JPS643663B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a laminate in which a high hardness resin layer is provided on one side of a resin film or sheet and an adhesive layer is provided on the other side. Today, synthetic resins are used in a wide range of fields as fibers, films, sheets, and other molded products.
When used in organic glass, various displays, decorative items, etc., the lack of surface hardness is a fatal drawback. That is, because the surface hardness is insufficient, the surface is easily scratched due to contact with other objects, collisions, and stickiness, resulting in a loss of aesthetic appearance and a decrease in transparency. In order to improve this drawback, attempts have been made to form a silicone-based hardened film, a melamine-based hardened film, a hardened film using a polyfunctional (meth)acryloyl group, etc. on the surface of synthetic resin molded products. . These cured coatings are cured by applying the curable resin solution to a synthetic resin molded product, drying it, and then subjecting it to a polymerization reaction or crosslinking reaction, so the curing conditions are generally strict, such as heating to high temperatures or long periods of time at low temperatures. Since this method requires a curing reaction time of several hours, it is not necessarily applicable to all types of products due to limitations depending on the heat resistance of the synthetic resin molded product to be treated and poor productivity. Second, high-hardness films generally have poor adhesion to synthetic resins, which limits the types of synthetic resins that can be used. Thirdly, depending on the type of synthetic resin, even if a high hardness coating is provided, desired hardness and wear resistance may not be achieved. Fourth
The application of curable resin to synthetic resin molded products is usually
Methods such as the dip method are used, and after dipping, it is necessary to remove the material from the dip bath at a very low speed in order to obtain a surface with good smoothness.
It reduces productivity. In order to solve these drawbacks, we conducted extensive research and used a conventional coater to form a high-hardness coating layer on a highly heat-resistant polyalkylene terephthalate film. It has been found that the above-mentioned drawbacks can be improved by a method of applying it to the article to be imparted with scratch resistance, and the present invention has been achieved, which makes it possible to provide a convenient composite membrane for realizing this method. That is, the present invention provides a laminate in which a high hardness resin layer is provided on one side of a film made of a polyalkylene terephthalate resin, and an adhesive layer is provided on the other side, in which the high hardness resin layer is Polymerizing a curable ethylene compound containing a polyfunctional (meth)acryloyloxy compound having 8 or more acryloyloxy groups or/and methacryloyloxy groups or/and its initial polymer in an amount of 50% by weight or more of the total solid content. The present invention relates to a laminate characterized in that it is a polymer layer obtained by. The polyalkylene terephthalate film used in the present invention is a film in which 80% or more (preferably 90% or more) of its constituent components is polyethylene terephthalate, poly1,4-butylene terephthalate, or poly-cyclohexane dimethylene terephthalate, and it cannot be stretched. Although the film may or may not be stretched, it is preferably a film that has been biaxially stretched and then heat set. Thickness is usually 12μ to 500μ, preferably
It is 25μ to 150μ. Prior to forming the high-hardness resin layer, various surface treatments (e.g. corona discharge treatment, flame treatment, etc.) and surface coatings to promote adhesion (titanate-based, polyethyleneimine-based, polyurethane-based, polyester acrylate-based, polyepoxy acrylate-based, etc.) are applied. (polyurethane acrylate type, etc.) may also be used. The thickness of these anchor coat (or primer coat) layers is usually 0.01
g/ ^m2 to 2g/ ^m2 (preferably 0.1 to 0.5g/ ^m2 )
If it is thinner than 0.01 g/m ² , it is difficult to apply it uniformly, and if it is laminated with a thickness of 2 g/m ² or more, even if a cured layer of a polyfunctional (meth)acryloyl group-containing monomer is formed on top of it, the durability will be poor. This is not preferred because it is difficult to obtain a laminate with excellent abrasion and scratch resistance. By applying and laminating an isocyanate group-containing resin composition as an intermediate layer between a high hardness resin layer and a film made of polyalkylene terephthalate resin, the adhesiveness and resistance of the polyfunctional unsaturated monomer cured film ( Since the water resistance and crack resistance are improved, it is possible to select a polyfunctional monomer composition that forms a highly hard film that was previously not applicable due