JP2020049945A - Decorative sheet and decorative resin molding - Google Patents

Abstract

To provide a decorative sheet having an uneven shape on an outer surface thereof, suitably maintaining the uneven shape even at molding, while having excellent chemical resistance.SOLUTION: A decorative sheet includes an uneven shape on an outer surface thereof. The decorative sheet at least includes a first protective layer 1 composing the uneven shape and a second protective layer 2, from an outer side. The first protective layer is formed with a cured product of a resin composition containing an ionization radiation-curable resin and a thermoplastic resin. The second protective layer is formed with a cured product of an ionization radiation-curable resin composition containing a polycarbonate(meth)acrylate.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a decorative sheet and a decorative resin molded product having an uneven shape and having both excellent moldability and chemical resistance.

  2. Description of the Related Art A decorative resin molded product obtained by laminating a decorative sheet on the surface of a resin molded product is used for a vehicle interior component, a building material interior material, a home appliance housing, and the like. As a method for molding such a decorative resin molded product, a decorative sheet is previously formed into a three-dimensional shape by a vacuum forming die, the molded sheet is inserted into an injection molding die, and the resin in a fluid state is placed in the die. An insert molding method for injecting a resin and a molded sheet into one piece (for example, see Patent Document 1), a decorative sheet inserted in a mold at the time of injection molding, and a molten resin injected and injected into a cavity. An injection molding simultaneous decorating method of integrating and decorating the surface of a resin molded body (for example, see Patent Literature 2 and Patent Literature 3) is known.

  In recent years, with the diversification of consumer needs, decorative resin molded products having various design properties have been demanded. In order to meet such diversifying consumer needs, there is a demand for the development of a decorative resin molded product having a design feeling, a touch feeling, and the like based on the unevenness of the surface.

  For the production of a decorative resin molded product having an uneven surface, for example, a decorative sheet having an uneven surface formed in advance is used. However, when manufacturing a decorative resin molded product using a decorative sheet having an uneven shape, the uneven shape is deformed by heat or pressure when the decorative sheet is subjected to injection molding or preliminary forming (vacuum forming) prior thereto. There is a problem that it is difficult to maintain the uneven shape, such as disappearing.

JP 2004-322501 A Japanese Patent Publication No. 50-19132 JP-B-61-17255

  As described above, in recent years, the development of a decorative resin molded product having a design feeling based on the unevenness of the surface, a feeling of touch, and the like has been desired, but a decorative resin molded product using a decorative sheet having the uneven shape has been demanded. In the case of manufacturing, when the decorative sheet is subjected to injection molding or preliminary molding (vacuum molding) prior thereto, there is a problem that it is difficult to maintain the uneven shape, such as deformation or disappearance of the uneven shape due to heat or pressure.

  In recent years, decorative sheets used in the production of decorative resin molded articles have a function of imparting stain resistance to various products used in daily life to the decorative resin molded articles in addition to moldability. Is required. In particular, in recent years, skin care products such as sunscreen cosmetics, chemicals containing alcohol, and the like tend to be frequently used, and the skin coated with such skin care products or the like comes into contact with a decorative resin molded product or contains alcohol. The frequency of chemicals adhering to decorative resin moldings is increasing, and decorative sheets are required to have even better chemical resistance to chemicals with high surface erosion to resin. .

  Under such circumstances, the present invention provides a decorative sheet having an uneven shape on the outer surface, in which the uneven shape is suitably maintained even by molding, and having excellent chemical resistance. Its main purpose is to: Further, another object of the present invention is to provide a decorative resin molded product using the decorative sheet, and a method for producing the same.

  The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, in the decorative sheet having an irregular shape on the outer surface, at least a first protective layer and a second protective layer that constitute the irregular shape are provided in order from the outside, and further, the first protective layer is The second protective layer is formed from a cured product of a resin composition containing an ionizing radiation-curable resin and a thermoplastic resin, and the second protective layer is formed from a cured product of an ionizing radiation-curable resin composition containing polycarbonate (meth) acrylate. As a result, it has been found that the concavo-convex shape is suitably maintained even by molding, and that excellent chemical resistance is exhibited. The present invention has been completed by further study based on such knowledge.

That is, the present invention provides the following aspects of the invention.
Item 1. A decorative sheet having an uneven shape on the outer surface,
In order from the outside, at least, a first protective layer constituting the uneven shape, and a second protective layer,
The first protective layer is formed of a cured product of a resin composition containing an ionizing radiation-curable resin and a thermoplastic resin,
The decorative sheet, wherein the second protective layer is formed of a cured product of an ionizing radiation-curable resin composition containing polycarbonate (meth) acrylate.
Item 2. Item 4. The decorative sheet according to Item 1, wherein in the first protective layer, the resin composition contains an ionizing radiation-curable resin and a thermoplastic resin in a mass ratio of 10:90 to 25:75.
Item 3. Item 3. The decorative sheet according to Item 1 or 2, wherein in the first protective layer, the weight average molecular weight of the thermoplastic resin is in a range of 90,000 to 150,000.
Item 4. Item 4. The decorative sheet according to any one of Items 1 to 3, wherein in the first protective layer, the number of functional groups of a monomer contained in the ionizing radiation-curable resin is in a range of 2 to 6.
Item 5. Item 5. The decorative sheet according to any one of Items 1 to 4, wherein in the first protective layer, the molecular weight of a monomer contained in the ionizing radiation-curable resin is in a range of 200 to 2,000. Item 6. Item 6. The decorative sheet according to any one of Items 1 to 5, wherein a base material layer is laminated on a surface of the second protective layer opposite to the first protective layer.
Item 7. Item 7. The decorative sheet according to any one of Items 1 to 6, wherein a primer layer is laminated on a surface of the second protective layer opposite to the first protective layer.
Item 8. Item 7. The decorative sheet according to any one of Items 1 to 7, wherein an arithmetic average roughness Ra of the outer surface is 0.1 μm or more and 100 μm or less.
Item 9. Item 10. The decorative sheet according to any one of Items 1 to 8, which is used in an insert molding method or an injection molding simultaneous decoration method.
Item 10. A decorative resin molded article having an uneven shape on the outer surface,
In order from the outside, at least, a first protective layer constituting the uneven shape, a second protective layer, and a molding resin layer,
The first protective layer is formed of a cured product of a resin composition containing an ionizing radiation-curable resin and a thermoplastic resin,
The decorative resin molded article, wherein the second protective layer is formed of a cured product of an ionizing radiation-curable resin composition containing polycarbonate (meth) acrylate.
Item 11. Item 10. Manufacture of a decorative resin molded article, comprising a step of injecting a resin to laminate a molded resin layer on a surface of the decorative sheet according to any one of Items 1 to 9 opposite to the surface having the uneven shape. Method.

  ADVANTAGE OF THE INVENTION According to this invention, in the decorative sheet provided with the uneven | corrugated shape on the outer surface, the said uneven | corrugated shape is suitably maintained also by shaping | molding, and the decorative sheet provided with excellent chemical resistance can be provided. Further, according to the present invention, it is also possible to provide a decorative resin molded product using the decorative sheet, and a method for producing the same.

It is a schematic diagram of the cross-sectional structure of one form of the decorative sheet of the present invention. It is a schematic diagram of the cross-sectional structure of one form of the decorative sheet of the present invention. It is a schematic diagram of the cross-sectional structure of one form of the decorative resin molded product of the present invention.

1. Decorative sheet The decorative sheet of the present invention is a decorative sheet having an uneven shape on the outer surface, and at least a first protective layer and the second protective layer constituting the uneven shape in order from the outside. Wherein the first protective layer is formed of a cured product of a resin composition containing an ionizing radiation-curable resin and a thermoplastic resin, and the second protective layer contains polycarbonate (meth) acrylate And a cured product of the ionizing radiation-curable resin composition. Since the decorative sheet of the present invention has such a specific configuration, the concave-convex shape can be suitably maintained even by molding, and excellent chemical resistance can be exhibited.

  Hereinafter, the decorative sheet of the present invention will be described in detail. In this specification, the numerical range indicated by “to” means “over” and “below”, except where explicitly described as “over” and “below”. For example, the notation of 2 to 15 mm means 2 mm or more and 15 mm or less. In this specification, “(meth) acrylate” means “acrylate or methacrylate”, and other similar substances have the same meaning. Further, the decorative sheet of the present invention does not have to have a pattern layer or the like, and may be, for example, transparent.

Laminated structure of decorative sheet The decorative sheet of the present invention has an uneven surface on the outer surface, and at least a first protective layer and a second protective layer constituting the uneven shape in order from the outside. Are laminated.

