JP4927466B2 - Decorative sheet, aqueous resin composition for colored layer of decorative sheet, and aqueous coating solution for colored layer of decorative sheet - Google Patents

Description

  The present invention belongs to the technical field of a decorative sheet, an aqueous resin for a colored layer and an aqueous coating solution for a colored layer used in the decorative sheet.

  As a decorative sheet used for the interior of a building, the surface decoration of a fitting, the interior of a vehicle, etc., a base layer, a colored layer composed of a solid colored layer and / or a pattern colored layer, an adhesive layer, and a transparent resin layer are sequentially laminated. Cosmetic sheets are generally known.

  In such a conventional decorative sheet, for example, as described in Patent Document 1, a colored layer (also referred to as an ink layer) and an adhesive layer are made of an aromatic solvent such as toluene or xylene, or a fat such as methyl ethyl ketone or ethyl acetate. It is formed of a solvent-based coating liquid containing a group solvent.

  By the way, such aromatic solvents such as toluene and xylene and aliphatic solvents such as methyl ethyl ketone and ethyl acetate are organic volatile substances (hereinafter referred to as VOC), and their use has been demanded to be reduced in recent years. In particular, aromatic solvents such as toluene and xylene are listed as PRTR-designated chemical substances and substances for formulating guideline values for indoor air chemical substances. “Do not use aromatic solvents, use other solvents. There is a strong demand to “decrease.”

  In particular, in the production of decorative sheets, inconvenience in the working environment due to volatilization of VOC contained in the solvent-based coating liquid, and environmental safety due to the supply of VOC remaining in the decorative sheet to the general living space. There are sexual inconveniences. In response to these disadvantages, various means have been proposed to reduce the use of VOCs. For example, Patent Document 2 discloses a decorative sheet in which a colored layer or an adhesive layer is formed with an aqueous coating liquid in which the VOC content is reduced as much as possible.

The conventional decorative sheet formed by forming a colored layer or an adhesive layer with such an aqueous coating solution can further reduce the amount of volatilization and residual amount of VOC, and is effective in solving the environmental disadvantages described above. It is.
JP-A-11-198309 JP 2001-62970 A

  However, many of these conventional decorative sheets are inferior in interlayer adhesion between the base sheet constituting the decorative sheet and the transparent resin layer, and do not necessarily have sufficient interlayer adhesion, particularly interlayer adhesion after a weather resistance test. I couldn't say I was doing it.

  The present invention has been made to solve the above-mentioned inconveniences, and an object of the present invention is to reduce the residual amount of VOC as much as possible to further improve the environmental safety and to provide a decorative sheet excellent in interlayer adhesion and such The present invention provides an aqueous resin and an aqueous coating solution that can be suitably used for a colored layer of a decorative sheet.

The decorative sheet of the present invention that solves the above problems is a decorative sheet in which at least a base material, a colored layer, an adhesive layer, and a transparent resin layer are laminated in this order, and the colored layer contains an acrylic composite urethane emulsion The acrylic composite urethane emulsion has at least (A) isophorone diisocyanate, (B) 3-methyl-1,5-pentanediol and 1,6-hexanediol as constituent components. Polycarbonate polyol having a molar ratio of 3-methyl-1,5-pentanediol to 1,6-hexanediol in the range of 95: 5 to 75:25, and (C) two or more hydroxyl groups in the molecule and 1 It is composed of a urethane resin composed of a compound represented by the general formula (1) having at least one carboxyl group and ethyl methacrylate. Is composed of a acrylic resin, urethane resin weight ratio of acrylic resin 40: 60 to 60: characterized in that in the range of 40.

  The estimated glass transition temperature of the acrylic resin is 40 to 80 ° C., and this acrylic composite urethane emulsion has a structure in which the urethane resin composition is located around the acrylic resin composition, and the weight average molecular weight of the urethane resin composition Is preferably 40,000 to 100,000.

  According to this invention, since the aqueous coating liquid is used to form the colored layer, the occurrence of VOC caused by the conventional solvent-based coating liquid is suppressed, and the volatilization amount of VOC and the makeup in the working environment are suppressed. The remaining amount of VOC in the sheet can be reduced, and as a result, the environmental safety of the decorative sheet can be further improved. In addition, since the water-based coating liquid contains an acrylic composite urethane emulsion, the acrylic composite urethane emulsion has initial adhesion to the base sheet, which is a characteristic of urethane resin, and high weather resistance, which is a characteristic of acrylic resin. Therefore, the manufactured decorative sheet has excellent interlayer adhesion after the weather resistance test.

  In addition, as a specific structure of the decorative sheet of the present invention described above, the base material is formed of a material mainly composed of a polyolefin-based elastomer, or the transparent resin layer is formed of a material mainly composed of a polyolefin-based resin. , Forming a concavo-convex pattern on the surface side of the transparent resin layer, forming a partially colored layer on the concave portion of the concavo-convex pattern, providing a protective layer on the surface of the transparent resin layer, or providing a primer layer on the back surface of the substrate Can be provided.

An aqueous resin for a colored layer of a decorative sheet of the present invention that solves the above problems is an acrylic composite urethane emulsion, and comprises at least (A) isophorone diisocyanate and (B) 3-methyl-1,5-pentanediol as constituent components. A polycarbonate polyol having a molar ratio of 3-methyl-1,5-pentanediol to 1,6-hexanediol in the range of 95: 5 to 75:25, and (C) two or more in the molecule A urethane resin composed of a compound represented by the general formula (1) having a hydroxyl group and one or more carboxyl groups, and an acrylic resin having ethyl methacrylate as a constituent component, and urethane on the surface of the acrylic resin composition The resin composition is located, and the weight ratio of urethane resin: acrylic resin is 40: 60-60: 40 A circumference, characterized in that the estimated glass transition temperature of 40 to 80 ° C. acrylic composition, the weight average molecular weight of the urethane resin is 40,000-100,000.

  Moreover, the aqueous coating liquid for a colored layer of a decorative sheet of the present invention that solves the above-described problems is characterized by containing the aqueous resin for a colored layer of the decorative sheet. According to these inventions, it is possible to solve the inconvenience of the VOC caused by the solvent-based coating liquid, and to form a colored layer of a decorative sheet having high environmental safety and excellent interlayer adhesion after a weather resistance test. it can.

  According to the present invention, since the colored layer is formed by the aqueous coating liquid containing the acrylic composite type urethane emulsion, a decorative sheet having excellent adhesion between the base material and the colored layer and between the colored layer and the adhesive layer is provided. The Furthermore, according to the decorative sheet of the present invention, since the colored layer is formed by the aqueous coating liquid, the volatilization amount of VOC in the working environment of the decorative sheet and the remaining amount of VOC in the decorative sheet can be reduced as much as possible. it can. As a result, environmental safety can be further improved.

  Hereinafter, the decorative sheet of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an example of the layer structure of the decorative sheet 1 of the present invention. The decorative sheet 1 of the present invention shown in FIG. 1 has a base material 2, a solid colored layer 3, a pattern colored layer 4, an adhesive layer 5, a transparent resin layer 6, an uneven pattern 7, a partially colored layer 8, and a protective layer 9 laminated in order. It is a form made. A primer layer 10 is formed on the back surface of the substrate 2.

(Base material)
The base material 2 is an indispensable structure in the decorative sheet 1, and various olefin resins shown below can be preferably applied. The base material 2 is preferably made of a material mainly composed of a polyolefin-based elastomer. When the material contains a component other than the polyolefin-based elastomer, the polyolefin-based elastomer is contained in the largest proportion. . For example, (a) a mixture having high-density polyethylene or polypropylene as a hard segment and an elastomer or an inorganic filler as a soft segment, (b) JP-A-9-1111055, JP-A-5-77371, Ethylene-propylene-butene copolymer described in Kaihei 7-316358 and the like, (c) isotactic polypropylene as a hard segment and attack as a soft segment described in JP-B-6-23278 A mixture with tic polypropylene can be used.

  The high-density polyethylene as the hard segment (a) is preferably a polyethylene having a specific gravity of 0.94 to 0.96, which has a high degree of crystallinity obtained by the low-pressure method and has few branched structures in the molecule. High-density polyethylene, which is a polymer, is used. As the polypropylene as the hard segment, isotactic polypropylene is preferably used.

  Diene rubber, hydrogenated diene rubber, olefin elastomer, and the like are used as the elastomer (i) as the soft segment. The hydrogenated diene rubber is obtained by adding a hydrogen atom to at least a part of the double bond of the diene rubber molecule, and suppresses the crystallization of the polyolefin resin to improve its flexibility. . Examples of the diene rubber include isoprene rubber, butadiene rubber, butyl rubber, propylene / butadiene rubber, acrylonitrile / butadiene rubber, acrylonitrile / isoprene rubber, and styrene butadiene rubber. The olefin elastomer is an elastic copolymer to which at least one polyene copolymerizable with two or more olefins is added. Ethylene, propylene, α-olefin, etc. are used as the olefin, 1,4 hexadiene, cyclic diene, norbornene and the like are used. Preferred examples of the olefin elastomer include elastic copolymers containing olefin as a main component such as ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene rubber, and ethylene-butadiene copolymer rubber. Note that these elastomers may be overcrosslinked using a crosslinking agent such as an organic peroxide or sulfur as necessary.

  The amount of these elastomers added is 10 to 60% by weight, preferably about 30% by weight. If the amount of elastomer added is less than 10% by weight, the change in the constant load elongation becomes too steep, and the elongation at break, impact resistance, and easy adhesion are reduced. When the added amount of the elastomer is higher than 60% by weight, transparency, weather resistance and creep resistance are deteriorated.

  As the inorganic filler (a), powder having an average particle size of about 0.1 to 10 μm, such as calcium carbonate, barium sulfate, clay, and talc, is used. As addition amount, it is 1 to 60 weight%, Preferably it is 5 to 30 weight%. When the added amount of the inorganic filler is less than 1% by weight, the creep deformation resistance and the easy adhesion property are lowered. Moreover, when the addition amount of an inorganic filler exceeds 60 weight%, the elongation at break and impact resistance will fall.

  As the (olefin) olefin resin, a thermoplastic elastomer made of an ethylene / propylene / butene copolymer resin is used. Here, as butene, any of the three structural isomers of 1 butene, 2 butene, and isobutylene can be used. The copolymer is a random copolymer and includes a part of an amorphous part.

  Preferable specific examples of the ethylene / propylene / butene copolymer resin include the following (a) to (c).

  (A) A random copolymer made of a terpolymer of ethylene, propylene and butene described in JP-A-9-1111055. In this random copolymer, the weight ratio of the propylene component is preferably 90% by weight or more, and the melt flow rate is 1 to 50 g / 10 min under the conditions of 230 ° C. and 2.16 kg. preferable. Such a random copolymer comprises 0.01 to 50 parts by weight of a transparent nucleating agent mainly composed of a phosphoric acid aryl ester compound and a fatty acid amide having 12 to 22 carbon atoms with respect to 100 parts by weight of the random copolymer. 0.003 to 0.3 parts by weight is melt kneaded.

  (B) A terpolymer of ethylene, propylene and butene described in JP-A-5-77371. This copolymer is obtained by adding 80 to 0% by weight of crystalline polypropylene to 20 to 100% by weight of an amorphous polymer having a propylene component weight ratio of 50% by weight or more.

  (C) A terpolymer of ethylene, propylene and 1-butene described in JP-A-7-316358. In this copolymer, propylene and / or 1 butene content was mixed with 20 to 100% by weight of a low crystalline polymer having a content of 50% by weight or more and 80 to 0% by weight of a crystalline polyolefin such as isotactic polypropylene. An oil gelling agent such as N acylamino acid amine salt and N acylamino acid ester is added in an amount of 0.5% by weight to the composition.

