JP2016068423A - Weathering-resistant heat-shielding film for outer surface of window - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a weathering-resistant heat-shielding film for an outer surface of a window that has weatherability and has a stable ultraviolet absorption function.SOLUTION: The weathering-resistant heat-shielding film for an outer surface of a window has a UV-curable hard coat layer 3 including a silane-modified benzotriazole and an infrared reflective layer 2. The infrared reflective layer 2 is a layer composed of one or more layers in which a metal is sputtered and the metal is one or more kinds of metals or alloys selected from aluminum, silver, gold, nickel, cobalt and stainless steel; or alternatively titanium dioxide, tin oxide, indium oxide, zinc oxide, tungsten oxide or a metal oxide produced by doping each of the oxides with a dissimilar metal.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a weather-resistant heat-shielding film for a window outer surface, which is attached to the outside of a window for heat insulation.

  In recent years, transparent window films that absorb infrared and ultraviolet light applied to the inside and outside of windows have been used. By sticking such a film to a window, it is possible to provide a heat shielding function or prevent ultraviolet rays from entering while maintaining the function as a window.

  As for the window film stuck on a window, a hard-coat layer is normally formed in the outermost side so that the surface of a window film may not be damaged. Then, an ultraviolet absorbing layer or the like is formed on the inner side (window side) than the hard coat layer. When a window film having such a structure is applied to the outside of the window, ultraviolet rays are first applied to the hard coat layer, so that the hard coat layer is damaged by the ultraviolet rays and deteriorates over time. is there. On the other hand, when a window film is attached to the inside of the window, the hard coat layer is formed on the innermost side and the ultraviolet absorbing layer is formed on the window side, so that the hard coat layer is not exposed to strong ultraviolet rays.

  It is conceivable to use a UV curable hard coat layer in order to solve the problem of the window film to be attached to the outside of the window. For example, Patent Document 1 describes a UV curable hard coat layer in Examples. Since the UV curable hard coat layer has an ultraviolet absorbing function, it is possible to suppress deterioration over time due to ultraviolet rays such as the hard coat layer, the base polyester resin, the sputter layer, and the adhesive layer.

JP 2012-220706 A

  However, when such a UV curable hard coat layer is formed, it is necessary to apply a UV curable resin as a binder to a substrate or the like and to cure by irradiating ultraviolet rays. At that time, curing does not proceed mainly on the side irradiated with ultraviolet rays, and unevenness occurs in curing. Therefore, there is a problem that deterioration with time is easy and the ultraviolet absorption function is not stable. Accordingly, an object of the present invention is to provide a weather-resistant heat-shielding film for a window outer surface having weather resistance and having a stable ultraviolet absorption function.

  In order to achieve the above object, the present inventor has conducted extensive research, and as a result, a compound having a specific structure is included in the UV curable hard coat layer to provide weather resistance and stable ultraviolet absorption. It has been found that a weather-resistant heat-shielding film for a window outer surface having a function can be obtained. That is, this invention is a weather-resistant heat-shielding film for window outer surfaces provided with the UV hardening type hard-coat layer containing the silane modified benzotriazole shown by following formula (1).

  As described above, according to the present invention, it is possible to provide a weather-resistant heat-shielding film for a window outer surface having weather resistance and having a stable ultraviolet absorption function.

2 is a schematic diagram of a cross section of a substrate A. FIG. 1 is a schematic view of a cross section of a weatherproof thermal insulation film for window outer surface according to Example 1. FIG. It is the graph which plotted the value of the color difference delta E after an initial stage, super xenon 500 hours irradiation, and after super xenon 1000 hours irradiation.

(UV curable hard coat layer)
The thermal barrier film according to the present invention has a UV curable hard coat layer. The UV curable hard coat layer contains a silane-modified benzotriazole represented by the formula (1). Hereinafter, it is simply referred to as silane-modified benzotriazole. Silane-modified benzotriazole has a silanol group (Si—OH), and self-polymerizes via this silanol group. Therefore, it is firmly fixed in the binder resin contained in the hard coat layer, and is excellent in weather resistance and ultraviolet absorption function.

  The silane-modified benzotriazole can be obtained, for example, by radical polymerization of a benzotriazole containing a methacryloyl group or an acryloyl group and a silane coupling agent containing an unsaturated group (carbon double bond). The silane-modified benzotriazole is preferably 50 to 150 parts by weight of a silane coupling agent containing an unsaturated group with respect to 100 parts by weight of benzotriazole. When the content of the silane coupling agent is large, the hardness increases, but the UV absorption rate may decrease. When the amount is small, the UV absorption rate increases, but the hardness may decrease.

  As the binder contained in the UV curable hard coat layer, a known UV curable resin can be used. Examples of the UV curable resin include (meth) acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins, and may be (meth) acrylic resins. preferable. The binder is preferably 50 to 500 parts by weight, more preferably 100 to 400 parts by weight, and particularly preferably 200 to 350 parts by weight with respect to 100 parts by weight of the silane-modified benzotriazole.

