Use of a specific propene polymer for the production of films

• Main Authors: DREYER,WILHELM,DR, GRUBER,WOLFGANG,DR, HUBER,KARL, SCHOENE,WERNER,DR, KUCHNER,KARL,DR, ALEXANDER,WERNER,RAINER
• Format: Patent
• Language: English; German
• Published: 13.04.1989
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; GENERAL PROCESSES OF COMPOUNDING; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; WORKING-UP

The invention relates to the production of films from propene polymers, characterised in that propene polymers are employed which are obtained by continuous preparation of random copolymers of propene by polymerization of a monomer mixture by means of a Ziegel-Natta catalyst system in the gas phase in a central stirred bed of finely divided polymer with dissipation of the heat of polymerization by evaporative cooling, where the monomer mixture is constantly introduced into the polymerization zone and the polymer is constantly discharged from the polymerization zone, with the provisos that (a) the pressure and temperature in the polymerization zone are kept in a range which corresponds to the gaseous state of the monomer mixture, (b) gaseous, unconsumed monomer mixture is discharged from the polymerization zone and is re-introduced into the polymerization zone in liquid form, (c) the temperature in the polymerization zone is regulated by means of the amount of liquid monomer mixture introduced per time unit, and (d) the monomers consumed by polymerization are replaced, with the particular feature that - using a monomer mixture comprising principally propene, a little ethylene and very little hydrogen - the residence time of the monomer mixture in the polymerization zone is kept very short.