DE2365040A1 - METHOD OF IMAGE PRODUCTION - Google Patents

Description

DR. E. WIEGAND OIPMNG. W. NICMANN

DR. M. KOHLER DIPL-ING. C. GERNHARDT 23650 AO

MÖNCHEN HAMBURG TELEPHONE = 55547 ". 8000 M Ö N CH E N 2, TELEGRAMS: KARPATENT MATHILDENSTRASSE 12

December 28, 1973 W 41 889/73 - Ko / Yes

Fuji Photo Film Co. Ltd. Minami Ashigara-shi,
Kanagawa (Japan)

Method of image production

The invention relates to a method for producing images based on an electrophotographic process using photoconductive fine powder, in particular, the invention relates to a method of producing high contrast images using highly sensitive, fine powders which show a relatively light-colored appearance.

According to the invention there is provided a method of image formation wherein a practically uniform layer

409828/103

a charged photoconductive fine powder containing a coloring agent or a coloring agent precursor, on the conductive surface of a component with sliding Surface is formed, imagewise the component with light to reduce the electrostatic attraction between the Surface and the fine powder is irradiated at the irradiated areas, selectively the irradiated at the irradiated area. brought fine powder is removed from the surface so that an image composed of the fine powder is obtained second powder, charged with the same polarity, is spread over the image-bearing surface while the photoconductive fine powder forming the image has a sufficient electric charge that the second powder predominantly in the area where there is no photoconductive fine powder, utilizing the electrostatic repellent force adheres between the two powders, after which the color is then applied using the colorant or the colorant precursor, contained in the photoconductive fine powder is formed.

An Electrophotographic Process Using. of a photoconductive fine powder is disclosed in Japanese Patent Publication 22643/63 and British Patent Publication 990 538. In this method, a layer of charged photoconductive powder is briefly deposited on top of a conductive surface is formed and after exposure of the layer to a light image is that lying on the exposed parts photoconductive powder removed.

This procedure has been "for a long period of time." used in practice for marking structural components of large size for ships. Combinations of this procedure and an electrostatic powder coating process an extremely attractive coating process. That is, if the coating powder has the same polarity as the photoconductive one Powder is spread over the image-bearing surface, while that from the photoconductive powder is

40 9 828/1033

thawed formed image still a sufficient amount of the has an electric charge, the spread coating powder adheres predominantly on the non-image area due to the electrostatic rejection between the two powders. Thus, a coating in the form of an image can be obtained if the color of the photoconductive powder differs from that of the coating powder differs.

Unfortunately, photoconductive powders are generally lighter in color Colour. The cause is, as has been shown theoretically, that to obtain a photoconductive powder layer with high sensitivity it is necessary that the absorption coefficient the photoconductive powder layer is correspondingly low.

For example, the commercially available EPM photoner (product Fuji Photo Film Co. Ltd.) for use in the electrophotographic marking process, e.g. Currently in the Shipbuilding industry is applied in practice, only colored light pink.

The structure of the above photoconductive powder is given, for example, in Japanese Patent Publication 12385/69 i, British Patent Publications 1,181,172, 1,183,762, Japanese Patent Publication 12385 / 6S and British Patent 1,165,017, and thus consists of a photoconductive powder, which is composed of a photoconductive surface coating and a core transparent to the light which is active for the photoconductive surface coating, while British patent specification 1,181,172 does not deal directly with a photoconductive toner, but rather photoconductive compositions, which CdS and an inorganic transparent Contain pigment powder and British patents 1,183,762 and 1,165,017 describe a process for producing a photoconductive toner using a solvent which does not dissolve the transparent core, mixing the photoconductor with the core material and pulverizing

409828/1033

specify the materials.

