traps (neutralizes) hydrogen ions generated by hydrolysis of the carboxylic acid or carboxylate present in the polymer (particularly the (meth) acrylate monomer), Hydrolysis of the polymer can be more effectively suppressed.

Here, the basic nitrogen-containing compound is not particularly limited as long as it shows basicity and has a nitrogen atom, but 2,4,6-trimethylpyridine (boiling point = 171 ° C.), pyridine (boiling point = 115). ° C) and the like, amine compounds, oxime compounds, and imine compounds. Of these, amine compounds, oxime compounds, and imine compounds are preferred. That is, the basic nitrogen-containing compound is preferably at least one compound selected from the group consisting of amine compounds, oxime compounds, and imine compounds. In addition, the said basic nitrogen-containing compound may be used individually or may be used in combination of 2 or more types as appropriate.

The amine compound has the formula: N (X) (X ′) (X ″) (X, X ′ and X ″ each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, the number of carbon atoms 1 to 12 acyl groups or aryl groups, in which any two substituents of X, X ′ and X ″ may be linked to form a ring). In the above formula, X, X ′ and X ″ may be the same or different. Further, the alkyl group having 1 to 12 carbon atoms is not particularly limited, but is methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert. -Butyl, n-pentyl, isoamyl, neopentyl, tert-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, 2-ethylhexyl, nonyl, decyl And linear, branched or cyclic alkyl groups such as a group, undecyl group, dodecyl group, norbornyl group, adamantyl group, bicycloheptyl group, bicycloheptyl group, and bicyclooctyl group. The acyl group having 1 to 12 carbon atoms is not particularly limited, and examples thereof include formyl group, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group and the like. It is done. The aryl group is not particularly limited, and examples thereof include a phenyl group, a naphthyl group, a biphenyl group, a fluorenyl group, an anthryl group, a pyrenyl group, an azulenyl group, an acenaphthylenyl group, a terphenyl group, and a phenanthryl group. Specifically, the amine compounds include triethylamine (boiling point = 89 ° C.), N, N-diisopropylethylamine (boiling point = 127 ° C.), N, N-dipropylethylamine (boiling point = 132 ° C.), tripropylamine (boiling point). = 157 ° C), triisobutylamine (boiling point = 216 ° C), triisoamylamine (boiling point = 265 to 270 ° C), tri-n-octylamine (boiling point = 169 ° C), trinonylamine (boiling point = 466 ° C), Tridodecylamine (boiling point = 296 ° C / 1 mmHg), diisopropylamine (boiling point = 84 ° C), diisobutylamine (boiling point = 137 to 139 ° C), dipropylamine (boiling point = 108 ° C), tert-amylamine (boiling point = 77 ° C) ), Neopentylamine (boiling point = 83 ° C.), isoamylamine (boiling point = 97 ° C.), heptyl Min (boiling point = 154 ~ 156 ℃), and 2-ethylhexylamine (boiling point = 169 ° C.) and the like.

The oxime compound has the formula: HO—N═C (Y) (Y ′) (Y and Y ′ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or 1 carbon atom. And a multimer (for example, a dimer) thereof, which is an acyl group or an aryl group of ˜12, wherein Y and Y ′ may be linked to form a ring. In the above formula, Y and Y ′ may be the same or different. The alkyl group, acyl group, and aryl group having 1 to 12 carbon atoms are not particularly limited and have the same definition as the amine compound. Specifically, as the oxime compound, 2-butanone oxime (boiling point = 153 ° C.), 3,3-dimethyl-2-butanone oxime (boiling point = 172 ° C.), 4-methyl-2-pentanone oxime (boiling point = 69 ° C), cyclohexanone oxime (boiling point = 210 ° C), cyclopentanone oxime (boiling point = 196 ° C), cycloheptanone oxime (boiling point = 152 ° C), nioxime (boiling point = 189 ° C), acetaldoxime (boiling point = 115) ° C), acetophenone oxime (boiling point = 119 ° C), 2-adamantanone oxime (boiling point = 257 ° C), butyl aldoxime (boiling point = 153 ° C), (1R) -camphor oxime (boiling point = 243 ° C), diacetyl monooxime (Boiling point = 185 ° C.).

Further, the imine compound has the formula: Z—N═C (Z) (Z ′) (Z, Z ′ and Z ″ each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a carbon An acyl group or an aryl group having 1 to 12 atoms, wherein any two substituents of Z, Z ′ and Z ″ may be linked to form a ring, but Z, Z ′ and Z ″ is not a hydrogen atom). In the above formula, Z, Z ′ and Z ″ may be the same or different from each other. The alkyl group, acyl group, and aryl group having 1 to 12 carbon atoms are not particularly limited and have the same definition as the amine compound. Specifically, examples of the imine compound include benzophenone imine (boiling point = 181 ° C.), 2,2,4,4-tetramethyl-3-pentanone imine (boiling point = 164 ° C.), and the like.

For example, when the thermal barrier film of the present invention is used by being attached to a substrate (for example, glass), the film is considerably heated by sunlight. However, since the basic nitrogen-containing compound having the boiling point as described above does not volatilize from the heat-shielding layer, the effect (for example, the hydrolysis suppression effect of the polymerized product) due to the basic nitrogen-containing compound is longer. Can be demonstrated over a period of time. Considering the above points, the boiling point of the basic nitrogen-containing compound is preferably higher than 100 ° C., and preferably in the order of 120 ° C. or higher, 150 ° C. or higher, 160 ° C. or higher, 170 ° C. or higher, and 200 ° C. or higher. The upper limit of the boiling point of the basic nitrogen-containing compound is not particularly limited, but is usually 500 ° C. or lower. That is, the boiling point of the basic nitrogen-containing compound is particularly preferably 200 ° C. or higher.

The content of the basic nitrogen-containing compound in the heat-shielding layer (in terms of solid content) is not particularly limited, but from the viewpoint of improving the heat-shielding property and effectively suppressing the increase in haze over time, On the other hand, it is preferably 0.03 to 10% by mass, more preferably 0.05 to 5% by mass, and still more preferably 0.1 to 1% by mass. With such an amount, hydrogen ions generated by hydrolysis of the polymer ((meth) acrylate monomer) are trapped (neutralized) more efficiently, and even in a high temperature and high humidity environment, the haze of the thermal barrier film The rise (especially the rise over time) can be more effectively suppressed / prevented.

(Method of forming a thermal barrier layer)
The heat-shielding layer according to the present invention comprises (a) a tungsten oxide or the like, (b) a polymer of a monomer component having an acid value of 20 or less containing a (meth) acrylate monomer, and (c) a basic nitrogen-containing layer. The formation method is not particularly limited as long as the compound is essential. Although the preferable form of the formation method of the thermal-insulation layer concerning this invention is demonstrated below, this invention is not limited to the following form.

Specifically, the thermal barrier layer according to the present invention comprises (a) a tungsten oxide or the like, (b) a monomer component having an acid value of 20 or less including a (meth) acrylate monomer, and (c) a basic nitrogen-containing layer. It is formed by applying a coating solution for a thermal barrier layer containing a compound, a solvent and, if necessary, other additives added onto the substrate, and then irradiating ultraviolet rays to cure the coating film. The

First, a coating solution for a thermal barrier layer containing (a) a tungsten oxide or the like, (b) a monomer component containing an (meth) acrylate monomer having an acid value of 20 or less, and (c) a basic nitrogen-containing compound is prepared. . Since the details of (a) to (c) have been described above, the description thereof is omitted here.

The coating solution for the heat shielding layer may contain a solvent in addition to the essential components (a) to (c). The solvent is not particularly limited. For example, water, hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, 2-butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone) ), Esters (methyl acetate, ethyl acetate, n-butyl acetate, methyl lactate), glycol ethers, other organic solvents, etc., or a mixture thereof can be used.

The content of the solvent in the coating solution for the heat shielding layer is not particularly limited, but is generally about 10 to 80% by mass, more preferably 15 to 60% by mass with respect to the total mass of the coating solution. More preferably, it is 20 to 40% by mass.

