JP2009226724A - Decorative sheet and decorative laminate material using the decorative sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decorative sheet which can simultaneously meet requirements for the removal of an incrustation and fretting resistance as well as a decorative laminate material using the decorative sheet. <P>SOLUTION: The decorative sheet has a primer layer and a surface protecting layer laminated in that order, on one surface of a base material consisting of a polyester film, and a colored layer formed on the other surface of the base material. The surface protecting layer is formed of an ionizing radiation-curable resin composition which is cured through crosslinkage. And also, an ionizing radiation-curable resin component of the ionizing radiation-curable resin composition, is composed of at least, one kind of resin component which substantially does not contain a polymeric polymer with the number-average molecular weight more than 10,000 or more in terms of polystyrene, as measured by gel permeation chromatography (GPC), and is selected from the group consisting of a polymerizable monomer and a polymerizable oligomer with the number-average molecular weight of not more than 10,000 in terms of polystyrene as measured by gel permeation chromatography (GPC). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a decorative sheet, and more particularly, to a decorative sheet suitable as a surface material for a wall panel for a bathroom such as a unit bath, and a decorative board using the decorative sheet.

Conventionally, as a decorative sheet used for various furniture and building interior materials, the base material is printed using a normal method, and the surface of the printed layer is coated with amino alkyd resin, urethane resin, etc. A decorative sheet such as a decorative sheet in which a transparent biaxially stretched polyester film is laminated via an adhesive layer for surface protection after printing on a base sheet or a substrate is known. And the decorative board which laminated | stacked these decorative sheets on board | substrates, such as a galvanized steel plate, a plywood, or MDF, via the adhesive agent is known.
For example, Patent Document 1 discloses a decorative sheet in which a biaxially stretched polyester film is laminated as a surface protective layer.

  However, the surface protection by the polyester film has insufficient scratch resistance. Therefore, in order to improve the scratch resistance, Patent Document 2 proposes a decorative sheet in which a surface protective layer is obtained by crosslinking and curing an ionizing radiation curable resin composition.

JP 2005-119297 A JP 2007-204966 A

However, when the surface protective layer is obtained by crosslinking and curing the ionizing radiation curable resin composition, a problem has arisen that scale removability is reduced.
Accordingly, an object of the present invention is to provide a decorative sheet that satisfies both the descaling ability and the scratch resistance, and a decorative board using the decorative sheet.

  As a result of intensive research to achieve the above object, the present inventors have removed a high molecular weight polymer from the ionizing radiation curable resin component of the ionizing radiation curable resin composition used for the surface protective layer of the decorative sheet. It has been found that the above-mentioned problems can be solved by doing so. The present invention has been completed based on such findings.

That is, the present invention
(1) A decorative sheet in which a primer layer and a surface protective layer are laminated in this order on one surface of a substrate made of a polyester film, and a colored layer is formed on the other surface of the substrate, the surface protective layer being ionized The number of polystyrene equivalents obtained by crosslinking and curing the radiation curable resin composition, and the ionizing radiation curable resin component in the ionizing radiation curable resin composition measured by a polymerizable monomer and gel permeation chromatography (GPC). A decorative sheet comprising only at least one resin component selected from the group consisting of polymerizable oligomers having an average molecular weight of 10,000 or less,
(2) A decorative sheet in which a primer layer and a surface protective layer are laminated in this order on one surface of a substrate made of a polyester film, and a colored layer is formed on the other surface of the substrate, the surface protective layer being ionized The number of polystyrene equivalents obtained by crosslinking and curing the radiation curable resin composition, and the ionizing radiation curable resin component in the ionizing radiation curable resin composition being substantially measured by gel permeation chromatography (GPC). From a group consisting of a polymerizable oligomer that does not contain a high molecular weight polymer having an average molecular weight exceeding 10,000, and that has a polymerizable monomer and a polystyrene equivalent number average molecular weight measured by gel permeation chromatography (GPC) of 10,000 or less. A decorative sheet comprising at least one selected resin component;
(3) The decorative sheet according to (1) or (2), wherein the number average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) of the polymerized oligomer is 8,000 or less,
(4) The decorative sheet according to any one of (1) to (3), wherein the ionizing radiation curable resin composition is an electron beam curable resin composition,
(5) The decorative sheet according to any one of (1) to (4), wherein the elongation at break in the tensile test of the surface protective layer is 2.0% or more,
(6) The decorative sheet according to any one of (1) to (5), wherein the primer layer has a thickness of 0.5 to 20 μm,
(7) The decorative sheet according to any one of (1) to (6), wherein at least one surface of the substrate is subjected to an easy adhesion treatment,
(8) The decorative sheet according to any one of (1) to (7), wherein the substrate is a polyethylene terephthalate film,
(9) The decorative sheet according to any one of (1) to (8), wherein the primer layer contains a weather resistance improving agent,
(10) The decorative sheet according to any one of (1) to (9) above, wherein a resin layer made of polyester, polyolefin or polyvinyl chloride is further laminated on the surface of the colored layer via an adhesive layer,
(11) The decorative sheet according to any one of (1) to (10), wherein the decorative sheet is for bathroom wall material, unit bath wall material, or unit bath interior material.
(12) A decorative board in which the decorative sheet according to (11) is attached to a metal plate through an adhesive layer, and
(13) The decorative plate according to (12), wherein the metal plate is a steel plate.

