To obtain a polymer binder capable of preparing a highly sensitive radiation-sensitive mixture which is capable of both positive and negative treatments and of alkali development, by reaction of a specific polymer with a dihydropyran or the like.
This polymer binder is obtained by reaction of the hydroxyl group of (A) a phenolic hydroxyl group-bearing polymer with (B) a dihydropyran or (C) an alkyl vinyl ether, or by polymerization or polycondensation of the reaction product from the hydroxyl group of (D) a phenolic hydroxyl group- bearing monomer with the component B or C. It is preferable that 10-100% of the hydroxyl group of the component A is reacted with the component B or C, and the component A is a p-cresol/formaldehyde-predominant novolak, specifically, poly-(p-hydroxystyrene), poly-(p-hydroxy-α-methylstyrene) or p- hydroxystyrene/p-hydroxy-α-methylstyrene copolymer.
BINDER HORST
