US3503881A - Liquid developer for electrophotography - Google Patents
Liquid developer for electrophotography Download PDFInfo
- Publication number
- US3503881A US3503881A US650565A US3503881DA US3503881A US 3503881 A US3503881 A US 3503881A US 650565 A US650565 A US 650565A US 3503881D A US3503881D A US 3503881DA US 3503881 A US3503881 A US 3503881A
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- US
- United States
- Prior art keywords
- liquid developer
- electrophotography
- developing agent
- particulate
- liquid
- 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 - Lifetime
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Classifications
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- 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
- G03G9/087—Binders for toner particles
- G03G9/08784—Macromolecular material not specially provided for in a single one of groups G03G9/08702 - G03G9/08775
- G03G9/08786—Graft polymers
-
- 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
- This invention relates to a novel liquid developer to be used for wet development in electrophotography, and further relates to a liquid developer featuring in dispersion a graft-polymer to be used as the particulate developing agent, comprising a pigment and a polarization-control agent having excellent dispersibility in the liquid.
- liquid developers commonly used at present, it is diflicult to achieve constant performance as a polarization control agent, because it is derived from naturally occurring materials such as rosin and asphalt. The variations in composition and property of such a natural material would not exist in a manufactured product.
- the dispersibility becomes inferior, and this results in coagulation and precipitation of the particulate developing agent and, therefore causes the development capacity to be lowered, and the image developed to lack sharpness.
- the deterioration in dispersibility and other defects are believed to result from the fact that the particulate developing agent exists in the liquid in a form to cause the particulate pigment dispersed in the solvent to attract the molecule of polarization control agent in the commencing period of use, so that stabilized dispersion is maintained during this period, but that after repeated use for long term, the dissolved matter separated from the photoconductive layer of the photosenstive material accumulates, or the molecule of polarization control agent gradually escapes from the particulate pigment owing to the charge of liquid.
- the liquid developer of the present invention to be used for electrophotography is a research result achieved after doing wide investigations aimed as improvement in dispersibility and stabilization of particulate developing agent contained in the liquid developer. This does not, at all, use the naturally occurring materials such as rosin and asphalt, and is entirely different from the existing developers, and is an entirely new improved type, having no such defects as mentioned above, and involving the dispersion into the liquid of particulate developing agent obtained by the direct chemical combination of polarization control agent with the pigment.
- the monomer of acrylate ester having the following formula is polymerized after kneading with carbon black, initiator of the polymerization reaction, and with benzene, and the particulate developing agent which is formed by the reaction and is in a form having graft-polymerized monomer of acrylate ester onto the particulate carbon, is directly dispersed into parafiinc organic solvent heretofore used for such purposes, to prepare the developer of this invention.
- R is H, CH or C H and 2 is s w C8H1'I: 10 21 12 25: r 14 29
- styrene or butyl acrylate etc. the obtained product was, at all, unusable for the purpose as the liquid devloper.
- the liquid developer to be used in this invention is that illustrated in the foregoing, but the mechanism of the graft-polymerization is not yet clarified at present. Anyhow, this graft polymer of carbon-acrylate ester could become sharply charged developing agent particles by itself when dispersed inordinary parafiinic solvent, and the dispersibility in the dispersed liquid is quite excellent and displays stabilized development capability even after long term use of the liquid developer. Accordingly, the liquid developer of the present invention could have constant quality which comes from nature of the synthesized raw materials, and furthermore, this does not require various additives as was used in conventional manufacture. However, to obtain further increased sharpness of the image using this developer, the concurrent use of small amount of higher fatty acid or metallic soap is effective.
- EXAMPLE 1 A 10 gram of lauryl acrylate, 10 gram of carbon black (from Mitsubishi Chemical Company, #44), 0.21 gram of azobisisobutylonitrile (being initiator), and 6.5 gram of benzene were mixed and kneaded, then put into polymerization tube followed by freezing, and degasified under reduced pressure, and was sealed. This was then shaken for 8 hours at 60 deg. C. in the polymerization tank of shaking type. Then, 0.5 gram of the reaction product was put into mortar together with 5 gram of toluene, and after well kneading, this was dispersed into 500 cc.
- the particulate developing agent of the liquid developer showed stabil- Carbon Azobis Black Benzene isobutyl- (g.) Monomer (g.) (g.) onltrile (g.)
