JP2003080664A - On-press drawing planographic printing method and on- press drawing planographic printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate making method for a plate material capable of corresponding to digital image data and capable of printing a large number of printed matters having sharp images inexpensively at a high speed, and a plate making apparatus. SOLUTION: In the on-press drawing planographic printing apparatus 1 equipped with an ink jet drawing apparatus equipped with a recording head for discharging oily ink by utilizing an electrostatic field as an image forming means for directly forming an image on the plate material mounted on the plate cylinder of a printing press on the basis of a signal of image data and a planographic printing means for performing planographic printing on a printing plate having an image formed thereon by the image forming means, a lamp heater 503 and a heat roller 502 are provided to a fixing part 5. A block copy 90 having heat insulating properties and hard to thermally deform is provided on the plate cylinder 11 to mount the plate material 9 on the block copy 90. The block copy 90 to be used has heat insulating properties with a heat conductivity of 0.35 (W/m.K, 30 deg.C) or less and also has a physical property value with a thermal deformation temperature of 65 deg.C or higher.

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 with an oil-based ink and then printing on a printing press. The present invention relates to reduction of energy required for fixing at the time of fixing.

[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 (Comput
er-to-plate) or DDPP (Dig
ital Direct Printing Plating
This is a technology called e). 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.

Conventionally, a heat roller having a heat source has been used alone for fixing, but it is originally difficult to obtain sufficient fixability only with the heat roller, and it is necessary to hold the heat roller at a high temperature for fixing. there were. Therefore, the heat roller portion is significantly deteriorated and its life is short.
In addition, with the recent increase in speed of printing and plate making, the time required for image formation has been shortened, and it has become necessary to perform fixing in a short time. Therefore, a lamp heater has recently been used in combination as a method that can raise the temperature in a short time and does not burden the heat roller. However, it was found that the plate cylinder absorbs heat even when fixing is performed with the plate material mounted on the plate cylinder. Therefore, unless the output of the lamp heater and heat roller is increased, the fixing temperature does not rise, and fixing is performed. It turns out that a defect occurs. Therefore, conversely, if the outputs of the lamp heater and the heat roller are increased in order to ensure the fixing, the life of the heater is shortened and the power consumption is increased.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object thereof is, firstly, a digital-compatible on-press drawing lithographic printing method which does not require development processing. To provide an on-board drawing lithographic printing method and an on-board drawing lithographic printing apparatus capable of performing reliable fixing without increasing outputs of a lamp heater and a heat roller required for fixing in the on-board drawing lithographic printing apparatus. Secondly, it is to provide an on-machine drawing lithographic printing method and an on-machine drawing lithographic printing apparatus capable of printing a large number of clear and high-quality printed matter with an inexpensive apparatus and a simple method.

[0011]

In order to achieve the above object, the invention of the on-press drawing lithographic printing method according to claim 1 is to mount a plate material on a plate cylinder of a printing machine, and to statically form an image on the plate material. By an ink jet method in which an electrostatic ink is discharged from a recording head using an electrostatic field based on a data signal, an image is directly formed to form a printing plate, and the printing plate is used in that state for subsequent lithographic printing. The on-press drawing lithographic printing method is characterized in that a printing plate that is heat-insulating and is not easily deformed by heat is interposed between the plate cylinder and the plate material. According to a second aspect of the present invention, in the on-press drawing lithographic printing method according to the first aspect, the printing plate has a thermal conductivity of 0.35 (W / m · K, 30 ° C) or less. Is characterized in that. According to a third aspect of the present invention, in the on-press drawing lithographic printing method according to the first or second aspect, the plate has a heat distortion temperature of 6
It is characterized by having a value of 5 ° C. or more.
The invention of the on-press drawing lithographic printing apparatus according to claim 4 uses an electrostatic field as an image forming means for directly forming an image on a plate material mounted on a plate cylinder of the printing machine based on a signal of image data. An on-board drawing lithographic printing apparatus comprising an inkjet drawing apparatus having a recording head for ejecting an oil-based ink, and a lithographic printing unit that performs lithographic printing on a printing plate on which an image is formed by the image forming unit, A plate is provided on the plate cylinder that is heat-insulating and is not easily deformed by heat for mounting a material. According to a fifth aspect of the present invention, in the on-press drawing planographic printing apparatus according to the fourth aspect,
The block copy has a thermal conductivity of 0.35 (W / mK, 30 degrees C)
It is characterized by having the following heat insulating properties. According to a sixth aspect of the present invention, in the on-press drawing lithographic printing apparatus according to the fourth or fifth aspect, the master plate has a heat distortion temperature of 65 ° C. or higher. Examples of the plate having a heat conductivity of 0.35 (W / m · K, 30 ° C.) or less and a heat distortion temperature of 65 ° C. or more include, for example, PET (polyethylene terephthalate). , Polyimide, polycarbonate, PEN
Polyester resin such as (polyethylene naphthalate),
Methacrylic resin, ABS resin, ACS resin, acetal resin, ASA resin, chlorinated polyether resin, diallyl phthalate resin, fluororesin, polyarylate, styrene acrylonitrile copolymer, polyurethane, polyether sulfone, polystyrene, polypropylene, polyphenylene sulfide, Polyphenylene oxide, polyamide imide, polyallyl ether, polyptyrene terephthalate, polyamide, phenol resin and the like and materials containing these are used. Moreover, you may use the material reinforced by containing glass fiber in the above materials,
You may use the thing which performed the firing process. As described above, according to the present invention, it is possible to reduce the energy required for fixing at the time of fixing in a digital-compatible on-machine drawing lithographic printing method and on-machine drawing lithographic printing apparatus that do not require development processing, and improve the life of the heater. The fixing can be ensured.

