JP5703659B2 - Decorative sheet - Google Patents

Description

  The present invention relates to a decorative sheet.

  A decorative sheet having a surface protective layer made of an ionizing radiation curable resin on the outermost surface is excellent in physical properties such as wear resistance, impact resistance, stain resistance, and scratch resistance, and is suitable as a sheet for flooring, for example. It is used for. Here, the ionizing radiation curable resin is appropriately blended with a prepolymer, an oligomer and / or a monomer containing a radical polymerizable double bond capable of undergoing a polymerization crosslinking reaction upon irradiation with ionizing radiation such as ultraviolet rays and electron beams. It will be. Such a decorative sheet is disclosed in Patent Document 1, for example.

JP 2002-52681 A

  However, since the decorative sheet described in Patent Document 1 still has insufficient scratch resistance, development of a decorative sheet having excellent scratch resistance is desired.

  For example, there is a method of improving the scratch resistance by increasing the thickness of the surface protective layer containing an ionizing radiation curable resin as compared with a conventional decorative sheet. However, when the thickness of the surface protective layer is increased (thickened), the solvent contained in the resin composition for forming the surface protective layer becomes difficult to dry, and as a result, the solvent is contained in the surface protective layer. There is a problem of remaining.

  Therefore, there is a method of coating a surface protective layer containing an ionizing radiation curable resin in multiple layers for the purpose of improving scratch resistance and solving the problem of the solvent. However, in the above 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 obtained between the surface protective layers, and peeling occurs between the surface protective layers during use.

  Accordingly, an object of the present invention is to provide a decorative sheet having excellent scratch resistance and excellent adhesion to a surface protective layer.

  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 it is formed with a specific layer structure, and has completed the present invention.

That is, the present invention relates to the following decorative sheet.
1. A decorative sheet having, in order, at least a first surface protective layer and a second surface protective layer on a base sheet,
(1) The first surface protective layer contains an ionizing radiation curable resin and an ionizing radiation non-curable resin having a hydroxyl group ,
(2) The decorative sheet, wherein the second surface protective layer contains an ionizing radiation curable resin and an isocyanate.
2 . Item 2. The decorative sheet according to Item 1, wherein the isocyanate is at least one selected from the group consisting of hexamethylene diisocyanate, isophorone diisocyanate, and xylylene diisocyanate.
3 . The ionizing radiation non-curable resin having a hydroxyl group is at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol, polyurethane polyol, and copolymers thereof. Item 3. A decorative sheet according to Item 1 or 2.
4). Item 4. The decorative sheet according to any one of Items 1 to 3, further comprising a pattern layer, a thermoplastic resin layer, a primer layer, a first surface protective layer, and a second surface protective layer in this order on the substrate sheet.

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

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 this order on a base sheet,
(1) The first surface protective layer contains an ionizing radiation curable resin and an ionizing radiation non-curable resin having a hydroxyl group ,
(2) The second surface protective layer contains an ionizing radiation curable resin and an isocyanate.

  The decorative sheet of the present invention having the above characteristics is excellent in scratch resistance and adhesion of the surface protective layer (first surface protective layer) because each of the first surface protective layer and the second surface protective layer satisfies the above specific conditions. And interlayer adhesion of the second surface protective layer).

  The configuration of the decorative sheet of the present invention is not limited, and may be any decorative sheet in which at least a first surface protective layer and a second surface protective layer are laminated on a base sheet. For example, a decorative sheet in which a pattern layer, a colored hiding layer, an adhesive layer, a thermoplastic resin layer, a primer layer, a first surface protective layer, and a second surface protective layer are sequentially laminated on a base material sheet can be used. Hereinafter, each layer constituting the decorative sheet will be described as a representative example.

