JP6191110B2 - Decorative sheet - Google Patents

Description

  The present invention relates to a decorative sheet.

  Conventionally, development of a decorative sheet having excellent scratch resistance has been desired as a decorative sheet for building materials. For example, a decorative sheet having a surface protective layer containing an ionizing radiation curable resin has excellent scratch resistance. In particular, there is a method for further improving the scratch resistance by making the thickness of the surface protective layer larger than that of a conventional decorative sheet. However, when the thickness of the surface protective layer is increased, it becomes difficult to obtain the smoothness of the surface protective layer, or bubbles are easily generated. As a result, there is a problem in that coating defects such as uneven stripes, uneven coating, and missing coating are likely to occur when the surface protective layer is applied.

  For the purpose of improving the scratch resistance and solving the problem related to the deterioration of the surface state, a method of coating and forming a surface protective layer containing an ionizing radiation curable resin is being studied. However, in such a method, distortion (internal stress) occurs between adjacent layers due to shrinkage stress generated when the ionizing radiation curable resin is cured. As a result, there is a problem that sufficient adhesion cannot be imparted between the surface protective layer and the surface protective layer (surface protective layer), and peeling occurs between the surface protective layers during use.

  Patent Document 1 describes a method of containing an ionizing radiation curable resin and an isocyanate in the second layer (outermost layer) as a method for improving the adhesion between the surface protective layers. However, in this method, sufficient adhesion between the surface protective layers can be obtained, but the pot life of the paint is shortened in the coating process, and the fluidity of the paint is lowered. As a result, there is a problem that coating defects such as uneven stripes and missing coats are likely to occur on the outermost surface. Moreover, since isocyanate is contained in the outermost surface protective layer (coat layer), there is a problem that the coating film becomes hard and easily cracked.

JP 2012-071421

  Accordingly, an object of the present invention is to provide a decorative sheet excellent in scratch resistance, adhesion between surface protective layers, and impact resistance.

  As a result of intensive studies to achieve the above object, the present inventor has found that the decorative sheet can achieve the above object when the surface protective layer is formed with a specific layer structure, and completes the present invention. It came.

That is, the present invention relates to the following decorative sheet.
1. A decorative sheet having, in order, a first surface protective layer and a second surface protective layer on a substrate sheet,
(1) The first surface protective layer is formed from a resin composition containing a resin having an isocyanate and a hydroxyl group in the molecule, and the resin having the hydroxyl group in the molecule has a weight average molecular weight of 80,000 to 10000. Selected from the group consisting of polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol, polyurethane polyol, and copolymers formed by combining one or more of these. At least one,
(2) The second surface protective layer is formed of a resin composition having an ionizing radiation curable resin and a resin having a hydroxyl group in the molecule as a resin component, and the resin having the hydroxyl group in the molecule is a weight average. From a copolymer having a molecular weight of 80,000 to 100,000, polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol, polyurethane polyol, and a combination of one or more of these. At least one selected from the group consisting of:
A decorative sheet characterized by that.
2. Item 2. The decorative sheet according to Item 1, wherein the resin having the hydroxyl group in the molecule contained in the second surface protective layer is an acrylic polyol.
3. Item 3. The decorative sheet according to Item 1 or 2, wherein the resin composition forming the second surface protective layer contains no isocyanate.
4). Item 4. The decorative sheet according to any one of Items 1 to 3, wherein the ionizing radiation curable resin is an electron beam curable resin.
5. Item 5. The decorative sheet according to any one of Items 1 to 4, further comprising a pattern layer, a transparent resin layer, a primer layer, a first surface protective layer, and a second surface protective layer in this order on the substrate sheet.
6). Item 6. The decorative sheet according to any one of Items 1 to 5, wherein the decorative sheet surface is embossed.
7). The decorative material formed by bonding the base sheet side of the decorative sheet according to any one of Items 1 to 6 to an adherend.

  Hereinafter, the decorative sheet of the present invention will be described in detail.

≪Makeup sheet≫
The decorative sheet of the present invention is a decorative sheet having at least a first surface protective layer and a second surface protective layer in order on a base sheet,
(1) The first surface protective layer is formed from a resin composition containing isocyanate,
(2) The second surface protective layer is formed from a resin composition containing an ionizing radiation curable resin and a resin having a hydroxyl group in the molecule as a resin component.

  In the decorative sheet of the present invention having the above characteristics, since the first surface protective layer and the second surface protective layer satisfy the above specific conditions, scratch resistance, adhesion between the surface protective layers (the first surface protective layer and It is excellent in interlayer adhesion with the second surface protective layer (hereinafter also simply referred to as interlayer adhesion)) and impact resistance.

  The configuration of the decorative sheet of the present invention is not limited as long as the decorative sheet has at least a first surface protective layer and a second surface protective layer in order on the base sheet. Examples thereof include a decorative sheet in which a pattern layer, an adhesive layer, a transparent resin layer, a primer layer, a first surface protective layer, and a second surface protective layer are sequentially laminated on a base sheet. Hereinafter, each layer constituting the decorative sheet will be described as a representative example.

Base Sheet The decorative sheet of the present invention includes a base sheet, and at least a first surface protective layer and a second surface protective layer are sequentially laminated on the surface (front surface).

  As a base material sheet, what was formed, for example with the thermoplastic resin is suitable. Specifically, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, polycarbonate, polyethylene naphthalate, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer Examples thereof include polymers, ionomers, polyacrylic acid esters, and polymethacrylic acid esters. Among these, polyolefins such as polypropylene are preferable.

  The base material sheet may be colored. In this case, a coloring material (pigment or dye) can be added to the above thermoplastic resin for coloring. As the colorant, for example, inorganic pigments such as titanium dioxide, carbon black and iron oxide, organic pigments such as phthalocyanine blue, and various dyes can be used. These can be selected from one or more known or commercially available ones. Further, the addition amount of the colorant may be appropriately set according to the desired color tone.

