JP4482755B2 - Decorative sheet and method for producing the same - Google Patents

Description

  The present invention relates to a decorative sheet in which indoor air contamination by volatile organic compounds is reduced or eliminated, and a method for producing the same.

  The decorative sheet is used for covering the surface of various target articles (adhesive materials) and imparting an aesthetic appearance. There are many types of articles, but they are often used especially for interior and exterior buildings, furniture, household electrical appliances, kitchen furniture, and the like.

  The decorative sheet has various configurations depending on each application, but the concealability, durability (particularly wear resistance), flexibility, strength, etc. that can conceal the target article are constant for any application. It is desirable to be above the level.

  When polyvinyl chloride resin sheets were in wide use, decorative sheets were composed of polyvinyl chloride resin sheets, colored polyvinyl chloride sheets were printed to provide a pattern layer, and a transparent sheet was heat-sealed thereon In addition, an embossed two-layer sheet is often used as a decorative sheet. However, the plasticizer contained in the decorative sheet is decomposed at a high temperature during disposal, resulting in a harmful substance. For this reason, it has come to be replaced by a sheet of polyolefin resin typified by polypropylene resin, and improvements accompanying the replacement are also being promoted.

  On the other hand, in recent years, the problem of indoor air pollution has been raised, and various techniques for solving the problem have been studied.

  Under such circumstances, the surface of the decorative pattern provided on the base sheet made of polyolefin resin is made of at least an adhesive layer made of UV curable resin, made of transparent polyolefin resin by melt extrusion coating, and A decorative sheet characterized in that the surface of the transparent polyolefin-based resin layer has an uneven pattern has been proposed (for example, Patent Document 1).

  In addition, the base sheet of polyolefin resin or the like is an opaque colored sheet, and a pattern layer is formed using a water-based ink on the surface to be the front side of the base sheet. A decorative sheet in which an overlay layer is formed has also been proposed (for example, Patent Document 2).

However, these prior arts do not describe anything about solving the problem of indoor air contamination by volatile organic compounds (VOC). In fact, in any decorative sheet, there is still room for improvement in order to satisfactorily solve the problem of indoor air contamination by volatile organic compounds.
Japanese Patent Laid-Open No. 10-278197 (page 3, FIG. 1) JP 2001-38849 A (page 3, FIG. 1)

  The problem of volatile organic compounds can also be addressed by using quick-drying solvents. That is, by adopting a solvent that is extremely volatile, it is conceivable to volatilize the solvent from the coating film in the process of manufacturing the decorative sheet and reduce the residual solvent in the final product.

  However, when such a solvent having a high quick-drying property is used, a new problem arises that it becomes difficult to form a printed layer or the like because the ink is dried too quickly. Moreover, even if a printed layer can be formed, it is difficult to obtain a decorative sheet that can withstand practical use with a printed layer formed of such an ink.

  Therefore, the main object of the present invention is to produce a decorative sheet that can reduce or eliminate the problem of indoor air contamination by volatile organic compounds.

  As a result of intensive studies in view of the problems of the prior art, the present inventor can achieve the above object by forming a layer constituting a decorative sheet with a quick-drying composition using a solvent comprising a specific combination. As a result, the present invention has been completed.

  That is, this invention relates to the following decorative sheet and its manufacturing method.

1. A decorative sheet in which two or more layers are laminated on a base sheet,
At least one layer of said layer is at least 80 wt% of the solvent is isopropyl alcohol, ethyl acetate, Ri Do propylene glycol monomethyl ether and propyl acetate, total 100 weight of isopropyl alcohol, ethyl acetate, propylene glycol monomethyl ether and propyl acetate Isopropyl alcohol and ethyl acetate in total 70 parts by weight or more, propylene glycol monomethyl ether 2.5 parts by weight or more, propyl acetate 20 parts by weight or more, isopropyl alcohol and ethyl acetate in total 70 parts by weight or more of isopropyl alcohol are formed by the fast-drying composition which is a mixed solvent Ru 5-30 parts by der, decorative sheet, characterized in that.

  2. Item 2. The decorative sheet according to Item 1, wherein the decorative sheet is obtained by sequentially laminating at least a pattern layer, an adhesive layer, and a transparent sheet layer on a base sheet.

  3. Item 2. The decorative sheet according to Item 1, wherein the decorative sheet is obtained by sequentially laminating at least a pattern layer, an adhesive layer, a transparent sheet layer, and a protective layer on the base sheet.

  4). Item 4. The decorative sheet according to Item 2 or 3, wherein at least the pattern layer is formed of the quick-drying composition.

  5. Item 5. The decorative sheet according to any one of Items 2 to 4, wherein a primer layer is formed between the transparent sheet layer and the protective layer, and the protective layer is formed of an ionizing radiation curable resin.

  6). Item 6. The decorative sheet according to Item 5, wherein the primer layer and / or the protective layer is formed of the quick-drying composition.

7). Item 7. The decorative sheet according to any one of Items 1 to 6, wherein the quick-drying composition comprises 80% by weight or more of the mixed solvent and the remaining organic solvent having 5 or less carbon atoms.
8). Item 8. The organic solvent having 5 or less carbon atoms is at least one selected from the group consisting of methanol, ethanol, isobutanol, pentanol, acetone, methyl ethyl ketone, diethyl ketone, methyl acetate, and isopropyl acetate. Makeup sheet.
9 . A method for producing the decorative sheet according to any one of Items 1 to 8 ,
At least one of the layers, decorative sheet manufacturing method of which comprises a step of forming by the fast-drying composition of the layer.

