JP4736387B2 - Laminated body having scratch resistance and antireflection properties - Google Patents

Description

  The present invention relates to a laminate in which a scratch-resistant layer and an antireflection layer are formed in this order on the surface of a transparent substrate.

  Conventionally, as one method for imparting antireflection performance to a transparent substrate such as glass or resin, a curable composition containing silica fine particles and a cationic polymerizable compound is used, and an antireflection layer made of the cured product is used as a base. It is known to form on the surface of a material. For example, Japanese Patent Laid-Open No. 6-1557819 (Patent Document 1) discloses the use of an epoxy compound or a vinyl ether compound as the cationic polymerizable compound. Japanese Patent Laid-Open No. 2003-145682 (Patent Document 2) discloses that an oxetane compound is used as the cationic polymerizable compound. Furthermore, JP 2003-147268 A (Patent Document 3) discloses that an oxetane compound and an epoxy compound are used in combination as the cationic polymerizable compound.

Japanese Patent Laid-Open No. 6-1557819 JP 2003-145682 A JP 2003-147268 A

  Antireflective layers made of cationically polymerizable compounds as described in these patent documents generally have high hardness and good scratch resistance, but for example, outdoor applications with many floating matters causing scratches, scratches, etc. In particular, for display applications that are problematic, further improvement in scratch resistance is required. In order to improve the scratch resistance of the antireflection layer, it is effective to form a scratch resistance layer usually referred to as a hard coat layer on the surface of the substrate, and to form an antireflection layer thereon. Depending on the type of the scratch-resistant layer, the adhesion between the antireflection layer and the scratch-resistant layer may be insufficient, or the scratch resistance of the anti-reflection layer may not be sufficiently improved. Therefore, an object of the present invention is a laminate in which a scratch-resistant layer and an antireflection layer are formed in this order on the surface of a transparent substrate, and has excellent adhesion between the antireflection layer and the scratch resistance layer, and An object of the present invention is to provide a laminate having an antireflection layer excellent in scratch resistance.

  As a result of intensive studies, the inventors of the present invention formed a scratch-resistant layer using a specific curable composition on the surface of a transparent substrate, and a curable composition containing a cationically polymerizable compound and silica fine particles thereon. It has been found that the above object can be achieved by forming an antireflection layer using the composition, and the present invention has been completed. That is, in the present invention, a scratch-resistant layer and an antireflection layer are formed in this order from the substrate surface side on the surface of the transparent substrate, and the scratch-resistant layer has at least two radically polymerizable molecules in the molecule. A composition containing 50 to 99 parts by weight of a compound having a functional group and 1 to 50 parts by weight of a compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule is cured, and the antireflection layer is The present invention provides a laminate comprising a cured composition comprising a compound having a cationically polymerizable functional group in the molecule and silica fine particles.

  In the laminate of the present invention, the scratch-resistant layer and the antireflection layer are formed in this order on the surface of the transparent substrate, and the adhesion between the antireflection layer and the scratch resistance layer is excellent. Excellent scratch resistance.

  In the laminate of the present invention, a scratch-resistant layer and an antireflection layer are formed in this order from the surface side of the transparent substrate on the surface of the transparent substrate. A transparent resin is usually used for the transparent substrate. Examples thereof include polymethyl methacrylate resin, polycarbonate resin, polystyrene resin, methyl methacrylate-styrene copolymer resin, acrylonitrile-styrene copolymer resin, and triacetyl cellulose resin. Etc. In particular, methyl methacrylate-styrene copolymer resin is small in expansion and contraction due to moisture absorption, and is suitable as a base material for an antireflection plate.

  Although the shape of a transparent base material is not specifically limited, A sheet | seat and a film are typical. The substrate surface may be a flat surface or a curved surface such as a convex lens or a concave lens. Moreover, fine irregularities may be provided.

  A scratch-resistant layer is provided on the surface of the transparent substrate. The scratch-resistant layer may be formed on the entire surface of the substrate, or may be formed on a part thereof. For example, if the transparent substrate is a sheet or film, it may be formed on both sides or may be formed on one side.

  Curable composition comprising a compound having at least two radical polymerizable functional groups in a molecule and a compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule as a material for the scratch-resistant layer [Hereinafter, this composition may be referred to as a curable composition (1)], and the cured product constitutes an abrasion-resistant layer.

