Abstract: Compounds of the formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are hydrogen or alkyl, X represents the atoms to complete an aromatic heterocyclic ring system and Y is hydrogen or has the meaning assigned to X, are readily cleaved in alkaline solutions to release a hydroquinone derivative.The compounds can be incorporated into photographic materials used for activation processing.

Abstract: Photographic silver halide material which comprises at least one silver halide emulsion layer coated on a support, there being present in the silver halide emulsion layer(s), or in a layer in operative contact with at least one silver halide emulsion layer, a compound of the formula ##STR1## wherein W is hydrogen, alkyl, --NHCOR.sup.1 or --COR.sup.1, wherein R.sup.1 is alkyl or alkenyl, cycloalkyl, aralkyl, aryl, phenoxymethylamino or halogen; X is a substituent in the coupling position and is a leaving group selected from hydrogen, chlorine, bromine, --SR.sup.11 wherein R.sup.11 is alkyl, aryl or a heterocyclic group, or X is a nitrogen-containing heterocyclic residue attached at a ring nitrogen atom; Y is a group having the formula ##STR2## wherein Q is selected from the residues: (a) --COOR.sup.4 or --CONR.sup.4 R.sup.5 where R.sup.4 is hydrogen, alkyl optionally interrupted by 1 or more oxygen atoms, alkenyl, cycloalkyl, aralkyl or aryl, and R.sup.5 is hydrogen or alkyl or R.sup.4 and R.sup.

Abstract: Dyestuffs of the general formula ##STR1## wherein A and B each represent a cyano, acyl or carbalkoxy group save that when A is cyano B cannot be cyano or carbalkoxy, or A and B form together with the carbon atom to which they are attached a carbocyclic or heterocyclic ring system, R.sub.1 is hydrogen, alkyl or alkoxy, R.sub.2 alkyl, R.sub.3, R.sub.4, R.sub.5 each are hydrogen, alkyl, carboxyalkyl, alkoxy-carbonyl-alkyl or aryl, or two of R.sub.3, R.sub.4 and R.sub.5 or all three R.sub.3, R.sub.4 and R.sub.5 may form together with the nitrogen atom to which they are bonded a ring system, Z is a linking group and X.sup..crclbar. an anion.The dyes can be bleached easily and they are suitable as antihalation or filter dyes in photographic materials.

Abstract: Light-sensitive photographic material which contains a non-light sensitive uv-filter layer comprising a compound of the formula ##STR1## wherein R is alkyl, sulphoalkyl, carboxyalkyl, alkaryl or aryl, X is --S--, --CH.sub.2 -- or --C(CH.sub.3).sub.2 --, T and Q are each an organic grouping or together complete a carbocyclic or heterocyclic ring, there being present in at least one of T and Q or in the ring which together they complete at least one electron withdrawing group.These compounds exhibit a very sharp cut-off point at about 400 nm.

Abstract: Light-sensitive photographic material which contains a non-light sensitive uv-filter layer comprising a compound of the general formula ##STR1## wherein R.sub.1 is alkyl or a group of the formula ##STR2## wherein R.sub.6 is alkylene and R.sub.7 and R.sub.8 are each alkyl or one of R.sub.7 and R.sub.8 can be hydrogen, R.sub.2 and R.sub.3 are each hydrogen or alkoxy, Z is oxygen or sulphur, Y is oxygen or sulphur or a group --NR.sub.5 --, wherein R.sub.5 is hydrogen or optionally substituted alkyl, aryl or carboxyalkyl, and R.sub.4 is hydrogen or optionally substituted alkyl, aryl or carboxyalkyl. These compounds exhibit a very sharp cut-off point at about 400 nm.

Abstract: Light-sensitive photographic material which contains as a uv-filter layer a non-light sensitive layer comprising a compound of the formula ##STR1## wherein W is the residue of an oxazolone, isoxazolone or pyrazolone ring, R.sub.1, R.sub.2 and R.sub.5 are each hydrogen or halogen or --OCOR.sub.10 wherein R.sub.10 is an optionally substituted alkyl or alkoxy, alkaryl or aryl, and R.sub.3 and R.sub.4 are each hydrogen or alkoxy.These compounds exhibit a very sharp cut-off point at about 400 nm.

Abstract: A photographic silver halide material is provided which comprises in at least one layer a solid dispersion of at least one water-insoluble methine dye of the formula ##STR1## wherein L and L' each represent an optionally substituted methine group, n is O, 1 or 2, Z represents the atoms necessary to complete an optionally substituted acidic carbocyclic or heterocyclic ring, Y represents the atoms necessary to complete an optionally substituted basic carbocyclic or heterocyclic ring, at least one of the rings Z and Y being substituted by a --COOH group or being substituted by a group which comprises a --COOH group. The solid dispersion of the dye is finely divided in the binder material of said layer, which is normally a filter or anti-halation layer. A marked increase of sharpness of the images obtained from photographic material containing in at least one layer the solid dyestuff dispersion can be observed.

Abstract: A photographic silver halide material is provided which comprises in at least one layer a solid dispersion of a water-insoluble dye of the formula ##STR1## wherein each of L, L' and L" are an optionally subsituted methine group, n is 0 or 1, Q is an optionally substituted aryl group or an optionally substituted heteroaromatic group, R.sub.1 represents a hydrogen atom or an optionally substituted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical or an optionally substituted amino group, R.sub.2 represents a hydrogen atom or a hydroxy, amino, --CN, --COOR.sup.1, --CONR.sup.1 R.sup.2 or --COR.sup.1 group or an optionally substituted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical, and R.sub.3 represents a --CN, --COOR.sup.3, --CONR.sup.3 R.sup.4, --SO.sub.3 H, --SO.sub.3.sup..crclbar. or --COR.sup.3 group, where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each independently represent a hydrogen atom or an optionally substituted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical, in a binder.

Abstract: Dyestuffs of the formula ##STR1## are provided wherein R.sub.1 is hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, amino or substituted amino, amido or substituted amido or hydroxyl, alkoxy, thioalkoxy or a carboxyl group or an ester thereof, R.sub.2 represents either --N.dbd. or a linking group .dbd.CH--(CH.dbd.CH).sub.n -where n is 0, 1 or 2 and R.sub.3 is an optionally substituted heteroaromatic ring which optionally may be benzannelated, an optionally substituted benzene ring, an optionally substituted 5- or 6-membered heterocyclic or carbocyclic ring, which contains at least one hydroxyl group and may optionally be benzannelated, or R.sub.