PURPOSE: To obtain iridium resinate which can be dissolved in an ordinary org. solvent and is formed into a uniform thin film by a dimple operation such as coating, drying, baking, etc., by reacting an Ir compd. with an org. acid or with a mixture of an org. acid with ammonia or an amine directly or mixed with turpentine oil as a solvent.

CONSTITUTION: An Ir compd. e.g., a halide, an oxide or a sulfate is reacted with an org. acid, e.g., 2-ethylhexanoic acid, octanoic acid, naphthenic acid, arom. carboxylic acids, abietic acid or a gum rosin contg. abietic acid as the main component or with a mixture of an org. acid with ammonia or an amine selected from among prim., sec. and tert. amines, e.g., n-propylamine, diethylamine, or triethylamine directly or mixed with turpentine oil as a solvent and a produced oily substance is extracted with, e.g., an org. solvent (e.g., CHCl3) to remove water and thereafter the org. solvent is evaporated.