WO2016088852A1

WO2016088852A1 - Heat-shielding film, production method therefor, and heat shield using said film

Info

Publication number: WO2016088852A1
Application number: PCT/JP2015/084055
Authority: WO
Inventors: 明土川浪; 小沼　太朗; 聡史久光
Original assignee: コニカミノルタ株式会社
Priority date: 2014-12-05
Filing date: 2015-12-03
Publication date: 2016-06-09
Also published as: JP2018015898A

Abstract

The present invention provides a means with which it is possible to, in a heat-shielding film that includes a hard coat layer having heat-shielding properties, suppress appearance defects and separation of the hard coat layer during hot forming when adhering said film to a substrate such as curved glass. The present invention provides a heat-shielding film comprising: a substrate having a thickness of 10-100 μm; and a hard coat layer formed from the cured product of a hard-coat-layer coating fluid that is disposed on at least one surface of the substrate, and that includes (a) a cesium-containing composite tungsten oxide, (b) an ultraviolet-curable component including a tetrafunctional or lower multifunctional (meth)acrylate in the amount of 50 mass% or less with respect to the total mass of the ultraviolet-curable component, and (c) a photopolymerization initiator. The change in visible light transmittance of the film before and after a tape peeling test when said tape peeling test is performed following a heat treatment is 20% or less.

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 thermal barrier film having a thermal barrier hard coat layer, the peeling of the hard coat layer at the time of thermoforming at the time of bonding to a substrate such as curved glass, and poor appearance. The present invention relates to a technology for suppressing generation. 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. For this reason, the heat-shielding film generally has a hard coat layer for surface protection 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. Here, the specific active energy ray-curable compound described above is mainly composed of a polyfunctional acrylate monomer having 5 or more functional groups, and with such a configuration, a film with good film curl can be obtained. (See, for example, Japanese Patent Application Laid-Open No. 2008-200383 (corresponding to US Patent Application Publication No. 2010/015379)).

In the film according to the invention of JP 2008-200903 A (corresponding to US Patent Application Publication No. 2010/015379), a certain curling improvement effect is recognized. However, such a film has a problem that, depending on the material forming the hard coat layer, the hard coat layer may be peeled off during heat molding when bonded to a substrate such as curved glass, and an improvement has been desired. . In addition, such a film has been desired to be improved because defects in its appearance such as scratches on the heat-shielding film and changes in color tone during heat molding at the time of bonding to a substrate such as curved glass.

Therefore, the present invention provides a thermal barrier film having a thermal barrier hard coat layer, which reduces curling, peels off the hard coat layer during heat molding at the time of bonding to a substrate such as curved glass, and the appearance. It aims at providing the thermal-insulation film which suppressed generation | occurrence | production of the defect of this.

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

A substrate having a thickness of 10 to 100 μm;
The following (a) to (c) arranged on at least one surface side of the substrate:
(A) Cesium-containing composite tungsten oxide (b) Ultraviolet curable component containing polyfunctional (meth) acrylate having a tetrafunctional or lower functionality of 50% by mass or more based on the total mass of the ultraviolet curable component (c) Initiating photopolymerization A hard coat layer comprising a cured product of a coating liquid for hard coat layer containing an agent,
The thermal insulation film whose change of the visible light transmittance | permeability of the film before and behind a tape peeling test is 20% or less when a tape peeling test is performed after heat processing.

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>
In one embodiment of the present invention, a base material having a thickness of 10 to 100 μm and the following (a) to (c) disposed on at least one surface side of the base material:
(A) Cesium-containing composite tungsten oxide (b) Ultraviolet curable component containing polyfunctional (meth) acrylate having a tetrafunctional or lower functionality of 50% by mass or more based on the total mass of the ultraviolet curable component (c) Initiating photopolymerization And a hard coat layer comprising a cured product of a hard coat layer coating solution containing an agent, and when the tape peel test is performed after the heat treatment, the change in visible light transmittance of the film before and after the tape peel test is 20 % Relating to a thermal barrier film. According to the film having such a configuration, in addition to reducing curling, the peeling of the hard coat layer at the time of thermoforming at the time of bonding to a substrate such as curved glass and the occurrence of defects in appearance are suppressed. be able to.

In the hard coat layer containing the cesium-containing composite tungsten oxide that is a heat ray shielding metal oxide, the present inventors add a polyfunctional (meth) acrylate having 5 or more functional groups to 50 mass% or more of the total mass of the ultraviolet curable component. When used, it has been found that the frequency of occurrence of peeling of the hard coat layer during heat molding and appearance defects increases.

Then, as a result of investigations, the present inventors have found that, in the hard coat layer containing the cesium-containing composite tungsten oxide, the ultraviolet curable component for forming the hard coat layer is 50% of the total mass. The inventors have found the surprising fact that peeling and poor appearance can be improved while maintaining a good curl-inhibiting effect by containing a polyfunctional (meth) acrylate of 4% or less by mass and not less than 4% by mass. And the change of visible light transmittance of the film before and after the tape peeling test of the thermal barrier film is found to be 20% or less, and it can be found that peeling and poor appearance during actual thermoforming can be greatly suppressed, and the present invention is completed. It came to do.

The present inventors have speculated as follows about the mechanism by which the peeling of the hard coat layer during thermoforming and the appearance defect are suppressed by using the thermal barrier film according to one embodiment of the present invention. .

The heat-shielding film is thermoformed at a temperature at which the base material is softened and the shape of the heat-shielding film can be sufficiently changed. At this time, the base material of the heat-shielding film contracts greatly, but the hard coat layer hardly contracts as compared with the base material. Here, the hard coat layer formed from the coating liquid for the hard coat layer having a polyfunctional (meth) acrylate having five or more functional groups and a large number of functional groups as the main component of the ultraviolet curable component is reduced in toughness and becomes brittle with curing. For this reason, it cannot follow the deformation of the base material at the time of heat forming, and peeling easily occurs, and the hard coat layer is easily broken.

Furthermore, cesium-containing composite tungsten oxide, which is one of the heat ray shielding metal oxides that functions as an excellent infrared absorber, has a wide particle size distribution of several nm to several hundred nm depending on the manufacturing method. is doing. Among these, a component having a large particle size is likely to become a starting point of a crack because shrinkage stress is easily accumulated when shrinkage of the hard coat layer occurs during heat molding. Such cracks cause destruction, and cause peeling that starts from the location of the destruction.

Further, such peeling or destruction results in scratches on the hard coat layer itself, and color changes occur due to partial defects in the hard coat layer itself.

On the other hand, the heat-shielding film according to an embodiment of the present invention has a moderately soft hard coat layer by using a polyfunctional acrylate having a functionality of 4 or less as a main component of an ultraviolet curable component. Such a hard coat layer is less likely to be peeled off due to improved followability to deformation of the substrate during heat molding.

Furthermore, such a hard coat layer has good toughness. Therefore, with the difference in shrinkage between the hard coat layer and the substrate, breakage due to the shrinkage stress generated at the interface between the hard coat layer and the substrate is less likely to occur.

The above mechanism is based on speculation, and its correctness does not affect the technical scope according to one embodiment of the present invention.

Furthermore, the present inventors presumed that the measurement of the change in the visible light transmittance of the film before and after the tape peeling test functions as a compulsory test for peeling and appearance failure occurring during actual heat forming in the heat shielding film. As a result of such a compulsory test, the present inventors have found that, in a film having a change in visible light transmittance of more than 20%, the hard coat layer is peeled off and the appearance frequency is increased. The upper limit of change in light transmittance was defined as 20% or less.

Here, the reason why good results are obtained when the change in visible light transmittance is 20% or less is that the small change in visible light transmittance is a hard coat that may occur during actual heat forming. It is presumed that this means that there is little color change (transmittance change) due to layer abnormality, that is, light scattering due to scratches due to peeling or destruction, and partial defects. Thereby, it is thought that the heat-shielding film satisfying the above-described values suppresses the occurrence of peeling and appearance defects. However, the above mechanism is based on speculation, and its correctness does not affect the technical scope according to one embodiment of the present invention. Here, from the viewpoint of further reducing the frequency of occurrence of peeling and appearance defects, the change in visible light transmittance is preferably 18% or less, and more preferably 15% or less. It is more preferably 10% or less, and particularly preferably 5% or less. The lower limit of the change in visible light transmittance is 0%.

The tape peeling test can be performed according to the cross-cut method of JIS K 5600-5-6: 1999. Visible light transmittance was measured using a spectrophotometer (using an integrating sphere, Hitachi, Ltd.) using a hard coat layer prepared on a 3 mm thick glass plate and a substrate bonded with an adhesive. The U-4000 type manufactured by Seisakusho can be used in accordance with the visible light transmittance test of JIS S 3107: 2013. A detailed measurement method is described in the examples.

