Water-based coating agents and decorative sheets for building materials

Abstract

This invention provides a water-based coating agent for building materials that exhibits excellent adhesion to plastic substrates, high durability, high scratch resistance, high sliding resistance, high solvent resistance, and high alkali resistance. [Solution] An aqueous coating agent for building materials containing a (meth)acrylic emulsion, a curing agent and a silane coupling agent, wherein the silane coupling agent is contained in an amount of 5 to 30% by mass relative to the non-volatile components and inorganic fine particles are contained in an amount of 0.5 to 10.0% by mass relative to the non-volatile components, and a decorative sheet using the same. The aqueous coating agent for building materials preferably contains wax in an amount of 0.1 to 20.0% by mass relative to the non-volatile components.

Description

Technical Field

[0001] The present invention relates to an aqueous coating agent for building materials and a decorative sheet using the same.

Background Art

[0002] Generally, as a material that can give an appearance (design) close to natural materials by laminating on the surface of plywood or the like for furniture, interior decoration of houses, interior materials of vehicles, etc., a "decorative sheet" is adopted. For such a decorative sheet, high durability, design, texture close to natural materials, and functionality are required. Therefore, in addition to a printing layer for imparting design on a plastic substrate, a coating layer imparting high durability, texture, and functionality is provided.

[0003] As a coating agent used for such a coating layer for a decorative sheet, an aqueous coating agent is known. For example, an aqueous coating agent containing an aqueous acrylic resin emulsion having a glass transition temperature of 80°C or higher and an acid value of 50 mgKOH / g or higher and a carbodiimide curing agent (see Patent Document 1), and an aqueous coating agent containing a polycarbonate-based urethane resin and a carbodiimide curing agent (see Patent Document 2) are known. In these coating agents, for the purpose of high durability, design, and texture close to natural materials, a carbodiimide curing agent is used to increase the crosslinking density to impart scratch resistance and stain resistance (see paragraph 0030 of Patent Document 2), and a filler such as silica is added to adjust gloss and impart scratch resistance (see paragraph 0035 of Patent Document 2). However, even with these coating agents, problems such as poor adhesion to the plastic substrate sometimes occur, the surface is scratched when the surface of the decorative sheet is rubbed with steel wool or the like, and when transporting the plywood after laminating the decorative sheets, since the plywoods are laminated, the surface portion of the decorative sheet on the outermost surface is rubbed and damaged (sliding resistance) have not been completely solved.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-144456 [Patent Document 2] Japanese Patent Publication No. 2023-122995 [Overview of the project] [Problems that the invention aims to solve]

[0005] The object of the present invention is to provide an aqueous coating agent for building materials that has good adhesion to plastic substrates and excellent durability, scratch resistance, sliding resistance, solvent resistance, and alkali resistance.

[0006] As a result of diligent research, the inventors have found that an aqueous coating agent for building materials containing a (meth)acrylic emulsion, a curing agent, and a silane coupling agent, wherein the silane coupling agent is contained in a specific amount relative to the non-volatile components, and inorganic fine particles are contained in a specific amount relative to the non-volatile components, solves the above problem.

[0007] Furthermore, we discovered that by adding specific amounts of wax and a matting agent to the above composition, an aqueous coating agent for building materials with even better sliding properties can be obtained.

[0008] In other words, the present invention provides an aqueous coating agent for building materials that contains a (meth)acrylic emulsion, a curing agent, and a silane coupling agent, wherein the silane coupling agent is contained in an amount of 5 to 30% by mass relative to the non-volatile components, and inorganic fine particles are contained in an amount of 0.5 to 10.0% by mass relative to the non-volatile components.

[0009] The present invention also provides the above-described aqueous coating agent for building materials, which contains wax in an amount of 0.1 to 20.0% by mass relative to the non-volatile components.

[0010] The present invention also provides the above-described aqueous coating agent for building materials, which contains a matting agent in an amount of 1 to 30% by mass relative to the non-volatile components.

[0011] The present invention also provides an aqueous coating agent for building materials as described above, which contains inorganic fine particles and wax, wherein the wax content is 1 / 3 or more of the inorganic fine particle content, and the average particle diameter of the wax is greater than 1 / 2 of the average particle diameter of the inorganic fine particles.

[0012] Furthermore, the present invention provides the above-described aqueous coating agent for building materials containing a polar group-containing olefin resin.

[0013] The present invention also provides the above-described aqueous coating agent for building materials, wherein the curing agent is an epoxy-based curing agent or an aziridine-based curing agent.

[0014] The present invention also provides a decorative sheet having a coating layer of an aqueous coating agent on a plastic substrate, wherein the aqueous coating agent is the aqueous coating agent for building materials described above.

[0015] Furthermore, the present invention relates to a decorative sheet having a coating layer 1 of an aqueous coating agent 1 and a coating layer 2 of an aqueous coating agent 2 on a plastic substrate, The present invention provides a decorative sheet in which the aqueous coating agent 1 and / or the aqueous coating agent 2 are the aqueous coating agents for building materials described above. [Effects of the Invention]

[0016] The present invention provides a water-based coating agent for building materials that is less prone to adhesion problems and exhibits excellent durability, scratch resistance, sliding resistance, solvent resistance, and alkali resistance, as well as a decorative sheet using the same. [Modes for carrying out the invention]

[0017] ((meth)acrylic emulsion) The (meth)acrylic emulsion used in this invention is not particularly limited, and any known and readily available (meth)acrylic emulsion can be used.

[0018] ((meth)acrylic resin) There are no particular limitations on the (meth)acrylic resin contained in the aqueous (meth)acrylic emulsion, and examples include homopolymers or copolymers of (meth)acrylate, and copolymers obtained by copolymerizing (meth)acrylate with vinyl monomers that can copolymerize with (meth)acrylate. Furthermore, it is preferable that the copolymer has an acid value in order to impart water dispersibility, water solubility, and reactivity with epoxy curing agents and aziridine curing agents. In this invention, "(meth)acrylate" refers to either acrylate or methacrylate, or both, and "(meth)acrylic" refers to either acrylic or methacrylic, or both.

[0019] Examples of (meth)acrylates and vinyl monomers copolymerizable with (meth)acrylates include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-pentafluoropropyl (meth)acrylate, perfluorocyclohexyl (meth)acrylate, glycidyl (meth)acrylate, allyl glycidyl ether, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, (meth)acrylamide, N-monoalkyl (meth)acrylamide, N,N-dialkyl (meth)acrylamide, N-methylol (meth)acrylamide, N-isopropoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, N-isobutoxymethyl (meth)acrylamide, 2-aziridinyl ethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, acrolein, diacetone (meth)acrylamide, acetoacetoxyethyl (meth)acrylate, etc. The (meth)acrylate may be used alone or in combination of two or more.

