JP7417971B2 - Resin letterpress printing plate, its manufacturing method, and printing device - Google Patents

Description

The present invention relates to a resin relief printing plate, a method for manufacturing the same, and a printing apparatus using the resin relief printing plate.

The photosensitive resin layer of the photosensitive resin plate is irradiated (exposed) with an active light source (ultraviolet light) from the plate material to photocure it, and this exposure creates a relief image and a back folding layer on the photosensitive resin layer of the plate material. is formed. After exposure, when the photosensitive resin plate material is developed with water, the photosensitive resin layer of the plate material is brushed with a cleaning brush using a cleaning solution containing a surfactant, and then washed with water. A plate-making technique is known in which a resin letterpress printing plate is manufactured by removing uncured resin material from a photosensitive resin layer (Patent Document 1).

A resin letterpress printing plate manufactured by the plate making technique of Patent Document 1 is used in a rotary press printing device or a flexo printing device as a letterpress printing machine. A resin letterpress printing plate is installed by being wrapped around the plate cylinder of a printing device, and can be used to print on substrates such as ordinary paper (continuous form or sheet paper), flexible packaging film (plastic film), corrugated paper, etc. Printing is carried out between the plate cylinder and the impression cylinder. The image formed on the print surface of the resin relief printing plate is transferred to the printing material, and printing is performed.

In the plate-making technique described in Patent Document 1, in order to achieve ultimate resolution, it is desirable to use a photosensitive resin plate having a thickness of less than 1 mm. However, in the case of flexographic printing, in order to handle flexible printing materials such as flexible packaging film or diverse printing materials such as corrugated paper, the plate thickness must be thicker even if the resolution of the printed material is slightly reduced. It may be desirable to use a printing plate.
Furthermore, in order to provide various packaging materials with even higher aesthetics, it is expected that various resin letterpress printing plates will be manufactured efficiently, including multicolor printing and support for a variety of packaged items. be done.

Patent No. 5225237

A resin letterpress printing plate manufactured by a conventional plate-making technique is formed into a plate cylinder by wrapping the plate cylinder of a rotary press printing device or a flexographic printing device with a double-sided adhesive tape.

BACKGROUND ART There is a plate cylinder for a rotary press printing device or a flexo printing device in which a single endless resin letterpress printing plate is wrapped around the plate cylinder cylinder. The plate cylinder of a flexographic printing apparatus uses a resin letterpress printing plate wound around a hollow plate cylinder, and a printing material is passed between the plate cylinder and the impression cylinder as a printing medium.

In flexographic printing, the printing pressure of the surface of a plastic letterpress printing plate (on a plate cylinder) is applied to the substrate. Kisspress is said to be the best printing pressure for flexo printing. In order to constantly apply the printing pressure of the kiss press to the printing material, high mechanical precision of the printing device and high rotational precision of the plate cylinder and impression cylinder are required.

The plate cylinder of a flexo printing machine is not a heavy solid cylinder, but a lightweight hollow cylinder. If there is a step in the seam of the plastic letterpress printing plate that is wrapped around the plate cylinder cylinder, each time the printing material (passed between the plate cylinder and the impression cylinder) passes through the seam of the plastic letterpress printing plate, , bounding (dancing) occurs on the plate cylinder due to seams.
When bounding occurs on the plate cylinder, the printing pressure applied to the printing material by the plate cylinder fluctuates and changes, causing blurring, resulting in a problem of lack of printing stability and difficulty in maintaining a constant printing quality.

The present invention has been made in consideration of the above-mentioned circumstances, and prevents the occurrence of bounding on the plate cylinder even if a step occurs at the seam of the resin letterpress printing plate when the resin letterpress printing plate is wound around the plate cylinder cylinder. It is an object of the present invention to provide a resin letterpress printing plate, a method for manufacturing the same, and a printing device that can prevent the above problems and provide good printing quality for printing on a printing material.

The resin letterpress printing plate according to the present invention is a rectangular resin letterpress printing plate which is wound around a plate cylinder cylinder via a double-sided adhesive tape to constitute a plate cylinder, and is provided between the plate cylinder and the impression cylinder. A resin relief printing plate for guiding a printing material to perform printing, the resin relief printing plate having marginal zones formed in the longitudinal direction on both sides of the image area in the central area, the resin relief printing plate A recess cut out in the longitudinal direction of the plastic letterpress printing plate is formed only at one end of the marginal zone among one end of the letterpress printing plate, and a recessed portion cut out in the longitudinal direction of the resin letterpress printing plate is formed at one end of the marginal zone at the other end of the plastic letterpress printing plate. A convex portion projecting in the longitudinal direction is formed only at the other end, and when the resin relief printing plate is wound around the plate cylinder, the image of the one end of the resin relief printing plate is formed. The other end of the drawing part of the resin relief printing plate is butted against one end of the line part to form a seam in the width direction, and the one end of the marginal zone The concave portion and the convex portion of the other end of the marginal zone are butted against each other to form a joint, and the joint of the marginal zone is not aligned in a straight line in the width direction of the seam of the resin letterpress printing plate. , is characterized in that it extends from the joint portion so as to include components in the longitudinal direction and the width direction .

The resin letterpress printing plate according to the present invention is the resin letterpress printing plate according to claim 1 or 2, wherein a plurality of the resin letterpress printing plates are prepared and wound in series around a plate cylinder cylinder via a double-sided adhesive tape. Among the plurality of plastic letterpress printing plates, the one end of the subsequent plastic letterpress printing plate is butted against the other end of the preceding plastic letterpress printing plate and joined sequentially, and the final plastic letterpress printing plate is formed. It is characterized in that the one end of the foremost resin letterpress printing plate is butted against and joined to the other end of the printing plate.

The method for producing a resin letterpress printing plate according to the present invention involves irradiating a rectangular photosensitive resin plate with energy light of a required wavelength from an active light source, and forming a relief image and a background image on the photosensitive resin layer of the plate. An exposure step for forming a deposited layer, and the exposed plate material is conveyed to a cleaning device, where the cleaning device sprays a cleaning liquid onto the photosensitive resin layer of the plate material and performs brush cleaning by sliding a cleaning brush. and a water washing step for removing uncured resin material from the photosensitive resin layer, and a cutting step for cutting the resin letterpress printing plate to be made into a desired shape after removing the uncured resin material, In the method for manufacturing a resin relief printing plate in which a marginal zone is formed on both sides of an image area in a central area, a longitudinal edge of the resin relief printing plate is formed only at one end of the marginal zone among one end of the resin relief printing plate. a concave portion is formed by notching in the direction, and a convex portion is formed by protruding in the longitudinal direction only at the other end of the marginal zone among the other end portions of the resin letterpress printing plate , and the resin letterpress printing plate When the plate is attached to be wound around a plate cylinder, one end of the image area of the one end of the resin relief printing plate and the other end of the image area of the other end of the resin relief printing plate are attached. The concave portion at the one end of the marginal zone and the convex portion at the other end of the marginal zone are butted against each other to form a joint in the width direction, and the marginal zone The joint portion is not aligned in a straight line in the width direction of the seam portion of the resin relief printing plate, but is shifted from the seam portion so as to have components in the longitudinal direction and the width direction. This is the manufacturing method.

A printing apparatus according to the present invention includes: a resin letterpress printing plate in which a marginal zone is formed in the longitudinal direction on both sides of an image area; a plate cylinder configured by winding the resin letterpress printing plate around a plate cylinder cylinder; It has an impression cylinder provided opposite to the plate cylinder, and a printing unit equipped with an inking mechanism that supplies ink to the resin letterpress printing plate of the plate cylinder, and the plate cylinder and the impression cylinder of the printing unit are connected to each other. In a printing device that prints on a printing material through a printing material during printing, a recess cut out in the longitudinal direction of the resin relief printing plate is formed only at one end of the marginal zone among one end of the resin relief printing plate. and a protrusion projecting in the longitudinal direction is formed only at the other end of the marginal zone among the other ends of the resin relief printing plate , and the resin relief printing plate is wound around the plate cylinder. When attached , the other end of the image portion of the other end of the resin relief printing plate is butted against one end of the image portion of the one end of the resin relief printing plate, and a seam is formed. A joint portion is configured in the width direction, and a joint portion is configured in which a concave portion at the one end portion of the marginal zone and a convex portion at the other end portion of the marginal zone are abutted against each other, and the joint portion of the marginal zone is configured such that: The resin relief printing plates are characterized in that they are not aligned in a straight line in the width direction of the seam of the resin relief printing plate, but extend from the seam so as to have components in the longitudinal direction and the width direction .

The present invention provides a resin relief printing plate at a joint portion of the marginal zone where a concave portion on one end side of the marginal zone and a convex portion on the other end side of the plastic letterpress printing plate that is wound around the plate cylinder are abutted, and at a seam portion of the plastic letterpress printing plate. It does not have linear steps aligned in the width direction, and a non-step guide surface can be formed at the joint, allowing the plate cylinder around which the resin letterpress printing plate is wrapped to rotate smoothly and smoothly during printing. Bounding and rattling can be prevented, and good print quality can be achieved on printing substrates.

