Process for producing negative copies by means of a material based on 1,2-quinone diazides with 4-ester or amide substitution

Claim 1

A process for producing negative relief copies, comprising the steps of: (a) imagewise exposing a light-sensitive material to light through an original, said material comprising a light-sensitive layer which consists essentially of (1) a binder that is insoluble in water and soluble in aqueous-alkaline solutions and (2) an amount of a 1,2-quinone diazide sufficient to render said layer light-sensitive, said diazide comprising at least one of an ester and an amide of one selected from the group consisting of a 1,2-benzoquinone-2-diazide-4-sulfonic acid, a 1,2-benzoquinone-2-diazide-4-carboxylic acid, a 1,2-naphthoquinone-2-diazide-4-sulfonic acid, and a 1,2-naphthoquinone-2-diazide-4-diazide-4-carboxylic acid, such that said diazide undergoes photodecomposition; thereafter (b) heating said material, such that cross-linking is effected in portions of said light-sensitive layer exposed to said light; (c) after (b), cooling and then exposing said material again without said original, such that portions of said light-sensitive layer not exposed during step (a) are rendered alkali-soluble; and then (d) developing said material with an aqueous-alkaline developer, such that said portions of said layer rendered alkali-soluble are solubilized.