As inventions having other features, the inventions of the following items can be considered. A seventh invention is the on-press drawing lithographic printing method according to claim 1, wherein the oil-based ink is at least at room temperature in a non-aqueous solvent having a specific electric resistance value of 10 ⁹ Ωcm or more and a dielectric constant of 3.5 or less. Is a dispersion of solid and hydrophobic resin particles. As an eighth invention, in the on-press drawing lithographic printing apparatus as described in any one of the above items, the oil-based ink is immersed in a nonaqueous solvent having a specific electric resistance value of 10 ⁹ Ωcm or more and a dielectric constant of 3.5 or less. It is characterized in that it is a dispersion of solid and hydrophobic resin particles at least at room temperature. As a ninth invention, in the on-press drawing lithographic printing apparatus according to any one of the above, the image forming unit removes dust existing on the surface of the plate material before and / or during drawing on the plate material. It is characterized in that a plate material surface dust removing means for removing is provided. As a tenth invention, in the on-press drawing lithographic printing apparatus as described in any one of the above items, the image forming means is configured to rotate the plate cylinder on which the plate material is mounted during drawing on the plate material. The feature is that main scanning is performed. As an eleventh invention, in the on-press drawing lithographic printing apparatus according to any one of the above items, the recording head is a single-channel head or a multi-channel head, and the recording head is used when drawing on the plate material. The sub-scanning is performed by moving in a direction parallel to the axis of the plate cylinder. The twelfth invention is,
In the on-press drawing lithographic printing apparatus as described in any one of the above items, the recording head is a full line head having a length substantially the same as the width of the plate cylinder. First
A third invention is characterized in that, in the on-press drawing lithographic printing apparatus described in any one of the above items, the inkjet drawing apparatus includes an ink supply unit for supplying ink to a recording head. A fourteenth aspect of the invention is an on-press drawing lithographic printing apparatus according to any one of the above aspects, further comprising an ink collecting unit that collects ink from the recording head, and the ink supply unit and the ink collecting unit circulate ink. It is characterized by performing.

A fifteenth aspect of the invention is the on-press drawing lithographic printing apparatus as described in any one of the above aspects, characterized in that an ink stirring means is provided in an ink tank for storing the oil-based ink. A sixteenth aspect of the present invention is the on-press drawing lithographic printing apparatus according to any one of the above aspects, further including an ink temperature control unit for controlling the temperature of the ink in an ink tank that stores the oil-based ink. I am trying. A seventeenth aspect of the invention is characterized in that the on-press drawing planographic printing apparatus according to any one of the above aspects is provided with an ink density control unit that controls the ink density of the ink. An eighteenth aspect of the present invention is the on-press drawing lithographic printing apparatus as described in any one of the above, wherein the inkjet drawing apparatus causes the recording head to approach the plate cylinder when drawing on the plate material. It is characterized in that a recording head separating / contacting means for separating the recording head from the plate cylinder is provided except when drawing on the material. A nineteenth invention is that, in the on-press drawing lithographic printing apparatus as described in any one of the above, the image forming means includes a recording head cleaning means for cleaning the recording head at least after completion of plate making. It has a feature. A twentieth aspect of the invention is the on-press drawing lithographic printing apparatus as described in any one of the above, wherein the lithographic printing means includes paper dust removing means for removing paper dust generated during lithographic printing. I am trying. As described above, according to each invention, an on-board drawing lithographic printing method and an on-board drawing lithographic printing apparatus capable of printing a large number of clear and high-quality image prints with an inexpensive device and a simple method are obtained. To be

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 in FIG.
As shown in FIG. 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. Furthermore, FIG.
Reference numeral 0 is 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 entire construction 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, having one blanket cylinder 12 and one impression cylinder 13,
At least when performing planographic printing, the transfer blanket cylinder 12 is arranged so as to be in pressure contact with the plate cylinder 11, and the printing ink image transferred to the blanket cylinder 12 is transferred to the printing paper P. The impression cylinder 13 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 to enhance wear resistance. On the other hand, it is preferable that the plate cylinder 11 is grounded because it serves as a counter electrode of the recording 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. In this case, known means such as a brush, a leaf spring, and a roller having conductivity can be used.

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.

