Hydroxypropyl methyl cellulose acetate succinate and method for producing the same
US11753483B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 2020 |
| Grant date | Sep 12, 2023 |
| Priority date | — |
| Expiry date | Oct 29, 2040 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L1/32
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
There is provided a method for producing hydroxypropyl methyl cellulose acetate succinate (HPMCAS), including an esterification step of reacting hydroxypropyl methyl cellulose with an acetylating agent and a succinoylating agent in the presence of an aliphatic carboxylic acid in a kneader reactor equipped with two or more stirring blades rotating around their own axes and orbitally revolving, to obtain a reaction product solution containing HPMCAS; a precipitation step of precipitating the HPMCAS by mixing the reaction product solution with water to obtain a suspension of the precipitated HPMCAS; and a washing and recovery step of washing the HPMCAS in the suspension and recovering the washed HPMCAS. Further, there is provided HPMCAS having yellowness at 20° C. of 15.0 or less, as determined in a 2% by mass solution of the HPMCAS in a mixed solvent of dichloromethane, methanol and water in a mass ratio of 44:44:10.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.