Am International Incorporated

Savin Corporation

Indigo N.v.

Spectrum Sciences B.v.

Inligo, N.v.

George A Gibson

Benzion Landa

Joseph Hall

Peretz Ben-Auraham

Robert M Simms

Ray H Luebbe, Jr

Dinesh G Punater

Mark F Duchesne

Paul V Sadwick

David D Dreyfuss

Curtis B Miller

Joseph S Chow

Margate T Thomas

Roy J Harrington

Jian Wen

A liquid composition for developing latent electrostatic images comprising toner particles associated with a pigment dispersed in a nonpolar liquid. The salient feature of the invention is that the toner particles are formed with a plurality of fibers or tendrils from a thermoplastic polymer and carry a charge of a polarity opposite to the polarity of the latent electrostatic image. The polymer is insoluble or insolvatable in the dispersant liquid at roam temperature. The toner particles are formed by plasticizing the polymer and pigment at elevated temperature and then either permitting a sponge to form and wet-grinding pieces of the sponge or diluting the plasticized polymer-pigment while cooling and constantly stirring to prevent the forming of a sponge while cool. When cool, the diluted composition will have a concentration of toner particles formed with a plurality of fibers.

Toner particles for use in compositions for developing latent

A liquid composition for developing latent electrostatic images comprising toner particles associated with a pigment dispersed in a nonpolar liquid. The salient feature of the invention is that the toner particles are formed with a plurality of fibers or tendrils from a thermoplastic polymer and carry a charge of a polarity opposite to the polarity of the latent electrostatic image. The polymer is insoluble or insolvatable in the dispersant liquid at room temperature. The toner particles are formed by plasticizing the polymer and pigment at elevated temperature and then either permitting a sponge to form and wet-grinding pieces of the sponge or diluting the plasticized polymer-pigment while cooling and constantly stirring to prevent the forming of a sponge while cooling. When cool, the diluted composition will have a concentration of toner particles formed with a plurality of fibers.

Toner and liquid composition using same

The present invention resides in a method for transferring images from an image-bearing surface, to a moving web or sheet. The image-bearing surface is advanced in a predetermined direction, and the receptor area of the image-bearing surface is exposed to successive images. The successive images are developed using a liquid toner comprising charged pigmented particles, in a liquid hydrocarbon carrier. A porous web is transported in synchronism with movement of said image-bearing surface into position for transfer of said developed images on said receptor area successively onto said web. In one embodiment, the web is an uncoated, non-conductive porous material. The web is treated with a fluorinated or partially fluorinated hydrocarbon surfactant hold-out material in an amount effective to reduce the penetration rate of the toner carrier into the web so as to ensure that sufficient carrier is available for complete and void-free transfer. In another embodiment, the same treatment is effective to prevent the leaching of materials from coatings such as those used in the manufacture of carbonless papers.

Treatment to enhance transfer in liquid toner electrophotography

A liquid toner for developing electrostatic latent images, at speeds in excess of 100 ft./min., by electrophoretic movement of pre-charged particles of a thermoplastic polymer in a nonpolar carrier liquid, which reduces drag is disclosed wherein the particles are present in about 10% by weight of the weight of the carrier liquid, and no more than 10% by volume of such toner particles having a size less than 1.0 micron as measured by an Horiba Capa-700. The nonpolar liquid has, typically, a volume resistivity in excess of 10.sup.9 ohm centimeters, a dielectric constant no greater than 3.5, and a vapor pressure of less than 10 millimeters of Mercury at 25 degrees C. The toner composition also includes a quantity of charge director for imparting an electrostatic charge of predetermined polarity to said particles. The toner particles may have a plurality of fibers integrally extending therefrom. Also disclosed is a method of electrostatic printing, at speeds of at least 100 feet-minute, using such liquid developers.

Method of electrostatic printing and toner used in such method

A liquid toner composition for electrophotography comprising a dispersion which includes a carrier liquid, pigmented or dyed toner particles, an inorganic binder insoluble in the carrier liquid at room temperature and a charge control agent in a charge directing amount, said charge control agent comprising lecithin, 1% to 2.5% by weight, based on the total weight of active components in the charge control agent, of an alkylated N-vinyl pyrrolidone polymer, and 0.5% to 10% by weight, based on the total weight of active components in the charge control agent, of an oil soluble or dispersible anionic surfactant.

