JP5272232B2 - Decorative sheet, polycarbonate polyurethane resin for forming the decorative sheet, and water-based ink containing the resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decoration sheet suppressing blocking when winding is once carried out at the step of forming a picture pattern layer, and also excellent in color property and weathering stability of the picture pattern layer. <P>SOLUTION: In the decoration sheet formed with at least a picture pattern layer on a substrate sheet, the picture pattern layer is formed of water-based ink including a polycarbonate-based polyurethane resin obtained by reaction of a polyfunctional compound containing liqid polycarbonate polyol at 20&deg;C and a raw material mixture containing polyisocyanate. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a decorative sheet, a polycarbonate-based polyurethane resin for forming the decorative sheet, and a water-based ink containing the resin.

  A decorative sheet is a decorative material for the purpose of surface protection, decoration, etc. of an adherend such as a wooden board. Generally, a base sheet, a colored hiding layer, a pattern layer, an adhesive layer, a transparent resin layer, etc. are laminated. It becomes. The decorative sheet is attached to the surface of an adherend and used as a decorative board. And this decorative board is used for various building materials, furniture, etc.

  In a decorative sheet, conventionally, a colored hiding layer, a pattern layer, an adhesive layer and the like are 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, and the like. It was.

  Aromatic solvents, aliphatic solvents, etc. are organic volatile substances (VOCs). In particular, aromatic solvents such as toluene and xylene are guideline values for designated chemical substances and chemical substances in indoor air in the Chemical Substances Emissions Control Management Act. It is a formulated substance. In addition, it has been pointed out that there are problems in the working environment due to volatilization of VOC contained in the solvent-based coating agent during the manufacture of the decorative sheet, and environmental safety problems in which the remaining VOC is diffused into the general living space when using the decorative sheet . Therefore, a decorative sheet made of an aqueous coating agent with reduced VOC usage has been proposed (Patent Document 1).

  However, the decorative sheet using the aqueous coating agent has the following drawbacks. That is, compared with a decorative sheet using a solvent-based coating agent, the effect of ultraviolet rays emitted by sunlight, fluorescent lamps, etc. is greater. Specifically, among the layers constituting the decorative sheet, the pattern layer tends to deteriorate and weather resistance fading easily. Moreover, the adhesiveness of the pattern layer tends to be lowered.

Further, if the substrate sheet is wound and stored at the stage of the printing original fabric on which the pattern layer is formed, blocking may occur due to the pattern layer and the back surface of the substrate sheet that comes into contact with each other.
JP 2001-38849 A

  An object of the present invention is to provide a decorative sheet in which blocking is suppressed even when winding is performed once at the stage of forming a pattern layer, and the color characteristics and weather resistance stability of the pattern layer are good. And

  As a result of intensive studies, the present inventors have found that the above object can be achieved when using a water-based ink containing a specific resin component as an ink for forming a pattern layer, and the present invention is completed. It came to.

That is, the present invention relates to the following decorative sheet.
1. A decorative sheet in which at least a colored hiding layer, a pattern pattern layer, a transparent adhesive layer and a transparent resin layer are formed in this order on a base sheet,
The base sheet includes polypropylene,
The colored hiding layer is formed of a water-based ink containing a urethane-acrylic copolymer,
The pattern layer is formed of a water-based ink containing a polycarbonate-based polyurethane resin obtained by reacting a raw material mixture containing a polyisocyanate and a polyfunctional compound containing a polycarbonate polyol that is liquid at 20 ° C. ,
The polycarbonate-based polyurethane resin has an acidic group and / or an anionic group obtained by neutralizing the acidic group, and the content of the acidic group and the anionic group is that of the polycarbonate-based polyurethane resin. 1 to 4% by mass,
The transparent adhesive layer is formed of an aqueous composition containing a polycarbonate-based polyurethane resin,
The transparent resin layer includes polypropylene,
A decorative sheet characterized by that.
2. The above- mentioned item, wherein the polycarbonate-based polyurethane resin contained in the pattern layer has an anionic group obtained by neutralizing an acidic group using at least one selected from the group consisting of an inorganic base and an alkanolamine. The decorative sheet according to 1.
3. Item 3. The decorative sheet according to Item 1 or 2, wherein the water-based ink has a polycarbonate-based polyurethane resin dispersed in a water-containing dispersion medium.
4). Item 4. The decorative sheet according to any one of Items 1 to 3, wherein the acidic group is at least one selected from the group consisting of a carboxyl group and a sulfonic acid group.
5. Item 5. The decorative sheet according to any one of Items 1 to 4, wherein the polyisocyanate is a non-yellowing polyisocyanate.
6). The decorative sheet according to any one of Items 1 to 5, wherein a colored hiding layer, a pattern pattern layer, a transparent adhesive layer, a transparent resin layer, and a transparent surface protective layer are sequentially laminated on the base material sheet. .
7). A decorative board formed by laminating the decorative sheet according to any one of Items 1 to 6 and an adherend.

  Since the decorative sheet of the present invention uses a water-based ink containing a specific polycarbonate-based polyurethane resin as the ink for forming the pattern layer, the weather resistance and weather fading of the pattern layer are good. Further, even when the film is wound and stored at the stage of the printing original fabric on which the pattern layer is formed, blocking of the printing original fabric is suppressed.

  The decorative sheet of the present invention can be applied to either the case where the resin-containing layer (excluding the pattern layer) is formed with a solvent-based coating agent or the case where it is formed with a water-based coating agent (aqueous composition). When one or more resin-containing layers are formed from an aqueous composition, the amount of VOC used in the decorative sheet can be reduced, which is preferable from the environmental viewpoint.

  Hereinafter, about the decorative sheet of this invention, after demonstrating a pattern pattern layer, the specific structure of a decorative sheet is demonstrated exemplarily.

Pattern Pattern Layer The pattern pattern layer according to the present invention is a water-based ink containing a polycarbonate-based polyurethane resin obtained by reacting a raw material mixture containing a polyfunctional compound containing a polycarbonate polyol that is liquid at 20 ° C. and a polyisocyanate. To form.

  The polycarbonate-based polyurethane resin has a carbonate group (—O—CO—O—) and a urethane group (—NH—CO—O—) in its structure, and plays a role as a binder resin in aqueous ink. . In the present invention, in particular, the pattern layer is formed by water-based ink because it is obtained by reacting a raw material mixture containing a polyfunctional compound containing “polycarbonate polyol which is liquid at 20 ° C.” and polyisocyanate. In addition, the color is hardly dulled to the same extent or more than when solvent-based ink is used. As a result, the vividness of the pattern layer and the clarity of the color are good. Moreover, the weather-resistant adhesion is also good.

  The polycarbonate-based polyurethane resin can be obtained by reacting a raw material mixture containing a polyfunctional compound containing a polycarbonate polyol which is liquid at 20 ° C. and a polyisocyanate.

  The polyfunctional compound is a compound having two or more active hydrogens capable of reacting with an isocyanate group, and contains a polycarbonate polyol that is liquid at 20 ° C. as an essential component. The polyfunctional compound will be described in detail later, but may further include a “polyfunctional compound capable of introducing an acidic group”, a “chain extender” and the like.

