JP3506265B2 - Method for producing aluminum alloy support for lithographic printing plate - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aluminum alloy support for a lithographic printing plate, and more particularly, to a method suitable for electrochemical surface roughening treatment and photosensitive. The present invention relates to a method for producing an aluminum alloy support for a lithographic printing plate, which is hardly softened when a burning treatment is performed after coating and baking development of a layer. [0002] An aluminum plate (including an aluminum alloy plate) is used as an aluminum support for a printing plate, particularly as a support for an offset printing plate. Generally, the surface of an aluminum alloy support is subjected to a surface treatment such as a surface roughening treatment and an anodic oxidation treatment to obtain a support. As a method for roughening the aluminum alloy support for a printing plate, an AC electrolytic etching method is generally employed, and the current is a special alternating waveform current such as a normal sine wave AC current or a rectangular wave. Is used. The surface of the aluminum alloy support is roughened by alternating current using an appropriate electrode such as graphite as a counter electrode, and is usually performed in a single process. And the printing durability was poor. For this reason, various methods have been proposed so that an aluminum alloy support suitable as a support for a printing plate having a grain having a deep pit having a depth deeper than its diameter is uniformly and densely provided. . Examples of the method include a surface roughening method using a special electrolytic power supply waveform (Japanese Patent Application Laid-Open No. 53-67507), and a ratio of the amount of electricity between an anode and a cathode during electrolytic surface roughening using alternating current ( Japanese Patent Application Laid-Open No. 54-65607, a power supply waveform (Japanese Patent Application Laid-Open No. 55-25381), and a combination of the amount of current per unit area (Japanese Patent Application Laid-Open No. 56-29699) are known. Further, a combination with mechanical roughening (Japanese Patent Laid-Open No. 55-142695) is also known. [0004] The roughened alloy support is subjected to an anodizing treatment and, if necessary, to a hydrophilic treatment, and a photosensitive substance is coated thereon and dried to form a so-called PS plate. The PS plate is subjected to plate making processes such as image printing, development, and gumming. At that time, in order to improve the printing durability of the printing plate, after development, 200
There is a case where a burning treatment for soaking at about 300 ° C. for about 3 to 10 minutes is performed. [0005] The burning treatment has an effect of thermally curing the photosensitive layer resin remaining on the aluminum plate, but at the same time, heat softening of the aluminum plate by heating tends to occur. The heating temperature and heating time of the normal burning process are
200 to 280 ° C., depending on the composition forming the image
Temperature is about 3 to 7 minutes. On the other hand, as a method for manufacturing an aluminum support, a slab (thickness: 400 to 600 mm, width: 1000 to 2000 m) is prepared by melting and holding an aluminum ingot.
m, 2000-6000 mm in length), and after passing through a facing process of cutting the impurity structure portion of the slab surface by a facing machine at a rate of 3 to 10 mm, removing the stress inside the slab and homogenizing the structure, 480-540 ° C in a soaking furnace,
A soaking process is performed for 6 to 12 hours, followed by hot rolling at 480 to 540 ° C. 5 in hot rolling
After rolling to a thickness of 40 mm, cold rolling is performed at room temperature to a predetermined thickness. After that, annealing is performed to homogenize the structure to homogenize the rolled structure and the like, and then cold-rolled to a specified thickness and straightened to obtain a plate having good flatness. The aluminum support thus produced was used as a support for a lithographic printing plate. However, in the case of electrolytic surface roughening treatment, it is particularly susceptible to the target aluminum support.
When manufacturing the aluminum support through the process of melting and holding → casting → facing → heat equalization, heating and cooling are repeated,
Even if there is a step of chamfering the surface layer, variations in metal alloy components and the like occur in the surface layer, causing a reduction in yield as a lithographic printing plate. In addition, when the aluminum support is manufactured through a process of melting and holding → casting → face milling → soaking, particularly in alloy components close to pure Al such as A1050 material, the heat softening property is large, and it can withstand high temperature burning treatment. I couldn't. On the other hand, a method of containing 0.02 to 0.20% of zirconium (see JP-A-61-51395) and a method of defining an intermediate annealing temperature (JP-A-61-272357, JP-A-60-586)
1), a method of defining the electrical conductivity (Japanese Unexamined Patent Publication No.