  The ethylene / propylene / butene copolymer resins of the above (a) to (c) may be used alone, or may be further mixed with other polyolefin resins as necessary.

  As the olefin-based resin (c), as described in Japanese Patent Publication No. 6-23278, the (A) soft segment has a number average molecular weight Mn of 25000 or more, and a weight average molecular weight Mw and a number average molecular weight Mn. 10% to 90% by weight of atactic polypropylene soluble in boiling heptane with a ratio Mw / Mn ≦ 7, and (B) as a hard segment, an isotactic insoluble in boiling heptane having a melt index of 0.1 to 4 g / 10 min. Examples thereof include soft polypropylene composed of a mixture of 90 to 10% by weight of tic polypropylene.

  Among the olefinic thermoplastic elastomers of (c) above, those composed of a mixture of isotactic polypropylene and atactic polypropylene and having a weight ratio of atactic polypropylene of 5 to 50% by weight are preferably used. Those having a weight ratio of 20 to 40% by weight are particularly preferably used. When the weight ratio of the atactic polypropylene is less than 5% by weight, when embossing or forming into an article having a three-dimensional shape or a concavo-convex shape, deformation of the non-uniform sheet-like substrate due to necking may occur. As a result, wrinkles, pattern distortion, etc. occur. On the other hand, when the weight ratio of the atactic polypropylene exceeds 50% by weight, the sheet-like base material itself is easily deformed, and the base material is deformed when the base material is passed through a printing machine, and the pattern of the colored layer 11 is distorted. In addition, defects such as misregistration are likely to occur in the case of multicolor printing, and the sheet is easily torn during molding.

  A colorant, a heat stabilizer, a flame retardant, an ultraviolet absorber, a radical scavenger, and the like are added to the above-described olefin resin forming the substrate 2 as necessary.

  Coloring agents include titanium white, zinc white, bengara, vermilion, ultramarine blue, cobalt blue, titanium yellow, yellow lead, carbon black and other inorganic pigments, isoindolinone, Hansa Yellow A, quinacridone, permanent red 4R, phthalocyanine blue, etc. Organic pigments or dyes, metallic pigments made of foil powder such as aluminum and brass, pearlescent pigments made of foil powder such as titanium dioxide-coated mica and basic zinc carbonate, and the like are used. Moreover, you may add an inorganic filler in the ratio of 5 to 60 weight% as needed. Examples of the inorganic filler include powders of calcium carbonate, barium sulfate, clay, talc, silica (silicon dioxide), alumina (aluminum oxide), and the like. The colorant is added to give the base material 2 a color necessary for the decorative sheet 1, and may be either transparent coloring or opaque (concealing) coloring, but generally the concealment of the adherend 15. Opaque coloring is preferred.

  As the heat stabilizer, known ones such as phenol, sulfite, phenylalkane, phosphite, and amine can be used, and the prevention of deterioration such as thermal discoloration during heat processing can be improved. A flame retardant is added when imparting flame retardancy, and powders such as aluminum hydroxide and magnesium hydroxide are used. The ultraviolet absorber is for imparting better weather resistance (light resistance) to the resin, and is an organic substance such as benzotriazole, benzophenone, salicylic acid ester, or particulate zinc oxide having a diameter of 0.2 μm or less, Inorganic substances such as cerium oxide and titanium oxide are used. In addition, a reactive ultraviolet absorber in which an acryloyl group or a methacryloyl group is introduced into the benzotriazole skeleton is also used. In addition, the addition amount of these ultraviolet absorbers is about 0.5 to 10 weight% normally. The radical scavenger is for further preventing deterioration due to ultraviolet rays and improving weather resistance, and includes bis- (2,2,6,6-tetramethyl-4-biperidinyl) sebacate and bis- (N-methyl). -2,2,6,6-tetramethyl-4-biperidinyl) sebacate, and other hindered radical scavengers such as compounds disclosed in JP-B-4-82625, biperidinyl radical scavengers, etc. Is done.

  The base material 2 can be obtained by forming a film obtained by arbitrarily selecting and blending the above materials by a conventional method such as calendering. The thickness of the base material 2 is 10-200 micrometers, Preferably it is about 50-100 micrometers.

  The surface of the substrate 2 on the surface side (transparent resin layer 6 side) of the decorative sheet 1 is preferably subjected to easy adhesion treatment such as application of an easy adhesion layer, corona discharge treatment, plasma treatment, ozone treatment and the like. Examples of the resin constituting the easy adhesion layer (also referred to as a primer layer or an anchor layer) include acrylic resin, vinyl chloride-vinyl acetate copolymer, polyester resin, urethane resin, chlorinated polypropylene, and polyethylene chloride.

  In addition to the base material 2 composed of the above-described polyolefin resin, a woven or non-woven fabric using an organic resin such as polyester or vinylon, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer , Vinyl resins such as ethylene-vinyl alcohol copolymer, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, acrylic resins such as polymethyl methacrylate, polymethyl acrylate and polyethyl methacrylate, polystyrene, acrylonitrile butadiene A sheet or film made of a resin such as styrene copolymer (ABS), cellulose triacetate, cellophane, polycarbonate or the like can be used as the substrate 2. In addition, thin paper, kraft paper, titanium paper, linter paper, paperboard, gypsum board paper, fine paper, coated paper, art paper, sulfuric acid paper, glassine paper, parchment paper, paraffin paper, etc. A so-called vinyl wallpaper original fabric obtained by sol coating or dry laminating vinyl can also be used. Further, a sheet or film made of inorganic fibers such as glass fibers, asbestos, potassium titanate fibers, alumina fibers, silica fibers, and carbon fibers can be used as the substrate 2. Moreover, metal foils, such as aluminum, iron, stainless steel, copper, etc. can also be used. Further, a material obtained by laminating a plurality of such base material materials can be used as the base material 2.

(Colored layer)
The colored layer 11 is an essential layer in the decorative sheet 1 and is composed of the solid colored layer 3 and / or the pattern colored layer 4.

  As shown in FIG. 1, the solid colored layer 3 is provided for the purpose of concealing the background of the base material 2 and improving adhesion to the base material, and is usually formed as a solid solid colored layer without a pattern. . On the other hand, the pattern coloring layer 4 has a pattern or color composed of a wood grain pattern, a stone pattern, a cloth pattern, a leather pattern, a geometric figure, etc., depending on figures, characters, symbols, colors, combinations thereof, etc. On the colored layer 3, it is formed as a layer having a planar shape, an uneven shape, or a convex shape (see FIG. 1). Moreover, the pattern colored layer 4 shall also have functions, such as preventing blocking with the back surface side of the base material 2 and the colored layer 11, when what formed the colored layer 11 is temporarily preserve | saved in a roll state. . Note that the pattern coloring layer 4 may also function as the solid coloring layer 3, and in this case, the pattern coloring layer 4 becomes the solid coloring layer 3. The solid colored layer 3 and / or the pattern colored layer 4 thus formed may be provided on the entire surface of the substrate 2 or may be partially provided. Further, as shown in FIG. 1, the colored layer 11 is composed of a solid colored layer 3 provided on the entire surface of the substrate 2 and a pattern colored layer 4 partially provided on the surface of the solid colored layer 3. You can also

  The colored layer 11 is formed by an aqueous coating solution for a colored layer of the decorative sheet of the present invention containing an acrylic composite urethane emulsion. That is, using such an aqueous coating solution, the colored layer 11 composed of the solid colored layer 3 and / or the pattern colored layer 4 is formed by applying the solution onto the substrate 2 and drying it. The colored layer 11 thus formed can suppress the occurrence of VOC as in the prior art and can contribute to further improving the environmental safety of the decorative sheet. Furthermore, by forming the colored layer 11 with this water-based coating liquid, there are other effects that could not be initially imagined that the interlayer adhesion of the decorative sheet is improved and that the weather resistance adhesion and boiling water resistance are also good. It was. In the following, the aqueous coating liquid for forming the solid colored layer 3 is referred to as an aqueous coating liquid for the solid colored layer, and the aqueous coating liquid for forming the pattern colored layer 4 is the aqueous coating liquid for the pattern colored layer. These water-based coating liquids may be collectively referred to as a water-based coating liquid for a colored layer.

  The basic composition of the aqueous coating liquid for the solid colored layer contains an acrylic composite urethane emulsion that is an aqueous resin as a binder component, an aqueous dispersion isocyanate as a crosslinking agent, and a pigment as a coloring agent. Further, it contains water or a mixture of water and alcohol as a solvent. The basic composition of the aqueous coating liquid for the pattern colored layer includes an acrylic composite urethane emulsion which is an aqueous resin as a binder component, a pigment as a colorant, and water or water and alcohol as a solvent. Containing a mixture of In addition, you may make the water-system coating liquid for pattern colored layers contain water-dispersed isocyanate as a crosslinking agent.

(1) Acrylic composite type urethane emulsion The acrylic composite type urethane emulsion which is an aqueous resin is contained in the aqueous coating liquid for the colored layer as a binder component. The acrylic composite urethane emulsion is a resin in which a urethane resin composition and an acrylic resin composition are blended at a predetermined composition ratio. As shown in FIG. 6, the acrylic composite urethane emulsion 60 has a structure in which the urethane composition 61 is positioned around the acrylic composition 62, in other words, a urethane composition portion 61 (hereinafter also referred to as a urethane portion). A core-shell structure is formed with an acrylic composition portion 62 (hereinafter also referred to as an acrylic portion) on the outside. The core-shell structure specifically refers to a structure in which components having different resin compositions exist in the same micelle and the resin composition is different between the central portion (core) and the outer shell portion (shell). The core-shell structure can be analyzed by transmission electron microscope observation with ruthenium staining. By using such an aqueous resin for the aqueous coating liquid for the colored layer of the decorative sheet, there is an advantage that the affinity with water as the solvent is increased and the stability of the aqueous coating liquid is excellent.

  The constituent weight ratio between the urethane resin composition and the acrylic resin composition of the acrylic composite urethane emulsion is preferably urethane resin: acrylic resin = 60: 40 to 40:60, more preferably 50:50 to 60:50. is there. The constituent weight ratio can be measured by the area ratio by the GPC method. When the urethane resin composition ratio in the emulsion is 40 or less, the amount of hydrophilic groups introduced into the urethane resin composition increases, and the water resistance decreases. At the present stage, when the urethane resin composition ratio is 60 or more, the viscosity at the time of phase inversion becomes very high, and aggregates and the like are generated during phase inversion. Within this range, there is an effect of improving the interlayer adhesion of the decorative sheet by increasing the urethane component over the acrylic component that does not originally contribute to the interlayer adhesion.

  The weight average molecular weight of the urethane resin of the acrylic composite type urethane emulsion is about 40,000 to 100,000, and the smaller one is preferable within this range. By setting it as such molecular weight, the interlayer adhesiveness when the colored layer of a decorative sheet is formed can be improved. When the molecular weight of the urethane resin is 40,000 or less, the cohesive force of the urethane resin is lowered, so that the adhesive force is lowered, and when it is 100,000 or more, the cohesive force of the urethane resin becomes too high and the adhesiveness is lowered. It is considered at the time.

  Next, the urethane part will be described. The urethane part of the acrylic composite-type urethane emulsion has a predetermined composition and a predetermined weight average molecular weight described below, and is disposed outside the acrylic composite-type urethane emulsion to dispose the aqueous resin in the solvent of the aqueous coating liquid. It plays the role of an emulsifier to be dispersed. Moreover, when forming the colored layer 11 of the decorative sheet 1, it reacts with the cross-linking agent to improve the adhesion to the substrate 2 and to improve the interlayer adhesion. In addition, there is a role of improving the cohesive strength of the colored layer and improving the water resistance.