  Although content of the polycarbonate polyol in a polyfunctional compound is not limited, about 30-80 mass% is preferable. “Liquid” at 20 ° C. means a range of 300 to 400,000 mPa · s measured with a B-type viscometer (Tokyo Keiki) at 20 ° C.

  Polycarbonate polyol that is liquid at 20 ° C. can be synthesized by, for example, phosgenation of polyol, transesterification with diphenyl carbonate, condensation polymerization of dialkyl carbonate and diols, and the like.

  As the polycarbonate polyol which is liquid at 20 ° C., for example, poly [(1,5-pentanediol / 1,6-hexanediol) carbonate] (1,5-pentanediol / 1,6-hexanediol = 75/25 25/75 (molar ratio)), poly [(3-methyl-1,5-pentanediol / 1,6-hexanediol) carbonate] (3-methyl-1,5-pentanediol / 1,6-hexane Diol = 90 / 10-50 / 50 (molar ratio)), poly [(1,9-nonanediol / 2-methyl-1,8-octanediol) carbonate] (1,9-nonanediol / 2-methyl- 1,8-octanediol) carbonate = 90/10 to 10/90 (molar ratio)), poly [(1,4-cyclohexanedimethanol / 1, - hexanediol) carbonate] (1,4 / 1,5 = 40 / 60-60 / 40 (molar ratio)), and the like. In the above, diols are exemplified, but polyols include those having OH group number of triol or higher. These polycarbonate polyols can be used alone or in combination of two or more.

  In addition, it is preferable that the number average molecular weight of the polycarbonate polyol which is liquid at 20 degreeC is 500-10000, More preferably, it is 1000-3000. When the number average molecular weight is less than 500, the adhesion of the pattern ink layer tends to be lowered, and when the number average molecular weight exceeds 10,000, blocking may occur.

  Further, as the polyfunctional compound, in addition to the polycarbonate polyol that is liquid at 20 ° C., as other polyol components, conventionally known polyester polyols and polyether polyols, and polycarbonate polyols that are not liquid at 20 ° C. may be used in combination. .

  Examples of the polyisocyanate to be reacted with the polyfunctional compound include aliphatic polyisocyanate, alicyclic polyisocyanate, and aromatic polyisocyanate.

  Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate (HDI) and lysine diisocyanate (LDI).

Examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI), cyclohexane-1,4-diisocyanate, hydrogenated xylylene diisocyanate (H ₆ XDI), hydrogenated diphenylmethane diisocyanate (H ₁₂ MDI), and the like.

  Examples of the aromatic polyisocyanate include tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate, 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, etc., diphenylmethane diisocyanate (MDI), 1,3- Phenylene diisocyanate (PDI) such as phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-chloro-2,4-phenylene disissocyanate, 4,4′-diphenyl diisocyanate, 3,3′-dimethyl-4,4′- Diphenyl diisocyanate such as diphenyl diisocyanate, 3,3′-dimethoxy-4,4′-diphenyl diisocyanate, xylylene diisocyanate (XDI), tetramethylxylene diisocyanate (TMXDI) Naphthalene diisocyanates such as 1,5-naphthalene diisocyanate (NDI) and the like.

  Other examples of polyisocyanates include adducts of the above polyisocyanates with polyhydric alcohols (such as trimethylolpropane) or polyamines, burette reaction products, polymeric polyisocyanates having isocyanurate rings, and the like.

  Polyisocyanate can be used individually or in mixture of 2 or more types. The polyisocyanate includes diisocyanate (aliphatic diisocyanate, alicyclic diisocyanate, aromatic diisocyanate). Among the polyisocyanates, non-yellowing polyisocyanates are particularly preferable. Specifically, the above aliphatic diisocyanate and alicyclic diisocyanate correspond to the non-yellowing type.

The polycarbonate-based polyurethane resin preferably has water solubility or water dispersibility. In order to have such characteristics, for example, it is desirable that the polycarbonate-based polyurethane resin contains a hydrophilic anionic group (carboxylate group —COO ⁻ , sulfonate group —SO ₃ ^— or the like). Such an anionic group can be introduced, for example, by introducing an acidic group (carboxyl group, sulfonic acid group, etc.) into a polycarbonate polyurethane resin and then neutralizing the acidic group with a base.

  In order to introduce the acidic group into the polycarbonate-based polyurethane resin, for example, a polyfunctional compound capable of introducing an acidic group may be used in combination as the polyfunctional compound. Examples of such polyfunctional compounds include carboxyl group-containing diols such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, and 2,2-dimethylolvaleric acid; lysine, arginine, ornithine, Carboxyl groups or sulfonic acid group-containing diols such as carboxyl groups or sulfonic acid group-containing diamines such as aspartic acid, glutamic acid, diaminopropionic acid, diaminobenzoic acid, diaminobenzene sulfonic acid, and the like; Carboxy group-containing polyether diol produced by addition ring-opening polymerization of a carboxyl group-containing diol and a lactone; the diol, a polyvalent carboxylic acid having three or more carboxyl groups, or a derivative thereof (for example, trimellitic acid, anhydrous A carboxy group-containing polyether diol produced by a reaction of limellitic acid, methylcyclohexenylcarboxylic acid anhydride, vilromellitic acid, etc.) with an aliphatic or aromatic dicarboxylic acid or its derivative, if necessary. Examples thereof include polyether diols containing sulfoisophthalic acid units used as the divalent carboxylic acid component.

  Examples of bases that neutralize acidic groups include inorganic bases (alkali metal hydroxides such as ammonia, sodium hydroxide, and potassium hydroxide), and organic bases (dimethylamine, trimethylamine, diethylamine, triethylamine, triisopropylamine). Aliphatic amines such as monoethanolamine, dimethylethanolamine, ethylethanolamine, diethylethanolamine, diisopropylethanolamine, diethanolamine, methyldiethanolamine, ethyldiethanolamine, isopropyldiethanolamine, alkanolamines such as triethanolamine, triisopropanolamine, morpholine Etc.) can be used. Among these, an alkali metal hydroxide is preferable as the inorganic base, and an alkanolamine is preferable as the organic base.

  Furthermore, in this invention, you may use together a chain extender as a polyfunctional compound. The chain extender includes, for example, low molecular weight polyhydric alcohols such as ethylene glycol, propylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, pentaerythritol; ethylenediamine, hexamethylenediamine And low molecular weight polyamines such as diaminocyclohexylmethane, piperazine, diethylenetriamine, and triethylenetetramine.

  The polycarbonate polyurethane resin has an acidic group and an anionic group content (total amount of acidic group and anionic group) obtained by neutralizing the acidic group of 1% by mass or more of the polycarbonate polyurethane resin. It is preferable that it is 2 to 4% by mass. When the content is less than 1% by mass, there is a possibility that a problem may occur in emulsification property or ink characteristics may be insufficient. Moreover, when content exceeds 4 mass%, there exists a possibility that the water resistance of polycarbonate-type polyurethane resin may fall. About content of such an acidic group and an anionic group, it adjusts by increase / decrease in the introduction amount of an acidic group, or the usage-amount of a neutralizing agent, for example.

