Method and apparatus for making polyester web having high adhesion to coated layers

US5895744A · kind A · utility

Assignee

• EASTMAN KODAK COMPANY · US

Inventors

• Janglin Chen · Rochester, US
• Gerald G. Reafler · Rochester, US
• David A. Glocker · West Henrietta, US
• Mark Romach · Spencerport, US
• Richard C. Soper · Victor, US
• Evelio A. Perez-Albuerne · Rochester, US

Key dates

• Filing date: Feb 28, 1997
• Grant date: Apr 20, 1999
• Expiry date: Feb 28, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S422/907
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Method and apparatus for making thermoplastic web from polyester or polyester blends for subsequent aqueous coating without requirement of an undercoat or primer coat for adhesion of subsequent coatings. Feedstock pellets of polymer, such as polyethylene terephthalate or polyethylene naphthalate, are melted in a screw extruder. Molten polymer is extruded from an extrusion die as a thick, high-viscosity ribbon, which is tempered and stretched in both the machine direction and the transverse direction to form a web of biaxially-oriented polymer of the desired width and thickness. The web is heated to a temperature above T.sub.g to set the biaxial orientation and then is glow discharge treated by passing it through an in-line glow discharge apparatus at atmospheric pressure wherein a stable glow discharge is produced in a gas mixture containing helium between two electrodes connected by an alternating power source operating at a voltage between 0.5 kV and 20 kV at a frequency between 60 Hz and 40 MHz. The web is coated with an aqueous gelatin subbing layer. The coated web then is maintained at elevated temperature. The combination of glow discharge treatment before sub coating and hea…