  In the decorative sheet of the present invention, the layer is formed of a quick-drying composition containing isopropyl alcohol, ethyl acetate, propylene glycol monomethyl ether and propyl acetate as a part or all of the solvent. This problem can be reduced or eliminated. Moreover, despite using the quick-drying composition, it is possible to obtain a decorative sheet having properties equivalent to or higher than those of a layer formed from a conventional solvent-containing ink.

1. Configuration of the decorative sheet of the present invention The configuration of the decorative sheet of the present invention is not limited as long as it is a decorative sheet in which two or more layers are laminated on a base sheet. Any configuration of a known decorative sheet can be employed. For example, 1) a decorative sheet in which at least a pattern layer, an adhesive layer, and a transparent sheet layer are sequentially laminated on a base sheet; 2) at least a pattern layer, an adhesive layer, a transparent sheet layer, and a protective layer on the base sheet The decorative sheet etc. which were laminated | stacked in order are mentioned.

  Hereinafter, the configuration 2) will be described as a representative example. In FIG. 1, the laminated structure of a decorative sheet is shown. The decorative sheet 1 in FIG. 1 has a primer layer 2, a base sheet 3, a pattern layer 4, an adhesive layer 5, a transparent sheet layer 6, and a protective layer 7 laminated in order from the lower layer of the decorative sheet.

  The lowermost primer layer 2 is for improving the adhesiveness between the decorative sheet 1 and the adherend, and is an optional layer in the present invention. Moreover, you may give the unevenness | corrugation by embossing ranging from a top surface to a required layer as needed.

  As for the decorative sheet of this invention, a manufacturing procedure (lamination process) is not specifically limited. For example, when the base sheet 3 and the transparent sheet 6 are polyolefin resin sheets, the pattern layer 4 is formed by printing on the base sheet 3, and the adhesive layer 5 is formed on the pattern layer 4 by coating, and then bonded. The transparent sheet 6 may be laminated by melt extrusion onto the agent layer 5, and the protective layer 7 may be laminated by coating.

  In the present invention, at least one of the layers laminated on the base sheet 3 is a mixture in which part or all (preferably all) of the solvent is composed of isopropyl alcohol, ethyl acetate, propylene glycol monomethyl ether and propyl acetate. It is formed by a quick-drying composition (hereinafter also referred to as “the present invention composition”) which is a solvent (hereinafter also referred to as “the present invention mixed solvent”).

  The layer formed by the composition of the present invention is not limited, and can be appropriately selected depending on the configuration of the decorative sheet. In the embodiment, any one or more layers such as a pattern layer, an adhesive layer, and a protective layer may be formed from the composition of the present invention. Furthermore, for example, when the protective layer is formed of an ionizing radiation curable resin or the like, a primer layer (EB primer layer) can also be formed as the base. And this invention composition can be used also for formation of a primer layer.

  In any configuration, in the present invention, it is desirable that at least the pattern layer is formed of the composition of the present invention. Thereby, the problem of VOC and the problem of printing characteristics can be improved at once.

  The composition of the present invention is a quick-drying composition in which a part or all of the solvent (preferably all of the solvent) is a mixed solvent composed of isopropyl alcohol (IPA), ethyl acetate, propylene glycol monomethyl ether (PGM) and propyl acetate. is there. By forming at least one of the respective layers using a composition having such a combination of solvents, it is possible to solve the VOC problem and obtain a layer having excellent coating properties.

  The content ratio of the mixed solvent of the present invention can be appropriately set according to the desired printing characteristics, etc., but especially isopropyl alcohol and isopropyl alcohol with respect to a total of 100 parts by weight of isopropyl alcohol, ethyl acetate, propylene glycol monomethyl ether and propyl acetate. 60 parts by weight or more of ethyl acetate (more than 70 parts by weight), 2.5 parts by weight of propylene glycol monomethyl ether (more than 5 parts by weight), 20 parts by weight of propyl acetate (more than 25 parts by weight) It is preferable to include the above.

  The ratio of isopropyl alcohol to ethyl acetate is not limited, but isopropyl alcohol is preferably 5 to 30 parts by weight (particularly 10 to 20 parts by weight) out of the 70 parts by weight.

  In the present invention, when the mixed solvent of the present invention is used as a part of the solvent, the ratio of the mixed solvent of the present invention in the total solvent may be appropriately set within the range of usually 80% by weight or more and less than 100% by weight. In this case, it is desirable to use an organic solvent having 5 or less carbon atoms as the remaining solvent. Thereby, the problem of VOC can be avoided more reliably.

  The organic solvent having 5 or less carbon atoms (1 to 5 carbon atoms) may be any organic solvent other than those used in the mixed solvent of the present invention. For example, alcohols such as methanol, ethanol, isobutanol and pentanol (particularly, Aliphatic alcohols); ketones such as acetone, methyl ethyl ketone, and diethyl ketone; and carboxylic acid esters of methyl acetate and isopropyl acetate. These organic solvents can be used alone or in combination of two or more.

  The solid content in the composition of the present invention is not limited, and can be appropriately set according to the composition of the mixed solvent of the present invention, the type of solid content (resin etc.), desired characteristics, and the like.

2. Each layer which comprises the decorative sheet of this invention Each layer which comprises the decorative sheet 1 of this invention is demonstrated in order according to FIG.

The primer layer 2 on the lowermost surface of the primer layer can be provided as necessary in order to improve the adhesion between the decorative sheet 1 and the adherend.