  ADVANTAGE OF THE INVENTION According to this invention, the decorative sheet which satisfies scale removal property and abrasion resistance simultaneously, and the decorative board using this decorative sheet can be obtained. Furthermore, by setting the elongation at break in the tensile test of the surface protective layer of the decorative sheet within a predetermined range, a decorative sheet excellent in bending workability can be obtained.

In the decorative sheet of the present invention, a primer layer and a surface protective layer are laminated in this order on one surface of a substrate made of a polyester film, and a colored layer is formed on the other surface of the substrate.
The decorative sheet of the present invention will be described with reference to FIG. FIG. 1 is a schematic view showing a cross section of one embodiment of the decorative sheet 1 of the present invention. In the example shown in FIG. 1, a primer layer 3 and a surface protective layer 4 in which an ionizing radiation curable resin composition is crosslinked and cured are laminated in this order on a substrate 2, and a colored layer 5 is provided on the back side of the substrate 2. Yes.

The base material 2 used for the decorative sheet 1 of the present invention is made of a polyester film, and specifically includes a polyethylene terephthalate (PET) film, a polyethylene naphthalate film, a polybutylene terephthalate (PBT) film, and the like. -Considering smoothness and the like, a PET film, particularly a biaxially stretched PET film is preferable.
The polyester film used as the substrate 2 is subjected to a physical or chemical surface treatment such as an oxidation method or an unevenness method on one side or both sides as desired in order to improve the adhesion with the layer provided thereon. (Hereinafter referred to as “easy adhesion treatment”). In the present invention, it is preferable that at least one surface of the base material, particularly a surface on which a primer layer described later is laminated, be subjected to an easy adhesion treatment.
Examples of the oxidation method include corona discharge treatment, chromium oxidation treatment, flame treatment, hot air treatment, ozone / ultraviolet treatment method, and examples of the unevenness method include sand blast method and solvent treatment method. These surface treatments are appropriately selected depending on the type of substrate, but generally, a corona discharge treatment method is preferably used from the viewpoints of effects and operability.

  Although there is no restriction | limiting in particular about the thickness of the base material 2, The range of 15-100 micrometers is preferable. When it is 15 μm or more, the specularity is improved and a sense of depth of the design is obtained. On the other hand, workability improves that it is 100 micrometers or less. From the above points, the thickness of the substrate 2 is more preferably in the range of 20 to 50 μm.

The primer layer 3 shown in FIG. 1 is used for the purpose of improving the adhesion between the base material 2 and the surface protective layer 4, and at the same time, imparts sufficient weather resistance to the decorative sheet 1 of the present invention. It is also preferable to fulfill the function.
As the ink used for forming the primer layer 3, an ink in which an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, a curing agent and the like are appropriately mixed with a binder is used as necessary. The binder is not particularly limited, and examples thereof include ester resins, urethane resins, acrylic resins, urethane-acrylic copolymer resins, polycarbonate resins, vinyl chloride-vinyl acetate copolymers, polyvinyl butyral resins, and nitrocellulose resins. These resins can be used alone or in combination of two or more. There is no restriction | limiting in particular as a coating method of the primer layer 3, For example, 1 type, or 2 or more types of resin is used as a coating composition or an ink composition using a solvent etc., a roll coat method, a gravure printing method, etc. It is possible to form using any appropriate coating means.

In the resin composition which comprises the primer layer 3, it is preferable from the point which improves the weather resistance of the decorative sheet 1 to add a weather resistance improving agent. Examples of the weather resistance improver include an ultraviolet absorber (hereinafter sometimes referred to as “UVA”) and a light stabilizer (hereinafter sometimes referred to as “HALS”). The ultraviolet absorber (UVA) absorbs harmful ultraviolet rays and improves the long-term weather resistance and stability of the decorative sheet 1 of the present invention. In addition, the light stabilizer (HALS) itself absorbs little ultraviolet light, but stabilizes it by efficiently capturing harmful free radicals generated by ultraviolet energy.
These ultraviolet absorbers may be either inorganic or organic, and as the inorganic ultraviolet absorber, titanium dioxide, cerium oxide, zinc oxide or the like having an average particle diameter of about 5 to 120 nm can be preferably used. . Moreover, as an organic type ultraviolet absorber, benzotriazole type, for example, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-tert-) is specifically mentioned. Amylphenyl) benzotriazole, 3- [3- (benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl] propionic acid ester of polyethylene glycol, and triazines, specifically 2- ( 4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] phenol, 1,3,5-triazine-2,4,6 (1H, 3H, 5H)- And trione, 1,3,5-tri [[3,5-bis- (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] and the like.