(Base material sheet)
It does not specifically limit as a base material sheet, The thing normally used in the field | area of a decorative sheet can be used. For example, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, polybutene, polymethylpentene, polycarbonate, polyethylene naphthalate, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid Examples thereof include thermoplastic resins such as copolymers, ethylene-acrylic acid ester copolymers, ethylene-propylene-butene copolymers, ionomers, acrylic acid esters, methacrylic acid esters, and polyolefin-based thermoplastic elastomers. The said base material sheet can use these resin individually or in combination of 2 or more types.

  The base material sheet may be colored. In this case, it is possible to add a colorant (pigment or dye) to the above thermoplastic resin or the like 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.

  Although the thickness of a base material sheet can be suitably set with the use of a final product, a usage method, etc., generally 20-300 micrometers is preferable.

  One or both surfaces of the base sheet may be subjected to surface treatment such as corona discharge treatment, ozone treatment, plasma treatment, ionizing radiation treatment, dichromic acid treatment, etc., as necessary. For example, when the corona discharge treatment is performed, the surface tension of the substrate sheet surface may be 30 dyne or more, preferably 40 dyne or more. The surface treatment may be performed according to a conventional method for each treatment.

  The decorative sheet of the present invention may be provided with a primer layer (back surface primer layer) on the back surface side of the base material sheet as necessary. Although not shown, the decorative sheet of the present invention may be formed by laminating a polyester-based backer material on the back primer layer side of the base material sheet with an adhesive of an adhesive layer described later by a dry lamination method. When the back primer layer is not provided, a hard polyolefin backer material may be laminated on the back side of the base sheet by a melt extrusion lamination method or the like, and the back primer layer may be provided on the back side of the backer material.

  When a back surface primer layer is provided on the back surface side of the base material sheet, its material (including additives), coating method, coating amount, thickness, etc., are described later as a primer layer (a thermoplastic resin layer and a first surface protective layer). It is the same as the primer layer formed between.

(Pattern pattern layer)
A pattern layer can be formed on the substrate sheet as necessary.

  The design pattern layer imparts design properties with a desired design to the decorative sheet, and the type of design is not particularly 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, a colored ink or coating obtained by dissolving (or dispersing) a known colorant (dye or pigment) in a solvent (or dispersion medium) together with a binder resin. What is necessary is just to form by the printing method etc. which used the agent etc. As the ink, an aqueous composition can also be used from the viewpoint of reducing the VOC of the decorative sheet.

  Examples of the colorant include inorganic pigments such as carbon black, titanium white, zinc white, dial, bitumen, and 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.

  Examples of the binder resin include acrylic resin, styrene resin, polyester resin, urethane resin, chlorinated polyolefin resin, vinyl chloride-vinyl acetate copolymer resin, polyvinyl butyral resin, alkyd resin, petroleum Resin, ketone resin, epoxy resin, melamine resin, fluorine resin, silicone resin, fiber derivative, rubber resin and the like. These resins can be used alone or in admixture of two or more.

  Examples of the solvent (or dispersion medium) include petroleum organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and acetic acid-2 -Ester-based organic solvents such as ethoxyethyl; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone Organic solvents; ether organic solvents such as diethyl ether, dioxane, tetrahydrofuran; dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene Inorganic solvents and the like, such as water; chlorinated organic solvents. These solvents (or dispersion media) can be used alone or in admixture 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, for example, roll coating method, knife coating method, air knife coating method, die coating method, lip coating method, comma coating method, kiss coating method, flow coating method, dip coating Various coating methods such as a coating method may be mentioned. In addition, 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. may be used or combined with other forming methods. Good.

  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.

(Colored hiding layer)
A colored concealment layer may be further formed between the base sheet and the pattern layer as necessary. The colored masking layer is provided when it is desired to mask the ground color of the adherend from the front surface of the decorative sheet. In the present invention, the base sheet is colored, but a colored concealing layer may be further formed to stabilize the concealing property.

  As the ink for forming the coloring hiding layer, a known ink capable of hiding coloring can be used.

