WO2016088851A1 - Thermal barrier film and manufacturing method for same, and thermal barrier using same - Google Patents

Abstract

　The present invention provides a means for a thermal barrier film having a hard coat layer comprising tungsten oxide, whereby the adhesion of the hard coat layer is improved and the discoloration of the hard coat layer can be prevented.　The present invention pertains to a thermal barrier film comprising a substrate and a hard coat layer which is disposed on at least one surface of the substrate, is formed from the cured product of a hard coat layer coating solution, and includes (a)-(c): (a) tungsten oxide; (b) a (meth)acrylate compound essentially comprising a (meth)acrylate compound having a primary hydroxyl group; and (c) a metal salt,

Description

Heat shield film, method for producing the same, and heat shield using the same

The present invention relates to a heat shield film, a method for producing the same, and a heat shield using the same. More specifically, the present invention relates to a technique for improving adhesion of a hard coat layer and preventing discoloration of the hard coat layer in a thermal barrier film having a hard coat layer containing tungsten oxide. Furthermore, the present invention relates to a heat shield including such a heat shield film.

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). .

Since the heat shielding film is used by being attached to a window glass of a building or a vehicle, in addition to transparency and heat shielding properties, scratch resistance is required so as not to be damaged at the time of bonding or cleaning. Therefore, generally, a hard coat layer for the purpose of surface protection is formed on the film surface.

As such a heat shielding film, for example, a hard coat layer forming material containing a heat ray shielding metal oxide which is an infrared absorber and a specific active energy ray curable compound on one surface of a base film. There has been proposed a near-infrared shielding film having a hard coat layer formed from the above and having an adhesive layer on the other surface.

Further, it is known that a heat shielding film using tungsten oxide as a heat ray shielding metal oxide exhibits excellent heat shielding properties. However, the thermal barrier film using the tungsten oxide particles is likely to be discolored in an environment with a lot of moisture, and there remains a problem in terms of weather resistance.

In order to solve such problems, the infrared shielding film having a layer formed from a dispersion of infrared shielding material fine particles containing tungsten oxide and a metal salt on the substrate can reduce the thermal insulation characteristics over time. A technique for suppressing this is disclosed (for example, see Japanese Patent Application Laid-Open No. 2009-197146).

However, in the film disclosed in Japanese Patent Application Laid-Open No. 2009-197146, the adhesion between the layer having the tungsten oxide and the base material is low, and there is a problem that the layer having the tungsten oxide is peeled off. Improvement was desired. Moreover, the effect which prevents the deterioration (discoloration) with time of the heat-shielding property of the heat-shielding film is not sufficient, and further improvement has been desired.

Accordingly, an object of the present invention is to provide means for improving the adhesion of the hard coat layer and preventing discoloration of the hard coat layer in the heat-shielding film having the hard coat layer containing tungsten oxide. Yes.

The above-mentioned problem of the present invention is solved by the following means.

A base material and the following (a) to (c) disposed on at least one surface of the base material:
(A) Tungsten oxide (b) A (meth) acrylate-based compound that essentially contains a (meth) acrylate-based compound having a primary hydroxyl group, and (c) a hardened layer coating solution that contains a metal salt. A thermal barrier film having a hard coat layer.

Hereinafter, embodiments of the present invention will be described. However, this invention is not restrict | limited only to the following forms.

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”.

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

<Heat shield film>
One aspect of the present invention is a substrate and the following (a) to (c) disposed on at least one surface of the substrate:
(A) Tungsten oxide (b) A (meth) acrylate-based compound that essentially contains a (meth) acrylate-based compound having a primary hydroxyl group, and (c) a hardened layer coating solution that contains a metal salt. And a hard coat layer. According to the film of one embodiment of the present invention having such a configuration, the adhesion of the hard coat layer can be improved and the discoloration of the hard coat layer can be prevented.

The inventors of the present invention have made extensive studies in order to achieve both adhesion of the hard coat layer and prevention of discoloration (weather resistance) in the heat shield film having the hard coat layer containing tungsten oxide, which is a heat ray shielding metal oxide. Repeated. Then, by using a coating liquid for hard coat layer containing a (meth) acrylate compound having a primary hydroxyl group and containing a (meth) acrylate compound and a metal salt, adhesion and discoloration of the hard coat layer are used. The inventor found the surprising fact that both prevention (weather resistance) can be achieved and completed the present invention.

As for the cause of the low adhesion of the hard coat layer formed from the coating liquid for hard coat layer containing tungsten oxide and metal salt, the present inventors have worked hard as the metal salt acts as a radical scavenger. It is considered that this is a result of inhibiting the curing of the ultraviolet curable composition forming the coating layer.

Here, as a mechanism by which the adhesion is improved by the hard coat layer according to one embodiment of the present invention, the present inventors have reported that (meth) acrylate compounds having a primary hydroxyl group are (meth) acrylate by hydrogen bonding. In order to keep the distance between the reactive groups of the system compound short, even if a metal salt is contained, the curing reaction of the (meth) acrylate compound is hardly inhibited and the crosslinking density can be increased. Yes.

In addition, as a mechanism for preventing discoloration by the hard coat layer according to one embodiment of the present invention, the present inventors have described that a (meth) acrylate compound having a primary hydroxyl group or a hydroxyl group of a cured product thereof is a tungsten oxide. I guess it will adsorb. Here, the metal salt has a function of suppressing deterioration over time of the heat shielding property, and the function of such a metal salt is that the metal salt captures moisture and radicals in the hard coat layer. It is thought to be caused. The reason why the discoloration is prevented is that tungsten oxide, metal salt, and a (meth) acrylate compound having a primary hydroxyl group or a cured product of a (meth) acrylate compound having a primary hydroxyl group are close to each other. From this, it is presumed that the effect of the metal salt capturing the moisture and radicals that cause the deterioration of the tungsten oxide is synergistically enhanced. Among the (meth) acrylate compounds having a hydroxyl group, the (meth) acrylate compound having a primary hydroxyl group is more sterically than the (meth) acrylate compound having a secondary hydroxyl group and a tertiary hydroxyl group. Therefore, it is presumed to exhibit excellent effects because it is easily adsorbed to tungsten oxide (component (a)).

The above mechanism is based on speculation, and its correctness does not affect the technical scope according to one embodiment of the present invention. In addition, it is considered that the above mechanism can be applied to a case where another optional layer is provided between the hard coat layer and the base material.

[Base material]
The base material has a function of supporting a hard coat layer and other arbitrarily provided layers (for example, a functional layer typified by a dielectric multilayer film).

As the substrate, various resin films can be used, and the substrate is preferably transparent. 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, dimensional stability, the polyester forming the film includes dicarboxylic acid components such as terephthalic acid and 2,6-naphthalenedicarboxylic acid, ethylene glycol, and 1, A polyester having a film-forming property, having a diol component such as 4-cyclohexanedimethanol as a main constituent component is preferable. Among them, as the polyester forming the film, polyesters mainly composed of polyethylene terephthalate and polyethylene naphthalate, copolymer polyesters composed of terephthalic acid, 2,6-naphthalenedicarboxylic acid and ethylene glycol, and these A polyester having a mixture of two or more kinds of polyester as a main constituent is more preferable. More preferably, a polyethylene terephthalate film is used as the substrate.

