JP2011039171A - Development processing device for planographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a development processing device for a planographic printing plate that enables stable development processing, without exchanging a means for promoting development in a developing tank over a long period of time, so that the load required for performing maintenance in terms of time and work is reduced. <P>SOLUTION: The development processing device for a planographic printing plate includes a means to receive information whether a plate material to be processed is a planographic printing plate or a key plate and a means for making the means for promoting development so that the means for promoting development in the developing tank does not contact the plate surface of the key plate. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lithographic printing plate development processing apparatus, and more particularly to a lithographic printing plate that forms an image and a development processing apparatus that processes a discarded plate that does not form an image.

  Conventionally, color printing using a lithographic printing plate is performed by preparing printing plates for each color of black (K), yellow (Y), magenta (M), and cyan (C) on the same paper material and repeating the printing process. It is common to form. In addition to the above four colors, special colors may be added.

  In recent years, demand for color printing paper in newspapers has increased, but the printing paper surface in black is still a large number. Therefore, in an actual printing field, printing in which a color paper surface and a black monochrome paper surface are mixed is performed.

  FIG. 7 is an explanatory diagram showing an example of a paper layout when a newspaper is color-printed with a planographic printing plate. FIG. 8 is an explanatory diagram of a usage example of a printing plate and a discarding plate used when printing the paper surface shown in FIG. When printing on the color paper surface on the right side of the printing paper surface as shown in FIG. 7 and the black color paper surface on the left side of the printing paper surface, as shown in FIG. 8, black (K), The printing plates a1 to a8 are used so as to correspond to the respective colors of yellow (Y), magenta (M), and cyan (C). In FIG. 8, among the printing plates a1 to a4 where black monochrome printing is performed, portions a2 to a4 corresponding to the colors Y, M, and C are referred to as plates that do not have an image on the entire surface, commonly called discarding plates. It is supported by installing the plate on the printing press. The discarded plate system is described in, for example, JP-A-3-175090 (Patent Document 1).

  As described in the above-mentioned Patent Document 1, as a discarded plate used for newspaper color printing, there is a plate material obtained by performing a surface roughening treatment or a hydrophilic treatment alone or in combination on a metal support. Proposed. Also, a plate provided with a primer made of a water-soluble compound and a water-insoluble non-photosensitive resin layer on a metal support having a hydrophilic surface as disclosed in JP-A-11-240266 (Patent Document 2). Materials have been proposed.

  In addition to the applied undercoat layer and the like, dust or dirt adheres to the discarded plate surface before use during storage. For this reason, when the discarded plate is used for printing without any treatment, printing stains are generated. Therefore, it is necessary to remove the undercoat layer on the surface of the plate and the attached dust and dirt by a development process immediately before use. For this reason, although it is not necessary to form an image on the discarded plate, development processing and gumming processing by a development processing device are performed in the same manner as a normal lithographic printing plate.

  To improve hydrophilicity, the primer layer applied to the discarded plate, the water-insoluble non-photosensitive resin layer, and the dust and dirt adhering to it are quickly dissolved by immersion in a developer or shower treatment. The roughened surface is exposed. At this time, when a rubbing treatment is carried out by a development accelerating means such as a brush roll or a Morton roll in the development processing portion, the exposed roughened surface exhibits a remarkably large resistance as compared with the processing of the lithographic printing plate. As a result, development acceleration means such as a brush roll or a molton roll in the developing portion are significantly faster than those in the case where only a normal lithographic printing plate is developed, and the period that can be used before replacement is shortened and maintenance is required. There was a problem of increasing the time and labor burden. In particular, when a Morton roll is used as the development accelerating means, the abrasion of the hair end portion of the Molton that rubs against the plate surface becomes remarkable, and frequent Morton member replacement is necessary for stabilizing the development effect.

JP-A-3-175090 JP-A-11-240266

  Accordingly, an object of the present invention is to provide a lithographic printing plate development processing apparatus capable of performing stable development processing without replacing the development accelerating means in the developing tank over a long period of time and reducing the time and labor burden required for maintenance. Is to provide.

It has been found that the above object of the present invention can be achieved by the development processing apparatus for a lithographic printing plate described below.
1. Means for receiving information on whether the plate material to be processed is a planographic printing plate or a discarded plate; and means for retracting the development promoting means so that the development promoting means in the developing tank does not contact the plate surface of the discarded plate; A lithographic printing plate development processing apparatus comprising:

  According to the present invention, there is provided a development processing apparatus for a lithographic printing plate that enables stable development processing without replacing development promoting means in a developing tank over a long period of time, and that reduces the time and labor burden required for maintenance. be able to.

