JP2012041480A - Ink composition and decorative sheet using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition which imparts, to a decorative sheet, excellent production efficiency such that high hardness is imparted to a decorative molded article, moldability required for forming a molded article having a more complicated shape is imparted, and a tack-free hardcoat layer-forming layer can be formed merely by thermal drying, if necessary; to provide a decorative sheet using the ink composition; and to provide a decorative molded article using the decorative sheet.SOLUTION: The ink composition 13 comprises a polyfunctional radical-polymerizable prepolymer having at least one ionizing-radiation-curable functional group A selected from a vinyl group, (meth)acryloyl group and allyl group, and having a weight-average molecular weight of less than 50,000; a reactive inorganic particle having an ionizing-radiation-curable functional group B on the surface thereof; and a polyfunctional isocyanate compound. The content of the prepolymer solid content to sum total of the prepolymer solid content and the reactive inorganic particle is 15-75 mass%. There are also disclosed a decorative sheet 10 using the composition, and a decorative molded article using the sheet.

Description

  The present invention relates to an ink composition and a decorative sheet using the same.

Conventionally, an injection molding simultaneous decorating method is used for decorating a resin molded body having a complicated surface shape such as a three-dimensional curved surface. In the injection molding simultaneous decoration method, the decorative sheet inserted into the mold at the time of injection molding is integrated with the molten injection resin injected and injected into the cavity to decorate the surface of the resin molded body Generally, it is roughly classified into an injection molding simultaneous laminate decoration method and an injection molding simultaneous transfer decoration method depending on the difference in the configuration of the decorative sheet integrated with the resin molded body.
In the injection molding simultaneous transfer decoration method, after the decorative sheet is closely attached to the inner surface of the mold and clamped, the molten injection resin is injected into the cavity to integrate the decorative sheet and the injection resin, After the decorative molded product is cooled and taken out from the mold, the decorative molded product to which the transfer layer is transferred can be obtained by peeling the base film.

  The decorative molded products thus obtained include notebooks including mobile PCs that can be carried everyday, for example, along with the expansion of the PC market in recent years, in addition to the fields of household appliances and automobile interiors that have been used in the past. Use in the field of personal computers, automobile exteriors, and cellular phones are also attracting attention. In these fields, the decorative sheet is required to have surface properties such as high hardness, which are excellent in the decorative molded product, and at the same time, formability capable of obtaining a molded product with a more complicated shape is required.

  In order to satisfy such requirements, a transfer material having a protective layer using an active energy ray-curable resin composition containing a low molecular weight polymer and a polyfunctional isocyanate has been proposed (for example, see Patent Document 1). However, it is difficult for the protective layer to be tack-free, and in order to achieve a tack-free state, baking at a high temperature of 150 ° C. or long-time heat treatment is required, and more stringent requirements for surface properties such as high hardness are required. There was a problem that could not be handled.

  For the purpose of obtaining surface properties such as high hardness, a transfer material having a protective layer containing a low molecular weight polymer, a curing agent, and colloidal silica particles has been proposed (for example, see Patent Document 2). However, it is not sufficient for the stricter requirement of pencil hardness of H or higher, and when the decorative sheet is rolled up, there is a case where blocking (setback) may occur, or for a molded product with a more complicated shape As a result, the protective layer may be whitened or paint cracks may occur. Surface properties such as high hardness and anti-blocking and moldability are contradictory performances, and there is no such thing that ensures these contradictory performances at a high level.

Japanese Patent No. 3233595 JP 2009-137219 A

  Under such circumstances, the present invention imparts excellent hardness to a decorative molded product and at the same time imparts moldability to obtain a molded product having a more complicated shape, and also requires a hard coat layer forming layer. Ink composition that imparts excellent production efficiency to a decorative sheet that can be tack-free only by thermal drying, a decorative sheet using the ink composition, and a decoration using the decorative sheet It is an object to provide a molded product.

  As a result of intensive studies to achieve the above problems, the present inventor has found that the problems can be solved by the following invention. That is, the present invention provides the following ink composition, a decorative sheet using the same, a method for manufacturing a decorative molded product using the same, and a decorative molded product obtained by the manufacturing method.

1. A polyfunctional radical polymerization prepolymer having at least one selected from a vinyl group, a (meth) acryloyl group and an allyl group as the ionizing radiation curable functional group A, and having a weight average molecular weight of less than 50,000, ionizing radiation curable on the surface Reactive inorganic particles having a functional group B and a polyfunctional isocyanate compound, the solid content of the prepolymer with respect to the total of the solid content of the prepolymer and the reactive inorganic particles is 15 to 75% by mass An ink composition.
2. A decorative sheet having at least a release layer and a hard coat layer forming layer in order on one side of a substrate film, wherein the hard coat layer forming layer is formed using the ink composition described in 1 above. A decorative sheet.
3. The manufacturing method of the decorative molded product which has the following process (1) -process (5).
Step (1) Disposing the decorative sheet described in 2 above in the injection mold (2) Injecting molten resin into the cavity, cooling and solidifying, and molding the resin molded body and the decorative sheet (3) Process step for removing the molded body in which the resin molded body and the decorative sheet are integrated from the mold (4) Process step for peeling the base film of the decorative sheet from the molded body ( 5) Hard coat layer forming step of curing the hard coat layer forming layer provided on the molded body using ionizing radiation. A decorative molded product obtained by the production method described in 3 above.

  According to the present invention, the decorative molded product is imparted with excellent high hardness, and at the same time, it is imparted with moldability to obtain a molded product with a more complicated shape, and the hard coat layer forming layer is heat-dried as necessary. Provided is an ink composition that imparts excellent production efficiency to a decorative sheet, which can be tack-free only, a decorative sheet using the ink composition, and a decorative molded product using the decorative sheet be able to.

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 decorative molded product of this invention.

