JPH10250004A - Film to be stuck on window - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film to be stuck on a window, which is discolored very little by sunbeams and of which the mechanical strength lowers little. SOLUTION: This film is prepared by forming a coat layer containing coat- forming resin of acrylic resin (A) and saturated polyester resin (B) and an ultraviolet absorbent (C) of 5-40 pts.wt. to 100 pts.wt. of the coat-forming resin on one surface of a biaxially oriented polyester film and by forming an adhesive layer on the other surface thereof, and the acrylic resin (A) contains a graft copolymer obtained by polymerizing a methacrylate alkyl ester monomer (b) or a mixture of the monomer (b) as a main constituent and a vinyl monomer (c) copolymerizable with this, in the existence of particles of a crosslinked acrylic ester elastomer (a). The ratio of the elastomer (a) in the acrylic resin is 5-80wt.% and the ratio of the resin B in the coat-forming resin is 1-50wt.%, while a (a)/(B) weight ratio is 1/1-20/1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film for attaching a window, and more particularly, to a film for attaching a window having excellent weather resistance.

[0002]

2. Description of the Related Art Films for attaching windows have been widely used for windows of automobiles and buildings for the purpose of shielding sunlight and preventing glass from scattering, and various methods have been proposed. Generally, a biaxially oriented polyester film having excellent heat resistance, water resistance, chemical resistance, mechanical strength, and the like is used as a base film of a film for window application. However, since the polyester film absorbs ultraviolet rays, it has a drawback that when used outdoors, its mechanical strength is significantly reduced.

As a method for improving the weather resistance of a polyester film, a method of kneading an ultraviolet absorber into the film is known. However, when the ultraviolet light is transmitted through the film, it is gradually absorbed as it advances from the incident side to the opposite side.
Since it is directly affected by ultraviolet rays, the weather resistance of the polyester film cannot be sufficiently improved.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a film for window application in which the discoloration and discoloration due to sunlight are extremely small and the mechanical strength of the film is hardly reduced. To provide.

[0005]

That is, the gist of the present invention is to provide a biaxially oriented polyester film having a film-forming resin mainly composed of an acrylic resin (A) and a saturated polyester resin (B) on one surface thereof. A window-attaching film comprising a coating layer containing 5 to 40 parts by weight of an ultraviolet absorbent (C) based on 100 parts by weight of a film-forming resin, and an adhesive layer formed on the other side. In the presence of the particles of the crosslinked acrylic acid ester-based elastic material (a) as a trunk component, the acrylic resin (A) is used as a branch component to form a methacrylic acid alkyl ester monomer (b) or a methacrylic acid alkyl ester monomer. A graft copolymer obtained by polymerizing a mixture of the monomer (b) and a vinyl monomer (c) copolymerizable with the monomer (b) as a main component,
The proportion of the crosslinked acrylate-based elastic body (a) in the acrylic resin is 5 to 80% by weight, and the proportion of the saturated polyester resin (B) in the film-forming resin is 1 to 5%.
0% by weight, and the (a) / (B) weight ratio is 1/1 to 20
/ 1.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The film for window application of the present invention is a film layer containing a biaxially oriented polyester film, a film-forming resin mainly composed of an acrylic resin (A) and a saturated polyester resin (B), and an ultraviolet absorber (C). And an adhesive layer.

The polyester constituting the biaxially oriented polyester film is a polyester obtained by using an aromatic dicarboxylic acid or an ester thereof and a glycol as main starting materials. For example, 80 mol% or more of the structural unit is ethylene terephthalate. Polyethylene terephthalate (PET), wherein the constituent units are ethylene-2,6-naphthalate in an amount of 80 mol% or more.
2,6-naphthalate (PEN), poly-1,4-cyclohexane dimethylene terephthalate (PCT) in which 80 mol% or more of the structural units are 1,4-cyclohexane dimethylene terephthalate, and the like. In addition,
Examples include polyethylene isophthalate and polybutylene terephthalate.

As the dicarboxylic acid component, in addition to the above dicarboxylic acids, for example, 2,7-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, sebacin Acids, phthalic acid, diphenyl ether dicarboxylic acid, oxymonocarboxylic acid and the like are used.

