JP3225567B2 - Double side plating method for FRP molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for plating both sides of an FRP molded product.

[0002]

2. Description of the Related Art The plating of a thermoplastic ABS resin molded product is as follows.
Usually, as shown in FIG. 4, the etching is performed after a chemical etching step is performed in a pretreatment step of plating. However, among thermoplastic resins, polycarbonate, polymer alloy (modified PPE / PA) and the like are difficult to be plated, so that a resin material is blended with a rubber-based material which is easily etched in advance, and molded. In the process, as shown in FIG. 5, a special etching process is added in the middle of the pre-processing process. However, the resin molding material that is difficult to be plated has a special etching treatment agent depending on the resin component, so that the process is complicated and a mass production line is currently provided with another line.

[0003] In recent years, a sheet molding compound (hereinafter referred to as S), which is a typical molded product of FRP (glass fiber reinforced resin) which has come into practical use as an outer panel of an automobile.
MC) is obtained by compression molding, the matrix resin is an unsaturated polyester resin,
In addition to the difficulty in plating, fine holes called pinholes are formed on the surface of the SMC molded product. Even if plating is performed on this surface, the appearance will be poor.
Plating on the surface of the MC molded product has been difficult to put to practical use.

As one of measures against pinholes generated on the surface of an SMC molded product, an in-mold coating method (hereinafter referred to as I) is used.
MC). This IMC is a method of coating simultaneously with molding of plastic. The present applicant has previously filed a patent application for the invention of the plastic inmold coating method (Japanese Patent Application No. 1-181778, Japanese Patent Application Laid-Open No. 3-47-47).
719).

[0005] On the other hand, plating on FRP, which is difficult to plate, is performed in the same way as the method shown in FIG. In this case, there is a method in which a paint which is easily etched in the plating pretreatment step is spray-painted in advance, and then plating is performed in a normal plating step shown in FIG.

[0006] The present applicant uses IMC paint mixed with a material which is easily etched in a normal plating process to form a molded article having a coating film formed on the surface side of a product,
Next, a patent application (Japanese Patent Application No. Hei 3-126666) was filed for an invention in which the molded product is plated by a normal plating process.
No.)

[0007]

According to the above-mentioned method of pre-treating using a chemical for etching the FRP surface and then plating, a plating pre-treatment step facility of another line is installed in the same manner as the step shown in FIG. And increase capital investment. Also, the usual plating process for ABS resin molded products
It is difficult to obtain a paint with good adhesion to both the SMC material and the plating material by a method of spraying a paint which is easy to be etched by the chemical etching process in the previous step, and then plating it in the usual plating process of the ABS resin molded product. Since the adhesion of the film and the plating layer is not sufficiently satisfied, and the thickness of the coating film of the spray coating is 20 to 30 μm, as shown in FIG.
The surface of the coating film d sprayed on the surface of the RPa has an orange skin, which remains on the plated layer e after plating, so that a smooth plated surface cannot be obtained and is clearly inferior to the plated surface of the conventional steel plate. Will do.

In the plating method using the IMC of the invention of the prior application, only the front side of the molded product can be treated, and the surface of the FRP material without the IMC coating film remains on the back surface of the molded product. When this molded product is flowed to the normal ABS resin plating process, it is plated on the front surface side with the IMC coating film, but the back surface is not FRP material and is not plated or has very poor adhesion. It becomes a plating surface. Therefore, the back surface is also unsuitable for products that require good appearance. In addition, the FRP exposed on the back surface in the plating step dissolves in a processing solution, particularly an etching solution in the chemical plating step, and lowers its processing ability, thereby causing a reduction in productivity and plating failure. As a solution to this problem, the back side of the molded product is coated with a fluorine-based resin in advance, and then flown to the plating process to prevent the dissolution of FRP. However, since no plating is attached to the back surface of the product, the following There's a problem. Since the coefficient of thermal expansion of the plating layer c attached to the front surface of the plated product 10 shown in FIG. 6A is different from that of the FRP layer a on the back surface, in the case of a product having a large thin plate shape, the contraction force of the plating layer c on the front surface indicates As shown in FIG. 6B, warpage occurs in the product, resulting in a product defect.

[0009] The present invention solves the above-mentioned problems, and allows plating of an FRP molded product by a normal ABS resin plating process. A smooth plating layer adheres to the surface of the product with sufficient strength, and plating is also performed on the back surface of the product. It is an object of the present invention to provide a method of plating both sides of an FRP molded product in which a layer is formed to improve the appearance of the product and the plated product is not likely to be deformed by heat.

