| 摘要 |
PURPOSE: To improve the abrasion resistance and water absorption swelling of a foamed extruded article of a thermoplastic elastomer by a method in which the thermoplastic elastomer is mixed with isocyanate prepolymer or isocyanate prepolymer of specified structure having a hydrophilic group in the main chain, and the composition is extruded and expanded. CONSTITUTION: Pellets of thermoplastic elastomer are fed from the first supply port 2, and water is supplied from the second supply port 3 which is formed in a melting-compression zone in which the compound fed is melted completely. Next, isocyanate prepolymer is fed from the third supply port 4, and the product is extruded from a circular die 5, cooled in a cooling water tank 6, and received by a receiving machine 7. The isocyanate prepolymer, a prepolymer with terminal isocyanate groups, is prepared by the polyaddition reaction between diisocyanate and polyester or polyether having terminal hydroxyl groups. Or, a mixture of isocyanate prepolymer having a hydrophilic unit, e.g. oxyethylene unit in the main chain and an amine- or polyol-type composition can be used. |