As the glycol component, in addition to the above-mentioned glycol and dimethanol components, for example, diethylene glycol, propylene glycol, neopentyl glycol, trimethylene glycol, hexamethylene glycol, triethylene glycol, polyethylene glycol, polytetramethylene glycol, and polytetramethylene glycol Alkylene glycol and the like are used.

The above-mentioned polyester may be blended with a small amount of other resins in addition to the homopolymer or the copolymer within a range not departing from the object of the present invention. The polyester film may contain additional particles, precipitated particles, other catalyst residues, and the like as a projection-forming agent in order to impart lubricity. The type, size, and blending amount of such a projection-forming agent are appropriately selected according to the intended slipperiness, transparency, and the like.

The polyester may contain an antistatic agent, a stabilizer, a lubricant, a cross-linking agent, an anti-blocking agent, an antioxidant, an ultraviolet absorber, a light-blocking agent, a coloring agent, and the like, if necessary. Good.

As a method for producing a biaxially oriented polyester film, a conventionally known method can be used. For example,
After the above polyester is melt-extruded into a sheet at 270 to 320 ° C, it is cooled and solidified at 40 to 70 ° C to form an amorphous sheet, and then biaxially stretched sequentially or simultaneously in the longitudinal and transverse directions to form a sheet. A method such as heat treatment at ℃ can be used (for example, see Japanese Patent Publication No. 30-5639). Usually, the stretching temperature is selected from the range of 80 to 140 ° C, and the stretching ratio is selected from the range of 2.5 to 5 times each in the vertical and horizontal directions.

The thickness of the biaxially oriented polyester film is usually 6 to 3 from the viewpoints of workability, mechanical strength and the like.
It is selected from the range of 00 μm, preferably 12 to 200 μm. The biaxially oriented polyester film may be a single layer or a multilayer.

[0014] The acrylic resin (A) is prepared by preparing a crosslinked acrylic acid methacrylate monomer (b) or a methacrylic acid as a branch component in the presence of particles of a crosslinked acrylate-based elastic body (a) as a trunk component. Contains a graft copolymer obtained by polymerizing a mixture of an alkyl ester monomer (b) as a main component and a vinyl monomer (c) copolymerizable with the monomer (b). .

First, the crosslinked acrylic acid ester-based elastic body (a) as a trunk component will be described. The crosslinked acrylic ester-based elastic body (a) is obtained by preparing a mixture of an alkyl acrylate monomer or an alkyl acrylate monomer and a copolymerizable vinyl monomer in the presence of a crosslinkable monomer. Obtained by polymerization.

As the crosslinkable monomer, those commonly used as polyfunctional compounds may be used. For example, ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate , Propylene glycol dimethacrylate, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, dipropylene glycol dimethacrylate, divinylbenzene,
Divinyl adipate, diallyl phthalate, diallyl maleate, allyl acrylate, allyl methacrylate,
Triallyl cyanurate and the like may be mentioned, and these may be used in combination of two or more.

The alkyl acrylate is preferably an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, and may be linear or branched. Specific examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, and the like. Two or more of these may be used in combination.

Examples of the vinyl monomer copolymerizable with the alkyl acrylate include methacrylic acid and alkyl esters of methacrylic acid (the alkyl group having 1 to 1 carbon atoms).
2), dialkyl esters of itaconic acid (the alkyl group has 1 to 10 carbon atoms), acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, styrene, alkyl-substituted styrene, α-methylstyrene and the like.
The mixing amount of these monomers is 40% by weight or less, preferably 25% by weight or less.

As a method for producing the crosslinked acrylic acid ester-based elastic material (a), known polymerization methods can be employed, and among them, an emulsion polymerization method is preferable. As the polymerization initiator, an ordinary free radical generating initiator is used. For example, potassium persulfate, inorganic peroxides such as ammonium persulfate,
Organic hydroperoxides such as cumene hydroperoxide, p-menthane hydroperoxide, ditertiary butyl hydroperoxide, organic peroxides such as benzoyl peroxide, laurylyl peroxide, cumene peroxide, azobisisobutyronitrile And other azo-based polymerization initiators.

