JP2007185907A - Lithographic printing plate manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing plate manufacturing apparatus which is compact and has a rapid manufacturing speed. <P>SOLUTION: The printing plate manufacturing apparatus has an inkjet head 24 for forming an imaging part, an ink curing part for curing photo-curable ink of the imaging part, a gum solution coating part 30 which is arranged more upward than the ink curing part and coats an original printing plate P of a printing plate with a gum solution, a drying part 32 for drying it, a first conveying part for conveying the original printing plate P of the printing plate when the imaging part is formed and the ink is cured, a second conveying part for conveying the original printing plate P of the printing plate forwarded from the ink curing part to the gum solution coating part 30, and a third conveying part which is arranged upward of the first conveying part and conveys the original printing plate P of the printing plate when the gum solution is applied and dried. The second conveying part is a conveying passage changing-over and turning-over conveying part for changing the connection of the conveying passage and turning over the conveying direction of the original printing plate P of the printing plate in the second conveying passage. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plate making apparatus for producing a printing plate for planographic printing.

  In lithographic printing, a printing ink receptive area (hereinafter referred to as an image portion) and printing ink resilience corresponding to a plate original including a so-called image such as a gradation image or a line image such as a character on the surface of the printing plate. (Hereinafter referred to as a non-image area), and printing is performed by attaching printing ink to the ink receiving area. Usually, hydrophilic and oleophilic (ink-accepting) areas are formed in an image-like manner on the surface of the printing plate, and the hydrophilic areas are made ink repellent using dampening water.

  Conventionally, a manuscript original is temporarily output to a silver salt photographic film such as a lith film in an analog or digital manner, through which a diazo resin or a photopolymerizable photopolymer photosensitive material (printing original plate) is exposed and non-coated. The image was recorded (plate making) on the printing original plate by eluting and removing the image portion mainly using an alkaline solution.

  In recent years, many systems have been proposed for directly drawing digital image information of images such as gradation images and line images on a printing plate precursor because of demands for improvement of digital drawing technology and process efficiency. As an example of a system that directly draws such digital image information on a printing original plate, a system that records an image in a light mode or a thermal mode using a laser is known. However, in this plate making method, both the optical mode and the heat mode are generally performed after laser recording with an alkaline developer to dissolve and remove the non-image area, so that alkaline waste liquid is discharged. It is not preferable. Further, the method using a laser is expensive and large.

  In order to solve such a problem, Patent Document 1 discloses an inexpensive and compact image forming apparatus to which an ink jet method is applied, specifically, an aqueous emulsion of an organic polymer prepared by emulsion polymerization. Forming an oleophilic image on the surface by depositing a desired image on the surface of the conductive support, wherein the polymer is film-forming and adheres to the printing plate surface to form an oleophilic film. A method for manufacturing a lithographic printing plate is disclosed.

Special Table 2002-532306

  Thus, a printing plate can be produced by forming an image directly on a support by an ink jet method without dissolving and removing non-image areas. Further, the device can be miniaturized.

  Here, when making a printing plate, after recording an image on the printing plate precursor (support plate), a plate surface protection liquid, so-called gum solution, is applied to the surface of the printing plate precursor. By applying a gum solution to the surface of the printing plate precursor, not only the hydrophilicity of the non-image area is protected, but also image correction such as writing or erasing of the image area, and storage or reuse for a period until printing after plate making Can be protected from dirt caused by adhesion of fingerprints, oils and fats, dust, etc. during storage and attachment to a printing press and during handling, and can also prevent the occurrence of oxidation stains it can.

  However, after recording an image on the printing plate precursor, it is transported to a coating apparatus for applying a gum solution, and the gum solution is applied to the surface of the printing plate precursor. There is a problem that it takes time, that is, the plate making speed is slow.

  An object of the present invention is to solve the above-mentioned problems based on the prior art, to form an image portion on a printing plate precursor by an ink jet method, and to apply a gum solution to the surface of the printing plate precursor on which the image portion is formed Another object of the present invention is to provide a plate making apparatus having a high production speed.

  In order to solve the above problems, the present invention is a plate making apparatus for producing a printing plate for lithographic printing, which ejects ink droplets on a printing plate precursor according to a discharge signal to form an image portion; A fixing unit that is disposed adjacent to an inkjet head and fixes the image portion formed by the inkjet head to the printing plate precursor, and the printing that is disposed above the fixing unit and has the image portion formed thereon. A plate surface protective liquid application unit for applying a plate surface protective liquid to the plate original plate, a drying unit disposed adjacent to the plate surface protective liquid application unit, and drying the plate surface protective liquid applied in the plate surface protective liquid application unit; A first transport unit including a first transport path for transporting the printing plate precursor during recording of the image unit by the inkjet head and fixing of the image unit in the fixing unit. A printing plate precursor fed from the fixing unit, a second conveyance path having a second conveyance path for conveying the printing plate precursor to the plate surface protection liquid application unit, and disposed above the first conveyance unit, and the plate surface protection liquid application A third transport unit having a third transport path for transporting the printing plate precursor during application of the plate surface protective liquid in the unit and during drying of the plate surface protective liquid in the drying unit, and the second transport unit, At the same time switching the connection between the second conveyance path and the first conveyance path and the connection between the second conveyance path and the third conveyance path, the conveyance direction of the printing plate precursor in the second conveyance path The plate making apparatus is characterized in that it is a conveyance path switching reversal conveyance unit that also reverses the color.

  In addition, the second transport unit is connected to the third transport path of the plate surface protective liquid coating unit from a position where one end on the fixing unit side is connected to the first transport path of the fixing unit. A conveyor that is movable in the vertical direction with the other end as a center, and the conveyor constitutes the second transport path, and when the printing plate precursor is sent out from the fixing unit, And the other end after the printing plate precursor is fed from the first conveyance path of the fixing unit to the second conveyance path. Centering on the end portion, the one end portion is moved upward to a position where it is connected to the third transport path of the plate surface protective liquid application unit, and a part of the printing plate precursor is part of the plate surface protective liquid application unit. The printing plate precursor is carried into the third conveyance path and is conveyed by the third conveyance unit. After feeding is started, the end of the one is, it is preferable to start to move to the substantially horizontal position to be connected to the first conveying path of the fixing unit.