It is a schematic side view showing an example of a development processing apparatus for a lithographic printing plate of the present invention. It is a flowchart which shows the process sequence in the development processing apparatus for lithographic printing plates when plate | version | printing type is received before exposure. It is a flowchart which shows the process sequence in the development processing apparatus for lithographic printing plates when the plate type is received before the development processing. It is a bearing structure of a pair of developing unit rolls constituted by a rotating development promoting means and a backup roll, and is a schematic diagram of a system in which the position of the development promoting means is regulated by the position of a rotating cam. FIG. 5 is a schematic view of a system that is a bearing structure of a pair of developing unit rolls constituted by a rotating development promoting means and a backup roll, and restricts the position of the development promoting means by a piston pushing position. FIG. 5 is a schematic diagram of a system of a bearing structure of a pair of developing unit rolls constituted by a rotating development promoting means and a backup roll, in which the position of the development promoting means is restricted by the insertion position of the wedge plate. It is explanatory drawing which shows an example of the paper surface layout at the time of carrying out color printing of the newspaper with a lithographic printing plate. It is explanatory drawing of the usage example of the printing plate used when printing the paper surface shown in FIG. 7, and a discarding plate.

  The lithographic printing plate development processing apparatus of the present invention will be described in detail. In general, development processing of a lithographic printing plate is performed using a development processing apparatus. The development processing device is composed of a development processing unit, a water washing processing unit, a gum processing unit, and a drying unit (not shown) in the order of processes to be processed, and conveys an exposed printing plate or discarded plate horizontally or while being immersed in each processing tank. On the other hand, each treatment liquid pumped up from each treatment tank is sprayed on the plate surface by spray means or the like to perform each treatment, and then a drying treatment is performed by a drying unit (not shown).

  The development processing apparatus according to the present invention has means for receiving identification information indicating whether the type of plate processed before the start of processing operation is a planographic printing plate or a discarded plate. As this means, a method for receiving plate type identification information from the setter to be exposed, the glossiness of the upper surface of the processing plate is measured before the insertion port of the development processing apparatus, and whether it is a lithographic printing plate from the obtained information, There are a method of receiving identification information as to whether it is a discarded version, and a method of receiving information identifying whether a worker is a lithographic printing plate or a discarded version.

  FIG. 2 is a flowchart showing a processing procedure in the lithographic printing plate development processing apparatus when a plate type is received before exposure. The plate type identification information is received by the development processing device before the plate exposure processing. As a means at this time, there are a method of receiving plate type identification information from the setter to be exposed, and a method of inputting and receiving information identifying whether the operator is a planographic printing plate or a discarded plate. The plate material type information received by the development processing apparatus is appropriately processed by a control mechanism inside the development processing apparatus, and in the case of a lithographic printing plate, development processing using a development accelerating means, water washing processing, gumming processing, and drying processing. Repeat in order. In the case of a discarded plate, the development accelerating means in the developing tank is evacuated, the development process without using the development accelerating means, the washing process, the gumming process, and the drying process are sequentially performed. Perform the recovery procedure.

  FIG. 3 is a flowchart showing a processing procedure in the lithographic printing plate development processing apparatus when the plate type is received before the development processing. The plate type identification information is received by the development processing apparatus before the development processing of the plate. As a means at this time, a method of measuring the glossiness of the upper surface of the processing plate before the insertion port of the development processing apparatus and receiving information identifying whether it is a planographic printing plate or a discarded plate from the obtained information There is a method of inputting and receiving information identifying whether the worker is a lithographic printing plate or a discarding plate. The plate material type information received by the development processing apparatus is appropriately processed by a control mechanism inside the development processing apparatus, and in the case of a lithographic printing plate, development processing using a development accelerating means, water washing processing, gumming processing, and drying processing. Repeat in order. In the case of a discarded plate, the development promoting means in the developing tank is evacuated, the development process without using the development promoting means, the water washing process, the gumming process, and the drying process are sequentially performed. Perform the recovery procedure.

  The plate processing procedure in the present invention will be described below with reference to the schematic side view of an example of the lithographic printing plate development processing apparatus of the present invention shown in FIG. The planographic printing plate or the discarded plate exposed by an exposure apparatus not shown in FIG. 1 is processed through the passage route 100 in FIG. The plate inserted from the insertion port of the developing machine is conveyed into the developing unit by the conveying rolls 1 and 2 with the image forming layer surface or the roughened surface for discarding plate on the upper side, and passes through the submerged conveying rollers 3 and 4. It is immersed in a developer whose temperature is controlled at a constant temperature.

  While the image forming layer of the lithographic printing plate immersed in the developer is in a state in which the non-image part is swollen by the developer and is easily eluted, the transport rolls 1, 2, 10, 11 and the submerged transport roll 3, 4, 8 and 9 are transported in the developer. The swollen non-image area is rubbed by the development promoting means 6 to promote elution. On the other hand, the image portion remains as an image without being eluted in the developing tank (A).

  On the other hand, when the discarded plate is immersed in the developing solution, the undercoat layer on the plate surface, the water-insoluble non-photosensitive resin layer, and the dust and dirt are rapidly dissolved or removed while the transport rolls 1, 2, 10 are used. , 11 and submerged transport rollers 3, 4, 8, and 9 are transported in the developer. Since the development accelerating means 6 is retreated above the upper surface of the discarded plate based on the plate identification information obtained in advance, the processing in the development processing unit is finished without contacting the plate surface.

