JP2014138985A - Decorative sheet for injection molding, sheet laminate for injection molding and injection molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative sheet for injection molding which has less possibility of inclusion of foreign matters and shows a sufficient black color, a sheet laminate for injection molding and an injection molding.SOLUTION: A resin-made decorative sheet for injection molding is adhered to the outside surface of a resin molding molded by injection molding and has a multi-layer structure consisting of an inner layer adhered to the resin molding and an outer layer laminated on the outside surface of the inner layer, laminated integrally by an extrusion molding method, and the inner and outer layers contain a black colorant. Preferably, the inner and outer layers of the decorative sheet for injection molding both contain the black colorant. The decorative sheet for injection molding preferably has a two-layer structure in which the inner and outer layers are laminated directly. The sheet for injection molding more preferably has a hard coat layer laminated on the outside surface of the outer layer.

Description

  The present invention relates to a decorative sheet for injection molding, a sheet laminate for injection molding, and an injection molded product.

  Conventionally, in the case of an injection molded product that requires a high design, such as an interior product in a vehicle or a building, a resin-made decorative sheet for injection molding (hereinafter sometimes referred to as a “decorative sheet”). Is attached to the outer surface of a resin molded product (see, for example, JP-A-2008-94074). This decorative sheet for injection molding includes a base sheet provided with a printed layer on the outer surface, and a resin sheet laminated on the outer surface side of the base sheet, and the base sheet and the resin sheet are generally Is attached by an adhesive.

  However, in the decorative sheet, if a foreign substance adheres to the base sheet or the resin sheet before the base sheet and the resin sheet are pasted, the foreign substance is mixed between both sheets. There is a risk that. The presence of such foreign matter may reduce the strength and design of the decorative sheet.

  In addition, in an interior product such as a vehicle, the outer surface may be required to exhibit a so-called piano black tone jetness. However, as a conventional injection-molded product, the outer surface of the base sheet is black as a printing layer. Even if it prints, there exists a possibility that sufficient black cannot be exhibited only with a comparatively thin printing layer.

JP 2008-94074 A

  The present invention has been made in view of such circumstances. An object of the present invention is to provide a decorative sheet for injection molding, a sheet laminate for injection molding, and an injection molded product that are less likely to be mixed with foreign matters and can exhibit a sufficient black color.

The present invention has been made to solve the above problems, the decorative sheet for injection molding of the present invention,
A decorative sheet for injection molding made of resin attached to the outer surface of a resin molded product molded by injection molding,
The inner layer bonded to the resin molded product and the outer layer laminated on the outer surface side of the inner layer have a multilayer structure integrally laminated by an extrusion molding method,
The inner layer or the outer layer contains a black colorant.

  In the decorative sheet for injection molding, since the inner layer and the outer layer are integrally laminated by an extrusion molding method, the inner layer and the outer layer are bonded to each other as compared with a conventional sheet bonded with an adhesive. There is little possibility that foreign matter will be mixed in. Moreover, since the decorative sheet for injection molding contains a black colorant in the inner layer or the outer layer, the black color contained in the inner layer or the outer layer as compared with a conventional design having a printed surface. Sufficient black color can be exhibited by the charge.

  Both the inner layer and the outer layer may contain the black colorant. Thereby, the said decoration sheet for injection molding can exhibit more sufficient black.

  In the decorative sheet for injection molding, an intermediate layer can be provided between the inner layer and the outer layer, but preferably has a two-layer structure in which the inner layer and the outer layer are directly laminated. By directly laminating the inner layer and the outer layer in this way, it is possible to suppress an increase in manufacturing cost because no other layer is provided.

  The decorative sheet for injection molding may further include a hard coat layer laminated on the outer surface of the outer layer. Thereby, for example, after the decoration sheet for injection molding is attached to the outer surface of the resin molded product, the outer surface of the outer layer can be accurately prevented from being damaged by the hard coat layer.

  The arithmetic average roughness (Ra) of the outer surface of the decorative sheet for injection molding is preferably 0.01 μm or more and 0.3 μm or less. When the arithmetic average roughness (Ra) is within the above range, the outer surface is excellent in smoothness, and a so-called piano black tone jetness can be achieved.

  As 60 degree glossiness of the outer surface of the said decorative sheet for injection molding, 70 or more and 90 or less are preferable. When the 60 ° glossiness is within the above range, the glossiness is excellent and so-called piano black tone jetness can be achieved.

  As the black colorant, it is preferable to use both a black dye and a black pigment. Thereby, jet blackness with higher design property can be produced.

  The main component of the outer layer is preferably an acrylic resin. Thereby, the weather resistance and contamination resistance of the decorative sheet for injection molding can be improved.

  The tensile strength of the decorative sheet for injection molding is preferably 20 MPa or more. Thereby, since the said decoration sheet for injection molding deform | transforms correctly in the case of injection molding, the said decoration sheet for injection molding can be suitably attached to the outer surface of a resin molded product.

  As the main component of the inner layer, the same kind of resin as the main component of the resin molded product may be used. Thereby, it is excellent in the adhesiveness of a resin molded product and an inner layer, and the said decorative sheet for injection molding can be suitably attached to the outer surface of a resin molded product. The “same kind of resin” includes those having the same monomer species and having different compositions and different polymerization types.

As the relationship between the linear expansion coefficient (α ₁ ) and glass transition temperature (Tg ₁ ) of the inner layer, the linear expansion coefficient (α ₂ ) and glass transition temperature (Tg ₂ ) of the outer layer, and room temperature, the following formula (1 ) And (2) are preferably 4 × 10 ⁻³ or less.
α ₁ * (Tg ₁ −room temperature) (1)
α ₂ * (Tg ₂ −room temperature) (2)
Thereby, the internal stress at the time of carrying out the coextrusion molding of the inner layer and the outer layer can be reduced, and the occurrence of curling at the room temperature can be suitably prevented.

  Moreover, the injection-molded sheet laminate of the present invention comprises the injection-molding decorative sheet having the above-described configuration, and a release sheet that is releasably laminated on the outer surface side of the outer layer of the injection-molding decorative sheet. Prepare. As a result, the sheet stack for injection molding is arranged so that the release sheet faces the mold surface of the mold, the molten resin is injected into the mold, and the release sheet is peeled off after the resin is cured. By doing so, it is possible to obtain an injection molded product with the injection molding decorative sheet attached to the outer surface, and this injection molded product has a low possibility of foreign matter mixing inside the injection molding decorative sheet. Can exhibit a black color.

  Moreover, the injection molded product of the present invention is provided with the injection molding decorative sheet having the above-described configuration on the outer surface. Thereby, the said injection molded product has little possibility of a foreign material mixing inside the said decorative sheet for injection molding, and can exhibit sufficient black.

  The “colorant” is a concept including a pigment and a dye. The “pigment” refers to a particulate solid that is usually insoluble in a medium such as water, solvent, or oil. “Dye” refers to a colorant that is soluble or at least partially soluble in a medium. “Arithmetic average roughness (Ra)” is a value with a cutoff λc of 2.5 mm and an evaluation length of 12.5 mm in accordance with JIS B 0601-2001. “Glossiness” refers to a value based on JIS Z8741. “Tensile strength” refers to a value in accordance with JIS K 7162. “Glass transition temperature” refers to a value according to JIS K 7121-1987. “Linear expansion coefficient” refers to a value according to JIS K 7197.

  The decorative sheet for injection molding, the sheet laminate for injection molding, and the injection molded product of the present invention are less likely to be mixed with foreign matters and can exhibit a sufficient black color.

