| 摘要 |
<p>Granular fertilizer with controlled release of nutrients can be prepared by coating the fertilizer with a mixture consisting of the alkyd resin containing cross-linkable functional groups with mean molecular weight between 500 and 2000 in the amount 30 to 80 % w/w, amino resin in the amount of 1 to 30 % and vegetable oil in the amount of1 to 30 % w/w. The coating mixture contains 66.6 % w/w of alkyd resin, 16.8 % w/w of amino resin, 8.3 % w/w of castor oil and 8.3 % w/w of butylalcohol, and the fertilizer is coated by gradual spraying of 3 to 20 doses of the coating mixture, wherein the coating is performed in the rotary cylindrical container or fluid apparatus at the temperature of 60 to 120 °C. The layer of coating mixture makes 6 to 25 % w/w of the overall weight of the coated granule.</p> |