What is even more unfavorable is the fact that despite the repellency between the photoconductive powder and the second Powder after the electrostatic spreading of the second powder over the image built up from the photoconductive powder

inevitably the second powder B, including the photoconductive one; Powder image to some extent adhered This is especially! Remarkably adheres ₉ if a large amount stess second powder. This phenomenon is particularly evident if the second powder is spread in high speed or if a large Meng © of the powder when inside & ll "a short time is spread _a It is virtually MBJaSgIiCh ₉ fully <di @ liability gweitea powder - at the pÄotoieitenden powder image to avoid »Due to this cursed adhesion & the contrast of the finished picture is reduced. ■.

In addition, this ferfeliren then looks -to prefer -if <ä ± ® information itself is important Wiü. fresm desired \ tira ₉ that the coating "© isäheitlieh practicing d © r OberflScae present * Up thickness of the coating-take in the fields of thin, *. where the photoconductive © powder is left."

His task ©. eier invention Ibestofaf in e £ aem ^; "improved

error "nods aiaf Weis. ΏΛ _{& 9} dm pSsotoleitoiide -BüßLver Aar finding is s © designed so that it is 'bright gsfört> t -is, w @ im es -'necessary" that the powder phot © l © iteni- is _# . where -the- powder is a tinting agent la Fons τοη contains an "exercise agent pre-liquid and -In a suitable treatment _{solution 8iitt03A 9} © the reaction © it E © aktionspartners üfaeTilMiTt Μίτά * iSaoh der."

. of the second powder becomes the p & dt © l0it®öde la the "colored material tuagewaadeät» - © read dyed M

than @ _S 5 ₉ fall more than 50 g

BAD ORiGiMAU

and in the molten state it must be independent of the photoconductive Material leaked around or along with the photoconductive material incorporated in the photoconductive powder or sweat it out.

The above procedures allow a clear under-. separation of the underlying image, even if the powdery one Coating is applied over the photoconductive image in a very large amount, allowing reading of the working directions for the treatment, classification code for the components and the like. Facilitated by the workforce.

Fig. 1 shows the sequence of the treatment stages according to the invention.

2 shows a schematic view of an apparatus for forming a charged photoconductive powder image, which is intended for the implementation of stage (I) of FIG. 1, wherein the reference number 1 is a component with a conductive Surface and the reference number 2 indicate the photoconductive powder.

Each stage of the process according to the invention is explained in detail below.

Fig. 1 shows the order of the stages. The invention Levels are levels (I) to (V). Stage (VI) is an optional stage.

In the step (I), the photoconductive powder 2 becomes uniform, as shown in Fig. 2, over a member 1 with a conductive one Surface spread out, for which e.g. known method according to Applied Optics Supplement on Electrophotography, Pages 124-128 (1969) and British Patent 990 538 can be applied. On this occasion it is convenient to carry out both the expansion and the charge at the same time, because usually a higher electrical potential here compared to a method of charging under Application of corona discharge or the like. Is obtained after spreading.

409828/1033

Such materials with a conductivity of less than 1 (riL / cm (10 ° il / square) can be used as components 1 such as metal plates, stainless steel plates and the like, plastic films or papers with a metallized surface and similar materials such as papers, plastics or cloths are used, which with colloidal aluminum oxide, colloidal silica and the like. treated to reduce the high resistance to less than 10 ° XL / cm (10 JTL / square). One Adhesiveness of the surface is not favorable because it makes it difficult to remove from the surface that which is attached to the area Remove photoconductive powders where the electrical potential has been reduced by exposure to light. Certain Types of conductive resins exhibit adhesiveness due to their highly hygroscopic properties. To the surface resistance to reduce such resins, it is beneficial to use a matting agent such as colloidal alumina, Silicic acid and the like to be used in combination, as indicated, for example, in British Patent 1,198,497.

The photoconductive powders 2 are those having a particle size of about 5 to 200 microns, preferably 20 to 100 microns cheap. As also disclosed in Japanese Patent Publication 12385/69 and British Patents 1,165,017, 1 181 172 and 1 83 762, it is important that they have such a structure that a sufficient amount of light can reach the inside of the photoconductive particles. This means that the apparent color of the photoconductive powder is generally relatively light.

