Integrated-preparation and application methods of urea-formaldehyde (UF)-based multi-nutrient biodegradable polymeric slow-release (SR) liquid and granular fertilizers
US12428355B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 16, 2025 |
| Grant date | Sep 30, 2025 |
| Priority date | — |
| Expiry date | Jan 16, 2045 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC05G5/20
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method for integrally preparing urea-formaldehyde (UF)-based multi-nutrient biodegradable polymeric slow-release (SR) liquid and granular fertilizers is provided. A hydroxymethylurea solution is prepared, and a part of the hydroxymethylurea solution is added to a reactor for reaction to obtain the UF-based multi-nutrient biodegradable polymeric SR liquid fertilizer. The rest of the hydroxymethylurea solution is fed into a reaction-extrusion integrated machine for reactive extrusion to obtain a UF polymer through the polycondensation reaction, which is extruded, dried and granulated to obtain the UF-based multi-nutrient biodegradable polymeric SR granular fertilizer. A method for applying such liquid and granular fertilizers is also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.