  According to the present invention, it is possible to produce a printing plate having a plate surface protection liquid applied on the surface thereof with a single apparatus, and further dispose the plate surface protection liquid application unit and the drying unit on the inkjet head and the fixing unit. Thus, the apparatus can be made compact.

  In addition, after a part of the printing plate precursor is carried into the plate surface protective liquid application unit, the end on the fixing unit side of the conveyance path switching and reversing unit is moved to a position connected to the conveyance path of the fixing unit. The next printing plate precursor can be sent out from the fixing unit to the conveyance path switching reversal unit before the plate surface protective liquid application unit is completely carried into the printing plate precursor. Thereby, the production speed of the printing plate can be increased, and the printing plate can be produced efficiently.

  Hereinafter, the plate making apparatus of the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings.

FIG. 1 is a schematic front view showing an embodiment of a plate making apparatus according to the present invention.
The plate making apparatus 10 shown in FIG. 1 includes a supply tray 20, a transport roller pair 21, an inkjet head 24, a fixing unit 26, a belt conveyor 28, a gum solution (plate surface protection liquid) application unit 30, and a drying unit 32. And a discharge tray 34.

  From the upstream side to the downstream side in the transport direction of the printing plate precursor P, the supply tray 20, the transport roller pair 21, the ink jet head 24, the fixing unit 26, the belt conveyor 28, the gum solution application unit 30, the drying unit 32, and the discharge tray 34 are arranged in this order. Has been placed. Here, the plate making apparatus 10 uses the belt conveyor 28 as a turning portion and the conveyance direction is reversed. That is, the transport path of the printing plate precursor P from the supply tray 20 to the belt conveyor 28 and the transport path of the printing plate precursor P from the belt conveyor 28 to the discharge tray are reversed. In addition, the gum solution application unit 30, the drying unit 32, and the discharge tray 34 are disposed vertically above the supply tray 20, the transport roller pair 21, the inkjet head 24, and the fixing unit 26.

The supply tray 20 is loaded with a printing plate precursor P made of an aluminum substrate or resin whose surface is hydrophilic. The printing plate precursor P arranged in the supply tray 20 is sent out from the supply tray 20 by the feed roller 38.
The conveyance roller pair 21 is disposed on the downstream side of the supply tray 20 in the conveyance direction of the printing plate precursor P. The conveying roller pair 21 is rotated in a predetermined direction (the arrow direction in FIG. 1) by a driving unit (not shown). The transport roller pair 21 sandwiches the printing plate precursor P transported from the supply tray 20 and transports it along the transport path.

The inkjet head 24 is disposed on the downstream side of the conveyance roller pair 21 in the conveyance direction of the printing plate precursor P.
The inkjet head 24 discharges hydrophobic ink droplets in accordance with the discharge signal, and forms an image portion on the printing plate precursor P that is transported by the transport roller pair 21. Here, the ejection signal is a signal for ejecting droplets so as to selectively apply hydrophobic ink droplets to a portion that becomes an image portion based on the image signal.
The inkjet head 24 is reciprocated in a direction (main scanning direction) orthogonal to the transport direction of the printing plate precursor P. The ink jet head 24 is moved in the main scanning direction, ink is ejected in accordance with the ejection signal, and the ink jet head 24 is moved to form an image portion in the main scanning direction. The pair 21 is intermittently conveyed in the sub-scanning direction. As described above, the ink jet head 24 is moved in the main scanning direction, the ink is ejected in accordance with the ejection signal, and the printing plate precursor is intermittently transported in the sub scanning direction by the transport roller pair 21, whereby the entire surface of the printing plate precursor P is printed. Make an image. Here, in this embodiment, UV ink is used as the ink. Here, the UV ink is an ink containing an ultraviolet curable resin that is cured by being irradiated with ultraviolet rays.

As the inkjet head 24, various types of inkjet heads such as a piezo type, a thermal jet type, and an electrostatic type can be used, and it is particularly preferable to use a piezo type inkjet head.
By adopting the inkjet head as a piezo method, the ink jet head can be selected as a piezo method, thereby expanding the selection range of ink liquid characteristics, that is, various inks can be used. Ink characteristics. Furthermore, it is possible to facilitate the ink droplet ejection control and the like.
Further, as a recording method, a continuous discharge method (continuous discharge method) that switches image recording on the printing plate precursor P by continuously discharging ink droplets and deflecting the discharged ink droplets according to the discharge signal. System), and a drop-on-demand system that switches between ejection / non-ejection of ink droplets according to ejection signals. Here, it is preferable to use the drop-on-demand method in view of simplicity of the apparatus, saving of ink, and suppression of ink evaporation.

The fixing unit 26 is disposed on the downstream side of the ink jet head 24 in the transport direction of the printing plate precursor P and includes a UV lamp 40. The printing plate precursor P on which the UV ink image portion is formed by the inkjet head 24 is transported by the transport roller pair 21 and passes through a position facing the fixing unit 26.
The UV lamp 40 irradiates the image portion formed on the printing plate precursor P with UV ink by the inkjet head 24, and cures the UV ink. Similarly to the inkjet head 24, the UV lamp 40 is also reciprocated in a direction (main scanning direction) orthogonal to the transport direction of the printing plate precursor P. Here, as described above, the printing plate precursor P is intermittently conveyed in one direction (sub-scanning direction) by the conveying roller pair 21 corresponding to the movement of the inkjet head 24 in the main scanning direction. Corresponding to intermittent conveyance of the printing plate precursor P in the sub-scanning direction, the UV lamp 40 is moved in the main scanning direction, and the printing plate precursor P is irradiated with ultraviolet rays, so that the entire image portion of the printing plate precursor P is displayed. Harden.
As the UV lamp 40, various lamps (light sources) such as an ultrahigh pressure mercury lamp, a UVLED, a metal halide lamp, and an ultraviolet fluorescent tube can be used. Note that these light sources may emit light including visible light rays. In particular, when the UV ink has sensitivity in the visible light region, the sensitivity can be further increased by irradiating light including visible light, and the UV ink can be suitably cured.