- EXAMPLE 2 A 0.5 gram of polymerized product obtained in the former example was kneaded together with grams of toluene, and followed by further addition and kneading with 0.5 gram of 1 percent in toluene solution of aluminum monostearate. This was dispersed into into 500 cc. of isoparafiinic hydrocarbon (lsopar H), thus obtaining liquid developer. Photosensitive material of electrophotography having latent image was immersed into the liquid developer, and P/ P type image was obtained which was more sharpened than the former example.
- lsopar H isoparafiinic hydrocarbon
- a liquid developer for use in electrophotography comprising a dispersion of particulate developing agent in parafiinic hydrocarbon solvent, said particulate developing agent is composed of reaction product made by graft-polymerization to carbon black with an acrylate ester indicated by the following formula, where;
- a liquid developer for use in electrophotography comprising a dispersion of particulate developing agent and a small amount of a metallic soap, into parafiinic hydrocarbon solvent, said particulate developing agent composed of reaction product made by graftpolymerization to carbon black with an acrylate ester indicated by the following formula, where; R1 is H, CH3 01' 021-15; and R2 iS C6H13', I'I 'I, C10H21, C12II25, 01' CMHZQ.
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- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- General Physics & Mathematics (AREA)
- Liquid Developers In Electrophotography (AREA)
Description
United States Patent 3,503,881 LIQUID DEVELOPER FOR ELECTROPHOTOGRAPHY Isao Shinohara, Eishun Tsuchida, Toshinao Goto, Zenjiro Okuno', Isao Tashiro, Eiichi Kawamura, and Makoto Nakamura, Tokyo, and Kenkichi Muto, Yokohama,
Japan, 'assignors to Kabushiki Kaisha Ricoh, Tokyo,
Japan, a corporation of Japan No Drawing." Filed June 20, 1967, Ser. No. 650,565
Int. Cl. G03g 9/06 U.S. Cl. 252-62.1 I 2 Claims This invention relates to a novel liquid developer to be used for wet development in electrophotography, and further relates to a liquid developer featuring in dispersion a graft-polymer to be used as the particulate developing agent, comprising a pigment and a polarization-control agent having excellent dispersibility in the liquid.
There are two existing methods for development of electrophotography, namely dry method and wet method; the former employs spreading of dry powdered developing agent on the surface of the latent image; the latter employs wet development by the soaking of sensitized material intoa liquid developer, in which a developing agent is dispersed in an appropriate solvent. The liquid developer to be used in the wet development method is made from pigment and polarization-control agent by kneading them together into paste, followed by the dispersion of the mixture in an appropriatesolvent. Up to the present time, many and various developing agents for use of electrophotography have been proposed; however, commonly used was a rosin, an alkyd resin, and asphalt etc. for dispersing the pigment and for use as a polarization control agent, and a paraffinic hydrocarbon for use as the dispersion medium.
With liquid developers commonly used at present, it is diflicult to achieve constant performance as a polarization control agent, because it is derived from naturally occurring materials such as rosin and asphalt. The variations in composition and property of such a natural material would not exist in a manufactured product. In addition, when the developer is used for long term, the dispersibility becomes inferior, and this results in coagulation and precipitation of the particulate developing agent and, therefore causes the development capacity to be lowered, and the image developed to lack sharpness. The deterioration in dispersibility and other defects are believed to result from the fact that the particulate developing agent exists in the liquid in a form to cause the particulate pigment dispersed in the solvent to attract the molecule of polarization control agent in the commencing period of use, so that stabilized dispersion is maintained during this period, but that after repeated use for long term, the dissolved matter separated from the photoconductive layer of the photosenstive material accumulates, or the molecule of polarization control agent gradually escapes from the particulate pigment owing to the charge of liquid.
v The liquid developer of the present invention to be used for electrophotography is a research result achieved after doing wide investigations aimed as improvement in dispersibility and stabilization of particulate developing agent contained in the liquid developer. This does not, at all, use the naturally occurring materials such as rosin and asphalt, and is entirely different from the existing developers, and is an entirely new improved type, having no such defects as mentioned above, and involving the dispersion into the liquid of particulate developing agent obtained by the direct chemical combination of polarization control agent with the pigment. In the liquid developer of the present invention, the monomer of acrylate ester having the following formula is polymerized after kneading with carbon black, initiator of the polymerization reaction, and with benzene, and the particulate developing agent which is formed by the reaction and is in a form having graft-polymerized monomer of acrylate ester onto the particulate carbon, is directly dispersed into parafiinc organic solvent heretofore used for such purposes, to prepare the developer of this invention. In the formula, R is H, CH or C H and 2 is s w C8H1'I: 10 21 12 25: r 14 29 As will be exemplified later for purposes of contrasted comparison in the case of polymerization of carbon black with substances other than acrylate ester as presented by the foregoing general formula, for instance, styrene or butyl acrylate etc., the obtained product was, at all, unusable for the purpose as the liquid devloper.
