JPH0347197B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for manufacturing a support for lithographic printing plates, and in particular to an apparatus for roughening the surface of an aluminum plate as a support. be.

[Prior art]

Conventionally, as a lithographic printing plate, there is a so-called PS plate (Presensitized Plate), which is a photosensitive layer formed by coating a photosensitive composition in layers on an aluminum plate, but the surface of the aluminum plate is roughened by various methods. Alternatively, after the surface is roughened, it is etched with an aqueous acid or alkali solution, further subjected to an anodizing treatment, and then, if desired, subjected to a hydrophilic treatment to be used as a support for a lithographic printing plate. A photosensitive layer is provided on this support to form a photosensitive lithographic printing plate, that is, a PS plate,
This is subjected to processes such as exposure, development, correction, and gumming to form a printing plate, which is then attached to a printing machine and printed.

Examples of surface treatment methods for the aluminum plate described above include mechanical roughening methods such as ball graining, wire graining, brush graining, and liquid honing, electrochemical roughening methods called electrolytic graining, and chemical roughening methods. Surface roughening methods, as well as methods that combine these roughening methods, are used. However, each of these conventional methods has the following problems.

In other words, in the case of ball grain, special skills are required to select the type (material) and size of the balls used, adjust the moisture content during polishing, polish time, and evaluate the finished surface, especially for the batch type. However, there was a problem in that it required a lot of work and the productivity was extremely low. In addition, in the case of wire grain, the grain of the resulting aluminum plate surface is uneven, and with brush grain, a roughened surface cannot be obtained with a large degree of roughness, and the polishing brush used is worn out. In addition, the strong friction between the bristles of the brush and the abrasive agent scratches the aluminum surface in complex ways, creating many sharp protrusions that resemble burrs. Even when developing a PS plate, the photosensitive layer that should be removed remains on the plate surface, causing stains on the plate surface, and when handling an aluminum plate, the treated surface (rough surface) is rubbed together, causing scratches on the surface. There were other problems. In electrochemical surface roughening, electrolytic conditions must be precisely controlled in order to maintain a constant grain pattern on the roughened surface, which requires considerable power consumption and requires a large amount of processing time to dispose of electrolyte waste. There were problems such as high costs. In addition, in the case of chemical surface roughening, the treatment time is long, making it unsuitable for mass production, and, like the above-mentioned method, there are problems such as a large amount of expense is required for waste liquid treatment.

On the other hand, in the liquid honing method, an aqueous slurry liquid in which fine abrasive powder is dispersed is sprayed onto the aluminum surface at an accelerated rate using compressed air, so the fine abrasive powder tends to stick to the aluminum surface and form burrs.

As a result of repeated research to solve the problems in each of the above-mentioned methods, the inventors of the present invention have discovered that high-pressure liquid is jetted out from a nozzle at high speed, and this jetted flow is accompanied by fine particles of abrasive material discharged from other discharge holes. We have proposed a method and apparatus for producing an aluminum support for lithographic printing plates, which is characterized in that slurry containing powder is merged and the merged material is made to collide with the surface of an aluminum plate (Japanese Patent Application No. 88082/1989). 58-104150).

[Purpose of the invention]

The present inventors further studied methods for uniformly graining a wide web, and as a result, the present invention was developed.

[Structure of the invention]

That is, in the present invention, a slurry containing fine abrasive powder is supplied to a distribution chamber extending in the width direction of a traveling aluminum web, and the slurry is fitted into the slurry distribution chamber at equal intervals in the width direction of the aluminum web. Discharging the slurry from a plurality of slurry nozzles, merging the discharged slurry with high-pressure liquid jetted from other plurality of nozzles, and colliding the merging with the surface of the aluminum web to perform a cleaning action and graining at the same time. A method and apparatus for producing an aluminum support for a lithographic printing plate, characterized by:

Embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an external view showing an example of the apparatus for manufacturing a lithographic printing plate support of the present invention, FIG. 2 is a cross-sectional view, and FIG.
The figure is an outline drawing of a slurry distribution chamber.
Reference numeral 1 denotes a wide graining manufacturing device, and 2 a plurality of high-pressure water holes for spouting high-pressure water, which are arranged concentrically at equal intervals (Fig. 1). Further, 3 is a slurry hole that spouts slurry water, and is located in the center of the high-pressure water hole 2, and the high-pressure water hole 2 is positioned at an angle α toward the center line of the slurry hole 3. (Figure 2). Further, the above-mentioned items are arranged at equal intervals P. 4 is a slurry distribution chamber, which evenly distributes the slurry liquid to the slurry holes 3;
It has an integrated structure that allows it to be distributed easily and is easy to install (Fig. 3). In FIG. 1, 6 is a slurry tank, 7 is a slurry hose, and 8 is a running aluminum web.

That is, as shown in FIG. 1, in the apparatus of the present invention, one end of a slurry hose 7 is fixed to a tank 6 for storing slurry, and the other end of the slurry hose 7 is connected to a slurry distribution chamber 4. A plurality of slurry nozzles 3 are fitted at equal intervals in the width direction of the aluminum web 8 running in the direction of the arrow, and the tip of the slurry nozzle 3 surrounds the tip of the axis of the slurry nozzle 3. This lithographic printing plate manufacturing apparatus is characterized in that a plurality of nozzle holes 2 are provided which are inclined toward the axial direction of the slurry nozzle 3 and communicate with a high-pressure water pipe 5 on the inlet side.

Further, in FIG. 2, numeral 9 is a high-pressure water distribution chamber, which allows high-pressure water to be delivered uniformly to the high-pressure water nozzle 2, and numeral 10 is a slurry chamber.

Materials for the aluminum plate used in the present invention include pure aluminum and aluminum alloys, and the latter includes aluminum containing trace amounts of silicon, copper, iron, manganese, magnesium, chromium, zinc, lead, bismuth, nickel, etc. There are alloys that have the main component. In any case, it is preferable that the purity of aluminum is 99.0% or more.

Aluminum plates made of such materials are generally rectangular in shape for lithographic printing plates due to printing presses, but in the present invention, they are cut into rectangles, especially for mass production. It is shaped like a band and is handled by winding it up as appropriate. The thickness of the aluminum plate is practically 0.1 to 0.5 mm due to the tensile strength, yield strength, elongation, bending strength, etc. required when the lithographic printing plate made using it is installed in a printing machine. It is selected as appropriate.

On the other hand, the device for bombarding the surface of the aluminum plate with abrasive slurry in order to roughen the surface consists of a nozzle connected to a high-pressure liquid supply section and a spout connected to the abrasive slurry supply section. Both are arranged so that the flow of high-pressure liquid ejected from the nozzle merges with the flow of slurry ejected from the ejection port described later.

The above-mentioned high-pressure liquid supply section is not only a container containing a liquid maintained at a high pressure, but also a system consisting of a container containing a liquid under normal pressure and a pressurized jet pump connected to the container. There are various aspects. In either embodiment, it is necessary that the liquid be ejected from the nozzles connected to each one at a flow rate of 31 to 140 m/sec. The hydraulic pressure that produces this flow rate can be calculated as 5 to 100 kg/cm ² . Also,
An acid or alkali may be added to the liquid as necessary.

On the other hand, the polishing slurry supply section includes a container for storing the slurry, and preferably a stirring mechanism to prevent the solid content of the slurry from settling.

The slurry thus stirred is sent to the nozzle through the connecting pipe by the liquid feed pump, and the slurry is ejected from the nozzle. The jetting speed of the slurry may be approximately 2 to 25 m/sec. The composition of the slurry is water and fine abrasive powder.
The particle size is #20 to #4000, and the concentration of fine powder is 5
-80% (weight ratio), and usually about 30-50% is used. An acid or alkali may be added to the slurry as necessary.

〔Example〕

A graining device with the configuration shown in Figure 1 was manufactured,
The test was carried out using a slurry liquid prepared as described below and high pressure water.

