JP2010253917A - Decorative sheet, method for manufacturing decorative resin molded product, and decorative resin molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decorative sheet which has a high abrasion resistance and a high scratch resistance, is excellent in moldability, has a surface protective layer in which a crack or the like does not generated, and is used for molding a decorative molded product with a high designability, and to provide a method of manufacturing decorative resin molded article using the decorative sheet and the decorative resin molded article manufactured by the manufacturing method. <P>SOLUTION: The decorative sheet 10 for insert molding is obtained by laminating at least the surface protective layer 14 on a support 11 comprising an ABS resin, wherein the flexural modulus of the support is 1,500-3,000 MPa, the thickness of the support is 100-500 μm, the surface protective layer is produced by crosslinking curing an ionizing radiation curable resin composition, the tensile modulus of elasticity of the ionizing radiation curable resin composition is >100 MPa and <1,000 MPa, and the coefficient of static friction of the surface is 1.0 or less. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a decorative sheet, a method for manufacturing a decorative resin molded product using the decorative sheet, and a decorative resin molded product manufactured by the manufacturing method.

  A decorative molded product decorated by laminating a decorative sheet on the surface of the molded product is used in various applications such as vehicle interior parts. As a method for molding such a decorative molded product, the decorative sheet is molded into a three-dimensional shape in advance by a vacuum mold, the molded sheet is inserted into an injection mold, and a fluid resin is injected into the mold. Thus, there is an insert molding method in which the resin and the molded sheet are integrated (for example, see Patent Document 1).

  By the way, the decorative molded product is provided with a surface protective layer for the purpose of improving the wear resistance and scratch resistance of the surface. However, in the above-mentioned insert molding method, the decorative sheet is formed into a three-dimensional shape in advance by a vacuum mold, and the decorative sheet is inserted into the injection mold by a vacuum / pneumatic action or the resin in a fluid state. In the process of injecting the resin into the mold and integrating the resin and the molded sheet, it is stretched beyond the minimum required amount due to the pressure of the molten resin and shear stress, etc. There was a problem of cracks.

In order to improve the moldability of the surface protective layer, a thermosetting resin has been used as the surface protective layer (for example, see Patent Document 2). The thermosetting resin showed good results for moldability, and the surface protective layer was hardly cracked, but the surface wear resistance and scratch resistance of the decorative molded product were not satisfactory.
In addition, by using an ionizing radiation curable resin such as an ultraviolet curable resin as the surface protective layer and increasing the crosslink density of the resin that forms the surface protective layer of the decorative sheet, the surface wear resistance of the decorative molded product can be increased. Attempts were made to improve the scratch resistance, but there was a problem that cracks occurred in the curved surface of the molded product during molding.
Furthermore, although an ionizing radiation curable resin such as an ultraviolet curable resin is used as a surface protective layer, a method of making it a semi-cured state at the stage of a decorative sheet and completely curing it after decorative molding has been tried (Patent Document) 2), the surface protective layer containing the uncured resin component is easily damaged and difficult to handle, and there is a problem of mold contamination due to the uncured resin component adhering to the mold. In order to solve this problem, there is a method of providing a protective film on the semi-cured surface protective layer. However, the manufacturing is complicated and the cost is increased. In addition, since it is necessary to irradiate the three-dimensional molded product with ultraviolet rays, a separate facility for irradiating the three-dimensional molded product with ultraviolet rays is required.

JP 2004-322501 A Japanese Patent Application Laid-Open No. 6-134859

  In view of the above problems, the present invention is a decorative molded product having high wear resistance and scratch resistance, having a surface protective layer that has good moldability and is free from cracks, and has high design properties. The object is to provide a decorative sheet used for molding, a method for producing a decorative resin molded product using the decorative sheet, and a decorative resin molded product produced by the production method.

  As a result of intensive studies to achieve the above object, the present inventors have found a decorative sheet for insert molding in which a surface protective layer is laminated on a support used as a backer layer in a conventional insert molding method. The inventors have found that the above-mentioned problems can be solved by using a specific support, using an ionizing radiation curable resin composition as the surface protective layer, and controlling the static friction coefficient of the surface. The present invention has been completed based on such findings.

That is, the present invention
(1) A decorative sheet for insert molding formed by laminating at least a surface protective layer on a support made of ABS resin, the flexural modulus of the support being 1500 to 3000 MPa, and the thickness of the support Is 100 to 500 μm, the surface protective layer is obtained by crosslinking and curing the ionizing radiation curable resin composition, and the tensile elastic modulus of the ionizing radiation curable resin composition measured by the following method is more than 100 MPa to less than 1000 MPa. And a decorative sheet for insert molding, wherein the surface has a static friction coefficient of 1.0 or less,
(Measurement method of tensile modulus)
A resin composition for forming a surface protective layer is applied on a biaxially stretched polyester film so that the thickness after curing is 20 μm, and the coating film cured by irradiating with ionizing radiation is applied from the polyester film. Peel off to make a sample. The sample is measured at a tensile speed of 50 mm / min using a tensile tester.
(2) A vacuum forming step in which the decorative sheet for insert molding described in (1) above is formed into a three-dimensional shape in advance using a vacuum forming die, a step of trimming excess portions to obtain a formed sheet, and injection molding the formed sheet A method of manufacturing a decorative resin molded product, which includes a step of inserting into a mold, closing an injection mold, injecting a resin in a fluid state into the mold and integrating the resin and the molded sheet, and (3) (2) above Decorative resin molded product produced by the production method described in 1.
Is to provide.

  The decorative sheet for insert molding of the present invention has excellent wear resistance, scratch resistance and scratch resistance, and has good moldability because the surface protective layer does not crack during molding, and is low in cost. A decorative sheet for insert molding can be provided.

It is a schematic diagram which shows the cross section of the decorating sheet of this invention. It is a schematic diagram which shows the cross section of the other aspect of the decorating sheet of this invention.

The decorative sheet for insert molding of the present invention is a decorative sheet for insert molding formed by laminating at least a surface protective layer on a support. Hereinafter, the structure of the decorative sheet for insert molding of the present invention will be described in detail with reference to FIGS. 1 and 2.
FIG. 1 is a schematic view showing a cross section of a decorative sheet for insert molding (hereinafter, simply referred to as “decorative sheet of the present invention”) 10 of the present invention. The decorative sheet of the present invention has a structure in which a picture layer 12 and a surface protective layer 14 are laminated in this order on a support 11, and as shown in FIG. A low gloss pattern ink layer 13 may be disposed between the two. Further, a concealing layer may be provided between the support 11 and the pattern layer 12, and a primer layer may be further provided between the pattern layer 12 and the low gloss pattern ink layer 13.
FIG. 2 is a schematic view showing a cross section of another embodiment of the decorative sheet for insert molding of the present invention. In the embodiment shown in FIG. 2, a pattern layer 12 and a surface protective layer 14 may be laminated on the support 11 in this order, and a primer layer may be provided between the pattern layer 12 and the surface protective layer 14. In this embodiment, the design that does not have the low gloss pattern ink layer 13 and is highly glossy and excellent in smoothness and specularity can be expressed as described in detail later.