The urethane part of the acrylic composite urethane emulsion has (A) isophorone diisocyanate, (B) 3-methyl-1,5-pentanediol and 1,6-hexanediol as essential components, and 3-methyl-1, A polycarbonate polyol having a molar ratio of 5-pentanediol to 1,6-hexanediol of 95/5 to 75/25, and (C) a urethane resin containing as an essential component a compound of the following general formula (1) .

  Moreover, it has the structure which introduce | transduced the hydrophilic group only into the urethane part of an acrylic complex-type urethane emulsion, and it is preferable that this hydrophilic group introduce | transduces 1 functional group amount with respect to the urethane number molecular weight 1500-2000. If the urethane number molecular weight per hydrophilic group amount is too small, the hydrophilic group amount is too large, so that the hydrophilicity is too high to make emulsification difficult in production. If the number of molecular weights of urethane per hydrophilic group amount is too large, the amount of hydrophilic groups contained in the emulsion is too small, and an emulsion may not be generated or aggregates may be generated.

  By setting the amount of the hydrophilic group within such a range, there is an effect of improving the storage stability of the water-based ink using the acrylic composite type urethane emulsion, and the amount of the hydrophilic group is such that the stability as the ink is not lowered. There is an effect that it is possible to improve the interlayer adhesion of the decorative sheet formed by reducing. Examples of hydrophilic groups include neutralized tertiary amines of carboxyl groups.

  By setting the amount of the hydrophilic group within this range, compatibility between the aqueous resin and the hydrophobic base material 2 can be increased, and interlayer adhesion can be improved. That is, in the case where polypropylene is used as the base material 2 described above, the surface of the base material is corona-treated to introduce hydrophilic groups to enhance compatibility with the aqueous resin. It is considered that the introduced hydrophilic group is deactivated by moving from the surface of the polypropylene to the inside, and the surface of the base material returns to hydrophobic. Therefore, the hydrophobicity of the aqueous resin is improved by reducing the amount of hydrophilic groups in the aqueous resin, the compatibility between the aqueous resin and the substrate 2 is improved, and the interlayer adhesion of the decorative sheet is improved. Is considered. In addition, when using polyethylene as the base material 2, a hydrophilic group does not deactivate.

  The urethane part of the acrylic composite urethane emulsion may have a composition provided with a functional group such as a sulfonic acid-sodium salt in addition to the hydrophilic group described above. Such a functional group is provided to improve the re-solubility of the coating film when the water-based ink is dried due to its extremely high hydrophilicity.

  Moreover, the molecular weight of the urethane composition portion (urethane portion) is about 40,000 to 100,000. By setting it as such molecular weight, there exists an effect | action that the interlayer adhesiveness of the formed decorative sheet increases.

  Next, the acrylic part will be described. The acrylic part of the acrylic composite urethane emulsion has a predetermined composition described below and a predetermined estimated glass transition temperature (hereinafter, the estimated glass transition temperature is referred to as Tg). It is arrange | positioned and the interlayer adhesiveness after forming the colored layer of a decorative sheet is improved. In addition, there is a role to improve weather resistance.

  The acrylic part of the acrylic composite urethane emulsion is represented by an acrylic composition mainly composed of ethyl methacrylate (ethyl methacrylate). Such a composition has the effect of softening at the temperature at the time of drying to improve the film-thickness and to improve the weather resistance adhesion.

  Moreover, Tg of a (meth) acryl part is about 40-80 degreeC. By being in such a TG range, the acrylic composite emulsion becomes rubbery by heating at the time of printing, the wettability with the base material becomes good, and the glassy state is obtained at the time of cooling. There exists an effect that the adhesiveness with the base material of the colored layer formed in the sheet | seat can be improved.

  In the case where the Tg of the (meth) acrylic part is within such a range, it is preferable to further soften the (meth) acrylic part of the (meth) acrylic composite urethane emulsion. In order to soften the (meth) acrylic part, the Tg of acrylic may be shifted to a lower side. For example, the Tg is preferably about 40 to 60 ° C. By making it within such a range, the tackiness of the aqueous resin acrylic increases, the tackiness of the aqueous coating liquid increases, and the adhesion of the formed colored layer to the substrate increases, so the interlayer adhesion of the decorative sheet It is thought that the property improves. In addition, Tg of an acrylic part is the value which added Tg of each homopolymer of the monomer to be used with the content ratio.

  In the acrylic composite urethane emulsion described above, the average particle size is about 50 to 200 μm. Here, the average particle size means a particle size having a frequency of 50% when the particle size distribution is measured with a light interference type particle size measuring device. At the time of this application, it is difficult to produce an emulsion having a particle size of 50 μm or less with the (meth) acrylic composite urethane emulsion of the present application, and when it is 200 μm or more, the emulsion is unstable, and in some cases, aggregates are present. There is a possibility of generating.

  An emulsified weathering stabilizer may be added to the acrylic composite urethane emulsion. Although the weather resistance of the acrylic composite emulsion of the present application is sufficiently high, depending on the required performance, the addition of weather stabilizers such as UV absorbers and antioxidants can suppress the molecular cleavage and increase the weather resistance. There is.

  As described above, the acrylic composite urethane emulsion, which is an aqueous resin for a colored layer of a decorative sheet, is composed of a predetermined urethane composition and a predetermined acrylic composition, and urethane: acryl is blended in a predetermined composition ratio. Thus, a decorative sheet with improved interlayer adhesion can be provided. Among these acrylic composite urethane emulsions, those having the above-mentioned predetermined acrylic Tg and predetermined urethane molecular weight are preferably used for the aqueous coating liquid for the colored layer of the decorative sheet.

  A typical method for producing an acrylic composite urethane emulsion used in the aqueous coating liquid for a colored layer of a decorative sheet is shown below, but an acrylic composite urethane emulsion produced by a conventionally known method can also be used.

  First, a urethane prepolymer terminated with an isocyanate group is prepared by reacting (A) an organic polyisocyanate with (B) a polyol and (C) a compound containing an active hydrogen group and an ionic group in an acrylic monomer that is non-reactive with isocyanate groups. Generate. Usually, the ratio of NCO groups of the organic polyisocyanate and the active hydrogen groups in which the polyol and the ionic group-forming compound are combined is in the range of 1.1: 1 to 3.0: 1 in molar ratio, and the NCO groups are excessive. The prepolymerization reaction is usually performed at 50 to 100 ° C., but in the presence of air, a polymerization inhibitor such as p-methoxyphenol is about 20 to 3000 ppm with respect to the monomer in order to prevent heat polymerization of the acrylic monomer described later. It is preferable to add within a range. At this time, an organotin compound such as dibutyltin dilaurate, dibutyltin dioctoate, stannous octoate, or a tertiary amine compound such as triethylamine or triethylenediamine may be used as a catalyst for the urethanization reaction. In this way, an acrylic monomer solution of an isocyanate group-terminated urethane prepolymer is obtained.

  As the organic polyisocyanate used in the present invention, (A) isophorone diisocyanate (IPDI) is an essential component. In addition, 2,4-tolylene diisocyanate (2,4-TDI) and a mixture thereof with 2,6-tolylene diisocyanate (2,6-TDI), 4,4′-diphenylmethane diisocyanate, as long as there is no problem in performance. 1,4-phenylene diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate (HMDI), trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene It is also possible to mix range isocyanate and the like. Further, if necessary, a small amount of a polyfunctional isocyanate which is a reaction product with a trimer such as TDI, HMDI, or IPDI, or trimethylolpropane can be used.

  The polyol used in the present invention is a polycarbonate polyol containing (B) 3-methyl-1,5-pentanediol as an essential component, preferably further containing 1,6-hexanediol, and 3-methyl-1, A polycarbonate polyol in which 5-pentanediol and 1,6-hexanediol are in a molar ratio of 95: 5 to 75:25 is preferable. In addition, polyether polyols, polyester polyols, polycarbonate polyols, polybutadiene polyols, hydrogenated polybutadiene polyols, acrylic polyols, epoxy polyols, and the like can be mixed as long as there is no problem in performance.

  The number average molecular weight of the polyol is usually 1000 to 3000, more preferably 1500 to 2500. If this molecular weight is too small, the function as a polyol will not be exhibited, and if it is too large, the viscosity of the resulting urethane prepolymer will increase, causing the formation of aggregates and poor dispersion during water dispersion, and the amount of hydrophilic groups will decrease. Therefore, water dispersion tends to be poor.

  Moreover, as a compound containing the active hydrogen group and ionic group formation used in this invention, (C) It represents with General formula (1) which has a 2 or more hydroxyl group and a 1 or more carboxyl group in a molecule | numerator. A compound is an essential component. The compound represented by the general formula (1) acts as an ion forming group in the urethane resin. Examples of those containing a carboxyl group include dimethylolpropionic acid.

  In addition to (C), dimethylolacetic acid, dimethylolbutanoic acid, dimethylolheptanoic acid, dimethylolnonanoic acid, 1-carboxy-1,5-pentylenediamine, dihydroxybenzoic acid, 3,5-diaminobenzoic acid Alkanol carboxylic acids such as polyoxypropylene triol and half ester compounds of maleic anhydride and phthalic anhydride, sulfonic acid alkali metal bases such as 2-sulfo-1,4-butanediol sodium salt, 5-sulfo-di -Β-hydroxyethyl isophthalate sodium salt, N, N-bis (2-hydroxyethyl) aminoethylsulfonic acid tetramethylammonium salt, N, N-bis (2-hydroxyethyl) aminoethylsulfonic acid tetraethylammonium salt, N , N-bis (2-hydroxyethyl It is also possible to use an aminoethyl sulfonic acid benzyl triethylammonium salts.

  When a compound containing a carboxyl group is used, an amine such as trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, triethylenediamine or dimethylaminoethanol is used as a neutralizing agent to form a carboxyl group salt to make it hydrophilic. Alkali metal compounds such as sodium hydroxide and potassium hydroxide are used. The neutralization rate with respect to the carboxyl group is usually 50 to 100 mol%. As a neutralizing agent, triethylamine is preferable from the viewpoint of improving basicity and water resistance.

  As the (meth) acrylic monomer that is non-reactive with the isocyanate group in the present invention, ethyl methacrylate is an essential component. In addition, an acrylic monomer that does not contain a hydroxyl group, a carboxyl group, a silanol group, an amino group, a glycidyl group, or the like can be used as long as there is no problem in performance. For example, (meth) acrylic acid alkyl ester as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid Pentyl, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl methacrylate, lauryl (meth) acrylate, methoxyethyl (meth) acrylate, methoxy (meth) acrylate Butyl, ethoxybutyl (meth) acrylate, polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, polyethylene glycol di (meth) acrylate, ethylene oxide (Meth) acrylate of id / tetrahydrofuran copolymer, (meth) acrylate of ethylene oxide / propylene oxide copolymer, polyethylene glycol monoallyl ether, acrylamide, N-butoxymethyl (meth) acrylamide, N-methyl Those having an amide group such as acrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide, diacetoneacrylamide, N-vinylformamide, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, N, N -Monomers having a tertiary amino group such as dimethylaminopropyl methacrylate, monomers containing nitrogen such as N-vinylpyrrolidone, N-vinylimidazole, N-vinylcarbazole Cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cycloaliphatic monomers such as isobornyl (meth) acrylate, aromatic monomers such as styrene, α-methylstyrene, phenyl methacrylate, vinyltriethoxysilane, γ- Examples thereof include silicon-containing monomers such as methacryloyloxypropyltrimethoxysilane, and fluorine-containing monomers such as octafluoropentyl (meth) acrylate and perfluorocyclohexyl (meth) acrylate. Other examples include divinylbenzene and trimethylolpropane triacrylate.

