JP2005007857A - Method for manufacturing support of lithographic printing plate and support - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a support for a lithographic printing plate, which makes it possible to obtain an original lithographic printing plate showing superb sensitivity, smudge resistance and printing durability. <P>SOLUTION: This method manufactures the support for the lithographic printing plate using an aluminum sheet with an unevenness formed on the surface by transferring an uneven pattern, through treatments such as (1) electrochemical surface roughing in an aqueous nitric acid solution, (2) electrochemical surface roughing in an aqueous hydrochloric acid solution and (3) anodic oxidation. <P>COPYRIGHT: (C)2005,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 support for a lithographic printing plate used for a lithographic printing plate precursor having excellent sensitivity, stain resistance and printing durability.

  An aluminum support for a lithographic printing plate (hereinafter simply referred to as “support for a lithographic printing plate”) used in a lithographic printing plate is produced by subjecting an aluminum plate to a surface roughening treatment or other surface treatment. Examples of the roughening treatment include mechanical roughening treatment, electrochemical roughening treatment (hereinafter also referred to as “electrolytic roughening treatment”), and chemical roughening treatment (chemical etching). A processing method combining these is known.

Among these, the mechanical surface roughening treatment is effective for improving the printing durability of the lithographic printing plate. As a mechanical surface roughening treatment, a method of spraying an abrasive slurry between a rotating nylon brush and an aluminum plate is generally known.
However, this method using a nylon brush and an abrasive has the advantage that it can be carried out at a high speed and at a low cost. On the other hand, it is difficult to control the particle size of the abrasive. Deep recesses are easily generated. As a result, if there are locally deep recesses on the surface of the lithographic printing plate support, it is difficult for the lithographic printing plate provided with a positive image recording layer to develop locally deep portions of the non-image area. Problems arise. Further, in the planographic printing plate provided with the negative type image recording layer, there is a problem that a locally deep portion of the image portion is difficult to be formed as an image.
In addition, since the method using a nylon brush and an abrasive physically roughens, a sharpened portion is generated. Therefore, in order to smooth the portion, a large amount of aluminum is added by an alkali etching treatment in a later step. Must be dissolved. Therefore, there is a problem that the cost is high and the load on the environment is large.

Specifically, Patent Document 1 discloses an electrochemical roughening on a rolled and embossed aluminum support having a surface structure with pits having an average diameter of 10 to 60 μm, preferably 20 to 24 μm. A printing plate is described in which a depression microstructure having a depression diameter in the range of 0.1 to 6 μm, produced by surfaceization, is superimposed on this surface structure.
In Patent Document 2, an aluminum plate pre-engraved containing a hemispherical indent having a diameter of 2 to 50 μm and an average diameter of 20 to 30 μm is selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid and chlorides of aluminum salts or nitrate ions. A lithographic printing plate support roughened in the electrolyte of choice is described. The surface roughness Ra after the roughening is uniform and covers the entire area and is 1.0 to 1.5 μm.
In Patent Document 3, an aluminum plate is roughened by transfer using a rolling roll, and a pretreatment layer made of acrylic acid, methacrylic acid, an organic phosphorus polymer, or a copolymer thereof is provided thereon, and a photosensitive layer is provided. A lithographic printing plate precursor with improved adhesion to is described.

  The methods described in these prior arts tend to generate uniform irregularities compared to the roughening method using a nylon brush and an abrasive, but have the disadvantage of poor printing durability due to the large pitch of the irregularities. was there.

JP 2002-240448 A, JP 2002-38300 A, WO02 / 19032 Publication

  Therefore, there has been a demand for a method for improving the sensitivity, stain resistance, and printing durability by solving the above-described problem of locally deep recesses.

  The present invention solves these problems of the prior art, and a lithographic printing plate support from which uniform unevenness can be easily obtained and a lithographic printing plate precursor excellent in sensitivity, stain resistance and printing durability can be obtained. (Hereinafter, it may only be called a support body) and its manufacturing method.

 The present inventors perform sensitivity roughening, dirt resistance, and resistance by carrying out electrochemical roughening in at least two steps using an aluminum plate having unevenness formed on the surface by transferring the unevenness pattern. It has been found that a lithographic printing plate support that can be used as a lithographic printing plate having excellent printing power can be obtained.

  That is, the present invention provides the following [1] to [7].

[1] By using an aluminum plate having irregularities formed on its surface by transferring an irregular pattern,
(1) Electrochemical roughening treatment in aqueous nitric acid solution,
(2) Electrochemical roughening treatment in aqueous hydrochloric acid,
(3) A method for producing a support for a lithographic printing plate, which is anodized.
[2] By using an aluminum plate having irregularities formed on the surface by transferring an irregular pattern,
(1) Chemical etching treatment in alkaline aqueous solution,
(2) Desmut treatment in acidic aqueous solution
(3) Electrochemical roughening treatment in aqueous nitric acid solution,
(4) Chemical etching treatment in alkaline aqueous solution,
(5) Desmut treatment in acidic aqueous solution
(6) Electrochemical roughening treatment in aqueous hydrochloric acid,
(7) Chemical etching treatment in alkaline aqueous solution,
(8) Desmut treatment in acidic aqueous solution
(9) A method for producing a support for a lithographic printing plate, which is anodized.
[3] By transferring the concavo-convex pattern, pits having an average opening diameter of 0.5 to 5 μm and pits having an average opening diameter of 0.05 to 0.3 μm are superimposed on the concavo-convexities of the aluminum plate having the unevenness formed on the surface. And a method for producing a lithographic printing plate support, which is further subjected to an anodizing treatment or an anodizing treatment and a hydrophilization treatment.
[4] The method for producing a lithographic printing plate support according to any one of 1 to 3, wherein the aluminum plate having irregularities formed on the surface is an aluminum plate containing 0.020 to 0.2% by mass of Cu. .
[5] The method for producing a lithographic printing plate support according to any one of the above 1 to 4, wherein the concavo-convex pattern is transferred in the final rolling step of the aluminum plate production step.
[6] The method for producing a lithographic printing plate support according to any one of the above 1 to 5, wherein the anodizing treatment is followed by a hydrophilization treatment.
[7] A lithographic printing plate precursor further having an image recording layer on the support obtained by any one of the production methods 1 to 6 above.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the support body for lithographic printing plates from which the lithographic printing plate precursor which is excellent in all of sensitivity, stain resistance, and printing durability is obtained is provided.