[0020] Examples of vinyl monomers include vinyl acetate, vinyl propionate, vinyl versatate, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, (meth)acrylonitrile, styrene, α-methylstyrene, divinylstyrene, isoprene, chloroprene, butadiene, ethylene, tetrafluoroethylene, vinylidene fluoride, N-vinylpyrrolidone and other vinyl monomers. The polymerizable unsaturated group-containing compound may be a single species or a combination of two or more species.

[0021] Also, for the purpose of introducing one or more acidic groups selected from the group consisting of a carboxyl group and a carboxylate group in which the carboxyl group is neutralized by a basic compound, (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, β-(meth)acryloyloxyethyl hydrogen succinate, β-(meth)acryloyloxyethyl hydrogen phthalate and other (meth)acrylic monomers having a carboxyl group are copolymerized to obtain a copolymer having an acid value. When introducing an acidic group, as will be described in detail later, it is preferable to appropriately adjust the monomer amount so that the acid value falls within a desired range.

[0022] Also, the (meth)acrylic resin may be reacted with a self-crosslinking component. That is, the (meth)acrylic resin may be self-crosslinking. Examples of the self-crosslinking component include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds and the like.

[0023] (Meth)acrylic resins can be produced, for example, by polymerizing various monomers in the presence of a polymerization initiator at a temperature range of 50°C to 180°C, more preferably 80°C to 150°C. Examples of polymerization methods include bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. Furthermore, when (meth)acrylic resins are copolymers, they may be random copolymers, block copolymers, graft copolymers, etc., from the viewpoint of their polymerization mode. When obtained by the bulk polymerization or solution polymerization methods described above, the (meth)acrylic resin to which acidic groups have been introduced can be neutralized with a neutralizing agent such as an alkali after polymerization, and the solvent can be replaced with an aqueous medium to obtain an aqueous emulsion.

[0024] The (meth)acrylic resin may also preferably be an emulsion that forms a core-shell structure. The above-mentioned core-shell emulsion refers to a state in which a first polymer is dispersed in an aqueous medium by a second polymer, and usually the second polymer is located on the outermost surface of the resin particles to form the shell portion, and part or all of the first polymer forms the core portion.

[0025] The above aqueous (meth)acrylic emulsion is characterized by having a glass transition temperature (Tg) of 0 to 110°C. This range is preferable as it allows the present invention to exert its maximum effect. In particular, a glass transition temperature (Tg) of 20°C or higher is more preferable, 30°C or higher is even more preferable, 40°C or higher is even more preferable, and 100°C or lower is even more preferable.

[0026] In this invention, the glass transition temperature (Tg) refers to the so-called calculated glass transition temperature, which is the value calculated by the method described below. (Formula 1) 1 / Tg(K)=(W1 / T1)+(W2 / T2)+...(Wn / Tn) (Equation 2) Tg(°C) = Tg(K) - 273 In Equation 1, W1, W2, ...Wn represent the mass percentage of each monomer relative to the total mass of monomers used in the production of the polymer, and T1, T2, ...Tn represent the glass transition temperature (K) of the homopolymer of each monomer. The values ​​of T1, T2, ...Tn are those listed in the Polymer Handbook (Fourth Edition, edited by J. Brandrup, EH Immergut, and EA Grulke). For monomers whose homopolymer glass transition temperatures are not listed in the Polymer Handbook, the glass transition temperatures were measured using a differential scanning calorimeter "DSCQ-100" (manufactured by TA Instrument Co., Ltd.) in accordance with JIS K7121. Specifically, the polymer, from which the solvent had been completely removed by vacuum suction, was subjected to a heating rate of 20°C / min, and the change in heat quantity was measured in the range of -100°C to +200°C. The point where a line equidistant in the vertical direction from the extended line of each baseline intersected the curve of the stepwise transition portion of the glass transition was defined as the glass transition temperature.

[0027] The acid value (also referred to as "AV") of the (meth)acrylic resin used in the above (meth)acrylic emulsion is preferably 10 mg KOH / g or higher, and most preferably 20 mg KOH / g or higher. An acid value of 10 mg KOH / g or higher is preferable because it allows the resin to crosslink strongly, thereby maximizing the effects of the present invention. In this invention, the acid value refers to the number of milligrams of potassium hydroxide required to neutralize the acidic components contained in 1 gram of resin.

[0028] The glass transition temperature (also referred to as "Tg") of the (meth)acrylic resin used in the above (meth)acrylic emulsion is preferably 0°C to 110°C, and most preferably 10°C to 100°C. This range is preferable as it allows the effects of the present invention to be maximized.

[0029] The minimum film-forming temperature (also referred to as "MFT") of the above (meth)acrylic emulsion is preferably -20°C to 80°C, and most preferably 70°C or lower. This range is preferable as it allows the effects of the present invention to be maximized.

[0030] In the present invention, it is preferable that the (meth)acrylic resin (A) is an acrylic resin (i.e., a resin obtained by polymerizing substantially only (meth)acrylic acid ester monomers) or a styrene-acrylic resin (i.e., a resin obtained by copolymerizing styrene monomer and (meth)acrylic acid ester monomer).

[0031] (Water-based solvent) Examples of aqueous solvents used in the present invention include water and water-soluble organic solvents. As water, pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, or distilled water, or ultrapure water can be used. Furthermore, it is preferable to use water that has been sterilized by ultraviolet irradiation or hydrogen peroxide addition. Examples of aqueous organic solvents include water or aqueous solvents, such as glycols including ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol; diols including butanediol, pentanediol, and hexanediol; glycol esters including propylene glycol laurate; diethylene glycol ethers including diethylene glycol monoethyl, diethylene glycol monobutyl, diethylene glycol monohexyl, and carbitol; glycol ethers including cellosolve containing propylene glycol ether, dipropylene glycol ether, and triethylene glycol ether; alcohols including methanol, ethanol, isopropyl alcohol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, butyl alcohol, and pentyl alcohol; and various other solvents known as aqueous organic solvents, such as sulfolanes, esters, ketones, lactones including γ-butyrolactone, lactams including N-(2-hydroxyethyl)pyrrolidone, glycerin, and its polyalkylene oxide adducts. These aqueous organic solvents can be used individually or in combination of two or more. Of these, water is the most preferable.

[0032] Examples of commercially available (meth)acrylic emulsions include the Barnock series from DIC Corporation, the Hyros series from Seikoh PMC Corporation, Joncryl from BASF Japan Ltd., and NeoCryl from Covestro Japan Inc.

