JPH08108448A - Production of plastic molding - Google Patents

Abstract

PURPOSE: To obtain a molding having good appearance by simultaneously subjecting a color sheet wherein a base sheet layer, a color sheet layer and a clear layer are successively laminated and a plastic material to molding processing in such a state that the base sheet surface of the color sheet comes into contact with the outer surface of a plastic molding. CONSTITUTION: A color sheet is formed by successively laminating a base sheet layer, a color sheet layer and, if necessary, a clear layer. The color sheet and a plastic material are simultaneously subjected to molding processing to fuse and bond the base sheet layer of the color sheet and the plastic material. A colorant is added to the base sheet layer. The heated molten plastic material is filled into the gap between the color sheet and the base sheet layer and cooled to produce a polypropylene molding. By this constitution, the surface of the base sheet layer of the color sheet is brought into contact with the outer surface of the molded product simultaneously with molding processing. Therefore, the obtained molding has no wrinkles in its curved surface part and flat surface part and is improved in appearance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a novel plastic molded product.

[0002]

2. Description of the Related Art Conventionally, plastic molded products have been widely used as members for automobiles, home appliances and general industries. Further, for the purpose of decoration and improvement of durability, the plastic molded product is generally coated with, for example, a room temperature curable organic solvent-based paint using an isocyanate curable acrylic resin.

However, in this coating method, the product cost is high due to the poor coating efficiency with respect to the plastic molded product, the finish is poor because the curved surface cannot be uniformly coated, and an organic solvent or isocyanate is used. Therefore, there is a problem that the working environment becomes worse.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have formed a base sheet layer, a coloring layer and, if necessary, a clear layer in this order. It has been found that a method of simultaneously molding and processing a colored sheet and a plastic material solves all the above-mentioned problems, and has completed the present invention.

That is, according to the present invention, a colored sheet and a plastic material, in which a base sheet layer, a colored layer and, if necessary, a clear layer are sequentially laminated, are provided so that the base sheet layer surface of the colored sheet is in contact with the outer surface of the plastic molded product. In addition, the present invention relates to a method for producing a plastic molded article, which comprises simultaneously molding and processing a colored sheet and a plastic material.

The colored sheet used in the method of the present invention has a structure in which a base sheet layer, a colored layer and, if necessary, a clear layer are sequentially laminated.

Base sheet layer : The base sheet layer is for bonding the coloring sheet to the plastic surface. That is, the base sheet layer of the colored sheet and the plastic material are melted and joined by simultaneously molding and processing the colored sheet and the plastic material.

Specific examples of the base sheet layer include polyethylene, polypropylene, polyisobutylene, polybutadiene, polystyrene, polychloroprene, polyvinyl chloride, polyvinyl acetate, nylon, acrylic resin, polycarbonate, cellulose, polyethylene terephthalate, polyacetal, and the like. AS resin, ABS
A thermoplastic resin such as a resin may be used.

The base sheet layer may contain known additives such as colorants, fillers, plasticizers and heat stabilizers, if necessary. The thickness of the base sheet layer is usually about 20 to 1,000 μm, preferably about 100 to 300 μm.
A range of m is desirable. When the film thickness is less than about 20 μm, the finished appearance of the plastic molded product deteriorates. On the other hand, when the film thickness exceeds about 1,000 μm, the handling becomes difficult and the workability deteriorates. It is not preferable because the finished appearance is deteriorated.

Colored layer : The colored layer is used for providing decoration, display, etc. to the molded product. Specific examples of the colored layer include those formed of a coloring resin composition obtained by mixing a colorant component with a resin component such as a thermoplastic resin and a curable resin. As the thermoplastic resin, for example,
Examples thereof include urethane resin, vinyl resin, silicone resin, fluororesin, polyester resin and the like.