And the amount of change in the visible light transmittance of the film before and after the tape peel test is the film thickness of the substrate, the film thickness of the hard coat layer, the content of the cesium-containing composite tungsten oxide in the coating liquid for the hard coat layer, the ultraviolet light It can be controlled by the type and ratio of the curable composition, the type and ratio of the photopolymerization initiator, the amount of light when forming the hard coat layer, the ultraviolet curing conditions such as the light source, and the like.
In addition, in the case of having other optional layers provided between the hard coat layer and the base material, the influence of the shrinkage of the base material is larger in the other layers closer to the base material than in the hard coat layer. Therefore, it is considered that the shrinkage amount of the other layers is larger than that of the hard coat layer. As a result, even when it has other optional layers provided between the hard coat layer and the substrate, the above mechanism reduces curl and heats when bonding to a substrate such as curved glass. It is considered that a heat-shielding film can be provided that suppresses peeling of the hard coat layer during molding and occurrence of defects in appearance.

The heat shield film according to one embodiment of the present invention can also suppress the occurrence of curling as described above. By suppressing curling, workability during construction work can be further improved.

The measurement of curl can be obtained by evaluating the degree when a sample cut to A4 size is deformed in the short side direction. Detailed measurement methods are described in the examples.

The total film thickness of the heat shield film according to one embodiment of the present invention is preferably 12 to 120 μm. When the total film thickness is 120 μm or less, for example, when a heat-shielding film is bonded to a substrate such as glass, followability to a substrate having a curved surface such as curved glass becomes better, and the generation of wrinkles is suppressed. . Moreover, generation | occurrence | production of a wrinkle is suppressed during handling as a total film thickness is 12 micrometers or more. From the same viewpoint, the total film thickness of the heat shielding film is more preferably 25 to 90 μm, and further preferably 25 to 65 μm.

[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, the polyesters forming the film include polyesters mainly composed of polyethylene terephthalate and polyethylene naphthalate, copolymer polyesters composed of terephthalic acid, 2,6-naphthalenedicarboxylic acid and ethylene glycol, and these polyesters. A polyester having a mixture of two or more of the above as main constituent components is more preferred. 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 and having a self-supporting property can be used. Although it does not restrict | limit especially as a dielectric multilayer film which has a self-supporting property, For example, the dielectric multilayer film etc. which were produced by the 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.

The film thickness of the substrate is 10 to 100 μm. If the thickness of the substrate is less than 10 μm, wrinkles are generated during handling. On the other hand, when the thickness of the base material is greater than 100 μm, when the thermal barrier film is bonded to a substrate such as glass, followability to a substrate having a curved surface such as curved glass is deteriorated, and wrinkles are generated. Thus, when the thickness of the substrate is in the range of 10 to 100 μm, wrinkles can be reduced in the heat shield film. Further, when the film thickness of the substrate is in the range of 10 to 100 μm, the change in visible light transmittance of the film before and after the tape peeling test can be further reduced. From the same viewpoint, the thickness of the substrate is preferably 20 to 80 μm, and more preferably 20 to 60 μm.

The substrate is particularly preferably a biaxially oriented polyester film, but a polyester film that has not been stretched or has been stretched in at least one direction can also be used. A stretched film is preferable from the viewpoint of improving strength and suppressing thermal expansion.

[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 is composed of (a) a cesium-containing composite tungsten oxide and (b) a tetrafunctional or lower polyfunctional (meth) acrylate of 50% by mass or more based on the total mass of the ultraviolet curable component. It is formed by applying a coating liquid for hard coat layer containing an ultraviolet curable component containing (c) a photopolymerization initiator on a substrate, and then irradiating with ultraviolet rays to cure the coating film. preferable. That is, the hard coat layer according to one embodiment of the present invention includes the following (a) to (c):
(A) Cesium-containing composite tungsten oxide (b) Ultraviolet curable component containing polyfunctional (meth) acrylate having a tetrafunctional or lower functionality of 50% by mass or more based on the total mass of the ultraviolet curable component (c) Initiating photopolymerization It consists of the hardened | cured material of the coating liquid for hard-coat layers containing an agent.

Here, (a) the cesium-containing composite tungsten oxide is one kind of heat ray shielding metal oxide having infrared absorptivity (also referred to as [infrared shielding metal oxide]) as described later. Thus, the hard coat layer formed from the coating liquid for hard coat layer 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 20 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 20 μm or less, cracking of the hard coat layer due to stress can be prevented. Moreover, the change of the visible light transmittance | permeability of the film before and behind a tape peeling test can be made smaller in a heat-shielding film as it is such a range. From the same viewpoint, the thickness of the hard coat layer is more preferably 1.5 to 15 μm.

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

(A) Cesium-containing composite tungsten oxide Cesium-containing composite tungsten oxide is a kind of heat ray shielding metal oxide having infrared absorptivity.

The coating liquid for hard coat layer according to one embodiment of the present invention essentially contains cesium-containing composite tungsten oxide (hereinafter also referred to as component (a)) that is a heat ray shielding metal compound.

The composition of the cesium-containing composite tungsten oxide is not particularly limited, but is preferably an oxide represented by the general formula: Cs _x W _y O _z from the viewpoint of safety. For example, JP2013-64042A The same ones as described in Japanese Patent Laid-Open No. 2010-215451 can be used. Here, Cs represents cesium, W represents tungsten, and O represents oxygen. x, y, and z generally have a composition of tungsten and Cs (composition of Cs to tungsten, x / y) satisfying 0.001 or more and 1 or less (0.001 ≦ x / y ≦ 1). It is preferable to use a material in which the composition of oxygen and oxygen (composition of oxygen with respect to tungsten, z / y) satisfies 2.0 or more and 3.5 or less (2.0 ≦ z / y ≦ 3.5). Further, the composition of tungsten and Cs (composition of Cs to tungsten, x / y) satisfies the relationship of 0.001 ≦ x / y ≦ 1, and the composition of tungsten and oxygen (composition of oxygen to tungsten, z / y ) Satisfies the relationship of 2.2 ≦ z / y ≦ 3, more preferably satisfies the relationship of 0.01 ≦ x / y ≦ 0.8 and 2.3 ≦ z / y ≦ 3, It is particularly preferable that the relationship 0.1 ≦ x / y ≦ 0.5 and 2.45 ≦ z / y ≦ 3 is satisfied.

The shape of the cesium-containing composite tungsten oxide is not particularly limited, and may take any structure such as a particulate shape, a spherical shape, a rod shape, a needle shape, a plate shape, a columnar shape, an indefinite shape, a flake shape, and a spindle shape, preferably It is particulate. The size of the cesium-containing composite tungsten oxide is not particularly limited. However, when the cesium-containing composite tungsten oxide or the like is in the form of particles, the average particle size (average primary particle diameter, diameter) of the particles such as the cesium-containing composite tungsten oxide is a heat ray while suppressing reflection of visible light. It is preferably 5 to 150 nm, more preferably 5 to 100 nm, and even more preferably 10 to 80 nm, because the absorption effect can be secured, and haze deterioration due to scattering does not occur and transparency can be secured. Preferably, the thickness is 30 to 60 nm, and most preferably 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.

The cesium-containing composite 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 the} like.

Further, these specific trade names are not particularly limited, and examples thereof include CWO dispersion (YMF-02A, manufactured by Sumitomo Metal Mining Co., Ltd.).

The content of the cesium-containing composite tungsten oxide in the hard coat layer is not particularly limited, but the mass of components other than the cesium-containing composite tungsten oxide contained in the hard coat layer (from the mass of the hard coat layer to the cesium-containing composite tungsten oxide) The ratio of the mass of the cesium-containing composite tungsten oxide to the mass excluding the mass of the oxide is preferably 0.05 to 1.0. Here, when the ratio of the mass of the cesium-containing composite tungsten oxide to the mass of components other than the cesium-containing composite tungsten oxide contained in the hard coat layer is 0.05 or more, the ultraviolet curable component in the hard coat layer Since the amount of the polymer formed from is relatively reduced, the shrinkage amount of the hard coat layer at the time of heat molding can be further reduced. As a result, the shrinkage of the hard coat layer during heat forming is less likely to occur, and the shrinkage stress generated at the interface between the hard coat layer and the substrate is also reduced. As a result, deformation such as curling due to shrinkage of the hard coat layer at the time of thermoforming is further suppressed, and further improvement in adhesion is possible. Further, the curl generated after the film formation due to the residual stress at the interface can be further suppressed. When the ratio of the mass of the cesium-containing composite tungsten oxide to the mass of components other than the cesium-containing composite tungsten oxide contained in the hard coat layer is 1.0 or less, the number of cesium-containing composite tungsten oxides in the hard coat layer is Relatively less. As a result, the distance between the particles is increased, so that the film can be more easily formed into a uniform film, and the frequency of occurrence of defects and peeling due to the defective portion can be further suppressed. Moreover, the change of the visible light transmittance | permeability of the film before and behind a tape peeling test can be made smaller in a heat-shielding film as it is such a range. Thus, in a preferred embodiment of the present invention, the ratio of the mass of the cesium-containing composite tungsten oxide to the mass of components other than the cesium-containing composite tungsten oxide contained in the hard coat layer is 0.05 to 1.0. It is a thermal barrier film. From the same viewpoint, it is more preferable that the ratio of the mass of the cesium-containing composite tungsten oxide to the mass of components other than the cesium-containing composite tungsten oxide contained in the hard coat layer is 0.08 to 0.6, It is more preferably 0.1 to 0.4, and particularly preferably 0.20 to 0.4.

