JP2002347045A - Method for manufacturing acrylic resin laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an acrylic resin laminate suppressed in coloration and having sufficient antistatic properties and excellent in scratch resistance and transparency. SOLUTION: A crosslinked film containing fine particles of indium oxide is formed on the surface of an acrylic resin sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an acrylic resin laminate excellent in transparency, antistatic property and scratch resistance. The acrylic resin laminate obtained by the present invention can be suitably used for applications such as members related to a semiconductor factory and a display front panel.

[0002]

2. Description of the Related Art Generally, acrylic resins are widely used as industrial materials, building materials, etc. because of their characteristics such as transparency, impact resistance, and easy moldability. In recent years, because of its transparency and impact resistance, it has been used as a front plate for various displays such as CRTs (CRTs) and liquid crystal televisions.

However, as with other resins,
Acrylic resin is softer than glass, so that the surface of the acrylic resin may be easily scratched by scratching or the like. Further, since the volume resistivity of the acrylic resin is generally high, the transparency of the acrylic resin may be easily reduced due to the adhesion of dust to the surface of the acrylic resin due to static electricity. Many attempts have been made to improve acrylic resins in order to solve or alleviate these problems, but there is no known means for providing satisfactory results.

For example, as a method for improving the scratch resistance of an acrylic resin, it is known to use a polyfunctional monomer such as a polyfunctional (meth) acrylate to form a crosslinked film on the surface of a substrate. . However, such a conventional crosslinked film for an acrylic resin often shows no antistatic ability, or the obtained antistatic ability is often insufficient.

On the other hand, as a method for improving the antistatic property, there is known a method in which a coating film containing a conductive powder containing tin oxide as a main component is laminated on an acrylic resin. For example, JP-A-60-60166 and JP-A-60-60
JP-A-181177 discloses a coating composition having excellent scratch resistance and hardness, and a tin oxide having an average particle diameter of 0.2 μm or less as a main component as a coating composition capable of forming a coating film having excellent conductivity and transparency. A conductive coating composition containing a conductive powder is disclosed. Japanese Patent Publication No. 7-31953 and the like disclose a polymerizable composition for forming a scratch-resistant coating containing a conductive powder containing tin oxide as a main component.

[0006]

However, when a coating film containing a conductive powder containing tin oxide as a main component as described above is provided on an acrylic resin, the coating film is obtained until good scratch resistance is obtained. When the film thickness of the resin was increased, coloring by tin oxide powder occurred, and the transparency of the acrylic resin was sometimes reduced.

[0007] In view of the above situation, an object of the present invention is to
An object of the present invention is to provide a method for producing an acrylic resin laminate having a crosslinked film exhibiting sufficient antistatic properties and having excellent scratch resistance and transparency. Another object of the present invention is to provide a method for producing an acrylic resin laminate having a crosslinked film in which coloring is suppressed.

[0008]

According to the present invention, a paint for forming a crosslinked film containing indium oxide-based fine particles and a crosslinking reactive compound is coated on the inner surface of at least one mold. Coating and cross-linking and polymerizing the cross-linking reactive compound to form a cross-linked coating on the inner surface; and in a mold including at least a part of the mold on which the cross-linked coating is formed on the inner surface, A method for producing an acrylic resin laminate, comprising: a step of injecting an acrylic resin raw material; a step of polymerizing the acrylic resin raw material; and a step of peeling the acrylic resin laminate from the mold.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described more specifically. In the following description, “parts” and “%” representing the quantitative ratios are based on mass unless otherwise specified. (Acrylic Resin Laminate) The acrylic resin laminate obtained by the present invention comprises at least an acrylic resin base material (for example, a plate) and indium oxide-based fine particles formed on at least one surface of the acrylic resin base material. Containing crosslinked film. (Crosslinked film) The crosslinked film in the present invention contains indium oxide-based fine particles. The indium oxide-based fine particles can sufficiently lower the surface resistance value of the crosslinked film without impairing the abrasion resistance of the crosslinked film. Further, the coloring of the crosslinked film is less than that of tin oxide or the like which has been conventionally used. As a result, according to the present invention, it is possible to produce an acrylic resin laminate having a crosslinked film that exhibits sufficient antistatic properties and abrasion resistance, has excellent transparency, and is suppressed from being colored. (Indium oxide-based fine particles) The indium oxide-based fine particles used in the present invention are fine particles containing indium oxide as a main component. As the indium oxide-based fine particles,
Fine particles made of a material doped with a small amount of another element can also be used. The doping amount of another element is preferably 1 to 15% by mass from the viewpoint of conductivity. As the indium oxide-based fine particles, those doped with tin are preferable from the viewpoint of conductivity.