[0010]

The FRP molded article of the present invention is
In the plating process, chemical etching is performed in the pretreatment process
A is, the present invention uses a mold to mold the FRP molded product, and then in leaving the mold closed mold, plating Engineering
Molding the extent of pre-treatment step by chemical etching by coating contaminating paint the easy material to the surface and implanted into the surface side of the FRP molded product at a high pressure is formed FRP molded article, and then the removal from the mold The plating process is performed on the back of the FRP molded product .
This is a double-sided plating method for an FRP molded product in which a paint to be etched by a chemical etching process is applied, and then the FRP molded product having a coating film formed on both front and back surfaces is plated by the above-described plating step.

[0011]

[Function] As an IMC paint on the surface of FRP molded product,
As paint such as spraying on the surface, on both sides of the FRP molded product ,
Both because coating is etched <br/> ring in the chemical etching process of the plating process is formed, the molded FRP
The product is used in the chemical etching process of the pretreatment process of the plating process.
It is easily etched, and the
The tack layer is firmly bonded to the front and back coating surfaces, and the surface of the plated product is smooth, and deformation due to heat is suppressed.

[0012]

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a partial sectional view of a double-sided plated product according to the present invention, FIG.
FIG. 2 is a cross-sectional view of an IMC mold for an automobile panel. The molded article 1 is formed with a tab 1a serving as an inlet for paint on the front side. In the mold for molding the molded article 1, a cavity having a shape corresponding to the molded article is formed between the upper mold 2 and the lower mold 3 of the split mold, and the upper mold 2 for molding the surface side of the molded article 1 has: Tab 1a
And a nipple 5 for connecting an exhaust passage 6 provided on the opposite side to a vacuum pump, and a lower die 3 for molding the back side of the molded article 1 is provided with a pressure sensor 7. Is installed. Reference numeral 8 denotes a seal, and 9 denotes a temperature control circuit provided in each of the upper and lower molds.

Next, an IMC using the mold shown in FIG. 2 will be described. Place the SMC material on the lower mold 3 and close the upper mold 2, 7
Hold at a molding pressure of 0 to 80 kg / cm ² for a specified time and
Cure the MC material. After the SMC material is cured, the molding pressure is once reduced to about 20 kg / cm ² , and the air in the mold is discharged from the exhaust passage 7 for 2 to 3 seconds. Next, tab 1a
From the inlet 4 of the upper die in the position, the chemical et pretreatment step
300 kg / ml of IMC paint that was easily etched in the normal plating process of the ABS resin molded product to be etched
cm ^{2 at} a high pressure, and after the paint was injected, the molding pressure was increased to 40 cm.
It is raised to about Kg / cm ² and held for several seconds to flow the paint on the surface of the molded article. Thereafter, the molding pressure is again increased to 0 to 20.
Kg / cm ² and hold in this state for a specified time to cure the paint.

As described above, if the inside of the mold is evacuated with the mold closed before the paint is injected, air cannot be trapped in the mold when the paint is injected. The paint is preferable because it flows well on the surface of the cured SMC due to an increase in molding pressure, and a good coating film can be stably obtained. However, depending on the shape of the molded product, exhaust is not necessarily required. As the IMC coating material, a base resin blended with a component which is easily etched such as a urethane acrylate oligomer and a filler such as calcium carbonate is used.

As shown in FIG. 1, the molded product taken out of the mold has a thickness of 70 mm on the surface of the FRP layer a molded by SMC.
The IMC coating film b having a thickness of about 100 .mu.m is firmly adhered, and pinholes and the like generated on the surface of the FRP are filled with the IMC coating material b and the surface is smooth. A coating of the following components is applied to the back surface of the molded article by spraying or brushing, and the coating is cured at room temperature or by heating to 80 ° C. Resin component Paint of phenolic resin, alkyd resin, amino alkyd resin, acrylic resin, unsaturated resin, epoxy resin, polyurethane resin, or a blended paint thereof. Pigment Colorants such as extender pigments such as calcium carbonate, barium sulfate, talc, clay, white carbon, and carbon, and inorganic pigments such as titanium dioxide, zinc white, and red bean, and organic pigments. Auxiliary materials Materials and solvents for accelerating drying of coatings, improving pigment dispersibility, adjusting paint fluidity, and adjusting coating surface.

