| abstract |
An object of the present invention is to provide a moisture-curable polyurethane hot melt adhesive (PUR) which is safe for the operator and easy to handle, with less generation of isocyanate gas which is a harmful gas at the time of heating. SOLUTION: With respect to 100 parts by weight of a urethane prepolymer which is a reaction product of a mixture containing a crystalline polyester polyol, an amorphous polyester polyol and / or an amorphous polyether polyol, and an excess of diphenylmethane diisocyanate, 5 to 20 parts by weight of surface-modified silica gel containing an amino group is added. As such a surface-modified silica gel, a silica gel to which a residue of a silane oligomer which is a hydrolysis product of an aminoalkyl (di or tri) alkoxysilane is bonded is preferable. 【Selection chart】 None |