The average particle size of the indium oxide-based fine particles used in the present invention is preferably 10% in order to suppress scattering of visible light to realize good transparency and to have sufficient scratch resistance.
0 nm or less is preferable, 50 nm or less is more preferable,
20 nm or less is more preferable. Further, in order to stably disperse the particles, the thickness is preferably 1 nm or more. The average particle size can be measured by observation with an electron microscope, BET method converted from specific surface area measurement, or the like.

The proportion of the indium oxide-based fine particles in the entire crosslinked film (that is, the total mass of the non-solvent components in the coating material for forming a crosslinked film described later) is determined in order to realize a sufficient antistatic property. It is preferably at least 10% by mass, more preferably at least 20% by mass, and preferably at most 60% by mass, more preferably at most 50% by mass, in order to realize good transparency and solvent resistance. (Cross-Linking Reactive Component) In the present invention, the coating material for forming a cross-linked film contains at least the above-described indium oxide-based fine particles and a cross-linking reactive component. The crosslinking reactive component is not particularly limited as long as it has at least two polymerizable functional groups in its molecule. In a cross-linking reactive compound having at least two polymerizable functional groups in a molecule, the residue that binds each of these polymerizable functional groups is preferably a hydrocarbon or a derivative thereof, and in the molecule, It preferably contains one or more of an ether bond, a thioether bond, an ester bond, an amide bond, a urethane bond and the like. If necessary, two or more of the above crosslinking reactive compounds can be used in combination.

In the present invention, a monomer copolymerizable with the above-mentioned crosslinking reactive compound may be used in combination, but the content of the copolymerizable monomer is based on the mass of the crosslinking reactive compound. Is preferably 50% by mass or less. (Silicon Compound) In the present invention, for example, a thermosetting silicone compound can be used as the crosslinking reactive compound. In this case, it is preferable to use a silicon-based compound represented by the following general formula.

R _n SiX _(4-n) (where R is an alkyl group such as a methyl group, an ethyl group or a butyl group; a phenyl group; a vinyl group; an unsaturated hydrocarbon group such as an allyl group; a (meth) acryl group An epoxy group, an amino group, etc. X represents an alkoxy group having 1 to 4 carbon atoms, an acyl group such as an acetyl group, or a halogen group, and n represents 0 to 3;
Indicates an integer. In the present invention, a hydrolyzate of a silicon-based compound,
A compound obtained by hydrolyzing or partially hydrolyzing a mixture of a silicon-based compound and colloidal silica can be used as a crosslinking reactive compound. In such a case, as a method of curing the crosslinking reactive compound, a method of curing by performing condensation polymerization at a temperature of 80 ° C. or higher is preferable. (Cross-linking reactive compound having (meth) acryloyloxy group) The above-mentioned cross-linking reactive component has at least 2
It is preferable to include a crosslinking reactive compound having two (meth) acryloyloxy groups. in this way,
A paint containing a cross-linking reactive compound having a (meth) acryloyloxy group is easy to give a coating excellent in transparency and scratch resistance and also excellent in adhesion to an acrylic resin plate as a substrate. Therefore, it is preferable. Here, “(meth) acryl” means “acryl” and / or “methacryl”. In the present invention, if necessary, two or more of the above-mentioned crosslinking reactive compounds having two or more (meth) acryloyloxy groups in the molecule can be used in combination.

