 gelling agent for lubricating fluids, modifiers for electrodes, charged coating agents etc.The Monstral blue found to coat the inside of copper vessels used to process phthalic acid derivatives had led to the discovery of Phthalocyanine in 1907.Attracted by the brilliance, stability and insolubility of this chromophore, attempts were made to reversibly modify it so that it would be carried into fabric in a solution and then easily precipitated (ingrained) into an unleachable but finely well dispersed deposit (hence the name "ingrain dyeing").