Polyamidoamine-epihalohydrin resins, method of manufacture, and uses thereof
View Patent ↗A novel process for producing a polyamidoamine-epihalohydrin resin composition comprises (a) reacting a polyamidoamine with epihalohydrin to obtain a reaction mixture comprising a polyamidoamine-epihalohydrin resin; (b) adding a first acid to the reaction mixture obtained in step (a) to obtain an acid treatment composition; (c) adding a base to the acid treatment composition in step (b) to obtain a base treatment composition; and (d) adding a second acid to the base treatment composition in step (c) to obtain a polyamidoamine-epihalohydrin resin composition; wherein the polyamidoamine-epihalohydrin resin composition obtained in step (d) has less than about 700 ppm of dihalopropanol (DHP) and 3-halopropanediol (HPD).
1. A process for producing a polyamidoamine-epihalohydrin resin composition, comprising:
treating a polyamidoamine-epihalohydrin resin mixture containing halogenated epihalohydrin byproducts with formic acid to obtain a formic acid-treated resin mixture;
treating the formic acid-treated resin mixture with a base to obtain a formic acid-base resin mixture; and
adding a quenching acid to the formic acid-base resin mixture to obtain a polyamidoamine-epihalohydrin resin composition having less than 700 ppm of a combined amount of 1,3-dihalopropanol and 3-halopropanediol.
2. The process of claim 1 , wherein the 1,3-dihalopropanol and the 3-halopropanediol are 1,3-dicloropropanol and 3-chloropropanediol, respectively.
3. The process of claim 1 , wherein the polyamidoamine-epihalohydrin resin mixture has a solids content of about 10 wt % to about 50 wt %, based on the total weight of the mixture.
4. The process of claim 1 , wherein the polyamidoamine-epihalohydrin resin mixture is prepared by reacting adipic acid with diethylenetriamine at a molar ratio of adipic acid to diethylenetriamine of less than 1.0:1.0.
5. The process of claim 1 , further comprising treating the polyamidoamine-epihalohydrin resin mixture with a stabilizing acid prior to the treating with formic acid.
6. The process of claim 5 , wherein the stabilizing acid is sulfuric acid.
7. The process of claim 1 , wherein treating the polyamidoamine-epihalohydrin resin mixture comprises adding about 0.05 wt % to about 10.0 wt % of the formic acid, based on the total weight of the polyamidoamine-epihalohydrin resin mixture.
8. The process of claim 1 , wherein the formic acid-treated treated resin mixture has a pH of about 2 to about 8.
9. The process of claim 1 , wherein the formic acid-treated resin mixture has a solids content of about 10 wt % to about 35 wt %, based on the total weight of the formic acid-treated resin mixture.
10. The process of claim 1 , wherein the base comprises diethanolamine.
11. The process of claim 1 , wherein the base comprises sodium hydroxide and diethanolamine.
12. The process of claim 1 , wherein the formic acid-base resin mixture has a pH of about 7 to about 11.
13. The process of claim 1 , wherein the formic acid-base resin mixture has a pH of about 10 to about 11.
14. The process of claim 1 , wherein the polyamidoamine-epihalohydrin resin composition has a pH of about 2 to about 4.
15. The process of claim 1 , wherein the quenching acid is a combination of formic acid and sulfuric acid.
16. The process of claim 1 , wherein the polyamidoamine-epihalohydrin resin composition has less than 500 ppm of the combined amount of the 1,3-dihalopropanol and the 3-halopropanediol.
17. The process of claim 16 , wherein the 1,3-dihalopropanol and the 3-halopropanediol are 1,3-dicloropropanol and 3-chloropropanediol, respectively.
18. The process of claim 1 , further comprising adding a stabilizing compound to the polyamidoamine-epihalohydrin resin composition in an amount of about 1% to about 15% by weight of solids of the polyamidoamine-epihalohydrin resin composition.
19. A process for producing a polyamidoamine-epihalohydrin resin composition, comprising:
treating a polyamidoamine-epihalohydrin resin mixture containing halogenated epichlorohydrin byproducts with formic acid to obtain a formic acid-treated resin mixture;
treating the formic acid-treated resin mixture with an inorganic base and diethanolamine to obtain a formic acid-base resin mixture; and
adding a quenching acid to the formic acid-base resin mixture to obtain a polyamidoamine-epihalohydrin resin composition having less than 500 ppm of a combined amount of 1,3-dihalopropanol and 3-halopropanediol.
20. The process of claim 19 , the formic acid-base resin mixture has a pH of about 10 to about 11.
21. The process of claim 19 , wherein the 1,3-dihalopropanol and the 3-halopropanediol are 1,3-dicloropropanol and 3-chloropropanediol, respectively.
22. The process of claim 1 , wherein the quenching acid is added as a mixture comprising formic acid and sulfuric acid, and wherein the quenching acid has a molar ratio of formic acid to sulfuric acid of about 0.2:1 to about 1.5:1.
23. The process of claim 1 , wherein the formic acid-treated resin mixture has a pH of about 2.5 to about 7.5, the formic acid-base resin mixture has a pH of about 7 to about 11, and the polyamidoamine-epihalohydrin resin composition has a pH of about 2 to about 4.
24. The process of claim 19 , wherein the quenching acid is added as a mixture comprising formic acid and sulfuric acid, and wherein the quenching acid has a molar ratio of formic acid to sulfuric acid of about 0.2:1 to about 1.5:1.
25. The process of claim 19 , wherein the formic acid-treated resin mixture has a pH of about 2.5 to about 7.5, the formic acid-base resin mixture has a pH of about 7 to about 11, and the polyamidoamine-epihalohydrin resin composition has a pH of about 2 to about 4.