EP0608728B1 - Cleansing solution for toner images of electrophotographic lithographic printing plates - Google Patents

Cleansing solution for toner images of electrophotographic lithographic printing plates Download PDF

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Publication number
EP0608728B1
EP0608728B1 EP19940100534 EP94100534A EP0608728B1 EP 0608728 B1 EP0608728 B1 EP 0608728B1 EP 19940100534 EP19940100534 EP 19940100534 EP 94100534 A EP94100534 A EP 94100534A EP 0608728 B1 EP0608728 B1 EP 0608728B1
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Prior art keywords
toner images
solution
solution according
pbw
toner
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EP19940100534
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German (de)
French (fr)
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EP0608728A1 (en
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Ernst-August Dr. Hackmann
Ulrich Widmer
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Agfa Gevaert AG
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Agfa Gevaert AG
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G13/00—Electrographic processes using a charge pattern
    • G03G13/26—Electrographic processes using a charge pattern for the production of printing plates for non-xerographic printing processes
    • G03G13/28—Planographic printing plates

Definitions

  • the invention relates to a solution for washing out toner images of planographic printing forms produced by electrophotography. It also relates to the use of this solution for washing out toner images from such printing forms.
  • a recording material which has a conductive substrate and a photoconductive layer is electrostatically charged and imagewise exposed, the charge image obtained is developed with an electrophotographic developer to form the toner image and the layer from the non-image-free areas not covered with toner dissolved away with a stripping liquid.
  • the hydrophilic substrate is exposed at the non-image areas, so that the planographic printing plate thus obtained can be used directly for printing.
  • the quality of the printed image can be adversely affected by the toner layer lying on the remaining image points of the photoconductor layer. In such cases, therefore, it has been started to remove the toner image by washing out with a hydrocarbon solvent which does not attack the photoconductor layer itself.
  • EP-A 27 614 and DE-A 30 05 695 Suitable solvents and their use for the purpose described are described, for example, in EP-A 27 614 and DE-A 30 05 695.
  • EP-A 246 538 describes the use of an emulsion of an aqueous and a hydrocarbon phase for the same purpose. All of these wash-out solutions contain aromatic or naphthenic hydrocarbons, which smell very unpleasant even when used correctly and whose environmentally friendly disposal is problematic and time-consuming.
  • the object of the invention was to propose a washout solution for toner images of electrophotographically produced planographic printing plates which is suitable for selectively detaching the toner image from the photoconductor layer within a short time and which can be disposed of after use without any problems.
  • a wash-out solution for toner images of planographic printing forms produced by electrophotography which contains 90 to 98, preferably 93 to 97,% by weight of at least one (C 1 -C 5 ) alkyl ester of an aliphatic (C 8 -C 22 ) monocarboxylic acid and 2 to 10, preferably 3 to 7, wt .-% of an N-alkyllactam, based on the sum of both components.
  • the ester component of the solution must be liquid and should contain practically no separable solid components. At least part of the ester is preferably derived from an unsaturated, optionally also partially hydrogenated aliphatic monocarboxylic acid.
  • the esters can be prepared in a known manner by esterification of a suitable monocarboxylic acid with an alkanol having 1 to 5 carbon atoms or by transesterification from a suitable naturally occurring fat or oil with the corresponding alkanol. Suitable esters are described in WO 90/03 419, to which reference is made.
  • the solution according to the invention contains an N-alkyllactam as a further necessary component.
  • This compound has an alkyl group with about 1 to 5, preferably 1 to 3, carbon atoms.
  • the lactam may preferably contain 5 or 6 ring members and is generally saturated. Examples of suitable lactams are N-methyl-, N-ethyl- and N-isopropyl-pyrrolidone, N-methyl- and N-ethyl-2-piperidone.
  • the N-alkyl-pyrrolidones, especially the N-methyl-pyrrolidone are particularly preferred because of their general availability.
  • the washout solution according to the invention can furthermore contain conventional additives, such as corrosion inhibitors or surface-active agents, in smaller amounts.