Here, the concentration of tungsten oxide or the like in the coating solution for the heat shielding layer is not particularly limited, but is preferably such a concentration that the content of tungsten oxide or the like in the above-described heat shielding layer is obtained. Specifically, the concentration of tungsten oxide or the like in the heat shielding layer coating solution is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, from the viewpoint of the heat shielding improvement effect. The concentration of the (meth) acrylate monomer in the heat shielding layer coating solution is not particularly limited, but is preferably such a concentration that the content of the polymer in the heat shielding layer described above is obtained. Specifically, the concentration of the (meth) acrylate monomer in the coating solution for the heat shielding layer is preferably 10 to 50% by mass, more preferably 20 to 35%, from the viewpoint of adjusting the hardness and film modulus to desired values. % By mass. The concentration of the basic nitrogen-containing compound in the coating solution for the heat-shielding layer is not particularly limited, but is preferably such a concentration that the content of the basic nitrogen-containing compound in the above-described heat-shielding layer is obtained. Specifically, the concentration of the basic nitrogen-containing compound in the coating solution for the heat shielding layer is preferably 0.005 to 5% by mass, more preferably 0.01 to 5% from the viewpoint of further improving the trapping efficiency of hydrogen ions. 1% by mass.

The coating solution for the heat shielding layer may contain various additives as necessary. Examples of the additive include a photopolymerization initiator, a surfactant for imparting leveling properties, water repellency, slipperiness, and the like; a dye, a pigment, a sensitizer and the like for improving curability by ultraviolet irradiation. .

Further, the type of the photopolymerization initiator is not particularly limited, and examples thereof include a cationic photopolymerization initiator, an anionic photopolymerization initiator, and a radical photopolymerization initiator. From the viewpoint of curability and productivity, A radical photopolymerization initiator is preferred.

The radical photopolymerization initiator is not particularly limited, and for example, acylphosphine oxides, acetophenones, anthraquinones, thioxanthones, ketals, benzophenones and azo compounds can be used. Acylphosphine oxides are not particularly limited, and examples thereof include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, and bis (2,6-dimethoxybenzoyl). ) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, and the like. The acetophenones are not particularly limited. For example, benzoin and its alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzylmethyl ketal; acetophenone, 2,2- Examples include dimethoxy-2-phenylacetophenone and 1-hydroxycyclohexyl phenyl ketone. The anthraquinones are not particularly limited, and examples thereof include methylanthraquinone, 2-ethylanthraquinone, 2-amylanthraquinone and the like. The thioxanthones are not particularly limited, and examples thereof include thioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone and the like. The ketals are not particularly limited, and examples thereof include acetophenone dimethyl ketal and benzyl dimethyl ketal. The benzophenones are not particularly limited, and examples thereof include benzophenone and 4,4-bismethylaminobenzophenone.

For example, commercially available products such as Irgacure (registered trademark) 184, 651, 1173, 819, LUCIRIN (registered trademark) TPO manufactured by BASF Japan are also used as appropriate.

These photopolymerization initiators can be used alone or in combination of two or more. The amount of these photopolymerization initiators used is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass with respect to 100 parts by mass of the monomer component including the (meth) acrylate monomer. .

Further, the type of the surfactant is not particularly limited, and a fluorosurfactant, an acrylic surfactant, a silicone surfactant, and the like can be used. In particular, a fluorosurfactant is preferably used from the viewpoint of leveling properties, water repellency, and slipperiness of the coating solution. Examples of the fluorosurfactant include, for example, Megafac (registered trademark) F series (F-430, F-477, F-552 to F-559, F-561, F-562, etc., manufactured by DIC Corporation. ), Megafuck (registered trademark) RS series (RS-76-E, etc.) manufactured by DIC Corporation, Surflon (registered trademark) series manufactured by AGC Seimi Chemical Co., Ltd., POLYFOX series manufactured by OMNOVA SOLUTIONS Corporation, T & K TOKA Corporation Commercially available products such as ZX series, Optool (registered trademark) series manufactured by Daikin Industries, Ltd., and Footgent (registered trademark) series (602A, 650A, etc.) manufactured by Neos Corporation can be used. Examples of the acrylic surfactant include Polyflow Series (manufactured by Kyoeisha Chemical Co., Ltd.), New Coal Series (manufactured by Nippon Emulsifier Co., Ltd.), and BYK (registered trademark) -354 (manufactured by Big Chemie Japan Co., Ltd.). Examples of the silicone-based surfactant include BYK (registered trademark) -345, BYK (registered trademark) -347, BYK (registered trademark) -348, BYK (registered trademark) -349 (manufactured by BYK Japan). . Surfactants may be used alone or in admixture of two or more. The surfactant is preferably contained in an amount of 0.01% by mass or more and 1% by mass or less based on the total mass of the components excluding the solvent of the coating solution for the heat shielding layer.

The coating solution for the heat shielding layer is adjusted by mixing the above components. The order of addition and the addition method are not particularly limited, and each component may be added and mixed sequentially while stirring, or may be added and mixed all at once while stirring.

Moreover, there is no restriction | limiting in particular also about the method of apply | coating the coating liquid for heat-shielding layers on a base material (the surface of a base material, or the surface of the outermost layer arrange | positioned on a base material), For example, coating by a well-known method, for example, a wire bar Techniques such as spin coating and dip coating can be employed. Further, it can be applied by a continuous coating apparatus such as a die coater, a gravure coater or a comma coater.

The drying conditions after application are not particularly limited. For example, the drying temperature is preferably 70 to 110 ° C. The drying time is preferably 30 seconds to 5 minutes.

Thereafter, the coating film obtained by applying the thermal barrier layer coating liquid on the substrate is irradiated with ultraviolet rays from the side of the coating film far from the substrate to cure the coating film. In this case, the conditions such as the irradiation wavelength, the illuminance, and the light quantity of the ultraviolet rays vary depending on the type of the ultraviolet curable monomer and the polymerization initiator to be used. For example, when an ultraviolet lamp is used, the illuminance is preferably 50 to 1500 mW / cm ² and the irradiation energy amount is preferably 50 to 1500 mJ / cm ² .

[Functional layer]
The heat shield film according to one embodiment of the present invention may have a functional layer in addition to the base material and the heat shield layer. The type of the functional layer is not particularly limited, but will be specifically described below with an example in which the functional layer is a dielectric multilayer film (hereinafter also referred to as “reflection layer”).

(Dielectric multilayer film)
Another embodiment of the present invention is a thermal barrier film including a dielectric multilayer film in which high refractive index layers and low refractive index layers are alternately stacked.

The dielectric multilayer film (reflective layer) has a configuration in which low refractive index layers and high refractive index layers are alternately stacked. The high refractive index layer and the low refractive index layer are considered as follows.

For example, a component that constitutes a high refractive index layer (hereinafter referred to as a high refractive index layer component) and a component that constitutes a low refractive index layer (hereinafter referred to as a low refractive index layer component) are mixed at the interface between the two layers. A layer (mixed layer) including a refractive index layer component and a low refractive index layer component may be formed. In this case, in the mixed layer, a set of portions where the high refractive index layer component is 50% by mass or more is defined as a high refractive index layer, and a set of portions where the low refractive index layer component exceeds 50% by mass is defined as a low refractive index layer. . Specifically, when the low refractive index layer contains, for example, a first metal oxide as a low refractive index component, and the high refractive index layer contains a second metal oxide as a high refractive index component The metal oxide concentration profile in the film thickness direction in these laminated films is measured, and can be regarded as a high refractive index layer or a low refractive index layer depending on the composition. The metal oxide concentration profile of the laminated film is sputtered from the surface in the depth direction using a sputtering method, and is sputtered at a rate of 0.5 nm / min using the XPS surface analyzer with the outermost surface being 0 nm. It can be observed by measuring the atomic composition ratio. In addition, a laminate in which metal oxide particles are not contained in the low refractive index component or the high refractive index component, and one of the high refractive index layer or the low refractive index layer is formed only from a water-soluble resin (organic binder). Similarly, in the water-soluble resin (organic binder) concentration profile, for example, the carbon concentration in the film thickness direction is measured to confirm that the mixed region exists, and the composition is further changed to EDX. Thus, each layer etched by sputtering can be regarded as a high refractive index layer or a low refractive index layer.

