Claims
- 1. A process of preparing a concentrate which is useful as a thickener for aqueous compositions comprising the steps of:
- A) preparing a solution of an associative thickener compound in an organic solvent capable of forming a low boiling azeotrope with water, said solution being essentially free of water, at a temperature above the boiling point of said low boiling azeotrope,
- B) adding water to said solution while distilling an azeotrope of water and said organic solvent, and,
- C) maintaining the addition of water at a rate sufficient to replace said azeotrope with water, but insufficient to cause a second phase to form in the resulting mixture of said solution and said water.
- 2. The process of claim 1 wherein said organic solvent is selected from the group consisting of hydrocarbon solvents and oxygenated hydrocarbon solvents.
- 3. The process of claim 1 wherein said organic solvent is selected from the group consisting of C.sub.6 -C.sub.9 alkanes and benzene and C.sub.1 -C.sub.4 alkyl-substituted benzenes.
- 4. The process of claim 1 wherein said organic solvent is toluene.
- 5. The process of claim 1 wherein said water is added to the solution, at least initially at a rate of from about 0.1 to about 1.0 parts per one hundred parts of reaction product solution per minute.
- 6. The process of claim 1 wherein said water is added to the solution, at least initially at a rate of from about 0.2 to about 0.5 parts per one hundred parts of reaction product solution per minute.
- 7. The process claimed in claim 1 wherein there is essentially no reflux of azeotrope to return distilled water to the mixture.
- 8. The process of claim 1 wherein the temperature of the reaction mixture falls to about the boiling point of the azeotrope after the beginning of addition of said water.
- 9. The process of claim 8 wherein the rate of water addition is increased after said temperature falls to the boiling point of said azeotrope and begins to rise therefrom.
- 10. The process of claim 9 wherein said increased rate is between about 0.5 parts and 1.5 parts per hundred parts of reaction product solution per minute.
- 11. The process of claim 9 wherein said increased rate is between about 0.75 to about 1.25 parts.
- 12. The process of claim 1 wherein the level of organic solvent in said mixture is reduced to less than about 0.5% by weight.
- 13. The process of claim 1 wherein the level of organic solvent in said mixture is reduced to less than about 0.05% by weight.
- 14. The process of claim I wherein the solids content of the product of said process is from about 20% by weight to about 70% by weight.
- 15. The process of claim 1 wherein the solids content of the product of said process is from about 25% by weight to about 35% by weight.
- 16. The process of claim 1 wherein the viscosity of the product of said process is less than about 15,000 cps.
- 17. The process of claim 1 wherein said solution of an associative thickener compound in an organic solvent capable of forming a low boiling azeotrope with water is about 10% to about 80% by weight of said associative thickener.
- 18. The process of claim 1 wherein said solution of an associative thickener compound in an organic solvent capable of forming a low boiling azeotrope with water is about 20% to about 60% by weight of said associative thickener.
- 19. The process of claim 16 wherein said viscosity from about 2,500 cps to about 7,500 cps.
- 20. The process of claim 16 wherein said viscosity is from about 4,000 cps to about 6,000 cps.
BENEFIT OF EARLIER FILING DATE UNDER 37 CFR 1.78(A)(4)
This is a continuation application of Ser. No. 08/901,579, filed Jul. 28, 1997.
This application claims the benefit of earlier filed and copending provisional application Ser. No. 60/024,101 filed on Aug. 27, 1996.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
5723538 |
Fischer |
Mar 1998 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
901579 |
Jul 1997 |
|