Heat sealing film

US5763074A · kind A · utility

Assignee

• BASF Magnetics GmbH · DE

Inventors

• Albert Kohl · Laumersheim, DE
• Karl-Heinz Romer · Bischofswerda, DE
• Werner Latzel · Oberkirch, DE
• Peter Heilmann · Bad Dürkheim, DE
• Michael Hitzfeld · Karlsruhe, DE

Key dates

• Filing date: Aug 13, 1996
• Grant date: Jun 9, 1998
• Expiry date: Aug 13, 2016

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/2848
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

The heat sealing film and a magnetic transfer strip contain an adhesive layer comprising thermoplastic, immiscible binder components. One component is spherical, amorphous and embedded in finely distributed form in a homogeneous layer of the other, highly crystalline components in such a way that the spherical component protrudes hemispherically from the layer. The spherical binder is a glassy solid up to at least 60.degree. C. and above 80.degree. C. is plastically deformable. The hemispheres protruding from the adhesive layer produce a uniform, fine roughness of the surface. Both heat sealing film and magnetic transfer strip are nonblocking up to at least 60.degree. C. and heat-sealable at temperatures greater than 80.degree. C. The adhesive layer imparts to a magnetic recording medium a uniform thickness of the adhesive joint and a permanent, temperature-resistant adhesive force.