Patent GB-1508176-A (GB)
Title: Process for the hardening of photographic layers
IPC: G03C1/30
Filed: 1975-04-11
Abstract: 1508176 Hardening protein AGFAGEVAERT AG 11 April 1975 [11 April 1974] 14976/75 Heading C3H [Also in Division G2] In a process for the hardening of a photographic layer which contains protein the layer or layers to be hardened is or are coated with a composition which contains as its major constituents at least one quick-acting hardener which is a compound of any of the general Formulae I, II, R1-N=C=N-R2 (III) or IV and at least one polysaccharide which is a linear polymer in which either (1) at least one third of the monosaccharide units have a 1-2 linkage and the remaining monosaccharide units have a 1-4 linkage or (2) substantially all of the monosaccharide units have a 1-4 linkage and at least 50% of the hydroxyl groups of the monosaccharide units are acetylated or replaced by an OSO2Me group in which Me represents an alkali metal. In Formula I R1 represents an alkyl, aryl or aralkyl group, each of which may be substituted, R2 represents the same group as R1 or a double-bonded alkylene, arylene, aralkylene or alkyl-aryl-alkyl group any of which may be substituted and which is connected through its second bond to another carbamoyl ammonium group of the formula or R1 and R2 may together represent the atoms to complete an optionally substituted heterocyclic ring, R3 represents hydrogen, alkyl or the group -[A]alphain which A represents a vinyl group of a polymerized vinyl compound or of a copolymer with other copolymerisable monomers and a is an integer such that the molecular weight of the compound is greater than 1000, R4 is hydrogen or alkyl or if Z represents the atoms to complete a pyridinium ring, R4 represents one of the groups (i) -NR<6>-CO-R<7> in which R<6> is H or alkyl or 1 to 4 carbon atoms, R' is H, alkyl or -NR<8>R<9> in which R<9>, R<9> which may be the same or different are H or C1-4 alkyl; (ii) -CH2)m- NR<10>R<11> in which R<10> represents -COR<12>, R<11> is H or C1 to C4 alkyl, R<12> is H, C1 to C4 alkyl or NR<13>R<14> in which R<13> is alkyl or aryl and R<14> is H, alkyl or aryl, m = 1 to 3; (iii) -(CH2)n-CONR<15>R<16> in which R<15> is H, C1-4 alkyl or aryl, R<16> is H or C1-4 alkyl or R<15> and R<16> complete a 5- or 6-membered ring, n = 0 to 3; (iv) -(CH2)p-CH(R<17>)-Y-R<18> where R<17> is H or C1 +4 alkyl, optionally halogensubstituted, Y is -0- or -NR<19>, R<18> is H, alkyl or -COR<20> or -CONHR<21>, R<19>, R<20>, R<21>, are H or C1-4 alkyl, p = 2 or 3, R<5> is alkyl, aryl or aralkyl, but is absent in the N to which R<5> is attached carries a double bond in the ring formed by Z, Z represents the atoms that complete a substituted or unsubstituted 5- or 6- membered heterocyclic ring, X represents an anion. In hardeners of Formula II R1 is alkyl or aryl, R2 is alkyl or R5R6NCO- in which R5 is H or alkyl, R, is alkyl or R1 and R2 'together complete a heterocyclic system or R1 and R2 together complete a piperazine ring in which the second nitrogen atom establishes the link to a second similar molecular grouping, R3 is H, halogen, alkyl, hydroxyalkyl cyanogen, -NHCO alkyl, R4 is H or alkyl, X is an anion. In the carbodiimides of Formula III R1 and R2 are alkyl, alkoxyalkyl or aryl which may be substituted or R1 and R2 together complete a 5-membered heterocyclic ring which may be substituted or R1 is alkyl and R2 represents in which R3, R4 and R5 are alkyl or R4 and R5 together form a 6-membered heterocyclic ring containing one or two heteroatoms, R6 is H or alkyl and X is an anion. In the hardeners of Formula IV R1 and R2 represent an alkyl or substituted alkyl group and also when R3 represents 4, R2 represents R3 represents H, halogen, alkoxy or alkyl. Suitable polysaccharides are B1459 and B1973, described in U.S.A. Specifications 3,383,307, 3,516,983, 3,391,061 and 3,000,790, and cellulose sulphate of the formula The composition is applied as external layer to material to be hardened, which may be a final or intermediate layer. It can be formed in water alone or mixed with alcohols and acetone. Gelatin and other carboxy-containing polymers can be hardened. The hardener can be applied by suction casting, dipping or air-brush.