EP0119713B1 - Développateurs électrographiques liquides - Google Patents

Développateurs électrographiques liquides Download PDF

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Publication number
EP0119713B1
EP0119713B1 EP19840300812 EP84300812A EP0119713B1 EP 0119713 B1 EP0119713 B1 EP 0119713B1 EP 19840300812 EP19840300812 EP 19840300812 EP 84300812 A EP84300812 A EP 84300812A EP 0119713 B1 EP0119713 B1 EP 0119713B1
Authority
EP
European Patent Office
Prior art keywords
methacrylate
monomer
carrier
developer
acrylate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19840300812
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German (de)
English (en)
Other versions
EP0119713A1 (fr
Inventor
Peter Steven Alexandrovich
Louis Joseph Sorriero
Chandra Sreekumar
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eastman Kodak Co
Original Assignee
Eastman Kodak Co
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Filing date
Publication date
Application filed by Eastman Kodak Co filed Critical Eastman Kodak Co
Publication of EP0119713A1 publication Critical patent/EP0119713A1/fr
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Expired legal-status Critical Current

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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
    • G03G9/131—Developers with toner particles in liquid developer mixtures characterised by polymer components obtained by reactions only involving carbon-to-carbon unsaturated bonds

Definitions

  • the present invention relates to a liquid electrographic developer composition
  • a liquid electrographic developer composition comprising an electrically insulating carrier liquid, a toner dispersed in the carrier, a quaternary ammonium polymer to control the electrical charge on the pigment, and a polar copolymer to impart charge to the toner dispersion.
  • charge images are formed on a-substrate and thereafter rendered visible by contact with an electrographic developer composition.
  • electrographic developer compositions are formulated in dry or liquid form, each presenting its own unique requirements and advantages.
  • a conventional liquid electrographic developer is a dispersion of toner particles, usually of a pigment and a binder resin, in an electrically insulating carrier liquid such as a volatile hydrocarbon fraction.
  • the binder resin serves to bind the pigment to the final copy sheet, usually upon the application of heat.
  • the developer can also contain a stabilizer additive to maintain a stable dispersion of the toner particles.
  • Liquid developers also often contain a charge-control agent to maintain a constant charge level.
  • Liquid electrographic developers have been proposed which contain polymers uniformly dispersed in the carrier liquid.
  • U.S. patent 3 788 995 describes a liquid developer comprising, dispersed in the carrier liquid, at least one polymer containing units of at least two monomers, one of which is a polar monomer selected from inter alia, sulfoalkyl acrylates and methacrylates, and their metal and amine salts, and another of which is a solubilizing monomer such as an alkyl acrylate having 8 to 22 carbon atoms in the alkyl portion.
  • Units of an insolubilizing monomer such as styrene or an alkyl acrylate having up to 4 carbon atoms in the alkyl portion, may also be present.
  • the stabilizing monomer is used in sufficient quantity to give the copolymers a specified minimum dispersibility. It is preferred to disperse uniformly in the carrier liquid a second copolymer having up to 20% by weight of units from a polar monomer, units from an insolubilizing monomer, and possibly, units from a solubilizing monomer.
  • a particularly useful liquid developer is disclosed in US Patent 4 273 849.
  • This developer comprises an electrically insulating carrier liquid having stably dispersed therein (1) toner particles of a halogenated polymer, and having dissolved therein (2) a copolymer of a quaternary ammonium salt monomer and a solubilizing monomer, this copolymer being free of alkali metal and alkaline earth metal cations, and (3) an addition copolymer of a polar monomer and a solubilizing monomer, the amount of solubilizing monomer is each copolymer being sufficient to make the copolymer soluble in the carrier liquid.
  • the toner particles (1) are negatively charged and the copolymer (2) is believed to act both as a dispersing agent for.them and as a charge-control agent.
  • the copolymer (3) is added to stabilize the dispersion.
  • It is the object of the present invention to provide an electrographic liquid developer composition comprising negatively or positively charged dispersed toner particles and a dissolved polymeric charge-control agent in which the charge of the developer per unit mass of toner is stabilized so as to increase less rapidly during use.
  • the present invention provides a liquid electrographic developer composition
  • a liquid electrographic developer composition comprising an electrically insulating liquid carrier which contains dispersed toner particles and in which at least two addition copolymers are uniformly dispersed, the dispersed copolymers comprising a first carrier-soluble copolymer as a charge-control agent which contains units of a quaternary ammonium salt monomer and units of a solubilizing monomer, and a second carrier-soluble copolymer as a charging agent which contains units of a polar monomer and units of a solubilizing monomer characterized in that the first copolymer additionally contains units of an insolubilizing monomer having and acidic function of formula -COOH, -S0 3 H or P0 3 HR, where R is hydrogen or alkyl.
