Low-substituted hydroxypropyl cellulose and process for manufacturing the same
US6680069B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 6, 2000 |
| Grant date | Jan 20, 2004 |
| Priority date | — |
| Expiry date | May 2, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08B11/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Processes for manufacturing a low-substituted hydroxypropyl cellulose are described that include dipping pulp into an alkaline solution to prepare an alkali cellulose, reacting the alkali cellulose with a hydroxypropylating agent to yield a product in a complete dissolution state, dissolving completely the product in an aqueous medium to provide a product in a complete dissolution state, neutralizing with an acid to yield a precipitate, washing, drying, and pulverizing to yield a powder having a volume-average particle diameter of less than 25 microns which is determined by a dry laser diffraction method, a loose bulk density of 0.29 g/ml or more and less than 0.40 g/ml, and a tapped bulk density of 0.55 g/ml or more. Low-substituted hydroxypropyl celluloses are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.