JP2011074227A - Curable coating material for polycarbonate resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable coating material capable of forming, on a surface of a polycarbonate resin substrate, a cured film having excellent adhesion at high temperature and high humidity in addition to good transparency, scratch resistance, and antistatic property and well suppressing generation of crack when stress is applied. <P>SOLUTION: The curable coating material for polycarbonate resin contains a compound (A) having two or more (meth)acryloyl groups per molecule, conductive fine particles (B), and an organic solvent (C), wherein at least a compound (A-1) having two or more (meth)acryloyl groups per molecule and having a structure represented by formula (1) is contained as the compound (A). In the formula, X<SP>1</SP>and X<SP>2</SP>each represent H, 1-6C alkyl, or 3-6C cycloalkyl; X<SP>3</SP>and X<SP>4</SP>each represent a halogen atom, 1-6C alkyl, or 3-6C cycloalkyl; n represents an integer of 0-4; and m represents an integer of 0-4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a curable coating for polycarbonate resin. The present invention also relates to a multilayer resin plate in which a cured coating is formed on at least one surface of a polycarbonate resin substrate with a curable paint, and a display window protection plate of a portable information terminal composed of the multilayer resin plate. is doing.

  Recently, mobile phones such as mobile phones and PHS (Personal Handy-phone System) have become popular with the Internet, and in addition to simple voice transmission functions, mobile information has a function to display text information and image information. Widely used as a terminal. In addition to such portable telephones, PDAs (Personal Digital Assistants) that have Internet functions and e-mail functions in addition to functions such as address books are also widely used.

  These portable information terminals display character information and image information by a method such as liquid crystal or EL (electroluminescence), but the display window is protected by a transparent resin such as methacrylic resin. A plate is used (see Patent Documents 1 and 2). And it has been proposed that the protective plate is provided with a cured film having scratch resistance (hard coat property) by a curable coating in order to prevent the surface from being scratched. The thing containing the poly (meth) acrylate of the above polyhydric alcohol, electroconductive fine particles, and the organic solvent is examined (refer the patent document).

JP 2004-143365 A Japanese Patent Laid-Open No. 2002-6676

  The protective plate described above is required not only to have transparency, scratch resistance and antistatic properties, but also to have sufficient durability under high temperature and high humidity. However, in a multilayer resin plate in which a polycarbonate resin substrate is used as the resin substrate and a cured film is formed on the surface of the resin substrate with the conventional curable paint, the cured film is easily peeled off from the resin substrate under high temperature and high humidity. It was. Furthermore, although the protection plate described above needs to be resistant to externally applied stress, the multilayer resin plate may cause cracks in the cured coating when stress is applied. Therefore, the object of the present invention is to have excellent adhesion under high temperature and high humidity in addition to good transparency, scratch resistance, and antistatic property, and also to generate good cracks when stress is applied. An object of the present invention is to provide a curable coating that can form a suppressed cured film on the surface of a polycarbonate resin substrate.

  As a result of intensive studies, the present inventors have found that the object can be achieved by incorporating a predetermined curable compound into the curable coating material, and have completed the present invention.

  That is, the present invention is a curable paint for polycarbonate resin containing a compound (A) having two or more (meth) acryloyl groups in the molecule, conductive fine particles (B) and an organic solvent (C), The compound (A) has two or more (meth) acryloyl groups in the molecule and has the following formula (1)

(In the formula, X ¹ and X ² each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms, and X ³ and X ⁴ are each a halogen atom, 6 represents an alkyl group or a cycloalkyl group having 3 to 6 carbon atoms, n represents an integer of 0 to 4, and m represents an integer of 0 to 4.)

The curable coating material for polycarbonate resin characterized by including the compound (A-1) which has a structure shown by these at least.

  In addition, according to the present invention, there is provided a multilayer resin plate in which a cured coating is formed on at least one surface of a polycarbonate resin substrate with the curable paint, and a portable information terminal comprising the multilayer resin plate. A display window protection plate is provided.

  According to the curable paint of the present invention, on at least one surface of the polycarbonate resin substrate, in addition to good transparency, scratch resistance and antistatic property, it has excellent adhesion under high temperature and high humidity, and stress It is possible to form a cured film in which the occurrence of cracks when is added is well suppressed. Moreover, a display window can be effectively protected by using the multilayer resin board which has this cured film as a display window protection board of a portable information terminal.

  The curable coating material of the present invention is a curable coating material for polycarbonate resin and contains a compound (A) having two or more (meth) acryloyl groups in the molecule, conductive fine particles (B) and an organic solvent (C). To do. Here, as the polycarbonate resin, for example, a carbonate prepolymer is polymerized by a solid phase transesterification method in addition to those obtained by reacting a dihydric phenol and a carbonylating agent by an interfacial polycondensation method or a melt transesterification method. And those obtained by polymerizing a cyclic carbonate compound by a ring-opening polymerization method.