  The developer tank (A) for storing the developer is appropriately replenished with a developer replenishment stock solution and a diluting water from a development replenishment stock solution tank and a water supply tank (not shown) so that the stored developer does not deteriorate due to the processing of the plate. It is desirable. In addition, when the power of the development processing apparatus is turned on or off, the replenisher and the replenisher are replenished from the replenisher tank and the water tank so that the developer does not deteriorate due to contact with air or the like. It is also desirable to make it appropriately. Further, the developing tank may be supplemented with the same amount of diluted water as the evaporated water so as to compensate for the natural evaporation when the power of the development processing apparatus is turned on or off.

  In FIG. 1, the development method by the immersion method in which the plate to be processed is inserted into the developer for the developing tank (A) is shown. Instead, the plate to be processed is transported horizontally and a shower pipe or the like is used. A developing method in which a developing solution is jetted or a developing method in which a developing solution is applied on a plate to be processed may be used.

  In the developing apparatus shown in FIG. 1, an example in which one development promoting unit 6 is installed is shown, but a plurality of development promoting units may be installed. Moreover, you may install in combination with another image development promotion means, such as an ultrasonic generator.

  The purpose of the planographic printing plate or discarded plate processed in the development processing section is to remove the alkaline developer remaining on the plate surface after development in the water washing processing section, and to reduce the carry-in of alkaline solution to the gum part in the next process The plate surface is washed with water sprayed from the shower pipe 14. In FIG. 1, the cleaning method using water sprayed from the shower pipe 14 is shown, but instead of this, a cleaning method or the like using a plurality of transport rolls and submerged transport rolls in the water washing tank (B) is used. Also good.

  In the gum processing unit, the gum solution is sprayed from the shower pipe 20, and an appropriate amount of the gum solution is applied to the surface of the plate by the gum unit conveying and squeezing rolls 22 and 23, so that the image portion of the lithographic printing plate that has become alkaline is obtained. Returning to acidity suppresses damage to the image area due to development, and prevents stains and scratches on the non-image area. In FIG. 1, the gum solution application method using the gum portion shower pipe 20 and the gum portion conveying / drawing rolls 22 and 23 is shown, but instead, the gum solution application method using a gum solution supply pipe, a doctor blade, and an application roll is used. It may be used. Since the liquid is applied to the entire surface regardless of the image area and the non-image area, the processing capacity of the plate can be reduced without distinguishing between the lithographic printing plate and the discarded plate in the gum tank (C) for storing the applied gum. If necessary, supplement the gum replenishment stock solution and dilution water as appropriate. Alternatively, an appropriate amount of gum replenishment stock solution and dilution water may be mixed and supplied for each plate processing.

  The drying section (not shown in FIG. 1) is provided with drying means such as a hot air supply means such as a blower or a heat generation means, and the hot air is blown onto the lithographic printing plate and the discarded plate to apply the gum solution applied to the plate material. Dry. The printing plate and the discarded plate dried by the drying unit are discharged from the discharge port.

  Next, means for retracting the development accelerating means so that the development accelerating means in the developing tank of the development processing apparatus of the present invention does not come into contact with the plate surface of the discarded plate will be described. As a means for retracting the development accelerating means in the developing tank so as not to come into contact with the plate surface of the discarded plate, a system in which the position of the development accelerating means is regulated by the position of the rotating cam, and the position of the development accelerating means is regulated by the pushing position of the piston. Examples thereof include a system and a system in which the position of the development accelerating means is regulated by the insertion position of the wedge plate.

  FIG. 4 shows a bearing structure of a pair of developing unit rolls constituted by a development promoting means and a backup roll that rotate in the development processing apparatus of the present invention, and a model of a system in which the position of the development promoting means is regulated by the position of the rotating cam. FIG. FIG. 4A is a view of the bearing portion and the rotating cam as viewed from the side of the development processing apparatus. FIG. 4B is a view of the bearing portion and the rotating cam as viewed from the direction of the insertion port of the development processing apparatus. FIG. 4C is a view of the bearing portion and the rotating cam as viewed from above the development processing apparatus. As shown in FIG. 4B, the rotation shaft 32 of the development promoting means 6 is supported by a bearing member 31. The rotation shaft 35 of the backup roll 33 that supports the planographic printing plate or the discarding plate is supported by a bearing member 34.

  The bearing member 31 rotatably supports the rotating shaft 32 of the development promoting means 6, and the bearing member 34 rotatably supports the rotating shaft 35 of the backup roll 33. Further, as shown in FIG. 4C, the bearing member 31 has a rectangular outer shape, and has a convex portion 46 that fits into a groove portion formed on the side plate of the developing portion so that the position can be regulated. The

  As shown in FIG. 4A, a position regulating coil spring or elastic rubber 36 is inserted into the gap between the upper portion of the bearing member 31 and the development processing unit side plate 41. With this and a cam plate 37, which will be described later, the development accelerating means 6 is restricted in position and given a predetermined pressure.

  As shown in FIG. 4B, the outer portion of the bearing member 31 is shaped to protrude slightly from the outer surface of the development processing unit side plate 41. As shown in FIG. 4A, a cam plate 37 described later is mounted on the lower side of the bearing member 31.