  • conventional additives such as corrosion inhibitors or surface-active agents
  • Corresponding additives are described in WO 90/03 419.
  • surfactants When surfactants are added, the amount thereof is generally in the range of 0.5 to 2% by weight based on the total amount of the aliphatic alkyl ester and N-alkyl lactam.
  • the washout solution according to the invention brings about a rapid detachment of the toner layer from the image areas of the photoconductor layer of the concrete-coated and image-delaminated printing plate without the image areas of the photoconductor layer being attacked to any appreciable extent. It works just as well as the high-boiling, especially aromatic, hydrocarbons used for the same purpose.
  • the solution according to the invention differs from these substances by its easy biodegradability and its non-toxicity. It can be handled without special precautionary measures, because on the one hand its vapor pressure is very low and on the other hand the vapors emanating from it are not harmful to health.
  • washout solution according to the invention can be applied in the usual way either manually by wiping the plate surface or in a suitable washout device.
  • the printing plates to be processed with the washout solution according to the invention are known. They generally consist of a conductive substrate, preferably an aluminum plate, and a photoconductor layer. This preferably contains an organic photoconductor, a polymeric binder which is preferably water-insoluble and soluble in aqueous-alkaline solutions and, if appropriate, other conventional constituents. Suitable electrophotographic materials are described in EP-A 31 481, 34 317 and 246 538.
  • the materials are processed in the usual way by uniform electrostatic charging with exclusion of light, imagewise exposure to produce a charge image on the photoconductor layer, emphasizing the layer surface with formation of a toner image at the charged points, fixing the toner image and washing out the non-toner-free areas of the image Photoconductor layer with a stripping agent.
  • the plate is then treated with the solution according to the invention, the toner image being detached from the image locations of the photoconductor layer. It is then usually preserved with a preservation solution.
  • the plate is then ready for printing.
  • the processing of corresponding electrophotographic materials in planographic printing forms is described in the already mentioned EP-A 34 317 and 246 538.
  • the layer is charged to -450 V with a corona and exposed in a repro camera with 10 halogen spotlights of 600 W each for 18 s.
  • An adhesive assembly from a newspaper page on a signature with blue orientation lines serves as a template.
  • the resulting charge image is made with a toner powder 18 pbw a copolymer of 35% n-butyl methacrylate and 65% styrene and 2 Gt Carbon black pigment developed, and the toner image is fixed by briefly heating to about 170-180 ° C.
  • the photoconductor layer is treated with a solution of 12 Gt Diethylene glycol monoethyl ether, 10 gt n-propanol, 1.4 pbw Sodium metasilicate ⁇ 9 H 2 O and 76.6 pbw water and rinsed with water removed.
  • the plate is scraped off and with a Solution of 95 gt Rapeseed oil fatty acid methyl ester and 5 Gt N-methylpyrrolidone overlaid.
  • the toner layer is washed off with gentle rubbing, the excess solution is scraped off, the plate is washed with water and preserved in the usual manner with a preservative solution. A clay-free planographic printing form is obtained.
  • Example 1 With a solution from 40 pbw 2,5-bis (4-diethylaminophenyl) oxdiazole, 47 gt of the copolymer indicated in Example 1, 10 gt a chlorinated rubber and 2 Gt Astrazon orange R in 400 pbw Tetrahydrofuran, 300 pbw 2-methoxyethanol, 105 pbw Butyl acetate and 14 Gt Methanol an aluminum plate pretreated as in Example 1 is coated and dried. The layer thickness is 5 ⁇ m. The printing plate obtained is, as described in Example 1, charged, exposed, concrete, fixed and decoated. Then the toner layer is washed off with the solution given in Example 1 and the printing form obtained is preserved. A clay-free planographic printing plate is obtained, with which many thousands of error-free prints are obtained.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Printing Plates And Materials Therefor (AREA)
  • Photoreceptors In Electrophotography (AREA)

Description

Die Erfindung betrifft eine Lösung zum Auswaschen von Tonerbildern von auf elektrophotographischem Wege hergestellten Flachdruckformen. Sie betrifft ferner die Verwendung dieser Lösung zum Auswaschen von Tonerbildern von derartigen Druckformen.The invention relates to a solution for washing out toner images of planographic printing forms produced by electrophotography. It also relates to the use of this solution for washing out toner images from such printing forms.

