DE1497011A1 - Electrophotographic process - Google Patents

Description

The invention relates to a combined method for Reproduction of photographs and the materials used for them «The invention is, on the one hand, a method for Production of multiple prints directed from a photograph · On the other hand, it relates to a method for producing a Intermediate or original copy sheet from a photograph that can be used to produce several copies of the same »

One recently developed imaging technique is that of electrolytically durable visible images developed on suitable, highly photoconductive copy sheets after exposure to light images. In this process, which is described in US Pat. No. 3,010,883, an electrolytic developer is electro-

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lysed and in particular a metallic one or another clearly visible coating on the exposed areas of the light-sensitive surface, e.g. by electrolytic coating Reduction, Selectively Deposited «Highly photoconductive copy sheets suitable for use in the above process are suitable are described in US Pat. No. 3,010,884 « In order to improve the sensitivity of such photoconductive copy sheets, various optical ones have been used Sensitizers suggested many of the dye sensitizers however, discolor the surface of the photoconductive copy sheet and degrade the quality of that obtained therewith Bilds «It would also be desirable to have a simple effective means of making multiple copies from the own electrolytically developed copy sheet *

The invention is a simple, economical process for producing multiple copies from a radiation image

Another object is a method of using an electrolytically developed highly photoconductive one Copy sheet as an intermediate or »starting piece for the thermal production of a heat-resistant copy same ·

Another object is a reproduction method using a photoconductive copy sheet, in the visual appearance of the photoconductive copy sheet - both before and after electrolytic development -

does not significantly affect the quality of the copies made with it

Another subject is a process for the production of several copies from a photograph »

Another subject matter is a method for producing multiple copies of a radiation image by means of of a reusable photoil itable copy sheet "

When the term "thermal process" is used here, this means processes in which heat has to be applied »

The inventive method consists in that one photoconductive, electrolytically developable Copy sheet irradiated to form a drawing of different conductivity, a drawing electrolytically a vaporizable image-forming substance on the irradiated surface, which corresponds to the drawing of different conductivity, this surface of the Lays copy sheet on a receiving surface and heats the copy sheet to allow the selective vapor transfer of the vaporizable image-forming substance to the receiving surface and the creation of a visible image that the Drawing different conductivity corresponds to effect on the recording material «According to one embodiment, the image-reflecting substance is applied as vapor to a Transferring material (usually in the form of a sheet) containing a color-producing reactant.

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MIt, the vaporized image-forming substance and the color-producing reactant on the recording material with the formation of clearly visible parts of the image react «With a different Duroheading form, with the the vaporized imaging material itself strongly colored no further reactant is required on the recording material, and the color of the recording sheet forms a visible contrast to the image-forming substance condensed on it. "

Suitable for implementing the method according to the invention strongly photoconductive copy sheets are z »B _a in US-Patentβohrift 3,010,884 described and generally consist of a highly photoconductive layer that certain substances, such as photoconductive zinc oxide photoconductive indium oxide, etc. _0, conductive on a continuous electrically Substrate, such as aluminum foil, contain optical sensitizers, z «S» acridine orange, can be incorporated into the photoconductive layer to improve the spectral sensitivity «Since the color of the copy sheet does not necessarily affect the quality of the thermally produced copies, the amount of sensitizer in the photoconductive layer strongly ver _r changes UEU obtain the best results. The photoconductive layer can be coated with a water-permeable layer, for example with a film-forming silica

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Umbildende silicas are usually able to form a "stable aqueous colloidal sol with a particle size between about 1 and 100 μm in diameter, preferably between about 10 and 50 μm in diameter, and they can be prepared according to the US Pat. No. 2,244,325 "Further such electrolytically developable photoconductive copy sheets with glossy _p water-permeable, coherent and relatively transparent silica films on the photoconductive layer are described in US patent application 140 032 of September 2, 1961"

