JP2001171071A - Method and apparatus for on-press imaging lithographic printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for lithographic printing capable of dealing with digital image data and printing a large number of printed products having clear images at a high speed and a low cost. SOLUTION: The method for on-press imaging lithographic printing comprises the steps of mounting a plate material on a plate cylinder of a printer, directly forming an image in an ink jet type for discharging an oil based ink by utilizing an electrostatic field based on a signal of image data on the material to form a press plate, and subsequently lithographic printing is carried out by using the material in its state. In this method, when a fault occurs, the direct image forming is stopped and/or the cause of the fault is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a lithographic printing method and a printing apparatus for performing digital plate making on a printing press.
More specifically, the present invention relates to a plate making / printing method and a printing apparatus which perform printing after performing plate making with an oil-based ink and have good plate making quality and print quality.

[0002]

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

Recording of image on printing plate (plate material) (plate making)
Prints an image original in analog or digital form on a silver halide photographic film, and then exposes a diazo resin or photopolymerizable photopolymer photosensitive material (printing master) through it.
It is a general method to perform elution and removal of the non-image area mainly using an alkaline solution.

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

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

Further, as a means for improving the efficiency of the printing process, there is a system for performing image drawing on a printing press. Although there is a method using the above laser, it is expensive and large. Therefore, a system using an inkjet method, which is an inexpensive and compact drawing apparatus, has been attempted.

In Japanese Patent Application Laid-Open No. Hei 4-97848, a plate drum having a hydrophilic or lipophilic surface is provided in place of the conventional plate cylinder, and a lipophilic or hydrophilic image is formed thereon by an ink jet method. A method is disclosed in which the image is formed, the image is removed after printing, and the image is cleaned. However, in this method, it is difficult to achieve both removal of a printed image (that is, ease of cleaning) and printing durability. In addition, in order to form a print image having high printing durability on a plate cylinder, it is necessary to use ink containing a relatively high concentration of resin. As a result, the adhesion of the resin tends to occur, and the stability of ink ejection is low. As a result, it is difficult to obtain a good image.

Japanese Patent Application Laid-Open No. 64-27953 discloses a method of performing plate making by drawing using an lipophilic wax ink on a hydrophilic plate material by an ink jet method. In this method, since the plate material is disposable, there is no need to remove the image after printing, and the ejection stability is high, but the mechanical strength of the image portion is weak because the image is formed by wax, In addition, the printing durability is low due to insufficient adhesion to the plate material hydrophilic surface.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to firstly provide a digitally compatible on-press lithographic printing method which does not require development processing. To provide. Secondly, it is an object of the present invention to provide a lithographic printing method and a printing apparatus capable of printing a large number of clear and high-quality images using an inexpensive apparatus and a simple method.

[0010]

According to a first aspect of the present invention, there is provided a lithographic printing method comprising the steps of: mounting a plate on a plate cylinder of a printing press; In the on-press drawing lithographic printing method, a plate is created by directly forming an image by an ink jet method of discharging oil-based ink using an electrostatic field based on the signal of the plate material, and subsequently performing lithographic printing using the plate material in that state. When an abnormality occurs, the image formation is directly stopped and / or the cause of the abnormality is removed. The lithographic printing method according to claim 2, wherein the oil-based ink has solid and hydrophobic resin particles dispersed 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. Characterized in that:

According to a third aspect of the present invention, there is provided an on-press lithographic printing apparatus comprising:
An ink jet drawing apparatus for discharging oil-based ink using an electrostatic field as a direct image forming means for forming an image directly on a plate material mounted on a plate cylinder of a printing press based on a signal of image data; An on-press drawing printing apparatus having a planographic printing means for performing lithographic printing with a printing plate formed by the means, comprising an abnormality detecting means and / or an abnormal cause removing means, and at least temporarily receiving an output from the abnormality detecting means. (1) directly stopping the image forming means and / or activating the abnormality cause removing means. According to a fourth aspect of the present invention, there is provided an on-press lithographic printing apparatus comprising a recording head foreign matter adhesion detecting device for detecting foreign matter adhesion to a recording head of the ink jet drawing device as the abnormality detecting means. The on-press drawing lithographic printing apparatus according to claim 5, further comprising a dust detection device for detecting dust in the on-press drawing lithographic printing apparatus and / or on the plate material, as the abnormality detecting means. . According to a sixth aspect of the present invention, there is provided an on-press drawing lithographic printing apparatus, wherein the on-press drawing lithographic printing apparatus and / or a vibration detecting device for detecting vibration of the recording head are provided as the abnormality detecting means. 8. The on-press lithographic printing apparatus according to claim 7, wherein the oil-based ink is a resin particle which is solid and hydrophobic at least at room temperature in a non-aqueous solvent having a specific electric resistance of 10 ⁹ Ωcm or more and a dielectric constant of 3.5 or less. Are dispersed. An on-press lithographic printing apparatus according to claim 8 is provided with the ink fixing device. 10. The on-press lithographic printing apparatus according to claim 9, wherein the direct image forming means includes plate material surface dust removing means for removing dust present on the plate material surface before and / or during drawing on the plate material. It is characterized by having. Claim 10
The on-press lithographic printing apparatus described above is characterized in that, when drawing on the plate material, the direct image forming means performs main scanning by rotating a plate cylinder on which the plate material is mounted. (11) The ink jet drawing apparatus includes a single head or a multi-head, and performs sub-scanning by moving the recording head in the axial direction of the plate cylinder when drawing on the plate material. A lithographic printing apparatus according to a twelfth aspect of the present invention is characterized in that the inkjet drawing apparatus includes a full line head having substantially the same length as the width of the plate cylinder. An on-press lithographic printing apparatus according to claim 13,
The inkjet drawing apparatus includes an ink supply unit that supplies ink to the recording head. The on-press lithographic printing apparatus according to claim 14, further comprising an ink recovery unit configured to recover ink from the recording head,
The ink is circulated by the ink supply means and the ink recovery means. An on-press lithographic printing apparatus according to a fifteenth aspect is characterized in that an ink stirring means is provided in an ink tank for storing the oil-based ink.
An on-press lithographic printing apparatus according to a sixteenth aspect of the present invention is characterized in that an ink temperature control means for controlling the temperature of the ink in an ink tank storing the oil-based ink is provided. An on-press lithographic printing apparatus according to a seventeenth aspect is characterized in that the lithographic printing apparatus further comprises an ink density control unit for controlling the ink density of the ink. The on-press lithographic printing apparatus according to claim 18, wherein the inkjet drawing apparatus brings the recording head close to the plate cylinder when drawing on the plate material, and moves the recording head except when drawing on the plate material. A recording head detaching unit for detaching the recording head from the plate cylinder; The on-press lithographic printing apparatus according to claim 19 is characterized in that the direct image forming means includes a recording head cleaning means for cleaning the recording head at least after the completion of plate making. According to a tenth aspect of the present invention, in the lithographic printing apparatus, the lithographic printing means includes a paper dust removing means for removing paper dust generated during lithographic printing.

[0012]

Embodiments of the present invention will be described below in detail. The present invention is characterized in that an image is formed on a plate material (printing original plate) provided on a plate cylinder of a printing press by an inkjet method in which oil-based ink is discharged by an electrostatic field.

The ink jet method according to the present invention uses a PC
In the ink jet method, an ink having high resistance in which solid and hydrophobic resin particles are dispersed at least at room temperature in an insulating solvent is used. By applying a strong electric field at the discharge position, an aggregate of the resin particles is formed at the discharge position, and the aggregate is discharged from the discharge position by electrostatic means. In this way, the resin particles are ejected as agglomerates having a high concentration, and the thickness of the printed dots is sufficiently obtained. As a result, an image of the aggregated resin particles having sufficient printing durability is formed on the plate material as the recording medium. In addition, in the inkjet method, the size of the ejected ink droplet is determined by the ejection position, the shape of the electrode, and the conditions for applying an electric field. By controlling the conditions, the dot diameter on the plate material can be controlled. Therefore, according to the present invention, it is possible to control printing-resistant minute images without the problem of ink clogging of the head.
Provided is a lithographic printing method and a printing apparatus capable of printing a large number of clear printed images.

An example of the configuration of an on-press lithographic printing apparatus used for carrying out the lithographic printing method of the present invention will be described below.

FIG. 1 is an overall configuration diagram of an on-press drawing single-color single-sided lithographic printing apparatus. FIG. 2 is a schematic configuration example of a drawing unit including a control unit, an ink supply unit, and a head separation / contact mechanism of the on-board drawing lithographic printing apparatus. FIGS. 3 to 9 correspond to FIGS.
This is for describing an ink jet recording apparatus included in the on-press lithographic printing apparatus No. 0. FIG. 10 is an overall configuration example of an on-press drawing four-color single-sided lithographic printing apparatus according to the present invention. FIG. 11 is a diagram illustrating an example of a method of detecting an abnormal current to the head, an image quality defect, and a meniscus shape abnormality, and FIG. 12 is a diagram illustrating an example of a dust detection unit using an optical detection method.