  The method for forming the colored concealment layer is preferably a method that can be formed so as to cover the entire base sheet (entirely solid). For example, the roll coating method, knife coating method, air knife coating method, die coating method, lip coating method, comma coating method, kiss coating method, flow coating method, dip coating method and the like described above are preferable.

  The thickness of the colored concealing layer is not particularly limited and can be set as appropriate according to the product characteristics. The layer thickness during coating is about 0.2 to 10 μm, and the layer thickness after drying is about 0.1 to 5 μm.

(Adhesive layer)
An adhesive layer may be formed in order to improve the adhesion between the thermoplastic resin layer and the pattern layer to be described later. The adhesive layer is not particularly limited as long as it does not impair the design properties, and includes any of colorless and transparent, colored and transparent, translucent and the like.

  It does not specifically limit as an adhesive agent, A well-known adhesive agent can be used in the field | area of a decorative sheet. Examples of known adhesives in the decorative sheet field include thermoplastic resins such as polyamide resins, acrylic resins and vinyl acetate resins, and thermosetting resins such as urethane resins. These adhesives can be 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.

  A well-known printing method can be employ | adopted for formation of an adhesive bond layer. For example, methods such as 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 can be employed.

  Although the thickness of an adhesive bond layer is not specifically limited, The thickness after drying is about 0.1-30 micrometers, Preferably it is about 1-20 micrometers.

(Thermoplastic resin layer)
A thermoplastic resin layer can be formed on the design pattern layer (or adhesive layer) as necessary.

  The resin constituting the thermoplastic resin layer is not particularly limited. For example, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid. Examples include ester copolymers, ionomers, polymethylpentene, acrylic acid esters, methacrylic acid esters, polycarbonates, and cellulose triacetates. These resins can be used alone or in combination of two or more.

  The method for forming the thermoplastic resin layer is not limited, for example, a method in which a preformed sheet or film is laminated to an adjacent layer, a resin composition that can form a thermoplastic resin layer is melt-extruded, and the thermoplastic resin layer is combined with the adjacent layer. There are methods such as laminating. Examples of the laminating method include a laminating method by a dry laminating method.

  Although the thickness of a thermoplastic resin layer is about 20-200 micrometers normally, it may exceed the said range according to the use etc. of a decorative sheet.

(Primer layer)
A primer layer can be formed between the thermoplastic resin layer and the first surface protective layer as necessary. By forming the primer layer, the adhesion between the thermoplastic resin layer and the first surface protective layer can be improved.

  The primer layer is made of vinyl chloride-vinyl acetate copolymer, acrylic resin, polyester resin, polyurethane-acrylic copolymer, polyurethane resin (two-component curing type consisting of isocyanate curing agent and various polyols), chlorinated polypropylene, chlorinated polyethylene. It is formed by applying a solution such as.

  In addition to the above resin, additives such as fillers such as silica fine powder, ultraviolet absorbers, and light stabilizers may be added to the primer layer. The primer layer is formed by applying these compositions and drying and curing as necessary. Specifically, it is formed by applying the primer composition by a method such as gravure coating or roll coating and drying (curing) it.

The coating amount of the primer layer is from 1 to 20 g / ^{m 2} (dry) are preferred, 1~5g / ^{m 2} (dry) is more preferable.

  Although the thickness of a primer layer is not specifically limited, Usually, 0.01-10 micrometers, Preferably it is about 1-4 micrometers.

  A patterned low gloss printing layer may be provided on the primer layer as necessary. After the first surface protective layer is applied, the region provided with the low gloss printing layer becomes less glossy than the other regions, and the design is recognized as if the region is a concave portion by the optical illusion. Become.

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

  The first surface protective layer contains at least an ionizing radiation curable resin as a resin component.

