Minnesota Mining and Manufacturing Company

John H Stibbard

Sharon Mary Simpson

Doreen Catherine Lynch

Ranjan C Patel

Andrew W Mott

Justine A Mooney

Robert J Nairne

Stephen S Poon

Duncan M Grieve

Terence William Baldock

Donald J Newman

David C Bays

Kim Marie Vogel

Kevin D Landgrebe

Roger A Mader

John J Stofko, Jr

Gilbert L Eian

Raymond J Kenney

Takuzo Ishida

Michael G Fisher

Ronald G Tye

Darren Cooper

William E Bottomley

Ranjana C Patel

A thermographic element comprising in a non-aqueous binder medium a silver salt oxidizing agent in reactive association with a compound comprising a plurality of redox color releasing moieties such that oxidation of each redox color releasing moiety causes release from said compound of a thermally diffusible dye. The compounds many of which are new incorporate two or more developer moieties into a single molecule to minimize the diffusibility of the compound. Following oxidation, either directly by the silver salt or by means of a cross-oxidizing agent, each oxidized developer moiety releases a thermally diffusible dye. The compounds are of sufficient size and molecular weight to slow or prevent diffusion in imaging systems and yet possess several active developer moieties per molecule which is advantageous over known ballasted dye releasers which comprise bulky molecules with only a single developer moiety.

Developing agents for (photo) thermographic systems

A photothermographic element comprising a support bearing at least one heat-developable, photosensitive, image-forming photothermographic emulsion layer comprising:

Hydrazide redox-dye-releasing compounds for photothermographic elements

A negative-acting, photothermographic material having a first layer comprising an amine compound and a second layer comprising an amine-reactive dye which undergoes a visible change when in reactive association with the amine compound. The amine compound and the amine-sensitive dye are in non-reactive association at ambient and moderate temperatures, but at elevated temperatures the two components are able to interact to produce a visible change in the heated areas of the material. The materials are particularly suitable for the preparation of overhead projector transparencies.

Negative-acting thermographic materials

Method and apparatus for producing a color image on a photosensitive medium having low sensitivity in which color separation image masks are sequentially generated in a smectic liquid crystal device which may be controlled by a computer and the photosensitive medium is exposed through the image mask. The separation image masks may be altered during exposure to compensate for uneven illumination and to achieve tonal scales.

Imaging slow photographic media with liquid crystal shutters

Images can be formed on a receptor sheet by transfer of a dye image. The positive dye image is formed by bleaching of dye with an iodonium ion. The positive dye image is then transferred by sublimation or diffusion onto a receptor sheet.

Diffusion or sublimation transfer imaging system

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Harlow, United Kingdom

John H Stibbard