US3714048A - Electrophotographic liquid developer containing asphalt and modified alkyl resin - Google Patents
Electrophotographic liquid developer containing asphalt and modified alkyl resin Download PDFInfo
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- US3714048A US3714048A US00076307A US3714048DA US3714048A US 3714048 A US3714048 A US 3714048A US 00076307 A US00076307 A US 00076307A US 3714048D A US3714048D A US 3714048DA US 3714048 A US3714048 A US 3714048A
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- United States
- Prior art keywords
- asphalt
- liquid developer
- coloring material
- resin
- organic solvent
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- Expired - Lifetime
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- 239000010426 asphalt Substances 0.000 title claims abstract description 36
- 239000007788 liquid Substances 0.000 title claims abstract description 26
- 229920005989 resin Polymers 0.000 title claims description 12
- 239000011347 resin Substances 0.000 title claims description 12
- 125000000217 alkyl group Chemical group 0.000 title 1
- 238000004040 coloring Methods 0.000 claims abstract description 33
- 239000002245 particle Substances 0.000 claims abstract description 32
- 239000000463 material Substances 0.000 claims abstract description 28
- 239000003960 organic solvent Substances 0.000 claims abstract description 20
- 239000006185 dispersion Substances 0.000 claims abstract description 13
- 238000002360 preparation method Methods 0.000 claims abstract description 8
- 229920000180 alkyd Polymers 0.000 claims description 6
- 239000000049 pigment Substances 0.000 claims description 6
- 239000011343 solid material Substances 0.000 claims description 5
- 239000002904 solvent Substances 0.000 claims description 5
- 150000004945 aromatic hydrocarbons Chemical class 0.000 claims description 4
- 239000000975 dye Substances 0.000 claims description 4
- 229920003002 synthetic resin Polymers 0.000 abstract description 29
- 239000000057 synthetic resin Substances 0.000 abstract description 29
- 238000007639 printing Methods 0.000 description 11
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 9
- 239000007787 solid Substances 0.000 description 9
- 239000000203 mixture Substances 0.000 description 4
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 4
- 238000010521 absorption reaction Methods 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 229910052500 inorganic mineral Inorganic materials 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000000693 micelle Substances 0.000 description 3
- 239000011707 mineral Substances 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 230000004304 visual acuity Effects 0.000 description 3
- 239000001293 FEMA 3089 Substances 0.000 description 2
- 241000779819 Syncarpia glomulifera Species 0.000 description 2
- 239000003463 adsorbent Substances 0.000 description 2
- 230000000274 adsorptive effect Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- XCJYREBRNVKWGJ-UHFFFAOYSA-N copper(II) phthalocyanine Chemical compound [Cu+2].C12=CC=CC=C2C(N=C2[N-]C(C3=CC=CC=C32)=N2)=NC1=NC([C]1C=CC=CC1=1)=NC=1N=C1[C]3C=CC=CC3=C2[N-]1 XCJYREBRNVKWGJ-UHFFFAOYSA-N 0.000 description 2
- 230000005669 field effect Effects 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 239000003350 kerosene Substances 0.000 description 2
- 229940107698 malachite green Drugs 0.000 description 2
- FDZZZRQASAIRJF-UHFFFAOYSA-M malachite green Chemical compound [Cl-].C1=CC(N(C)C)=CC=C1C(C=1C=CC=CC=1)=C1C=CC(=[N+](C)C)C=C1 FDZZZRQASAIRJF-UHFFFAOYSA-M 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 239000003208 petroleum Substances 0.000 description 2
- 239000001739 pinus spp. Substances 0.000 description 2
- HJWLCRVIBGQPNF-UHFFFAOYSA-N prop-2-enylbenzene Chemical compound C=CCC1=CC=CC=C1 HJWLCRVIBGQPNF-UHFFFAOYSA-N 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229940036248 turpentine Drugs 0.000 description 2
- 235000010469 Glycine max Nutrition 0.000 description 1
- 244000068988 Glycine max Species 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000004931 aggregating effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000000084 colloidal system Substances 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000003085 diluting agent Substances 0.000 description 1
- 239000002612 dispersion medium Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000007645 offset printing Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 150000003505 terpenes Chemical class 0.000 description 1
- 235000007586 terpenes Nutrition 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
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
Definitions
- This invention relates to an electrophotgraphic liquid developer, particularly available for the preparation of lithographic plates.
