Biaxially oriented polyolefin multi-layer film

US4734317A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

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

Key dates

• Filing date: Mar 5, 1986
• Grant date: Mar 29, 1988
• Expiry date: Mar 5, 2006

Classification

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

Abstract

A polyolefin film having a base layer composed essentially of propylene polymers and having sealing layers present on both sides, composed essentially of sealable olefin polymers. Polydialkylsiloxane is incorporated in a first of the two sealing layers, and this layer is not subjected to corona treatment. The second sealing layer is subjected to corona treatment and has polydialkylsiloxane, not incorporated, but present on its outer surface, the polydialkylsiloxane having been transferred to this layer by contact with the sealing layer in which polyidalkylsiloxane is incorporated. The relative polydialkylsiloxane occupancy on the second layer, which is determined by means of ESCA spectroscopy, is not more than 15. The three-layer polyolefin film is prepared by a coextrusion process. It is particularly suitable for use as a packaging film on high-speed packaging machines.