It is a typical sectional view showing the decoration sheet for injection molding concerning one embodiment of the present invention. It is typical sectional drawing which shows the decorating sheet for injection molding which concerns on the form different from the decorating sheet for injection molding of FIG. It is typical sectional drawing which shows the sheet | seat laminated body for injection molding which concerns on one Embodiment of this invention. It is typical sectional drawing which shows the injection molded product which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

[First embodiment]
<Decorative sheet for injection molding>
The decorative sheet for injection molding 1 in FIG. 1 has an inner layer 2 and an outer layer 3. The decorative sheet for injection molding 1 is attached to the outer surface of a resin molded product molded by injection molding. In the decorative sheet 1 for injection molding, the inner layer 2 and the outer layer 3 are directly laminated. The decorative sheet for injection molding 1 is formed as a two-layer structure of an inner layer 2 and an outer layer 3.

(Inner layer)
The inner layer 2 is bonded to a resin molded product. The inner layer 2 is formed with a synthetic resin as a main component. The main component of the inner layer 2 is not particularly limited, and examples thereof include thermoplastic resins such as ABS resin, polyolefin resin, styrene resin, acrylic resin, vinyl chloride resin, and polycarbonate resin. Especially, as a main component of the inner layer 2, it is preferable that it is the same kind of resin as the main component of a resin molded product. The decorative sheet for injection molding 1 can improve the adhesiveness between the resin molded product and the inner layer 2 because the main component of the inner layer 2 is the same type of resin as the main component of the resin molded product. Therefore, according to this configuration, the injection molding decorative sheet 1 can be suitably attached to the outer surface of the resin molded product.

  Although it does not specifically limit as average thickness of the inner layer 2, For example, they are 100 micrometers or more and 800 micrometers or less.

  The inner layer 2 contains a black colorant, especially a black pigment. Examples of the black pigment include inorganic black pigments and organic black pigments. Specifically, carbon black (furnace black, channel black, acetylene black, thermal black, lamp black, etc.), graphite (graphite) ), Copper oxide, manganese dioxide, azo pigments (azomethine azo black, etc.), aniline black, perylene black, cyanine black, complex oxide black pigment, titanium black, activated carbon, ferrite (nonmagnetic ferrite, magnetic ferrite, etc.), Examples thereof include magnetite, chromium oxide, iron oxide, molybdenum disulfide, and a chromium complex. Among these, carbon black is preferable as the black pigment contained in the inner layer 2. By using carbon black as the black pigment contained in the inner layer 2, the decorative sheet for injection molding 1 can exhibit a sufficient black color together with the black colorant contained in the outer layer 3 described later. .

  The average particle diameter of the black pigment is preferably 100 nm or more and 30 μm or less. The upper limit of the average particle diameter of the black pigment is more preferably 5 μm, and further preferably 3 μm. On the other hand, the lower limit of the average particle diameter of the black pigment is more preferably 200 nm, and even more preferably 300 nm. If the average particle size of the black pigment is smaller than the lower limit, uniform dispersion may be difficult due to aggregation or the like. On the other hand, when the average particle diameter of the black pigment exceeds the upper limit, there is a risk of causing poor dispersion, poor appearance, and the like.

  Although it does not specifically limit as content of the said black pigment, 0.1 mass% or more and 1 mass% or less are preferable with respect to all the formation components of the inner layer 2. FIG. The upper limit of the content of the black pigment is more preferably 0.8% by mass, and still more preferably 0.5% by mass. On the other hand, the lower limit of the content of the black pigment is more preferably 0.15% by mass, and still more preferably 0.2% by mass. If the content of the black pigment is smaller than the lower limit, a desired black color may not be achieved. Conversely, when the content of the black pigment exceeds the upper limit, the dispersibility of the pigment may be reduced.

  The inner layer 2 may use both a black dye and a black pigment as the black colorant. When the inner layer 2 contains both a black dye and a black pigment as the black colorant, examples of the black dye include azo dyes, acridine dyes, nitroso dyes, nitro dyes, stilbene azo dyes, and ketoimine dyes. , Triphenylmethane dye, xanthene dye, quinoline dye, methine / polymethine dye, anthraquinone dye, thiazole dye, indamine / indophenol dye, azine dye, oxazine dye, thiazine dye, sulfur dye, aminoketone / oxyketone dye, indigoid dye, phthalocyanine Examples include dyes, perylene dyes, and perinone dyes. These dyes can be used alone or in combination of two or more. Moreover, you may express deep black by combining dyes, such as red, green, and yellow.

  Although it does not specifically limit as content of the said black-type dye, 0.5 mass% or more and 2 mass% or less are preferable with respect to all the formation components of the inner layer 2. FIG. The upper limit of the content of the black dye is more preferably 1.5% by mass, and further preferably 1.3% by mass. On the other hand, the lower limit of the content of the black dye is more preferably 0.7% by mass, and still more preferably 0.9% by mass.

  When the inner layer 2 contains the above black dye, the black pigment used in combination with the black dye is preferably carbon black. In addition, the content of the black pigment used in combination with the black dye is not particularly limited, but is preferably 0.001% by mass or more and 0.2% by mass or less with respect to all the formation components of the inner layer 2. The upper limit of the content of the black pigment used in combination with the black dye is more preferably 0.15% by mass, and even more preferably 0.1% by mass. On the other hand, the lower limit of the content of the black pigment used in combination with the black dye is more preferably 0.005% by mass, and still more preferably 0.01% by mass.

  The total content of the black dye and the black pigment contained in the inner layer 2 is not particularly limited, but is 0.7% by mass or more and 2.001% by mass or less with respect to all the formation components of the inner layer 2. Is preferred. The upper limit of the total content of the black dye and the black pigment contained in the inner layer 2 is more preferably 1.6% by mass, and still more preferably 1.4% by mass. On the other hand, the lower limit of the total content of the black dye and the black pigment contained in the inner layer 2 is more preferably 0.8% by mass, and even more preferably 1.0% by mass. When the content of the black dye and the black pigment contained in the inner layer 2 is in the above range, the concealability is improved in combination with the black colorant contained in the outer layer 3 to be described later. Can show jetness.

(Outer layer)
The outer layer 3 is laminated on the outer surface of the inner layer 2. The outer layer 3 is formed with a synthetic resin as a main component. The main component of the outer layer 3 is not particularly limited, but an acrylic resin is preferable. The decorative sheet for injection molding 1 can improve weather resistance and contamination resistance by using an acrylic resin as the main component of the outer layer 3.

  As said acrylic resin, the polymer which contains acrylic monomers, such as acrylic acid and methacrylic acid, and these derivatives, as a monomer component is mentioned. Examples of the acrylic resin include methacrylic acid alkyl esters such as cyclohexyl methacrylate, t-butyl cyclohexyl methacrylate, and methyl methacrylate; methyl acrylate, ethyl acrylate, butyl acrylate, isopropyl acrylate, 2-acrylic acid 2- What polymerized the 1 type or multiple types of acrylic monomer chosen from acrylic acid alkylesters, such as ethylhexyl, is mentioned. This acrylic resin includes those obtained by copolymerizing an acrylic monomer and other monomer components. In the case of such copolymerization, the content (copolymerization ratio) of other monomer components is preferably 60% by mass or less, and preferably 50% by mass or less with respect to all monomer components constituting the acrylic resin. More preferred is 40% by mass or less.

