Multilayer, stretched heat-sealable polypropylene film combining good surface slip with improved barrier properties

US5447792A · kind A · utility

Assignee

• Wolff Walsrode AG · DE

Inventors

• Rainer Brandt · Walsrode, DE
• Ulrich Reiners · Neuenkirchen, DE
• Anton Krallmann · Bad Fallingbostel, DE
• Eberhard Albinus · Bad Fallingbostel, DE
• Neele Neelen · Einbeck, DE

Key dates

• Filing date: Mar 3, 1994
• Grant date: Sep 5, 1995
• Expiry date: Mar 3, 2014

Classification

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

Abstract

The invention relates to oriented, sealable polypropylene film combining an improved water vapor barrier effect with a considerably reduced coefficient of friction for packaging purposes, characterized in that they are free from polydimethyl siloxane and have the following structure: A B C B A where a) C is the core layer consisting of polypropylene and a hydrocarbon resin, which has a molecular weight of up to about 2000 g/mol and a softening point above 130.degree. C., and 0.05 to 0.5% by weight erucic acid amide, b) the B's are two jacket layers of highly isotactic polypropylene (isotacticity >94%) free from hydrocarbon resin, the ratio between the thickness of the jacket layer and the thickness of the base layer being between 0.01 and 0.1, c) the A's are two surface layers of a heat-sealable polyolefin copolymer or terpolymer, these surface layers containing at least one antiblocking agent, an antistatic agent and, as lubricant, 0.05 to 0.5% by weight erucic acid amide.