JP2003326667A - On-board drawing planographic printing method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-board drawing planographic printing method and an apparatus dispensing with developing treatment, capable of performing on- board drawing planographic printing corresponding to digital data, removing dust on a plate material, and enabling the printing of a large number of printed matter of a sharp image high in image quality by an inexpensive apparatus and a simple method, by reducing the possibility of plate material deformation or occurrence of blister. <P>SOLUTION: In the on-board drawing planographic printing method, when the plate material is mounted on the plate cylinder of a printing press, a tensile force of 0.01 to 100 (kgf/cm<SP>2</SP>, ×0, 98 mPa) is applied to the plate material to mount the plate material, and an image is directly formed on the plate material by an ink jet system for discharging oily ink from a recording head, on the basis of a signal of image data by utilizing an electrostatic field to form a printing plate, and this printing plate is used as it is to continuously perform planographic printing. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-press drawing lithographic printing method and an on-press drawing lithographic printing apparatus for performing digital plate making on a printing press. More specifically, the present invention relates to a plate-making / printing method and a printing apparatus that perform plate-making with an oil-based ink and then perform printing to obtain good plate-making image quality and print image quality.

[0002]

2. Description of the Related Art In planographic printing, ink-receptive and ink-repellent areas are provided on the surface of a printing plate corresponding to an image original, and printing is performed by adhering printing ink to the ink-receptive areas. Usually, hydrophilic and lipophilic (ink receptive) areas are formed in an image-like manner on the surface of a printing plate, and the hydrophilic areas are made to be ink repellent by using dampening water.

Recording of an image on a printing original plate (plate material) (plate making)
First outputs the image original in an analog or digital format to a silver salt photographic film, exposes the diazo resin or photopolymerizable photopolymer photosensitive material through this, and elutes and removes the non-image area mainly using an alkaline solution. It is a common method to do it.

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

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

Further, as a means for increasing the efficiency of the printing process, there is a system for performing image drawing on a printing machine. There is also a method using the above laser, but it is expensive and a large device. Therefore, a system applying the inkjet method, which is an inexpensive and compact drawing device, has been tried.

In Japanese Patent Laid-Open No. 4-97848, a plate drum having a hydrophilic or lipophilic surface is provided in place of a conventional plate cylinder, and a lipophilic or hydrophilic image is formed on the plate drum by an inkjet method. A method of forming, removing the image after completion of printing, and cleaning is disclosed. However, with this method, it is difficult to achieve both removal of the printed image (that is, ease of cleaning) and printing durability. Further, when a print image with high printing durability is to be formed on the plate cylinder, it is necessary to use an ink containing a resin having a relatively high concentration. Therefore, in the inkjet means for forming the print image, solvent evaporation in the nozzle portion is used. As a result, the fixation of the resin is likely to occur and the stability of ink ejection becomes low. As a result, it becomes difficult to obtain a good image.

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

In the ink jet type drawing apparatus, it is usual that ink is ejected from a recording head onto recording paper, and the ink is naturally dried to form an image, and fixing is not performed.
However, with an inkjet using a wax ink, it is difficult for the ink to soak into the recording medium, and therefore heat fixing is performed to ensure image adhesion to the recording medium. Further, in recent years, due to the increase in the printing speed of the inkjet technology, it is necessary to accelerate the drying of ink, and measures are taken such as irradiating UV light after drawing with UV ink or accelerating the drying of the ink solvent by a heating device or the like. It became so. On the other hand, in order to satisfy the requirements of light resistance or hue, it is also possible to coat the colorant fine particles in the ink with a resin or the like,
In that case, image fixing similar to that of an electrophotographic copying machine is required, and heat fixing is preferably used. Further, in a system for making a printing plate used for printing other than the case of directly printing on a recording sheet as a recording medium such as a printer / facsimile as described above, a heat fixing technique is used for the purpose of improving printing durability. Is used.

A heat roller having a heat source is usually used in the heat fixing device, and the heat roller is arranged on the plate cylinder so as to press the plate cylinder. The recording material is passed between the heat roller and the plate cylinder to fix the image on the recording material added from the outside. However, in order to obtain sufficient fixability in a short time when the heat roller pressurizes and heats the recording medium, it is necessary to hold the heat roller at a high temperature and perform fixing. Therefore, plate deformation and blister may occur. One of the causes of plate deformation and blister is described below. At the time of heat fixing at the time of plate making, when pressurizing / heating fixing with a heat roller, the plate material floats up from the cylinder (plate cylinder) when pressed by the heat roller, so that air is trapped under the plate material. There are layers. The air layer serves as a heat insulating layer to suppress the escape of heat to the cylinder, and the temperature locally rises at the portion where the plate material floats. This causes the plate material to deform. Further, when a water-resistant paper plate is used, blister may occur at a high temperature location. Blister is a laminated product such as PE
When it collects between T and T, water from the paper and the image receiving layer may collect between the support and the image receiving layer, and in any case, it becomes an obstacle to high-quality image formation.

On the other hand, in the conventional offset printing machine,
Generally, a clamp accommodating recess extending in the axial direction of the plate cylinder is formed on the outer periphery of the plate cylinder, a pair of clamp devices is provided in the clamp accommodating recess, and each clamp device is wound around the outer periphery of the plate cylinder. There is one in which both ends of the printing plate are clamped to give an appropriate tension to the printing plate. However, if tension is not applied during fixing, plate deformation or blister will occur. Therefore, even if printing is performed by applying tension to the printing plate on which blister has already occurred in the fixing process, high-quality printing is not performed. Further, in the conventionally known on-press drawing lithographic printing, when the printing plate is mounted on the outer periphery of the plate cylinder, there is a device in which both ends of the printing plate are pulled to give tension to the printing plate. However, the tension was such that the plate material did not flutter, and plate deformation and blisters often occurred during fixing. That is, the tension for the purpose of suppressing the plate deformation and the occurrence of the blister was not applied.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and firstly, an object of the invention is to provide a digital corresponding on-press drawing planographic printing method which does not require a developing process, and An object is to provide an on-board drawing lithographic printing apparatus.
Second, on-machine drawing lithographic printing method and on-machine method that makes it possible to print a large number of clear and high-quality printed matter with an inexpensive device and a simple method by making it difficult for plate material deformation and blister to occur. An object is to provide a drawing lithographic printing apparatus.

[0013]

In order to achieve the above object, the on-press drawing lithographic printing method according to claim 1 of the present invention is characterized in that when the plate material is mounted on a plate cylinder of a printing machine, the plate is 0.01 to 100 (kgf / cm ² , × 0,98 mP)
The image is directly formed on the plate material by an inkjet method in which an oil-based ink is ejected from a recording head by using an electrostatic field based on a signal of image data on the plate material, and the image is heated. It is characterized in that a printing plate is prepared by fixing with a roller, and the printing plate is used in that state for subsequent lithographic printing. By such an on-press drawing lithographic printing method, the plate material is applied to the plate cylinder at 0.01 to 10 during plate making.
By applying a tension of 0 (kgf / cm ² ), the plate material is not thermally deformed or blistered at the time of heat fixing, so that a clean plate material can be manufactured.

The on-press drawing lithographic printing apparatus according to claim 2 is
The plate material mounted on the plate cylinder of the printing machine is 0.01 to 100 (k
gf / cm ² , × 0,98 mPa) and an image forming means for directly forming an image on the plate material mounted on the plate cylinder of the printing machine based on a signal of image data. And a fixing means for fixing the image on the plate material formed by the image forming means using a heat roller, and a lithographic printing means for performing lithographic printing on the printing plate having the image fixed by the fixing means. The image forming unit includes a recording head that discharges oil-based ink by using an electrostatic field. When such an on-press drawing lithographic printing apparatus is used, the plate material can be made to have a density of 0.
Since a tension of 01 to 100 (kgf / cm ² ) can be applied to the plate cylinder, the plate can be mounted on the plate cylinder without thermal deformation and blister at the time of heat fixing, so that a clean plate can be manufactured.

Further, in the above-mentioned on-press drawing lithographic printing apparatus, the oil-based ink contains solid and hydrophobic resin particles at least at room temperature in a non-aqueous solvent having a specific electric resistance of 109 Ωcm or more and a dielectric constant of 3.5 or less. It may be characterized by being dispersed. Further, the above-described on-press drawing lithographic printing apparatus may be characterized in that the image forming unit includes the ink fixing device. Further, in the above-described on-press drawing lithographic printing apparatus, the image forming means may perform main scanning by rotating a plate cylinder on which the plate material is mounted when drawing on the plate material. Further, in the above-mentioned on-press drawing lithographic printing apparatus, the recording head comprises a single channel head or a multi-channel head, and the sub-scanning is performed by moving the recording head in the axial direction of the plate cylinder during drawing on the plate material. May be performed. Further, the above-mentioned on-press drawing lithographic printing apparatus may be characterized in that the recording head is a full line head having a length substantially the same as the width of the plate cylinder. Further, the above-mentioned on-press drawing planographic printing apparatus,
The inkjet drawing apparatus may include an ink supply unit that supplies ink to the recording head. Further, the above-described on-press drawing lithographic printing apparatus may be provided with an ink collecting means for collecting ink from the recording head, and the ink may be circulated by the ink supplying means and the ink collecting means. Further, the on-press drawing lithographic printing apparatus may be characterized in that an ink stirring unit is provided in an ink tank that stores the oil-based ink. Further, the above-described on-press drawing lithographic printing apparatus may be characterized in that an ink temperature control means for controlling the temperature of the ink is provided in an ink tank that stores the oil-based ink.
Further, the above-mentioned on-press drawing lithographic printing apparatus may be characterized by including an ink density control means for controlling the ink density of the ink. Further, the above-mentioned on-press drawing planographic printing apparatus,
The inkjet drawing apparatus includes a recording head separating / contacting unit that brings the recording head close to the plate cylinder when drawing on the plate material and separates the recording head from the plate cylinder except when drawing on the plate material. It may be characterized. Further, the above-mentioned on-press drawing lithographic printing apparatus may be characterized in that the image forming means includes a recording head cleaning means for cleaning the recording head at least after completion of plate making. Further, the above-described on-press drawing lithographic printing apparatus may be characterized in that the lithographic printing means includes a paper dust removing means for removing paper dust generated during lithographic printing.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The present invention, on a plate material (printing original plate) provided on a plate cylinder of a printing machine, before forming an image by an inkjet method of ejecting an oil-based ink from a recording head by an electrostatic field and / or during image formation, It is characterized in that the adhesive roller is rolled on the plate material to adsorb and remove dust on the plate material.

