EP 0645022 B1 19980506 - PROCESSES OF PREPARING TABULAR GRAIN EMULSIONS
Title (en)
PROCESSES OF PREPARING TABULAR GRAIN EMULSIONS
Title (de)
VERFAHREN ZUR HERSTELLUNG VON TAFELKORNEMULSIONEN
Title (fr)
PROCEDES DE PREPARATION D'EMULSIONS A GRAINS TABULAIRES
Publication
Application
Priority
US 9302618 W 19930322
Abstract (en)
[origin: WO9422051A1] A process is disclosed of preparing silver halide emulsions containing tabular grains bounded by [100] major faces comprised of the steps of (1) introducing silver and halide salts into a dispersing medium and (2) maintaining conditions within the dispersing medium that promote the formation of tabular grains bounded by [100] major faces. The process is characterized in that of the tabular grains bounded by [100] major faces a portion accounting for 50 percent of total grain projected area selected on the criteria of adjacent major face edge ratios of less than 10 and thicknesses of less than 0.3 mu m internally at their nucleation site contain iodide and at least 50 mole percent chloride, at least the selected portion of the tabular grains being formed ty nucleation in a continuous double jet reaction in the presence of iodide with chloride accounting for at least 50 mole percent of the halide present in the dispersing medium and the pC1 of the dispersing medium being maintained in the range of from 0.5 to 3.5. Following nucleation tabular grain growth is undertaken in a reaction vessel which receives emulsion from the continuous double jet reactor until the tabular grains having a thickness of less than 0.3 mu m exhibit achieve a selected average aspect ratio.
IPC 1-7
IPC 8 full level
G03C 1/015 (2006.01); G03C 1/005 (2006.01); G03C 1/035 (2006.01); G03C 1/047 (2006.01)
CPC (source: EP)
G03C 1/0053 (2013.01); G03C 1/015 (2013.01); G03C 1/047 (2013.01); G03C 1/07 (2013.01); G03C 2001/0055 (2013.01); G03C 2001/0151 (2013.01); G03C 2001/0156 (2013.01); G03C 2001/03558 (2013.01); G03C 2001/0478 (2013.01); G03C 2200/01 (2013.01); G03C 2200/43 (2013.01); G03C 2200/44 (2013.01)
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
WO 9422051 A1 19940929; DE 69318405 D1 19980610; DE 69318405 T2 19981217; EP 0645022 A1 19950329; EP 0645022 B1 19980506; JP 3193381 B2 20010730; JP H07507646 A 19950824
DOCDB simple family (application)
US 9302618 W 19930322; DE 69318405 T 19930322; EP 93907632 A 19930322; JP 52097294 A 19930322