  The material for forming the primer layer 2 is not limited, and the same material as the primer layer of a known decorative sheet can be used. For example, a polyester resin, a polyurethane resin, an acrylic resin, a polycarbonate resin, a vinyl chloride / vinyl acetate copolymer, a polyvinyl butyral resin, a nitrocellulose resin, or the like can be used alone or in combination.

  The formation method of a primer layer is not limited, What is necessary is just to follow a well-known method. For example, a resin solution or a resin emulsion obtained by dissolving or dispersing the above resin in an appropriate solvent may be used and formed using a known coating or printing means.

  In the present invention, it is desirable to use either 1) water or an aqueous solvent, 2) the mixed solvent of the present invention, or 3) the above-mentioned solvent having 5 or less carbon atoms as the solvent. Thereby, it can contribute to prevention of indoor air pollution effectively.

  As the aqueous solvent, a mixed solvent of water and a water-soluble organic solvent can be used. A well-known thing can be used for a water-soluble organic solvent. Examples thereof include alcohols such as ethanol and isopropyl alcohol, glycols, glycol ethers, and the like.

  The primer layer may be formed at any stage. For example, 1) the primer layer 2 is laminated on the base material sheet 3 in a state where nothing is laminated, and 2) the primer layer 2 is laminated after laminating each layer including the transparent sheet 6 on the base material sheet 3. 3) The primer layer 2 can be laminated after laminating each layer including the protective layer 7 on the substrate sheet 3. Moreover, it can also laminate | stack in steps other than these.

Substrate sheet base sheet 3, but any material used in the known decorative sheet can be used. Examples thereof include papers, plastics, metals (or alloys), and composite materials thereof. What is necessary is just to use these materials with forms, such as a sheet | seat and foil. Among these, it is easy to impart aesthetics by printing or painting, and it is excellent in processability when manufacturing a decorative sheet or processability (for example, bending, molding) when applying a decorative sheet to the surface of a target article. In terms of plastics.

  Examples of plastics include polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, vinyl chloride-vinyl acetate copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene-vinyl alcohol copolymer resin. Polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate-isophthalate copolymer resin, polymethyl methacrylate resin, polyethyl methacrylate resin, polybutyl acrylate resin, polyamide resin (nylon 6, nylon 66, etc.), three Cellulose acetate resin, cellophane, polystyrene resin, polycarbonate resin, polyarylate resin, polyimide resin and the like can be used. Among the above plastics, it is desirable to use a polyolefin-based resin that does not cause harmful substances.

  More specifically, there are two types of polyolefin-based resins: non-elastomer polyolefin-based resins and polyolefin-based thermoplastic elastomers.

  Specific examples of the non-elastomer include polyethylene (low density, medium density or high density), polypropylene (isotactic type, syndiotactic type, mixed type thereof), polymethylpentene, polybutene, and ethylene / propylene. Examples thereof include highly crystalline materials such as copolymers and propylene / butene copolymers.

  Examples of the latter elastomer include the following (1) to (8).

(1) The main raw material is composed of highly crystalline high-density polyethylene or isotactic polypropylene whose hard segment is a hard segment, and further added with an elastomer as a soft segment and, if necessary, an inorganic filler, etc. For example, diene rubber, hydrogenated diene rubber, olefin elastomer and the like are used. Examples of the diene rubber include isoprene rubber, butadiene rubber, butyl rubber, propylene / butadiene rubber, acrylonitrile / butadiene rubber, acrylonitrile / isoprene rubber, and styrene / butadiene rubber. The hydrogenated diene rubber is obtained by adding a hydrogen atom to at least a part of the double bond of the diene rubber molecule, and suppresses crystallization of a polyolefin resin (in the present invention, high-density polyethylene or polypropylene). , With improved flexibility. The olefin elastomer is an elastic copolymer obtained by adding at least one polyene copolymerizable with two or three or more olefins. As the olefin, ethylene, propylene, α-olefin and the like are used, and as the polyene, 1,4-hexadiene, cyclic diene, norbornene and the like are used. Examples of preferable olefin copolymer rubber include elastic copolymers mainly composed of olefin such as ethylene / propylene copolymer rubber. In addition, you may bridge | crosslink these elastomers in an appropriate amount using crosslinking agents, such as an organic peroxide and sulfur, as needed.

(2) The hard segment is isotactic polypropylene and the soft segment is atactic polypropylene, preferably the latter proportion is less than 5% by weight (described in Japanese Patent Publication No. 6-23278)
(3) A copolymer of ethylene / propylene / butene, which contains one of three structural isomers of 1-butene, 2-butene or isobutylene as butene. The following (3a) to (3c) Representative.

  (3a) A ternary random copolymer of ethylene / propylene / butene, wherein propylene in the monomer is preferably 90% by weight (described in JP-A-9-1111055).

  (3b) A propylene component content of 50% by weight or more, consisting of an amorphous copolymer of ethylene / propylene / butene and a crystalline polypropylene (described in JP-A-5-77371) .

  (3c) A low crystalline material having a propylene and / or 1-butene content of 50% by weight or more, a crystalline polyolefin such as isotactic polypropylene, and further containing 0.5% by weight of an oil gelling agent (Described in JP-A-7-316358).

