DE1622374A1 - Electrophoretic imaging process - Google Patents

Description

SU;

XEROX CORPORATION ■

Rochester, IY 14605
UNITED STATES

Electrophoretic imaging methods

The invention relates generally to imaging methods and especially electrophoretic imaging techniques.

An electrophoretic imaging process for producing color images using photoconductive particles has been developed. This process is described in patent application X 57 'TXa./57β .

In such a method, different colored, light-absorbing Particles in a non-conductive liquid carrier

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suspended. The suspension is placed between electrodes, exposed to a potential difference and exposed to an image. Once these steps have been carried out, a selective one takes place •. Particle migration in an image-like "distribution, whereby on a ' or both electrodes create a visible image. An essential one. The suspended particles are the moment of this process. It must be brightly colored particles that are sensitive to light and which are apparently activated by radiation change their charge polarity and join one of the electrodes work. ,,

In a single-colored "process - single-colored particles in" ^ a carrier liquid dispersed and with a black and white image exposed The result is a monochrome image corresponding to according to the usual black and white photography. With a multicolored one Processes are used to produce color images, 'because mixtures of two or more different colored dyes are used, each for light of a certain wavelength or P of narrow wavelength ranges are sensitive. In such multicolored .Verfahren the particles are chosen so that those for different colors on different wavelengths in the visible spectrum, according to their main absorption bands, speak to. The dyes should also be chosen so that their spectral curves do not overlap to a large extent Color separation and the development of a complementary multicolored Enable image. In a typical complementary multicolored process, the particle dispersion contains cyan

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bene, mainly red-sensitive epidemics, mainly green-sensitive magenta particles and yellow, mainly blue-sensitive particles. """-"".-.'.-: - '■ ... ■"

With the above-described imaging process, images of good quality can generally be produced which, in the case of multicolored modification, have a good color balance. However, many dyes are not sufficiently photosensitive to respond to exposure to the image in a reasonable amount of time by this method. Furthermore, different dyes have the ability to produce images with different image contrasts. There are therefore many problems in the selection of dyes for the 3 possible application. For example, the production of an image with strong contrasts, for example to achieve a striking effect, may be desired in an imaging process, or it may be _a nn an image with low contrasts - desirable s ^ a, if a pastel-like original is to be copied .. -

Processes for changing the light sensitivity of the electrophoretic image particles and for changing image contrasts in monochrome and multicolored electrophoretic imaging processes are therefore necessary. _:

It is an object of the invention to provide an electrophoretic imaging method create the above mentioned disadvantages avoids. ,

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Furthermore, a method for changing contrasts in electrophoretic imaging methods is to be created.

It is also intended to provide a method for changing the sensitivity to light are created by electrophoretic image particles.

It is also intended to provide a process for the production of electrophoresis Images with better contrast can be created.

In addition, an improved electrophoretic image suspension is to be created.

This and other things are achieved according to the invention in that sensitizing amounts in the electrophoretic process a charge transfer sensitizer made from an electron acceptor or donor, usually as Lewis acids and Lewis liquors designated, are present. The sensitizer can be on adsorbed on the surface of the image particles or on the surface given to one of the electrodes.

Any suitable electron acceptors or donors can be used v / earth. In some cases where the artwork is amphoteric, charge transfer complexes can be formed with both Lewis acids and Lewis liquors. Typical elephant electron acceptors (Lewis acids) contain: 2,4,7-trinitro-9-fluorenone, 9-mcyanoanthylene, 2,4,7 * -trinitrofluorene, 4,4-bis (dirnethylamino) benzphenone, tetrachlorophthalic hydride, Ohloraiiil, picric acid, picryl chloride, benz (a) anthracene-7,12- ction, 1 ^, S-'J'rlnitrobenzen, 6-nitrospiropyran, 6,8-dinitrospiro-

