Process for producing improved random propylene copolymers

US6013742A · kind A · utility

Assignee

• BASF SE

Inventors

• Stephan Huffer · Birkenfeld, DE
• Meinolf Kersting · Neustadt, DE
• Franz Langhauser · Bad Dürkheim, DE
• Rainer A. Werner · Annaberg-Buchholz, DE
• Patrik Müller · Gothenburg, SE
• Jurgen Kerth · Eisenberg (Pfalz), DE

Key dates

• Filing date: Nov 13, 1997
• Grant date: Jan 11, 2000
• Expiry date: Nov 13, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F2410/06
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for preparing random propylene copolymers containing copolymerized C.sub.2 -C.sub.10 -alk-1-enes by polymerization of propylene and C.sub.2 -C.sub.10 -alk-1-enes in the presence of a Ziegler-Natta catalyst system comprising a titanium-containing solid component a) comprising a compound of magnesium, a halogen, silica gel as support and a carboxylic ester as electron donor compound, and also, as cocatalysts, an aluminum compound b) and a further electron donor compound c), where propylene and the C.sub.2 -C.sub.10 -alk-1-enes are polymerized with one another at from 50 to 100.degree. C. at pressures in the range from 15 to 40 bar and mean residence times of from 0.5 to 5 hours and the support used in the titanium-containing solid component is a silica gel which has a mean particle diameter of from 5 to 200 .mu.m, a mean particle diameter of the primary particles of from 1 to 10 .mu.m and voids or channels having a mean diameter of from 1 to 10 .mu.m, which voids or channels have a macroscopic proportion by volume based on the total particle in the range from 5 to 20%.