  The ionizing radiation curable resin is not particularly limited, and prepolymers (including oligomers) and / or monomers containing radically polymerizable double bonds capable of undergoing a crosslinking reaction upon irradiation with ionizing radiation such as ultraviolet rays and electron beams. Can be used. These prepolymers or monomers can be used alone or in combination.

  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 molecular weights are usually preferably about 250 to 100,000. For example, when the prepolymer having a radical polymerizable unsaturated group is urethane (meth) acrylate, it is a polyol component (acrylic polyol, polyester polyol, polyether polyol, epoxy polyol, polycaprolactone diol, etc.) and a curing agent component. To compounds having terminal isocyanate groups obtained by reacting isocyanate components (tolylene diisocyanate, hexamethylene diisocyanate, metaxylene diisocyanate, etc.), such as 2-hydroxyethyl acrylate (HEA) or 2-hydroxyethyl methacrylate (HEMA) By reacting an acrylate group, it is obtained as a bifunctional (meth) acrylate compound having an acryloyl group at both ends.

  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.

  When the decorative sheet of the present invention is used for bending, the first surface protective layer may be designed to be softer than the second surface protective layer. As a method of making the first surface protective layer softer than the second surface protective layer, in addition to the method of increasing the content of ionizing radiation non-curable resin added to the first surface protective layer, Those having a relatively small number of (meth) acrylate functional groups may be used.

  The first surface protective layer can further contain a resin having a hydroxyl group. By containing a resin having a hydroxyl group, it reacts with isocyanate contained in the second surface protective layer described later to form a urethane bond. Therefore, it becomes possible to further strengthen the adhesion between the first surface protective layer and the second surface protective layer.

  As the resin having a hydroxyl group, one having a hydroxyl group (—OH) 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. Resins having a hydroxyl group can be used alone or in combination of two or more.

  A preferred hydroxyl group-containing resin is at least one selected from the group consisting of acrylic polyol, polyurethane polyol and acrylic-urethane polyol.

  When the resin having a hydroxyl group is contained in the first surface protective layer, the content is not particularly limited, but is 1 to 95 parts by weight with respect to 100 parts by weight of the ionizing radiation curable resin contained in the first surface protective layer. Is preferred.

  In addition, you may use together resin which has groups containing active hydrogen, such as a carboxyl group, an amino group, and a mercapto group, for a 1st surface protective layer as needed. The group containing the active hydrogen can react with an isocyanate group in the same manner as the hydroxyl group. For example, thermosetting of unsaturated polyester resin, polyurethane resin, epoxy resin, amino alkyd resin, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, melamine-urea co-condensation resin, silicon resin, polysiloxane resin, etc. Can be mentioned.

  The first surface protective layer may be cured by irradiation with ionizing radiation before forming the second surface protective layer. As the ionizing radiation, 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 them, those capable of irradiating electrons having energy of 100 to 1000 keV, preferably 100 to 300 keV are preferable. The amount of electron beam irradiation is preferably about 2 to 15 Mrad, and more preferably 2 to 5 Mrad.

  The first surface protective layer may be formed of a weathering agent, a plasticizer, a stabilizer, a filler, a dispersant, a dye, a matting material, an ultraviolet absorber, a light stabilizer, a colorant such as a pigment, a solvent, etc. Various additives may be included.

  The first surface protective layer is formed by, for example, applying a resin composition containing an ionizing radiation curable resin on a thermoplastic resin layer by a known coating method such as gravure coating or roll coating, and then curing the resin. Can be formed.

  The 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 about 0.1 to 50 μm, preferably about 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 contains at least an ionizing radiation curable resin and an isocyanate. Therefore, the adhesion between the first surface protective layer and the second surface protective layer is improved. The reason why the adhesion is improved is understood to be that the isocyanate interacts with the ionizing radiation curable resin contained in the first surface protective layer. Further, by using an ionizing radiation curable resin, scratch resistance, impact resistance and the like can be improved together.

