US1558853A - Process for the metallization of porcelain or glass - Google Patents

Description

Patented 0a. 27, 1925.

UNITED STATES PATENT orrica.

AIPHONSE FLORENT nIJssnn, or HEERLEN, NETHERLANDS...

rnocnss' non THE rrnrnnmzarlon or PORCELAIN on GLASS.

No Drawing.

To all whom it may concern:

Be it known that I, 'ALPHONSE FLoRnNT EIJSSEN, a subject of the Queen of Holland, residing at Heerlen, Province of Limburg, Kingdom of the Netherlands, have invented an. Improved Process for the Metallization of Porcelain or Glass, of which the fola coatin of alkali silicate and then with a coating containing KCN,NH,F1 and AgCl.

This coating is reduced with hydrazine, the reduction of the silver being completed by brushing with a metal brush (of copper, brass, iron, zinc, etc.).

According to the invention in order to obtain a metallized conducting surface without using a silver salt, glycerol is rubbed with a brush of brass r similar material on to the surface of the object to be metallized, by which treatment a deposit of. brass is obtained on the, porcelain or 'glass, which is made conducting in this manner. A little nitrate of silver may be added to theglycerol when silver is, desired in the deposit. Generally however this is notrequired. In lieu of glycerol also other viscous polyvalent alcohols may beused such as glycol and the like. I In order to cover such a metallized surface with more metal, it is connected by means of a copper wire to the negative pole of a dynamo or a galvanic battery, the positive pole of which is connected to a copper plate which is placed with'the object to be metallized in a solution of e. g.

1 liter water.

200 grams sulphate of copper.

20 grams sulphuric acid of 66 B.

Then an electric'current is passed of a density of about 5 amperes per square decimeter of the surface to be metall zed.

For applying the invention, the surface to' be treated must first be dulled, -e. g. by means of a sand blast machineiworkingat a pressureof per sq. cm. and fine white sand. The'dulled surface is rubbed with a very small quantity of glycerol using a brass brush. It will be observed immediately that a very adherent deposit of brass Application filed December 12, 1924. Serial No. 755,580.

is obtained on the porcelainor glass, and care must be taken torub the dulled glass with the brass brush until the surface is quite dry so that it has a dark green appearance. If too much glycerol is used good adhesion of the metal to the treated object cannot be obtained.

, After this treatment, the rubbed surface of the object has wrapped round it or ap plied'to it by a copper wire which is connected to the negative pole of a source of current, the positive pole of which is connected to a copper plate immersed in the same bath. as the object'to be metallized, said bath being filled with a solution of copper sulphate of about the above mentioned composition. The bath is electrolyzed at a temperature of 14;"20 G. and a current density of 5 amp. per square decimeter of the rubbed surface. After a few minutes it is observed that the rubbed part is covered with a layer offcopper. When the objects are metallized sufficiently, they. are removed from the bath and polished.

They may be afterwards covered with sllver or nickel in the usual way.

In the manner described one may e. g.

metallize the outside of porcelain kettles.

Such kettles have the advantage that they do not burst, are less subject to breakage and remain hot for a longer period than ordinary porcelain kettles. Porcelain cans for coffee, tea or milk may be treated according to the invention to protect them against breakage. Such metallized objects of glass orporcelain compared with similar metal objects have the advantage that they do not leave a metal taste when in use and can be cleaned very easily. They have therefore hygienic advantages. sible to use the invention for ornamental purposes. I

What Iv claim is:

1. A process for metallizing a dull surface of non-conducting hard material comprising rubbing the surface with a very smallquantity of a viscous polyvalent alcohol by means of a metal brush and then depositing electrolytically a further -meta1 coating.

2. In a process for metallizing a dull sur-- face of non-conducting hard material the step of rubbing the surface with a very small quantity of glycerol by means of a metal brush.

3. In a process for metallizing a dull sur- 6 It 1s, also posface of non-conducting hard material the step of rubbing the surface with a very small quantity of. glycerol by means of a brass brush.

4. A process according to claim in which nitrate of silver is added to the glycerol. 5. A process for metallizing objects of nnglazed porcelain comprising rubbing the surface to be metallized with avery small quantity of glycerol by means of a brass 10 brush, connecting the objectby means of a copper wire to the negative pole of an elec- 'lric machine. while the ()lJJGCt 1S immersed ALPHON bE FLOREN EIJ SSEN.