JP2007118584A - Decorative sheet - Google Patents

Abstract

The present invention provides a decorative sheet having a surface protective layer excellent in friction resistance, stain resistance, adhesion to polyolefin resins and blocking properties.
A polyurethane resin aqueous dispersion and a polyisocyanate aqueous dispersion are blended in a predetermined amount. The polyurethane resin aqueous dispersion comprises a polyester polyol (A), a chain extender (B), and a compound (C ) And an organic polyisocyanate (D), a transparent surface formed from an aqueous polyurethane resin composition obtained by emulsifying a urethane prepolymer obtained by cross-linking with a polyamine (E) A decorative sheet having a protective layer.
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Description

  The present invention relates to a decorative sheet.

  In recent years, with the increasing awareness of the environment, conversion from polyvinyl chloride to polyolefin resins such as polypropylene and polyethylene is progressing as a base sheet for decorative sheets.

  Since the polyolefin resin has insufficient friction resistance as compared with polyvinyl chloride, a surface protective layer is often further provided on the outermost surface layer of the decorative sheet.

  As a coating agent used for forming the surface protective layer, a solvent-based coating agent has been conventionally used. However, in recent years, there has been a strong demand for using an aqueous coating agent that does not use an organic solvent as much as possible.

  For example, an aqueous coating agent using an aqueous acrylic resin is known (Patent Document 1).

  However, the water-based acrylic resin-based aqueous coating agent tends to be inferior in the friction resistance of the surface protective layer and the adhesion to the polyolefin-based resin as compared with the solvent-based coating agent.

  On the other hand, in order to improve the said fault, it has been proposed to use an aqueous acrylic-urethane copolymer composition as an aqueous coating agent (Patent Document 2). The surface protective layer made of the aqueous acrylic-urethane copolymer composition has improved friction resistance and adhesion to polyolefin resins.

  However, the surface protective layer made of the aqueous acrylic-urethane copolymer composition cannot be said to have sufficient blocking properties. That is, there is a problem that when the decorative sheet is wound up, the surface protective layer adheres to the adjacent layer.

Moreover, the surface protective layer which consists of the said water-based acrylic resin or a water-based acrylic-urethane copolymer composition is inadequate also from a contamination-resistant viewpoint.
Japanese Patent Laid-Open No. 9-158098 JP 2000-119362 A

  An object of the present invention is to provide a decorative sheet having a surface protective layer excellent in friction resistance, stain resistance, adhesion to polyolefin resins, and blocking properties.

  As a result of intensive studies, the present inventors can achieve the above object when a surface protective layer is formed from a specific aqueous polyurethane resin composition containing a polyurethane resin aqueous dispersion and a polyisocyanate aqueous dispersion. As a result, the present invention has been completed.

  That is, the present invention relates to the following decorative sheet.

1. A decorative sheet having a transparent surface protective layer formed from an aqueous polyurethane resin composition,
In the aqueous polyurethane resin composition, the polyurethane resin aqueous dispersion and the polyisocyanate aqueous dispersion have a solid content of 10 to 80 parts by weight based on 100 parts by weight of the solid content of the polyurethane resin aqueous dispersion. It is blended so that
The polyurethane resin aqueous dispersion emulsifies a urethane prepolymer obtained by reacting a polyester polyol (A), a chain extender (B), a compound (C), and an organic polyisocyanate (D) to form a polyamine (E). Cross-linked by
The polyester polyol (A) has a number average molecular weight of 500 to 5,000, is composed of an acid component and a glycol component, and contains 35% by weight or more of an aromatic dicarboxylic acid and / or an alicyclic dicarboxylic acid as the acid component. And
The chain extender (B) is a polyol having an aromatic ring and / or an alicyclic polyol having a number average molecular weight of less than 500,
The compound (C) has an anionic hydrophilic group and at least two active hydrogens in the molecule,
The polyamine (E) has two or more amino groups in the molecule.
A decorative sheet characterized by that.

  2. In item 1, the compound (C) has a carboxyl group and at least two active hydrogens in the molecule, and the acid value as the carboxyl group content of the aqueous polyurethane resin composition is 3 to 15 mgKOH / g. The decorative sheet as described.

  3. Item 3. The decorative sheet according to Item 1 or 2, wherein the organic polyisocyanate (D) is an alicyclic diisocyanate, and the urethane prepolymer contains 30 to 50% by weight of the alicyclic diisocyanate.

  4). The decorative sheet according to claims 1 to 3, wherein the aqueous polyurethane resin composition further contains an ultraviolet absorber, and the content thereof is 1 to 10% by weight in the solid content of the aqueous polyurethane resin composition.

  5. The decorative sheet according to any one of claims 1 to 4, wherein the ultraviolet absorber is added before emulsifying the urethane prepolymer.

  6). The decorative sheet according to claim 4, wherein the aqueous polyurethane resin composition further contains a hindered amine light stabilizer.

  7). Item 7. The decorative sheet according to any one of Items 1 to 6, wherein the aqueous polyurethane resin composition further contains polyethylene particles having a molecular weight of 2500 to 8000.

  8). Item 8. The decorative sheet according to any one of Items 1 to 7, wherein the decorative sheet has a configuration in which a base sheet, a decorative layer, an adhesive layer, a transparent resin layer, and a transparent surface protective layer are sequentially laminated.

9. Item 9. The decorative sheet according to Item 8, wherein the base sheet and the transparent resin layer contain a polyolefin resin as a resin component.

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

The decorative sheet of the present invention is a decorative sheet having a transparent surface protective layer formed from an aqueous polyurethane resin composition,
In the aqueous polyurethane resin composition, the polyurethane resin aqueous dispersion and the polyisocyanate aqueous dispersion have a solid content of 10 to 80 parts by weight based on 100 parts by weight of the solid content of the polyurethane resin aqueous dispersion. It is blended so that
The polyurethane resin aqueous dispersion emulsifies a urethane prepolymer obtained by reacting a polyester polyol (A), a chain extender (B), a compound (C), and an organic polyisocyanate (D) to form a polyamine (E). Cross-linked by
The polyester polyol (A) has a number average molecular weight of 500 to 5,000, is composed of an acid component and a glycol component, and contains 35% by weight or more of an aromatic dicarboxylic acid and / or an alicyclic dicarboxylic acid as the acid component. And
The chain extender (B) is a polyol having an aromatic ring and / or an alicyclic polyol having a number average molecular weight of less than 500,
The compound (C) has an anionic hydrophilic group and at least two active hydrogens in the molecule,
The polyamine (E) has two or more amino groups in the molecule.
It is characterized by that.

Aqueous polyurethane resin composition In the aqueous polyurethane resin composition, the polyurethane resin aqueous dispersion and the polyisocyanate aqueous dispersion have a solid content of 10% by weight based on 100 parts by weight of the solid content of the polyurethane resin aqueous dispersion. It is mix | blended so that it may become -80 weight part.

  The polyurethane resin aqueous dispersion emulsifies a urethane prepolymer obtained by reacting a polyester polyol (A), a chain extender (B), a compound (C) and an organic polyisocyanate (D), and the polyamine (E ).

≪Polyester polyol (A) ≫
Examples of the aromatic dicarboxylic acid as an acid component constituting the polyester polyol (A) include, for example, isophthalic acid, terephthalic acid, orthophthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, and 2,6-naphthalene. Examples thereof include dicarboxylic acid, biphenyldicarboxylic acid, tetrahydrophthalic acid and the like, or reactive derivatives thereof such as acid anhydrides, alkyl esters, and acid halides. These aromatic dicarboxylic acids can be used alone or in combination of two or more.