  The base sheet contains various additives such as fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, antioxidants, UV absorbers, and light stabilizers as necessary. It may be.

  Examples of the filler include silica, clay, calcium carbonate, aluminum hydroxide, magnesium hydroxide, antimony trioxide, zinc borate, and a molybdenum compound. By including a filler, an effect of suppressing see-through, an effect of improving surface characteristics, and the like are obtained. About 0-100 mass parts is preferable with respect to 100 mass parts of resin components, and, as for content of a filler, about 10-50 mass parts is more preferable.

  Although the thickness of a base material sheet can be suitably set with the use of the final product, a usage method, etc., generally 50-250 micrometers is preferable and 50-100 micrometers is more preferable.

  If necessary, the base sheet may be subjected to corona discharge treatment on the surface (front surface) in order to enhance the adhesion of the ink for forming the pattern layer. What is necessary is just to implement the method and conditions of a corona discharge process according to a well-known method.

  Moreover, you may give a corona discharge process to the back surface of a base material sheet, and may form a back surface primer layer as needed.

Back surface primer layer A back surface primer layer may be provided on the back surface of the above-described base material sheet, if necessary. For example, it is advantageous when a base material sheet and an adherend are bonded to produce a decorative material.

  A back surface primer layer can be formed by apply | coating a well-known primer agent to the single side | surface or both surfaces of a base material sheet. Examples of the primer agent include a urethane resin-based primer agent made of an acrylic-modified urethane resin (acrylic urethane-based resin), a urethane-cellulose resin (for example, a resin obtained by adding hexamethylene diisocyanate to a mixture of urethane and nitrified cotton) ), A resinous primer agent made of a block copolymer of acrylic and urethane, and the like. You may mix | blend an additive with a primer as needed. Examples of the additive include fillers such as calcium carbonate and clay, flame retardants such as magnesium hydroxide, antioxidants, lubricants, foaming agents, ultraviolet absorbers, and light stabilizers. The blending amount of the additive can be appropriately set according to the product characteristics.

  Although the thickness of a back surface primer layer is not specifically limited, Usually, 0.1-10 micrometers, Preferably it is about 1-5 micrometers.

Pattern Pattern Layer The decorative sheet of the present invention may be provided with a pattern pattern layer on the surface (front surface) of the base sheet, if desired.

  The design pattern layer imparts a desired design (design) to the decorative sheet, and the type of the design is not limited. Examples thereof include a wood grain pattern, a stone pattern, a grain pattern, a tiled pattern, a brickwork pattern, a cloth pattern, a leather pattern, a geometric figure, a character, a symbol, and an abstract pattern.

  The method for forming the pattern layer is not particularly limited. For example, an ink obtained by dissolving (or dispersing) a known colorant (dye or pigment) in a solvent (or dispersion medium) together with a binder resin is used. What is necessary is just to form on the base-material sheet | seat surface by the printing method.

  Examples of colorants include inorganic pigments such as carbon black, titanium white, zinc white, dial, bitumen, cadmium red; azo pigments, lake pigments, anthraquinone pigments, quinacridone pigments, phthalocyanine pigments, isoindolinone pigments, dioxazine pigments. Organic pigments such as aluminum powder, metal powder pigments such as bronze powder, pearlescent pigments such as titanium oxide-coated mica and bismuth oxide chloride; fluorescent pigments; These colorants can be used alone or in admixture of two or more. These colorants may further contain fillers such as silica, extender pigments such as organic beads, neutralizing agents, surfactants and the like.

  As binder resin, polyester urethane resin, polyester urethane resin with hydrophilic treatment, polyester, polyacrylate, polyvinyl acetate, polybutadiene, polyvinyl chloride, chlorinated polypropylene, polyethylene, polystyrene, polystyrene-acrylate A polymer, a rosin derivative, an alcohol adduct of a styrene-maleic anhydride copolymer, a cellulose resin, or the like can be used in combination.

  More specifically, for example, polyurethane-polyacrylic resin, polyacrylamide resin, poly (meth) acrylic acid resin, polyethylene oxide resin, poly N-vinylpyrrolidone resin, water-soluble polyester resin, water-soluble Polyamide resins, water-soluble amino resins, water-soluble phenol resins, other water-soluble synthetic resins; water-soluble natural polymers such as polynucleotides, polypeptides, polysaccharides, etc. can be used. Further, for example, natural rubber, synthetic rubber, polyvinyl acetate resin, (meth) acrylic resin, polyvinyl chloride resin, polyurethane-polyacrylic resin modified or mixed resin, and other resins can also be used. The binder resin can be used alone or in combination of two or more.

  Examples of the printing method used for forming the pattern layer include a gravure printing method, an offset printing method, a screen printing method, a flexographic printing method, an electrostatic printing method, and an inkjet printing method. When forming a solid pattern pattern layer (also referred to as a colored concealment layer), for example, a gravure coating method, a gravure reverse coating method, a roll coating method, a knife coating method, an air knife coating method, a die coating Various coating methods such as a method, a lip coat method, a comma coat method, a kiss coat method, a flow coat method, and a dip coat method are also included.

  In addition to the above, for example, the hand-drawn method, the ink-sink method, the photographic method, the transfer method, the laser beam drawing method, the electron beam drawing method, the metal partial evaporation method, the etching method, etc. are used or combined with other forming methods. It may be used.

  The thickness of the pattern layer is not particularly limited and can be set as appropriate according to product characteristics. The layer thickness at the time of coating is about 1 to 15 μm, and the layer thickness after drying is about 0.1 to 10 μm.

Adhesive layer The decorative sheet of the present invention may be provided with an adhesive layer on the surface (front surface) of the base sheet between the pattern layer and the transparent resin layer, if desired.

