JP2008207467A - Abrasion-resistant resin plate, and displaying window protective plate for portable type information terminal unit using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an abrasion-resistant resin plate which is suitable for a displaying window protective plate of a portable type information terminal unit for which a cured coating of a high abrasion-resistance is installed. <P>SOLUTION: On the surface of the resin board, the cured coating is formed by a curable coating containing a radical polymerizable compound, an alkyl phenon based compound having a hydroxy group or an alkoxy group at the α position, and an alkyl phenon based compound having an amino group at the α position. As the radical polymerizable compound, a compound having at least three (meth)acryloyl oxy-based groups in the molecule is preferably used. As the resin board, a methacrylic resin plate is preferably used. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a scratch-resistant resin plate suitable as a display window protective plate for a portable information terminal, and a display window protective plate for a portable information terminal using the same.

  In recent years, portable telephones such as cellular phones and PHS (Personal Handy-phone System) have become popular with the Internet, and in addition to simple voice transmission functions, portable information terminals have a function to display text information and image information. Has been widely spread as. In addition to such portable telephones, PDAs (Personal Digital Assistants) that have functions such as an address book as well as Internet functions and e-mail functions are also widely used. In this specification, such mobile phones, PHS, PDAs, and the like are collectively referred to as “portable information terminals”. That is, the “portable information terminal” in the present specification is a generic name for a device that has a window (display) for displaying character information, image information, and the like that is large enough to be carried by a person.

  These portable information terminals display character information and image information by a method such as liquid crystal or EL (electroluminescence). The display window is made of a transparent resin as a protective plate. Generally used (see, for example, Patent Documents 1 to 3). In order to prevent the surface from being scratched, it has been proposed that the protective plate be provided with a hardened coating with scratch resistance (hard coat property). Specifically, as the curable coating, In addition, a radical polymerizable compound such as a polyfunctional (meth) acrylate and a compound containing 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator is used (see the patent document).

Japanese Patent Laid-Open No. 2002-6676 JP 2004-143365 A JP 2004-299199 A

  Conventionally proposed display window protection plates for portable information terminals do not necessarily have sufficient scratch resistance of the cured coating. Therefore, the present inventors conducted extensive research to provide a scratch-resistant resin plate suitable as a display window protective plate for a portable information terminal provided with a cured film having high scratch resistance. The present invention has found that a desired scratch-resistant resin plate can be obtained by forming a cured film on the surface using a curable coating containing a radical polymerizable compound and a plurality of predetermined photopolymerization initiators. It came to complete.

  That is, the present invention provides a curable coating comprising a radically polymerizable compound, an alkylphenone compound having a hydroxy group or an alkoxy group at the α-position, and an alkylphenone compound having an amino group at the α-position on the surface of the resin substrate. The present invention provides a scratch-resistant resin plate characterized in that a cured film is formed.

  The present invention also provides a display window protection plate for a portable information terminal made of this scratch-resistant resin plate.

  The scratch-resistant resin plate of the present invention has a cured film having high scratch resistance. By using this scratch-resistant resin plate as a display window protection plate for a portable information terminal, the display window can be effectively used. Can be protected.

  Examples of the resin constituting the substrate of the scratch-resistant resin plate of the present invention include methacrylic resin, polycarbonate resin, polystyrene resin, styrene-acrylonitrile copolymer, and triacetyl cellulose resin. Among these, methacrylic resin is suitable as a resin constituting the substrate because it has high transparency and high rigidity.