  Examples of the dihydric phenol include hydroquinone, resorcinol, 4,4′-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, bis {(4-hydroxy-3,5-dimethyl) phenyl} methane, 1,1- Bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A), 2,2-bis { (4-hydroxy-3-methyl) phenyl} propane, 2,2-bis {(4-hydroxy-3,5-dimethyl) phenyl} propane, 2,2-bis {(4-hydroxy-3,5-dibromo) ) Phenyl} propane, 2,2-bis {(3-isopropyl-4-hydroxy) phenyl} propane, 2,2-bis {(4 Hydroxy-3-phenyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) -4 -Methylpentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -4-isopropylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3 5-trimethylcyclohexane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis {(4-hydroxy 3-methyl) phenyl} fluorene, α, α′-bis (4-hydroxyphenyl) -o-diisopropylbenzene, α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene, α, α′-bis (4-hydroxyphenyl) -p-diisopropylbenzene, 1,3-bis (4-hydroxyphenyl) -5,7-dimethyladamantane, 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxydiphenylsulfoxide, 4 , 4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ester, etc., and if necessary, use two or more of them You can also.

  Among them, bisphenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl)- 3-methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) ) -3,3,5-trimethylcyclohexane and α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene are preferably used alone or in combination of two or more. In particular, bisphenol A Of 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and bisphenol A, Use in combination with one or more dihydric phenols selected from 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane and α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene preferable.

  Examples of the carbonylating agent include carbonyl halides such as phosgene, carbonate esters such as diphenyl carbonate, haloformates such as dihaloformates of dihydric phenols, and two or more of them can be used as necessary.

  The curable coating material of the present invention has two or more (meth) acryloyl groups in the molecule as the compound (A) having two or more (meth) acryloyl groups in the molecule, and the following formula (1):

(In the formula, X ¹ and X ² each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms, and X ³ and X ⁴ are each a halogen atom, 6 represents an alkyl group or a cycloalkyl group having 3 to 6 carbon atoms, n represents an integer of 0 to 4, and m represents an integer of 0 to 4.)

It contains at least the compound (A-1) having the structure represented by In this way, the curable paint containing the compound (A-1) having a predetermined structure is used on at least one surface of the polycarbonate resin substrate, in addition to good transparency, scratch resistance and antistatic property, and at high temperature and high humidity. It is possible to form a cured film on the surface of the polycarbonate resin substrate that has excellent adhesion underneath and further suppresses the occurrence of cracks when stress is applied. In addition, the (meth) acryloyloxy group here means an acryloyloxy group or a methacryloyloxy group. In addition, in this specification, “(meth)” when referring to (meth) acrylate, (meth) acrylic acid, and the like has the same meaning.

  In the formula (1), examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an s-butyl group, a t-butyl group, An n-pentyl group and an n-hexyl group can be mentioned. In formula (1), examples of the cycloalkyl group having 3 to 6 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

  Examples of the compound (A-1) include bisphenol AEO-modified diacrylate. Examples of the bisphenol AEO-modified diacrylate include “NK Ester A-BPE-300 (average EO addition mole number 3)” and “NK Ester A-BPE-4” sold by Shin-Nakamura Chemical Co., Ltd. "Average EO addition mole number 4)", "NK ester A-BPE-6 (average EO addition mole number 6)", "NK ester A-BPE-10 (average EO addition mole number 10)", "NK ester A- “BPE-20 (average EO addition mole number 17)”, “NK ester A-BPE-30 (average EO addition mole number 30)” and the like can be suitably used.

  In the present invention, at least the compound (A-1) described above is contained in the curable coating as the compound (A). Here, only compound (A-1) may be used as compound (A), but compound (A-1) is used as a part of compound (A), and compound (A-1) is used as the remainder. Other than these may be used. Examples of compounds other than the compound (A-1) include, for example, a compound (A-2) having two or more (meth) acryloyl groups and an isocyanuric ring in the molecule, the compound (A-1), and General-purpose compounds (A-0) other than the compound (A-2) can be mentioned.

  Examples of the compound (A-2) include ethoxylated isocyanuric acid triacrylate, ε-caprolactone-modified tris- (2-acryloxyethyl) isocyanurate, and the like. As the ethoxylated isocyanuric acid triacrylate, the trade name “NK Ester A-9300” sold by Shin-Nakamura Chemical Co., Ltd. is used as the ε-caprolactone-modified tris- (2-acryloxyethyl) isocyanurate. The product name “NK Ester A-9300-1CL” sold by Shin-Nakamura Chemical Co., Ltd. can be preferably used. These may be used as a mixture.

