JPH03175090A - Key plate for multicolor printing device - Google Patents

Abstract

PURPOSE:To make it easy to perform simultaneous printing processes when a variety of color inks are used in addition to the simultaneous printing of pages by providing key plate which has no photosensitive layer applied on the base but has a protecting film for preventing ink attachment on the base. CONSTITUTION:A key plate has no photosensitive layer applied on the base but has a protecting layer for preventing ink attachment provided on the base. The base of the key plate has a surface roughed by either one of methods such as mechanical, chemical and electrochemical. For example, aluminum material or aluminum material added with other various alloy components is employed for the key plate. An aluminum plate material has a protecting film for preventing ink attachment. The protecting film is formed by applying, for example, a water-soluble resin solution such as arabian rubber, gelatin or polyvinylalcohol and drying it. The preparatory printing plate thus obtained is mounted on plate cylinders 1,2,3,4 of a printing device and multicolor printing is performed in line A, while monoprinting is performed in lines B,C,D.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a waste plate that is fed into a multicolor printing device. [Background of the invention]

For example, newspapers and the like are beginning to be printed in color (multicolor) to give an impact to readers. Incidentally, although such color printing and normal monochrome printing are performed on separate printing lines, it is being considered to perform them on a printing device in which these printing lines are integrated. That is, in the color printing apparatus shown in FIG. 1, the plate cylinder 1 has red ink printing plates (PS plates) 5a, 5b, 5c, and 5d, and the plate cylinder 2 has blue ink printing plates (PS plates) 6a. ,6b,6
e, 6d is the printing plate (PS plate) 7a for black ink on the plate cylinder 3.
, 7b, 7c, and 7cl are yellow ink printing plates (
PS version) 8a, 8b, 8c, 8d are installed respectively,
Ink is supplied from each ink supply line, and multiple pages (in the example in Figure 1, there are 4 print lines, so 4 pages) of 4 colors are printed at a time. If the device prints one page of line A in four colors and prints the remaining three pages of lines B, C, and D in single color, printing plates 5b, 5c, and 5d are used. ,
6b. It is conceivable to avoid supplying ink to the parts 6c, 6+(, 8b, 8c, and 8d. However, this makes the device extremely complicated and the operation is troublesome. Printing plates 5b, 5c for parts B, C, and D,
5d. It has been found that even if each ink is supplied to the portions 6b, 6c, 6d, 8b, 8c, and 8d, it is sufficient to prevent the ink from getting onto the printing plate. For this reason, the 13th plate was exposed and developed, and the plate (waste board) from which the photosensitive layer provided on the 13th plate was completely removed was used as the printing plate 5.
b, 5c, 5d, 6b, 6c, 6cl, 8b, 8c, 8
It has come to be proposed that line A should be installed in place of line A, and line A should be printed in color, and the remaining lines B, C, and D should be printed in single color at the same time. However, when examining the printing characteristics of printed matter printed using such a printing system, it was found that although there were no problems with color printed matter, there were problems with monochromatic printed matter. In other words, printing stains caused by color ink were observed on monochrome printed matter.

[Disclosure of the invention]