FIG. 2 is a perspective view showing a plate material of a photosensitive resin plate used for manufacturing a resin letterpress printing plate. (A) to (G) are schematic diagrams showing the plate-making process of a resin letterpress printing plate produced from a photosensitive resin plate material. FIG. 1 is a plan view showing an actual form of a resin relief printing plate according to the present invention. This is a side configuration diagram of a plate cylinder in which a resin letterpress printing plate is wound around the plate cylinder. (A) is a schematic configuration diagram of a plate cylinder in which a single (one sheet) resin letterpress printing plate is wound, and (B) ) is a schematic configuration diagram of a plate cylinder around which a plurality of (for example, two) resin letterpress printing plates are wound. This figure partially shows the seam of the plastic letterpress printing plates that are wrapped around the plate cylinder. (A) shows the state immediately before the ends of the plastic letterpress printing plates are butted together, and (B) shows the plastic letterpress printing plates. FIG. 3 is a joining diagram showing a butt state of each end of the printing plate. FIG. 3 is a joint diagram showing a first modified example of a resin letterpress printing plate in which each end is butted against each other. FIG. 7 is a joint diagram showing a second modified example of the resin relief printing plate in which the ends are butt-matched. FIG. 6 is a joint diagram showing a third modification of the resin letterpress printing plate in which the ends are butt-matched. FIG. 2 is a measurement data diagram showing the relationship between the relief depth, floor layer, and back deposited layer thickness of a rubber-based resin letterpress printing plate (plate material thickness: 1.14 mm). A measurement data diagram showing the relationship between relief depth, floor layer, and back deposited layer thickness of a rubber-based resin letterpress printing plate (plate material thickness: 1.70 mm). A measurement data diagram showing the relationship between the relief depth, floor layer, and back deposited layer thickness of a rubber-based resin letterpress printing plate (plate material thickness: 2.84 mm). FIG. 1 is a schematic configuration diagram showing an example in which a resin relief printing plate according to the present invention is applied to an in-line flexo printing apparatus. 13 is a simplified configuration diagram showing a printing unit included in the flexo printing apparatus shown in FIG. 12. FIG. 1 is a schematic configuration diagram showing an example in which a resin relief printing plate according to the present invention is applied to a drum-type flexographic printing device. 15 is a simplified configuration diagram showing a printing unit included in the flexo printing apparatus shown in FIG. 14. FIG. 15 is a simplified configuration diagram showing another example of a printing unit included in the flexo printing apparatus shown in FIG. 14. FIG. 1 is a schematic configuration diagram showing an example in which a resin relief printing plate according to the present invention is applied to a stack type flexo printing apparatus. 18 is a simplified configuration diagram showing a printing unit included in the flexo printing apparatus shown in FIG. 17. FIG.

Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a plate material 10 of a photosensitive resin plate used for manufacturing a resin letterpress printing plate. This plate material 10 has an analog version and a digital version. The analog version and the digital version include, for example, a photosensitive resin plate used in a resin letterpress printing plate described in Japanese Patent No. 5225327. For analog versions, a negative film is used as a plate-making film, and for digital versions, a CTP (Computer to Plate) plate material that does not require a plate-making film is used. A CTP plate material refers to a plate material in which a heat-sensitive layer (ablation mask) serving as an image mask is integrated on the surface of a photosensitive resin layer.

Specific examples of the photosensitive resin plate material 10 include CTP flexo plates such as Cosmolite QS114U, QS170F, QS284F, Cosmolite QH, Cosmolite QZ manufactured by Toyobo Co., Ltd., and Fuji Film Global Graphic Systems (FFGS). ) Co., Ltd.'s product names include water-developable flexo plates and flexo plates such as FLENEX FW series (FW-L, FW-A, FW-U). Flexo printing plates are widely used for printing flexible packaging films such as plastic films, general paper (continuous forms and sheet paper), paper cartons, paper bags, corrugated paper, and industrial parts such as electronic parts.

The plate material 10 of the photosensitive resin plate is a flexo plate material with a Shore A hardness of, for example, 30 degrees to 82 degrees, preferably 68 degrees to 82 degrees, and since flexo plates are generally rubber-based, it is suitable for letterpress plates. Softer than photosensitive resin plate material. Further, for example, the vertical direction (longitudinal direction) of the flexo plate material is 762 mm to 1540 mm, and the width direction is 635 mm to 1067 mm. In addition, the vertical direction (longitudinal direction) of the photosensitive resin plate material is several meters (for example, 3 m) to 9 m, and the plate thickness of both plates is 0.70 mm to 2.84 mm. Analog or digital plates are used. It will be done.

In a photosensitive resin plate material 10, as shown in FIG. 1, a photosensitive resin layer 13 is integrally laminated on a polyethylene film base film (film support) 11 as a substrate via an adhesive layer 12. An ablation mask 14 that responds to laser light of a desired wavelength, for example, infrared laser light, is integrally mounted on this photosensitive resin layer 13. A black mask layer that reacts with infrared laser light is formed on the ablation mask 14, and the black mask layer reacts with the laser light to form a plate-making pattern. A cover film 15 is placed on the ablation mask 14 . Note that the photosensitive resin layer 13 has no sensitivity to irradiation with infrared laser light and does not react to the irradiation.

When the plate material 10 of the photosensitive resin plate is a flexo plate material, the rubber-based photosensitive resin layer 13 contains, for example, a polymerizable compound and a photopolymerization initiator, and the required wavelength of the active light source, for example, 300 nm to 400 nm. A photocurable resin that photocures in response to wavelength energy light (UV light) is used. As the photopolymerization initiator, for example, benzoin-based or acetophenone-based photopolymerization initiators can be used. This photocurable resin may contain at least one of a solvent and an additive.

When the plate material 10 of the photosensitive resin plate is a rubber-based flexographic plate material of Cosmolite QS114U, the photosensitive resin layer 13 is made of, for example, synthetic rubber, liquid rubber, polyurethane methacrylate compound, acrylate compound, and photopolymerization initiator. It consists of agents, etc. Further, when the photosensitive resin plate material 10 is a flexographic plate material of the FLENEX FW series (FW-L, FW-A, FW-U), the photosensitive resin plate layer 13 is made of, for example, a polymer, methacrylate ester. It consists of system monomers, additives, photopolymerization initiators, etc.

In addition, the photosensitive resin plate layer 13 is made of an unsaturated polyester resin, polybrasian, or a photocurable resin to which an unsaturated group such as acrylic or urethane is introduced, and a photosensitizer or a thermal stability added to the unsaturated resin layer. You can.

As an example of a preferable rubber-based photosensitive resin plate material 10, in the case of a flexographic plate material, when the plate thickness is 1140 μm, the base film 11 has a film thickness of 125 (or 188) μm, and the antihalation adhesive layer 12 has a thickness of 125 (or 188) μm. The layer thickness of the photosensitive resin plate layer 13 is 995 (or 932) μm. The film base 16 (base film 11+adhesive layer 12) as a film support has a base thickness (support film thickness) of 145 (208) μm.

In addition to polyester film, the base film 11 includes polyethylene terephthalate (PET film), plastic resin film such as polyvinyl chloride, synthetic rubber film such as styrene-butadiene rubber, glass fiber reinforced plastic resin film, and epoxy resin. A film or a phenol resin film may also be used. For the adhesive layer 12, various coating materials are used, such as coating with a rubber-based, polyester-based, epoxy-based, acrylic-based, or urethane-based adhesive, or anchoring with a coupling agent.
Next, a case will be described in which a resin letterpress printing plate is manufactured using the plate material 10 of the photosensitive resin plate.
An example will be described in which a photosensitive resin letterpress printing plate 18 is manufactured using a CPT (Computer to Plate) type rubber-based flexo plate material as the photosensitive resin plate material 10.

Among the plate materials 10 of the photosensitive resin plate, the rubber-based flexographic plate material is made of Cosmolite QS, QH, QZ, etc., and has a plate thickness of 700 μm to several thousand (7000) μm, preferably 1000 μm to 4000 μm, more preferably There are many types of plate materials having a diameter of 1140 μm to 2840 μm. Among these, the plate material 10 of the photosensitive resin plate shows an example of a plate making technique in which a photosensitive resin letterpress printing plate 18 is manufactured using a CTP type flexo plate material having a plate thickness of 1140 μm. Compared to photosensitive resin (letterpress) plates, which are commonly used for paper printing such as letterpress, flexo plates have a smaller Shore A hardness and are softer when the plate thickness is the same. Ru.

When producing the photosensitive resin letterpress printing plate 18, a CTP plate material of a flexographic plate material and a transparent film 19 are prepared for the photosensitive resin plate material 10 shown in FIG. 2(A). First, the cover film 15 is removed from the CTP plate material 10 of the photosensitive resin plate.

Subsequently, the ablation mask 14 side of the plate material 10 is irradiated with infrared laser light L in a pattern as shown in FIG. 2(B) to form a plate-making pattern on the ablation mask 14. The CTP plate material 10 does not require a negative film, which is a plate-making film.
After a plate-making pattern is formed on the ablation mask 14 of the CTP plate material 10, the plate material 10 is sent to a lamp house of an exposure apparatus (not shown).

[Exposure process]
The CTP plate material 10 transported to the lamp house constituting the exposure apparatus is run at a predetermined speed inside the lamp house, and as shown in FIG. Energy light is irradiated. As an active light source, for example, an ultraviolet light source is used to irradiate ultraviolet light (UV light) with a wavelength of 315 nm to 400 nm, and relief exposure, which is main exposure, is performed. In addition to the ultraviolet light source, the active light source 20 for relief exposure includes a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a carbon arc lamp, a xenon lamp, etc. in the wavelength range of 300 nm to 400 nm. It is preferable that the light source be close to a surface light source rather than a point light source. Inside the lamp house, an active light source may be run instead of running the CTP plate material 10.

In the relief exposure, ultraviolet rays of a predetermined amount of light, for example about 13,000 mj/cm ² , are incident on the photosensitive resin layer 13 of the CTP plate material 10 through the plate-making pattern of the ablation mask 14 . When the photosensitive resin layer 13 is irradiated with strong ultraviolet energy, the photosensitive resin layer 13 in the irradiated area undergoes a photoreaction and is photocured. By this photocuring, relief images 22 of characters and images constituting the cured area are formed in the image area (irradiation area) of the photosensitive resin layer 13 of the CTP plate material 10 . The relief image 22 is stably formed in a tapered shape that widens toward the base film 11. The relief image 22 does not necessarily need to be formed over the entire thickness of the photosensitive resin layer 13, and may have a relief height of several hundred μm, for example, about 110 μm to 700 μm on the ablation mask 14 side. In this case, the energy light can form a relief image by injecting ultraviolet light with a light intensity of 5,000 mj/cm ² .

The maximum height of the relief image is determined by the thickness of the photosensitive resin layer 13. The photosensitive resin layer 13 is used to harden the latent relief image 22 deep into the image (line) area. Normally, the active light source 20 is irradiated with strong energy light, for example, in the case of an ultraviolet light source, an energy light amount of about 5,000 mj/cm ² or more, preferably about 13,000 mj/cm ² , is irradiated for printing exposure. When ultraviolet rays are irradiated with an energy light amount of about 13,000 mj/cm ² for the required time, for example, 30 minutes, the irradiated area of the photosensitive resin layer 13 undergoes a photoreaction and forms a relief image (latent) with a required relief depth (height). image) 22 is stably formed. Further, when forming the relief image 22 only near the surface layer of the photosensitive resin layer 13, the energy light for relief exposure may have a light intensity of about 5,000 mj/ ^cm2 , but does not necessarily have a light intensity of 13,000 mj/ ^cm2 . does not require.

