Active energy ray curable coating agent and cosmetic material using the same

Abstract

To provide an active energy ray curable coating agent excellent in leveling property, abrasion resistance and matte property. [Solution] An active energy ray-curable coating agent used to form a surface protective layer of a decorative material having a substrate, a colored layer, and a surface protective layer, The active energy ray-curable coating agent comprises a (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms and / or a mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom, a (meth)acrylate (B) having 3 or more functional groups, and fine particles.

Description

[Technical Field]

[0001] The present invention relates to an active energy ray-curable coating agent used for a surface protective layer of a decorative material. [Background technology]

[0002] The present invention relates to a coating agent applied to the surface of a decorative material. Decorative materials are often used for the interior decoration and surface decoration of buildings, such as furniture and fixtures. They typically require surface protection properties, such as matte finish, as well as stain resistance, weather resistance, solvent resistance, and abrasion resistance. To meet these requirements, a surface protection layer is applied to the surface of the substrate. From an environmental and productivity perspective, active energy ray-curable coating agents are preferably used as the surface protection layer. These coating agents typically contain a matting agent, such as silica, primarily for the purpose of reducing gloss and enhancing matte finish. However, because matting agents can affect leveling or cause a decrease in various physical properties, such as stain resistance, research has also been conducted to achieve low gloss without the use of a matting agent (Patent Document 1). On the other hand, in recent years, there has been an increasing demand for a lower gloss appearance (high matte) in pursuit of a more luxurious feel, and there is a demand for materials that combine the desired matte finish, printability (leveling ability), and the surface protection properties unique to decorative materials.

[0003] Patent Document 1 describes an electron beam-curable matte coating agent containing a compound (A) with a weight-average molecular weight of 2000 or more and a bifunctional (meth)acrylic monomer (B). However, because this coating agent does not contain fine particles, it does not have both the desired matte and leveling properties, and improvements have been sought.

[0004] Furthermore, Patent Document 2 describes a decorative sheet having at least a colored layer and a surface protective layer in this order on a substrate, in which the surface protective layer is formed using a mixed resin of a tetrafunctional acrylate and a difunctional acrylate, a thermoplastic resin, and an ionizing radiation curable resin containing silica. However, this coating agent does not provide the desired matte properties and surface protective properties, and improvements have been sought. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-166728 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-198440 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an active energy ray-curable coating agent for use in a surface protective layer of a decorative material, which has excellent leveling properties, abrasion resistance, and matte properties. [Means for solving the problem]

[0007] The present invention provides an active energy ray-curable coating agent used to form a surface protective layer of a decorative material having a substrate, a colored layer, and a surface protective layer, the coating agent comprising: The present invention relates to an active energy ray-curable coating agent comprising: a (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms and / or a mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom; a (meth)acrylate (B) having 3 or more functional groups; and fine particles.

[0008] The present invention relates to the active energy ray-curable coating agent, which has a viscosity of 200 to 2000 mPa·s as measured with a Brookfield viscometer at 25°C, a rotation speed of 6 rpm, and a rotor No. 3.

[0009] The present invention relates to the active energy ray-curable coating agent, wherein the mass ratio ((A1)+(A2):(B)) of the total amount of the (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms and the mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom to the (meth)acrylate (B) having 3 or more functional groups is 5:95 to 50:50.

[0010] The present invention relates to the active energy ray-curable coating agent, wherein at least one selected from the group consisting of (poly)alkylene glycol di(meth)acrylates (A1) having an alkylene group with 4 or more carbon atoms, mono(meth)acrylates (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom, and (meth)acrylates (B) having 3 or more functional groups comprises a structural unit derived from biomass.

[0011] The present invention relates to an active energy ray-curable coating agent, wherein the total content of the (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms, the mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom, and the (meth)acrylate (B) having 3 or more functional groups is 60 mass% or more based on the total mass of the active energy ray-curable coating agent.

[0012] The present invention relates to the active energy ray-curable coating agent, wherein the fine particles are silica fine particles.

[0013] The present invention relates to the active energy ray-curable coating agent, wherein the content of the silica fine particles in the total mass of the active energy ray-curable coating agent is 10 to 40 mass %.

[0014] The present invention relates to a decorative material having a substrate, a colored layer, and a surface protective layer formed from the active energy ray-curable coating agent. [Effects of the Invention]

[0015] The present invention provides an active energy ray-curable coating agent that is excellent in leveling property, abrasion resistance, and matte property, and also provides an active energy ray-curable coating agent that is highly environmentally friendly. DETAILED DESCRIPTION OF THE INVENTION

[0016] The following examples are provided to explain the embodiments of the present invention in detail, but the following descriptions are merely examples or representative examples of the embodiments of the present invention, and the present invention is not limited to these details as long as it does not deviate from the gist of the invention. In the present invention, "(meth)acrylate" refers to acrylate and / or methacrylate. Furthermore, "active energy ray-curable coating agent" may be simply referred to as "coating agent," but these terms have the same meaning.

