JP2006076281A - Method for manufacturing support for lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method, for manufacturing a support for a lithographic printing plate, which produces an original lithographic printing plate with excellent stain resistance and resistance to plate wear by electrochemically roughening the surface of the original plate once. <P>SOLUTION: In this method, an aluminum plate is subjected to a process to electrochemically roughen the surface of the plate by running alternating current in an aqueous solution with not more than pH 0.8 value containing at least a chloride ion and a nitric acid ion so that the sum of an electrical quantity is 100 to 300 C/dm<SP>2</SP>when the aluminum plate is used as an anode, and thus, the support for the lithographic printing plate is manufactured. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a lithographic printing plate support. More specifically, the present invention relates to a method for producing a lithographic printing plate support used for a lithographic printing plate precursor that is excellent in both stain resistance and printing durability.

  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.

  The surface of an aluminum support for a lithographic printing plate used for a lithographic printing plate (hereinafter also referred to simply as “support for a lithographic printing plate”) has hydrophilicity and water retention because it is used to carry a non-image area. Various performances that are contradictory are required, such as excellent adhesion and excellent adhesion to the image recording layer formed thereon. If the hydrophilicity of the surface of the lithographic printing plate support is too low, ink will adhere to the non-image area during printing, and the blanket cylinder will be soiled, and so-called background soiling 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 amount of water shown during printing is increased. 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.

  Accordingly, in order to improve various performances such as stain resistance and printing durability, the surface of the lithographic printing plate support is subjected to a surface roughening treatment or other surface treatment. Examples of the roughening treatment include mechanical roughening such as ball graining, brush graining, wire graining, and blast graining, and an aluminum plate is immersed in an acidic solution and AC current is applied to the aluminum plate. There are known electrochemical surface roughening treatment, chemical etching (chemical surface roughening treatment), and a combination thereof.

  Among these surface roughening treatment methods, when electrochemical surface roughening is performed, if an aqueous solution containing nitric acid is used as the acidic solution, recesses (pits) having an average diameter of about 1 to 5 μm are formed on the entire surface of the aluminum plate. Are uniformly formed. If an aqueous solution containing hydrochloric acid is used as the acidic solution, pits having an average diameter of about 0.01 to 0.5 μm are uniformly formed on the entire surface of the aluminum plate.

  In addition, after performing an electrochemical surface roughening treatment using an aqueous solution containing nitric acid as an acidic solution, and then performing an electrochemical surface roughening using an aqueous solution containing hydrochloric acid as the acidic solution, the surface of the aluminum plate In this case, irregularities in which pits having an average diameter of about 1 to 5 μm and pits having an average diameter of about 0.01 to 0.5 μm are superimposed are formed over the entire surface. A lithographic printing plate using such a surface-shaped aluminum plate as a support for a lithographic printing plate has good stain resistance and printing durability.

Patent Document 1 discloses a step of subjecting an aluminum plate or an aluminum alloy plate to a rough surface by AC electrolysis at a current density exceeding 10 A / dm ² in a solution obtained by adding nitric acid to 1 to 3% hydrochloric acid, It describes a method for producing an offset printing base plate that includes a step of performing mild etching in an alkaline aqueous solution and a step of forming an anodized film having a thickness of 5 μm or less by anodizing.

Japanese Patent Publication No. 48-28123

However, when electrochemical surface roughening is performed using an aqueous solution containing nitric acid as an acidic solution and then an electrochemical surface roughening using an aqueous solution containing hydrochloric acid as an acidic solution, It is necessary to perform the rough surface treatment twice. Therefore, there are many steps required to produce a lithographic printing plate support, which increases complicated operations.
In addition, as a result of the study by the present inventors, in the technique described in Patent Document 1, pits having an average diameter of about 1 to 5 μm and coarse concave portions exceeding an average diameter of 10 μm are mixedly formed on the surface of the aluminum plate. It has been found that a lithographic printing plate using such a surface-shaped aluminum plate as a support for a lithographic printing plate has insufficient stain resistance and printing durability.

  Accordingly, the present invention provides a method for producing a lithographic printing plate support capable of obtaining a lithographic printing plate precursor excellent in both stain resistance and printing durability by a single electrochemical surface roughening treatment. The purpose is to do.

As a result of earnest research to achieve the above object, the present inventor has found that the total amount of electricity when the aluminum plate is an anode is 100 to 300 C in an aqueous solution containing at least chloride ions and nitrate ions in the aluminum plate. Lithographic printing using the obtained lithographic printing plate support, even though the number of times of applying an electrochemical surface roughening treatment to the aluminum plate is one when an alternating current is applied so as to be / dm ² It has been found that the plate precursor is excellent in both stain resistance and printing durability.

That is, the present invention provides the following (1) to (6).
(1) An electric current is passed through an aluminum plate in an aqueous solution containing at least chloride ions and nitrate ions so that the total amount of electricity when the aluminum plate is an anode is 100 to 300 C / dm ^2. A method for producing a support for a lithographic printing plate, wherein a chemical roughening treatment is performed to obtain a support for a lithographic printing plate.
(2) The method for producing a lithographic printing plate support according to (1), wherein the aqueous solution contains hydrochloric acid and nitric acid.
(3) The lithographic printing plate support according to (1) or (2), wherein the aqueous solution has a chloride ion concentration of 3 g / L or more and a nitrate ion concentration of 0.50 g / L or more. Body manufacturing method.
(4) The method for producing a lithographic printing plate support according to any one of (1) to (3), wherein the aqueous solution has a pH of 0.8 or less.
(5) The method for producing a lithographic printing plate support according to any one of (1) to (4), wherein the aqueous solution contains 2 g / L or more of aluminum ions.
(6) The method for producing a lithographic printing plate support according to any one of (1) to (5), wherein the aluminum plate has a concavo-convex pattern on a surface thereof.

  As will be described below, according to the present invention, a lithographic printing plate support used for a lithographic printing plate precursor which is excellent in both stain resistance and printing durability when used as a lithographic printing plate can be obtained. In addition, a lithographic printing plate support used for a lithographic printing plate precursor that is excellent in both stain resistance and printing durability when made into a lithographic printing plate is subjected to an electrochemical roughening treatment once on an aluminum plate. It is obtained by applying.

Hereinafter, the present invention will be described in detail.
[Method for producing support for lithographic printing plate]
<Aluminum plate (rolled aluminum)>
A known aluminum plate can be used in the method for producing a lithographic printing plate support of the present invention. The aluminum plate used in the present invention is a metal mainly composed of 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 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. The foreign elements that may be contained in the aluminum alloy include silicon, iron, copper, manganese, magnesium, chromium, zinc, bismuth, nickel, titanium, etc., and the content of the foreign elements in the alloy is 10% by mass or less. It is.