-67349) and the like. In order to solve the problem that the electrolytic surface roughening property is deteriorated due to the variation of alloy components, the present applicant has first reduced the variation in the material of the aluminum support and reduced the yield of the electrolytic surface roughening treatment. As a method of producing a lithographic printing plate of excellent quality and good yield by improving the quality, casting and hot rolling are continuously performed from molten aluminum to form a hot rolled coil of a thin plate, and then cold rolling is performed. A method for producing a lithographic printing plate support, characterized in that a heat-treated and straightened aluminum support is roughened. (Japanese Unexamined Patent Publication
See Japanese Patent -79798) [0009] The present invention is, however, also the applicant process for manufacturing the previously proposed (JP-3 -79 798 JP), the heat-softenable after burning treatment Was uneven. Further, it is desired that the burning process be performed at a higher temperature and in a shorter time in order to improve the printing durability and shorten the working time. [0010] An object of the present invention is to solve the conventional problems,
It is an object of the present invention to provide a method for producing an aluminum alloy support for a lithographic printing plate, which can improve the yield of electrolytic surface roughening treatment and can stably produce a lithographic printing plate having low thermal softening property after burning treatment. The present inventors have made intensive studies on the relationship between an aluminum support and electrolytic surface roughening treatment, and as a result, have found the present invention which achieves the above object. is there. That is, the object of the present invention is to provide a twin-roll continuous casting pressure directly from a molten aluminum of JIS1050 component into a plate shape.
Extended gastric line, cold rolling to a thickness 2.0~3.0mm in further,
And intermediate annealing, then performing the final cold rolling, straightening, roughening
It allows the tensile strength is not less 15 kg / mm ² or more and a heating temperature 300 ° C., 7 min yield strength when heat-treated at held 10 kg / mm ² or more aluminum alloy supporting
This is achieved by a method for producing an aluminum alloy support for a lithographic printing plate , characterized by producing a support. In the present invention, a method using a cooling roll such as a Hunter method or a 3C method can be used as a method for continuous casting and rolling directly from a molten aluminum into a plate shape. If the Hunter method or 3C method is used, 1
Since a plate of 0 mm or less can be cast, a hot rolling mill is not required. Also, JP-A-60-238001,
Japanese Patent Application Laid-Open No. Sho 60-240360 discloses a method of forming a thin coil. The present invention is to rapidly cool the molten aluminum by a continuous casting method so that the alloy component dissolved in the matrix becomes a solid solution limit or more, and the tensile strength after cold rolling, intermediate annealing, and final rolling is made a certain value or more. Thus, it is possible to provide an aluminum alloy support for a lithographic printing plate that has a proof stress after heating at 300 ° C. for 7 minutes of 10 kg / mm ² or more and is not easily softened even when subjected to a high-temperature burning treatment. An embodiment of the method for producing an aluminum support used in the present invention will be described more specifically with reference to the process conceptual diagram of FIG. Referring to FIG. 1A, reference numeral 1 denotes a melting and holding furnace in which an ingot is melted and held. From here, it is sent to the twin roll type continuous casting machine 2. That is, a thin hot-rolled coil of 4 to 12 mm is formed directly from the molten aluminum and wound by the coiler 3. Coiler wound coil by 3 is cold rolled to 2.0 ～3.0Mm thin plate I by <br/> cold rolling mill 4 shown in FIG. 1 (B). Subsequently, intermediate annealing may be performed by the heat treatment apparatus 5 shown in FIG. Then, it is rolled again to a thickness of 0.1 to 0.5 mm by a cold rolling mill. Next, FIG.
