POLYVINYL ACETATE SAPONIFICATION PRODUCT-BASED PHOTOSENSITIVE RESIN, AND PHOTOSENSITIVE RESIN COMPOSITION AND FORMATION OF PATTERN USING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain the subject resin having good water resistance and developability and having an excellent patterning property by adding specific structural unit each having a quaternized aromatic nitrogen-containing heterocyclic ring. SOLUTION: This polyvinyl acetate saponification product-based photosensitive resin contains structural units of formula I or II [R1 is an alkyl, an aralkyl or the like; R2 is H or a lower alkoxy; (m) is 0 or 1; (n) is 1-6; a group of formula III is the cation group of a quaternized aromatic nitrogen-containing heterocyclic group; X1- is an anion originated from a dibasic or higher polybasic acid having a pK1 value of <=3.5; X2- is an anion except X1-] in an amount of 0.5-10 mol.% based on the structural units of the polyvinyl acetate saponification product. The polyvinyl acetate saponification product-based polymer is obtained by reacting a water-soluble copolymer of the polyvinyl acetate saponification product or vinyl alcohol with one or more other vinyl compounds with an aldehyde compound of formula IV or an acetal compound of formula V in the presence of an acid catalyst in an aqueous medium.