JP5217105B2 - Decorative sheet - Google Patents

Description

  The present invention relates to a decorative sheet used for interiors of buildings, interiors of joinery, interiors of vehicles, and the like. More specifically, the present invention relates to a decorative sheet that can be suitably used in a molding method that requires heat, such as vacuum molding or injection molding.

  Conventionally, a resin layer (first resin layer) on which a colored layer is formed and a resin layer (second resin layer) different from the resin layer are bonded by an adhesive so as to sandwich the colored layer. Decorative sheets are used in various applications (for example, Patent Document 1).

Currently, decorative sheets having such a structure are used to decorate automobile interior parts and various parts of system kitchens, and these parts are formed by vacuum molding or injection molding. Often done. When such a molding method is adopted, a method of attaching a decorative sheet in a mold in advance and bonding the decorative sheet to the surface of the molded product at the same time when the vacuum molding method or the injection molding method is performed (so-called Simultaneous decoration) is often adopted.
JP 2001-232703 A

  In the decorative sheet formed by adhering the first resin layer having the colored layer as described above and the second resin layer different from the first resin layer with an adhesive so as to sandwich the colored layer. Contains a solvent in the colored layer and the adhesive. The reason why the solvent is contained in the colored layer (in the printing ink for forming the colored layer) is to adjust the viscosity of the ink, improve the familiarity with the first resin, and improve the printing characteristics. In addition, the solvent is contained in the adhesive in the same manner as the solvent is contained in the colored layer, the viscosity of the adhesive is adjusted appropriately, the first resin layer on which the colored layer is formed, and This is to improve the familiarity with the second resin layer to be bonded, and to prevent the reduction of bubbles remaining in the decorative sheet (so-called air bleeding (biting)) when these are bonded.

  However, when a decorative sheet is designed taking into consideration only the printing characteristics of the colored layer and air stain (biting) during bonding, a large amount of solvent may remain in the decorative sheet. Then, when the decorative sheet in which a large amount of the solvent remains is used in the so-called simultaneous decorating method by the above-described vacuum forming method or injection molding method, the decorative sheet is heated, so the solvent remaining in the decorative sheet is vaporized. In some cases, the decorative sheet moves to the surface side, and the design property is impaired.

  In other words, there is a so-called trade-off relationship between the problem of printing characteristics and air stagnation (biting) and the problem of solvent vaporization during vacuum molding and injection molding. So it's not a good decorative sheet.

  The inventor of the present application found such a problem by himself and completed the present invention to solve this problem. That is, the present invention has a coloring layer and is free from problems of printing characteristics and air bleeding (biting) in a decorative sheet constituted by bonding a resin using an adhesive, and yet is vacuum. Even if it is a case where it is used in a shaping | molding method or an injection molding method and it heats, it makes it a main subject to provide the decorative sheet which does not disturb the design by the vaporization of a solvent.

The present invention for solving the above-mentioned problems has a first resin layer on which a colored layer is formed and a second resin layer, and the first resin layer is sandwiched between the colored layers formed on the first resin layer. A decorative sheet in which one resin layer and a second resin layer are bonded with an adhesive, and the sum of the thickness of the colored layer formed on the first resin layer and the thickness of the adhesive is 5 to 30 μm. And the sum of the amount of the solvent remaining in the colored layer and the amount of the solvent remaining in the adhesive is 10 to 80 mg / m ² .

  In the decorative sheet of the present invention, the ratio of the thickness of the colored layer to the thickness of the adhesive is the thickness of the colored layer / the thickness of the adhesive = 1/10 to 3/1. Is preferred.

  The decorative sheet of the present invention is preferably used in a vacuum molded product or an injection molded product.

The decorative sheet of the present invention has a first resin layer on which a colored layer is formed and a second resin layer, and the first resin layer and the first resin layer so as to sandwich the colored layer formed on the first resin layer. The second resin layer is bonded with an adhesive, and the sum of the thickness of the colored layer formed on the first resin layer and the thickness of the adhesive is limited to a predetermined range (5 to 30 μm). Furthermore, the sum of the amount of solvent remaining in the colored layer and the amount of solvent remaining in the adhesive is also limited to a predetermined range (10 to 80 mg / m ² ). According to the present invention, since the sum of the thicknesses of the colored layer and the adhesive layer in which the solvent is used is controlled and the sum of the amount of the solvent remaining therein is also controlled, the solvent is contained. , Specifically, the printing characteristics of the colored layer and the prevention of air stagnation (biting) when adhering with an adhesive, while the demerit by containing a large amount of solvent, specifically Therefore, it is possible to provide a well-balanced decorative sheet that does not cause a problem that the residual solvent is vaporized by heat during vacuum molding or injection molding to impair the design.