Further, as the base material of the heat-shielding film according to one embodiment of the present invention, in addition to those mentioned above, a dielectric multilayer film described later which has 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 coextrusion method or the co-flow method are mentioned.

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. 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 base material is 200 μm or less, for example, when the thermal barrier film is bonded to the base, the followability to the curved base is improved and wrinkles are less likely to occur. From the same viewpoint, the thickness of the substrate is more preferably 30 to 150 μm, further preferably 35 to 125 μm, particularly preferably 40 to 80 μm, and most preferably 40 to 60 μm. preferable.

The substrate is particularly 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.

[Hard coat layer]
In one embodiment of the present invention, the “hard coat layer” is a layer having a pencil hardness of H or higher according to JIS K 5600-5-4: 1999, preferably a layer of 2H or higher. The hardness of the hard coat layer is preferably in terms of scratch resistance as long as the layer is not damaged or peeled off when an external stress such as bending is applied.

The hard coat layer according to one embodiment of the present invention includes (a) a tungsten oxide, (b) a (meth) acrylate compound having a primary hydroxyl group as an essential component, and (c) a metal. It is preferably formed by applying a coating liquid for hard coat layer containing salt on a substrate and then irradiating with ultraviolet rays to cure the coating film. That is, the hard coat layer according to one embodiment of the present invention includes the following (a) to (c):
(A) Tungsten oxide (b) A (meth) acrylate-based compound that essentially contains a (meth) acrylate-based compound having a primary hydroxyl group, and (c) a hardened layer coating solution that contains a metal salt. .

Here, (a) tungsten oxide is a kind of heat ray shielding metal oxide having infrared absorptivity as will be described later (also referred to as [infrared shielding metal oxide]). A hard coat layer made of a cured product of the hard coat layer coating solution has a heat shielding function for shielding the transmission of heat rays (infrared rays).

The thickness of the hard coat layer is not particularly limited, but is preferably 1 to 10 μm. By setting the thickness to 1 μm or more, the hardness of the hard coat layer can be maintained. On the other hand, by setting the thickness to 10 μm or less, cracking of the hard coat layer due to stress can be prevented. From the same viewpoint, the thickness of the hard coat layer is more preferably 1.5 to 8 μm, and further preferably 2 to 7 μm.

(Method for forming hard coat layer)
First, each component contained in the hard coat layer coating solution will be described.

(A) Tungsten oxide Tungsten oxide is one type of heat ray shielding metal oxide having infrared absorptivity.

The hard coat layer coating liquid according to one embodiment of the present invention essentially includes tungsten oxide (hereinafter also referred to as component (a)), which is a heat ray shielding metal compound.

As the tungsten oxide, those represented by the general formula: W _y O _z and the same as those described in JP2013-64042A and JP2010-215451A 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.

As tungsten oxide, composite tungsten oxide can be used. 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 from the viewpoint of stability. The same ones described in 2010-215451 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 excluding beryllium and magnesium, 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 . As the tungsten oxide, it is particularly preferable to use Cs _0.33 WO ₃ which is a cesium-containing composite tungsten oxide.

Thus, another embodiment of the present invention is a thermal barrier film in which (a) tungsten oxide is a cesium-containing composite tungsten oxide.

The shape of the (composite) tungsten oxide 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, preferably It is particulate. Further, the size of tungsten oxide or the like is not particularly limited. However, when tungsten oxide or the like is in the form of particles, the average particle diameter (average primary particle diameter, diameter) of the particles such as tungsten oxide can ensure a heat ray absorption effect while suppressing reflection of visible light, Further, since haze deterioration due to scattering does not occur and transparency can be secured, the thickness is preferably 5 to 150 nm, more preferably 5 to 100 nm, still more preferably 10 to 80 nm, and more preferably 30 to 60 nm. Particularly preferred is 40 to 50 nm. The average particle size is determined by observing the particle itself 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). Here, the particle diameter of each particle is represented by a diameter assuming a circle equal to the projected area.

Further, these specific trade names are not particularly limited, and examples thereof include CWO dispersion liquid (YMF-02A, manufactured by Sumitomo Metal Mining Co., Ltd.) as a cesium doped tungsten oxide system.

The content of tungsten oxide in the coating liquid for hard coat layer is not particularly limited, but from the viewpoint of adjusting physical properties such as hardness and film elastic modulus and optical properties such as transmittance to desired values, the hard coat layer It is preferably 10 to 80% by mass, more preferably 20 to 60% by mass, and still more preferably 20 to 40% by mass, based on the total mass of the components excluding the solvent of the coating liquid for coating. It is particularly preferably 20 to 30% by mass.

(B) A (meth) acrylate compound that essentially contains a (meth) acrylate compound having a primary hydroxyl group. A (meth) acrylate compound that is a material for a coating liquid for a hard coat layer according to an embodiment of the present invention. Is a polymerizable compound that is cured by ultraviolet rays.

In the present specification, the term “(meth) acrylate-based compound” is a concept that may include not only a monomer but also an oligomer or a prepolymer that can be cured by ultraviolet irradiation.

The coating liquid for hard coat layers according to an embodiment of the present invention includes (b) a (meth) acrylate compound (hereinafter referred to as component (b)) that essentially contains a (meth) acrylate compound having a primary hydroxyl group. ) Is essential.

A hard coat layer using only a (meth) acrylate compound having no primary hydroxyl group has low adhesion and a large color change. Such low adhesion is considered to be caused by the fact that the curing reaction of the (meth) acrylate compound is inhibited by the metal salt as described above. In addition, as described above, the cured product of a tungsten oxide, a metal salt, and a (meth) acrylate compound having a primary hydroxyl group or a (meth) acrylate compound having a primary hydroxyl group also has a large change in color. Is not present in the vicinity, and it is considered that the effect of synergistically enhancing the moisture and radical scavenging effect in the layer cannot be obtained. As the (meth) acrylate compound used in this embodiment, the above problem is solved by essentially including a (meth) acrylate compound having a primary hydroxyl group.

In the present specification, “primary hydroxyl group” means a hydroxyl group in which its own oxygen atom is bonded to a primary carbon. Examples of the structure having primary carbon include a methylene group.

The (meth) acrylate compound having a primary hydroxyl group is not particularly limited. For example, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3 -Hydroxypropane-1,2-diyl di (meth) acrylate, glycerol mono (meth) acrylate, diglycerol mono (meth) acrylate, diglycerol tri (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol mono ( (Meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate Dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, sorbitol di (meth) acrylate, sorbitol tri (meth) acrylate, sorbitol tetra (meth) acrylate, sorbitol penta (meth) acrylate, sorbitol mono (meth) ) Acrylate diglycerin di (meth) acrylate, isocyanuric acid EO-modified diacrylate and the like.

The number of primary hydroxyl groups in the molecule of the (meth) acrylate compound having a primary hydroxyl group is preferably 1 to 4 (Example: 1). 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.