  Here, in the above-described embodiment, the UV lamp is moved in the main scanning direction to irradiate the entire surface of the printing plate precursor with UV light. However, the line shape is such that the UV lamp is arranged in the entire region orthogonal to the transport direction of the printing plate precursor. It is good. Thereby, it is possible to irradiate the entire surface of the printing plate precursor with UV light without moving the UV lamp.

  Further, a conveyance guide 36 for guiding the printing plate precursor P is provided at a portion facing the ink jet head 24 and the fixing unit 26. By providing the conveyance guide 36, the printing plate precursor P can be stably conveyed horizontally.

It is preferable that a through hole is formed at a position facing the inkjet head 24 of the conveyance guide 36 and the printing plate precursor P is sucked toward the conveyance guide 36 when the image portion is formed by the inkjet head 24.
When the image portion is formed by the inkjet head 24, the printing plate precursor P is sucked toward the conveyance guide 36, whereby the printing plate precursor P is fixed in a direction perpendicular to the conveyance guide 36, and the inkjet head 24 and the printing at the image forming position are printed. The distance from the original plate P is constant. Thereby, the drawing accuracy of image formation by the inkjet head 24 can be increased.
The method of making the distance between the inkjet head and the printing plate precursor constant is not limited to sucking the printing plate precursor toward the conveyance guide side, and the printing plate precursor is electrostatically adsorbed to the conveyance guide, and the printing plate The distance between the original plate and the conveyance guide may be constant.
The conveyance roller pair 21 and the conveyance guide 36 are conveyance units having a common conveyance path for the inkjet head 24 and the fixing unit 26, and constitute the first conveyance unit of the present invention.

The belt conveyor 28 is disposed on the downstream side of the fixing unit 26 in the conveyance direction of the printing plate precursor P, and includes a belt 42, belt rollers 44 and 46, and a vertical conveyance mechanism 48.
The belt 42 is a ring-shaped endless belt and is stretched by belt rollers 44 and 46. A driving source (not shown) is connected to the belt roller 46 and is rotated at a predetermined speed. The belt 42 is rotated by the rotation of the belt roller 46. Here, the drive source can rotate the belt roller 46 in both directions. Thereby, the belt 42 can also be moved in two directions indicated by arrows.

The vertical conveyance mechanism 48 is provided on the belt roller 44 on the fixing unit 26 and the gum solution application unit 30 side, and the gum roller application unit 48 is disposed from a position substantially horizontal to the conveyance path of the printing plate precursor P in the fixing unit 26. From the position where the printing plate precursor P can be sent out to the position where the printing plate precursor P can be sent out to the conveyance path of the printing plate precursor P in 30 or from the position where the printing plate precursor P can be sent out to the conveyance path of the printing plate precursor P in the gum solution application unit 30 The fixing unit 26 is moved up and down to a position substantially horizontal to the transport path of the printing plate precursor P.
As a mechanism for moving the belt roller 44, various methods can be used. For example, there is a mechanism for providing a guide rail at the end of the belt roller 44 and moving the belt roller along the guide rail.

  The belt conveyor 28 having such a mechanism rotates and moves the belt 42 to convey the printing plate precursor P fed from the fixing unit 26 onto the belt 42, and then causes the belt roll 44 to be moved by the vertical conveying mechanism 48. The belt 42 is rotated about the rotation axis of the belt roller 46, and the belt roller 44 is moved to a position where the printing plate precursor P can be sent out to the conveying path of the gum solution application unit 30. That is, the transport path of the printing plate precursor P is switched and the transport direction is reversed. Thereafter, the belt 42 is rotated to send the printing plate precursor P to the gum solution application unit 30. The movement of the belt conveyor will be described in detail later together with a method for preparing a printing plate.

The gum solution application unit 30 is disposed above the fixing unit 26 in the vertical direction, and includes a pair of application rollers 52 and a gum solution tank 54.
The application roller pair 52 is a pair of rubber rollers composed of an immersion roller 52a and an application roll 52b. The application roller pair 52 sandwiches the printing plate precursor P conveyed from the belt conveyor 28 and conveys it in a predetermined direction.
The gum solution tank 54 stores a gum solution (plate surface protection solution), and the immersion roller 52a is immersed therein.

  Examples of the gum solution include rinsing water, a gum arabic and the like, which are described in JP-A Nos. 54-8002, 55-1115045, 59-58431, and the like. A desensitizing liquid containing a starch derivative or the like can be used.

2A to 2C are schematic front views illustrating an example of a process of applying the gum solution to the printing plate precursor P by the gum solution application unit 30. FIG.
By rotating the application roller pair 52, the immersion roller 52a and the application roller 52b immersed in the gum solution tank 54 are rotated, and as shown in FIG. 2A, the gum solution is also applied to the surface of the application roller 52b. As a result, the gum liquid pool is formed in the nip portion of the application roller pair 52.

  When the printing plate precursor P is sandwiched between the nip portions of the coating roll pair 52, first, as shown in FIG. 2 (B), the printing plate precursor P fed to the belt conveyor 28 has an arbitrary tip of the immersion roller 52a. Touch position. Thereafter, the printing plate precursor P is further fed to the application roller pair 52 side by the belt conveyor 28, and is moved to the nip portion along the lower roller. As a result, a part of the gum solution pool is held between the printing plate precursor P and the coating roll 52b.

