| abstract |
(57) Abstract: To provide a silver halide recording material in which grains are improved without lowering the sensitivity. The grain / sensitivity ratio of photographic silver halide materials can be improved by adding to one of its layers a compound of formula I. The material also exhibits a smaller increase in fog when stored. Embedded image In the formula, Y 1 , Y 2 and Y 3 each represent one of the following residues, and R 1 to R 34 mean H, alkyl or aryl; two residues located on the same N atom (R 1 to R 34 ) contain at least one N atom and optionally further heteroatoms. Can have 5-, 6- or larger rings which can have; 2 located on adjacent N atoms One residue (R 1 -R 34 ) can complete a ring containing both an N atom and at least one P atom, and X − is an anion necessary to balance the charge, such as Cl − , It means Br − or tosylate (TosO − ). |