Polyolefin film having improved mechanical properties

US4698261A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Lothar Bothe · Mainz, DE
• Guenther Crass · Taunusstein, DE

Key dates

• Filing date: Oct 21, 1985
• Grant date: Oct 6, 1987
• Expiry date: Oct 21, 2005

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31913
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

An opaque polyolefin film having a three-layer support film and transparent or clear polyolefin covering layers which cover the two surfaces of the support film. In the support film, either the inner layer or the two intermediate layers arranged between the inner layer and the covering layers are composed of a filler-free polyolefin which is modified with a natural or synthetic resin having a softening point ranging from 70.degree. C. to 180.degree. C. The respective non-modified polyolefin layer or layers of the support film have a filler and exhibit a vacuole structure which produces a relatively low density film of less than 0.9 g/cm.sup.3. The production of the opaque polyolefin film comprising five layers is carried out by coextrusion and biaxial stretching, followed by heat setting the coextruded film. The film is advantageously used for packaging purposes.