JP2008018579A - Decorative sheet and decorative panel using the sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively with good productivity provide a decorative sheet which has a feeling of unevenness and depth recognized as a recess visually as a design and is excellent in tolerability during use such as contamination resistance, weatherable adhesion or abrasion resistance. <P>SOLUTION: In the decorative sheet, after a pattern-shaped low gloss printing layer is formed on one side of a transparent synthetic resin substrate layer, and a pattern printing layer is formed on the other side of the transparent synthetic resin substrate layer. The pattern-shaped low gloss printing layer is formed by a printing ink comprising a vehicle in which a urethane resin prepared by reacting a polyol component and an isocyanate component is at least kneaded. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a decorative sheet having a visual unevenness and excellent deep design, and a decorative board using the decorative sheet.

  Conventionally, as a surface decoration material for furniture, cabinets, tables, desks, etc., on the surface of a decorative board substrate such as a wooden substrate, an inorganic substrate, a synthetic resin substrate, a metal substrate, for example, A decorative sheet is used in which a decorative sheet printed with a wood grain pattern or the like is attached with an adhesive. The decorative sheet used for such a decorative board is required to have flexibility, machinability and the like as post-processing suitability, and weather resistance, heat resistance, water resistance, stain resistance, and scratch resistance as suitability for use. Various aptitudes such as wear resistance are required and are configured to satisfy these aptitudes.

  In addition, due to consumer demand for luxury goods in recent years, furniture, cabinets, tables, desks, etc. have been required to have a high-class feeling, and there is a demand for an appearance that gives a high-class feeling. Various proposals have been made.

  For example, an area having different wettability with respect to an electron beam curable paint or light curable paint is formed by an application surface provided in a pattern on a substrate, and then an electron beam curable paint or light is formed. A decorative sheet has been proposed in which a curable paint is applied, the surface of the paint is depressed in an area that is easily wetted with the paint, and the surface of the paint is raised in an area that is difficult to wet (for example, patent documents) 1). However, this decorative sheet is easily wetted, i.e., when the concave portion is fine, the concave portion cannot be expressed and the boundary between the concave portion and the convex portion is rounded by the surface tension of the paint. There is a problem that sharp unevenness cannot be obtained.

  Moreover, if another one is illustrated, two types of pattern layers, a pattern layer made of normal ink and a convex pattern layer made of an electron beam curable composition, are sequentially provided on the base material, A cosmetic material has been proposed in which a transparent resin layer is coated, and after the coating, an electron beam is irradiated through the transparent resin layer to cure the convex pattern to express a sense of unevenness (for example, see Patent Document 2). However, since this decorative material has relatively large irregularities physically, there is a problem that the convex portion is easily damaged, and particularly when the area of the convex portion is large, it becomes prominent. Furthermore, this decorative material is, for example, when it is desired to express the strength of luster such as a wood grain pattern, that is, when a concave portion with a very narrow width is present, as in the case of a wood grain conduit groove. There is a problem that the desired design cannot be stably obtained because the concave portion is filled by the flow of the coating material constituting the transparent resin layer, and the degree of filling varies.

  As another example, after applying a synthetic resin that performs radiation polymerization to a substrate with printed paper or decorative paper, irradiation is stopped when the synthetic resin is in a semi-cured state. Then, after pressing with a cold press body such as a roll press having a concavo-convex pattern, a decorative board is proposed that expresses the concavo-convex feeling by completely curing the synthetic resin (see, for example, Patent Document 3). . However, in this decorative board, it is not easy to specify the curing conditions when the resin is stably made into a certain semi-cured state, and the synthetic resin in the semi-cured state is unstable and the curing is performed in two stages. There is a problem that it is cumbersome to carry out separately.

  As another example, an electron beam curable resin is applied on a base material using a coating apparatus, and contacted with a mold roll in an electron beam irradiator to mold the unevenness of the mold roll. However, there has been proposed a cosmetic material that expresses a feeling of unevenness by irradiating and curing an electron beam (for example, see Patent Document 4). However, this decorative material requires a special mold roll device, the problem that it is not possible to mold the unevenness with a normal printing device, the problem is that the molding speed by the mold roll is limited, and the productivity is low There is.

As another example, the surface of the substrate has a coating layer, a pattern layer, and a surface protective layer obtained by crosslinking and curing the ionizing radiation curable resin composition, and the pattern layer is compared with the coating layer. And the cosmetics which comprised highly the permeability of the ionizing radiation-curable resin composition are proposed (for example, refer patent document 5). Since this ionizing radiation curable resin composition is more easily penetrated into the part where the pattern exists, this decorative material is formed with a concave portion in the part, and a cosmetic material expressing a feeling of unevenness on the surface is obtained. If a large amount of extender pigment or porous material is added to give sufficient absorption permeability to the pattern layer, the recesses become porous or brittle, which decreases the durability and stain resistance of the recesses. In order to improve the durability and contamination resistance of the recesses, there is a problem that the recesses having sufficient depth and sharpness cannot be formed if the pattern layer is made porous.
Japanese Patent Publication No. 51-26937 Japanese Patent Publication No. 01-41505 Japanese Patent Publication No.49-28264 Japanese Examined Patent Publication No. 63-50066 JP 2001-199028 A

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to have both a concavo-convex sensation visually recognized as a concavity and a depth (depth) as a design, as well as contamination resistance and weather resistance adhesion. It is to provide a decorative sheet excellent in durability at the time of use, such as property and wear resistance, at low cost with good productivity, and to provide a decorative board using the decorative sheet.

