JP3045766B2 - Manufacturing method of injection molded products - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a molded product formed by injection molding such as a housing or a stationery of OA equipment and home appliances,
In particular, the present invention relates to a method for manufacturing a molded product in a field where painting or the like is conventionally performed in a post-process as an improvement in appearance and tactile sensation.

(Prior Art) In order to impart soft touch feeling (suede-like) to injection molded products such as housings and stationery of OA equipment and home appliances, paints having a soft touch feeling (suede-like) have been generally used. However, when a soft touch feeling is imparted to the surface of an article by using a paint, it is necessary to adjust the viscosity and concentration of the paint, which complicates the operation. In particular, in the case of a paint using an organic solvent, contamination of the working environment and safety and health problems occur.

In order to solve these problems, a sheet-like suede-like coating material has been proposed instead of a paint. For example, Japanese Patent Application Laid-Open No. 2-41243 discloses a suede having a matte paint film prepared by adding a bead pigment to an ionizing radiation-curable resin on a base film made of ABS resin, polypropylene or the like. Tone sheets have been proposed.

(Problems to be Solved by the Invention) However, in such a sheet, since the coating film is formed of a resin cross-linked by an electron beam, the spreadability of the entire sheet is poor. Therefore, for example, when injection-molding a deep-drawing molded product, the sheet cannot be sufficiently formed into a female shape because the sheet cannot be sufficiently stretched, and the sheet may be broken when the resin is injected. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has an object to provide a method for producing an injection molded product capable of forming a film having a soft touch feeling on the surface of a deep drawn product without any problem. is there.

(Means for Solving the Problems) The method for producing an injection-molded article of the present invention comprises: (e) having a plurality of functional groups such as a hydroxyl group, an amino group and a carboxyl group in a molecule, and having a weight average molecular weight of 50,000 to 1,000,000. Acrylic resin which is solid at room temperature or (h) hydroxyl group in molecule,
It has a plurality of functional groups such as amino group and carboxyl group and (meth) acryloyl group, and has a weight average molecular weight of 50,000 to 1,
(B) an acrylic resin that is 000,000 and is solid at room temperature;
A low molecular weight product having a (meth) acryloyl group in a molecule, (c) a photoinitiator, and (d) elastic beads;
(F) an uncured or uncured resin composition formed of a photocurable resin composition containing as a main component at least one crosslinking agent selected from the group consisting of an isocyanate-based crosslinking agent, a melamine-based crosslinking agent, and an epoxy-based crosslinking agent; A step of applying the photocurable sheet in a semi-cured state to the inner surface of a mold by vacuum and / or pressure molding, and injecting molding resin into the mold to form a coated body covered with the photocurable sheet. And a step of irradiating the coating with light to cure the photocurable sheet, thereby achieving the above object.

 The details are as follows.

The photocurable sheet used in the present invention includes the following.

(E) having a plurality of functional groups such as a hydroxyl group, an amino group and a carboxyl group in the molecule, and having a weight average molecular weight of 50,000 to 1,
(B) an acrylic resin that is 000,000 and is solid at room temperature;
A group consisting of a low molecular weight compound having a (meth) acryloyl group in a molecule, (c) a photoinitiator, (d) an elastic bead, and (f) an isocyanate-based crosslinking agent, a melamine-based crosslinking agent, and an epoxy-based crosslinking agent. A curable sheet formed of a photocurable resin composition containing, as a main component, at least one crosslinking agent selected from the group consisting of:

(H) an acrylic resin having a plurality of functional groups such as a hydroxyl group, an amino group and a carboxyl group and a (meth) acryloyl group in a molecule, and having a weight average molecular weight of 50,000 to 1,000,000 and being solid at ordinary temperature; (C) a photoinitiator, and (d) a low molecular weight substance having a (meth) acryloyl group therein.
It is formed of a photo-curable resin composition comprising, as main components, elastic beads and (f) at least one type of crosslinking agent selected from the group consisting of isocyanate-based crosslinking agents, melamine-based crosslinking agents, and epoxy-based crosslinking agents. Curable sheet.

(E) Acrylic resin which has a plurality of functional groups such as hydroxyl group, amino group and carboxyl group in the molecule contained in the photocurable sheet, has a weight average molecular weight of 50,000 to 1,000,000 and is solid at room temperature is, for example, (Meth) acrylate monomers having a carboxyl group such as, (meth) acrylic acid and (meth) acrylate monomers having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate And a monomer having at least one kind of functional group among (meth) acrylate monomers having an amino group such as 2-aminoethyl (meth) acrylate and 3-aminopropyl (meth) acrylate; Reacts with (meth) acrylate, styrene derivative monomer, maleic acid monomer, etc. Can be in the presence of initiator (various peroxides and chain transfer agent) obtained by copolymerizing.