  The adhesive layer may be transparent or translucent as long as the pattern layer can be recognized. Moreover, the adhesive agent used by an adhesive bond layer is not specifically limited, According to the component etc. which comprise a design pattern layer or a transparent resin layer, it can select suitably. Examples of known adhesives in the field of decorative sheets include thermoplastic resins such as polyamide resins, acrylic resins and vinyl acetate resins, and thermosetting resins such as urethane resins. These adhesives are used individually by 1 type or in combination of 2 or more types. Further, a two-component curable polyurethane resin or polyester resin using isocyanate as a curing agent can also be applied.

  Moreover, well-known easy adhesion processes, such as a corona discharge process, a plasma process, a degreasing process, and a surface roughening process, can also be given to an adhesion surface as needed.

  The adhesive layer can be formed, for example, by applying an adhesive on the pattern layer, drying it once, and then laminating a transparent resin layer. The method of applying the adhesive is not particularly limited, and examples thereof include roll coating, curtain flow coating, wire bar coating, reverse coating, gravure coating, gravure reverse coating, air knife coating, kiss coating, blade coating, smooth coating, and comma coating. The method can be adopted.

  The thickness of the adhesive layer varies depending on the transparent resin layer, the type of adhesive used, and the like, but is generally about 0.1 to 30 μm.

Transparent resin layer In the decorative sheet of the present invention, a transparent resin layer may be laminated between the surface (front surface) of the base sheet and the first surface protective layer.

  The resin constituting the transparent resin layer is not limited as long as it is transparent when the lower pattern pattern layer is present, or is translucent within a range where the lower pattern pattern layer can be visually recognized. Examples of such resins include polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, and ethylene-acrylic acid ester copolymer. , Ionomer, polymethylpentene, polyacrylate, polymethacrylate, polycarbonate, cellulose triacetate and the like. The said resin can be used individually or in combination of 2 or more types. Moreover, the copolymer which has these resins as a main component can also be used.

  Among the above, polyolefin resins such as polypropylene are preferable. More preferably, it is a polyolefin resin having stereoregularity. When using a polyolefin resin, it is desirable to form a transparent resin layer by extruding a molten polyolefin resin.

  As the polyolefin resin, either a homopolymer or a copolymer can be used. For example, in the case of a polypropylene resin, homopolypropylene resin, random polypropylene resin, block polypropylene resin and the like can be mentioned. As the polyolefin resin, a commercially available product (for example, Prime Polymer Co., Ltd. (Prime TPO “J-5900”, Prime Polypro “F219DA”), etc.) can be used.

  For the transparent resin layer, if necessary, a filler, matting agent, foaming agent, flame retardant, lubricant, antistatic agent, antioxidant, ultraviolet absorber, light stabilizer, radical scavenger, soft component Various additives such as rubber (for example, rubber) may be included.

  The thickness of the transparent resin layer is not particularly limited, but if the thickness of the transparent resin layer is too thin, the wear resistance is lowered. On the other hand, if it is too thick, problems such as fluffing at the time of cutting occur.

  If necessary, the transparent resin layer may be subjected to corona discharge treatment on the surface (front surface) in order to enhance the adhesion with the upper primer layer.

Primer layer In the decorative sheet of the present invention, a primer layer may be provided between the transparent resin layer and the first surface protective layer, if desired. The primer layer has a function of improving the adhesion (adhesion) between the transparent resin layer and the first surface protective layer. Moreover, it has an effect which makes it difficult to produce a fine crack and whitening in the extending | stretching part of a 1st surface protective layer. Moreover, formation of a 1st surface protective layer can be made easy by providing a primer layer. The primer layer is not particularly limited as long as it is transparent, and includes any of colorless and transparent, colored and transparent, and translucent.

  The primer layer can be formed by applying a known or commercially available primer on the transparent resin layer. In particular, the primer layer is preferably a layer formed by crosslinking a resin. Examples of the primer agent for forming such a layer include a urethane resin primer agent made of an acrylic-modified urethane resin and the like, a resin primer agent made of a block copolymer of acrylic and urethane, and the like. These primer agents are used alone or in combination of two or more.

  The primer layer may contain silica as a matting agent. 0.1-50 mass parts is preferable with respect to 100 mass parts of resin components, and, as for content of the silica in a primer agent, 10-40 mass parts is more preferable. Furthermore, you may make a primer agent contain a well-known additive as needed. For example, the adhesion between the transparent resin layer and the first surface protective layer can be further improved by including a hexamethylene diisocyanate curing agent in the primer agent. Moreover, you may add various weathering agents, such as a ultraviolet absorber and a light stabilizer, to a primer layer.

  The primer layer can be formed by a direct coating method, for example, gravure coating, gravure reverse coating, gravure offset coating, spin coating, roll coating, reverse roll coating, kiss coating, wheeler coating, dip coating, solid coating by silk screen, wire A bar coat, a flow coat, a comma coat, a pouring coat, a brush coat, a spray coat, etc. can be used.

  The thickness of the primer layer is preferably about 0.1 to 10 μm. When the thickness is 0.1 μm or more, the effect of preventing the surface protective layer from cracking, breaking, whitening and the like can be sufficiently exerted. On the other hand, if the thickness of the primer layer is 10 μm or less, it is preferable that when the primer layer is applied, the coating film is stable in drying and curing, and the moldability does not vary. From the above points, the thickness of the primer layer is more preferably 0.1 to 10 μm.

First surface protective layer The decorative sheet of the present invention has a second surface protective layer described later as the outermost surface layer, and the first surface protective layer is formed on the back side of the second surface protective layer. .

  The first surface protective layer is formed from a resin composition containing isocyanate. By containing the isocyanate in the first surface protective layer, the isocyanate and a resin containing a hydroxyl group contained in the second surface protective layer, which will be described later, react to form a urethane bond. Therefore, it becomes possible to make the adhesiveness of a 1st surface protective layer and a 2nd surface protective layer stronger, and the decorative sheet excellent in interlayer adhesiveness is obtained.