The reflective layer may have a structure having at least one laminate (unit) in which a high refractive index layer and a low refractive index layer containing a polymer are alternately laminated on a substrate. The number of low refractive index layers (total number of refractive index layers) is not particularly limited, but is preferably 6 to 2000 (that is, 3 to 1000 units), more preferably 10 to 1500 (that is, 5 to 5). 750 units), more preferably 10 to 1000 (that is, 5 to 500 units). If the number of layers exceeds 2000, haze is likely to occur, and if it is less than 6, the desired reflectance may not be achieved. Moreover, the thermal insulation film which concerns on one form of this invention should just be the structure which has at least 1 or more units on the said base material.

In the dielectric multilayer film, the high refractive index layer preferably has a higher refractive index, but the refractive index is preferably 1.70 to 2.50, more preferably 1.80 to 2.20, It is preferably 1.90 to 2.20. The low refractive index layer preferably has a lower refractive index, but the refractive index is preferably 1.10 to 1.60, more preferably 1.30 to 1.55, and still more preferably 1. 30 to 1.50.

In the dielectric multilayer film, it is preferable to design a large difference in refractive index between the high refractive index layer and the low refractive index layer from the viewpoint of increasing the infrared reflectance with a small number of layers. In at least one of the units composed of the high refractive index layer and the low refractive index layer, the difference in refractive index between the adjacent high refractive index layer and low refractive index layer is preferably 0.1 or more, more preferably Is 0.2 or more, more preferably 0.25 or more. When the dielectric multilayer film has a plurality of units of a low refractive index layer and a high refractive index layer, the refractive index difference between the low refractive index layer and the high refractive index layer in all the units is within the preferred range. Is preferred. However, the outermost layer and the lowermost layer of the dielectric multilayer film may have a configuration outside the above preferred range.

The reflectance in a specific wavelength region is determined by the difference in refractive index between two adjacent layers (high refractive index layer and low refractive index layer) and the number of layers, and the larger the refractive index difference, the same reflectance can be obtained with fewer layers. . The refractive index difference and the required number of layers can be calculated using commercially available optical design software. For example, in order to obtain an infrared reflectivity (infrared shielding rate) of 90% or more, if the difference in refractive index is smaller than 0.1, a laminate exceeding 100 layers is required, which not only reduces productivity. , Scattering at the laminated interface increases and transparency decreases. From the viewpoint of improving the reflectance and reducing the number of layers, there is no upper limit to the difference in refractive index, but it is substantially about 1.4.

The refractive index is obtained as a difference between the high refractive index layer and the low refractive index layer according to the following method. That is, each refractive index layer is formed as a single layer (using a base material if necessary), and after cutting this sample into 10 cm × 10 cm, the refractive index is obtained according to the following method. Using a U-4000 type (manufactured by Hitachi, Ltd.) as a spectrophotometer, the surface opposite to the measurement surface (back surface) of each sample is roughened, and then light absorption is performed with a black spray. Then, the reflection of light on the back surface is prevented, and the average value is obtained by measuring 25 points of reflectance in the visible light region (400 nm to 700 nm) under the condition of regular reflection at 5 degrees, and the average refractive index is determined from the measurement result. Ask.

Since reflection at the interface between adjacent layers depends on the refractive index ratio between layers, the larger this refractive index ratio, the higher the reflectance. In addition, when the optical path difference between the reflected light on the surface of the layer and the reflected light on the bottom of the layer is a relationship expressed by n · d = wavelength / 4 when viewed as a single layer film, the reflected light is controlled to be strengthened by the phase difference. The reflectance can be increased. Here, n is the refractive index, d is the physical film thickness of the layer, and n · d is the optical film thickness. By using this optical path difference, reflection can be controlled. Using this relationship, the refractive index and film thickness of each layer are controlled to control the reflection of visible light and near infrared light. That is, the reflectance in a specific wavelength region can be increased by the refractive index of each layer, the film thickness of each layer, and the way of stacking each layer.

The dielectric multilayer film can be made into a visible light reflection film or a near infrared reflection film by changing a specific wavelength region for increasing the reflectance. That is, if the specific wavelength region for increasing the reflectance is set to the visible light region, the visible light reflecting film is obtained, and if the specific wavelength region is set to the near infrared region, the near infrared reflecting film is obtained. Moreover, if the specific wavelength area | region which raises a reflectance is set to an ultraviolet light area | region, it will become an ultraviolet reflective film. In the case of using a dielectric multilayer film in the heat shield film according to one embodiment of the present invention, a (near) infrared reflection (shield) film may be used. In the case of an infrared reflective film, the transmittance at 550 nm in the visible light region shown in JIS R3106: 1998 is preferably 50% or more, more preferably 70% or more, and 75% or more. Further preferred. Further, the transmittance at 1200 nm is preferably 35% or less, more preferably 25% or less, and further preferably 20% or less. It is preferable to design the optical film thickness and unit so as to be in such a suitable range. In addition, it is preferable that the region having a wavelength of 900 nm to 1400 nm has a region with a reflectance exceeding 50%.

[Low refractive index layer and high refractive index layer]
In this specification, the terms “high refractive index layer” and “low refractive index layer” refer to a refractive index layer having a higher refractive index when comparing the refractive index difference between two adjacent layers. It means that the lower refractive index layer is a low refractive index layer. Therefore, the terms “high refractive index layer” and “low refractive index layer” mean that when each refractive index layer constituting the dielectric multilayer film is focused on two adjacent refractive index layers, All forms other than those having the same refractive index are included.

The thickness of the refractive index layer per layer (thickness after drying) is preferably 20 to 1000 nm, more preferably 50 to 500 nm, still more preferably 100 to 300 nm, and even more preferably 100 to 200 nm. It is particularly preferred that The thickness per layer of the refractive index layer can be adjusted by changing the width in the film thickness direction at the die extrusion port and / or by stretching conditions. In addition, when extending | stretching a laminated body, the said film thickness shows the thickness after extending | stretching.

[Polymer material]
The low refractive index layer and the high refractive index layer essentially contain a polymer material. If the refractive index layer is formed of a polymer material, a film forming method such as coating or spin coating can be selected. Since these methods are simple and do not ask the heat resistance of a base material, there are many choices, and it can be said that it is an effective film forming method particularly for a resin base material. For example, a mass production method such as a roll-to-roll method can be adopted for the coating type, which is advantageous in terms of cost and process time. Moreover, since the film | membrane containing a polymer material has high flexibility, even if it winds up at the time of production or conveyance, these defects do not generate easily and there exists an advantage that it is excellent in handleability.

The polymer contained in the refractive index layer is not particularly limited, and specific examples include polyethylene terephthalate (PET), a copolymer of polyethylene terephthalate (coPET), poly (methyl methacrylate) (PMMA), and poly (methyl Methacrylate) copolymer (coPMMA), cyclohexanedimethanol (PETG), cyclohexanedimethanol copolymer (coPETG), polyethylene naphthalate (PEN) polyethylene naphthalate copolymer (coPEN), polyethylene naphthalate, polyethylene naphthalate copolymer, Examples include, but are not limited to, poly (methyl methacrylate) and copolymers of poly (methyl methacrylate). For each high refractive index layer and low refractive index layer, one or a combination of two or more of these polymers can be used. Examples of suitable polymer combinations include those described in US Pat. No. 6,352,761. Moreover, it is also possible to form a reflective layer using the said polymer with a continuous flat film manufacturing line, for example by a coextrusion method or a co-casting method.

The polymer contained in the high refractive index layer and the low refractive index layer is preferably a water-soluble polymer that functions as a binder. The high refractive index layer and the low refractive index layer preferably contain a water-soluble polymer, so that environmental problems due to the organic solvent can be solved and the flexibility of the coating film can be achieved. The polymers contained in the high refractive index layer and the low refractive index layer may be the same component or different components, but are preferably different. Examples of the water-soluble polymer include gelatin, thickening polysaccharides, polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate- Acrylic resin such as acrylic acid ester copolymer or acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer Styrene-acrylic resin such as styrene-α-methylstyrene-acrylic acid copolymer or styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-sodium styrenesulfonate copolymer, styrene- 2-hydroxyethyl acrylate Copolymer, styrene-2-hydroxyethyl acrylate-potassium styrene sulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic Examples thereof include acid copolymers, vinyl acetate-maleic acid ester copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate copolymers such as vinyl acetate-acrylic acid copolymers, and the like. Among these, from the viewpoint of improving effects such as coating unevenness and film thickness uniformity (haze), the refractive index layer preferably contains polyvinyl alcohol which is a polyvinyl alcohol or a derivative thereof as a polymer. A polymer may be used independently and may be used in combination of 2 or more type. The polymer may be a synthetic product or a commercially available product.