The (h) molecule contained in the photocurable sheet has a plurality of functional groups such as a hydroxyl group, an amino group and a carboxyl group, and a plurality of (meth) acryloyl groups, and has a weight average molecular weight of 50,0.
Acrylic resin in a solid state at room temperature is 00 to 1,000,000,
For example, a (meth) acrylic acid having a carboxyl group such as (meth) acrylic acid and a (meth) acrylic acid ester monomer having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate A (meth) acrylate monomer having an amino group such as, 2-aminoethyl (meth) acrylate, 3-aminopropyl (meth) acrylate,
(Meth) acrylate monomer having aziridinyl such as 2- (1-aziridinyl) ethyl (meth) acrylate and 2- (1-aziridinyl) butyl (meth) acrylate; and epoxy group such as glycidyl (meth) acrylate Among the (meth) acrylate monomers and the like, a monomer having at least one functional group and another (meth) acrylate, a styrene derivative monomer, a maleic acid monomer or the like are used as reaction initiators (various peroxides). Or a chain transfer agent) by adding the monomer having a (meth) acryloyl group to an acrylic copolymer having a functional group which can be obtained by copolymerization in the presence of a (meth) acryloyl group.

The weight average molecular weight (Mw) of these acrylic resins (e) and (h) can be changed depending on the conditions when a polymerization reaction is performed using a reaction initiator. The acrylic resin used in the present invention has a weight average molecular weight of 50,0.
Objects ranging from 00 to 1,000,000 are selected. When the weight average molecular weight is less than 50,000, it is difficult for the obtained sheet to maintain its shape, and it is not possible to obtain sufficient elongation with respect to stretching during the sticking operation, and there is a possibility that cracks may occur. When the weight average molecular weight exceeds 1,000,000, it becomes difficult to dissolve in a solvent, and it becomes difficult to prepare a sheet from the photocurable resin composition. For example, when a sheet is prepared by solvent casting, the viscosity of the solvent increases, so that only a low concentration of the resin can be cast, and it is difficult to increase the thickness of the sheet. These acrylic resins have a Tg (glass transition point) of-from the relationship between the hardness after curing of the sheet and the soft touch feeling (suede feeling).
Those in the range of 20 ° C to 100 ° C are preferred. Acrylic resin is
Different kinds of substances may be used in combination within these molecular weight ranges. The acrylic resins (e) and (h) have a functional group such as a hydroxyl group, an amino group and a carboxyl group, and thus are cross-linked by the cross-linking agent, whereby the flexibility, spreadability, and extensibility of the sheet are reduced. Even when deep drawing is performed, the sheet is satisfactorily molded and adhered to the shape of the mold without breaking even when performing deep drawing, and the sheet is not broken when the resin is injection-molded. The functional group value of the reactive acrylic resin is usually OH value and NH ₂ value (NH ₂ value:
The amount of NH ₂ groups added during polymerization is calculated in the same way as the OH value, or the amount of NH ₂ groups is determined by reacting NH ₂ groups with nitrous acid and converted to OH groups, and the COOH value (COOH value: COOH group added during polymerization) The amount of
Calculated in the same manner as the OH value or the value obtained by titrating the COOH group with KOH) is preferably in the range of 2 to 50. When the functional group value is 2 or less, improvement in flexibility cannot be expected. Also,
If the functional group value is 50 or more, sufficient elongation of the sheet cannot be obtained.

The (b) low molecular weight compound having a (meth) acryloyl group in the molecule contained in the sheet includes, for example, methyl (meth) acrylate, ethyl (meth) acrylate, benzyl (meth) acrylate, 2-ethoxyethyl (meth) ) Monofunctional type such as acrylate, phenoxydiethylene glycol (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) ) Polyfunctional such as acrylate, trimethylpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate There is a type. In addition, there are oligomers such as polyester acrylate, polyurethane acrylate, epoxy acrylate, polyether acrylate, oligoacrylate, alkyd acrylate, and polyol acrylate.

The elastic beads (d) have a property of recovering elasticity when the beads are opened after being pressed until their shape is deformed. As a material for forming the elastic beads, for example,
Examples include polyurethane, acrylic-urethane copolymer, polyvinylidene chloride, copolymer of vinylidene chloride with other monomers, polystyrene, styrene-isoprene copolymer and the like. Elastic beads have a maximum particle size distribution of 1
50 μm range to 100 parts by weight of solid content of resin
It is preferable to add 0 to 400 parts by weight. If the particle size of the elastic beads is less than 1 μm, a sufficient soft touch feeling (suede feeling) cannot be imparted to the obtained sheet, and if the particle size exceeds 50 μm, cracks are likely to be generated on the surface of the sheet when the sheet is stretched. . If the addition amount of the elastic beads is less than 20 parts by weight, a sufficient soft touch feeling (suede feeling) cannot be obtained, and the addition amount is 40%.
If the amount is more than 0 parts by weight, cracks tend to occur on the surface during sheet stretching. Further, the elastic beads are not limited to one kind, and two or more kinds may be used in combination.

Since the above low molecular weight substance has an effect of plasticizing the reactive acrylic resin, the amount added is almost related to the Tg of the acrylic resin and the viscosity of the low molecular weight substance to be added. For example,
When using an acrylic resin having a Tg of 60 to 80 ° C, the viscosity is 50
10 to 150 parts by weight, low viscosity of 5 cps (25 ° C) or less
It is preferable to add 50 to 300 parts by weight of a low molecular weight substance having a molecular weight of 00 cps (25 ° C.) or higher. If the amount is small, sufficient abrasion resistance and chemical resistance after curing of the sheet cannot be obtained. If the amount of addition is large, the handleability of the sheet becomes poor. The above low molecular weight substances may be used in combination of different kinds.