[Ink composition]
The ink composition of the present invention has a polyfunctional radical polymerization type prepolymer having a weight average molecular weight of less than 50000 and having at least one selected from a vinyl group, a (meth) acryloyl group and an allyl group as the ionizing radiation curable functional group A. Polymer, reactive inorganic particles having ionizing radiation curable functional group B on the surface, and polyfunctional isocyanate compound, the solid content of the prepolymer with respect to the total of the solid content of the prepolymer and the reactive inorganic particles It is a composition whose amount is 15 to 75% by mass.

<Polyfunctional radical polymerization type prepolymer having ionizing radiation curable functional group A>
Ionizing radiation curable is one having an energy quantum that can crosslink and polymerize molecules in an electromagnetic wave or charged particle beam, that is, crosslinked by causing a polymerization reaction upon excitation by irradiation with ultraviolet rays or electron beams, It is the ability to cure. The ionizing radiation curable functional group is a functional group capable of expressing the ionizing radiation curable property, and has an ethylenically unsaturated bond such as vinyl group, (meth) acryloyl group and allyl group in the present invention. It is a functional group.

  The polyfunctional radical polymerization type prepolymer is not particularly limited as long as it is a prepolymer having the ionizing radiation curable functional group A. For example, acrylic (meth) acrylate prepolymer, urethane (meth) acrylate prepolymer, polyester Prepolymers such as (meth) acrylate-based prepolymers, epoxy (meth) acrylate-based prepolymers, and polyether (meth) acrylate-based prepolymers are preferred, and acrylic (meth) acrylate-based prepolymers are particularly preferable. In the present invention, these prepolymers may be used alone or in combination.

Here, acrylic (meth) acrylate-based prepolymers are (meth) acrylic acid alkyl ester and copolymerizable with glycidyl (meth) acrylate, (meth) acrylamide, (meth) acrylonitrile, (meth) acrylic acid It is a prepolymer formed by copolymerizing a functional group-containing (meth) acrylic compound such as hydroxyalkyl or a carboxylic acid such as (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid.
The urethane (meth) acrylate-based prepolymer can be obtained, for example, by esterifying a polyurethane prepolymer obtained by reaction of polyether polyol or polyester polyol with polyisocyanate with (meth) acrylic acid.
As the polyester (meth) acrylate-based prepolymer, for example, by esterifying hydroxyl groups of a polyester prepolymer 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 the terminal hydroxyl group of a prepolymer obtained by adding an alkylene oxide to a polyvalent carboxylic acid with (meth) acrylic acid.
The epoxy (meth) acrylate-based prepolymer can be obtained, for example, by esterifying the oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin with (meth) acrylic acid. Alternatively, a carboxyl-modified epoxy (meth) acrylate prepolymer obtained by partially modifying the epoxy (meth) acrylate prepolymer with a dibasic carboxylic acid anhydride can also be used.
The polyether (meth) acrylate polymer can be obtained by esterifying the hydroxyl group of the polyether polyol with (meth) acrylic acid.

  The weight average molecular weight of the prepolymer used in the present invention needs to be less than 50000, preferably 5000 to less than 50000, more preferably 5000 to 40000, and further preferably 10,000 to 35000. If the weight average molecular weight is within the above range, excellent high hardness and blocking resistance can be obtained. Here, the weight average molecular weight is a value measured by gel permeation chromatography (GPC), and is a value measured under conditions using polystyrene as a standard sample.

  Further, from the viewpoint of obtaining excellent surface characteristics, the double bond equivalent of the prepolymer is 100 to 800, preferably 150 to 500, and more preferably 150 to 300. Here, the double bond equivalent means the molecular weight per 1 mol of the ionizing radiation curable functional group.

<Reactive inorganic particles>
The ink composition of the present invention contains reactive inorganic particles having ionizing radiation-curable functional groups B on the surface. Preferred examples of the ionizing radiation-curable functional group B include ethylenically unsaturated bonds such as vinyl groups, (meth) acryloyl groups, and allyl groups, epoxy groups, silanol groups, and the like, which improve high hardness and scratch resistance. From the viewpoint, the vinyl group, (meth) acryloyl group, and allyl group are more preferable.

  Preferred examples of the inorganic particles include metal oxide particles such as silica particles (colloidal silica, fumed silica, precipitated silica, etc.), alumina particles, zirconia particles, titania particles, and zinc oxide particles. From the viewpoint, silica particles and alumina particles are preferable, and silica particles are particularly preferable.

Examples of the shape of the inorganic particles include a sphere, an ellipsoid, a polyhedron, a scale shape, and the like, and these shapes are preferably uniform and sized.
The average particle diameter of the inorganic particles can be appropriately selected depending on the thickness of the layer formed from the ink composition, but is usually preferably 0.005 to 0.5 μm, and more preferably 0.01 to 0.1 μm. Here, the average particle diameter is a 50% particle diameter (d50: median diameter) when the particles in the solution are measured by a dynamic light scattering method and the particle diameter distribution is expressed as a cumulative distribution. It can be measured using a meter (manufactured by Nikkiso Co., Ltd.).

  Among inorganic particles, irregularly shaped inorganic particles are preferable from the viewpoint of high hardness. The irregular shaped inorganic particles are composed of a group of inorganic particles in which the inorganic particles are connected and aggregated with an average number of connections of 2 to 40, and are included in the inorganic particles in the present invention. Connected aggregation may be regular or irregular. As the inorganic particles forming the inorganic particle group, inorganic particles composed of metal oxides such as silica (colloidal silica, fumed silica, precipitated silica, etc.), alumina, zirconia, titania, zinc oxide are preferably mentioned. From the viewpoint of improving the hardness, it is preferable to use irregular shaped inorganic particles made of silica or alumina. That is, the irregularly shaped inorganic particles are preferably composed of a silica particle group or alumina particle group in which silica particles or alumina particles are linked and aggregated having an average number of connections of 2 to 40, and in particular, the silica particles have an average number of connections of 2 to 40. A deformed silica particle composed of a group of linked and aggregated silica particles is preferred.

