Patent ID: 8778456

Claim:
A method of forming a coating on a substrate, said method comprising the steps of: providing an isocyanate component comprising toluene diisocyanate (TDI); providing a carbodiimidization catalyst; providing a first solvent having a boiling point temperature of from about 50 to about 150° C.; polymerizing the isocyanate component for a first period of time in the first solvent and in the presence of the carbodiimidization catalyst to produce a reaction mixture including at least one carbodiimide compound and the first solvent; combining a second solvent, which is the same as or different from the first solvent, and the reaction mixture; polymerizing the at least one carbodiimide compound for a second period of time in the first and second solvents and in the presence of the carbodiimidization catalyst to produce a high molecular weight polycarbodiimide having a weight average molecular weight of at least about 100,000; and applying a coating composition comprising the high molecular weight polycarbodiimide on the substrate to form the coating.