  The methacrylic resin is a polymer mainly composed of a methacrylic acid ester. For example, the methacrylic acid ester may be a homopolymer of a methacrylic acid ester, or a methacrylic acid ester of 50% by weight or more and other monomers of 50% by weight or less. And a copolymer thereof. In the case of a copolymer, the proportion of the methacrylic acid ester in all the monomers is preferably 70% by weight or more, and more preferably 90% by weight or more. As the methacrylate ester, alkyl methacrylate is preferably used, and methyl methacrylate is particularly preferably used. Examples of monomers other than methacrylic acid esters include acrylic acid esters such as methyl acrylate and ethyl acrylate, aromatic alkenyl compounds such as styrene and methyl styrene, and unsaturated carboxylic acids such as acrylic acid and methacrylic acid. And alkenyl cyanide compounds such as acrylonitrile and methacrylonitrile.

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

  A scratch-resistant cured film is formed on the surface of the resin substrate. In the present invention, in order to form this cured film, a radically polymerizable compound is included as the curable compound, and the α-position is used as the photopolymerization initiator. A curable paint containing an alkylphenone compound having an alkoxy group or a hydroxy group and an alkylphenone compound having an amino group at the α-position is used. By using such a predetermined curable coating, a cured film having high scratch resistance can be formed. The cured film may be formed on both sides of the resin substrate or on one side.

  As the radically polymerizable compound, a compound having at least one carbon-carbon double bond in the molecule is usually used, and a compound having at least two carbon-carbon double bonds in the molecule is preferably used. More preferably, a compound having at least two (meth) acryloyloxy groups in the molecule, that is, a polyfunctional (meth) acrylate is used, and particularly preferably, at least three (meth) acryloyloxy groups are used in the molecule. A compound having a group is used. In the present specification, the (meth) acryloyloxy group means an acryloyloxy group or a methacryloyloxy group, and “(meth)” in the case of (meth) acrylate, (meth) acrylic acid, etc. is the same. Meaning.

  Examples of polyfunctional (meth) acrylates include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and trimethylolpropane. Tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerin tri (meth) acrylate, dipentaerythritol tri (Meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa ( Data) acrylate, tris [(meth) acryloyloxyethyl] isocyanurate, etc. tripentaerythritol octa (meth) acrylate.

  A phosphazene-based (meth) acrylate compound in which a (meth) acryloyloxy group is introduced into the phosphazene ring of the phosphazene compound; a compound having at least two isocyanato groups in the molecule; a (meth) acryloyloxy group in the molecule; Urethane (meth) acrylate compound obtained by reaction with a compound having a hydroxyl group; reaction between a compound having at least two carboxylic acid halide groups in the molecule and a compound having a (meth) acryloyloxy group and a hydroxyl group in the molecule Polyester (meth) acrylate compounds obtained by: oligomers such as dimers and trimers of the above compounds can also be used. These polyfunctional (meth) acrylates are used alone or in admixture of two or more.

  When an alkylphenone compound having a hydroxy group at the α-position is used as the alkylphenone compound having a hydroxy group or an alkoxy group at the α-position, this compound is represented by α-hydroxyalkylphenone (α-hydroxyalkyl phenyl ketone) or its It can be a substituted derivative, and preferred examples thereof include those represented by the following formula (1).

In formula (1), R ¹ and R ² each represent an alkyl group, an aryl group or an aralkyl group, or R ¹ and R ² together form a ring with the carbon atom to which they are attached. . X ¹ represents an alkyl group, an aryl group, an aralkyl group, an alkoxy group, a hydroxyalkoxy group, an alkylthio group, an amino group or a substituted amino group, a represents a number of 0 to 3, and when a is 2 or more, a plurality of The existing X ¹ may be the same as or different from each other.

When at least one of R ¹ and R ² is an alkyl group, examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, and the like, and the carbon number is usually 1-6. When at least one of R ¹ and R ² is an aryl group, examples thereof include a phenyl group, a tolyl group, a naphthyl group, and the like. The carbon number is usually 6 to 10. When at least one of R ¹ and R ² is an aralkyl group, examples thereof include a benzyl group, a phenethyl group, a tolylmethyl group, and the like, and the carbon number is usually 7 to 10. When R ¹ and R ² are combined to form a ring with the carbon atom to which they are bonded, examples of this ring include a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, and the like. The carbon number is usually 5-10.

