JP2001225371A - Coated/printed article of reinforced plastic molding and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain coated/printed article excellent in adhesion of coating/ printing ink which is a molding produced from a reinforced plastic raw material in which a thermoplastic resin is incorporated with fibers or a filler. SOLUTION: The reinforced plastic raw material is molded by a heat-cycle molding method in which the surface temperature of a mold cavity is repeatedly increased/decreased to obtain the molding in which the exposure of the fibers or the filler is prevented. Next, the molding is subjected to coating/printing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated / printed reinforced plastic molded product and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a conventional injection molding method is carried out using a reinforced plastic raw material in which fibers such as glass fibers and carbon fibers and at least one kind of plate-like filler such as talc or granular filler such as charcoal are blended. To obtain a molded product.

[0003]

A molded article obtained from a reinforced plastic raw material in which fibers such as glass fiber and carbon fiber and at least one kind of a particulate filler such as talc or plate-like or charcoal is mixed, It is excellent as an industrial material because it has much higher rigidity and strength than molded products obtained from neat resin containing no fibers or fillers.

[0004] Molded articles obtained from the above-mentioned reinforced plastic raw materials have a rough surface due to the fact that fibers and fillers are exposed on the surface of the molded article and the flow unevenness of the fibers and fillers is clearly visible and the appearance is not good. Is rarely used for However, for thin-walled housings and the like, rigidity and strength are desired, and there is a strong demand to use reinforcing materials such as fibers and fillers. As long as it can be painted or printed on this molded product, it will meet your wishes.However, paint and printing ink are poorly adherent to fibers because their properties are set so that they adhere to the resin. There was a problem of peeling. In addition, those with filler
There have been problems that the surface of the molded product is rough and the finish of the painted surface is poor, or so-called paint is sucked in and the surface is poor.

An object of the present invention is to obtain a coated / printed product having excellent adhesion performance of paint and printing ink by using a molded product made of a reinforced plastic raw material in which fibers and fillers are mixed with a thermoplastic resin.

[0006]

The coated and printed reinforced plastic molded product of the present invention is obtained by heating a reinforced plastic raw material in which fibers and fillers are blended with a thermoplastic resin by repeatedly raising and lowering the temperature of the mold cavity surface. It is molded by a cycle molding method, and the molded product is coated and printed.

Further, the method for producing a coated / printed product of a reinforced plastic molded product according to the present invention is characterized in that a reinforced plastic raw material in which fibers and fillers are blended with a thermoplastic resin is subjected to a heat cycle in which the temperature of the cavity surface of a mold is repeatedly increased and decreased It is molded by a molding method, and the molded product is coated and printed to obtain a coated and printed product.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A synthetic resin molding die used in a method for producing a coated / printed product of a reinforced plastic molded product according to the present invention will be described.

FIG. 1 is a schematic sectional view of an injection mold. In the mold of this embodiment, a nest 2 is provided in a mold base 1 of the mold, and a cavity 3 is formed in the nest 2.

In the vicinity of the cavity surface 4, a series of flow passages A for alternately and repeatedly flowing a heating medium and a cooling medium are provided. The hydraulic equivalent diameter d of the channel A is 3 to 6 mm, and the distance h from the cavity surface 4 to the surface of the channel A is 1 to 10 mm. Saturated steam, superheated steam, pressurized water, hot water, and the like are used as a heating medium, and cooling water is used as a cooling medium.

In the mold of this embodiment, since the flow path A is provided in the insert 2, the processing of the flow path A becomes easier as compared with the case of processing into an integrated die, and there is no stagnation of the medium and the surface of the cavity is formed. It is possible to form the channel A in which the temperature is uniform.

A heat insulating layer 5 made of air is provided between the insert 2 and the matrix 1. The heat insulating layer 5 may be made of a material having a low thermal conductivity other than air. The heat insulating layer 5 insulates the nest 2 from the matrix 1 and reduces the heat load, so that the cavity surface 4 of the nest 2 can be rapidly heated and cooled. Further, the matrix 1 is provided with a flow path B through which a cooling medium always flows. The role of the flow path B is to control the temperature of the mother die 1, so that the temperature change of the cavity surface 4 does not spread to the entire die, and when the die is closed, the movable die and the fixed die are closed. The risk of galling due to the difference in expansion is eliminated. In the above embodiment, the heat insulating layer 5 is provided, but may not be provided depending on the mold. In the mold of this embodiment, a nest 2 is provided in each of the molds 1 of the movable mold and the fixed mold, and a flow path A is formed in each of the nests 2. The flow path A may be formed only in

FIG. 2 is a schematic cross-sectional view of the injection mold having the nest shown in FIG. In the mold of the second embodiment, the flow path A provided near the cavity surface 4 of the nest 2 and through which the heating medium and the cooling medium alternately and repeatedly flow, and the cooling medium provided at a position farther from the cavity surface 4 , Which is a two-way flow path structure of a flow path C that always flows. In addition, a flow channel B through which a cooling medium always flows into the matrix 1 is provided, and a heat insulating layer 5 is provided between the nest 2 and the matrix 1. The flow path C may not be filled with a cooling medium or may be kept under reduced pressure.

In each of the molds of the above two embodiments, the nest is provided in the mold base, but the mold may not be provided.