The fixing device 5 comprises a heat roller 502, a lamp heater 503, and a cleaner 501 for removing dust on the surface of the heat roller 502. Lamp heater 503
Is provided on the upstream side of the heat roller 502. The lamp heater 503 functions to preheat the plate material to a predetermined surface temperature. By heating the plate material to a desired temperature in advance before fixing by the heat roller 502, only the heat roller 502 is heated. Since it is no longer necessary to heat the plate material, the set temperature of the heat roller 502 can be lowered. Although it depends on the material of the heat roller 502, when the set temperature of the heat roller 502 is raised, the rubber material forming the heat roller 502 is deteriorated at an accelerated rate, and the so-called “crying” in which the monomer component or the additive which is the rubber material is eluted. There is a case where the bulge 'occurs. On the other hand, by using the lamp heater 503 together, it is not necessary to set the heat roller 502 to a high temperature, the durability of the heat roller 502 is improved, and the problem of “crying out” is eliminated. Besides, although the bearing of the heat roller 502 may deteriorate when the heat roller 502 is at a high temperature, by using it together with the lamp heater 503, the setting can be lowered and the deterioration of the bearing can be prevented.

When the plate material moves to the fixing portion, it is first heated by the lamp heater 503 and heated. After that, by applying pressure while heating with the heat roller 502, the ink particles on the plate material are pushed into the plate material in a softened or melted state to promote the fixing property. Here, the case where the heating / pressure fixing is performed by the heat roller 502 after the heating by the lamp heater 503 is described.
Even after using the lamp heater 503 after processing 02,
It is possible to provide better fixing property than the case of using the heat roller 502 alone. Further, the heat generation of the heat roller 502 and the lamp heater 503 is controlled by the applied voltage,
The control method is not limited to this.

Although the heat roller 502 is made of Si rubber, a rubber roller made of fluorine or NBR rubber may be used, or another material may be used. Further, the surface of the rubber roller may be covered with a resin sheet having a predetermined thickness (for example, 400 μm). Here, in order to obtain a sufficient fixing property as the nip pressure of the heat roller 502,
0.05 MPa to 250 MPa, more preferably 0.
It is 1 MPa to 20 MPa. Also, the lamp heater 50
Although 3 uses a near infrared lamp heater here, a far infrared lamp heater, a ceramic heater, and a radiant heater can also be applied. Furthermore, it is possible to increase the heating means and use two or more heat rollers and lamp heaters. A block 90 according to the present invention is interposed between the plate cylinder 11 and the plate material 9. As a material used for the block 90, a material having a high heat insulating property and hard to be thermally deformed is preferable. Specifically, in addition to PET (polyethylene terephthalate), polyimide, polycarbonate, PEN
Polyester resin such as (polyethylene naphthalate),
Methacrylic resin, ABS resin, ACS resin, acetal resin, ASA resin, chlorinated polyether resin, diallyl phthalate resin, fluororesin, polyarylate, styrene acrylonitrile copolymer, polyurethane, polyether sulfone, polystyrene, polypropylene, polyphenylene sulfide, Polyphenylene oxide, polyamide imide, polyallyl ether, polyptyrene terephthalate, polyamide, phenol resin and the like and materials containing these are used. Moreover, you may use the material reinforced by containing glass fiber in the above materials,
Those that have been fired are also good. All of these have thermal conductivity of 0.35 (W / m · K, 30 ° C.) or less, and have a thermal deformation temperature of 65 ° C. or more. By interposing this, the lamp heater 503
And without heating the heat roller 502 with high output,
Since the heat is not conducted to the plate cylinder 11 due to the heat insulating property of the plate, the plate material 9 is sufficiently heated and fixed. Therefore, the life of the lamp heater 503 and the heat roller 502 and the tearing of the heat roller 502 due to high output are eliminated.
Further, even if only the heat insulating property is required, if the heat deformation temperature is low, the printing plate is deformed at the time of fixing, which affects the fixing temperature at the time of fixing and the printing pressure at the time of printing, and deteriorates the image quality. Therefore, a material having a heat distortion temperature of 65 ° C. or higher is preferable. Sufficient effect as long as it has a heat conductivity of 0.35 (W / m · K, 30 ° C) or less and a heat distortion temperature of 65 ° C or more Can be expected,
More preferably, the thermal conductivity is 0.3 (W / m · K, 30
If the heat distortion temperature is 80 ° C or higher at a temperature of C) or less, a more sufficient effect can be obtained. In this case, heat insulation and durability are satisfactory, and a good printing plate can be provided for a long period of time.

The thermal conductivity can be measured by the steady absolute method, steady comparison method, hot wire method, hot strip method, time integration method, DS.
C method, quasi-stationary method, Shorader method, probe method, radiation cooling method, flash method, laser flash method, step heating method, improved angstrom method, forced relay scattering method,
Photoacoustic method. There are AC calorimetry method and the like, which can be calculated by appropriately using these methods according to the data. In the examples, the steady absolute method (JIS A14
13 shows the thermal conductivity calculated using 13). On the other hand, the method of measuring the thermal deformation, the cantilever probe method, a thermal deformation method, and a penetration test, the embodiment uses the ASTM test method (D648), for the case of weighted 46 kg / cm ² , Shows the measurement results.

If desired, a plate surface desensitizing device 6 may be installed for the purpose of enhancing the hydrophilicity of the surface of the plate material 9. Further, the printing apparatus 1 removes dust existing on the surface of the plate material before and / or during drawing on the plate material by a plate material surface dust removing means 1
Has 0. As a result, it is possible to effectively prevent the ink from adhering to the plate material through the dust that has entered between the head and the plate material during plate making, and a good plate can be obtained. As the dust removing means, known contact removal methods such as suction removal, blowout removal, electrostatic removal, and the like, and contact methods such as brushes and rollers can be used. In the present invention, either air suction or air blowout is preferable. , Or a combination of them. In this case, the air pump normally used in the paper feeding device can be used for this purpose.

