One-step method of coating nutrient particles
AssigneeMelamine Chemicals, Inc.
InventorWilliam P. Moore
Life of this patent
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Abstract
A one-step method of preparing coated particulate plant nutrients wherein a polyfunctional coupling agent is applied to a mobile mass of plant nutrient particles containing functional groups which are chemically reactive with the functional groups of the coupling agent, while simultaneously applying a second reactive material containing functional groups also reactive with the functional groups of the coupling agent, maintaining the mobile mass at a temperature between 30.degree. C. and 300.degree. C. until a strong, water-insoluble particle. The product of the one-step method is a controlled-release plant nutrient having excellent attrition resistance.
Claims27
A method for producing attrition-resistant coated particulate plant nutrients, comprising
- (a) applying a polyfunctional coupling agent to a mobile mass of plant nutrient particles which contain at least 10 percent of reactive functional groups which are chemically reactive with the functional groups of said coupling agent;
- (b) applying substantially simultaneously a second reactive material containing functional groups reactive with the functional groups of the coupling agent to the mobile mass of nutrient particles of (a);
- and
- (c) holding the mobile mass of plant nutrient particles at a temperature of between 30.degree. C. and 200.degree. C. unit the polyfunctional coupling agent chemically bonds with the reactive functional groups at the surface of the particulate plant nutrients, and also reacts with the functional groups of the second reactive material to form a strong, substantially homogeneous, water-insoluble coating.
A one-step method of producing attrition-resistant, controlled-release particulate nitrogen fertilizers, comprising
- (a) spraying polymeric diphenylmethane diisocyanate, containing between 15 and 31 percent NCO groups onto a mobile mass of nitrogen fertilizer particles exhibiting U.S. Mesh sizes between 4 and 30 and containing between 10 and 53 percent reactive amine functional groups;
- (b) simultaneously spraying and blending onto the mobile mass of fertilizer particles of (a) above, between 1.0 and 1.5 parts of an anhydrous organic polyol containing between 5 and 55 percent hydroxyl groups, and between 5 and 15 percent triethanolamine;
- and
- (c) holding the mobile mass of nitrogen fertilizer particles at a temperature of between 85.degree. C. and 115.degree. C. for a period of time between 2 and 10 minutes until the diphenylmethane diisocyanate has chemically bonded with the amine functional groups at the surface of the nitrogen fertilizer particles and polymerized with the hydroxyl groups in the second reactive material to form a strong, water-insoluble coating sufficient to control nitrogen release from the fertilizer particles.
Dependencies are inferred from the claim text.