JP2007055231A - Method of manufacturing support for lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To offer a method of manufacturing a support for a lithographic printing plate which can acquire a lithographic printing original plate excellent in plate wear, smudging resistance, and cleaner resistance. <P>SOLUTION: Disclosed is a method of manufacturing a lithographic printing plate support wherein an aluminum plate 1 is subjected at least to, in order, a mechanical graining treatment in which the aluminum plate 1 is grained to a mean surface roughness R<SB>a</SB>of 0.25 to 0.40 μm using brushes 2, 4 and a slurry liquid 3 containing an abrasive, an electrochemical graining treatment in which the aluminum plate 1 is grained using an alternating current in an aqueous solution containing nitric acid, and an alkali etching treatment in which the aluminum plate 1 is etched in an aqueous alkali solution, thereby acquiring the lithographic printing plate support having a mean surface roughness R<SB>a</SB>after the alkali etching treatment of 0.41 to 0.6 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a lithographic printing plate support. Specifically, the present invention relates to a method for producing a lithographic printing plate support having excellent stain resistance, printing durability, and cleaner resistance.

  The lithographic printing method is a printing method that utilizes the fact that water and oil do not essentially mix, and the printing plate surface of the lithographic printing plate used for this is a region that accepts water and repels oil-based ink ( Hereinafter, this region is referred to as “non-image portion”) and a region that repels water and receives oil-based ink (hereinafter, this region is referred to as “image portion”) is formed.

  A support for a lithographic printing plate used for a lithographic printing plate is formed using an aluminum plate, and this surface is excellent in hydrophilicity and water retention because it is used to carry a non-image part. Various contradictory performances are required, such as excellent adhesion to the image recording layer formed thereon. If the surface of the lithographic printing plate support is too low in hydrophilicity, ink will adhere to the non-image area during printing, and stains on the blanket cylinder, and so-called background stains, will occur. That is, the stain resistance is deteriorated. Also, if the surface water retention is too low, there will be inconveniences such as the occurrence of clogging in the shadow area unless the dampening water is increased during printing. On the other hand, if the adhesiveness with the image recording layer is too low, the image recording layer is easily peeled off, and the durability (printing durability) is deteriorated when the number of printed sheets is large.

Therefore, in order to improve various performances such as stain resistance and printing durability, the surface of the lithographic printing plate support is subjected to various roughening treatments to form irregularities.
As a surface roughening method, for example, a mechanical surface roughening process, an electrochemical surface roughening process, a chemical surface roughening process (chemical etching), or a combination of these is known.

  For example, in Patent Document 1, the aluminum plate according to claim 2 is mechanically polished and then alkali etched, and then hydrochloric acid 25 to 90 g / L, nitric acid 50 to 240 g / L, and aluminum ions 25 to 60 g / L. And electrolytic etching with an electrolytic solution containing 1 to 1.5 parts by weight of hydrochloric acid and 2 to 4 parts by weight of nitric acid with respect to 1 part by weight of aluminum ions, and then anodizing after desmutting A process for producing an aluminum support for a lithographic printing plate characterized in that it is processed is described.

Japanese Patent Laid-Open No. 2001-1663

By the way, in the planographic printing plate, the ink adhering to the non-image area is washed to prevent the printed matter from being stained. Ink adhering to the non-image area is washed by wiping the entire plate surface with a sponge containing an appropriate amount of an acidic or alkaline plate cleaner solution.
However, when the above cleaning is performed, the image recording layer is swollen by the cleaner liquid and the strength of the image recording layer is reduced, or the cleaner liquid permeates between the image recording layer and the support to reduce the adhesion between them. The printing durability tends to decrease.
As a result of examining the lithographic printing plate using the aluminum support described in Patent Document 1, the present inventor has low printing durability (hereinafter also referred to as “cleaner resistance”) after performing the above-described cleaning. I found out.

  Therefore, the first aspect of the present invention is to provide a lithographic printing plate support capable of obtaining a lithographic printing plate precursor having excellent printing durability, stain resistance and cleaner resistance.

In printing using a lithographic printing plate, the operator visually observes the lightness of the non-image area of the printing plate to adjust the balance between the amount of ink and dampening water. Therefore, the ease of observing the brightness, that is, the so-called ease of rising of water is an important characteristic of a lithographic printing plate.
As a result of examining the lithographic printing plate using the aluminum support described in Patent Document 1, the present inventor has not only cleaner resistance but also the ease of shining of the printing plate when set in a printing press, in other words, It was found that the visibility after rising (hereinafter also referred to as “shiny”) was low.

  Accordingly, a second aspect of the present invention aims to provide a lithographic printing plate support capable of obtaining a lithographic printing plate precursor excellent in printing durability, stain resistance, cleaner resistance, and shiny. To do.

The present inventor has further studied the planographic printing plate using an aluminum support which is described in Patent Document 1, the low cleaner resistance is an average surface roughness R _a after the mechanical polishing I found out that it was too big.
In addition, as a result of earnest research to achieve improvements in printing durability, stain resistance, and cleaner resistance, the present inventor has found that an aluminum plate is averaged using at least a brush and a slurry liquid containing an abrasive. a mechanical graining treatment in which the surface roughness R _a is subjected to roughening such that 0.25～0.40Myuemu, electrochemical performing roughening using an alternating current in an aqueous solution containing nitric acid a roughening treatment, an alkali etching treatment of etching in an aqueous alkali solution is subjected in this order, a lithographic printing plate support mean surface roughness R _a after the etching process is 0.41~0.6μm As a result, it was found that the cleaner resistance of the lithographic printing plate precursor was improved, and the first aspect of the present invention was completed.

Further, as a result of earnest research to achieve improvement in printing durability, stain resistance, cleaner resistance, and shiny, the present inventor used at least a brush and a slurry liquid containing an abrasive on an aluminum plate. A mechanical surface roughening treatment for roughening the surface so that the average surface roughness _Ra is 0.25 to 0.42 μm, and using an alternating current in an aqueous solution containing nitric acid and aluminum ions. and electrochemical graining treatment for performing reduction, subjected to an alkali etching treatment of etching in this order in an alkaline aqueous solution, the average surface roughness R _a after the etching process is 0.43~0.6μm When obtaining a support for a lithographic printing plate, the concentration ratio R between the aluminum ion concentration A and the nitric acid concentration N in the electrolytic solution is 0.6 or more, and the aluminum plate in the alternating current is a cathode. When the ratio r between the amount of electricity QR and the amount of electricity QF at the time of anode is 0.8 ≦ r ≦ 1.0, the lithographic printing plate precursor has good printing durability, stain resistance, cleaner resistance, and shiny And the second aspect of the present invention was completed.

That is, the first aspect of the present invention provides the following (1) to (5).
(1) A mechanically roughened surface which is roughened on an aluminum plate using at least a brush and a slurry liquid containing an abrasive so that the average surface roughness _Ra is 0.25 to 0.40 μm. The alkali etching is carried out in this order by a chemical treatment, an electrochemical surface roughening treatment using an alternating current in an aqueous solution containing nitric acid, and an alkali etching treatment etching in an alkaline aqueous solution. the average surface roughness R _a after the treatment to obtain a lithographic printing plate support is 0.41～0.6Myuemu, method of manufacturing a lithographic printing plate support.
(2) Between the mechanical surface roughening treatment and the electrochemical surface roughening treatment, the aluminum plate is subjected to an alkali etching treatment for etching in an alkaline aqueous solution,
After the alkali etching treatment performed after the electrochemical roughening treatment, an electrochemical roughening treatment in which the aluminum plate is roughened using an alternating current in an aqueous solution containing hydrochloric acid, The method for producing a lithographic printing plate support according to (1) above, wherein the anodization treatment is performed in this order to obtain a lithographic printing plate support.
(3) As for the alternating current used in the aqueous solution containing nitric acid, the ratio r of the quantity of electricity QRF when the aluminum plate is cathode and the quantity of electricity QF when anode satisfies 0.4 ≦ r ≦ 0.8 The method for producing a lithographic printing plate support according to (1) or (2) above.
(4) The method for producing a lithographic printing plate support according to any one of (1) to (3) above, wherein the waveform of the alternating current used in the aqueous solution containing nitric acid is a trapezoidal wave.
(5) The method for producing a lithographic printing plate support according to any one of (1) to (4), wherein the concentration of the nitric acid in the aqueous solution containing nitric acid is 15 to 50 g / L.

The second aspect of the present invention provides the following (6) to (8).
(6) Mechanical roughening on the aluminum plate using at least a brush and a slurry liquid containing an abrasive so that the average surface roughness _Ra is 0.25 to 0.42 μm. Treatment, an electrochemical surface roughening treatment using an alternating current in an aqueous solution containing nitric acid and aluminum ions, and an alkali etching treatment performing an etching treatment in an alkaline aqueous solution in this order. the method of manufacturing a alkaline average surface roughness after etching R _a to obtain a lithographic printing plate support is 0.43~0.60μm lithographic printing plate support, the aqueous solution aluminum ion concentration A concentration ratio R between A and nitric acid concentration N is 0.6 or more, and the alternating current has a ratio r between the amount of electricity QR when the aluminum plate is cathode and the amount of electricity QF when anode is 0.8 ≦ r ≦ 1.0, Method of manufacturing the plate printing plate support.
(7) Production of lithographic printing plate support according to (6) above, wherein the aqueous solution containing nitric acid and aluminum ions contains 1 to 15 g / L of nitric acid and 1 to 15 g / L of aluminum ions. Method.
(8) The aluminum plate is subjected to an alkali etching treatment in which etching is performed in an alkaline aqueous solution between the mechanical roughening treatment and the electrochemical roughening treatment, and the aluminum plate is subjected to the electrochemical treatment. After the alkaline etching treatment performed after the general roughening treatment, an electrochemical roughening treatment in which an alternating current is used in an aqueous solution containing hydrochloric acid and an anodizing treatment are performed in this order. The method for producing a lithographic printing plate support according to (6) or (7) above, wherein a lithographic printing plate support is obtained.

  As will be described below, according to the first aspect of the present invention, when used as a lithographic printing plate, it is used for a lithographic printing plate precursor that is excellent in all of stain resistance, printing durability, and cleaner resistance. A support for a lithographic printing plate can be obtained.

  Further, as will be described below, according to the second aspect of the present invention, when a lithographic printing plate is used, the lithographic printing plate is excellent in all of stain resistance, printing durability, cleaner resistance, and shiny. A support for a lithographic printing plate used for an original plate can be obtained.

Hereinafter, the first aspect and the second aspect of the present invention (hereinafter, both are also simply referred to as “the present invention”) will be described in detail.
[Method for producing support for lithographic printing plate]
<Aluminum plate (rolled aluminum)>
The aluminum plate used in the present invention is a metal whose main component is dimensionally stable aluminum, and is made of aluminum or an aluminum alloy. In addition to a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements can also be used.

  In the present specification, various substrates made of the above-described aluminum or aluminum alloy are generically used as an aluminum plate. Examples of foreign elements that may be contained in the aluminum alloy include silicon, iron, manganese, magnesium, chromium, zinc, bismuth, nickel, and titanium, and the content of foreign elements in the alloy is 10% by mass or less. .

As described above, the composition of the aluminum plate used in the present invention is not specified. For example, a conventionally known material described in the fourth edition of the Aluminum Handbook (1990, published by Light Metal Association), for example, JIS Al-Mn aluminum plates such as A1050, JIS A1052, JIS A1100, JIS A1070, JIS A3004 containing Mn, and internationally registered alloy 3103A can be used as appropriate. Further, for the purpose of increasing the tensile strength, an Al-Mg-based alloy or an Al-Mn-Mg-based alloy (JIS A3005) in which 0.1 mass% or more of magnesium is added to these aluminum alloys can also be used. Furthermore, an Al—Zr alloy or an Al—Si alloy containing Zr or Si can also be used. Furthermore, an Al—Mg—Si based alloy can also be used.
Moreover, the aluminum plate obtained by rolling the UBC (Used Beverage Can) ingot which melt | dissolved the used aluminum beverage can can also be used.

The aluminum plate used in the method for producing a lithographic printing plate support of the present invention preferably contains 0.0 to 0.25% by mass of Cu. When the Cu content of the aluminum plate is within this range, a relatively large and more uniform recess is formed in the first electrochemical surface roughening treatment described later. As a result, the lithographic printing plate using the obtained lithographic printing plate support is more excellent in printing durability.
The Cu content is more preferably 0.15% by mass or less, more preferably 0.12% by mass in terms of forming a uniform recess (honeycomb pit) in the first electrochemical surface roughening treatment described later. More preferably, it is more preferably 0.10% by mass or less.
Preference is given to Si: 0.07 to 0.09 mass%, Fe: 0.20 to 0.29 mass%, Mn: 0.01 mass% or less, Mg: 0.01 mass% or less, Cr: 0.0. It is an aluminum plate having a content of 01% by mass or less, Zn: 0.01% by mass or less, Ti: 0.02% by mass or less, and Al: 99.4% by mass or more.

  Regarding the JIS 1050 material, the techniques proposed by the applicant of the present application are disclosed in Japanese Patent Application Laid-Open Nos. 59-153861, 61-51395, 62-146694, 60-215725, and 60-215725. JP 60-215726, JP 60-215727, JP 60-216728, JP 61-272367, JP 58-11759, JP 58-42493, JP 58- 221254, JP-A-62-148295, JP-A-4-254545, JP-A-4-165541, JP-B-3-68939, JP-A-3-234594, JP-B-1-47545, and JP-A-62. It is described in each publication of -140894. In addition, techniques described in Japanese Patent Publication No. 1-35910 and Japanese Patent Publication No. 55-28874 are also known.

  Regarding the JIS1070 material, the techniques proposed by the applicant of the present application are disclosed in JP-A-7-81264, JP-A-7-305133, JP-A-8-49034, JP-A-8-73974, JP-A-8-108659 and It is described in JP-A-8-92679.

  Regarding Al-Mg alloys, the techniques proposed by the applicant of the present application are disclosed in Japanese Patent Publication Nos. Sho 62-5080, Sho 63-60823, Shoko 3-61753, JP Sho 60-20396, JP-A-60-203497, JP-B-3-11635, JP-A-61-274993, JP-A-62-23794, JP-A-63-47347, JP-A-63-47348, JP-A-63-47349. JP-A 64-1293, JP-A 63-135294, JP-A 63-87288, JP-B 4-73392, JP-B 7-100844, JP-A 62-149856, JP-B JP-A-4-73394, JP-A-62-181191, JP-B-5-76530, JP-A-63-30294, and JP-B-6-37116. Also described in JP-A-2-215599, JP-A-61-201747, and the like.

  With regard to Al—Mn alloys, techniques proposed by the applicant of the present application are described in Japanese Patent Application Laid-Open Nos. 60-230951, 1-306288, and 2-293189. In addition, JP-B-54-42284, JP-B-4-19290, JP-B-4-19291, JP-B-4-19292, JP-A-61-35995, JP-A-64-51992, JP-A-4-19592, No. 226394, US Pat. No. 5,009,722, US Pat. No. 5,028,276 and the like.

  With regard to the Al—Mn—Mg alloy, techniques proposed by the applicant of the present application are described in Japanese Patent Application Laid-Open Nos. 62-86143 and 3-2222796. JP-B 63-60824, JP-A 60-63346, JP-A 60-63347, JP-A-1-293350, European Patent No. 223,737, US Pat. No. 4,818, No. 300, British Patent No. 1,222,777, etc.

  Regarding the Al—Zr alloy, the technique proposed by the applicant of the present application is described in Japanese Patent Publication No. 63-15978 and Japanese Patent Application Laid-Open No. 61-51395. Also described in JP-A-63-143234 and JP-A-63-143235.

  The Al—Mg—Si alloy is described in British Patent 1,421,710.

  In order to use an aluminum alloy as a plate material, for example, the following method can be employed. First, a molten aluminum alloy adjusted to a predetermined alloy component content is subjected to a cleaning process and cast according to a conventional method. In the cleaning process, in order to remove unnecessary gas such as hydrogen in the molten metal, flux treatment, degassing process using argon gas, chlorine gas, etc., so-called rigid media filter such as ceramic tube filter, ceramic foam filter, A filtering process using a filter that uses alumina flakes, alumina balls or the like as a filter medium, a glass cloth filter, or a combination of a degassing process and a filtering process is performed.

  These cleaning treatments are preferably performed in order to prevent defects caused by foreign matters such as non-metallic inclusions and oxides in the molten metal and defects caused by gas dissolved in the molten metal. Regarding filtering of the molten metal, JP-A-6-57432, JP-A-3-162530, JP-A-5-140659, JP-A-4-231425, JP-A-4-276031, JP-A-5-311261, JP-A-5-311261 6-136466 and the like. Further, the degassing of the molten metal is described in JP-A-5-51659, Japanese Utility Model Laid-Open No. 5-49148, and the like. The applicant of the present application has also proposed a technique relating to degassing of molten metal in Japanese Patent Application Laid-Open No. 7-40017.

Next, casting is performed using the molten metal that has been subjected to the cleaning treatment as described above. Regarding the casting method, there are a method using a solid mold typified by a DC casting method and a method using a driving mold typified by a continuous casting method.
In DC casting, solidification occurs at a cooling rate in the range of 0.5 to 30 ° C./second. If it is less than 0.5 ° C./second, a large number of coarse intermetallic compounds may be formed. When DC casting is performed, an ingot having a thickness of 300 to 800 mm can be produced. The ingot is chamfered as necessary according to a conventional method, and usually 1 to 30 mm, preferably 1 to 10 mm, of the surface layer is cut. Before and after that, soaking treatment is performed as necessary. When performing the soaking process, heat treatment is performed at 450 to 620 ° C. for 1 to 48 hours so that the intermetallic compound does not become coarse. If the heat treatment is shorter than 1 hour, the effect of soaking may be insufficient. In addition, when soaking is not performed, there is an advantage that the cost can be reduced.

