Abstract: Systems, apparatuses, and methods of fluid delivery for liquid electrophotography printing. A fluid delivery apparatus includes a charged ink source, a supplemental fluid source, a working suspension tank in fluid communication with the charged ink source and the supplemental fluid source, a sensor, and an optical density control unit. The charged ink source is to store a charged ink mixture including charge directors and toner particles. The supplemental fluid source is to store a supplemental fluid including imaging oil. The working suspension tank is to store a working suspension mixture including the charge directors, the toner particles, and the imaging oil. The sensor is to monitor an optical density of print output of the liquid electrophotography printing apparatus. The optical density control unit is to determine whether to supply an uncharged ink mixture to the working suspension tank in response to the monitored optical density indicating electrical fatigue.

Abstract: A liquid electrophotographic (LEP) ink composition is described. The composition comprises: a pigment particle having an acidic surface modification; a basic charge director selected from:(i) a polymeric amine dispersant having a Total Base Number of at least 100 mg KOH/gram material, and (ii) a sulfosuccinate salt of the general formula MAn, wherein M is a metal, n is the valence of M, and A is an ion of the general formula (I): [R1—O—C(O)CH2CH(SO3)C(O)—O—R2]? (I); and a liquid carrier. The ink composition does not include a thermoplastic resin. Also described are a method of producing the ink composition, and a method of printing using the ink composition.

Abstract: A method of calibrating a developer unit of a liquid electrophotographic printer, the method comprising: setting a developer roller voltage and iteratively printing a patch on a print medium using different electrode voltages until a hue of a patch printed using one of the electrode voltages is within a tolerance of a target hue; and setting an electrode voltage based on said one of the electrode voltages and iteratively printing a patch on a print medium using different developer roller voltages until a hue of a patch printed using one of the developer roller voltages is within the tolerance of the target hue.

Abstract: Described herein is magenta ink composition, comprising a pigment consisting of one or more quinacridone pigments; a resin; and a polymeric amine dispersant having a Total Base Number of at least 300 mg KOH/gram. Also described herein is a method of printing comprising applying the magenta ink composition to a substrate, and a printed substrate comprising the magenta ink composition.

Abstract: In one aspect, the present disclosure relates to a liquid electrophotographic electrode ink composition comprising: a thermoplastic polymer comprising a copolymer of an olefin and acrylic acid and/or methacrylic acid; an electroactive material comprising a lithium intercalation material; a charge adjuvant, and a liquid carrier.

Abstract: Described herein is a yellow liquid electrophotographic ink composition comprising: a thermoplastic resin comprising a polymer having acidic side groups; and a colorant comprising a yellow pigment, wherein the yellow pigment comprises a hydrazone compound. Also described herein is a method of producing a printed substrate using the yellow liquid electrophotographic ink composition and a printed substrate produced therefrom.

Abstract: A method of calibrating a developer unit of a liquid electrophotographic printer, the method comprising: setting a developer roller voltage and iteratively printing a patch on a print medium using different electrode voltages until a hue of a patch printed using one of the electrode voltages is within a tolerance of a target hue; and setting an electrode voltage based on said one of the electrode voltages and iteratively printing a patch on a print medium using different developer roller voltages until a hue of a patch printed using one of the developer roller voltages is within the tolerance of the target hue.

Abstract: Herein is described a liquid electrophotographic (LEP) ink composition comprising: a hydrocarbon carrier liquid; a resin; a colorant comprising a conjugated compound; and a component selected from: an amine-containing basic dispersant having a total base number greater than about 300 mgKOH/g material; or an amine-containing compound having a pKa of 8 or more at 25° C.; or urea.

Abstract: Herein are describes liquid electrophotographic ink compositions and methods for producing liquid electrophotographic ink composition. The liquid electrophotographic ink compositions may be producing using a method comprising: grinding a resin and a pigment to form a paste; reacting an aluminium C12-24 carboxylate and a molecule having a molecular weight (Mw) of less than about 1000 and comprising a functional group selected from an amide, an ester, a carboxylic acid, an amine, an imide and combinations thereof to form a charge promoting component; and combining the paste and the charge promoting component to form a liquid electrophotographic ink.

