Method for forming cellulose
US6921820B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 20, 2002 |
| Grant date | Jul 26, 2005 |
| Priority date | — |
| Expiry date | Sep 20, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249921
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method for forming II-type cellulose, which comprises introducing together a slurry having water and a I-type cellulose dispersed therein and water in the state of high temperature and high pressure to a tubular reactor (28) contacting the I-type cellulose with a hot water in a supercritical state or subcritical state for a predetermined time in the tubular reactor (28), to thereby cleave a part of the hydrogen bonds in the I-type cellulose and dissolve the I-type cellulose into the water in a supercritical state or subcritical state, cooling a cellulose solution discharged from the tubular reactor (28) in a cooler (30) to room temperature or lower, followed by allowing to stand, to thereby precipitate crystals of II-type cellulose having a molecular weight lower than that of the I-type cellulose, and separating the resultant II-type cellulose from a solvent. The method allows the preparation of pure II-type cellulose by the use of a simple process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.