Hereinafter, the present invention will be described in detail.
[Method for producing support for lithographic printing plate]
<Aluminum plate (rolled aluminum)>

  The aluminum plate used in the present invention is a metal whose main component is dimensionally stable aluminum, and is made of aluminum or an aluminum alloy. In addition to a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements can also be used.

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

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.

The aluminum plate used in the method for producing a lithographic printing plate support of the present invention preferably contains 0.020 to 0.2% by mass of Cu. When the Cu content of the aluminum plate is within this range, relatively large and more uniform recesses are formed in nitric acid alternating current electrolysis described later. As a result, the lithographic printing plate using the obtained lithographic printing plate support is more excellent in printing durability.
The Cu content is more preferably 0.15% by mass or less, more preferably 0.12% by mass or less in terms of generating uniform concave portions (honeycomb pits) in nitric acid alternating current electrolysis described later. It is preferably 0.10% by mass or less.
Preference is given to Si: 0.07 to 0.09 mass%, Fe: 0.20 to 0.29 mass%, Mn: 0.01 mass% or less, Mg: 0.01 mass% or less, Cr: 0.0. It is an aluminum plate which is 01 mass% or less, Zn: 0.01 mass% or less, Ti: 0.02 mass% or less, and Al: 99.4 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. As for 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. When the temperature is less than 1 ° C., many 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. As for the intermediate annealing conditions and the cold rolling conditions 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.
As for the strength of the aluminum plate, it is preferable that the 0.2% proof stress is 120 MPa or more in order to obtain the stiffness required for a lithographic printing plate support. Moreover, 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.
Further, the aluminum plate, tensile strength ^{160 ± 15N / mm 2, 0.2} % proof stress 140 ± 15 MPa, elongation as specified in JIS Z2241 and Z2201 is more preferably 1-10%.

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

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

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

The aluminum plate used in the present invention may be an aluminum plate having a concavo-convex pattern formed by transferring a concavo-convex pattern in advance, or may be formed by transferring a concavo-convex pattern to the aluminum plate. Although the process of forming unevenness by rolling is not limited, it is preferable to perform rolling using a rolling roll. The aluminum plate as shown above can be used by forming irregularities by lamination 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 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 easily adjust the amount of dampening water on the printing press while reducing energy consumed in subsequent alkali etching treatment and roughening treatment. Thus, a uniform concavo-convex shape can be easily obtained, and a lithographic printing plate precursor excellent in sensitivity, stain resistance and printing durability can be obtained.

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 of the rolling roll is pressed against the aluminum plate to transfer the uneven shape, and the aluminum plate A method of forming a concavo-convex pattern on the surface is preferable. 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 easily adjust the amount of dampening water on the printing press while reducing energy consumed in subsequent electrochemical roughening treatment. it can.

  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 the rolling reduction is preferably 3 to 8%.

In the present invention, a method of spraying predetermined alumina particles is used as a method of obtaining a transfer roll having irregularities on the surface, which is used for transferring irregularities, and among these, an air blast method is preferred.
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. When the thickness is within the above range, a sufficiently large surface roughness can be obtained as a transfer roll, and thus the surface roughness of an aluminum plate provided with irregularities using the transfer roll is sufficiently large. 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 polish 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, 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 preferable composition of the 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, are 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.

It is preferable that the transfer roll on which the unevenness is formed by the air blast method is 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. The 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 3 to 15 μm, and more preferably 5 to 10 μm. If it is in the above range, the plating peeling is difficult to peel off from the boundary between the roll surface substrate and the plating film, and 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.

  For example, JP-A-60-36195, JP-A-2002-251005, JP-A-60-203495, JP-A-55-74898, and JP-A-62-2 You may use the method described in each gazette of 111792.

It is preferable that the aluminum plate on which the concavo-convex pattern is formed using a rolling roll having concavo-convex on the surface has a structure having concavo-convex of 10 to 100 μm pitch on the surface.
In this case, the arithmetic average roughness (Ra) is preferably 0.4 to 1.5 [mu] m, and more preferably 0.4 to 0.8 [mu] m. Rmax is preferably 1 to 6 [mu] m, and more preferably 2 to 5 [mu] m. Further, RSm is preferably 5 to 150 [mu] m, and more preferably 10 to 100 [mu] m.
The number of concave portions on the surface is preferably ²⁰⁰ to 20000 / mm ² .

The aluminum plate having irregularities formed on the surface by transferring the irregular pattern 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 a defect 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 packing form 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 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, and more preferably 0.2 mm 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 method for producing a lithographic printing plate support of the present invention uses an aluminum plate having irregularities formed on its surface by transferring an irregular pattern,
(1) Electrochemical roughening treatment (hereinafter also referred to as “nitric acid AC electrolysis”) in nitric acid aqueous solution,
(2) Electrochemical roughening treatment (hereinafter also referred to as “hydrochloric acid AC electrolysis”) in aqueous hydrochloric acid,
(3) A method for producing a support for a lithographic printing plate, which is anodized.
In the method for producing a lithographic printing plate support of the present invention, various steps other than those described above may be included.
Further, before and after the above treatments (1) and (2), etching treatment in an aqueous alkaline solution (hereinafter also referred to as “alkali etching treatment”) and desmutting treatment in an acidic aqueous solution (hereinafter also referred to as “desmutting treatment”) May be performed.

  Among them, at least a first alkali etching treatment, a first desmutting treatment, a nitric acid alternating current electrolysis, a second alkaline etching treatment, a second desmutting treatment, a hydrochloric acid alternating current electrolysis, a third alkaline etching treatment, a third desmutting treatment and an anode. A method in which the oxidation treatment is performed in this order and a method in which a hydrophilization treatment is further performed after the anodizing treatment are preferable.

