JP2005238498A - Decorative sheet and decorative steel panel using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decorative sheet reduced in the amount to be used of VOC, having the high bleed suppressing effect of a weather-resistant agent and developing excellent stability with the elapse of time even if used under a high temperature or humidity environment. <P>SOLUTION: In the decorative sheet constituted by successively laminating a pattern layer, a transparent adhesive layer and a transparent polyester resin layer on a base material sheet comprising a polyolefinic resin or a polyester resin, at least one of those layers is formed of an aqueous composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a decorative sheet and a decorative steel sheet using the decorative sheet.

  As a decorative sheet used for the interior of buildings, surface decoration of fittings, interior of vehicles, etc., in general, an ink layer consisting of a base sheet, a solid ink layer and / or a pattern ink layer, an adhesive layer, a transparent resin layer, etc. Laminated composite sheets are known.

  In such a decorative sheet, the ink layer and the adhesive layer are conventionally formed from a solvent-based coating agent containing an aromatic solvent such as toluene and xylene, an aliphatic solvent such as methyl ethyl ketone and ethyl acetate (for example, , See Patent Document 1).

  All of the above-mentioned aromatic solvents and aliphatic solvents are organic volatile substances (VOC). In particular, aromatic solvents such as toluene and xylene are formulated as guidelines for PRTR-designated chemical substances and indoor air chemical substances. Listed as a substance. In addition, problems in the working environment due to volatilization of VOC contained in the solvent-based coating agent at the time of manufacturing the decorative sheet, environmental safety problems in which the residual VOC at the time of using the decorative sheet is diffused into a general living space, etc. have been pointed out. Yes. Therefore, reducing the amount of VOC used in the decorative sheet has become a recent issue.

Therefore, development of a decorative sheet with reduced VOC usage is desired. In addition, when the decorative sheet contains various weathering agents (ultraviolet absorbers, light stabilizers, etc.), the development of an easy-to-handle decorative sheet in which exudation of the weathering agent (so-called bleeding) is suppressed is also desired. Furthermore, there is a demand for the development of a decorative sheet that does not easily peel off, drop off, crack, or the like even when used in a high temperature / humidity environment such as a bathroom.
JP-A-11-198309

  The main object of the present invention is to provide a decorative sheet with reduced VOC usage.

  It is another object of the present invention to provide a decorative sheet that has a high bleed-inhibiting effect of a weathering agent and exhibits excellent temporal stability even when used in an environment with high temperature and humidity.

  As a result of intensive studies to achieve the above object, the present inventors have found that a specific decorative sheet can achieve the above object, and have completed the present invention.

That is, the present invention relates to the following decorative sheet.
1. A decorative sheet in which a pattern layer, a transparent adhesive layer, and a transparent polyester-based resin layer are sequentially laminated on a base sheet made of a polyolefin-based resin or a polyester-based resin, and a layer constituting the decorative sheet A decorative sheet, wherein at least one kind is formed from an aqueous composition.
2. Item 2. The decorative sheet according to Item 1, wherein the aqueous composition contains a basic neutralizing agent.
3. Item 3. The decorative sheet according to Item 1 or 2, wherein the basic neutralizing agent is at least one of a secondary amine, a tertiary amine, sodium hydroxide, potassium hydroxide, and ammonia.
4). Item 4. The decorative sheet according to any one of Items 1 to 3, wherein a colored concealing layer is further formed between the base sheet and the pattern layer.
5). Item 5. The decorative sheet according to any one of Items 1 to 4, wherein the polyester resin is polyethylene terephthalate or polybutylene terephthalate.
6). Item 6. The decorative sheet according to any one of Items 1 to 5, wherein a haze value of a resin constituting the transparent polyester resin layer is 5% or less.
7). Item 7. The decorative sheet according to any one of Items 1 to 6, wherein the transparent adhesive layer is formed from a heat sealing material or an ionizing radiation curable resin.
8). The decorative sheet according to any one of Items 1 to 7, wherein a transparent surface protective layer made of an ionizing radiation curable resin is further formed on the transparent polyester resin layer.
9. A decorative steel sheet obtained by attaching the base sheet side of the decorative sheet according to any one of Items 1 to 8 to a steel sheet via an adhesive containing a weathering agent.
10. Item 10. The decorative steel sheet according to Item 9, which is a bathroom decorative steel sheet.