The mass of the cesium-containing composite tungsten oxide contained in the hard coat layer can be calculated from the value obtained by measuring the mass of tungsten contained in the hard coat layer using ICP-AES. Detailed measurement methods are described in the examples.

The content of the cesium-containing composite tungsten oxide in the hard coat layer coating solution is not particularly limited, but is preferably 1 to 60% by mass with respect to the total mass of the components excluding the solvent of the hard coat layer coating solution. 5 to 40% by mass is more preferable, 8 to 30% by mass is further preferable, and 18 to 29% by mass is particularly preferable.

(B) Ultraviolet curable component containing a polyfunctional (meth) acrylate having a tetrafunctional or lower functionality of 50% by mass or more with respect to the total mass of the ultraviolet curable component. In the present specification, the ultraviolet curable component is crosslinked by ultraviolet rays. A compound that cures through a reaction or the like is represented. In the present specification, the term “ultraviolet curable component” is a concept that may include not only monomers but also oligomers and prepolymers that can be cured by ultraviolet irradiation.

The coating liquid for hard coat layers according to one embodiment of the present invention comprises (b) an ultraviolet curable component containing a polyfunctional (meth) acrylate having a functionality of 4 or less and 4 functional groups or less based on the total mass of the ultraviolet curable component. (Hereinafter also referred to as component (b)) is essential. Here, the tetrafunctional or lower polyfunctional (meth) acrylate represents a bifunctional (meth) acrylate, a trifunctional acrylate or a tetrafunctional acrylate.

A hard coat layer using an ultraviolet curable component containing 50% by mass or more of a polyfunctional (meth) acrylate having 5 or more functional groups with respect to the total mass of the ultraviolet curable component is likely to be peeled off, and the hard coat layer may be destroyed. It tends to occur. The reason is that the hard coat layer cannot follow the deformation of the base material at the time of heat forming because the deformation such as curling of the heat shielding film becomes large due to the heat shrinkage at the time of heat forming, and the hard coat layer is peeled off or broken. It is presumed that this is likely to occur. Here, when an ultraviolet curable component containing 50% by mass or more of a polyfunctional (meth) acrylate having 5 or more functional groups is used with respect to the total mass of the ultraviolet curable component, the hard coat layer is likely to be peeled off or broken. As described above, it is considered that the hard coat layer formed using such an ultraviolet curable component is caused to become brittle due to a decrease in toughness as curing proceeds. This tendency becomes more prominent particularly when the hard coat layer contains a cesium-containing composite tungsten oxide having a large particle size component. The ultraviolet curable component used in the present embodiment includes the polyfunctional (meth) acrylate having a tetrafunctional or lower functionality of 50% by mass or more based on the total mass of the ultraviolet curable component, thereby solving the above problem.

In order to further enhance the above effect, the ratio of the tetrafunctional or lower polyfunctional (meth) acrylate to the total mass of the ultraviolet curable component is preferably 50 to 100% by mass. Moreover, when there is more content of polyfunctional (meth) acrylate of 4 or less functions, generation | occurrence | production of the curl which generate | occur | produces after film formation is suppressed more. This is because the number of functional groups contributing to the curing reaction is smaller than that of a polyfunctional (meth) acrylate having 5 or more functional groups, so that the heat shrinkage of the hard coat layer is considered to be smaller. Accordingly, it is presumed that the residual stress at the interface between the hard coat layer and the substrate becomes smaller when the ratio of the tetrafunctional or lower polyfunctional (meth) acrylate is larger. From these viewpoints, the ratio of the tetrafunctional or lower polyfunctional (meth) acrylate to the total mass of the ultraviolet curable component is more preferably 60 to 100% by mass, and further preferably 80 to 100% by mass. 100% by mass is particularly preferable.

Although it does not restrict | limit especially as polyfunctional (meth) acrylate below 4 functional used for one form of this invention, For example, polyfunctional (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, polyol (meth) ) Acrylate, polyester (meth) acrylate, silicone (meth) acrylate, isocyanuric acid EO-modified (meth) acrylate, and the like.

“EO” refers to “ethylene oxide”, and “PO” refers to “propylene oxide”. “EO modified” means having a block structure of ethylene oxide units (—CH ₂ —CH ₂ —O—), and “PO modified” means propylene oxide units (—CH ₂ —CH (CH ₃ )). -O-) having a block structure.

Examples of such tetrafunctional or lower polyfunctional (meth) acrylates include bifunctional, trifunctional, and tetrafunctional (meth) acrylate compounds.

The bifunctional (meth) acrylate is not particularly limited. 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 , Neopentyl glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, caprolactone modified dicyclo Examples include pentenyl di (meth) acrylate, ethylene oxide-modified phosphoric acid di (meth) acrylate, isocyanurate di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, and isocyanuric acid EO-modified di (meth) acrylate. Among these, isocyanuric acid EO-modified di (meth) acrylate is preferable, and isocyanuric acid EO-modified diacrylate is more preferable.

Although it does not restrict | limit especially as trifunctional (meth) acrylate, For example, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, trimethylolpropane tri ( Examples include (meth) acrylate, propylene oxide-modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, and isocyanuric acid EO-modified tri (meth) acrylate. Among these, pentaerythritol tri (meth) acrylate or isocyanuric acid EO-modified di (meth) acrylate is preferable, pentaerythritol triacrylate or isocyanuric acid EO-modified triacrylate is more preferable, and pentaerythritol triacrylate is more preferable.

The tetrafunctional (meth) acrylate is not particularly limited, and examples thereof include pentaerythritol tetra (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate. Among these, pentaerythritol tetra (meth) acrylate is preferable, and pentaerythritol tetraacrylate is more preferable.

As the polyfunctional (meth) acrylate having 4 or less functional groups, for example, commercially available products such as Aronix (registered trademark) M-305 and M-313 manufactured by Toagosei Co., Ltd. may be used as appropriate. Here, Aronix (registered trademark) M-305 is a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate, and Aronix (registered trademark) M-313 is isocyanuric acid EO-modified diacrylate and isocyanuric acid EO-modified tri A mixture of acrylates. These details will be described in the examples described later.

In addition, as a polyfunctional (meth) acrylate having 4 or less functional groups, urethane (meth) acrylate and epoxy (meth) are used from the viewpoint of suppressing appearance failure caused by curling of the heat shielding film and peeling and breaking of the hard coat layer. It is preferable to include at least one selected from the group of acrylate, polyol (meth) acrylate, polyester (meth) acrylate, and silicone (meth) acrylate.

Among these, urethane (meth) acrylate and silicone (meth) acrylate are more preferable, and silicone (meth) acrylate is more preferable. Moreover, as silicone (meth) acrylate, commercial items, such as EBECRYL (trademark) 350 by Daicel Ornex Co., Ltd., can be used, for example. Note that details of EBECRYL (registered trademark) 350 will be described in Examples described later.

These polyfunctional (meth) acrylates having 4 or less functional groups can be used alone or in combination of two or more. At this time, a bifunctional to tetrafunctional mixture is preferable from the viewpoint of suppressing appearance failure due to curling of the heat shielding film and peeling and breaking of the hard coat layer.
In addition, the ratio of the trifunctionality to the total mass of the tetrafunctional or lower polyfunctional (meth) acrylate is preferably 0 to 100% by mass, and more preferably 10 to 90% by mass. Further, the ratio of the bifunctionality to the total mass of the tetrafunctional or lower polyfunctional (meth) acrylate is preferably 0 to 40% by mass, more preferably 0 to 10% by mass, and 0 to 1% by mass. % Is particularly preferred.

