Patents Assigned to Polyurethane Chemical Co., Ltd.
  • Microcellular polyurethane elastomer
    Patent number: 5698608
    Abstract: A microcellular polyurethane elastomer obtained by mixing an NCO-terminated prepolymer, an OH-terminated prepolymer and a foaming component with stirring to cause foaming and curing is disclosed, in which the NCO-terminated prepolymer is (A) a prepolymer obtained by reacting a polyester polyol (a) having a number average molecular weight of 1,000 to 3,000 and diphenylmethane-4,4'-diisocyanate (MDI) or (B) a partially crosslinked prepolymer obtained by further reacting the reaction product of polyester polyol (a) and MDI with a low-molecular weight polyol, the OH-terminated prepolymer is (A) a prepolymer obtained by reacting polyester polyol (a) with a polyisocyanate or (B) a prepolymer obtained by reacting polyester polyol (b) and/or a polyether polyol both having a number average molecular weight of 500 to 3,000 with a polyisocyanate, and the foaming component contains water as a main blowing agent, which elastomer exhibits improved resistance to fatigue failure and permanent set in a fatigue test while reta
    Type: Grant
    Filed: September 24, 1996
    Date of Patent: December 16, 1997
    Assignee: Polyurethane Chemical Co., Ltd.
    Inventor: Tohoru Nagashima
  • Microcellular polyurethane elastomer and process for producing the same
    Patent number: 5585413
    Abstract: A microcellular polyurethane elastomer obtained by mixing an NCO-terminated prepolymer, an OH-terminated prepolymer and a foaming component with stirring to cause foaming and curing is disclosed, in which the NCO-terminated prepolymer is (A) a prepolymer obtained by reacting a polyester polyol (a) having a number average molecular weight of 1,000 to 3,000 and diphenylmethane-4,4'-diisocyanate (MDI) or (B) a partially crosslinked prepolymer obtained by further reacting the reaction product of polyester polyol (a) and MDI with a low-molecular weight polyol, the OH-terminated prepolymer is (A) a prepolymer obtained by reacting polyester polyol (a) with a polyisocyanate or (B) a prepolymer obtained by reacting polyester polyol (b) and/or a polyether polyol both having a number average molecular weight of 500 to 3,000 with a polyisocyanate, and the foaming component contains water as a main blowing agent, which elastomer exhibits improved resistance to fatigue failure and permanent set in a fatigue test while reta
    Type: Grant
    Filed: March 15, 1995
    Date of Patent: December 17, 1996
    Assignee: Polyurethane Chemical Co., Ltd.
    Inventor: Tohoru Nagashima