Thus, 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 the Light Metal Association), for example, JIS Al-Mn aluminum plates such as A1050, JIS A1100, JIS A1070, JIS A3004 containing Mn, and internationally registered alloy 3103A can be appropriately used. For the purpose of increasing the tensile strength, an Al—Mg alloy or an Al—Mn—Mg alloy (JIS A3005) in which 0.1% by 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 UBC (Used Beverage Can) ingot which melt | dissolved the used aluminum beverage can can also be used.
In this aluminum plate, the Cu content is preferably 0.00% by mass or more, more preferably 0.01% by mass or more, more preferably 0.02% by mass or more, The content is preferably 0.15% by mass or less, more preferably 0.11% by mass or less, and further preferably 0.03% by mass or less. Particularly preferred are Si: 0.07 to 0.09 mass%, Fe: 0.20 to 0.29 mass%, Cu: 0.03 mass% or less, Mn: 0.01 mass% or less, Mg: 0 0.01% by mass or less, Cr: 0.01% by mass or less, Zn: 0.01% by mass or less, Ti: 0.02% by mass or less, and Al: 99.5% 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 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 manufactured. 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, even 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.

  In the present invention, an aluminum plate as shown above can be used by forming irregularities by press rolling, transfer or the like in the final rolling step or the like.

Above all, along with cold rolling to adjust the final plate thickness or finish cold rolling to finish the surface shape after final plate thickness adjustment, the uneven surface is transferred to the aluminum plate surface by pressing the uneven surface to the aluminum plate. A method of forming an uneven pattern is preferred. Specifically, the method described in JP-A-6-262203 can be suitably used.
By using an aluminum plate having a concavo-convex pattern on the surface, it is possible to obtain a concavo-convex pattern having a uniform average pitch and depth than the concavo-convex pattern formed by the brush and the abrasive, thereby improving the stain resistance. In addition, the amount of dampening water on the printing press can be easily adjusted while reducing energy consumed in the subsequent alkali etching treatment and surface roughening treatment. For example, in the first etching process described later, the etching amount can be reduced to about 3 g / m ² or less. In addition, when an aluminum plate having a concavo-convex pattern is used, the surface area of the obtained lithographic printing plate support is increased, so that the printing durability is more excellent.

The transfer is particularly preferably performed in the final cold rolling step of a normal aluminum plate. Rolling for transfer is preferably performed in 1 to 3 passes, and each rolling reduction is preferably 3 to 8%.
Moreover, it is more preferable that the unevenness | corrugation provided by transcription | transfer is provided on both surfaces of an aluminum plate. Thereby, since the elongation rate of the aluminum plate of a surface and a back surface can be adjusted to the same grade, an aluminum plate with sufficient flatness can be obtained.

Examples of a method for obtaining a rolling roll having unevenness on the surface (hereinafter also referred to as a transfer roll) used for unevenness transfer include a blast method, an electrolytic method, a laser method, an electric discharge machining method, and a method combining these. Can be mentioned. Among these, a method in which the blast method and the electrolytic method are combined is preferable. Among the blast methods, the air blast method is preferable.
The air pressure in the air blast method is preferably 1 to 10 kgf / cm ² (9.81 × 10 ^{4 to} 9.81 × 10 ⁵ Pa), and ² to ⁵ kgf / cm ² (1.96 × 10 ⁵ to More preferably 4.90 × 10 ⁵ Pa).
The grid used in the air blast method is not particularly limited as long as it is alumina particles having a predetermined particle size. If alumina particles having hard and sharp corners are used for the grid, it is easy to form deep and uniform irregularities on the surface of the transfer roll.
The average particle diameter of the alumina particles is 50 to 150 μm, preferably 60 to 130 μm, and more preferably 70 to 90 μm. If it is within the above range, a surface roughness having a sufficient size as a transfer roll can be obtained, so that the surface roughness of an aluminum plate provided with irregularities using this transfer roll is sufficiently increased. Also, the number of pits can be increased sufficiently.

In the air blast method, the injection is preferably performed 2 to 5 times, and more preferably 2 times. When the injection is performed twice, the uneven portions of unevenness formed by the first injection can be scraped off by the second injection, so that the surface of the aluminum plate provided with the unevenness using the obtained rolling roll, Locally deep recesses are less likely to be formed. As a result, the developability (sensitivity) of the lithographic printing plate is excellent.
The injection angle in the air blast method is preferably 60 to 120 °, more preferably 80 to 100 ° with respect to the injection surface (roll surface).

After performing the air blasting method, it is preferable to perform polishing until the average surface roughness ( _Ra ) is reduced by 10 to 40% from the value after air blasting before performing the plating treatment described later. For polishing, it is preferable to use sandpaper, a grindstone, or a buff. By polishing, the height of the projections on the surface of the transfer roll can be made uniform, and as a result, locally deep portions are not formed on the surface of the aluminum plate provided with irregularities using this transfer roll. As a result, the developability (sensitivity) of the planographic printing plate is particularly excellent.

The average surface roughness ( _Ra ) of the surface of the transfer roll is preferably 0.4 to 1.0 [mu] m, and more preferably 0.6 to 0.9 [mu] m.
Number of peaks of the surface of the transfer roll is preferably from 1000 to 40000 pieces / mm ^2, and more preferably 2,000 to 10,000 pieces / mm ^2. If the number of peaks is too small, the water retention of the lithographic printing plate support and the adhesion to the image recording layer are poor. If the water retention is inferior, the halftone dot portion tends to become dirty when a planographic printing plate is used.

The material of the transfer roll is not particularly limited, and for example, a known material for a rolling roll can be used.
In the present invention, it is preferable to use a steel roll. Among these, a roll made by casting is preferable. An example of a composition of a preferable roll material is C: 0.07 to 6% by mass, Si: 0.2 to 1% by mass, Mn: 0.15 to 1% by mass, P: 0.03% by mass or less, S: 0.03% by mass or less, Cr: 2.5 to 12% by mass, Mo: 0.05 to 1.1% by mass, Cu: 0.5% by mass or less, V: 0.5% by mass or less, balance: iron And inevitable impurities.
Further, tool steel (SKD), high-speed steel (SKH), high carbon chromium bearing steel (SUJ), and forged steel containing carbon, chromium, molybdenum, and vanadium as alloy elements, which are generally used as rolling rolls, can be mentioned. It is done. In order to obtain a long roll life, a high chromium alloy cast iron containing about 10 to 20% by mass of chromium can also be used.
Among these, it is preferable to use a roll manufactured by a casting method. In this case, the hardness after quenching and tempering is preferably 80 to 100 in terms of Hs. The tempering is preferably performed at a low temperature.
The diameter of the roll is preferably 200 to 1000 mm. Moreover, it is preferable that the surface length of a roll is 1000-4000 mm.

The transfer roll formed with irregularities by the air blast method or the like is preferably subjected to hardening treatment such as quenching and hard chrome plating after washing. This improves wear resistance and prolongs life.
As the hardening treatment, hard chrome plating is particularly preferable. Hard chromium plating can be performed by electroplating using a conventionally known CrO ₃ —SO ₄ bath, CrO ₃ —SO ₄ —fluoride bath, or the like as an industrial chromium plating method.
The thickness of the hard chrome plating film is preferably 5 to 15 μm. Within the above range, the effect of improving the wear resistance is sufficient. The thickness of the hard chrome plating film can be adjusted by adjusting the plating treatment time.
Prior to the hard chrome plating, it is preferable to perform electrolytic treatment at a quantity of electricity of 5,000 to 50,000 C / dm ² using a direct current using a roll as an anode in a plating solution used for hard chrome plating. . Thereby, the unevenness | corrugation of the surface of a roll can be equalize | homogenized.