  In order to achieve the above-mentioned object, the present inventor described in claim 1 provides a pattern-like low-gloss printing layer on one surface of a synthetic resin transparent substrate layer, and then the entire surface of the one surface. A decorative sheet provided with a surface protective layer and provided with a pattern printing layer on the other surface side of the synthetic resin transparent base material layer, wherein the patterned low gloss printing layer reacts a polyol component and an isocyanate component. The urethane resin is formed of a printing ink made of at least a kneaded vehicle.

  The present invention according to claim 2 is the decorative sheet according to claim 1, wherein the printing ink is obtained by adding fine particles.

  In the decorative sheet according to claim 1, a synthetic resin colored layer is provided on the other surface side of the synthetic resin transparent base material layer so as to sandwich the pattern printing layer. It is characterized by that.

  According to a fourth aspect of the present invention, in the decorative sheet according to the first aspect, a concave pattern is provided on the surface protective layer side.

  Further, according to a fifth aspect of the present invention, in the decorative sheet according to the first aspect, the surface protective layer is made of a curable resin.

  The present invention according to claim 6 is the decorative sheet according to claim 5, wherein the curable resin is an ionizing radiation curable resin.

  The decorative board of the present invention according to claim 7 is characterized in that the decorative sheet according to any one of claims 1 to 6 is stuck to a base material for decorative board via an adhesive layer. is there.

  The decorative sheet of the present invention and the decorative board using the decorative sheet of the present invention are not only excellent in resistance at the time of use such as stain resistance, weather resistance adhesion, wear resistance, etc. And an excellent design effect in depth (depth).

  FIG. 2 is a layer configuration diagram schematically illustrating the basic configuration of the decorative sheet according to the present invention, and FIG. 2 is a layer configuration diagram schematically illustrating an embodiment of the decorative sheet according to the present invention. 'Is a decorative sheet, 2 is a transparent base layer made of synthetic resin, 2' is a colored layer made of synthetic resin, 3, 3 'is a primer layer, 4 is a patterned low gloss printing layer, 5 is a surface protective layer, 6 is a pattern Print layer, 7 is a concave pattern, 8 is an adhesive layer, 61 is a pattern print layer, and 62 is a solid print layer.

  FIG. 1 is a layer configuration diagram schematically showing a basic configuration of a decorative sheet according to the present invention. The decorative sheet 1 is provided with a primer layer 3 on one entire surface of a synthetic resin transparent base material layer 2, and the primer A patterned low-gloss printing layer 4 is provided on the layer 3, a surface protective layer 5 is provided on the entire surface of the one surface on the patterned low-gloss printing layer 4, and the other transparent base layer 2 made of synthetic resin is provided. A pattern printing layer 6 is provided on the surface side, and embossing is applied from the surface protective layer 5 side to form a concave pattern 7. In FIG. 1, the pattern printing layer 6 is shown in contact with the synthetic resin transparent substrate layer 2, but the pattern printing layer 6 is the other side of the synthetic resin transparent substrate layer 2. It is only necessary that the pattern print layer 6 is configured to be visible from the surface protective layer 5 side through the synthetic resin transparent base material layer 2 and the surface protective layer 5 side. The pattern print layer 6 is generally composed of a pattern print layer 61 and a solid pattern print layer 62 from the synthetic resin transparent substrate layer 2 side. Moreover, although the embodiment which provided the said concave pattern 7 was shown in FIG. 1, the said concave pattern 7 should just be provided as needed, and is not essential.

  FIG. 2 is a layer configuration diagram schematically showing one embodiment of a decorative sheet according to the present invention, wherein the decorative sheet 1 ′ is provided with a primer layer 3 ′ on at least one surface of the synthetic resin colored layer 2 ′. On the primer layer 3 ′, there is provided a pattern printing layer 6 in which a solid pattern printing layer 62 and a pattern printing layer 61 are printed in order, and two liquids comprising a polyol component and an isocyanate component are formed on the entire surface on the pattern printing layer 6 side. A synthetic resin transparent base material layer 2 is provided via an adhesive layer 8 formed of a curable polyurethane adhesive, and a primer layer 3 is provided on the entire surface of the synthetic resin transparent base material layer 2. A patterned low-gloss printing layer 4 is provided on the surface, and a surface protective layer 5 is provided on the entire surface of the synthetic resin transparent base material layer 2 on the patterned low-gloss printing layer 4, and embossed from the surface protective layer 5 side. Processed to form concave pattern 7 Those were. The recessed pattern 7 may be provided as necessary and is not essential.

  Next, various materials constituting the decorative sheet 1, 1 'will be described. First, as the resin constituting the synthetic resin transparent substrate layer 2 and the synthetic resin colored layer 2 ′, it is excellent in processability and does not generate harmful gas during combustion. (Including linear low density polyethylene), medium density polyethylene, high density polyethylene, ethylene alpha olefin copolymer, homopolypropylene, polymethylpentene, polybutene, ethylene-propylene copolymer, propylene-butene copolymer, ethylene-acetic acid Olefin-based thermoplastic resins such as vinyl copolymer, ethylene-vinyl alcohol copolymer, or mixtures thereof, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene naphthalate-isophthalate copolymer, polycarbonate, polyary Thermoplastic ester resins such as polyester, acrylic thermoplastic resins such as polymethyl methacrylate, polyethyl methacrylate, polyethyl acrylate, and polybutyl acrylate; polyamide-based heat such as nylon-6 and nylon-66 Non-halogen thermoplastic resins such as a plastic resin, polyimide, polyurethane, polystyrene, acrylonitrile-butadiene-styrene resin, and the like can be given. These thermoplastic resins may be used singly or as a mixture of two or more. However, since the design print layer 6 and the recessed pattern 7 are provided as a design, their suitability is required. In view of the fact that no harmful gas is generated at the time of combustion, which has become a problem in recent years, or cost is considered comprehensively, an olefin-based thermoplastic resin is preferable. The synthetic resin transparent substrate layer 2 may be translucent, colored transparent or translucent, and the synthetic resin colored layer 2 ′ may be colored. It may be transparent, translucent or opaque (having concealment), or may be an uncolored uncolored layer.