  The acrylic resin is preferably a polymer containing methyl methacrylate as a monomer component. When the acrylic resin contains methyl methacrylate as a monomer component, the compatibility of the resulting acrylic resin is improved. Examples of the polymer containing methyl methacrylate as a monomer component include a homopolymer of methyl methacrylate, a copolymer of methyl methacrylate and another monomer, and the like. Examples of other monomers copolymerizable with methyl methacrylate include methacrylic acid alkyl esters other than methyl methacrylate; acrylic acid alkyl esters, α-hydroxymethyl acrylic acid alkyl esters; styrene; o-methyl styrene. Alkyl-substituted styrene such as p-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, p-tert-butylstyrene, α-alkyl-substituted styrene such as α-methylstyrene, α-methyl-p-methylstyrene, etc. Aromatic vinyl compounds; unsaturated nitriles such as acrylonitrile and methacrylonitrile; maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide; unsaturated carboxylic acid anhydrides such as maleic anhydride; acrylic acid and methacrylic acid Unsaturated carbo such as maleic acid Mention may be made of the acids and the like. As these other monomers, from the viewpoint of improving the flexibility and heat resistance of the resulting decorative sheet 1 for injection molding, α-hydroxymethyl acrylate alkyl esters, styrene, alkyl-substituted styrene, α-alkyl Substituted styrenes and unsaturated carboxylic acids are preferred, α-hydroxymethyl acrylate alkyl esters, styrene, α-alkyl substituted styrenes and unsaturated carboxylic acids are more preferred. Among them, α-hydroxymethyl acrylate methyl, styrene, α -More preferred are methylstyrene and methacrylic acid. As another monomer, when α-hydroxymethyl acrylic acid alkyl ester is used and copolymerized with methyl methacrylate, a lactone ring partially containing the polymer main chain is obtained by performing a dehydration reaction. In order to form, the heat resistance of the acrylic resin obtained improves especially. These monomers can be used individually by 1 type or in combination of multiple types. In such a copolymer of methyl methacrylate and another monomer, the content of other monomer components is preferably 50% by mass or less with respect to methyl methacrylate.

  As the other monomer copolymerizable with methyl methacrylate described above, alkyl acrylates are preferable. By using acrylic acid alkyl esters as other monomers, the heat resistance temperature of the resulting acrylic resin is improved, and the fluidity during molding is increased. In such a copolymer of methyl methacrylate and an alkyl acrylate, the content of the alkyl acrylate monomer component is 0% relative to the total monomer component from the viewpoint of improving heat resistance. 1 mass% or more and 15 mass% or less are preferable, 0.2 mass% or more and 14 mass% or less are more preferable, and 1 mass% or more and 12 mass% or less are more preferable.

  As the above-mentioned alkyl acrylates, methyl acrylate and ethyl acrylate are preferable because the effect of improving the fluidity at the time of molding described above can be remarkably obtained only by a small amount of copolymerization with methyl methacrylate.

  As said acrylic resin, isotactic polymethacrylic acid ester or syndiotactic polymethacrylic acid ester can also be used. As the acrylic resin, a commercially available product may be used as it is, or it can be produced from a commercially available product as a precursor.

  As a method for producing the acrylic resin, a conventionally known method can be employed, and for example, a polymerization method such as cast polymerization, bulk polymerization, suspension polymerization, solution polymerization, emulsion polymerization, anion polymerization or the like can be employed. . Bulk polymerization and solution polymerization without using a suspending agent or an emulsifier are preferred, and this can reduce the mixing of fine foreign substances. In the case of solution polymerization, an aromatic hydrocarbon solvent such as toluene can be used. In the case of bulk polymerization, the polymerization can be started by irradiation with free radicals generated by heating or ionizing radiation. Examples of the polymerization initiator used in the polymerization reaction include azo compounds such as azobisisobutyronitrile; organic peroxides such as benzoyl peroxide, lauroyl peroxide, and t-butylperoxy-2-ethylhexanoate. An oxide or the like can be used.

  In addition, when polymerization is performed under a temperature condition of 90 ° C. or higher, solution polymerization is generally employed. Among polymerization initiators soluble in organic solvents, those having a 10-hour half-life temperature of 80 ° C. or higher are used. It is preferable to use it. As such a polymerization initiator, specifically, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, cyclohexane peroxide, 2,5-dimethyl-2,5- Examples include di (benzoylperoxy) hexane, 1,1-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) isobutyronitrile, and the like. As the usage-amount of these polymerization initiators with respect to the said polymerization reaction, 0.005-5 mass parts is preferable with respect to 100 mass parts of all the monomers used for superposition | polymerization.

  In the polymerization reaction, a molecular weight regulator can be used as necessary. As this molecular weight regulator, those generally used in radical polymerization can be adopted. Specifically, for example, a mercaptan compound such as butyl mercaptan, octyl mercaptan, dodecyl mercaptan, 2-ethylhexyl thioglycolate can be used. These molecular weight regulators are preferably added in a concentration range such that the molecular weight of the acrylic resin is in a desired range.

  In addition, as a manufacturing method of the said acrylic resin, it is possible to use the method described, for example in Japanese Patent Publication No.63-1964. Moreover, as said acrylic resin, it can also be set as a ternary or more copolymer by copolymerizing methacrylic acid alkylester and / or acrylic acid alkylester, and one or more types of other monomers. it can.

  In the above ternary or higher copolymer, other monomer components copolymerized with the alkyl methacrylate and / or the alkyl alkyl ester include, for example, styrene, α-methylstyrene, o-methylstyrene, p- Aromatic vinyl compounds such as methylstyrene, o-ethylstyrene, p-ethylstyrene and pt-butylstyrene; Unsaturated nitriles such as acrylonitrile, methacrylonitrile and ethacrylonitrile; N-methylmaleimide, N- Maleimides such as ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide; (meth) acrylamides such as acrylamide, methacrylamide, N-methylacrylamide, butoxymethylacrylamide, N-propylmethacrylamide; maleic anhydride, italy anhydride Unsaturated carboxylic acid anhydrides such as acid; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, α-substituted acrylic acid, α-substituted methacrylic acid and maleic acid; methyl (meth) acrylate, ( (Meth) ethyl acrylate, (meth) acrylate n-propyl, (meth) acrylate n-butyl, (meth) acrylate t-butyl, (meth) acrylate n-hexyl, (meth) acrylate cyclohexyl, ( Chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2,3,4,5,6 (meth) acrylic acid -Unsaturated carboxylic acid alkyl esters such as pentahydroxyhexyl and 2,3,4,5-tetrahydroxypentyl (meth) acrylate It is possible to adopt the kind and the like.

  The weight average molecular weight (Mw) in terms of polymethyl methacrylate (PMMA) by gel permeation chromatography (GPC) of the acrylic resin is preferably from 10,000 to 400,000, more preferably from 40,000 to 300,000, More preferably, it is 10,000 to 200,000. By making Mw of the said acrylic resin into the said range, while improving the intensity | strength of the decorative sheet 1 for injection molding obtained, the workability and fluidity | liquidity of the decorative sheet 1 for injection molding improve. The molecular weight distribution (Mw / Mn) is preferably 1.8 or more and 3.0 or less, more preferably 1.8 or more and 2.7 or less, and further preferably 1.8 or more and 2.5 or less.

  The acrylic resin may be a mixture of two or more acrylic resins having different monomer component compositions, molecular weights, and the like. In this case, the weight average molecular weight means the average value.

The Vicat softening temperature of the acrylic resin is preferably 80 ° C. or higher and 120 ° C. or lower, more preferably 85 ° C. or higher, and further preferably 90 ° C. or higher. The glass transition temperature (Tg) of the acrylic resin is preferably 85 ° C. or higher, more preferably 90 ° C. or higher, and further preferably 95 ° C. or higher. Melt index of the above acrylic resin (ASTM
D1238; Condition I) is preferably 15 g / 10 min or less, more preferably 12 g / 10 min or less, and even more preferably 10 g / 10 min or less from the viewpoint of the strength of the resulting decorative sheet 1 for injection molding.