  As shown in FIG. 4A, the cam plate 37 is supported by the rotating shaft 38. The position of the cam plate 37 is determined by the control device 40 of the development processing apparatus and the motor 39 that has received the instruction. When the control device 40 of the development processing apparatus recognizes the plate to be processed as a lithographic printing plate, the motor 39 causes the development promoting means 6 to contact and rotate on the upper surface of the printing plate with a predetermined pressing pressure according to an instruction from the control device 40. The position of the cam plate 37 is controlled so as to scrape off the non-image portion of the image forming layer.

  When the control device 40 of the development processing apparatus recognizes the processed plate material as a discarded plate, the motor 39 rotates the rotation shaft 38 to the right in FIG. And the bearing member 31 is pushed up to a position where it is retracted so that the development accelerating means 6 does not come into contact with the upper surface of the discarded plate (the position indicated by the dotted line in FIG. 4A). The retreat distance necessary for the development accelerating means 6 and the discarded plate not to be in contact is sufficient for the plate surface and the development accelerating means 6 not to be in contact, specifically 2 to 5 mm. When the length is shorter than 2 mm, it is not preferable because there is a possibility of contact due to vibration or the like when the plate is conveyed. When the processing of the discarded plate is completed, the motor 39 rotates the rotating shaft 38 to the left side according to an instruction from the control device 40 to control the position of the cam plate 37, and the bearing member 31 is returned to the original position, thereby developing promotion means. 6 evacuation is canceled.

  Further, the position control of the bearing member 31, the development promoting means 6 and the rotating shaft 32 by the cam 39 and the rotating shaft 38, the developing device control device 40 and the motor 39 which receives the instruction is controlled by the pressing force of the developing promoting means 6. It is also used for control. By inputting a preferable pressing pressure to the control device 40 of the development processing apparatus, it is possible to select an effective pressing pressure when processing the types of plate materials and plates having different thicknesses.

  FIG. 5 shows a bearing structure of a pair of developing unit rolls constituted by a rotating development promoting means and a backup roll in the development processing apparatus of the present invention, in which the position of the development promoting means is regulated by the pushing position of the piston. It is a schematic diagram. FIG. 5A is a view of the bearing portion and the rotating cam as viewed from the side of the development processing apparatus. FIG. 5B is a view of the bearing portion and the rotating cam as viewed from the direction of the insertion port of the development processing apparatus. FIG. 5C is a view of the bearing portion and the rotating cam as viewed from above the development processing apparatus. As shown in FIG. 5B, the rotation shaft 32 of the development promoting device 6 is supported by the bearing member 31. The rotation shaft 35 of the backup roll 33 is supported by a bearing member 34. The functions of the bearing member 31, the development promoting means 6, the rotating shaft 32, the bearing member 34, the backup roll 33, the rotating shaft 35, the convex portion 46 of the bearing member 31, the position regulating coil spring or the elastic rubber 36 are described above. Since it is the same as an example, description is abbreviate | omitted in order to avoid duplication.

  As shown in FIG. 5B, the outer portion of the bearing member 31 is shaped to protrude slightly from the outer surface of the development processing unit side plate 41. A piston 42 and a cylinder 43 which will be described later are mounted on the lower side of the bearing member 31.

  The push-out amount of the piston 42 is determined by the cylinder 43 that has received an instruction from the control device 40 of the development processing apparatus. When the control device 40 of the development processing apparatus recognizes the plate material to be processed as a lithographic printing plate, the cylinder 43 is rotated in contact with the upper surface of the printing plate by the development promoting means 6 with a predetermined pressing pressure according to an instruction from the control device 40. The amount of piston 42 pushed out is controlled so as to scrape off the non-image portion of the image forming layer.

  When the control device 40 of the development processing apparatus recognizes the plate to be processed as a discarded plate, the cylinder 43 is pushed out from the piston 42 according to an instruction from the control device 40 so that the development promoting means 6 does not contact the upper surface of the discarded plate. The bearing member 31 is pushed up to the retracted position (the position indicated by the dotted line in FIG. 5A). The retreat distance necessary for the development accelerating means 6 and the discarded plate not to be in contact is sufficient for the plate surface and the development accelerating means 6 not to be in contact, specifically 2 to 5 mm. When the length is shorter than 2 mm, it is not preferable because there is a possibility of contact due to vibration or the like when the plate is conveyed. When the processing of the discarded plate is completed, the cylinder 43 lowers the piston 42 and returns the bearing member 31 to the original position in accordance with an instruction from the control device 40, and releases the development accelerating means 6.

  Further, the position control of the bearing member 31, the development promoting means 6 and the rotating shaft 32 by controlling the protrusion amount of the cylinder 43 and the piston 42 which received the instruction of the control device 40 of the development processing apparatus is performed by the pressure of the development promoting means 6. Also used for control. By inputting a preferable pressing pressure to the control device 40 of the development processing apparatus, it is possible to select an effective pressing pressure when processing the types of plate materials and plates having different thicknesses.