Further, an automatic plate feeder 7 for automatically supplying a plate material 9 for printing onto the plate cylinder 11 and an automatic plate ejecting device 8 for automatically removing the plate material 9 after printing from the plate cylinder 11. May be installed. As a printing machine having this device, which is known as an auxiliary device of the printing machine, for example, Hamada VS3
4A, B452A (Hamada Printing Machinery Co., Ltd.), Toko 8000PFA (Tokyo Aircraft Instrument Co., Ltd.), Ryobi 32
00ACD, 3200PFA (Ryobi Imagisque Co., Ltd.), AMSIS Multi5150FA (Japan AM Co., Ltd.), Oliver 266EPZ (Sakurai Graphic Systems Co., Ltd.), Shinohara 66IV / IVP
(Shinohara Shoji Co., Ltd.) 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 is provided in the vicinity of the impression cylinder 13.
May be installed to prevent paper dust 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.

The image data calculation 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. Furthermore, in order to draw an oil-based ink image in halftone dots using the ink jet recording head 22 (see FIG. 2, which will be described later in detail) as a recording head of the ink jet recording device 2, the halftone dot area ratio is also calculated. .

Further, as will be described later, the image data calculation control unit 21 controls the movement of the ink jet recording head 22 and the ejection timing of the oil-based ink, and at the same time, the plate cylinder 11, the blanket cylinder 12, and the impression cylinder 13 are required. It also controls the operation timing such as.

A plate making process by the printing apparatus 1 will be described below with reference to FIGS.

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 In particular,
For example, there is a method of arranging a pressing roller upstream and downstream of the plate cylinder drawing position. Further, by providing a 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 the plate surface from being soiled and reduce the 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 recording head 22 close to a position close to the plate cylinder 11 by a head separating / contacting device (recording head separating / contacting unit) 31. The distance between the recording head 22 and the surface of the plate material 9 placed on the plate cylinder 11 through the plate 90 is controlled by a mechanical distance such as an abutting roller, or the head is separated or contacted by a signal from an optical distance detector. It is kept at a predetermined distance during drawing by the control of the device.
By this distance control, the dot diameter does not become non-uniform due to floating of the plate material or the like, and the dot diameter does not change especially when vibration is applied to the printing machine, and a good plate can be obtained.

A single-channel head, a multi-channel head, or a full-line head can be used as the recording 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 direction parallel to the axis of the plate cylinder, and the oil-based ink is discharged onto the plate material 9 mounted on the plate cylinder 11 through the plate 90 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 recording 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 recording head 22,
The recording head 22 is retracted away from the position close to the plate cylinder 11. At this time, only the recording head 22 may be separated and contacted, but the recording head 22 and the head sub-scanning unit 32 may be separated and contacted together, or the recording 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 recording head 22, the ink supply unit 24, and the head sub-scanning unit 32, the fixing device 5 and the dust removing unit 10 are also provided with contacting and detaching units so that they can be retracted, so that normal printing can be supported.

The separating / contacting 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.

Further, the formed oil-based ink image is reinforced by heating in the fixing device 5 described above. In addition, at least in the process from the formation of the oil-based ink image by the recording head 22 to the fixing by the fixing device 5, the dampening water supply device 3,
It is desirable that the printing ink supply device 4 and the blanket cylinder 12 be kept out of contact with the plate material 9 on the plate cylinder.

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 12 rotating with the plate cylinder 11. Then, the printing ink image on the blanket cylinder 12 is transferred onto the printing plate material P passing between the blanket cylinder 12 and the impression cylinder 13 to perform printing for one color. Plate material 9 after printing
Are removed from the plate cylinder 11 by the automatic plate discharging device 8, and the blanket on the blanket cylinder 12 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 recording head. In this case, the ink supply unit 24 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. 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 preferably 15 ° C. or higher and 60 ° C. or lower, 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 managing by physical property measurement, an optical detector, an electric conductivity measuring instrument, a clay measuring instrument are provided individually or in combination in the ink tank or the ink flow path, and the ink concentration is determined by the output signal. Control and also
When the management is performed 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 depending on the number of plates and the frequency.

As described above, the image data calculation control unit 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 recording 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 the digital signal of the image pattern.
As shown in FIG. 3, a plate cylinder 11 serving as a counter electrode is installed so as to face the ejection electrode 22b, and the plate material 9 is provided on the plate cylinder 11 serving as a counter electrode via a plate 90. Has been. By applying a voltage, a circuit is formed between the ejection electrode 22b and the plate cylinder 11 serving as a counter electrode, and the head 2
The oil-based ink 23 is discharged from the two discharge slits 22a, and an image is formed on the plate material 9 provided on the plate cylinder 11 serving as a counter electrode through the plate 90.