  As the isocyanate contained in the resin composition, for example, a polyvalent isocyanate having two or more isocyanate groups in the molecule is used. Specifically, aromatic isocyanates such as 2,4-tolylene diisocyanate, xylylene diisocyanate (XDI), 4,4′-diphenylmethane diisocyanate; hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), hydrogenated tolylene diene Aliphatic (or alicyclic) isocyanates such as isocyanate and hydrogenated diphenylmethane diisocyanate are used. Alternatively, adducts or multimers of the above various isocyanates can be used. For example, there are tolylene diisocyanate adducts, tolylene diisocyanate trimers, and the like. In addition, isocyanate can be used 1 type or in combination of 2 or more types.

  The preferred isocyanate is at least one selected from the group consisting of hexamethylene diisocyanate, isophorone diisocyanate and xylylene diisocyanate.

  Although content of isocyanate is not specifically limited, 1-30 mass parts is preferable with respect to 100 mass parts of resin components mentioned later.

  The resin composition forming the first surface protective layer contains a resin component in addition to the isocyanate. The resin component is not particularly limited, and an ionizing radiation curable resin, a resin having a hydroxyl group in the molecule, a resin having a group containing active hydrogen, and the like can be used. One type of resin component can be used in combination of two or more types.

  As the ionizing radiation curable resin, a resin similar to the ionizing radiation curable resin contained in the second surface protective layer described later can be used.

  As the resin having a hydroxyl group in the molecule, a resin similar to a resin having a hydroxyl group contained in the second surface protective layer described later in the molecule can be used. The resin having a preferred hydroxyl group in the molecule is the same as in the case of the second surface protective layer.

  The resin having a group containing active hydrogen refers to a resin having a group containing active hydrogen such as a carboxyl group, an amino group, or a mercapto group. The group containing the active hydrogen can react with an isocyanate group in the same manner as the hydroxyl group. Specific examples of the resin having a group containing active hydrogen include unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, and melamine-urea. Examples thereof include thermosetting resins such as condensation resins, silicon resins, and polysiloxane resins.

  The resin component in the resin composition is preferably at least one selected from the group consisting of an ionizing radiation curable resin and a resin having a hydroxyl group in the molecule, a resin having a hydroxyl group in the molecule, or an ionization A radiation curable resin and a resin having a hydroxyl group in the molecule are more preferable, and a resin having a hydroxyl group in the molecule is more preferable. In particular, when the resin component is a resin having a hydroxyl group in the molecule, or an ionizing radiation curable resin and a resin having a hydroxyl group in the molecule, the resin having the hydroxyl group in the molecule is soft and has excellent workability. When the resin component is a resin having a hydroxyl group in the molecule, it reacts with isocyanate contained in the resin composition forming the first surface protective layer, thereby forming a urethane bond in the resin composition and curing. Therefore, not only is the processability excellent, but it is not necessary to perform a treatment for curing the resin composition (for example, a curing treatment such as irradiation with ionizing radiation or heat treatment), and therefore the production process can be reduced.

  When the ionizing radiation curable resin and the resin having a hydroxyl group in the molecule are used in combination, the content of the resin having a hydroxyl group in the molecule is preferably 1 to 95 parts by mass with respect to 100 parts by mass of the ionizing radiation curable resin.

  As the ionizing radiation used for curing the ionizing radiation curable resin, the same method as the ionizing radiation used when forming the second surface protective layer described later can be used.

  The first surface protective layer may contain a plasticizer, a stabilizer, a filler, a dispersant, a colorant such as a dye and a pigment, a solvent, a matte material, and the like, if necessary. Moreover, in the range which does not impair the effect of this invention, you may contain a weathering agent.

  The first surface protective layer can be formed by, for example, applying a resin composition containing isocyanate on a transparent resin layer by a known coating method such as gravure coating or roll coating, and then curing the resin. In the case of an ionizing radiation curable resin, the resin is cured by ionizing radiation. In the case of a resin having a hydroxyl group in the molecule, the resin is cured by reacting with isocyanate.

  The thickness (layer thickness) of the first surface protective layer is not particularly limited, and can be appropriately set according to the characteristics of the final product, but is usually 0.1 to 50 μm, preferably 1 to 20 μm.

Second surface protective layer In the decorative sheet of the present invention, the second surface protective layer is formed as the outermost surface layer.

  The second surface protective layer is formed from a resin composition containing an ionizing radiation curable resin and a resin having a hydroxyl group in the molecule as a resin component. By containing the ionizing radiation curable resin in the second surface protective layer, it is excellent in scratch resistance and impact resistance. Moreover, by containing the resin which has a hydroxyl group in a molecule | numerator in a 2nd surface protective layer, the isocyanate in the resin composition which forms the said resin and the above-mentioned 1st surface protective layer reacts, and forms a urethane bond. Therefore, it becomes possible to make the adhesiveness of a 1st surface protective layer and a 2nd surface protective layer stronger, and the decorative sheet excellent in interlayer adhesiveness is obtained.

  The ionizing radiation curable resin is not particularly limited, and a prepolymer (including an oligomer) and / or a monomer containing a functional group capable of undergoing a polymerization and crosslinking reaction by irradiation with ionizing radiation such as ultraviolet rays and electron beams as a main component. A transparent resin can be used. These prepolymers or monomers can be used alone or in combination. The curing reaction is usually a cross-linking curing reaction.

  Specifically, as the prepolymer or monomer, a compound having in the molecule a radically polymerizable unsaturated group such as a (meth) acryloyl group or (meth) acryloyloxy group, or a cationically polymerizable functional group such as an epoxy group. Is mentioned. Further, a polyene / thiol prepolymer based on a combination of polyene and polythiol is also preferable. Here, the (meth) acryloyl group means an acryloyl group or a methacryloyl group.

