JP2000141534A - Heat-shielding film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the heat-absorbing power in the range of near-infrared rays to far-infrared rays by forming, in a laminated fashion, the heat-shielding film comprising a first film layer with a hard coat layer containing a heat- absorbing compound, an adhesive layer, a second film layer with a metal sputtering layer and a pressure-sensitive layer in that order. SOLUTION: A first film layer with a hard coat layer, containing one or more (meth)acryloyl group in a molecule, which contains a heat-absorbing compound using a fine particle sol of a zinc antimonic anhydride having an infrared absorbing power, is formed. Further on the surface of the first film layer, a polyurethane or an acrylic adhesive layer is applied. In addition, a second film layer with a metal sputtering layer of silver, chromium, aluminum, nickel, titanium oxide, silicon dioxide, indium oxide or the like is formed on the surface of the adhesive layer. On the surface of the second film layer, a solvent-type pressure-sensitive adhesive layer based on an acrylate is laminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a film.
More specifically, the present invention relates to a heat ray-shielding film having good transparency and excellent scratch resistance.

[0002]

2. Description of the Related Art A heat ray-shielding film has the property of transmitting visible light but reflecting or absorbing near-infrared rays-infrared rays (heat rays), and is a material which has been actively researched and developed in recent years. It is. When such a heat ray shielding film is applied to an opening such as a glass window, the film reflects heat rays of sunlight or radiant heat from a room, and has an effect of adjusting sunlight and heat insulation. Transparent heat-insulating films utilizing these characteristics are used for building windows, freezer / refrigerated showcases, heat-insulating surfaces, vehicle windows, etc., and are useful for improving the living environment and saving energy.

[0003] As such a heat ray shielding film, a film coated with chromium, a cobalt complex salt thiol nickel complex, an anthraquinone derivative or the like has been known.
In addition, a heat-ray shielding film obtained by depositing or sputtering a metal such as aluminum or copper is also known.

[0004]

However, in the conventional heat ray blocking film (heat ray absorbing sheet), the heat ray blocking property is improved when the concentration of the heat ray blocking substance is increased, but the heat ray is absorbed to increase the surface temperature of the film. However, there is a problem that the heat ray blocking effect is reduced. In addition, as a heat ray-blocking substance, organic substances have poor durability, and have a drawback that the initial heat ray-blocking effect decreases with changes in environmental conditions or with the passage of time. On the other hand, the complex type has durability, but has a large absorption not only in the near-infrared region but also in the visible region, and has a drawback that its use is limited.

[0005] Further, in a conventional heat-shielding film obtained by vapor deposition or sputtering of a metal, increasing the transparency lowers the heat-shielding ability, and increasing the heat-shielding ability not only lowers the visible light transmittance but also reduces the visible light transmittance. Because it reflects light, when it is attached to window glass etc., the lighting is impaired, not only the interior becomes dark, but there is a fatal defect that it exhibits a mirror phenomenon, and glare due to reflected light from the outside is inevitable from the outside There were also disadvantages. Further, in order to increase transparency and heat ray blocking ability, a multi-layer sputtering method of metal is known, but this method has a disadvantage of increasing cost. From such a situation, it has a high heat ray blocking ability in the near infrared to far infrared region, and has a small reflectance in the visible light region, and a temperature rise on the surface is suppressed. Development was desired.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, completed the present invention. That is, the present invention provides (1) a first film layer having a hard coat layer containing a heat ray absorbing compound, an adhesive layer, a second film layer having a metal sputtering layer, and an adhesive layer in this order. (2) The heat ray-shielding film according to (1), wherein the film has a visible light transmittance of 50% or more.
(3) The heat ray-shielding film according to any one of (1) to (2), which has a haze value of 3 or less, and (4) a primary particle diameter of the heat ray-absorbing compound having an infrared absorbing ability of 0.5 μm.
m (1) to (3)
The heat ray-shielding film according to any one of the above, (5) the heat ray-shielding film according to (4), wherein the metal oxide fine particles are fine particles of anhydrous zinc antimonate.

