Adhesive composition and heat-fusible member using same

An adhesive composition formed from components consisting essentially of:

• (a) an organic solvent;
• (b) at least one polyolefin (A) that has an acidic group and/or an acid anhydride group and is soluble in the organic solvent, wherein the polyolefin (A) has a weight average molecular weight of 15,000 to 200,000,
• (c) diisocyanate compounds consisting of:
• (B) a diisocyanate compound selected from the group consisting of hexamethylene diisocyanate, pentamethylene diisocyanate, tetramethylene diisocyanate and a derivative thereof, and
• (C) a diisocyanate compound selected from the group consisting of isophorone diisocyanate, norbornane diisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate), dodecane diisocyanate, 1,3-bis(isocyanate methyl)cyclohexane, and a derivative thereof,
• wherein when forming the adhesive composition
• the total amount of the isocyanate compounds is the combined amount of (B) and (C),
• (B) constitutes 20 to 50 wt. % of the total amount of (B) and (C),
• (C) constitutes 50 to 80 wt. % of the total amount of (B) and (C), and
• an equivalent ratio (NCO/COOH) of isocyanate groups in (B) and (C) to carboxylic acid groups in the at least one polyolefin (A) is 0.01 to 9.0;
• and
• (d) optionally at least one component (D) selected from the group consisting of a curing catalyst, a styrenic thermoplastic elastomer, a tackifier, an antioxidant, a hindered amine-based light stabilizer, an ultraviolet absorber, an antistatic agent, a flame retardant, a colorant, a dispersant, an adhesion-imparting agent, an antifoaming agent, a leveling agent, a plasticizer, a lubricant, and a filler.