Preferred examples of the shape of the inorganic particles forming the inorganic particle group include a sphere, an ellipsoid, a polyhedron, and a scale shape. These shapes are preferably uniform and sized.
The average particle diameter of the inorganic particles forming the inorganic particle group is preferably 0.005 to 0.5 μm, and more preferably 0.01 to 0.1 μm. The average particle diameter of the irregularly shaped inorganic particles can be appropriately selected depending on the thickness of the layer formed from the ink composition, but is usually preferably 0.005 to 0.5 μm, more preferably 0.01 to 0.1 μm. . Here, the average particle size is measured by the same method as the average particle size of the inorganic particles described above.

The reactive inorganic particles are preferably reactive silica particles or reactive irregularly shaped silica particles having ionizing radiation-curable functional groups B on the surface of the silica particles or irregularly shaped silica particles as described above, and are surface-decorated with a silane coupling agent. Are preferred.
Preferred examples of the silane coupling agent include known silane coupling agents having a vinyl group, an epoxy group, a (meth) acryloyl group, an allyl group, and the like. More specifically, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyldimethylmethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyldimethylethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-acryloxypropyl Dimethylmethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropylmethyldiethoxysilane, γ-acryloxypropyldimethylethoxysilane, vinyltriethoxysilane, γ-glycidoxy Cypropyltrimethoxysilane and the like are preferably exemplified, and γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, and γ-methacryloxypropyldimethylmethoxysilane are more preferable.

  The method of decorating the surface of the inorganic particles with the silane coupling agent is not particularly limited and may be any known method, such as a dry method of spraying the silane coupling agent or silane coupling after dispersing the inorganic particles in a solvent. Examples thereof include a wet method in which an agent is added and reacted.

<Polyfunctional isocyanate compound>
The ink composition of the present invention contains a polyfunctional isocyanate compound having two or more isocyanate groups. Examples of the polyfunctional isocyanate include aromatic isocyanates such as 2,4-tolylene diisocyanate (TDI), xylene diisocyanate (XDI), naphthalene diisocyanate, 4,4′-diphenylmethane diisocyanate, or 1,6-hexamethylene diisocyanate. And polyisocyanates such as aliphatic (or alicyclic) isocyanates such as (HMDI), isophorone diisocyanate (IPDI), methylene diisocyanate (MDI), hydrogenated tolylene diisocyanate, and hydrogenated diphenylmethane diisocyanate. Further, adducts or multimers of these various isocyanates, for example, adducts of tolylene diisocyanate, tolylene diisocyanate trimers, etc., blocked isocyanate compounds, and the like are also included.
In the present invention, among the polyfunctional isocyanate compounds, those having at least one selected from a vinyl group, a (meth) acryloyl group, an allyl group, and an epoxy group as the ionizing radiation curable functional group C have a high hardness. From the viewpoint, it is particularly preferable, and specifically, “Laromer LR9000 (trade name)” (manufactured by BASF) has at least one functional group having an ethylenically unsaturated bond and a polyvalent compound having two or more isocyanate groups. Functional isocyanate compounds are preferred.

<solvent>
The ink composition of the present invention may contain a solvent for the purpose of adjusting the viscosity. Solvents include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, isopropyl alcohol, butanol, isobutyl alcohol, methyl glycol, methyl glycol acetate, methyl cellosolve, ethyl cellosolve, butyl cellosolve; acetone, methyl ethyl ketone, methyl isobutyl Ketones such as ketone, cyclohexanone, diacetone alcohol; esters such as methyl formate, methyl acetate, ethyl acetate, ethyl lactate, butyl acetate; nitrogen-containing compounds such as nitromethane, N-methylpyrrolidone, N, N-dimethylformamide; Ethers such as propylene glycol monomethyl ether, diisopropyl ether, tetrahydrofuran, dioxane, dioxolane; methylene chloride, chloroform Preferred are halogenated hydrocarbons such as chloromethane, trichloroethane and tetrachloroethane; other substances such as dimethyl sulfoxide and propylene carbonate; or a mixture thereof. More preferred solvents include methyl ethyl ketone and methyl isobutyl ketone.
The amount of the solvent in the ink composition may be appropriately selected according to the viscosity of the composition, but the solid content of the prepolymer, the reactive inorganic particles, and other photopolymerization initiators described later are combined. The amount is usually about 10 to 70% by mass, preferably 20 to 50% by mass.

<Photopolymerization initiator>
The ink composition of the present invention can contain a photopolymerization initiator.
Examples of the photopolymerization initiator include acetophenone series, ketone series, benzophenone series, benzoin series, ketal series, anthraquinone series, disulfide series, thioxanthone series, thiuram series, and fluoroamine series. Of these, acetophenone, ketone, and benzophenone are preferred. These photopolymerization initiators can be used alone or in combination of two or more.
The content of the photopolymerization initiator is preferably about 0.5 to 10 parts by mass, more preferably 1 to 8 parts by mass, further preferably 3 to 100 parts by mass of the solid content of the prepolymer. 8 parts by mass.

<Other ingredients>
The ink composition of the present invention may contain various additives depending on the desired physical properties to be obtained. Examples of additives include ultraviolet absorbers, infrared absorbers, light stabilizers, polymerization inhibitors, crosslinking agents, antistatic agents, antioxidants, leveling agents, thixotropic agents, coupling agents, plasticizers, and antifoaming agents. Agents, fillers, thermal radical generators, aluminum chelating agents and the like.
In addition, the ink composition of the present invention is a polymer such as an acrylic resin, a cellulose resin, a urethane resin, a polyester resin, and an epoxy resin, or vinyl as an ionizing radiation curable functional group, as long as the effect is not impaired. Monomer having at least one selected from a group, (meth) acryloyl group, allyl group and epoxy group, such as urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, and polyether (meth) acrylate A reactive monomer such as a polyfunctional (meth) acrylate can also be blended.

