JPH07299894A - Manufacture of gravure printing plate - Google Patents

Abstract

PURPOSE:To increase plate wear by forming a resist plate in which projecting line parts and recessing line parts having micron size are continued on the surface in the direction orthogonal to a contact line with a doctor blade face and alternately provided in the direction of the contact line with the doctor blade and irradiating the resist plate with intensive ultraviolet rays after development to sufficiently promote curing. CONSTITUTION:Laser beams are horizontally scanned in a photosensitive resin film 2 in the direction X orthogonal to a contact line with a doctor blade face and also vertically scanned in the direction Y, so that the adjacent lines to be irradiated on a plate face are mutually overlapped and deviated. Flashing irradiation of laser beams is performed in accordance with negative printing information. Successively, development is performed and a resist plate 4 is formed in which projecting line parts 4a and recessing line parts 4b having micron size are continued on the surface in the direction orthogonal to a contact line with the doctor blade face and alternately provided in the direction of the contact line with the doctor blade face. The resist plate 4 is irradiated with intensive ultraviolet rays 5 to promote curing and necessary plate wear is given.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has a very short life such that plate production is quick and ultra-cheap, and plate life is five minutes to decile, but printing demand is small, such as hundreds to thousands. The present invention relates to a method for producing a gravure printing plate made of a resist plate that can be sufficiently put into practical use.

[0002]

2. Description of the Related Art A conventional gravure plate manufacturing method is 100
A photosensitive resin with high sensitivity that can be cured by a weak laser beam such as an argon / neon gas laser beam after the surface of the plate to be plated with ballad copper of about micron is polished by a whetstone or buffed and surface activated. The film is formed by coating so as to have a thickness of 5 to 8 microns, and then the photosensitive resin film is main-scanned with the laser beam in a direction orthogonal to the doctor plate surface contact line, and the adjacent irradiated line on the plate surface of the laser beam. By writing negative print information in the photosensitive resin film by performing sub-scanning so that they overlap and shift each other and performing blinking irradiation of a laser beam according to the print information, development is performed after the negative print information is written in the photosensitive resin film. After the unexposed part of the ink is dissolved, the resist is heated and hardened and then etched to engrave positive printing information on the plate surface in the form of halftone dots. To strike peeling chrome plating in order to give the impression capacity.

[0003]

The above-mentioned conventional gravure printing plate has a printing durability capable of printing 300,000 to 500,000 sheets, but the recent printing demand is focused on the unit of hundreds to thousands of sheets. Since it is shifting, it is not suitable to adopt the above-mentioned conventional gravure plate because not only it takes time to manufacture the plate, but also the plate manufacturing cost is high.

The present invention has been devised in view of the above-mentioned points, and even if the screen wire comes into contact with the doctor for scraping the ink, it can be kept in a good state for about 5 minutes without falling off, and can remain in a good condition for several hundreds. It is an object of the present invention to provide a method for producing a gravure printing plate made of a resist plate, which can provide printing durability capable of printing several to several thousand printed sheets.

[0005]

As a means for solving the above-mentioned problems, the present invention provides a surface of a plate with a photosensitive resin film having a high sensitivity characteristic that can be cured by a weak laser beam such as an argon-neon gas laser. The coating is applied to form a required thick film, and then the photosensitive resin film is main-scanned with the laser beam in a direction orthogonal to the doctor plate surface contact line, and adjacent irradiated lines on the plate surface of the laser beam overlap each other. By sub-scanning so as to shift and blinking irradiation of the laser beam according to the negative print information, and then performing development to form micron-sized convex stripes continuous in the direction orthogonal to the doctor plate contact line. Form a resist plate in which concave cells are alternately arranged in the direction of the doctor plate surface contact line and the cells for storing the ink dropped by the development are positive. And, there is provided a method of manufacturing a gravure printing plate, characterized in that attaching the required printing durability was irradiated with strong ultraviolet light in the resist plate.

