JP2012121143A - Laminate, and scratch-resistant resin plate obtained by using the same, protective plate for display and protective plate for touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate having higher impact resistance and higher surface hardness, a scratch-resistant resin plate obtained by using the laminate, a protective plate for displays and a protective plate for a touch panel.SOLUTION: The laminate is obtained by laminating a rubber particle-containing methacrylic resin layer (A) on one surface of a polycarbonate resin layer and laminating a rubber particle-containing methacrylic resin layer (B) on the other surface of the polycarbonate resin layer. When t(A) is the thickness of the rubber particle-containing methacrylic resin layer (A), and t(B) is the thickness of the rubber particle-containing methacrylic resin layer (B), the t(A) and the t(B) are in a relationship of t(A)>t(B). The scratch-resistant resin plate is obtained by using the laminate. The protective plate for display and the protective plate for the touch panel are also provided.

Description

  The present invention relates to a laminate in which a methacrylic resin layer is laminated on both surfaces of a polycarbonate resin layer, and a scratch-resistant resin plate, a protective plate for display and a protective plate for touch panel using the same.

  As a scratch-resistant resin plate, Patent Document 1 describes a material excellent in impact resistance and surface hardness and suitable for a display protective plate and a display window protective plate for a portable information terminal. Specifically, a cured body is formed on the surface of each acrylic resin layer using as a substrate a laminate in which both sides of the polycarbonate resin layer contain rubber particles and an acrylic resin layer of the same thickness is laminated. A scratch-resistant resin plate is described in Patent Document 1.

  As the laminate and the scratch-resistant resin plate described above, those having higher impact resistance and surface hardness are desirable.

JP 2010-23444 A

  An object of the present invention is to provide a laminate having higher impact resistance and surface hardness, and a scratch-resistant resin plate, a protective plate for display, and a protective plate for touch panel using the laminate.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a solution means having the following constitution and have completed the present invention.
(1) A methacrylic resin layer (A) containing rubber particles is laminated on one side of a polycarbonate resin layer, and a methacrylic resin layer (B) containing rubber particles is laminated on the other side. ) Is t (A), and the thickness of the methacrylic resin layer (B) is t (B), the t (A) and t (B) are t (A)> t (B) A laminate having the following relationship.
(2) The laminate according to (1), wherein a layer thickness ratio (t (A) / t (B)) between the t (A) and t (B) is 1.2 or more.
(3) The laminate according to (1) or (2), wherein the t (A) is 50 to 200 μm and the t (B) is 10 to 150 μm.
(4) The laminate according to any one of (1) to (3), wherein a total thickness of the t (A) and t (B) is 50% or less of the total thickness.
(5) The laminate according to any one of (1) to (4), wherein the overall thickness is 0.3 to 3 mm.
(6) The laminate according to any one of (1) to (5), wherein the polycarbonate resin layer, the methacrylic resin layer (A), and the methacrylic resin layer (B) are laminated by coextrusion molding.

(7) A scratch-resistant resin plate in which a cured film is formed on the surface of the methacrylic resin layer (A) in the laminate according to any one of (1) to (6).
(8) A scratch-resistant resin plate in which a cured film is formed on the surface of the methacrylic resin layer (B) in the laminate according to any one of (1) to (6).
(9) The scratch-resistant resin plate according to (7), wherein a cured film is formed on the surface of the methacrylic resin layer (B).

(10) A protective plate for a display in which the methacrylic resin layer (A) in the scratch-resistant resin plate according to any one of (7) to (9) is installed toward the viewer side.
(11) A touch panel protective plate in which the methacrylic resin layer (A) in the scratch-resistant resin plate according to any one of (7) to (9) is installed toward the viewer side.

  Since the laminate of the present invention is excellent in impact resistance and surface hardness, these can be effectively protected if a scratch-resistant resin plate using the laminate is used as a protective plate for a display or a touch panel.

  The laminate of the present invention is formed by laminating a methacrylic resin layer (A) containing rubber particles on one side of a polycarbonate resin layer and laminating a methacrylic resin layer (B) containing rubber particles on the other side.

