CA1087014A - Liquid developer for color electrophotography and process for preparation of the same - Google Patents
Liquid developer for color electrophotography and process for preparation of the sameInfo
- Publication number
- CA1087014A CA1087014A CA255,613A CA255613A CA1087014A CA 1087014 A CA1087014 A CA 1087014A CA 255613 A CA255613 A CA 255613A CA 1087014 A CA1087014 A CA 1087014A
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- CA
- Canada
- Prior art keywords
- weight
- liquid developer
- liquid
- organic
- developer
- 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.)
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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
- G03G9/135—Developers with toner particles in liquid developer mixtures characterised by stabiliser or charge-controlling agents
-
- 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
Abstract
LIQUID DEVELOPER FOR COLOR ELECTROPHOTOGRAPHY
AND PROCESS FOR PREPARATION OF THE SAME
ABSTRACT:
Liquid developer formulations adapted to colored toners suitable for trichromatic processes in electrophotography, the toners being lightfast organic dye pigments with substantially no photoconductivity which are mixed with a paraffinic material as a protective polymer (a dispersing liquid being used if the protec-tive polymer is a solid) and suspended in an insulating hydro-carbon carrier medium together with a metal soap and a phenol derivative soluble in the carrier.
AND PROCESS FOR PREPARATION OF THE SAME
ABSTRACT:
Liquid developer formulations adapted to colored toners suitable for trichromatic processes in electrophotography, the toners being lightfast organic dye pigments with substantially no photoconductivity which are mixed with a paraffinic material as a protective polymer (a dispersing liquid being used if the protec-tive polymer is a solid) and suspended in an insulating hydro-carbon carrier medium together with a metal soap and a phenol derivative soluble in the carrier.
Description
BACKGROUND OF THE INVENTION:
1.) Field of the Invention 'rhe present invention refers to a liquid dev~loper for color electrop~oto~raphy and to ~ process for its prepara~ion.
1.) Field of the Invention 'rhe present invention refers to a liquid dev~loper for color electrop~oto~raphy and to ~ process for its prepara~ion.
2.) Description of the Prior Art Production of colored or multi-colored ima~es by eLeccropho~o~raphic processes can be acromplished, for cx~mp~e, ~s ~isclo~d in U.S. Patent 3901696, of ~rhich we arc the inv~nto~s and which is assigned to the same assignee. Accordin3 to this patent, an im~e is obtained by exposin~ a photoco~ductin~, layer Lo an original, thus producing on ~r in this layer a co~ducti~ity ~ ern corresponding to the ori~inal. The patt~rn is ~1sed ~o ccn~-ro?. a fieLd p.od~1-ed by means of two elecr.rode~" tho field I being in the space between the photoconduc~in~ l~yer and a support ~or the image to be produced, Electri.ea~ly-ch~r~ed ~oner ?~rtic~e~
in th~ ~bove-mentir~ne~ space .~re move~ th~ou~3~ this field. the toner p~1rticles h~vln~, their orizill in ~ ui~ deve1~ r int~o- 1 30 duced into the space be~ween the phot~,conr.!uctin~ er ~nd the ~ 1 3 ' ....... , ';:: ' ' ~'' :,:.: ' ' ;:' . '. " `:' .'`.
. . ' ~ : :;:. : ' : - ~ ' : " ' , . ' ';', , . . :~: :: : ' "' ~oæ~0l4 1 imn~,e s-lpport prior to es~ablifihln~, t~ fi~ld. Thc pol~rity of the toner particles and the polarity of the electrode assl~,ned to the pho~oconductirl~ layer are ei~her selected ~ppos~te to one another so that the toner particles deposlt on the photoconductin~
layer, or these pol~rit~es are selec~ed to be identical so that the toner particle~ deposit on the support. The electrical field ~s ~ubsequently interrupted, RS a result of wh~ch in the first case toner particle~ migrate from ehe photoconducting layer to the support and produce on the la~ter a positive irna~e cor~espondin~
to the original whereas in the second case, toner particles migrate from the support to the photoconducting layer and thus leave behind on the support a ne~ative ima~e corresponding to the orl~inal.
The present invention thus concerns a ~.iquid d~veloper for color electrophotography, particularly the proces~ (hereinafter referred to as the "conductlvity modulation process") of the above-cited U.S. patent, and while it is possible, of course, to produce color images eLectrophoto~raphically according to the mentioned process using already known developers, the images produced in that manner still le~ve much ~o be desired with respect to contrast, sharpness, resolution and color saturation.
Furthermore, in the production of multicolored ima~es by s~lper-positlon of severnl partial color ima~es, certain difficul.ties hav been encountered, for example, when conventional "self-fixing"
agents in known developers deposit together with color pigmen~s of a partial ima~e ~nd modify the surface of the support bearing the partial ima~e. The modification occurs in such manner that it significantly disturbs the subsequent step for formation of a nexS partial color lmage, with resultant inability to produce high quality copies of the original.
7~14 01 The above~mentioned difficulty cannot be eliminated 02 simply by omission of the fixer in the developer since other 03 essential properties of the developer are then impaired 04 unacceptably. Another requirement with respect to the dye 05 pigments of such developers lies in the fact that the images 06 produced therewith must be permanent, and light- and solvent ;07 resistant. Further, in known developers the color pigments are 08 customarily embedded in a resin shell. Such a dye pigment resin 09 mass must be pulverized to a fineness not possible by mechanical means as regards the pigments used in the developer disclosed 11 here.
12 Since no optimal developer is yet known for the 13 above-mentioned process for electrophotographic image production, ~14 the basic task of the present invention is to create a liquid developer for production of colored or multicolored images by ~16 means of electrophotography; a developer which does not exhibit 17 the named disadvantages and is particularly characterized by the 18 fact that it results in high contrast, sharp color images 19 exhibiting a high image resolution and a high color saturation, one which ensures the unobjectionable superposition of individual 21 partial color images in the production of multicolored copies.