  The ultraviolet absorber can be blended easily by kneading into a resin or the like constituting the primer layer 3 or by dissolving or dispersing the ultraviolet absorber in a solvent or the like and applying it to the primer layer 3. The ultraviolet absorber is preferably contained in the solid content of the primer layer 3 in the range of 6 to 15% by mass. When the content is 6% by mass or more, a sufficient ultraviolet absorption effect is obtained, and adhesion deterioration between the primer layer 3 and the base material 2 does not occur even in a weather resistance acceleration test or the like. Further, when the content is 15% by mass or less, the ultraviolet absorber does not bleed out. From the above points, the content of the ultraviolet absorber is particularly preferably in the range of 8 to 13%.

Next, examples of the light stabilizer include hindered amines, specifically 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2′-n-butylmalonate bis (1,2,2). 2,6,6-pentamethyl-4-piperidyl), bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate and the like. Moreover, as a commercial item, the product name "Tinubin 123" by Ciba Specialty Chemicals, etc. are mentioned.
In addition, as the ultraviolet absorber or light stabilizer, a reactive ultraviolet absorber or light stabilizer having a polymerizable group such as a (meth) acryloyl group in the molecule can be used.

  The thickness of the primer layer 3 is preferably in the range of 0.5 to 20 μm. If the thickness of the primer layer is 0.5 μm or more, sufficient adhesion between the substrate 2 and the surface protective layer 4 is obtained, and sufficient weather resistance is obtained. On the other hand, if the thickness of the primer layer 3 is 20 μm or less, it is preferable that cracking does not occur during processing. From the above points, the thickness of the primer layer is more preferably in the range of 1 to 20 μm, further preferably in the range of 1 to 10 μm, and particularly preferably in the range of 1 to 6 μm.

Next, the surface protective layer 4 is composed of a material obtained by crosslinking and curing the ionizing radiation curable resin composition as described above. Here, the ionizing radiation curable resin composition is one having an energy quantum capable of crosslinking and polymerizing molecules in an electromagnetic wave or a charged particle beam, that is, crosslinking or curing by irradiating ultraviolet rays or electron beams. Refers to a resin composition.
In the present invention, the ionizing radiation curable resin component in the ionizing radiation curable resin composition has a polystyrene equivalent number average molecular weight (Mn) measured by a polymerizable monomer and gel permeation chromatography (GPC) of 10,000 or less. It consists only of the at least 1 sort (s) of resin component chosen from the group which consists of this polymerizable oligomer. That is, the ionizing radiation curable resin component does not substantially contain a high molecular weight polymer having a polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) exceeding 10,000, and is a polymerizable monomer. And at least one resin component selected from the group consisting of polymerizable oligomers having a polystyrene equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of 10,000 or less. Is. By not having a polymer having a number average molecular weight (Mn) of more than 10,000 as an ionizing radiation curable resin component, it has become possible to greatly improve scale removal properties. From the viewpoint of improving scale removal properties, the number average molecular weight (Mn) of the polymerizable oligomer is more preferably 8,000 or less, and particularly preferably 7,000 or less. In the present invention, an oligomer refers to a multimer excluding a monomer and including a polymer having a number average molecular weight (Mn) of 10,000 or less from a dimer (dimer).

As the polymerizable monomer used in the ionizing radiation curable resin composition according to the present invention, typically, a (meth) acrylate-based monomer having a radical polymerizable unsaturated group in the molecule is suitable. (Meth) acrylate is preferred. Here, “(meth) acrylate” means “acrylate or methacrylate”. The polyfunctional (meth) acrylate is not particularly limited as long as it is a (meth) acrylate having two or more ethylenically unsaturated bonds in the molecule. Specifically, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) ) Acrylate, polyethylene glycol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified diphosphate ( (Meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylo Propane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris ( Acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene oxide modified dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate, etc. Is mentioned. These polyfunctional (meth) acrylates may be used singly or in combination of two or more.

In the present invention, a monofunctional (meth) acrylate can be used in combination with the polyfunctional (meth) acrylate as long as the object of the present invention is not impaired, for the purpose of lowering the viscosity. Examples of monofunctional (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl ( Examples include meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate. These monofunctional (meth) acrylates may be used alone or in combination of two or more, but preferably two or more bifunctional urethanes having different number average molecular weights (Mn). The acrylate is more preferably a combination of a bifunctional urethane acrylate having a number average molecular weight (Mn) of 1,000 to 3,000 and a bifunctional urethane acrylate having a molecular weight of 5,000 to 8,000.
Moreover, 5,000-8,000 bifunctional urethane acrylate is 50 mass% or less in an ionizing radiation-curable resin composition, Preferably it is good in it being 30 mass% or less.
A combination of two or more different bifunctional urethane acrylates described above, and a 5,000 to 8,000 bifunctional urethane acrylate within the above numerical range can provide a surface protective layer 4 with good scratch resistance. it can.