As the (meth) acrylate compound having a primary hydroxyl group, pentaerythritol tri (meth) acrylate and dipentaerythritol penta (meth) acrylate are preferable from the viewpoint of adhesion, and pentaerythritol triacrylate and dipentaerythritol penta Acrylates are more preferred, and pentaerythritol triacrylate is more preferred.

These (meth) acrylate compounds having a primary hydroxyl group can be used singly or in combination of two or more.

The ratio of the (meth) acrylate compound having a primary hydroxyl group to the total mass of the (meth) acrylate compound (component (b)) is preferably 10 to 100% by mass. It is preferable from an adhesive viewpoint that it is 10 mass% or more. From the same viewpoint, the content is more preferably 30 to 100% by mass, and further preferably 50 to 100% by mass.

As the (meth) acrylate compound other than the (meth) acrylate compound having a primary hydroxyl group contained in the (meth) acrylate compound (component (b)), particularly if it can be cured by ultraviolet irradiation. Not limited. Examples of (meth) acrylate compounds other than (meth) acrylate compounds having a primary hydroxyl group include (meth) acrylate compounds, urethane (meth) acrylate compounds, epoxy (meth) acrylate compounds, polyols (meth) ) Acrylate compounds, polyester (meth) acrylate compounds, silicone (meth) acrylate compounds, and the like can be used.

Specifically, for example, ethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate 1,10-decanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (Meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, propoxylated ethoxylated bisphenol A di ( (Meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, 9,9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene, propoxylated bisphenol A di (meth) acrylate, tricyclodecandi Methanol di (meth) acrylate, ethoxylated isocyanuric acid tri (meth) acrylate, ε-caprolactone modified tris- (2- (meth) acryloxyethyl) isocyanurate, ethoxylated pentaerythritol tetraacrylate, trimethylolpropane tri (meth) Examples include acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and silicone di (meth) acrylate. For example, commercially available products such as EBECRYL (registered trademark) 350 manufactured by Daicel Ornex Co., Ltd., and X-22-2445 and X-22-1602 manufactured by Shin-Etsu Chemical Co., Ltd. can also be used as appropriate.

Here, as the (meth) acrylate compound (component (b)), for example, commercially available products such as Aronix (registered trademark) M-305, M-402, M-405 manufactured by Toagosei Co., Ltd. may be used as appropriate. it can. These details will be described in the examples described later.

The hydroxyl value of the (meth) acrylate compound (component (b)) is preferably 10 or more. When the hydroxyl value is 10 or more, the adhesion improving effect of the hard coat layer and the discoloration preventing effect of the hard coat layer are further enhanced. The reason for this is that the distance between the reactive groups of the (meth) acrylate compound is kept short by hydrogen bonding, so that even if a metal salt is contained, the curing reaction of the (meth) acrylate compound is hardly inhibited, and the crosslinking density It is thought that the effect of raising the value can be exhibited more. The hydroxyl value of the (meth) acrylate compound (component (b)) is more preferably 40 or more. When the hydroxyl value is 40 or more, the effect of preventing discoloration of the hard coat layer can be further improved. Furthermore, the hydroxyl value of the (meth) acrylate compound (component (b)) is more preferably 80 or more. When the hydroxyl value is 80 or more, the adhesion improving effect of the hard coat layer is further enhanced.

The hydroxyl value of the (meth) acrylate compound (component (b)) is preferably 200 or less. When the hydroxyl value is 200 or less, the effect of suppressing curling caused by moisture absorption is further increased.

Thus, another preferred embodiment of the present invention is (b) a thermal barrier film containing a (meth) acrylate compound having a primary hydroxyl group and having a hydroxyl value of 10 or more of the (meth) acrylate compound. is there.

Further, another preferred embodiment of the present invention is (b) a thermal barrier film containing a (meth) acrylate compound having a primary hydroxyl group and having a hydroxyl value of 40 or more. is there.

The hydroxyl value of the (meth) acrylate compound (component (b)) is the kind of (meth) acrylate compound having a primary hydroxyl group, and (meth) acrylate other than the (meth) acrylate compound having a primary hydroxyl group. It can adjust with the kind of system compound, and these content.

The hydroxyl value of the (meth) acrylate compound (component (b)) can be measured according to JIS K 0070 (1992). Specifically, this hydroxyl value is defined as the number of mg of potassium hydroxide required to neutralize acetic acid bonded to a hydroxyl group when 1 g of a sample is acetylated. Specifically, sample Xg (about 1 g) is precisely weighed in a flask, and 20 mL of an acetylating reagent (a solution obtained by adding pyridine to 20 mL of acetic anhydride to 400 mL) is accurately added thereto. Attach an air cooling tube to the mouth of the flask and heat in a glycerin bath at 95-100 ° 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.

Hydroxyl value = {(BC) × f × 28.05 / X} + D
(In the formula, B is the amount of 0.5 mol / L potassium hydroxide ethanol solution (mL) used for the blank test, and C is the amount of 0.5 mol / L potassium hydroxide ethanol solution used for titration (mL). , F is a factor of 0.5 mol / L potassium hydroxide ethanol solution, D is an acid value, and 28.05 is 1/2 of 1 mol amount of potassium hydroxide 56.11).

The content of the (meth) acrylate compound (component (b)) in the hard coat layer coating solution is not particularly limited, but from the viewpoint of adjusting the hardness and film elastic modulus to desired values, the hard coat layer coating solution. Is preferably 20 to 90% by mass, more preferably 20 to 80% by mass, still more preferably 40 to 80% by mass, and more preferably 50 to It is particularly preferably 70% by mass, and most preferably 60 to 70% by mass.

(C) Metal salt The coating liquid for hard coat layers according to one embodiment of the present invention essentially contains a metal salt (hereinafter also referred to as component (c)). Here, the metal salt has a function of suppressing deterioration over time of the heat-shielding property, and this function is considered to be caused by the metal salt capturing moisture and radicals in the hard coat layer.

The metal constituting the metal salt is not particularly limited. For example, Cs, Sr, Ba, Ti, Zr, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, In, Sn, Mg, Ni, Sc, Y, V, Al, Pb, Bi, and alkali metals and alkaline earth metals other than those listed above Is mentioned.

Among these, Zn, Mg, Ni, In, and Sn are preferable from the viewpoint of preventing discoloration, and Zn, Mg, and Ni are more preferable.

The metal salt may be an organic acid salt or an inorganic acid salt. Among these, from the viewpoint of the effect of preventing discoloration, it may be a carboxylate, carbonyl complex, carbonate, phosphate, perchlorate, hypochlorite, chlorite, chlorate, or hydrochloride. Preferably, perchlorate and carboxylate are more preferable, and carboxylate is more preferable.

Thus, another preferred embodiment of the present invention is (c) a thermal barrier film in which the metal salt is a carboxylate.

