Cross-linked lignin gels
US4244728A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1976 |
| Grant date | Jan 13, 1981 |
| Priority date | — |
| Expiry date | Feb 3, 1996 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01N25/10
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Disclosed herein are cross-linked lignin gels which have been found useful as pesticide carriers in controlled release pesticide systems. The carrier is a highly reswellable cross-linked lignin gel prepared by reacting alkali lignin with from 1 mole to 10 moles of cross-linking agent, such as formaldehyde, per 1,000 grams of lignin. An aqueous solution of lignin and the cross-linking agent is reacted at elevated temperatures until cross-linking occurs to the point where a discernible increase in viscosity takes place and the gel is formed. The gels are allowed to dehydrate, and the pesticide in an amount from 0.1:1.0 to 2:1 (pesticide to carrier) is included by reswelling the dehydrated gel in an aqueous solution of the pesticide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.