Wet strengthened fiber products, wet strengthening resins, and methods for making and using same
View Patent ↗Wet strengthened fiber products, wet strengthening resins, and methods for making such wet strengthened fiber products and wet strengthening resins. The wet strengthened fiber product can include a fiber web and an at least partially cured wet strengthening resin, which prior to at least partially curing, the wet strengthening resin can include a polyamide-epihalohydrin (PAE) resin and a cationic styrene maleimide (SMI) resin. The PAE resin can include a reaction product of a polyamidoamine and an epihalohydrin and the cationic SMI resin can include a reaction product of a styrene maleic anhydride (SMA) copolymer and an amine. The wet strengthened fiber product can include the wet strengthening resin in an amount of about 0.05 wt % to about 5 wt %, based on a dried weight of the wet strengthened fiber product.
1. A wet strengthening resin, comprising:
a polyamide-epihalohydrin resin comprising a reaction product of a polyamidoamine and an epihalohydrin; and
a cationic styrene maleimide resin comprising a reaction product of a styrene maleic anhydride copolymer and an amine compound, a weight average molecular weight of about 500 to about 200,000, and a styrene to maleimide molar ratio of about 1:1 to about 5:1, wherein the wet strengthening resin comprises about 16.7 wt % to about 83.3 wt % of the cationic styrene maleimide resin, based on a combined weight of the polyamide-epihalohydrin resin and the cationic styrene maleimide resin.
2. The wet strengthening resin of claim 1 , wherein the cationic styrene maleimide resin has the chemical formula:
wherein:
R + is a cationic molecular group;
A − is an anion;
m is an integer of 1 to about 5; and
n is an integer of about 5 to about 800.
3. The wet strengthening resin of claim 2 , wherein the cationic molecular group is a cationic ammonium group, wherein the anion is a carboxylate, and the carboxylate is an acetate anion, a citrate anion, an oxalate anion, a lactate anion, a formate anion, or a mixture thereof.
4. The wet strengthening resin of claim 3 , wherein m is equal to 1 and n is an integer of about 5 to about 100.
5. The wet strengthening resin of claim 3 , wherein m is equal to 3 and n is an integer of about 50 to about 300.
6. The wet strengthening resin of claim 1 , wherein the cationic styrene maleimide resin has the chemical formula:
wherein:
R 1 is a substituted or unsubstituted organic diyl group;
R 2 , R 3 , and R 4 are each independently selected from a hydrogen or a substituted or unsubstituted linear, branched, cyclic, heterocyclic, or aromatic hydrocarbyl group;
A − is an anion;
m is an integer of 1 to about 5; and
n is an integer of about 5 to about 800.
7. The wet strengthening resin of claim 6 , wherein R 1 is selected from the group consisting of: methanediyl, ethanediyl, propanediyl, butanediyl, pentanediyl, and a mixture thereof, wherein R 2 , R 3 , and R 4 are each independently selected from the group consisting of: hydrogen, methyl, ethyl, propyl, butyl, and pentyl.
8. The wet strengthening resin of claim 1 , wherein the cationic styrene maleimide resin has the chemical formula:
wherein:
A − is an anion; and
n 1 , n 2 , and n 3 are each independently of about 5 to about 800.
9. The wet strengthening resin of claim 8 , wherein the anion is a carboxylate, wherein n 1 is about 5 to about 100, n 2 is about 20 to about 200, and n 3 is about 50 to about 300.
10. The wet strengthening resin of claim 1 , wherein the cationic styrene maleimide resin has the chemical formula:
wherein n 1 is about 5 to about 100, n 2 is about 20 to about 200, and n 3 is about 50 to about 300.
11. The wet strengthening resin of claim 1 , wherein the cationic styrene maleimide resin comprises a copolymer of styrene and dimethylaminopropylamine maleimide acetate.
12. The wet strengthening resin of claim 1 , wherein the polyamide-epihalohydrin resin has a weight average molecular weight of about 20,000 to about 3,000,000, an azetidinium ion ratio of about 0.55 to about 0.80, and a charge density of about 1.5 mEq/g to about 3.0 mEq/g of solids.
13. A process for making a wet strengthening resin, comprising:
combining a polyamide-epihalohydrin resin and a cationic styrene maleimide resin to produce a wet strengthening resin, wherein:
the polyamide-epihalohydrin resin comprises a reaction product of a polyamidoamine and an epihalohydrin,
the cationic styrene maleimide resin comprises a reaction product of a styrene maleic anhydride copolymer and an amine compound, a weight average molecular weight of about 500 to about 200,000, and a styrene to maleimide molar ratio of about 1:1 to about 5:1, and
the wet strengthening resin comprises about 16.7 wt % to about 83.3 wt % of the cationic styrene maleimide resin, based on the combined weight of the polyamide-epihalohydrin resin and the cationic styrene maleimide resin.
14. The process of claim 13 , wherein the polyamide-epihalohydrin resin has a weight average molecular weight of about 20,000 to about 3,000,000, an azetidinium ion ratio of about 0.55 to about 0.80, and a charge density of about 1.5 mEq/g to about 3.0 mEq/g of solids.
15. The process of claim 13 , wherein the cationic styrene maleimide resin comprises copolymers of styrene and dimethylaminopropylamine maleimide acetate.
16. The process of claim 13 , wherein the polyamide-epihalohydrin resin has a weight average molecular weight of about 20,000 to about 3,000,000, an azetidinium ion ratio of about 0.55 to about 0.80, and a charge density of about 1.5 mEq/g to about 3.0 mEq/g of solids, and wherein the cationic styrene maleimide resin comprises a copolymer of styrene and dimethylaminopropylamine maleimide acetate.
17. A fiber mixture, comprising:
a plurality of fibers; and
a wet strengthening resin, comprising:
a polyamide-epihalohydrin resin comprising a reaction product of a polyamidoamine and an epihalohydrin; and
a cationic styrene maleimide resin comprising a reaction product of a styrene maleic anhydride copolymer and an amine compound, a weight average molecular weight of about 500 to about 200,000, and a styrene to maleimide molar ratio of about 1:1 to about 5:1, wherein the wet strengthening resin comprises about 16.7 wt % to about 83.3 wt % of the cationic styrene maleimide resin, based on a combined weight of the polyamide-epihalohydrin resin and the cationic styrene maleimide resin.
18. The fiber mixture of claim 17 , wherein the plurality of fibers comprises cellulosic fibers.
19. The fiber mixture of claim 18 , wherein the polyamide-epihalohydrin resin has a weight average molecular weight of about 20,000 to about 3,000,000, an azetidinium ion ratio of about 0.55 to about 0.80, and a charge density of about 1.5 mEq/g to about 3.0 mEq/g of solids.
20. The fiber mixture of claim 19 , wherein the cationic styrene maleimide resin comprises copolymers of styrene and dimethylaminopropylamine maleimide acetate.