The molded product having the cured coating film on the back surface is treated by the usual ABS resin plating process shown in FIG. This FRP
The IMC coating b of the surface of, since it is easily etched by chemical etching step of a conventional plating process of ABS resin molded article, together with the plating layer c is firmly adhered to the IMC coating b, plating layer c Has a smooth surface, and has a good appearance equal to or better than the plated surface of a conventional steel plate. The coating film d on the back surface is also processed in the chemical etching step, and the back surface plating layer e is formed. Although the surface of the plating layer e on the back surface is not as smooth as the surface plating layer c, the coating film d
And the deformation of the plated product due to heat can be prevented. In addition, there is no need to newly provide a special plating process, and chemical etching is
The processing can be performed without any trouble in a normal plating process of the ABS resin to be applied .

The headlamp reflector of an automobile shown in FIG. 7 is a reflector 20 injection molded using a bulk molding compound (hereinafter referred to as BMC) at present.
It is manufactured by applying aluminum vacuum evaporation to the light reflecting surface of. BMC is a molding material obtained by mixing or impregnating an unsaturated polyester resin blended with a hardening agent and a condensing agent into a chopped strand of glass fiber, and then gelling this.
Heat resistance is higher than other molding materials (200 ° C).
Since the curvature of the light reflecting surface 21 can be freely changed, it is suitable for forming a reflector. In a molded product obtained by injection-molding a reflector using a BMC, sink marks are generated on the light reflecting surface opposite to the reinforcing ribs 22 formed on the back surface of the reflector, and pin holes are generated on the surface. Although the amount of sink marks during molding of BMC is smaller than that of other synthetic resin molding materials, it causes a problem as a reflecting surface of a reflector. The present invention can be applied not only to a molded product made of SMC but also to a molded product made of BMC such as a reflector. The plating layer on the reflecting surface of the reflector is smoothed by the IMC coating film and the projections such as the reinforcing ribs 22 are formed. Since a coating film can be easily formed on a certain back surface, a double-sided plating layer can be easily formed even on a molded product having a complicated back shape.

[0018]

According to the present invention, a coating film is formed on both sides of an FRP molded product by a conventional IMC mold and ordinary coating means such as spraying, and the FRP molded product is chemically etched in a pretreatment step.
Since the double-sided plating is performed by the plating process of applying a double-sided plating, a double-sided plated product can be obtained at low cost without requiring a new capital investment. In addition, deformation of the FRP plated product due to heat can be suppressed.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a double-sided plated product of the present invention.

FIG. 2 is a cross-sectional view of an IMC mold used in the present invention.

FIG. 3 is a partial cross-sectional view of a plated product according to a conventional method.

FIG. 4 is a view showing a conventional ordinary plating process of an ABS resin molded product .

FIG. 5 is a view showing a conventional special plating process.

FIG. 6 is a sectional view of a single-side plated product.

FIG. 7 is a sectional view of a reflector.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Molded product 1a Paint injection tab 2 Upper die
3 Lower mold 4 Paint inlet 7 Pressure sensor 20 Reflector

Continued on the front page (72) Inventor, Ryofusa Narazaki, 8 Dosa, Fujisawa-shi, Kanagawa Prefecture, Isuzu Central Research Laboratory Co., Ltd. (72) Inventor, Naotaka 8 Mototsuka, Fujisawa-shi, Kanagawa Prefecture, 8 Isuzu Central Research Institute, Inc. 72) Inventor Takashi Fujita 8 Dosana, Fujisawa-shi, Kanagawa Prefecture, Isuzu Central Research Laboratory Co., Ltd. (72) Inventor Ryomitsu Suyama 8 Tosanabe, Fujisawa-shi, Kanagawa Prefecture, Isuzu Central Research Institute Co., Ltd. (72) Inventor, Ohori Tokuko 8 Tsurana, Fujisawa, Kanagawa Prefecture Isuzu Central Research Laboratory Co., Ltd. (56) References JP-A-4-228592 (JP, A) JP-A-61-273921 (JP, A) JP-A-58-125762 ( JP, A) JP-A-62-260093 (JP, A) JP-A-63-270495 (JP, A) JP-A-5-156051 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , (DB name) B29C 43/14-43/20 B29C 43/32-43/34 C08J 7/04

Claims (1)

(57) [Claims] 1. An FRP molded product is molded using a mold,
Then in the left mold closed mold, of the pretreatment step
Molding the FRP molded article coating film formed on the surface by implanting the surface side of the FRP moldings Manabu etching is mixed with material easily chemically etched in a plating process to be applied paint at a high pressure, and then from the mold A paint to be etched by chemical etching in the plating step was applied to the back surface of the removed FRP molded product, and a coating film was formed on both front and back surfaces.
FRP molded products are subjected to chemical etching in the pre-treatment process.
Characterized in that plating is performed by a plating process
Plating method for double-sided RP products.