JP2006091361A - Planographic printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a planographic printing method in which a planographic printing plate developable on a printing machine is inspected before being mounted on the printing machine. <P>SOLUTION: An original plate of the planographic printing plate 12 developable on the printing machine is exposed so as to form a latent image in an exposing step. Next, the planographic printing plate 12 on which the latent image is formed in a developing step is immersed in immersion water 34 to which ultrasonic vibration is applied and a non-image portion of an image recording layer of the planographic printing plate 12 is scraped therefrom with a rolling brush roll 44. Finally, in a printing step, the planographic printing plate 12 of which the non-image portion is scraped therefrom is mounted on the printing machine 50 and subjected to printing. Thereby, the planographic printing plate 12 developable on the printing machine is inspected before being mounted on the printing machine 50. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lithographic printing method for printing a lithographic printing plate that can be developed on a printing press.

  In the lithographic printing method, printing is performed with a lithographic printing plate that can be developed on a printing press (a lithographic printing plate that can be developed by defilming and dispersing on the printing press with water or dampening water after exposure) on the printing press. There is a known method (see, for example, Patent Document 1). In such a lithographic printing method, the exposed lithographic printing plate is placed on, for example, a printing cylinder of a printing press, and the photosensitive layer in the non-image area (unexposed area) is removed by film removal with water or a fountain solution. And develop.

However, in this conventional lithographic printing method, an exposed lithographic printing plate that can be developed on a printing press cannot distinguish between an image portion (exposed portion) and a non-image portion (unexposed portion). Cannot verify the plate. An image portion and a non-image portion can be identified by the printer only after the photosensitive layer of the non-image portion is removed, and plate inspection is possible.
JP-A-9-123387

  In view of the above facts, an object of the present invention is to provide a lithographic printing method capable of inspecting a lithographic printing plate that can be developed on a printing press before mounting the printing plate on the printing press.

  The lithographic printing method of the present invention described in claim 1 includes an exposure step of exposing a lithographic printing plate precursor that can be developed on a printing press to form a latent image, and the lithographic printing plate on which the latent image is formed. A development step of immersing in immersion water to which ultrasonic vibration is applied and scraping off a non-image portion of the image recording layer of the lithographic printing plate by a scraping means, and the lithographic printing plate from which the non-image portion is scraped off And a printing process for printing on a printing machine.

  Here, a lithographic printing plate that can be developed on a printing press refers to a lithographic printing plate that can be developed by defilming and dispersing with water or a dampening solution on the printing press after exposure.

  According to the lithographic printing method of the present invention described in claim 1, first, in the exposure step, a lithographic printing plate precursor that can be developed on a printing press is exposed to form a latent image. Next, in the development process, the lithographic printing plate on which the latent image is formed is immersed in immersion water to which ultrasonic vibration is applied, and the non-image portion of the image recording layer of the lithographic printing plate is scraped off by a scraping means. Finally, in the printing process, the lithographic printing plate from which the non-image area is scraped is mounted on a printing machine and printed. Thus, a lithographic printing plate that can be developed on the printing press can be inspected before being mounted on the printing press.

  As described above, according to the lithographic printing method of the present invention, a lithographic printing plate that can be developed on a printing press can be inspected before being mounted on the printing press.

A planographic printing method according to the present invention will be described with reference to the drawings. FIG. 1 shows an exposure / development apparatus 10 and a printing machine 50 to which the planographic printing method of the present invention is applied.
(Lithographic printing plate)
The original plate of the lithographic printing plate 12 used in the exposure and development apparatus 10 is a lithographic printing plate that can be developed on a printing press (a lithographic printing plate that can be developed by defilming and dispersing on the printing press with water or fountain solution after exposure) ) Is the original version. That is, the lithographic printing plate 12 on which the image has been exposed is rinsed with water or an aqueous liquid (water or an aqueous liquid having the same component as the fountain solution used in the printing press or an aqueous liquid obtained by adding a required chemical to water). The film is dispersed and developed.

  The original plate of the planographic printing plate 12 includes an image recording layer formed on the surface of a support made of aluminum or an aluminum alloy. The image recording layer contains a hydrophobizing precursor and a photothermal conversion agent. Here, the hydrophobized precursor means a material capable of forming a hydrophobic region by exposure in a hydrophilic thermosensitive layer.

