JP2012046653A - Curable composition, scratch-resistant resin plate, and display window protection plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable composition formable of a cured coating excellent in fingerprint adhesion resistance, fingerprint wiping property, scratch resistance and surface hardness, and to provide a scratch-resistant resin plate and a display window protection plate.SOLUTION: The curable composition contains a curable compound (A) having at least two (meth)acryloyloxy groups in a molecule, and a compound (B) having a structure represented by general formula (I) as a repeated unit, and having a (meth)acryloyloxy group on at least one terminal, wherein the content of the compound (B) is 0.1-40 pts. wt to the 100 pts. wt curable compound (A). The scratch-resistant resin plate has a cured coating formed by curing the curable composition, and the display window protection plate for a personal digital assistance comprises the scratch-resistant resin plate. [In the formula, Rrepresents a hydrogen atom or a methyl group, and Rrepresents 10-19C linear or branched alkyl group].

Description

  The present invention relates to a curable composition, an abrasion-resistant resin plate having a cured film obtained by curing the curable composition, and a display window protection plate for a portable information terminal comprising the abrasion-resistant resin plate.

  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.

  In these portable information terminals, character information and image information are displayed by a method such as liquid crystal or EL (electroluminescence), and a cured film is formed on the surface of the display window. A scratch-resistant resin plate is used as a protective plate.

  The protective plate of the display window in the portable information terminal is often directly touched with a finger. For this reason, the cured film has fingerprint resistance that makes it difficult to notice fingerprints, fingerprint wiping properties that make it easy to wipe off fingerprints, scratch resistance that prevents scratches when wiping off fingerprints, and performance such as surface hardness. Is required.

Patent Document 1 discloses an active energy ray-curable composition containing a curable (meth) acrylate compound and a (meth) acrylic acid ester having an alkyl chain having 10 to 19 carbon atoms, and this active energy ray-curable composition. And a laminated resin plate having a cured film made of a product.
However, the laminated resin plate described in Patent Document 1 has insufficient fingerprint resistance and fingerprint wiping properties.

JP 2010-77282 A

  An object of the present invention is to provide a curable composition capable of forming a cured film excellent in fingerprint resistance, fingerprint wiping property, scratch resistance and surface hardness, and a scratch resistant resin plate and a display window protection plate. That is.

［式中、Ｒ₁は、水素原子またはメチル基を示す。Ｒ₂は、炭素数１０〜１９の直鎖または分岐したアルキル基を示す。］
（２）前記硬化性化合物（Ａ）が、分子中に少なくとも６個の（メタ）アクリロイルオキシ基を有する化合物と、分子中に４個または５個の（メタ）アクリロイルオキシ基を有する化合物と、を含有する前記（１）に記載の硬化性組成物。
（３）さらにアクリル系レベリング剤を含有する前記（１）または（２）に記載の硬化性組成物。
（４）前記（１）〜（３）のいずれかに記載の硬化性組成物を硬化させてなる硬化被膜を樹脂基板の少なくとも片面に有する耐擦傷性樹脂板。
（５）前記（４）に記載の耐擦傷性樹脂板からなる携帯型情報端末の表示窓保護板。 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 curable compound (A) having at least two (meth) acryloyloxy groups in the molecule, a structure represented by the following general formula (I) as a repeating unit, and at least one terminal is A compound (B) that is a (meth) acryloyloxy group, and the content of the compound (B) is 0.1 to 40 parts by weight with respect to 100 parts by weight of the curable compound (A). A curable composition characterized by that.

[Wherein, R ₁ represents a hydrogen atom or a methyl group. R ₂ represents a linear or branched alkyl group having 10 to 19 carbon atoms. ]
(2) The curable compound (A) is a compound having at least 6 (meth) acryloyloxy groups in the molecule, and a compound having 4 or 5 (meth) acryloyloxy groups in the molecule; The curable composition as described in said (1) containing.
(3) The curable composition according to (1) or (2), further comprising an acrylic leveling agent.
(4) A scratch-resistant resin plate having a cured film formed by curing the curable composition according to any one of (1) to (3) on at least one surface of a resin substrate.
(5) A display window protection plate for a portable information terminal comprising the scratch-resistant resin plate according to (4).