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pyran .; Quinones such as p-benzehinone, 2,5-dichlorobenzeneQn, 2,6-dichlorobenzeneOn, chloranil, naphthoquinone- (1,4), 2,3-diehlornaphthoquinone- (1, 4), Änthraehinone, 2-methylanthraquinone, ί, Α - Diinethyianthraquinone, I-ghloranthraohinone, ani7hraquinone-2-earboxylic acid _? 1,5-dichloroanthraquinone, 1-chloro-4-hitroanthraquinone, phenanthrene-ehinone, acenaphhenquinone, pyranthrenequinone, ghrysenequinone. Thi ο-naphthenquinone, anthraquinone-1,8-disulpho3 acid and anthraquinone - ^ - aldehyde; Triphthaloylbenzene; Aldehydes such as bromal, 4-l ^ itrobenzaldehyde, 2, e-dichlorobenzaldehyde, 2-lthoxy-1-naphthaldehyde, anthracene-9-aldehyde, pyrene-3-aldehyde, oxindole-3-aldehyde, byidine-2,6-dialdehyde, Biphehy; 1 ^ 4-aldehyde; organic phosphorous acids such as ^ -Clilor-J-nitro-benzene-phosphoric acid, polyprophenols such as 4-nitrophenol, and picric acid; Acid anhydrides ,; "for example acetyl anhydride, succinic anhydride, corn anhydride, phthalic anhydride, {Getrachlorphthalanhydrid, Perylen-3, 4, .9-f1-0-Te.1>rakar-" bonsäure and Ghrysen-2,3,8,9-te. tracarboxylic anhydride, di-bromo, malic anhydride; Metal halides of metals and ifetalloids of groups IB, II "to VIII of the periodic table, e.g. aluminum chloride, zinc chloride, cast iron, tin tetrachloride, (^ tannichlorid), arsenic trichloride, stannous chloride, antiinone pentachloride, magnesium chloride, magnesium bromide, caleiumbroinium, GaI, Ghrombromid, Manganehlorür, Kobaltchlorür, Gabaltchlorid _f Gupribromid, Gerichlorid, thorium chloride, Ärsentrigodid; Borhalogenidverbindungen, eg * boron trifluoride and boron trichloride, and ketones, such as acetophenone, Benzphenon, Perfluorobenphenon _r 2-Acethyl-naphthalene, benzoin, 5-Benzoylac enaphthen benzil, Bi ac endion, 9 -A oebhy 1-an t hr ac en, 9 -benzoyl-anthrac en, 4- (4-iimethyl-amino-cinnamoyl) -1-acetylbenzene, acetoacetic acid-

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anilide, indion- (1,3), (1-3 diketo-hydridenJ, acenaphthenequinone dichloride, Anisil, 2,2-PjTrIdIl and Furil.

Other Lewis acids are mineral acids such as the hydrogen halides, sulfuric acid and phosphoric acid; organic carboxylic acids such as acetic acid and its substitution products, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, phenylacetic acid and 6-methylcoumarinyl acetic acid (4); Malic acid, cinnamylic acid, phenylformic acid, 1- (4-diethylamine-benzoyl) -benzene-2-carboxylic acid, phthalic acid and tetra-chlorophthalic acid, alpha-beta-dibromo-betaformyl-acrylic acid, (muco-bromic acid), dibromomalic acid, 2- Bromophenylformic acid, gallic acid, 3-ititro-2-hydroxyl-1-phenylformic acid, 2-nitro-phenoxy-acetic acid, 2-nitro-pheny! Formic acid, 3-Mtro-phenylamelic acid, 4-Mtro-phenyl-formic acid, 3-nitro-4- ethoxy-phenylameisensäure, 2-chloro-4-nitro-phenylameisensäure 1, 2-Ghlor-4-nitrd-phenylameisensäure 1, 3-mtro-4 ^{1-methoxy-phenylameisensäui} * e _r 4-nitro-1 ~ methyl-phenylameisensäure, 2-chloro-5-nitro-1-phenylformic acid, 3-chloro-6-nitro-1-phenylformic acid, 4-chloro-3-nitro-1-phenylformic acid, 5-chloro-3-nitro-2-hydroxyphenylformic acid, ^ - Chlorine-hydroxy-phenyl-formic acid, 2,4-dinitro-1-phenyl-formic acid, 2-bromo-5-nitro-phenyl-formic acid, 3-chlorophenyl-acetic acid, 2-chloro-cinnamic acid, 2-cyano-mono-amylic acid, 2,4-dichlorophenyl formic acid , 3,5-Dinitro-phenylformic acid, 3,5-Din itro-acylic acid, malonic acid, mucic acid, aceto-salicic acid, benzilic acid, butane-tetracarboxylic acid, citric acid, cayane-acetic acid, gyelo-hexane-dicarboxylic acid, cyclohexane-carboxylic acid, 9,10-dichloro-stearic acid, jumaric acid, Itaconic acid, levulin

