DIIMONIUM SALT COMPOUND, NEAR-INFRARED ABSORBING FILTER AND OPTICAL INFORMATION RECORDING MEDIUM USING THE SAME

摘要

Near infrared ray absorbing filter contains >=1 di-immonium salt compound. Near infrared ray absorbing filter contains >= 1 compound of formula (I); [Image] R 1-R 8>=1 is branched alkyl group; rings A and B : may be substituted; X : an anion necessary for neutralizing the electric charge. Independent claims are also included for: (1) a near infrared ray absorbing composition formed by adding the compound (I) to a resin; (2) a di-immonium salt compound; and (3) an optical information recording medium which contains (I) a recording layer.