Patent GB-1473804-A (GB)
Title: Supersensitised silver halide photographic emulsions
IPC: G03C1/29
Filed: 1975-07-28
Abstract: 1473804 Supersensitized photographic material FUJI PHOTO FILM CO Ltd 28 July 1975 [26 July 1974] 31582/75 Heading G2C A supersensitized silver halide emulsion comprises a sensitizing dye of the general Formula: wherein Z<SP>1</SP> and Z<SP>2</SP> each represents the atoms required for completing an optionally substituted benzimidazole, oxazole, benzoxazole, naphthoxazole, thiazole, benzothiazole, naphthothiazole, selenazole, benzoselenazole or naphthoselenazole nucleus, provided that both Z<SP>1</SP> and Z<SP>2</SP> do not simultaneously represent an oxazole, benzoxazole or naphthoxazole nucleus; R<SP>1</SP> and R<SP>2</SP> each represents an optionally substituted aliphatic group the carbon chain of which may be interrupted with an oxygen or sulphur atom; R represents a hydrogen atom, an alkyl group or an aralkyl group; X<SP>1#</SP> represents an anion; and m is 0 or 1, with m being 0 when the dye forms an intramolecular salt; and a sensitizing dye of the general Formula: wherein Z<SP>3</SP> and Z<SP>4</SP> each represents the atoms required for completing an optionally substituted pyrroline, pyridine, indolenine, benzimidazole, oxazole, benzoxazole, naphthoxazole, thiazoline, thiazole, benzothiazole, naphthothiazole, selenazole, benzoselenazole or naphthoselenazole nucleus; R<SP>3</SP> and R<SP>4</SP> each represents an aliphatic group the carbon chain of which may be interrupted with an oxygen or sulphur atom, and at least one of R<SP>3</SP> and R<SP>4</SP> represents an aliphatic group having as substituent a hydroxy, carboxy or sulpho group and optionally other substituents; X<SP>2#</SP> represents an anion; and n is 0 or 1, with n being 0 when the dye forms an intramolecular salt. The emulsion may also comprise an oxacarbocyanine dye of the general Formula: wherein Y<SP>1</SP> and Y<SP>2</SP> each represents the atoms required for forming a benzoxazole or naphtho [1, 2-d]-oxazole nucleus, optionally substituted with one or more substituents which do not reduce the sensitivity; R<SP>16</SP> and R<SP>17</SP> each represents an aliphatic group; R<SP>18</SP> represents a lower alkyl group or an aryl group; and X<SP>3</SP> and p have the same meanings as X<SP>1</SP> and m in the general Formula 1; or a merocyanine dye of the general Formula: wherein Y<SP>3</SP> represents the atoms required for forming an optionally substituted oxazole, benzoxazole, naphtho [1, 2-d]-oxazole, thiazole, benzothiazole, naphtho[1,2-d] thiazole, selenazole, naphtho[1,2-d] selenazole, thiazoline or benzimidazole nucleus; Y<SP>4</SP> represents the atoms required for completing a rhodanine or hydantoin nucleus; R<SP>19</SP> represents an optionally substituted aliphatic group as described for R<SP>1</SP>, R<SP>2</SP>, R<SP>3</SP> and R<SP>4</SP> in the general Formula I and II; and R<SP>20</SP> represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a methoxy group, an ethoxy group, a phenyl group, a benzyl group, a phenethyl group or a carboxyphenyl group. Each of dyes I and II may be present in an amount of 1 x 10<SP>-5</SP> to 0.0025 mole per mole of silver halide. The molar ratio of dyes I and II may be 1:10 to 10:1. The emulsion may be panchromatically or orthochromatically sensitized. The emulsion may be lith-type.