  Then, hot rolling and cold rolling are performed to obtain a rolled aluminum plate. An appropriate starting temperature for hot rolling is 350 to 500 ° C. An intermediate annealing treatment may be performed before or after hot rolling or in the middle thereof. The conditions for the intermediate annealing treatment are heating at 280 to 600 ° C. for 2 to 20 hours, preferably 350 to 500 ° C. for 2 to 10 hours using a batch annealing furnace, or 400 to 600 ° C. using a continuous annealing furnace. Heating is performed for 6 minutes or less, preferably 450 to 550 ° C. for 2 minutes or less. The crystal structure can be made finer by heating at a heating rate of 10 to 200 ° C./second using a continuous annealing furnace.

  The flatness of the aluminum plate finished to a predetermined thickness, for example, 0.1 to 0.5 mm by the above steps may be further improved by a correction device such as a roller leveler or a tension leveler. The flatness may be improved after the aluminum plate is cut into a sheet shape, but in order to improve productivity, it is preferably performed in a continuous coil state. Further, a slitter line may be used for processing into a predetermined plate width. Moreover, in order to prevent generation | occurrence | production of the damage | wound by friction between aluminum plates, you may provide a thin oil film on the surface of an aluminum plate. As the oil film, a volatile or non-volatile film is appropriately used as necessary.

  On the other hand, as the continuous casting method, a twin roll method (hunter method), a method using a cooling roll typified by the 3C method, a double belt method (Hazley method), a cooling belt or a cooling block typified by Al-Swiss Caster II type The method using is industrially performed. When the continuous casting method is used, it solidifies at a cooling rate of 100 to 1000 ° C./second. Since the continuous casting method generally has a higher cooling rate than the DC casting method, it has a feature that the solid solubility of the alloy component in the aluminum matrix can be increased. Regarding the continuous casting method, the techniques proposed by the applicant of the present application are disclosed in JP-A-3-79798, JP-A-5-201166, JP-A-5-156414, JP-A-6-262203, and JP-A-6-122949. JP-A-6-210406 and JP-A-6-26308.

  When continuous casting is performed, for example, if a method using a cooling roll such as a Hunter method is used, a cast plate having a thickness of 1 to 10 mm can be directly cast continuously, and the hot rolling step is omitted. The advantage of being able to In addition, when a method using a cooling belt such as the Husley method is used, a cast plate having a thickness of 10 to 50 mm can be cast. Generally, a hot rolling roll is arranged immediately after casting and continuously rolled. Thus, a continuous cast and rolled plate having a thickness of 1 to 10 mm is obtained.

  These continuous cast and rolled plates are subjected to processes such as cold rolling, intermediate annealing, improvement of flatness, slits, and the like in the same manner as described for DC casting. Finished to a thickness of 5 mm. Regarding the intermediate annealing condition and the cold rolling condition when using the continuous casting method, the techniques proposed by the applicant of the present application are disclosed in JP-A-6-220593, JP-A-6-210308, JP-A-7-54111, It is described in JP-A-8-92709.

  The aluminum plate used in the present invention is preferably subjected to H18 tempering as defined in JIS.

Various characteristics described below are desired for the aluminum plate thus manufactured.
The strength of the aluminum plate is preferably such that the 0.2% proof stress is 120 MPa or more in order to obtain the stiffness required for a lithographic printing plate support. Further, in order to obtain a certain level of waist strength even when performing a burning treatment, the 0.2% yield strength after heat treatment at 270 ° C. for 3 to 10 minutes is preferably 80 MPa or more, and 100 MPa or more. It is more preferable that In particular, when the waist strength is required for an aluminum plate, an aluminum material added with Mg or Mn can be used, but if the waist is strengthened, the ease of fitting to the plate cylinder of a printing press becomes inferior. Depending on the application, the material and the amount of trace components added are appropriately selected. With regard to these, techniques proposed by the applicant of the present application are described in Japanese Patent Application Laid-Open Nos. 7-126820 and 62-140894.
The aluminum plate preferably has a tensile strength of 160 ± 15 N / mm ² , a 0.2% proof stress of 140 ± 15 MPa, and an elongation specified by JIS Z2241 and Z2201 of 1 to 10%.

  The crystal structure of the aluminum plate may cause poor surface quality when the surface of the aluminum plate is subjected to chemical or electrochemical surface roughening. It is preferably not too coarse. The crystal structure on the surface of the aluminum plate preferably has a width of 200 μm or less, more preferably 100 μm or less, still more preferably 50 μm or less, and the length of the crystal structure is 5000 μm or less. Is preferably 1000 μm or less, and more preferably 500 μm or less. With regard to these, techniques proposed by the applicant of the present application are described in Japanese Patent Laid-Open Nos. 6-218495, 7-39906, and 7-124609.

  The alloy component distribution of the aluminum plate, when chemical surface roughening treatment or electrochemical surface roughening treatment is performed, poor surface quality occurs due to non-uniform distribution of the alloy component on the surface of the aluminum plate. Therefore, it is preferable that the surface is not very uneven. With regard to these, the techniques proposed by the applicant of the present application are described in Japanese Patent Laid-Open Nos. 6-48058, 5-301478, and 7-132689.

  In the intermetallic compound of the aluminum plate, the size and density of the intermetallic compound may affect the chemical roughening treatment or the electrochemical roughening treatment. With regard to these, techniques proposed by the applicant of the present application are described in Japanese Patent Laid-Open Nos. 7-138687 and 4-254545.

<Surface treatment>
In the method for producing a lithographic printing plate support according to the first aspect of the present invention, the average surface roughness _Ra is 0 using at least a brush and a slurry containing an abrasive on the aluminum plate described above. Mechanical roughening treatment for roughening to 25 to 0.40 μm and electrochemical roughening treatment for roughening using an alternating current in an aqueous solution containing nitric acid (hereinafter “ A first electrochemical surface roughening process ”) and an alkali etching process (hereinafter also referred to as“ second etching process ”) in which etching is performed in an alkaline aqueous solution in this order. A lithographic printing plate support having an average surface roughness _Ra of 0.41 to 0.6 μm is obtained.
Further, the above-described aluminum plate is further subjected to an alkali etching process (hereinafter referred to as “first etching process”) in which etching is performed in an alkaline aqueous solution between the mechanical surface roughening process and the first electrochemical surface roughening process. Electrochemical roughening treatment (hereinafter referred to as “second electrochemical roughening treatment”) in which an aqueous solution containing hydrochloric acid is used to roughen the surface using an alternating current after the second etching treatment. And anodic oxidation treatment in this order to obtain a lithographic printing plate support.

In the method for producing a lithographic printing plate support according to the second aspect of the present invention, the average surface roughness _Ra is 0.00 on the aluminum plate described above using at least a brush and a slurry liquid containing an abrasive. It contains mechanical surface roughening for roughening to 25 to 0.42 μm, nitric acid and aluminum ions, and R (where R = aluminum ion concentration A / nitric acid concentration N) is 0.00. Rough surface using an alternating current satisfying 0.8 ≦ r ≦ 1.0 (where r = amount of electricity QR when the aluminum plate is the cathode / amount of electricity QF when the aluminum plate is the anode) in an aqueous solution of 6 or more Electrochemical roughening treatment (hereinafter also referred to as “first electrochemical roughening treatment”) and alkaline etching treatment (hereinafter referred to as “second etching treatment”) in which etching is performed in an alkaline aqueous solution. ) And in this order To an average surface roughness R _a after the etching process to obtain a lithographic printing plate support is 0.43～0.6Myuemu.

Moreover, in the manufacturing method of the support body for lithographic printing plates of this invention, various processes other than the above may be included.
Specifically, for example, an aluminum plate is mechanically roughened, first etched, desmutted in an acidic aqueous solution (hereinafter also referred to as “first desmutted”), first electrochemical. Roughening treatment, second etching treatment, desmutting treatment in an acidic aqueous solution (hereinafter also referred to as “second desmutting treatment”), second electrochemical roughening treatment, etching treatment in an alkaline aqueous solution (hereinafter referred to as “the second desmutting treatment”). Preferred examples include a third etching treatment ”, a desmut treatment in an acidic aqueous solution (hereinafter also referred to as“ third desmut treatment ”), and an anodizing treatment in this order.
Further, after the anodizing treatment, a sealing treatment, a hydrophilization treatment, or a sealing treatment and a subsequent hydrophilization treatment are also preferable.
Hereinafter, each step of the surface treatment will be described in detail.

<Mechanical roughening>
In a first aspect of the present invention, by using the slurry containing the brush and an abrasive, the average surface roughness R _a of the aluminum plate described above 0.25～0.40Myuemu, preferably 0.28～ A mechanical roughening treatment is performed to mechanically roughen to 0.37 μm, more preferably 0.30 to 0.35 μm.
By making the average surface roughness _Ra into the above-described range by mechanical surface roughening treatment, and then performing a first electrochemical surface roughening treatment described later, the cleaner resistance can be made excellent. Further, since formation of deep concave portions that occur locally can be prevented, a lithographic printing plate precursor having excellent sensitivity can be obtained.

In a second aspect of the present invention, by using the slurry containing the brush and abrasives, the average surface roughness R _a of the aluminum plate described above 0.25～0.42Myuemu, preferably 0.30 to Mechanical roughening treatment is performed to mechanically roughen to 0.40 μm, more preferably 0.31 to 0.39 μm.
By setting the average surface roughness _Ra to the above range by the mechanical surface roughening treatment, the average inclination Δa of the aluminum plate surface does not become too large. Therefore, when the dissolution amount of the aluminum plate is set low in the first etching treatment In addition, the stain resistance is not easily lowered. Since the amount of dissolution of the aluminum plate can be set low, the amount of the etching solution can be reduced. Further, since formation of deep concave portions that occur locally can be prevented, a lithographic printing plate precursor having excellent sensitivity can be obtained.
Further, (average surface roughness R _a / average inclination Δa) × 100 is more preferably 3.5 to 6.0.

The mechanical surface roughening treatment is a method (brush grain method) in which one type or two or more types of brushes having different bristle diameters are used to perform brush polishing while supplying a slurry liquid containing an abrasive to the surface of the aluminum plate. Specific examples thereof include a wire brush grain method in which the aluminum surface is scratched with a metal wire, and a brush grain method in which the surface is grained with a nylon brush.
In addition, the brush grain method generally uses synthetic resin hair made of synthetic resin such as nylon (registered trademark), polypropylene, and vinyl chloride resin on the surface of a cylindrical body, and brush hair (animal hair, steel wire, etc.) Roller brushes (brushes) such as those in which a material is planted on a roller-shaped base part with uniform hair length and flocking distribution, small holes are drilled in the base part and brush hair bundles are implanted, and channel roller type Roll), and by rubbing one or both of the surfaces of the aluminum plate described above while spraying a slurry liquid containing an abrasive on a rotating roller brush.

Flexural modulus of the brush bristles is preferably from 10,000~40,000kgf / cm ^2, and more preferably 15,000~35,000kgf / cm ^2. The strength of the bristle of the brush hair is preferably 500 gf or less, and more preferably 400 gf or less.
Nylon is preferable as the material of the bristle sufficiently satisfying such characteristics. Specifically, nylon 6, nylon 6,6, nylon 6,10, and the like can be used. Among them, it is particularly preferable to use nylon 6 · 10 from the viewpoints of tensile strength, abrasion resistance, dimensional stability due to water absorption, bending strength, heat resistance, recoverability, and the like.

Such a nylon brush preferably has a low water absorption rate. Specific examples thereof include nylon bristle 200T (6,10-nylon, softening point: 180 ° C., melting point: 212 to 214 ° C., manufactured by Toray Industries, Inc. Specific gravity: 1.08 to 1.09, moisture content: 1.4 to 1.8 at 20 ° C. and relative humidity 65%, 2.2 to 2.8 at 20 ° C. and relative humidity 100%, dry tensile strength: 4 0.5-6 g / d, dry tensile elongation: 20-35%, boiling water shrinkage: 1-4%, dry tensile resistance: 39-45 g / d, Young's modulus (dry): 380-440 kg / mm ² ) Is preferred.

Moreover, it is preferable that the hair length after the flocking of a brush hair is 10-200 mm. In addition, it is preferable that the flocking density at the time of planting in a roller base part is 30-1000 per cm < ² >, and it is more preferable that it is 50-300.
Moreover, it is preferable that the bristle hair diameter is 0.24 to 0.83 mm. When the bristle diameter is within this range, it becomes easy to ensure _a desired average surface roughness (R _a = 0.25 to 0.40 μm), and the stain resistance on the blanket is also improved.
The cross-sectional shape of the brush hair is preferably circular.

The number of brushes is preferably 1 to 10, and more preferably 1 to 6.
Further, as described in JP-A-6-135175, a brush (for example, a roller brush) may be used in combination of two or more brushes having different bristle diameters. Several different brushes (for example, 2 to 3) can be used. When two or more types of brushes are used, the brush used first in the brush grain is generally called a first brush, and the brush used last is called a second brush.

When a roller brush is used as the brush, the number of rotations of the brush is preferably selected arbitrarily in the range of 100 to 500 rpm.
As shown in FIG. 1, the roller brush is preferably rotated in the forward direction in the aluminum plate conveying direction. However, when there are a large number of roller brushes, some of the roller brushes may be reversed. . The pushing amount of the roller brush is preferably managed by the load of the rotation drive motor of the roller brush. Specifically, the power consumption of the rotation drive motor is preferably 1.0 to 15 kW. In addition, the support roller has a rubber or metal surface and is kept straight.

The polishing slurry liquid is a known abrasive described in JP-A-6-135175 and JP-B-50-40047, specifically pumice stone, quartz sand, aluminum hydroxide, alumina powder, carbonized An abrasive having an average particle diameter of 1 to 50 μm (preferably 20 to 45 μm) such as silicon, silicon nitride, volcanic ash, carborundum, and gold sand is used with a specific gravity of 1.05 to 1.3 (preferably 1.10 to 1.20). What is dispersed in water within such a range is preferable. The average particle diameter refers to the particle diameter at which the cumulative ratio is 50% when taking the cumulative frequency of the ratio of the particles of each diameter to the volume of all abrasives contained in the slurry liquid. If it is the above-mentioned range, the average particle diameter of an abrasive | polishing agent is excellent in roughening efficiency, and can narrow a graining pitch.
As the abrasive, it is more preferable to use pumice stone, silica sand, and aluminum hydroxide, and it is more preferable to use silica sand.

The use of pumice stone is preferable because it is inexpensive and is used as an industrial abrasive, so that the supply is stable.
As the pumice stone, those containing the following components are preferably used.
<Pumice stone ingredients>
Silica (silicic acid content: SiO ₂ ) 70-80% by mass
Alumina (Al ₂ O ₃ ) 10-20% by mass
Iron oxide (Fe ₂ O ₃ ) 3% by mass or less Other remaining

Silica sand is harder and harder to break than other abrasives, so that particles are rarely broken during the metal roughening treatment. Accordingly, the surface of the obtained lithographic printing plate support is uniformly roughened, and it is possible to reduce streaks generated on the surface. Therefore, the appearance of the lithographic printing plate support surface is improved. There is an advantage that it is easy to distinguish the scratches on the surface.
The average particle size of the silica sand is preferably 3 to 40 μm, and more preferably 5 to 30 μm. When silica sand having an average particle diameter is used as an abrasive, the roughening efficiency is improved and the graining pitch can be narrowed, so that the printing durability, stain resistance, cleaner resistance, and shiny are excellent, In particular, a lithographic printing plate excellent in shiny can be obtained. As the silica sand, it is preferable to use one containing the following components.

<Silica sand component>
Silica (silicic acid content: SiO ₂ ) 93% by mass or more Alumina (Al ₂ O ₃ ) 3% by mass or less Iron oxide (Fe ₂ O ₃ ) 2% by mass or less Other remaining

  The polishing slurry liquid may contain a thickener, a dispersant (for example, a surfactant), a preservative, and the like in addition to the abrasive.

  As a method for supplying such a polishing slurry liquid to the surface of the aluminum plate, for example, a method of spraying the slurry liquid can be preferably cited. Moreover, you may use the method described in Unexamined-Japanese-Patent No. 55-74898, 61-162351, and 63-104889. Furthermore, as described in JP-A-9-509108, an aluminum plate in an aqueous slurry comprising a mixture of particles made of alumina and quartz at a mass ratio in the range of 95: 5 to 5:95. A method of brush polishing the surface can also be used. The average particle size of the mixture at this time is preferably in the range of 1 to 40 μm, particularly 1 to 20 μm in the first aspect of the present invention, and 5 to 30 μm in the second aspect of the present invention. .

In the present invention, the number of rotations of the brush, the number of brushes, the direction of rotation of the brush, the diameter of the brush, the length of the brush, the diameter of the brush roller, the type of abrasive, the particle size of the abrasive, the specific gravity of the abrasive, and the polishing flow rate, the force for pressing the brush material (pushing amount), by adjusting the conditions of the moving speed of the aluminum plate as appropriate, the average surface roughness R _a of the aluminum plate after mechanical graining treatment of the present invention the In one aspect, it can be 0.25 to 0.40 μm, and in the second aspect of the present invention, it can be 0.25 to 0.42 μm.

