Process for preparing extrudable polymeric vinylidene chloride composition

A process for preparing a vinylidene chloride polymer composition having improved extrudability comprising the steps of:

• (A) forming a polymerizable monomer mixture having an aqueous phase and a monomer phase, the monomer phase comprising from about 60 to about 99 weight percent of vinylidene chloride monomer and from about 40 to about 1 weight percent of at least one ethylenically unsaturated comonomer selected from the group consisting of vinyl chloride, alkyl acrylate, alkyl methacrylate, acrylic acid, methacrylic acid, itaconic acid, acrylonitrile and methacrylonitrile;
• (B) adding from about 0.001 to about 10 weight percent, based on the weight of the monomer mixture or polymer slurry, of at least one nonalkenic weak acid salt selected from the group consisting of alkali or alkaline earth metal phosphates, alkali or alkaline earth metal carboxylates, alkali or alkaline earth metal borates, alkali or alkaline earth metal alkyl phosphates, alkali or alkaline earth metal aryl phosphates, alkali or alkaline earth metal alkyl phosphites, alkali or alkaline earth metal aryl phosphites, alkali or alkaline earth metal alkyl sulfates and alkali or alkaline earth metal aryl sulphates to the polymerizable mixture in step (A) or to the polymer slurry in step (C);
• (C) polymerizing the polymerizable mixture to form a polymer slurry having an aqueous phase and a monomer phase;
• (D) maintaining the pH of the aqueous phase of the polymer slurry at an effective value to provide hydrolyzed salt species of the nonalkenic weak acid salt;
• and
• (E) drying the slurry to form a polymeric composition containing from about 0.01 to about 5 weight percent of the hydrolyzed salt species of the nonalkenic weak acid salt.