JP2002120321A - Highly durable reflective film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly durable reflective film which has durability even when exposed to both ultraviolet rays and heat rays strongly for a long time, is light in weight, and can correspond to miniaturization. SOLUTION: In the reflective film in which an anchor layer, a silver deposition layer, and a corrosion-proof layer are formed in turn on one side of a base material of a plastic film, and a heat ray cutoff layer is formed on the other side of the base material, an adhesive layer is formed on the corrosion- proof layer, and another base material can be laminated through the adhesive layer to improve the durability further.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly durable reflective film having improved durability and reflectivity, which can be used as a reflector of various lighting equipment, a backlight reflector of a liquid crystal panel, an optical mirror, and the like. It relates to a highly durable reflective film that can be formed.

[0002]

2. Description of the Related Art As a conventional reflector, an aluminum plate or a stainless steel plate is polished, or a plastic film on which a thin metal film such as aluminum or silver is directly deposited is used.

[0003]

However, in the case where a conventional reflector, such as an aluminum plate or a stainless steel plate, is polished or aluminum is directly vapor-deposited on a plastic film, the reflectance is low and the glitter is insufficient. Was.
In addition, the one where silver was directly evaporated on the plastic film,
Although the reflectivity is higher than those obtained by polishing an aluminum plate or a stainless steel plate or those obtained by directly depositing aluminum on a plastic film, the reflectivity has not reached the market demand. Furthermore, there is a problem in durability such as a decrease in adhesion between the plastic film and the silver deposited layer over time, corrosion of the silver deposited layer, change in hue due to light, etc., all of which have satisfactory durability against required physical properties. No reflective film was obtained. Furthermore, in recent years, the life of the cold-cathode tube and the miniaturization of the backlight unit have been advanced, and ultraviolet light and heat rays have been strongly applied to the reflector, and the lighting time has been lengthened. For this reason, attempts have been made to use a plastic film that blocks ultraviolet rays, but even if the durability against ultraviolet rays is improved,
In the case where both ultraviolet rays and heat rays are strongly applied for a long time, most of them are insufficient.

Accordingly, an object of the present invention is to provide a conventional aluminum plate or a stainless steel plate which has been polished, a reflective material in which a metal thin film such as aluminum or silver is directly deposited on a plastic film, or a plastic film having ultraviolet shielding properties such as silver. It is an object of the present invention to provide an excellent high-durability reflective film by solving all of the above-mentioned problems of a reflective material having a metal thin film deposited thereon.

[0005]

According to the present invention, an anchor layer for improving durability and reflectance is formed on one surface of a substrate made of a plastic film, and a silver vapor-deposited layer is formed on the anchor layer. A highly durable reflective film characterized by having a corrosion prevention layer formed thereon and a heat-shielding layer provided on the opposite side of the plastic film base material, and a light-resistant plastic film made of a plastic film base material. The heat-resistant layer is a phthalocyanine-based compound, chromium.
Cobalt complex salt thiol, nickel complex, anthraquinone compound, tin oxide, antimony-tin oxide (AT
O), indium-tin-based oxide (ITO), and a layer containing at least one selected from vanadium oxide.

[0006] With the above configuration, a highly durable reflective film that solves the problems of the conventional reflective film can be produced.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The substrate made of a plastic film in the highly durable reflective film of the present invention is not particularly limited as long as it is highly transparent and has light resistance. For example, acrylic film, polycarbonate film, polyarylate film, polyethylene Naphthalate film, polyethylene terephthalate film, fluorine film and the like are preferable, all of which are easily adhered, easily slipped, antistatic, corona,
A surface treatment such as saponification may be applied, or an ultraviolet absorbent may be kneaded to further improve light resistance, or a resin coated with an ultraviolet absorbent may be coated on the surface. The thickness is not particularly limited, but is usually 6 to
A range of 300 μm is preferred. When the thickness is less than 6 μm, the strength is insufficient, and wrinkles are generated in a process such as resin coating and workability is poor, which is not preferable. On the other hand, if the thickness exceeds 300 μm, the strength is too strong and the winding property in resin coating is poor,
Also, the cost rises, and it is not economical in terms of material cost,
Not practical except in special cases. The thickness of these films is more preferably 12 to 40 μm for the purpose of the miniaturized and lightweight reflector of the present invention. Among these plastic films, polyethylene terephthalate film is the most preferable film in terms of heat resistance, transparency, economy and the like.

