The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 06, 2003
Filed:
Jul. 11, 2001
Kathy Elst, Kessel, BE;
Ilse Mans, Herenthout, BE;
Agfa-Gevaert, Mortsel, BE;
Abstract
A method has been described for preparing an ultrathin tabular grain emulsion rich in silver bromide, having {111} major faces, wherein tabular grains having a thickness of less than 0.08 &mgr;m exhibit an average aspect ratio of more than 5:1 and account for at least 75% by number of hexagonal grains and a coefficient of variation on average equivalent surface area of less than 0.50. The process is characterized in that during formation, (a) pH is maintained from 0.8 to 10; (b) a gelatino-peptizer is present in a concentration of 0 to 50 g per liter of dispersing medium, and (c) pBr having a value of at least 1.8 is maintained during grain nucleation and pBr is maintained at less than 2.4 during growth provided that a gelatin peptizer which is free from calcium ions and has a methionine content of less than 30 micromoles per gram of gelatino-peptizer is present.