JP2009018547A - Flexographic plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the necessity of trial printing and to collate a document with a prepared plate material by an image. <P>SOLUTION: The plate material 1 having a relief layer 3A on a floor layer 3B at least and having a colored layer 4 on the relief layer 3A is formed. Projecting parts 8 whose top surfaces 8A form an image part are formed on the relief layer 3A and the colored layer 4 of the plate material 1. The projecting part top surfaces 8A, the relief layer 3A and the floor layer 3B are color-coded to be visually distinguishable. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a relief printing plate, and more particularly to a flexographic plate that eliminates the need for trial printing of a prepressed plate material and allows easy calibration of the prepressed plate.

  As a means for confirming whether a conventional plate-making plate reproduces a film or digital data as a document as it is, proof printing is generally performed. For example, if the plate-making plate is a flexographic plate used for printing on corrugated cardboard, a paste proofing machine equipped with a plate cylinder equipped with the plate-making flexographic plate and an impression cylinder placed opposite to the plate cylinder is used. Then, the ink is transferred to the plate, and the proof printing is performed by rotating the plate cylinder rotating in the opposite direction and the impression cylinder on which the proof paper is pasted. However, in such a trial printing method, it takes a considerable amount of time and labor to print one proof.

  When checking with this machine, it also serves as both a pattern check and a color check. For this reason, taking time to check the printing machine is used in the era of today's low-volume, high-mix, short delivery times. The situation itself is almost impossible in terms of cost and labor.

  In addition, as a method of performing trial printing using another printing machine dedicated to proof printing, there are a substantially rectangular mounting plate on which a large size plate can be mounted, and two opposing sides of the mounting plate. There has been known a test printing apparatus including a first guide rail attached substantially in parallel. This includes a pair of sliders fitted on the first guide rail, a second guide rail horizontally mounted on the pair of sliders, and a stamp support portion that is slidably provided through the second guide rail. And a stamp supported by the stamp support section. According to such an apparatus, ink is placed only on the printing portion of the plate, the paper affixed to the bottom surface of the stamp is moved to a place where the test is desired, and the stamp handle is slid vertically downward. The lower part of the bottom surface comes into contact with the plate, and a local test printing can be performed. As a result of trial printing, if you want to proofread, you can easily proof by wiping off a small amount of ink on the plate and placing another ink on the same place, and the entire paper is also trial printed repeatedly. Since it is possible to save the trial printing locally rather than to reduce the cost. In addition, since a mounting plate on which a large-size plate can be mounted is provided, even a large plate material used for cardboard printing can be mounted (see Patent Document 1).

  Even if an apparatus such as that described in Patent Document 1 is used, it takes time for trial printing, and it is necessary to clean the ink adhering to the plate after printing, and the cost reduction effect is low. It was. In addition, since it is mainly to visually check the test prints, differences in letters, numbers, and missing fine parts are often overlooked, resulting in discovery in the final market, which is a big problem. . The number of such cases is one to two per year for a single company, but the number of cases discovered after the final printing is about one to two per month to some extent. When an inspection mistake occurs, there are many cases where the loss of time, material loss, loss of press operating rate, loss of all labor costs involved, and the cost of the mistakes are huge (milk cartons). Then, damages of tens of millions of yen are incurred with a single mistake). In particular, mistakes at the plate making stage are found only in the post-process, so a prior check is essential. However, the current proof printing process is omitted because it is very troublesome (because there are few cases that occur).

  Furthermore, an image inspection method in the plate making process was also developed. This is because if the original film that is the original does not match the print specification, a corrected original film is created, and the original original film image and the corrected original film image are read, Both images are compared to detect coincidence and inconsistency, and based on the detection result, the operator can determine whether or not the correction content is appropriate.

