Eastman-kodak Company

Richard C Soper

David A Glocker

Mark M Romach

Evelio A Perez-Albuerne

Janglin Chen

Dennis R Freeman

Gerald G Reafler

Apparatus capable of sustained glow discharge at atmospheric pressure mounted along the web path in a web coating machine ahead of the point of coating application, for glow discharge treatment of the surface of a polymeric web shortly before coating. Latencies of treatment (the time between treatment and coating) approaching zero are possible, minimizing or preventing loss of treatment effect and maximizing adherence of a coated layer to the web surface. Elimination of one or more conventional subbing adhesion layers on the web surface is possible in some applications.

Glow discharge treatment of a web substrate surface in a web coating line

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 heat treatment after sub coating greatly enhances the adhesion of subsequently-coated aqueous gelatin layers such as photographic emulsions to the web, sufficiently that adhesion-promoting U-coat or primer coat as required in prior base-making methods can be omitted.

Method and apparatus for making polyester web having high adhesion to

The present invention is a method for treating a polyester support such as polyethylene naphthalate or polyethylene terephthalate. The treatment is carried out at atmospheric pressure in a gas of helium and optionally nitrogen and/or oxygen. The treatment uses metallic electrodes and an atmospheric glow discharge results when the electrodes are connected to a generator and spaced about 1 to 2 mm apart. The process and apparatus improve adhesion of subsequently coated emulsions on the polyester support at high speeds and relatively low power by selecting a frequency of 40 kHz to 500 kHz.

Atmospheric pressure glow discharge treatment of base material for

A cobalt-platinum (CoPt) magnetic film is deposited onto a chromium (Cr) or tungsten (W) underlayer on a substrate, or is deposited directly onto the substrate and has an appreciable component of its C-axis which is parallel go the [00.2] direction, lying in the plane of the film whereby the resultant magnetic films exhibit coercivities from 2100-3000 oersteds.

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Victor, NY, United States of America

Richard C Soper