Core-shell composite particles and methods of making same

Patent metadata

Field	Value
Publication number	US-11970429-B2
Application number	US-202017060908-A
Country	US
Kind code	B2
Filing date	Oct 1, 2020
Priority date	Oct 3, 2019
Publication date	Apr 30, 2024
Grant date	Apr 30, 2024

Abstract

A composite particle is described herein. The composite particle can contain a seed particle of an agricultural treatment material and a shell disposed on the seed particle, wherein the shell comprises a clay.

First claim

What is claimed is:

1. A composite particle, comprising:
a seed particle comprising an agricultural treatment material comprising urea; and
a shell disposed on the seed particle, wherein the shell comprises a clay comprising kaolin, wherein the composite particle has an average cross-sectional length and the seed particle comprises about 30% to about 80% of the average cross-sectional length of the composite particle, and wherein the composite particle has a volume and the shell comprises about 10% to about 40% of the volume of the composite particle.

2. The composite particle of claim 1 , wherein the seed particle further comprises a polymeric material coated onto the agricultural material.

3. The composite particle of claim 2 , wherein the polymeric material is selected from the group consisting of polyurea, polyurethane, polylactic acid, polyvinyl alcohol, chitosan, chitin, phenolic resin, epoxy resin, and combination(s) thereof.

4. The composite particle of claim 3 , wherein the polymeric material comprises polyurea.

5. The composite particle of claim 1 , wherein the composite particle has a volume and the seed particle comprises about 30% to about 80% of the volume of the composite particle.

6. The composite particle of claim 1 , wherein the composite particle has a mass and the seed particle comprises about 30% to about 80% of the mass of the composite particle.

7. The composite particle of claim 1 , wherein the composite particle has a mass and the shell comprises about 10% to about 40% of the mass of the composite particle.

8. The composite particle of claim 1 , wherein the composite particle has an average cross-sectional length and the shell comprises about 10% to about 40% of the average cross-sectional length of the composite particle.

9. The composite particle of claim 1 , wherein the composite particle has a size of about 2 mesh to about 400 mesh.

10. The composite particle of claim 1 , wherein the composite particle has a spherical, oblong, oblate, prolate, egg-shaped, cylindrical, or unsymmetrical shape.

11. A method of making a composite particle, comprising:
atomizing a slurry comprising a clay comprising kaolin into droplets;
coating a seed particle comprising an agricultural treatment material with the droplets to form a green pellet, the agricultural treatment material comprising urea; and
drying a green pellet to form the composite particle, wherein the composite particle has an average cross-sectional length and the seed particle comprises about 30% to about 80% of the average cross-sectional length of the composite particle, and wherein the composite particle has a volume and the shell comprises about 10% to about 40% of the volume of the composite particle.

12. The method of claim 11 , wherein the agricultural treatment material further comprises an absorbent polymer.

13. The method of claim 11 , wherein the atomizing is performed at a temperature of about 25° C. to about 90° C.

14. A method of making a coated composite particle, comprising:
atomizing a slurry comprising a clay comprising kaolin into droplets;
coating a seed particle comprising an agricultural treatment material with the droplets to form a green pellet, the agricultural treatment material comprising urea;
drying the green pellet to form a composite particle; and
coating the composite particle with a biodegradable polymer to form the coated composite particle, wherein the composite particle has an average cross-sectional length and the seed particle comprises about 30% to about 80% of the average cross-sectional length of the composite particle, and wherein the composite particle has a volume and the shell comprises about 10% to about 40% of the volume of the composite particle.

15. The method of claim 14 , wherein the agricultural treatment material further comprises an absorbent polymer.

16. The method of claim 14 , wherein the biodegradable polymer comprises polyvinyl alcohol.

Assignees

• Carbo Ceramics Inc

Inventors

• Hogan Keith
• Canova Steve
• Osby David

Classifications

• C05G5/37 Primary

  layered or coated with a polymer · CPC title

• A01N25/26 Primary

  in coated particulate form · CPC title

• A01N59/06

  Aluminium; Calcium; Magnesium; Compounds thereof · CPC title

• B01J20/12

  Naturally occurring clays or bleaching earth · CPC title

• B01J20/261

  obtained by reactions only involving carbon to carbon unsaturated bonds (macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds per se C08F) · CPC title