The image processing method described above uses the original film as a reference object, but uses the corrected original film as an object, and compares the reference object with the object, and thus has the following problems. In other words, since the film images of the reference object and the object are read and comparative inspections are performed, reading of these images causes slight reading errors such as small characters and slight differences in light and shade. It was often detected as a difference between the two. In addition, there are problems such as that it takes time to prepare an original film and reading the image, and it is necessary to prepare a film before and after correction, which increases costs. In view of this, an image inspection method in a plate making process has been developed that enables precise image inspection at a low cost in a short time. This is an image inspection method in a plate making process in which an image inspection is performed by comparing two image data generated at different stages of the plate making process, and the first digital image at a stage immediately before recording on an image recording medium. In this method, the image inspection is performed by comparing the data with the second digital image data obtained immediately before the first digital image data is corrected and recorded again on the image recording medium. (See Patent Document 2)
JP 2007-69492 A (page 3, FIG. 1) Japanese Laid-Open Patent Publication No. 10-104822 (page 4-5, FIG. 3)

  The one disclosed in Patent Document 2 is a proofreading based on image data of an original film, and not a proofreading based on image data as to whether or not a plate made from the original film is correctly made. Even in the case where the contents coincide with each other, the proofreading as to whether or not the plate material is made by reproducing the original film as it is still has to rely on proof printing as shown in Patent Document 1. For example, in the case of a flexographic plate using a photosensitive resin material, the unexposed resin is irradiated with ultraviolet light (UV light) to photopolymerize only the portion exposed to UV light, and then the unexposed portion is washed and removed. It is what you are trying. That is, the portion irradiated with light is solidified, the portion not irradiated with light is removed and processed into a relief plate. The plate thickness is thick from about 1 mm to about 9 mm, and the whole is formed of the same resin and the same pigment. To make a flexographic plate in which a photosensitive resin layer soluble in a developer is laminated on a support layer, actinic rays (for example, UV light) are irradiated through a negative mask and developed. Then, it was dried and post-exposure was performed as necessary to obtain a flexographic plate. Even if the surface of the flexographic plate made in this way is captured as image data, it is difficult to visually discriminate between an image portion and a non-image portion, and therefore only by proof printing.

  Therefore, the present invention makes it possible to clearly see the distinction between an image portion and a non-image portion when a plate-making flexographic plate is captured as image data, and there is a need for trial printing using a plate-making plate. It is another object of the present invention to provide a flexographic plate that can easily and quickly determine whether or not the plate matches the original by image processing.

  In order to achieve the above-mentioned object, the present invention forms a plate material having a relief layer on at least a floor layer and a colored layer on the relief layer, and the top surface is formed on the relief layer and the colored layer of the plate material. Forms a convex portion forming an image portion, and the top surface of the convex portion and the relief layer and the floor layer are color-coded so as to be visually distinguishable. The contrast of this color was set to be 0.3 or more in the reflection density difference.

  The present invention has a relief layer having a relief layer on at least the floor layer, and forming a plate material having a colored layer on the relief layer, and a convex portion whose top surface forms an image portion on the relief layer and the colored layer of the plate material. The top surface of the convex portion and the relief layer and the floor layer are color-coded so as to be visually distinguishable. For example, the data (original data) and the plate making to be a manuscript such as a plate making film captured in advance by a CCD scanner The obtained flexographic plate can be collated with data (plate making data) acquired by a CCD scanner, and whether or not the plate making data is reproduced can be easily and accurately performed without performing trial printing.

  Hereinafter, embodiments of the present invention will be described.

  In the cross-sectional view shown in FIG. 1, a resin plate 1 is composed of a base film layer 2, a photosensitive resin layer 3, a colored layer 4, a slip film layer 5, and a protection film layer 6. The colored layer 4 is also obtained by coloring the photosensitive resin layer (photopolymer). The color contrast between the colored layer 4 and the photosensitive resin layer 3 is 0.3 or more, more preferably 1.0 or more, as a reflection density difference. The case where the reflection density is 0.3 is the limit for distinguishing the contrast between the image and the non-image part. As a method for producing such a plate material 1, several methods can be adopted. For example, in the manufacturing process, two types of photosensitive resins having different dyes are manufactured by using a two-head extruder to manufacture the colored layer 4 and the photosensitive resin layer 3, and in the previous process of laminating the protection film layer 6, A method of dyeing the surface of the photosensitive resin with a dye to form a two-layer structure, a dyeing layer is provided between the slip film layer 5 and the photosensitive resin layer 3 and the protection film layer 6 is bonded, A method of dyeing the surface of the photosensitive resin, a method of making the surface of the plate material 1 (ink receiving image portion) mat-like (no transparency), and contrasting with a transparent portion of a non-image portion, and a very high depth of focus. There is a method that uses a narrow lens system, focuses only on the image portion, reads the image portion and the non-image portion with clear contrast, and reads only the image of the surface of the plate 1 with a CCD scanner.