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

  The decorative sheet of the present invention is a decorative sheet in which a pattern layer, a transparent adhesive layer, and a transparent polyester resin layer are sequentially laminated on a base sheet made of a polyolefin resin or a polyester resin, At least one of the layers constituting the decorative sheet is formed from an aqueous composition.

As the base sheet, a sheet made of polyolefin resin or polyester resin is used. Usually, a film made of these resins may be used.

  It does not specifically limit as polyolefin resin, What is normally used in the field | area of a decorative sheet can be used. For example, polyethylene, polypropylene, polybutene, polymethylpentene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-propylene-butene copolymer, polyolefin-based thermoplastic elastomer, etc. Is mentioned. Among these, polypropylene, polyolefin-based thermoplastic elastomers and the like are particularly preferable.

  A homopolymer or a copolymer mainly composed of polypropylene is also preferable, for example, a homopolypropylene resin, a random polypropylene resin, a block polypropylene resin, and a polypropylene crystal part, and an α-olefin having 2 to 20 carbon atoms other than propylene. Is mentioned. In addition, a propylene-α-olefin copolymer containing 15 mol% or more of a comonomer of ethylene, butene-1,4-methylpentene-1, hexene-1, or octene-1 is also preferable.

  The polyolefin-based thermoplastic elastomer is a block polymer using a highly crystalline and high melting point aromatic polyester for a hard segment and an amorphous polyether having a glass transition temperature of −70 ° C. or less for a soft segment. In particular, a mixture of a hard segment made of isotactic polypropylene and a soft segment made of atactic polypropylene at a weight ratio of 80:20 is preferable.

  The polyester resin is not particularly limited, and those usually used in the field of decorative sheets can be used. Examples thereof include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyarylate, polycarbonate, ethylene terephthalate-isophthalate copolymer, polyarylate and the like. Among these, polyethylene terephthalate, polybutylene terephthalate and the like are particularly preferable.

  As with polyester resins, in addition to various homopolymers, polyester resins, polyester resins, and polyester thermoplastic resins added with various copolymer components or modifying components for the purpose of softening the resin, etc. Etc. can be used. Specifically, in a condensation polymerization reaction of an aromatic dicarboxylic acid or dicarboxylic acid ester such as terephthalic acid or naphthalenedicarboxylic acid and an aliphatic diol such as ethylene glycol or 1,4-butanediol, as a dicarboxylic acid component, for example, Long chain aliphatic dicarboxylic acids and / or alicyclic dicarboxylic acids such as sebacic acid, eicoic acid, dodecanedioic acid, dimer acid, cyclohexanedicarboxylic acid, and / or polyethylene glycol, polytetra Preferred are those in which polyether diols having hydroxyl groups at both ends such as methylene glycol are introduced.

  The above-described polyolefin resin and polyester resin may be formed into a film by, for example, a calendar method, an inflation method, a T-die extrusion method, or the like.

  The thickness of the base sheet is not particularly limited and can be set according to product characteristics, but is usually 20 to 200 μm, preferably about 40 to 100 μm.

  An additive may be mix | blended with a base material sheet as needed. Examples of the additive include a filler such as calcium carbonate and clay, a flame retardant such as magnesium hydroxide, an antioxidant, a lubricant, a foaming agent, and a colorant (see below). The blending amount of the additive can be appropriately set according to the product characteristics.

