Intumescent composition exhibiting improved long-term expansion and

Abstract

A flexible, fire-retardant, intumescent composition comprising: a) an intumescent material; b) an effective amount of a stabilizing agent; and c) an organic binder throughout which the intumescent material and stabilizing agent are dispersed, the elastomeric binder being at least partially crosslinked, wherein the stabilizing agent consists essentially of a compound selected from the group consisting of compounds within general formula I ##STR1## wherein R.sup.1 -R.sup.4 inclusive are independently selected from the group consisting of hydrogen and alkyl groups having from 1 to about 5 carbon atoms, with the provisos that: i) either both of R.sup.1 and R.sup.2, or both R.sup.3 and R.sup.4 are alkyl groups having from 1 to about 5 carbon atoms; and ii) the stabilizing agent has a melting point ranging from about 105.degree. C. to about 125.degree. C. The stabilizing agent is present in an amount sufficient to render the composite expansion and compression set properties of the composition after prolonged exposure to oxidative conditions substantially unchanged.