  The UV curable hard coat layer preferably contains metal particles capable of absorbing infrared rays. Examples of such metal particles include tin oxide, indium oxide, zinc oxide, tungsten oxide, and metal oxides doped with different metals. Examples of the dissimilar metal include antimony, tin, lanthanum, cesium, gallium, and rhodium. The particle size of the metal particles is, for example, 5 to 30 nm. A commercial item can be used for such a metal particle. A metal particle can be 10-30 weight part with respect to 100 weight part of binders, for example.

  In addition, the UV curable hard coat layer may contain, for example, a photoinitiator polymer, silica, and zinc oxide.

(Base material)
The UV curable hard coat layer according to the present invention is preferably a layer in contact with the substrate. The substrate may be a transparent resin film. Examples of the transparent resin film include polyolefin resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyamide resins such as nylon-6 and nylon-66; polystyrene resins; Polyvinyl chloride resin; polyimide resin; polyvinyl alcohol resin; ethylene vinyl alcohol resin; (meth) acrylic resin; (meth) acrylonitrile resin; and cellulose resins such as triacetylcellulose, diacetylcellulose, and cellophane And is preferably a polyester-based resin.

(Infrared reflective layer)
The thermal barrier film according to the present invention preferably has an infrared reflective layer. By including the infrared reflection layer, infrared rays entering from the window can be reflected, and temperature rise due to infrared rays entering from the window can be reduced.

  The infrared reflective layer may be one or more metal sputtered layers obtained by sputtering metal. Examples of the metal include aluminum, silver, gold, nickel, cobalt, and stainless steel, and alloys thereof, titanium dioxide, tin oxide, indium oxide, zinc oxide, and tungsten oxide, and metal oxides doped with different metals. Things. Examples of the metal oxide doped with a different metal include antimony-doped tin oxide, tin-doped indium oxide, and cesium-doped tungsten oxide. The metal sputter layer can be formed by a known method.

(Other layers)
In addition, the heat-shielding film according to the present invention preferably has an adhesive layer so that it can be attached to a window. The adhesive layer can be formed by a known method. Moreover, it is preferable to have a protective layer for protecting the adhesive layer. The protective layer can be formed by a known method.

[Synthesis Example 1]
20 parts by weight of benzotriazole (RUVA93, manufactured by Otsuka Chemical Co., Ltd.) containing a methacryloyl group, 20 parts by weight of vinylsilane (KBE1003, manufactured by Shin-Etsu Chemical Co., Ltd.) as a silane coupling agent, and 60 parts by weight of toluene as a solvent are stirred and dissolved. A solution of 100 parts by weight was prepared. The solution was heated to 120 ° C. with stirring by a stirrer. Further, 1 part by weight of an azo radical initiator (AIBN, manufactured by Otsuka Chemical Co., Ltd.) was added dropwise as a polymerization initiator to obtain a silane-modified benzotriazole according to Synthesis Example 1.

[Example 1]
First, a 50-micrometer-thick PET film (Cosmo Shine, manufactured by Toyobo Co., Ltd.) is used as a base material, and Ag (silver) and TiO ₂ (titania) are used as infrared reflecting layers on the side (back side) where the hard coat layer is not formed. The base material A provided with the infrared reflective layer laminated with a sputter was obtained. A schematic diagram of a cross section of the substrate A is shown in FIG.

  As a binder, 55 parts by weight of pentaerythritol triacrylate (Biscoat # 300, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and 3 parts by weight of a photopolymerization initiator (Irgacure # 819, manufactured by Ciba Japan) are obtained in Synthesis Example 1. 20 parts by weight of the silane-modified benzotriazole and 25 parts by weight of antimony-doped tin oxide particle dispersion (manufactured by Iida Research) were mixed with stirring. The obtained mixed solution was applied to the surface of the substrate A with a Mayer bar # 15 and then cured by irradiating with ultraviolet rays to form a UV curable hard coat layer.

  Next, an acrylic pressure-sensitive adhesive (SK Dyne 1429DT, manufactured by Soken Chemical Co., Ltd.) was applied on the infrared reflective layer with a Mayer bar # 25 to form a pressure-sensitive adhesive layer. Got. The schematic diagram of the cross section of the weather resistant thermal insulation film for window outer surfaces which concerns on Example 1 is shown in FIG.

[Example 2]
As a binder, 55 parts by weight of pentaerythritol triacrylate (Biscoat # 300 manufactured by Osaka Organic Chemical Industry Co., Ltd., 3 parts by weight of photopolymerization initiator (Irgacure # 819, manufactured by Ciba Japan Co., Ltd.), the silane modification obtained in Synthesis Example 1 20 parts by weight of benzotriazole and 25 parts by weight of a cesium tungsten oxide particle dispersion (manufactured by Jetchin Technology Co., Ltd.) were stirred and mixed. Was cured by irradiation to form a UV curable hard coat layer.