[0033] (Hardening agent) The curing agent used in the present invention comprises at least one of isocyanate-based curing agents, epoxy-based curing agents, metal chelate-based curing agents, and aziridine-based curing agents or carbodiimide-based curing agents. It is preferable to use one or more of these as the curing agent. Among these, epoxy-based curing agents or aziridine-based curing agents are preferred.

[0034] (Epoxy-based hardening agent) The epoxy curing agent used in this invention is not particularly limited, and any known and readily available epoxy curing agent can be used. Specifically, examples include phenol (ethylene glycol modified) glycidyl ether, lauryl alcohol (ethylene glycol modified) glycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, epoxy cresol novolac, and the like. Among these, polyglycerol polyglycidyl ether and sorbitol polyglycidyl ether are preferred, with sorbitol polyglycidyl ether being the most preferred.

[0035] The epoxy equivalent of the epoxy curing agent used in this invention is preferably 120 g / eq. or more, and more preferably 140 g / eq. or more. The epoxy equivalent is measured in accordance with JIS K 7236. The epoxy curing agent is preferably contained in an amount of 5 to 30% by mass relative to the non-volatile components of the aqueous coating agent of the present invention, and more preferably in an amount of 10 to 20% by mass.

[0036] Examples of aziridine-based curing agents used in the present invention include N,N'-(4,4'-methylenediphenyl)bis(aziridine-1-carboxamide), 1,1'-isophthaloylbis(2-methylaziridine), tris(1-aziridinyl)phosphine oxide, 1,1'-hexamethylenebis(iminocarbonyl)bisaziridine, trimethylolpropane-tris(2-aziridinylpropionate), 2,4,6-tris(1-aziridinyl)-1,3,5-triazine, and 2,2-bis(hydroxymethyl)butanol tris[3-(1-aziridinyl)propionate].

[0037] The curing agent described above is preferably used in an amount of 5 to 30% by mass relative to the non-volatile components of the aqueous coating agent for building materials of the present invention, and more preferably in an amount of 10 to 20% by mass.

[0038] (Silane coupling agent) The silane coupling agent used in the present invention is not particularly limited, and any known and readily available silane coupling agent can be used. Specifically, examples include epoxysilanes, aminosilanes, chlorosilanes, vinylsilanes, and isocyanatosilanes. Examples of epoxysilanes include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Examples of aminosilanes include N-2-(aminoethyl)-3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane. Examples of chlorosilanes include vinyltrichlorosilane. Examples of vinylsilanes include vinyltriethoxysilane. Examples of isocyanatosilanes include 3-isocyanatopropyltrimethoxysilane. These can be used individually or in combination of two or more types. Among these, 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 8-glycidoxyoctyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane are preferred, with 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane being the most preferred.

[0039] The silane coupling agent is preferably present in an amount of 5 to 30% by mass relative to the non-volatile components of the aqueous coating agent of the present invention, and more preferably in an amount of 10 to 20% by mass. By including 5% or more of the silane coupling agent, improved adhesion to the substrate and improved alkali resistance can be expected. By keeping it below 30%, the carboxyl groups of the resin remain, ensuring reaction sites with the epoxy curing agent, which can lead to an improvement in the crosslinking density of the coating film.

[0040] In this invention, the ratio of the curing agent to the silane coupling agent is 4:1 to 1:2. Within this range, the effects of the present invention can be maximized. Among these ratios, 3:1 to 1:2 is preferred, and 2:1 to 1:2 is most preferred. In particular, it is preferable to use an epoxy curing agent or an aziridine curing agent.

[0041] (Polar group-containing olefin resin) In the present invention, in addition to containing the above-mentioned (meth)acrylic emulsion, curing agent, and silane coupling agent, the adhesion to plastic substrates can be particularly enhanced by using a polar group-containing olefin resin in combination. Since the aqueous coating agent used in combination with the polar group-containing olefin resin is particularly useful for the whitening phenomenon caused by the lifting of the coating layer on the surface of decorative sheets due to weather deterioration, it is also useful when used as a primer layer (sealant layer) that comes into direct contact with the plastic substrate.

[0042] The polar groups in polar group-containing olefin resins include, specifically, halogen groups such as chlorine groups, bromine groups, or iodine groups, as well as hydroxyl groups and carboxyl groups. Among these, chlorine groups and carboxyl groups are preferred.

[0043] (Olefin resin containing chlorine groups) The olefin resin (also called chlorinated polyolefin) containing a chlorine group as a polar group used in the present invention is not particularly limited, and known chlorinated polyolefins can be used. Specifically, examples of chlorinated polyolefins include chlorinated polypropylene resin and chlorinated polyethylene resin. Examples of the above olefins include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene, butadiene, dicyclopentadiene, and 5-ethylidene-2-norbornene. Furthermore, the chlorinated polyolefin may be a modified product. The modified product is not particularly limited. For example, a modified product of chlorinated polyolefin is a chlorinated polyolefin graft polymerized with a polymerizable acrylic compound (such as acrylic acid, methacrylic acid, or alkyl esters thereof) or an unsaturated polycarboxylic acid (such as maleic acid, maleic anhydride, itaconic acid, or itaconic anhydride), or a polyolefin graft polymerized with the above unsaturated polycarboxylic acid and then chlorinated.

[0044] The chlorine content in chlorinated polyolefins is not particularly limited. For example, the chlorine content is preferably 1% by mass or more, and more preferably 10% by mass or more, relative to the total resin. Furthermore, the chlorine content is preferably 40% by mass or less, and more preferably 30% by mass or less, relative to the total resin.

[0045] When chlorinated polyolefins are used in combination, the content of chlorinated polyolefins is preferably 5 to 30% by mass relative to the non-volatile components of the aqueous coating agent of the present invention, and more preferably 10 to 20% by mass.

[0046] (Carboxyl group-containing olefin resin) The olefin-based resin (also referred to as olefin-α,β unsaturated carboxylic acid copolymer) used in the present invention, which contains a carboxyl group as a polar group, includes copolymers of olefins with at least one monomer selected from the group consisting of α,β-unsaturated carboxylic acids, metal salts of α,β-unsaturated carboxylic acids, and α,β-unsaturated carboxylic acid esters. Specifically, it is a copolymer of α,β-unsaturated carboxylic acids, metal salts of α,β-unsaturated carboxylic acids, or α,β-unsaturated carboxylic acid esters with olefins, and includes olefin-α,β unsaturated carboxylic acid copolymers, ethylene-acrylic acid ester copolymers, ethylene-methacrylic acid copolymers, ethylene-methacrylic acid ester copolymers, ethylene-acrylic acid-maleic anhydride copolymers, ethylene-acrylic acid ester-maleic anhydride copolymers, ethylene-methacrylic acid-maleic anhydride copolymers, ethylene-methacrylic acid ester-maleic anhydride copolymers, and metal salts thereof. These copolymers may be used individually or as mixtures of two or more. Among these, olefin-α,β-unsaturated carboxylic acid copolymers are preferred. Examples of olefin-α,β-unsaturated carboxylic acid copolymers include random copolymers or block copolymers of ethylene- and α,β-unsaturated carboxylic acids. Examples of the olefins mentioned above include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene, butadiene, dicyclopentadiene, and 5-ethylidene-2-norbornene. Ethylene is preferred among these. Examples of the α,β-unsaturated carboxylic acids mentioned above include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid. Among these, acrylic acid and methacrylic acid are preferred. These α,β-unsaturated carboxylic acids may be used individually or in combination of two or more.