The ink jet method according to the present invention is a PC
In the inkjet method, an ink having a high resistance in which solid and hydrophobic resin particles are dispersed at least at room temperature in an insulating solvent is used. By applying a strong electric field at the discharge position, an aggregate of resin particles is formed at the discharge position, and the aggregate is discharged from the discharge position by electrostatic means. In this way, the resin particles are discharged as a high-concentration agglomerate, and the film thickness of the printed dots is sufficiently obtained. As a result, an image of agglomerated resin particles having sufficient printing durability is formed on the plate material that is the recording medium. Further, in the present inkjet method, the size of the ejected ink droplet is determined by the size of the tip of the ejection electrode or the electric field shape condition, and a small ink droplet can be obtained without reducing the ejection nozzle diameter or the slit width. Then, the dot diameter on the plate material can be controlled by controlling the electric field shape condition. Therefore, according to the planographic printing method of the present invention, it is possible to control a minute image having printing durability without the problem of ink clogging of the head, and it is possible to print a large number of clear printed matter.

An example of the construction of an on-press drawing lithographic printing apparatus used for carrying out the lithographic printing method of the present invention is shown below.
FIG. 1 is an overall configuration diagram of an on-press drawing single-color single-sided lithographic printing apparatus. FIG. 2 is a schematic configuration example of a drawing unit including a control unit, an ink supply unit, and a head separation / contact mechanism of the on-machine drawing lithographic printing apparatus. Further, FIGS. 3 to 9 are for explaining an ink jet recording apparatus included in the on-press drawing planographic printing apparatus of FIGS. 1 and 10. Further, FIG. 10 shows an example of the overall configuration of an on-press drawing four-color one-sided lithographic printing apparatus according to the present invention.

First, the printing process according to the present invention will be described with reference to the overall configuration diagram of the on-press drawing single-color one-sided lithographic printing machine shown in FIG. As shown in FIG. 1, the on-press drawing lithographic printing apparatus 1 (hereinafter also simply referred to as “printing apparatus”) includes a plate cylinder 1
1, has one blanket cylinder 17 and one impression cylinder 18,
At least when performing lithographic printing, the transfer blanket cylinder 17 is arranged so as to be in pressure contact with the plate cylinder 11, and the print ink image transferred to the blanket cylinder 17 is transferred to the printing paper P. The impression cylinder 18 is arranged so as to be in pressure contact.

The plate cylinder 11 is usually made of metal, and its surface is plated with, for example, chrome in order to enhance wear resistance, but it may have a heat insulating material on its surface as described later. . On the other hand, it is preferable that the plate cylinder 11 is grounded because it serves as a counter electrode of the ejection head electrode in electrostatic field ejection.
Further, when the substrate of the plate material has a high insulating property, it is preferable to provide a conductive layer on the substrate, and in this case, it is desirable to provide a means for grounding the plate cylinder from the conductive layer. Further, even when the heat insulating material is provided on the plate cylinder as described above, drawing is facilitated by providing a means for grounding the plate material. In this case, known means such as a brush, a leaf spring, and a roller having conductivity can be used. Further, a plate bottom 12 is provided on the plate cylinder 11 to suppress heat escape during fixing.

Further, the printing apparatus 1 has an ink jet recording apparatus (ink jet drawing apparatus) 2, which allows the printing apparatus 1 to be mounted on the plate cylinder 11 corresponding to the image data sent from the image data calculation control unit 21. An oil-based ink is discharged onto the plate material 9 to form an image.

Further, the printing apparatus 1 is provided with a dampening water supply device 3 for supplying dampening water to the hydrophilic portion (non-image portion) on the plate material 9. In FIG. 1, a Molton water supply system is shown as a representative example of the dampening water supply device 3, but as the dampening water supply device 3, other known devices such as a Shinflo water supply system and a continuous water supply system can be used. Further, the printing device 1
It has a printing ink supply device 4 and a fixing device 5 for strengthening the oil-based ink image drawn on the plate material 9. Further, the plate surface desensitizing device 6 may be installed for the purpose of enhancing the hydrophilicity of the surface of the plate material 9.

In the printing apparatus 1, an adhesive roller 10 for adsorbing and removing dust on the plate material is disposed on the upstream side of the ink jet recording apparatus 2 in the plate material moving direction so as to be rollable on the plate material. is doing. The term "rolling" as used herein means that the adhesive roller 10 moves relative to the plate material while being in contact with the plate material and rotating (including driven rotation or rotation).
In the configuration of the present embodiment, the pressure-sensitive adhesive roller 10 rotates at the fixed position with respect to the rotating plate material, so that the pressure-sensitive adhesive roller 10 is rotated.
And the plate material move relative to each other.

The adhesive roller 10 can be contacted with and separated from the plate material by a separation / contact mechanism (not shown).
The adhesive roller 10 removes dust existing on the surface of the plate material before and / or during drawing on the plate material. That is, the dust on the plate material may be removed only before drawing, only during drawing, before drawing, or during drawing. The adhesive roller 10 can be formed, for example, by applying an adhesive layer on the outer periphery of a cylindrical core material made of metal. Examples of the adhesive layer include an adhesive rubber adhesive and an acrylic adhesive.
The pressure-sensitive adhesive roller 10 is determined by a method according to “Sample of two parallel metal plates bonded with rubber” in the “Adhesion test between metal and vulcanized rubber” section of JIS-K6301 vulcanized rubber physical test method. The obtained adhesive force is preferably 4 hPa or more and 250 hPa or less, and more preferably 7 hPa or more and 180 hPa or less.

In the printing apparatus 1, the adhesive roller 10 is rolled on the plate material to adsorb and remove the dust on the plate material, so that the ink is transmitted through the dust entering between the head and the plate material during plate making. Adhesion on the material is effectively prevented, and good plate making is obtained. Further, it is possible to prevent the recording head from being damaged due to the dust on the plate material adhering to the recording head during image formation. The recording head failure includes ink clogging, for example. Further, it is possible to prevent image defects caused by the ink adhering to the dust on the plate material. The image defects include unevenness of the image surface due to the ink adhering to the dust, color loss due to the separation of the dust adhering to the ink, and the like.

Further, an automatic plate supply device 7 for automatically supplying the plate material 9 onto the plate cylinder 11 and an automatic plate discharge device 8 for automatically removing the plate material 9 after printing may be installed. As a printing machine having this device known as an auxiliary device of the printing machine, for example, Hamada VS34A, B452A (Hamada Printing Machinery Co., Ltd.), Toko 8000PFA (Tokyo Aviation Instrument Co., Ltd.), Ryobi 3200ACD, 3200PFA
(Ryobi Imagisque Co., Ltd.), AMSIS Multi
i5150FA (Japan AM Co., Ltd.), Oliver 26
6 EPZ (Sakurai Graphic Systems Co., Ltd.), Shinohara 66 IV / IVP (Shinohara Shoji Co., Ltd.) and others. Further, a blanket cleaning device 14 and an impression cylinder cleaning device 14 'may be installed. By using these devices 7, 8, 14, 14 ', the printing operation becomes simpler and the printing time can be shortened, so that the effect of the present invention can be further enhanced. Further, a paper dust generation preventing device (paper dust removing means) 15 may be installed in the vicinity of the impression cylinder 18, whereby the paper dust can be prevented from adhering to the plate material. As the paper dust generation preventing device 15, methods such as humidity control, suction by air or electrostatic force can be used.

A tension applying means for applying a tension to the plate material 9 is provided according to the present invention. Reference numeral 13 is a tension applying means, which is composed of a plate edge holding device 131 and a plate edge holding device 132, and the plate edge holding device 131 further includes 131a.
The tension adjusting slider, the spring 131b, the clamper 131c, and the base 131d. The plate tails and the plate head clampers themselves have known structures. The base 131d is fixed to the plate cylinder 11, and the clamper 1
31c is the base 131 with the plate head of the plate material 9 held.
It is slidable in the circumferential direction of the plate cylinder 11 along d. One end of a spring 131b is fixed to the back side of the clamper 131c, and the other end is fixed to a tension adjusting slider 131a. The tension adjusting slider 131a is a base 131.
It is adapted to be positioned and fixed manually or automatically at a plurality of positions on the plate cylinder 11 in the circumferential direction of the plate cylinder 11. In the case of manual operation, it can be realized by forming grooves at a plurality of positions on the base 131d and forming a locking portion for locking the grooves on the bottom of the tension adjusting slider 131a. In the case of automatic, it can be realized by an electromagnetic means such as an electromagnetic solenoid. In addition, without using the spring 131b, the clamper 13
1c itself may be replaced by another suction device, such as air means, hydraulic means,
You may attract using an electromagnetic means.