  Examples of the alicyclic dicarboxylic acid of the acid component constituting the polyester polyol (A) include, for example, water additions of the aromatic dicarboxylic acid, or reactive derivatives such as acid anhydrides, alkyl esters, acid halides, and the like. Can be mentioned. These alicyclic dicarboxylic acids can be used alone or in combination of two or more.

  Examples of other acid components constituting the polyester polyol (A) include malonic acid, succinic acid, tartaric acid, oxalic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, alkyl succinic acid, Examples thereof include aliphatic dicarboxylic acids such as linolenic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, and itaconic acid, and reactive derivatives such as acid anhydrides, alkyl esters, and acid halides. These aliphatic dicarboxylic acids can be used alone or in combination of two or more.

  The polyester polyol (A) contains 35% by weight or more of an aromatic dicarboxylic acid and / or an alicyclic dicarboxylic acid as an acid component.

  When the content ratio of the aromatic dicarboxylic acid and / or alicyclic dicarboxylic acid is less than 35% by weight, the formed transparent surface protective layer becomes soft, and there is a possibility that blocking occurs during winding of the decorative sheet.

  The aromatic dicarboxylic acid is preferably isophthalic acid, terephthalic acid, orthophthalic acid or the like.

  Moreover, as an alicyclic dicarboxylic acid, cyclohexane dicarboxylic acid etc. are preferable.

  The aromatic dicarboxylic acid and the alicyclic dicarboxylic acid can be used alone or in combination.

  Examples of the glycol component constituting the polyester polyol (A) include ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 1,6-hexamethylene glycol, diethylene glycol and the like. Linear glycol or 1,2-propylene glycol, 1-methyl-1,3-butylene glycol, 2-methyl-1,3-butylene glycol, neopentyl glycol, 1-methyl-1,4-pentanediol, 2- Methyl-1,4-pentanediol, 1,2-dimethyl-neopentyl glycol, 2,3-dimethyl-neopentyl glycol, 1-methyl-1,5-pentanediol, 2-methyl-1,5-pentanediol 3-methyl-1,5-pentanediol, 1,2 Dimethyl butylene glycol, 1,3-dimethyl-butylene glycol, 2,3-dimethyl butylene glycol, and the like can be given branch glycols such as 1,4-dimethyl-butylene glycol. These linear glycols or branched glycols can be used alone or in combination of two or more.

  The polyester polyol (A) is obtained by a method similar to a known polyester production method in which the acid component and the glycol component are dehydrated and condensed.

  The number average molecular weight of the polyester polyol (A) is 500 to 5000, preferably 1000 to 4000, more preferably 1500 to 3000.

  When the number average molecular weight is less than 500, the transparent surface protective layer formed from the aqueous polyurethane resin composition is hard and brittle, and the adhesion is lowered. On the other hand, when the number average molecular weight exceeds 5000, the transparent surface protective layer formed from the aqueous polyurethane resin composition becomes soft, and the blocking property is lowered.

  The number average molecular weight is measured by the method described in the examples.

≪Chain extender (B) ≫
The chain extender (B) is a polyol having an aromatic ring and / or an alicyclic polyol, and has a number average molecular weight of less than 500.

  Examples of the polyol having an aromatic ring include bisphenol A, bisphenol F, and bisphenol S.

  Examples of the alicyclic polyol include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol S, and the like.

  These chain extenders (B) can be used alone or in combination of two or more.

  The chain extender (B) has a number average molecular weight of less than 500. The number average molecular weight is preferably 116 to less than 500.

  When the number average molecular weight is 500 or more, the adhesion of the transparent surface protective layer tends to be lowered.

≪Compound (C) ≫
Examples of the compound (C) having an anionic hydrophilic group and at least two active hydrogens in the molecule include compounds having a carboxyl group and at least two active hydrogens in the molecule. Examples of the compound having a carboxyl group and at least two active hydrogens in the molecule include dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolacetic acid, dimethylolvaleric acid and the like.

  These compounds can be used alone or in combination of two or more.

  Compound (C) has the effect of facilitating the dispersibility of the urethane prepolymer in water and improving the adhesion to substrates such as decorative panels and wallpaper.

  The aqueous polyurethane resin composition preferably has an acid value of 3 to 15 mgKOH / g, more preferably 7 to 12 mgKOH / g, as the carboxyl group content in the aqueous polyurethane resin composition.

  When the acid value is less than 3 mgKOH / g, there is a problem that dispersibility in water becomes difficult.

  Moreover, when an acid value exceeds 15 mgKOH / g, there exists a problem that stain resistance falls and a stain | pollution | contamination becomes difficult to remove.

  The acid value is measured by the method described in the examples.

≪Organic polyisocyanate (D) ≫
Examples of the organic polyisocyanate (D) include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and araliphatic polyisocyanates.

  Aliphatic polyisocyanates include tetramethylene diisocyanate, dodecamethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1 , 5-diisocyanate, 3-methylpentane-1,5-diisocyanate and the like.

  Examples of the alicyclic polyisocyanate include isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, and the like. Can be mentioned.

  Aromatic polyisocyanates include tolylene diisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 4,4′-dibenzyl diisocyanate, 1,5 -A naphthylene diisocyanate, a xylylene diisocyanate, a 1, 3- phenylene diisocyanate, a 1, 4- phenylene diisocyanate etc. can be mentioned.

  Examples of the araliphatic polyisocyanate include dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, α, α, α, α-tetramethylxylylene diisocyanate, and the like.

  Moreover, modified bodies, such as a dimer, a trimer of these organic polyisocyanates, and a buret-ized isocyanate, can be mentioned. These can be used alone or in combination of two or more.

  The organic polyisocyanate (D) is preferably an alicyclic polyisocyanate from the viewpoint of weather resistance. Specifically, 4,4′-dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanate methyl) A cyclohexane etc. can be mentioned.

  The organic polyisocyanate is preferably contained in the urethane prepolymer in an amount of 30 to 50% by weight, more preferably 33 to 45% by weight, and particularly preferably 37 to 45% by weight.

  If content of organic polyisocyanate is less than 30 weight%, there exists a problem that blocking property falls.

  Moreover, when content of organic polyisocyanate exceeds 50 weight%, the film forming temperature in the case of coating will become high too much, and it will become difficult to form a membrane | film | coat. Moreover, there exists a problem that the softness | flexibility of a film | membrane lose | disappears and damage prevention property falls.

≪Polyamine (E) ≫
Polyamine (E) is a compound having two or more amino groups in the molecule.

  Examples of the polyamine (E) include ethylenediamine, propylenediamine, dipropylenetriamine, diethylenetriamine, isophoronediamine, metaxylenediamine, hydrazine, and adipic acid dihydrazide.

  The polyamine (E) functions as a chain-extending amine for polymerizing a urethane prepolymer into a three-dimensional network structure.

≪Manufacture of polyurethane resin aqueous dispersion≫
The polyurethane resin aqueous dispersion can be produced by a known method. For example, a one-shot method in which each component is added and reacted at one time, or other, after reacting an organic polyisocyanate with a part of the active hydrogen compound to form a prepolymer having an isocyanate group at the terminal, the remainder of the active hydrogen compound And the like, and a multi-stage method in which the reaction is further carried out. Also, a method for producing a polyurethane resin aqueous dispersion by reacting in an organic solvent that is inert with respect to the organic polyisocyanate and compatible with water using the above method, adding water after the reaction, and removing the organic solvent But you can.

  In the production of the polyurethane resin aqueous dispersion, first, an organic polyisocyanate (D), a polyester polyol (A), and a compound (C) are reacted in an organic solvent that is inert to isocyanate and compatible with water. After forming a prepolymer having an isocyanate group at the terminal, a chain extender (B) is further reacted to form a urethane prepolymer having an isocyanate group at the terminal.

