Patent ID: 11926739
Assignee: MCPU POLYMER ENGINEERING LLC
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C | IPC C

Claim 10:
11. A process comprising:
(a) heating a lignin source with a urea nitrogen source and a starved concentration of formaldehyde in the presence of an acidic or basic catalyst at a mass ratio of lignin source to nitrogen source within the range of 1:1 to 1:5 and at a molar ratio of nitrogen source to C1-C5 aldehyde within the range of 3.5:1 to 1:1 to give a reaction mixture comprising a Mannich condensation product;
(b) neutralizing the reaction mixture from step (a) to give a neutralized reaction mixture; and
(c) isolating a modified lignin product from the neutralized reaction mixture
wherein the mass ratio of lignin source to urea to formaldehyde is about 1.0 to about 1.2 to about 0.56.