Agfa Gevaert Nv

Henri Depoorter

Raymond Gerard Lemahieu

Felix J Moelants

Willy Joseph Vanassche

Jozef Aime Dierckx

Emiel Alexander Hofman

Marcel Jan Libeer

Jozef Remy Schellekens

Gerrit Godfried Van Mierlo

For absorbing light of the whole visible spectral region in a silver halide emulsion layer or in an antihalation layer of a photographic material it suffices to use a 2-pyrazolin-5-one pentamethine oxonol dye corresponding to the formula: ##STR1## wherein R is a C.sub.1 -C.sub.5 alkyl group. The dyes are used in dispersed form in at least one light-sensitive silver halide emulsion layer or in an antihalation layer.

Photographic silver halide materials containing light-absorbing dyes

Light-absorbing fluorine-containing 2-pyrazolin-5-one methine oxonol dyes corresponding to the formula ##STR1## wherein R is C.sub.1 -C.sub.5 alkyl, aryl, alkoxycarbonyl, carboxy, or carbamoyl, and n is 0, 1, or 2. The dyes can be used in light-sensitive silver halide materials in an antihalation layer, in a filter layer or as screening dyes in a light-sensitive layer. They manifest great stability while in dissolved state within a very large pH-range and they are decolorized easily in one of the processing baths. They are prepared by joining 2 appropriately substituted pyrazolone rings in 4-position by 1 methine group through reaction with an ester of an orthocarboxylic acid or by a tri- or pentamethine group through reaction with .beta.-anilinoacrolein anil HCl or glutaconic dialdehyde dianil HCl respectively.

Photographic materials containing light absorbing methine dyes

Novel antihalation layer(s) for use in a light-sensitive silver halide element and comprising a 5-pyrazolone-monomethine oxonol of formula I and a 5-pyrazolone-pentamethine oxonol of formula II : ##STR1## wherein: EACH OF R.sup.1 and R.sup.3 represents an alkyl group or an aryl group,

Light-absorbing dyes for silver halide material

Dyes are described corresponding to the following formula for use as light-absorbing dyes in silver halide photographic material: ##STR1## wherein: Z represents the atoms necessary to form a barbituric acid nucleus (p=1 or 2), a phenyl group (p=0 or 1) or a pyrrole ring (p=0)

Light-absorbing dye for use in photography

A direct-positive photographic element is described which comprises a support and a spectrally-sensitized light-sensitive silver halide emulsion layer containing fogged silver halide grains wherein the said emulsion is spectrally sensitized by means of a dye containing a pyrrolo[ 2,1-b]thiazole nucleus which may be substituted and carry one or more fused-on rings, the said nucleus being linked by the 5- or 7-carbon atom thereof, directly or through a dimethine chain to another nitrogen containing heterocycle.

Fogged, direct-positive silver halide emulsion optically sensitized with

Novel dyes are described for sepctrally sensitizing direct-positive silver halide emulsions comprising fogged silver halide grains. The dyes correspond to the formula: ##SPC1## Wherein:

Spectral sensitization of direct-positive silver halide emulsions

The invention relates to a new class of pyrrolobenzimidazole, benzimidazoloisoquinoline and dipyrodinobenzodiimidazole in cyanine sensitizing dyes derived therefrom and their use in silver halide emulsions, and to methods for preparation of such new dyes.

Growing community of inventors

Mortsel, Belgium

Henri Depoorter