The isocyanate-based crosslinking agent is an isocyanate compound having two or more isocyanate groups in a molecule, for example, tolylene diisocyanate, diphenylmethane isocyanate, naphthalene diisocyanate, tolidine diisocyanate, triphenylmethane triisocyanate, tris (isocyanatephenyl) thio. Monomers such as phosphite, P-phenylene diisocyanate, xylylene diisocyanate, bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate, or trimethylol of these monomers Propane adduct, isocyanurate modified, biuret modified Carbodiimide-modified products, urethane modified product, there is allophanate modified product, or the like.

As melamine-based cross-linking agents, urea including melamine,
Thiourea, guanidine, guanamine, acetoguanamine, benzoguanamine, dicyandiamide, trimethylolmelamine, hexamethylolmelamine, dimethylolurea dimethylolguanidine, dimethylolacetoguanamine, which is obtained by reacting a material having a polyfunctional amino group such as guanamine with formaldehyde. Examples include etherified melamine resins obtained by reacting dimethylol benzoguanamine or the like with an alcohol such as butyl alcohol or propyl alcohol.

Examples of the epoxy-based crosslinking agent include a glycidyl compound of a polyhydric alcohol having a plurality of epoxy groups, and are usually used together with a Lewis acid catalyst. The Lewis acid is preferably microencapsulated to delay the reaction. For example, diglycidyl esters of butadiene dioxide, hexaazine dioxide and phthalic acid,
Diglycidyl ether of bisphenol-A, diglycidyl ether of bisphenol-f, triglycidyl ether amine of paraaminophenol, diglycidyl ether of aniline, tetraglycidyl ether of phenylenediamine, diglycidyl ether of sulfonamide, triglycidyl ether of glycerin, etc. Glycidyl compounds, polyether-modified diglycidyl, polyester-modified diglycidyl, urethane-modified diglycidyl compounds (polymers), vinylcyclohexene dioxide, dicyclopentadiene dioxide, and the like.

The amount of these crosslinking agents added depends on the functional group value of the acrylic resin:
The functional group value of the crosslinking agent is preferably about 1: 0.7 to 1.3. However, actually, not only the reaction with the functional group of the acrylic resin due to the reactivity with the acrylic resin used, but also the reaction between the cross-linking agents, for example, between the melamine-based cross-linking agents, the melamine-based cross-linking agent and the epoxy-based cross-linking agent occurs. It is preferable to determine after conducting a preliminary experiment.

As the photoinitiator (c), a commonly used photoinitiator can be used, and for example, a photoinitiator of benzoin alkyl ether type, acetophenone type, benzophenone type, thioxanthone type, acylphosphine oxide type or the like is suitably used. Benzoin ethers include benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether and the like. In the acetophenone system, 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylpropiophenone, p
-Ter-butyltrichloroacetophenone and the like. Benzophenones include benzophenone, 4-chlorobenzophenone, 4,4'-dichlorobenzophenone, and 3,3'-
Dimethyl-4-methoxybenzophenone, dibenzosuberenone and the like. Thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, 2-ethylanthraquinone, and acylphosphine oxides include diethoxyphosphine oxide.

The photoinitiator is usually 0.05 to 2 parts per 100 parts by weight of the acrylic resin having the (meth) acryloyl group and the low molecular weight compound.
0 parts by weight, preferably in the range of 0.5 to 10 parts by weight. Further, the photoinitiator is not limited to one kind, and two or more kinds may be used in combination.

A peroxide can be added to the photocurable sheet used in the present invention, if necessary (for example, when a molded article having a complicated shape is covered with the sheet, a portion not exposed to light is formed).

As the peroxide, a usual organic peroxide can be used.
More preferably, from the viewpoint of storage stability at room temperature, an organic peroxide having a decomposition temperature of 100 ° C. or higher is used. This includes, for example, 2,2-bis (ter-butylperoxy) butane, ter
-Butylperoxybenzoate, di-ter-butylperoxyisophthalate, methyl ethyl ketone peroxide, dicumyl peroxide, ter-butylperoxyacetate. The amount of the peroxide to be added is preferably in the range of 0.5 to 5.0 parts by weight based on 100 parts by weight of the low molecular weight compound having a (meth) acryloyl group. The peroxide is not limited to one type, and two or more types may be used in combination. The parts that are hard to cure by light irradiation due to the addition of these peroxides,
The sheet can be cured by heating the sheet during vacuum and / or pressure forming with a mold or by heat during injection molding.

To the photocurable resin composition used in the present invention, if necessary, materials such as a coloring agent such as a pigment and a dye and an antioxidant are added.

Pigments and dyes used in paints can be used as the coloring agent. Examples of the pigment include titanium oxide, iron oxide, carbon black, cyanine pigment, and quinacridone pigment.
Dyes include azo dyes, anthraquinone dyes, indigoid dyes, and stilbenzene dyes. Also,
Aluminum flakes, metal powders such as nickel powder, gold powder, and silver powder may be used as the coloring agent. These materials are preferably fine particles as much as possible. The amount of these additives depends on the solid content of the resin when a colorant having high opacity is used.
The range of 2 to 400 parts by weight is preferable for 100 parts by weight.
When these materials are added, it is preferable that the photoinitiator performs an initiation reaction with light having a wavelength with little absorption of the colorant.