When X ¹ is an alkyl group, examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, and the carbon number is usually 1-6. When X ¹ is an aryl group, examples thereof include a phenyl group, a tolyl group, a naphthyl group, and the carbon number is usually 6 to 10. When X ¹ is an aralkyl group, examples thereof include a benzyl group, a phenethyl group, a tolylmethyl group, and the like, and the number of carbon atoms is usually 7 to 10. When X ¹ is an alkoxy group, examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group and the like, and the number of carbon atoms is usually 1-6. When X ¹ is a hydroxyalkoxy group, examples thereof include a hydroxymethoxy group, a hydroxyethoxy group, a hydroxypropoxy group, a hydroxybutoxy group, and the like. The carbon number is usually 1-6. When X ¹ is an alkylthio group, examples thereof include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, and the like. The carbon number is usually 1-6. When X ¹ is a substituted amino group, examples thereof include monoalkylamino groups such as monomethylamino group, monoethylamino group, monopropylamino group, monobutylamino group, dimethylamino group, diethylamino group, dipropyl group. In addition to dialkylamino groups such as amino group and dibutylamino group, cyclic amino groups such as pyrrolidino group, piperidino group and morpholino group can be mentioned, and the number of rings is usually 5-10.

Examples of commercially available compounds represented by the formula (1) include “IRGACURE 184” [Chemical name 1-hydroxy-cyclohexyl-phenyl-ketone: R ¹ in the formula (1) of Ciba Specialty Chemicals Co. And R ^{2 taken} together to form a cyclohexane ring with the carbon atom to which they are attached, a compound in which a = 0], “DAROCUR 1173” [chemical name 2-hydroxy-2-methyl-1-phenyl -Propan-1-one: a compound in which R ¹ and R ² are methyl groups and a = 0 in the formula (1)], “IRGACURE 2959” [chemical name 1- [4- (2-hydroxyethoxy) - phenyl] -2-hydroxy-2-methyl-1-: in formula (1), R ¹ and R ² are each methyl group, with a = 1 Ri, X ¹ is 2-hydroxyethoxy group, the substitution positions compound is para], and the like to the carbonyl group.

  When an alkylphenone compound having an alkoxy group at the α-position is used as the alkylphenone compound having a hydroxy group or an alkoxy group at the α-position, this compound is an α-alkoxyalkylphenone (α-alkoxyalkyl phenyl ketone) or its It can be a substituted derivative, and preferred examples thereof include those represented by the following formula (2).

In formula (2), R ⁴ and R ⁵ each represent an alkyl group, an aryl group, an aralkyl group or an alkoxy group, or R ⁴ and R ⁵ together form a ring with the carbon atom to which they are attached. is doing. R ⁶ represents an alkyl group. X ² represents an alkyl group, an aryl group, an aralkyl group, an alkoxy group, a hydroxyalkoxy group, an alkylthio group, an amino group or a substituted amino group, b represents a number from 0 to 3, and when b is 2 or more, a plurality of The existing X ² may be the same as or different from each other.

When at least one of R ⁴ and R ⁵ is an alkyl group, the example is the same as when at least one of R ¹ and R ² is an alkyl group. When at least one of R ⁴ and R ⁵ is an aryl group, the example is the same as the case where at least one of R ¹ and R ² is an aryl group. When at least one of R ⁴ and R ⁵ is an aralkyl group, examples thereof are the same as the case where at least one of R ¹ and R ² is an aralkyl group. When at least one of R ⁴ and R ⁵ is an alkoxy group, examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and the like, and the carbon number is usually 1-6. When R ⁴ and R ⁵ are taken together to form a ring with the carbon atom to which they are attached, an example of this ring is the carbon to which they are attached together with the preceding R ¹ and R ² together. This is the same as when a ring is formed with atoms.