As these conditions, the following ranges are particularly preferable.
<In the case of the first aspect of the present invention>
Brush rotation speed: 150-350 rpm,
Number of brushes: 1-3
Brush rotation direction: Same as the movement direction of the aluminum plate,
Brush hair diameter: 0.24 to 0.3 mm,
Brush hair length: 30-100mm,
Brush roller diameter: 300-600 mm,
Type of abrasive: Aluminum hydroxide or silica sand classified, or pumice crushed and classified,
Abrasive particle size: average particle size 20-40 μm,
Specific gravity of abrasive: 1.05-1.18,
Moving speed of aluminum plate: 30 to 300 m / min

<In the case of the second aspect of the present invention>
Brush rotation speed: 150-350 rpm,
Number of brushes: 1-4,
Brush rotation direction: Same as the movement direction of the aluminum plate,
Brush hair diameter: 0.24 to 0.3 mm,
Brush hair length: 30-100mm,
Brush roller diameter: 300-600 mm,
Type of abrasive: silica sand,
Abrasive grain size: average grain size 5-30 μm,
Specific gravity of abrasive: 1.10 to 1.20,
Moving speed of aluminum plate: 30 to 300 m / min

Examples of the apparatus suitable for the mechanical surface roughening treatment by the brush grain method described above include apparatuses described in JP-A-6-135175 and JP-B-50-40047.
FIG. 1 is a side view showing the concept of the brush graining process in the method for producing a lithographic printing plate support of the present invention.
As shown in FIG. 1, roller-like brushes 2 and 4 and two support rollers 5, 6 and 7, 8 that support the aluminum plate 1 are arranged so as to sandwich the aluminum plate 1, and the two support rollers 5, 6, 7, and 8 are arranged such that the shortest distance of the outer surface is smaller than the outer diameter of the roller brushes 2 and 4. The aluminum plate 1 is pressed by the roller-like brushes 2 and 4 and conveyed between the two support rollers 5, 6, 7, and 8 at a constant speed so that the polishing slurry liquid 3 is supplied. The surface of the aluminum plate 1 is brushed by supplying the aluminum plate and rotating the roller brush.

In the present invention, the measurement method of the average surface roughness R _a of the aluminum plate, stylus roughness meter (e.g., Surfcom575, manufactured by Tokyo Seimitsu Co., Ltd.) subjected to two-dimensional roughness measurement in are specified in ISO4287 the average surface roughness was measured 5 times, and the average value and the average surface roughness R _a. In addition, the average inclination Δa was also measured by a two-dimensional roughness measurement with a stylus type roughness meter and measured by the method prescribed in ISO4287.
The conditions for the two-dimensional roughness measurement are shown below.
<Measurement conditions>
Cut-off value 0.8mm, tilt correction FLAT-ML, measurement length 3mm, vertical magnification 10,000 times, scanning speed 0.3mm / sec, stylus tip diameter 2μm

<First etching process>
A 1st etching process is a process which melt | dissolves a surface layer by making the aluminum plate in which the mechanical surface roughening process mentioned above was made to contact an alkaline solution.

  In the present invention, it is preferable to perform the first etching treatment on the aluminum plate subjected to the mechanical roughening. When the first etching process is performed after the mechanical surface roughening process, abrasives, aluminum scraps, rolling oil, dirt, natural oxide films, etc. generated on the surface of the aluminum plate by the mechanical surface roughening process In order to be removed, uniform unevenness is formed on the surface by the first electrochemical roughening treatment, and the first electrochemical roughening treatment can be effectively achieved.

In the first aspect of the present invention, the etching amount in the first etching treatment is preferably 0.1 g / m ² or more, more preferably 0.5 g / m ² or more, and 1 g / m ^2. More preferably, it is preferably 10 g / m ² or less, more preferably 8 g / m ² or less, still more preferably 5 g / m ² or less, and 3 g / m ² or less. More preferably.
In the 2nd aspect of this invention, it is preferable that the etching amount in a 1st etching process is 0.1-6 g / m < ² >, and it is more preferable that it is 2.0-5.5 g / m < ² >.
If the etching amount is too small, uniform pits cannot be generated in the first electrochemical surface roughening process, and unevenness may occur. On the other hand, when there is too much etching amount, the usage-amount of alkaline aqueous solution will increase and it will become economically disadvantageous.

  Examples of the alkali used in the alkaline solution include caustic alkali and alkali metal salts. Specifically, examples of caustic alkali include caustic soda and caustic potash. Examples of the alkali metal salt include alkali metal silicates such as sodium metasilicate, sodium silicate, potassium metasilicate, and potassium silicate; alkali metal carbonates such as sodium carbonate and potassium carbonate; sodium aluminate and alumina. Alkali metal aluminates such as potassium acid; alkali metal aldones such as sodium gluconate and potassium gluconate; dibasic sodium phosphate, dibasic potassium phosphate, primary sodium phosphate, primary potassium phosphate, etc. An alkali metal hydrogen phosphate is mentioned. Among these, a caustic alkali solution and a solution containing both a caustic alkali and an alkali metal aluminate are preferable from the viewpoint of high etching rate and low cost. In particular, an aqueous solution of caustic soda is preferable.

In the first etching treatment, the concentration of the alkaline solution is preferably 30 g / L or more, more preferably 300 g / L or more, and preferably 500 g / L or less, 450 g / L or less. It is more preferable that
The alkaline solution preferably contains aluminum ions. The aluminum ion concentration is preferably 1 g / L or more, more preferably 50 g / L or more, and preferably 200 g / L or less, more preferably 150 g / L or less. Such an alkaline solution can be prepared using, for example, water, a 48 mass% sodium hydroxide aqueous solution, and sodium aluminate.

  In the first etching treatment, the temperature of the alkaline solution is preferably 30 ° C or higher, more preferably 50 ° C or higher, and preferably 80 ° C or lower, and 75 ° C or lower. More preferred.

  In the first etching treatment, the treatment time is preferably 1 second or longer, more preferably 2 seconds or longer, more preferably 30 seconds or shorter, and more preferably 15 seconds or shorter. .

When the aluminum plate is continuously etched, the aluminum ion concentration in the alkaline solution increases and the etching amount of the aluminum plate varies. Therefore, the composition management of the etching solution is preferably performed as follows.
That is, a matrix of conductivity, specific gravity, and temperature, or a matrix of conductivity, ultrasonic propagation velocity, and temperature corresponding to the matrix of caustic soda concentration and aluminum ion concentration is prepared in advance, and the conductivity and specific gravity are prepared. The liquid composition is measured according to the temperature and temperature, or the electrical conductivity, the ultrasonic wave propagation speed, and the temperature, and caustic soda and water are added so that the control target value of the liquid composition is reached. Then, the amount of the etching solution increased by adding caustic soda and water is overflowed from the circulation tank, thereby keeping the amount of the solution constant. As caustic soda to be added, 40 to 60% by mass for industrial use can be used.
As the conductivity meter and the specific gravity meter, it is preferable to use those that are temperature-compensated. As the specific gravity meter, a differential pressure type is preferably used.

  Examples of the method of bringing the aluminum plate into contact with the alkaline solution include, for example, a method in which the aluminum plate is passed through a tank containing the alkaline solution, a method in which the aluminum plate is immersed in a tank containing the alkaline solution, The method of spraying on the surface of a board is mentioned.

  Among these, a method in which an alkali solution is sprayed on the surface of an aluminum plate is preferable. Specifically, a method of spraying an etching solution in an amount of 10 to 100 L / min per spray tube from a spray tube having φ2 to 5 mm holes at a pitch of 10 to 50 mm is preferable. It is preferable to provide a plurality of spray tubes.

After the alkali etching process is completed, it is preferable to drain the liquid with a nip roller, and further perform the water washing process for 1 to 10 seconds and then drain the liquid with a nip roller.
The water washing treatment is preferably carried out using an apparatus for washing with a free-falling curtain-like liquid film, and further using a spray tube.

FIG. 2 is a schematic cross-sectional view of an apparatus for washing with a free-fall curtain-like liquid film. As shown in FIG. 2, the water washing apparatus 100 using a free-fall curtain-like liquid film includes a water storage tank 104 that stores water 102, a water supply pipe 106 that supplies water to the water storage tank 104, and a water storage tank. And a rectifying unit 108 for supplying a free fall curtain-like liquid film from 104 to the aluminum plate 1.
In the apparatus 100, water 102 is supplied from a water supply pipe 106 to a water supply tank 104, and when the water 102 overflows from the water supply tank 104, the water is rectified by a rectifying unit 108, and a free-falling curtain-like liquid film is applied to the aluminum plate 1. Supplied. When the apparatus 100 is used, the liquid amount is preferably 10 to 100 L / min. Moreover, it is preferable that the distance L in which the water 102 between the apparatus 100 and the aluminum 1 exists as a free fall curtain-like liquid film is 20-50 mm. Moreover, it is preferable that the angle (alpha) of an aluminum plate is 30-80 degrees with respect to a horizontal direction.

If an apparatus for washing with a free fall curtain-like liquid film as shown in FIG. 2 is used, the aluminum plate can be uniformly washed with water, so that the uniformity of the treatment performed before the washing process can be improved. Can be improved.
As a specific apparatus for washing with a free-fall curtain-like liquid film, for example, an apparatus described in Japanese Patent Application Laid-Open No. 2003-96584 is preferably exemplified.

  Moreover, as a spray tube used for the water-washing process, for example, a spray tube having a plurality of spray tips in the width direction of the aluminum plate in which spray water spreads in a fan shape can be used. The distance between spray tips is preferably 20 to 100 mm, and the amount of liquid per spray tip is preferably 0.5 to 20 L / min. It is preferable to use a plurality of spray tubes.

<First desmut treatment>
After the first etching process, it is preferable to perform pickling (first desmut process) in order to remove dirt (smut) remaining on the surface. The desmut treatment is performed by bringing an aluminum plate into contact with an acidic solution.

Examples of the acid used include nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, and borohydrofluoric acid.
In the first desmut process performed after the first etching process, it is preferable to use the overflow waste liquid of the electrolyte solution used in the subsequent first electrochemical surface roughening process.

  In the composition management of the desmut treatment liquid, a method of managing by conductivity and temperature, a method of managing by conductivity, specific gravity and temperature, and a conductivity and superconductivity corresponding to a matrix of acidic solution concentration and aluminum ion concentration. Either of the methods managed by the propagation speed of sound waves and temperature can be selected and used.

  In the first desmutting treatment, it is preferable to use an acidic solution containing 1 to 400 g / L acid and 0.1 to 5 g / L aluminum ions.

  The temperature of the acidic solution is preferably 20 ° C. or more, more preferably 30 ° C. or more, and preferably 70 ° C. or less, more preferably 60 ° C. or less.

  In the first desmutting treatment, the treatment time is preferably 1 second or longer, more preferably 4 seconds or longer, and preferably 60 seconds or shorter, more preferably 40 seconds or shorter. .

Examples of the method of bringing the aluminum plate into contact with the acidic solution include, for example, a method of passing the aluminum plate through a bath containing the acidic solution, a method of immersing the aluminum plate in a bath containing the acidic solution, and an acidic solution containing aluminum. The method of spraying on the surface of a board is mentioned.
Among these, a method in which an acidic solution is sprayed on the surface of an aluminum plate is preferable. Specifically, a method of spraying a desmating solution at a rate of 10 to 100 L / min per spray tube from a spray tube having φ2 to 5 mm holes at a pitch of 10 to 50 mm is preferable. It is preferable to provide a plurality of spray tubes.

After the desmutting process is completed, it is preferable to drain the liquid with a nip roller, and further perform the water washing process for 1 to 10 seconds, and then drain the liquid with a nip roller.
The water washing treatment is the same as the water washing treatment after the alkali etching treatment. However, the amount of liquid per spray tip is preferably 1 to 20 L / min.

  In the first desmut process, when the electrolyte overflow waste liquid used in the subsequent first electrochemical surface roughening process is used as the desmut process liquid, the squeezing and washing process with a nip roller is performed after the desmut process. It is preferable to handle the aluminum plate up to the first electrochemical roughening treatment step while spraying a desmut treatment liquid as necessary so that the surface of the aluminum plate does not dry.

<First electrochemical surface roughening treatment>
The first electrochemical surface roughening treatment in the first aspect of the present invention is an electrochemical surface roughening treatment using an alternating current in an aqueous solution containing nitric acid (hereinafter referred to as “first electrolytic solution”). It is.
The first electrochemical surface roughening treatment in the second aspect of the present invention is in an aqueous solution (hereinafter referred to as “first electrolytic solution”) containing nitric acid and aluminum ions and having R of 0.6 or more. The electrochemical surface roughening treatment using an alternating current satisfying 0.8 ≦ r ≦ 1.0.
By applying the first electrochemical surface roughening treatment after the mechanical surface roughening treatment described above, pits having an average opening diameter of 1 to 6 μm can be formed on the surface of the aluminum plate. Excellent resistance to cleaner and dirt. In addition, the amount of electricity used in the first electrochemical surface roughening process can be reduced. If the aluminum plate contains a relatively large amount of Cu, the first electrochemical surface roughening treatment forms relatively large and uniform recesses (pits) on the surface of the aluminum plate. . As a result, the lithographic printing plate using the obtained lithographic printing plate support has excellent printing durability.

  The first electrochemical surface roughening treatment can be performed according to, for example, the electrochemical grain method (electrolytic grain method) described in Japanese Patent Publication No. 48-28123 and British Patent No. 896,563. This electrolytic grain method uses a sinusoidal alternating current, but it may be performed using a special waveform as described in JP-A-52-58602. Further, the waveform described in JP-A-3-79799 can also be used. JP-A-55-158298, JP-A-56-28898, JP-A-52-58602, JP-A-52-152302, JP-A-54-85802, JP-A-60-190392, JP-A-58-120531, JP-A-63-176187, JP-A-1-5889, JP-A-1-280590, JP-A-1-118489, JP-A-1-148592, and JP-A-1-17896. JP-A-1-188315, JP-A-1-1549797, JP-A-2-235794, JP-A-3-260100, JP-A-3-253600, JP-A-4-72079, JP-A-4-72098, The methods described in JP-A-3-267400 and JP-A-1-141094 can also be applied. In addition to the above, it is also possible to perform electrolysis using an alternating current having a special frequency that has been proposed as a method of manufacturing an electrolytic capacitor. For example, it is described in US Pat. Nos. 4,276,129 and 4,676,879.

Various electrolyzers and power sources have been proposed, including US Pat. No. 4,203,637, JP-A-56-123400, JP-A-57-59770, JP-A-53-12738, JP 53-32821, JP 53-32222, JP 53-32823, JP 55-122896, JP 55-13284, JP 62-127500, JP Those described in JP-A-1-52100, JP-A-1-52098, JP-A-60-67700, JP-A-1-230800, JP-A-3-257199 and the like can be used.
Also, JP-A-52-58602, JP-A-52-152302, JP-A-53-12738, JP-A-53-12739, JP-A-53-32821, JP-A-53-32822, JP 53-32833, JP 53-32824, JP 53-32825, JP 54-85802, JP 55-122896, JP 55-13284, JP 48-28123, JP-B-51-7081, JP-A-52-133638, JP-A-52-133840, JP-A-52-133844, JP-A-52-133845, JP-A-53-149135 And those described in JP-A No. 54-146234 and the like can also be used.

In the first aspect of the present invention, it is one of the preferred embodiments that the nitric acid concentration of the first electrolytic solution is 1 g / L or more and less than 15 g / L (this embodiment is hereinafter referred to as “embodiment A”). That said.) In Embodiment A, it is more preferably 7.5 to 12.5 g / L.
Further, in another preferred embodiment, the nitric acid concentration of the first electrolytic solution is 15 to 50 g / L (this embodiment is hereinafter referred to as “embodiment B”). In Embodiment B, it is more preferably 17.5 to 30 g / L. Doing subsequent second etching nitric acid concentration as 15 to 50 g / L, even when the quantity of electricity is relatively low, the average surface roughness R _a of the aluminum plate after the second etching process, a lithographic printing plate It can be set as a suitable value as a support.
Moreover, in the 1st aspect of this invention, it is preferable that the aluminum ion concentration of a 1st electrolyte solution is 1-15 g / L, and it is more preferable that it is 1.5-10 g / L. The aluminum ion concentration can be adjusted by adding, for example, aluminum nitrate (9 hydrate).
Moreover, in the 1st aspect of this invention, it is preferable that the 1st electrolyte solution contains 10-150 mg / L ammonium ion.

In the 2nd aspect of this invention, it is preferable that the nitric acid concentration of a 1st electrolyte solution is 1-15 g / L, and it is more preferable that it is 3.0-12.5 g / L.
Moreover, in the 2nd aspect of this invention, it is preferable that the aluminum ion concentration of a 1st electrolyte solution is 1-15 g / L, and it is more preferable that it is 3.0-12.5 g / L. The aluminum ion concentration can be adjusted by adding, for example, aluminum nitrate (9 hydrate).
In the second aspect of the present invention, the ratio R between the aluminum ion concentration A and the nitric acid concentration N (that is, R = A / N) is 0.6 or more, and 0.6 to 3 is preferable, and 0.75 to 2.2 is more preferable. By setting R within the above range, it is possible to obtain an aluminum support for a lithographic printing plate having excellent stain resistance, printing durability, and shiny.

  Moreover, in the 2nd aspect of this invention, it is preferable that the 1st electrolyte solution contains 10-200 mg / L ammonium ion.

  In the present invention, the first electrolytic solution may be used by adding at least one of nitrate compounds having nitrate ions such as aluminum nitrate, sodium nitrate and ammonium nitrate in a range from 1 g / L to saturation. it can. Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, and silicon, may melt | dissolve in the 1st electrolyte solution.