  In the decorative sheet of the present invention, the ratio of the thickness of the colored layer to the thickness of the adhesive is within a predetermined range (colored layer thickness / adhesive thickness = 1/10 to 3/1). ), It is possible to effectively prevent air stagnation (biting) that occurs when the first resin layer and the second resin layer are bonded using an adhesive, and to provide good designability by the colored layer. Can be.

  In view of the above characteristics of the decorative sheet of the present invention, it goes without saying that it is preferably used in a vacuum molded product or an injection molded product.

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

  FIG. 1 is a schematic cross-sectional view showing the configuration of an example of the decorative sheet of the present invention.

  FIG. 2 is a schematic cross-sectional view showing another configuration of the decorative sheet of the present invention.

As shown in FIGS. 1 and 2, the decorative sheet 10 of the present invention includes a first resin layer 11 in which a colored layer 13 including a solid colored layer 13 a and a pattern colored layer 13 b is formed, and a second resin layer 12. And the first resin layer 11 and the second resin layer 12 are bonded by an adhesive 14 so as to sandwich the colored layer 13 formed on the first resin layer 11, The sum of the thickness of the colored layer 13 formed on the resin layer and the thickness of the adhesive 14 is 5 to 30 μm, and further, the amount of the solvent remaining in the colored layer 13 and the residual in the adhesive 14. It is characterized in that the sum of the amount of the solvent is 10 to 80 mg / m ² .

  Here, the decorative sheet 10 shown in FIG. 1 and FIG. 2 is only the difference in whether the first resin layer 11 on which the colored layer 13 is formed is arranged on the front side or the back side of the decorative sheet 10. Which is adopted can be appropriately selected according to the application field of the decorative sheet.

  Hereinafter, the decorative sheet 10 of this invention is demonstrated for every structure.

(First resin layer)
The first resin layer 11 is essential for the decorative sheet 10 of the present invention and serves as a base for the decorative sheet 10.

Examples of the material used for the first resin layer 11 include polyolefin resins, polyester resins, acrylic resins, and polyvinyl chloride. Among these, when the decorative sheet 10 is used for applications in which weather resistance, surface gloss (high gloss), surface hardness, and further vacuum formability are important, an acrylic resin is used as the first resin layer 11 layer. On the other hand, when used in applications where low gloss and V-cut processability are important, it is preferable to use a polyolefin resin or a polyester resin.
It is preferable to use polyolefin resin or polyester resin. These materials have high safety and are preferably used from the viewpoint of the environment because no chlorine-based gas is generated when the manufactured decorative sheet is disposed of by incineration and disposal.

  Moreover, as shown in FIG. 1, when arrange | positioning the 1st resin layer 11 on the surface side of the decorative sheet 10, the said 1st resin layer 11 needs to be transparent. This is because the colored layer 13 formed on the first resin layer 11 can be recognized.

  On the other hand, as shown in FIG. 2, when the first resin layer 11 is disposed on the back side of the decorative sheet 10 (that is, the side in contact with the treatment object to which the decorative sheet is attached), the first resin layer 11 is arranged. Is preferably colored and opaque. The stability of the color tone of the colored layer 13 to be described later can be ensured, and when the surface hue of the processed material to which the decorative sheet is applied varies, the hue of the dispersed surface is well concealed. Because you can.

  As the resin for forming the first resin layer 11, it is preferable to use a transparent polyolefin resin, for example, polyethylene (low density or high density), polypropylene, polymethylpentene, polybutene, ethylene-propylene copolymer, A highly crystalline non-elastomeric polyolefin resin such as propylene-butene copolymer or various olefinic thermoplastic elastomers can be used. As the olefin-based thermoplastic elastomer, for example, those described in the following (1) to (7) can be used.

  (1) As described in Japanese Patent Publication No. 6-23278, (A) as a soft segment, the number average molecular weight Mn is 25,000 or more and the ratio Mw / Mn ≦ 7 of the weight average molecular weight Mw and the number average molecular weight Mn 10 to 90% by weight of atactic polypropylene soluble in boiling heptane, and (B) 90 to 10% by weight of isotactic polypropylene insoluble in boiling heptane having a melt index of 0.1 to 4 g / 10 min as a hard segment. Soft polypropylene made of a mixture of Among these types of olefinic thermoplastic elastomers, so-called “necking” is unlikely to occur, and those having good suitability when formed into various shapes or embossed by heating and pressurization are isotactic polypropylene and atactic polypropylene. In the mixture, the mixing ratio of isotactic polypropylene and atactic polypropylene is 5% by weight or more and 50% by weight or less in terms of the weight ratio of atactic polypropylene.