(6) The hard coat layer is a cured film layer of a resin composition containing active energy ray-polymerizable (meth) acrylate as a main component. (7) The heat ray-shielding film according to any one of (1) to (6), wherein the hard coat layer contains a polymer, and (8) the polymer. Is an acrylic resin, a polyester resin or a butyral resin, (9) the heat ray-shielding film according to (7), wherein the pressure-sensitive adhesive layer is a pressure-sensitive pressure-sensitive adhesive layer (1) to (8). The heat ray-shielding film according to claim 1, (10) (1)
To a windowpane having the heat ray shielding film according to any one of (9) to (9) inside.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The heat ray-shielding film of the present invention comprises:
Under preferable conditions, the visible light transmittance is 50% or more and the haze value is 3 or less. Under more preferable conditions, the visible light transmittance is 60 or more and the haze value is 2 or less.

The heat ray absorbing compound used in the present invention is preferably a metal oxide having an infrared absorbing ability. As a metal oxide having an infrared absorbing ability, a primary particle diameter of 0.5
A metal oxide having a size of not more than μm, preferably not more than 0.1 μm is used. For example, a fine particle sol of anhydrous zinc antimonate is suitable. Since anhydrous zinc antimonate has absorption in the ultraviolet region having a shorter wavelength than the visible light region, an effect of improving the light resistance can be expected for the cured product of the hard coat layer and the layer thereunder.

A method for producing anhydrous zinc antimonate is disclosed in
Obtained by the method described in US Pat. The fine particles of anhydrous zinc antimonate can be obtained, for example, by mixing a zinc compound and colloidal antimony oxide, drying and firing at a high temperature. It is preferable that these metal oxides are adjusted to a form that can be dispersed in an organic solvent. Further, in order to form a transparent metal oxide-containing film with low absorption in the visible light region, the primary particles have a particle size of 0.5 μm or less, preferably 0.1 μm or less.
It is necessary to make ultrafine powder of 1 μm or less. The content of the fine particles of the heat ray-shielding metal oxide in the hard coat layer of the present invention can be arbitrarily selected according to the required heat ray-shielding ability, but without aggregation of the particles in the resin. It must be kept stable.

In the present invention, in order to provide a hard coat layer, a resin composition containing an active energy ray polymerizable (meth) acrylate is used. The active energy ray-polymerizable (meth) acrylate that can be used in the present invention can be arbitrarily selected from ultraviolet or electron beam curable (meth) acrylates having one or more (meth) acryloyl groups in the molecule. , Alone or as a mixture. The (meth) acrylate is roughly classified into a monofunctional (meth) acrylate monomer having one (meth) acrylate group, a polyfunctional (meth) acrylate monomer having two or more (meth) acrylate groups, and a (meth) acrylate oligomer. You.

Specific examples of the monofunctional (meth) acrylate monomer include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, -Ethylhexyl (meth) acrylate, stearyl acrylate, 2-ethylhexyl carbitol acrylate, acryloyloxyethyl acid, lauryl (meth) acrylate, 2-methoxyethyl acrylate, butoxyethyl acrylate, ethoxyethoxyethyl acrylate, stearyl (meth) acrylate, cyclohexyl (Meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobonyl (meth) acrylate, dicyclopentenyl acrylate, benzyl Acrylate, phenylglycidyl ether epoxy acrylate, phenoxyethyl (meth) acrylate, nonylphenol ethoxylated acrylate, acryloyloxyethyl phthalic acid, tribromophenyl acrylate, tribromophenol ethoxylated (meth) acrylate, methyl methacrylate, tribromophenyl methacrylate, methacryloyl Oxyethyl acid, methacryloyloxyethyl maleic acid, methacryloyloxyethyl hexahydrophthalic acid, methacryloyloxyethyl phthalic acid, glycidyl methacrylate, n-butyl methacrylate, ethyl methacrylate, allyl methacrylate, cetyl methacrylate, pentadecyl methacrylate, 2-hydroxyethyl Methacryloyl phosphate, ω-f Ruboxy polycaprolactone monoacrylate, acrylic acid dimer, methoxytriethylene glycol acrylate,
Methoxy polyethylene glycol acrylate, N-vinyl-2-pyrrolidone, phenoxy (poly) ethylene glycol acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth)
Acrylate, β-carboxyethyl acrylate, N
-Methylol acrylamide, N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, Nn-butoxymethyl acrylamide, t-butylacrylamide sulfonic acid, vinyl stearylate,
N-methylacrylamide, N-dimethylacrylamide, N-dimethylaminoethyl (meth) acrylate,
N-dimethylaminopropylacrylamide, acryloylmorpholine, methoxypolyethylene glycol (meth) acrylate, diethylaminoethyl (meth) acrylate, methacryloyloxyethyl succinic acid, and the like.