(4) The hard segment is a crystalline material such as polyethylene, polypropylene or polymethylpentene, and the soft segment is a monoolefin copolymer rubber such as a partially crosslinked ethylene / propylene non-conjugated diene terpolymer rubber ( (Described in Japanese Patent Publication No. 53-21021)
(5) An olefin copolymer (crystalline) as a hard segment and an uncrosslinked monoolefin copolymer rubber as a soft segment are partially crosslinked by applying shear stress while heating (Japanese Patent Publication No. 53- No. 34210)
(6) Peroxide-decomposable olefin polymer, whose molecular weight decreases and fluidity increases when mixed and heated with a peroxide, such as isotactic polypropylene, propylene / ethylene copolymer, or propylene / butene-1 copolymer Peroxide-crosslinked monoolefin polymers, such as ethylene / propylene copolymer rubber, ethylene / propylene / non-conjugated diene terpolymer rubber, etc., which have a polymer as a hard segment and whose fluidity is reduced by the same operation, are soft. A segment obtained by mixing and heating a peroxide non-crosslinked hydrocarbon rubber that does not crosslink in the same operation and does not change fluidity in the presence of peroxide (Japanese Examined Patent Publication 56- 15741)
(7) Ethylene / styrene / butadiene copolymer (described in JP-A-2-139232)
(8) Olefin-based elastomers of the above (1) to (7) having a hydroxyl group or a carboxyl group The above-mentioned polyolefin-based resins may be those added with at least one of an ultraviolet absorber and a light stabilizer. preferable. These ultraviolet absorbers and light stabilizers may be known or commercially available.

  The base material sheet 3 can also be colored with a known colorant for the purpose of improving the concealing property when attached to the adherend, the purpose of improving the appearance of the pattern applied to the decorative sheet, and the like.

  Examples of the colorant include inorganic pigments such as carbon black, petal, yellow lead, ultramarine, and titanium white; organic pigments such as quinacridone red, isoindolinone yellow, and phthalocyanine blue; aluminum, brass, titanium dioxide-coated mica, and the like. A bright pigment made of a scale-like foil piece can be used. In addition, various dyes can also be used. These can be used alone or in combination of two or more.

  Moreover, a filler can also be mix | blended with a base material sheet. For example, calcium carbonate, barium sulfate, aluminum hydroxide, magnesium hydroxide, talc, kaolinite and the like can be used. These can be used alone or in combination of two or more.

  The thickness of the base sheet 3 is generally about 20 μm to 150 μm, but may exceed the above range depending on the use of the decorative sheet.

Pattern layer Pattern layer 4 is for imparting a design appearance or the like to the decorative sheet. Therefore, the pattern layer 4 may be used alone or in combination as appropriate depending on the purpose and application of the decorative sheet.

  In general, the pattern layer can be suitably formed by a printing method using printing ink. As the printing method, the gravure printing method is suitable in terms of a wide binder selection range, but other printing methods may be used. In addition to the printing method, an electrophotographic method, an ink jet method, or the like can also be applied.

  The pattern layer can basically be formed by using a known printing ink containing a colorant and a resin (binder resin). In particular, a printing ink in which a part or all of the solvent is the mixed solvent of the present invention ( It is desirable to form with the composition of the present invention. For example, a resin solution in which a resin is dissolved in the mixed solvent of the present invention, a resin emulsion in which a resin is dispersed in the solvent of the present invention, and the like can be suitably used as the printing ink. By using the composition of the present invention as a printing ink, it is possible to reliably prevent drying before the ink is transferred from the printing plate to the plastic sheet during printing. In addition, unlike existing inks, most of the solvent of the present invention volatilizes during the production stage, so that the problem of indoor air contamination during use of the decorative sheet can be reduced or eliminated.

  In forming the pattern layer, as a resin (binder resin) suitable for the composition of the present invention, for example, an alkali solution-soluble (meth) acrylic copolymer can be used. This copolymer includes, for example, (meth) acrylic esters, (meth) acrylic monomers such as hydroxyethyl (meth) acrylate and hydroxyethyl methacrylate, nitrile monomers such as (meth) acrylonitrile, and amides such as (meth) acrylamide. Monomer or N-alkoxy substituted or N-methylol substituted amide monomer, styrene monomer such as styrene, vinyl toluene, α-methyl styrene, divinyl benzene, diallyl phthalate, allyl glycidyl ether, tri One or more of allyl monomers such as allyl isocyanurate, monomers having a polymerizable double bond such as vinyl acetate and N-vinylpyrrolidone, and (meth) acrylic maleic anhydride and maleic anhydride having a carboxyl group , There may be mentioned those consisting of fumaric acid, a copolymer of one or more unsaturated carboxylic acids such as itaconic acid.

  In addition, for example, polyarrylamide resin, poly (meth) acrylic acid resin, polyethylene oxide resin, poly N-vinylpyrrolidone resin, water-soluble polyurethane resin (two-component curable polyurethane resin), water-soluble polyester Water-soluble synthetic resins such as water-based resins, water-soluble polyamide-based resins, water-soluble amino-based resins, water-soluble phenol-based resins, water-soluble natural polymers such as polynucleotides, polypeptides, or polysaccharides can also be used. .

  Furthermore, for example, natural rubber, synthetic rubber, polyvinyl acetate resin, (meth) acrylic resin, and polyurethane resin can be used.

  In addition, examples of the resin include urethane resins such as acrylic-modified urethane resins, polyester-modified urethane resins, vinyl chloride-vinyl acetate copolymer-modified urethane resins, polyol resins, or vinyl chloride-vinyl acetate copolymers and acrylic resins. A mixed resin with a resin can also be used.

