Abstract: Substituted hydroquinone compounds of the formula ##STR1## wherein R.sub.1 to R.sub.4 are hydrogen or alkyl and Z is an aromatic ring or a group of the formula --X--Y--X--, wherein X is an aromatic ring and Y is an electron withdrawing group, are incorporated as developers into photographic materials. These materials are suitable for activation processings.

Abstract: Substituted hydroquinone compounds of the formula ##STR1## wherein R.sub.1 to R.sub.4 are hydrogen or alkyl and Z is an aromatic ring or a group of the formula --X--Y--X--, wherein X is an aromatic ring and Y is an electron withdrawing group, are incorporated as developers into photographic materials. These materials are suitable for activation processings.

Abstract: A photographic dye diffusion transfer process is provided which operates by imagwise release of a dye.The dye diffuses to a receiving layer and is mordanted there to give a dye image. The dyes are released from a compound of the formula D--E--F--BAL by reductive cleavage.D is a group which contains the residue of diffusible dye, BAL is a ballasting group which renders the compound containing it substantive to the layer in which it is present, D and E being joined by any type of chemical bond and E and F represent a single or double bond system which links D and BAL and which has a reduction potential above -200 mV measured against a standard hydrogen electrode at a pH of less than 3 and which bond can be reductively cleaved at a pH of less than 3 by a reducing agent which is able to act as a pH below 3.

Abstract: Novel azo compounds and their preparation are provided. These compounds have the general formula ##STR1## wherein X is N or CR.sub.4 where R.sub.4 is a hydrogen atom or an optionally substituted alkyl or aryl group, Y is S.sup..sym., N.sup..sym. R.sub.5, O.sup..sym. or N where R.sub.5 is an optionally substituted alkyl or aryl group, R.sub.1 is an optionally substituted alkyl or aryl group, R.sub.1 is a substituted aromatic or heterocyclic group containing a ballasting group, R.sub.2 and R.sub.3 are each hydrogen or alkyl groups having 1 to 4 carbon atoms, or R.sub.2 and R.sub.3 together with the nitrogen atom complete a heterocyclic ring, or one of R.sub.2 or R.sub.3 can be hydrogen and the other of R.sub.2 or R.sub.3 can be aryl. There may be further substitution in either of the benz rings and these rings may be benzannelated. These azo compounds are useful in the photographic field especially in the photographic dye diffusion transfer process for the production of photographic images.

Abstract: Orange colored magenta color couplers of the general formula ##STR1## are provided, in which R is optionally substituted alkyl, aralkyl, aryl or a heterocyclic group, X is optionally substituted aryl, Y is optionally substituted acyl-amino, aroyl amino or aryl amino and Z represents further optional substituents of the phenyl ring. Preferably Y also contains a ballasting group, which is a long claim alkyl group having 10 to 24 carbon atoms in the chain.

Abstract: A photographic dye diffusion transfer process is provided which operates by imagwise release of a dye.The dye diffuses to a receiving layer and is mordanted there to give a dye image. The dyes are released from a compound of the formula D--E--F--BAL by reductive cleavage.D is a group which contains the residue of diffusible dye, BAL is a ballasting group which renders the compound containing it substantive to the layer in which it is present, D and E being joined by any type of chemical bond and E and F represent a single or double bond system which links D and BAL and which has a reduction potential above -200 mV measured against a standard hydrogen electrode at a pH of less than 3 and which bond can be reductively cleaved at a pH of less than 3 by a reducing agent which is able to act at a pH below 3.

Abstract: Novel azo(hydrazo)-anthraquinone compounds and their preparation are provided.These compounds are of the general formula ##STR1## where R is hydrogen or at least one substituent, T.sub.1 is hydrogen, an hydroxy or alkoxy group or an amino or substituted amino group, R.sub.1 is hydrogen or halogen, an alkoxy, an amino or substituted amino group, an aryl or substituted aryl group, or a group conferring solubility in water and R.sub.2 is a group which comprises an azo linkage and a ballasting group or is a group which completes the hydrazo link and which comprises a ballasting group. The new compounds are useful in the photographic field, especially in the photographic dye diffusion transfer process for the production of photographic images.