JP4980821B2 - Planographic printing plate processing equipment - Google Patents

Description

  The present invention relates to a processing apparatus for a lithographic printing plate, and in particular, is used as a so-called computer-to-plate (CTP) plate capable of directly forming an image by irradiating infrared rays from a solid laser or semiconductor laser based on a digital signal. The present invention relates to an infrared sensitive or heat sensitive lithographic printing plate development processing apparatus.

  In recent years, with the advance of computer image processing technology, a method of directly writing an image on a photosensitive layer by light irradiation corresponding to a digital signal has been developed. A computer-to-plate (CTP) system that uses this method for a photosensitive lithographic printing plate and directly forms an image on the photosensitive lithographic printing plate without outputting to a silver salt mask film has attracted attention. . A CTP system that uses a high-power laser having the maximum intensity in the near-infrared or infrared region as a light source for light irradiation can obtain a high-resolution image with a short exposure, and the photosensitive lithographic printing plate used in the system is bright. It has the advantage that it can be handled in a room. In particular, solid lasers and semiconductor lasers that emit infrared light having a wavelength of 760 nm to 1200 nm have become readily available as high-power and small-sized lasers.

Such a photosensitive lithographic printing plate is imagewise exposed by the laser and then subjected to a development treatment to form a lithographic printing plate. As an apparatus for performing the developing process, for example, an automatic developing apparatus including a developing unit and a water washing unit as described in JP-A-2006-58735 is widely used. In the developing unit, the exposed lithographic printing plate is immersed in the developer stored in the developing tank, and the photosensitive layer of the non-image part on the plate is dissolved and removed in the developer. The lithographic printing plate developed in this manner is carried out of the developing tank, and the developer on the plate surface is squeezed by a squeezing roller comprising a pair of rollers having a smooth surface. Next, the lithographic printing plate from which the developing solution has been squeezed is conveyed to a water washing section, and the developing solution remaining on the surface is completely removed by the washing water.
JP 2006-58735 A

  However, when an infrared sensitive or heat sensitive (so-called thermal type) lithographic printing plate is processed by the automatic developing apparatus as described above, if the activity of the developing solution decreases due to liquid fatigue, The portion may receive ink, resulting in printing stains, or the ink receptivity of a part of the image portion may be lowered, resulting in an image defect due to ink imperfection. These printing stains and image defects may be caused by adhesion of undeveloped substances such as resin derived from the photosensitive layer of the lithographic printing plate precursor remaining in the developing solution to the non-image area or image area. It is thought to be the cause.

  An object of the present invention is to provide a processing apparatus capable of forming a good image without causing adhesion of an undeveloped substance even with an infrared sensitive or heat sensitive lithographic printing plate.

The present invention is a lithographic printing plate processing apparatus comprising a developing unit for developing a lithographic printing plate, and a cleaning unit for cleaning the developed lithographic printing plate carried out from the developing unit,
A pair of squeezing rollers having a smooth surface for removing the developer on the developed lithographic printing plate at the outlet of the developing unit; and
An additional developer supplying means for supplying an additional developer to the surface of the developed lithographic printing plate is provided between the outlet of the developing unit and the inlet of the cleaning unit.

  The additional developer supply means preferably includes a spray or dripping device for the additional developer.

  The additional developer supply means preferably supplies the additional developer to the surface of the squeezing roller on the cleaning unit side.

  The additional developer supply means includes a first additional developer holding roller facing one of the squeezing rollers, and additional development is performed between the squeezing roller and the first additional developer holding roller. It is preferable that the liquid is stored.

  It is preferable that at least a part of the surface of the first additional developer holding roller is roughened.

  In the present invention, the entrance of the cleaning section is provided with a pair of transport rollers for transporting the developed lithographic printing plate into the cleaning section, and the additional developer supply means is provided on the developing section side of the transport roller. It is preferable to supply additional developer to the surface.

  The additional developer supply means includes a second additional developer holding roller facing one of the conveying rollers, and additional development is performed between the conveying roller and the second additional developer holding roller. It is preferable that the liquid is stored.

  It is preferable that at least a part of the surface of the second additional developer holding roller is roughened.

  In the present invention, the additional developer supply means may supply the additional developer directly to the surface of the lithographic printing plate between the outlet of the developing unit and the inlet of the cleaning unit.

  In the lithographic printing plate processing apparatus of the present invention, since the generation of development residual substances is improved, printing stains in the non-image area and image defects in the image area may occur even in an infrared sensitive or heat sensitive lithographic printing plate. And good image formation can be performed.

  When supplying the additional developer to the surface of the squeezing roller on the washing unit side, a small amount of additional developer can be reliably supplied to the developed lithographic printing plate. Here, “developed lithographic printing plate” means a lithographic printing plate that has undergone development and has undergone development when it has passed through the squeeze roller, and the non-image portion of the photosensitive layer of the lithographic printing plate is removed. Has been. Therefore, a lithographic printing plate that has undergone development processing in the developing unit does not belong to the range of “developed lithographic printing plate”.

  In the processing apparatus of the present invention, the additional developer supply means includes a first additional developer holding roller facing one of the squeezing rollers, and the squeezing roller and the first additional developer holding roller When the additional developer is stored in the meantime, the additional developer can be more uniformly applied to the direction perpendicular to the transport direction of the developed lithographic printing plate.

  When at least a part of the surface of the first additional developer holding roller is roughened, the first additional developer holding roller can be brought into contact with the squeezing roller. An independent drive mechanism for the developer holding roller is not required, and the amount of additional developer stored can be controlled more easily.