  Examples of the polycarbonate resin constituting the polycarbonate resin layer include those obtained by reacting a dihydric phenol and a carbonylating agent by an interfacial polycondensation method, a melt transesterification method or the like, and a carbonate prepolymer by a solid phase 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 {( -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, and the like, and two or more of them are used as necessary. 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) It is preferable to use a dihydric phenol selected from the group consisting of −3,3,5-trimethylcyclohexane and α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene alone or in combination of two or more. Bisphenol A alone or bisphenol A and 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethyl 1 selected from the group consisting of chlorohexane, bisphenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane and α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene A combined use with two or more dihydric phenols is preferred.

  Examples of the carbonylating agent include carbonyl halides such as phosgene; carbonate esters such as diphenyl carbonate;

  On the other hand, the methacrylic resin layer (A) is made of a methacrylic resin composition (a), and the methacrylic resin layer (B) is made of a methacrylic resin composition (b). These methacrylic resin compositions (a) and (b) both contain a methacrylic resin as a resin component. The methacrylic resin is mainly composed of a methyl methacrylate unit, specifically a methyl methacrylate resin containing usually 50% by weight or more, preferably 70% by weight or more of a methyl methacrylate unit. It may be a methyl methacrylate homopolymer having 100% by weight of methyl units, or may be a copolymer of methyl methacrylate and another monomer copolymerizable with the methyl methacrylate.

  Examples of the other monomer 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, etc. Acrylic acid esters and the like. Examples of styrene and substituted styrenes include halogenated styrenes such as chlorostyrene and bromostyrene, and alkyl styrenes such as vinyltoluene and α-methylstyrene. 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 that can be copolymerized with methyl methacrylate may be used alone or in combination of two or more. In addition, the composition of the methacrylic resin contained in the methacrylic resin compositions (a) and (b) may be the same as or different from each other.

  The methacrylic resin compositions (a) and (b) both contain rubber particles as an essential component. Examples of the rubber particles include graft polymerization of 20 to 95 parts by weight of an ethylenically unsaturated monomer such as an acrylic unsaturated monomer on an acrylic multilayer structure polymer or 5 to 80 parts by weight of a rubbery polymer. And a graft copolymer.

  The acrylic multilayer structure polymer should have an elastomer layer of about 20 to 60% by weight, preferably have a hard layer as the outermost layer, and further have a hard layer as the innermost layer. It may be a thing.

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

  Examples of the lower alkyl group in the lower alkyl acrylate include linear or branched alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl and hexyl groups, Examples of the lower alkoxy group in the lower alkoxyalkyl acrylate include linear or branched alkoxy groups having 1 to 6 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy, pentyloxy, and hexyloxy groups. Can be mentioned. In the case where the monofunctional monomer is used as a main component to form a copolymer, other monofunctional monomers such as styrene and substituted styrene may be copolymerized as a copolymerization component.

  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 is good to be. Examples of the alkyl group having 1 to 4 carbon atoms include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, and t-butyl.

  When the main component is an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms, the copolymer component includes other alkyl methacrylates, alkyl acrylates, styrene, substituted styrenes, acrylonitrile, methacrylonitrile, etc. A monofunctional monomer may be used, or a polyfunctional monomer such as allyl methacrylate may be added to form a crosslinked polymer. Examples of the alkyl group in the alkyl methacrylate include the same linear or branched alkyl groups having 1 to 6 carbon atoms as exemplified for the lower alkyl group described above.

  The above-mentioned acrylic multilayer structure polymer is described in, for example, JP-B-55-27576, JP-A-6-80739, JP-A-49-23292, and the like.

  In the 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. Examples include copolymer rubbers, diene rubbers such as styrene / butadiene copolymer rubbers, acrylic rubbers such as polybutyl acrylate, polypropyl acrylate, and poly-2-ethylhexyl acrylate, and ethylene / propylene / non-conjugated diene rubbers. It is done. Examples of the ethylenic monomer used for graft copolymerization with the rubbery polymer include styrene, acrylonitrile, alkyl (meth) acrylate, and the like. These graft copolymers are described, for example, in JP-A Nos. 55-147514 and 47-9740. In addition, the composition of the rubber particles contained in the methacrylic resin compositions (a) and (b) may be the same or different from each other.

