JP5768443B2 - Pattern for gravure screen, gravure screen, and gravure version - Google Patents

Description

  The present invention relates to a gravure plate used for gravure printing, a gravure screen for producing the gravure plate, and a pattern used for the gravure screen.

  Gravure printing is a printing method in which ink clogged in minute recesses called cells formed on the cylindrical surface of a gravure plate is transferred to a printing substrate such as paper or plastic film by applying printing pressure.

  FIG. 1 schematically shows general gravure printing. A low-viscosity and fluid gravure ink is filled in an ink pan, and a cylindrical gravure plate is rotated so that a part thereof is immersed in the gravure ink.

  The gravure ink that adheres and rises on the cylindrical surface of the plate as the gravure plate rotates is scraped off by a doctor blade so that only the amount necessary for printing is left in the cell. Thereafter, a printing substrate (film, paper, etc.) is passed between the plate cylinder and the impression cylinder, and the gravure ink remaining in the cells is transferred to the printing substrate by the printing pressure between the plate cylinder and the impression cylinder. This is an outline of the gravure printing method.

A general gravure plate (corrosion method) is produced by the following process.
(1) An aluminum or iron cylinder roll is used as a base material, and the surface of the cylindrical portion is subjected to base copper plating.
(2) After the base copper plating, ballad copper plating is performed.
(3) After the ballad copper plating, grindstone polishing is performed.
(4) A photosensitive material is applied to the polished copper surface to form a photosensitive material layer.
(5) A pattern is drawn by exposing the photosensitive material layer with a laser exposure machine.
(6) Development is performed to remove the exposed portion of the photosensitive material layer. (The portion of the photosensitive material that was not exposed remains as a resist layer on the copper surface.)
(7) Immerse or spray in a corrosive solution made of cupric chloride or ferric chloride. In the portion without the resist layer, copper is corroded to form an intaglio (cell). The portion where the resist layer remains is not corroded, and a portion called “bank” is formed.
(8) Strip the resist layer.
(9) Perform chromium plating.
(10) Perform paper polishing.

When drawing a pattern in the above (5), an exposure pattern called a screen is predetermined and drawing is generally performed according to the pattern (see FIG. 2). In addition, as a conventional method, there is also a method in which a screen is pattern-printed on a positive film, and exposure is performed in a state where the positive film is wound around a gravure cylinder.
The shape of the screen to be drawn is generally a square lattice type as shown in FIG. (Reference numeral 1 in FIG. 3 indicates an exposed portion without a resist layer, and reference numeral 2 indicates a non-exposed portion where the resist layer remains.) In this case, the shape of the cell formed on the gravure plate is as shown in FIG. Become. FIG. 4 is a photograph obtained by image processing so that the gravure plate cells (concave portions) and the shape of the bank can be clearly seen. Reference numeral 3 in FIG. 4 is a part that has been corroded to become a cell, and reference numeral 4 is not corroded. The “bank” part.

  Further, Patent Documents 1 to 3 propose special screen shapes for the purpose of improving printability.

Japanese Utility Model Publication No. 5-41015 WO2008-053757 Japanese Patent Laid-Open No. 11-30854

FIG. 5 is a photograph of a gravure plate having a deep cell depth (60 μm) produced using a general square grid screen so that the shape of the cell and bank can be clearly understood.
When a gravure plate is produced using a general square grid screen, the shape of the cell 3 after corrosion becomes as shown in FIG. 5 as the cell depth becomes deeper, and the bank crossing portion 5 becomes larger. There has been a problem that smooth and uniform coating cannot be performed during printing.

  As a conventional technique for solving such a problem, Patent Document 1 proposes a screen pattern as shown in FIG. That is, a part of the bank (the non-exposed part 2 in FIG. 6) is cut so as to be connected to one of the adjacent cells at each corner of the part (the exposed part 1 in FIG. 6). The lack of a screen pattern has been proposed.