  The ionizing radiation curable resin is not particularly limited, and for example, a resin similar to the ionizing radiation curable resin exemplified in the first surface protective layer can be used.

  Similar to the first surface protective layer, a thermosetting resin or the like can be used as the resin component in addition to the ionizing radiation curable resin as the second surface protective layer.

  As the isocyanate, 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 (HDMI), isophorone diisocyanate (IPDI), hydrogenated tri-isocyanate Aliphatic (or alicyclic) isocyanates such as range isocyanate and hydrogenated diphenylmethane diisocyanate are used. Alternatively, adducts or multimers of the above various isocyanates can be used. For example, an adduct of tolylene diisocyanate, a tolylene diisocyanate trimer, 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 weight part is preferable with respect to 100 weight part of ionizing radiation-curable resins.

  In the second surface protective layer, the ionizing radiation curable resin contained as a resin component is crosslinked and cured by irradiation with ionizing radiation. Therefore, a decorative sheet excellent in scratch resistance, impact resistance and the like can be obtained.

  The type and conditions of the ionizing radiation are the same as the ionizing radiation in the first surface protective layer described above.

  If necessary, the second surface protective layer may be a weathering agent, a plasticizer, a stabilizer, a filler, a dispersant, a dye, a matting material, an ultraviolet absorber, a light stabilizer, a colorant such as a pigment, or a solvent. Various additives may be included.

  For example, the second surface protective layer is formed by applying a resin composition containing an ionizing radiation curable resin on the first surface protective layer by a known coating method such as gravure coating or roll coating, and then curing the resin. Can be formed.

  The 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, and more preferably about 1 to 5 μm. . In particular, when formed with a thin film of 1 to 20 μm, when the additive is contained, the additive is on the back surface side of the second surface protective layer (the first surface protective layer side viewed from the second surface protective layer). Since it can be present on the outermost layer side of the decorative sheet without sinking, the function of the additive can be effectively imparted as a result. For example, when the thickness of the second surface protective layer is 1 to 20 μm and matte silica is contained as an additive, design properties can be effectively imparted. The thinning of the second surface protective layer is also preferable from the viewpoint that an additive having a small particle diameter can be used as appropriate and from the viewpoint that the functionality can be effectively imparted by adding a small amount of the additive.

Manufacturing method of decorative sheet The decorative sheet of the present invention is obtained by forming the first protective surface layer and the second protective surface layer so that the second protective surface layer becomes the outermost surface. For example, after a pattern layer (and colored hiding layer), an adhesive layer, a thermoplastic resin layer, a primer layer and a first surface protective layer are laminated on a base sheet, a second surface protective layer is formed on the outermost surface. Can be obtained.

  The curing of the first surface protective layer can be performed after laminating all of the first surface protective layer and the second surface protective layer, but after forming the first surface protective layer, irradiating with ionizing radiation, It is preferable that the second surface protective layer is laminated on the cured first surface protective layer, and the second surface protective layer is cured by irradiating ionizing radiation again. By this method, the second surface protective layer can be efficiently laminated on the first surface protective layer.

  Moreover, when embossing of a decorative sheet is given, it may be after forming a 2nd surface protective layer, and may be before forming a 2nd surface protective layer. For example, as specific embodiments, 1) a pattern layer, a thermoplastic resin layer, a primer layer, a first surface protective layer and a second surface protective layer may be formed on a base sheet, and finally embossed Good. As another embodiment, 2) a pattern layer, a thermoplastic resin layer, a first primer layer, and a first surface protective layer are sequentially formed on the base sheet, and then embossed, and finally the second surface protection. A layer may be formed. As still another specific embodiment, 3) a pattern layer and a thermoplastic resin layer are formed in order on the base sheet, and then embossed, and then a first surface protective layer is provided. A surface protective layer may be formed.

For the embossing, a known embossed plate is used, and for example, the uneven pattern may be transferred to the pattern printing surface side of the decorative sheet at a sheet temperature of 120 to 160 ° C. and a pressure of 10 to 40 kg / cm ² .