As the original plate of the lithographic printing plate 12, for example, one containing a microcapsule enclosing a heat-reactive compound in the image recording layer, a polymerization initiator and a photothermal conversion agent can be used. In addition, since the polymerization initiator such as a radical initiator or an acid generator and the photothermal conversion agent may be present either inside or outside the microcapsule, they are added to at least one of the image recording layer matrix. It only has to be done. However, from the viewpoint of storage stability, the polymerization initiator is preferably added to the image recording layer matrix. From the viewpoint of sensitivity, the photothermal conversion agent is preferably added in the microcapsule.
(Overall configuration of exposure developing apparatus and printing machine)
As shown in FIG. 1, the exposure and development apparatus 10 includes an exposure unit 14. A plurality of conveyance rollers 16 are arranged on the carry-in side of the exposure unit 14, and the original of the planographic printing plate 12 is carried into the laser recording unit 18 of the exposure unit 14 by the rotation of the conveyance roller 16. Yes.

  A cylindrical outer drum 20 is rotatably arranged on the laser recording unit 18, and one lithographic printing plate 12 can be attached to and detached from the outer drum 20. The outer drum 20 rotates in the forward rotation direction (arrow R1 direction) from when the original plate of the planographic printing plate 12 is carried in until exposure, and in the reverse rotation direction (arrow R2 direction) after the exposure until the planographic printing plate 12 is carried out. It is supposed to be.

  A chuck mechanism 22 and a guide roller 24 are disposed to face the outer peripheral surface of the outer drum 20. The chuck mechanism 22 checks the front end portion and the rear end portion of the lithographic printing plate 12 against the outer drum 20 respectively, and the guide roller 24 presses the lithographic printing plate 12 onto the outer peripheral surface of the outer drum 20 to be in close contact therewith. Wrap as you guide.

  An exposure head 26 is disposed facing the outer drum 20. The laser recording unit 18 including the exposure head 26 scans and exposes the original of the lithographic printing plate 12 with an infrared laser (hereinafter referred to as “IR laser L”) modulated based on digital image information. An image (latent image) corresponding to the digital image information is formed on the original plate.

  Here, the exposure head 26 can be moved along the sub-scanning direction by a feed mechanism (not shown), and an IR laser L from an LD light source device (not shown) is attached to the outer drum 20 by an imaging optical system 28. An image is formed on the original of the planographic printing plate 12, and the image is exposed with a beam spot having a predetermined shape and size. The imaging optical system 28 includes a plurality of lenses, which are not shown in FIG.

  A transport roller 16 is provided on the downstream side (right side in FIG. 1) of the laser recording unit 18, and the planographic printing plate 12 is unloaded from the laser recording unit 18 and developed downstream by the rotation of the transport roller 16. It is conveyed to the part 30.

  The developing unit 30 is provided with a liquid tank 32, and immersion water 34 is stored in the liquid tank 32. Surfactant or abrasive (such as silica sand) that can be treated with sewage (for example, contained in household detergent) is added to the immersion water 34 for the purpose of promoting development. Here, sewage treatment is possible when the added aqueous solution satisfies the drainage standards based on the Water Pollution Control Law and the regulations stipulated by each prefecture.

  In the present embodiment, as the immersion water 34, water having a sewage-treatable surfactant or abrasive added thereto is used, but tap water can also be applied.

  The temperature of the immersion water 34 is maintained and controlled at 20 ° C. to 50 ° C. (controlled within a control range of ± 3 ° C.) by a water temperature control means (not shown), and the water level of the immersion water 34 is controlled by a water level control means (not shown). ing. The lithographic printing plate 12 is immersed in the immersion water 34.

  An insertion portion 36 into which the lithographic printing plate 12 can be inserted is formed on the upstream side (left side in the figure) of the liquid tank 32 so that the lithographic printing plate 12 supplied from the exposure unit 14 can be inserted. In the liquid tank 32, a pair of conveying rollers 38 is disposed on the insertion portion 36 side. The planographic printing plate 12 is fed between the conveyance roller pair 38 by being inserted along the insertion direction (arrow A direction) from the insertion portion 36. The conveyance roller pair 38 can be driven to rotate, and guides and conveys the planographic printing plate 12 while being immersed in the immersion water 34. The lithographic printing plate 12 is inserted from the insertion unit 36 with the photosensitive layer as the image recording layer facing downward when processed by the developing unit 30.