FIG. 7 is a photograph of a gravure plate having a relatively shallow cell depth (30 μm or less) produced using this screen and image-processed so that the shape of the cell and bank can be clearly seen. Further, FIG. 8 is a photograph of a gravure plate having a deep cell depth (60 μm) produced using the same screen so that the shape of the cell and the bank can be clearly understood.
FIG. 7 shows that when the cell depth is relatively shallow, the shapes of the cell 3 and the bank 4 are good and effective.
However, it can be seen from FIG. 8 that when the cell depth is deep, the bank 4 portion becomes thin and short by the development and corrosion processes (6) and (7) of the gravure plate manufacturing method described above. That is, the notched portion where the vertical and horizontal banks 4 intersect becomes deep and large, and when the gravure plate surface is scraped off with a doctor blade, the bank 4 is damaged, and the bank 4 rapidly Worn out to prevent normal printing. In addition, there is a problem that the doctor blade is chipped and the ink at that portion cannot be scraped off.

  The present invention has been made to solve the above-described problems, and can uniformly and smoothly apply ink on the surface of a printing object, and even when a deep cell is formed, the bank portion of the prior art Since the notched portion does not become too large, a gravure plate that is unlikely to cause a problem that the bank portion or the doctor blade is damaged when contacting with the doctor blade can be provided.

As means for solving the above-mentioned problems, the invention according to claim 1 is a gravure screen pattern used for producing a gravure printing plate,
A plurality of square-shaped exposed portions are regularly arranged vertically and horizontally at a predetermined interval,
And each square exposed parts of the, and its one diagonal square exposed parts adjacent in the direction of, and have a linear exposure portion connecting at the apex of the corner opposite to each other ,
According to the thickness of the non-exposed part in the pattern of the gravure screen, the thickness of the linear exposed parts to be connected so that the thickness of the convex part (bank) of the gravure printing plate to be produced is substantially uniform. A gravure screen pattern, characterized by adjusting the .

  The invention described in claim 2 is a gravure screen having the pattern described in claim 1.

The invention according to claim 3 is a gravure plate produced using the gravure screen according to claim 2,
A plurality of concave portions (cells) formed on the surface of the gravure plate are arranged in a square lattice shape, and cells adjacent to one diagonal direction of the square lattice are connected to each other and are in the other direction. It is separated from adjacent cells by a convex part (bank) ,
A gravure plate, wherein the thickness of the convex portion (bank) is formed to be substantially uniform .

  In the gravure printing plate produced using the screen of the present invention, since a part of the bank crossing portion is cut off, the ink can be applied smoothly and uniformly to the printing object. On the other hand, even when the depth is deep, there is no problem that the bank or the doctor blade is damaged at the time of contact with the doctor blade because the cut portion as in the cell of FIG. 8 becomes too large.

The model explanatory drawing of gravure printing. The schematic diagram which shows the relationship between a screen and a pattern. The figure which shows the square lattice type | mold screen of a general gravure. The image processing photograph which shows the gravure cell shape produced with the square lattice type | mold screen. An image processing photograph showing a deep (60 μm) gravure cell shape produced by a general gravure plate square lattice screen. The figure which shows the screen shape of a prior art. The image processing photograph which shows the gravure cell shape produced with the screen shape of a prior art. The image processing photograph which shows the deep (60 micrometer) gravure cell shape produced with the screen shape of the prior art. The figure which shows the screen shape of this invention. The image processing photograph which shows the deep (60 micrometer) gravure cell shape produced with the screen shape of this invention.

FIG. 9 shows a gravure screen pattern according to an embodiment of the present invention.
A plurality of square-shaped exposed portions 6a are regularly arranged vertically and horizontally at a predetermined interval. Each square-shaped exposure portion 6a has a shape that is connected by a square-shaped exposure portion 6a adjacent to one diagonal direction and a linear exposure portion 6b.
In FIG. 9, the linear exposure portion 6b is arranged in a direction connecting the lower left diagonal and the upper right diagonal, but may be arranged in a direction connecting the lower right diagonal and the upper left diagonal.