  The content of the rubber particles is preferably 3 to 20% by weight, more preferably 5 to 15% by weight, based on the total of 100% by weight of the methacrylic resin and the rubber particles. If the rubber particle content is too small, the impact resistance tends to decrease, and if the rubber particle content is too large, the surface hardness tends to decrease. In addition, the ratio of the rubber particles contained in the methacrylic resin compositions (a) and (b) may be the same as or different from each other.

  For the polycarbonate resin layer and the methacrylic resin layer (A), (B), for example, a light diffusing agent, a matting agent, a dye, a light stabilizer, an ultraviolet absorber, an antioxidant, a release agent, You may add 1 type (s) or 2 or more types of additives, such as a flame retardant and an antistatic agent.

  The laminate of the present invention is usually in the form of a sheet or film, and is suitably manufactured by laminating and integrating the polycarbonate resin layer, the methacrylic resin layer (A) and the methacrylic resin layer (B) by coextrusion molding. The This co-extrusion molding is performed by melt-kneading the polycarbonate resin, the methacrylic resin composition (a) and the methacrylic resin composition (b) using three uniaxial or biaxial extruders. The lamination can be performed by stacking via a manifold die or the like, and the laminated laminate integrated can be cooled and solidified using, for example, a roll unit.

  When the compositions of the methacrylic resin compositions (a) and (b) are the same, two uniaxial or biaxial extruders are used to convert the polycarbonate resin into one methacrylic resin composition. Both the products (a) and (b) may be melt-kneaded in the other extruder. The laminated body manufactured by coextrusion molding is preferable in terms of easy secondary molding as compared with the laminated body manufactured by bonding using an adhesive or an adhesive.

  Here, a cured film is formed on at least one surface of the laminate to form a scratch-resistant resin plate, and when this scratch-resistant resin plate is used as a protective plate for a display or a touch panel, the scratch-resistant resin plate is It is used so that the methacrylic resin layer (A) faces the front side (viewer side) and the methacrylic resin layer (B) faces the back side (display side / touch panel side). Therefore, among the methacrylic resin layers (A) and (B), the methacrylic resin layer (A) facing the viewer side is easily subjected to external impacts, loads, and the like.

  In the laminate of the present invention, when the thickness of the methacrylic resin layer (A) is t (A) and the thickness of the methacrylic resin layer (B) is t (B), the t (A) and t (B) Are configured to have a relationship of t (A)> t (B). This increases the thickness t (A) of the methacrylic resin layer (A) that is susceptible to external impacts, loads, and the like, and as a result, the impact resistance and surface hardness of the laminate are improved.

  The layer thickness ratio (t (A) / t (B)) between t (A) and t (B) is preferably 1.2 or more, and more preferably 1.5 or more. As a result, the thickness t (A) of the methacrylic resin layer (A) is sufficiently larger than the thickness t (B) of the methacrylic resin layer (B), so that the impact resistance and surface hardness of the laminate can be ensured. improves. Although it does not specifically limit as an upper limit of layer thickness ratio (t (A) / t (B)), Usually, it is about 3.0 or less.

  The t (A) is preferably 50 to 200 μm, more preferably 60 to 120 μm, and the t (B) is preferably 10 to 150 μm, and 30 to 60 μm. Is more preferably 40 to 60 μm, and it is preferable that t (A) and t (B) have a relationship of t (A)> t (B) within this numerical range. On the other hand, if the t (A) and t (B) are too thin, the surface hardness tends to decrease. If the t (A) and t (B) are too large, the heat resistance and resistance of the laminate are reduced. This is not preferable because the impact property may be lowered.

  The total thickness of t (A) and t (B) is preferably 50% or less of the total thickness. When the total thickness of t (A) and t (B) is too large, the thickness of the polycarbonate resin layer is increased, and accordingly, the heat resistance and impact resistance of the laminate may be lowered.

  The thickness of the entire laminate is preferably 0.3 to 3 mm, more preferably 0.4 to 3 mm, and still more preferably 0.5 to 2 mm. The thickness of the entire laminate, the thicknesses t (A) and t (B) of the methacrylic resin layers (A) and (B), and the thickness of the polycarbonate resin layer are all melt-laminated by extrusion from a die. It can be adjusted by the thickness of the body, the interval between the rolls sandwiching the molten laminate, and the like.