  The polycarbonate-based polyurethane resin is, for example, a polyisocyanate, a polycarbonate polyol that is liquid at 20 ° C., other polyol components, a polyfunctional compound that can introduce an acidic group, and, if necessary, an isocyanate group by reacting with a chain extender. A terminal prepolymer neutralized product is prepared and then subjected to a chain extension reaction in water with at least one compound selected from water-soluble polyamines, hydrazine or derivatives thereof, or simultaneously with the chain extension reaction, a terminal isocyanate group Obtained by blocking. The reaction temperature for preparing the prepolymer is preferably 40 to 150 ° C., and a known reaction catalyst or an organic solvent that does not react with an isocyanate group may be used in combination as appropriate. The polycarbonate-based polyurethane resin thus obtained can be used as a binder resin for water-based inks as in the present invention, taking advantage of its heat resistance, weather resistance, low odor, etc., metal, plastic, fiber, It can also be used as a coating agent for paper.

  The water-based ink may be the same as the known water-based ink except that it contains the polycarbonate-based polyurethane resin as a binder resin (binder). As the binder resin, only the above-mentioned polycarbonate-based polyurethane resin may be used, but a known binder resin can be mixed as long as the effects of the present invention are not hindered. The colorant, solvent (water or aqueous solvent), etc. contained in the water-based ink are as follows.

  The colorant is not particularly limited, and a known colorant can be used. For example, inorganic pigments such as titanium white, zinc white, petal, vermilion, ultramarine blue, cobalt blue, titanium yellow, carbon black; isoindolinone, Hansa Yellow A, quinacridone, permanent red 4R, phthalocyanine blue, indanthrene blue RS, Examples thereof include organic pigments or dyes such as annin phosphorus black; metal pigments such as aluminum and brass; pearlescent pigments made of foil powder such as titanium dioxide-coated mica and basic lead carbonate. These can be used alone or in combination of two or more.

  The water that is the solvent can be, for example, industrial water of a grade that is used in known aqueous coating agents.

  Further, as the aqueous solvent, a mixed solvent composed of water and an organic solvent can be used. As the organic solvent, for example, water-soluble organic solvents such as glycols and glycol esters can be suitably used in addition to lower alcohols such as ethanol, methanol, isopropyl alcohol, and n-propyl alcohol. The water-soluble organic solvent is used for the purpose of improving the flowability of water-based ink, improving the wettability to the substrate sheet that is the object to be coated, and adjusting the drying property. The type and amount used are determined. In the case of a mixed solvent, the ratio of water and organic solvent can be appropriately adjusted within the range of water: organic solvent 20:80 to 100: 0 (mass ratio). What is necessary is just to determine suitably the usage-amount of the water or water-system solvent in water-based ink from the range which becomes 5 to 70 mass% of total solid content in water-based ink.

  The aqueous ink in the present invention is preferably in a state (resin emulsion) in which the polycarbonate polyurethane resin is dispersed in a dispersion medium containing water (including only water).

  The method for forming the pattern layer using the water-based ink is not limited. For example, it can be formed by gravure printing, flexographic printing, silk screen printing, offset printing or the like on a substrate (for example, a substrate sheet or a colored hiding layer) on which a pattern layer is to be formed. In addition to natural material patterns or patterns such as wood grain and joints, the design pattern layer imparts designs such as characters and figures to the decorative sheet.

  The colored hiding layer may be referred to as a decorative layer together with the pattern layer. The coloring hiding layer is a so-called solid ink layer provided between the base material sheet and the pattern layer. The ink used for forming the colored hiding layer is not limited, but a known printing ink can be used in addition to the water-based ink in the present invention. The method for forming the colored hiding layer is the same as described above.

  The thickness of the decoration layer is not limited, and the thickness of the colored hiding layer is preferably about 0.1 to 20 μm, and more preferably about 1 to 10 μm. The thickness of the pattern layer is preferably about 0.1 to 15 μm, and more preferably about 1 to 10 μm.

  In the case where the colored hiding layer and the pattern layer are formed on the base sheet, the adhesion and decoration between the decorative layer and the base sheet even if winding is performed once at the original printing stage where the decorative layer is formed. The durability of the layer is good, and the occurrence of blocking is suppressed.

Specific configuration of the decorative sheet The specific configuration of the decorative sheet is not limited. For example, a decorative sheet in which a decorative layer (colored hiding layer and picture pattern layer), a transparent adhesive layer, and a transparent resin layer are laminated on a base material sheet can be mentioned. Moreover, the decorative sheet which further provided the transparent protective layer on the transparent resin layer is also mentioned.

  The method for forming the adhesive layer, the transparent resin layer, and the transparent protective layer is not limited. For example, printing such as gravure printing, flexographic printing, silk screen printing, offset printing, transfer printing; application of spray, roller, brush, etc. Any of laminated products such as sheet-like materials can be employed. What is necessary is just to select combining suitably from these methods according to the characteristic, raw material, etc. of each layer. It is desirable from an environmental viewpoint that at least one of the layers containing the resin is formed by lamination of a molded body or a coating film made of an aqueous composition.

  The following is an example of a decorative sheet having a decorative layer (colored hiding layer and pattern layer) on a base sheet and laminating a transparent adhesive layer, a transparent resin layer and a transparent protective layer on the decorative layer. The layers other than the decorative layer will be described.

≪Base material sheet≫
A decorative layer (colored hiding layer and pattern layer) is sequentially laminated on the front surface of the base sheet.

  As a base material sheet, what was formed with the thermoplastic resin is suitable. Specifically, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, polycarbonate, polyethylene naphthalate, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer Polymers, ionomers, acrylic esters, methacrylic esters and the like.

  The base sheet may be colored with a colorant (pigment or dye). Examples of the colorant include inorganic pigments such as titanium dioxide, carbon black and iron oxide, and organic pigments such as phthalocyanine blue, and various dyes. The colorant can be used alone or in combination of two or more. What is necessary is just to set the addition amount of a coloring agent suitably according to a desired hue.

  The base sheet may contain various additives such as fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, antioxidants, ultraviolet absorbers, and light stabilizers as necessary. Good.

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

  The base sheet may be subjected to corona discharge treatment on the front surface in order to increase the adhesion of the decorative layer. The method and conditions for the corona discharge treatment may be in accordance with ordinary methods. If necessary, the back surface of the base sheet can be subjected to corona discharge treatment.

≪Transparent adhesive layer≫
In the present invention, a transparent adhesive layer is interposed between the decorative layer and the transparent resin layer. The adhesive used in the adhesive layer can be appropriately selected depending on the components constituting the pattern layer or the transparent resin layer. For example, various adhesives including polyurethane resin, polyacrylic resin, polycarbonate resin, epoxy resin and the like can be used. In addition to the reactive curing type, an adhesive such as a hot melt type, an ionizing radiation curing type, and an ultraviolet curing type may be used.