  Further, the synthetic resin-made transparent base material layer 2 and the synthetic resin-made colored layer 2 ′ may be in an unstretched state or in a state of being stretched in a uniaxial or biaxial direction. Two or more layers may be laminated, and various configurations can be taken as appropriate, but the thickness is generally about 30 to 300 μm. In addition, these layers 2 and 2 'may be subjected to a known easy adhesion treatment such as corona discharge treatment, plasma treatment, ozone treatment, etc. on a necessary surface as necessary. In addition, these layers 2 and 2 'may be appropriately added with known additives such as an antioxidant, a light stabilizer, and an ultraviolet ray inhibitor.

  The picture print layer 6 can be formed using ink by a known printing method such as a gravure printing method, an offset printing method, a silk screen printing method, or the like. Examples of the pattern print layer 61 include a wood grain pattern, a stone pattern, a cloth pattern, a skin pattern, a geometric pattern, characters, symbols, line drawings, and various abstract pattern patterns. Solid-printed with colored ink having concealability. 1 and 2, the pattern printing layer 6 is provided with both the pattern printing layer 61 and the solid pattern printing layer 62, but either one of the structures is provided. Is also good.

  Examples of the ink for forming the pattern printing layer 6 include chlorinated polyolefins such as chlorinated polyethylene and chlorinated polypropylene as a vehicle, polyester, polyurethane composed of isocyanate and polyol, polyacryl, polyvinyl acetate, polyvinyl chloride, and vinyl chloride. -A mixture of one or more vinyl acetate copolymers, cellulose resins, polyamide resins, etc. can be used, and inks can be used by adding pigments, solvents, various auxiliary agents, etc. In consideration of the problem, a non-chlorine vehicle in which one or two or more types such as polyester, polyurethane composed of isocyanate and polyol, polyacryl, polyvinyl acetate, cellulose resin, and polyamide resin are mixed is suitable, and more preferable. Is polyester, isocyanate and polio Polyurethane consisting Le, polyacrylic, to one without such a polyamide resin is a mixture of two or more.

  Next, the patterned low gloss print layer 4 will be described. The patterned low-gloss printing layer 4 is a region (low-gloss region) where the region provided with this layer is less glossy than the other regions. Although this mechanism has not yet been fully elucidated, when the uncured material of the surface-protective layer 5 made of the curable resin provided on the surface and the patterned low-gloss printed layer 4 is applied, It is presumed that the resin component of the patterned low-gloss printing layer 4 and the uncured product of the surface protective layer 5 exhibit some interactions such as elution, dispersion, and mixing depending on the combination of materials and application conditions. Is done. That is, the respective resin components in the uncured product of the curable resin that forms the patterned low-gloss printing layer 4 and the surface protective layer 5 are suspended without being completely compatible in a short time. It is considered that the portion present on or near the patterned low-gloss print layer 4 and in the suspended state scatters light to form a low-gloss region. Since the surface protective layer 5 is formed by crosslinking and curing while maintaining this suspended state, the region on the patterned low-gloss printing layer 4 in the surface protective layer 5 is at least a low-gloss region. By the illusion of, it is assumed that the area is recognized as if it were a recess. Further, depending on the type and application conditions of the ink for forming the patterned low gloss printing layer 4 and the curable resin composition for forming the surface protective layer 5, the outermost surface of the surface protective layer 5 may be In some cases, the glossy printed layer 4 is raised to form a convex shape. Since the surface of the surface protective layer 5 has such a convex shape, light is also scattered at this portion, which is preferable because the visual unevenness is further emphasized. In addition, about the height of the said convex shape, it is preferable that it is the height which is the range which has the effect of this invention, and is usually the range of 2-3 micrometers.

  The ink that forms the patterned low-gloss printing layer 4 has a property of causing interaction with the curable resin composition (uncured curable resin) that forms the surface protective layer 5, and is curable. It is appropriately selected in relation to the resin composition (uncured curable resin). Specifically, the ink vehicle preferably contains (kneads) at least a urethane resin. The urethane resin is a polyol component such as an acrylic polyol, a polyester polyol or a polyether polyol, and an isocyanate component such as tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate or other aromatic isocyanate, isophorone diisocyanate, hexamethylene diisocyanate, hydrogenated. For example, a urethane resin obtained by reacting an isocyanate such as an aliphatic or alicyclic isocyanate such as tolylene diisocyanate (which may be linearly crosslinked or network crosslinked) may be mentioned. it can. Although it is preferable to use a urethane resin having a urethane bond as the ink vehicle, the pattern-like low gloss is obtained by using a so-called two-component curable printing ink comprising a vehicle in which an isocyanate component is blended with a polyol component. The pattern-like low gloss printing layer 4 made of a urethane resin obtained by printing and printing the printing layer 4 may be used.

  If necessary, unsaturated polyester resin, acrylic resin, vinyl chloride-vinyl acetate copolymer may be used to adjust the degree of expression of the low gloss region and the contrast of the gloss difference between the low gloss region and its surroundings. A gloss adjusting resin such as the above may be used in combination. The mixing ratio of the gloss adjusting resin is in the range of 10 to 90% by weight with respect to the total amount of the vehicle. If it is within this range, a sufficient enhancement effect of low gloss area expression can be obtained. The ink for forming the patterned low gloss printing layer 4 may be uncolored or may be colored by adding a colorant such as a pigment.

