Sintered herbicide-filled cellulose ester particles having improved resistance to water leaching
US4106926A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 28, 1977 |
| Grant date | Aug 15, 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 controlled-release composition comprising discrete particles of water-leachable herbicide occupying the voids, or channels, of a particulate, substantially water-impermeable, porous, cellulose ester carrier is provided with enhanced resistance to water leaching of the herbicide component thereof following sintering of the herbicide contained in the composition. 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 non-solvent for cellulose ester, but miscible with the cellulose ester 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 having a sintering temperature below the softening temperature of the cellulose ester, said herbicide being 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 su…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.