SELF LIMITING MICROWAVE SUSCEPTOR

摘要

A self limiting dispersion of a conductive material in a binder is disclosed wherein the conductive material consists essentially of a carbon material having a structure selected to undergo percolation when dispersed in the binder at a concentration of from about 10 weight percent to about 45 weight percent. The binder comprises a thermoplastic material selected to go through a first order phase transition or a second order transition at a temperature from about 200 .degree.F to about 480 .degree.F and the dispersion is formulated near the conductance percolation threshold so that its electrical conductivity drops precipitousl y ((e.g., at least about 1.5 to about 2 orders of magnitude) above the binder transition temperature. The dispersion of the conductive material in the binder is especially suitable for use as a self-limiting microwave heater material which is either a molding composition, surface coating composition, and especially a composition that can be applied to a substrate by printing.