[0017] The present invention provides an active energy ray-curable coating agent for use in the surface protective layer of a decorative material having a substrate and a surface protective layer. This active energy ray-curable coating agent contains a (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms and / or a mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms and optionally containing a heteroatom, a (meth)acrylate (B) having 3 or more functional groups, and fine particles. This coating agent exhibits a moderate penetration effect on the substrate and / or a layer such as a colored layer, thereby achieving a matte finish derived from the fine particles. Furthermore, this coating agent has a viscosity of 200 to 2000 mPa·s measured using a Brookfield viscometer at 25°C, 6 rpm, and rotor No. 3, thereby providing excellent leveling properties, which, combined with the penetration effect, further improves the matte finish. Furthermore, at least one selected from the group consisting of (poly)alkylene glycol di(meth)acrylates (A1) having an alkylene group with 4 or more carbon atoms, mono(meth)acrylates (A2) having a hydrocarbon group with 4 or more carbon atoms that may contain a heteroatom, and (meth)acrylates (B) having 3 or more functional groups may contain a structural unit derived from biomass, which is preferable from the viewpoint of environmental conservation. Furthermore, the fine particles are silica fine particles, and the content of the silica fine particles in the total mass of the active energy ray-curable coating agent is 10 to 40 mass%, thereby further improving leveling properties and matting properties. A decorative material having a surface protective layer formed using this active energy ray-curable coating agent has excellent abrasion resistance and matting properties. However, the present invention is not limited by the above considerations and mechanisms.

[0018] (Active energy ray curable coating agent) The active energy ray-curable coating agent of the present invention comprises a (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms and / or a mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom, a (meth)acrylate (B) having 3 or more functional groups, and fine particles. A preferred embodiment includes a (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms, a (meth)acrylate (B) having 3 or more functional groups, and fine particles. Furthermore, it is preferable that at least one selected from the group consisting of (poly)alkylene glycol di(meth)acrylates (A1) having an alkylene group with 4 or more carbon atoms, mono(meth)acrylates (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom, and (meth)acrylates (B) having 3 or more functional groups contains a biomass-derived structural unit.

[0019] (Biomass-derived building blocks) In view of environmental conservation such as carbon neutrality, it is preferable that the active energy ray-curable coating agent of the present invention uses raw materials containing structural units derived from biomass. In the present invention, "comprising a biomass-derived structural unit" means that the material is produced using a biomass-derived raw material as part or all of the raw material. The biomass-derived structural unit is preferably a structural unit derived from a biomass alcohol, and more preferably a structural unit derived from a biomass monoalcohol and / or a biomass polyol. A structural unit derived from a biomass polyol is even more preferred.

[0020] (Biomass alcohol) Suitable examples of biomass monoalcohols as the biomass alcohol include methanol, ethanol, butanol, dodecanol, tetradecanol, and hexadecanol, and preferably include dodecanol, tetradecanol, and hexadecanol. Suitable examples of biomass polyols as the biomass alcohol include ethylene glycol, glycerin, 1,4-butanediol, 1,10-decanediol, and polytetramethylene glycol, and preferably include glycerin and 1,10-decanediol.

[0021] The content of the biomass-derived structural units in the total mass of the coating agent is preferably 2% by mass or more, more preferably 5% by mass or more, and even more preferably 8% by mass or more.

[0022] (Poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms) The (poly)alkylene glycol di(meth)acrylate (A1) used in the present invention is not particularly limited as long as it is an alkylene glycol di(meth)acrylate and / or polyalkylene glycol di(meth)acrylate having an alkylene group with 4 or more carbon atoms, and known compounds can be used. Having an alkylene group with 4 or more carbon atoms improves the durability of the cured film and improves abrasion resistance. Furthermore, the viscosity of the coating agent is less likely to decrease, and penetration into the substrate and colored layer can be controlled within an appropriate range, making it easier to balance abrasion resistance and matte properties. The alkylene group preferably has 4 to 25 carbon atoms, more preferably 4 to 20 carbon atoms, and more preferably 6 to 18 carbon atoms. The alkylene group having 4 or more carbon atoms may be linear, branched, or alicyclic, and is preferably linear or branched. The (poly)alkylene glycol di(meth)acrylate (A1) may also contain a linear or branched alkylene group with 3 or less carbon atoms.

[0023] The (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms is preferably a compound represented by the following general formula (1). General formula (1) H2C=CR 1 COO(R 2 O) a R 3 (OR 4 ) b OCOCR 1 =CH2 [In the above general formula, R 1 R represents a hydrogen atom or a methyl group. 2 and R 4 each independently represents an alkylene group having 2 or 3 carbon atoms, R 3 represents an alkylene group having 4 to 25 carbon atoms. a and b represent 0 or a natural number, and a+b=0 to 30.]

[0024] Examples of (poly)alkylene glycol di(meth)acrylates (A1) having an alkylene group with 4 or more carbon atoms include 1,4-butanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol diacrylate, 2-methyl-1,8-octanediol di(meth)acrylate, and tricyclodecane dimethanol di(meth)acrylate. Among these, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and 1,10-decanediol di(meth)acrylate are more preferred, and 1,6-hexanediol di(meth)acrylate is particularly preferred. It is also preferred to use polyalkylene glycol di(meth)acrylates in which alkylene glycols having 4 or more carbon atoms are modified with alkylene oxide. Suitable examples of the alkylene oxide include ethylene oxide and propylene oxide. In the above general formula (1), a+b is preferably 0 to 20, more preferably 0 to 10. These may be used alone or in combination of two or more. Examples of polyalkylene glycol di(meth)acrylate include 1,4-butanediol ethylene oxide (EO)-modified di(meth)acrylate and 1,6-hexanediol ethylene oxide (EO)-modified diacrylate.