<Surface grain shape>
The rough surface of the support obtained by the production method of the present invention is formed by transferring a concavo-convex pattern to the concavo-convex of an aluminum plate having concavo-convex formed on the surface, and first pits having an average opening diameter of 0.5 to 5 μm. A second pit having an average opening diameter of 0.05 to 0.3 μm is superposed and then anodized. Furthermore, a hydrophilic treatment may be performed.
In the present invention, the first pit having an average opening diameter of 0.5 to 5 μm has a function of holding the image recording layer mainly by an anchor (throwing) effect and imparting printing durability. If the average opening diameter of the pits is less than 0.5 μm, the adhesion with the image recording layer provided on the upper layer may be lowered, and the printing durability of the planographic printing plate may be lowered. Further, when the average opening diameter of the pits exceeds 5 μm, the number of pit boundary portions serving as anchors is reduced, so that the printing durability may also be lowered.

  The second pit having an average opening diameter of 0.05 to 0.3 μm superimposed on the pit mainly serves to improve the stain resistance. When dampening water is supplied to the planographic printing plate during printing by combining the first pit with an average opening diameter of 0.5 to 5 μm and the second pit with an average opening diameter of 0.05 to 0.3 μm The water film is uniformly formed on the surface, and the occurrence of contamination on the non-image area can be suppressed. If the average opening diameter of the second pit is less than 0.05 μm, a large effect may not be obtained in forming a water film. If the average opening diameter of the pits exceeds 0.3 μm, the first pits of 0.5 to 5 μm are destroyed, and the effect of improving the printing durability by the pits described above may not be obtained.

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

<Mechanical roughening>
In the present invention, the mechanical surface roughening treatment using a brush and an abrasive may or may not be performed, but the mechanical surface roughening treatment using a brush and an abrasive is preferably not performed. The mechanical surface roughening treatment is preferably performed before the electrochemical surface roughening treatment. The surface area of the aluminum plate is increased by the mechanical roughening treatment.
First, prior to brush graining an aluminum plate, a degreasing treatment for removing rolling oil on the surface, for example, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution, or the like is performed as desired. However, when there is little adhesion of rolling oil, a degreasing process can be skipped.

  Subsequently, brush graining is performed while supplying the polishing slurry liquid to the surface of the aluminum plate using one type or at least two types of brushes having different bristle diameters. The mechanical surface roughening treatment is described in detail in JP-A-6-135175 and JP-B-50-40047. As the brush roller, brush rollers having different bristle diameters may be combined as described in JP-A-6-135175.

<First alkali etching treatment>
The alkali etching treatment is a treatment for dissolving the surface layer by bringing the above-described aluminum plate into contact with an alkali solution.

The first alkaline etching treatment performed before nitric acid alternating current electrolysis forms uniform recesses by nitric acid alternating current electrolysis, and removes rolling oil, dirt, natural oxide film, etc. on the surface of the aluminum plate (rolled aluminum). It is done for the purpose.
In the first alkali etching treatment, the etching amount is preferably 0.1 g / m ² or more, more preferably 0.5 g / m ² or more, and further preferably 1 g / m ² or more. Further, it is preferably 10 g / m ² or less, more preferably 8 g / m ² or less, further preferably 5 g / m ² or less, and further preferably 3 g / m ² or less. If the etching amount is too small, uniform pits cannot be generated in nitric acid alternating current electrolysis and unevenness may occur. On the other hand, when there is too much etching amount, the usage-amount of alkaline aqueous solution will increase and it will become economically disadvantageous.

  Examples of the alkali used in the alkaline solution include caustic alkali and alkali metal salts. Specifically, examples of caustic alkali include caustic soda and caustic potash. Examples of alkali metal salts include alkali metal silicates such as sodium silicate, 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, tribasic sodium phosphate, tertiary 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 alkali etching treatment, the concentration of the alkaline solution is preferably 30 g / L or more, more preferably 300 g / L or more, and preferably 500 g / L or less, 450 g / L. The following is more preferable.
The alkaline solution preferably contains aluminum ions. The aluminum ion concentration is preferably 1 g / L or more, more preferably 50 g / L or more, and preferably 200 g / L or less, more preferably 150 g / L or less. Such an alkaline solution can be prepared using, for example, water, a 48 mass% sodium hydroxide aqueous solution, and sodium aluminate.

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

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

When the aluminum plate is continuously etched, the aluminum ion concentration in the alkaline solution increases and the etching amount of the aluminum plate varies. Therefore, the composition management of the etching solution is preferably performed as follows.
That is, a matrix of conductivity, specific gravity, and temperature, or a matrix of conductivity, ultrasonic propagation velocity, and temperature corresponding to the matrix of caustic soda concentration and aluminum ion concentration is prepared in advance, and the conductivity and specific gravity are prepared. The liquid composition is measured according to the temperature and temperature, or the electrical conductivity, the ultrasonic wave propagation speed, and the temperature, and caustic soda and water are added so that the control target value of the liquid composition is reached. Then, the amount of the etching solution increased by adding caustic soda and water is overflowed from the circulation tank, thereby keeping the amount of the solution constant. As caustic soda to be added, 40 to 60% by mass for industrial use can be used.
As the conductivity meter and the specific gravity meter, it is preferable to use those that are temperature-compensated. As the 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-falling 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 fall 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 where 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 alkali etching treatment, pickling (first desmutting treatment) is preferably performed to remove dirt (smut) remaining on the surface. The desmut treatment is performed by bringing an aluminum plate into contact with an acidic solution.

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

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

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

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

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

Examples of the method of bringing the aluminum plate into contact with the acidic solution include, for example, a method of passing the aluminum plate through a bath containing the acidic solution, a method of immersing the aluminum plate in a bath containing the acidic solution, and an acidic solution containing aluminum. The method of spraying on the surface of a board is mentioned.
Among these, a method in which an acidic solution is sprayed on the surface of an aluminum plate is preferable. Specifically, a method of spraying 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 desmutting process is completed, it is preferable to drain the liquid with a nip roller, and further perform the water washing process for 1 to 10 seconds, and then drain the liquid with a nip roller.
The water washing treatment is the same as the water washing treatment after the alkali etching treatment. However, the amount of liquid per spray tip is preferably 1 to 20 L / min.