[0047] As the α,β-unsaturated carboxylic acid ester mentioned above, any known alkyl esters, hydroxyalkyl esters, alkoxyalkyl esters, etc. of acrylic acid or methacrylic acid can be used without particular limitation. For example, specific examples include acrylic acid esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, n-octyl acrylate, 2-hydroxyethyl acrylate, and 2-methoxyethyl acrylate; and methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-lauryl methacrylate, 2-hydroxyethyl methacrylate, and 2-ethoxyethyl methacrylate. These can be used individually or in combination of two or more.

[0048] (Aqueous dispersion of polar group-containing olefin resin) The above polar group-containing olefin resin is used as an aqueous dispersion obtained by dispersing it in an aqueous solvent. The method of dispersion in the aqueous solvent is not particularly limited and any known method may be used. For example, methods include emulsifying with a surfactant and dispersing in an aqueous solvent, or (especially when the polar group is a carboxyl group) neutralizing the polar group with a basic compound and then dispersing in an aqueous solvent.

[0049] As the surfactant used in the emulsification process described above, various known anionic, cationic, and nonionic surfactants, or various water-soluble polymers can be used in appropriate combination.

[0050] Examples of basic compounds used to neutralize the carboxyl groups in carboxyl group-containing olefin resins include organic amines such as ammonia, methylamine, ethylamine, diethylamine, dimethylethanolamine, diethanolamine, and triethanolamine, and alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide. These basic compounds may be used alone or in combination of two or more. The degree of neutralization by the basic compound should be, for example, 30 to 100 mol% of the carboxyl groups, and more preferably 40 to 90 mol%.

[0051] As for the above dispersion method, known methods can be used, such as dispersion devices using media, including paint shakers, ball mills, attritors, basket mills, sand mills, sand grinders, dyno mills, disper mats, SC mills, spike mills, agitator mills, etc., and dispersion can be performed using non-media devices such as ultrasonic homogenizers, high-pressure homogenizers, nanomizers, dissolvers, dispersers, and high-speed impeller dispersers.

[0052] (Inorganic fine particles) The aqueous coating agent of the present invention contains inorganic fine particles (sometimes referred to as scratch-resistant fillers). The inorganic fine particles are not particularly limited, but inorganic fine particles with an oil absorption capacity of 0 mL / 100 g to 100 mL / 100 g and an average particle size of 1 to 20 μm are often used. Furthermore, by using inorganic fine particles in combination with a matting agent, it can be used as a highly scratch-resistant matte coating agent.

[0053] Examples of the inorganic fine particles mentioned above include silton, titanium dioxide, alumina particles (aluminum oxide, aluminosilicate), calcium carbonate, barium sulfate, glass beads, silicone beads, and silicone powder. These inorganic fine particles can be used individually or in combination. For a higher scratch resistance, it is preferable to use materials such as silton, glass beads, silicone beads, or silicone powder.

[0054] The oil absorption capacity of the above inorganic fine particles is preferably in the range of 0 mL / 100 g to 150 mL / 100 g, and more preferably in the range of 0 mL / 100 g to 100 mL / 100 g. Within this range, a coating film with high scratch resistance can be obtained.

[0055] The average particle size of the above inorganic fine particles is preferably in the range of 1 to 20 μm, and more preferably in the range of 1 to 15 μm. The average particle size is the value measured using a Nanotrac UPA EX-150 nanoparticle size distribution analyzer manufactured by Nikkiso Co., Ltd. The average particle size of the inorganic fine particles mentioned above depends on the desired coating film thickness, but if the average particle size is approximately equal to or greater than the film thickness, a coating film with higher scratch resistance can be obtained.

[0056] The content of the inorganic fine particles is preferably 0.5 to 10.0% by mass, and more preferably 1.0 to 5.0% by mass, relative to the nonvolatile components of the aqueous coating agent of the present invention. If the content is less than 0.5% by mass, it may be difficult to obtain sufficient scratch resistance, and if it exceeds 10.0% by mass, it may settle in the aqueous coating agent and form a hard cake, which may worsen workability. In particular, when using inorganic fine particles with low oil absorption, the possibility of settling increases, so when using inorganic fine particles with low oil absorption (specifically, those with an oil absorption of 100 mL / 100 g or less), it is preferable that the content does not exceed 10.0% by mass.

[0057] (wax) The aqueous coating agent of the present invention may contain wax. The inclusion of wax improves sliding properties, and in particular, when transporting plywood with a decorative sheet attached, it is possible to prevent the outermost surface of the decorative sheet from being rubbed and scratched. Examples of waxes include olefin-based waxes. Specifically, these include polyethylene wax, polypropylene wax, Fischer-Tropsch wax, paraffin wax, and microstarin wax. One type of wax may be used, or two or more types may be mixed together.

[0058] The amount of the above-mentioned wax should be in the range of 0.1 to 20.0% by mass relative to the non-volatile components of the aqueous coating agent, and more preferably in the range of 0.1 to 10.0% by mass. If the amount is less than 0.1% by mass, the surface lubricity of the coating film will be insufficient, and surface sliding properties will tend to deteriorate. If it exceeds 20.0% by mass, the coating suitability will tend to deteriorate.

[0059] The average particle size of the above wax is preferably in the range of 1 to 20 μm, and more preferably in the range of 1 to 10 μm. The average particle size is the value measured using a Nanotrac UPA EX-150 nanoparticle size distribution analyzer manufactured by Nikkiso Co., Ltd.

[0060] The inorganic fine particles and the wax described above are preferably used in combination to achieve particularly good scratch resistance and surface sliding properties. When used in combination, it is preferable that the amount of wax is 1 / 3 or more of the amount of inorganic fine particles. For example, if the inorganic fine particles are present in an amount of 3% by mass relative to the nonvolatile components of the aqueous coating agent, it is preferable that the amount of wax be 1 / 3 or more of 3% by mass. Furthermore, it is preferable that the amount of wax be 2 / 3 by mass or more relative to the amount of inorganic fine particles.