[0025] Among the (poly)alkylene glycol di(meth)acrylates (A1) having an alkylene group with 4 or more carbon atoms, those containing a biomass-derived structural unit include, for example, 1,10-decanediol diacrylate, which is preferred from the viewpoint of environmental conservation.

[0026] The molecular weight of the (poly)alkylene glycol di(meth)acrylate (A1) in which the alkylene group has 4 or more carbon atoms is preferably from 150 to 800, more preferably from 200 to 600, and even more preferably from 200 to 500. When the molecular weight is within this range, the viscosity of the coating agent does not become too high, and the leveling property becomes good.

[0027] In the present invention, the content of the (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms in the total mass of the active energy ray-curable coating agent is preferably 3% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 45% by mass or less, and even more preferably 15% by mass or more and 40% by mass or less. When it is 3% by mass or more, good matting properties are obtained, and when it is 50% by mass or less, good abrasion resistance is obtained.

[0028] (Mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom) The mono(meth)acrylate (A2) used in the present invention is not particularly limited as long as it contains a hydrocarbon group having 4 or more carbon atoms which may contain a heteroatom, and known compounds can be used. Having 4 or more carbon atoms improves the durability of the cured film and improves abrasion resistance. Furthermore, the viscosity of the coating agent is less likely to decrease, and penetration into the substrate and / or colored layer can be controlled within an appropriate range, making it easier to balance matte finish and abrasion resistance. The hydrocarbon group preferably has 4 to 25 carbon atoms, more preferably 6 to 18, and even more preferably 6 to 12. The hydrocarbon group may be linear, branched, or cyclic, and examples thereof include linear or branched alkyl groups, cyclic alkyl groups, and groups having a heterocyclic structure.

[0029] Examples of hydrocarbon groups having 4 or more carbon atoms include alkyl groups such as butyl, hexyl, dodecyl, tetradecyl, hexadecyl, and octadecyl, and groups having a cyclic structure such as tetrahydrofuryl and isobornyl, with dodecyl, octadecyl, tetrahydrofuryl, and isobornyl being preferred. These are preferably structural units derived from the biomass alcohol. The heteroatom is not particularly limited, but oxygen or nitrogen is preferred.

[0030] Examples of the mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms and which may contain a heteroatom include alkyl mono(meth)acrylates having 4 to 18 carbon atoms, such as butyl(meth)acrylate, hexyl(meth)acrylate, octyl(meth)acrylate, dodecyl(meth)acrylate, stearyl(meth)acrylate, tetradecyl(meth)acrylate, hexadecyl(meth)acrylate, and octadecyl(meth)acrylate. Among these, hexyl(meth)acrylate, octyl(meth)acrylate, and dodecyl(meth)acrylate are particularly preferred. These may be used alone or in combination of two or more.

[0031] Examples of the mono(meth)acrylate (A2) containing a structural unit derived from biomass include dodecyl(meth)acrylate, tetradecyl acrylate, hexadecyl methacrylate, and octadecyl methacrylate, which are preferred from the viewpoint of environmental conservation.

[0032] The molecular weight of the mono(meth)acrylate (A2) is preferably from 150 to 800, more preferably from 200 to 600, and even more preferably from 200 to 500. When the molecular weight is within this range, the viscosity of the coating agent does not become too high, and the leveling property becomes good.

[0033] When the mono(meth)acrylate (A2) is contained, the content of the mono(meth)acrylate (A2) in the total mass of the active energy ray-curable coating agent is preferably 2% by mass or more and 35% by mass or less, more preferably 5% by mass or more and 25% by mass or less, and even more preferably 7% by mass or more and 15% by mass or less. When the content is 2% by mass or more, the matte property is good, and when it is 35% by mass or less, the abrasion resistance is good.

[0034] ((Meth)acrylate (B) with 3 or more functional groups) The (meth)acrylate (B) used in the present invention is not particularly limited as long as it has three or more functional groups, and known compounds can be used. The number of functional groups refers to the number of polymerizable (meth)acrylate groups in the (meth)acrylate compound, and the number of functional groups is preferably 3 to 8, and more preferably 3 to 6. When the number of functional groups is 3 or more, the abrasion resistance of the cured film is improved, and when the number of functional groups is 8 or less, it is easy to suppress shrinkage of the film during curing. The number of functional groups is preferably 3 or 4, and more preferably 3. The (meth)acrylate (B) having three or more functional groups preferably contains a structural unit derived from an alkylene oxide (also referred to as alkylene oxide modified). Suitable examples of the alkylene oxide include alkylene oxides having 2 to 3 carbon atoms, such as ethylene oxide and propylene oxide.