For an aluminum plate, the average surface roughness _Ra is measured by measuring the two-dimensional roughness with a stylus type roughness meter (for example, sufcom 575, manufactured by Tokyo Seimitsu Co., Ltd.) and measuring the average roughness specified in ISO4287. _Ra is measured 5 times, and the average value is defined as the average roughness.
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
R _max and R _sm can be measured in accordance with ISO 4287.

The aluminum plate used in the present invention is a continuous belt-like sheet material or plate material. That is, it may be an aluminum web, or a sheet-like sheet cut to a size corresponding to a planographic printing plate precursor shipped as a product.
Since scratches on the surface of the aluminum plate may become defects when processed into a lithographic printing plate support, it is possible to generate scratches at the stage prior to the surface treatment process for making a lithographic printing plate support It is necessary to suppress as much as possible. For that purpose, it is preferable that the package has a stable form and is hardly damaged during transportation.
In the case of an aluminum web, for example, the packaging of aluminum is, for example, laying a hardboard and felt on an iron pallet, applying cardboard donut plates to both ends of the product, wrapping the whole with a polytube, and inserting a wooden donut into the inner diameter of the coil Then, a felt is applied to the outer periphery of the coil, the band iron is used to squeeze it, and the display is performed on the outer periphery. Moreover, a polyethylene film can be used as the packaging material, and needle felt and hard board can be used as the cushioning material. There are various other forms, but the present invention is not limited to this method as long as it is stable and can be transported without being damaged.

  The thickness of the aluminum plate used in the present invention is about 0.1 to 0.6 mm, preferably 0.15 to 0.4 mm, and more preferably 0.2 to 0.3 mm. This thickness can be appropriately changed according to the size of the printing press, the size of the printing plate, the user's desires, and the like.

<Surface treatment>
The present invention relates to an aluminum plate as described above, in an aqueous solution containing at least chloride ion and nitrate ion, wherein the aluminum plate is an alternating current so the total amount of electricity during the anode is 100~300C / dm ² The lithographic printing plate support is obtained by applying an electrochemical surface roughening treatment.

In the surface treatment, various steps other than the electrochemical surface roughening treatment may be included.
Specifically, for example, an etching treatment in an alkaline aqueous solution (hereinafter also referred to as “first etching treatment”), a desmutting treatment in an acidic aqueous solution (hereinafter also referred to as “first desmutting treatment”), and electrochemical. Roughening treatment, etching treatment in an alkaline aqueous solution (hereinafter also referred to as “second etching treatment”), desmutting treatment in an acidic aqueous solution (hereinafter also referred to as “second desmutting treatment”), and anodizing treatment are performed. The method of applying in order is mentioned suitably.
Further, after the anodizing treatment, a sealing treatment, a hydrophilization treatment, or a sealing treatment and a subsequent hydrophilization treatment are also preferable.

Further, a mechanical surface roughening process can be performed before the first etching process. Examples of the mechanical surface roughening treatment include, for example, a wire brush grain method in which the aluminum surface is scratched with a metal wire, a ball grain method in which the aluminum surface is grained with a polishing ball and an abrasive, JP-A-6-135175, and Japanese Patent Publication No. 50. The brush grain method in which the surface is grained with a nylon brush and an abrasive described in Japanese Patent No. -40047 can be used.
Further, as described above, a transfer method (transfer roll method) in which the uneven surface of the transfer roll is pressed against the aluminum plate can also be used. That is, in addition to the methods described in JP-A-55-74898, JP-A-60-36195, and JP-A-60-20396, transfer is performed several times. The method described in JP-A-6-24168 and JP-A-6-24168 characterized in that the surface is elastic is also applicable.
Among these, the transfer roll method is preferable because it can easily cope with the speedup of the manufacturing process of the support for a lithographic printing plate. As described above, the transfer roll method preferably performs transfer in cold rolling for adjusting to the final plate thickness or finishing cold rolling for finishing the surface shape after final plate thickness adjustment.

  The amount of electricity used for the electrochemical roughening treatment can be reduced by performing a mechanical roughening treatment before the first etching treatment, or by providing irregularities with a transfer roll. In addition, a lithographic printing plate produced by using the obtained lithographic printing plate support by performing a mechanical surface roughening treatment before the first etching treatment or imparting unevenness by a transfer roll. Shiny (easy to see after water) is improved.

  Hereinafter, each step of the surface treatment will be described in detail.

<First etching process>
An alkali etching process is a process which melt | dissolves a surface layer by making the aluminum plate mentioned above contact an alkaline solution.

The first etching process performed before the electrochemical surface roughening process is performed by forming a uniform recess by the electrochemical surface roughening process, and rolling oil, dirt on the surface of the aluminum plate (rolled aluminum), It is performed for the purpose of removing a natural oxide film or the like.
In the first etching treatment, the etching amount of the surface to be subjected to electrochemical roughening treatment later is preferably 0.5 g / m ² or more, more preferably 1 g / m ² or more. but preferably not more 10 g / m ² or less, more preferably 5 g / m ² or less. When the etching amount is 0.5 g / m ² or more, uniform pits can be generated in the electrochemical roughening treatment. When the etching amount is 10 g / m ² or less, the amount of the alkaline aqueous solution used is reduced, which is economically advantageous.

The etching amount of the back surface of the surface subjected to the electrochemical roughening treatment is preferably 5% or more of the etching amount of the surface subjected to the electrochemical roughening treatment, preferably 10% or more. Is more preferably 50% or less, and more preferably 30% or less. It is excellent in the balance with the removal effect of the rolling oil of the back surface of an aluminum plate, and economical efficiency as it is the said range.
The same applies to the second etching process described later.

  Examples of the alkali used in the alkaline solution include caustic alkali and alkali metal salt. Specifically, examples of the 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 1% by mass or more, more preferably 20% by mass or more, and preferably 40% by mass or less, and 35% by mass or less. It is more preferable that
The alkaline solution preferably contains aluminum ions. The aluminum ion concentration is preferably 0.5% by mass or more, more preferably 4% by mass or more, and preferably 10% by mass or less, more preferably 8% by mass or less. . Such an alkaline solution can be prepared using, for example, water, a 48% by mass aqueous caustic soda solution, and sodium aluminate.

In the first etching treatment, the temperature of the alkaline solution is preferably 25 ° C. or higher, more preferably 40 ° C. or higher, preferably 95 ° C. or lower, and 80 ° 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, and preferably 30 seconds or shorter, more preferably 10 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 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. And the temperature, or the liquid composition is measured by the electric 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, an industrial grade of 40 to 60% by 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 hydrometer, it is preferable to use a differential pressure type.

  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. 1 is a schematic cross-sectional view of an apparatus for washing with a free-fall curtain-like liquid film. As shown in FIG. 1, an apparatus 100 for performing water washing treatment with 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-falling curtain-like liquid film from 104 to the aluminum plate 1.
In the apparatus 100, water 102 is supplied to the water supply tank 104 from the water supply pipe 106, and when the water 102 overflows from the water supply tank 104, the water is rectified by the 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. 1 is used, the aluminum plate can be uniformly washed with water, so that the uniformity of the treatment performed before the washing process is improved. Can be improved.
As a specific apparatus for washing with a free-fall curtain-like liquid film, for example, an apparatus described in JP-A-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 aqueous solution.

  Examples of the acid used include nitric acid, sulfuric acid, hydrochloric acid, and chromic acid. Of these, nitric acid and sulfuric acid are preferable. Specifically, for example, a waste solution of an aqueous sulfuric acid solution used in an anodic oxidation process described later can be suitably used.