  It does not specifically limit as a coloring agent, Well-known coloring agents, such as a pigment and dye, can be used. For example, titanium white, zinc white, petal, vermilion, ultramarine blue, cobalt blue, titanium yellow, yellow lead, carbon black and other inorganic pigments; isoindolinone, Hansa Yellow A, quinacridone, permanent red 4R, phthalocyanine blue, indanthrene Organic pigments (including dyes) such as blue RS and aniline black; metal pigments such as aluminum and brass; pearlescent pigments made of foil powder such as titanium dioxide-coated mica and basic lead carbonate. The coloring mode of the base sheet includes transparent coloring and opaque coloring (hiding coloring), and these can be arbitrarily selected. For example, when the ground color of the adherend (base material to which the decorative sheet is bonded) is concealed, opaque coloring may be selected. On the other hand, in order to make the ground pattern of the adherend visible, transparent coloring may be selected.

  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.

  A primer layer may be provided on one side or both sides of the base sheet as necessary. By providing the primer layer, interlayer adhesion with an adjacent layer (for example, an adherend) can be increased.

  A primer layer can be formed by apply | coating a well-known primer agent to the single side | surface or both surfaces of a base material sheet. As a primer agent, the aqueous composition which does not contain an organic solvent, especially an aqueous resin emulsion are preferable. For example, a urethane resin-based aqueous primer agent made of an acrylic-modified urethane resin or the like, specifically, an aqueous urethane resin emulsion using triisopropanolamine as a neutralizing agent.

The application amount of the primer agent is not particularly limited, but is usually 0.1 to 100 g / m ² , preferably about 0.1 to 50 g / m ² .

  Although the thickness of a primer layer is not specifically limited, Usually, 0.01-10 micrometers, Preferably it is about 0.1-1 micrometer.

A pattern layer is formed on the pattern layer base sheet (opposite to the adherend bonding surface).

  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.

  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 resins, styrene resins, polyester resins, urethane resins, chlorinated polyolefin resins, vinyl chloride-vinyl acetate copolymer resins, polyvinyl butyral resins, alkyd resins, 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.

  Among such colored inks, those composed of an aqueous composition (particularly an aqueous resin emulsion) are preferable. By using the aqueous composition, the amount of VOC used in the decorative sheet can be reduced.

  As the aqueous composition, an aqueous resin emulsion is preferable, for example, an aqueous urethane resin emulsion, an aqueous polyester resin emulsion, an aqueous acrylic resin emulsion, a cellulose resin emulsion, a shellac resin emulsion, a casein resin emulsion, a mixed emulsion of these, and a cross-linked to them. The emulsion etc. which mix | blended the component are mentioned.

  An aqueous emulsion having a crosslinking component introduced therein has, for example, an aqueous emulsion containing an amino group-containing aqueous compound as a main agent and an aqueous compound having two or more epoxy groups in one molecule as a crosslinking agent, and has an active hydrogen group. An aqueous emulsion containing an aqueous compound as a main component and an aqueous compound having two or more isocyanate groups in one molecule as a crosslinking agent, and an aqueous compound having a carboxyl group as a main component and having two or more carbodiimide groups in one molecule. And an aqueous emulsion containing the aqueous compound as a crosslinking agent.

  In the case of an aqueous composition comprising a resin emulsion, a basic neutralizing agent is preferably included. The basic neutralizing agent is not particularly limited as long as it can neutralize the carboxyl group in the resin by neutralization and disperse (emulsify) it in water. For example, secondary amine, tertiary amine, sodium hydroxide, hydroxide Preferred examples include potassium and ammonia. As a specific example, a secondary amine (for example, diethanolamine) can be used as a neutralizing agent in the nitrocellulose-based aqueous resin emulsion (ink).

  The same colorant as described above can also be used for a colored ink comprising such an aqueous composition (particularly an aqueous resin emulsion).

  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.

A colored concealment layer may be further formed between the colored concealment layer base sheet and the pattern layer, if 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. Of course, when the base sheet is transparent, even when the base sheet is concealed, it can be formed to stabilize the concealment.

  As the ink for forming the colored masking layer, an ink for forming a pattern layer and capable of masking coloring can be used. This ink is also preferably an aqueous composition (particularly an aqueous resin emulsion) and further preferably contains a basic neutralizing agent.

