HIGH-CHLORIDE FOLDING TYPE PLANAR-PARTICLE EMULATION AND PREPARATION THEREOF

摘要

PURPOSE: To obtain a new photographic emulsion and its preparation method to obtain a planer particle emulsion having high chloride content which shows high stability in the particle shape. CONSTITUTION: This invention provides a preparation method of an emulsion comprising a dispersion medium and folded planer particles 1 containing at least 95mol% chloride based on the whole silver amt. In this method, the chloride ion concn. of the dispersion medium is kept at least 0.5mol concn. during the particle nucleus is formed, and the pH of the dispersion medium is kept to 1 to 8 during the particle is grown. The effective concn. of 2-hydroaminoazine or xanthinoid shape improving agent is maintained to 5×10<-5> to 2×10<-2> mmol.