Propylene copolymer and process for the production thereof

• Main Authors: YASUDA, YOSHITOYO, SAITO, JUN, FUJITA, HIROYUKI, TSUTSUI, MOTOTAKE, USHIODA, TSUTOMU
• Format: Patent
• Language: English
• Published: 11.10.2001
• Edition: 7
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

A propylene copolymer which exhibits high stereoregularity, is remarkably lowered in the non-stereoregular portion content of the copolymer, and has a narrow molecular weight distribution, high melt tension, excellent heat stability, a low MFR and excellent particle properties; and a process for the production thereof with a specific metallocene catalyst, which can be carried out even at a practical polymerization temperature. The process is characterized by copolymerizing propylene with an , -diene by the use of a supported catalyst comprising the following compounds (A), (B), (C) and (D) as the main components at a temperature of 45 DEG C or above: compound (A): a specific metallocene represented by formula: Q(C5H4-mR1m)(C5H4-nR2n)MXY, compound (B): an aluminoxane, compound (C): an organoaluminum compound, and compound (D): a particulate carrier. The propylene copolymer is a highly stereoregular one characterized also in that the content of stereoirregular units formed by the 2,1-addition of propylene monomers based on all the propylene monomers introduced is regulated to be within a specific range.