Mitsui Toatsu Chemicals, Incorporated

Yamamoto Chemicals, Inc.

Hisao Itoh

Takahisa Oguchi

Katashi Enomoto

Tutomu Nishizawa

Near infrared absorbers which have a molecular extinction coefficient of 200,000 or more and are represented by the formula (I) ##STR1## wherein each of Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4, Y.sup.5, Y.sup.6, Y.sup.7 and Y.sup.8 is hydrogen, an alkyl group, alkoxyl group or alkylthio group; each of A.sup.1, A.sup.2, A.sup.3, A.sup.4, A.sup.5, A.sup.6, A.sup.7 and A.sup.8 is hydrogen, halogen, a nitro group, alkyl group, aralkyl group, alkenyl group, alkynyl group, alkoxyl group, aryloxy group, alkylthio group or arylthio group; and Met represents two hydrogen atoms or a metal, are useful for the production of optical display and recording materials.

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Yokohama, Japan

Hisao Itoh