  Next, an acrylic pressure-sensitive adhesive (SK Dyne 1429DT, manufactured by Soken Chemical Co., Ltd.) is applied on the infrared reflective layer with a Mayer bar # 25 to form a pressure-sensitive adhesive layer. Got.

Example 3
As a binder, 45 parts by weight of pentaerythritol triacrylate (Biscoat # 300, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and 3 parts by weight of a photopolymerization initiator (Irgacure # 819, manufactured by Ciba Japan) were obtained in Synthesis Example 1. 30 parts by weight of silane-modified benzotriazole and 25 parts by weight of antimony-doped tin oxide particle dispersion (manufactured by Iida Research) were mixed with stirring. The obtained mixed solution was applied to the surface of the substrate A with a Mayer bar # 15 and then cured by irradiating with ultraviolet rays to form a UV curable hard coat layer.

  Next, an acrylic pressure-sensitive adhesive (SK Dyne 1429DT, manufactured by Soken Chemical Co., Ltd.) was applied on the infrared reflective layer with a Mayer bar # 25 to form an adhesive layer. Got.

[Comparative Example 1]
60 parts by weight of a UV curable hard coating (Forse Seed No. 100C, manufactured by China Paint Co., Ltd.) as a binder, 2 parts by weight of benzotriazole (Tinuvin 329FL, manufactured by Ciba Japan) as an UV absorber, antimony-doped tin oxide particle dispersion 25 parts by weight (manufactured by Iida Research Co., Ltd.) and 15 parts by weight of toluene as a solvent for dilution adjustment were mixed with stirring. The obtained mixed solution was applied to the surface of the substrate A with a Mayer bar # 15 and then cured by irradiating with ultraviolet rays to form a UV curable hard coat layer. Other than that was carried out similarly to Example 1, and obtained the weather-resistant heat-insulating film for window outer surfaces which concerns on the comparative example 1.

[Comparative Example 2]
60 parts by weight of UV curable hard coating (Forseed No. 100C, manufactured by China Paint Co., Ltd.) as a binder, 25 parts by weight of a metal oxide particle dispersion (manufactured by Iida Research), and 15 parts by weight of toluene as a solvent were mixed with stirring. . The obtained mixed solution was applied to the surface of the substrate A with a Mayer bar # 15 and then cured by irradiating with ultraviolet rays to form a UV curable hard coat layer. Other than that was carried out similarly to Example 1, and obtained the thermal barrier film for window outer surfaces which concerns on the comparative example 2. FIG.

<Measurement>
UV transmittance:
Each of the weather-resistant heat-shielding films for window outer surfaces according to Examples 1 to 3 and Comparative Examples 1 to 2 is attached to a 3 mm-thick float glass, using a spectrophotometer (V670, manufactured by JASCO Corporation), according to JIS A5759 method, The ultraviolet transmittance was measured. Table 1 shows the initial optical characteristics, and Table 2 shows the results after the accelerated weathering test.
Solar radiation transmittance:
Each of the weather-resistant heat-shielding films for window outer surfaces according to Examples 1 to 3 and Comparative Examples 1 to 2 is attached to a 3 mm-thick float glass, using a spectrophotometer (V670, manufactured by JASCO Corporation), according to JIS A5759 method, The solar radiation transmittance including UV, visible light, and near infrared rays was measured. Table 1 shows the initial optical characteristics, and Table 2 shows the results after the accelerated weathering test.

Color difference:
Using an accelerated weather resistance tester NX75 (manufactured by Suga Test Instruments Co., Ltd.), the color difference delta E after the accelerated weather resistance test was measured using a color difference meter (SE6000, manufactured by Nippon Denshoku Industries Co., Ltd.). Table 1 shows the initial optical characteristics, and Table 2 shows the results after the accelerated weather resistance test (after 1000 hours of super xenon irradiation). Further, FIG. 3 shows a graph plotting the value of the color difference delta E after the initial irradiation after super-xenon 500 hours and after the super-xenon 1000 hours irradiation.

1 Base material 2 Infrared reflective layer 3 Hard coat layer 4 Adhesive layer

Claims (4)

A weather-resistant thermal barrier film for a window outer surface, comprising a UV-curable hard coat layer containing a silane-modified benzotriazole represented by the following formula (1).
(In the formula, n is an integer of 5 to 20.)   Furthermore, the weather-resistant heat-shielding film for window outer surfaces of Claim 1 provided with an infrared reflective layer.   The infrared reflection layer is composed of one or more metal sputtered layers obtained by sputtering a metal, and the metal is one or more metals or alloys selected from the group consisting of aluminum, silver, gold, nickel, cobalt, and stainless steel; The weather-resistant heat-insulating film for an outer surface of a window according to claim 2, which is titanium dioxide, tin oxide, indium oxide, zinc oxide, tungsten oxide, or a metal oxide doped with a different metal. The UV curable hard coat layer further includes metal particles selected from at least one selected from the group consisting of tin oxide, indium oxide, zinc oxide, tungsten oxide, and metal oxides doped with different metals. The weather-resistant heat-insulating film for window outer surface according to any one of claims 1 to 3.