  In the first desmut process, when using the overflow waste liquid of the electrolyte used in the subsequent nitric acid alternating current electrolysis as the desmut process liquid, after the desmut process, the nip roller is not drained and washed with water. In order to prevent the surface from drying, it is preferable to handle the aluminum plate until the nitric acid alternating current electrolysis step while spraying a desmut treatment liquid as necessary.

<Nitric acid AC electrolysis>
Nitric acid alternating current electrolysis is an electrochemical surface roughening treatment using alternating current in an aqueous solution containing nitric acid. A suitable concavo-convex structure can be formed on the surface of the aluminum plate by nitric acid alternating current electrolysis. When the aluminum plate contains a relatively large amount of Cu, a relatively large and uniform recess is formed in nitric acid alternating current electrolysis. As a result, the lithographic printing plate using the obtained lithographic printing plate support has excellent printing durability.

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

Various electrolyzers and power sources have been proposed, including US Pat. No. 4,203,637, JP-A-56-123400, JP-A-57-59770, JP-A-53-12738, JP 53-32821, JP 53-32222, JP 53-32823, JP 55-122896, JP 55-13284, JP 62-127500, JP Those described in JP-A-1-52100, JP-A-1-52098, JP-A-60-67700, JP-A-1-230800, JP-A-3-257199 and the like can be used.
Further, 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- Nos. 149135 and 54-146234 can be used.

An aqueous solution containing nitric acid is added to an aqueous solution of nitric acid having a concentration of 1 to 100 g / L in a range from 1 g / L to saturation of at least one of nitric acid compounds having nitrate ions such as aluminum nitrate, sodium nitrate, and ammonium nitrate. Can be used. Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, a silica, may melt | dissolve in the aqueous solution containing nitric acid.
Specifically, a solution prepared by dissolving aluminum nitrate in an aqueous nitric acid solution having a nitric acid concentration of 5 to 15 g / L and adjusting the aluminum ion concentration to 3 to 7 g / L is preferable.

When the electrolytic roughening treatment is continuously performed on the aluminum plate, the aluminum ion concentration in the alkaline solution increases, and the uneven shape of the aluminum plate formed by nitric acid AC electrolysis varies. Therefore, it is preferable to manage the composition of the nitric acid electrolyte as follows.
That is, a matrix of conductivity, specific gravity, and temperature, or a matrix of conductivity, ultrasonic propagation velocity, and temperature, corresponding to the matrix of nitric acid concentration and aluminum ion concentration, is prepared in advance, and the conductivity and specific gravity are prepared. And the temperature, or the liquid composition is measured according to the electric conductivity, the ultrasonic wave propagation speed, and the temperature, and nitric acid and water are added so that the control target value of the liquid composition is reached. Then, the electrolytic solution increased by adding nitric acid and water is overflowed from the circulation tank, so that the liquid amount is kept constant. As nitric acid to be added, 30 to 70% by mass of industrial grade can be used.
As the conductivity meter and the specific gravity meter, it is preferable to use those that are temperature-compensated. As the hydrometer, it is preferable to use a differential pressure type.
Samples taken from the electrolyte for use in measuring the liquid composition are used for measurement after being controlled at a constant temperature (eg, 40 ± 0.5 ° C.) using a heat exchanger different from the electrolyte. However, it is preferable in that the accuracy of measurement is increased.

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

  The temperature of the aqueous solution containing nitric acid is preferably 30 ° C or higher, and preferably 55 ° 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, but a rectangular wave or a trapezoidal wave is preferable, and a trapezoidal wave is particularly preferable. A trapezoidal wave means what was shown in FIG. In this trapezoidal wave, the time (TP) until the current reaches a peak from zero is preferably 0.5 to 3 msec. When TP exceeds 3 msec, especially when an aqueous solution containing nitric acid is used, it becomes susceptible to the influence of trace components in the electrolytic solution typified by ammonium ions and the like that spontaneously increase by electrolytic treatment, and uniform graining. Is difficult to be performed. As a result, the stain resistance tends to decrease when a lithographic printing plate is obtained.

A duty ratio of trapezoidal wave alternating current of 1: 2 to 2: 1 can be used. However, as described in Japanese Patent Laid-Open No. 5-195300, in an indirect power feeding method in which no conductor roll is used for aluminum, A duty ratio of 1: 1 is preferable.
A trapezoidal AC frequency of 0.1 to 120 Hz can be used, but 50 to 70 Hz is preferable in terms of equipment. If it is lower than 50 Hz, the carbon electrode of the main electrode is likely to be dissolved, and if it is higher than 70 Hz, it is likely to be affected by the inductance component on the power supply circuit and the power supply cost is increased.

  One or more AC power supplies can be connected to the electrolytic cell. As shown in FIG. 3, 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. 3, 11 is an aluminum plate, 12 is a radial drum roller, 13a and 13b are main poles, 14 is an electrolytic treatment liquid, 15 is an electrolytic solution 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. An anodic reaction that acts on the aluminum plate facing the main electrode by diverting a part of the current value as a direct current to an auxiliary anode provided in a tank separate from the two main electrodes via a rectifier or switching element It is possible to control the ratio between the current value for the current and the current value for the cathode reaction. On the aluminum plate facing the main electrode, the ratio of the amount of electricity involved in the anodic reaction and the cathodic reaction (the amount of electricity at the time of cathode / the amount of electricity at the time of anode) is preferably 0.3 to 0.95.

  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 to the traveling direction of the aluminum web or may be a counter.

Pits having an average opening diameter of 0.5 to 5 μm can be formed by nitric acid AC electrolysis. However, when the amount of electricity is relatively large, the electrolytic reaction is concentrated, and honeycomb pits exceeding 5 μm are also generated.
To obtain such a grain, the total amount of electricity furnished to anode reaction on the aluminum plate up until the electrolysis reaction is completed is preferably at 150C / dm ² or more, at 170C / dm ² or more more preferably, but preferably not 400C / dm ² or less, more preferably 350C / dm ² or less. The current density at this time is preferably ²⁰ to 100 A / dm ² at the peak value of the current.