After the relief image 22 is formed on the photosensitive resin layer 13, the CTP plate 10 is taken out from the lamp house and turned over, and an active light source is irradiated from the back side of the CTP plate 10 through the transparent film 19 for back exposure. Ru. The film 19 is aligned and vacuum-adhered to the ablation mask 14, and is vacuum-fixed. This vacuum fixing prevents misalignment and uneven adhesion between the CTP plate material 10 and the film 19.

After performing relief exposure on the CTP plate material 10 of the photosensitive resin plate, it is taken out, reversed, and passed through the film 19 fixed to the base film 11 side of the CTP plate material 10 to emit an energy light amount that is less than the light amount for relief exposure. Back exposure is performed. In the back exposure, active light, for example ultraviolet light, having an energy intensity of 0.03 to 1 times (equal) that of the relief exposure is incident from the active light source onto the photosensitive resin layer 13 from the film 19 side through the film base 16. In back exposure, for example, an amount of ultraviolet light of 370 mj/cm ² to 10,000 mj/cm ² is incident, and the photosensitive resin layer 13 is solidified (photocured) in a layer on the film base 16 side to a required height (solidified area). ) is formed, and a back deposit layer (back solidified layer) 23 is formed on the entire surface. The height of the back folding layer 23 can be adjusted by the back exposure time and the intensity of the energy light amount of the back exposure.

In the exposure step, the back deposited layer 23 is formed after the relief image 22, so the light source is preferably a line light source or a surface light source rather than a point light source. If the relief exposure amount is small, the relief image 22 itself may be missing or the shoulder may be too high, which may impair printing durability. If the relief exposure amount is too large, the shadow areas of halftone dots and characters tend to become thicker, and the depth of non-image areas becomes shallower, making it easier for ink to clog during printing, which causes a loss in print quality.

The relief depth (relief height) of the relief image 22 is determined by adjusting the exposure amounts of relief exposure and back exposure acting on the photosensitive resin layer 13. If the depth is less than about 100 to 110 μm, background staining may occur on the printed member during printing, which is not preferable. On the other hand, if the relief depth (relief height) is too large, the relief image 22 may be bent, damaged, or deformed during printing, which is not preferable. Therefore, the relief depth (relief height) of the relief image 22 is preferably in a range of about 110 μm or more, preferably about 700 μm or less.

The CTP plate material 10 is reinforced by forming a floor by integrally forming the back extraction layer 23 on the film base 16 side of the photosensitive resin layer 13, thereby increasing the mechanical, physical and chemical strength of the CTP plate material 10. can be improved. The thicker the back deposit layer 23 is, the more the strength of the CTP plate material 10 can be improved. The height (relief depth) of the relief image 22 is determined by subtracting the height of the back deposit layer 23 from the layer thickness of the photosensitive resin layer 13. As a result, in flexo-in printing, the relief height (relief depth) of the relief image 22 is preferably 110 μm or more, preferably about 300 μm to 500 μm, using a flexo plate material (for flexible packaging film printing) where kiss press printing is preferable. is preferably configured.
Furthermore, in FIGS. 2(C) and (D), relief exposure and back exposure may be performed simultaneously on the CTP plate material 10 of the photosensitive resin plate, or back exposure may be performed prior to relief exposure. .

Back exposure is performed to form a back deposition layer 23, and the relief depth is made shallow to about 110 μm to 500 μm, thereby reducing the amount of light for relief exposure, and forming a relief image 22 with UV light of about 5,000 mj/cm ² , for example. can do. The smaller the amount of light for relief exposure, the more clearly the solid white outline can be cleaned during printing. Further, by making the relief depth shallow, the amount of resin washed out of the uncured portion during water development can be reduced, and the washing time can also be shortened, so that the water washing efficiency can be improved. Furthermore, by combining the resin letterpress printing plate 18 with a printing device (described later) that causes less bounding (dancing) of the plate cylinder during printing, small halftone dots and fine image areas can be printed neatly.

[Water development process]
In the exposure process of relief exposure and back exposure, the CTP plate material 10 that has undergone photocuring action is sent to a cleaning device as shown in FIG. 2(E) after peeling off and removing the transparent film 19, etc. A water development step (water washing step) is performed within the washing zone. In the water development process, the CTP plate material 10 is conveyed horizontally within a washing zone and washed with water.

The CTP plate material 10 is subjected to spraying (cleaning) of a cleaning liquid in a cleaning zone and brush cleaning in which a flat cleaning brush 25 (hereinafter referred to as a cleaning brush) slides and rotates. By this water washing, uncured resin material from the photosensitive resin layer 13 of the CTP plate material 10 is separated from the photocured portion (relief image 22 and back deposited layer 23) and removed.

FIG. 2(E) shows an example in which one cleaning brush 25 is used. Actually, a plurality of sets, for example, two sets of flat cleaning brushes 25 are provided. A plurality of cleaning brushes 25 are used in the cleaning brush unit, and the surface of the photosensitive resin layer 13 of the plate material 10 is cleaned by rotating each group. However, each set of cleaning brushes 25 is rotated while maintaining a constant rotational angle difference (rotation phase difference) for each set, so that the brush pressure of each set of cleaning brushes 25 is adjusted to the resin of the plate material 10. The direction of action on the surface can be varied and dispersed.

When each set of cleaning brushes 25 slides while rubbing the resin surface of the CTP plate material 10 for brush cleaning, the brush pressure acting on the CTP plate material 10 is not directed in the same direction. Since the brush pressure exerted by the cleaning brushes 25 on the CTP plate material 10 is distributed for each set, the CTP plate material 10 can be effectively prevented from falling off or being shifted and damaged during water washing.

Further, the photosensitive resin layer 13 of the CTP plate material 10 that is brush-cleaned by each set of cleaning brushes 25 is brushed while a hot water cleaning liquid is sprayed from a nozzle (not shown). The cleaning liquid is washed with hot water heated to, for example, 40°C to 60°C, preferably about 50°C.

As shown in FIG. 2(E), during the water development process, uncured resin material is removed from the photosensitive resin layer 13 of the CTP plate material 10 from the cured portion by spraying a cleaning liquid and cleaning the cleaning brush 25. separated and removed. In the CTP plate material 10, the back deposited layer 23 of the cured resin material and the relief image 22 are left integrally fixed on the frame base 16.

The relief image 22 is fixed and integrally formed on the back deposited layer 23 forming the floor. In this way, the relief image 22 is formed on the back deposited layer 23 that is integrated with the frame base 16, and the photosensitive resin letterpress printing plate 18 is manufactured.

Note that in order to promote separation and removal of unreacted uncured resin during exposure, a cleaning solution containing a pH adjuster and a surfactant is used as an aqueous developer in the water washing step. The photosensitive resin plate layer 13 is a photocurable resin material that is solidified and photocured by a photoreaction, and the photocurable resin in the cured portion has no solubility or lubricity in an aqueous developer and has no chemical resistance to an aqueous developer. It is given and left as a relief statue. The photosensitive resin letterpress printing plate 18 is formed on the frame base 16 with a relief image 22 having excellent mechanical, physical and chemical strength supported by a back deposition layer 23. As the surfactant added to the cleaning liquid, specifically, an alkaline aqueous surfactant, such as a dishwashing detergent or a laundry detergent, is used.

Further, the photosensitive resin plate material 10 that has been cleaned with the cleaning liquid is washed with warm water depending on the structure of the flexographic plate material, and a photosensitive resin letterpress printing plate 18 is manufactured. Further, when water washing is performed using an activator of an alkaline aqueous solution as a washing liquid, the surface of the photosensitive resin plate 10 is washed using water such as tap water and a rinsing liquid.
By washing with the rinsing liquid, foreign substances such as dust and uncured residual resin material adhering to the surface of the plate material 10 are removed, and the photosensitive resin letterpress printing plate 18 is manufactured.

The photosensitive resin letterpress printing plate 18 is then sent to a dryer 26 such as a heater and subjected to a drying process, as shown in FIG. 2(F). After the drying process, it may be installed in a printing apparatus to be described later, but in order to further improve printing durability, a post-exposure process may be performed in a post-exposure process.

In the post-exposure step shown in FIG. 2(F), the photosensitive resin letterpress printing plate 18 is post-exposed using UV energy light from an active light source, thereby increasing the intensity of the highlights of halftone dots and thin lines. can. In addition, the bonding strength between the relief image 22 and the back deposited layer 23 and the strength of the back deposited layer 23 as a floor (which is integrally bonded to the base film 11) can be improved.

The photosensitive resin letterpress printing plate 18 manufactured through the water development step of FIG. 2(E) and the drying step and post-exposure step of FIG. 2(F) is sent to the cutting step shown in FIG. 2(G). In this cutting step, the rectangular resin letterpress printing plate 18 is cut by a cutting device 27 such as a cutter, and a resin letterpress printing plate 30 having a shape suitable for wrapping around a plate cylinder, which will be described later, is manufactured. In this way, the plate material 10 of the photosensitive resin letterpress printing plate shown in FIG. 1 is used for resin letterpress printing, which is wound around the plate cylinder of a printing device through the plate-making process schematically shown in FIGS. 2(A) to 2(G). A plate 30 is manufactured.

The photosensitive resin letterpress printing plate 18 is cut into a desired shape by the cutting device 27 in the cutting process shown in FIG. 2(G), and the resin letterpress printing plate 30 shown in FIG. 3 is manufactured. When this resin letterpress printing plate 30 is wound around the plate cylinder 35 so that its front end (one end) 37 and rear end (other end) 38 are butted against each other, as shown in FIGS. It is configured as shown in B). FIG. 4(A) is a side view showing an example of a wrapping state in which a single (one sheet) resin letterpress printing plate 30 is wound around the plate cylinder cylinder 35, and FIG. FIG. 3 is a side view showing a state in which a plurality of (for example, two) resin letterpress printing plates 30 are wound. In FIGS. 4(A) and 4(B), the entire surface of the resin relief printing plate 30 is wrapped around the plate cylinder 35 with a double-sided adhesive tape 36 interposed therebetween, and is fixed thereto.