When the aluminum plate is continuously subjected to electrolytic surface roughening, the concentration of aluminum ions in the alkaline solution increases, and the unevenness of the aluminum plate formed by the first electrochemical surface roughening treatment varies. To do. Therefore, the composition management of the first electrolytic solution is preferably performed as follows.
That is, a matrix of conductivity, specific gravity, and temperature, or a matrix of conductivity, ultrasonic propagation velocity, and temperature, corresponding to the matrix of nitric acid concentration and aluminum ion concentration, is prepared in advance, and the conductivity and specific gravity are prepared. And the temperature, or the liquid composition is measured according to the electric conductivity, the ultrasonic wave propagation speed, and the temperature, and nitric acid and water are added so that the control target value of the liquid composition is reached. Then, the first electrolytic solution increased by adding nitric acid and water is allowed to overflow from the circulation tank, thereby keeping the amount of the solution constant. As nitric acid to be added, 30 to 70% by mass of industrial grade can be used.
As the conductivity meter and the specific gravity meter, it is preferable to use those that are temperature-compensated. As the specific gravity meter, a differential pressure type is preferably used.
A sample taken from the first electrolyte for use in the measurement of the liquid composition is controlled to a constant temperature (for example, 40 ± 0.5 ° C.) using a heat exchanger different from the first electrolyte, It is preferable to use for measurement because the accuracy of measurement is increased.

  Further, by adding and using a compound capable of forming a complex with Cu, uniform graining is possible even for an aluminum plate containing a large amount of Cu. Examples of the compound capable of forming a complex with Cu include ammonia; hydrogen atom of ammonia such as methylamine, ethylamine, dimethylamine, diethylamine, trimethylamine, cyclohexylamine, triethanolamine, triisopropanolamine, EDTA (ethylenediaminetetraacetic acid). And amines obtained by substituting with a hydrocarbon group (aliphatic, aromatic, etc.); metal carbonates such as sodium carbonate, potassium carbonate, potassium hydrogen carbonate and the like. In addition, ammonium salts such as ammonium nitrate, ammonium chloride, ammonium sulfate, ammonium phosphate, and ammonium carbonate are also included.

  The temperature of the first electrolytic solution is preferably 5 to 55 ° C, and more preferably 20 to 50 ° C.

Of the first aspect of the present invention, in the embodiment A, the first electrochemical surface roughening treatment is performed with respect to the aluminum plate, the amount of electricity QR when the aluminum plate is cathode and the amount of electricity QF when anode is used. The ratio r (that is, r = QR / QF, hereinafter also referred to as “current ratio”) is preferably 0.4 ≦ r ≦ 0.8, and 0.5 ≦ r ≦ More preferably, it is applied so as to satisfy 0.7. When it is within the above range, the surface average roughness _Ra and the surface shape suitable as a lithographic printing plate support using an aluminum plate can be obtained with a smaller amount of electricity.
Among Embodiment 1 of the present invention, in Embodiment B, r is preferably 0.3 to 1.0, and more preferably 0.92 to 0.98.

  In the second aspect of the present invention, the first electrochemical roughening treatment is performed such that the ratio r of the amount of electricity QR when the aluminum plate is a cathode and the amount of electricity QF when the aluminum plate is an anode is 0. It is applied so as to satisfy 8 ≦ r ≦ 1.0. In the case of the above range, a more uniform pit is formed, and when it is an aluminum support for a lithographic printing plate, it is an aluminum support for a lithographic printing plate having very excellent stain resistance and printing durability. It becomes possible.

The waveform of the alternating current used for the first electrochemical surface roughening treatment is not particularly limited, and a sine wave, a rectangular wave, a trapezoidal wave, a triangular wave, or the like is used, but a rectangular wave or a trapezoidal wave is preferable, and a trapezoidal wave is used. More preferred.
A trapezoidal wave means what was shown in FIG. In this trapezoidal wave, the time (TP) until the current reaches a peak from zero is preferably 0.5 to 3 msec. When TP exceeds 3 msec, in particular, when an aqueous solution containing nitric acid is used, it becomes susceptible to the influence of trace components in the first electrolytic solution typified by ammonium ions and the like that increase spontaneously by electrolytic treatment. Graining is less likely to occur. As a result, the stain resistance tends to decrease when a lithographic printing plate is obtained. Further, by using a trapezoidal wave, the maximum current value of the power supply device can be designed to be low even when the average current value is the same, so that the cost of the power supply device can be reduced.

The trapezoidal wave duty that can be used is preferably 0.33 to 0.67. However, as described in Japanese Patent Laid-Open No. 5-195300, an indirect power feeding method in which no conductor roll is used for aluminum. It is more preferable to use a trapezoidal wave with a duty of 0.5. The duty is a value obtained by dividing the time during which the aluminum plate undergoes an anodic reaction in one cycle by the time of one cycle.
Further, the frequency of the trapezoidal wave that can be used is preferably 0.1 to 120 Hz, but it is preferable to use a trapezoidal wave of 50 to 70 Hz in view of the equipment. If it is lower than 50 Hz, the carbon electrode of the main electrode is likely to be dissolved, and if it is higher than 70 Hz, it is likely to be affected by the inductance component on the power supply circuit and the power supply cost is increased.

  One or more AC power supplies can be connected to the electrolytic cell. As shown in FIG. 4, the current ratio between the AC anode and cathode applied to the aluminum plate facing the main electrode is controlled to achieve uniform graining and to dissolve the carbon of the main electrode. In addition, it is preferable to install an auxiliary anode and divert part of the alternating current. In FIG. 4, 11 is an aluminum plate, 12 is a radial drum roller, 13a and 13b are main poles, 14 is an electrolytic treatment solution, 15 is an electrolyte supply port, and 16 is a slit. , 17 is an electrolyte passage, 18 is an auxiliary anode, 19a and 19b are thyristors, 20 is an AC power source, 40 is a main electrolytic cell, and 50 is an auxiliary anode cell. A part of the current is shunted as a direct current to an auxiliary anode provided in a separate tank from the two main electrodes via a rectifying element or switching element, so that an anode reaction that acts on the aluminum plate facing the main electrode It is possible to control the ratio between the current value to be applied and the current value to be applied to the cathode reaction.

  As the electrolytic cell, electrolytic cells used for known surface treatments such as a vertical type, a flat type, and a radial type can be used, but a radial type electrolytic cell as described in JP-A-5-195300 is particularly preferable. . The electrolytic solution passing through the electrolytic cell may be parallel or counter to the traveling direction of the aluminum plate (aluminum web).

By the first electrochemical surface roughening treatment, pits having an average opening diameter of 1 to 6 μm can be formed. However, when the amount of electricity is relatively large, the electrolytic reaction is concentrated, and honeycomb pits exceeding 6 μm are also generated.
To obtain such a grain, the total quantity of electricity when the anode of the aluminum plate up until the electrolysis reaction is completed is preferably from 50~300C / dm ^2, in 100~250C / dm ² More preferably.

After the first electrochemical surface roughening treatment is completed, it is preferable to drain the liquid with a nip roller, and further perform the water washing treatment for 1 to 10 seconds and then drain the liquid with a nip roller.
The washing treatment is preferably carried out using a spray tube. As the spray tube used for the water washing treatment, for example, a spray tube having a plurality of spray tips in the width direction of the aluminum plate in which fan water spreads in a fan shape can be used. The distance between spray tips is preferably 20 to 100 mm, and the amount of liquid per spray tip is preferably 1 to 20 L / min. It is preferable to use a plurality of spray tubes.

The current density in the first electrochemical graining treatment, in the main electrolytic cell is preferably from 10~300A / dm ² at the peak current density during the aluminum plate anode reaction is the 15~200A / dm ² More preferably, it is 20-125 A / dm < ² >. In the case of the above range, the productivity is more excellent, the voltage is not increased, and the power supply capacity is not too large, so that the power supply cost can be reduced.

  Moreover, as a power supply device, what used commercial alternating current, an inverter control power supply, etc. can be used, for example. Among them, an inverter control power source using an IGBT (Insulated Gate Bipolar Transistor) element can generate an arbitrary waveform by PWM (Pulse Width Modulation) control, and the width and thickness of the aluminum plate, and the concentration of each component in the electrolyte When the voltage is changed with respect to the fluctuation or the like and the current value (the current density of the aluminum plate) is controlled to be constant, it is preferable in terms of excellent followability.

<Second etching process>
A second etching process is preferably performed between the first electrochemical surface roughening process and the second electrochemical surface roughening process.
The second etching treatment is to dissolve the smut generated in the first electrochemical surface roughening treatment by bringing the aluminum plate subjected to the first electrochemical surface roughening treatment into contact with an alkaline solution; and This is performed for the purpose of dissolving the edge portion of the pit formed by the first electrochemical surface roughening treatment. Since the second etching process is basically the same as the first etching process, only different points will be described below.

In the second etching treatment, the etching amount is preferably at 0.05 g / m ² or more, more preferably 0.1 g / m ² or more, but preferably not more 4g / m ² or less 3.5 g / m ² or less is more preferable. If the etching amount is too small, the edge portion of the pit generated by the first electrochemical surface roughening process will not be smooth in the non-image area of the lithographic printing plate, and the ink will be easily caught, resulting in poor stain resistance. There is a case. On the other hand, if the etching amount is too large, the unevenness generated by the first electrochemical surface roughening treatment becomes small, so that the printing durability may be deteriorated.

In the second etching treatment, the concentration of the alkaline solution is preferably 30 g / L or more, more preferably 300 g / L or more, and preferably 500 g / L or less, 450 g / L or less. It is more preferable that
The alkaline solution preferably contains aluminum ions. The aluminum ion concentration is preferably 1 g / L or more, more preferably 50 g / L or more, and preferably 200 g / L or less, more preferably 150 g / L or less. Such an alkaline solution can be prepared using, for example, water, a 48 mass% sodium hydroxide aqueous solution, and sodium aluminate.

  In the second etching treatment, the temperature of the alkaline solution is preferably 30 ° C. or higher, more preferably 35 ° C. or higher, preferably 60 ° C. or lower, and 50 ° C. or lower. More preferred.

  In the second etching treatment, the treatment time is preferably 1 second or more, more preferably 2 seconds or more, and preferably 30 seconds or less, more preferably 10 seconds or less. .

The average surface roughness R _a after the second etching treatment is preferably 0.43 to 0.60. When the average surface roughness _Ra is in the above range, a lithographic printing plate support excellent in shiny can be obtained.
Moreover, it is preferable that (average inclination (DELTA) _a / average surface roughness _Ra ) * 100 is 4.0-6.0 on the aluminum plate surface after a 2nd etching process.

<Second desmut treatment>
After the second etching process, it is preferable to perform pickling (second desmut process) in order to remove dirt (smut) remaining on the surface. Since the second desmut process is basically the same as the first desmut process, only the differences will be described below.
In the second desmut treatment, nitric acid or sulfuric acid is preferably used.
In the second desmut treatment, it is preferable to use an acidic solution containing 1 to 400 g / L of acid and 0.5 to 8 g / L of aluminum ions.
In the second desmut treatment, the treatment time is preferably 1 second or more, more preferably 4 seconds or more, and preferably 60 seconds or less, more preferably 20 seconds or less. .

<Second electrochemical roughening treatment>
After the second etching process is performed, it is preferable to perform a second electrochemical roughening process.
The second electrochemical surface roughening treatment is an electrochemical surface roughening treatment using an alternating current in an aqueous solution containing hydrochloric acid (hereinafter referred to as “second electrolytic solution”). By the second electrochemical surface roughening treatment, an uneven structure having pits having an average opening diameter of 0.05 to 0.5 μm can be formed on the surface of the aluminum plate. As a result, cleaner resistance is further improved.

  The second electrochemical surface roughening treatment can be performed in substantially the same manner as the first electrochemical surface roughening treatment described above except that the electrolytic solution is different. Only different points will be described below.

The second electrolyte is added to an aqueous solution of hydrochloric acid having a concentration of 1 to 100 g / L in a range from 1 g / L to saturation of at least one hydrochloric acid compound having hydrochloric acid ions such as aluminum chloride, sodium chloride, and ammonium chloride. Can be used. Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, and silicon, may melt | dissolve in the 2nd electrolyte solution.
Specifically, a solution prepared by dissolving aluminum chloride in an aqueous hydrochloric acid solution having a hydrochloric acid concentration of 2 to 10 g / L to adjust the aluminum ion concentration to 3 to 7 g / L is preferable.

  The temperature of the second electrolytic solution is preferably 25 ° C. or higher, more preferably 30 ° C. or higher, preferably 55 ° C. or lower, and more preferably 40 ° C. or lower.

Since hydrochloric acid itself has a strong ability to dissolve aluminum, it is possible to form fine irregularities on the surface with only slight electrolysis. These fine irregularities have an average opening diameter of 0.01 to 0.2 μm and are uniformly generated on the entire surface of the aluminum plate. In order to obtain such a grain, the total amount of electricity involved in the anode reaction of the aluminum plate at the time when the electrolytic reaction is completed is preferably 10 C / dm ² or more, more preferably 50 C / dm ² or more. Is more preferably 100 C / dm ² or less, and more preferably 80 C / dm ² or less. The current density at this time is preferably ²⁰ to 100 A / dm ² at the peak value of the current.
Further, the current ratio r is preferably 0.9 to 1.0, and more preferably 0.92 to 0.98.
In order electrical quantity is in the above range, the amount of aluminum eluted with second electrochemical graining is small, the average surface roughness R _a of the second electrochemical graining after the aluminum plate surface is This is almost the same as after the second etching process. Further, even if the anodizing treatment to be described later, the average surface roughness R _a of the surface of the aluminum plate is substantially the same as that after the second etching process.

The current density in the second electrochemical graining treatment, in the main electrolytic cell, the peak current density during the aluminum plate anode reaction is preferably from 10~300A / dm ^2, in 15~200A / dm ² more preferably is, even more preferably 20~125A / dm ^2. In the case of the above range, the productivity is more excellent, the voltage is not increased, and the power supply capacity is not too large, so that the power supply cost can be reduced.

  The waveform of the alternating current used for the second electrochemical surface roughening treatment is not particularly limited, and a sine wave, a rectangular wave, a trapezoidal wave, a triangular wave, or the like is used, but a rectangular wave or a trapezoidal wave is preferable, and a trapezoidal shape is used. Waves are more preferred. The trapezoidal wave TP used is preferably 0.5 to 3 msec, more preferably 0.6 to 1.5 msec.

  Moreover, as a power supply device, what used commercial alternating current, an inverter control power supply, etc. can be used, for example. Among them, an inverter control power source using an IGBT (Insulated Gate Bipolar Transistor) element can generate an arbitrary waveform by PWM (Pulse Width Modulation) control, and the width and thickness of the aluminum plate, and the concentration of each component in the electrolyte When the voltage is changed with respect to the fluctuation or the like and the current value (the current density of the aluminum plate) is controlled to be constant, it is preferable in terms of excellent followability.

When the aluminum plate is continuously subjected to electrolytic surface roughening, the concentration of aluminum ions in the alkaline solution increases, and the unevenness of the aluminum plate formed by the second electrochemical surface roughening treatment varies. To do. Therefore, it is preferable to manage the composition of the hydrochloric acid electrolyte as follows.
That is, a matrix of conductivity, specific gravity, and temperature, or a matrix of conductivity, ultrasonic propagation velocity, and temperature, corresponding to the matrix of hydrochloric acid concentration and aluminum ion concentration, is prepared in advance, and the conductivity and specific gravity. Then, the liquid composition is measured according to the temperature and the electric conductivity, the ultrasonic wave propagation speed and the temperature, and hydrochloric acid and water are added so that the control target value of the liquid composition is obtained. Then, the electrolytic solution increased by adding hydrochloric acid and water is allowed to overflow from the circulation tank, thereby keeping the amount of the solution constant. As hydrochloric acid to add, the industrial thing of 10-40 mass% can be used.
As the conductivity meter and the specific gravity meter, it is preferable to use those that are temperature-compensated. As the specific gravity meter, a differential pressure type is preferably used.
Samples taken from the electrolyte for use in measurement of the liquid composition are used for measurement after being controlled at a constant temperature (for example, 35 ± 0.5 ° C.) using a heat exchanger different from the electrolyte. However, it is preferable in that the accuracy of measurement is increased.

<Third etching process>
A third etching process is preferably performed after the second electrochemical roughening process.
The third etching treatment is performed by dissolving the smut generated by the second electrochemical roughening treatment by bringing the aluminum plate subjected to the second electrochemical roughening treatment into contact with an alkaline solution, and This is performed for the purpose of dissolving the edge portion of the pit formed by the second electrochemical roughening treatment. Since the third etching process is basically the same as the first etching process, only different points will be described below.

In the third etching treatment, the etching amount not less 0.01 g / m ² or more preferably, more preferably at 0.05 g / m ² or more, also, 0.3 g / m ² or less of Is preferable, and it is more preferable that it is 0.25 g / m ² or less. If the etching amount is too small, the edge portion of the pit generated by the second electrochemical surface roughening process will not be smooth in the non-image area of the lithographic printing plate, and the ink will be easily caught, resulting in poor stain resistance. There is a case. On the other hand, if the etching amount is too large, the unevenness generated by the first electrochemical surface roughening treatment and the second electrochemical surface roughening treatment becomes small, so that the printing durability may deteriorate.

In the third etching process, the concentration of the alkali solution is preferably 30 g / L or more, and in order not to make the unevenness generated by the second electrochemical roughening process in the previous stage too small, It is preferably 100 g / L or less, and more preferably 70 g / L or less.
The alkaline solution preferably contains aluminum ions. The aluminum ion concentration is preferably 1 g / L or more, more preferably 3 g / L or more, and preferably 50 g / L or less, more preferably 8 g / L or less. Such an alkaline solution can be prepared using, for example, water, a 48 mass% sodium hydroxide aqueous solution, and sodium aluminate.

  In the third etching treatment, the temperature of the alkaline solution is preferably 25 ° C. or higher, more preferably 30 ° C. or higher, preferably 60 ° C. or lower, and 50 ° C. or lower. More preferred.