Examples of polyfunctional (meth) acrylate monomers include, for example, hexanediol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, hydroxypivalate neopentyl, pentaerythritol Diacrylate monostearate, glycol diacrylate, bisphenol A ethylene glycol adduct acrylate, bisphenol F ethylene glycol adduct acrylate, tricyclodecane methanol diacrylate, trishydroxyethyl isocyanurate diacrylate, 2-hydroxy-1-acryloxy-3 -Methacryloxypropane, trimethylolpropane triacry Chromatography, tri trimethylolpropane ethylene glycol adduct triacrylate, trimethylolpropane propylene glycol adduct triacrylate, pentaerythritol triacrylate, tris-acryloyloxyethyl phosphate, tris-hydroxyethyl isocyanurate triacrylate, modified ε
-Caprolactone triacrylate, trimethylolpropaneethoxy triacrylate, glycerin propylene glycol adduct triacrylate, pentaerythritol tetraacrylate, pentaerythritol ethylene glycol adduct tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexa (penta) acrylate, di Examples include, but are not limited to, pentaerythritol monohydroxypentaacrylate, urethane acrylate, epoxy acrylate, polyester acrylate, and the like.

The (meth) acrylate oligomer includes, for example, terminal methacrylate polymethyl methacrylate, terminal styryl methacrylate, terminal methacrylate polystyrene, terminal methacrylate acrylonitrile styrene copolymer, terminal methacrylate polyethylene glycol, and terminal methacrylate styrene-methyl methacrylate copolymer. Examples include macromonomers such as polymers.

These can be used singly or arbitrarily as a mixture, but a (meth) acryloyl group is incorporated in the molecule.
A polyfunctional (meth) acrylate monomer or (meth) acrylate oligomer containing at least two, preferably two to six, is suitable because the film after polymerization is hard and the scratch resistance is good. The ratio of the active energy ray polymerizable (meth) acrylate to the resin component of the resin composition is 50 to 100% by weight, preferably 80 to 100% by weight.
It is. When a polyfunctional (meth) acrylate monomer or a (meth) acrylate oligomer is used as the resin component, the ratio of these to the resin component of the resin composition is 10 to 100% by weight, preferably 30 to 80% by weight.
It is.

In addition to the use of the active energy ray-polymerizable type (meth) acrylate having a (meth) acryloyl group as a resin component, the adhesiveness to a film or the active energy ray polymerization with fine particles of a metal oxide may be used. For the purpose of improving the compatibility with the mold resin, a polymer such as an acrylic resin, a polyester resin, a butyral resin, and a urethane resin can be added. This polymer can be used alone or in combination of two or more. The proportion of this polymer to the resin component of the resin composition is from 0 to 50% by weight, preferably from 0 to 20% by weight, from the viewpoint of the scratch resistance of the coating film.
It is.

In order to stably disperse the above-mentioned ultrafine particles of the metal oxide in a mixture of the active energy ray-polymerizable (meth) acrylate and the polymer added as required, a dispersant is optionally added. Can be added. Various surfactants are used as the dispersant used for such purpose. Examples of the surfactant include a quaternary salt of a higher aliphatic amine, a cationic surfactant such as polyethylene glycol alkylamine, a nonionic surfactant such as a higher fatty acid polyethylene glycol ester, an amphoteric surfactant, and a silicon surfactant. Fluorinated surfactants, polymeric surfactants having an amide ester bond, and the like. The amount of the dispersant added is preferably 0.1 to 15% by weight based on the total weight of the metal oxide.

The resin composition used for forming the hard coat layer can be cured by irradiation with an electron beam or ultraviolet rays. When polymerizing and curing with ultraviolet rays, a photopolymerization initiator is used. The photopolymerization initiator is dissolved in the resin composition in advance. The photopolymerization initiator is not particularly limited, and various types can be used. From the viewpoint of the curability and the strength of the cured film, the amount is preferably 0.1 to 15% by weight, and more preferably 0.5 to 12% by weight, based on the resin component of the resin composition. Examples of the photopolymerization initiator include Irgacure-184 (trade name,
Ciba Geigy), Irgacure 651 (trade name,
Ciba-Geigy Corporation), Darocure-1173 (trade name,
Merck Co., Ltd.), benzophenone, methyl o-benzoylbenzoate, p-dimethylaminobenzoate, thioxanthone, alkylthioxanthone, amines and the like. When polymerizing and curing using an electron beam, such a polymerization initiator is not required.