  FIG. 6 shows a bearing structure of a pair of developing unit rolls constituted by a rotating brush roll or a morton roll and a backup roll in the development processing apparatus of the present invention, and the position of the brush roll or the morton roll is the insertion position of the wedge plate It is a schematic diagram of the system regulated by. FIG. 6A is a view of the bearing portion and the rotating cam as viewed from the side of the development processing apparatus. FIG. 6B is a view of the bearing portion and the rotating cam as viewed from the direction of the insertion port of the development processing apparatus. FIG. 6C is a view of the bearing portion and the rotating cam as viewed from above the development processing apparatus. As shown in FIG. 6B, the rotation shaft 32 of the development promoting means 6 is supported by the bearing member 31. The rotating shaft 35 of the backup roll 33 that supports the plate is supported by a bearing member 34. Regarding the functions of the bearing member 31, the development promoting means 6, the rotating shaft 32, the bearing member 34, the backup roll 33, the rotating shaft 35, the convex portion 46 of the bearing member 31, the position regulating coil spring or the elastic rubber 36, Since it is the same as the above-mentioned example, in order to avoid duplication, description is abbreviate | omitted.

  As shown in FIG. 6B, the outer portion of the bearing member 31 is shaped to protrude slightly from the outer surface of the developing unit side plate 41. As shown in FIG. 6A, a wedge plate 44 described later is mounted on the lower side of the bearing member 31.

  The position of the wedge plate 44 is determined by the control device 40 of the development processing apparatus and the wedge plate control unit 45 that has received the instruction. When the control device 40 of the development processing apparatus recognizes the plate material to be processed as a lithographic printing plate, the wedge plate control unit 45 causes the development accelerating means 6 to apply a predetermined pressing pressure on the upper surface of the printing plate according to an instruction from the control device 40. The position of the wedge plate 44 is controlled so as to rotate by contact and scrape off the non-image portion of the image forming layer.

  When the control device 40 of the development processing apparatus recognizes the processed plate material as a discarded plate, the wedge plate control unit 45 controls the movement of the wedge plate 44 to the right in the case of FIG. Then, the bearing member 31 is pushed up to a position where it is retracted so that the development promoting means 6 does not come into contact with the upper surface of the discarded plate (the position indicated by the dotted line in FIG. 6A). The retreat distance necessary for the development accelerating means 6 and the discarded plate not to be in contact is sufficient for the plate surface and the development accelerating means 6 not to be in contact, specifically 2 to 5 mm. When the length is shorter than 2 mm, it is not preferable because there is a possibility of contact due to vibration or the like when the plate is conveyed. When the processing of the discarded plate is completed, the wedge plate control unit 45 controls the movement of the wedge plate 44 to the left side in the case of FIG. 6A according to an instruction from the control device 40, and returns the bearing member 31 to the original position. Then, the retraction of the development promoting means 6 is released.

  Further, the position control of the bearing member 31, the development promoting device 6 and the rotary shaft 32 by the position control of the wedge plate control unit and the wedge plate 44 which has received the instruction of the control device 40 of the development processing device is performed by pressing the development promoting device 6. Also used for pressure control. By inputting a preferable pressing pressure to the control device 40 of the development processing apparatus, it is possible to select an effective pressing pressure when processing the types of plate materials and plates having different thicknesses.

  In addition, although three types of position control methods were illustrated for description of the present invention, the position control is not limited to these. Moreover, the shape of each member in the figure used for description is not limited to the shape in the figure, and can be another shape having the same effect. In addition, this control system is equipped with one each on the bearings at both ends for one development promoting means.

  Next, a planographic printing plate processed in the development processing apparatus of the present invention will be described. Examples of the lithographic printing plate to which the development processing apparatus of the present invention can be applied include various lithographic printing plates in which an image forming layer such as a photosensitive layer and a heat-sensitive layer is provided on a support. For example, an image forming layer coated with a photosensitive or heat-sensitive composition such as a conventional positive type, a conventional negative type, a photopolymer type, a thermal positive type, or a thermal negative type is preferably used as such a lithographic printing plate. The term “conventional” as used herein refers to a conventional lithographic printing plate that performs imagewise exposure through a transparent positive image or a transparent negative image.

Hereinafter, these various image recording layers will be described.
<Conventional positive type>
A preferable example of a conventional positive photosensitive resin composition is a composition containing an o-quinonediazide compound and an alkali-soluble polymer compound. Examples of o-quinonediazide compounds include esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and phenol-formaldehyde resin or cresol-formaldehyde resin, and US Pat. No. 3,635,709. There are esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and pyrogallol acetone resin as described. Examples of the alkali-soluble polymer compound include phenol / formaldehyde resin, cresol / formaldehyde resin, phenol / cresol / formaldehyde co-condensation resin, polyhydroxystyrene, N- (4-hydroxyphenyl) methacrylamide copolymer, Examples thereof include carboxy group-containing polymers described in Japanese Patent No. 36184. Further, an acrylic resin containing a phenolic hydroxy group as described in JP-A-51-34711, an acrylic resin having a sulfonamide group described in JP-A-2-866, Various alkali-soluble polymer compounds such as urethane resins can also be used. Further, the photosensitive resin composition includes compounds such as sensitivity control agents, printing agents, dyes and the like shown in paragraph Nos. 0024 to 0027 of JP-A-7-92660 and paragraph No. 0031 of the publication. It is preferable to add a surfactant for improving the coatability.