  In the decorative sheet of the present invention, the base layer 3 is provided on the surface of the second protective layer opposite to the first protective layer for the purpose of enhancing the shape retention of the decorative sheet. Is also good. Immediately below the surface of the second protective layer on the side opposite to the first protective layer, the adhesion between the second protective layer and the layer located thereunder (eg, the base layer 3, the picture layer 5, etc.) The primer layer 4 may be provided as needed in order to improve the performance.

  On the surface of the second protective layer opposite to the first protective layer, a picture layer 5 may be provided as necessary for the purpose of providing decorativeness. For example, when the base layer 3 and the primer layer 4 are provided, the picture layer 5 may be provided between the base layer 3 and the primer layer 4.

  Further, a shielding layer (not shown) may be provided between the base layer 3 and the second protective layer 2 as needed for the purpose of suppressing a change or variation in color of the base layer 3. Good. For example, when the primer layer 4 is provided, the concealing layer may be provided between the base material layer 3 and the primer layer 4, and when the picture layer 5 is provided, the concealing layer is It may be provided between the material layer 3 and the picture layer 5.

  Further, a transparent resin layer (not shown) may be provided on the surface of the second protective layer opposite to the first protective layer, if necessary, for the purpose of improving abrasion resistance (scratch resistance). Good. For example, when the primer layer 4 and the pattern layer 5 are provided, the transparent resin layer may be provided between the pattern layer 5 and the primer layer 4.

  Furthermore, in the decorative sheet of the present invention, the back surface of the decorative sheet (the surface opposite to the first protective layer 1) is provided for the purpose of enhancing the adhesion with the molding resin during the formation of the decorative sheet. May be provided with a back surface adhesive layer (not shown) as necessary.

  As an example of the laminated structure of the decorative sheet of the present invention, a laminated structure in which a second protective layer / first protective layer is laminated; a laminated structure in which a base layer 3 / second protective layer / first protective layer is laminated; A laminated structure in which base layer 3 / primer layer 4 / second protective layer / first protective layer is sequentially laminated; a laminated structure in which substrate layer 3 / picture layer 5 / second protective layer / first protective layer are sequentially laminated. Structure; laminated structure in which base layer 3 / pattern layer 5 / primer layer 4 / second protective layer / first protective layer are sequentially laminated; base layer 3 / pattern layer 5 / transparent resin layer / primer layer 4 / first layer A laminated structure in which two protective layers / first protective layers are sequentially laminated is exemplified.

  FIG. 1 is a cross-sectional view of a decorative sheet in which a base material layer 3 / second protective layer / first protective layer is laminated as one embodiment of the decorative sheet laminated structure of the present invention. FIG. 2 shows, as an embodiment of the laminated structure of the decorative sheet of the present invention, a cross section of a decorative sheet in which a base layer 3 / a pattern layer 5 / a primer layer 4 / a second protective layer / a first protective layer are sequentially laminated. The figure is shown.

Composition of each layer of the decorative sheet [base layer 3]
The base material layer 3 is a resin sheet (resin film) that functions as a support in the decorative sheet of the present invention. The resin component used for the base layer 3 is not particularly limited, and may be appropriately selected according to three-dimensional moldability, compatibility with the molding resin, and the like. Preferably, a resin film made of a thermoplastic resin is used. No. As the thermoplastic resin, specifically, acrylonitrile-butadiene-styrene resin (hereinafter sometimes referred to as “ABS resin”), acrylonitrile-styrene-acrylate resin (hereinafter referred to as “ASA resin”) Acrylonitrile-ethylene-propylene-diene-styrene resin, acrylic resin, polypropylene, polyolefin resin such as polyethylene, polycarbonate resin, vinyl chloride resin, polyethylene terephthalate (PET), and the like. Among them, ABS resin and acrylic resin are preferable from the viewpoint of three-dimensional moldability. Further, the base material layer 3 may be formed of a single-layer sheet of these resins, or may be formed of a multi-layer sheet of the same or different resins.

  The flexural modulus of the base material layer 3 is not particularly limited. For example, when integrating the decorative sheet of the present invention with the molding resin by insert molding, the bending elastic modulus at 25 ° C. of the base layer 3 in the decorative sheet of the present invention is 500 to 4,000 MPa, preferably, 750 to 3,000 MPa. Here, the flexural modulus at 25 ° C. is a value measured according to JIS K7171. When the flexural modulus at 25 ° C. is 500 MPa or more, the decorative sheet has sufficient rigidity, and even when subjected to the insert molding method, the surface properties and moldability are further improved. Further, when the flexural modulus at 25 ° C. is 3,000 MPa or less, sufficient tension can be applied in the case of roll-to-roll production, and sag does not easily occur. And the so-called pattern registration becomes good.

  The base material layer 3 is subjected to a physical or chemical surface treatment such as an oxidation method or a concavo-convexity method on one or both surfaces thereof, if necessary, in order to improve the adhesion with a layer provided thereon. You may. Examples of the oxidation method performed as the surface treatment of the base material layer 3 include a corona discharge treatment, a chromium oxidation treatment, a flame treatment, a hot air treatment, and an ozone ultraviolet treatment. In addition, examples of the method of forming the surface unevenness performed as the surface treatment of the base material layer 3 include a sand blast method and a solvent treatment method. These surface treatments are appropriately selected according to the type of the resin component constituting the base material layer 3, and preferably include a corona discharge treatment method from the viewpoint of effects and operability.

  The base material layer 3 may be subjected to a treatment such as forming a known adhesive layer.

  Further, the base material layer 3 may be colored using a coloring agent, or may not be colored. Further, the base material layer 3 may be any one of colorless and transparent, colored and transparent, and translucent. The colorant used for the base material layer 3 is not particularly limited, but preferably includes a colorant that does not change color even at a temperature of 150 ° C. or more, and specifically includes existing dry colors, paste colors, and masterbatch resins. And the like.

  The thickness of the base material layer 3 is appropriately set depending on the use of the decorative sheet, the molding method for integrating with the molding resin, and the like, and is usually about 25 to 1000 μm, or about 50 to 700 μm. More specifically, if the decorative sheet of the present invention is subjected to the insert molding method, the thickness of the base material layer 3 is usually about 50 to 1000 μm, preferably about 100 to 700 μm, and more preferably 100 to 500 μm. Degree. When the decorative sheet of the present invention is subjected to the simultaneous injection molding and decorating method, the thickness of the base material layer 3 is usually about 25 to 200 μm, preferably about 50 to 200 μm, and more preferably about 70 to 200 μm. Is mentioned.

[First protective layer 1]
The first protective layer 1 has an uneven shape on the outer surface of the decorative sheet. The first protective layer 1 is formed of a cured product of a resin composition containing an ionizing radiation curable resin and a thermoplastic resin. In the decorative sheet of the present invention, the first protective layer 1 having an uneven shape is formed from a cured product of a resin composition containing an ionizing radiation-curable resin and a thermoplastic resin, and further, a second protective layer described later. By having the protective layer 2, even after molding, the uneven shape before molding can be suitably maintained, and excellent chemical resistance can be exhibited. That is, in the decorative sheet of the present invention, by forming the first protective layer 1 and the second protective layer 2 in order from the outside with a cured product of a specific resin composition, it is possible to maintain the uneven shape and achieve excellent resistance. It is possible to achieve both chemical properties.

<Uneven shape>
The uneven shape on the outer surface of the decorative sheet of the present invention is the uneven shape of the first protective layer 1. The concavo-convex shape provided in the first protective layer 1 is not particularly limited, and may be appropriately set according to a sense of design to be provided. Examples of the concavo-convex shape include a hairline pattern, a grain pattern, a geometric pattern (dots, stripes, carbon, and the like). In addition, the second protective layer 2 described later does not have to have an uneven shape, but preferably has an uneven shape along the uneven shape of the first protective layer 1.

  Further, regarding the height of the projections, the width of the projections, the pitch between adjacent projections, the width of the depressions, and the like in the uneven shape of the first protective layer 1, the design feeling and the like to be imparted to the decorative resin molded product May be set appropriately according to the conditions.

  For example, the arithmetic average roughness (Ra) of the surface of the first protective layer 1 (that is, the outer surface of the decorative sheet) is usually 1 to 20 μm, preferably from 1 to 20 μm, from the viewpoint of giving an excellent design feeling due to the uneven shape. Is 5 to 20 μm, more preferably 10 to 20 μm.

  In the decorative sheet of the present invention, the uneven shape of the first protective layer 1 may be formed in at least a part of the region in order to give the decorative sheet a high texture due to the uneven shape. That is, in the decorative sheet of the present invention, the uneven shape of the outer surface may be formed in a part of the region or may be formed in the whole region.

  The concave and convex portions of the first protective layer 1 reach the second protective layer 2 located below the first protective layer 1 and further reach, for example, the primer layer 4, the picture layer 5, the base layer 3, and the like. It may be. From the viewpoint of effectively suppressing the disappearance and deformation of the uneven shape during the injection molding of the decorative sheet, it is preferable that the concave portion of the uneven shape reaches the base material layer 3.