As the curable resin, for example, room temperature or 1
Examples thereof include resins that are cured by heating at about 40 ° C. or lower, resins that are cured by active energy rays, and the like. As the resin that cures at room temperature or by heating, for example, a polyol resin (vinyl resin, polyester resin, silicone resin, fluororesin, etc.) is used as a base resin, and a (block) polyisocyanate compound, an amino resin, as a crosslinking agent,
Peroxidation catalyst (perbutyl oxide, etc.) in resins containing alkoxysilane group-containing compounds, resins containing alkoxysilane groups, hydroxyl groups and epoxy groups, unsaturated resins (vinyl resins, polyester resins, silicone resins, etc.) And the like.

Examples of the resin curable by active energy rays include the above unsaturated resins and, if necessary, unsaturated monomers ((meth) acrylic acid ester, styrene, (poly) ethylene glycol di (meth) acrylic acid ester). Etc.) and the like.

As the colorant, a colored (dye) pigment, a fluorescent (dye) pigment or the like can be used. As the color pigment, for example, inorganic pigments such as carbon black and titanium oxide,
Organic pigments such as quinacridone type such as quinacridone red, azo type such as pigment red, phthalocyanine type such as phthalocyanine blue, phthalocyanine green, metallic like aluminum powder, copper powder, mica-like iron oxide powder, bronze powder, stainless steel powder, etc. Examples include scaly powder that can express a tone or pearly color.

The mixing ratio of the coloring or fluorescent pigment varies depending on the required performance, kind, etc., but the resin solid content is 1
Usually, a range of about 0.5 to 300 parts by weight, preferably about 3 to 150 parts by weight is desirable per 100 parts by weight.

In addition to the above, for example, an organic solvent, a plasticizer, a filler, a fluidity adjusting agent, a curing catalyst, an ultraviolet absorber and the like can be blended as the coloring resin composition. The thickness of the colored layer is usually about 10 to 100 μm,
A range of about 30 to 80 μm is desirable.

Clear layer : The clear layer is for protecting the colored layer, and can be provided if necessary. The clear layer can be formed by a clear resin composition obtained by adding no colorant to the above coloring resin composition or adding a colorant to the extent that the base can be seen. Among the clear resin compositions, it is preferable to use a curable resin as a resin component. The thickness of the clear layer is usually about 10-10.
The desired range is 0 μm, preferably about 30-80 μm.

The above-mentioned pressure-sensitive adhesive layer, colored layer and clear layer can be formed by, for example, spraying, roll-coating, knife-coating, curtain-flow coating, silk-screen, gravure printing or the like with the composition forming each layer. it can.

In the colored sheet used in the method of the present invention, a surface treatment (for example, corona discharge treatment, primer coating, etc.) can be performed between the base sheet layer and the colored layer, if necessary. The coloring sheet is, for example,
To form a colored layer by coating, printing and drying a coloring resin composition on the surface of the base sheet, and subsequently coating, printing and drying a clear resin composition as necessary to form a clear layer. Can be obtained by

The method of the present invention is a method of simultaneously molding the colored sheet and the plastic material such that the base sheet layer surface of the colored sheet contacts the outer surface of the plastic molded product.

In the method of the present invention, the pressure-sensitive adhesive sheet and the plastic material are molded at the same time, and the molding method is preferably injection molding. The injection molding method is performed by injecting and filling a heat-melted plastic material into a colored sheet provided in a mold, then cooling, and then taking out the plastic material from the mold as a molded product. The colored sheet provided in the mold is preferably installed so that the colored layer or the clear layer of the colored sheet is in contact with the inner surface of the mold and the base sheet layer is in contact with the surface of the plastic. The heat-melted plastic material is injected into the colored sheet provided in the mold, but at this time, the molten plastic material is not filled between the mold surface and the colored sheet surface, so that the colored sheet base sheet is used. Fill in the layer surface direction.

The size of the coloring sheet may be a part of the inner surface of the mold or the entire size.
That is, by changing the size of the coloring sheet, the coloring sheet can be formed on part or all of the surface of the plastic molded product.