After the nitric acid AC electrolysis 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.

If the following pre-electrolysis is performed before the nitric acid alternating current electrolysis, deep concave portions are not formed in the nitric acid alternating current electrolysis.
Pre-electrolysis is a step of forming the starting point of pit formation during nitric acid AC electrolysis. By performing slight electrolysis using hydrochloric acid that is hardly affected by the material of the aluminum plate and has very high corrosive properties, pits can be formed uniformly on the surface.
In the pre-electrolysis, the hydrochloric acid concentration is preferably 1 to 15 g / L, and the amount of electricity at the anode is preferably 30 to 70 C / m ² .
After pre-electrolysis, it is preferable to perform alkali etching to remove smut. The amount of aluminum dissolved in the alkali etching is preferably 0.2 to 0.6 g / m ² .

<Second alkali etching treatment>
The second alkali etching process performed between nitric acid alternating current electrolysis and hydrochloric acid alternating current electrolysis involves dissolving the smut generated by nitric acid alternating current electrolysis and dissolving the edge portion of the pit formed by nitric acid alternating current electrolysis. Done as a purpose. Since the second alkali etching process is basically the same as the first alkali etching process, only different points will be described below.

In the second alkali etching treatment, the etching amount is preferably at 0.05 g / m ² or more, more preferably 0.1 g / m ² or more, and it is at 4g / m ² or less Preferably, it is 3.5 g / m ² or less. If the etching amount is too small, the edge portion of the pit generated by nitric acid AC electrolysis is not smooth in the non-image portion of the lithographic printing plate, and the ink is likely to get caught, so that the stain resistance may be deteriorated. On the other hand, if the etching amount is too large, the unevenness generated by nitric acid AC electrolysis is reduced, so that the printing durability may be deteriorated.

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

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

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

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

<Hydrochloric acid alternating current electrolysis>
Hydrochloric acid alternating current electrolysis is an electrochemical surface roughening treatment using alternating current in an aqueous solution containing hydrochloric acid. A suitable uneven structure can be formed on the surface of the aluminum plate by hydrochloric acid alternating current electrolysis.

  Hydrochloric acid AC electrolysis can be carried out in substantially the same manner as the above-described nitric acid AC electrolysis except that the electrolytic solution is different. Only different points will be described below.

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

  The temperature of the aqueous solution containing hydrochloric acid is preferably 25 ° C. or higher, more preferably 30 ° C. or higher, more preferably 55 ° C. or lower, and even more preferably 40 ° C. or lower.

Since hydrochloric acid itself has a strong ability to dissolve aluminum, it is possible to form fine irregularities on the surface with only slight electrolysis. These fine irregularities have an average opening diameter of 0.01 to 0.2 μm and are uniformly generated on the entire surface of the aluminum plate. In order to obtain such a grain, the total amount of electricity involved in the anode reaction of the aluminum plate at the time when the electrolytic reaction is completed is preferably 10 C / dm ² or more, and more preferably 50 C / dm ² or more. Is more preferably 100 C / dm ² or less, and more preferably 80 C / dm ² or less. The current density at this time is preferably ²⁰ to 100 A / dm ² at the peak value of the current.

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

<Third alkali etching treatment>
The third alkali etching treatment performed after the hydrochloric acid alternating current electrolysis is performed for the purpose of dissolving the smut generated by the hydrochloric acid alternating current electrolysis and dissolving the edge portion of the pit formed by the hydrochloric acid alternating current electrolysis. Since the third alkali etching process is basically the same as the first alkali etching process, only different points will be described below.

In the third alkali etching treatment, the etching amount is preferably at 0.05 g / m ² or more, more preferably 0.1 g / m ² or more, is 0.3 g / m ² or less Of 0.25 g / m ² or less is more preferable. If the etching amount is too small, the edge portion of the pit generated by hydrochloric acid alternating current electrolysis is not smooth in the non-image portion of the lithographic printing plate, and the ink tends to get caught, so that the stain resistance may be deteriorated. On the other hand, if the etching amount is too large, the unevenness generated by nitric acid alternating current electrolysis and hydrochloric acid alternating current electrolysis becomes small, so the printing durability may deteriorate.

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

  In the third alkali etching treatment, the temperature of the alkali solution is preferably 25 ° C or higher, more preferably 30 ° C or higher, and preferably 60 ° C or lower, and 50 ° C or lower. Is more preferable.

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

<Third desmut treatment>
After the third alkali etching treatment, it is preferable to perform pickling (third desmutting treatment) in order to remove dirt (smut) remaining on the surface. Since the third desmut process is basically the same as the first desmut process, only the differences will be described below.
In the third desmutting process, the same type of liquid as that used in the subsequent anodizing process (for example, sulfuric acid) is used, thereby omitting the water washing step between the third desmutting process and the anodizing process. It is preferable in that it can be performed.
In the third desmutting treatment, it is preferable to use an acidic solution containing 5-400 g / L acid and 0.5-8 g / L aluminum ions.
In the third desmutting treatment, the treatment time is preferably 1 second or longer, more preferably 4 seconds or longer, more preferably 60 seconds or shorter, and more preferably 15 seconds or shorter. .
In the third desmut process, when the same type of electrolyte as that used in the subsequent anodic oxidation 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.

<Anodizing treatment>
The aluminum plate treated as described above is further subjected to 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 2nd, 3rd component may be added. Examples of the second and third components herein include metal ions such as Na, K, Mg, Li, Ca, Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn; Cation such as ammonium ion; anion such as nitrate ion, carbonate ion, chloride ion, phosphate ion, fluoride ion, sulfite ion, titanate ion, silicate ion, borate ion, etc., 0 to 10,000 ppm It may be contained at a concentration of about.

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

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

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

  The composition management of the electrolytic solution is conducted using the same method as in the case of the above-described nitric acid alternating current electrolysis, etc., and the conductivity, specific gravity and temperature, or the conductivity and ultrasonic wave corresponding to the matrix of sulfuric acid concentration and aluminum ion concentration. It is preferable to control by the propagation speed and temperature.