- toner particles should have characteristics which satisfy the following prerequisites;
- Toner particles should carry a stable positive charge.
- the fringing field effect should appear least and accordingly, good tone reproduction of the photograph or of the solid area whereon toner particles should completely be deposited, is obtainable.
- the object of the present invention is to obviate the above-mentioned defects present in the conventional lithographic processes and accordingly, to provide an electrophotographic liquid developer useful for the preparation of lithographic plates which have the characteristics satisfying the above-listed prerequisites.
- an electrophotographic liquid developer useful for the preparation of lithographic plates comprising a uniform dispersion of at least one coloring material (pigment or dyestuff) in particle form asphalt and synthetic resin, selected from petroleum resin and oil modified synthetic resin in an organic solvent having an electrical resistance of no less than lO Qcm, said synthetic resin being at least partially soluble in the organic solvent.
- at least one coloring material pigment or dyestuff
- synthetic resin selected from petroleum resin and oil modified synthetic resin in an organic solvent having an electrical resistance of no less than lO Qcm
- the coloring material (dyestuff or pigment) which is used in the liquid developer of the present invention includes not only carbon black, but also those of various hues, for example, Phthalocyanine Blue, Chrome Yellow, Aniline Black, red iron oxide Oil Black, Oil Red and Malachite Green because the developer has various uses other than copying.
- dyestuffs those which are insoluble in a dispersion medium, that is, the organic solvent, are preferable.
- the particle diameter of the colorant used in the liquid developer is preferably no more than 10 p. because microscopic particles produce a lithographic plate having a higher resolving power.
- the asphalt which is contained in the liquid developer usually comprises asphaltene, maltene and oily ingredients.
- the synthetic resin which is used in the liquid developer should be at least partially soluble in the organic solvent mentioned later.
- Useful synthetic resin of this class includes resin and petroleum resin, oilrnodified synthetic resin.
- the organic solvents which are used in the liquid developer are those having an electrical resistance of no less than IO Qcm, for example, solvent naphtha, mineral turpentine, turpentine oil, kerosine, n-heptane, carbon tetrachloride, etc.
- an organic solvent containing aromatic hydrocarbon having high dissolving power for example, solvent naphtha, mineral turpentine or turpentine oil.
- the content of the coloring material may vary withina range from 5 to percent by weight based on the total solid content in the liquid developer depending upon the particular coloring material and its physical and chemical properties the remaining solid material, i.e. asphat and resin, are than present in an amount of 95 to 25 percent by weight.
- the content of asphalt also depends upon the particular asphalt and its characteristics and may vary within a range from 1 to percent by weight based on the total solid content other than pigment.
- the content of asphalt has relevance to the receptivity of ink and, in view of the characteristics required as line images on lithographic plate, it is preferable to employ from 1 to 10 percent by weight of asphalt based on the total solid content.
- the content of the synthetic resin may also vary within a range from 10 to 99 percent by weight based on the total solid content other than pigment depending upon its ratio to the content of asphalt.
- the coloring material particles function 'as imageforming elementsin the developer.
- the developer can be made in any color; the coloring material may include those of various hues besides carbon black.
- content of both asphalt and synthetic resin should be determined in dependence of the particular coloring material because coloring materials usually have quite different physical and chemical properties from each other. For example, in the case of the coloring material having a higher oil absorption, the content of both asphalt and synthetic resin may be increased. On the other hand, if the coloring material has little oil absorption, the content of the asphalt and synthetic resin should be decreased.
- Asphalt is in a massive state composed of associated micelles. It comprises asphaltene, maltene and oily materials. It is easily soluble in organic solvent mainly containing aromatic hydrocarbon having a high dissolving power, i.e., solvent naphtha, mineral spirit, terpentine oil and the like. Some organic solvents having a high electrical resistance which are usually available as diluent, have a lower dissolving power and therefore, they do not completely dissolve asphalt. However, even in that case, asphalt forms fine colloidal particles having a high polarity and consequently, exhibits high adsorption together with asphalt micelles dissolved in the organic solvent. Consequently, the asphalt is adsorbed on the coloring material particles so that charged colloidal particles composed of coloring material and asphalt are formed. The colloidal particles carry positive charges and thusly are repelled by each other by like charges to produce stable image-forming particles.