  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 appropriately set according to product characteristics. The layer thickness at the time of coating is about 0.1 to 10 μm, and the layer thickness after drying is about 0.05 to 5 μm.

Transparent adhesive layer A transparent adhesive layer is formed on the pattern layer. The transparent adhesive layer is not particularly limited as long as it is transparent, and includes any of transparent and colorless, colored and translucent. This adhesive layer is formed to bond the pattern layer and the transparent polyester resin layer.

It does not specifically limit as an adhesive agent, A well-known adhesive agent can be used in the field of a decorative sheet. Among these, what consists of an aqueous composition (especially aqueous resin emulsion) is preferable. Moreover, it is preferable that an aqueous composition contains a basic neutralizer. In addition, an ionizing radiation curable resin may be used as an adhesive, and a known film heat seal material may be used as an adhesive. Hereinafter, these adhesives will be described.
(Known adhesive)
Examples of the adhesive known in the field of decorative sheets include thermoplastic resins such as polyamide resin, acrylic resin and vinyl acetate resin, and curable resins such as thermosetting urethane resin. Further, a two-component curable polyurethane resin or polyester resin using isocyanate as a curing agent can also be applied.

  Among the above, an adhesive composed of an aqueous composition (particularly an aqueous resin emulsion) is particularly preferable. For example, an adhesive containing at least one of an aqueous urethane resin emulsion, an aqueous polyester resin emulsion, an aqueous acrylic resin emulsion, a cellulose resin emulsion and the like is preferable.

  The adhesive layer can be formed, for example, by applying an adhesive on the pattern layer, laminating a transparent polyester resin film constituting the transparent polyester resin layer, and drying and curing. Conditions such as drying temperature and drying time are not particularly limited, and may be set as appropriate according to the type of adhesive. The method of applying the adhesive is not particularly limited, and examples thereof include roll coating, curtain flow coating, wire bar coating, reverse coating, gravure coating, gravure reverse coating, air knife coating, kiss coating, blade coating, smooth coating, and comma coating. The method can be adopted.

Although the thickness of an adhesive bond layer is not specifically limited, The thickness after drying is 0.1-30 micrometers, Preferably it is about 1-20 micrometers.
(Adhesive layer made of ionizing radiation curable resin)
Although it does not specifically limit as ionizing radiation curable resin, For example, the composition which mixed the prepolymer, oligomer, and / or monomer which have a polymerizable unsaturated bond or an epoxy group in a molecule | numerator suitably is used. Examples of these resin systems include acrylates such as urethane acrylate, polyester acrylate, and epoxy acrylate, silicon resins such as siloxane, polyester, and epoxy. Examples of the prepolymer and oligomer include unsaturated polyesters and methacrylates. Examples of monomers include styrene monomers, acrylic esters, methacrylic esters, substituted amino alcohol esters of unsaturated acids, unsaturated carboxylic amides, and other monomers. . The above compounds are used singly or in combination of two or more. In order to impart ordinary coating suitability to the resin composition, the prepolymer or oligomer and / or monomer is mixed in an appropriate formulation.

  For example, the adhesive layer is formed by applying an ionizing radiation curable resin on the pattern layer, laminating a transparent polyester resin film constituting the transparent polyester resin layer, and then curing the ionizing radiation curable resin. It can be formed by irradiating radiation from above the transparent polyester resin layer. The application method of the ionizing radiation curable resin is the same as the above-described known adhesive application method.

  As the ionizing radiation, electromagnetic waves or charged particle beams having energy capable of polymerizing and crosslinking molecules can be used, and usually ultraviolet rays, electron beams, and the like can be used. The irradiation time of ionizing radiation can be appropriately set according to the type of ionizing radiation curable resin.

