According to an example, a resin, a carrier liquid, and a pearlescent pigment may be mixed to form a liquid electrophotographic ink.

Ink-based digital printing systems useful for ink printing include a photoreceptor layer configured to receive a layer of liquid immersion fluid. The liquid immersion fluid includes dampening fluid, dispersed gas particles, and charge directors that impart charge to the solid particles. The photoreceptor surface is charged to a uniform potential, and selectively discharged using an ROS according to image data to form an electrostatic latent image. The charged liquid immersion fluid adheres to portions of the photoreceptor surface according to the electrostatic latent image to form a fountain solution image. The fluid portion of the fountain solution image can be partially transferred to an imaging member and/or transfer member to form a dampening fluid image, either or both of which may be electrically biased. The dampening fluid image is inked on the transfer member, and the resulting ink image transferred to a print substrate.

Example implementations provide a method of controlling an ink developer used in electro-photography; the method comprising, following cessation of printing, varying a plurality of voltages associated with movement of ink within the ink developer at temporally disparate times.

An electrostatic ink composition is disclosed. The electrostatic ink composition can comprise: a liquid carrier; and particles dispersed in the liquid carrier, wherein the particles comprise a thermoplastic resin, and a metal or metal alloy pigment having a melting of point of less than about 200 C. The metal or metal alloy pigment can have a diameter of from about 0.01 m to about 50 m.

The present disclosure relates to a method for producing a conductive liquid electrophotographic ink composition. The method comprises: heating a polymer resin in a carrier liquid to dissolve the polymer resin; adding conductive metallic pigment Particles to the carrier liquid; and cooling the carrier liquid to effect precipitation of the polymer resin from the carrier liquid, such that a coating comprising the resin is formed on the conductive metallic pigment particles; wherein: I) the polymer resin comprises (i) a copolymer of an alkylene monomer and a monomer selected from acrylic acid and methacrylic acid, and (ii) an ionomer of an alkylene monomer and a monomer selected from acrylic acid and methacrylic acid, wherein at least a portion of the acrylic acid and/or methacrylic acid groups are neutralised with metal ions; and/or II) a charge adjuvant is included in the coating that is formed on the conductive metallic pigment particles.

A method for producing a liquid developer containing a resin binder containing a resin having an acidic group, a colorant, a basic dispersant, and an insulating liquid, including: step I: stirring raw materials containing the resin binder, the colorant, and the basic dispersant at a temperature of equal to or higher than a glass transition temperature of the resin binder; and step II: adding dropwise from 50 to 500 parts by mass of the insulating liquid to a stirred mixture of the step I, based on 100 parts by mass of the stirred mixture at a temperature of equal to or higher than a glass transition temperature of the resin binder, thereby carrying out a phase inversion emulsification, to provide a dispersion of toner particles. The liquid developer obtainable by the method of the present invention is suitably used in development or the like of latent images formed in, for example, electrophotography, electrostatic recording method, electrostatic printing method or the like.

Herein is disclosed an electrostatic ink composition. In some examples, the electrostatic ink compositions comprise: a carrier liquid; a resin; and a phosphorescent pigment.

Described herein is a LEP ink composition comprising a luminescent component, a resin; and a carrier liquid security liquid electrostatic ink composition for printing a security image.

A method for treating a substrate is provided herein. The method includes providing a substrate and applying a composition to the substrate to form the treated substrate. The composition includes a binder, a binder additive, and an aluminum salt. A method for improving adhesion of an image to the treated substrate is also provided herein. The method includes providing the substrate, applying the composition to the substrate to form the treated substrate, and applying a liquid toner to the treated substrate to form the image on the treated substrate. A printed material exhibiting improved adhesion of the image to the treated substrate is also provided herein. The printed material includes a treated substrate. The treated substrate includes the substrate and a coating disposed on the substrate and formed from the composition. The printed material further includes the image disposed on the treated substrate and formed from the liquid toner.

A liquid electrophotographic (LEP) ink can include a liquid ink vehicle, a conductive toner including a conductive pigment and a polymeric binder, and a charge director. The liquid electrophotographic ink can have a conductivity of from 150 to 2000 picoSiemens.