JP2001213033A - Method of making plate and plate-making apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of making a plate for a plate material and a plate-making apparatus capable of corresponding to digital image data and producing multiple sheets of printed materials having clear images in low cost at high speed. SOLUTION: This plate-making apparatus 1 comprises an ink jet image plotting apparatus that ejects oil-based ink from an ejection head by utilizing an electrostatic field as an image forming means for directly forming an image on the plate material 9 in accordance with a signal of image data, and an image fixing means 5 for obtaining a machine plate by fixing the image formed by the image forming means. When a malfunction occurs, the image forming is stopped and/or the cause of the malfunction is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate making method and a plate making apparatus for performing digital plate making, and more particularly, to a plate making method and a plate making apparatus using oil-based ink and having good plate making quality and printing quality.

[0002]

2. Description of the Related Art In lithographic printing, a printing plate is provided with a printing ink receptive region and a printing ink repellent region corresponding to an image original, and printing is performed by adhering printing ink to the ink receiving region. . Usually, hydrophilic and lipophilic (ink-receptive) areas are formed imagewise on the surface of the printing plate, and the hydrophilic areas are made ink-repellent by using a fountain solution.

To record an image on a printing plate (plate making), an image document is first output in analog or digital form to a silver halide photographic film, through which a diazo resin or a photopolymerizable photopolymer photosensitive material (printing plate) is printed. Is generally performed by exposing the non-image area to elution and removal mainly using an alkaline solution.

In recent years, in the lithographic printing method, due to the recent improvement in digital drawing technology and the demand for more efficient processes,
Many systems for directly drawing digital image information on a printing plate have been proposed. This is CTP (Computer
-to-plate) or DDPP (Digital Direct Pri
nting Plate). As a plate making method, for example, there is a system for recording an image in an optical mode or a thermal mode using a laser, and a part of the system has been put into practical use.

However, in this plate making method, in both the light mode and the heat mode, plate making is generally performed by processing with an alkaline developing solution after laser recording to dissolve and remove non-image portions.
Alkaline waste liquid is discharged, which is not preferable for environmental protection.

On the other hand, since the above-mentioned method using a laser is expensive and large, a system using an ink jet method, which is an inexpensive and compact drawing apparatus, has been tried.

Japanese Patent Application Laid-Open No. 64-27953 discloses a method of performing plate making by drawing with an ink jet using a lipophilic wax ink on a hydrophilic plate material. In this method, the mechanical strength of the image area is low because the image is formed with wax, and the adhesion to the hydrophilic surface of the printing plate is insufficient, so that the printing durability is low.

In order to obtain a high quality image, it is necessary to fly ink droplets accurately.
A head having a high-precision meniscus shape is required, and the head needs to be brought close to the plate material in order to fly fine dots. Accordingly, if dust or the like adheres to the head, the meniscus is deformed and the ink droplet cannot fly accurately, and the head with the deformed meniscus comes into contact with the plate material and cannot fly the ink droplet. In particular, in a mechanism that uses an electrostatic field to fly ink, the drum or the like that supports the plate material has conductivity, so that a short circuit occurs due to contact with the head, and the plate or drum may be damaged. Invite. In addition, floating dust and the like near the plate material adversely affect high image quality. Further, when a defect occurs in an image formed on a plate material for these reasons, it is necessary to stop the plate making apparatus and remove the cause.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a digital plate making method and a plate making apparatus which does not require a developing process, and which is inexpensive and simple. Accordingly, an object of the present invention is to provide a plate making method and a plate making apparatus capable of forming a high quality image on a plate material.

[0010]

According to a first aspect of the present invention, there is provided a plate making method comprising: an electrostatic ink jet method for discharging oil-based ink by using an electrostatic field based on a signal of image data; In the plate making method of forming an image directly on a plate material and fixing the image to form a printing plate, when an abnormality occurs, the image formation is stopped and / or the cause of the abnormality is removed. .

The plate-making method according to claim 2, wherein the oil-based ink is a solid and hydrophobic resin particle at least at room temperature in a non-aqueous solvent having a specific electric resistance of 10 ⁹ Ωcm or more and a dielectric constant of 3.5 or less. Are dispersed.

According to a third aspect of the invention, there is provided an ink-jet drawing apparatus for discharging oil-based ink from a discharge head using an electrostatic field as an image forming means for forming an image directly on a plate material based on a signal of image data. And an image fixing unit for fixing the image formed by the image forming unit to obtain a printing plate.
Alternatively, an abnormality cause removing unit is provided, and based on an output from the abnormality detecting unit, the operation of the image forming unit is stopped at least temporarily and / or the abnormality cause removing unit is activated.

According to a fourth aspect of the present invention, there is provided a plate making apparatus comprising a recording head foreign matter adhesion detecting device for detecting foreign matter adhesion to a recording head of the ink jet drawing apparatus as the abnormality detecting means.

According to a fifth aspect of the present invention, in the plate making apparatus, a dust detector for detecting dust in the plate making apparatus and / or on the plate material is provided as the abnormality detecting means.

According to a sixth aspect of the present invention, in the plate making apparatus, the abnormality detecting means includes a vibration detecting device for detecting vibration of the plate making device and / or the recording head.

The plate-making apparatus according to claim 7, wherein the oil-based ink is a solid and hydrophobic resin particle at least at room temperature in a non-aqueous solvent having a specific electric resistance of 10 ⁹ Ωcm or more and a dielectric constant of 3.5 or less. Are dispersed.

In the plate making device according to the present invention, the image fixing means has a heating means using a heat roller and / or an infrared lamp, a halogen lamp or a xenon flash lamp.

According to a ninth aspect of the present invention, the heating means is arranged and / or controlled so as to gradually increase the temperature of the plate material when fixing the image.

According to a tenth aspect of the present invention, at the time of drawing on the plate material, the main scanning is performed by rotating a drum on which the plate material is mounted.

In the plate making apparatus according to the present invention, the ejection head is a single-channel head or a multi-channel head, and performs sub-scanning by moving the ejection head in the axial direction of the drum.

According to a twelfth aspect of the present invention, when performing drawing on the plate material, sub-scanning is performed by nipping and moving the plate material with at least a pair of capstan rollers.

According to a plate making apparatus of the present invention, the discharge head is a single-channel head or a multi-channel head, and the main scan is performed by moving the discharge head in a direction perpendicular to the direction of travel of the plate material. Do.

In the plate making apparatus according to the present invention, the discharge head is a full line head having a length substantially equal to the width of the plate material.

According to a plate making apparatus of the present invention, the ink jet drawing apparatus has an ink supply means for supplying the oil-based ink to the discharge head.

A plate making apparatus according to a sixteenth aspect has an ink collecting means for collecting the oil-based ink from the discharge head, and circulates the ink.

A plate making apparatus according to a seventeenth aspect has dust removing means for removing dust present on the surface of the plate material before and / or during drawing on the plate material.

In the plate making apparatus according to the present invention, the ink jet drawing apparatus has stirring means for stirring the oil-based ink in an ink tank storing the oil-based ink.

[0028] In a plate making apparatus according to a nineteenth aspect, the ink jet drawing apparatus has ink temperature management means for managing the temperature of the oil-based ink in an ink tank storing the oil-based ink.

According to a twentieth aspect of the present invention, the ink jet drawing apparatus has an ink concentration control means for controlling the concentration of the oil-based ink.

The plate making apparatus according to the present invention has cleaning means for cleaning the discharge head.

[0031]

Embodiments of the present invention will be described below in detail. The present invention relates to a printing plate (printing plate)
When an image is formed by an inkjet method in which an oil-based ink is ejected by an electrostatic field, an abnormality which hinders image formation is detected and solved.

In the present invention, the size of the ejected ink droplet is determined by the size of the tip of the ejection electrode or the condition for forming the electric field. Therefore, by using a small ejection electrode or adjusting the electric field forming conditions, a small ink droplet can be obtained without reducing the ejection nozzle diameter or the ejection slit width. Therefore, the present invention provides a plate making method and a plate making device capable of controlling a minute image without the problem of ink clogging of the head and obtaining a printing plate capable of printing a large number of clear images.

An example of the configuration of a plate making apparatus used to carry out the plate making method of the present invention will be described below. 1 and 2 are general configuration diagrams of the plate making apparatus. FIG. 3 shows a control unit of the plate making apparatus;
3 is a schematic configuration example of a drawing unit including an ink supply unit and a head detachment mechanism. FIG. 4 is a block diagram showing a detecting means for detecting an abnormal discharge head meniscus, and FIG. 5 is a block diagram showing a detecting means for detecting dust and the like. 6 to
FIG. 12 is for explaining the ink jet drawing apparatus provided in the plate making apparatus of FIGS.

First, the plate making process according to the present invention will be described with reference to an overall configuration diagram of a plate making apparatus having a structure in which a plate material is mounted on a drawing drum 11 as shown in FIG. However, the present invention is not limited to the following configuration examples.

The drum 11 is usually made of metal such as aluminum, stainless steel or iron, plastic, glass or the like. Particularly, in the case of a metal drum, its surface is often subjected to, for example, anodizing or chrome plating in order to enhance abrasion resistance and rust prevention. The drum 11 may have a heat insulating material on its surface as described later. Further, it is preferable that the drum 11 has a grounding function as a counter electrode of the discharge head electrode in the electrostatic field discharge. On the other hand, when the insulating property of the substrate of the plate material is high, it is preferable to provide a conductive layer on the substrate. In this case, it is desirable to provide a means for grounding the conductive layer. Further, even when a heat insulating material is provided on the drum 11 as described above, drawing is facilitated by providing a means for grounding the plate material. In this case, a known means such as a brush, a leaf spring, or a roller having conductivity can be used.

