| 摘要 |
<p>A plasticized polyvinyl acetal composition having a moisture content of 0.1 to 0.8% by weight and containing sufficient potassium formate or sufficient of one or more potassium salts of saturated aliphatic monocarboxylic acids having from 3 to 22 carbon atoms to produce an alkalinity titer (defined) of 25 to 40 or sufficient of one or more potassium salts of saturated aliphatic dicarboxylic acids having from 4 to 9 carbon atoms to produce an alkalinity titer of at least 10 and less than 60, is obtained by swelling a polyvinyl acetal resin in a mixture of alcohol and water at 40 DEG C. for about 1 hour and washing with water until the resin has substantially zero alkalinity titer, then adding to an aqueous slurry of the resin sufficient potassium salt to produce the desired alkalinity titer, adjusting the moisture content of the polyvinyl acetal and plasticizing the polyvinyl acetal. The polyvinyl acetal is preferably polyvinyl butyral. Plasticizers used are triethylene glycol di(2 - ethyl butyrate), dibutyl sebacate and di(betabutoxy ethyl) adipate.</p> |