<Composition of ink composition>
The ink composition of the present invention comprises the above-mentioned prepolymer, reactive inorganic particles and polyfunctional isocyanate compound, and the solid content of the prepolymer relative to the total of the solid content of the prepolymer and the reactive inorganic particles. Content needs to be 15-75 mass%, Preferably it is 20-70 mass%, More preferably, it is 30-50 mass%.
If the content of the prepolymer is within the above range, a hard coat layer formed by applying the ink composition on a release layer when forming a hard coat layer forming layer using the ink composition The layer is tack-free just by heat-drying as needed, so even if the sheet is rolled up, it does not undergo semi-curing treatment such as irradiation with ionizing radiation or high-temperature baking. There is nothing to do. In addition, since the need for the semi-curing treatment is eliminated, even when deep drawing is performed such that the area ratio of the decorative sheet before and after molding becomes 130% or more when formed, cracks and whitening occur in the maximum stretched portion. It is possible to form a hard coat forming layer that can follow the shape of the mold well without being generated. Furthermore, excellent high hardness can be obtained by curing the hard coat forming layer using ionizing radiation after molding transfer.

  Further, the solid content of the polyfunctional isocyanate compound in the ink composition of the present invention is preferably 1 to 30 parts by mass, more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the solid content of the prepolymer. 3 to 15 parts by mass is more preferable. When the content of the solid content of the polyfunctional isocyanate compound is within the above range, heat resistance during molding can be obtained while maintaining excellent high hardness and moldability.

[Decorative sheet]
The decorative sheet of the present invention has at least a release layer and a hard coat layer forming layer in order on one side of the base film, and the hard coat layer forming layer is formed using the ink composition of the present invention. Is. Hereinafter, the decorative sheet of the present invention will be described with reference to FIGS. 1 and 2. Drawing 1 is a mimetic diagram showing the section about the desirable one mode of the decorating sheet of the present invention. FIG. 2 is a schematic diagram showing a cross section of a preferred embodiment of the decorative molded product of the present invention.
The decorative sheet 10 of the present invention shown in FIG. 1 has a release layer 12, a hard coat layer forming layer 13, an anchor layer 14, a picture layer 15 and an adhesive layer on one surface of a base film 11 made of a polyester film. 16 is laminated in order, and the antistatic layer 19 is laminated on the other surface of the base film 11 (the surface opposite to the surface on which the release layer 11 is provided). Further, the decorative molded product 20 of the present invention shown in FIG. 2 is a hard coat formed by curing the adhesive layer 16, the pattern layer 15, the anchor layer 14, and the hard coat layer forming layer 13 on the surface of the resin molded body 21. The layers 22 are sequentially stacked.

<Base film>
Examples of the base film 11 include polyolefin resins such as polyethylene and polypropylene; vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene / vinyl acetate copolymer, and ethylene / vinyl alcohol copolymer; polyethylene terephthalate. Polyester resins such as polybutylene terephthalate; Acrylic resins such as poly (meth) acrylate methyl and poly (meth) ethyl acrylate; Styrene resins such as polystyrene, Acrylonitrile butadiene styrene copolymers, Cellulose triacetate Those made of an elastomeric resin such as cellophane, polycarbonate, and polyurethane are used. Of these, polyester resins, particularly polyethylene terephthalate (hereinafter referred to as “PET”) are preferred from the viewpoint of good moldability and peelability.
The thickness of the base film 11 is preferably in the range of 25 to 150 μm, more preferably in the range of 25 to 75 μm, from the viewpoints of moldability, shape followability, and easy handling.

<Release layer 12>
The release layer 12 preferably has a transfer layer 17 formed by laminating a hard coat layer forming layer 13, an anchor layer 14, a pattern layer 15, and an adhesive layer 16 in order so that the release layer 12 can be easily peeled off from the substrate sheet 11. It is a layer to be provided. By having the release layer 12, the transfer layer 17 is reliably and easily transferred from the decorative sheet of the present invention to the transfer target, and is provided with the base film 11, the release layer 12, and if necessary. The release layer 18 composed of the antistatic layer 19 can be reliably peeled off.

  For the release layer 12, melamine resin release agent, silicone resin release agent, fluororesin release agent, cellulose resin release agent, urea resin release agent, polyolefin resin release agent, paraffin A mold release agent such as a system mold release agent, an acrylic resin mold release agent, or a composite mold release agent thereof is preferably used. Among these, from the viewpoint of making the peel strength between the release layer and the hard coat layer forming layer within a predetermined range and reliably peeling the release layer 18, a melamine resin release agent and an acrylic resin release agent, or What combined these, such as an acryl-melamine type, is preferable.

  When a melamine resin release agent is used, it is preferable to use an acid catalyst in order to promote curing of the release agent. The acid catalyst is not particularly limited, and preferable examples include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, and dinonylnaphthalenedisulfonic acid. The amount of the acid catalyst used is preferably about 0.05 to 3%, more preferably 0.05 to 1%, based on the solid content of the melamine resin contained in the melamine resin release agent. Moreover, in order to promote hardening of a mold release agent, it is preferable to perform 130-170 degreeC heat processing for about 30 second-2 minutes.

  The release layer 12 is formed by applying an ink prepared by dissolving or dispersing the above-described additive added to a release agent in an appropriate solvent onto the base sheet 11 by a known means. -It can dry and can carry out and thickness is preferable about 0.1-5 micrometers.

<< Hard Coat Layer Forming Layer 13 >>
The hard coat layer forming layer 13 is a layer formed using the above-described ink composition of the present invention, and is a layer for forming the hard coat layer 22 in the decorative molded product 20 by curing with ionizing radiation. The hard coat layer 22 is an outermost layer of the decorative molded product, and is a layer for protecting the molded product and the picture layer from abrasion and chemicals. Therefore, the hard coat layer forming layer 13 is a layer having the performance of being excellent in surface physical properties such as chemical resistance and contamination resistance as well as excellent high hardness and scratch resistance by being cured. Cost.