22 The task also comprises creation of a process for production of 23 the named liquid developer.
~24 SUMMARY OF THE INVENTION:
The present invention concerns a liquid developer for 26 color electrophotography comprising an organic highly insulating 27 liquid of low polarity as dispersion medium for from about 0.1 to 2~ about 5% by weight of at least one lightfast, organic dye pigment 29 of low density and from about 0.1 to about 10% by weight of polyisobutylene having a molecular weight of greater than 1,000 31 and less than 1,000,000 as a protective polymer, at least one C, ' 01 metal soap containing a multivalent cation and a fatty acid 02 radical with 8 to 14 carbon atoms contained therein in from about 03 10-4 to about 1o-l molar quantity for c~arge control of the 04 dispersion, and Erom about 0.001 to about 1% by weight of at 05 least one hydrocarbon-soluble phenol derivative as an oxidation 06 protective agent for age stabilizing the liquid developer~
07 The invention also concerns a process for preparation 08 of a liquid developer comprising the steps of: o 09 (1 ) producing a viscous mixture of at least one lightfast, organic dye pigment of low density and polyisobutylene ~11 having a molecular weight of greater than 1,000 and less than ~12 1,000,000 as protective polymer by ~13 (2.) grinding said mixture a plurality of times in a 14 multi-roll millr (3.) a. diluting the viscous mixture obtained in step ~16 2, with an organic highly insulating liquid of low polarity while 17 agitating, and 18 b. adding in the course of the dilution at least 19 one metal soap containing a multivalent cation and a fatty acid radical with 8 to 14 carbon atoms as a charge control agent and 21 at least one hydro-carbon-soluble phenol derivative selected from 22 the group consisting oE 2,6-ditertiary butyl-4-methyl-phenol and 23 1,3,5-trimethyl-2,4,6-tris-(3,5-tertiary butyl-4-hydroxybenzyl) 24 -henzene as an oxidation protective agent for age stabiliæing the liquid developer, 26 (4.) ceasing the dilution when the dye piyment content 27 makes up 10% by weight of the solution, thereby forming a liquid ~28 concentrate storable at the specified pigment content, and 29 (5.) diluting the storable concentrate further with an organic highly insulating liquid of low polarity in a final 31 process step to obtain a concentration of dye pigment of from 32 - 3a -~J
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loE~r~
01 about 0.1 to 5% by weight, of polyisobutylene as protective 02 polymer of from about 0.1 to about 15% by weight, of said at 03 least one hydrocarbon-soluble phenol derivative as an oxidation 04 protective agent oE from about 0.001 to about 1% by weight, and 05 the metal soap as charge control agent in from about 10-4 to 06 about 10-1 molar quantity, so as to make the developer ready for ~:
07 use.
09 In the following description, the invention is illustrated in more detail.
11 Liquid developers according to the present invention 12 are characterized in the ready-to-use state by the following 13 data:
;16 18 :
`19 .
~(~l37~4 01 viscosity of 1-10 cP (centipoises), 02 speci~ic resistance of 109 and 1012 ohm cm, 03 specific charge of 200~2000,~C/g (microcoulomb/gram), 04 and 05 pigment particle size of 0.1-5,~m (microns).
06 Since a liquid developer of the named typed should be ;
07 ready to use for an extended time, e.g. four weeks, it is 08 important that changes in its properties, such as irreversible -~
09 agglomeration of the dye particles, should not occur within this time span. Also, with respect to image resolution and desired 11 color saturation, it is important to select an advantageous size 12 distribution of the particles used as dye pigment. For the 13 color developer according to the invention, only those 14 substances are suitable which, after a partial color image has been deposited, have not modified the image support surface such 16 that further production of partial images is made difficult or 17 impossible. The liquid developer according to the invention 18 further ensures complete depositing of the dye pigment material 19 present during the particular image formation step at the illuminated points, the charge remaining behind on the deposited 21 partial color images being so trivial in each case that ;22 transport of already-precipitated pigment particles .
':
- 4a -~'~
1 10;37014 1 ~ by electrlc~l f~elds is no lon~er po~sible in fiubsequent lmnr,e production steps.
¦ Althou~h the liquid developer accordin~ to the invention l contain6 none of the fixer customary in known developers, the .
5 ¦ partial color images produced with the developer accordin~ to the ¦invention have proven to be sufficiently sturdy to wi~hstand ¦successive operatio~s in the ima~e production process such as ¦squeezin~ out superfluous disper~ion, rec~iving a further p~rtial ¦color image, Laminating a protectlve layer on the finished copy 10 ¦etc., without undergo~ng damage.
A liquid developer accordlng ~o the present invention ¦consists of the followin~ componentst ¦1.) Disper~ion mediums Org~nic, highly insulatin~ liquid of low 1 polarity with the following propertiess 15 ¦ specific resistance at least 1012 ohm cm dielectric constant (maximum) 4 boiling point between 130 and 1~0 C.
¦ As particular examples of materials that are effeceive, one l can list: ISOPAR E, G, and H (thes~ bein~ trademarks fo~ long 20 ¦ chain saturated hydrocarbons differing in vapor pressure, boiling point and viscosity which are commercially av~ilable from Esso), S~LLSOL (trademark for a similAr hydrocarbon supplied by Shell), kerosene, polysiLoxanes, and fluorohydrocarbons.
2,) Organic dye pigments Ligh~fast materials of low density which correspond as exactly as possible to one of the ideal subtractive basic colors (yellow, purple, blue-green) for the production of color ima~es.
particle diameter 0,1-5 ~m (microns) (5 O~L43 I den~ty (m~xlm~m 2 ~ cm Pi~r,ment materinls m~y have no pronounced photoconductlve propertles. Here, exemplary materl~Ls for utllizatlon include the followin~l Ycllow~ Dinzo dye~, prefer~bly of the bcnzidine fier~.es. .
OP~ASIN yellow 141, ~t (BASF, I.l.ldwi~sh~fen, West Ge?I~any.
~ELIO f~st yellow GRN, TM (Bayer, Leverkufien, West Germnny) (Color Index Il Pl~men~ Yellow 13lColor Index II
l0 ¦ No. 21,l00) ¦ Also usefuL, but with results somewhat inferior to the ¦ above, were the following yellow materials:
. ¦ LITHOL f~st yellow 1780, TM (BASF, Ludwigshafen, West Germany) (Color Index I: Pi~ment Yellow 83/Color Index II: - ) . ¦ ~IANS~ yellow (, 01, ~1 (~lO~CllST, ~r~nkf~lrt a/m West Germany) : ¦ (Color Index I: Pigment Yt.?llOW l/Color Index II: llfi80) GRAPIIT()L yellow GRBL, TM (S~NDOZ, Basel, ~witzerland) (Color Index I: Pi~ment Yellow 13/Color Index Ilt 2L100) Purple~ Dye l~cquers of ac~dic or b~sic xanthene dyeR, FANALR~S~ ~M 4830, I~ ASF, Ludwigshafen, We~t Germany) ; (C~lor Index 1I Pi~men~ Red 81/Color Index llt No. 45,160).
.. .,_. , Also usef~ll, b~l.t with res~lLt~ somewha~ inferior to the al~ove, were tht.~ foll.owin,lr pnrpl~? matt?ri.al~:
PIIR~ IIORNA permunent pinlc AE~lW-~5, ~1 (TI~N IIORN, ~aastricht N~therlands) (Color Index I: Pi~ment Red 81/Color Index II:
~ HEL10 fast pink E, l~ (B~YER, Leverkusen. West Germany) : (Color Intlex I: Pi~ment Red 122/Color Index II: - ) !