  • R is alkyl in the-P0 3 HR group of the first copolymer, it is preferably 1-10 carbon alkyl such as methyl, propyl, amyl or hexyl. Most preferably, alkyl is 1-4 carbon alkyl.
  • the first carrier-soluble copolymer is believed to function as a charge-control agent and the second as a charging agent.
  • the charge of the developer per unit mass is further stabilized against change when the toner contains a neutral or basic pigment.
  • the liquid carrier employed in a developer of the invention has a low electric constant and a high electrical resistance such that it will not disturb or destroy the electrostatic charge pattern being developed.
  • Carrier liquids should have a dielectric constant of less than about 3, have a volume resistivity greater than 10 10 ohm-cm and be chemically stable.
  • Suitable carrier liquids include halogenated hydrocarbon solvents such as trichlorotrifluoroethane; hydrocarbon solvents are useful, such as isoparaffinic hydrocarbons and cyclohydrocarbons such as cyclohexane.
  • the liquid carrier is a combination of two different electrically insulating liquids.
  • Toner is dispersed in the carrier and serves as the marking particle constituent which is attracted to an electrostatic charge image on an element being developed.
  • the toner comprises a colorant and a binder polymer, if necessary, for adhesion of the colorant to the image-bearing element.
  • Colorants can be selected from one or more of a variety of dyes and pigments. Carbon black is a preferred colorant, but virtually any of the compounds in the "Colour Index", Second Edition, 1956, Volumes I and II, may, in principle, be used.
  • Preferred toners comprise neutral or basic pigments such as neutral or basic carbon black pigments.
  • the neutrality or basicity of a pigment is determined as the pH of the pigment by the ASTM D 1512-60(76) method, details of which are reported in the "Analysis of Carbon Black” by B. Schubert et al, Encyclopedia of Industrial ChemicalAnalysis, Volume B (reprint pages 51-52, pH), John Wiley and Sons, Inc.
  • Neutral or basic pigments according to this method exhibit a pH of 7 and higher.
  • Binder polymers which can be employed with the toner particles, if desired, include a variety of materials such as halogenated polyolefins, addition polymers such as acrylic polymers and condensation polymers.
  • halogenated polyolefins such as halogenated polyolefins
  • addition polymers such as acrylic polymers and condensation polymers.
  • polyesterionomers such as disclosed in US Patent 4,252,921.
  • the developer of the present invention includes, as a charge-control agent, a carrier-soluble addition copolymer.
  • Carrier-soluble refers to its ability to dissolve in the electrically insulating carrier, in the absence of the toner constituents, at the concentration level at which it is employed in the developer.
  • the monomer constituents of the polymer include at least the following: a quaternary ammonium salt monomer, a solubilizing monomer, and a monomer having an acidic function selected from the group consisting of -COOH, -S0 3 H and -P0 3 HR.
  • Suitable quaternary ammonium salt monomers include:
  • solubilizing monomers include the following: alkylstyrenes and alkoxystyrenes having 3 to 10 carbon atoms in the alkyl group; alkyl acrylates and methacrylates having 8 to 22 carbon atoms in the alkyl group; vinyl alkyl ethers having 8 to 22 carbon atoms in the alkyl group; and vinyl esters of alkanoic acids having 6 to 22 carbon atoms in the alkyl group.
  • solubilizing monomers which can be so used include: t-butylstyrene, 4-pentylstyrene, 4-hexylstyrene, 4-octylstyrene, p-amyloxystyrene, lauryl acrylate, lauryl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, eicosyl acrylate, docosyl methacrylate, vinyl caprate, vinyllaurate, vinyl palmitate, vinyl stearate, vinyl eicosate and vinyl docosate.
  • Suitable insolubilizing monomers having an acidic function include addition polymerizable polymers such as olefinic and acrylic monomers having the requisite acidic function.
  • Representative acidic monomers include:
  • the charge control polymer set forth above can include additional other monomers to adjust, for example, the degree of solubility of the polymer in the carrier, as well as to provide other desirable properties.
  • Quaternary ammonium salt polymers useful in the liquid developers of this invention typically have an inherent viscosity in the range from 0.1 to 0.8. The determination is made at a concentration of 0.25 gram of polymer in 100 ml of chloroform at a temperature of 25°C.
  • the resultant polymers contain recurring units derived from one or more solubilizing monomers, from one or more quaternary ammonium salt monomers and from one or more insolubilizing acidic monomers.
  • a typical quaternary ammonium salt copolymer used in the liquid developers of the invention contains from 85 to 97 mole percent of solubilizing monomer units, from 10 to 2 mole percent acidic insolubilizing monomer units, and from 5 to 1 mole percent of quaternary ammonium salt monomer units.
  • the solubility of the quaternary ammonium salt copolymer in the carrier liquid can be controlled by adjusting the amount of solubilizing and insolubilizing (acidic) monomers which are used. If the solubilizing monomer has a relatively long alkyl group, rendering a polymer containing it very soluble in hydrocarbon carrier liquids, the insolubilizing monomer may have a relatively short alkyl group. On the other hand, a relatively short alkyl group on the solubilizing monomer requires a somewhat longer alkyl group on the insolubilizing monomer.
  • the relative amount of quaternary ammonium salt monomer can be varied to provide polymers having different charge properties. when incoporated into a liquid developer.
