Encapsulated fertilizer particle containing pesticide

Patent metadata

Field	Value
Publication number	US-9944568-B2
Application number	US-201314443090-A
Country	US
Kind code	B2
Filing date	Nov 15, 2013
Priority date	Nov 16, 2012
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

An encapsulated particle comprises a core particle, a transferrable-pesticide disposed about the core particle, and a polyurethane layer disposed about the transferrable-pesticide. The core particle comprises a fertilizer, such as urea. The transferrable-pesticide can comprise a dinitroaniline, such as pendimethalin. The polyurethane layer is generally formed from a reaction mixture having a maximum temperature of no greater than about 30° C. The polyurethane layer inhibits the transferrable-pesticide from transferring to a surface different from the core particle when the encapsulated particle physically contacts the surface. A method of forming the encapsulated particle comprises the steps of encapsulating the core particle with the transferrable-pesticide to form an intermediate-particle, combining an isocyanate and a polyol to form the reaction mixture, and encapsulating the intermediate-particle with the reaction mixture to form the polyurethane layer of the encapsulated particle. The polyurethane layer comprises the reaction product of the isocyanate and polyol.

First claim

What is claimed is:

1. An encapsulated particle comprising:
a core particle comprising a fertilizer;
a transferrable-pesticide having a vapor pressure of at least about 3 mPa at 25° C. and disposed about and in contact with said core particle; and
a polyurethane layer having a glass transition temperature (Tg) of at least about 80° C., said polyurethane layer disposed about said transferrable-pesticide;
wherein said polyurethane layer comprises the reaction product of an isocyanate and a polyol, and wherein the maximum temperature of a reaction mixture of said isocyanate and said polyol is no greater than about 25° C. during formation of said polyurethane layer.

2. The encapsulated particle as set forth in claim 1 , wherein said polyurethane layer:
i) comprises the reaction product of an isocyanate and a polyol; and
ii) is free of catalyst(s).

3. The encapsulated particle as set forth in claim 2 , wherein said polyol comprises the reaction product of i) an alkylene oxide having from 2 to 4 carbon atoms and ii) glycerol.

4. The encapsulated particle as set forth in claim 2 , wherein said polyol has:
i) a hydroxyl number of from about 200 to about 600 mg KOH/g; and/or
ii) a viscosity of from about 100 to about 1,000 cPs at 25 ° C.; and/or
iii) a number average molecular weight (Mn) of from about 200 to about 600 g/mol.

5. The encapsulated particle as set forth in claim 1 , wherein said transferrable-pesticide comprises a dinitroaniline.

6. The encapsulated particle as set forth in claim 1 , wherein said core particle comprises urea.

7. An encapsulated particle comprising:
a core particle comprising a fertilizer;
a transferrable-pesticide having a vapor pressure of at least about 3 mPa at 25° C. and disposed about said core particle; and
a polyurethane layer having a glass transition temperature (Tg) of at least about 80 ° C. and formed from a reaction mixture having a maximum temperature of no greater than about 25° C., said polyurethane layer disposed about said transferrable-pesticide;
wherein said polyurethane layer inhibits said transferrable-pesticide from transferring to a surface different from said core particle when said encapsulated particle physically contacts the surface.

8. The encapsulated particle as set forth in claim 7 , wherein said polyurethane layer:
i) comprises the reaction product of an isocyanate and a polyol; and/or
ii) is free of catalyst(s).

9. The encapsulated particle as set forth in claim 8 , wherein said polyol comprises the reaction product of i) an alkylene oxide having from 2 to 4 carbon atoms and ii) glycerol.

10. The encapsulated particle as set forth in claim 7 , wherein said transferrable-pesticide comprises a dinitroaniline.

11. The encapsulated particle as set forth in claim 7 , wherein said core particle comprises urea.

12. A method of forming an encapsulated particle comprising a core particle comprising a fertilizer, a transferrable-pesticide having a vapor pressure of at least about 3 mPa at 25° C. and disposed about and in contact with the core particle, and a polyurethane layer having a glass transition temperature (Tg) of at least about 80 ° C. disposed about the transferrable-pesticide, wherein the core particle comprises a fertilizer, and the polyurethane layer comprises the reaction product of an isocyanate and a polyol, said method comprising the steps of:
encapsulating the core particle with the transferrable-pesticide to form an intermediate-particle;
combining the isocyanate and the polyol to form a reaction mixture having a maximum reaction temperature of no greater than about 25° C.; and
encapsulating the intermediate-particle with the reaction mixture to form the polyurethane layer of the encapsulated particle.

13. The method as set forth in claim 12 , wherein the transferrable-pesticide comprises a dinitroaniline or is pendimethalin.

14. The method as set forth in claim 12 , wherein the reaction mixture of the polyurethane layer:
i) is free of catalyst(s); and/or
ii) further comprises a silicone surfactant.

Assignees

• Basf Se

Inventors

• Neff Raymond A
• Gershanovich Alexander
• Wilson Johanne

Classifications

• C05G3/60

  Biocides or preservatives, e.g. disinfectants, pesticides or herbicides; Pest repellants or attractants · CPC title

• C05G5/37 Primary

  layered or coated with a polymer · CPC title

• A01N25/26 Primary

  in coated particulate form · CPC title

• C08G2310/00

  Agricultural use or equipment · CPC title

• C09D175/04

  Polyurethanes · CPC title