Patents Assigned to Chisso Corpoation
  • Patent number: 6005034
    Abstract: A propylene-ethylene copolymer composition is obtained which has good moldability and an excellent balance of rigidity, toughness, and impact-strength. The composition has a melt flow rate of 10 to 300 g/10 minutes and is obtained by producing 60 to 95% by weight, based on the weight of whole polymer, of a propylene polymer having a melt flow rate (ASTM D1238) in the range of 100 to 1,000 g/10 minutes and having a ratio (Cf) of integrated values of the propylene polymer dissolved in o-dichlorobenzene at a temperature of lower than 112.degree. C., and a temperature of 112.degree. C. or higher, respectively, of 0.5 or less, by carrying out polymerization of propylene in the presence of a highly stereoregular catalyst and hydrogen in a polymerization step (I), and then producing 5 to 40% by weight, based on the weight of whole polymer, of an ethylene-propylene copolymer by feeding ethylene and propylene to the propylene polymer to react so that the content of ethylene becomes 30 to 80% by weight.
    Type: Grant
    Filed: April 30, 1997
    Date of Patent: December 21, 1999
    Assignees: Chisso Corpoation, Toyota Jidosha Kabushiki Kaisha
    Inventors: Teruaki Hayashida, Shinei Gima, Kouichi Hatada, Osamu Kojima, Ken Shimizu, Hirokazu Nakajima, Takao Nomura, Yoshihiro Kanome, Takeyoshi Nishio