  Examples of the compound (A-0) include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and neopentyl glycol di (meth) acrylate. Diacrylate of dihydric alcohol; trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, glycerin tri (meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol Tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate 3 such as dipentaerythritol hexa (meth) acrylate, tripentaerythritol tetra (meth) acrylate, tripentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol hepta (meth) acrylate A poly (meth) acrylate of a polyhydric alcohol having a valence or higher; a (meth) acrylate monomer having a hydroxyl group in a compound having at least two isocyanate groups in the molecule, and the hydroxyl group is equimolar or more with respect to the isocyanate group. A urethane (meth) acrylate obtained by reacting at a ratio and having 3 or more (meth) acryloyloxy groups in one molecule [for example, by reaction of diisocyanate with pentaerythritol tri (meth) acrylate , And the like 3-6 functional urethane (meth) acrylate is obtained]. Although the monomers are exemplified here, these monomers may be used as they are, or for example, those in the form of oligomers such as dimers and trimers may be used. Moreover, you may use a monomer and an oligomer together. These (meth) acrylate compounds may be used alone or in combination of two or more.

  Since some compounds (A) are commercially available, such commercially available products can also be used. Examples of commercially available products include “NK Oligo U-6HA” (Shin Nakamura Chemical Co., Ltd., urethane acrylate), “NK Ester A-TMM-3L” [Shin Nakamura Chemical Co., Ltd., Pentaerythritol Tri). Acrylate], “NK Ester A-TMMT” (Shin Nakamura Chemical Co., Ltd., pentaerythritol tetraacrylate), “NK Ester A-9530” (Shin Nakamura Chemical Co., Ltd., dipentaerythritol pentaacrylate), “NK Ester A-DPH” [Shin Nakamura Chemical Co., Ltd., dipentaerythritol hexaacrylate], “KAYARAD DPCA” [Nippon Kayaku Co., Ltd., dipentaerythritol hexaacrylate], “Nopcocure 200” series [ San Nopco Co., Ltd.], “Unidi "And the like series [Dainippon Ink and Chemicals Co., Ltd. product].

  In the present invention, the compound (A-1) and the compound (A-0) are preferably contained in the curable coating as the compound (A), and the compound (A-1), the compound (A-2) and the compound ( More preferably, A-0) is contained in the curable coating.

  When using a compound (A-1) and a compound (A-0) together, the usage-amount of a compound (A-1) is with respect to a total of 100 weight part of a compound (A-1) and a compound (A-0). The amount is preferably 5 to 50 parts by weight, and more preferably 10 to 30 parts by weight.

  When using a compound (A-1), a compound (A-2), and a compound (A-0) together, the usage-amount of a compound (A-1) is the compound (A-1), a compound (A-2), and 5-40 weight part is preferable with respect to a total of 100 weight part of compound (A-0), and 10-30 weight part is more preferable. Moreover, when using together a compound (A-1), a compound (A-2), and a compound (A-0), the usage-amount of a compound (A-2) is the compound (A-1) and the compound (A-2). ) And the compound (A-0) are preferably 5 to 10 parts by weight relative to 100 parts by weight in total.

  The curable paint of the present invention contains conductive fine particles (B) for imparting antistatic properties. Examples of the conductive fine particles (B) include antimony-tin composite oxide, tin oxide containing phosphorus, antimony oxide, antimony-zinc composite oxide, titanium oxide, and indium-tin composite oxide (ITO). Can be mentioned.

  The particle diameter of the conductive fine particles (B) can be appropriately selected depending on the kind of the particles, and usually 0.5 μm or less is used, but the obtained cured coating has antistatic properties and transparency. From the viewpoint, the average particle size is preferably 0.001 μm or more and 0.1 μm or less, and more preferably 0.001 μm or more and 0.05 μm or less. If the average particle size of the conductive fine particles (B) is too large, the haze of the resulting multilayer resin plate increases, and the transparency may be lowered. Moreover, content of electroconductive fine particles (B) is 2-50 weight part normally with respect to 100 weight part of compounds (A), Preferably it is 3-20 weight part. If the amount is too small, the effect of improving the antistatic property becomes poor. Moreover, when there is too much the quantity, there exists a possibility of reducing the transparency of a cured film.

  The conductive fine particles (B) can be produced, for example, by a vapor phase decomposition method, a plasma evaporation method, an alkoxide decomposition method, a coprecipitation method, a hydrothermal method, or the like. The surface of the conductive fine particles (B) is surface-treated with, for example, a nonionic surfactant, a cationic surfactant, an anionic surfactant, a silicon coupling agent, an aluminum coupling agent, or the like. Also good.

  The curable paint contains an organic solvent (C) in order to adjust the viscosity, the thickness of the cured film, and the like. Examples of the organic solvent (C) include methanol, ethanol, 1-propanol, 2-propanol (isopropyl alcohol), 1-butanol, 2-butanol (sec-butyl alcohol), 2-methyl-1-propanol (isobutyl). Alcohol), alcohols such as 2-methyl-2-propanol (tert-butyl alcohol), 2-ethoxyethanol, 2-butoxyethanol, 3-methoxy-1-propanol, 1-methoxy-2-propanol, 1- Alkoxy alcohols such as ethoxy-2-propanol, ketols such as diacetone alcohol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, aromatic hydrocarbons such as toluene and xylene, ethyl acetate, acetic acid Butyl Etc. Such esters.