  An ultrasonic oscillation element 40 is disposed at the bottom of the liquid tank 32, and an ultrasonic oscillation device 42 is connected to the ultrasonic oscillation element 40. The ultrasonic oscillating device 42 generates an ultrasonic wave when energized, and the ultrasonic oscillating element 40 has a function of converting this into mechanical vibration. The ultrasonic oscillator 42 emits an ultrasonic wave having an output with a frequency of 20 to 200 kHz and 50 to 2000 W, and the ultrasonic wave excites the immersion water 34 in the liquid tank 32 by the ultrasonic oscillator 40.

  Removal of the non-image portion of the image recording layer in the planographic printing plate 12 is promoted by the immersion water 34 being excited. In order to remove the non-image portion of the image recording layer in the planographic printing plate 12 and not peel and deteriorate the image portion, the frequency F applied to the immersion water 34 is preferably 20 kHz ≦ F ≦ 200 kHz. The feed speed V of the lithographic printing plate 12 in the immersion water 34 is preferably 2 mm / sec ≦ V ≦ 50 mm / sec.

  A rotating brush roll 44 as scraping means is disposed on the downstream side in the liquid tank 32 (right side in FIG. 1). The rotating brush roll 44 rotates at a predetermined rotation speed and rubs the surface of the image recording layer of the planographic printing plate 12 to scrape off the non-image portion of the image recording layer. As the rotating brush roll 44, a material in which nylon fibers or the like are planted is used. The material, thickness, length, flocking density, and the like of the brushed portion of the rotating brush roll 44 and the rotational speed of the rotating brush roll 44 are appropriately determined in consideration of the removability of the non-image portion and the influence on the image portion. select.

  The arrangement position of the rotating brush roll 44 is not limited as long as it is in the immersion water 34 and can rub the surface of the image recording layer of the planographic printing plate 12. Left side in 1).

  Further, as the scraping means, instead of the rotating brush roll 44, a Morton roll as another rubbing member may be used. Here, the Molton roll is obtained by winding a non-woven fabric such as felt on a rubber roller or a metal roller, and the non-woven fabric uses a material mainly composed of cotton. The material and thickness of the nonwoven fabric part used for the molton roll and the thickness and length of the fibers constituting the nonwoven fabric are also appropriately selected in consideration of the removability of the non-image area and the influence on the image area.

  A conveyance roller pair 46 is disposed on the downstream side (right side in FIG. 1) of the rotation brush roll 44 in the conveyance direction, and can be driven to rotate. The planographic printing plate 12 is transported in a substantially horizontal state to the liquid level of the immersion water 34 stored in the liquid tank 32 by the upstream transport roller pair 38 and the downstream transport roller pair 46. . The conveyance roller pair 46 guides and conveys the planographic printing plate 12 to the discharge unit 48 of the developing unit 30 while pulling it out of the immersion water 34.

  The printing machine 50 to which the developed lithographic printing plate 12 is mounted is a general printing machine and includes a plate cylinder 52 to which the lithographic printing plate 12 is attached. A water roller 54 and an ink roller 56 are arranged around the plate cylinder 52, and the water roller 54 and the ink roller 56 rotate while being in contact with the planographic printing plate 12 mounted on the plate cylinder 52. Yes. As a result, ink is attached to the planographic printing plate 12 only in the image area.

  A blanket cylinder 58 is provided so as to face the plate cylinder 52, and the blanket cylinder 58 is rotatable while the peripheral surface is in contact with the planographic printing plate 12. Thereby, the ink adhering to the image portion of the planographic printing plate 12 is transferred to the peripheral surface of the blanket cylinder 58.

A pressure drum 60 is disposed on the blanket cylinder 58 across the conveyance path of the printing paper P, and the blanket cylinder 58 and the impression cylinder 60 can rotate while holding the printing paper P therebetween. As a result, the ink transferred to the blanket cylinder 58 is transferred to the printing paper P.
(Lithographic printing method)
-Exposure process-
In the exposure step, the original of the planographic printing plate 12 that can be developed on the printing press is exposed to form a latent image.