- Synthetic resin is dissolved in the organic solvent to form a stable organosol and the organosol is adsorbed as a protective colloid with respect to the above-mentioned colloidal particle comprising coloring material and asphalt to form stable colloidal particles comprising coloring material, asphalt and the synthetic resin.
- the synthetic resin used in the present invention includes the exertion of a protective colloidal action on the coloring material-asphalt colloidal particles and the achievement of a satisfactory fixation of developed images
- the synthetic resin need not function as a polarity-controller.
- the synthetic resin used in the present invention may be chosen from those which are at least partially soluble and stably dispersible in organic solvent having an electrical resistance of no less than IO Qcm and which do not reduce the electrical resistance of the organic solvent to that which is less than lo flcm.
- toner particles containing the synthetic resin should be easily solidified by evaporation of organic solvent from the toner particles constituting just developed images or should be spontaneously solidified through oxidative polymerization of the synthetic resin contained in the toner particles.
- One of the most noticeable aspects of the present invention is that absence of any one component of the above-mentioned coloring material-asphalt-synthetic resin never answers the purpose of the present invention, that is, satisfactory line images on lithographic plate cannot be obtained.
- the developing solution containing only coloring materialasphalt colloidal particles and not containing the synthetic resin is employed, line images so formed are easily destroyed by the roller pressure applied in printing, not to mention mechanical action exerted in development and consequently, they stain the background because physical adsorptive power (fixation) of the toner particles and frictional resistance are extremely low.
- the developer of the present invention containing the above three components obviates the above defects and accordingly, it exhibits excellent stability, good fixation and high resolving power. lt also exhibits superior reproducibility of all kinds of images such as solid, half tone or thin line and produces good receptiveness of printing ink.
- EXAMPLE 1 obtain a developing solution. Using the developing solution, an image was formed on a master paper on which an electrophotosensitive layer was coated. The resultant lithographic plate was set up on an offset printing machine after the image-undeveloped area of the printing plate surface was desensitized to oil. 1,000 sheets of printing matter were printed by the offset machine. Various kinds of printed images, such as photography, large solid area or thin line were extremely clear.
- n-heptane 30 parts was mixed and dispersed for 20 hours in a ball mill and then, the resultant dispersion was charged into 30 l of n-heptane with stirring to obtain a developing solution.
- a developing solution Using the developing solution, a lithographic plate was prepared and 5,000 sheets of printing matter were printed in the same manner as described in Example 1.
- Various kinds of printed images, such as photography, large solid area or thin line exhibited good tone reproduction and excellent clearness.
- An electrophotographic liquid developer for the preparation of lithographic plates which comprises a uniform dispersion of at least one coloring material in particle form having an average particle diameter of no more than 10 microns selected from pigment and dyestuff capable of carrying a positive charge, asphalt and an oil modified alkyd resin, in an organic solvent having an electrical resistance of no less than 10 0 cm., said resin being at least partially soluble and not reducing the electrical resistance of said solvent to less than 10 0.
- said dispersion containing 5 to percent by weight of said coloring material based on the total weight of solid material and in the remaining solid material of said dispersion, said oil-modified alkyd resin being present in an amount of 10 'to 99 percent by weight and said asphalt in an amount of l to percent by weight based on the amount of said asphalt and resin in said dispersion.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Liquid Developers In Electrophotography (AREA)
Abstract
An electrophotographic liquid developer is provided which comprises a dispersion of at least one coloring material in particle form, asphalt and synthetic resin in an organic solvent having an electrical resistance of no less than 108 Omega . The liquid developer is useful for the preparation of lithographic plates.