  In the present invention, an adhesive capable of thermocompression bonding is used, and the pattern layer and the transparent resin layer can be laminated by thermocompression bonding.

  The adhesive layer may be transparent or translucent as long as the pattern layer can be recognized.

  The adhesive layer is desirably formed of an aqueous composition in that the VOC of the decorative sheet can be reduced. As the aqueous composition, a composition containing an aqueous binder can be used. The aqueous binder may be in any form such as an aqueous resin solution or an aqueous resin emulsion.

  In the present invention, a known easy adhesion treatment such as a corona discharge treatment, a plasma treatment, a degreasing treatment, a surface roughening treatment or the like can be applied to the adhesion surface as necessary.

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

≪Transparent resin layer≫
The transparent resin layer may be colored as long as it is transparent. Moreover, it may be translucent as long as the decorative layer is visible.

  Examples of the resin include polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer, and ionomer. , Polymethylpentene, acrylic acid ester, methacrylic acid ester, polycarbonate, cellulose triacetate and the like. The transparent resin layer is particularly preferably a polyolefin resin such as polypropylene. More preferably, it is a polyolefin resin having stereoregularity. When a polyolefin resin is used, it is desirable to form a transparent resin layer by extruding a molten polyolefin resin.

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

  The thickness of the transparent resin layer is not particularly limited, but is generally about 10 to 200 μm.

≪Transparent protective layer≫
The transparent protective layer may be colored as long as it is transparent. Further, it may be translucent as long as the decoration layer is visible. By forming the transparent protective layer, the surface of the decorative sheet can be easily damaged and the scratch resistance can be improved.

  The material used for the transparent protective layer is not particularly limited, and the same materials as known decorative sheets can be used. In the present invention, it is desirable to use a two-component curable urethane resin. The two-component curable urethane resin is not particularly limited as long as it has a polyol as a main component and an isocyanate as a crosslinking agent (curing agent), and a commercially available product can also be used. As the polyol and isocyanate, those listed in the adhesive layer can be preferably used.

  In the present invention, it is desirable that the transparent protective layer is formed of an aqueous composition in that the effects such as VOC reduction are further enhanced. As the aqueous composition, a composition containing an aqueous binder can be used. The aqueous binder may be in any form such as an aqueous resin solution or an aqueous resin emulsion. The resin used for these may be the same as the aqueous binder of the aqueous composition used for forming the decorative layer.

  In the present invention, an ionizing radiation curable resin can also be used as the transparent protective layer. When using an ionizing radiation curable resin, the scratch resistance, weather resistance, etc. are particularly good.

  A well-known thing or a commercial item can be used for ionizing radiation curable resin. Specifically, a composition containing at least one of a prepolymer, an oligomer and a monomer having a polymerizable unsaturated bond or an epoxy group in the molecule is used.

  Examples of the prepolymer or oligomer include, for example, methacrylates such as polyester methacrylate, polyether methacrylate, polyol methacrylate, and melamine methacrylate, urethane acrylates, polyester acrylate, polyether acrylate, urethane acrylate, polyol acrylate, There are acrylates such as melamine acrylate.

  Monomers include styrene monomers such as styrene and α-methylstyrene, acrylic acid such as methyl acrylate, 2-ethylhexyl acrylate, methoxyethyl acrylate, butoxyethyl acrylate, butyl acrylate, and phenyl acrylate. Examples include esters, methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, ethoxymethyl methacrylate, phenyl methacrylate, and lauryl methacrylate.

  As substituted amino alcohol esters of unsaturated acids, acrylic acid-2- (N, N-diethylamino) ethyl, methacrylic acid-2- (N, N-diethylamino) ethyl, acrylic acid-2- (N, N- Dibenzylamino) methyl, acrylic acid-2- (N, N-diethylamino) propyl, and the like.

  In addition, unsaturated carboxylic acid amides such as acrylamide and methacrylamide, ethylene glycol diacrylate, propylene glycol diacrylate, neobenzyl glycol diacrylate, 1,6-hexanediol diacrylate, ethyl carbitol acrylate, diethylene glycol diacrylate, A compound such as triethylene glycol diacrylate, a multifunctional product such as dipropylene glycol diacrylate, ethylene glycol acrylate, diethylene glycol dimethacrylate, or polyethylene glycol diacrylate, and / or having two or more thiol groups in the molecule Polythiol compounds such as trimethylolpropane trithioglycolate, trimethylolpropane trithiopropiolate, There are data pentaerythritol tetra thioglycolic like. Examples of the acrylate monomer having three or more functional groups include trimethylolpropane triacrylate, pentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, and the like.

  Although the formation method of the transparent protective layer by ionizing radiation curable resin is not limited, For example, it can form by irradiating the ionizing radiation to the coating film of the composition (coating material) containing ionizing radiation curable resin. The ionizing radiation may be any ionizing radiation curable resin contained in the paint and any energy that can act on the radical photopolymerization initiator / sensitizer as an additive to initiate a radical polymerization reaction. And electromagnetic waves such as γ rays. Among these, the electron beam is most practical from the viewpoint of the curing ability of the coating film and the simplicity of the irradiation device. In the case of electron beam irradiation, for example, the film may be crosslinked and cured by electron beam irradiation under conditions of 175 keV and 5 Mrad (50 kGy). In the case where the transparent protective layer is formed of an ionizing radiation curable resin, it is desirable to previously provide a primer layer (particularly a primer layer made of a urethane resin) on the transparent resin layer as a base.

  Although the thickness of a transparent protective layer is not limited, Usually, it is desirable to set it as 0.1-50 micrometers, especially 1-20 micrometers.

  The transparent protective layer (the outermost surface of the decorative sheet) may be provided with an uneven pattern by embossing. More preferably, the embossed recess is subjected to a wiping process in which ink is filled, and the surface is coated with a two-component curable urethane resin (overcoat treatment).

  Embossing is performed to give a desired texture such as the surface of a wood board to the decorative sheet. For example, after heating and softening the transparent protective layer on a heating drum, it is further heated to 140 to 170 ° C. with an infrared radiation heater, pressed and shaped with an embossed plate provided with an uneven pattern of a desired shape, and cooled. Fixed and formed. For this, a known single wafer or rotary embossing machine may be used. Examples of the concavo-convex pattern include a wood grain conduit groove, a float pattern (a concavo-convex pattern of a raised annual ring), a hairline, a grain, a satin, and the like, and a desired pattern can be appropriately selected from these.

  The wiping process is a process of filling ink while scratching the surface with a doctor blade in a recess provided by embossing. As the wiping ink, an ink having a two-component curable urethane resin as a binder can be used. In the wiping process, the product value can be increased by expressing the design closer to the actual wood grain, particularly by performing on the wood grain conduit groove unevenness.

  In the present invention, the transparent protective layer may contain other components. For example, additives such as a solvent, an ultraviolet absorber, an antioxidant, a dispersant, a light stabilizer, a gloss adjusting agent, an antiblocking agent, and a lubricant can be blended.

