Ciba-geigy Ag

Other

Ilford Limited

Norman A Smith

Rainer Kitzing

Stephen R Postle

William E Long

John Douglas Ballantine

Terence C Webb

Kenneth M McCombe

Martin C Grossel

Compounds of the formula ##STR1## wherein L is a direct bond or consists of a chain of carbon atoms or of a divalent ring system, R.sub.1 to R.sub.4 are hydrogen or alkyl, R.sub.5 or R.sub.6 are hydrogen, alkyl or aryl, or R.sub.5 together with R.sub.6 complete a ring system, and R.sub.7 is hydrogen or a group of the formula ##STR2## wherein L, R.sub.5 and R.sub.6 are as defined. These compounds are useful developing agents for activation processing.

Protected developing agents

Hydroquinones of the formula ##STR1## wherein X is the residue of a 5- or 6-membered ring, R.sub.1 is hydrogen, alkyl or aryl, R.sub.1,R.sub.3, R.sub.4 and R.sub.5 are hydrogen or alkyl and R.sub.6 is hydrogen or a group of the formula ##STR2## wherein X and R.sub.1 are as defined above, are of use as protected developing agents in photographic silver halide material.

Substituted hydroquinones

Photographic material which comprises in at least one silver halide emulsion layer or a layer or layers adjacent thereto at least one substituted hydroquinone compound of the formula ##STR1## where R is hydrogen or optionally substituted alkyl, aryl or a heterocyclic group, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each hydrogen, halogen or optionally substituted alkyl,

Photographic material

A vinylsulphone compound of the formula ##STR1## is provided. This compound is useful as cross-linking agent for hydrophilic colloids, especially for gelatin which is in the form of layers of photographic materials.

Vinylsulphone hardener

New vinyl compounds of the general formula ##STR1## are provided, wherein A is --CO-- or --SO.sub.2 --, v is 0 or 1, w is 0 or an integer of 1 to 6, x is 0 or 1, y is 2 to 6 and z is 1 or 2, at least one of w and x x being a positive integer. The vinyl compounds are useful as cross-linking agents for hydrophylic colloids, especially for gelatine in gelatino silver halide emulsion layers and other layers in photographic material.

Sulfur containing vinyl amide cross-linking agents

Vinylsulphone compounds of the general formula

Vinylsulphone hardeners

Bis 1,4-(b-vinylso.sub.2 -propionyl)-piperazine

The present invention relates to a process for crosslinking hydrophilic materials by means of a triazine compound of the formula ##STR1## The process is preferably used for crosslinking gelatin in photographic material.

Process for crosslinking hydrophilic colloids with triazine compounds

The present invention relates to a process for crosslinking hydrophilic colloids, preferably gelatine and most preferably gelatine present in a photographic material. A 1,3,5-triazine compound containing an NC--N.sup.- -- substituent bound to the triazine ring is incorporated into the hydrophilic colloid as a crosslinking agent.

Process for crosslinking hydrophilic colloids

The present invention relates to the production of hardened gelatin layers by means of quaternary carbamoyl pyridinium compounds. Preferably this method is used for the hardening of silver halide photographic material.

Production of hardened gelatin layers by the addition of quaternary

This invention relates to the hardening of gelatin layers. The gelatin is heated with an aqueous solution of a 2-halogeno pyridinium compound.

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Hornchurch, United Kingdom

Norman A Smith