| 摘要 |
Graft polymers that have been made by the bead-polymerization of a vinyl ester of a monocarboxylic acid, with or without another copolymerizable monomer, in the presence of a polyalkylene glycol that is soluble in water at 50 DEG C. to an extent of up to 10% by weight are subjected to complete or partial hydrolysis and/or alcoholysis in an acid or alkaline medium. The graft polymer used are preferably made by the process described in Specification 935,246. The examples describe treating: (1) a vinyl acetate-polypropylene glycol graft polymer with aethanolic sodium hydroxide, (2) a vinyl acetate-polypropylene glycol graft polymer with a mixture of methanol, methyl acetate and sulphuric acid, (3) a vinyl acetate-oxypropylated tributyl phenol graft polymer with methanolic sodium hydroxide, and (5) a vinyl acetate/diethyl maleate-polypropylene glycol graft polymer with methanolic sodium hydroxide. Specifications 818,037, 857,147 and 922,458 also are referred to. |
