JP4117943B2 - Method for producing a printing plate having cushioning properties - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention is a method for producing a printing plate having a cushioning property suitable for use as a flexographic plate, by color printing a matrix image for forming a color filter on glass for a liquid crystal panel, or by color printing an image on a compact disk or the like. Regarding the method.
[0002]
[Prior art]
Conventionally, gravure offset printing or waterless offset printing has been used for color printing of matrix images for configuring color filters on printing plates, especially liquid crystal panel glass, or color printing of images on compact discs, etc. Gravure printing has not been adopted.
[ 0003 ]
The reason for this is that gravure printing is not cushioning, so if the printing pressure increases, it may break the glass or distort the compact disc, etc., so printing via a blanket roll made of rubber This is because, when the printing pressure increases, gravure offset printing that can suppress an increase in printing pressure by deformation of rubber is appropriate.
[ 0004 ]
For color printing on glass for liquid crystal panels, the thickness of the wet ink film immediately after transfer to the glass is set to a uniform 5-6 μm, and the dry ink film thickness is set to a uniform 1-1.5 μm. It is necessary to ensure uniform transmission and high transmittance.
[ 0005 ]
In addition, in order to print an image on a compact disk or the like, it is necessary to make the ink film thickness as thin as possible to the extent that the image can be obtained sharply. The reason is that the image printed on a compact disk or the like is printed with a bias with respect to the center, so the weight of the ink forming the image is the spindle that uses the fluid dynamic pressure bearing of the next generation compact disk device It was found that as the motor rotates faster, it can no longer be ignored as the cause of unbalanced rotation.
[ 0006 ]
In conventional gravure printing plates, it is necessary to form cells in the surface layer portion of copper plating so that the depth is 15 to 25 μm. Then, the film thickness of the wet ink is 15 to 25 μm. The film thickness of the ink is not suitable for color printing on glass or color printing of images on compact discs.
[ 0007 ]
In conventional gravure printing plates, the cells cannot be etched to a depth of 5-6 μm on the surface of the copper plating because the copper plating film has a crystalline structure and the etching process is not performed uniformly. is there. It is inevitable that the contour and bottom surface of the cell are uneven and that cells having different depths depending on the size are formed. Especially for cells with a large shadow part, even if the depth is 5 to 6 μm, for cells with a small highlight part, there is a high probability of irregularities on the contour and bottom, and the depth is reliably 5 to 6 μm. Can hardly get to.
[ 0008 ]
Therefore, in order to reliably obtain a gravure plate having a cell depth of 5 to 6 μm, it is possible to form a fairly accurate cell having a uniform depth by printing an image on alkali glass, developing and etching with hydrofluoric acid. it can. However, this is not gravure printing but gravure offset printing in which printing is performed via a blanket roll.
[ 0009 ]
Thus, conventionally, gravure offset printing or waterless flat printing plate offset printing has been adopted for color printing on glass for liquid crystal panels or color printing on compact discs, etc., and gravure printing has been adopted. I did not come.
[ 0010 ]
On the other hand, conventional flexographic plates (resin relief plates) are formed by applying a mask film on a photocurable resin and irradiating it with infrared light for etching, or by forming a carbon black film on the photocurable resin to form a positive photosensitive resin. A film is applied, a negative image is printed with a laser, developed, and then irradiated with infrared light and then etched to make a plate.
[ 0011 ]
[Problems to be solved by the invention]
However, the color filter for liquid crystal panels manufactured by the conventional printing method has low image sharpness, the edge of the line image is irregular, and the line image has irregularities. The quality is remarkably inferior to that of the above, and therefore, its use is widespread only for toys, and it is not used at all for luxury products such as computer displays and televisions.
[ 0012 ]
The reason for the poor quality of the color filter for liquid crystal panels produced by gravure offset printing is considered as follows.
In gravure offset printing, a printing pressure is applied to some extent when ink is transferred from a blanket roll to a substrate such as glass. Since the printing pressure presses the ink, the contour of the ink spreads outward or is disturbed, which is one of the reasons why the value of the line and space cannot be reduced. In addition, when the transferred ink does not transfer from the plate to the blanket roll and from the blanket roll to the printed material such as glass with a probability of 100%, the ink is torn off and printed on the printed material such as glass. The ink film thickness is not uniform and the surface is uneven.
