JPH11123739A - Method for producing high gloss injection molded article and molded article thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a high-gloss injection molded article or a high-gloss injection compression molded article without impairing the molding cycle, regardless of the surface structure of the mold and without modifying the mold, and The molded article is provided. SOLUTION: A film made of a thermoplastic resin (B) that does not melt and adhere to the thermoplastic resin (A) to be subjected to injection molding or injection compression molding is inserted into the surface of a mold, and then the thermoplastic resin (A) is removed. A high gloss injection molded article or a high gloss injection compression molded article characterized in that the film is coated on the surface of the molded article by injection molding or injection compression molding, and the film is peeled from the surface of the obtained molded article. Manufacturing method and molded product thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a high gloss injection molded article or a high gloss injection compression molded article, and to the molded article.

[0002]

2. Description of the Related Art In injection molding or injection compression molding of a thermoplastic resin, as a means for improving the surface gloss of a molded article and improving the surface appearance, a mold temperature and an injection temperature are used. In addition, measures have been taken by increasing the injection pressure and increasing the adhesion to the mold wall surface. Among these measures, the most effective way to improve the surface quality of the molded product is to raise the mold temperature.However, this will not only increase the cooling time but increase the molding cycle, but also increase the molded product after release. Undesirably increases the deformation of.

In order to make up for this defect, a thin heat insulating layer is arranged on the surface of the mold, and the cooling from the mold wall surface during the filling of the resin is temporarily delayed to improve the gloss of the molded product so that the skin layer is not generated as much as possible. (Japanese Patent Application Laid-Open No. 2-153715).

Further, there has been proposed a mold which aims at the same effect by heating only at the time of filling the resin by using an electromagnetic induction heating structure which can be controlled at a temperature arranged on the mold cavity side (Japanese Patent Publication No. 7-59368). Gazette). These techniques all produce effects by modifying and modifying ordinary dies, and no effects are obtained with dies produced as ordinary injection molding dies.

[0005] On the other hand, there have been many methods for decorating the surface of a molded product by inserting a resin film printed on a mold or a multilayer film containing a resin layer containing an appropriate amount of a coloring agent containing a glittering material. Although proposals have been made, it is difficult to obtain a beautiful molded product in the pasted and synthesized form of these films because a printed pattern flows or a difference in shade of pigment appears at the corner of the molded product. Was. Further, as a means for preventing scratches on the surface of the molded article and making the appearance defect inconspicuous, a molded article having a grained surface on the molded article has also been proposed, but the surface of the molded article subjected to such graining has been proposed. It was not possible to improve the gloss.

An object of the present invention is to provide a method for producing a high gloss injection molded article or a high gloss injection compression molded article without impairing the molding cycle, irrespective of the surface structure of the mold, and without modifying the mold. It is to provide the molded article.

The inventors of the present invention have conducted intensive studies, and as a result,
A thermoplastic resin to be used for injection molding is inserted into a mold and a film made of a thermoplastic resin that cannot be bonded is bonded and molded, and after release, the film is peeled off from the surface of the obtained molded article. The inventors have found that the object of the present invention is achieved, and have completed the present invention.

[0008]

That is, the present invention relates to a thermoplastic resin (A) used for injection molding or injection compression molding.
A film made of a thermoplastic resin (B) that does not melt and adhere to the surface of a mold, and then the thermoplastic resin (A) is subjected to injection molding or injection compression molding to coat the film on the surface of the molded article. And a method for producing a high gloss injection molded product or a high gloss injection compression molded product, wherein the film is peeled from the surface of the obtained molded product. The present invention also relates to an injection-molded product or an injection-compression-molded product made of a thermoplastic resin (A), wherein a film made of a thermoplastic resin (B) that does not melt and adhere to the thermoplastic resin (A) is molded. A high-gloss injection molded article or a high-gloss injection compression molded article characterized by being a molded article obtained by coating the product surface and peeling it off. Hereinafter, the present invention will be described in detail.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The production method of the present invention comprises inserting a film made of a thermoplastic resin (B) which does not melt and adhere to a thermoplastic resin (A) to be subjected to injection molding or injection compression molding into a mold. Then, the thermoplastic resin (A) is subjected to injection molding or injection compression molding to coat the film on the surface of the molded product, and the film is peeled off from the surface of the obtained molded product. The production method of the present invention
The die may be a die subjected to graining. The film does not need to be inserted on both surfaces of the molded product,
What is necessary is just to insert on the design side.