Decorative plate The decorative plate of the present invention is obtained by laminating the decorative sheet of the present invention on a substrate (adhesive material). More specifically, the sheet is laminated on the substrate so that the transparent protective layer of the decorative sheet becomes the outermost surface layer.

≪Base material≫
The base material to which the decorative sheet of the present invention is applied is not limited, and the same substrate as a known decorative sheet can be used. For example, wood materials, metals, ceramics, plastics, glass and the like can be mentioned. In particular, the decorative sheet of the present invention can be suitably used for a wood material. Specifically, wood materials include veneer, wood veneer, wood plywood, particle board, medium density fiberboard (MDF) made from various materials such as cedar, firewood, firewood, pine, lawan, teak, and melapie. ) And the like.

≪Lamination on substrate≫
The lamination of the decorative sheet to the base material can be performed in the same manner as the lamination of a known decorative sheet. For example, it is possible to suitably laminate a decorative sheet on a substrate by using an adhesive.

  As the adhesive that can be used, any type of adhesive such as a thermoplastic resin, a thermosetting resin, and a rubber can be used. As this, a known product or a commercially available product can be used.

  Thermoplastic resin adhesives include polyvinyl acetate resin, polyvinyl alcohol, polyvinyl acetal (polyvinyl formal, polyvinyl butyral, etc.), cyanoacrylate, polyvinyl alkyl ether, polyvinyl chloride, polyamide, polymethyl methacrylate, nitrocellulose, acetic acid Examples include cellulose, thermoplastic epoxy, polystyrene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and the like.

  Thermosetting resin adhesives include urea resin, melamine resin, phenol resin, resorcinol resin, furan resin, epoxy resin, unsaturated polyester resin, polyurethane resin, polyimide, polyamideimide, polybenzimidazole, polybenzothiazole, etc. Illustrated.

Rubber (elastomer) adhesives include natural rubber, recycled rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, butyl rubber, polysulfide rubber, silicone rubber, polyurethane rubber, stereo rubber (synthetic natural rubber), ethylene propylene rubber And block copolymer rubber (SBS, SIS, SEBS, etc.).

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

  In the synthesis examples and comparative synthesis examples, the viscosity of the polycarbonate polyol was measured by the following measuring method. That is, the polycarbonate polyol adjusted to 20 ° C. was measured with a B-type rotational viscometer manufactured by Tokyo Keiki (type: BH, No. 7 rotor used, rotation speed: 10 rpm).

Synthesis Example 1 (Polycarbonate diol, COOH group and COO-group content at 20 ° C: 1.6% by mass)
To a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen blowing tube, poly [(3-methyl-1,5-pentanediol / 1,6-hexanediol) carbonate] (average molecular weight 2, 000, 3-methyl-1,5-pentanediol / 1,6-hexanediol = 90/10 (molar ratio): viscosity 76000 mPa · s) 167.9 g, 2,2-dimethylolbutanoic acid 15.8 g, dibutyl Add 0.001 tin dilaurate and 95 g of methyl ethyl ketone, mix uniformly, add 100.0 g of cyclohexylmethane diisocyanate, react at 80 ° C. for a predetermined time, and a prepolymer having a free isocyanate group content of 4.2 mass% with respect to the nonvolatile content. A methyl ethyl ketone solution was obtained. This solution was cooled to 30 ° C. and neutralized by adding 21.4 g of a 20% -aqueous sodium hydroxide solution, and then 520 g of water was gradually added and emulsified and dispersed. To this emulsified dispersion, 18.2 g of hexamethylenediamine and 2.4 g of diethylenetriamine were added and stirred for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain a polycarbonate-based polyurethane resin aqueous dispersion having a solid content of about 35% by mass.

  The content of carboxyl groups and carboxylate groups derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this aqueous dispersion was 1.6% by mass.

Synthesis example 2 (polycarbonate polyol in liquid form at 20 ° C., COOH group and COO-group content: 2.0 mass%)
A reactor similar to that used in Synthesis Example 1 was charged with poly [(3-methyl-1,5-pentanediol / 1,6-hexanediol) carbonate] (average molecular weight 2,000, 3-methyl-1, 5-pentanediol / 1,6-hexanediol = 90/10 (molar ratio): viscosity 76000 mPa · s) 137.4 g, 2,2-dimethylolbutanoic acid 18.1 g, dibutyltin dilaurate 0.001 and methyl ethyl ketone 85 g Was added, and 100.0 g of cyclohexylmethane diisocyanate was added and allowed to react at 80 ° C. for a predetermined time to obtain a methyl ethyl ketone solution of a prepolymer having a free isocyanate group content of 4.7% by mass relative to the non-volatile content. The solution was cooled to 30 ° C., neutralized by adding 24.4 g of a 20% aqueous sodium hydroxide solution, and then 460 g of water was gradually added to emulsify and disperse. To this emulsified dispersion, 18.2 g of hexamethylenediamine and 2.4 g of diethylenetriamine were added and stirred for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain a polycarbonate-based polyurethane resin aqueous dispersion having a solid content of about 35% by mass.

  The content of carboxyl groups and carboxylate groups derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this aqueous dispersion was 2% by mass.

Synthesis Example 3 (polycarbonate polyol, COOH group and COO-group content: 2.4% by mass at 20 ° C)
A reactor similar to that used in Synthesis Example 1 was charged with poly [(3-methyl-1,5-pentanediol / 1,6-hexanediol) carbonate] (average molecular weight 2,000, 3-methyl-1, 5-pentanediol / 1,6-hexanediol = 90/10 (molar ratio): viscosity 76,000 mPa · s) 114.5 g, 2,2-dimethylolbutanoic acid 19.8 g, dibutyltin dilaurate 0.001 and After 100 g of methyl ethyl ketone was added and mixed uniformly, 100.0 g of cyclohexylmethane diisocyanate was added and reacted at 80 ° C. for a predetermined time to obtain a methyl ethyl ketone solution of a prepolymer having a free isocyanate group content of 4.8% by mass relative to the nonvolatile content. . This solution was cooled to 30 ° C., neutralized by adding 26.7 g of a 20% -aqueous sodium hydroxide solution, and then 430 g of water was gradually added and emulsified and dispersed. To this emulsified dispersion, 18.2 g of hexamethylenediamine and 2.4 g of diethylenetriamine were added and stirred for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain a polycarbonate-based polyurethane resin aqueous dispersion having a solid content of about 35% by mass.

  The content of carboxyl groups and carboxylate groups derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this aqueous dispersion was 2.4% by mass.

