Intumescent coating system

Abstract

An intumescent coating system contains: a polyol component; an isocyanate component; a latent crosslinker having two or more —NACH2OR groups, where A is selected from a group consisting of H and —CH2OR, and in each case R is independently selected from a group consisting of hydrocarbons having from one to four carbons, the latent crosslinker being present at a concentration of 30 weight-percent or more based on polyol weight; a boron component one weight-percent or more and 10 weight-percent or less based on total weight of the formulation; and expandable graphite at a concentration of 10 weight-percent or more and 50 weight-percent or less based on the total intumescent system weight; where the polyol and isocyanate are selected so that the reaction product at room temperature of the intumescent coating system components produces a coating having a tensile elongation of 40-percent or more as determined according to ISO 37.

Dependencies are inferred from the claim text.