GB319294A - Improvements in and relating to artificial silk and like filamentary material - Google Patents

Abstract

319,294. Field, C. H., and Haslett, D. June 13, 1928. Cellulose acetate, cellulose nitrate, and cellulose xanthate, processes. for making filaments from.-Artificial silk and like filaments are prepared from a mixture of cellulose xanthate with cellulose acetate and/or with cellulose nitrate dissolved or dispersed in a. solvent or solvent mixture comprising monochlorhydrin, dichlorhydrin, epichlorhydrin, one of the acetins or like esters of glycerine, or glycerine itself, or mixtures of any two or more of these compounds; other solvents such as acetone or amyl acetate may be present also. For example a solution constituted as described above may be extruded into a bath comprising hydrochloric acid and ammonium chloride; if epichlorhydrin is present in the solvent, it is converted by the bath into dichlorhydrin and can be regenerated by treatment with alkali. It is preferred to use cellulose xanthate containing a minimal proportion of water. Thus. a xanthate sol prepared in known manner may be exposed to the air so as to effect spontaneous coagulation, the use of precipitants being avoided, and mav be treated with monochlorhydrin and/or dichlorhydrin so as to displace a further proportion of water. According to the example, cellulose acetate and cellulose nitrate are dissolved separately in epiohlorhydrin, and cellulose xanthate is dissolved in a mixture of glycerine, and dichlorhydrin; the xanthate solution is mixed with the acetate solution and/or with the nitrate solution and the mixture is extruded into a bath comprising specified amounts of hydrochloric acid and ammonium chloride.