PRODUCTION OF SULFONIUM SALT

摘要

PROBLEM TO BE SOLVED: To obtain a sulfonium useful as a photo-acidic initiator and a photo- radical initiator in a polymerization, and as a photo-acid generator by reacting a sulfoxide compound, an aromatic compound and a perfluoroalkane sulfonic acid anhydride with each other. SOLUTION: In this method for producing a sulfonium salt, an objective compound formula IV (Rc is an alkyl), (e.g. a compound of formula V) is obtained by reacting a sulfoxide compound of formula I (Ra, Rb are each an alkyl or the like), preferably 1-100 equivalent aromatic compound of formula II (R1, R2 are each H, an alkyl or the like) based on the sulfoxide and preferably 1-5 equivalent perfluoroalkane sulfonic acid anhydride (e.g. trifluoromethane sulfonic acid anhydride) by preferably using a reaction solvent such as a haloalkane compound (e.g. dichloromethane) at a temp. of (-)80-100 deg.C. In using the compound as an additive for a photoresist, it is preferable to use 0.510 wt.% based on a photoresist polymer.