The polymer is not particularly limited, and known polymers used for the high refractive index layer and the low refractive index layer, such as International Publication No. 2012/128109, JP2013-121567A, JP2013-148849A, and the like. Can be used in the same way. Specifically, the polyvinyl alcohol-based resin includes various modified polyvinyl alcohols in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate.

The polyvinyl alcohol obtained by hydrolyzing vinyl acetate preferably has an average degree of polymerization of 1,000 or more, and particularly preferably an average degree of polymerization of 1,500 to 5,000. The degree of saponification is preferably 70 to 100 mol%, particularly preferably 80 to 99.9 mol%.

Examples of the modified polyvinyl alcohol include cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, nonion-modified polyvinyl alcohol, ethylene-modified polyvinyl alcohol, and vinyl alcohol polymers.

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

Nonionic modified polyvinyl alcohol includes, for example, a polyvinyl alcohol derivative in which a polyalkylene oxide group is added to a part of vinyl alcohol as described in JP-A-7-9758, and JP-A-8-25795. Block copolymer of vinyl compound having hydrophobic group and vinyl alcohol as described, silanol modified polyvinyl alcohol having silanol group, reactivity having reactive group such as acetoacetyl group, carbonyl group, carboxyl group Examples thereof include group-modified polyvinyl alcohol.

Examples of the cation-modified polyvinyl alcohol include primary to tertiary amino groups and quaternary ammonium groups as described in JP-A No. 61-10383. Polyvinyl alcohol contained therein and obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a cationic group and vinyl acetate.

As the ethylene-modified polyvinyl alcohol, for example, those described in JP-A-2009-107324, JP-A-2003-248123, JP-A-2003-342322, and Japanese Patent Application No. 2013-206913 can be used. Alternatively, commercially available products such as EXEVAL (trade name: manufactured by Kuraray Co., Ltd.) may be used.

Examples of the vinyl alcohol-based polymer include EXEVAL (trade name: manufactured by Kuraray Co., Ltd.), Nichigo G polymer (trade name: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and polyvinyl acetal resin obtained by reacting polyvinyl alcohol with an aldehyde ( For example, “S REC” manufactured by Sekisui Chemical Co., Ltd., silanol-modified polyvinyl alcohol having a silanol group (for example, “R-1130” manufactured by Kuraray Co., Ltd.), modified polyvinyl alcohol-based resin having an acetoacetyl group in the molecule (for example, And “Gosefimer (registered trademark) Z / WR series” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.).

In addition, the above-mentioned polyvinyl alcohol may be used alone or in combination of two or more. Polyvinyl alcohol may be a synthetic product or a commercial product.

The mass average molecular weight of polyvinyl alcohol is preferably 60,000 to 250,000. In this specification, the value measured by static light scattering, gel permeation chromatography (GPC), TOFMASS, etc. is adopted as the value of “mass average molecular weight”. When the weight average molecular weight of the water-soluble polymer is in the above range, it is preferable because application in a wet film forming method is possible and productivity can be improved.

The content of the water-soluble polymer in the refractive index layer is preferably 5 to 75% by mass, and more preferably 10 to 70% by mass with respect to the total solid content of the refractive index layer. When the refractive index layer is formed by a wet film-forming method when the content of the water-soluble polymer is 5% by mass or more, the transparency of the film surface is disturbed when the coating film obtained by coating is dried. This is preferable because it is possible to prevent the deterioration. On the other hand, when the content of the water-soluble polymer is 75% by mass or less, the content is suitable when the metal oxide particles are contained in the refractive index layer, and the refractive index between the low refractive index layer and the high refractive index layer. This is preferable because the rate difference can be increased. In addition, in this specification, content of water-soluble polymer is calculated | required from the residual solid content of the evaporation-drying method. Specifically, the thermal barrier film is immersed in hot water at 95 ° C. for 2 hours, and the remaining film is removed, and then the hot water is evaporated, and the amount of the obtained solid matter is made the water-soluble high molecular weight. At this time, when one peak is observed in each of the regions of 1700 to 1800 cm ⁻¹ , 900 to 1000 cm ⁻¹ , and 800 to 900 cm ^{−1 in} the IR (infrared spectroscopy) spectrum, the water-soluble polymer is polyvinyl alcohol. It can be determined that

[Metal oxide particles]
At least one of the low refractive index layer or the high refractive index layer may contain a metal oxide (particle). By containing metal oxide particles, the refractive index difference between the refractive index layers can be increased, and the reflection characteristics are improved. When both the low refractive index layer and the high refractive index layer contain metal oxide particles, the refractive index difference can be further increased. By including metal oxide particles, the number of stacked layers can be reduced and a thin film can be obtained. By reducing the number of layers, productivity can be improved and a decrease in transparency due to scattering at the lamination interface can be suppressed.

As the metal oxide particles, the metal constituting the metal oxide is Li, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Nb, Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, La, Ta, Hf, W, Ir, Tl, Pb, Bi and a rare earth metal A metal oxide which is one kind or two or more kinds of metals can be used.

《Metal oxide particles in high refractive index layer》
Examples of the metal oxide particles used in the high refractive index layer include titanium dioxide, 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, magnesium hydroxide, strontium titanate, yttrium oxide, hafnium oxide, niobium oxide, tantalum oxide, barium oxide, indium oxide, europium oxide, lanthanum oxide, zircon, tin oxide, lead oxide, and Examples thereof include lithium niobate, potassium niobate, lithium tantalate, and aluminum / magnesium oxide (MgAl ₂ O ₄ ), which are double oxides composed of these oxides.

In addition, rare earth oxides can also be used as the metal oxide particles. Specifically, scandium oxide, yttrium oxide, lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, and oxidation. Examples also include terbium, dysprosium oxide, holmium oxide, erbium oxide, thulium oxide, ytterbium oxide, and lutetium oxide.

The metal oxide particles used in the high refractive index layer are preferably metal oxide particles having a refractive index of 1.90 or more, and examples thereof include zirconium oxide, cerium oxide, titanium oxide, and zinc oxide. Among them, titanium dioxide is preferable because it can form a transparent and higher refractive index layer having a higher refractive index, and it is particularly preferable to use rutile (tetragonal) titanium oxide particles. The metal oxide particles used for the high refractive index layer may be used singly or in combination of two or more.

The volume average particle size of the metal oxide particles used for the metal oxide particles used in the high refractive index layer is preferably 100 nm or less, more preferably 1 to 30 nm, and more preferably 5 to 15 nm. Further preferred.

As the titanium oxide particles, those obtained by modifying the surface of the titanium oxide sol so as to be dispersible in water or an organic solvent are preferably used. Examples of the preparation method of the aqueous titanium oxide sol include, for example, JP-A-63-17221, JP-A-7-819, JP-A-9-165218, JP-A-11-43327, JP-A-63-3. Reference can be made to the matters described in Japanese Patent No. 17221.

The average particle diameter of titanium oxide used for the metal oxide particles used in the high refractive index layer is preferably 100 nm or less, more preferably 50 nm or less, and the viewpoint that the haze value is low and the visible light transmittance is excellent. 1 to 30 nm is more preferable, and 1 to 20 nm is more preferable. If the volume average particle size is in the above range, it is preferable from the viewpoint of low haze and excellent visible light transmittance. Here, the average particle diameter means a method of observing the particle itself using a laser diffraction scattering method, a dynamic light scattering method, or an electron microscope, or a particle image appearing on the cross section or surface of the refractive index layer. The particle diameters of 1,000 arbitrary particles are measured by the method of observing the above, and particles having particle diameters of d1, d2,. In a group of nk particulate metal oxides, when the volume per particle is vi, the average particle size mv = {Σ (vi · di)} / {Σ (vi)} The volume average particle size weighted by the volume to be measured.