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acid, malic acid, succinic acid, alpha-idroma-si; earic acid ,; ~; ... citraconic acid, ilibromosuccinic acid, yrene-2,5,7, S-tetra-carboxylic acid, tartaric acid; Organic Sülfönsäuren such as ^ - iDoliioiLsulfönic acid and Benzensulf "önÄurev 2,4 ^ I) initro-1H3lethyl · -ΐ>en2en> -6-sulphonic acid, 2 :, 6? -Dinitro- <1 -0iydro ^ -benzen-4-- sulfanic acid, 2-uritro-1-hydrpxy-benzene-4-sulfonic acid, 5- ^ itrö-2-ynethyl-1-hydroxy-lien- · zen-5-sulfonic acid, 6 ^ itro-4Hniethyl-1 ^^ ά ^ ^^ acid,, 4-chloro-1H ^ dro ^ -benzen-3 ~ sulphonic acid,; ^ - 1-methyl-ldenene-5- ^ sIiIfönäure und ^^ 2-Ghlör-t-möthyl-t) ehzen-4- ⁱ sulfönsäure; ".- .. ■ - '\' ■ -": _ / ^-:;. ■ "; - -; ; : 7 - ^; -

Typical electron donors include: i-detramethyl-p-phenylenediarain; p-dimethoxybenzene, ^ r ^ 2.2 ^T ^ inaphthylamine; 2,3j.5-tri-phenylpyrrole; K-hexamethylhenene; Mbenzofuran; Dibutylamine; Triphenylamine, Iriäthylamin;. ■■ "ΙΤ., ΪΓ ^T -i) ioctyl-i, 5 ^ iaminnaphthaiin ^ triphenyiphosphinei ethyldioctylphosphine; 1,4 ^ bis - (^ iäthylphosphin) ■ -benzen ^: l ^ ammoniuiQjödid; methyltrimethylan; Xthyltrimethylan tri-n ■ -propylammonium iodide; tetramethylainmöniuiiihydroxid; copper salicylaldiamine; cobaltpyrrolealdehydeimine Mckel - ^^ methoxysaliizyl ^ oxini; copper-5-methoxy-8-quinolinoa1; ; 2 ^ Mei ^ oxyphenazine ';Äenetiden; H, B-diethylanisidine;'Ghrysen;Qoronen; 2-Äthylphenan-bhren and mixtures of these. = '' ■ - ■ 'y -';

I) Ie image particles can be any material with the above required color and spectral sensitivity

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keep. Purely monochrome images are usually black or almost black particles, while eyan, magenta, and yellow particles are preferred for complementary images. Typical dyes contain: 1,2,5,6-Di (C, C · -diphenyl) -thiazol-anthraquinone; 1 - (4'-ethyl-5 ^l -chlorazobenzene-2'-sulfonic acid) -Z-hydroxy-S-naphtholic acid; Calcium lake of 1- (2'-azonaphthalene-1L-sulfonic acid) -2-naphthol; Phthalocyanine j 3,3'-methoxy-4-4'-diphenyl-bis (1 "-azo-2! ^L -hydroxy-3" -naphthanili ^ calcium varnish of 1- (4'-methoxyazobenzene) -2'-sulfonic acid ) -2-hydroxy-3-naphtholeic acid; Molybdenum lacquer from 3,6- "bis- (diethylamino) -9,2 '-carbethoxypheynlxanthenoniumchlorid; 4,1 Ö-dibroin-6,12-anthaeahthron; dichlor-9,18-isoviolanthron;"Flavanthrpn; Phosphotungstomolybdenlack of 4- (S ₁ H ¹ , IT ^I -Trimeth3rlanilin) -methylene- Ή " , N ^{! L} -dimethylanilinurachlorid; 1- (2 · -Methoxy-5'-nitrophenylazo) -2-hydroxy-3" -nitro- 3-naphthanilidj ghinacridone; 3,3'-Dimethoxy-4,4'-biphenyl-bis- (1 "-phenyl-3 ⁿ -methyl-4" -azo-2 "-pyrazoline-5"-ein; and mixtures of these. Other typical dyes are contained in application X 37 IXa / 57e.

