Alkaline soluble mixture composed of cellulose derivatives

摘要

One object of the present invention is to provide a mixture composed of 1) a cellulose ether derivative esterified at least with a biprotic acid group derivative expressed by the formula HOOC-B-COOH (I), wherein B is a linear aliphatic group represented by (CH2)x with x a positive integer from 1 to 5 or is a 5-member or 6-member cycloaliphatic group and 2) a cellulose or cellulose derivative esterified at least with a phthalic acid derivative represented by the following formula (II). wherein R1 is an alkyl group and y is a positive integer from 0 to 3. Said mixture shows an enhanced stability against hydrolysis when subjected to conditioning at high relative humidity and temperature. The composition may be useful in order to get antihalation layer on photographic films as well as enteric coating of pharmaceutical dosage and for controlled-release applications such as for cleaning formulation.