The support 11 in the decorative sheet 10 of the present invention is a support called a backer layer in a conventional insert molding decorative sheet. In a conventional insert molding decorative sheet, a pattern layer or the like is separately printed on a base material sheet, and the same resin as the injection molding resin or a resin having high adhesiveness and a resin having high adhesiveness is used as a backer layer on the base material. Laminate and insert molding. The decorative sheet of the present invention is characterized in that a pattern layer or the like is directly laminated on the support 11, and a so-called backer layer is not used.
The support 11 used for the decorative sheet 10 of the present invention is made of ABS resin. ABS resin is a preferred resin in terms of preventing cracks, scratches and the like on the surface of the molded body.
Moreover, the support body 11 used for the decorative sheet 10 of the present invention has a flexural modulus of 1500 to 3000 MPa. When the flexural modulus is 1500 MPa or more, the moldability is good, and particularly the shape retention after vacuum forming is excellent. Moreover, the surface hardness represented by the pencil hardness test is improved, and a decorative sheet that is strong against so-called scratches can be obtained. On the other hand, sufficient moldability can be ensured when the flexural modulus is 3000 MPa or less. From the above viewpoint, the flexural modulus of the support 11 is more preferably in the range of 1700 to 2600 MPa. The flexural modulus is measured according to JIS K7171 (ISO178).

  The thickness of the support 11 is in the range of 100 to 500 μm. When the thickness is 100 μm or more, sufficient strength can be imparted to the decorative sheet 10, and the film thickness after following the shape is stabilized during vacuum forming. In addition, during the injection molding, the decorative sheet does not wrinkle due to the flow of the molten resin. On the other hand, when the thickness is 500 μm or less, it is possible to sufficiently follow a fine uneven shape during vacuum forming, and trimming after vacuum forming is easy. From the above viewpoint, the thickness of the support 11 is more preferably in the range of 200 to 400 μm.

  In addition, the support 11 may be either a single layer or a plurality of layers. In the case of a plurality of layers, for example, the surface of the support 11 is subjected to an anti-blocking treatment, a primer treatment or an acid treatment, and the anti-blocking layer on the surface. The primer layer or the acid-modified layer is formed.

Moreover, in order to improve the adhesiveness with the layer provided on the said support body 11, physical or chemical surface treatments, such as an oxidation method and an uneven | corrugated method, can be given if desired.
Examples of the oxidation method include corona discharge treatment, chromium oxidation treatment, flame treatment, hot air treatment, ozone / ultraviolet treatment method, and examples of the unevenness method include a sand blast method and a solvent treatment method. These surface treatments are appropriately selected according to the type of the support, but in general, the corona discharge treatment method is preferably used from the viewpoints of effects and operability.
Further, the support may be subjected to a treatment such as forming a primer layer, or a coating for adjusting the color or a pattern from a design viewpoint may be formed in advance.

  Next, the pattern layer 12 shown in FIG. 1 gives decorativeness to the resin molded product, and is formed by printing various patterns using ink and a printing machine. As patterns, there are stone patterns imitating the surface of rocks such as wood grain patterns, marble patterns (for example, travertine marble patterns), fabric patterns imitating cloth or cloth patterns, tiled patterns, brickwork patterns, etc. There are also patterns such as marquetry and patchwork that combine these. These patterns are formed by multicolor printing with the usual yellow, red, blue and black process colors, as well as by multicolor printing with special colors prepared by preparing the individual color plates that make up the pattern. Is done.

As the pattern ink used for the pattern layer 12, a binder and a colorant such as a pigment and a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, and a curing agent are appropriately mixed. The binder is not particularly limited, and examples thereof include polyurethane resins, vinyl chloride / vinyl acetate copolymer resins, vinyl chloride / vinyl acetate / acrylic copolymer resins, chlorinated polypropylene resins, acrylic resins, and polyesters. Arbitrary resins, polyamide resins, butyral resins, polystyrene resins, nitrocellulose resins, cellulose acetate resins and the like may be used alone or in combination of two or more.
Colorants include carbon black (black), iron black, titanium white, antimony white, yellow lead, titanium yellow, petal, cadmium red, ultramarine, cobalt blue and other inorganic pigments, quinacridone red, isoindolinone yellow, phthalocyanine Organic pigments or dyes such as blue, metallic pigments composed of scaly foil pieces such as aluminum and brass, pearlescent pigments composed of scaly foil pieces such as titanium dioxide-coated mica and basic lead carbonate, and the like are used.

  The concealment layer provided as desired between the support 11 and the pattern layer 12 is provided for the purpose of preventing the color of the decorative sheet from being affected by changes and variations in the color of the surface of the support 11. . Usually, it is often formed with an opaque color, and a so-called solid printing layer having a thickness of about 1 to 20 μm is preferably used.

In the decorative sheet 10 shown in FIG. 1, an example in which a low-gloss pattern ink layer 13 is provided as one preferred embodiment is shown. The low gloss pattern ink layer 13 gives a decorative property to the resin molded product. By synchronizing with the pattern layer 12, the resin molded product can be given a texture such as matte or uneven feeling. This low gloss pattern ink layer 13 is partially provided and interacts with a surface protective layer 14 to be described in detail later, and a low gloss region 15 is formed in the surface protective layer immediately above and in the vicinity thereof. When the decorative sheet 10 of the present invention is viewed from the surface protective layer 14 side, since the low gloss region 15 is visually recognized as a concave portion, the low gloss region 15 as a whole is visually recognized as an uneven pattern. . The low gloss region 15 is represented by a set of points in the drawing.
Further, the upper portion of the low gloss region 15 on the outermost surface of the surface protective layer 14 may be raised with the formation of the low gloss pattern ink layer 13 and may have a convex shape 16.

  The difference in gloss caused by the low gloss pattern ink layer 13 occurs when an uncured product of ionizing radiation curable resin for forming the surface protective layer 14 described in detail later is applied to the surface of the low gloss pattern ink layer 13. In addition, the resin component of the low-gloss pattern ink layer 13 and the surface protective layer 14 exhibit interaction such as partial elution, dispersion, and mixing by appropriately selecting combinations of materials and coating conditions. Conceivable.

The low gloss pattern ink forming the low gloss pattern ink layer 13 has a property of causing interaction with the ionizing radiation curable resin composition forming the surface protective layer 14, and the ionizing radiation curable resin composition ( It is appropriately selected in relation to the uncured product. Specifically, an ink having a non-crosslinkable resin as the binder resin is preferable, and for example, a thermoplastic (non-crosslinked type) urethane resin, a polyvinyl acetal resin, or the like is preferable. If necessary, unsaturated polyester resin, acrylic resin, or vinyl chloride-vinyl acetate copolymer is used to adjust the degree of expression of the low gloss region and the contrast of the gloss difference between the low gloss region and its surroundings. Can be mixed.
The low-gloss pattern ink that forms the low-gloss pattern ink layer 13 can contain a colorant and can provide a pattern pattern by itself, but it is not always necessary to add a colorant and color it. Of the patterns to be expressed by the pattern layer 12, the pattern having visual recesses due to the gloss difference can be obtained by erasing the gloss and synchronizing the portion where the recesses are to be visually expressed with the low gloss pattern ink layer 13. For example, when a wood grain pattern is to be expressed by the pattern layer 12, the conduit portion is visually recessed due to gloss difference by synchronizing the ink portion of the low gloss pattern ink layer 13 with the wood conduit portion. A pattern is obtained. In particular, the decorative sheet 10 of the present invention can be provided with a low gloss pattern ink layer 13 on the pattern layer 12 directly or via a transparent primer layer by printing or the like. Tuning with the layer 12 is easy and an excellent design expression can be realized.