  The content of the organic solvent (C) in the curable coating is appropriately adjusted according to the material of the substrate, the shape, the coating method, the thickness of the target cured film, etc., but with respect to 100 parts by weight of the compound (A) Usually, it is 20 to 10,000 parts by weight.

  The curable paint may contain additives such as a stabilizer, an antioxidant, a colorant, and a leveling agent as necessary. By containing the leveling agent, the smoothness and scratch resistance of the cured film can be improved.

  As the leveling agent, silicone oil is preferably used. Examples thereof include dimethyl silicone oil, phenylmethyl silicone oil, alkyl / aralkyl modified silicone oil, fluorosilicone oil, polyether modified silicone oil, fatty acid ester modified silicone oil, methyl Hydrogen silicone oil, silanol group-containing silicone oil, alkoxy group-containing silicone oil, phenol group-containing silicone oil, methacryl-modified silicone oil, amino-modified silicone oil, carboxylic acid-modified silicone oil, carbinol-modified silicone oil, epoxy-modified silicone oil, mercapto Examples include modified silicone oil, fluorine-modified silicone oil, and polyether-modified silicone oil. These silicone oils may be used alone or in combination of two or more.

  Since some of these leveling agents are commercially available, such commercially available products can be used. Examples of commercially available leveling agents include “SH200-100cs”, “SH28PA”, “SH29PA”, “SH30PA”, “ST83PA”, “ST80PA”, “ST97PA”, “ST86PA” [all of which are Toray Dow Corning -Sold by Silicone Co., Ltd.]. These leveling agents may be used alone or in combination of two or more.

  Although the usage-amount of a leveling agent is selected suitably, it is about 0.01-5 weight part with respect to 100 weight part of compound (A) normally.

  With the curable coating described above, a cured film having excellent adhesion to the resin substrate even at high temperature and high humidity, in addition to transparency, scratch resistance and antistatic property, on at least one surface of the polycarbonate resin substrate For example, a multilayer resin plate suitable as a display window protection plate of a portable information terminal can be obtained.

  The polycarbonate resin substrate may have a flat surface such as a normal plate (sheet) or film, or may have a curved surface such as a convex lens or a concave lens. . Further, a fine structure such as fine irregularities may be provided on the surface.

  The polycarbonate resin substrate may be colored with a dye or a pigment, if necessary, or may contain an antioxidant, an ultraviolet absorber, or the like. The thickness of the polycarbonate resin substrate is preferably 0.1 mm or more and 3.0 mm or less.

  With the curable paint of the present invention, it is possible to form a cured film on at least one surface of the polycarbonate resin substrate. When a cured film is formed on one surface of the polycarbonate resin substrate, the cured film on the resin substrate It is also possible to form a transparent resin layer other than the polycarbonate resin on the opposite surface. Examples of the transparent resin layer include acrylic resin, styrene-methyl methacrylate copolymer (MS resin), polystyrene, various cycloolefin resins, polymethylpentene, polyester resins, triacetyl cellulose, polysulfone, and polyether. Examples include sulfone, polyolefin resin, polyamide, polyimide, polyvinyl chloride, and the like, and acrylic resin is preferable from the viewpoint of transparency and processability with polycarbonate resin.

  As the acrylic resin, a methacrylic resin is usually used. The methacrylic resin is preferably a methyl methacrylate resin containing a methyl methacrylate unit as a main component, specifically a methyl methacrylate resin containing usually 50% by weight or more, preferably 70% by weight or more of a methyl methacrylate unit. A homopolymer of methyl methacrylate having a unit of 100% by weight may be used, or a copolymer of methyl methacrylate and another monomer may be used.

  Examples of other monomers copolymerizable with methyl methacrylate include ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate. Methacrylic acid esters other than methyl methacrylate, such as methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate Such acrylic acid esters can be mentioned. Further, styrene and substituted styrenes, for example, halogenated styrenes such as chlorostyrene and bromostyrene, alkyl styrenes such as vinyltoluene and α-methylstyrene, and the like are also included. Furthermore, unsaturated acids such as methacrylic acid and acrylic acid, acrylonitrile, methacrylonitrile, maleic anhydride, phenylmaleimide, cyclohexylmaleimide and the like can also be mentioned. These other monomers copolymerizable with methyl methacrylate may be used alone or in combination of two or more.