  The polypropylene-based olefinic thermoplastic elastomer itself is already known, but when used in a conventionally known application such as a packaging container, the weight ratio of atactic polypropylene serving as a soft segment is 5 in order to emphasize strength. Less than wt% was used exclusively. However, if this is applied to a new application such as V-cut processing or molding into a three-dimensional shape or a concavo-convex shape, necking occurs as described above, and good processing is impossible. Therefore, contrary to the conventional design of the composition, by setting the weight ratio of atactic polypropylene to 5% by weight or more in the polypropylene-based olefin-based thermoplastic elastomer, V-cut processing, three-dimensional shape, It is possible to eliminate defects such as uneven deformation of the sheet due to necking when forming into a rugged article surface shape, and the resulting wrinkles and distortion of the pattern. In particular, the case where the weight ratio of atactic polypropylene is 20% by weight or more is good. On the other hand, if the weight ratio of atactic polypropylene increases too much, the sheet itself is easily deformed, and when the sheet is passed through a printing machine, the sheet is deformed, the pattern is distorted, and the color becomes unregistered in the case of multicolor printing. Such defects are likely to occur. Further, it is not preferable because it is easily broken during molding. The upper limit of the weight ratio of atactic polypropylene is to print decoration layers, etc. using a normal rotary printing machine such as rotary gravure printing, and also to embossing sheets, vacuum forming, V-cut processing, simultaneous injection molding, etc. Is used, it is 50% by weight or less, more preferably 40% by weight or less.

  (2) A thermoplastic elastomer comprising an ethylene-propylene-butene copolymer resin. Here, as the butene, any of three structural isomers of 1-butene, 2-butene, and isobutylene can be used. As a copolymer, it is a random copolymer and contains a part of amorphous part. Preferable specific examples of the ethylene-propylene-butene copolymer include the following (i) to (iii).

  (I) Those described in JP-A-9-1111055. This is a random copolymer of a terpolymer of ethylene, propylene and butene. The weight ratio of the monomer component is 90% by weight or more of propylene. The melt flow rate is preferably 1 to 50 g / 10 min at 230 ° C. and 2.16 kg. Then, 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 is added to 100 parts by weight of such a ternary random copolymer. 003 to 0.3 parts by weight are melt kneaded.

  (Ii) Those described in JP-A-5-77371. This is a terpolymer of ethylene, propylene and 1-butene, and 20 to 100% by weight of amorphous polypropylene having a propylene component content of 50% by weight or more, and 80 to 0% by weight of crystalline polypropylene. % Addition.

  (Iii) Those described in JP-A-7-316358. This is a terpolymer of ethylene, propylene, and 1-butene, and the content of propylene and / or 1-butene is 50 to 100% by weight of the low crystalline polymer. 0.5% by weight of an oil gelling agent such as N-acylamino acid amine salt or N-acylamino acid ester is added to a composition in which 80 to 0% by weight of crystalline polyolefin such as isotactic polypropylene is mixed. It will be.

  In addition, ethylene-propylene-butene copolymer resin may be used independently and may mix and use other polyolefin resin further as needed to said (i)-(iii).

  (3) As described in JP-B 53-21021, (A) an olefin polymer (crystalline polymer) such as polyethylene, polypropylene, polymethylpentene or the like is used as a hard segment, and (B) partially crosslinked ethylene Monoolefin copolymer rubber such as propylene copolymer rubber and unsaturated ethylene-propylene-nonconjugated diene terpolymer rubber is used as a soft segment, and these are uniformly blended and mixed. In addition, it mixes in the ratio of monoolefin rubber / olefin polymer = 50 / 50-90 / 10 (weight ratio).

  (4) (B) Uncrosslinked monoolefin copolymer rubber (soft segment) and (A) Olefin copolymer (crystalline, hard segment) and crosslinked as described in JP-B-53-34210 An olefin-based elastomer that is mixed with an agent, heated, and partially dynamically crosslinked while applying shear stress. Note that (B) monoolefin rubber / (A) olefin copolymer = 60/40 to 80/20 (weight ratio).

  (5) Mixing and heating with peroxides such as (A) isotactic polypropylene, propylene-ethylene copolymer, propylene-butene-1 copolymer, etc., as described in JP-B-56-15741, etc., reduces the molecular weight. Mixing and heating with peroxide-decomposable olefin polymer (hard segment) to increase fluidity and (B) peroxides such as ethylene-propylene copolymer rubber and ethylene-propylene-nonconjugated diene terpolymer rubber Peroxide-crosslinked monoolefin copolymer rubber (soft segment) that crosslinks to reduce fluidity, (C) Crosslinks with peroxides such as polyisobutylene, butyl rubber, etc. will not crosslink, and fluidity will remain unchanged. Peroxide non-crosslinked hydrocarbon rubber (soft segment and fluidity modifying component), and (D) Fins, napthenic mineral oil-based softening agent for aromatic and the like, mixed with the city, olefin elastomer obtained by dynamically heat-treated in the presence of an organic peroxide. (A) is 90 to 40 parts by weight, (B) is 10 to 60 parts by weight, and (A) + (B) = 100 parts by weight, and (C) and / or (D) is 5 The blending ratio is ˜100 parts by weight.

