| 摘要 |
Polymers and copolymers having recurring units of structure <FORM:0830189/IV (a)/1> wherein R represents an alkyl or aralkyl radical, are made by reaction of an alkali hypo-halogenite in alcoholic or aqueous-alcoholic medium with polyacrylamide, or by conversion of vinylisocyanates with alcohols and subsequent polymerization of the resulting carbamates, and such polymers and copolymers are subjected to solvolysis to make compounds for use as mordants for acid dyes in colloid compositions (see Group XX). Thus polyacrylamide suspended in methanol and aqueous sodium hypochlorite is left for 3 hours at room temperature whereafter the polymer dissolves, the reaction product is separated by acidifying with hydrochloric acid, and the solvolysis (hydrolysis) of such is effected by refluxing in aqueous hydrochloric acid and precipitation with acetone. A copolymer of benzyl-(N-vinyl)-carbamate and vinyl acetate prepared by heating the monomers with azo-bis isobutronitrile in benzene, and of vinyl isocyanate with alcohol are subjected to solvolysis similarly, and also by heating with hydrobromic or hydrochloric acid in glacial acetic acid, and the precipitated compound is washed with acetone. |
