Transparent, thermoformable, biaxially oriented polyester film, process for production thereof and use thereof

US11041056B2 · kind B2 · utility

Assignee

• Mitsubishi Polyester Film GmbH · US

Inventors

• Herbert Peiffer · Mainz, DE
• Martin Jesberger · Mainz, DE
• Stefan Bartsch · Wiesbaden, DE
• Bodo Kuhmann · Runkel, DE
• Viktor FISCHER · Oftersheim, DE
• Matthias Konrad · Kriftel, DE

Key dates

• Filing date: Jun 19, 2019
• Grant date: Jun 22, 2021
• Expiry date: Jun 19, 2039

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08K2201/019
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

The present invention relates to a transparent, biaxially oriented, thermoformable polyester film including at least 85% by weight of a copolyester whose dicarboxylic acid components derive to an extent of 85 to 94 mol % from terephthalic acid-based units and to an extent of 6 to 15 mol % from isophthalic acid-based units. The inventive films exhibit a surface elasticity modulus in the range from 4500 to 6400 N/mm2; a sum total of the strengths (σ5) in longitudinal direction and in transverse direction in the range from 170 to 220 MPa; a density of less than 1390 kg/m3; a haze of less than 2.0%; a clarity of at least 85%; a gloss of at least 120 and a thickness in the range from 50 to 300 μm. The invention further relates to processes for producing such films, and to the use thereof.