<Composition>
The first protective layer 1 is formed of a cured product of a resin composition containing an ionizing radiation curable resin and a thermoplastic resin. The ratio between the ionizing radiation-curable resin and the thermoplastic resin in the first protective layer 1 is preferably in a mass ratio of ionizing radiation-curable resin: thermoplastic resin = 10: 90 to 25:75, and 15:15. The ratio is more preferably about 85 to 25:75, and further preferably about 20:80 to 25:75.

  The thermoplastic resin is not particularly limited, but is preferably an acrylic resin, an acrylic-modified polyolefin resin, a chlorinated polyolefin resin, a vinyl chloride-vinyl acetate copolymer, a thermoplastic urethane resin, a thermoplastic polyester resin, a polyamide resin, or a rubber. Base resin and the like. Among these, an acrylic resin is particularly preferable from the viewpoint of maintaining both the unevenness and the excellent chemical resistance.

  As the acrylic resin, a homopolymer of (meth) acrylate, a copolymer of two or more different (meth) acrylate monomers, or a copolymer of (meth) acrylate and another monomer is used. Specific examples include poly (methyl meth) acrylate, poly (meth) ethyl acrylate, poly (meth) acrylate, butyl poly (meth) acrylate, and methyl (meth) acrylate- (meth). Such as butyl acrylate copolymer, ethyl (meth) acrylate-butyl (meth) acrylate copolymer, ethylene-methyl (meth) acrylate copolymer, and styrene-methyl (meth) acrylate copolymer; A (meth) acrylic resin comprising a homo- or copolymer containing a (meth) acrylic acid ester is preferably used.

  The weight average molecular weight of the thermoplastic resin is not particularly limited, but is preferably about 90,000 to 150,000, and more preferably 100,000 to 140,000, from the viewpoint of maintaining both the uneven shape and excellent chemical resistance. Degree, more preferably about 110,000 to 130,000.

  The weight average molecular weight of the thermoplastic resin in the present specification is a value measured by gel permeation chromatography using polystyrene as a standard substance.

(Ionizing radiation curable resin)
The ionizing radiation-curable resin used for forming the first protective layer 1 refers to a resin that crosslinks and cures when irradiated with ionizing radiation. Here, the ionizing radiation means an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing or cross-linking a molecule, and is usually ultraviolet (UV) or electron beam (EB). , X-rays, γ-rays, and other charged particles such as α-rays, ion beams, and the like. Among ionizing radiation curable resins, electron beam curable resins are suitable for use in forming a surface layer because they can be solvent-free, do not require a photopolymerization initiator, and have stable curing properties. Is done.

  Specific examples of the ionizing radiation-curable resin used for forming the first protective layer include those obtained by appropriately mixing a prepolymer, an oligomer, and / or a monomer having a polymerizable unsaturated bond or an epoxy group in a molecule. No.

  As the oligomer used as the ionizing radiation-curable resin, a (meth) acrylate oligomer having a radically polymerizable unsaturated group in the molecule is preferable, and in particular, two or more polymerizable unsaturated bonds in the molecule (2 Polyfunctional (meth) acrylate oligomers having at least one functional group are preferred. Examples of the polyfunctional (meth) acrylate oligomer include polycarbonate (meth) acrylate, acrylic silicone (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, and polyether (meth) acrylate , Polybutadiene (meth) acrylate, silicone (meth) acrylate, silicone-modified urethane (meth) acrylate, oligomer having a cationically polymerizable functional group in the molecule (for example, novolak epoxy resin, bisphenol epoxy resin, aliphatic vinyl ether, aromatic Group vinyl ether, etc.). Here, the polycarbonate (meth) acrylate is not particularly limited as long as it has a carbonate bond in a polymer main chain and has a (meth) acrylate group in a terminal or a side chain. It can be obtained by esterification with acrylic acid. The polycarbonate (meth) acrylate may be, for example, urethane (meth) acrylate having a polycarbonate skeleton. The urethane (meth) acrylate having a polycarbonate skeleton is obtained, for example, by reacting a polycarbonate polyol, a polyvalent isocyanate compound, and hydroxy (meth) acrylate. Acrylic silicone (meth) acrylate can be obtained by radically copolymerizing a silicone macromonomer with a (meth) acrylate monomer. Urethane (meth) acrylate can be obtained, for example, by esterifying a polyurethane oligomer obtained by the reaction of a polyether polyol or polyester polyol with a polyisocyanate with (meth) acrylic acid. Epoxy (meth) acrylate can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a bisphenol-type epoxy resin or a novolak-type epoxy resin having a relatively low molecular weight and esterifying it. A carboxyl-modified epoxy (meth) acrylate obtained by partially modifying the epoxy (meth) acrylate with a dibasic carboxylic anhydride can also be used. Polyester (meth) acrylate is obtained, for example, by esterifying hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth) acrylic acid, or It can be obtained by esterifying a hydroxyl group at the terminal of an oligomer obtained by adding an alkylene oxide with (meth) acrylic acid. Polyether (meth) acrylate can be obtained by esterifying the hydroxyl group of polyether polyol with (meth) acrylic acid. Polybutadiene (meth) acrylate can be obtained by adding (meth) acrylic acid to a side chain of a polybutadiene oligomer. Silicone (meth) acrylate can be obtained by adding (meth) acrylic acid to the terminal or side chain of silicone having a polysiloxane bond in the main chain. The silicone-modified urethane (meth) acrylate is obtained, for example, by reacting a urethane prepolymer having an isocyanate group with a silicone compound having a silanol group together with hydroxy (meth) acrylate. These oligomers may be used alone or in combination of two or more.

  Further, as the monomer used as the ionizing radiation-curable resin, a (meth) acrylate monomer having a radically polymerizable unsaturated group in a molecule is preferable, and among them, a polyfunctional (meth) acrylate monomer is preferable. The polyfunctional (meth) acrylate monomer may be any (meth) acrylate monomer having two or more polymerizable unsaturated bonds in the molecule. As the polyfunctional (meth) acrylate monomer, specifically, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (Meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate hydroxypivalate, dicyclopentanyl di (meth) acrylate, caprolactone-modified dicyclopentenyl di (Meth) acrylate, ethylene oxide-modified phosphate di (meth) acrylate, allylated cyclohexyldi (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate Acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, ethylene oxide modified bisphenol A di (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (Meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide-modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (Meth) acrylate, ethylene oxide-modified dipentaerythritol hexa (meth) acrylate , Caprolactone-modified dipentaerythritol hexa (meth) acrylate. These monomers may be used alone or in a combination of two or more.

  Among these ionizing radiation-curable resins, the number of functional groups of the monomer contained in the ionizing radiation-curable resin is in the range of 2 to 6, from the viewpoint of maintaining both the uneven shape and excellent chemical resistance. More preferably, the number of functional groups is in the range of 2 to 4. The molecular weight of the monomer contained in the ionizing radiation-curable resin is preferably about 200 to 2000, more preferably about 200 to 1500, and further preferably about 200 to 1000.

  Further, among these monomers, dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate, and ethylene oxide-modified bisphenol A diamine (Meth) acrylate and the like are particularly preferred.

<Other additives>
The resin composition used to form the first protective layer 1 may contain various additives according to the desired physical properties of the first protective layer 1. Examples of the additive include a weather resistance improver such as an ultraviolet absorber and a light stabilizer, an abrasion resistance improver, a polymerization inhibitor, a crosslinking agent, an infrared absorber, an antistatic agent, an adhesion improver, and a leveling agent. , A thixotropy-imparting agent, a coupling agent, a plasticizer, an antifoaming agent, a filler, a solvent, a coloring agent, a wax and the like. These additives can be appropriately selected and used from those commonly used. In addition, a reactive ultraviolet absorber or light stabilizer having a polymerizable group such as a (meth) acryloyl group in the molecule can be used as the ultraviolet absorber or light stabilizer. In addition, by blending a wax, scratch resistance and abrasion resistance can be improved. The wax is preferably an olefin wax such as a polyethylene wax (PE wax). When compounding a wax, the compounding amount in the curable resin composition is preferably about 0.1 to 5% by mass, more preferably about 0.5 to 3% by mass.

  Further, the first protective layer 1 may include a matting agent. The matting agent is not particularly limited, and includes, for example, inorganic particles and synthetic resin particles.

  Preferred examples of the inorganic particles include silica, alumina, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, kaolin, and hydrophobically treated products thereof. These inorganic particles may be used alone or in a combination of two or more. Preferred examples of the synthetic resin particles include acrylic beads, urethane beads, nylon beads, silicone beads, silicone rubber beads, polycarbonate beads, polyolefin wax (polypropylene wax, polyethylene wax, a mixture thereof, and the like). These synthetic resin particles may be used alone or in a combination of two or more.