As the plastic material, any conventionally known material can be used without particular limitation. Specifically, for example, polyethylene, polypropylene, polyisobutylene, polybutadiene, polystyrene, polychloroprene, polyvinyl chloride, polyvinyl acetate, nylon,
Acrylic resin, polycarbonate, cellulose, polyethylene terephthalate, polyacetal, AS resin, A
Examples thereof include BS resins and glass fiber reinforced resins obtained by mixing these with glass fibers.

If desired, known additives such as colorants, fillers, plasticizers and heat stabilizers can be added to the plastic material.

The molding processing temperature may be set to a temperature suitable for the types of the colored sheet and the plastic material, but the melting temperature of the plastic is usually about 180 to 250.
C., preferably about 180 to 230.degree. C., and a mold temperature of about 30 to 70.degree. C., preferably about 40 to 50.degree.

[0025]

EXAMPLES The present invention will be described in detail below with reference to examples.

Example 1 A polypropylene sheet (base sheet) having a film thickness of 150 μm was coated with Retan PG-80 metallic (trade name, isocyanate curing acrylic resin paint manufactured by Kansai Paint Co., Ltd.) so that a dry film thickness of 30 μm was obtained. Then, it is dried at 80 ° C. for 10 minutes, and then Retan PG-80 Quartz Clear (manufactured by Kansai Paint Co., Ltd., trade name, isocyanate-curable acrylic resin paint) is dried to a film thickness of 40 μm.
The coating was applied so that the thickness became m, and the coating was dried at 80 ° C. for 10 minutes to produce a metallic colored sheet.

The colored sheet obtained above is placed on the inner surface of an injection mold that can be processed into a bumper shape for automobiles so that the clear layer of the colored sheet is in contact with the inner surface of the mold.
Next, polypropylene that was heated and melted at about 230 ° C. was pressure-injected into the base sheet layer surface of the colored sheet by an injection molding machine, and then the mold was cooled and taken out from the mold to manufacture a polypropylene molded product.

The polypropylene molded product thus obtained had a good appearance with no defects such as wrinkles, blisters, bubbles, gloss reduction, peeling and cracks on both the curved surface portion and the flat surface portion. After immersing the polypropylene molded product in 40 ° C. water for 20 days, the presence of defects such as peeling of the part to which the pressure-sensitive adhesive sheet was adhered, blisters, deterioration of gloss, etc. was examined and found to be good without any abnormalities. It was

Example 2 A polypropylene sheet (base sheet) having a thickness of 150 μm was coated with Retan PG-80 White (Kansai Paint Co., Ltd.).
(Product name, isocyanate curing acrylic resin paint)
Was coated to a dry film thickness of 30 μm and dried at 80 ° C. for 10 minutes to produce a white colored sheet.

Next, molding processing was performed in the same manner as in Example 1 to manufacture a polypropylene molded product. The obtained polypropylene molded product has wrinkles on both the curved surface portion and the flat surface portion.
Good appearance with no defects such as blisters, bubbles, lower gloss, peeling, and cracks. After the polypropylene molded product was immersed in 40 ° C. water for 20 days, the presence of defects such as peeling off of the adhesive sheet, blistering, and deterioration of gloss was examined, and it was found that there were no abnormalities and all were good. It was

[0031]

Since the method of the present invention has the above-mentioned constitution, it can be evenly applied to an adherend having a curved surface, so that it has an excellent finished appearance and is easy to apply. It exhibits excellent effects such as good adhesion to materials.

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Claims (2)

[Claims] 1. A coloring sheet comprising a base sheet layer, a coloring layer, and a clear layer if necessary, and a plastic material, wherein the base sheet layer surface of the coloring sheet is in contact with the outer surface of the plastic molded product. And a method for producing a plastic molded article, which comprises simultaneously molding and processing a plastic material. 2. The method for producing a plastic molded product according to claim 1, wherein the molding process is an injection molding method.