The liquid developer to be used in this invention is that illustrated in the foregoing, but the mechanism of the graft-polymerization is not yet clarified at present. Anyhow, this graft polymer of carbon-acrylate ester could become sharply charged developing agent particles by itself when dispersed inordinary parafiinic solvent, and the dispersibility in the dispersed liquid is quite excellent and displays stabilized development capability even after long term use of the liquid developer. Accordingly, the liquid developer of the present invention could have constant quality which comes from nature of the synthesized raw materials, and furthermore, this does not require various additives as was used in conventional manufacture. However, to obtain further increased sharpness of the image using this developer, the concurrent use of small amount of higher fatty acid or metallic soap is effective.
This invention can be understood better by the detail EXAMPLE 1 A 10 gram of lauryl acrylate, 10 gram of carbon black (from Mitsubishi Chemical Company, #44), 0.21 gram of azobisisobutylonitrile (being initiator), and 6.5 gram of benzene were mixed and kneaded, then put into polymerization tube followed by freezing, and degasified under reduced pressure, and was sealed. This was then shaken for 8 hours at 60 deg. C. in the polymerization tank of shaking type. Then, 0.5 gram of the reaction product was put into mortar together with 5 gram of toluene, and after well kneading, this was dispersed into 500 cc. of isoparafiinic hydrocarbon solvent (Isopar H), thus obtaining liquid developer for the use. The particulate developing agent of the liquid developer showed stabil- Carbon Azobis Black Benzene isobutyl- (g.) Monomer (g.) (g.) onltrile (g.)
A 1O 10 acrylic acid 23. 2 0. 73
B 10 5 acrylic acid .4- 11. 6 0. 37
C 10 10 butyl acrylate 12. 2 O. 38
D 10 10 styrene 15. 0. 47
EXAMPLE 2 A 0.5 gram of polymerized product obtained in the former example was kneaded together with grams of toluene, and followed by further addition and kneading with 0.5 gram of 1 percent in toluene solution of aluminum monostearate. This was dispersed into into 500 cc. of isoparafiinic hydrocarbon (lsopar H), thus obtaining liquid developer. Photosensitive material of electrophotography having latent image was immersed into the liquid developer, and P/ P type image was obtained which was more sharpened than the former example.
What we claim is:
1. A liquid developer for use in electrophotography comprising a dispersion of particulate developing agent in parafiinic hydrocarbon solvent, said particulate developing agent is composed of reaction product made by graft-polymerization to carbon black with an acrylate ester indicated by the following formula, where;
1 is CH3 0r z s; and R3. i E 13: vC8 11? CIOHZI, 12 25, or 14 29- v 1 CH2=C 2. A liquid developer for use in electrophotography comprising a dispersion of particulate developing agent and a small amount of a metallic soap, into parafiinic hydrocarbon solvent, said particulate developing agent composed of reaction product made by graftpolymerization to carbon black with an acrylate ester indicated by the following formula, where; R1 is H, CH3 01' 021-15; and R2 iS C6H13', I'I 'I, C10H21, C12II25, 01' CMHZQ.