Synthesis example 4 (polycarbonate polyol which is liquid at 20 ° C., different molecular weight, COOH group and COO-group content: 2.8% by mass)
A reactor similar to that used in Synthesis Example 1 was charged with poly [(3-methyl-1,5-pentanediol / 1,6-hexanediol) carbonate] (average molecular weight 1,000, 3-methyl-1, 5-pentanediol / 1,6-hexanediol = 90/10 (molar ratio): viscosity 16000 mPa · s) 64.9 g, 2,2-dimethylolbutanoic acid 18.6 g, dibutyltin dilaurate 0.001 and methyl ethyl ketone 61 g Was added, and 100.0 g of cyclohexylmethane diisocyanate was added and reacted at 80 ° C. for a predetermined time to obtain a methyl ethyl ketone solution of a prepolymer having a free isocyanate group content of 6.6% by mass relative to the non-volatile content. This solution was cooled to 30 ° C., neutralized by adding 25.2 g of a 20% -aqueous sodium hydroxide solution, and then 350 g of water was gradually added to emulsify and disperse. To this emulsified dispersion, 18.2 g of hexamethylenediamine and 2.4 g of diethylenetriamine were added and stirred for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain a polycarbonate-based polyurethane resin aqueous dispersion having a solid content of about 35% by mass.

  The content of carboxyl groups and carboxylate groups derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this aqueous dispersion was 2.8% by mass.

Synthesis example 5 (polycarbonate polyol which is liquid at 20 ° C., different molecular weight, COOH group and COO-group content: 1.6 mass%)
A reactor similar to that used in Synthesis Example 1 was charged with poly [(3-methyl-1,5-pentanediol / 1,6-hexanediol) carbonate] (average molecular weight 3,000, 3-methyl-1, 5-pentanediol / 1,6-hexanediol = 90/10 (molar ratio): viscosity 210000 mPa · s) 206.1 g, 2,2-dimethylolbutanoic acid 18.1 g, dibutyltin dilaurate 0.001 and methyl ethyl ketone 139 g Was added, and 100.0 g of cyclohexylmethane diisocyanate was added and reacted at 80 ° C. for a predetermined time to obtain a prepolymer methyl ethyl ketone solution having a free isocyanate group content of 3.5% by mass relative to the nonvolatile content. The solution was cooled to 30 ° C. and neutralized by adding 24.5 g of a 20% -aqueous sodium hydroxide solution, and then 580 g of water was gradually added and emulsified and dispersed. To this emulsified dispersion, 18.2 g of hexamethylenediamine and 2.4 g of diethylenetriamine were added and stirred for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain a polycarbonate-based polyurethane resin aqueous dispersion having a solid content of about 35% by mass.

  The content of carboxyl groups and carboxylate groups derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this aqueous dispersion was 1.6% by mass.

Synthesis Example 6 (polycarbonate polyol in liquid form at 20 ° C, different types, COOH group and COO-group content: 2% by mass)
A reactor similar to that used in Synthesis Example 1 was charged with poly [(1,5-pentanediol / 1,6-hexanediol) carbonate] (average molecular weight 2,000, 1,5-pentanediol / 1,6. -Hexanediol = 50/50 (molar ratio): Viscosity 86000 mPa · s) 137.4 g, 2,2-dimethylolbutanoic acid 18.1 g, dibutyltin dilaurate 0.001 and methyl ethyl ketone 110 g were added and mixed uniformly. Then, 100.0 g of cyclohexylmethane diisocyanate was added and allowed to react at 80 ° C. for a predetermined time to obtain a methyl ethyl ketone solution of a prepolymer having a free isocyanate group content of 4.4 mass% with respect to the nonvolatile content. This solution was cooled to 30 ° C. and neutralized by adding 24.5 g of a 20% -aqueous sodium hydroxide solution, and then 470 g of water was gradually added and emulsified and dispersed. To this emulsified dispersion, 18.2 g of hexamethylenediamine and 2.4 g of diethylenetriamine were added and stirred for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain a polycarbonate-based polyurethane resin aqueous dispersion having a solid content of about 35% by mass.

  The content of carboxyl groups and carboxylate groups derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this aqueous dispersion was 2% by mass.

Synthesis Example 7 (polycarbonate polyol in liquid form at 20 ° C., neutralized salt difference: alkanolamine, COOH group and COO-group content: 2% by mass)
A reactor similar to that used in Synthesis Example 1 was charged with poly [(3-methyl-1,5-pentanediol / 1,6-hexanediol) carbonate] (average molecular weight 2,000, 3-methyl-1, 5-pentanediol / 1,6-hexanediol = 90/10 (molar ratio): viscosity 76000 mPa · s) 137.4 g, 2,2-dimethylolbutanoic acid 18.1 g, dibutyltin dilaurate 0.001 and methyl ethyl ketone 110 g And then uniformly mixed, 100.0 g of cyclohexylmethane diisocyanate was added and reacted at 80 ° C. for a predetermined time to obtain a methyl ethyl ketone solution of a prepolymer having a free isocyanate group content of 4.4 mass% based on the nonvolatile content. The solution was cooled to 30 ° C. and neutralized by adding 10.9 g of dimethylaminoethanol, and then 470 g of water was gradually added and emulsified and dispersed. To this emulsified dispersion, 18.2 g of hexamethylenediamine and 2.4 g of diethylenetriamine were added and stirred for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain a polycarbonate-based polyurethane resin aqueous dispersion having a solid content of about 35% by mass.

  The content of carboxyl groups and carboxylate groups derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this aqueous dispersion was 2% by mass.

Synthesis Example 8 (polycarbonate polyol which is liquid at 20 ° C, different isocyanate: IPDI, COOH group and COO-group content: 2% by mass)
A reactor similar to that used in Synthesis Example 1 was charged with poly [(3-methyl-1,5-pentanediol / 1,6-hexanediol) carbonate] (average molecular weight 2,000, 3-methyl-1, 5-pentanediol / 1,6-hexanediol = 90/10 (molar ratio): viscosity 76000 mPa · s) 175.7 g, 2,2-dimethylolbutanoic acid 20.3 g, dibutyltin dilaurate 0.001 and methyl ethyl ketone 127 g Was added, and 100.0 g of isophorone diisocyanate was added and allowed to react at 80 ° C. for a predetermined time to obtain a methyl ethyl ketone solution of a prepolymer having a free isocyanate group content of 4.5 mass% based on the nonvolatile content. The solution was cooled to 30 ° C. and neutralized by adding 27.5 g of a 20% -aqueous sodium hydroxide solution, and then 520 g of water was gradually added to emulsify and disperse. To this emulsified dispersion, 21.4 g of hexamethylenediamine and 2.8 g of diethylenetriamine were added and stirred for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain a polycarbonate-based polyurethane resin aqueous dispersion having a solid content of about 35% by mass.

  The content of carboxyl groups and carboxylate groups derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this aqueous dispersion was 2% by mass.