In the crosslinking reactive compound having at least two (meth) acryloyloxy groups in a molecule which can be suitably used in the present invention, the residue binding each (meth) acryloyloxy group is a hydrocarbon. Or a derivative thereof, and the molecule preferably contains an ether bond, a thioether bond, an ester bond, an amide bond, a urethane bond, or the like.

[0015] The main examples of these compounds are: esterified products obtainable from one mole of polyhydric alcohol and two or more moles of (meth) acrylic acid or a derivative thereof; Listed are linear esterified compounds having two or more (meth) acryloyloxy groups in one molecule, which can be obtained from carboxylic acid or its anhydride and (meth) acrylic acid or a derivative thereof. Can be. (Esterified product) Examples of the ester obtained from 1 mol of the polyhydric alcohol and 2 mol or more of (meth) acrylic acid include diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate,
Tetraethylene glycol di (meth) acrylate,
1,4-butanediol di (meth) acrylate, 1,
6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate Acrylate, glycerin tri (meth) acrylate, the following general formula (1) [In the formula, n is an integer of 1 to 4, and at least three of X ^{1 to} X ⁶ represent a (meth) acryloyl group, and the others represent hydroxyl groups. ], For example, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol tetra (meth) acrylate Examples include acrylate, tripentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, and tripentaerythritol hepta (meth) acrylate. (Linear Ester) A linear ester having two or more (meth) acryloyloxy groups in one molecule obtained from a polyhydric alcohol and a polycarboxylic acid or an anhydride thereof and (meth) acrylic acid. In the compound, a preferable combination of a polyhydric alcohol, a polycarboxylic acid or an anhydride thereof, and (meth) acrylic acid is malonic acid / trimethylolethane / (meth) acrylic acid, malonic acid / trimethylolpropane / ( (Meth) acrylic acid, malonic acid /
Glycerin / (meth) acrylic acid, malonic acid / pentaerythritol / (meth) acrylic acid, succinic acid / trimethylolethane / (meth) acrylic acid, succinic acid / trimethylolpropane / (meth) acrylic acid, succinic acid /
Glycerin / (meth) acrylic acid, succinic acid / pentaerythritol / (meth) acrylic acid, adipic acid / trimethylolethane / (meth) acrylic acid, adipic acid /
Trimethylolpropane / (meth) acrylic acid, adipic acid / glycerin / (meth) acrylic acid, adipic acid /
Pentaerythritol / (meth) acrylic acid, glutaric acid / trimethylolethane / (meth) acrylic acid, glutaric acid / trimethylolpropane / (meth) acrylic acid, glutaric acid / glycerin / (meth) acrylic acid, glutaric acid / penta Erythritol / (meth) acrylic acid, sebacic acid / trimethylolethane / (meth) acrylic acid, sebacic acid / trimethylolpropane / (meth) acrylic acid, sebacic acid / glycerin / (meth) acrylic acid, sebacic acid / pentaerythritol / (Meth) acrylic acid, fumaric acid / trimethylolethane /
(Meth) acrylic acid, fumaric acid / trimethylolpropane / (meth) acrylic acid, fumaric acid / glycerin / (meth) acrylic acid, fumaric acid / pentaerythritol /
(Meth) acrylic acid, itaconic acid / trimethylolethane / (meth) acrylic acid, itaconic acid / trimethylolpropane / (meth) acrylic acid, itaconic acid / glycerin / (meth) acrylic acid, itaconic acid / pentaerythritol / ( (Meth) acrylic acid, maleic anhydride / trimethylolethane / (meth) acrylic acid, maleic anhydride / trimethylolpropane / (meth) acrylic acid, maleic anhydride / glycerin / (meth) acrylic acid, maleic anhydride / pentane Erythritol / (meth) acrylic acid and the like can be mentioned. (Monomer Copolymerizable with Cross-Linking Reactive Compound) As a monomer which can be suitably used in the present invention, a monomer copolymerizable with a cross-linking reactive compound having two or more (meth) acryloyloxy groups in a molecule. Are tolylene diisocyanate, xylylene diisocyanate, diphenyl methane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexyl methane diisocyanate, toluylene diisocyanate, diphenyl methane diisocyanate, or diisocyanates obtained by hydrogenating aromatic isocyanates among these diisocyanate compounds. Compounds (eg, diisocyanate compounds such as hydrogenated xylylene diisocyanate and hydrogenated diphenylmethane diisocyanate), triphenylmethane triisocyanate A divalent or trivalent polyisocyanate compound such as dimethyl carbonate or dimethylenetriphenyl triisocyanate or a polyisocyanate compound obtained by multiplying a diisocyanate compound; and an acrylic monomer having active hydrogen, for example, 2-hydroxyethyl ( (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-methoxypropyl (meth) acrylate, N-methylol (meth) acrylamide, N-hydroxy (meth) acrylamide, 1,2,3-propanetriol -1,3-di (meth) acrylate, 3-acryloyloxy-2-
Urethane (meth) acrylate obtained by reacting hydroxypropyl (meth) acrylate or the like in a conventional manner;
Alternatively, poly [(meth) acryloyloxyethyl] isocyanurate such as di (meth) acrylate and tri (meth) acrylate of tris (2-hydroxyethyl) isocyanuric acid, and a known epoxy polyacrylate may be used.

