JPS593957B2 - Plating method for plaster products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for metal plating onto porous products, typically gypsum.

Conventionally, cast products such as copper and copper alloys have often been used for metal decorative items, reproductions of arts and crafts, lighting stands, miscellaneous goods, etc., but casting methods result in products that are significantly more expensive. However, there are drawbacks such as poor practicality, and the casting surface of cast products is not very good.

As an alternative to metal castings, there are plastic plated products.

This is inexpensive, lightweight, and has a cheap feel. In addition, for small rod production, amortization of mold costs becomes a problem.
Although it is possible to increase the weight of plastic using fillers, etc., it has the disadvantage of being expensive. Therefore, it may be possible to use a plaster product that can be easily molded, is inexpensive, and has a sense of weight, and then plated with metal on top of this, but since plaster is water-absorbing, it is difficult to plate directly on top of it. I can't.

Therefore, it is considered that plating may be performed after impregnating the material with paraffin. However, in plaster products, 15% dissolved in solvents
In the case of products impregnated with paraffin, the solvent that permeates inside is difficult to evaporate and remains, so when the product is immersed in a heated plating solution, the solvent will blow out from the inside, making plating difficult. Alternatively, gypsum products may be immersed in heated and melted paraffin (melting point: 45-65°C), but gypsum is unstable above 60°C, and the temperature of the paraffin bath cannot be raised too much, causing the paraffin to fill the recesses. It becomes difficult to produce fine patterns. Furthermore, even if the coating is possible, if the bath temperature is raised too high during plating, the paraffin will
5. It melts and makes the plating incomplete. The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to develop a method that can eliminate the water absorption of plaster products, etc., and apply good metal plating to the surface thereof, and to improve the appearance and weight of the products. Our objective is to provide a product that is fully comparable to the 30-metal gold castings and is also inexpensive. In order to achieve this object, the present invention proposes the following methods: (1) adding a water-soluble water-repellent waterproofing agent to calcined gypsum powder, etc., molding the powder, and then applying plating; or (2) molding plaster After impregnating a molded product with a water-repellent waterproofing agent, plating is applied.

Before plating, the gloss of the plating surface can be reduced by applying a mixture of water-soluble synthetic resin and water, or colloidal silica to the surface of plaster products impregnated with a water-repellent waterproofing agent. Improve even further. This method can also be applied to porous materials other than gypsum, such as bisque, cement, etc.

The above-mentioned water-repellent waterproofing agents include POlOnC, KC88
(The above are oil-based).

In addition, as a treatment material to form a coating film on the surface of a molded product such as plaster that has been treated with a waterproofing agent, to improve the finish of the surface of the molded product such as plaster, and to increase the gloss of the plating surface applied to the surface, Water-soluble synthetic resins, such as LHlOO (acrylic, I-mulsion) manufactured by Mitsubishi Rayon Co., Ltd., POlOnMF-40 (silicon-acrylic copolymer emulsion) manufactured by Shin-Etsu Chemical Co., Ltd., or colloidal silica, such as Chitsuso Chemical Co., Ltd. Silk Ral MS
A solution prepared by adding -30 and diluting it with water is used. In the following examples, as the calcined gypsum, Sakura stamped gypsum grade A manufactured by Yoshino Gypsum Co., Ltd. or calcined gypsum for ceramics manufactured by Nitto Gypsum Co., Ltd. was used as appropriate.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Calcined gypsum 6009 was added to 420 cc of water, mixed well, and then poured into a mold.

After about 35 minutes, remove the molded product from the mold and heat it at about 50℃ for 8~
It was dried with hot air for 15 hours. This molded product is 3% POlOnC.
Immerse in the solution for about 3 minutes. Air bubbles are generated from the molded product,
POlOnC is impregnated and bubbles stop forming after approximately 3 minutes. Leave this at room temperature for a day, or heat it to 50℃ for 8 days.
After drying for ~15 hours, the surface was plated.
A good plated product with no defects was obtained. Example 2 Plaster of Paris 6001 is added to 420 CC of 3% POlOnC solution, mixed well, and then poured into a mold.

After about 60 minutes, it was removed from the mold, dried with hot air at about 50°C for 8 to 15 hours, and then plated.
A good plated product was obtained. Example 3 The dried plaster moldings of Examples 1 and 2 before plating were immersed in a mixed solution of 1 part POIOnMF-40 and 9 parts water, or the mixture was applied to the surface and dried at 50°C for 8 hours. After that, plating was applied, and a plated product with better gloss than the previous example was obtained.

Example 4 The dried plaster moldings of Examples 1 and 2 before being plated were immersed in a mixed solution consisting of part LHlOOl, 1 part Silkral MS-30, and 1 part water, or the surface was coated with 50% After drying at ℃ for 8 hours, plating was applied, and a plated product with even more gloss than the product of Example 3 was obtained.

In the above examples, water-based PO was used as the water-repellent waterproofing agent.
Although an example using lOnC has been described, similar results were obtained using the other water-based water-repellent waterproofing agents mentioned above.

Furthermore, although the oil-based water-repellent waterproofing agent can only be applied to molded products made from gypsum, similar results can be obtained through the same steps as in Example 1. The plating method used in the above examples was a well-known plastic plating method.

That is, an electrically conductive paint is applied to the surface of the plaster molded product before plating, or the surface of the molded product is activated with an aqueous solution of stannous chloride, etc., and then chemical plating is applied using a silver mirror reaction, etc., to make the surface electrically conductive. After that, electroplating was carried out in the usual manner. Types of metsuki include copper, copper-all-metal,
Plating was carried out using copper-silver, copper-nickel chrome, etc., and the effect was comparable to that of metal castings in both appearance and weight, and it could be fully used in the field of arts and crafts.

Claims (1)

[Scope of Claims] 1. A method for plating a gypsum product, which comprises impregnating a gypsum molded product with a water-repellent waterproofing agent, and then applying plating on the impregnated molded product. 2. A plaster product characterized by impregnating a plaster molded product with a water-repellent waterproofing agent, forming a coating film of a water-soluble synthetic resin on the impregnated molding, and then plating the coating film. Plating method.