  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 0.5 to 30% by mass of acid and 0.5 to 10% by mass of aluminum ions.

  The temperature of the acidic solution is preferably 25 ° C. or higher, and preferably 95 ° C. or lower.

  In the first desmutting 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. .

Examples of the method of bringing the aluminum plate into contact with the acidic solution include a method in which the aluminum plate is passed through a tank containing the acidic solution, a method in which the aluminum plate is immersed in a tank containing the acidic solution, and the acidic solution being 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 an etching solution in an amount of 10 to 100 L / min per spray tube from a spray tube having holes of φ2 to 5 mm 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, 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.

<Electrochemical roughening treatment>
In the electrochemical surface roughening treatment, in an aqueous solution containing chloride ions and nitrate ions, an alternating current is applied to the aluminum plate so that the total amount of electricity when the aluminum plate is an anode is 100 to 300 C / dm ^2. Shed.

  As shown in FIG. 2, aluminum having a surface shape in which concave portions (pits) having an average diameter of 1 to 5 μm and pits having an average diameter of 0.01 to 0.5 μm are superimposed by the electrochemical roughening treatment of the present invention. The plate can be obtained by a single electrochemical roughening treatment. Thus, in the present invention, the pits are uniformly formed on the surface after the electrochemical roughening treatment, so that the printing durability when the planographic printing plate is obtained is excellent, and the pits are Since it is uniform, the stain resistance when a lithographic printing plate is obtained is excellent.

In the electrochemical roughening treatment of the present invention, the total amount of electricity when the aluminum plate is an anode is 100 to 300 C / dm ² , and preferably 150 to 250 C / dm ² . When the total amount of electricity when the aluminum plate is an anode is within the above range, the aluminum plate is sufficiently subjected to electrochemical surface roughening treatment. Irregularities in which pits having a diameter of 0.01 to 0.5 μm are uniformly superimposed are formed. In addition, the depth of the pits having an average diameter of 0.01 to 0.5 μm is measured in an aqueous solution containing hydrochloric acid after an aluminum plate is subjected to electrochemical roughening by flowing an alternating current in an aqueous solution containing nitric acid. Compared to the case where electrochemical roughening is applied by passing an alternating current, it becomes slightly shallower.
On the other hand, even when an aqueous solution containing chloride ions and nitrate ions is used, if the amount of electricity is large as in the method described in Patent Document 1, coarse pits are formed at various locations on the surface of the aluminum plate. The pits formed on the surface of the aluminum plate are not uniform.

The chloride ion concentration of the aqueous solution used as the electrolytic solution is preferably 3 to 60 g / L, and more preferably 8 to 50 g / L. Within the above range, the uniformity of the pits becomes high.
The nitrate ion concentration is preferably 0.5 to 20 g / L, and more preferably 0.8 to 6 g / L. Within the above range, the uniformity of the pits becomes high.

Chloride ions can be contained in the aqueous solution by using hydrochloric acid as a raw material of the aqueous solution. In addition, chlorides such as aluminum chloride, sodium chloride, and ammonium chloride can be used. Of these, aluminum chloride is preferably used. In the present invention, it is preferable to use both hydrochloric acid and chloride, and it is more preferable to use hydrochloric acid and aluminum chloride. When hydrochloric acid is used, the hydrochloric acid concentration is preferably from 3 to 30 g / L, more preferably from 4 to 20 g / L, and even more preferably from 5 to 18 g / L.
Nitrate ions can be contained in the aqueous solution by using nitric acid as a raw material of the aqueous solution. Also, nitrates such as aluminum nitrate, sodium nitrate, ammonium nitrate can be used. When nitric acid is used, the nitric acid concentration is preferably 0.5 to 15 g / L, and more preferably 1 to 10 g / L.

  By containing nitrate ions in the aqueous solution used as the electrolyte, pits having an average diameter of 1 to 5 μm are formed on the surface of the aluminum plate, and chloride ions are contained in the surface of the aluminum plate. A pit of 01 to 0.5 μm is formed. Therefore, when the aqueous solution does not contain nitrate ions or hydrochloric acid ions, an aluminum plate having a surface shape in which pits having an average diameter of 1 to 5 μm and pits having an average diameter of 0.01 to 0.5 μm are superimposed can be obtained. become unable.

  Moreover, it is preferable that the aqueous solution used as electrolyte is pH 0.8 or less. When the pH is 0.8 or less, the uniformity of pits becomes higher.

The aqueous solution used as the electrolyte may contain sulfuric acid.
In addition to sulfuric acid, the aqueous solution can contain a sulfuric acid compound having sulfate ions such as aluminum sulfate, sodium sulfate, and ammonium sulfate.
Moreover, the compound which forms a complex with copper can also be contained in the ratio of 1-200 g / L. In the mixed aqueous solution, a metal contained in an aluminum alloy such as iron, copper, manganese, nickel, titanium, magnesium, or silica may be dissolved. Hypochlorous acid or hydrogen peroxide may be contained in an amount of 1 to 100 g / L.

The aluminum ion concentration in the aqueous solution is preferably 2 g / L or more, more preferably 3 to 30 g / L, still more preferably 3 to 20 g / L, and 4 to 18 g / L. Further preferred. Within the above range, the uniformity of the pits becomes high. Moreover, it can avoid that the replenishment amount of aqueous solution increases too much.
Aluminum ions in the aqueous solution can be contained by dissolving an aluminum salt in the aqueous solution. As the aluminum salt, aluminum chloride, aluminum nitrate, aluminum sulfate, or the like can be used. Among them, the use of aluminum chloride or aluminum nitrate containing chloride ion or nitrate ion contained in the aqueous solution has a good pit shape. This is preferable.

The concentration control of each component of the electrolytic solution is preferably performed using a combination of a multi-component concentration measurement method such as a concentration measurement method, feedforward control and feedback control. Thereby, accurate concentration management of the electrolytic solution becomes possible.
Multi-component concentration measurement methods include, for example, a method of concentration using the ultrasonic wave propagation velocity in the electrolyte and the conductivity (conductivity) C of the electrolyte, neutralization titration, capillary electrophoresis analysis, isotacho Examples thereof include foresis (isotaphoresis, capillary isotachophoresis) analysis method and ion chromatography method.

  The ion chromatograph method is classified into an absorbance detection ion chromatograph, a non-suppressor type electric conductivity detection ion chromatograph, a suppressor type ion chromatograph, and the like depending on the type of detector. Among these, a suppressor type ion chromatograph is preferable from the viewpoint of ensuring measurement stability.

Current density in electrochemical graining treatment, the peak current value is preferably from 10~300A / dm ^2, more preferably from 15~200A / dm ^2, in 20~125A / dm ² More preferably. Productivity will become more excellent in it being 10 A / dm < ² > or more. When it is 300 A / dm ² or less, the voltage is not high and the power source capacity does not become too large, so that the power source cost can be reduced.

  For the electrochemical surface roughening treatment, for example, an electrochemical grain method (electrolytic grain method) described in Japanese Patent Publication No. 48-28123 and British Patent No. 896,563 can be used.

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-52-13338, 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.