About the application quantity of the low gloss pattern ink which forms the low gloss pattern ink layer 13, it is preferable that it is the range of 0.1-10 g / m < ² >. When the amount is 0.1 g / m ² or more, the above-described low gloss pattern ink and the ionizing radiation curable resin composition interact with each other, and a sufficiently low gloss region is obtained. Is obtained. On the other hand, if it is 10 g / m ² or less, there is no mechanical restriction when printing low gloss pattern ink, and it is economically advantageous. From the above viewpoints, the coating amount of the low gloss pattern ink is preferably in the range of 0.5 to 5 g / m ² .

Further, it is preferable that an extender pigment is contained in the low gloss pattern ink composition for forming the low gloss pattern ink layer 13. By incorporating extender pigments, thixotropy can be imparted to the low gloss pattern ink composition, and the shape of the low gloss pattern ink composition is maintained when the low gloss pattern ink layer 13 is printed using a plate. Is done. As a result, the sharpness of the unevenness at the end portion that transitions from the convex portion to the concave portion can be emphasized, and a sharp design expression is possible.
The extender pigment used in the present invention is not particularly limited, and is suitably selected from, for example, silica, talc, clay, barium sulfate, barium carbonate, calcium sulfate, calcium carbonate, magnesium carbonate and the like. Of these, silica, which is a material having a high degree of freedom in material design such as oil absorption, particle size, pore volume, etc., and excellent in designability, whiteness, and coating stability as an ink, is preferred. Is preferred. As a particle size of a silica, the range of 0.1-5 micrometers is preferable. When it is 0.1 μm or more, the thixotropy of the ink does not become extremely high when it is added to the ink, and the viscosity of the ink does not increase too much, so that printing can be controlled easily. Also, when trying to express the matte of the conduit pattern portion, the ink coating thickness of the conduit pattern portion is usually 5 μm or less, and if the silica particle size is smaller than the coating thickness, the head of the particle is relatively suppressed. Because it is inconspicuous, visual discomfort is unlikely to occur.
The content of these extender pigments in the low gloss pattern ink composition is preferably in the range of 5 to 15% by mass. When the content is 5% by mass or more, sufficient thixotropy can be imparted to the low gloss pattern ink composition, and when it is 15% by mass or less, the effect of imparting low gloss is not observed at all.

In the decorative sheet 10 of the present invention, a primer layer may be provided between the pattern layer 12 and the low gloss pattern ink layer 13 as desired. The primer layer has a function of leveling the surface of the pattern layer 12 and the like on the support 11 and enhancing the adhesion between the low gloss pattern ink layer 13 and the surface protective layer 14. Moreover, it has the effect of making it difficult for fine cracks and whitening to occur in the stretched portion of the surface protective layer 14.
The primer composition constituting the primer layer is (meth) acrylic resin, urethane resin, (meth) acrylic / urethane copolymer resin, vinyl chloride-vinyl acetate copolymer, polyester resin, butyral resin, chlorinated polypropylene, chlorine Polyethylene or the like is used.
Moreover, it is preferable that the thickness of a primer layer is about 0.1-10 micrometers. When it is 0.1 μm or more, the effect of preventing the surface protective layer from cracking, breaking, whitening, etc. can be sufficiently exerted. On the other hand, if the thickness of the primer layer is 10 μm or less, when the primer layer is applied, the coating film is stable in drying and curing, so that the moldability does not fluctuate. From the above points, the thickness of the primer layer is more preferably 1 to 10 μm.

  As a method for forming the primer layer, it can be formed directly by a coating method, or a transfer method can be used. When the primer layer is formed by direct coating, gravure coating, gravure reverse coating, gravure offset coating, spin coating, roll coating, reverse roll coating, kiss coating, wheeler coating, dip coating, silk screen solid coating, wire bar coating , Flow coat, comma coat, pouring coat, brush coating, spray coating and the like can be used. The transfer coating method is a method in which a coating film of a primer layer is once formed on a thin sheet (film substrate) and then coated on the surface of the substrate, and the coating film of the coating composition is coated on the substrate. In addition, there are a laminating method for adhering to a three-dimensional object, and a transfer method in which only a support sheet is peeled after bonding a transfer sheet once formed with a coating film and, if necessary, an adhesive layer on a releasable support sheet.

In the decorative sheet 10 of the present invention, a surface protection layer 14 obtained by crosslinking and curing an ionizing radiation curable resin composition is used.
The ionizing radiation curable resin refers to a resin having an energy quantum capable of crosslinking and polymerizing molecules in an electromagnetic wave or a charged particle beam, that is, a resin that is crosslinked and cured by irradiation with ultraviolet rays or electron beams. Specifically, it can be appropriately selected from polymerizable monomers, polymerizable oligomers, or prepolymers conventionally used as ionizing radiation curable resins.

  Typically, a (meth) acrylate monomer having a radical polymerizable unsaturated group in the molecule is suitable as the polymerizable monomer, and among them, a polyfunctional (meth) acrylate is preferable. Here, “(meth) acrylate” means “acrylate or methacrylate”, and other similar ones have the same meaning. The polyfunctional (meth) acrylate is not particularly limited as long as it is a (meth) acrylate having two or more ethylenically unsaturated bonds in the molecule. 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, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone-modified dicyclopentenyl di (meth) acrylate, ethylene oxide-modified phosphate di ( (Meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylo Propane 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, etc. Is mentioned. These polyfunctional (meth) acrylates may be used singly or in combination of two or more.

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

  Next, as the polymerizable oligomer, an oligomer having a radical polymerizable unsaturated group in the molecule, for example, epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, polyether (meth) acrylate The system etc. are mentioned. Here, the epoxy (meth) acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it. . Further, a carboxyl-modified epoxy (meth) acrylate oligomer obtained by partially modifying this epoxy (meth) acrylate oligomer with a dibasic carboxylic acid anhydride can also be used. The urethane (meth) acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by reaction of polyether polyol or polyester polyol and polyisocyanate with (meth) acrylic acid. Examples of polyester (meth) acrylate oligomers include esterification of hydroxyl groups of polyester oligomers having hydroxyl groups at both ends obtained by condensation of polycarboxylic acid and polyhydric alcohol with (meth) acrylic acid, It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding an alkylene oxide to a 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.

  Furthermore, other polymerizable oligomers include polybutadiene (meth) acrylate oligomers with high hydrophobicity that have (meth) acrylate groups in the side chain of polybutadiene oligomers, and silicone (meth) acrylate oligomers that have polysiloxane bonds in the main chain. In a molecule such as an aminoplast resin (meth) acrylate oligomer modified with an aminoplast resin having many reactive groups in a small molecule, or a novolak epoxy resin, bisphenol epoxy resin, aliphatic vinyl ether, aromatic vinyl ether, etc. There are oligomers having a cationic polymerizable functional group.

