| 摘要 |
1409280 Partial alkylene glycol ether esters of copolymers ELI LILLY & CO 11 Oct 1972 [12 Oct 1971] 46757/72 Heading C3P [Also in Division A5] A partial alkylene glycol ether ester of a copolymer having as monomers a C 1 -C 4 alkyl acrylate and an unsaturated polybasic carboxylic acid anhydride, a molecular weight of at least 14,000 and comprising structural units of formula or wherein R 1 is C 1 -C 4 alkyl, R 2 is hydrogen or methyl, R 3 and R 4 are hydrogen or the moiety wherein R 5 is hydrogen or diethyl and R 6 is C 1 -C 4 alkyl, with the proviso that from 10 to 50% of the R 3 and R 4 groups are other than hydrogen, q is a whole number from 1 to 4 and x and y are whole numbers from 1 to 5 may be prepared by copolymerizing a C 1 -C 4 alkyl acrylate and an unsaturated polybasic carboxylic acid anhydride in a mole ratio of from 1 : 5 to 5 : 1 and esterifying the copolymer thus obtained with a C 1 -C 4 alkyl ether of a C 2 or C 3 alkylene glycol having from 1 to 4 alkylene units such that from 10 to 50% of the available carboxylic acid moieties of the copolymer are esterified with one ether. A coating composition for entenic medicaments comprises a mixture of such an ester and a partial C 1 -C 4 alkanol ester of the same copolymer. |
