Eastman-kodak Company

Jonas Dedinas

George L Fletcher, Jr

Benzopinacol compounds can be prepared by an improved process comprising irradiating a diarylketone with UV radiation in a non-polar hydrocarbon solvent mixed with an alcohol. The volume ratio of the non-polar hydrocarbon solvent to alcohol is between 3:1 and 8:1. The benzopinacols are useful, for example, in imaging materials, such as with certain dyes that are reactive with the ketyl radicals that can be released from the benzopinacols upon heating.

Preparation of substituted benzopinacols

Benzopinacols represented by the formula: ##STR1## wherein R.sup.1 is hydrogen, alkyl or aryl;

Substituted benzopinacols

A light-sensitive vesicular imaging composition is disclosed comprising a vesiculating agent which liberates gas upon exposure to activating radiation, a binder and a diol speed-increasing agent. The composition is coated as a thin film. Imagewise irradiation of the element causes gas to be released in the exposed areas. The composition, comprising gas entrapped in a thermoplastic matrix, can be heated to produce a visible record.

Vesicular composition, element and process utilizing a diol

A heat bleachable layer comprising a benzopinacol and a reducible dye or dye precursor is useful in an imaging element. The heat bleachable layer can be, for instance, an antihalation layer of a photographic element, such as a photothermographic element.

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Pittsford, NY, United States of America

Jonas Dedinas