THERMOPLASTIC POLYURETHANE HAVING CROSS-LINKING SITE, AND CROSS-LINKING FOAMING METHOD USING SAME

摘要

The present invention relates to a thermoplastic polyurethane composition imparted with crosslinking sites, which comprise a thermoplastic polyurethane containing crosslinking sites incorporated into the molecule of a polyol and/or a chain extender. The thermoplastic polyurethane composition has an easy-to-process viscosity at a processing temperature of about 130°C or below in a low-temperature foaming process that is performed using an existing EVA crosslinking/foaming system. Thus, the thermoplastic polyurethane composition may be easily mixed with a crosslinking agent, a foaming agent and various additives, and when it is press-molded or injection-molded to provide a crosslinked foam, foam cells are easily formed by the crosslinking sites incorporated into the molecule of the polyol and/or the chain extender. In addition, a foam produced using the thermoplastic polyurethane composition has excellent mechanical properties and also has varying specific gravities depending on the amount of the foaming agent used.