Examples of the alkyl group represented by R ⁶ include a methyl group, an ethyl group, a propyl group, and a butyl group, and the carbon number is usually 1-6.

Examples of the alkyl group, aryl group, aralkyl group, alkoxy group, hydroxyalkoxy group, alkylthio group, amino group or substituted amino group represented by X ² are the same as those for X ¹ above.

Examples of commercially available compounds represented by the formula (2) include “IRGACURE 651” [chemical name 2,2-dimethoxy-1,2-diphenylethane-1-one: Ciba Specialty Chemicals Co., Ltd .: In (2), R ⁴ is a phenyl group, R ⁵ is a methoxy group, R ⁶ is a methyl group, and b = 0].

  The alkylphenone compound having an amino group at the α-position can be α-aminoalkylphenone (α-aminoalkyl phenyl ketone) or a substituted derivative thereof, and a preferable example thereof is represented by the following formula (3). Things can be mentioned.

In formula (3), R ⁷ and R ⁸ each represent an alkyl group, an aryl group or an aralkyl group, or R ⁷ and R ⁸ together form a ring with the carbon atom to which they are attached. . R ⁹ and R ¹⁰ each represent an alkyl group, an aryl group or an aralkyl group, or R ⁹ and R ¹⁰ together form a ring with the nitrogen atom to which they are attached. X ³ represents an alkyl group, an aryl group, an aralkyl group, an alkoxy group, a hydroxyalkoxy group, an alkylthio group, an amino group or a substituted amino group, c represents a number of 0 to 3, and when c is 2 or more, a plurality of The existing X ³ may be the same as or different from each other.

When at least one of R ⁷ and R ⁸ is an alkyl group, the example is the same as when at least one of R ¹ and R ² is an alkyl group. When at least one of R ⁷ and R ⁸ is an aryl group, the example is the same as the case where at least one of R ¹ and R ² is an aryl group. When at least one of R ⁷ and R ⁸ is an aralkyl group, examples thereof are the same as the case where at least one of R ¹ and R ² is an aralkyl group. When R ⁷ and R ⁸ are taken together to form a ring with the carbon atom to which they are attached, an example of this ring is the carbon to which they are attached together with the preceding R ¹ and R ² This is the same as when a ring is formed with atoms.

When at least one of R ⁹ and R ¹⁰ is an alkyl group, the example is the same as when at least one of R ¹ and R ² is an alkyl group. When at least one of R ⁹ and R ¹⁰ is an aryl group, examples thereof are the same as the case where at least one of R ¹ and R ² is an aryl group. When at least one of R ⁹ and R ¹⁰ is an aralkyl group, the example is the same as the case where at least one of R ¹ and R ² is an aralkyl group. When R ⁹ and R ¹⁰ are combined to form a ring with the nitrogen atom to which they are bonded, examples of this ring include pyrrolidine ring, piperidine ring, morpholine ring, etc. Is usually 5-10.

Examples of the alkyl group, aryl group, aralkyl group, alkoxy group, hydroxyalkoxy group, alkylthio group, amino group or substituted amino group represented by X ³ are the same as those for X ¹ above.

Examples of commercially available compounds represented by the formula (3) include “IRGACURE 907” [chemical name 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopro of Ciba Specialty Chemicals Co., Ltd. Pan-1-one: In the formula (3), R ⁷ and R ⁸ are each a methyl group, and R ⁹ and R ¹⁰ are combined to form a morpholine ring together with the nitrogen atom to which they are bonded; Compound in which c = 1, X ³ is a methylthio group, and the substitution position is para position of the carbonyl group], “IRGACURE 369” [chemical name 2-benzyl-2-dimethylamino-1- (4-morphol Rinofeniru) - butanone -1: in formula (3), R ⁷ is an ethyl group, R ⁸ is a benzyl group, R ⁹ and R ¹⁰ are each a methyl group, a c = 1, X ³ A compound having a morpholino group and the substitution position at the para position of the carbonyl group], “IRGACURE 379” [chemical name 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone: In the formula (3), R ⁷ is an ethyl group, R ⁸ is a p-tolylmethyl group, R ⁹ and R ¹⁰ are each a methyl group, and c = 1 and X ³ is a morpholino group, and the substitution position is the para position of the carbonyl group].