The adhesive layer adhesive layer 5 is formed on the pattern layer 4 in order to effectively laminate the base sheet 3 and the transparent sheet 6.

  The adhesive layer 5 can be formed using a known adhesive. For example, a widely used resin such as a polyester resin, a polyurethane resin, an acrylic resin, or a two-component cured product thereof can be used.

  In the present invention, any type of solvent type or solventless type adhesive can be used in addition to the aqueous type. That is, it is desirable to use either 1) water or an aqueous solvent, 2) the mixed solvent of the present invention, or 3) the above-mentioned solvent having 5 or less carbon atoms as the solvent. For example, an adhesive using ethyl acetate or the like as a solvent can be suitably used. Thereby, it can contribute to prevention of indoor air pollution effectively.

  The thickness of the adhesive layer is not limited, and varies depending on the type of adhesive used, but is usually set to about 1 to 30 μm.

Transparent sheet transparent sheet 6, in particular but the material is not limited, it is preferable to use a plastic (sheet), especially in the sense of a transparent sheet. More preferably, a polyolefin resin typified by a polypropylene resin is used for the same reason as the base sheet 3. In this case, the various polyolefin-type resin mentioned as what comprises the base material sheet 3 can be used.

  However, the transparent sheet 6 may be colored as long as it has transparency, but it is particularly desirable not to add a colorant.

  The thickness of the transparent sheet 6 is usually about 20 μm to 150 μm, similarly to the base sheet 3, but may exceed the above range depending on the use of the decorative sheet and the like.

  The transparent sheet 6 may be a sheet obtained in advance, but may be laminated by being placed on the adhesive layer 4 and crimped when melt extruded and formed into a sheet. . Lamination by melt extrusion can provide higher adhesiveness and less heat required for heating during embossing as compared to the case of laminating a sheet once. .

The protective layer protective layer 7 is formed on the transparent sheet 6 of the decorative sheet 1. That is, it is laminated on the outermost surface of the decorative sheet.
The protective layer 7 can also be formed with the composition used for formation of the protective layer of a well-known decorative sheet. In particular, a resin solution or resin emulsion obtained by dissolving or dispersing a resin in an appropriate solvent may be used and formed using a known coating or printing means.

  In the present invention, it is desirable to use either 1) water or an aqueous solvent, 2) the mixed solvent of the present invention, or 3) the above-mentioned solvent having 5 or less carbon atoms as the solvent. For example, 1 type, or 2 or more types, such as isopropyl alcohol and ethyl acetate, can be used as a solvent. Thereby, it can contribute to prevention of indoor air pollution effectively.

  The resin is not limited, and a resin (polyester resin, polyurethane resin, acrylic resin, or the like) that is used for forming the adhesive layer may be used.

  In the present invention, an ionizing radiation curable resin can also be used. Unlike the ultraviolet curable composition, the ionizing radiation curable resin does not need to contain a photopolymerization initiator, so that deterioration with time after the decorative sheet 1 is formed can be avoided.

  The ionizing radiation curable resin is not limited, and known ones can be used. In particular, a composition in which a prepolymer, a polymer and / or a monomer having a polymerizable unsaturated bond or a cationic polymerizable functional group in the molecule can be suitably used. More specifically, a monomer having two or more radical polymerizable unsaturated groups such as a (meth) acryloyl group (meth) acryloyloxy group, a cation polymerizable functional group such as an epoxy group, and a thiol group in the molecule, It is composed of a prepolymer or a polymer. These monomers, prepolymers or polymers can be used alone or in combination of two or more.

  Examples of prepolymers having radically polymerizable unsaturated groups include polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, triazine (meth) acrylate, or silicon (meth) acrylate Can be used. The molecular weight is 250 to 10,000. As the polymer having a radical polymerizable unsaturated group, those having a polymerization degree of about 1000 are used.

  Examples of the prepolymer having a cationic polymerizable functional group include a prepolymer of an epoxy resin such as a bisphenol epoxy resin or a novolac epoxy resin, a vinyl ether resin such as an aliphatic vinyl ether, or an aromatic vinyl ether. Examples of the monomer having a radical polymerizable unsaturated group include methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, or phenoxy (meth) acrylate as a monofunctional monomer of a (meth) acrylate compound.

  Examples of polyfunctional monomers having radically polymerizable unsaturated groups include diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide tri (meth) ) Acrylate, dipentaerythritol penta (meth) acrylate, or dipentaerythritol hexa (meth) acrylate.

  As the monomer having a cationic polymerizable functional group, the above-mentioned prepolymer monomer having a cationic polymerizable functional group can be used. Examples of the monomer having a thiol group include trimethylolpropane trithioglycolate and dipentaerythritol tetraglycolate.

  If necessary, the ionizing radiation curable resin may be further blended with a thermoplastic resin such as polyvinyl acetate, an acrylic resin, or a cellulose derivative as a plasticizer or an anti-adhesive agent, or may be calcium carbonate, barium sulfate, silica, alumina, or the like. An extender pigment composed of fine powder can be blended.

When a resin solution or resin emulsion containing an ionizing radiation curable resin is used, gravure coating or roll coating capable of uniform application within a normal application amount range can be suitably used. The coating amount may be the ^{0.5g / m 2 ~30g / m 2} . By setting the amount to be applied, it is possible to effectively absorb the deformation of the concavo-convex pattern that occurs when the base sheet 3 is deformed, and excellent adhesiveness is obtained. Subsequently, it hardens | cures by irradiating an electron beam to the film | membrane formed with the composition containing ionizing radiation curable resin. Irradiation conditions in this case may be in accordance with known conditions, but it is particularly preferable to set the irradiation dose to about 1 Gy to 100 kGy with an acceleration voltage of about 0.1 to 6 MeV.