Alternatively, it may be in the form of core-shell particles in which titanium oxide is coated with a silicon-containing hydrated oxide. The core-shell particles have a structure in which the surface of the titanium oxide particles is coated with a shell made of a silicon-containing hydrated oxide on a titanium oxide serving as a core. By including such core-shell particles in the high refractive index layer, the intermixing of the low refractive index layer and the high refractive index layer is achieved by the interaction between the silicon-containing hydrated oxide of the shell layer and the water-soluble resin. Can be suppressed. Here, the “coating” means a state in which a silicon-containing hydrated oxide is attached to at least a part of the surface of the titanium oxide particles. That is, the surface of the titanium oxide particles used as the metal oxide particles may be completely covered with a silicon-containing hydrated oxide, and a part of the surface of the titanium oxide particles is a silicon-containing hydrated oxide. It may be coated. From the viewpoint that the refractive index of the coated titanium oxide particles is controlled by the coating amount of the silicon-containing hydrated oxide, it is preferable that a part of the surface of the titanium oxide particles is coated with the silicon-containing hydrated oxide. . Hereinafter, such coated titanium oxide particles are also referred to as “silica-attached titanium dioxide sol”.

The titanium oxide of the titanium oxide particles coated with the silicon-containing hydrated oxide may be a rutile type or an anatase type, but a rutile type is more preferable. This is because rutile-type titanium oxide particles have lower photocatalytic activity than anatase-type titanium oxide particles, which increases the weather resistance of the high refractive index layer and the adjacent low refractive index layer, and further increases the refractive index. is there.

The “silicon-containing hydrated oxide” in this specification may be any of a hydrate of an inorganic silicon compound, a hydrolyzate and / or a condensate of an organosilicon compound, and the effect according to one embodiment of the present invention. It is more preferable to have a silanol group in order to obtain

The coating amount of the silicon-containing hydrated oxide is 3 to 30% by mass, preferably 3 to 10% by mass, and more preferably 3 to 8% by mass with respect to the metal oxide particles. This is because when the coating amount is 30% by mass or less, it is easy to increase the refractive index of the high refractive index layer, and when the coating amount is 3% by mass or more, the coated particles can be stably formed.

As a method of coating the titanium oxide particles with a silicon-containing hydrated oxide, it can be produced by a conventionally known method. For example, JP-A-10-158015, JP-A-2000-204301, JP-A-2007 Reference can be made to the matters described in Japanese Patent No. 246351.

In general, titanium oxide particles are often used in a surface-treated state for the purpose of suppressing the photocatalytic activity of the particle surface and improving dispersibility in a solvent, etc. Silica, alumina, aluminum hydroxide, zirconia, and the like are preferably treated with one or more of them. More specifically, the surface of the titanium oxide particle is covered with a coating layer made of silica, and the surface of the particle is negatively charged, or the surface is positively charged at a pH of 8 to 10 where a coating layer made of aluminum oxide is formed. The one that bears is known.

As the content of the metal oxide particles in the high refractive index layer, with respect to the solid content of 100% by mass of the high refractive index layer, the viewpoint of infrared shielding and the reduction of color unevenness when a film is applied to curved glass From the viewpoint, it is preferably 20 to 80% by mass, more preferably 30 to 75% by mass, and further preferably 40 to 70% by mass.

<< Metal oxide particles in the low refractive index layer >>
As the metal oxide particles mainly used in the low refractive index layer, it is preferable to use silicon dioxide as the metal oxide particles, and it is particularly preferable to use colloidal silica. The metal oxide particles (preferably silicon dioxide) contained in the low refractive index layer preferably have an average particle size of 3 to 100 nm. The average particle diameter of primary particles of silicon dioxide dispersed in a primary particle state (particle diameter in a dispersion state before coating) is more preferably 3 to 50 nm, and further preferably 3 to 40 nm. It is particularly preferably 3 to 20 nm, and most preferably 4 to 10 nm. Moreover, as an average particle diameter of secondary particle | grains, it is preferable from a viewpoint with few hazes and excellent visible light transmittance | permeability that it is 30 nm or less. The average particle size of the metal oxide in the low refractive index layer is determined by observing the particles themselves or the cross section or surface of the refractive index layer with an electron microscope and measuring the particle size of 1,000 arbitrary particles. The simple average value (number average) is obtained. Here, the particle diameter of each particle is represented by a diameter assuming a circle equal to the projected area.

The content of the metal oxide particles in the low refractive index layer is preferably 5 to 80% by mass with respect to the solid content of the low refractive index layer, and preferably 10 to 75% by mass from the viewpoint of refractive index. More preferably.

Colloidal silica is obtained by heating and aging a silica sol obtained by metathesis of sodium silicate with an acid or the like or passing through an ion exchange resin layer. For example, JP-A-57-14091 and JP-A-60- No. 219083, JP-A-60-218904, JP-A-61-20792, JP-A-61-188183, JP-A-63-17807, JP-A-4-93284, JP-A-5-278324, JP-A-6-92011, JP-A-6-183134, JP-A-6-297830, JP-A-7-81214, JP-A-7-101142, JP-A-7- 179029, JP-A-7-137431, and International Publication No. 94/26530. Such colloidal silica may be a synthetic product or a commercially available product. The surface of the colloidal silica may be cation-modified, or may be treated with Al, Ca, Mg, Ba or the like.

Such colloidal silica may be a synthetic product or a commercially available product. Examples of commercially available products include the Snowtex series (Snowtex OS, OXS, S, OS, 20, 30, 40, O, N, C, etc.) sold by Nissan Chemical Industries.

(Other additives)
In addition to the above, each refractive index layer includes, for example, ultraviolet absorbers described in JP-A-57-74193, JP-A-57-87988, and JP-A-62-261476, and JP-A-57-74192. JP-A-57-87989, JP-A-60-72785, JP-A-61465991, JP-A-1-95091 and JP-A-3-13376, etc. No. 42993, 59-52689, 62-280069, 61-242871, and JP-A 4-219266, etc., optical brighteners, sulfuric acid, phosphoric acid, acetic acid PH adjusters such as citric acid, sodium hydroxide, potassium hydroxide, potassium carbonate, antifoaming agents, lubricants such as diethylene glycol, preservatives, antistatic agents, Various known additives such as DOO agent may contain. The content of these additives is preferably 0.1 to 10% by mass with respect to the solid content of the refractive index layer.

Alternatively, when each refractive index layer contains a water-soluble polymer, a curing agent can be used to cure the water-soluble polymer. Curing agents include boric acid and its salts, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-diglycidylcyclohexane, N, N-diglycidyl-4-glycidyloxyaniline, sorbitol polyglycidyl Ether, glycerol polyglycidyl ether, etc.), aldehyde-based curing agents (formaldehyde, glyoxal, etc.), active halogen-based curing agents (2,4-dichloro-4-hydroxy-1,3,5, -s-triazine, etc.), active Examples thereof include vinyl compounds (1,3,5-trisacryloyl-hexahydro-s-triazine, bisvinylsulfonylmethyl ether, etc.), aluminum alum, borax and the like. The content of the curing agent in the refractive index layer is preferably 1 to 10% by mass with respect to the solid content of the refractive index layer.

Alternatively, each refractive index layer may contain a surfactant for adjusting the surface tension at the time of application. Here, an anionic surfactant, a nonionic surfactant, an amphoteric surfactant, and the like can be used as the surfactant, and an anionic surfactant is more preferable. Preferable compounds include those containing a hydrophobic group having 8 to 30 carbon atoms and a sulfonic acid group or a salt thereof in one molecule. The content of the surfactant in each refractive index layer is preferably 0.01 to 5% by mass with respect to the solid content of the refractive index layer.

The method for producing the dielectric multilayer film is not particularly limited, and examples thereof include a method of forming by coating and drying a coating solution for a high refractive index layer and a coating solution for a low refractive index layer.

The method for preparing the coating solution for the high refractive index layer and the coating solution for the low refractive index layer is not particularly limited, and the monomer component, the metal oxide particles, the basic nitrogen-containing compound, and others added as necessary And a method of adding a solvent and stirring and mixing. At this time, the order of addition of the respective components is not particularly limited, and the respective components may be sequentially added and mixed while stirring, or may be added and mixed all at once while stirring. If necessary, it may be adjusted to an appropriate viscosity using a solvent.

Further, when adjusting the coating solution for forming the low refractive index layer, it may be prepared while heating appropriately.