The anchor layer employed in the highly durable reflective film of the present invention is not particularly limited as long as it is a resin which is highly transparent, durable and improves the reflectance, and is preferably a thermoplastic resin or a thermosetting resin. , An electron beam-curable resin, a coating composed of any of an ultraviolet-curable resin and the like, for example, an amino resin,
Amino alkyd resin, acrylic resin, acrylic
Styrene copolymer, polyester resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral, urethane resin, urea resin, melamine resin, urea-melamine resin, epoxy resin, fluorine resin, polycarbonate, Nitrocellulose, cellulose acetate,
Resins made of an alkyd resin, a rosin-modified maleic resin, a polyamide resin, or the like alone or a mixture thereof are used. Further, the resin may contain an organic polymer or a copolymer as a main component and additives such as a plasticizer, a stabilizer, and an ultraviolet absorber.

The anchor layer is formed by applying a coating material obtained by diluting the anchor resin with a solvent to one surface of the substrate by a usual coating method such as a gravure coating method, a reverse roll coating method, a roll coating method, or a dip coating method. It is formed by drying (curing in the case of a curable resin). The thickness of the anchor layer is not particularly limited, but is usually appropriately selected from the range of about 0.01 to 3 μm. If the thickness is less than 0.01 μm, the surface of the base material cannot be uniformly coated, and the effect of imparting durability and an improvement in reflectance cannot be sufficiently exerted. On the other hand, if it exceeds 3 μm, the drying speed of the anchor layer becomes slow, which is inefficient and economically undesirable.

The silver deposited layer in the highly durable reflective film of the present invention is formed by a film forming method such as a vacuum deposition method, a sputtering method and an ion plating method. The thickness of the silver deposition layer is not particularly limited, but is usually 20 nm.
It is appropriately selected from the range of about 200 nm. Thickness 2
When the thickness is less than 0 nm, the reflectance is poor, whereas when the thickness exceeds 200 nm, the reflectance is not further improved, and the internal stress of the silver vapor deposition layer increases, and the adhesive strength with the anchor layer tends to decrease,
As the amount of heat received by the substrate during vapor deposition increases, workability deteriorates and the amount of silver used also increases.
Pure silver is adopted as the silver vapor deposition layer in the present invention, but a mixture of other metals or alloyed as far as the reflectivity is not impaired for improving weather resistance (oxidation resistance, sulfuration resistance, etc.) is employed. It may be.

The corrosion preventing layer in the highly durable reflective film of the present invention is not particularly limited, and for example, a coating made of any of a thermoplastic resin, a thermosetting resin, an electron beam curable resin, an ultraviolet curable resin and the like. Used. For example, amino resin, amino alkyd resin, acrylic resin,
Styrene resin, acrylic-styrene copolymer, urea
A resin paint composed of a melamine resin, an epoxy resin, a fluororesin, polycarbonate, nitrile cellulose, cellulose acetate, an alkyd resin, a rosin-modified maleic resin, a polyamide resin, or a mixture thereof is used.

The corrosion-preventing layer is formed by coating a coating obtained by diluting the resin of the corrosion-preventing layer with a solvent on the entire surface of the substrate on which the silver-deposited layer is formed, on the silver-deposited layer side, by a gravure coating method, a roll coating method, a dip coating method It is formed by applying and drying (curing in the case of a curable resin) by a normal coating method such as a method. The thickness of the corrosion prevention layer is not particularly limited, but is usually appropriately selected from the range of about 0.5 to 5 μm. When the thickness is less than 0.5 μm, the surface of the base material and the metal deposition layer cannot be uniformly coated, the effect of forming the corrosion prevention layer cannot be sufficiently exhibited, and the value of forming the corrosion prevention layer is not worthwhile. On the other hand, if the thickness exceeds 5 μm, there is no significant difference in the effect of the corrosion prevention layer, and the drying speed of the corrosion prevention layer becomes slow, which is not efficient. Further, when it is desired to impart concealing properties or heat storage radiating properties to the corrosion prevention layer, a matting agent such as barium sulfate, barium carbonate, calcium carbonate, gypsum, titanium oxide, silicon oxide, alumina white is added to the resin coating for the corrosion prevention layer. A premixed and dispersed body pigment such as silica white, takul, calcium silicate and magnesium carbonate, and metal powder such as aluminum powder, brass powder and copper powder can be used. The size of the particles of the matting agent is not particularly limited, but is preferably in the range of about 0.001 μm to 5 μm which does not hinder the coating.

In the highly durable reflective film of the present invention, an adhesive layer may be provided on the corrosion prevention layer in order to polymerize and bond the highly durable reflective film of the present invention to another substrate. The adhesive layer is not particularly limited, and for example, any of a dry laminating agent, a wet laminating agent, a pressure-sensitive adhesive, a heat sealing agent, a hot melt agent and the like are used. For example, polyester resin, urethane resin, polyvinyl acetate resin, acrylic resin, nitrile rubber, etc. are used. The laminating method is not particularly limited. For example, continuous laminating is preferable in terms of economy and productivity. The thickness of the adhesive layer is usually selected from a range of about 1 to 50 μm. When the thickness is less than 1 μm, a sufficient adhesive effect cannot be obtained. On the other hand, when the thickness exceeds 50 μm, the adhesive layer becomes too thick and the drying speed becomes slow, which is inefficient. Moreover, it is not preferable because the original adhesive strength cannot be obtained and adverse effects such as residual solvent are caused.