[ 0013 ]
Research results have been published in the paper that the transferred ink can be transferred to a printed material such as glass with 100% probability.
According to this, a 0.1 μm silicon rubber film on a printing plate made of alkali glass is coated to give releasability, and light is irradiated when the photocurable ink is applied to the cell. The ink was transferred to the blanket roll from the plate with a probability of 100% by semi-drying the ink to make it difficult to break. Furthermore, the ink transferred to the blanket roll of silicon derivative was used for liquid crystal panels. Before printing on glass, irradiate the light once more to make the ink semi-dry and make it hard to break, and coat the surface of the liquid crystal panel glass with an acrylic adhesive with a thickness of 0.2 to 0.3 μm By doing so, the ink could be transferred from the blanket roll to the liquid crystal panel glass with a probability of 100%.
[ 0014 ]
However, in order to transfer the ink from the blanket roll to the liquid crystal panel glass with a probability of 100%, it is indispensable to manufacture a plate and a printing apparatus with high precision. That is, with the mechanical accuracy of a normal printing apparatus, it is inevitable that printing pressure is applied and fluctuates when ink is transferred from a blanket roll to glass for a liquid crystal panel. It is extremely difficult to increase the mechanical accuracy so that the printing pressure is completely eliminated or does not fluctuate at all.
[ 0015 ]
If the printing machine can be manufactured with high precision so that the gap between the blanket roll and the glass for the LCD panel is completely matched with the ink film thickness, and the gap dimension does not fluctuate during printing. The pressure is almost constant and does not fluctuate. However, it is almost impossible to put such a device into practical use.
[ 0016 ]
This is because when the gap between the blanket roll and the liquid crystal panel glass is maintained at, for example, 5.5 μm, and the 6 μm thick ink adhering to the blanket roll is transferred to the liquid crystal panel glass, the ink film thickness is Printing pressure is generated so as to be 5.5 μm. When the blanket roll rotates and when the liquid crystal panel glass is moved directly in line with the surface speed of the blanket roll, it is difficult to prevent the gap between the blanket roll and the liquid crystal panel glass from changing at all. It is. The blanket roll needs to be manufactured with high precision so as to be a perfect circle or a perfect cylinder, and the liquid crystal panel glass needs to be moved directly so that no wave motion is generated. Even if the diameter of the blanket roll has an eccentricity of 1 μm, or if the liquid crystal panel glass approaches or moves away from the blanket roll by 1 μm, the ink film thickness becomes 4.5 μm, and the printing pressure fluctuates. In addition, the gap between the blanket roll and the liquid crystal panel glass becomes larger than 5.5 μm, and at this time, the ink adhering to the blanket roll cannot be transferred to the liquid crystal panel glass.
[ 0017 ]
What can be said from this is that no matter how much the precision of the gravure offset printing machine is pursued, it is necessary to apply the printing pressure, and it is impossible to suppress the fluctuation of the printing pressure. Therefore, since it is essential that printing pressure is applied and the printing pressure fluctuates, it is very difficult to put it into practical use even if it is possible to transfer ink from the blanket roll to the liquid crystal panel glass with a probability of 100%. It is believed that there is.
[ 0018 ]
On the other hand, the conventional flexographic plate (resin relief plate) uses a photo-curing resin, so if a small dot is formed in a columnar shape, it easily breaks, and the brittleness of the cured resin cannot be eliminated. I couldn't make it.
[ 0019 ]
The invention of the present application has been devised in view of the above points, and by having a printing plate, in particular, cushioning properties, direct gravure printing can be performed on a hard substrate without using a blanket roll, and deep. The ability to form a cell with a small and smooth bottom and releasability enables color printing of matrix images for configuring color filters on glass for liquid crystal panels, or color printing of images on compact discs, etc. Or it aims at providing the manufacturing method of the printing plate which has a cushioning property suitable as a flexographic plate.