In order to impart various functions to the photocurable sheet of the present invention, various functional additives may be added. Examples of the above-mentioned various function-imparting agents include a conductive material, an anti-condensation agent, a photochromic compound, and a rust inhibitor. When these materials are added, it is preferable that the photoinitiator performs an initiation reaction with light having a wavelength at which the functionality-imparting agent has little absorption.

[Form of photocurable sheet]

The above materials are kneaded to obtain a photocurable resin composition. When a base layer is formed from the photocurable resin composition, and the photocurable sheet is a single layer, this base layer becomes a photocurable sheet as it is. The sheet used in the present invention may be composed of a single layer consisting of only a base layer, or may be composed of a plurality of layers. When the sheet is composed of a plurality of layers, for example, there are the following forms.

A sheet comprising a transparent base layer (surface layer) and a coloring layer containing a coloring agent.

The colored layer can be formed from the photocurable resin composition used for the base layer. In this case, the colored layer may not contain elastic beads.

A sheet having a base layer or sheet and a back layer laminated on the back of the sheet.

This back surface layer is provided to improve the adhesion between the base layer and the injection resin, to withstand the shear stress of the injection resin, or to further improve the handleability of the sheet.

In order to increase the adhesion between the base layer and the resin, the back layer and the injection resin are preferably made of the same material or having excellent compatibility. When the adhesion between the base layer and the back layer is poor, a primer layer may be provided between both layers, and a plurality of back layers may be provided.

Since the sheet is stretched and attached to an adherend as necessary, it is preferable that these back layers (and the primer layer) are formed of a film which has ductility at least under heating.

As the resin used for the back layer, for example, polystyrene, acrylic polymer, polycarbonate, polyvinyl chloride, polyethylene, polypropylene, ABS
(Acrylonitrile-butadiene-styrene copolymer), modified polyphenylene oxide, polyphenylene sulfide, polyether imide, polyether ether ketone, polyethylene sulfide and the like.

A sheet having a base layer or the sheet obtained in the above, and an adhesive layer laminated on one surface of the sheet (in the case of the sheet, the outer surface of the back layer).

As the adhesive used for the adhesive layer, a pressure-sensitive adhesive, a hot-melt adhesive, and a post-curing adhesive are preferably used. Mixtures of these adhesives may be used.
A plurality of different types of adhesives may be sequentially laminated.

The pressure-sensitive adhesive, for example, rubber, acrylic,
There are urethane-based and silicone-based adhesives. Examples of the hot melt adhesive include an ethylene-vinyl acetate copolymer (EVA) and a styrene-isoprene-styrene block copolymer (SIS). Examples of the post-curing adhesive include a microcapsule curing adhesive. Examples of the material include an uncrosslinked unsaturated polyester adhesive, an uncrosslinked acrylic adhesive, and the like.

A sheet comprising the sheet obtained in the above-mentioned and a protective layer laminated on one side of the sheet.

The protective layer is laminated in order to provide shape retention during storage and use of the sheet and surface protection after application.

Since the sheet of the present invention is stretched and attached to an adherend as required, it is preferable that the protective layer is formed of a film (for example, a thermoplastic resin film or a rubber film) which has ductility at least under heating.

As the thermoplastic resin, for example, polyvinyl chloride, polyurethane, acrylic resin, polyester,
Examples include an ethylene-vinyl acetate copolymer, polyethylene, and polypropylene. Examples of the rubber film include natural rubber, styrene butadiene rubber, nitrile-butadiene rubber, isoprene rubber, butadiene rubber, chloroprene rubber, urethane rubber, silicone rubber, acrylic rubber, and the like. These thermoplastic resins and rubber mixtures can also be used. Alternatively, both films may be laminated.

The protective layer may be peeled off from the coating before light curing of the sheet, or may be used as a protective layer before using an injection molded article. If the surface of the protective layer is embossed or patterned, the surface shape (appearance) of the sheet can be changed.

A sheet in which printing is performed on the front surface or the back surface of the base layer of the photocurable sheet obtained in the above.

When printing is performed on the back surface of the base layer, the printed surface can be protected by the base layer.

The thickness of the photocurable sheet obtained above is 20 to 1,000 μm when affixed to an adherend surface having irregularities.
Degree is preferable, and when pasting on a flat surface, 10 to 500 μm
It does not matter. The thickness of the other layers laminated on the sheet is usually 10 to 500 μm, and the thickness of the adhesive layer is particularly preferably 10 to 100 μm.

(Preparation of photocurable sheet)

The photocurable sheet of the present invention may be prepared by any method. When the sheet has a single layer, the following casting method is preferred.

The photocurable resin composition is sufficiently dissolved or dispersed in an organic solvent. The resulting solution is coated on process paper (usually polyethylene terephthalate film or paper whose surface has been treated with silicone) using an apparatus such as a knife coater, comma coater or reverse coater, and then dried to remove the solvent. To form a base layer. A sheet is obtained by peeling the process paper from the base layer.