Among the polymerizable monomers and polymerizable oligomers or prepolymers, a polyester (meth) acrylate oligomer having a weight average molecular weight Mw of 10,000 or more may be used at least in part from the viewpoint of imparting moldability to the decorative sheet. Particularly preferred are bifunctional polyester (meth) acrylate oligomers.
In addition to the polyester (meth) acrylate oligomer having a weight average molecular weight Mw of 10,000 or more, other polymerizable monomers, polymerizable oligomers and prepolymers can be used in combination as appropriate according to the physical properties desired to be imparted. Specifically, in order to impart surface hardness and scratch resistance, it is preferable that 10 or more parts by mass of bifunctional or higher, preferably trifunctional or higher urethane acrylate is added to 100 parts by mass of polyester acrylate. Monofunctionality is excellent in moldability after curing, but the crosslink density is sparse and the surface hardness may be inferior. On the other hand, if the amount is less than 10 parts by mass, the effects of surface hardness and scratch resistance may not be sufficiently obtained depending on applications.

When an ultraviolet curable resin is used as the ionizing radiation curable resin, it is desirable to add about 0.1 to 5 parts by mass of the photopolymerization initiator with respect to 100 parts by mass of the resin. The initiator for photopolymerization can be appropriately selected from those conventionally used and is not particularly limited. For example, for a polymerizable monomer or polymerizable oligomer having a radically polymerizable unsaturated group in the molecule. Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2 -Phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propane-1 - 4- (2-hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4′-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2 -Tertiary butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal It is done.
Examples of the polymerizable oligomer having a cationic polymerizable functional group in the molecule include aromatic sulfonium salts, aromatic diazonium salts, aromatic iodonium salts, metallocene compounds, and benzoin sulfonic acid esters.
Moreover, as a photosensitizer, p-dimethylbenzoic acid ester, tertiary amines, a thiol type sensitizer, etc. can be used, for example.

  In the present invention, it is preferable to use an electron beam curable resin as the ionizing radiation curable resin. This is because the electron beam curable resin can be made solvent-free, is more preferable from the viewpoint of environment and health, and does not require a photopolymerization initiator, and can provide stable curing characteristics.

In the said ionizing radiation curable resin composition, other resin can be contained in the range with the effect of this invention. For example, when it is desired to impart flexibility to the decorative sheet 10 of the present invention, a thermoplastic resin can be added. On the other hand, when resistance to a solvent is required, it is preferable not to contain a thermoplastic resin.
Thermoplastic resins include (meth) acrylic resins such as (meth) acrylic acid esters, polyvinyl acetals (butyral resins) such as polyvinyl butyral, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, vinyl chloride resins, urethane resins, Polyolefins such as polyethylene and polypropylene, styrene resins such as polystyrene and α-methylstyrene, acetal resins such as polyamide, polycarbonate and polyoxymethylene, fluororesins such as ethylene-tetrafluoroethylene copolymer, polyimide, polylactic acid, A polyvinyl acetal resin, a liquid crystalline polyester resin, etc. are mentioned, These may be used individually by 1 type or in combination of 2 or more types. When combining 2 or more types, the copolymer of the monomer which comprises these resin may be sufficient, and each resin may be mixed and used.

Among the above thermoplastic resins, those having a (meth) acrylic resin as a main component are preferred in the present invention, and in particular, those obtained by polymerizing a monomer containing at least a (meth) acrylic acid ester as a monomer component. preferable.
More specifically, a homopolymer of (meth) acrylic acid ester, a copolymer of two or more different (meth) acrylic acid ester monomers, or a copolymer of (meth) acrylic acid ester and other monomers Is preferred.

The thermoplastic resin preferably has a weight average molecular weight in the range of 90,000 to 120,000. When the weight average molecular weight is within this range, the formability after crosslinking and curing to form the surface protective layer, the surface wear resistance, and the scratch resistance can all be obtained at a high level.
Here, the weight average molecular weight is a value in terms of polystyrene measured by gel permeation chromatography (GPC). The solvent used here can be appropriately selected from those usually used, and examples thereof include tetrahydrofuran (THF) and N-methyl-2-pyrrolidinone (NMP).

  The polydispersity (weight average molecular weight Mw / number average molecular weight Mn) of the thermoplastic resin is preferably in the range of 1.1 to 3.0. If the polydispersity is within this range, it is possible to obtain a high level of moldability, surface abrasion resistance, and scratch resistance after crosslinking and curing to form a surface protective layer. From the above points, the polydispersity of the (meth) acrylic resin is preferably in the range of 1.5 to 2.5.

In the resin composition for forming the surface protective layer in the present invention, the cured product obtained by the following method has a tensile elastic modulus of more than 100 MPa and less than 1000 MPa. When the tensile modulus of the cured product is 100 MPa or less, sufficient surface wear resistance, scratch resistance, solvent resistance, contamination resistance, and the like cannot be obtained. On the other hand, when the tensile modulus of the cured product is 1000 MPa or more, the flexibility of the coating film is insufficient, and the coating film is cracked against bending and impact. From the above viewpoint, the tensile elastic modulus is preferably 500 to 900 MPa, and more preferably 700 to 800 MPa.
[Measurement method of tensile modulus]
A resin composition for forming a surface protective layer is applied on a biaxially stretched polyester film so that the thickness after curing is 20 μm, and the coating film cured by irradiating with ionizing radiation is applied from the polyester film. Peel off to make a sample. The sample is measured at a tensile speed of 50 mm / min using a tensile tester (for example, Tensilon Universal Tester “RTC-1250A” manufactured by A & D Corporation).

  Moreover, various additives can be mix | blended with the resin composition which comprises the surface protective layer in this invention according to the desired physical property of the cured resin layer obtained. In particular, it is preferable to contain a lubricant in order to further improve the surface scratch resistance and the like. Examples of the lubricant include synthetic wax, petroleum wax, animal-derived wax, plant-derived wax and the like, reactive silicone, fluorine-based lubricant, and the like.

Synthetic waxes are produced by chemically synthesizing hydrocarbon compounds, and are broadly classified into hydrocarbon synthetic waxes and non-hydrocarbon synthetic waxes such as higher fatty acid esters and fatty acid amides.
Examples of the hydrocarbon-based synthetic wax include polyethylene wax produced by polymerization of ethylene and thermal decomposition of polyethylene, and Fischer-Tropsch wax produced by reacting carbon monoxide and hydrogen.

  Petroleum wax is a paraffin wax [separated and extracted hydrocarbons with good crystallinity from the portion of crude oil distilled under reduced pressure, and is mainly composed of linear hydrocarbons (normal paraffin) and has a large melting point. Is about 40 ° C to 70 ° C. ] And microcrystalline wax [was mainly taken from the vacuum distillation residue of crude oil, and the constituent hydrocarbons are mostly branched hydrocarbons (isoparaffins) and saturated cyclic hydrocarbons (cycloparaffins). For this reason, the crystal | crystallization is small compared with paraffin wax. Also, the molecular weight is large, and therefore the melting point is as high as about 60 ° C to 90 ° C. ] Etc. are mentioned.