<Formation of hard coat layer forming layer 13>
The hard coat layer forming layer 13 is formed by coating the ink composition of the present invention by a coating method such as a gravure coating method, a roll coating method, a comma coating method, a die coating method, a gravure printing method, a screen printing method, or the like. can do.
The thickness of the hard coat layer forming layer 13 is preferably in the range of 0.5 to 30 μm, more preferably 3 to 15 μm. When the thickness is in the above range, not only excellent high hardness and scratch resistance, but also surface properties such as chemical resistance and stain resistance are obtained, and at the same time, excellent moldability and shape followability are obtained. Obtainable. It is also advantageous in terms of material costs.

<< Anchor layer 14 >>
The anchor layer 14 is a layer provided as desired in order to improve the adhesion between the hard coat layer forming layer 13 and the adhesive layer 16 or the pattern layer 15 when there is the pattern layer 15.
The anchor layer 14 is a two-component curable urethane resin, a thermosetting urethane resin, a melamine resin, a cellulose ester resin, a chlorine-containing rubber resin, a chlorine-containing vinyl resin, an acrylic resin, an epoxy resin, and a vinyl copolymer. For example, a coating resin such as a gravure coating method, a roll coating method, or a comma coating method, a gravure printing method, a screen printing method, or the like is applied on the hard coat layer forming layer 13 formed as described above using a coalesced resin. Can be formed.
The thickness of the anchor layer 14 is usually about 0.1 to 5 μm, preferably about 1 to 5 μm.

<< Pattern layer 15 >>
The pattern layer 15 is a layer for imparting a desired design to the decorative molded product, and is a layer provided as desired. Although the pattern of the pattern layer 15 is arbitrary, for example, a pattern composed of wood grain, stone pattern, cloth pattern, sand pattern, geometric pattern, character, and the like can be mentioned. In addition, the pattern layer 15 can be provided with a pattern pattern layer expressing the above pattern and a whole surface solid layer alone or in combination, and the whole surface solid layer is usually used as a concealing layer, a colored layer, a colored concealing layer, or the like. .

The pattern layer 15 is usually a polyvinyl resin, a polyester resin, an acrylic resin, a polyvinyl acetal resin, a cellulosic resin on the hard coat layer forming layer 13 or the anchor layer 14 formed as described above. It is formed by printing with a printing ink containing a resin such as a resin as a binder and a pigment or dye of an appropriate color as a colorant. Examples of the printing method include known printing methods such as gravure printing, offset printing, silk screen printing, transfer printing from a transfer sheet, sublimation transfer printing, and ink jet printing.
The thickness of the pattern layer 15 is preferably 5 to 40 μm and more preferably 5 to 30 μm from the viewpoint of design.

<< Adhesive layer 16 >>
The adhesive layer 16 is a layer formed to transfer the transfer layer 17 to the resin molded body with good adhesiveness. For the adhesive layer 16, a heat-sensitive or pressure-sensitive resin suitable for the material of the resin molded body is appropriately used. For example, when the material of the resin molding is an acrylic resin, it is preferable to use an acrylic resin. If the resin molding is made of polyphenylene oxide / polystyrene resin, polycarbonate resin, or styrene resin, use an acrylic resin, polystyrene resin, polyamide resin, or the like that has an affinity for these resins. Is preferred. Furthermore, when the material of the resin molding is a polypropylene resin, it is preferable to use a chlorinated polyolefin resin, a chlorinated ethylene-vinyl acetate copolymer resin, a cyclized rubber, or a coumarone indene resin.

Examples of the method for forming the adhesive layer 16 include a coating method such as a gravure coating method and a roll coating method, a printing method such as a gravure printing method and a screen printing method. In addition, when the pattern layer 15 has sufficient adhesiveness with respect to a resin molding, the contact bonding layer 16 does not need to be provided.
As for the thickness of the contact bonding layer 16, about 0.1-5 micrometers is preferable normally.

<Antistatic layer 19>
The decorative sheet of the present invention can be provided with an antistatic layer 19. The antistatic layer 19 is a layer that is preferably provided in order to prevent foreign matter from adhering to the decorative sheet, and is provided on the surface of the base film 11 opposite to the surface on which the release layer is provided.
Antistatic agents used for the antistatic layer include anionic surfactants such as carboxylic acid, sulfonic acid, and phosphoric acid; cationic surfactants such as quaternary ammonium; alkylbetaine, alkylimidazoline , Amphoteric surfactants such as alkylalanine; nonionic surfactants such as alkylene oxide polymers, alkylene oxide copolymers, aliphatic alcohol-alkylene oxide adducts; carbon, gold, platinum, silver, copper, Inorganic conductive materials such as various metal powders such as aluminum, nickel, titanium and molybdenum; polyacetylene, polypyrrole, polyparaphenylene, polyaniline, polythiophene, polyphenylene vinylene, polyvinyl carbazole, or aminocarboxylic acid, dicarboxylic acid and polyethylene glycol A conductive polymer such as polyether ester amide resin consisting Lumpur are preferably exemplified.

  The antistatic layer is formed by applying a coating material composed of the above-described antistatic agent and an organic solvent by a coating method such as a gravure coating method or a roll coating method, or a printing method such as a gravure printing method or a screen printing method. The thickness of the antistatic layer formed in this manner is usually preferably 0.1 to 5 μm. If the thickness of the antistatic layer is within the above range, excellent antistatic performance can be obtained efficiently.

《Use of decorative sheet, etc.》
The decorative sheet of the present invention is excellent in production efficiency because it is tack-free as long as the hard coat layer forming layer is heat-dried as necessary, and therefore has excellent blocking resistance and at the same time heat resistance. Moreover, since it is not necessary to perform a semi-curing treatment by irradiation with ionizing radiation or high-temperature baking in order to make it tack-free, it has excellent moldability and shape followability. Furthermore, by curing the hard coat layer forming layer using ionizing radiation after molding transfer, excellent high hardness and scratch resistance can be obtained. For these reasons, it can be used in a wide range of fields such as household electrical appliances and automobile interior parts, personal computer fields, especially personal computer housings.