  The total use amount of the photopolymerization initiator is usually 0.1 parts by weight or more with respect to 100 parts by weight of the radical polymerizable compound. If the amount used is too small, the curing rate tends not to increase as compared with the case where no photopolymerization initiator is used. In addition, the upper limit of the usage-amount of a photoinitiator is about 10 weight part normally with respect to 100 weight part of radically polymerizable compounds.

  The ratio of the alkylphenone compound having a hydroxy group or alkoxy group at the α-position and the alkylphenone compound having an amino group at the α-position in the photopolymerization initiator is usually based on the total of 100 parts by weight of both, The former is 5 to 95 parts by weight, the latter is 95 to 5 parts by weight, and preferably the former is 30 to 70 parts by weight and the latter is 70 to 30 parts by weight.

  As the alkylphenone compound having a hydroxy group or an alkoxy group at the α-position, an alkylphenone compound having a hydroxy group at the α-position and an alkylphenone compound having an alkoxy group at the α-position may be used in combination. Further, an alkylphenone compound having a hydroxy group at the α-position, an alkylphenone compound having an alkoxy group at the α-position, and an alkylphenone compound having an amino group at the α-position may each be used in combination of two or more thereof. Good.

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

  The curable coating preferably contains a leveling agent, which can improve the smoothness and scratch resistance of the cured coating. 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.

  The usage-amount of a silicone oil is 0.01-20 weight part normally with respect to 100 weight part of radically polymerizable compounds, Preferably it is 0.01-15 weight part. If the amount used is too small, the intended effect is difficult to be recognized. If the amount is too large, the curable coating tends to be insufficiently cured and the appearance of the cured film tends to deteriorate.

  In addition, the curable coating may contain conductive fine particles as necessary. By containing the conductive fine particles, a cured film having antistatic performance and antistatic performance can be formed.

  Examples of the conductive fine particles include metal oxides such as antimony oxide, indium / tin composite oxide (ITO), tin / antimony composite oxide (ATO), antimony / zinc composite oxide, and doping with phosphorus. And fine particles such as tin oxide.

  The conductive fine particles preferably have a particle size of 0.001 to 0.1 μm. When the particle size is too small, industrial production is difficult, and when the particle size is too large, the transparency of the cured film is lowered, which is not preferable. Moreover, it is preferable that the usage-amount of electroconductive fine particles is 1-100 weight part with respect to 100 weight part of radically polymerizable compounds. If the amount used is too small, a sufficient antistatic effect cannot be obtained, and if it is too large, the scratch resistance of the cured film is lowered or the film formability is lowered.

  In addition, the curable paint may contain a solvent in order to adjust the viscosity, the thickness of the cured film, and the like. Examples of the solvent include methanol, ethanol, 1-propanol, 2-propanol (isopropyl alcohol), 1-butanol, 2-butanol (sec-butyl alcohol), 2-methyl-1-propanol (isobutyl alcohol), 2 Alcohols such as methyl-2-propanol (tert-butyl alcohol), 2-ethoxyethanol, 2-butoxyethanol, 3-methoxy-1-propanol, 1-methoxy-2-propanol, 1-ethoxy-2- Alkoxy alcohols such as propanol, ketols such as diacetone alcohol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, aromatic hydrocarbons such as toluene, xylene, ethyl acetate, butyl acetate, etc. D Such as ethers, and the like. The amount of the solvent used is appropriately adjusted according to the substrate material, shape, coating method, thickness of the target cured film, etc., but is usually 20 to 10,000 weights with respect to 100 parts by weight of the radical polymerizable compound. About a part.