  The “portable information terminal” in the present invention means a generic name of 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. For example, the mobile phone, PHS, PDA, etc. exemplified above are mentioned.

  According to the present invention, a cured film having excellent fingerprint resistance, fingerprint wiping property, scratch resistance and surface hardness can be formed. Therefore, the scratch-resistant resin plate having this cured film is displayed on a portable information terminal. By using it as a window protection plate, the display window can be effectively protected.

  The curable composition of the present invention contains a curable compound (A) and a specific compound (B). The curable compound (A) has a property of curing when irradiated with an activation energy beam such as an electron beam or ultraviolet ray, and has at least 2, preferably 2 to 7, more preferably 4 to 4 in the molecule. It has 6 (meth) acryloyloxy groups. When the curable composition contains the curable compound (A), the formed cured film has excellent scratch resistance and surface hardness (pencil hardness). In this 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 the curable compound (A) include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and neopentyl glycol di (meth) acrylate. Compound having two (meth) acryloyloxy groups; glycerin tri (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, tris [(meth) acryloyloxyethyl] isocyanurate, Compounds having three (meth) acryloyloxy groups in the molecule such as pentaerythritol tri (meth) acrylate and dipentaerythritol tri (meth) acrylate; pentaerythritol tetra (meth) acrylate, Compounds having 4 or 5 (meth) acryloyloxy groups in the molecule such as pentaerythritol tetra (meth) acrylate and dipentaerythritol penta (meth) acrylate; dipentaerythritol hexa (meth) acrylate and tripentaerythritol hexa A compound having 6 (meth) acryloyloxy groups in a molecule such as (meth) acrylate; at least 7 (meta) in a molecule such as tripentaerythritol hepta (meth) acrylate and tripentaerythritol octa (meth) acrylate ) A compound having an acryloyloxy group and the like may be mentioned, and these may be used alone or in combination of two or more.

  Further, a urethane (meth) acrylate compound obtained by a reaction between a compound having X isocyanato groups in the molecule and a compound having a hydroxyl group and Y (meth) acryloyloxy groups in the molecule, An ester (meth) acrylate compound obtained by reacting a compound having one halocarbonyl group with a compound having a hydroxyl group and Y (meth) acryloyloxy groups in the molecule is converted into X × Y ( Examples of the compound having a (meth) acryloyloxy group can be given. Note that Y is at least two.

  The curable compound (A) contains a compound having at least 6 (meth) acryloyloxy groups in the molecule and a compound having 4 or 5 (meth) acryloyloxy groups in the molecule. Is preferred. Thereby, since the reactivity of a curable compound (A) increases, the abrasion resistance and surface hardness of the formed cured film can be improved. The ratio of the compound having at least 6 (meth) acryloyloxy groups in the molecule to the compound having 4 or 5 (meth) acryloyloxy groups in the molecule is based on a total amount of 100 parts by weight of both. As a rule, the former is 5 to 95 parts by weight and the latter is 95 to 5 parts by weight, preferably the former is 30 to 70 parts by weight and the latter is 70 to 30 parts by weight.

  On the other hand, the compound (B) has the structure represented by the general formula (I) as a repeating unit, and at least one terminal is a (meth) acryloyloxy group. This compound (B) has the effect of improving the affinity for lipids, which are the main components of fingerprints. Therefore, the cured film formed by curing the curable composition containing the compound (B) has a fingerprint The adhesion mark becomes inconspicuous.

In the general formula (I), R ₁ represents a hydrogen atom or a methyl group. R ₂ represents an alkyl group having 10 to 19 carbon atoms. Examples of the alkyl group having 10 to 19 carbon atoms include a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, and a nonadecyl group. These alkyl groups may be either linear or branched.

Specific examples of the compound (B) include compounds in which R ₁ is a methyl group, R ₂ is an n-octadecyl group having 18 carbon atoms, and one or both ends are methacryloyloxy groups. As the compound (B), one type of compound may be used, or two or more types of compounds may be used in combination.

