Process for purifying vinylphenol polymers for use as photoresist materials.

摘要

Recently, vinylphenol polymers have been gathered special attentions as the materials of photoresists, because they can give materials having excellent transmittance of deep ultraviolet light in the neighborhood of 248 nm. Vinylphenol polymers usually contain, however, metal impurities for many reasons. Photoresists must have high transmittance and extremely low metal content. Vinylphenol polymers satisfying such requisitions were not prepared in industrial scale, yet. A process for producing such purified vinylphenol polymers economically with ease is disclosed herein. The process is very simple and comprises hydrogenating a vinylphenol polymer solution and contacting the hydrogenated solution with a strongly acidic cation exchange resin.