Process for the hardening of photographic layers utilizing fast acting hardener and polysaccharide

Claim 1

The process of hardening a photographic material comprising at least one layer comprised of a light-sensitive silver halide emulsion and at least one layer containing a binder comprised of gelatin which comprises the step of applying to at least one layer containing gelatin a coating of a composition consisting essentially of from 5 to 500 g per 1000 ml of water of a quick acting hardener which acts by activating carboxyl groups present in the gelatin selected from the group consisting of (a) a compound of the following general formula ##STR91## wherein R 1 =an unsubstituted or substituted alkyl, aryl or aralkyl group, R 2 =either (1) an unsubstituted or substituted alkyl, aryl or aralkyl group and has the same meaning as R 1 or (2) an alkyl, aryl, aralkyl or alkyl-aryl-alkyl group which is substituted with another carbamoyl ammonium group of the formula ##STR92## or R 1 and R 2 together form the atoms required for completing a substituted or unsubstituted heterocyclic ring; R 3 =hydrogen, alkyl or the group A wherein A denotes a vinyl group of a polymerisable vinyl compound or of a copolymer with other copolymerisable monomers and α represents a number such that the molecular weight of the compound is greater than 1000, R 4 =hydrogen, or alkyl or, where Z denotes the atomic group required for completing a pyridinium ring and R 3 is absent, R 4 denotes a formylamino, acrylamino ureido group substituted or unsubstituted on the nitrogen atom, an alkyl group substituted with acylamino or ureido groups which in turn may be substituted, a substituted or unsubstituted amido group, or alkyl which is substituted with an optionally substituted amido group, a straight chain or branched chain alkyl substituted with hydroxyl, alkyl, formyloxy, acyloxy or optionally substituted carbamoyloxy, a straight chain or branched chain alkyl substituted with amino, alkylamino, formylamino, acylamino or a ureido group; R 5 =alkyl, aryl or aralkyl but R 5 is absent if the nitrogen atom to which R 5 is attached carries a double bond in the heterocyclic aromatic ring formed by Z, Z=the group of atoms required for completing a 5-membered or 6-membered substituted or unsubstituted heterocyclic aromatic ring, including a condensed ring system, which group may include one or more additional heteroatoms, and X=an anion, (b) a carbamoyloxy pyridinium of the general formula ##STR93## wherein R 1 =alkyl or aryl, R 2 =alkyl or the group ##STR94## R 5 denotes hydrogen or alkyl and R 6 denotes alkyl, R 1 and R 2 together represent the atoms required for completing a heterocyclic ring system such as a pyrrolidine-, morpholine-, piperidine-, perhydrozepine, 1,2,3,4-tetrahydroquinoline or imidazolidine-2-one ring or R 1 and R 2 together represent the atoms required for completing a piperazine ring in which the second nitrogen atom establishes the connection to a second, similar carbamoyloxy pyridinium molecular grouping corresponding to the general formula, ##STR95## R 3 =hydrogen, halogen, alkyl, hydroxyalkyl, cyanogen, CONH or ##STR96## alkyl R 4 =hydrogen or alkyl and X=anion, (c) a carbodiimide of the general formula R.sub.1 --N═C═N--R.sub.2 wherein R 1 and R 2 =identical or different alkyl, alkoxyalkyl or optionally substituted aryl groups or a 5-membered optionally substituted heterocyclic ring or R 1 =alkyl containing 1-5 C-atoms and R 2 =the group ##STR97## wherein R 3 =alkyl containing 1-5 C-atoms, R 4 and R 5 =alkyl containing 1-3 C-atoms or R 4 and R 5 together form a 6-membered heterocyclic ring containing one or two hetero atoms, R 6 =H or a lower alkyl and X=an anion, and (d) a dihydroquinoline of the general formula ##STR98## wherein R 1 =unsubstituted or substituted alkyl, R 2 =unsubstituted or substituted alkyl or aralkyl or, when R 3 =H, R 2 denotes the group ##STR99## R 3 =hydrogen, halogen, alkyl, alkoxy and 1 to 20 g of a polysaccharide which being free of carboxyl groups does not react with said quick-acting hardener and which is a linear polymer in which either (1) at least one third of the monosaccharide units have a 1-2-bond and the remaining monosaccharide units have a 1-4-bond or (2) substantially all the monosaccharide units have a 1-4 bond and at least 50% of the hydroxyl group of the monosaccharide units are acetylated or replaced by an OSO 3 Me group, wherein Me denotes an alkali metal whereby the carboxyl activity of said hardener has an onset subsequent to the application of the composition to the gelatin containing layer.