  On the other hand, the laminate can be suitably used as a resin substrate in a scratch-resistant resin plate. Next, the scratch-resistant resin plate according to the present invention will be described. The scratch-resistant resin plate of the present invention is formed by forming a cured film on at least one surface of the laminate described above.

  The scratch-resistant resin plate preferably forms a cured film on the surface of the methacrylic resin layer (A) of the laminate, and in addition to the surface, forms a cured film on the surface of the methacrylic resin layer (B). Is more preferable. Thereby, the scratch resistance of the scratch-resistant resin plate can be improved. A cured film may be formed only on the surface of the methacrylic resin layer (B).

Examples of the layer structure of the scratch-resistant resin plate include the following (i) to (iii).
(I) Cured coating / methacrylic resin layer (A) / polycarbonate resin layer / methacrylic resin layer (B)
(Ii) methacrylic resin layer (A) / polycarbonate resin layer / methacrylic resin layer (B) / cured coating (iii) cured coating / methacrylic resin layer (A) / polycarbonate resin layer / methacrylic resin layer (B) / cured coating When the cured film is formed on both surfaces of the laminate, the composition and thickness of the cured film on both surfaces may be the same or different from each other.

  The cured film can be formed by curing a curable coating composition. The curable coating composition contains a curable compound that provides scratch resistance as an essential component, and, if necessary, for example, a curing catalyst, conductive particles, a solvent, a leveling agent, a stabilizer, an antioxidant, a colorant, and the like. It contains.

  Examples of the curable compound include acrylate compounds, urethane acrylate compounds, epoxy acrylate compounds, carboxyl group-modified epoxy acrylate compounds, polyester acrylate compounds, copolymer acrylate compounds, alicyclic epoxy resins, glycidyl ether epoxy resins, vinyl ether compounds, Examples include oxetane compounds. Among these, from the viewpoint of scratch resistance of the cured film, radical polymerization curable compounds such as polyfunctional acrylate compounds, polyfunctional urethane acrylate compounds, and polyfunctional epoxy acrylate compounds, and thermal polymerization systems such as alkoxysilanes and alkylalkoxysilanes. These curable compounds are preferably used. These curable compounds are preferably cured by irradiating energy beams such as electron beam, radiation, and ultraviolet rays, or cured by heating. These curable compounds may be used alone or in combination of a plurality of compounds.

  Particularly preferred curable compounds are those having at least three (meth) acryloyloxy groups in the molecule. Here, the (meth) acryloyloxy group means an acryloyloxy group or a methacryloyloxy group. In addition, in this specification, “(meth)” when referred to as (meth) acrylate, (meth) acrylic acid, etc. Is the meaning.

  Examples of the compound having at least three (meth) acryloyloxy groups in the molecule include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, glycerin tri (meth) acrylate, pentaglycerol tri ( (Meth) acrylate, pentaerythritol tri- or tetra- (meth) acrylate, dipentaerythritol tri-, tetra-, penta- or hexa- (meth) acrylate, tripentaerythritol tetra-, penta-, hexa- or hepta- ( A poly (meth) acrylate of a polyhydric alcohol having a valence of 3 or more, such as (meth) acrylate; a compound having at least two isocyanato groups in the molecule, and a (meth) acrylate having a hydroxyl group with respect to the isocyanato group Urethane (meth) acrylate obtained by reacting at a ratio of hydroxyl groups equal to or higher than moles, and having 3 or more (meth) acryloyloxy groups in the molecule [for example, diisocyanate and pentaerythritol tri (meth) acrylate The hexafunctional urethane (meth) acrylate is obtained by this reaction]; tris (2-hydroxyethyl) isocyanuric acid tri (meth) acrylate and the like. In addition, although the monomer was illustrated here, you may use these monomers as it is, for example, you may use what was in the form of oligomers, such as a dimer and a trimer. 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.