Examples of animal-derived waxes include beeswax, wool wax, spermaceti, shellac wax, and chiwax wax.
Examples of plant-derived waxes include carnauba wax, candelilla wax, wood wax, and rice wax (rice bran wax).

Of the various waxes described above, synthetic waxes are preferred, and polyethylene wax is particularly preferred. Polyethylene wax has a very low coefficient of friction and has high toughness. Therefore, the effect of protecting the surface of the surface protective layer and facilitating wiping even when fingerprints are attached is high.
The melting point of the wax is preferably 90 to 140 ° C. The average particle diameter of the wax is not particularly limited, but is preferably set as appropriate according to the film thickness of the surface protective layer. In this use, 1-30 micrometers is preferable and 1-20 micrometers is especially preferable.

In the present invention, it is also a preferred embodiment to use reactive silicone as a lubricant. Here, the reactive silicone refers to a modified silicone oil in which an organic group is introduced into a side chain and / or a terminal, and the organic group is reactive. This reactive silicone reacts with the resin when the ionizing radiation curable resin composition is cured, and bonds and integrates with the resin. Therefore, the reactive silicone slips on the surface of the decorative sheet of the present invention without bleeding out on the surface. It is particularly preferable because it imparts the property and improves the scratch resistance and the like.
In addition, unlike reactive waxes, the reactive silicone does not affect the smoothness and gloss of the surface layer even when blended, and is particularly suitable for expressing a specular and high gloss design.
The types of reactive silicone include modified silicone oil side chain type, modified silicone oil both end type, and modified silicone oil side chain both end type, depending on the organic group to be introduced, amino-modified, epoxy-modified, mercapto-modified. , Carboxyl modification, carbinol modification, phenol modification, methacryl modification, and different functional group modification.
As content of reactive silicone, the range of 0.1-50 mass parts is preferable with respect to 100 mass parts of ionizing radiation-curable resins. When the amount is 0.1 parts by mass or more, sufficient lubricity can be imparted to the surface. When the amount is 50 parts by mass or less, no repelling occurs during coating, and the coating surface is not roughened. In addition, the paint stability can be improved. From the above viewpoint, the content is more preferably in the range of 0.5 to 10 parts by mass.

  Examples of the fluorine-based lubricant include polytetrafluoroethylene, polychlorotrifluoroethylene, polyhexafluoropropylene, polyvinylidene fluoride, polyvinyl fluoride, tetrafluoroethylene-hexafluoropropylene binary copolymer, tetrafluoroethylene. -Hexafluoropropylene-vinylidene fluoride terpolymer.

In the resin composition constituting the surface protective layer in the present invention, the expression of design can be freely adjusted from high gloss to low gloss by adjusting the blending amount of the matting agent. Can be improved. Specifically, when a low gloss pattern ink layer is provided, a matte agent is added to the surface protective layer to combine with the matte effect of the low gloss pattern ink layer to express further low gloss. (See FIG. 1). On the other hand, in the case where a low gloss pattern ink layer is not provided, it is possible to express a design with high gloss and excellent smoothness and specularity by not adding a matting agent to the surface protective layer or by reducing the amount to be added. Yes (see FIG. 2).
The matting agent is appropriately selected from, for example, silica, talc, clay, barium sulfate, barium carbonate, calcium sulfate, calcium carbonate, magnesium carbonate and the like. Of these, silica, which is a material having a high degree of freedom in material design such as oil absorption, particle size, pore volume, etc., and excellent in designability, whiteness, and coating stability as an ink, is preferred. Is preferred.
The particle size of the matting agent is 0.1 to 20 μm, preferably 1 to 10 μm.
The content of these matting agents in the resin composition constituting the surface protective layer is preferably in the range of 1 to 80% by mass.

Examples of other additives include a weather resistance improver, an abrasion resistance improver, a polymerization inhibitor, a crosslinking agent, an infrared absorber, an antistatic agent, an adhesion improver, a leveling agent, a thixotropic agent, and a coupling agent. , Plasticizers, antifoaming agents, fillers, solvents, colorants and the like.
Here, as the weather resistance improving agent, an ultraviolet absorber or a light stabilizer can be used. The ultraviolet absorber may be either inorganic or organic, and as the inorganic ultraviolet absorber, titanium dioxide, cerium oxide, zinc oxide or the like having an average particle diameter of about 5 to 120 nm can be preferably used. Examples of organic ultraviolet absorbers include benzotriazole, benzophenone, benzoate, triazine, and cyanoacrylate. For example, as benzotriazole, specifically, 2- (2-hydroxy- 5-methylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-tert-amylphenyl) benzotriazole, polyethylene glycol 3- [3- (benzotriazol-2-yl) -5-tert- Butyl-4-hydroxyphenyl] propionic acid ester and the like. On the other hand, examples of the light stabilizer include hindered amines, specifically 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2′-n-butylmalonate bis (1,2,2). , 6,6-pentamethyl-4-piperidyl), bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl)- 1,2,3,4-butanetetracarboxylate and the like. Further, as the ultraviolet absorber or light stabilizer, a reactive ultraviolet absorber or light stabilizer having a polymerizable group such as a (meth) acryloyl group in the molecule can be used.

Examples of the wear resistance improver include, for inorganic substances, spherical particles such as α-alumina, silica, kaolinite, iron oxide, diamond, and silicon carbide. Examples of the particle shape include a sphere, an ellipsoid, a polyhedron, a scale shape, and the like. Although there is no particular limitation, a spherical shape is preferable. Organic materials include synthetic resin beads such as cross-linked acrylic resin and polycarbonate resin. The particle size is preferably about 30 to 200% of the normal film thickness. Among these, spherical α-alumina is particularly preferable because it has high hardness and a large effect on improving wear resistance, and it is relatively easy to obtain spherical particles.
Examples of the polymerization inhibitor include hydroquinone, p-benzoquinone, hydroquinone monomethyl ether, pyrogallol, and t-butylcatechol. Examples of the crosslinking agent include a polyisocyanate compound, an epoxy compound, a metal chelate compound, an aziridine compound, and an oxazoline compound. Used.
As the filler, for example, barium sulfate, talc, clay, calcium carbonate, aluminum hydroxide and the like are used.
Examples of the colorant include known coloring pigments such as quinacridone red, isoindolinone yellow, phthalocyanine blue, phthalocyanine green, titanium oxide, and carbon black.
As the infrared absorber, for example, a dithiol metal complex, a phthalocyanine compound, a diimmonium compound, or the like is used.

Formation of the surface protective layer 14 can be obtained by preparing a coating liquid containing the above-mentioned resin composition for forming a surface protective layer, applying it, and crosslinking and curing it. In addition, the viscosity of a coating liquid should just be a viscosity which can form a non-hardened resin layer on the surface of a base material by the below-mentioned coating system, and there is no restriction | limiting in particular.
In the present invention, the prepared coating liquid is applied to the surface of the support 11 so that the thickness after curing is 1 to 30 μm, such as gravure coating, bar coating, roll coating, reverse roll coating, comma coating, etc. The known method, preferably gravure coating, is applied to form an uncured resin layer.