  When an acrylic monomer is added to the acrylic monomer solution of the urethane prepolymer, the addition time is not particularly limited, and it can be added at any time before or after the urethane prepolymer neutralization step described later. Further, after the neutralized urethane prepolymer is dispersed in water, an acrylic monomer may be added to the dispersion.

  In order to disperse the acrylic monomer solution of the urethane prepolymer in water, the ionic group forming compound is incorporated into the urethane prepolymer molecular chain, and the neutralizing agent necessary for ionic group formation is added as necessary. Gives the polymer a self-emulsifying property. The content of ionic groups is preferably in the range of 1500 to 2000 urethane number molecular weight per ionic group. If the urethane number molecular weight per ionic group is too small, the film properties and water resistance of the resulting resin tend to deteriorate. On the other hand, if it is too large, the self-emulsifying property of the urethane prepolymer will be insufficient, the average particle size of the dispersed particles will become large and the dispersion stability will deteriorate, and it will be difficult to form a dense film.

  Further, when the urethane prepolymer solution is dispersed in water, by adding a polyoxyalkylene group-containing acrylic monomer, the dispersion in water becomes good and a uniform and more stable dispersion can be obtained. The polyoxyalkylene group-containing acrylic monomer is an acrylic monomer whose terminal is a hydroxy group or an alkyleneoxy group having 1 to 3 carbon atoms, and whose polyoxyalkylene group is a polyoxyethylene group or a polyoxypropylene group.

  In the present invention, it is preferable not to use a surfactant from the viewpoint of the water resistance of the coating film and the adhesion to the substrate, but the stability of the aqueous dispersion of the acrylic monomer solution of the urethane prepolymer, or In order to increase the stability during polymerization, a small amount of surfactant can be used in combination. Surfactants include anionic surfactants such as fatty acid salts, alkyl sulfate esters, alkylbenzene sulfonates, naphthalene sulfonates, and alkylsulfosuccinates; polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, There are nonionic surfactants such as polyoxyethylene alkylphenyl ether and polyoxyethylene alkylphenyl ester. Moreover, you may use a reactive activator together.

  As a method of dispersing the acrylic monomer solution of the urethane prepolymer in water, dispersion with a normal stirrer is possible, but in order to obtain a uniform aqueous dispersion with a finer particle size, a homomixer, a homogenizer, a disper, A line mixer or the like may be used. After obtaining an aqueous dispersion of the acrylic monomer solution of the urethane prepolymer in this way, a polymerization initiator is added thereto to raise the temperature, and the urethane prepolymer is chained with water within the range of the polymerization temperature of the acrylic monomer. While extending, an acrylic monomer is polymerized to obtain an acrylic composite urethane emulsion composed of a urethane resin and an acrylic resin. The urethane resin has a self-emulsifying group, and the acrylic resin is non-aqueous. Furthermore, since the urethane resin and the acrylic resin are incompatible, an acrylic composite urethane emulsion having a core-shell structure is obtained.

  Further, if necessary, a chain extender other than water may be added at the time of chain extension of the urethane prepolymer to react the urethane prepolymer with the chain extender. As the chain extender, a known chain extender having active hydrogen can be used, and examples thereof include diamines such as ethylenediamine, hexamethylenediamine, cyclohexanediamine, cyclohexylmethanediamine, and isophoronediamine, and hydrazine.

  A known radical polymerization can be applied to the polymerization of the aqueous dispersion. As the polymerization initiator, both a water-soluble initiator and an oil-soluble initiator can be used. When an oil-soluble initiator is used, it is preferably added to an acrylic monomer solution of a urethane prepolymer. These polymerization initiators are usually used in the range of 0.05 to 5% by weight with respect to the acrylic monomer, and the polymerization temperature is preferably 20 to 100 ° C. In the case of a redox initiator, 75 ° C. or lower is sufficient. Examples of the polymerization initiator include azo compounds such as azobisisobutyronitrile and azobisisobutylvaleronitrile, benzoyl peroxide, isobutyryl peroxide, octanoyl peroxide, cumylperoxyoctate, t-butylperoxy- Organic peroxides such as 2-ethylhexanoate, t-butyl hydroperoxide, t-butyl peroxyacetate, lauryl peroxide, di-t-butyl peroxide, di-2-ethylhexyl peroxydine carbonate, There are inorganic peroxide compounds such as potassium sulfate, ammonium persulfate, and hydrogen peroxide. The organic or inorganic peroxide compound can also be used as a redox initiator in combination with a reducing agent. Examples of the reducing agent include L-ascorbic acid, L-sorbic acid, sodium metabisulfite, ferric sulfate, ferric chloride, Rongalite and the like.

  When the polymerization initiator is added, any of a method in which the entire amount is initially charged, a method in which the entire amount is dropped over time, and a method in which a part is initially charged and the remainder is added later may be used. In addition, in order to cut off the polymerization and reduce the residual monomer, it is possible to add a polymerization initiator during the polymerization or after the polymerization is once completed to add the polymerization. At this time, the combination of polymerization initiators can be arbitrarily selected. Known chain transfer agents such as octyl mercaptan, lauryl mercaptan, 2-mercaptoethanol, tertiary dodecyl mercaptan, thioglycolic acid and the like can also be used for the purpose of adjusting the molecular weight in the polymerization of the acrylic monomer.

  The non-volatile content of the water-based resin for colored layers comprising the acrylic composite urethane emulsion of the present invention is preferably 20 to 50% by weight, more preferably 30 to 40% by weight. If the non-volatile content is too large, it will not be sufficiently emulsified, and if it is too small, the resin concentration in the case of an aqueous coating solution for the colored layer may be too low to be used.

  The aqueous coating liquid for the colored layer of the decorative sheet using such a water-based resin is superior in that it improves the interlayer adhesion of the decorative sheet including the formed colored layer, as compared with the conventional aqueous coating liquid. It is a thing.

(2) Pigment The pigment is contained as a colorant in the aqueous coating liquid for the solid colored layer / picture colored layer. As such a colored pigment, an organic or inorganic pigment can be used. For example, examples of yellow pigments include azo pigments such as monoazo, disazo and polyazo, organic pigments such as isoindolinone and quinoxalinedione, inorganic pigments such as yellow lead, yellow iron oxide, cadmium yellow, titanium yellow and antimony yellow Can be used. As the red pigment, azo pigments such as monoazo, disazo and polyazo, organic pigments such as quinacridone, and inorganic pigments such as petals, vermilion, cadmium red and chrome vermilion can be used. As the blue pigment, organic pigments such as phthalocyanine blue and indanthrene blue, and inorganic pigments such as bitumen, ultramarine blue, and cobalt blue can be used. Moreover, as a black pigment, organic pigments, such as aniline black, and inorganic pigments, such as carbon black, can be used. As the white pigment, inorganic pigments such as titanium dioxide, zinc white, and antimony trioxide can be used. Moreover, fillers, such as a silica, volume pigments, such as an organic bead, a neutralizing agent, surfactant, etc. can be contained arbitrarily.

  The mixing ratio of the aqueous resin: pigment is not particularly limited, and is appropriately set within a range where the coating liquid can be appropriately applied.

(3) Water-dispersed isocyanate Water-dispersed isocyanate is contained in a water-based coating liquid for a solid colored layer as a crosslinking agent. In addition, as above-mentioned, you may be contained in the water-system coating liquid for pattern colored layers. The water-dispersed isocyanate is not particularly limited as long as it can be self-emulsified in water. The self-emulsifying polyisocyanate can be obtained, for example, by introducing a hydrophilic group and a hydrophobic group having at least one active hydrogen group capable of reacting with an isocyanate group into the polyisocyanate. Introducing not only hydrophilic groups but also hydrophobic groups, when polyisocyanate is dispersed in water, steric hindrance causes the reaction between water molecules present around it and unreacted NCO groups present nearby. This is to obtain the effect of suppressing the surface chemistry based on the target or its lipophilicity. Examples of the hydrophobic group include higher alcohols having at least one active hydrogen group and hydroxyl group-containing fatty acid esters.

  Examples of the polyisocyanate used in the self-emulsifying type polyisocyanate include phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tetramethylxylene diisocyanate, naphthylene diisocyanate, diphenylmethane diisocyanate and the like, and aromatic diisocyanates composed of these isomers, 1,6 -Aliphatic diisocyanates such as hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, norbornane diisocyanate, 2,4,6-triisocyanate toluene, 2,4, 4'-triisocyanate diphenyl ether, tri Such as triisocyanates such as isocyanate phenyl) methane and the like. Also, isocyanate group-terminated compounds by reaction of polyisocyanates with active hydrogen group-containing compounds, or reactions of these compounds, such as adduct type polyisocyanates, uretdioneation reactions, isocyanurate reactions, carbodiimidization reactions, ureton iminization reactions, buretization. Mention may be made of isocyanate-modified products by reaction and the like, and mixtures thereof. Of these polyisocyanates, aliphatic or cycloaliphatic polyisocyanates, particularly hexamethylene diisocyanate, are preferred from the viewpoints of water dispersion stability, stability of isocyanate groups after water dispersion, non-yellowing, and the like. An isocyanurate ring-containing polyisocyanate having an average number of NCO functional groups of 2 or more in terms of crosslinkability and the like is preferable.

  Such isocyanurate ring-containing polyisocyanates include, for example, raw material polyisocyanates such as tertiary amines, alkyl-substituted ethyleneimines, tertiary alkylphosphines, acetylacene metal salts, and metal salts of various organic acids. The reaction is usually carried out at a reaction temperature of 0 to 90 ° C. in the presence or absence of a solvent using a known uretdione-forming catalyst and / or isocyanurate-forming catalyst such as

  Examples of the cocatalyst include phenolic hydroxyl group-containing compounds and alcoholic hydroxyl group-containing compounds. Examples of the solvent include aromatics such as toluene and xylene, ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and butyl acetate, propylene glycol methyl ether acetate, and ethyl-3-ethoxypropionate. Examples thereof include solvents inert to isocyanate groups such as glycol ether ester.

  Further, the reaction can be stopped by inactivating the catalyst with a reaction terminator. Examples of the reaction terminator include phosphoric acid, methyl paratoluenesulfonate, sulfur and the like.

  Examples of the hydrophilic group of the self-emulsifying polyisocyanate include ionic groups such as cations and anions, and nonionic groups. Examples of nonionic compounds for introducing nonionic groups into polyisocyanates include polyalkylene ether alcohols and polyoxyalkylene fatty acid esters.

  Examples of the active hydrogen-containing compound used as an initiator for the production of polyalkylene ether alcohol include methanol, n-butanol, cyclohexanol, phenol, ethylene glycol, propylene glycol, aniline, trimethylolpropane, and glycerin. Of these, lower alcohols are preferably used from the viewpoint of water dispersion stability.

  Moreover, acetic acid, propionic acid, butyric acid etc. are mentioned as a fatty acid used as an initiator for manufacture of polyoxyalkylene fatty acid ester. Of these, lower fatty acids are preferably used from the viewpoint of water dispersion stability.

  The number of alkylene oxide chains present in the polyalkylene ether alcohol, polyoxyalkylene fatty acid ester and the like is generally 3 to 90, preferably 5 to 50. The alkylene oxide chain may be composed entirely of an ethylene oxide chain, or may be a combination of an ethylene oxide unit and another alkylene oxide unit such as a propylene oxide unit in the entire alkylene oxide chain. In consideration of dispersibility, those containing at least 70% of ethylene oxide units are preferable.

  Examples of ionic compounds for introducing ionic groups into polyisocyanates include fatty acid salts, sulfonate salts, phosphate esters, sulfate ester salts and other anionic compounds, primary amine salts, secondary amine salts, Examples thereof include cationic compounds such as tertiary amine salts, quaternary ammonium salts and pyridinium salts, and amphoteric compounds such as sulfobetaine.