The number of functional groups of a polyfunctional (meth) acrylate having 4 or less functional groups is trifunctional (meth) acrylate or tetrafunctional (meth) from the viewpoint of appearance failure due to curling of the heat shielding film and peeling and breaking of the hard coat layer. More preferably, the content ratio of the acrylate is higher than that of the bifunctional (meth) acrylate.

In addition, the use of the above preferred tetrafunctional or lower (meth) acrylate, or the use of tetrafunctional or lower (meth) acrylate in the above preferred ratio means that in the heat shielding film, the visible light of the film before and after the tape peeling test. This is also preferable because the change in transmittance can be further reduced.

The compound other than the tetrafunctional or lower polyfunctional (meth) acrylate contained in the ultraviolet curable component is not particularly limited as long as it can be cured by ultraviolet irradiation. Examples of such compounds include compounds having an ethylenically unsaturated double bond. Although it does not restrict | limit especially as a compound which has an ethylenically unsaturated double bond, For example, polyfunctional (meth) acrylate more than 5 functional, urethane (meth) acrylate, epoxy (meth) acrylate, polyol (meth) acrylate, polyester ( A (meth) acrylate etc. can be used.

The polyfunctional (meth) acrylate having 5 or more functional groups is not particularly limited. For example, dipentaerythritol penta (meth) acrylate, propionic acid-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, Caprolactone-modified dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, propionic acid-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) An acrylate etc. are mentioned.

Examples of compounds other than the tetrafunctional or lower polyfunctional (meth) acrylate contained in the ultraviolet curable component include, for example, Aronix (registered trademark) M-402 manufactured by Toagosei Co., Ltd. Commercial products such as registered trademark 7902-1 can be used. Here, Aronix (registered trademark) M-402 is a mixture of dipentaerythritol penta and hexaacrylate, and Hitaroid (registered trademark) 7902-1 is a hexafunctional urethane acrylate. These details will be described in the examples described later.

The ratio of each component in the ultraviolet curable component can be adjusted by weighing each component and mixing them appropriately.

When each component in the ultraviolet curable component, for example, a polyfunctional (meth) acrylate is a mixture of a plurality of polyfunctional (meth) acrylates having different functional groups, or a mixture with other ultraviolet curable resin compositions, The types and ratios of each (meth) acrylate contained are Py-GC / MS (pyrolysis-gas chromatograph / mass spectrometry) (pyrolysis apparatus: PY-2020iD (frontier lab), GG / MS: QP2010 (stock company) It can be measured by using Shimadzu Corporation)).

The content of the ultraviolet curable component 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 total amount of components excluding the solvent of the hard coat layer coating solution is not limited. The amount is preferably 20 to 90% by mass, more preferably 20 to 80% by mass, still more preferably 40 to 80% by mass, and particularly preferably 50 to 70% by mass with respect to the mass.

(C) Photopolymerization initiator The coating liquid for hard coat layer according to one embodiment of the present invention requires a photopolymerization initiator (hereinafter also referred to as component (c)) in order to accelerate the curing of component (b). Including.

Examples of the photopolymerization initiator 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 used. preferable.

The radical photopolymerization initiator is not particularly limited, and for example, acylphosphine oxides, acetophenones, anthraquinones, thioxanthones, ketals, benzophenones and azo compounds can be used.

Acylphosphine oxides are not particularly limited, and examples thereof include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,4,6-trimethylbenzoyl-phenylethoxyphosphine 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.

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.

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

Among these, acylphosphine oxides that are excellent in curability of the hard coat layer at the interface between the hard coat layer and the substrate are preferable. By improving the curability of the hard coat layer at the interface between the hard coat layer and the base material, photopolymerization proceeds sufficiently when the hard coat layer is formed, and the number of uncured components that are thermally cured during subsequent thermoforming is further reduced. As a result, it is considered that the shrinkage amount of the hard coat layer at the time of heat forming can be further reduced. Furthermore, since the shrinkage stress generated at the time of heat molding at the interface between the hard coat layer and the substrate is also reduced, it is considered that the adhesion is improved.

From the above viewpoint, among acylphosphine oxides, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide are more preferable, and bis ( More preferred is 2,4,6-trimethylbenzoyl) -phenylphosphine oxide.

Thus, a preferred embodiment of the present invention is a thermal barrier film in which (c) the photopolymerization initiator includes at least an acyl phosphine oxide photopolymerization initiator.

Further, a more preferable embodiment of the present invention is (c) a thermal barrier film in which the photopolymerization initiator contains at least bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide.

These photopolymerization initiators can be used alone or in combination of two or more. At this time, the ratio of the acylphosphine oxides to the total mass of the photopolymerization initiator is preferably 50 to 100% by mass, and most preferably 100% by mass.

In addition, tertiary amines such as triethanolamine and methyldiethanolamine; photoinitiators such as 2-dimethylaminoethylbenzoic acid and benzoic acid derivatives such as ethyl 4-dimethylaminobenzoate can be used in combination. it can.

These photopolymerization initiators are preferably used in an amount of 0.5 to 20 parts by mass with respect to 100 parts by mass of the ultraviolet curable component. It is preferable that the photopolymerization initiator is 0.5 parts by mass or more with respect to 100 parts by mass of the ultraviolet curable component because the curability becomes better. Moreover, when the photopolymerization initiator is 20 parts by mass or less with respect to 100 parts by mass of the ultraviolet curable component, the shrinkage amount of the hard coat layer can be further reduced, and the curling of the heat shield film and the peeling of the hard coat layer are further reduced. it can. From the same viewpoint, the amount of the photopolymerization initiator used is more preferably 1 to 15 parts by mass, and more preferably 3 to 10 parts by mass with respect to 100 parts by mass of the ultraviolet curable component. More preferably, it is ˜8 parts by mass.

In addition, using the above preferable photopolymerization initiator or using the photopolymerization initiator in the above preferable range makes the change in visible light transmittance of the film before and after the tape peeling test smaller in the heat shielding film. This is also preferable.

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. Among these, the solvent preferably contains ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), and more preferably contains methyl isobutyl ketone.

The content of the solvent in the coating solution for the hard coat layer is not particularly limited, but in general, it is preferably 10 to 80% by mass, and 20 to 80% by mass with respect to the total mass of the coating solution. Is more preferably 50 to 75% by mass, and particularly preferably 60 to 70% by mass.

The coating liquid for hard coat layer may contain an optional component such as a heat ray shielding metal compound other than the component (a) and various additives, if necessary. Examples of additives include metal soaps, surfactants for imparting leveling properties, water repellency, slipping properties, etc .; dyes, pigments, sensitizers, etc. for improving curability by ultraviolet irradiation.

The heat ray shielding metal oxide other than the above (a) is not particularly limited, but zinc oxide, tungsten oxide, antimony doped zinc oxide (AZO), indium doped zinc oxide (IZO), gallium doped zinc oxide ( GZO), aluminum-doped zinc oxide, tin oxide, antimony-doped tin oxide (ATO), and indium-doped tin oxide (ITO). Moreover, as these specific brand names, for example, as a zinc oxide system, the Celnax (registered trademark) series (manufactured by Nissan Chemical Industries, Ltd.), the passette series (manufactured by Hakusui Tech Co., Ltd.); ATO dispersion liquid (SR35M Advanced Nano Products, Inc.), ITO dispersion liquid (Mitsubishi Materials Electronics Kasei Co., Ltd.), KH series (Sumitomo Metal Mining Co., Ltd.), etc. are mentioned.

Also, metal soap functions as a coating liquid desiccant. There is no restriction | limiting in particular as a kind of metal soap, For example, an octylic acid metal soap, a fatty-acid metal soap, etc. are mentioned. Specific examples of these trade names include 8% hexoate cobalt, 15% hexoate zinc, 12% hexoate zirconium, and 6% hexoate manganese manufactured by Toei Chemical Co., Ltd. The content of the metal soap is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, based on the total mass of the components excluding the solvent of the hard coat layer coating solution. It is preferably 0.07 to 2% by mass, more preferably 0.1 to 1.5% 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 or more and 1% by mass, and preferably 0.01% by mass or more and 0.1% by mass with respect to the total mass of the components excluding the solvent of the coating liquid for hard coat layer. It is more preferable that the amount is not more than mass%.