  As the compound (B), a commercially available compound can be used, but it can also be obtained by synthesis. The method for synthesizing the compound (B) is not particularly limited. For example, the compound (B) has a linear or branched alkyl group having 10 to 19 carbon atoms in the presence of a compound having a mercapto group and a hydroxyl group. An acrylate may be polymerized by a bulk polymerization method, a solution polymerization method, or the like to obtain a polymer, and the polymer may be reacted with a functional group that reacts with the hydroxyl group and a compound having a (meth) acryloyloxy group.

  As an example of the synthesis method of the compound (B), mercaptoethanol is used as the compound having a mercapto group and a hydroxyl group, and 2-isocyanatoethyl methacrylate is used as the compound having a functional group that reacts with a hydroxyl group and a (meth) acryloyloxy group. The case where each is used will be described as an example. First, stearyl methacrylate and mercaptoethanol are added to a solvent such as methyl isobutyl ketone, and an inert gas atmosphere such as nitrogen is used at a temperature of 100 to 140 ° C. for 2 to 6 hours. Polymerize. At this time, various known initiators may be used. Next, 2-isocyanatoethyl methacrylate is added to the solvent and reacted at 80 to 120 ° C. At this time, various known polymerization inhibitors may be used. And when reaction is complete | finished when an isocyanate group becomes fixed, a compound (B) will be obtained.

  The content of the compound (B) is 0.1 to 40 parts by weight, preferably 0.5 to 35 parts by weight, more preferably 1 to 30 parts by weight with respect to 100 parts by weight of the curable compound (A). . As a result, the affinity of the cured coating for lipids is moderately improved, the fingerprint attachment traces are not noticeable, and the attached fingerprints are easily wiped off. Moreover, it exists in the tendency for the abrasion resistance of a cured film to improve, so that there is little content of a compound (B).

  On the other hand, when there is too little content of a compound (B), the effect by a compound (B) will become difficult to be acquired. Moreover, when there is too much content of a compound (B), abrasion resistance, surface hardness, and fingerprint wiping property will fall.

  The curable composition may contain conductive fine particles as necessary. Thereby, a cured film having antistatic performance and antistatic performance can be formed. As the conductive fine particles, for example, a metal oxide such as antimony oxide, an indium / tin composite oxide (ITO), a tin / antimony composite oxide (ATO), an antimony / zinc composite oxide, or doped with phosphorus. And tin oxide.

  The average particle size of the conductive fine particles is preferably 0.001 to 0.1 μm. When the average particle size is too small, industrial production is difficult, and when the average particle size is too large, the transparency of the cured film is lowered, which is not preferable.

  The content of the conductive fine particles is preferably 1 to 100 parts by weight with respect to 100 parts by weight of the curable compound (A). If the content is too small, a sufficient antistatic effect cannot be obtained, and if the content is too large, the scratch resistance of the cured film is lowered or the film formability is lowered.

  Moreover, in order to adjust a viscosity, the thickness of a cured film, etc., the curable composition may contain the solvent. 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-propanol, etc. Ketols such as diacetone alcohol; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate. These solvents are used alone or in combination of two or more.

  The content of the solvent is appropriately adjusted according to the substrate material, shape, coating method, target thickness of the cured film, etc., but is usually 20 to 10 with respect to 100 parts by weight of the curable compound (A). 1,000 parts by weight.

  Furthermore, the curable composition may contain additives such as a stabilizer, an antioxidant, a colorant, a leveling agent, and silica particles as necessary. In particular, when a leveling agent is included, the smoothness and scratch resistance of the cured film can be improved.

  Examples of the leveling agent 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-modified silicone oil, fluorine-modified silicone oil, polyether Silicone oil such as modified silicone oil; Acrylic leveling such as acrylic copolymer Etc., and these may be used alone or in combination of two or more. Among these, an acrylic leveling agent is preferable.

  Content of a leveling agent is 0.01-20 weight part normally with respect to 100 weight part of said curable compounds (A). If the content is too small, it is difficult to obtain the effect of the leveling agent.