Such structures can, for example, be powder particles, each one for the light, for which the photoconductor is sensitive, transparent core with a formed on it thin photoconductive layer, or powder particles formed by pulverizing an intimate mixture a photoconductive substance and a non-photoconductive one

9828/1033

Γ »

transparent substance.

The color reaction employed in accordance with the invention is selected taking into account such factors that. the reaction product must be able to withstand the conditions of baking the coated film, for example at temperatures of about 150 to 200PC for about 5 to 30 minutes. As the organic photoconductor, Michler's ketone, triphenylamine, leuco derivative dyes and the like are known. One might assume that these compounds could be used for the color reaction. In fact, however, they are difficult to use because of the low thermal resistance of the colored substances. Inorganic photoconductors such as ZnO and TiO ₂ , as disclosed in US Pat. No. 3,121,006, are suitable. Organic photoconductors such as organic triphenylamines, leuco dyes, and the like, as disclosed in U.S. Patent 3,141,770 can be used, but inorganic photoconductors are particularly preferred.

A single mass, which is only capable of coloring when heated, is favorable as a coloring agent and such masses can, for example, be composed of organic acid salts of silver or similar heavy metals, such as metal salts of linear carboxylic acids with about 12 to 22 carbon atoms, for example the silver, copper , iron and similar metal salts of lauric acid, myristic acid, palmitic ₉ stearic acid, arachidic acid, behenic acid and the like are obtained.. Specific examples of these salts include silver laurate, silver behenate, silver stearate, copper stearate, ferric stearate and the like. On the other hand, it is also possible to use a binary system. In this case, each component is incorporated into different photographic powders, and in use these are mixed or the components are separately incorporated for use, for example, one in the core substance and the other in the surface layer. In use, a solution

409828/1033

agent used to color generation between a binary system, e.g. crystal violet lactone and dihydroxyphenyldimethylmethane to effect.

Specific examples of suitable compounds that can be used in the present invention are, for example, a combination of a complex between hexamethylenetetramine and gallic acid and ferric stearate, a combination of 3,4-dihydroxytetraphenylmathane and ferric stearate, and the like. Processes relating to this are known in the field of heat-sensitive copying papers and are given in various literature references, for example Jaromir Kosar, Light-Sensitive Systems ^ pages 402 to 419 (1965), John Wiley & Sonsj Inc.? K. Reynolds, ₉ Report of the Progress of Applied Chemistry, Volume 51, pages 194-203 (1966) Society of Chemical Industries and other references.

The combinations of the coloring materials are selected using the criterion "that a coloration when heated to 150 to 200 ⁰ G, or in the case of film formation of the powder coating layer is selected by High Frequency & enzinduktionserhitzung according to the criterion that the mass does not degrade or coloration under such HeiEbedingungen faded. The specific examples given above were found to work under these general hot conditions

The typical structure of the piotoconductive powder consists of a transparent Harskem and a photoconductive surface layer formed on it. The coloring component is preferably incorporated in the surface layer, which helps the reaction to proceed at a faster rate and allows it to be observed from outside relieved. @ Rnmaterialien K suitable are for example copolymers of methyl methacrylate and ethyl acrylate Polymethylmethaerylatj containing up zn about 20 wt.% Ithylacrylat, polystyrene, poly (a-methyl _styrene) copolymers _f of methyl methacrylate and styrene, copolymers of styrene and acrylonitrile "

409828/1033

Epoxy resins, Eh.enoxyh.arze and the like. Such core materials having a softening point above 80 ⁰ C and are transparent to visible light are preferred.

A suitable amount of the photoconductive material and the coloring material in the range of about 5 to 50 parts by weight for every 100 parts by weight of the photoconductive material are applied.