Here, the solvent for adjusting the coating solution for the high refractive index layer and the coating solution for the low refractive index layer is not particularly limited, but water, an organic solvent, or a mixed solvent thereof is preferable. In consideration of environmental aspects due to the scattering of the organic solvent, water or a mixed solvent of water and a small amount of an organic solvent is more preferable, and water is particularly preferable. Examples of the organic solvent include alcohols such as methanol, ethanol, 2-propanol and 1-butanol, esters such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate, diethyl ether, Examples thereof include ethers such as propylene glycol monomethyl ether and ethylene glycol monoethyl ether, amides such as dimethylformamide and N-methylpyrrolidone, and ketones such as acetone, methyl ethyl ketone, acetylacetone and cyclohexanone. These organic solvents may be used alone or in combination of two or more. From the viewpoint of environment and simplicity of operation, the solvent of the coating solution is preferably water or a mixed solvent of water and methanol, ethanol, or ethyl acetate, and more preferably water.

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

Next, using the coating solution for the high refractive index layer and the coating solution for the low refractive index layer prepared as described above, the coating is applied on the substrate and dried to form a dielectric multilayer film.

The coating method is not particularly limited and may be either a sequential coating method or a simultaneous multilayer coating method, but a simultaneous multilayer coating method is preferable from the viewpoint of productivity and the like.

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

The temperature of the coating solution for the high refractive index layer and the coating solution for the low refractive index layer at the time of simultaneous multilayer coating is preferably 25 to 60 ° C., and 35 to 50 ° C. when using the slide bead coating method. A temperature range is more preferred. When the curtain coating method is used, a temperature range of 25 to 60 ° C. is preferable, and a temperature range of 30 to 45 ° C. is more preferable.

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

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

Specific coating and drying methods are not particularly limited, but when a reflective film is formed by a sequential coating method, the coating solution for low refractive index layer and the high refractive index layer heated to 25 to 60 ° C. One of the coating liquids is applied onto a substrate and dried to form a layer, and then the other coating liquid is applied onto this layer and dried to form a layer. This is sequentially applied so that the number of layers necessary for expressing the desired reflection performance is obtained, thereby obtaining a reflection film precursor. When drying, it is preferable to dry the formed coating film at 30 ° C. or higher. For example, it is preferable to dry in the range of 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 85 ° C. is blown for 1 to 5 seconds. dry. As a drying method, warm air drying, infrared drying, and microwave drying are used. In addition, it is preferable to perform a multi-stage process rather than a single process, and it is more preferable that the temperature of the constant rate drying unit is less than the temperature of the rate-decreasing drying unit. In this case, the temperature range of the constant rate drying section is preferably 30 to 60 ° C., and the temperature range of the decreasing rate drying section is preferably 50 to 100 ° C.

When a reflective layer is formed by simultaneous multilayer coating, the coating solution for the low refractive index layer and the coating solution for the high refractive index layer are heated to 25 to 60 ° C., and are applied to the low refractive index layer on the substrate. After simultaneous multi-layer coating of the coating solution and the coating solution for the high refractive index layer, the temperature of the formed coating film is preferably cooled (set) preferably to 1 to 15 ° C. and then dried at 10 ° C. or higher. . More preferable drying conditions are a wet bulb temperature of 5 to 50 ° C. and a film surface temperature of 10 to 50 ° C. For example, it is dried by blowing warm air at 80 ° C. for 1 to 5 seconds. Moreover, as a cooling method immediately after application | coating, it is preferable to carry out by a horizontal set system from a viewpoint of the uniformity improvement of the formed coating film.

Here, the set means that the viscosity of the coating composition is increased by means such as lowering the temperature by applying cold air or the like to the coating film, and the fluidity of the substances in each layer or in each layer is reduced or gelled. It means a process. A state in which the cold air is applied to the coating film from the surface and the finger is pressed against the surface of the coating film is defined as a set completion state.

The temperature of the cold air used in the setting process is preferably 0 to 25 ° C, more preferably 5 to 10 ° C. The time (setting time) from the time of application until the setting is completed by applying cold air is preferably within 7 minutes, and more preferably within 5 minutes. Further, the lower limit time is not particularly limited, but it is preferable to take 45 seconds or more. By setting the set time to a certain value or more, the components in the layer can be sufficiently mixed. On the other hand, by setting the set time to a short time, the interlayer diffusion of the metal oxide nanoparticles can be prevented, and the difference in refractive index between the high refractive index layer and the low refractive index layer can be made desirable. In the case where high elasticity occurs quickly at the interface between the high refractive index layer and the low refractive index layer, a suitable interface can be formed without providing a setting step.

In addition to changing the concentration of the water-soluble resin and the concentration of the metal oxide nanoparticles, the set time includes other components such as gelatin, pectin, agar, carrageenan, gellan gum and other known gelling agents. It can adjust by adding.

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

The configuration of the functional layer is specifically described by taking the case where the functional layer is a dielectric multilayer film as an example. However, the present invention can be applied to various functional layers other than the dielectric multilayer film. Is possible. Examples of the functional layer other than the dielectric multilayer film include an antistatic layer, an adhesion-imparting intermediate layer, a color material layer, and the like, and conventionally known knowledge is appropriately used for these specific configurations. Reference can be made.

(Use)
The thermal barrier film according to this embodiment can be applied to a wide range of fields. For example, it is attached to facilities exposed to sunlight for a long time, such as outdoor windows of buildings and automobile windows, and it is mainly used to improve weather resistance as a film for window pasting to provide a heat shielding function, a film for agricultural greenhouses, etc. Used for purposes.

[Adhesive layer]
Moreover, the heat shield film according to the present invention may have an adhesive layer. This pressure-sensitive adhesive layer is usually provided on the outermost surface of the base material of the heat-shielding film on the side opposite to the heat-shielding layer, and further known release paper may be further provided. The configuration of the adhesive layer is not particularly limited, and for example, any of a dry laminating agent, a wet laminating agent, an adhesive, a heat seal agent, a hot melt agent, and the like is used. As the adhesive, for example, a polyester resin, a urethane resin, a polyvinyl acetate resin, an acrylic resin, a nitrile rubber, or the like is used.

[Heat shield]
In particular, the heat-shielding film according to this embodiment is preferably used for a heat-shielding body that is a member bonded to a substrate such as glass or a glass-substituting resin directly or via an adhesive layer or the adhesive layer. it can.

Specific examples of the substrate include, for example, glass, polycarbonate resin, polysulfone resin, acrylic resin, polyolefin resin, polyether resin, polyester resin, polyamide resin, polysulfide resin, unsaturated polyester resin, epoxy resin, melamine resin, Examples thereof include phenol resin, diallyl phthalate resin, polyimide resin, urethane resin, polyvinyl acetate resin, polyvinyl alcohol resin, styrene resin, vinyl chloride resin, metal plate, ceramic and the like. The type of resin may be any of a thermoplastic resin, a thermosetting resin, and an ionizing radiation curable resin, and two or more of these may be used in combination. The substrate that can be used in the present invention can be produced by a known method such as extrusion molding, calendar molding, injection molding, hollow molding, compression molding and the like. The thickness of the substrate is not particularly limited, but is usually 0.1 mm to 5 cm. As the substrate, glass is particularly preferable from the viewpoint of practicality.

Here, the substrate may be a flat surface or a curved surface. Thermoforming for laminating with a substrate having a curved surface is generally performed on one surface of the substrate having a curved surface, with the heat-shielding layer of the heat-shielding film on the inside, that is, in the state facing the substrate toward the substrate, Deform along the shape of the substrate. After that, the heat shielding layer of the heat shielding film is bonded to the substrate on the opposite surface of the substrate having a curved surface in a state where the heat shielding layer is directed to the outside, that is, the substrate is directed to the opposite side of the substrate.

Thus, another embodiment of the present invention is a heat shield made by bonding a heat shield film to a substrate.

Examples of the adhesive forming the adhesive layer include an adhesive mainly composed of a photocurable or thermosetting resin. The adhesive preferably has durability against ultraviolet rays, and is preferably an acrylic adhesive or a silicone adhesive. Furthermore, an acrylic adhesive is preferable from the viewpoint of adhesive properties and cost. In particular, a solvent system is preferable in the acrylic pressure-sensitive adhesive because the peel strength can be easily controlled. When a solution polymerization polymer is used as the acrylic solvent-based pressure-sensitive adhesive, known monomers can be used as the monomer. Further, polyvinyl butyral resin or ethylene-vinyl acetate copolymer resin used as an intermediate layer of laminated glass may be used. Specifically, plastic polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., Mitsubishi Plastics Co., Ltd.), ethylene-vinyl acetate copolymer (manufactured by DuPont, Takeda Pharmaceutical Co., Ltd., duramin), modified ethylene-vinyl acetate Copolymers (Mersen G manufactured by Tosoh Corporation) and the like.