  Next, as the polymerizable oligomer, an oligomer having a radical polymerizable unsaturated group in the molecule, for example, epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, polyether (meth) acrylate And the like. Here, the epoxy (meth) acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it. . Further, a carboxyl-modified epoxy (meth) acrylate oligomer obtained by partially modifying this epoxy (meth) acrylate oligomer with a dibasic carboxylic acid anhydride can also be used. The urethane (meth) acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by reaction of polyether polyol or polyester polyol and polyisocyanate with (meth) acrylic acid. Examples of polyester (meth) acrylate oligomers include esterification of hydroxyl groups of polyester oligomers having hydroxyl groups at both ends obtained by condensation of polycarboxylic acid and polyhydric alcohol with (meth) acrylic acid, It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding an alkylene oxide to a carboxylic acid with (meth) acrylic acid. The polyether (meth) acrylate oligomer can be obtained by esterifying the hydroxyl group of the polyether polyol with (meth) acrylic acid.

  Furthermore, other polymerizable oligomers include polybutadiene (meth) acrylate oligomers with high hydrophobicity that have (meth) acrylate groups in the side chain of polybutadiene oligomers, and silicone (meth) acrylate oligomers that have polysiloxane bonds in the main chain. In a molecule such as an aminoplast resin (meth) acrylate oligomer modified with an aminoplast resin having many reactive groups in a small molecule, or a novolak epoxy resin, bisphenol epoxy resin, aliphatic vinyl ether, aromatic vinyl ether, etc. There are oligomers having a cationic polymerizable functional group.

  When an ultraviolet curable resin composition is used as the ionizing radiation curable resin composition, the photopolymerization initiator is about 0.1 to 10 parts by mass, preferably about 100 to 10 parts by mass, preferably 100 parts by mass of the ionizing radiation curable resin component. It is desirable to add 0.1 to 5 parts by mass. The initiator for photopolymerization can be appropriately selected from those conventionally used and is not particularly limited. For example, for a polymerizable monomer or polymerizable oligomer having a radically polymerizable unsaturated group in the molecule. Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2 -Phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propane-1 - 4- (2-hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4′-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2 -Tertiary butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, etc. It is done.

Examples of the polymerizable oligomer having a cationic polymerizable functional group in the molecule include aromatic sulfonium salts, aromatic diazonium salts, aromatic iodonium salts, metallocene compounds, and benzoin sulfonic acid esters.
Moreover, as a photosensitizer, p-dimethylbenzoic acid ester, tertiary amines, a thiol type sensitizer, etc. can be used, for example.
In the present invention, it is preferable to use an electron beam curable resin composition as the ionizing radiation curable resin composition. This is because the electron beam curable resin composition can be made solvent-free, is more preferable from the viewpoint of environment and health, and does not require a photopolymerization initiator and can provide stable curing characteristics.

Moreover, various additives can be mix | blended with the ionizing radiation-curable resin composition in this invention according to the desired physical property of the surface protective layer 4 obtained. Examples of this additive include a weather resistance improver, an abrasion resistance improver, a polymerization inhibitor, a crosslinking agent, an infrared absorber, an antistatic agent, an adhesion improver, a leveling agent, a thixotropic agent, a coupling agent, A plasticizer, an antifoamer, a filler, a solvent, a coloring agent, etc. are mentioned.
In particular, in order to improve the weather resistance of the decorative sheet 1 of the present invention, it is preferable to add a weather resistance improving agent to the ionizing radiation curable resin composition. The weather resistance improver is the same as the weather resistance improver that can be added to the resin composition constituting the primer layer 3.

  Examples of the wear resistance improver include fine particles of inorganic materials such as α-alumina, silica, kaolinite, iron oxide, diamond, and silicon carbide. Examples of the shape of the fine particles include a sphere, an ellipsoid, a polyhedron, a scale shape, and the like. Although there is no particular limitation, a spherical shape is preferable. Organic materials include synthetic resin beads such as cross-linked acrylic resin and polycarbonate resin. The particle size is usually about 30 to 200% of the film thickness. Among these, spherical α-alumina is particularly preferable because it has high hardness and a large effect on improving wear resistance, and it is relatively easy to obtain spherical fine particles.

Examples of the polymerization inhibitor include hydroquinone, p-benzoquinone, hydroquinone monomethyl ether, pyrogallol, t-butylcatechol, and the like, and examples of the crosslinking agent include a polyisocyanate compound, an epoxy compound, a metal chelate compound, an aziridine compound, and an oxazoline compound. Used.
As the filler, for example, barium sulfate, talc, clay, calcium carbonate, aluminum hydroxide and the like are used.
Examples of the colorant include known coloring pigments such as quinacridone red, isoindolinone yellow, phthalocyanine blue, phthalocyanine green, titanium oxide, and carbon black.
As the infrared absorber, for example, a dithiol metal complex, a phthalocyanine compound, a diimmonium compound, or the like is used.