First, the printing process according to the present invention will be described with reference to the overall configuration diagram of an on-press drawing single-color single-sided lithographic printing press shown in FIG. As shown in FIG. 1, an on-press lithographic printing apparatus 1 (hereinafter, also simply referred to as a “printing apparatus”) includes a plate cylinder 1.
1, having one blanket cylinder 12 and one impression cylinder 13;
At least when performing lithographic printing, a blanket cylinder 12 for transfer is arranged so as to press against the plate cylinder 11, and the blanket cylinder 12 is used to transfer the printing ink image transferred to the blanket cylinder 12 to the printing paper P. The impression cylinder 13 is arranged so as to be in pressure contact with the impression cylinder 13.

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

Further, the printing apparatus 1 has an ink jet recording (drawing) apparatus 2, whereby the plate mounted on the plate cylinder 11 corresponding to the image data sent from the image data arithmetic control unit 21. An image is formed by discharging oil-based ink on the material 9.

Further, the printing apparatus 1 is provided with a dampening water supply device 3 for supplying dampening water to a hydrophilic portion (non-image portion) on the printing plate 9. FIG. 1 shows a Molton water supply system as a representative example of the dampening water supply device 3. However, as the dampening water supply device 3, other known devices such as a synflo water supply system and a continuous water supply system can be used. Further, the printing device 1
The printing apparatus includes a printing ink supply device 4 and a fixing device 5 for strengthening an oil-based ink image drawn on the plate material 9.
If necessary, a plate surface desensitizing device 6 may be provided for the purpose of enhancing the hydrophilicity of the surface of the plate material 9. Further, the printing apparatus 1 has a unit 10 for removing dust existing on the surface of the plate material before or / and during the drawing on the plate material. As the dust removing means, in addition to a known non-contact method such as suction removal, blowing removal, and electrostatic removal, a contact method using a brush, a roller, or the like can be used. Or a combination thereof. In this case, an air pump usually used for a paper feeding device can be used for this purpose.

Further, an automatic plate feeding device 7 for automatically supplying a plate material 9 to be printed onto the plate cylinder 11 and an automatic plate discharging device 8 for automatically removing the plate material 9 after printing from the plate cylinder 11 May be installed. A printing press having this device, which is known as an auxiliary device for a printing press, is, for example, Hamada VS
34A, B452A (Hamada Printing Machinery Co., Ltd.), Toko 8000 PFA (Tokyo Aviation Instruments, Inc.), Ryobi 3
200 ACD, 3200 PFA (Ryobi Magicsk), AMSIS Multi5150FA (AEM), Oliver 266EPZ (Sakurai Graphic Systems), Shinohara 66IV / IVP (Shinohara Shoji) and the like. Further, a blanket cleaning device 14 and an impression cylinder cleaning device 14 'may be provided. By using these devices 7, 8, and 14, the printing operation becomes easier and the printing time is shortened, so that the effects of the present invention can be further enhanced. Further, a paper dust generation preventing device 15 may be provided near the impression cylinder 13, so that powder adhering to the plate material can be prevented. As the paper dust generation preventing device 15, a method such as humidity control, suction by air or electrostatic force, or the like can be used.

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

As will be described later, the image data calculation control unit 21 controls the movement of the ink jet head 22 and the ejection timing of the oil-based ink, and, if necessary, the plate cylinder 11, blanket cylinder 12, impression cylinder 13 and the like. The operation timing is also controlled.

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

First, the plate material 9 is mounted on the plate cylinder 11 using the automatic plate feeding device 7. At this time, the plate material is closely fixed on the plate cylinder by a mechanical method using a known plate head / butt holding device, an air suction device, or the like, or an electrostatic method. Inkjet recording device 2
It can be prevented from being damaged due to contact with. 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 this is applied at least when drawing is performed, thereby preventing the plate material from contacting the ink jet recording apparatus. Can also. In particular,
For example, there is a method of disposing a pressing roller upstream and downstream of the plate cylinder drawing position. Also, in the process of fixing the plate,
By providing a means for preventing the edge of the plate from contacting the ink supply roller, it is possible to prevent the plate surface from being stained and reduce waste paper. Specifically, a pressing roller, a guide, electrostatic attraction, or the like is effective.

Image data from a magnetic disk device or the like
The image data arithmetic control unit 21 calculates the discharge position of the oil-based ink and the halftone dot area ratio at that position in accordance with the input image data. These calculation data are temporarily stored in the buffer. The image data calculation control unit 21 rotates the plate cylinder 11 to bring the ejection head 22 closer to a position close to the plate cylinder 11 by the head separation / contact device (recording head separation / contact means) 31. The distance between the ejection head 22 and the surface of the plate material 9 on the plate cylinder 11 is controlled by mechanical distance control such as an abutment roller or by control of a head separation / contact device based on a signal from an optical distance detector during drawing. It is kept at a predetermined distance. As the ejection head 22, a single head, a multi-head, or a full line head can be used, and the main scanning is performed by rotating the plate cylinder 11. In the case of a multi-head having a plurality of discharge units or a full line head, the arrangement of the discharge units is set in the axial direction. Further, in the case of a single head or a multi-head, the head 22 is moved in the axial direction of the plate cylinder by one rotation of the plate cylinder 11 by the image data calculation control unit 21 so that the ejection position and the halftone dot obtained by the above calculation are obtained. The oil-based ink is discharged onto the plate material 9 mounted on the plate cylinder 11 at an area ratio.
As a result, a halftone image corresponding to the density of the print document is drawn on the plate material 9 with the oil-based ink. This operation continues until an oil-based ink image for one color of the printing original is formed on the plate material 9 and a printing plate is completed. On the other hand, when the ejection head 22 is a full line head having a length substantially equal to the width of the plate cylinder,
One rotation of the plate cylinder forms an oil-based ink image for one color of the printed document on the plate material 9 to complete a printing plate. By performing main scanning by rotating the plate cylinder in this manner, it is possible to increase the positional accuracy in the main scanning direction and perform high-speed drawing.

Next, in order to protect the ejection head 22,
The ejection head 22 is retracted away from a position close to the plate cylinder 11. At this time, the ejection head 22 and the head sub-scanning means 32 may be separated or contacted together, or the ejection head 22 and the ink supply unit 24 and all the head sub-scanning means 32 may be separated and attached together. You can also touch. In addition, the fixing device 5 and the dust removing device 10 are also provided with separating / contacting means together with the ejection head 22, the ink supply unit 24, and the head sub-scanning means 32 so that they can be retracted.

This separation / contact means operates so that the recording head is separated from the plate cylinder by at least 500 μm except during drawing. The detachment operation may be a sliding 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 manner, the head can be protected from physical damage or contamination, and a long life can be achieved.

The formed oil-based ink image is reinforced by heating or the like in the fixing device 5. As the fixing means of the ink, known means such as heat fixing, solvent fixing, and flash exposure fixing can be used. In the heat fixing, halogen lamp irradiation, hot air fixing using a heater, and heat roll fixing are generally used. In this case, in order to enhance the fixing property, the plate cylinder is heated, the plate material is heated in advance, drawing is performed while applying hot air, the plate cylinder is coated with a heat insulating material, and the plate cylinder is only fixed during fixing. It is effective to take measures such as separating the plate material from the plate material and heating only the plate material alone or in combination. In solvent fixing, spray a solvent that can dissolve the resin component in the ink such as methanol and ethyl acetate,
Excess solvent vapor is recovered. Also, flash fixing using a xenon lamp or the like is known as a fixing method of electrophotographic toner, and has an advantage that fixing can be performed in a short time. At least in the process from the formation of the oil-based ink image by the ejection head 22 to the fixing by the fixing device 5,
It is desirable that the dampening solution supply device 3, the printing ink supply device 4, and the blanket cylinder 12 are kept out of contact with the plate material 9 on the plate cylinder.

The printing process after the printing plate is formed 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 print image, and the print ink image is transferred onto the blanket cylinder 12 rotating together with the plate cylinder 11, Next, the printing paper P passing between the blanket cylinder 12 and the impression cylinder 13
By transferring the printing ink image on the blanket cylinder 12 thereon, printing for one color is performed. Plate 9 after printing
Is removed from the plate cylinder 11 by the automatic plate discharging device 8, the blanket on the blanket cylinder 12 is cleaned by the blanket cleaning device 14, and the next printing is possible.

Next, a detection device according to the present invention will be described. The detection device detects foreign matter on the head, dust detection,
The purpose is vibration detection. Regarding the detection of foreign matter adhesion to the head, an abnormal current, an image quality defect, and a meniscus shape abnormality are detected on the head, thereby stopping the drawing operation and / or activating a head cleaning unit described later. As an example of a method for detecting an abnormal current to the head, an image quality defect, and a meniscus shape abnormality, an example as shown in FIG. 11 can be given. That is, when dust adheres to the head, the discharge gap is short-circuited or shortened, and an abnormally large current flows than the normal head current. Therefore, in order to detect such an abnormal current to the head, a current i flowing through the head is detected by a current detection circuit 111, and an electric signal is converted into a digital signal by a signal processing circuit 112.
Send to 110. The CPU 110 compares the received digital signal with a reference value in the memory 113, and operates the drawing stop means 117 and / or the cleaning means 118 when the comparison result is out of the allowable range.

