FOAMED PHENOLIC RESIN COMPOSITION

摘要

PURPOSE:To obtain a foamed phenolic resin composition having uniform cell structure, smaller cell size and high closed cell ratio, by using a specific surfactant in the production of a foamed phenolic resin composition with a low-boiling organic foaming agent together with a surfactant and an acidic curing agent. CONSTITUTION:The objective foamed phenolic resin composition can be produced by foaming and curing a precondensate of a resol-type phenolic resin with one or more kinds of surfactants of formula (R1 and R2 are H or methyl; n1 and n2 are >=1; n1+n2=2-50) in the presence of an acidic curing agent (e.g. hydrochloric acid) and an organic foaming agent (e.g. petroleum ether). The amount of the surfactant is preferably 0.5-5pts.wt. per 100pts.wt. of the resol-type phenolic resin precondensate.