Further, various slip agents can be added for the purpose of improving the slip property of the surface of the coating film.
Further, an antifoaming agent can be added for the purpose of controlling foam generated when the composition is applied. This dispersion is preferably diluted with various organic solvents to obtain a coating liquid. As the various organic solvents used for dilution, 50 lipophilic solvents are used.
It is preferable to contain at least 50% by weight of, for example, toluene or xylene having a boiling point of 100 ° C. or more.

The first film layer in the present invention comprises, for example, a film of polyethylene terephthalate (PET), polyester, polyethylene, polypropylene, polystyrene, polycarbonate, polyvinyl chloride, poly (meth) acryl, polyamide, polyurethane, or the like.
These film bases preferably have high transparency, but a colored film base may be used as desired. The thickness of this film is preferably about 10 to 100 μm.

The adhesive layer in the present invention is provided for bonding the surface of the first film having no hard coat layer to the second film layer having a metal sputtering layer. As the adhesive layer, for example, a polyurethane adhesive, an acrylic adhesive, or the like can be used. The thickness of the adhesive layer is not particularly limited as long as a sufficient adhesive force is selected, but is preferably 1 to 3 μm.

The second film layer provided with the metal sputtering layer in the present invention is obtained by subjecting one side of the film to metal sputtering. Examples of the metal used for sputtering include silver, chromium, aluminum, nickel, titanium oxide, silicon dioxide, indium oxide, and the like. Examples of the film used here include polyethylene terephthalate (PET) and polycarbonate. The thickness of this film is preferably about 10 to 100 μm. The surface subjected to the metal sputtering treatment in the second film may be in contact with the adhesive layer side or may be in contact with the adhesive layer side, but the one in contact with the adhesive layer side was sputtered. It is preferable for the purpose of protecting the metal from oxidation.

The pressure-sensitive adhesive layer according to the present invention comprises an acrylic solvent-type pressure-sensitive adhesive mainly composed of an acrylate ester of 15-3.
It is preferable to use a pressure-sensitive adhesive which is coated to a thickness of 0 μm, can be applied with water, and has good removability. Pressure sensitive adhesives are more preferred.

The transparent heat ray shielding film of the present invention comprises a first film layer having a hard coat layer containing a heat ray absorbing compound, an adhesive layer, and a second film layer provided with a metal sputtering layer. And a film in which an adhesive layer is laminated in this order. C. containing a heat ray absorbing compound
The first film having a coating layer is, for example, an active energy ray-curable hard coating containing a heat ray absorbing compound.
The ink is applied to a substrate of a transparent film, the solvent is volatilized with hot air if necessary, and then the active ink is irradiated with an active energy ray such as an ultraviolet ray or an electron beam. The coating is performed by a conventional method such as a dipping method, a gravure coating method, a roll coating method, a bar coating method, and a spraying method. The thickness of the coating film is 1 to 10 μm, preferably 1 to 3 μm, from the viewpoint of curling prevention.

The following method can be used as a method for producing an active energy ray-curable hard coat ink containing a heat ray absorbing compound. That is, 0.5
Preferably, a small amount of a dispersant is added to a dispersion of the metal oxide finely dispersed to a size of not more than μm to stabilize the dispersion of the fine particles. Thereafter, by irradiating with an active energy ray, a polymerizable (meth) acrylate monomer or oligomer alone or two or more kinds are added, and a polymerization initiator is further dissolved as necessary to obtain a hard coat ink. At the time of hard coat ink production, an appropriate amount of a solvent and various additives can be added as needed. The method of mixing these components is not limited to this order, and is not particularly limited as long as the method can stabilize the fine particles of the metal oxide.

As the transparent heat ray-shielding film of the present invention, for example, a first film having a hard coat layer containing the above-mentioned heat ray absorbing compound is prepared, and then a second film provided with metal sputtering. Can be manufactured by laminating with an adhesive and then providing a pressure-sensitive adhesive layer.