[0035] Examples of (meth)acrylates having three functional groups include trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, glycerin propoxy tri(meth)acrylate, and pentaerythritol tri(meth)acrylate. Among these, trimethylolpropane tri(meth)acrylate, glycerin propoxy tri(meth)acrylate, and glycerin tri(meth)acrylate are preferred. Furthermore, it is preferred to use alkylene oxide-modified (meth)acrylates. Suitable alkylene oxides include ethylene oxide (EO) and propylene oxide (PO), and examples thereof include trimethylolpropane ethylene oxide-modified triacrylate.

[0036] Examples of (meth)acrylates having four functional groups include pentaerythritol tetra(meth)acrylate, diglycerin tetra(meth)acrylate, and ditrimethylolpropane tetra(meth)acrylate, and among these, pentaerythritol tetra(meth)acrylate and diglycerin tetra(meth)acrylate are preferred. It is also preferred to use alkylene oxide-modified acrylates.

[0037] Examples of (meth)acrylates having five or six functional groups include dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc. It is also preferable to use alkylene oxide-modified acrylates.

[0038] The (meth)acrylate (B) having three or more functional groups may be used alone, or two or more types having the same number of functional groups may be used in combination, or two or more types having different numbers of functional groups may be used in combination.

[0039] Among the (meth)acrylates (B) having three or more functional groups, those containing structural units derived from biomass include, for example, glycerin propoxy tri(meth)acrylate and glycerin tri(meth)acrylate, which are preferred from the viewpoint of environmental conservation.

[0040] The molecular weight of the (meth)acrylate (B) having three or more functional groups is preferably from 200 to 800, more preferably from 250 to 700, and even more preferably from 250 to 600. When the molecular weight is within this range, the viscosity of the coating agent does not become too high, and the leveling property becomes good.

[0041] In the present invention, the content of the (meth)acrylate (B) having three or more functional groups in the total mass of the active energy ray-curable coating agent is preferably 30% by mass to 95% by mass, more preferably 40% by mass to 85% by mass, and even more preferably 50% by mass to 75% by mass. When it is 30% by mass or more, good abrasion resistance is achieved, and when it is 95% by mass or less, good matting properties are achieved.

[0042] In the active energy ray-curable coating agent of the present invention, the mass ratio ((A1)+(A2):(B)) of the total amount of the (poly)alkylene glycol di(meth)acrylate (A1) whose alkylene group has 4 or more carbon atoms and the mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms, which may contain a heteroatom, to the (meth)acrylate (B) having 3 or more functional groups, is preferably in the range of 5:95 to 50:50, more preferably in the range of 10:90 to 45:55, and even more preferably in the range of 20:80 to 40:60. By being in the above range, not only is leveling ability good, but it is also easy to achieve both abrasion resistance and matte finish.

[0043] In the present invention, the total content of the (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms, the mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms and which may contain a heteroatom, and the (meth)acrylate (B) having 3 or more functional groups, based on the total mass of the active energy ray-curable coating agent, is preferably 60 mass% or more, more preferably 70 mass% or more, and even more preferably 75 mass% or more. By being in the above range, the leveling property and abrasion resistance are improved.

[0044] (Other resin components) In the present invention, resin components other than the above (A1), (A2), and (B) may be included to the extent that the effects of the present invention are not impaired. Examples of such resins include, but are not limited to, polymerizable compounds such as urethane acrylate and epoxy acrylate, and thermoplastic resins. Furthermore, the amount of resin components other than (A1), (A2), and (B) is 10% by mass or less, preferably 7% by mass or less, more preferably 5% by mass or less, even more preferably 2% by mass or less, and particularly preferably 1% by mass, of the total mass of the active energy ray-curable coating agent excluding fine particles.

[0045] (fine particles) The fine particles used in the present invention not only have the effect of imparting matte properties to the surface protective layer of the present invention, but also have the effect of improving durability such as abrasion resistance. As the fine particles, known organic fine particles and / or inorganic fine particles can be used. Examples of the organic fine particles include synthetic resin beads such as acrylic resin, urethane resin, and polyethylene resin, and examples of the inorganic fine particles include fine particles of silica, calcium carbonate, barium sulfate, and alumina. Among these, from the viewpoint of reducing gloss, it is preferable to use inorganic fine particles, and silica fine particles are more preferable. The fine particles may be used alone or in combination of two or more kinds.

[0046] The content of the fine particles is preferably 10 to 40% by mass, more preferably 15 to 38% by mass, even more preferably 18 to 35% by mass, and particularly preferably 20 to 30% by mass, based on the total mass of the active energy ray-curable coating agent. A content of 10% by mass or more improves the matting properties, while a content of 40% by mass or less improves the leveling properties and transparency of the surface protective layer. Furthermore, abrasion resistance is improved by being within the above range.

[0047] The average particle size of the fine particles is not particularly limited and may be appropriately selected depending on the film thickness of the surface protective layer and the desired gloss value, but is preferably 3 μm to 20 μm, more preferably 5 μm to 15 μm, and even more preferably 6 μm to 12 μm. A particle size within this range enhances the effect of reducing gloss. Here, the average particle size refers to the D50 value in the particle size distribution measured by the light scattering method, and can be measured using, for example, a Microtrack Bell T330EXII.