  In the third etching treatment, the treatment time is preferably 1 second or longer, more preferably 2 seconds or longer, more preferably 30 seconds or shorter, and even more preferably 10 seconds or shorter. .

<Third desmut processing>
After the third etching process, it is preferable to perform pickling (third desmut process) in order to remove dirt (smut) remaining on the surface. Since the third desmut process is basically the same as the first desmut process, only the differences will be described below.
In the third desmutting treatment, it is preferable to use an acidic solution containing 5-400 g / L acid and 0.5-8 g / L aluminum ions.
In the third desmut treatment, the treatment time is preferably 1 second or longer, more preferably 3 seconds or longer, and preferably 60 seconds or shorter, more preferably 15 seconds or shorter. .
In the third desmut process, when the same type of liquid as that used in the subsequent anodization process (for example, sulfuric acid) is used as the desmut process liquid, it is between the third desmut process and the anodization process. It is possible to omit liquid draining and rinsing with a nip roller.

<Anodizing treatment>
The aluminum plate treated as described above is preferably further subjected to an anodizing treatment. The anodizing treatment can be performed by a method conventionally used in this field. In this case, for example, in a solution having a sulfuric acid concentration of 50 to 300 g / L and an aluminum ion concentration of 5% by mass or less, an aluminum plate can be energized as an anode to form an anodized film. As a solution used for the anodizing treatment, sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, amidosulfonic acid and the like can be used alone or in combination of two or more.

  Under the present circumstances, the component normally contained at least in an aluminum plate, an electrode, tap water, groundwater, etc. may be contained in electrolyte solution. Furthermore, the 2nd, 3rd component may be added. Examples of the second and third components herein include metal ions such as Na, K, Mg, Li, Ca, Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn; Cation such as ammonium ion; anion such as nitrate ion, carbonate ion, chloride ion, phosphate ion, fluoride ion, sulfite ion, titanate ion, silicate ion, borate ion, etc., 0 to 10,000 ppm It may be contained at a concentration of about.

The conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be determined unconditionally. In general, however, the electrolyte concentration is 1 to 80% by mass, the solution temperature is 5 to 70 ° C., and the current density is 0.5. ˜60 A / dm ² , voltage 1 to 100 V, and electrolysis time 15 seconds to 50 minutes are appropriate and adjusted so as to obtain a desired anodic oxide film amount.

  Further, JP-A-54-81133, JP-A-57-47894, JP-A-57-51289, JP-A-57-51290, JP-A-57-54300, JP-A-57-136596, JP-A-58-107498, JP-A-60-200366, JP-A-62-136696, JP-A-63-176494, JP-A-4-17697, JP-A-4-280997, JP-A-6-280997 The methods described in JP-A-207299, JP-A-5-24377, JP-A-5-32083, JP-A-5-125597, JP-A-5-195291 and the like can also be used.

  Of these, as described in JP-A-54-12853 and JP-A-48-45303, it is preferable to use a sulfuric acid solution as the electrolytic solution. The sulfuric acid concentration in the electrolytic solution is preferably 10 to 300 g / L (1 to 30% by mass), more preferably 50 to 200 g / L (5 to 20% by mass), and the aluminum ion concentration. Is preferably 1 to 25 g / L (0.1 to 2.5% by mass), more preferably 2 to 10 g / L (0.2 to 1% by mass). Such an electrolytic solution can be prepared, for example, by adding aluminum sulfate or the like to dilute sulfuric acid having a sulfuric acid concentration of 50 to 200 g / L.

  The composition management of the electrolytic solution is performed using the same method as in the first electrochemical surface roughening treatment described above, and the conductivity, specific gravity and temperature corresponding to the matrix of sulfuric acid concentration and aluminum ion concentration, or It is preferable to control the electrical conductivity, the ultrasonic wave propagation speed, and the temperature.

  The liquid temperature of the electrolytic solution is preferably 25 to 55 ° C, and more preferably 30 to 50 ° C.

When anodizing is performed in an electrolytic solution containing sulfuric acid, direct current may be applied between the aluminum plate and the counter electrode, or alternating current may be applied.
When a direct current is applied to the aluminum plate, the current density is preferably from 1 to 60 A / dm ^2, and more preferably 5 to 40 A / dm ^2.
In the case of continuous anodizing treatment, at the beginning of anodizing treatment, so that current is concentrated on a part of the aluminum plate and so-called “burning” (part where the film becomes thicker than the surroundings) does not occur. It is preferable to increase the current density to 30 to 50 A / dm ² or higher as the anodic oxidation process proceeds with a current flowing at a low current density of 5 to 10 A / m ² .
Specifically, it is preferable that the current distribution of the DC power supply is set so that the current of the downstream DC power supply is equal to or greater than the current of the upstream DC power supply. By using such current distribution, so-called burning is less likely to occur, and as a result, high-speed anodization can be performed.

When the anodizing treatment is continuously performed, it is preferable that the anodizing process is performed by a liquid power feeding method in which power is supplied to the aluminum plate through an electrolytic solution.
By performing anodizing treatment under such conditions, a porous film having many pores called micropores can be obtained. Usually, the average pore diameter is about 5 to 50 nm, and the average pore density is 300. ˜800 / μm ² or so.

The amount of the anodized film is preferably 1 to 5 g / m ² . If it is less than 1 g / m ² , the plate is likely to be scratched. On the other hand, if it exceeds 5 g / m ² , a large amount of power is required for production, which is economically disadvantageous. The amount of the anodized film is more preferably 1.5 to 4 g / m ² . Moreover, it is preferable to carry out so that the difference in the amount of the anodized film between the center portion of the aluminum plate and the vicinity of the edge portion is 1 g / m ² or less.

As electrolysis apparatuses used for anodizing treatment, those described in JP-A-48-26638, JP-A-47-18739, JP-B-58-24517, JP-A-2001-11698, etc. Can be used.
Among these, the apparatus shown in FIG. 5 is preferably used. FIG. 5 is a schematic view showing an example of an apparatus for anodizing the surface of an aluminum plate.

  In the anodizing apparatus 410 shown in FIG. 5, in order to energize the aluminum plate 416 via the electrolytic solution, a feeding tank 412 is provided on the upstream side in the traveling direction of the aluminum plate 416 and an anodizing tank 414 is provided on the downstream side. It is installed. The aluminum plate 416 is conveyed by the pass rollers 422 and 428 as indicated by arrows in FIG. In the feed tank 412 into which the aluminum plate 416 is first introduced, an anode 420 connected to the positive electrode of the DC power supply 434 is installed, and the aluminum plate 416 serves as a cathode. Therefore, a cathode reaction occurs in the aluminum plate 416.

In the anodizing tank 414 into which the aluminum plate 416 is subsequently introduced, a cathode 430 connected to the negative electrode of the DC power source 434 is installed, and the aluminum plate 416 serves as an anode. Therefore, an anodic reaction occurs in the aluminum plate 416, and an anodic oxide film is formed on the surface of the aluminum plate 416.
The distance between the aluminum plate 416 and the cathode 430 is preferably 50 to 200 mm. Aluminum is used as the cathode 430. The cathode 430 is preferably not an electrode having a large area but an electrode divided into a plurality of pieces in the traveling direction of the aluminum plate 416 so that hydrogen gas generated by the anode reaction can be easily released from the system. .

  Between the power supply tank 412 and the anodizing tank 414, it is preferable to provide a tank called an intermediate tank 413 in which the electrolytic solution does not accumulate as shown in FIG. By providing the intermediate tank 413, current can be prevented from bypassing from the anode 420 to the cathode 430 without passing through the aluminum plate 416. It is preferable to reduce the bypass current as much as possible by installing a nip roller 424 in the intermediate tank 413 to drain the liquid. The electrolyte discharged by draining is discharged out of the anodizing apparatus 410 from the drain port 442.

  The electrolyte solution 418 stored in the power supply tank 412 has a higher temperature and / or higher concentration than the electrolyte solution 426 stored in the anodizing tank 414 in order to reduce voltage loss. In addition, the composition, temperature, and the like of the electrolytic solutions 418 and 426 are determined from the formation efficiency of the anodized film, the micropore shape of the anodized film, the hardness of the anodized film, the voltage, the cost of the electrolytic solution, and the like.

  Electrolyte is ejected from the liquid supply nozzles 436 and 438 and supplied to the power supply tank 412 and the anodizing treatment tank 414. For the purpose of keeping the distribution of the electrolyte constant and preventing local current concentration of the aluminum plate 416 in the anodizing tank 414, the liquid supply nozzles 436 and 438 are provided with slits, and the liquid flow to be ejected in the width direction. It has a constant structure.

  In the anodizing bath 414, a shielding plate 440 is provided on the opposite side of the aluminum plate 416 from the anode 430, and current flows to the opposite side of the surface of the aluminum plate 416 where the anodized film is to be formed. Deter. The distance between the aluminum plate 416 and the shielding plate 440 is preferably 5 to 30 mm. It is preferable to use a plurality of DC power supplies 434 and connect the positive electrode sides in common. Thereby, the current distribution in the anodizing bath 414 can be controlled.

  Further, the anodizing apparatus shown in FIG. 6 is obtained by connecting the two anodizing apparatuses shown in FIG. 5 in series.

<Sealing treatment>
In this invention, you may perform the sealing process which seals the micropore which exists in an anodic oxide film as needed. The sealing treatment can be performed according to a known method such as boiling water treatment, hot water treatment, steam treatment, sodium silicate treatment, nitrite treatment, ammonium acetate treatment and the like. For example, even if the sealing treatment is carried out by the apparatus and method described in JP-B-56-12518, JP-A-4-4194, JP-A-5-20296, JP-A-5-179482, etc. Good.

<Hydrophilic treatment>
It is preferable to perform a hydrophilic treatment after the anodizing treatment or the sealing treatment.
Examples of the hydrophilization treatment include treatment with potassium fluorozirconate described in US Pat. No. 2,946,638 and phosphomolybdate described in US Pat. No. 3,201,247. Treatment, alkyl titanate treatment described in British Patent 1,108,559, polyacrylic acid treatment described in German Patent 1,091,433, German Patent 1,134, No. 093 and British Patent No. 1,230,447, polyvinylphosphonic acid treatment, Japanese Patent Publication No. 44-6409, phosphonic acid treatment, US Pat. No. 3,307,951 Phytic acid treatment described in the specification of JP, No. 58-16893 and JP-A No. 58-18291 Treatment with a salt of a molecular compound and a divalent metal, as described in US Pat. No. 3,860,426, hydrophilic cellulose (eg, zinc acetate) containing a water-soluble metal salt (eg, zinc acetate) Carboxymethyl cellulose) is provided with a primer layer, and a water-soluble polymer having a sulfo group described in JP-A-59-101651.

Further, phosphates described in JP-A No. 62-019494, water-soluble epoxy compounds described in JP-A No. 62-033692, and JP-A No. 62-097892 Phosphoric acid modified starch, diamine compounds described in JP-A-63-056498, inorganic acid salts or organic acid salts of amino acids described in JP-A-63-130391, JP-A-63-145092 An organic phosphonic acid containing a carboxy group or a hydroxy group described in JP-A No. 63-165183, a compound having an amino group and a phosphonic acid group described in JP-A No. 63-165183, described in JP-A No. 2-316290 Specific carboxylic acid derivatives, phosphoric acid esters described in JP-A-3-215095, JP-A-3-2615 Compound having one amino group and one oxygen acid group of phosphorus described in Japanese Patent No. 2, phosphoric acid ester described in Japanese Patent Laid-Open No. 3-215095, and Japanese Patent Laid-Open No. 5-246171 Aliphatic or aromatic phosphonic acids such as phenylphosphonic acid, compounds containing S atoms such as thiosalicylic acid described in JP-A-1-307745, and JP-A-4-282737 Examples of the treatment include undercoating using a compound having a group of phosphorus oxyacids.
Further, coloring with an acid dye described in JP-A-60-64352 can also be performed.

  Hydrophilicity can also be achieved by soaking in an aqueous solution of an alkali metal silicate such as sodium silicate or potassium silicate, or by applying a hydrophilic vinyl polymer or hydrophilic compound to form a hydrophilic primer layer. It is preferable to carry out the treatment.

Hydrophilization treatment with an aqueous solution of an alkali metal silicate such as sodium silicate and potassium silicate is described in US Pat. No. 2,714,066 and US Pat. No. 3,181,461. It can be performed according to methods and procedures.
Examples of the alkali metal silicate include sodium silicate, potassium silicate, and lithium silicate. No. 1 sodium silicate or No. 3 sodium silicate is preferably used, and No. 1 sodium silicate is used. Is more preferable.
When No. 1 sodium silicate is used in the aqueous solution used for the hydrophilization treatment, the concentration of No. 1 sodium silicate is preferably 1 to 10% by mass, and the liquid temperature is preferably 10 to 30 ° C. The treatment time is preferably 1 to 15 seconds.

The aqueous solution of alkali metal silicate may contain an appropriate amount of sodium hydroxide, potassium hydroxide, lithium hydroxide, or the like.
The aqueous solution of alkali metal silicate may contain an alkaline earth metal salt or a Group 4 (Group IVA) metal salt. Examples of the alkaline earth metal salt include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate; sulfates; hydrochlorides; phosphates; acetates; oxalates; Examples of Group 4 (Group IVA) metal salts include titanium tetrachloride, titanium trichloride, potassium fluoride titanium, potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium tetrachloride. Is mentioned. These alkaline earth metal salts and Group 4 (Group IVA) metal salts are used alone or in combination of two or more.

The amount of Si adsorbed by the alkali metal silicate treatment can be measured by a fluorescent X-ray analyzer, and the amount adsorbed is preferably about 1.0 to 10.0 mg / m ² , and 3 to 10 mg / m 2. ² is more preferable. When the amount of adsorbed Si is 3 to 10 mg / m ² , the stain resistance of the halftone dot portion is improved.
More specifically, in the shadow portion (halftone dot portion) of the printed matter, the area ratio of the halftone dots is high (70 to 90%), and in the area corresponding to that of the planographic printing plate, the image portion (image recording layer) The area is large, and the area of the non-image part (exposed part of the support) is relatively small. In such a case, at the time of printing, the inks placed on the adjacent image portions come into contact with each other (that is, entangled), the ink adheres to the non-image portions therebetween, and the non-image portions of the printed material are crushed ( In other words, the phenomenon of contamination) is likely to occur.
However, the hydrophilicity of the non-image area is improved by performing hydrophilic treatment so that the amount of Si adhering to the surface of the lithographic printing plate support is 3 to 10 mg / m ^2. When a lithographic printing plate is prepared using a plate support and printing is performed, the stain resistance of the halftone dot portion can be improved.

  By the alkali metal silicate treatment described above, the effect of improving the dissolution resistance to the alkali developer on the surface of the lithographic printing plate support is obtained, and the elution of the aluminum component into the developer is suppressed. It is possible to reduce the occurrence of development debris due to fatigue.

The hydrophilic treatment by forming a hydrophilic undercoat layer can also be performed according to the conditions and procedures described in JP-A Nos. 59-101651 and 60-149491.
Examples of the hydrophilic vinyl polymer used in this method include polyvinyl sulfonic acid, sulfo group-containing vinyl polymerizable compounds such as p-styrene sulfonic acid having a sulfo group, and ordinary vinyl polymerization such as (meth) acrylic acid alkyl ester. And a copolymer with a functional compound. Examples of the hydrophilic compound used in this method include compounds having at least one selected from the group consisting of -NH2 group, -COOH group and sulfo group.

<Drying>
After obtaining the lithographic printing plate support as described above, it is preferable to dry the surface of the lithographic printing plate support before providing the image recording layer. Drying is preferably performed after the final treatment of the surface treatment, after washing with water and draining with a nip roller.
The drying temperature is preferably 70 ° C or higher, more preferably 80 ° C or higher, preferably 110 ° C or lower, more preferably 100 ° C or lower.
The drying time is preferably 2 to 15 seconds.

<Management of liquid composition>
In the present invention, it is preferable to manage the composition of various processing solutions used for the surface treatment described above by the method described in JP-A-2001-121837. Prepare a large number of treatment liquid samples with various concentrations in advance, measure the propagation speed of ultrasonic waves at two liquid temperatures, create a matrix data table, It is preferable to measure the propagation speed of the light in real time and control the concentration based on the measurement. In particular, in the desmutting treatment, when an electrolytic solution having a sulfuric acid concentration of 250 g / L or more is used, it is preferable to control the concentration by the method described above.
In addition, it is preferable that each electrolyte solution used for an electrolytic roughening process and an anodic oxidation process is 100 ppm or less of Cu concentration. If the Cu concentration is too high, Cu is deposited on the aluminum plate when the line is stopped, and Cu deposited when the line is operated again may be transferred to a pass roll, which may cause processing unevenness.

[Lithographic printing plate precursor]
The lithographic printing plate support obtained by the present invention can be provided with an image recording layer to form the lithographic printing plate precursor of the present invention. A photosensitive composition is used for the image recording layer.
Examples of the photosensitive composition suitably used in the present invention include a thermal positive photosensitive composition containing an alkali-soluble polymer compound and a photothermal conversion substance (hereinafter, this composition and an image recording layer using the same). ), A thermal negative photosensitive composition containing a curable compound and a photothermal conversion substance (hereinafter also referred to as “thermal negative type”), a photopolymerizable photosensitive composition (hereinafter referred to as “thermal positive type”). , Also referred to as “photopolymer type”), negative photosensitive composition containing diazo resin or photocrosslinking resin (hereinafter also referred to as “conventional negative type”), and positive photosensitive composition containing quinonediazide compound. Product (hereinafter also referred to as “conventional positive type”), a photosensitive composition that does not require a special development step (hereinafter referred to as “the conventional positive type”). As the referred to as "non-treatment type".), And the like. Hereinafter, these suitable photosensitive compositions will be described.

