US 4,767,571 A · Infrared absorbent

Abstract

The present invention relates to an infrared absorbent comprising a metal complex. With the use of the infrared absorbent, there is provided an infrared absorbing material capable of absorbing near infrared light having a wavelength of 700-1500 nm or far infrared light with a high transmittance of visible light and a good fastness to heat and light. The infrared absorbent is suitable for various applications such as a safelight filter for infrared sensitive materials, control of growth of plants, cut-off of heat radiation, infrared cut filter harmful to tissues of human eyes, infrared cut filter for semiconductor light receiving elements or color solid image pick-up elements, and infrared cut filter for an optoelectronic integrated circuit wherein electrical and optical elements are incorporated in the same substrate.

Claims30

Dependent claims

A compound having the formula:

##STR13## wherein:
M represents copper, cobalt, nickel, palladium or platinum;
cat represents a cation to neutralize a complex;
R.sub.1 to R.sub.8 each independently represents a member selected from the group consisting of a hydrogen atom, alkoxy group, amino group, halogen atom, cyano group, hydroxyl group, alkyl group, aryl group and heterocyclic group, said heterocyclic group being a 5-membered or a 6-membered ring containing at least one nitrogen, oxygen or sulfur atom as a hetero atom therein, said alkyl, aryl or heterocyclic group optionally being bonded through a divalent connecting group, which may be the same or different, to a benzene ring with the proviso that at least one of said R.sub.1 to R.sub.8 is an electron donating group when said Cat is a cation other than a quaternary phosphonium or iminium cation.

1 more element

Dependencies are inferred from the claim text.

Infrared absorbent

Life of this patent

Infrared absorbent

Life of this patent

Abstract

Claims30