Bei der Herstellung von Flachdruckformen auf elektrophotographischem Wege wird ein Aufzeichnungsmaterial, das einen leitfähigen Schichtträger und eine photoleitfähige Schicht aufweist, elektrostatisch aufgeladen und bildmäßig belichtet, das erhaltene Ladungsbild mit einem elektrophotographischen Entwickler zum Tonerbild entwickelt und die Schicht von den nicht mit Toner bedeckten, bildfreien Stellen mit einer Entschichtungsflüssigkeit weggelöst. Dabei wird an den Nichtbildstellen der hydrophile Schichtträger freigelegt, so daß die dadurch erhaltene Flachdruckform unmittelbar zum Drucken eingesetzt werden kann. Es zeigte sich jedoch, daß die Qualität des Druckbildes durch die auf den verbleibenden Bildstellen der Photoleiterschicht liegende Tonerschicht beeinträchtigt werden kann. Man ist deshalb in solchen Fällen dazu übergegangen, das Tonerbild durch Auswaschen mit einem Kohlenwasserstofflösemittel, das die Photoleiterschicht selbst nicht angreift, zu entfernen.In the production of planographic printing forms by electrophotography, a recording material which has a conductive substrate and a photoconductive layer is electrostatically charged and imagewise exposed, the charge image obtained is developed with an electrophotographic developer to form the toner image and the layer from the non-image-free areas not covered with toner dissolved away with a stripping liquid. The hydrophilic substrate is exposed at the non-image areas, so that the planographic printing plate thus obtained can be used directly for printing. However, it was found that the quality of the printed image can be adversely affected by the toner layer lying on the remaining image points of the photoconductor layer. In such cases, therefore, it has been started to remove the toner image by washing out with a hydrocarbon solvent which does not attack the photoconductor layer itself.

Geeignete Lösungsmittel und deren Anwendung für den beschriebenen Zweck sind z.B. in der EP-A 27 614 und der DE-A 30 05 695 beschrieben. In der EP-A 246 538 wird die Verwendung einer Emulsion aus einer wäßrigen und einer Kohlenwasserstoffphase für den gleichen Zweck beschrieben.
Alle diese Auschwaschlösungen enthalten aromatische oder naphthenische Kohlenwasserstoffe, die auch bei sachgerechter Anwendung sehr unangenehm riechen und deren umweltgerechte Entsorgung problematisch und aufwendig ist.Suitable solvents and their use for the purpose described are described, for example, in EP-A 27 614 and DE-A 30 05 695. EP-A 246 538 describes the use of an emulsion of an aqueous and a hydrocarbon phase for the same purpose.
All of these wash-out solutions contain aromatic or naphthenic hydrocarbons, which smell very unpleasant even when used correctly and whose environmentally friendly disposal is problematic and time-consuming.