  The compound having at least two radical polymerizable functional groups in the molecule, which is one of the essential components of the curable composition (1), is generally called a polyfunctional radical polymerizable compound. As a typical example, a group containing a radical polymerizable carbon-carbon double bond such as a (meth) acryloyloxy group or a maleimide group is typical. In particular, a polyfunctional (meth) acrylate compound which is a compound having at least two (meth) acryloyloxy groups in the molecule is preferably used. The (meth) acryloyloxy group refers to a methacryloyloxy group or an acryloyloxy group, and the (meth) acrylate refers to a methacrylate or an acrylate. In addition, in the present specification, “(meth) acryloyl” The same applies to “(meta)”.

  Examples of polyfunctional (meth) acrylate compounds include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and trimethylol. Propane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, glycerin tri (meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tri- or tetra- (meth) acrylate, dipentaerythritol tri-, tetra -, Penta- or hexa- (meth) acrylate, tris (meth) acryloyloxyethyl isocyanurate, 2,2-bis [4- (acryloyloxydiethoxy) phenyl] propane A poly (meth) acrylate of a polyhydric alcohol; a phosphazene-based (meth) acrylate compound in which a (meth) acryloyloxy group is introduced into the phosphazene ring of a cyclic phosphazene compound; a poly having at least two isocyanato groups in the molecule A urethane (meth) acrylate compound obtained by reacting an isocyanate compound with a compound in which some hydroxyl groups of the polyol are (meth) acryloylated; a carboxylic acid halide having at least two halocarbonyl groups in the molecule; Polyester (meth) acrylate compounds obtained by reacting a compound in which some hydroxyl groups of the polyol are (meth) acryloylated are used, and two or more of them can be used as necessary.

  Some polyfunctional (meth) acrylate compounds are commercially available in a mixed state with solvents, polymerization initiators, other additives, etc., and can be used as examples of such commercially available products. "Aronix UV3701" from Toagosei Co., Ltd., "Unidic 17-824-9" from Dainippon Ink and Chemicals, "UVHC8558" from GE Toshiba Silicone, Inc.

  In the compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule, which is another essential component of the curable composition (1), examples of the cationic polymerizable functional group include a vinyl ether group, an epoxy group, And oxetane ring. Examples of the radical polymerizable functional group are the same as the examples of the radical polymerizable functional group in the compound having at least two radical polymerizable functional groups in the molecule described above. In addition, a compound having at least two radical polymerizable functional groups in the molecule and a compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule do not have a cationic polymerizable functional group. The latter is distinguished in terms of constitution, and the latter may have a plurality of radically polymerizable functional groups in the molecule or may have a plurality of cationically polymerizable functional groups in the molecule.

  Examples of compounds having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule include vinyloxyethoxyethyl (meth) acrylate, glycidyl (meth) acrylate, (epoxycyclohexyl) methyl (meth) acrylate, and 3-ethyl. -3- (Meth) acryloyloxymethyl oxetane, glycidyl vinyl benzyl ether and the like can be mentioned, and two or more of them can be used as necessary.

  In the curable composition (1), the amount ratio between the compound having at least two radical polymerizable functional groups in the molecule and the compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule is Based on the total amount, the former is 50 to 99% by weight and the latter is 1 to 50% by weight, and preferably the former is 70 to 95% by weight and the latter is 5 to 30% by weight. When the latter is too small, the adhesion between the scratch-resistant layer and the antireflection layer is not sufficient, and when the latter is too large, the scratch resistance of the scratch-resistant layer and the antireflection layer thereon is lowered.

  The curable composition (1) preferably contains conductive fine particles. As a result, the formed scratch-resistant layer contains conductive fine particles and is imparted with antistatic performance, so that generation of static electricity is suppressed and dust is less likely to adhere. In addition, the adhesion between the scratch-resistant layer and the antireflection layer provided thereon is improved.

  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 tin oxide. The particle size and amount of the conductive fine particles are appropriately selected in consideration of the balance between transparency and antistatic properties. The average particle size is preferably 0.001 to 0.1 μm. If the particle size is too small, industrial production is difficult. If the particle size is too large, the transparency of the scratch-resistant layer is lowered. The addition amount is based on the total amount of the compound having at least two radical polymerizable functional groups in the molecule, the compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule, and conductive fine particles. 1 to 50% by weight is preferable. If the amount is too small, it is difficult to obtain an antistatic effect, and if the amount is too large, the scratch resistance is lowered or the film formability is lowered, which is not preferable.