The thermal barrier film according to an aspect of the present invention is
On at least one surface side of the substrate having a thickness of 10 to 100 μm,
The following (a) to (c);
(A) Cesium-containing composite tungsten oxide (b) Ultraviolet curable component containing polyfunctional (meth) acrylate having a tetrafunctional or lower functionality of 50% by mass or more based on the total mass of the ultraviolet curable component (c) Initiating photopolymerization Including a step of curing the coating film by irradiating with ultraviolet rays after applying the coating liquid for hard coat layer,
When the tape peel test is performed after the heat treatment, the film is preferably produced by a method for producing a thermal barrier film in which the change in visible light transmittance of the film before and after the tape peel test is 20% or less.

The film produced by such a production method is
A substrate having a thickness of 10 to 100 μm;
A hard coat layer disposed on at least one side of the substrate;
Have
The hard coat layer is formed by applying a coating liquid for hard coat layer on a substrate and then irradiating ultraviolet rays to cure the coating film.
The hard coat layer coating solution comprises the following (a) to (c):
(A) Cesium-containing composite tungsten oxide (b) Ultraviolet curable component containing polyfunctional (meth) acrylate having a tetrafunctional or lower functionality of 50% by mass or more based on the total mass of the ultraviolet curable component (c) Initiating photopolymerization Including agents,
When the tape peel test is performed after the heat treatment, the change in visible light transmittance of the film before and after the tape peel test is 20% or less.
A substrate having a thickness of 10 to 100 μm;
The following (a) to (c) arranged on at least one surface side of the substrate:
(A) Cesium-containing composite tungsten oxide (b) Ultraviolet curable component containing polyfunctional (meth) acrylate having a tetrafunctional or lower functionality of 50% by mass or more based on the total mass of the ultraviolet curable component (c) Initiating photopolymerization A hard coat layer comprising a cured product of a coating liquid for hard coat layer containing an agent,
When the tape peel test is performed after the heat treatment, it is a preferable embodiment of the heat shielding film in which the change in visible light transmittance of the film before and after the tape peel test is 20% or less.

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

Moreover, there is no restriction | limiting in particular also about the method of apply | coating the coating liquid for 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 40 to 100 ° C., and the drying time is preferably 0.5 to 10 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 in order to reduce the change in visible light transmittance of the film before and after the tape peeling test in the heat shielding film, the illuminance is 80 More preferred is ~ 1000 mW / cm ² . In the case of using an ultraviolet lamp, the amount of irradiation energy is preferably 50 to 1500 mJ / cm ^{2. In} order to reduce the change in visible light transmittance of the film before and after the tape peeling test in the heat shielding film, the amount of irradiation energy is 100 to 1000 mJ / cm ² is preferable. Further, the curing atmosphere may be replaced with nitrogen as necessary. The amount of residual oxygen at the time of substitution is preferably 1% or less, and more preferably 1000 ppm or less.

[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 embodiment of the present invention is a thermal barrier film having 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, one of the low refractive index layer component and the high refractive index layer component does not contain metal oxide particles, and one of the high refractive index layer or the low refractive index layer is formed only from a water-soluble resin (organic binder). Similarly, in the laminated body, it is confirmed that the mixed region exists by measuring the carbon concentration in the film thickness direction, for example, in the water-soluble resin (organic binder) concentration profile. By measuring the composition by EDX, each layer etched by sputtering can be regarded as a high refractive index layer and 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 a smaller number of layers. . The refractive index difference and the required number of layers can be calculated using commercially available optical design software. For example, in order to obtain an infrared 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 standpoint of improving reflectivity 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 above refractive index difference is obtained as a difference between the high refractive index layer and the low refractive index layer obtained by the following method. That is, each refractive index layer is formed as a single layer (using a base material if necessary), and after cutting this sample into 10 cm × 10 cm, the refractive index is obtained according to the following method. Using a U-4000 type (manufactured by Hitachi, Ltd.) as a spectrophotometer, the surface opposite to the measurement surface (back surface) of each sample is roughened, and then light absorption is performed with a black spray. Then, the reflection of light on the back surface is prevented, and the average value is obtained by measuring 25 points of reflectance in the visible light region (400 nm to 700 nm) under the condition of regular reflection at 5 degrees, and the average refractive index is determined from the measurement result. Ask.

Since reflection at the interface between adjacent layers depends on the refractive index ratio between layers, the larger this refractive index ratio, the higher the reflectance. In addition, when the optical path difference between the reflected light on the surface of the layer and the reflected light on the bottom of the layer is a relationship expressed by n · d = wavelength / 4 when viewed as a single layer film, the reflected light is controlled to be strengthened by the phase difference. The reflectance can be increased. Here, n is the refractive index, d is the physical film thickness of the layer, and n · d is the optical film thickness. By 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. Can be used in the same way. 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, and particularly preferably an average degree of polymerization of 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, nonion-modified polyvinyl alcohol, ethylene-modified polyvinyl alcohol, and vinyl alcohol polymers. In addition, polyvinyl acetal resin obtained by reacting aldehyde with polyvinyl alcohol (for example, “ESREC (registered trademark)” manufactured by Sekisui Chemical Co., Ltd.), silanol-modified polyvinyl alcohol having a silanol group (for example, “R manufactured by Kuraray Co., Ltd.) -1130 "), modified polyvinyl alcohol-based resins having an acetoacetyl group in the molecule (for example," Gosefimer (registered trademark) Z / WR series "manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), butenediol-vinyl alcohol copolymer Resins (for example, “Nichigo G Polymer (registered trademark)” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) are also included in the modified polyvinyl alcohol.

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 JP2009-107324A, JP2003-248123A, JP2003-342322A, and the like can be used. Alternatively, commercially available products such as EXEVAL (registered trademark) (trade name: manufactured by Kuraray Co., Ltd.), which is a vinyl acetate resin, may be used.

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 further preferably 60,000 to 250,000. 60,000 to 200,000 is particularly preferable. In the present specification, the value measured by a static light scattering method, gel permeation chromatography (GPC), TOFMASS 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.

Although it does not restrict | limit especially as a metal oxide particle, For example, the metal which comprises a 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 rare earth A metal oxide that is one or two or more metals selected from the group consisting 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 the matters described in Japanese Patent No. 17221. The average particle diameter of the titanium oxide particles 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. More preferably, it is 20 nm. 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. When the coating amount is 30% by mass or less, it is easier 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 formed more stably. is there. 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 WO94 / 26530 pamphlet A. 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 (registered trademark) series (Snowtex (registered trademark) OS, OXS, S, OS, 20, 30, 40, O, N, C, sold by Nissan Chemical Industries, Ltd. Etc.).

(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 Examples thereof include vinyl compounds (1,3,5-trisacryloyl-hexahydro-s-triazine, bisvinylsulfonylmethyl ether, etc.), aluminum alum, borax and the like. The content of the curing agent in the refractive index layer is preferably 1 to 10% by mass, 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. Preferred compounds include those containing a hydrophobic group having 8 to 30 carbon atoms and a sulfonic acid group or a salt thereof in one molecule. 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 adjustment method of the coating liquid for the high refractive index layer and the coating liquid for the low refractive index layer is not particularly limited. For example, a polymer, metal oxide particles, other additives added as necessary, and a solvent are added. And a method of stirring and mixing. At this time, the order of addition of the respective components is not particularly limited, and the respective components may be sequentially added and mixed while stirring, or may be added and mixed all at once while stirring. If necessary, it may be adjusted to an appropriate viscosity using a solvent.

Further, when adjusting the coating solution for forming the high refractive index layer and the coating solution for forming the low refractive index layer, it 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, the volume fluctuation due to the volatilization of the solvent can be further reduced by setting it to 80% by mass or more, handling is further improved, and the uniformity at the time of adding the liquid is further improved by setting it to 99.9% by mass or less. This is because more stable liquid physical 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 when forming a dielectric multilayer film as a reflective layer by a sequential coating method, preferably a low temperature heated to 25 to 60 ° C., more preferably 30 to 45 ° C. Apply either the refractive index layer coating solution or the high refractive index layer coating solution on the substrate and dry it to form a layer, then apply the other coating solution on this layer and dry it. Can be formed. Then, the reflective layer precursor can be obtained by repeating the sequential application so that the number of layers necessary for expressing the desired reflective performance is obtained. When drying, it is preferable to dry the formed coating film at 30 ° C. or higher. Preferably, drying is performed in the range of a wet bulb temperature of 5 to 50 ° C. and a film surface temperature of 5 to 100 ° C. (more preferably 10 to 50 ° C.). For example, warm air of 40 to 85 ° C. is applied for 1 to 5 seconds. Can be sprayed and dried. As a drying method, warm air drying, infrared drying, or microwave drying can be 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 the reflective layer is formed by simultaneous multilayer coating, for example, the coating solution for the low refractive index layer and the coating solution for the high refractive index layer are preferably heated to 25 to 60 ° C. so as to be low on the substrate. After simultaneous multilayer coating of the refractive index layer coating liquid and the high refractive index layer coating liquid, 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. can do. More preferable drying conditions include a wet bulb temperature of 5 to 50 ° C. and a film surface temperature of 10 to 50 ° C. As an example of more preferable drying conditions, for example, it is possible to dry 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 preferably 45 seconds or more. By setting the set time to a certain value or more, the components in the layer can be mixed more sufficiently. On the other hand, by setting the set time short, the interlayer diffusion of the metal oxide nanoparticles can be further 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 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 one embodiment of the present invention 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]
The heat shield film according to one embodiment of the present invention 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.