Further, the plate making apparatus 1 has an ink jet drawing apparatus 2, which can
In accordance with the image data sent from the printer, an oil-based ink is ejected onto the plate material 9 mounted on the drum 11 to form an image.

The plate making device 1 has a fixing device 5 for strengthening the oil-based ink image drawn on the plate material 9. If necessary, a plate surface desensitizing device 6 used as needed for the purpose of enhancing the hydrophilicity of the surface of the plate material 9 may be provided.
Further, the plate making apparatus 1 includes a dust removing unit 10 for removing dust existing on the surface of the plate material 9 before and / or during drawing on the plate material 9.
Having. Thereby, it is possible to effectively prevent the ink from adhering to the plate material 9 due to the transmission of dust between the ejection head and the plate material during plate making, and to perform good plate making. Dust removing means 10
In addition to known non-contact methods such as suction removal, blow-off removal, and electrostatic removal, a contact method using a brush, a roller, or the like can be used. In the present invention, desirably, any one of air suction, air blow-off, and the like Can be used in combination.

Further, an automatic plate feeding device 7 for automatically supplying the plate material 9 onto the drum 11 and an automatic plate discharging device 8 for automatically removing the plate material 9 after drawing from the drum 11 are provided. Good. By using the automatic plate feeding device 7 and the automatic plate discharging device 8, the plate making operation becomes simpler and the plate making time is shortened, so that the effect of the present invention can be further enhanced.

Referring to FIG. 1 and partly in FIG.
The process of producing a printing plate according to the above will be described below.

First, the plate material 9 is mounted on the drum 11 using the automatic plate feeding device 7. At this time, the printing plate 9 is closely fixed to the drum 11 by a mechanical method using a well-known printing head / butt holding device, an air suction device, or the like, or the like, whereby the printing edge of the printing plate flaps. It is possible to prevent the ink jet drawing device 2 from being damaged by contact with the ink jet drawing device 2. Means for adhering the plate material 9 to the drum 11 only around the drawing position of the ink jet drawing device 2 is provided, and at least at the time of drawing, the plate material 9 is prevented from coming into contact with the ink jet drawing device 2 by acting. You can also. Specifically, for example, there is a method of disposing a pressing roller upstream and downstream of the drawing position on the drum 11.
Further, when the drawing is not performed, it is desirable to keep the ejection head away from the printing plate material, which can effectively prevent the ink jet drawing apparatus 2 from causing troubles such as contact damage.

The image data arithmetic and control unit 21 receives image data from an image scanner, a magnetic disk device, an image data transmission device, etc., performs color separation as necessary, and applies an appropriate pixel to the separated data. Divide calculation into number and gradation number. Furthermore, in order to draw an oil-based ink image in a halftone manner using the inkjet discharge head 22 (see FIG. 3 and described in detail later) included in the inkjet drawing apparatus 2, the halftone dot area ratio is also calculated. Also, as described below,
The image data calculation control unit 21 controls the movement of the inkjet discharge head 22 and the discharge timing of the oil-based ink, and also controls the operation timing of the drum 11 and the like as necessary. The calculation data input to the image data calculation control unit 21 is temporarily stored in a buffer. The image data calculation control unit 21 rotates the drum 11 and
Is brought closer to the position close to the drum 11 by the head separation / contact device 31. Discharge head 22 and plate 9 on drum 11
The distance from the surface is controlled to a predetermined distance during drawing by mechanical distance control such as an abutment roller or control of a head separation / contact device by a signal from an optical distance detector. By such distance control, good plate making can be performed without the dot diameter becoming non-uniform due to the lifting of the plate material or the dot diameter changing especially when vibration is applied to the plate making machine.

As the discharge head 22, a single-channel head, a multi-channel head, or a full-line head can be used, and the main scanning is performed by rotating the drum 11. In the case of a multi-channel head having a plurality of discharge units or a full line head, the arrangement direction of the discharge units is set in the axial direction of the drum 11. Further, in the case of a single channel head or a multi-channel head, the discharge head 22 is moved in the axial direction of the drum 11 by one rotation of the drum 11 by the image data calculation control unit 21 to obtain the discharge position and the net obtained by the above calculation. The oil-based ink is discharged onto the plate material 9 mounted on the drum 11 at a point area ratio. As a result, a halftone image corresponding to the density of the print document is drawn on the plate material 9 with the oil-based ink. This behavior is
An oil-based ink image for one color of the printing original is formed on the plate material 9 and continues until a printing plate is completed. On the other hand, when the ejection head 22 is a full line head having a length substantially equal to the width of the drum 11, one rotation of the drum 11 forms an oil-based ink image of one color of a print document on the plate 9. A printing plate is completed. By performing the main scanning by rotating the drum 11 in this manner, the position accuracy in the main scanning direction can be improved, and high-speed drawing can be performed.

Next, in order to protect the ejection head 22, the ejection head 22 is retracted away from a position close to the drum 11. This separation / contact means operates so that the ejection head is separated from the drum by at least 500 μm except during drawing. The separation / contact operation may be performed in a sliding manner, or the ejection head 22 may be fixed by an arm fixed to a certain axis, and the arm may be moved around the axis to move like a pendulum. By retracting the ejection head 22 during non-drawing as described above, the ejection head 22 can be protected from physical damage or contamination, and a long life can be achieved.

Further, the formed oil-based ink image is reinforced by the fixing device 5. As a means of fixing ink,
Known means such as heat fixing and solvent fixing can be used. In the heat fixing, an infrared lamp, a halogen lamp, a xenon flash lamp irradiation, hot air fixing using a heater, and heat roll fixing are generally used. In this case, the drum 9 is heated in order to enhance the fixing property.
Is heated in advance, drawing is performed while applying hot air, the drum 11 is coated with a heat insulating material, and the drum 11 is fixed at the time of fixing.
It is effective to take measures such as separating the plate material 9 from the substrate and heating only the plate material 9 alone or in combination.
Flash fixing using a xenon lamp or the like is known as a method for fixing electrophotographic toner, and has an advantage that fixing can be performed in a short time. When using a paper plate,
The water inside the plate evaporates rapidly due to the rapid temperature rise,
Since a phenomenon called blister, in which unevenness occurs on the plate material surface, occurs, the drum 1 is heated so that the temperature of the paper plate material gradually increases.
It is preferable to gradually increase the power supply to the heat source while rotating 1, or to change the rotation speed from high speed to low speed with constant power supply. Alternatively, the paper plate material may be gradually heated by disposing a plurality of fixing units in the rotation direction of the drum 11 and changing the distance to the plate material 9 and / or the supplied power.

In solvent fixing, a solvent capable of dissolving the resin component in the ink, such as methanol or ethyl acetate, is sprayed or exposed to steam, and excess solvent vapor is recovered. In addition, at least in the process from the formation of the oil-based ink image by the ejection head 22 to the fixing by the fixing device 5, it is preferable that nothing is kept in contact with the image on the plate material 9.

An example of the configuration of a plate making apparatus for performing sub-scanning by moving the plate material 9 will be described with reference to FIG. However, the present invention is not limited to the following configuration examples.

The plate material 9 includes two pairs of capstan rollers 1.
2, and the image is drawn by the ink jet drawing apparatus 2 using the data divided and calculated by the image data calculation control unit 21 into an appropriate number of pixels and gradations. It is preferable that a grounding means 13 is provided at a portion where the drawing is performed by the ink jet drawing apparatus 2 so as to be a counter electrode of the discharge head electrode in the electrostatic field discharge, thereby facilitating the drawing. On the other hand, when the insulating property of the base of the plate 9 is high, it is preferable to provide a conductive layer on the base. In this case, the conductive layer is formed on the conductive layer by means of a known conductive brush, leaf spring, roller or the like. It is desirable to take the ground.

FIG. 2 shows an apparatus using a sheet plate material, but a roll plate material is also suitably used. In this case, it is desirable to provide a sheet cutter upstream of the automatic plate discharging device.

The plate making device 1 has a fixing device 5 for strengthening the oil-based ink image drawn on the plate material 9. Further, a plate surface desensitizing device 6 used as needed for the purpose of enhancing the hydrophilicity of the surface of the plate material 9 may be provided. In addition, the plate making apparatus 1 has dust removing means 10 for removing dust existing on the surface of the plate material before drawing on the plate material 9 and / or during drawing.
Thereby, it is possible to effectively prevent the ink from adhering to the plate material due to the transmission of dust between the discharge head and the plate material during the plate making, and to perform good plate making. As the dust removing means 10, besides a known non-contact method such as suction removal, blowing removal, and electrostatic removal, a contact method using a brush, a roller or the like can be used. Or a combination thereof.

Further, it is preferable to provide an automatic plate feeding device 7 for automatically supplying the plate material 9 and an automatic plate discharging device 8 for automatically removing the plate material 9 after drawing. By using the automatic plate feeding device 7 and the automatic plate discharging device 8, the plate making operation becomes simpler and the plate making time is shortened, so that the effect of the present invention can be further enhanced.

Referring to FIG. 2 and partly in FIG.
Will be described in more detail below.

First, the plate material 9 is transported by using the automatic plate feeding device 7 and the cap stun roller 12. At this time, by providing a plate material guide means (not shown) as necessary, it is possible to prevent the plate head / tail of the plate material from fluttering and coming into contact with the ink jet drawing apparatus 2 and being damaged. In addition, means for preventing the plate material 9 from being loosened only around the drawing position of the ink jet drawing device 2 is provided to prevent the plate material 9 from contacting the ink jet drawing device 2 at least when drawing. You can also. Specifically, for example, there is a method of arranging a pressing roller upstream and downstream of the drawing position. Further, when no drawing is performed, it is desirable to keep the ejection head away from the plate material 9, which can effectively prevent the ink jet drawing device 2 from causing troubles such as contact damage.