[0061] Furthermore, when used in combination, the average particle size of the wax is preferably at least half the average particle size of the inorganic fine particles. For example, if the average particle size of the inorganic fine particles is 5 μm, the average particle size of the wax is preferably at least half of 5 μm. Moreover, it is preferable to use a wax with an average particle size larger than that of the inorganic fine particles.

[0062] When the above inorganic fine particles and the above wax are used in combination, the combination can be arbitrary, but a more preferred combination is one inorganic fine particle selected from the group consisting of glass beads, silton, alumina, and silicone powder. Furthermore, polyolefin wax is preferred as the above wax.

[0063] (Matte agent) When using the aqueous coating agent of the present invention as a matte coating agent, it is preferable to add a matting agent. The matting agent is not particularly limited, but fine particles with an oil absorption capacity of 200 mL / 100 g to 400 mL / 100 g and an average particle size of 0.3 to 20 μm are often used. These fine particles can be used individually or in combination, without any particular limitation, whether organic or inorganic, as long as they are known. Specifically, inorganic particles such as silica, titanium dioxide, alumina particles (aluminum oxide), calcium carbonate, barium sulfate, and glass, or organic particles such as acrylic resin, urethane resin, polycarbonate resin, silicone resin, and polystyrene resin, as well as silicone beads, can be used. For a higher matting effect, silica and aluminosilicate beads are preferred as inorganic fine particles, and acrylic resin beads, urethane resin beads, and silicone beads are preferred as organic fine particles. Silica and resin beads are particularly preferred.

[0064] (silica) Amorphous silica is more preferred as the matting agent mentioned above. Examples of amorphous silica include diatomaceous earth and activated clay, and among amorphous silicas, synthetic amorphous silica such as dry silica, wet silica, and silica gel can be used. Wet silica produced by the neutralization and decomposition reaction of an aqueous sodium silicate solution with an acid or alkali metal salt is preferred. Surface-treated wet silica can also be used. There are no particular restrictions on the method of surface-treating the silica particles, and any known method is acceptable. Examples include surface treatment with wax or silane coupling agent. A mixture of surface-treated and untreated wet silica may be used.

[0065] The oil absorption rate of the above-mentioned matting agent is preferably 200 mL / 100g to 400 mL / 100g, and more preferably 200 mL / 100g to 350 mL / 100g. If the oil absorption rate is less than 200 mL / 100g, a sufficient matting effect will not be observed, and if it exceeds 400 mL / 100g, the matting agent will absorb the binder resin, which tends to reduce the physical properties of the coating film, such as adhesion and weather resistance, and is therefore undesirable.

[0066] The average particle size of the above-mentioned matting agent is preferably in the range of 0.3 to 20 μm, and more preferably in the range of 2 to 15 μm. The average particle size is the value measured using a Nanotrac UPA EX-150 nanoparticle size distribution analyzer manufactured by Nikkiso Co., Ltd.

[0067] The content of the above-mentioned matting agent is preferably 1 to 30% by mass relative to the non-volatile components of the aqueous coating agent, and more preferably 2 to 20% by mass. If the content is less than 1% by mass, it may be difficult to obtain a sufficient matting effect, and if it exceeds 30% by mass, the matting agent tends to easily peel off from the surface of the coating film, which is undesirable.

[0068] (Other additives) In addition to the coating agent used in the present invention, various additives such as inorganic pigments, organic pigments, extender pigments, clay minerals, mold release agents, surfactants, antibacterial agents, stabilizers, flow regulators, dyes, leveling agents, rheology control agents, ultraviolet absorbers, antioxidants, or plasticizers may also be used as needed.

[0069] Additionally, UV absorbers and light stabilizers can be added as weather-resistant agents as needed. Common UV absorbers include benzotriazoles, benzoates, benzophenones, and triazines, while light stabilizers include hindered amines, and these can be added in any combination. The amount of UV absorber is not particularly limited, but for example, it is preferably in the range of 1% to 30% by mass relative to the non-volatile components of the coating agent used in the present invention, and more preferably in the range of 2% to 20% by mass. Similarly, the amount of light stabilizer is not particularly limited, but for example, it is preferably in the range of 1% to 20% by mass relative to the non-volatile components of the coating agent used in the present invention, and more preferably in the range of 2% to 10% by mass.

[0070] (Coating method) Specific examples of coating and printing methods for the coating agent used in the present invention include, as coating methods, roll coaters, gravure coaters, flexographic coaters, air doctor coaters, blade coaters, air knife coaters, squeeze coaters, impregnation coaters, transfer roll coaters, kiss coaters, curtain coaters, cast coaters, spray coaters, die coaters, offset printing presses, screen printing presses, etc., which can be used as appropriate.

[0071] (Coating film formation method) The coating layer is formed by drying and curing a coating film layer to which the coating agent used in this invention has been applied and printed. The temperature and time for drying and curing can be set appropriately within a range that does not cause deformation of the substrate layer, for example, the temperature can be 25°C to 140°C and the time 1 minute to 72 hours. Specific drying methods include using hot air or a drying oven (dryer) of a known coating machine.

[0072] (Coating film thickness) The thickness of the coating layer of the coating agent of the present invention is not particularly limited, but is preferably 0.1 to 100.0 μm, more preferably 0.3 to 50.0 μm, and particularly preferably 0.3 to 30.0 μm.

[0073] (Decorative sheet) The decorative sheet of the present invention is a decorative sheet having a coating layer of the aqueous coating agent of the present invention on a plastic substrate. The plastic substrate may have one or more coating layers of the aqueous coating agent of the present invention. If multiple layers are applied, all of the layers may be solid print layers, or they may be print layers printed using a die-cutting method. Furthermore, it is also preferable to combine the aqueous coating layer of the present invention with a coating layer of an aqueous coating agent similar to the aqueous coating agent of the present invention, for example, an aqueous coating agent containing a (meth)acrylic emulsion, a curing agent, and a silane coupling agent, wherein the silane coupling agent is contained in an amount of 5 to 30% by mass relative to the non-volatile components, but does not contain inorganic fine particles.

[0074] The aqueous coating agent of the present invention contains a (meth)acrylic emulsion, a curing agent, a silane coupling agent, and a polar group-containing olefin resin, and therefore exhibits excellent adhesion to plastic substrates. Accordingly, in applications requiring higher adhesion, it is preferable to coat the plastic substrate with the coating agent so as to be in direct contact with it to form a coating layer.

