NEAR INFRARED RAY TRANSMITTING AND DARK COLORED AZO-BASED PIGMENT COMPOSITION

PROBLEM TO BE SOLVED: To increase distinction and tinting strength and restrain random reflection of near infrared ray by making a composition comprising a dark colored azo-based pigment having a specific average particle diameter and a transmitting carrier therefor have a specific value of transmittance of near infrared region. SOLUTION: A crushed dark colored azo pigment having an average particle diameter of 0.01-1.0 μm represented by the formula is mixed with a predetermined amount of a transmitting carrier material such as a vehicle resin, oil or a binder resin, etc., to prepare an azo-based pigment composition having 80-100% of a transmittance of light in near infrared region of 750-1,200 nm. The vehicle resin to be used for printing ink includes a natural resin such as a dry oil, a rosin, etc., a petroleum resin, a phenol resin, etc., and the vehicle resin to be used for coating includes a natural resin, an alkyd resin, an amino resin, an epoxy resin, etc., wherein A in formula is a residual group of a diazo component of the azo pigment, halogen, a 1-3C alkyl group, or the like; B is phenyl, naphthyl, phenylene, or the like which may have a substituted group represented by X1 ; and n is 1 or 2.