After irradiating the photoconductive copy sheets to a source of activating radiation z _e B "actinic radiation, such as visible light,! X-rays, electron or proton beams, etc. © _ff is generated a drawing of different electrical conductivity in the photoconductive layer by the activating radiation corresponds to ₉ and used to selectively produce a drawing from a vaporizable image-forming material on the conductive points by electrolytic means described * with the indication "vaporizable image-producing substance"

is meant here a substance that easily dissolves at temperature

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Temperatures above room temperature and below 300 ⁰ C, preferably between about 60 and 250 ⁰ G, can evaporate and the color change either by chemical reaction with other compounds or - if it is strongly colored itself - by condensation of the vapor on a surface without chemical reaction can cause _o Regardless of whether the ₉ vaporizable image-forming substance reacts now or not, it is essential that they are not evaporated under normal room and storage conditions, and under these conditions is usually determined "

Various methods can be used to draw different conductivity levels on the exposed To convert copy sheet into a corresponding drawing made of vaporizable imaging substance * The conversion but takes place in each case electrolytically or electrophoretically. For the sake of simplicity, this is generally done here We speak of "electrolysis", which means that it also includes the electrophoresis of charged particles other than ions · When performing the vaporizable image-forming substance can be selectively by electrolysis (if necessary with modification of the same) on the copy sheet surface deposited, or a thin film of vaporizable imaging substance can be applied evenly to the Kopierblattoberfläohe applied and electrolytically to the Image areas are modified in such a way that its evaporability and or * or its toild-producing properties

The former is referred to as "electrolytic deposition ^{11 and} the latter as" electrolytic modification ", although both processes can of course also be used at the same time.

Electrolytic deposition occurs through the deposition of the normally stable vaporizable image-forming substance directly from the solution or suspension. If the electrolytic bath contains the vaporizable image-forming substance or its electrolytic precursor in solution, the copy sheet is connected either as an anode or as a cathode, depending on the charge of the ion "If the electrolytic bath the vaporizable image-forming substance or its electrolytic precursor contains in suspension ,, is preferably a suitable charged carrier," B _e colloidal aluminum hydroxide, used surface to a hike to the copy sheet to effect where it is deposited "in a In such deposition processes, the vaporizable image-forming deposit can consist of a reactive, vaporizable, image-forming compound which, upon vapor transfer from the copy sheet to the recording material, becomes a visible component with another reactant thereon Image reacts. Such reactive, vaporizable, image-forming compounds are, for B # ₀ oxidation and reduction means, and the respective reactant is then a compound or its color value in the oxidation reduction changes * "A preferred group of

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Reactive compounds capable of digestible images are produced from quaternary cyclic bases. Examples of brewable quaternary cyolisohe bases are 1-ethylohinolinium iodide, 1-ethylehinaldinium;) odid _f 1-ethylpyridinium bromide, 1-ethyl ~ 2,6-dimethylquinolinium;) odide, 1-butylpyridinium bromide, i-ethyl-2 methylpyridinium bromide, 1-ethyl-4-methylpyridinium bromide, etc., which are electrolytically deposited on the cathode from an aqueous medium to form the corresponding organic reducing agent can be reduced to amines, aromatic hydroxylamines, etc. ««. Vaporizable oxidizing agents, e.g. the oxidation product of hydroquinone, pyrocatechol, tetraohlorhydroohinone, tetrabromohydroquinone, aminophenol or oxidizing agents such as N-chlorosulfonamides, etc., can also be electrolytically separated if the copy sheet is held as an anode, usually from the correspondingly charged electrolyte Particle contains Reducible reactants such as silver behenate, etc. evenly distributed on the recording sheet can be reduced by an evaporated reducing agent, causing a color change on the recording material. On the other hand, the reducible reactants on the recording sheet can themselves be intensely colored and on contact with a vaporized organic

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nisohen reducing agent j their P arbint ens it ät lose or change, such as "B _e reducible dyes such as methylene blue, crystal violet and malachite green ,, When the receiving sheet contains a relatively colorless compound which forms a colored complex, the vaporizable imaging Absoheidungen can appropriate complexing agent containing, z _o B "catechol (together with iron compounds, a complex), the colored complex is formed on the Aufnahmeüatt in the vapor transfer ₀

When the vaporizable image-forming substance itself is intensely colored, it can - as already mentioned - be transferred directly to the receiving surface in vapor form where, when they condense without any further chemical conversion, they form a visible drawing that corresponds to the original Picture corresponds. The recording sheet therefore no longer needs to contain a reactant. Both water-soluble as well as water-insoluble dyes can be deposited, the latter preferably from a colloidal suspension a suspension of positively charged particles "