The carboxylic acid constituting the carboxylate is not particularly limited, but for example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, 2-ethylhexanoic acid, naphthenic acid, enanthic acid, caprylic acid, pelargon Acid, capric acid, lauric acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, docosahexaenoic acid, eicosapentanoic acid, oxalic acid, malonic acid, succinic acid, Benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, melittic acid, cinnamic acid, pyruvic acid, lactic acid, malic acid, citric acid, maleic acid, aconitic acid, glutaric acid, adipic acid, amino acids, etc. Can be mentioned. Examples of the β-diketone constituting the carbonyl complex salt include acetylacetone, benzoylacetone, benzoyltrifluoroacetone, hexafluoroacetylacetone, 2-thenoyltrifluoroacetone and the like.

Among these, acetic acid, 2-ethylhexanoic acid, and stearic acid are preferable from the viewpoint of discoloration prevention effect. Among these, 2-ethylhexanoic acid is more preferable from the viewpoint of particularly good compatibility with the hard coat layer and excellent haze suppression effect.

Specific metal salts are not particularly limited, and examples thereof include Ni perchlorate, Mg stearate, Zn acetate, and bis (2-ethylhexanoic acid) Zn.

The content of the metal salt is not particularly limited, but is preferably 0.005 to 10% by mass with respect to the total mass of the components excluding the solvent of the hard coat layer coating solution. When the content of the metal salt is 0.005% by mass or more, the discoloration preventing effect of the hard coat layer is further increased. The reason for this is considered to be that the metal salt has a good effect of capturing moisture and radicals in the hard coat layer. Moreover, the adhesive improvement effect of a hard-coat layer increases more as content of a metal salt is 10 mass% or less. The reason for this is considered to be that even when the addition amount of the metal salt is contained, the curing reaction of the (meth) acrylate compound is hardly inhibited, and the effect of increasing the crosslinking density can be exhibited more. From the same viewpoint, the content of the metal salt is more preferably 0.01 to 1.0% by mass, further preferably 0.05 to 1.1% by mass, and 0.05 to 1.% by mass. It is particularly preferable that the content be 0% by mass.

The hard coat layer coating liquid according to one embodiment of the present invention may contain a solvent in addition to the above essential components. The solvent is not particularly limited. For example, water, hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), esters ( (Methyl acetate, ethyl acetate, methyl lactate), glycol ethers, other organic solvents and the like can be appropriately selected or used by mixing them.

The content of the solvent in the coating solution for the hard coat layer is not particularly limited, but is preferably about 10 to 80% by mass, more preferably 20 to 80% by mass with respect to the total mass of the coating solution. It is more preferably 20 to 60% by mass, particularly preferably 40 to 60% by mass, and most preferably 50 to 60% by mass.

The coating liquid for hard coat 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. Acyl phosphine oxides are not particularly limited, and examples thereof include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenyl ethoxyphosphine 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 thioxanthone is 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.

Among these, acylphosphine oxides are preferable, and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide is more preferable.

Also, for example, commercially available products such as Irgacure (registered trademark) 184, 651, 1173, 819, LUCIRIN (registered trademark) TPO manufactured by BASF Japan Ltd. can be 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 with respect to 100 parts by mass of the polymerizable component including the (meth) acrylate compound (component (b)). It is more preferably from 15 to 15 parts by mass, further preferably from 1 to 10 parts by mass, and particularly preferably from 2 to 8 parts by mass.

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 content of the surfactant is preferably 0.01% by mass to 1% by mass, and preferably 0.01% by mass to 0.5% by mass with respect to the total mass of the components excluding the solvent of the hard coat layer coating solution. More preferred is 0.01 to 0.2% by mass.

The thermal barrier film according to an aspect of the present invention is
On at least one side of the substrate,
The following (a) to (c);
(A) Tungsten oxide (b) A (meth) acrylate compound having a primary hydroxyl group and a (meth) acrylate compound (c) A hard coat layer coating solution containing a metal salt is formed on the substrate. It is preferable to manufacture by the manufacturing method of a thermal barrier film including the process of irradiating an ultraviolet-ray after application | coating and hardening a coating film.

The film produced by such a production method is
The substrate has a hard coat layer disposed on at least one surface of the substrate, and the hard coat layer is coated with a coating liquid by irradiating ultraviolet rays after coating the hard coat layer coating liquid on the substrate. The hard coat layer coating solution, which is formed by curing, has the following (a) to (c):
(A) Tungsten oxide (b) A (meth) acrylate compound containing a (meth) acrylate compound having a primary hydroxyl group, (c) A thermal barrier film containing a metal salt,
The following (a) to (c) disposed on the base material and at least one surface of the base material:
(A) Tungsten oxide (b) A (meth) acrylate-based compound that essentially contains a (meth) acrylate-based compound having a primary hydroxyl group, and (c) a hardened layer coating solution that contains a metal salt. And a hard coat layer.

The coating liquid for hard coat layer is prepared 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 hard-coat 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 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 coating are not particularly limited, but for example, the drying temperature is preferably 70 to 110 ° C., and the drying time is preferably 30 seconds to 5 minutes.

Thereafter, the coating film obtained by applying the coating liquid for hard coat layer on the substrate is irradiated with ultraviolet rays from the side of the coating film that is 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-shielding film according to one embodiment of the present invention may have a functional layer in addition to the base material and the hard coat 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 a reflective layer).

(Dielectric multilayer film)
Another preferable 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 laminated.

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). In the same manner, 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), and particularly preferably 10 to 30 (that is, 5 to 15 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 reflectance (infrared shielding ratio) of 90% or more, if the difference in refractive index is smaller than 0.1, a laminate exceeding 100 layers is required, and not only productivity is lowered. , 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 model (manufactured by Hitachi, Ltd.) as a spectrophotometer, the surface opposite to the measurement surface (back surface) of each sample is roughened and then light-absorbed with a black spray. To prevent reflection of light on the back surface, measure the reflectance in the visible light region (400 nm to 700 nm) at 25 points under the condition of regular reflection at 5 degrees, obtain an average value, and calculate the average refractive index from the measurement result Ask for.

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 utilizing this optical path difference, reflection can be controlled. By utilizing 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 preferably 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), polyethylene terephthalate copolymer (coPET), poly (methyl methacrylate) (PMMA), and poly (methyl methacrylate). Copolymer (coPMMA), cyclohexanedimethanol (PETG), copolymer of cyclohexanedimethanol (coPETG), polyethylene naphthalate (PEN), copolymer of polyethylene naphthalate (coPEN), polyethylene naphthalate, copolymer of polyethylene naphthalate, poly (methyl methacrylate) ), And copolymers of poly (methyl methacrylate) and the like, but are not limited thereto. 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 above polymer by a continuous flat film production 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-acrylate resins such as styrene-α-methylstyrene-acrylic acid copolymer, or styrene-α -methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-sodium styrenesulfonate copolymer, styrene- 2-hydroxyethyl acrylate Copolymer, styrene-2-hydroxyethylacrylate-potassium styrenesulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinylnaphthalene-acrylic acid copolymer, vinylnaphthalene- Mention may be made of maleic 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. It can be used similarly. Specifically, the polyvinyl alcohols include 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, more preferably 1,500 to 5,000. The degree of saponification is preferably 70 to 100 mol%, more preferably 80 to 99.9 mol%, and still more preferably 85 to 99.9 mol%.