When the sheet is formed of a plurality of layers, it can be obtained by a casting method or a laminating method. According to the casting method, a solution containing the resin composition of one of the layers is coated on process paper, dried for solvent removal to form a base layer, and then the composition of another base layer is formed on the base layer. Coating the solution containing the
Drying for removing the solvent is performed to form another base layer. According to the laminating method, a solution containing the resin composition of each base layer is separately coated on process paper, dried and evaporated to form each layer, and then both layers are laminated ( (Heating) Compression bonding by roll press.

The process paper used in the production can be used as a protective sheet.

[Manufacturing Method of Injection Molded Article] Injection molding is usually carried out by heating the sheet at room temperature or by heating, making it adhere to the inside of the mold by vacuum and / or pressure molding, closing the mold and then injecting resin. This is performed by the sheet insert injection molding that is being performed. Next, light is applied to the obtained coated body (a sheet in which the solidified product of the injection resin is coated outside) (and may be heated if necessary), and the sheet is cured to obtain a molded product. As for the resin to be injected, any material can be used as long as the material is subjected to injection molding. For example, polystyrene, acrylic polymer, polycarbonate, polyvinyl chloride, polyethylene, polypropylene, ABS (acrylonitrile-butadiene-styrene copolymer), modified polyphenylene oxide, polyphenylene sulfide, polyetherimide, polyetheretherketone, polyethylene sulfide, liquid crystal There are polymers, glass fiber reinforced polyester, glass fiber reinforced epoxy, glass fiber reinforced acrylic resin, and the like.

(Action) The uncured or semi-cured photocurable sheet is excellent in extensibility, flexibility, elongation, etc., so that the sheet can be adhered well along the inner surface of the mold even in deep drawing. can do. Further, since this sheet is formed of a photocurable resin composition containing elastic beads, a film having a soft touch feeling (suede tone) can be formed by light irradiation.

(Examples) Hereinafter, the present invention will be described in detail based on examples. In addition, "part" means "part by weight".

(A) Preparation of curable sheet Example 10 Reactive acrylic resin (copolymer of methyl methacrylate, butyl acrylate and 2-hydroxyethyl acrylate, Mw = 86,000, Tg = 35 ° C., OH value = 5 100 parts acrylate monomer (manufactured by Nippon Kayaku Co., Ltd., KAYARAD
R604) 80 parts Photoinitiator (Nippon Kayaku Co., Ltd., Kaya Cure DETX) 1 part Photopolymerization accelerator (Nippon Kayaku Co., Ltd., Kaya Cure EP
A) 2 parts Elastic beads (Nippon Shokubai Chemical Co., Ltd., EBS100) 50 parts Isocyanate cross-linking agent (Nippon Polyurethane Industry Co., Ltd., Coronate L, NCO = 13.0%, solid content 75%)
2.2 parts by solid (this crosslinking agent has an isocyanate group equivalent to the functional group of the reactive acrylic resin) 300 parts or more of ethyl acetate were mixed with stirring.

This mixture was applied to an ABS sheet and dried at 80 ° C. for 5 minutes to obtain an uncured coating sheet. The thickness (thickness other than the ABS sheet) of the obtained coating sheet was 100 μm.

Example 11 Reactive acrylic resin (copolymer of methyl methacrylate, butyl acrylate and 2-aminoethyl acrylate, Mw = 143,000, Tg = 25 ° C., NH ₂ valence = 10) 100 parts Acrylate monomer (Japan KAYARAD, manufactured by Kayaku Co., Ltd.
MANDA) 20 parts Acrylate monomer (manufactured by Nippon Kayaku Co., Ltd., KAYARAD
DPCA20) 80 parts Photoinitiator (Irgacure, manufactured by Ciba-Geigy Japan)
184) 2 parts N-methyldiethanolamine 2 parts Elastic beads (Nippon Shokubai Chemical Co., Ltd., EBS100) 200 parts Epoxy crosslinking agent (Ciba-Geigy, Araldide CY)
175, epoxy equivalent 160, epoxy value 220 corresponding to the functional group value 3.6 parts (80% of the functional group of the reactive acrylic resin)
The reaction was mixed while stirring at least 300 parts of ethyl acetate.

This mixture was applied to an ABS sheet and dried at 80 ° C. for 5 minutes to obtain an uncured coating sheet. The thickness (thickness other than the ABS sheet) of the obtained coating sheet was 100 μm.

Example 12 Reactive acrylic resin (copolymer of methyl methacrylate, butyl acrylate and acrylic acid, Mw = 243,000, T
g = 0 ° C, COOH value = 10) 100 parts Acrylate monomer (manufactured by Nippon Kayaku Co., Ltd., KAYARAD
R604) 40 parts Photoinitiator (2,4,6-trimethylbenzoyl diphenylphosphine oxide) 4 parts N-methyldiethanolamine 2 parts Rutile-type titanium oxide 100 parts Elastic beads (Nippon Shokubai Chemical Industry Co., Ltd., EBS300) 100 parts Isocyanate-based crosslinking agent (Nippon Polyurethane Industry Co., Ltd., Coronate L, NCO = 13.0%, solid content 75%)
5.2 parts by solids (this crosslinking agent has 1.2 equivalents of isocyanate groups based on the functional groups of the reactive acrylic resin) 300 parts or more of ethyl acetate were mixed with stirring.

This mixture was applied to an ABS sheet and dried at 80 ° C. for 5 minutes to obtain an uncured coating sheet. The thickness (thickness other than the ABS sheet) of the obtained coating sheet was 80 μm.

