Process for preparing granular graft copolymers

Abstract

Abstract IN A PROCESS FOR PREPARING A GRANULAR GRAFT COPOLYMER FROM A LATEX OF GRAFT COPOLYMER PRODUCED BY THE EMULSION GRAFT POLYMERIZATION OF 70-5 PARTS OF VINYL CHLORIDE ONTO 30-95 PARTS OF AN ETHYLENE/VINYL ESTER COPOLYMER THROUGH THE SALTING-OUT, DEHYDRATING AND DRYING STEPS, THE GRAFT COPOLYMER IS HEAT TREATED AT ANY STEP PRIOR TO THE DEHYDRATING STEP AT A TEMPERATURE OF 60*-110*C. UNDER THE CONDITION THAT THE VALUE (HEATING TIME) 1/2 X (HEATING TEMPERATURE -30) 2 (MIN. 1/2.0 C.2) FALLS WITHIN THE RANGE OF 2,000 TO 20,000 AND THE GRAFT COPOLYMER IS DEHYDRATED AT A TEMPERATURE LOWER THAN 60*C. BUT HIGHER THAN 0*C. THEREBY THE GRAFT COPOLYMER CAN BE DEHYDRATED AND DRIED MUCH MORE CONVENIENTLY THAN IN THE CONVENTIONAL PROCESSES, AND THE GRANULAR DRY GRAFT COPOLYMER THUS OBTAINED CAUSES FAR LESS ODOR OF FATTY ACID DURING A LONG PRESERVATION OR USE COMPARED TO THE CONVENTIONAL ONES. SUCH IMPROVEMENTS ARE PROMOTED FURTHER BY ADDING A MG, C, ZN, SR, CD, BA OR PB SALT OF A HIGHER FATTY ACID TO THE GRAFT COPOLYMER AT ANY STEP PRIOR TO THE DRYING STEP.

Inventors

• 👤 Kosaku Kamio
• 👤 Motoyuki Kuwana
• 👤 Atsushi Takahashi
• 👤 Masao Sahara

Bibliographic Details