Examples of other copolymerizable monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, propyl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate. , 2-hydroxypropyl (meth) acrylate,
Examples thereof include 4-hydroxybutyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethyl (meth) acrylamide, and dimethylaminopropyl (meth) acrylamide.

If necessary, two or more of the above-mentioned copolymerizable monomers can be used in combination. (Matrix component) The coating material for forming a crosslinked film of the present invention may contain a silane compound, colloidal silica and the like. As the silane compound, a (meth) acryl-functional silane compound is preferable. (Coating method) The above-mentioned paint for forming a crosslinked film is optionally coated with a solvent such as methanol, ethanol, isopropanol, isobutanol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, methyl acetate, ethyl acetate, and butyl acetate. It may be used after dilution.

In the present invention, the method for applying the coating for forming a crosslinked film containing indium oxide-based fine particles is not particularly limited, and examples thereof include brush coating, bar coating, flow coating, spray coating, knife coating, roll coating, and die coating. Can be used. In the present invention, the thickness of the crosslinked film containing the indium oxide-based fine particles is preferably 0.5 μm or more, more preferably 1 μm or more, in order to realize sufficient antistatic ability and surface hardness. Further, in order to suppress problems such as generation of cracks in the crosslinked film and chipping of the crosslinked film when cutting the acrylic resin laminate, 50
μm or less is preferable, and 30 μm or less is more preferable. (Crosslinking method) In the present invention, a method of crosslinking and curing the crosslinking reactive compound in a coating for forming a crosslinking coating containing indium oxide-based fine particles and a crosslinking reactive compound to form a crosslinked coating is not particularly limited. , A thermal polymerization method, a photopolymerization method using ultraviolet irradiation, and the like. Except when the above-mentioned thermosetting silicone compound is used as the cross-linking reactive compound, the cross-linking and curing by irradiation with ultraviolet rays can be suitably used for the reason that the ultraviolet curing apparatus is simple and the like. (Photosensitizer) When crosslinking and curing with ultraviolet light,
If necessary, a photosensitizer having a sensitizing effect in a wavelength region of 400 nm or less may be added. The amount of the photosensitizer to be added is preferably 0.1 parts by mass or more based on 100 parts by mass of the crosslinking reactive compound in order to realize a sufficient curing speed and curing strength, and to reduce the weather resistance. For suppression, the amount is preferably 10 parts by mass or less.