Electrolytic modification can also be applied to create a selective imagewise coating of vaporizable to generate imaging substance on the copy sheet surface. Instead of the vaporizable imaging substance The copy sheet can also be deposited electrolytically evenly covered with a thin mim made of a substance are then carried out through the electrolytic implementation

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modified so that their vaporizability - and / or * or their image-forming properties are changed «. This modification can be done by the verdampfbarβ image forming substance as described in the more conductive areas of the copying sheet surface below selectively electrolytically destroyed electrolytically masked or rendered immobile electrolytically _o

The mechanism of the electrolytic destruction of a vaporizable image-forming substance can consist in that a vaporized bares reducing agent which is uniform on or distributed throughout the copy sheet surface is oxidized electrolytically "Such reducing agents are pyrogallol, pyrocatechol, methyl gallate., Naphthols, 4-methoxynaphthol, etc. _o , which are anodically oxidized in the more conductive areas of the copying sheet surface "Collapsible reactants ZEBE silver behenate, and so _o that are contained in the receiver sheet are then reduced when they come with the vaporized _p non-oxidized reducing agent into contact with a visible This vaporizable reducing agent can also be cathodically electrolyzed in a medium that produces a relatively high pH value at the areas affected by light, e.g. aqueous bath containing soluble magnesium salts. When exposed to air in such an alkaline environment

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the evaporable reducing agents (ζ «Β · 4 ~ methoxynaphthol) slightly in the more conductive areas oxidized, the non-oxidized reducing agent only at the background points for the vapor transmission to the Recording sheet and implementation with silver behenate or another suitable substance, which changes its color value on reduction, remains available *

Electrolytic masking utilizes a photoconductive copy sheet having on or just below its surface a uniform layer of a vaporizable imaging substance and selectively electrodeposing a mask or coating such that this imaging compound covers the more conductive areas; ^ which is fixed «The masking usually consists of a high molecular weight, ζ _β Β · polymeric substance, which is deposited in two ways from a latex and which forms a layer which is relatively impermeable to the vapor« The latex can be deposited either cathodically or anodically, depending according to the charge of the particles. Examples of suitable insulating masking substances are the organic chelates or coordination compounds and amine derivatives, such as amine salts or quaternary compounds, including the Werner ¹ see chromium complexes of fatty acids (e.g. Quilon chromium complex, a product of EI ₀ du Pont de Nemours and Co ·), various fatty amine derivatives (e.g., Armeens and Arquads from Armor Industrial Chemical Co.), amine-containing resins (e.g.

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Versamid resins of General Mills, Inc ·), condensation products of polymerized unsaturated fatty acids (e.g., "B" Dllinolsäure) with aliphatic amines (e.g. ₀ B. ethylenediamine), polyethylene, polytetrafluoroethylene, polytrifluorochloroethylene, synthetic rubbers, polyvinyl acetate, polystyrene, butadiene-styrene -Misohpolymers, butadiene-aoryl acid copolymers, natural rubber, polyvinylidene chloride, etc. «· After the deposition of sufficient masking material to inhibit the vapor transmission of the image-generating substance at the image areas, the non-masked image-generating

an substance, the background areas more easily in vapor form

transfer the admission sheet "

Also the electrolytic immobility is a Process for producing an imagewise coating of evaporable imaging reactant on the copy sheet surface "In contrast to processes in which the image-forming properties of the vaporizable substance are changed, this process generally changes the vaporizability of the image-forming substance Copy sheet surface can be coated with a vaporizable imaging substance that is complex or chelated with less vaporizability, e.g. by chelating or Complex formation with a phenolic reducing agent which is uniformly distributed over the surface of the copy sheet. coated by cathodic electrolysis of a metal ion which forms a complex with the phenolic reducing agent «

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If z ₀ B ₀ a. Copy sheet is evenly coated with catechol and irradiated with a light image, a colored complex is formed by cathodic electrolysis with a bath containing iron (II) or iron (III) ions at the more conductive (and more alkaline) areas of the copy sheet surface * This complex has a much lower volatility than pyrocatechol! If heat is applied evenly to the copy sheet, only the free catechol at the background areas is transferred as vapor to the recording sheet, where it reduces or exceeds a substance, e.g. forms a complex with another substance to produce a visible image »

