Patent ID: 7951868

Claim:
An overcoat ink for overcoating flexible circuits comprising a carboxyl group-containing polyurethane produced by reacting: (A) a polyisocyanate compound; (B) a polycarbonate diol having: (i) a number-average molecular weight of 500 to 50,000; (ii) an alkylene group of 8 to 18 carbon atoms in its structure; and (iii) hydroxyl groups at both ends; (C) a carboxyl group-containing dihydroxy compound; (D) an optional monohydroxy compound; and (E) an optional monoisocyanate compound; and an organic solvent, wherein the polyisocyanate compound (A) contains at least 10 mol % relative to the total (100 mol %) thereof of an aromatic and/or an alicyclic compound of 6 to 30 carbon atoms except the carbon atom in the isocyanate group (NCO group).