| 摘要 |
A linear copolymer consisting essentially of recurring units of the formul <FORM:0788955/IV (a)/1> wherein X or Y is hydroxyl and the other an amino radical or trialkylamino cation radical, i.e. a radical of the formula <FORM:0788955/IV (a)/2> and which copolymer comprises 94 to 51 per cent by weight of the first unit and 6 to 49 per cent by weight of the second unit and 0 to 2 per cent of vinyl ester groups are made by reacting a copolymer of allyl glycidyl ether and a vinyl ester containing 3 to 30 per cent of the ether and 70-99 per cent of the ester with ammonia or a monoamine and hydrolysing residual ester groups to hydroxyl groups. Suitable copolymeric starting materials, e.g. vinyl acetate, are described in Specification 722,258 and U.S.A. Specification 2,676,166. Specified monoamines are ethyl, propyl, butyl, pentyl and benzylamines, dipropyl, dibutyl, and diamylamines, tri-n-octylamine 2-ethylpyridine, and dimethylaminodimethylacetamide. The hydrolysis is preferably effected by heating the aftertreated copolymer with alcoholic alkali or an alkali metal alcoholate, e.g. sodium alcoholate in an alcohol such as methanol, ethanol, isopropylalcohol and a small quantity of water. The treatment with the monoamine is effected with the copolymer in solution, e.g. dissolved in methyl ethyl ketone. The hydrolysed copolymers are used as water-permeable colloid binding agents in filter and anti-halation layers in photographic films, textile sizing agents, and in silver halide dispersions or emulsions. Specifications 535,341, 546,459, 551,659, 598,477, [all in Group XX], and 747,801, [Group III], also are referred to. |