  Moreover, an antibacterial agent can also be added to the ionizing radiation curable resin composition constituting the surface protective layer. As the antibacterial agent, commercially available industrial antibacterial agents can be used. Antibacterial agents include organic antibacterial agents and inorganic antibacterial agents. Inorganic antibacterial agents include some or all of ion-exchangeable ions such as zeolite, apatite, glass, silica gel, phosphate, and zirconium phosphate. There are ion exchangers in which are substituted with ions of silver, copper, zinc, tin, lead, mercury, cobalt, ammonium and the like. Among these, those obtained by substituting a part of ion-exchangeable ions of zeolite and zirconium phosphate with silver ions are desirable from the viewpoint of safety and actual product. The content of metal ions supported on zeolite and zirconium phosphate is preferably 0.1 to 15% by weight in the case of silver ions and 0.1 to 8% by weight in the case of copper or zinc ions. There are also those in which the ion exchanger substituted with the metal ions is further substituted with ammonium ions.

  Examples of the organic compounds having antibacterial properties include sulfa drugs such as p-aminobenzenesulfonamide, sulfathiazole, sulfapyridine and sulfapidiazine, dithiocarbamates such as dimethyldithiocarbamate and ethylenebisthiocarbamate, 2- (2-furyl) -3- (5-nitro-2-furyl) acrylamide and the like.

In the present invention, the above-mentioned ionizing radiation curable component polymerizable monomer, polymerizable oligomer and various additives are homogeneously mixed at a predetermined ratio to prepare a coating liquid comprising an ionizing radiation curable resin composition. To do. The viscosity of the coating solution is not particularly limited as long as it is a viscosity capable of forming an uncured resin layer on the surface of the substrate by a coating method described later.
In the present invention, the coating liquid prepared in this way is applied to the surface of the substrate so that the thickness after curing is 1 to 20 μm, gravure coating, bar coating, roll coating, reverse roll coating, Coating is performed by a known method such as comma coating, preferably gravure coating, to form an uncured resin layer. When the thickness after curing is 1 μm or more, a cured resin layer having a desired function is obtained. On the other hand, when the thickness after curing is 20 μm or less, it is preferable in that a crack does not occur during processing. The thickness of the surface protective layer 4 after curing is preferably about 2 to 20 μm.

In the present invention, the uncured resin layer thus formed is irradiated with ionizing radiation such as an electron beam and ultraviolet rays to cure the uncured resin layer. Here, when an electron beam is used as the ionizing radiation, the acceleration voltage can be appropriately selected according to the resin used and the thickness of the layer, but the uncured resin layer is usually cured at an acceleration voltage of about 70 to 300 kV. preferable.
In electron beam irradiation, the transmission capability increases as the acceleration voltage increases. Therefore, when using a base material that deteriorates due to the electron beam as the base material, the transmission depth of the electron beam and the thickness of the resin layer are substantially equal. By selecting the accelerating voltage so as to be equal to each other, it is possible to suppress the irradiation of the electron beam to the base material, and to minimize the deterioration of the base material due to the excessive electron beam.
Further, the irradiation dose is preferably an amount at which the crosslink density of the resin layer is saturated, and is usually selected in the range of 0.5 to 30 Mrad, preferably 1 to 5 Mrad.
Further, the electron beam source is not particularly limited. For example, various electron beam accelerators such as a cockroft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, a high frequency type, etc. Can be used.

When ultraviolet rays are used as the ionizing radiation, those containing ultraviolet rays having a wavelength of 190 to 380 nm are emitted. There is no restriction | limiting in particular as an ultraviolet-ray source, For example, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a carbon arc lamp, etc. are used.
The surface protective layer 4 thus formed is added with various additives to have various functions, for example, a so-called hard coat function, anti-fogging coat function, anti-fouling having high hardness and scratch resistance. A coating function, an antiglare coating function, an antireflection coating function, an ultraviolet shielding coating function, an infrared shielding coating function, and the like can also be imparted.

The surface protective layer 4 obtained as described above preferably has an elongation at break in a tensile test of 2.0% or more. Thereby, the bending workability of the decorative sheet 1 can be improved. In this respect, the elongation at break is more preferably 2.3% or more, and particularly preferably 2.5% or more. There is no upper limit to the elongation at break of the surface protective layer 4, and the higher the better, but since it is a cured resin layer, it is usually 10% or less.
Further, from the viewpoint of the same bending workability, the surface protective layer 4 preferably has a tensile strength in a tensile test of 25 MPa or more, more preferably 35 MPa or more, and particularly preferably 50 MPa or more. There is no upper limit to the tensile strength of the surface protective layer 4 and the higher the strength, the higher the toughness. However, since the cured resin layer is brittle, it is usually 200 MPa or less.