  Examples of the prepolymer having a radically polymerizable unsaturated group include polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, triazine (meth) acrylate, and silicone (meth) acrylate. Etc. These weight average molecular weights are usually preferably about 250 to 100,000. As a monomer which has a radically polymerizable unsaturated group, methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenoxyethyl (meth) acrylate etc. are mentioned as a monofunctional monomer, for example. Examples of the polyfunctional monomer include diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide tri (meth) acrylate, dipentaerythritol tetra ( And (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

  Examples of the prepolymer having a cationic polymerizable functional group include prepolymers of epoxy resins such as bisphenol type epoxy resins and novolac type epoxy compounds, and vinyl ether type resins such as fatty acid type vinyl ethers and aromatic vinyl ethers. Examples of the thiol include polythiols such as trimethylolpropane trithioglycolate and pentaerythritol tetrathioglycolate. Examples of the polyene include those in which allyl alcohol is added to both ends of polyurethane by diol and diisocyanate.

  As the ionizing radiation used for curing the ionizing radiation curable resin, electromagnetic waves or charged particles having energy capable of causing a curing reaction of molecules in the ionizing radiation curable resin (composition) are used. Usually, ultraviolet rays or electron beams may be used, but visible light, X-rays, ion rays, or the like may be used.

  As the ultraviolet light source, for example, 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, a metal halide lamp can be used. As a wavelength of ultraviolet rays, 190 to 380 nm is usually preferable.

  As the electron beam source, for example, various electron beam accelerators such as a cockcroft Walton 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. Among these, those capable of irradiating electrons having energy of 100 to 1000 keV, preferably 100 to 300 keV are preferable.

  As the resin having a hydroxyl group (—OH group) in the molecule, for example, a resin having two or more hydroxyl groups in the molecule can be used. Specific examples include polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol, polyurethane polyol, and copolymers thereof. The resin having a hydroxyl group in the molecule can be used alone or in combination of two or more. Among these, at least one selected from the group consisting of acrylic polyol, polyurethane polyol, and acrylic-urethane polyol is preferable, and acrylic polyol is more preferable.

  The content of the ionizing radiation curable resin and the resin having a hydroxyl group in the molecule may be 10 to 100 parts by mass of the resin having a hydroxyl group in the molecule with respect to 100 parts by mass of the ionizing radiation curable resin. preferable.

  For the second surface protective layer, organic resin particles such as inorganic particles such as α-alumina, chromium oxide, iron oxide and diamond, synthetic resin beads such as crosslinked acrylic, etc. for the purpose of further improving scratch resistance or scratch resistance You may contain powder particles, such as. Various shapes of powder particles are used, and particularly when a spherical shape or a shape similar to a spherical shape is used, the scratch resistance is good. As for the content, when containing the said powder particle, 1-30 mass parts is preferable with respect to 100 mass parts of resin components which form a 2nd surface protective layer. The said powder particle can be used 1 type, or 2 or more types.

  A matte material may be used for the second surface protective layer for the purpose of further enhancing the matte effect of the surface. Matte materials include silica, calcium silicate, aluminum silicate, magnesium silicate, kaolin, mica, talc, and other inorganic pigments; titanium dioxide, calcium carbonate, barium carbonate, and other inorganic pigments; polyurethane, polystyrene, polyamide, poly And organic pigments such as vinyl chloride and acrylic fine polymer particles. Among these, silica is preferable from the viewpoint that the matting effect per mass of the matting material is high. When it contains the said mat | matte material, the content is 1-30 mass parts with respect to 100 mass parts of resin components which form a 2nd surface protective layer. In addition, the said mat | matte material can be used 1 type, or 2 or more types.

  The second surface protective layer may contain particles for the purpose of improving anti-slip properties. Examples of the particles include inorganic particles such as silica and silicone resin (powder, beads); organic material powders such as acrylic, crosslinked alkyl, crosslinked styrene, inzoguanamine resin, urea-formaldehyde resin, phenol resin, polyethylene, and nylon. Examples thereof include beads. When the particles are contained, the content is preferably 3 to 50 parts by mass with respect to 100 parts by mass of the resin component forming the second surface protective layer. The said particle | grain can be used 1 type, or 2 or more types.

  The second surface protective layer may contain an ultraviolet absorber and a light stabilizer in order to improve the weather resistance. Examples of the ultraviolet absorber include benzotriazole, benzophenone, salicylate, and triazine. In addition, when the resin layer is cured by irradiating with ultraviolet rays, as photopolymerization initiators, acetophenones, benzophenones, Michler benzoylbenzoate, α-aminoxime ester, tetramethylthiuram monosulfide, thioxanthones, aromatic N-butylamine, triethylamine, tri-n-butylphosphine, etc. can be used as photopolymerization accelerators (sensitizers) such as group diazonium salts, aromatic sulfonium salts, and metathelons. Examples of the light stabilizer include hindered amine light stabilizers. More specifically, bis- (2,2,6,6-tetramethyl-4piperidinyl) sebacate, bis- (N-methyl 2,2,6,6-tetramethyl-4-piperidinyl) sebacate, etc. Examples thereof include compounds disclosed in Japanese Patent Publication No. 4-82625.

  The second surface protective layer may contain an antibacterial agent in order to impart antibacterial properties. Antibacterial agents include inorganic antibacterial agents and organic antibacterial agents. In particular, inorganic antibacterial agents are desirable because they are generally safer than organic antibacterial agents and are excellent in durability and heat resistance. Inorganic antibacterial agents are those in which antibacterial metals such as silver, copper and zinc are supported on various inorganic carriers. When the antibacterial agent is contained, the content is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin component of the second surface protective layer.

  The second surface protective layer may include a plasticizer, a stabilizer, a filler, a dispersant, a colorant such as a dye and a pigment, a solvent, and the like, as necessary. Moreover, in the range which does not impair the effect of this invention, you may contain functional agents, such as a deodorizer and an antiallergen agent.

  The resin composition forming the second surface protective layer preferably contains no isocyanate. When isocyanate is contained, the pot life of the paint is shortened in the coating process and the fluidity of the paint is lowered. As a result, there is a problem that coating defects such as uneven stripes and missing coats are likely to occur on the outermost surface. Moreover, when isocyanate is contained in the second surface protective layer, there is a problem that the layer becomes hard and easily cracked.

