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:
Jun. 17, 2008
Filed:
Jun. 28, 2004
Takashi Monoi, Kawasaki, JP;
Hidenobu Torigoe, Kawasaki, JP;
Takashi Monoi, Kawasaki, JP;
Hidenobu Torigoe, Kawasaki, JP;
Japan Polyethylene Corporation, Tokyo, JP;
Abstract
A method for producing an ethylene polymer which comprises continuously polymerizing ethylene alone or copolymerizing ethylene and a C-Cα-olefin by multistage polymerization in a plurality of polymerization reactors connected in series in the presence of a chromium catalyst having at least a part of chromium atoms converted to hexavalent chromium carried on an inorganic oxide carrier by calcination-activating in a non-reducing atmosphere, wherein an organoaluminum compound of the formula (1):(R)Al(OR)(OSiRRR)  (1)(in the above formula, Rand Rmay be the same or different, each represents a C-Calkyl group or a C-Caryl group, R, Rand Rmay be the same or different, each represents a C-Calkyl group or a C-Caryl group, R, ORand OSiRRRrespectively may be the same or different when each has a plurality of kinds, and x, y and z are respectively 0≦x≦3, 0≦y<3, 0≦z<3, and x+y+z=3) is introduced at least one or all of the polymerization reactors.