Process for the preparation of high chloride tabular grain emulsions (II)
US5178997A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 20, 1991 |
| Grant date | Jan 12, 1993 |
| Priority date | — |
| Expiry date | Sep 20, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2200/44
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process of preparing a radiation sensitive high chloride high aspect ratio tabular grain emulsion is disclosed wherein silver ion is introduced into a gelatino-peptizer dispersing medium containing a stoichiometric excess of chloride ions a chloride ion concentration of less than 0.5 molar and a grain growth modifier of the formula: ##STR1## where Z.sup.2 is --C(R.sup.2).dbd. or --N.dbd.; PA1 Z.sup.3 is --C(R.sup.3).dbd. or --N.dbd.; PA1 Z.sup.4 is --C(R.sup.4).dbd. or --N.dbd.; PA1 Z.sup.5 is --C(R.sup.5).dbd. or --N.dbd.; PA1 Z.sup.6 is --C(R.sup.6).dbd. or --N.dbd.; PA1 with the proviso that no more than one of Z.sup.4, Z.sup.5 and Z.sup.6 is --N.dbd.; PA1 R.sup.2 is H, NH.sub.2 or CH.sub.3 ; PA1 R.sup.3, and R.sup.4 and R.sup.5 are independently selected, R.sup.3 and R.sup.5 being hydrogen, hydroxy, halogen, amino or hydrocarbon and R.sup.4 being hydrogen, halogen or hydrocarbon, each hydrocarbon moiety containing from 1 to 7 carbon atoms; and PA1 R.sup.6 is H or NH.sub.2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.