  • the developer of the present invention also contains, as a charging agent, a carrier-soluble polar addition copolymer of the type disclosed in US Patents 4,273,849 and 3,849,165.
  • carrier-soluble refers to the ability of the charging copolymer to dissolve in the liquid carrier, in the absence of the toner constituents, at the concentration level which is employed in the developer.
  • the soluble polar copolymer is an addition copolymer of a polar monomer and at least one solubilizing monomer.
  • the amount of polar monomer is at least 1.5x 10- 4 moles/gm of copolymer. It is preferred for the solubilizing monomer to be present to the extent of at least 35 weight % and for the polar monomer to be present in an amount not in excess of 20 weight %, based on the weight of this copolymer.
  • Monomers for addition copolymerizing with the polar monomer to obtain a soluble polar copolymer are the solubilizing monomers previously described and, if desired, insolubilizing monomers such as styrene, vinyl toluene, ethyl acrylate, methyl acrylate, butyl acrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, vinyl acetate, vinyl propionate and vinyl butyrate, as described by Stahly et al, US Patent 3,849,165.
  • the relative amounts of the comonomers are selected to produce a polar addition copolymer of the desired solubility, as described above with respect to the quaternary ammonium salt copolymers.
  • Suitable polar monomers include sulfoalkyl acrylates and methacrylates, metal salts of sulfoalkyl acrylates and methacrylates, and amine salts of sulfoalkyl acrylates and methacrylates.
  • the sulfoalkyl groups contain from 1 to about 4 carbon atoms.
  • metal salts and amine salts of acrylic and methacrylic acids and of vinylbenzoic acid, vinylphenylacetic acid, 9(10)-acrylamidostearic acid, monoalkylphthalic acid, and styrenesulfonic acid, the metals of said salts being from Groups I, Ila, Ilb and VIII of the periodic table, and mixtures thereof.
  • Preferred polar monomers are acrylic monomers.
  • the term "acrylic” broadly includes methacrylic, and salts and esters of such accrylic, acids.
  • acrylic polar monomers include sulfoethyl methacrylate; sulfoethyl acrylate; sulfopropyl methacrylate; sulfobutyl methacrylate; sulfoethyl methacrylate, sodium salt; sulfoethyl methacrylate, partial sodium salt; sulfopropyl methacrylate, sodium salt; sulfobutyl methacrylate, potassium salt; sulfoethyl methacrylate, lithium salt; sulfoethyl methacrylate, copper salt; sulfopropyl methacrylate, dimethylammonium salt; sulfoethyl methacrylate diethylammonium salt; sulfomethyl acrylate, dimethylammonium salt; sodium methacrylate; sodium acrylate; lithium methacrylate; potassium acrylate; barium methacrylate; zinc meth
  • the liquid electrographic developers of this invention preferably contain from 0.01 percent to 5 percent by weight of soluble polar copolymer, from 0.01 percent to 5 percent by weight of quaternary ammonium salt copolymer, and from 0.01 percent to 5 percent by weight of toner.
  • Preferred developers contain from 0.02 percent to 0.5 percent by weight of the soluble acrylic polar copolymer, from 0.02 percent to 0.5 percent by weight quaternary ammonium salt copolymer, and from 0.02 percent to 0.5 percent by weight toner.
  • Replenishability R is defined for the purpose of the present invention as the ratio of initial charge/mass to final charge/mass after a 1/2 liter reservoir of the developer has been employed to form a electrographic images and replenished.
  • the extent of imaging and replenishment was predetermined so as to use and replenish three times the number of marking particles in the original developer. (For example, if the developer contains 0.2 gram toner, 0.6 gram is developed and replenished.)
  • the replenisher employed as a 5x concentrate of the original developer.
  • the charge before and after in coulombs was measured with a Keithly Instruments Capacitance Bridge (available from Teltex Instruments, Inc., Pennsylvania). The charge measured is divided by the toner weight in kilograms to give charge per mass in coulombs per kilogram toner.
  • the following developer components were employed in an Isopar G -Solvesso 100 liquid carrier system with a pigment concentration of 0.7 gram per liter developer.
  • Solvesso 100 is a trademark for an alkylated aromatic liquid and Isopar G is a trademark for an isoparaffinic hydrocarbon liquid.
  • the solvesso 100 concentration was approximately 21 grams per liter of developer.
  • Each of the developers also contained 0.5 part plasticizer, 0.25 part wax and 0.125 part dispersing agent for the wax.
  • the developer of the invention corresponded to Developer A above.
  • the charge-control polymer employed in the control developer was either (a) an addition terpolymer of a solubilizing monomer, an insolubilizing monomer which contained no acidic groups and a quaternary ammonium monomer or (b) an addition copolymer of a monomer and a quaternary ammonium polymer.
  • the control developers and developers of the invention were identical.
  • Examples 1-4 The procedure of Examples 1-4 was repeated employing developer A with either Raven 1255@ carbon black, which was neutralized by washing, or neutral Regal 300@ carbon black.
  • concentration of addition polar copolymer and quaternary ammonium charge-control polymer was also varied as indicated.
  • Electrography and electrophotography as used herein are broad terms which include image-forming processes involving the development of an electrostatic charge pattern formed on a surface with or without light exposure, and thus include electrophotography and other processes.