Man war deshalb bemüht, diese Lösemittel durch andere, gleichwirkende, weniger unangenehm riechende und leichter zu entsorgende Lösemittel zu ersetzen. Entsprechende Versuche wurden mit einem Walzenauswaschmittel für Druckmaschinen, wie es in der WO 90/03 419 beschrieben ist, durchgeführt. Das dort beschriebene Lösemittel, das aus niederen Alkylestern von aliphatischen C8 - C22-Monocarbonsäuren besteht, ist zwar biologisch abbaubar, nicht toxisch und hat einen niedrigen Dampfdruck; seine Wirkung ist jedoch nicht aktiv genug, d.h. es benötigt zu lange Zeit, um die Tonerschicht zu entfernen.Efforts were therefore made to replace these solvents with other solvents which act in the same way, have a less unpleasant smell and are easier to dispose of. Corresponding experiments were carried out with a roller washout agent for printing presses, as described in WO 90/03 419. The solvent described there, which consists of lower alkyl esters of aliphatic C 8 -C 22 monocarboxylic acids, is biodegradable, non-toxic and has a low vapor pressure; however, its effect is not active enough, ie it takes too long to remove the toner layer.

Aufgabe der Erfindung war es, eine Auswaschlösung für Tonerbilder von elektrophotographisch hergestellten Flachdruckformen vorzuschlagen, die geeignet ist, das Tonerbild innerhalb kurzer Zeit selektiv von der Photoleiterschicht abzulösen, und die nach Gebrauch problemlos entsorgt werden kann.The object of the invention was to propose a washout solution for toner images of electrophotographically produced planographic printing plates which is suitable for selectively detaching the toner image from the photoconductor layer within a short time and which can be disposed of after use without any problems.

Erfindungsgemäß wird eine Auswaschlösung für Tonerbilder von auf elektrophotographischem Wege hergestellten Flachdruckformen vorgeschlagen, die 90 bis 98, vorzugsweise 93 bis 97, Gew.-% mindestens eines (C1-C5)-Alkylesters einer aliphatischen (C8 - C22)-Monocarbonsäure und 2 bis 10, vorzugsweise 3 - 7, Gew.-% eines N-Alkyllactams, bezogen auf die Summe beider Bestandteile, enthält.According to the invention, a wash-out solution for toner images of planographic printing forms produced by electrophotography is proposed which contains 90 to 98, preferably 93 to 97,% by weight of at least one (C 1 -C 5 ) alkyl ester of an aliphatic (C 8 -C 22 ) monocarboxylic acid and 2 to 10, preferably 3 to 7, wt .-% of an N-alkyllactam, based on the sum of both components.

Der Esterbestandteil der Lösung muß flüssig sein und sollte praktisch keine abscheidbaren festen Bestandteile enthalten. Bevorzugt ist mindestens ein Teil des Esters von einer ungesättigten, ggf. auch teilweise hydrierten aliphatischen Monocarbonsäure abgeleitet. Die Ester können in bekannter Weise durch Veresterung einer geeigneten Monocarbonsäure mit einem Alkanol mit 1 bis 5 Kohlenstoffatomen oder durch Umesterung aus einem geeigneten natürlich vorkommenden Fett oder Öl mit dem entsprechenden Alkanol hergestellt werden. Geeignete Ester sind in der WO 90/ 03 419 beschrieben, auf die hierzu verwiesen wird.The ester component of the solution must be liquid and should contain practically no separable solid components. At least part of the ester is preferably derived from an unsaturated, optionally also partially hydrogenated aliphatic monocarboxylic acid. The esters can be prepared in a known manner by esterification of a suitable monocarboxylic acid with an alkanol having 1 to 5 carbon atoms or by transesterification from a suitable naturally occurring fat or oil with the corresponding alkanol. Suitable esters are described in WO 90/03 419, to which reference is made.

