Eastman-kodak Company

John H Hone

Andrew M Howe

Alan R Pitt

Trevor J Wear

Thomas Henry Whitesides

Ian M Newington

Andrew Clarke

Danuta Gibson

Stephanie V Desrousseaux

John M Higgins

Christian V Nicholas

A thermally-responsive dispersant for an aqueous dispersion of positively- or negatively-charged or chargeable solid or liquid particulates, comprises a compound having an anchoring moiety linked to a thermally-responsive polymeric stabilizing moiety, other than a polyalkylene oxide, the polymeric moiety having a lower affinity for the surface than the anchoring group below the thermal transition temperature, the particulates being positively-charged or chargeable when the anchoring moiety contains an acid and/or hydroxy group and has a net acidity or neutrality and the particulates being negatively-charged or chargeable when the anchoring moiety has a basic group and has a net basicity, wherein the dispersion exhibits a change in sign from negative to positive and an increase in magnitude of a rheological property (viscosity at low shear and/or complex modulus at low amplitude oscillatory shear), on increasing the temperature from below to above the thermal transition temperature.

Thermally-responsive dispersants for media formulations

The invention provides an aqueous inkjet ink composition comprises a polymeric compound comprising discrete particles responsive to an external stimulus, and a functional material, wherein the functional material may be incorporated as part of the polymeric particles, the particles causing the composition to have a first rheological state and a different second rheological state in response to a stimulated change in conditions, the first rheological state being associated with a first lower viscosity of the composition, wherein the particles have a first lower volume, enabling the composition to pass through an inkjet printhead orifice and the second rheological state being associated with a second higher viscosity of the composition, wherein the particles have a second higher volume, enabling immobilisation of droplets of the composition on a substrate. The inkjet composition is particularly useful in a continuous inkjet printing system for printing onto a wide range of surfaces including impermeable surfaces.

Ink for printing on low energy substrates

The invention provides a dispersant for an aqueous dispersion of negatively charged or chargeable solid particulates which comprises a compound having an anchoring moiety linked to a polymeric hydrophilic moiety, the anchoring moiety containing at least one basic group and having an overall basicity and the polymeric moiety having a lower affinity for the particulate surface than the anchoring moiety. The invention also provides a coating composition containing the dispersant, an inkjet recording element containing the dispersant and methods of coating or reducing viscosity using the dispersant.

Coating composition containing a dispersant

The invention provides a dispersant for an aqueous dispersion of positively charged or chargeable solid particulates which comprises a compound having an anchoring moiety linked to a polymeric hydrophilic moiety, the anchoring moiety containing at least one acid and/or hydroxy group and having an overall acidity or neutrality and the polymeric moiety having a lower affinity for the particulate surface than the anchoring moiety. The anchoring moiety preferably contains at least two acid groups, preferably carboxylic acid groups, attached either in a [1,1], [1,2] or [1,3] relationship and is linked to the polymeric moiety, which is preferably derived from acrylamide or methacrylamide monomer units, preferably by a sulfur atom. The dispersant can reduce the viscosity of an aqueous dispersion of positively charged or chargeable solid particulates and can reduce the tendency of the resulting dispersion to form a gel or a yield stress material. The dispersant facilitates the processing of the resulting compositions in manufacturing operations and it may be used, for example, as a component of a coating material, a ceramic, paint, refractory material, filler or in an inkjet recording paper or film. Additionally, the dispersant can allow the use of higher concentrations of solid particulates and enable control of the yield stress, as some yield is often beneficial in helping prevent or reduce sedimentation.

Dispersant for reducing viscosity of particulate solids

The invention provides a coating composition containing boehmite particles and a dispersant which comprises a compound having an anchoring moiety linked to a polymeric hydrophilic moiety, the anchoring moiety containing at least one acid and/or hydroxy group and having overall acidity or neutrality and the polymeric moiety having a lower affinity for a boehmite surface than the anchoring moiety. The anchoring moiety preferably contains at least two acid groups, preferably carboxylic acid groups, attached either in a [1,1], [1,2] or [1,3] relationship and is linked to the polymeric moiety, which is preferably derived from acrylamide or methacrylamide monomer units, preferably by a sulfur atom. The dispersant can reduce the viscosity of the boehmite dispersion and the tendency of the boehmite dispersion to increase in viscosity and/or form a gel or a yield stress material following periods of high shear stress.

Coating composition comprising boehmite particles and one or more dispersants and a method of coating a substrate using said coating composition

The incorporation of coupler chemistry into the fluorescent element results in a greatly improved fluorescence imaging element, displaying higher photographic speed, higher contrast, and improved image discrimination. The coupler chemistry comprises the combination of a developing agent that generates an oxidized form on reaction with exposed silver halide, together with a molecule capable of forming a stable reaction product, preferably a dye, by reaction with the oxidized form of the developer. This will have the effect of a sink for oxidized developer formed during development. In a preferred embodiment, dye-forming chemistry is combined with fluorescent imaging to provide dramatic improvements in performance of the fluorescent system.

Fluorescent photothermographic imaging element comprising coupling agent

The present invention is directed to a photothermographic imaging element comprising at least one silver halide imaging layer containing a fluorophore. The imaging element can be exposed and then processed by heating to form an image in which the intensity of the fluorescence from the element is modulated imagewise to yield a fluorescent image of the light intensities to which the element was exposed. The present invention is also directed to a method of processing photothermographic film that has been imagewise exposed in a camera, which method in order comprises thermally developing the film step without any externally applied developing agent, comprising heating said film to a temperature greater than 80&deg; C., preferably in an substantially dry process, and detecting the luminescence latent image emitted by a fluorescent dye associated with at least one imaging layer and, based thereon, providing a digital electronic record, wherein substantial amounts or all of the silver and silver halide salts in the film are not removed before detection. A preferred embodiment of the invention is directed to a color photothermographic film.

Growing community of inventors

Chalfont St. Peter, United Kingdom

John H Hone