The other substrate that can be bonded to the highly durable reflective film of the present invention, which is appropriately employed in the present invention, may be any material capable of imparting a protective property of a silver deposited layer, such as an acrylic film or sheet, or polycarbonate. Plastic film or sheet such as film or sheet, polyarylate film or sheet, polyethylene naphthalate film or sheet, polyethylene terephthalate film or sheet, fluorine film, or plastic film kneaded with titanium oxide, silica, aluminum powder, copper powder, etc. Alternatively, a sheet, a plastic film or sheet coated with a resin into which these are kneaded, or subjected to surface processing such as metal vapor deposition is used. The thickness of the laminated film or sheet is not particularly limited, but is usually selected from the range of 12 to 250 μm. Thickness 12
If it is less than μm, there is a problem in the laminating work surface, which is not preferable. In addition, these other substrates may be provided after providing a concave portion or a convex portion before bonding with the highly durable reflective film of the present invention, and may be formed to have a concave portion or a convex portion after bonding. It is also possible to simultaneously perform the bonding and the molding so as to have the concave portions and the convex portions.

In the present invention, the heat ray blocking layer provided on the opposite surface of the base material made of a plastic film may be a known metal thin film layer or a thin film layer of an inorganic compound alone or a laminate of a known thin film layer formed by vapor deposition or the like. There is no particular limitation on a heat ray blocking layer formed by applying a resin paint containing an agent, but a heat ray blocking layer formed by applying a resin paint containing a heat ray blocking agent is preferable from the viewpoints of economy, heat ray blocking property and the like. The heat ray blocking agent used for the heat ray blocking layer formed by applying a resin paint containing the heat ray blocking agent includes tin oxide,
Inorganic oxides such as antimony-tin oxide (ATO), indium-tin oxide (ITO), and vanadium oxide;
Or other inorganic conductive particles, such as inorganic conductive oxides, conductive sulfides, conductive carbides, conductive nitrides, etc. Organic heat ray blocking agents such as can be used as appropriate, but in terms of excellent transparency, high visible light transmittance and high heat ray blocking performance,
A combination of an organic heat ray-blocking agent and an inorganic heat ray-blocking agent (the ratio of the organic heat ray-blocking agent in the combination is preferably 0.1 to 30% by weight); Those having a primary particle diameter of 0.5 μm or less, more preferably 0.1 μm or less are preferred.

In the highly durable reflective film obtained according to the above-mentioned embodiment, the ultraviolet ray and the heat ray are simultaneously emitted by providing the heat ray blocking layer on the opposite side of the silver vapor deposition layer of the base material made of the plastic film. The durability and the reflectance when strongly irradiated are improved. An anticorrosion layer is provided as protection for silver, and when further protection of the silver deposition layer is required, it is bonded to another substrate via an adhesive layer next to the anticorrosion layer.
Hereinafter, a highly durable reflective film will be described in detail with reference to examples, but is not limited thereto.

[0017]

Example 1 A phthalocyanine-based heat ray blocking agent (organic type) 1 was applied as a heat ray blocking agent to one surface of a substrate made of a polyethylene terephthalate film into which an ultraviolet absorber having a thickness of 25 μm was kneaded.
Parts (parts by weight, the same applies hereinafter) of acrylic resin 3
0 parts of the paint dispersed and applied and dried to a thickness of 2 μm
Was formed. On the opposite side of the heat ray blocking layer, a polyester resin paint is applied and dried to form an anchor layer having a thickness of 1 μm, and silver is vacuum-deposited on the anchor layer to form a silver deposited layer having a thickness of 80 nm. Is formed, and then a melamine-epoxy resin paint (containing titanium oxide) is applied on the entire surface of the silver vapor-deposited layer and dried to form a corrosion prevention layer having a thickness of 1.5 μm. Thus, the highly durable reflective film of the present invention is formed. Obtained.

Example 2 An antimony-tin oxide (ATO) (ATO) having an average particle diameter of 0.1 μm was used as a heat ray blocking agent on one surface of a substrate made of a polyethylene terephthalate film kneaded with a 25 μm-thick ultraviolet absorber. (Inorganic type) was used, and a coating obtained by dispersing this with 30 parts of an acrylic resin was applied and dried to form a heat ray blocking layer having a thickness of 2 μm. On the opposite side of the heat ray blocking layer, a polyester resin paint is applied and dried to form an anchor layer having a thickness of 1 μm, and silver is vacuum-deposited on the anchor layer to form a silver deposited layer having a thickness of 80 nm. Is formed, and then a melamine-epoxy resin paint (containing titanium oxide) is applied to the entire surface on the silver deposition layer and dried to a thickness of 1.5.
A μm corrosion prevention layer was formed to obtain a highly durable reflective film of the present invention.

