Alkaline soluble mixture composed of cellulose derivatives
US6261752A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 13, 2000 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Jan 13, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC11D17/0039
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
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 (CH.sub.2).sub.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). ##STR1## wherein R.sub.1 is an all group and y is a positive integer from 0 to 3. PA1 Said mixture shows an enhanced stability against hydrolysis when subjected to conditioning at high relative humidity and temperature. PA1 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.