METHOD FOR PROVIDING IMPROVED COLLOIDAL STABILITY AND RESULTING POLYVINYL CHLORIDE PRODUCT USING A HOT CHARGE POLYMERIZATION PROCEDURE WITH AN EMULSIFIER PACKAGE

摘要

A method for polymerizing polyvinyl chloride and polyvinyl chloride copolymers is provided in which a monomer slurry is formed by adding the monomers and water (hot or cold) in the reaction vessel, and the slurry is brought to reaction temperature. After a time delay of 0 to 15 minutes, an emulsifier package is added, and after a further time delay of 0 to 15 minutes, a catalyst emulsion is added. The emulsifier package comprises a primary emulsifier which is partially saponified polyvinyl alcohol having a degree of saponification between about 60 and about 90 mole percent and a solubility in methanol index at 55.degree.C in a range of up to about 60 percent. A secondary emulsifier is included in the emulsifier package which is a preferably cellulosic type emulsifier. Preferably an additional emulsifier is added which is a hydrolyzed polyvinyl acetate having an degree of hydrolysis of at least 68 percent. The polymerization product has good bulk density and porosity parameters. Resins produced from this product have low fisheye characteristics.