JP4329417B2 - Gravure plate manufacturing method - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a method for producing a gravure plate used for gravure printing.
[0002]
[Prior art]
Conventional gravure plate making methods are roughly classified into corrosion methods represented by conventional gravure and mechanical engraving methods. Among the corrosion methods, the conventional gravure method uses a white line screen on carbon tissue and creates a gradation expression by varying the depth of the plate by baking continuous tone positive. Moreover, the net gravure method which improved that the stability of the continuous tone film is low is also used. As the net gravure method, the depth is the same and only the aperture area of the cell is used to change the gray scale expression, or the gravure method that uses a diffusion film to burn the halftone dots and creates a depth difference with the aperture area ( The TH gravure method is also used in the following.) In particular, the TH gravure method can change both the opening area and depth at the same time, so it is rich in gradation expression and used for printed matter with high quality requirements. (For example, refer nonpatent literature 1).
[0003]
The mechanical engraving method, on the other hand, converts the shading of the document into the engraving depth of the diamond needle and engraves it. By using a triangular pyramid needle, the depth and opening size of the engraving cell can be changed simultaneously. .
The difficulty of mechanical engraving is the drawing of linear objects such as characters and ruled lines. Since the principle is to arrange the dots mechanically, the straight line may appear to be a collection of rough dots, and magazines that require character quality are inferior in appearance. In order to increase the resolving power by mechanical engraving, the engraving dots can be made finer. However, if each cell is made smaller, the engraving depth becomes smaller as the opening area is reduced, so that the concentration is as a whole. It was also a problem that the printing was lowered.
[0004]
On the other hand, straight lines and character data can be sufficiently reproduced by the corrosion method, and it is possible to form a plate with a depth that cannot be obtained by the mechanical engraving method. It is also possible to do. However, in the corrosion method, it is necessary to first output a positive film and then expose it to a photoresist such as carbon tissue, which causes problems such as burning dust during exposure and misregistration due to misalignment of positive. there were.
[0005]
In recent years, a method of forming cells by development and corrosion has appeared and has become widespread, in which the exposure process of the corrosion method is a process of directly exposing the digitized image data to halftone dots with scanning laser light. (For example, refer to Patent Document 1.)
[0006]
[Non-Patent Document 1]
Published by Gravure Technology Development History Publication Committee, “History of Gravure Technology Development-History and Current Status of 60 Years”, Published by the Gravure Technology Development History Publication Committee (published by the Japan Printing Society Press), April 1, 1979 , P. 133-149
[Patent Document 1]
JP 11-309950 A (conventional technology)
[0007]
As a result, fine lines and characters that cannot be expressed by mechanical engraving can be expressed with the same quality as conventional corrosion methods, and high-quality cylinders that are not affected by burning of dust or expansion and contraction of positive film can be produced. However, in this method, since the cell depth is constant and it is necessary to express the gradation only by the opening area of the cell, it is difficult to express the gradation by the TH gravure method.
[0008]
[Problems to be solved by the invention]
Therefore, the object of the present invention is to express abundant gradations and fine characters and image lines that have not been fully satisfied by the conventional gravure plate making methods, and has high registration accuracy and no defects due to dust, etc. It is to provide a method for producing high quality gravure plates.
[0009]
[Means for Solving the Problems]
The above object is achieved by the present invention described below. That is, in the method for producing a gravure plate according to claim 1 of the present invention, a) a step of performing exposure using a laser beam on a film resist to bake a pattern; and b) uniform exposure on the entire surface of the film resist on which the pattern is baked. And c) a step of transferring the film resist after uniform exposure to a cylinder; and d) a step of developing, drying and corroding the transferred film resist, and scattering light as the film resist. A method for producing a gravure plate, comprising using a pigment component having the property of:
According to the present invention, by using a film resist containing a pigment component having a property of scattering light, performing exposure suitable for it, developing and corroding, it is possible to change both the opening area and the depth of the cell, There is provided a method for producing a high-quality gravure plate that can express abundant gradations and fine characters and image lines of the TH gravure method, and has high registration accuracy and is free from defects due to dust.
[0010]
The gravure plate manufacturing method according to claim 2 of the present invention includes: a) a step of exposing a film resist using a laser beam to bake a pattern; and b) uniform exposure on the entire surface of the film resist on which the pattern is baked. and performing, c) said comprises a step of transferring a film resist after uniform exposure to the cylinder, d) developing the transferred film resist, drying, a step of corrosion to, the more Engineering baking the picture laser light, and the light focused on the film resist surface, a gravure method according to, characterized in that exposing with light is not focused.
According to the present invention, a film resist is used, and exposure is performed using two types of light, that is, light focused on the film resist and optically blurred light that is not focused, and development, corrosion By changing the light quantity balance of the two types of light, the cell opening area and depth can be freely changed, and the rich gradation and fine characters and lines of the TH gravure method can be expressed more. In addition, a method for producing a high-quality gravure plate free from defects due to high registration accuracy and dust is provided.