The colored layer 5 shown in FIG. 1 gives the base material 2 decorativeness and / or concealment and is composed of a pattern layer 5a and / or a solid colored layer 5b.
The pattern layer 5a is formed by printing various patterns using ink and a printing machine. The printing method is not particularly limited, and can be performed by a known method such as gravure printing, offset printing, or screen printing.
As patterns, there are stone patterns imitating the surface of rocks such as wood grain patterns, marble patterns (for example, travertine marble patterns), fabric patterns imitating cloth or cloth patterns, tiled patterns, brickwork patterns, etc. There are also patterns such as marquetry and patchwork that combine these. These patterns are formed by multicolor printing with the usual yellow, red, blue, and black process colors, as well as by multicolor printing with special colors prepared by preparing individual color plates constituting the pattern. Is done.
The solid colored layer 5b is a solid layer on the entire surface and functions as a concealing layer, but it also has a decorative property depending on the coloring. The solid colored layer 5b is formed by a printing method similar to the pattern layer 5a or a known coating method such as gravure coating, bar coating, roll coating, reverse roll coating, or comma coating.

As the ink used for the colored layer 5, an ink obtained by appropriately mixing a binder, a colorant such as a pigment or a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, or a curing agent is used. The binder is not particularly limited, and examples thereof include polyurethane resins, vinyl chloride / vinyl acetate copolymer resins, vinyl chloride / vinyl acetate / acrylic copolymer resins, chlorinated polypropylene resins, acrylic resins, and polyesters. Arbitrary resins, polyamide resins, butyral resins, polystyrene resins, nitrocellulose resins, cellulose acetate resins and the like may be used alone or in admixture of two or more.
Colorants include carbon black (black), iron black, titanium white, antimony white, yellow lead, titanium yellow, petal, ultramarine, cobalt blue and other inorganic pigments, quinacridone red, isoindolinone yellow, phthalocyanine blue, etc. Metal pigments composed of scaly foils such as organic pigments or dyes, aluminum, brass, pearlescent pigments composed of scaly foils such as titanium dioxide-coated mica and basic lead carbonate, and the like are used.

In addition, as shown in FIG. 2, the decorative sheet 1 of the present invention preferably further includes a resin layer 7 laminated on the surface of the colored layer 5 via an adhesive A layer 6. There is no restriction | limiting in particular as resin which comprises the resin layer 7, Although polyester, polyolefin, polyvinyl chloride, etc. are mentioned, Polyester and polyolefin are preferable when the environment at the time of disposal is considered.
Examples of the polyester used as the resin layer 7 include polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate. Examples of the polyolefin include polyethylene, polypropylene, polybutene, polymethylpentene, ethylene-propylene copolymer, and ethylene-propylene-butene copolymer. Polypropylene is preferable in consideration of processability and the like.

The resin layer 7 is preferably a plastic film made of the above-described resin, and the decorative sheet 1 is preferably bonded to the plastic film via an adhesive A layer 6 by dry lamination or the like.
Although it does not specifically limit as an adhesive agent which comprises the adhesive agent A layer 6, The adhesive agent for what is called dry lamination can be used conveniently. Specific examples include those that are cured with an isocyanate-based crosslinking agent or the like using a polyester-based resin or a polyether-based resin as a main component.

If desired, the resin layer 7 may be provided with a weather resistance improver, a polymerization inhibitor, an infrared absorber, an antistatic agent, an adhesion improver, a leveling agent, a thixotropic agent, a coupling agent, a plasticizer, and an antifoaming agent. , Fillers, flame retardants, colorants and the like can be added. In particular, it is preferable to add a colorant in order to obtain the concealability of the metal plate described in detail later.
Although there is no restriction | limiting in particular about the thickness of the resin layer 7, Usually, it is the range of 20-300 micrometers. When the thickness is 20 μm or more, a concealing property of a metal plate, which will be described in detail later, is sufficiently obtained, and when it is 300 μm or less, workability of secondary processing can be ensured. From the above points, the thickness of the resin layer 7 is more preferably in the range of 30 to 300 μm, further preferably in the range of 30 to 200 μm, and particularly preferably in the range of 45 to 200 μm.

In addition, as shown in FIG. 3, the present invention provides the metal plate 12 with the colored layer 5 of the decorative sheet 1 shown in FIG. 1 or the resin layer 7 of the decorative sheet 1 shown in FIG. A decorative board 10 affixed to is also provided. It does not specifically limit as an adhesive agent which comprises the adhesive agent B layer 11, An epoxy-type adhesive agent, a urethane type adhesive agent, a polyester-type adhesive agent etc. can be used conveniently.
As the metal plate 12, a normal steel plate can be used, and specifically, a hot rolled steel plate, a cold rolled steel plate, a hot dip galvanized steel plate, an electrogalvanized steel plate, a tin plated steel plate, a stainless steel plate and the like can be mentioned. An aluminum plate can also be used.