  Furthermore, additives such as stabilizers, antioxidants, and colorants may be included in the curable coating as necessary.

  After applying the curable coating described above to the surface of the resin substrate, it is dried if necessary, and then the formed coating film is cured to form a cured film having high scratch resistance on the surface of the resin substrate. Can be formed.

  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 ultraviolet rays. The intensity and irradiation time of ultraviolet rays are appropriately adjusted according to the type of radical polymerizable compound and photopolymerization initiator, the thickness of the coating film, and the like. Ultraviolet rays 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, more preferably 2 to 6 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 film can be adjusted by adjusting the amount per area of the curable coating applied to the surface of the resin substrate and the solid content concentration contained in the curable coating.

  The scratch-resistant resin plate of the present invention thus obtained has a cured film with high scratch resistance formed on the surface of the resin substrate, and is suitable as a display window protection plate for portable information terminals typified by mobile phones. Can be used. Further, it can be used as various members in fields where scratch resistance is required, such as a finder portion of a digital camera or a handheld video camera, or a display window protection plate of a portable game machine.

  In order to produce a display window protection plate for a portable information terminal from the scratch-resistant resin plate of the present invention, first, if necessary, processing such as printing and drilling may be performed and cut to a required size. After that, if it is set on the display window of the portable information terminal, a display window with high scratch resistance can be obtained.

  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 thickness of the cured film of the scratch-resistant resin plate obtained in each example was measured using a film thickness measuring device [F-20 from Filmmetrics].

In addition, the scratch resistance of the cured film of the scratch-resistant resin plate obtained in each example was scratched with steel wool # 0000 with a load of 2000 g / 4 cm ² at 10 reciprocations, 150 reciprocations, and 100 reciprocal steps. Were rubbed until visually confirmed, and evaluated by the number of reciprocations.

Example 1
50 parts of dipentaerythritol hexaacrylate and 50 parts of pentaerythritol tetraacrylate as radically polymerizable compounds, “IRGACURE 184” [Chemical name 1-hydroxy-cyclohexyl-phenyl-ketone: Ciba Specialty Chemicals Co., Ltd.] as a photopolymerization initiator: In the formula (1), R ¹ and R ² are combined to form a cyclohexane ring together with the carbon atom to which they are bonded, a compound in which a = 0, 4.5 parts and “IRGACURE 907” [Chemicals Name 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one: In the formula (3), R ⁷ and R ⁸ are each a methyl group, and R ⁹ and R ¹⁰ are together To form a morpholine ring with the nitrogen atom to which they are attached, and c = 1 Ri, X ³ is a methylthio group, para, compound] 1.5 parts of the substitution positions carbonyl group, as a leveling agent BYK Chemie Japan of (Co.) "BYK-307" (a silicone oil) 0.1 Part, and 125 parts of isobutyl alcohol and 125 parts of 1-methoxy-2-propanol as a solvent were mixed to prepare a curable coating material.

This paint was applied to both sides of a methacrylic resin plate (Sumitex E, Sumitomo Chemical Co., Ltd.) having a thickness of 2 mm and a size of 100 mm × 60 mm by a dipping coating method, followed by drying at room temperature for 5 minutes, and further at 10 ° C. at 50 ° C. The coating film was formed on the surface of the methacrylic resin plate by drying for minutes. Next, the coating film was cured by irradiating with an ultraviolet ray of 0.5 J / cm ² using a 120 W high-pressure mercury lamp to obtain a scratch-resistant resin plate having a cured coating thickness of 3.7 μm. Table 1 shows the results of evaluating the scratch resistance of the scratch-resistant resin plate.

Example 2
A scratch-resistant resin plate having a cured coating thickness of 3.8 μm, the same operation as in Example 1 except that 3 parts of “IRGACURE 184” and 3 parts of “IRGACURE 907” were used as the photopolymerization initiator. Got. Table 1 shows the results of evaluating the scratch resistance of the scratch-resistant resin plate.