  Next, for example, a method in which the urethane prepolymer is neutralized with a neutralizing agent and then emulsified and cross-linked with a polyamine (E). The urethane prepolymer is neutralized and emulsified with water containing a neutralizing agent to obtain a polyamine (E). A polyurethane resin aqueous dispersion is produced by a method of cross-linking by, for example. Here, the emulsification includes stable dispersion of the resin in water.

  Suitable surfactants such as anionic surfactants represented by higher fatty acids, resin acids, acidic fatty alcohols, sulfate esters, higher alkyl sulfonic acids, alkyl aryl sulfonic acids, sulfonated castor oil, sulfosuccinic acid esters, etc. Or you may emulsify together using the nonionic surfactant etc. which are represented by the well-known reaction product of ethylene oxide, long-chain fatty alcohol, or phenols.

  The urethane prepolymer is usually produced at a temperature of 20 to 140 ° C., preferably 40 to 120 ° C., using (A) to (D). In order to accelerate the reaction, a catalyst used in a normal urethane reaction may be used if necessary. Examples of the urethane reaction catalyst include amine catalysts (for example, triethylamine, N-ethylmorpholine, triethylenediamine, etc.), tin-based catalysts (for example, dibutyltin dilaurate, dioctyltin dilaurate, tin octylate, etc.), titanium-based catalysts (for example, Tetrabutyl titanate).

  The amount of the catalyst used is usually 0.1% by weight or less in the urethane prepolymer.

  Examples of organic solvents that are inert with respect to organic polyisocyanate and are compatible with water include ester solvents (eg, ethyl acetate, butyl acetate, ethyl cellosolve acetate), ketone solvents (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone). Etc.), ether solvents (for example, dioxane, tetrahydrofuran, propylene glycol dimethyl ether, etc.) and amide solvents (for example, dimethylformamide, N-methylpyrrolidone, etc.). These solvents can be used alone or in combination of two or more.

  Of these, ethyl acetate, methyl ethyl ketone, acetone, and tetrahydrofuran are preferred.

  As the neutralizing agent, alkali metal salts such as sodium hydroxide and potassium hydroxide, trimethylamine, triethylamine, tri-n-propylamine, tributylamine, triethanolamine, ammonia and the like can be used.

  In order to suppress the generation of outgas, it is preferable to use an alkali metal salt such as sodium hydroxide or potassium hydroxide.

  These neutralizing agents can be used alone or in combination of two or more.

  Examples of the polyisocyanate aqueous dispersion include a modified isocyanurate of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Aquanate 100, Aquanate 200 or Sumitomo Bayer Urethane Co., Ltd., trade name: Baye Joule 310), an adduct modified product of hexamethylene diisocyanate (Asahi Kasei Kogyo Co., Ltd., trade name: Duranate WB40-80D) and the like.

≪Water-based polyurethane resin composition≫
The aqueous polyurethane resin composition includes a polyurethane resin aqueous dispersion and a polyisocyanate aqueous dispersion.

  The aqueous polyurethane resin composition is blended so that the solid content of the polyisocyanate aqueous dispersion is 10 to 80 parts by weight with respect to 100 parts by weight of the solid content of the polyurethane resin aqueous dispersion, preferably polyurethane resin water. It mix | blends so that the solid content of a polyisocyanate aqueous dispersion may be 20-60 weight part with respect to 100 weight part of solid content of a dispersion.

  When the solid content of the polyisocyanate aqueous dispersion is less than 10 parts by weight, there is a problem that the adhesion to a base material such as a decorative board or wallpaper is lowered.

  Further, when the solid content of the polyisocyanate aqueous dispersion exceeds 80 parts by weight, the transparent surface protective layer formed from the aqueous polyurethane resin composition becomes soft, and the blocking property is lowered during winding after coating. There is a problem.

In addition, solid content means the part which remove | excludes a water | moisture content from a polyurethane resin water dispersion and a polyisocyanate water dispersion,
Aqueous polyurethane resin compositions include UV absorbers, pigments and dyes, water for viscosity adjustment, dispersion stabilizers, thixotropic agents, antioxidants, antifoaming agents, thickeners, dispersants, surfactants, Additives such as catalysts, fillers, lubricants, antistatic agents, hindered amine light stabilizers, film-forming aids, and the like can also be added.

  The solid content in the aqueous polyurethane resin composition (including additives) is not limited, but is preferably about 10 to 60% by weight, and more preferably about 20 to 40% by weight.

  In the solid content of the aqueous polyurethane resin composition, preferably 1 to 10% by weight of an ultraviolet absorber is added, and more preferably 2 to 7% by weight.

  The ultraviolet absorber has an effect of improving the weather resistance of the coating film.

  Examples of the ultraviolet absorber include salicylic acid ester-based, benzophenone-based, benzotriazole-based, and acrylonitrile-based compounds.

  Here, solid content means the part which remove | excludes a water | moisture content from aqueous polyurethane resin composition.

  The time when the ultraviolet absorber is added to the aqueous polyurethane resin composition of the present embodiment is preferably before emulsification of the urethane prepolymer. Specifically, it is added when a urethane prepolymer is produced from the polyester polyol (A), the chain extender (B), the compound (C), and the organic polyisocyanate (D).

  According to this method, when the urethane prepolymer is emulsified, the ultraviolet absorber is taken into the emulsion, so that the ultraviolet absorber is less likely to bleed than the coating film when coated with the aqueous polyurethane resin composition. The weather resistance is improved.

  It is preferable that an aqueous polyurethane resin composition contains a ultraviolet absorber and a hindered amine light stabilizer simultaneously among the said additives. By using these two components in combination, superior weather resistance can be imparted to the decorative sheet as compared with the case where each component is used alone.

  Preferred examples of the hindered amine light stabilizer include CHIMASSORB 119FL, CHIMASSORB 944LD, tinuvin 622LD, tinuvin 123, and tinuvin 144 manufactured by Ciba Specialty Chemicals. The addition amount of the hindered amine light stabilizer is preferably about 1 to 10% by weight in the solid content of the aqueous polyurethane resin composition.

  Among the additives, the film-forming aid is not limited, but examples thereof include alkylene glycol ethers such as texanol, N-methyl-2-pyrrolidone, diethylene glycol n-monobutyl ether, dipropylene glycol monoethyl ether, and diethylene glycol. Examples include alkylene glycol ether esters such as n-monobutyl ether acetate and dipropylene glycol monomethyl ether acetate, and one or more of these can be used. The addition amount is preferably 10% by weight or less, more preferably 5% by weight or less, based on the aqueous polyurethane resin composition. Moreover, when it exceeds 10 weight%, there exists a problem that a film-forming aid remains in a decorative sheet and stain resistance deteriorates. The film-forming aid added to the present invention is preferably a propylene glycol ether from the viewpoint of low odor and low toxicity. Specifically, from the viewpoint of non-VOC, tripropylene glycol mono-n- having a boiling point exceeding 260 ° C. Butyl ether is particularly preferred.

  Further, for the purpose of improving the weather resistance and scratch resistance of the surface protective layer, polyethylene particles may be added to the aqueous polyurethane resin composition. The polyethylene particles preferably have a molecular weight of about 2500 to 8000, more preferably about 2500 to 4000. The particle shape of the polyethylene particles is not limited, and may be spherical or irregular. The average particle diameter of the polyethylene particles is not limited, but is preferably about 1 to 5 μm, and more preferably about 1 to 3 μm.

  The blending amount of the polyethylene particles is not limited, but is preferably about 0.4 to 18 parts by weight and more preferably about 4 to 10 parts by weight with respect to 100 parts by weight of the polyurethane resin contained in the aqueous polyurethane resin composition. .