  In the printing plate 1 shown in FIG. 1, the protection film layer 6 is peeled off, and, for example, an original film (negative film) 7 serving as a document is overlaid on the slip film layer 5, and this film 7 is irradiated with UV light for 10 to 20 minutes. (See FIG. 2). The upper part (relief layer 3A) of the photosensitive resin layer 3 exposed to UV light and the colored layer 4 are photopolymerized. Thereafter, the unexposed portions of the colored layer 4 and the relief layer 3A are washed and removed to make the flexographic plate 10. (See FIG. 3). Convex portions 8 are formed on the relief layer 3 </ b> A, and ink is deposited on the top surface 8 </ b> A of the convex portions 8. The top surface 8A of these convex portions 8 becomes an image portion, and the other layers become non-image portions. In addition, before the process shown in FIG. 2, UV light is irradiated from the base film layer 2 side, and the lower part of the photosensitive resin layer 3 is photopolymerized to form the floor layer 3B. The thickness of the floor layer 3B can be arbitrarily set by adjusting the exposure time according to the printing conditions. The prepolymerized floor layer 3B is not photopolymerized by irradiation with UV light in FIG. The protection film layer 6 protects the photosensitive resin layer 3 and is peeled off immediately before the negative film 7 is brought into close contact therewith. The slip film layer 6 is made of a thin film that dissolves in the developer between the negative film 7 and the resin layer because the entire resin of the photosensitive resin layer 3 is sticky, and improves the reproducibility of the latent image. Is.

  The colored layer 4 has a thickness of 2 to 200 μm, preferably 10 to 30 μm. The dye to be colored should not be severely discolored or discolored in the plate making process. Moreover, as a dye used for it, although it changes with plate making methods, a cationic dye, a procion dye, a remazole dye, and an acetate dye are especially suitable.

  The photosensitive resin for forming the relief layer 3 is formed of a photosensitive resin composition mainly composed of a polymer compound, an addition-polymerizable ethylenically unsaturated monomer, and a photopolymerization initiator. For example, isoprene, polybutadiene, styrene butadiene copolymer, styrene-isoprene copolymer, acrylonitrile-butadiene copolymer, chloroprene polymer, polyurethane or other synthetic rubber or natural rubber rubber having high elasticity. Examples thereof include molecular compounds. In addition, examples of the addition polymerizable ethylenically unsaturated monomer include acrylic acid, methacrylic acid, and esters thereof. Furthermore, as a photopolymerization initiator, benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin such as α-methylbenzoin, α-ethylbenzoin, α-allylbenzoin, benzophenone, ω -Various polymerization initiators such as phenone series such as promoacetophenone and acetophenone, and anthraquinone series such as anthraquinone, chloroanthraquinone, methylanthraquinone, and ethylanthraquinone.

  FIG. 4 is a cross section of the plate material 1 showing an example in which the surface of the photosensitive resin layer 3 is dyed with a dye as described above. In this example, a colored layer 4 relief layer 3A and a floor layer 3B are formed from the photosensitive resin layer 3. FIG. 5 is a diagram in which the convex portion 8 is formed by irradiating the negative film 7 with UV light and then cleaning and removing the negative film 7.

  6 and 7 show an example in which the mat-like portion 40 is formed instead of the colored layer 4 as described above. In this example, the mat-like portion 40 is not colored, but is formed in a non-transparent portion, and the relief layer 3A and the floor layer 3B are transparent so that they can be distinguished by their contrast.

  The flexographic plate made as described above is input as an image by a CCD scanner and stored in a computer as 1-bit-tiff data. Further, the original (original) data (digital data) is stored in the computer as 1-bit-tiff data in advance, and the reproducibility is confirmed by comparing with the data of the flexographic plate (plate data) made. In this case, the original data is digital data. However, as the original data, the original film is input as an image with a CCD scanner, stored as analog data (1 bit-tiff data), and collated with the original data (analog data). You can also. The resolution of the CCD scanner used here is sufficient at least 200 dpi to 400 dpi in the case of a line drawing. However, if the number of halftone lines of the plate is 200 lines / inch, a resolution of 1000 dpi is required, but if the resolution becomes high, the processing capability of the computer (PC) becomes a problem, so it is desirable to process at the minimum resolution. . The recommended software is Hallmarker (GTB), the OS is Windows (registered trademark) XP Professional, and the memory size is 4 GByte memory.