[Resin letterpress printing plate]
FIG. 3 is a plan view showing an embodiment of a resin relief printing plate according to the present invention.
A rectangular photosensitive resin letterpress printing plate 18 is produced from the photosensitive resin plate material 10 shown in FIG. 1, and this photosensitive resin letterpress printing plate 18 is cut into the desired shape in the cutting process shown in FIG. The resin letterpress printing plate 30 is made by cutting. The resin relief printing plate 30 has a substantially rectangular shape, as shown in FIG. 3 in a plan view. As shown in FIG. 3, the resin letterpress printing plate 30 has an image area 33 formed in a band shape on the plate surface in the central region, and marginal zones 34 on both outer sides of the resin letterpress printing plate 30, and thus on both sides of the image area 33. provided. When the resin letterpress printing plate 30 is wrapped around the plate cylinder (roller) 35 shown in FIG. The end portions (rear end portions) 38 sides are butted and joined to form a joint portion 39.

The marginal zones 34 form a pair along the longitudinal direction (vertical direction) of the resin letterpress printing plate 30, and a concave portion (with a trapezoidal cutout on the outer side) on one end (tip) side of the marginal zone 34 ( A notch) 40 is formed. The recess 40 is formed by being cut in a tapered shape in the longitudinal direction outside the marginal zone 34.

The other end (rear end) side of the marginal zone 34 is formed into a convex portion 41 that projects in a trapezoidal shape. The convex portion 41 protrudes in a tapered trapezoidal shape from the other end of the marginal zone 34 in the longitudinal direction. When the resin letterpress printing plate 30 is wound around the plate cylinder 35, the convex portions 41 of the marginal zone 34 butt against the concave portions 40 to form a joint portion 44. The convex part 41 of the marginal zone 34 butts against and fits into the concave part 40 of the joint part 44, forming a concavo-convex joint part so as to form a mutually complementary shape. Here, the complementary shape refers to a mutually complementary shape relationship such that one recess 40 fits into the other protrusion 41.

Therefore, when the resin letterpress printing plate 30 is wound around and mounted on the plate cylinder cylinder 35, the joint part 44 of the marginal zone 34 extends from the joint part 39 in the rotational direction of the plate cylinder 35, and is guided. ing. The joint portion 39 of the resin letterpress printing plate 30 is not aligned in the width direction with the joint portion 44 of the marginal zone 34, but is configured at a position shifted in the rotation direction.

By the way, at the other end (rear end) 38 of the resin letterpress printing plate 30, a width direction recess 45 is formed by cutting out the rear end side of the printing area 33 in a trapezoidal shape in the width direction. This recessed portion 45 extends outward on both sides along the width direction on the rear end side of the image portion 33, and ends with both ends entering the marginal zone 34. The resin letterpress printing plate 30 has a width direction recess 45 cut out in a trapezoidal shape on the other end (rear end) 38 side, so that the marginal zone 34 integrally projects in the longitudinal direction toward the other end (rear end) side. A convex portion 41 is consequently provided. The convex portion 41 protrudes in a trapezoidal shape toward the other end (rear end) side of the marginal zone 34, and is abutted against the concave portion 40 at one end of the marginal zone 34, as shown in FIGS. 5(A) and (B). Mated and joined as shown.

In this way, the concave portion 40 of the marginal zone 34 formed on the resin relief printing plate 30 and its convex portion 41 are butted against each other and joined, and are fitted into the concave and convex portions. The concave portion 40 and convex portion 41 of the marginal zone 34 are configured to have a complementary shape. The concave portion 40 of the marginal zone 34 is formed by cutting out both corner portions of one end (front end) of the resin letterpress printing plate 30, and the convex portion 41 of the marginal zone 34 is formed by cutting out the other end (rear end) of the resin letterpress printing plate 30. It is configured to extend in the longitudinal direction from the end) side. The concave portion 40 and the convex portion 41 are butted against each other to form a concave-convex joint (concave-convex fitting portion). In the resin relief printing plate 30, a corresponding portion 42 is formed on the inner side in the width direction of the convex portion 41 constituting the concavo-convex joint portion. The corresponding portions 42 extend in the longitudinal direction and are integrally connected to one end (tip) of the marginal zone 34, and are provided on both sides of the one end (tip) of the resin letterpress printing plate 30. In the marginal zone 34, the convex portion 41 and the corresponding portion 42 constitute a joint portion 44, and a guide surface is formed on the surface of the joint portion 44 of the marginal zone 34. , the joint portion 44 of the marginal zone 34 extends from the seam portion 39 of the resin letterpress printing plate 30 in the rotational direction of the plate cylinder 35. The guide surface of the joint portion 44 of the marginal zone 34 is such that the surfaces of the convex portion 41 extending from the rear end portion and the corresponding portion 42 integrally connected to the tip portion of the marginal zone 34 are in common with the surface of the marginal zone 34. It is formed. Since there is no linear seam extending in the width direction in the joining portion 44 of the marginal zone 34, no stepped portion in the width direction is formed. The joint portion 44 of the marginal zone 34 constitutes a guide surface of a non-step portion continuous to the joint portion 44 even if a step portion is formed at the seam portion 39 of the resin letterpress printing plate 30.

By the way, a resin letterpress printing plate 30 made from the photosensitive resin plate material 10 is constructed as shown in FIG. 3. This resin letterpress printing plate 30 is fixed to a plate cylinder cylinder 35 shown in FIG. 4 by being wrapped with a double-sided adhesive tape 36, thereby forming a plate cylinder 48 (48A) of a printing apparatus to be described later. The double-sided adhesive tape 36 is used to wrap the resin letterpress printing plate 30 around the plate cylinder 35. The tape thickness of the double-sided adhesive tape 36 is about several μm to 100 μm, preferably about 10-odd μm. FIG. 4(A) shows an example of a plate cylinder 48 configured by wrapping a single resin letterpress printing plate 30 around the plate cylinder cylinder, and FIG. 4(B) shows a plurality of sheets, for example, two resin letterpress printing plates 30. An example of a plate cylinder 48A constructed by winding the plate cylinder around the plate cylinder is shown. The resin letterpress printing plate 30 wound around the plate cylinder is a printing plate made from a plate material 10 having a plate thickness of 700 μm to several thousand μm, for example 7000 μm, preferably 1000 μm to 4000 μm, more preferably 1140 μm to 2840 μm. Ru.
The vertical and horizontal dimensions of the resin letterpress printing plate 30 are adjusted and set as appropriate depending on the effective diameter of the plate cylinder cylinder 35 and the effective axial length of the plate cylinder cylinder 35.

Now, when a single resin letterpress printing plate 30 is wound around the plate cylinder cylinder 35, the plate cylinder 48 is arranged so that the leading end 37 and the rear end 38 of the resin letterpress printing plate 30 butt against each other, as shown in FIG. 4(A). The double-sided adhesive tape 36 is wound around the plate cylinder 35 so as to be structured as shown in FIGS. 5(A) and 5(B). FIG. 5(A) is a state diagram showing the vicinity of the seam portion 39 immediately before the wrapping of the resin letterpress printing plate 30 around the plate cylinder 35 is completed. FIG. 5(B) is a state diagram showing a joined state near the seam portion 39 after the wrapping of the resin letterpress printing plate 30 is completed.

In addition, as shown in FIG. 4(B), when two resin letterpress printing plates 30 are wound around the plate cylinder 35, the trailing resin letterpress printing plate is printed on the rear end portion 38 of the preceding resin letterpress printing plate 30. The tip portions 37 of the plates 30 are butted and joined to form a joint portion 39. Subsequently, the trailing resin letterpress printing plate 30 is wound around the resin letterpress printing plate 30, and its rear end portion 38 is butted against the leading end portion 37 of the preceding resin letterpress printing plate 30. In this way, the two resin letterpress printing plates 30, 30 are wrapped around the plate cylinder cylinder 35 via the double-sided adhesive tape 36, thereby forming the plate cylinder 48A. At this time, in each resin letterpress printing plate 30, the joint portion 44 of the marginal zone 34 extends from the joint portion 39 of the resin letterpress printing plate 30 in the rotation direction and is shifted, and the concave portion 40 and the convex portion 41 of the marginal zone 34 are shifted. They are butted against each other and wrapped around each other.

Here, as shown in FIG. 3, if the vertical dimension (longitudinal length) of the resin letterpress printing plate 30 is VL, and the horizontal dimension (width direction length) is WL, the apparent length and width of the resin letterpress printing plate 30 are The dimensions are not different from the vertical and horizontal dimensions (VL×WL) of the resin letterpress printing plate 30. However, the effective dimension L in the longitudinal direction of the resin letterpress printing plate 30 is the length of the photosensitive resin letterpress printing plate 18 by the notch width ΔL of the width direction recess 45 (taking into account the recess 40 of the marginal zone 34 and the width direction recess 45). It is shorter than the direction dimension VL. The notch width ΔL of the width direction recess 45 is configured to be equal to the longitudinal length ΔL of the recess 40 and the projection 41 of the marginal zone 34 .

Therefore, the number of resin letterpress printing plates 30 wound around the plate cylinder cylinder 35 is n, the diameter of the plate cylinder 35 is D, the effective axial length of the plate cylinder 35 is ΔL, and the tape thickness of the double-sided adhesive tape 36. When the length is t, the following relational expression is established between the resin letterpress printing plate 30 and the plate cylinder 35. The effective longitudinal dimension L and width dimension WL of the resin letterpress printing plate 30 are:
L=(D+2t)π/n
WL≦AL
It is expressed as

FIG. 6 is a state diagram illustrating a joined state near the joint portion 39 of a first modification of the resin letterpress printing plate 30A wound around the plate cylinder 35. As shown in FIG.
Similar to the resin letterpress printing plate 30 shown in the first embodiment, this resin letterpress printing plate 30A has an image area 33 on the plate surface in the central region, and marginal zones 34 on both sides of the image area 33. It will be done. When the resin letterpress printing plate 30A is wrapped around the plate cylinder 35 via the double-sided adhesive tape 36, one end (front end) 37 side of the image area 33 and the other end (rear end) side of the image area 33 38 are butted against each other to form a joint portion 39.