The printing plate precursor P is sandwiched and conveyed by the application roller pair 52 while the gum solution pool is held on the surface of the printing plate precursor P, so that the printing plate passed through the application roller pair 52 as shown in FIG. A gum solution having a certain thickness is applied to the surface of the original P by roller nip pressure.
In this way, the printing plate precursor P conveyed from the belt conveyor 28 is nipped and conveyed by the application roller pair 52, and the gum solution serving as a plate surface protective film is applied to the entire surface on the side where the image portion is formed.

  The drying unit 32 includes a fan 56, a heater 57, a discharge roller pair 58, a conveyance guide 60, and a cover 61.

The fan 56 is disposed to face the transport path of the printing plate precursor P. Air is blown to the surface of the printing plate precursor P coated with the gum solution.
The heater 57 is disposed between the transport path of the printing plate precursor P and the fan 56. Here, as the heater 57, various heat sources such as a halogen lamp, a nichrome wire heater, and a ceramic heater can be used, and it is particularly preferable to use a far infrared ceramic heater.
The discharge roller pair 58 is disposed on the downstream side of the heater 57 in the transport direction of the printing plate precursor P. The discharge roller pair 58 sandwiches and conveys the printing plate precursor P that has passed the position where the heater 57 is opposed.
The conveyance guide 60 is disposed on the downstream side of the application roller pair 52 in the conveyance path of the printing plate precursor P. The printing plate precursor P discharged from the application roller pair 52 passes through a position facing the fan 56 and the heater 57 and is guided so as to be sandwiched between the discharge roller pair 58.
The cover 61 is disposed so as to cover the fan 56, the heater 57, and the discharge roller pair 58.

The drying unit 32 heats the printing plate precursor P with the heater 57, and further blows air on the surface of the printing plate precursor P coated with the gum solution by the fan 56. As a result, the gum solution applied to the printing plate precursor P is dried and the solvent component of the gum solution is evaporated, whereby a plate surface protective film is formed on the printing plate precursor P.
Further, by blowing the air heated by the heater 57 as warm air on the printing plate stool P by the fan 56, the air blowing on the printing plate precursor P becomes warm air, and the gum solution can be dried more efficiently. it can.
In addition, by maintaining the atmosphere in the drying unit 32 by the cover 61 and the conveyance guide 60, it is possible to prevent the heat generated from the heater 57 from being dissipated and to efficiently dry the gum solution.

  The application roll pair 52, the conveyance guide 60, and the conveyance roller pair 58 are also conveyance units that constitute the conveyance path of the printing plate precursor P in the gum solution application unit 30 and the drying unit 32, and the third conveyance unit of the present invention. Constitute.

  The discharge tray 34 is disposed on the downstream side of the drying unit 32 in the transport direction of the printing plate precursor P. The discharge plate 34 receives the printing plate discharged from the drying unit 32.

  Next, the plate making apparatus of the present invention will be described in more detail by explaining a method for producing a printing plate in the plate making apparatus 10.

The printing plate precursor P delivered from the supply tray 20 is transported at a predetermined speed by a pair of transport rollers 21, passes through a position facing the ink jet head 24, and UV ink is ejected imagewise to form an image portion. .
The printing plate precursor P on which the image portion is formed is further conveyed, passes through a position facing the fixing portion 26, and the UV ink of the formed image portion is cured to fix the image.
The printing plate precursor P on which the image portion is fixed is conveyed to the belt conveyor 28.
The belt conveyor 28 sends the conveyed printing plate precursor P to a gum solution application unit 30 disposed above the fixing unit 26. The method for conveying the printing plate precursor P by the belt conveyor 28 will be described in detail later.

The printing plate precursor P sent from the belt conveyor 28 is nipped and conveyed by the application roller pair 52 of the gum solution application unit 30, and the gum solution is applied to the surface of the printing plate precursor P on which the image portion is formed.
The printing plate precursor P to which the gum solution is applied is conveyed to the drying unit 32, and after the applied gum solution is dried, it is discharged to the discharge tray 34 as a finished planographic printing plate.
In this way, the plate making apparatus 10 produces a printing plate on which an image portion is formed and a plate surface protective film is formed.

Next, a method for conveying the printing plate precursor P by the belt conveyor 28 will be described in detail.
FIGS. 3A to 3F are schematic front views showing an example of the transporting process of the printing plate precursor P by the belt conveyor 28. 3A to 3F, illustration of a part of the drying unit 32, the vertical movement mechanism 48, and the like is omitted in order to make the transport path of the printing plate precursor P easy to see.
First, when the printing plate precursor P is sent out by the transport roller pair 21 from the transport path of the printing plate precursor P in the fixing unit 26 (when the ink is cured), printing in the fixing unit 26 is performed as shown in FIG. In the present embodiment, the belt roller 44 is fixed at the same height (substantially horizontal) as the conveyance guide 36. Thereby, the surface of the belt 42 and the surface of the conveyance guide 36 are arranged on substantially the same plane.
Further, the belt rolls 44 and 46 rotate and move the belt 42 in the conveying direction of the printing plate precursor P (the arrow direction in FIG. 3, clockwise). Thereby, the printing plate precursor P sent by the transport roll pair 21 is transported in the direction of the arrow in FIG.

  Thereafter, the belt 42 is further moved, and as shown in FIG. 3B, the printing plate precursor P fed from the fixing unit 26 is conveyed onto the belt 42, and then the rotational movement of the belt 42 is stopped.