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

Claims (11)

1. Composition de révélateur électrographique liquide comprenant un porteur liquide isolant de l'électricité qui contient des particules de révélateur dispersées et dans lequel sont dispersés de façon uniforme au moins deux copolymères d'addition, les copolymères dispersés comprenant un premier copolymère soluble dans le porteur comme agent de contrôle de charge composé de motifs d'un monomère sel d'ammonium quaternaire et de motifs d'un monomère solubilisant, et un deuxième copolymère soluble dans le porteur comme agent de charge composé de motifs de monomère polaire et de motifs de monomère solubilisant, caractérisé en ce que le premier copolymère contient de plus des motifs d'un monomère insolubilisant ayant une fonction acide de formule -COOH, -S03H ou -P03HR, où R est un atome d'hydrogène ou un groupe alkyle.
2. Révélateur selon la revendication 1 dans lequel ledit monomère insolubilisant à caractère acide est l'acide acrylique, l'acide méthacrylique, l'acide vinylbenzoïque, l'acide styrène acétique, le sulfoéthyl méthacrylamide, le méthacrylate de sulfoéthyle, l'acide styrène sulfonique, le vinylbenzyléthylphosphate, l'acide vinylbenzylphosphonique, l'acide vinylphosphonique ou le vinyléthylphosphonate.
3. Révélateur selon la revendication 1 ou 2 où les monomères solubilisants dans les copolymères dispersés sont choisis parmi le t-butylstyrène, le 4-pentylstyrène, le 4-hexylstyrène, le 4-octylstyrène, le p-amyloxystyrène, l'acrylate de lauryle, le méthacrylate de lauryle, le méthacrylate d'hexadécyle, le méthacrylate d'octadécyle, l'acrylate d'eicosyle, le méthacrylate de docosyle, le caprate de vinyle, le laurate de vinyle, le palmitate de vinyle, le stéarate de vinyle, l'eicosenate de vinyle et le docosanoate de vinyle.
4. Révélateur selon l'une quelconque des revendications précédentes dans lequel le monomère sel d'ammonium quaternaire du premier copolymère soluble dans le porteur est choisi parmi le p-toluène sulfonate de métacryloyloxyéthyltriméthylammonium, le chlorure de diméthyloctadécylvinylbenzyl- ammonium, le méthylsulfate de 2 - vinyl - N - méthylpyridinium, le bromure de N - méthyl - N - méthacryloyloxyéthyl piperidinium et le nitrate de N - méthacryloyloxyéthylpyridinium.
5. Révélateur selon l'une quelconque des revendications précédentes dans lequel le monomère polaire du deuxième copolymère soluble est choisi parmi le méthacrylate de sulfoéthyle, l'acrylate de sulfoéthyle, le méthacrylate de sulfopropyle, le méthacrylate de sulfobutyle, le sel de sodium du méthacrylate de sulfoéthyle, le sel partiel de sodium du méthacrylate de sulfoéthyle, le sel de sodium du méthacrylate de sulfopropyle, le sel de potassium du méthacrylate de sulfobutyle, le sel de lithium du méthacrylate de sulfoéthyle, le sel de cuivre du méthacrylate de sulfoéthyle, le sel de diméthylammonium du méthacrylate de sulfopropyle, le sel de diéthylammonium du méthacrylate de sulfoéthyle, le sel de diméthylammonium d'acrylate de sulfométhyle, le méthacrylate de sodium, l'acrylate de sodium, le méthacrylate de lithium, l'acrylate de potassium, le méthacrylate de baryum, le méthacrylate de zinc, le méthacrylate de cobalt, l'acrylate ferreux, le méthacrylate de magnésium, et l'acrylate de zinc.
6. Révélateur selon l'une quelconque des revendications précédentes dans lequel les concentrations en particules de révélateur, en premier copolymère soluble dans le porteur et en deuxième copolymère soluble dans le porteur sont chacune comprises entre 0,01 et 5 pour cent en poids par rapport au poids total du révélateur.
7. Révélateur selon la revendication 6 dans lequel lesdites concentrations sont toutes comprises entre 0,02 et 0,5 pour cent en poids par rapport au poids total du révélateur.
8. Révélateur selon l'une quelconque des revendications précédentes dans lequel les particules de révélateur comprennent un colorant de pH neutre ou basique.
9. Révélateur selon la revendication 8 dans lequel les particules de révélateur comprennent de plus un polyesterionomère comme liant du colorant.
10. Révélateur selon l'une quelconque des revendications précédentes dans lequel le porteur comprend un deuxième liquide isolant de l'électricité.
11. Revélateur selon la revendication 10 dans lequel le liquide porteur isolant de l'électricité est un mélange de liquide hydrocarboné isoparaffinique et de liquide aromatique alkylé.
EP19840300812 1983-02-11 1984-02-09 Développateurs électrographiques liquides Expired EP0119713B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US46574783A 1983-02-11 1983-02-11
US465747 1983-02-11