Any suitable insulating liquid can be used as the carrier for the image particles in the process. Thermal insulating liquids contain decane, dodecane _t ΪΓ-tetradecane, paraffin, beeswax or other thermoplastic materials, general-purpose alcohol solvents such as Sohlο Odorless Solvent 3440 (a kerosene fractionation product from the Standard Oil Company of Ohio), Isopar-G- (a long chain, saturated, ali- ' - Phatic hydrocarbon from the Humble Oil Company of New Jersey)

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and mixtures of these substances ¹ .-; .- "'';' ■

The electrophoresis; ' ITSMldungsverfäKren according to the 'invention is explained in more detail with reference to the figure. This shows'^; Thus a device for carrying out the method according to the invention, ■ "". ""'■■".- ■ -".'-"./ ■ -'" .- ^: '■ "'". . "-: - ■" ■ "■■ · '■" - ■■■■

The electrode 1, which is transparent in this exemplary embodiment, is present from a layer of optically transparent glass 2, which with a thin, optically transparent layer 3 of tin oxide is coated. Such material is made by Pittsburgh Glass Company sold under the Warning NESÄ Glass. This electrode. is hereinafter referred to as "induction electrode" The surface of the detection electrode 1 is thin Layer 4 of dispersed in an insulating, liquid oil carrier, finely divided: photosensitive particles. The term "photosensitive" in this case refers to the properties of the! particles, once from the injection electrode attracted to themselves under the influence of an applied electrical Field to move away from the injection electrode when exposed to effective electromagnetic radiation. For a detailed theoretical explanation of this process, reference is made to patent application X 57 IXa / 5'7'e. The liquid one Suspension 4 'can also act as a binder for the dye particles included, at least partially in the Süspensiohs- or Carrier liquid is solvable, as will be explained later. Near & e £ liquid suspension. 4 there is a second elec-

bath

trode 5, .di.e in the following ^ is referred to as "blocking electrode", which is connected to one side of a voltage source 6 via a switch 7. The other side of the voltage source 6 is connected to the injection electrode 1, 'so that when closing .of the switch 7 an electrical PeId to the liquid suspension 4 is placed between electrodes 1 and 5. An image projector comprising a light source 8, a slide 9 and a lens 10 is used to expose the dispersion 4 with a light image of the original slide to be copied 9. The electrode has the shape of a roll with a central conductive conductor 11, which is connected to the voltage source 6. The middle conductor is with a layer of barrier electrode material 12, for example Baryta paper, covered. The dye suspension is with the image to be copied exposed, while by closing the switch 7 between the injection and the barrier electrode a Voltage lies. The roller 5 is over the surface of the injection electrode 1 moves, the switch 7 during the exposure time closed is. This exposure causes the exposed particles originally adhering to the electrode , migrate through the liquid and onto the surface of the barrier electrode adhere, causing on the surface of the injection electrode what remains is a dye image that is a duplicate of the original slide 9 is. After exposure, it evaporates proportionally easily evaporable carrier liquid and leaves behind the dye image. This can be fixed at this point are, for example, by covering with a layer or by taking effect of the binding dissolved in the carrier liquid.

the material, such as earaffin wax or other suitable; Binders which fall out of the solution if ■■ äi.e; - "'Ta? Äger £ iiisä ^; i: ^ keiV = Ter.döimpft» .. Good results were achieved with about 5 Ms 6 percent by weight of paraffin binders »; - ! Di.e:. ^ Rägeril1is; äigkei ^ seXi3S ^ \ fcaiin paraffin wax or another suitable 3inder: his * Another possibility is to question the substance image left on the injection electrode towards a moving surface As will be explained in more detail later, this process can be used to produce both monochrome and multicolored images, depending on the type and number of dyes suspended in the carrier liquid and on the strong color that the suspension is etched during the process ^ produced ". "" - .: '...-'-. ^; \. "ϊ:"".", · ..- ---. ,; .- ^ ^ΐ: / _-_; -: - ■ -} ". ■■, .-""■ ■