When the polyethylene particles are blended, so-called polyethylene wax containing polyethylene particles having the molecular weight can be preferably used. The polyethylene wax is not particularly limited, and for example, those obtained by dispersing the above-described molecular weight polyethylene particles in water or an aqueous medium, and those containing a preservative or a rust preventive agent as necessary can be used. The surface of the polyethylene particles may be surface-modified so that the terminal group becomes (COO ⁻ ) in order to improve dispersibility in the wax. The content of polyethylene particles in such a polyethylene wax is not limited, but in the case of an aqueous dispersion, it is about 40% by weight.

  Moreover, although melting | fusing point (softening point) of polyethylene wax is not limited, It is preferable that it is about 90-132 degreeC, and it is more preferable that it is 115-125 degreeC. In addition, melting | fusing point is the value which formed the dry coating film (plate-shaped sample) of the water dispersion type polyethylene wax, and measured melting | fusing point of the sample.

Decorative sheet The decorative sheet of the present invention has a transparent surface protective layer formed from the aqueous polyurethane resin composition.

  The specific configuration of the decorative sheet is not limited. For example, 1) a configuration in which a base sheet, a decorative layer, and a transparent surface protective layer are sequentially stacked, and 2) a configuration in which a base sheet, a decorative layer, an adhesive layer, a transparent resin layer, and a transparent surface protective layer are sequentially stacked. 3) The structure etc. which have a decoration layer in the back surface of a transparent base material sheet, and laminated | stacked the transparent surface protection layer on the front surface of the base material sheet are mentioned. Further, a) a structure in which a paper-based substrate (backing paper), a foamed resin layer, (decoration layer), and a transparent surface protective layer are laminated, b) a paper-based substrate (backing paper), a foamed resin layer, (decoration layer) Moreover, the structure of the decorative sheet suitable for wallpaper use, such as a structure in which a transparent resin layer and a transparent surface protective layer are laminated, is also included.

  Since the transparent surface protective layer has high adhesion to the polyolefin resin, the layer adjacent to the transparent surface protective layer (for example, a base sheet, a transparent resin layer, etc.) contains a polyolefin resin as a resin component. It is preferable to do. In the configuration of 1), a decorative layer is interposed between the base sheet and the transparent surface protective layer. Even in this case, the base sheet preferably contains a polyolefin resin as a resin component.

  Examples of the polyolefin resin include polyethylene, polypropylene (stretched polypropylene or unstretched polypropylene), polybutene, polymethylpentene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene. -A propylene-butene copolymer, a polyolefin-type thermoplastic elastomer, etc. are mentioned. In addition, polyester films (stretched polyethylene terephthalate film, etc.), nylon films (stretched nylon film, unstretched nylon film, etc.), etc. can be used. In addition, the film which gave surface treatments, such as a corona discharge process, can also use preferably these resin films. Among these, a stretched polypropylene film and an unstretched polypropylene film subjected to surface treatment such as corona discharge treatment can be more preferably used.

  Adhesion can be improved by surface treatment such as corona discharge treatment.

  The method for forming the transparent surface protective layer is not limited. For example, the transparent surface protective layer can be formed by applying and drying the aqueous polyurethane resin composition on an adjacent layer (for example, a base sheet, a transparent resin layer, etc.). The coating method is not particularly limited, and can be performed using a known coating apparatus, for example, a roll coater, a reverse roll coater, a gravure coater, a knife coater, or the like.

  The coating amount can be appropriately selected depending on the purpose.

  Aqueous polyurethane resin composition is a coating film (transparent surface protective layer) that has excellent adhesion, stain resistance, blocking resistance, weather resistance, abrasion resistance, etc. to stretched polypropylene film that is a difficult-to-adhere substrate. )give.

  Hereinafter, each layer of the decorative sheet will be described by taking as an example the configuration of 2) above (a configuration in which a base sheet, a decorative layer, an adhesive layer, a transparent resin layer, and a transparent surface protective layer are sequentially laminated).

≪Base material sheet≫
As the base sheet, in addition to those containing the polyolefin resin as a resin component, those containing other resins can also be used. Moreover, a base material sheet is not limited to a resin containing sheet, A paper-like base material is also mentioned.

  The base material sheet may be colored. For example, it can be colored by adding a colorant (pigment or dye) to the resin component. As the colorant, for example, inorganic pigments such as titanium dioxide, carbon black and iron oxide, organic pigments such as phthalocyanine blue, and various dyes can be used. These can be selected from one or more known or commercially available ones. Further, the addition amount of the colorant may be appropriately set according to the desired color tone.

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

  Although the thickness of a base material sheet can be suitably set with the use of a final product, a usage method, etc., generally it is preferable to set it as 50-250 micrometers.

≪Decoration layer≫
The decorative layer (design pattern layer) imparts design properties to the decorative sheet. Examples of the design pattern include a wood grain pattern, a stone pattern, a grain pattern, a tiled pattern, a brickwork pattern, a cloth pattern, a leather pattern, a geometric figure, a character, a symbol, and an abstract pattern. The pattern can be selected according to the type of foam wallpaper.

  The decorative layer is formed, for example, by printing a pattern on the front surface or the back surface of the base sheet. A colored hiding layer (so-called solid ink layer) may be further provided as a part of the decorative layer.

  Examples of printing methods include gravure printing, flexographic printing, silk screen printing, and offset printing. As the printing ink, a known printing ink containing a colorant, a vehicle, and a solvent can be used.

  As the printing ink, an ink containing a colorant and a binder can be generally used. The ink binder may be appropriately selected from known or commercially available products depending on the material of the base sheet. In the present invention, the type of printing ink is not limited, but it is desirable to use an aqueous composition. As the aqueous composition, a composition in which a coloring material is blended in an aqueous binder can be used. As the aqueous binder, known or commercially available resin aqueous solutions, aqueous resin emulsions, and the like can be used. Resins used for these aqueous binders include polyester, polyacrylate, polyvinyl acetate, polybutadiene, polyvinyl chloride, chlorinated polypropylene, polyethylene, polystyrene, polystyrene-acrylate in addition to the above-mentioned hydrophilic polyester-based urethane resins. Copolymers, rosin derivatives, alcohol adducts of styrene-maleic anhydride copolymers, cellulose resins, and the like can also be used in combination. More specifically, for example, polyacrylamide resins, poly (meth) acrylic resins, polyethylene oxide resins, poly N-vinyl pyrrolidone resins, water-soluble polyester resins, water-soluble polyamide resins, water-soluble amino acids. Also usable are water-based resins, water-soluble phenolic resins, other water-soluble synthetic resins; water-soluble natural polymers such as polynucleotides, polypeptides, polysaccharides, and the like. Further, for example, natural rubber, synthetic rubber, polyvinyl acetate resin, (meth) acrylic resin, polyvinyl chloride resin, polyurethane-polyacrylic resin modified or mixed resin, and other resins can be used. One or more of the above resins are used. In addition, (meth) acrylic monomers such as acrylic acid esters, methacrylic acid esters, hydroxyethyl acrylate, hydroxyethyl methacrylate; nitrile monomers such as acrylonitrile and methacrylonitrile; amide monomers such as acrylamide and methacrylamide; amides thereof N-alkoxy substituted monomers and N-methylol substituted monomers; styrene monomers such as styrene, vinyl toluene, α-methyl styrene, divinyl benzene; allylic monomers such as diallyl phthalate, allyl glycidyl ether, triallyl isocyanurate; Monomers having a polymerizable double bond such as vinyl acetate and N-vinyl pyrrolidone; one or more of these, and acrylic acid, methacrylic acid, maleic acid, maleic anhydride having a carboxyl group It is acid, fumaric acid, itaconic acid, also possible to use one type or alkali solution-soluble (meth) acrylic copolymer comprising a copolymer of more unsaturated carboxylic acids other like. These can use 1 type (s) or 2 or more types.