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 respectively a schematic cross-sectional view and a schematic front view of the vicinity of the ink ejection portion of another example of the recording head. In the figure, reference numeral 22 denotes a recording head, and the recording 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 section is required, a groove 40 may be provided between the ejection section and the ink recovery passage. FIG. 6 is a schematic front view of the vicinity of the ink ejection portion of the recording head, and the ink recovery path 3 is formed on the slope of the second insulating substrate 34 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 recording head used to carry 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 main body 41 is provided with a plurality of ink grooves 43 for circulating ink perpendicularly to the edge of the head main 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 tip of the discharge part may be slightly chamfered like 45 '. Although only two cells are shown in the figure,
The cells are separated from each other by a partition wall 46, and the tip end portion 47 thereof is chamfered so as to be retracted more than 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 recording head will be described with reference to FIG. As shown in FIG. 9, the recording head 2
2 has a pair of support members 50 and 50 'having a substantially rectangular plate shape. These supporting members 50, 50 'are formed 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 according to 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. The respective support members 50, 50 'are combined so that the surfaces not forming the grooves 51, 51' face each other. That is, the recording head 22 has a plurality of grooves on the outer peripheral surface for circulating the ink. The grooves 51, 51 'formed in each support member 50, 50' are connected in a one-to-one correspondence via the rectangular portion 54 of the recording head 22, and the rectangular portion 54 in which each groove is connected is recorded. 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 in the recording 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 recording head 22 is inclined at a predetermined angle in order to enable smooth ink circulation. That is, the recording 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 the ink is circulated in the recording 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,
By applying a voltage to the discharge electrode 22b based on image information with respect to a plate cylinder (not shown) having a plate material held on the surface thereof so as to face the discharge portion, ink is discharged from the discharge portion onto the plate material. 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 recording 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 recording 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.

Next, 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 four-color single-sided lithographic printing apparatus basically has the plate cylinder 11, the blanket cylinder 12, and the impression cylinder 13 of the single-color single-sided printing apparatus shown in FIG. 1 on the same surface of the printing plate material P. It has a structure having four of each so that printing is performed.
Although not shown, a known transfer cylinder method or the like is used to transfer the printing plate material indicated by K in the drawing between the adjacent impression cylinders. Although a detailed description is omitted, as can be easily understood from the example of FIG. 10, the other multi-color single-sided printing devices basically use the plate cylinder 11, the blanket cylinder 12, and the impression cylinder 13 of the single-color single-sided printing device as the printing plate material P. It has a structure in which a plurality of plates are provided so that printing is performed on the same surface. When only one color plate is prepared on the plate cylinder, 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 plate material between the adjacent common impression cylinders.

On the other hand, when a plurality of color plates are prepared on the plate cylinder, the plate cylinder and the blanket cylinder are required by the number of colors to be printed divided by the number of plates 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, the impression cylinder is equipped with a means to hold the printing plate material until the printing of the required colors is completed, and a known transfer cylinder method is used to transfer the printing plate material between the impression cylinders. To do. In the case of a printing machine having two plate cylinders and two blanket cylinders for which the plate materials for the above two colors are created, one impression cylinder holds the printing plate material and rotates two times to perform two-color printing. The printing plate material is transferred between the impression cylinders, and then the other impression cylinder holds the printing plate material and makes two revolutions to perform two-color printing, thereby completing four-color printing. 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 plate material reversing means is provided between at least one adjacent impression cylinder of the above-mentioned unit type printing apparatus. Either the structure or the structure in which a plurality of common impression cylinder type printing devices described above are arranged and a known printing plate material reversing means is provided between at least one adjacent impression cylinders, or the plate cylinder 11 of the single-color single-sided printing device shown in FIG. The blanket cylinder 12 has a plurality of structures so that both sides of the printing plate material P can be printed. 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 plate material. 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 plate material until printing of the required color 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.

The example of the sheet-fed printing apparatus has been described above as the embodiment of the on-press drawing multicolor planographic 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, a printing plate. This can be achieved by a structure having a plurality of members so that printing is performed on both sides of the material 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. Examples of the printing original plate include metal plates such as aluminum and a chrome-plated steel plate. In particular, an aluminum plate having excellent surface water retention and abrasion resistance by graining or anodizing treatment is preferable. As a cheaper plate material, a plate material having an image receiving layer provided on a water resistant support such as paper to which water resistance is imparted, a plastic film, or a 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.

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.
As the binder, hydrophilic binders such as polyvinyl alcohol, starch, carboxymethyl cellulose, hydroxyethyl cellulose, casein, gelatin, polyacrylic acid salt, polyvinyl pyrrolidone, polymethyl ether-maleic anhydride copolymer and the like 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.

The zinc oxide to be used in the present invention is, for example, as described in “New Edition Pigment Handbook” edited by Japan Pigment Technology Association, page 319, Seibundou Co., Ltd. (published in 1968), zinc oxide, zinc white, Any of those commercially available as wet zinc white or activated zinc white may be used. That is, depending on the starting material and the manufacturing method, there are zinc oxides known as the French method (indirect method), the American method (direct method) and the wet method, for example, Shodo Kagaku Co., Ltd., Sakai Kagaku Co., Ltd. ), Hakusui Chemical Co., Ltd., Honjo Chemical Co., Ltd., Toho Zinc Co., Ltd., Mitsui Kinzoku Kogyo 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. Conventionally, as this type of desensitizing treatment liquid, 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 smoothed and decompressed. It measures the time required for a fixed amount (10 cc) of air to pass between the glass surface and the test piece below.

