URETHANE RESIN COMPOSITION, STEEL SHEET SURFACE TREATMENT AGENT, AND STEEL SHEET HAVING COATING FILM OF SAME

摘要

Provided is a urethane resin composition which has excellent blend stability and is capable of forming a coating film that has excellent corrosion resistance, chemical resistance and adhesion to a substrate. The present invention uses a urethane resin composition which contains a urethane resin (A) that is a reaction product of a polyol (a1) that contains an aromatic polyester polyol (a1-1) and a polyol (a1-2) having an anionic group and a polyisocyanate (a2) and an aqueous medium (B), and which is characterized in that: the aromatic ring concentration in the aromatic polyester polyol (a1-1) is 2.5-5 mol/kg; the polyisocyanate (a2) contains an aliphatic polyisocyanate and/or a polyisocyanate having an alicyclic structure; and the acid value of the urethane resin (A) is within the range of 10-25 mgKOH/g.