Image data from a magnetic disk device or the like
The image data arithmetic control unit 21 calculates the discharge position of the oil-based ink and the halftone dot area ratio at that position in accordance with the input image data. These calculation data are temporarily stored in the buffer. The image data calculation control unit 21 controls the movement of the ejection head 22, the ejection timing control of the oil-based ink, and the operation timing control of the capstan roller. Move closer to the close position. The distance between the ejection head 22 and the surface of the plate material 9 was maintained at a predetermined distance during drawing by mechanical distance control such as an abutment roller, or control of a head separation device by a signal from an optical distance detector. It is. By such distance control, good plate making can be performed without the dot diameter becoming non-uniform due to the lifting of the plate material or the dot diameter changing especially when vibration is applied to the plate making machine.

As the ejection head 22, a single-channel head, a multi-channel head, or a full-line head can be used. In the case of a multi-channel head having a plurality of ejection sections, the arrangement direction of the ejection sections is set substantially parallel to the traveling direction of the printing plate. Further, in the case of a single channel head or a multi-channel head, the ejection head 22 is moved by the image data calculation control unit 21 in the direction orthogonal to the traveling direction of the plate material 9 every time the plate material moves, and the ejection obtained by the above calculation is performed. Plate material 9 with oil-based ink at position and dot area ratio
To be discharged. As a result, a halftone image corresponding to the density of the print document is drawn on the plate material 9 with the oil-based ink. This operation continues until an oil-based ink image for one color of the printing original is formed on the plate material 9 and a printing plate is completed. On the other hand, the ejection head 22
Is a full line head having substantially the same length as the width of the plate 9, the arrangement direction of the ejection units is set to a direction substantially orthogonal to the running direction of the plate, and the plate 9 passes through the drawing unit. By doing so, an oil-based ink image for one color of the printing original is formed on the plate material 9, and a printing plate is completed.

In order to protect the discharge head 22, it is preferable that the discharge head 22 is retracted away from a position close to the plate material 9. This separation / contact means operates so that the ejection head is separated from the plate material 9 by at least 500 μm except during drawing. The detachment operation may be a slide type, or the ejection head may be fixed by an arm fixed to a certain axis, and the arm may be moved around the axis to move like a pendulum. By retracting the ejection head during non-drawing in this way, the ejection head can be protected from physical damage or contamination, and a long life can be achieved.

Further, the formed oil-based ink image is reinforced by the fixing device 5. As a means of fixing ink,
Known means such as heat fixing and solvent fixing can be used. In the heat fixing, an infrared lamp, a halogen lamp, a xenon flash lamp irradiation, hot air fixing using a heater, and heat roll fixing are generally used. Flash fixing using a xenon lamp or the like is known as a method for fixing electrophotographic toner, and has an advantage that fixing can be performed in a short time. Also, when a paper plate material is used, a phenomenon called blister occurs in which the water inside the plate material evaporates rapidly due to a rapid temperature rise, and irregularities are generated on the plate material surface.
It is preferable to arrange a plurality of fixing devices and change the power supply and / or the distance of the fixing device to the plate material 9 so as to gradually increase the temperature of the paper plate material in order to prevent blisters of the plate material 9. .

In solvent fixing, a solvent capable of dissolving the resin component in the ink, such as methanol or ethyl acetate, is sprayed or exposed to steam, and excess solvent vapor is recovered. In addition, at least in the process from the formation of the oil-based ink image by the ejection head 22 to the fixing by the fixing device 5, it is preferable that nothing is kept in contact with the image on the plate material 9.

The printing process after the printing plate is formed is the same as the known lithographic printing method. That is, the printing plate on which the oil-based ink image is drawn is mounted on a printing press, a printing ink and a dampening solution are applied to form a printing ink image, and the printing ink image is formed on a blanket cylinder rotating with the plate cylinder. Transcribe,
Then, printing of one color is performed by transferring the printing ink image on the blanket cylinder onto the printing paper passing between the blanket cylinder and the impression cylinder. After the printing is completed, the printing plate is removed from the plate cylinder, and the blanket on the blanket cylinder is cleaned by the blanket cleaning device, and is ready for the next printing.

Next, the ink jet drawing apparatus 2 will be described. As shown in FIG. 3, the inkjet drawing apparatus 2 used in the plate making apparatus includes an inkjet discharge head 22 and an ink supply unit 24. Ink supply unit 2
Reference numeral 4 further includes an ink tank 25, an ink supply device 26, and an ink density control unit 29. The ink tank 25 includes a stirring unit 27 and an ink temperature management unit 28. The ink may be circulated in the ejection head 22, and in this case, the ink supply unit 24 also has a recovery circulation function. Stirring means 27
Reduces the precipitation and aggregation of the solid components of the ink, thereby reducing the necessity of cleaning the ink tank 25. As the stirring means 27, a rotary blade, an ultrasonic vibrator, and a circulation pump can be used, and these are used or in combination. The ink temperature management means 28 is arranged such that a high-quality image can be stably formed without a change in the physical properties of the ink due to a change in the surrounding temperature and a change in the dot diameter. As the ink temperature control means, a heater, a heating element such as a Peltier element, or a cooling element is arranged in the ink tank 25 together with the stirring means 27 so as to keep the temperature distribution in the ink tank 25 constant, and a temperature sensor, for example, A known method such as control using a thermostat or the like can be used.
The temperature of the ink in the ink tank 27 is 15 ° C. or more and 60 ° C.
C. or less, more preferably 20.degree. C. or more and 50.degree. C. or less. Further, the stirring means for keeping the temperature distribution in the ink tank 25 constant may be shared with the stirring means for suppressing the precipitation and aggregation of the solid components of the ink.

In addition, the plate making apparatus preferably has an ink density control means 29 in order to perform high-quality drawing. As a result, it is possible to effectively suppress the occurrence of bleeding on the plate due to a decrease in the solid concentration in the ink, the jump or blur of the printed image, or the change in the dot diameter on the plate due to the increase in the solid concentration. The ink density is measured by optical detection, physical property measurement such as conductivity measurement, viscosity measurement, or the like, or management based on the number of drawn images. When performing management by physical property measurement, an optical detector, a conductivity measuring instrument, and a viscosity measuring instrument are provided alone or in combination in the ink tank 25 or the ink flow path, and drawing is performed by an output signal thereof. When the management is performed by the number of sheets, the supply of the liquid from the replenishment concentrated ink tank or the dilution ink carrier tank (not shown) to the ink tank 25 is controlled based on the number of plate making and the frequency.

As described above, the image data calculation control unit 21 calculates the input image data, and controls the head separation / contact device 31,
Alternatively, in addition to moving the ejection head 22 by the head sub-scanning means 32, a timing pulse from the encoder 30 provided on the drum 11 or the cap stun roller is taken in, and the ejection head 22 is driven according to the timing pulse. Thereby, the position accuracy can be improved.

The plate making apparatus of the present invention is provided with an abnormality detecting means for detecting an abnormality which hinders image formation.
Hereinafter, the detection device 100 according to the present invention will be described in detail with reference to FIGS. The detection device 100 has a purpose of detecting foreign matter adhesion to a discharge head, detecting dust, detecting vibration, and the like. Among them, regarding the detection of foreign matter adhesion to the ejection head, abnormal current, image quality defect, and meniscus shape abnormality to the ejection head are detected, thereby stopping the drawing operation and / or activating the ejection head cleaning means described later. . For example, as shown in FIG.
When dust adheres to 2, the discharge gap is short-circuited or shortened,
An abnormally large current flows than the normal head current. Therefore, in order to detect an abnormal current to the ejection head 22, a current i flowing through the ejection head is detected by a current detection circuit 111, and an electric signal is converted into a digital signal by a signal processing circuit 112 and sent to the CPU 110. CPU
The reference numeral 110 compares the received digital signal with a reference value in the memory 113, and if the comparison result is out of the allowable range, activates the drawing stop means 117 and / or the cleaning means 118.

As a method of detecting the abnormal meniscus shape,
For example, the shape of the meniscus M formed by the discharge head 22 and the printing ink by capillary action is photographed by a CCD camera 1141 provided near the discharge head, and the photographed image is processed by the image processing circuit 115 and the CPU 110 to automatically execute the processing. The shape of the meniscus M is measured, and this shape is compared with the reference shape of the meniscus M in the memory 113 by the CPU 11.
0 makes the comparison. If no dust adheres to the ejection head 22, the CCD camera 1141 displays a correct meniscus shape.
The camera 1141 captures a distorted shape, and the CPU 1
As a result of the comparison of 10, if the distorted shape is out of the allowable range, the CPU 110 operates the drawing stop means 117 and / or the cleaning means 118.

The method of detecting an image quality defect is essentially the same as the method of detecting an abnormal meniscus shape. That is, the drawn image G is photographed by a CCD camera 1142 provided in the vicinity of the image, the photographed image is converted into a digital signal by an image processing circuit 115, and given to the CPU 110.
0 compares this signal data with the reference data of the image in the memory 113, and when the image data is out of a certain allowable range, the CPU 110 operates the drawing stop means 117 and / or the cleaning means 118. In addition, when the pause state continues for a long time, the cleaning means is preferably operated.

