Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/12—Developers with toner particles in liquid developer mixtures
  • G03G9/13—Developers with toner particles in liquid developer mixtures characterised by polymer components
  • G03G9/132—Developers with toner particles in liquid developer mixtures characterised by polymer components obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/12—Developers with toner particles in liquid developer mixtures
  • G03G9/13—Developers with toner particles in liquid developer mixtures characterised by polymer components
  • G03G9/131—Developers with toner particles in liquid developer mixtures characterised by polymer components obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/12—Developers with toner particles in liquid developer mixtures
  • G03G9/135—Developers with toner particles in liquid developer mixtures characterised by stabiliser or charge-controlling agents
  • G03G9/1355—Ionic, organic compounds
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
  • Y10S430/001—Electric or magnetic imagery, e.g., xerography, electrography, magnetography, etc. Process, composition, or product
  • Y10S430/105—Polymer in developer

Definitions

• ABSTRACT A liquid developer for use in an electrostatic copying process in which the developer is made up of an organosol part comprising a tacky component and a minor amount of a release agent, both of which have electrophoretic properties and both of which are substantially insoluble in a light hydrocarbon liquid having a kauributanol number less than 30, the organosol part being suspended in such light hydrocarbon liquid together with a pigment part.
• the Xerox method is one in which there is a transfer of the particles to a charged paper surface on which the thermoplastic resin particles in the form of the image are fused.
• the electrostatic charge is deposited on a paper coated with a photoconductor such as zinc oxide, and there is no transfer of the image from the zinc oxide photoconductive surface to another surface.
• pigment particles are enrobed in a control agent for the purposes of giving the particles the required charge for deposition on the photoconductor surface carrying the latent image.
• the control agent which is insoluble in the developer carrier liquid, also is of a non-tacky nature.
• the developing liquid comprises essentially a carrier fluid in which a tacky toner material is dispersed.
• the tacky or sticky toner material can be transferred from the photoconductive surface to plain paper provided the tacky toner has a greater affinity for the paper surface than for the photoconductive surface.
• the affinity for the photoconductive surface can be decreased by coating it' with a sili-' cone or a urethane film so that the image developed with the tacky toner will have greater affinity for the paper than for the photoconductive surface. The coating of a photoconductive surface tends to reduce its efficiency.
• a further object of our invention is to provide a developing fluid for latent electrostatic images containing an organosol provided with a release agent resulting in a reduced affinity for. the photoconductive surface.
• our invention contemplates the provision of an improved liquid developer for use in an electrostatic copying process in which we mill an organosol comprising a tacky component and aminor amount of a release agent together with a pigment component in a light hydrocarbon liquid having a kauri-butanol number of less than 30, and in which the tacky component and the release agent both have electrophoretic properties and both are substantially insoluble in the hydrocarbon liquid.
• the amount of the release agent in the liquid toner should not exceed a certain amount by weight of the tacky component, such as high molecular weight resin on the organosol employed in the liquid toner composition.
• the organosol comprises 37.5 grams of Pliolite VTAC not more than about 15 grams of a silicone resin should be dispersed through the developing fluid.
• Pliolite VTAC is the registered trademark of Goodyear Tire & Rubber Co., Akron, Ohio, for a vinyl-toluene, acrylate copolymer resin having a specific gravity of 1.026 and a softening point of i 3C.
• the reaction may be continued, and final curing may charged an organic photoconductor positively and exbe effected by heating with a catalyst such as the octo posed the latent image areas to developer comprising ates or naphthenates.