The inventor of the present invention investigated the problem of the above-mentioned printing stains when using the 13th plate in which the photosensitive layer was completely removed. It was discovered that the printing stains were not completely removed due to this problem. The present invention has been achieved based on this knowledge. That is, the first object of the present invention is to provide a method for easily printing multiple pages at the same time when multiple pages are printed at the same time and the number of inks used for printing differs between these printed materials. The purpose is to A second object of the present invention is to prevent printing stains from occurring on these plurality of printed materials. The object of the present invention is to provide a multi-color printing device for N-colors (N is an integer of 2 or more) in which a plurality of printing lines are provided and a plurality of pages are printed simultaneously. A waste board used in the printing line (integer below), which has no photosensitive layer coated on its base material, and has a base material coated with a material to prevent ink adhesion. This is achieved by a waste board used in a multicolor printing device, which is characterized by being provided with a protective film. In addition, in this waste board, the base material of the waste board is formed by one or a combination of mechanical methods such as blasting, brush polishing, electrolytic polishing, chemical methods, and electrochemical methods. Surface roughening treatment and subsequent treatments such as anodizing treatment, boehmite treatment, water glass treatment, phosphate treatment,
It is preferable to use one of the hydrophilic treatments such as organic sulfonate treatment alone or in combination. The base material for the waste board is, for example, JIS A1050.
, A1100, A3003, etc., and aluminum materials to which various other alloy components are added are used, but in particular, JP-A-58-42745, JP-A-59-133355, JP-A-60- 63346
No. 1, JP-A-60-220395, JP-A-61
An aluminum-magnesium alloy based aluminum material such as that proposed in Japanese Patent No. 26746 is preferred because of its excellent mechanical properties. In particular, Mg is 1.01lt% to 3. Owt% aluminum material is preferable, that is, Mg is an element added for the purpose of improving strength and fatigue resistance, and most of it is dissolved in solid solution in the aluminum material, and only a small part is ^1-Mg-based intermetallic material. Basically, it exists as a compound at grain boundaries or within grains. When the MH content is less than 1.0 wt%, the yield strength after temper annealing is difficult to increase in order to ensure isotropy of fatigue strength in the rolling direction of aluminum and in the direction perpendicular to the rolling stitches. Moreover, conversely, the content of M is 3.
If it exceeds 0 wt%, the former -M-based intermetallic compounds coarsely precipitated at the grain boundaries or inside the grains due to temper annealing are unevenly etched deeply by electrolytic etching, which tends to cause defects such as stains. be. Such aluminum material ingots are made into plates with a thickness of about 0.1 to 0.5 mm through predetermined processes such as homogenization, hot rolling, cold rolling, intermediate annealing, cold rolling, and final annealing. . Next, the aluminum plate obtained in this way is subjected to, for example, electrolytic etching, but since the surface of the plate is contaminated with oil and other deposits, the aluminum alloy is etched before electrolytic etching. It is desirable to degrease and wash the board according to a conventional method, for example: ■ Solvent degreasing with Trichlorene or Freon, ■ Degreasing with a weak alkaline detergent aqueous solution, ■ H, S04 with a concentration of 1 to 10%.
It is desirable to degrease by degreasing with an aqueous solution or the like. After this, in order to remove the natural oxide film on the surface, it is usually etched by immersion in a caustic soda aqueous solution with a concentration of 1 to 15% at a temperature of 20 to 80°C for 5 seconds to 3 minutes, and then etched with a concentration of 1 to 15%. 10-5% nitric acid or fliE acid aqueous solution
Neutralization and desmutting after alkaline etching is carried out by immersion at a temperature of 0"C for 5 seconds to 3 minutes. After this treatment, electrolytic etching is performed. When using an aqueous hydrochloric acid solution, the concentration is preferably in the range of 0.3 to 311 t%, preferably 0.5 to 2 t%. Chlorides, nitrates, amines, phosphates, etc. may be added.Since the electrolytic conditions vary depending on the electrolytic solution used and the desired degree of electrolytic etching, they cannot be determined unambiguously, but 1.
Generally, the temperature is about 10-80°C, preferably 20-3
At 0″C, the current density (AC) is approximately 20-200^/dm
”, preferably 50 to 1508/am2, and the time is 2 to
500 seconds, preferably 60 to 120 seconds. When performing electrolytic etching using such an electrolytic solution, the alternating current used has an alternating current waveform such as a rectangular wave or trapezoidal wave, which is obtained by alternating positive and negative polarities. However, normal commercial alternating current, ie, sinusoidal single-phase or three-phase alternating current, is sufficient. Aluminum alloy plates that have been electrolytically etched under the above conditions are then desmutted after being washed with water.
The conditions may be those of a conventional method, such as immersion in an aqueous alkali or acid solution at about 10 to 80° C. for about 5 seconds to 3 minutes, thereby desmutting. The electrolytically etched plate thus obtained is treated with an aqueous solution of sulfuric acid or phosphoric acid having a concentration of 10-50%, or a mixture thereof, at a current density of 1-10^/dm2.
After that, a hydrophilic treatment such as water glass treatment is applied. A protective film for preventing ink adhesion is provided on the aluminum plate material thus obtained. Examples of such a protective film include gum arabic, gelatin, polyvinyl alcohol, dextrin, sterabic, straftane, alginates, polyacrylic acids, polyglycerin ester, hydroxyethylcellulose, polyvinylpyrrolidone, polyacrylamide, methylcellulose, hydroxypropylcellulose, There are water-soluble resins such as hydroxymethyl cellulose and carboxymethyl cellulose, and when a solution of these water-soluble resins is applied to the above aluminum plate material and dried, a waste plate used in the multicolor printing device of the present invention is obtained. It will be done.