  The processing apparatus of the present invention includes a pair of transport rollers for transporting the developed lithographic printing plate into the cleaning section at the entrance of the cleaning section, and an additional developer supply means is provided on the surface of the transport roller on the developing section side. When supplying the additional developer, it is possible to suppress the addition of the additional developer to the cleaning unit.

  In the processing apparatus of the present invention, the additional developer supply means includes a second additional developer holding roller facing one of the transport rollers, and the transport roller and the second additional developer holding roller When the additional developer is stored in the meantime, the additional developer can be more uniformly applied to the direction perpendicular to the transport direction of the developed lithographic printing plate.

  When at least a part of the surface of the second additional developer holding roller is roughened, the second additional developer holding roller can be brought into contact with the transport roller. An independent drive mechanism for the developer holding roller is not required, and the amount of additional developer stored can be controlled more easily.

  In the processing apparatus of the present invention, when the additional developer supply means supplies the additional developer directly to the surface of the planographic printing plate between the outlet of the developing unit and the inlet of the cleaning unit, the additional developer is added on the planographic printing plate. The uneven supply of the developer can be further suppressed.

  The lithographic printing plate processing apparatus of the present invention includes at least a developing unit that performs development processing of an exposed lithographic printing plate and a cleaning unit that cleans the developed lithographic printing plate carried out from the developing unit. The cleaning unit may be followed by a finishing unit for applying a gum solution and a drying unit for drying. The lithographic printing plate processing apparatus of the present invention is suitably applied to processing of a lithographic printing plate that has been imagewise exposed.

  Hereinafter, the present invention will be specifically described with reference to the drawings. FIG. 1 is a schematic sectional view showing an automatic developing apparatus 1 as one embodiment of the planographic printing plate processing apparatus of the present invention.

  The automatic developing device 1 cleans the developing unit 3 that develops the lithographic printing plate 2 conveyed along the conveying path indicated by the one-dot chain line in FIG. 1 with a developer, and the surface of the developed lithographic printing plate 2 A cleaning unit 4 for performing the coating process, a finishing unit 5 for applying a gum solution for protecting the plate surface to the lithographic printing plate 2 after cleaning, and a desensitization treatment, and a drying unit 6 for drying the lithographic printing plate 2. That is, in the automatic developing device 1 shown in FIG. 1, the developing unit 3, the cleaning unit 4, the finishing unit 5, and the drying unit 6 are sequentially arranged in the transport direction of the planographic printing plate 2 (left side in FIG. 1). Has been.

  In the automatic developing apparatus 1 shown in FIG. 1, a single developing tank 31 is disposed in the developing unit 3, and the periphery of the developing tank 31 is covered with a panel 32. A slit-like insertion port 33 for inserting the planographic printing plate 2 is formed at the end of the panel 32, and the planographic printing plate 2 is introduced into the developing unit 3 from the insertion port 33. On the other hand, a pair of transport rollers 34 is disposed at a position adjacent to the insertion port 33. Accordingly, the lithographic printing plate 2 introduced into the developing unit 3 from the insertion port 33 is sent between the conveyance rollers 34.

  The conveyance roller 34 is rotationally driven by a drive source (not shown), and conveys the planographic printing plate 2 obliquely downward from the insertion port 33, that is, toward the developing tank 31. In the automatic developing apparatus 1 shown in FIG. 1, a lithographic printing plate 2 of a type in which a photosensitive layer (thermal surface) is formed on one side is inserted from an insertion port 33 with the photosensitive layer (thermal surface) facing upward. The The number of developing tanks is not particularly limited, and the developing unit 3 may include two or more developing tanks 31. However, in order to reduce the size of the processing apparatus and reduce the processing cost, FIG. As shown, the developing unit 3 preferably includes a single developing tank 31.

  The developing tank 31 has a shape in which the center of the bottom portion protrudes downward, and stores a developer for developing the planographic printing plate 2. A lid member 35 is disposed on the surface of the developing solution in the developing tank 31 to prevent the developing solution from being deteriorated by carbon dioxide in the air. The developing tank 31 is provided with a developing solution circulation filtration means and a developing solution supply / discharge means (not shown). The developing solution is circulated and used, and a new developing replenisher is supplied and the developing activity is lowered. The old developer can be discharged.

  In the developing tank 31, two pairs of a conveying roller 36 and a conveying roller 37 are arranged at the center thereof, and further, squeezing rollers 38a and 38b are arranged at the outlet of the developing unit 3. The squeezing rollers 38a and 38b both have a smooth surface. Therefore, when the planographic printing plate 2 is held between the squeezing rollers 38a and 38b, the surface of the planographic printing plate 2 can receive a uniform pressure. Further, in the developing tank 31, illustration is omitted between the conveyance roller 34 and the conveyance roller 36, between the conveyance roller 36 and the conveyance roller 37, and between the conveyance roller 37 and the squeezing rollers 38a and 38b. A guide plate or the like is disposed, and in combination with the conveying roller 36, the conveying roller 37, and the squeezing rollers 38a and 38b, an abbreviation for conveying the lithographic printing plate 2 while being immersed in the developer in the developing tank 31. A U-shaped conveyance path (one-dot chain line) is formed.