In the electrolytic modifying method, the vaporizable image forming substance can be uniformly in a thin film over the photoconductive surface of the copy sheet after exposure to the light image and prior to the electrolysis be distributed _o If the film ams vaporizable image forming substance is relatively transparent to the activating radiation, with the the image of different conductivity is produced on the copy sheet, it can of course already be present on the photoconductive surface before exposure * .. It has been found that extremely small amounts of the vaporizable image-forming substance, evenly distributed over the copy sheet surface, for the thermal production of several copies with the copy sheet are sufficient in the specified manner «, as already

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mentioned, the vaporizable imaging substance can also be in a coating on or near the surface of the photoconductive copy sheet must be included *

Is as recording surfaces tissue paper may be plastic, metal foils or plates etc. _o used "Porous flexible sheets are sometimes advantageous, when an image-forming reactants either the receiver sheet or the surface incorporating the same have been * Transparent recording sheets can be used for the preparation of transparencies, with which one can project light images ,, This is often important if the image is to be enlarged, for example "for a microfilm"

Both positive and negative prints can be produced on the receiving sheets "If z _o B _e the recording sheet includes a colored reactant which is rendered colorless by reaction with a reducing agent which has been evaporated from the more conductive parts of the copying sheet, a positive of the original radiation image, if, conversely, the reactant is reduced to a more intensely colored product, a negative pressure can be obtained. ^ _ are converted _o Silver behenate and tetrazolium compounds are reactants, which on contact with a

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steamed reducing agents are colored more intensely »

After exposure of the photoconductive copy sheet to or at the same time as the radiation image, the sheet is developed electrolytically, with a differential deposition of vaporizable imaging substance on the photoconductive surface using one of the electrolytic deposition or modification processes described above When a relatively translucent, electrically conductive surface coating is applied to the photoconductive layer (ζ, β metal, etc.), as described in the US patent application described 115 290 of 29 may 1961 * _p this Rektifikationshemmung can significantly reduced, and facilitate the development of electrolytic anodischc photoconductive copy sheet *

The electrolytic development compartment becomes the copy sheet brought into close proximity, preferably in mechanical contact, with a recording sheet «If the copy sheet something about the evaporation point of the vaporizable imaging agent Substance is heated, expediently by passing the copy sheet and the receiving sheet on it through heated Rollers, an ironing device or a commercially available thermographic copier, the heat being preferred

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act on the back of the photoconductive copy sheet is left, the image-forming substance evaporates and is transferred as vapor into the adjacent receiving sheet. This vapor transmission can be with one or more Record sheets for making multiple copies the photoconductive interleaf copy sheet are repeated until the vaporizable substance is exhausted »Upon exposure heat on the copy sheet also erases the drawing of different conductivity on the same, so that in some cases the copy sheet after the vaporizable imaging substance on its surface has been consumed can be reused «

A device suitable for heating the copy sheet can expediently consist of a linear source, which has a tubular piston with a linear thread and mounted at the focus of a mirror assembly as described in U.S. Patent 2,740,895 is "Another suitable form of device is described in US Pat. No. 2,891,165" A heated plate can also be used «The following examples illustrate the invention ·

example 1

This example describes the cathodic electro « lytic deposition of an organic reducing agent "

A photoconductive copy sheet that is highly photoconductive Layer of zinc oxide and a butadiene-styrene

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Mixed polymer (molar ratio 30:70) in a ratio of pigment to binder of about 4: 1 on an aluminum foil as a base, was irradiated with a visible light image a sponge developing roller made (as the anode) through the surface and applying a DC voltage of 40 V * the sponge developing roller contained a 5 follow aqueous solution of 1-Athylpyridiniumbromidp the thus developed copy sheet was then contained against a receiving sheet of paper Down "the silver behenate, and between metal plates about ^ 1 3ekun.de heated to 120 ⁰ C "Hot rollers or another device for evenly heating the copy sheet over a certain period of time can also be used". A brown-black negative image is developed on the recording sheet. "This measure can be used to produce further copies i It can be repeated in the same way and allows the production of several enlarged prints from a microfilm. The finished prints can be read directly on an opaque recording material if the original visible light image is a mirror image of the desired print, _{or the like}

Example 2

This example describes the production of a transparency by means of cathodic electrolytic deposition of an organic reducing agent _β

