Delignification of wood pulp by vanadium-substituted polyoxometalates
US5302248A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 1992 |
| Grant date | Apr 12, 1994 |
| Priority date | — |
| Expiry date | Aug 28, 2012 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C9/1063
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method for delignifying wood pulp is disclosed. The method comprises the steps of obtaining a wood pulp and exposing the wood pulp to a polyoxometalate of the formula [V.sub.n Mo.sub.m W.sub.l Nb.sub.o Ta.sub.p (TM).sub.q (MG).sub.r O.sub.s ].sup.x- where n is 1-18, m is 0-40, l is 0-40, o is 0-10, p is 0-10, q.ltoreq.6, r.ltoreq.6, TM is a d-electron-containing transition metal ion, and MG is a main group ion, provided that n+m+o+l+p.gtoreq.4 and s is sufficiently large that x>o. The exposure is under conditions wherein the polyoxometalate is reduced. In a preferable form of the invention, the method additionally comprises the step of reoxidizing the polyoxometalate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.