The thickness of the adhesive layer made of ionizing radiation curable resin is also the same as described above.
(Adhesive layer made of heat seal material)
The heat seal material (thermosetting resin) is not particularly limited. For example, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin Melamine-urea co-condensation resin, silicon resin, polysiloxane resin and the like. A curing agent such as a crosslinking agent and a resin initiator, a polymerization accelerator, a solvent, a viscosity modifier, an extender pigment, and the like may be added to these resins as necessary. As curing agents for unsaturated polyester resins, polyurethane resins and the like, isocyanates are preferred, amines are preferred as curing agents for epoxy resins, and peroxides such as methyl ethyl ketone peroxide are preferred as curing agents for unsaturated polyester resins. And radical initiators such as azobisisobutyronitrile are preferred.

  The adhesive layer can be formed by arranging a film-like heat seal material made of the above-mentioned thermosetting resin on the pattern layer, laminating a transparent polyester resin film thereon, and then heat-treating it. Although the heat processing temperature is not specifically limited, Usually, it is 80-180 degreeC, Preferably it is 100-180 degreeC. The heat treatment time is not particularly limited, but is usually about a moment (several seconds).

  The thickness of the adhesive layer made of the heat seal material is also the same as described above.

A transparent polyester resin layer is formed on the transparent polyester resin layer adhesive layer.

  The transparent polyester-based resin layer is a known polyester-based resin film and is not particularly limited as long as it is transparent, and includes any of colorless and transparent, colored and transparent, and translucent. About the kind of polyester-type resin, the film-forming method, etc., it is as having demonstrated with the item of the base material sheet. The resin constituting the transparent polyester resin layer is particularly preferably polyethylene terephthalate, polybutylene terephthalate, or the like.

  When the resin forming the transparent polyester-based resin layer has few impurities and excellent transparency, high definition is exhibited. The smaller the amount of impurities, the better. However, the haze value in the resin is usually 10% or less, preferably 5% or less. In addition, the haze value in this specification is the value measured based on prescription | regulation of JISK-7105.

  Although the thickness of a transparent polyester-type resin layer is not specifically limited, Usually, it is about 20-150 micrometers.

Transparent surface protective layer made of ionizing radiation curable resin On the transparent polyester resin layer, a transparent surface protective layer made of ionizing radiation curable resin may be further formed as necessary. By forming a surface protective layer made of an ionizing radiation curable resin, the abrasion resistance, impact resistance, stain resistance, scratch resistance, weather resistance, etc. of the decorative sheet can be improved.

  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. A transparent resin containing as a main component can be used. These prepolymers or monomers can be used alone or in combination. The curing reaction is usually a cross-linking curing reaction.

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

  Examples of the prepolymer having a radically polymerizable unsaturated group include polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, triazine (meth) acrylate, and silicone (meth) acrylate. Etc. These molecular weights are usually preferably about 250 to 100,000.

  As a monomer which has a radically polymerizable unsaturated group, methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenoxyethyl (meth) acrylate etc. are mentioned as a monofunctional monomer, for example. Examples of the polyfunctional monomer include diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide tri (meth) acrylate, dipentaerythritol tetra ( And (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

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

  As these ionizing radiation curable resins, an aqueous composition (particularly an aqueous resin emulsion) is preferable, and an aqueous resin emulsion containing a basic neutralizing agent is particularly preferable.

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

  As the ultraviolet light source, for example, a light source such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light, a metal halide lamp can be used. As a wavelength of ultraviolet rays, 190 to 380 nm is usually preferable.

  As the electron beam source, for example, various electron beam accelerators such as a cockcroft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type can be used. Among them, those capable of irradiating electrons having energy of 100 to 1000 keV, preferably 100 to 300 keV are preferable.

  The surface protective layer is formed by, for example, applying an ionizing radiation curable resin on a transparent polyester resin layer by a known coating method such as gravure coating or roll coating, and then irradiating the ionizing radiation to cure the resin. Can be formed.

  The thickness of the 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.