In the case of a one-color process ^: particles of one texture are dispersed in the carrier liquid and exposed to a "white" image. According to the usual black and white photography, an image of one color is created In a multicolored process, the particles are selected in such a way that those of different colors, corresponding to their main absorption bands, respond to different panel lengths in the visible spectrum. Furthermore, the: dyes should be chosen so that their spectral sensitivity curves η overlap., - thus color separation and complement In a typical multicolored process the particle dispersion contains cj; partially colored, mainly red-sensitive particles, lean colored, mainly green-sensitive particles.

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borne "particles and yellow, mainly blue-sensitive particles. If these are mixed with one another in the carrier liquid, this creates a liquid that looks black. Will one or more of these types of particles causes the G-rundelekt.rode T migrate to the upper electrode, they leave behind particles that produce an ear.be that corresponds to the color of the incident light. For example, it causes an exposure with red light so that the cyan dye migrates while the yellow and magenta dye remain, which will appear red in the finished image. In the same way, removing red and magenta, respectively, turns blue and green Color generated. If white light falls on the mixture *, wander all dyes and leave the color of the white or transparent carrier. If there is no exposure, all the dyes remain and a black color is produced. Image. this is an ideal complementary color process because the particles not only each have a composition, but also that have both functions of the final image color and the photosensitive medium.

Any suitable different colored, light-sensitive dye particles with the desired spectral properties can be used together with the dyes according to the invention for the preparation of a dye mixture in a carrier liquid for color images. Good results have been obtained with about 2 to 10 weight percent dye. ■ _:.

009843/155

The amount of the sensitizer changes according to the desired effect. Increasing the amount of sensitizer generally increases the sensitivity of the process and the. Image contrast. In general, very small amounts give very good results. · Ν _:

The one described above, a charge transfer complex forming sensitizers are appropriately added in the imaging process. The sensitizer can be dissolved in a solvent that dissolves it but does not alter the image particles. The image parts will be then brought into the solution and the solvent evaporated. Those carrying the adsorbed sensitizer coating Image particles are then dispersed in the carrier liquid. Another possibility is to apply the sensitizer to one of the electrodes prior to imaging. In addition, the sensitizer may be incorporated in the raw material from which the image particles or the electrodes are made.

The following examples explain the invention in more detail in relation to the use of charge transfer complexing sensitizers in electrophoretic imaging processes. The examples show various preferred exemplary embodiments of the electrophoretic mapping method according to FIG the invention.

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All of the following examples are carried out with one facility- ,, as shown schematically in the figure. the Image mix is provided as a coating on a NESA glass slide, through which the exposure takes place. The surface of the NESA glass is in series with a switch, a voltage source and the conductive center conductor of a roller which has a coating of baryta paper on its surface. the Roll, has a diameter of about 6.35 cm and comes with about Moved 4 cm per second over the plate surface. The plate is about 10 cm χ 10 cm tall. It is exposed to an illuminance of around 1614 lux (measured on the uncoated. Surface of the NBSA glass). Unless otherwise stated, in each example 7 percent by weight of the specified Dye dissolved in Sohio Odorless Solvent 3440, and the The amount of applied voltage is 3000 V. In each example, in which a monochrome image is made, the particle suspension becomes with a standard black and white slide. In each multicolored multicolored example, the particle suspension is represented by a standard "Kodachrom" slide exposed to a multicolored image. In addition to this image exposure each suspension examined is exposed through a neutral 0.3 density wedge filter in order to increase the sensitivity of the Measure suspension. Since the sensitivity is related to the speed without sensitization by the addition of Sensitizers are magnified in each example the speed changes are given as multiples of the speed without sensitization.