  The first protective layer 1 may contain any one of inorganic particles and synthetic resin particles, or may contain them in combination. The average particle size of the inorganic particles and the synthetic resin particles is preferably from 0.1 to 5 μm, more preferably from 1 to 5 μm, and still more preferably from 2 to 5 μm, from the viewpoint of improving design. The particle diameters of the inorganic particles and the synthetic resin particles were measured using a Shimadzu laser diffraction type particle size distribution analyzer SALD-2100-WJA1, using a compressed air to inject powder to be measured from a nozzle, Refers to a spray-type dry measurement method in which the dispersion is measured.

<Thickness of first protective layer 1>
The thickness of the first protective layer 1 after curing is not particularly limited, but is preferably set as the cured thickness of the first protective layer 1 from the viewpoint of maintaining both the uneven shape and excellent chemical resistance. Is 0.01 to 20 μm, more preferably 0.1 to 15 μm, and still more preferably 1 to 12 μm. In addition, the thickness of the first protective layer 1 means the thickness of the projection of the first protective layer 1.

<Formation of First Protective Layer 1>
The first protective layer 1 may be formed on the second protective layer 2 so that the cured product of the curable resin composition has an uneven shape, and the specific method is not particularly limited. . As a method of providing the first protective layer 1 with a concavo-convex shape, for example, a method of performing embossing is given. From the viewpoint of providing fine irregularities, a method of embossing is preferable (for example, a first method or a second method described later).

  As a preferred method of forming the first protective layer 1 having the uneven shape, the following first method and second method are specifically mentioned.

First method: a sheet including a base material layer 3 and the like is prepared, and after embossing is performed on the side of the sheet on which the first protective layer 1 and the second protective layer 2 are to be laminated, the second protective layer 2 is formed. A resin composition to be used is applied, and a resin composition to be used for forming the first protective layer 1 is further applied thereon, and these resin compositions are cured for each layer or two layers at the same time. Method.

Second method: a sheet having a base material layer 3 and the like is prepared, and a resin composition used to form the second protective layer 2 on the side of the sheet on which the first protective layer 1 and the second protective layer 2 are laminated. Is applied thereon, and a resin composition used for forming the first protective layer 1 is applied thereon, and after curing these resin compositions, embossing is performed on the first protective layer 1 side. Method.

  The method of applying the resin composition used to form the first protective layer 1 is not particularly limited. For example, in the case of the first method or the second method, a gravure coat, a bar coat, a roll coat, A reverse roll coat, a comma coat and the like can be mentioned, and a gravure coat is preferable.

  The resin composition (uncured resin layer) thus applied is irradiated with ionizing radiation such as an electron beam or ultraviolet light to cure the resin composition and form the first protective layer 1.

  Here, when an electron beam is used as the ionizing radiation, the acceleration voltage can be appropriately selected according to the resin used and the thickness of the layer, and the acceleration voltage is usually about 70 to 300 kV.

  In electron beam irradiation, the higher the acceleration voltage, the higher the transmission capacity. When simultaneously curing the first protective layer and the second protective layer 2, the acceleration voltage is set so that the penetration depth of the electron beam and the total thickness of the first protective layer 1 and the second protective layer 2 become substantially equal. It is preferable to select one. When a substrate (for example, a substrate layer or the like) provided on the surface of the second protective layer on the side opposite to the first protective layer is used, a substrate that is degraded by an electron beam is used. By selecting the accelerating voltage so that the total thickness of the first protective layer 1 and the second protective layer 2 becomes substantially equal, it is possible to suppress the irradiation of an extra electron beam to the lower layer, The deterioration of the lower layer can be minimized.

  The irradiation dose is preferably an amount at which the crosslinking density of the resin layer is saturated, and is usually selected in the range of 5 to 300 kGy (0.5 to 30 Mrad), preferably 10 to 50 kGy (1 to 5 Mrad).

  Further, the electron beam source is not particularly limited. For example, various electron beam accelerators such as Cockloft-Walton type, Van degraft type, resonance transformer type, insulating core transformer type, or linear type, dynamitron type, and high frequency type Can be used.

  When ultraviolet rays are used as ionizing radiation, light rays containing ultraviolet rays having a wavelength of 190 to 380 nm may be emitted. The ultraviolet light source is not particularly limited, and examples thereof include a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, and a carbon arc lamp.

[Second protective layer 2]
The second protective layer 2 is located below the first protective layer 1 (on the side opposite to the outside). The second protective layer is formed of a cured product of an ionizing radiation-curable resin composition containing polycarbonate (meth) acrylate. As described above, in the decorative sheet of the present invention, the first protective layer 1 forming the outer unevenness is a cured product of a resin composition containing an ionizing radiation-curable resin and a thermoplastic resin. Further, by forming the second protective layer 2 from a cured product of the ionizing radiation-curable resin composition containing polycarbonate (meth) acrylate, it is possible to suitably maintain both the unevenness and the excellent chemical resistance. It has become possible.

  The second protective layer 2 preferably has an uneven shape along the uneven shape of the first protective layer 1. The details of the uneven shape of the first protective layer 1 are as described above.

  As described above, the polycarbonate (meth) acrylate used for the second protective layer 2 has a carbonate bond in the polymer main chain and a (meth) acrylate group in a terminal or a side chain. For example, it can be obtained by esterifying a polycarbonate polyol with (meth) acrylic acid. This (meth) acrylate preferably has two or more functionalities from the viewpoint of crosslinking and curing. The polycarbonate (meth) acrylate may be, for example, urethane (meth) acrylate having a polycarbonate skeleton. The urethane (meth) acrylate having a polycarbonate skeleton is obtained, for example, by reacting a polycarbonate polyol, a polyvalent isocyanate compound, and hydroxy (meth) acrylate.

  The above-mentioned polycarbonate (meth) acrylate is obtained, for example, by converting a part or all of the hydroxyl groups of a polycarbonate polyol to (meth) acrylate (acrylate or methacrylate). This esterification reaction can be performed by a usual esterification reaction. For example, 1) a method of condensing a polycarbonate polyol and an acrylic acid halide or a methacrylic acid halide in the presence of a base, 2) a method of condensing a polycarbonate polyol with an acrylic acid anhydride or a methacrylic acid anhydride in the presence of a catalyst, Or 3) a method of condensing a polycarbonate polyol with acrylic acid or methacrylic acid in the presence of an acid catalyst.

The above polycarbonate polyol is a polymer having a carbonate bond in the polymer main chain and having two or more, preferably 2 to 50, more preferably 3 to 50 hydroxyl groups at the terminal or side chain. A typical production method of this polycarbonate polyol is a method of performing a polycondensation reaction from a diol compound (A), a trihydric or higher polyhydric alcohol (B), and a compound (C) to be a carbonyl component. Diol compound used as a raw material (A) is represented by the general formula HO-R ¹ -OH. Here, R ¹ is a divalent hydrocarbon group having 2 to 20 carbon atoms, and the group may contain an ether bond. For example, it is a linear or branched alkylene group, cyclohexylene group, or phenylene group.

  Specific examples of the diol compound include ethylene glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, polyethylene glycol, neopentyl glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5 pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,3-bis (2-hydroxyethoxy) benzene, 1,4-bis (2 -Hydroxyethoxy) benzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and the like. These diols may be used alone or in combination of two or more.

  Examples of the trihydric or higher polyhydric alcohol (B) include alcohols such as trimethylolpurpan, trimethylolethane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, glycerin, and sorbitol. Further, alcohols having hydroxyl groups obtained by adding 1 to 5 equivalents of ethylene oxide, propylene oxide, or other alkylene oxides to the hydroxyl groups of these polyhydric alcohols may be used. These polyhydric alcohols may be used alone or in combination of two or more.

  The compound (C) serving as the carbonyl component is any compound selected from diester carbonate, phosgene, and equivalents thereof. Specific examples thereof include diester carbonates such as dimethyl carbonate, diethyl carbonate, diisopropyl carbonate, diphenyl carbonate, ethylene carbonate and propylene carbonate, phosgene, and halogenated formate esters such as methyl chloroformate, ethyl chloroformate and phenyl chloroformate. And the like. These may be used alone or as a mixture of two or more.

  The polycarbonate polyol is synthesized by performing a polycondensation reaction of the diol compound (A), the trihydric or higher polyhydric alcohol (B), and the compound (C) serving as a carbonyl component under general conditions. . For example, the charging molar ratio of the diol compound (A) and the polyhydric alcohol (B) is preferably in the range of 50:50 to 99: 1, and the diol compound of the compound (C) serving as a carbonyl component ( The charged molar ratio of A) to the polyhydric alcohol (B) is preferably 0.2 to 2 based on the hydroxyl groups of the diol compound and the polyhydric alcohol.