  In the mode shown in FIG. 1, a brush roller 39 is disposed at a position below the level of the developer in the developing tank 31 and between the transport roller 37 and the squeezing rollers 38a and 38b. The brush roller 39 is attached between the transport roller 37 and the squeezing roller 38b so as to face the upper surface side of the planographic printing plate 2 transported along the transport path. The brush roller 39 contacts the upper surface of the lithographic printing plate 2 while rotating in a predetermined direction and number of rotations, thereby brushing the photosensitive layer (heat-sensitive surface) on the upper surface side of the lithographic printing plate 2 and Promotes the removal of the photosensitive layer (thermal surface). Although any roller having a brushing action can be used as the brush roller 39, a Molton roller is preferable.

  Therefore, the exposed lithographic printing plate 2 having a latent image introduced from the insertion port 33 is drawn into the developer by the transport roller 34 and is held in the developer by the transport roller 36 and the transport roller 37. The photosensitive layer (heat-sensitive surface) in the non-image area is removed by undergoing development processing along the conveyance path. The developed lithographic printing plate 2 is conveyed obliquely upward by the squeezing rollers 38a and 38b that also function as conveying rollers. At this time, the upper surface side of the lithographic printing plate 2 is brushed by the brush roller 39, and the non-image portion The photosensitive layer (heat sensitive surface) is completely removed. The lithographic printing plate developed in this manner is guided out of the developer in the developing tank 31 along the transport path. In order to improve developability, a spray pipe for ejecting the developer in the developer tank 31 toward the planographic printing plate 2 by the action of a pump (not shown) may be provided in the developer tank 31. preferable.

  In this way, the lithographic printing plate 2 from which the photosensitive layer (heat-sensitive surface) of the non-image part has been removed by being immersed in the developer in the developing tank 31 is discharged out of the developing part 3 by the squeezing rollers 38a and 38b, and the washing part 4 It is conveyed to. The developer on the surface of the lithographic printing plate 2 is squeezed and removed when the lithographic printing plate 2 passes through the gap between the squeezing rollers 38a and 38b.

  A cleaning tank 41 is disposed in the cleaning unit 4, and the periphery of the cleaning tank 41 is covered with a panel 42. Conveying rollers 43 a and 43 b are provided at the entrance of the cleaning unit 4, and the planographic printing plate 2 transported from the developing unit 3 is nipped and introduced into the cleaning unit 4. On the other hand, a pair of transport rollers 44 are provided at the outlet of the cleaning unit 4, and the cleaned lithographic printing plate 2 is carried out of the cleaning unit 4. Accordingly, in the cleaning unit 4, the planographic printing plate 2 is transported substantially horizontally by the transport rollers 43 a and 43 b and the transport roller 44.

  Above the cleaning tank 41, a spray pipe 45 for discharging the cleaning agent is provided. The spray pipe 45 is arranged such that the axial direction is the width direction of the transport rollers 43a and 43b (direction orthogonal to the transport direction of the planographic printing plate 2), and a plurality of discharge holes (not shown) facing the planographic printing plate 2 ) Are formed along the axial direction.

  Water (cleaning water) is stored in the cleaning tank 41 as a cleaning agent. In the automatic developing device 1 shown in FIG. 1, the cleaning water in the cleaning tank 41 is supplied to the spray pipe 45 by a pump (not shown). The The cleaning water supplied to the spray pipe 45 is discharged from the discharge port, reaches the surface of the planographic printing plate 2, and is then collected again in the cleaning tank 41. In order to prevent the washing water from directly hitting the planographic printing plate 2, the discharge port is preferably directed to either the transport roller 43a or 43b, preferably to the transport roller 43b, as shown in FIG. The cleaning tank 41 is provided with cleaning water circulation filtering means and cleaning water supply / discharge means (not shown), and it is possible to circulate and use the cleaning water, supply new cleaning water, and discharge old cleaning water. Has been.

  In the embodiment shown in FIG. 1, a draining roller 46 is disposed on the transport roller 43b so as to contact the outer peripheral surface of the roller, and along with the rotation of the transport roller 43b, the cleaning water flows along the outer peripheral surface of the developing unit 3. The developing solution in the developing tank 31 is diluted to prevent the development activity of the developing solution from fluctuating.

  Note that preservatives and bactericides may be added to the cleaning water in the cleaning tank 41 in order to suppress the growth of scales and molds. Further, a brush roll may be provided between the transport rolls 43a and 43b and the transport roller 44 as necessary.

  Therefore, the surface of the developed lithographic printing plate 2 introduced into the cleaning unit 4 by the transport rollers 43a and 43b disposed at the entrance of the cleaning unit 4 is cleaned by the cleaning water discharged from the spray pipe 45. Then, the developer is removed. The used cleaning water is stored at the bottom of the cleaning tank 41, and after being circulated, is appropriately discharged. Then, the washed lithographic printing plate 2 is squeezed out of the cleaning water on the surface thereof by the transport roller 44 disposed at the outlet of the cleaning section 4 and is transported to the next finishing section 5.

  The finishing section 5 is provided with a finishing treatment tank 51 for storing the gum solution, and the periphery of the finishing tank 51 is covered with a panel 52 integrated with the panel 42. A pair of transport rollers 53 are provided in the finishing unit 5 to transport the planographic printing plate 2 substantially horizontally.

