Stabilization of non-aqueous suspensions

• US 5,599,768 A
• Filed: 11/09/1994
• Issued: 02/04/1997
• Est. Priority Date: 09/21/1989
• Status: Expired due to Fees

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Hermansky, Clarence G.
• Primary Examiner(s): CLARDY, S
• Application Number:
  US08/336,602
• Time in Patent Office: 818 Days
• Field of Search: 504/116, 504/234, 504/330, 504/211, 71/DIG. 1, 514/395, 514/63, 514/383, 514/369, 514/772.3, 514/773, 514/777, 514/937, 514/970
• US Class Current: 504/211
• CPC Class Codes: A01N 25/04 Dispersions, emulsions, suspoemulsions, suspension concentrates or gels foams A01N25/16

Abstract

A formulation consisting of an active ingredient (herbicide or pesticide) suspended in an organic medium containing, in addition to usual additives, a polymer and protic solvent and a process for the preparation of such formulation.

Claims

1. A process for stabilizing a suspension, said suspension consisting of in weight percent based on total formulation weight,

0.1-50% of at least one active ingredient;

20-99% organic medium;

0.01-5% of at least one suspending agent wherein the active ingredient is substantially insoluble in the organic medium, and

sufficient emulsifier for suspension of the final product in water,

which process comprises;

adding to the suspension 0.1-15% of at least one of a water-swellable or water-soluble polymer selected from the class consisting of;

polyvinyl ethers, polyvinyl pyrrolidones, polypropylene oxide-polyethylene oxide condensates, polyvinyl acetates, maleic anhydrides, polypropylene glycols, modified polyacrylic acids, polyacrylonitrile block copolymers, polysaccharides, polysaccharide derivatives, proteins, carbohydrates, and mixtures of the foregoing; and

0.5-15% of at least one protic solvent.

2. The process of claim 1 wherein the polymer is a member selected from the class consisting of:

Polyvinyl methyl ether (PVME, M.W. 1-5,000)

Polyvinyl pyrrolidone, (PVP M.W. ˜

25-100,000)

Polypropylene oxide-polyethylene oxide condensates (PPO-PEO, M.W. 1-10,000)

Polyvinyl acetate (PVA, M.W. 5-50,000)

Styrene maleic anhydride (SMA, 1-10,000)

Polypropylene glycol (PPG, 1-10,000)

Modified polyacrylic acid (PAA, 1-500,000)

Xanthan Gum

Algenates

Cellulose Derivatives and mixtures of the foregoing.

3. The process of claim 2 wherein the polymer is a member selected from, the class consisting of:

Polyvinyl methyl ether (PVME, M.W. 2-3,000)

Polyvinyl pyrrolidone (PVP M.W. ˜

40,000)

Polypropylene oxide-polyethylene oxide condensates (PPO-PEO, M.W. 2,000)

Polyproplyene oxide-polyethylene oxide condensates (PPO-PEO, M.W. 5,850)

Polyvinyl acetate (PVA, M.W. 11-31,000)

Styrene maleic anhydride (SMA, 1,000)

Polypropylene glycol (PPG, 4,000)

Modified polyacrylic acid (PAA, 200,000) and mixtures of the foregoing.

4. The process of claim 1 wherein the suspension consists of in weight percent based on total formulation weight, 10-50% active ingredient, 20-60% organic medium and 0.1-2% suspending agent and 0.5-10% polymer and 0.5-15% protic solvent are added to the suspension.

5. The process of claim 4 wherein the organic medium is a member selected from the class consisting of oxygenated and nonoxygenated solvents from the class of petroleum solvents;

aromatic and non-aromatic hydrocarbons;

halogenated aromatic and non-aromatic hydrocarbons;

aromatic and non-aromatic ethers, esters, amides, ketones;

alcohols;

vegetable oils;

paraffin oils; and

mixtures of the foregoing.

6. The process of claim 5 wherein the organic medium is a member selected from the class consisting of xylenes, chlorotoluenes, alkyl benzenes, alkyl napthalenes, aliphatic acetates, soybean oil, corn oil, cottonseed oil, paraffinic solvents and oils, and mixtures of the foregoing.

