| abstract |
An optical filter, which is capable of cutting-off unnecessary near infrared rays, neon light or the like, and preventing reflection of fluorescent light or the like, in plasma display panels and the like, at the same time, superior in transmittance for visible light, and also superior in heat resistance, moisture resistance, and the like of the coloring matter contained, had been desired. The present invention was made to solve such problems. The present invention relates to an optical filter comprising a salt of a cation of a cyanine coloring matter with a di(halogenoalkylsulfonyl)imide anion, preferably a cyanine compound represented by the following formula:n n(wherein, in the above formula (1), each of Q and Q' independently represents a benzene ring or a naphthalene ring which may have a substituent; each of R and R' independently represents an alkyl group or an alkoxyalkyl group; and L represents a linking group to form a carbocyanine), and useful as a filter for cutting-off near infrared rays, improving image characteristics for displays or the like. |