The correction is performed by the correction device 6 shown in FIG. The plate material thus obtained is subjected to a surface roughening treatment. The straightening may be performed simultaneously with the finish rolling. The production conditions will be described in more detail. In the melting and holding furnace 1, it is necessary to maintain the temperature at or above the melting point of aluminum, and the temperature varies depending on the aluminum alloy component. Generally, it is 800 ° C. or higher. In addition, as a measure for suppressing the generation of oxides in the molten aluminum and removing alkali metals that are harmful to quality, an inert gas purge, a flux treatment, and the like are appropriately performed. Subsequently, it is cast by the continuous casting machine 2. There are various casting methods, and currently the industrially operating methods include the twin roll type represented by the Hunter method and the 3C method, and the twin belt type represented by the Hasley method. The casting temperature varies depending on the method and the alloy, but around 700 ° C. is used. When the Hunter method or the 3C method is employed, the molten metal can be solidified and rolling can be performed between twin rolls. By using these continuous castings, rapid cooling of the molten aluminum becomes possible, and the amount of alloy components that form a solid solution in the matrix can be increased. At that time, in order to make the size of the crystal grains uniform, a heat treatment step 5 such as intermediate annealing may be performed, and the cold rolling 4 may be interposed. Next, correction is performed by the correction device 6 to give a predetermined flatness, and an aluminum support is produced and roughened. The straightening may be performed in the last cold rolling. In the present invention, various methods such as mechanical roughening, chemical roughening, electrochemical roughening, and a combination thereof can be used for roughening a lithographic printing plate support. The mechanical graining method, for example, a ball grain, wire <br/> grained, brush grain, and the like liquid honing method. As an electrochemical graining method, an AC electrolytic etching method is generally adopted, and as a current, a normal sine wave AC current or a special alternating current such as a rectangular wave is used. As a pretreatment for the electrochemical graining, etching may be performed using caustic soda or the like. When electrochemical surface roughening is performed, the surface is preferably roughened by an alternating current with an aqueous solution mainly composed of hydrochloric acid or nitric acid. This will be described in detail below. The aluminum support is
First, alkali etching is performed. Preferred alkaline agents are sodium hydroxide, potassium hydroxide, sodium metasilicate, sodium carbonate, sodium aluminate, sodium gluconate and the like. Concentration 0.01-20%, temperature 20-90 ° C, time 5s
It is appropriate to select from the range of ec to 5 min, and the preferable etching amount is 0.1 to 5 g / m ^2.
It is. Particularly in the case of a support having a large amount of impurities, 0.01 to 1
g / m ² is appropriate. (JP-A-1-237197). Subsequently, a substance (smut) insoluble in alkali remains on the surface of the alkali-etched aluminum plate. Therefore, desmutting may be performed as necessary. The pre-processing is as described above.
In the present invention, alternating current electrolytic etching is performed in an electrolytic solution mainly containing hydrochloric acid or nitric acid. The frequency of the alternating current is 0.1 to 100 Hz, preferably 0.1 to 1.