  Moreover, when the curable composition contains silica particles, color unevenness due to light interference is reduced, which is preferable. The reason for this is presumed to be that when the silica particles are contained, the refractive index of the formed cured film is close to the refractive index of the resin substrate.

  As a silica particle, an average particle diameter of 5 nm-10 micrometers is preferable, and an average particle diameter of 5 nm-100 nm is more preferable. Silica particles having an average particle size that is too small are difficult to produce industrially, and if the average particle size is too large, optical performance such as transparency of the coating is deteriorated.

  Further, porous silica fine particles may be used as the silica particles. The porous silica may be a silica that is obtained by hydrolyzing alkoxysilane in the presence of an alkali and is highly entangled and branched to form a polymer, as described in JP-A-7-133105. The surface-coated porous silica produced by a conventional method may be used.

  The surface of the silica particles may be modified with an organosilicon compound by, for example, a method disclosed in JP-A-7-133105 in order to improve the dispersibility and increase the affinity with the cationic polymerizable compound. Silica particles can also be used in the form of a sol.

  The content of the silica particles is preferably 10 to 30 parts by weight with respect to 100 parts by weight of the curable compound (A). If the content of silica particles is too large, the strength of the cured film is lowered, which is not preferable. Further, if the content of silica particles is too small, it is difficult to obtain the effect of silica particles, which is not preferable.

  The curable composition described above is applied to at least one surface of the resin substrate, and then dried as necessary, and then the formed coating film is cured, whereby the scratch resistance having a cured coating on at least one surface of the resin substrate. Can be obtained.

  The resin constituting the resin substrate is preferably a transparent thermoplastic resin, and specific examples thereof include methacrylic resin, polyester resin, polycarbonate resin, polycyclic olefin resin, polystyrene resin, and methacryl-styrene copolymer ( MS resin), acrylonitrile-styrene copolymer (AS resin), polyvinylidene fluoride resin (PVDF resin), and the like. Among these, a methacrylic resin is preferable because it has a high surface hardness and a cured film having high scratch resistance is easily formed. Polycarbonate resins are preferred because they have high impact resistance and are difficult to break.

  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, a pigment, or the like as necessary, or may contain an antioxidant, an ultraviolet absorber, rubber particles, or the like. The thickness of the resin substrate is suitably about 0.1 to 3.0 mm.

  The resin substrate may be a single layer or a multilayer structure. As the resin substrate having a multilayer structure, a substrate in which a methacrylic resin layer is laminated on at least one surface of a polycarbonate resin layer is preferable. When a methacrylic resin layer is laminated on both surfaces of the polycarbonate resin layer, it is preferable to contain rubber particles in at least one of the methacrylic resin layers.

  The curable composition 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 rays are used as the activation energy rays, 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.

  Since said photoinitiator is 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”, sold by Ciba Specialty Chemicals, Inc., respectively. “DAROCUR 1173”, “IRGACURE 907”, “IRGACURE 369”, “IRGACURE 1700”, “IRGACURE 1800”, “IRGACURE 819”, and “IRGACURE 784”, respectively, “KAYACURE” sold by Nippon Kayaku Co., Ltd. "ITX", "KAYACURE DETX-S", "KAYACURE BP-100", "KAYACURE BMS", and "KAYACURE 2-E" AQ "and the like.

  The content of the photopolymerization initiator is usually 0.1 to 10 parts by weight with respect to 100 parts by weight of the curable compound (A). If the content is too small, the curing rate tends not to increase as compared with the case where no photopolymerization initiator is used. If the content is too large, the photopolymerization initiator will be contained more than necessary, so there is no reaction. The photopolymerization initiator tends to remain, and the surface hardness of the coating film tends to decrease. Moreover, it is not preferable also economically.

  Moreover, the intensity | strength and irradiation time of an activation energy ray are suitably adjusted according to the kind of curable compound, the thickness of the coating film, etc. The activation energy beam may be irradiated in an inert gas atmosphere. Examples of the inert gas include nitrogen gas and argon gas.

  The thickness of the cured film to be formed is preferably 1 to 10 μm, and 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 can be arbitrarily adjusted by adjusting the amount per area of the curable composition applied to the surface of the resin substrate and the solid content concentration contained in the curable composition.