Example 13 Reactive acrylic resin (copolymer of methyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate and 3-aminopropyl acrylate, Mw = 278,00
0, Tg = 65 ° C, OH value = 5, NH ₂ value = 10) 100 parts Acrylate monomer (manufactured by Nippon Kayaku Co., Ltd., KAYARAD)
R551) 50 parts Photoinitiator (2,4,6-trimethylbenzoyl diphenylphosphine oxide) 4 parts N-methyldiethanolamine 2 parts Iron oxide 50 parts Elastic beads (Nippon Shokubai Chemical Co., Ltd., EBS300) 150 parts Isocyanate Crosslinking agent (Nippon Polyurethane Industry Co., Ltd., Coronate L, NCO = 13.0%, solid content 75%)
6.5 parts in solids (this crosslinker has 1.0 equivalent of isocyanate group to the functional group of the reactive acrylic resin) 300 parts or more of ethyl acetate were mixed with stirring.

The mixture was applied to the release surface of a PET film, dried at 80 ° C. for 5 minutes, and then the PET film was peeled off to obtain an uncured coating sheet. The thickness of the obtained coating sheet was 50 μm.

Example 14 Reactive acrylic resin (copolymer of methyl methacrylate, butyl acrylate and 2-hydroxyethyl acrylate, Mw = 153,000, Tg = 45 ° C., OH value = 10) 100 parts Acrylate monomer (Nippon Kagaku) KAYARAD, manufactured by Yakuhin Co., Ltd.
DPCA-20) 50 parts Photoinitiator (2,4,6-trimethylbenzoyl diphenylphosphine oxide) 2 parts N-methyldiethanolamine 2 parts Elastic beads (Nippon Shokubai Chemical Co., Ltd., EBS300) 200 parts Isocyanate-based crosslinking agent (Nippon Polyurethane Industry Co., Ltd., Coronate L, NCO = 13.0%, solid content 75%)
5.2 parts by solids (this crosslinking agent has 1.2 equivalents of isocyanate groups based on the functional groups of the reactive acrylic resin) 300 parts or more of ethyl acetate were mixed with stirring.

This mixture was applied to the release surface of a PET film and dried at 80 ° C. for 5 minutes. The thickness of the obtained coating sheet (PET
Other sheet thickness) was 50 μm. (Clear layer) Reactive acrylic resin (copolymer of methyl methacrylate, butyl acrylate and 2-hydroxyethyl acrylate, Mw = 653,000, Tg = 45 ° C, OH value = 10) 100 parts Acrylate monomer (new NP manufactured by Nakamura Chemical Industry Co., Ltd.
A-10G) 80 parts Photoinitiator (2,4,6-trimethylbenzoyl diphenylphosphine oxide) 4 parts N-methyldiethanolamine 2 parts Rutile-type titanium oxide 100 parts Isocyanate-based crosslinking agent (Nippon Polyurethane Industry Co., Ltd., Coronate L, NCO = 13.0%, solid content 75%)
5.2 parts by solids (this cross-linking agent has 1.2 equivalents of isocyanate groups based on the functional group of the reactive acrylic resin) Ethyl acetate 300 parts This mixture is applied on the clear layer, and the mixture is applied at 80 ° C. for 5 minutes. After drying, peel off the PET film,
An uncured coating sheet was obtained. The thickness of the obtained coating sheet was 50 μm for the clear layer and 50 μm for the colored layer.

Example 15 Reactive acrylic resin (copolymer of methyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate and 3-aminopropyl acrylate, Mw = 78,000,
Tg = 30 ° C, OH value = 15, NH ₂ value = 10) 100 parts Acrylate monomer (manufactured by Nippon Kayaku Co., Ltd., KAYARAD)
DPCA-20) 50 parts Photoinitiator (2,4,6-trimethylbenzoyl diphenylphosphine oxide) 4 parts N-methyldiethanolamine 2 parts Elastic beads (Nippon Shokubai Chemical Co., Ltd., EBS300) 200 parts Isocyanate-based crosslinking agent (Nippon Polyurethane Industry Co., Ltd., Coronate L, NCO = 13.0%, solid content 75%)
10.8 parts in solid content (this crosslinking agent has an isocyanate group equivalent to the functional group of the reactive acrylic resin) Ethyl acetate 300 parts or more were mixed with stirring.

This mixture is treated with an ABS sheet (A20
5, film thickness 500 μm) and dried at 80 ° C. for 5 minutes. The thickness of the obtained covering sheet (thickness of sheets other than the ABS sheet) was 100 μm.

Example 16 Reactive acrylic resin (copolymer of methyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate and 3-aminopropyl acrylate, Mw = 78,000,
Tg = 30 ° C, OH value = 15, NH ₂ value = 10) 100 parts Acrylate monomer (manufactured by Nippon Kayaku Co., Ltd., KAYARAD)
R604) 1000 parts Photoinitiator (2,4,6-trimethylbenzoyl diphenylphosphine oxide) 4 parts N-methyldiethanolamine 2 parts Rutile-type titanium oxide 100 parts Isocyanate-based crosslinking agent (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) NCO = 13.0%, solid content 75%)
10.8 parts in solid content (this crosslinking agent has an isocyanate group equivalent to the functional group of the reactive acrylic resin) Ethyl acetate 300 parts or more were mixed with stirring.