  Commercially available compounds can be used as the compound having at least three (meth) acryloyloxy groups in the molecule. Specific examples thereof include, for example, “NK HARD M101” manufactured by Shin-Nakamura Chemical Co., Ltd. (Urethane acrylate), "NK ester A-TMM-3L" (pentaerythritol triacrylate), "NK ester A-TMMT" (pentaerythritol tetraacrylate), "NK ester A-9530" (dipentaerythritol pentaacrylate) And “NK Ester A-DPH” (dipentaerythritol hexaacrylate), “KAYARAD DPCA” (dipentaerythritol hexaacrylate) manufactured by Nippon Kayaku Co., Ltd., “Nopcocure 200” series manufactured by San Nopco, Dainippon Inn Chemical Industry Co., Ltd. of the (stock) "Uni-Dick" series, and the like.

  When a compound having at least three (meth) acryloyloxy groups in the molecule is used as the curable compound, other curable compounds such as ethylene glycol di (meth) acrylate, diethylene glycol di-dioxide are used as necessary. A compound having two (meth) acryloyloxy groups in the molecule, such as (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate may be used in combination. However, the amount used is usually up to 20 parts by weight per 100 parts by weight of the compound having at least three (meth) acryloyloxy groups in the molecule.

  When the curable coating composition is cured with ultraviolet rays, a photopolymerization initiator is preferably used as a curing catalyst. Examples of the photopolymerization initiator include benzyl, benzophenone and derivatives thereof, thioxanthones, benzyldimethyl ketals, α-hydroxyalkylphenones, hydroxyketones, aminoalkylphenones, acylphosphine oxides, and the like. Depending on the situation, two or more of them can be used. The usage-amount of a photoinitiator is 0.1-5 weight part normally with respect to 100 weight part of sclerosing | hardenable compounds.

  As the photopolymerization initiator, a commercially available product can be used. Specific examples thereof include, for example, “IRGACURE 651”, “IRGACURE 184”, “IRGACURE 500”, and “IRGACURE 500” manufactured by Ciba Specialty Chemicals Co., Ltd. IRGACURE 1000 ”,“ IRGACURE 2959 ”,“ DAROCUR 1173 ”,“ IRGACURE 907 ”,“ IRGACURE 369 ”,“ IRGACURE 1700 ”,“ IRGACURE 1800 ”,“ IRGACURE 819 ”,“ IRGACURE IRGA ” Series and DAROCUR (Darocur) series, both “KAYACURE ITX”, “KAYACURE DETX-S”, “KA” manufactured by Nippon Kayaku Co., Ltd. KAYACURE series such as “YACURE BP-100”, “KAYACUREBMS”, “KAYACURE 2-EAQ”, and the like.

  By containing conductive particles in the curable coating composition, antistatic properties can be imparted to the cured coating. Examples of the conductive particles include antimony-tin composite oxide, tin oxide containing phosphorus, antimony oxide such as antimony pentoxide, antimony-zinc composite oxide, titanium oxide, and indium-tin composite oxide (ITO). Such inorganic particles are preferably used. The conductive particles may be used in the form of a sol having a solid content concentration of about 10 to 30% by weight.

  The particle diameter of the conductive particles is usually 0.5 μm or less, and is preferably 0.001 μm or more in terms of the average particle diameter from the viewpoint of antistatic property and transparency of the cured film, and preferably It is 0.1 μm or less, more preferably 0.05 μm or less. The smaller the average particle diameter of the conductive particles, the lower the haze of the scratch-resistant resin plate and the higher the transparency.

  The usage-amount of the said electroconductive particle is 2-50 weight part normally with respect to 100 weight part of curable compounds, Preferably it is 3-20 weight part. As the amount of the conductive particles used increases, the antistatic property of the cured coating tends to improve. However, when the amount of the conductive particles used excessively decreases the transparency of the cured coating, it is not preferable.

  The conductive particles can be produced by, for example, a gas 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 particles may be 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.

  The curable coating composition may contain a solvent for the purpose of adjusting the viscosity thereof. In particular, when conductive particles are contained, the solvent is preferably contained for dispersion. When preparing a curable coating composition containing conductive particles and a solvent, for example, the conductive particles and the solvent are mixed, the conductive particles are dispersed in the solvent, and then the dispersion is mixed with the curable compound. Alternatively, after mixing the curable compound and the solvent, the conductive particles may be dispersed in the mixed solution.