Weathering agent A weathering agent may be blended in at least one of the layers constituting the decorative sheet of the present invention, if necessary. As the weathering agent, an ultraviolet absorber, a hindered amine light stabilizer and the like are preferable. These weathering agents can be used alone or in admixture of two or more.
(UV absorber)
As the ultraviolet absorber, those having a basic component (particularly a hydroxyl group) are particularly preferable. For example, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) ) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-amyl-5'-isobutylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-isobutyl-5) 2'-hydroxyphenyl-5-chlorobenzo such as' -methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-isobutyl-5'-propylphenyl) -5-chlorobenzotriazole Triazole ultraviolet absorbers, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2′-hydroxy) 5'-methylphenyl) benzotriazole, 2'-hydroxyphenylbenzotriazole UV absorbers, such as benzotriazole UV absorbers, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'- 2,2′-dihydroxybenzophenone ultraviolet absorbers such as dihydroxy-4,4′-dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2, Benzophenone ultraviolet absorbers such as 2-dihydroxybenzophenone ultraviolet absorbers such as 4-dihydroxybenzophenone, and salicylic acid ester ultraviolet absorbers such as phenyl salicylate and 4-tert-butyl-phenyl-salicylate are used. In addition, a reactive ultraviolet absorber in which an acryloyl group or a methacryloyl group is introduced into the benzotriazole skeleton is also used. Of these, benzotriazole-based ultraviolet absorbers are particularly preferable. In addition, the addition amount of these ultraviolet absorbers is about 0.1-5 mass% normally with respect to a resin part.

  By adding such an ultraviolet absorber, the weather resistance of each layer can be enhanced. Moreover, when using the ultraviolet absorber containing a basic component, it interacts with the resin skeleton (carboxyl group) contained in the resin emulsion that can be used to form each layer, and the effect of suppressing bleeding of the ultraviolet absorber. Can also be obtained. For example, when an ultraviolet absorber having a hydroxyl group in the molecule is added to the base sheet and a urethane resin having an isocyanate group is used as a resin component constituting the adjacent layer, the ultraviolet absorbent bleeds from the base sheet. Even if it penetrates into the adjacent layer, it can be captured by the urethane bond between the hydroxyl group and the isocyanate group.

Although content of a ultraviolet absorber is not specifically limited, About 100-10000 weight ppm in each layer, Preferably it is about 500-7500 weight ppm. The layer to be added is not particularly limited, and can be appropriately set according to product characteristics.
(Hindered amine light stabilizer)
In order to further prevent deterioration of each layer due to ultraviolet rays and improve weather resistance, it is preferable to add a hindered amine light stabilizer as another weathering agent. For example, bis- (2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis- (N-methyl-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, etc. Examples thereof include compounds disclosed in Japanese Patent Publication No. 4-82625. The addition amount of these light stabilizers is not particularly limited, but is usually about 0.1 to 5% by weight with respect to the resin content.

  In addition, when adding a hindered amine light stabilizer, it is preferable from the point of a weather resistance improvement not to use resin containing a chlorine atom in the layer which comprises a base sheet and a decorative sheet. For example, if a resin containing a chlorine atom in the molecule, such as vinyl chloride-vinyl acetate copolymer or chlorinated polyolefin, is used as the binder resin, hydrogen chloride is generated from the chlorine-containing resin by the action of ultraviolet rays or heat. In this case, it reacts with the hindered amine light stabilizer to deactivate / inhibit its action, so that the effect of improving the weather resistance by the scavenger may not be sufficiently exhibited.

  When a hindered amine light stabilizer containing a basic component is included, the effect of suppressing bleeding of the ultraviolet absorber by interacting with the resin skeleton (carboxyl group) contained in the resin emulsion capable of forming each layer is also obtained. .

  Although content of a hindered amine light stabilizer is not specifically limited, About 100-10000 weight ppm in each layer, Preferably it is about 500-7500 weight ppm. The layer to be added is not particularly limited, and can be appropriately set according to product characteristics.

Cosmetic Material The decorative sheet of the present invention can be made into a cosmetic material by bonding with various adherends. 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.

  The shape of such an adherend is not particularly limited, and for example, shapes such as a flat plate, a curved plate, and a polygonal column can be arbitrarily adopted.