<Thermal positive type>
<Photosensitive layer>
The thermal positive type photosensitive composition contains an alkali-soluble polymer compound and a photothermal conversion substance. In the thermal positive type image recording layer, the photothermal conversion substance converts the energy of light such as infrared lasers into heat, which effectively eliminates the interaction that reduces the alkali solubility of alkali-soluble polymer compounds. To do.

Examples of the alkali-soluble polymer compound include a resin containing an acidic group in the molecule and a mixture of two or more thereof. In particular, a phenolic hydroxy group, sulfonamide group (in -SO ₂ NH-R (wherein, R represents a hydrocarbon group.)), Active imino group _{(-SO 2 NHCOR, -SO 2 NHSO} 2 R, -CONHSO A resin having an acidic group such as ₂ R (wherein R has the same meaning as described above) is preferable in terms of solubility in an alkali developer.
In particular, a resin having a phenolic hydroxy group is preferable in that it has excellent image-forming properties when exposed to light such as an infrared laser, and examples thereof include phenol-formaldehyde resins, m-cresol-formaldehyde resins, p-cresol-formaldehyde resins, m- / p-mixed cresol-formaldehyde resin, phenol / cresol (any of m-, p- and m- / p-mixed) mixed-formaldehyde resin (phenol-cresol-formaldehyde co-condensation resin) and other novolak resins Are preferable.
Furthermore, the polymer compound described in JP-A No. 2001-305722 (particularly [0023] to [0042]), and the repetition represented by the general formula (1) described in JP-A No. 2001-215893 Preferred examples also include polymer compounds containing units, and polymer compounds described in JP-A No. 2002-311570 (particularly [0107]).

  Preferable examples of the photothermal conversion substance include pigments or dyes having a light absorption region in the infrared region having a wavelength of 700 to 1200 nm in terms of recording sensitivity. Examples of the dye include azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes (for example, , Nickel thiolate complex). Among these, cyanine dyes are preferable, and cyanine dyes represented by the general formula (I) described in JP 2001-305722 A are particularly preferable.

The thermal positive type photosensitive composition may contain a dissolution inhibitor. As the dissolution inhibitor, for example, dissolution inhibitors described in JP-A-2001-305722, [0053] to [0055] are preferably exemplified.
In addition, in the thermal positive type photosensitive composition, as a additive, a sensitivity modifier, a printing agent for obtaining a visible image immediately after heating by exposure, a compound such as a dye as an image colorant, a coating property In addition, it is preferable to include a surfactant for improving the processing stability. For these, compounds described in JP-A-2001-305722, [0056] to [0060] are preferable.
The photosensitive composition described in detail in Japanese Patent Application Laid-Open No. 2001-305722 is also preferably used in other respects.

Further, the thermal positive type image recording layer is not limited to a single layer but may have a two-layer structure.
As an image recording layer having a two-layer structure (multilayer image recording layer), a lower layer (hereinafter referred to as “A layer”) having excellent printing durability and solvent resistance is provided on the side close to the support, and a positive layer is provided thereon. A type provided with a layer having excellent image formability (hereinafter referred to as “B layer”) is preferable. This type has high sensitivity and can realize a wide development latitude. The B layer generally contains a photothermal conversion substance. Preferred examples of the photothermal conversion substance include the dyes described above.
As the resin used in the A layer, a polymer having a monomer having a sulfonamide group, an active imino group, a phenolic hydroxy group or the like as a copolymerization component is preferably used because it has excellent printing durability and solvent resistance. . As the resin used for the B layer, an alkaline aqueous solution-soluble resin having a phenolic hydroxy group is preferably exemplified.
In addition to the resin, the composition used for the A layer and the B layer can contain various additives as necessary. Specifically, various additives as described in JP-A-2002-323769, [0062] to [0085] are preferably used. Further, the additives described in [0053] to [0060] of JP-A-2001-305722 described above are also preferably used.
About each component which comprises A layer and B layer, and its content, it is preferable to make it describe in Unexamined-Japanese-Patent No. 11-218914.

<Intermediate layer>
An intermediate layer is preferably provided between the thermal positive type image recording layer and the support. As the component contained in the intermediate layer, various organic compounds described in [0068] of JP-A No. 2001-305722 are preferably exemplified.

<Others>
As a method for producing a thermal positive type image recording layer and a plate making method, methods described in detail in JP-A No. 2001-305722 can be used.

<Thermal negative type>
The thermal negative photosensitive composition contains a curable compound and a photothermal conversion substance. The thermal negative type image recording layer is a negative photosensitive layer in which a portion irradiated with light such as an infrared laser is cured to form an image portion.
<Polymerized layer>
As one of the thermal negative type image recording layers, a polymerization type image recording layer (polymerization layer) is preferably exemplified. The polymerization layer contains a photothermal conversion substance, a radical generator, a radical polymerizable compound that is a curable compound, and a binder polymer. In the polymerization layer, infrared light absorbed by the light-to-heat conversion substance is converted into heat, the radical generator is decomposed by this heat to generate radicals, and the radical polymerizable compound is polymerized in a chain by the generated radicals and cured. .

As a photothermal conversion substance, the photothermal conversion substance used for the thermal positive type mentioned above is mentioned, for example. Specific examples of particularly preferred cyanine dyes include those described in JP-A-2001-133969, [0017] to [0019].
Preferred examples of the radical generator include onium salts. In particular, onium salts described in JP-A-2001-133969, [0030] to [0033] are preferable.
Examples of the radical polymerizable compound include compounds having at least one terminal ethylenically unsaturated bond, preferably two or more.
As the binder polymer, a linear organic polymer is preferably exemplified. Preferred examples include linear organic polymers that are soluble or swellable in water or weak alkaline water. Among them, a (meth) acrylic resin having an unsaturated group such as an allyl group or an acryloyl group or a benzyl group and a carboxy group in the side chain is preferable in that it has an excellent balance of film strength, sensitivity, and developability. .
As the radical polymerizable compound and the binder polymer, those described in detail in [0036] to [0060] of JP-A No. 2001-133969 can be used.

  The additive described in [0061] to [0068] of JP-A No. 2001-133969 is contained in the thermal negative photosensitive composition (for example, a surfactant for improving coatability). Is preferred.

  As a method for producing the polymerization layer and a plate making method, methods described in detail in JP-A No. 2001-133969 can be used.

<Acid cross-linked layer>
Further, as one of the thermal negative type image recording layers, an acid cross-linked image recording layer (acid cross-linked layer) is also preferably exemplified. The acid cross-linking layer comprises a photothermal conversion substance, a thermal acid generator, a compound that cross-links with an acid that is a curable compound (cross-linking agent), and an alkali-soluble polymer compound that can react with the cross-linking agent in the presence of an acid. contains. In the acid cross-linking layer, infrared light absorbed by the photothermal conversion substance is converted into heat, the heat acid generator is decomposed by this heat to generate an acid, and the generated acid reacts with the cross-linking agent and the alkali-soluble polymer compound. And harden.

Examples of the photothermal conversion substance include the same substances as those used for the polymerization layer.
Examples of the thermal acid generator include thermal decomposition compounds such as photoinitiators for photopolymerization, photochromic agents for dyes, and acid generators used in microresists.
Examples of the crosslinking agent include an aromatic compound substituted with a hydroxymethyl group or an alkoxymethyl group; a compound having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group; and an epoxy compound.
Examples of the alkali-soluble polymer compound include a novolak resin and a polymer having a hydroxyaryl group in the side chain.

<Photopolymer type>
The photopolymerization type photosensitive composition contains an addition polymerizable compound, a photopolymerization initiator, and a polymer binder.
As the addition polymerizable compound, an ethylenically unsaturated bond-containing compound capable of addition polymerization is preferably exemplified. The ethylenically unsaturated bond-containing compound is a compound having a terminal ethylenically unsaturated bond. Specifically, for example, it has a chemical form such as a monomer, a prepolymer, and a mixture thereof. Examples of monomers include esters of unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, maleic acid) and aliphatic polyhydric alcohol compounds, amides of unsaturated carboxylic acids and aliphatic polyvalent amine compounds. Is mentioned.
Moreover, as an addition polymerizable compound, a urethane type addition polymerizable compound is also preferably exemplified.

As the photopolymerization initiator, various photopolymerization initiators or a combination system (photoinitiation system) of two or more kinds of photopolymerization initiators can be appropriately selected depending on the wavelength of the light source to be used. For example, an initiation system described in JP-A-2001-22079, [0021] to [0023] is preferably exemplified.
The polymer binder not only functions as a film-forming agent for the photopolymerization type photosensitive composition, but is soluble or swellable in alkaline water because it is necessary to dissolve the image recording layer in an alkaline developer. An organic high molecular polymer is used. As such an organic polymer, those described in JP-A-2001-22079, [0036] to [0063] are preferably exemplified.

  In the photopolymer type photopolymerization type photosensitive composition, additives described in JP-A-2001-22079, [0079] to [0088] (for example, a surfactant for improving coatability) , Colorants, plasticizers, thermal polymerization inhibitors).

Further, it is preferable to provide an oxygen-blocking protective layer on the photopolymer type image recording layer in order to prevent the action of inhibiting the polymerization of oxygen. Examples of the polymer contained in the oxygen barrier protective layer include polyvinyl alcohol and copolymers thereof.
Furthermore, it is also preferable to provide an intermediate layer or an adhesive layer as described in [0124] to [0165] of JP-A-2001-228608.

<Conventional negative type>
The conventional negative-type photosensitive composition contains a diazo resin or a photocrosslinking resin. Among these, a photosensitive composition containing a diazo resin and an alkali-soluble or swellable polymer compound (binder) is preferable.
Examples of the diazo resin include a condensate of an aromatic diazonium salt and an active carbonyl group-containing compound such as formaldehyde; a condensate of p-diazophenylamines and formaldehyde and a hexafluorophosphate or a tetrafluoroborate. Organic solvent-soluble diazo resin inorganic salts which are reaction products of In particular, a high molecular weight diazo compound containing 20 mol% or more of a hexamer described in JP-A-59-78340 is preferable.
Examples of the binder include a copolymer containing acrylic acid, methacrylic acid, crotonic acid, or maleic acid as an essential component. Specifically, a multi-component copolymer of monomers such as 2-hydroxyethyl (meth) acrylate, (meth) acrylonitrile, (meth) acrylic acid as described in JP-A-50-118802, Examples thereof include multi-component copolymers composed of alkyl acrylate, (meth) acrylonitrile and unsaturated carboxylic acid as described in JP-A-56-4144.

  The conventional negative type photosensitive composition has, as an additive, a printing agent, dye, and flexibility and abrasion resistance described in JP-A-7-281425, [0014] to [0015]. It is preferable to contain a plasticizer for imparting, a compound such as a development accelerator, and a surfactant for improving coating properties.

  Under the conventional negative type photosensitive layer, an intermediate layer containing a polymer compound having a component having an acid group and a component having an onium group as described in JP-A-2000-105462 is provided. Is preferred.

<Conventional positive type>
The conventional positive-type photosensitive composition contains a quinonediazide compound. Among these, a photosensitive composition containing an o-quinonediazide compound and an alkali-soluble polymer compound is preferable.
Examples of the o-quinonediazide compound include esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and phenol-formaldehyde resin or cresol-formaldehyde resin, described in US Pat. No. 3,635,709. And esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and pyrogallol-acetone resin.
Examples of the alkali-soluble polymer compound include phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde co-condensation resin, polyhydroxystyrene, N- (4-hydroxyphenyl) methacrylamide copolymer, A carboxy group-containing polymer described in JP-A-7-36184, an acrylic resin containing a phenolic hydroxy group as described in JP-A-51-34711, and described in JP-A-2-866 Examples thereof include acrylic resins having a sulfonamide group and urethane resins.

  Conventional positive type photosensitive compositions include compounds such as sensitivity modifiers, printing agents, dyes and the like described in JP-A-7-92660, [0024] to [0027] as additives. It is preferable to contain a surfactant for improving the coating property as described in [0031] of Kaihei 7-92660.

  Under the conventional positive type photosensitive layer, it is preferable to provide an intermediate layer similar to the intermediate layer suitably used for the above-described conventional negative type.

<Non-treatment type>
Examples of the non-processing type photosensitive composition include a thermoplastic fine particle polymer type, a microcapsule type, and a sulfonic acid-generating polymer-containing type. These are all heat-sensitive types containing a photothermal conversion substance. The photothermal conversion substance is preferably the same dye as that used in the above-described thermal positive type.

The thermoplastic fine particle polymer type photosensitive composition is obtained by dispersing a hydrophobic and heat-meltable fine particle polymer in a hydrophilic polymer matrix. In the image recording layer of the thermoplastic fine particle polymer type, the hydrophobic fine particle polymer is melted by heat generated by exposure and is fused to form a hydrophobic region, that is, an image portion.
As the fine particle polymer, those in which fine particles melt and coalesce with heat are preferable, and those having a hydrophilic surface and capable of being dispersed in a hydrophilic component such as dampening water are more preferable. Specifically, Research Disclosure No. 33303 (January 1992), JP-A-9-123387, JP-A-9-131850, JP-A-9-171249, and JP-A-9-171250, and European Patent Application Publication No. 931,647. Preferred examples thereof include thermoplastic fine particle polymers. Of these, polystyrene and polymethyl methacrylate are preferred. Examples of the fine particle polymer having a hydrophilic surface include those in which the polymer itself is hydrophilic; those in which a hydrophilic compound such as polyvinyl alcohol and polyethylene glycol is adsorbed on the surface of the fine particle polymer to make the surface hydrophilic.
The fine particle polymer preferably has a reactive functional group.

  As a microcapsule type photosensitive composition, a compound having a heat-reactive functional group as described in JP-A No. 2000-118160 or JP-A No. 2001-277740 is included. A microcapsule type is preferable.

  Examples of the sulfonic acid generating polymer used in the sulfonic acid generating polymer-containing photosensitive composition include sulfonic acid ester groups, disulfone groups, and sec- or tert-sulfonamides described in JP-A No. 10-282672. Examples thereof include polymers having a group in the side chain.

  By incorporating a hydrophilic resin into the unprocessed photosensitive composition, not only on-press developability is improved, but also the film strength of the photosensitive layer itself is improved. Examples of the hydrophilic resin include those having a hydrophilic group such as hydroxy group, carboxy group, hydroxyethyl group, hydroxypropyl group, amino group, aminoethyl group, aminopropyl group, carboxymethyl group, and hydrophilic sol-gel conversion system. A binder resin is preferred.

  The unprocessed type image recording layer does not require a special development step and can be developed on a printing press. As a method for producing an unprocessed image recording layer and a plate-making printing method, methods described in detail in JP-A No. 2002-178655 can be used.

<Back coat>
In this way, the backside of the lithographic printing plate precursor of the present invention obtained by providing various image recording layers on the lithographic printing plate support obtained by the present invention, if necessary, is an image in the case of overlapping. In order to prevent the recording layer from being damaged, a coating layer made of an organic polymer compound can be provided.

[Plate making method (lithographic printing plate production method)]
The lithographic printing plate precursor using the lithographic printing plate support obtained by the present invention is converted into a lithographic printing plate by various treatment methods according to the image recording layer.
Examples of the actinic ray light source used for image exposure include a mercury lamp, a metal halide lamp, a xenon lamp, and a chemical lamp. Examples of the laser beam include helium-neon laser (He-Ne laser), argon laser, krypton laser, helium-cadmium laser, KrF excimer laser, semiconductor laser, YAG laser, and YAG-SHG laser.

After the above exposure, if the image recording layer is one of a thermal positive type, a thermal negative type, a conventional negative type, a conventional positive type, and a photopolymer type, it is exposed and then developed using a developer to obtain a lithographic printing plate. It is preferable to obtain.
The developer is preferably an alkaline developer, and more preferably an alkaline aqueous solution substantially free of an organic solvent.
Moreover, the developing solution which does not contain alkali metal silicate substantially is also preferable. As a method of developing using a developer substantially not containing an alkali metal silicate, a method described in detail in JP-A No. 11-109637 can be used.
A developer containing an alkali metal silicate can also be used.

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these.
<Example for the first aspect of the present invention>
1-1. Preparation of lithographic printing plate support (Examples 1-1 to 1-41 and 2-1 to 2-43)
In Examples 1-1 to 1-41 and 2-1 to 2-43, a molten metal was prepared using an aluminum alloy having the composition shown in Table 1 (the balance being aluminum and inevitable impurities. The unit is mass%). After performing the molten metal treatment and filtration, an ingot having a thickness of 500 mm and a width of 1200 mm was produced by a DC casting method. After the surface was shaved with a chamfering machine with an average thickness of 10 mm, it was kept soaked at 550 ° C. for about 5 hours, and when the temperature dropped to 400 ° C., rolling with a thickness of 2.7 mm using a hot rolling mill A board was used. Furthermore, after performing heat processing at 500 degreeC using a continuous annealing machine, it finished by cold rolling to 0.3 mm in thickness and 1060 mm in width, and obtained the aluminum plate.

  Next, the following process was performed using this aluminum plate.

<Surface treatment>
Next, surface treatment was performed by continuously performing the following various treatments (a) to (k).