  The second surface protective layer is, for example, a known coating such as gravure coating or roll coating with a resin composition containing an ionizing radiation curable resin and a resin having a hydroxyl group in the molecule on the first surface protective layer. After coating by a construction method, it can be formed by curing the resin. The ionizing radiation curable resin is cured by ionizing radiation.

  The thickness (layer thickness) of the second surface protective layer is not particularly limited and can be appropriately set according to the properties of the final product, but is usually 0.1 to 50 μm, preferably 1 to 20 μm.

≪Method for manufacturing decorative sheet≫
Lamination of each layer constituting the decorative sheet of the present invention includes, for example, (1) providing a back primer layer on the back surface of the base sheet, and (2) forming a pattern layer on the front surface of the base sheet by printing. (3) forming an adhesive layer on the pattern printed pattern layer; (4) laminating a transparent resin layer on the adhesive layer by extrusion lamination; and (5) a surface of the transparent resin layer. After the corona discharge treatment, a primer layer is formed. (6) The first surface protective layer of the present invention is applied to the surface by a gravure coating method, and if necessary, an electron beam is irradiated. 7) The surface can be formed by applying the second surface protective layer of the present invention to the surface by a gravure coating method and irradiating with an electron beam.

  The decorative sheet of the present invention can be embossed. The embossing is performed to give a desired texture such as a wood grain pattern to the decorative sheet. For example, after the decorative sheet is heated and softened from the second surface protective layer side with an infrared non-contact type heater or the like, the texture is formed by pressing and shaping with an embossed plate having a concavo-convex pattern of a desired shape and cooling and fixing. Is granted. Embossing can be performed with a known single wafer or rotary embossing machine. Examples of the embossed concavo-convex pattern include a wood grain conduit groove, a float pattern (a concavo-convex pattern of a raised annual ring), a hairline, a grain, and a satin texture.

The backer layer decorative sheet may be provided with a backer layer (synthetic resin layer) on the back surface of the base sheet. By providing the backer layer, not only is it excellent in impact resistance, but it is also excellent in scratch resistance (particularly a dent scratch when a partial load is applied). However, the decorative sheet of the present invention can ensure sufficient impact resistance without forming a backer layer.

  As a method of forming the backer layer, it can be formed by extrusion molding of a molten resin. For example, extrusion molding using a T die can be suitably used. Further, when the backer layer is a multilayer, for example, a multi-manifold type or feed block type T-die may be used to perform multilayer simultaneous extrusion.

  As a method for adhering the base sheet and the backer layer, a method of adhering the base sheet and the backer layer obtained by extruding the molten resin by heat fusion, between the base sheet and the backer layer The method of making it adhere | attach by providing a back surface primer layer and / or an adhesive bond layer, etc. are mentioned. In addition, each content, such as a component of the said adhesive bond layer, a formation method, thickness, is the same as that of the above-mentioned adhesive bond layer.

  The resin constituting the backer layer is not limited, but is preferably a thermoplastic resin, for example, polyethylene, polypropylene, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polymethylene, polymethylpentene, polyethylene terephthalate, amorphous polyethylene terephthalate. (A-PET), highly heat-resistant polyalkylene terephthalate [for example, polyethylene terephthalate in which a part of ethylene glycol is substituted with 1,4-cyclohexanedimethanol, diethylene glycol or the like, so-called trade name PET-G (Eastman Chemical) (Company)) polybutylene terephthalate, polycarbonate, polyarylate, polyethylene naphthalate, polyethylene naphthalate-isophthalate copolymer, Polyimide, polystyrene, polyamide, ABS (acrylonitrile - butadiene - styrene copolymer) and the like. These resins can be used alone or in combination of two or more.

  The thickness of the backer layer can be set as appropriate depending on the use of the final product, the method of use, etc., but is generally preferably 100 to 800 μm.

  If necessary, the backer layer may be subjected to known easy adhesion treatment such as corona discharge treatment, plasma treatment, degreasing treatment, surface roughening treatment, and the like on the adhesion surface.

  A primer layer may be provided on the back surface of the backer layer. For example, it is advantageous when a backing material is produced by bonding a backer layer and an adherend. The contents of the primer layer, such as components, formation method, and thickness, are the same as those of the above-described back primer layer.

Cosmetic material A decorative material can be obtained by bonding and bonding an adherend to the back surface of the decorative sheet of the present invention.

  The material of various adherends is not particularly limited, and examples thereof include inorganic non-metallic materials, metallic materials, woody materials, and plastic materials. Specifically, in inorganic non-metallic systems, for example, papermaking cement, extruded cement, slag cement, ALC (lightweight cellular concrete), GRC (glass fiber reinforced concrete), pulp cement, wood chip cement, asbestos cement, calcium oxalate, Non-ceramic ceramic materials such as gypsum and gypsum slag, ceramic materials such as earthenware, ceramics, porcelain, setware, glass, and glazing. In a metal system, metal materials (metal steel plate), such as iron, aluminum, and copper, are mentioned, for example. In the wood system, for example, a single board, plywood, particle board, fiber board, laminated timber and the like made of cedar, straw, firewood, lauan, teak and the like can be mentioned. In the plastic system, for example, resin materials such as polypropylene, ABS resin, and phenol resin can be used. The shape of such an adherend is not particularly limited.

  In order to bond the adherend and the decorative sheet, for example, an adhesive can be used. Examples of the adhesive include polyvinyl acetate, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ionomer, butadiene / acrylonitrile rubber, neoprene rubber, natural rubber, and the like as active ingredients. Any known adhesive can be used.

  After joining the adherend and the decorative sheet, for example, according to the characteristics of the final product, cutting, use of a tenoner, sane processing, provision of V-shaped grooves, chamfering on four sides, and the like may be performed.

  The decorative material manufactured in this way includes, for example, interior materials for buildings such as walls, ceilings, and floors; surface decorative panels for furniture such as window frames, doors, and handrails; furniture; It can be used for a surface decorative board;

  The decorative sheet of the present invention is excellent in scratch resistance, interlayer adhesion and impact resistance because the first surface protective layer and the second surface protective layer are each formed from a resin composition containing the specific component.