  The curable composition (1) may contain additives such as a stabilizer, an antioxidant, and a colorant.

  As the polymerization initiator for curing the curable composition (1), a compound that generates radicals when irradiated with ultraviolet rays is preferably used. Examples of such radical polymerization initiators include benzyl, benzophenone and derivatives thereof, thioxanthones, benzyldimethylketals, α-hydroxyalkylphenones, hydroxyketones, aminoalkylphenones, acylphosphine oxides, and the like. Two or more of them can be used as necessary.

  Examples of commercially available products of these radical polymerization initiators include “IRGACURE 651”, “IRUGACURE 184”, “IRUGACURE 907”, “IRUGACURE 500” and “DAROCURE 1173” from Ciba Specialty Chemicals, “KAYACURE BP-100” and “KAYACURE DETX-S” of Nippon Kayaku Co., Ltd., “High Cure OBM” of Kawaguchi Pharmaceutical Co., Ltd., “QUANTACURE ITX” of Shell Chemical Co., Ltd., “LUCIRIN TPO” of BASF Corporation And “ESACURE EB3” of Nippon Siebel Hegner Co., Ltd.

  The radical polymerization initiator is based on a total amount of 100 parts by weight of a compound having at least two radical polymerizable functional groups in the molecule and a compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule. Usually, it is added at a ratio of about 0.1 to 20 parts by weight, preferably about 0.5 to 10 parts by weight. If the amount of this initiator is too small, the ultraviolet polymerizability is not sufficiently exhibited, and even if the amount is too large, the effect of increasing the amount is not recognized, which is economically disadvantageous, and the scratch-resistant layer. This is not preferable because optical characteristics may be deteriorated.

  The scratch-resistant layer is preferably formed by applying and curing the curable composition (1) on the surface of the transparent substrate. For this purpose, the curable composition (1) is formed as a paint. There is a need to. This paint comprises a compound having at least two radical polymerizable functional groups in the molecule, a compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule, and other components as needed in a solvent. It is desirable to prepare by dissolving or dispersing.

  The solvent is used to adjust the concentration and viscosity of the paint, the layer thickness after curing, and the like. The solvent to be used may be appropriately selected. For example, methanol, ethanol, 1-propanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, alcohols such as t-butyl alcohol, 2-ethoxyethanol, Alkoxy alcohols such as 2-butoxyethanol, 3-methoxypropanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, ketols such as diacetone alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone Ketones, aromatic hydrocarbons such as toluene and xylene, and esters such as ethyl acetate and butyl acetate. The amount of the solvent used is appropriately selected according to the material, shape, coating method, layer thickness of the target scratch-resistant layer, etc., but usually at least two radical polymerizable functional groups in the molecule. The total amount of the compound having a group, the compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule, and the total amount of conductive fine particles used as necessary is in the range of about 20 to 10,000 parts by weight.

  A coating film made of the curable composition (1) is formed by applying such paint to the surface of the transparent substrate. The coating is applied by a method such as a micro gravure coating method, a roll coating method, a dipping coating method, a flow coating method, a spin coating method, a die coating method, a cast transfer method, or a spray coating method.

Next, the scratch-resistant layer can be formed by irradiating ultraviolet rays to cure the coating film. The irradiation time of ultraviolet rays is usually about 0.1 to 60 seconds, and the irradiation temperature is usually about 10 to 40 ° C. Moreover, the irradiation energy of ultraviolet rays is about 50-3000 mJ / cm < ² > normally, Preferably it is about 100-700 mJ / cm < ² >. When the irradiation amount of ultraviolet rays is too small, curing becomes insufficient and the strength of the scratch-resistant layer is lowered. On the other hand, if the amount of UV irradiation is too large, the scratch-resistant layer and the base material are deteriorated, and there is a possibility that optical properties and mechanical properties will be lowered.

  When the coating material contains a solvent, the ultraviolet ray may be irradiated while the coating film contains the solvent, or may be irradiated after the solvent is volatilized. When the solvent is volatilized, it may be left at room temperature or may be dried by heating at about 30 to 100 ° C. The drying time is appropriately selected according to the material and shape of the substrate, the coating method, the layer thickness of the target scratch-resistant layer, and the like. After forming the scratch-resistant layer by ultraviolet irradiation, a heat treatment may be further performed in order to make the scratch-resistant layer stronger. The heating temperature and time are appropriately selected, but are usually about 50 to 120 ° C. and about 30 minutes to 24 hours.