Synthesis Example 9 (polycarbonate polyol in liquid form at 20 ° C, isocyanate difference: HDI, COOH group and COO-group content: 2% by mass)
A reactor similar to that used in Synthesis Example 1 was charged with poly [(3-methyl-1,5-pentanediol / 1,6-hexanediol) carbonate] (average molecular weight 2,000, 3-methyl-1, 5-pentanediol / 1,6-hexanediol = 90/10 (molar ratio): Viscosity 76000 mPa · s) 250.0 g, 2,2-dimethylolbutanoic acid 25.6 g, dibutyltin dilaurate 0.001 and methyl ethyl ketone 127 g And then uniformly mixed, 100.0 g of hexamethylene diisocyanate was added, and the mixture was reacted at 80 ° C. for a predetermined time to obtain a methyl ethyl ketone solution of a prepolymer having a free isocyanate group content of 4.7 mass% with respect to the nonvolatile content. The solution was cooled to 30 ° C., neutralized by adding 34.5 g of a 20% -aqueous sodium hydroxide solution, and then 660 g of water was gradually added to emulsify and disperse. To this emulsified dispersion, 28.3 g of hexamethylenediamine and 3.7 g of diethylenetriamine were added and stirred for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain a polycarbonate-based polyurethane resin aqueous dispersion having a solid content of about 35% by mass.

  The content of carboxyl groups and carboxylate groups derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this aqueous dispersion was 2% by mass.

Comparative Synthesis Example 1 (polycarbonate polyol solid at 20 ° C., COOH group and COO-group content: 2% by mass)
In the same reactor as used in Synthesis Example 1, 137.4 g of poly (1,6-hexamethylenediol carbonate) (average molecular weight 2000, solid at 20 ° C.), 18.1 g of 2,2-dimethylolbutanoic acid Then, dibutyltin dilaurate 0.001 and 85 g of methyl ethyl ketone were added and mixed uniformly. Then, 100.0 g of cyclohexylmethane diisocyanate was added and reacted at 80 ° C. for a predetermined time, and the free isocyanate group content was 4.7 mass% with respect to the nonvolatile content. A methyl ethyl ketone solution of the prepolymer was obtained. This solution was cooled to 30 ° C., neutralized by adding 24.4 g of a 20% aqueous sodium hydroxide solution, and then 470 g of water was gradually added to emulsify and disperse. To this emulsified dispersion, 18.2 g of hexamethylenediamine and 2.4 g of diethylenetriamine were added and stirred for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain a polycarbonate-based polyurethane resin aqueous dispersion having a solid content of about 35% by mass.

  The content of carboxyl groups and carboxylate groups derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this aqueous dispersion was 2% by mass.

Comparative Synthesis Example 2 (Polyester polyol, COOH group and COO-group content: 2% by mass)
In the same reactor as that used in Synthesis Example 1, 137.4 g poly (1,4-butanediol adipate) (average molecular weight 2,000), 18.1 g 2,2-dimethylolbutanoic acid, dibutyltin dilaurate 0.001 and 85 g of methyl ethyl ketone were added and mixed uniformly, and then 100.0 g of cyclohexylmethane diisocyanate was added and allowed to react at 80 ° C. for a predetermined time to give a prepolymer of methyl ethyl ketone having a free isocyanate group content of 4.7% by mass relative to the nonvolatile content. A solution was obtained. The solution was cooled to 30 ° C., neutralized by adding 24.4 g of a 20% aqueous sodium hydroxide solution, and then 460 g of water was gradually added to emulsify and disperse. To this emulsified dispersion, 18.2 g of hexamethylenediamine and 2.4 g of diethylenetriamine were added and stirred for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain a polyester-based polyurethane resin aqueous dispersion having a solid content of about 35% by mass.

  The content of carboxyl groups and carboxylate groups derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this aqueous dispersion was 2% by mass.

Comparative Synthesis Example 3 (Polyether polyol, COOH group and COO-group content: 2% by mass)
137.4 g of polypropylene glycol (average molecular weight of 2,000), 18.1 g of 2,2-dimethylolbutanoic acid, 0.001 of dibutyltin dilaurate and 85 g of methyl ethyl ketone were added to the same reactor as used in Synthesis Example 1. After uniformly mixing, 100.0 g of cyclohexylmethane diisocyanate was added and reacted at 80 ° C. for a predetermined time to obtain a methyl ethyl ketone solution of a prepolymer having a free isocyanate group content of 4.7 mass% with respect to the nonvolatile content. The solution was cooled to 30 ° C., neutralized by adding 24.4 g of a 20% aqueous sodium hydroxide solution, and then 460 g of water was gradually added to emulsify and disperse. To this emulsified dispersion, 18.2 g of hexamethylenediamine and 2.4 g of diethylenetriamine were added and stirred for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain an aqueous polyether polyurethane resin dispersion having a solid content of about 35% by mass.

  The content of carboxyl groups and carboxylate groups derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this aqueous dispersion was 2% by mass.

Example 1
(1) Preparation of Aqueous Coating Agent A for Colored Concealing Layer Aqueous Urethane-Acrylic Copolymer White Ink (Ode KEX White, manufactured by The Inktec Co., Ltd.) 100 parts by mass, water 20 parts by mass, isopropyl alcohol 20 parts by mass The aqueous coating agent A for the colored hiding layer was prepared by mixing the parts.
(2) Preparation of water-based coating agent B for picture pattern layer 40 parts by mass of a polycarbonate-based polyurethane resin aqueous dispersion having a solid content of about 35% by mass obtained in Synthesis Example 1, a quinoxalinedione derivative (Pigment No. PY213) A water-based ink consisting of 5 parts by mass, 30 parts by mass of water and 25 parts by mass of isopropyl alcohol was further mixed with 20 parts by mass of water and 20 parts by mass of isopropyl alcohol to prepare an aqueous coating agent B for a pattern layer.
(3) Preparation of water-based coating agent C for transparent adhesive layer 100 parts by weight of an aqueous polycarbonate polyurethane resin-containing adhesive, 10 parts by weight of a water-dispersible isocyanate cross-linking agent and 10 parts by weight of water are mixed to form a transparent adhesive. Coating agent C for the agent layer was prepared.
(Production of decorative sheet)
A 60 μm colored sheet mainly composed of polypropylene was used as a base sheet, and corona discharge treatment was performed on both the front and back surfaces. After that, the water-based coating agent A for the colored masking layer and the water-based coating agent B for the pattern layer are uniformly applied to the entire surface by the gravure printing method and dried, and then the color masking layer (3 μm) and the pattern layer (1 μm) were sequentially formed.
Subsequently, the aqueous coating agent C for adhesive layer was uniformly apply | coated and dried on it by the gravure printing method, and the transparent adhesive layer (3 micrometers) was formed.

  On the adhesive layer, a transparent polypropylene film having a thickness of 80 μm was laminated by a dry laminate method to form a transparent resin layer.

Example 2
Example 1 except that the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 2 was used in place of the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 1 as the resin for the aqueous coating agent for the pattern layer. A decorative sheet was prepared in the same manner as described above.

Example 3
Example 1 except that the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 3 was used in place of the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 1 as the resin of the aqueous coating agent for the pattern layer. A decorative sheet was prepared in the same manner as described above.

Example 4
Example 1 except that the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 4 was used instead of the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 1 as the resin of the aqueous coating agent for the pattern layer. A decorative sheet was prepared in the same manner as described above.