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. These non-aqueous solvents are used alone or as a mixture with other solvents as a cleaning liquid.

The reason why the electric resistance of the non-aqueous solvent used is within the above range is that when the electric resistance is low, concentration of resin particles and the like is less likely to occur, and sufficient printing durability cannot be obtained. The reason for setting the above range is that when the permittivity becomes high, the electric field is relaxed by the polarization of the solvent, which easily deteriorates the ejection of the ink.

The resin particles to be 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 portion 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 entire ink. When the content is low, the affinity between the ink and the surface of the printing original plate is difficult to be obtained, and a good image cannot be obtained, or the printing durability is likely to deteriorate. When the amount is large, it becomes difficult to obtain a uniform dispersion liquid, and the ink flow in the recording 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 pigment, phthalocyanine pigment. , 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 dye, an azo dye, a metal complex salt dye,
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 the non-aqueous solvent as the coloring materials themselves as the 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 the resin particles dispersed in the non-aqueous solvent of the present invention and further colored particles is preferably 0.05 μm to 5 μm. It is more preferably 0.1 μm to 1.0 μm, still more preferably 0.1 μm.
It is in the range of μm to 0.5 μm. This particle size is CAPA-
500 (trade name, manufactured by HORIBA, Ltd.).

The non-aqueous dispersion resin particles used in the present invention can be produced by a conventionally known mechanical pulverization method or polymerization granulation method. As 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, which are used in combination with a dispersion polymer, and further a wet dispersion machine (for example, ball mill / paint shaker). , Keddy 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, specifically, Soichi Muroi's "Latest Technology of Ultrafine Particle Polymer", 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 "Dispers
ion Polymerization in Organic Media '' John Wiley (19
(75 years) etc.

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 .

A preferred soluble repeating unit of the dispersion polymer used in the present invention is a polymerization component represented by the following general formula (1).

[0081]

[Chemical 1]

In the general formula (I), X ₁ 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. .

A ₁ and a ₂ may be the same or different from each other, and 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). Group, ethyl group, propyl group, etc.),
-COO-Z1 or -CH ₂ COO-Z1 [Z
1 represents an optionally substituted hydrocarbon group having 22 or less carbon atoms (for example, an alkyl group, an alkenyl group, an aralkyl group, an alicyclic group, an aryl group, etc.).

Among the hydrocarbon groups represented by Z1, preferred hydrocarbon groups include 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 having 7 to 12 carbon atoms which may be substituted (eg, benzyl group, phenethyl group, 3-phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group, chlorobenzyl group, bromobenzyl group, methylbenzyl group, An ethylbenzyl group, a methoxybenzyl group, a dimethylbenzyl group, a dimethoxybenzyl group, etc.), an alicyclic group having 5 to 8 carbon atoms which may be substituted (eg, a cyclohexyl group, 2
-Cyclohexylethyl group, 2-cyclopentylethyl group and the like), 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, propioamidophenyl group, dodecyloylamidophenyl group and the like).

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 the 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"
139-148, "Basics and Applications of Electrophotography" edited by The Institute of Electrophotography, 497-505 (Corona Publishing Co., Ltd., 1988), Yuji Harasaki "Electrophotography" 16 (No. 2), 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.

[0090]

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. while 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.).

[0092]

[Chemical 2]

A part of the white dispersion was subjected to a centrifuge (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 ℃.

Example 1 First, an oil-based ink was 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. Example 1 First, an oil-based ink was prepared. <Preparation of oil-based ink (IK-1)> 10 g of dodecyl methacrylate / acrylic acid copolymer (copolymerization ratio; 95/5 weight ratio), nigrosine 10 g, and shell sol 7
30 g of 1 was put into a paint shaker (manufactured by Toyo Seiki Co., Ltd.) together with glass beads 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) A black oil-based ink was prepared by diluting 15 g of alcohol) and 0.08 g of octadecene-half-maleic acid octadecylamide copolymer to 1 liter of Isopar G.

Next, the on-press drawing planographic 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 recording head 900 shown in FIG.
A 64-channel multi-channel head of dpi was used, and a piezoelectric pump was used for feeding the ink. A throw-in heater and a stirring blade 71 (Ramon Stirrer (model number ST02) manufactured by Tokai Riki Co., Ltd.) are provided in the ink tank 25 as an ink temperature control means, and the ink temperature is set to 30 ° C.
The temperature was controlled by a thermostat while rotating the stirring blade 71 at 30 rpm. Further, the ink flow path is made partially transparent, and the LED light emitting element and the light detection element are arranged so as to sandwich the ink flow path, and the output signal from the LED diluting solution (Isopar G) or the concentrated ink (the solid of the ink (IK-1) above). The concentration was adjusted by doubling the concentration).