  In the present invention, the surface protective layer 5 is provided on the patterned low-gloss printing layer 4, and the curable resin composition (the ink constituting the patterned low-gloss printing layer 4 and the surface protective layer 5 ( The region on the patterned low-gloss printing layer 4 becomes at least a low-gloss region by the interaction with the uncured product of the curable resin, and the region is recognized as if it is a concave portion by the optical illusion. Is. The film thickness of the patterned low gloss printing layer 4 is suitably 0.5 μm or more and 5.0 μm or less in consideration of printability and interaction with the curable resin composition (uncured curable resin). is there.

  Further, it is preferable to incorporate extender pigments as fine particles in the printing ink for forming the patterned low gloss printing layer 4. By blending the extender, light scattering can be promoted and the low gloss effect can be further enhanced. The extender pigment is not particularly limited, and is suitably selected from, for example, silica, talc, clay, barium sulfate, barium carbonate, calcium sulfate, calcium carbonate, magnesium carbonate and the like. Among these, silica, which is a material having a high degree of freedom in material design such as oil absorption, particle size, pore volume, etc., and excellent in designability, whiteness, and coating stability as an ink, is preferable. Silica is preferred.

  The average particle diameter of silica may be determined in relation to the film thickness (μm) of the patterned low gloss printing layer 4 and is generally 1.0 μm or more, and the maximum particle diameter is the surface The thickness of the protective layer 5 should be determined in relation to the film thickness (μm), but the film thickness of the surface protective layer 5 takes into consideration various physical properties required for a decorative sheet (post-processing suitability and proper use) and cost. It is generally 10.0 μm or less, preferably 7.0 μm or less, and the optimum range of the average particle diameter is 2.0 μm or more and 5.0 μm or less. The amount of the extender pigment added to the ink for forming the patterned low gloss print layer 4 is suitably 5 to 15 parts by weight with respect to 100 parts by weight of the ink composition other than the extender pigment. If the amount is less than 5 parts by weight, sufficient thixotropy cannot be imparted to the printing ink composition forming the patterned low-gloss printing layer 4, and if it exceeds 15 parts by weight, the effect of imparting low gloss is reduced. Therefore, it is not preferable.

  Next, the surface protective layer 5 will be described. This surface protective layer 5 is provided for imparting surface physical properties such as scratch resistance, abrasion resistance, stain resistance, water resistance, and weather resistance required for the decorative sheet 1, 1 ′ (see FIGS. 1 and 2). As the resin for forming the surface protective layer 5, it is appropriate to use a curable resin such as a thermosetting resin or an ionizing radiation curable resin. It is an ionizing radiation curable resin because it is hard and has excellent productivity.

As thermosetting resins, unsaturated polyester resins, polyurethane resins (including two-component curable polyurethane), epoxy resins, amino alkyd resins, phenol resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, melamine-ureas Examples thereof include a cocondensation resin, a silicon resin, and a polysiloxane resin. If necessary, a curing agent such as a crosslinking agent or a polymerization initiator, or a polymerization accelerator is added to the resin. For example, as a curing agent, isocyanate or organic sulfonate is added to unsaturated polyester resin or polyurethane resin, organic amine is added to epoxy resin, peroxide such as methyl ethyl ketone peroxide, azoisobutyl nitrile, etc. The radical initiator is added to the unsaturated polyester resin. As a method of forming the surface protective layer with the thermosetting resin, for example, the above thermosetting resin is made into a solution, applied by a known coating method such as a roll coating method or a gravure coating method, dried and cured. Can be formed. The coating amount of the surface protective layer is suitably about 1 to ²⁰ g / m ^{2 in} terms of solid content, and in particular, the film thickness of the patterned low gloss printing layer is 0.5 μm or more and 5.0 μm or less, When the average particle size is 1.0 μm or more and 7.0 μm or less, ² to 10 g / m ² in terms of solid content is appropriate.

  Next, the ionizing radiation curable resin will be described. The ionizing radiation curable resin is a resin that undergoes a cross-linking polymerization reaction upon irradiation with ionizing radiation and changes to a three-dimensional polymer structure. The ionizing radiation means an electromagnetic wave or charged particle beam having an energy quantum capable of polymerizing and cross-linking molecules, such as visible light, ultraviolet light (near ultraviolet light, vacuum ultraviolet light, etc.), X-ray, electron beam, ion beam, etc. is there. Usually, ultraviolet rays or electron beams are used. As the ultraviolet ray source, a light source such as an ultra high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light fluorescent lamp, or a metal halide lamp can be used. As an ultraviolet wavelength, a wavelength range of 190 to 380 nm can be used. As the electron beam source, various electron beam accelerators such as a cockcroft-wald type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type can be used. The electron beam used is 100 to 1000 keV, preferably 100 to 300 keV. The irradiation amount of the electron beam is usually about 2 to 15 Mrad.

  As the ionizing radiation curable resin, a monomer having a radically polymerizable unsaturated group such as (meth) acryloyl group or (meth) acryloyloxy group or a cationically polymerizable functional group such as epoxy group in the molecule, It consists of a polymer or polymer. These monomers, prepolymers or polymers are used alone or in combination. In this specification, (meth) acrylate is used in the meaning of acrylate or methacrylate. The ionizing radiation means an electromagnetic wave or charged particle beam having an energy quantum capable of polymerizing or cross-linking molecules, and is usually an ultraviolet ray or an electron beam.

  Examples of the prepolymer having a radical polymerizable unsaturated group include polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, triazine (meth) acrylate, and polyvinylpyrrolidone. This prepolymer usually has a molecular weight of about 10,000 or less. When the molecular weight exceeds 10,000, the cured resin layer has insufficient surface properties such as scratch resistance, abrasion resistance, chemical resistance, and heat resistance. The acrylate and methacrylate can be used in common, but the acrylate is more advantageous for the purpose of curing efficiently at a high speed and in a short time because the acrylate is faster in terms of the crosslinking curing rate with ionizing radiation. .