  (6) An olefinic thermoplastic elastomer comprising an ethylene-styrene-butylene copolymer as described in JP-A-2-139232.

  (7) The olefinic thermoplastic elastomer according to any one of (1) to (6), wherein a hydroxyl group and / or a carboxyl group is provided as a polar group. For example, an olefinic thermoplastic elastomer having a hydroxyl group introduced by graft polymerization of an ethylene-vinyl alcohol copolymer or the like, or an olefinic thermoplastic elastomer having a carboxyl group introduced by a copolymer of maleic acid, fumaric acid, itaconic acid or the like. Is used. Either one or both of these hydroxyl groups and carboxyl groups may be used in combination, and these polar groups have the effect of improving the adhesion with other layers such as a decorative layer such as a picture print layer and an adhesive layer.

  Examples of polyolefin resin films made of these polyolefin resins include stretched and non-stretched films, and unstretched types are preferably used. This unstretched type film has flexibility and is excellent in processing suitability such as lapping, V-cut processing, vacuum forming, injection molding simultaneous lamination, etc., and also has excellent heat shrinkage rate. It is suitably used as the first resin layer 11.

  Acrylic resins include poly (meth) methyl acrylate, poly (meth) ethyl acrylate, poly (meth) acrylate propyl, poly (meth) acrylate butyl, methyl (meth) acrylate- (meth) acrylic acid (Meth) such as butyl copolymer, (meth) ethyl acrylate- (meth) butyl acrylate copolymer, ethylene- (meth) methyl acrylate copolymer, styrene- (meth) methyl acrylate copolymer Examples thereof include a resin comprising a homopolymer or a copolymer containing an acrylic ester. In addition, (meth) acryl means acryl or methacryl. These acrylic resins are used in the first resin layer 11 as a single layer or a mixture of two or more types as a single layer or a laminate of two or more layers.

  Examples of the polyester resin include thermoplastic polyester resins such as polyethylene terephthalate, polybutylene terephthalate, ethylene terephthalate-isophthalate copolymer, and polyarylate.

  The material of the first resin layer 11 described above includes various additives such as a colorant, a filler, a foaming agent, a flame retardant, a lubricant, an antioxidant, an ultraviolet absorber, and a light stabilizer as necessary. It may be blended.

  The colorant used as an additive plays a role of giving the first resin layer 11 a color necessary as a decorative sheet. A colorant is selected according to the use, and the first resin layer 11 can be colored and transparent or colored and opaque. Coloring agents include titanium white, zinc white, petal, vermilion, ultramarine blue, cobalt blue, titanium yellow, carbon black and other inorganic pigments, isoindolinone, banza yellow A, quinacridone, permanent red 4A, phthalocyanine blue, and other organic pigments. A pigment or dye, a metal pigment made of foil powder such as aluminum or brass, a pearlescent pigment made of foil powder such as titanium dioxide-coated mica or basic zinc carbonate, or the like is used. Moreover, you may add an inorganic filler as needed, and powders, such as calcium carbonate, barium sulfate, clay, talc, silica (silicon dioxide), and alumina (aluminum oxide), etc. are mentioned. The addition amount of the colorant is usually about 1 to 50 parts by weight with respect to 100 parts by weight of the resin material for the first resin layer 11 described above.

  The first resin layer 11 can be formed into a sheet from the above-described resin material by a film forming method such as a calendar method, an inflation method, or a T-die extrusion method.

  The thickness of the formed first resin layer 11 is arbitrarily set based on the use of the decorative sheet and the required performance. For example, the thing of the range of about 20-300 micrometers is applied.

  The surface of the first resin layer 11 thus formed may be subjected to easy adhesion treatment such as corona discharge treatment, plasma treatment, and ozone treatment.

(Colored layer)
The colored layer 13 is a layer formed on the first resin layer 11 described above, and includes a solid colored layer 13a and / or a pattern colored layer 13b as shown in the figure.

  The solid colored layer 13a is provided for the purpose of imparting designability over the entire decorative sheet (see FIGS. 1 and 2) and for the purpose of hiding the background of the first resin layer (see FIG. 2), and usually has no pattern. It is formed as a whole solid colored layer. On the other hand, the pattern colored layer 13b has a desired pattern or color depending on figures, characters, symbols, colors, combinations thereof, and the like, and has a planar shape, an uneven shape, and a convex shape on the surface side of the solid colored layer 13a (see FIG. 1 and 2). In addition, the pattern coloring layer 13b may also serve as the solid coloring layer 13a, and the coloring layer 13 may be composed of only the solid coloring layer 13a or only the pattern coloring layer 13b.