to adhesion and crack resistance. be. A composition whose main component is a polyfunctional unsaturated monomer containing at least 3 or more acryloyloxy groups and/or methacryloyloxy groups in the molecule, or an initial radical reactant thereof, is defined as An unsaturated monomer mixture containing at least 50% by weight of a polyfunctional unsaturated monomer containing at least one (meth)acryloyloxy group based on the total unsaturated monomers, and/or its initial radical reaction product A composition consisting of Examples of polyfunctional unsaturated monomers containing three or more (meth)acryloyloxy groups in the molecule include pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, and trimethylolpropane tri(meth)acrylate. , trimethylolethane tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like. Unsaturated monomers that can be used together with these include unsaturated monomers having two or one (meth)acryloyloxy group in the molecule and other vinyl monomers. Examples of bifunctional monomers include hydrocarbon residues, polyether residues, in which the group bonding between each (meth)acryloyloxy group in one molecule contains 100 or less carbon atoms,
Monomers that are polyester residues are preferred. For example, ethylene glycol di(meth)acrylate,
1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, polyester diol di(meth)acrylate, etc. There is. 2-hydroxymethyl (meth)acrylate as a monofunctional monomer,
Glycidyl (meth)acrylate, (meth)acrylic acid, quaternary ammonium salts of (meth)acrylic esters, etc. can be used. These unsaturated monomers can be applied as they are, but they can also be used after being diluted with an organic solvent. In addition, in order to improve the flatness of the cured coating film, a trace amount of photopolymerization initiator and/or radical initiator is added to the solution of the unsaturated monomer, and the solution is heated at room temperature to 100°C (preferably below 50°C). It is preferable to carry out a radical (polymerization) reaction at temperature (precure). This reaction is carried out under an inert gas atmosphere, and oxygen-containing gas is blown in to stop the reaction before gel is formed. Preferred organic solvents include ketone solvents such as methyl ethyl ketone and ether solvents such as methyl cellosolp. In order to efficiently cure the polyfunctional unsaturated monomer and/or its initial radical reactant of the present invention after coating, a photopolymerization initiator or/and radical initiator is usually added as a curing catalyst.
0.01 to 10% by weight, preferably 0.1% by weight, based on all unsaturated monomers or/and their initial radical reactants
Add up to 5% by weight. Examples of photopolymerization initiators include benzoin (or its ethers) such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether, benzophenone, p-chlorobenzophenone, p-methoxybenzophenone, etc. benzophenone series, naphthoquinone series, anthraquinone series, 3,3',4,4'-benzophenone tetracarboxylic acid derivative series, and sulfur compound series such as tetramethylthiuram disulfide and tetramethylthiuram monosulfide, Examples include. As a radical initiator, 2,
Peroxides such as 4-dichlorobenzoyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butyl peroxybenzoate, methyl ethyl ketone peroxide, di-t-butyl peroxide, azobisisobutyronitrile, azobis-2 , 4-dimethylpaleronitrile and other azo compounds.
Of course, it may be used in combination with amines and the like. The composition may further contain an ultraviolet absorber, a dye, a lubricant, and the like. The composition containing the polyfunctional unsaturated monomer and/or its initial radical reactant of the present invention as a main component can be applied to a polyalkylene terephthalate film using conventional dip methods, spray methods, or A roll coating method such as a gravure coating method, a reverse roll method, a kiss roll method, etc. can be arbitrarily applied. After coating the composition, heating and/or irradiation with actinic rays may be used to cure the composition, with or without drying the solvent. Curing conditions by heating vary depending on the type and concentration of the radical initiator contained in the composition, but
The temperature is usually 70°C to 200°C, preferably 80°C to 180°C, for 10 seconds to 10 minutes, preferably 20 seconds to 2 minutes. Curing by irradiation with active light is usually carried out by irradiating light with a wavelength of 200 mμ to 800 mμ using a commonly used high pressure mercury lamp, low pressure mercury lamp, xenon lamp or the like. Irradiation conditions vary depending on the type and concentration of the photopolymerization initiator contained in the composition and the irradiation atmosphere, but usually a high-pressure mercury lamp is used at 50W/m ²
It can be cured by irradiation for 1 second to 1 minute at an intensity of ~400 W/m ² . The thickness of the cured film is usually 1μ to 20μ, preferably 3μ.