<Conventional negative type>
Examples of conventional negative photosensitive resin compositions include those containing a diazo resin and an alkali-soluble or swellable polymer compound (binder). Examples of the diazo resin include a condensate of an aromatic diazonium salt and an active carbonyl group-containing compound such as formaldehyde. Further, for example, a condensate of p-diazophenylamines and formaldehyde and hexafluorophosphate or An organic solvent-soluble diazo resin inorganic salt that is a reaction product with tetrafluoroborate is exemplified. In particular, a high molecular weight diazo compound containing 20 mol% or more of a hexamer described in JP-A-59-78340 is preferable. Suitable binders include copolymers containing acrylic acid, methacrylic acid, crotonic acid or maleic acid as essential components, for example, 2-hydroxyethyl (meta) as described in JP-A-50-118802. ) Acrylate, (meth) acrylonitrile, multi-component copolymers of monomers such as (meth) acrylic acid, alkyl acrylate, (meth) acrylonitrile, and unsaturated carboxylic acid as described in JP-A-56-4144 Mention may be made of a multi-component copolymer comprising an acid. Furthermore, a plasticizer for imparting flexibility and abrasion resistance to the photosensitive resin composition, as shown in paragraphs 0014 to 0015 of JP-A-7-281425, It is preferable to add a compound such as a development accelerator and a surfactant for improving coating properties. As a lower layer of the above-mentioned conventional type positive type or negative type photosensitive layer, a polymer compound having a component having an acid group and a component having an onium group described in JP-A-2000-105462 is used. It is preferable to provide an intermediate layer to be contained.

<Photopolymer type>
(Photosensitive layer)
A photopolymer type photopolymerizable photosensitive composition (hereinafter referred to as “photopolymerizable composition”) is an addition-polymerizable ethylenically unsaturated bond-containing compound (hereinafter simply referred to as “ethylenically unsaturated bond-containing compound”). And a photopolymerization initiator and a polymer binder as essential components, and if necessary, various compounds such as a colorant, a plasticizer, a thermal polymerization inhibitor and the like. The ethylenically unsaturated bond-containing compound contained in the photopolymerizable composition is such that, when the photopolymerizable composition is irradiated with actinic rays, it undergoes addition polymerization by the action of the photopolymerization initiator, crosslinks and cures. It is a compound having an ethylenically unsaturated bond. The ethylenically unsaturated bond-containing compound can be arbitrarily selected from compounds having at least one terminal ethylenically unsaturated bond, preferably two or more, such as monomers, prepolymers (ie, dimers). Trimers and oligomers), mixtures thereof, and copolymers thereof. Examples of monomers include esters of unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid) and aliphatic polyhydric alcohol compounds, unsaturated carboxylic acids and aliphatic polyhydric compounds. And amides with a polyvalent amine compound. Urethane addition polymerizable compounds are also suitable.

  As the initiator contained in the photopolymerizable composition, various photopolymerization initiators or a combination system (photoinitiation system) of two or more photopolymerization initiators are appropriately selected and used depending on the wavelength of the light source used. For example, the starting system shown in paragraph numbers 0021 to 0023 of JP-A-2001-22079 is preferable. The polymer binder contained in the photopolymerizable composition not only functions as a film-forming agent for the photopolymerizable composition, but also needs to dissolve the photosensitive layer in an alkali developer. Swelling organic high molecular polymers are used. As the polymer, those shown in paragraph numbers 0036 to 0063 of the same publication are useful. In addition, it is also preferable to add the additive (for example, surfactant for improving applicability | paintability) shown by the paragraph numbers 0079-0088 of the same gazette to a photopolymerizable composition.

  It is also preferable to provide an oxygen-blocking protective layer on the photosensitive layer in order to prevent the oxygen polymerization inhibiting action. Examples of the polymer contained in the oxygen barrier protective layer include polyvinyl alcohol and its copolymer. Further, it is also preferable to provide an intermediate layer or an adhesive layer as shown in paragraphs 0124 to 0165 of JP-A-2001-228608 as the lower layer of the photopolymer type photosensitive layer.

<Thermal positive type>
(Thermosensitive layer)
The thermal positive type heat-sensitive layer contains an alkali-soluble polymer compound and a photothermal conversion substance. This alkali-soluble polymer compound includes a homopolymer containing an acidic group in the polymer, a copolymer thereof, and a mixture thereof. In particular, an acidic group such as the following (1) or (2) is included. It is preferable from the viewpoint of solubility in an alkaline developer: (1) a phenolic hydroxy group (—Ar—OH), (2) a sulfonamide group (—SO ₂ NH—R). In particular, it preferably has a phenolic hydroxy group from the viewpoint of excellent image-forming properties in exposure with an infrared laser or the like. For example, phenol-formaldehyde resin, m-cresol-formaldehyde resin, p-cresol-formaldehyde resin, m- Preferred are novolak resins such as / p-mixed cresol / formaldehyde resin and phenol / cresol (any of m-, p- and m- / p-mixed) mixed formaldehyde resin; pyrogallol / acetone resin. More specifically, the polymers shown in paragraph numbers 0023 to 0042 of JP-A No. 2001-305722 are preferably used. The photothermal conversion substance converts exposure energy into heat and can efficiently cancel the interaction of the exposed area of the heat sensitive layer. From the viewpoint of recording sensitivity, a pigment or dye having a light absorption region in the infrared region with a wavelength of 700 to 1200 nm is preferable.