• Rhodorsil 6354" silicone resins grams of polyvinyl chloride iso-butyl ether dissolved are low molecular weight siloxanols with a hydroxyl in 25 grams of Solvesso 100. Solvesso 100" is the content of between three and five percent. The hyregistered trademark of Humble Oil and Refining Co.
• Solvesso 100 is a basic acid. Copolymerization takes place as follows:
• the polyvinyl chloride balt octoate or manganese octoate in the amount of 25 iso-butyl ether may be used as a negative developer grams, is mixed with 50 grams of lsopar G.
• the silicon conferring its release properties to a negative developmix and the catalyst mix are then mixed and stirred toing fluid, the positive charge adhesive toners tested gether.
• the silicon resin is mixed with lsopar G in order using this negative charge polyvinyl chloride iso-butyl to lower its viscosity so the catalyst can be stirred into ether produced images inferior to release agents exhibthe mix and distributed evenly therethrough. The cataiting positive charge properties.
• the major applica lyst is also diluted with lsopar G to improve the mixing for this material is as a release additive for an adhesive of the catalyst with the silicon resin.
• a positive charged photoconduc- 050] component of the toner concentrate we add 25 tor.
• grams of the silicon resin catalyst mixture comprising 10 grams of the actual silicon resin to 37.5 grams of EXAMPLE A Pliolite VTAC and 40 grams of Solprene 1205 in In formulating the organosol part, we first mix 250 100 grams of Solvesso 100.
• Pliolite VTAC is the reggrams of a silicon resin with 250 grams of lsopar G.
• silicon resin is an organo polysiloxane having the gen- Akron, Ohio, for a vinyl-toluene/acrylate copolymer eral formula of: having a specific gravity of 1.026 and a softening point R R R of 50 i 3C.
• Solprene 1205 is the registered trade- I mark of Phillips Petroleum Company for a block co- O o 6( polymer of butadierre and styrene In the who of 75 to 25 made by a solution polymerizatlon process.
• One pigment part may, in which R is either a methyl or phenyl group and a for example, be made up of 200 gm microlith black, 25 number of reactive groups which allow the linear polygm reflex blue, 50 gm Pliolit VTAC dissolved on t mer and catalyst to form a cross-linked space polymer.
• R is either a methyl or phenyl group and a for example, be made up of 200 gm microlith black, 25 number of reactive groups which allow the linear polygm reflex blue, 50 gm Pliolit VTAC dissolved on t mer and catalyst to form a cross-linked space polymer.
• Solvesso 100, gm Solvesso 100, and 40 gm These silicon resins may be obtained from Rhone- Solprene 1205 dissolved one to two in mineral turps. Poulenc, of Paris, France, and are sold under the trade This material is milled on a triple roll mill and then dismarks Rhodorsil 10310 C
• 120 mls of the pigment part are added to the organosol and milled in a colloid mill with 1 100 mls of lsopar G to form the toner concentrate.
• the silicon resin with the catalyst forms a dispersion which will produce a visible image acting as electrostatic toner per se.
• the organosol comprises 37.5 grams of Pliolite VTAC, 30 grams of Solprene 1205, grams of Pliolite AC3", an amount of the silicon resin-catalyst mix which is described above to provide 10 grams of the silicon resin, and 200 grams of Solvesso E 100.
• Pliolite AC3 is the registered trademark of Goodyear Tire and Rubber Company for a styrene/acrylate thickening agent which forms thixotropic gels in both aliphatic and aromatic solvents. It has a specific gravity of 1.026 and a softening point of 50: 3C.
• the organosol'mix containing the silicon is then added to 1 100 mls of lsopar G circulating in a cavitation mill together with 120 mls of toner component.
• the toner component may comprise 100 grams of microlith black, 12.5 grams of reflex blue, 25 grams of Pliolite VTAC, and 35 grams of S01- vesso 100.
• This material is milled on a triple roll mill and the mill mix is stirred into 25 gms of Solprene 1205 previously dissolved in 50 gms of Solvesso 100. This mix is milled in a cavitation mill for about three minutes with 600 mls of lsopar G to form the pigment part.
• the organosol and 120 mls of toner component then are milled approximately three minutes to form the developing fluid concentrate.
• This concentrate is further diluted to form a solution by mixing 300 mls of the toner concentrate with 1700 mls of lsopar G.
• This forms the working toner which is used to form images on uncoated organic photoconductive surfaces. These images will readily release from the organic photoconductor and transfer readily to plain paper.