~6μ. If it is less than 1 μm, the abrasion resistance and scratch resistance will be poor, and if it exceeds 20 μm, the cured film will have poor flexibility and cracks will easily occur, which is not preferable. As the adhesive for forming the laminate of the present invention, general adhesives and pressure-sensitive adhesives made from natural resins, synthetic resins, and semi-synthetic resins can be used. For example, there are natural rubber systems, synthetic rubber systems, vinyl polymerization systems, condensation polymerization systems, and thermosetting resin systems. Natural rubber systems include natural rubber, and synthetic rubber systems include butadiene-styrene copolymer systems (SBR), butadiene-acrylonitrile copolymer systems (NBR), chloroprene polymer systems, and isobutylene-isoprene copolymer systems ( butyl rubber). Examples of vinyl polymerization systems include acrylic resin systems, styrene resin systems, vinyl acetate-ethylene copolymer systems, and vinyl chloride-vinyl acetate copolymer systems. Examples of condensation polymerization systems include mainly polyester resin systems. Furthermore, examples of thermosetting resin systems include epoxy resin systems, urethane resin systems, and formalin resin systems. These resins can be used alone or in a mixture of two or more, and when used as adhesives or pressure-sensitive adhesives, they usually have various properties and additives (e.g. tackifying resins, plasticizers, stabilizers, and other fillers). ) are used in combination. Of course, organic solvents, water, dispersants, etc. may also be included. The adhesive layer may be formed using the adhesive or pressure-sensitive adhesive described above using a commonly used technique. In addition, surface treatment of polyalkylene terephthalate film (corona discharge treatment, flame treatment, various anchor coatings) is performed when laminating the adhesive layer.
can be done. In the laminate of the present invention, layers having various functionalities may be included between the polyalkylene terephthalate film and the adhesive layer or high hardness resin layer. For example, it is a layer of metal, metal oxide, or other organic or inorganic material, and is provided with functions such as reflection of light and electromagnetic waves, electrical conductivity, and printability. The laminate of the present invention can be used for instrument covers, window glasses,
It can be effectively used as a surface protective film for mirrors, shop windows, and various display articles by laminating it on the article and heating it or pressing it without heating. The present invention will be further explained below with reference to Examples. In addition, various evaluations in Examples were performed by the following methods. (1) Abrasion resistance (a) Scratch test...on #0000 steel wool
A load of 100 g/cm ² was applied to the film and the film was rubbed back and forth 10 times at a distance of 10 cm to see if it would cause any scratches. (b) Sand drop method: 80 mesh of carborundum (1000 g) is dropped from a height of 635 mm onto the coating surface tilted at an angle of 45 degrees, and the scratches on the surface are measured using a haze meter (manufactured by Toyo Seiki Co., Ltd., Haze Meter S- 3)
Haze (%) was measured. (2) Adhesion to the substrate Cross-cut peel test...Use a knife to make 100 squares with a side of 1 mm that reach the substrate on the coating surface, and apply cellophane adhesive tape (Nichiban Co., Ltd., product name Cellow Tape) on top of them. Evaluation was made based on the number of coatings remaining after application and rapid peeling. (3) Pencil hardness: Measured according to JIS-K-5400. Reference example 1 40 parts of pentaerythritol tetraacrylate and 60 parts of methyl cellosolve in a flask equipped with a stirrer.
1 part and 0.02 part of benzoin ethyl ether were added to make a homogeneous solution. The viscosity of this solution was 4 cps.
Set the system to nitrogen atmosphere and apply 400W while stirring vigorously.