Next, as shown in FIG. 3C, the belt roller 44 is moved to a position connected to the conveyance path of the printing plate precursor P in the gum solution application unit 30 by the vertical conveyance mechanism 48. That is, the conveying path of the printing plate precursor P in the belt 42 connected to the conveying path of the printing plate precursor P in the fixing unit 26 (the conveying path of the printing plate precursor P in the belt conveyor 28) is changed to the gum solution applying unit 30 (of the Switch to the connection with the transport path of the printing plate precursor P at the time of applying the gum solution. That is, the conveyance path of the printing plate precursor P in the belt 42 and the conveyance path of the printing plate precursor P in the gum solution application unit 30 are connected.
As a result, the belt 42 is rotationally moved with the belt roll 46 as the center of the rotation shaft, and the belt roller 44 side becomes an inclined surface inclined at a predetermined angle. Here, the belt roller 44 is preferably moved to a height at which the transported printing plate precursor P contacts the lower roller of the application roller pair 52. As a result, as described above, the gum solution pool is formed on the upper roller of the application roller pair 52, and the gum solution can be applied to the upper surface of the printing plate precursor P.

  After the belt roller 44 is moved upward, as shown in FIG. 3D, the belt 42 is moved in the direction opposite to that when the printing plate precursor P is received from the fixing unit 26, that is, in the illustrated example, the belt 42 is counterclockwise. The printing plate precursor P is sent to the application roller pair 52 of the gum solution application unit 30 by rotating around (in the direction of the arrow in FIG. 3D).

  Next, the printing plate precursor P is conveyed by rotating the belt 42, and when the leading end of the printing plate precursor P is sandwiched between the application roller pair 52 as shown in FIG. The roller 44 is moved downward. Here, even when the belt 42 is moved downward and the belt 42 and the printing plate precursor P are separated from each other, the printing plate precursor P is nipped and conveyed by the application roller pair 52.

Thereafter, the belt roller 44 is moved to the same height as the conveyance guide 36 by the vertical movement mechanism 48, that is, the conveyance path of the printing plate precursor P in the belt conveyor 28 is connected to the conveyance path of the printing plate precursor P in the fixing unit 26. Then, as shown in FIG. 3 (F), an image portion is formed by the inkjet head 24, and a new printing plate precursor P ′ having the image portion fixed by the fixing portion 26 is sent out from the fixing portion 26.
In this way, the belt conveyor 28 switches the conveyance path of the printing plate precursor P from the fixing unit 26 to the gum solution application unit 30 and reverses the conveyance direction of the printing plate precursor P.
Further, as described above, the printing plate precursor P sandwiched between the application roller pair 52 is sandwiched and conveyed by the application roller pair 52, the gum solution is applied to the entire surface thereof, and then conveyed to the drying unit 32.

As described above, according to the present invention, an ink jet head, a fixing unit, a gum solution application unit, and a drying unit are integrally provided, whereby an image unit is formed, and a printing plate whose surface is protected by the gum solution is efficiently produced. Can be made well.
In addition, the apparatus can be miniaturized by providing a gum solution application unit and a drying unit on the inkjet head and the fixing unit. Further, the supply tray and the discharge tray for the printing plate precursor can be provided on the same surface.

  Further, the gum solution application unit 30 is disposed on the ink curing unit 26, and after a part of the printing plate precursor P is conveyed to the gum solution application unit 30, the entire printing plate precursor P is the gum solution application unit 30. The belt conveyor 28 is moved to the ink curing unit 26 side, that is, the conveyance path of the printing plate precursor P in the belt conveyor 28 and the conveyance path of the printing plate precursor P in the ink curing unit 26 are connected, By transporting the next printing plate precursor P sent out from the ink curing unit 26 to the belt conveyor 28, the production speed of the printing plate can be further increased.

Here, in this embodiment, a belt conveyor is used as a transport mechanism for transporting the printing plate precursor from the fixing unit to the gum solution application unit, and only one of the belt rollers is moved up and down. However, the present invention is limited to this. For example, both belt rollers may be moved up and down at the same time to move the belt conveyor in parallel. Moreover, as a conveyance mechanism, it is not limited to a belt conveyor, The roll conveyor etc. which comprise a some rotating roll side by side can be used.
Moreover, when using a belt conveyor for the conveyance mechanism which conveys a printing plate precursor to an inkjet head, it is preferable to form a through hole in the belt and convey the printing plate precursor from the through hole. By adsorbing the printing plate precursor to the belt, the printing plate precursor can be fixed on the belt, and the distance between the printing plate precursor and the inkjet head when forming the image part can be made constant. In the case of using a belt conveyor, the printing plate precursor and the belt can be moved together while the printing plate precursor is always attracted to the belt.

  In the present embodiment, UV ink is used as the ink, but the present invention is not limited to this, and various photocurable inks that can use visible light as curing light can also be used. Similarly, various active light sources that emit visible light or the like as active light can be used as the light source. Here, in the present invention, the active light is light having a wavelength for curing the photocurable ink. The active light source is a light source that emits at least active light.

Also, the ink is not limited to the photocurable ink of the present embodiment, and an ink in which at least resin particles are dispersed in a dispersion medium as an image component, and an ink in which a resin serving as an image component is dissolved in a solvent can also be used. .
When using an ink in which at least resin particles are dispersed in a dispersion medium as an image component, the ink that forms the image portion is heated as a fixing portion by a heater or the like, the resin particles are softened and flowed, and the image portion is printed on the printing plate precursor. For example, a non-contact type heating mechanism for fixing the printing plate, a contact type heating mechanism for holding and conveying the printing plate precursor by a pair of rollers, at least one of which is a heating roller, and fixing by heating and pressure can be used.

When using an ink in which a resin is dissolved in a solvent, a heating mechanism such as a heater or a mechanism that blows warm air on the printing plate precursor can be used as the fixing unit. Using these mechanisms, the image component can be fixed to the printing plate precursor by evaporating the solvent component.
The fixing unit is preferably a non-contact type fixing mechanism that fixes the ink without contacting the printing plate precursor. Thereby, it is possible to prevent the image portion from being displaced due to rubbing at the time of fixing.