[0011]
Moreover, the manufacturing method of the gravure plate concerning Claim 3 of this invention is a manufacturing method of the gravure plate whose said film resist is a carbon tissue.
By utilizing the light diffusing effect of the pigment component contained in the carbon tissue, the resist film is thin in the portion where the unexposed area is large, and the resist film is thick in the portion where the unexposed area is small. Therefore, when the cylinder is corroded, the depth changes as the cell area changes, and the gradation expression is enriched.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, a first embodiment of a gravure plate manufacturing method according to the present invention will be described with reference to the flowchart of FIG. Hereinafter, the carbon resist will be described as a representative example of the film resist.
[0013]
First, as step 1, the pattern is exposed to the carbon tissue using a laser plate making apparatus as shown in FIG. 3 (ST1). In FIG. 3, reference numeral 1 denotes a rotating drum, on which the carbon tissue 2 is fixed. Further, a plurality of fixing pins 3 are provided on the rotating drum in order to fix the carbon tissue 2 with high accuracy. Reference numeral 4 denotes a laser head which exposes the light focused on the carbon tissue on the rotating drum. The laser head unit is attached to 5 lateral feed devices and moves at a constant feed pitch every week of the rotating drum. Reference numeral 6 denotes a drive unit in which a motor for rotating the rotating drum at a constant speed is housed, and 7 denotes a control unit for controlling the entire system and outputting image data.
[0014]
Since carbon tissue has a photosensitive region in the ultraviolet to part of visible light, the device is placed under yellow light that blocks the wavelength to be exposed. In addition, since a dark reaction is caused by heat, the carbon tissue to which photosensitivity is added needs to be stored in a cool and dark place.
[0015]
Cut the carbon tissue taken out from a cool and dark place to the required size, make a pin hole, and attach it to the rotating drum. Subsequently, image data is input, and when data necessary for output is input, the image data is converted into a laser beam output to expose the carbon tissue.
[0016]
Next, as Step 2, uniform exposure is performed on the entire surface of the carbon tissue (ST2). In order to make the influence of the dark reaction of the carbon tissue constant, the entire exposure is performed regardless of the pattern. Thereby, a plate having a stable depth can be provided.
[0017]
Next, as a step 3, the exposed carbon tissue is removed from the rotating drum and transferred onto a gravure cylinder according to a normal corrosion method (ST3), developed (ST4), dried (ST5), and corroded (ST6). I do. After the corrosion, the resist is peeled off (ST7), and a gravure plate is manufactured by performing a surface treatment such as plating in order to increase the printing durability if necessary.
[0018]
The exposed carbon tissue is drawn with the halftone dot size changed according to the gradation, and the resist thickness varies depending on the integrated light quantity. FIG. 4a shows the size and thickness of the halftone dot of the carbon tissue after development.
[0019]
Carbon tissue is mainly composed of gelatin, pigment, and hexavalent chromium. Among these, the pigment is used for the purpose of making it easy to see the progress of corrosion of the cylinder during corrosion. In the present invention, the light scattering effect of the pigment component is used. That is, a part of the laser light is scattered, and the periphery of the exposed portion is exposed with weak light, so that a thin resist film is formed even in a region that is not originally cured. Since the thickness of the thin resist film is proportional to the amount of light at the peripheral portion, the resist film is thin when the unexposed area is large, and the resist film is thick when the unexposed area is small.
[0020]
The thin resist film penetrates the corrosive liquid in the corrosive process, and the corrosive liquid reaching the cylinder surface dissolves the cylinder metal to form a plate. The thin resist films have different thicknesses depending on the amount of peripheral light, and the difference in thickness results in the difference in the penetration rate of the corrosive liquid, and thus the difference in the plate depth.
[0021]
Therefore, the halftone dot of the plate after corrosion has a difference in depth as well as its size, and can produce gradations that cannot be expressed by conventional laser plate making. FIG. 4b shows the halftone dot size and depth of the plate after corrosion.
[0022]
Next, a second embodiment of the method for producing a gravure plate of the present invention will be described with reference to the flowchart shown in FIG.
First, as step 1, the pattern is exposed to the carbon tissue using a laser plate making apparatus as shown in FIG. 3 (ST1).
[0023]
Here, the handling of the exposure apparatus and the carbon tissue is omitted because it conforms to the first embodiment.
[0024]
Cut the carbon tissue taken out from a cool and dark place to the required size, open a pin hole, attach it to a rotating drum, input image data, input the necessary data for output, and convert the image data to laser beam output Then, the carbon tissue is exposed.
