US2447380A - Process for metalizing nonmetallic articles - Google Patents

Description

Patented Aug. 17, 1948 PROCESS FOR METALIZING N ONMETALLIC ARTICLES Frederick Ross Wenger, Los Angeles, Calif., assignor to Focal Company, Downey, Califl, a corporation of California No Drawing. Application May 4, 1944, Serial No. 534,170

2 Claims. 1

This invention relates to an improved process for plating non-metallic substances or articles such as plastics, paper, Celluloid, bone, hard rubber, wood, leather, cloth, horn, glass, porcelain, are plastic materials which are not reactive to alcohols, ketones and esters, and the products resulting therefrom.

Objects of the present invention areto provide a novel, simple and inexpensive process for metallizing non-metallic substances, particularly plastics, one which may be carried out quickly by an unskilled worker, and one which will produce a durable and relatively inexpensive coating.

The novel process is carried out in the following manner: a bath of acetone, denatured alcohol or iso-propyl alcohol and silver nitrate is first prepared. The alcohol and acetone are mixed in equal amounts, or a mixture of 20 per cent alcohol and 30 per cent acetone may be used, Since silver nitrate is not soluble, in the percentage required in acetone or the alcohols mentioned, it is necessary to first dissolve said nitrate in water. For this, proportions of silver nitrate and water are preferably one gram of silver nitrate to one cubic centimeter of water. The dissolved silver nitrate is now added to the mixture of acetone and alcohol, the percentage of silver nitrate preferably being 10 per cent. If desired, this percentage can be increased to 15 per cent, but it is not deemed advisable to exceed this,

A plain, clean sheet of cellulose nitrate plastic, or other article to be plated, is dipped into this silver bath, which latter is maintained at room temperature. When a period of thirty seconds has elapsed, the plastic is removed from the bath, semi-dried, and then introduced into a reducing solution of sodium hydrosulphite.

This second bath is made by mixing the sodium hydrosulphite with distilled water, the sodium salt forming a 5 to per cent solution. It is highly desirable to use distilled water and not spigot water.

After the plastic to be metallized has remained 2 in the reducing solution for approximately thirty seconds, it is removed and dried, and then is slightly burnished, The article is now ready to be plated in any suitable and well-known manner.

There is thus provided a novel and simple process for metallizing non-metallic substances, and

one which can be rapidly and inexpensively practiced. The resulting plated product is durable and has a wide variety of uses as is understood by those skilled in the art.

What is claimed is:

1. The process of undercoating non-metallic articles for plating that comprises mixing a solution consisting of about 1 g. silver nitrate to 1 cc. water with an alcoholic-acetone mixture, containing between 20 and alcohol, in a proportion yielding from about 10% to about 15% silver nitrate, immersing a said article therein for about one-half minute at room temperature, semi-drying the article, and immersing the article in a solution consisting of 5-10% sodium hydrosulfite in distilled water.

2. The process of undercoating non-metallic articles for plating that comprises mixing a solution consisting of about 1 gram silver nitrate to 1 cc. water with an alcoholic acetone mixture containing between 20 and 50% alcohol, in a proportion yielding from about 10 to about 15% silver nitrate, immersing a said article therein, and immersing the article in a solution of 5-10% sodium hydrosulfite in distilled water.

FREDERICK ROSS WENGER.

REFERENCES crrEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 906,229 Hoessle Dec. 8, 1908 1,834,812 Warren Dec. 1, 1931 2,278,722 Loiseleur Apr. 7, 1942 2,355,933 Weiss Aug. '15, 1944