Manufacture of solutions of a polymerized vinyl compound

Aqueous solutions of polymeric compounds of the vinyl series are prepared by dissolving the polymeric compound in a substantially saturated aqueous solution of a salt derived from a monobasic acid and a metal of groups I, II or III, the salt being capable of forming aqueous solutions of at least 50 per cent strength at ordinary temperatures. The solutions, which may also contain polymeric carbohydrate such as cellulose, cellulose ester or ether, polypeptides such as fibroin, a filling agent, pigment or softening agent, may be used in the manufacture of threads, films, sheets or other shaped articles. In examples: (1) polyacrylic nitrile is dissolved in aqueous lithium bromide to form a solution which can be ejected from jets or slits to form threads or films; (2) polyacrylic nitrile is dissolved in aqueous zinc chloride, sodium sulphocyanide or in aqueous lithium bromide containing hydrated cellulose and silk waste; (5) a polyvinyl formal is dissolved in aqueous aluminium perchlorate; (6) a condensation product of polyvinyl alcohol and butyraldehyde is dissolved in aqueous calcium sulphocyanide; (7) interpolymers of acrylic acid and methyl acrylate, vinyl chloride and acrylic nitrile and methyl acrylate and acrylic nitrile are dissolved, respectively in aqueous cadmium bromide, calcium sulphocyanide or calcium perchlorate. The Provisional Specifications refer in general terms to the use of concentrated aqueous solution of metal salts as solvents for the polymers.