Charge control agent combination for a liquid toner

A liquid composition for developing latent electrostatic images comprising toner particles associated with a pigment dispersed in a nonpolar liquid. The salient feature of the invention is that the toner particles are formed with a plurality of fibers or tendrils from a thermoplastic polymer and carry a charge of a polarity opposite to the polarity of the latent electrostatic image. The polymer is insoluble or insolvatable in the dispersant liquid at room temperature. The toner particles are formed by plasticizing the polymer and pigment at elevated temperture and then either permitting a sponge to form and wet-grinding pieces of the sponge or diluting the plasticized polymer-pigment while cooling and constantly stirring to prevent the forming of a sponge while cooling. When cool, the diluted composition will have a concentation of toner particles formed with a plurality of fibers.

Toner for use in compositions for developing latent electrostatic

A liquid composition for developing latent electrostatic images comprising toner particles associated with the pigment dispersed in a nonpolar liquid. The salient feature of the invention is that the toner particles are formed with a plurality of fibers or tendrils from a thermoplastic polymer and carry a charge of a polarity opposite to the polarity of the latent electrostatic image. The polymer is insoluble or insolvatable in the dispersant liquid at room temperature. The toner particles are formed by plasticizing the polymer and pigment at elevated temperature and then either permitting a sponge to form and wet-grinding pieces of the sponge or diluting the plasticized polymer-pigment while cooling and constantly stirring to prevent the forming a sponge while cooling. When cool, the diluted composition will have a concentration of toner particles formed with a plurality of fibers.

An automated system and method are provided to supply a liquid toner dispersion to the printing station of a high speed electrophotographic printing press. A highly concentrated form of the liquid toner dispersion is supplied in a first container. Density measurement of the liquid toner in a process tank controls the feed of concentrate to the process tank. Liquid level switches in the process tank control toner carrier liquid flow to the process tank. Conductivity sensor monitoring of the toner in the process tank controls the flow of liquid charge control agent into the process tank. Flow rate of the liquid toner from the process tank to the printing station of the printing unit is controlled by a sensor, logic circuitry, and motorized adjustable flow valve and flow meter.

Liquid toner supply system and method

Improved charge control agent for electrophotographic liquid toners comprising a mixture of lecithin and an alkylated poly-N-vinyl pyrrolidone polymer is disclosed. Methods include applying liquid toners comprising such charge control agent mixture to an electroconductive substrate that has been electrostatically charged in the image areas thereof.

Charge control agent combination of lecithin and pyrrolidone polymer for

Methods of using improved liquid toner dispersions in high-speed electrophotography are disclosed wherein pigment charge homogeneity and mobility are improved by the addition of effective carrier liquid-insoluble monomeric organic acids to the toner solution. Preferred acids include benzoic, succinic, p-toluenesulfonic acid, phenylphosphonic acid, salicylic acid, and 2-nitro and 4-nitrobenzoic acid.

Methods of using liquid tower dispersions having enhanced colored

A copier wherein charge director is supplied to a liquid developer in response to a conductivity measurement thereof. Toner concentrate deficient in charge director is supplied to the liquid developer in response to an optical transmissivity measurement thereof. Conductivity is measured by a pair of spaced electrodes immersed in the developer and through which a variable alternating current is passed. A variable capacitor neutralizes the inherent capacitance of the electrodes. A phase sensitive detector is provided with a reference voltage having the same phase shift as that caused by capacitive effects. The conductivity measurement is corrected in response to a developer temperature measurement.

Liquid developer charge director control

A liquid composition for developing latent electrostatic images comprising toner particles associated with a pigment dispersed in a nonpolar liquid. The salient feature of the invention is that the toner particles are formed with a plurality of fibers of tendrils from a thermoplastic polymer and carry a charge of a polarity opposite to the polarity of the latent electrostatic image. The polymer is insoluble or insolvatable in the dispersant liquid at room temperature. The toner particles are formed by plasticizing the polymer and pigment at elevated temperature and then either permitting a sponge to form and wet-grinding pieces of the sponge or diluting the plasticized polymer-pigment while cooling and constantly stirring to prevent the forming of a sponge while cooling. When cool, the diluted composition will have a concentration of toner particles formed with a plurality of fibers.

An electrophotographic liquid toner composition having lower saturation density and method of reducing the saturation density comprising a toner particle formed from a resin, a solid pigment, and a transparent filler, said pigment and said transparent filler having similar surface energies such that they impart similar triboelectric charging properties to said composition, and said composition is further characterized in that the triboelectric properties of said composition are substantially equivalent to the triboelectric properties of a reference composition in which said filler is not present and in which the combined amount of said pigment is equal to the amount of pigment in said reference composition, and in that said transparent filler lowers the saturation density of said composition so that the saturation density of said composition is lower than the saturation density of said reference composition.

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Vandalia, OH, United States of America

George A Gibson