Further, the above-mentioned polymerization initiator is combined with a reducing agent such as sodium sulfite, sodium acid sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, glucose, polyamine, hydroxyacetone ascorbate, etc., to form a general redox initiator. Agents can also be used.

Examples of the emulsifier include ordinary surfactants for emulsion polymerization. For example, when the carbon number is 8 to 2
Zero anionic surfactants such as sodium, potassium and ammonium salts of alkyl sulfates and sodium and potassium salts of aliphatic carboxylic acids such as lauric acid, stearic acid and palmitic acid; alkylphenols, aliphatic alcohols and polypropylene Non-ionic surfactants such as reaction products of oxides and ethylene oxide are exemplified. These surfactants may be used in combination of two or more. Further, a cationic surfactant such as a naphthalene formaldehyde condensed sulfonate can be used.

As a method for producing the crosslinked acrylic ester-based elastic material (a), the following emulsion polymerization method can be mentioned.

(1) A method of adding a small amount of a crosslinkable monomer to a mixture of an alkyl acrylate monomer or a mixture of an alkyl acrylate monomer and a copolymerizable vinyl monomer to carry out polymerization.

(2) An alkyl acrylate monomer or a mixture of an alkyl acrylate monomer and a copolymerizable vinyl monomer is further added to the polymer emulsion obtained by the method of (1). To polymerize.

(3) In the method of (2), an alkyl acrylate monomer or a mixture of an alkyl acrylate monomer and a copolymerizable vinyl monomer is added in the presence of a small amount of a crosslinking agent. How to polymerize.

(4) An uncrosslinked elastic body is produced by emulsion polymerization of an alkyl acrylate monomer or a mixture of an alkyl acrylate monomer and a copolymerizable vinyl monomer. Next, in the above-mentioned polymerization system, in the presence of a small amount of a crosslinkable monomer, an alkyl acrylate monomer or a mixture of an alkyl acrylate monomer and a copolymerizable vinyl monomer is added. To polymerize.

Crosslinked acrylic ester-based elastic material (a)
The average particle diameter of the crosslinked elastic emulsion particles is adjusted according to the amount of the surfactant used or the amount of the aqueous medium to be used, so as to be in the range of 0.05 to 0.30 μm. When the average particle size is less than 0.05 μm, the mechanical strength of the obtained acrylic resin tends to be poor. If it exceeds 0.30 μm, stress whitening tends to be remarkable. Regardless of the crosslinked acrylate-based elastic body produced by any of the above methods, it is preferable that the gel content measured by the following method is 80% or more and the swelling degree is 15 or less.

The gel content and the degree of swelling were determined by taking a predetermined amount (W0) of the crosslinked acrylate-based elastic material (a), swelling it after immersion in methyl ethyl ketone for 48 hours at room temperature, and the above sample. Can be calculated by the following equation by measuring the weight (W2) after drying with a vacuum dryer.

[0029]

## EQU1 ## Gel content = (W2 / W0) × 100 (%) Swelling degree = (W1-W2) / W0

The gel content and the degree of swelling may be determined by adjusting the type of the crosslinkable monomer and the amount of the above-mentioned crosslinkable monomer, as well as the polymerization temperature, the type and amount of the initiator used, and the amount Since it is influenced by various polymerization conditions such as a method of adding a polymer and the presence or absence of a molecular weight modifier, it is preferable to appropriately adjust the polymerization. When the gel content is less than 80%, the acrylic resin for forming a film obtained from the elastic body is completely dissolved or excessively swelled in an organic solvent described later, the elastic body particles are deformed, and the mechanical strength, In particular, there is a tendency that the effect of improving impact resistance cannot be sufficiently exhibited. If the degree of swelling is more than 15, stress whitening tends to occur.

Next, the graft copolymer will be described. As the alkyl methacrylate monomer (b) of the branch component to be grafted onto the crosslinked acrylate-based elastic body (a) as the trunk component, one having an alkyl group having 1 to 8 carbon atoms is preferable. However, any of branched chains may be used. For example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, and the like may be used, and two or more of these may be used in combination.

