National Distillers and Chemical Corporation

Karl Koch

John M Hoyt

Mathew Williams, Jr

Joseph Fischer

Tacky ethylene-vinyl acetate copolymers having about 35-95% by weight vinyl acetate content are rendered agglomeration-resistant by surface treatment thereof, before, during, or after forming into particles, with a basic liquid medium to hydrolyze not more than about 10% by weight of the vinyl acetate groups originally present in the copolymer, the hydrolysis being mainly confined to the surface of the particles without effecting any significant hydrolysis of the interior of the particles. Previously agglomerated particles of ethylene-vinyl acetate copolymers containing about 35-60% by weight of vinyl acetate are deagglomerated and rendered agglomeration-resistant by a similar treatment with a basic liquid medium. Non-pelletizable, tacky ethylene-vinyl acetate copolymers containing about 60-95% by weight of vinyl acetate are rendered agglomeration-resistant, and hence pelletizable, at the expense of the hydrolysis of not more than about 10% by weight of the vinyl acetate groups present, by similar treatment before or during particle formation.

Process for rendering ethylene-vinyl acetate copolymers

A process for the hydrolysis of a solid interpolymer of an ethylenically unsaturated hydrocarbon and a vinyl ester of a 2-6 carbon atom aliphatic carboxylic acid to products having a low yellowness index involves contacting of the solid interpolymer with a substantially anhydrous hydrolyzing agent and subjecting at least one of said interpolymer and said hydrolyzing agent to radiation.

Preventing discoloration in hydrolyzed ethylene-vinyl acetate copolymers

Process for controlling the degree of alcoholysis of ethylene-vinyl acetate and other ethylene-vinyl ester interpolymers, by regulating the initial water content of the materials utilized to make up the reaction medium within predetermined limits in order that partially hydrolyzed polymers may be obtained having substantially constant, predetermined residual vinyl acetate or other vinyl ester contents. The partially hydrolyzed products so prepared have uniform, predetermined properties making them particularly useful in film, adhesive, fluidized bed coating, and like applications.

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Cincinnati, OH, United States of America

Karl Koch