• EXAMPLE C In this example the organosol part was formed from the same components as outlined in Example B but the amount of silicon-catalyst mix was such as to provide 12.0 gms of the silicon resin. The resultant organosol together with 120 mls of the pigment part used in Example B is milled with 1100 mls of lsopar G.
• EXAMPLE D The organosol was formed in the same manner as Examples B and C but the amount of silicon-catalyst mixture was increased to provide a resultant of 14.0 gms of the silicon resin.
• the pigment part is the same as that described in our copending applicationplt is made up of 100.0 gms of microlith black; 12.5 gms reflex blue; 25.0 gms Pliolite VTAC, and 25.0 gms of Solprene 1205 which were milled on a triple roll mill with sufficient toluol to afford the correct milling viscosity. After milling the mixture was diluted with 600 mls of lsopar G to form the toner part.
• the organosol part was mixed with 240 mls of this pigment part and milled in a cavitation mill with 1 100 mls of lsopar G for about three minutes toforn the toner concentrate.
• This concentrate is further diluted in the ration 1 part by volume of concentrate to 4 parts of lsopar G to form the toner.
• organosol part using 37.5 gms of Pliolite VTAC, 10.0 gms of Solprene 1205, 200 gms of Solvesso 100 and an amount of the silicon catalyst mix providing 14.0 gms of the silicon resin in the organosol.
• EXAMPLE EXAMPLE G (S91 Adhesive Toner) We milled the following formulation on a triple roll mill:
• EXAMPLE H (T18 Adhesive Toner) l. Toner Component B923 ariti e? 100.0 gms Microlit h Black CT.
• VTAC and DiButyl Furmarate are pre-dissolved.
• the above mix is milled on a triple roll mill.
• Organosol Solution 37.5 g. Pliolite VTAC 5.0 g. Solprene 1205 100.0 g. Solvesso 100 10.0 g. Rhodorsil silicone 6354 This mix is allowed to dissolve at room temperature.
• Adhesive Toner T18 120 mls of B923 is stirred into the organosol solution to form the toner paste.
• This paste is added to one litre of lsopar G circulating in the Mark 9B toner mill during a five-minute period. Total milling time is ten minutes.
• Mill speed is 2800 rpm. with smooth rotor and stator.
• the temperature rise is five degrees C and power consumption 50 to 75 Watts.
• the toner is then drained from the machine into a half-gallon tin and stored.
• the particle size is just visible to the naked eye and approximately A; inch sediment forms on the bottom of the tin on standing for 7 days. This sediment is redispersed by agitation. This formulation has been repeated with 5 gms of silicone and produces similar results.
• the organosol in this instance comprises a reactive silicon fluid having the general formula:
• An amount of the fluid providing 10.0 gms of the silicon resin. 37.5 gms of VTAC Pliolite, and 30.0 gms ol Solprene 1205 are mixed to form the organosol. We mill 240 mls of the pigment part of Example A with the organosol and 1 100 mls of lsopar G to form the toner concentrate.
• ferririgto Example H above; we replaced the 10 gms of silicone 6354 with 2 gms of aluminum oleate, the other components and method of mixing being the same.
• the toner with the metallic soap produced an acceptable transfer characterized by a low peel force at the point of separation between the photoconductori and the paper. A small amount of the image is left on the organic photoconductor, but this residue is easily removed and cleaned. 1f the metallic soap is increased to more than 5 gms, the cohesion of the toner decreases and produces an undesirable image squash.
• the aluminum oleate also acts an anti-settling agent and reduces the time required for the toner paste let down in the toner mill.
• EXAMPLE K (S71 Adhesive 'loner) We milled the following formulation on a triple roll mill:
• the toner particles are not visible to the naked eye and the toner produces A; inch sediment on standing in a half-gallon can during a seven-day period.
• This toner does not operate effectively until 24 hours after colloid milling. Let down in the toner mill Mark 93, instead of the P.U.C. colloid mill, does not reduce this aging period.
• EXAMPLE L As has been pointed out hereinabove, we have discovered that materials other than silicon resins both are insoluble in lsopar G and are electrophoretic. We have formed toners from such materials. For example, we made up an organosol from 0.2 gm polyethylene wax, 37.5 gms Pliolite VTAC, 10.0 gms Solprene 1205, and 200.0 gms Solvesso 100. The polyethylene wax is heatmelted into lsopar G and then added to the organosol. This organosol was milled with 240 mls of the pigment part of Example D and 1100 mls of lsopar G to form the concentrate. v