[0006]

EXAMPLE An example of the method for producing a gravure printing plate of the present invention will be described with reference to FIG. First, as shown in FIG. 1A, a metal such as copper, nickel, or aluminum,
Alternatively, a photosensitive resin film 2 (for example, an acrylic-based and epoxy-based photosensitive resin agent) having a highly sensitive property that can be cured by a weak laser beam such as an argon-neon gas laser is formed on a plate surface 1 which is a smooth surface or a roll surface of plastic. Is formed by coating so as to form a thick film having a depth necessary for the cell in the most shadow portion, specifically, t = 80 to 100 μm. Then, as shown in FIG. 1B, the photosensitive resin film 2 is main-scanned with the laser beam 3 in the X direction orthogonal to the doctor plate surface contact line, and the adjacent irradiated lines on the plate surface of the laser beam are overlapped. Sub-scanning is performed in the Y direction so as to be overlapped and shifted, and blinking irradiation of a laser beam is performed according to negative print information. Then, Fig. 1
As shown in (c), by performing development, a resist having micron-sized convex stripes 4a and concave stripes 4b, which are continuous in the direction orthogonal to the doctor plate surface contact line, on the surface alternately in the doctor plate surface contact line direction. Form plate 4. Even though the photosensitive resin film 2 is uniformly applied and formed, after development, micron-sized convex stripes 4a and concave stripes 4b are formed on the surface (the sample cross section can be confirmed with a microscope). This is because the beam cross-sectional area of the laser beam is strong at the center and weak at the periphery, so that the degree of curing of the photosensitive film 2 becomes uneven. Subsequently, as shown in FIG. 1 (d), the resist plate 4 is irradiated with strong ultraviolet light 5 to accelerate the curing and impart a required printing durability. The step between the ridge portion 4a and the ridge portion 4b is 2 to 3 microns, and as shown in FIG. 1 (e), the ink staying in the ridge portion 4b is the doctor tip surface 6 and the surface of the resist plate 4. By intervening between and to exhibit lubricity, the doctor tip surface 6 is prevented from being caught such that the screen line in the doctor plate surface contact line direction is peeled off, and slips to enhance lubricity and improve printability. And the concave line portion 4b
The ink that stays in an extremely small amount has a convex flat portion 4a that is strongly flattened only when the doctor's plate surface comes into contact, and as a result, it is present between the doctor tip surface 6 and the surface of the resist plate 4 to exert lubricity. Since a very small amount stays in a thin film form in the concave streak portion 4b and the binding force to the concave streak portion 4b is large, the flatness of the convex streak portion 4a when the plate surface comes into contact with the printing object is smaller than when the doctor makes contact with the plate surface. In addition to this, there is no metastasis and no influence occurs in the highlight part.

[0007]

As described above, the method for producing a gravure printing plate of the present invention has the following effects. Micron-sized ridges and dents that are continuous in the direction perpendicular to the doctor plate surface contact line are alternately arranged in the doctor plate surface contact line direction on the surface, and strong ultraviolet light is irradiated after development to accelerate curing sufficiently. Since it forms a resist plate, a very small amount of ink that stays in the concave streak maintains the lubricity between the doctor tip surface and the plate surface, and the doctor tip surface protects the screen line in the doctor plate surface contact line direction. As a result of avoiding catching such as peeling and slipping, even if the screen wire comes into contact with the doctor for scraping the ink, it can maintain a good condition for about 5 minutes without falling off and print several hundred to several thousand. A resist plate having a sufficient printing durability capable of printing a number of sheets was obtained. Unlike the plating method, the halftone dots (cells) in the highlight part can be opened clearly and deeply, so that an unexpected effect that the transferability of the ink is greatly improved and the gradation level is improved. Since it is a method of producing a resist plate having printing durability capable of printing hundreds or thousands of printed sheets,
Only the photosensitive material is required, ballad copper plating, polishing to smooth the surface of the ballad copper plating, etching, chrome plating, etc. are not required, and the plate production is simple and short as compared to the conventional method, The production cost becomes very low.

[Brief description of drawings]

1A to 1D are manufacturing process diagrams of a method for manufacturing a gravure printing plate according to the present invention, and FIG. 1E is a cross-sectional view for explaining an action on a doctor tip surface of the gravure printing plate according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Plate surface, 2 ... Photosensitive resin film, 3 ... Laser beam, 4 ... Resist plate, 4a ... Ultraviolet light,

Claims (1)

[Claims] 1. A photosensitive resin film having high-sensitivity characteristics that can be cured by a weak laser beam such as an argon-neon gas laser is applied and formed on a plate surface to a required thickness.
Next, the laser beam is mainly scanned on the photosensitive resin film in a direction orthogonal to the doctor plate surface contact line, and sub-scanning is performed so that adjacent irradiated lines on the plate surface of the laser beam are overlapped and deviated from each other. By developing the flashing laser beam according to the information and then developing, micron-sized ridges and recesses that are continuous in the direction perpendicular to the doctor plate surface contact line are alternated in the doctor plate surface contact line direction. A gravure printing characterized by forming a resist plate in which the cells for storing the ink dropped off by the development are positive, and irradiating the resist plate with strong ultraviolet light to impart a required printing durability. How to make a plate.