Polymer coated fertilizer
US10562827B1 · kind B1 · utility
Inventors
Key dates
| Filing date | Sep 10, 2019 |
| Grant date | Feb 18, 2020 |
| Priority date | — |
| Expiry date | Sep 10, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC05G5/37
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A controlled release fertilizer has been prepared comprising a nutrient core coated with one or more moisture barrier coatings, at least one of said moisture barrier coatings comprising: at least one polyethylene wax; and a thermoset polyurethane from the reaction of a polyol and a polyisocyanate. The weight ratio of thermoset polyurethane to polyethylene wax is from about 50:50 to about 98:2. The polyethylene wax is heated above the melt point of the polyethylene wax and mixed and dispersed into the polyol component of the thermoset polyurethane in a ratio of 90-70% polyol to 10-30% polyethylene wax before the thermoset polyurethane-forming mixture is applied to the surface of the nutrient core and cured. A coating of a high temperature microcrystalline wax can be applied prior to final curing of the thermoset polyurethane to the coated nutrient core particles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.