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US 5,466,274 AGranted
Abrasion resistant coatings for fertilizers
AssigneeOMS Investments, Inc.
InventorsAlice P. Hudson, Fred E. Woodward, deceased, by Sam Woodward, executor, Richard J. Timmons, Harvey M. Goertz
Life of this patent
Estimating the term…
Abstract
Polymer topcoated sulfur coated fertilizer compositions are provided which exhibit slow release characteristics and are abrasion resistant, free flowing, non-smearing and essentially dustless products.
Claims14
An abrasion resistant, free-flowing, non-smearing, essentially dustless slow release fertilizer composition consisting essentially of:
- a particulate water soluble fertilizer core having a sulfur coating layer applied directly onto the surface of said fertilizer core,
- said sulfur coating layer being coated with from about 0.75 to about 10 percent (by weight of the fertilizer composition) of a topcoating composition which is essentially non-flowable at ambient temperature and has a melting point of from about 60.degree. C. to about 105.degree. C.,
- said topcoating composition providing a hard ,outer coating over said sulfur coating layer and being non-smearing at ambient temperature whereby said sulfur coated fertilizer composition is rendered essentially dust-free on handling,
- said topcoating composition comprising a mixture of about 5 to about 50 percent (by weight of the topcoating composition) of a polymer and about 95 to about 50 percent (by weight of the topcoating composition) of a hydrocarbon wax;
- said polymer being selected from the group consisting of ethylene-vinyl acetate copolymers;
- ethylene-acrylic acid copolymers;
- ethylene-ethyl acrylate copolymers;
- ethylene-vinyl alcohol copolymers;
- ethylene-vinyl alcohol-vinyl acetate terpolymers and mixtures thereof;
- and
- said hydrocarbon wax being selected from the group consisting of natural petroleum waxes having drop melting points between about 60.degree. C. and 80.degree. C., containing less than about 5% oil as determined by ASTM method D721, and being essentially free of aromatic or cyclic structures;
- synthetic hydrocarbon waxes melting between about 60.degree. C. and 105.degree. C., and having molecular weights between about 400 and 600 and mixtures thereof.
9 more elements
A process for producing an abrasion resistant, free-flowing, non-smearing, essentially dustless slow release particulate fertilizer consisting essentially of:
- providing a quantity of sulfur coated fertilizer particles having the sulfur applied directly onto the surface of said urea particles;
- adding a metered stream of a topcoating composition to said fertilizer particles, either as a molten liquid or as pellets or prills less than 2 mm in diameter, at a temperature of from about 70.degree. C. to about 100.degree. C.;
- said topcoating composition being essentially non-flowable at ambient temperatures and having a melting point of from about 60.degree. C. to about 105.degree. C., said topcoating composition comprising a mixture of about 5 to about 50 percent (by weight of the topcoating composition) of a polymer and about 95 to about 50 percent (by weight of the topcoating composition) of a hydrocarbon wax;
- said polymer being selected from the group consisting of ethylene-vinyl acetate copolymers;
- ethylene-acrylic acid copolymers;
- ethylene-ethyl acrylate copolymers;
- ethylene-vinyl alcohol copolymers, ethylene-vinyl alcohol-vinyl acetate terpolymers;
- and mixtures thereof;
- said hydrocarbon wax being selected from the group consisting of natural petroleum waxes having drop melting points between about 60.degree. C. and 80.degree. C., containing less than about 5% oil as determined by ASTM method D721, and being essentially free of aromatic or cyclic structures;
- synthetic hydrocarbon waxes melting between about 60.degree. C. and 105.degree. C., and having molecular weights between about 400 and 600 and mixtures thereof;
- agitating the mixture of topcoating composition and sulfur coated fertilizer particles in a manner such that a mixing of said mixture is achieved;
- and
- cooling the mixture with agitation to ambient temperature to provide a fertilizer having a hard outer coating applied over said sulfur coating layer which is non-smearing at ambient temperature and said fertilizer is essentially dust-free on handling.
10 more elements
Dependencies are inferred from the claim text.