An injection molding method or an injection compression molding method (hereinafter, referred to as an injection molding method)
Both molding methods are referred to as “injection molding method”), and are not particularly limited, and a known injection molding method is used.

The thermoplastic resin (A) used in the present invention is not particularly limited as long as it can be used in a usual injection molding method. Examples of the thermoplastic resin (A) include a polyethylene resin, a polypropylene resin, a polystyrene resin, polyvinyl chloride,
Examples include at least one thermoplastic resin selected from polyamide, polycarbonate, polyphenylene ether, polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymer, a mixture thereof, and a modified product thereof. Among them, at least one selected from polyethylene-based resins, polypropylene-based resins, polystyrene-based resins, polyphenylene ether, polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymers, mixtures thereof and modified products thereof Is preferred. Further, at least one thermoplastic resin selected from a polyethylene resin, a polypropylene resin, a mixture thereof, and a modified product thereof is more preferable. In particular, propylene homopolymer,
Propylene-ethylene random copolymer, propylene-
Most preferred is a polypropylene resin such as an ethylene block copolymer or a resin composition containing the polypropylene resin as a main component. In the thermoplastic resin, fillers such as talc, mica, and barium sulfate, ethylene-α
-An olefin copolymer rubber or a styrene elastomer may be contained. If necessary, various commonly used additives such as a nucleating agent, an antioxidant, an ultraviolet absorber, a flame retardant, and a coloring agent may be contained in appropriate amounts.

It is more preferable to add a glittering material to these thermoplastic resins in an amount of 0.01 to 5% by weight, preferably 0.05 to 2% by weight, since a metallic appearance can be obtained. Examples of the glittering material include mica powder whose surface is coated with aluminum powder or titanium oxide.

The film of the thermoplastic resin (B) used in the present invention may be any film that does not melt and adhere to the thermoplastic resin (A). When the thermoplastic resin (A) for injection molding is a polypropylene resin, examples of the thermoplastic resin (B) include a polyester resin, a polystyrene resin, and an acrylic resin. The thermoplastic resin (B) may contain an appropriate amount of various commonly used additives such as a nucleating agent, an antioxidant, an ultraviolet absorber, a flame retardant, and a coloring agent, if necessary.

The film may be a single layer or a multilayer. In the case of a multilayer film, the surface in contact with the molded product may be a layer made of the thermoplastic resin (B).

Further, the thickness of the film is preferably 50 to 200 μm, more preferably 80 to 120 μm.
It is. If the thickness is less than 50 μm, the effect of improving gloss may be reduced. When the thickness exceeds 200 μm, the effect of the present invention is not particularly lost, but when a film is inserted into the mold, there is a possibility of damaging the mold surface in the case of a mirror mold, and in the case of a grain mold, The grain transferability may be poor. The thickness of the film is measured with a micrometer.

The molded article of the present invention is obtained by laminating the above-mentioned film and molding, so that when a mold having a mirror-finished design surface is used, the glossiness of the lamination surface becomes less than that of the non-lamination surface. Improved compared to. Further, when a mold whose design surface is textured is used, the effect is further enhanced. That is, the molded article of the present invention may have a grain on the surface of the molded article.

[0017]

As described in detail above, according to the present invention,
A method for producing an injection-molded article or an injection compression-molded article in which the surface gloss in injection molding is improved without impairing the molding cycle and without modifying the conventional mold, regardless of the surface structure of the mold, and the molding thereof. Goods can be provided. In addition, according to the present invention, a molded product having remarkably excellent surface gloss can be obtained even if the molded product is molded using a mold subjected to grain processing. Further, the high gloss injection molded article or the injection compression molded article of the present invention is suitable for automobiles, household electric appliances, containers and the like.

[0018]

Hereinafter, the present invention will be described based on examples.
The present invention is not limited to these examples.

Injection molding machines used in Examples and Comparative Examples,
The mold, the shape of the molded product and the evaluation method are as follows. (1) Injection molding machine and mold FS160S25ASEN made by Nissei Resin Molding temperature: 221 ° C Mold (a) 150 mm × 300 mm × 3 mmt flat plate mold, side (fan) gate (18 mm × 1 mm) Mold (b) 150 mm × 300 mm × 3mmt mold with grain, 4 points tunnel gate (gate diameter 1mm), grain shape: Tanako Hachimitsu TH-621 Mold temperature: fixed side 38 ° C, moving side (film insert side) 35 ° C (2) Glossiness JIS Based on the method specified in -K-7105, the 45 ° specular gloss of the film release surface of the molded product was measured. (3) Feeling of depth The surface of the injection-molded article from which the film was peeled was subjected to a visual sensory evaluation as described below. 5: The same degree of depth as a painted product obtained by applying a metallic coating on the surface of a normal injection molded article and then applying a clear coating. 4: Sufficient depth was obtained though slightly inferior to 5 above. 3: A feeling of depth is recognized. 2: Although the feeling of depth is inferior to that of the above 3, it does not mean that there is no feeling of depth at all. 1: There is no sense of depth at all.