  In the present embodiment, the image plate is formed by moving the inkjet head in the main scanning direction while intermittently conveying the printing plate precursor in the sub-scanning direction by the pair of conveying rollers. However, the present invention is not limited to this. The image plate may be formed on the entire surface of the printing plate precursor by moving the inkjet head in the main scanning direction while continuously conveying the printing plate precursor in the sub-scanning direction. In this case, the inkjet head includes a plurality of ejection units in the sub-scanning direction, and the sub-scan transport distance of the printing plate precursor during the scanning of the inkjet head once in the main scanning direction is set in the sub-scanning direction of the inkjet head. By setting it to the width or less, the image portion can be formed on the entire surface of the printing plate precursor only by transporting the printing plate precursor once in the sub-scanning direction.

Further, in the present embodiment, while the printing plate precursor P is conveyed in the sub-scanning direction, the inkjet head is moved in the main scanning direction to form the image portion on the entire surface of the printing plate precursor. However, the present invention is not limited to this. Alternatively, the printing plate precursor may be fixed, the inkjet head may be moved two-dimensionally in the main scanning and sub-scanning directions, and the image portion may be formed on the entire surface of the printing plate precursor.
In addition, as the ink jet head, a so-called full line head in which ink discharge portions are arranged in the entire region in the direction orthogonal to the transport direction of the printing plate precursor can be used.

  In this embodiment, as a method of transporting the printing plate precursor at a position facing the ink jet head, the fixing unit, and the drying unit, a method of transporting along a transport guide using a transport roller is used. Without limitation, the printing plate precursor may be conveyed using a belt mechanism.

Further, the gum solution application unit is not limited to the method of sandwiching and conveying the printing plate precursor by the application roller pair of the present embodiment, the method of applying the gum solution to the printing plate precursor by spraying, the gum on the printing plate precursor by the inkjet head. A method of applying a liquid can also be used. Here, also in the case of using the above method, it is preferable to provide a pair of conveying rollers for nipping and conveying the printing plate precursor sent out from the belt conveyor. By providing the pair of transport rollers, the printing plate precursor sent out from the belt conveyor can be transported as in the above embodiment. Thus, after the printing plate precursor is sandwiched between the conveying roller pair, the belt conveyor can be moved, and the next printing plate precursor sent out from the fixing unit can be conveyed onto the belt, and the plate making speed can be increased. .
Moreover, when using an inkjet head as a gum liquid application part, it is preferable to apply | coat a gum liquid selectively only to the non-image part of a printing plate precursor. Thus, by selectively applying the gum solution, the amount of the gum solution used can be reduced, and the plate surface protective film can be formed efficiently. As the ink jet head for applying the gum solution, ink jet heads having various methods and configurations similar to those of the ink jet head for forming the image portion described above can be used.

  Next, an example of a gum solution suitably used for the plate making apparatus of the present invention will be specifically described.

  As the gum solution, a desensitizing solution used for desensitizing a lithographic printing plate having an aluminum plate as a support can be used effectively. Preferable desensitizing liquid includes an aqueous solution containing at least one of a hydrophilic organic polymer compound, hexametaphosphoric acid and a salt thereof, phytic acid and a salt thereof.

  Specific hydrophilic organic polymer compounds include gum arabic, dextrin, alginates such as sodium alginate, water soluble cellulose such as carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide. , Water-soluble copolymers containing acrylamide units, polyacrylic acid, copolymers containing acrylic acid units, polyacrylic acid, copolymers containing acrylic acid units, polymethacrylic acid, copolymers containing methacrylic acid units, Examples thereof include a copolymer of vinyl methyl ether and maleic anhydride, a copolymer of vinyl acetate and maleic anhydride, and phosphoric acid-modified starch. Among them, gum arabic is preferable because of its strong desensitizing action. These hydrophilic polymer compounds can be used in combination of two or more as required, and are used at a concentration of about 1 to 40% by weight, more preferably 3 to 30% by weight.

  Specific examples of the hexametaphosphate include alkali metal hexametaphosphate and ammonium salt. Examples of the alkali metal salt or ammonium salt of hexametaphosphate include sodium hexametaphosphate, potassium hexametaphosphate, ammonium hexametaphosphate and the like. Specific examples of phytic acid or salts thereof include alkali metal salts such as sodium salt, potassium salt and lithium salt, ammonium salt and amine salt. Examples of amine salts include diethylamine, triethylamine, n-propylamine, di-n-propylamine, tri-n-propylamine, n-butylamine, n-amylamine, n-hexylamine, laurylamine, ethylenediamine, trimethylenediamine, Mention may be made of salts of tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, ethanolamine, diethanolamine, triethanolamine, allylamine, aniline and the like. The phytate may be a normal salt in which all 12 hydrogens of the acid are replaced, a hydrogen salt in which a part of the hydrogen of the acid is replaced (acidic salt), or a simple salt composed of a single base salt, 2 Any form of a double salt containing at least one kind of base as a component can be used. These compounds can be used alone or in combination of two or more.

  The desensitizing liquid used in the present invention preferably further contains a metal salt of a strong acid, whereby the desensitizing action can be enhanced. Specific metal salts of strong acids include sodium salt of potassium, potassium salt, magnesium salt, calcium salt and zinc salt, sodium salt of sulfuric acid, potassium salt, magnesium salt, calcium salt and zinc salt, sodium salt of chromic acid, Examples thereof include potassium salts, magnesium salts, calcium salts and zinc salts, and sodium fluoride and potassium fluoride. These metal salts of strong acids can be used in combination of two or more, and the amount is preferably about 0.01 to 5% by weight based on the total weight of the desensitizing solution. The desensitizing liquid used in the present invention has a pH value adjusted to an acidic range, more preferably 1 to 5, and most preferably 1.5 to 4.5. Therefore, when the pH of the aqueous phase is not acidic, more acid is added to the aqueous phase. Examples of the acid added as the pH adjuster include mineral acids such as phosphoric acid, sulfuric acid and nitric acid, such as citric acid, succinic acid, malic acid, glacial acetic acid, lactic acid, succinic acid, p-toluenesulfonic acid, and organic phosphonic acid. Examples thereof include organic acids. Of these, phosphoric acid not only functions as a pH adjuster, but also has an effect of enhancing the desensitizing effect, and is particularly excellent, 0.01 to 20% by weight based on the total weight of the desensitizing solution, Most preferably, it is contained in the range of 0.1 to 10% by weight.