  In the decorative sheet of the present invention, as shown in FIG. 1, the colored layer 13 is composed of a solid colored layer 13a and a pattern colored layer 13b, and the first resin layer 11 is provided with the pattern colored layer 13b. The solid colored layer 13a may be formed so as to cover it. On the other hand, as shown in FIG. 2, after the solid colored layer 13 a is formed on the first resin layer 11, the pattern colored layer 13 b may be formed.

  Such a colored layer 13 is formed of a coating agent for the colored layer 13 which is mainly composed of a binder resin and includes a solvent and other additives. A water-based coating agent using water or / and a water-soluble organic solvent as a solvent, or a solvent-based coating agent using a water-insoluble organic solvent or the like as a solvent can be used.

  When the colored layer 13 is formed by the water-based coating agent, the organic solvent does not bleed out from the decorative sheet over time. For example, even if the decorative sheet is used for an interior material of a building such as a house, it is oozed. The organic solvent is preferably used because it is released into the room and there is no fear of adversely affecting the human body.

  Examples of binder resins for aqueous coating agents include (meth) acrylic monomers such as acrylic acid esters, methacrylic acid esters, hydroxyethyl acrylate, and hydroxyethyl methacrylate, nitrile monomers such as acrylonitrile and methacrylonitrile, acrylamide, and methacrylic acid. Amide monomers such as amides, N-alkoxy substituted and N-methylol substituted amide monomers, styrene monomers such as styrene, vinyltoluene, α-methylstyrene, divinylbenzene, diallyl phthalate, allyl glycidyl ether , One or more of allyl monomers such as triallyl isocyanurate, monomers having a polymerizable double bond such as vinyl acetate and N-vinylpyrrolidone, and acrylic acid having a carboxyl group, Use an alkali solution soluble (meth) acrylic copolymer consisting of a copolymer with one or more unsaturated carboxylic acids such as tacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, etc. Can do.

  Other binder resins for aqueous coating agents include, for example, polyarrylamide resins, poly (meth) acrylic acid resins, polyethylene oxide resins, poly N-vinylpyrrolidone resins, water-soluble polyurethane resins ( Two-component curable polyurethane resins), water-soluble polyester resins, water-soluble polyamide resins, water-soluble amino resins, water-soluble phenol resins, and other water-soluble synthetic resins, polynucleotides, polypeptides, polysaccharides, Water-soluble natural polymers such as, etc., etc. can also be used.

  Examples of other binder resins for aqueous coating agents include natural rubber, synthetic rubber, polyvinyl acetate resin, (meth) acrylic resin, polyvinyl chloride resin, polyurethane resin, and polyurethane-polyacrylic. Resin-modified or mixed resins, and other resins can be used. One or more of the above resins are used.

  Furthermore, as a binder resin for an aqueous coating agent, urethane resins such as acrylic-modified urethane resins, polyester-modified urethane resins, vinyl chloride-vinyl acetate copolymer-modified urethane resins, polyol resins, or vinyl chloride-acetic acid. A mixed resin of a vinyl copolymer and an acrylic resin or the like can be used.

  The binder resin for the aqueous coating agent is made aqueous by dissolution, emulsification, microencapsulation, or other methods, and used for the aqueous coating agent.

  As a solvent for the aqueous coating agent, water-soluble organic solvents such as water and alcohol can be used. As the water, ordinary industrial water can be used. Further, as a water-soluble organic solvent composed of water and alcohol, it can be prepared using water, lower alcohols such as methanol, ethanol, isopropyl alcohol and N-propyl alcohol, glycols and esters thereof, and the like. .

  By using such lower alcohols, glycols and esters thereof as a solvent, it is possible to improve so-called printing characteristics such as improvement of ink fluidity and improvement of wetting of the first resin layer as a printing medium. it can. However, on the other hand, if such a solvent remains in a certain amount or more in the decorative sheet, when the decorative sheet is used in a vacuum forming method or the like, the solvent is vaporized by heat, causing a problem in the design properties of the entire decorative sheet. In the present invention, the residual amount of the solvent is limited. This feature point will be described later.

  Next, the solvent-based coating agent will be described. Binder resins for solvent-based coating agents include chlorinated polyolefin resins such as chlorinated polyethylene and chlorinated polypropylene, polyester resins, polyurethane resins, acrylic resins, vinyl acetate resins, vinyl chloride / vinyl acetate copolymers, and cellulose resins. Etc., and one or more of these may be used in combination.

  The solvent of the solvent-based coating agent is not particularly limited, and examples thereof include non-toxic solvents such as toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether. A water-soluble organic solvent or a mixed solvent thereof is used.

  Even in such a solvent, as in the case of the water-based coating agent, it is effective in improving so-called printing characteristics, but when it exceeds a certain amount in the decorative sheet, there is a problem in design properties. Therefore, in the present invention, the residual of the solvent is limited. This feature point will be described later.