• our improved developer includes a release additive.
• This additive must possess two characteristics. First, it must be substantially insoluble in a light hydrocarbon liquid having a kauri-butanol number of less than 30 but must form a dispersion therein. Secondly. the release agent must be electrophoretic. ln determining whether or not a material is suitable for use as a release additive, tests are performed to determine whether or not it possesses the required characteristics. First it is mixed with lsopar G to see if it forms a dispersion rather than a solution therein. If it forms a dispersion a latent electrostatic image is subjected to the action of the dispersion. If the release agent possesses the required electrophoretic property observation of the surface bearing of the image reveals a more or less readily discernible development of the image.
• an organosol is made up of a high molecular weight tacky resin and of the release agent.
• the organosol is milled with a suitable pigment part and carrier liquid to form the toner concentrate.
• the toner concentrate is then diluted by mixing 1 part by volume of concentrate with 4 parts of carrier liquid.
• the amount of release agent in the developer must not be too great. If too much release agent is used the air nozzle of the machine may blow the developed image off the photoconductor surface. Further where the machine incorporates a squeege roll the developer must be so made up as to avoid image squash". While the percentage of release agent is determined in some degree by the characteristics of the agent itself, it will be seen from the examples given above that the amount of release agent does not exceed 303% by weight of the high molecular weight tacky resin in the organsol.
• the tacky resin component of the organosol may be employed.
• the release agent may beany material meeting the criteria set forth above.
• Silicon resins of the type described above are manufactured and sold by Rhone Poulenc, of Paris, France, under the name Rhodorsil" l03l0, 6354 or 20019,
• Developers of the type described above were used to develop latent images formed on an endless belt having an organic photoconductor on its surface.
• the surface was first charged to a surface potential of 700 volts, exposed to an image and subjected to the developer.
• the developed image was then readily transferred to a material such as paper at a temperature of 100 to 140F.
• a developing liquid composition adapted to develop a latent electrostatic image to form a transferable visible image on a photoconductive surface including in combination a light isoparaffinic hydrocarbon carrier liquid means having a l auri-butanol number of less than 30, a tacky organosol means formed by dissolving a high molecular weight resin polymer in an aromatic hydrocarbon solvent, said high molecular weight resin being insoluble in the light isoparaffinic hydrocarbon carrier liquid and having electrophoretic properties, said organosol means being dispersed in said carrier liquid means, release agent means adapted to facilitate the transfer of said visible image from the photoconductor to a supporting surface, said release agent means being insoluble in said carrier liquid means and present in said composition between 6% and 30% by weight of said high molecular weight resin polymer, both said organosol means and said release agent means having such electrophoretic properties that both will codeposit on said latent electrostatic image from said developing liquid, the composition being such that the transfer of the developed image from the photoconductive surface to said supporting surface is

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Liquid Developers In Electrophotography (AREA)
• Developing Agents For Electrophotography (AREA)

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Cited By (9)

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Citations (8)

• 1972
  • 1972-07-05 US US00269054A patent/US3850829A/en not_active Expired - Lifetime
• 1973
  • 1973-06-15 AU AU56988/73A patent/AU5698873A/en not_active Expired
  • 1973-06-20 IT IT25679/73A patent/IT989356B/it active
  • 1973-07-03 DE DE19732333741 patent/DE2333741A1/de active Pending
  • 1973-07-05 JP JP48075310A patent/JPS4945742A/ja active Pending
  • 1973-07-05 FR FR7324818A patent/FR2191159A1/fr not_active Withdrawn

Patent Citations (8)

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