The vinyl monomer (c) copolymerizable with the alkyl methacrylate monomer (b) as a branching component includes acrylic acid and an alkyl ester of acrylic acid (an alkyl group having 1 to 8 carbon atoms). ), Dialkyl esters of itaconic acid (alkyl groups having 1 to 1 carbon atoms)
0), acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, styrene, alkyl-substituted styrene, α-methylstyrene and the like.

It is preferable to select the type and combination of monomers so that the glass transition temperature of the polymer or copolymer obtained from the monomer component to be grafted in the Kraft reaction is 50 ° C. or higher. When the glass transition temperature is lower than 50 ° C., the coating layer has poor blocking resistance.

The graft polymerization may be performed by a solution polymerization method, but is preferably performed by emulsion polymerization. For example, when graft polymerization is performed by an emulsion polymerization method, a monomer to be grafted is added to an emulsion of the crosslinked acrylate-based elastic body (a), and an emulsifier, a polymerization initiator, a molecular weight regulator, Water and the like can be added to select ordinary emulsion polymerization conditions. The proportion of the monomer to be grafted is usually at least 10 parts by weight, preferably at least 30 parts by weight, based on 100 parts by weight of the crosslinked acrylate-based elastic material (a).

The proportion of the crosslinked acrylate-based elastomer (a) contained in the acrylic resin is in the range of 5 to 80% by weight, preferably 10 to 70% by weight. When the proportion of the crosslinked acrylate-based elastic body (a) is less than 5% by weight, the mechanical strength is poor, and when it exceeds 80% by weight, the formed film has poor blocking resistance.

The acrylic resin (A) contains, for example, an alkyl methacrylate monomer (b) or an alkyl methacrylate monomer (b) as a main component in addition to the graft copolymer. A methacrylic resin obtained by polymerizing a mixture of the vinyl monomer (c) copolymerizable with the polymer (b), or a free methacrylic resin formed during the production of a graft copolymer is also included.

Examples of the saturated polyester resin (B) include polyesters obtained by using aromatic dicarboxylic acid or its ester and glycol as main starting materials. Examples of the aromatic dicarboxylic acid include terephthalic acid as a main component, and dibasic acids such as adipic acid, azelaic acid, sebacic acid, phthalic acid, and isophthalic acid, and acid anhydrides thereof. As glycol, ethylene glycol is used as a main component, and in addition,
1,2-propanediol, 1,2-butanediol,
1,3-butanediol, 1,4-butanediol,
1,6-hexanediol, neopentyl glycol,
Trimethylhexanediol and the like. The saturated polyester resin (B) has a weight average molecular weight of 5,000 to 5,000.
Those having a range of 50,000 are preferably used.

The content of the saturated polyester resin (B) is in the range of 1 to 50% by weight, preferably 5 to 30% by weight, based on the weight of the film-forming resin. When the proportion of the saturated polyester resin (B) is less than 1% by weight, the adhesion of the formed film to the polyester film substrate is poor, and when it exceeds 50% by weight, the weather resistance of the film is poor. .

The mixing ratio of the crosslinked acrylate-based elastomer (a) and the saturated polyester-based resin (B) in the acrylic resin is in the range of 1/1 to 20/1 by weight.
When the weight ratio of (a) / (B) is less than 1/1, the mechanical strength is not sufficient, and when it exceeds 20/1, the adhesion to the polyester film substrate is reduced.

As the film forming resin, an acrylic resin (A)
If necessary, an epoxy-based resin, a urethane-based resin, a polycarbonate-based resin, or the like may be mixed in addition to the saturated polyester-based resin (B).

Examples of the ultraviolet absorber (C) include conventionally known ultraviolet absorbers such as salicylic acid compounds, benzotriazole compounds and benzophenone compounds.
Examples include a cyanoacrylate-based compound and an indole-based compound. Among these, a benzophenone-based compound or a benzotriazole-based compound is preferable from the viewpoints of solubility in a film-forming resin, weather resistance, and the like. These are 2
More than one kind may be used in combination.

