PHOTOCHEMICAL GENERATION OF DYES

摘要

A photosensitive element for the production of near infrared absorbing images having a photosensitive medium comprising a trialkyl orthoester, a photochemical source of a strong acid and a compound of the formula (I): <CHEM> in which: n is 0 or 1, R<1> and R<2> independently represent hydrogen or an alkyl group of up to 5 carbon atoms and Ar1 and Ar2 represents aryl groups bearing an electron-donating substituent in the 4-position.