  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 mixed aqueous solution is preferably 20 ° C. or higher, more preferably 25 ° C. or higher, further preferably 30 ° C. or higher, preferably 60 ° C. or lower, and 50 ° C. or lower. More preferably, it is 40 ° C. or less. When the temperature is 20 ° C. or higher, the refrigerator operating cost for cooling does not increase, and the amount of groundwater used for cooling can be suppressed. It is easy to ensure the corrosion resistance of equipment as it is 60 ° C. or lower.

The AC power supply wave used for the 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.
The frequency is preferably 10 to 200 Hz, more preferably 20 to 150 Hz, and still more preferably 50 to 60 Hz. When it is 10 Hz or more, it is difficult to form a large facet-shaped (pitched square shape) pit, and the stain resistance is further improved. If it is 200 Hz or less, it is difficult to be influenced by the inductance component of the circuit through which the electrolytic current flows, and it becomes easy to manufacture a large-capacity power supply.

  The trapezoidal wave refers to that shown in FIG. In the trapezoidal wave, the time TP until the current reaches a peak from zero is preferably 0.3 to 2.0 msec, and more preferably 0.5 to 0.8 msec. If it is 0.3 msec or more, the production cost of the power supply is lowered. When it is 2 msec or less, the uniformity of pits becomes more excellent. In the triangular wave, the current rise time can be arbitrarily set.

  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 an aluminum plate, When the voltage is changed with respect to the fluctuation of the concentration of each component and the like, and the current value (current density of the aluminum plate) is controlled to be constant, it is preferable in terms of excellent followability.

FIG. 4 is a side view showing an example of a radial type cell used for electrochemical surface roughening using alternating current in the method for producing a lithographic printing plate support of the present invention.
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 value 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 the aluminum plate facing the main electrode has an anode current value And the current value at the cathode can be controlled. The current ratio (ratio of the total amount of electricity when the aluminum plate is the anode and the total amount of electricity when the aluminum plate is the cathode) is preferably 0.9 to 3, preferably 0.9 to 1.0. More preferably.

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 web.
The electrolytic cell may be divided into a plurality. When the electrolytic cell is divided into a plurality of parts, the electrolytic conditions of the respective electrolytic cells may be the same or different.

After the 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 interval 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.

<Second etching process>
After the electrochemical roughening treatment, it is preferable to perform a second etching treatment. The second etching process is performed for the purpose of dissolving the smut generated by the electrochemical roughening process and dissolving the edge portion of the pit formed by the electrochemical roughening process. As a result, the edge portion of the large pit formed by the electrochemical surface roughening treatment is melted and the surface becomes smooth, and the ink is less likely to be caught on the edge portion, so that a lithographic printing plate precursor having excellent stain resistance is obtained. be able to.

The second etching process is basically the same as the first etching process, but the aluminum ion concentration contained in the alkaline solution is preferably 0.1 to 10% by mass. In particular, an alkali solution having a concentration of 4 to 8% by mass of aluminum ions and a concentration of 20 to 40% by mass or an alkali solution having a concentration of 0.3 to 0.7% by mass of aluminum ions and 4 to 6% is used. preferable. The liquid temperature is more preferably 30 to 80 ° C.
The etching amount is preferably at 0.01 g / m ² or more, more preferably 0.05 g / m ² or more, still more preferably at 0.1 g / m ² or more, also 10 g / M ² or less is preferable, 3 g / m ² or less is more preferable, and 0.3 g / m ² or less is more preferable.

<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. The second desmut process is basically the same as the first desmut process.
In the second desmut process, when the same type of electrolyte as that used in the subsequent anodizing process is used as the desmut process liquid, the draining with a nip roller and the water washing process can be omitted after the desmut process.
The second desmut treatment is preferably performed in an electrolytic cell in which an aluminum plate is subjected to a cathode reaction treatment in an anodizing treatment apparatus used for anodizing treatment described later. If it does in this way, since it becomes unnecessary to provide an independent desmut processing tank for the 2nd desmut processing, equipment cost can be reduced.

<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 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 second and third components 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 electrolyte is conducted using the same method as in the case of nitric acid electrolysis described above, and the conductivity, specific gravity and temperature, or conductivity and ultrasonic wave propagation corresponding to the matrix of sulfuric acid concentration and aluminum ion concentration. It is preferable to control by speed and 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 as not to cause so-called “burn” (part where the film becomes thicker than the surrounding area) due to current concentration on a part of the aluminum plate, 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 process is continuously performed, it is preferable to perform the liquid feeding method in which the aluminum plate is fed with an electrolyte.
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 . When it is 1 g / m ² or more, the plate is hardly damaged. If it is 5 g / m ² or less, a large amount of electric power is not required for production, which is economically advantageous. 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.
Moreover, it is preferable that the quantity of the anodic oxide film of the back surface of the surface which performed the electrochemical roughening process is 0.1-1 g / m < ² >. When it is 0.1 g / m ² or more, the back surface is less likely to be scratched, and the image recording layer that comes into contact with the back surface is less likely to be scratched as a lithographic printing plate precursor. When it is 1 g / m ² or less, it is economically advantageous.

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 as viewed 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.
When anodizing treatment is performed, one anodizing apparatus 410 may be used, but 2 to 5 anodizing apparatuses 410 are arranged in series in the traveling direction of the aluminum plate and continuously processed. It is preferable to do. If two to five anodizing apparatuses 410 are arranged in series in the traveling direction of the aluminum plate and continuously processed, it is effective in performing high-speed processing and reducing power consumption.

<Sealing treatment>
In this invention, you may perform the sealing process which seals the micropore which exists in an anodic oxide film as needed. By performing the sealing treatment, the developability (sensitivity) of the lithographic printing plate precursor can be improved.
It is well known that the anodized film is a porous film having pores called pores in a direction substantially perpendicular to the film surface. In the present invention, it is preferable to subject the anodizing treatment to a sealing treatment with a high sealing ratio. The sealing rate is preferably 50% or more, more preferably 70% or more, and further preferably 90% or more. Here, the “sealing rate” is defined by the following formula.

  Sealing rate = (surface area before sealing−surface area after sealing) / surface area before sealing × 100%

  The surface area can be measured using, for example, a simple BET surface area measuring device (for example, QUANTASORB (manufactured by Kantha Sorb), manufactured by Yuasa Ionics).

  The sealing treatment is not particularly limited, and a conventionally known method can be used. For example, hydrothermal treatment, boiling water treatment, steam treatment, dichromate treatment, nitrite treatment, ammonium acetate salt treatment, electrodeposition sealing treatment, and the like described in JP-B 36-22063. Zirconate treatment, treatment with an aqueous solution containing a phosphate and an inorganic fluorine compound described in JP-A-9-244227, treatment with an aqueous solution containing a sugar described in JP-A-9-134002 , Treatment with an aqueous solution containing titanium and fluorine described in JP-A-2000-81704 and JP-A-2000-89466, alkali metal silica described in US Pat. No. 3,181,461, etc. Examples include acid salt treatment.

  An example of a suitable sealing treatment is an alkali metal silicate treatment. The alkali metal silicate treatment is performed using an alkali metal silicate aqueous solution having a pH of 10 to 13 at 25 ° C. without causing gelation of the liquid and dissolution of the anodized film. Processing conditions such as temperature and processing time can be selected as appropriate. Suitable alkali metal silicates include, for example, sodium silicate, potassium silicate, and lithium silicate. Moreover, sodium hydroxide, potassium hydroxide, lithium hydroxide, etc. can be mix | blended in order to adjust pH of alkali metal silicate aqueous solution high.

