Certains contenus de cette application ne sont pas disponibles pour le moment.
Si cette situation persiste, veuillez nous contacter àObservations et contact
1. (WO2017003805) PROCÉDÉS DE PRODUCTION DE COPOLYMÈRES D'ACRYLAMIDE ET D'ACIDE ACRYLIQUE
Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

CLAIMS:

1. A composition comprising a water- in-oil latex, the water- in-oil latex comprising a water phase and an oil phase, the water phase comprising water, acrylamide, and acrylic acid and having a pH of about 3 to 5; wherein the latex further comprises a surfactant mixture consisting essentially of nonionic surfactants and comprising a block copolymer.

2. The composition of claim 1 wherein the water phase consists essentially of water, acrylamide, and acrylic acid, wherein the pH of the water phase is about 3 to 5.

3. The composition of claims 1 or 2 wherein the ratio of acrylamide to acrylic acid is about 60:40 to 99:1.

4. The composition of any of claims 1-3 wherein the block copolymer is a triblock copolymer comprising at least one block consisting essentially of ethylene glycol repeat units and having an HLB of about 4 to 6.

5. The composition of claim 4 wherein the triblock copolymer further comprises at least one block consisting essentially of hydroxyacid repeat units.

6. The composition of claim 5 wherein the hydroxyacid is 12-hydroxystearic acid.

7. The composition of any of claims 1-6 wherein the pH is about 3.5 to 4.0.

8. A method of making a water-in-oil copolymer latex, the method comprising

a. combining water and monomers to form a water phase, the monomers comprising acrylamide and acrylic acid;

b. adjusting the pH of the water phase to between about 3 and 5; c. combining a hydrocarbon solvent with a surfactant mixture to form an oil phase, the surfactant mixture consisting essentially of nonionic surfactants and comprising a block copolymer;

d. contacting the water phase and the oil phase to form a water-in-oil latex;

e. polymerizing the monomers to form a copolymer; and f. neutralizing the water phase.

9. The method of claim 8 further comprising diluting the latex with a water source after neutralizing, wherein the copolymer concentration after diluting is about 0.01 wt% to 1.00 wt%.

10. The method of claim 9 wherein the water source comprises water and a salt of Ca2+, Mg2+, Cr2+, Cr3+, Zn2+, or Al3+.

11. The method of claim 10 wherein the salt is aluminum citrate or chromium acetate.

12. The method of any of claims 8-11 wherein the neutralizing comprises contacting the composition with a neutralizing solution, the neutralizing solution comprising sodium hydroxide and an alkanolamide surfactant.

13. The method of claim 12 wherein the alkanolamide surfactant is N,N-diethanololeamide.

14. A water-in-oil copolymer latex formed using the method of any of claims

8-13.

15. Use of the composition of any of claims 1-7 to form a water-in-oil copolymer latex.