Water-based microemulsion formulations

• US 5,317,042 A
• Filed: 09/30/1992
• Issued: 05/31/1994
• Est. Priority Date: 12/11/1989
• Status: Expired due to Term

• Current Assignee: ISP Capital, Inc. (Ashland Global Holdings, Inc.)
• Original Assignee: ISP Investments, Inc. (Ashland Global Holdings, Inc.)
• Inventors: Narayanan, Kolazi S.
• Primary Examiner(s): Waddell, Frederick E.
• Assistant Examiner(s): WEDDINGTON, KEVIN E
• Application Number:
  US07/953,331
• Time in Patent Office: 608 Days
• Field of Search: 514/788, 514/938, 514/937, 514/941, 514/772, 514/772.3, 514/65, 514/572, 71/79, 71/93, 504/116
• US Class Current: 514/772
• CPC Class Codes: A01N 2300/00 Combinations or mixtures of active ingredients covered by classes A01N27/00 - A01N65/48 with other active or formulation relevant ingredients, e.g. specific carrier materials or surfactants, covered by classes A01N25/00 - A01N65/48
• CPC Class Codes: A01N 25/02 containing liquids as carriers, diluents or solvents
• CPC Class Codes: A01N 25/04 Dispersions, emulsions, suspoemulsions, suspension concentrates or gels foams A01N25/16
• CPC Class Codes: A01N 43/36 five-membered rings
• CPC Class Codes: A01N 43/40 six-membered rings
• CPC Class Codes: A01N 43/46 rings with more than six members
• CPC Class Codes: B65H 2557/242 involving a particular data profile or curve

Abstract

Clear, stable, efficacious, aqueous microemulsions of a pyrethroid insecticide, optionally with another agriculturally active ingredient, are provided herein. The aqueous microemulsions are obtained by providing an inert matrix composition containing a defined mixture of nonionic surfactants, optionally including an anionic surfactant, mixing with a pyrethroid to form a microemulsion concentrate, and diluting with water. Preferably, the aqueous microemulsion includes an N-alkyl (C₁ -C₄) pyrrolidone therein as a cosolvent in the microemulsion system.

Claims

1. An inert matrix composition for forming a clear, efficacious aqueous microemulsion upon admixture with a predetermined amount of a pyrethroid insecticide and water, which is stable at or below room temperature for an extended period of time, consisting essentially of a predetermined mixture of nonionic surfactants:

(a) a C₆ -C₁₈ alkylpyrrolidone,

(b) an alkyl phenol ethoxylated alcohol with HLB≧

6; and

(c) an ethylene oxide/propylene oxide/ethylene oxide block copolymer,

in a weight ratio of (a);

(b);

(c) of about 0.5-2;

0.5-2;

3-12.

2. An inert matrix composition according to claim 1 which includes up to 60% by weight thereof of N-methylpyrrolidone.

3. An inert matrix composition according to claim 1 wherein (b) is a nonylphenol ethoxylated alcohol with 9 ethylene oxide groups.

4. An inert matrix composition according to claim 1 which includes an anionic surfactant.

5. An inert matrix composition according to claim 4 in which said anionic surfactant is a nonylphenol ethoxylated phosphate ester with 9 ethylene oxide groups.

6. A two-part microemulsion system for forming a clear, efficacious, aqueous microemulsion of a pyrethroid insecticide by admixture of the respective parts of said system, and water, which is stable at or below room temperature for an extended period of time, consisting essentially of:

(i) as one part, the inert matrix composition of claim 1, and

(ii) as the second part, a powdered pyrethroid insecticide, optionally including a synergist or another active agricultural ingredient, or both.

7. A system according to claim 6 wherein said system includes up to 60% by weight of N-methylpyrrolidone as cosolvent in which said N-methylpyrrolidone is present in either one or both parts of said system.

8. A microemulsion concentrate for forming a clear, efficacious aqueous microemulsion of a pyrethroid insecticide upon dilution with water, which is stable at or below room temperature for an extended period of time, consisting essentially of:

about 5-20% of a C₆ -C₁₈ alkylpyrrolidone,

about 30-72% of an alkyl phenol ethoxylated alcohol with HLB≧

6,

about 5-20% of an ethylene oxide/propylene oxide/ethylene oxide block copolymer, and

about 0.5-20% of a pyrethroid insecticide, by weight of said concentrate.

9. A microemulsion concentrate according to claim 8 which includes about 4-6% of N-methylpyrrolidone.

10. A clear, efficacious, aqueous microemulsion of a pyrethroid insecticide which is stable at or below room temperature for an extended period of time consisting essentially of:

about 0.5-20 parts of the microemulsion concentrate of claim 8, and

about 80-99.5 parts of water.

11. A clear, efficacious, aqueous microemulsion according to claim 10 which includes about 4-60% of N-methylpyrrolidone.