  When the acrylic resin is an acrylic resin that does not contain an aromatic vinyl monomer as a monomer component (hereinafter also referred to as “acrylic resin (1)”), the acrylic resin in the acrylic resin (1) As a content rate of a system-type monomer component, it is preferable that it is 40 mass% or more with respect to all the monomer components which comprise acrylic resin (1). Examples of the acrylic resin (1) include methacrylic acid esters such as cyclohexyl methacrylate, t-butylcyclohexyl methacrylate, and methyl methacrylate; methyl acrylate, ethyl acrylate, butyl acrylate, isopropyl acrylate, and acrylic acid. What polymerized 1 or more types of monomers chosen from acrylic acid esters, such as 2-ethylhexyl, can be used.

  The weight average molecular weight of the acrylic resin (1) is preferably from 50,000 to 200,000, and more preferably from 70,000 to 150,000. By setting the weight average molecular weight within the above range, the resulting decorative sheet for injection molding 1 is excellent in strength and excellent in molding processability and fluidity when molding the decorative sheet for injection molding 1.

  Furthermore, as an acrylic resin constituting the outer layer 3, an acrylic resin containing an aromatic vinyl monomer as a monomer component (hereinafter also referred to as “acrylic resin (2)”), and the aromatic vinyl When using together acrylic resin (1) which does not contain a system monomer as a monomer component, it is also possible to use other acrylic resin together. In this case, the content of the other acrylic resin is preferably 20 parts by mass or less and more preferably 10 parts by mass or less with respect to 100 parts by mass of the total resin constituting the outer layer 3. The content of the acrylic resin (1) is preferably 0.1 part by mass or more and 50 parts by mass or less, and 0.1 part by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the total resin constituting the outer layer 3. More preferably, it is 0.1 to 35 parts by mass. Furthermore, the content of the acrylic resin (2) is preferably 50 parts by mass or more and 99.9 parts by mass or less, and 60 parts by mass or more and 99.9 parts by mass with respect to 100 parts by mass of the total resin constituting the outer layer 3. The following is more preferable, and 65 parts by mass or more and 99.9 parts by mass or less are more preferable. By making content of the acrylic resin in the outer layer 3 into the said range, the heat resistance of the decorative sheet 1 for injection molding obtained can be improved. Moreover, the heat resistance of the decorative sheet for injection molding 1 can be increased by using an acrylic resin having a ring structure in the main chain.

  The outer layer 3 preferably contains a rubbery polymer together with the acrylic resin contained as a main component. Examples of such a rubbery polymer include butadiene-based ABS rubber and rubber particles having a single-layer or multi-layer structure such as acrylic, polyolefin-based, silicone-based, and fluororubber.

  The acrylic rubber may be composed only of an acrylic monomer, or may be composed of an acrylic monomer and another monomer. Examples of the acrylic monomer include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, allyl methacrylate, methyl acrylate, ethyl acrylate, i-propyl acrylate, and n-butyl acrylate. Examples of other monomers include aromatics such as styrene, α-methylstyrene, 2-methylstyrene, 4-methylstyrene, 2,4-diethylstyrene, 4-butoxystyrene, and N, N-dimethylaminostyrene. Vinyl compounds; α, β-ethylenically unsaturated nitrile compounds such as acrylonitrile, methacrylonitrile and vinylidene cyanide; Vinyl ester compounds such as vinyl acetate and vinyl propionate; Vinyl ether compounds such as ethyl vinyl ether, cetyl vinyl ether and hydroxybutyl vinyl ether Etc. These other monomers can be used alone or in admixture of two or more.

  The acrylic rubber may be crosslinked using a crosslinking agent. Examples of the crosslinking agent include sulfur; organic peroxides such as 2,4-dichlorobenzoyl peroxide, benzoyl peroxide, di-tert-butylperoxydiisopropylbenzene; tetramethylthiuram monosulfide, tetramethylthiuram disulfide, etc. Organic sulfur compounds; oxime compounds such as p-quinonedioxime and p, p′-dibenzoylquinonedioxime; and polyamines such as hexamethylenediamine carbamate. When a crosslinking agent is used, a vulcanization accelerator such as diphenyl guanidine, zinc dimethyldithiocarbamate, 2-mercaptobenzothiazole, dibenzothiazyl sulfide may be used as necessary.

  The average particle size of the rubber polymer is not particularly limited, but is preferably 0.1 μm or more and 0.6 μm or less. The upper limit of the average particle diameter of the rubber polymer is more preferably 0.5 μm, and further preferably 0.4 μm. On the other hand, the lower limit of the average particle diameter of the rubbery polymer is more preferably 0.2 μm, and still more preferably 0.3 μm. When the average particle diameter of the rubber polymer exceeds the upper limit, the transparency of the decorative sheet 1 for injection molding may be lowered. Conversely, if the average particle size of the rubbery polymer is less than the lower limit, the flexibility of the decorative sheet for injection molding 1 may be reduced.

  As content of the said rubbery polymer in the outer layer 3, 5 to 50 mass% is preferable, 10 to 45 mass% is more preferable, 20 to 40 mass% is further more preferable. There exists a possibility that the flexibility of the decoration sheet 1 for injection molding may fall that content of the said rubbery polymer is less than the said minimum. Conversely, if the content of the rubbery polymer exceeds the upper limit, the transparency of the injection molding decorative sheet 1 may be reduced.

  As said rubbery polymer, what has a multilayer structure is employable. This multi-layer structure includes, for example, a two-layer structure composed of a core-shell structure, a three-layer structure composed of a central hard layer, a soft layer, and an outermost hard layer, and an intermediate hard layer between the soft layer and the outermost hard layer. It is possible to adopt a four-layer structure or the like further having layers.

  As the two-layer structure, for example, a core-shell structure composed of a core layer made of a rubber-like polymer and a shell layer made of an acrylic resin-based glassy polymer can be used. The rubbery polymer used for the core layer is not particularly limited as long as it is rubbery at room temperature. For example, a rubbery polymer containing butadiene as a main component (for example, butadiene homopolymer, butadiene-aromatic). Group vinyl copolymer, etc.) and rubbery polymers (eg, butyl acrylate-styrene copolymer, 2-ethylhexyl acrylate-styrene copolymer, etc.) mainly composed of alkyl acrylate. . In addition, it is preferable to employ | adopt a butadiene-styrene copolymer, and intensity | strength, productivity, and transparency can be improved by this. The glassy polymer used for the shell layer is not particularly limited as long as it is a glassy acrylic polymer at room temperature. For example, a methyl methacrylate homopolymer, a methyl methacrylate-methyl acrylate copolymer, or the like is used. be able to.

  Examples of the rubbery polymer having a multilayer structure of three or more layers include those in which a soft layer made of a rubbery polymer and a hard layer made of a glassy polymer are laminated in three or more layers. As the rubbery polymer used for the soft layer and the glassy polymer used for the hard layer, those described for the rubber particles having the two-layer structure can be used.

  As long as the effects of the present invention are not impaired, the inner layer 2 and the outer layer 3 can be mixed with other polymers. Examples of other polymers include polyolefin resins such as polyethylene and polypropylene; polyamide resins; polyphenylene sulfide resins; polyether ether ketone resins; polyesters, polysulfones, polyphenylene oxides, polyimides, polyether imides, polyacetals, and the like. Plastic resins; and thermosetting resins such as phenol resins, melamine resins, silicone resins, and epoxy resins. Other polymers can be used singly or in combination.