As a method of detecting a meniscus shape abnormality, there are:
For example, the shape of the meniscus M formed by the head 22 and the printing ink by the capillary phenomenon is provided in the vicinity of the head.
The image is shot by the CD camera 1141, the shot image is processed by the image processing circuit 115 and the CPU 110, and the shape of the meniscus M is automatically measured.
The CPU 110 compares the reference shape of the meniscus M in 3 with the CPU 110. If no dust adheres to the head 22, the CCD camera 1141 projects a meniscus shape.
If dust adheres to the CCD 2, the CCD camera 1141 captures a distorted shape. As a result of the comparison by the CPU 110, if the distorted shape is out of the allowable range, the CPU 110 causes the drawing stop means 117 and / or the cleaning means 118. To work.

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

As for dust detection, dust adhering to the plate material or dust flying in the machine is detected. As the detection means, various methods such as optical detection or weight detection of filtered dust are used, but an optical detection method is preferably used. FIG. 12 shows an example of a dust detection unit using this optical detection method. A plurality of pairs of light-emitting elements and light-receiving elements 1221-1231, 1222-123 are provided on a plate material for which dust is to be detected (A) or in a place where dust easily flies in the machine (B).
2 is arranged. The light emitting elements 1221 and 1222 are LEDs
Is connected to the LED driver 121, and this LE
The D driver 121 causes the light emitting elements 1221 and 1222 to emit light under the control of the CPU 120. On the other hand, the light receiving elements 1231 and 1232 are phototransistors, and are connected to the photoelectric conversion circuits 1241 and 1242, respectively. When the light receiving elements 1231 and 1232 receive light emitted from the light emitting elements 1221 and 1222, the optical signals are converted into electric signals by the photoelectric conversion circuits 1241 and 1242 and output to the signal processing circuit 125. This signal processing circuit 125 includes first and second light receiving elements 1231 and 1
232 is converted into a digital signal, and C
Send to PU120. The CPU 120 compares the received digital signal with a reference value in the memory 126, and operates the drawing stop means 127 and / or the cleaning means 128 when the comparison result is out of the allowable range.

The printing apparatus 1 has means 10 for removing dust present on the surface of the plate material before or / and during drawing on the plate material. As the dust removing means 10, besides a known non-contact method such as suction removal, blowing removal, and electrostatic removal, a contact method using a brush, a roller or the like can be used. Or a combination thereof. In this case, an air pump usually used for a paper feeding device can be used for this purpose. In addition, a paper dust generation prevention device 15 is installed near the impression cylinder 13 as dust generation prevention means, so that paper dust adhering to the plate material can be prevented. As the paper dust generation preventing device 15, a method such as humidity control, suction by air or electrostatic force, or the like can be used.
Regarding vibration detection, individual or / and relative vibration of the head and / or plate cylinder is detected, and drawing is stopped or / and stopped. At this time, only the drawing signal applied to the head is stopped or / and the movement of the plate cylinder / head is stopped.

Next, the ink jet recording apparatus 2 will be described in detail. As shown in FIG. 2, the drawing unit used in the lithographic printing apparatus includes an inkjet recording device 2,
An ink supply unit 24 is provided. The ink supply unit 24 further includes an ink tank 25, an ink supply device 26, and an ink density control unit 29. In the ink tank 25, a stirring unit 27, an ink temperature management unit (ink temperature control unit) 28
including. The ink may be circulated in the head, and in this case, the ink supply unit also has a recovery circulation function. The ink stirring means 27 suppresses precipitation and aggregation of the solid components of the ink.
Rotary wings, ultrasonic vibrators,
A circulating pump can be used and used from these or in combination. The ink temperature management means 28 is arranged such that a high-quality image can be stably formed without a change in the physical properties of the ink due to a change in the surrounding temperature and a change in the dot diameter. As the ink temperature management means, a heating element or a cooling element such as a heater or a Peltier element is arranged in an ink tank together with a stirring means so as to keep the temperature distribution in the tank constant, and controlled by a temperature sensor such as a thermostat. A publicly known method such as the above method can be used. The temperature of the ink in the ink tank is 15 ° C. or more and 6
0 ° C. or less is desirable, and more preferably 20 ° C. or more and 50 ° C.
It is as follows. Further, the stirring means for keeping the temperature distribution in the tank constant may be shared with the ink stirring means for suppressing the precipitation and aggregation of the solid components of the ink. Also,
The printing apparatus has an ink density control unit 29 for performing high-quality drawing. The ink concentration is measured by optical detection, physical property measurement such as conductivity measurement, clay measurement, or management based on the number of drawn images. When performing management by physical property measurement, an optical detector, a conductivity measuring instrument, and a clay measuring instrument are provided alone or in combination in the ink tank 25 or the ink flow path, and controlled by an output signal thereof. When the management is performed based on the number of drawn images, the supply of liquid from the replenishment concentrated ink tank or the diluted ink carrier tank (not shown) to the ink tank 25 is controlled based on the number of plate making and the frequency.

As described above, the image data calculation control unit 21 calculates the input image data, and controls the head separation / contact device 31,
Alternatively, in addition to moving the head by the head sub-scanning means 32, a timing pulse from the encoder 30 installed on the plate cylinder is fetched, and the head is driven according to the timing pulse. Thereby, the positional accuracy in the sub-scanning direction can be improved. In addition, the driving of the plate cylinder when performing drawing by the ink jet recording apparatus can enhance the positional accuracy in the sub-scanning direction by using a high-precision driving unit different from the driving unit during printing. It is desirable to drive only the plate cylinder by mechanically separating it from the blanket cylinder, impression cylinder and the like. Specifically, for example, there is a method in which the output from a high-precision motor is reduced by a high-precision gear or a steel belt to drive only the plate cylinder. When performing high-quality drawing, such means are used alone or in combination.

Next, the ejection head will be described with reference to FIGS. However, the contents of the present invention are not limited to the following examples.

FIGS. 3 and 4 show an example of a head provided in an ink jet recording apparatus. The head 22 includes an upper unit 221 and a lower unit 22 made of an insulating base material.
2 and a discharge slit 22a at the tip, and a discharge electrode 22b is provided in the slit.
Are arranged, and the ink 23 supplied from the ink supply device is provided.
Is filled in the slit. As the insulating base material, for example, plastic, glass, ceramics, etc. can be applied. In addition, the discharge electrode 22b is formed on the lower unit 222 made of an insulating base material by aluminum,
Conduct vacuum deposition, sputtering, or electroless plating of conductive materials such as nickel, chromium, gold, and platinum, apply a photoresist on top of this, expose the photoresist through a predetermined electrode pattern mask, and develop. And discharge electrode 2
After the photoresist pattern 2b is formed, it is formed by a known method such as a method of etching and forming the photoresist pattern, a method of mechanically removing the pattern, or a method of combining them.

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

The width of the discharge electrode 22b is preferably as narrow as possible in order to form a high quality image. Specific numerical values vary depending on conditions, etc.
It is used in the range of the tip width of 100 μm.

For example, the discharge electrode 22b having a tip of 20 μm width
The distance between the discharge electrode 22b and the plate cylinder 11 serving as a counter electrode is set to 1.0 mm, and a voltage of 3 KV is applied between the electrodes for 0.1 millisecond to form 40 μm dots on the plate material 9.
Can be formed on.

