Method of producing cellulose carbamate
US4567255A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 1985 |
| Grant date | Jan 28, 1986 |
| Priority date | — |
| Expiry date | Mar 12, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08B15/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention is directed to a procedure for manufacturing cellulose carbamate by reacting isocyanic acid and cellulose at elevated temperature. In the procedure, cellulose, to which biuret or a mixture of biuret and urea has been admixed or absorbed, is heated at a temperature over 170.degree. C. for a sufficient time to produce a quantity of isocyanic acid sufficient for formation of the cellulose carbamate and for accomplishing the reaction between cellulose and isocyanic acid. The heating is accomplished at 170.degree.-250.degree. C., preferably at about 220.degree. C. The biuret quantity is 3-50% by weight of the cellulose weight and the urea quantity is 0-95% by weight of the cellulose weight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.