SANDORIN bri~liant red SBL, ~l (SANDOZ, Basel, Switzerlani) (Color Index l: Pigmen~ Red 192/Color Index Il: - ) ¦
FA~TEL red B, lM (ICI, Manche~ter, En~land) (Color Index I: Pigment Red ,81/CoLor Index II: 45160 .. , - ... ... .. ~ I
.~.
~' ' - 6 ~
~0~7~14 ~ c-r~reent ~lodlfied Ph~halocynnin~s w~lic11 are r,onphotoconduc~in~, or onl~ htly photoconductln~.
~EL10 fast blue G0, TM (~ayer, Leverku~en, West Germany) (CoLor Index I~ Pi~ment Blue 15/Color Index II~
11 No. 74,160).
Al.so usefu~, but with resuLts somewh;~t: inferior to the above, were the folLowing blue-green materials:
~';AN~O~IN blu~ 2 CLS, ~1 (SA~DO~,, Basel, Switzerland) (Color Index I: Pigment Blue l5¦Color Inclex II: 7~ 0) O~PASI~ bLue 6~7, ~ (BASF, Ludwigshafen, West ~ermany) (Co~or Index I: Pigment Blue 60/Color Index II: 69800) IR~AZ.IN btue 3 GT, ~l (CIBA-GEIGY, Basel, Switzerlan~) (~o1Or Index I: Pi~,ment Blue 16/Color In~ex Il: 741~) 13.~ C'har~,e control a~entl Metal soaps with a multivalent ca~ion ¦ and fatty acid radicals with 8 to 14 c~rbon a~.oms.
¦ Dissocia~ion constan~ IC of approximately 10 . ~s materi.aLs ¦ which have proven sultable, one can mention metal soaps such as Co^decanoate, Zr-decanoate, and Ca-decanoate (all three ¦ bein~ available commercially from SC~D0 of 7.wolle, 20 ¦ Ne~herlan~s).
Protective polymerl ~ ,h molecular wei~h~ waxy aliphatlc hydrocarbons (hereinafter referreA t.~ ~enerally as "paraffins' pa~tlcu1,arly of tho branched typn, wi~h 10~-~ M c 106 (~l bclng , the molecular weight). The protectlYe polymer serves for ¦ ndJu~tment of optlmnl vi~co~qity Ln t~le mcchnnicll~ pu1v~rl-zntion (~levatlon of the 3hear force~ ~nd thus the millln~
. ¦ efflciency) ns well as for increasin,~ stnbllity of the ¦ flnished llquid developer. The parAffin is f~ y soluble ¦ ln the dlsporsion medlum, docs not form n coatln~ on the partlcles, and has no essential fixin~ action. Furthennore, . ¦ it cnuses lit~le, if any, lnterference with the action of the ,, ¦ above-mentioned charge control agent. Thou~h other paraff ill6 l have been used su~cessfully here, a materi~l proven __ ___ ~
~ 7a~4 l pnrcic~Ilnrly sultnble ifi polyisobutylenc, 8 br~nched type ¦ paraff~n avallable comm~rcinlly under the trademark OPP~NOL .
B3 from ~ASF, Ludw~shAfen, West Germ~ny.
()ther paraffins useful as protective polymer, but with results ¦
some~h<lt inferior ~o the above were OPP~NO~ B 50, T~I (B~SF, Ludwigshafen, West Germ~ny) POLYOEL ~IUELS llO, TM (IIUE~S A~" ~Iarl, West Cermany), a p~lybutadiene IN~OPOL ~I 25, ~l (~/OCO Chemicals Europe, Geneva, SwitzerLand), t~ polybutylene HYVIS 5, ~l (BP Chemicals In~Il. Ltd., London, En~land), a poIybntylene 5.) Oxid~tion protective agent: .
~aterinlF. such 8fi hydrocarbon-soluble phenol deriva-Lives, whlch h3nder ~ rapid a~ing of the l1quid developer by oxidative processes, partlcularly at hlgher temperatures.
~xamples of the be3t such phenol derlvatlves are 2,6-di-terti~ry butyl-4-methylphenoL (~vailable commercially from Shell under the trademark IONOL CP) and 1,3,5-trimeehyl-2,4,6-tris-(3,5-di-tertiary bu~yl-~-hydroxybenzyl)-benzene (available commercially from Shell under ~lle trademark IONOX 330)- t Al so ~Isef-l- as Oxidation protective a~,en~, but with results somj what inferior to the above were IR~ROL IIV2 ~I (Cl~-G~I~Y, ~Iarienberg, West (,ermany) ~'.CINlN P, T~ (B~YER, I.everk-I~en, West Cermany~
Thé liquid developer is preferably prep~red as follows~ A
Vt 5COUS mixture of dye pi~ment and protective polymer ls prepared ¦by ~r3.nding the in~redients nt least twice in a three-rolL mill to ¦obta~n the desired size ran~e of the pi~ment partic~Les. Conven-iently, a disperfiion medium mny also be added in c~se the protectlve polymer 13 a solid. The mssq obt~lned ln this m~nner lfi then dllu~ed with difipersion medium while addlng charge control .....
; - 8 -. ~
~0~014 I agen~and oxidntlon protectlvc ~ent up to the point wllerc t~e dy~
p~gment content amounts to lO percent by welght. ~or attainment of ~ood, complete mixin~, thiG dilution may conveniently be accomplished with continuous agitation in a high frequency disperser. In th~s re~uLtant concenerated form, the liquid developer can be stored over an extended time w~thout d~teriora~io .
For preparstion of the liquld developer ready for use, a certain amount of the concentrate i~ diluted further to a desired pSgment concen~ration~ descri~ed subsequently, again under constant stirrlng.
A de~ailed formula now follows for a liquid deveLoper having the color yellow, one for the color purple, and lastly one for rhe color blue-~reent 1S Example 1 -- Yellow Liquld developer 250 ~. yellow pi~ment (Helio fast yellow GRN, Bayer) i.~
ground together two times with 750 g. OPP~NOL B3 tB.~ F) on a ~hree-roll mill to produce 1000 g. of a 25% paste. 100 ~. of . this 25,~, paste is agita~ed well with 25 ~. zirconium decano~at~
(Scado, 12~/o me~al content), 5 g. IONOL CP (Shell) diLuted to 250 g. wlth ISOPAR G (Esso), and a~itated for lO minutes with a hi~h frequency agitator. sn g~ of this 10% conc~ntrate i~
diluted with the ISOPAR G to 1000 g. and sh~ken well. In ~h~s manner, a "ready-to-use" liquid developer re~ults which contains 0.5'10 pi,gment, 1.5% OPPANOL B3 (BASF), 0.5% zirconlum decanoate (Scado) and 0.1% IONOL CP (Shell).