In FIG. 1, the plate edge holding device 131 is slidable in the circumferential direction of the plate cylinder 11, but conversely, even if the plate trailing edge holding device 132 is slidable in the circumferential direction of the plate cylinder 11, both of them are slidable. It may be slidable. Further, in FIG. 1, the tension applying means 13 is projected on the plate cylinder 11, but the plate cylinder 11 is provided with a recess extending in the axial direction and the circumferential direction,
The tension applying means 13 may be embedded in the plate cylinder 11 so as not to project onto the plate cylinder 11.

The plate making process by the plate making apparatus 1 will be described below with reference to FIGS. 1 and 2.

First, the plate material 9 is mounted on the plate cylinder 11 using the automatic plate feeder 7. At this time, the known plate clamper 131
The plate head of the plate material 9 is clamped using c, the plate material 9 is fed out along the plate cylinder 11 while rotating the plate cylinder 11, and the plate butt clamp 132 clamps the plate butt. After that, the tension applying means 13 of the present invention is operated to operate the plate edge holding device 131.
And at least one of the plate edge holding device 132 (in the figure, the plate edge holding device 131) the tension adjusting slider 1
31a is slid in the rotating direction of the plate cylinder 11 to give a greater tension to the plate material 9 than during printing. As a result, plate 9
Is tightly adhered and fixed on the plate cylinder 11 in a tensioned state, whereby the plate bottom can be prevented from flapping and coming into contact with the inkjet drawing device 2 at the time of drawing and being damaged, and the adhesive strength between the metal foil and the base paper and the internal bonding of the base paper. The lack of strength is reinforced, blisters do not occur, and the plate surface temperature does not rise locally due to the plate floating during fixing. Thereby, plate deformation and blister can be suppressed.

The printing apparatus 1 also has a pressing roller 48 on the downstream side of the ink jet recording apparatus 2 in the plate material moving direction. The pressing roller 48 is, for example, a roller whose surface is subjected to Teflon (registered trademark) processing, and is placed in a pressed state or a non-pressed state with respect to the plate cylinder 11 on the downstream side of the inkjet recording apparatus 2. Controllably arranged.
Further, the pressing roller 48 may have an adhesive layer formed on the outer periphery thereof so as to have an adhesive force, like the adhesive roller 10 described above. Therefore, with such a configuration, the dust on the plate material can be adsorbed and removed by causing the adhesive roller 10 and the pressing roller 48 to cooperate with each other before the image formation, and the dust can be added without adding a new adhesive roller 10. The removal capacity can be increased. Further, when a sufficient dust adsorption / removal effect is obtained by making the pressing roller 48 an adhesive roller, only the pressing roller 48 made an adhesive roller may be used instead of the above-mentioned adhesive roller 10. .

The image data arithmetic control unit 21 receives image data from an image scanner, a magnetic disk device, an image data transmission device, etc., performs color separation, and also has an appropriate number of pixels and gradation for the separated data. Divide into numbers. Further, the dot area ratio is also calculated in order to draw the oil-based ink image as a dot using the inkjet ejection head 22 (see FIG. 2 which will be described later in detail) as a recording head of the inkjet recording apparatus 2. .

Further, as will be described later, the image data calculation control unit 21 controls the movement of the ink jet ejection head 22 and the ejection timing of the oil-based ink, and also the plate cylinder 11, the blanket cylinder 17, and the impression cylinder 18 as necessary. It also controls the operation timing of the above.

A printing apparatus 1 with reference to FIG. 1 and partly FIG.
The process of making a printing plate by means of will be described below.

First, the plate material 9 is mounted on the plate cylinder 11 using the automatic plate feeder 7. At this time, the plate material is adhered and fixed on the plate cylinder by a mechanical method such as a known plate edge / edge gripping device, an air suction device, or an electrostatic method, which causes the plate edge to flutter and to be drawn at the time of drawing. Inkjet recording device 2
It is possible to prevent contact with and damage. Further, a means for bringing the plate material into close contact with the plate cylinder only around the drawing position of the ink jet recording apparatus is provided, and at least when drawing is performed, this means is acted to prevent the plate material from contacting the ink jet recording apparatus. You can also Although the pressing roller 48 is arranged on the downstream side of the plate cylinder drawing position in the plate material moving direction as shown in FIG. 1, it may be arranged on the upstream side. Further, by providing means for preventing the plate edge from coming into contact with the ink supply roller in the process of fixing the plate,
It is possible to prevent stains on the printing plate and reduce wasted paper. Specifically, a pressing roller, a guide, electrostatic attraction or the like is effective.

Image data from the magnetic disk device, etc.
The image data calculation control unit 21 is supplied to the image data calculation control unit 21, and calculates the ejection position of the oil-based ink and the halftone dot area ratio at that position according to the input image data. These calculation data are temporarily stored in the buffer. The image data calculation control unit 21 rotates the plate cylinder 11 to bring the ejection head 22 close to a position close to the plate cylinder 11 by the head separating / contacting device (recording head separating / contacting unit) 31. The distance between the ejection head 22 and the surface of the plate material 9 on the plate cylinder 11 is controlled by a mechanical distance control such as an abutting roller or a head separation / contact device controlled by a signal from an optical distance detector during drawing. It is kept at a certain distance. With this distance control, the dot diameter will not be uniform due to floating of the plate material, etc., and the dot diameter will not change especially when vibration is applied to the printing machine,
Good plate making can be obtained.

A single-channel head, a multi-channel head, or a full-line head can be used as the ejection head 22, and main scanning is performed by rotating the plate cylinder 11. In the case of a multi-channel head having a plurality of ejection parts or a full line head, the ejection parts are arranged in the axial direction. Further, in the case of a single-channel head or a multi-channel head, the image data calculation control unit 21 causes the head 22 to rotate once for each revolution of the plate cylinder 11.
Is moved in the axial direction of the plate cylinder, and the oil-based ink is discharged onto the plate material 9 mounted on the plate cylinder 11 at the discharge position and the dot area ratio obtained by the above calculation. As a result, a halftone image corresponding to the shading of the print document is drawn on the plate material 9 with the oil-based ink.
This operation is continued until an oil ink image for one color of the printing original is formed on the plate material 9 and the printing plate is completed. On the other hand, when the ejection head 22 is a full line head having a length substantially the same as the width of the plate cylinder, one rotation of the plate cylinder forms an oil-based ink image for one color of the printing original on the plate material 9. A printing plate is completed. By performing the main scanning by rotating the plate cylinder in this manner, it is possible to improve the position accuracy in the main scanning direction and perform high-speed drawing.

Next, in order to protect the ejection head 22,
The ejection head 22 is retracted away from the position close to the plate cylinder 11. At this time, only the ejection head 22 may be separated and contacted, but the ejection head 22 and the head sub-scanning unit 32 may be separated or contacted together, or the ejection head 22, the ink supply unit 24, and the head sub-scanning unit 32 may be separated together. You can also contact them. In addition to the ejection head 22, the ink supply unit 24, and the head sub-scanning unit 32, the fixing device 5 and the adhesive roller 10 are also provided with contact / separation units so that they can be retracted, so that normal printing can be supported.

The separating / connecting means operates so that the recording head is separated from the plate cylinder by at least 500 μm or more except during drawing. The detaching / attaching operation may be a slide type, or the 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 head during non-drawing in this way, the head can be protected from physical damage or contamination and a longer life can be achieved.

The formed oil-based ink image is reinforced by heating in the fixing device 5. Heat roll fixing is mainly used as the ink fixing means.
Other known heat fixing means can be used in combination. For example, there is infrared lamp, halogen lamp or xenon flash lamp irradiation, or hot air fixing using a heater. Further, in order to improve the fixing property, it is advisable to take measures such as heating the drum, preheating the plate material 9, performing drawing while applying hot air, and coating the drum 11 with a heat insulating material. 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, the dampening water supply device 3, the printing ink supply device 4, and the blanket cylinder 17 are not connected to the plate material 9 on the plate cylinder. It is desirable to keep it out of contact.

The printing process after forming the printing plate is the same as the known lithographic printing method. That is, printing ink and dampening water are applied to the plate material 9 on which the oil-based ink image is drawn to form a printing image, and the printing ink image is transferred onto the blanket cylinder 17 rotating with the plate cylinder 11. Then, by transferring the printing ink image on the blanket cylinder 17 onto the printing paper P passing between the blanket cylinder 17 and the impression cylinder 18, printing for one color is performed. Plate material 9 after printing
Is removed from the plate cylinder 11 by the automatic plate discharging device 8, and the blanket on the blanket cylinder 17 is cleaned by the blanket cleaning device 14 to be ready for the next printing.

Next, the ink jet recording apparatus 2 will be described in detail. As shown in FIG. 2, the drawing unit used in the planographic printing apparatus is an inkjet recording apparatus 2,
The ink supply unit 24. The ink supply unit 24 further includes an ink tank 25, an ink supply device 26, and an ink density control unit 29, and the ink tank 25 includes an ink stirring unit 27 and an ink temperature management unit (ink temperature control unit) 28. . The ink may be circulated in the head, and in this case, the ink supply unit also has a recovery circulation function. The ink stirring means 27 suppresses the precipitation / aggregation of the solid components of the ink, and the need for cleaning the ink tank is reduced. As the ink stirring means, a rotary feather, an ultrasonic transducer,
Circulating pumps can be used and can be used from among or in combination. The ink temperature management unit 28 is arranged so that a high-quality image can be stably formed without changing the physical properties of the ink due to a change in ambient temperature and changing the dot diameter. As the ink temperature control means, a heater, a Peltier element or other heating element or cooling element is arranged in the ink tank together with the stirring means so as to keep the temperature distribution in the tank constant, and is controlled by a temperature sensor such as a thermostat. A publicly known method such as can be used.
The ink temperature in the ink tank is 15 ℃ or more and 60 ℃ or more.
The following is desirable, and more preferably 20 ° C or higher and 50 ° C or lower. Further, the stirring means for keeping the temperature distribution in the tank constant may be shared with the ink stirring means for the purpose of suppressing precipitation / aggregation of the solid components of the ink.