  The average thickness of the outer layer 3 is not particularly limited, but is preferably 40 μm or more and 100 μm or less. The upper limit of the average thickness of the outer layer 3 is more preferably 90 μm and even more preferably 80 μm. On the other hand, the lower limit of the average thickness of the outer layer 3 is more preferably 50 μm and even more preferably 60 μm. When the average thickness of the outer layer 3 exceeds the above upper limit, there is a risk that the request for thinning the decorative sheet 1 for injection molding may be violated. On the other hand, when the average thickness of the outer layer 3 is less than the above lower limit, the content of the black colorant contained in the outer layer 3 may be reduced and a desired black color may not be achieved, and the decorative sheet for injection molding 1 There is a risk that the hardness and the like will decrease.

  The outer layer 3 contains a black colorant. Especially, the outer layer 3 contains both a black dye and a black pigment.

  Examples of the black dye contained in the outer layer 3 include azo dyes, acridine dyes, nitroso dyes, nitro dyes, stilbene azo dyes, ketoimine dyes, triphenylmethane dyes, xanthene dyes, quinoline dyes, methine / polymethine dyes, anthraquinone dyes. , Thiazole dye, indamine / indophenol dye, azine dye, oxazine dye, thiazine dye, sulfur dye, aminoketone / oxyketone dye, indigoid dye, phthalocyanine dye, perylene dye, perinone dye and the like. These dyes can be used alone or in combination of two or more. Moreover, you may express deep black by combining dyes, such as red, green, and yellow.

  Although it does not specifically limit as content of the said black type dye which the outer layer 3 contains, 0.5 mass% or more and 2 mass% or less are preferable with respect to all the formation components of the outer layer 3. The upper limit of the content of the black dye is more preferably 1.5% by mass, and further preferably 1.3% by mass. On the other hand, the lower limit of the content of the black dye is more preferably 0.7% by mass, and still more preferably 0.9% by mass.

  The black pigment contained in the outer layer 3 is preferably carbon black. Further, the content of the black pigment is not particularly limited, but is preferably 0.001% by mass or more and 0.2% by mass or less with respect to all the formation components of the outer layer 3. The upper limit of the content of the black pigment is more preferably 0.15% by mass, and still more preferably 0.1% by mass. On the other hand, the lower limit of the content of the black pigment is more preferably 0.005% by mass, and still more preferably 0.01% by mass.

  The total content of the black dye and the black pigment contained in the outer layer 3 is not particularly limited, but is 0.7% by mass or more and 2.001% by mass with respect to all the formation components of the outer layer 3. preferable. The upper limit of the total content of the black dye and the black pigment contained in the outer layer 3 is more preferably 1.6% by mass and even more preferably 1.3% by mass. On the other hand, the lower limit of the total content of the black dye and the black pigment contained in the outer layer 3 is more preferably 0.8% by mass, and even more preferably 1.0% by mass. When the content of the black dye and the black pigment contained in the outer layer 3 is in the above range, the concealability is improved in combination with the black colorant contained in the inner layer 2, and deep jetness. Can be played.

  The arithmetic average roughness (Ra) of the outer surface of the outer layer 3 is preferably 0.01 μm or more and 0.3 μm or less. Further, the upper limit of the arithmetic average roughness (Ra) of the outer surface of the outer layer 3 is more preferably 0.2, and still more preferably 0.1. When the arithmetic average roughness (Ra) of the outer surface of the outer layer 3 is in the above range, the outer surface is excellent in smoothness, and so-called piano black tone jetness can be achieved.

  The 60 ° glossiness of the outer surface of the outer layer 3 is preferably 70 or more and 90 or less. Further, the lower limit of the 60 ° glossiness of the outer layer 3 is more preferably 73, and even more preferably 75. When the 60 ° glossiness of the outer surface of the outer layer 3 is in the above range, the glossiness is excellent and so-called piano black tone jetness can be achieved.

  Further, the 20 ° glossiness of the outer surface of the outer layer 3 is preferably 65 or more and 85 or less. The lower limit of the 20 ° glossiness of the outer surface of the outer layer 3 is more preferably 70, and even more preferably 75. Furthermore, the 85 ° glossiness of the outer surface of the outer layer 3 is preferably 90 or more and 110 or less. As for the minimum of 85 degree glossiness of the outer surface of the outer layer 3, 95 is more preferable and 100 is more preferable. When the 20 ° glossiness and 85 ° glossiness of the outer surface of the outer layer 3 are within the above ranges, the glossiness is further improved and the jet blackness of piano black tone can be improved.

As a relationship between the linear expansion coefficient (α ₁ ) and glass transition temperature (Tg ₁ ) of the inner layer 2, the linear expansion coefficient (α ₂ ) and glass transition temperature (Tg ₂ ) of the outer layer 3, and room temperature, the following formula (1 ) And (2) are preferably 4 × 10 ⁻³ or less, more preferably 2 × 10 ⁻³ or less, and even more preferably 1 × 10 ⁻³ .
α ₁ * (Tg ₁ −room temperature) (1)
α ₂ * (Tg ₂ −room temperature) (2)

The relationship between the linear expansion coefficient (α ₁ ) and glass transition temperature (Tg ₁ ) of the inner layer 2, the linear expansion coefficient (α ₂ ) and glass transition temperature (Tg ₂ ) of the outer layer 3, and room temperature satisfies the above range. Thus, it is possible to reduce the internal stress when the inner layer 2 and the outer layer 3 are co-extruded and suitably prevent the occurrence of curling at the room temperature.

  The tensile strength of the decorative sheet 1 for injection molding is preferably 20 MPa or more, more preferably 30 MPa or more, and further preferably 40 MPa or more. Moreover, although it does not specifically limit as an upper limit of the tensile strength of the decorating sheet 1 for injection molding, For example, it can be 50 MPa. When the decorative sheet for injection molding 1 is in the above range, the decorative sheet for injection molding 1 is appropriately deformed during the injection molding. Therefore, the decorative sheet for injection molding 1 is a resin molded product. It can attach suitably to the outer surface.

The lightness (L ^* ) of the decorative sheet 1 for injection molding is preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less. When the brightness of the decorative sheet 1 for injection molding is in the above range, piano black tone jetness can be suitably achieved. The “lightness (L ^* )” is a value based on JIS-Z8729. The lightness (L ^* ) of the injection molding decorative sheet 1 is a value obtained by measuring the injection molding decorative sheet 1 from the outer layer side.

<Manufacturing method>
In the decorative sheet for injection molding 1, the inner layer 2 and the outer layer 3 are integrally laminated by an extrusion molding method. The decorative sheet 1 for injection molding is manufactured using, for example, a co-extruder (not shown) having a pair of extruders. Specifically, first, the forming material of the inner layer 2 is charged into one extruder, and the forming material of the outer layer 3 is charged into the other extruder. Next, the forming material of the inner layer 2 and the forming material of the outer layer 3 are supplied to the distribution block and distributed to a desired thickness. Then, the forming material of the inner layer 2 and the forming material of the outer layer 3 are distributed in a desired thickness, stacked in a multi-manifold die, and extruded into a film form from the tip of the multi-manifold die. The temperature settings for the pair of extruders and the multi-manifold die are appropriately selected in consideration of the melting point of the resin used.

