Method for acetylating shredded cellulosic
US5036900A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1990 |
| Grant date | Aug 6, 1991 |
| Priority date | — |
| Expiry date | Oct 17, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08B1/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Cellulosic sheet material is processed in preparation for esterification for example acetylation to produce cellulose acetate, by treating the sheet material with water and then feeding the wetted material into a machine that simultaneously shreds and dries the material. The conditions in the machine are carefully controlled (outlet temperature not in excess of 110.degree. C. and moisture content 4-15% by weight) to ensure that the cellulosic material does not become deactivated towards esterification. The method enables low alpha content cellulosic material supplied in the form of high density sheet to be acetylated to produce high quality cellulose acetate flake.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.