[ 0020 ]
[Means for Solving the Problems]
Present invention, a metal film is formed on a plate member made of a resin having rubber or cushioning, the resist image is formed on the surface of the metal film, the exposed portion of the metal film is removed by a metal film etching, and then, A method for producing a gravure printing plate having a cushioning property in which a cell is engraved in an exposed portion of the plate material by etching a plate material , and then an image of the metal film is removed and then a DLC film is coated. there is provided a method of manufacturing a gravure printing plate having a cushioning property, wherein a copper plating film der Rukoto.
[ 0021 ]
In the present invention , a plate material made of a rubber having a uniform thickness or a resin having a cushioning property is wound around the surface of a roll-shaped plate base material so as not to open a gap at the seam to form the plate material. Is preferred .
[ 0022 ]
DETAILED DESCRIPTION OF THE INVENTION
A printing plate having cushioning properties according to an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, (a) is a cross-sectional view showing a printing plate material obtained by forming a plate material on a roll-shaped plate substrate and further forming a metal film on the surface of the plate material, and (b) is for a printing plate. Enlarged cross-sectional view of the plate material, (c) is an enlarged cross-sectional view showing a state in which a resist image is formed on the metal film on the surface of the printing plate material, and (d) is a state etched into the metal film of the printing plate material (E) is an enlarged cross-sectional view showing a state where the exposed portion of the plate base material of the printing plate is engraved, (f) is a cell in the exposed portion of the plate base material of the printing plate (G) is an expanded sectional view which shows the state which formed the DLC film after engraving the cell in the plate base material of the plate material for printing plates.
[ 0023 ]
Reference numeral 1 denotes a plate base material, reference numeral 2 denotes a plate material made of rubber or a resin having cushioning properties, reference numeral 3 denotes a metal film, reference numeral 4 denotes a resist image, reference numeral 5 denotes a cell, and reference numeral 6 denotes a DLC film.
[ 0024 ]
The method for producing a printing plate having cushioning properties according to this embodiment includes:
As shown in FIGS. 1 (a) and 1 (b), a flat plate substrate 1 made of aluminum (may be made of iron) having a hollow shape with holes to be chucked at both ends, whose outer surface is a perfect circle and precisely polished into a cylinder is also possible. Winding so that a gap is not opened at the seam, which is a plate made of a rubber having a uniform thickness of 5 to 10 cm (or 1 to 2 mm) or a resin having a high surface smoothness or a cushioning resin. A plate material 2 that is attached and bonded is provided, the chucked holes at both ends of the plate base material 1 are chucked at both ends, a surface treatment that allows electroless plating to adhere thereto is performed, and then immersed in an electroless plating solution and rotated. By forming a metal film (for example, copper plating) 3 made of electroless plating with a film thickness of several μm from the end face of the plate base 1 to the surface of the plate 2, a roll-shaped printing plate Constitute.
[ 0025 ]
Subsequently, as shown in FIG. 1C, the surface of the metal film (copper plating) 3 is activated, and then the photosensitive film is uniformly applied and dried, and then the image is directly printed by a laser exposure apparatus. Then, the image is printed by overlapping the film, and then developed and etched to form a resist image 4 to expose the metal film 3.
[ 0026 ]
Subsequently, as shown in FIG. 1 (d), the exposed portion of the metal film 3 is removed by etching to expose the plate material 2 made of the rubber or a resin having a cushioning property.
Subsequently, as shown in FIG. 1E, the resist image can be removed with a solvent (not necessarily removed at this stage), and the plate material 2 can be etched using the image of the metal film 3 as a mask. A cell 5 having a depth dimension of, for example, 2 to 4 μm is engraved in the exposed portion of the plate material 2 by wet etching by dipping in a solvent or by dry etching such as plasma etching.
[ 0027 ]
Subsequently, as shown in FIG. 1 (f), the image of the metal film 3 is removed and the plate 5 is formed with the cells 5 to form a printing plate.