Further, this printing apparatus has an ink density control means 29 for performing high quality drawing. As a result, it is possible to effectively suppress the occurrence of bleeding on the plate due to the decrease in the solid content concentration in the ink, the jumping and blurring of the printed image, and the change in the dot diameter on the plate due to the increase in the solid content concentration. The ink density is measured by optical detection, electrical conductivity measurement, physical property measurement such as clay measurement, or control by the number of drawn images. When performing management by physical property measurement, in the ink tank or in the ink flow path, an optical detector, an electric conductivity measuring instrument, a clay measuring instrument are provided alone or in combination thereof, and according to the output signal thereof, In the case of management by the number of drawn sheets, the liquid supply from the replenishing concentrated ink tank or the diluting ink carrier tank (not shown) to the ink tank is controlled according to the number of plates and the frequency.

As described above, the image data calculation control section 21 calculates the input image data, and the head contact / separation device 3
1 or moving the head by the head sub-scanning means 32, the timing pulse from the encoder 30 installed on the plate cylinder is fetched, and the head is driven according to the timing pulse. As a result, the positional accuracy in the sub-scanning direction can be improved. Further, the driving of the plate cylinder at the time of performing drawing by the inkjet recording apparatus can also improve the positional accuracy in the sub-scanning direction by using a highly accurate driving unit different from the driving unit at the time of printing. In that case, it is desirable to drive only the plate cylinder by mechanically separating it from the blanket cylinder, the impression cylinder and the like. Specifically, for example, there is a method in which the output from a high-precision motor is decelerated by a high-precision gear, a steel belt or the like to drive only the plate cylinder. When performing high-quality drawing, such means alone
Alternatively, they are used in combination.

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

3 and 4 show an example of a head provided in the ink jet recording apparatus. The head 22 includes an upper unit 221 and a lower unit 22 made of an insulating base material.
2 has a slit sandwiched between the discharge electrode 22b and the discharge electrode 22b.
And the ink 23 supplied from the ink supply device.
Is filled in the slit. As the insulating base material, for example, plastic, glass, ceramics or the like can be applied. The ejection electrode 22b is formed by vacuum-depositing, sputtering, or electroless plating a conductive material such as aluminum, nickel, chromium, gold, or platinum on the lower unit 222 made of an insulating base material, and applying a photoresist on this. Is applied, the photoresist is exposed through a mask having a predetermined electrode pattern, and the photoresist is developed to form a photoresist pattern of the ejection electrode 22b. Then, a method of etching this or a method of mechanically removing it, or It is formed by a known method such as a combination method.

In the head 22, a voltage is applied to the ejection electrode 22b according to a digital signal of image pattern information. As shown in FIG. 3, a plate cylinder 11 serving as a counter electrode is provided so as to face the ejection electrode 22b, and a plate material 9 is provided on the plate cylinder 11 serving as a counter electrode. By applying a voltage, a circuit is formed between the ejection electrode 22b and the plate cylinder 11 serving as the counter electrode, and the oil ink 23 is ejected from the ejection slit 22a of the head 22 and provided on the plate cylinder 11 serving as the counter electrode. An image is formed on the printed plate material 9.

The width of the ejection electrode 22b is preferably as thin as possible in order to form a high quality image. The specific numerical value varies depending on the conditions such as the applied voltage and the physical properties of the ink, but is usually used in the range of the tip width of 5 to 100 μm. For example, a discharge electrode 22b having a width of 20 μm at the tip is used, the distance between the discharge electrode 22b and the plate cylinder 11 serving as a counter electrode is 1.0 mm, and a voltage of 3 kV is 0.
By applying for 1 millisecond, 40 μm dots can be formed on the plate material 9.

Further, FIGS. 5 and 6 are a schematic cross-sectional view and a schematic front view of the vicinity of an ink ejection portion of another ejection head example. In the figure, 22 is a discharge head, and this discharge head 22 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 face each other with a space therebetween, and a sloped surface 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. The upper surface portion 36 forming an acute angle with the inclined surface portion 35 of the second insulating base material 34 includes
A plurality of ejection electrodes 22b are provided as electrostatic field forming means for forming an electrostatic field in the ejection portion. The tip of each of the plurality of ejection electrodes 22b extends to the vicinity of the tip of the upper surface portion 36, and the tip is protruded in front of the first insulating base material 33 to form an ejection portion. First above
An ink inflow path 37 is formed between the second insulating base material 33 and 34 as a means for supplying the ink 23 to the ejection portion, and an ink recovery path is provided on the lower side of the second insulating base material 34. 38 is formed. The ejection electrode 22b has a second
A conductive material such as aluminum, nickel, chromium, gold, or platinum is used on the insulating base material 34 and is formed by a known method as described above. The individual electrodes 22b are configured to be electrically insulated from each other.

The amount by which the tip of the ejection electrode 22b projects from the tip of the insulating base material 33 is preferably 2 mm or less. The reason why the amount of protrusion is preferably in the above range is that if the amount of protrusion is too large, the ink meniscus does not reach the tip of the ejection portion,
This is because ejection becomes difficult and the recording frequency decreases. The space between the first and second insulating base materials 33 and 34 is preferably in the range of 0.1 to 3 mm. The reason why this space is preferable in the above range is that if the space is too narrow, it becomes difficult to supply ink and ejection becomes difficult, 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, and when recording is performed, a voltage is applied to the ejection electrode based on image information to eject ink on the ejection electrode. Drawing is performed on a plate material (not shown) that is arranged so as to face each other. The direction opposite to the ink droplet ejection direction of the ink inflow path 37 is connected to an ink feeding means of an ink supply device (not shown). The second insulating base material 3
A backing 39 is provided on the surface opposite to the ejection electrode forming surface of No. 4 so as to face each other with a space therebetween, 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 will be difficult to collect the ink and ink leakage will occur. The ink recovery passage 38 is connected to an ink recovery device (not shown) of an ink supply device.

If a uniform ink flow on the ejection portion is required, a groove 40 may be provided between the ejection portion and the ink recovery passage. FIG. 6 shows a schematic front view of the vicinity of the ink ejection portion of the ejection head. On the slope of the second insulating base material 34, the ink recovery path 3 is formed from the vicinity of the boundary with the ejection electrode 22b.
8 are provided with a plurality of grooves 40. This groove 4
A plurality of 0s 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 diameter of the ejection electrode 22b. Is discharged to the ink collecting path 38. Therefore, it has a function of forming an ink flow having a constant liquid thickness near the tip of the ejection electrode. The shape of the groove 40 may be in a range where a capillary force works, but it is particularly preferable that the width is 10 to 200 μm and the depth is 10 to 300.
It is in the range of μm. Further, the grooves 40 are provided in the required number so that a uniform ink flow can be formed over the entire surface of the head.

The width of the ejection electrode 22b is preferably as thin as possible in order to form a high quality image. The specific numerical value varies depending on the conditions such as the applied voltage and the physical properties of the ink, but it is usually used in the range of the tip width of 5 to 100 μm.

Further, another example of the ejection head used for carrying out the present invention is shown in FIGS. FIG. 7 is a schematic view showing only a part of the head for explanation. The recording head 22 is, as shown in FIG. 7, a head body 4 made of an insulating material such as plastic, ceramic or glass.
1 and meniscus regulating plates 42, 42 '. 2 in the figure
Reference numeral 2b is an ejection electrode for applying a voltage to form an electrostatic field in the ejection portion. Further, from the head to the regulation plates 42, 42 '
The head body will be described in detail with reference to FIG.

The head body 41 is provided with a plurality of ink grooves 43 for circulating ink perpendicularly to the edge of the head body. The shape of the ink groove 43 may be set in a range in which a capillary force works so as to form a uniform ink flow, but a particularly desirable width is 10 to 200 μm,
The depth is 10 to 300 μm. A discharge electrode 22b is provided inside the ink groove 43. This ejection electrode 22
In the ink groove 43b, a conductive material such as aluminum, nickel, chromium, gold, or platinum is used on the head body 40 made of an insulating material by a known method similar to that of the above-described apparatus embodiment. It may be arranged on the entire surface or may be formed on only a part. The ejection electrodes are electrically isolated. Two adjacent ink grooves form one cell, and the ejection portion 4 is provided at the tip of the partition wall 44 at the center thereof.
5, 45 'are provided. In the ejection portions 45 and 45 ', the partition walls are thinner than the other partition wall portions 44 and are sharpened. Such a head body is produced by a known method such as machining of an insulating material block, etching, or molding. The thickness of the partition wall at the ejection portion is preferably 5 to 100 μm, and the radius of curvature of the sharpened tip is preferably in the range of 5 to 50 μm. The discharge portion may have a slightly chamfered end like 45 '. Although only two cells are shown in the figure,
The cells are partitioned by a partition wall 46, and the tip end portion 47 thereof is chamfered so as to be retracted from the discharge portions 45 and 45 '. To this head, ink is supplied from an ink supply device (not shown) through an ink groove from the direction I to supply the ink to the ejection portion. Further, the excess ink is recovered in the O direction by an ink recovery means (not shown), and as a result, fresh ink is constantly supplied to the ejection portion. In this state, ink is ejected from the ejection portion by applying a voltage to the ejection electrode according to the image information to a plate cylinder (not shown) having a plate material held on the surface thereof so as to face the ejection portion. An image is formed on the plate material.