  The decorative sheet 1 and decorative plate 10 of the present invention can be used as decorative sheets for door materials, bathroom wall materials, unit bath wall materials, unit bath interior materials, kitchen wall materials, AV equipment, air conditioner covers, etc. In particular, it is suitably used as bathroom wall materials, unit bath wall materials, unit bath interior materials, etc. that require resistance to moisture and light.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by this example.
(Evaluation methods)
The decorative sheet obtained in each example was evaluated by the following methods.
(1) Tensile test After coating and curing the ionizing radiation curable resin composition to a thickness of 30 μm, it was pulled at a temperature of 25 ° C., a tensile speed of 50 mm / min, a test piece width of 10 mm, and a chuck distance of 80 mm. The elongation at the time of rupture was measured by the test, and the arithmetic average value of the values measured four times was defined as the elongation at break (%). In addition, the tensile strength (MPa) was measured, and the arithmetic average value of the values measured four times was defined as the tensile strength (MPa). In addition, the curing conditions (electron beam irradiation conditions) of the ionizing radiation curable resin composition are an acceleration voltage of 150 kV and an irradiation dose of 5 Mrad.
(2) Scale removal property It is 20 times to spray tap water on the surface protective layer side of the decorative sheets a and b manufactured in each Example and Comparative Example, which will be described later, and to dry in a 50 ° C. oven for 24 hours. Repeatedly deposit scale. The surface condition after wiping it with water-containing urethane sponge 1-2 times without applying force was evaluated according to the following criteria. The evaluation criteria are as follows.
◎: Appearance of water droplet traces is almost unnoticeable. Appearance: Water droplet traces do not remain in the ring state and occur on the surface of 1/4 or less. △: Water droplet traces do not remain in the ring state, and it is 1/2 or less. X: Water marks remain in a ring state (3) Scratch resistance The decorative sheets a and b produced in each Example and Comparative Example conform to JIS L0849 [Abrasion Tester Type II (Gakushin Type)] The test was conducted and evaluated according to the following criteria. The apparatus used for the test was a “Gakushin-type wear tester” manufactured by Tester Sangyo Co., Ltd., and evaluated using test pieces after 50 reciprocations with a load of 500 g using Kanakin No. 3 as a white cotton cloth for friction. The evaluation criteria are as follows.
◎: No scratches ○: No significant scratches on appearance △: Scratches or gloss change occurs on the surface of 1/4 to 1/2 of the test surface ×: Scratch or gloss change is 1/2 of the test surface Occurrence of the above (4) Bending workability The decorative board produced in each example and comparative example was subjected to a 90-degree bending test at a test temperature of 0 ± 1 ° C. and an inner radius of 1 mm in accordance with JIS K6744. Evaluation was performed according to the following criteria.
(Double-circle): The crack did not generate | occur | produce at all.
○: A fine crack occurred in the bent portion, but the design was not impaired.
X: A crack occurred.

Example 1
As the base material 2, double-sided easy adhesion treatment (polyester resin, baking treatment) PET (trade name “T600E-25N”, thickness 25 μm, manufactured by Toyobo Co., Ltd.) is used, and a urethane-acrylic copolymer resin (copolymer) is used on one side. An ink composition in which a polymerization ratio 5: 5) is used as a binder and triazine-based UVA 10 mass% (solid content conversion), HALS 3 mass% (solid content conversion) and silica 20 mass% (solid content conversion) are added as additives. The primer layer 3 was formed by applying a (full-surface solid) layer having a coating amount of 2 g / m ² by gravure printing. The thickness of the primer layer was 2 μm.
An abstract pattern using ink containing a colorant mainly composed of titanium oxide, quinacridone red, and isoindolinone yellow on the back surface of the substrate 2 (the side where the primer layer is not applied). The colored layer 5 was formed by gravure printing the pattern layer 5a and the solid colored layer 5b in that order.
On the primer layer 3, an electron composed of 80% by mass of a bifunctional urethane acrylate oligomer (number average molecular weight (Mn) 2,000) and 20% by mass of a bifunctional urethane acrylate oligomer (number average molecular weight (Mn) 6,000). An electron beam curable resin composition having a line curable resin component was applied at a coating amount of 5 g / m ² by a gravure offset coater method. After the coating, an electron beam with an acceleration voltage of 150 kV and an irradiation dose of 5 Mrad was irradiated to cure the electron beam curable resin composition, whereby the surface protective layer 4 was obtained. Next, curing was performed at 40 ° C. for 24 hours to obtain a decorative sheet a.
A PBT film having a thickness of 75 μm is bonded to the colored layer 5 side surface of the obtained decorative sheet a through an adhesive A layer 6 (thickness: 5 μm) that is cured with an isocyanate-based cross-linking agent based on a polyester polyol, A decorative sheet b was obtained by laminating as the resin layer 7.
Thereafter, the resin layer 7 side of the decorative sheet b was further adhered to a metal plate (hot dip galvanized steel plate, thickness 450 μm) through an adhesive B layer 11 (thickness 5 μm) having the same composition as the adhesive A layer 6. Table 1 shows the results of evaluation of the decorative sheets a and b and the decorative board by the evaluation method.

Example 2
The composition for forming the surface protective layer 4 is composed of 80% by mass of a bifunctional urethane acrylate oligomer (number average molecular weight (Mn) 2,000) and 20% by mass of a bifunctional urethane acrylate oligomer (number average molecular weight (Mn) 7,000). Cosmetic sheets a and b and a decorative board were obtained in the same manner as in Example 1 except that the composition was changed to an electron beam curable resin composition having an electron beam curable resin component. Table 1 shows the results of evaluation of the decorative sheets a and b and the decorative board by the evaluation method.