Among the detection means, regarding dust detection, dust adhering to the plate material or dust flying in the machine is detected.
As the detection means, various methods such as optical detection or weight detection of filtered dust are used, but an optical detection method is preferably used. For example, as shown in FIG. 5, a plurality of pairs of light-emitting elements and light-receiving elements 1221-1231, 1222-1232 are provided on a plate material from which dust is to be detected (A) or in a place where dust easily flies in the machine (B). Is arranged. The light emitting elements 1221 and 1222 are LEDs, which are connected to the LED driver 121.
Reference numeral 21 denotes the light emitting element 1 according to the control from the CPU 120.
221 and 1222 are caused to emit light. On the other hand, the light receiving element 123
Reference numerals 1 and 1232 denote phototransistors, which are connected to photoelectric conversion circuits 1241 and 1242, respectively. These light receiving elements 1231 and 1232 are
When the light emitted from the photoelectric conversion circuit 1222 is received,
At 41 and 1242, the optical signal is converted into an electric signal and output to the signal processing circuit 125. This signal processing circuit 125
Converts the electrical signals from the first and second light receiving elements 1231 and 1232 into digital signals and sends them to the CPU 120. The CPU 120 compares the received digital signal with a reference value in the memory 126, and if the comparison result is outside the allowable range, activates the drawing stop means 127 and / or the cleaning means 128.

Next, the ejection head 22 will be described with reference to FIGS.
2 will be described. However, the content of the present invention is not limited to the following.

FIGS. 6 and 7 show an example of the discharge head provided in the ink jet drawing apparatus. Discharge head 22
Has a slit sandwiched between an upper unit 221 and a lower unit 222 made of an insulating base material, the tip of which is a discharge slit 22a, and a discharge electrode 22b is arranged in the slit. Is supplied to the inside of the slit.
Examples of the insulating substrate include plastic, glass,
Ceramics and the like can be applied. Also, the discharge electrode 22b
Is vacuum-evaporated, sputtered, or electrolessly plated with a conductive material such as aluminum, nickel, chromium, gold, and platinum on the lower unit 222 made of an insulating base material.
A photoresist is applied thereon, the photoresist is exposed through a mask of a predetermined electrode pattern, and the photoresist is exposed and developed to form a photoresist pattern of the discharge electrode 22b, and then the etching pattern is etched or mechanically removed. Or a known method such as a method of combining them.

In the ejection head 22, a voltage is applied to the ejection electrode 22b in accordance with a digital signal of image pattern information. As shown in FIG. 6, a drum 11 which is a counter electrode is provided so as to face the discharge electrode 22b.
The plate material 9 is provided on the drum 11 serving as a counter electrode. By applying a voltage, a circuit is formed between the discharge electrode 22b and the drum 11 serving as a counter electrode, and the head 22
The oil-based ink 23 is ejected from the ejection slit 22a, and an image is formed on the plate material 9 provided on the drum 11 serving as a counter electrode.

The width of the discharge electrode 22b is preferably as narrow as possible in order to form a high quality image. Specific numerical values vary depending on conditions such as the applied voltage and the physical properties of the ink, but are usually used in the range of the tip width of 5 to 100 μm. For example, the discharge electrode 22b having a 20 μm wide tip
The distance between the discharge electrode 22b and the drum 11 serving as the counter electrode is set to 1.0 mm, and a voltage of 3 KV is applied between the electrodes for 0.1 millisecond to form a 40 μm dot on the plate material 9.
Can be formed on.

FIGS. 8 and 9 are a schematic cross-sectional view and a schematic front view, respectively, showing the vicinity of the ink discharge portion of another example of the discharge head. In the figure, reference numeral 22 denotes a discharge head, which has a first insulating base material 33 having a gradually decreasing shape. A second insulating base material 34 is provided on the first insulating base material 33 so as to be spaced apart and opposed to the first insulating base material 33, and a slope portion 35 is formed at the tip of the second insulating base material 34. The first and second insulating base materials are made of, for example, plastic, glass, ceramics, or the like. A plurality of ejection electrodes 22b are provided on an upper surface portion 36 of the second insulating base material 34, which forms an acute angle with the slope portion 35, as an electrostatic field forming means for forming an electrostatic field in the ejection portion. The tips of the plurality of ejection electrodes 22 b are extended to near the tips of the upper surface portion 36, and the tips are connected to the first insulating base 33.
It projects more forward than it forms the discharge part. An ink inflow path 37 is formed between the first and second insulating bases 33 and 34 as a means for supplying the ink 23 to the ejection section. An ink recovery path 38 is formed. The discharge electrode 22b is
Using a conductive material such as aluminum, nickel, chromium, gold, and platinum on the second insulating base material 34, as described above,
It is formed by a known method. The individual electrodes 22b are configured to be electrically insulated from each other.

The amount by which the tip of the discharge electrode 22b projects from the tip of the insulating base material 33 is preferably 2 mm or less. The reason that this protrusion amount is preferable in the above range is that if the protrusion amount is too large, the ink meniscus does not reach the tip of the discharge unit,
This is because the ejection becomes difficult and the recording frequency decreases. The space between the first and second insulating bases 33 and 34 is preferably in the range of 0.1 to 3 mm. The reason that this space is preferable in the above range is that if the space is too narrow, it becomes difficult to supply ink and it becomes difficult to discharge, or the recording frequency is lowered, and if the space is too wide, the meniscus is not stable. This is because the ejection becomes unstable.

The ejection electrode 22b is connected to the image data calculation control unit 21. When recording is performed, a voltage is applied to the ejection electrode based on the image information, whereby the ink on the ejection electrode is ejected. Drawing is performed on a plate material (not shown) arranged oppositely. The direction opposite to the ink droplet ejection direction of the ink inflow path 37 is connected to an ink feeding unit of an ink supply device (not shown). The second insulating substrate 3
A backing 39 is provided on the surface opposite to the ejection electrode forming surface of No. 4 so as to be spaced apart and opposed, and an ink recovery path 38 is provided between the two. The space of the ink recovery path 38 is 0.1
mm or more is desirable. The reason why this space is preferable in the above range is that if the space is too narrow, it becomes difficult to collect the ink, which may cause ink leakage. The ink recovery path 38 is connected to an ink recovery means of an ink supply device (not shown).

When a uniform ink flow on the ejection section is required, a groove 40 may be provided between the ejection section and the ink recovery section. FIG. 9 is a schematic front view of the vicinity of the ink ejection portion of the ejection head.
A plurality of grooves 40 are provided toward 8. This groove 4
A plurality of inks 0 are arranged in the arrangement direction of the ejection electrodes 22b, and a certain amount of ink near the tip of the ejection electrode is guided from the opening on the ejection electrode 22b side by a capillary force according to the opening diameter. Is discharged to the ink recovery path 38. Therefore, it has a function of forming an ink flow having a constant liquid thickness near the tip of the discharge electrode. The shape of the groove 40 may be any range as long as the capillary force acts, and particularly preferably, the width is 10 to 200 μm and the depth is 10 to 300 μm.
It is in the range of μm. The necessary number of grooves 40 are provided so that a uniform ink flow can be formed over the entire surface of the ejection head.

The width of the discharge electrode 22b is preferably as narrow as possible in order to form a high quality image. Specific numerical values vary depending on conditions such as applied voltage and ink physical properties, but are usually used in a range of a tip width of 5 to 100 μm.

Another example of the ejection head used to carry out the present invention is shown in FIGS. FIG. 10 is a schematic view showing only a part of the head for explanation. As shown in FIG. 10, the ejection head 22 has a head main body 41 and a meniscus regulating plate 42 made of an insulating material such as plastic, ceramic, or glass. , 42 '. In the drawing, reference numeral 22b denotes an ejection electrode for applying a voltage to form an electrostatic field in the ejection portion. Further, the head main body will be described in detail with reference to FIG. 11 in which the regulation plates 42 and 42 ′ have been removed from the ejection head 22.

The head main body 41 is provided with a plurality of ink grooves 43 for circulating ink perpendicular to the edge of the head main body. The shape of the ink groove 43 may be set in a range where the capillary force acts so that a uniform ink flow can be formed, and particularly preferably, the width is 10 to 200 μm.
m, the depth is 10 to 300 μm. The ejection electrode 22b is provided inside the ink groove 43. The discharge electrode 122b is formed on the head body 40 made of an insulating material by using a conductive material such as aluminum, nickel, chromium, gold, or platinum by a known method similar to that of the above-described apparatus embodiment. It may be arranged on the entire surface inside the groove 43,
It may be formed only in a part. The discharge electrodes are electrically isolated. Two adjacent ink grooves form one cell, and ejection parts 45 and 45 'are provided at the end of the partition wall 44 at the center thereof. In the discharge portions 45 and 45 ', the partition walls are thinner than the other partition portions 44 and are sharpened. Such a head body is manufactured by a known method such as machining, etching, or molding of an insulating material block. The thickness of the partition wall at the discharge portion is preferably 5 to 100 μm, and the radius of curvature of the sharpened tip is preferably 5 to 50 μm.
The tip of the discharge section may be slightly chamfered, such as 45 '. Although only two cells are shown in the figure,
The cells are partitioned by a partition wall 46, and the front end portion 47 is chamfered so as to be retracted from the discharge portions 45 and 45 '. The ink is supplied to the ejection head from the direction I through an ink groove by an ink feeding means of an ink supply device (not shown), and the ink is supplied to the ejection unit. Further, surplus ink is collected in the O direction by an ink collecting means (not shown), and as a result, fresh ink is always supplied to the ejection unit. In this state, a voltage is applied to a discharge electrode (not shown) having a plate material on the surface thereof in accordance with image information in accordance with image information. An image is formed on the material.