If a uniform coating is desired, the core material of the photoconductive powder and the resin component of the powdery coating material are selected to be the same or similar to each other. Particularly preferred resins include linear polyesters, polyamides, epoxy resins, thermosetting acrylic resins and the like. Suitable linear polyesters include polyesters or copolyesters of dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, diglycolic acid, diglycolic acid and diols such as ethylene glycol, propylene glycol, neopentyl glycol, 2,2-alkyl-substituted 1,3-propanediol, hexamethylene glycol, butane-1,3-diol, diethylene glycol and the like. Examples of polyamides include polycondensates of diamines and dicarboxylic acids or ring-opening polymerization products of lactams. Suitable diamines are ethylenediamine, triethylenediamine, tetraethylenediamine, hexamethylenediamine, piperadine, p-phenylenediamine, o-phenylenediamine, m-phenylenediamine and similar materials and suitable dicarboxylic acids are those already listed above for the polyesters. Suitable lactams include dodecyllactam, E-caprolactam, α-methylcaprolactam, N-methylcaprolactam, 6-capryllactam and the like.Suitable epoxy resins are condensates of epichlorohydrin and bisphenols or polyhydric alcohols and have at least two epoxy groups (-CH-CH ₉ ) under one

conclusion of bisphenols such as 2,2-bis (4'-hydroxyphenyl) propane (Bisphenol A), 2,2-bis- (4 * -hydroxyphenyl) -pentane, 2,2-bis- (4 * -

409828/1033.

hydroxyphenyl) heptane and similar materials. They are too polyhydric alcohols listed above are suitable together with triols.

Step (II) is generally carried out using projection exposure. Although also a exposure to contact is not impossible, it is not preferred due to the limitations of the electrical properties of the original.

Step (III) is carried out in a simple manner using a gas or air stream on the coating or using a mechanical vibration performed.

An apparatus for development (stage III) conveniently operates to remove the photoconductive powder from the support Will get removed.

Stage (IV) is carried out using the procedures of

so-called electrostatic powder coating carried out as it for example Journal of Paint Technology, 44, No. 570, pages 38 to 56, (July 1972) is given. Of course For example, an overall exposure can be carried out prior to step (IV) to discharge the charge of the photoconductive powder. On the other hand, the surface can be subjected to a corona discharge to increase the potential of the photoconductive powder to enhance repellency.

If rejection is desired, polarity is of the second powder is the same as that of the photoconductive powder, while if uniform adhesion of the second powder over the entire surface by discharging the charge of the photoconductive powder is desired, the polarity of the powder can be either positive or negative.

For some uses, a small amount of potential may be left on the photoconductive powder thereby the amount of liability of the second in a cheaper vase To regulate powder.

The commercially available powdery ones are used as insulating powders Coating materials and highly insulating resin powder,

409828/1033

as described above was used. These must be clearly different in tint appearance from the colored one be photoconductive powder. In general, suitable examples of such materials are those employed using of polyethylene, an epoxy resin, a vinyl chloride resin, a polyester, nylon, cellulose acetate butyrate or the like as the main resin component and compounding the resin with a plasticizer, hardener, or similar additive, followed by Powdering were made. The generally used particle size thereof is about 30 to 300, preferably 50 to 150 microns.

The stage (V) can either be carried out simultaneously with the stage (VI) or independently of the stage (VI). For example, the step (V) can be carried out by spreading a solution of a reactive substance, i.e. through uniform spreading of an organic solvent containing an acid such as bile acid, phenol, a polyhydric phenol, Iron stearate and the like, an alkaline substance such as an amino alcohol or phenolphthalein and the like, an oxidizing agent, for example, a color developing agent for a silver halide light-sensitive material, a coupler for a ■ silver halide light-sensitive material and the like, a reducing agent, such as hydroquinone or silver behenate or the like. Contains. In addition, a connection which is connected to the in the photoconductive powder-containing material reacts to form a colored substance, also applied in this stage will.

The step (VI) is generally carried out using high frequency induction heating or similar measures. Organic solvents are not used as favorably at this stage because of the advantages of powder coating cannot be fully achieved here.

. The following preparation examples and working examples explain the invention in detail. Unless otherwise stated, all parts and percentages are based on

409828/1033

weight related.

