GB274841A - Improvements in or relating to the application of cellulose esters and ethers, and products thereby obtained - Google Patents

Abstract

274,841. British Celanese, Ltd., (Assignees of Schneider, G., and Dreyfus, C.). July 23, 1926, [Convention date]. Yarns and threads, treating with liquids.-A process for coating threads or other articles or objects made of or containing or having a surface of cellulose acetate or other fatty acid esters or ethers of cellulose consists in applying to the articles or objects a solution of cellulose acetate or other fatty acid ester or ether of cellulose in which the solvent used is a non-solvent for the ester or ether present in or on the article or object to be coated. The process may be applied to the protection of hygroscopic cellulose ester surfaces, by coating with a solution of a non-hygroscopic cellulose derivative, to the production of metallic, coloured, or decorative effects by the use of metal powders, pigment or other materials, or for the protection of the effect obtained by rubbing crystals of metallic salts on the articles to be coated. As the same ester of cellulose may be prepared in several phases of different solubilities, a base of cellulose acetate which is soluble in acetone but inosloluble in chloroform or ethyl acetate may receive a coating of cellulose acetate soluble in chloroform or ethyl acetate. Examples of the application of the process are as follows. Permanent metallic effects are produced on fabrics, &c. by first producing a dark polished surface by means of a coating of a solution of cellulose acetate in acetone, preferably dyed black by nigrosine. The cellulose acetate used is insoluble in ethyl acetate and insoluble in or only slightly softened by chloroform. A metallic effect is produced on this surface by rubbing with fine crystals of bismuth or antimony oxychlorides and the effect is made permanent by coating with a clear solution of cellulose acetate in ethyl acetate or chloroform. For the production of an iridescent metallic effect, the protective coating in the foregoing example is applied as several coatings of a very dilute solution of the cellulose ester. Filaments or threads of cellulose acetate artificial silk are treated with a dilute solution of a fatty acid ester or ether of cellulose dissolved in benzene, which is a non-solvent for the cellulose acetate, and containing bronze or other metallic powder. The Specification as open to inspection under Sect. 91 (3) (a) refers to esters and ethers of cellulose other than fatty acid esters and ethers, and in particular to nitro-cellulose. It also refers to Specification 271,425, [Class 140, Waterproof &c. fabrics]. This subject-matter does not appear in the Specification as accepted.