It is a schematic diagram which illustrates the layer structure of the decorative sheet of this invention.

  The present invention will be specifically described below with reference to examples and comparative examples. However, the present invention is not limited to the examples.

Example 1
A primer layer was provided on the back surface of a base sheet made of a colored polypropylene (PP) film having a thickness of 60 μm. Next, a pattern layer was formed on the front surface of the base sheet by printing, and an adhesive layer was further formed on the pattern layer. A transparent polypropylene (PP) resin sheet having a thickness of 80 μm was laminated on the colorant layer by extrusion lamination to form a transparent resin layer. After the surface of the transparent resin layer is subjected to corona discharge treatment, a two-component curable urethane resin comprising an acrylic-urethane block polymer (main agent) and hexamethylene diisocyanate (curing agent) is formed on the transparent resin layer. A resin composition consisting of 100 parts by mass and 38 parts by mass of silica (average particle size 3 μm) was applied to form a primer layer having a thickness of 2 μm.

  The thickness (layer thickness) after curing of the resin composition (first surface protective layer-forming resin composition) that forms the first surface protective layer comprising the following components on the front surface of the primer layer is The thickness after curing a resin composition (second surface protective layer-forming resin composition) for forming a second surface protective layer comprising the components described below after coating by gravure coating so as to be 7 μm It was applied by a gravure coating method so that the (layer thickness) was 15 μm.

After coating the resin composition for forming the second surface protective layer, the second surface protective layer is applied by irradiating an electron beam under the conditions of an acceleration voltage of 175 keV and 5 Mrad using an electron beam irradiation apparatus in an environment having an oxygen concentration of 200 ppm or less. Cured. Next, the second surface protective layer side (front side) is heated with an infrared non-contact type heater to soften the base sheet and the transparent resin layer, and then immediately embossed by hot pressure to form a wood grain pattern. The decorative sheet was shaped to prepare a decorative sheet.
<Second surface protective layer forming resin composition>
-Bifunctional urethane acrylate (Tg = 25 (° C), weight average molecular weight 1500) 80 parts by mass-Hexafunctional urethane acrylate (Tg = 200 or more (° C), weight average molecular weight 1500) 20 parts by mass-Acrylic polyol (Tg = 100 (° C), weight average molecular weight 100,000) 40 parts by mass <first surface protective layer-forming resin composition>
・ Acrylic polyol (Tg = 100 (° C), weight average molecular weight 100,000) 100 parts by mass ・ Hexamethylene diisocyanate 15 parts by mass

Example 2
In the same manner as in Example 1, a back primer layer, a base sheet, a pattern layer, an adhesive layer, a transparent resin layer, and a primer layer were formed. Thereafter, a first surface protective layer-forming resin composition comprising the following components is applied to the front surface of the primer layer to a thickness of 7 μm by a gravure coating method, and then an environment with an oxygen concentration of 200 ppm or less. Below, an electron beam was irradiated using an electron beam irradiation device under the conditions of an acceleration voltage of 175 keV and 2 Mrad.

Then, the decorative sheet was produced by performing application | coating of 2nd surface protective layer formation resin composition, electron beam irradiation, and embossing like Example 1. FIG.
<First surface protective layer forming resin composition>
-Bifunctional urethane acrylate (Tg = 25 (° C), weight average molecular weight 1500) 80 parts by mass-Hexafunctional urethane acrylate (Tg = 200 or more (° C), weight average molecular weight 1500) 20 parts by mass-Hexamethylene diisocyanate 15 parts by mass

Example 3
A decorative sheet was prepared in the same manner as in Example 2 except that the components of the first surface protective layer-forming resin composition were the components described below.
<First surface protective layer forming resin composition>
-Bifunctional urethane acrylate (Tg = 25 (° C), weight average molecular weight 1500) 80 parts by mass-Hexafunctional urethane acrylate (Tg = 200 or more (° C), weight average molecular weight 1500) 20 parts by mass-Acrylic polyol (Tg = 100 (° C), weight average molecular weight 100,000) 40 parts by massHexamethylene diisocyanate 15 parts by mass

Example 4
A decorative sheet was prepared in the same manner as in Example 1 except that the content of the acrylic polyol contained in the second surface protective layer-forming resin composition was changed to 10 parts by mass instead of 40 parts by mass.

Example 5
A decorative sheet was prepared in the same manner as in Example 1 except that the content of the acrylic polyol contained in the second surface protective layer-forming resin composition was changed to 100 parts by mass instead of 40 parts by mass.

Example 6
The first surface protective layer-forming resin composition was applied to a thickness of 3 μm instead of 7 μm after curing, and the second surface protective layer-forming composition was changed to 17 μm instead of the cured thickness of 15 μm. A decorative sheet was produced in the same manner as in Example 1 except that coating was performed.

Example 7
The first surface protective layer-forming resin composition was applied to 10 μm instead of the cured thickness of 7 μm, and the second surface protective layer-forming resin composition was changed to 10 μm instead of the cured thickness of 15 μm. A decorative sheet was prepared in the same manner as in Example 1 except that coating was performed.

Example 8
Instead of the acrylic polyol (Tg = 100 (° C.), weight average molecular weight 100,000) contained in the first surface protective layer forming resin composition and the second surface protective layer forming resin composition, acrylic polyol (Tg = 90 (° C. ) And a weight average molecular weight of 80,000) were used in the same manner as in Example 1 to prepare a decorative sheet.

Comparative Examples 1-3
A decorative sheet was prepared in the same manner as in Example 1 except that the components in the second surface protective layer-forming resin composition were changed as shown in Table 1 below. In addition, the isocyanate of the 2nd surface protective layer forming resin composition in Table 1 means hexamethylene diisocyanate.