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~ Λ ⁵ -

■ A first 'dispersion becomes; by cn suspend: from 7 parts of the X-shape of the metal-free Phth ^

Odorless Solirent 34-0 _; Hergesirellt, about T ropes of the ^ XS ¹ Orm of the PhT-halocyandLns are put in; e.a solution of about 0. θχ ^ & Ώ.ώτ tetramethyl-p-pnenj-Tjidiarnin in 100 files of methanol

the methanol evaporates, leaving the tetram on the surface; the leilchen -adsorbed zürüclci about 7; Parts of this treated sample are dispersed ϊύι about MOO parts Sohio Od-orless Solvent 34-40. Each suspension: is applied as a coating to a TNESJb glass ^^ support and exposed as described above. In gedem "case is eift. ■ dem ^ 5rig ± nalt ^; ..e.iijfes-5r-eche3i '-. Of the image on the HESA glass; present," The wedge filter areas of the image show that the visualized' larbs ^ off> about ^ times faster than · the unsensitized ear substance. *: - _;

The experiment from Example I is repeated, the methanol solution

"■". "'■ - ■■■ ■■■■':. ^:: .." -. ' ^: ': - ^{: V} -; "-. R;" - - en: '- ".---- V-' contains Jedach instead of" Tetr ^ ethyl ^ p-phenyjaiamlh about ^; .0.007 parts p- ^ Dimethoxsbenzen. In this room the sensitized dye is about twice as fast as: the unsensitized dye. V; :. -; : - ::: _ ^: / ^: - ^; V _; ; . '. ' ^::: ': V ^? "

"■■"". .- ■■ _: ■"".". Example III. / λ / - ^,;

The experiment from Example I is repeated, the methane solution but instead of voä contains tetramethy ^^

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0.02 part of chloranil. In this case the · sensitized Dye about twice as fast as the unsensitized one.

Example IV

The experiment from Example I is repeated, the methanol solution

- en

However, instead of / of tetramethyl ~ p-phenyllra.iamine contains about 0.01 part iodine. The sensitized dye is about 4 times faster than the unsensitized. In addition, the contrast of the image made with the sensitized dye is much .greater.

Example V.

A suspension is made by dispersing about 5 parts of Monolite Fast Blue GS, a mixture of the Alphor and Eeta forms of the metal-free phthalocyanine from the Arnold Hoffmann Company, about 3 parts Watchung Red B and about 2 parts N-2 "-pyridyl-; 8,13-dioxodinaphto (1,2-2 ', 3') -furan-6-carboxamide in "about 100 Share Sohio Odorless Solvent made. About 500 parts of Sohio Odorless Solvent 344-0 is 0.03 part of 2,4,7-trinitro-fluorenone added. A NESA carrier is moistened with it and in the oven dried at about 100 ° C. The treated WESA carrier is then covered with the above suspension. The image produced on the treated support is about 10 times as fast as the image on the untreated carrier. ■

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Example YI ·, ·;

About 4 parts of Krylon, an acrylic ester from Krylon Inc., ¥ orris-. town, Pennsylvania, is dissolved in about 20 parts ai of toluene. About 0.02 parts of 2,4,7-trinitro-9-fluorenon are added to this solution. When this solution is used, an IESI & load carrier is coated and dried. The dry coating has a thickness of about 0.0762 mm. A multicolored suspension is produced as in example IT. Sin portion of this solution is brought to the treated carrier, while another part atif brought the untreated carrier%. An image is formed on the plates as described above. The image produced on the treated plate is about half as fast as the image on the untreated support.

Example ¥ 11

About 10 parts of Bakelite Polysulfone P 1700, a polysulfo resin of the Union Garbide Corporation, about 200 parts of dichloromethane are used solved. About 0.03 parts of 2,4,7- " Trinitro-9-fluorenone added. This covers a FESA carrier and dried. The dry layer has a thickness of about 0.0762 mm. A multicolored dye suspension is et like made in Example T. Kit becomes part of this · suspension the treated NESA carrier coated while with another Part of an untreated carrier is coated. An image is formed on the plates as described above. Like that As can be seen in the wedge filter areas of the images, the treated plate is about 6 times faster than the untreated one.

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Example YIII -

A NESA carrier is handled and images are generated as in Example Y. Instead of 2,4,7-trinitro-9-fluorenone however, 9- (dicyanomethylene) -2,4 ", 7-trinitro-.fluoren. used as sensitizer. In this case the sensitized plate is about 4 times faster than the unsensitized one.

