| 摘要 |
PURPOSE:To increase the productivity of polyurethane resin by a method wherein the predetermined equivalent amounts of long-chain polyol, di-isocyanate and low-molecular diol are directly charged in an extruder so as to be successively heated up to specified temperatures and mixed in the extruder in order to successively and continuously synthesized urethane and plasticize it and finally extrude it in the form of pellets. CONSTITUTION:From a hopper C, the mixture of the predetermined equivalent amounts of chain caprolactam and 4,4'-diphenylmethane diisocyanate is poured in a double-screw extruder A having vent holes D. Further, 1,4-butanediol is forced at the position apart by seventh pitch from the hopper of the extruder by means of a pouring pump J in the extruder. After that, the resultant mixture is transferred to a plasticizing zone are held at 150 deg.C in a strand die F provided at the outlet of the extruder. By charging the resultant pellets to an injection molder, a sheet having favorable physical properties is obtained. |