  Specific examples of the dye include azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolates. A dye such as a complex (for example, a nickel thiolate complex) can be used. Among these, cyanine dyes are preferable, and examples thereof include cyanine dyes represented by general formula (I) in JP-A No. 2001-305722. In the composition of the thermal positive type, it is preferable to add a sensitivity modifier, a printing agent, a compound such as a dye similar to those described for the conventional positive type, and a surfactant for improving coating properties. Specifically, the compounds shown in paragraph numbers 0053 to 0059 of JP-A No. 2001-305722 are preferable.

  The thermal positive type heat-sensitive layer may be a single layer or may be provided as a two-layer structure as described in JP-A-11-218914.

  An undercoat layer is preferably provided between the thermal positive type heat-sensitive layer and the support. Examples of the component contained in the undercoat layer include various organic compounds shown in paragraph No. 0068 of JP-A No. 2001-305722.

<Thermal negative type>
(Thermosensitive layer)
The thermal negative-type heat-sensitive layer is a negative-type heat-sensitive layer in which an infrared laser irradiation part is cured to form an image part.

As one of such thermal negative type heat-sensitive layers, a polymerization type layer is preferably exemplified. The polymerization layer comprises (A) an infrared absorber, (B) a radical generator (radical polymerization initiator), a curing reaction caused by the generated radical (C) a radical polymerizable compound, and (D) a binder. Containing polymer.
In the polymerization layer, the infrared rays absorbed by the infrared absorber are converted into heat, and the generated heat decomposes radical polymerization initiators such as onium salts to generate radicals. The radically polymerizable compound is selected from compounds having a terminal ethylenically unsaturated bond, and a polymerization reaction is caused in a chain by the generated radicals and is cured. Examples of the infrared absorber (A) include the above-described photothermal conversion substance contained in the above-described thermal positive type heat-sensitive layer. In particular, as a specific example of the cyanine dye, paragraph number of JP-A No. 2001-133969 0017-0019 can be mentioned. (B) Examples of radical generators include onium salts. Specific examples of onium salts that can be suitably used include those described in paragraphs 0030 to 0033 of JP-A-2001-133969. Can do. (C) The radically polymerizable compound is selected from compounds having at least one terminal ethylenically unsaturated bond, preferably two or more. (D) It is preferable to use a linear organic polymer as the binder polymer, and a linear organic polymer that is soluble or swellable in water or weak alkaline water is selected. Of these, a (meth) acrylic resin having a benzyl group or an allyl group and a carboxy group in the side chain is particularly preferable because of its excellent balance of film strength, sensitivity, and developability. With respect to (C) the radical polymerizable compound and (D) the binder polymer, those described in detail in paragraph numbers 0036 to 0060 of the same publication can be used. As other additives, it is also preferable to add an additive (for example, a surfactant for improving coatability) shown in paragraph numbers 0061 to 0068 of the publication.

  In addition to the polymerization type, an acid-crosslinking type layer is preferably used as one of the thermal negative type heat-sensitive layers. The acid cross-linking layer contains (E) a compound that generates acid by light or heat (hereinafter referred to as “acid generator”) and (F) a compound that cross-links by the generated acid (hereinafter referred to as “cross-linking agent”). And (G) an alkali-soluble polymer compound that can react with a crosslinking agent in the presence of an acid. In order to efficiently use the energy of the infrared laser, (A) an infrared absorber is blended in the acid crosslinking layer. Examples of the acid generator (E) include compounds capable of generating an acid upon thermal decomposition, such as a photoinitiator for photopolymerization, a photochromic agent for dyes, and an acid generator used for a microresist. . (F) The crosslinking agent includes (i) an aromatic compound substituted with a hydroxymethyl group or an alkoxymethyl group, (ii) a compound having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group, Or (iii) an epoxy compound is mentioned. (G) Examples of the alkali-soluble polymer compound include novolak resins and polymers having a hydroxyaryl group in the side chain.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, the present invention is not limited to these Examples from the effect.

(Example)
The development processing apparatus in this embodiment will be described below with reference to FIG. FIG. 1 is a schematic sectional view showing an example of a development processing apparatus used in the present invention. In the bearing portion of the development accelerating means 6 of the developing device used in this embodiment, the position of the development accelerating means shown in FIG. A system and a control mechanism were installed. The version type input means is an information input method by an operator. The received plate material type information is appropriately processed by a control mechanism inside the development processing apparatus, and in the case of a lithographic printing plate, development processing using a development accelerating means, water washing processing, gumming processing, and drying processing are sequentially performed. In the case of a discarded plate, the development accelerating means in the developing tank is evacuated, the development process without using the development accelerating means, the washing process, the gumming process, and the drying process are sequentially performed. Perform the recovery procedure.