[Examples 1 to 5] An ingot of the aluminum material shown in Table 1 was subjected to predetermined processes such as homogenization treatment, hot rolling, cold rolling, intermediate annealing, cold rolling, and final annealing to a thickness of 0.30 mm. As a board material,
This aluminum plate material is subjected to electrolytic etching treatment to roughen the surface (center line average roughness Ra is approximately 0.2-2.
0μm. Rmax2 to 20 μn+)L, and then anodization treatment (film thickness of anodized film 0.5 to 3 g/-2) is performed. Thereafter, a water-soluble resin solution of gum arabic was applied and dried to obtain a waste board used in a multicolor printing device provided with a protective film of gum arabic of 0.5 g/m''. The waste board is attached to the plate cylinder of a printing device as shown in Figure 1, and multi-color printing is performed on line A, and multicolor printing is performed on line B.
, C, and D were printed in single color. For comparison, a 23rd plate constructed using the alloy composition used in Example 1 was exposed to light to remove the photosensitive layer, and then a scrap plate coated with the water-soluble resin described above was prepared in the same manner as described above. The same procedure was carried out in place of the waste board in Example 1. Table 2 shows the characteristics of these waste boards and the printing characteristics of the printed matter thus obtained. table table

【effect】

A plurality of waste board ζ printing lines used in the multicolor printing device according to the present invention are provided, and a plurality of pages (N-K
) Color (K is an integer less than or equal to N-1) (This is a waste board used on the line where printing is performed, and this waste board does not have a photosensitive layer coated on its base material, and this Since a protective film for preventing ink adhesion is provided on the base sheet, for example, when single-color and multi-color printing is performed at the same time, it is possible to obtain printed matter 7 with extremely little printing stain, and each time 15 It does not require the troublesome work of completely removing the photosensitive layer of the plate.Moreover, since there is no photosensitive layer to be removed, there is no waste, and there is no wastage of the five sources.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a color printing device. 1.2.3.4... Plate cylinder, 5m, 5b, 5c, 5d, 6a, 6b, 6c, 6d, 7
a, 7b, 7c, 7d, 8a, 8b8c, 8d... printing plate. Procedural amendment January 16, 1990

Claims (2)

[Claims] (1) A multicolor printing device with N colors (N is an integer of 2 or more) that has multiple print lines and prints multiple pages at the same time (N-K) colors (K is an integer of N-1 or less) This is a waste plate used in the line where printing is carried out, and this waste plate does not have a photosensitive layer coated on its base material, and on this base material there is a protective film to prevent ink adhesion. A waste plate used in a multicolor printing device, characterized in that it is provided with a. (2) In the waste plate used in the multicolor printing apparatus according to claim 1, the base material of the waste plate is subjected to surface roughening treatment and hydrophilic treatment.