  Moreover, a well-known coloring material can be used for a coloring material. For example, titanium white, zinc white, petal, vermilion, ultramarine blue, cobalt blue, titanium yellow, carbon black and other inorganic pigments, isoindolinone, Hansa Yellow A, quinacridone, permanent red 4R, phthalocyanine blue, indanthrene blue RS, Examples thereof include organic pigments (including dyes) such as aniline black, metal pigments such as aluminum and brass, pearlescent pigments made of foil powder such as titanium dioxide-coated mica and basic lead carbonate, and the like. These can be used alone or in combination of two or more.

  The thickness of the decoration layer is different from the kind of pattern, but is preferably about 0.1 to 10 μm.

≪Adhesive layer≫
The adhesive layer exists between the decorative layer and the transparent resin layer. The adhesive used in the adhesive layer can be appropriately selected from known adhesives according to the components constituting the decorative layer or the transparent resin layer. For example, various adhesives such as polyurethane resin, polyacrylic resin, polycarbonate resin, and epoxy resin can be used. In addition to the reactive curing type, any type of adhesive such as a hot melt type, an ionizing radiation curing type, and an ultraviolet curing type may be used.

  What is necessary is just to implement as an adhesion | attachment method according to a well-known method according to the kind etc. of adhesive agent to be used. For example, using a polyolefin resin such as polyethylene or polypropylene, a method of coating on a decorative layer by melt extrusion (extrusion coating method), a thermosetting resin such as a polyester resin, a polyurethane resin, an epoxy resin, or the like. Apply an adhesive to which a crosslinking agent such as amine, a polymerization initiator such as methyl ethyl ketone peroxide, hydroperoxide, azabisisobutyronitrile, or a polymerization accelerator such as cobalt naphthenate or dimethylaniline is added if necessary. A dry laminating method can be adopted. Alternatively, an adhesive capable of thermocompression bonding may be used, and the decoration layer and the transparent resin layer may be laminated by thermocompression bonding.

  The adhesive layer is preferably formed of an aqueous composition in that the effect of reducing VOC and the like is 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 addition, as needed, well-known easy adhesion processes, such as a corona discharge process, a plasma process, a degreasing process, and a surface roughening process, can also be given to an adhesion surface.

  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 component contained in the transparent resin layer include polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, and ethylene / acrylic. Examples include acid ester copolymers, ionomers, polymethylpentene, acrylic acid esters, methacrylic acid esters, polycarbonates, and cellulose triacetates. Among these, polyolefin resins such as polypropylene are particularly preferable from the viewpoint of adhesion of the transparent surface protective layer.

  In 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 (for example, as necessary) 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 150 μm.

  The method for producing the decorative sheet described above (method for forming each layer) is not limited, and printing by gravure printing, flexographic printing, silk screen printing, offset printing, transfer printing, etc .; application by spraying, rollers, brushes, etc .; Any of lamination of things can be adopted. In consideration of environmental performance, the decorative sheet preferably has each layer formed by a coating film made of an aqueous composition.

  Such a decorative sheet of the present invention can be applied to various surface protections and decorations such as buildings and interior members. Specific applications of decorative sheets include interior decorations for buildings such as walls, ceilings and floors, surface decorations for furniture such as window frames, doors, and handrails, surface decorations for furniture or cabinets for light electrical / OA equipment, automobiles, trains, etc. Applications include vehicle interiors, aircraft interiors, and window glass makeup. It can also be applied as a general wallpaper used for decorative purposes on the building wall.

  Since the decorative sheet of the present invention has the specific transparent surface protective layer, the decorative sheet surface is excellent in friction resistance, stain resistance, adhesion to polyolefin resins and blocking properties.

  Such a decorative sheet of the present invention can be used as a surface decoration for various members, and can also be applied as a general wallpaper used as a decoration for a building wall surface.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to the examples.
(Measuring method of hydroxyl value)
The hydroxyl value was measured according to JIS K1557-1970.
(Number average molecular weight)
The number average molecular weight was calculated from the hydroxyl value.
(Acid value)
The acid value was determined from the mg number of KOH required to neutralize free carboxyl groups contained in 1 g of the solid content of the aqueous polyurethane resin composition in accordance with JIS K0070-1992.
(Synthesis of polyester glycol A)
A flask equipped with a dehydrator is charged with terephthalic acid (210 parts by weight) and adipic acid (93 parts by weight) as acid components, and ethylene glycol (62 parts by weight) and neopentyl glycol (104 parts by weight) as glycol components. Then, tetraisopropyl titanate (0.1 part by weight) was added as a reaction catalyst, and then a condensation reaction was performed at 220 ° C. until the acid value became 1.0 or less and the water content became 0.05% or less.

The obtained polyester glycol A had a number average molecular weight of 2000, a hydroxyl value of 56 mgKOH / g, and an acid component of 69% by weight.
(Synthesis of polyester glycol B)
Polyester glycol B was synthesized using the same method as described above (Synthesis of polyester glycol A) except that the reagent and the amount thereof were changed to those shown in Table 1.

The number average molecular weight of the obtained polyester polyol B was 2000, the hydroxyl value was 56 mgKOH / g, and the acid component was 54% by weight.
(Synthesis of polyester glycol C)
Polyester glycol C was synthesized using the same method as described above (Synthesis of polyester glycol A) except that the reagents and their amounts were changed to those shown in Table 1.

  The number average molecular weight of the obtained polyester polyol was 2000, the hydroxyl value was 56 mgKOH / g, and the acid component was 27% by weight.

Table 1 shows the reagents and reagent amounts used for the synthesis of polyester glycol C from polyester glycol A.

  In addition, the unit of the reagent amount used for reaction is a weight part.

(Synthesis Example 1)
Polyester glycol A (512.5 parts by weight) trimethylolpropane (13.3 parts by weight), dimethylolpropionic acid (24.7 parts by weight) were added to a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen blowing tube. Part), cyclohexanedimethanol (73.9 parts by weight), dicyclohexylmethane diisocyanate (375.6 parts by weight), methyl ethyl ketone (800 parts by weight), and reacted at 75 ° C. for 4 hours to contain free isocyanate groups relative to the non-volatile content. A methyl ethyl ketone solution of urethane prepolymer having an amount of 2.9% was obtained. The solution was cooled to 40 ° C., and the nonionic active agent Neugen EA-157 (Daiichi Kogyo Seiyaku Co., Ltd.) (15 parts by weight), Tinuvin 900 (Ciba Specialty Chemicals Co., Ltd.) (30 wt. Part), Tinuvin 123 (manufactured by Ciba Specialty Chemicals Co., Ltd.) (20 parts by weight) dissolved in methyl ethyl ketone (300 parts by weight), and 10% sodium hydroxide aqueous solution (23.6 parts by weight) being added After the addition, water (2200 parts by weight) was gradually added and emulsified and dispersed using a homogenizer. Dipropylene triamine (24.7 parts by weight) was added thereto and stirred for 1 hour. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane water dispersion 1 having a nonvolatile content of about 35%.