FIGS. 5 and 6 are a schematic sectional view and a schematic front view, respectively, showing the vicinity of the ink discharge portion of another example of the discharge head. In the figure, reference numeral 22 denotes a discharge head, and the discharge head 22 has a first insulating base material 33 having a gradually decreasing shape.
have. A second insulating base material 34 is provided on the first insulating base material 33 so as to be spaced apart and opposed to the first insulating base material 33, and a slope portion 35 is formed at the tip of the second insulating base material 34.
The first and second insulating base materials are, for example, plastic,
It is made of glass, ceramics or the like. A plurality of ejection electrodes 22b are provided on an upper surface 36 at an acute angle with the inclined surface 35 of the second insulating base material 34 as an electrostatic field forming means for forming an electrostatic field in the ejection section. The tips of the plurality of ejection electrodes 22b are extended to near the tips of the upper surface portion 36, and the tips are formed of the first insulating substrate 3
3 and forms a discharge portion. An ink inflow path 37 is formed between the first and second insulating bases 33 and 34 as a means for supplying the ink 23 to the ejection section. An ink recovery path 38 is formed. The discharge electrode 22b
Is formed on the second insulating base material 34 by using a conductive material such as aluminum, nickel, chromium, gold, and platinum by a known method as described above. Individual electrode 22b
Are electrically insulated from each other. The amount by which the tip of the discharge electrode 22b projects from the tip of the insulating substrate 33 is preferably 2 mm or less. The reason why the amount of protrusion is preferable in the above range is that if the amount of protrusion is too large, the ink meniscus does not reach the tip of the discharge portion, making it difficult to discharge or lowering the recording frequency. The space between the first and second insulating bases 33 and 34 is preferably in the range of 0.1 to 3 mm. The reason for limiting this space to the above range is that if the space is too narrow, it becomes difficult to supply ink and it becomes difficult to discharge, or the recording frequency is lowered, and if the space is too wide, the meniscus is not stable. This is because the ejection becomes unstable. The ejection electrode 22b is connected to the image data calculation control unit 21, and when recording is performed, a voltage is applied to the ejection electrode based on image information to eject ink on the ejection electrode, and the ejection electrode 22b is arranged to face the ejection unit. Is drawn on the plate material (not shown). The direction opposite to the ink droplet ejection direction of the ink inflow path 37 is connected to an ink feeding unit of an ink supply device (not shown). A backing 39 is provided on the surface of the second insulating substrate 34 opposite to the surface on which the ejection electrodes are formed, facing away from each other, and an ink recovery path 38 is provided between the two. The space of the ink recovery path 38 is desirably 0.1 mm or more. The reason that this space is limited to the above range is that if the space is too narrow, it becomes difficult to collect ink, and ink leakage may occur. The ink recovery path 38 is connected to an ink recovery means of an ink supply device (not shown). When a uniform ink flow on the ejection section is required, a groove 40 may be provided between the ejection section and the ink recovery path. FIG. 6 is a schematic front view showing the vicinity of the ink ejection portion of the ejection head. A plurality of grooves are formed on the slope of the second insulating base 34 from the vicinity of the boundary with the ejection electrode 22 b toward the ink recovery path 38. 40 are provided. A plurality of the grooves 40 are arranged in the arrangement direction of the ejection electrodes 22b, and guide the ink from the openings on the ejection electrode 22b side to the respective grooves 40 by capillary force, and discharge the guided ink to the ink recovery path 38. Having. Also, the groove 40
Sucks a certain amount of ink near the tip of the discharge electrode by capillary force according to the opening diameter. Therefore, it has a function of forming an ink flow having a constant liquid thickness near the tip of the discharge electrode. The shape of the groove 40 may be any range as long as the capillary force acts, and particularly preferably, the width is 10 to 200 μm.
The depth ranges from 10 to 300 μm. The necessary number of grooves 40 are provided so that a uniform ink flow can be formed over the entire surface of the head.

The width of the discharge electrode 22b is preferably as narrow as possible to form a high-quality image, for example, for printing. Specific numerical values vary depending on conditions and the like, but are usually used in a range of a tip width of 5 to 100 μm.

FIGS. 7 and 8 show another example of the discharge head used to carry out the present invention. FIG. 7 is a schematic view showing only a part of the head for explanation. As shown in FIG. 7, the recording head 22 has a head body 4 made of an insulating material such as plastic, ceramic, or glass.
1 and meniscus regulating plates 42 and 42 '. In the figure, 2
Reference numeral 2b denotes an ejection electrode for applying a voltage to form an electrostatic field in the ejection section. Further, the control plates 42 and 42 '
The head body will be described in detail with reference to FIG. The head body 41 is perpendicular to the edge of the head body,
A plurality of ink grooves 43 for circulating ink are provided. The shape of the ink groove 43 may be set in a range where the capillary force acts so that a uniform ink flow can be formed. A particularly desirable width is 10 to 200 μm and the depth is 1.
0 to 300 μm. The ejection electrode 22b is provided inside the ink groove 43. The ejection electrode 22b is formed on the head body 40 made of an insulating material by using a conductive material such as aluminum, nickel, chromium, gold, and platinum.
According to a known method similar to that of the above-described apparatus embodiment, the ink groove 43 may be arranged on the entire surface or may be formed only on a part thereof. The discharge electrodes are electrically isolated. Two adjacent ink grooves form one cell, and the leading ends of the partition wall 44 at the center thereof have ejection portions 45 and 45 ′.
Is provided. In the ejection portions 45 and 45 ', the partition walls are thinner than the other partition portions 44 and are sharpened. Such a head body is machined with an insulating material block,
It is formed by a known method such as etching or molding. The thickness of the partition wall at the discharge part is preferably 5
１００100 μm, and the radius of curvature of the sharpened tip is 5
It is desirable that the thickness be in the range of ５０50 μm. The tip of the discharge section may be slightly chamfered, such as 45 '. Although only two cells are shown in the drawing, the cells are separated by a partition wall 46, and the tip 47 is formed at a discharge portion 45,
It is chamfered so as to be retracted from 45 '. Ink is supplied to the head from an I direction through an ink groove by an ink feeding means of an ink supply device (not shown) to supply ink to a discharge unit. Further, surplus ink is collected in the O direction by an ink collecting means (not shown), and as a result, fresh ink is always supplied to the ejection unit. In this state, the ink is ejected from the ejection unit by applying a voltage to the ejection electrode according to image information to a plate cylinder (not shown) holding the plate material on the surface thereof, which is provided so as to face the ejection unit. An image is formed on the plate material.

Another embodiment of the ejection head will be described with reference to FIG. As shown in FIG.
2 has a pair of substantially rectangular plate-shaped support members 50 and 50 '. These support members 50, 50 'are made of a plate-like plastic, glass, ceramic or the like having a thickness of 1 to 10 mm having an insulating property, and one surface of each is parallel to each other according to the recording resolution. A plurality of elongated rectangular grooves 51, 51 '(not shown) are formed. Each groove 51, 51 ′ has a width of 10 to 200 μm and a depth of 10 to 30
The discharge electrode 22b is preferably formed in a range of 0 μm, and the whole or a part thereof is formed with the discharge electrode 22b. Thus, the plurality of grooves 51, 5 are provided on one surface of the support members 50, 50 '.
By forming 1 ', a plurality of rectangular partitions 52 are inevitably provided between the grooves 51. Each support member 5
0, 50 'are combined so that the surfaces on which the grooves 51, 51' are not formed face each other. That is, the ejection head 22
Has a plurality of grooves on its outer peripheral surface for flowing ink. Grooves 5 formed in each support member 50, 50 '
1, 51 'are connected in a one-to-one correspondence via a rectangular portion 54 of the discharge head 22, and the rectangular portion 54 to which each groove is connected is a predetermined distance (50
５００500 μm). That is, on both sides of each rectangular portion 54, each partition 52 of each support member 50, 50 '
Is provided so that the upper end 55 thereof protrudes from the rectangular portion 54. A guide protrusion 56 made of an insulating material as described above is provided so as to protrude from each rectangular portion 54 to form a discharge portion. When the ink is circulated through the ejection head 22 configured as described above, the ink is supplied to each rectangular portion 54 through each groove 51 formed on the outer peripheral surface of one support member 50, and the support member on the opposite side is supplied. Discharge is performed through each groove 51 'formed in 50'. In this case, the ejection head 22 is inclined at a predetermined angle to enable smooth ink distribution. That is, the ejection head 22 is inclined such that the ink supply side (support member 50) is located above and the ink discharge side (support member 50 ') is located below. As described above, when the ink is circulated through the ejection head 22, the ink passing through each rectangular portion 54 gets wet along each protrusion 56, and an ink meniscus is formed near the rectangular portion 54 and the protrusion 56. Then, in a state where independent ink meniscuses are formed in the respective rectangular portions 54, the ink electrodes 2 are provided to face the discharge section, and the discharge electrodes 2 are arranged on the surface of the plate cylinder (not shown) holding the plate material.
By applying a voltage to 2b based on the image information, the ink is ejected from the ejection unit and an image is formed on the plate material.
By providing a cover for covering the groove on the outer peripheral surface of each support member 50, 50 ', a pipe-shaped ink flow path is formed along the outer peripheral surface of each support member 50, 50'. May be used to force the ink to circulate. In this case, it is not necessary to tilt the ejection head 22.

The head 22 described above with reference to FIGS. 3 to 9 can include a maintenance device such as a head cleaning means as required. For example, when the hibernation state continues,
When a problem occurs in the image quality, the tip of the ejection head is wiped with a flexible brush, brush, cloth, or the like, circulating only the ink solvent, supplying only the ink solvent, or sucking the ejection portion while circulating, A good drawing state can be maintained by performing such means alone or in combination. In order to prevent the ink from sticking, it is also effective to cool the head and suppress evaporation of the ink solvent. If the dirt is further severe, the ink is forcibly sucked from the ejection part, the jet of air, ink, or ink solvent is forcibly injected from the ink flow path, or the head is immersed in the ink solvent, Applying a sound wave is also effective, and these methods can be used alone or in combination.

Next, an on-press drawing multicolor planographic printing press will be described as a specific example of the present invention.

