SU456855A1 - Method of plating the surface of plastic products - Google Patents

Description

(54) METHOD OF METALIZATION OF THE SURFACE OF PLASTIC PRODUCTS

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The invention relates to the field of plastics processing with the aim of improving their physicochemical properties, communicating the surface of electrical and thermal conductivity products, soldering ability, and certain optical properties and can be used in enterprises of the chemical and electronic industry.

There is a known method of metallization of llasmaos, according to which before applying a layer of metal in one way or another, the surface of the plastic is subjected to special treatments that provide a durable and non-peeling metal coating.

Thus, for example, by chemical metallization, the surface of the product is subjected to varnishing, matting, degreasing, sensitization, washing.

In galvanic metallization, surface preparation is reduced to degreasing, pickling, sensitizing and washing.

When shooopirovaniya (spraying molten metal in a jet of compressed air) clean the surface from fatty substances and moisture and give it roughness.

The preparatory operations are laborious, time consuming and in a number of cases the adhesion of the conductive layer to the surface (plastics is not high enough).

In order to improve the quality of the coating, simplify and speed up the process according to the invention, the plastic product is treated with an aerosol stream containing solvent vapors and fine metal powder prior to the application of the metal coating.

The preparation of the surface of plastic products is carried out as follows.

Products are cracked into a chamber, into which an aerosol stream containing solvent vapors (mixed with air) and fine metal powder is supplied. The product chamber is placed in such a way that it is well blown from all sides by an aerosol stream.

Depending on the type of processed

Plastics use a variety of solutions. For example, for polyvinyl acetate plastics - acetone, ethyl alcohol, benzene, toluene, for polyvinylformal - cyclohexane, dioxane, dichloroethane, acetic

acid; for polyvinyl chloride, cyclohexane, tetrahydrofuran; for polymethyl methacrylate - dichloroethylene, methyl methacrylate, glacial acetic acid; for polystyrene, benzene, toluene, acetone; for polyethylene - toluene, xylene (s hot state) -. The concentration of the vapor-air mixture is chosen experimentally on the basis of the softening of the plastic product to a small depth (less than 0.1 mm), taking into account the minimum processing time. From the same calculation, the temperature of the clown mixture is established. The solvent, its concentration, temperature, and exposure time are chosen such that deformation of the workpiece does not occur.

To reduce the consumption of reagents, the process is conducted in a closed cycle, maintaining the selected parameters for the concentration and temperature of the vapor-air mixture, as well as the concentration of metal powder in the aerosol stream and its velocity.

As fine powders with a particle size of less than 40 microns, you can use, for example, iron (obtained by the carbonyl method) copper, aluminum, bronze, silver, nickel, chromium, nickel alloys, bismuth and manganese alloys, steel (various grades), zinc, etc. .

Depending on the type of plastic, the bulk, the product and the selected solvent, its concentration in the vapor-air mixture should be varied from 10 to 100% (it is advisable to use a high concentration of solvent and vapor-air mixture for bulk products).

The concentration of the fine metal powder in the aerosol stream is 0.5-10 g / m, and at a concentration below 0.5 g / m, the process of metal deposition on the surface of the product extends over time, and at a concentration above 10 g / m, uneven toll, ine coating and high metal consumption.

The speed of the aerosol stream should not exceed 1 m / s, at high speeds due to (the resulting turbulence creates unequal conditions for blowing various surfaces of the product.

Example. An α-polystyrene plate is thick; another 2MM is processed (in a closed loop) with a 40% air-vapor mixture of benzene. The quality of the metal used is powdered copper with an average particle size.

10 microns. The concentration of fine copper powder in an aerosol stream of 2 g / m.

The speed of the aerosol stream is 0.4 m / s, and the temperature is 20 ° C

The processing time of a thin-walled product in

These conditions are about 40 minutes.

Subject invention

The method of metallization of the surface of plastic products based on thermoplastics, including the preparation of the surface of the plastic body by treating it with an aerosol stream and the actual metallization, characterized in that, in order to improve the quality of the coating, simplify and speed up the process, the plastic product is treated with an aerosol stream containing solvent and fine metal powder at a flow rate of 0.2-1 m / s and containing metal in it 0.5-10 g / m.