The modified polyvinyl alcohol is not particularly limited, and examples thereof include cation modified polyvinyl alcohol, anion modified polyvinyl alcohol, nonionic 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 a modified polyvinyl alcohol having a water-soluble group as described in JP-A-7-285265.

Nonionic modified polyvinyl alcohols include, for example, polyvinyl alcohol derivatives obtained by adding a polyalkylene oxide group 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 a primary to tertiary amino group or a quaternary ammonium group as described in JP-A No. 61-10483. Examples thereof include polyvinyl alcohol. Such cation-modified polyvinyl alcohol can be obtained, for example, 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, Japanese Patent Application No. 2013-206913, and the like can be used. .

Although these polyvinyl alcohols are not particularly limited, for example, Exebar (registered trademark) (trade name: manufactured by Kuraray Co., Ltd.) which is an ethylene-modified polyvinyl alcohol or Nichigo G polymer (butenediol / vinyl alcohol copolymer resin) ( (Registered trademark) (trade name: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), polyvinyl acetal resin obtained by reacting polyvinyl alcohol with an aldehyde (for example, “ESREC (registered trademark)” manufactured by Sekisui Chemical Co., Ltd.), silanol group Silanol-modified polyvinyl alcohol (for example, “R-1130” manufactured by Kuraray Co., Ltd.), modified polyvinyl alcohol-based resin having an acetoacetyl group in the molecule (for example, “Gosefimer (registered trademark)” manufactured by Nippon Synthetic Chemical Industry Co., Ltd. Z / WR series 'S "), and the like.

Among these polyvinyl alcohols, it is preferable to use polyvinyl alcohol or ethylene-modified polyvinyl alcohol.

In addition, the above-mentioned polyvinyl alcohols may be used alone or in combination of two or more. In addition, as the polyvinyl alcohol, a synthetic product or a commercially available product may be used.

The weight average molecular weight of the polyvinyl alcohols is preferably 1,000 to 1,000,000, more preferably 3,000 to 250,000, and still more preferably 60,000 to 250,000. 60,000 to 200,000 is particularly preferable. In this specification, the value measured by a static light scattering method, gel permeation chromatography (GPC), TOF MASS method or the like is adopted as the value of “weight 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 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. From the same viewpoint, the content of the water-soluble polymer is more preferably 10 to 70% by mass, further preferably 15 to 50% by mass, and particularly preferably 20 to 30% by mass. preferable. 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 and 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》
Although it does not restrict | limit especially as a metal oxide particle used for a high-refractive-index layer, For example, a titanium oxide, a zirconium oxide, a zinc oxide, an alumina, a colloidal alumina, a lead titanate, a lead titan, a yellow lead, zinc yellow, a 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 double oxides composed of these oxides, such as lithium niobate, potassium niobate, lithium tantalate, and aluminum / magnesium oxide (MgAl ₂ O ₄ ).

Also, rare earth oxides can be used as the metal oxide particles. Specific examples of rare earth oxides include scandium oxide, yttrium oxide, lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, Examples include thulium oxide, ytterbium oxide, and lutetium oxide.

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

The metal oxide particles used in the high refractive index layer preferably have a volume average particle size of 100 nm or less, more preferably 50 nm or less, further preferably 30 nm or less, and preferably 1 to 30 nm. Even more preferably, it is 1 to 20 nm, particularly preferably 1 to 15 nm. 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.

When titanium oxide particles are used as the metal oxide particles used in the high refractive index layer, the titanium oxide particles should be prepared by modifying the surface of the titanium oxide sol so that it can be dispersed in water or an organic solvent. preferable. 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 63-63. Reference can be made to matters described in Japanese Patent No. 17221.
The average particle diameter of titanium oxide is preferably 100 nm or less, more preferably 50 nm or less, and further preferably 1 to 30 nm from the viewpoint of a low haze value and excellent visible light transmittance. It is particularly preferred that 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 titanium oxide particles as a core is covered with a shell made of silicon-containing hydrated oxide. 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 preferably 3 to 30% 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. From the same viewpoint, the coating amount of the silicon-containing hydrated oxide is more preferably 3 to 10% by mass, and further preferably 3 to 8% by mass.

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.

From the viewpoint of infrared shielding and from the viewpoint of reducing color unevenness when a film is applied to curved glass, the content of metal oxide particles in the high refractive index layer is based on 100% by mass of the solid content of the high refractive index layer. It is preferably 20 to 80% by mass, more preferably 30 to 75% by mass, still more preferably 40 to 70% by mass, and particularly preferably 60 to 70% by mass.

<< Metal oxide particles in the low refractive index layer >>
The average primary particle size of the metal oxide particles used in the low refractive index layer is preferably 100 nm or less.

As the metal oxide particles mainly used for 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, it is more preferably 50 to 75% by mass, and particularly preferably 65 to 75% by mass.

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 Snowtex series (Snowtex (registered trademark) OS, OXS, S, OS, 20, 30, 40, O, N, C, etc.) sold by Nissan Chemical Industries, Ltd.

(Other additives)
In addition to the above, each refractive index layer is composed of, 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 may be contained such Tsu bets agent. 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 vinyl Examples of such compounds include 1,3,5-trisacryloyl-hexahydro-s-triazine, bisvinylsulfonylmethyl ether, aluminum alum and borax. The content of the curing agent in the refractive index layer is preferably 1 to 10% by mass, and more preferably 1 to 5% 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, and more preferably 0.01 to 1% 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 a polymer, gold oxide particles, other additives added as necessary, and a solvent are added. The method of stirring and mixing is mentioned. 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 preparing the coating solution for forming the high refractive index layer and the coating solution for forming the low refractive index layer, they may be prepared while appropriately heating.

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, a method for forming a dielectric multilayer film by coating on a substrate using the coating solution for a high refractive index layer and the coating solution for a low refractive index layer prepared as described above and drying it will be described.

The coating method is not particularly limited, and may be any one of a sequential coating method and a simultaneous multilayer coating, but is preferably a simultaneous multilayer coating from the viewpoint of productivity and the like.

As a 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 30 to 45 ° 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.

The coating and drying method is not particularly limited, but a specific example of forming the reflective film by the sequential coating method is a low refractive index layer heated to 25 to 60 ° C., preferably 30 to 45 ° C. One of the coating liquid for coating and the coating liquid for the high refractive index layer is coated on a substrate and dried to form a layer, and then the other coating liquid is coated on 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 at a wet bulb temperature of 5 to 50 ° C. and a film surface temperature of 5 to 100 ° C. (preferably 10 to 50 ° C.). For example, hot air of 40 to 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 25 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 can be dried by blowing warm air of 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 time (setting time) from the time of application until the setting is completed by applying cold air is preferably within 6 minutes, more preferably within 5 minutes, and even more preferably within 2 minutes. . Further, the lower limit time is not particularly limited, but it is preferably 10 seconds or more, and more preferably 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.

