GB490109A - An improved method of producing impression foil - Google Patents

Abstract

Relates to impression or embossing foil of the kind in which a film of metal, bronze powder, or colour is attached to a carrier or backing from which it can be stripped prior to or after the impression is made, and consists in employing two contacting layers of cellulose esters which repel each other, as follows: (1) the two layers are interposed between the impression film and the carrier; (2) one layer forms the carrier, and the other is interposed between it and the film; (3) bronze powder or colouring matter is incorporated with one of the layers, and the other is interposed between it and the carrier or itself serves as the carrier. The two layers, which may consist of acetyl cellulose and nitro-cellulose can be separated when the carrier is to be removed. In one method, a thin solution of a cellulose ester in a volatile organic solvent is applied to a paper backing, and, after the film has dried, a mixture of bronze powder or colour with a solution containing another cellulose ester is applied to the film; the second solution must not contain a solvent which will dissolve the cellulose ester in the coating below. A film of metal or a coating of bronze powder is then applied and the finished bronze foil is detached from the carrier. In a modification, one or two layers of metal are formed galvanically on a metal band, a solution of a cellulose ester, which may be coloured with aniline colours, is applied, and a second cellulose ester solution is applied to form a carrier film. The second cellulose ester coating may be a thick one, in which case the metal foil together with the first cellulose ester coating is pulled off the second coating and used as foil for stamping. Specification 428,800, [Group XXII], is referred to.