  The solvent should be one that can dissolve the curable compound and can easily volatilize after coating, and can disperse it when conductive particles are used as a paint component. It is good to be. Examples of such a solvent include alcohols such as diacetone alcohol, methanol, ethanol, isopropyl alcohol, isobutyl alcohol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 1-methoxy-2-propanol, Examples thereof include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and diacetone alcohol, aromatic hydrocarbons such as toluene and xylene, esters such as ethyl acetate and butyl acetate, and water. What is necessary is just to adjust the usage-amount of a solvent suitably according to the property etc. of a curable compound.

  When a leveling agent is contained in the curable coating composition, silicone oil is preferably used. Examples thereof include dimethyl silicone oil, phenylmethyl silicone oil, alkyl / aralkyl-modified silicone oil, fluorosilicone oil, and 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, methacrylic modified silicone oil, amino modified silicone oil, carboxylic acid modified silicone oil, carb Nord modified silicone oil, epoxy modified silicone oil, mercapto modified silicone oil, fluorine modified silicone oil, polyether modified Recone oil, and the like. These leveling agents may be used alone or in combination of two or more. The amount of the leveling agent used is usually 0.01 to 5 parts by weight with respect to 100 parts by weight of the curable compound.

  As the leveling agent, a commercially available product can be used, and specific examples include, for example, “SH200-100cs”, “SH28PA”, “SH29PA”, “SH30PA” manufactured by Toray Dow Corning Silicone Co., Ltd. , “ST83PA”, “ST80PA”, “ST97PA” and “ST86PA”, all of which are “BYK-302”, “BYK-307”, “BYK-320” and “BYK-” manufactured by Big Chemie Japan Co., Ltd. 330 "and the like.

  The curable coating composition thus obtained is applied to at least one surface of the laminate to form a curable coating film, and then cured to form a cured coating film, whereby a scratch-resistant resin plate is obtained. The curable coating may be applied by a coating method such as a bar coating method, a micro gravure coating method, a roll coating method, a flow coating method, a dip coating method, a spin coating method, a die coating method, or a spray coating method. The curable coating film may be cured by irradiation with energy rays, heating, or the like depending on the type of the curable coating composition.

  Examples of energy rays in the case of curing by irradiation with energy rays include ultraviolet rays, electron beams, and radiation, and conditions such as intensity and irradiation time are appropriately selected according to the type of curable coating composition. . Further, in the case of curing by heating, conditions such as temperature and time are appropriately selected according to the type of the curable coating composition, but the heating temperature is generally set so that the resin substrate does not deform. Is preferably 100 ° C. or lower. When the curable coating composition contains a solvent, after application, the solvent may be volatilized and then the curable coating film may be cured, or the solvent may be volatilized and the curable coating film may be cured simultaneously. Also good.

  The thickness of the cured film is preferably 0.5 to 50 μm, more preferably 1 to 20 μm. As the thickness of the cured film is smaller, cracks tend not to occur easily. However, if the thickness is too small, the scratch resistance becomes insufficient, which is not preferable.

  The obtained scratch-resistant resin plate may be subjected to antireflection treatment on its surface by a coating method, a sputtering method, a vacuum deposition method, or the like, if necessary. Alternatively, an antireflection sheet prepared separately may be bonded to one or both sides of the scratch-resistant resin plate to impart an antireflection effect.

  The scratch-resistant resin plate thus obtained is excellent in impact resistance and surface hardness, and thus can be used for various applications. Among them, it is preferably used as a display protective plate and a touch panel protective plate.

  Examples of the type of display to be protected include a CRT display, a liquid crystal display, a plasma display, and an EL display. In addition, display applications to be protected include, for example, a display window of a portable information terminal such as a TV or computer monitor, a mobile phone, a personal handy-phone system (PHS), or a PDA (Personal Digital Assistant), a digital camera, or a handy device. Finder part of a portable video camera, a display window of a portable game machine, and the like.

  Examples of the use of the touch panel to be protected include a car navigation system, a portable information terminal, an operation panel of an industrial machine, a personal computer screen, a touch panel of a portable game machine, and the like.