In the present invention, the uncured resin layer formed as described above is irradiated with ionizing radiation such as an electron beam and ultraviolet rays to cure the uncured resin layer. 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, but the uncured resin layer is usually cured at an acceleration voltage of about 70 to 300 kV. preferable.
In addition, in electron beam irradiation, since the transmission capability increases as the acceleration voltage is higher, when using a base material that deteriorates due to the electron beam as the support 11, the transmission depth of the electron beam and the thickness of the resin layer are By selecting the accelerating voltage so as to be substantially equal, it is possible to suppress the irradiation of the extra electron beam onto the support 11 and to minimize the deterioration of the base material due to the extra electron beam. .
The irradiation dose is preferably such that 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 100 kGy (1 to 10 Mrad).
Further, the electron beam source is not particularly limited. For example, various electron beam accelerators such as a cockroft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type. Can be used.

  When ultraviolet rays are used as the ionizing radiation, those containing ultraviolet rays having a wavelength of 190 to 380 nm are emitted. There is no restriction | limiting in particular as an ultraviolet-ray source, For example, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a carbon arc lamp, etc. are used.

  The cured resin layer thus formed has various functions by adding various additives, for example, a so-called hard coat function, anti-fogging coat function, and anti-fouling coat having high hardness and scratch resistance. A function, an antiglare coating function, an antireflection coating function, an ultraviolet shielding coating function, an infrared shielding coating function, and the like can also be imparted.

  In this invention, it is preferable that the thickness after hardening of the surface protective layer 14 is 1-30 micrometers. When the thickness of the surface protective layer 14 after curing is 1 μm or more, sufficient physical properties as a protective layer such as stain resistance, scratch resistance, and weather resistance can be obtained, and unevenness of the support, the pattern layer, and the primer layer Does not appear on the surface. Accordingly, the smoothness of the surface is ensured, and a high gloss feeling and sufficient specularity are obtained. On the other hand, when the thickness is 30 μm or less, the effect of the low gloss ink layer is sufficiently exhibited and the moldability becomes good. From the viewpoint of ensuring better moldability and obtaining sufficient scratch resistance and weather resistance, the thickness of the surface protective layer 14 after curing is more preferably in the range of 2 to 20 μm, and more preferably in the range of 3 to 10 μm. Particularly preferred.

In addition, the decorative sheet of the present invention must have a surface static friction coefficient (μs) of 1.0 or less. If the static friction coefficient (μs) is 1.0 or less, a decorative sheet having excellent surface scratch resistance and scratch resistance can be obtained. From the above viewpoint, the coefficient of static friction (μs) is more preferably 0.5 or less. As a method of setting the static friction coefficient (μs) to 1.0 or less, and further 0.5 or less, the above-mentioned reactive silicone acrylate, wax, fluorine-based lubricant or the like is added to the surface protective layer forming resin composition. There is a method of adding.
The coefficient of static friction (μs) was measured using a “friction measuring machine AN” manufactured by Toyo Seiki Co., Ltd. at an inclination speed of 1 degree / second.

Furthermore, the decorative sheet of the present invention preferably has a tensile elongation of 50% or more in a tensile test based on JIS K 7127. The higher the tensile elongation is, the better the moldability is. However, if the tensile elongation is 50% or more, the surface protective layer is not cracked during vacuum forming with a commonly used vacuum forming die. The tensile elongation is more preferably 150% or more. When the tensile elongation is 150% or more, it follows a complicated shape or a shape with large deformation, and no cracks are generated in the surface protective layer.
The measurement conditions for the tensile test were as follows: a test piece having a width of 25 mm and a length of 120 mm was used, the tensile speed was 1000 mm / min, the distance between chucks was 80 mm, the distance between marked lines was 50 mm, and the temperature was 160 ° C. It evaluates by the tensile elongation at the time of entering.

  The decorative sheet of the present invention is used in an insert molding method. In the insert molding method, in the vacuum forming process, the decorative sheet of the present invention is vacuum formed into a surface shape of the molded product in advance (off-line pre-molding) with a vacuum forming die, and then the excess portion is trimmed as necessary to form a molded sheet. Get. 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 and solidified, and the decorative sheet is integrated on the outer surface of the resin molding simultaneously with the injection molding. To produce decorative resin molded products.

  As the injection resin, a resin corresponding to the application is used, and a thermoplastic resin such as a polyolefin resin such as polyethylene or polypropylene, an ABS resin, a styrene resin, a polycarbonate resin, an acrylic resin, or a vinyl chloride resin is representative. In addition, thermosetting resins such as urethane resins and epoxy resins can be used depending on applications.

The decorated resin molded body produced as described above does not crack in the surface protective layer during the molding process, and its surface has high wear resistance and scratch resistance. Moreover, solvent resistance and chemical resistance are high with respect to the acrylic film conventionally used as a surface protective layer. Furthermore, in the production method of the present invention, the surface protective layer is completely cured at the production stage of the decorative sheet, and therefore a step of crosslinking and curing the surface protective layer after producing the decorative resin molded body is unnecessary.
The decorative resin molded body of the present invention is, for example, an interior material or exterior material of a vehicle such as an automobile, a construction member such as a skirting board or a fringe, a fitting such as a window frame or a door frame, a building such as a wall, a floor, or a ceiling. It is suitable for applications such as interior materials for products, housings and containers for household electrical appliances such as television receivers and air conditioners.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by this example.
Evaluation method (1) Coefficient of static friction (tan θ)
About the decorative sheet and the decorative resin molded product obtained in each Example and Comparative Example, using a “friction measuring machine AN” manufactured by Toyo Seiki Co., Ltd., the surface static friction coefficient was measured at an inclination speed of 1 degree / second. did.
(2) Tensile modulus Measured by the method described in the specification text.
(3) Tensile elongation Measured by the method described in the text of the specification.
(4) Formability A (coating shape conformability of coating film)
About the decorative sheet obtained by each Example and the comparative example, it vacuum-formed by the method shown below, and evaluated by the external appearance after shaping | molding. The evaluation criteria are as follows.
◯: No cracking or whitening of the coating film was observed on the surface protective layer, and the shape of the mold was followed well.
X: The coating film cracking and whitening were observed in the surface protective layer without following the shape of the mold.
<Vacuum forming>
The decorative sheet is heated to 160 ° C. with an infrared heater and softened. Next, vacuum forming is performed using a vacuum forming die (maximum draw ratio is 150 times) to form the internal shape of the die. The decorative sheet is released from the mold, and unnecessary parts are trimmed to obtain a molded sheet.

(5) Formability B (shape retention after vacuum forming)
The sheet vacuum-formed by the above method was allowed to stand for 24 hours, and the shape was compared with the sheet immediately after forming. The evaluation criteria are as follows.
○: The shape immediately after molding and after standing for 24 hours matched.
X: The shape immediately after molding and after standing for 24 hours was inconsistent.