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A transparent recording sheet was prepared by using a polyethylene terephthalate film with an alcoholic solution of triphenyltetrazolium and a Butyralpolyvinylkunststoff was coated _o! Compartment to the procedure given in Example 1 was obtained a negative overlay image on the receiver sheet after a heat treatment at 100 ⁰ C "

Example 3

This example describes the production of a slide or an opaque print by electrodeposition of an organic reducing agent *

A receiver sheet previously coated with colloidal silica was coated with a 3-point solution of crystal violet in ethyl alcohol to give a blue-colored receiver sheet. A zinc oxide photoconductive copy sheet was then exposed to a visible light image and followed electrolytically with a 5 . Solution covered with 1-Ä'thylpyridiniumjodid as described in Example 1, "The exposed copy sheet was then placed on the blue-colored recording sheet and briefly heated to 120 ⁰ C" A positive white-on-blue copy was obtained ₉ by the crystal violet in the areas corresponding to the exposed areas of the photoconductive copy sheet was reduced to the leuco form »

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Example 4-

This example describes the electrolytic deposition of a vaporizable dye «

200 g of water and 6 g of colloidal aluminum oxide hydrate (AlOOH) were mixed in a mixer for 5 minutes. Then 3 g of Du Pont Oil Yellow N, a water-insoluble dye (color index 11 020) were added and dispersed by further mixing for 10 minutes. A photoconductive zinc oxide copy sheet of the type described in example 1 was exposed to a visible light image and electrolytically developed in the above dispersion "wherein the copy sheet has been connected as the cathode _o is less than 5 seconds at 40 V DC voltage is colloidal aluminum hydroxide eliminated (the particles of which carry a positive charge), and The copy sheet was then removed from the electrolysis bath, the colored surface was placed on a receiving sheet of paper and the rear side of the copy sheet was heated evenly to about 250 ° C Image that corresponds to the original photographic image d, received on the recording sheet "

Example 5

This example describes the electrodeposition of a vaporizable coelating agent. 200 g water and 6 g colloidal aluminum hydroxide

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(AlOOH) were mixed homogeneously for 5 minutes. Then 3 g of dimethylglyoxime, a water-insoluble complexing agent, were added and dispersed by further homogeneous mixing for 10 minutes The above dispersion developed, with the copy sheet being connected as the cathode «compartment for less than 5 seconds at 40 V DC, colloidal aluminum hydroxide and dimethylglyoxime had deposited on the areas of the photoconductive surface struck by light» The copy sheet was then removed from the bath and replaced with its photoconductive surface placed on a recording sheet having a Mckelseife contained ".The back of the copy sheet has been short time uniformly to 25O ⁰ G heated" After separation of the sheets containing the recording sheet, a red image that has been formed by the ETickeldimethylglyoximkomplex "10 copies wu rden produced with this copy sheet and other identical recording sheets ^ by heating them in the specified manner "

Example 6

This example describes the process of electrolytic Destruction in which an organic vaporizable reducing agent is selective in a high pH environment is oxidized "

A photoconductive copy sheet with a coating of Ö09823 / 091I

Zinc oxide and a binder made from a butadiene-styrene copolymer (weight ratio 4: 1) on an aluminum foil as a base was coated with a thin film of 4-methoxynaphthol and lightly polished _{9 to} obtain a thin, coherent coating. The copy sheet was JHVtTtLe in the dark The aluminum foil was connected as the cathode ₉ and a porous plastic roller (Poreion), which contained a 5% aqueous solution of oesium nitrate ₉ , was slowly passed over the surface V DC voltage was applied _o After the electrolytic development, the 4-methoxynaphthol was oxidized to the more conductive bodies by the increased alkalinity in the air "the copy sheet was then placed on a recording sheet of paper containing silver behenate, and heated to 120 G wherein check a visible blue-black positive image on the receiving sheet formed ₀ In der several copies could be made in the same way «

Other suitable electrolytes are ionizable salts of barium, magnesium, calcium, potassium and sodium "Hydroquinone works in the same way ₉ when it is used in place of 4-methoxynaphthol",

Example 7

This example describes the electrolytic immobilization by means of ohelate formation « A photoconductive copier adapted in the dark