In addition, you may add and mix | blend an ultraviolet absorber, an antioxidant, an antistatic agent, a heat stabilizer, a lubricant, a filler, coloring, an adhesion regulator etc. suitably in an adhesion layer or an adhesion layer.

[Heat insulation performance]
Insulation performance and solar heat shielding performance of a heat shielding film or a heat shield are generally JIS R 3209: 1998 (multi-layer glass), JIS R 3106: 1998 (transmittance, reflectance, emissivity, solar radiation of plate glass). Heat acquisition rate test method), JIS R 3107: 1998 (calculation method of thermal resistance of plate glass and heat transmissivity in architecture).

The effect of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples. In the following examples, the operation was performed at room temperature (25 ° C.) unless otherwise specified. Unless otherwise specified, “%” and “part” mean “% by mass” and “part by mass”, respectively.

<< Production of thermal barrier film >>
<Preparation of coating solution>
The coating liquid used for preparation of the thermal-insulation film of an Example and a comparative example was prepared as follows.

(Preparation of thermal barrier coating liquid HC1)
Aronix M-309 (trimethylol prohan triacrylate, manufactured by Toagosei Co., Ltd.) 390 parts by mass, cesium doped tungsten oxide (CWO) dispersion (YMF-02A, total solid concentration 28 mass% (cesium) as composite tungsten oxide Doped tungsten oxide concentration 18.5% by mass), composition: Cs _0.33 WO ₃ , average primary particle size: 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 650 parts by mass, 2, 4, 6 as basic nitrogen-containing compounds -3 parts by mass of trimethylpyridine (manufactured by Kanto Chemical Co., Inc.) and 300 parts by mass of methyl ethyl ketone as a solvent were added. Further, 20 parts by mass of Irgacure 819 (manufactured by BASF Japan Ltd.) and 0.5 part by mass of a fluorosurfactant (phthalent 650A, active ingredient concentration 30%, manufactured by Neos Co., Ltd.) were added as polymerization initiators. A thermal layer coating solution HC1 was prepared.

(Preparation of thermal barrier coating liquid HC2)
In the preparation of the thermal barrier layer coating solution HC1, 390 parts by mass of Aronix M-309, 366 parts by mass of Aronix M-309 and Aronix M-5300 (ω-carboxy-polycaprolactone monoacrylate, manufactured by Toagosei Co., Ltd. ) A thermal barrier layer coating solution HC2 was prepared in the same manner as the thermal barrier layer coating solution HC1 except that the mixture was changed to a mixture with 24 parts by mass.

(Preparation of thermal barrier coating liquid HC3)
In the preparation of the heat shielding layer coating solution HC1, except that 2,4,6-trimethylpyridine was changed to triethylamine (manufactured by Kanto Chemical Co., Inc.), the heat shielding layer was the same as the heat shielding layer coating solution HC1. Coating solution HC3 was prepared.

(Preparation of coating solution HC4 for heat shield layer)
In the preparation of the heat shielding layer coating liquid HC1, the same procedure as in the heat shielding layer coating liquid HC1 was conducted except that 2,4,6-trimethylpyridine was changed to 2-butanone oxime (manufactured by Tokyo Chemical Industry Co., Ltd.). Then, a coating solution HC4 for a heat shielding layer was prepared.

(Preparation of thermal barrier coating liquid HC5)
In the preparation of the heat shielding layer coating liquid HC1, 2,4,6-trimethylpyridine was changed to 2,2,4,4-tetramethyl-3-pentanone imine (manufactured by Tokyo Chemical Industry Co., Ltd.). In the same manner as the heat shielding layer coating liquid HC1, a heat shielding layer coating liquid HC5 was prepared.

(Preparation of thermal barrier coating liquid HC6)
In the preparation of the heat shielding layer coating solution HC1, except that 2,4,6-trimethylpyridine was changed to cyclohexanone oxime (manufactured by Wako Pure Chemical Industries, Ltd.), the same as the heat shielding layer coating solution HC1, A coating solution HC6 for a heat shielding layer was prepared.

(Preparation of thermal barrier coating liquid HC7)
In the preparation of the thermal barrier layer coating solution HC6, Aronix M-309 was mixed with Aronix M-405 (a mixture of dipentaerythritol pentaacrylate: dipentaerythritol hexaacrylate = 10-20: 90-80, manufactured by Toagosei Co., Ltd.). The coating liquid HC7 for the thermal barrier layer was prepared in the same manner as the coating liquid HC6 for the thermal barrier layer, except that it was changed to).

(Preparation of thermal barrier coating liquid HC8)
In the preparation of the thermal barrier layer coating solution HC6, Aronix M-309 was mixed with Aronix M-404 (a mixture of dipentaerythritol pentaacrylate: dipentaerythritol hexaacrylate = 30-40: 70-60, manufactured by Toagosei Co., Ltd. The heat shielding layer coating solution HC8 was prepared in the same manner as the heat shielding layer coating solution HC6 except that the addition amount of cyclohexanone oxime was changed from 3 parts by mass to 0.3 parts by mass.

(Preparation of thermal barrier coating liquid HC9)
In the preparation of the heat shielding layer coating solution HC8, except that the amount of cyclohexanone oxime added was changed from 0.3 parts by mass to 0.6 parts by mass, the same as the heat shielding layer coating solution HC8, A coating solution HC9 was prepared.

(Preparation of thermal barrier coating liquid HC10)
In the preparation of the heat shielding layer coating solution HC8, except that the addition amount of cyclohexanone oxime was changed from 0.3 parts by mass to 3 parts by mass, the same as the heat shielding layer coating solution HC8, the coating for the heat shielding layer Liquid HC10 was prepared.

(Preparation of thermal barrier coating liquid HC11)
In the preparation of the thermal barrier layer coating liquid HC8, the thermal barrier layer coating liquid HC8 was used except that the amount of cyclohexanone oxime added was changed from 0.3 parts by mass to 6 parts by mass. Liquid HC11 was prepared.

(Preparation of thermal barrier coating liquid HC12)
In the preparation of the thermal barrier layer coating solution HC8, except that the amount of cyclohexanone oxime added was changed from 0.3 parts by mass to 31 parts by mass, the same procedure as for the thermal barrier layer coating solution HC8 was applied. Liquid HC12 was prepared.

(Preparation of thermal barrier coating liquid HC13)
In the preparation of the coating solution HC1 for the heat shielding layer, 390 parts by mass of Aronix M-309 was changed to a mixture of 293 parts by mass of Aronix M-309 and 97 parts by mass of Aronix M-5300. A thermal barrier layer coating solution HC13 was prepared in the same manner as the thermal barrier layer coating solution HC1, except that 6-trimethylpyridine was not added.

(Preparation of thermal barrier coating liquid HC14)
In the preparation of the coating solution HC1 for the thermal barrier layer, the thermal barrier was changed except that 390 parts by mass of Aronix M-309 was changed to a mixture of 293 parts by mass of Aronix M-309 and 97 parts by mass of Aronix M-5300. In the same manner as the layer coating solution HC1, a heat shielding layer coating solution HC14 was prepared.

(Preparation of thermal barrier coating liquid HC15)
In the preparation of the heat shielding layer coating solution HC14, a heat shielding layer coating solution HC15 was prepared in the same manner as the heat shielding layer coating solution HC14 except that 2,4,6-trimethylpyridine was changed to cyclohexanone oxime. did.

(Preparation of thermal barrier coating liquid HC16)
In the preparation of the thermal barrier coating solution HC15, a mixture of 293 parts by weight of Aronix M-309 and 97 parts by weight of Aronix M-5300 was mixed with Carboset 526 (poly (ethyl acrylate / methyl methacrylate / acrylic acid), Lubrizol Advanced Materials. Except for changing to 390 parts by mass), a thermal barrier layer coating solution HC16 was prepared in the same manner as the thermal barrier layer coating solution HC15.