  The equivalent number of hydroxyl groups (eq./mol) present in the polycarbonate polyol after the polycondensation reaction at the above charged ratio is 3 or more, preferably 3 to 50, more preferably 3 to 3 on average per molecule. 20. Within this range, a necessary amount of (meth) acrylate groups will be formed by the esterification reaction described below, and the polycarbonate (meth) acrylate resin will have appropriate flexibility. The terminal functional group of the polycarbonate polyol is usually an OH group, but a part thereof may be a carbonate group.

  The method for producing a polycarbonate polyol described above is described in, for example, JP-A-64-1726. Further, as described in JP-A-3-181517, this polycarbonate polyol can also be produced by a transesterification reaction between a polycarbonate diol and a trihydric or higher polyhydric alcohol.

  The molecular weight of the polycarbonate (meth) acrylate used in the present invention is measured by gel permeation chromatography (GPC), and the weight average molecular weight in terms of standard polystyrene is preferably 500 or more. More preferably, it is more preferably 2,000 or more. The upper limit of the weight average molecular weight of the polycarbonate (meth) acrylate is not particularly limited, but is preferably 100,000 or less, more preferably 50,000 or less, from the viewpoint of controlling the viscosity so as not to be too high. Since the maintenance of the concavo-convex shape of the decorative sheet of the present invention and the excellent chemical resistance are suitably compatible, it is more preferably from 2,000 to 50,000, particularly preferably from 5,000 to 20,000. 000.

  In the ionizing radiation-curable resin composition of the second protective layer, the polycarbonate (meth) acrylate is preferably used together with a polyfunctional (meth) acrylate. That is, the ionizing radiation-curable resin composition preferably further contains a polyfunctional (meth) acrylate. The mass ratio of polycarbonate (meth) acrylate to polyfunctional (meth) acrylate is more preferably polycarbonate (meth) acrylate: polyfunctional (meth) acrylate = 98: 2 to 50:50. When the mass ratio of the polycarbonate (meth) acrylate to the polyfunctional (meth) acrylate is smaller than 98: 2 (that is, the amount of the polycarbonate (meth) acrylate is 98% by mass or less based on the total amount of the two components). And the chemical resistance is further improved. On the other hand, when the mass ratio of the polycarbonate (meth) acrylate to the polyfunctional (meth) acrylate is larger than 50:50 (that is, when the amount of the polycarbonate (meth) acrylate becomes 50% by mass or more based on the total amount of the two components). ), And the three-dimensional formability is further improved. Preferably, the mass ratio between the polycarbonate (meth) acrylate and the polyfunctional (meth) acrylate is 95: 5 to 60:40.

  The polyfunctional (meth) acrylate used in the present invention is not particularly limited as long as it is a bifunctional or higher (meth) acrylate. However, trifunctional or higher (meth) acrylate is preferable from the viewpoint of curability. Here, bifunctional means having two ethylenically unsaturated bonds {(meth) acryloyl group} in the molecule.

  The polyfunctional (meth) acrylate may be either an oligomer or a monomer, but is preferably a polyfunctional (meth) acrylate oligomer from the viewpoint of improving three-dimensional moldability.

  Examples of the polyfunctional (meth) acrylate oligomer include urethane (meth) acrylate-based oligomers, epoxy (meth) acrylate-based oligomers, polyester (meth) acrylate-based oligomers, and polyether (meth) acrylate-based oligomers. Here, the urethane (meth) acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by a reaction between a polyether polyol or a polyester polyol and a polyisocyanate with (meth) acrylic acid. The epoxy (meth) acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a bisphenol-type epoxy resin or a novolak-type epoxy resin having a relatively low molecular weight and esterifying it. Further, a carboxyl-modified epoxy (meth) acrylate oligomer obtained by partially modifying the epoxy (meth) acrylate-based oligomer with a dibasic carboxylic anhydride can also be used. As the polyester (meth) acrylate oligomer, for example, the hydroxyl group of a polyester oligomer having hydroxyl groups at both terminals obtained by condensation of a polyhydric carboxylic acid and a polyhydric alcohol is esterified with (meth) acrylic acid, or It can be obtained by esterifying a hydroxyl group at the terminal of an oligomer obtained by adding an alkylene oxide to a polyvalent carboxylic acid with (meth) acrylic acid. The polyether (meth) acrylate oligomer can be obtained by esterifying the hydroxyl group of the polyether polyol with (meth) acrylic acid.

  Further, other polyfunctional (meth) acrylate oligomers include a polybutadiene oligomer having a highly hydrophobic polybutadiene (meth) acrylate oligomer having a (meth) acrylate group in a side chain thereof, and a silicone (meta) having a polysiloxane bond in a main chain. ) Acrylate oligomers, aminoplast resin (meth) acrylate oligomers obtained by modifying aminoplast resins having many reactive groups in a small molecule, and the like.

  The polyfunctional (meth) acrylate monomer specifically includes ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6- Hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate hydroxypivalate, dicyclopentanyl di (meth) acrylate, caprolactone-modified di Cyclopentenyl di (meth) acrylate, ethylene oxide-modified di (meth) acrylate phosphate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropanate (Meth) acrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid-modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide-modified trimethylol Propane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene oxide-modified dipentaerythritol hexa (meth) acrylate, caprolactone-modified And dipentaerythritol hexa (meth) acrylate. The polyfunctional (meth) acrylate oligomer and the polyfunctional (meth) acrylate monomer described above may be used alone or in a combination of two or more.

  In the present invention, a monofunctional (meth) acrylate may be appropriately used together with the polyfunctional (meth) acrylate as long as the object of the present invention is not impaired, for the purpose of reducing the viscosity and the like. Examples of the monofunctional (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, and cyclohexyl ( Examples thereof include (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate. One of these monofunctional (meth) acrylates may be used alone, or two or more thereof may be used in combination.

  The content (solid content) of the polycarbonate (meth) acrylate in the ionizing radiation-curable resin composition forming the second protective layer 2 is not particularly limited, but is excellent in maintaining the uneven shape of the decorative sheet of the present invention. From the viewpoint of suitably satisfying the above-mentioned chemical resistance, the amount is preferably about 50 to 100% by mass, more preferably about 65 to 100% by mass.

<Other additives>
The resin composition used to form the second protective layer 2 may contain various additives according to the desired physical properties of the second protective layer 2. As the additive, the same additives as those exemplified in the first protective layer 1 are exemplified, and the amount thereof is also the same.

<Thickness of second protective layer 2>
The thickness of the second protective layer 2 after curing is not particularly limited, but is preferably a thickness after curing of the second protective layer 2 from the viewpoint of maintaining both the uneven shape and excellent chemical resistance. Is 0.01 to 20 μm, more preferably 12 to 20 μm, and still more preferably 15 to 20 μm. In the case where the second protective layer 2 has an uneven shape, the thickness of the second protective layer 2 means the thickness of the convex portion of the second protective layer 2.

<Method of forming second protective layer 2>
The second protective layer 2 may be formed so as to form a cured product of the curable resin composition, and the specific method is not particularly limited. The second protective layer 2 can be suitably formed by the method exemplified in the method of forming the first protective layer 1 (for example, the first method or the second method described above).

  The method for applying the resin composition used to form the second protective layer 2 may be the same as that for the first protective layer 1. Further, the applied resin composition (the uncured resin layer of the second protective layer 2) is irradiated with ionizing radiation such as an electron beam or an ultraviolet ray to cure the resin composition to form the second protective layer 2. The method is the same as that of the first protective layer 1. As described above, it is preferable that the first protective layer and the second protective layer 2 are simultaneously cured.

[Primer layer 4]
The primer layer 4 may be provided with a primer layer 4 on the surface of the second protective layer opposite to the first protective layer, if necessary, for the purpose of improving the adhesion of the second protective layer 2 and the like. it can. The primer layer 4 is provided between the base layer 3 and the second protective layer 2 when the base layer 3 is provided, and between the pattern layer 5 and the second protective layer 2 when the design layer 5 is provided. And / or a layer provided as necessary, for example, between the base material layer 3 and the picture layer 5.

  From the viewpoint of increasing the adhesion between the second protective layer 2 and the layer located on the side opposite to the first protective layer, it is preferable that the primer layer 4 is provided directly below the second protective layer 2. .

  Examples of the primer composition constituting the primer layer 4 include urethane resin, (meth) acrylic resin, (meth) acrylic-urethane copolymer resin, vinyl chloride-vinyl acetate copolymer, polyester resin, butyral resin, and chlorinated polypropylene. And chlorinated polyethylene as a binder resin are preferably used, and these resins can be used alone or in combination of two or more. Among these, urethane resin, (meth) acrylic resin, and (meth) acrylic-urethane copolymer resin are preferable.