When the original plate data is digital data and the plate data is a line drawing pattern in which the plate size is 500 mm square and the character series is a minimum of 3 in the collation with the analog data of the plate data, the time required for proofreading the plate material is: It was as follows. That is,
・ Reading time by CCD scanner (200 dpi resolution) is about 1 minute from plate setting to reading completion.
-The collation time with the digital data is about 1 minute, 2 minutes in total, and the disagreement (the digital data is not reproduced) is arbitrarily displayed in color on the monitor.

If the plate-making plate was proof printed with a conventional printing machine, the time required for proofreading was as follows. That is,
・ About 5 minutes to attach the plate to the cylinder of the printing machine using double-sided tape, taking care not to embed the air ・ About 15 minutes to set up ink in the printing machine and get ready to print About 15 minutes to adjust printing pressure, ani pressure, etc., 1 minute to complete printing, about 20 minutes to inspect printed matter and manuscript (film, block, etc.), total 56 minutes, then other than above For this work, the ink adhering to the printed plate must be restored to a clean plate immediately after plate making by attaching a cleaner to a cloth or the like.

Next, in the collation of the same digital data and analog data as described above, when the plate size is a halftone dot pattern of 500 mm square and 150 lines, the time required for calibration of the plate-making plate material was as follows. . That is,
・ Reading time by CCD scanner is about 3 minutes (reading resolution is 800 dpi)
-The collation time with the digital data is about 3 minutes and 6 minutes in total, and the disagreement (not reproducing the digital data) is displayed in any color on the monitor.

The time required to calibrate the above-described plate material with a proof printing press was as follows.
・ The time required to print the proof print is 36 minutes in total, the same as the previous test print. ・ Approximately 30 minutes to inspect the original and the printed material. Total 66 minutes after that, the plate cleaning processing time is required to be equivalent to the previous test print. It is.

  FIG. 8 shows a procedure for collating, as an image, whether an image produced using the flexographic plate of the present invention is a reproduction of an original. As shown in FIG. 8, a flexographic plate is manufactured through the steps shown in FIGS. The image portion (the top surface 8A of the convex portion 8A, the colored layer 4) and the non-image portion (other layers) on the surface of the manufactured flexographic plate clearly show a difference in pigment or lightness and can be visually recognized. It has become. The surface of the flexographic plate (top surface 8A) is read by an image input scanner. Next, the original digital data (original data) is compared with the read image. If the verification result can be confirmed on the monitor and the original is faithfully reproduced, it can be shipped, and if there is a portion that is not reproduced, it is corrected or re-engraved by the plate making operation.

Sectional drawing of the plate material before the flexographic plate making of this invention. Sectional drawing of the state which adheres a negative film to a plate material and irradiates UV light. Sectional drawing of the flexographic printing plate made. Sectional drawing which shows the other example of a printing material. Sectional drawing of the flexographic plate made from the plate material of FIG. Sectional drawing which shows the further another example of plate material. Sectional drawing of the flexographic plate made from the plate material of FIG. The figure which shows the calibration procedure of the plate-making plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plate material 3 Photosensitive resin layer 3A Relief layer 4 Colored layer 4B Floor layer 8 Convex part 8A Top surface

Claims (3)

While having a relief layer on at least the floor layer, forming a plate material having a colored layer on the relief layer,
The relief surface and the colored layer of this plate material form a convex part where the top surface forms an image part,
A flexographic plate characterized in that the top surface of the convex portion and the relief layer and the floor layer are color-coded so as to be visually distinguishable.   The flexographic printing plate according to claim 1, wherein the color contrast between the colored layer and the other layer is 0.3 or more in reflection density.   The surface of the relief layer is formed in a mat-like portion instead of the colored layer according to claim 1 and is visually determined by the contrast between the non-transparency of the mat-like portion on the top surface of the convex portion and the transparency of the relief layer and the floor layer. A flexographic version characterized by distinction.

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