  The acrylic resin may be used by blending a rubbery polymer. Examples of rubbery polymers include acrylic multilayered polymers and 5 to 80 parts by weight of rubbery polymer with 20 to 95 parts by weight of ethylenically unsaturated monomers such as acrylic unsaturated monomers. Examples thereof include graft copolymers obtained by graft polymerization. The acrylic multilayer structure polymer should have a rubber elastic layer or an elastomer layer contained therein in an amount of about 20 to 60% by weight, and should preferably have a hard layer at the outermost layer. A structure including a hard layer may be used.

  The rubber elastic layer or the elastomer layer is preferably an acrylic polymer layer having a glass transition point (Tg) of less than 25 ° C., and specifically includes lower alkyl acrylate, lower alkyl methacrylate, and lower alkoxyalkyl acrylate. A polymer obtained by crosslinking one or more monofunctional monomers selected from cyanoethyl acrylate, acrylamide, hydroxy lower alkyl acrylate, hydroxy lower alkyl methacrylate, acrylic acid and methacrylic acid with a polyfunctional monomer such as allyl methacrylate. It should be a coalesced layer.

  The hard layer may be an acrylic polymer layer having a Tg of 25 ° C. or more, and specifically, an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms is polymerized alone or as a main component. It should be a thing. When the copolymer is mainly composed of alkyl methacrylate, the copolymer component may be a monofunctional monomer such as other alkyl methacrylate, alkyl acrylate, styrene, substituted styrene, acrylonitrile, or methacrylonitrile. Further, a polyfunctional monomer may be added to form a crosslinked polymer.

  Acrylic multilayer structure polymers are described, for example, in JP-B-55-27576, JP-A-6-80739, JP-A-49-232922, and the like.

  In a graft copolymer obtained by graft polymerization of 20 to 95 parts by weight of an ethylenically unsaturated monomer to 5 to 80 parts by weight of a rubbery polymer, examples of the rubbery polymer include polybutadiene rubber and acrylonitrile / butadiene. Copolymer rubber, diene rubber such as styrene / butadiene copolymer rubber, acrylic rubber such as polybutyl acrylate, polypropyl acrylate, poly-2-ethylhexyl acrylate, ethylene / propylene / non-conjugated diene rubber, etc. It is done. Examples of the ethylenic monomer used for graft copolymerization with the rubbery polymer include styrene, acrylonitrile, and alkyl (meth) acrylate. These graft copolymers are described, for example, in JP-A Nos. 55-147514 and 47-9740.

  When the rubber-like polymer is dispersed in the acrylic resin, the dispersion ratio is usually 3 to 150 parts by weight, preferably 5 to 50 parts by weight with respect to 100 parts by weight of the acrylic resin. If the amount of the rubbery polymer is too large, the surface hardness is lowered, which is not preferable.

  In addition, for example, a light diffusing agent, a matting agent, a dye, a light stabilizer, an ultraviolet absorber, an antioxidant, a release agent, a flame retardant, and an antistatic agent are added to the acrylic resin layer as necessary. One or more agents may be added.

  When the acrylic resin layer described above is formed on one side of the polycarbonate resin substrate, (1) after forming a cured film on one side of the polycarbonate resin substrate, an acrylic resin layer may be formed on the opposite side, (2) After the acrylic resin layer is formed on one surface of the polycarbonate resin substrate, a cured film may be formed on the opposite surface. From the viewpoint of operability, the method (2) is preferable. In this case, the polycarbonate resin layer and the acrylic resin layer are preferably laminated and integrated by coextrusion molding. In this co-extrusion molding, a polycarbonate resin layer material and an acrylic resin layer material are melted and kneaded using two or three uniaxial or biaxial extruders, respectively, and then a feed block die, a multi-manifold die, etc. The molten laminated resin body that is laminated and integrated may be cooled and solidified using, for example, a roll unit to form a laminated resin body.

  When the above-mentioned acrylic resin layer is formed on one side of a polycarbonate resin substrate, the thickness of the entire substrate is usually 0.3 to 3 mm, preferably 0.3 to 2 mm, more preferably 0.4 to 1.5 mm. . Furthermore, the thickness of the acrylic resin layer is 50 to 120 μm, preferably 60 to 110 μm or more, and more preferably 70 to 100 μm. Thus, by setting the thickness of the acrylic resin layer, the base material is more difficult to break and sufficient surface hardness can be obtained.

  In the present invention, the surface of the acrylic resin layer is preferably hard-coated from the viewpoint of scratch resistance required for the display window protection plate. A conventionally well-known method can be employ | adopted for the hard coat process to this acrylic resin layer, For example, the method as described in patent document 1 (Unexamined-Japanese-Patent No. 2004-143365) etc. is employable.

  Formation of the cured film by the curable paint of the present invention, after applying the curable paint to at least one surface of the polycarbonate resin substrate, if necessary, by drying, and then curing the formed coating film, It can be carried out.

  The curable coating can be applied by a method such as a micro gravure coating method, a roll coating method, a dipping coating method, a spin coating method, a die coating method, a cast transfer method, a flow coating method, or a spray coating method.

