Agfa-gevaert Ag

Agfa-gevaert

Agfa Gevaert Nv

Asfa-gevaert N.v.

Lothar Endres

Peter Bell

Thomas Stetzer

Lothar Rosenhahn

Rainer Scheerer

Lydia Simon

Hans-Ulrich Borst

Ralf Buscher

Klaus Wagner

Otto Lapp

Beate Weber

Hans Hlschlager

Reinhart Matejec

Franz Moll

Johannes Willsau

Harald Von Rintelen

Manfred Becker

G&uuml;nter Helling

Ralf B&uuml;scher

Detlef Brennecke

Ralf B Uscher

Heinz Sch&uuml;tz

Detlev Kapitza

Color photographic silver halide material

Polymer

A color photographic film having a support, 2 or 3 red-sensitive, cyan-coupling silver halide emulsion layers, 2 or 3 green-sensitive, magenta-coupling silver halide emulsion layers, 2 or 3 blue-sensitive, yellow-coupling silver halide emulsion layers, conventional interlayers and protective layers together with a yellow filter layer arranged closer to the support than the blue-sensitive layers, wherein at least one green-sensitive silver halide emulsion layer is arranged further away from the support than all the other photosensitive layers, exhibits improved sharpness without color distortion if at least 50% of the projected surface area of the silver halide emulsion of the green-sensitive silver halide emulsion layer, of which there is at least one, consists of tabular silver halide grains having an aspect ratio of at least 3.

Color photographic film

A colour photographic material in which a package of layers is provided which consists, in the stated sequence, of (a) a silver halide-free layer containing colour coupler, (b) a layer containing silver halide and (c) a silver halide-free layer containing colour coupler, wherein at least one of layers (a) and (c) consists to an extent of at least 20 vol. % of a synthetic polymer, is distinguished by an improved grain/sensitivity ratio.

Color photographic material

A color photographic silver halide material having at least two blue-sensitive, yellow coupler containing silver halide emulsion layers, at least two green-sensitive, magenta coupler containing silver halide emulsion layers and at least two red-sensitive, cyan coupler containing silver halide emulsion layers together with conventional interlayers and protective layers, wherein photosensitive layers of identical color sensitivity differ with regard to the photographic sensitivity thereof and the more highly sensitive layers are arranged further away from the support than the less sensitive layers of identical color sensitivity, which material contains, in a layer which is arranged further from the support than the most highly sensitive, blue-sensitive layer, both at least one yellow coupler and at least one magenta or cyan coupler, is distinguished by improved grain and sensitivity combined with very good color reproduction.

A silver halide having at least two halides of differing atomic numbers may successfully be produced with a more uniform halide distribution within certain zones or throughout the entire volume of the individual grain and from grain to grain, if a portion or the entire quantity of the halide of the higher atomic number is dissolved in an aqueous silver salt solution and the resulting solution is introduced at any stage into the emulsion preparation process.

Process for the production of silver halide emulsions

A colour photographic silver halide material with a support, at least one red-sensitive silver halide emulsion layer containing at least one cyan coupler, at least one green-sensitive silver halide emulsion layer containing at least one magenta coupler, at least one blue-sensitive silver halide emulsion layer containing at least one yellow coupler, at least one interlayer Z-1 beneath the lowermost red-sensitive silver halide emulsion layer and/or at least one interlayer Z-2 beneath the lowermost green-sensitive silver halide emulsion layer, in which Z-1 and/or Z-2 contains a silver halide emulsion which contains tabular grains with an aspect ratio of&gt;2, an average diameter of a sphere of equal volume of.gtoreq.0.3 .mu.m and a diameter of a circle of equal projected surface area of the tabular grains of at least 0.3 .mu.m, is distinguished by improved red and/or green sensitivity.

Emulsions having an improved sensitivity/grain ratio are obtained when a silver halide emulsion containing up to 20 mol % of AgI is prepared by the precipitation of a silver halide emulsion A containing up to 100 mol % of AgI and the addition of a silver halide emulsion B which contains up to 40 mol % of AgI, has an average grain size of at most 0.25 .mu.m and is always more soluble in aqueous gelatine solution than emulsion A either due to its grain size or due to its iodide content, this being carried out in the presence of at least two compounds selected from imidazole, histidine (.alpha.-amino-.beta.-imidazolyl-(5)-propionic acid) and other monocyclic, 5- or 6-membered heterocyclic compounds which have at least one ring nitrogen atom, are free from SH groups and form sparingly soluble silver salts in weak acid to neutral aqueous solutions, which salts redissolve at pH&gt;9 when ammonia is added, one of the at least two compounds being imidazole or histidine and at least one other compound being a compound other than imidazole or histidine.

Process for the preparation of silver halide emulsions

Photographic recording materials containing a silver halide emulsion in which the grains have zones of differing iodide content provide improved sensitometric results.

Photographic recording material

Silver halide emulsions are prepared by precipitating a silver halide emulsion I on a more sparingly soluble silver halide emulsion II in the presence of a silver halide solvent wherein the emulsion I has been prepared in the presence of a compound inhibiting grain growth.

Process for the preparation of silver halide emulsions, photographic

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Bergisch Gladbach, Germany

Lothar Endres