(Synthesis Example 2)
In the same manner as in Synthesis Example 1, polyester glycol B (512.5 parts by weight), trimethylolpropane (13.3 parts by weight), dimethylolpropionic acid (24.7 parts by weight), 1,4-cyclohexanedimethanol (73.9 parts by weight), 4,4′-dicyclohexylmethane diisocyanate (375.6 parts by weight) and methyl ethyl ketone (800 parts by weight) were added and reacted at 75 ° C. for 4 hours. A methyl ethyl ketone solution of urethane prepolymer of 2.9% was obtained. This solution was cooled to 40 ° C., and the nonionic active agent Neugen EA-157 (15 parts by weight) (Daiichi Kogyo Seiyaku Co., Ltd.), Tinuvin 384-2 (Ciba Specialty Chemicals: UV absorber) (50.0 parts by weight) dissolved in methyl ethyl ketone (300 parts by weight) was added, triethylamine (18.6 parts by weight), neutralized after addition, water (2200 parts by weight) was gradually added, and a homogenizer was used. Emulsified and dispersed. Dipropylene triamine (24.7 parts by weight) was added thereto and stirred for 1 hour. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane resin aqueous dispersion 2 having a nonvolatile content of about 35%.

(Synthesis Example 3)
In the same manner as in Synthesis Example 1, polyester glycol B (558.3 parts by weight), trimethylolpropane (14.5 parts by weight), dimethylolpropionic acid (26.9 parts by weight), 1,4-cyclohexanedimethanol (80.5 parts by weight), isophorone diisocyanate (146.7 parts by weight), 4,4′-dicyclohexylmethane diisocyanate (173.1 parts by weight) and methyl ethyl ketone (800 parts by weight) were added and reacted at 75 ° C. for 4 hours. A methyl ethyl ketone solution of a urethane prepolymer having a free isocyanate group content of 1.1% based on the nonvolatile content was obtained. This solution was cooled to 40 ° C., and JF-83 (manufactured by Johoku Chemical Co., Ltd .: UV absorber) (30.0 parts by weight) dissolved in methyl ethyl ketone (300 parts by weight) was added and triethylamine (20.2 parts by weight) was added. ) After neutralization, water (2200 parts by weight) was gradually added and emulsified and dispersed using a homogenizer. Dipropylenetriamine (9.1 parts by weight) was added to this and stirred for 1 hour. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane resin aqueous dispersion 3 having a nonvolatile content of about 35%.

(Synthesis Example 4)
In the same manner as in Synthesis Example 1, Kuraray polyol P-2020 (terephthalic acid / 3-methyl-1,5-pentanediol: number average molecular weight 2000: manufactured by Kuraray) (512.2 parts by weight), trimethylolpropane (13 .3 parts by weight), dimethylolpropionic acid (14.3 parts by weight), 1,4-cyclohexanedimethanol (84.9 parts by weight), 4,4′-dicyclohexylmethane diisocyanate (375.3 parts by weight), methyl ethyl ketone (800 parts by weight) was added and reacted at 75 ° C. for 4 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer having a free isocyanate group content of 2.9% with respect to the nonvolatile content. This solution was cooled to 40 ° C., Tinuvin 900 (manufactured by Ciba Specialty Chemicals: UV absorber) (30.0 parts by weight) dissolved in methyl ethyl ketone (300 parts by weight) was added, and a 10% sodium hydroxide aqueous solution ( 42.6 parts by weight) After neutralization, water (2200 parts by weight) was gradually added and emulsified and dispersed using a homogenizer. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane resin aqueous dispersion 4 having a nonvolatile content of about 35%.

(Synthesis Example 5)
In the same manner as in Synthesis Example 1, polyester glycol A (447.8 parts by weight), trimethylolpropane (11.6 parts by weight), dimethylolpropionic acid (21.6 parts by weight), 1,4-cyclohexanedimethanol (64.6 parts by weight), 4,4′-dicyclohexylmethane diisocyanate (454.4 parts by weight) and methyl ethyl ketone (800 parts by weight) were added and reacted at 75 ° C. for 4 hours, and the content of free isocyanate groups relative to the non-volatile content A methyl ethyl ketone solution of 6.5% urethane prepolymer was obtained. This solution was cooled to 40 ° C., Tinuvin 384-2 (manufactured by Ciba Specialty Chemicals: UV absorber) (70.0 parts by weight) dissolved in methyl ethyl ketone (400 parts by weight) was added, and 10% sodium hydroxide was added. After neutralization by adding an aqueous solution (64.4 parts by weight), water (2200 parts by weight) was gradually added and emulsified and dispersed using a homogenizer. Dipropylene triamine (54.0 parts by weight) was added thereto and stirred for 1 hour. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane resin aqueous dispersion 5 having a nonvolatile content of about 35%.

(Synthesis Example 6)
In the same manner as in Synthesis Example 1, polyester glycol A (524.2 parts by weight), trimethylolpropane (13.6 parts by weight), dimethylolpropionic acid (33.7 parts by weight), 1,4-cyclohexanediol ( 51.1 parts by weight), 4,4′-dicyclohexylmethane diisocyanate (377.4 parts by weight) and methyl ethyl ketone (800 parts by weight) were added and reacted at 75 ° C. for 4 hours. A methyl ethyl ketone solution of urethane prepolymer of 0.0% was obtained. The solution was cooled to 40 ° C., and the nonionic active agent Neugen EA-157 (Daiichi Kogyo Seiyaku Co., Ltd.) (10.0 parts by weight), Tinuvin 900 (Ciba Specialty Chemicals: UV absorber) (30.0 parts by weight) was dissolved in methyl ethyl ketone (300 parts by weight), added and neutralized by adding 10% aqueous sodium hydroxide solution (100 parts by weight). Then, water (2200 parts by weight) was gradually added, and the homogenizer was added. Used and emulsified and dispersed. To this was added isophoronediamine (54.6 parts by weight), and the mixture was stirred for 1 hour. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane resin aqueous dispersion 6 having a nonvolatile content of about 35%.

(Synthesis Example 7)
In the same manner as in Synthesis Example 1, Kuraray polyol P-2020 (476.8 parts by weight), trimethylolpropane (12.4 parts by weight), dimethylolpropionic acid (23.3 parts by weight), Newpol BPE-20NK (Manufactured by Sanyo Chemical Industries: Bisphenol A ethylene oxide 2 mol adduct: number average molecular weight 327.67) (147 parts by weight), 4,4'-dicyclohexylmethane diisocyanate (340.5 parts by weight), methyl ethyl ketone (800 parts by weight) In addition, the mixture was reacted at 75 ° C. for 4 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer having a free isocyanate group content of 2.7% based on the nonvolatile content. This solution was cooled to 40 ° C., and the nonionic active agent Neugen EA-157 (Daiichi Kogyo Seiyaku Co., Ltd.) (15.0 parts by weight), Tinuvin 900 (Ciba Specialty Chemicals: UV absorber) (30.0 parts by weight) dissolved in methyl ethyl ketone (300 parts by weight) was added, neutralized by adding 10% aqueous sodium hydroxide (69.4 parts by weight), and then water (2200 parts by weight) was gradually added. The mixture was emulsified and dispersed using a homogenizer. Diethylenetriamine (19.9 parts by weight) was added thereto and stirred for 1 hour. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane resin aqueous dispersion 7 having a nonvolatile content of about 35%.

(Synthesis Example 8)
In the same manner as in Synthesis Example 1, Kuraray polyol P-2020 (478.6 parts by weight), trimethylolpropane (12.4 parts by weight), dimethylolpropionic acid (25.2 parts by weight), ADEKA polyether BPX- 11 (manufactured by Asahi Denka Kogyo Co., Ltd .: bisphenol A propylene oxide 2-mole adduct: number average molecular weight 359.615) (149.4 parts by weight), 4,4′-dicyclohexylmethane diisocyanate (334.4 parts by weight), methyl ethyl ketone (800 Parts by weight) and reacted at 75 ° C. for 4 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer having a free isocyanate group content of 2.6% based on the nonvolatile content. This solution was cooled to 40 ° C., and the nonionic active agent Neugen EA-157 (Daiichi Kogyo Seiyaku Co., Ltd.) (15.0 parts by weight), Tinuvin 900 (Ciba Specialty Chemicals: UV absorber) (30.0 parts by weight) was dissolved in methyl ethyl ketone (300 parts by weight), added, neutralized by adding triethylamine (19.0 parts by weight), and then water (2200 parts by weight) was gradually added to emulsify using a homogenizer. Dispersed. Diethylenetriamine (19.1 parts by weight) was added to this and stirred for 1 hour. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane resin aqueous dispersion 8 having a nonvolatile content of about 35%.