[Method of manufacturing decorative molded product]
The method for producing a decorative molded product according to the present invention includes a step (1) a step of arranging the decorative sheet of the present invention in an injection mold; a step (2) injecting a molten resin into the cavity, and cooling and solidifying. Then, an injection step of laminating and integrating the resin molded body and the decorative sheet; step (3) a step of taking out the molded body integrated with the resin molded body and the decorative sheet from the mold; step (4) from the molded body A step of peeling the base film of the decorative sheet; and a step (5) a hard coat layer forming step of curing the hard coat layer forming layer provided on the molded body using ionizing radiation.

<< Process (1) >>
Step (1) is a step of placing and decorating the decorative sheet of the present invention in a molding die. Specifically, the decorative sheet is placed in a molding die composed of a movable mold and a fixed mold with the transfer layer 17 inside, that is, the base film 11 is on the fixed mold side. Send it in. At this time, a single sheet of decorative sheet may be fed one by one, or a necessary part of a long decorative sheet may be intermittently fed.

  When placing the decorative sheet in the molding die, (i) simply heat the die and place it so as to adhere to the die by vacuum suction, or (ii) place a heating plate from the transfer layer 17 side. It can be heated and softened, preliminarily molded so that the decorative sheet follows the shape in the mold, and clamped so as to be in close contact with the inner surface of the mold. The heating temperature at (ii) is preferably in the range of near the glass transition temperature of the substrate film 11 and less than the melting temperature (or melting point), and is usually performed at a temperature near the glass transition temperature. In addition, said glass transition temperature vicinity is the range of about glass transition temperature +/- 5 degreeC, and is generally about 70-130 degreeC. In the case of (ii), vacuuming can also be performed when the decorative sheet is heated and softened with a hot plate for the purpose of bringing the decorative sheet into close contact with the surface of the molding die.

<< Step (2) >>
Step (2) is an injection step in which molten resin is injected into the cavity, cooled and solidified, and the resin molded body and the decorative sheet are laminated and integrated. When the injection resin is a thermoplastic resin, it is made into a fluid state by heating and melting. When the injection resin is a thermosetting resin, the uncured liquid composition is appropriately heated and injected in a fluid state, and then cooled. And solidify. As a result, the decorative sheet is integrally attached to the formed resin molded body, and becomes a decorative molded product. The heating temperature of the injection resin is generally about 180 to 280 ° C. although it depends on the injection resin.

(Injection resin)
The injection resin used for the decorative molded product may be any thermoplastic resin that can be injection-molded or a thermosetting resin (including a two-component curable resin), and various resins can be used. Examples of such thermoplastic resin materials include polystyrene resins, polyolefin resins, ABS resins (including heat-resistant ABS resins), AS resins, AN resins, polyphenylene oxide resins, polycarbonate resins, polyacetal resins, and acrylic resins. Examples thereof include resins, polyethylene terephthalate resins, polybutylene terephthalate resins, polysulfone resins, and polyphenylene sulfide resins. Examples of the thermosetting resin include a two-component reaction curable polyurethane resin and an epoxy resin. These resins may be used alone or in combination of two or more.

<< Step (3) and Step (4) >>
Step (3) is a step of removing from the mold a molded body in which the decorative sheet and the resin molded body are integrated, and step (4) is a step of peeling the base film of the decorative sheet from the molded body. It is. Since the base film 11 has the release layer 12, at the boundary surface between the release layer 12 and the hard coat layer forming layer 13, the base film 11 and the release layer 12, and as necessary. The release layer 18 including the antistatic layer 19 provided can be easily peeled from the decorative molded product 20. In this manner, a molded product is obtained in which the adhesive layer 16, the pattern layer 15, the anchor layer 14, and the hard coat layer forming layer 13 are sequentially laminated on the surface of the resin molded body 21.

<< Step (5) >>
Step (5) is a step of forming a hard coat layer by curing the hard coat layer forming layer 13 in the molded product obtained in the step (4) using ionizing radiation. The curing in the step (5) can be performed by irradiating with ionizing radiation in an atmosphere having an oxygen concentration of 2% or less. By performing the curing in this way, it is possible to obtain further excellent high hardness and scratch resistance.

  The atmosphere having an oxygen concentration of 2% or less can be obtained by, for example, nitrogen, argon, hydrogen, etc., preferably using nitrogen, or performing air suction so that the oxygen concentration is about 2% or less.

The hard coat layer forming layer 13 can be cured by irradiation with ionizing radiation such as electron beams and ultraviolet rays.
When an electron beam is used as the ionizing radiation, the acceleration voltage can be appropriately selected according to the type of polymer or monomer to be used or the thickness of the hard coat layer forming layer 13, but usually an acceleration voltage of about 70 to 300 kV is preferable. The irradiation dose 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). 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, and the irradiation dose is about 500 to 1500 mJ. 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 decorative molded product thus obtained has excellent high hardness and excellent surface properties such as chemical resistance and stain resistance. In addition, by using the decorative sheet of the present invention that provides moldability that can correspond to a molded product having a more complicated shape, a decorative molded product that is excellent in finish can be obtained.
The decorative molded product of the present invention can be suitably used in a wide range of fields such as household electrical appliances and automobile interior parts, and in the field of personal computers, especially personal computer casings, taking advantage of these excellent characteristics. Can do.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by this example. In addition, the evaluation method in this invention was performed with the following method.
1. Preparation of test sample On substrate film (“F99 (product number)”, thickness: 50 μm, manufactured by Toray Industries, Inc.), melamine resin mold release agent (melamine resin solid content ratio 0.5% acid catalyst (para Toluenesulfonic acid) is added) and is gravure-printed at a coating amount of 2 g / m ² , heat-treated in an oven at 150 ° C. for 60 seconds to form a release layer, and used in each example and comparative example. The ink composition was applied with a bar coater and dried in an oven at 100 ° C. for 60 seconds to obtain a test sample. Here, the coating amount of the ink composition was such that the thickness of the dried ink coating layer was 6 g / m ² .
2. Evaluation of blocking resistance (applicability to sheet winding) The PET film used for the preparation of the test sample was superimposed on the ink coating layer surface of the test sample, and an ink blocking tester ("DG-BT (model number)", Daiwa Gravure Inc. Was used for 12 hours in an oven at 40 ° C. while applying a load of 1 kg / cm ² . Then, the test sample was taken out and the superimposed PET film was peeled off. The removal (inversion) of the ink coating layer on the peeled PET film was evaluated according to the following criteria.
○: There was no set-off. △: There was some set-up, but there was no problem in practical use. X: Set-up was remarkable. Evaluation of high hardness After a test sample is cured by the curing method in each of the examples and comparative examples, a pencil scratch coating film hardness tester (“D-NP” (model number) is used in accordance with JIS K5600-5-4. ) ”, Manufactured by Toyo Seiki Seisakusho Co., Ltd.), and a pencil scratch test pencil (manufactured by Mitsubishi Pencil Co., Ltd.).
The test of scratching the ink coating layer with a pencil of each hardness was conducted 5 times, and the pencil hardness of which the scar did not occur 3 times or more was defined as the pencil hardness of the test sample.

