PREPARATION OF PHENOLIC RESIN FOAM HAVING EXCELLENT FLAME RESISTANCE

摘要

PURPOSE:To prepare a phenolic resin foam having excellent flame resistance and heat insulation, high ratio of closed cell, and free from corrosion of metals contacted with the foam, by mixing a resol-type phenolic resin with a specific epoxy compound, an acid catalyst, and a foaming agent. CONSTITUTION:The objective foam is prepared by foaming a composition prepared by mixing (A) a resol-type phenolic resin, with (B) an epoxy compound of formulaI(n is =1) (preferably glycerol diglycidyl ether), (C) an acid catalyst (preferably p-toluenesulfonic acid, etc.) and (D) a foaming agent (preferably a low-boiling volatile organic compound) wherein the amount of the epoxy resin and that of the acid catalyst (Y) are selected to fall within the tetrogonal range defined by the points A(0.060, 0.0475), B(0.079, 0.0550), C(0.150, 0.070), and D(0.060, 0.0355) in a rectangular coordinate system taking the amount of the epoxy compound as the X-axis (mol/100g of phenolic resin) and that of the acid catalyst as the Y-axis (mol/100g of phenolic resin), provided that (Y) satisfies the formula II (R is reactivity index of the resol-type phenolic resin).