GB550952A - Manufacture of artificial leather - Google Patents

Abstract

550,952. Polyamides. DU PONT DE NEMOURS & CO., E. I. July 28, 1941, No. 9558. Convention date, July 29, 1940. [Class 2 (iii)] Leather substitutes are obtained by subjecting sheets comprising synthetic linear polyamides to "cold working followed by an embossing or plate-pressure treatment at a temperature above 60‹C. but below the melting point of the polyamide without altering the linear dimensions of the sheet. The term " cold working comprises subjecting the sheets to elongation under compressive or tensile stress, e.g. by passing them between rolls under high pressure or by cold drawing. The polyamides may be prepared as described in Specifications 461,236 and 461,237 and may comprise interpolyamides, ester-amide interpolymers, and carbamates obtained by reacting equimolecular quantities of diisocyanates or diisothiocyanates with a bifunctional diol e.g. decamethylene diisocyanate and decamethylene glycol. In examples (1) an interpolyamide obtained from hexamethylenediammonium adipate and caprolactam is mixed with carbon black and N-ethylo and p-sulphonamides in a mechanical mixer heated to 250‹C. The polyamide is fed to differential speed rolls maintained at 130‹C. and rolled into slabs which are cut into sheets which are rolled in different directions. The sheets are placed in a press having an engraving plate and subjected to pressure at 85-88‹C. The material used may comprise a textile fabric having a polyamide coating or the polyamide sheet may be provided with a flexible backing. Specifications 521,946 and 522,161, also are referred to.