Description
0 Waite States Patent 1 [111 3,714,048
Adachi et al. 1 Jan. 30, 1973 1 ELECTROPHOTOGRAPHIC LIQUID Refe ences Cited l g gag UNITED STATES PATENTS AND 0 3,554,946 1/1971 Okuno et al ..252/62.1 [75] Inventors: Syozo Adachi; Masasi Ueyama, both 3,523,900 8/1970 Ueda et al. ..252/62.1
of Tokyo, Ja an 3,438,904 4/1969 Wagner ..252/62.l 3,234,017 2/1966 Heyl et al. ..l17/l7.5 [73] Assignee: Iwatsu Electric Company Limited, 3,576,744 4/1971 Sharrock et al. ..252/62.l Tokyo, Ja an 3,198,649 8/1965 Metcalfe et a1 ..252/62.1 3,058,914 10/1962 Metcalfe et al ..252/62.1 [22] Filed: Sept. 28, 1970 [21] Appl. No.: 76,307 Primary Examiner--George F. Lesme's Assistant Examiner.l. P. Brammer Att0rneyRobert E. Burns and Emmanuel J. Lobato [30] Foreign Application Priority Data [57] ABSTRACT Oct. 23,1969 Japan "44/8 1910 An l ph g p developer is p d which comprises a dispersion of at least one coloring [52] U.S. Cl ..252/62.1 material] i parade f asphalt Synthetic resin in [51] Int. Cl. ..G03g 9/04 an rganic olvent having an electrical resistance of no [58] less than 10 0.. The liquid developer is useful for the Field of Search ..252/62.1
preparation of lithographic plates.
4 Claims, N0 Drawings ELECTROPHOTOGRAPHIC LIQUID DEVELOPER CONTAINING ASPHALT AND MODIFIED ALKYL RESIN This invention relates to an electrophotgraphic liquid developer, particularly available for the preparation of lithographic plates.
Heretofore, a liquid developers in electrophotography has only been contrived for mainly applying them to electrostatic copies and accordingly, has never been employed in the preparation of so-called lithographic plate" by which a large number of printed matter whereon highly images are printed, is produced. Because, in the case when conventional liquid developer is employed in the process of preparing the lithographic plate, the following defects are produced; first, a deposited amount of toner constituting images on an electrophotosensitive paper is less and in many cases, due to so-called fringing field effect" peculiar to a dry-type electrophotographic process, the serious loss of image density in the central part of half-tone images or of the solid area whereon toner should be wholly deposited is caused. Secondly, the weak adhesive power of toner particles to the lithographic plates results in poor receptivity of printing ink and in diminution of images onprinting because the printed images cannot withstand the roller pressure produced at the time printing.
Generally, in order to obtain good images on a lithographic plate, toner particles should have characteristics which satisfy the following prerequisites;
1. Toner particles should carry a stable positive charge.
2. They should have a microscopic fineness and electrical characteristics exhibiting high resolving power.
3. They should be superior in fixation property so that diminution of the printed images may be prevented. I
4. They should exhibit good receptivity of printing ink.
5. They should have good abrasion resistance.
6. They should cause less fog formation on the unexposed area.
7. The fringing field effect should appear least and accordingly, good tone reproduction of the photograph or of the solid area whereon toner particles should completely be deposited, is obtainable.
The object of the present invention is to obviate the above-mentioned defects present in the conventional lithographic processes and accordingly, to provide an electrophotographic liquid developer useful for the preparation of lithographic plates which have the characteristics satisfying the above-listed prerequisites.
According to the present invention, there is provided an electrophotographic liquid developer useful for the preparation of lithographic plates, comprising a uniform dispersion of at least one coloring material (pigment or dyestuff) in particle form asphalt and synthetic resin, selected from petroleum resin and oil modified synthetic resin in an organic solvent having an electrical resistance of no less than lO Qcm, said synthetic resin being at least partially soluble in the organic solvent.
The coloring material (dyestuff or pigment) which is used in the liquid developer of the present invention includes not only carbon black, but also those of various hues, for example, Phthalocyanine Blue, Chrome Yellow, Aniline Black, red iron oxide Oil Black, Oil Red and Malachite Green because the developer has various uses other than copying. As dyestuffs, those which are insoluble in a dispersion medium, that is, the organic solvent, are preferable. The particle diameter of the colorant used in the liquid developer is preferably no more than 10 p. because microscopic particles produce a lithographic plate having a higher resolving power.
The asphalt which is contained in the liquid developer usually comprises asphaltene, maltene and oily ingredients.
The synthetic resin which is used in the liquid developer should be at least partially soluble in the organic solvent mentioned later. Useful synthetic resin of this class includes resin and petroleum resin, oilrnodified synthetic resin.