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leaf j as described in Example 1 was coated with catechol and exposed to a light image and cathodically electrolyzed in the same manner "The porous roll contained a 5 $ aqueous solution of iron II ammoniumsulfato The voltage was 20 Y * The ferrous ion reacts with the catechol in the exposed areas, forming a colored complex with a lower volatility than catechol "If the copy sheet to a recording sheet electrolytically developed, the silver behenate was contained, added and heated to 120 ⁰ C, was applied to Obtain a positive visible image on the receiving sheet, the silver behenate being reduced by evaporated catechol o

In the same way, a dithiooxamide can be electrolytically be converted into a complex with winding by using an aqueous nickel salt solution as the electrolyte and the non-complexed dithiooxamide is transferred as vapor to a receiving sheet, which is a complexing Contains nickel salt, whereby a positive »pressure is obtainedo

Example 8

This example describes the electrolytic destruction by anodic electrolytic oxidation of a vaporizable reducing agent _{or the like}

A zinc oxide photoconductive copy sheet, as shown in U.S. Pat Example 1 is described, was coated on the zinc oxide surface evenly by vapor deposition with aluminum, wherein

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the aluminum layer has a 30 follow transmittance of visible light from a tungsten light source had "The coated surface was then removed by rubbing with 4-methoxy-1-naphthol coated and exposing the sheet obtained to a light image" The electrically conductive substrate of the copy sheet was connected as the anode and the electrolytic development was carried out for 3 seconds at 40 V DC with a 5- follow aqueous solution of sodium acetate as an electrolysis bath. The 4-methoxy-1-naphthol was selectively oxidized at the exposed and therefore better conductive areas of the copy sheet surface Receiving sheet made of paper containing silver behenate, brought into contact and ^{heated to 120 °} C., a positive image was obtained on the receiving sheet «

The same results were achieved when photoconductive copy sheets were used which had a coating of carbon black in a binder made from butadiene-styrene misoh polymer (10-20 ° permeability for visible light) instead of vapor-deposited aluminum. "Semiconductors coated as vapor, z" B "InSb of type P, and other substances with relatively low lateral and relatively high vertical electrical conductivity can also serve as topcoats for the photoconductive layer, provided that these layers allow sufficient radiant energy to pass through to activate the photoconductive layer below"

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Belspiel 9

This example describes the electrolytic Masking "

A photoconductive zinc oxide copy sheet as described in Example 1 was coated on the surface with Du Pont Oil Yellow N (color index 11 020). The copy sheet was then exposed to a visible light image, "it produced a corresponding conductive drawing The electroconductive support of the Eopierblatts was connected as the anode and the electrolytic development for 3 seconds at 45 volts DC with a 3 follow aqueous dispersion of colloidal aluminum hydroxide (Α100Ή ) as an electrolysis bath, carried out. The positively charged aluminum hydroxide particles were selectively deposited on the more conductive areas of the copy sheet surface and. formed a covering overcoat over the yellow dye. This developed sheet was then placed on a normal sheet of paper and ^{heated to 250 °} C., forming a positive dye image on the paper surface. "

Example 10

This example describes the electrolytic decomposition disruption caused by selective anodic oxidation of a reducing agent.

An aluminum vapor coated photoconductive copy sheet as described in Example 8 was prepared on the aluminum surface with a 2 # solution of

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Hydroquinone rubbed in methanol "After the exposure with an Itohtbild, the electrically conductive support of the copier sheet was switched as an anode, and this was electrolytically developed for 3 seconds at 40 V DC with a 5 # aqueous sodium acetate solution as an electrolytic bath." Here, the hydroquinone was selectively applied to the exposed areas oxidized to ohinone. When this sheet is placed on a receiving sheet of paper containing silver behenate and ^{heated to about 120 °} O, the vaporized hydroquinone is transferred to the receiving sheet and the silver salt is reduced to free silver so that a positive pressure is obtained contains red-colored 1,3,5-triphenylformazan, the evaporated ohinone oxidizes and decolorizes the red formazan to a negative pressure. If the leukoform of malachite green (color index 4200) is contained in the recording sheet, it is colored green by the evaporated ghinone Form oxidizes with the formation of a positive pressure »

The copy sheet can also be coated with ohinone and cathodically reduced to hydroquinone at the exposed areas will"