  The desensitizing liquid used in the present invention preferably contains a wetting agent and / or a surfactant, whereby the applicability of the desensitizing liquid can be improved. Specific examples of the wetting agent include lower polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butylene glycol, pentanediol, hexylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, and tripropylene. Glycol, glycerin, sorbitol, pentaerythritol and the like can be mentioned, and particularly preferred is glycerin. Examples of the surfactant include nonionic surfactants such as polyoxyethylene alkylphenyl ether and polyoxyethylene polyoxypropylene block copolymer, such as fatty acid salts, alkyl sulfate hydrochloride, alkylbenzene sulfonates, alkyl naphthalene sulfonates. Anionic surfactants such as dialkylsulfosuccinic acid ester salts, alkylphosphoric acid ester salts, and naphthalenesulfonic acid formalin condensates, for example, amphoteric surfactants of betaine type, glycine type, alanine type, and sulfobetaine type can be used. These wetting agents and / or surfactants are contained in the range of about 0.5 to 10% by weight, more preferably 1 to 5% by weight, based on the total weight of the desensitizing solution. The desensitizing liquid used in the present invention may further contain a filler such as silicon dioxide, talc and clay in an amount of up to 2% by weight and a dye or pigment in an amount of up to 1% by weight. it can.

The desensitizing solution used in the present invention is composed of the hydrophilic aqueous solution as described above, but is described in each specification such as U.S. Pat. Nos. 4,253,999, 4,268,613, and 4,348,954. It is also possible to use an emulsifying type desensitizing liquid. The coating amount of the desensitizing solution is 0.001 to 50 g / m ² , preferably 0.01 to 10 g / m ² in terms of dry weight.

  Next, a printing plate precursor suitably used for the plate making apparatus of the present invention will be described.

  As a support that can be used for the printing plate precursor described above, a dimensionally stable plate-like material is suitable, for example, paper, plastic (for example, polyethylene, polypropylene, polystyrene, etc.) is laminated. Paper, metal plates (eg, aluminum, zinc, copper, etc.), plastic films (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, Polypropylene, polycarbonate, polyvinyl acetal, etc.), paper or plastic film on which a metal as described above is laminated or deposited. A preferable support includes a polyester film or an aluminum plate.

  As the support used for the printing plate precursor, it is preferable to use an aluminum plate that is lightweight and excellent in surface treatment, workability, and corrosion resistance. Aluminum materials used for this purpose include aluminum and aluminum-containing alloys such as JIS 1050 material, JIS 1100 material, JIS 1070 material, Al-Mg alloy, Al-Mn alloy, Al-Mn-Mg alloy, Al -Zr-based alloy, Al-Mg-Si-based alloy, or the like, or aluminum or aluminum alloy laminated or vapor-deposited plastic film or paper. Further, a composite sheet in which an aluminum sheet is bonded to a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327 may be used.

  The aluminum plate is subjected to surface treatment such as roughening treatment on the surface, and an image portion is formed on the surface to form a printing plate. In the roughening treatment, mechanical roughening, chemical roughening, and electrochemical roughening are performed alone or in combination. Moreover, it is also preferable to perform an anodizing process for ensuring the scratch resistance of the surface or a process for increasing hydrophilicity.

  The surface treatment of the support will be described below. Prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent or an alkaline aqueous solution for removing rolling oil on the surface may be performed as necessary. In the case of an alkali, treatments such as neutralization and smut removal may be performed with an acidic solution.

  Next, in order to improve the adhesion between the support and the image area and to provide water retention to the non-image area, a so-called graining process is performed to roughen the surface of the support. As specific means of this graining method, there is a mechanical graining method such as sandblasting, and there is a chemical graining method in which the surface is roughened with an etching agent made of alkali, acid or a mixture thereof. . In addition, an electrochemical graining method, a method of roughening the surface by adhering the granular material to the support material with an adhesive or a method having the effect, a continuous band or roll having fine irregularities A known method such as a roughening method in which unevenness is transferred by pressure bonding to a material can be applied.

  These roughening methods may be performed in combination, and the order, the number of repetitions, and the like can be arbitrarily selected. Since smut is formed on the surface of the support obtained by the roughening treatment, that is, the graining treatment as described above, a treatment such as washing with water or alkali etching is appropriately performed to remove the smut. Is generally preferred.

In the case of an aluminum support, after performing the pretreatment as described above, an oxide film is usually formed on the support by anodic oxidation in order to improve wear resistance, chemical resistance and water retention. Any electrolyte that forms a porous oxide film can be used as an electrolyte used for anodizing of an aluminum plate. Generally, sulfuric acid, phosphoric acid, oxalic acid, hydrochloric acid, nitric acid, boric acid, chromic acid, Sulfamic acid, benzenesulfonic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte. The treatment conditions for anodization vary depending on the electrolyte used and cannot be specified. However, in general, the electrolyte concentration is 1 to 80% solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / dm ^2. It is appropriate if the voltage is in the range of 1 to 100 V and the electrolysis time is in the range of 10 seconds to 5 minutes. The amount of the anodized film is suitably 1.0 g / m ² or more, but more preferably in the range of 2.0 to 6.0 g / m ^2. When the anodized film is less than 1.0 g / m ² , the printing durability is insufficient, or the non-image part of the printing plate is easily scratched, so that the ink adheres to the scratched part during printing. "Scratch dirt" is likely to occur.