Another embodiment of the ejection head will be described with reference to FIG. As shown in FIG. 9, the ejection head 2
The reference numeral 2 has a pair of support members 50 and 50 'having a substantially rectangular plate shape. These supporting members 50, 50 'are made of an insulating plate-like plastic having a thickness of 1 to 10 mm, glass, ceramics, etc., and one surface of each of them is parallel to each other depending on the recording resolution. A plurality of elongated rectangular grooves 51, 51 'are formed. Each groove 51, 51 '
Is preferably in the range of 10 to 200 μm in width and 10 to 300 μm in depth, and the ejection electrode 22b is formed in the whole or a part of the inside. In this way, by forming the plurality of grooves 51, 51 'on one surface of the support member 50, 50', a plurality of rectangular partition walls 52 are provided between the grooves 51.
Is inevitably provided. Each support member 50, 50 'is assembled such that the surfaces not forming the grooves 51, 51' face each other. That is, the ejection head 22 has a plurality of grooves on the outer peripheral surface for circulating the ink. The grooves 51, 51 'formed in the respective support members 50, 50' are connected in a one-to-one correspondence via the rectangular portions 54 of the ejection head 22, and the rectangular portions 54 in which the respective grooves are connected are ejected. It is retracted from the upper end 53 of the head 22 by a predetermined distance (50 to 500 μm). That is, the upper ends 55 of the partition walls 52 of the support members 50 and 50 ′ are provided on both sides of each rectangular portion 54 so as to project from the rectangular portion 54. Then, the guide projections 56 made of an insulating material as described above are provided so as to project from each rectangular portion 54 to form a discharge portion.

When the ink is circulated through the ejection head 22 having the above-described structure, the ink is supplied to the rectangular portions 54 through the grooves 51 formed on the outer peripheral surface of the one supporting member 50, and the ink is supplied to the opposite side. Each groove 5 formed in the supporting member 50 'of
Discharge via 1 '. In this case, the ejection head 22 is inclined at a predetermined angle in order to enable smooth ink circulation. That is, the ejection head 22 is inclined so that the ink supply side (support member 50) is located above and the ink discharge side (support member 50 ') is located below.
In this way, when 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 in which the ink meniscus is formed independently in each rectangular portion 54,
Ink is ejected from the ejection portion by applying a voltage to the ejection electrode 22b based on image information with respect to a plate cylinder (not shown) which is provided so as to face the ejection portion and holds the plate material on its surface. An image is formed on. 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'. The ink may be forcibly circulated by. In this case, it is not necessary to tilt the ejection head 22.

The head 22 shown in FIGS. 3 to 9 may include a maintenance device such as a recording head cleaning means, if necessary. For example, when the pause state continues, or when a problem occurs in the image quality, wipe the tip of the ejection head with a flexible brush, brush, cloth, etc., circulate only the ink solvent, supply only the ink solvent, Alternatively, a good drawing state can be maintained by performing a single means or a combination of means such as sucking the discharge portion while circulating. In order to prevent the ink from sticking, it is also effective to cool the head part and suppress the evaporation of the ink solvent. If the dirt is severe, ink is forcibly sucked from the discharge part, air, ink, or a jet of ink solvent is forcibly injected from the ink flow path, or the head is soaked in the ink solvent and the ink is Applying a sound wave is also effective, and these methods can be used alone or in combination.

An on-press drawing multicolor single-sided lithographic printing apparatus will be described as a specific example of the present invention. FIG. 10 shows an example of the overall configuration of an on-press drawing four-color single-sided lithographic sheet-fed printing apparatus. Figure 1
As shown in FIG. 0, the 4-color single-sided planographic printing apparatus basically prints the plate cylinder 11, the blanket cylinder 17, and the impression cylinder 18 of the single-color single-sided printing apparatus shown in FIG. 1 on the same side of the printing paper P. Is a structure having four each.
Although not shown, a known transfer cylinder method or the like is used to transfer the printing paper indicated by K in the drawing between the adjacent impression cylinders. Although detailed description is omitted, as can be easily understood from the example of FIG. 10, the other multicolor single-sided printing devices are basically the same as the plate cylinder 11, the blanket cylinder 17, and the impression cylinder 18 of the printing paper P of the single-color single-sided printing device. It has a structure in which a plurality of plates are provided so that printing is performed on the surface. When only one color plate is prepared on the plate cylinder, the plate cylinders and blanket cylinders are provided for the number of colors to be printed. (Such a printing device is referred to as a unit-type printing device.) On the other hand, a common impression cylinder type that shares one impression cylinder having a diameter that is an integral multiple of the impression cylinder diameter with respect to the plate cylinders and blanket cylinders for a plurality of colors. When implementing the present invention on a printing device,
It is possible to have a structure in which one impression cylinder is shared by the plate cylinders and blanket cylinders for the number of colors to be printed, or there are multiple structures in which one impression cylinder is shared by multiple color plate cylinders and blanket cylinders. ,
The structure may be such that the total number of blanket cylinders is equal to the number of colors to be printed. In this case, the known transfer cylinder method or the like can be used to transfer the printing paper between the adjacent common impression cylinders.

On the other hand, in the case of producing a plurality of color plates on the plate cylinder, the plate cylinder and the blanket cylinder are required by the value obtained by dividing the number of colors to be printed by the plate number on one plate cylinder. For example, when two color plates are formed on the plate cylinder, four-sided printing on one side can be performed by a printing device having two plate cylinders and two blanket cylinders. In this case, the impression cylinder diameter is the same as the plate cylinder diameter for one color,
If necessary, a means for holding the printing paper until the printing of the required color is completed is installed in the impression cylinder, and a known transfer cylinder method or the like is used to transfer the printing paper between the impression cylinders. In the case of a printing machine having two plate cylinders and two blanket cylinders for which the above-described plate materials for two colors are created, one of the impression cylinders holds the printing paper and rotates two times to perform two-color printing. When the printing paper is transferred between the cylinders, and then the other impression cylinder holds the printing paper and rotates twice, two-color printing is further performed and four-color printing is completed. The number of impression cylinders may be the same as the number of impression cylinders, but one impression cylinder may be shared by several impression cylinders and blanket cylinders.

On the other hand, when the present invention is embodied as an on-press drawing multicolor double-sided lithographic sheet-fed printing apparatus, a known printing paper reversing means is provided between at least one adjacent impression cylinder of the unit type printing apparatus described above. Or, a structure in which a plurality of the above-mentioned common impression cylinder type printing devices are arranged and a known printing paper reversing means is provided between at least one adjacent impression cylinders, or the plate cylinder 11 and the blanket of the single-color single-sided printing device shown in FIG. The structure has a plurality of cylinders 17 so that printing is performed on both sides of the printing paper P. In the structure shown in FIG. 1, when only one color plate is prepared on the plate cylinder, the plate cylinder and the blanket cylinder are provided by the number of colors necessary for printing on both sides of the printing paper. On the other hand, when a plurality of color plates are formed on the plate cylinder as described above, the number of plate cylinders, blanket cylinders, and impression cylinders can be reduced. Moreover, when one impression cylinder is shared by several plate cylinders and blanket cylinders, the number of impression cylinders can be further reduced. If necessary, the plate cylinder is provided with a means for holding the printing paper until printing of the required colors is completed. The details are omitted because they can be easily understood from the example of the above-described on-press drawing multicolor single-sided lithographic printing machine.

An example of a sheet-fed printing apparatus has been described above as an embodiment of the on-press drawing multicolor lithographic printing apparatus of the present invention. On the other hand, when the present invention is carried out as an on-press drawing multicolor WEB (rolling paper) lithographic printing apparatus, the unit type and the common impression cylinder type described above can be preferably used. When the present invention is embodied as an on-machine drawing multicolor WEB double-sided printing device, both the unit type and the common impression cylinder type are provided with a known WEB reversing means between at least one adjacent impression cylinder, and printing paper. This can be achieved by a structure having a plurality of sheets so that printing is performed on both sides of P. Further, a BB (blanket-to-blanket) type is most suitable as the on-machine drawing multicolor WEB double-sided printing device. This is a one-color plate cylinder for printing one side of the WEB, a blanket cylinder (no impression cylinder) and a one-color plate cylinder for printing the other side, and a blanket cylinder (blanket cylinder) Multi-color double-sided printing is achieved by having a structure in which the two are pressed against each other at the time of printing for the number of colors and the WEB passes between the blankets pressed at the time of printing.

As another example of the on-press drawing lithographic printing apparatus, one blanket cylinder has two plate cylinders, and when printing is performed on one side, drawing is performed on the other plate cylinder. You can also In this case, it is desirable that the driving of the plate cylinder performing drawing is mechanically independent of the blanket. This makes it possible to draw without stopping the printing press. As you can easily understand,
This on-board drawing lithographic printing apparatus can be applied to an on-board drawing multicolor single-sided lithographic printing apparatus and an on-board drawing multicolor double-sided lithographic printing apparatus.

Next, the plate material (printing original plate) used in the present invention will be described. As the printing original plate, as a cheap plate material, water-resistant paper, plastic film,
A plate material having an image receiving layer on a water resistant support such as paper laminated with plastic can be used. The thickness of the image receiving layer provided is appropriately in the range of 5 to 30 μm. When the present invention is applied, it is effective in suppressing plate deformation and blister of these plate materials. In addition, aluminum,
A metal plate such as a steel plate plated with chrome may be used.
In particular, an aluminum plate having excellent surface water retention and abrasion resistance by graining or anodizing treatment is preferable, but these are also effective according to the present invention because plate deformation is suppressed.

As the image receiving layer, a hydrophilic layer composed of an inorganic pigment and a binder, or a layer which can be rendered 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 or the like can be used.
Further, as the binder, a hydrophilic binder such as polyvinyl alcohol, starch, carboxymethyl cellulose, hydroxyethyl cellulose, casein, gelatin, polyacrylate, polyvinyl pyrrolidone, polymethyl ether-maleic anhydride copolymer can be used. .. Further, if necessary, a melamine formalin resin, a urea formalin resin, or other cross-linking agent that imparts water resistance may be added.