Furthermore, you may mix | blend an alkaline-earth metal salt and / or a group 4 (Group IVA) metal salt with alkali metal silicate aqueous solution as needed. Examples of the alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate; sulfates, hydrochlorides, phosphates, acetates, oxalates, and boric acids of alkaline earth metals. Examples thereof include water-soluble salts such as salts. Examples of the Group 4 (Group IVA) metal salt include titanium tetrachloride, titanium trichloride, potassium fluoride titanium, potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride. And zirconium tetrachloride. Alkaline earth metal salts and Group 4 (Group IVA) metal salts can be used alone or in combination of two or more.
The concentration of the alkali metal silicate aqueous solution is preferably 0.01 to 10% by mass, and more preferably 0.05 to 5.0% by mass.

Another example of a suitable sealing treatment is a fluorinated zirconic acid treatment. The fluorinated zirconate treatment is performed using a fluorinated zirconate salt such as sodium fluorinated zirconate or potassium fluorinated zirconate. Among these, it is preferable to use sodium fluorinated zirconate. Thereby, the developability (sensitivity) of the lithographic printing plate precursor becomes excellent. The concentration of the fluorinated zirconic acid solution used for the fluorinated zirconic acid treatment is preferably 0.01 to 2% by mass, and more preferably 0.1 to 0.3% by mass.
The fluorinated zirconate solution preferably contains sodium dihydrogen phosphate. The concentration of sodium dihydrogen phosphate is preferably 0.01 to 3% by mass, and more preferably 0.1 to 0.3% by mass.
The fluorinated zirconate solution may contain aluminum ions. In that case, the aluminum ion concentration of the fluorinated zirconate solution is preferably 1 to 500 mg / L.

The temperature for the sealing treatment is preferably 20 to 90 ° C, and more preferably 50 to 80 ° C.
The sealing treatment time (immersion time in the solution) is preferably 1 to 20 seconds, and more preferably 5 to 15 seconds.

  In addition, after performing a sealing treatment as necessary, a polymer or copolymer having the above-mentioned alkali metal silicate treatment, polyvinylphosphonic acid, polyacrylic acid, sulfo group or the like in the side chain, JP-A-11-231509 A surface treatment such as a treatment of immersing or coating in a solution containing an organic compound having an amino group and a group selected from the group consisting of a phosphine group, a phosphone group, and a phosphoric acid group or a salt thereof described in the publication be able to.

  After the sealing treatment, it is preferable to perform a hydrophilic treatment described later.

<Hydrophilic treatment>
A hydrophilization treatment may be performed 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 or organic acids of amino acids described in JP-A-63-130391, JP-A-63-145092 Organic phosphonic acids containing a carboxy group or hydroxy group, compounds having an amino group and a phosphonic acid group described in JP-A-63-165183, and JP-A-2-316290 Specific carboxylic acid derivatives, phosphate esters described in JP-A-3-215095, JP-A-3-261592 Compounds having one amino group and one oxygen acid group of phosphorus described in the publication, phosphoric esters described in JP-A-3-215095, and JP-A-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, phosphorus described in JP-A-4-282737 Examples of the treatment include undercoating using a compound having a group of oxygen acids.
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. 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 the Group 4 (Group IVA) metal salt include titanium tetrachloride, titanium trichloride, potassium fluoride titanium, potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride. And zirconium tetrachloride. 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 with a fluorescent X-ray analyzer, and the amount of adsorption is preferably about 1.0 to 15.0 mg / m ² .
By this alkali metal silicate treatment, the effect of improving the dissolution resistance to the alkaline developer on the surface of the lithographic printing plate support is obtained, the dissolution of the aluminum component into the developer is suppressed, and the developer fatigue It is possible to reduce the occurrence of development residue due to the above.

The hydrophilization 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 hydrophilic compounds that may be used in this method include, -NH ₂ group, compounds having at least one selected from the group consisting of -COOH group and sulfo group.

<Dry>
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 1 second or longer, more preferably 2 seconds or longer, more preferably 20 seconds or shorter, and even more preferably 15 seconds.

[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”), a negative photosensitive composition containing a diazo resin or a photocrosslinking resin (hereinafter also referred to as “conventional negative type”), and a positive photosensitive composition containing a 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”). Referred to as "non-treatment type".) It can be mentioned as, in particular, thermal positive type, thermal negative type, non-treatment type is preferred. 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, a polymer compound described in JP-A No. 2001-305722 (particularly [0023] to [0042]) and a repeat 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 from the viewpoint 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 can contain a dissolution inhibitor. As the dissolution inhibitor, for example, a dissolution inhibitor as described in JP-A-2001-305722, [0053] to [0055] is 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 as described in [0056] to [0060] of JP-A No. 2001-305722 are preferable.
The photosensitive composition described in detail by Unexamined-Japanese-Patent No. 2001-305722 is preferably used also in respects other than the above.

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 for 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 [0062] to [0085] of JP-A-2002-3233769 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 photothermal 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].
Preferable 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 radically 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. Preferable 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 crosslinking layer comprises a photothermal conversion substance, a thermal acid generator, a compound that crosslinks with an acid that is a curable compound (crosslinking agent), and an alkali-soluble polymer compound that can react with the crosslinking agent in the presence of an acid. contains. In the acid cross-linking layer, infrared light absorbed by the light-to-heat conversion substance is converted into heat, and the thermal 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 photopolymerization initiators can be appropriately selected depending on the wavelength of the light source to be used. For example, the initiation system described in JP-A-2001-22079, [0021] to [0023] is preferable.
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 the image recording layer needs to be dissolved 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 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 condensates of aromatic diazonium salts and active carbonyl group-containing compounds such as formaldehyde; condensates of p-diazophenylamines and formaldehyde with hexafluorophosphate or tetrafluoroborate. An organic solvent-soluble diazo resin inorganic salt which is a reaction product 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, multi-component copolymers of monomers such as 2-hydroxyethyl (meth) acrylate, (meth) acrylonitrile, and (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 made into a lithographic printing plate by various treatment methods according to the image recording layer.
Examples of the active 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 a helium-neon laser (He-Ne laser), an argon laser, a krypton laser, a helium-cadmium laser, a KrF excimer laser, a semiconductor laser, a YAG laser, and a 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.
1. Manufacture of roll for embossing of aluminum plate The following treatments (1) to (5) were sequentially performed using a roll made of tool steel (SKD11) and Hv750 to obtain each roll for embossing of aluminum plate.

(1) Mirror polishing treatment A buffing treatment was performed as a mirror polishing treatment to remove traces of the grindstone that polished the roll surface. On the polished surface, the average roughness _Ra was 0.2 μm, and the maximum height R _max was 1 μm. The average roughness R _a and the maximum height R _max were measured according to the measurement of the arithmetic average roughness R _a and the maximum height R _y of JIS B0601-1994 respectively.

(2) Blasting treatment The surface of the roll was roughened by performing an air blasting process using # 80 mesh alumina particles as a grid material twice. The spray pressure was 2 kgf / cm ² (1.96 × 10 ⁵ Pa) for each time of the air blast method. On the surface after the blast treatment, the average roughness _Ra was 0.8 μm.