Example 5
Example 1 except that the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 5 was used instead of the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 1 as the resin of the aqueous coating agent for the pattern layer. A decorative sheet was prepared in the same manner as described above.

Example 6
Example 1 except that the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 6 was used in place of the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 1 as the resin for the aqueous coating agent for the pattern layer. A decorative sheet was prepared in the same manner as described above.

Example 7
Example 1 except that the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 7 was used in place of the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 1 as the resin for the aqueous coating agent for the pattern layer. A decorative sheet was prepared in the same manner as described above.

Example 8
Example 1 except that the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 8 was used in place of the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 1 as the resin of the aqueous coating agent for the pattern layer. A decorative sheet was prepared in the same manner as described above.

Example 9
Example 1 except that the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 9 was used instead of the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 1 as the resin of the aqueous coating agent for the pattern layer. A decorative sheet was prepared in the same manner as described above.

Comparative Example 1
Example 1 except that the polycarbonate-based polyurethane resin aqueous dispersion in Comparative Synthesis Example 1 was used in place of the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 1 as the resin for the aqueous coating agent for the pattern layer. A decorative sheet was produced in the same manner.

Comparative Example 2
Example except that the polyester-based polyurethane resin aqueous dispersion obtained in Comparative Synthesis Example 2 was used instead of the polycarbonate-based polyurethane resin aqueous dispersion obtained in Synthesis Example 1 as the resin of the aqueous coating agent for the pattern layer. A decorative sheet was prepared in the same manner as in Example 1.

Comparative Example 3
Implemented except that the aqueous polyurethane coating resin obtained in Comparative Synthesis Example 3 was used in place of the aqueous polycarbonate polyurethane resin dispersion obtained in Synthesis Example 1 as the resin of the aqueous coating agent for the pattern layer. A decorative sheet was prepared in the same manner as in Example 1.
(Test method)
1. Blocking test The sheet at the time when the colored concealing layer and the pattern layer were sequentially laminated on the base material sheet was used as a test specimen, and the back surface primer side of the base material sheet on which only the separately prepared back surface primer was laminated was superimposed on the surface. The test piece was used as a test specimen and allowed to stand for 24 hours with a blocking tester (load 5 kg / cm ² , 50 ° C., 80%). Then, the blocking state was evaluated by peeling off the overlapped portion of the test specimen removed from the tester.
○: No transfer of ink, no adhesion between sheets Δ: No transfer of ink, slight contact between sheets x: Ink transfer, close response between sheets
2. Adhesion test A sheet at the time when a colored concealing layer and a pattern layer are sequentially laminated on a base material sheet is used as a test body, and 100 mm of 2 mm square grid-like cutter scratches are applied to the surface, and Cellotape (registered trademark) (Nichiban) 24 mm) was attached to the surface of the test specimen and peeled off in the vertical direction. It was observed whether the pattern layer was peeled off from the decorative sheet.
A: Ink of 5 squares or less is taken. ○: Ink of 6 squares or more and 10 squares or less is taken. Δ: Ink of 11 squares or more, 50 squares or less is taken. X: Ink of 51 squares or more is taken.
3. Using a super accelerated weathering tester (“I Super UV Tester”, manufactured by Iwasaki Electric Co., Ltd.), the test specimen is a sheet at the time when a colored concealment layer and a pattern layer are sequentially laminated on a weather resistance adhesion test substrate sheet. The temperature was 63 ° C. and the humidity was 50% RH. Thereafter, a super accelerated weather resistance test was performed by repeating a cycle of irradiating light with an illuminance of 60 mW / cm ² (365 nm) on the sheet for 20 hours and then allowing the sheet to condense for 4 hours for 200 hours. During the test, pure water was showered for 30 seconds when switching between irradiation and condensation. After the test, the transparent resin layer on the surface of the test body was removed, and the adhesion of the test body was evaluated by the same method as the above adhesion.
○: Ink of 10 squares or less is taken Δ: Ink of 11 squares or more and 50 squares or less is taken x: Ink of 51 squares or more is taken out
4). Weathering fading test A sheet of a color concealment layer, a pattern layer, an adhesive layer, and a transparent resin layer sequentially laminated on a base material sheet was used as a test body, and the above super accelerated weathering test was repeated for 200 hours before and after the accelerated test. The change in color difference (ΔE) of the test specimen was measured with X-Rite 938 (manufactured by X-Rite).
○: ΔE is 2 or less (grayscale grade 4 or more)
Δ: ΔE is greater than 2 and less than or equal to 6 (grayscale grade 4 to 2)
X: ΔE exceeds 6 (grayscale grade 2 or less)
5. A transparent PET film having a thickness of 75 μm (manufactured by Teijin DuPont Films, Ltd., HS74) was used as a substrate sheet for evaluating haze . An aqueous coating agent B for the pattern layer was uniformly applied on the base sheet by a gravure printing method and dried to form a pattern layer (thickness 1 μm) of 1 g / m ² .
The haze value of the resulting pattern / pattern layer forming sheet was measured by a direct reading haze computer HGM-2DP (manufactured by Suga Test Instruments Co., Ltd.).
○: Haze value is 40 or less ×: Haze value exceeds 40 Each evaluation result is summarized in Table 1 below.

Claims (7)

A decorative sheet in which at least a colored hiding layer, a pattern pattern layer, a transparent adhesive layer and a transparent resin layer are formed in this order on a base sheet,
The base sheet includes polypropylene,
The colored hiding layer is formed of a water-based ink containing a urethane-acrylic copolymer,
The pattern layer is formed of a water-based ink containing a polycarbonate-based polyurethane resin obtained by reacting a raw material mixture containing a polyisocyanate and a polyfunctional compound containing a polycarbonate polyol that is liquid at 20 ° C. ,
The polycarbonate-based polyurethane resin has an acidic group and / or an anionic group obtained by neutralizing the acidic group, and the content of the acidic group and the anionic group is that of the polycarbonate-based polyurethane resin. 1 to 4% by mass,
The transparent adhesive layer is formed of an aqueous composition containing a polycarbonate-based polyurethane resin,
The transparent resin layer includes polypropylene,
A decorative sheet characterized by that. The polycarbonate-based polyurethane resin contained in the pattern layer has an anionic group obtained by neutralizing an acidic group using at least one selected from the group consisting of an inorganic base and an alkanolamine. The decorative sheet according to 1.   The decorative sheet according to claim 1 or 2, wherein the water-based ink has a polycarbonate polyurethane resin dispersed in a dispersion medium containing water.   The decorative sheet according to any one of claims 1 to 3, wherein the acidic group is at least one selected from the group consisting of a carboxyl group and a sulfonic acid group.   The decorative sheet according to any one of claims 1 to 4, wherein the polyisocyanate is a non-yellowing polyisocyanate.   The decorative sheet according to any one of claims 1 to 5, wherein a colored hiding layer, a pattern pattern layer, a transparent adhesive layer, a transparent resin layer, and a transparent surface protective layer are sequentially laminated on the base sheet. .   A decorative board obtained by laminating the decorative sheet according to any one of claims 1 to 6 and an adherend.