(Preparation of coating solution for low refractive index layer)
380 parts by mass of colloidal silica (10% by mass, Snowtex (registered trademark) OXS, average particle size of primary particles 4-6 nm, manufactured by Nissan Chemical Industries, Ltd.), 50 parts by mass of boric acid aqueous solution (3% by mass) 300 parts by weight of polyvinyl alcohol (4% by weight, JP-45, degree of polymerization: 4500, degree of saponification: 88 mol%, manufactured by Nippon Acetate / Poval) 3 parts by weight of surfactant (5% by weight, Softazolin LSB-R (manufactured by Kawaken Fine Chemical Co., Ltd.) was added in this order at 45 ° C. The coating solution for low refractive index layer was prepared by finishing 1000 parts by mass with pure water.

(Preparation of coating solution for high refractive index layer)
(Preparation of silica-attached titanium dioxide sol)
After adding 2 parts by mass of pure water to 0.5 parts by mass of titanium dioxide sol (15.0% by mass, SRD-W, volume average particle size: 5 nm, rutile titanium dioxide particles, manufactured by Sakai Chemical Industry Co., Ltd.), 90 Heated to ° C. Next, 0.5 part by mass of an aqueous silicic acid solution (sodium silicate No. 4, manufactured by Nippon Chemical Industry Co., Ltd. diluted with pure water so that the SiO ₂ concentration becomes 0.5% by mass) was gradually added. Then, heat treatment was carried out at 175 ° C. for 18 hours in an autoclave, and after cooling, the solution was concentrated with an ultrafiltration membrane to obtain a titanium dioxide sol (“silica”) having a solid content concentration of 20% by mass and having SiO ₂ adhered to the surface. (Also referred to as “attached titanium dioxide sol”) (volume average particle size: 9 nm).

(Preparation of coating solution)
48 parts by mass of an aqueous citric acid solution (1.92% by mass) is added to 113 parts by mass of the silica-attached titanium dioxide sol thus obtained (solid content 20% by mass), and further ethylene-modified polyvinyl alcohol (8% by mass). , EXVAL RS-2117, ethylene modification degree 3.0 mol%, saponification degree: 97.5-99 mol%, polymerization degree 1700, manufactured by Kuraray Co., Ltd.) 113 parts by mass and stirred, and finally a surfactant (softazoline) A high refractive index layer coating solution was prepared by adding 0.4 parts by mass of a 5% by mass aqueous solution of LSB-R (manufactured by Kawaken Fine Chemical Co., Ltd.).

(Preparation of thermal barrier film sample 1)
On a substrate (50 μm thick polyethylene terephthalate film, Cosmo Shine A4300, manufactured by Toyobo Co., Ltd.), a thermal barrier coating solution HC1 was applied with a gravure coater under the condition that the dry film thickness was 5 μm, and 90 ° C. For 1 minute. Next, using an ultraviolet lamp, the coating film is cured by irradiating ultraviolet rays from the surface side far from the base material of the coating film under the conditions of an illuminance of 100 mW / cm ² and an irradiation amount of 0.5 J / cm ² , thereby shielding heat. A layer was formed, and a thermal barrier film sample 1 was produced.

(Preparation of thermal barrier film samples 2 to 16)
Thermal barrier film samples 2 to 16 were produced in the same manner as the thermal barrier film sample 1 except that the thermal barrier layer coating liquid HC1 was changed to the thermal barrier layer coating liquids HC2 to 16, respectively.

(Preparation of thermal barrier film sample 17)
A substrate (50 μm thick polyethylene terephthalate film, Cosmo Shine A4300) heated to 45 ° C. while keeping the coating solution for the low refractive index layer and the coating solution for the high refractive index layer at 45 ° C. using a slide hopper coating apparatus. , Manufactured by Toyobo Co., Ltd.), 11 layers were simultaneously applied (total film thickness: 1.5 μm). At this time, the lowermost layer and the uppermost layer were low refractive index layers, and other than that, the low refractive index layers and the high refractive index layers were alternately laminated. The coating amount was adjusted so that the film thickness during drying was 150 nm for each low refractive index layer and 120 nm for each high refractive index layer. Immediately after coating, 5 ° C. cold air was blown for 5 minutes, and then 80 ° C. hot air was blown and dried to produce a dielectric multilayer film consisting of 11 layers.

Next, on the opposite side of the substrate on which the dielectric multilayer film is formed, the thermal barrier layer coating solution HC10 is applied with a gravure coater under the condition that the dry film thickness is 5 μm, and dried at 90 ° C. for 1 minute. I let you. Next, using an ultraviolet lamp, the coating film is cured by irradiating ultraviolet rays from the surface side far from the base material of the coating film under the conditions of an illuminance of 100 mW / cm ² and an irradiation amount of 0.5 J / cm ² , thereby shielding heat A layer was formed, and a thermal barrier film sample 17 was produced.

Details of these thermal barrier film samples 1 to 17 are shown in Table 1.

Also, the composition of HC1 to HC15 is summarized in Table 1 below. In Table 1 below, “CWO” means cesium-doped tungsten oxide. In addition, since each solid component in the coating solution remains in the heat shielding layer as it is, the amount of each basic nitrogen-containing compound added to the coating solution is the content of the basic nitrogen-containing compound in the heat shielding layer (in terms of solid content). Correspond.

[Evaluation of thermal barrier film]
<Evaluation of weather resistance>
According to the following method, the weather resistance of the thermal barrier film was evaluated. The results are shown in Table 1 below.

Each of the heat shield film samples 1 to 17 produced above was affixed to glass, and using a super xenon weather meter (Suga Test Machine SX75), with a radiant intensity of 180 W / m ² and a rainfall of 18 minutes / 60 minutes. Irradiation was performed for 48 hours and 500 hours (weather resistance test).

The haze is measured using a haze meter (NDH2000 type, manufactured by Nippon Denshoku Industries Co., Ltd.), and the difference between the haze values before the weather test and 48 hours after the weather test (ΔHAZE (48h)) and before the weather test and 500 hours of the weather test. The difference (ΔHAZE (500 h)) of the later haze value was calculated. The calculation was performed using the average value of 10 heat shield film samples. It means that the smaller the value of ΔHAZE, the smaller the degree of haze rise and the better the weather resistance.

As shown from the results in Table 1 above, the heat shield films 1 to 12 and 17 of Examples 1 to 13 increased in haze over time as compared to the heat shield films 13 to 16 of Comparative Examples 1 to 4. Can be significantly suppressed.

<Production and evaluation of heat shield>
Heat shields 1 to 12 and 17 were produced using the above heat shield film samples 1 to 12 and 17. On the transparent acrylic resin plate having a thickness of 5 mm and 20 cm × 20 cm, the heat shielding film samples 1 to 12 and 17 were adhered with an acrylic adhesive to produce the heat shielding bodies 1 to 12 and 17, respectively.

The manufactured heat shields 1 to 12 and 17 were easily usable despite their large size, and excellent heat shielding performance could be confirmed. When the thermal barrier film sample 17 having a dielectric multilayer film was used, particularly excellent thermal barrier performance could be confirmed.

Furthermore, this application is based on Japanese Patent Application No. 2015-032276 filed on February 20, 2015, the disclosure of which is incorporated by reference in its entirety.

Claims (7)

1. A thermal barrier film having a thermal barrier layer on a substrate,
   The heat-shielding layer contains at least one of tungsten oxide and composite tungsten oxide, a polymer of a monomer component having an acid value of 20 or less containing a (meth) acrylate monomer, and a basic nitrogen-containing compound. Thermal film.
2. The heat shield film according to claim 1, wherein the basic nitrogen-containing compound is at least one compound selected from the group consisting of an amine compound, an oxime compound, and an imine compound.
3. The heat-shielding film according to claim 1 or 2, wherein the basic nitrogen-containing compound has a boiling point of 200 ° C or higher.
4. The thermal barrier film according to any one of claims 1 to 3, wherein the composite tungsten oxide is cesium-doped tungsten oxide.
5. The heat shielding film according to any one of claims 1 to 4, wherein the (meth) acrylate monomer is a polymerizable acrylate having a primary hydroxyl group.
6. The heat insulating film according to claim 5, wherein the polymerizable acrylate has a hydroxyl value of 40 or more.
7. The heat shield film according to any one of claims 1 to 6, wherein a content (in terms of solid content) of the basic nitrogen-containing compound is 0.1 to 1% by mass with respect to the heat shield layer. .