  As the urethane resin, a polyurethane having a polyol (polyhydric alcohol) as a main component and an isocyanate as a crosslinking agent (curing agent) can be used. The polyol has two or more hydroxyl groups in the molecule, and examples thereof include polyester polyol, polyethylene glycol, polypropylene glycol, acrylic polyol, and polyether polyol. Examples of the isocyanate include a polyvalent isocyanate having two or more isocyanate groups in a molecule, an aromatic isocyanate such as 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated diphenylmethane diisocyanate. And aliphatic (or alicyclic) isocyanates. It is also possible to mix urethane resin and butyral resin.

  From the viewpoints of adhesion to the second protective layer 2 after crosslinking, difficulty in generating interaction after laminating the second protective layer 2, physical properties, and moldability, acrylic polyol or polyester polyol as a polyol and a crosslinking agent as a crosslinking agent It is preferable to use a combination of hexamethylene diisocyanate and 4,4-diphenylmethane diisocyanate, and it is particularly preferable to use an acrylic polyol in combination with hexamethylene diisocyanate.

  Examples of the (meth) acrylic resin include a homopolymer of (meth) acrylate, a copolymer of two or more different (meth) acrylate monomers, or a copolymer of (meth) acrylate with another monomer. Polymers include, for example, poly (meth) acrylate, poly (ethyl) acrylate, poly (meth) acrylate, butyl (meth) acrylate, and methyl (meth) acrylate. Butyl (meth) acrylate copolymer, ethyl (meth) acrylate-butyl (meth) acrylate copolymer, ethylene-methyl (meth) acrylate copolymer, styrene-methyl (meth) acrylate copolymer A (meth) acrylic resin composed of a homopolymer or a copolymer containing a (meth) acrylate such as (meth) acrylate is preferably used.

  As the (meth) acryl-urethane copolymer resin, for example, an acryl-urethane (polyester urethane) block copolymer resin is preferable. As the curing agent, the various isocyanates described above are used. The acryl-urethane (polyester urethane) block copolymer resin adjusts the acryl / urethane ratio (mass ratio) in a range of preferably 9/1 to 1/9, more preferably 8/2 to 2/8, as required. Is preferred.

  The thickness of the primer layer 4 is not particularly limited, but is, for example, about 0.5 to 20 μm, and preferably 1 to 5 μm.

  The primer layer 4 is made of a gravure coat, a gravure reverse coat, a gravure offset coat, a spinner coat, a roll coat, a reverse roll coat, a kiss coat, a wheeler coat, a dip coat, a solid coat by a silk screen, a wire bar coat, It is formed by a usual coating method such as a flow coat, a comma coat, a flowing coat, a brush coating, a spray coat, or a transfer coating method. Here, the transfer coating method is a method in which a coating film of a primer layer or an adhesive layer is formed on a thin sheet (film base material), and thereafter, the surface of a target layer in the decorative sheet is coated.

[Picture layer 5]
The picture layer 5 is a layer provided as necessary on the surface of the second protective layer opposite to the first protective layer, for the purpose of imparting decorativeness to the decorative sheet. The pattern layer 5 is provided between the base material layer 3 and the second protective layer 2 when the base material layer 3 is provided, and between the base material layer 3 and the primer layer 4 when the primer layer 4 is provided, or concealed. When a layer is provided, it is a layer provided as necessary, for example, between the concealing layer and the second protective layer 2.

  The picture layer 5 can be, for example, a layer in which a desired picture is formed using an ink composition. As the ink composition used for forming the picture layer 5, a mixture obtained by appropriately mixing a binder, a coloring agent such as a pigment and a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, a curing agent, and the like is used. .

  The binder used in the ink composition is not particularly limited, and examples thereof include a polyurethane resin, a vinyl chloride / vinyl acetate copolymer resin, a vinyl chloride / vinyl acetate / acryl copolymer resin, a chlorinated polypropylene resin, and an acrylic resin. , Polyester resin, polyamide resin, butyral resin, polystyrene resin, nitrocellulose resin, cellulose acetate resin and the like. These binders may be used alone or in a combination of two or more.

  The colorant used in the ink composition is not particularly limited. For example, carbon black (black ink), iron black, titanium white, antimony white, graphite, titanium yellow, red stalk, cadmium red, ultramarine, cobalt blue Organic pigments or dyes such as quinacridone red, isoindolinone yellow, and phthalocyanine blue; metal pigments composed of scale-like foil pieces such as aluminum and brass; scale-like foils such as titanium dioxide-coated mica and basic lead carbonate A pearl luster (pearl) pigment composed of pieces may be used.

  The pattern formed by the pattern layer 5 is not particularly limited, either. For example, a stone pattern, a cloth pattern, or a cloth-like pattern imitating the surface of a rock such as a wood pattern, a marble pattern (for example, a travertine marble pattern) is simulated. A cloth pattern, a tiled pattern, a brickwork pattern, and the like may be mentioned, and a pattern such as a parquet or a patchwork which combines these, or a single-color solid color (so-called solid surface) may be used. These patterns are formed by multicolor printing using normal yellow, red, blue, and black process colors, but also by multicolor printing using special colors prepared by preparing individual color plates constituting the pattern. Can be formed.

  The thickness of the picture layer is not particularly limited, but is, for example, 1 to 30 μm, and preferably 1 to 20 μm.

  The picture layer 5 may be a metal thin film layer. Examples of the metal forming the metal thin film layer include tin, indium, chromium, aluminum, nickel, copper, silver, gold, platinum, zinc, and alloys containing at least one of these. The method for forming the metal thin film layer is not particularly limited, and examples thereof include an evaporation method such as a vacuum evaporation method using the above-described metal, a sputtering method, and an ion plating method. The metal thin film layer may be provided on the entire surface or partially. In addition, a primer layer using a known resin may be provided on the front surface or the back surface of the metal thin film layer in order to improve the adhesiveness with an adjacent layer.

[Hiding layer]
The concealing layer is provided between the base layer 3 and the second protective layer 2 or between the base layer 3 and the primer layer 4 if the primer layer 4 is provided between the base layer 3 and the second protective layer 2 for the purpose of suppressing color change and variation of the base layer 3. Between the base layer 3 and the pattern layer 5 if necessary.

  The concealing layer is generally formed as an opaque color layer because the concealing layer is provided to prevent the base layer from adversely affecting the color tone and the pattern of the decorative sheet.

  The concealing layer is formed using an ink composition in which a binder is appropriately mixed with a coloring agent such as a pigment and a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, a curing agent, and the like. The ink composition for forming the concealing layer is appropriately selected from those used for the above-mentioned picture layer.

  The concealing layer usually has a thickness of about 1 to 20 μm, and is preferably formed as a so-called solid printing layer.

  The concealing layer is formed by a usual printing method such as gravure printing, offset printing, silk screen printing, printing by transfer from a transfer sheet, inkjet printing, etc .; gravure coat, gravure reverse coat, gravure offset coat, spinner coat, roll coat, reverse roll It is formed by an ordinary coating method such as a coat.

[Transparent resin layer]
The transparent resin layer is provided between the base layer 3 and the second protective layer 2 for improving the chemical resistance and abrasion resistance, and between the base layer 3 and the primer layer 4 when the primer layer 4 is provided. When the layer 5 is provided, between the pattern layer 5 and the second protective layer 2, or when the primer layer 4 and the pattern layer 5 are provided in this order on the base material layer 3, between the primer layer 4 and the pattern layer 5, This is a layer provided as needed. The transparent resin layer is a layer suitably provided in the decorative sheet integrated with the molding resin by the insert molding method.

  The resin component forming the transparent resin layer is appropriately selected according to transparency, three-dimensional moldability, shape stability, chemical resistance, and the like, and usually, a thermoplastic resin is used. Examples of the thermoplastic resin include, but are not particularly limited to, acrylic resins, polyolefin resins such as polypropylene and polyethylene, polycarbonate resins, ABS resins, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and vinyl chloride resins. Etc. are used. Among these thermoplastic resins, from the viewpoints of chemical resistance, abrasion resistance and the like, preferably, acrylic resin, polyolefin resin, polycarbonate resin, polyester resin; more preferably, acrylic resin, polyester resin; more preferably, polyester Resins.

  The transparent resin layer has been subjected to a physical or chemical surface treatment such as an oxidation method or an unevenness method on one or both sides, if necessary, in order to improve the adhesion with another layer in contact with the transparent resin layer. Is also good. These physical or chemical surface treatments are the same as the surface treatment applied to the base material layer.

  The thickness of the transparent resin layer is not particularly limited, but is, for example, 10 to 200 μm, and preferably 15 to 150 μm.

