EP 0569074 B1 19981014 - Method of preparing an aqueous solid particle dispersion of a photographically useful compound
Title (en)
Method of preparing an aqueous solid particle dispersion of a photographically useful compound
Title (de)
Verfahren zur Herstellung einer wässrigen Dispersion von festen Teilchen einer photographisch verwendbaren Verbindung
Title (fr)
Procédé de préparation d'une dispersion aqueuse de particules solides d'un composé utilisable en photographie
Publication
Application
Priority
EP 92201228 A 19920504
Abstract (en)
[origin: EP0569074A1] A method of preparing of fine, stable, homogeneous and reproducible silica particle dispersions of a photographically useful compound, to be incorporated before or during the coating procedure into at least one hydrophilic layer of a photographic material on at least one side of a support comprising the steps of dissolving a non-watersoluble but alkali-soluble compound in an aqueous alkaline solution, if necessary with the help of an organic water soluble solvent; precipitating the said compound from said solution in the presence of colloidal silica sol , preferably in the further presence of a dispersing agent by lowering the pH of the solution; removing water-soluble salts formed by the precipitation and any organic solvent used and concentrating the dispersion either during or after the precipitation by dialysis or ultrafiltration or after precipitation by flocculation and decantation, followed by washing and further decantation.
IPC 1-7
IPC 8 full level
B01J 13/00 (2006.01); G03C 1/005 (2006.01); G03C 1/015 (2006.01); G03C 1/06 (2006.01); G03C 1/76 (2006.01); G03C 5/17 (2006.01); G03C 7/388 (2006.01)
CPC (source: EP)
G03C 1/005 (2013.01); G03C 5/17 (2013.01); G03C 7/388 (2013.01)
Designated contracting state (EPC)
BE DE FR GB NL
DOCDB simple family (publication)
EP 0569074 A1 19931110; EP 0569074 B1 19981014; DE 69321514 D1 19981119; DE 69321514 T2 19990527; JP 3222266 B2 20011022; JP H06194763 A 19940715
DOCDB simple family (application)
EP 93201135 A 19930420; DE 69321514 T 19930420; JP 12833993 A 19930430