| abstract |
A moisture curable polyurethane (PUR) hot melt adhesive that, when heated, produces less hazardous isocyanate gas, and is safe and easy to handle by a user. This moisture curable polyurethane hot melt adhesive comprises 100 parts by weight of a urethane prepolymer which is a product obtained from a reaction between an excess amount of diphenylmethane diisocyanate and a mixture of a polyol of crystalline polyester and a non-crystalline polyester polyol and / or a non-crystalline polyether polyol; and 5 to 20 parts by weight of an amino-containing surface-modifying silica gel. Preferably, the surface modification silica gel is a silica gel to which is bonded a residual group of a silane oligomer, which is a hydrolytic product of aminoalkyl (di or tri) alkoxy silane. |