Visibly opaque infrared transmitting optical filter containing a combination of copper and vanadyl phthalocyanine sulfonamides

Claim 1

An optical filter which is substantially opaque to visible light but which is transparent to light in the near infrared region comprising a plastic substrate having substantially uniformly dispersed therein, a copper phthalocyanine sulfonamide compound having the formula: ##STR3## wherein Pc is the phthalocyanine moiety, R 1 and R 2 are alkyl groups containing from 1 to 4 carbon atoms or R 1 is hydrogen and R 2 is an alkyl group containing from 4 to 20 carbon atoms; X is a number from 1 to 4, provided that not more than 1 sulfonamide group is present on any single phenyl ring of the phthalocyanine moiety; a vanadyl phthalocyanine sulfonamide compound having the formula: ##STR4## wherein Pc is the phthalocyanine moiety and R 3 and R 4 are alkyl groups containing from 1 to 4 carbon atoms or R 3 is hydrogen and R 4 is an alkyl group containing from 4 to 20 carbon atoms and X is a number from 1 to 4, provided that not more than one sulfonamide group is present on any single phenyl ring of the phthalocyanine moiety; and an auxiliary organic dye compound capable of absorbing visible light but which does not absorb in the near infrared; said copper phthalocyanine sulfonamide compound being present in the substrate in a weight percent concentration such that said concentration multiplied by the thickness of the substrate in mils is a constant falling within the range of from about 0.02 to about 6.13 and said vanadyl phthalocyanine sulfonamide compound being present in the substrate in a weight percent concentration such that said concentration multiplied by the thickness of the substrate in mils is a constant falling within the range of from about 0.01 to 0.3.