FIG. 10 shows an example of the overall configuration of an on-press 4-color single-sided lithographic sheet-fed printing press. As shown in FIG.
The color single-sided printing apparatus basically has a structure including four plate cylinders 11, blanket cylinders 12, and impression cylinders 13 of the single-color single-sided printing apparatus shown in FIG. . Although not shown, a known transfer cylinder method or the like is used to transfer the printing paper indicated by K in the figure between adjacent impression cylinders. Although not described in detail, as can be easily imagined from the example of FIG.
2. It has a structure in which a plurality of impression cylinders 13 are provided so that printing is performed on the same surface of the printing paper P. When only one color plate is to be formed on the plate cylinder, only the number of printing colors is required. Plate cylinder,
Has a blanket cylinder. (Such a printing apparatus is called a unit-type printing apparatus.) On the other hand, a common impression cylinder type that shares one impression cylinder having a diameter that is an integral multiple of the plate cylinder diameter with respect to a plate cylinder and a blanket cylinder for a plurality of colors. When the present invention is implemented in a printing apparatus, a plate cylinder for the number of colors to be printed, a blanket cylinder may share one impression cylinder, or a plate cylinder for a plurality of colors, one impression cylinder for a blanket cylinder. A structure in which a plurality of shared structures are provided and the total number of plate cylinders and blanket cylinders is equal to the number of colors to be printed may be employed. In this case, the transfer of the printing paper between the adjacent common impression cylinders uses the known transfer cylinder method or the like. On the other hand, when a plate of a plurality of colors is formed on a plate cylinder, a plate cylinder and a blanket cylinder are required by a value obtained by dividing the number of colors to be printed by the number of plates on one plate cylinder. For example, when plate materials for two colors are prepared on a plate cylinder, four-color printing on one side can be performed by a printing machine 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,
The impression cylinder is provided with a means for holding the printing paper until the printing of the required color is completed, if necessary, and the printing paper is transferred between the impression cylinders using a known transfer cylinder method or the like. For example, in the case of a printing press having two plate cylinders and two blanket cylinders each of which creates a plate material for the two colors described above, two-color printing is performed when one of the impression cylinders holds the printing paper and makes two rotations, and then The printing paper is transferred between the impression cylinders, and when the other impression cylinder holds the printing paper and makes two rotations, two-color printing is further performed to complete four-color printing. Although the number of impression cylinders may be the same as the number of plate cylinders, one plate cylinder may be shared by several plate cylinders and blanket cylinders.

On the other hand, when the present invention is embodied as an on-press drawing multicolor double-sided lithographic printing machine, a known printing paper reversing means is provided between at least one adjacent impression cylinder of the unit-type printing apparatus. A structure in which a plurality of the above-described common impression cylinder type printing apparatuses are arranged and a known printing paper reversing means is provided between at least one adjacent impression cylinder, or the plate cylinder 11 and the blanket cylinder 12 of the single-color single-sided printing apparatus shown in FIG. Are provided so that printing is performed on both sides of the printing paper P. In the structure shown in FIG. 1, when only a plate for one color is formed on the plate cylinder, the plate cylinder and blanket cylinder are provided for the number of colors necessary for printing on both sides of the printing paper. On the other hand, when a plurality of color plates are formed on the plate cylinder as described above, the number of plate cylinders, blanket cylinders, and impression cylinders can be reduced.
In addition, when one plate cylinder is shared by several plate cylinders and blanket cylinders, the number of impression cylinders can be further reduced. The plate cylinder is provided with a means for holding printing paper until printing of a required color is completed, if necessary. The details are omitted because they can be easily analogized by the above-described example of the on-press drawing multicolor single-sided lithographic printing press.

As described above, the example of the sheet-fed printing apparatus has been described as the embodiment of the on-press drawing multicolor lithographic printing apparatus of the present invention. On the other hand, when the present invention is implemented as an on-press drawing multicolor WEB (rolled paper) lithographic printing apparatus, the above-described unit type and common impression cylinder type can be suitably used. Also, on-machine drawing multi-color WEB (winding paper)
When the present invention is implemented as a double-sided printing apparatus, both the unit type and the common impression cylinder type have a structure in which a known web reversing means is provided between at least one adjacent impression cylinder, and printing is performed on both sides of the printing paper P. Thus, it can be achieved by a structure having a plurality. In addition, the most preferable one as the on-press drawing multicolor WEB (winding paper) double-sided printing apparatus is BB (blanket printing).
To blanket) type. This is a one-color plate cylinder for printing one side of the web, a blanket cylinder (without an impression cylinder) and a one-color plate cylinder for printing the other side, a blanket cylinder (also without an impression cylinder). Have a structure in which the blanket cylinders are pressed against each other during printing for the number of colors, and multi-color double-sided printing is achieved by the WEB passing between the blankets pressed during printing.

Another example of an on-press lithographic printing apparatus is that a blanket cylinder has two plate cylinders, and when printing is performed, drawing is performed on the other plate cylinder. You can also. In this case, it is desirable that the drive of the plate cylinder performing drawing is mechanically independent of the blanket.
Thus, drawing can be performed without stopping the printing apparatus. As can be easily analogized, this can be applied to an on-press drawing multicolor single-sided lithographic printing apparatus and an on-press drawing multicolor double-sided lithographic printing apparatus.

Next, the plate material (printing plate) used in the present invention will be described.

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

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

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

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

Zinc oxide to be used in the present invention may be, for example, zinc oxide, zinc oxide, zinc oxide, and zinc oxide, as described in “Pigment Handbook” edited by Japan Pigment Technical Association, page 31, Shinbundo Co., Ltd. (1968). Any of those commercially available as wet zinc white or activated zinc white may be used.

That is, depending on the starting materials and the production method, zinc oxide may be a dry method called a French method (indirect method), an American method (direct method) or a wet method. For example, Shodo Chemical Co., Ltd. Chemical Co., Ltd., Hakusui Chemical Co., Ltd.,
Examples include those commercially available from Honjo Chemical Co., Ltd., Toho Zinc Co., Ltd., and Mitsui Kinzoku Kogyo Co., Ltd.

Specific examples of the resin used as the binder include vinyl chloride monovinyl acetate copolymer, styrene-butadiene copolymer, styrene-methacrylate copolymer, methacrylate copolymer, and acrylate copolymer. , Vinyl acetate copolymer, polyvinyl butyral, alkyd resin, epoxy resin, epoxy ester resin, polyester resin, polyurethane resin and the like. These resins may be used alone or in combination of two or more.

The content of the resin in the image receiving layer is preferably from 9/91 to 20/80 in terms of the weight ratio of resin / zinc oxide.

The desensitization of zinc oxide has been conventionally carried out as this type of desensitization treatment solution, a treatment solution containing a cyanide compound containing ferrocyanate or ferricyanate as a main component, an ammine cobalt complex, phytic acid and derivatives thereof. Also, a cyan-free treatment liquid containing a guanidine derivative as a main component, a treatment liquid containing an inorganic acid or an organic acid that forms a chelate with zinc ions as a main component, a treatment liquid containing a water-soluble polymer, and the like are known.

For example, as a cyanide-containing treatment liquid,
JP-B-44-9045, JP-B-46-39403, JP-A-52-76101, JP-A-57-107889, and JP-A-57-107889.
4-117201 and the like.

Hereinafter, the oil-based ink used in the present invention will be described.

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 an electric resistance of 10 ⁹ Ωcm or more and a dielectric constant of 3.5 or less. is there.

The non-aqueous solvent having an electric resistance of 10 ⁹ Ωcm or more and a dielectric constant of 3.5 or less used in the present invention is preferably a linear or branched aliphatic hydrocarbon, alicyclic hydrocarbon, or aromatic hydrocarbon. There are hydrogen, and halogenated forms of these hydrocarbons. 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 (Isoper; trade name of Exxon), Shellsol 70, shell Sol 71 (Shellsol; trade name of Shell Oil Co.), Amsco OMS, Amsco 460 solvent (Amsco; trade name of Spirits Co., Ltd.), silicone oil and the like are used alone or in combination. The upper limit of the electric resistance of such a non-aqueous solvent is about 10 ¹⁶ Ωcm, and the lower limit of the dielectric constant is about 1.9.

The reason why the electric resistance of the non-aqueous solvent used is in the above range is that if the electric resistance is low, the electric resistance of the ink will not be appropriate and the ejection of the ink by the electric field will be poor. The reason for setting the range is that when the dielectric constant is high, the electric field is easily relaxed in the ink, so that the ejection of the ink is likely to be deteriorated.

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

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

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

As such a resin (P), specifically,
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 copolymers), vinylidene chloride copolymers, vinyl alkanoate polymers and copolymers, allyl alkanoate polymers and copolymers, and polymers and copolymers 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 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,
Silicon resin, amide resin, hydroxyl and carboxyl group modified polyester resin, butyral resin, polyvinyl acetal resin, urethane resin, rosin resin, hydrogenated rosin resin, petroleum resin, hydrogenated petroleum resin, maleic acid resin, terpene resin, hydrogenated Terpene resin, coumarone-indene resin, cyclized rubber-methacrylic acid ester copolymer, cyclized rubber-acrylic acid ester copolymer, copolymer containing a nitrogen-free heterocycle (for example, furan Ring, tetrahydrofuran ring, thiophene ring, dioxane ring, dioxofuran ring, lactone ring,
Benzofuran ring, benzothiophene ring, 1,3-dioxetane ring, etc.), 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% by weight of the whole ink. If the content is low, it is difficult to obtain affinity between the ink and the image receiving layer of the printing original plate, and a good image cannot be obtained, or problems such as reduced printing durability tend to occur. When the content is large, there are problems such as difficulty in obtaining a uniform dispersion, difficulty in clogging of the ink in the discharge head, and difficulty in obtaining stable ink discharge.