(3) Degreasing treatment It was immersed in a degreasing tank having a liquid temperature of 30 ° C. for 30 seconds, and the oil on the surface was removed with the degreasing solution. Then, it washed with water, air was sprayed, and the water | moisture content was removed.

(4) Electrolytic treatment In an electrolytic solution containing chromic acid 300 g / L, sulfuric acid 2 g / L, and iron 1 g / L at a liquid temperature of 50 ° C., continuous DC current is applied and electrolysis is performed at a current density of 30 A / dm ^{2 using} the roll as the anode. Processed. Electric quantity of electrolytic treatment was 10,000 C / dm ^2.
The current waveform used was a three-phase full-wave rectification and a direct current with a ripple component of 5% or less through a filter circuit. The counter electrode was lead. The roll was placed vertically in the electrolyte, and a lead electrode was arranged in a cylindrical shape so as to surround the periphery. The shaft portion of the roll was masked with vinyl chloride so that no electrolytic treatment was performed.

(5) Chromium plating treatment Next, a continuous direct current was applied in an electrolytic solution containing chromic acid 300 g / L, sulfuric acid 2 g / L, and iron 1 g / L at a temperature of 50 ° C., and the current density was 40 A / a plating treatment was carried out at dm ^2. The plating treatment time was set so that the plating thickness was 6 μm.
The current waveform used was a three-phase full-wave rectification and a direct current with a ripple component of 5% or less through a filter circuit. The counter electrode was lead. The roll was placed vertically in the electrolyte, and a lead electrode was arranged in a cylindrical shape so as to surround the periphery. The shaft portion of the roll was masked with vinyl chloride so as not to be plated.

2. Manufacture of an aluminum plate Each component (mass%) shown in Table 1 is contained, and the balance is prepared by using an aluminum alloy composed of Al and inevitable impurities. An ingot having a thickness of 500 mm and a width of 1200 mm was prepared by a DC casting method. After the surface was shaved with a chamfering machine with an average thickness of 10 mm, the temperature was kept constant 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 using a continuous annealing machine at 500 degreeC, it cold-rolled and finished to thickness 0.3mm and width 1060mm, and obtained the aluminum plates 1-3.
Moreover, in cold rolling, the aluminum plates 4-6 were each obtained by the method similar to each of the aluminum plates 1-3 except having used the roll for aluminum plate embossing obtained above.

3. Preparation of lithographic printing plate support (Example 1-1 to Example 1-38, Example 3-1 to 3-7, Example 3-9, Comparative Example 1-1 to 1-2)
The aluminum plate obtained above was subjected to the following surface treatment to obtain each lithographic printing plate support shown in Table 2.

<Surface treatment>
The surface treatment was performed by continuously performing the following various treatments (a) to (j).

(A) Etching treatment in alkaline aqueous solution (first etching treatment)
The aluminum plate was etched by spraying an aqueous solution having a caustic soda concentration of 370 g / L, an aluminum ion concentration of 100 g / L, and a temperature of 60 ° C. from a spray tube. The etching amount of the surface subjected to electrochemical roughening after the aluminum plate was 3 g / m ² .
Then, the liquid was drained with a nip roller, and further washed with water for 5 seconds using a spray tube having a spray tip in which spray water spread in a fan shape, and further drained with a nip roller.

(B) Desmut treatment in acidic aqueous solution (first desmut treatment)
The aluminum plate was sprayed with an aqueous solution having a sulfuric acid concentration of 170 g / L, an aluminum ion concentration of 5 g / L, and a temperature of 50 ° C. from a spray tube, and desmutted for 5 seconds. As the sulfuric acid aqueous solution, the waste liquid of the (i) anodizing treatment step described later was used.
Then, the liquid was drained with a nip roller, and further washed with water for 5 seconds using a spray tube having a spray tip in which spray water spread in a fan shape, and further drained with a nip roller.

(C) Electrochemical roughening treatment using alternating current in acidic aqueous solution (electrochemical roughening treatment)
As the electrolyte, an aqueous solution of chloride ion concentration, nitrate ion concentration, aluminum ion concentration and pH shown in Table 2 (temperature 35 ° C.) was used, the current was controlled by inverter control using an IGBT element, and an arbitrary waveform Using a power source capable of generating alternating current, an electrochemical roughening treatment was performed on the aluminum plate subjected to the treatment (b).
The chloride ion concentration was adjusted using hydrochloric acid and / or aluminum chloride, the nitrate ion concentration was adjusted using nitric acid, and the aluminum ion concentration was adjusted using aluminum chloride.
The waveform of the current used, the rise time when the waveform is a trapezoidal wave, the frequency of the current used, the amount of electricity, and the current ratio were as shown in Table 2. The amount of electricity is the total amount of electricity when the aluminum plate is the anode, and the current ratio is the ratio of the amount of electricity when the aluminum plate is the cathode and the amount of electricity when the aluminum plate is the anode.
Further, the current density when the aluminum plate was an anode at the peak of alternating current was 50 A / dm ² . The duty was 0.5.
Concentration control of the electrolyte is performed according to the data table obtained in advance, adding chloride ions, nitrate ions and water in proportion to the energization amount, and performing multi-component concentration measurement by capillary electrophoresis analysis. A method of correcting the addition amount of chloride ion, nitrate ion and water was used.
Then, the liquid was drained with a nip roller, and further washed with water for 5 seconds using a spray tube having a spray tip in which spray water spread in a fan shape, and further drained with a nip roller.

(D) Etching treatment in alkaline aqueous solution (second etching treatment)
Etching was performed by spraying an aqueous solution of caustic soda concentration of 50 g / L, aluminum ion concentration of 5 g / L, and a temperature of 35 ° C. onto the aluminum plate from a spray tube. The etching amount of the surface of the aluminum plate subjected to the electrochemical roughening treatment was as shown in Table 2.
Then, the liquid was drained with a nip roller, and further washed with water for 5 seconds using a spray tube having a spray tip in which spray water spread in a fan shape, and further drained with a nip roller.

(E) Desmut treatment in acidic aqueous solution (second desmut treatment)
The aluminum plate was sprayed with an aqueous solution having a sulfuric acid concentration of 170 g / L, an aluminum ion concentration of 5 g / L, and a temperature of 50 ° C. from a spray tube, and desmutted for 5 seconds. As the sulfuric acid aqueous solution, the waste liquid of the (i) anodizing treatment step described later was used.
Then, the liquid was drained with a nip roller, and further washed with water for 5 seconds using a spray tube having a spray tip in which spray water spread in a fan shape, and further drained with a nip roller.

(F) Anodizing treatment As an electrolytic solution, an electrolytic solution (temperature 50 ° C.) in which aluminum sulfate was dissolved in a 170 g / L sulfuric acid aqueous solution to make an 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 15 A / dm ² , and the final oxide film amount was 2.7 g / m ² .
Then, the liquid was drained with a nip roller, and further washed with water for 5 seconds using a spray tube having a spray tip in which spray water spread in a fan shape, and further drained with a nip roller.

(G) Hydrophilization treatment An aluminum plate was immersed in a 1 % by mass aqueous solution of sodium silicate (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 .
Then, the liquid was drained with a nip roller, and further washed with water for 5 seconds using a spray tube having a spray tip in which spray water spread in a fan shape, and further drained with a nip roller. Furthermore, 90 degreeC wind was sprayed for 10 seconds, and it was made to dry, and the support body for lithographic printing plates was obtained.

