Strengthening resins for paper products

A resin composition, comprising:

• about 10 wt % to about 70 wt % of a polyamide-epihalohydrin resin comprising a reaction product of a polyamidoamine and an epihalohydrin;
• about 10 wt % to about 70 wt % of a cationic styrene maleimide resin comprising a reaction product of a styrene maleic anhydride copolymer and an amine compound and having a styrene to maleimide molar ratio of about 1:1 to about 5:1;
• and
• about 10 wt % to about 70 wt % of a urea-formaldehyde resin having a formaldehyde to urea molar ratio of about 0.5:1 to about 1.2:1, wherein all weight percent values are based on a combined solids weight of the polyamide-epihalohydrin resin, the cationic styrene maleimide resin, and the urea-formaldehyde resin.

A fiber product, comprising:

• a fiber web;
• and
• an at least partially cured resin composition, wherein, prior to curing, the resin composition comprises:
• a polyamide-epihalohydrin resin comprising a reaction product of a polyamidoamine and an epihalohydrin;
• a cationic styrene maleimide resin comprising a reaction product of a styrene maleic anhydride copolymer and an amine compound;
• and
• a urea-formaldehyde resin.