The marginal zone 34 has a triangular cutout recess 40A formed on the outside of one end (front end), and the other end (rear end) of the marginal zone integrally protrudes outward in a triangular shape. A convex portion 41A is formed. A joint portion 44 is provided in which the concave portion 40A and the convex portion 41A of the marginal zone 34 are brought into contact with each other and joined. In the joint portion 44A of the marginal zone 34, the concave portion 40A and the convex portion 41A are formed in complementary shapes to each other, and the concave portion 40A of the marginal zone 34 is butted against and fitted into the convex portion 41A, so that the concave portion 40A and the convex portion 41A are complementary to each other. .

The joint portion 44A of the marginal zone 34 is not linearly aligned in the width direction of the seam portion 39 of the resin letterpress printing plate 30A. The joint portion 44A of the marginal zone 34 extends from the seam portion 39 and is shifted in the direction of rotation of the plate cylinder. Therefore, the joint portion 44A of the marginal zone 34 has no step extending in the width direction of the marginal zone 34, and forms a guide surface of a non-step portion continuous with the marginal zone 34.

FIG. 7 is a state diagram illustrating a joint state near a joint portion 39 showing a second modification of the resin letterpress printing plate 30B wound around the plate cylinder 35. As shown in FIG.
Similar to the resin letterpress printing plate 30 shown in the first embodiment, this resin letterpress printing plate 30B has an image area 33 on the plate surface in the central area, and marginal zones 34 on both sides of the image area 33. It will be done. When the resin letterpress printing plate 30B is wrapped around the plate cylinder 35 via the double-sided adhesive tape 36, one end (front end) 37 side of the image area 33 and the other end (rear end) side 38 of the image area 33 are wrapped. are butted against each other to form a joint portion 39.

The marginal zone 34 is configured with a recess 40B having a rectangular cutout on the outside on one end (front end) side, and the other end (rear end) side of the marginal zone 34 integrally protrudes outward in a rectangular shape. A convex portion 41B is formed. A joint portion 44B is provided in which the concave portion 40B and the convex portion 41B of the marginal zone 34 are brought into contact with each other and joined. In the joint portion 44B of the marginal zone 34, the concave portion 40B and the convex portion 41B are formed in complementary shapes to each other. The concave portion 40B of the marginal zone 34 is butted against the convex portion 41B thereof, and is fitted into the concave portion 40B so as to be complementary to each other.

The joint portion 44B of the marginal zone 34 is not linearly aligned in the width direction of the seam portion 39 of the resin letterpress printing plate 30B. The joint portion 44B of the marginal zone 34 extends from the seam portion 39 and is shifted in the direction of rotation of the plate cylinder. Therefore, the joint portion 44B of the marginal zone 34 does not have a step extending in the width direction, and forms a guide surface of a non-step portion continuous to the marginal zone 34 in the circumferential direction.

FIG. 8 is a state diagram illustrating a joint state near the joint portion 39 showing a third modification of the resin letterpress printing plate 30C wound around the plate cylinder 35.
Similar to the resin letterpress printing plate 30 shown in the first embodiment, this resin letterpress printing plate 30C has an image area 33 on the plate surface in the central region, and marginal zones 34 on both sides of the image area 33. It will be done. When the resin letterpress printing plate 30C is wrapped around the plate cylinder 35 via the double-sided adhesive tape 36, one end (front end) 37 side of the image area 33 and the other end (rear end) side of the image area 33 38 are butted against each other to form a joint portion 39.

The marginal zone 34 has a concave portion 40C formed with a step-shaped notch on the outside on one end (tip) side, and a convex portion 40C that protrudes integrally in the shape of a reverse step on the other end (rear end) side of the marginal zone. A section 41C is configured. A joint portion 44 is provided in which the concave portion 40C and the convex portion 41C of the marginal zone 34 are brought into contact with each other and joined. In the joint 44C of the marginal zone 34, the concave part 40C and the convex part 41C are formed in mutually complementary shapes, and the concave part 40C of the marginal zone 34 is butted against and fitted into the convex part 41C, so that they are configured in a mutually complementary relationship. .

The joint portion 44C of the marginal zone 34 is not linearly aligned in the width direction of the seam portion 39 of the resin letterpress printing plate 30C. The joint portion 44C of the marginal zone 34 extends from the seam portion 39 in the direction of rotation of the plate cylinder and is shifted. Therefore, the joint portion 44C of the marginal zone 34 constitutes a guide surface of a non-stepped portion that is continuous with the marginal zone 34.

As the photosensitive resin plate material 10, three types of plate materials 10 (10A, 10B, 10C) manufactured by Toyobo Co., Ltd. under the trade name Cosmolite QS114U, QS170F, and QS284F are used to produce a resin letterpress printing plate for flexographic printing. An example of manufacturing 30 will be explained. Measured data of an example of the relation between the relief depth and the thickness dimension of the floor layer and the back deposited layer of the manufactured resin letterpress printing plate 30 are shown in FIGS. 9 to 11, respectively. Here, the floor layer refers to the laminated portion of the resin relief printing plate 30 from the base film 11 to the back deposit layer 23, and the layer thickness of the floor layer is determined to maintain the physical, mechanical, and chemical strength of the resin relief printing plate 30. is important.

(1) Figure 9 is a measurement data diagram showing the relationship between the relief depth, floor layer, and back deposited layer thickness of a resin letterpress printing plate 30A manufactured from a rubber-based photosensitive resin plate material 10A of Cosmolite QS114U. It is. This plate material 10A is a CTP plate material for flexographic printing with a plate thickness of 1.14 mm, a plate size of 900 mm x 1200 mm, and a Shore A hardness of 81 degrees. The thickness dimensions of this CTP plate material are as follows: the base film 11 has a base thickness of 125 μm, the adhesive layer 12 has a layer thickness of 20 μm, the photosensitive resin plate layer 13 has a layer thickness of 995 μm, the ablation mask 14 has a thickness of 2 μm, and the cover has a thickness of 2 μm. The film 15 is a flexo plate material 10A with a cover thickness of 100 μm.

The flexo plate material 10A was irradiated with relief exposure (main exposure) with a light amount of 13,000 mj/cm ² from an active light source in the exposure process, and in the back exposure, the light amount was varied from 374 mj/cm ² to 9781 mj/cm ² . . UV light from an ultraviolet source was used for relief exposure and back exposure. The plate material 10A of the photosensitive resin plate that has been exposed to relief exposure and back exposure in the exposure process is then washed with water in the cleaning process by spraying a cleaning liquid and cleaning the cleaning brush 25 by rotating the cleaning brush unit. It will be done. By this water washing, the uncured resin material of the photosensitive resin layer 13 of the plate material 10A is removed from the cured portions (relief image 22, back deposited layer 23). The resin letterpress printing plate 30 obtained from the flexo plate material 10A from which the uncured resin material has been removed is surface-cleaned by a required rinse to remove foreign matter such as dust, and then dried to remove the resin letterpress printing plate 30. is dried, sticky material and the like are removed, and a resin letterpress printing plate 30 is manufactured.

FIG. 9 shows an example of the relationship between the relief depth, the floor layer, and the thickness of the back deposited layer of a resin letterpress printing plate 30 manufactured from the photosensitive resin plate material 10A by varying the amount of back exposure in the exposure process. This is a list. From this list, No. 5~No. According to the measurement results of No. 12, the relief depth of the resin letterpress printing plate 30 is as shallow as 62 μm or less. When a resin letterpress printing plate 30 with a relief depth of 62 μm or less is attached to the plate cylinder of a flexographic printing device and printed, the height (relief depth) of the relief image 22 of the resin letterpress printing plate 30 is low, so the printing material is This is undesirable as it may cause background stains. Therefore, the relief depth of the relief image 22 is required to be 110 μm or more, preferably 300 μm to 400 μm or more, taking into account the roughness of the plate surface of the resin relief printing plate 30 and the precision of the plate cylinder and impression cylinder. This resin letterpress printing plate 30 can provide a resin letterpress printing plate 30 suitable for flexible packaging films such as plastic films, envelopes, cartons, tags, and labels.

(2) FIG. 10 is a measurement data diagram showing the relationship between the relief depth, floor layer, and back deposited layer thickness of the resin letterpress printing plate 30 manufactured from the rubber-based photosensitive resin plate material 10B of Cosmolite QS170F. be. This plate material 10B is a CTP plate material for flexo printing, and has a size of 900 mm x 1200 mm and a Shore A hardness of 77 degrees. The thickness dimensions of the CTP plate material are as follows: the base film 11 has a base thickness of 125 μm, the adhesive layer 12 has a layer thickness of 20 μm, the photosensitive resin plate layer 13 has a layer thickness of 1555 μm, the ablation mask 14 has a thickness of 2 μm, and the cover film has a thickness of 2 μm. 15 is a flexo plate material 10B having a cover thickness of 100 μm.

The plate material 10B of the photosensitive resin plate is irradiated with relief exposure (main exposure) with a light amount of 13,000 mj/cm ² for example from an ultraviolet light source as an active light source in the exposure process, and a light amount of 374 mj/cm ² to 9781 mj/cm in the back exposure. ² and irradiation was performed with various changes. The plate material 10B of the photosensitive resin plate, which has been exposed through relief exposure and back exposure in the exposure process, is then sent to a cleaning process, and in this cleaning process, the cleaning liquid is sprayed and the cleaning brush of the cleaning brush unit is rotated. Water cleaning is performed by brush cleaning. By this water washing, the uncured resin material of the photosensitive resin layer 13 of the plate material 10B is removed from the cured portion (relief image 22 and back deposited layer 23). A resin letterpress printing plate 30 is manufactured from the photosensitive resin plate material 10B from which the uncured resin material has been removed in the same manner as the flexographic plate material 10A.