  Gum liquid is supplied from the finishing tank 51 by the gum liquid replenishing means 56 and 57 to the rollers on both sides of the conveying roller 53 in the finishing unit 5. In the embodiment shown in FIG. 1, an upper spray pipe 56 that directly supplies the gum solution to the surface of the lithographic printing plate 2 and a lower spray pipe 57 that directly supplies the gum solution to the back surface of the lithographic printing plate 2 are provided. It is possible to perform a desensitization treatment on the front and back surfaces of the planographic printing plate 2. The upper spray pipe 56 and the lower spray pipe 57 are arranged such that the axial direction is the width direction of the transport roller 53 (a direction orthogonal to the transport direction of the planographic printing plate 2), and a plurality of discharges facing the planographic printing plate 2 A hole (not shown) is formed along the axial direction. Thereby, the gum solution is spray-coated on both surfaces of the lithographic printing plate 2 to perform the desensitization treatment. The finishing tank 51 is provided with a gum solution circulation filtering unit and a gum solution supply / discharge unit (not shown), and the circulation and use of the gum solution, the supply of a new gum solution, and the discharge of the old gum solution are performed. It is possible.

  On the other hand, the finishing unit 5 can be provided with a roller cleaning device. In the example shown in FIG. 1, a roller 55 is disposed close to the upper conveying roller 53, and a cleaning liquid (water) supply unit 54 is disposed above the roller 55 and the roller 55 and the supply unit 54. A roller cleaning device is configured. In this case, the cleaning liquid (water) is temporarily stored in the gap between the transport roller 53 and the roller 55, spreads in the width direction of the transport roller 53, and then flows down to clean the roller.

  The planographic printing plate 2 that has been subjected to the desensitization process in the finishing unit 5 is then conveyed to the drying unit 6 by the conveyance roller 53. At this time, the gum solution on the front and back surfaces of the lithographic printing plate 2 is squeezed out by the gap between the conveying rollers 53 to be an appropriate amount.

  The drying unit 6 is covered with a cover 61, and inside thereof, drying ducts 64 and 65 are disposed on the upper and lower sides of the transport path of the planographic printing plate 2 formed by the guide rollers 62 and 63. Dry air controlled to a predetermined temperature is blown from the drying ducts 64 and 65 onto the front and back surfaces of the planographic printing plate 2. Thereby, the gum solution on the front and back surfaces of the lithographic printing plate 2 is dried, and a protective film is formed.

  A slit-like discharge port 66 for discharging the planographic printing plate 2 is formed at the end of the cover 61, and a pair of dry molton rollers 67 are provided in the vicinity of the discharge port 66. Accordingly, the planographic printing plate 2 on which the protective film is formed is discharged from the discharge port 66 to the outside of the drying unit 6 by the drying Molton roller 67.

  As described above, in the automatic developing apparatus 1 shown in FIG. 1, the lithographic printing plate 2 as a plate material is obtained through the processing in the developing unit 3, the cleaning unit 4, the finishing unit 5, and the drying unit 6. In the automatic developing apparatus 1, not only the lithographic printing plate 2 having a photosensitive layer (thermal surface) formed on one side of the substrate, but also a lithographic printing plate having a photosensitive layer (thermal surface) formed on both sides of the substrate. It is also possible to process. In this case, it is preferable to install the brush roller 39 in the developing tank 31 below the transport path of the planographic printing plate 2.

  FIG. 2 is an enlarged conceptual diagram of a portion surrounded by a dotted line in FIG. A dotted line X in FIG. 2 represents a straight line passing through the centers of the squeeze rollers 38a and 38b and perpendicular to the transport path (dashed line) of the planographic printing plate. Similarly, the dotted line Y in FIG. It represents a straight line passing through the center and perpendicular to the transport path (dashed line) of the planographic printing plate. Therefore, the left side of the dotted line X represents the developing unit 3, and the right side of the dotted line Y represents the cleaning unit 4.

  In the planographic printing plate processing apparatus of the present invention, a developer (hereinafter referred to as “additional developer”) is added to the surface of the developed planographic printing plate 2 between the outlet of the developing unit 3 and the inlet of the cleaning unit 4. Supplied. The additional developer is not used for so-called “development” for removing the photosensitive layer (heat-sensitive surface) in the non-image area of a normal lithographic printing plate. This is to remove the substance adhering to the area to prevent the non-image area from being stained and to improve the water repellency of the image area.

As the additional developing solution, any one having the same or different composition as the developing solution in the developing tank 31 may be used. However, in terms of the simplicity of the apparatus configuration of the automatic developing device 1, the developing in the developing tank 31 is performed. It is preferable to use a liquid. When the developer in the developing tank 31 is used as the additional developer, the additional developer is not used for removing the non-image portion of the planographic printing plate. The amount of the developer applied to the surface of the lithographic printing plate 2 can be considerably reduced. Therefore, when the concentration of the additional developer is the same as that in the developer tank 31, the supply amount of the additional developer is, for example, 10 to 100 ml / m ^{2 based} on the surface area of the planographic printing plate ^2. More preferably, about 10-50 ml / m < ² > is preferable.

  Means for supplying additional developer to the surface of the planographic printing plate 2 between the outlet of the developing unit 3 and the inlet of the cleaning unit 4 (hereinafter referred to as “additional developer supplying unit”) is not particularly limited. For example, a spray or dripping device such as a spray pipe widely used in the technical field can be used as appropriate.

  The timing of supplying the additional developer may be continuous or intermittent. In particular, during the processing of the lithographic printing plate 2, the supply of the replenishment developer to the developer tank 31, or the developer in the developer tank 31. It is preferable to supply the additional developer continuously or intermittently during the liquid temperature adjustment.

