for light sensitive resistbekledingspreparaat and light sensitive product and method for manufacturing a litho - printing plate.

摘要

A photosensitive resist compsn. comprises a soln. in organic solvent of a mixt. of (a) a polyvinylformal (PVF) which is insoluble in water but soluble in organic solvent, has a formal content of 80-100% (based on PVF) and is prepd. by reacting an aldehyde chosen from formaldehyde, its 19:1 mixt. with acrolein and its 9:1 mixt. with crotonaldehyde, with a water soluble polyvinyl alcohol with a mol wt. 16000-100,000 and hydrolysis degree 80-100%, in a reactn. medium comprising 1,4-dioxane or acetic acid and contg. an inorg. acid catalyst, and (b) an aryl diazide which is soluble in organic solvent and is a photosensitiser and crosslinking agent for the PVF. The compsn. is used for prodn. of lithographic printing plates and printed circuits. It is storage stable and forms dried layers which are thermally stable and which after exposure to light are strongly resistant to solvents (e.g. in printing inks) in the exposed regions. Specifically the dried layer is stable when heated at 121 degrees C for 30 mins.