  The layer thickness of the formed scratch-resistant layer is usually 0.5 to 20 μm, preferably 1 to 10 μm. If the layer thickness is too small, it will be difficult to exhibit properties as a scratch-resistant layer, and if the layer thickness is too large, problems such as cracking may occur, which is not preferable.

  An antireflection layer is formed on the scratch-resistant layer formed as described above. As the material for the antireflection layer, a curable composition containing a compound having a cationic polymerizable functional group in the molecule and silica fine particles is used [hereinafter, this composition is referred to as a curable composition (2). There is an antireflection layer by the cured product.

  The compound having a cationically polymerizable functional group in the molecule, which is one of the essential components of the curable composition (2), is generally called a cationically polymerizable compound, and is a single compound having one cationically polymerizable functional group in the molecule. It may be a functional one or a polyfunctional one having a plurality. Examples of this cationic polymerizable functional group include those of the cationic polymerizable functional group in the compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule, which is an essential component of the curable composition (1) described above. Similar to the example. In particular, an oxetane compound that is a compound having at least one oxetane ring in the molecule and an epoxy compound that is a compound having at least one epoxy group in the molecule are preferably used.

  Preferable examples of the oxetane compound include those represented by the following formulas (I) to (III).

In the formula, R ¹ represents a hydrogen atom, a fluorine atom, an alkyl group, a fluoroalkyl group, an allyl group, an aryl group or a furyl group, m represents an integer of 1 to 4, and Z represents an oxygen atom or a sulfur atom. , R ² represents a 1 to 4 valent organic group depending on the value of m, n represents an integer of 1 to 5, p represents an integer of 0 to 2, and R ³ represents hydrogen or an inactive monovalent group. R ⁴ represents a hydrolyzable functional group. When R ¹ , Z, R ³ or R ⁴ appears multiple times in one molecule, they may be the same or different.

In the formulas (I) to (III), when R ¹ is an alkyl group, the carbon number thereof can be about 1 to 6, specifically, a methyl group, an ethyl group, a propyl group, a butyl group, and the like. Can be mentioned. The fluoroalkyl group can also have about 1 to 6 carbon atoms. Furthermore, the aryl group is typically a phenyl group or a naphthyl group, and these may be substituted with other groups.

Further, the organic group represented by R ² in the formula (I) is not particularly limited. For example, when m is 1, an alkyl group, a phenyl group, etc., and when m is 2, 12 linear or branched alkylene groups, linear or branched poly (alkyleneoxy) groups, 1,2-phenylene groups, 1,3-phenylene groups, 1,4-phenylene groups, 4,4 ′ -When m is 3 or 4 in the biphenylene group or the like, a similar polyfunctional group is exemplified.

The inactive monovalent organic group represented by R ³ in the formula (III) typically includes an alkyl group having 1 to 4 carbon atoms, and a hydrolyzable function represented by R ^4. Examples of the group include an alkoxy group having 1 to 5 carbon atoms including a methoxy group and an ethoxy group, and a halogen atom such as a chlorine atom and a bromine atom.

  Among oxetane compounds, a compound having a silyl group in the molecule or a hydrolysis condensate thereof is preferably used. In particular, a silsesquioxane compound (network polysiloxane compound) obtained by hydrolytic condensation of a compound represented by the formula (III) in the presence of alkali and water has a plurality of oxetane rings in the molecule. In order to give a hard antireflection layer, it is suitable as a material used in the present invention.

  Preferred examples of the epoxy compound include phenyl glycidyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, vinylcyclohexene dioxide, 1,2,8,9-diepoxy limonene, 3,4-epoxycyclohexyl methyl 3 ′, Examples thereof include 4'-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexyl) adipate, and the like.

  The compound having a cationically polymerizable functional group in the molecule can be used alone or in combination of a plurality of compounds. For example, when an oxetane compound and an epoxy compound are used in combination, curing of the oxetane compound is further accelerated, and a harder antireflection film can be obtained, which is advantageous.

