Reaction SMILES: [C:1]([OH:24])(=[O:23])[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][CH3:22].C(O)C.[OH-].[Na+:29]>O>[C:1]([O-:24])(=[O:23])[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][CH3:22].[Na+:29]
Reactant: CCCCCCCCCCCCCCCCCCCCCC(=O)O
Agent: [Na+]
Agent: [OH-]
Solvent: CCO
Solvent: O
Product: CCCCCCCCCCCCCCCCCCCCCC(=O)[O-]

Procedure:
8.5 g. of behenic acid were dissolved in 150 ml. of ethanol at 60° C. with stirring, and a solution of 1 g. of sodium hydroxide in 100 ml. of water was dropwise added at 60° C. with stirring to form sodium behenate. 200 ml. of hot water were then added to and sodium behenate was completely dissolved in about 70° C. with continuation of stirring. To the resulting solution was added a solution of 10 mg. of a dye of the formula 2 as described in the specification in 50 ml. of ethanol. Subsequently, an about 1/100 N aqueous nitric acid solution containing an equimolar amount, to that of the charged behenic acid, of silver nitrate was dropwise added at about 70° C. with stirring. The dissolved sodium behenate was converted to insoluble silver behenate. The silver behenate was colored blue violet. The obtained colored silver behenate was recovered by filtration and repeatedly washed with hot water of about 80° C., hot ethanol of about 70° C. and MEK. Washing was repeated until the washings were not colored. Then, the silver behenate colored with the dye was dried. To 12 parts by weight of the thus prepared silver behenate having the dye adsorbed thereon were added 88 parts by weight of a 2:1 solution of MEK-toluene and the resulting mixture was ballmilled for 24 hours to give a dispersion. To 6 g. of the dispersion was added a component I shown in Example 1. The obtained composition was applied, using a blade, onto a 100μ polyethylene terephthalate film at a thickness of 100μ on a wet basis and dried. Thereafter, a component II mixture shown in Example 1 was further applied thereonto, using a blade, at a thickness of 100μ on a wet basis and dried. A dry image forming material O was prepared. On the other hand, for comparison, a dry image forming material P was prepared by the same procedures as described above except that 0.014 g. of N-bromosuccinimide was used instead of bis(p-methoxyphenyl)tellurium dibromide. The above-mentioned dry image forming materials O and P were activated by heating at 100° C. for 3 seconds, then exposed at a distance of 1 m for 1 second to light from the 150 W. xenon lamp, with a 21-step steptablet laid upon said image forming materials, and heat-developed at 120° C. for 2 seconds. The optical densities of the formed images were measured. On the other hand, the materials O and P were exposed to light through a Toshiba glass color filter VR-60, VO-55, VO50, VY-45 and UV-39 (trade names of glass color filters manufactured and sold by Tokyo Shibaura Denki Kabushiki Kaisha, Japan), the color filters being disposed alone, or in layers with a view to excluding a short wave length light of the half wave length, between the 150 W. xenon lamp and the 21-step steptablet; and from the results the upper limits of the regions of photosensitizing wave lengths were determined. Fogs, sensitivities and upper limits of photosensitizing wave length are shown in Table 2. Sensitivities are values relative to that of a dry image-forming material R evaluated as 10.