The additional developer supplied to the surface of the lithographic printing plate 2 by the additional developer supply means is collected by a recovery tank (not shown), and is supplied again to the additional developer supply means by means of a circulation pump and reused. However, when the developer in the developing tank 31 is used as an additional developer, the additional developer travels along the surface of the squeeze rolls 38a and 38b or the planographic printing plate 2 to develop the developing unit 3. It is preferably guided to the developing tank 31. In this case, additional developer may be dripped from the end of the lithographic printing plate 2 to the outside of the developing unit 3, but the amount is typically about 2 ml / m ² , and the amount of loss of the additional developer. Is negligible.

  In order to reliably supply a small amount of additional developer to the surface of the developed lithographic printing plate 2 discharged from the developing unit 3, the additional developer supply means is provided on the surface of the squeeze rollers 38a and 38b on the cleaning unit 4 side. It is preferable to supply the additional developer, and in particular, it is preferable to supply the additional developer to the surface of the squeeze roller 38a at the position shown in FIG. Here, “the cleaning unit 4 side of the squeezing rollers 38a and 38b” means the right side of the dotted line X in FIG.

  The additional developer supply means can also supply the additional developer directly to the surface of the lithographic printing plate at an arbitrary position between the outlet of the developing unit 3 and the inlet of the cleaning unit 4. In this case, for example, a predetermined amount of additional developer may be sprayed from the spray pipe or the like (not shown) on the surface of the planographic printing plate 2 at the position shown in FIG. For example, if the supply unevenness occurs on the surface of the lithographic printing plate 2 when the additional developer is supplied at the position shown in FIG. 2A, the additional developer is supplied at the position shown in FIG. 2B. The supply unevenness can be eliminated by supplying directly to the surface of 2.

  Further, the additional developer may be supplied onto the planographic printing plate 2 at the entrance of the cleaning unit 4. However, in order to prevent the additional developer from entering the cleaning unit 4 and reducing the cleaning efficiency of the planographic printing plate 2, the additional developer supply means is provided on the developing unit 3 side of the transport rollers 43a and 43b. It is preferable to supply the additional developer to the surface, and it is particularly preferable to supply the additional developer to the surface of the transport roller 43a at the position shown in FIG. Here, “the developing roller 3 side of the transport rollers 43a and 43b” means the left side of the dotted line Y in FIG.

  That is, in the present invention, the additional developer can be supplied to the surface of the planographic printing plate 2 at an arbitrary position between the dotted line X and the dotted line Y shown in FIG. Therefore, in the example shown in FIG. 2, the additional developer supply means can be disposed at any position of (a) to (c), and any position selected from (a) to (c). As well as (a) and (b), (b) and (c), (a) and (c) two places, or (a) and (b) and (c) three additional development A plurality of liquid supply means can be provided. However, in order to avoid mixing the developing solution into the cleaning unit 4 as much as possible, in the example of FIG. 2, the position (b) or (a) is preferable to (c), and (a) is more preferable than (b). The position is preferred.

  FIG. 3 is a schematic sectional view showing an embodiment of the additional developer supply means used in the present invention. In the embodiment shown in FIG. 3, the additional developer is supplied to the surface of the squeeze roller 38b at the position shown in FIG. 2 (a), and is opposed to the surface of the spray pipe 8 and the squeeze roller 38b as additional developer supply means. The first additional developer holding roller 7 is provided.

  In the embodiment shown in FIG. 3, the spray pipe 8 is constituted by a hollow pipe having a rectangular cross section, and the axial direction thereof is the width direction of the squeeze roller 38b (the direction orthogonal to the conveying direction of the planographic printing plate 2). A plurality of ejection holes that are disposed and face the surface of the squeeze roller 38b are formed along the axial direction. In addition, the cross-sectional shape of the spray pipe 8 is arbitrary, and may be circular, for example.

  In the embodiment shown in FIG. 3, the first additional developer holding roller 7 is disposed at a position facing the squeezing roller 38b with a predetermined gap, and the additional developer from the spray pipe 8 is supplied to the squeezing roller 38b. And the first additional developer holding roller 7 are supplied toward the gap. Therefore, the additional developer supplied from the spray pipe 8 can be stored between the squeezing roller 38b and the first additional developer holding roller 7 by adjusting the gap to a predetermined narrowness. The amount of additional developer stored can be appropriately adjusted depending on the size of the squeezing rollers 38a and 38b, the size of the lithographic printing plate 2, and the like, and typically about 50 to 100 ml. As a result, the additional developer can be spread evenly in the width direction of the squeeze roller 38b, and the additional developer can be more uniformly supplied to the direction perpendicular to the transport direction of the planographic printing plate 2 via the squeeze roller 38b. can do.

  In the embodiment shown in FIG. 3, the first additional developer holding roller 7 can be rotated by a drive mechanism (not shown). The rotation direction and the number of rotations can be appropriately set as necessary. In order to store the additional developer between the squeeze roller 38b and the first additional developer holding roller 7, the first developer The rotation direction of the additional developer holding roller 7 is preferably opposite to the rotation direction of the aperture roller 38b.

  At least a part of the surface of the first additional developer holding roller 7 may be roughened. The term “roughening” here includes any treatment that makes the surface of the first additional developer holding roller 7 non-smooth, and specifically, other than forming fine irregularities. Further, embossing is performed on the roller surface, at least one linear or curved groove is formed, and at least one spiral groove is formed. Since the roughened first additional developer holding roller 7 can be brought into contact with the squeezing roller 38b, it is not necessary to adjust the narrowness of the gap, and it is easier to control the amount of additional developer stored. It is. Further, an independent rotational drive mechanism for the first additional developer holding roller 7 is not required.