(6) Scratch resistance The decorative sheet produced in each of the examples and comparative examples was subjected to a load using Kanakin No. 3 as a white cotton cloth for friction using a “Gakushin type friction fastness tester” manufactured by Tester Sangyo Co., Ltd. The test piece after 2000 reciprocations at 500 gf was evaluated. The evaluation criteria are as follows.
○: No noticeable scratches on appearance △: Minor scratches on the surface ×: Significant scratches on the surface

(7) Pencil hardness test Insert molding was performed using the decorative sheets produced in each of the examples and comparative examples, and the obtained molded product was used using an "electric pencil scratch hardness tester" manufactured by Yasuda Seiki Seisakusho. Using a “uni pencil” manufactured by Mitsubishi Pencil Co., Ltd., the load was 750 gf and the test speed was 1 mm / s.

(8) Designability Insert molding was performed using the decorative sheets produced in each Example and Comparative Example, and the designability of the surface of the obtained molded product was evaluated visually. The evaluation criteria are divided into those having low gloss design properties (Examples 1 to 6 and all comparative examples) and those having high gloss design properties (Examples 7 and 8). Evaluated by criteria.
Those having low gloss design properties ◎; The conduit portion was recognized as a concave portion, and further, the texture of the wood grain and the conduit portion were synchronized, so the texture of the wood grain was obtained, and the design property was extremely high.
Δ: The conduit portion was recognized as a concave portion, but the texture of the grain, in which the pattern of the grain and the conduit portion were synchronized, was not obtained.
X: The design was flat and inferior in design.
Those having high glossy design properties ◎; excellent in smoothness and specularity, and extremely high in design properties.
X: Smoothness and specularity were poor, and the design was inferior.

Example 1
An electron beam curable resin (hereinafter referred to as “EB”) composed of 60% by mass of bifunctional urethane acrylate (EB-1, weight average molecular weight; 2000) and 40% by mass of bifunctional polyester acrylate (EB-2, weight average molecular weight; 10,000). 2 parts by weight of reactive silicone and 10 parts by weight of silica having an average particle size of 3.0 μm as a matting agent are added to 100 parts by weight of resin), and an electron beam curable resin composition for forming a surface protective layer Got. The tensile modulus of the EB resin was 750 MPa.
Next, a sheet made of ABS resin (ABS-1, flexural modulus: 2000 MPa, thickness: 400 μm) is used as a support, and a two-component curable urethane ink is used on the surface of the sheet, and the grain is printed by gravure printing. A pattern layer of patterns was formed. Next, a two-component curable urethane resin containing an acrylic / urethane block copolymer as a main component and an isocyanate as a curing agent was applied onto the pattern layer to form a transparent primer layer having a thickness of 2 μm. On the primer layer, 10 parts by mass of silica having an average particle size of 3.0 μm is blended with 100 parts by mass of a polyester urethane printing ink having a number average molecular weight of 3,000 and a glass transition temperature (Tg) of −62.8 ° C. Using the ink thus obtained, coating was performed by gravure printing so as to synchronize with the grain pattern conduit portion of the above pattern layer, and a low gloss pattern ink layer having a thickness of 1.0 μm was obtained.
The electron beam curable resin composition for forming a surface protective layer was applied onto the low gloss pattern ink layer so that the thickness after curing was 6 μm. This uncured resin layer was irradiated with an electron beam having an acceleration voltage of 165 kV and an irradiation dose of 50 kGy (5 Mrad) to cure the electron beam curable resin composition to obtain a decorative sheet.
The decorative sheet was evaluated by the above method. The evaluation results are shown in Table 1.

Example 2
In Example 1, a decorative sheet was obtained in the same manner as in Example 1 except that the content of the reactive silicone was 1 part by mass with respect to 100 parts by mass of the EB resin. The tensile elastic modulus of the EB resin was 750 MPa. The results evaluated in the same manner as in Example 1 are shown in Table 1.

Example 3
In Example 1, a decorative sheet was obtained in the same manner as in Example 1 except that the contents of EB-1 and EB-2 in the EB resin were 35% by mass and 65% by mass, respectively. The results evaluated in the same manner as in Example 1 are shown in Table 1. The tensile modulus of the EB resin was 630 MPa.

Example 4
In Example 1, a decorative sheet was obtained in the same manner as in Example 1, except that bifunctional urethane acrylate (EB-3, weight average molecular weight; 10,000) was used as the EB resin. The results evaluated in the same manner as in Example 1 are shown in Table 1. The tensile modulus of the EB resin was 450 MPa.

Example 5
In Example 1, the EB resin is composed of 40% by mass of bifunctional urethane acrylate (EB-1, weight average molecular weight; 2000) and 60% by mass of bifunctional urethane acrylate (EB-3, weight average molecular weight; 10,000). A decorative sheet was obtained in the same manner as in Example 1 except that one was used. The results evaluated in the same manner as in Example 1 are shown in Table 1. The tensile modulus of the EB resin was 520 MPa.

Example 6
In Example 1, 40% by mass of tetrafunctional urethane acrylate (EB-4, weight average molecular weight; 4000) and polymethyl methacrylate (PMMA) which is a thermoplastic resin as an electron beam curable resin composition for forming a surface protective layer. , Weight average molecular weight; 68000) 2 parts by mass of reactive silicone and 10 parts by mass of silica having an average particle size of 3.0 μm as a matting agent are used for 100 parts by mass of a resin composition comprising 60% by mass. A decorative sheet was obtained in the same manner as in Example 1 except that. The results evaluated in the same manner as in Example 1 are shown in Table 1. The tensile modulus of the resin composition was 700 MPa.

Example 7
In Example 1, an electron beam curable resin composition for forming a surface protective layer was formed by applying a surface protective layer forming electron beam curable resin composition on a transparent primer layer without providing a low gloss pattern ink layer. A decorative sheet was obtained in the same manner as in Example 1 except that the material did not contain a matting agent. The tensile modulus of the EB resin was 750 MPa.
The decorative sheet was evaluated by the above method. The evaluation results are shown in Table 1.

Example 8
In Example 3, the low-gloss pattern ink layer was not provided, and the electron beam curable resin composition for forming the surface protective layer was applied on the transparent primer layer, and the electron beam curable resin composition for forming the surface protective layer. A decorative sheet was obtained in the same manner as in Example 3 except that the product did not contain a matting agent. The tensile modulus of the EB resin was 630 MPa.
The decorative sheet was evaluated by the above method. The evaluation results are shown in Table 1.

Comparative Example 1
In Example 1, a decorative sheet was obtained in the same manner as in Example 1 except that no reactive silicone was added. The results evaluated in the same manner as in Example 1 are shown in Table 1.

Comparative Example 2
In Example 1, a decorative sheet was obtained in the same manner as in Example 1 except that a sheet made of ABS resin (ABS-2, flexural modulus: 1200 MPa, thickness: 400 μm) was used as the support. . The results evaluated in the same manner as in Example 1 are shown in Table 1.

Comparative Example 3
In Example 2, a decorative sheet was obtained in the same manner as in Example 2 except that a sheet made of ABS resin (ABS-2, flexural modulus: 1200 MPa, thickness: 400 μm) was used as the support. . The results evaluated in the same manner as in Example 1 are shown in Table 1.