  Examples of higher alcohols for introducing hydrophobic groups into polyisocyanates include octyl alcohol, capryl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol. Cinnamyl alcohol and the like.

  As fatty acids as raw materials of fatty acid esters for introducing hydrophobic groups into polyisocyanates, α-oxypropionic acid, oxysuccinic acid, dioxysuccinic acid, ε-oxypropane-1,2,3-tricarboxylic acid, hydroxyacetic acid, Examples include α-hydroxybutyric acid, hydroxystearic acid, ricinoleic acid, ricinoelaidic acid, ricinostearolic acid, salicylic acid, mandelic acid, etc. Examples of hydroxyl group-containing compounds include methyl alcohol, ethyl alcohol, propyl Alcohol, isopropyl alcohol, butyl alcohol, dodecyl alcohol, lauryl alcohol, etc. are mentioned.

  The self-emulsifying type polyisocyanate of the present invention is produced by a known method, generally at a moderately elevated temperature of 50 to 130 ° C. in the absence of a solvent. If necessary, it is commonly used in the urethane industry. An inert solvent, a catalyst, etc. can also be used.

  Self-emulsifying polyisocyanate can improve water dispersion stability by introducing a hydrophilic chain, and by introducing an appropriate length of lipophilic chain in consideration of the balance with the hydrophilic chain. The reaction between an isocyanate group and water in water can be suppressed by surface chemistry.

  Other substances can be mixed with the self-emulsifying polyisocyanate as required. For example, antioxidants, ultraviolet absorbers, heat resistance improvers, colorants, inorganic and organic fillers, plasticizers, lubricants, antistatic agents, reinforcing materials, catalysts, and the like can be added.

  The self-emulsifying polyisocyanate can be easily made into an aqueous dispersion by mixing with water. In the resulting aqueous dispersion, the isocyanate groups that exist relatively stably after being dispersed in water react with the active hydrogen groups present on the surface of these substrates, so that paints and adhesion with very good adhesion An agent can be obtained.

  In addition, since a considerable amount of time has elapsed after the polyisocyanate is dispersed in water and the isocyanate group has disappeared, polyisocyanate particles having a particle size of about 0.1 to 2.5 μm are stably present in an emulsion state. The film obtained by applying this and drying at room temperature or by heating is hard and tough. For this reason, it can be used as a film or sheet state or as a coating agent for various substrates. When the adhesiveness with the base material is important, it is desirable to apply and use in the state where the isocyanate group exists.

  A water-based coating liquid containing such a type of water-dispersed isocyanate is stable and has a long pot life. In addition to improving the interlayer adhesion of a decorative sheet having a colored layer formed using this water-based coating solution, the weather resistance, the boiling water resistance, and the adhesion between the substrate and the colored layer are increased. This has the effect of improving the adhesive coatability.

  The blending ratio of the aqueous resin: water-dispersible isocyanate is not particularly limited, and is appropriately set within a range where the coating liquid can be appropriately applied.

(4) Solvent Water used as the solvent is industrial water of a grade conventionally used for aqueous coating solutions. A mixed solvent composed of water and alcohol can also be used as a solvent for the aqueous coating solution. Examples of alcohols constituting such a mixed solvent include lower alcohols such as ethanol, isopropyl alcohol and n-propyl alcohol, glycols and esters thereof. These solvents such as lower alcohols, glycols and esters thereof can improve the fluidity of aqueous coating liquid, defoam the aqueous coating liquid, and wet the substrate or solid colored layer that is the object to be coated. It is used for the purpose of improvement, improvement of design property with improvement of wettability, adjustment of drying property, improvement of interlayer adhesion of the manufactured decorative sheet, etc. The type and amount used according to the purpose Etc. are determined. The aqueous coating liquid used in the present invention does not use high-risk aromatic hydrocarbon organic volatile substances such as benzene, toluene, xylene, etc., and also suppresses the use of other organic solvents. Therefore, the occurrence of VOC can be reduced.

  In a mixed solvent composed of water and alcohol or the like, the blending ratio of water: alcohol and the like (for example, isopropyl alcohol, methanol, ethanol, n-propyl alcohol, etc.) = 100: 0 to 20:80 It can be adjusted within the range.

  When the alcohol ratio increases, the water / alcohol ratio increases the drying property by lowering the boiling point and decreasing the vapor pressure, the defoaming action by reducing the surface energy of the ink itself, and the wettability with the substrate. Improvement in adhesion to the base material and improvement in ink transferability, etc., but if the alcohol ratio increases too much, gelation and sedimentation due to emulsion stabilization inhibition and increase in VOC are considered at the time of filing. ing. Moreover, when the water ratio is improved, effects such as improvement of safety can be considered.

  Further, the mixing ratio of the solvent in the aqueous coating liquid is not particularly limited. However, if the ratio of the solvent is small, the fluidity of the ink is lowered and good printability cannot be maintained. Moreover, when the solvent ratio is too high, there may be a problem that the drying property is lowered, the fluidity is too high, and the design property is deteriorated. A more realistic blending ratio is preferably 40 to 1000, preferably 100 to 400, when the weight of the aqueous resin as the binder component and the crosslinking agent is 100. Particularly preferred.

(5) Aqueous coating solution for colored layer of decorative sheet The aqueous coating solution for colored layer of decorative sheet used for the solid colored layer 3 and the pattern colored layer 4 sufficiently exhibits the characteristic effects of the present invention. To the extent possible, waxes, dispersants, antifoaming agents, leveling agents, stabilizers, fillers, lubricants, lubricants, and other additives can be optionally added.

(6) Formation of colored layer (solid colored layer / pattern colored layer) of decorative sheet The solid colored layer 3 and pattern colored layer 4 are provided with the above-described aqueous coating liquid for the colored layer of the decorative sheet by coating or printing. And then dried. More specifically, when an olefin substrate is used as the substrate 2, a functional group (specifically, carboxyl group, carbonyl group, hydroxyl group, excess As shown in FIG. 7, water dispersion in the aqueous coating solution is performed by coating or printing a solid colored layer aqueous coating solution on the substrate and drying and curing the substrate. The solid group 3 is formed by the reaction of the isocyanate group of the system isocyanate 70, the functional group generated on the surface of the base material, and the acrylic composite urethane emulsion 60.

  The adhesion between the solid colored layer and the substrate is the interaction between the functional groups generated by corona treatment on the surface of the substrate and the water adhering to the surface, and carboxyl groups and active hydrogen groups contained in the aqueous resin and curing agent, and It is expressed by a chemical bonding reaction with the functional group such as an isocyanate compound or adhering water.

  The pattern coloring layer 4 is formed by applying or printing an aqueous coating liquid for a pattern coloring layer on the solid coloring layer 3 and then drying and curing it. As coating methods, various known methods such as roll coating, curtain flow coating, wire bar coating, reverse coating, gravure coating, gravure reverse coating, air knife coating, kiss coating, blade coating, smooth coating, comma coating, spray coating. It is possible to use a method such as flow coating or brush coating. Also, as printing methods, it is possible to use various known methods such as relief printing such as gravure, letterpress and flexo, lithographic printing such as lithographic offset and dilitho printing, stencil printing such as silk screen, electrostatic printing and inkjet printing. it can. The solid colored layer 3 is applied or printed so that the film thickness after drying is about 0.1 to 5.0 μm, and the pattern colored layer 4 is about 0 to 10.0 μm after drying. As coated or printed.

(Adhesive layer)
As shown in FIG. 1, the adhesive layer 5 is provided between the colored layer 11 and the transparent resin layer 6, and improves the adhesion between the base material 2 on which the colored layer 11 is formed and the transparent resin layer 6. It has a role as a primer layer or an anchor layer, and has an effect of improving durability and long-term appearance maintenance. Such an action can hold the formed pattern for a long time and is extremely effective.

  The adhesive layer 5 is formed of a water-based coating solution, a solvent-based coating solution, or a solvent-free coating solution. Among these, it is preferable to use a water-based coating liquid or a solvent-free coating liquid, and the adhesive layer 5 formed with the water-based coating liquid has no occurrence of VOC caused by a conventional solvent-based coating liquid. It can contribute to further improving the environmental safety of the decorative sheet.

  As the aqueous coating solution for the adhesive layer, a two-component aqueous coating solution containing a curing agent is preferably used. Examples of the resin used in the aqueous coating solution include aqueous resins such as polyurethane resins and polyester resins.

  In the case of forming the adhesive layer 5 with a solvent-based coating solution or a solvent-free coating solution, a solvent-based or solvent-free coating solution that has been generally used can be used.

  Examples of the resin used in the solvent-based coating liquid include a two-component oily urethane resin, a mixture of an oily acrylic resin and an oily urethane resin, and the like.

  The solventless (non-sol) coating liquid is composed of a polyol compound and a polyisocyanate compound. Examples of the polyol compound include polyester polyol, polyether polyol, polycarbonate polyol, polyacetal polyol, polyacryl polyol, polyester amide polyol, polythioether polyol, polyether ester polyol, polyurethane polyol, polyolefin polyol, polysiloxane polyol and the like. . Examples of the polyisocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, 3,3′-dimethyl-4,4′-biphenylene diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 3,3′-dichloro-4,4′- Biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate Nate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 4,4'- Polyfunctional polyisocyanate compounds such as isocyanurate, biuret and allophanate derived from polyisocyanate monomers such as dicyclohexylmethane diisocyanate and 3,3′-dimethyl-4,4′-dicyclohexylmethane diisocyanate, or trimethylolpropane and glycerin Terminal isocyanate group-containing polyfunctional polymer obtained by reaction with a trifunctional or higher functional polyol compound such as Cyanate compound, and the like.

  The adhesive layer 5 is formed by providing the above-described adhesive layer coating solution on the colored layer 11 by coating or printing, and then drying. As coating methods, various known methods such as roll coating, curtain flow coating, wire bar coating, reverse coating, gravure coating, gravure reverse coating, air knife coating, kiss coating, blade coating, smooth coating, comma coating, spray coating. A method such as flow coating or brush coating can be used, and coating is performed so that the film thickness after drying is about 0.5 to 10 μm.

(Transparent resin layer)
The transparent resin layer 6 is also referred to as a top resin layer, and is provided through the adhesive layer 5 for the purpose of protecting the colored layer 11 from scratches, improving the surface strength of the decorative sheet 1, and imparting a feeling of painting. And laminated on the colored layer 11.

  The resin constituting the transparent resin layer 6 is not particularly limited as long as it is a transparent resin that is formed in close contact with the colored layer 11 via the adhesive layer 5 described above. Preferred are olefin resins. Thus, it is preferable to use a material mainly composed of a polyolefin-based resin for the transparent resin layer 6, and when the material contains a component other than the polyolefin-based resin, the proportion of the polyolefin-based resin is the largest. Included. As the resin other than the olefin resin that can be used as the resin for the transparent resin layer, the same resin material as that used for the substrate 2 can be used. To the resin forming the transparent resin layer 6, known additives such as a colorant, a filler, an ultraviolet absorber, a light stabilizer, a matting agent, an antioxidant, and an antiblocking agent are added as necessary. The

  The transparent resin layer 6 is formed by laminating a transparent resin sheet separately formed on the adhesive layer 5 by various laminating methods such as dry lamination and thermal lamination, or by a melt extrusion coating method. It is laminated by other known methods.