  As the fine silica particles, which are another essential component of the curable composition (2), those having an average particle diameter in the range of 5 nm to 10 μm, particularly 5 nm to 100 nm are preferably used. Silica fine particles having a very small particle size are difficult to produce industrially, and if the particle size is too large, optical performance such as transparency of the antireflection layer is lowered, which is not preferable. Further, porous silica fine particles may be used as the silica fine particles. Porous silica has a refractive index of about 1.2 to 1.4, which is lower than the refractive index of normal silica 1.46, and is more preferable for forming an antireflection layer. The porous silica may be a silica that is obtained by hydrolyzing an alkoxysilane in the presence of an alkali and is highly intertwined and branched and formed into a polymer, as shown in JP-A-7-133105. The surface-coated porous silica produced by the method described above may be used. Further, the surface of the silica fine particles is improved in dispersibility, and in order to increase the affinity with a compound having a cationic polymerizable functional group in the molecule, for example, as shown in JP-A-7-133105, organosilicon It may be modified with a compound.

  In the curable composition (2), the amount ratio between the compound having a cationically polymerizable functional group in the molecule and the silica fine particles is usually 20 to 90% by weight for the former and 10 for the latter based on the total amount of both. -80% by weight, preferably 30-80% by weight of the former and 20-70% by weight of the latter. Increasing the former and decreasing the latter tend to improve the strength of the antireflection layer. Decreasing the former and increasing the latter decrease the refractive index of the antireflection layer and increase the antireflection effect. Tend to be.

  The curable composition (2) preferably contains silicone oil. Thereby, the formed antireflection layer contains silicone oil, the smoothness or slipperiness of the antireflection layer surface is improved, and the scratch resistance is improved.

  Examples of silicone oils 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, poly Examples include ether-modified silicone oils, and two or more of them can be used as necessary.The addition amount of the silicone oil is usually 0.1 to 20 parts by weight with respect to 100 parts by weight of the total amount of the compound having a cationic polymerizable functional group in the molecule and the silica fine particles. If the amount is too small, the effect of imparting slipperiness is hardly recognized. If the amount is too large, the strength of the antireflection layer decreases, which is not preferable.

  Moreover, additives, such as a stabilizer, antioxidant, and a coloring agent, may be contained in the curable composition (2) like the curable composition (1).

  As the polymerization initiator for curing the curable composition (2), a compound that generates a cation when irradiated with ultraviolet rays is preferably used. Examples of such cationic polymerization initiators include onium salts such as diazonium salts, sulfonium salts and iodonium salts represented by the following formulas.

ArN ₂ ⁺ Z ⁻ ,
^{_{(R) 3 S + Z -}} ,
(R) ₂ I ⁺ Z ^-

In the formula, Ar represents an aryl group, R represents an aryl group or an alkyl group having 1 to 20 carbon atoms, and when R appears multiple times in one molecule, they may be the same or different, and Z ⁻ is Represents a non-basic and non-nucleophilic anion.

In each of the above formulas, the aryl group represented by Ar or R is typically phenyl or naphthyl, and these may be substituted with an appropriate group. Specific examples of the anion represented by Z ⁻ include tetrafluoroborate ion (BF ₄ ⁻ ), tetrakis (pentafluorophenyl) borate ion (B (C ₆ F ₅ ) ₄ ⁻ ), and hexafluoro. Phosphate ion (PF ₆ ⁻ ), hexafluoroarsenate ion (AsF ₆ ⁻ ), hexafluoroantimonate ion (SbF ₆ ⁻ ), hexachloroantimonate ion (SbCl ₆ ⁻ ), hydrogen sulfate ion (HSO ₄ ⁻ ), excess Examples thereof include chlorate ions (ClO ₄ ⁻ ).

  Examples of commercially available products of these cationic polymerization initiators include “Syracure UVI-6990” from Dow Chemical Japan Co., Ltd., “Adekaoptomer SP-150” and “Adekaoptomer SP-170” from Asahi Denka Kogyo Co., Ltd. "RHODORSIL PHOTOINITIATOR 2074" from Rhodia Japan Co., Ltd.

  The cationic polymerization initiator is usually added at a ratio of about 0.1 to 20 parts by weight, preferably about 0.5 to 10 parts by weight, per 100 parts by weight of the compound having a cationic polymerizable functional group in the molecule. If the amount of the initiator is too small, the ultraviolet polymerizability is not sufficiently exerted, and even if the amount is too large, the effect of increasing the amount is not recognized, which is economically disadvantageous, and the optical properties of the antireflection layer. Since there is a possibility of deteriorating characteristics, it is not preferable.