Another embodiment of the discharge head will be described with reference to FIG. As shown in FIG. 12, the discharge head 22 has a pair of substantially rectangular plate-shaped support members 50 and 50 '. These support members 50, 50 'are made of a plate-like plastic, glass, ceramic or the like having a thickness of 1 to 10 mm having an insulating property, and one surface of each is parallel to each other according to the recording resolution. Each of the grooves 51, 5 'formed with a plurality of elongated rectangular grooves 51, 51' is formed.
1 'is preferably in the range of 10 to 200 μm in width and 10 to 300 μm in depth, and the discharge electrode 22b is formed entirely or partially inside. As described above, by forming a plurality of structures 51, 51 'on one surface of the support members 50, 50', a plurality of rectangular partition walls 52 are inevitably provided between the structures 51. Each support member 50, 50 '
Are combined so that the surfaces on which the grooves 51 and 51 'are not formed face each other. That is, the ejection head 22 has a plurality of grooves on the outer peripheral surface for flowing ink.
Grooves 51, 51 'formed in each support member 50, 50'
Are connected in a one-to-one correspondence via a rectangular portion 54 of the ejection head 22, and the rectangular portion 54 to which each groove is connected is a predetermined distance (50 to 500 μm) from the upper end 53 of the ejection head 22.
m) has receded. That is, on both sides of each rectangular portion 54, the upper end 55 of each partition 52 of each support member 50, 50 '.
Are provided so as to protrude from the rectangular portion 54. A guide protrusion 56 made of an insulating material as described above is provided so as to protrude from each rectangular portion 54 to form a discharge portion.

When the ink is circulated through the ejection head 22 configured as described above, the ink is supplied to each rectangular portion 54 through each groove 51 formed on the outer peripheral surface of one support member 50, and the ink is supplied to the opposite side. Each groove 5 formed in the supporting member 50 '
Discharge via 1 '. In this case, the ejection head 22 is inclined at a predetermined angle to enable smooth ink distribution. That is, the ejection head 22 is inclined such that the ink supply side (support member 50) is located above and the ink discharge side (support member 50 ') is located below.
As described above, when the ink is circulated through the ejection head 22,
The ink passing through each rectangular portion 54 gets wet along each protrusion 56, and an ink meniscus is formed near the rectangular portion 54 and the protrusion 56. Then, in a state where independent ink meniscuses are formed in the respective rectangular portions 54,
Ink is ejected from the ejection unit to apply a voltage to the ejection electrode 22b based on image information to a drum (not shown) holding the plate material on the surface thereof, and the ink is ejected from the ejection unit onto the plate material. An image is formed. By providing a cover for covering the groove on the outer peripheral surface of each support member 50, 50 ', a pipe-shaped ink flow path is formed along the outer peripheral surface of each support member 50, 50'. May be forcibly circulated. In this case, it is not necessary to tilt the ejection head 22.

The ejection head 22 described above with reference to FIGS. 6 to 12 can include a maintenance device such as a cleaning means as required. For example, if the pause state continues or if a problem occurs in image quality, the tip of the ejection head is brushed with a flexible brush, brush, cloth, or the like, circulates only the ink solvent, supplies only the ink solvent, Alternatively, a good drawing state can be maintained by performing means such as sucking the discharge unit while circulating the ink alone or in combination. In order to prevent the ink from sticking, it is effective to cool the head and suppress evaporation of the ink solvent. If the contamination is further severe, the ink is forcibly sucked from the ejection section, the jet of air, ink, or ink solvent is forcibly injected from the ink flow path, or the ultrasonic wave is applied while the head is immersed in the ink solvent. Is also effective, and these methods can be used alone or in combination.

Next, the plate material (printing plate) used in the present invention will be described. Examples of the printing original plate include metal plates such as aluminum and chrome-plated steel plates. In particular, an aluminum plate having excellent surface water retention and abrasion resistance by graining and anodizing is preferable. As an inexpensive plate material, a plate material provided with an image receiving layer on a water-resistant support such as water-resistant paper, plastic film, or paper laminated with plastic can be used. The thickness of the plate material is suitably in the range of 100 to 300 μm, and the thickness of the image receiving layer provided is suitably in the range of 5 to 30 μm.

As the image receiving layer, a hydrophilic layer comprising an inorganic pigment and a binder, or a layer which can be made hydrophilic by a desensitizing treatment can be used.

As the inorganic pigment used in the hydrophilic image receiving layer, clay, silica, calcium carbonate, zinc oxide, aluminum oxide, barium sulfate and the like can be used. Further, as a binder, polyvinyl alcohol, starch,
Hydrophilic binders such as carboxymethylcellulose, hydroxyethylcellulose, casein, gelatin, polyacrylate, polyvinylpyrrolidone, and polymethylether-maleic anhydride copolymer can be used. If necessary, a melamine formalin resin, a urea formalin resin, or another crosslinking agent for imparting water resistance may be added.

On the other hand, examples of the image receiving layer used after desensitization treatment include a layer using zinc oxide and a hydrophobic binder.

Zinc oxide to be used in the present invention may be, for example, zinc oxide, zinc white or zinc oxide, as described in “Pigment Handbook”, edited by Japan Pigment Technical Association, p. 319, Seibundo Co., Ltd. (1968). Any of those commercially available as wet zinc white or activated zinc white may be used. That is, zinc oxide includes, as dry methods, French methods (indirect methods), American methods (direct methods) and wet methods, depending on the starting materials and the production method. For example, Shodo Chemical Co., Ltd., Sakai Chemical Co., Ltd. ), Hakusui Chemical Co., Ltd., Honjo Chemical Co., Ltd., Toho Zinc Co., Ltd., Mitsui Kinzoku Kogyo Co., Ltd., and the like.

Examples of the resin used as the binder include styrene copolymer, styrene-methacrylate copolymer, methacrylate copolymer, acrylate copolymer, vinyl acetate copolymer, polyvinyl butyral, and alkyd resin. , Epoxy resin, epoxy ester resin, polyester resin, polyurethane resin and the like. These resins may be used alone or in combination of two or more. The content of the resin in the image receiving layer is preferably from 9/91 to 20/80 in terms of resin / zinc oxide weight ratio.

Desensitization of zinc oxide is carried out by a conventional method using a desensitizing solution. Conventionally, as this type of desensitizing solution, a cyanide compound containing a ferrocyanide salt or a ferricyan salt as a main component has been used. Containing treatment solution, ammine cobalt complex,
Phytic acid and its derivatives, cyanogen-free treatment liquid containing guanidine derivative as a main component, treatment liquid containing inorganic or organic acid that forms chelate with zinc ions as a main component,
Alternatively, a treatment liquid containing a water-soluble polymer is known. For example, as a cyanide-containing treatment liquid, JP-B-44-9045 and JP-B-46-39403;
-76101, 57-107889, 54-1
No. 17,201, and the like.

The surface of the plate material opposite to the image receiving layer is
The Beck smoothness is preferably in the range of 150 to 700 (sec / 10 cc). As a result, the formed printing plate does not shift or slip on the plate cylinder even during printing,
Good printing is performed.

The Beck smoothness can be measured by a Beck smoothness tester. A Beck Smoothness Tester is a tester in which a test piece is placed at a constant pressure (1 kgf / cm ² (9.8 N) on a highly smooth finished circular glass plate with a hole in the center.
/ Cm ² )) to measure the time required for a fixed amount (10 cc) of air to pass between the glass surface and the test piece under reduced pressure.

The oil-based ink used in the present invention will be described below. The oil-based ink used in the present invention is obtained by dispersing solid and hydrophobic resin particles at least at room temperature in a non-aqueous solvent having a specific electric resistance of 10 ⁹ Ωcm or more and a dielectric constant of 3.5 or less.

The specific electric resistance used in the present invention is 10 ⁹ Ωcm.
As the nonaqueous solvent having a dielectric constant of 3.5 or less, preferably a linear or branched aliphatic hydrocarbon, alicyclic hydrocarbon, or aromatic hydrocarbon, and a halogen-substituted product of these hydrocarbons are used. is there. For example, hexane, heptane,
Octane, isooctane, decane, isodecane, decalin, nonane, dodecane, indodecane, cyclohexane, cyclooctane, cyclodecane, benzene, toluene, xylene, mesitylene, isoper C, isoper E, isoper G, isoper H, isoper L (isoper: exon , Shelsol 70, Shelsol 71 (Shellsol: trade name of Shell Oil), Amsco OMS, Amsco 460 solvent (Amsco: trade name of Spirits), silicone oil, etc., alone or as a mixture. Used. The upper limit of the specific electric resistance of such a non-aqueous solvent is about 10 ¹⁶ Ωcm, and the lower limit of the dielectric constant is about 1.9.

The reason why the electric resistance of the non-aqueous solvent used is within the above range is that when the electric resistance is low, it is difficult for the resin particles and the like to concentrate, and sufficient printing durability cannot be obtained. The reason for setting the above range is that when the dielectric constant becomes higher, the electric field in the ink is relaxed due to the polarization of the solvent, whereby the ejection of the ink tends to be deteriorated.

The resin particles dispersed in the above non-aqueous solvent may be any hydrophobic resin particles which are solid at a temperature of 35 ° C. or lower and have a good affinity for the non-aqueous solvent. Glass transition point is -5 ° C to 110 ° C or softening point 33 ° C
The resin (P) having a glass transition point of 10 to 100 ° C or a softening point of 38 to 1 ° C is more preferable.
20 ° C., more preferably 15 ° C.
80 ° C or a softening point of 38 ° C to 100 ° C.

By using such a resin having a glass transition point or softening point, the affinity between the surface of the image receiving layer of the printing original plate and the resin particles is increased, and the bonding between the resin particles on the printing original plate is increased. Therefore, the adhesion between the image portion and the image receiving layer is improved, and the printing durability is improved. On the other hand, regardless of whether the glass transition point or softening point is low or high, the affinity between the image receiving surface and the resin particles is reduced, or the bonding between the resin particles is weakened.

