Chromogenic methylenepyrrolines

U.S. Patent Number: 5387694

Abstract: The present invention relates to chromogenic methylenepyrrolines and processes and intermediates for their preparation and to their use. The chromogenic methylenepyrroline compounds according to the invention have the formula (I) defined in claim 1. These colour formers are suitable in particular for thermographic recording processes and produce intensive red, violet, blue or brown colourations. They are distinguished by the fact that they do not require any conventional electron-withdrawing acid colour developer.

Inventors: Bedekovic; Davor (Biel-Benken, CH)

Assignee: Ciba-Geigy Corporation (Ardsley, NY)

Application Number: 08/052,301

Issued: 1995-02-07

Expired: 2007-02-07

Classes: 548/458 ; 548/364.7; 548/440; 548/466; 548/471

Field of search: 548/364.7,440,458,466,471

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