Ultraviolet rays were irradiated for 1 minute using a high-pressure mercury lamp, and after stirring was continued for 18 minutes, air was introduced into the system to stop the reaction. The viscosity at this time was 10 cps. Example 1 The coating composition prepared in Reference Example 1 was mixed with 3% by weight of benzoyl peroxide and 10% by weight of α-cyano-β,β-diphenyl ethyl acrylate based on pentaerythritol tetraacrylate to form a urethane-based coating composition. (Takeda Pharmaceutical Co., Ltd., Takerac A371/Takenate A-10 = 7/3) Anchor coated polyethylene terephthalate biaxially stretched film with a thickness of 50μ was coated with a gravure coater, cured at 160°C for 2 minutes, and thickened. A cured film with a thickness of 8μ and good surface smoothness was formed. This coating had good abrasion resistance, adhesion to the substrate, and weather resistance. A polyester adhesive (Toyobo Co., Ltd.,
Vylon 30S) was applied and heated at 120°C for 5 minutes to remove the solvent in the adhesive. The thickness of the adhesive layer is approx.
It was 4μ. This film was attached to a 3 mm thick polycarbonate plate at 100°C using a pressure roller. Comparative Example 1 To 100 parts of the solution prepared in Reference Example 1, 60 parts of methyl cellosolve, 4 parts of ethyl α-cyano-β,β-diphenyl acrylate, 1.2 parts of benzoin ethyl ether,
Leveling agent (manufactured by Toshiba Silicon Co., Ltd., YF8842)
A coating solution was prepared by adding 0.4 part. The same polycarbonate plate used in Example 1 was immersed in this and heated at 120°C for 3 minutes to remove the methyl cellosolve. After that, both sides were irradiated with ultraviolet rays for 4 minutes from a distance of 10 cm using a 400W high-pressure mercury lamp to form a cured film. I let it happen. The thickness of the coating was 6μ.

[Table] Example 2 An acrylic adhesive (manufactured by Soken Kagaku Co., Ltd.,
Apply SK Dyne 1002) with an applicator and heat at 120℃.
The solvent was removed by heating for 2 minutes. The thickness of this adhesive layer was 12μ. This was painted on a 1 mm thick iron plate with white paint (alkyd paint) and heated at 150℃ for 20 minutes.
Paste it on a surface that has been baked for a minute. This surface looks almost the same as the painted surface, but if you write on it with a water-based felt pen (Majitukuchi Yoke, sold by Yoko Uchida) and leave it on, then wipe it off with a cloth and it will disappear easily, leaving no trace. Also, when I wrote with an oil-based felt pen (Magic Ink R No. 500), it disappeared easily and left no trace when I wiped it off with absorbent cotton soaked in acetone. This surface has good abrasion resistance and the pencil hardness is
It was 4H. On the other hand, when the painted surface was written with a water-based felt pen, it did not completely disappear even if it was wiped with a cloth. When writing with an oil-based felt pen, wiping it off with absorbent cotton soaked in acetone damaged the painted surface and contaminated the entire surface. This painted surface had poor abrasion resistance and a pencil hardness of 2H. Example 3 A scratch-resistant film with a pressure-sensitive adhesive obtained in the same manner as in Example 2 was attached to a 3 mm thick polymethyl methacrylate (PMMA) plate. Comparative Example 3 3% by weight of benzoyl peroxide and 10% by weight of pentaerythritol tetraacrylate were added to the coating composition prepared in Reference Example 1.
α-cyano-β,β-diphenylacrylate ethyl acrylate was mixed, and the same PMMA board used in Example 3 was immersed in the mixture, and then heated at 100°C in air.
It was heated for 60 minutes at (the maximum temperature at which a PMMA board does not undergo thermal deformation), but it did not harden. Comparative Example 4 The coating solution prepared in Comparative Example 1 was applied to one side of a PMMA board, the solvent was removed in hot air at 100°C, and then
The coated surface was cured by irradiating ultraviolet rays for 5 minutes from a distance of 10 cm using a 400W high-pressure mercury lamp. The thickness of this coating was 5μ.

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Claims (1)

[Claims] 1 In a laminate in which a high-hardness resin layer is provided on one side of a film made of polyalkylene terephthalate-based resin and an adhesive layer is provided on the other side, the high-hardness resin layer has three or more molecules in the molecule. A polymer obtained by polymerizing a curable ethylene compound containing a polyfunctional (meth)acryloyloxy compound having an acryloyloxy group or/and a methacryloyloxy group or/and an initial polymerization product thereof in an amount of 50% by weight or more based on the total solid content. A laminate characterized by being a combined layer.