Example 11

This example describes the electrolytic modification by cathodic deposition of an oxidizing agent and the resulting oxidation of a vaporizable reducing agent " _:

A zinc oxide photoconductive copy sheet, as shown in U.S. Pat Example 1 described, was carried out with a visible light

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Bild irradiated and developed electrolytically with an aqueous solution containing 3% by weight of K ₂ Or ₃ O ₇ and 3% by weight of NiCl ₂ . The nickel chloride can be replaced by CoOl ₂ or MnOl ₂ , which also form relatively water-insoluble metal chromates. The electrically conductive backing · de »Kopierblattee (about 3 seconds at 40 V direct current) connected in the electrolysis as the cathode * During dtr kathodisohen electrolysis were more alkaline the more conductive locations of the Kopierblattoberfläohe were dropped at these locations selectively insoluble Nickelchromatniedersohläge from . Naoh electrolysis the copy sheet surface was lightly with 4-methoxynaphthol rubbed "At the places where the Ifiokelchromat failed, the 4-methoxynaphthol was oxidized" If the copy sheet to a receiver sheet comprising silver contained, set and several seconds to about 120 ⁰ O was heated, the non-oxidized 4-methoxynaphthol was transferred to the background areas as vapor on the receiving sheet and reduced the silver behenate with the formation of a positive pressure to free silver »

Other vaporizable reducing agents such as hydroquinone * can be used with equal success in place of 4-Methoxynaphthols "If hydroquinone is used can thus serve the oxidation product, Chinon, and to implement a recording sheet for an oxidizable substance, _e Bo Malachite Green ( Color index 4200), contains »

'- Example 12
This example describes the electrolytic modification

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tion of a reducing agent through cathodic deposition and its reaction with a vaporizable complexing agent «

A photoconductive Zinkoxydkopierblatt, as described in Example 1 _s was provided by immersing in the following aqueous colloidal sol of a film-forming silica containing a transferable as a vapor Eeaktionsteilnehmer, with a coating "

50 g desalinated acidic silica sol (34 $ solid substance in

Water j particle size 16-22 mp., Nalcoag 1034A) 30 g water
20 g of isopropyl alcohol
2 g dithiooxamide «

After the coated copy sheet was allowed to dry for several hours under normal room conditions, it was exposed to a light image and then electrolyzed in a 5% aqueous solution of ethylpyridinium bromide for 1 to 3 seconds at 40 VDC placed on a recording sheet of paper which contained nickel stearate ₉ and heated to about 120 ^° C. for several seconds * A blue positive image was obtained on the recording sheet in that the dithiooxamide evaporated on the background areas of the copy sheet reacted with the niokel stearate to form a blue niocel complex no dithiooxamide was transferred to the exposed areas of the copy sheet *

Various other Durohführungformen of the invention Procedures are possible within the scope of the invention *

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Claims (1)