[0048] (Silica fine particles) The silica microparticles are not particularly limited in terms of manufacturing method or shape, and known silica particles can be used, but from the viewpoint of matte finish, it is preferable to use amorphous silica microparticles.In addition, silica microparticles include those whose surfaces are physically or chemically treated with a surface treatment agent (organic or inorganic) such as a silane coupling agent, microcrystalline, alumina, wax, etc., and those that are untreated, and both can be used in the present invention.The term "treated" refers to coating with a surface treatment agent or having a chemical bond with a surface treatment agent, and "untreated" refers to the absence of the coating or chemical bond.

[0049] The average particle size of the silica fine particles is preferably 3 μm to 20 μm, more preferably 5 μm to 15 μm, and even more preferably 6 μm to 12 μm. From the viewpoint of matting properties, it is preferable that the average particle size of the silica fine particles is appropriately selected depending on the film thickness, and by having the average particle size within this range, the matting effect (low gloss) is enhanced and furthermore, abrasion resistance is improved. The average particle size is the D50 value in the particle size distribution measured by the light scattering method, as described above.

[0050] The oil absorption of the silica fine particles is preferably 100 to 400 ml / g, more preferably 150 to 350 ml / g, and even more preferably 200 to 300 ml / g. Within this range, the viscosity of the coating agent does not become too high, and the leveling properties are good. The oil absorption is measured in accordance with JIS K5101-13-1.

[0051] Specific examples of silica fine particles include Sylysia 370, 380, 440, and 450 (manufactured by Fuji Silysia Chemical Ltd.), ACEMATT790 (manufactured by Evonik Japan Ltd.), SYLOIDRAD2105, SYLOID C907, and SYLOIDMX307 (manufactured by WR GRACE & Co.).

[0052] The preferred range of the content of silica fine particles is the same as the content of the above-mentioned fine particles. When the content is 10% by mass or more, the durability and matte property of the surface protective layer are improved, and when the content is 40% by mass or less, the leveling property and transparency of the coating film are improved.

[0053] (Other additives) If necessary, other additives may be added to the present invention as long as they do not impair the effects of the present invention. Examples of other additives include dispersants, antifoaming agents, leveling agents, release agents (tape release agents), scratch-resistant agents, polymerization inhibitors, ultraviolet absorbers, light stabilizers, antioxidants, sensitizers, antibacterial and antifungal agents, etc. It is preferable to include a dispersant, an antifoaming agent, and a leveling agent.

[0054] (dispersant) In the present invention, it is preferable to use a dispersant. By using a dispersant, it is possible to suppress the increase in viscosity of the coating agent that occurs with the addition of fine particles. There are no particular limitations on the dispersant, and known dispersants can be used. Furthermore, when silica fine particles are used, it is preferable that the dispersant has an amine value. Furthermore, it may also have a carboxyl group. The amount of dispersant added is preferably 0.1 to 10 mass% of the total mass of the coating agent, and more preferably 0.5 to 7 mass%. If it is less than 0.1 mass%, the effect of suppressing the increase in viscosity is low, and if it is 10 mass% or more, the degree of crosslinking of the coating film decreases, and the physical properties of the coating film deteriorate. Furthermore, when silica fine particles are used as the fine particles, the amount of dispersant added is preferably 3 to 12 mass% of the total mass of the silica fine particles, and more preferably 5 to 10 mass%.

[0055] (Antifoaming agent) In the present invention, it is preferable to use an antifoaming agent. The compound constituting the antifoaming agent is not particularly limited, and known compounds can be used. Examples include acrylic resins, vinyl ether resins, butadiene resins, silicone resins, fluorine-based resins, and modified resins thereof, with silicone resins being preferred. The amount of antifoaming agent added is preferably 0.05 to 3 mass % of the total mass of the coating agent, and more preferably 0.1 to 2 mass %.

[0056] (Leveling agent) In the present invention, it is preferable to use a leveling agent. The leveling agent is not particularly limited, and any known agent can be used as long as it provides the desired leveling effect, i.e., the effect of suppressing coating defects such as cissing and pinholes during coating and the effect of smoothing the surface of the layer to be formed. Examples of the leveling agent include silicone-based leveling agents, fluorine-based leveling agents, acrylic-based leveling agents, siloxane-modified acrylic-based leveling agents, and vinyl-based leveling agents. The amount of the leveling agent added is preferably 0.05 to 3 mass % of the total mass of the coating agent, and more preferably 0.1 to 2 mass %.

[0057] (solvent) The active energy ray-curable coating agent of the present invention preferably contains no solvent or contains no more than 5% by mass of the total mass of the coating agent, more preferably no more than 3% by mass, even more preferably no more than 1.5% by mass, even more preferably no more than 1% by mass, and particularly preferably no more than 0.5% by mass. Being solvent-free or containing a solvent within the above range improves surface properties such as abrasion resistance. Furthermore, not only does it eliminate the need for a drying process, but it also reduces energy costs associated with printing.

