Aqueous suspension agent for water insoluble compounds
View Patent ↗This invention relates to an improved aqueous suspension concentrate for water insoluble chemicals comprising a mixture of an anionic suspension agent and a homo- and/or a co-polymer of a heterocyclic vinyl lactam combined in a mole ratio of between about 0.1:1 and about 10:1.
1. An aqueous suspension concentrate containing, by weight of the total aqueous concentrate, of (a) between about 20 and about 90 wt. % of an active hydrophobic material; (b) between about 0.1 and about 15 wt. % of a polymeric anionic dispersing agent which consists of a mixture of the sodium salt of an alkyl vinyl ether/maleic acid half ester copolymer or an alpha-olefin/maleic acid copolymer and a lignosulfonate, a lignosulfonate metal salt or a sulfonated naphthalene/formaldehyde condensate, and (c) between about 0.1 and about 10 wt. % of a N-vinyl lactam polymer selected from the group consisting of homo- and co-polymers of N-vinyl pyrrolidone and N-vinyl caprolactam and mixtures thereof.
2. The aqueous suspension concentrate of claim 1 wherein said vinyl lactam polymer has a weight average molecular weight of from about 5,000 to about 100,000.
3. The aqueous suspension concentrate of claim 2 wherein said vinyl lactam polymer is a copolymer of N-vinyl pyrrolidone, dimethylaminoethylmethacrylate and N-vinyl caprolactam.
4. The aqueous suspension concentrate of claim 1 wherein said anionic dispersing agent contains a sulfonated naphthalene formaldehyde condensate.
5. The aqueous suspension concentrate of claim 1 wherein said anionic dispersing agent is selected from the group consisting of a lignosulfonate and a metal salt thereof.
6. The aqueous suspension concentrate of claim 1 containing between about 0.5 and about 10 wt. % anionic dispersing agent and between about 0.3 and about 5 wt. % lactam polymer.
7. The aqueous suspension concentrate of claim 1 wherein the mole ratio of anionic dispersant to lactam polymer is between about 0.1:1 and about 3:1.
8. The aqueous suspension concentrate of claim 1 optionally contains up to 10 wt. % of a excipient selected from the group of an anti-freezing agent, a defoaming agent, a thickening agent and mixtures thereof.
9. The aqueous suspension concentrate of claim 1 wherein said active hydrophobic material is a hydrophobic agricultural chemical or a mixture of said chemicals.
10. A formulation containing between about 0.1 and about 5 wt. % of the concentrate of claim 1 or 9 and water.
11. The aqueous suspension of claim 1 wherein said active hydrophobic material is selected from the group consisting of a nematocide, fungicide, insecticide, herbicide, mulliscide, fertilizer, plant nutrient, plant growth accelerant or regulator and mixtures thereof.
12. The aqueous suspension of claim 11 wherein said active hydrophobic material is chlorothalonil.
13. The aqueous suspension of claim 2 wherein the dispersing agent contains a sulfonated naphthalene/formaldehyde condensate, the N-vinyl lactam polymer is poly(N-vinyl pyrrolidone) and the active material is chlorothalonil.