This mixture is treated with an ABS sheet (A20
5, film thickness 500 μm) and dried at 80 ° C. for 5 minutes. The thickness of the obtained covering sheet (thickness of sheets other than the ABS sheet) was 50 μm (colored layer).

Reactive acrylic resin (copolymer of methyl methacrylate and butyl acrylate, 2-hydroxyethyl acrylate and 3-aminopropyl acrylate, Mw = 78,000,
Tg = 30 ° C, OH value = 15, NH ₂ value = 10) 100 parts Acrylate monomer (manufactured by Nippon Kayaku Co., Ltd., KAYARAD)
DPCA-20) 50 parts Photoinitiator (2,4,6-trimethylbenzoyl diphenylphosphine oxide) 2 parts N-methyldiethanolamine 2 parts Elastic beads (Nippon Shokubai Chemical Co., Ltd., EBS300) 200 parts Isocyanate-based crosslinking agent (Nippon Polyurethane Industry Co., Ltd., Coronate L, NCO = 13.0%, solid content 75%)
10.8 parts in solid content (this crosslinking agent has an isocyanate group equivalent to the functional group of the reactive acrylic resin) Ethyl acetate 300 parts or more were mixed with stirring.

This mixture was applied on the colored layer and dried at 80 ° C. for 5 minutes. The thickness of the obtained covering sheet (thickness of sheets other than the ABS sheet) is 50 μm for the colored layer + 40 μm for the clear.
Layer.

Example 17 Reactive acrylic resin (copolymer of methyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate, acrylic acid and 3-aminopropyl acrylate,
Mw = 353,000, Tg = 45 ° C., OH value = 5, COOH value = 5, NH ₂ value = 10) 100 parts Acrylate monomer (manufactured by Nippon Kayaku Co., Ltd., KAYARAD)
R604) 40 parts Photoinitiator (2,4,6-trimethylbenzoyl diphenylphosphine oxide) 4 parts N-methyldiethanolamine 2 parts Peroxide (manufactured by NOF Corporation, Perhexa 3M) 1 part Rutile-type titanium oxide 100 parts Elastic beads (Nippon Shokubai Chemical Co., Ltd., EBS300) 150 parts Melamine cross-linking agent (Dainippon Ink Chemical Co., Ltd., Super Bacamine J-820-60) solid content of 9.2 parts (of the above reactive acrylic resin) Isocyanate-based cross-linking agent (Coronate L, NCO = 13.0%, solid content 75%, manufactured by Nippon Polyurethane Industry Co., Ltd.)
Solids 5.2 parts (this crosslinking agent has 0.6 equivalents of isocyanate groups based on the functional groups of the reactive acrylic resin) 300 parts or more of ethyl acetate were mixed with stirring.

This mixture is applied to the release surface of the ABS sheet, and
After drying for a minute, an uncured coating sheet was obtained. The thickness of the obtained covering sheet is 200 (the thickness other than the ABS sheet)
μm.

Example 18 Reactive acrylic resin (a reactive acrylic resin obtained by adding 2-hydroxyethyl acrylate to a copolymer of methyl methacrylate, butyl acrylate, and acrylic acid,
Weight average molecular weight = 175,000, Tg = 20, average double bond per molecule = 18, COOH value = 5) 100 parts Acrylate monomer (manufactured by Shin-Nakamura Chemical Co., Ltd., NP
A-10G) 50 parts Photoinitiator (2,4,6-trimethylbenzoyl diphenylphosphine oxide) 4 parts N-methyldiethanolamine 2 parts Elastic beads (Nippon Shokubai Chemical Co., Ltd., EBS100) 200 parts Isocyanate cross-linking agent (Nippon Polyurethane Industry Co., Ltd., Coronate L, NCO = 13.0%, solid content 75%)
2.2 parts by solid (this crosslinking agent has an isocyanate group equivalent to the functional group of the reactive acrylic resin) 300 parts or more of ethyl acetate were mixed with stirring.

This mixture was applied on an ABS sheet and dried at 80 ° C. for 5 minutes to obtain an uncured coating sheet. The thickness of the obtained covering sheet (the thickness other than the ABS sheet) was 150 μm.

Example 19 Reactive acrylic resin (a reactive acrylic resin obtained by adding 2-hydroxyethyl methacrylate to a copolymer of methyl methacrylate, butyl acrylate and acrylic acid, weight average molecular weight = 258,300, Tg = 0) , Average double bond per molecule = 40, COOH value = 10) 100 parts Acrylate monomer (manufactured by Shin-Nakamura Chemical Co., Ltd., NP
A-10G) 50 parts Photoinitiator (2,4,6-trimethylbenzoyl diphenylphosphine oxide) 4 parts N-methyldiethanolamine 2 parts Rutile-type titanium oxide 50 parts Elastic beads (EBS300, manufactured by Nippon Shokubai Chemical Industry Co., Ltd.) 200 parts Isocyanate-based crosslinking agent (Nippon Polyurethane Industry Co., Ltd., Coronate L, NCO = 13.0%, solid content 75%)
5.2 parts by solids (this crosslinking agent has 1.2 equivalents of isocyanate groups based on the functional groups of the reactive acrylic resin) 300 parts or more of ethyl acetate were mixed with stirring.