  Examples of the prepolymer having a cationically polymerizable functional group include epoxy resins such as bisphenol type epoxy resins, novolac type epoxy resins, and alicyclic epoxy resins, aliphatic vinyl ethers, aromatic vinyl ethers, urethane vinyl ethers, and ester vinyl ethers. And prepolymers such as vinyl ether resins, cyclic ether compounds, and spiro compounds.

  Examples of monomers having a radically polymerizable unsaturated group include (meth) acrylate compound monofunctional monomers such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, methoxyethyl ( (Meth) acrylate, methoxybutyl (meth) acrylate, butoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, N, N-dimethylaminomethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N , N-diethylaminoethyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, N, N-dibenzylaminoethyl (meth) acrylate, lauryl (meth) acrylate, isobornyl (meth) acrylate, ethyl carbitol ( Me ) Acrylate, phenoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, methoxypropylene glycol (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2 -(Meth) acryloyloxypropyl hydrogen terephthalate and the like.

  In addition, as a polyfunctional monomer having a radical polymerizable unsaturated group, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, di Propylene glycol (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tri Propylene glycol di (meth) acrylate, bisphenol-A-di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide tri (meth) acrylate , Pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin polyethylene oxide tri (meth) acrylate, tris (meth) acryloyloxy Examples thereof include ethyl phosphate.

  As the monomer having a cationic polymerizable functional group, a prepolymer monomer having the cationic polymerizable functional group can be used.

  When the above-mentioned ionizing radiation curable resin is cured by irradiating with ultraviolet rays, a photopolymerization initiator is added as a sensitizer. In the case of a resin system having a radically polymerizable unsaturated group, photoinitiators are acetophenones, benzophenones, thioxanthones, benzoin, benzoin, benzoin methyl ether, Michler benzoylbenzoate, Michler ketone, diphenyl sulfide, dibenzyl disulfide , Diethyl oxide, triphenylbiimidazole, isopropyl-N, N-dimethylaminobenzoate and the like can be used alone or in combination. In the case of a resin system having a cationically polymerizable functional group, an aromatic diazonium salt, an aromatic sulfonium salt, a metallocene compound, a benzoin sulfonate ester, a freeloxyxonium diallyl iodosyl salt, etc., should be used alone or as a mixture. Can do. In addition, generally the addition amount of these photoinitiators is about 0.1-10 weight part with respect to 100 weight part of ionizing radiation curable resins. The application method and application amount of the ionizing radiation curable resin are the same as those of the thermosetting resin, and the description thereof is omitted.

  When the surface protective layer 5 is given further scratch resistance and wear resistance, for example, inorganic particles such as α-alumina, silica, kaolinite, iron oxide, diamond, silicon carbide, etc. Is mentioned. Examples of the particle shape include a spherical shape, an elliptical shape, a polyhedral shape, a scale shape, and the like. Although there is no particular limitation, a spherical shape is preferable. Examples of the organic substance include synthetic resin beads such as a cross-linked acrylic resin and a polycarbonate resin. The particle size is usually about 3 to 200% of the film thickness. Among these, spherical α-alumina is particularly preferable because it has high hardness and a large effect on improving wear resistance, and it is relatively easy to obtain spherical particles. The blending ratio of the fine particles to the curable resin forming the surface protective layer 5 is 1 to 80 parts by weight with respect to 100 parts by weight of the curable resin.

  The surface protective layer 5 may be made of, for example, a well-known organic ultraviolet absorber such as benzotriazole, benzophenone, or triazine, or titanium dioxide having an average particle size of about 5 to 120 nm, depending on required physical properties. Inorganic ultraviolet absorbers such as cerium oxide and zinc oxide, known light stabilizers such as hindered amines, or known additives such as antistatic agents and leveling agents can be added.

  Next, the primer layers 3, 3 'will be described. The primer layer 3 is provided for the purpose of improving the adhesive strength between the synthetic resin transparent substrate layer 2 and the patterned low-gloss printing layer 4 or the surface protective layer 5, and the primer layer 3 ' It is provided for the purpose of improving the adhesive strength between the synthetic resin colored layer 2 ′ and the picture print layer 6. In particular, when the synthetic resin-made transparent base material layer 2 and the synthetic resin-made colored layer 2 ′ are olefin-based thermoplastic resins, the patterned low-gloss printing layer 4 or the surface protective layer 5 and the pattern printing layer are used. In order to improve the adhesive strength with 6, it is desirable to provide the primer layers 3, 3 ′. Examples of the resin used for the primer layers 3 and 3 ′ include ester resins, urethane resins, acrylic resins, polycarbonate resins, vinyl chloride-vinyl acetate copolymers, polyvinyl butyral resins, nitrocellulose resins, and the like. Can be used alone or mixed to form a coating composition or ink composition, which can be formed using an appropriate coating means such as a roll coating method or a gravure printing method.

  However, the primer layers 3, 3 'are particularly preferably formed of a resin comprising (i) a copolymer of an acrylic resin and a urethane resin and (ii) an isocyanate. That is, the copolymer of (i) an acrylic resin and a urethane resin comprises an acrylic polymer component having a hydroxyl group at the terminal (component A), a polyester polyol component having a hydroxyl group at both ends (component B), and a diisocyanate component (component). C) is mixed and reacted to form a prepolymer, and a chain extender (component D) such as diamine is further added to the prepolymer to extend the chain. By this reaction, polyester urethane is formed and an acrylic polymer component is introduced into the molecule to form an acrylic-polyester urethane copolymer having a hydroxyl group at the terminal. This acrylic-polyester urethane copolymer is formed by reacting the terminal hydroxyl group with the isocyanate of (ii) and curing it.