(Examples 2-1 to 2-4, Example 3-8)
Example 1-1 is performed except that the following (z) is performed before (a), and the etching amount of the surface subjected to electrochemical roughening after the aluminum plate in (a) is 10 g / L. The lithographic printing plate support of Examples 2-1 to 2-4 shown in Table 2 was obtained in the same manner as in Example 1-38.

(Z) Mechanical roughening treatment Using an apparatus as shown in FIG. 6, a suspension of slurry (pumice) and water (specific gravity 1.12) is supplied to the surface of the aluminum plate as a polishing slurry. However, a mechanical surface roughening treatment was performed with a rotating roller-like nylon brush. In FIG. 6, 1 is an aluminum plate, 2 and 4 are roller brushes, 3 is a polishing slurry, and 5, 6, 7 and 8 are support rollers. The average particle size of the abrasive was 30 μm. The material of the nylon brush was 6 · 10 nylon, the hair length was 50 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The rotation speed of the brush was 200 rpm. _Ra after the mechanical surface roughening treatment was 0.45 μm.

4). Observation of the surface of a lithographic printing plate support The lithographic printing plate support obtained in Examples 1-1 to 1-38, Examples 2-1 to 2-4, and Examples 3-1 to 3-4 The surface shape was observed with a scanning electron microscope (JSM-5500, manufactured by JEOL Ltd., the same shall apply hereinafter) at a magnification of 50000 times. It was generated. Further, when observed with a scanning electron microscope at a magnification of 2000, irregularities having a diameter of 1 to 5 μm were formed on the surfaces of these lithographic printing plate supports. Fine irregularities having a diameter of 0.01 to 0.5 μm were generated by being superimposed on irregularities having a diameter of 1 to 5 μm. Moreover, the unevenness | corrugation of diameter 1-5 micrometers was generally produced | generated independently, without overlapping, and was uniform.
On the other hand, when the surface shape of the lithographic printing plate support obtained in Comparative Examples 1 and 2 was observed in the same manner, fine irregularities with a diameter of 0.01 to 0.5 μm and a diameter of 1 to Although unevenness of 5 μm was generated, the unevenness of 1 to 5 μm in diameter was uneven because many of the unevenness overlapped with each other at the peripheral edge as compared with the example.

5. 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. Before providing the image recording layer, an undercoat layer was provided as described later.
On the lithographic printing plate support, an undercoat solution having the following composition was applied and dried at 80 ° C. for 15 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

Furthermore, a heat-sensitive layer coating solution having the following composition was prepared, and the coating amount after drying the heat-sensitive layer coating solution (heat-sensitive layer coating amount) on a lithographic printing plate support provided with an undercoat layer was 1.8 g / m. ² was applied and dried to form a heat sensitive layer (thermal positive type image recording layer) to obtain a lithographic printing plate precursor.

<Thermosensitive layer coating solution 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 & Chemicals, Inc., 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

6). Evaluation of planographic printing plate precursor The printing durability, stain resistance, and shiny of the planographic printing plate were evaluated by the following methods.

(1) Printing durability The obtained lithographic printing plate precursor was imaged using a TrendSetter 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 alkaline developer having the following composition, the solution was maintained at 30 ° C. and developed for 20 seconds to obtain a lithographic printing plate. The sensitivity of all the lithographic printing plate precursors was good.

<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 C: less than 10,000

(2) Stain resistance Using a planographic printing plate obtained in the same manner as in the case of (1) Evaluation of printing durability, DIC-GEOS (s) is used with a Mitsubishi diamond type F2 printer (manufactured by Mitsubishi Heavy Industries, Ltd.). Printing was carried out using red ink, 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. B: The blanket is dirty but within the allowable range. C: The blanket is dirty and the printed matter is clearly dirty.

(3) 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 non-image of the printing plate is reduced while reducing the amount of dampening water supplied. The brightness of the part was observed visually, and shiny (easy to see the rising of water) was evaluated by the supply amount of dampening water when it began to shine.
The results are shown in Table 2. The meanings of the symbols in Table 2 are as follows.
A: When fountain solution is squeezed, the plate surface is difficult to shine.
B: When the fountain solution is squeezed, the plate surface tends to shine, and visual adjustment of the fountain solution is somewhat difficult.

As is apparent from Table 2, the method for producing a lithographic printing plate support of the present invention (Examples 1-1 to 1-38, Examples 2-1 to 2-4, Examples 3-1 to 3- The lithographic printing plates using the lithographic printing plate support obtained in 4) were all excellent in printing durability and stain resistance, and also excellent in shiny.
Moreover, when the unevenness | corrugation is formed in the surface by press-contacting the aluminum plate embossing roll before a 1st etching process (Examples 1-1 to 1-18, Example 1-37), and before a 1st etching process In the case where irregularities are formed on the surface by subjecting the surface to mechanical roughening (Examples 2-1 to 2-4, Example 3-8), a lithographic plate using the obtained lithographic printing plate support The printing plate was particularly excellent in shiny.
On the other hand, in Comparative Example 1-1 in which the total amount of electricity at the anode of the aluminum plate in the electrochemical surface roughening treatment is too large, the lithographic printing plate using the obtained lithographic printing plate support is resistant. It was inferior to dirtiness.
Moreover, in Comparative Example 1-2 in which the pH of the aqueous solution used for the electrochemical surface treatment was too high, the obtained lithographic printing plate support had insufficient pit dispersion, and the pit size was too small. Since it was non-uniform and formed with large concave portions, it was inferior in stain resistance and inferior in printing durability and shiny.

It is typical sectional drawing of the apparatus which performs the water washing process with the free-fall curtain-like liquid film used for the water washing process in the manufacturing method of the lithographic printing plate support of this invention. It is typical sectional drawing which shows the aluminum plate in which the unevenness | corrugation formed by a pit with an average diameter of 1-5 micrometers and a pit with an average diameter of 0.01-0.5 micrometers formed. It is a graph which shows an example of the waveform of the alternating current 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 a side view which shows the concept of the process of the mechanical roughening 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 (6)

Electrochemical roughening is performed by passing an alternating current through the aluminum plate in an aqueous solution containing at least chloride ions and nitrate ions so that the total amount of electricity when the aluminum plate is an anode is 100 to 300 C / dm ^2. A method for producing a support for a lithographic printing plate, wherein a surface treatment is performed to obtain a support for a lithographic printing plate.   The method for producing a lithographic printing plate support according to claim 1, wherein the aqueous solution contains hydrochloric acid and nitric acid.   The method for producing a lithographic printing plate support according to claim 1 or 2, wherein the aqueous solution has a chloride ion concentration of 3 g / L or more and a nitrate ion concentration of 0.50 g / L or more.   The method for producing a lithographic printing plate support according to any one of claims 1 to 3, wherein the aqueous solution has a pH of 0.8 or less.   The method for producing a lithographic printing plate support according to any one of claims 1 to 4, wherein the aqueous solution contains 2 g / L or more of aluminum ions.   The manufacturing method of the support body for lithographic printing plates in any one of Claims 1-5 in which the said aluminum plate has an uneven | corrugated pattern on the surface.

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