Near-infrared absorbing composition comprising at least two cyanine compounds

摘要

PPROBLEM TO BE SOLVED: To provide a practicable near-infrared-absorbing composition comprising at least two kinds of cyanine compounds, and having excellent absorption and heat fastness. PSOLUTION: The near-infrared-absorbing composition comprises at least two kinds of the cyanine compounds having different absorption maximum wave lengths, and has the absorption maximum wave length at the position different from the absorption maximum wave length of each of the cyanine compounds. At least one kind of the cyanine compounds is represented by general formula (1) [wherein, ZSP1/SPand ZSP2/SPare each independently a nonmetallic atom group forming a 5- or 6-membered nitrogen-containing heterocyclic ring which may be fused; RSP1/SPand RSP2/SPare each independently an aliphatic group; LSP1/SPis a methine chain which comprises five to seven methines which may form a ring; (a) and (b) are each independently 0 or 1; with the proviso that at least two or more anionic groups are present in the molecule]. PCOPYRIGHT: (C)2009,JPO&INPIT