Die erfindungsgemäße Lösung enthält als weiteren notwendigen Bestandteil ein N-Alkyllactam. Diese Verbindung weist eine Alkylgruppe mit etwa 1 bis 5, bevorzugt 1 bis 3 Kohlenstoffatomen auf. Das Lactam kann vorzugsweise 5 oder 6 Ringglieder enthalten und ist im allgemeinen gesättigt. Beispiele für geeignete Lactame sind N-Methyl-, N-Ethyl- und N-Isopropyl-pyrrolidon, N-Methyl- und N-Ethyl-2-piperidon. Die N-Alkyl-pyrrolidone, insbesondere das N-Methyl-pyrrolidon, werden wegen ihrer allgemeinen Verfügbarkeit besonders bevorzugt.The solution according to the invention contains an N-alkyllactam as a further necessary component. This compound has an alkyl group with about 1 to 5, preferably 1 to 3, carbon atoms. The lactam may preferably contain 5 or 6 ring members and is generally saturated. Examples of suitable lactams are N-methyl-, N-ethyl- and N-isopropyl-pyrrolidone, N-methyl- and N-ethyl-2-piperidone. The N-alkyl-pyrrolidones, especially the N-methyl-pyrrolidone, are particularly preferred because of their general availability.

Die erfindungsgemäße Auswaschlösung kann weiterhin übliche Zusätze, wie Korrosionsinhibitoren oder oberflächenaktive Mittel, in kleineren Mengen enthalten. Entsprechende Zusätze sind in der WO 90/03 419 beschrieben. Wenn oberflächenaktive Mittel zugesetzt werden, liegt deren Menge im allgemeinen im Bereich von 0,5 bis 2 Gew.-%, bezogen auf die Gesamtmenge von aliphatischem Alkylester und N-Alkyllactam.The washout solution according to the invention can furthermore contain conventional additives, such as corrosion inhibitors or surface-active agents, in smaller amounts. Corresponding additives are described in WO 90/03 419. When surfactants are added, the amount thereof is generally in the range of 0.5 to 2% by weight based on the total amount of the aliphatic alkyl ester and N-alkyl lactam.

Das Verfahren zur Anwendung der erfindungsgemäßen Lösung sowie elektrophotographische Materialien, die nach diesem Verfahren verarbeitet werden können, sind in den EP-A 34 317 und 246 538 beschrieben.The process for using the solution according to the invention and electrophotographic materials which can be processed by this process are described in EP-A 34 317 and 246 538.

Die erfindungsgemäße Auswaschlösung bewirkt eine rasche Ablösung der Tonerschicht von den Bildstellen der Photoleiterschicht der betonerten und bildmäßig entschichteten Druckplatte, ohne daß die Bildstellen der Photoleiterschicht in nennenswertem Umfang angegriffen werden. Sie wirkt damit ähnlich gut wie die bisher für den gleichen Zweck eingesetzten hochsiedenden, insbesondere aromatischen Kohlenwasserstoffe. Gegenüber diesen Substanzen unterscheidet sich die erfindungsgemäße Lösung durch ihre leichte biologische Abbaubarkeit und ihre Ungiftigkeit. Sie kann ohne besondere Vorsichtsmaßnahmen gehandhabt werden, da zum einen ihr Dampfdruck sehr niedrig ist und zum anderen die davon ausgehenden Dämpfe nicht gesundheitsschädlich sind.The washout solution according to the invention brings about a rapid detachment of the toner layer from the image areas of the photoconductor layer of the concrete-coated and image-delaminated printing plate without the image areas of the photoconductor layer being attacked to any appreciable extent. It works just as well as the high-boiling, especially aromatic, hydrocarbons used for the same purpose. The solution according to the invention differs from these substances by its easy biodegradability and its non-toxicity. It can be handled without special precautionary measures, because on the one hand its vapor pressure is very low and on the other hand the vapors emanating from it are not harmful to health.

Die erfindungsgemäße Auswaschlösung kann in üblicher Weise entweder manuell unter Überwischen der Plattenoberfläche oder in einer geeigneten Auswaschvorrichtung angewendet werden.The washout solution according to the invention can be applied in the usual way either manually by wiping the plate surface or in a suitable washout device.