The organic solvents which are used in the liquid developer are those having an electrical resistance of no less than IO Qcm, for example, solvent naphtha, mineral turpentine, turpentine oil, kerosine, n-heptane, carbon tetrachloride, etc. In case the composition of coloring material, asphalt and synthetic resin is previously mixed using a mixer such as a ball mill, it is preferable to employ an organic solvent containing aromatic hydrocarbon having high dissolving power, for example, solvent naphtha, mineral turpentine or turpentine oil.
The content of the coloring materialmay vary withina range from 5 to percent by weight based on the total solid content in the liquid developer depending upon the particular coloring material and its physical and chemical properties the remaining solid material, i.e. asphat and resin, are than present in an amount of 95 to 25 percent by weight.
The content of asphalt also depends upon the particular asphalt and its characteristics and may vary within a range from 1 to percent by weight based on the total solid content other than pigment. However, the content of asphalt has relevance to the receptivity of ink and, in view of the characteristics required as line images on lithographic plate, it is preferable to employ from 1 to 10 percent by weight of asphalt based on the total solid content. Further, the content of the synthetic resin may also vary within a range from 10 to 99 percent by weight based on the total solid content other than pigment depending upon its ratio to the content of asphalt.
The effects and functions exercised by the above three ingredients in the liquid developer will be described hereinafter.
The coloring material particles function 'as imageforming elementsin the developer. In view of the fact that the liquid developer of the present invention is available for uses other than the usual copying, the developer can be made in any color; the coloring material may include those of various hues besides carbon black. It is, however, noted that content of both asphalt and synthetic resin should be determined in dependence of the particular coloring material because coloring materials usually have quite different physical and chemical properties from each other. For example, in the case of the coloring material having a higher oil absorption, the content of both asphalt and synthetic resin may be increased. On the other hand, if the coloring material has little oil absorption, the content of the asphalt and synthetic resin should be decreased.
Asphalt is in a massive state composed of associated micelles. It comprises asphaltene, maltene and oily materials. It is easily soluble in organic solvent mainly containing aromatic hydrocarbon having a high dissolving power, i.e., solvent naphtha, mineral spirit, terpentine oil and the like. Some organic solvents having a high electrical resistance which are usually available as diluent, have a lower dissolving power and therefore, they do not completely dissolve asphalt. However, even in that case, asphalt forms fine colloidal particles having a high polarity and consequently, exhibits high adsorption together with asphalt micelles dissolved in the organic solvent. Consequently, the asphalt is adsorbed on the coloring material particles so that charged colloidal particles composed of coloring material and asphalt are formed. The colloidal particles carry positive charges and thusly are repelled by each other by like charges to produce stable image-forming particles.
Synthetic resin is dissolved in the organic solvent to form a stable organosol and the organosol is adsorbed as a protective colloid with respect to the above-mentioned colloidal particle comprising coloring material and asphalt to form stable colloidal particles comprising coloring material, asphalt and the synthetic resin.
Some coloring material and the synthetic resin have little wetting property or low oil absorption and therefore, the mixture of the coloring material and the synthetic resin has a tendency to give an unsatisfactory fixation of developed images. But in practice, as asphalt is extremely adsorbent on the coloring material, stable colloidal particles comprising coloring material, asphalt and the synthetic resin are also obtainable. Thusly formed colloidal particles carrying charges, go hand in hand with protective colloidal action by synthetic resin to prevent the developing agent from aggregating. In other words, because asphaltene micelles composing asphalt are extremely adsorbent and carry high positive charges, the colloidal particles of coloring material-asphalt-synthetic resin carry positive charges in the aggregate and consequently prevent aggregate-formation between particles.
In view of the fact that the purposes of the synthetic resin used in the present invention includes the exertion of a protective colloidal action on the coloring material-asphalt colloidal particles and the achievement of a satisfactory fixation of developed images, the synthetic resin need not function as a polarity-controller. Accordingly, the synthetic resin used in the present invention may be chosen from those which are at least partially soluble and stably dispersible in organic solvent having an electrical resistance of no less than IO Qcm and which do not reduce the electrical resistance of the organic solvent to that which is less than lo flcm. Further, it will be noted that toner particles containing the synthetic resin should be easily solidified by evaporation of organic solvent from the toner particles constituting just developed images or should be spontaneously solidified through oxidative polymerization of the synthetic resin contained in the toner particles.