E mple 2 -- Purple L~quid developert All operations and weight s~atemen~ ~re the same as in the fore~oln~ flrst example with the exceptlonst instead of yellow pigment, a purple pl~ment (FANALROSA S~l 4830, BASF) is used and cobalt decanoate (Scado, 8% metaL content) is used instead of zirconium decanoate. The concentrations of the ingredi~nts of the finished purple liquid developer ready for use thus amount ~o 0.5% pi~men~, 1.5% OPPANOL B3 (BASF), 0.5% cobalt decanoate (Scado), and 0.1% IONOL CP (Shell).
10 I .
I Example 3 -- Blue-~reen Llquid developert I
¦ All operations and weight statements are the same as in the first example with the following exceptionsl blue-green (cya~
l pigment (~leLio fas~ blue GO, B~yer) i6 used ln~tead of y~low 15 ¦ pigment and 5 g. zirconium decanoate (Scado) i8 used in3tead ¦ of 25 g. zirconium decanoate.
The concentrations of the ingredients of the finished, "ready to-use" blue-æreen liquid developer thus amount to 0.5~/0 pigment, 1.5% OPPANOL B3 ~BASF), 0.1% Zirconium decanoate 20 ¦ (SCADO), and 0.1% IONOL CP (Shell).
¦ The above three liquid developers, when used in an ap~aratus ¦l~ccording to the previousLy-c$ted U.~. pa~ent, gave rise to the very best copies, these having high contrast, sharp color images with high resolu~ion and color saturation. Nearly equal results were obtained with the other materials listed when incorporated in Liquid developers of the type disclosed and used in the above-mentioned apparatus. Further, while the specific examples givcn recite particular concentrations, these are merely ~he values for th~ very best results with the materials of these examples~ ehere . I
~ 7~4 1 being a range of values in which the result~ are substantlal~y iden~ical. As ~o the remaini.ng rnateri~ls, in fiome cases the ral)~e . . depends on the p~rticul~r ones of the materl~1s which are combined.
Thus, it has been found experimentally with the materials disclosed 5 herein that copies of excellent quality can be obtained with finished liquld developers where concentration of the indivldua~
components range in amoun~ (wei~ht percent except as in~icated) --Pigment O.l to 5%, preferably Q.3 to 0.8%
¦ --Charge control a~ent 10 ~o 10 mol~r t preferably ld-3 - 10 2 molar --Pro~ective polymer 0.1 eo 10%
--Oxidaeion protec~ive agent 0.001 to 1%, preferably 0.1%.
While par~icular embodiments of the inven~ion have been shown 15 and described, modifications will be evident to those skilled in the art, and it is intended in the claims to covar all such modi~ications which fall within the spirit and scope of the invention.
in th~ ~bove-mentir~ne~ space .~re move~ th~ou~3~ this field. the toner p~1rticles h~vln~, their orizill in ~ ui~ deve1~ r int~o- 1 30 duced into the space be~ween the phot~,conr.!uctin~ er ~nd the ~ 1 3 ' ....... , ';:: ' ' ~'' :,:.: ' ' ;:' . '. " `:' .'`.
. . ' ~ : :;:. : ' : - ~ ' : " ' , . ' ';', , . . :~: :: : ' "' ~oæ~0l4 1 imn~,e s-lpport prior to es~ablifihln~, t~ fi~ld. Thc pol~rity of the toner particles and the polarity of the electrode assl~,ned to the pho~oconductirl~ layer are ei~her selected ~ppos~te to one another so that the toner particles deposlt on the photoconductin~
layer, or these pol~rit~es are selec~ed to be identical so that the toner particle~ deposit on the support. The electrical field ~s ~ubsequently interrupted, RS a result of wh~ch in the first case toner particle~ migrate from ehe photoconducting layer to the support and produce on the la~ter a positive irna~e cor~espondin~
to the original whereas in the second case, toner particles migrate from the support to the photoconducting layer and thus leave behind on the support a ne~ative ima~e corresponding to the orl~inal.
The present invention thus concerns a ~.iquid d~veloper for color electrophotography, particularly the proces~ (hereinafter referred to as the "conductlvity modulation process") of the above-cited U.S. patent, and while it is possible, of course, to produce color images eLectrophoto~raphically according to the mentioned process using already known developers, the images produced in that manner still le~ve much ~o be desired with respect to contrast, sharpness, resolution and color saturation.
Furthermore, in the production of multicolored ima~es by s~lper-positlon of severnl partial color ima~es, certain difficul.ties hav been encountered, for example, when conventional "self-fixing"
agents in known developers deposit together with color pigmen~s of a partial ima~e ~nd modify the surface of the support bearing the partial ima~e. The modification occurs in such manner that it significantly disturbs the subsequent step for formation of a nexS partial color lmage, with resultant inability to produce high quality copies of the original.
7~14 01 The above~mentioned difficulty cannot be eliminated 02 simply by omission of the fixer in the developer since other 03 essential properties of the developer are then impaired 04 unacceptably. Another requirement with respect to the dye 05 pigments of such developers lies in the fact that the images 06 produced therewith must be permanent, and light- and solvent ;07 resistant. Further, in known developers the color pigments are 08 customarily embedded in a resin shell. Such a dye pigment resin 09 mass must be pulverized to a fineness not possible by mechanical means as regards the pigments used in the developer disclosed 11 here.
12 Since no optimal developer is yet known for the 13 above-mentioned process for electrophotographic image production, ~14 the basic task of the present invention is to create a liquid developer for production of colored or multicolored images by ~16 means of electrophotography; a developer which does not exhibit 17 the named disadvantages and is particularly characterized by the 18 fact that it results in high contrast, sharp color images 19 exhibiting a high image resolution and a high color saturation, one which ensures the unobjectionable superposition of individual 21 partial color images in the production of multicolored copies.
22 The task also comprises creation of a process for production of 23 the named liquid developer.
~24 SUMMARY OF THE INVENTION:
The present invention concerns a liquid developer for 26 color electrophotography comprising an organic highly insulating 27 liquid of low polarity as dispersion medium for from about 0.1 to 2~ about 5% by weight of at least one lightfast, organic dye pigment 29 of low density and from about 0.1 to about 10% by weight of polyisobutylene having a molecular weight of greater than 1,000 31 and less than 1,000,000 as a protective polymer, at least one C, ' 01 metal soap containing a multivalent cation and a fatty acid 02 radical with 8 to 14 carbon atoms contained therein in from about 03 10-4 to about 1o-l molar quantity for c~arge control of the 04 dispersion, and Erom about 0.001 to about 1% by weight of at 05 least one hydrocarbon-soluble phenol derivative as an oxidation 06 protective agent for age stabilizing the liquid developer~
07 The invention also concerns a process for preparation 08 of a liquid developer comprising the steps of: o 09 (1 ) producing a viscous mixture of at least one lightfast, organic dye pigment of low density and polyisobutylene ~11 having a molecular weight of greater than 1,000 and less than ~12 1,000,000 as protective polymer by ~13 (2.) grinding said mixture a plurality of times in a 14 multi-roll millr (3.) a. diluting the viscous mixture obtained in step ~16 2, with an organic highly insulating liquid of low polarity while 17 agitating, and 18 b. adding in the course of the dilution at least 19 one metal soap containing a multivalent cation and a fatty acid radical with 8 to 14 carbon atoms as a charge control agent and 21 at least one hydro-carbon-soluble phenol derivative selected from 22 the group consisting oE 2,6-ditertiary butyl-4-methyl-phenol and 23 1,3,5-trimethyl-2,4,6-tris-(3,5-tertiary butyl-4-hydroxybenzyl) 24 -henzene as an oxidation protective agent for age stabiliæing the liquid developer, 26 (4.) ceasing the dilution when the dye piyment content 27 makes up 10% by weight of the solution, thereby forming a liquid ~28 concentrate storable at the specified pigment content, and 29 (5.) diluting the storable concentrate further with an organic highly insulating liquid of low polarity in a final 31 process step to obtain a concentration of dye pigment of from 32 - 3a -~J
.. . . .. .. . .. . .. .