Die mit der erfindungsgemäßen Auswaschlösung zu verarbeitenden Druckplatten sind bekannt. Sie bestehen im allgemeinen aus einem leitfähigen Schichtträger, bevorzugt einer Aluminiumplatte, und einer Photoleiterschicht. Diese enthält bevorzugt einen organischen Photoleiter, ein polymeres Bindemittel, das vorzugsweise wasserunlöslich und in wäßrig-alkalischen Lösungen löslich ist und ggf. weitere übliche Bestandteile. Geeignete elektrophotographische Materialien sind in den EP-A 31 481, 34 317 und 246 538 beschrieben.The printing plates to be processed with the washout solution according to the invention are known. They generally consist of a conductive substrate, preferably an aluminum plate, and a photoconductor layer. This preferably contains an organic photoconductor, a polymeric binder which is preferably water-insoluble and soluble in aqueous-alkaline solutions and, if appropriate, other conventional constituents. Suitable electrophotographic materials are described in EP-A 31 481, 34 317 and 246 538.

Die Verarbeitung der Materialien erfolgt in üblicher Weise durch gleichmäßige elektrostatische Aufladung unter Lichtausschluß, bildmäßige Belichtung zur Erzeugung eines Ladungsbildes auf der Photoleiterschicht, Betonerung der Schichtoberfläche unter Ausbildung eines Tonerbildes an den aufgeladenen Stellen, Fixieren des Tonerbildes und Auswaschen der nicht von Toner bedeckten bildfreien Bereiche der Photoleiterschicht mit einem Entschichtungsmittel. Danach wird die Platte mit der erfindungsgemäßen Lösung behandelt, wobei das Tonerbild von den Bildstellen der Photoleiterschicht abgelöst wird. Üblicherweise wird anschließend mit einer Konservierungslösung konserviert. Die Platte ist danach druckfertig. Die Verarbeitung entsprechender elektrophotographischer Materialien in Flachdruckformen ist in den bereits erwähnten EP-A 34 317 und 246 538 beschrieben.The materials are processed in the usual way by uniform electrostatic charging with exclusion of light, imagewise exposure to produce a charge image on the photoconductor layer, emphasizing the layer surface with formation of a toner image at the charged points, fixing the toner image and washing out the non-toner-free areas of the image Photoconductor layer with a stripping agent. The plate is then treated with the solution according to the invention, the toner image being detached from the image locations of the photoconductor layer. It is then usually preserved with a preservation solution. The plate is then ready for printing. The processing of corresponding electrophotographic materials in planographic printing forms is described in the already mentioned EP-A 34 317 and 246 538.

Die folgenden Beispiele erläutern bevorzugte Ausführungsformen der erfindungsgemäßen Lösung und ihre Anwendung. In den Beispielen sind, wenn nichts anderes angegeben ist, alle Mengenverhältnisse und Prozentangaben in Gewichtseinheiten zu verstehen. Die Mengen sind in Gewichtsteilen (Gt) angegeben.The following examples explain preferred embodiments of the solution according to the invention and their use. In the examples, unless otherwise stated, all proportions and percentages are to be understood in weight units. The amounts are given in parts by weight (pbw).

