METHOD FOR PREPARING PHENOLIC FOAMS USING ANHYDROUS ARYL SULFONIC ACID CATALYSTS

摘要

AbstractThe present invention is directed to a method of preparing a phenolicfoam that has cell walls which are substantially free of perforations. Themethod comprises using certain anhydrous aryl sulfonic acids as the foamingand curing catalysts. The useful anhydrous aryl sulfonic acids are thosewhich have a pKa of less than about 2.0 and which change the compatibility ofthe phenolic resole with water. The preferred anhydrous aryl sulfonic acid isa combination of toluene sulfonic acid and xylene sulfonic acid. The inven-tion is also directed to a phenolic foam having cell walls which are substan-tially free of perforations and to foamable phenolic resole compositions forpreparing the phenolic foam.