loE~r~
01 about 0.1 to 5% by weight, of polyisobutylene as protective 02 polymer of from about 0.1 to about 15% by weight, of said at 03 least one hydrocarbon-soluble phenol derivative as an oxidation 04 protective agent oE from about 0.001 to about 1% by weight, and 05 the metal soap as charge control agent in from about 10-4 to 06 about 10-1 molar quantity, so as to make the developer ready for ~:
07 use.
09 In the following description, the invention is illustrated in more detail.
11 Liquid developers according to the present invention 12 are characterized in the ready-to-use state by the following 13 data:
;16 18 :
`19 .
~(~l37~4 01 viscosity of 1-10 cP (centipoises), 02 speci~ic resistance of 109 and 1012 ohm cm, 03 specific charge of 200~2000,~C/g (microcoulomb/gram), 04 and 05 pigment particle size of 0.1-5,~m (microns).
06 Since a liquid developer of the named typed should be ;
07 ready to use for an extended time, e.g. four weeks, it is 08 important that changes in its properties, such as irreversible -~
09 agglomeration of the dye particles, should not occur within this time span. Also, with respect to image resolution and desired 11 color saturation, it is important to select an advantageous size 12 distribution of the particles used as dye pigment. For the 13 color developer according to the invention, only those 14 substances are suitable which, after a partial color image has been deposited, have not modified the image support surface such 16 that further production of partial images is made difficult or 17 impossible. The liquid developer according to the invention 18 further ensures complete depositing of the dye pigment material 19 present during the particular image formation step at the illuminated points, the charge remaining behind on the deposited 21 partial color images being so trivial in each case that ;22 transport of already-precipitated pigment particles .
':
- 4a -~'~
1 10;37014 1 ~ by electrlc~l f~elds is no lon~er po~sible in fiubsequent lmnr,e production steps.
¦ Althou~h the liquid developer accordin~ to the invention l contain6 none of the fixer customary in known developers, the .
5 ¦ partial color images produced with the developer accordin~ to the ¦invention have proven to be sufficiently sturdy to wi~hstand ¦successive operatio~s in the ima~e production process such as ¦squeezin~ out superfluous disper~ion, rec~iving a further p~rtial ¦color image, Laminating a protectlve layer on the finished copy 10 ¦etc., without undergo~ng damage.
A liquid developer accordlng ~o the present invention ¦consists of the followin~ componentst ¦1.) Disper~ion mediums Org~nic, highly insulatin~ liquid of low 1 polarity with the following propertiess 15 ¦ specific resistance at least 1012 ohm cm dielectric constant (maximum) 4 boiling point between 130 and 1~0 C.
¦ As particular examples of materials that are effeceive, one l can list: ISOPAR E, G, and H (thes~ bein~ trademarks fo~ long 20 ¦ chain saturated hydrocarbons differing in vapor pressure, boiling point and viscosity which are commercially av~ilable from Esso), S~LLSOL (trademark for a similAr hydrocarbon supplied by Shell), kerosene, polysiLoxanes, and fluorohydrocarbons.
2,) Organic dye pigments Ligh~fast materials of low density which correspond as exactly as possible to one of the ideal subtractive basic colors (yellow, purple, blue-green) for the production of color ima~es.
particle diameter 0,1-5 ~m (microns) (5 O~L43 I den~ty (m~xlm~m 2 ~ cm Pi~r,ment materinls m~y have no pronounced photoconductlve propertles. Here, exemplary materl~Ls for utllizatlon include the followin~l Ycllow~ Dinzo dye~, prefer~bly of the bcnzidine fier~.es. .
OP~ASIN yellow 141, ~t (BASF, I.l.ldwi~sh~fen, West Ge?I~any.
~ELIO f~st yellow GRN, TM (Bayer, Leverkufien, West Germnny) (Color Index Il Pl~men~ Yellow 13lColor Index II
l0 ¦ No. 21,l00) ¦ Also usefuL, but with results somewhat inferior to the ¦ above, were the following yellow materials:
. ¦ LITHOL f~st yellow 1780, TM (BASF, Ludwigshafen, West Germany) (Color Index I: Pi~ment Yellow 83/Color Index II: - ) . ¦ ~IANS~ yellow (, 01, ~1 (~lO~CllST, ~r~nkf~lrt a/m West Germany) : ¦ (Color Index I: Pigment Yt.?llOW l/Color Index II: llfi80) GRAPIIT()L yellow GRBL, TM (S~NDOZ, Basel, ~witzerland) (Color Index I: Pi~ment Yellow 13/Color Index Ilt 2L100) Purple~ Dye l~cquers of ac~dic or b~sic xanthene dyeR, FANALR~S~ ~M 4830, I~ ASF, Ludwigshafen, We~t Germany) ; (C~lor Index 1I Pi~men~ Red 81/Color Index llt No. 45,160).
.. .,_. , Also usef~ll, b~l.t with res~lLt~ somewha~ inferior to the al~ove, were tht.~ foll.owin,lr pnrpl~? matt?ri.al~:
PIIR~ IIORNA permunent pinlc AE~lW-~5, ~1 (TI~N IIORN, ~aastricht N~therlands) (Color Index I: Pi~ment Red 81/Color Index II:
~ HEL10 fast pink E, l~ (B~YER, Leverkusen. West Germany) : (Color Intlex I: Pi~ment Red 122/Color Index II: - ) !
SANDORIN bri~liant red SBL, ~l (SANDOZ, Basel, Switzerlani) (Color Index l: Pigmen~ Red 192/Color Index Il: - ) ¦
FA~TEL red B, lM (ICI, Manche~ter, En~land) (Color Index I: Pigment Red ,81/CoLor Index II: 45160 .. , - ... ... .. ~ I
.~.