[0058] (Viscosity of active energy ray curable coating agent) The viscosity of the active energy ray-curable coating agent of the present invention, measured using a Brookfield viscometer at 25°C, 6 rpm, and rotor No. 3, is preferably 200 to 2000 mPa·s, more preferably 250 to 1500 mPa·s, and even more preferably 300 to 1000 mPa·s. By staying within the above range, excessive penetration into the substrate is suppressed when applying the coating by printing or other methods, thereby achieving a uniform matte finish. Viscosity can be adjusted by adjusting the blending ratio of the (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms, the mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms and optionally containing a heteroatom, and the (meth)acrylate (B) having 3 or more functional groups, adjusting the amount of fine particles, or adjusting the amount of dispersant. Examples of viscosity adjustment methods are shown below. For example, 15 to 30 mass% of alkylene glycol diacrylate having 4 carbon atoms is used as (A1), 50 to 60 mass% of trifunctional acrylate is used as (B), 18 to 25 mass% of silica fine particles as fine particles, and 0.5 to 1 mass% of a dispersant are used.

[0059] (Production of active energy ray curable coating agents) In one embodiment, for example, the active energy ray-curable coating agent can be produced by blending 10 to 30 parts by mass of a (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms and / or a mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom, 50 to 60 parts by mass of a (meth)acrylate (B) having 3 or more functional groups, 10 to 30 parts by mass of fine particles, and, as appropriate, 0.2 to 2 parts by mass of a dispersant or antifoaming agent, and stirring and mixing the mixture using a bladed mixer (disper) or the like for about 30 minutes to 3 hours.

[0060] If the active energy ray-curable coating agent of the present invention contains unexpected coarse particles or the like, these particles will deteriorate the quality, so it is preferable to remove them by filtration, etc. Conventional known filters can be used.

[0061] (base material) The substrate used in the present invention is not particularly limited as long as it can be used for a decorative material, and examples thereof include paper substrates such as tissue paper, reinforced paper, kraft paper, fine paper, linter paper, baryta paper, parchment paper, and Japanese paper, and film substrates such as olefin resins such as polypropylene, polyethylene terephthalate, and triacetyl acetate. Paper substrates are preferred.

[0062] (Paper base material) The paper base material has a basis weight of 20 g / m 2 ~150g / m 2 It is preferable that the density is 30 to 100 g / m 2 The thickness of the paper substrate is preferably 20 μm to 200 μm, and the paper substrate is preferably thin paper.

[0063] (decorative materials) The decorative material of the present invention has a substrate, a colored layer, and a surface protective layer in this order. The colored layer is formed on the substrate, and then an active energy ray-curable coating agent is printed or applied to form a layer, and then the layer is cured by irradiating with active energy rays to form the surface protective layer. There are no particular limitations on the printing or coating method, and known methods can be used. Examples of printing machines include roll coaters, gravure coaters, flexo coaters, air doctor coaters, blade coaters, air knife coaters, squeeze coaters, impregnation coaters, transfer roll coaters, kiss coaters, curtain coaters, cast coaters, die coaters, offset printing, gravure / offset printing, gravure printing, flexo printing, and screen printing. Of these, gravure / offset printing and gravure printing are preferred.

[0064] The active energy rays that can be used include far ultraviolet rays, ultraviolet rays, near ultraviolet rays, electron beams (EB), and proton rays. Of these, electron beams (EB) and proton rays are preferred because they can cure without using a photopolymerization initiator.

[0065] When curing with electron beams, a conventionally known curing device can be used, and the exposure dose is preferably 10 kGy to 200 kGy, more preferably 30 kGy to 100 kGy. An exposure dose of 10 kGy or more prevents poor curing, while an exposure dose of 200 kGy or less minimizes the impact on the substrate. The acceleration voltage is set depending on the thickness and density of the coating film, and is preferably 50 kV to 250 kV, more preferably 75 to 125 kV.

[0066] (gloss value) The 60° gloss value of the surface protective layer is preferably 35 or less, more preferably 30 or less, and even more preferably 25 or less. The 60° gloss value is determined by applying an active energy ray curable coating agent to the colored layer with a bar coater #4 in an amount of 8 g / m 2 The 60° gloss value of the cured surface protective layer was measured using a Micro-TRI-gloss meter manufactured by BYK-Gardner. The gloss value was measured in accordance with JIS Z 8741:1997, 60° specular gloss (Gs(60°)). In order to make the 60° gloss value of the surface protective layer 35 or less, the content of fine particles in the surface protective layer is preferably 10 to 40 mass%, more preferably 15 to 38 mass%, and even more preferably 18 to 35 mass%.

[0067] (colored layer) The colored layer is a layer that imparts a desired hue to the surface of the substrate, and may be a patterned layer or a solid layer. It is also possible to laminate a plurality of different colored layers. The colored layer may have a single color or a pattern (design) composed of multiple colors. The colored layer can be formed by coating or printing with ink. For example, the ink may contain a binder resin and a colorant such as a pigment.

[0068] (Transparent resin layer) The decorative material of the present invention can have a transparent resin layer between the colored layer and the surface protective layer. The transparent resin layer can be formed by coating, printing, or the like using a varnish containing a binder resin. The transparent resin layer improves adhesion between the colored layer and the surface protective layer, improving durability such as abrasion resistance.