As a plate material, an aluminum plate having a graining and anodizing treatment and having a thickness of 0.12 mm was attached by holding a plate head and a plate butt by a mechanical device provided on a plate cylinder. Separate the dampening water supply device, printing ink supply device, and blanket cylinder so that they do not contact the plate material, remove dust from the surface of the plate material by suction with an air pump, and then bring the recording head close to the plate material to the drawing position for printing. The image data to be transmitted was transmitted to the image data calculation control unit, and the 64-channel recording head was moved while rotating the plate cylinder, whereby the oil-based ink was ejected onto the aluminum plate to form an image. At this time, the tip width of the ejection electrode of the inkjet head is 10 μm.
m, and according to the output from the optical gap detection device,
Control was performed so that the distance between the head and the plate material was always 1 mm. A voltage of 2.5 kV is always applied as a bias voltage, and when discharging, a pulse voltage of 500 V is further superimposed and the pulse voltage is changed from 0.2 ms to 0.0
Drawing was performed while changing the dot area by changing the scale in 256 steps within a range of 5 milliseconds. In order to protect the inkjet head, the inkjet recording device together with the sub-scanning means is retracted 50 mm from the position close to the plate cylinder,
Then, as described above, printing was performed on the printing coated paper by the usual lithographic printing method. That is, printing ink and fountain solution are applied to form a printed image, the printed ink image is transferred onto a blanket cylinder rotating with the plate cylinder, and then a printing coat passing between the blanket cylinder and the impression cylinder. The printed ink image on the blanket cylinder was transferred onto the paper.

Further, in fixing, a halogen lamp irradiation (QIR manufactured by Ushio Inc., power consumption 1.5 kW) is performed, and then an image is formed by heat roller fixing (power consumption 1.2 Hitachi manufactured by Hitachi Metals, Ltd.). Firm and made a printing plate. PET (polyethylene terephthalate) having the physical properties shown in Table 1 was used as the block. That is, the thermal conductivity (W / m · K, 30 ° C) is 0.2 and the thermal deformation temperature is 2
A master block at 00 ° C was used. As a result, the temperature of the plate material surface was 100 ° C., no defective fixing was observed, and the evaluation result of printing durability was good. In addition, plate making and printing are repeated,
Deformation occurred in the plate after the number of plate making reached 20 or more, which was not a problem in practical use. Furthermore, the temperature of the outside air,
Even with an increase in the number of plate making, no image deterioration due to dot shape change was observed, and good plate making was possible.

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, 10 minutes after the completion of plate making, Isopar G is applied to the head.
Is supplied to the head opening for cleaning, and then the head is stored in a cover filled with vapor of Isopar G for 3 months.
Good printed matter could be produced without the need for maintenance work. When a 600 dpi full line inkjet head of the type shown in FIGS. 4, 7 and 9 was used in the same manner in place of the inkjet head of the type shown in FIG. 3, the same good results as above were obtained. It was

[0100]

[Table 1]

Example 2 A polyimide having the physical properties shown in Table 1 was used as a block.
That is, the thermal conductivity (W / mK, 30 degrees C) is 0.1
6 is under the condition of a polyimide plate having a heat distortion temperature of 200 ° C. or higher. Others were the same as in Example 1. The temperature reached on the surface of the plate material was 108 ° C., and the number of plate making that caused deformation was 20 or more. Therefore, the evaluation result of printing durability was good. The temperature reached on the surface of the plate material was 108 ° C., no fixing failure was observed, and the evaluation result of printing durability was good. Also, plate making and printing are repeated. Deformation occurred in the plate after the number of plate making reached 20 or more, which was not a problem in practical use. Further, even if the temperature of the outside air and the number of plate-making were increased, the image deterioration due to the dot shape change was not observed at all, and the excellent plate-making was possible.

Example 3 A polycarbonate having the physical properties shown in Table 1 was used as a master. That is, it is under a polycarbonate plate having a thermal conductivity (W / m · K, 30 ° C.) of 0.28 and a heat distortion temperature of 130 ° C. or higher. Others were the same as in Example 1.
The temperature reached on the surface of the plate material was 88 ° C., no fixing failure was observed, and the evaluation result of printing durability was good. Also, plate making,
Printing was repeated, and the number of plate making was 16
It was only after the number of sheets, and there was no problem in practical use. Furthermore,
Even when the temperature of the outside air and the number of plate making increased, image deterioration due to dot shape change was not observed at all, and good plate making was possible.

Comparative Example 1 Polyethylene having the physical properties shown in Table 1 as a block (low density)
Was used and the same as in Example 1 was carried out. That is, the composition has a thermal conductivity (W / m · K, 30 ° C) of 0.35.
It is made of polyethylene with a heat distortion temperature of 45 ° C or higher.
The temperature reached on the surface of the printing plate was 78 ° C, and there were some areas that seemed to be defective in fixing. However, plate making and printing were repeated, and the master block was deformed with only one plate making, which became a practical problem. Although the result of printing durability was satisfactory, it was difficult to use the plate of Comparative Example 1 because the plate was easily deformed.

Comparative Example 2 The same procedure as in Example 1 was carried out except that no block was used. The temperature reached on the surface of the plate material did not rise so much and remained at 60 ° C. There were many areas where the fixing was not good, and the plate making was not good.