7. The process of claim 4 wherein the protic solvents are a member selected from the class consisting of water, gycerol, propylene glycol, n-butanol, n-hexanol, sorbitol, dipropylene glycol and mixtures of the foregoing.

8. The process of claim 7 wherein the polymer is water-soluble or water-swellable and is a member selected from the class of synthetic and naturally occurring polymers, biopolymers consisting of:

Polyvinyl Ethers

Polyvinyl Pyrrolidones

Polypropylene oxide-polyethylene oxide condensates

Polyvinyl Acetates

Maleic Anhydrides

Polypropylene Glycols

Modified Polyacrylic Acids

Polyacrylonitrile Block Copolymers

Polysaccharides

Polysaccharide Derivatives

Proteins

Carbohydrates

Xanthan Gum

Algenates

Cellulose Derivatives and mixtures of the foregoing.

9. The process of claim 8 wherein the polymer is a member selected from the class of synthetic, add naturally occurring polymers, biopolymers consisting of:

Polyvinyl methyl ether (PVME, M.W. 1-5,000)

Polyvinyl pyrrolidone (PMP M.W. ˜

25-100,000)

Polypropylene oxide-polyethylene oxide condensates (PPO-PEO, M.W. 1-10,000)

Polyvinyl acetate (PVA, M.W. 5-50,000)

Sytrene maleic anhydride (SMA, 1-10,000)

Polypropylene glycol (PPG, 1-10,000)

Modified polyacrylic acid (PAA, 1-500,000) and mixtures of the foregoing.

10. The process of claim 9 wherein the polymer is a member selected from the class consisting of:

Polyvinyl methyl ether (PVME, M.W. 2-3,000)

Polyvinyl pyrrolidone (PMP M.W. ˜

40,000)

Polypropylene oxide-polyethylene oxide condensates (PPO-PEO, M.W. 2,000)

Polypropylene oxide-polyethylene oxide condensates (PPO-PEO, M.W. 5,850)

Polyvinyl acetate (PVA, M.W. 11-31,000)

Styrene maleic anhydride (SMA, 1,000)

Polypropylene glycol (PPG, 4,000)

Modified polyacrylic acid (PAA, 200,000) and mixtures of the foregoing.

11. The process of claim 10 wherein the protic solvent is propylene glycol.

12. The process of claim 10 wherein the protic solvent is water.

13. The process of claim 4 wherein the active ingredient is a member selected from the class consisting of pesticides, herbicides, fungicides, bactericides, insecticides, insect antifeedants, acaricides, miticides, nematocides, plant growth regulants and mixtures of the foregoing.

14. The process of claim 13 wherein the active ingredient is hexythiazox.

15. The process of claim 13 wherein the active ingredient is a benzimidazole or mixture thereof.

16. The process of claim 15 wherein the active ingredient is carbendazim.

17. The process of claim 13 wherein the active ingredient is a triazine or mixture thereof.

18. The process of claim 17 wherein the active ingredient is atrazine.

19. The process of claim 13 wherein the active ingredient is atrazine with diuron.

20. The process of claim 13 wherein the active ingredient is a sulfonylurea.

21. The process of claim 20 wherein the active ingredient is

N-[[(4,6-dimethoxy-2-pyrimidinyl)amino]-carbonyl]-3-(ethylsulfonyl)-2-pyridine sulfonamide.

22. The process of claim 20 wherein the active ingredient is

methyl 3-[[[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]-carbonyl]amino]-sulfonyl]-2-thiophene-carbonate.

23. The process of claim 20 wherein the active ingredient is

methyl 2-[[[[N-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)-N-methylamino]carbonyl]amino]sulfonyl]benzoate.

24. The process of claim 20 wherein the active ingredient is

methyl 2-[[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]-sulfonyl]methyl]benzoate.

25. The process of claim 20 wherein the active ingredient is

2-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-N,N-dimethyl-3-pyridinecarboxamide.

26. The process of claim 20 wherein the active ingredient is

methyl 2-[[[[[4,6-bis(difluoromethoxy)-2-pyrimidinyl]amino]carbonyl]amino]sulfonyl]benzoate.