[0075] An example of a specific embodiment of the configuration envisioned for the decorative sheet of the present invention is shown below. Of course, this is not limited to the present invention. In the following, the coating layer of aqueous coating agent 3 is the coating layer of the aqueous coating agent of the present invention, which comprises (meth)acrylic emulsion, a curing agent and a silane coupling agent, inorganic fine particles and a polar group-containing olefin resin. The coating layer of the aqueous coating agent 4 is a coating layer of the aqueous coating agent of the present invention that contains (meth)acrylic emulsion, a curing agent and a silane coupling agent, wax and inorganic fine particles, and does not contain polar group-containing olefin resin. others, The coating layer of aqueous coating agent 1 is a coating layer of aqueous coating agent containing (meth)acrylic emulsion, a curing agent, a silane coupling agent, and a polar group-containing olefin resin. The coating layer of aqueous coating agent 2 is an aqueous coating layer containing a (meth)acrylic emulsion, a curing agent, and a silane coupling agent, and does not contain a polar group-containing olefin resin.

[0076] Base material 1 / Pattern layer / Adhesive layer / Base material 2 / Water-based coating agent 3 coating layer Base material 1 / Pattern layer / Adhesive layer / Base material 2 / Water-based coating agent 4 coating layer Substrate 1 / Pattern layer / Adhesive layer / Substrate 2 / Coating layer of water-based coating agent 1 / Coating layer of water-based coating agent 3 Substrate 1 / Pattern layer / Adhesive layer / Substrate 2 / Coating layer of water-based coating agent 1 / Coating layer of water-based coating agent 4 Substrate 1 / Pattern layer / Adhesive layer / Substrate 2 / Coating layer of water-based coating agent 3 / Coating layer of water-based coating agent 1 Substrate 1 / Pattern layer / Adhesive layer / Substrate 2 / Coating layer of water-based coating agent 3 / Coating layer of water-based coating agent 2 Substrate 1 / Pattern layer / Adhesive layer / Substrate 2 / Coating layer of water-based coating agent 3 / Coating layer of water-based coating agent 3 Substrate 1 / Pattern layer / Adhesive layer / Substrate 2 / Coating layer of water-based coating agent 3 / Coating layer of water-based coating agent 4 Base material 1 / Pattern layer / Coating layer of water-based coating agent 3 Base material 1 / Pattern layer / Water-based coating agent 4 coating layer Substrate 1 / Pattern layer / Coating layer of water-based coating agent 1 / Coating layer of water-based coating agent 3 Substrate 1 / Pattern layer / Coating layer of water-based coating agent 1 / Coating layer of water-based coating agent 4 Substrate 1 / Pattern layer / Coating layer of water-based coating agent 3 / Coating layer of water-based coating agent 1 Substrate 1 / Pattern layer / Coating layer of water-based coating agent 3 / Coating layer of water-based coating agent 2 Substrate 1 / Pattern layer / Coating layer of water-based coating agent 3 / Coating layer of water-based coating agent 3 Substrate 1 / Pattern layer / Coating layer of water-based coating agent 3 / Coating layer of water-based coating agent 4 Coating layer of substrate 1 / water-based coating agent 3 Coating layer of substrate 1 / water-based coating agent 4 Substrate 1 / Coating layer of water-based coating agent 1 / Coating layer of water-based coating agent 3 Substrate 1 / Coating layer of water-based coating agent 1 / Coating layer of water-based coating agent 4 Substrate 1 / Coating layer of water-based coating agent 3 / Coating layer of water-based coating agent 1 Substrate 1 / Coating layer of water-based coating agent 3 / Coating layer of water-based coating agent 2 Substrate 1 / Coating layer of water-based coating agent 3 / Coating layer of water-based coating agent 3 Substrate 1 / Coating layer of water-based coating agent 3 / Coating layer of water-based coating agent 4

[0077] In particular, a decorative sheet having a coating layer composed of aqueous coating agent 1 or aqueous coating agent 3 and a coating layer composed of aqueous coating agent 2 or aqueous coating agent 4 on a plastic substrate is preferred.

[0078] (base material) The substrate used in the present invention is not particularly limited as long as it is a plastic substrate, and any substrate can be used as appropriate depending on the desired purpose. Examples include films and sheets made of polyolefin resins such as polyethylene (LLDPE: low-density polyethylene, HDPE: high-density polyethylene, MDOPE: uniaxially oriented polyethylene, OPE: biaxially oriented polyethylene), polypropylene (CPP: unoriented polypropylene film, OPP: biaxially oriented polypropylene film), polybutene, polymethylpentene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-propylene-butene copolymer, and polyolefin-based thermoplastic elastomers. Other examples include film and sheet-like substrates made from polyethylene terephthalate (PET), polystyrene, polyamide, polyacrylonitrile, ethylene vinyl alcohol copolymer, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, etc. These substrates may be single-layer or multi-layer laminated substrates.

[0079] To form film or sheet-like substrates, methods such as calendering, inflation molding, and T-die extrusion can be used. The thickness of these materials is not particularly limited and can be set according to the product characteristics, but is usually 40 to 150 μm, preferably 50 to 100 μm.

[0080] The base material may contain additives as needed. Examples of additives include fillers such as calcium carbonate and clay, flame retardants such as magnesium hydroxide, as well as antioxidants, lubricants, foaming agents, and colorants. The amount of additives can be appropriately determined according to the product characteristics.

[0081] It is preferable that one or both sides of the substrate are subjected to surface treatments such as corona discharge treatment, ozone treatment, plasma treatment, ionizing radiation treatment, or dichromate treatment. Plastic substrates in which corona treatment has been performed on the coated surface are particularly preferred. The aqueous coating agent for building materials of the present invention contains a specific amount of silane coupling agent, and is therefore presumed to react with functional groups (e.g., hydroxyl groups and carboxyl groups) that are expected to be formed on a corona-discharge-treated plastic substrate, thereby improving adhesion.

[0082] When performing the corona discharge treatment described above, the surface tension of the substrate surface should be set to 30 dyne or more, preferably 40 dyne or more. Surface treatment should be carried out according to the standard methods for each treatment.

[0083] (Picture layer) The substrate used in this invention may have a pattern layer. The pattern layer is usually provided by printing. The pattern layer may be a single layer or multiple layers may be laminated. Furthermore, it may be solid printing or a pattern layer printed only on a part of the substrate. The pattern layer obtained by printing may also be referred to as the printed layer. The pattern layer can be printed onto the substrate by known coating and printing methods. These methods include coating methods such as roll coating, gravure coating, and spray coating, and printing methods such as gravure printing, offset printing, letterpress printing, screen printing, and inkjet printing. The patterns applied to the pattern layer can be freely chosen, but examples include wood grain patterns, patterns that mimic the surface of rocks such as marble, fabric patterns that mimic the weave or pattern on fabric, tile patterns, floral patterns of flowers or flower clusters arranged at equal intervals, and letters. In addition, a solid color printing layer, such as white, may be placed beneath the pattern printing layer to make the pattern stand out.

