| 发明名称 |
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| 摘要 |
1412290 Divinyl ether-maleic anhydride copolymers HERCULES Inc 20 Dec 1972 [22 Dec 1971] 58929/72 Heading C3P [Also in Division A5] A solid cyclic copolymer of divinyl ether and maleic anhydride having recurring units of formula and in the form of a composition having a range of molecular weights, the copolymers in the composition having a number average molecular weight of from 5000 to 30,000 and a ratio from 1.0 to 3.0 when determined by gel permeation chromatography carried out on the methyl ester derivative of the copolymer may be prepared by selectively treating the copolymers to discriminate between lower and higher molecular weight copolymers and thereby select the number of units in the copolymer molecules and conducting the selection to provide a product having the required number average molecular weight and ratio. The selective treatment may be (i) fractionating a copolymer composition having a range of molecular weights and selecting appropriate fractions, (ii) degrading copolymers having non-selected molecular weights or (iii) controlling the formation of the copolymers to have molecular weights such that the product lies within the selected limits. In Examples 1 and 9, polymers of particular molecular weights are prepared by sand column fractionation or by direct solution polymerization of maleic anhydride and divinyl ether in tetrahydrofuran while irradiating with a sunlamp. |
| 申请公布号 |
DE2262449(B2) |
申请公布日期 |
1980.02.28 |
| 申请号 |
DE19722262449 |
申请日期 |
1972.12.20 |
| 申请人 |
HERCULES INC., WILMINGTON, DEL. (V.ST.A.) |
发明人 |
BRESLOW, DAVID SAMUEL, WILMINGTON, DEL. (V.ST.A.) |
| 分类号 |
C08F6/00;A61K31/765;A61K47/48;A61P31/12;A61P35/00;C08F6/06;C08F8/48;C08F16/00;C08F16/32;C08F20/00;C08F20/02 |
主分类号 |
C08F6/00 |
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