  As the component A, a linear acrylate polymer having a hydroxyl group at the terminal is used. Specifically, linear polymethyl methacrylate (PMMA) having a hydroxyl group at the terminal is preferable because it is excellent in weather resistance (particularly the property against photodegradation) and can be easily copolymerized with urethane. . The component A is an acrylic resin component in the copolymer, and those having a molecular weight of 5000 to 7000 (weight average molecular weight) are preferably used because of particularly good weather resistance and adhesiveness. In addition, the component A may be used only having a hydroxyl group at both ends, but a mixture having a conjugated double bond at one end is mixed with the above-mentioned one having a hydroxyl group at both ends. Is also good. By mixing the acrylic polymer in which the conjugated double bond remains, a layer in contact with the primer layer, for example, the ionizing radiation curable resin of the surface protective layer 5 and the conjugated double bond of the acrylic polymer react with each other. In addition, the adhesion between the ionizing radiation curable resin can be improved.

  Component B reacts with diisocyanate to form polyester urethane and constitutes a urethane resin component in the copolymer. The component B is a polyester diol having hydroxyl groups at both ends. Examples of the polyester diol include an addition reaction product of a diol compound having an aromatic or spiro ring skeleton and a lactone compound or a derivative thereof, or an epoxy compound, a condensation product of a dibasic acid and a diol, and a cyclic ester compound. Examples thereof include a derived polyester compound. Examples of the diol include short-chain diols such as ethylene glycol, propylene glycol, diethylene glycol, butanediol, hexanediol, and methylpentenediol, and alicyclic short-chain diols such as 1,4-cyclohexanedimethanol. Examples of the dibasic acid include adipic acid, phthalic acid, isophthalic acid, terephthalic acid, and the like. Preferred as the polyester polyol is adipic acid polyester using adipic acid or a mixture of adipic acid and terephthalic acid as the acid component, particularly preferably adipic acid, and 3-methylpentanediol and 1,4-cyclohexanedimethanol as the diol component. is there.

  In the primer layers 3 and 3 ′, the urethane resin component formed by the reaction of the component B and the component C gives flexibility to the primer layers 3 and 3 ′, and the synthetic resin transparent substrate layer 2 or the synthetic resin colored layer 2 ′. The acrylic resin component made of an acrylic polymer contributes to weather resistance and blocking resistance in the primer layers 3 and 3 '. In the urethane resin, the molecular weight of the component B may be within a range in which a urethane resin capable of sufficiently exhibiting flexibility in the primer layer is obtained. Adipic acid or a mixture of adipic acid and terephthalic acid, and 3-methylpentanediol In the case of a polyester diol composed of 1,4-cyclohexanedimethanol, 500 to 5000 (weight average molecular weight) is preferable.

  As the component C, an aliphatic or alicyclic diisocyanate compound having two isocyanate groups in one molecule is used. Examples of the diisocyanate include tetramethylene diisocyanate, 2,2,4 (2,4,4) -1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and 1,4′-cyclohexyl. A diisocyanate etc. can be mentioned. As the diisocyanate component, isophorone diisocyanate is preferable in terms of excellent physical properties and cost. When the above-mentioned components A to C are reacted, the equivalent ratio of the total hydroxyl group (may be an amino group) of the acrylic polymer, polyester polyol and chain extender described below and the isocyanate group is such that the isocyanate group becomes excessive. To.

  When the above three components A, B and C are reacted at 60 to 120 ° C. for about 2 to 10 hours, the isocyanate group of the diisocyanate reacts with the hydroxyl group at the end of the polyester polyol to form a polyester urethane resin component and an acrylic polymer. A compound in which a diisocyanate is added to a terminal hydroxyl group is also mixed, and a prepolymer is formed in a state where excess isocyanate groups and hydroxyl groups remain. As a chain extender, for example, a diamine such as isophorone diamine or hexamethylene diamine is added to this prepolymer, the isocyanate group is reacted with the chain extender, and the chain is extended so that the acrylic polymer component is contained in the polyester urethane molecule. The (i) acrylic-polyester urethane copolymer introduced and having a hydroxyl group at the terminal can be obtained.

  Addition of isocyanate of (ii) to acrylic-polyester urethane copolymer of (i), coating method, coating solution adjusted to necessary viscosity in consideration of coating amount after drying, gravure coating method, roll The primer layers 3 and 3 ′ may be formed by coating by a known coating method such as a coating method. The isocyanate of (ii) may be any isocyanate that can be crosslinked and cured by reacting with the hydroxyl group of the acrylic-polyester urethane copolymer of (i). An aliphatic isocyanate can be used, and an aliphatic isocyanate is particularly desirable from the viewpoint of thermal discoloration prevention and weather resistance. Specifically, a monomer such as tolylene diisocyanate, xylylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, or a multimer such as a dimer or trimer thereof, or And polyisocyanates such as derivatives (adducts) obtained by adding these isocyanates to polyols. In addition, although the thing of the structure which provided the primer layers 3 and 3 'was shown in the decorative sheet | seat 1 and 1' of FIG. 1, FIG. 2, this is a decorative sheet specification corresponding to a high level request | requirement, request | requirement When the level is low, these primer layers 3, 3 ′ are not necessarily provided.

As the coating amount after drying of the primer layer 3,3 'is from 1 to 20 g / m ^2, preferably from 1 to 5 g / m ^2. The primer layers 3 and 3 ′ may be layers to which additives such as silica powder, additives such as a light stabilizer and a colorant are added as necessary.

