Method of forming a positive image through infrared exposure utilizing diazonaphthoquinone imaging composition

摘要

An infrared imaging composition contains two essential components, namely an infrared absorbing compound, and a phenolic resin that is either mixed or reacted with an o-diazonaphthoquinone derivative. These compositions are useful in positive-working elements such as lithographic printing plates that can be adapted to direct-to-plate imaging procedures. The weight ratio of infrared radiation absorbing compound to diazonaphthoquinone moiety is less than 1:14.