<Advantages>
In the decorative sheet 1 for injection molding, the inner layer 2 and the outer layer 3 are integrally laminated by an extrusion molding method, so that the inner layer 2 and the outer layer 3 are bonded to each other with an adhesive as in the prior art. There is little possibility of foreign matter mixing with the outer layer 3. Moreover, since the decorative sheet for injection molding 1 contains the black colorant in the inner layer 2 or the outer layer 3, the inner layer 2 or the outer layer 3 has a design property on the printed surface as in the prior art. Sufficient black color can be exhibited by the contained black colorant.

  Since both the inner layer 2 and the outer layer 3 contain the black colorant, the decorative sheet for injection molding 1 can exhibit a more sufficient black color.

  Since the decorative sheet 1 for injection molding has a two-layer structure in which the inner layer 2 and the outer layer 3 are directly laminated, no other layer is provided between the inner layer 2 and the outer layer 3, so that the manufacturing cost is increased. The increase can be suppressed.

  Since the decorative sheet for injection molding 1 uses both a black dye and a black pigment as a black colorant, it can exhibit a jet blackness with higher design.

[Second Embodiment]
<Decorative sheet for injection molding>
The decorative sheet 11 for injection molding in FIG. 2 has an inner layer 12, an outer layer 3, and a hard coat layer 13. The decorative sheet 11 for injection molding is attached to the outer surface of a resin molded product molded by injection molding. In the decorative sheet 1 for injection molding, the inner layer 12 and the outer layer 3 are directly laminated. Moreover, about the outer layer 3, since it is the same as that of the decorating sheet 1 for injection molding of FIG. 1, the same number is attached | subjected and description is abbreviate | omitted.

(Inner layer)
The inner layer 12 is bonded to a resin molded product. The inner layer 12 is formed with a synthetic resin as a main component. The main component and average thickness of the inner layer 12 are the same as those of the inner layer 2 in FIG. The inner layer 12 is formed as a transparent layer that does not contain a black colorant.

(Hard coat layer)
A material for forming the hard coat layer 13 is not particularly limited, but a composition containing a triazine ring-containing (meth) acrylate prepolymer and organic fine particles is preferably used. Examples of the triazine ring-containing (meth) acrylate prepolymer include those synthesized in one step from an aminotriazine compound, paraformaldehyde and a hydroxyl group-containing (meth) acrylate. The organic fine particles include fine particles synthesized by an emulsion polymerization method. Although it does not specifically limit as an average molecular weight of the said triazine ring containing (meth) acrylate prepolymer, 200 or more and 20000 or less are preferable. When the said average molecular weight exceeds the said upper limit, a viscosity becomes high and a possibility that coating may become difficult becomes high. Conversely, when the average molecular weight is less than the lower limit, there is a high possibility that sufficient hardness cannot be obtained.

  The aminotriazine compound has a structure in which an amino group is bonded to each of three carbon atoms of the triazine ring, and means aminotriazine or a derivative thereof. Examples of the aminotriazine include melamine. Examples of the aminotriazine derivative include benzoguanamine, acetoguanamine, cyclohexanecarboguanamine, cyclohexenecarboguanamine, norbornanecarboguanamine, and nobornenecarboguanamine.

  Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate. In addition, the hydroxyl group-containing (meth) acrylate may optionally include a compound having an ethylenically unsaturated bond having at least one hydroxysyl group, such as 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl acrylate. , Polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, trimethylpropane mono (meth) acrylate, trimethylolpropane di (meth) acrylate, allyl alcohol, ethylene glycol allyl ether, glycerin (mono, di) allyl ether N-methylol (meth) acrylamide or a mixture thereof can be added.

  Does the synthesis of the triazine ring-containing (meth) acrylate prepolymer proceed by the formation of a methylol group by the addition reaction of formaldehyde to an aminotriazine compound and the condensation reaction of the methylol group and the hydroxyl group of the hydroxyl group-containing (meth) acrylate? Alternatively, formaldehyde hemiacetal is produced from hydroxy group-containing (meth) acrylate and formaldehyde, and this formaldehyde hemiacetal and aminotriazine compound are condensed and proceed. The degree of progress of the condensation reaction can be judged by the amount of water removed by these condensation reactions, and this condensation reaction is controlled by grasping this amount of water over time and stopping the water distillation at a predetermined stage. Can do.

  Examples of the organic fine particles include organic fine particles such as styrene resins, styrene-acrylic copolymer resins, and acrylic resins synthesized by an emulsion polymerization method. By synthesizing the organic fine particles by an emulsion polymerization method, it is possible to add a cross-linking agent, suppress variations in the primary particle diameter, and promote uniformity of in-plane flexibility.

  The average primary particle diameter of the organic fine particles is not particularly limited, but is preferably 80 nm or more and 500 nm or less. When the average primary particle diameter of the organic fine particles exceeds the upper limit, the haze increases and the visibility is likely to decrease. Conversely, when the average primary particle diameter of the organic fine particles is less than the lower limit, the synthesis of the organic fine particles is likely to be difficult. The average primary particle diameter refers to the diameter of a single particle that has not been agglomerated. For spherical particles, the diameter is the same, and for non-spherical particles, the arithmetic average of the major axis diameter and the minor axis diameter. Indicates a value, which is a value measured by an electron microscope.

  The amount of the organic fine particles added to 100 parts by weight of the triazine ring-containing (meth) acrylate prepolymer is not particularly limited, but is preferably 1 part by weight or more and 50 parts by weight or less, more preferably 10 parts by weight or more and 30 parts by weight or less. . When the addition amount exceeds the upper limit, the hardness cannot be sufficiently improved, and the possibility that the addition amount is increased. On the other hand, when the addition amount is less than the lower limit, the flexibility is likely to be lowered.

  Further, as a material for forming the hard coat layer 13, a urethanized triazine ring-containing (meth) acrylate prepolymer obtained by reacting an unreacted hydroxyl group remaining in the triazine ring-containing (meth) acrylate prepolymer with an isocyanate compound, and an organic material. A composition containing fine particles is also preferably used. Examples of the organic fine particles include organic fine particles such as styrene resins, styrene-acrylic copolymer resins, and acrylic resins synthesized by an emulsion polymerization method. The average primary particle diameter of the organic fine particles and the amount of the organic fine particles added to 100 parts by weight of the triazine ring-containing (meth) acrylate prepolymer are the same as described above. The urethanized triazine ring-containing (meth) acrylate prepolymer can be further improved in flexibility by urethanization.

  Examples of the isocyanate compound include aliphatic, alicyclic, aromatic, araliphatic isocyanate and modified products thereof.

  Examples of the aliphatic isocyanate include hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMDI), and lysine diisocyanate (LDI). Examples of the alicyclic isocyanate include dicyclohexylmethane diisocyanate (HMDI), isophorone diisocyanate (IPDI), 1,4-cyclohexane diisocyanate (CHDI), hydrogenated xylylene diisocyanate (HXDI), hydrogenated tolylene diisocyanate (HTDI), and the like. Is mentioned. Examples of the aromatic isocyanate include tolylene diisocyanate (TDI), 4,4 ′ (or 2,4 ′)-diphenylmethane diisocyanate (MDI), naphthalene diisocyanate (NDI), xylylene diisocyanate (XDI), and tolidine diisocyanate. (TODI), p-phenylene diisocyanate (PPDI) and the like. Examples of the araliphatic isocyanate include α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDI) and the like.

  Examples of modified products of the above aliphatic, alicyclic, aromatic or araliphatic isocyanate compounds include a carbodiimide group, a uretdione group, a uretoimine group, a burette group, an isocyanurate group, etc. And modified compounds. In addition, the said isocyanate compound may use only 1 type, and may use 2 or more types together.

