Wet strengthened fiber products, wet strengthening resins, and methods for making and using same

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.

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.