  The decorative material obtained by adhering the decorative sheet of the present invention to the surface of the adherend described above is, for example, a building interior material such as a wall or ceiling, a surface material of a fitting such as a door, door frame, or window frame, It can be used as a surface material for construction members such as rounded edges and skirting boards, and as a surface material for furniture such as bags and cabinets. Further, the decorative sheet itself can be used as a laminate material, a wrapping material or the like for the building material member without using an adherend. For example, the decorative sheet may be decorated by sticking the base sheet side of the decorative sheet to the surface of a steel sheet base used in a bathroom or the like.

  The adhesive used for laminating the adherend and the base sheet side of the decorative sheet is not particularly limited, and known adhesives in the field of decorative sheets can be used, and among them, particularly adhesives including weathering agents are used. preferable. Examples of the weathering agent include the aforementioned ultraviolet absorbers and light stabilizers.

  In the decorative sheet of the present invention, since at least one of the layers constituting the decorative sheet is composed of an aqueous composition, the amount of VOC used can be reduced. Moreover, even when a weathering agent is included, the bleed suppressing effect of the weathering agent is high.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to the examples.

Example 1
A polyolefin film having a thickness of 60 μm mainly composed of polypropylene and colored with a pigment was used as a base sheet, and both the front and back surfaces thereof were subjected to corona discharge treatment so that the surface tension on both the front and back surfaces was 48 dyn / cm or more. On the back surface of the base sheet, a back primer layer having a thickness of 2 μm made of a urethane resin emulsion using triisopropanolamine as a neutralizing agent was provided.

  A colored hiding layer (2 μm) and a pattern layer (3 μm) made of a polyether urethane resin emulsion using sodium hydroxide as a neutralizing agent were formed on the front surface of the base sheet. The coloring hiding layer and the pattern layer were formed by gravure printing.

Subsequently, a 60 μm thick transparent polyester resin film (haze 2%) blended with 500 ppm by weight of a hindered amine light stabilizer on the pattern layer is a two-part curable aqueous solution using sodium hydroxide as a neutralizing agent. Coating lamination was carried out through an adhesive layer (10 μm) composed of 10 g / m ^{2 of} polyester urethane.

  The adhesive was dried to prepare a decorative sheet.

The produced decorative sheet was heat treated at 120 ° C. for 10 minutes to remove the residual solvent and then subjected to gas chromatography. As a result, the residual VOC amount in the decorative sheet was 20 mg / m ² .

  The pencil hardness (measurement result in accordance with JIS-K5400) of 1 kg load on the front surface of the produced decorative sheet was HB.

  The produced decorative sheet was excellent in sharpness because the haze value of the transparent polyester resin film was as low as 2%, and was clearly visible when a fluorescent lamp emitting light was held over.

Example 2
A 60 μm thick polyester film containing polybutylene terephthalate as a main component and colored with a pigment was used as a base sheet, and both surfaces were subjected to corona discharge treatment so that the surface tension on both sides was 48 dyn / cm or more. On the back surface of the base sheet, a back primer layer having a thickness of 2 μm made of a urethane resin emulsion using triisopropanolamine as a neutralizing agent was provided.

  A colored hiding layer (2 μm) and a pattern layer (3 μm) made of a polyether urethane resin emulsion using sodium hydroxide as a neutralizing agent were formed on the front surface of the base sheet. The colored hiding layer and the pattern layer were formed by gravure printing.

Next, a transparent polyester resin film (hazy 2%) having a thickness of 60 μm blended with 500 wt ppm of a hindered amine light stabilizer on the pattern layer, containing 1000 wt ppm of benzotriazole UV absorber, and triisopropanolamine Was laminated through an adhesive layer (10 μm) composed of 10 g / m ² of a two-component curable aqueous polyurethane containing as a neutralizing agent.