The oil-based ink used in the present invention preferably contains a coloring material as a coloring component together with the above-described dispersed resin particles, for example, for plate inspection of a plate after plate making.

As the coloring material, any pigments and dyes conventionally used in oil-based ink compositions or liquid developers for electrophotography can be used.

As the pigments, those generally used in the technical field of printing can be used irrespective of inorganic pigments and organic pigments. Specifically, for example, carbon black, cadmium red, molybdenum red, chrome yellow, cadmium yellow, titanium yellow, chromium oxide, viridian, cobalt green, ultramarine blue, Prussian blue, cobalt blue, azo pigment, phthalocyanine pigment , Quinacridone-based pigments, isoindolinone-based pigments, dioxazine-based pigments, threne-based pigments, perylene-based pigments, perinone-based pigments, thioindigo-based pigments, quinophthalone-based pigments, metal complex pigments, and other known pigments. It can be used without.

As the dyes, azo dyes, metal complex dyes,
Naphthol dye, anthraquinone dye, indigo dye,
Oil-soluble dyes such as carbonium dyes, quinone imine dyes, xanthene dyes, aniline dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, naphthoquinone dyes, phthalocyanine dyes and metal phthalocyanine dyes are preferred.

These pigments and dyes may be used alone or in an appropriate combination, but may be contained in the range of 0.01 to 5% by weight based on the whole ink. desirable.

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

The resin particles dispersed in the non-aqueous solvent of the present invention, and further including the colored particles, preferably have an average particle size of 0.05 μm to 5 μm. It is more preferably 0.1 μm to 1.0 μm, and still more preferably 0.1 μm to 1.0 μm.
The range is from 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 the mechanical grinding method,
If necessary, a material as resin particles is mixed, melted and kneaded, and then directly pulverized by a conventionally known pulverizer to obtain fine particles, a dispersing polymer is used in combination, and a wet disperser (for example, a ball mill paint shaker) , Keddy mill, Dyno mill, etc.), a material to be a resin particle component,
A method of kneading a dispersion-assisting polymer (or a coating polymer) in advance to form a kneaded product, pulverizing the mixture, and then dispersing the mixture in the presence of a dispersing polymer may be used. Specifically, a method for producing a paint or a liquid developer for electrostatography can be used. For example, these methods are described in "Paint Flow and Pigment Dispersion" edited by Kenji Ueki, Kyoritsu Shuppan (1971), "Solomon , Paint Science, "Paint and Surface Coating Theo
ry and Practice ", Yuji Harasaki" Coating Engineering "Asakura Shoten (1971), Yuji Harasaki" Basic Science of Coatings "Maki Shoten (1977) and other books.

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

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

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

[0083]

Embedded image

In the general formula (I), X 1 is —COO
Represents-, -OCO- or -O-.

R represents an alkyl or alkenyl group having 10 to 32 carbon atoms, preferably an alkyl or alkenyl group having 10 to 22 carbon atoms, which may be linear or branched, and unsubstituted. Those are preferable, but may have a substituent.

Specifically, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, octadecyl, eicosanyl, docosanyl, decenyl,
A dodecenyl group, a tridecenyl group, a hexadecenyl group, an octadecenyl group, a linolenyl group and the like.

A1 and a2 may be the same or different from each other, and are preferably a hydrogen atom, a halogen atom (eg, a chlorine atom, a bromine atom, etc.), a cyano group, and a carbon number of 1 to 3.
(E.g., methyl, ethyl, propyl, etc.), -COO-Z1 or -CH2COO-Z1
[Z1 represents a hydrogen atom or an optionally substituted hydrocarbon group having 22 or less carbon atoms (eg, an alkyl group, an alkenyl group, an aralkyl group, an alicyclic group, an aryl group, etc.)].

Specifically, Z1 represents a hydrocarbon group in addition to a hydrogen atom, and a preferred hydrocarbon group has 1 carbon atom.
To 22 optionally substituted alkyl groups (e.g., methyl, ethyl, propyl, butyl, heptyl, hexyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl) Group,
Octadecyl, eicosanyl, docosanyl, 2-
Chloroethyl group, 2-bromoethyl group, 2-cyanoethyl group, 2-methoxycarbonylethyl group, 2-methoxyethyl group, 3-bromopropyl group, etc.), having 4 to 18 carbon atoms
Optionally substituted alkenyl groups (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., and an optionally substituted aralkyl group having 7 to 12 carbon atoms (e.g., benzyl) Group, phenethyl group, 3-
Phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group, chlorobenzyl group, bromobenzyl group, methylbenzyl group, ethylbenzyl group, methoxybenzyl group, dimethylbenzyl group, dimethoxybenzyl group, etc.),
An optionally substituted alicyclic group having 5 to 8 carbon atoms (eg, cyclohexyl group, 2-cyclohexylethyl group, 2-cyclopentylethyl group, etc.), and an optionally substituted aromatic group having 6 to 12 carbon atoms (For example, phenyl, naphthyl, tolyl, xylyl, propylphenyl, butylphenyl, octylphenyl, dodecylphenyl, methoxyphenyl, ethoxyphenyl, butoxyphenyl, decyloxyphenyl, chlorophenyl) , Dichlorophenyl, bromophenyl, cyanophenyl, acetylphenyl, methoxycarbonylphenyl, ethoxycarbonylphenyl, butoxycarbonylphenyl, acetamidophenyl, propioamidophenyl, dodecylylamidophenyl, etc.) Be mentioned

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

The proportion of the polymer component represented by the general formula (I) in the dispersion polymer is preferably at least 50% by weight, more preferably at least 60% by weight.

Specific examples of these dispersion polymers include:
Examples include the dispersion stabilizing resin (Q-1) used in Examples, and a commercially available product (Solprene 1205, manufactured by Asahi Chemical Industry Co., Ltd.) can also be used.

The dispersion polymer is preferably added in advance during the polymerization when producing the resin (P) particles as an emulsion (latex) or the like.

When the dispersing polymer is used, the amount of addition is about 0.05 to 4% by weight based on the whole ink.

The dispersed resin particles and the colored particles (or the coloring material particles) in the oil-based ink of the present invention are preferably positively or negatively charged electroconductive particles.

In order to impart an electric detecting property to these particles, it can be achieved by appropriately utilizing a technique of a wet type electrophotographic developer. Specifically, the above-mentioned “Recent development and practical use of electrophotographic development systems and toner materials”, pp. 139-148,
The Society of Electrophotography, "Basics and Application of Electrophotographic Technology," 497-
505 (Corona Co., 1988), Yuji Harasaki "Electrophotography" 16 (No. 2), page 44 (1977), and the like, using an electric test material and other additives.

Specifically, for example, British Patent No. 8934
No. 29, No. 934038, and No. 1122397
Nos. 3,900,412 and 4,606,989.
No., JP-A-60-179751, JP-A-60-18596
No. 3, JP-A-2-13965 and the like.

The charge control agent as described above is preferably used in an amount of 0.001 to 1.0 part by weight based on 1000 parts by weight of the dispersion medium as the carrier liquid. If desired, various additives may be added. The upper limit of the total amount of these additives is regulated by the electrical resistance of the oil-based ink. That is, if the electrical resistance of the ink from which the dispersed particles have been removed is lower than 10 9 Ωcm, it becomes difficult to obtain a high-quality continuous tone image. is necessary.

[0098]

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

Production Example 1 Production 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. Warmed. 0.8 g of 2,2'-azobis (isovaleronitrile) (abbreviated AIVN) was added as a polymerization initiator and reacted for 3 hours. Twenty minutes after addition of the initiator, cloudiness 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 the mixture was stirred for 2 hours to distill off unreacted vinyl acetate. After cooling, the mixture was passed through a 200-mesh nylon cloth, and the resulting white dispersion was a latex having a degree of polymerization of 90% and an average particle size of 0.23 μm and having good monodispersity. The particle size was measured with CAPA-500 (manufactured by Horiba, Ltd.).

[0100]

Embedded image

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

Example 1 First, an oil-based ink was prepared. <Oil-based ink (IK-1)> dodecyl methacrylate /
Acrylic acid copolymer (copolymerization ratio; 95/5 weight ratio)
0 g, Nigrosine 10 g and Shersol 71 30 g
Was placed in a paint shaker (manufactured by Toyo Seiki Co., Ltd.) together with the glass beads, and dispersed for 4 hours to obtain a fine dispersion of nigrosine.

60 g (as solid content) of resin particles (PL-1) produced in Production Example 1 for ink resin particles, 2.5 g of the above nigrosine dispersion, and FOC-1400 (manufactured by Nissan Chemical Co., Ltd., Tetradecyl Alcohol) (15 g) and 0.08 g of octadecene-half-maleic acid octadecylamide copolymer were diluted to 1 liter of Isopar G to prepare a black oil-based ink.