The thermoforming is preferably performed at a temperature at which the base material is softened and the shape of the heat shield film can be sufficiently changed. The heating temperature is not particularly limited as long as the shape can be changed, but is preferably 100 to 400 ° C, more preferably 120 to 300 ° C, and more preferably 120 to 250 ° C. Further preferred. Further, the heating time is not particularly limited as long as the shape can be changed, but is preferably 0.1 to 30 minutes, more preferably 0.5 to 10 minutes, and more preferably 1 to 5 minutes. More preferably, it is minutes.

The heat-shielding film according to one embodiment of the present invention can be preferably used for the production of a heat-shielding body using a substrate having a curved surface, particularly in applications where it is bonded to a substrate having a curved surface such as curved glass. The reason for this is that it is possible to suitably suppress the peeling of the hard coat layer and the occurrence of defects in appearance when heat-molding into a shape that matches the shape of the substrate. In addition, as a base | substrate which has a curved surface, a curved glass is especially preferable from a practical viewpoint.

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

Furthermore, still another preferable embodiment of the present invention is a heat shield, which is formed by bonding a heat shield film to a substrate having a curved surface.

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 the pressure-sensitive adhesive is more preferably an acrylic pressure-sensitive adhesive or a silicone-based 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). Examples thereof include: manufactured by Takeda Pharmaceutical Co., Ltd., Dumiran (registered trademark), modified ethylene-vinyl acetate copolymer (manufactured by Tosoh Corporation, Mersen (registered trademark) G), and the like.

Note that the 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.

[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). Moreover, the thermal insulation performance (TSER, Total Solar Energy Rejection) of a thermal insulation film or a thermal insulation body can be calculated | required by the measuring method as described in the below-mentioned Example.

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 heat shielding film having a hard coat layer containing a base material and a heat ray shielding metal oxide was produced and subjected to various evaluations.

<< 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)
Each component was mixed to prepare a coating liquid HC1 having the following composition.

YMF-02A (18 mass% Cs _0.33 WO ₃ dispersion, dispersant 10 mass%, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 315 parts by mass Aronix (registered trademark) M-305 (3, Tetrafunctional acrylate, trifunctional component 60% by mass, manufactured by Toagosei Co., Ltd.) 196 parts by mass EBECRYL (registered trademark) 350 (bifunctional silicone acrylate, manufactured by Daicel Ornex Co., Ltd.) MIBK (methyl isobutyl ketone) diluent (1 18% by mass) 18 parts by mass of hexate cobalt 8% (metal soap, manufactured by Toei Kako Co., Ltd.) 3 parts by mass Irgacure (registered trademark) 184 (1-hydroxycyclohexyl phenyl ketone, photopolymerization initiator, BASF Japan Ltd. Manufactured by) 13 parts by mass ・ MegaFac (registered trademark) F-552 (surfactant, DI) Co.) MIBK (methyl isobutyl ketone) diluent (1%) 9 parts by mass · MIBK (methyl isobutyl ketone) 446 parts by weight.

(Preparation of coating liquid HC2 for hard coat layer)
Each component was mixed to prepare a coating liquid HC2 having the following composition.

YMF-02A (18 mass% Cs _0.33 WO ₃ dispersion, dispersant 10 mass%, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 315 mass parts Aronix (registered trademark) M-313 (2, 196 parts by mass of EBECRYL (registered trademark) 350 (bifunctional silicone acrylate, manufactured by Daicel Ornex Co., Ltd.) MIBK diluent (1% by mass) 18% by mass Part ・ Hexoate zinc 15% (metal soap, manufactured by Toei Chemical Co., Ltd.) 3 parts by mass ・ Irgacure (registered trademark) 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, manufactured by BASF Japan Ltd.) 13 parts by mass Megafac (registered trademark) F-552 (surfactant, manufactured by DIC Corporation) MIBK diluent (1%) 9 parts by mass · MIBK 446 parts by mass.

(Preparation of coating liquid HC3 for hard coat layer)
Each component was mixed to prepare a coating liquid HC3 having the following composition.

YMF-02A (18 mass% Cs _0.33 WO ₃ dispersion, dispersant 10 mass%, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 315 parts by mass Aronix (registered trademark) M-305 (3, Tetrafunctional acrylate, trifunctional component 60% by mass, manufactured by Toagosei Co., Ltd.) 117 parts by mass Aronix (registered trademark) M-402 (5, 6 functional acrylate, 5-functional component 35% by mass, manufactured by Toagosei Co., Ltd.) 78 Mass parts-EBECRYL (registered trademark) 350 (bifunctional silicone acrylate, manufactured by Daicel Ornex Co., Ltd.) MIBK diluent (1 mass%) 18 parts by mass-Hexoate zirconium 12% (metal soap, manufactured by Toei Chemical Co., Ltd.) 3 parts by mass Irgacure® 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine In'okisaido, manufactured by BASF Japan Ltd.) 13 parts by weight Megafac (registered trademark) F-552 (surfactant, manufactured by DIC Corporation) MIBK diluent (1%) 9 parts by mass MIBK 446 parts by mass.

(Preparation of coating liquid HC4 for hard coat layer)
Each component was mixed to prepare a coating liquid HC4 having the following composition.

YMF-02A (18 mass% Cs _0.33 WO ₃ dispersion, dispersant 10 mass%, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 315 parts by mass Aronix (registered trademark) M-305 (3, Tetrafunctional acrylate, trifunctional component 60% by mass, manufactured by Toagosei Co., Ltd.) 117 parts by mass ・ Hitaroid (registered trademark) 7902-1 (hexafunctional urethane acrylate, manufactured by Hitachi Chemical Co., Ltd.) 78 parts by mass ・ EBECRYL (registered trademark) 350 (bifunctional silicone acrylate, manufactured by Daicel Ornex Co., Ltd.) MIBK diluent (1% by mass) 18 parts by mass • 6% hexoate manganese (metal soap, manufactured by Toei Chemical Co., Ltd.) 3 parts by mass • Irgacure (registered trademark) ) 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, BAS Japan Ltd.) 13 parts by weight Megafac (registered trademark) F-552 (surfactant manufactured by DIC Corporation) MIBK diluent (1%) 9 parts by mass MIBK 446 parts by mass.

(Preparation of hard coat layer coating solution HC5)
Each component was mixed to prepare a coating liquid HC5 having the following composition.

YMF-02A (18 mass% Cs _0.33 WO ₃ dispersion, dispersant 10 mass%, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 315 parts by mass Aronix (registered trademark) M-305 (3, Tetrafunctional acrylate, trifunctional component 60% by mass, manufactured by Toagosei Co., Ltd.) 196 parts by mass EBECRYL (registered trademark) 350 (bifunctional silicone acrylate, manufactured by Daicel Ornex Co., Ltd.) MIBK diluent (1% by mass) 18% Part ・ hexoate cobalt 8% (metal soap, manufactured by Toei Chemical Co., Ltd.) 3 parts by mass ・ LUCIRIN (registered trademark) TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, manufactured by BASF Japan Ltd.) 13 parts by mass Megafac (registered trademark) F-552 (surfactant, manufactured by DIC Corporation) M IBK diluent (1% by mass) 9 parts by mass-446 parts by mass of MIBK.

(Preparation of coating liquid HC6 for hard coat layer)
Each component was mixed to prepare a coating liquid HC6 having the following composition.

YMF-02A (18 mass% Cs _0.33 WO ₃ dispersion, dispersant 10 mass%, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 315 parts by mass Aronix (registered trademark) M-305 (3, Tetrafunctional acrylate, trifunctional component 60% by mass, manufactured by Toagosei Co., Ltd.) 196 parts by mass EBECRYL (registered trademark) 350 (bifunctional silicone acrylate, manufactured by Daicel Ornex Co., Ltd.) MIBK diluent (1% by mass) 18% Part ・ Hexoate zinc 15% (metal soap, manufactured by Toei Chemical Co., Ltd.) 3 parts by mass ・ Irgacure (registered trademark) 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, manufactured by BASF Japan Ltd.) 13 parts by mass Megafac (registered trademark) F-552 (surfactant, manufactured by DIC Corporation) MIBK diluent (1%) 9 parts by mass · MIBK 446 parts by mass.