~' ' - 6 ~
~0~7~14 ~ c-r~reent ~lodlfied Ph~halocynnin~s w~lic11 are r,onphotoconduc~in~, or onl~ htly photoconductln~.
~EL10 fast blue G0, TM (~ayer, Leverku~en, West Germany) (CoLor Index I~ Pi~ment Blue 15/Color Index II~
11 No. 74,160).
Al.so usefu~, but with resuLts somewh;~t: inferior to the above, were the folLowing blue-green materials:
~';AN~O~IN blu~ 2 CLS, ~1 (SA~DO~,, Basel, Switzerland) (Color Index I: Pigment Blue l5¦Color Inclex II: 7~ 0) O~PASI~ bLue 6~7, ~ (BASF, Ludwigshafen, West ~ermany) (Co~or Index I: Pigment Blue 60/Color Index II: 69800) IR~AZ.IN btue 3 GT, ~l (CIBA-GEIGY, Basel, Switzerlan~) (~o1Or Index I: Pi~,ment Blue 16/Color In~ex Il: 741~) 13.~ C'har~,e control a~entl Metal soaps with a multivalent ca~ion ¦ and fatty acid radicals with 8 to 14 c~rbon a~.oms.
¦ Dissocia~ion constan~ IC of approximately 10 . ~s materi.aLs ¦ which have proven sultable, one can mention metal soaps such as Co^decanoate, Zr-decanoate, and Ca-decanoate (all three ¦ bein~ available commercially from SC~D0 of 7.wolle, 20 ¦ Ne~herlan~s).
Protective polymerl ~ ,h molecular wei~h~ waxy aliphatlc hydrocarbons (hereinafter referreA t.~ ~enerally as "paraffins' pa~tlcu1,arly of tho branched typn, wi~h 10~-~ M c 106 (~l bclng , the molecular weight). The protectlYe polymer serves for ¦ ndJu~tment of optlmnl vi~co~qity Ln t~le mcchnnicll~ pu1v~rl-zntion (~levatlon of the 3hear force~ ~nd thus the millln~
. ¦ efflciency) ns well as for increasin,~ stnbllity of the ¦ flnished llquid developer. The parAffin is f~ y soluble ¦ ln the dlsporsion medlum, docs not form n coatln~ on the partlcles, and has no essential fixin~ action. Furthennore, . ¦ it cnuses lit~le, if any, lnterference with the action of the ,, ¦ above-mentioned charge control agent. Thou~h other paraff ill6 l have been used su~cessfully here, a materi~l proven __ ___ ~
~ 7a~4 l pnrcic~Ilnrly sultnble ifi polyisobutylenc, 8 br~nched type ¦ paraff~n avallable comm~rcinlly under the trademark OPP~NOL .
B3 from ~ASF, Ludw~shAfen, West Germ~ny.
()ther paraffins useful as protective polymer, but with results ¦
some~h<lt inferior ~o the above were OPP~NO~ B 50, T~I (B~SF, Ludwigshafen, West Germ~ny) POLYOEL ~IUELS llO, TM (IIUE~S A~" ~Iarl, West Cermany), a p~lybutadiene IN~OPOL ~I 25, ~l (~/OCO Chemicals Europe, Geneva, SwitzerLand), t~ polybutylene HYVIS 5, ~l (BP Chemicals In~Il. Ltd., London, En~land), a poIybntylene 5.) Oxid~tion protective agent: .
~aterinlF. such 8fi hydrocarbon-soluble phenol deriva-Lives, whlch h3nder ~ rapid a~ing of the l1quid developer by oxidative processes, partlcularly at hlgher temperatures.
~xamples of the be3t such phenol derlvatlves are 2,6-di-terti~ry butyl-4-methylphenoL (~vailable commercially from Shell under the trademark IONOL CP) and 1,3,5-trimeehyl-2,4,6-tris-(3,5-di-tertiary bu~yl-~-hydroxybenzyl)-benzene (available commercially from Shell under ~lle trademark IONOX 330)- t Al so ~Isef-l- as Oxidation protective a~,en~, but with results somj what inferior to the above were IR~ROL IIV2 ~I (Cl~-G~I~Y, ~Iarienberg, West (,ermany) ~'.CINlN P, T~ (B~YER, I.everk-I~en, West Cermany~
Thé liquid developer is preferably prep~red as follows~ A
Vt 5COUS mixture of dye pi~ment and protective polymer ls prepared ¦by ~r3.nding the in~redients nt least twice in a three-rolL mill to ¦obta~n the desired size ran~e of the pi~ment partic~Les. Conven-iently, a disperfiion medium mny also be added in c~se the protectlve polymer 13 a solid. The mssq obt~lned ln this m~nner lfi then dllu~ed with difipersion medium while addlng charge control .....
; - 8 -. ~
~0~014 I agen~and oxidntlon protectlvc ~ent up to the point wllerc t~e dy~
p~gment content amounts to lO percent by welght. ~or attainment of ~ood, complete mixin~, thiG dilution may conveniently be accomplished with continuous agitation in a high frequency disperser. In th~s re~uLtant concenerated form, the liquid developer can be stored over an extended time w~thout d~teriora~io .
For preparstion of the liquld developer ready for use, a certain amount of the concentrate i~ diluted further to a desired pSgment concen~ration~ descri~ed subsequently, again under constant stirrlng.
A de~ailed formula now follows for a liquid deveLoper having the color yellow, one for the color purple, and lastly one for rhe color blue-~reent 1S Example 1 -- Yellow Liquld developer 250 ~. yellow pi~ment (Helio fast yellow GRN, Bayer) i.~
ground together two times with 750 g. OPP~NOL B3 tB.~ F) on a ~hree-roll mill to produce 1000 g. of a 25% paste. 100 ~. of . this 25,~, paste is agita~ed well with 25 ~. zirconium decano~at~
(Scado, 12~/o me~al content), 5 g. IONOL CP (Shell) diLuted to 250 g. wlth ISOPAR G (Esso), and a~itated for lO minutes with a hi~h frequency agitator. sn g~ of this 10% conc~ntrate i~
diluted with the ISOPAR G to 1000 g. and sh~ken well. In ~h~s manner, a "ready-to-use" liquid developer re~ults which contains 0.5'10 pi,gment, 1.5% OPPANOL B3 (BASF), 0.5% zirconlum decanoate (Scado) and 0.1% IONOL CP (Shell).
E mple 2 -- Purple L~quid developert All operations and weight s~atemen~ ~re the same as in the fore~oln~ flrst example with the exceptlonst instead of yellow pigment, a purple pl~ment (FANALROSA S~l 4830, BASF) is used and cobalt decanoate (Scado, 8% metaL content) is used instead of zirconium decanoate. The concentrations of the ingredi~nts of the finished purple liquid developer ready for use thus amount ~o 0.5% pi~men~, 1.5% OPPANOL B3 (BASF), 0.5% cobalt decanoate (Scado), and 0.1% IONOL CP (Shell).