Synthesis example (Prepolymer synthesis)
A 2 L four-necked flask equipped with a condenser, dropping funnel and thermometer was charged with 120 g of methyl isobutyl ketone (MIBK) and 210 g of methyl ethyl ketone (MEK). The four-necked flask was charged with 80 g of glycidyl methacrylate (GMA), MMA) 20 g and an azo-based initiator (azobisisobutyronitrile, AIBN-1) 1 g of a mixture solution was dropped for 2 hours with a dropping funnel over 2 hours, and reacted at a temperature of 100 to 110 ° C. for 4 hours. Thereafter, 1 g of an azo initiator (azobisisobutyronitrile, AIBN-2) was further added, and the mixture was kept warm for 3 hours and then cooled to room temperature. To this, a mixed solution consisting of 40.6 g of acrylic acid (AA), 2 g of triphenylphosphine, and 0.5 g of methoquinone was added to carry out an addition reaction. The neutralization titration of the potassium hydroxide solution confirmed the disappearance of the acid value of the reactive organism, and the reaction was terminated.
The obtained reaction product (prepolymer) had a weight average molecular weight of 25,000, a double bond equivalent of 250 g / mol (calculated value), and a solid content of 30%. The weight average molecular weight is a value measured by gel permeation chromatography (GPC), and is a value measured under conditions using polystyrene as a standard sample.

＊，表中の配合組成欄の数値は、いずれもグラムである。

* The numerical values in the blend composition column in the table are all in grams.

Example 1
(1) Manufacture of a decorative sheet On a base film (“F99 (product number)”, thickness: 50 μm, manufactured by Toray Industries, Inc.), a coating liquid (“Melan 265” (product number) containing melamine resin as a main component. ), Manufactured by Hitachi Chemical Co., Ltd., isobutyl alcohol-modified melamine resin) at a coating amount of 2 g / m ² to form a release layer, and the ink composition shown below was applied at a coating amount of 6 g / m ^2. The hard coat layer forming layer was formed by gravure printing. Next, an anchor layer is formed by gravure printing with a coating containing acrylic resin as a main component at a coating amount of 4 g / m ² , and then a gravure printing is performed with an acrylic printing ink at a coating amount of 8 g / m ^2. Then, a pattern layer was formed, and an acrylic coating solution was applied at a thickness of 4 μm to form an adhesive layer. Furthermore, a coating liquid (cationic surfactant: quaternary ammonium salt) containing a cationic surfactant as a main component is applied to the surface of the base film opposite to the surface provided with the release layer. Gravure printing was performed at an amount of 1 g / m ² to form an antistatic layer, and a decorative sheet of Example 1 was obtained. Further, using the ink composition used in Example 1, the above 1. A test sample was prepared based on the preparation of the test sample, and evaluation of blocking resistance (sheet winding suitability) and high hardness were performed. These evaluations are shown in Table 2.
(Ink composition)
Prepolymer: 20.0 parts by mass (solid content 6 parts by mass), acrylic acrylate prepolymer (the prepolymer synthesized in the above synthesis example)
Reactive irregularly shaped silica particles: 10 parts by mass (4 mass parts solids), ("ELCOM V-8803 (product number)", manufactured by JGC Catalysts & Chemicals, Inc., reactive irregularly shaped silica particles, average number of connections: regularly 2 10 particles, average particle size of irregularly shaped inorganic particles; 25 nm)
Reactive polyfunctional isocyanate: 1 part by mass (solid content 1 part by mass), ("Laromer LR9000 (product number)", manufactured by BASF)
Photopolymerization initiator: 0.4 parts by mass ("IRGACURE 184 (product number)", manufactured by Ciba Japan, 1-hydroxycyclohexyl phenyl ketone)
Solvent: 6.7 parts by mass, mixed solvent of methyl ethyl ketone and methyl isobutyl ketone (blending ratio 70:30)

(2) Production of decorative molded product The decorative sheet obtained in (1) above was sucked into a mold heated to 70 ° C. and adhered to the inner surface of the mold. The mold used was a 80 mm square size, 5 mm rising tray shape with a 12R corner shape and a deep deep shape.
On the other hand, ABS resin (“Crustic MTH-2 (product number)”, manufactured by Nippon A & L Co., Ltd.) was used as the injection resin, and this was melted at 230 ° C. and then injected into the cavity. After cooling and taking out from the mold, the base film was peeled off to obtain a molded product having an adhesive layer, a printing layer, an anchor layer and a hard coat layer forming layer on the surface of the resin molded product in this order. Furthermore, using an output variable type UV lamp system (“DRS-10 / 12QN (model number)”, manufactured by Fusion UV Systems Japan Co., Ltd.) in an air atmosphere, the molded product is irradiated with ultraviolet rays at an irradiation dose of 1000 mJ. Then, the hard coat layer forming layer was cured to obtain a resin molded product of Example 1 as a hard coat layer.

