Supercritical-Carbon-Dioxide Solubility Characteristics of Polyphenols and Polyphenol Derivatives

Abstract

Supercritical carbon dioxide (scCO₂) solubility characteristics of various polyphenols and their derivatives were investigated for the sake of resist materials for scCO₂ development. Some 3 nuclei-polyphenols were fairly soluble in scCO₂ at the condition of pressure: 15MPa, temperature: 38 °C. Among various subustituent groups, only carboxylic acid COOH structure was a strong dissolution-inhibition factor, but other polar groups, hydroxyl, carboxylic-acid ester structures, such as methyl, ethyl, ter-butyl esters, were not fatal dissolution-inhibition factors in the films for scCO₂. It was presumed that existence of hydrogen bonding interaction in the film strongly affect the film dissolution in scCO₂.