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

Zinc oxide used in the present invention is, for example, zinc oxide, zinc oxide, as described in “New Edition Pigment Handbook” edited by Japan Pigment Technology Association, page 319, Seibundou Co., Ltd. (published in 1968). Any of those commercially available as wet zinc white or activated zinc white may be used. That is, zinc oxide is classified into a dry method such as a French method (indirect method), an American method (direct method), and a wet method depending on the starting material and the manufacturing method. For example, Shodo Kagaku Co., Ltd. ), Hakusui Chemical Co., Ltd., Honjo Chemical Co., Ltd., Toho Zinc Co., Ltd., Mitsui Metal Industry Co., Ltd. and the like.

Specific examples of the resin used as the binder include styrene copolymer, methacrylate copolymer, acrylate copolymer, vinyl acetate copolymer, polyvinyl butyral, alkyd resin, epoxy resin and epoxy ester. Resin, polyester resin, polyurethane resin and the like can be mentioned. These resins may be used alone or in combination of two or more. The resin content in the image receiving layer is 9/91 in terms of the resin / zinc oxide weight ratio.
It is preferable to be set to 20/80.

Desensitization of zinc oxide is carried out by a conventional method using a desensitizing treatment liquid, and conventionally, as a desensitizing treatment liquid of this kind, a cyanide compound containing ferrocyan salt or ferricyan salt as a main component is used. Containing treatment liquid, amminecobalt complex,
Known are phytic acid and its derivatives, cyanide-free treatment liquids containing guanidine derivatives as main components, treatment liquids containing inorganic or organic acids that form chelates with zinc ions as main components, or treatment liquids containing water-soluble polymers. Has been.
For example, as a cyanide-containing treatment liquid, Japanese Patent Publication No.
9045, 46-39403, JP-A-52-76.
101, 57-107889, 54-1172.
No. 01 etc. are mentioned. The surface of the plate opposite to the image processing layer has a Bekk smoothness of 150 to 7
It is preferably in the range of 00 (second / 10 cc). As a result, the formed printing plate can be printed satisfactorily without causing misalignment or slippage on the plate cylinder even during printing. Here, the Beck's smoothness can be measured by a Beck's smoothness tester. Beck's smoothness tester presses a test piece at a constant pressure (1 kgf / cm ² (9.8 N / cm ² )) on a circular glass plate with a hole in the center that is highly smooth finished.
The time required for a given amount (10 cc) of air to pass between the glass surface and the test piece under reduced pressure is measured.

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.

Specific electric resistance used in the present invention 10 ⁹ Ωcm
As the non-aqueous solvent having a dielectric constant of 3.5 or less, a linear or branched aliphatic hydrocarbon, alicyclic hydrocarbon, or aromatic hydrocarbon, and halogen-substituted products of these hydrocarbons are preferable. is there. For example, hexane, heptane, octane, isooctane, decane, isodecane, decalin, nonane, dodecane, isododecane, cyclohexane, cyclooctane, cyclodecane, benzene, toluene, xylene, mesitylene, isoper C, isoper E, isoper G, isoper H, isoper L. (Isopar; trade name of Exxon), Shelsol 70, Shelsol 71 (Shellsol; trade name of Shell Oil), Amsco OMS, Amsco 460 solvent (trade name of Amsco; Spirits), silicone oil, etc. Alternatively, they are mixed and 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 becomes low, concentration of resin particles and the like is less likely to occur and sufficient printing durability cannot be obtained, and the dielectric constant is reduced. The reason for setting the above range is that when the dielectric constant is high, the electric field is relaxed due to the polarization of the solvent, and the ejection of the ink is likely to be deteriorated.

The resin particles dispersed in the above non-aqueous solvent may be particles of a hydrophobic resin which are solid at a temperature of 35 ° C. or lower and have good affinity with the non-aqueous solvent. Glass transition point is -5 ° C to 110 ° C or softening point is 33 ° C
The resin (P) having a temperature of ˜140 ° C. is preferable, and more preferably, the glass transition point is 10 ° C. to 100 ° C. or the softening point is 38 ° C. to 1.
20 ° C., more preferably glass transition point 15 ° C.
The softening point is 80 ° C or 38 ° C to 100 ° C.

By using such a resin having a glass transition point or a softening point, the affinity between the image receiving surface of the printing original plate and the resin particles is increased, and the resin particles are strongly bonded to each other on the printing original plate. Therefore, the adhesion between the image area and the image receiving surface is improved, and the printing durability is improved. In contrast,
Whether the glass transition point or the softening point is low or high, the affinity between the image receiving surface and the resin particles is lowered, or the bond 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 and more preferably 1 × 10 ^{4 to} 5 × 10 ⁵ .

Specifically as such a resin (P),
Olefin polymers and copolymers (eg polyethylene,
Polypropylene, polyisobutylene, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, ethylene-methacrylate copolymer, ethylene-methacrylic acid copolymer, etc.), vinyl chloride polymer and copolymer (for example, polychlorinated Vinyl, vinyl chloride-vinyl acetate copolymer, etc.), vinylidene chloride copolymer, vinyl alkanoate polymer and copolymer, allyl alkanoate polymer and copolymer, polymer and copolymer of styrene and its derivatives (For example, butadiene-styrene copolymer, isoprene-
Styrene copolymer, styrene-methacrylate copolymer, styrene-acrylate copolymer, etc.), acrylonitrile copolymer, methacrylonitrile copolymer, alkyl vinyl ether copolymer, acrylic acid ester polymer and copolymer, methacryl Acid ester polymer and copolymer, itaconic acid diester polymer and copolymer, maleic anhydride copolymer, acrylamide copolymer, methacrylamide copolymer, phenol resin, alkyd resin, polycarbonate resin, ketone resin, polyester resin,
Silicone resin, amide resin, hydroxyl group 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 resin Terpene resin, coumarone-indene resin, cyclized rubber-methacrylic acid ester copolymer, cyclized rubber-acrylic acid ester copolymer, copolymer containing a nitrogen atom-free heterocycle (for example, as a heterocycle, furan Ring, tetrahydrofuran ring, thiophene ring, dioxane ring, dioxofuran ring, lactone ring,
Benzofuran ring, benzothiophene ring, 1,3-dioxetane ring and the like), epoxy resin and the like.

The content of the dispersed resin particles in the oil-based ink of the present invention is preferably 0.5 to 20 wt% of the whole ink. When the content is low, the affinity between the ink and the surface of the printing original plate is difficult to obtain, and a good image cannot be obtained, or the printing durability is likely to deteriorate. When the amount is large, it is difficult to obtain a uniform dispersion liquid, and the ink flow in the ejection head is likely to be non-uniform, which makes it difficult to obtain stable ink ejection.

In the oil-based ink used in the present invention, it is preferable to include a coloring material as a coloring component together with the above-mentioned dispersed resin particles in order to inspect the plate after plate making.
As the color material, any pigment and dye conventionally used in oil-based ink compositions or liquid developers for electrostatic photography can be used.

As the pigment, regardless of whether it is an inorganic pigment or an organic pigment, those generally used in the technical field of printing can be used. 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, slene pigments, perylene pigments, perinone pigments, thioindigo pigments, quinophthalone pigments, metal complex pigments, etc. Can be used without.

As the dyes, azo dyes, metal complex salt 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 preferable. These pigments and dyes may be used alone or may be used in combination as appropriate, 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 the coloring materials themselves as dispersed particles in addition to the dispersed resin particles, or may be contained in the dispersed resin particles. When contained, the pigment or the like is generally coated with the resin material of the dispersed resin particles to form resin-coated particles, and the dye or the like is colored the surface portion of the dispersed resin particles to form colored particles. It is common.

The average particle size of these particles including resin particles dispersed in the non-aqueous solvent of the present invention and further colored particles is preferably 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 dispersed resin particles used in the present invention can be produced by a conventionally known mechanical pulverization method or polymerization granulation method. As a mechanical grinding method,
If necessary, materials to be resin particles are mixed, melted and kneaded, and directly pulverized by a conventionally known pulverizer to obtain fine particles. , Eddy mill, dyno mill, etc.), and the resin particle component material,
Examples thereof include a method of previously kneading a dispersion-aiding polymer (or a coating polymer) to form a kneaded product, pulverizing, and then allowing a dispersion polymer to coexist and disperse. Specifically, a method for producing a paint or a liquid developer for electrostatic photography can be used, and for example, for these, for example, Kenji Ueki, "Paint Flow and Pigment Dispersion," Kyoritsu Shuppan (1971), Solomon ". Science of paints "Hirokawa Shoten (1969), Yuji Harazaki" Coating Engineering "Asakura Shoten (1971), Yuji Harazaki" Basic Science of Coatings "Maki Shoten (1977) and others.

Further, as the polymerization granulation method, a conventionally known non-aqueous dispersion polymerization method can be mentioned. Specifically, the latest technology of ultrafine particles supervised by Soichi Muroi, Chapter 2, CMC Publishing (1991). ), Koichi Nakamura, "Recent Development and Practical Use of Electrophotographic Development Systems and Toner Materials," Chapter 3, (Japan Science Information Co., Ltd., 1985), KEJ Barrett "Disper
sion Polymerization in Organic Media '' John Wiley
(1975) and the like.

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

As a preferable soluble repeating unit of the dispersion polymer used in the present invention, a polymerization component represented by the following general formula (1) can be mentioned.

[0088]

[Chemical 1]

In the general formula (I), X1 is --COO.
Represents-, -OCO- or -O-. R has 10 carbon atoms
To 32 alkyl groups or alkenyl groups, preferably C10 to C22 alkyl groups or alkenyl groups, which may be linear or branched and are preferably unsubstituted, but have a substituent. You may have. Specific examples thereof include a decyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, an eicosanyl group, a docosanyl group, a decenyl group, a dodecenyl group, a tridecenyl group, a hexadecenyl group, an octadecenyl group, and a linolenyl group. .