The weight average molecular weight Mw of the resin (P) is 1 ×
10 ³ to 1 × 10 ⁶ , preferably 5 × 10 ³ to 8
× 10 ⁵ , more preferably 1 × 10 ^{4 to} 5 × 10 ⁵ .

Specific examples of the resin (P) include:
Olefin polymers and copolymers (eg, polyethylene, polypropylene, polyisobutylene, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer,
Ethylene-methacrylate copolymer, ethylene-methacrylic acid copolymer), vinyl chloride polymer and copolymer (eg, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, etc.), vinylidene chloride copolymer, alkane Vinyl acid polymers and copolymers, allyl alkanoate polymers and copolymers, polymers and copolymers of styrene and its derivatives (for example, butadiene-styrene copolymer, isoprene-styrene copolymer, styrene-methacrylate copolymer) Polymer, styrene-acrylate copolymer, etc.), acrylonitrile copolymer, methacrylonitrile copolymer, alkyl vinyl ether copolymer, acrylate ester polymer and copolymer, methacrylate ester polymer and copolymer, Itaconic acid diester polymer and copolymer, anhydrous maleic Acid copolymers, acrylamide copolymers, methacrylamide copolymers, Funinoru resin,
Alkyd resin, polycarbonate resin, ketone resin, polyester resin, silicone resin, amide resin, hydroxyl and carboxyl group-modified polyester resin, butyral resin, polyvinyl acetal resin, urethane resin, rosin resin, hydrogenated rosin resin, petroleum resin, hydrogenated Petroleum resin, maleic acid resin, terpene resin, hydrogenated terpene resin, cumarone-indene resin, cyclized rubber-methacrylate copolymer, cyclized rubber-acrylate copolymer, heterocycle containing no nitrogen atom Copolymers (for example, heterocycles such as a furan ring, a tetrahydrofuran ring, a thiophene ring, a dioxane ring, a dioxofuran ring, a lactone ring, a benzofuran ring, a benzothiophene ring, and a 1,3-dioxetane ring), and an epoxy resin. Can be

The content of the dispersed resin particles in the oil-based ink of the present invention is preferably 0.5 to 20% by weight of the whole ink. If the content is low, it is difficult to obtain affinity between the ink and the surface of the printing original plate, and a good image cannot be obtained, or problems such as reduced printing durability tend to occur. When the number of inks increases, it becomes difficult to obtain a uniform dispersion liquid, and the flow of the ink in the discharge head tends to be uneven, so that stable ink discharge is difficult to obtain.

The oil-based ink used in the present invention preferably contains a coloring material as a coloring component together with the above-described dispersed resin particles, for example, for plate inspection of a plate after plate making.
As the coloring material, any pigments and dyes conventionally used in oil-based ink compositions or liquid developers for electrostatography can be used.

As the pigments, those generally used in the technical field of printing can be used irrespective of inorganic pigments and organic pigments. Specifically, for example, carbon black, cadmium red, molybdenum red, Chrome yellow, cadmium yellow, titanium yellow, chromium oxide, viridian, cobalt green, ultramarine blue, Prussian blue, cobalt blue, azo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, dioxazine pigments, sulene Conventionally known pigments such as pigments, perylene pigments, perinone pigments, thioindigo pigments, quinophthalone pigments, and metal complex pigments can be used without particular limitation.

As the dyes, azo dyes, metal complex dyes,
Naphthol dye, anthraquinone dye, indigo dye,
Oil-soluble dyes such as carbonium dyes, quinone imine dyes, xanthene dyes, aniline dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, naphthoquinone dyes, phthalocyanine dyes and metal phthalocyanine dyes are preferred. These pigments and dyes may be used alone or in an appropriate combination, but are preferably contained in the range of 0.01 to 5% by weight based on the whole ink.

These coloring materials may be dispersed in a non-aqueous solvent as dispersed particles in the non-aqueous solvent separately from the dispersed resin particles, or may be contained in the dispersed resin particles. In the case of containing, pigments and the like are generally coated with the resin material of the dispersed resin particles to obtain resin-coated particles, and dyes and the like are formed by coloring the surface of the dispersed resin particles into colored particles. General.

The resin particles dispersed in the non-aqueous solvent of the present invention, and further including the colored particles, preferably have an average particle size of 0.05 μm to 5 μm. More preferably, it is 0.1 μm to 1.0 μm. This particle size is CAPA-
500 (trade name, manufactured by Horiba, Ltd.).

The non-aqueous dispersion resin particles used in the present invention can be produced by a conventionally known mechanical pulverization method or polymerization granulation method. As the mechanical grinding method,
If necessary, a material to be resin particles is mixed, melted and kneaded, and then directly pulverized by a conventionally known pulverizer to obtain fine particles, a dispersing polymer is used in combination, and a wet disperser (for example, a ball mill, a paint shaker) , Keddy mill, Dyno mill, etc.), a material to be a resin particle component,
A method of kneading a dispersion-assisting polymer (or a coating polymer) in advance to form a kneaded product, pulverizing the mixture, and then dispersing the mixture in the presence of a dispersing polymer may be used. Specifically, a method for producing a paint or a liquid developer for electrostatography can be used. For example, these methods are described in Kenji Ueki, “Flow and paint dispersion of paint”, Kyoritsu Shuppan (1971), Solomon “ Coating Science "Hirokawa Shoten (1969), Yuji Harazaki" Coating Engineering "Asakura Shoten (1971), Yuji Harasaki" Basic Science of Coating "Maki Shoten (1977), etc.

Examples of the polymerization granulation method include a conventionally known non-aqueous dispersion polymerization method. Specifically, Chapter 2 of Soichi Muroi's "Latest Technology of Ultrafine Polymer", CMC Publishing (1991) ), Koichi Nakamura, "Recent Development of Electrophotographic Development System and Toner Materials, Development and Practical Use", Chapter 3, (Nippon Scientific Information Co., Ltd., 1985), KEJ Barrett, "Dispersi
on Polymerization Organic Media "John Wiley (19
75 years).

Usually, a dispersion polymer is used in combination to stabilize the dispersion of the dispersed particles in a non-aqueous solvent. The dispersed polymer contains a repeating unit soluble in a non-aqueous solvent as a main component, and has an average molecular weight of 1 × 10 in weight average molecular weight Mw.
^It is preferably ³ to 1 × 10 ⁶ , more preferably 5 × 10 ³
５5 × 10 ⁵ .

As preferred soluble repeating units of the dispersion polymer used in the present invention, there may be mentioned a polymerization component represented by the following formula (I).

[0106]

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In the general formula (I), X ₁ is —COO
Represents-, -OCO- or -O-. R represents 10 carbon atoms
Represents an alkyl group or an alkenyl group having from 32 to 32, preferably represents an alkyl group or an alkenyl group having from 10 to 22 carbon atoms, and may be linear or branched. It may be. Specifically, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosanyl group, docosanyl group, decenyl group, dodecenyl group, tridecenyl group, hexadecenyl group, octadecenyl group, linolenyl group, and the like. .

A₁And a_TwoAre the same or different
May be a hydrogen atom, a halogen atom (eg, chlorine
Atom, bromine atom, etc.), cyano group, alkyl having 1 to 3 carbon atoms
(For example, methyl group, ethyl group, propyl group, etc.),
-COO-Z₁Or -CH _TwoCOO-Z₁[Z₁Is
An optionally substituted hydrocarbon group having 22 or less carbon atoms (eg,
For example, alkyl group, alkenyl group, aralkyl group, alicyclic
A formula group, an aryl group, etc.).

Among the hydrocarbon groups represented by Z ₁ , preferred hydrocarbon groups include alkyl groups having 1 to 22 carbon atoms which may be substituted (for example, methyl group, ethyl group, propyl group, butyl group, Hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, tridecyl group,
Tetradecyl group, hexadecyl group, octadecyl group, eicosanyl group, docosanyl group, 2-chloroethyl group, 2
-Bromoethyl group, 2-cyanoethyl group, 2-methoxycarbonylethyl group, 2-methoxyethyl group, 3-bromopropyl group and the like, and an optionally substituted alkenyl group having 4 to 18 carbon atoms (for example, 2-methyl- 1-propenyl group, 2-butenyl group, 2-pentenyl group, 3-methyl-
2-pentenyl group, 1-pentenyl group, 1-hexenyl group, 2-hexenyl group, 4-methyl-2-hexenyl group, decenyl group, dodecenyl group, tridecenyl group, hexadecenyl group, octadecenyl group, linolenyl group, etc.),
An aralkyl group having 7 to 12 carbon atoms which may be substituted (for example, benzyl group, phenethyl group, 3-phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group, chlorobenzyl group, bromobenzyl group, methylbenzyl group, An ethylbenzyl group, a methoxybenzyl group, a dimethylbenzyl group, a dimethoxybenzyl group, etc., an alicyclic group having 5 to 8 carbon atoms which may be substituted (for example, cyclohexyl group,
-Cyclohexylethyl group, 2-cyclopentylethyl group and the like, and an optionally substituted aromatic group having 6 to 12 carbon atoms (for example, phenyl group, naphthyl group, tolyl group, xylyl group, propylphenyl group, butylphenyl group) Octylphenyl, dodecylphenyl, methoxyphenyl, ethoxyphenyl, butoxyphenyl, decyloxyphenyl, chlorophenyl, dichlorophenyl, bromophenyl, cyanophenyl, acetylphenyl, methoxycarbonylphenyl, ethoxy Carbonylphenyl group, butoxycarbonylphenyl group, acetamidophenyl group, propionamidophenyl group, dodecylylamidophenyl group, etc.).