The content ratio of the ultraviolet absorbent (C) is in the range of 5 to 40 parts by weight, preferably 10 to 25 parts by weight, based on 100 parts by weight of the film-forming resin. When the content is less than 5 parts by weight, the weather resistance of the coating layer is inferior, and when it exceeds 40 parts by weight, a problem of bleeding out of the ultraviolet absorbent occurs.

Film-forming resin and ultraviolet absorber (C)
Is dissolved in an organic solvent or a mixture of one or more of ketones such as methyl ethyl ketone, aromatic hydrocarbons such as benzene, toluene and xylene, and acetates such as methyl acetate and ethyl acetate. After coating on one side of the film, it is dried to form a film layer. Bar coating, reverse roll coating,
Gravure coat, rod coat, air doctor coat,
A conventionally known method such as doctor blade coating can be used.

The thickness of the coating layer is usually in the range of 1 to 10 μm, preferably 1 to 5 μm. If the thickness is less than 1 μm, the weather resistance tends to be poor, and if it exceeds 10 μm, the coating layer tends to peel off. The film-forming resin may contain additives such as an inorganic filler, a silicone-based compound, a heat ray blocking agent, a colorant, and a pigment, if necessary.

Before application, the polyester film may be subjected to a chemical treatment or a discharge treatment in order to improve the coatability or adhesion to the polyester film. Further, an intermediate layer such as an easy-adhesion layer, an antistatic layer, a coloring layer, and a metal deposition layer may be appropriately provided between the polyester film and the coating layer, if necessary.

The pressure-sensitive adhesive layer will be described. Examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer include rubber-based, acrylic-based, and silicone-based adhesives. If necessary, an ultraviolet absorber, a light blocking agent, a coloring agent, and the like may be added to the pressure-sensitive adhesive layer.

As a method for forming the pressure-sensitive adhesive layer, conventionally known methods such as bar coating, reverse roll coating, gravure coating, rod coating, air doctor coating, doctor blade coating, and the like can be used. Since the pressure-sensitive adhesive layer has tackiness, a release film coated with a release agent is usually laminated on the pressure-sensitive adhesive layer.

The thickness of the pressure-sensitive adhesive layer is usually appropriately selected from the range of 3 to 50 μm. Further, between the polyester film and the pressure-sensitive adhesive layer, an easy adhesion layer, an antistatic layer, a coloring layer,
An intermediate layer such as a metal deposition layer may be provided as needed.

When the film for attaching a window of the present invention is attached to a window glass, the film may be attached so that the surface of the coating layer containing the ultraviolet absorbent (C) becomes the sunlight incident surface.

[0050]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. In the examples and comparative examples, “parts” means “parts by weight”. The evaluation method used in the present invention is as follows.

(1) Weather resistance test: UV long life
Fade meter (“FAL-5” manufactured by Suga Test Instruments Co., Ltd.)
Type "), a weather resistance test was performed using a sunshine carborn arc light source.

(2) Light transmittance: using a tungsten lamp light source in a double beam type spectrophotometer (“228” manufactured by Hitachi, Ltd.), and a wavelength of 300 to 900 n.
The light transmittance was continuously measured in the m region, and the light transmittance at 340 nm and 550 nm wavelengths was read from the recording chart.

(3) Tensile breaking elongation: 200 m / min in a room adjusted to a temperature of 23 ° C. and a humidity of 50% RH using a tensile tester (“Intesco Model 2001” manufactured by Intesco Corporation). The tensile elongation at break was determined from the tensile stress-strain curve by the following formula. The sample is
Those having a length of 50 and a width of 150 mm were used. In the formula, L indicates the distance between the chucks at the time of breaking, and L0 indicates the distance between the chucks.

[0054]

## EQU2 ## Tensile elongation at break (%) = [(L−L0) / L0] × 100

(4) Adhesion evaluation: An adhesive tape was applied to the surface of each film on which the coating layer was formed, the adhesive tape was rapidly peeled off, and the peeled area was evaluated. The criteria are as follows.