  When performing wiping processing, as described in Japanese Patent Publication No. 58-14312, etc., after applying colored ink on the concavo-convex pattern, wiping is performed, and the concave portion of the concavo-convex pattern is filled with the colored ink. By doing.

Cosmetic Material A cosmetic material can be obtained by bonding the decorative sheet to various adherends so that the second surface protective layer of the decorative sheet of the present invention is the outermost surface. The material of the adherend is not particularly limited, and examples thereof include inorganic non-metallic materials, metallic materials, wood 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.

  Although it does not specifically limit about joining to the decorative sheet of this invention, and the said various to-be-adhered materials, For example, it can join via an adhesive agent. What is necessary is just to select an adhesive agent suitably from well-known adhesive agents according to the kind etc. of to-be-adhered material. Examples 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. These adhesives can be used alone or in combination of two or more.

  The decorative material manufactured in this way is, for example, interior decoration materials for buildings such as walls, ceilings and floors, surface decorative panels for furniture such as window frames, doors and handrails, furniture or cabinets for light electrical appliances, OA equipment, etc. It can be used for a surface decorative board.

  The decorative sheet of the present invention is excellent in scratch resistance because the first surface protective layer and the second surface protective layer each satisfy specific conditions, and the adhesion of the surface protective layer (the first surface protective layer and the second surface protective layer). Excellent interlayer adhesion).

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 pattern layer (thickness of about 1 to 3 μm) was formed on a 60 μm thick polypropylene resin (base sheet) by printing. Next, a polypropylene resin sheet was laminated on the pattern layer by an extrusion lamination method to form a thermoplastic resin layer having a thickness of 80 μm.

  A two-component curable urethane resin (polyurethane-acrylic copolymer) was formed on the front surface of the thermoplastic resin layer by gravure coating to form a primer layer.

  On the front surface of the primer layer, a urethane acrylate ionizing radiation curable resin (Seika Beam, manufactured by Dainichi Seika Co., Ltd.) was formed by gravure coating (thickness 15 μm), and then 175 keV and 5 Mrad ( The first surface protective layer was formed by irradiating an electron beam under the condition of 50 kGy).

  On the front surface of the first surface protective layer, 100 parts by weight of urethane acrylate ionizing radiation curable resin (Seika Beam, manufactured by Dainichi Seika Co., Ltd.) and hexamethylene diisocyanate (FG700, manufactured by DIC Graphics Co., Ltd.) 25 After forming a coating film (thickness: 15 μm) with a gravure coat of a resin composition consisting of parts by weight, a second surface protective layer is formed by irradiating an electron beam under the conditions of 175 keV and 5 Mrad (50 kGy). A decorative sheet was prepared.

Example 2
In the first surface protective layer, instead of the urethane acrylate ionizing radiation curable resin, 100 parts by weight of urethane acrylate ionizing radiation curable resin and 10 parts by weight of acrylic polyol (ACT, manufactured by DIC Graphics) are used. A decorative sheet was produced in the same manner as in Example 1 except that a coating film was formed using the resin composition.

Example 3
A decorative sheet was prepared in the same manner as in Example 2 except that the content of the acrylic polyol was 25 parts by weight instead of 10 parts by weight.

Example 4
A decorative sheet was produced in the same manner as in Example 2 except that the content of the acrylic polyol was changed to 40 parts by weight instead of 10 parts by weight.

Example 5
A decorative sheet was prepared in the same manner as in Example 1 except that the electron beam irradiation amount when forming the first surface protective layer was changed to 2 Mrad instead of 5 Mrad.

Example 6
A decorative sheet was produced in the same manner as in Example 4 except that the electron beam irradiation amount when forming the first surface protective layer was changed to 2 Mrad instead of 5 Mrad.

