Lignin-based polyurethane and process for producing the same

摘要

Provided is a polyurethane which is inexpensive and excellent in physical properties and which contains a lignin sulfonic acid component incorporated into the molecular chain of the polyurethane. The polyurethane is obtainable by polycondensation of a polyol solution containing dissolved therein lignin sulfonic acid or a partially neutralized salt thereof with a polyisocyanate, wherein the content of said lignin sulfonic acid is 1-40% based on a total weight of said polyurethane.