Oxidative delignification of wood or wood pulp by transition metal-substituted polyoxometalates
US5552019A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Mar 28, 1994 |
| Grant date | Sep 3, 1996 |
| Priority date | — |
| Expiry date | Mar 28, 2014 |
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 and fiber 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.l Mo.sub.m W.sub.n Nb.sub.o Ta.sub.p (TM).sub.q X.sub.r O.sub.s ].sup.x- where l is 0-18, m is . 0-40, n is 0-40, o is 0-10, p is 0-10, q is 0-9, r is 0-6, TM is a d-electron-containing transition metal ion, and X is a heteroatom, which is a p or d block element, where l+m+n+o+p.gtoreq.4, l+m+q>0 and s is sufficiently large that x>0. 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.