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

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 the anodizing treatment, so that current is concentrated on a part of the aluminum plate and so-called “burning” (part where the film becomes thicker than the surroundings) does not occur. It is preferable to increase the current density to 30 to 50 A / dm ² or higher as the anodic oxidation process proceeds with a current flowing at a low current density of 5 to 10 A / m ² .
Specifically, it is preferable that the current distribution of the DC power supply is set so that the current of the downstream DC power supply is equal to or greater than the current of the upstream DC power supply. By using such current distribution, so-called burning is less likely to occur, and as a result, high-speed anodization can be performed.

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

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

As electrolysis apparatuses used for anodizing treatment, those described in JP-A-48-26638, JP-A-47-18739, JP-B-58-24517, JP-A-2001-11698, etc. Can be used.
Among these, the apparatus shown in FIG. 4 is preferably used. FIG. 4 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. 4, in order to energize the aluminum plate 416 via the electrolytic solution, a power feeding tank 412 is provided on the upstream side in the traveling direction of the aluminum plate 416, and an anodizing treatment tank 414 is provided on the downstream side. It is installed. The aluminum plate 416 is conveyed by the pass rollers 422 and 428 as indicated by arrows in FIG. In the feed tank 412 into which the aluminum plate 416 is first introduced, an anode 420 connected to the positive electrode of the DC power supply 434 is installed, and the aluminum plate 416 serves as a cathode. Therefore, a cathode reaction occurs in the aluminum plate 416.

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

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

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

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

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

  Further, the anodizing apparatus shown in FIG. 5 is obtained by connecting the two anodizing apparatuses shown in FIG. 4 described above in series.

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

<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 fluorinated zirconate 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 Phosphate-modified starch, diamine compounds described in JP-A-63-056498, amino acid inorganic or organic acids described in JP-A-63-130391, JP-A-63-145092 Organic phosphonic acids containing carboxy group or hydroxy group, compounds having amino group and 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, and 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 Group 4 (Group IVA) metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium 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 the hydrophilic compound used in this method include compounds having at least one selected from the group consisting of -NH2 group, -COOH group and sulfo group.

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

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

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

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

Examples of the alkali-soluble polymer compound include a resin containing an acidic group in the molecule and a mixture of two or more thereof. In particular, a phenolic hydroxy group, a sulfonamide group (-SO2 NH-R (wherein R represents a hydrocarbon group)), an active imino group (-SO2 NHCOR, -SO2 NHSO2 R, -CONHSO2 R (each formula Among them, R has the same meaning as described above.))) A resin having an acidic group is preferable from the viewpoint of solubility in an alkali developer.
In particular, a resin having a phenolic hydroxy group is preferable in that it has excellent image-forming properties when exposed to light such as an infrared laser, and examples thereof include phenol-formaldehyde resins, m-cresol-formaldehyde resins, p-cresol-formaldehyde resins, m- / p-mixed cresol-formaldehyde resin, phenol / cresol (any of m-, p- and m- / p-mixed) mixed-formaldehyde resin (phenol-cresol-formaldehyde co-condensation resin) and other novolak resins Are preferable.
Furthermore, the polymer compound described in JP-A No. 2001-305722 (particularly [0023] to [0042]), and the repetition represented by the general formula (1) described in JP-A No. 2001-215893 Preferred examples also include polymer compounds containing units, and polymer compounds described in JP-A No. 2002-311570 (particularly [0107]).

  Preferable examples of the photothermal conversion substance include pigments or dyes having a light absorption region in the infrared region having a wavelength of 700 to 1200 nm 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 may contain a dissolution inhibitor. As the dissolution inhibitor, for example, dissolution inhibitors described in JP-A-2001-305722, [0053] to [0055] are preferably exemplified.
In addition, in the thermal positive type photosensitive composition, as a additive, a sensitivity modifier, a printing agent for obtaining a visible image immediately after heating by exposure, a compound such as a dye as an image colorant, a coating property In addition, it is preferable to include a surfactant for improving the processing stability. For these, compounds described in JP-A-2001-305722, [0056] to [0060] are preferable.
The photosensitive composition described in detail in Japanese Patent Application Laid-Open No. 2001-305722 is also preferably used in other respects.

Further, the thermal positive type image recording layer is not limited to a single layer but may have a two-layer structure.
As an image recording layer having a two-layer structure (multilayer image recording layer), a lower layer (hereinafter referred to as “A layer”) having excellent printing durability and solvent resistance is provided on the side close to the support, and a positive layer is provided thereon. A type provided with a layer having excellent image formability (hereinafter referred to as “B layer”) is preferable. This type has high sensitivity and can realize a wide development latitude. The B layer generally contains a photothermal conversion substance. Preferred examples of the photothermal conversion substance include the dyes described above.
As the resin used in the A layer, a polymer having a monomer having a sulfonamide group, an active imino group, a phenolic hydroxy group or the like as a copolymerization component is preferably used because it has excellent printing durability and solvent resistance. . As the resin used for the B layer, an alkaline aqueous solution-soluble resin having a phenolic hydroxy group is preferably exemplified.
In addition to the resin, the composition used for the A layer and the B layer can contain various additives as necessary. Specifically, various additives as described in JP-A-2002-3233769, [0062] to [0085] are preferably used. Further, the additives described in [0053] to [0060] of JP-A-2001-305722 described above are also preferably used.
About each component which comprises A layer and B layer, and its content, it is preferable to make it describe in Unexamined-Japanese-Patent No. 11-218914.

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

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

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

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

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

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

<Acid cross-linked layer>
Further, as one of the thermal negative type image recording layers, an acid cross-linked image recording layer (acid cross-linked layer) is also preferably exemplified. The acid 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 kinds of photopolymerization initiators can be appropriately selected depending on the wavelength of the light source to be used. For example, an initiation system described in JP-A-2001-22079, [0021] to [0023] is preferably exemplified.
The polymer binder not only functions as a film forming agent for the photopolymerization type photosensitive composition, but is soluble or swellable in alkaline water because 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 oxygen polymerization inhibiting action. 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 them, preferred is a photosensitive composition containing a diazo resin and an alkali-soluble or swellable polymer compound (binder).
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, a multi-component copolymer of monomers such as 2-hydroxyethyl (meth) acrylate, (meth) acrylonitrile, (meth) acrylic acid as described in JP-A-50-118802, Examples thereof include multi-component copolymers composed of alkyl acrylate, (meth) acrylonitrile and unsaturated carboxylic acid as described in JP-A-56-4144.