  When the original of the lithographic printing plate 12 is conveyed by the conveyance roller 16 and is conveyed to the vicinity of the upper end of the outer drum 20, the end of the original of the lithographic printing plate 12 is placed on the outer peripheral surface of the outer drum 20 by the chuck mechanism 22. While chucking, the outer drum 20 starts to rotate in a predetermined forward rotation direction (the direction of arrow R1 in FIG. 1). Thus, the original plate of the planographic printing plate 12 whose end is constrained on the outer peripheral surface of the outer drum 20 is wound on the outer peripheral surface of the outer drum 20 by being pressed by the guide roller 24 so as to be in close contact therewith.

  In this state, the outer drum 20 is rotated for main scanning, and the IR laser L emitted from the exposure head 26 is moved while the exposure head 26 is moved in the sub-scanning direction (sub-scanning) by a feed mechanism (not shown). The original of the lithographic printing plate 12 is irradiated and scanning exposure is performed on the original of the lithographic printing plate 12.

When the exposure process for the original of the planographic printing plate 12 is completed, the outer drum 20 rotates in the reverse direction (in the direction of arrow R2 in FIG. 1), and the chuck mechanism 22 moves the rear end and the front end of the planographic printing plate 12 to the outer drum. Release sequentially from 20. In conjunction with this, the transport roller 16 on the downstream side rotates to guide the planographic printing plate 12 to the developing unit 30.
-Development process-
In the development process, the lithographic printing plate 12 on which the latent image is formed is immersed in immersion water 34 to which ultrasonic vibration is applied, and the non-image portion of the image recording layer of the lithographic printing plate 12 is scraped off by the rotating brush roll 44. develop.

  The planographic printing plate 12 is inserted from the insertion portion 36 of the developing unit 30 along the insertion direction (arrow A direction). At this time, the image recording layer of the planographic printing plate 12 is directed downward. The inserted lithographic printing plate 12 is fed between the conveyance roller pair 38 and guided and conveyed while being immersed in the immersion water 34 to which ultrasonic vibration is applied from the ultrasonic oscillator 40 by the ultrasonic oscillator 42. . Further, on the downstream side in the liquid tank 32, the rotating brush roll 44 rubs the surface of the image recording layer of the planographic printing plate 12 and scrapes off the non-image portion of the image recording layer of the planographic printing plate 12. Thereby, the planographic printing plate 12 is reliably developed. The developed lithographic printing plate 12 is discharged from the discharge unit 48 of the developing unit 30 by the conveying roller pair 46.

At this time (before the planographic printing plate 12 is mounted on the printing machine 50), the planographic printing plate 12 can be placed on the plate inspection table 70 and visually inspected.
-Printing process-
In the printing process, the lithographic printing plate 12 with the non-image area scraped off is mounted on the printing machine 50 and printed.

  The planographic printing plate 12 is wound around the plate cylinder 52 and the printing process is started. The water roller 54 and the ink roller 56 rotate while being in contact with the lithographic printing plate 12 mounted on the plate cylinder 52, and ink is attached only to the image portion of the lithographic printing plate 12. Ink adhering to the image portion of the planographic printing plate 12 is transferred to the peripheral surface of the blanket cylinder 58. The blanket cylinder 58 and the impression cylinder 60 rotate while sandwiching the printing paper P to convey the printing paper P in the discharge direction (arrow B direction), and the ink transferred to the blanket cylinder 58 is transferred to the recording paper P. Is done.

1 is an overall configuration diagram showing an exposure development apparatus and a printing press according to an embodiment of the present invention.

Explanation of symbols

12 Planographic printing plate 34 Immersion water 44 Rotating brush roll (scraping means)
50 printing machine

Claims (1)

An exposure step of exposing a lithographic printing plate precursor that can be developed on a printing press to form a latent image;
A development step of immersing the lithographic printing plate on which the latent image is formed in immersion water to which ultrasonic vibration is applied, and scraping off a non-image portion of an image recording layer of the lithographic printing plate by a scraping means;
A printing process in which the lithographic printing plate scraped off of the non-image part is mounted on a printing machine and printed;
A lithographic printing method comprising:

Images