  3 is based on the assumption that the additional developer is supplied to the surface of the squeeze roller 38b at the position (a) shown in FIG. 2, but the additional developer is supplied at the position (c) shown in FIG. When supplying to the surface of the conveyance roller 43b, a combination of a spray pipe and a second additional developer holding roller as shown in FIG. 3 may be provided in the vicinity of the conveyance roller 43b as additional developer supply means. Good. Also in this case, the surface of the second additional developer holding roller may be roughened.

  When additional developer is supplied at two locations (a) and (c) shown in FIG. 2, the spray pipe and the first and second additional portions are provided near the surfaces of both the squeeze roller 38b and the transport roller 43b. Two combinations of developer holding rollers may be provided as additional developer supply means. Also in this case, the surface of the additional developer holding roller may be roughened.

  In the present invention, a small amount of developer is intentionally supplied to the surface of the planographic printing plate 2 that has been subjected to the development process between the outlet of the developing unit 3 and the inlet of the cleaning unit 4 as described above. Further, it is possible to suppress printing stains in the non-image area and a decrease in water repellency of the image area due to adhesion of the development residual material of the planographic printing plate 2. Therefore, the automatic developing apparatus 1 of the present invention can form a good image without causing printing stains in the non-image area and image defects in the image area, even if it is an infrared sensitive or heat sensitive planographic printing plate. It can be carried out.

  However, the lithographic printing plate 2 needs to be subjected to a uniform pressure by the squeezing rolls 38a and 38b before being supplied with the small amount of additional developer. Even if the resin derived from the photosensitive layer of the planographic printing plate 2 changes to a hydrophilic salt and adheres to an image area or a non-image area by receiving a uniform pressure, the adhering matter is compressed and a small amount of It is considered that the additional developer can satisfactorily remove the developer. Therefore, if the lithographic printing plate 2 is subjected to non-uniform pressure when exiting the developing section 3, a partial difference occurs in the physical state of the deposit on the photosensitive layer of the lithographic printing plate 2 and the pressure is received. An image defect may occur in a portion where the pressure is low or the pressure is low. Therefore, the surfaces of the squeeze rolls 38a and 38b need to be smooth. That is, in the planographic printing plate processing apparatus of the present invention, the surfaces of the squeeze rolls 38a and 38b are not roughened.

  The lithographic printing plate processing apparatus of the present invention can be used for processing any lithographic printing plate. In particular, the image forming process of an infrared sensitive or heat sensitive lithographic printing plate having a maximum absorption wavelength in the region of 760 nm to 1200 nm. Can be suitably used. Specifically, the lithographic printing plate processing apparatus of the present invention can be suitably used for the conventional positive type, conventional negative type, thermal positive type, thermal negative type, and photopolymer type exemplified below. The present invention is preferably used for image forming processing of a type of photosensitive lithographic printing plate.

(Conventional positive type)
The conventional positive type photosensitive layer is preferably formed from a photosensitive 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. Examples include 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 JP-A-7-36184. Further, acrylic resins containing phenolic hydroxy groups as described in JP-A-51-34711, acrylic resins having sulfonamide groups as described in JP-A-2-866, and urethane Various alkali-soluble polymer compounds such as resins can also be used.

  Further, conventional positive type photosensitive layers are shown in compounds such as sensitivity modifiers, printing agents, dyes and the like described in JP-A-7-92660 [0024] to [0027] and in the same publication [0031]. It is preferable to add a surfactant for improving the coatability.

(Conventional negative type)
The conventional negative type photosensitive layer is preferably formed from a photosensitive composition 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 (metathelium) 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 as described in JP-A-56-4144 Mention may be made of multi-component copolymers composed of carboxylic acids.

  Furthermore, the conventional negative type photosensitive layer is provided with the flexibility and abrasion resistance of the printing agent, dye, and coating film disclosed in JP-A-7-281425 [0014] to [0015]. It is preferable to add a plasticizer, a compound such as a development accelerator, and a surfactant for improving coating properties.

(Thermal positive type)
The thermal positive type photosensitive layer preferably contains an alkali-soluble polymer compound and a photothermal conversion substance. The alkali-soluble polymer compound includes homopolymers containing an acidic group in the polymer, copolymers thereof, and mixtures thereof. In particular, acidic groups such as the following (1) and (2) are included. It is preferable in terms of solubility in an alkali developer:
(1) phenolic hydroxy group (-Ar-OH: Ar is an arylene group),
(2) sulfonamide group _(-SO 2 NH-R: R is a hydrogen atom or an alkyl group).

  In particular, it is preferable to have a phenolic hydroxy group from the viewpoint of excellent image forming property upon exposure with an infrared laser or the like, for example, phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m− / p−. Preferable examples include mixed cresol formaldehyde resins, phenol / cresol (any of m-, p- and m- / p-mixed) mixed formaldehyde resins, etc .; pyrogallol acetone resins. In more detail, the polymer shown by [0023]-[0042] of Unexamined-Japanese-Patent No. 2001-305722 and the modified phenol resin of WO02 / 053627 are used preferably.

  As the photothermal conversion substance, it is possible to efficiently release the interaction of the exposed area of the photosensitive layer by converting the exposure energy into heat. 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. As a dye. Specifically, 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 thiolate complexes (for example, A dye such as 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 thermal positive type composition, it is preferable to add a sensitivity modifier, a bake-out agent, a compound such as a dye, and a surfactant for improving the coating property similar to those described for the conventional positive type. Specifically, the compounds shown in [0053] to [0059] of JP-A No. 2001-305722 are preferable.

