Polyvinyl-alcohol-based color resist for low-temperature color-filter production

A color resist comprising partially hydrolyzed polyvinyl alcohol, a crosslinker, a photoacid generator, and dyes was designed for color-filter production. The resist was photoexposed, followed by post-exposure baking, development, and curing at 150 °C to yield a solvent-resistant film. The degree of hydrolysis of polyvinyl alcohol affected the preparation of the homogeneous resist solution and the solvent resistance of the cured film. The cured film was insoluble in the resist solvent when the degree of hydrolysis was high, whereas the film displayed insufficient solvent resistance when degree of hydrolysis was low. Nanoindentation experiments of the polyvinyl alcohol film revealed good mechanical properties that were comparable to those of poly(methyl methacrylate). The crosslinking reaction of the polyvinyl alcohol film was analyzed by monitoring the amount of methanol, a volatile compound emitted during the curing of the film; the results suggest that the reaction was likely completed below the process temperature.