Process for producing polypropylene or propylene random copolymers

• Main Authors: OKAYAMA, CHIKASHI, KIMURA, MASAMI, NAKASHIMA, TAKANORI
• Format: Patent
• Language: English
• Published: 21.02.2004
• Edition: 7
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS; THEIR PREPARATION OR CHEMICAL WORKING-UP

The invention provides a process for producing polypropylene and/or random copolymers of propylene type using a stereoregular catalyst which comprises a titanium-containing solid catalyst component (A), an organoaluminum compound (B) and if required an organosilicon compound (C), wherein [I] before carrying out homopolymerization of propylene or random copolymerization of propylene with an alpha-olefin other than propylene, the above component (A), an organoaluminum compound (B') and if required an organosilicon compound (C') are used, and a small amount of propylene or ethylene and/or an alpha-olefin of 4 to 20 carbon atoms for pre-activation treatment is supplied to the above component (A), and [II] a catalyst which is prepared by adding an organosilicon compound (C"") to the pre-activated stereoregular catalyst in a molar ratio of 0.1 to 50 as Si/Ti, is used to produce polypropylene (propylene homopolymer) or propylene random copolymers (propylene-alpha-olefin random copolymers) with lesser formation of lump and string-like irregular shape polymers.