Process for the production of cellulose acetate from wood pulp
US5114535A · kind A · utility
6Cited by
9References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1991 |
| Grant date | May 19, 1992 |
| Priority date | — |
| Expiry date | Mar 19, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08B3/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for making cellulose acetate from wood pulp takes wet wood pulp and instead of converting it into dry pulp sheet which is the usual feedstock for acetate, dries and mechanically separates the pulp into a cellulose flock using a pin mill through which a hot drying gas is passed. Deactivation of the cellulose is avoided by control of the drying gas exit temperature to 80.degree. C. to 95.degree. C. and of the moisture content of the cellulose flock to 4 to 15% by weight. The flock produced may be acetylated directly without any need for reactivation treatments additional to the normal activation with acetic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.