Comparative Examples 4-8
A decorative sheet was prepared in the same manner as in Example 2 except that the components in the first surface protective layer-forming resin composition and / or the second surface protective layer-forming resin composition were changed as described in Table 1 below. Produced. The resin having a hydroxyl group in the first surface protective layer-forming resin composition in Table 1 means acrylic polyol (Tg = 100 (° C.), weight average molecular weight 100,000), and the second surface in Table 1 The isocyanate of the protective layer-forming resin composition means hexamethylene diisocyanate.

Test method ≪Adhesion test (normal state) ≫
45 degrees after cellophane tape (cello tape (registered trademark), industrial 24 mm width, manufactured by Nichiban Co., Ltd.) is bonded to the second surface protective layer side (the front side of the decorative sheet) of the decorative sheet It peeled off vigorously at an angle of, and the decorative sheet and the cellophane tape were visually observed. The case where the interface between the first surface protective layer and the second surface protective layer was not peeled was evaluated as ◯, the portion where the surface was partially peeled was evaluated as Δ, and the case where the entire surface was peeled was evaluated as ×. ○ Only evaluation was accepted.

≪Adhesion test (after S-UV test) ≫
Using an ultra-accelerated weathering tester (“I Super UV Tester”, manufactured by Iwasaki Electric Co., Ltd.) (hereinafter referred to as S-UV), “Each decorative sheet was subjected to a temperature of 63 ° C. and a humidity of 50% RH. After irradiating light with an illuminance of 60 mW / cm ² (365 nm) for 20 hours and then condensing for 4 hours for 200 hours, the same evaluation as in the adhesion test (normal state) was performed. . ○ Only evaluation was accepted.

≪Hoffman scratch test≫
The test was conducted using a Hoffman scratch tester manufactured by BYK-GARDNER, USA. Specifically, an aqueous emulsion adhesive (Rikabond BA-10L (main agent): BA-11B (curing agent) manufactured by Chuo Rika Kogyo Co., Ltd.) = 100 on a medium density wood fiber board (MDF) of 2.7 mm. 2.5 (mass ratio)) was uniformly applied at 80 g / m ² , each decorative sheet was bonded, and each cosmetic material was prepared by curing at room temperature for 3 days. Scratch blades (φ7 cylindrical blades) were set so as to be in contact with the respective cosmetic material surfaces at an angle of 45 °, and the tester was moved on the cosmetic materials. The load (weight) was increased for the removal, and the test was repeated until a scratch impression was generated on the decorative sheet surface. A case where no scratch was observed at a load of 1000 g was evaluated as ◯, a case where a scratch was generated at a load of 500 g to 900 g, and a case where a scratch was generated at a load of 400 g or less were evaluated as x. ○ Only evaluation was accepted.

≪Impact resistance test (DuPont impact test) ≫
Water-based emulsion adhesive (Rikabond BA-10L (main agent): BA-11B (curing agent) = 100: 2.5 (mass ratio)) manufactured by Chuo Rika Kogyo Co., Ltd. on 2.7mm medium density wood fiberboard (MDF) Each decorative material was produced by uniformly coating at 80 g / m ² , pasting each decorative sheet, and curing at room temperature for 3 days. In accordance with JIS K5600 Tupon impact test, by placing a shooting die with a hemispherical tip with a radius of 6.3mm on each decorative material surface, and dropping a weight of 500g load from the height of 300mm onto the shooting die evaluated. The test was carried out 5 times, the case where no cracks could be observed on the surface of the decorative sheet was observed 5 times, the case where no cracks could be observed even once, the case where cracks were observed even once, and the case where all 5 times cracks were observed were evaluated as x. . ○ Only evaluation was accepted.

≪Processability test≫
The decorative sheets of Examples 1 to 3 were bent at room temperature (25 ° C.) and the change was evaluated by visual observation. The whitening was slight and the crack was not broken and was evaluated as ◎. The whitening was evaluated as ◯. ◎ and ○ were accepted.

≪Productivity≫
As productivity at the time of providing the surface protective layer of the decorative sheets of Examples 1 to 3, the case where the irradiation of ionizing radiation was performed once was evaluated as 、 ２, 2 times as ○, and 3 times or more as ×. ◎ and ○ were accepted.

1: Back primer layer 2: Substrate sheet 3: Pattern layer 4: Adhesive layer 5: Transparent resin layer 6: Primer layer 7: First surface protective layer 8: Second surface protective layer

Claims (7)

A decorative sheet having, in order, a first surface protective layer and a second surface protective layer on a substrate sheet,
(1) The first surface protective layer is formed from a resin composition containing a resin having an isocyanate and a hydroxyl group in the molecule, and the resin having the hydroxyl group in the molecule has a weight average molecular weight of 80,000 to 10000. Selected from the group consisting of polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol, polyurethane polyol, and copolymers formed by combining one or more of these. At least one,
(2) The second surface protective layer is formed of a resin composition having an ionizing radiation curable resin and a resin having a hydroxyl group in the molecule as a resin component, and the resin having the hydroxyl group in the molecule is a weight average. From a copolymer having a molecular weight of 80,000 to 100,000, polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol, polyurethane polyol, and a combination of one or more of these. At least one selected from the group consisting of:
A decorative sheet characterized by that. The decorative sheet according to claim 1, wherein the resin having the hydroxyl group in the molecule contained in the second surface protective layer is an acrylic polyol.   The decorative sheet according to claim 1 or 2, wherein the resin composition forming the second surface protective layer contains no isocyanate.   The decorative sheet according to any one of claims 1 to 3, wherein the ionizing radiation curable resin is an electron beam curable resin.   The decorative sheet according to any one of claims 1 to 4, comprising a pattern layer, a transparent resin layer, a primer layer, a first surface protective layer, and a second surface protective layer in this order on the base sheet.   The decorative sheet according to any one of claims 1 to 5, wherein the decorative sheet surface is embossed.   A decorative material obtained by bonding the base sheet side of the decorative sheet according to any one of claims 1 to 6 to an adherend.

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