Patent ID: 8445563

Claim:
An aqueous bonding resin having 35-65% solid content, the aqueous bonding resin being a mixture of the product of a reaction among phenol and formaldehyde, a group 1 alkaline metal hydroxide, a kraft liquor degraded lignin polymer and urea, the kraft lignin being mostly free of sulfonic acid groups, the phenol and formaldehyde being 40 to 85% of the weight of the solids provided to the reaction, the mole ratio of formaldehyde to phenol being 1.5-3.5:1, the group 1 alkaline metal hydroxide being 5 to 20% of the weight of the solids provided to the reaction, the kraft liquor degraded lignin polymer being 5 to 20% of the weight of the solids provided to the reaction, the urea being 5 to 35% of the weight of the solids provided to the reaction, the pH of the aqueous bonding resin being 8 to 13, the viscosity of the aqueous bonding resin being 50 to 1000 centipoises.