Comparative Example 4
Example 1 is the same as Example 1 except that no reactive silicone is added and a sheet made of ABS resin (ABS-2, flexural modulus: 1200 MPa, thickness: 400 μm) is used as the support. Thus, a decorative sheet was obtained. The results evaluated in the same manner as in Example 1 are shown in Table 1.

Comparative Example 5
In Example 3, a decorative sheet was obtained in the same manner as Example 3 except that no reactive silicone was added. The results evaluated in the same manner as in Example 1 are shown in Table 1.

Comparative Example 6
In Example 3, a decorative sheet was obtained in the same manner as in Example 3 except that a sheet made of ABS resin (ABS-2, flexural modulus: 1200 MPa, thickness: 400 μm) was used as the support. . The results evaluated in the same manner as in Example 1 are shown in Table 1.

Comparative Example 7
Example 3 was the same as Example 3 except that no reactive silicone was added and a sheet made of ABS resin (ABS-2, flexural modulus: 1200 MPa, thickness: 400 μm) was used as the support. Thus, a decorative sheet was obtained. The results evaluated in the same manner as in Example 1 are shown in Table 1.

Comparative Example 8
In Example 1, a decorative sheet was obtained in the same manner as in Example 1 except that only EB-2 was used as the EB resin. The results evaluated in the same manner as in Example 1 are shown in Table 1. The tensile modulus of the EB resin was 100 MPa.

Comparative Example 9
In Example 1, a decorative sheet was obtained in the same manner as in Example 1 except that only EB-1 was used as the EB resin. The results evaluated in the same manner as in Example 1 are shown in Table 1. The tensile modulus of the EB resin was 1000 MPa.

Reference example 1
In the same manner as in Example 1, an electron beam curable resin composition was obtained.
Next, a 60 μm thick transparent polypropylene film subjected to double-sided corona discharge treatment is used as the base material, and a two-part curable urethane ink is used on the back of the film to form a woodgrain pattern layer by gravure printing did. Next, a two-part curable urethane-based resin having an acrylic / urethane block copolymer as a main component and isocyanate added as a curing agent is applied to the surface where no pattern layer is applied, and a transparent primer layer having a thickness of 2 μm is formed. Formed. Obtained by blending 10 parts by mass of silica having an average particle size of 3.0 μm with 100 parts by mass of polyester urethane printing ink having a number average molecular weight of 3000 and a glass transition temperature (Tg) of −62.8 ° C. The ink layer was coated by gravure printing so as to synchronize with the grain pattern conduit portion of the pattern layer to obtain a low gloss pattern ink layer having a thickness of 1.0 μm.
On the low gloss pattern ink layer, the electron beam curable resin composition for forming a surface protective layer was applied such that the thickness after curing was 3 μm. This uncured resin layer is irradiated with an electron beam with an acceleration voltage of 165 kV and an irradiation dose of 50 kGy (5 Mrad) to cure the electron beam curable resin composition, and then two liquids with a film thickness of 10 μm are formed on the pattern layer side of the sheet. A curable urethane resin adhesive was applied and laminated with a covert colored ABS resin sheet having a film thickness of 400 μm, which was a backer film, to obtain a decorative sheet. The results evaluated in the same manner as in Example 1 are shown in Table 1.

The decorative sheet in which the surface protective layer is formed using the resin composition for forming the surface protective layer of the present invention is a rapid temperature from a heating temperature of about 160 ° C. to a temperature at the time of contact with the mold in a normal insert molding method. Cracks and cracks do not occur even under conditions of lowering, rapid stretching speed, and high degree of stretching. In addition, the design was high, and the texture was particularly imparted to the wood grain pattern.
Furthermore, it was confirmed that the moldability of the decorative resin molded product thus produced was excellent in moldability and high abrasion resistance and scratch resistance.

  The surface of the decorative sheet of the present invention has high wear resistance and scratch resistance, and has good moldability and is free from cracks. Therefore, the decorative resin molded body manufactured using the decorative sheet of the present invention does not crack in the surface protective layer during the molding process, and the surface has high wear resistance and scratch resistance. Moreover, according to the manufacturing method of this invention, since a surface protective layer is fully hardened in the manufacture stage of a decorating sheet, the process of bridge | crosslinking and hardening a surface protective layer after manufacturing a decorating resin molding is unnecessary. Furthermore, it is a decorative sheet with high design properties, such as being able to express gloss differences and irregularities in synchronism with the pattern layer, and giving a texture.

10. Decorative sheet Support 12. Pattern layer 13. Low gloss pattern ink layer 14. Surface protective layer 15. Low gloss area 16. Convex shape

Claims (9)

A decorative sheet for insert molding formed by laminating at least a surface protective layer on a support made of ABS resin, wherein the support has a bending elastic modulus of 1500 to 3000 MPa, and the thickness of the support is 100 to 500 μm, the surface protective layer is obtained by crosslinking and curing the ionizing radiation curable resin composition, and the tensile elastic modulus of the ionizing radiation curable resin composition measured by the following method is more than 100 MPa to less than 1000 MPa, and The decorative sheet for insert molding, wherein the static friction coefficient of the surface is 1.0 or less.
(Measurement method of tensile modulus)
A resin composition for forming a surface protective layer is applied on a biaxially stretched polyester film so that the thickness after curing is 20 μm, and the coating film cured by irradiating with ionizing radiation is applied from the polyester film. Peel off to make a sample. The sample is measured at a tensile speed of 50 mm / min using a tensile tester.   The decorative sheet for insert molding according to claim 1, wherein the surface protective layer has a thickness of 1 to 30 µm. The decorative sheet for insert molding according to claim 1 or 2, wherein a tensile elongation in a tensile test under the following measurement conditions based on JIS K 7127 is 50% or more.
(Measurement conditions) Using a test piece having a width of 25 mm and a length of 120 mm, tensile elongation when a crack occurs in the surface protective layer under the conditions of a tensile speed of 1000 mm / min, a distance between chucks of 80 mm, a distance between marked lines of 50 mm, and a temperature of 160 ° C. Measure the degree.   The decorative sheet for insert molding according to any one of 1 to 3, wherein a low gloss pattern ink layer is laminated between the support and the surface protective layer.   The decorative sheet for insert molding according to any one of claims 1 to 4, further comprising a pattern layer between the support and the low gloss pattern ink layer.   The decorative sheet for insert molding according to any one of claims 1 to 5, wherein the ionizing radiation curable resin is an electron beam curable resin.   The decorative sheet for insert molding according to any one of claims 1 to 6, wherein the ionizing radiation curable resin composition contains reactive silicone.   A vacuum forming step in which the decorative sheet for insert molding according to any one of claims 1 to 7 is previously formed into a three-dimensional shape by a vacuum forming die, a step of trimming excess portions to obtain a formed sheet, and injecting the formed sheet A method for producing a decorative resin molded article, comprising the steps of inserting into a mold, closing the injection mold, and injecting a resin in a fluid state into the mold to integrate the resin and the molded sheet.   A decorative resin molded product produced by the production method according to claim 8.

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