| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for producing a melt-processable polyurethane with improved processing characteristics, particularly, improved homogeneity. SOLUTION: The process for producing a melt-processable polyurethane comprises a step A of mixing, with a high shearing energy, one or more straight-chain hydroxyl terminal polyols having a weight average molecular weight between approximately 500 and approximately 5,000 with an organic diisocyanate, a step B of forming an OH-terminal prepolymer at a temperature of approximately 80°C or higher, a step C of mixing the OH prepolymer with a chain extender, and a step D of forming a thermoplastic polyurethane through the reaction of the mixture produced in step C with an amount of a component organic diisocyanate so that the equivalent ratio of an NCO group to an group reactive with an NCO group ranges from 0.9:1 to 1.1:1, when all components are taken into consideration, wherein steps A to D are performed optionally with the addition of a 0 to approximately 20% by weight (% by weight is based on the total amount of TPU) of an auxiliary substance and an additive in the presence of a catalyst. COPYRIGHT: (C)2007,JPO&INPIT |