[0056]

[Table 1] ・ ・ ・: The coating layer does not peel at all.・ ・ ・: The coating layer slightly peels off. Δ: 2/3 or more of the coating layer remains without peeling. X: 2/3 or more of the coating layer is peeled off.

(5) Transparency: The transparency of each film was visually observed. The criteria are as follows.

[0058]

表: No whitened portion is observed on the surface. Δ: A whitened portion is slightly observed on the surface. X: A whitened portion is remarkably observed on the surface.

(6) Graft ratio: The graft ratio in the graft reaction was determined by the following equation. In the formula, (a) is the weight of the crosslinked acrylate-based elastomer, (b) is the weight of the reacted alkyl methacrylate monomer, (b) +
(C) shows the total weight of the reacted alkyl methacrylate monomer and the weight of the copolymerizable vinyl monomer.

[0060]

(Equation 3)

[0061]

(Equation 4)

Production Example 1 (Coating resin solution X) 300 parts of deionized water and 0.3 parts of potassium persulfate were placed in a polymerization vessel.
Parts, disodium phosphate decahydrate 0.5 part and sodium hydrogen phosphate dihydrate 0.3 part were charged and sufficiently replaced with nitrogen. Then, the temperature was raised to 70 ° C., and styrene 1
A mixture consisting of 9.8 parts, 69.3 parts of butyl acrylate, 0.9 parts of allyl methacrylate, and 2.5 parts of sodium dioctylsulfosuccinate (emulsifier) was continuously added over 2 hours.

Immediately after completion of the addition, 1.0 part of t-butylperoxy-2-ethylhexanoate and styrene.
A mixture consisting of 2 parts, 7.7 parts of butyl acrylate and 0.1 part of allyl acrylate was added. After a lapse of 30 minutes from the completion of the addition, the temperature was raised to 90 ° C., and aging was performed for 3 hours to obtain an emulsion of a crosslinked acrylic ester-based elastic material. The average particle size of the obtained crosslinked elastic body is 0.20 μm
The gel content was 97.1% and the degree of swelling was 7.2.

400 parts (solid content: 100 parts) of the obtained crosslinked elastic emulsion was charged into a polymerization vessel, and the mixture was purged with nitrogen while stirring, and then the temperature was raised to 80 ° C. Then, while maintaining the temperature and stirring, 3.0 parts of sodium formaldehyde sulfoxylate in 3.0 parts of deionized water was added.
After adding the solution in which the part was dissolved, methyl methacrylate 3
0.0 part, n-octyl mercaptan 0.03 part, p-
Mentane hydroperoxide (50% solution) 0.1
Five parts of the mixture were added continuously over 30 minutes.

After completion of the addition, the polymerization reaction was further continued for 30 minutes to obtain a graft copolymer emulsion. The obtained graft copolymer emulsion was salted out, separated by filtration, washed with water, and dried according to a conventional method to obtain a graft copolymer powder. The graft ratio was 30%.

To 6.5 parts of the obtained graft copolymer, beads 1 of methacrylic resin (a copolymer having a weight ratio of methyl methacrylate to ethyl methacrylate of 96/4) were added.
1.5 parts and a saturated polyester resin having a molecular weight of 15,000 to 20,000 ("Byron 200" manufactured by Toyobo Co., Ltd.)
2.0 parts were mixed, and the resulting mixture was added to a mixed solvent consisting of 64 parts of methyl ethyl ketone and 16 parts of toluene and dissolved with stirring to prepare a film-forming resin solution X having a solid content of 20% by weight. .

Production Example 2 (Coating resin solution Y) 7.0 parts of the graft copolymer obtained in Production Example 1 were mixed with 10.0 parts of methacrylic resin beads and a molecular weight of 18,000 to 2,000.
3.0 parts of a saturated polyester resin (“Vylon 103” manufactured by Toyobo Co., Ltd.), and the resulting mixture is added to a mixed solvent consisting of 64 parts of methyl ethyl ketone and 16 parts of toluene, while stirring. This was dissolved to prepare a film-forming resin solution Y having a solid content of 20% by weight.