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

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

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

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

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

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

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

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

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

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

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

<Back coat>
In this way, the back surface 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 any of thermal positive type, thermal negative type, conventional negative type, conventional positive type, and photopolymer type, after exposure, it is 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.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
1-1. Preparation of lithographic printing plate support (Examples 1 to 23 and Comparative Example 1)
A molten metal is prepared using an aluminum alloy having the composition shown in Table 1 (the balance is aluminum and inevitable impurities), and after performing the molten metal treatment and filtration, an ingot having a thickness of 500 mm and a width of 1200 mm is formed by a DC casting method. did. 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 finished by cold rolling to 0.3 mm in thickness and 1060 mm in width, and obtained the aluminum plate.

<Production of rolling roll>
C: 1.52 mass%, Si: 0.31 mass%, Mn: 0.41 mass%, P: 0.028 mass%, S: 0.002 mass%, Cr: 11.6 mass%, Mo: 1.05% by mass, Cu: 0.12% by mass, V: 0.27% by mass, balance: iron and unavoidable impurities SKD11 steel are hardened and tempered so that the hardness Hs becomes 82 The surface of the roll having a smooth surface with an average surface roughness Ra of 0.1 μm was subjected to a surface roughening treatment by performing an air blasting process twice. In the air blast method, alumina particles having an average particle size of 90 μm were used as the grid material, and the grid material was sprayed so that the angle with the spray surface was 90 °.
Then, the surface of the roll was polished with abrasive paper until the height variation of the convex portion on the roll surface was within 1 μm.
Then, hard chrome plating was performed so that the thickness was 8 μm, and a rolling roll having an Ra of 0.65 μm was obtained.

In the final cold rolling step in the production process of the aluminum rolled plate, the aluminum plate was subjected to rolling (transfer) to generate irregularities by using the rolling roll produced above. The surface roughness after rolling was the following value.
Ra = 0.5 μm, Rmax = 3.0 μm, Sm = 100 μm, Δa = 3.5 μm, and the measurement method is as follows.
(1) Average roughness Two-dimensional roughness measurement is performed with a stylus type roughness meter (SUFCOM 575, manufactured by Tokyo Seimitsu Co., Ltd.), the arithmetic average roughness Ra defined in ISO 4287 is measured five times, and the average value is calculated. Average roughness. The maximum height Rmax (Ry) for the reference length, the average interval of irregularities (average value in the reference length) Sm, and the average slope gradient Δa were also measured in the same manner.

<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

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

<1> Etching Treatment in Alkaline Aqueous Solution An aluminum plate was etched by spraying an aluminum plate containing NaOH, 27 wt%, and aluminum ions 6.5 wt% at 60 ° C. from a spray tube. The amount of dissolution of the aluminum plate on the surface to be electrochemically roughened in a later step was 1.5 g / ·. Thereafter, the liquid was drained with a nip roller, washed with water, and further drained with a nip roller.

<2> Desmutting in acidic aqueous solution Next, desmutting was performed.
The waste liquid of nitric acid used for electrochemical roughening in the next step was used. The liquid temperature was 35 ° C. The desmutting solution was sprayed and sprayed for 5 seconds. Thereafter, the liquid was drained with a nip roller.

<3> Electrochemical roughening treatment in aqueous nitric acid solution An electrolytic solution prepared by adding aluminum nitrate to an aqueous solution with a liquid temperature of 35 ° C and a nitric acid concentration of 10 g / l to adjust the aluminum ion concentration to 4.5 g / l. Using.
An electrochemical surface roughening treatment was performed using a power source for generating an alternating current shown in FIG. The frequency of the alternating current was 60 Hz, and the time Tp from the current zero to the peak was 1.2 msec. The duty (ta / T) of alternating current was 0.5.
The current density at the time of the alternating current peak was 60 A / dm ² during the anode reaction of the aluminum plate. The ratio of the total amount of electricity during the anode reaction and the total amount of electricity during the cathode reaction of the aluminum plate was 0.95. The amount of electricity applied to the aluminum plate was 195 C / dm ^{2 as} the total amount of electricity during the anode reaction of the aluminum plate.
Two electrolytic treatment tanks of the radial type shown in FIG. 3 were used.
The relative speed of the aluminum plate and the electrolytic solution was 1.5 m / sec (1-2 m / sec) on average in the electrolytic cell. Thereafter, the liquid was drained with a nip roller, washed with water, and further drained with a nip roller.

<4> Etching treatment in alkaline aqueous solution An aluminum plate is treated with NaOH, 27 wt%, aluminum ion 5.5 wt%, 65 ° C sprayed from a spray tube and treated for 8 seconds to etch the aluminum plate. It was. The amount of dissolution of the aluminum plate on the surface to be electrochemically roughened in the subsequent step was 3 g / m ² . Thereafter, the liquid was drained with a nip roller, washed with water, and further drained with a nip roller.

<5> Desmutting in acidic aqueous solution Next, desmutting was performed.
Desmutting treatment was performed for 10 seconds at a liquid temperature of 35 ° C. using the waste liquid (1.5 g / l aluminum ion dissolved in 300 g / l sulfuric acid aqueous solution) generated in the anodizing process. Thereafter, the liquid was drained with a nip roller, washed with water, and further drained with a nip roller.