A1 and a2, which may be the same or different from each other, are a hydrogen atom, a halogen atom (eg, chlorine atom, bromine atom, etc.), a cyano group, an alkyl group having 1 to 3 carbon atoms (eg, methyl group, Ethyl group, propyl group, etc.),
-COO-Z1 or -CH2 COO-Z1 [Z1
Is an optionally substituted hydrocarbon group having 22 or less carbon atoms (for example, an alkyl group, an alkenyl group, an aralkyl group,
Represents an alicyclic group, an aryl group, etc.)].

Among the hydrocarbon groups represented by Z1, a preferable hydrocarbon group is an optionally substituted alkyl group having 1 to 22 carbon atoms (eg, methyl group, ethyl group, propyl group, butyl group, hexyl group). 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, etc.), an alkenyl group having 4 to 18 carbon atoms which may be substituted (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.),
Aralkyl groups which may be substituted and have 7 to 12 carbon atoms (for example, benzyl group, phenethyl group, 3-phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group, chlorobenzyl group, bromobenzyl group, methylbenzyl group, Ethylbenzyl group, methoxybenzyl group, dimethylbenzyl group, dimethoxybenzyl group, etc.), alicyclic group having 5 to 8 carbon atoms which may be substituted (eg, cyclohexyl group, 2
-Cyclohexylethyl group, 2-cyclopentylethyl group, etc.) and optionally substituted aromatic group having 6 to 12 carbon atoms (eg, phenyl group, naphthyl group, tolyl group, xylyl group, propylphenyl group, butylphenyl group) , Octylphenyl group, dodecylphenyl group, methoxyphenyl group, ethoxyphenyl group, butoxyphenyl group, decyloxyphenyl group, chlorophenyl group, dichlorophenyl group, bromophenyl group, cyanophenyl group, acetylphenyl group, methoxycarbonylphenyl group, ethoxy Carbonylphenyl group, butoxycarbonylphenyl group, acetamidophenyl group, propionamidophenyl group, dodecyloylamidophenyl group, etc.).

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

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

The dispersion polymer is preferably added in advance during polymerization when the resin (P) particles are produced as a dispersion (latex) or the like. The amount of addition when the dispersion polymer is used is 1 to 50 with respect to the resin (P) for particles.
Set to about wt%.

The dispersed resin particles and colored particles (or coloring material particles) in the oil-based ink of the present invention are preferably positively or negatively charged electroscopic particles. It is possible to impart an electroscopic property to these particles by appropriately utilizing the technique of a developer for wet electrostatic photography. Specifically, the above-mentioned "Development and practical application of recent electrophotographic development systems and toner materials"
Pp. 139-148, edited by The Institute of Electrophotography, "Basics and Applications of Electrophotographic Technology," pages 497-505 (Corona Publishing Co., Ltd., 1988), Yuji Harasaki, "Electrophotography" 16 (No. 2), page 44 (1977), etc. It is carried out by using a charge detecting material such as the charge control agent described in 1. and other additives.

Specifically, for example, British Patent No. 8934.
No. 29, No. 934038, No. 1122397,
U.S. Pat. Nos. 3,900,412 and 4,606,989,
JP-A-60-179751, JP-A-60-185963
And Japanese Patent Laid-Open No. 13965/1990. The charge control agent as described above is used as a dispersion medium 1000 that is a carrier liquid.
0.001 to 1.0 part by weight is preferable with respect to parts by weight.
If desired, various additives may be added, and the upper limit of the total amount of these additives is restricted by the electric resistance of the oil-based ink. That is, if the specific electric resistance of the ink with the dispersed particles removed is lower than 10 ⁹ Ωcm, it becomes difficult to obtain a good quality continuous tone image. Therefore, it is possible to control the addition amount of each additive within this range. desirable.

[0097]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. First, a production example of resin particles (PL) for ink 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 70 ° C. with stirring under a nitrogen stream. did. 0.8 g of 2,2'-azobis (isovaleronitrile) (abbreviation AIVN) was added as a polymerization initiator, and the reaction was carried out for 3 hours. Twenty minutes after the addition of the initiator, white turbidity occurred and the reaction temperature rose to 88 ° C. Further, 0.5 g of this initiator was added and after reacting for 2 hours, the temperature was raised to 100 ° C. and stirred for 2 hours to distill off unreacted vinyl acetate. After cooling, it was passed through a nylon cloth of 200 mesh, and the obtained white dispersion was a latex having a polymerization rate of 90% and an average particle size of 0.23 μm and good monodispersity. The particle size was measured by CAPA-500 (manufactured by Horiba, Ltd.).

[0099]

[Chemical 2]

A part of the white dispersion was subjected to a centrifugal separator (rotation speed 1 × 10 ⁴ rpm, rotation time 60 minutes) to collect and dry the precipitated resin particle component. The weight average molecular weight of the resin particles (Mw: polystyrene-converted GPC value) is 2
× 10 ⁵ , glass transition point (Tg) was 38 ℃.

Examples 1 to 3 First, oil-based inks were prepared. 10 g of a dodecyl methacrylate / acrylic acid copolymer (copolymerization ratio; 95/5 weight ratio) of the oil-based ink (IK-1), 10 g of nigrosine, and 30 g of Shelsol 71 were used together with glass beads in a paint shaker (Toyo Seiki ( Co., Ltd.) and dispersed for 4 hours to obtain a fine dispersion of nigrosine.

Production of Resin Particles for Ink 60 g of resin particles (PL-1) produced in Example 1 (as solid content), 2.5 g of the above nigrosine dispersion, FOC-1400 (manufactured by Nissan Kagaku KK, tetradecyl) Alcohol) 15 g, and octene-half-maleic acid hexadecylamide copolymer 0.
A black oil-based ink was prepared by diluting 08 g with 1 liter of Isopar G.

Next, the on-board drawing lithographic printing apparatus (see FIGS.
2 liters of the oil-based ink (IK-1) prepared as described above was filled in the ink tank of the ink jet recording apparatus (see the reference). Here, a discharge head 900 shown in FIG.
A 64-channel, 64-channel multi-channel head was used. A throw-in heater and a stirring blade were provided in the ink tank as an ink temperature control means, the ink temperature was set to 30 ° C., and the temperature was controlled by a thermostat while rotating the stirring blade at 30 rpm. Here, the stirring blade was also used as a stirring means for preventing precipitation and aggregation. In addition, a part of the ink flow path is made transparent, an LED light emitting element and a light detecting element are arranged with the ink flow path sandwiched therebetween, and an output signal from the LED diluting solution (isopar G) or concentrated ink (solid content of the above IK-1 ink). The concentration was controlled by adding the one whose concentration was adjusted to double.

As the plate material, a paper plate material having a hydrophilic image receiving layer on the surface shown below was used. Basic weight of 10
Using high quality paper of 0 g / m ² , kaolin on the surface of the substrate,
Dispersion A prepared as described below is applied onto a paper support provided with a water resistant layer containing polyvinyl alcohol, SBR latex and a resin component of melamine resin as main components to give a coating amount of 6 g / m ² after drying. Thus, an image receiving layer was provided to prepare a paper plate material.

Dispersion A Gelatin (Wako Pure Chemicals first-class product) 3 g Colloidal silica (manufactured by Nissan Kagaku; Snowtex C, 20% water dispersion) 20 g Silica gel (manufactured by Fuji Silysia Chemical; Sylysia # 310) 7 g Hardener 0. 100 g of 4 g distilled water was dispersed with glass beads for 10 minutes on a paint shaker.

The plate material was set in an automatic plate feeder, and the plate material was mechanically attached to the plate cylinder. Separate the dampening water supply device, the printing ink supply device, and the blanket cylinder so that they do not contact the plate material, remove the dust on the surface of the plate material with the adhesive roller, and bring the discharge head close to the drawing material to the plate material for printing. The image data was transmitted to the image data calculation control unit, and the 64-channel ejection head was moved while rotating the plate cylinder, whereby the oil-based ink was ejected onto the plate to form an image. At this time, the tip width of the ejection electrode of the inkjet head is 10 μm, and if the distance between the plate material and the plate cylinder, that is, the float is 0.1 mm or more, the plate is drawn before drawing according to the output from the optical gap detection device. The material pressing roller (made of Teflon) was operated. Further, during drawing, the distance between the head and the plate material was controlled to always be 1 mm ± 0.03 mm. A voltage of 2.5 kV is always applied as a bias voltage, and a pulse voltage of 500 V is further superimposed when performing ejection, and the pulse voltage is 0.2 ms to 0.05
Drawing was performed while changing the dot area by changing in 256 steps in the range of milliseconds.

(First Example and Comparative Example) As a plate material, 2
A coated paper plate having a thickness of 20 μm was used. A mechanical device provided on the plate cylinder grips and mounts the plate head and plate butt of the coated paper plate, and the tension applying means of the present invention is operated to move the tension adjusting slider of the plate head gripping device in the rotational direction of the plate cylinder. Slide and coat each of the coated paper plates with (1) 0.00
5 (kgf / cm ² , × 0,98 mPa. The following unit is omitted.), (2) 0.01, (3) 0.1, (4) 1,
Tensions of (5) 10, (6) 100, and (7) 120 were applied. Then, after removing dust on the surface of the plate material by suction with an air pump, bring the discharge head close to the plate material to the drawing position,
The image data to be plate-made was transmitted to the image data calculation control section, and the 64-channel discharge head was moved while rotating the drum to discharge the oil-based ink onto the aluminum plate to form an image. At this time, the tip width of the ejection electrode of the inkjet head was 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 detection device. A voltage of 2.5 kV is always applied as a bias voltage, a pulse voltage of 500 V is further superimposed when performing ejection, and the pulse voltage is 256 steps in the range of 0.2 ms to 0.05 ms. Drawing was performed while changing the area of the dots by changing with.
Then, when the plate deformation, the occurrence of blisters, and the elongation due to pulling were examined, the results shown in Table 1 were obtained.