(1) Graining device specifications (a) Slurry jet orifice diameter 10mm (b) High pressure water jet orifice diameter 2mm (c) Number of nozzles 10 (d) Nozzle pitch (P) 25mm (e) Nozzle focal angle (α) 2 degrees ( f) Nozzle focal length 200 mm (2) Slurry preparation Weight ratio abrasive: Alumina particle size 70 μm 40 parts Water 60 parts After mixing both, the mixture was stirred using a stirrer to prevent the abrasive from settling.

(3) Operating conditions (a) Slurry supply amount 40/mm (b) High pressure water pressure 40Kg/cm ^2The graining device is applied to the aluminum surface.
The roughening was performed at an angle of 60°. The surface roughness of the obtained aluminum plate was 0.5μ, and was uniform across the aluminum width.

Next, this aluminum plate was immersed in a 15% (by weight) sulfuric acid aqueous solution (temperature: 25°C), and anodic oxidation treatment was performed for 60 seconds through direct current at a voltage of 22 V at a distance of 150 mm between the electrodes. Further, it was immersed for 30 seconds in a 2% (by weight) aqueous solution (70°C) of JIS No. 3 sodium silicate, then washed with water and dried, and then a 1:1 condensate of p-diazodiphenylamine and formaldehyde was added as a photosensitive component. p-toluenesulfonate was applied to a dry thickness of 1.7 g/m ² and dried.

The lithographic printing plate produced in this way is exposed,
After development, printing was performed using a "KOR-D" printing machine manufactured by Heidelberg AG (West Germany), which showed good scumming prevention performance and produced more than 100,000 prints.

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to uniformly grain a wide aluminum web as described in the examples, and furthermore, since there is a slurry distribution chamber, the slurry liquid can be uniformly distributed to each slurry hole. Can send liquid. In addition, if the slurry hole becomes worn out, the entire distribution chamber can be replaced by replacing it, which can shorten the replacement time. Furthermore, it goes without saying that if the slurry distribution chamber becomes too large to be replaced by a small number of people, one wide graining device may be divided into parts.

[Brief explanation of drawings]

Fig. 1 is an external view of the wide sand graining device, Fig. 2 is a side view of the same, and Fig. 3 is an external view of the distribution chamber. , 4... Slurry distribution chamber, 5... High pressure water piping, 6... Slurry tank, 7... Slurry hose, 8... Aluminum web.

Claims (1)

[Claims] 1. A slurry containing fine abrasive powder is supplied to a distribution chamber extending in the width direction of a traveling aluminum web, and the slurry is fitted into the slurry distribution chamber at equal intervals in the width direction of the aluminum web. The slurry is discharged from a plurality of slurry nozzles, the discharged slurry is combined with high-pressure liquid jetted from a plurality of other nozzles, and the combined liquid is made to collide with the surface of the aluminum web to perform a cleaning action and graining at the same time. A method for producing an aluminum support for a lithographic printing plate, characterized in that: 2. A slurry containing fine abrasive powder is supplied to a distribution chamber extending in the width direction of the running aluminum web, and a slurry containing slurry is supplied to the slurry distribution chamber from a plurality of slurry nozzles fitted at equal intervals in the width direction of the aluminum web. The slurry is discharged, high-pressure liquid jetted from other plurality of nozzles is combined with the discharged slurry, and this combined liquid is collided with the surface of the aluminum web to perform graining, and then anodization treatment is performed. A method for producing an aluminum support for a lithographic printing plate, characterized in that: 3. One end of the slurry hose is fixed to a tank storing slurry, and the other end of the slurry hose is connected to a slurry distribution chamber, and the slurry distribution chamber has a plurality of slurry nozzles arranged at equal intervals in the width direction of the running aluminum web. was fitted to the tip of the slurry nozzle, and surrounded the tip of the axis of the slurry nozzle, and was inclined toward the axis of the slurry nozzle, and the inlet side was connected to the high-pressure water pipe. A manufacturing device for a lithographic printing plate support, characterized in that a plurality of nozzle holes are provided.