Method of manufacturing polyvinyl alcohol

Claim 1

THE METHOD OF PREPARING LINEAR POLYVINYL ALCOHOL HAVING A NARROW RANGE OF MOLECULAR WEIGHT DISTRIBUTION WHICH COMPRISES SUBJECTING VINYL ACETATE IN A HOMOGENEOUS SYSTEM CONTAINING AN ALCOHOL DILUENT TO POLYMERIZING CONDITIONS OF A TEMPERATURE LESS THAN 50*C. AND AT A PRESSURE LESS THAN 500 MM. HG IN THE PRESENCE OF A CATALYTIC AMOUNT OOF A POLYMERIZATION CATALYST, SAID CATALYST BEING A MEMBER SELECTED FROM THE GROUP CONSISTING OF ORTHO CHLOROBENZOYL PEROXIDES, ORTHO ALKOXY BENZOYL PEROXIDES, AZO NITROLES, AND REDOX CATALYSTS COMPRISING AN ACTIVATOR AND AN INITIATOR, POLYMERIZING SAID VINYL ACETATE TO A DEGREE OF CONVERSION OF MONOMER TO POLYMER NOT EXCEEDING 70%, AND DURING THE POLYMERIZATION BY VAPROIZAOUSLY REMOVING THE HEAT OF POLYMERIZATION BY VAPORIZATION OF MATERIAL FROM THE POLYMERIZATION MIXTURE SELECTED FROM THE GROUP CONSISTING OF SAID VINYL ACETATE, SAID DILUENT, AND MIXTURES THEREOF, AND SAPONIFYING THE POLYMERIZED VINYL ESTER TO FORM POLYVINYL ALCOHOL.