  Moreover, in order to promote reaction with the isocyanate group of the said isocyanate compound, an organotin type | system | group urethanation catalyst can be used. The organotin-based urethanization catalyst is not particularly limited as long as it is generally used in the urethanization reaction, and is dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dialkylmalate, tin stearate, octyl. An acid tin etc. are mentioned.

  The amount of the organotin urethanization catalyst used is not particularly limited, but is preferably 0.005 wt% or more and 3 wt% or less. When the usage-amount of the said organotin type | system | group urethanization catalyst exceeds the said upper limit, there exists a possibility that reaction control may become difficult by the heat_generation | fever at the time of urethane reaction. On the contrary, when the usage-amount of the said organotin type | system | group urethanization catalyst is less than the said minimum, a possibility that a urethane reaction may not fully advance becomes high.

  The hard coat layer 13 is preferably formed through mixing or polymerization using a polyfunctional polymerizable monomer as a reactive compound.

  The polyfunctional polymerizable monomer has at least two (meth) acryloyl groups, vinyl groups, and allyl groups in the molecule. Among the polyfunctional polymerizable monomers, those having a (meth) acryloyl group are preferable. Such a polyfunctional polymerizable monomer having a (meth) acryloyl group has very high radical reactivity, and is superior in terms of fast curing and high hardness.

  Examples of the polyfunctional polymerizable monomer having a (meth) acryloyl group include dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) ) Acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, hexanediol di (meth) acrylate, diethylene glycol di (meth) Polyfunctional (meth) acrylates such as acrylate are listed. These can be used alone or in combination.

  The average thickness of the hard coat layer 13 is not particularly limited, but is preferably 1 μm or more and 20 μm or less. The upper limit of the average thickness of the hard coat layer 13 is more preferably 15 μm and even more preferably 10 μm. Further, the lower limit of the average thickness of the hard coat layer 13 is more preferably 3 μm, and further preferably 5 μm. When the average thickness of the hard coat layer 13 exceeds the above upper limit, it is contrary to the demand for thinning and the flexibility may be lowered. Conversely, when the average thickness of the hard coat layer 13 is less than the above lower limit, there is a possibility that desired hardness cannot be obtained.

  Note that the arithmetic average roughness (Ra) of the outer surface of the hard coat layer 13 and the 60 ° gloss, 20 ° gloss, and 85 ° gloss of the outer surface of the hard coat layer 13 are values of the outer surface of the outer layer 3 in FIG. It is the same.

Moreover, the tensile strength and lightness (L ^* ) of the injection molding decorative sheet 11 are the same as those of the injection molding decorative sheet 1 of FIG.

<Manufacturing method>
As a method for producing the decorative sheet 11 for injection molding, generally, (a) a step of forming a laminate composed of the inner layer 12 and the outer layer 3, and (b) a hard coat layer on the outer surface of the outer layer 3 of the laminate. 13 is formed. As said (a), the manufacturing method similar to the decorating sheet 1 for injection molding of FIG. 1 is mentioned. Moreover, as said (b), the forming material of the hard-coat layer 13 is apply | coated to the outer surface of the outer layer 3, and the method of drying and hardening is mentioned.

  Examples of a method for applying the material for forming the hard coat layer 13 to the outer surface of the outer layer 3 include known methods such as a gravure coating method, a bar coating method, a knife coating method, a roll coating method, a blade coating method, and a die coating method.

  Moreover, as a method of hardening the forming material of the hard-coat layer 13 apply | coated to the outer surface of the outer layer 3, the method of irradiating and irradiating active energy rays, such as an ultraviolet-ray and an electron beam, is mentioned. In the case of curing by ultraviolet rays, a photopolymerization initiator is contained in the material for forming the hard coat layer 13.

  Examples of the photopolymerization initiator include benzophenone, benzyl, Michler's ketone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-diethoxyacetophenone, benzyldimethyl ketal. 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4 -(Methylthio) phenyl] -2-morpholinopropanone-1, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, bis (cyclopenta Dienyl) -bis (2,6 Difluoro-3- (pyr-1-yl) titanium, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc. Note that these compounds may be used alone or in combination.

As the ultraviolet irradiation device, a known device such as a high-pressure mercury lamp or a metal halide lamp can be used. The ultraviolet radiation energy, preferably ^{100~2000mJ / cm 2, 300~700mJ / cm} 2 is more preferable. Moreover, the scratch resistance can be further improved by performing the ultraviolet irradiation in a nitrogen gas atmosphere.

  A conventionally known curing device can be used as the electron beam irradiation device. The electron beam irradiation dose is preferably 10 kGy to 200 kGy, and more preferably 30 kGy to 100 kGy.

<Advantages>
Since the injection molding decorative sheet 11 further includes a hard coat layer 13 laminated on the outer surface of the outer layer 3, for example, after the injection molding decorative sheet 11 is attached to the outer surface of the resin molded product, etc. The hard coat layer 13 can accurately prevent the outer surface of the outer layer 3 from being damaged.

[Third embodiment]
<Sheet laminate for injection molding>
The injection-molded sheet laminate 21 in FIG. 3 includes an injection-molding decorative sheet 1 and a release sheet 22. The decorative sheet for injection molding 1 has an inner layer 2 and an outer layer 3. About the inner layer 2 and the outer layer 3, since it is the same as that of the injection molding decorating sheet 1 of FIG. 1, the same number is attached | subjected and description is abbreviate | omitted.

(Release sheet)
The release sheet 22 is detachably laminated on the outer surface of the outer layer 3 of the injection molding decorative sheet 1. The release sheet 22 has a base film. This base film is formed of various materials having heat resistance, mechanical strength that can withstand manufacturing, solvent resistance, and the like. Examples of the main component for forming the base film include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyolefin resins such as polyethylene, polypropylene, and polymethylpentene, polyamide resins such as nylon 6, and polyvinyl chloride. Vinyl resins, acrylic resins such as polymethyl methacrylate, and synthetic resins such as cellulose resins such as polycarbonate, cellophane, and cellulose acetate. Of these, polyester resins are preferable in terms of heat resistance and mechanical strength, and polyethylene terephthalate is particularly preferable.

  The base film may be either a stretched film or an unstretched film, but is preferably stretched in a uniaxial direction or a biaxial direction from the viewpoint of improving strength. The base film may be a single layer or a multilayer. In addition, additives, such as a filler, a plasticizer, a coloring agent, and an antistatic agent, may be added to the base film as necessary.

  Although it does not specifically limit as average thickness of the said base film, 20 micrometers or more and 1 mm or less are preferable. The upper limit of the average thickness of the base film is more preferably 800 μm, and even more preferably 500 μm. On the other hand, the lower limit of the average thickness of the base film is more preferably 60 μm and even more preferably 100 μm. If the average thickness of the base film exceeds the upper limit, the release sheet 22 may lack flexibility. Conversely, when the average thickness of the base film is less than the lower limit, the strength of the release sheet 22 may be lacking.

  Moreover, as for the release sheet 22, the release layer may be laminated | stacked on the inner surface side (lamination surface side with the outer layer 3) of the said base film. This release layer is provided in order to improve the peelability between the release sheet 22 and the decorative sheet for injection molding 1, and when the peelability between the base film and the decorative sheet for injection molding 1 is high. Is not necessary. Examples of the material for forming the release layer include silicone, melamine, fluorinated polymer, and synthetic resin. Examples of the synthetic resin include melamine resin, urea resin, polyurethane resin, polyester resin, phenol resin, epoxy resin, aminoalkyd resin, and the like. The release layer is formed by applying the release layer forming material on a base film by a known method such as a gravure coating method, a roll coating method, a comma coating method, or a lip coating method, followed by drying and curing. can do. In forming the release layer, the laminated surface may be subjected to corona treatment or easy adhesion treatment.