Patent claims »! 4 97011 1 »" \ Image reproduction process, characterized in that that you can use a photoconductive, electrolytically developable copy sheet for forming a drawing of different Conductivity irradiated on the same with activating radiation, electrolytically produces a drawing from a vaporizable image-forming substance on the irradiated surface, whereby the vaporizability and the imaging properties of this substance in accordance with the drawing of different conductivity change the surface of the copy sheet, which contains the vaporizable imaging substance, immediately adjacent to one Recording surface brings, which is able to change its color on contact with the vaporizable image-generating substance, and the copy sheet is heated sufficiently to effect the vapor transfer of the vaporizable imaging substance to the To effect recording surface, with a visual image on the recording surface is caused, that of the drawing, different conductivity corresponds to » 2 «Image reproduction method according to claim 1, characterized in that the vaporizable image-generating Substance is colored and the visible image on the recording surface is produced by condensation of the vaporizable image-forming substance on the same » • ■ # -, "ί f ■ * '■''■
9 3 «Image reproduction process according to. Claim ί, characterized in that the receiving surface contains a substance which reacts chemically with the vaporizable image-generating substance and in this implementation its Color changes » 4 »Image reproduction process, characterized in that a photoconductive, electrolytically developable Copy sheet irradiated with activating radiation to form a drawing of different conductivity on the same, electrolytically a vaporizable imaging agent Substance selectively at the more conductive parts of the copy sheet separates, brings the electrolytically developed copy sheet immediately next to a receiving surface that is able to change its color upon contact with the vaporizable image-forming substance, and the copy sheet is sufficient heated to the vapor transfer of the vaporizable imaging To effect substance on the receiving surface, whereby a visible image is produced on the receiving surface that corresponds to the drawing of different conductivity » 5 # method according to claim 4, characterized in that that the vaporizable image-forming substance is an organic one Dye is. 6 * Method according to claim 4, characterized in that that the admission interface contains a reaction participant, BAD ORiQtNAt 909823/0918; ~ 3O ~ the substance that forms an image anyway with the vaporizer bar The product reacts which is more intensely colored than the reactant " 7 »The method according to claim 4, characterized in that that the receiving surface contains silver behenate and the vaporizable imaging substance a reducing agent for silver behenate is. 8 »Method according to claim 4, characterized in that that the recording surface has a colored reactant which reacts with the vaporizable image-forming substance to form a product that is less intense is colored as the reactant 9 «Method according to claim 4, characterized in that that the recording surface contains crystal violet and the vaporizable imaging substance is a reactant for crystal violet " 10 »Method according to claim 4» marked by ", that the recording whether he flat is the surface 'of a transparent plastic sheet, 11 »Method according to claim 4, characterized in that the receiving surface is the surface of a sheet of paper. .., ._:, .. ■ ■ -. ■ - ':. = ■ ■ ■ - ■■■■■ "- ■■■ - ■ - - 12. Method of reproducing an image, thereby characterized in that one is a photoconductive, electrolytic 9 0 9823/0918 Developable copy sheet with activating radiation irradiated, which evenly distributes a vaporizable image-forming substance in the effort of its surface contains, wherein a drawing of different conductivity is formed on the copy sheet, electrolytically the Vaporizability and the image-forming properties of the substance selectively at the more conductive points of the irradiated copy sheet modified, then brings the copy sheet immediately next to a receiving surface that their Can change color on contact with the vaporizable image-forming substance, and the copy sheet is uniform and heated sufficiently to allow vapor transmission of the vaporizable to effect imaging substance on the receiving surface, leaving a visible image on the receiving surface is caused, which corresponds to the drawing of different conductivity » 13 · The method according to claim 12, characterized in that the vaporizable image-forming substance to the stronger conductive areas of the photoconductive copy sheet is transferred as vapor to the receiving surface, the visible Image is generated on this * 14. The method according to claim 12, characterized in that the evaporable image-forming substance on the less conductive areas of the photoconductive copy sheet is transferred as vapor to the receiving surface, wherein the visible image is generated on this « ■ 909823/0918 8AD0R.0.NM. 15 »Method according to claim 12, characterized in that that the vaporizable imaging substance is an organic reducing agent. 16p. Method according to claim 12, characterized in, that the vaporizable image-forming substance is an organic one Oxidizer is " 17 * The method according to claim 12, characterized in that the vaporizability and the image-forming properties of the vaporizable image-forming substance are electrolytically destroyed at the more conductive points of the irradiated copy sheet _o 18 »The method according to claim 12, characterized in that the receiving surface contains a reactant, that with the vaporizable imaging substance reacts to form a product that is more strongly colored than the reactant « 19o method according to claim 12, characterized in, that the receiving surface contains Sijtflberbehenat and the vaporizable imaging substance is a reducing agent for silver behenate " 20 «The method according to claim 12, characterized in that that the receiving surface has a colored reactant contains that with the vaporizable image-forming substance reacts to a product that is less intensively 909823/0918 ORIGINAL colors is as the respondent " _21c method according to claim 12, characterized in that the receiving surface is the surface of a transparent plastic sheet « 22o method according to claim 12, characterized in, that the receiving surface is the surface of a sheet of paper " 23o method according to claim 12, characterized in, that the vaporizability and the image-forming properties the vaporizable image-forming substance olektrolytisoh modified by throwing a masking substance electrolytically is deposited on it " 24o method according to claim 12, characterized in, that the vaporizability and the image-forming properties of the vaporizable image-forming substance are electrolytic can be modified by electrodeposing a polymeric masking substance thereon 25 * The method according to claim 12, characterized in that that vaporizability and the imaging properties the vaporizable image-forming substance has been electrolytically modified by complex formation " 90 9 823/09 18