Next, in order to further form a transparent surface protective layer made of an ionizing radiation curable resin on the transparent polyester resin layer, it contains 5000 ppm by weight of a benzotriazole-based ultraviolet absorber and triisopropanolamine as a neutralizing agent. A solution obtained by dissolving a 9: 1 (weight ratio) mixture of a bifunctional urethane oligomer and hexafunctional dipentaerythritol hexaacrylate in a mixture of water: isopropyl alcohol (IPA) = (weight ratio 7: 3) is 5 g / m ^2. Applied. Then, the ionizing radiation-curable resin was cured by irradiating an electron beam from the front surface at 175 eV and 5 Mrad, and a decorative sheet was produced.

  The pencil hardness of the produced decorative sheet front surface with a 1 kg load (measurement result in accordance with JIS-K5400) was 2H.

Comparative Example 1
In Example 1, the same composition as in Example 1 except that the solvent-based composition (commercial product) was used without forming the aqueous composition for forming each layer, and the haze of the transparent polyester resin film was 20%. A layered decorative sheet was prepared.

The produced decorative sheet was heat-treated at 120 ° C. for 10 minutes to remove the residual solvent and then subjected to gas chromatography. As a result, the residual VOC amount in the decorative sheet was 200 mg / m ² .

  Since the produced decorative sheet had a high haze value of 20% for the transparent polyester resin film, the sharpness was low, and when the fluorescent lamp was lit, the fluorescent lamp was greatly distorted.

Preparation of decorative steel sheet The base sheet side of the decorative sheet prepared in Examples and Comparative Examples was laminated on a plated steel sheet with an adhesive of 10 g / m ² to prepare three types of decorative steel sheets.

  As the adhesive, two types of two-component curable urethane-based adhesives containing triisopropanolamine as a neutralizing agent and those not containing 1000 ppm of benzotriazole-based ultraviolet absorbers were used.

  Table 1 below shows the type of adhesive used and the type of decorative steel sheet sample.

Test example 1
A weather resistance test was performed on each decorative steel sheet sample obtained above.

  The weather resistance was evaluated by using a carbon arc saddle type sunshine weather meter for 1000 hours under conditions of black panel temperature of 63 ° C and 18 minutes of rainfall for 120 minutes, then the front surface of each sample (opposite to the steel plate) The presence or absence of appearance changes such as discoloration, cracks in the sample, and peeling was visually observed with the naked eye.

  The weather resistance evaluation results are shown in Table 2 below.

2 is a conceptual diagram of a decorative sheet produced in Example 1. FIG. 6 is a conceptual diagram of a decorative sheet produced in Example 2. FIG.

Claims (10)

  A decorative sheet in which a pattern layer, a transparent adhesive layer, and a transparent polyester-based resin layer are sequentially laminated on a base sheet made of a polyolefin-based resin or a polyester-based resin, and a layer constituting the decorative sheet A decorative sheet, wherein at least one kind is formed from an aqueous composition.   The decorative sheet according to claim 1, wherein the aqueous composition contains a basic neutralizing agent.   The decorative sheet according to claim 1 or 2, wherein the basic neutralizing agent is at least one of a secondary amine, a tertiary amine, sodium hydroxide, potassium hydroxide and ammonia.   The decorative sheet according to any one of claims 1 to 3, wherein a colored concealment layer is further formed between the base sheet and the pattern layer.   The decorative sheet according to any one of claims 1 to 4, wherein the polyester resin is polyethylene terephthalate or polybutylene terephthalate.   The decorative sheet according to any one of claims 1 to 5, wherein the resin constituting the transparent polyester resin layer has a haze value of 5% or less.   The decorative sheet according to any one of claims 1 to 6, wherein the transparent adhesive layer is formed from a heat seal material or an ionizing radiation curable resin.   The decorative sheet according to any one of claims 1 to 7, wherein a transparent surface protective layer made of an ionizing radiation curable resin is further formed on the transparent polyester resin layer.   A decorative steel sheet obtained by attaching the base sheet side of the decorative sheet according to any one of claims 1 to 8 to a steel sheet via an adhesive containing a weathering agent. The decorative steel sheet according to claim 9, which is a decorative steel sheet for bathrooms.

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