[0084] As the inks that make up the pattern layer, known inks can be used, such as oil-based inks, water-based inks, and active energy ray-curing inks. In addition, liquid printing inks such as flexographic printing inks and gravure printing inks, lithographic offset printing inks, and inkjet inks can be selected according to the printing method.

[0085] (Transparent resin layer) The transparent resin layer is preferably made of polyolefin, such as polypropylene, polyethylene, polybutene, or various α-olefin copolymers (polymers of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, etc.). The transparent resin layer may contain various additives as needed, such as UV absorbers, heat stabilizers, light stabilizers, blocking inhibitors, catalyst scavengers, colorants, light scattering agents, and gloss modifiers. The method for forming the transparent resin layer is not particularly limited, and conventional methods such as calendering or extrusion deposition can be used. The transparent resin layer may have surface irregularities to enhance its aesthetic appeal. Methods for creating these irregularities include, for example, applying thermal embossing after extruding the transparent resin layer, or using a cooling roll with irregularities during extrusion molding to perform embossing simultaneously with the extrusion process.

[0086] (Decorative material) The decorative sheet of the present invention can be bonded to wood, plywood, fiberboard, metal plate, etc., to obtain a decorative material. The decorative sheet of the present invention can be used in residential interior materials, furniture, home appliances, office supplies, toys, vehicle interior materials, etc., where weather resistance and scratch resistance are required, and is particularly suitable for use in residential interior materials, furniture, and home appliances. [Examples]

[0087] The present invention will be described in more detail by the following examples. In the examples, "parts" refers to "parts by mass," and "%" refers to "percentage by mass."

[0088] (Examples) (Preparation of water-based coating agent) [Coating agent 1A] 47.7 parts of nonvolatile components from acrylic emulsion resin A (glass transition temperature 82°C, acid value 25, nonvolatile components 43%), 15.9 parts of nonvolatile components from acrylic emulsion resin B (glass transition temperature 21°C, acid value 31, nonvolatile components 43%), 6.6 parts of nonvolatile components from PP resin A (chlorinated polyolefin resin, maleic acid / polypropylene ratio = 0.2), 6.0 parts of nonvolatile components from UV absorber (Tinuvin 1130, manufactured by BASF Japan Ltd.), 2.6 parts of nonvolatile components from light stabilizer (Tinuvin 292, manufactured by BASF Japan Ltd.), and epoxy curing agent A (epoxy equivalent 167 10.6 parts of the non-volatile component (g / eq.) and 10.6 parts of the non-volatile component of silane coupling agent A (3-glycidoxypropyltriethoxysilane) were mixed together to make a total of 100 parts of non-volatile components. The mixture was then thoroughly stirred with a stirrer for 15 minutes to prepare coating agent 1A, which is an aqueous coating agent composition. Furthermore, the maleic acid / polypropylene ratio of polar group-containing olefin resins was determined using an infrared spectrophotometer (FT / IR-460Plus, manufactured by JASCO Corporation) by summing the maleic acid peaks (1710 cm²). -1 +1740cm -1 +1780cm -1 ) Polypropylene peak (1460cm ―1 This value was obtained by dividing by [a certain factor].

[0089] [Coating agent 1B~4H] Coating agents 1B, 2A-2B, 3A-3E, and 4A-4H were prepared using the same procedure as for coating agent 1A, according to the formulations shown in Tables 1 and 2 described below. Coating agents 3A to 3E and 4A to 4H are aqueous coating agents for building materials according to the embodiments of this application, while coating agents 1A to 1B and 2A to 2B are aqueous coating agents for building materials according to the reference examples.

[0090] [Table 1]

[0091] [Table 2]

[0092] The abbreviations used in Tables 1 and 2 are shown below. Acrylic emulsion A: Tg 82℃, acid value 25, non-volatile components 43% Acrylic emulsion B: Tg 21℃, acid value 31, non-volatile components 43% • UV absorber: Tinuvin 1130 • Light stabilizer: Tinuvin 292 • Epoxy hardener A: Epoxy equivalent 167 g / eq. • Epoxy-based hardener B: Epoxy equivalent 141 g / eq. • Aziridine-based curing agent: Aziridine content 6.0 mmol / g • PP resin A: Chlorinated polyolefin resin, maleic acid / polypropylene ratio = 0.2 • PP resin B: Chlorinated polyolefin resin, maleic acid / polypropylene ratio = 0.3 • PP resin C: Chlorinated polyolefin resin, maleic acid / polypropylene ratio = 0.3 • PP resin D: Maleic acid-modified polyolefin resin, maleic acid / polypropylene ratio = 0.45 • PP resin E: Maleic acid-modified polyolefin resin, maleic acid / polypropylene ratio = 0.16 • Silica: Colloidal silica, average particle size 3.9 μm, oil absorption capacity 320 ml / 100 g Silane coupling agent A: 3-glycidoxypropyltriethoxysilane • Silane coupling agent B: 8-Glycidoxyoctyltrimethoxysilane ·Inorganic fine particles A: Silton, oil absorption 45mL / 100g, average particle size 3.0μm • Inorganic microparticles B: Glass beads, average particle size 5.0 μm • Inorganic microparticles C: Alumina microparticles, average particle size 1.2 μm ·Inorganic fine particles D: Silicon fine particles, oil absorption 58μm / 100g, average particle size 4.5μm • Wax A: Polyethylene wax, average particle size 4 μm • Wax B: Polyethylene wax, average particle size 8 μm • Wax C: Polyethylene wax, average particle size 1 μm

[0093] (Example 1) (Creation of decorative sheets) An opaque polyethylene sheet was used as the base layer, and a wood grain pattern layer was created using acrylic ink. After that, a dry laminating adhesive was applied to the pattern layer. A polypropylene sheet was then laminated on top as a transparent resin layer to create a plastic base material. Corona discharge treatment was performed on the laminated polypropylene layer of a plastic substrate so that the surface tension of the substrate sheet surface was 40 dyne or more. A bar coater was used to apply 5 g / m² of coating agent 1B and coating agent 4A to the laminated surface of the corona discharge-treated polypropylene layer. 3 After application, the material was dried using a drying oven and then aged at 40°C for 3 days.

[0094] [Evaluation Method] This document describes an evaluation method for decorative sheets using the aqueous coating agent for building materials of the present invention. The evaluation results are shown in the table.