0 or 10 to 60 Hz. The liquid concentration is 3 to 1
50 g / l, more preferably 5 to 50 g / l, and the amount of aluminum dissolved in the bath is suitably 50 g / l or less, more preferably 2 to 20 g / l. Additives may be added as necessary, but in the case of mass production, it becomes difficult to control the liquid concentration. The current density is 5 to 1
00 A / dm ² is suitable, but 10 to 80 A / dm ²
Is more preferred. The power supply waveform is appropriately selected depending on the quality required and the components of the aluminum support used. Japanese Patent Publication Nos. 56-19280 and 55
It is more preferable to use the special alternating waveform described in each of JP-A-19191. Such waveform and liquid conditions are appropriately selected depending on the quality required together with the quantity of electricity, the components of the aluminum support used, and the like. The electrolytically roughened aluminum is then immersed in an alkaline solution to dissolve the smut as part of the smut treatment. As the alkaline agent, there are various kinds such as caustic soda, and the pH is 10 or more, the temperature is 25 to 60 ° C., and the immersion time is 1
It is preferable to carry out in a very short time of 10 to 10 seconds. Next, it is immersed in a liquid mainly composed of sulfuric acid. As for the sulfuric acid solution conditions, the concentration is 50 to 400 g / l, and the temperature is 25 to
65 ° C. is preferred. If the concentration of sulfuric acid is 400 g / l or more, or the temperature is 65 ° C. or more, the corrosion of the treatment tank and the like becomes large, and in the case of aluminum alloy containing manganese of 0.3% or more, the sand which is electrochemically roughened is used. My eyes collapse. The dissolution amount of the aluminum base is 0.2 g / m
^{If two} or more etchings are performed, the printing durability will decrease. Therefore, it is preferable that the etching resistance be 0.2 g / m ² or less. The anodic oxide film has a thickness of 0.1 to 10 g / m ² ,
More preferably, 0.3 to 5 g / m ² is formed on the surface. The anodic oxidation treatment conditions are variously varied depending on the electrolytic solution used, and thus are not unconditionally determined. However, in general, the concentration of the electrolytic solution is 1 to 80% by weight, and the liquid temperature is 5 to 70 ° C.
° C, current density 0.5-60 A / cm ² , voltage 1-100
V, an electrolysis time of 1 second to 5 minutes is appropriate. The grained aluminum plate having an anodized film obtained in this way is stable and excellent in hydrophilicity. Therefore, it is possible to immediately provide a photosensitive coating film thereon. Can further apply a surface treatment.
For example, a silicate layer of the alkali metal silicate described above or an undercoat layer of a hydrophilic polymer compound can be provided. The coating amount of the undercoat layer is 5-150 mg
/ M ² is preferred. Next, a photosensitive coating film is provided on the aluminum support treated in this way, subjected to image exposure, development and plate making, subjected to a burning treatment, and set in a printing machine.
Start printing. (Examples 1, 2 and Comparative Example 1) A continuous casting twin-roll thin plate apparatus as shown in FIG.
000 mm, to form an aluminum plate of thickness 6 mm, its further 3 mm, 2 mm or up to the plate thickness of 0.5 mm,
Rolled respectively cold, to form the cold-rolled plate until further 0.3mm after annealing at 400 ° C. (including orthodontic) cold rolled to the Te <br/> strike material, carried Examples 1 and 2 and Comparative Example 1 were used. (Comparative Examples 2 and 3) Further, as shown in FIG. 2, an ingot 9 is formed from a molten metal supply nozzle 7 through a water-cooled mold 8 by a DC casting apparatus, and is received by an ingot receiving table 10.
Face milling, soaking heat treatment, hot rolling (not shown), thickness 6
mm aluminum plate, cold-rolled to a thickness of 3 mm and 2 mm, and further 0.3% after annealing at 400 ° C.
