Granular fertilizer with a multilayer coating
US5645624A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1994 |
| Grant date | Jul 8, 1997 |
| Priority date | — |
| Expiry date | Nov 29, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC05G5/37
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention provides a granular fertilizer with a multilayer coating comprising a first layer containing at least one rapidly biodegradable polymer selected from the group consisting of a rapidly biodegradable aliphatic polyester and a rapidly biodegradable polyurethane compound, and a water-insoluble second layer containing at least one slowly biodegradable polymer selected from the group consisting of a slowly biodegradable cellulose derivative, low molecular weight polyethylene, low molecular weight wax and low molecular weight paraffin or light-degradable resins. The granular fertilizer with a multilayer coating of the present invention is characterized in that it is coated with coating materials having different dissolving-out rates, that dissolving-out of the fertilizer nutrients is controlled, and that the coating does not persist after the nutrients are dissolved out. Accordingly, the granular fertilizer coated with a multilayer of the present invention has less damaging effects on nature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.