  Additives are commonly used for water-based and solvent-based coating agents. Examples of the additive include pigments and other pigments (also referred to as colorants or colored pigments), waxes, dispersants, antifoaming agents, leveling agents, stabilizers, fillers, lubricants, lubricants, and the like.

  As the coloring pigment, a commonly used organic or inorganic pigment can be used. As the yellow pigment, azo pigments such as monoazo, disazo and polyazo, organic pigments such as isoindolinone, and 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, 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. As the 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.

  In the case of using a solvent, the coating agent for the colored layer 13 contains a resin composition (binder resin) and, if necessary, other additives in the solvent, and is dissolved, dispersed, and mixed by a known method. Prepared.

  The colored layer 13 is formed by applying a coating agent for the colored layer 13 by coating or printing, and then drying and curing. Among these, the solid colored layer 13a is provided by coating or printing, and the pattern colored layer 13b is usually provided by printing. When applying the coating agent for the colored layer 13, 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 Methods such as coating, comma coating, spray coating, pouring coating, and brush coating can be used. Moreover, when printing the coating agent for the colored layer 13, relief printing such as gravure, letterpress and flexo, planographic printing such as planographic offset and dilithographic printing, stencil printing such as silk screen, electrostatic printing, ink jet printing, Various known methods such as transfer printing from a transfer sheet, and other hand-drawn methods can be used.

(adhesive)
Next, the adhesive (layer) 14 will be described.

  The adhesive (layer) 14 is an indispensable layer for forming the decorative sheet 10 by bonding the first resin layer 11 on which the colored layer 13 described above is formed and the second resin layer 12 described later. The adhesive (layer) 14 has a role as a primer layer or an anchor layer that improves the adhesion between the colored layer 13 formed on the first resin layer 11 and the second resin layer, There is an effect of improving the long-term appearance maintenance. Such an action can hold the formed pattern for a long time and is extremely effective.

  The adhesive (layer) 14 is composed of a resin composition, a solvent, and other additives. The solvent is not particularly limited, and examples thereof include water-insoluble organic solvents such as toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methanol, ethanol, isopropyl alcohol, A water-soluble organic solvent such as normal propyl alcohol, water, or a mixed solvent thereof can be used.

  Examples of the resin composition include rubber resins, acrylic resins, epoxy resins, urethane resins, and the like. Of these, urethane resins are preferably used. By using a urethane-based resin, a stronger adhesive strength can be obtained, and a decorative sheet excellent in flexibility can be provided.

  The urethane-based resin is a polyurethane having a polyol (polyhydric alcohol) as a main component and an isocyanate as a crosslinking agent (curing agent).

  The polyol has two or more hydroxyl groups in the molecule. Examples of the polyol include polyethylene glycol, polypropylene glycol, butylene glycol, neopentyl glycol, 1,6-hexanediol, acrylic polyol, polyester polyol, polyether polyol, and the like.

  As the isocyanate, those usually used in the production of polyurethane are also used in the present invention. Examples of the isocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, lysine ester triisocyanate, 1,4,8-triisocyanate octane, 1,3,6-triisocyanate hexane, 2,5 Aliphatic polyisocyanates such as 1,7-trimethyl-1,8-diisocyanate-5-isocyanate methyloctane, 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanate methyl-3 , 5,5-trimethylcyclohexyl isocyanate (common name: isophorone diisocyanate), 1,3,5-triisocyanate cyclohexane, , 3,5-trimethylisocyanatocyclohexane, 2- (3-isocyanatopropyl) -2,5-di (isocyanatomethyl) -bicyclo (2,2,1) heptane, etc., 1,3- or Aro-aliphatic polyisocyanates such as 1,4-xylylene diisocyanate or mixtures thereof, 1,3- or 1,4-bis (1-isocyanate-1-methylethyl) benzene, 1,3,5-triisocyanate methylbenzene , M-phenylene diisocyanate, p-phenylene diisocyanate, triphenylmethane-4,4 ′, 4 ″ monotriisocyanate, 4,4′monodiphenylmethane-2,2 ′, 5,5′-tetraisocyanate, etc. Isocyanates and derivatives of these polyisocyanates These polyisocyanates may be used in combination of two or more of these, including aliphatic polyisocyanates, alicyclic polyisocyanates and araliphatic polyisocyanates, and their polyisocyanate derivatives. These polyisocyanates are excellent in safety, hygiene and weather resistance.

  In the case of using a solvent, the adhesive is prepared by dissolving, dispersing, and mixing the resin composition and, if necessary, other additives in the solvent, and using a known method.

  The adhesive is formed by coating the surface of the colored layer 13 on the first resin layer 11 and drying and curing it. As the coating method, various known methods such as roll coating, gravure coating, air knife coating, comma coating and the like are used. From the viewpoint of productivity, gravure coating and comma coating are preferably used.