mm and cold-rolled (including straightening) to Comparative Examples 2-3. Table 1 shows the breakdown of the test materials of Examples-1 and 2 and Comparative Examples 1, 2, and 3. [Table 1] Using these samples, the tensile strength was measured, and the heat treatment was performed in an electric furnace at 300 ° C. for 7 minutes while measuring the sample temperature with a thermocouple, and then the proof stress was measured. [Table 2] All of the comparative examples have a proof stress of 9 kg / mm ² or less. [0027] The same trial as the above-mentioned fee N o. 1 to 5 were used as a lithographic printing plate support, and etched with a 15% aqueous sodium hydroxide solution at a temperature of 50 ° C. so that the amount of etching would be 5 g / m ^2, and after washing with water, 150 g / 1, 50 ° C. in a sulfuric acid solution. 10
It was immersed in sec for desmutting and washed with water. Further, the support was electrochemically roughened in a 16 g / l aqueous nitric acid solution using an alternating waveform current described in JP-B-55-19191. The electrolysis conditions were such that the anode voltage V _A = 14 volts and the cathode voltage V _C = 12 volts, and the quantity of electricity at the anode was 350 coulombs / dm ² . Next, the aluminum plate is subjected to a chemical etching treatment in a 5% aqueous solution of sodium hydroxide so that the dissolution amount of the aluminum plate becomes 0.5 g / m ^2, and then immersed in a sulfuric acid solution of 300 g / l at 60 ° C. for 20 seconds. Then, a desmutting process was performed. further,
Sulfuric acid 150g / l, aluminum ion concentration 2.5g /
1 V aqueous solution at a distance of 150 mm and a voltage of 22 V
Anodizing treatment was performed for 60 seconds by the direct current. On the substrates 1 to 5 prepared as described above, the following compositions were applied so that the coating weight after drying became 2.0 g / m ² , and a photosensitive layer was provided. (Photosensitive solution) N- (4-hydroxyphenyl), methacrylamide / 2-hydroxyethyl methacrylate / acrylonitrile / methyl methacrylate / methacrylic acid (= 15: 10: 30: 38: 7 molar ratio) copolymer (average molecular weight 60000) 5.0 g Hexafluorophosphate of condensate of 4-diazodiphenylamine and formaldehyde 0.5 g Phosphorous acid 0.05 g Dictoria-Puable-BOH (Hodogaya Chemical Co., Ltd.) 0.1 g 2-methoxyethanol. 100.0 g. The photosensitive lithographic printing plate thus prepared was passed through a transparent negative film in a vacuum furnace and from a distance of 1 m with a 3 kw metal halide lamp. After exposure for 2 seconds, the film was developed with a developer having the following composition, and was burned at 300 ° C. for 7 minutes. After performing, and gumming with gum arabic solution, and a lithographic printing plate. (Developer) Sodium sulfite 5.0 g Benzyl alcohol 30.0 g Sodium carbonate 5.0 g Sodium isopropylnaphthalene sulfonate 12.0 g Pure water 1000.0 g Using the lithographic printing plate thus prepared, a printing test was performed according to a normal procedure to evaluate printability. The results are shown in Table 3. [Table 3] As described above, the lithographic printing plate produced by the method for producing a lithographic printing plate support of the present invention has less heat softening particularly to the burning treatment than the conventional lithographic printing plate. It will be excellent. Furthermore, the streamlining of the manufacturing process of the aluminum support greatly reduces the cost of raw materials, and particularly contributes significantly to quality improvement and cost reduction of a lithographic printing plate support.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a continuous casting step (A), a cold rolling step (B), and a heat treatment step (C) of an embodiment of the casting step of the method for producing a lithographic printing plate support of the present invention. ), Conceptual diagrams of the correction process (D). FIG. 2 is a conceptual diagram of an example of a casting process of a conventional method of manufacturing a lithographic printing plate support. [Description of References] 1 Melting and holding furnace 2 Continuous casting machine 3 Coiler 4 Cold rolling mill 5 Heat treatment device 6 Straightening Equipment 7 Molten supply nozzle 8 Water-cooled mold 9 Ingot 10 Ingot cradle

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Masaya Matsuki               4,000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture Fuji               Photo Film Co., Ltd.                (56) References JP-A-5-156414 (JP, A)

Claims (1)

(57) From Claims 1] JIS1050 component molten aluminum, have rows twin roll continuous casting and rolling directly the plate, further a plate
The thickness 2.0~3.0mm cold rolled to intermediate annealing, followed
The final cold rolling, straightening, and roughening are performed so that the tensile strength is 15 kg / mm ² or more and the heating temperature is 3
10kg proof stress when heat treated at 00 ° C for 7 minutes
Manufacturing aluminum alloy supports of at least / mm ²
Of an aluminum alloy support for lithographic printing plates characterized by the following:
Construction method .