Next, an on-press drawing lithographic printing apparatus (FIGS. 1-2)
2) of the oil-based ink IK-12 prepared as described above was filled in an ink tank. Here, 900 dp shown in FIG.
i, a 64 channel multihead was used. A throwing heater and a stirring blade are provided in the ink tank as ink temperature management means, the ink temperature is set to 30 ° C., and the stirring blade is
The temperature was controlled with a thermostat while rotating at 0 rpm. Here, the stirring blade was also used as a stirring means for preventing sedimentation and aggregation. Also, the ink flow path is partially transparent,
An LED light-emitting element and a light-detecting element are arranged with the light-emitting element interposed therebetween, and an output signal from the LED light-emitting element and an ink diluent (Isoper G)
Alternatively, the concentration was controlled by feeding a concentrated ink (in which the solid concentration of the IK-1 ink was adjusted to twice).
As a plate material, a grained and anodized 0.1
An aluminum plate having a thickness of 2 mm was mounted on the plate cylinder with a mechanical device provided on the plate cylinder in addition to the plate bottom. Separate the dampening water supply device, printing ink supply device, and blanket cylinder so that they do not come into contact with the plate material, remove dust on the plate material surface by suction with an air pump, and then move the discharge head close to the plate material to the drawing position to print. The image data to be transmitted to the image data arithmetic control unit, and the 64-channel ejection head was moved while rotating the plate cylinder, thereby ejecting oily ink onto the aluminum plate to form an image. At this time, dust on the plate surface was optically detected, and an air pump suction was performed based on the output to remove dust from the plate material surface. Further, by detecting the meniscus shape at the tip of the head, foreign matter adhesion to the head was monitored, and an acceleration clock was attached to the head and the plate cylinder, and vibration was detected by relative vibration. The tip width of the ejection electrode of the inkjet head is 10
μm, and control was performed such that the distance between the head and the plate material was always 1 mm according to the output from the optical gap detection device. In addition, at the time of ejection, a bias voltage of 2.5
KV voltage is always applied, and 50%
A 0 V pulse voltage was further superimposed, and drawing was performed while changing the dot area by changing the pulse voltage in 256 steps in the range of 0.2 ms to 0.05 ms. No defective drawing due to dust was observed at all, and no image deterioration due to a change in dot diameter or the like was observed even when the outside air temperature changed or the number of plate making increased, and good plate making was possible.

Further, the image was strengthened by heating with a xenon flash fixing device (luminous intensity: 200 J / pulse, manufactured by Ushio Inc.) to produce a printing plate. In order to protect the ink jet head, the ink jet recording apparatus was retracted by 50 mm from a position close to the plate cylinder together with the sub-scanning means, and thereafter, printing was performed on printing paper by a normal lithographic printing method as described above. That is, a printing image is formed by applying a printing ink and a fountain solution, the printing 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 printing ink image on the blanket cylinder was transferred onto the paper.

The obtained printed matter was an extremely clear image without any skipping or blurring in the printed image even after passing through 10,000 sheets. 10 minutes after the end of plate making, Isopar G
After cleaning by dripping Isopar G from the head opening and storing the head in a cover filled with vapor of Isopar G, for 3 months
Good prints could be produced without the need for maintenance work.

Example 2 A circulating pump was used as a stirring means, and a 600 dpi full line ink jet head of the type shown in FIGS. 5, 7 and 9 was arranged. Here, a pump is used, and ink reservoirs are respectively provided between the pump and the ink inflow path of the discharge head, and between the ink recovery path of the discharge head and the ink tank. As a means, use a heater and the above-mentioned pump,
The ink temperature was set at 35 ° C. and controlled with a thermostat. Here, the circulation pump was also used as a stirring means for preventing precipitation and aggregation. In addition, a conductivity measuring device was arranged in the ink flow path, and the density was controlled by diluting the ink or feeding the concentrated ink based on the output signal. As a plate material, the above-mentioned aluminum plate was similarly mounted on a plate cylinder of a lithographic printing apparatus. After removing dust from the surface of the plate using a rotating brush made of nylon, the image data to be printed is transmitted to the image data arithmetic and control unit, and drawing is performed with a full line head while rotating the plate cylinder. An oil-based ink was ejected to form an image. At this time, dust on the plate surface was optically detected, and the output thereof was used to remove dust on the surface of the plate material using a rotating nylon brush. Also, by detecting the abnormal current of the head, foreign matter adhesion to the head is monitored, and an accelerometer is attached to the head and the plate cylinder. Vibration is detected based on the relative vibration. did. No drawing defects due to dust are seen at all,
Further, no image deterioration due to a change in the dot diameter or the like was observed at all even with a change in the outside air temperature or an increase in the number of plate making, and good plate making was possible. On the other hand, as a result of forcibly applying vibration to the device,
The application of voltage to the head was temporarily stopped, and the drawing was stopped. However, as soon as the vibration stopped, the drawing was resumed, and good plate making was performed. Subsequently, the image was solidified by heat roll fixing (power consumption: 1.2 kW, manufactured by Hitachi Metals, Ltd.) to form a printing plate. When printing was performed using the plate that had been made, the printed image was extremely clear without any jumping or blurring even after 10,000 sheets were passed. In addition, after the head was cleaned by circulating Isopar G to the head after the completion of plate making, cleaning was performed by bringing a nonwoven fabric containing Isopar G into contact with the tip of the head, and no maintenance work was required for three months. Good printed matter was produced.

Example 3 Next, a full-line head shown in FIG. 7 was used as an ejection head in an ink jet recording apparatus of a four-color one-side lithographic printing apparatus (see FIG. 10) for on-press drawing, and a Teflon-made contact roller was used. Gap adjustment (gap 0.8 mm) was performed. In addition, the same operation as in Example 1 was performed except that the concentrated ink was replenished to the ink tank by the number of drawn sheets as the ink density control means, and 5,000 plates were made. However, an optical detection device for dust in the machine was installed, and the air pump suction was performed on the surface of the plate material by the output. As a result, no defective drawing due to dust and no influence due to a change in outside temperature were observed. The dot diameter was slightly changed by the increase in the number of plate making, but it was within the range where there was no effect. In addition to the same flash fixing as described above, the plate made was irradiated with a halogen lamp (QIR manufactured by Ushio Inc., power consumption 1.
5 kW) and fixation by spraying with ethyl acetate. During irradiation with a halogen lamp, heating was performed at a plate surface temperature of 95 ° C. for 20 seconds. In the case of spraying with ethyl acetate, the spray amount was about 1 g / m 2. As a result, an extremely clear full-color printed matter was obtained without any skipping or blurring in the printed image even after the passing of 10,000 sheets. In particular, in the case of fixing by a heat roll or a halogen lamp, the fixing time could be greatly shortened by winding a heat insulating material (PET film) around the plate cylinder. In this case, the aluminum base was grounded by contact with a conductive brush (Sanderon, made by Tsuchiya, resistance: about 10-1 Ωcm).

Example 4 Example 1 was repeated, except that a paper plate material provided with a hydrophilic image receiving layer on the surface shown below was used instead of the aluminum plate of Example 1.
The same operation was performed.

A high-quality paper having a basis weight of 100 g / m 2 was used as a substrate, and a paper support provided with a water-resistant layer mainly composed of kaolin and resin components of polyvinyl alcohol, SBR latex and melamine resin on both surfaces of the substrate. An image receiving layer was provided so that the applied amount of the dispersion A prepared as described below with the following composition was 6 g / m 2 after drying to obtain a paper plate material.

Dispersion A Gelatin (Wako Pure Chemicals first grade) 3 g Colloidal silica (Nissan Chemical; Snowtex C, 20% aqueous solution) 20 g Silica gel (Fuji Silysia Chemical; Sylysia # 310) 7 g Hardener 0.4 g Distillation 100 g of water was dispersed with glass beads for 10 minutes using a paint shaker.

On the other hand, when high-quality paper was used as the printing paper, solid crushing failure occurred due to partial paper dust when printing 3,000 sheets. Printing was performed by operating an air suction pump disposed in the vicinity as a paper dust prevention device.
As a result, printing failure did not occur, and the obtained printed matter was an extremely clear image without flying or blurring even after passing 5,000 sheets. However, after 5,000 sheets were passed, an elongation of 0.1 mm was observed in the longitudinal direction of the A3 image.

Example 5 Instead of the aluminum plate of Example 1, a plate material provided with an image-receiving layer which can be made hydrophilic by a desensitizing treatment was used on the surface shown below, and the plate surface was rendered insensitive to oil after forming the plate. Non-image area is hydrophilized using a surface treatment device, the plate material conductive layer is grounded by contact with a conductive leaf spring (made of phosphor bronze) at the time of drawing, and fixing is performed by applying hot air to the plate material. Performed the same operation as in Example 1.