  The antireflection layer is preferably formed by applying and curing the curable composition (2) on the surface of the scratch-resistant layer. For this purpose, the curable composition (2) is formed as a paint. There is a need to. This paint is preferably prepared by dissolving or dispersing a compound having a cationically polymerizable functional group in the molecule, silica fine particles, and, if necessary, other components in a solvent.

  The solvent is used to adjust the concentration and viscosity of the coating material, the layer thickness after curing, and the solvent to be used may be appropriately selected. For example, the coating material of the curable composition (2) described above Similar ones can be used. The amount of the solvent used is appropriately selected according to the material of the substrate, the shape, the coating method, the layer thickness of the target antireflection layer, etc., but usually a compound having a cationically polymerizable functional group in the molecule and The amount is about 20 to 10,000 parts by weight per 100 parts by weight of the total amount of silica fine particles.

  A coating film made of the curable composition (2) is formed by applying such a coating to the surface of the scratch-resistant layer. The coating is applied in the same manner as the coating of the curable composition (1) described above, for example, micro gravure coating method, roll coating method, dipping coating method, flow coating method, spin coating method, die coating method, cast transfer. The method is performed by a method such as a spray coating method.

Next, the antireflection layer can be formed by irradiating ultraviolet rays to cure the coating film. Irradiation with ultraviolet rays can be performed in the same manner as in the formation of the scratch-resistant layer described above, the irradiation time is usually about 0.1 to 60 seconds, and the irradiation temperature is usually about 10 to 40 ° C. . Moreover, the irradiation energy of ultraviolet rays is about 50-3000 mJ / cm < ² > normally, Preferably it is about 100-700 mJ / cm < ² >. When the irradiation amount of ultraviolet rays is too small, curing is insufficient and the strength of the antireflection layer is lowered. On the other hand, if the amount of UV irradiation is too large, the antireflection layer, the scratch-resistant layer and the substrate are deteriorated, which may cause a decrease in optical properties and mechanical properties.

  When the paint contains a solvent, as in the formation of the scratch-resistant layer described above, the ultraviolet ray may be irradiated while the film contains the solvent, or after the solvent is volatilized. May be. When the solvent is volatilized, it may be left at room temperature or may be dried by heating at about 30 to 100 ° C. The drying time is appropriately selected according to the material, shape, coating method, layer thickness of the desired antireflection layer, and the like. After forming the antireflection layer by ultraviolet irradiation, a heat treatment may be further performed to make the antireflection layer stronger. The heating temperature and time are appropriately selected, but are usually about 50 to 120 ° C. and about 30 minutes to 24 hours.

  In the laminate of the present invention, the adhesion between the scratch-resistant layer and the antireflection layer is excellent because the scratch-resistant layer was formed by curing the curable composition (1) by radical polymerization. At that time, the cationic polymerizable functional group of the compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule remains in the scratch-resistant layer in an unreacted state, and the subsequent curable composition (2) At the stage of curing by cationic polymerization to form an antireflection layer, the cation polymerizable functional group of the compound having a cationic polymerizable functional group in the molecule in the antireflection layer and the unreacted remaining in the scratch resistant layer This is thought to be due to the reaction between the cationically polymerizable functional groups of the two and the formation of bonds between the two layers.

  Moreover, in the above description, although hardening of curable composition (1) and hardening of curable composition (2) were described in steps, curable composition (1) and curable composition ( And 2) are incompatible with each other, after a coating film of the curable composition (1) is formed on the surface of the substrate, the coating film of the curable composition (2) is left uncured thereon. Then, the curable compositions (1) and (2) can be simultaneously cured by irradiating with ultraviolet rays.

  The layer thickness of the formed antireflection layer is usually 0.01 to 1 μm. Even if it is too small or too large, it is difficult to obtain a function as an antireflection film.

  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. Moreover, the obtained laminated body was evaluated with the following method.

(1) Reflection spectrum Using an ultraviolet-visible spectrophotometer [“UV-3100” manufactured by Shimadzu Corporation], an absolute specular reflection spectrum at an incident angle of 5 ° was measured, and the lowest reflectance at 400 to 800 nm was obtained. Read. In this measurement method, reflection from both the front and back surfaces of the laminate is detected, but a reflection spectrum as performance closer to practical use can be obtained.