Example IX ^: '

About 0.02 parts of 2,4,7-trinitro-9-fluorenone will be in about 500 Share Sohio Odorless Solvent 3440 dispersed. The ones with barytr paper coated barrier electrode is moistened with this solution. A multicolored suspension is prepared as in Example V, placed on a NESA slide, and it becomes a Image generated. When producing a second image, untreated baryta paper is used for the barrier electrode. The sensitized Arrangement is about 3 times faster than the unsensitized one.

Example X

About 5 parts of Krylon are dissolved in about 20 parts of toluene. This The solution is about 0.02 parts of 2,4,7-trinitro-9-fluorenone added. The solution is applied to the baryta paper of the barrier electrode in a thickness of about 0.05 mm. A multicolored one Image suspension will be like. made in Example Y. A part of it is placed on a NESA carrier. Using this Two images are produced, one with the suspension

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sensitized barrier electrode and; another; with a common electrode. The sensitized barrier electrode increases the sensitivity by about the lafctpr -2 / V _:

'"; .. ■ .- .; ■' ■ ';. .. ^Example XI ^T:" .. "...- - / Tv'-;■.''■;,

Five samples are prepared, each of which consists of about 7 parts of finely divided 1-2 "-pyridyl · ^, 13-dioxodinaphto-Ci, V2-2: ¹ , 3 ') -furan-carboxamide, suspended. - approximately 100 parts of methanol exist. The first is not treated; 0.0005, 0.01, 0.02 and 0/04 parts of iodine are added to each of the other four. The samples are heated to evaporate the methanol Various types of iodine adsorb on the particles. The samples are then, as described above, suspended in about 100 liters / Sohio: Odorless Solvent 3440. The increase in the iodine content results in a very slight increase in sensitivity is increased considerably with an increase in the iodine content. - _v "- ^:

In the preceding examples, based on electrophoretic Mapping process different compositions and Describe conditions. Other suitable materials can as mentioned above, can be used with similar results. Furthermore, the image suspension, _ the light-sensitive Particles; and the electrodes: other substances "are added to to strengthen their properties, to improve them or to others Way .'- to change. The parquet compositions can be

for example made color-sensitive or with other both organic as well as inorganic photosensitive substances are mixed or combined.

Knowledge of the skill in reading this specification will be apparent to those skilled in the art other- modifications and variations, all under the Invention fall.

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Claims (1)

Claims An electrophoretic imaging process in which: a layer of a suspension containing a plurality of finely divided particles of pure color is exposed to an electrical EeId: between two electrodes, at least one of which is partially transparent; is-tyvüncl · "in which the suspension is exposed at the same time through the ^ partially transparent electrode with an image of activating electromagnetic radiation, whereby on at least one of the electrodes a material image is generated from migrated particles, characterized in that the particles or at least one of the electrodes (1 _f 5) a sensitizing agent from the group of Lewis acids and ^ = EeWiBlaugeh; ⁷ wear or; contain. 2, imaging method according to claim 1 * characterized in that that the sensitizing agent adsorbs on αέη particles 3, mapping process according to adaptation, thereby marked eichnetj dam the sensitizer as a coating on a of electrodes O / 5) is / VV '-.' ■ '. 4-, imaging process according to claim "*> _v , characterized in that the sensitizing agent is added to a resin binder 5. Imaging method according to claim 3 or 4, characterized in that that the coating is applied to the injection electrode (1) will. 6. Imaging method according to claim 3 or 4, characterized in that that the coating is applied to the blocking electrode (5) will. " Wk- 7 · Imaging method according to one of the preceding claims, characterized in that 2,4,7-trinitro-9-fluorenone is used as the sensitizing agent. 8. Imaging method according to one of claims 1 to 6, characterized characterized in that iodine is used as a sensitizer. ·. 9. Imaging method according to one of the preceding claims, ^ characterized in that the particles are yellow, mainly W ■ - blue sensitive particles, cyan colored, mainly red sensitive Particles and magenta colored mainly green sensitive particles can be used. to. Imaging experience according to one of the Torner claims, characterized in that the main absorption bands of the particles essentially correspond to the range of their light- sensitivity match. 009843/15 54