Examples of the photosensitizer include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, acetoin, butyroin, toluoin, benzyl, benzophenone, p-methoxybenzophenone,
2,2-diethoxyacetophenone, α, α-dimethoxy-α-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4′-
Carbonyl compounds such as bis (dimethylamino) benzophenone and 2-hydroxy-2-methyl-1-phenylpropan-1-one; sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; 2,4,6-trimethyl Benzoyldiphenylphosphine oxide, benzoyldiethoxyphosphine oxide and the like can be exemplified. (Additives) To the coating for forming a crosslinked film in the present invention, various additives conventionally used may be added in appropriate amounts. Examples of the additive include a surfactant, a leveling agent, a dye, a pigment, an antioxidant, an ultraviolet absorber, a stabilizer, a flame retardant, and a plasticizer. (Method for Polymerizing Acrylic Resin Raw Material) In the present invention, as described above, a paint for forming a crosslinked film containing at least indium oxide-based fine particles and a crosslinking reactive compound is used.
After applying to the inner surface of at least one mold and forming a cross-linked film by cross-linking and polymerizing the cross-linking reactive compound, in a mold including at least a part of the mold in which the cross-linked film is formed on the inner surface, Acrylic resin raw material can be polymerized.

The method for polymerizing the acrylic resin raw material is not particularly limited, and examples thereof include a so-called cast polymerization method in which the acrylic resin raw material is injected into a glass mold and polymerized and cured. (Cast Polymerization) In an embodiment in which cast polymerization is used in the present invention, for example, a coating for forming a crosslinked film containing indium oxide-based fine particles and a crosslinking reactive compound is applied to the inner surface of at least one mold, and the crosslink polymerization is performed. After curing and forming a crosslinked film having antistatic ability in advance, it is preferable to perform cast polymerization of the acrylic resin raw material inside a mold constituted by the same mold.

The members constituting the mold are not particularly limited, but for example, a glass plate can be used. In this case, for example, soft polyvinyl chloride, ethylene-vinyl acetate copolymer, polyethylene, ethylene-methyl methacrylate copolymer or the like is sandwiched as a gasket between two glass plates having excellent surface smoothness, and a clamp, etc. By fixing the mold, it is possible to assemble a mold including at least a molding die. In this case, two glass plates,
The acrylic resin material is injected into a space formed by the thickness of the gasket.

By using a mold having minute irregularities on at least a part of the inner surface of the mold, an acrylic resin laminate in which at least a part of the crosslinked film has minute irregularities can be obtained. By attaching a film having a minute uneven shape on the surface and not swelling or dissolving to the coating for forming a crosslinked film to a mold, and applying a raw material for forming a crosslinked film on the uneven surface, at least the crosslinked film is formed. It is also possible to obtain an acrylic resin laminate having a partly fine uneven shape. By imparting at least a part of the crosslinked film with a fine uneven shape, it is possible to reduce the reflection of light rays on the surface of the crosslinked film of the obtained acrylic resin laminate, and it is possible to prevent glare on the surface.

As a method of continuously performing cast polymerization,
As described in JP-B-47-33495, a method of casting and polymerizing an acrylic resin material between two steel belts is known.
It can be applied to such continuous polymerization. In this case, for example, the acrylic resin laminate of the present invention may be formed by forming a crosslinked film on the surface of the steel belt. (Acrylic resin raw material) The acrylic resin raw material that can be used in the present invention is not particularly limited. For example, a monomer mainly containing (meth) acrylic acid esters, a polymer of this monomer and a monomer And a syrup consisting of In addition, examples of the acrylic resin include homopolymers and copolymers containing (meth) acrylic acid esters as main monomer components. In addition, as an ester of (meth) acrylic acid, methyl methacrylate can be illustrated.

For example, when methyl methacrylate is the main monomer component, the comonomer components include acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate and butyl acrylate; And methacrylic acid esters such as cyclohexyl acid, phenyl methacrylate, and benzyl methacrylate; and aromatic vinyl compounds such as styrene, α-methylstyrene, and p-methylstyrene. When methyl methacrylate partially contains a polymer, the polymer may be dissolved in methyl methacrylate, or methyl methacrylate may be partially polymerized. (Functional Thin Film) In the acrylic resin laminate obtained according to the present invention, a functional thin film can be provided as necessary in addition to the indium oxide crosslinked film. For example, an antireflection film, which is a type of a functional thin film, can be formed on the above-described indium oxide crosslinked film. The method of forming the antireflection film is not particularly limited,
A method using a coating for forming an antireflection film, such as "CYTOP" manufactured by CYTOP Co., Ltd. and "OPSTAR" manufactured by JSR Corporation; a physical vapor deposition method such as a vapor deposition method or a sputtering method. (Physical Properties of Acrylic Resin Laminate) Since a crosslinked film containing indium oxide-based fine particles is formed on the surface of the acrylic resin laminate of the present invention, the acrylic resin laminate has transparency, scratch resistance, and antistatic property. Excellent in nature. For this purpose, the surface resistivity can be preferably 1 × 10 ¹² Ω or less, more preferably 1 × 10 ¹¹ Ω or less; the total light transmittance is preferably 80% or more. Can be done;
Haze can be preferably 5% or less, more preferably 2% or less.

