COBALT (II) AND MANGANESE (II) CHELATES AS PHOTOGRAPHIC EMULSION ANTIFOGGANTS

摘要

1,214,982. Photographic anti-foggants. GEVAERT-AGFA N.V. April 19, 1968 [May 18, 1967; Oct.19, 1967], Nos.23048/67 and 47731/67. Heading G2C. Silver halide emulsions are developed in the presence of at least one Co (II) or Mn (II) chelate of a polyamino - polycarboxylic acid or watersoluble salt thereof, which acts as an anti-foggant/ stabilizer. Preferably the chelate is derived from an acid of formula: - (in which L is optionally substituted alkylene or cycloalkylene or alkylene interrupted by one or more hetero atoms, X is 0-2, R is optionally substituted C 1-5 lower alkylene, and R 1 and R 2 are each optionally substituted C 1 -5 alkyl or aryl groups). The chelate is preferably added to the silver halide layer in an amount of 0À1-20g. per mole of silver halide, or to a non-photo-sensitive layer, e.g. gelatin anti-stress overcoat layer, in an amount of 10-1000 mg. m SP2/SP , and may be used in conjunction with a conventional hydroxy azaindolizine stabilizer and an onium or poly (alkylene oxide) development accelerator.