The mold used in the present invention is not limited to the above-described mold, but a mold which can switch between heating and cooling of the surface of the mold in a short time, that is, a heat cycle molding method. Any mold can be used as long as it can be heated and cooled. Note that the heat cycle molding method is a molding method in which the temperature of the cavity surface of the mold is increased when filling the molten resin into the mold, and the temperature of the cavity surface is decreased after the filling is completed. As the heat cycle molding method, many methods such as a method of passing a heating and cooling medium near the cavity surface and a method of using an electric heater or high frequency to heat the cavity surface have been proposed.

[0016] Painting of the reinforced plastic molding of the present invention
The method for manufacturing a printed product uses the above-described mold, and when filling the cavity of the mold with a reinforced plastic raw material in which fibers and fillers are blended with a thermoplastic resin, the temperature of the cavity surface is kept high, After the filling is completed, the molded product is taken out by lowering the temperature of the cavity surface, and the molded product is coated or printed to produce a coated / printed product of a reinforced plastic molded product.

As described above, when the cavity surface of the mold is heated at the time of filling, the flowability of the reinforced plastic raw material is improved and thin-wall molding can be performed. Further, fibers and fillers contained in the molten resin are not exposed on the surface. Therefore, since the surface of the molded article is a thermoplastic resin, the paint and the printing ink adhere to the surface of the molded article, and the paint and the printing ink are not sucked.

Next, the method for producing a coated / printed product of a reinforced plastic molded product according to the present invention will be described in more detail.

The temperature of the cavity surface of the mold is increased by a heat cycle molding method, and at least one of a fiber and a plate-like or granular filler: 10 to 10% by weight of the thermoplastic resin is contained in the cavity. By injecting a reinforced plastic raw material containing up to 50% by weight by an injection molding method, a molded product in which fibers and fillers are not exposed on the surface is obtained. Next, the temperature of the cavity surface is lowered and the molded product is taken out, and the surface of the molded product is coated or printed to obtain a coated / printed product.

As the thermoplastic resin, general-purpose resins, general-purpose engineering plastics, super engineering plastics and the like are used.

As the fibers, glass fibers, carbon fibers, alumina fibers, metal fibers, and the like are used.

As the filler, a plate-like filler such as talc and a granular filler such as charcoal are used.

The injection molding includes, besides ordinary injection molding, injection compression, local vibration / pressing, gas pressing,
Gas assist method, hollow molding method, sandwich molding method, 2
Color molding method, in-mold molding method, push-pull molding method,
A high-speed injection molding method or the like is used.

The above-mentioned coating includes brush coating, spray coating,
Electrostatic coating is used, and lacquer type,
An enamel type, an ultraviolet ray / electron beam curing type, etc. are used.

For the printing, screen printing, gravure printing, flexographic printing and the like are used.

When the adhesion test of the coated / printed product manufactured by the above-mentioned manufacturing method was performed, the same result as that of the coated / printed product of the molded product formed of neat resin containing no fiber or filler was obtained. In the adhesion test, the sample after coating and printing was allowed to stand for 5 days, immersed in water at 25 ° C. for 24 hours, air-dried at 25 ° C., and subjected to a peeling test using cellophane tape.

[0027]

The molded product obtained by the heat cycle molding method which raises and lowers the temperature of the cavity surface of the mold does not expose fibers or fillers on the surface, so that the paint or printing ink is peeled off by painting or printing. It is possible to obtain a painted / printed product having no surface finish and good finish.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an injection molding die used in a method for producing a coated / printed product of a reinforced plastic molded product of the present invention.

FIG. 2 is a schematic cross-sectional view of an injection mold having two channels in a nest.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Master mold 2 Nesting 3 Cavity 4 Cavity surface 5 Heat insulation layer A, B, C Channel

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masahiko Yamaki 2-1-1 Tango-dori, Minami-ku, Nagoya City, Aichi Prefecture Inside Mitsui Chemicals, Inc. (72) Inventor Akihiko Imagawa 2-1-1 Tango-dori, Minami-ku, Nagoya City, Aichi Prefecture Mitsui Chemicals, Inc. F term (reference) 4F202 AB16 AD16 CA11 CB01 CK41 CN01 CN05 CN12 CN27 4F206 AB16 AD16 JA07 JN43 JQ81

Claims (4)

[Claims] 1. A reinforced plastic raw material in which fibers and fillers are blended with a thermoplastic resin is molded by a heat cycle molding method in which the temperature of a cavity surface of a mold is repeatedly increased and decreased, and the molded product is coated and printed. Painted and printed products made of reinforced plastic moldings. 2. The reinforced plastic raw material is characterized in that 50 to 90% by weight of a thermoplastic resin and 10 to 50% by weight of a fiber and at least one of a plate-like or granular filler are blended. A coated / printed product of the reinforced plastic molded product according to claim 1. 3. A reinforced plastic raw material in which fibers and fillers are blended with a thermoplastic resin is molded by a heat cycle molding method in which the temperature of a cavity surface of a mold is repeatedly increased and decreased, and the molded product is coated and printed. A method for producing a coated / printed product of a reinforced plastic molded product, characterized by the following. 4. The reinforced plastic raw material is a thermoplastic resin in which at least one kind of fiber and plate-like or granular filler is blended.
A method for producing a coated / printed product of the reinforced plastic molded product described in the above.