[0095] [Adhesion Test] In accordance with JIS K 5600-5-6, the adhesion of the coating layer to the substrate was evaluated on a five-point scale. Tests were conducted both after the coating layer was created (initial adhesion) and after 10 cycles of weather resistance testing (weather resistance adhesion). The weather resistance test consisted of 10 cycles, each cycle comprising 20 hours of irradiation, 4 hours of condensation, and 15 seconds of showering before and after irradiation, and was conducted under the following conditions. (Weathering resistance test conditions) • Test equipment: iSuper UV Tester SUV-W261 <During irradiation> • Black panel temperature: 63℃ ·Irradiance: 60mW / cm 2 ·Battle humidity: 50%RH • Time: 20 hours <During condensation> ·Illuminance: 0mW / cm 2 ·Battle humidity: 98%RH • Duration: 4 hours (Evaluation Criteria) A: There is no delamination on any of the grids. B: There is very slight delamination at the corners of the grid. C: There is some peeling, but it does not affect practical use. D: Peeling occurs over 1 / 3 to 1 / 2 of the test area. E: Peeling occurs over more than half of the test area. In this evaluation, a score of "C" or higher was considered a passing grade.

[0096] (Creation of samples for evaluating decorative laminates) The obtained decorative sheet was then coated with a mixture of adhesive "Licabond BA-10L" and isocyanate-based curing agent "BA-11B" (manufactured by Japan Coating Resin) on the side without the coating layer, and then attached to plywood "MDF" (manufactured by Benichong). A sample for decorative panel evaluation was obtained by aging at room temperature.

[0097] [MEK rubbing properties] The decorative laminate evaluation sample is placed horizontally, and the pressure is 400g / cm². 2 A gauze moistened with MEK (methyl ethyl ketone) was attached to the tip of a weight, and a rubbing test was performed on the surface of the decorative sheet. The condition of the coating after the test was visually inspected, and the number of rubbing cycles required when 50% of the surface area was peeled off was evaluated on the following five-point scale. (Evaluation Criteria) A: More than 50 round trips B: 40 round trips or more but less than 50 round trips C: 30 round trips or more, but less than 40 round trips D: 20 round trips or more but less than 30 round trips E: Less than 20 round trips In this evaluation, a score of "C" or higher was considered a passing grade.

[0098] [Sliding surface properties] The decorative laminate evaluation sample was placed horizontally, and the pressure was 1000 g / cm². 2A 1cm x 1cm piece of the same decorative sheet as the test sample was attached to the tip of a weight, and a rubbing test was performed on the surface of the decorative sheet 500 times. The condition of the coating after the test was visually inspected and evaluated in the following three stages. (Evaluation Criteria) A: There is no change in the coating. B: A slight change in gloss is observed. C: Several scratches are visible. D: More than 10 scratches are visible. E: Significant chipping and powdering of the paint film are visible. In this evaluation, a score of "B" or higher was considered a passing grade.

[0099] [Scratch resistance (Hoffmann scratch)] A sample of decorative laminate was placed horizontally, and a scratch test was conducted using a Hoffmann scratch hardness tester (manufactured by BYK instruments). The heaviest load that did not cause significant scratches on the surface of the decorative sheet was measured and evaluated on the following five-point scale. A: The load at which the coating surface peels off is 1000g or more. B: The load at which the coating film surface peels off is between 800g and 1000g. C: The load at which the coating film surface peels off is between 600g and 800g. D: The load at which the coating film surface peels off is between 400g and 600g. E: The load at which the coating film surface peels off is less than 400g. In this evaluation, a score of "C" or higher was considered a passing grade.

[0100] [Scratch resistance (steel wool)] The decorative laminate evaluation sample was placed horizontally, and the pressure was 1000 g / cm². 2 A weight (#0000) was attached to the tip, and a rubbing test was performed on the surface of the decorative sheet 10 times back and forth. The condition of the coating after the test was visually inspected and evaluated in the following three stages. (Evaluation Criteria) A: There is no change in the coating. B: A slight change in gloss is observed. C: Several scratches are visible. D: More than 10 scratches are visible. E: Significant chipping and powdering of the paint film are visible. In this evaluation, a score of "B" or higher was considered a passing grade.

[0101] [Alkali resistance] A 2% sodium hydroxide solution was dropped onto the surface of a horizontally positioned decorative panel sample, covered with a watch glass, and left to stand for 24 hours. Afterward, the sample was wiped with a damp cloth. The film condition after the test was visually inspected and evaluated on a five-point scale. (Evaluation Criteria) A: There is no change in the coating. B: Slight blistering of the paint film and very minor changes in gloss are observed. C: Slight blistering of the coating and minor changes in gloss may be observed, but this does not affect practical use. D: Significant changes in the paint film, such as blistering and gloss, are observed. E: Significant blistering or changes in gloss are observed in the paint film. In this evaluation, a score of "C" or higher was considered a passing grade.

[0102] The results are shown in the table. Blank spaces in the table indicate that the ingredient was not included.

[0103] [Table 3]

[0104] [Table 4]

[0105] [Table 5]

[0106] Examples 1 to 14, which are decorative sheets of the present invention, exhibited excellent adhesion to plastic substrates and possessed high durability, high scratch resistance, high sliding resistance, high solvent resistance, and high alkali resistance. On the other hand, the decorative sheets of the comparative examples were inferior in terms of scratch resistance, sliding resistance, etc.

Claims

1. It contains (meth)acrylic emulsion, a curing agent and a silane coupling agent, wherein the silane coupling agent is present in an amount of 5 to 30% by mass relative to the non-volatile components. A water-based coating agent for building materials characterized by containing inorganic fine particles in an amount of 0.5 to 10.0% by mass relative to the non-volatile components.

2. The aqueous coating agent for building materials according to claim 1, which contains wax in an amount of 0.1 to 20.0% by mass relative to the non-volatile components.

3. The aqueous coating agent for building materials according to claim 1, which contains a matting agent in an amount of 1 to 30% by mass relative to the non-volatile component.

4. The aqueous coating agent for building materials according to claim 1, comprising inorganic fine particles and wax, wherein the wax content is 1 / 3 or more of the inorganic fine particles content, and the average particle diameter of the wax is 1 / 2 or more of the average particle diameter of the inorganic fine particles.

5. The aqueous coating agent for building materials according to claim 1, which contains a polar group-containing olefin resin.

6. The aqueous coating agent for building materials according to claim 1, wherein the curing agent is an epoxy-based curing agent or an aziridine-based curing agent.

7. A decorative sheet having a coating layer of an aqueous coating agent on a plastic substrate, wherein the aqueous coating agent is the aqueous coating agent described in any one of claims 1 to 6.

8. A decorative sheet having a coating layer 1 of aqueous coating agent 1 and a coating layer 2 of aqueous coating agent 2 on a plastic substrate, A decorative sheet characterized in that the aqueous coating agent 1 and / or the aqueous coating agent 2 are the aqueous coating agent described in any one of claims 1 to 6.

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