10 I .
I Example 3 -- Blue-~reen Llquid developert I
¦ All operations and weight statements are the same as in the first example with the following exceptionsl blue-green (cya~
l pigment (~leLio fas~ blue GO, B~yer) i6 used ln~tead of y~low 15 ¦ pigment and 5 g. zirconium decanoate (Scado) i8 used in3tead ¦ of 25 g. zirconium decanoate.
The concentrations of the ingredients of the finished, "ready to-use" blue-æreen liquid developer thus amount to 0.5~/0 pigment, 1.5% OPPANOL B3 ~BASF), 0.1% Zirconium decanoate 20 ¦ (SCADO), and 0.1% IONOL CP (Shell).
¦ The above three liquid developers, when used in an ap~aratus ¦l~ccording to the previousLy-c$ted U.~. pa~ent, gave rise to the very best copies, these having high contrast, sharp color images with high resolu~ion and color saturation. Nearly equal results were obtained with the other materials listed when incorporated in Liquid developers of the type disclosed and used in the above-mentioned apparatus. Further, while the specific examples givcn recite particular concentrations, these are merely ~he values for th~ very best results with the materials of these examples~ ehere . I
~ 7~4 1 being a range of values in which the result~ are substantlal~y iden~ical. As ~o the remaini.ng rnateri~ls, in fiome cases the ral)~e . . depends on the p~rticul~r ones of the materl~1s which are combined.
Thus, it has been found experimentally with the materials disclosed 5 herein that copies of excellent quality can be obtained with finished liquld developers where concentration of the indivldua~
components range in amoun~ (wei~ht percent except as in~icated) --Pigment O.l to 5%, preferably Q.3 to 0.8%
¦ --Charge control a~ent 10 ~o 10 mol~r t preferably ld-3 - 10 2 molar --Pro~ective polymer 0.1 eo 10%
--Oxidaeion protec~ive agent 0.001 to 1%, preferably 0.1%.
While par~icular embodiments of the inven~ion have been shown 15 and described, modifications will be evident to those skilled in the art, and it is intended in the claims to covar all such modi~ications which fall within the spirit and scope of the invention.
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
l. A liquid developer for color electrophotography comprising an organic highly insulating liquid of low polarity as dispersion medium for from about 0.1 to about 5% by weight of at least one lightfast, organic dye pigment of low density and from about 0.1 to about 10% by weight of polyisobutylene having a molecular weight of greater than 1,000 and less than 1,000,000 as at least one protective polymer, at least one metal soap containing a multivalent cation and a fatty acid radical with 8 to 14 carbon atoms contained therein in from about 10-4 to about 10-1 molar quantity for charge control of the dispersion, and from about 0.001 to about 1% by weight of at least one hydrocarbon-soluble phenol derivative selected from the group consisting of 2,6-di-tertiary butyl-4-methylphenol and
1,3,5-trimethyl-2,4,6-tris-(3,5-di-tertiary butyl-4-hydroxybenzyl)-benzene as an oxidation protective agent for age stabilizing the liquid developer.
2. A liquid developer for color electrophotography comprising an organic highly insulating liquid of low polarity as dispersion medium for from about 0.1 to about 5% by weight of at least one lightfast, organic dye pigment of low density and from about 0.1 to about 10% by weight of at least one waxy aliphatic hydrocarbon having a molecular weight of greater than 1,000 and less than 1,000,000 as at least one protective polymer, at least one metal soap containing a multivalent cation and a fatty aeid radical with 8 to 14 carbon atoms contained therein in from about 10-4 to about 10-1 molar quantity for charge control of the dispersion, and from about 0.001 to about 1% by weight of 2,6-di-tertiary butyl-4-methylphenol as an oxidation protective agent for age stablizing the liquid developer.
3. A liquid developer for color electrophotography comprising an organic highly insulating liquid of low polarity as dispersion medium for from about 0.1 to about 5% by weight of at least one lightfast, organic dye pigment of low density and from about 0.1 to about 10% by weight of at least one waxy aliphatic hydrocarbon having a molecular weight of greater than 1,000 and less than 1,000,000 as at least one protective polymer, at least one metal soap containing a multivalent cation and a fatty acid radical with 8 to 14 carbon atoms contained therein in from about 10-4 to about 10-1 molar quantity for charge control of the dispersion, and from about 0.001 to about 1% by weight of 1,3,5-trimethyl-2,4,6-tris-(3,5-di-tertiary butyl-4-hydroxybenzyl)-benzene as an oxidation protective agent for age stabilizing the liquid developer.
4. A liquid developer for color electrophotography comprising an organic highly insulating liquid of low polarity as dispersion medium for from about 0.1 to about 5% by weight of at least one lightfast, organic dye pigment of low density and from about 0.1 to about 10% by weight of polyisobutylene having a molecular weight of greater than 1,000 and less than 1,000,000 as a protective polymer, at least one metal soap containing a multivalent cation and a fatty acid radical with 8 to 14 carbon atoms contained therein in from about 10-4 to about 10-1 molar quantity for charge control of the dispersion, and from about 0.001 to about 1% by weight of at least one hydrocarbon-soluble phenol derivative as an oxidation protective agent for age stabilizing the liquid developer.
5. Process for preparation of a liquid developer comprising the steps of:
(1.) producing a viscous mixture of at least one lightfast, organic dye pigment of low density and polyisobutylene having a molecular weight of greater than 1,000 and less than 1,000,000 as protective polymer by (2.) grinding said mixture a plurality of times in a multi-roll mill, (3.) a. diluting the viscous mixture obtained in step 2, with an organic highly insulating liquid of low polarity while agitating, and b. adding in the course of the dilution at least one metal soap containing a multivalent cation and a fatty acid radical with 8 to 14 carbon atoms as a charge control agent and at least one hydro-carbon-soluble phenol derivative selected from the group consisting of 2,6-ditertiary butyl-4-methyl-phenol and 1,3,5-trimethyl-2,4,6-tris-(3,5-tertiary butyl-4-hydroxybenzyl) -benzene as an oxidation protective agent for age stabilizing the liquid developer, (4.) ceasing the dilution when the dye pigment content makes up 10% by weight of the solution, thereby forming a liquid concentrate storable at the specified pigment content, and (5.) diluting the storable concentrate further with an organic highly insulating liquid of low polarity in a final process step to obtain a concentration of dye pigment of from about 0.1 to 5% by weight, of polyisobutylene as protective polymer of from about 0.1 to about 10% by weight, of said at least one hydrocarbon-soluble phenol derivative as an oxidation protective agent of from about 0.001 to about 1% by weight, and the metal soap as charge control agent in from about 10-4 to about 10-1 molar quantity, so as to make the developer ready for use.