Using a high-quality paper having a basis weight of 100 g / m 2 as a substrate, a polyethylene film having a thickness of 20 μm was laminated on both sides of the substrate to form a water-resistant paper support. Apply the paint for one side, and after drying, make the coated amount 10 g / m2,
On top of this, the dispersion B was dried and applied as a coating amount of 15 g / m2.
An image receiving layer was provided so as to obtain a plate material of 2.

Paint for conductive layer; carbon black (30
% Aqueous solution) 5.4 parts, clay (50% aqueous solution) 54.6
Parts, SBR latex (solid content 50%, Tg 25 ° C) 3
Six parts and 4 parts of a melamine resin (solid content 80%, Sumiretz Resin SR-613) were mixed, and water was added so that the total solid content was 25% to obtain a paint. Dispersion B: 100 g of dry zinc oxide, 3 g of binder resin (B-1) having the following structure, 17 g of binder resin (B-2), 0.15 g of benzoic acid and 155 g of toluene were mixed with a wet disperser homogenizer (Japan). The dispersion was carried out at 6,000 rpm for 8 minutes using Seiki Co., Ltd.).

[0116]

Embedded image

The obtained printed matter was a very clear image with no skipping or blurring in the printed image even when 5,000 sheets were passed.

[0118]

According to the present invention, a large number of prints of clear images can be printed. In addition, a printing plate corresponding to digital image data can be stably produced with high image quality directly on a printing apparatus, and inexpensive and high-speed lithographic printing can be performed.

[Brief description of the drawings]

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

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

FIG. 3 is a schematic configuration diagram illustrating an example of another head provided in the ink jet recording apparatus used in the present invention.

FIG. 4 is a schematic cross-sectional view of the vicinity of an ink ejection unit in FIG. 3;

FIG. 5 is a schematic cross-sectional view of an example of another head provided in the ink jet recording apparatus used in the present invention, in the vicinity of an ink ejection section.

FIG. 6 is a schematic front view of the vicinity of an ink ejection unit in FIG. 5;

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

FIG. 8 is a schematic configuration diagram of a head obtained by removing a regulating 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 ink jet recording apparatus used in the present invention.

FIG. 10 is an overall configuration diagram schematically showing an on-press drawing four-color single-sided lithographic printing apparatus as an example of a multi-color machine according to the present invention.

FIG. 11 is a diagram illustrating an example of a method for detecting an abnormal current to a head, an image quality defect, and a meniscus shape abnormality.

FIG. 12 is a diagram illustrating an example of a dust detection unit using an optical detection method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 On-press lithographic printing apparatus 2 Ink jet recording apparatus 3 Dampening water supply apparatus 4 Printing ink supply apparatus 5 Fixing apparatus 6 Plate surface desensitization apparatus 7 Plate material automatic plate supply apparatus 8 Plate material automatic plate discharge apparatus 9 Plate material (printing plate) 10) Dust removing device 11 Plate cylinder 12 Blanket cylinder 13 Impression cylinder 14 Blanket cleaning device 14 'Impression cylinder cleaning device 15 Paper dust generation prevention device 21 Image data calculation control unit 22 Discharge head 221 Upper unit 222 Lower unit 22a Discharge slit 22b Discharge Electrode 23 Oil-based ink 24 Ink supply unit 25 Ink tank 26 Ink supply device 27 Stirring device 28 Ink temperature management unit 29 Ink density control unit 30 Encoder 31 Head separation / attachment device 32 Head sub-scanning unit 33 First insulating substrate 34 First 2nd insulating substrate 35 Slope view of 2nd insulating substrate 36 Top view of the second insulating base material 37 Ink flow path 38 Ink recovery path 39 Backing 40 Groove 41 Head body 42, 42 'Meniscus regulating plate 43 Ink groove 44 Partition wall 45, 45' Ejection section 46 Partition wall 47 Tip of partition wall 50, 50 'support member 51, 51' groove 52 partition wall 53 upper end portion 54 rectangular portion 55 upper end of partition wall 56 guide protrusion 111 current detection circuit 112 signal processing circuit 110 CPU 113 memory 117 drawing stop means 118 cleaning means 1141, 1142 CCD camera 1221, 1222 Light emitting element (LED) 1231, 1232 Light receiving element (phototransistor) 121 LED driver 120 CPU 1241, 1242 Photoelectric conversion circuit 125 Signal processing circuit 126 Memory 127 Drawing stop means 128 Cleaning means P Printing paper

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Sadao Osawa 4,000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture Inside Fujisha Shin Film Co., Ltd. Incorporated F term (reference) 2C056 EA20 EB07 EB29 EC07 EC28 EC38 FA02 FA10 FC01 JB01 KB40 2H084 AA25 AA38 AE05 AE07 CC05 2H113 AA02 AA03 BA05 BB07 BB22 BB32 BC02 CA00 FA54

Claims (19)

[Claims] 1. A printing plate in which a plate material is mounted on a plate cylinder of a printing press, and an image is formed directly on the plate material by an ink jet method in which an oil-based ink is discharged by utilizing an electrostatic field based on a signal of image data. In the on-press drawing lithographic printing method for producing and then performing lithographic printing using the plate material in that state, when an abnormality occurs, the image formation is directly stopped and / or the cause of the abnormality is removed. On-machine drawing lithographic printing method. Wherein said oil-based ink, the specific electrical resistance of 10 ⁹
2. The on-press lithographic printing method according to claim 1, wherein solid and hydrophobic resin particles are dispersed at least at room temperature in a non-aqueous solvent having a resistivity of not less than Ωcm and not more than 3.5. 3. An ink-jet drawing apparatus for discharging oil-based ink using an electrostatic field as a direct image forming means for forming an image directly on a plate material mounted on a plate cylinder of a printing press based on a signal of image data. An on-press drawing printing apparatus comprising: a lithographic printing means for performing lithographic printing with a printing plate formed by the direct image forming means;
Alternatively, an on-press lithographic printing apparatus comprising an abnormal cause removing means, wherein the image forming means is directly stopped at least temporarily and / or the abnormal cause removing means is activated at least temporarily by an output from the abnormality detecting means. 4. An on-press drawing lithographic printing apparatus according to claim 3, further comprising a recording head foreign matter adhesion detecting device for detecting foreign matter adhesion to a recording head of said ink jet drawing apparatus as said abnormality detecting means. . 5. The on-machine drawing according to claim 3, wherein the abnormality detecting means includes a dust detecting device for detecting dust in the on-press drawing lithographic printing apparatus and / or on the plate material. Lithographic printing equipment. 6. An on-press lithographic printing apparatus according to claim 3, wherein said abnormal detection means includes a on-press lithographic printing apparatus and / or a vibration detecting device for detecting vibration of the recording head. apparatus. 7. The oil-based ink has a specific electric resistance of 10 ⁹ Ω.
The on-press lithographic printing method according to any one of claims 3 to 6, wherein solid and hydrophobic resin particles are dispersed at least at room temperature in a non-aqueous solvent having a dielectric constant of 3.5 or more and a dielectric constant of 3.5 or less. 8. An on-press lithographic printing apparatus according to claim 3, wherein said direct image forming means comprises a fixing device for said ink. 9. A plate material surface dust removing means for removing dust existing on the plate material surface before and / or during drawing on the plate material, wherein the direct image forming means is provided. 3 ~
8. The on-press lithographic printing apparatus according to any one of 8 above. 10. The image forming apparatus according to claim 3, wherein at the time of drawing on said plate material, said direct image forming means performs main scanning by rotating a plate cylinder on which said plate material is mounted.
Item. 11. The ink-jet drawing apparatus includes a single head or a multi-head, and performs sub-scanning by moving the recording head in the axial direction of the plate cylinder when drawing on the plate material. An on-press lithographic printing apparatus according to claim 10. 12. The on-press lithographic printing apparatus according to claim 10, wherein said ink jet drawing apparatus includes a full line head having a length substantially equal to a width of the plate cylinder. 13. An on-press lithographic printing apparatus according to claim 3, wherein said ink jet drawing apparatus comprises an ink supply means for supplying ink to said recording head. 14. An on-press lithographic printing apparatus according to claim 13, further comprising ink recovery means for recovering ink from said recording head, and circulating ink by said ink supply means and ink recovery means. 15. An ink tank for storing said oil-based ink, wherein stirring means is provided in the ink tank.
An on-press lithographic printing apparatus according to any one of the preceding claims. 16. An on-press lithographic printing apparatus according to claim 3, further comprising an ink temperature control means for controlling the temperature of the ink in the ink tank storing the oil-based ink. . 17. An apparatus according to claim 3, further comprising an ink density control means for controlling an ink density of said ink.
6. The on-press lithographic printing apparatus according to any one of 6 to 6 above. 18. The ink jet drawing apparatus, when drawing on the plate material, causes the recording head to approach the plate cylinder,
4. A recording head separating / contacting means for separating said recording head from said plate cylinder except when drawing on said plate material.
18. The on-press lithographic printing apparatus according to any one of claims 17 to 17. 19. The on-press drawing lithographic apparatus according to claim 3, wherein said direct image forming means includes a print head cleaning means for cleaning said print head at least after the completion of plate making. Printing device.