  In addition, when forming the protective layer 7 using ionizing radiation curable resin, the frequency | count of irradiation of an electron beam will be performed twice in total including the electron beam irradiation at the time of formation of the adhesive bond layer 5. FIG. On the other hand, when the transparent sheet 6 is laminated above the base sheet 3, the electron beam is not irradiated, and when the protective layer 7 is formed, the adhesive layer 5 is cured and the electron beam is irradiated. One irradiation is enough. By doing so, not only can the number of electron beam irradiations be reduced, but also the deterioration of the plastic sheet (particularly the polyolefin resin sheet) can be prevented.

  The protective layer 7 may be formed at any stage, but it is particularly preferable that the protective layer 7 is laminated after the layers including the transparent sheet 6 are laminated on the base sheet 3. Moreover, when using the transparent sheet 6 manufactured by melt extrusion beforehand, you may laminate | stack the protective layer 7 on the transparent sheet 6 previously, and laminate | stack the protective layer 7 after laminating | stacking the transparent sheet 6 with a lower layer. May be.

  In the present invention, a primer layer may be formed when the protective layer 7 (particularly when an ionizing radiation curable resin is used) is laminated. As a composition for forming the primer layer, a resin solution or a resin emulsion obtained by dissolving or dispersing a resin used in the adhesive layer in an appropriate solvent can be used.

  In this case, it is desirable to use any one of 1) water or an aqueous solvent, 2) the mixed solvent of the present invention, or 3) the solvent having 5 or less carbon atoms as the solvent. For example, 1 type, or 2 or more types, such as isopropyl alcohol, ethyl acetate, and methyl ethyl ketone, can be used as a solvent. Thereby, it can contribute to prevention of indoor air pollution effectively.

  Although the thickness of a protective layer can be suitably set according to the kind of material which forms a protective layer, a desired protective layer characteristic, etc., generally it is preferable to set so that it may be set to about 2-25 micrometers.

3. Adhering Material The decorative sheet of the present invention is laminated on various adherends and used as a decorative board. As the adherend, various shapes of articles such as flat materials of various materials, plate materials such as curved plates, three-dimensional shaped articles, sheets (or films), and the like are targeted.

  As a material used for any of the plate material, the three-dimensional shaped article, and the sheet (film), for example, a wood veneer such as a wood veneer, a wood plywood, a particle board, a medium density fiber board (MDF), or the like; iron, Metals such as aluminum; resins such as acrylic resin, polycarbonate, ethylene / vinyl acetate copolymer, ethylene vinyl acetate, polyester resin, polystyrene, polyolefin resin, ABS resin, phenol resin, polyvinyl chloride, cellulose resin, and rubber It is done.

  Moreover, as a raw material used exclusively as a board | plate material or a three-dimensional shaped article, materials, such as glass, ceramics, ceramics, ALC (foamed lightweight concrete), calcium silicate, gypsum, etc. are mentioned, for example. Examples of the material used exclusively as a sheet (or film) include paper such as high-quality paper and Japanese paper, and nonwoven fabric or woven fabric made of fibers such as carbon, asbestos, potassium titanate, glass, and synthetic resin.

  What is necessary is just to implement according to a well-known method as a lamination | stacking method of these decorative sheets to a to-be-adhered body. For example, (1) a method of laminating by pressing with a pressure roller on a plate-like substrate with an adhesive layer interposed therebetween, (2) described in Japanese Patent Publication No. 50-19132, Japanese Patent Publication No. 43-27488, etc. As shown in the figure, a decorative sheet is inserted between both male and female molds for injection molding, both molds are closed, the molten resin is injected and filled from the male mold gate, and then cooled and simultaneously molded with the resin molded product. Adhesive lamination of a decorative sheet on the surface (so-called injection molding simultaneous lamination method), (3) JP-B 56-45768, JP-B 60-58014, etc. Through which a decorative sheet is placed or placed on the surface of the molded product, and the decorative sheet is laminated on the surface of the molded product by a pressure difference caused by vacuum suction from the molded product side (so-called vacuum press lamination method), (4) No. 61-5895, Special As described in Japanese Patent Laid-Open No. 3-2666, a plurality of rollers with different directions are supplied while supplying a decorative sheet in the major axis direction of a columnar substrate such as a cylinder or a polygonal column with an adhesive layer interposed therebetween. As described in (5) Japanese Patent Laid-Open No. 48-47972, etc., a method in which a decorative sheet is laminated by pressing and adhering sequentially to a plurality of side surfaces constituting a columnar body. First, a decorative sheet is laminated on a plate-like substrate via an adhesive layer, and then the cross-section reaching the interface between the decorative sheet and the plate-like substrate on the surface of the plate-like substrate opposite to the decorative sheet Cutting a V-shaped or U-shaped groove, and then applying an adhesive into the groove and then bending the groove to form a box or columnar body (so-called V-cut or U-cut processing method) Etc.

  In particular, among the above methods, the method of laminating the decorative sheet of the present invention on the three-dimensional object is preferably an injection molding simultaneous laminating method, a vacuum press laminating method, a lapping process method, a V-cut process method, or the like.