  After the anodizing treatment, the aluminum surface may be sealed. Such sealing treatment is performed by immersing the substrate in a hot aqueous solution containing hot water and an inorganic salt or an organic salt, a water vapor bath, or the like. The aluminum support may be subjected to a hydrophilic treatment such as a silicate treatment with an alkali metal silicate or an immersion treatment in an aqueous solution of potassium fluorinated zirconate or phosphate.

An intermediate layer for improving the adhesion between the support and the image portion formed by the ink discharge head described above may be provided. In order to improve adhesion, the intermediate layer has an adhesive provided on a diazo resin, an aluminum compound such as a phosphonic acid or phosphoric acid compound, or an aluminum alkoxide, or an aluminum substrate described in JP-A-2001-109139. An organic silicone compound used for the layer may be used. The thickness of the intermediate layer is arbitrary, and it must be a thickness that can perform a uniform bond formation reaction with the upper image portion when exposed. Usually, the application ratio of about 1 to 100 mg / m ² is good as a dry solid, and 5 to 40 mg / m ² is particularly good. After the above-described treatment or undercoating is applied to the support surface, a back coat is provided on the back surface of the support as necessary. As such a back coat, a coating layer made of a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174 is used. Preferably used.

  As a preferable characteristic as a support for a printing plate, the center line average roughness is preferably 0.10 to 1.2 μm. By setting the thickness to 0.10 μm or more, the adhesion with the image portion becomes a certain level or more, and high printing durability can be maintained. Moreover, the smearing property at the time of printing can be made low by setting it as 1.2 micrometers or less. Furthermore, when the image portion is formed by exposure and development, the color density of the support is preferably 0.15 to 0.65 as the reflection density value. By making it blacker than 0.15, it is possible to prevent the image formation from being hindered by halation during image exposure, and by making it whiter than 0.65, the image can be viewed well in the plate inspection work after development. The plate inspection property can be increased.

  As mentioned above, although the plate-making apparatus of this invention was demonstrated in detail, of course, this invention is not limited to the said embodiment, Of course, in the range which does not deviate from the summary of this invention, various improvement and a change may be performed. .

  For example, a guide for guiding the printing plate precursor may be disposed between the belt conveyor and the application roller pair of the fixing unit.

  Further, in this embodiment, a fan is provided in the drying unit and hot air is blown to the printing plate precursor. However, the present invention is not limited to this, and printing is performed only by heating with a heater or only with a fan as necessary. The gum solution applied to the plate precursor may be dried.

  In the present invention, a plate surface protective film is formed on the printing plate precursor to obtain a finished planographic printing plate. However, it is necessary to form a plate surface protective film on the printing plate when used immediately for printing. If not, the printing plate precursor having the image fixed by the fixing unit can be used as it is as a printing plate for planographic printing.

It is the schematic front view which showed typically the structure of one Embodiment of the plate-making apparatus of this invention. (A)-(C) is a schematic front view which shows typically an example of the process of apply | coating a gum solution to the printing plate precursor P by the gum solution application part of the plate-making apparatus shown in FIG. 1, respectively. (A)-(F) is a schematic front view which shows typically an example of the process of conveying a printing plate precursor with the belt conveyor of the plate-making apparatus shown in FIG. 1, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Plate making apparatus 20 Supply tray 24 Inkjet head 26 Fixing part 28 Belt conveyor 30 Gum liquid application part 32 Drying part 34 Discharge tray 36 Conveying guide 38 Feed roller 40 UV lamp 42 Belts 44 and 46 Belt roller 48 Vertical movement mechanism 50 Drive source 52 Application roller pair 52a Immersion roller 52b Application roller 54 Gum liquid tank 56 Blower fan 57 Heater 58 Discharge roller pair 60 Conveyance guide 61 Cover P, P 'Printing plate precursor

Claims (2)

A plate making apparatus for producing a printing plate for lithographic printing,
An ink jet head that ejects ink droplets on a printing plate precursor according to an ejection signal to form an image portion;
A fixing unit disposed adjacent to the inkjet head and fixing the image portion formed by the inkjet head to the printing plate precursor;
A plate surface protective liquid application unit that is disposed above the fixing unit and applies a plate surface protective liquid to the printing plate precursor on which the image unit is formed;
A drying unit that is disposed adjacent to the plate surface protective liquid application unit and that dries the plate surface protective liquid applied in the plate surface protective liquid application unit;
A first transport unit including a first transport path for transporting the printing plate precursor during recording of the image unit by the inkjet head and fixing of the image unit in the fixing unit;
A second transport path having a second transport path for transporting the printing plate precursor sent from the fixing unit to the plate surface protective liquid coating unit;
A third transport path is provided above the first transport unit and transports the printing plate precursor when the plate surface protection liquid is applied in the plate surface protection liquid application unit and when the plate surface protection liquid is dried in the drying unit. A third conveying unit,
The second transport unit switches between the connection between the second transport path and the first transport path and the connection between the second transport path and the third transport path, and at the same time in the second transport path. A plate making apparatus, wherein the plate making apparatus is a conveyance path switching reversal conveyance unit that also reverses the conveyance direction of the printing plate precursor. The second transport unit has a position where one end on the fixing unit side is connected to the third transport path of the plate surface protective liquid coating unit from a position connected to the first transport path of the fixing unit. Up to the other end, with a conveyor that can move up and down,
The conveyor constitutes the second transport path,
When the printing plate precursor is sent out from the fixing unit, the one end is in a position connected to the first conveyance path of the fixing unit;
After the printing plate precursor is sent out from the first conveyance path of the fixing unit to the second conveyance path, the one end is centered on the other end and the one end of the plate surface protective liquid application unit is Moved up to the position connected to the 3 transport path,
After a part of the printing plate precursor is carried into the third transport path of the plate surface protective liquid coating unit and the transport of the printing plate precursor by the third transport unit is started, the one end portion is The plate making apparatus according to claim 1, wherein the fixing unit starts moving to the substantially horizontal position connected to the first conveyance path.

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