Abstract: A radiation-sensitive mixture is described comprising a compound which produces a strong acid under the action of actinic radiation, a binder which is insoluble in water, but soluble in organic solvents and aqueous-alkaline solutions, and a compound of either of formulae I and II ##STR1## wherein R denotes a substituted or unsubstituted alkyl group,X denotes a hydrogen or halogen atom or a hydroxyl, alkyl, alkoxy, alkoxycarbonyl, aryloxy or aryl group, andn denotes zero or a number from 1 to 3.The mixture is suitable for the production of printing plates and photoresists and is distinguished by improved high flexibility along with good overdevelopment resistance.

Abstract: A process for separating higher molecular weight constituents from phenol polymers, wherein the phenol polymer is dissolved in an organic solvent medium, the solution obtained is mixed at room temperature with ammonia or an amine such that there is a stoichiometric deficiency of ammonia or amine, the precipitate is separate, dried, if appropriate, and treated with aqueous acid, and the resulting sediment is filtered off, washed and dried as described. The starting phenol polymer preferably is a condensation product of optionally substituted phenol and formaldehyde. The process yields fractions possessing an increased osmometric molecular weight, a narrower molecular weight distribution range and an increased glass transition temperature.