COORQ References Cited UNITED STATES PATENTS 9/1966 Russell 106 3'.s
GEORGE F. LESMES, Primary Examiner J. P. BRAMMER, Assistant Examiner U.S. c1. X.R.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 35 3 Dated March 3 97 Isao Shinohara, Eishun Tsuchida, Toshinao Goto,
I sll Makoto Nakamura, and Kenkichi Muto It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Inventor(s) Column 4, line 14, after-"CH insert line 14, the formula reading "C H shoul read (3 H SIGNED AND SEALED JUL 2 8 1970 Aunt:
Edwin! n. Fletch I mm m o fi oomiasione'r of Pawn-t! USCOMM-DC COSTS-P69 FORM PO-105O (10-69) u.s oovumnim mnmur. orncc 1 ml o-au-Ju
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US65056567A | 1967-06-20 | 1967-06-20 |
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US3503881A true US3503881A (en) | 1970-03-31 |
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US650565A Expired - Lifetime US3503881A (en) | 1967-06-20 | 1967-06-20 | Liquid developer for electrophotography |
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Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3623986A (en) * | 1967-08-04 | 1971-11-30 | Ricoh Kk | Liquid developer for use in electrophotography |
US3639243A (en) * | 1966-11-21 | 1972-02-01 | Ricoh Kk | Liquid developer electrophotography |
US3639244A (en) * | 1967-05-15 | 1972-02-01 | Ricoh Kk | Liquid developer for use in electrophotography |
US3668127A (en) * | 1968-07-01 | 1972-06-06 | Ricoh Kk | Liquid developer for electrophotography |
US3753760A (en) * | 1970-01-30 | 1973-08-21 | Hunt P | Liquid electrostatic development using an amphipathic molecule |
US3870644A (en) * | 1969-02-10 | 1975-03-11 | Ricoh Kk | Liquid developer for plural-color electrophotography |
US3968044A (en) * | 1974-02-01 | 1976-07-06 | Rank Xerox Ltd. | Milled liquid developer |
US4019993A (en) * | 1970-10-21 | 1977-04-26 | Fuji Photo Film Co., Ltd. | Manufacturing process for liquid developer |
US4033890A (en) * | 1975-02-26 | 1977-07-05 | Fuji Photo Film Co., Ltd. | Liquid developer for electrophotography |
US4104183A (en) * | 1975-12-24 | 1978-08-01 | Ricoh Co., Ltd. | Liquid developer for use in electrostatic photography comprising natural resins and natural resin-modified thermosetting resins combined with polymers |
US4116698A (en) * | 1975-12-19 | 1978-09-26 | Ricoh Co., Ltd. | Ferrocyanate treating liquid for offset master |
US5407771A (en) * | 1984-12-10 | 1995-04-18 | Indigo N.V. | Toner and liquid composition using same |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB859292A (en) * | 1957-12-05 | 1961-01-18 | Crylor | Vinyl and vinylidene polymers pigmented with carbon black |
GB869391A (en) * | 1960-03-30 | 1961-05-31 | Nat Lead Co | Composite carbon-polymer compositions and process of manufacture |
US3272772A (en) * | 1961-08-30 | 1966-09-13 | Dow Chemical Co | Filled polymer compositions |
US3385808A (en) * | 1963-11-14 | 1968-05-28 | Bayer Ag | Dry pigment compositions of dyeing plastics |
-
1967
- 1967-06-20 US US650565A patent/US3503881A/en not_active Expired - Lifetime
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB859292A (en) * | 1957-12-05 | 1961-01-18 | Crylor | Vinyl and vinylidene polymers pigmented with carbon black |
GB869391A (en) * | 1960-03-30 | 1961-05-31 | Nat Lead Co | Composite carbon-polymer compositions and process of manufacture |
US3272772A (en) * | 1961-08-30 | 1966-09-13 | Dow Chemical Co | Filled polymer compositions |
US3385808A (en) * | 1963-11-14 | 1968-05-28 | Bayer Ag | Dry pigment compositions of dyeing plastics |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3639243A (en) * | 1966-11-21 | 1972-02-01 | Ricoh Kk | Liquid developer electrophotography |
US3639244A (en) * | 1967-05-15 | 1972-02-01 | Ricoh Kk | Liquid developer for use in electrophotography |
US3623986A (en) * | 1967-08-04 | 1971-11-30 | Ricoh Kk | Liquid developer for use in electrophotography |
US3668127A (en) * | 1968-07-01 | 1972-06-06 | Ricoh Kk | Liquid developer for electrophotography |
US3870644A (en) * | 1969-02-10 | 1975-03-11 | Ricoh Kk | Liquid developer for plural-color electrophotography |
US3753760A (en) * | 1970-01-30 | 1973-08-21 | Hunt P | Liquid electrostatic development using an amphipathic molecule |
US4019993A (en) * | 1970-10-21 | 1977-04-26 | Fuji Photo Film Co., Ltd. | Manufacturing process for liquid developer |
US3968044A (en) * | 1974-02-01 | 1976-07-06 | Rank Xerox Ltd. | Milled liquid developer |
US4033890A (en) * | 1975-02-26 | 1977-07-05 | Fuji Photo Film Co., Ltd. | Liquid developer for electrophotography |
US4116698A (en) * | 1975-12-19 | 1978-09-26 | Ricoh Co., Ltd. | Ferrocyanate treating liquid for offset master |
US4104183A (en) * | 1975-12-24 | 1978-08-01 | Ricoh Co., Ltd. | Liquid developer for use in electrostatic photography comprising natural resins and natural resin-modified thermosetting resins combined with polymers |
US5407771A (en) * | 1984-12-10 | 1995-04-18 | Indigo N.V. | Toner and liquid composition using same |
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