Comparative Example 1
In Example 1, a decorative sheet was obtained in the same manner as in Example 1 except that the electron beam curable resin composition forming the surface protective layer 4 was changed to a biaxially stretched PET film (thickness 25 μm). The biaxially stretched PET film was bonded to the substrate 2 via the primer layer 3. The obtained decorative sheets a and b and the decorative board were evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2
The composition for forming the surface protective layer 4 is a bifunctional urethane acrylate oligomer (number average molecular weight (Mn) 2,000) 56 mass%, a bifunctional urethane acrylate oligomer (number average molecular weight (Mn) 6,000) 14 mass%. A decorative sheet was prepared in the same manner as in Example 1 except that the composition was changed to an electron beam curable resin composition having an electron beam curable resin component consisting of 30% by mass of urethane acrylate polymer (number average molecular weight (Mn) 50,000). Obtained. Table 1 shows the results of evaluation of the obtained decorative sheets a and b and the decorative plate by the evaluation method.

  As is apparent from Table 1, according to the present invention, a decorative sheet that satisfies both the descaling property and the scratch resistance and a decorative board using the decorative sheet can be obtained, and the surface protective layer of the decorative sheet can be obtained. By making the elongation at break in the tensile test in a predetermined range, a decorative sheet excellent in bending workability and a decorative board using the decorative sheet can be obtained. This decorative sheet and decorative plate can be used as a decorative sheet or decorative plate for door materials, bathroom wall materials, unit bath wall materials, unit bath interior materials, kitchen wall goods, AV equipment, air conditioner covers, etc. In particular, it is suitably used as bathroom wall materials, unit bath wall materials, unit bath interior materials, etc. that require high descalability and scratch resistance.

It is a schematic diagram which shows the cross section of one embodiment of the decorative sheet of this invention. It is a schematic diagram which shows the cross section of the other embodiment of the decorative sheet of this invention. It is a schematic diagram which shows the cross section of the decorative board of this invention.

Explanation of symbols

1. Cosmetic sheet Base material 3. Primer layer 4. 4. Surface protective layer Colored layer 5a. Picture layer 5b. Solid colored layer 6. 6. Adhesive A layer Resin layer 10. Decorative plate 11. Adhesive B layer 12. Metal plate

Claims (13)

  A decorative sheet in which a primer layer and a surface protective layer are laminated in this order on one side of a base material made of a polyester film, and a colored layer is provided on the other side of the base material, the surface protective layer being ionizing radiation curable The resin composition has been crosslinked and cured, and the ionizing radiation curable resin component in the ionizing radiation curable resin composition has a polystyrene equivalent number average molecular weight measured by a polymerizable monomer and gel permeation chromatography (GPC). A decorative sheet comprising only at least one resin component selected from the group consisting of 10,000 or less polymerizable oligomers.   A decorative sheet in which a primer layer and a surface protective layer are laminated in this order on one side of a base material made of a polyester film, and a colored layer is provided on the other side of the base material, the surface protective layer being ionizing radiation curable The resin composition is crosslinked and cured, and the ionizing radiation curable resin component in the ionizing radiation curable resin composition has a polystyrene-reduced number average molecular weight substantially measured by gel permeation chromatography (GPC). The polymer was selected from the group consisting of polymerizable oligomers containing no high molecular weight polymer exceeding 10,000 and having a polystyrene equivalent number average molecular weight measured by gel permeation chromatography (GPC) of 10,000 or less. A decorative sheet comprising at least one resin component.   The decorative sheet according to claim 1 or 2, wherein the number average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) of the polymerized oligomer is 8,000 or less.   The decorative sheet according to any one of claims 1 to 3, wherein the ionizing radiation curable resin composition is an electron beam curable resin composition.   The decorative sheet according to any one of claims 1 to 4, wherein the elongation at break in a tensile test of the surface protective layer is 2.0% or more.   The decorative sheet according to any one of claims 1 to 5, wherein the primer layer has a thickness of 0.5 to 20 µm.   The decorative sheet according to any one of claims 1 to 6, wherein at least one surface of the substrate is subjected to easy adhesion treatment.   The decorative sheet according to any one of claims 1 to 7, wherein the substrate is a polyethylene terephthalate film.   The decorative sheet according to any one of claims 1 to 8, wherein the primer layer contains a weather resistance improving agent.   The decorative sheet according to any one of claims 1 to 9, wherein a resin layer made of polyester, polyolefin or polyvinyl chloride is further laminated on the surface of the colored layer via an adhesive layer.   The decorative sheet according to any one of claims 1 to 10, wherein the decorative sheet is for bathroom wall material, unit bath wall material, or unit bath interior material.   The decorative board which stuck the decorative sheet of Claim 11 to the metal plate through the adhesive bond layer.   The decorative plate according to claim 12, wherein the metal plate is a steel plate.

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