Further, as shown in FIG. 1 (g), the DLC film is formed on the plate material 2 made of rubber having the cells 5 or resin having cushioning properties by a thin film forming technique such as plasma CVD or sputtering. Is, for example, a printing plate in a coated state so as to be 0.5 μm or less.
[ 0028 ]
The object of the method for producing a printing plate having cushioning properties according to this embodiment is as follows.
In addition to gravure printing plates, offset printing plates, flexographic printing plates, printing plates for producing color filters for liquid crystal panels, and the like are included. DLC is a diamond-like carbon = hard carbon compound, especially when producing gravure printing plates where the plate surface is worn by scraping off ink adhering to the non-image area of the plate surface with a doctor. It is necessary to obtain the number of sheets, and is not necessary when manufacturing other printing plates.
[ 0029 ]
The formation of the DLC film is a means for imparting printing durability to the plate surface, and the metal film 3 cannot be a means for imparting printing durability to the plate surface. The reason is that if the metal film 3 is copper-plated, there is no printing durability, but even if it is chrome plating, the metal film 3 remains only on the screen wire in the shadow portion, so that sufficient printing durability cannot be secured. It is.
[ 0030 ]
On the other hand, when the DLC film is formed on the plate material 2 in which the cell 5 is formed and the metal film 3 is removed, the DLC film covers not only the screen wire but also the surface of the cell 5, so that a large adhesion strength is secured. Because it can.
[ 0031 ]
The plate material 2 does not contain silicon rubber under normal conditions. The reason is that silicon rubber is extremely chemically stable, and at present there is no solvent that can dissolve silicon rubber, and it cannot be etched by plasma etching or the like.
[ 0032 ]
Since the printing plate 2 has cushioning properties, when the printing pressure is to be generated high due to the eccentric rotation of the roll, the printing material 2 is easily deformed by the printing pressure and the printing pressure increases. It plays the role of suppressing
[ 0033 ]
Since the printing plate according to the production method of the present invention has cushioning properties, it is suitable for color printing a matrix image for constituting a color filter on glass for a liquid crystal panel, or color printing an image on a compact disk or the like. It is.
[ 0034 ]
In particular, in the production of a printing plate for producing a color filter, the surface of the plate material 2 on which the cells 5 are formed is coated with a silicon derivative rubber that cures by deoxidation so that the film thickness becomes, for example, 0.1 μm. Thus, it is advantageous to make the oil-repellent property of the silicon derivative rubber function so that the release property of the cell 5 with respect to the ink is retained. In forming the DLC film, it is also advantageous to select a source gas that makes the DLC film function oil repellency.
[ 0035 ]
When this printing plate is brought into contact with glass and printed, the contact pressure tends to act as a printing pressure, but the contact pressure does not act in the cell 5 at all. Since the ink is transferred from the inside of the cell 5 to the glass, and there is no possibility that a large printing pressure is applied at that time, the outline of the ink does not spread outward or is not disturbed by the printing pressure.
[ 0036 ]
For this reason, the printing plate according to the present invention for performing color printing for manufacturing a color filter on glass for a liquid crystal panel is 6 μm when the pattern is accurately baked using a laser exposure apparatus. Line / space.
[ 0037 ]
Therefore, if the technique of color printing on the glass for liquid crystal panels is performed together with the UV ink applied to the cell 5 by the doctor and irradiating with UV light to make the UV ink semi-dry, the ink transfer from this printing plate to the glass Can be obtained with a probability of 100%, and the color filter can be manufactured at a much lower cost than the conventional photolithography method by the printing method using the printing plate according to the present invention.
[ 0038 ]
【The invention's effect】
As described above, according to the method for producing a printing plate having cushioning properties of the present invention,
A metal film is formed on a plate made of rubber or a resin having a cushioning property, a resist image is formed on the surface of the metal film, an exposed portion of the metal film is removed by etching, and then the etching is different from the above. Since the cell was engraved in the exposed part of the plate material, and then configured to remove the image of the metal film,
The printing plate can be cushioned, and direct gravure printing can be performed on a hard substrate without using a blanket roll. The matrix image for forming the color filter on the glass for a liquid crystal panel can be printed in color, or the image can be printed in color on a compact disk, or a flexographic plate.