  The coating film is suitably cured by irradiating with an activation energy ray. Examples of the activation energy rays include electron beams, ultraviolet rays, and visible rays, and are appropriately selected according to the type of curable compound. In the case where ultraviolet rays or visible light is used as the activation energy ray, a photopolymerization initiator is usually used.

  Examples of the photopolymerization initiator include acetophenone, acetophenone benzyl ketal, anthraquinone, 1- (4-isopropylphenyl-2-hydroxy-2-methylpropan-1-one, carbazole, xanthone, 4-chlorobenzophenone, 4,4 '-Diaminobenzophenone, 1,1-dimethoxydeoxybenzoin, 3,3'-dimethyl-4-methoxybenzophenone, thioxanthone, 2,2-dimethoxy-2-phenylacetophenone, 1- (4-dodecylphenyl) -2-hydroxy 2-methylpropan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, triphenylamine, 2,4,6-trimethylbenzoyldiphenylphosphine oxide 1-hydroxy Chlohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, fluorenone, fluorene, benzaldehyde, benzoin ethyl ether, benzoisopropyl ether, benzophenone, Michler ketone, 3-methylacetophenone, 3,3 ′, 4,4′-tetra-tert-butylperoxycarbonylbenzophenone (BTTB), 2- (dimethylamino) -1- [4- (morpholinyl) phenyl] -2- (phenylmethyl) -1-butanone, 4-benzoyl -4'-methyldiphenyl sulfide, benzyl and the like.

  The photopolymerization initiator may be used in combination with a dye sensitizer. Examples of the dye sensitizer include xanthene, thioxanthene, coumarin, and ketocoumarin. Examples of the combination of the photopolymerization initiator and the dye sensitizer include a combination of BTTB and xanthene, a combination of BTTB and thioxanthene, a combination of BTTB and coumarin, and a combination of BTTB and ketocoumarin.

  These photopolymerization initiators can be used alone, or many can be used in combination of two or more. Moreover, since these various photoinitiators are marketed, such a commercial item can be used. Examples of commercially available photopolymerization initiators include “IRGACURE 651”, “IRGACURE 184”, “IRGACURE 500”, “IRGACURE 1000”, “IRGACURE 2959”, “DAROCUR 1173”, “IRGACURE 907”, “IRGACURE 369”. “IRGACURE 1700”, “IRGACURE 1800”, “IRGACURE 819”, “IRGACURE 784” [The above IRGACURE series and DAROCUR series are sold by Ciba Specialty Chemicals Co., Ltd.] "ITX", "KAYACURE DETX-S", "KAYACURE BP-100", "KAYACUREBMS", "K YACURE 2-EAQ "[more KAYACURE (Kayacure) series, sold by Nippon Kayaku Co., Ltd.] and the like.

  The usage-amount of a photoinitiator is 0.1-5 weight part normally with respect to 100 weight part of compounds (A).

  Moreover, the intensity | strength and irradiation time of an activation energy ray are suitably adjusted according to the kind of compound (A), the thickness of the coating film, etc. The activation energy ray may be irradiated in an inert gas atmosphere, and as this inert gas, nitrogen gas, argon gas, or the like can be used.

  The thickness of the cured film thus formed is preferably 1 to 10 μm. If the thickness is too small, the scratch resistance may be insufficient, and if it is too large, cracks are likely to occur when exposed to high temperature and high humidity. The thickness of the cured coating can be adjusted by adjusting the amount per area of the curable coating applied to the surface of the polycarbonate resin substrate and the solid content concentration contained in the curable coating.

  The refractive index (n) of the cured film, the refractive index (ns) of the polycarbonate resin substrate, and the refractive index difference (| n−ns |) are preferably 0.01 or less.

  If the refractive index difference exceeds 0.01, a rainbow pattern may be generated due to light interference between the cured coating and the polycarbonate resin substrate.

  The refractive index of the cured film can be adjusted by appropriately selecting the type and amount of the compound (A) in the curable coating and the type and amount of the conductive fine particles (B).

  Thus, a multilayer resin plate is obtained in which a cured film is formed on at least one surface of the polycarbonate resin substrate with the curable paint. This multilayer resin plate has excellent adhesion under high temperature and high humidity in addition to good transparency, scratch resistance, and antistatic properties, and also suppresses the occurrence of cracks when stress is applied. It is a thing. Therefore, this multilayer resin plate can be suitably used as a display window protection plate of a portable information terminal represented by a mobile phone or the like. It can also be used as various members in fields such as viewfinders for digital cameras and handy video cameras, and display window protection plates for portable game machines.

  In order to produce a display window protection plate for a portable information terminal from the multilayer resin plate of the present invention, first, if necessary, processing such as printing, drilling, etc. may be carried out, and then cut into a required size. Thereafter, it may be set in the display window of the portable information terminal.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these Examples. In the examples, “%” and “part” representing the content or amount used are based on weight unless otherwise specified. The measurement method or evaluation method is as follows.