  The transparent resin layer may be laminated via an adhesive, or may be laminated directly without using an adhesive. When laminating via an adhesive, for example, polyester resin, polyether resin, polyurethane resin, epoxy resin, phenol resin resin, polyamide resin, polyolefin resin, poly Examples include vinyl acetate resin, cellulose resin, (meth) acrylic resin, polyimide resin, amino resin, rubber, and silicone resin. In the case of laminating without using an adhesive, it can be performed by a method such as an extrusion method, a sand lamination method, and a thermal lamination method.

[Backside adhesive layer]
The back surface adhesive layer (not shown) is provided on the side opposite to the outer surface of the decorative sheet as necessary for the purpose of enhancing the adhesion with the molding resin when molding the decorative resin molded article. Layer.

  For the back surface adhesive layer, a thermoplastic resin or a curable resin is used depending on the molding resin used for the decorative resin molded product.

  Examples of the thermoplastic resin used for forming the back surface adhesive layer include acrylic resin, acrylic-modified polyolefin resin, chlorinated polyolefin resin, vinyl chloride / vinyl acetate copolymer, thermoplastic urethane resin, thermoplastic polyester resin, and polyamide. Resin, rubber-based resin, and the like. One of these thermoplastic resins may be used alone, or two or more thereof may be used in combination.

  In addition, examples of the thermosetting resin used for forming the back surface adhesive layer include a urethane resin and an epoxy resin. One of these thermosetting resins may be used alone, or two or more thereof may be used in combination.

2. Decorative resin molded product The decorative resin molded product of the present invention is formed by integrating a molding resin with the decorative sheet of the present invention. That is, the decorative resin molded product of the present invention is a decorative resin molded product having an uneven shape on the outer surface, and, in order from the outside, at least a first protective layer configuring the uneven shape, 2 protective layer, and a molded resin layer 6. The first protective layer is formed of a cured product of a resin composition containing an ionizing radiation-curable resin and a thermoplastic resin. Is characterized by being formed from a cured product of an ionizing radiation-curable resin composition containing a polycarbonate (meth) acrylate.

  In the decorative resin molded product of the present invention, the uneven shape provided in the first protective layer 1 of the decorative sheet is suitably provided. The unevenness of the first protective layer 1 of the decorative sheet is easily changed greatly by the heat and pressure during the injection molding, but the uneven shape is effectively maintained in the decorative sheet of the present invention. . In the decorative resin molded product, the arithmetic mean roughness (Ra) of the surface of the first protective layer 1 is generally 0.1 to 30 μm, preferably 1 to 30, from the viewpoint of imparting an excellent design feeling or the like due to the uneven shape. 30 μm, more preferably 10 to 30 μm. The arithmetic average roughness (Ra) is a value measured on the surface of the first protective layer 1 of the decorative resin molded product according to JIS B 0601: 2001.

  FIG. 3 shows a cross-sectional structure of one embodiment of the decorative resin molded product of the present invention.

  The decorative resin molded article of the present invention is a step of forming a molded resin layer by injecting a resin onto the second protective layer 2 side (the surface opposite to the surface having irregularities) of the decorative sheet of the present invention. It can be manufactured by a method including Specifically, using the decorative sheet of the present invention, it is produced by various injection molding methods such as insert molding method, injection molding simultaneous decoration method, blow molding method and gas injection molding method.

  In the insert molding method, first, in a vacuum forming step, the decorative sheet of the present invention is vacuum-formed (off-line preforming) in advance to a molded product surface shape using a vacuum forming die, and then an unnecessary portion is trimmed as necessary. Obtain a molded sheet. This molded sheet is inserted into an injection mold, the injection mold is clamped, the resin in a fluid state is injected into the mold, solidified, and simultaneously with the injection molding, the decorative sheet is placed on the outer surface of the resin molded product. A decorative resin molded product is manufactured by integrating the two protective layers 2.

  More specifically, the decorative resin molded product of the present invention (or the decorative resin molded product with a thermoplastic resin film layer) is manufactured by an insert molding method including the following steps.

A vacuum forming step of forming the decorative sheet of the present invention into a three-dimensional shape in advance by a vacuum forming die,
A step of trimming an excess portion of the vacuum-formed decorative sheet to obtain a molded sheet, and inserting the molded sheet obtained in the above step into an injection molding die, closing the injection molding die, and molding the resin in a fluid state into a mold. A process of integrating the resin and the molded sheet by injecting it into the interior.

  In the vacuum forming step in the insert forming method, the decorative sheet may be heated and formed. The heating temperature at this time is not particularly limited, and may be appropriately selected depending on the type of the resin forming the decorative sheet, the thickness of the decorative sheet, and the like. For example, when the ABS resin film is used as the base material layer. In this case, the temperature can be usually about 100 to 250 ° C, preferably about 130 to 200 ° C. In addition, in the integration step, the temperature of the resin in a fluidized state is not particularly limited, but may be generally about 180 to 320 ° C, preferably about 220 to 280 ° C.

  Further, in the simultaneous injection molding decoration method, the decorative sheet of the present invention is arranged in a female mold that is also used as a vacuum forming mold provided with a suction hole for injection molding, and preforming (in-line preforming) is performed with this female mold. After the injection molding, the injection mold is closed, the resin in a fluid state is injected and filled into the mold, and the resin is solidified. At the same time as the injection molding, the second protection of the decorative sheet of the present invention is applied to the outer surface of the resin molded product. A decorative resin molded product is manufactured by integrating the layer 2 side.

  More specifically, the decorative resin molded product of the present invention (or the decorative resin molded product with a thermoplastic resin film layer) is manufactured by the simultaneous injection molding and decorating method including the following steps.

After installing the decorative sheet of the present invention such that the first protective layer 1 side of the decorative sheet faces the molding surface of the movable mold having a molding surface of a predetermined shape, the decorative sheet is heated. A step of preforming the decorative sheet by softening and sucking the vacuum from the movable mold side and bringing the softened decorative sheet into close contact with the molding surface of the movable mold;
After clamping the movable mold and the fixed mold having the decorative sheet adhered along the molding surface, the resin molding material in a flowing state is injected and filled into the cavity formed by both molds. An injection molding step in which the formed resin molded body and the decorative sheet are laminated and integrated by solidification, and a resin molded body in which the movable mold is separated from the fixed mold and all layers of the decorative sheet are laminated. Step of taking out.

  In the preliminary molding step of the injection molding simultaneous decorating method, the heating temperature of the decorating sheet is not particularly limited, and may be appropriately selected according to the type of resin constituting the decorating sheet, the thickness of the decorating sheet, etc. In the case where a polyester resin film or an acrylic resin film is used as the base material layer, the temperature can usually be about 70 to 130 ° C. In addition, in the injection molding step, the temperature of the resin in a fluidized state is not particularly limited, but can be generally about 180 to 320 ° C, preferably about 220 to 280 ° C.

  Further, the decorative resin molded product of the present invention (or a decorative resin molded product with a thermoplastic resin film layer) is formed on a previously prepared three-dimensional resin molded product (molded resin layer) such as a vacuum compression bonding method. It can also be produced by a decorating method of attaching the decorating sheet of the present invention.

  In the vacuum compression bonding method, first, the decorative sheet and the resin molded body of the present invention are placed in a vacuum pressing machine including a first vacuum chamber located on the upper side and a second vacuum chamber located on the lower side, and the decorative sheet is placed in the first vacuum chamber. The vacuum chamber side is installed in a vacuum crimping machine such that the resin molded body is on the second vacuum chamber side, and the second protective layer 2 side of the decorative sheet is facing the resin molded body side, and the two vacuum chambers are in a vacuum state. And The resin molded body is installed on a vertically movable platform provided on the second vacuum chamber side. Next, while the first vacuum chamber is pressurized, the molded body is pressed against the decorative sheet using the elevating platform, and the resin molded body is stretched while stretching the decorative sheet using the pressure difference between the two vacuum chambers. Stick on the surface of. Finally, the two vacuum chambers are opened to the atmospheric pressure, and an extra portion of the decorative sheet is trimmed if necessary, whereby the decorative resin molded product of the present invention can be obtained.

  In the vacuum compression bonding method, it is preferable to include a step of heating the decorative sheet in order to soften the decorative sheet and enhance the formability before the step of pressing the formed body against the decorative sheet. The vacuum compression bonding method including this step may be particularly called a vacuum heat compression bonding method. The heating temperature in this step may be appropriately selected depending on the type of resin constituting the decorative sheet, the thickness of the decorative sheet, and the like, provided that a polyester resin film or an acrylic resin film is used as the base material layer. , Usually about 60 to 200 ° C.

