EXPANDABLE PHENOLIC RESIN COMPOSITION AND METHOD OF PRODUCING THE SAME

摘要

An expandable phenolic resin composition comprising 100 parts by weight (in terms of solids content) of liquid resole phenolic resin, 3 to 100 parts by weight of an acidic curing agent, 1 to 50 parts by weight of a blowing agent, 0.1 to 50 parts by weight of a sugar, and 0.1 to 10 parts by weight of a foam stabilizer as the essential ingredients, wherein use is made of a foam stabilizer comprising a partially or wholly acetylated castor oil/ethylene oxide adduct having a hydroxyl value of 15 mgKOH/g or less produced by acetylating a castor oil/ethylene oxide adduct produced by the addition reaction of 1 mol of castor oil with 20 to 70 mol of ethylene oxide, and/or a liquid resole phenolic resin produced by the addition/condensation reaction of a phenol with an aldehyde in the presence of a catalyst capable of forming a metal ion, wherein the amount of a residual catalyst is less than 0.1 part by weight (in terms of metallic element) per 100 parts by weight (in terms of solids content) of the phenolic resin. This composition is excellent in embrittlement resistance, heat insulation and long-term stability, and provides a phenolic resin foam which does not lose its excellent heat insulating property even by a reduction in the density or a change in the ambient temperature.