  Further, although not shown, a primer layer is provided on the back surface of the synthetic resin colored layer 2 ′ shown in FIG. 2 (the surface opposite to the surface on which the pattern printing layer 6 is provided), and the decorative sheet 1 ′ is used for a decorative board. You may comprise so that the adhesive force at the time of sticking to a base material (not shown) through an adhesive bond layer and making it a decorative board may improve. The primer layer provided on the back surface of the synthetic resin colored layer 2 ′ (the surface opposite to the surface provided with the pattern printing layer 6) may be appropriately provided as necessary when the adhesive force is insufficient. Is. Note that the resin described in the primer layers 3 and 3 ′ may be appropriately selected and used for the primer layer in this case. Moreover, as an adhesive agent used for the adhesive bond layer which sticks decorative sheet 1 'and the base material for decorative boards, any type, such as a thermoplastic resin type | system | group, a thermosetting resin type | system | group, rubber | gum (elastomer) type | system | group, is mentioned, for example. It may be an adhesive. These may be known ones or commercially available products. Thermoplastic resin adhesives include polyvinyl acetate resin, polyvinyl alcohol, polyvinyl acetal (polyvinyl formal, polyvinyl butyral, etc.), cyanoacrylate, polyvinyl alkyl ether, polyvinyl chloride, polyamide, polymethyl methacrylate, nitrocellulose, acetic acid Cellulose, thermoplastic epoxy, polystyrene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and the like can be mentioned. Examples of thermosetting resin adhesives include urea resins, melamine resins, phenol resins, Resorcinol resin, furan resin, epoxy resin, unsaturated polyester resin, polyurethane resin, polyimide resin, polyamideimide, polybenzimidazole, polybenzothiazole, and the like can be given. Rubber-based adhesives include natural rubber, recycled rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, butyl rubber, polysulfide rubber, silicone rubber, polyurethane rubber, stereo rubber (synthetic natural rubber), ethylene propylene rubber, Examples include block copolymer rubber (SBS, SIS, SEBS, etc.).

  The decorative board substrate (not shown) may be a medium-density fiber board (MDF), a high-density fiber board (HDF), a wood-based substrate such as particle board or plywood, a cement board, or silicic acid. Inorganic base materials, such as a calcium plate, a metal plate, etc. can be mentioned. As the thickness of the base material for decorative plate, a thickness of 0.5 mm or more is appropriate for a metal plate, and 1.0 mm or more is suitable for practical use in other cases.

  In addition, the concave pattern 7 can be formed by heating press or hairline processing, and as the pattern, for example, a conduit groove, a stone plate surface unevenness, a cloth surface texture, a satin texture, a sand texture, a hairline, a multiline groove, Mirror surface etc.

  Next, the present invention will be described in more detail with reference to the following examples.

  Acrylic urethane printing ink (acrylic polyol is the main ingredient and isocyanate is added as a curing agent on one side of a colored polypropylene sheet with a corona discharge treatment on both sides (colored layer made of synthetic resin as used in the present invention). A two-component curable printing ink) and a urethane / nitrified cotton primer layer on the other surface by gravure printing, and then the two-component curable printing ink on the surface of the patterned printing layer. Polypropylene system in which a 2 μm-thick adhesive layer made of urethane resin is formed, and an ethylene / propylene / butene copolymer as a main component is added to the surface of the adhesive layer, and a benzotriazole UV absorber and a hindered amine radical scavenger are added Thermoplastic elastomer is melt-extruded by heating with a T-die extruder, and a transparent resin layer (this An intermediate sheet formed synthetic resin transparent substrate layer) as referred in the invention were prepared.

  A transparent primer layer having a thickness of 2 μm is formed on the surface of the transparent resin layer of the intermediate sheet. The transparent primer layer has a thickness of 2 μm and is made of a two-component curable urethane resin containing an acrylic / urethane block copolymer as a main component and isocyanate as a curing agent. On the surface of the primer layer, silica particles 5 having an average particle size of 4 μm with respect to 100 parts by weight of a transparent printing ink using a polyester urethane resin having a number average molecular weight of 10,000 and a glass transition temperature (Tg) of −40.0 ° C. as a vehicle. After forming a conduit pattern layer (patterned low gloss printing layer as referred to in the present invention) by gravure printing using a printing ink composition containing parts by weight, the entire surface on which the conduit pattern layer is formed is formed. Ionizing radiation curable resin composition (100 parts by weight of urethane acrylate ionizing radiation curable resin surface coated with silicone oil And a transparent surface protective layer having a thickness of 5 μm is formed by irradiating an electron beam (acceleration voltage: 125 KeV, irradiation amount: 5 Mrad), and then applying the transparent surface. A decorative sheet in which a concave pattern was formed by embossing from the protective layer side was produced.

  A decorative sheet was prepared in the same manner as in Example 1 except that the conduit pattern layer was formed with a transparent printing ink using a polyester urethane resin containing no silica particles as a vehicle.

  Except for forming a conduit pattern layer using a printing ink composition in which the vehicle is replaced with a polyester-based urethane resin and an acrylic urethane resin (a two-component curable resin containing an acrylic polyol as a main component and an isocyanate as a curing agent) is used. A decorative sheet was produced in the same manner as in Example 1.

[Comparative Example 1]
A decorative sheet was produced in the same manner as in Example 1 except that the conduit pattern layer was formed using a printing ink composition in which an acrylic resin was used instead of the polyester urethane resin.

[Comparative Example 2]
A decorative sheet was prepared in the same manner as in Example 1 except that the conduit pattern layer was formed using a printing ink composition in which the vehicle was replaced with a polyester-based urethane resin and a cellulose-based resin was used.