(Synthesis Example 9)
In the same manner as in Synthesis Example 1, polyester glycol A (580 parts by weight), trimethylolpropane (15.0 parts by weight), dimethylolpropionic acid (105 parts by weight), isophorone diisocyanate (300 parts by weight), methyl ethyl ketone (800 Parts by weight) and reacted at 75 ° C. for 4 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer having a free isocyanate group content of 1.1% based on the nonvolatile content. The solution was cooled to 40 ° C., triethylamine (47.4 parts by weight) was added, neutralized, water (2200 parts by weight) was gradually added, emulsified and dispersed using a homogenizer, and stirred for 1 hour. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane resin aqueous dispersion 9 having a nonvolatile content of about 35%.

(Synthesis Example 10)
In the same manner as in Synthesis Example 1, polyester glycol A (582.9 parts by weight), trimethylolpropane (14.6 parts by weight), dimethylolpropionic acid (73.2 parts by weight), 3-methyl-1,5 -Pentanediol (27.9 parts by weight), isophorone diisocyanate (301.4 parts by weight), methyl ethyl ketone (800 parts by weight) were added and reacted at 75 ° C. for 4 hours. % Of a methyl ethyl ketone solution of urethane prepolymer. This solution was cooled to 40 ° C., Tinuvin 384-2 (manufactured by Ciba Specialty Chemicals: UV absorber) (50.0 parts by weight) dissolved in methyl ethyl ketone (400 parts by weight) was added, and 10% sodium hydroxide was added. After neutralization by adding an aqueous solution (64.4 parts by weight), water (2200 parts by weight) was gradually added and emulsified and dispersed using a homogenizer. Dipropylenetriamine (9.1 parts by weight) was added to this and stirred for 1 hour. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane resin aqueous dispersion 10 having a nonvolatile content of about 35%.

(Synthesis Example 11)
In the same manner as in Synthesis Example 1, polyester glycol C (512.5 parts by weight), trimethylolpropane (13.3 parts by weight), dimethylolpropionic acid (24.7 parts by weight), 1,4-cyclohexanedimethanol (73.9 parts by weight), 4,4′-dicyclohexylmethane diisocyanate (375.6 parts by weight) and methyl ethyl ketone (800 parts by weight) were added and reacted at 75 ° C. for 4 hours. A methyl ethyl ketone solution of 1.1% urethane prepolymer was obtained. The solution was cooled to 40 ° C., triethylamine (18.6 parts by weight) was added and neutralized, water (2200 parts by weight) was gradually added, and the mixture was emulsified and dispersed using a homogenizer. Dipropylenetriamine (9.1 parts by weight) was added to this and stirred for 1 hour. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane resin aqueous dispersion 11 having a nonvolatile content of about 35%.

(Synthesis Example 12)
In the same manner as in Synthesis Example 1, Nipponran 4010 (manufactured by Nippon Polyurethane Industry: Butylene Adipate, number average molecular weight 2,000, aromatic acid 0%) (512.5 parts by weight), trimethylolpropane (13.3 parts by weight) ), Dimethylolpropionic acid (24.7 parts by weight), 1,4-cyclohexanedimethanol (73.9 parts by weight), 4,4′-dicyclohexylmethane diisocyanate (375.6 parts by weight), methyl ethyl ketone (800 parts by weight) ) And reacted at 75 ° C. for 4 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer having a free isocyanate group content of 1.2% based on the nonvolatile content. The solution was cooled to 40 ° C., triethylamine (18.6 parts by weight) was added and neutralized, water (2200 parts by weight) was gradually added, and the mixture was emulsified and dispersed using a homogenizer. Dipropylene triamine (11.0 parts by weight) was added to this and stirred for 1 hour. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane resin aqueous dispersion 12 having a nonvolatile content of about 35%.

(Synthesis Example 13)
In the same manner as in Synthesis Example 1, polyester glycol A (523.1 parts by weight), trimethylolpropane (13.6 parts by weight), dimethylolpropionic acid (39.8 parts by weight), 1,4-cyclohexanediol ( 45.9 parts by weight), 4,4′-dicyclohexylmethane diisocyanate (377.6 parts by weight) and methyl ethyl ketone (800 parts by weight) were added and reacted at 75 ° C. for 4 hours. A methyl ethyl ketone solution of 0.5% urethane prepolymer was obtained. This solution was cooled to 40 ° C., and the nonionic active agent Neugen EA-157 (Daiichi Kogyo Seiyaku Co., Ltd.) (15.0 parts by weight), Tinuvin 900 (Ciba Specialty Chemicals: UV absorber) (30.0 parts by weight) was dissolved in methyl ethyl ketone (300 parts by weight), added, neutralized by adding triethylamine (30.0 parts by weight), and then water (2200 parts by weight) was gradually added and emulsified using a homogenizer. Dispersed. Dipropylene triamine (27.1 parts by weight) was added to this and stirred for 1 hour. The solvent was removed under reduced pressure at 50 ° C. to obtain a polyurethane resin aqueous dispersion 13 having a nonvolatile content of about 35%.

  The amounts of reagents used in Synthesis Examples 1 to 13 are shown in Table 2.

Example 1
1286 parts by weight of the polyurethane resin aqueous dispersion obtained in Synthesis Example 1 (corresponding to 100 parts by weight of solid (containing 186 parts by weight of water)) and polyisocyanate aqueous dispersion (using Aquanate 200: 28.6 parts by weight of solids) And a coating solution (total amount of water: 214.6 parts by weight) was prepared.

  A bar coater was applied to a corona discharge-treated surface of a 100 μm-thick stretched polypropylene film (OPP) subjected to a corona discharge treatment, and dried with a dryer at 50 ° C. for 30 seconds. A coating film having a dry film thickness of 3 μm was formed, and this was used as a test piece to conduct an OPP adhesion test, a stain resistance test, a blocking test, and a weather resistance test. The results are shown in Table 3.

(Example 2) to (Comparative Example 7)
Test pieces were prepared and various tests were conducted in the same manner as in Example 1. Table 3 shows the amounts of polyurethane resin water dispersion, polyisocyanate water dispersion, water used, and test results.

  The polyurethane resin aqueous dispersion used in Examples 1 to 7 contains about 35% non-volatile content and about 65% moisture. Therefore, the polyurethane resin aqueous dispersion corresponding to 100 parts by weight of the solid content contains about 186 parts by weight of water.

(Test method and evaluation method)
(1) OPP adhesion test: A test piece on which a coating film was formed was cured at 25 ° C. for 3 days, and the surface of the test piece was cut into a 1 mm width with a cutter knife to form 100 squares. An adhesive tape (manufactured by Nichiban, trade name: Cellotape (registered trademark)) was applied to the test piece, and this was rapidly peeled off.

Rating:
A: The coating film was not peeled at all. B: The coating film remained 80 to 99%. Δ: The coating film remained 50 to 79%. X: The coating film remained less than 50%. (2) Stain resistance. Test: The surface of the test piece was painted with a blue ink (aqueous) and a black pen (oil) to a diameter of 2 cm, left for 4 hours, wiped with ethanol, and the surface was observed.