  The linear exposure portions 6b are arranged so as to connect the opposite vertices of the square exposure portions 6a adjacent in the oblique direction. Further, the thickness of the linear exposure portion 6b needs to be adjusted in consideration of the thickness of the non-exposure portion 7 so as not to be connected to the other exposure portions 6a.

  The screen having the shape shown in FIG. 9 is registered as a laser exposure pattern, and the gravure plate is made according to the above-described method for producing a gravure plate. FIG. 10 shows a photograph in which an example of a gravure plate according to an embodiment of the present invention is subjected to image processing so that the shapes of the cells 3 and the banks 4 can be clearly understood.

  In the gravure plate of FIG. 10, the cells 3 (recesses) are arranged in a square lattice shape and are adjacent to one diagonal direction of the square lattice (the direction connecting the diagonally lower left and the diagonally upper right in FIG. 10). The cells are connected to each other, but are separated from adjacent cells in other directions by banks 4 (convex portions).

  In the gravure plate of FIG. 10, each cell 3 has a depth of 60 μm, but the bank 4 has a substantially uniform thickness including the vicinity of the bank intersection 5 and maintains a good shape. Compared with the conventional photographs (FIGS. 5 and 8), the thickness uniformity of the bank 4 portion of this embodiment is clear.

Printing performed using the gravure plate is not particularly different from the conventional gravure plate.
In the gravure plate of this embodiment, there are locations where the cells 3 are connected to each other, the fluidity of the ink is maintained, and the thickness of the portion of the bank 4 is uniform, so that the surface of the object to be printed is uniform and smooth. Can be applied.
In addition, even when a deep cell is formed, the notched portion like the bank portion of the prior art (the technology of Patent Document 1) does not become too large, so the bank portion and the doctor blade are not in contact with the doctor blade. Are less likely to suffer damage.

In producing a gravure plate having a screen line number of 100 L / inch and a depth of 60 μm, a gravure plate was produced by a gravure plate making system manufactured by Sink Laboratories using the screen shape shown in FIG. The square exposed portion 6a in FIG. 9 is 190 μm in both length and width, and the width of the linear exposed portion 6b is 25 μm.
When a gravure plate was produced using this screen shape, a gravure plate having a portion where cells were connected as shown in the photograph of FIG. 10 and a bank portion having a good shape could be obtained.

  In the gravure printing method, it is particularly effective as a screen when a large amount of ink or the like is applied with a deep plate.

1 ... exposed part (finally corroded to become cell part)
2 ... Non-exposed part (finally becomes bank part)
3 ... Cell 4 ... Bank 5 ... Bank crossing portion 6a, 6b ... Exposure unit 7 on the gravure screen of the present invention ... Non-exposure unit on the gravure screen of the present invention

Claims (3)

A gravure screen pattern used to produce a gravure printing plate,
A plurality of square-shaped exposed portions are regularly arranged vertically and horizontally at a predetermined interval,
And each square exposed parts of the, and its one diagonal square exposed parts adjacent in the direction of, and have a linear exposure portion connecting at the apex of the corner opposite to each other ,
According to the thickness of the non-exposed part in the pattern of the gravure screen, the thickness of the linear exposed parts to be connected so that the thickness of the convex part (bank) of the gravure printing plate to be produced is substantially uniform. Gravure screen pattern, characterized by adjusting .   A gravure screen having the pattern according to claim 1. A gravure plate produced using the gravure screen according to claim 2,
A plurality of concave portions (cells) formed on the surface of the gravure plate are arranged in a square lattice shape, and cells adjacent to one diagonal direction of the square lattice are connected to each other and are in the other direction. It is separated from adjacent cells by a convex part (bank) ,
A gravure plate, wherein the convex portions (banks) are formed to have a substantially uniform thickness .