[0069] Preferred examples of the binder resin used in the colored layer and / or transparent resin layer include urethane resin, acrylic polyol resin, acrylic resin, ester resin, amide resin, butyral resin, styrene resin, urethane-acrylic copolymer, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-acrylic copolymer resin, chlorinated propylene resin, nitrocellulose resin (nitrocellulose), and cellulose acetate resin, which can be used alone or in combination of two or more. Furthermore, the binder resin may be a resin obtained by adding a curing agent such as an isocyanate-based curing agent or an epoxy-based curing agent to the resin and crosslinking and curing it.

[0070] The colored layer and / or transparent resin layer can be provided on the substrate by a known method, specifically, comma coating, gravure coating, reverse coating, roll coating, lip coating, spray coating, silk screen printing, offset printing, gravure printing, etc. Among these, gravure printing is preferred.

[0071] (Manufacturing of cosmetic materials) The method for producing a decorative material is not particularly limited, as long as a surface protective layer using the active energy ray-curable coating agent of the present invention is formed on a substrate. Alternatively, a decorative material may be produced by forming a colored layer made of a printing ink composition on the substrate, and then printing, applying, and curing the active energy ray-curable coating agent of the present invention on the colored layer. A primer layer may also be formed between the colored layer and the surface protective layer. The colored layer enhances the matte properties of the decorative material, while the primer layer is expected to improve adhesion between the active energy ray-curable coating agent and the colored layer and relieve stress during curing by active energy rays. The colored layer may also function as a primer layer. Furthermore, by laminating the substrate side to a wood substrate such as particle board or plywood, a decorative board for use in furniture, etc. can be produced.

[0072] Specific examples of the composition of the decorative material are shown below. Base material / colored layer / surface protection layer Base material / colored layer / transparent resin layer / surface protection layer

[0073] (Example) The present invention will be described in more detail below with reference to examples and comparative examples, but the following examples are not intended to limit the technical scope of the present invention in any way. In the examples, "parts" means "parts by mass" and "%" means "% by mass." The blend amounts in the table are in parts by mass, and blank spaces in the table indicate that no blend was used. It should be noted that Example 20 is a reference example.

[0074] Details of the various measurements carried out in the following examples are as follows.

[0075] (viscosity) The viscosity was measured using a Brookfield viscometer with a rotor No. 3 at 6 rpm in a 25°C environment.

[0076] (Average particle size) The average particle size is the D50 value in the particle size distribution determined by the light scattering method, and was measured using a Microtrack Bell T330EXII.

[0077] Example 1 22 parts by mass of 1,4-butanediol diacrylate, 55.8 parts by mass of trimethylolpropane ethylene oxide modified triacrylate, 20 parts by mass of silica fine particles A (Sylysia 450, manufactured by Fuji Silysia Chemical Ltd.), 1.5 parts by mass of dispersant, 0.5 parts by mass of leveling agent, and 0.2 parts by mass of antifoaming agent were added to a mixer equipped with stirring blades, and the mixture was stirred and mixed for 50 minutes to obtain active energy ray curable coating agent S1.

[0078] (Examples 2 to 23, Comparative Examples 1 to 4) Using the formulations shown in Tables 1 and 2, active energy ray-curable coating agents S2 to 23 and T1 to 4 were obtained in the same manner as in Example 1.

[0079] Base material: 30g / m 2 A printed matter with a colored layer was obtained by gravure printing water-based ink (50 parts of acrylic emulsion (manufactured by Toyo Ink Co., Ltd., solid content 25%, acid value 150 mgKOH / g), 5 parts of titanium oxide, 44 parts of water) on tissue paper. The active energy ray curable coating agents S2 to 23 and T1 to 4 obtained in the examples and comparative examples were applied to the colored layer of the printed matter using a bar coater #4 in an amount of 8 g / m 2 The coating was then irradiated with electron beams under the following conditions to form a surface protective layer, thereby obtaining a decorative material. Electron beam irradiation conditions: 125kV-30kGy-20m / min.

[0080] The raw materials used in the examples and comparative examples are as follows. (Poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms) 1,4-butanediol diacrylate (carbon number 4) 1,6-Hexanediol diacrylate (carbon number 6) 1,6-Hexanediol ethylene oxide (EO) modified diacrylate (carbon number 6, EO addition mole number (a + b) approximately 2) 1,10-decanediol diacrylate (carbon number 10, containing 60% by mass of biomass-derived structural units) (Mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom) Dodecyl acrylate (carbon number 12, contains 80% by mass of biomass-derived structural units) Octadecyl methacrylate (carbon number 18, containing 80% by mass of biomass-derived structural units) Tetrahydrofuryl acrylate (carbon number 5, containing 75% by mass of biomass-derived structural units) Isobornyl acrylate (carbon number 10, containing biomass-derived structural units) ((Meth)acrylate (B) with 3 or more functional groups) Trimethylolpropane ethylene oxide (EO) modified triacrylate (functional groups: 3, EO added moles: approximately 3) Glycerin propoxytriacrylate (functional group number 3, contains 14% by mass of biomass-derived structural units) Dipentaerythritol hexaacrylate (functional group number 6) (fine particles) ·Silica fine particles A: average particle size 8μm, oil absorption 220mL / 100g Silica microparticle B: average particle diameter 7.5 μm, oil absorption 300 mL / 100 g, organically treated silica Silica microparticle C: average particle size 5.5 μm, oil absorption 120 mL / 100 g, organically treated silica Acrylic resin beads: average particle size 6 μm Dispersant: Polyester resin Leveling agent: acrylic resin Antifoaming agent: silicone resin