Example 1 As a thermoplastic resin composition for injection molding, the following PP was used.
T-1 was used. 61 parts by weight of a crystalline propylene-ethylene block copolymer (MFR: 58 g / 10 min, content of a random copolymer portion of ethylene units and propylene units: 12% by weight), 61 parts by weight of ethylene-butene-1 copolymer rubber ( Butene-1 unit content: 18% by weight) 14 parts by weight,
14 parts by weight of ethylene-propylene copolymer rubber (content of propylene unit: 27% by weight) and talc (D ₅₀ :
2.1 μm) A composite polypropylene as a resin composition consisting of 11 parts by weight was used. The composite polypropylene and each component thereof were produced based on the methods described in Example 1 and Reference Examples 1 to 4 of JP-A-5-86256. A base material colored by adding 0.2 parts by weight of carbon black to 100 parts by weight of this composite polypropylene was coated with aluminum powder (manufactured by Toyo Aluminum Co., Ltd .;
The resin composition obtained by adding 0.7 parts by weight of an aspect ratio 7) was designated as PPT-1. The film to be inserted has a thickness of 100 μm processed by a known method.
PET-made film (F-1) was used. After inserting the film (F-1) into the mold (a) surface, PPT
-1 after injection molding, the film (F-
1) was peeled off to obtain a molded product. Table 1 shows the results.

Example 2 A molded product was obtained in the same manner as in Example 1 except that the mold (b) was used as the mold. Table 1 shows the results.

COMPARATIVE EXAMPLE 1 The injection molding thermoplastic resin PPT-1 was used in Example 1 without performing the insert molding of the film as in Example 1.
A molded product was obtained in the same manner as described above. Table 1 shows the results.

Comparative Example 2 The injection molding thermoplastic resin PPT-1 was used in Example 2 without performing the insert molding of the film as in Example 2.
A molded product was obtained in the same manner as described above. Table 1 shows the results.

[0024]

[Table 1] --------- −−−−−−−−−−−−−−−−−−− Thermoplastic resin for injection molding PPT-1 PPT-1 PPT-1 PPT-1 Mold abab Film thickness (μm) 100 100 − − Gloss (%) 75 54 30 1.6 A sense of depth (5 levels) 4 3 1 1 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 503: 06 507: 04 B29L 9:00

Claims (10)

[Claims] 1. A thermoplastic resin (B) which does not melt and adhere to a thermoplastic resin (A) to be subjected to injection molding or injection compression molding.
Is inserted into the surface of a mold, and then the thermoplastic resin (A) is subjected to injection molding or injection compression molding to coat the film on the surface of the molded product. A method for producing a high-gloss injection molded article or a high-gloss injection compression-molded article, characterized in that: 2. The method according to claim 1, wherein the thickness of the film made of the thermoplastic resin (B) is 50 to 200 μm. 3. The thermoplastic resin (A) contains a glitter material in an amount of from 0.01 to 0.01%.
The method for producing a molded article according to claim 1, which contains 5% by weight. 4. The thermoplastic resin (A) is a polypropylene resin, the thermoplastic resin (B) is a polyester resin,
2. A polystyrene resin or an acrylic resin.
A method for producing the molded article according to the above. 5. The method for producing a molded product according to claim 1, wherein the die is a die subjected to graining. 6. An injection molded article or an injection compression molded article comprising a thermoplastic resin (A), wherein said thermoplastic resin (A)
A high gloss injection molded article or a high gloss injection compression molded article obtained by coating a surface of the molded article with a film made of a thermoplastic resin (B) that does not melt and bond, and then peeling the molded article. Goods. 7. The molded article according to claim 6, wherein the thickness of the film made of the thermoplastic resin (B) is 50 to 200 μm. 8. The thermoplastic resin (A) may contain a glitter material in an amount of from 0.01 to 0.01.
The molded article according to claim 6, which contains 5% by weight. 9. The thermoplastic resin (A) is a polypropylene resin, the thermoplastic resin (B) is a polyester resin,
7. A polystyrene resin or an acrylic resin.
The molded article as described. 10. The molded article according to claim 6, wherein the molded article has a grain on its surface.