(Thickness of cured film)
It measured using the film thickness measuring apparatus [F-20 of Filmmetrics.

(Total light transmittance of multi-layer resin plate, haze)
Based on JIS K7105, the total light transmittance (Tt) and haze were measured using "Murakami Color Research Laboratory" HR-100 "".

(Abrasion resistance of cured film)
Steel wool # 0000 was reciprocated 10 times at a load of 500 g / cm ² . At that time, the shape of the steel wool in contact with the surface of the cured coating was a 2 cm square (area 4 cm ² ), and the fibers were arranged in parallel with the sides. The reciprocation distance was 10 cm (one way 5 cm), and the reciprocation was made in the fiber direction at a speed of 1 reciprocation 1 second. After 100 reciprocations, the appearance of scratches on the surface was visually observed and evaluated in the following four stages.
A: No scratch, B: 1-2 scratches, C: 3-10 scratches, D: More than 10 scratches.

(Surface resistance)
In accordance with ASTM-D257, measurement was performed using a surface resistivity meter “Hiresta-UP” manufactured by Mitsubishi Chemical Corporation.

(Adhesion)
A 6.5 cm × 8.5 cm test piece was cut out, immersed in an 80 ° C. hot water bath for 1 hour, then taken out and cooled to room temperature. Next, the adhesion of the cured film on the polycarbonate resin side of the test piece was evaluated. The evaluation was performed by cutting the cured film with a cutter knife at intervals of 1 mm to create a 10 × 10 grid-like cell, and peeling it off with cellophane tape three times in succession. The number of squares remaining without being taken as the number of contacts.

(Cylindrical winding test; presence or absence of cracks when stress is applied)
A 6.5 cm × 8.5 cm test piece was cut out, wound around a glass cylinder having a length of about 30 cm and an outer diameter of 24 mm, with the polycarbonate resin surface facing outward, and held for about 10 seconds. It returned to the flat state from the wound state, and it was confirmed visually whether the hard-coat layer of a polycarbonate resin surface had cracked.

Example 1
(1) Formation of acrylic resin layer on polycarbonate resin substrate Polycarbonate resin (Caliber 301-10 manufactured by Sumitomo Dow Co., Ltd., refractive index 1.585) was melt-kneaded using a 40 mmφ single screw extruder, and acrylic resin (Sumitomo) Chemical Co., Ltd. Sumipex MH) was melt-kneaded using a 20 mmφ single screw extruder, and both layers were made into two layers so that one surface layer was an acrylic resin through a feed block, and then extruded through a T-die, It cooled so that both surfaces might touch the polishing roll completely, and the multilayer resin substrate (a1) by which the acrylic resin layer was laminated | stacked on the single side | surface of the polycarbonate resin substrate was obtained. The total thickness of the resin substrate was 0.5 mm, and the thickness of the acrylic resin layer was 70 μm.

(2) Preparation of curable coating material (b1) for polycarbonate resin Urethane acrylate [“NK Oligo U-6HA” from Shin-Nakamura Chemical Co., Ltd.] 4.8 parts, pentaerythritol tetraacrylate [Shin Nakamura Chemical Co., Ltd.] "NK ester A-TMMT"] 2.0 parts, bisphenol AEO-modified diacrylate [Shin Nakamura Chemical Co., Ltd. "NK ester A-BPE-4"] 2.4 parts, ε-caprolactone-modified tris- (2 -Acryloxyethyl) isocyanurate [Shin Nakamura Chemical Co., Ltd. "NK Ester A-9300-1CL"] 0.6 parts, photoinitiator [Ciba Specialty Chemicals Co., Ltd. IRGACURE184] 0.5 parts, Phosphorus-containing tin oxide fine particles [average particle size 0.1 μm] 10.2 parts, 1-methoxy-2-propanol 75 parts, diace Emissions alcohol 5 parts of silicone oil [Dow Corning Toray Silicone (Ltd.) "SH28PA"] was prepared by mixing 0.01 parts of a polycarbonate resin curing paint (b1).

(3) Composition of curable coating (b2) on the acrylic resin layer side 28 parts of dipentaerythritol hexaacrylate ["NK ester A-DPH" from Shin-Nakamura Chemical Co., Ltd.], photopolymerization initiator [Ciba Specialty IRGACURE 184 from Chemicals Co., Ltd.] 1 part Antimony pentoxide fine particle sol [ELCOM-7514 from Catalytic Chemical Industry Co., Ltd .; solid content concentration 20%] 8 parts, 32 parts 1-methoxy-2-propanol, isobutyl alcohol 32 And 0.045 parts of silicone oil [“SH28PA” of Toray Dow Corning Silicone Co., Ltd.] were mixed to prepare a curable paint (b2) for an acrylic resin layer.