  What is necessary is just to select suitably from well-known adhesives as an adhesive used for lamination | stacking to a to-be-adhered material according to the kind etc. of a to-be-adhered material. Examples thereof include polyvinyl acetate, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ionomer, butadiene / acrylonitrile rubber, neoprene rubber, natural rubber and the like.

  The decorative sheet of the present invention is laminated on various adherends, subjected to a predetermined molding process and the like, and used for various applications. For example, interior decorations of buildings such as walls, ceilings, floors, doors, door frames, window frames, surface decorations for fittings such as skirting boards, handrails, furniture such as bags, surface decorations such as cabinets for light electrical / OA equipment, automobiles, These include vehicle interiors such as trains, aircraft interiors, and window glass makeup.

  Hereinafter, examples and comparative examples will be shown to describe the features of the present invention in more detail. However, the present invention is not limited to these examples.

Example 1
As shown in FIG. 2, a decorative sheet without a protective layer was produced.

  A polypropylene-based resin film (thickness 60 μm) which was colored and concealed by adding a coloring material was prepared, and corona discharge treatment was performed on the front surface (front surface) and the back surface. This surface (front surface) is gravure-printed with a colored ink using a two-component curable urethane resin as a binder, and an ink using an acrylic resin as a binder (15% by weight isopropyl alcohol, 65% ethyl acetate as an ink solvent). A wood grain pattern layer was formed using a mixed solvent consisting of 10% by weight of propylene glycol monomethyl ether and 10% by weight of propyl acetate. Moreover, the primer layer which used urethane type resin as the binder was formed in the back surface by the gravure printing, and the printing sheet was obtained.

  Next, an adhesive layer is formed with a thickness of 15 μm on the pattern layer using an adhesive composed of a two-component curable urethane resin (using 100% by weight of ethyl acetate as a solvent), and then transparent on the coating film. A polypropylene resin film (thickness 80 μm) was laminated.

Comparative Example 1
As a solvent for the pattern layer ink, 10% by weight of isopropyl alcohol, 40% by weight of methyl ethyl ketone, 2.5% by weight of propylene glycol monomethyl ether, 40% by weight of methyl isobutyl ketone, 5% by weight of butyl acetate and propylene glycol monomethyl ether acetate. A decorative sheet was prepared in the same manner as in Example 1 except that a mixed solvent consisting of 5% by weight was used.

Example 2
As shown in FIG. 3, a decorative sheet having a protective layer was produced.

  A polypropylene-based resin film (thickness 60 μm) which was colored and concealed by adding a coloring material was prepared, and corona discharge treatment was performed on the front surface (front surface) and the back surface. This surface (front surface) is gravure-printed with a colored ink using a two-component curable urethane resin as a binder, and an acrylic resin is used as a binder (as solvent, isopropyl alcohol 15% by weight, ethyl acetate 55% by weight And a mixed solvent composed of 5% by weight of propylene glycol monomethyl ether and 25% by weight of propyl acetate). Moreover, the primer layer which used urethane type resin as the binder was formed in the back surface by the gravure printing, and the printing sheet was obtained.

  Next, an adhesive layer is formed with a thickness of 15 μm on the pattern layer using an adhesive composed of a two-component curable urethane resin (using 100% by weight of ethyl acetate as a solvent), and then transparent on the coating film. A polypropylene resin film (thickness 80 μm) was laminated.

  Next, the laminate obtained by the above laminate is heated from the surface on the side of the transparent polypropylene resin film with an infrared non-contact type heater to soften the transparent polypropylene resin film, and then immediately pressed on the surface under heating. The embossing was applied to form a concavo-convex pattern of wood grain conduit groove pattern. Then, after corona discharge treatment is applied to this surface, a two-component curable acrylic resin (a mixed solvent consisting of 35% by weight of isopropyl alcohol and 65% by weight of ethyl acetate is used as a solvent) is applied to protect about 3 μm. A layer was formed.

Comparative Example 2
As a solvent for the pattern layer ink, 10% by weight of isopropyl alcohol, 40% by weight of methyl ethyl ketone, 2.5% by weight of propylene glycol monomethyl ether, 40% by weight of methyl isobutyl ketone, 5% by weight of butyl acetate and propylene glycol monomethyl ether acetate. Using a mixed solvent consisting of 5% by weight, 10% by weight of isopropyl alcohol, 50% by weight of methyl ethyl ketone, 30% by weight of ethyl acetate, 7.5% by weight of methyl isobutyl ketone and propylene glycol monomethyl ether as a solvent for forming the protective layer A decorative sheet was prepared in the same manner as in Example 1 except that a mixed solvent consisting of 2.5% by weight of acetate was used.

Example 3
As shown in FIG. 4, a decorative sheet using an ionizing radiation curable resin as a protective layer was prepared.

  A polypropylene-based resin film (thickness 60 μm) which was colored and concealed by adding a coloring material was prepared, and corona discharge treatment was performed on the front surface (front surface) and the back surface. This surface (front surface) is gravure-printed with a colored ink using a two-component curable urethane resin as a binder, and an ink using an acrylic resin as a binder (as solvent, isopropyl alcohol 15% by weight, ethyl acetate 55% by weight A wood grain pattern layer 4 was formed using a mixed solvent of 5% by weight of propylene glycol monomethyl ether and 25% by weight of propyl acetate. Moreover, the primer layer 2 which used urethane type resin as the binder was formed in the back surface by the gravure printing, and the printing sheet was obtained.