  The scratch-resistant resin plate of the present invention thus obtained has a cured film excellent in fingerprint adhesion, fingerprint wiping, scratch resistance and surface hardness formed on at least one surface of the resin substrate. It can be suitably used as a display window protection plate of a representative portable information terminal. In addition, as various members in fields where fingerprint resistance, fingerprint wiping, scratch resistance and surface hardness are required, such as viewfinders for digital cameras and handy video cameras, display window protection plates for portable game machines, etc. Can also be used.

  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, processing such as printing and drilling is performed as necessary, and cutting processing is performed to a required size. Next, the cut-resistant scratch-resistant resin plate is set on the display window of the portable information terminal. Thereby, it can be set as the display window which is excellent in fingerprint adhesion resistance, fingerprint wiping off property, scratch resistance, and surface hardness.

  EXAMPLES Hereinafter, although a synthesis example and an Example are given and this invention is demonstrated in detail, this invention is not limited only to the following synthesis examples and Examples. In the following synthesis examples and examples, the part representing the content or amount used is based on weight unless otherwise specified. Moreover, the measuring method and evaluation method of each physical property are as follows.

(Thickness of cured film)
The film thickness was measured using a film thickness measuring apparatus (“F-20” manufactured by Filmmetrics).

(Total light transmittance (Tt) and haze of scratch-resistant resin plate)
It was measured using a reflectometer ["HR-100" manufactured by Murakami Color Research Laboratory Co., Ltd.].

(Abrasion resistance of cured film)
Using steel wool # 0000, the surface of the cured coating was rubbed at a load of 500 g / cm ² for 10 reciprocations, 50 reciprocations, and 100 reciprocation increments until the damage was visually confirmed, and the number of reciprocations was evaluated.

(Pencil hardness of cured film)
In accordance with JIS K5600, evaluation was performed using a pencil hardness tester manufactured by Yasuda Seiki Seisakusho.

(Contact angle of cured coating)
Using water and oleic acid, each was measured with a contact angle meter [“CA-X” manufactured by Kyowa Interface Science Co., Ltd.].

(Fingerprint resistance)
A finger was pressed against the surface of the cured coating to deposit the fingerprint, then placed in a black box, and the appearance of the surface of the cured coating was visually evaluated from directly above under a short wavelength fluorescent lamp. The following criteria were used.
○: The fingerprint is inconspicuous.
Δ: The fingerprint is conspicuous.
X: The fingerprint is very conspicuous.

(Fingerprint wiping property)
After the finger was pressed against the surface of the cured coating to attach the fingerprint, the wiping property of the fingerprint was evaluated with a tissue paper (“Erière” manufactured by Daio Paper Co., Ltd.). The following criteria were used.
○: The fingerprint can be wiped off, and the surface of the cured film is not damaged.
Δ: Fingerprints can be wiped off, but the surface of the cured coating is scratched.
X: The fingerprint cannot be wiped off.

Compound (B) used in Examples and Comparative Examples was synthesized as follows.
<Synthesis Example of Compound (B)>
First, stearyl methacrylate was added to a three-necked flask. Next, 1.8 parts of mercaptoethanol as a chain transfer agent and 0.5 parts of azobisisobutyronitrile as an initiator were added to 100 parts of stearyl methacrylate. Further, methyl isobutyl ketone was added as a solvent, the temperature was raised to 120 ° C. under a nitrogen atmosphere, the reaction was carried out at 120 ° C. for 4 hours, and then cooled to room temperature (23 ° C.).

  Next, 0.04 part of hydroquinone monomethyl ether and 4 parts of 2-isocyanatoethyl methacrylate are added to the three-necked flask as a polymerization inhibitor in a ratio of 4 parts, and the reaction is carried out at 100 ° C. in dry air, so that the isocyanate group is constant. The reaction was terminated and cooled to yield compound (B).

