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Thermographic Copying Material for Preparation of Refractive Images

IP.com Disclosure Number: IPCOM000097820D
Original Publication Date: 1961-Jul-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Lindquist, RM: AUTHOR [+3]

Abstract

Refractive images are formed by supersaturating a polymeric film with gas and exposing the film to image defining infra-red radiation. The images are formed on expansion of the supersaturating gas to form bubbles within the film at temperatures below the melting point of the film.

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Thermographic Copying Material for Preparation of Refractive Images

Refractive images are formed by supersaturating a polymeric film with gas and exposing the film to image defining infra-red radiation. The images are formed on expansion of the supersaturating gas to form bubbles within the film at temperatures below the melting point of the film.

Polymer films which are useful in the process include polycarbonates, polyvinyl chloride, polyvinylidene chloride, co-polymers of these halo polymers, polyamides such as nylons, polyesters such as polyethylene glycol terephthalate, polymethyl a -chloroacrylate, polystyrene, polyacrylonitrile and cellulosic polymers such as nitro-cellulose and ethylcellulose.

These films are supersaturated with inert gases, such as nitrogen, argon, carbon dioxide, air and Freons. Gas pressures of about 30 to about 500 atmospheres are preferred for supersaturating the films.

The supersaturating gas remains in the film a period of time ranging from a few minutes to a few days at ambient room temperatures and pressures.

The films are exposed by direct or reflected infra-red radiation. Thus, a gas supersaturated film is placed on a source document and irradiated with infra-red light. Heat from the black image areas of the document re-enters the film and heats the trapped gases to form small bubbles. Alternately, the film can be exposed through a stencil or by other usual means. These bubbles scatter light and render the image areas opaque. T...