Herbicide-filled cellulose ester particles having controlled release properties
US4111684A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1977 |
| Grant date | Sep 5, 1978 |
| Priority date | — |
| Expiry date | Apr 28, 1997 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01N37/48
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A water-leachable herbicide occupies the voids, or channels, of a particulate, substantially water-impermeable porous cellulose ester carrier which provides controlled release of the herbicide into soil. The herbicide-filled cellulose ester composition can be prepared by the method which comprises: PA1 (a) dissolving cellulose ester in a solvent; PA1 (b) combining the cellulose ester solution with a sufficient amount of a liquid which is a non-solvent for cellulose ester, but miscible with the cellulose solvent, under vigorous agitation to provide a homogeneous liquid containing porous cellulose ester particles having voids, or channels, communicating with the exterior surface thereof; PA1 (c) contacting the cellulose ester particles with a water-leachable herbicide dissolved in a liquid which is a non-solvent for cellulose ester whereby the voids, or channels, of the cellulose ester particles become partially or substantially completely occupied with at least part of the herbicide solution; and PA1 (d) drying the cellulose ester particles. The herbicidal composition can also be prepared by the leaching and pulverizing method fully disclosed in the description of the preferred embo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.