(4) Production of multilayer resin plate The resin substrate (a1) is cut into a size of 10 cm × 8 cm, and the curable paint (b1) is applied to the surface of the resin substrate (a1) on the polycarbonate resin side. After coating using a 20 bar coater, it was dried at room temperature for 1 minute and further dried at 45 ° C. for 10 minutes to form a coating film. Next, this coating film was cured by irradiating with ultraviolet rays of 0.5 J / cm ² using a 120 W high-pressure mercury lamp to form a cured coating on the surface of the resin substrate (a1) on the polycarbonate resin side. The film thickness of the cured film was measured by the above method and found to be 3.6 μm.
Subsequently, the curable paint (b2) was applied to the surface of the resin substrate on the acrylic resin layer side. After coating using a 20 bar coater, it was dried at room temperature for 1 minute and further dried at 45 ° C. for 10 minutes to form a coating film. Next, this coating film was cured by irradiating with ultraviolet rays of 0.5 J / cm ² using a 120 W high-pressure mercury lamp to form a cured coating on the surface of the resin substrate (a1) on the acrylic resin layer side. The thickness of the cured film was measured by the above method and found to be 3.5 μm.
Thus, a multilayer resin plate (P1) was obtained in which a cured coating was formed on the polycarbonate resin side surface and the acrylic resin layer side surface of the resin substrate (a1). The multilayer resin plate (P1) was measured for the total light transmittance (%), haze (%), scratch resistance, surface resistance (Ω / □), adhesion, and occurrence of cracks by the above method. The results are shown in Table 1.

Example 2
(1) Production of multilayer resin plate No. 1 is a bar coder used when applying a curable coating (b1) for polycarbonate resin. 20 to No. Except for changing to 40, the same operation as in Example 1 was performed to obtain a multilayer resin plate (P2). The film thickness of the cured film on the polycarbonate resin side was 6.8 μm, and the film thickness of the cured film on the acrylic resin layer side was 3.4 μm. Further, the total light transmittance (%), haze (%), scratch resistance, surface resistance (Ω / □), adhesion, and occurrence of cracks of this multilayer resin plate (P2) were measured by the above methods. The results are shown in Table 1.

Comparative Example 1
(1) Preparation of curable paint for polycarbonate resin (b3) 9 parts of dipentaerythritol hexaacrylate [“NK ester A-DPH” from Shin-Nakamura Chemical Co., Ltd.], photopolymerization initiator [Ciba Specialty Chemicals Co., Ltd. ) IRGACURE 184] 0.45 parts, phosphorus-containing tin oxide fine particles [average particle diameter 0.1 μm] 10 parts, 1-methoxy-2-propanol 75 parts, diacetone alcohol 5 parts are mixed and cured for polycarbonate resin. A paint (b3) was prepared.

(2) Production of multilayer resin plate A multilayer resin plate (P3) was obtained in the same manner as in Example 1 except that the curable coating for polycarbonate resin was changed from (b1) to (b3). The film thickness of the cured film on the polycarbonate resin side was 3.5 μm, and the film thickness of the cured film on the acrylic resin layer side was 3.6 μm. Further, the total light transmittance (%), haze (%), scratch resistance, surface resistance (Ω / □) and adhesion of the multilayer resin plate (P2) were measured by the above methods. The results are shown in Table 1.

Claims (7)

A curable coating for polycarbonate resin containing a compound (A) having two or more (meth) acryloyl groups in a molecule, conductive fine particles (B) and an organic solvent (C),
The compound (A) has two or more (meth) acryloyl groups in the molecule and has the following formula (1)

(In the formula, X ¹ and X ² each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms, and X ³ and X ⁴ are each a halogen atom, 6 represents an alkyl group or a cycloalkyl group having 3 to 6 carbon atoms, n represents an integer of 0 to 4, and m represents an integer of 0 to 4.)
A curable paint for polycarbonate resin, comprising at least a compound (A-1) having a structure represented by the formula:   Furthermore, the said resin (A) contains the compound (A-2) which has a 2 or more (meth) acryloyl group in a molecule | numerator, and has an isocyanuric ring, The curable coating material for polycarbonate resins of Claim 1.   The polycarbonate resin according to claim 1 or 2, wherein the conductive fine particles (B) are at least one oxide selected from the group consisting of an antimony-tin composite oxide, an antimony-zinc composite oxide, and a phosphorus-containing tin oxide. Curable paint.   The multilayer resin board by which a cured film is formed in the at least one surface of a polycarbonate resin substrate with the curable coating material in any one of Claims 1-3.   A cured film is formed on one surface of the polycarbonate resin substrate by the curable paint according to any one of claims 1 to 3, and an acrylic resin layer is formed on the opposite surface on which the cured film is formed. A multilayer resin plate.   The multilayer resin plate according to claim 5, wherein a hard coat treatment is performed on the acrylic resin layer.   A display window protection plate for a portable information terminal comprising the multilayer resin plate according to claim 4.