摘要:
An improvement in the method and apparatus for producing a multi-color electrophotographic image wherein an electrophotographic medium is mounted on a carrier therefor and is translated over a predetermined path so that the medium is first charged, then exposed to a first light-borne image and then toned. Thus, the unexposed portions of the image bearing charged region of the medium are toned, preferably by a liquid toner, to produce a first color visible image. The carrier is then returned to the first position to repeat the foregoing steps to charge the medium and to expose it to a second light-borne image and to tone the second image with a second toning element to produce a second color visible image on the same sheet of medium. One of the images formed is a cyan image. The improvement comprises the steps of: developing the cyan image with a self-fixing, liquid electrographic developer comprising a volatile, electrically insulating liquid carrier and, dispersed in said carrier, (i) toner particles comprising a polymeric binder, cyan pigment and a dispersing agent and (ii) wax particles, and then buffing the surface of the cyan image with a relatively coarse, stiff, and rough fibrous brush member after the cyan developing step and prior to the next charging step to prevent small toner particles present in liquid toner from adhering to the cyan image and thereby contaminating the cyan image and whereby the cyan image does not flake off or smear during the buffing step.
摘要:
A process for making an ink jet ink comprising:a) providing a dispersion containing a pigment, a hydrocarbon carrier and a polyamine/fatty acid condensation polymer dispersant;b) mixing the pigment dispersion with rigid milling media less than 100 .mu.m;c) introducing the mixture of step (b) into a mill;d) milling the mixture from step (c) until the pigment particle size is below about 100 nanometers;e) separating the milling media from the mixture milled in step (d); andf) diluting the mixture from step (e) to obtain an ink jet ink having a pigment concentration suitable for ink jet printers.
摘要:
An electrographic liquid developer includes a fluorescent toner diluted in a liquid developer vehicle which has a high flash point and a low vapor pressure. The liquid developer vehicle preferably is a mixed liquid alkane which has a flash point over 140.degree. F. and a vapor pressure less than 5.2 mm of mercury at 38.degree. C. The fluorescent toner is preferably made as follows:a solution is prepared which comprises an organic solvent, a fluorescent dye, and an organic polymer. A pigment is precipitated by mixing the solution with a non-solvent for the polymer in the presence of a dispersant. The pigment is melt-compounded with a polymeric organic binder and the melt-compounded mixture is comminuted.
摘要:
A method is described for the preparation of electrostatographic toner particles which involves the use of carnauba wax for treating the surface of a pigment employed The method involves recrystallizing carnauba wax from its natural state by dissolution in ethyl acetate and cooling to precipitate needle like structures The structures so obtained are then added to a mixture comprising a pigment, a polymer material, a solvent and optionally a charge control agent which mixture serves as the organic phase in a limited coalescence process. The toner particles produced in accordance with this method are non spherical in nature and evidence excellent fluidity and anti-blocking properties.
摘要:
An electrographic liquid developer includes a fluorescent toner diluted in a liquid developer vehicle which has a high flash point and a low vapor pressure. The liquid developer vehicle preferably is a mixed liquid alkane which has a flash point over 140.degree. F. and a vapor pressure less than 5.2 mm of mercury at 38.degree. C. The fluorescent toner is preferably made as follows:a solution is prepared which comprises an organic solvent, a fluorescent dye, and an organic polymer. A pigment is precipitated by mixing the solution with a non-solvent for the polymer in the presence of a dispersant. The pigment is melt-compounded with a polymeric organic binder and the melt-compounded mixture is comminuted.
摘要:
A process for making an ink jet ink comprising:a) providing a dispersion containing a pigment, a hydrocarbon carrier, and a polyamine/fatty acid condensation polymer dispersant;b) mixing the pigment dispersion with rigid milling media less than 100 .mu.m;c) introducing the mixture of step (b) into a mill;d) milling the mixture from step (c) until the pigment particle size is below about 100 nanometers (nm);e) adding to the mixture during or after step d) or f) (below) a stabilizer selected from the group consisting of a polyether polyol; a modified polyester resin; an acrylic polymer; an alkylol ammonium salt of a block copolymer having acidic groups; ethoxylated triethanolamine; a high molecular weight block copolymer having an amine functionality; sorbitan sesquioleate; polyhydroxy stearic acid; butylated polyvinyl pyrrolidone; poly(vinylpyrrolidone/1-hexadecene); and poly(p-tert-butylstyrene-co-styrene-co-2-sulfoethyl-lithium methacrylate);f) separating the milling media from the mixture milled in step (d); andg) diluting the mixture to obtain an ink jet ink having a pigment concentration suitable for ink jet printers.
摘要:
A liquid ink jet ink wherein said ink is non-gelling and comprises a carrier, a pigment and a solid block copolymer of ethylene oxide and propylene oxide having a structure (A) and (B) defined herein.
摘要:
A process and apparatus is provided for liquid development of a latent electrostatic image. A member bearing an electrostatic image is moved successively past (a) a toner liquid dispersion applying station wherein the latent image is developed, (b) a skiving station wherein residual liquid developer is removed, (c) a rinsing station wherein a rinse liquid is applied, and, if required, (d) another skiving station wherein residual rinse liquid is removed. the first skiving station preferably employs a conductive, resilient roller which is applied under pressure to the member and which is also initially covered with a flush liquid. The rinse liquid is preferably the toner liquid dispersion.
摘要:
The invention provides electrophotographic apparatus for forming a subsequent toner image overlapping one or more toner images previously formed on a surface of an electrophotographic element.The apparatus includes means for electrically charging the surface and the previously formed toner image or images, and means for forming an electrostatic latent image overlapping the previously formed toner image or images on the surface by imagewise exposing the element, through the previously formed toner image or images. The latent image forming means provides actinic radiation of a wavelength outside the range of 400 to 700 nanometers with the density of the previously formed toner image or images to the actinic radiation being less than about 0.2. The apparatus further includes means for electrographically developing the electrostatic latent image to thereby form the subsequent toner image.
摘要:
In plural-stage liquid development of electrostatic charge patterns, as in multicolor electro-photography, image defects occur in areas of the image which are undeveloped or background areas of a previous development stage. The method of the invention avoids such defects by rinsing the image with a polar liquid between development stages to remove counterions which are believed to cause the defects.