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EP0119713A1 EP0119713A1 (fr) 1984-09-26
EP0119713B1 true EP0119713B1 (fr) 1987-10-07

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EP (1) EP0119713B1 (fr)
JP (1) JPS59157658A (fr)
CA (1) CA1212854A (fr)
DE (1) DE3466743D1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0176630B1 (fr) * 1984-10-02 1988-05-04 Agfa-Gevaert N.V. Révélateur liquide pour le développement d'images électrostatiques
DE3473185D1 (en) * 1984-10-02 1988-09-08 Agfa Gevaert Nv Liquid developer for development of electrostatic images
US4681831A (en) * 1986-06-30 1987-07-21 E. I. Du Pont De Nemours And Company Chargeable resins for liquid electrostatic developers comprising partial ester of 3-hydroxypropanesulfonic acid
GB0019415D0 (en) * 2000-08-09 2000-09-27 Ciba Spec Chem Water Treat Ltd Noval monomers, polymers thereof and the use of the polymers
JP4269010B2 (ja) * 2001-07-09 2009-05-27 学校法人日本大学 歯科用セルフエッチングプライマー処理剤

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3788995A (en) * 1971-06-03 1974-01-29 Eastman Kodak Co Liquid electrographic developers
US3849165A (en) * 1971-06-03 1974-11-19 Eastman Kodak Co Liquid electrographic development process
JPS50147722A (fr) * 1974-05-17 1975-11-27
DE2642826C3 (de) * 1976-09-23 1982-03-11 Philip A. Hunt Chemical Corp., Palisades Park, N.J. Elektrostatographischer Suspensionsentwickler
JPS5369635A (en) * 1976-12-02 1978-06-21 Ricoh Co Ltd Liquid developing agent for use in static photography
JPS5431739A (en) * 1977-08-12 1979-03-08 Eastman Kodak Co Negatively charged liquid developer for electrophotography
US4273849A (en) * 1978-08-11 1981-06-16 Eastman Kodak Company Method of using liquid electrographic developers containing polymeric quaternary salts
US4252921A (en) * 1979-10-03 1981-02-24 Eastman Kodak Company Polyesterionomers having utility in liquid electrographic developer compositions

Also Published As

Publication number Publication date
EP0119713A1 (fr) 1984-09-26
JPS59157658A (ja) 1984-09-07
CA1212854A (fr) 1986-10-21
DE3466743D1 (en) 1987-11-12

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