ASYMMETRIC SQUARILIUM COMPOUND AND FILTER CONTAINING THE COMPOUND AND USED FOR IMAGE DISPLAY EQUIPMENT

摘要

PROBLEM TO BE SOLVED: To provide a coloring compound which, when contained in a filter for image display equipment, effectively intercepts unnecessary light with a wavelength of about 580 nm emitted from the image light source of color image display equipment, giving an image excellent in contrast and color reproducibility. SOLUTION: The asymmetric squarilium compound is represented by formula (1) (wherein R1to R4are each a hydrogen atom or an optionally sybstituted alkyl, alkenyl, alkoxycarbonyl or phenyl group; R5to R7are each an optionally substituted alkyl group; and R8is a hydrogen or halogen atom or an optionally substituted alkyl or alkoxy group). COPYRIGHT: (C)2004,JPO