This mixture was applied on an ABS sheet, dried at 80 ° C. for 5 minutes, and an ethylene-methyl acrylate film (PE2255 manufactured by Chevron Chemical Co., Ltd., thickness: 20 μm) was laminated (protective layer) to obtain an uncured coating sheet. Was. The thickness of the obtained covering sheet (thickness other than the ABS sheet) was 50 μm for the colored layer + 20 μm for the protective layer.

(B) Injection molding Injection molding was performed as follows using the injection molding machine shown in FIG. This injection molding machine is provided with a moving mold 10 having a concave-convex portion 10a for molding and a hole for drawing a vacuum, a fixed mold 12 having a convex portion 12a, and disposed between the two molds 10, 12. It has a hot platen 14 having holes for vacuum and compressed air, and a resin injection machine 15, which can move outward from between the two dies 10, 12.

First, as shown in FIG. 1 (b), a sheet 13 is disposed between the moving mold 10 and the hot platen 14, and the sheet 13 is heated.
The sheet 13 was subjected to vacuum and / or pressure forming, and was brought into close contact with the inner surface of the concave portion 10a of the mold 10. Next, as shown in FIG. 1 (c), the hot platen 14 is taken out from between the two dies 10, 12, and then the movable dies 10 are moved toward the fixed dies 12 to close the dies. . Next, ABS resin (ABS-ME, manufactured by Denki Kagaku Kogyo Co., Ltd.) was injected from the resin injection machine 15 into the cavity formed by the molds 10 and 12. As the injection molding conditions, the temperature at the tip of the nozzle of the resin injection machine was 230 ° C. After molding, the coated body was taken out of the mold and the curable sheet on the surface of the coated body was cured with a metal halide lamp under the conditions shown in the following table to obtain an injection-molded product. The Taber abrasion test (Taber 1 kg, CS17, 1000 rotations) on the surface of the injection-molded product after curing, the adhesion by the grid test (the number of grids remaining after the tape was peeled off), and the soft touch feeling (feeling) were evaluated. The test results are shown in Tables 1 and 2. In the above Examples 10 to 19, the uncured coated sheet (photocurable sheet) is formed by crosslinking the acrylic resin appropriately with a crosslinking agent.
The flexibility, extensibility and elongation of the sheet are improved,
Even when the deep drawing was performed, the sheet was satisfactorily molded and adhered to the shape of the mold without being broken, and the sheet was not broken when the resin was injection-molded.

(Comparative example) ABS resin sheet (manufactured by Sanbo Plastics Co., Ltd., A205, 500μ)
m), a soft touch paint (Cenosoft II, manufactured by Cashew Co., Ltd.) was applied to a thickness of 50 μm and cured by heating at 80 ° C. for 30 minutes. Using the obtained sheet, injection molding was performed in the same manner as in the example. 160 ° C and 180 sheets in female mold
When the ABS resin was injected after vacuum and pressure forming at a temperature of ° C, the sheet could not be formed into a female shape due to insufficient elongation of the sheet, and the sheet was cracked at the same time as the resin was injected.

(Effects of the Invention) The present invention covers the photocurable sheet by injection molding a molding resin in a state where the photocurable sheet in an uncured or semi-cured state is adhered to the inner surface of a mold, and thereafter, is irradiated with light. It forms a cured film of the photocurable sheet.
For this reason, the coating which was conventionally performed in the post-process can be omitted, and there is no environmental problem such as removal of a coating space or a solvent, and further, it is possible to manufacture a molded product without any trouble even in deep drawing. Further, since the photocurable sheet is formed of a photocurable resin composition containing elastic beads, it is possible to produce a molded article having a soft touch feeling (suede tone). Therefore, there is an advantage that decoration of housings, stationery and the like of OA equipment and home appliances can be performed easily and at low cost.

[Brief description of the drawings]

1 (a) to 1 (d) are explanatory views showing a method for producing an injection-molded article of the present invention. 10 ... movable mold, 12 ... fixed mold, 13 ... photo-curable sheet, 14
... hot platen, 15 ... resin injection machine.

Claims (1)

(57) [Claims] (E) a molecule having a plurality of functional groups such as a hydroxyl group, an amino group and a carboxyl group in the molecule, and having a weight average molecular weight of
(H) a plurality of (meth) acryloyl groups and functional groups such as a hydroxyl group, an amino group and a carboxyl group in the acrylic resin or (h) molecule which are solid at room temperature and have a weight average molecular weight of 50,000 to 1,000,000 An acrylic resin which is solid at room temperature, (b) a low molecular weight compound having a (meth) acryloyl group in a molecule, (c) a photoinitiator, (d) an elastic bead, and (f) an isocyanate-based resin. Uncured or semi-cured light formed of a photocurable resin composition containing, as a main component, at least one crosslinking agent selected from the group consisting of a crosslinking agent, a melamine-based crosslinking agent, and an epoxy-based crosslinking agent. A step of attaching the curable sheet to the inner surface of the mold by vacuum and / or pressure molding, a step of injection molding a molding resin in the mold to form a coated body covered with the photocurable sheet, and the coating Light to body Irradiating the photocurable sheet to cure the photocurable sheet.