METHOD OF IMPARTING REDUCED IGNITION PROPENSITY TO SMOKING ARTICLES USING PHASE TRANSITION MATERIALS

A method for imparting reduced ignition propensity properties to a smoking article by treating the smoking article wrapper with a phase transition substance which, upon being subjected to the heat of the smoking article burning firecone, physically transforms and at least partially fills the pores of the smoking article wrapper to reduce the permeability of the wrapper in the vicinity of the burning firecone. The reduced permeability of the wrapper in the vicinity of the firecone will permit sufficient air flow to sustain free burn, but, when the smoking article is placed on a substrate, the reduced permeability of the wrapper imparts reduced ignition propensity such that there is insufficient air flow to sustain combustion of the firecone or insufficient air flow to sustain an intensity of the burning firecone necessary to ignite the substrate.