Rating:
○: Dirt was not recognized Δ: Dirt was slightly left x: Dirt was remarkably left (3) Blocking property test: 2.0 kg / The sample was left in an oven at 50 ° C. while being compressed with cm ² . After 24 hours, it was taken out, the coated surface and the coated surface were peeled off, and the blocking state was observed.

Rating:
◯: Easily peeled Δ: Resistant but peeled ×: Not peeled (4) Weather resistance test: The test piece was exposed for 192 hours using an eye super UV tester (manufactured by Iwasaki Electric), and the appearance was visually observed Evaluated. The exposure conditions are: temperature 63 ° C., humidity 50% RH, irradiation intensity 60 mw / m ² . Exposure was performed for 8 cycles, with 20 hours of irradiation and 4 hours of condensation as one cycle.

Rating:
◎: No change was observed. ○: Minor gloss change was observed in a range that did not affect the product characteristics. △: Minor whitening was observed affecting the product characteristics. X: Significant whitening was observed. Was

  In Example 1- Example 8, it became clear that it was excellent in the adhesiveness with respect to an expanded polypropylene film (OPP), blocking property, and stain resistance.

Example 9
The test piece of Example 1 was subjected to a contamination test and a solvent rubbing test.
≪Contamination test≫
A few drops of the contaminants shown in Table 4 were dropped on the surface of the test piece of Example 1 via cotton and allowed to stand for 24 hours, followed by water → detergent (trade name “Mama Lemon”) → ethanol (99.5% ethanol). The condition of the wiped surface was evaluated according to the following criteria. In addition, the thing in which all of contaminants did not fall with water was wiped off using detergent, and the thing in which all of contaminants did not fall even with detergent was evaluated after wiping off using ethanol. The results are also shown in Table 4.

5: All contaminants fall 4: Some trace remains 3: Trace remains 2: Contaminant can be removed 1: Pollutant cannot be removed at all << Solvent rubbing test >>
Using the solvents shown in Table 4, the surface of the test piece was reciprocated 50 times with a load of 1500 g (the solvent was added after 25 times), and the surface condition was evaluated. The results are also shown in Table 4.

(Comparative Example 8)
In Example 1, the contamination test and the solvent rubbing test were performed on a test piece prepared by replacing the coating solution with a coating solution containing an acrylic resin aqueous dispersion as a binder component.

(Comparative Example 9)
In Example 1, the contamination test and the solvent rubbing test were carried out on a test piece prepared by replacing the coating solution with a coating solution containing an acrylic-urethane resin aqueous dispersion as a binder component.

(Examples 10 to 13)
Polyethylene wax (PE wax) was further added to the coating solution of Example 1. A coating film (test piece) was prepared in the same manner as in Example 1 using the coating solution after the addition. Next, the weather resistance and scratch resistance of the coating film were evaluated.

In Example 10, the following PE wax was used, and the amount added was 6 parts by weight of wax solids with respect to 100 parts by weight of resin solids in the coating solution.
・ PE wax (trade name “AB-50”, manufactured by Gifu Shellac Co., Ltd.)
-PE particle content: 40% by weight
・ PE particle shape: irregular shape ・ Average particle size of PE particles: 1 μm
-Molecular weight of PE particles: 4000
-Melting point of PE wax: 125 ° C
In Example 11, the following PE wax was used, and the addition amount was 6 parts by weight of wax solids with respect to 100 parts by weight of resin solids in the coating solution.
・ PE wax (trade name “Chemical Pearl W-300”, manufactured by Mitsui Chemicals, Inc.)
-PE particle content: 40% by weight
・ PE particle shape: spherical ・ Average particle diameter of PE particles: 3 μm
-Molecular weight of PE particles: 5500
-Melting point of PE wax: 132 ° C
In Example 12, the following PE wax was used, and the amount added was 6 parts by weight of wax solids with respect to 100 parts by weight of resin solids in the coating solution.
・ PE wax (trade name “Chemical Pearl W-100”, manufactured by Mitsui Chemicals, Inc.)
-PE particle content: 40% by weight
・ PE particle shape: spherical ・ Average particle diameter of PE particles: 3 μm
-Molecular weight of PE particles: 3600
-Melting point of PE wax: 128 ° C
In Example 13, the following PE wax was used, and the addition amount was 6 parts by weight of wax solids with respect to 100 parts by weight of resin solids in the coating solution.
・ PE wax (trade name “A-348”, manufactured by Gifu Shellac Co., Ltd.)
-PE particle content: 40% by weight
・ PE particle shape: irregular shape ・ Average particle size of PE particles: 3 μm
-Molecular weight of PE particles: 2500
-Melting point of PE wax: 115 ° C
The weather resistance test was conducted by the above method. The scratch resistance test was performed in accordance with a pencil hardness test (JISK 5400). These results are shown in Table 5 below.

  As apparent from Table 5, the addition of the PE wax improved the weather resistance and scratch resistance of the test piece. On the other hand, when PE particles having a molecular weight of less than 2500 or more than 8000 were used, no particular improvement in weather resistance was observed.

Claims (9)

A decorative sheet having a transparent surface protective layer formed from an aqueous polyurethane resin composition,
In the aqueous polyurethane resin composition, the polyurethane resin aqueous dispersion and the polyisocyanate aqueous dispersion have a solid content of 10 to 80 parts by weight based on 100 parts by weight of the solid content of the polyurethane resin aqueous dispersion. It is blended so that
The polyurethane resin aqueous dispersion emulsifies a urethane prepolymer obtained by reacting a polyester polyol (A), a chain extender (B), a compound (C), and an organic polyisocyanate (D) to form a polyamine (E). Cross-linked by
The polyester polyol (A) has a number average molecular weight of 500 to 5,000, is composed of an acid component and a glycol component, and contains 35% by weight or more of an aromatic dicarboxylic acid and / or an alicyclic dicarboxylic acid as the acid component. And
The chain extender (B) is a polyol having an aromatic ring and / or an alicyclic polyol having a number average molecular weight of less than 500,
The compound (C) has an anionic hydrophilic group and at least two active hydrogens in the molecule,
The polyamine (E) has two or more amino groups in the molecule.
A decorative sheet characterized by that.   The compound (C) has a carboxyl group and at least two active hydrogens in the molecule, and the acid value as the carboxyl group content of the aqueous polyurethane resin composition is 3 to 15 mgKOH / g. The decorative sheet as described.   The decorative sheet according to claim 1 or 2, wherein the organic polyisocyanate (D) is an alicyclic diisocyanate, and the urethane prepolymer contains 30 to 50% by weight of the alicyclic diisocyanate.   The decorative sheet according to claims 1 to 3, wherein the aqueous polyurethane resin composition further contains an ultraviolet absorber, and the content thereof is 1 to 10% by weight in the solid content of the aqueous polyurethane resin composition.   The decorative sheet according to any one of claims 1 to 4, wherein the ultraviolet absorber is added before emulsifying the urethane prepolymer.   The decorative sheet according to claim 4, wherein the aqueous polyurethane resin composition further contains a hindered amine light stabilizer.   The decorative sheet according to any one of claims 1 to 6, wherein the aqueous polyurethane resin composition further contains polyethylene particles having a molecular weight of 2500 to 8000.   The decorative sheet according to any one of claims 1 to 7, wherein the decorative sheet has a configuration in which a base sheet, a decorative layer, an adhesive layer, a transparent resin layer, and a transparent surface protective layer are sequentially laminated.   The decorative sheet according to claim 8, wherein the base sheet and the transparent resin layer contain a polyolefin resin as a resin component.