FIG. 10 is a measurement data diagram showing an example of the relationship between the relief depth, the floor layer, and the thickness of the back deposited layer of the resin letterpress printing plate 30 manufactured from the plate material 10B of the photosensitive resin plate having a plate thickness of 1.70 mm. . From this list, even if the resin letterpress printing plate 30 is attached to a flexographic printing plate cylinder and flexographically printed, the relief depth of the relief image is 109 μm to 714 μm, so the exposure latitude is large and the quality is excellent. A resin letterpress printing plate 30 can be provided. The floor layer has a layer thickness of about 1 mm to 1.6 mm, and the back deposited layer 23 has a layer thickness of 841 μm to 1446 μm, so the relief image 22 can be sufficiently supported, and the physical and mechanical , a flexible resin letterpress printing plate 30 with chemical strength can be provided. The resin letterpress printing plate 30 can provide a printing plate suitable for printing packaging films such as plastic films, envelopes, cartons, and labels.

(3) Figure 11 is a measurement data diagram showing the relationship between the relief depth, floor layer, and back deposited layer thickness of a resin letterpress printing plate 10C manufactured from a rubber-based photosensitive resin plate material 10C of Cosmolite QS284F. be. This plate material 10C is a CTP plate material for flexographic printing, and has a size of 900 mm x 1200 mm and a Shore A hardness of 77 degrees. The thickness dimensions of the CTP plate material are as follows: the base film 11 has a base thickness of 125 mm, the adhesive layer 12 has a layer thickness of 20 μm, the photosensitive resin plate layer 13 has a layer thickness of 2695 μm, the ablation mask 14 has a thickness of 2 μm, and the cover film has a thickness of 2 μm. 15 is a flexo plate material 10C with a cover thickness of 100 μm.

The flexo plate material 10C is irradiated with relief exposure (main exposure) at a light amount of 13,000 mj/cm ² from an ultraviolet light source as an active light source in the exposure process, and during back exposure, a UV light amount of 374 mj/cm ² to 9781 mj/cm ² is applied. Irradiation was performed with various changes. The photosensitive resin plate material 10C that has been exposed through relief exposure and back exposure in the exposure process is then sent to a cleaning process, and in this cleaning process, brush cleaning is performed by spraying a cleaning liquid and rotating the cleaning brush 25. Water washing is performed by this. By this water washing, the uncured resin material of the photosensitive resin layer 13 of the flexographic plate material 10C is removed from the cured portions (relief image 22 and back deposited layer 23). From the flexographic plate material 10C from which the uncured resin material has been removed, a resin letterpress printing plate 30 is manufactured in the same manner as the flexographic plate materials 10A and 10B.

FIG. 11 is a list showing an example of the relationship between the relief depth, the floor layer, and the thickness of the back deposited layer of the resin letterpress printing plate 30 manufactured from the plate material 10C, which is a flexo plate having a plate thickness of 2.84 mm. From this list, even if the resin letterpress printing plate 30 is attached to the plate cylinder of a flexographic printing device and flexographically printed, the relief image 22 has a height of 668 μm to 929 μm, and has a relief depth of 1 mm or less. Therefore, a printing plate with good printing durability, high exposure latitude, and excellent quality can be provided. Since the floor layer has a thickness of about 2 mm and the back deposit layer 23 has a layer thickness of 1766 μm to 2027 μm, the relief image 22 can be sufficiently supported by the back deposit layer 23, and physical, mechanical and chemical It is possible to provide a resin letterpress printing plate 30 with high mechanical strength.

By the way, the photosensitive resin plate materials 10 (10A, 10B, 10C) are rubber-based flexographic plates that have a higher exposure rate than the photosensitive resin plate materials (letterpress plate materials) described in Patent No. 5225327. It was discovered that a large amount of active light is required for relief exposure (main exposure) and back exposure in the process. For example, a flexo plate material with a plate thickness of 1.14 mm requires an energy amount of active light (UV light) of 13,000 mj/cm ² for relief exposure and 374 mj/cm ² to 4,559 mj/cm ² for back exposure. In rubber-based flexographic printing plates, in order to obtain the relief image 22 and back deposited layer 23 of the required height, the relief exposure is about 10 to 30 times that of the letterpress plate and the back exposure is about 10 to 70 times that of the letterpress plate. It was found that the amount of energy light is required.

Further, the photosensitive resin layer 13 of the rubber-based flexo plate material has rubber elasticity because it includes rubber components of synthetic rubber and liquid rubber. For this reason, in the case of flexographic plates, in order to remove uncured resin material from the cured areas (relief image 22 and back deposited layer 23) during the water development process, the cleaning brush 25 is pressed harder than in the case of letterpress plates. It is necessary to make a rotational movement and clean the brush. If the cleaning brush 25 is strongly pressed against the photosensitive resin plate layer 13 of the flexo plate material and the brush is cleaned by rotating the photosensitive resin plate layer 13 of the flexo plate material, the flexo plate material may slide sideways on the (magnetic material) conveyor belt. However, since the flexo plate material is fixed to the magnetic material conveyor belt by the magnetic force of the double-sided adhesive tape or the magnetic plate, it is possible to effectively and reliably prevent the flexo plate material from sliding sideways.

Further, FIGS. 9 to 11 show examples of resin letterpress printing plates 30 manufactured from three types of photosensitive resin plate materials 10A, 10B, and 10C with plate thicknesses of 1.14 mm, 1.70 mm, and 2.84 mm. showed that. Even if the plate material 10 of the photosensitive resin plate has a plate thickness of 3.00 mm or more, it is thought that the resin letterpress printing plate 30 can be manufactured in the same manner from a plate material with a plate thickness of about 10 mm.

Next, an embodiment in which a resin relief printing plate is applied to a flexo printing apparatus 50 will be described with reference to FIGS. 12 to 18.
The flexographic printing apparatus 50 (Flexographic Press) is roughly divided into three types of printing apparatuses 50A, 50B, and 50C: inline type, drum type, and stack type. The flexographic printing apparatus 50, regardless of the type of printing apparatus 50A, 50B, 50C, has four basic structures in common: a feeding section, a printing section, a drying section, and a winding section. In particular, a major feature of the flexo printing apparatus 50 is the printing unit 51 (51A, 51B, 51C) of the printing section.

In the in-line flexographic printing apparatus 50A (50), a plurality of printing units 51, for example, four to eight printing units 51, are arranged at linear intervals between a feeding roller 52 and a winding roller 53, and each printing Drying units 54 are provided downstream of the units 51, respectively. In the printing section, a printing cylinder 55 and an independent impression cylinder 56 are opposed to each other for each printing unit 51, and a printing medium 57, which is a continuous web or continuous form printing medium fed out from a feeding roller 52, is connected to a printing plate. It is passed between cylinder 55 and impression cylinder 56 for printing. The printed material 57 printed by the printing unit 51 is heated to 50° C. to 120° C. by a heater or the like when passing through the drying unit 54 on the downstream side of the printing unit 51 and is dried. The flexo printing apparatus 50A is sequentially guided to the next stage printing unit 51 and drying unit 54, and is finally wound up by the winding roller 53.

Furthermore, each printing unit 51 of the printing section is composed of an inking mechanism 58 that supplies ink to the resin letterpress printing plate 30 of the plate cylinder 55, and a plate cylinder 55 and an impression cylinder 56, as shown in FIG. Ru. The inking mechanism 58 has an ink tray 60 that stores flexo ink 59, a fountain roll 61 that is an ink feed roll that sends the stored ink, and an anilox roll 62 that is an ink transfer roll, and is a two-roll type inking mechanism. It is 58. Flexo ink 59 of various colors is stored in the ink tray 60 of each printing unit 51, and the ink supplied to the anilox roll 62 via the fountain roll 61 of the inking mechanism 58 is uniformly distributed over the plate surface of the plate cylinder 55. be transposed to. Control of the ink film in the two-roll type inking mechanism 58 is adjusted by the number of engraving lines, engraving depth, and cell shape of the anilox roll 62, while ink supply is controlled by the nip pressure between the fountain roll 61 and the anilox roll 62. The amount is regulated and controlled.

By the way, since the in-line flexographic printing apparatus 50A can ensure a sufficient distance between each printing unit 51 (intercolor distance), it is easy to incorporate the drying unit 54, and the drying efficiency of the printing material 57 can be improved. can be kept. In addition, each printing unit 51 has a plate cylinder 55 and an impression cylinder 56 each forming a pair, and the plate cylinder 55 has a resin letterpress printing plate 30 wrapped around the hollow plate cylinder 35 via a double-sided adhesive tape 36. , to be installed. The resin letterpress printing plate 30 wound around the hollow plate cylinder 35 is a printing plate having the shape shown in FIG. 3 .

Furthermore, when a single resin letterpress printing plate 30 is wound around the plate cylinder 35, as shown in FIGS. 3 and 13, one end (front end) side and the other end (rear end) The joint portion 39 where the two sides are butted is located on the tip side of the joint portion 44 of the marginal zone 34. The joint portions 44 of the marginal zone 34 are not aligned in the width direction of the seam portion 44, but are shifted in the rotational direction. A widthwise seam 46 where the front end concave portion 40 and rear end convex portion 41 of the marginal zone 34 abut against each other is a widthwise seam located on the rear end side of the joint portion 44 in the rotational direction. The joint 44 of the marginal zone 34 extends backward in the rotational direction from the seam 39 of the resin letterpress printing plate 30, and the marginal zone 34 and its joint 44 have no stepped portion extending in the width direction of the joint 44. , constitutes a guide surface of a non-stepped portion without a stepped portion in the rotational direction of the plate cylinder 51.

The joint portion 44 of the marginal zone 34 forms a smooth guide surface whose tip is continuous with the convex portion 44 on the rear end side of the marginal zone 34, and the rear end side of the marginal zone 34 forms a concave portion 44 on the tip side. The inner side (that is, the side of the image portion 33) constitutes a continuous and smooth guide surface. Therefore, the joint portion 44 of the marginal zone 34 has no step extending in the width direction, and the marginal zone 34 has no step in the circumferential direction due to the concave-convex joint where the concave portion 40 and the convex portion 41 of the marginal zone 34 are butted against each other. It constitutes the guide surface of the non-stepped portion.

Therefore, when a single resin letterpress printing plate 30 is wound around the hollow plate cylinder 35, even if a step is formed at the joint portion 39 of the resin letterpress printing plate 30, the marginal zone 34 and its joint portion 44 are The step of the joint portion 39 is absorbed, and a guide surface of a non-step portion is formed in the circumferential direction.