[0108]

[Table 1]

According to Table 1, the tension applied to the plate material is 0.0
When it is as small as 05 (kgf / cm ² ), the elongation of the plate due to pulling is at an allowable level, but the plate is deformed and blisters occur. In addition, the tension applied to the plate material is 0.01 (kgf
/ Cm ² ), the plate was slightly deformed but was acceptable. Blister did not occur. The plate elongation due to pulling was at an acceptable level. Furthermore, the tension applied to the plate material increases to 0.1 to 100 (kgf / c
Within the range of m ² ), the plate did not deform and blisters did not occur. Further, the elongation of the plate due to pulling was at an allowable level. However, when the tension applied to the plate material was further increased to 120 (kgf / cm ² ), the plate did not deform and blisters did not occur, but on the contrary, the plate elongation due to pulling exceeded the allowable level. It was Also,
Dust removal operation on the surface of the plate material showed no drawing defects due to dust, and no image deterioration due to changes in dot diameter due to changes in the outside temperature or an increase in the number of plate making. there were.

(Second Example and Comparative Example) As a plate material, 1
PET (polyethylene terephthalate) with a thickness of 50 μm
The plate was mounted by holding a plate head and a plate bottom by a mechanical device provided on the plate cylinder. After that, the tension applying means according to the present invention is operated to slide the tension adjusting slider of the plate edge holding device in the rotating direction of the plate cylinder, and (1) is applied to the plate material.
0.005, (2) 0.01, (3) 0.1, (4)
Tensions of 1, (5) 10, (6) 100, and (7) 120 were applied. The other conditions were the same as in the first embodiment. That is, after removing dust on the surface of the plate material by suction with an air pump, the ejection head is brought close to the plate material to the drawing position, the image data to be plate-made is transmitted to the image data calculation control unit, and the drum is rotated. By moving the 64-channel discharge head, the oil-based ink was discharged onto the aluminum plate to form an image. At this time, the tip width of the ejection electrode of the inkjet head was 10 μm, and the distance between the head and the plate material was 1 mm due to the output from the optical gap detection device.
It was controlled so that 2.5 kV as bias voltage
Voltage is always applied and 500 V is applied when discharging.
Pulse voltage is further superimposed, and the pulse voltage is 0.2
Drawing was performed while changing the area of dots by changing in 256 steps in the range of millisecond to 0.05 millisecond. Then, when the occurrence of plate deformation and the elongation due to tension were examined, the results shown in Table 2 were obtained.

[0111]

[Table 2]

According to Table 2, the tension applied to the plate material is 0.0
When it is as small as 05 (kgf / cm ² ), the plate elongation due to the pulling is at an allowable level, but the plate is deformed. Further, when the tension applied to the plate material was 0.01 (kgf / cm ² ), the plate was slightly deformed, but it was acceptable. The plate elongation due to pulling was at an acceptable level. Furthermore, the tension applied to the plate material increases to 0.1-100 (k
In the range of gf / cm ² ), the plate does not deform,
Further, the elongation of the plate due to pulling was at an allowable level.
However, the tension applied to the plate material was further increased to 120 (k
gf / cm ² ), the plate did not deform, but
On the contrary, the elongation of the plate due to pulling exceeded the allowable level. Further, no drawing defects due to dust due to the dust removal operation on the plate material surface were observed at all, and no image deterioration due to a change in dot diameter due to a change in the outside temperature or an increase in the number of plate production was observed. It was possible.

What has been found from the above first and second examples and the comparative example is that when the plate material is mounted on the plate cylinder, the tension of 0.01 to 100 (kgf / cm ² ) is applied to the plate material. Is given, deformation of the plate does not occur, blisters do not occur, and elongation of the plate due to pulling is at an allowable level. In order to obtain such tension, it is necessary to equip the plate making apparatus with a tension applying means for obtaining such a tension range on the plate cylinder during plate making.

Further, the image was solidified by heating with a xenon flash fixing device (manufactured by Ushio Inc., emission intensity 200 J / pulse) to prepare a printing plate. In order to protect the inkjet head, the inkjet drawing device together with the sub-scanning means is retracted by 50 mm from the position close to the drum, then the printing plate is taken out from the plate making device, and the oliver 2
Printing was carried out by mounting on a plate cylinder of a 66EPZ printing machine.

The obtained printed matter was an extremely clear image with no jumps or scratches on the printed image even after passing 10,000 sheets. Also, after plate making, the tip of the discharge head is
And a positive DC voltage of 1 kV was applied for 30 seconds to produce a printing plate that gives good printed matter for 6 months without requiring maintenance work.

[0116]

According to the present invention, the plate material is mounted on the plate cylinder of the printing machine, and the electrostatic ink is used to discharge the oil-based ink from the recording head based on the signal of the image data on the plate material. In the on-press drawing lithographic printing method, in which a printing plate is created by directly forming an image by an inkjet method, and the printing plate is continuously used in that state, when the plate material is mounted on the plate cylinder. In addition, 0.01 to 100 (k
Since a tension of gf / cm ² , × 0,98 mPa) was applied, deformation of the plate did not occur, blisters did not occur, and elongation of the plate by pulling was at an allowable level. As a result, it is possible to create a printing plate capable of printing a large number of clear printed matter. Further, a printing plate that directly corresponds to digital image data can be stably created with high image quality, and inexpensive and high-speed lithographic printing can be performed.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram schematically showing an example of an on-press drawing lithographic printing apparatus used in the present invention.

FIG. 2 is a configuration diagram schematically showing an example of a drawing unit of the on-machine drawing lithographic printing apparatus used in the present invention.

FIG. 3 is a schematic configuration diagram showing an example of a head provided in the inkjet recording apparatus used in the present invention.

FIG. 4 is a schematic cross-sectional view of the vicinity of the ink ejection portion of FIG.

FIG. 5 is a schematic cross-sectional view of the vicinity of an ink ejection portion in an example of another head included in the inkjet recording apparatus used in the present invention.

FIG. 6 is a schematic front view of the vicinity of the ink ejection portion of FIG.

FIG. 7 is a schematic configuration diagram showing a main part of an example of another head provided in the inkjet recording apparatus used in the present invention.

8 is a schematic configuration diagram of a head obtained by removing a regulation plate from the head of FIG. 7.

FIG. 9 is a schematic configuration diagram showing a main part of an example of another head provided in the inkjet recording apparatus used in the present invention.

FIG. 10 is an overall configuration diagram schematically showing an on-press drawing four-color one-sided lithographic printing machine as an example of a multicolor machine used in the present invention.

[Explanation of symbols]

1 On-board drawing planographic printing device 2 Inkjet recording device 3 Dampening water supply device 4 Printing ink supply device 5 Fixing device 6 Plate desensitizing device 7 Plate material automatic plate feeder 8 Automatic plate discharge device 9 Plate material (printing original plate) 10 Adhesive roller 11 plate cylinder 12 copy 13 Tension applying means 131 Edition 131a Tension adjustment slider 131b spring 131c clamper 131d base 132 Edition Buttocks 17 blanket body 18 impression cylinder 14 Blanket cleaning device 14 'impression cylinder cleaning device 15 Paper dust generation prevention device 21 Image data calculation controller 22 Discharge head 221 Upper unit 222 Lower unit 22a discharge slit 22b Discharge electrode 23 Oil-based ink 24 Ink supply section 25 ink tanks 26 Ink supply device 27 stirring means 28 Ink temperature control means 29 Ink density control means 30 encoder 31 Head contact / separation device 32 head sub-scanning means 33 First Insulating Base Material 34 Second insulating base material 35 Slope of second insulating base material 36 Upper surface of second insulating base material 37 Ink flow path 38 Ink collection path 39 backing 40 grooves 41 head body 42, 42 'meniscus regulated version 43 ink groove 44 partition 45, 45 'discharge part 46 partitions 47 Partition tip 48 pressure roller 50, 50 'support member 51, 51 'groove 52 partition 53 Upper end 54 rectangle 55 Top of partition 56 Guide protrusion P printing paper

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C020 DA02                 2C056 EA30 FB01 FC02 FC06 FD10                       FD20 HA45                 2C057 AG22 AH05 AH20 BD06 BD07                 2H084 AA25 AA36 AE05 CC05                 2H086 BA05 BA54

Claims (2)

[Claims] 1. When the plate material is mounted on a plate cylinder of a printing machine, the plate material is 0.01 to 100 (kgf / cm ² , × 0.9).
(8 mPa) tension is applied to the plate material, and an image is directly formed on the plate material by an inkjet method in which an oil-based ink is ejected from a recording head by using an electrostatic field based on a signal of image data, and the image is heated. An on-press drawing lithographic printing method, characterized in that a plate is prepared by fixing with a roller, and the plate is used in that state for subsequent lithographic printing. 2. The plate material mounted on the plate cylinder of a printing machine has 0.0
An image is directly formed on the plate material mounted on the plate cylinder of the printing machine based on a signal of image data, and a tension applying means capable of applying a tension of 1 to 100 (kgf / cm ² , × 0,98 mPa). Image forming means, fixing means for fixing the image on the plate material formed by the image forming means by using a heat roller, and lithographic printing for performing lithographic printing with the plate on which the image is fixed by the fixing means. And a recording head for discharging the oil-based ink by utilizing an electrostatic field.