(Colored layer and adhesive thickness and residual solvent)
In the colored layer 13 and the adhesive (layer) 14 in the decorative sheet 10 of the present invention described above, the sum of the thicknesses is 5 to 30 μm, and the sum of the amount of the solvent remaining in each of these layers is It is characterized by being 10 to 80 mg / m ² . As described above, a solvent is used for each of these layers, and the balance between the merits of the solvent (prevention of printing characteristics and air bleeding (biting)) and the demerits (disruption of the design due to vaporization) is adjusted. Therefore, it is preferable to set each of the above parameters within such a range.

  If the sum of the thicknesses of the respective layers is less than 5 μm, the colored layer 13 is also thinned accordingly, so that a desired design may not be reproduced, and when the adhesive (layer) 14 is thinned, Adhesive strength between layers constituting the sheet is impaired, causing delamination. On the other hand, if the sum of the thicknesses of the respective layers is larger than 30 μm, the amount of the solvent used in each of these layers increases, and the amount of the remaining solvent increases accordingly, and the disadvantage of the solvent increases. Because it will end up.

  Here, in the decorative sheet 10 of the present invention, only the sum of each layer is limited, and the thickness of each layer (colored layer 13 and adhesive (layer) 14) alone is not particularly limited. The sum of the respective layers may be within a predetermined range. For example, the ratio of the thickness of the colored layer 13 to the adhesive (layer) 14 is the thickness of the colored layer / the thickness of the adhesive = 1/10. It is preferable to set to ~ 3/1. If the ratio is less than 1/10, the thickness of the colored layer may be too thin and it may be difficult to express a desired design. On the other hand, if the ratio is greater than 3/1, the adhesive This is because there is a case where it is difficult to smooth the unevenness on the surface of the colored layer by the adhesive, which may cause air smearing (biting).

Further, if the sum of the amount of the solvent remaining in each layer is less than 10 mg / m ² , the merit of the solvent, that is, the printing characteristics and the prevention of air bleeding (biting) cannot be effectively exhibited, and coloring The formation yield of the layer 13 may be reduced or air spots may occur frequently. On the other hand, if the sum of the amount of the solvent remaining in each layer is more than 80 mg / m ² , the disadvantage due to the solvent, that is, There may be a problem that the designability is lowered by the vaporization of the solvent.

  Here, in the present invention, the “amount of remaining solvent” means the amount of the solvent remaining in each layer in a state where each layer is formed by printing or the like and then dried to form a final decorative sheet. To do. The amount of the residual solvent in the present invention is prepared by preparing a 5 cm × 10 cm decorative sheet as a sample, cutting it into 0.5 cm × 2.5 cm strips, and putting it in a sample bottle to perform gas chromatography. It is the value which measured the quantity of the solvent which remains in the said sample by (made by Shimadzu Corporation).

(Second resin layer)
Next, the second resin layer 12 will be described.

  The second resin layer 12 is also an essential layer for the decorative sheet 10 of the present invention, like the first resin layer 11.

  As shown in FIG. 1, when the 1st resin layer 11 is arrange | positioned on the surface side of the decorative sheet 10, the said 2nd resin layer 12 will be located in the side which contact | connects the processed material to which a decorative sheet is adhered, In some cases, it functions as a so-called backer layer. On the other hand, as shown in FIG. 2, when the first resin layer 11 is disposed on the back side of the decorative sheet 10, the second resin layer 12 is located on the front side of the decorative sheet. It will function as a so-called surface protection wound. Accordingly, when it functions as a so-called backer layer as shown in FIG. 1, it is preferably colored and opaque, while it is transparent when it functions as a so-called surface protective layer as shown in FIG. It is preferable.

  The material and the like of the second resin layer 12 can be the same as those of the first resin layer 11 described above, and can be appropriately selected from the above description.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1
As a decorative sheet of Example 1 of the present invention, a decorative sheet having a layer structure as shown in FIG. 1 was prepared. Specifically, it is as follows.

  As the first resin layer, an acrylic resin sheet having a thickness of 125 μm was used. As the second resin layer, an ABS resin sheet having a thickness of 400 μm was used.

  A colored layer composed of a solid colored layer and a pattern colored layer was formed on the first resin layer. In forming this colored layer, a solvent-based coating agent containing methyl ethyl ketone, ethyl acetate, and methyl isobutyl ketone as a solvent was used.

  As an adhesive for adhering the first resin layer and the second resin layer on which the colored layer is formed, a two-component curable urethane resin containing ethyl acetate as a solvent was used.

The sum of the thickness of the colored layer and the thickness of the adhesive in the decorative sheet of Example 1 of the present invention is 10 μm, and the amount of the solvent remaining in the colored layer and the adhesive of the decorative sheet is 20 mg / It was m ^2. The amount of the remaining solvent was measured using gas chromatography by the method described above.