[ 0039 ]
Further, when the DLC film is coated after removing the image of the metal film, it is more preferable because it has a printing durability in addition to having cushioning properties.
[ 0040 ]
Furthermore, on the surface of the roll-shaped plate base material, a plate material made of a rubber having a uniform thickness or a resin having cushioning properties is wound so as not to open a gap at the seam, and when the plate material is formed, It is more suitable as a mother roll or a flexographic printing roll for color printing a matrix image for constituting a color filter on glass for a liquid crystal panel.
[ 0041 ]
In this printing plate manufacturing method, in particular, when the cells 5 are formed by dry etching, a plate in which cells having a uniform depth are vertically carved from the plate surface can be obtained, and the film thickness of the ink accumulated in the cells. For thin gravure printing on compact discs, etc., the amount of ink transferred from the highlight area to the shadow area can be made completely proportional to the area of the cell, and from the highlight area to the shadow area. The gradation gradation can be changed linearly, and a sharp gravure image with a rich gradation gradation can be obtained.
[ 0042 ]
Then, when this printing plate is coated with a silicon derivative rubber having oil repellency on the surface of the chromium plating film having cells, a printing plate having uniform cells having a very shallow depth of releasability to ink can be obtained. Therefore, when direct printing on glass is performed using this printing plate, unlike gravure offset printing, the ink in the cell is not crushed by the printing pressure, and the transfer to the substrate can be ensured. It is possible to avoid the transfer of ink with a cross-sectionally piled state, which is a drawback in the production of color filters by the conventional printing method, printing with extremely thin and uniform ink thickness, sharp outlines, and less disturbance of the edge of the outline. This is suitable for color printing of a clear image with a very thin ink film on a compact disk or the like.
[ 0043 ]
In this printing plate, when a chrome plating film is shallowly formed to 4 to 6 μm, a photosensitive film is formed, a pattern is baked by a laser exposure apparatus to form cells on the surface of the chrome plating film, and an oil-repellent silicon derivative rubber is coated. A printing plate having 6 μm line and space and having cells having releasability to ink can be obtained. Therefore, an ink transfer rate of 100% can be obtained by using a technique in which the ink accumulated in the plate cell is irradiated with a UV light source to be semi-dried and then transferred.
[Brief description of the drawings]
FIG. 1 relates to a method of manufacturing a printing plate having cushioning properties according to an embodiment of the present invention. (A) forms a plate material on a roll-shaped plate base material, and further forms a metal film on the surface of the plate material. (B) is an enlarged cross-sectional view of the printing plate material, and (c) shows a state in which a resist image is formed on the metal film on the surface of the printing plate material. Enlarged cross-sectional view, (d) is an enlarged cross-sectional view showing a state in which the metal film of the printing plate is etched, (e) is an enlarged cross-sectional view showing a state in which the exposed portion of the printing plate is engraved. FIG. 5 (f) is an enlarged cross-sectional view showing a state in which the metal film is removed after engraving cells in the exposed portion of the plate base material of the printing plate, and (g) is the plate base material of the printing plate material. It is an expanded sectional view showing the state where a DLC film was formed after carving a cell.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Plate base material 2 ... Plate material 3 ... Metal film 4 ... Resist image 5 ... Cell 6 ... DLC film

Claims (2)

A metal film is formed on the plate material made of a resin having rubber or cushioning, the resist image is formed on the surface of the metal film, the exposed portion of the metal film is removed by a metal film etching, then, the plate material etching A method for producing a gravure printing plate having a cushioning property in which a cell is engraved in an exposed portion of the plate material, and then an image of the metal film is removed and then a DLC film is coated, wherein the metal film is a copper plating film method of manufacturing a gravure printing plate having a cushioning property characterized by Rukoto Oh.   A plate material made of rubber having a uniform thickness or a resin having a cushioning property is wound around a surface of a roll-shaped plate base material so as not to open a gap at a seam, thereby forming the plate material. Item 2. A method for producing a printing plate having cushioning properties according to Item 1.

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