4). Evaluation of Appearance (Heat Resistance) Further, the appearance (heat resistance) around the gate part (resin injection part) of the obtained resin molded product was evaluated according to the following criteria. The evaluation is shown in Table 2.
◎: Deformation or whitening due to flow could not be confirmed at all in the hard coat layer (and its formation layer), and followed the shape of the mold well. ○: Deformation due to slight flow in the hard coat layer (and its formation layer) Slight whitening was confirmed. △: Slight deformation and slight whitening were confirmed in the hard coat layer (and its formation layer), but no problem in practical use. ×: In the hard coat layer (and its formation layer). Deformation and whitening due to significant flow were confirmed

Examples 2, 3 and Comparative Examples 1-3
In Example 1, decorative sheets and decorative molded articles of Examples 2 and 3 and Comparative Examples 1 to 3 were obtained in the same manner as in Example 1 except that the ink composition is shown in Table 2. About the used ink composition, evaluation of said blocking resistance (sheet winding suitability) and evaluation of high hardness were performed, and said external appearance evaluation was performed about the obtained decorative molded product. The results are shown in Table 2.

＊１，非反応性コロイダルシリカ粒子（「ＭＥＫ−ＳＴ−Ｌ（品番）」，日産化学工業株式会社製，平均粒子径ｄ５０：４０ｎｍ）
＊２，多官能イソシアネート：「コロネートＨＸ（品番）」，日本ポリウレタン工業株式会社製
＊３，溶媒の量は、溶媒を加えた量と、ポリマー１と反応性無機粒子として使用した「ＥＬＣＯＭ Ｖ−８８０３（品番）」に含まれる溶媒との合計量である。
＊４，プレポリマー固形分と反応性無機粒子との合計に対するプレポリマー固形分の含有量（質量％）である。
＊５，プレポリマー、反応性無機粒子、（反応性）多官能イソシアネート、光重合開始剤及び溶剤の合計に対するプレポリマー固形分、反応性無機粒子、（反応性）多官能イソシアネート及び光重合開始剤の合計の含有量（質量％）である。

* 1, Non-reactive colloidal silica particles (“MEK-ST-L (product number)”, manufactured by Nissan Chemical Industries, Ltd., average particle size d50: 40 nm)
* 2, Polyfunctional isocyanate: “Coronate HX (product number)”, manufactured by Nippon Polyurethane Industry Co., Ltd. * 3. The amount of the solvent is the amount of the solvent added, and “ELCOM V-” used as the polymer 1 and reactive inorganic particles. 8803 (product number) ”.
* 4 Content of prepolymer solids (% by mass) relative to the total of prepolymer solids and reactive inorganic particles.
* 5 Prepolymer, reactive inorganic particles, (reactive) polyfunctional isocyanate, photopolymerization initiator and prepolymer solid content relative to the total of solvent, reactive inorganic particles, (reactive) polyfunctional isocyanate and photopolymerization initiator Is the total content (mass%).

  According to the present invention, the decorative molded product is imparted with excellent high hardness, and at the same time, it is imparted with moldability to obtain a molded product with a more complicated shape, and the hard coat layer forming layer is heat-dried as necessary. Provided is an ink composition that imparts excellent production efficiency to a decorative sheet, which can be tack-free only, a decorative sheet using the ink composition, and a decorative molded product using the decorative sheet be able to. Therefore, the ink composition according to the present invention, a decorative sheet using the ink composition, and a decorative molded product using the decorative sheet include household appliances, automobile interior parts, automobile exteriors, mobile phone fields, and the like. It is effective in a wide range of fields such as the field of personal computers and the field of personal computers, especially the housing of personal computers.

DESCRIPTION OF SYMBOLS 10 Decorating sheet 11 Base film 12 Release layer 13 Hard coat layer forming layer 14 Anchor layer 15 Picture layer 16 Adhesive layer 17 Transfer layer 18 Peeling layer 19 Antistatic layer 20 Decorated molded body 21 Resin molded body 22 Hard coat layer

Claims (8)

  A polyfunctional radical polymerization prepolymer having at least one selected from a vinyl group, a (meth) acryloyl group and an allyl group as the ionizing radiation curable functional group A, and having a weight average molecular weight of less than 50,000, ionizing radiation curable on the surface Reactive inorganic particles having a functional group B and a polyfunctional isocyanate compound, the solid content of the prepolymer with respect to the total of the solid content of the prepolymer and the reactive inorganic particles is 15 to 75% by mass An ink composition.   The ink composition according to claim 1, wherein the reactive inorganic particles are reactive silica particles and / or reactive irregularly shaped silica particles.   The ink composition according to claim 1, wherein the polyfunctional radical polymerization type prepolymer is an acrylic (meth) acrylate prepolymer.   The ink according to any one of claims 1 to 3, wherein the polyfunctional isocyanate compound has at least one selected from a vinyl group, a (meth) acryloyl group, an allyl group and an epoxy group as the ionizing radiation-curable functional group C. Composition.   A decorative sheet having at least a release layer and a hard coat layer forming layer on one side of the base film in order, wherein the hard coat layer forming layer uses the ink composition according to any one of claims 1 to 4. Decorative sheet that is formed.   The decorative sheet according to claim 5, further comprising an antistatic layer on a surface opposite to the surface on which the release layer of the base film is provided. The manufacturing method of the decorative molded product which has the following process (1) -process (5).
Step (1) Step of arranging the decorative sheet according to claim 5 or 6 in the injection mold (2) Step of injecting molten resin into the cavity, cooling and solidifying, resin molded body and decoration An injection process step of stacking and integrating the sheets (3) A step of removing the molded body in which the resin molded body and the decorative sheet are integrated from the mold (4) Peeling the base film of the decorative sheet from the molded body Step (5) Hard coat layer forming step of curing the hard coat layer forming layer provided on the molded body using ionizing radiation   A decorative molded product obtained by the production method according to claim 7.

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