Process of preparing waterproof films, fabrics, filaments, and yarns of regenerated cellulose containing within a waterproof addition polymer and products produced therefrom

Claim 1

THE PROCESS FOR THE PREPARATION OF A WATERPROOF REGENERATED CELLULOSE SHAPED OBJECT IN THE FORM OF FILM, FABRIC, OR FILAMENT, WHICH SHAPED OBJECT IS WATERPROOF BUT AT THE SAME TIME IS AT LEAST AS GOOD AS UNMODIFIED CELLULOSE IN ESTHETIC PROPERTIES SUCH AS HAND, FEEL, AND DRAPE, WHICH COMPRISES (1) SUBSTANTIALLY COMPLETELY SAPONIFYING THE CELLULOSE ESTER OF A SO-SHAPED OBJECT OF AN INTIMATE ADMIXTURE OF A CULLULOSE ESTER OF A 1 TO 6 CARBON ALKANOIC ACID AND, PREDOMINANTLY WITHIN AND COEXTENSIVE WITH THE CULLULOSE ESTER, 20-200%, BY WEIGHT OF THE CULLULOSE, OF A WATERPROFF ADDITION POLYMER INERT TO THE SAPONIFICATION CONDITIONS UNTIL THE CELLULOSE ESTER IS SUBSTANTIALLY COMPLETELY SAPONIFIED, THEREBY PRODUCING A NONWATERPROOF OBJECT OF REGENERATED CELLULOSE CONTAINING ABOUT 20-200% BY WEIGHT, BASED ON THE WEIGHT OF THE CELLULOSE, OF SAID WATERPROOF ADDITION POLYMER, SUBSTANTIALLY UNEXTRACTABLE THEREFROM, AND (2) WASHING THE RESULTANT SAPONIFIED SHAPED OBJECT WITH AN ORGANIC SOLVENT FROM THE WATERPROOF ADDITION POLYMER, WHICH SOLVENT IS INERT TO THE CELLULOSE, UNTIL ANY EXTRACTABLE POLYMER IS REMOVED AND A WATERPROOF OBJECT REGENERATED CELLULOSE CONTAINING UNEXTRACTABLE ADDITION POLYMER IS PRODUCED.