(A) Mechanical surface roughening treatment A slurry of abrasive and water (specific gravity 1.12) obtained by crushing pumice and classifying the particles so that the average particle size of the particles is 30 μm is a polishing slurry. As described above, mechanical surface roughening was performed with a rotating roller-like nylon brush while supplying the aluminum plate surface with a spray tube.
Mohs hardness of the abrasive is 5, as an abrasive, a SiO ₂ 73 wt%, Al ₂ O ₃ of 14 wt%, Fe ₂ O ₃ 1.2 wt%, 1.34 wt% of CaO, MgO Containing 0.3 mass%, K ₂ O 2.6 mass%, and Na ₂ O 2.7 mass% were used.
Nylon brush, material 6 · 10 nylon, hair length 50mm (before flocking), No. 3 brush with bristles diameter 0.295mm, holed in a stainless steel tube of φ300mm and planted so as to be dense 3 Used this book.
The distance between the two support rollers (φ200 mm) below the nylon brush was 300 mm, and the rotation direction of the nylon brush was the same as the moving direction of the aluminum plate.
The pushing amount of the nylon brush was adjusted by managing the load of the drive motor that rotates the nylon brush.
The mechanical graining treatment, so that the average surface roughness R _a of the aluminum plate after processing becomes 0.25～0.40Myuemu, the flow rate of the abrasive, the rotational speed of the brush, the moving speed of the aluminum plate or the like Was adjusted appropriately. It shows the average surface roughness R _a of the aluminum plate after mechanical graining treatment in Table 2.

Here, the average surface roughness R _a of the aluminum plate, stylus roughness meter (Surfcom575, manufactured by Tokyo Seimitsu Co., Ltd.) subjected to two-dimensional roughness measurement, the 5 times an average surface roughness as defined in ISO4287 The average value was measured.
The conditions for the two-dimensional roughness measurement are shown below.
<Measurement conditions>
Cut-off value 0.8mm, tilt correction FLAT-ML, measurement length 3mm, vertical magnification 10,000 times, scanning speed 0.3mm / sec, stylus tip diameter 2μm

(B) Etching treatment in alkaline aqueous solution (first etching treatment)
The aluminum plate was sprayed with an aqueous solution having a sodium hydroxide concentration of 27% by mass, an aluminum ion concentration of 6.5% by mass, and a temperature of 70 ° C. from the spray tube to perform an etching process. Table 2 shows the etching amount of the surface subjected to the first electrochemical roughening treatment after the aluminum plate.
Thereafter, the liquid was drained with a nip roller, and further, a water washing treatment described later was performed, and then the liquid was drained with a nip roller. The water washing treatment was carried out using an apparatus for washing with a free-falling curtain-like liquid film, and further washed with water for 5 seconds using a spray tube having a structure having spray chips with fan-spray spread at 80 mm intervals. .

(C) Desmut treatment in acidic aqueous solution (first desmut treatment)
Next, a desmut treatment was performed. As the acidic aqueous solution used for the desmut treatment, the waste liquid generated in the first electrochemical surface roughening step described later was used.
The desmut treatment was performed by spraying the acidic aqueous solution (liquid temperature 35 ° C.) from the spray tube for 5 seconds.
Thereafter, the liquid was drained with a nip roller.

(D) First electrochemical surface roughening treatment Next, a first electrochemical surface roughening treatment was performed using an electrolytic solution having a nitric acid concentration, an aluminum ion concentration, and a liquid temperature shown in Table 2. The aluminum ion concentration was adjusted by adding aluminum nitrate. The ammonium ion concentration was 70 mg / L.
An electrochemical surface roughening process was performed using a power source that generates an alternating current having an arbitrary waveform, which is current-controlled by PWM control using an IGBT element.
A carbon electrode was used as the counter electrode, and an iridium oxide electrode was used as the auxiliary anode. As the electrolytic cell, two radial type cells as shown in FIG. 4 were used.
The time TP until the waveform, frequency and current value of the generated alternating current reached the peak from zero is as shown in Table 2, and the duty was 0.5. In addition, the current density during the anode reaction of the aluminum plate at the peak of the alternating current, the amount of electricity (the total amount of electricity during the anode reaction of the aluminum plate), and the current ratio r in the main electrolytic cell are as shown in Table 2. It was. The current ratio r was adjusted by the amount of current diverted to the auxiliary anode.
The aluminum plate was supplied into the main electrolytic cell so that the relative speed with respect to the electrolytic solution in the main electrolytic cell was 1 to 2 m / sec, and the average was 1.5 m / sec.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

(E) Etching treatment in alkaline aqueous solution (second etching treatment)
The aluminum plate was etched by spraying an aqueous solution having a caustic soda concentration of 27 mass%, an aluminum ion concentration of 5.5 mass%, and a temperature of 65 ° C. from a spray tube. Table 2 shows the etching amount of the surface subjected to the second electrochemical roughening treatment after the aluminum plate.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

(F) Desmut treatment in acidic aqueous solution (second desmut treatment)
Next, a desmut treatment was performed. As the acidic aqueous solution, an aqueous solution having a sulfuric acid concentration of 300 g / L and aluminum ions 1.5 g / L dissolved therein was used. The desmutting treatment was performed by spraying the acidic aqueous solution (liquid temperature: 60 ° C.) from a spray tube for 10 seconds.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

(G) Second electrochemical roughening treatment An electrolytic solution having a hydrochloric acid concentration and an aluminum ion concentration shown in Table 2 and a liquid temperature of 35 ° C. was used. The aluminum ion concentration was adjusted using aluminum chloride.
An electrochemical surface roughening process was performed using a power source that generates an alternating current having an arbitrary waveform, which is current-controlled using PWM control using an IGBT element.
A carbon electrode was used as the counter electrode, and an iridium oxide electrode was used as the auxiliary anode. As the electrolytic cell, one radial type cell as shown in FIG. 4 was used.
The waveform of the generated alternating current was a trapezoidal wave, the frequency was 60 Hz, the time TP until the current value reached the peak from zero was 0.8 msec, and the duty was 0.5. Current density during the anodic reaction of the aluminum plate at the peak of the AC is as shown in Table 2, the quantity of electricity is 63C / dm ^2, the current ratio was 0.95. The current ratio was adjusted by the amount of current diverted to the auxiliary anode. The aluminum plate was supplied into the main electrolytic cell so that the relative speed with respect to the electrolytic solution in the main electrolytic cell was 1 to 2 m / sec, and the average was 1.5 m / sec.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

(H) Etching treatment in alkaline aqueous solution (third etching treatment)
The aluminum plate was etched by spraying an aqueous solution of 5% by mass of sodium hydroxide, 0.5% by mass of aluminum ions, and a temperature of 35 ° C. from a spray tube. Table 2 shows the etching amount of the surface of the aluminum plate that has been subjected to the second electrochemical roughening treatment.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

(I) Desmutting treatment in acidic aqueous solution (third desmutting treatment)
Next, a desmut treatment was performed. As the acidic aqueous solution used for the desmutting treatment, the waste liquid generated in the anodizing treatment step (dissolved in aluminum acid at 5 g / L in sulfuric acid 170 g / L aqueous solution) was used. The desmut treatment was performed by spraying the acidic aqueous solution (liquid temperature 60 ° C.) for 5 seconds from the spray tube. Thereafter, the liquid was drained with a nip roller.

(J) Anodizing treatment Next, anodizing treatment was performed using an anodizing apparatus.
As the electrolytic solution, an electrolytic solution (temperature 33 ° C.) in which aluminum sulfate was dissolved in a 170 g / L sulfuric acid aqueous solution to make the aluminum ion concentration 5 g / L was used. The anodizing treatment was performed so that the average current density during the anodic reaction of the aluminum plate was 10 A / dm ² , and the final oxide film amount was 2.4 g / m ² .
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

(K) Hydrophilization treatment 1
The aluminum plate was immersed in 1.0 mass% aqueous solution of sodium silicate 3 (liquid temperature 20 ° C.) for 10 seconds. The amount of Si on the surface of the aluminum plate measured with a fluorescent X-ray analyzer was 3.5 mg / m ² .
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller. Then, 90 degreeC wind was blown for 10 seconds and it dried, and the support body for lithographic printing plates was obtained.

(Examples 1-42 to 1-44 and 2-44 to 2-47)
In Examples 1-42 to 1-44 and 2-44 to 2-47, Examples 1-1 to 1-1 were performed except that the process (l) described below was performed instead of the process (k). Surface treatment was performed in the same manner as in −41 and 2-1 to 2-43 to obtain a lithographic printing plate support.

(L) Hydrophilization treatment 2
The aluminum plate was immersed in a 4.0 mass% aqueous solution of sodium silicate No. 1 (liquid temperature 22 ° C.) for 8 seconds. The amount of Si on the surface of the aluminum plate measured with a fluorescent X-ray analyzer was 5.3 mg / m ² .
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller. Then, 90 degreeC wind was blown for 10 seconds and it dried, and the support body for lithographic printing plates was obtained.

(Comparative Example 1)
In Comparative Example 1, a lithographic printing plate was obtained by performing a surface treatment in the same manner as in Examples 1-1 to 1-41 and 2-1 to 2-43 except that (a) was not performed.

1-2. Observation of surface of lithographic printing plate support The surface of each lithographic printing plate support obtained in Examples 1-1 to 1-44 and 2-1 to 2-47 was scanned with a scanning electron microscope (JSM- 5500, manufactured by JEOL Ltd., the same shall apply hereinafter), the fine irregularities having an average opening diameter of 0.05 to 0.3 μm were generated uniformly and densely.
In addition, when observed at a magnification of 2000 using a scanning electron microscope, the surface of the lithographic printing plate support of Examples 1-1 to 1-44 and 2-1 to 2-47 has an average aperture diameter of 1 to 1. 6 μm irregularities (honeycomb pits) were uniformly formed.
Further, when each lithographic printing plate support was observed with an inclination angle of 30 °, a large concavo-convex structure (swell) having a pitch of 5 to 20 μm was formed.

1-3. After the measurement the second etching process having an average surface roughness R _a of the surface of the aluminum plate and the after anodizing treatment was measured an average surface roughness R _a of the surface of the aluminum plate, a as shown in Table 2 It was. Specifically, in Examples 1-1 to 1-44 and 2-1 to 2-47, the average surface roughness _Ra was in the range of 0.41 to 0.60, but in Comparative Example 1, the value of the average surface roughness R _a was small enough.
In addition, average surface roughness _Ra was measured by the same method as the method described in the above (a).

1-4. Preparation of lithographic printing plate precursor A lithographic printing plate precursor was obtained by providing each lithographic printing plate support obtained above with a thermal positive type image recording layer as follows.

On each of the lithographic printing plate supports obtained in Examples 1-1 to 1-41 and 2-41 to 2-43 and Comparative Example 1, first, an undercoat solution having the following composition was applied, and the mixture was coated at 15 ° C. at 15 ° C. The film was dried for 2 seconds to form a coating film of an undercoat layer. The coating amount of the coating film after drying was 15 mg / m ² .

<Undercoat liquid composition>
・ The following polymer compound 0.3g
・ Methanol 100g
・ Water 1g

Further, an image recording layer coating solution A having the following composition was prepared, and the coating amount (heat sensitive layer coating amount) after drying this image recording layer coating solution A was 1 on a lithographic printing plate support provided with an undercoat layer. It was applied to a thickness of 0.8 g / m ² and dried to form a thermal positive type image recording layer 1 to obtain a lithographic printing plate precursor.

<Image recording layer coating solution A composition>
Novolak resin (m-cresol / p-cresol = 60/40, weight average molecular weight 7,000, containing 0.5% by mass of unreacted cresol) 0.90 g
・ Ethyl methacrylate / isobutyl methacrylate / methacrylic acid copolymer (molar ratio 35/35/30) 0.10 g
-Cyanine dye A 0.1 g represented by the following structural formula
・ Tetrahydrophthalic anhydride 0.05g
・ 0.002 g of p-toluenesulfonic acid
-Ethyl violet counter ion with 6-hydroxy-β-naphthalenesulfonic acid 0.02 g
・ Fluorosurfactant (Megafac F-780F, manufactured by Dainippon Ink and Chemicals, solid content: 30% by mass) 0.0045 g (solid content conversion)
・ Fluorosurfactant (Megafac F-781F, manufactured by Dainippon Ink & Chemicals, Inc., solid content: 100% by mass) 0.035 g
・ Methyl ethyl ketone 12g

In addition, an undercoat solution having the following composition was first applied on each lithographic printing plate support obtained in Examples 1-42 to 1-44 and 2-44 to 2-47, and dried at 80 ° C. for 15 seconds. Then, a coating film of the undercoat layer was formed. The coating amount of the coating film after drying was 15 mg / m ² .

<Undercoat liquid composition>
・ The following polymer compound 0.3g
・ Methanol 100g
・ Water 1g

Next, an image recording layer coating solution B1 having the following composition was applied on the undercoat layer with a wire bar so as to be 0.85 g / m ² after drying, and dried at 140 ° C. for 50 seconds.
After that, the image recording layer coating liquid B2 having the following composition was applied with a wire bar so as to be 0.25 g / m ² after drying, and dried at 140 ° C. for 1 minute to form a multilayer thermal positive type image recording layer. 2 was obtained to obtain a lithographic printing plate precursor.

<Image Recording Layer Coating Liquid B1>
N- (4-aminosulfonylphenyl) methacrylamide / acrylonitrile / methyl methacrylate copolymer (molar ratio 36/34/30, weight average molecular weight 50,000) 1.920 g
-M, p-cresol novolak (m-cresol / p-cresol ratio 6/4, weight average molecular weight 4000) 0.213 g
-0.032 g of cyanine dye B represented by the following formula
・ 0.008 g of p-toluenesulfonic acid
・ Tetrahydrophthalic anhydride 0.19g
・ Bis-p-hydroxyphenylsulfone 0.126 g
・ 2-methoxy-4- (N-phenylamino) benzenediazonium ・ hexafluorophosphate 0.032 g
-0.078 g of a dye in which the counter anion of Victoria Pure Blue BOH is a 1-naphthalenesulfonic acid anion
・ Fluorine-based surfactant (Megafac F-780, manufactured by Dainippon Ink & Chemicals, Inc.) 0.020 g
・ Γ-butyrolactone 13.18g
・ Methyl ethyl ketone 25.41g
・ 1-methoxy-2-propanol 12.97g

<Coating liquid B2 for image recording layer>
-Phenol / m, p-cresol novolak (phenol / m-cresol / p-cresol = 5/3/2, weight average molecular weight 4000) 0.274 g
-0.029 g of cyanine dye B represented by the above formula
-0.14 g of 30% methyl ethyl ketone solution of structural polymer C represented by the following formula
-Quaternary ammonium salt D shown by the following formula 0.004 g
・ Sulphonium salt E represented by the following formula: 0.065 g
-Fluorosurfactant (Megafac F-780, manufactured by Dainippon Ink & Chemicals, Inc.) 0.004g
・ Fluorosurfactant (Megafac F-782, manufactured by Dainippon Ink & Chemicals, Inc.) 0.020 g
・ Methyl ethyl ketone 10.39g
・ 1-methoxy-2-propanol 20.98g

1-5. Evaluation of the planographic printing plate precursor The printing durability, cleaner resistance (chemical resistance), stain resistance, and stain resistance of the halftone dot non-image area of the obtained planographic printing plate were evaluated by the following methods.

(1) Printing durability The obtained lithographic printing plate precursor was imaged using a Trend setter manufactured by Creo at a drum rotation speed of 150 rpm and a beam intensity of 10 W.
Thereafter, using a PS processor 940H manufactured by Fuji Photo Film Co., Ltd., charged with an alkali developer having the following composition, the solution temperature was maintained at 30 ° C. and development was performed for 20 seconds to obtain a lithographic printing plate. All the lithographic printing plate precursors had good sensitivity.

<Alkali developer composition>
・ D-Sorbit 2.5% by mass
-Sodium hydroxide 0.85 mass%
・ Polyethylene glycol lauryl ether (weight average molecular weight 1,000)
0.5% by mass
・ Water 96.15% by mass

The resulting lithographic printing plate was printed on a Lithrone printing machine manufactured by Komori Corporation using DIC-GEOS (N) black ink manufactured by Dainippon Ink & Chemicals, Inc. The printing durability was evaluated based on the number of printed sheets when visually recognized.
The results are shown in Table 2. The meanings of the symbols in Table 2 are as follows.
A: 30,000 or more A-B: 20,000 or more and less than 30,000 B: 10,000 or more and less than 20,000

(2) Cleaner resistance (chemical resistance)
The evaluation of printing durability in (1) above was performed except that a multi-cleaner manufactured by Fuji Photo Film Co., Ltd. was applied to the surface of the image recording layer for 1 minute and then wiped with water every 5000 sheets during printing. Similarly, cleaner resistance was evaluated based on the number of printed sheets when the ink density (reflection density) was reduced by 0.1 from the start of printing. Here, cleaner resistance was used as a kind of printing durability evaluation method.
The results are shown in Table 2. The meanings of the symbols in Table 2 are as follows.
A: 10,000 or more A-B: 6,000 or more and less than 10,000 B: 3,000 or more and less than 6,000 B-C: 2,000 or more and less than 3,000

(3) Stain resistance Using a planographic printing plate obtained in the same manner as in the above (1) Evaluation of printing durability, Dainippon Ink and Chemicals, Inc. using a Mitsubishi diamond F2 printer (manufactured by Mitsubishi Heavy Industries). Printing was performed using a DIC-GEOS (s) red ink manufactured, and the blanket stain after printing 10,000 sheets was visually evaluated.
The results are shown in Table 2. The meanings of the symbols in Table 2 are as follows.
A: The blanket is hardly dirty. AB: The blanket is slightly dirty.