Comparative Example 1
A decorative sheet was prepared in the same manner as in Example 5 except that hexamethylene diisocyanate was not used.

Comparative Example 2
A decorative sheet was prepared in the same manner as in Comparative Example 1 except that the electron beam was not irradiated when forming the first surface protective layer.

Comparative Example 3
A decorative sheet was prepared in the same manner as in Example 1 except that hexamethylene diisocyanate was not used.

Test method ≪Adhesion test≫
Cellophane tape (cello tape (registered trademark), industrial 18 mm width, manufactured by Nichiban Co., Ltd.) is bonded to the second surface protective layer side of the decorative sheets obtained in Examples 1 to 6 and Comparative Examples 1 to 3. Then, it peeled off at an angle of 45 degrees, and the decorative sheet and the cellophane tape were visually observed. Regarding the decorative sheet, the case where there was no peeling at the interface between the first surface protective layer and the second surface protective layer was evaluated as ◯, and the case where there was peeling was evaluated as x.

In addition, the said adhesive test is a decorative sheet of the following (1)-(3):
(1) A decorative sheet after curing (temperature 40 ° C., 12 hours) on the decorative sheet immediately after production,
(2) Using a super accelerated weathering tester (“I Super UV Tester”, manufactured by Iwasaki Electric Co., Ltd.) (hereinafter referred to as S-UV) for a decorative sheet immediately after production, temperature 63 ° C. humidity 50% RH Under the circumstances, the decorative sheet after irradiating light having an illuminance of 60 mW / cm ² (365 nm) for 20 hours and then repeating the cycle of condensing for 4 hours for 50 hours,
(3) A decorative sheet after repeating the cycle in (2) for 100 hours,
Went against.
≪Scratch resistance test≫
(I) Hoffman Scratch Test The decorative sheets obtained in Examples 1-6 and Comparative Examples 1-3 were tested using a Hoffman scratch tester manufactured by BYK-GARDNER, USA. Specifically, a scratch blade (φ7 cylindrical blade) was set so as to be in contact with the decorative material surface at an angle of 45 °, and the tester was moved on the decorative material. The load (weight) was gradually increased, and the test was repeated until scratches, indentations and the like were generated on the decorative sheet surface. The maximum load (g) at which streaks, scars, disappearance of patterns, etc. occurred on the surface of the surface protective layer was indicated.
(Ii) Pencil hardness test The decorative sheets obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were tested using a pencil hardness tester. Specifically, when the tester is positioned horizontally, the test is performed in accordance with JIS K5600-5-4 except that the tester is set so as to apply a load of 1000 g to the tip of the pencil. It was. After the test, among the pencils in which no scratch was generated, the hardest pencil hardness was indicated.

  The test results are shown in Table 1 below. In Table 1, “not measurable” means that the adhesion between the first surface protective layer and the second surface protective layer is very weak, and is the minimum load that can be set in the Hoffman scratch test or the pencil hardness test. This also means that peeling (peeling between the first surface protective layer and the second surface protective layer) occurs.

Claims (4)

A decorative sheet having, in order, at least a first surface protective layer and a second surface protective layer on a base sheet,
(1) The first surface protective layer contains an ionizing radiation curable resin and an ionizing radiation non-curable resin having a hydroxyl group ,
(2) The decorative sheet, wherein the second surface protective layer contains an ionizing radiation curable resin and an isocyanate. The decorative sheet according to claim 1, wherein the isocyanate is at least one selected from the group consisting of hexamethylene diisocyanate, isophorone diisocyanate, and xylylene diisocyanate. The ionizing radiation non-curable resin having a hydroxyl group is at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol, polyurethane polyol, and copolymers thereof. The decorative sheet according to claim 1 or 2, wherein:   The decorative sheet according to any one of claims 1 to 3, comprising a pattern layer, a thermoplastic resin layer, a primer layer, a first surface protective layer, and a second surface protective layer in this order on the base sheet.

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