Imation Corporation

Minnesota Mining and Manufacturing Company

Julian M Wallis

Robert J Nairne

Alexis Sarah Zinn-Warner

Dian E Stevenson

Kevin P Hall

Stephen Newman

Anthony L Beck

Martin D Attwood

Sean D Slater

A silver halide emulsion of average grain size 0.2 .mu.m or less comprising silver halide grains having a core and an outer shell, the core comprising at least 85 mol % of the total silver halide content of the grain and at least 50 mol % of the silver halide in the core being silver bromide, and the outer shell comprising silver halide of which greater than 50 mol % is silver chloride; the emulsion either containing no rhodium dopant, or containing rhodium dopant such that the concentration of said dopant is at least as great in the core as in the shell.

Photographic materials with improved image tone

A black and white photographic element comprising as a photosensitive medium a layer of a silver halide emulsion characterised in that the photosensitive medium comprises in the same layer or in an adjacent layer thereto a developer comprising a substantially non-diffusing polymeric compound having as a component part of its structure a plurality of units having a nucleus of general formula (I): ##STR1## wherein; each Z independently is a member selected from the group consisting of --OH and a group which leaves an --OH residue when contacted with an alkali (pH .gtoreq.10) at temperatures of .ltoreq.50.degree. C.

Silver halide imaging materials

Blue-black color favored in medical imaging is imparted to black and white photographic emulsions by the addition of a compound of formula I or II: ##STR1## wherein: R.sup.1 and R.sup.2 independently represent one or more carbon atoms necessary to complete a 5, 6 or 7 membered ring;

Alteration of image tone in black and white photographic materials

A medical X-ray film comprising a transparent base coated on at least one side with (a) a laminar grain silver halide emulsion and (b) a separate hydrophillic colloid layer containing a developing agent for silver halide in an amount corresponding to at least 0.5 moles per mole of the silver coated on that side of the base.

Rapid-access medical X-ray film and process

Gelatin hardeners, suitable for use in hardening gelatin-containing photographic layers, of the formula: ##STR1## wherein: X is a member selected from the group consisting of O and S or is absent, each Y independently is a member selected from the group consisting of O, S and a bond, each R.sup.1 independently represents an aliphatic group of up to 10 carbon atoms or the two R.sup.1 groups together represent the necessary atoms to complete a 5, 6 or 7-membered ring, --NR.sup.2 R.sup.3 contains not more than 12 skeletal atoms and R.sup.2 and R.sup.3 are independently members of the group consisting of hydrogen, cyclic groups and acyclic groups or R.sup.2 and R.sup.3 together represent the necessary atoms to complete a heterocyclic ring.

Growing community of inventors

Harlow, United Kingdom

Julian M Wallis