The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 19, 1999
Filed:
Mar. 11, 1997
Takashi Ueda, Waki-cho, JP;
Mikio Hashimoto, Waki-cho, JP;
Masaaki Kawasaki, Waki-cho, JP;
Daisuke Fukuoka, Waki-cho, JP;
Junichi Imuta, Waki-cho, JP;
Mitsui Chemicals, Inc., Tokyo, JP;
Abstract
A process for preparing a propylene polymer composition having excellent rigidity, heat resistance and impact resistance, the process comprising conducting multistage polymerization including a step (a) for preparing a propylene (co)polymer (a), a step (b) for preparing a propylene-olefin copolymer (b) and a step (c) for preparing an ethylene-olefin copolymer (c) in the presence of (A) a transition metal compound and (B) a compound activating the transition metal compound (A), in which the steps (a), (b) and (c) may be carried out in any order, each of the second and subsequent stage polymerizations is carried out in the presence of a polymer or polymers obtained by the preceding stage or stages, respectively, and the resulting propylene polymer composition contains the propylene (co)polymer (a) in an amount of 20 to 90% by weight, the propylene-olefin copolymer (b) in an amount of 5 to 75% by weight and the ethylene-olefin copolymer (c) in an amount of 5 to 75% by weight, and has MFR, as measured at 230.degree. C. under a load of 2.16 kg, of 0.01 to 500 g/10 min.