More specifically, in the setting step, the temperature of the cold air used is preferably 0 to 25 ° C., more preferably 5 to 10 ° C. The time for which the coating film is exposed to cold air is preferably 10 to 360 seconds, more preferably 10 to 300 seconds, and further preferably 10 to 120 seconds, although it depends on the transport speed of the coating film.

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, for example, an antistatic layer, an adhesion-imparting intermediate layer, a color material layer, and the like. Reference can be made.

[Adhesive layer]
Moreover, the heat shield film according to one embodiment of 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 hard coat 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 pressure-sensitive adhesive, for example, polyester resin, urethane resin, polyvinyl acetate resin, acrylic resin, nitrile rubber, or the like is used.

The pressure-sensitive adhesive layer may be appropriately added and blended with an ultraviolet absorber, an antioxidant, an antistatic agent, a heat stabilizer, a lubricant, a filler, a coloring agent, an adhesion adjusting agent, and the like.

(Use)
The thermal barrier film according to this embodiment can be applied to a wide range of fields. For example, it is attached to equipment 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.

[Heat shield]
In particular, the heat shield film according to one embodiment of the present embodiment can be suitably used as a heat shield. A heat shield means that a heat shield film is bonded directly to a substrate such as glass or a glass substitute resin through an adhesive layer, or when the heat shield film has an adhesive layer, through an adhesive layer. The member which becomes.

The material for forming the substrate is not particularly limited, but specific examples include, for example, glass, polycarbonate resin, polysulfone resin, acrylic resin, polyolefin resin, polyether resin, polyester resin, polyamide resin, polysulfide resin, unsaturated polyester resin. , Epoxy resin, melamine resin, phenol resin, diallyl phthalate resin, polyimide resin, urethane resin, polyvinyl acetate resin, polyvinyl alcohol resin, styrene resin, vinyl chloride resin and the like, metal plates, ceramics and the like. As the type of resin for forming the substrate, any of a thermoplastic resin, a thermosetting resin, and an ionizing radiation curable resin can be used. Two or more different types of resins may be used in combination. From the viewpoint of practicality, the material forming the substrate is particularly preferably glass. The substrate can be produced by a known method such as extrusion molding, calendar molding, injection molding, hollow molding, compression molding or the like. The thickness of the substrate is not particularly limited, but is preferably 0.1 mm to 5 cm.

The substrate may be flat or curved. The method of thermoforming for laminating with a substrate having a curved surface is not particularly limited, but generally, a hard coat layer of a thermal barrier film is provided on one side of the substrate having a curved surface, that is, with respect to the substrate. The substrate is deformed along the shape of the substrate in the state facing the substrate side, and then the hard coat layer of the heat shielding film is on the opposite side of the substrate having a curved surface, that is, opposite to the substrate with respect to the substrate. A method of bonding to the base body in a state directed to the side is used.

Therefore, another preferred embodiment of the present invention is a heat shield obtained by bonding a heat shield film to a substrate.

As described above, the heat-shielding film according to one embodiment of the present invention may be bonded to a substrate via an adhesive layer. The adhesive or pressure-sensitive adhesive forming the adhesive layer is not particularly limited, and examples thereof include an adhesive or pressure-sensitive adhesive mainly composed of a photocurable or thermosetting resin. As the adhesive or pressure-sensitive adhesive, those having durability against ultraviolet rays are preferable. Specifically, the adhesive or pressure-sensitive adhesive is preferably an acrylic pressure-sensitive adhesive or a silicone pressure-sensitive adhesive, and more preferably an acrylic pressure-sensitive adhesive from the viewpoint of pressure-sensitive adhesive properties and cost. As the acrylic pressure-sensitive adhesive, a solvent type is preferable because it is particularly easy to control the peel strength. When a solution polymerization polymer is used as the acrylic solvent-based pressure-sensitive adhesive, known monomers can be used as the monomer. As the adhesive or pressure-sensitive adhesive, polyvinyl butyral resin or ethylene-vinyl acetate copolymer resin may be used. Specific examples of the polyvinyl butyral resin or the ethylene-vinyl acetate copolymer resin include, for example, plastic polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., Mitsubishi Monsanto Kasei Co., Ltd., etc.), ethylene-vinyl acetate copolymer (DuPont). And a modified ethylene-vinyl acetate copolymer (manufactured by Tosoh Corporation, Mersen G (registered trademark)).

In the adhesive layer, an ultraviolet absorber, an antioxidant, an antistatic agent, a heat stabilizer, a lubricant, a filler, a coloring agent, an adhesion adjusting agent, and the like may be appropriately added and blended.

[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).

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the following examples and comparative examples, a thermal barrier film having a hard coat layer containing a base material and tungsten oxide was produced, and various evaluations were performed.

<< 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 hard coat layer coating solution HC1)
Mixture of Aronix (registered trademark) M-405 (dipentaerythritol pentaacrylate: dipentaerythritol hexaacrylate = 10-20: 90-80 (mass ratio) as a (meth) acrylate compound (component (b)), Toagosei 390 parts by mass) and EBECRYL (registered trademark) 350 (silicone diacrylate, manufactured by Daicel Ornex Co., Ltd.) 0.4 parts by mass are mixed, and a cesium-doped tungsten oxide dispersion (YMF) is obtained as a composite tungsten oxide. -02A, total solid concentration 28% by mass (cesium doped tungsten oxide (component (a)) concentration 18.5% by mass), composition: Cs _0.33 WO ₃ , average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd. ) 650 parts by mass, nickel perchlorate (N) as metal salt (component (c)) i) 3 parts by mass of hexahydrate (manufactured by Kanto Chemical Co., Ltd.) and 300 parts by mass of methyl ethyl ketone as a solvent were added. Furthermore, as a polymerization initiator, Irgacure (registered trademark) 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, manufactured by BASF Japan Ltd.), 20 parts by mass, a fluorosurfactant (phthalgent (registered) (Trademark) 650A, manufactured by Neos Co., Ltd.) 0.5 parts by mass was added to prepare a hard coat layer coating solution HC1.

(Preparation of coating liquid HC2 for hard coat layer)
The hard coat layer is the same as the hard coat layer coating solution HC1, except that nickel perchlorate (Ni) hexahydrate as the metal salt is changed to magnesium stearate (Mg) (manufactured by Kanto Chemical Co., Inc.). Coating solution HC2 was prepared.

(Preparation of coating liquid HC3 for hard coat layer)
Except that nickel perchlorate (Ni) hexahydrate as a metal salt is changed to zinc acetate (Zn) (anhydrous) (manufactured by Kanto Chemical Co., Inc.) A coating layer coating solution HC3 was prepared.

(Preparation of coating liquid HC4 for hard coat layer)
Nickel perchlorate (Ni) hexahydrate as a metal salt is replaced with bis (2-ethylhexanoic acid) zinc (Zn) (solid content 80% mineral spirit solution, manufactured by Wako Pure Chemical Industries, Ltd.) 3.8 A hard coat layer coating solution HC4 was prepared in the same manner as the hard coat layer coating solution HC1, except that the amount was changed to parts by mass.