  In order to produce a display protective plate and a touch panel protective plate from the scratch-resistant resin plate of the present invention, first, if necessary, the scratch-resistant resin plate is subjected to processing such as printing, drilling, and cutting to a required size. do it. Then, if it sets to a display or a touch panel, a display and a touch panel can be protected effectively. At that time, the methacrylic resin layer (A) is placed on the front side (viewer side) and the methacrylic resin layer (B) is placed on the back side (display side / touch panel side).

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

In the examples and comparative examples, the materials used for the production of the laminate and the scratch-resistant resin plate are as follows.
Polycarbonate resin: “Caliber 301-10” manufactured by Sumitomo Dow Co., Ltd. was used.
Methacrylic resin: A pellet of thermoplastic polymer (glass transition temperature 104 ° C.) obtained by bulk polymerization of a monomer composed of 97.8% methyl methacrylate and 2.2% methyl acrylate was used. This glass transition temperature is an extrapolated glass transition start temperature obtained at a heating rate of 10 ° C./min by differential scanning calorimetry according to JIS K7121: 1987.
Rubber particles: The innermost layer is a hard polymer obtained by polymerization of monomers consisting of 93.8% methyl methacrylate, 6% methyl acrylate, and 0.2% allyl methacrylate, and the intermediate layer is acrylic. An elastic polymer obtained by polymerization of a monomer composed of 81% butyl acid, 17% styrene, and 2% allyl methacrylate. The outermost layer is a single polymer composed of 94% methyl methacrylate and 6% methyl acrylate. Rubber particles obtained by emulsion polymerization, which is a hard polymer obtained by polymerization of a monomer, were used.
Curing paint: 25 parts of dipentaerythritol hexaacrylate [“NK Ester A-DPH” manufactured by Shin-Nakamura Chemical Co., Ltd.], photopolymerization initiator [“IRGACURE 184 manufactured by Ciba Specialty Chemicals Co., Ltd.” 2 parts of antimony pentoxide fine particle sol [“ELCOM V-4514” manufactured by Catalytic Chemical Industry Co., Ltd .; solid content concentration 20%, average particle size less than 0.1 μm] 10 parts 1-methoxy-2-propanol A curable coating prepared by mixing 24 parts, 24 parts isobutyl alcohol, and 15 parts diacetone alcohol was used.

[Examples 1 and 2 and Comparative Examples 1 to 3]
(Production of laminate)
First, methacrylic resin compositions (a) and (b) were prepared as materials for forming the methacrylic resin layers (A) and (B). Specifically, a methacrylic resin and rubber particles are mixed at a ratio shown below by a supermixer, melt-kneaded by a twin screw extruder, and a methacrylic resin composition (a) comprising the methacrylic resin and rubber particles. , (B) was obtained as pellets.
Examples 1 and 2 and Comparative Examples 1 and 2: Mixing was carried out at a ratio of 86% methacrylic resin and 14% rubber particles.
Comparative Example 3: Mixing was performed at a ratio of 94% methacrylic resin and 6% rubber particles.

  Next, the polycarbonate resin was melted with a 65 mmφ single screw extruder [Toshiba Machine Co., Ltd.], and the methacrylic resin compositions (a) and (b) were both used with a 45 mm φ single screw extruder [Hitachi Zosen Corporation]. It melted and extruded through a multi-manifold die so that the methacrylic resin layer (A) was laminated on one side of the polycarbonate resin layer and the methacrylic resin layer (B) was laminated on the other side.

  Next, the extruded film-like material is sandwiched between a pair of smooth metal rolls and molded and cooled so as to have the thickness shown in Table 1. A methacrylic resin layer (A) on one side of the polycarbonate resin layer And the laminated body of the 3 layer structure of the thickness shown in Table 1 formed by laminating | stacking a methacryl resin layer (B) on the other surface was obtained.

