Abstract:
An inkjet printing system comprising a plurality of static inkjet printing units each comprising at least one inkjet printing head; an ink-receiving element comprising a poorly-absorbing or impermeable substrate; an aqueous inkjet composition which comprises a polymeric compound comprising discrete particles responsive to an external stimulus, and a functional material, which may be incorporated as part of the polymeric particles, the composition having a first rheological state and a different second rheological state in response to a stimulated change in conditions, the first state being associated with a first lower viscosity of the composition, wherein the particles have a first lower volume, and the second state being associated with a second higher viscosity of the composition, wherein the particles have a second higher volume, and of drying the aqueous ink composition only positioned downstream of the plurality of the printing units.
Abstract:
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.
Abstract:
A thermally-responsive dispersant for an aqueous dispersion of positively- or negatively-charged or chargeable solid or liquid particulate, 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.
Abstract:
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.
Abstract:
An inkjet printing system, comprises an inkjet printer, an ink composition, and an inkjet recording media comprising a support, and coated on the support in order from the support, a porous base layer and a porous uppermost layer, each with particular limitations The inkjet recording media and printer system is manufacturable using low-cost materials in an efficient process requiring only a single coating and drying step and that gives images with excellent gloss, color density, and image quality.
Abstract:
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.
Abstract:
An aqueous coating fluid is described comprising gelatin at a concentration of at least 1 wt % and a colloidal particle dispersed material phase at a volume fraction of at least 0.01, wherein at least 20% of the gelatin comprises a gelatin prepared from hydrolysis of ossein using sodium or potassium hydroxide. The present invention enables increasing the concentrations of a coating fluid containing gelatin and dispersed sub-micron colloidal materials, reducing the size of the sub-micron colloidal materials in such a coating fluid, and/or including higher molecular weight gelatin in such a coating fluid without detrimentally increasing the viscosity of such fluids. The invention further enables reducing the viscosity of an aqueous coating fluid containing gelatin and dispersed insoluble colloidal material, without needing to reduce the concentration of gelatin or colloidal materials, increase the size of the sub-micron colloidal materials, and/or reduce the molecular weight of the gelatin. Each such advantage may be achieved either individually, or in combinations to varying extents, without the need to fundamentally change the composition of the materials in the coating fluid.
Abstract:
A flexographic printing composition which comprises a carrier-swellable particle composition, such as a microgel particle composition, has improved printing performance and printing resolution, especially where the flexographic printing composition is an aqueous printing composition and the carrier is water. The composition is particularly beneficial for flexographic printing of such an aqueous printing ink onto low-energy surface substrates or impermeable substrates, in which the ink has improved adhesion, even in the absence of corona discharge treatment. The use of surfactant in an amount of at least 0.5% by weight of the ink composition enhances printed density and/or reduces mottling in solid printed areas.
Abstract:
An inkjet printing system, comprises an inkjet printer, an ink composition, and an inkjet recording media comprising a support, and coated on the support in order from the support, a porous base layer, a porous intermediate layer, and a porous uppermost layer, each with particular limitations. The inkjet recording media and printer system is manufacturable using low-cost materials in an efficient process requiring only a single coating and drying step and that gives images with excellent gloss, color density and image quality.
Abstract:
An inkjet printing system comprising a plurality of static inkjet printing units each comprising at least one inkjet printing head; an ink-receiving element comprising a poorly-absorbing or impermeable substrate; an aqueous inkjet composition which comprises a polymeric compound comprising discrete particles responsive to an external stimulus, and a functional material, which may be incorporated as part of the polymeric particles, the composition having a first rheological state and a different second rheological state in response to a stimulated change in conditions, the first state being associated with a first lower viscosity of the composition, wherein the particles have a first lower volume, and the second state being associated with a second higher viscosity of the composition, wherein the particles have a second higher volume, and of drying the aqueous ink composition only positioned downstream of the plurality of the printing units.