One of the most noticeable aspects of the present invention is that absence of any one component of the above-mentioned coloring material-asphalt-synthetic resin never answers the purpose of the present invention, that is, satisfactory line images on lithographic plate cannot be obtained. For example, in case the developing solution containing only coloring materialasphalt colloidal particles and not containing the synthetic resin is employed, line images so formed are easily destroyed by the roller pressure applied in printing, not to mention mechanical action exerted in development and consequently, they stain the background because physical adsorptive power (fixation) of the toner particles and frictional resistance are extremely low. On the other hand, in the case of a developing solution containing only coloring materialsynthetic resin particles, good images cannot be obtained or, even if better formation of the highly resolved images is expected, as the adsorptive power of the synthetic resin in the coloring material is inferior to asphalt, line images thusly formed are lacking in receptivity of printing ink. Furthermore, in the case of a developing solution containing only asphalt-synthetic resin colloidal particles, as no image-forming elements exist the deposited amount of toner on a charged area, on which line images are to be formed, is reduced. Therefore, the above three developers are not suitable for a printing plate.
On the contrary, the developer of the present invention containing the above three components, obviates the above defects and accordingly, it exhibits excellent stability, good fixation and high resolving power. lt also exhibits superior reproducibility of all kinds of images such as solid, half tone or thin line and produces good receptiveness of printing ink.
The following examples will serve to illustrate the present invention, in which all parts are by weight.
EXAMPLE 1 obtain a developing solution. Using the developing solution, an image was formed on a master paper on which an electrophotosensitive layer was coated. The resultant lithographic plate was set up on an offset printing machine after the image-undeveloped area of the printing plate surface was desensitized to oil. 1,000 sheets of printing matter were printed by the offset machine. Various kinds of printed images, such as photography, large solid area or thin line were extremely clear.
EXAMPLE 2 The following composition, which contained 15 parts of Phthalocyanine Blue,
10 parts of Oil Black,
5 parts of blown asphalt having a hardness scale (penetration of the indentor) of 30 40,
40 parts of vinyltoluene oil containing 40 percent of vinyltoluene; and
30 parts of n-heptane was mixed and dispersed for 20 hours in a ball mill and then, the resultant dispersion was charged into 30 l of n-heptane with stirring to obtain a developing solution. Using the developing solution, a lithographic plate was prepared and 5,000 sheets of printing matter were printed in the same manner as described in Example 1. Various kinds of printed images, such as photography, large solid area or thin line exhibited good tone reproduction and excellent clearness.
EXAMPLE 3 A following composition, which contained 20 parts of Malachite Green,
parts of straight asphalt having a hardness scale (penetration of the indentor) of 100 120,
40 parts of terpene resin; and
'30 parts of carbon tetrachloride was mixed and dispersed in a ball mill for hours and then, the resultant dispersion was diluted with l of kerosine to obtain a developing solution. Using the developing solution, lithographic plates were prepared and 3,000 sheets or printing matter were printed as described in the above Examples. The printed images were clear as described above.
' What we claim is:
1. An electrophotographic liquid developer for the preparation of lithographic plates which comprises a uniform dispersion of at least one coloring material in particle form having an average particle diameter of no more than 10 microns selected from pigment and dyestuff capable of carrying a positive charge, asphalt and an oil modified alkyd resin, in an organic solvent having an electrical resistance of no less than 10 0 cm., said resin being at least partially soluble and not reducing the electrical resistance of said solvent to less than 10 0. cm., said dispersion containing 5 to percent by weight of said coloring material based on the total weight of solid material and in the remaining solid material of said dispersion, said oil-modified alkyd resin being present in an amount of 10 'to 99 percent by weight and said asphalt in an amount of l to percent by weight based on the amount of said asphalt and resin in said dispersion.
2 An electrophotographic liquid developer according to claim 1 wherein said coloring material is insoluble in said organic solvent.
3. An electrophotographic liquid developer according to claim 1 in which said organic solvent contains aromatic hydrocarbon.
4. An electrophotographic liquid developer according to claim 1 in which said oil-modified alkyd resin is a soybean oil-alkyd resin.