Abstract: In one aspect, the present disclosure relates to a liquid electrophotographic electrode ink composition comprising: a thermoplastic polymer comprising a copolymer of an olefin and acrylic acid and/or methacrylic acid; an electroactive material comprising a lithium intercalation material; a charge adjuvant, and a liquid carrier.

Abstract: In an example of a printing system, the amount of a printing fluid that is transferred from a developer unit onto an imaging plate is varied in order to alter the optical density of an area covered by the printing fluid.

Abstract: In an example of a printing system, the amount of a printing fluid that is transferred from a developer unit onto an imaging plate is varied in order to alter the optical density of an area covered by the printing fluid.

Abstract: Herein is described a liquid electrostatic ink composition comprising a carrier liquid, a resin, a colorant selected from a magenta colorant, a cyan colorant and a black colorant, an amine-containing basic dispersant having a total base number (TBN) in the range of about 10 to about 65 mgKOH/g material, the amine-containing basic dispersant present in an amount from about 5 wt. % to about 40 wt. % by total weight of colorant.

Abstract: Herein is disclosed magenta liquid electrostatic ink compositions. In some examples, the electrostatic ink compositions comprise a magenta pigment, a basic dispersant, a resin comprising a polymer having acidic side groups, a carrier liquid and a charge director, wherein the dispersant comprises a compound comprising a succinimide group linked to a primary, secondary or tertiary amine.

Abstract: Herein is disclosed an electrostatic ink composition, wherein the composition is formable by combining: chargeable particles comprising a resin comprising a polymer having acidic side groups, and a cyclic anhydride. Also disclosed herein is a method of forming an electrostatic ink composition, and a method of electrostatic printing.

Abstract: Herein is disclosed a cyan electrostatic ink composition, the cyan electrostatic ink composition comprising: a cyan pigment, a basic dispersant, a phthalocyanine having acid groups, a resin and a charge director.

Abstract: Herein is disclosed an electrostatic ink composition. In some examples, the electrostatic ink compositions comprise: a carrier liquid; a first resin; and a fluorescent pigment. The fluorescent pigment comprising a fluorescent dye and a second resin matrix, wherein the second resin is selected from the group comprising polyamide resins, polyvinylchlorides, polyolefin resins, polystyrenes, acrylonitrile-butadiene-styrene resins, polycarbonates, poly acrylic and methacrylic acid resins, polyethylene terephthalates, polyamide resins, polyurethanes, epoxy resins, silicone resins, polyester resins, alkyd resins, acrylonitrile polymers, polyesteramides or combinations thereof.

Abstract: Herein is described a liquid electrostatic ink composition comprising a carrier liquid, a resin, a colorant selected from a magenta colorant, a cyan colorant and a black colorant, an amine-containing basic dispersant having a total base number (TBN) in the range of about 10 to about 65 mgKOH/g material, the amine-containing basic dispersant present in an amount from about 5 wt. % to about 40 wt. % by total weight of colorant.

Abstract: Herein is described an electrostatic ink composition comprising a carrier liquid, aluminium stearate particles, and an aluminium stearate binding agent dissolved in the carrier liquid, wherein the aluminium stearate binding agent comprises an acidic binding group which is bound to an aluminium stearate particle.

Abstract: A magenta liquid electrostatic ink composition includes chargeable particles having a resin and a pigment; an insulating, non-polar, non-aqueous liquid carrier in which the chargeable particles are dispersed; and a charge director. The resin is formable from polymerizing alkylene monomers and methacrylic or acrylic acid monomers; the pigment is selected from pigment violet 19 type ?I, pigment violet 19 type ?II, pigment violet 19 type 1, pigment red 177, pigment red 208, and pigment violet 32; and the liquid electrostatic ink composition lacks any other types of pigment.