[0081] The decorative materials S1 to 23 and T1 to 4, which were made using the active energy ray-curable coating agents S1 to 23 and T1 to 4 obtained in the Examples and Comparative Examples, were evaluated for leveling ability, abrasion resistance, and matte property by the following methods. The evaluation results are shown in Tables 1 and 2.

[0082] <Leveling ability> The uniformity of the density on the surface protective layer (presence or absence of unevenness and / or pinholes) was evaluated visually. "Unevenness" refers to a state in which the coating film is not formed smoothly during the process from coating to curing, resulting in minute variations in gloss on the surface. "Pinholes" refers to a state in which the coating film is not formed smoothly during the process from coating to curing, resulting in minute dot-like chips on the surface. (Evaluation criteria) A: No uneven printing or pinholes B: Slightly uneven printing, no pinholes C: There are slight printing irregularities and pinholes D: There are obvious printing irregularities and pinholes The practical level is A, B or C.

[0083] <Wear resistance> For abrasion resistance, an adhesive (Cevian A, manufactured by Daicel Chemical Industries, Ltd.) was applied to the entire substrate surface of decorative materials S1 to 23 and T1 to 4, and then the materials were attached to plywood (particle board, manufactured by Takehara Kogyo Co., Ltd.) and laminated with a mirror-finished press plate before evaluation. The surface of the decorative material was subjected to an abrasion test 200 times using a Taber abrasion tester (abrasion wheel CS-17), and the degree to which the colored layer was removed was evaluated visually. (Evaluation criteria) A: More than 90% of the colored layer remains B: 70% or more but less than 90% of the colored layer remains C: 50% or more but less than 70% of the base colored layer remains D: Less than 50% of the colored layer remains The practical level is A, B or C.

[0084] <Matte finish> The 60° gloss value of the surface protective layer was measured five times using a gloss meter (BYK-Gardner "micro-TRI-gloss μ"), and the average value was evaluated as follows. A: 20 or less B: More than 20 and less than 30 C: Over 30 but below 35 D: Over 35 The practical level is A, B or C.

[0085] [Table 1]

[0086] [Table 2]

[0087] As shown in Tables 1 and 2, Examples 1 to 23 were excellent in leveling property, abrasion resistance, and matting property. Comparative Example 1, which used an alkylene glycol di(meth)acrylate having an alkylene group with less than 4 carbon atoms, was inferior in abrasion resistance. Comparative Example 2, which did not contain (A1) and (A2), was inferior in matting property. Comparative Example 3, which did not contain (B), was inferior in abrasion resistance and matting property. Comparative Example 4, which did not contain fine particles, was inferior in leveling property and matting property.

Claims

1. An active energy ray-curable coating agent used to form a surface protective layer of a decorative material having a substrate, a colored layer, and a surface protective layer, The composition comprises a (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms and / or a mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom, a (meth)acrylate (B) having 3 or more functional groups, and fine particles, the active energy ray-curable coating agent, wherein the total content of the (poly)alkylene glycol di(meth)acrylate (A1) in which the alkylene group has 4 or more carbon atoms, the mono(meth)acrylate (A2) having a hydrocarbon group which may contain a heteroatom and has 4 or more carbon atoms, and the (meth)acrylate (B) having 3 or more functional groups is 60 mass% or more, based on the total mass of the active energy ray-curable coating agent.

2. 2. The active energy ray-curable coating agent according to claim 1, wherein the viscosity of the active energy ray-curable coating agent is 200 to 2000 mPa s as measured at 25°C, 6 rpm, and rotor No. 3 using a Brookfield viscometer.

3. 3. The active energy ray-curable coating agent according to claim 1, wherein the mass ratio ((A1)+(A2):(B)) of the total amount of the (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms and the mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom to the (meth)acrylate (B) having 3 or more functional groups is 5:95 to 50:

50.

4. 3. The active energy ray-curable coating agent according to claim 1, wherein at least one selected from the group consisting of a (poly)alkylene glycol di(meth)acrylate (A1) having an alkylene group with 4 or more carbon atoms, a mono(meth)acrylate (A2) having a hydrocarbon group with 4 or more carbon atoms which may contain a heteroatom, and a (meth)acrylate (B) having 3 or more functional groups comprises a structural unit derived from biomass.

5. 3. The active energy ray-curable coating agent according to claim 1, wherein the fine particles are silica fine particles.

6. 6. The active energy ray-curable coating agent according to claim 5, wherein the content of the silica fine particles in the total mass of the active energy ray-curable coating agent is 10 to 40 mass %.

7. A decorative material comprising a substrate, a colored layer, and a surface protective layer formed from the active energy ray-curable coating agent according to claim 1 or 2.

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