(Preparation of coating liquid HC7 for hard coat layer)
Each component was mixed to prepare a coating liquid HC7 having the following composition.

YMF-02A (18 mass% Cs _0.33 WO ₃ dispersion, dispersant 10 mass%, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 122 mass parts Aronix (registered trademark) M-305 (3, Tetrafunctional acrylate, trifunctional component 60 mass%, manufactured by Toagosei Co., Ltd.) 247 mass parts EBECRYL (registered trademark) 350 (bifunctional silicone acrylate, manufactured by Daicel Ornex Co., Ltd.) MIBK diluent (1 mass%) 23 mass Parts ・ hexoate zirconium 12% (metal soap, manufactured by Toei Chemical Co., Ltd.) 3 parts by mass ・ Irgacure (registered trademark) 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, BASF Japan Ltd.) 16 parts by mass ・ MegaFac (registered trademark) F-552 (surfactant, DIC strain) Company Ltd.) MIBK diluent (1%) 9 parts by mass · MIBK 580 parts by weight (Preparation of coating solution for hard coat layer HC8)
Each component was mixed to prepare a coating liquid HC8 having the following composition.

YMF-02A (18 mass% Cs _0.33 WO ₃ dispersion, dispersant 10 mass%, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 148 mass parts Aronix (registered trademark) M-305 (3, Tetrafunctional acrylate, trifunctional component 60% by mass, manufactured by Toagosei Co., Ltd.) 240 parts by mass EBECRYL (registered trademark) 350 (bifunctional silicone acrylate, manufactured by Daicel Ornex Co., Ltd.) MIBK diluent (1% by mass) 22% Part ・ Hexoate Manganese 6% (metal soap, manufactured by Toei Chemical Co., Ltd.) 3 parts by weight ・ Irgacure (registered trademark) 819 (Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, BASF Japan Ltd.) 16 parts by mass ・ MegaFac (registered trademark) F-552 (surfactant, DIC Corporation) ) MIBK diluent (1%) 9 parts by mass · MIBK 562 parts by mass.

(Preparation of coating liquid HC9 for hard coat layer)
Each component was mixed to prepare a coating liquid HC9 having the following composition.

YMF-02A (18% by mass Cs _0.33 WO ₃ dispersion, dispersant 10% by mass, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 464 parts by mass Aronix (registered trademark) M-305 (3, Tetrafunctional acrylate, trifunctional component 60% by mass, manufactured by Toagosei Co., Ltd.) 156 parts by mass EBECRYL (registered trademark) 350 (bifunctional silicone acrylate, manufactured by Daicel Ornex Co., Ltd.) MIBK diluent (1% by mass) 14 mass Part ・ Hexoate Cobalt 8% (metal soap, manufactured by Toei Kako Co., Ltd.) 3 parts by mass ・ Irgacure (registered trademark) 819 (Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, BASF Japan Ltd.) Manufactured by) 10 parts by mass-MegaFac (registered trademark) F-552 (surfactant, DIC Corporation) ) MIBK diluent (1%) 9 parts by mass · MIBK 344 parts by mass.

(Preparation of coating liquid HC10 for hard coat layer)
Each component was mixed to prepare a coating liquid HC10 having the following composition.

YMF-02A (18 mass% Cs _0.33 WO ₃ dispersion, dispersant 10 mass%, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 498 mass parts Aronix (registered trademark) M-305 (3, Tetrafunctional acrylate, trifunctional component 60% by mass, manufactured by Toagosei Co., Ltd.) 147 parts by mass EBECRYL (registered trademark) 350 (bifunctional silicone acrylate, manufactured by Daicel Ornex Co., Ltd.) MIBK diluent (1% by mass) 14 mass Part ・ Hexoate zinc 15% (metal soap, manufactured by Toei Chemical Co., Ltd.) 3 parts by mass ・ Irgacure (registered trademark) 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, manufactured by BASF Japan Ltd.) 10 parts by mass ・ Megafac (registered trademark) F-552 (surfactant, manufactured by DIC Corporation) MIBK diluent (1%) 9 parts by mass · MIBK 320 parts by mass.
(Preparation of hard coat layer coating solution HC11)
Each component was mixed to prepare a coating liquid HC11 having the following composition.

YMF-02A (18 mass% Cs _0.33 WO ₃ dispersion, dispersant 10 mass%, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 315 parts by mass Aronix (registered trademark) M-305 (3, Tetrafunctional acrylate, trifunctional component 60% by mass, manufactured by Toagosei Co., Ltd.) 196 parts by mass EBECRYL (registered trademark) 350 (bifunctional silicone acrylate, manufactured by Daicel Ornex Co., Ltd.) MIBK diluent (1% by mass) 18% by mass Parts ・ hexoate zirconium 12% (metal soap, manufactured by Toei Chemical Co., Ltd.) 3 parts by mass ・ Irgacure (registered trademark) 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, BASF Japan Ltd.) Manufactured by) 13 parts by mass ・ MegaFac (registered trademark) F-552 (surfactant, DIC stock) (Manufactured by the company) MIBK diluted solution (1% by mass) 9 parts by mass MIBK 446 parts by mass.

(Preparation of coating liquid HC12 for hard coat layer)
Each component was mixed to prepare a coating liquid HC12 having the following composition.

YMF-01 (10 mass% Cs _0.33 WO ₃ dispersion, 5 mass% dispersant, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 500 mass parts KAYARAD (registered trademark) DPHA (hexafunctional acrylate, Nippon Kayaku Co., Ltd.) 100 parts by mass • Irgacure (registered trademark) 127 (initiator, manufactured by BASF Japan Ltd.) 5 parts by mass • Toluene 446 parts by mass.

(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 weight of a surfactant solid solution having a solid content concentration of 5% by weight (SOFTAZOLINE (registered trademark) LSB-R, manufactured by Kawaken Fine Chemical Co., Ltd.).

(Preparation of thermal barrier film sample 1: Example 1)
On a base material (a polyethylene terephthalate film having a thickness of 50 μm, Cosmo Shine (registered trademark) A4300, manufactured by Toyobo Co., Ltd.), the hard coat layer coating solution HC1 was applied with a gravure coater and dried at 90 ° C. for 1 minute. . Next, using an ultraviolet lamp, the coating film is cured by irradiating ultraviolet rays from the surface far from the base material of the coating film under the conditions of an illuminance of 100 mW / cm ² , an irradiation amount of 0.2 J / cm ² , and an oxygen concentration of 200 ppm. Thus, a hard coat layer was formed, and a thermal barrier film sample 1 was produced. The thickness of the hard coat layer was appropriately adjusted so that the visible light transmittance was 70%.

(Preparation of thermal barrier film samples 2 to 10: Examples 2 to 10)
Thermal barrier film samples 2 to 10 were produced 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 HC10, 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 21 layers simultaneously (total film thickness: 2.85 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 to dry to produce a dielectric multilayer film (reflective layer) composed of 21 layers.

Next, a hard coat layer coating solution HC11 was applied to the surface of the substrate opposite to the surface on which the dielectric multilayer film was formed, using a gravure coater, and dried at 90 ° C. for 1 minute. Next, using an ultraviolet lamp, the coating film is cured by irradiating ultraviolet rays from the surface far from the base material of the coating film under the conditions of an illuminance of 100 mW / cm ² , an irradiation amount of 0.2 J / cm ² , and an oxygen concentration of 200 ppm. Thus, a hard coat layer was formed, and a thermal barrier film sample 11 was produced. The thickness of the hard coat layer was appropriately adjusted so that the visible light transmittance was 70%.

(Preparation of thermal barrier film sample 12: Comparative Example 1)
A thermal barrier film sample 12 was produced 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 liquid HC12.

<Evaluation of thermal barrier film>
(Content of (a) cesium-containing composite tungsten oxide in components other than solvent in hard coat layer coating solution)
(Mass of hard coat layer)
The heat shielding film samples 1 to 12 and the substrate were cut into 10 cm × 10 cm, and mass measurement was performed. The mass difference between the heat shielding film and the substrate was taken as the mass of the hard coat layer.

