GB490516A - Improved filters which absorb ultra-violet light - Google Patents

Abstract

490,516. Photographic colour filters. GROVES, W. W. (I. G. Farbenindustrie Akt.- Ges.) Nov. 16, 1936, No. 31291. [Classes 97 (i) and 98 (ii.)] In a filter layer suitable for photographic purposes and which absorbs ultra-violet light, more especially one which is superimposed on a light-sensitive photographic layer, the layer forming colloid contains as the active ingredient a colourless or slightly coloured substance which absorbs ultra-violet light and is fast to diffusion in the colloid. The active ingredient contains in the molecule the residue of a substance which absorbs ultra-violet light, such as 2-oxychrysene-8-carboxylic acid, 2-oxyanthracene-3-carboxylic acid, 2-oxychrysene, 3-oxy- and 3-aminopyrene, umbelliferone, methylumbelliferone and other derivatives of umbelliferone, fluorene and its derivatives, and derivatives of naphthalene. A suitable molecular residue is also included to impart fastness to diffusion. Examples are carbamide derivatives such as the carbamide from 2 mol. para-aminobenzoyl - para - phenylaminediamine sulphonic acid, benzidine derivatives such as the benzidide of 2 : 3-oxyanthracene carboxylic acid, derivatives of diamino-stilbene, of diaminodiphenylurea, of dia,minodiphenyl thiourea, or of aminobenzoyl and benzilidine compounds. Heterocyclic residues, particularly those containing the cyanuric ring, may also be used. Substances containing carbon chains of five or more atoms may be used, as, for example, aliphatic residues, fatty acid residues, carbohydrate residues, residues of a peptide character, for example of natural albuminous substances or of degradation products thereof, or polymerizates from ethylene oxide and its analogues and homologues. Examples of such substances are stearic acid chloride, cetyl iodide, ethylene imines, serum albumin, rice starch, undecylic acid chloride. Instead of a chain structure hydrogenated rings may be used as in perhydro-4-aminodiphenyl, #-aminodecaline or 4 : 4<1>-diaminodecahydrodiphenyl. Alternatively, there may be used a residue of a constituent of high molecular weight of a natural resin or of a conversion product of such a constituent, such as abietic acid. Sterols or their conversion products such as chloresterol dicarboxylic acid or its scission products may also be used. Specification 436,587 is referred to.