NEAR INTRARED-ABSORBING CYANINE PIGMENT AND USE THEREOF

摘要

The problem addressed by the invention is to provide a novel near infrared-absorbing cyanine pigment and a near infrared absorbent comprising same. The problem is solved by providing a benzo [c,d] indolium heptamethine cyanine pigment represented by formula (1) and a near infrared absorbent comprising same. (In formula (1), R1 and R2 each independently represent C1-5 straight or branched alkyl groups. R3 and R4 each independently represent hydrogen atoms or substituting groups. X- represents a counter anion.)