The printing material 57, which is a printing medium (printing base material), is passed between the plate cylinder 55 and the impression cylinder 56, and its travel is guided, so that even if there is a step at the seam 39 of the resin letterpress printing plate 30, the printing plate 57 The cylinder 55 cooperates with the impression cylinder 56 and rotates smoothly and smoothly without bounding (dancing) or rattling.

As the printing cylinder 55 and impression cylinder 56 rotate, the printing material 57 passed between the printing cylinder 55 and the impression cylinder 56 is removed from the anilox roll 62 of the inking mechanism 58 as shown in FIGS. 13 and 14. The transferred flexo ink 59 is transferred to the printing material 57 and printed. At this time, the plate surface of the plate cylinder 55 (of the resin letterpress printing plate 30) is printed by a kiss press under the condition that the indentation amount of printing pressure is about 10 μm to 100 μm.
A printing material 57, which is a printing medium, is held between a plate cylinder 55 and an impression cylinder 56, and its travel is guided. Each time the plate cylinder 55 rotates, the printing material 57 passes through the joints and joints 44 of the resin letterpress printing plates 30.

However, in the plate cylinder 55 of the flexographic printing apparatus 50 in which the resin letterpress printing plate 30 is wound around the plate cylinder cylinder 35 shown in FIG. The printed material 57 is guided at a printing speed of 100 to 300 m/min, and even when printing is performed on the printed material 57, the plate cylinder 55 is guided by the marginal zone 34 of the resin letterpress printing plate 30 and the joint portion 44 thereof, and the print cylinder 55 is smoothly guided. be rotated. The joint 44 of the marginal zone 34 is provided with a guide surface extending in the rotational direction (longitudinal direction) from the seam 44 of the resin letterpress printing plate 30. There is no step that aligns linearly with the portion 39 in the width direction or aligns with the seam portion 39 and extends linearly in the width direction. The joint portion 44 of the marginal zone 34 constitutes a guide surface of a non-step portion having no step in the circumferential direction of the plate cylinder 55. Therefore, even if there is a step at the seam 39 of the resin letterpress printing plate 30, the plate cylinder 55 rotates smoothly on the guide surface of the marginal zone 34 with no step in the circumferential direction and the non-step portion of the joint 44. You will be guided smoothly. The print material 57 passed between the plate cylinder 55 and the impression cylinder 56 is printed with the pressing force (printing force) of a kiss press, so that good printing quality can be achieved.

Further, a plate cylinder 48A configured by wrapping a plurality of, for example, two resin letterpress printing plates 30 around a hollow plate cylinder cylinder 35 is shown in FIG. 4(B). When this plate cylinder 48A is installed in the flexo printing apparatus 50, the plate cylinder 48A has a step at the seam 39 of the resin letterpress printing plate 30, similarly to the plate cylinder 48 (55) shown in FIG. 4(A). Even if there is, there is no step in the joint 44 of the marginal zone 34 that aligns with the seam 39 of the resin letterpress printing plate 30 and extends linearly in the width direction. The rotation of the plate cylinder 48A is guided smoothly and without rattling by the guide surfaces of the non-step portions of the marginal zone 34 and the joint portion 44 thereof. Therefore, the plate cylinder 48A can smoothly print on the printing material 57 passed between it and the impression cylinder 56 shown in FIG. 13 by the contact pressure of the kiss press, and can give good printing quality to the printing material.

FIG. 14 is a schematic configuration diagram showing a drum-type flexo printing apparatus 50B. In describing this drum type flexographic printing apparatus 50B, the same components as the inline type flexographic printing apparatus 50A shown in FIG. 12 are denoted by the same reference numerals, and repeated explanations will be omitted or simplified. The drum-type flexographic printing apparatus 50B has a plurality of printing units 51A, for example, four to eight printing units, arranged at intervals around a large central impression cylinder 65 that is a single cylinder or a joint impression cylinder. A drying unit 54A is arranged downstream of each printing unit 51A. The printing material 57 is moved along the impression cylinder 65, printed with flexo ink 59 of the printing unit 51A, and dried by heating with the heater of the drying unit 54A. The inking mechanism 58 of the printing unit 51A is of a two-roll type as shown in FIG. 15, and the printing material 57 is smoothly and smoothly printed in the same way as the printing unit 51 shown in FIG. 13.

The printing medium 57 fed out from the roll of the feeding roller 52 is guided by a guide roller 66 and sent to an impression cylinder 65 which is a single-cylinder drum. The printing material 57 is then run around the impression cylinder 65 and is sequentially printed by each printing unit 51A, while being heated and dried by a drying unit 54A on the downstream side of the printing unit 51A. The printing material 57 that travels along the impression cylinder 65 is unlikely to expand, contract, or sag during printing by each printing unit 51A. Therefore, even if the printing material 57 is continuous foam paper or a thin and easily stretchable flexible packaging film, printing can be performed with high precision. Since the impression cylinder 65 is a large drum that serves as a co-impression cylinder, the printing material 57 can be printed with good registration accuracy.
The printing material 57 printed by each printing unit 51A of the drum type flexographic printing device 50B and dried by the drying unit 54A is sent to the winding roller 52 via a guide roller 66 and wound up.

Furthermore, although the printing unit 51A uses a two-roll type inking mechanism 58 in the example of the flexo printing apparatus 50 shown in FIGS. 14 and 15, in place of the two-roll type inking mechanism 58, A doctor blade type inking mechanism 58A shown in FIG. 1 may also be used. This doctor blade type inking mechanism 58A is provided around the impression cylinder 65 of the single drum type shown in FIG. 14 in place of the two roll type inking mechanism 58.

As shown in FIG. 16, the doctor blade type inking mechanism 58A has a doctor blade 68 made of resin such as nylon or steel that is in circumscribed contact with the anilox roll 62. The amount of flexographic ink 59 that is rolled up is adjusted and controlled. By adjusting and controlling the amount of ink with the doctor blade 68, even if there are differences in the printing speed of the plate cylinder 55 or ink viscosity, there is little difference in the amount of ink supplied, and a stable amount of ink can be supplied to the resin letterpress printing plate 30. can. In this way, the doctor blade type inking mechanism 58A can supply a stable amount of ink to the plate surface of the plate cylinder 55, so the flexo printing apparatus 50 using the printing unit 51B can stabilize the print quality of long run printing and process printing. can be done. This doctor blade type inking mechanism 58A may be used in an in-line flexo printing apparatus 50A shown in FIGS. 12 and 13.

Further, the drum-type flexo printing apparatus 50B uses a large-diameter impression cylinder 65 of a single cylinder type or a joint impression cylinder type, and the plate cylinders 55 of each printing unit 51A facing this impression cylinder 65 are shown in FIG. The same hollow structure as the plate cylinder 55 shown in FIG. 13 is used. As the resin letterpress printing plate 30 provided on the plate cylinder 55, a printing plate having a shape shown in FIG. 3 is used. For this purpose, the resin letterpress printing plate 30 shown in FIGS. 14 to 16 is wrapped around a hollow plate cylinder 35 via a double-sided adhesive tape 36 and fixed. The drum type flexographic printing device 50B is provided on the plate cylinder 55 of each printing unit 51A, 51B. Even if there is a level difference in the joint part 39 of the resin letterpress printing plate 30, the marginal zones 34 on both sides and the joint part 44 thereof have no level difference in the circumferential direction of the plate cylinder 55, as shown in FIGS. 15 and 16. This part constitutes the guide surface. Therefore, the plate cylinder 55 facing the large-diameter impression cylinder 65 is guided by the guide surface of the non-step portion and rotates smoothly and smoothly without bounding (dancing) or rattling.
FIG. 17 is a schematic configuration diagram showing a stack type flexo printing apparatus.
In describing this stack type flexographic printing apparatus 50C (50), the same components as the inline type flexographic printing apparatus 50A shown in FIG. 12 are given the same reference numerals, and repeated explanation will be omitted or simplified.

The stack type flexo printing apparatus 50C is configured such that a plurality of printing units, for example, 4 to 8 printing units 511C, are stacked in a stack. An independent plate cylinder 55 and impression cylinder 56 are provided facing each other for each printing unit 51C. A drying unit 54 is installed on the downstream side of each printing unit 51C. Since the distance between each printing unit 51C (distance between colors) can be made long, the drying unit 54 can be easily installed on the downstream side of each printing unit 51C, and the installation floor space can be reduced. There are advantages.

The stacked flexographic printing apparatus 50C is a standard printing apparatus of the flexographic printing apparatus 50, and each printing unit 51C is provided with an independent plate cylinder 55 and impression cylinder 56 for each printing unit. The printing unit 51C is configured as shown in FIG. 18, and similarly to the printing unit 51 shown in FIG. configured. In the printing unit 51C, flexographic ink 59 from an ink tray 60 is taken out by a fountain roll 61 and supplied to an anilox roll 62. Various inks 59 stored in the ink trays 60 of each printing unit 51C are uniformly supplied to the plate surface of the plate cylinder 55 from an anilox roll 62 via a fountain roll 61. The ink transferred to the resin relief printing plate 30 of the plate cylinder 55 is transferred to a printing material 57 passed between the plate cylinder 55 and the impression cylinder 56 by the printing pressure of a kiss press, and printed.

The printing material 57 printed with each color ink 61 of each printing unit 51C of the stack type flexographic printing apparatus 50C is dried in the drying unit 54 on the downstream side of each printing unit 51C, and then rolled through a guide roller 66. It is wound up by a take-up roller 13.

Also in this stack type flexo printing apparatus 50C, the plate cylinder 55 constituting each printing unit 51C is configured as shown in FIG. 18, and a single or plural resin letterpress printing plates 30 are wound around the plate cylinder cylinder 35. For this reason, like the plate cylinder 55 shown in FIG. (No) Guided by the guide surface of the non-step part. The plate cylinder 55 and the impression cylinder 56 are brought into contact with a printing material 57 which is passed between them in a kiss press to perform printing. The plate cylinder 55 allows the resin letterpress printing plate 30 to be guided by the marginal zones 34 on both sides and the joints 44 thereof, and rotates smoothly and smoothly without bounding (dancing) or rattling. Therefore, the printing material 57 is printed without blurring or shading due to bounding, so that printing with good print quality can be performed on the printing material, which is a printing medium.