(4) Stain resistance of halftone dot non-image area The lithographic printing plate obtained above was mounted on a printing machine SOR-M manufactured by Heidelberg, and IF102 3% (manufactured by Fuji Photo Film Co., Ltd.) in fountain solution. The ink is printed using Varius (N) ink (Dainippon Ink Chemical Co., Ltd.), and the amount of dampening water is gradually reduced from the standard water scale, and the shadow area (dot rate 80%) The degree of occurrence of entanglement stains was visually evaluated. The results are shown in Table 2. In the table, the meanings of the symbols are as follows.
A: Halftone dot non-image part is hardly soiled AB: Halftone dot non-image part is slightly dirty

As is apparent from Table 2, the planographic printing plate support obtained by the method for producing a planographic printing plate support of the present invention (Examples 1-1 to 1-44 and 2-41 to 2-43). All of the lithographic printing plates using were excellent in printing durability, stain resistance, cleaner resistance, and stain resistance of halftone dot non-image areas. Among them, the lithographic plates of Examples 1-42 to 1-44 and 2-44 to 2-47 in which the amount of Si adsorbed on the support surface is large and the multilayer type thermal positive type image recording layer 2 is provided. The printing plate was more excellent in the stain resistance of the halftone dot non-image area.
On the other hand, the lithographic printing plate of Comparative Example 1 was poor in printing durability and cleaner resistance.

<Example for the Second Aspect of the Present Invention>
2-1. Production of lithographic printing plate support (Examples 3-1 to 3-45 and Comparative Example 2)
An aluminum plate was prepared in the same manner as in the first embodiment of the present invention, except that the molten metal was prepared using an aluminum alloy having the composition shown in Table 3 (the balance being aluminum and inevitable impurities, the unit being mass%). Got.

  Next, the following process was performed using this aluminum plate.

<Surface treatment>
Next, surface treatment was performed by continuously performing the following treatments (a) to (j) and (l).

(A) Mechanical roughening treatment Rotating while supplying a slurry of slurry and water (specific gravity 1.15) shown in Table 4 as a polishing slurry liquid to the surface of the aluminum plate with a spray tube Mechanical roughening was performed with a roller nylon brush. In addition, the result of having measured the component of the silica sand and the component of a pumice stone used by each Example or the comparative example was as showing below, respectively.

<Pumice stone ingredients>
Silica (silicic acid content: SiO ₂ ) 73% by mass
Alumina (Al ₂ O ₃ ) 14% by mass
Iron oxide (Fe ₂ O ₃ ) 1% by mass
Others <Quad sand component>
Silica (silicic acid content: SiO ₂ ) 95% by mass
Alumina (Al ₂ O ₃ ) 2% by mass
Iron oxide (Fe ₂ O ₃ ) 0.1% by mass
Others remaining

Nylon brush, material 6 · 10 nylon, hair length 50mm (before flocking), No. 3 brush with bristles diameter 0.295mm, holed in a stainless steel tube of φ300mm and planted so as to be dense 3 Used this book.
The distance between the two support rollers (φ200 mm) below the nylon brush was 300 mm, and the rotation direction of the nylon brush was the same as the moving direction of the aluminum plate.
The pushing amount of the nylon brush was adjusted by managing the load of the drive motor that rotates the nylon brush.
The mechanical graining treatment, so that the average surface roughness R _a of the aluminum plate after processing becomes 0.25～0.42Myuemu, flow of the abrasive, the rotational speed of the brush, the moving speed of the aluminum plate or the like Was adjusted appropriately. It shows the average surface roughness R _a of the aluminum plate after mechanical graining treatment in Table 4.

Here, the average surface roughness R _a of the aluminum plate was measured by first the same method as in the case of embodiments of the present invention.

(B) Etching treatment in alkaline aqueous solution (first etching treatment)
The first etching is performed in the same manner as in the first embodiment of the present invention, except that the etching amount of the surface subjected to the first electrochemical roughening treatment after the aluminum plate is set to the values shown in Table 4. Processed.
Thereafter, the liquid was drained with a nip roller by the same method as in the first aspect of the present invention, and after a water washing treatment described later, the liquid was drained with a nip roller.

(C) Desmut treatment in acidic aqueous solution (first desmut treatment)
The first desmut treatment was performed by the same method as in the first aspect of the present invention.
Thereafter, the liquid was drained with a nip roller.

(D) First electrochemical surface roughening treatment Next, a first electrochemical surface roughening treatment was performed using an electrolytic solution having a nitric acid concentration, an aluminum ion concentration, and a liquid temperature shown in Table 4. The electrolytic solution was prepared using 68 mass% nitric acid aqueous solution and aluminum nitrate nonahydrate in the amounts shown in Table 4. The ratio R between the aluminum ion concentration A and the nitric acid concentration N of each electrolytic solution was as shown in Table 4. The ammonium ion concentration was 70 mg / L.
An electrochemical surface roughening process was performed using a power source that generates an alternating current having an arbitrary waveform, which is current-controlled by PWM control using an IGBT element.
A carbon electrode was used as the counter electrode, and an iridium oxide electrode was used as the auxiliary anode. As the electrolytic cell, two radial type cells as shown in FIG. 4 were used.
Table 4 shows the time TP until the waveform, frequency, and current value of the generated alternating current reached a peak from zero, and the duty was 0.5. Table 4 shows the current density during the anode reaction of the aluminum plate at the peak of the alternating current, the amount of electricity (the total amount of electricity during the anode reaction of the aluminum plate), and the current ratio r in the main electrolytic cell. It was. The current ratio r was adjusted by the amount of current diverted to the auxiliary anode.
The aluminum plate was supplied into the main electrolytic cell so that the relative speed with respect to the electrolytic solution in the main electrolytic cell was 1 to 2 m / sec, and the average was 1.5 m / sec.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

(E) Etching treatment in alkaline aqueous solution (second etching treatment)
The second etching is performed in the same manner as in the first embodiment of the present invention except that the etching amount of the surface subjected to the second electrochemical roughening treatment after the aluminum plate is set to the value shown in Table 4. Processed.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.
After the second etching treatment, the measured average surface roughness R _a of the surface of the aluminum plate became as shown in Table 4. The average surface roughness _Ra was measured by the same method as described in (a) above.

(F) Desmut treatment in acidic aqueous solution (second desmut treatment)
The second desmut treatment was performed by the same method as in the first embodiment of the present invention.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

(G) Second electrochemical roughening treatment An electrolytic solution having a hydrochloric acid concentration and an aluminum ion concentration shown in Table 4 and a liquid temperature of 35 ° C. was used. The electrolytic solution was prepared using 35% by mass hydrochloric acid aqueous solution and aluminum chloride hexahydrate shown in Table 4. The aluminum ion concentration was adjusted using aluminum chloride.
An electrochemical surface roughening process was performed using a power source that generates an alternating current having an arbitrary waveform, which is current-controlled using PWM control using an IGBT element.
A carbon electrode was used as the counter electrode, and an iridium oxide electrode was used as the auxiliary anode. As the electrolytic cell, one radial type cell as shown in FIG. 4 was used.
The waveform of the generated alternating current was a trapezoidal wave, the frequency was 60 Hz, the time TP until the current value reached the peak from zero was 0.8 msec, and the duty was 0.5. Table 4 shows the current density, the amount of electricity, and the current ratio during the anode reaction of the aluminum plate at the peak of alternating current. The current ratio was adjusted by the amount of current diverted to the auxiliary anode. The aluminum plate was supplied into the main electrolytic cell so that the relative speed with respect to the electrolytic solution in the main electrolytic cell was 1 to 2 m / sec, and the average was 1.5 m / sec.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

(H) Etching treatment in alkaline aqueous solution (third etching treatment)
A third etching process was performed in the same manner as in the first aspect of the present invention. Table 4 shows the etching amount of the surface of the aluminum plate that has been subjected to the second electrochemical roughening treatment.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

(I) Desmutting treatment in acidic aqueous solution (third desmutting treatment)
A third desmut treatment was performed in the same manner as in the first aspect of the present invention.
Thereafter, the liquid was drained with a nip roller.

(J) Anodizing treatment Anodizing treatment was carried out by the same method as in the first embodiment of the present invention.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

(L) Hydrophilization treatment 2
Hydrophilic treatment 2 was performed by the same method as in the first embodiment of the present invention.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller. Then, 90 degreeC wind was blown for 10 seconds and it dried, and the support body for lithographic printing plates was obtained.

(Examples 3-46 to 3-48)
A lithographic printing plate support was obtained in the same manner as in Examples 3-1 to 3-45 except that the process (k) described below was performed instead of the process (l).

(K) Hydrophilization treatment 1
Hydrophilization treatment 1 was performed by the same method as in the first embodiment of the present invention.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller. Then, 90 degreeC wind was blown for 10 seconds and it dried, and the support body for lithographic printing plates was obtained.

2-2. Observation of the surface of the lithographic printing plate support The surface of each lithographic printing plate support obtained in Examples 3-1 to 3-48 was scanned using a scanning electron microscope (JSM-5500, manufactured by JEOL Ltd., below). The same was observed at a magnification of 50000, and fine irregularities having an average opening diameter of 0.05 to 0.3 μm were formed uniformly and densely.
Further, when observed at a magnification of 2000 using a scanning electron microscope, irregularities (honeycomb pits) having an average opening diameter of 1 to 6 μm were formed on the surface of the lithographic printing plate support of Examples 3-1 to 3-48. It was generated uniformly.
Further, when each lithographic printing plate support was observed with an inclination angle of 30 °, a large concavo-convex structure (swell) having a pitch of 5 to 20 μm was formed.
On the other hand, when the surface shape of the lithographic printing plate support obtained in Comparative Example 2 was observed in the same manner, irregularities were generated on the surface, but the irregularities were compared with those in the example. It was uneven.

2-3. Appearance Evaluation Next, streaks generated on the surface of each lithographic printing plate support obtained in Examples 3-1 to 3-48 were visually observed. The results are shown in Table 4. The meanings of the symbols in Table 4 are as follows.
A: Streaks are hardly visible A-B: Streaks are slightly visible B: Streaks are visible but lower limit of allowable range As apparent from Table 4, Examples 3-12 to 3-17 using silica sand as an abrasive The support for lithographic printing plates 3-47 and 3-48 had almost no streaks and an excellent appearance.

2-4. Preparation of lithographic printing plate precursor A lithographic printing plate precursor was obtained by providing each lithographic printing plate support obtained above with a thermal positive type image recording layer as follows.

  On each lithographic printing plate support obtained in Examples 3-1 to 3-45 and Comparative Example 2, Examples 1-42 to 1-44 and 2-44 to 2 of the first aspect of the present invention were used. The undercoat layer and the image recording layer 2 were formed in the same manner as in the case of each lithographic printing plate support obtained in -47, to obtain a lithographic printing plate precursor.

  On each lithographic printing plate support obtained in Examples 3-46 to 3-48, Examples 1-1 to 1-41 and 2-1 to 2-43 of the first aspect of the present invention and comparison The undercoat layer and the image recording layer 1 were formed in the same manner as in the case of each lithographic printing plate support obtained in Example 1 to obtain a lithographic printing plate precursor.

2-5. Evaluation of lithographic printing plate precursor The printing durability, cleaner resistance (chemical resistance), stain resistance, stain resistance of non-image areas and shinyness of the obtained lithographic printing plate precursor were evaluated by the following methods. .

(1) Printing durability Printing durability was evaluated by the same method as in the first embodiment of the present invention.
The results are shown in Table 4. The meaning of the symbols in Table 4 is the same as in the case of the first aspect of the present invention.

(2) Cleaner resistance (chemical resistance)
Cleaner resistance (chemical resistance) was evaluated by the same method as in the first embodiment of the present invention.
The results are shown in Table 4. The meaning of the symbols in Table 4 is the same as in the case of the first aspect of the present invention.

(3) Stain resistance The soil resistance was evaluated by the same method as in the first embodiment of the present invention.
The results are shown in Table 4. The meaning of the symbols in Table 4 is the same as in the case of the first aspect of the present invention.

(4) Stain resistance of halftone dot non-image area The stain resistance of the halftone dot non-image area was evaluated by the same method as in the first embodiment of the present invention.
The results are shown in Table 4. The meaning of the symbols in Table 4 is the same as in the case of the first aspect of the present invention.

(5) Shiny (1) A lithographic printing plate obtained by the same method as in the evaluation of printing durability is attached to a Lislon printing machine manufactured by Komori Corporation, and the surface of the printing plate is removed while increasing the amount of dampening water supplied. The brightness of the image area was visually observed, and the shiny (ease of seeing water) was evaluated based on the amount of dampening water supplied when it started to shine.
The results are shown in Table 4. The meanings of the symbols in Table 4 are as follows.
A: The amount of dampening water when starting to shine is very large. B: The amount of dampening water when starting to shine is large.

As is apparent from Table 4, the lithographic printing plate using the lithographic printing plate support obtained by the method for producing a lithographic printing plate support of the present invention (Examples 3-1 to 3-48), All of them were excellent in printing durability, stain resistance, cleaner resistance, stain resistance of halftone dot non-image areas, and shiny.
Further, Examples 3-1 to 3-45 in which the image recording layer 1 was formed after the hydrophilization treatment 2 were more excellent in stain resistance of the halftone dot non-image portion.
On the other hand, Comparative Example 2, R _a after the second etching process is not a sufficient value, as compared with Example 3-1～3-48, printing durability, cleaner resistance was inferior.

It is a side view which shows the concept of the process of the brush graining in the manufacturing method of the support body for lithographic printing plates of this invention. It is typical sectional drawing of the apparatus which performs a water washing process with the free-fall curtain-like liquid film used for the water washing process in the manufacturing method of the support body for lithographic printing plates of this invention. It is a graph which shows an example of the current waveform used for the electrochemical roughening process in the manufacturing method of the support body for lithographic printing plates of this invention. It is a side view which shows an example of the radial type cell in the electrochemical roughening process using alternating current in the manufacturing method of the support body for lithographic printing plates of this invention. It is the schematic of the anodizing apparatus used for the anodizing process in the manufacturing method of the support body for lithographic printing plates of this invention. It is the schematic of the other anodizing apparatus used for the anodizing process in the manufacturing method of the support body for lithographic printing plates of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aluminum plate 2, 4 Roller-like brush 3 Polishing slurry liquid 5, 6, 7, 8 Support roller 11 Aluminum plate 12 Radial drum roller 13a, 13b Main electrode 14 Electrolytic process liquid 15 Electrolyte supply port 16 Slit 17 Electrolyte path 18 Auxiliary anode 19a, 19b Thyristor 20 AC power supply 40 Main electrolytic cell 50 Auxiliary anode tank 100 Apparatus for washing with water by free-fall curtain liquid film 102 Water 104 Reservoir tank 106 Water supply cylinder 108 Rectifier 410 Anodizing apparatus 412 Power supply tank 413 Intermediate tank 414 Anodizing tank 416 Aluminum plate 418, 426 Electrolyte 420 Anode 422, 428 Pass roller 424 Nip roller 430 Cathode 434 DC power supply 436, 438 Liquid supply nozzle 440 Shielding plate 442 Drain outlet

Claims (8)

A mechanical surface roughening treatment for roughening the aluminum plate to have an average surface roughness _Ra of 0.25 to 0.40 μm using at least a brush and a slurry liquid containing an abrasive; An electrochemical roughening treatment for roughening using an alternating current in an aqueous solution containing nitric acid and an alkali etching treatment for etching in an alkaline aqueous solution are performed in this order, and the average after the alkali etching treatment A method for producing a lithographic printing plate support, which obtains a lithographic printing plate support having _a surface roughness _Ra of 0.41 to 0.6 µm. Between the mechanical roughening treatment and the electrochemical roughening treatment, the aluminum plate is subjected to an alkali etching treatment for etching in an alkaline aqueous solution,
After the alkali etching treatment performed after the electrochemical roughening treatment, an electrochemical roughening treatment in which the aluminum plate is roughened using an alternating current in an aqueous solution containing hydrochloric acid, The method for producing a lithographic printing plate support according to claim 1, wherein the anodizing treatment is performed in this order to obtain a lithographic printing plate support.   The alternating current used in the aqueous solution containing nitric acid is such that the ratio r between the quantity of electricity QRF when the aluminum plate is a cathode and the quantity of electricity QF when an anode is 0.4 ≦ r ≦ 0.8. Item 3. A method for producing a lithographic printing plate support according to Item 1 or 2.   The method for producing a lithographic printing plate support according to any one of claims 1 to 3, wherein the waveform of the alternating current used in the aqueous solution containing nitric acid is a trapezoidal wave.   The method for producing a lithographic printing plate support according to any one of claims 1 to 4, wherein the concentration of the nitric acid in the aqueous solution containing nitric acid is 15 to 50 g / L. A mechanical surface roughening treatment for roughening the aluminum plate to have an average surface roughness _Ra of 0.25 to 0.42 μm using at least a brush and a slurry liquid containing an abrasive; An electrochemical surface roughening treatment for roughening using an alternating current in an aqueous solution containing nitric acid and aluminum ions and an alkali etching treatment for etching in an alkaline aqueous solution are performed in this order, and the alkali a method of manufacturing a lithographic printing plate support mean surface roughness R _a after the etching process to obtain a lithographic printing plate support is 0.43～0.60Myuemu,
The aqueous solution has a concentration ratio R between the aluminum ion concentration A and the nitric acid concentration N of 0.6 or more, and the alternating current has a ratio r of the amount of electricity QR when the aluminum plate is cathode and the amount of electricity QF when the anode is anode. A method for producing a lithographic printing plate support, wherein 0.8 ≦ r ≦ 1.0.   The method for producing a lithographic printing plate support according to claim 6, wherein the aqueous solution containing nitric acid and aluminum ions contains 1 to 15 g / L of nitric acid and 1 to 15 g / L of aluminum ions. Between the mechanical roughening treatment and the electrochemical roughening treatment, the aluminum plate is subjected to an alkali etching treatment for etching in an alkaline aqueous solution,
After the alkali etching treatment performed after the electrochemical roughening treatment, an electrochemical roughening treatment in which the aluminum plate is roughened using an alternating current in an aqueous solution containing hydrochloric acid, The method for producing a lithographic printing plate support according to claim 6 or 7, wherein the anodizing treatment is performed in this order to obtain a lithographic printing plate support.

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