Further, since the crosslinked film in the present invention is a crosslinked film containing indium oxide-based fine particles, even if the film thickness is set to a value necessary for realizing sufficient scratch resistance and antistatic property, the crosslinked film may not be colored. The occurrence of a defect is suppressed. For the reasons described above, the acrylic resin laminate of the present invention can be suitably used as a front plate of various displays such as a CRT, a liquid crystal television, and a projection television.

[0026]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Unless otherwise specified, all reagents used were commercially available good products. [Evaluation method] (A) Regarding the surface resistance value, use a super insulation resistance meter (TOA).
Made, ULTRA MEGOHMMETER MODEL
Using SM-10E), the surface resistivity (Ω) after one minute at an applied voltage of 500 V was measured at a measurement temperature of 23 ° C. and a measurement humidity of 50%. In addition, what was previously conditioned at 23 ° C. and 50% relative humidity for one day was used as a sample for measurement.

(A) The haze is Haze Meter NDH20 manufactured by Nippon Denshoku according to JIS K 7105.
00. (C) Scratch resistance was evaluated based on the change in haze before and after the abrasion test (Δ haze). That is, # 0
A 25.4 mm diameter circular pad with steel wool of 00 was placed on the coating side of the sample, and the sample was reciprocated 100 times with a load of 9.8 N at a distance of 20 mm 100 times, before and after the haze. The difference between the values was determined by the following equation (1): [Δ haze (%)] = [haze value after abrasion (%)] − [haze value before abrasion (%)] (1).

(D) The total light transmittance (%) is calculated according to JIS K
According to 7105, Haze METER manufactured by Nippon Denshoku
It was measured by NDH2000. Example 1 In a beaker, 50 parts by mass of dipentaerythritol hexaacrylate, 50 parts by mass of trimethylolpropane triacrylate, 5 parts by mass of 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, manufactured by Ciba Geigy), and ethylene glycol mono 450 parts by mass of ethyl ether was added, and the mixture was stirred with a stirrer to dissolve each component in ethylene glycol monoethyl ether. Then, while stirring the obtained mixture, tin-doped indium oxide-based fine particles (manufactured by C-I-Kasei Co., Ltd., particle size: 30 nm, hereinafter abbreviated as “ITO”) 100
A mass part was added and dispersed. This mixture was charged into a ball mill and dispersed for 8 hours to obtain a photocurable paint.

The coating material thus obtained was applied to a 610 mm × 460 mm, 6 mm thick glass plate using a bar coater. After drying this glass plate in a hot air drying oven at 50 ° C. for 5 minutes, under a high-pressure mercury lamp with an output of 120 W,
The glass plate was passed at a distance of 200 mm at a speed of 1.6 m / min, and a 5 μm-thick crosslinked film containing indium oxide-based fine particles was formed on one surface.

Two glass plates having a crosslinked indium oxide film prepared by the above method are prepared, opposed to each other so that the crosslinked film is on the inside, the periphery is sealed with a soft vinyl chloride gasket, and the periphery is clamped. To prepare a cell for casting polymerization. In the obtained cell, 100 parts by mass of a syrup composed of 20% by mass of a methyl methacrylate polymer and 80% by mass of methyl methacrylate, 0.05 part by mass of azobisdimethylvaleronitrile, and sodium salt of dioctyl sulfosuccinate 0.005 parts by mass of a raw material, and then in a water bath at 80 ° C. for 1 hour and then 1 hour.
The polymerization reaction was performed in an air oven at 20 ° C. for 1 hour. After cooling the cell, a 2 mm-thick resin plate formed by polymerization was peeled off from the glass plate for casting polymerization to obtain an acrylic resin laminate having an indium oxide crosslinked film on both surfaces.