Example 3 A phthalocyanine-based heat ray blocking agent (organic type) 1 was applied as a heat ray blocking agent to one surface of a substrate made of polyethylene terephthalate film kneaded with a 25 μm-thick ultraviolet absorber.
Parts (parts by weight, hereinafter the same) and 24 parts of an antimony-tin-based oxide (ATO) (inorganic) having an average particle diameter of 0.1 μm, and a coating obtained by dispersing this with 30 parts of an acrylic resin is applied and dried. Thus, a heat ray blocking layer having a thickness of 2 μm was formed. On the opposite surface where the heat ray blocking layer was formed, a polyester resin paint was applied and dried to form an anchor layer having a thickness of 1 μm. Silver was vacuum-deposited on the anchor layer to a thickness of 80 nm.
A melamine-epoxy resin paint (with titanium oxide added) is applied over the entire surface of the silver-deposited layer and dried to form a 1.5 μm-thick corrosion prevention layer. A reflective film was obtained.

Comparative Example 1 A polyester resin-based paint was applied to one side of a substrate made of a polyethylene terephthalate film into which an ultraviolet absorber having a thickness of 25 μm was kneaded, and dried to form an anchor layer having a thickness of 1 μm. Silver is vacuum-deposited on the anchor layer to form a silver-deposited layer having a thickness of 80 nm, and then the entire surface of the silver-deposited layer is coated with melamine-epoxy resin (with titanium oxide added).
Was applied and dried to form a corrosion prevention layer having a thickness of 1.5 μm to obtain a reflection film of the present invention.

<< Evaluation of the Invention >> The reflection films obtained in Examples and Comparative Examples were weathered by a weather meter QUV (DPWL manufactured by Suga Test Instruments Co., Ltd.) from the opposite side of the surface of the substrate made of polyethylene terephthalate film on which the silver deposition layer was formed. -5R)
Was irradiated in an atmosphere at a temperature of 80 ° C. to evaluate the reflectance and the hue after a certain period of time. The reflectance was measured by a spectrophotometer (UV-3100PC) manufactured by Shimadzu Corporation.
Was used to measure the total reflectance, and the Y value was read. The hue was determined by visual inspection.

The initial reflectivity of Example 1 is 93%, the hue is colorless, the reflectivity after irradiation for 300 hours is 93%, the hue is colorless, the reflectivity after irradiation for 1000 hours is 85%, and the hue is It was pale yellow. The initial reflectance in Example 2 was 93%,
The hue is colorless and the reflectance after irradiation for 300 hours is 93.
%, The hue was colorless, the reflectance after irradiation for 1000 hours was 89%, and the hue was pale yellow. In Example 3, the initial reflectance was 93%, the hue was colorless, the reflectance after 300 hours irradiation was 93%, the hue was colorless, the reflectance after 1000 hours irradiation was 93%, and the hue was colorless. Was.

The initial reflectivity of the comparative example is 93%, the hue is colorless, the reflectivity after irradiation for 300 hours is 85%, the hue is light yellow, the reflectivity after irradiation for 1000 hours is 69%, and the hue is It was brown.

[0024]

The highly durable reflective film of the present invention is provided with an anchor layer, a silver deposition layer and a corrosion prevention layer sequentially on one side of a base film made of a plastic film, and blocks heat rays on the opposite side of the base film. By providing a layer, if further protection of the silver deposition layer is required, the protection of the silver deposition layer was further improved by bonding it to another substrate via an adhesive layer on the corrosion prevention layer. Thus, a highly durable reflective film can be provided as a durable and highly durable reflective film as a reflective material used in a place where ultraviolet rays and heat rays are simultaneously and strongly irradiated, which can provide a highly durable reflective film which is effective for weight reduction, miniaturization and long life. It turns out.

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Claims (3)

[Claims] An anchor layer is formed on one side of a substrate made of a plastic film, a silver deposition layer is formed on the anchor layer, and a corrosion prevention layer is further formed on the anchor layer. Highly durable reflective film characterized by having a heat ray blocking layer on the surface. 2. The highly durable reflective film according to claim 1, wherein the substrate made of a plastic film is a light-resistant plastic film. 3. The heat ray blocking layer is composed of a phthalocyanine-based compound, a chromium-cobalt complex thiol, a nickel complex, an anthraquinone-based compound, tin oxide, an antimony-tin-based oxide (ATO), and an indium-tin-based oxide (ITO). 2. A highly durable reflective film according to claim 1, wherein the layer contains at least one selected from the group consisting of vanadium oxide.