The curable compositions (C-1 to 8) used in Examples and Comparative Examples were prepared as follows.
<Preparation of curable composition (C-1 to 6)>
50 parts of dipentaerythritol hexaacrylate, 50 parts of pentaerythritol tetraacrylate, 100 parts of dipentaerythritol hexaacrylate and pentaerythryl tetraacrylate, the ratio of compound (B) shown in Table 1, starting photopolymerization 7 parts of IRGACURE 184 as an agent, 1 part of “BYK-394” manufactured by Big Chemie Japan as an acrylic leveling agent, and 300 parts of butyl acetate as a solvent are mixed to obtain a curable composition (C-1 6) was prepared.

<Preparation of curable composition (C-7)>
100 parts of compound (B), 7 parts of IRGACURE 184 as a photopolymerization initiator, 1 part of “BYK-394” manufactured by Big Chemie Japan as an acrylic leveling agent, and 300 parts of butyl acetate as a solvent Then, a curable composition (C-7) was prepared.

<Preparation of curable composition (C-8)>
50 parts of dipentaerythritol hexaacrylate, 50 parts of pentaerythritol tetraacrylate, 5 parts of stearyl methacrylate for a total amount of 100 parts of dipentaerythritol hexaacrylate and pentaerythryl tetraacrylate, and IRGACURE 184 as a photopolymerization initiator 7 parts, 1 part of “BYK-394” manufactured by Big Chemie Japan as an acrylic leveling agent and 300 parts of butyl acetate as a solvent were mixed to prepare a curable composition (C-8).

[Examples 1 to 5 and Comparative Examples 1 to 3]
First, each of the curable compositions (C-1 to 8) obtained above was placed on one side of a methacrylic resin plate (“SUMIPEX E” manufactured by Sumitomo Chemical Co., Ltd.) having a thickness of 2 mm and a size of 100 mm × 60 mm. After each coating by the coater method, it was dried at room temperature for 1 minute and further dried at 60 ° C. for 3 minutes to form a coating film on one side of the methacrylic resin plate.

Subsequently, the coating film was cured by irradiating ultraviolet rays of 0.5 J / cm ² using a 120 W high-pressure mercury lamp to obtain a scratch-resistant resin plate having a cured film having a thickness of 4 μm on one side. About each obtained scratch-resistant resin board, total light transmittance (Tt), haze, scratch resistance, pencil hardness, a contact angle, fingerprint adhesion property, and fingerprint wiping property were evaluated according to the above-mentioned method. The results are shown in Table 1.

  As is apparent from Table 1, Examples 1 to 5 are excellent in scratch resistance, pencil hardness, fingerprint resistance and fingerprint wiping property. On the other hand, Comparative Example 1 in which the content of the compound (B) is more than 40 parts by weight showed results inferior in scratch resistance and fingerprint wiping property. Further, Comparative Example 2 which does not contain the curable compound (A) and the content of the compound (B) is more than 40 parts by weight shows results inferior in scratch resistance and fingerprint wiping property, and has a pencil hardness. Remarkably inferior results were shown. Although the comparative example 3 which does not contain the compound (B) was excellent in scratch resistance, it showed results inferior in fingerprint resistance and fingerprint wiping property.

Claims (5)

A curable compound (A) having at least two (meth) acryloyloxy groups in the molecule;
A compound (B) having a structure represented by the following general formula (I) as a repeating unit and at least one terminal of which is a (meth) acryloyloxy group,
Content of the said compound (B) is 0.1-40 weight part with respect to 100 weight part of said curable compounds (A), The curable composition characterized by the above-mentioned.

[Wherein, R ₁ represents a hydrogen atom or a methyl group. R ₂ represents a linear or branched alkyl group having 10 to 19 carbon atoms. ]   The curable compound (A) contains a compound having at least 6 (meth) acryloyloxy groups in the molecule and a compound having 4 or 5 (meth) acryloyloxy groups in the molecule. The curable composition according to claim 1.   Furthermore, the curable composition of Claim 1 or 2 containing an acrylic leveling agent.   A scratch-resistant resin plate having a cured film formed by curing the curable composition according to claim 1 on at least one surface of a resin substrate.   A display window protective plate for a portable information terminal comprising the scratch-resistant resin plate according to claim 4.