Method of improving coloring agent crocking fastness of polymeric alcohol films

Abstract

Abstract THE OVERCOATING OF A COLORED POLYMERIC ALCOHOL FILM SUBSTRATE, SUCH AS A CELLULOSIC SAUSAGE CASING, WHILE IN THE GEL STATE, WITH A COATING SOLUTION CONTAINING A WATER-SOLUBLE POLYMER HAVING AT LEAST TWO REACTIVE FUNCTIONAL GROUPS THEREIN (E.G. GELATIN, GUM ARABIC, GUM TRAGACANTH, OR EGG ALBUMIN) AND A DIFUNCTIONAL OR POLYFUNCTIONAL CROSS-LINKING AGENT (E.G. DIISOCYANATES OR POLYEPOXIDES, ETC.), FOLLOWED BY HEATING AND DRYING THE COATING TO INSOLUBILIZE THE SAME, IMPROVES THE COLORING AGENT CROCKING FASTNESS AND THE ADHESION OF PRINTING INK SUBSEQUENTLY APPLIED THERETO. THE POLYMER AND CROSS-LINKING GENT IN THE SOLUTION MUST BE COMPATIBLE, I.E. NOT REACTIVE WITH WATER OR WITH EACH OTHER AT AMBIENT TEMPERATURES. A SIMILAR EFFECT CAN BE OBTAINED BY FIRST COATING THE GEL POLYMERIC ALCOHOL FILM SUBSTRATE WITH AN AQUEOUS SOLUTION OF THE WATERSOLUBLE POLYMER AND INSOLUBILIZING THE COATING BY TREATMENT WITH A CROSS-LINKING AGENT IN A SEPARATE STEP.

Inventors

• 👤 Harold R Coleman

Bibliographic Details