  The release layer may contain a crosslinking agent. Examples of the crosslinking agent contained in the release layer include epoxy crosslinking agents, isocyanate crosslinking agents, methylol crosslinking agents, chelating crosslinking agents, aziridine crosslinking agents, melamine crosslinking agents, and polyvalent metal chelating crosslinking agents. Agents and the like.

  The content of the crosslinking agent is not particularly limited, but is preferably 0.5 parts by mass or more and 20 parts by mass or less, and particularly preferably 2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the main component of the release layer. . When the content of the crosslinking agent is within the above range, a stable high molecular weight product can be obtained.

  Examples of organic solvents include aliphatic hydrocarbons such as hexane, heptane and cyclohexane, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, ethanol, propanol and butanol, ketones such as methyl ethyl ketone, 2-pentanone and isophorone. And esters such as ethyl acetate, butyl acetate and methoxypropyl acetate, cellosolve solvents such as ethyl cellosolve, and glycol solvents such as methoxypropanol, ethoxypropanol and methoxybutanol. These organic solvents can be used alone or in combination.

  A filler, a softener, an antioxidant, an ultraviolet absorber, a tackifier, an antistatic agent, and the like can be added to the release layer as necessary.

  Although it does not specifically limit as average thickness of the said mold release layer, 10 micrometers or more and 50 micrometers or less are preferable. The upper limit of the average thickness of the release layer is more preferably 45 μm and even more preferably 30 μm. The lower limit of the average thickness of the release layer is more preferably 15 μm and even more preferably 20 μm. When the average thickness of the release layer exceeds the above upper limit, there is a risk that it will be contrary to the demand for thinning. On the contrary, when the average thickness of the release layer is less than the lower limit, the release property may be deteriorated.

<Advantages>
Since the injection-molded sheet laminate 21 includes the injection-molding decorative sheet 1 and a release sheet 22 that is detachably laminated on the outer surface of the outer layer 3 of the injection-molding decorative sheet 1. The release sheet 22 is arranged so as to face the mold surface of the mold, the molten resin is injected into the mold, and the mold release sheet 22 is peeled off after the resin is cured. An injection molded product to which the decorative sheet 1 is attached can be obtained, and this injection molded product can exhibit a sufficient black color with little possibility of foreign matter mixing inside the decorative sheet for injection molding 1.

[Fourth embodiment]
<Injection molded products>
The injection molded product 31 in FIG. 4 includes an injection molding decorative sheet 1 and a resin molded product 32. In the injection molded product 31, the decorative sheet 1 for injection molding is attached to the outer surface of the resin molded product 32.

(Resin molding)
The material for forming the resin molded product 32 is not particularly limited, and polyolefin resin, polycarbonate resin, ABS resin, urethane resin, polyester resin, polystyrene resin, vinyl chloride resin, polyamide resin, and the like. Is mentioned.

<Manufacturing method>
As a method of attaching the decorative sheet for injection molding 1 to the resin molded product 32, insert molding, in-mold molding, or the like is preferable. As a method of attaching the injection molding decorative sheet 1 to the resin molded product 32, for example, (a) a process of arranging the injection molding decorative sheet 1 in an injection mold, and (b) vacuum molding. And a step of closely attaching the decorative sheet for injection molding 1 to the inner surface of the mold, and (c) a step of injection molding the forming material of the resin molded product 32 in the mold.

<Advantages>
Since the injection-molded decorative sheet 1 is attached to the outer surface of the injection-molded product 31, the injection-molded decorative sheet 1 is less likely to be mixed with foreign matter and can exhibit a sufficient black color. .

[Other Embodiments]
In addition, the decorative sheet for injection molding, the sheet laminate for injection molding, and the injection molded product of the present invention can be implemented in variously modified and improved modes in addition to the above mode. In addition, the configurations of the above-described embodiments according to the present invention can be implemented in appropriate combination.

  For example, the decorative sheet for injection molding may contain a black color material only in the inner layer. The black colorant when the black colorant is contained only in the inner layer can be the same as the case where the black colorant is contained only in the outer layer. When the decorative sheet for injection molding has a hard coat layer, a release sheet may be laminated on the outer surface of the hard coat layer.

  The decorative sheet for injection molding may have another layer between the inner layer and the outer layer or between the outer layer and the hard coat layer. Further, the decorative sheet for injection molding may have an adhesive layer on the inner surface side of the inner layer in order to improve the adhesiveness with the resin molded product.

  As described above, the decorative sheet for injection molding, the sheet laminate for injection molding, and the injection molded product of the present invention are less likely to be mixed with foreign matter and can exhibit a sufficient black color. It is suitably used for decorating the surfaces of products, cosmetic containers, miscellaneous goods, automobile interior parts and the like.

DESCRIPTION OF SYMBOLS 1 Decorative sheet for injection molding 2 Inner layer 3 Outer layer 11 Decorative sheet for injection molding 12 Inner layer 13 Hard coat layer 21 Sheet laminate for injection molding 22 Release sheet 31 Injection molded product 32 Resin molded product

Claims (13)

A decorative sheet for injection molding made of resin attached to the outer surface of a resin molded product molded by injection molding,
The inner layer bonded to the resin molded product and the outer layer laminated on the outer surface side of the inner layer have a multilayer structure integrally laminated by an extrusion molding method,
The decorative sheet for injection molding, wherein the inner layer or the outer layer contains a black colorant.   The decorative sheet for injection molding according to claim 1, wherein both the inner layer and the outer layer contain the black colorant.   The decorative sheet for injection molding according to claim 1 or 2, having a two-layer structure in which the inner layer and the outer layer are directly laminated.   The decorative sheet for injection molding according to claim 1, further comprising a hard coat layer laminated on an outer surface of the outer layer.   The decorative sheet for injection molding according to any one of claims 1 to 4, wherein the arithmetic average roughness (Ra) of the outer surface is 0.01 µm or more and 0.3 µm or less.   The decorative sheet for injection molding according to any one of claims 1 to 5, wherein the outer surface has a 60 ° glossiness of 70 or more and 90 or less.   The decorative sheet for injection molding according to any one of claims 1 to 6, wherein both a black dye and a black pigment are used as the black colorant.   The decorative sheet for injection molding according to any one of claims 1 to 7, wherein a main component of the outer layer is an acrylic resin.   The decorative sheet for injection molding according to claim 8, wherein the tensile strength is 20 MPa or more.   The decorative sheet for injection molding according to any one of claims 1 to 9, wherein a main component of the inner layer is the same type of resin as a main component of the resin molded product. As the relationship between the linear expansion coefficient (α ₁ ) and glass transition temperature (Tg ₁ ) of the inner layer, the linear expansion coefficient (α ₂ ) and glass transition temperature (Tg ₂ ) of the outer layer, and room temperature, the following formula (1 11) The difference between the values of (2) and 4 × 10 ⁻³ or less is the decorative sheet for injection molding according to any one of claims 1 to 10.
α ₁ * (Tg ₁ −room temperature) (1)
α ₂ * (Tg ₂ −room temperature) (2) The decorative sheet for injection molding according to any one of claims 1 to 11,
A sheet laminate for injection molding comprising: a release sheet that is detachably laminated on the outer surface side of the outer layer of the decorative sheet for injection molding.   An injection molded product in which the decorative sheet for injection molding according to any one of claims 1 to 12 is attached to an outer surface.

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