  In the decorative resin molded product of the present invention, the molding resin layer may be formed by selecting a molding resin according to the application. The molding resin may be a thermoplastic resin or a thermosetting resin.

  Examples of the thermoplastic resin used as the molding resin include polyolefin resins such as polyethylene and polypropylene, ABS resins, styrene resins, polycarbonate resins, acrylic resins, and vinyl chloride resins. One of these thermoplastic resins may be used alone, or two or more thereof may be used in combination.

  Examples of the thermosetting resin used as the molding resin include a urethane resin and an epoxy resin. One of these thermosetting resins may be used alone, or two or more thereof may be used in combination.

  Since the decorative resin molded product of the present invention has excellent chemical resistance, abrasion resistance and the like, for example, interior materials or exterior materials of vehicles such as automobiles; It can be used as fittings such as window frames and door frames; interior materials for buildings such as walls, floors and ceilings; housings for home electric appliances such as television receivers and air conditioners; containers and the like.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the embodiments.

Example 1
An ABS resin film (thickness: 475 μm) was used as the base material layer. A picture layer (solid pattern layer (thickness: 5 μm)) was formed on the base layer by gravure printing using an ink composition containing an acrylic resin. Next, on the pattern layer, a primer layer containing a binder resin composed of a two-part curable resin containing 100 parts by mass of a main agent (acryl polyol / urethane, mass ratio of 9/1) and 7 parts by mass of a curing agent (hexamethylene diisocyanate) The resin composition for application was applied and dried to form a primer layer having a thickness of 2 μm, thereby obtaining a laminate in which a base layer / a pattern layer / a primer layer were sequentially laminated.

  Next, embossing was performed on the primer layer side of the obtained laminate to form an uneven shape on the primer layer. As the emboss plate, a stripe pattern having a depth of 40 μm was used. Next, in order to form a second protective layer, an ionizing radiation-curable resin (EB resin A shown in Table 1, which will be described in detail later) is cured to a thickness (cured shape of the second protective layer). (Thickness of the protruding portion) was 10 μm to form an uncured resin layer. The uncured resin layer was cured by applying an acceleration voltage of 165 kV and an irradiation dose of 50 kGy (5 Mrad) from above the uncured resin layer. Next, in order to form a first protective layer, a resin composition prepared by blending a thermoplastic resin (acrylic resin) and an ionizing radiation resin (EB resin B shown in Table 1, which will be described later in detail), An uncured resin layer was formed by coating so that the thickness after curing (the thickness of the projections of the unevenness of the first protective layer) was 10 μm. Similarly to the second protective layer, an acceleration voltage of 165 kV and an irradiation dose of 50 kGy (5 Mrad) are applied and cured from above the uncured resin layer to form a first protective layer and a second protective layer having irregularities. Thus, a decorative sheet was obtained. The uneven shape of the surface layer corresponds to the uneven shape of the primer layer.

  Next, a decorative resin molded product was manufactured using the obtained decorative sheet. Specifically, the decorative sheet was heated with an infrared heater at 280 ° C. for 20 seconds, and preformed by vacuum forming so as to conform to the shape (plate shape) in the mold (maximum stretch ratio 50%). Next, the preform was inserted into the mold, the injection resin was injected into the cavity of the mold, the decorative sheet and the injection resin were integrally formed, and the decorative resin was taken out of the mold to obtain a decorative resin molded product. .

Comparative Examples 1 and 2
A decorative sheet and a decorative resin molded product were obtained in the same manner as in Example 1 except that the resin shown in Table 1 was used as the first protective layer without forming the second protective layer.

Comparative Example 3
A decorative sheet and a decorative resin molded product were obtained in the same manner as in Example 1 except that the resins shown in Table 1 were used as the resin for forming the first protective layer and the second protective layer.

Comparative Example 4
A decorative sheet and a decorative resin molded product were obtained in the same manner as in Example 1 except that the protective layer was not formed as shown in Table 1.

The resins of the first protective layer and the second protective layer described in Table 1 are as follows. The mixing ratio (mass ratio) of the EB resin B and the acrylic resin is 1: 3.
EB resin A: 95 parts by mass of a bifunctional urethane acrylate having a polycarbonate skeleton (weight average molecular weight of 20,000) and 5 parts by mass of a 6-functional urethane acrylate (weight average molecular weight of 3,000) EB resin B: bifunctional Urethane acrylate monomer (molecular weight 500)
Acrylic resin: acrylic polymer (weight average molecular weight 120,000)

<Measurement of surface roughness of decorative sheet>
Various surface roughness (arithmetic average roughness (Ra)) of the outer surface of each decorative sheet obtained above was measured in accordance with JIS B0601: 2001. As a measuring device, a surface roughness measuring device (trade name “Surfcoder SE-30K” manufactured by Kosaka Laboratory Co., Ltd.) was used.

<Measurement of surface roughness of decorative resin molded product>
The arithmetic average roughness (Ra) of the outer surface of each decorative resin molded product was measured in the same manner as in the above <Measurement of surface roughness of decorative sheet>. Table 1 shows the measurement results.

<Roughness maintenance>
◎: There is no change in the design feeling due to the uneven shape compared to before molding ○: There is a slight change compared to before the molding, but there is no significant change in the design feeling due to the uneven shape △: The uneven shape compared to before the molding ×: Feel the design feeling is thin due to the unevenness

<Chemical resistance of decorative sheet>
5 ml of sunscreen cosmetic was dropped on the surface of each decorative sheet obtained above and left in an oven at 60 ° C. for 4 hours. Next, the decorative sheet was taken out, the surface was washed away with a neutral detergent solution, and then the state of the dripped portion was visually observed, and the chemical resistance of the decorative sheet was evaluated according to the following criteria. Table 1 shows the results. The sunscreen cosmetics used are commercially available and contain, as components, avobenzone (3%), homosalate (10%), octisalate (5%), octocrylene (2.8%), and oxybenzone (6%). It has high erosion on the resin surface.

◎: There is no change in the appearance of the decorative sheet surface ○: There is a slight gloss change on the decorative sheet surface, but it does not significantly impair the design △: There is a gloss change on the decorative sheet surface, but it is acceptable in actual use X obtained: whitening, swelling and dissolution on the decorative sheet surface

DESCRIPTION OF SYMBOLS 1 1st protective layer 2 2nd protective layer 3 Base material layer 4 Primer layer 5 Picture layer 6 Molding resin layer

Claims (12)

A decorative sheet having an uneven shape on the outer surface,
In order from the outside, at least, a first protective layer constituting the uneven shape, and a second protective layer,
The first protective layer is formed of a cured product of a resin composition containing an ionizing radiation-curable resin and a thermoplastic resin,
The decorative sheet, wherein the second protective layer is formed of a cured product of an ionizing radiation-curable resin composition containing polycarbonate (meth) acrylate.   The decorative sheet according to claim 1, wherein the second protective layer has an uneven shape along the uneven shape of the first protective layer.   The decorative sheet according to claim 1, wherein in the first protective layer, the resin composition includes an ionizing radiation-curable resin and a thermoplastic resin in a mass ratio of 10:90 to 25:75.   The decorative sheet according to any one of claims 1 to 3, wherein in the first protective layer, a weight average molecular weight of the thermoplastic resin is in a range of 90,000 to 150,000.   The decorative sheet according to any one of claims 1 to 4, wherein in the first protective layer, the number of functional groups of a monomer contained in the ionizing radiation-curable resin is in a range of 2 to 6.   The decorative sheet according to any one of claims 1 to 5, wherein in the first protective layer, a molecular weight of a monomer contained in the ionizing radiation-curable resin is in a range of 200 to 2,000.   The decorative sheet according to any one of claims 1 to 6, wherein a base material layer is laminated on a surface of the second protective layer opposite to the first protective layer.   The decorative sheet according to any one of claims 1 to 7, wherein a primer layer is laminated on a surface of the second protective layer opposite to the first protective layer.   The decorative sheet according to any one of claims 1 to 8, wherein the arithmetic average roughness Ra of the outer surface is 0.1 µm or more and 100 µm or less.   The decorative sheet according to any one of claims 1 to 9, which is used in an insert molding method or an injection molding simultaneous decoration method. A decorative resin molded article having an uneven shape on the outer surface,
In order from the outside, at least, a first protective layer constituting the uneven shape, a second protective layer, and a molding resin layer,
The first protective layer is formed of a cured product of a resin composition containing an ionizing radiation-curable resin and a thermoplastic resin,
The decorative resin molded article, wherein the second protective layer is formed of a cured product of an ionizing radiation-curable resin composition containing polycarbonate (meth) acrylate.   The decorative sheet according to any one of claims 1 to 10, further comprising a step of laminating a molded resin layer by injecting a resin on a surface opposite to the surface having the uneven shape of the decorative sheet according to any one of claims 1 to 10. Production method.