PREPARATION OF PHENOL FOAM AND PHENOL FOAM PREPARED THEREWITH

摘要

PURPOSE:To improve the friability, shrinkage during foaming, and permanent set of a phenol foam by placing a fiber or fabric to a phenol resin compsn. and irradiating the compsn. with a high-frequency wave to foam and cure the compsn. CONSTITUTION:The title foam is prepd. by placing a fiber or fabric into and/or on the surface of a phenol resin compsn. and irradiating the compsn. with a high frequency wave to foam and cure the compsn. The fiber or fabric pref. comprises a composite fiber consisting of one component which has a low dielectric constant and hardly generates heat when irradiated with the high-frequency wave and the other component which has a high dielectric constant and easily generates heat when irradiated. When the compsn. contains a highly water- absorbent resin, it can be foamed and cured more effectively by the irradiation, giving a phenol foam having further improved friability and surface uniformity.