Production example 1

Polyamide resin beads, which were produced by ring-opening polymerization of dodecyllactam and had a melting point of about 17O ³ C and an average particle size of 50 microns, were coated with a coating solution of 100 parts of photoconductive zinc oxide, 10 parts of nickel stearate, 30 parts of methylphenylpolysiloxane resin, 50 parts of toluene and 50 parts Cyclohexane mixed. 20 parts by weight of the coating solution was used per 100 parts by weight of the resin beads. Coating and drying were carried out using spray drying, and No. 1 photoconductive toner was obtained.

Production example 2

The reaction product obtained in the reaction of hexamethylenetetramine and gallic acid was used. I.e., its polyester beads, which are the reaction product of terephthalic acid, isophthalic acid, ethylene glycol and neopentyl alcohol (Acid molar ratio 50:50; alcohol molar ratio 45:55) with an Eigenyiskosxtat of 0.59 and with an average. Particle size of 70 microns, were coated with a coating solution from 100 parts of photoconductive zinc oxide, 20 parts of the above reaction product, 25 parts of vinyl acetate / Crotonic acid copolymer (crotonic acid content: 5 degrees of polymerization, about 200 ". 90V 50 parts of toluene and 100 parts of methanol combined. 23 parts by weight of the coating solution was used per 100 parts by weight of the polyester resin beads. The covering and drying was carried out using spray drying, and photoconductive toner No. 2 was obtained.

409828/1033

Production example 3

100 parts of polystyrene (degree of polymerization: 150) were mixed with 15 parts of iron stearate and mixed thoroughly in a ball mill after adding toluene. Then it was the material spray-dried and roughly spherical fine powder particles with an average particle size of 70 microns. For this purpose, a coating solution in a weight proportion of 100: 20, which was obtained by uniformly mixing 100 parts of photoconductive zinc oxide and 25 parts of methylphenylpolysiloxane resin in a solution of cyclohexane containing of 0.20 parts by weight of Eosine Y per 10 parts by weight of the zinc oxide had been produced, was added. Then the resulting mixture was applied into a hot gas stream blown by the spray process, thereby obtaining polystyrene beads with a photoconductive layer on the surface thereof, which are referred to as No. 3 photoconductive toner.

Production example 4

The same core substance as in production ^ example 3 used (iron stearate and polystyrene) were used with a coating solution from 100 parts by weight of photoconductive zinc oxide, parts of the reaction product between hexamethylenetetramine and gallic acid, 30 parts of the vinyl acetate / crotonic acid copolymer corresponding to Production Example 2, 30/1000 parts Rose Bengal and 150 parts of methanol in an amount of 25 parts by weight mixed to 100 parts by weight of the core substance. The resulting mixture was dried by placing it in a gas stream was blown by 4OPC and the formed particles became collected. As a result, there were toner particles with a thereon photoconductive coating obtained. This toner is referred to as No. 4 photoconductive toner.

409828/1033 / -

Production example 5

A styrene / methyl methacrylate copolymer (copolymerization molar ratio i 70/30; Particle size: 6 microns) would be used as the core material. A coating solution of 80 parts photoconductive zinc oxide, 20 parts titanium dioxide, 20 parts SiI-behenate, 35 parts of methylphenylpolysiloxane resin and 120 parts of cyclohexane were prepared and 25 parts of the obtained Coating solution was mixed with 100 parts of the core substance. The obtained mixture was blown in hot air using a Blown the spray gun to obtain the No. 5 photoconductive toner.

Production example 6

Polyamide resin beads having an average particle size of 50 microns as used in Preparation Example 1 were used used as core substance. 100 parts by weight of a coating solution composed of 100 parts of photoconductive zinc oxide, 15 parts of silver laurate, 18 parts of a butyl methacrylate / styrene / maleic anhydride / hydroxymethyl methacrylate quaternary copolymer (Copolymerization molar ratio: 40/50/3/7) and 120 parts. Toluene was added with 500 parts by weight of the above Core substance mixed and in hot air using a Blown spray gun. The dried fine beads were collected, and the photoconductive toner No. 6 was obtained.