[Comparative Example 3]
A solid pattern printing layer (gloss adjustment layer) and the solid are printed by a gravure printing method using a printing ink having a urethane resin containing 10 parts by weight of acrylic resin beads on the surface of the transparent resin layer of the intermediate sheet prepared in Example 1. A conduit pattern layer (matte printing layer) with acrylic matte printing ink (black acrylic matting printing ink containing 45% by weight of acrylic resin beads and carbon black as a pigment) on the pattern printing layer surface A decorative sheet having a concavo-convex pattern due to the difference in surface gloss was formed.

  For the decorative sheets of Examples 1 to 3 and Comparative Examples 1 to 3 prepared above, evaluation of gloss, design visibility due to gloss difference, stain resistance, weather resistance, and abrasion resistance are evaluated by the following evaluation methods. The results are summarized in Table 1.

〔Evaluation methods〕
・ Gloss evaluation:
Using a gloss meter (manufactured by Murakami Color Research Laboratory: GMX-203 (trade name)), the gloss values in the high gloss region and the low gloss region were measured under the condition of an incident angle of 75 degrees. The higher the number, the higher the gloss (high gloss), and the lower the number, the lower the gloss (low gloss).
・ Evaluation of design visibility by gloss difference:
From the surface side of the decorative sheet, the part of the conduit pattern layer and other parts were visually observed to evaluate the visibility of the conduit pattern.
(Evaluation Criteria)-Good design where the conduit design is clearly recognized is indicated by ◎, and if the design is recognized but slightly lacking in clarity, it is indicated by ○, and the design of the conduit design is slightly recognized. As shown in FIG. 1, those having no problem in practical use are indicated by Δ, and those having no duct pattern are indicated by ×.
・ Contamination resistance:
Contaminants were applied to the surface of the decorative sheet in accordance with JIS K-6902, and the remaining condition of the contaminants after wiping was visually evaluated according to the following evaluation criteria.
(Evaluation Criteria)-Excellent change is marked with ◎, and slight change compared with before applying contaminant, marked with good, marked with ○, In comparison, there was a change but there was no problem in practical use.
-Weatherproof adhesion:
After exposing the decorative sheet for 100 hours using an i-super UV tester [Iwasaki Electric Co., Ltd .: SUV-W231 (trade name)], a 25 mm wide cellophane tape [Nichiban Co., Ltd .: Cellotape (registered trademark)] ] Was affixed to the surface of the decorative sheet, peeled off rapidly in the 45 ° direction, and the peeled surface of the decorative sheet was visually evaluated according to the following evaluation criteria.
(Evaluation Criteria)-Good exfoliation is marked with ◎, exfoliation of the design is recognized, but slight is marked with good, and exfoliation of the pattern is clearly recognized Those with no problem in practical use were indicated by Δ, and those with remarkably peeled pattern were indicated by ×.
・ Abrasion resistance:
Steel wool (# 0000) is attached to a weight adjusted to a load of 29.4 kPa (300 g / cm ² ), the surface of the decorative sheet is rubbed 20 times, and the surface change is visually evaluated according to the following evaluation criteria. did.
(Evaluation Criteria)-Excellent surface quality is indicated by ◎, and surface change is observed, but minor surface is indicated by ◯, and surface change is clearly recognized, but practical problems The case where there was no surface change was indicated by Δ and the case where the surface change was remarkably recognized was indicated as X by failure.

  As is clear from Table 1, the decorative sheet of Example 1 has a low gloss region (conduit pattern layer region) and a high gloss region (region other than the conduit pattern layer), and the low gloss region is visually concave. And the high gloss region has a realistic unevenness that is visually recognized as a convex portion, and the conduit pattern layer and the pattern print layer are at least through a transparent resin layer (80 μm thickness in the embodiment). Because it is formed, it can be made into a decorative sheet that is also excellent in design with a sense of depth (depth), and in any physical properties such as contamination resistance, weather resistance adhesion, and abrasion resistance required during use. It has excellent performance. A so-called two-part curable type comprising a patterned low-gloss printing layer made of a polyester urethane resin that does not contain fine particles, and a vehicle in which the patterned low-gloss printing layer is blended with a polyol component and an isocyanate component. Although Example 3 formed using printing ink is not as good as Example 1, it also has a realistic feeling of unevenness and depth (depth) in design and also has excellent performance in various resistances. .

It is a layer block diagram which shows the basic composition of the decorative sheet concerning this invention schematically. It is a layer block diagram which shows one Example of the decorative sheet concerning this invention schematically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 'decorative sheet 2 Synthetic resin transparent base material layer 2' Synthetic resin colored layer 3, 3 'Primer layer 4 Pattern-like low gloss printing layer 5 Surface protective layer 6 Picture printing layer 7 Recessed pattern 8 Adhesive layer 61 Pattern print layer 62 Solid pattern print layer

Claims (7)

After providing a patterned low-gloss printing layer on one surface of the synthetic resin transparent substrate layer, a surface protective layer is provided on the entire surface of the one surface, and pattern printing is performed on the other surface side of the synthetic resin transparent substrate layer. A decorative sheet provided with a layer, wherein the patterned low gloss printing layer is formed of a printing ink comprising a vehicle in which a urethane resin obtained by reacting a polyol component and an isocyanate component is kneaded at least. Makeup sheet. The decorative sheet according to claim 1, wherein the printing ink has fine particles added thereto. 2. The decorative sheet according to claim 1, wherein a synthetic resin colored layer is provided on the other surface side of the synthetic resin transparent substrate layer so as to sandwich the pattern printing layer. The decorative sheet according to claim 1, wherein a concave pattern is provided on the surface protective layer side. The decorative sheet according to claim 1, wherein the surface protective layer is made of a curable resin. The decorative sheet according to claim 5, wherein the curable resin is an ionizing radiation curable resin. A decorative board, wherein the decorative sheet according to any one of claims 1 to 6 is attached to a base for a decorative board via an adhesive layer.

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