  Further, as shown in FIG. 2, the transparent resin layer 6 may have a multilayer structure of two or more layers. The transparent resin layer 16 formed by laminating two or more layers is advantageous in that different effects can be imparted to the transparent resin layer 6 ′ on the substrate 2 side and the transparent resin layer 6 ″ on the protective layer side. As one specific example, the transparent resin layer 6 ″ on the protective layer side is formed of a resin mainly composed of a fluorine-based resin such as vinylidene fluoride to give excellent surface functions such as stain resistance. The transparent resin layer 6 ′ on the material side can be formed from a thermoplastic acrylic resin or the like, and the adhesion between the adhesive layer 5 and the like can be improved. As another specific example, the transparent resin layer 6 ″ on the protective layer side is formed of a polypropylene resin to which a weathering agent is added to give excellent weather resistance, and the transparent resin layer 6 ′ on the substrate side is given. Can be formed of a polypropylene-based resin containing an elastomer to improve weather resistance and adhesion.

  The two or more transparent resin layers 16 are formed by melt coextrusion of a plurality of resin compositions, or by various lamination methods such as dry lamination and thermal lamination. At this time, as shown in FIG. 3, a transparent resin layer 16 composed of two or more layers can be formed through an adhesive layer 12 acting as a primer layer or an anchor layer. In this case, the adhesive layer 12 is formed by melt coextrusion with the transparent resin layers 6 ′ and 6 ″, or is formed by applying with an aqueous coating solution containing an aqueous urethane resin. , Generation of VOC can be further suppressed.

  The thickness of the transparent resin layer 6 is about 20 to 500 μm, and preferably about 30 to 100 μm.

(Uneven pattern)
The uneven pattern 7 is also referred to as an embossed pattern, and is formed on the surface of the transparent resin layer 6 as necessary, as shown in FIG. In addition, when two or more transparent resin layers 16 are formed as shown in FIGS. 2 and 3, the concavo-convex pattern 7 is formed on the outermost transparent resin layer or formed on the transparent resin layer other than the outermost surface. You can do it.

  The uneven pattern 7 is not particularly limited as long as it is a pattern according to the use of the decorative sheet 1. For example, wood grain conduit groove, wood grain annual ring irregularity, floatation annual ring irregularity, wood grain irregularity, sand grain, satin, hairline, line-like groove, granite cleaved surface texture, textured surface texture, skin squeezing, text, geometry Examples include academic patterns.

  Examples of means for forming the concavo-convex pattern 7 include an embossing method by heat and pressure and a T-die melt extrusion method. The embossing method by heat and pressure is a method in which the surface of the transparent resin layer 6 is heated and softened, the surface is pressed with an embossing plate to form an uneven pattern 7 of the embossing plate, and cooled and fixed. A known single-wafer or rotary embossing machine is used. When forming a concavo-convex pattern by the embossing method, embossing is performed in advance on the transparent resin layer sheet before lamination by laminating, or simultaneously embossing the transparent resin layer sheet (so-called doubling embossing method). To do. When the transparent resin layer 6 is laminated by the T-die melt extrusion method, a cooling roller that also serves as a shaping roller is used, and the uneven pattern 7 is formed simultaneously with the formation and lamination of the transparent resin layer 6. The embossed pattern can also be formed by hairline processing, sandblasting, or the like.

(Partial colored layer)
The partially colored layer 8 is formed in the recessed portion 17 of the concavo-convex pattern 7 by a wiping method. In the wiping method, the coating liquid for the partially colored layer is applied to the entire surface including the recessed portion 17 by the doctor blade coating method or the knife coating method, and then the coating solution for the partially colored layer is applied from the surface other than the recessed portion 17. This is a method of forming the partially colored layer 8 only in the recessed portion 17 by removing the same. As the coating liquid for the partially colored layer, a coating liquid comprising a colored pigment such as an organic pigment, an inorganic pigment, or a bright pigment and a binder resin such as a thermoplastic resin, a thermosetting resin, or an ionizing radiation curable resin. Alternatively, an emulsion-type aqueous coating solution can be used.

  Moreover, the aqueous coating liquid which forms the above-mentioned solid coloring layer 3 and / or pattern coloring layer 4 can also be used preferably, and in such a case, it is more preferable at the point of environmental safety.

(Protective layer)
The protective layer 9 is also referred to as a topcoat layer or an overprint layer (OP layer), and covers the surface of the recessed portion 17 that forms the concavo-convex pattern 7 or the partially colored layer 8 that is formed in the recessed portion 17 so as to cover the decorative sheet 1. It is provided for the purpose of protecting.

  Since the protective layer 9 is used for the purpose of improving physical properties such as scratch resistance and stain resistance, it is preferable to use a thermosetting resin and / or an ionizing radiation curable resin. Although it may be formed with a solvent-based coating solution, it is desirable to form with a water-based coating solution or a solvent-free coating solution in consideration of environmental safety that suppresses the occurrence of VOC. When a solvent-free coating solution is used, an ionizing radiation curable coating solution is preferred. Therefore, similar to the aqueous coating liquid used for the colored layer and adhesive layer described above, an aqueous resin is used, and further, a light stabilizer, an ultraviolet absorber, an antioxidant, a colorant, a dispersant, an antifoaming agent, and a leveling agent. Stabilizers, fillers, lubricants, lubricants, viscosity modifiers, and other additives can be added as desired, using a water solvent or a mixed solvent consisting of water and alcohol, etc., and mixing thoroughly with a mixer etc. The prepared aqueous coating solution is preferably used.

  As the ionizing radiation curable resin, a monomer having a radically polymerizable unsaturated group such as (meth) acryloyl group or (meth) acryloyloxy group or a cationically polymerizable functional group such as epoxy group in the molecule, It consists of a polymer or a polymer (hereinafter collectively referred to as a compound). These monomers, prepolymers, and polymers are used alone or in combination. Such an ionizing radiation curable resin is sufficiently cured when irradiated with an electron beam, but when it is cured by irradiation with ultraviolet rays, a photopolymerization initiator is added as a sensitizer. The addition amount of the photopolymerization initiator is generally about 0.1 to 10 parts by weight with respect to 100 parts by weight of the ionizing radiation curable resin.

  Moreover, the protective layer 9 can also be formed with the reaction type aqueous resin composition, and scratch resistance and adhesiveness with the transparent resin layer 6 can be improved. In particular, when an emulsion type resin is used, a reaction initiator such as a curing agent is protected in the resin composition, and the reaction can be started after coating. Therefore, the protective layer 9 can be formed by coating with a resin composition that is easy to apply and then reacting. As such a reaction type resin composition, for example, as a heat sensitive reaction type resin, so as to suppress a reaction between a main agent composed of a resin having an active hydrogen group, an isocyanate group, solvent water and an alcohol compound, Hydrophilically treated isocyanate-based curing agent, or resin composition obtained by emulsifying isocyanate-based curing agent treated with a blocking agent, or a water-soluble or water-containing epoxy resin having a main agent composed of a resin having an amino group or a carboxylic acid group The resin composition etc. which consist of a dispersible hardening | curing agent can be mentioned.

  The protective layer 9 is provided in order to improve surface properties such as scratch resistance, and the gloss is adjusted by adding a known matting agent such as silica to the coating solution, or the design property such as a feeling of painting. Can be provided. Moreover, in order to provide the protective layer 9 with better weather resistance or light resistance, the layer can be formed using a coating liquid to which an ultraviolet absorber or a light stabilizer is added as necessary. .

  The protective layer 9 is formed by coating and forming the above-described various coating liquids by a known coating method such as a gravure coating method, a reverse roll coating method, a knife coating method, a kiss coating method, or other coating methods. Moreover, it forms by well-known printing methods, such as gravure printing and silk screen printing. The thickness of the formed protective layer 9 is preferably about 0.5 to 40 μm, more preferably 3 to 30 μm.

  If necessary, an anchor layer may be provided between the surface protective layer 6 and the protective layer 9, and the anchor layer preferably contains a polyurethane resin or a polyester resin. It is more preferable to form using the aqueous coating liquid to contain.

(Primer layer)
The primer layer 10 is formed on the back side of the substrate 2 for the purpose of facilitating bonding of the decorative sheet 1 of the present invention to various adherends 15.

  The primer layer 10 is generally made of an acrylic resin, vinyl chloride-vinyl acetate copolymer, polyester, polyurethane, chlorinated polypropylene, chlorinated polyethylene, or the like. The colored layer 11 or the adhesive layer 5 described above is used as the primer layer 10. It is preferable from the viewpoint of environmental safety to use a water-based coating liquid that is preferably employed for the formation.

(Decorative sheet)
The decorative sheet 1 of the present invention having the above-described configuration is used by being laminated on another adherend 15 (backing material).

  As the adherend 15, a three-dimensional article 41 as shown in FIG. 4, an article of various shapes such as a flat plate or curved plate 51, a sheet (or film) as shown in FIG. . Examples of the adherend 15 include wood boards such as wood veneer, wood plywood, particle board and medium density fiber board (MDF), wood boards such as wood fiber board, metals such as iron and aluminum, acrylic, polyester and polystyrene. , Polyolefin, ABS resin, phenolic resin, polyvinyl chloride resin, cellulose resin, rubber and other resins, glass, ceramics such as ceramics, non-cement ceramic materials such as gypsum, fine paper, Japanese paper, carbon, asbestos Nonwoven fabric or woven fabric made of fibers such as potassium titanate, glass, synthetic resin, and the like.

  In the relationship between the decorative sheet 1 and the adherend 15, when the adhesive sheet 1 can be directly bonded to the adherend 15 by heat fusion or the like depending on the type of the base material 2 of the decorative sheet 1 or the presence of the primer layer 10, the decorative sheet 1 And the adherend 15 can be laminated without using an adhesive. However, depending on the type of the base material 2 or the primer layer 10 of the decorative sheet 1, the adherend 15 cannot be directly bonded to the adherend 15 by heat fusion or the like. Are laminated using a suitable adhesive. Examples of the adhesive include vinyl acetate-based and urea-based adhesives.

  Further, as a general lamination method, for example, (a) a method of laminating the adherend 15 by pressing with a pressure roller via an adhesive, (b) Japanese Patent Publication No. 50-19132, Japanese Patent Publication No. 43 As described in JP-A-27488, etc., the decorative sheet 1 is inserted between both male and female molds for injection molding, both molds are closed, the molten resin is injected and filled from the male mold gate, and then cooled. An injection molding simultaneous laminating method in which the decorative sheet 1 is adhered and laminated on the surface of the resin molded product at the same time, (c) an adhesive as described in JP-B-56-45768 and JP-B-60-58014 A vacuum press laminating method in which the decorative sheet 1 is opposed to the surface of the molded product through the pressure and the decorative sheet 1 is laminated on the molded product surface by a pressure difference due to vacuum suction from the molded product side, (d) Japanese Patent Publication No. 61-5895 Gazette, Japanese Patent Publication 3-26 As described in Japanese Patent Publication No. 6 etc., columnar adherence is provided by a plurality of differently oriented rollers while supplying the decorative sheet 1 via an adhesive in the long axis direction of a columnar adherend such as a cylinder or a polygonal column. Examples include a lapping process method in which the decorative sheet 1 is sequentially pressure-bonded and laminated on a plurality of side surfaces constituting the body.

  The various adherends 15 on which the decorative sheet 1 of the present invention is laminated are subjected to a predetermined molding process and the like, and are used as various decorative materials. For example, interior decorations for buildings such as walls, ceilings, floors, surface decorations for furniture such as window frames, doors, handrails, surface decorations for furniture or cabinets for light electrical / OA equipment, vehicle interiors such as cars and trains, aircraft interiors, windows Uses such as glass for cosmetics are listed.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. Hereinafter, “part” means “part by weight”.

(Resin production example 1)
(Step 1) Polycarbonate diol (Kuraray polyol C-) having an average molecular weight of 2,000. 2090: manufactured by Kuraray (the molar ratio of 3-methyl-1,5-pentanediol and 1,6-hexanediol is in the range of 90:10)) 87.71 g, dimethylolbutanoic acid 13.00 g, p-methoxyphenol 0.019 g was charged, heated to 80 ° C. and reacted for 5 hours to obtain an acrylic monomer solution of urethane prepolymer.