(Preparation of hard coat layer coating solution HC5)
Aronix (registered trademark) M-405 (dipentaerythritol pentaacrylate: dipentaerythritol hexaacrylate = 10-20: 90-80 (mass ratio) mixture as a (meth) acrylate compound (component (b)), Tojo Changed to Aronix (registered trademark) M-402 (mixture of dipentaerythritol pentaacrylate: dipentaerythritol hexaacrylate = 30-40: 70-60 (mass ratio), manufactured by Toagosei Co., Ltd.) In addition, except for changing the addition amount of bis (2-ethylhexanoic acid) zinc (Zn) as a metal salt to 0.076 parts by mass, the same for the hard coat layer coating solution HC4, the hard coat layer use A coating solution HC5 was prepared.

(Preparation of coating liquid HC6 for hard coat layer)
The coating liquid HC6 for hard coat layer was the same as the coating liquid HC5 for hard coat layer, except that the addition amount of bis (2-ethylhexanoic acid) zinc (Zn) as the metal salt was changed to 0.38 parts by mass. Adjusted.

(Preparation of coating liquid HC7 for hard coat layer)
The coating liquid HC7 for hard coat layer was the same as the coating liquid HC5 for hard coat layer, except that the addition amount of bis (2-ethylhexanoic acid) zinc (Zn) as the metal salt was changed to 3.8 parts by mass. Adjusted.

(Preparation of hard coat layer coating solution HC8)
The coating liquid HC8 for the hard coat layer was the same as the coating liquid HC5 for the hard coat layer, except that the addition amount of bis (2-ethylhexanoic acid) zinc (Zn) as the metal salt was changed to 7.6 parts by mass. Adjusted.

(Preparation of coating liquid HC9 for hard coat layer)
The hard coat layer coating solution HC9 was prepared in the same manner as the hard coat layer coating solution HC5, except that the amount of bis (2-ethylhexanoic acid) zinc (Zn) added as a metal salt was changed to 38 parts by mass. did.

(Preparation of coating liquid HC10 for hard coat layer)
Aronix (registered trademark) M-405 (dipentaerythritol pentaacrylate: dipentaerythritol hexaacrylate = 10-20: 90-80 (mass ratio) mixture as a (meth) acrylate compound (component (b)), Tojo Except that Synthetic Co., Ltd. was changed to Aronix (registered trademark) M-305 (a mixture of pentaerythritol triacrylate: pentaerythritol tetraacrylate = 55 to 63:45 to 37 (mass ratio), manufactured by Toagosei Co., Ltd.) Prepared a hard coat layer coating solution HC10 in the same manner as the hard coat layer coating solution HC4.

(Preparation of hard coat layer coating solution HC11)
Aronix (registered trademark) M-405 (a mixture of dipentaerythritol pentaacrylate: dipentaerythritol hexaacrylate = 10-20: 90-80 (mass ratio) as a (meth) acrylate compound, manufactured by Toagosei Co., Ltd.) A hard coat layer coating solution HC11 was prepared in the same manner as the hard coat layer coating solution HC2, except that it was changed to Kayalad (registered trademark) TTMPA (trimethylolpropane triacrylate, manufactured by Nippon Kayaku Co., Ltd.).

(Preparation of coating solution for low refractive index layer)
380 parts by mass of colloidal silica (concentration: 10% by mass, Snowtex (registered trademark) OXS, average particle size of primary particles: 4 to 6 nm, manufactured by Nissan Chemical Industries, Ltd.), 50 parts by mass of boric acid aqueous solution (concentration: 3 mass) %), 300 parts by weight of polyvinyl alcohol (concentration: 4% by weight, JP-45, polymerization degree: 4500, saponification degree: 88 mol%, manufactured by Nippon Acetate / Poval) 3 parts by weight of an aqueous surfactant solution ( A concentration of 5% by mass, Softazoline (registered trademark) 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 (concentration 15.0% by mass, SRD-W, volume average particle size: 5 nm, rutile titanium dioxide particles, manufactured by Sakai Chemical Industry Co., Ltd.) Heated to 90 ° 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 (concentration 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 (concentration 8). (Mass%, EXEVAL® RS-2117, ethylene modification degree 3.0 mol%, saponification degree: 97.5 to 99 mol%, polymerization degree 1700, manufactured by Kuraray Co., Ltd.) A high refractive index layer coating solution was prepared by adding 0.4 parts by mass of a 5% by weight aqueous surfactant solution (SOFTAZOLINE (registered trademark) LSB-R, manufactured by Kawaken Fine Chemical Co., Ltd.).

(Preparation of thermal barrier film sample 1: Example 1)
On a substrate (polyethylene terephthalate film with a thickness of 50 μm, Cosmo Shine (registered trademark) A4300, manufactured by Toyobo Co., Ltd.), a hard coat layer coating solution HC1 was applied with a gravure coater under the condition that the dry film thickness was 5 μm And dried at 90 ° C. for 1 minute. Next, the coating film is hardened by irradiating the coating film by irradiating ultraviolet rays from the surface far from the substrate 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 using an ultraviolet lamp. A layer was formed, and a thermal barrier film sample 1 was produced.

(Preparation of thermal barrier film samples 2 to 10 and 12: Examples 2 to 10 and Comparative Example 1)
Thermal barrier film samples 2 to 10 and 12 were prepared in the same manner as the thermal barrier film sample 1, except that the hard coat layer coating liquid HC1 was changed to the hard coat layer coating liquids HC2 to 11, respectively.

(Preparation of thermal barrier film sample 11: Example 11)
Using a slide hopper coating apparatus, a substrate 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. (polyethylene terephthalate film having a thickness of 50 μm, Cosmo Shine ( (Registered Trademark) A4300 (manufactured by Toyobo Co., Ltd.) was applied to 11 layers simultaneously (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, the hard coat layer coating solution HC10 was applied to the surface of the substrate opposite to the surface on which the dielectric multilayer film was formed, with a gravure coater under the condition that the dry film thickness was 5 μm, and 90 ° C. For 1 minute. Next, the coating film is hardened by irradiating the coating film by irradiating ultraviolet rays from the surface far from the substrate 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 using an ultraviolet lamp A layer was formed, and a thermal barrier film sample 11 was produced.

Details of these thermal barrier film samples 1 to 12 are shown in Table 1.

<< Measurement of hydroxyl value of (meth) acrylate compound (component (b)}
The hydroxyl value of the (meth) acrylate compound (component (b)) was measured according to JIS K 0070 (1992).

Specifically, a sample having a total mass Xg (1 g) prepared by mass ratio of each component contained in component (b) to be actually added to the hard coat coating solution is precisely weighed in a flask, and an acetylating reagent is added to the flask. 20 mL (accurately added to 400 mL by adding pyridine to 20 mL) was added accurately. Next, an air cooling tube was attached to the mouth of the flask and heated in a glycerin bath at 95 to 100 ° C. After 1 hour 30 minutes, the mixture was cooled, 1 mL of purified water was added from an air cooling tube, and acetic anhydride was decomposed into acetic acid. Next, titration was performed with a 0.5 mol / L potassium hydroxide ethanol solution using a potentiometric titrator, and the inflection point of the obtained titration curve was set as the end point. Further, as a blank test, titration was performed without a sample, and the inflection point of the titration curve was obtained. The hydroxyl value was calculated by the following formula.

