Thermoplastic polyurethane for skin material for interior parts of vehicle, comprises specified amount of isocyanate compounds, ether-containing polyester polyol, and chain extender(s), which are mixed and condensed

摘要

A thermoplastic polyurethane comprising an ether-containing polyester polyol is prepared by mixing and condensing (pbw) isocyanate compounds (15-60), ether-containing polyester polyol (30-70), and chain extender(s) (5-40). The polyester polyol is prepared by mixing multifunctional carboxylic acids (40-80) and polytetramethylene ether glycol (2-100). A thermoplastic polyurethane comprising an ether-containing polyester polyol is prepared by mixing and condensing 15-60 pbw of isocyanate compounds consisting of diphenyl methane diisocyanate, toluene diisocyanate, hemethylene diisocyanate, or dicycloheylmethane diisocyanate; 30-70 pbw of ether-containing polyester polyol; and 5-40 pbw of chain extender(s) consisting of ethylene glycol, diethylene glycol, butane diol or hexene diol, triols such as trimethylol propane, or polytetramethylene ether glycol. The ether-containing polyester polyol is prepared by mixing 40-80 pbw of multifunctional carboxylic acids consisting of adipic acid, sbelic acid, abelic acid, azelic acid, sebacic acid, dodecandioic acid, or trimeric acid; and 20-100 pbw of polytetramethylene ether glycol containing multifunctional alcohol compounds having a hydroxyl value of 561-56.1 mg potassium hydroxide (KOH)/g; and reacting the resulting mixture to give a hydroxyl value of 224.11-11.22 mg KOH/g. The multifunctional alcohol comprises diols that are exemplified as ethylene glycol, butane diol or hexane diol, or triols consisting of trimethylol propane. An independent claim is also included for a method of preparing the above thermoplastic polyurethane by mixing the ether-containing polyester polyol and chain extender at 30-100[deg]C for 1-10 minutes with stirring, adding the isocyanate to the first mixture and mixing the them at 300-1000 rpm for 1-10 minutes to provide a second mixture, ripening the second mixture at 60-140[deg]C for 1-48 hours, pulverizing the resulting product at below 0[deg]C, and extruding the pulverized mixture at 150-300[deg]C.