  (Step 2) The acrylic monomer solution of the urethane prepolymer was cooled to 40 ° C., and 17.46 g of methoxypolyethylene glycol methacrylate (n = 9) and 8.88 g of triethylamine were added and mixed uniformly.

  (Step 3) 639.76 g of demineralized water was added dropwise to the acrylic monomer solution of the urethane prepolymer to emulsify the urethane prepolymer solution. Since the acrylic monomer became the central part of the micelle and the urethane prepolymer had an emulsifying group, a urethane prepolymer emulsion that was the outermost layer was obtained.

  (Step 4) 2.10 g of potassium persulfate was added to the emulsified urethane prepolymer solution while introducing nitrogen gas into the flask, and the temperature of the dispersion was gradually raised. Heat was generated at around 50 ° C, but after the heat generation had subsided, the temperature was maintained at 75 ° C and reacted for 3 hours to chain extend the urethane prepolymer with water and polymerize the acrylic monomer. The acrylic monomer was the core and the urethane prepolymer was the shell. The acrylic composite type urethane emulsion of Resin Production Example 1 to be a layer was obtained.

(Resin production example 2)
(Step 1) A 4-L 2L separable flask equipped with a condenser, a thermometer, a charging port, and a stirrer was mixed with 170.61 g of ethyl methacrylate, 48.59 g of isophorone diisocyanate, and polycarbonate diol (Kuraray polyol C- (2090: manufactured by Kuraray Co., Ltd.) 109.30 g, dimethylolbutanoic acid 16.20 g, and p-methoxyphenol 0.017 g were charged, heated to 80 ° C. and reacted for 5 hours to obtain an acrylic monomer solution of urethane prepolymer.

  (Step 2) The acrylic monomer solution of the urethane prepolymer was cooled to 40 ° C., 17.47 g of methoxypolyethylene glycol methacrylate (n = 9) and 11.06 g of triethylamine were added and mixed uniformly.

  (Step 3) 637.81 g of demineralized water was added dropwise to the acrylic monomer solution of the urethane prepolymer to emulsify the urethane prepolymer solution. Since the acrylic monomer became the central part of the micelle and the urethane prepolymer had an emulsifying group, a urethane prepolymer emulsion that was the outermost layer was obtained.

  (Step 4) 1.20 g of n-butylamine was added to the emulsified urethane prepolymer solution.

  (Step 5) 1.74 g of potassium persulfate was added while introducing nitrogen gas into the flask, and the temperature of the dispersion was gradually raised. Heat was generated at around 50 ° C, but after the heat generation had subsided, the temperature was maintained at 75 ° C and reacted for 3 hours to chain extend the urethane prepolymer with water and polymerize the acrylic monomer. The acrylic monomer was the core and the urethane prepolymer was the shell. The acrylic composite urethane emulsion of Resin Production Example 2 to be a layer was obtained.

(Resin production example 3)
Using the raw materials described in Table 1 and Table 2 in the same manner as in Resin Production Example 2, an acrylic composite urethane emulsion of Resin Production Example 3 was obtained. Tables 1 and 2 also list the raw materials of Resin Production Examples 1 and 2 in addition to Resin Production Example 3.

(Comparative resin production example 1)
(Step 1) Polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-) (2090: manufactured by Kuraray) 110.65 g, dimethylolpropionic acid 14.85 g, and p-methoxyphenol 0.016 g were charged, heated to 80 ° C., and reacted for 5 hours to obtain an acrylic monomer solution of urethane prepolymer.

  (Step 2) The acrylic monomer solution of the urethane prepolymer was cooled to 40 ° C., 17.47 g of methoxypolyethylene glycol methacrylate (n = 9) and 11.20 g of triethylamine were added and mixed uniformly.

  (Step 3) 637.27 g of demineralized water was added dropwise to the acrylic monomer solution of the urethane prepolymer to emulsify the urethane prepolymer solution. Since the acrylic monomer became the central part of the micelle and the urethane prepolymer had an emulsifying group, a urethane prepolymer emulsion that was the outermost layer was obtained.

  (Step 4) While introducing nitrogen gas into the flask, 1.75 g of potassium persulfate was added, and the temperature of the dispersion was gradually raised. Heat was generated at around 50 ° C, but after cooling, the temperature was maintained at 75 ° C and reacted for 3 hours to carry out chain extension of the urethane prepolymer with water and polymerization of the acrylic monomer. The acrylic monomer was the core part, and the urethane prepolymer was the shell layer. An acrylic composite urethane emulsion of Comparative Resin Production Example 1 was obtained.

(Comparative resin production example 2)
(Step 1) Polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-) (2090: manufactured by Kuraray) 87.71 g, dimethylolbutanoic acid 13.00 g, and p-methoxyphenol 0.019 g were charged, heated to 80 ° C. and reacted for 5 hours to obtain an acrylic monomer solution of urethane prepolymer.

  (Step 2) The acrylic monomer solution of the urethane prepolymer was cooled to 40 ° C., and 6.98 g of methacrylic acid, 10.48 g of methoxypolyethylene glycol methacrylate (n = 9) and 17.09 g of triethylamine were added and mixed uniformly.

  (Step 3) 631.55 g of demineralized water was added dropwise to the acrylic monomer solution of the urethane prepolymer to emulsify the urethane prepolymer solution. Since the acrylic monomer became the central part of the micelle and the urethane prepolymer had an emulsifying group, a urethane prepolymer emulsion that was the outermost layer was obtained.

  (Step 4) While introducing nitrogen gas into the flask, 2.10 g of potassium persulfate was added, and the temperature of the dispersion was gradually raised. Heat was generated at around 50 ° C, but after the heat generation had subsided, the temperature was maintained at 75 ° C and reacted for 3 hours to chain extend the urethane prepolymer with water and polymerize the acrylic monomer. The acrylic monomer was the core and the urethane prepolymer was the shell. An acrylic composite urethane emulsion of Comparative Resin Production Example 2 to be a layer was obtained.

(Comparative resin production example 3)
(Step 1) In a four-necked 2 L separable flask equipped with a condenser, a thermometer, a charging port, and a stirring device, 129.22 g of methyl methacrylate, 62.86 g of n-butyl acrylate, 38.9 g of isophorone diisocyanate, and an average molecular weight of 2000 Of polycarbonate diol (Kuraray polyol C-2090: manufactured by Kuraray Co., Ltd.), dimethylolbutanoic acid 13.00 g, p-methoxyphenol 0.019 g were charged, heated to 80 ° C. and reacted for 5 hours to form a urethane prepolymer. An acrylic monomer solution was obtained.

  (Step 2) The acrylic monomer solution of the urethane prepolymer was cooled to 40 ° C., 17.46 g of methoxypolyethylene glycol methacrylate (n = 9) and 8.88 g of triethylamine were added and mixed uniformly.

  (Step 3) 639.76 g of demineralized water was added dropwise to the acrylic monomer solution of the urethane prepolymer to emulsify the urethane prepolymer solution. Since the acrylic monomer became the central part of the micelle and the urethane prepolymer had an emulsifying group, a urethane prepolymer emulsion that was the outermost layer was obtained.

  (Step 4) While introducing nitrogen gas into the flask, 2.10 g of potassium persulfate was added, and the temperature of the dispersion was gradually raised. Heat was generated at around 50 ° C, but after cooling, the temperature was maintained at 75 ° C and reacted for 3 hours to carry out chain extension of the urethane prepolymer with water and polymerization of the acrylic monomer. The acrylic monomer was the core part, and the urethane prepolymer was the shell layer. An acrylic composite urethane emulsion of Comparative Resin Production Example 3 was obtained.

(Ink production example 1)
To 224.0 g of the acrylic-urethane copolymer obtained in Resin Production Example 1, 235.2 g of titanium oxide JR-806 manufactured by Teika Co., Ltd., 105.0 g of dechlorinated water, and 35.0 g of isopropyl alcohol were added and stirred well. After that, 570 g of glass beads with a particle diameter of 1 mm are charged, and after 60 minutes of meat-shaking with a paint shaker, 17.5 g of a polyurethane-based thickener and 83.3 g of dechlorinated water are mixed, and an aqueous coating for a white solid colored layer An ink for liquid A was obtained.

(Ink production example 2)
After adding 57.6 g of condensed azo pigment, 73.8 g of dechlorinated water and 40.2 g of isopropyl alcohol to 398.4 g of the acrylic-urethane copolymer obtained in Resin Production Example 1, the particle size is 1 mm. After 570 g of glass beads were charged and meat meat was minced with a paint shaker for 60 minutes, 15 g of polyurethane-based thickener and 15 g of dechlorinated water were mixed to obtain an aqueous coating liquid B ink for a yellow pattern colored layer.

(Ink production example 3)
Using the acrylic-urethane copolymer obtained in Resin Production Example 2, an ink for aqueous coating liquid C for white solid colored layer was obtained in the same manner as in Ink Production Example 1.

(Ink production example 4)
Using the acrylic-urethane copolymer obtained in Resin Production Example 2, an ink for aqueous coating liquid D for yellow pattern colored layer was obtained in the same manner as in Ink Production Example 2.

(Ink production example 5)
Using the acrylic-urethane copolymer obtained in Resin Production Example 3, an ink for aqueous coating liquid E for white solid colored layer was obtained in the same manner as in Ink Production Example 1.

(Comparative ink production example 1)
Using the acrylic-urethane copolymer obtained in Comparative Resin Production Example 3, an ink for aqueous coating liquid F for white solid colored layer was obtained in the same manner as in Ink Production Example 1.

(Comparative ink production example 2)
Using the acrylic-urethane copolymer obtained in Comparative Resin Production Example 3, an ink for aqueous coating liquid G for yellow pattern colored layer was obtained in the same manner as in Ink Production Example 2.

(Comparative ink production example 3)
Using the acrylic-urethane copolymer obtained in Comparative Resin Production Example 4, an ink for aqueous coating liquid H for a white solid colored layer was obtained in the same manner as in Ink Production Example 1.

(Comparative ink production example 4)
Using the acrylic-urethane copolymer obtained in Comparative Resin Production Example 4, an ink for aqueous coating liquid I for yellow pattern colored layer was obtained in the same manner as in Ink Production Example 2.

(Comparative ink production example 5)
Using the acrylic-urethane copolymer obtained in Comparative Resin Production Example 5, an attempt was made to obtain an aqueous coating liquid ink for a white solid colored layer in the same manner as in Ink Production Example 1. There were problems such as poor pigment dispersion and ink stability (thickening with time), and the ink was not used as a water-based ink for a colored layer of a decorative sheet.

Example 1
Polyurethane-based elastomer-colored sheet with a thickness of 60 μm with corona discharge treatment on both sides as the base material 2 and a polyurethane-based aqueous coating liquid for primer layer (using isocyanate-based curing agent) on one side by gravure printing Was applied and dried to form a primer layer of about 1.0 μm. Also, on the other surface on which the primer layer was formed, the aqueous coating liquid A for the solid colored layer and the aqueous coating liquid B for the pattern colored layer, which were blended as follows, were sequentially applied and dried by gravure printing, and about 2.0 μm The solid colored layer 3 and the pattern colored layer 4 of about 0.5 μm were sequentially formed.

  Applying and drying a polyester solvent-based coating solution (using isocyanate curing agent) for the adhesive layer of the following composition by gravure printing on one side of a transparent polypropylene film with a thickness of 80μm that has been subjected to corona discharge treatment on both sides Then, an adhesive layer 5 having a thickness of about 10.0 μm was formed.