  When the discarded plate is inserted into the development processing apparatus, the plate is conveyed to the development processing unit and immersed in the developer maintained at a liquid temperature of 30 degrees. The development promoting means 6 is retracted above the plate surface in order to avoid contact with the plate surface based on the plate type information obtained in advance. The undercoat layer, dust, and dirt on the upper surface of the plate are quickly dissolved or removed by being immersed in the developer. The development promoting device 6 retracted upward returns to the original position after the plate drying process described later.

  Next, the processed plate is transported to the water washing processing section, which is the next step, while excessive developer on the plate surface is squeezed by the transport rolls 10 and 11 that also function as a developer squeezing function. In the washing unit, the plate surface is washed with washing water discharged from the shower pipe 14 while being conveyed by the conveyance rolls 12 and 13. Further, the excess roll water on the plate surface is squeezed by the transport rolls 16 and 17 that also serve as a squeeze water squeezing function, and the squeezed water is transported to the gum processing section as the next step.

  In the gum processing unit, the gum solution discharged from the shower pipe 20 is applied to the entire plate surface while being transported by the transport rolls 18 and 19. This neutralizes the alkali component by oxidizing the plate surface and desensitizes the non-image area. Further, the excess gum solution on the plate surface is squeezed by the gum part conveying and squeezing rolls 22 and 23 that also serve as a squeezing function of the gum solution, and is conveyed to the drying processing unit, which is the next step not shown in the drawing. In the drying processing section, the entire printing plate is dried, and a protective film is formed on the printing plate by the gum solution component.

  The following experiment was performed using a planographic printing plate PD-News manufactured by Mitsubishi Paper Industries, Ltd. and a discarded plate GA plate manufactured by Tokyo Ohka Kogyo Co., Ltd. as a discarded plate.

For the lithographic printing plate PD-News, using an external drum plate setter (PT-R4000 manufactured by Dainippon Screen Mfg. Co., Ltd.) equipped with an 830 nm semiconductor laser, the drum rotation speed is 1000 rpm and the laser irradiation energy is 50 mJ / cm ^2. Then, the exposure process was performed, and then the development process was performed by the automatic developing machine.

  The developer PD-NewsDV manufactured by Mitsubishi Paper Industries Co., Ltd. was used as the developer at a dilution ratio of 1: 3 with water. Washing water used normal tap water. For the gum solution, a gum solution PD-NewsGum manufactured by Mitsubishi Paper Industries, Ltd. was used at a dilution ratio of 1: 1 with water.

  The processing ratio of the planographic printing plate PD-News and the discard plate GA plate was processed with the printing plate 3: discard plate 1, which is a ratio often used in a general newspaper factory.

  As a development promoting means, a Morton sleeve “Aquanaut” manufactured by Choji Co., Ltd. was used, and the state of wear was confirmed every 1000 sheets processed. The results are shown in Table 1.

(Comparative example)
Except for not providing a retracting mechanism for the development accelerating device, a development processing device having the same structure as in the above example was used, and the wear state of the development accelerating means was confirmed every 1000 sheets processed. The results are shown in Table 1.

  In the comparative example that does not have a retracting mechanism for the development accelerating means, the wear of the development accelerating rough means cannot be put into practical use after processing 15,000 lithographic printing plates and 5000 discarded plates. It became difficult to uniformly dissolve the photosensitive layer in the image area. In the embodiment having the retraction mechanism of the Molton roll, the photosensitive layer in the non-image area of the lithographic printing plate is uniformly dissolved until 30,000 lithographic printing plates and 10,000 discarded plates are processed. Life expectancy was confirmed.

DESCRIPTION OF SYMBOLS 1 Conveyance roll 2 Conveyance roll 3 In-liquid conveyance roll 4 In-liquid conveyance roll 5 Circulation shower pipe 6 Development promotion means 7 Backup roll 8 In-liquid conveyance roll 9 In-liquid conveyance roll 10 Conveyance roll 11 Conveyance roll 12 Conveyance roll 13 Conveyance roll 14 Shower pipe 15 Backup roll 16 Transport roll 17 Transport roll 18 Transport roll 19 Transport roll 20 Shower pipe 21 Backup roll 22 Gum part transport and squeeze roll 23 Gum part transport and squeeze roll 31 Bearing member 32 Rotating shaft 33 Backup roll 34 Backup roll Bearing member 35 Rotating shaft 36 Coil spring or elastic rubber 37 for regulating the position of development promoting means 37 Cam plate 38 Rotating shaft 39 Motor 40 Control device 41 Development processing unit side plate 42 Piston 43 Cylinder 44 Wedge plate 45 Wedge Controller 46 protrusions 100 pass route

Claims (1)

  Means for receiving information on whether the plate material to be processed is a planographic printing plate or a discarded plate; and means for retracting the development promoting means so that the development promoting means in the developing tank does not contact the plate surface of the discarded plate; A lithographic printing plate development processing apparatus comprising:

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