Production example 7

A -Überzugslösung * of 100 parts of photoconductive zinc oxide, - '/ 1O Teileji ₄ xanharz a reaction product between hexamethylene tetramine "and gallic acid, 20 parts MethylpheriylpolysiloV, 50 parts of toluene and 150 parts of cyclohexane was manufacturers

409828/10 3 3

and made with polyamide resin beads with an average particle size of 50 microns as used in manufacturing process 1, mixed. 20 parts of the coating solution was used per 100 parts of the resin beads. After spray coating and drying, the photoconductive toner Wr. 7 received.

Production example 8

The same coating solution as in Preparation Example 1 was applied to the core substance as in Preparation Example 2, applied in a weight ratio of 100:18. After spray drying in the same manner as in the above In Examples, No. 8 photoconductive toner was obtained.

example 1 ^r

50 parts of photoconductive toner No. 1 and 50 parts of photoconductive toner No. 7 were mixed and made uniform spread over a steel plate in an amount of 100 g / m 2. After spreading, the toner turned negative Corona exposed in the dark to charge the toner layer to -350 V. Then a positive image was projection exposed thereon and then blown a gas stream so that only those lying on the image area on the steel plate Toner particles were left. Then a white powdery polyamide coating material (6-nylonj particle size about 50 to 150 microns) then in the dark to a thickness of 200 g / m using an electrostatic Spray coating process applied. On this occasion, a negative voltage was applied to the powdery coating material. Hence the strength of the powdery Coating material on the image area is much smaller than on the

409828/1033

other areas due to the rejection of the image area although a rather large amount of the powdery coating material adhered and also on the photoconductive toner image was.

The resulting assembly was ^{heated to 18O 3} C using high frequency induction heating. As a result, a polyamide film was obtained and, at the same time, a blue-black colored substance was formed on the image area in the shape of a line.

Example 2

The procedures described in Example 1 were carried out however, the execution of the coating of the powdery coating material was carried out in the light photoconductive toner was discharged, the powdery coating material adhered almost uniformly over the entire surface at. Therefore, that of the photoconductive one in this state Toner formed image difficult to distinguish.

After being subjected to high frequency induction heating the photoconductive toner darkened so much that the image area could be distinguished from the other areas.

Example 5

30 parts of kes photoconductive toner Ur. 2 was mixed with 70 parts of No. 8 photoconductive toner, and a photoconductive toner image was obtained in the same manner as in Example 1. Then, a white powdery polyester coating material composed of a copolymer of terephthalic acid and isophthalic acid in a molar ratio of 50:50 and ethylene glycol and heopentyl glycol in a molar ratio of 45:55 with an inherent viscosity of 0 * 59 was applied to the image-bearing copper plate according to the procedure given in Example 1

applied using electrostatic spray coating. The applied amount of the powdery coating material was 150 g / m 2 in the areas where there was no photoconductive There was toner. On this occasion, the powdery coating material also adhered to the toner image and was present on the photoconductive toner image in an amount of about 40 g / m 2.

After this structure had been subjected to high-frequency induction heating to about 20O ⁰ C, the photoconductive toner was colored dark and the marrow line could be distinguished.

Example 4

The procedures described in Example 3 were carried out However, the charge on the photoconductive toner image was discharged before the powdery coating material was drawn up. The powdery material was spread in an amount of 80 g / m 2. This created a colored image in obtained in the same manner as in Example 3.

Example 5

The photoconductive toner No. 3 obtained in Production Example 3 and the photoconductive toner obtained in Production Example 2 Toner No. 2 was used in the same amounts and mixed together.

Then, the mixed powder was applied to an aluminum plate while negatively charging the mixed powder using a Powder spreader applied, as described in Applied Optics, Supplement 3 »page 125, 1969, Optical Society of America, is described. The amount drawn up was 110 g / m 2.

Then a positive image was projected onto it and the Development carried out using a gas stream and obtain a toner image.