  Further, the transparent resin layer 6 was formed by laminating the base material 2 and a transparent polypropylene film having a thickness of 80 μm by a dry laminating method so that the surfaces of the pattern coloring layer 4 and the adhesive layer 5 were bonded together. Next, an uneven pattern 7 is formed on the surface of the laminated sheet by embossing, the corona treatment is applied to the embossed surface, and then a polyurethane-based aqueous coating liquid for a colored layer (using an isocyanate curing agent is used) by a printing method on the embossed recess ), And a polyacrylic aqueous coating liquid for protective layer (using an isocyanate curing agent) is applied and dried by gravure printing on the colored layer, and a protective layer 9 of about 5.5 μm is formed. Formed. Then, the decorative sheet of Example 1 was obtained by curing at a temperature of 25 ° C. for 7 days.

An aqueous coating solution A for a solid colored layer ;
Ink obtained in Ink Production Example 1: 100 parts water-dispersed isocyanate resin (manufactured by Sumika Bayer Urethane Co., Ltd., Bihydur 3100): 3.36 parts Diluting solvent (water / isopropyl alcohol = 7/3): 15 parts
Water-based coating liquid B for pattern colored layer ;
Ink obtained in Ink Production Example 2: 100 parts Diluting solvent (water / isopropyl alcohol = 5/5): 15 parts

(Example 2)
In the same manner as in Example 1, a primer layer 1, a solid colored layer 3, and a pattern colored layer 4 were formed on a substrate 2. Furthermore, a polyester solvent-based coating liquid for an adhesive layer (using an isocyanate curing agent) was applied and dried on the pattern coloring layer 4 by a gravure printing method to form an adhesive layer 5 having a thickness of about 3.0 μm. . On the adhesive layer 5, a resin obtained by adding 0.2% by weight of a phenol-based antioxidant, 0.3% by weight of a hindered amine light stabilizer and 0.2% by weight of an anti-blocking agent to random-polymerized polypropylene was heated to 200 ° C. A transparent resin layer 6 was formed by extruding in a molten state from a T-die and laminating to a thickness of 80 μm by a melt extrusion coating method. Next, an uneven pattern 7 is formed on the surface of the laminated sheet by embossing, the corona treatment is applied to the embossed surface, and then a polyacrylic aqueous coating liquid for the protective layer (using an isocyanate curing agent) is applied by a gravure printing method. Application and drying were performed to form a protective layer 9 having a thickness of about 5.5 μm. Then, the decorative sheet of Example 2 was obtained by curing at a temperature of 25 ° C. for 7 days.

(Example 3)
The aqueous coating solution C was used in place of the aqueous coating solution A for the solid colored layer of Example 2, and the aqueous coating solution D was used in place of the aqueous coating solution B for the pattern colored layer. Otherwise, the decorative sheet of Example 3 was obtained in the same manner as Example 2.

Water-based coating liquid C for solid colored layer ;
Ink obtained in Ink Production Example 3: 100 parts water-dispersed isocyanate resin (manufactured by Sumika Bayer Urethane Co., Ltd., Bihydur 3100): 3.36 parts Diluting solvent (water / isopropyl alcohol = 7/3): 15 parts
Water-based coating liquid D for pattern colored layer ;
Ink obtained in Ink Production Example 4: 100 parts Diluting solvent (water / isopropyl alcohol = 5/5): 15 parts

Example 4
The aqueous coating liquid E was used instead of the aqueous coating liquid A for the solid colored layer of Example 2, and the aqueous coating liquid D was used instead of the aqueous coating liquid B for the pattern colored layer. Otherwise, the decorative sheet of Example 4 was obtained in the same manner as Example 2.

Water-based coating liquid E for solid colored layer ;
Ink obtained in Ink Production Example 5: 100 parts Water-dispersed isocyanate resin (manufactured by Sumika Bayer Urethane Co., Ltd., Bihydur 3100): 3.36 parts Diluting solvent (water / isopropyl alcohol = 7/3): 15 parts

(Example 5)
Instead of the polyester solvent-based coating liquid (use of isocyanate curing agent) in Example 4, a polyester-based aqueous coating liquid (use of isocyanate curing agent) was used. Otherwise, the decorative sheet of Example 5 was obtained in the same manner as Example 4.

(Comparative Example 1)
Instead of the aqueous coating liquid A for the solid colored layer of Example 2, the aqueous coating liquid F for the solid colored layer is replaced with the aqueous coating liquid B for the colored pattern layer, and the aqueous coating liquid for the pattern colored layer. Liquid G was used. Otherwise, the decorative sheet of Comparative Example 1 was obtained in the same manner as Example 2.

An aqueous coating solution F for a solid colored layer ;
Ink obtained in Comparative Ink Production Example 1: 100 parts water-dispersed isocyanate resin (manufactured by Sumika Bayer Urethane Co., Ltd., Bihydur 3100): 3.36 parts Diluting solvent (water / isopropyl alcohol = 7/3): 15 parts
Water-based coating solution G for pattern coloring layer ;
Ink obtained in Comparative Ink Production Example 2: 100 parts diluted solvent (water / isopropyl alcohol = 5/5): 15 parts (Comparative Example 2)
In place of the aqueous coating liquid A for the solid colored layer of Example 2, the aqueous coating liquid H for the solid colored layer is replaced with the aqueous coating liquid B for the colored pattern layer. Liquid I was used. Otherwise, the decorative sheet of Comparative Example 2 was obtained in the same manner as Example 2.

An aqueous coating solution H for solid colored layers ;
Ink obtained in Comparative Ink Production Example 3: 100 parts Water-dispersed isocyanate resin (manufactured by Sumika Bayer Urethane Co., Ltd., Bihydur 3100): 3.36 parts Diluting solvent (water / isopropyl alcohol = 7/3): 15 parts
Water-based coating liquid I for pattern coloring layer ;
Ink obtained in Comparative Ink Production Example 4: 100 parts Diluting solvent (water / isopropyl alcohol = 5/5): 15 parts (Method for evaluating interlayer adhesion after weather resistance test)
Evaluation of interlayer adhesion after the weather resistance test of each decorative sheet obtained in Examples 1 to 5 and Comparative Examples 1 to 2 was performed by the following method. The obtained results are shown in Table 5.

The interlaminar adhesion after the weathering test is a decorative sheet 1 cut to 1 inch in width after the weathering test, and the base material 2 and the transparent resin layer 6 of the test piece are used with an INSTRON 5500 tensile tester. Evaluated by the peel strength pulled under the condition of an opening angle of 180 ° between the substrate 2 and the transparent resin layer 6 in an atmosphere of 25 ° C. with a tensile speed of 100 mm / min. Those with 5N or more and less than 10N were represented by Δ, and those with less than 5N were represented by ×. In the weather resistance test, the decorative sheet 1 test piece was set on a metal weather manufactured by Daipura Wintes Co., Ltd., and the light conditions (illuminance: 60 mW / cm ² , black panel temperature 63 ° C., layer humidity 50% RH) After 20 hours at a condensation condition (illuminance: 0 mW / cm ² , black panel temperature 30 ° C., in-layer humidity 98% RH) for 4 hours and after a 50 hour test under water spray conditions (10 seconds before and after the condensation condition). And kept at 25 ° C. and 50% RH for 2 days.

(Made decorative sheet)
As shown in Table 5, in the decorative sheets 1 of Examples 1 to 5, since the solid colored layer 3 and the pattern colored layer 4 are formed of the aqueous coating solution of the present invention, the interlayer between the weathered test is also present. It was excellent in adhesion. Furthermore, the decorative sheets 1 of Examples 1 to 5 were those in which the occurrence of VOC was suppressed, and the safety of the working environment and the environmental safety in the living space at the time of manufacturing the decorative sheet were improved.

It is sectional drawing which shows an example of the laminated constitution of the decorative sheet of this invention. It is sectional drawing which shows another example of the laminated constitution of the decorative sheet of this invention. It is sectional drawing which shows another example of the layer structure of the decorative sheet of this invention. It is sectional drawing which shows an example of embodiment of the decorative sheet of this invention. It is sectional drawing which shows another example of embodiment of the decorative sheet of this invention. It is a schematic diagram which shows the acrylic complex type urethane emulsion which comprises the water-system coating liquid of this invention. It is a schematic diagram which shows the adhesion mechanism at the time of apply | coating the aqueous coating liquid of this invention on a base material, and forming a colored layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Decorative sheet 2 Base material 3 Solid colored layer 4 Picture colored layer 5 Adhesive layer 6, 6 ', 6 "Transparent resin layer 7 Concavity and convexity 8 Partial colored layer 9 Protective layer 10 Primer layer 11 Colored layer 12 Adhesive layer 15 Adhering body 16 Transparent resin layer composed of multiple layers 17 Recessed part 41 Three-dimensional article 51 Plate material 60 Acrylic composite urethane emulsion 61 Urethane composition part (urethane part)
62 Part of acrylic composition (acrylic part)
65 Adhesive acrylic composite urethane emulsion 70 Water dispersible isocyanate

Claims (9)

At least a decorative sheet in which a base material, a colored layer, an adhesive layer, and a transparent resin layer are laminated in this order,
The colored layer is formed of an aqueous coating solution containing an acrylic composite urethane emulsion,
The acrylic composite urethane emulsion has at least (A) isophorone diisocyanate, (B) 3-methyl-1,5-pentanediol and 1,6-hexanediol as constituent components, and 3-methyl-1,5- Polycarbonate polyol having a molar ratio of pentanediol to 1,6-hexanediol in the range of 95: 5 to 75:25, and (C) a general formula having two or more hydroxyl groups and one or more carboxyl groups in the molecule It is comprised from the urethane resin comprised from the compound represented by (1), and the acrylic resin comprised from ethyl methacrylate, The weight ratio of urethane resin: acrylic resin is the range of 40: 60-60: 40. ,And,
The acrylic composite urethane emulsion has a structure in which a urethane resin composition is located on the surface of an acrylic resin composition, and the weight average molecular weight of the urethane resin composition is 40,000 to 100,000 Sheet.

  2. The decorative sheet according to claim 1, wherein the estimated glass transition temperature of the acrylic resin of the acrylic composite urethane emulsion is 40 to 80 ° C.   The decorative sheet according to claim 1 or 2, wherein the base material comprises a polyolefin-based elastomer as a main component, and the transparent resin layer comprises a polyolefin-based resin as a main component.   The decorative sheet according to any one of claims 1 to 3, wherein an uneven pattern is formed on a surface side of the transparent resin layer.   The decorative sheet according to claim 4, wherein a colored layer is formed in the recessed portion of the uneven pattern.   The decorative sheet according to any one of claims 1 to 5, wherein a surface protective layer is formed on an outermost surface of the transparent resin layer.   The decorative sheet according to any one of claims 1 to 6, wherein a back surface primer layer is formed on the back surface of the base material. At least (A) isophorone diisocyanate, (B) 3-methyl-1,5-pentanediol and 1,6-hexanediol as constituents, and 3-methyl-1,5-pentanediol and 1,6-hexanediol And a compound represented by the general formula (1) having two or more hydroxyl groups and one or more carboxyl groups in the molecule (C) and a polyol having a molar ratio of 95: 5 to 75:25 An acrylic composite urethane emulsion composed of a urethane resin composed of an acrylic resin having ethyl methacrylate as a constituent component, the urethane resin composition being located on the surface of the acrylic resin composition, Urethane resin: acrylic resin weight ratio of 40: 60-60: 40, estimated glass transition temperature of acrylic resin There made 40 to 80 ° C., acrylic composite type urethane emulsion weight average molecular weight of the urethane resin is 40,000-100,000,
An aqueous resin composition for a colored layer of a decorative sheet, wherein the acrylic composite urethane emulsion has a structure in which the urethane resin composition is located on the surface of the acrylic resin composition.

An aqueous coating liquid for a colored layer of a decorative sheet, comprising the aqueous resin composition for a colored layer of a decorative sheet according to claim 8.

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