Beispiel 1example 1

Mit einer Lösung von 40 Gt 2-Phenyl-4-(2-chlorphenyl)-5-(4-diethylaminophenyl)oxazol, 60 Gt eines Styrol/Maleinsäureanhydrid-Mischpolymerisats, 2 Gt Astrazonorange R (C.I. 48 040) und 0,2 Gt Rhodamin B (C.I. 45 170) in 400 Gt Tetrahydrofuran, 200 Gt 2-Methoxy-ethanol, 100 Gt Butylacetat und 28 Gt Methanol wird eine 0,3 mm starke elektrolytisch aufgerauhte, anodisch oxydierte und mit einer wäßrigen Lösung von Polyvinylphosphonsäure behandelte Aluminiumplatte so beschichtet, daß nach dem Trocknen eine etwa 5µm dicke Photoleiterschicht erhalten wird. Die Schicht wird mit einer Corona auf -450 V aufgeladen und in einer Reprokamera mit 10 Halogenstrahlern von je 600 W Leistung 18s belichtet. Als Vorlage dient eine Klebemontage aus einer Zeitungsseite auf einem Standbogen mit blauen Orientierungslinien. Das entstandene Ladungsbild wird mit einem Tonerpulver aus 18 Gt eines Mischpolymerisats aus 35 % n-Butylmethacrylat und 65 % Styrol und 2 Gt Rußpigment entwickelt, und das Tonerbild wird durch kurzes Erwärmen auf etwa 170 - 180 °C fixiert. An den Nichtbildstellen wird die Photoleiterschicht durch Behandeln mit einer Lösung von 12 Gt Diethylenglykolmonoethylether, 10 Gt n-Propanol, 1,4 Gt Natriummetasilikat × 9 H2O und 76,6 Gt Wasser und Abspülen mit Wasser entfernt. Die Platte wird abgerakelt und mit einer Lösung von 95 Gt Rapsölfettsäuremethylester und 5 Gt N-Methylpyrrolidon überschichtet. Unter leichtem Reiben wird die Tonerschicht abgewaschen, die überschüssige Lösung abgerakelt, die Platte mit Wasser gewaschen und in üblicher Weise mit einer Konservierungslösung konserviert. Es wird eine tonfreie Flachdruckform erhalten.With a solution from 40 pbw 2-phenyl-4- (2-chlorophenyl) -5- (4-diethylaminophenyl) oxazole, 60 pbw a styrene / maleic anhydride copolymer, 2 Gt Astrazon Orange R (CI 48 040) and 0.2 pbw Rhodamine B (CI 45 170) in 400 pbw Tetrahydrofuran, 200 pbw 2-methoxyethanol, 100 pbw Butyl acetate and 28 pbw Methanol a 0.3 mm thick electrolytically roughened, anodically oxidized and treated with an aqueous solution of polyvinylphosphonic aluminum plate is coated in such a way that an approximately 5 µm thick photoconductor layer is obtained after drying. The layer is charged to -450 V with a corona and exposed in a repro camera with 10 halogen spotlights of 600 W each for 18 s. An adhesive assembly from a newspaper page on a signature with blue orientation lines serves as a template. The resulting charge image is made with a toner powder 18 pbw a copolymer of 35% n-butyl methacrylate and 65% styrene and 2 Gt Carbon black pigment developed, and the toner image is fixed by briefly heating to about 170-180 ° C. At the non-image points, the photoconductor layer is treated with a solution of 12 Gt Diethylene glycol monoethyl ether, 10 gt n-propanol, 1.4 pbw Sodium metasilicate × 9 H 2 O and 76.6 pbw water and rinsed with water removed. The plate is scraped off and with a Solution of 95 gt Rapeseed oil fatty acid methyl ester and 5 Gt N-methylpyrrolidone overlaid. The toner layer is washed off with gentle rubbing, the excess solution is scraped off, the plate is washed with water and preserved in the usual manner with a preservative solution. A clay-free planographic printing form is obtained.

BEISPIEL 2EXAMPLE 2

Mit einer Lösung von 40 Gt 2,5-Bis-(4-diethylaminophenyl)-oxdiazol, 47 Gt des in Beispiel 1 angegebenen Mischpolymerisats, 10 Gt eines Chlorkautschuks und 2 Gt Astrazonorange R in 400 Gt Tetrahydrofuran, 300 Gt 2-Methoxy-ethanol, 105 Gt Butylacetat und 14 Gt Methanol wird eine wie in Beispiel 1 vorbehandelte Aluminiumplatte beschichtet und getrocknet. Die Schichtdicke beträgt 5 µm.
Die erhaltene Druckplatte wird, wie in Beispiel 1 beschrieben, aufgeladen, belichtet, betonert, fixiert und entschichtet. Dann wird die Tonerschicht mit der in Beispiel 1 angegebenen Lösung abgewaschen und die erhaltene Druckform konserviert. Es wird eine tonfreie Flachdruckform erhalten, mit der viele Tausend fehlerfreie Drucke erhalten werden.With a solution from 40 pbw 2,5-bis (4-diethylaminophenyl) oxdiazole, 47 gt of the copolymer indicated in Example 1, 10 gt a chlorinated rubber and 2 Gt Astrazon orange R in 400 pbw Tetrahydrofuran, 300 pbw 2-methoxyethanol, 105 pbw Butyl acetate and 14 Gt Methanol an aluminum plate pretreated as in Example 1 is coated and dried. The layer thickness is 5 µm.
The printing plate obtained is, as described in Example 1, charged, exposed, concrete, fixed and decoated. Then the toner layer is washed off with the solution given in Example 1 and the printing form obtained is preserved. A clay-free planographic printing plate is obtained, with which many thousands of error-free prints are obtained.