This acrylic resin laminate had a total light transmittance of 85%, a haze of 1.5%, a surface resistivity of 1 × 10 ⁷ Ω, and a Δ haze of 0.1% after a steel wool abrasion test. That is, it was found that the obtained acrylic resin laminate was excellent in transparency, antistatic property and scratch resistance. Example 2 An acrylic resin laminate having a crosslinked coating containing ITO fine particles on both surfaces was obtained in the same manner as in Example 1 except that the amount of ITO was changed to 43 parts by mass.

This acrylic resin laminate had a total light transmittance of 88%, a haze of 1.0%, a surface resistivity of 1 × 10 ¹⁰ Ω, and a Δ haze of 0.1% after a steel wool abrasion test.
It turned out to be excellent in transparency, antistatic property and scratch resistance. Comparative Example 1 An acrylic resin laminate having a crosslinked film on both surfaces was obtained in the same manner as in Example 1 except that the ITO fine particles were not added.

Although the obtained acrylic resin laminate had excellent scratch resistance, it did not contain ITO fine particles, and thus did not have any antistatic performance. Comparative Example 2 An acrylic resin having a crosslinked coating containing ATO fine particles on both surfaces in the same manner as in Example 1 except that tin oxide (hereinafter abbreviated as ATO) fine particles doped with antimony were used instead of ITO. A laminate was obtained.

The obtained acrylic resin laminate was colored for ATO fine particles, and had a total light transmittance of 70%.

[0035]

In the acrylic resin laminate obtained according to the present invention, a crosslinked film containing indium oxide-based fine particles is formed on the surface of the acrylic resin plate.
Not only the coloring of the acrylic resin laminate is suppressed, but also sufficient antistatic properties, excellent scratch resistance and transparency can be realized.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29K 105: 16 B29K 105: 16 105: 24 105: 24 105: 32 105: 32 505: 00 505: 00 B29L 9:00 B29L 9:00 C08L 33:00 C08L 33:00 F-term (reference) 4F006 AA22 AB43 AB54 AB74 BA02 BA07 CA05 CA08 DA05 EA04 4F100 AA17A AA17C AA33 AG00 AK24B BA03 BA06 BA10A BA10C CC00A CC00C DD01A DD01C DE01E EJ05A EJ05C EJ54 GB41 JB12A JB12C JG03 JK12 JN01 YY00A YY00C 4F204 AA20 AB04 AD11 AE10 AF01 AG03 AH73 EA03 EB01 EB13 EB24 EB29 EF01 EF05 EF27 EF49

Claims (4)

[Claims] 1. A coating for forming a crosslinked film containing indium oxide-based fine particles and a crosslinking reactive compound is applied to the inner surface of at least one mold, and the crosslinking reactive compound is crosslinked and polymerized to form the inner surface. A step of forming a crosslinked film thereon; a step of injecting an acrylic resin raw material into a mold including at least a part of the mold having the crosslinked film formed on the inner surface; and a step of polymerizing the acrylic resin material And a step of separating the acrylic resin laminate from the mold. 2. The method for producing an acrylic resin laminate according to claim 1, wherein the crosslinking reactive compound contains a crosslinking reactive compound having at least two (meth) acryloyloxy groups in a molecule. . 3. The indium oxide-based fine particles have an average particle size of 1 nm or more and 100 nm or less, and the proportion of the indium oxide-based fine particles in the non-solvent component in the coating material for forming a crosslinked film is 10% by mass or more. The method for producing an acrylic resin laminate according to claim 1, wherein the content is 60% by mass or less. 4. The method for producing an acrylic resin laminate according to any one of claims 1 to 3, wherein a molding die having a fine unevenness formed on at least a part of an inner surface thereof is used.