  For such a decorative sheet of Example 1 of the present invention, (1) printing characteristics of the colored layer, (2) interlaminar strength, (3) air smear when bonded, and (4) vacuum forming method and injection molding Each of the design properties after simultaneous decoration using the method was tested.

  Here, (1) the printing characteristics of the colored layer means the printing characteristics at the stage of forming the decorative sheet of Example 1, that is, the stage of forming the colored layer on the first resin layer. In this case, gravure printing and coating were performed, and the presence or absence of unevenness, streaks, and pinhole missing during print coating was confirmed by visual observation. In addition, as a blocking evaluation at the time of rewinding, the gloss change of the printed surface was also confirmed visually.

  (2) Interlaminar strength is determined by leaving the decorative sheet of Example 1 at 40 ° C. for 3 days, and then peeling the first resin layer and the second resin layer in the 180 ° direction using a tensile tester. It was measured.

  Furthermore, (3) air fringing when bonding is the step of forming the decorative sheet of Example 1, that is, when bonding the first resin layer on which the colored layer is formed and the second resin layer. Specifically, the second resin layer is forcibly peeled immediately after application of the adhesive, and the peeled surface is observed with a loupe or with the naked eye. It went by. In this case, when air stagnation (biting) has occurred, a recess as a trace of air stagnation (biting) is observed on the surface of the second resin layer.

  Moreover, (4) The design property after the simultaneous decoration using the vacuum forming method and the injection molding method refers to the vacuum forming method and the injection molding method using the decorative sheet after the decorative sheet of Example 1 is formed. It is a test of how the design properties of the decorative sheet have changed at the same time, and specifically, the decorative sheet is heated to 170 ° C. using a heater, and then predetermined by a vacuum forming method. The shape was formed, and this was mounted on an injection mold and injection molding was performed. The appearance of the finished formed product was observed with the naked eye. In addition, the shape of the metal mold | die used in performing the vacuum forming method used what showed the R (roundness) of radius 10mm in the corner | angular shape which showed the substantially rectangular parallelepiped top.

  Table 1 below shows the main parameters of the decorative sheet of Example 1 and the evaluation results of the above (1) to (4).

(Examples 2 to 4 and Comparative Examples 1 to 3)
In the same manner as the decorative sheet of Example 1, the decorative sheets of Examples 2 to 4 of the present invention and the decorative sheets of Comparative Examples 1 to 3 are prepared, and the same evaluation as the decorative sheet of Example 1 is performed. went. The main parameters in each example and comparative example, and the evaluation results of the above (1) to (4) are shown in Table 1 which is the same as that of the decorative sheet of Example 1. In addition, about parameters etc. which are not in Table 1, all are the same as the decorative sheet of Example 1.

上記実施例と比較例とを対比すれば明らかなように、本発明の化粧シートは、印刷特性が良好であり、形成時にエアがみが生じることがなく、また形成後にあっては層間強度が良好であり、さらに真空成形法および射出成形法の同時加飾において用いも意匠性に問題が生じることがない、優れた化粧シートであることが分かった。

As is clear from the comparison between the above examples and comparative examples, the decorative sheet of the present invention has good printing characteristics, no air smears during formation, and the interlayer strength after formation. It was found to be an excellent decorative sheet that is good and has no problem in design even when used in the simultaneous decorating of the vacuum molding method and the injection molding method.

It is a schematic sectional drawing which shows the structure of an example of the decorative sheet of this invention. It is a schematic sectional drawing which shows the structure of another example of the decorative sheet of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Decorative sheet 11 ... 1st resin layer 12 ... 2nd resin layer 13 ... Colored layer 14 ... Adhesive

Claims (3)

The first resin layer and the second resin layer are bonded so as to have a first resin layer formed with a colored layer and a second resin layer, and sandwich the colored layer formed on the first resin layer. A decorative sheet bonded with an agent,
The sum of the thickness of the colored layer formed on the first resin layer and the thickness of the adhesive is 5 to 30 μm,
The decorative sheet is characterized in that the sum of the amount of the solvent remaining in the colored layer and the amount of the solvent remaining in the adhesive is 10 to 80 mg / m ² . The first resin layer and the second resin layer are bonded so as to have a first resin layer formed with a colored layer and a second resin layer, and sandwich the colored layer formed on the first resin layer. A decorative sheet bonded with an agent,
The sum of the thickness of the colored layer formed on the first resin layer and the thickness of the adhesive is 5 to 30 μm,
The decorative sheet is characterized in that the sum of the amount of the solvent remaining in the colored layer and the amount of the solvent remaining in the adhesive is 10 to 65 mg / m ² . The decorative sheet according to claim 1, wherein the decorative sheet is used in a vacuum molded product or an injection molded product .

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