| abstract |
Colour photographic silver halide material which contains in at least one coupler containing silver halide emulsion layer or in a layer adjacent thereton (a) a hydroquinone of the formulan wherein p is 1 or 2 and q is o or 1, provided that p + q is 1 or 2, R is a radical of the formulan wherein q is selected from the residues (1) -COZR 4 , wherein Z is O or NR 5 , and R 4 is hydrogen, alkyl optionally interrupted by oxygen, cycloalkyl, alkenyl, aryl, aralkyl or a heterocyclic ring, and R s is hydrogen or alkyl or together with R 4 and the nitrogen atom to which they are bonded form a heterocyclic ring, (2) -OX, wherein X is R s or-COR 7 , wherein R 7 is hydrogen, alkyl, cycloalkyl, alkenyl, aryl or aralkyl, (3) -NR 8 R 9 , wherein R 8 is hydrogen or alkyl, and R 9 is hydrogen, alkyl or -COR 7 , or R 8 and R 9 together with the nitrogen atom to which they are bonded form a ring, (4) -P(O)(OR' 10 [O] x R' 11 ), wherein x is 0 or 1, and if x is 1, r', o and R' 11 are hydrogen or alkyl orform together an alkylene chain, and if x is 0 R' 10 is alkyl, (5) -SO 2 NR 5 R 6 , wherein R s and R 6 are hydrogen or alkyl, or (6) cyano, n is 1 to 20, k is 1 or 2, R 2 and R 3 are alkyl and if Q is CO 2 R 4 , either R 2 or R 3 is optionally substituted by -CO 2 R 4 , or R 2 and R 3 form together an alkylene chain, and R 1 is alkyl or a group of the formulan or (b) a salt thereof, has an improved stability to light. |