(2) Gauze abrasion hardness eraser abrasion tester eraser tip of [KK present Hikariseisakusho] covered with gauze, back and forth of the surface of the laminated body while applying a pressure of 49N / cm ^2, scratches on the surface by visual observation It was evaluated by the number of round-trips until it was confirmed.

(3) Surface resistance According to JIS K6911, the surface resistance of the surface of the laminated body was measured.

(4) Adhesiveness On the laminate, a 100 mm grid with a cutter knife is formed at a depth reaching the base material, and cellophane tape (manufactured by Nichiban Co., Ltd., 24 mm width) is pasted on the grid. Then it was peeled off in the vertical direction. This operation was repeated three times, and the number of peeled grids was determined.

Moreover, the following evaluation was performed in the stage which formed only the abrasion-resistant layer.
(5) Steel Wool Hardness Using # 0000 steel wool, the surface of the scratch-resistant layer was reciprocated 10 times with a load of 500 g / cm ² , and the surface condition was visually observed.

(6) Layer thickness The layer thickness of the scratch-resistant layer was measured with a microscopic film thickness meter MS-2000 (manufactured by Otsuka Electronics Co., Ltd.).

Example 1
(Formation of scratch-resistant layer)
15.3 parts of dipentaerythritol hexaacrylate [Shin Nakamura Chemical Co., Ltd. “NK Ester A-9530”], 2,2-bis [4- (acryloyloxydiethoxy) phenyl] propane [Shin Nakamura Chemical Co., Ltd. 3.8 parts of “NK Ester A-BPE-4” from Co., Ltd., 3.4 parts of 3-ethyl-3-methacryloyloxymethyloxetane [“ETERNACOLL OXMA” from Ube Industries, Ltd.], 2- 47.2 parts of methyl-1-propanol, 20.3 parts of 1-methoxy-2-propanol, 1-hydroxycyclohexyl phenyl ketone [“IRUGACURE 184” manufactured by Ciba Specialty Chemicals Co., Ltd .; polymerization initiator] 1.2 parts and an antimony pentoxide fine particle dispersion having an average particle size of 20 to 30 nm [Catalyst Chemical Industries, Ltd. "ELCOM PC-14"; 10 parts concentration of 20%], and mixed to prepare a scratch resistant coating.

A 2 mm-thick methyl methacrylate-styrene copolymer resin plate (“Acryase MS” from Nihon Acryase Co., Ltd.) is dipped in this paint, and dip-coated at a pulling speed of 60 cm / min. After drying, it was dried at 60 ° C. for 10 minutes. After drying, a resin having an abrasion resistant layer having a thickness of about 4 μm on both sides by irradiating ultraviolet rays with a high-pressure mercury lamp (“UVC-3533” manufactured by USHIO INC.) With an energy of about 500 mJ / cm ^2. I got a plate. The evaluation results are shown in Table 1.

(Formation of antireflection layer)
5 parts of a sol in which 20% to 70 nm porous silica fine particles having a surface coated with a hydrolyzate of ethyl silicate and dispersed in 20% of isopropyl alcohol are mixed with 3-ethyl-3-[{3- (triethoxy Silyl) propoxy} methyl] oxetane [compound of formula (III) wherein R ¹ = ethyl, R ³ = ethoxy, n = 3, p = 0] oxetanylsilsesquioxane [Toagosei Co., Ltd.], 0.7 parts of 3,4-epoxycyclohexylmethyl 3 ', 4'-epoxycyclohexanecarboxylate, p-cumyl-p-tolyliodonium tetrakis (pentafluorophenyl) borate [Rhodia 0.1 part of “RHODORSIL PHOTOINITIATOR 2074”; polymerization initiator] from Japan, 84 parts of B pills alcohol, and 10 parts of 2-butoxyethanol, and mixed to prepare an anti-reflective coating.

The resin plate having the scratch-resistant layer obtained above was immersed in this paint, dip-coated at a lifting speed of 24 cm / min, dried at room temperature for 1 minute or more, and then dried at 60 ° C. for 10 minutes. . After drying, a high pressure mercury lamp (“UVC-3533” from USHIO INC.) Is irradiated with ultraviolet rays at an energy of about 500 mJ / cm ² to obtain a laminate having an antireflection layer on the scratch resistant layer. It was. The evaluation results are shown in Table 1.