Claims (3)
1. An electrophotographic liquid developer for the preparation of lithographic plates which comprises a uniform dispersion of at least one coloring material in particle form having an average particle diameter of no more than 10 microns selected from pigment and dyestuff capable of carrying a positive charge, asphalt and an oil modified alkyd resin, in an organic solvent having an electrical resistance of no less than 108 Omega cm., said resin being at least partially soluble and not reducing the electrical resistance of said solvent to less than 108 Omega cm., said dispersion containing 5 to 75 percent by weight of said coloring material based on the total weight of solid material and in the remaining solid material of said dispersion, said oil-modified alkyd resin being present in an amount of 10 to 99 percent by weight and said asphalt in an amount of 1 to 90 percent by weight based on the amount of said asphalt and resin in said dispersion.
2. An electrophotographic liquid developer according to claim 1 wherein said coloring material is insoluble in said organic solvent.
3. An electrophotographic liquid developer according to claim 1 in which said organic solvent contains aromatic hydrocarbon.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8491069 | 1969-10-23 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3714048A true US3714048A (en) | 1973-01-30 |
Family
ID=13843870
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00076307A Expired - Lifetime US3714048A (en) | 1969-10-23 | 1970-09-28 | Electrophotographic liquid developer containing asphalt and modified alkyl resin |
Country Status (3)
Country | Link |
---|---|
US (1) | US3714048A (en) |
DE (1) | DE2052201A1 (en) |
GB (1) | GB1313350A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3968044A (en) * | 1974-02-01 | 1976-07-06 | Rank Xerox Ltd. | Milled liquid developer |
US4058470A (en) * | 1975-10-24 | 1977-11-15 | A. B. Dick Company | Liquid developer composition for lithographic masters |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3058914A (en) * | 1957-10-01 | 1962-10-16 | Commw Of Australia | Non-inflammable liquid developers for electrostatic images |
US3198649A (en) * | 1959-05-13 | 1965-08-03 | Commw Of Australia | Controlled and fixing liquid developer for electro-photography and electroradiography |
US3234017A (en) * | 1959-11-05 | 1966-02-08 | Agfa Ag | Process for the production of developed electrophotographic images including application of a breakdown potential to discrete small areas of a photoconductor |
US3438904A (en) * | 1966-01-10 | 1969-04-15 | Scm Corp | Liquid toner |
US3523900A (en) * | 1967-03-18 | 1970-08-11 | Yasuo Ueda | Liquid developers for developing electrostatic images |
US3554946A (en) * | 1966-11-21 | 1971-01-12 | Ricoh Kk | Liquid developers for electrophotography containing a pigment coated with a copolymer |
US3576744A (en) * | 1967-09-21 | 1971-04-27 | Clopay Corp | Electrostatic developing composition containing two different negative directing resins |
-
1970
- 1970-09-28 US US00076307A patent/US3714048A/en not_active Expired - Lifetime
- 1970-09-29 GB GB4621470A patent/GB1313350A/en not_active Expired
- 1970-10-23 DE DE19702052201 patent/DE2052201A1/en active Pending
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3058914A (en) * | 1957-10-01 | 1962-10-16 | Commw Of Australia | Non-inflammable liquid developers for electrostatic images |
US3198649A (en) * | 1959-05-13 | 1965-08-03 | Commw Of Australia | Controlled and fixing liquid developer for electro-photography and electroradiography |
US3234017A (en) * | 1959-11-05 | 1966-02-08 | Agfa Ag | Process for the production of developed electrophotographic images including application of a breakdown potential to discrete small areas of a photoconductor |
US3438904A (en) * | 1966-01-10 | 1969-04-15 | Scm Corp | Liquid toner |
US3554946A (en) * | 1966-11-21 | 1971-01-12 | Ricoh Kk | Liquid developers for electrophotography containing a pigment coated with a copolymer |
US3523900A (en) * | 1967-03-18 | 1970-08-11 | Yasuo Ueda | Liquid developers for developing electrostatic images |
US3576744A (en) * | 1967-09-21 | 1971-04-27 | Clopay Corp | Electrostatic developing composition containing two different negative directing resins |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3968044A (en) * | 1974-02-01 | 1976-07-06 | Rank Xerox Ltd. | Milled liquid developer |
US4058470A (en) * | 1975-10-24 | 1977-11-15 | A. B. Dick Company | Liquid developer composition for lithographic masters |
Also Published As
Publication number | Publication date |
---|---|
DE2052201A1 (en) | 1971-05-27 |
GB1313350A (en) | 1973-04-11 |
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