[0025]
At this time, as shown in FIG. 6, the light output from the laser light source 41 of the laser head is divided into two by a beam splitter 42 on the way, and one of them converges on the carbon tissue through the shutter 46, the reflecting mirror 43, and the concave mirror 44. Light having a radius of 1 μm to 10 μm, and the other is light having a radius of 10 μm to 100 μm that is not focused on the outermost surface of the carbon tissue through the shutter 46 ′ and the concave mirror 44 ′. I try to be the same.
[0026]
Subsequently, as in step 1, the uniform exposure is performed on the entire surface of the carbon tissue (ST2) as in the first embodiment, and in step 3, the exposed carbon tissue is removed from the rotating drum, and in accordance with a normal corrosion method. Then, it is transferred onto a gravure cylinder (ST3), developed (ST4), dried (ST5), and corroded (ST6). After the corrosion, the resist is peeled off (ST7), and a gravure plate is manufactured by performing a surface treatment such as plating in order to increase the printing durability if necessary.
[0027]
The exposed carbon tissue is drawn with the halftone dot size changed according to the gradation. A difference in the thickness of the carbon tissue is caused by unfocused light, that is, optically blurred light. The size and thickness of the carbon-tissue halftone after development is schematically shown in FIG. 5a. Further, the thickness of the carbon tissue can be freely changed by adjusting the ratio of light division during exposure. It is also possible to create data for low resolution beforehand from the original data of the plate, and to burn light with a radius of 10 μm to 100 μm simultaneously with the laser light which is high resolution data based on the data.
[0028]
Accordingly, the halftone dots of the plate after corrosion are given as much difference as necessary in depth as well as the size thereof, and gradations that cannot be expressed by conventional laser plate making can be produced. The halftone dot size and depth after corrosion is shown schematically in FIG. 5b.
[0029]
【The invention's effect】
As described above, according to the method for producing a gravure plate according to claim 1 of the present invention, both the opening area and the depth of the cell are changed by using a film resist, performing appropriate exposure, developing, and corroding. This makes it possible to produce a high-quality gravure plate that can express abundant gradation and fine characters and image lines of the TH gravure method, and has high registration accuracy and is free from defects due to dust.
[0030]
Further, according to the method for producing a gravure plate according to claim 2 of the present invention, a film resist is used, exposure is performed using two kinds of light, light focused on the film resist and light not focused, and development and corrosion are performed. By changing the light intensity balance of the two types of light, the cell opening area and depth can be freely changed, and the rich gradation and fine characters and lines of the TH gravure method can be expressed. In addition, it is possible to manufacture a high-quality gravure plate that has high registration accuracy and is free from defects caused by dust.
[0031]
Further, according to the method for producing a gravure plate according to claim 3 of the present invention, the light diffusion of the pigment component can be utilized by making the film resist a carbon tissue. You can express the stroke.
[Brief description of the drawings]
FIG. 1 is a flowchart illustrating a method for producing a gravure plate of the present invention.
FIG. 2 is a schematic view illustrating a gravure plate according to a conventional manufacturing method.
FIG. 3 is a schematic view showing an example of a laser plate making apparatus used in the method for producing a gravure plate of the present invention.
FIG. 4 is a schematic cross-sectional view after a development and after b corrosion in the method for producing a gravure plate of the present invention.
FIG. 5 is a schematic cross-sectional view after a development and b corrosion in another method for producing a gravure plate of the present invention.
FIG. 6 is a schematic view of a laser exposure unit used in the method for producing a Beppu gravure plate of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Rotary drum 2 ... Carbon tissue 3 ... Fixed pin 4 ... Laser head 5 ... Horizontal feed device 6 ... Drive part 7 ... Control part 41 ... Laser light source 42 ... Beam splitter 43 ... Reflecting mirrors 44, 44 '... Concave mirror 45 ... Projection surfaces 46, 46' ... Shutter

Claims (3)

A method for producing a plate for use in gravure printing, comprising: a) performing exposure using a laser beam on a film resist to bake a pattern; and b) performing uniform exposure on the entire surface of the film resist onto which the pattern has been baked. C) a step of transferring the film resist after the uniform exposure to a cylinder; and d) a step of developing, drying and corroding the transferred film resist, and having the property of scattering light as the film resist. A method for producing a gravure plate, comprising using a pigment component . A method for producing a plate for use in gravure printing, comprising: a) performing exposure using a laser beam on a film resist to bake a pattern; and b) performing uniform exposure on the entire surface of the film resist onto which the pattern has been baked. and transferring the film resist after c) the uniform exposure to the cylinder, d) developing the transferred film resist, drying, and a step of corrosion, laser light of about Engineering baking the pattern is, A method for producing a gravure plate, wherein exposure is carried out using light focused on a film resist surface and light not focused. The method for producing a gravure plate according to claim 1, wherein the film resist is carbon tissue.

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