Eastman-kodak Company

Douglas L Oehlbeck

Richard L Daubendiek

Joseph G Lighthouse

Michael W Orem

Jon N Eikenberry

Timothy R Gersey

Barry M Brown

Barbara J Fisher

Jeffrey S Baugher

Marian S Henry

John R Tinney

Alton L Chitty

Karen L Pond

David Lawrence Benzing

Ward K Darron

Robert Alan Zabelny

A process of preparing a high bromide tabular grain emulsion comprising a dispersion medium and silver halide grains including tabular grains having &lcub;111&rcub; major faces and an aspect ratio of at least 2, which contain greater than 50 mole percent bromide, based on silver, and which account for greater than 50 percent of total grain projected area, where such tabular grains have an average aspect ratio of at least 5, the process comprising (i) in a grain nucleation step creating in a dispersing medium tabular silver halide grain nuclei containing parallel twin planes and (ii) in a grain growth step subsequently growing the tabular grain nuclei into tabular grains in a silver halide reaction vessel by adding a silver ion source and a halide ion source to the reaction vessel and precipitating silver halide onto the tabular grain nuclei, wherein thiocyanate ion is introduced into the silver halide reaction vessel prior to the addition of at least the final 10 mole percent of the total silver added to the reaction vessel, and further wherein the introduced thiocyanate ion concentration is at most 0.4 mole %, based on the total silver added to the reaction vessel. Use of thiocyanate during grain precipitation result in increased aspect ratio without degrading morphological purity.

Method for making tabular grain silver halide emulsion

The invention relates to a solution for forming silver halide emulsions comprising water, a gelatin containing less than 30 micromoles of methionine per gram of gelatin, and at least one antifoamant of Formula I

Siloxane nonagglomerating antifoamants

The invention generally provides the apparatus for liquid delivery comprising a syringe pump for reactant delivery and a syringe pump for liquid chase material delivery.

Syringe pump apparatus for remote delivery of reactants

The invention relates to a solution for forming silver halide emulsions comprising water, a gelatin containing less than 30 micromoles of methionine per gram of gelatin, and at least one antifoamant selected from the group consisting of RCO.sub.2 (CH.sub.2 CH.sub.2 O).sub.x OCR (I) wherein RC and CR represent the carbon chain in carboxylic acids with chain lengths of predominantly 12-18 carbon atoms, x has a mean value of 4 to 5 from a mixture with a distribution of values between 2 and 7, and (H.sub.3 CSi) �(OSi (CH.sub.3).sub.2).sub.d O-- (CH.sub.2 CH.sub.2 CH.sub.2 O--).sub.n C.sub.4 H.sub.9 !.sub.3 (II) wherein the molecular weight is 2500 to 3500 and d and n have average values of less than 15.

Nonagglomerating antifoamants

A method for the reproducible production of nonuniform distributions of polymolecular association clusters, each of the clusters comprising a plurality of a species A in association with a single species B, is disclosed. Species A is preferably a photographic dye and Species B is preferably a silver halide particle. The method comprises: (a) mixing a suspension of particles of species B in a vessel; (b) flowing a portion of the suspension through an isolated reaction zone; (c) introducing species A into the isolated reaction zone; and (d) returning the portion of the suspension including the introduced species A to the vessel. In another aspect, the invention relates to an apparatus for carrying out the foregoing process.

Process and apparatus for reproducible production of non-uniform product

A fluid (liquid or gas) distributing apparatus comprises a series of annular conduits positioned concentrically and close to a region for mixing or performing a reaction. Each annular conduit has a plurality of orifices associated therewith which are spaced circumferentially and symmetrically proximate to the region and each orifice is positioned to deliver a liquid stream to the region. A feed line connects with a plurality of branch lines, each branch line connecting with one of the annular conduits. Valves in the lines control the flow of liquid to the annular conduits. The conduits in the series are arranged for use in the method of the invention in a sequence, beginning with the conduit of greatest flow resistance when the feed rate is low and continuing successively with the conduits of lower flow resistance as the fixed rate increases. The resulting uniform flow rates through the orifices and avoidance of back flow contribute to high yield and quality of product.

Apparatus and method for distributing fluids

Process and apparatus for preparing silver halide emulsions

Growing community of inventors

Rochester, NY, United States of America

Douglas L Oehlbeck