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

(Thermal negative type)
The thermal negative photosensitive layer is preferably a negative photosensitive layer in which an infrared laser irradiation portion is cured to form an image portion. A preferred example of such a thermal negative photosensitive layer is a polymerization type layer (hereinafter referred to as “polymerization layer”). 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 (A) infrared absorber include the photothermal conversion substance contained in the above-described thermal positive type photosensitive layer. In particular, as a specific example of the cyanine dye, paragraph number of JP-A No. 2001-133969 [0017] to [0019] may be mentioned.

  (B) Examples of the radical generator include onium salts. Specific examples of onium salts that can be suitably used are described in paragraphs [0030] to [0033] of JP-A No. 2001-133969. Things can be mentioned.

  (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. Among 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 the publications [0036] to [0060] can be used. As other additives, it is also preferable to add an additive (for example, a surfactant for improving coatability) shown in the publications [0061] to [0068].

  Further, it is 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.

  In addition to the polymerization type, an acid-crosslinking layer (hereinafter referred to as “acid-crosslinking layer”) is preferably used as one of the thermal negative photosensitive layers. The acid cross-linking layer includes (E) a compound that generates an 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. Moreover, in order to use the energy of an infrared laser efficiently, (A) infrared absorber is mix | blended with an acid bridge | crosslinking layer.

  (E) As an acid generator, any compound (such as a photopolymerization photoinitiator, a dye photochromic agent, an acid generator used for a microresist, etc., which can generate an acid upon thermal decomposition) For example, 3-diazo-4-methoxydiphenylamine trifluoromethanesulfonate).

  (F) As the crosslinking agent, (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.

  (G) Examples of the alkali-soluble polymer compound include novolak resins and polymers having a hydroxyaryl group in the side chain.

(Photopolymerization type photopolymer type)
A photopolymerizable photopolymer type photosensitive layer for applications such as visible light laser and violet laser is formed from a photopolymerizable photosensitive composition (hereinafter referred to as “photopolymerizable composition”), and the photopolymerizable composition is added. It contains a polymerizable ethylenically unsaturated bond-containing compound (hereinafter simply referred to as “ethylenically unsaturated bond-containing compound”), a photopolymerization initiator, and a polymer binder as essential components, and if necessary, Contains various compounds such as colorants, plasticizers, thermal polymerization inhibitors.

  The ethylenically unsaturated bond-containing compound has an ethylenically unsaturated bond that undergoes addition polymerization, crosslinking and curing by the action of a photopolymerization initiator when the photopolymerizable composition is irradiated with actinic rays. A compound. 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 photopolymerization initiator, various photopolymerization initiators or a combination system (photoinitiation system) of two or more photopolymerization initiators can be appropriately selected and used depending on the wavelength to be used. Initiation systems shown in 2001-22079 [0021]-[0023] are preferred.

  The polymer binder not only functions as a film-forming agent for the photopolymerizable composition but also needs to dissolve the photosensitive layer in an alkali developer, so that the organic polymer is soluble or swellable in alkaline water. A polymer is used. As the polymer, those shown in JP-A-2001-22079 are useful. In addition, it is also preferable to add the additive (for example, surfactant for improving applicability | paintability) shown by the same gazette [0079]-[0088] to a photopolymerizable composition.

  Further, it is 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.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to the range of these Examples.

[Example 1]
A thermal positive type CTP plate was prepared as follows.

A coating solution having the composition shown in Table 1 was applied onto an electrically roughened aluminum substrate using a 12th rod bar and dried at 100 ° C. for 2 minutes. Dry coating weight was 2.0 g / ^{m 2.}

  The “QHB functional cresol novolak resin” in Table 1 was synthesized through the following steps.

(Stage 1)
Synthesis of 6-methylisocytosine
To a 1 liter flask was added 600 ml of dry ethanol and 91.89 g (0.51 mol) of guanidine carbonate and 146.1 g (1.11 mol) of ethyl acetoacetate. The reaction solution was gradually heated to reflux temperature and stirred overnight. 300 ml of ethanol was evaporated and the reaction solution was heated under reflux for 2 hours. After cooling, 300 ml of hexane was added. The precipitate was filtered, washed with water and dried. 119.3 g of 6-methylisocytosine was obtained.

Synthesis of quadruple hydrogen bond (QHBE)
200 g dry N, N-dimethylacetamide (DMA) and 27.56 g (0.22 mol) 6-methylisocytosine were added to a 300 ml flask. To this mixture, 46.65 g (0.21 mol) of isophorone diisocyanate was added, and the flask was sealed from the atmosphere with a conical stopper. The mixture was left at room temperature for 5 days.

(Stage 2)
Synthesis of QHB functional cresol novolac resin
In a 200 ml flask, 27.7 g of m / p-cresol novolak (m / p ratio 6: 4, weight average molecular weight: 5,600) was dissolved in 100 ml of dry N, N-dimethylacetamide. 40% of the Stage 1 mixture (QHBE 0.04 mol) and 0.05 g of di-n-butyltin dilaurate were slowly added with stirring. Stirring was continued at 80 ° C. for 1 day. The isocyanate functionality of the mixture was tested using back titration with the addition of N, N-dibutylamine. The mixture was poured into 1 liter of water. The precipitate was filtered, washed with water and dried to produce 27.8 g of QHB functional cresol novolac resin.