(Mass of (a) cesium-containing composite tungsten oxide contained in hard coat layer)
Heat insulation film samples 1 to 12 were heated at 800 ° C. for 3 hours, and the residue was dissolved in an aqueous sodium hydroxide solution. The mass of tungsten was measured using ICP-AES (device name: SPS3520UV, manufactured by Hitachi High-Tech Science Corporation). did. 1.5 times the mass of the obtained tungsten (the mass of tungsten × 1.5) was defined as the mass of Cs _0.33 WO ₃ . The _reason why the ratio is 1.5 times is that the mass ratio of Cs _0.33 WO _{3 to} tungsten is 1.5 times. In addition, also when using other cesium containing composite tungsten oxides other than a cesium containing composite tungsten oxide, the mass of a cesium containing composite tungsten oxide is computable from mass ratio with respect to tungsten similarly.

The mass of Cs _0.33 WO ₃ was subtracted from the mass of the obtained hard coat layer, and the mass of components other than Cs _0.33 WO ₃ contained in the hard coat layer was calculated. _Further, the mass of _{Cs 0.33} WO ₃ were divided by the mass of the components other than _{Cs 0.33} WO _{_3,} calculates a ratio of the mass of _{Cs 0.33} WO ₃ with respect to the mass of the components other than _{Cs 0.33} WO ₃ did. This value was defined as Cs _0.33 WO ₃ mass ratio.

(Change in visible light transmittance before and after heat treatment tape peel test)
(Heat treatment tape peel test)
Heat shielding film samples 1 to 12 were heat-treated at 230 ° C. for 5 minutes, and then a razor blade with a single edge from the hard coat layer side was 90 ° to the surface in accordance with the cross-cut method of JIS K 5600-5-6: 1999. A cross cut was made at intervals of 2 mm at an angle of 10 mm to produce a 10 mm square grid. Cellophane tape No. manufactured by Nitto Denko Corporation 29 was pasted and the tape was peeled off.

(Change in visible light transmittance ΔT% before and after heat treatment tape peel test)
For the thermal barrier film samples 1 to 12, the samples before and after the heat treatment tape peeling test were attached to a 3 mm plate glass using an adhesive having the following composition, and a spectrophotometer (using an integrating sphere, manufactured by Hitachi, Ltd., U-) 4000 type), the visible light transmittance was measured according to the visible light transmittance test of JIS S 3107: 2013, and the amount of change was defined as ΔT (%). If ΔT is 20% or less, it is determined that there is no practical problem.

<Adhesive>
-N-2147 (acrylic adhesive, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 100 parts by mass-Tinuvin (registered trademark) 477 (ultraviolet absorber, manufactured by BASF Japan)
2.1 parts by mass Coronate (registered trademark) HL (curing agent, manufactured by Tosoh Corporation) 5 parts by mass (curl)
When the heat shielding film samples 1 to 12 were cut to A4 size and hung on the short side, the shape of the cylinder when deformed so that the direction of the short side became the circumference of the cylinder was ranked based on the following indices. . If rank 2 or higher, it is determined that there is no practical problem.

5: Does not become a cylinder 4: Has a semi-cylindrical shape (circle diameter is 10 cm or more)
3: Has a cylindrical shape (circle diameter is 5 cm or more and less than 10 cm)
2: Has a double cylindrical shape (circle diameter is 3 cm or more and less than 5 cm)
1: It has three or more cylindrical shapes (circle diameter is less than 3 cm).

(Heat insulation performance (TSER, Total Solar Energy Rejection))
Heat shielding film samples 1 to 12 were attached to a 3 mm plate glass using the above-mentioned adhesive, and a spectrophotometer (using an integrating sphere, manufactured by Hitachi, Ltd., U-4000 type) was used in the region of 300 nm to 2500 nm. The transmittance / reflectance was measured every 5 nm. Next, the heat shielding performance TSER was calculated using the following calculation formula using the solar transmittance T (DS) and the solar reflectance R (DS) obtained by the method described in JIS S 3107: 2013. The hard coat layer was measured toward the detector side of the spectrophotometer. If TSER is 40% or more, it is determined that there is no practical problem.

TSER (%) = ((100−T (DS) −R (DS)) × 0.7143) + R (DS)
The above evaluation results are shown in Table 1.

From the results of Table 1, it was shown that the thermal barrier films of the present invention (Examples 1 to 11) had a small change in visible light transmittance before and after heat treatment tape peeling. As a result, the heat-shielding film of the present invention hardly peels off the hard coat layer even at the time of heat molding such as bonding to curved glass, etc. This means that it is difficult for defects in appearance to occur.

Also, from the comparison of Examples 1, 5, and 6, it was confirmed that when the photopolymerization initiator contains an acylphosphine oxide photopolymerization initiator, the change in visible light transmittance before and after heat treatment tape peeling is small. . Among them, it was confirmed that the one containing bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide had a particularly small change in visible light transmittance before and after the heat treatment tape peeling.

Further, from the comparison of Examples 6 to 10, the ratio of the mass of the (a) cesium-containing composite tungsten oxide to the mass of components other than the (a) cesium-containing composite tungsten oxide contained in the hard coat layer is When it is 0.05 to 1.0, it is excellent in terms of both a change in visible light transmittance before and after heat treatment tape peeling and curl reduction, and when it is 0.1 to 0.4, it is further excellent. Was confirmed.

Further, from Example 11, it was confirmed that the heat shield film had a dielectric multilayer film, thereby having higher heat shield performance.

<Production and evaluation of heat shield>
Heat shields 1 to 11 were produced using the above heat shield film samples 1 to 11.

The above-mentioned pressure-sensitive adhesive layer is formed with a dry film thickness of 10 μm on the base material surface of the heat shield film samples 1 to 10 and the dielectric multilayer film surface of the heat shield film sample 11 to form a release film (MRF-25, Mitsubishi Plastics). Bonded). These films were temporarily fixed with the hard coat layer surface side facing the convex side of curved glass (with a radius of curvature of 3 m or less), and thermoformed from the release film side using a commercially available heat gun. At this time, the set temperature of the heat gun was 400 ° C. When the film was cleanly along the curved glass, the release film was peeled off, and the adhesive layer and the concave surface of the curved glass were attached. At this time, a construction liquid (water containing a surfactant) was sprayed on the adhesive layer and the concave surface of the curved glass, and bonded to each other with a squeegee from the hard coat layer side to obtain heat shields 1 to 11. It was confirmed that the heat shields 1 to 11 did not peel off the hard coat layer even when thermoformed, and the visible light transmittance change was good.

It was confirmed that the heat shields 1 to 11 produced above did not easily peel off the hard coat layer from the heat shield film at the time of thermoforming at the time of bonding to the curved glass. Furthermore, it was confirmed that defects in appearance such as scratches on the film and changes in color due to heat forming hardly occur.

This application is based on Japanese Patent Application No. 2014-247439 filed on December 5, 2014, the disclosure of which is incorporated by reference in its entirety.

Claims

A substrate having a thickness of 10 to 100 μm;
The following (a) to (c) arranged on at least one surface side of the substrate:
(A) Cesium-containing composite tungsten oxide (b) Ultraviolet curable component containing polyfunctional (meth) acrylate having a tetrafunctional or lower functionality of 50% by mass or more based on the total mass of the ultraviolet curable component (c) Initiating photopolymerization A hard coat layer comprising a cured product of a coating liquid for hard coat layer containing an agent,
The thermal insulation film whose change of the visible light transmittance | permeability of the film before and behind a tape peeling test is 20% or less when a tape peeling test is performed after heat processing.
The heat-shielding film according to claim 1, wherein the (c) photopolymerization initiator includes at least an acyl phosphine oxide photopolymerization initiator.
The thermal barrier film according to claim 1 or 2, wherein the (c) photopolymerization initiator contains at least bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide.
The ratio of the mass of the (a) cesium-containing composite tungsten oxide to the mass of components other than the (a) cesium-containing composite tungsten oxide contained in the hard coat layer is 0.05 to 1.0. The thermal barrier film according to any one of claims 1 to 3.
The thermal barrier film according to any one of claims 1 to 4, comprising a dielectric multilayer film in which a high refractive index layer and a low refractive index layer are alternately laminated.
A heat shield obtained by bonding the heat shield film according to any one of claims 1 to 5 to a substrate.
The heat shield according to claim 6, wherein the base has a curved surface.
On at least one surface side of the substrate having a thickness of 10 to 100 μm,
The following (a) to (c);
(A) Cesium-containing composite tungsten oxide (b) Ultraviolet curable component containing polyfunctional (meth) acrylate having a tetrafunctional or lower functionality of 50% by mass or more based on the total mass of the ultraviolet curable component (c) Initiating photopolymerization Including a step of curing the coating film by irradiating with ultraviolet rays after applying the coating liquid for hard coat layer,
The manufacturing method of the thermal insulation film whose change of the visible light transmittance | permeability of the film before and behind a tape peeling test is 20% or less when a tape peeling test is performed after heat processing.