Abstract: The present invention relates to an aminium salt or diimonium salt compound that is appropriate for use, for examples, in an optical recording medium to get the good characteristics in regeneration and storage stability as well as an infrared ray screening filter to get the excellent light fastness and heat fastness; and the use thereof. The aminium salt or diimonium salt compound comprises an aminium cation represented by the formula (1) as described below or a diimonium cation represented by the formula (2) as described below: (In the formula, m is an integer of 1 or 2; the two nitrogen atoms (quaternary nitrogen atoms in Formula (2)) bound to the ring A in Formula (1) or Formula (2) bind to the four B phenyl groups to whose 4-positions the optionally substituted four amino groups are substituted; and at least one of said four amino groups has a cyanoalkyl group as the substituent) with an anion.

Abstract: The invention discloses a method for dyeing a hydrophobic fiber, in particular, a polyester fiber in an extremely brilliant yellow or orange with fluorescence, a method for coloring, for example, a polystyrene resin or a polyacrylate resin in a brilliant yellow or orange, and a coloring material therefore.A method for dyeing a hydrophobic fiber and a method for coloring an organic macromolecular substance characterized by using a coumarin compound represented by the general formula: ##STR1## wherein R.sub.1 and R.sub.2 independently represent each a hydrogen atom or an alkyl group having 1 to 4 carbon atoms;and a coloring material containing the coumarin compound are disclosed.