  The thermal positive CTP plate produced as described above was exposed by an infrared laser to form a checkered latent image in which square image portions and non-image portions were alternately arranged.

  Next, the exposed thermal positive type CTP plate was processed using the planographic printing plate processing apparatus of FIG. 1 equipped with the developer supply means shown in FIG. As the developer, a 1: 8 dilution of PD-1 (manufactured by Kodak Graphic Communications) was used. As a developer replenisher, a 1: 3 dilution of PD-1 and a finishing gum solution, PF2 (Kodak) Evaluation was performed with a fatigue developer after 5000 plate processing with a 1: 1.5 dilution of Graphic Communications Co., Ltd.).

[Comparative Example 1]
Using the same lithographic printing plate processing apparatus as used in Example 1 except that the same exposed thermal positive type CTP plate as used in Example 1 lacks the developer supply means shown in FIG. Processing was carried out in the same manner as in Example 1.

[Evaluation]
The contact angle of the image area, the water repelling property, and the non-image area contamination of the thermal positive CTP plates treated in Example 1 and Comparative Example 1 were compared. Use a FACE contact angle meter CA-X type (manufactured by Kyowa Interface Chemical Co., Ltd.), place a CTP plate for measurement in a cell containing distilled water, and oil droplets of Solvesso 150, a hydrocarbon solvent. Was measured in contact with the plate surface. That is, the contact angle here is the contact angle of the oil droplet in the oil-in-water test, and the lower the numerical value, the higher the ink deposition property. The water repellency was determined by visually observing the degree of water repellency after water was sprayed on the plate. The non-image area was visually observed for the presence or absence of dirt. The results are shown in Table 2.

  From the results in Table 2, it can be seen that when a small amount of developer is supplied onto the developed thermal positive type CTP plate, the water repellency of the image area is improved and the ink deposition property is improved. In general, when the contact angle of the oil droplet in the image portion is less than 70 °, the ink inking property is sufficient for practical use and image defects can be avoided. Therefore, it can be seen that image defects are less likely to occur when the planographic printing plate processing apparatus of Example 1 is used than when the planographic printing plate processing apparatus of Comparative Example 1 is used. Further, it can be seen that no undevelopable material adheres to the non-image area, and the occurrence of printing stains can be suppressed.

Schematic sectional view showing an embodiment of the present invention Enlarged conceptual diagram of the part surrounded by the dotted line in FIG. Schematic sectional view showing an embodiment of the additional developer supply means

Explanation of symbols

1: automatic developing device, 2: planographic printing plate, 3: developing unit, 4: cleaning unit, 5: finishing unit, 6: drying unit, 31: developing tank, 32: panel, 33: insertion port, 34: transport roller, 35: lid member, 36: transport roller, 37: transport roller, 38: squeezing roller, 39: brush roller 41: cleaning tank, 42: panel, 43: transport roller, 44: transport roller, 45: spray pipe, 46: Draining roller 51: Finishing tank, 52: Panel, 53: Transport roller, 54: Gum solution replenishing means, 55: Roller, 56: Upper spray pipe, 57: Lower spray pipe 61: Cover, 62: Guide roller, 63: Guide Roller, 64: drying duct, 65: drying duct, 66: outlet, 67: drying molton roller

Claims (7)

A development unit for performing development processing of a lithographic printing plate; and
A lithographic printing plate processing apparatus comprising a washing unit for washing the developed lithographic printing plate carried out from the developing unit,
A pair of squeezing rollers having a smooth surface for removing the developer on the developed lithographic printing plate at the outlet of the developing unit; and
An additional developer supplying means for supplying an additional developer to the surface of the developed lithographic printing plate between the outlet of the developing unit and the inlet of the cleaning unit ;
The additional developer supply means includes a first additional developer holding roller facing one of the squeezing rollers, and the additional developer supplying means is provided between the squeezing roller and the first additional developer holding roller. developing solution, wherein Rukoto stored, planographic printing plate processing apparatus. The processing apparatus according to claim 1, wherein the additional developer supply means includes a spray or dripping device for the additional developer. The processing apparatus according to claim 1 , wherein at least a part of a surface of the first additional developer holding roller is roughened. A development unit for performing development processing of a lithographic printing plate; and
A cleaning unit for cleaning the developed lithographic printing plate transported from the developing unit
A lithographic printing plate processing apparatus comprising:
A pair of squeezing rollers having a smooth surface for removing the developer on the developed lithographic printing plate at the outlet of the developing unit;
A pair of transport rollers for transporting the developed lithographic printing plate into the cleaning section at the entrance of the cleaning section; and
An additional developer supplying means for supplying an additional developer to the surface of the developed lithographic printing plate between the outlet of the developing unit and the inlet of the cleaning unit;
The additional developer supply means includes a second additional developer holding roller facing one of the transport rollers, and the additional developer supply means is interposed between the transport roller and the second additional developer holding roller. A lithographic printing plate processing apparatus in which a developer is stored . The processing apparatus according to claim 4, wherein the additional developer supply means includes a spray or dripping device for the additional developer. The processing apparatus according to claim 4 , wherein at least a part of a surface of the second additional developer holding roller is roughened. The additional developing solution supply means, said supply additional developer directly to the surface of the planographic printing plate between said inlet of said outlet and said cleaning portion of the developing unit, according to any one of claims 1 to 6 Processing equipment.

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