[Production of scratch-resistant resin plate]
First, the obtained laminate was cut into a size of 100 mm × 80 mm, and a coating film of a curable coating was formed on both sides of the laminate by a dipping method. Next, after drying at room temperature for 1 minute and further drying in a hot air oven at 50 ° C. for 3 minutes to volatilize the solvent, this coating film was subjected to 0.5 J / cm ² using a 120 W high-pressure mercury lamp. It was cured by irradiating with ultraviolet rays to obtain a scratch-resistant resin plate in which a cured film having a thickness of 3.5 μm was formed on both surfaces of the laminate. The composition and thickness of the cured film on both sides of this scratch-resistant resin plate are the same.

[Evaluation]
The resulting scratch-resistant resin plate was evaluated for impact resistance (drop ball strength) and surface hardness (pencil hardness). Each evaluation method is shown below, and the results are shown in Table 1.

<Impact resistance (drop ball strength)>
First, a test piece was cut out from the scratch-resistant resin plate. The test piece had a shape of 85 mm × 65 mm, and the methacrylic resin layer (A) had a falling surface.

  Next, a metal mold having an outer dimension of 85 mm × 65 mm, an inner dimension of 47 mm × 35 mm, and a thickness of 1 mm is placed on the methacrylic resin layer (A) side with an outer dimension of 85 mm × 65 mm, an inner dimension of 47 mm × 35 mm, and a thickness of 2 mm. A metal mold is placed on the methacrylic resin layer (B) side, a test piece is sandwiched between these metal molds, an acrylic plate having a thickness of 85 mm × 65 mm and a thickness of 1 mm is placed under the test piece, and an 85 mm × 65 mm is further placed thereunder The test piece was fixed so that the methacrylic resin layer (A) faced upward.

  Next, a metal ball having a weight of 36 g and a diameter of 20 mmφ was dropped from a height of 100 cm to the center of the test piece. At this time, the case where the specimen breakage did not occur was evaluated as ◯, and the specimen where the specimen breakage occurred was evaluated as x.

<Surface hardness (pencil hardness)>
The measurement surfaces were methacrylic resin layers (A) and (B), and the measurement was performed according to JIS K5600.

  As is clear from Table 1, Examples 1 and 2 are excellent in impact resistance and surface hardness. In contrast, Comparative Examples 1 to 3 in which the thicknesses t (A) and t (B) of the methacrylic resin layers (A) and (B) have a relationship of t (A) <t (B) are high in impact resistance. Inferior results. Moreover, in the comparative example 3, the result inferior to surface hardness was shown. The reason for this is presumed to be that the thicknesses t (A) and t (B) of the methacrylic resin layers (A) and (B) are thin.

Claims (11)

  A methacrylic resin layer (A) containing rubber particles is laminated on one side of a polycarbonate resin layer, and a methacrylic resin layer (B) containing rubber particles is laminated on the other side. The thickness of the methacrylic resin layer (A) Where t (A) and t (B) are t (A)> t (B), where t (A) is greater than t (B), and t (A) is greater than t (B). A laminate characterized by having.   The layered product according to claim 1 whose layer thickness ratio (t (A) / t (B)) of said t (A) and t (B) is 1.2 or more.   The laminate according to claim 1 or 2, wherein the t (A) is 50 to 200 µm and the t (B) is 10 to 150 µm.   The laminate according to any one of claims 1 to 3, wherein a total thickness of the t (A) and t (B) is 50% or less of the total thickness.   The total thickness is 0.3-3 mm, The laminated body in any one of Claims 1-4.   The laminate according to any one of claims 1 to 5, wherein the polycarbonate resin layer, the methacrylic resin layer (A), and the methacrylic resin layer (B) are laminated by coextrusion molding.   The scratch-resistant resin board in which the cured film is formed in the surface of the said methacrylic resin layer (A) in the laminated body in any one of Claims 1-6.   The scratch-resistant resin board in which the cured film is formed in the surface of the said methacrylic resin layer (B) in the laminated body in any one of Claims 1-6.   The scratch-resistant resin plate according to claim 7, wherein a cured film is formed on the surface of the methacrylic resin layer (B).   The protective plate for a display which installs the methacrylic resin layer (A) in the abrasion-resistant resin board in any one of Claims 7-9 toward a viewer side.   The protective plate for touchscreens which installs the methacrylic resin layer (A) in the abrasion-resistant resin board in any one of Claims 7-9 toward a viewer side.