[0027]

Next, the present invention will be described in more detail with reference to Reference Examples and Examples. In the examples, "parts" indicates parts by weight. Reference Example 1 (Adjustment of Hard Coat Ink) In a container equipped with a stirrer, CELNAX CX-Z600
M3 (trade name, anhydrous zinc antimonate (ZnSb ₂ O ₆ )
Of methanol sol (solid content: 60%), manufactured by Nissan Chemical Industry Co., Ltd.
3.5 parts (trade name, dispersant, manufactured by Zeneca) are added with good stirring. KAYARAD DP
64 parts of HA (trade name, dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.), 30 parts of toluene as a solvent, 5.5 parts of Irgacure-184 and SF-84
21 (trade name, slip agent, manufactured by Toray Dow Corning)
50 parts of IRC-500B (trade name, ultraviolet-curable hard coat agent, manufactured by Nippon Kayaku Co., Ltd.) consisting of 0.5 part and 35 parts of methyl ethyl ketone as a solvent are added, and the mixture is stirred well and cured with ultraviolet rays. To obtain a hard coat ink.

Example 1 A hard coat ink obtained in Reference Example 1 was coated on a transparent polyester film having a thickness of 25 μm with a micro reverse gravure coater, the solvent was dried with hot air, and then a 160 W / cm high pressure mercury lamp was used. And hardened sufficiently to obtain a hard coat film A having excellent transparency and scratch resistance. Film sputtered with metal on a 25 micron polyester film (XH-75 Mate
rial Sciences Corporation, USA) and (XH-6)
3Material Sciences Corporation, USA) and a hard coat film A was laminated via an adhesive to obtain a film of the present invention. Its thermal and abrasion properties,
The haze values are shown in Table 1. The smaller the shielding coefficient, the greater the heat ray shielding effect.

[0029]

[Table 1] Table 1 Visible light solar shading coefficient Scratch haze film Transmittance Reflectivity Transmittance Reflectivity A 82.70 8.60 70.00 7.10 0.86 ◎ 0.3 75.10 11.20 65.10 13.20 0.85-1.8 71.70 11.30 58.50 12.10 0.75 ◎ 1. 8 60.70 16.90 48.20 22.00 0.68-1.8 57.60 16.50 43.20 21.40 0.62 ◎ 1.8

The visible light transmittance is measured according to JIS A 5759. The solar absorptivity was measured according to JIS R 3106. The shielding coefficient is measured according to JIS A 5759. Scratchability: Surface property measuring device (HEIDON-14, manufactured by Shinto Chemical Co., Ltd.), load of 200 g / cm ² , 10 reciprocations, steel wool # 0000 ◎: no scratch at all ×: scratch at haze value: Measured using a haze meter (Tokyo Denshoku).

From Table 1, it is clear that the film of the present invention is bright and excellent in transparency, has a large heat ray shielding effect, and is excellent in abrasion resistance.

[0032]

The transparent heat ray-shielding film of the present invention comprises:
It is excellent in transparency and heat ray blocking performance, and a heat ray absorbing compound is contained in a hard coat layer present on the side opposite to the pressure-sensitive adhesive layer. Since the heat ray of light impinges on the hard coat layer after being reflected and absorbed by the sputter layer, the temperature rise of the heat ray-shielding film itself is suppressed, and the heat insulating effect is more effective.
Further, since it has high transparency in the visible light region and is transparent and has excellent scratch resistance, it is most suitable for application to windows of buildings, windows of vehicles, and the like as heat ray shielding films.

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Claims (10)

[Claims] 1. A first film layer having a hard coat layer containing a heat ray absorbing compound, an adhesive layer, a second film layer having a metal sputtering layer, and an adhesive layer are laminated in this order. Heat-shielding film consisting of 2. The heat ray-shielding film according to claim 1, which has a visible light transmittance of 50% or more. 3. A haze value of 3 or less.
The heat ray-shielding film according to any one of the above. 4. The heat ray-shielding film according to claim 1, wherein the heat ray-absorbing compound is a fine particle of a metal oxide having a primary particle diameter of 0.5 μm or less having an infrared absorbing ability. 5. The heat ray shielding film according to claim 4, wherein the metal oxide fine particles are fine particles of anhydrous zinc antimonate. 6. The hard coat layer according to claim 1, wherein the hard coat layer is a cured film layer of a resin composition containing active energy ray-polymerizable (meth) acrylate as a main component. Heat ray shielding film. 7. The heat ray-shielding film according to claim 1, wherein a polymer is contained in the hard coat layer. 8. The heat ray shielding film according to claim 7, wherein the polymer is an acrylic resin, a polyester resin or a butyral resin. 9. The pressure-sensitive adhesive layer according to claim 1, wherein the pressure-sensitive adhesive layer is a pressure-sensitive adhesive layer.
9. The heat ray-shielding film according to any one of items 1 to 8. 10. A window glass having the heat ray-shielding film according to any one of claims 1 to 9 inside.