Comparative Example 3 Polyethylene having the physical properties shown in Table 1 as a block (high density)
It was used. Specifically, the thermal conductivity (W / mK, 30
The degree C) is 0.35, and it is made of polyethylene with a heat distortion temperature of 65 ° C or higher. Others were the same as in Example 1. The temperature reached on the surface of the plate material was 72 ° C., and there were some areas where fixing was defective. The evaluation result of printing durability was slightly inferior, and although it was practically light, it was at a level that caused a problem. Further, plate making and printing were repeated, and the master plate was deformed when the number of plate making was 5, and although it was easily deformed, it did not pose a practical problem. Although the deformation of the block is not a problem, the printing durability is not satisfactory, and it is difficult to use the block of Comparative Example 3.

Comparative Example 4 The same procedure as in Example 1 was carried out except that an iron plate having the physical properties shown in Table 1 was used as a printing plate. The used artwork has a thermal conductivity (W /
m · K, 30 ° C) is 650, and heat distortion temperature is 200 ° C.
It is made of iron. The temperature reached on the surface of the plate material was 63 ° C., and there were some areas where fixing was defective. On the other hand, plate making and printing were repeated, and no deformation was observed even when the number of plate making was 20, and there was no problem. Although the deformation of the block is not a problem, the printing durability is not satisfactory, and it is difficult to use the block of Comparative Example 4. Comparative Example 5 The same procedure as in Example 1 was carried out except that vinyl chloride shown in Table 1 was used as the master plate. The used artwork has a thermal conductivity (W /
m ・ K, 30 ° C) is 0.25 and heat distortion temperature is 60 °
It is C. The temperature reached on the surface of the plate material was 96 ° C., no fixing failure was observed, and the evaluation result of printing durability was good. However, the platemaking and printing were repeated, and the deformation of the printing plate occurred only when the number of platemaking was two, which was a problem in practical use.

As a result of the above, it has been made clear that, in the case of a fixing device of a type that uses both a heat roller and a lamp heater, it is preferable to interpose a master plate between the plate cylinder and the plate material. It is also preferable that the material used for the master block is one having high heat insulation and high tensile strength. Specifically, PET, polyimide,
Polycarbonate etc. are good. All of these have thermal conductivity of 0.35 (W / m · K, 30 ° C.) or less and high tensile strength of thermal deformation temperature (65 ° C.) or more. By interposing this, even if the lamp heater and the heat roller are not heated at a high output, the heat is not conducted to the plate cylinder due to the heat insulation of the plate, so that the plate material is sufficiently heated and fixed. It was

[0108]

According to the present invention, it is possible to print a large number of printed matters having clear images. In addition, a printing plate directly corresponding to digital image data can be stably produced with high image quality on a printing machine, and inexpensive and high-speed lithographic printing can be performed. further,
By providing a plate on the plate cylinder that is heat-insulating and that is not easily deformed by heat, it is possible to reduce the energy required for fixing during fixing, extend the life of the heater, and ensure high-quality high-quality printing plates. Can be created.

[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 501 Heat roller surface cleaner 502 heat roller 503 lamp heater 6 Plate desensitizing device 7 Plate material automatic plate feeder 8 Automatic plate discharge device 9 Plate material (printing original plate) 10 Dust removal means 11 plate cylinder 12 blanket torso 13 impression cylinder 14 Blanket cleaning device 14 'impression cylinder cleaning device 15 Paper dust generation prevention device 21 Image data calculation controller 22 recording 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 '(discharging section 46 partitions 47 Partition tip 50, 50 'support member 51, 51 'groove 52 partition 53 Upper end 54 rectangle 55 Top of partition 56 Guide protrusion 90 version

Claims (6)

[Claims] 1. An image is directly formed by an ink jet system in which a plate material is mounted on a plate cylinder of a printing machine, and an oil-based ink is ejected from a recording head by utilizing an electrostatic field based on a signal of image data on the plate material. In the on-press drawing lithographic printing method, in which the printing plate is prepared in this state, and the printing plate is used in that state for subsequent lithographic printing, the plate cylinder and the plate material are heat-insulating and are not easily thermally deformed. An on-press drawing planographic printing method characterized by interposing a block copy. 2. The master block has a thermal conductivity of 0.35 (W / m.multidot.m).
The on-press drawing lithographic printing method according to claim 1, which has a heat insulating property of K, 30 degrees C) or less. 3. The on-press drawing lithographic printing method according to claim 1, wherein the master block has a heat distortion temperature of 65 ° C. or higher. 4. An ink jet equipped with a recording head for ejecting an oil-based ink by using an electrostatic field as an image forming means for directly forming an image on a plate material mounted on a plate cylinder of a printing machine based on a signal of image data. In an on-board drawing lithographic printing apparatus comprising a drawing device and lithographic printing means for performing lithographic printing on a printing plate on which an image has been formed by the image forming means, the plate is heat-insulating and resistant to thermal deformation. An on-press drawing lithographic printing apparatus characterized by being provided on the body. 5. The master block has a thermal conductivity of 0.35 (W / m ·
The on-press drawing lithographic printing apparatus according to claim 4, which has a heat insulation property of K, 30 degrees C or less. 6. The on-press drawing lithographic printing apparatus according to claim 4, wherein the plate has a heat distortion temperature of 65 ° C. or higher.