Moisture curing polyurethane hot melt adhesive (HUMIDITY-SETTING POLYURETHANE HOT-MELT-TYPE GLUE)

摘要

The heat-sealable adhesive according to the present invention comprises (A) at least 10% by weight, based on the total heat-meltable adhesive, of a) at least one polyisocyanate, more particularly toluene diisocyanate and / or MDI, b) Polyalkylene glycols, more particularly polypropylene glycols, c) at least one polyester glycol, preferably at least two polyester glycols having different glass transition temperatures, and d) at least one chain extender At least one polyurethane prepolymer; and (B) optionally, e) a resin, more particularly a hydrocarbon resin, and f) a stabilizer, more particularly an additive such as toluene isocyanate.;The heat-meltable adhesive preferably has a melt viscosity of 4 to 100 Pa s at 170C. The PU prepolymer has only one Tg in the DSC curve. Heat meltable adhesives are characterized by high creep resistance and high initial and final strength. Thus, it is mainly used in the oral application industry, more particularly in pre-crosslinking steps operated by steam or in adhesive application machines designed to work in a shoe manufacturing line that does not contain drying tunnels. The hot melt adhesive is preferably produced by a single-step process. Adhesives are particularly suitable for fibrous materials such as leather and fabrics.