Example 2
In preparing the scratch-resistant paint, 12.6 parts of dipentaerythritol hexaacrylate, 3.2 parts of 2,2-bis [4- (acryloyloxydiethoxy) phenyl] propane, and 3-ethyl The same operation as in Example 1 was performed, except that the amount of -3-methacryloyloxymethyloxetane was changed to 6.7 parts. The evaluation results are shown in Table 1.

Example 3
The same operation as in Example 1 was performed except that 0.2 parts of epoxy-modified silicone oil [“X-22-163A” from Shin-Etsu Chemical Co., Ltd.] was further added during the preparation of the antireflection coating. . The evaluation results are shown in Table 1.

Example 4
In preparing the scratch-resistant paint, the same operation as in Example 1 was performed except that glycidyl methacrylate was used instead of 3-ethyl-3-methacryloyloxymethyloxetane. The evaluation results are shown in Table 1.

Comparative Example 1
In preparing the scratch-resistant paint, the amount of dipentaerythritol hexaacrylate was changed to 18 parts and the amount of 2,2-bis [4- (acryloyloxydiethoxy) phenyl] propane was changed to 4.5 parts. The same operation as in Example 1 was carried out except that -ethyl-3-methacryloyloxymethyloxetane was not used. The evaluation results are shown in Table 1. Since a compound having a cationically polymerizable functional group and a radically polymerizable functional group in the molecule was not used, the adhesion between the scratch-resistant layer and the antireflection layer was low, and peeling between the two layers was 34 per 100 grids. I was seen. Further, the hardness of the scratch-resistant layer is good, but the hardness of the antireflection layer is low.

Comparative Example 2
In preparing the scratch-resistant paint, the amount of dipentaerythritol hexaacrylate is 7.2 parts, the amount of 2,2-bis [4- (acryloyloxydiethoxy) phenyl] propane is 1.8 parts, and 3-ethyl The same operation as in Example 1 was performed, except that the amount of -3-methacryloyloxymethyloxetane was changed to 13.5 parts. The evaluation results are shown in Table 1. The amount of the compound having a cation polymerizable functional group and a radical polymerizable functional group in the molecule is more than the specified value, so the adhesion between the scratch resistant layer and the antireflection layer is good, but the hardness of the scratch resistant layer. And the hardness of the antireflection layer thereon is also low.

The laminate of the present invention can be used for various applications that require antireflection properties, and is particularly suitably used as a front plate for displays such as projection televisions.

Claims (4)

50 to 99 parts by weight of a compound having at least two radical polymerizable functional groups in the molecule on the surface of the transparent substrate, and 1 to 50 weights of the compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule And 0.1 parts by weight with respect to a total of 100 parts by weight of a compound having at least two radical polymerizable functional groups in the molecule and a compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule. A coating containing 1 to 20 parts by weight of a radical polymerization initiator is applied and cured to form a scratch-resistant layer, and then a compound 20 having a cationically polymerizable functional group in the molecule on the scratch-resistant layer. Cation polymerization of 0.1 to 20 parts by weight with respect to 100 parts by weight of a compound containing ˜90 parts by weight and 10 to 80 parts by weight of silica fine particles and having a cationic polymerizable functional group in the molecule. A method for producing a laminate for forming an antireflection layer coating applied to cure the containing initiator,
The laminate is formed by forming a scratch-resistant layer and an antireflection layer in this order from the substrate surface side on the surface of the transparent substrate, and the scratch-resistant layer has at least two radical polymerizable functional groups in the molecule. A composition containing 50 to 99 parts by weight of a compound having a group and 1 to 50 parts by weight of a compound having a cationic polymerizable functional group and a radical polymerizable functional group in the molecule is cured, and the antireflection layer is A composition comprising a compound having a cationic polymerizable functional group in the molecule and silica fine particles is cured, and further, the cationic polymerizable functional group in the scratch-resistant layer and the cationic polymerizable property in the antireflection layer A production method in which a bond is formed with a functional group. The production method according to claim 1, wherein the silica fine particles are porous silica fine particles. The production method according to claim 1 or 2, wherein the composition for forming the scratch-resistant layer further contains conductive fine particles. The compound having a cationically polymerizable functional group in the molecule contained in the composition for forming the antireflection layer is an oxetane compound having a silyl group in the molecule or a hydrolysis condensate thereof. The manufacturing method of crab.