Hypromellose phthalate and method for producing the same
US10934369B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 2019 |
| Grant date | Mar 2, 2021 |
| Priority date | — |
| Expiry date | May 9, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08B13/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
There is provided a method for producing hypromellose phthalate (HPMCP) which exhibits an excellent solubility when dissolved in a solvent, while suppressing formation of undissolved matter. More specifically, there is provided a method for producing HPMCP, including an esterification step of esterifying hypromellose dissolved in glacial acetic acid with phthalic anhydride in the presence of sodium acetate at a temperature of from 75 to 100° C. to obtain a reaction product solution; a cooling step of cooling the reaction product solution to 70° C. or lower; and a precipitation step of mixing the cooled reaction product solution with water of from 0 to 40° C. to obtain a suspension of precipitated HPMCP.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.