(1.) producing a viscous mixture of at least one lightfast, organic dye pigment of low density and polyisobutylene having a molecular weight of greater than 1,000 and less than 1,000,000 as protective polymer by (2.) grinding said mixture a plurality of times in a multi-roll mill, (3.) a. diluting the viscous mixture obtained in step 2, with an organic highly insulating liquid of low polarity while agitating, and b. adding in the course of the dilution at least one metal soap containing a multivalent cation and a fatty acid radical with 8 to 14 carbon atoms as a charge control agent and at least one hydro-carbon-soluble phenol derivative selected from the group consisting of 2,6-ditertiary butyl-4-methyl-phenol and 1,3,5-trimethyl-2,4,6-tris-(3,5-tertiary butyl-4-hydroxybenzyl) -benzene as an oxidation protective agent for age stabilizing the liquid developer, (4.) ceasing the dilution when the dye pigment content makes up 10% by weight of the solution, thereby forming a liquid concentrate storable at the specified pigment content, and (5.) diluting the storable concentrate further with an organic highly insulating liquid of low polarity in a final process step to obtain a concentration of dye pigment of from about 0.1 to 5% by weight, of polyisobutylene as protective polymer of from about 0.1 to about 10% by weight, of said at least one hydrocarbon-soluble phenol derivative as an oxidation protective agent of from about 0.001 to about 1% by weight, and the metal soap as charge control agent in from about 10-4 to about 10-1 molar quantity, so as to make the developer ready for use.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP2528339.0 | 1975-06-25 | ||
| DE2528339A DE2528339C3 (en) | 1975-06-25 | 1975-06-25 | Electrophotographic suspension developer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1087014A true CA1087014A (en) | 1980-10-07 |
Family
ID=5949933
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA255,613A Expired CA1087014A (en) | 1975-06-25 | 1976-06-24 | Liquid developer for color electrophotography and process for preparation of the same |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4155862A (en) |
| JP (1) | JPS5857109B2 (en) |
| CA (1) | CA1087014A (en) |
| CH (1) | CH601843A5 (en) |
| DE (1) | DE2528339C3 (en) |
| FR (1) | FR2315709A1 (en) |
| GB (1) | GB1542143A (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61134134U (en) * | 1985-02-08 | 1986-08-21 | ||
| US4820605A (en) * | 1987-11-25 | 1989-04-11 | E. I. Du Pont De Nemours And Company | Modified liquid electrostatic developer having improved image scratch resistance |
| US4946753A (en) * | 1988-12-02 | 1990-08-07 | Minnesota Mining And Manufacturing Company | Liquid electrophotographic toners |
| US4925766A (en) * | 1988-12-02 | 1990-05-15 | Minnesota Mining And Manufacturing Company | Liquid electrophotographic toner |
| US5153090A (en) * | 1990-06-28 | 1992-10-06 | Commtech International Management Corporation | Charge directors for use in electrophotographic compositions and processes |
| KR100186872B1 (en) * | 1989-05-23 | 1999-05-01 | 앤드류 가르만 | Stain elimination in consecutive color toning |
| US5262259A (en) * | 1990-01-03 | 1993-11-16 | Minnesota Mining And Manufacturing Company | Toner developed electrostatic imaging process for outdoor signs |
| US5061583A (en) * | 1990-01-19 | 1991-10-29 | Minnesota Mining And Manufacturing Company | Color electrophotography for high quality half-tone images |
| US5342720A (en) * | 1993-04-28 | 1994-08-30 | Minnesota Mining And Manufacturing Company | Color proofing element and process for making the same |
| US6301055B1 (en) | 2000-08-16 | 2001-10-09 | California Institute Of Technology | Solid immersion lens structures and methods for producing solid immersion lens structures |
| AUPR906101A0 (en) * | 2001-11-26 | 2001-12-20 | Research Laboratories Of Australia Pty Ltd | Liquid developers |
| US7042649B2 (en) | 2003-08-11 | 2006-05-09 | California Institute Of Technology | Microfabricated rubber microscope using soft solid immersion lenses |
| CN102680440A (en) | 2004-06-07 | 2012-09-19 | 先锋生物科技股份有限公司 | Optical lens system and method for microfluidic devices |
| US7556907B2 (en) | 2005-06-03 | 2009-07-07 | Seiko Epson Corporation | Liquid developer |
| US8329372B2 (en) | 2006-07-14 | 2012-12-11 | Seiko Epson Corporation | Liquid developer, method of preparing liquid developer, and image forming apparatus |
| JP2013072983A (en) * | 2011-09-27 | 2013-04-22 | Fuji Xerox Co Ltd | Liquid developer, developer cartridge, process cartridge, image forming device and image forming method |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3253913A (en) * | 1960-10-13 | 1966-05-31 | Eastman Kodak Co | Process for color electrophotography |
| US3259581A (en) * | 1961-11-23 | 1966-07-05 | Australia Res Lab | Liquid developer for electrostatic images |
| US3971659A (en) * | 1968-12-28 | 1976-07-27 | Xerox Corporation | Color electrophotographic process using photoconductive particles in liquid developer |
| US3852208A (en) * | 1968-12-30 | 1974-12-03 | Canon Kk | Photoconductive toner composition |
| CH548056A (en) * | 1972-06-30 | 1974-04-11 | Turlabor Ag | METHOD AND DEVICE FOR ELECTROPHOTOGRAPHIC IMAGE GENERATION AND APPLICATION OF THE METHOD. |
| JPS5033862B2 (en) * | 1972-10-21 | 1975-11-04 | ||
| DE2262603C2 (en) * | 1972-12-21 | 1982-04-01 | Hoechst Ag, 6000 Frankfurt | Electrophotographic suspension developer |
-
1975
- 1975-06-25 DE DE2528339A patent/DE2528339C3/en not_active Expired
-
1976
- 1976-01-30 CH CH61076A patent/CH601843A5/xx not_active IP Right Cessation
- 1976-04-13 FR FR7610779A patent/FR2315709A1/en not_active Withdrawn
- 1976-04-13 JP JP51041765A patent/JPS5857109B2/en not_active Expired
- 1976-04-15 GB GB7615539A patent/GB1542143A/en not_active Expired
- 1976-06-21 US US05/698,389 patent/US4155862A/en not_active Expired - Lifetime
- 1976-06-24 CA CA255,613A patent/CA1087014A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| CH601843A5 (en) | 1978-07-14 |
| US4155862A (en) | 1979-05-22 |
| FR2315709A1 (en) | 1977-01-21 |
| DE2528339A1 (en) | 1976-12-30 |
| DE2528339B2 (en) | 1978-05-18 |
| GB1542143A (en) | 1979-03-14 |
| JPS5857109B2 (en) | 1983-12-19 |
| JPS524841A (en) | 1977-01-14 |
| DE2528339C3 (en) | 1979-01-18 |
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