Comparative Example 1
Except for using 6 parts of “IRGACURE 184” as a photopolymerization initiator, the same operation as in Example 1 was performed to obtain a scratch-resistant resin plate having a cured coating thickness of 3.2 μm. Table 1 shows the results of evaluating the scratch resistance of the scratch-resistant resin plate.
Comparative Example 2
Except for using 6 parts of “IRGACURE 907” as a photopolymerization initiator, the same operation as in Example 1 was performed to obtain a scratch-resistant resin plate having a cured coating thickness of 3.5 μm. Table 1 shows the results of evaluating the scratch resistance of the scratch-resistant resin plate. The scratch-resistant resin plate had a yellowish cured film.

I-184: “IRUGACURE 184”
I-907: “IRUGACURE 907”

Claims (9)

  A cured film is formed on the surface of the resin substrate by a curable paint containing a radical polymerizable compound, an alkylphenone compound having a hydroxy group or an alkoxy group at the α-position, and an alkylphenone compound having an amino group at the α-position. A scratch-resistant resin plate characterized by comprising:   The scratch-resistant resin plate according to claim 1, wherein the radical polymerizable compound is a compound having at least three (meth) acryloyloxy groups in the molecule. An alkylphenone compound having a hydroxy group or an alkoxy group at the α-position is represented by the formula (1)

(Wherein R ¹ and R ² each represent an alkyl group, an aryl group or an aralkyl group, or R ¹ and R ² together form a ring with the carbon atom to which they are bonded. X ¹ represents an alkyl group, an aryl group, an aralkyl group, an alkoxy group, a hydroxyalkoxy group, an alkylthio group, an amino group or a substituted amino group, a represents a number of 0 to 3, and when a is 2 or more, a plurality thereof X ¹ may be the same as or different from each other.)
The scratch-resistant resin plate according to claim 1 or 2, wherein An alkylphenone compound having a hydroxy group or an alkoxy group at the α-position is represented by the formula (2)

(Wherein R ⁴ and R ⁵ each represents an alkyl group, an aryl group, an aralkyl group or an alkoxy group, or R ⁴ and R ⁵ together form a ring with the carbon atom to which they are bonded; R ⁶ represents an alkyl group, X ² represents an alkyl group, an aryl group, an aralkyl group, an alkoxy group, a hydroxyalkoxy group, an alkylthio group, an amino group or a substituted amino group, and b represents a number of 0 to 3. , B is 2 or more, a plurality of X ² may be the same or different.)
The scratch-resistant resin plate according to claim 1 or 2, wherein An alkylphenone compound having an amino group at the α-position is represented by the formula (3)

(Wherein R ⁷ and R ⁸ each represents an alkyl group, an aryl group or an aralkyl group, or R ⁷ and R ⁸ together form a ring with the carbon atom to which they are attached. R ⁹ and R ¹⁰ each represents an alkyl group, an aryl group or an aralkyl group, or R ⁹ and R ¹⁰ together form a ring with the nitrogen atom to which they are bonded, X ³ is an alkyl group, Represents an aryl group, an aralkyl group, an alkoxy group, a hydroxyalkoxy group, an alkylthio group, an amino group or a substituted amino group, c represents a number of 0 to 3, and when c is 2 or more, a plurality of X ³ are present together. It may be the same or different.)
The scratch-resistant resin plate according to any one of claims 1 to 4, wherein   The scratch-resistant resin plate according to any one of claims 1 to 5, wherein the curable coating further contains silicone oil.   The scratch-resistant resin plate according to any one of claims 1 to 6, wherein the resin substrate is a methacrylic resin plate.   The scratch-resistant resin plate according to any one of claims 1 to 7, wherein the resin substrate has a thickness of 0.1 to 3 mm.   A display window protection plate for a portable information terminal comprising the scratch-resistant resin plate according to claim 1.