In the dispersion polymer, another repeating unit may be contained as a copolymer component together with the repeating unit represented by the general formula (I). Other copolymer components include:
Any compound may be used as long as it is composed of a monomer copolymerizable with a monomer corresponding to the repeating unit of the general formula (I).

The proportion of the polymer component represented by the general formula (I) in the dispersion polymer is preferably at least 50% by weight, more preferably at least 60% by weight. Specific examples of these dispersion polymers include the dispersion stabilizing resin (Q-1) used in Examples, and a commercially available product (Solprene 1205, manufactured by Asahi Kasei Corporation) can also be used.

When the resin (P) particles are produced as a dispersion (latex) or the like, the dispersion polymer is preferably added in advance during the polymerization. When the dispersion polymer is used, the addition amount is 1 to 50 with respect to the resin for particles (P).
% By weight.

The dispersed resin particles and the colored particles (or coloring material particles) in the oil-based ink of the present invention are preferably positively or negatively charged electro-detectable particles. In order to impart an electric detecting property to these particles, it can be achieved by appropriately utilizing a technique of a developer for wet electrophotography. Specifically, the aforementioned "Recent development and practical use of electrophotographic development systems and toner materials", pages 139 to 148, "Basics and Application of Electrophotographic Technology", edited by the Society of Electrophotographic Engineers, pp. 497-505 (Corona, 1988)
Annual), Yuji Harasaki "Electrophotography" 16 (No. 2), 44
The method is performed by using an electric detection material such as a charge control agent described on page (1977) and other additives.

More specifically, for example, British Patent No. 8934
No. 29, No. 934038, No. 11222397,
U.S. Pat. No. 3,900,412, equivalent 4,606,899,
JP-A-60-179751, JP-A-60-185963
And JP-A-2-139651. The charge controlling agent as described above is preferably used in an amount of 0.001 to 1.0 part by weight based on 1000 parts by weight of the dispersion medium as the carrier liquid. If desired, various additives may be added. The upper limit of the total amount of these additives is regulated by the electrical resistance of the oil-based ink. That is, if the specific electric resistance of the ink from which the dispersed particles have been removed is lower than 10 ⁹ Ωcm, it becomes difficult to obtain a high-quality continuous tone image. desirable.

[0115]

The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples. First, a production example of the ink resin particles (PL) will be described.

Production Example 1 of Resin Particles (PL-1) A mixed solution of 10 g of a dispersion stabilizing resin (Q-1) having the following structure, 100 g of vinyl acetate and 384 g of Isopar H was heated to a temperature of 70 ° C. while stirring under a nitrogen stream. did. 2,2'-azobis (isovaleronitrile) as a polymerization initiator
0.8 g (abbreviation AIVN) was added and reacted for 3 hours. Twenty minutes after addition of the initiator, cloudiness occurred and the reaction temperature rose to 88 ° C. Furthermore, 0.5 g of this initiator was added, and after reacting for 2 hours, the temperature was raised to 100 ° C. and the mixture was stirred for 2 hours to distill off unreacted vinyl acetate. After cooling, the mixture was passed through a 200-mesh nylon cloth, and the resulting white dispersion was a latex having a degree of polymerization of 90% and an average particle size of 0.23 μm and having good monodispersity. The particle size was measured with CAPA-500 (manufactured by Horiba, Ltd.).

[0117]

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A part of the white dispersion was centrifuged (rotation speed: 1 × 10 ⁴ rpm, rotation time: 60 minutes), and the precipitated resin particles were collected and dried. Weight average molecular weight of resin particles (Mw: GPC in terms of polystyrene)
Value) was 2 × 10 ⁵ , and the glass transition point (Tg) was 38 ° C.

Example 1 First, an oil-based ink was prepared. <Preparation of oil-based ink (IK-1)> 10 g of dodecyl methacrylate / acrylic acid copolymer (copolymerization ratio: 95/5 by weight), 10 g of nigrosine and Shellsol 7
1 g together with glass beads was placed in a paint shaker (manufactured by Toyo Seiki Co., Ltd.) and dispersed for 4 hours to obtain a fine dispersion of nigrosine. Production example 1 of resin particles for ink
60 g (as a solid content) of the resin particles (PL-1) produced in the above, 2.5 g of the above nigrosine dispersion, FOC-14
00 (Nissan Chemical Co., Ltd., tetradecyl alcohol) 1
A black oil-based ink was prepared by diluting 5 g, and 0.08 g of the octadecene-half-maleic acid octadecylamide copolymer into 1 liter of Isopar G.

Next, 2 liters of the oil-based ink (IK-1) prepared as described above was charged into an ink tank of the ink jet drawing apparatus 2 of the plate making apparatus (see FIGS. 1 and 3). Here, 900 dp shown in FIG.
i, a 64 channel multi-channel head was used. A throwing heater and a stirring blade were provided in the ink tank as ink temperature management means, the ink temperature was set at 30 ° C., and the temperature was controlled with a thermostat while rotating the stirring blade at 30 rpm. Here, the stirring blade was also used as a stirring means for preventing sedimentation and aggregation. Further, the ink flow path is partially transparent, and an LED light emitting element and a light detecting element are arranged with the ink flow path interposed therebetween.
The solid content concentration of 1) was adjusted to be twice), and the concentration was controlled by feeding.

As a plate material, a 0.12 mm-thick aluminum plate subjected to graining and anodic oxidation treatment was mounted with the plate head and plate edge added by a mechanical device provided on a drum of a plate making device. After removing dust from the surface of the plate by suction with an air pump, bring the discharge head close to the plate until the drawing position,
The image data to be made was transmitted to the image data calculation control unit, and the 64-channel ejection head was moved while rotating the drum, thereby ejecting oily ink onto the aluminum plate to form an image. At this time, dust on the plate surface was optically detected, and an air pump suction was performed based on the output to remove dust from the plate material surface. Further, by detecting the meniscus shape at the tip of the head, foreign matter adhesion to the head was monitored, and an acceleration clock was attached to the head and the plate cylinder, and vibration was detected by relative vibration. The tip width of the ejection electrode of the ink jet head was set to 10 μm, and the distance between the head and the plate material was controlled to be 1 mm by the output from the optical gap detecting device. A voltage of 2.5 KV is constantly applied as a bias voltage, and when performing ejection, a pulse voltage of 500 V is further superimposed, and the pulse voltage is reduced from 0.2 milliseconds to 0.05.
Drawing was performed while changing the dot area by changing the area in 256 steps within the range of milliseconds. No drawing failure due to greeting was observed at all, and no image deterioration due to a change in the dot diameter was observed even when the outside air temperature changed or the number of plate making increased, and good plate making was possible.

Further, the image was strengthened by heating with a xenon flash fixing device (light emission intensity 200 J / pulse, manufactured by Ushio Inc.) to produce a printing plate. In order to protect the ink jet head, the ink jet drawing apparatus is retracted by 50 mm from a position close to the drum together with the sub-scanning means.
It was mounted on a plate cylinder of a 66EPZ printing machine and printed.

The obtained printed matter was an extremely clear image without any skipping or blurring in the printed image even after passing 10,000 sheets. In addition, after supplying Isopar G to the head for 10 minutes after the completion of plate making, cleaning by dropping Isopar G from the head opening, the head is stored in a cover filled with vapor of Isopar G. For three months, a printing plate giving good prints could be produced without the need for maintenance work.

Example 2 A 600 dpi full line ink jet head of the type shown in FIG. 6 was arranged in the apparatus shown in FIG. A pump is used for ink circulation, and ink reservoirs are respectively provided between the pump and the ink inflow path of the discharge head, and between the ink recovery path of the discharge head and the ink tank. A heater and the above-mentioned pump were used as temperature control means, the ink temperature was set to 35 ° C., and the temperature was controlled by a thermostat. Here, the circulation pump was also used as a stirring means for preventing precipitation and aggregation. In addition, an electric conductivity measuring device was arranged in the ink flow path, and the density was controlled by diluting the ink or feeding the concentrated ink based on the output signal. The above-described aluminum plate was similarly mounted on a drum of a plate-making apparatus as a plate material. After removing dust on the surface of the plate using a rotating brush made of nylon, the image data to be made is transmitted to the image data arithmetic and control unit, and the plate material is drawn by the full line head while transporting the plate using the capstan roller. An image was formed by discharging oil-based ink onto the aluminum plate. At this time, dust on the plate surface was optically detected, and the output thereof was used to remove dust on the surface of the plate material using a rotating nylon brush. Also, by detecting the abnormal current of the head, foreign matter adhesion to the head is monitored, and an accelerometer is attached to the head and the plate cylinder. Vibration is detected based on the relative vibration. did. As a result, no defective drawing or the like due to dust was observed at all, and no image deterioration due to a change in dot diameter or the like was observed even when the outside air temperature was changed or the number of plate making was increased, and good plate making was possible. On the other hand, as a result of forcibly applying vibration to the apparatus, voltage application to the ejection head was temporarily stopped, drawing was stopped, but drawing was restarted as soon as the vibration stopped.
Good plate making was done. Then, heat roll (300W
Halogen lamp included Teflon seal silicone rubber roller) Heated by fixing (pressure: 3 kgf / cm ² (2
9.4 N / cm ² )) The image was solidified and a printing plate was prepared.

When printing was carried out on the prepressed plate in the same manner as in Example 1, the printed image was extremely clear without any skipping or blurring even after passing through 10,000 sheets. In addition, after circulating Isopar G in the head after the completion of plate making, cleaning was performed by bringing the nonwoven fabric containing Isopar G into contact with the tip of the head and performing cleaning for three months without the need for maintenance work. The printing plate to be given could be made. Furthermore,
When a 600 dpi full line inkjet head of the type shown in FIGS. 8 and 10 was used in place of the inkjet head of the type shown in FIG. 6, good results were obtained in the same manner as described above.

