Abstract
A novel chemical recycling process of phenolic resins has been developed. In this process, cured phenolic resin is completely decomposed in a very short reaction time and recycled resin is recovered in a very high yield by using supercritical or subcritical mixture of water and phenol as a reaction medium. Detailed kinetic analysis clarified the influences of particle size or glass transition temperature of cured phenolic resin and reaction temperature on apparent rate constant of decomposition. The recycled resin was used as alternative feedstock of conventional phenolic novolak and materials with the recycled resin had enough properties for practical use. It was confirmed that properties of the materials with the recycled resin did not decrease when the chemical recycling process was repeated several times. After basic engineering data was obtained with a continuous bench plant, a demonstration plant was constructed. Mass production development has been carried out.