409828/1033

The aluminum plate bearing the toner image was uniformly exposed and then negative using an electrostatic one Coating process loaded.

After spreading a yellow powdery epoxy coating material (bisphenol A and epichlorohydrin condensate with an epoxy number of about 1500, which contained CdS as pigment) in an amount of about 120 g / m, the arrangement was ^{heated to about 180 °} C. using high-frequency induction heating . As a result, the image area was colored and the image was distinctive.

Example 6

A toner image was drawn on a steel plate with a zinc-containing primer of the No. 5 photoconductive toner used in Example 5 was trained. After uniform exposure, an electrostatic powder coating was applied a powdery coating material, which polymethyl methacrylate (Degree of polymerization about 900) and titanium dioxide in an amount of 20 parts per 100 parts of polymethylinethacrylate contained, upset. The coating tightness was 140 g / no.

Then, a high frequency induction heating at about 180 ⁰ C for 5 min was carried out, wherein the powder coating layer was transferred into a continuous film and the decomposition of the silver behenate was accelerated. This colored the toner image. The color thereby formed was sufficiently different to be distinguished by the powder coating film adhered to the toner image and on the toner image.

Example 7
The procedures given in Example 6 were repeated,

409828/1033

however, the photoconductive toner No. 4 obtained in Production Example 4 is used. This enabled blue-black images to be distinguished in the same way.

Example 8

The photoconductive toner No. 6 obtained in Production Example 6 and a white powdery polyamide coating material were treated in the same steps as in Example 6. The same results as in Example 6 were obtained by heating at 16D ^{3 G for 30 min.}

The invention has been described above on the basis of preferred embodiments without being limited thereto.

40S82S / 1033

Claims (6)

Claims Ί .y method of image production, thereby g e Y e nn. that a practically uniform A layer of a charged photoconductive fine powder which is a coloring agent or a coloring agent precursor contains, is formed on the conductive surface of a component with a conductive surface, this component with light is imagewise irradiated so that the electrostatic attraction between the surface and the fine powder in the irradiated Areas is reduced, the fine powder lying on the irradiated areas selectively from the surface is removed and an image consisting of the fine powder is obtained, a second one charged with the same polarity Powder is spread over the image-bearing surface, while the image-forming piiotoconductive fine powder has a sufficient electrical charge so that the second powder predominantly in the areas where there is no photoconductive fine powder is present, adheres between the two powders using the electrostatic repelling force, followed by a color using the coloring agent contained in the photoconductive fine powder or that therein Colorant precursor contained is formed. 2. Image production method. characterized that a practically uniform layer of a charged photoconductive fine powder, which contains a coloring agent or coloring agent precursor on the conductive surface of a component having conductive Surface is formed, this photoconductive fine powder is irradiated with light imagewise, so that the electro- 409828/1033 static attraction between the surface and the photoconductive fine powder is reduced on the irradiated areas, selectively that lying on the irradiated areas photoconductive fine powder is removed and one from the photoconductive fine powder built-up image is obtained, a second fine powder over the image-bearing surface is spread using an electrostatic coating process and then a paint is applied using the in the colorant containing photoconductive fine powder or the colorant precursor contained therein is formed, 3. The method according to claim 1 or 2, characterized in that the coloring agent or the Dye precursors made from a silver salt of an organic acid, a heavy metal salt of an organic acid, a Combination of a complex between hexamethylenetetramine and gallic acid with ferric stearate or the combination of 3 »4-dihydroxytetraphenylmethane and ferric stearate is used. 4. The method according to claim 1 to 3 _t, characterized _f that ZnO or TiOp is used as the photoconductive powder. 5. The method according to claim 1 to 4, characterized that a linear polyester, a polyamide or an epoxy resin is used as the powder. 6. The method according to claim 1 to 5 _f, characterized in that an organic solvent which contains an acid, an alkali or an oxidizing agent is uniformly spread on the surface to form the color. 409828/1033 Blank page