Example 3 In place of the aluminum plate of Example 1, a plate material provided with an image receiving layer which can be made hydrophilic by a desensitizing treatment was used on the surface shown below. Non-image area is hydrophilized using a surface treatment device, the plate material conductive layer is grounded by contact with a conductive leaf spring (made of phosphor bronze) at the time of drawing, and fixing is performed by applying hot air to the plate material. Is Example 1
The same operation was performed.

Using a high-quality paper having a basis weight of 100 g / m ² as a substrate, a polyethylene film having a thickness of 20 μm was laminated on both surfaces of the substrate to form a water-resistant paper support. The layer coating is applied on one side, and after drying, the applied amount is 10 g / m ² ,
Further, the dispersion A was dried thereon and dried at a coating amount of 15 g /
An image receiving layer was provided so as to obtain m ² , thereby obtaining a plate material.

Paint for conductive layer; carbon black (30
% Aqueous dispersion), 5.4 parts, clay (50% aqueous dispersion) 5
4.6 parts, SBR latex (solid content 50%, Tg25
C) 36 parts and melamine resin (solid content 80%, Sumiretz Resin SR-613) 4 parts were mixed, and the total solid content was 2
Water was added so as to be 5% to obtain a paint.

Dispersion A: 100 g of dry zinc oxide, 3 g of binder resin (B-1) having the following structure, and binder resin (B-2) 1
A mixture of 7 g, 0.15 g of benzoic acid and 155 g of toluene was wet-dispersed with a homogenizer (manufactured by Nippon Seiki Co., Ltd.).
For 8 minutes at 6,000 rpm.

[0130]

Embedded image

When fixing was performed by blowing hot air onto the plate material, blisters were generated. Therefore, the fixing was performed by gradually increasing the supply power to the heater used for the hot air, or by gradually decreasing the rotation speed of the drum from high speed to low speed without changing the supply power.
As a result, no blister was generated, and the printed matter obtained by printing the printing plate was an extremely clear image without any skipping or blurring in the printed image even when the number of sheets passed 5,000.

[0132]

According to the present invention, it is possible to prepare a printing plate capable of printing a large number of prints of clear images. In addition, printing plates that directly correspond to digital image data can be created with stable high image quality.
Inexpensive and high-speed lithographic printing becomes possible.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram schematically showing one example of a plate making apparatus used in the present invention.

FIG. 2 is an overall configuration diagram schematically showing another example of the plate making apparatus used in the present invention.

FIG. 3 is a configuration diagram schematically illustrating an example of a drawing unit of the plate making apparatus used in the present invention.

FIG. 4 is a block diagram illustrating a detection unit that detects an ejection head meniscus abnormality and the like.

FIG. 5 is a block diagram illustrating a detecting unit that detects dust and the like.

FIG. 6 is a schematic configuration diagram showing an example of an ejection head provided in an ink jet drawing apparatus used in the present invention.

FIG. 7 is a schematic cross-sectional view of the vicinity of an ink ejection unit in FIG. 6;

FIG. 8 is a schematic cross-sectional view of an example of another ejection head provided in the inkjet drawing apparatus used in the present invention, in the vicinity of an ink ejection section.

FIG. 9 is a schematic front view of the vicinity of the ink discharge unit in FIG. 8;

FIG. 10 is a schematic configuration diagram illustrating a main part of an example of another ejection head provided in the inkjet drawing apparatus used in the present invention.

11 is a schematic configuration diagram of a head obtained by removing a regulating plate from the ejection head of FIG.

FIG. 12 is a schematic configuration diagram showing a main part of an example of another ejection head provided in the inkjet drawing apparatus used in the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 plate making device 2 ink jet drawing device 5 fixing device 6 plate surface desensitizing device 7 plate material automatic plate feeding device 8 plate material automatic plate discharging device 9 plate material (printing plate) 10 dust removing means 11 drum 12 capstan roller 13 grounding means 21 Image data calculation control unit 22 Discharge head 221 Upper unit 222 Lower unit 22a Discharge slit 22b Discharge electrode 23 Oil-based ink 24 Ink supply unit 25 Ink tank 26 Ink supply device 27 Stirring unit 28 Ink temperature management unit 29 Ink density control unit 30 Encoder 31 Head separation / contact device 32 Head sub-scanning means 33 First insulating substrate 34 Second insulating substrate 35 Slope of second insulating substrate 36 Upper surface of second insulating substrate 37 Inflow of ink Road 38 Ink recovery path 39 Backing 40 Groove 41 Head book 42, 42 'Meniscus regulating plate 43 Ink groove 44 Partition wall 45, 45' Ejection part 46 Partition wall 47 Partition end part 50, 50 'Support member 51, 51' Groove 52 Partition wall 53 Upper end part 54 Rectangular part 55 Upper end of partition 56 Guide projection REFERENCE SIGNS LIST 100 detection device 110 CPU 111 current detection circuit 112 signal processing circuit 113 memory 117 drawing stop unit 118 cleaning unit 1141, 1142 CCD camera 1221, 1222 light emitting element (LED) 1231, 1232 light receiving element (phototransistor) 120 CPU 121 LED driver 1241 , 1242 photoelectric conversion circuit 125 signal processing circuit 126 memory 127 drawing stop means 128 cleaning means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuo Ishii 4,000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture Inside Fujisha Shin Film Co., Ltd. Incorporated F term (reference) 2C056 EB29 EB44 2C061 AQ05 AS11 HJ06 HK11 HV44 2H084 AA40 2H086 BA02 BA54 BA59 BA60

Claims (21)

[Claims] 1. An image is formed directly on a plate material by an electrostatic ink jet method in which an oil-based ink is discharged using an electrostatic field based on a signal of image data, and the image is fixed to form a printing plate. A plate making method comprising: stopping image formation and / or removing the cause of an abnormality when an abnormality occurs. 2. The method according to claim 1, wherein the oil-based ink has a specific electric resistance value of 10.
The plate making method according to claim 1, wherein solid and hydrophobic resin particles are dispersed at least at room temperature in a non-aqueous solvent having a dielectric constant of ⁹ Ωcm or more and 3.5 or less. 3. An image forming means for forming an image directly on a plate material based on a signal of image data, comprising: an ink jet drawing device for discharging oil-based ink from a discharge head using an electrostatic field. An image fixing device for fixing a formed image to obtain a printing plate, comprising: an abnormality detecting unit and / or an abnormal cause removing unit; and at least temporarily, based on an output from the abnormality detecting unit. A plate making apparatus wherein the operation of the image forming means is stopped and / or the abnormality cause removing means is operated. 4. The plate making apparatus according to claim 3, further comprising a recording head foreign matter adhesion detecting device for detecting foreign matter adhesion to a recording head of said ink jet drawing apparatus as said abnormality detecting means. 5. A plate making apparatus according to claim 3, further comprising a dust detecting device for detecting dust in said plate making apparatus and / or on said plate material, as said abnormality detecting means. 6. A plate making apparatus according to claim 3, further comprising a vibration detecting device for detecting vibration of said plate making device and / or said recording head as said abnormality detecting means. 7. The oil-based ink has a specific electric resistance of 10
The plate-making apparatus according to any one of claims 3 to 6, wherein solid and hydrophobic resin particles are dispersed at least at room temperature in a non-aqueous solvent having a resistivity of ⁹ Ωcm or more and a dielectric constant of 3.5 or less. 8. The plate making apparatus according to claim 3, wherein said image fixing means has a heating means using a heat roller and / or an infrared lamp, a halogen lamp or a xenon flash lamp. 9. The plate making apparatus according to claim 8, wherein the heating unit is arranged and / or controlled so as to gradually increase the temperature of the plate material when fixing the image. 10. The plate making apparatus according to claim 3, wherein at the time of drawing on the plate material, main scanning is performed by rotating a drum on which the plate material is mounted. 11. The plate-making apparatus according to claim 10, wherein the ejection head comprises a single-channel head or a multi-channel head, and performs sub-scanning by moving the ejection head in the axial direction of the drum. 12. The sub-scanning device according to claim 3, wherein at the time of drawing on the plate material, sub-scanning is performed by nipping and moving the plate material by at least a pair of capstan rollers.
A plate-making apparatus according to the item. 13. The plate-making method according to claim 12, wherein the discharge head is a single-channel head or a multi-channel head, and performs main scanning by moving the discharge head in a direction orthogonal to a direction in which the plate material travels. apparatus. 14. The discharge head comprises a full line head having a length substantially equal to a width of the plate material.
Or the plate making apparatus according to 12. 15. The plate making apparatus according to claim 3, wherein the ink jet drawing apparatus has an ink supply unit that supplies the oil-based ink to the discharge head. 16. The plate making apparatus according to claim 15, further comprising an ink collecting means for collecting the oil-based ink from the ejection head, and performing ink circulation. 17. The plate making apparatus according to claim 3, further comprising dust removing means for removing dust existing on the surface of the plate material before and / or during drawing on the plate material. . 18. The plate making apparatus according to claim 3, wherein the ink jet drawing apparatus has a stirring means for stirring the oil-based ink in an ink tank storing the oil-based ink. 19. The ink-jet drawing apparatus according to claim 3, further comprising an ink temperature management unit for managing a temperature of the oil-based ink in an ink tank storing the oil-based ink.
19. The plate-making apparatus according to any one of claims 18 to 18. 20. A plate making apparatus according to claim 3, wherein said ink jet drawing apparatus has an ink density control means for controlling the density of said oil-based ink. 21. The plate making apparatus according to claim 3, further comprising a cleaning unit for cleaning the discharge head.