  Next, an adhesive layer made of a two-component curable urethane resin is formed with a thickness of 15 μm on the pattern layer 4 of the printing sheet, and then a transparent polypropylene resin film (thickness 80 μm) is laminated on the coating film. did.

  A two-component curable urethane-based resin comprising an acrylic-urethane block polymer (main agent) using isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate on the transparent resin layer, and hexamethylene diisocyanate (curing agent). (A mixed solvent composed of 20% by weight of isopropyl alcohol, 60% by weight of methyl ethyl ketone and 20% by weight of methyl isobutyl ketone was used as a solvent) to form a primer layer 8 (thickness 2 μm).

  Next, a urethane acrylate-based ionizing radiation curable resin (using 100% by weight of ethyl acetate as a solvent) is formed by gravure coating, and then irradiated with an electron beam under the conditions of 175 keV and 5 Mrad (50 kGy). A transparent protective layer 7 (thickness 5 μm) was formed by crosslinking and curing the coating film.

  Finally, the transparent protective layer side is heated with an infrared non-contact heater to soften the transparent protective layer and the second transparent resin layer, and then immediately embossed by heat pressure from the surface of the transparent protective layer. Then, a predetermined decorative sheet was obtained by shaping the concavo-convex pattern of the wood grain conduit groove pattern.

Example 4
A decorative sheet was produced in the same manner as in Example 3 except that a mixed solvent consisting of 50% by weight of isopropyl alcohol, 20% by weight of methyl ethyl ketone and 30% by weight of ethyl acetate was used as a solvent for forming the primer for the ionizing radiation curable resin. did.

Comparative Example 3
As solvent for the pattern layer ink, isopropyl alcohol 10% by weight, methyl ethyl ketone 40% by weight, propylene glycol monomethyl ether 2.5% by weight, methyl isobutyl ketone 40% by weight, butyl acetate 5% by weight and propylene glycol monomethyl ether acetate 2.5 A decorative sheet was prepared in the same manner as in Example 3 except that a mixed solvent consisting of% by weight was used.

Test example 1
The amount of residual solvent was measured about the decorative sheet obtained by each Example and the comparative example. Table 1 shows the amount of residual solvent (unit: mg / m ² ) after 28 days from the start of measurement. The measuring method is that the decorative sheet immediately after manufacture is pasted in the room and allowed to stand, and after 28 days, the decorative sheet is measured with “GC-17A” (manufactured by Shimadzu Corporation) and isopropyl alcohol (IPA), methyl ethyl ketone in the decorative sheet. (MEK), ethyl acetate (EtAc), propylene glycol monomethyl ether (PGM), propyl acetate (n-PrAc), methyl isobutyl ketone (MIBK), butyl acetate (n-BuAc) and propylene glycol monomethyl ether acetate (PGMAc) The total remaining amount of was measured. The measurement conditions were a purge temperature of 120 ° C. for 7 minutes and a syringe temperature of 130 ° C.

It is a figure which shows the structural example of the decorative sheet of this invention. 2 is a diagram illustrating a configuration of a decorative sheet produced in Example 1. FIG. FIG. 6 is a diagram showing a configuration of a decorative sheet produced in Example 2. It is a figure which shows the structure of the decorative sheet produced in Example 3 and 4. FIG.

Explanation of symbols

1 decorative sheet 2 primer layer 3 substrate sheet 4 pattern layer 5 adhesive layer 6 transparent sheet 7 protective layer

Claims (9)

A decorative sheet in which two or more layers are laminated on a base sheet,
At least one layer of said layer is at least 80 wt% of the solvent is isopropyl alcohol, ethyl acetate, Ri Do propylene glycol monomethyl ether and propyl acetate, total 100 weight of isopropyl alcohol, ethyl acetate, propylene glycol monomethyl ether and propyl acetate Isopropyl alcohol and ethyl acetate in total 70 parts by weight or more, propylene glycol monomethyl ether 2.5 parts by weight or more, propyl acetate 20 parts by weight or more, isopropyl alcohol and ethyl acetate in total 70 parts by weight or more of isopropyl alcohol are formed by the fast-drying composition which is a mixed solvent Ru 5-30 parts by der, decorative sheet, characterized in that. The decorative sheet according to claim 1, wherein the decorative sheet is obtained by sequentially laminating at least a pattern layer, an adhesive layer, and a transparent sheet layer on a base sheet. The decorative sheet according to claim 1, wherein the decorative sheet is obtained by sequentially laminating at least a pattern layer, an adhesive layer, a transparent sheet layer, and a protective layer on the base sheet. The decorative sheet according to claim 2 or 3, wherein at least the pattern layer is formed of the quick-drying composition. The decorative sheet according to any one of claims 2 to 4, wherein a primer layer is formed between the transparent sheet layer and the protective layer, and the protective layer is formed of an ionizing radiation curable resin. The decorative sheet according to claim 5, wherein a primer layer and / or a protective layer is formed of the quick-drying composition. The decorative sheet according to any one of claims 1 to 6, wherein the quick-drying composition comprises 80% by weight or more of the mixed solvent and the remaining organic solvent having 5 or less carbon atoms. The organic solvent having 5 or less carbon atoms is at least one selected from the group consisting of methanol, ethanol, isobutanol, pentanol, acetone, methyl ethyl ketone, diethyl ketone, methyl acetate, and isopropyl acetate. Makeup sheet. A method for producing the decorative sheet according to claim 1 ,
At least one of the layers, decorative sheet manufacturing method of which comprises a step of forming by the fast-drying composition of the layer.

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