Claims (5)

  1. Washing solution for toner images of electrophotographically produced planographic printing members which contains 90-98 wt.% of at least one (C1-C5) alkyl ester of an aliphatic (C8-C22) monocarboxylic acid and 2 to 10 wt.% of an N-alkyllactam, relative to the sum of both constituents.
  2. Washing solution according to claim 1, characterised in that it contains 93-97 wt.% of the alkyl ester and 3-7 wt.% of the N-alkyllactam.
  3. Washing solution according to claim 1, characterised in that the alkyl ester contains 1 to 3 C atoms in the alkyl group.
  4. Washing solution according to claim 1, characterised in that at least a proportion of the monocarboxylic acid alkyl ester is derived from an unsaturated monocarboxylic acid.
  5. Washing solution according to claim 1, characterised in that the N-alkyllactam is an N-alkylpyrrolidone.
EP19940100534 1993-01-23 1994-01-15 Cleansing solution for toner images of electrophotographic lithographic printing plates Expired - Lifetime EP0608728B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE9300942U DE9300942U1 (en) 1993-01-23 1993-01-23 Wash-out solution for toner images from electrophotographically produced planographic printing plates
DE9300942U 1993-01-23

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EP0608728A1 EP0608728A1 (en) 1994-08-03
EP0608728B1 true EP0608728B1 (en) 1997-07-30

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Family Applications (1)

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EP19940100534 Expired - Lifetime EP0608728B1 (en) 1993-01-23 1994-01-15 Cleansing solution for toner images of electrophotographic lithographic printing plates

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EP (1) EP0608728B1 (en)
DE (2) DE9300942U1 (en)
DK (1) DK0608728T3 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE504066C2 (en) * 1995-03-08 1996-10-28 Svenska Rapsoljebolaget Ab Use of fatty acid alkyl esters for brush washing and / or paint removal

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DK600484D0 (en) * 1984-12-14 1984-12-14 Cps Kemi Aps CASE FOR THINING AND / OR REMOVING PRINTING AND SERIGRAPHY COLORS
DK533188D0 (en) * 1988-09-26 1988-09-26 Aarhus Oliefabrik As APPLICATION OF (C1-C5) ALKYL ESTERS OF ALIFATIC (C8-C22) MONOCARBOXYLIC ACIDS FOR THE PURIFICATION OF Grease, PAINT, PRINT COLORS O.L. AND CLEANER CONTAINING SUCH ESTERS
DE4034765A1 (en) * 1990-11-02 1992-05-07 Schwegmann Bernd Gmbh Co Kg Cleaning and regenerating compsn. for offset printing - contg. aliphatic di:basic ester and/or methyl pyrrolidone, aliphatic and/or aromatic hydrocarbon for rubber
GB9101850D0 (en) * 1991-01-29 1991-03-13 Du Pont Howson Ltd Improvements in or relating to printing

Also Published As

Publication number Publication date
DE9300942U1 (en) 1993-05-13
EP0608728A1 (en) 1994-08-03
DK0608728T3 (en) 1998-03-09
DE59403489D1 (en) 1997-09-04

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