In the flexo printing apparatus 50 (50A, 50B, 50C), each printing unit 51 (51A, 51B, 51C) prints using flexo ink 59 of various colors. The flexographic printing apparatus 50 is roughly divided into three types depending on the type of solvent: water-based, alcohol-based, and solvent-based, and a suitable one is used. Recently, there has been a trend to use water-based inks, which are superior in terms of fire safety, sanitary working environment, and environmental and safety aspects of printing media (printing materials) 57.

Furthermore, in the embodiments of the present invention, the resin letterpress printing plate is an example of a flexographic resin letterpress printing plate made from a flexo plate material of a photosensitive resin plate, but the photosensitive resin plate is a letterpress plate. It is also possible to use a letterpress resin letterpress printing plate made from material.

Furthermore, resin letterpress printing plates are not only single-type resin letterpress printing plates for flexo that are made into a rectangular shape, but also endless resin letterpress printing plates that are constructed by connecting multiple resin letterpress printing plates to form a long sheet. It may also be used as a resin letterpress printing plate for letterpress, which is constructed by connecting long (5 m to 7 m) resin letterpress printing plates.
In addition, in the embodiments of the present invention, an example has been described in which the resin letterpress printing plate is used as a plate cylinder of a flexo printing device, but the resin letterpress printing plate can also be used as a plate cylinder of a letterpress printing device.

10, 10A to 10C...Photosensitive resin plate material 11...Base film 12...Adhesive layer 13...Photosensitive resin layer 14...Ablation mask 15...Cover film 16...Frame base 18...Photosensitive resin letterpress printing plate 19 ... (transparent) film 20 ... active light source 22 ... relief image 23 ... back deposited layer 25 ... cleaning brush 26 ... dryer 30, 30A to 30C ... resin letterpress printing plate 33 ... image area 34 ... marginal zone 35 ... plate cylinder cylinder 36...Double-sided adhesive tape 37...One end (tip)
38...Other end (rear end)
39... Seam portion 40... Recessed portion 41 in the marginal zone... Convex portion 44 in the marginal zone... Joint portion 45... Width direction recessed portion 46... Width direction joint portion 48, 48(A) in the marginal zone... Plate cylinder 50, 50A to 50C... Flexo printing apparatus 51, 51A...printing unit 52...feeding roller 53...take-up roller 54, 54A...drying unit 55...plate cylinder 56...impression cylinder 57...printing material (printing medium)
58, 58A... Inking mechanism 59... Flexo ink 60... Ink tray 61... Fountain roll (ink feeding roll)
62...Anilox roll (ink transfer roll)
68...Doctor Blade

Claims (12)

A rectangular resin letterpress printing plate that is wrapped around a plate cylinder via a double-sided adhesive tape to form a plate cylinder,
A resin letterpress printing plate for performing printing by guiding a printing material between the plate cylinder and the impression cylinder,
A resin letterpress printing plate in which marginal zones are formed in the longitudinal direction on both sides of the image area in the central area,
A recess cut out in the longitudinal direction of the resin relief printing plate is formed only at one end of the marginal zone among one end portion of the resin relief printing plate, and a recessed portion cut out in the longitudinal direction of the resin relief printing plate is formed at one end portion of the resin relief printing plate, and A protrusion projecting in the longitudinal direction is formed only at the other end of the marginal zone,
When the resin relief printing plate is wound around the plate cylinder, one end of the image area of the one end of the resin relief printing plate is attached to the other end of the resin relief printing plate. The other ends of the drawing portions are butted against each other to form a seam in the width direction, and the concave portion at the one end of the marginal zone and the convex portion at the other end of the marginal zone are butted against each other to form a joint portion. is configured,
The joint portion of the marginal zone is not aligned in a straight line in the width direction of the joint portion of the resin relief printing plate, but extends from the joint portion so as to have components in the longitudinal direction and the width direction. Characteristic resin letterpress printing plate. an outer corner portion of the one end of the marginal zone is configured with a recess cut out in a rectangular, trapezoidal, triangular, or stepped shape in the longitudinal direction, and an outer corner portion of the other end of the marginal zone A convex portion having a complementary shape protruding in a rectangular, trapezoidal, triangular, or stepwise manner is configured in the longitudinal direction,
2. The resin relief printing plate according to claim 1 , wherein a joint is formed in which a concave portion at the one end of the marginal zone abuts against a convex portion at the other end of the marginal zone . In the resin letterpress printing plate according to claim 1 or 2, a plurality of the resin letterpress printing plates are prepared and wound in series around a plate cylinder via a double-sided adhesive tape,
Among the plurality of plastic letterpress printing plates, the one end of the subsequent plastic letterpress printing plate is butted against the other end of the preceding plastic letterpress printing plate and joined sequentially, and the final resin letterpress printing is performed. A resin letterpress printing plate, characterized in that the one end portion of the foremost resin letterpress printing plate is butted against and joined to the other end portion of the plate. an exposure step of irradiating a rectangular photosensitive resin plate with energy light of a required wavelength from an active light source to form a relief image and a back deposit layer on the photosensitive resin layer of the plate;
The exposed plate material is conveyed to a cleaning device, and this cleaning device sprays a cleaning liquid onto the photosensitive resin layer of the plate material and performs brush cleaning by sliding a cleaning brush to remove unused material from the photosensitive resin layer. a water washing step to remove the hardened resin material;
and a cutting step of cutting the resin letterpress printing plate into a desired shape after removing the uncured resin material,
In a method for manufacturing a resin letterpress printing plate in which marginal zones are formed on both sides of the image area in the central area,
A concave portion is formed by notching in the longitudinal direction of the resin relief printing plate only at one end of the marginal zone among one end portion of the resin relief printing plate, and a concave portion is formed in the other end portion of the resin relief printing plate. A convex portion is formed by protruding in the longitudinal direction only at the other end of the marginal zone,
When the resin letterpress printing plate is mounted to be wound around a plate cylinder, one end of the image area of the one end of the resin letterpress printing plate is attached to the image line of the other end of the resin letterpress printing plate. The other ends of the sections are butted against each other to form a joint in the width direction, and the concave portion of the one end of the marginal zone and the convex portion of the other end of the marginal zone are butted against each other to form a joint. ,
The joint portion of the marginal zone is not aligned linearly in the width direction of the seam portion of the resin relief printing plate, but is shifted from the seam portion so as to have components in the longitudinal direction and the width direction. Characteristic method for manufacturing resin letterpress printing plates. An outer corner of the one end of the marginal zone forms a recess in the longitudinal direction cut out in a rectangular, trapezoidal, triangular, or stepped shape, and an outer corner of the other end of the marginal zone The corner portion constitutes a convex portion of the complementary shape in the longitudinal direction that protrudes in a rectangular shape, trapezoidal shape, triangular shape, or step shape,
5. The method for manufacturing a resin relief printing plate according to claim 4 , wherein the concave portion at the one end of the marginal zone is butted against the convex portion at the other end of the marginal zone to form a joint. A resin letterpress printing plate in which a marginal zone is formed in the longitudinal direction on both sides of the image area;
a plate cylinder configured by wrapping the resin relief printing plate around a plate cylinder cylinder;
an impression cylinder provided opposite to the plate cylinder;
and a printing unit equipped with an inking mechanism that supplies ink to the resin letterpress printing plate of the plate cylinder,
In a printing device that prints on a printing material by passing the printing material between the printing cylinder and the impression cylinder of the printing unit,
A recess cut out in the longitudinal direction of the resin relief printing plate is formed only at one end of the marginal zone among one end portion of the resin relief printing plate, and a recessed portion cut out in the longitudinal direction of the resin relief printing plate is formed at one end portion of the resin relief printing plate, and A protrusion projecting in the longitudinal direction is formed only at the other end of the marginal zone,
When the resin letterpress printing plate is wound around the plate cylinder, one end of the image area of the one end of the resin letterpress printing plate and the one of the other end of the resin letterpress printing plate The other end of the drawing part is butted against each other to form a seam in the width direction, and the concave part of the one end of the marginal zone is butted with the convex part of the other end of the marginal zone. is configured,
The joint portion of the marginal zone is not aligned in a straight line in the width direction of the joint portion of the resin relief printing plate, but extends from the joint portion so as to have components in the longitudinal direction and the width direction. Characteristic printing device. The outer corner of the one end of the marginal zone is formed with a recess in the longitudinal direction in which a rectangular, trapezoidal , triangular, or step-shaped recess is formed, and the outer corner of the other end of the marginal zone is notched. A complementary-shaped convex portion having a corner portion having a rectangular shape, trapezoidal shape, triangular shape, or step shape and protruding in the longitudinal direction is configured,
When the resin letterpress printing plate is wound around the plate cylinder, the one end of the image area is butted against the other end of the image area to form a seam,
7. The printing apparatus according to claim 6, wherein a convex portion at the other end of the marginal zone is butted against a concave portion at the one end of the marginal zone to form a joint. The inking mechanism includes an ink tray that stores ink, an ink feed roll that sends the stored ink, and an ink transfer roll that controls the ink supply amount by a nip pressure with the ink feed roll,
7. The printing apparatus according to claim 6, wherein the ink supplied to the ink transfer roll is transferred to the plate surface of the resin letterpress printing plate of the plate cylinder. The inking mechanism includes an ink tray that stores ink, an ink transfer roll that is supplied with the stored ink, and a doctor blade that controls the amount of ink that is supplied to the ink transfer roll. 7. The printing apparatus according to claim 6, wherein the amount of ink supplied from the ink transfer roll to the plate surface of the plastic relief printing plate is controlled. The printing unit is an inline printing device in which a plurality of printing units are arranged linearly,
The printing device according to claim 6, wherein a drying unit is provided at an intercolor distance between the printing units. The printing unit is a drum-type printing device in which a plurality of printing units are arranged around a central common impression cylinder,
The printing device according to claim 6, wherein a drying unit is provided at an intercolor distance between the printing units. The printing unit is a stack type printing device in which a plurality of printing units are arranged in a stack,
The printing device according to claim 6, wherein a drying unit is provided at an intercolor distance between the printing units.

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