Hydroxyl value = {(BC) × f × 28.05 / X} + D
(In the formula, B is the amount of 0.5 mol / L potassium hydroxide ethanol solution (mL) used for the blank test, and C is the amount of 0.5 mol / L potassium hydroxide ethanol solution used for titration (mL). F represents a factor of 0.5 mol / L potassium hydroxide ethanol solution, D represents an acid value, and 28.05 represents 1/2 of 1 mol amount of potassium hydroxide 56.11)
The above evaluation results are shown in Table 1.

<Evaluation of thermal barrier film>
<Adhesion of hard coat layer>
Using a 1506 mandrel bending tester (manufactured by Elcometer) set with a mandrel having a diameter of 10 mm, the thermal barrier film samples 1 to 12 were bent with the hard coat layer arranged on the outside, and then JIS-K5600-5-6: According to the 1999 cross-cut method, a single-blade razor blade was cross-cut at an angle of 90 ° with respect to the surface at an interval of 2 mm on the outermost surface of the surface disposed on the outer side to produce a 10-mm square grid. Cellophane tape No. manufactured by Nitto Denko Corporation 29 was affixed, the tape was peeled off, and the peeling state of the film was examined.

F = n1 / n × 100 (%) is calculated, where n is the number of cross-cut cells and n1 is the number of cells remaining on the support after peeling off the tape. Based on the average value of the sheet, the evaluation was made according to the following criteria.

A: F ≧ 90%
○: 90%> F ≧ 80%
Δ: 80%> F ≧ 70%
×: 70%> F
In actual use, when F is 70% or more, it can be said that interlayer adhesion is secured.

<Tone change (discoloration)>
The prepared thermal barrier film samples 1 to 12 are attached to glass, and using a super xenon weather meter (Suga Test Instruments Co., Ltd. SX75), with a radiation intensity of 180 W / m ² , rainfall of 18 minutes / 60 minutes in cycle conditions. Irradiation was performed for 1000 hours (weather resistance test). A transmission spectrum was measured using a spectrophotometer (using an integrating sphere, manufactured by Hitachi, Ltd., model U-4000), and a color difference (ΔE) before and after the weather resistance test was calculated. The average rank of 6 test samples was given the following rank.

A: ΔE is less than 1.5 B: ΔE is 1.5 or more and less than 2.0 Δ: ΔE is 2.0 or more and less than 2.5 ×: ΔE is 2.5 or more.

In actual use, if ΔE is less than 2.5, it can be said that discoloration (weather resistance) is ensured.

<Haze>
For each heat shield film, the haze of 10 heat shield film samples was measured using a haze meter (NDH2000 type, manufactured by Nippon Denshoku Industries Co., Ltd.), and then the average value of 10 heat shield film samples was calculated. This value was taken as the haze value.

Table 2 shows the above evaluation results.

From the results in Table 2, it was shown that the heat-shielding films (Examples 1 to 11) according to an embodiment of the present invention have good adhesion of the hard coat layer and suppress discoloration of the hard coat layer. .

Further, by comparing the thermal barrier films 4, 7 and 10 according to Examples 4, 7 and 10, the discoloration of the hard coat layer was achieved by setting the hydroxyl value of the (meth) acrylic compound (component (b)) to 40 or more. It was confirmed that the suppression effect was further increased. Moreover, it was confirmed that the adhesive improvement effect of a hard-coat layer increases further by making the hydroxyl value of a (meth) acrylic-type compound ((b) component) into 80 or more.

Further, from the comparison of the thermal barrier films 1 to 4 according to Examples 1 to 4, the metal salts include magnesium stearate (Mz), zinc acetate (Zn), and bis (2-ethylhexanoic acid) zinc (Zn). It was confirmed that discoloration of the hard coat layer can be further suppressed by using the carboxylate. Further, it was confirmed that further haze reduction can be achieved by using 2-ethylhexanoic acid as the carboxylic acid constituting the metal salt.

Further, from the comparison of the heat-shielding films 5 to 9 according to Examples 5 to 9, the addition amount of the metal salt was 0.01 to 5.5 with respect to the total mass of the components excluding the solvent of the hard coat layer coating solution. It was confirmed that the adhesiveness and discoloration suppressing effect of the hard coat layer were improved by setting the content to 0% by mass. It was also confirmed that the adhesion of the hard coat layer was further increased and further haze reduction could be realized by adding 0.01 to 1.0% by mass of the metal salt. Furthermore, it was confirmed that the discoloration of the hard coat layer can be further suppressed by setting the addition amount of the metal salt to 0.05 to 0.5% by mass.

<Production and evaluation of heat shield>
Heat shields 1 to 11 were produced using the above heat shield film samples 1 to 11. The heat shielding film samples 1 to 11 were bonded with an acrylic adhesive on a transparent acrylic resin plate having a thickness of 5 mm and 20 cm × 20 cm to produce the heat shielding bodies 1 to 11, respectively.

It was confirmed that the heat shields 1 to 11 produced above had good adhesion and discoloration suppression of the hard coat layer. In addition, despite its large size, it was easily available, and excellent heat shielding performance could be confirmed. Moreover, when the thermal insulation film sample 11 which has a dielectric multilayer film was utilized, the especially outstanding thermal insulation performance was able to be confirmed.

This application is based on Japanese Patent Application No. 2014-247437 filed on December 5, 2014, the disclosure of which is incorporated by reference in its entirety.

Claims (8)

1. A base material and the following (a) to (c) disposed on at least one surface of the base material:
   (A) Tungsten oxide (b) A (meth) acrylate-based compound that essentially contains a (meth) acrylate-based compound having a primary hydroxyl group, and (c) a hardened layer coating solution that contains a metal salt. A thermal barrier film having a hard coat layer.
2. The thermal barrier film according to claim 1, wherein the (a) tungsten oxide is a cesium-containing composite tungsten oxide.
3. The thermal barrier film according to claim 1 or 2, wherein the metal salt (c) is a carboxylate.
4. The heat shield according to any one of claims 1 to 3, wherein the hydroxyl value of the (meth) acrylate compound, which essentially includes the (b) (meth) acrylate compound having a primary hydroxyl group, is 10 or more. the film.
5. The thermal barrier film according to claim 4, wherein the (b) hydroxyl group value of the (meth) acrylate compound, which essentially includes the (meth) acrylate compound having a primary hydroxyl group, is 40 or more.
6. 6. The thermal barrier film according to claim 1, comprising a dielectric multilayer film in which high refractive index layers and low refractive index layers are alternately laminated.
7. A heat shield obtained by bonding the heat shield film according to any one of claims 1 to 6 to a substrate.
8. On at least one side of the substrate,
   The following (a) to (c);
   (A) Tungsten oxide (b) A (meth) acrylate compound having a primary hydroxyl group and a (meth) acrylate compound (c) A hard coat layer coating solution containing a metal salt is formed on the substrate. A method for producing a thermal barrier film, comprising a step of curing the coating film by irradiating ultraviolet rays after coating.