Production Example 3 (Coating resin solution V1) 6.5 parts of the graft copolymer obtained in Production Example 1 were mixed with 13.5 parts of methacrylic resin beads, and the resulting mixture was mixed with 64 parts of methyl ethyl ketone and toluene. It was added to a mixed solvent consisting of 16 parts and dissolved with stirring to prepare a film-forming resin solution (V1) having a solid content of 20% by weight.

Production Example 4 (Coating resin solution V2) 11.5 parts of methacrylic resin beads and 8.5 of saturated polyester resin ("Vylon 103" manufactured by Toyobo Co., Ltd.)
The resulting mixture was added to a mixed solvent consisting of 64 parts of methyl ethyl ketone and 16 parts of toluene and dissolved with stirring to prepare a film-forming resin solution (V2) having a solid content of 20% by weight.

Examples 1 to 5 A coating solution shown in the following Table 3 was applied to one surface of a biaxially oriented polyethylene terephthalate film having a thickness of 50 μm by a roll coater method, dried at 100 ° C., and a coating layer containing an ultraviolet absorbent was formed. Obtained. Next, after forming an adhesive layer having a thickness of 25 μm on the other surface of the biaxially oriented polyethylene terephthalate film, a release film having a thickness of 38 μm was laminated on the adhesive layer to obtain a film for attaching a window.

Comparative Example 1 A film for attaching a window was obtained in the same manner as in Example 1 except that the coating layer was not formed.

Comparative Example 2 A window bonding film was obtained in the same manner as in Example 1, except that a coating layer containing no ultraviolet absorbent was formed.

[0073] Comparative Example 3 UV absorber, 2-1.0 wt (2 ^'- - ^hydroxy-5' tert-butylphenyl) benzotriazole
% Is formed on one side of a biaxially oriented polyethylene terephthalate film having a thickness of 50 μm, and a release film having a thickness of 38 μm is laminated on the adhesive layer to form a film for window application. I got

Comparative Examples 4 to 5 A film for window application was obtained in the same manner as in Example 1 except that a coating layer containing a coating resin solution and an ultraviolet absorber was formed as shown in Table 3 below. Was.

[0075]

[Table 3]

[0076] U1: 2- (2 ^{'- hydroxy-5'} - tert-butylphenyl) benzotriazole U2: 2,4-dihydroxybenzophenone U3: 2-hydroxy-4-methoxybenzophenone

The light transmittance, tensile elongation at break, transparency and the like of each of the above samples were measured. Tables 4 and 5 show the measurement results.

[0078]

[Table 4]

[0079]

[Table 5] H: time ε: tensile elongation at break

[0080]

The film for window application of the present invention has excellent weather resistance, is suitable for external application, and has a high industrial value.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Mutsuo Suga 2nd, Oike, Iwatsuka-cho, Nakamura-ku, Nagoya-shi, Aichi Prefecture Mitsubishi Chemical MKV Corporation Nagoya Office (72) Inventor, Takashi Takazawa 2 Address Mitsubishi Chemical MKV Corporation Nagoya Office (72) Inventor Atsushi Obayashi 2 Mitsubishi Chemical MKV Corporation Nagoya Office

Claims (1)

[Claims] 1. A biaxially oriented polyester film having, on one surface thereof, a film-forming resin mainly composed of an acrylic resin (A) and a saturated polyester-based resin (B), and 5 to 40 parts by weight based on 100 parts by weight of the film-forming resin. A film for window application comprising a coating layer containing a weight part of an ultraviolet absorber (C) and an adhesive layer formed on the other side, wherein the acrylic resin (A) is a main component. In the presence of the particles of the crosslinked acrylate-based elastic body (a) as the main component, the monomer having the alkyl methacrylate monomer (b) or the alkyl methacrylate monomer (b) as a main component as a main component A graft copolymer obtained by polymerizing a mixture of a copolymer (b) and a vinyl monomer (c) copolymerizable with the polymer (b), wherein the crosslinked acrylate-based elastic body ( a) (A) / (B) in which the ratio of the saturated polyester resin (B) in the film-forming resin is 1 to 50% by weight.
A film for attaching a window, wherein the weight ratio is 1/1 to 20/1.