<6> Electrochemical roughening treatment in hydrochloric acid aqueous solution Use an electrolytic solution in which the aluminum ion concentration is adjusted to 5 g / l by adding aluminum chloride to an aqueous solution with a liquid temperature of 35 ° C and hydrochloric acid concentration of 5 g / l. It was.
An electrochemical surface roughening treatment was performed using a power source that generates trapezoidal alternating current shown in FIG. The frequency of the alternating current was 60 Hz, and the time Tp until the peak of the alternating current reached zero was 0.8 msec. The duty (ta / T) of alternating current was 0.5.
The current density was 50 A / dm ² during the anode reaction of the aluminum plate at the peak of alternating current, and the ratio of the total amount of electricity during the anode reaction of the aluminum plate and the total amount of electricity during the cathode reaction was 0.95. The amount of electricity applied to the aluminum plate was 63 C / dm ^{2 as} the total amount of electricity during the anode reaction of the aluminum plate.
As the electrolytic treatment tank, one radial type tank shown in FIG. 3 was used.
The relative speed of the aluminum plate and the electrolytic solution was 1.5 m / sec on average in the electrolytic cell. Thereafter, the liquid was drained with a nip roller, washed with water, and further drained with a nip roller.

<7> Etching treatment in alkaline aqueous solution An aluminum plate is dissolved in NaOH, 5 wt%, aluminum ions, 0.5 wt% aqueous solution, 35 ° C from a spray tube to dissolve the aluminum plate in an amount of 0.1 g / m ² . Etching was performed.
Thereafter, the liquid was drained with a nip roller, washed with water, and further drained with a nip roller.

<8> Desmut treatment in acidic aqueous solution Next, desmut treatment was performed. The acidic aqueous solution used for the desmut treatment is the waste solution generated in the next anodizing treatment step (1.5 g / l aluminum ion dissolved in 300 g / l sulfuric acid aqueous solution) and desmutted for 5 seconds at a liquid temperature of 60 ° C. It was. Thereafter, the liquid was drained with a nip roller.

<9> Anodizing treatment This plate was anodized using the anodizing apparatus shown in FIG. 4 under the following conditions.
The current density applied to the aluminum plate in the electrolytic treatment tank using an electrolytic solution, 33 ° C., in which aluminum sulfate is added to 170 g / l of sulfuric acid to make the aluminum ion concentration 5 g / l, is during the anodic reaction of the aluminum plate. A direct current anodic oxide coating of 2.4 g / m ² was provided under conditions such that the average current density was 10 A / dm ² . Thereafter, the liquid was drained with a nip roller, washed with water, and further drained with a nip roller.

<10> Hydrophilization treatment Hydrophilic treatment was performed by immersing in an aqueous solution containing 2.5% sodium silicate at 20 ° C. for 10 seconds. Thereafter, the liquid was drained with a nip roller, washed with water, and further drained with a nip roller. The amount of Si on the surface of the aluminum plate was measured with a fluorescent X-ray analyzer. The amount of Si on the aluminum surface was 3.5 mg / m ² .
Then, 90 degreeC wind was blown for 10 seconds and it dried.

(Examples 24-26)
Using an aluminum alloy having the composition shown in Table 1, aluminum plates were obtained in the same manner as in Examples 1 to 23. However, in the cold rolling, instead of the two air blasting methods, the same as the production of the rolling roll described above, except that the shot blasting method using steel particles having an average particle size of 200 μm as a grid material was performed twice. Unevenness was formed on the surface by transferring the unevenness pattern using a rolling roll different from Examples 1 to 23 obtained by the method. The surface roughness Ra of the aluminum plate was 0.45 μm in all cases. Using this aluminum plate, a lithographic printing plate support was obtained by the following method.

<Surface treatment>
The surface treatment was performed in the same manner as the surface treatment of <1> to <10> in Examples 1 to 23 except for the portions described below among the above treatments <1> to <10>.
<1> Etching treatment in alkaline aqueous solution Etching treatment was carried out in the same manner except that the caustic soda concentration was 370 g / L and the aluminum ion concentration was 100 g / L. Table 3 shows the etching amount of the surface subjected to the electrochemical roughening after the aluminum plate.
Thereafter, the liquid was drained with a nip roller, and further, a water washing treatment described later was performed, and then the liquid was drained with a nip roller. The water washing treatment is carried out by washing with water using an apparatus for washing with a free-falling curtain-like liquid film, and further with water for 5 seconds using a spray tube having a structure in which 30 spray nozzles are arranged in a line at a pitch of 50 mm. went.

<2> Desmutting treatment The same treatment as in Examples 1 to 23 was performed. Then, without carrying out liquid removal with a nip roller, it conveyed in the state which nitric acid aqueous solution adhered to the aluminum plate. The conveyance time was 25 seconds.

<3> Electrochemical roughening treatment using alternating current in aqueous nitric acid The same treatment was performed except that the amount of electricity was set to 200 C / dm ^{2 as} the total amount of electricity when the aluminum plate was anode.

<4> Etching treatment in aqueous alkali solution An etching treatment was carried out by spraying an aqueous solution having a caustic soda concentration of 370 g / L and an aluminum ion concentration of 100 g / L from the spray tube for 7 seconds. The etching amount of the aluminum plate subjected to the electrochemical surface roughening treatment was 3 g / m ² .
Thereafter, the liquid was drained with a nip roller, and further, a water washing treatment described later was performed, and then the liquid was drained with a nip roller. Rinse with water using a free-fall curtain-like liquid film, and then wash with water for 5 seconds using a spray tube with the same structure as that used in the water washing process of <1> above. It went by.

<5> Desmut treatment An aqueous solution (liquid temperature 35 ° C.) in which aluminum nitrate was dissolved in 300 g / L nitric acid aqueous solution to make the aluminum ion concentration 2 g / L was sprayed from a spray tube for 10 seconds to perform desmut treatment.
Thereafter, the liquid was drained with a nip roller, and further, after being washed with a spray tube having the same structure as that used in the water washing process of <1> above, the liquid was drained with a nip roller.

<6> Electrochemical roughening treatment using alternating current in aqueous hydrochloric acid The same treatment as in Examples 1 to 23 was performed.

<7> Etching treatment in alkaline aqueous solution The same treatment as in Examples 1 to 23 was performed.
Thereafter, the liquid was drained with a nip roller, and further, a water washing treatment described later was performed, and then the liquid was drained with a nip roller. The water washing treatment was performed by washing with water using an apparatus for washing with a free-fall curtain-like liquid film, and further with water using a spray tube having φ3 mm holes at a pitch of 20 mm for 5 seconds.

<8> Desmut treatment An aqueous solution (liquid temperature 35 ° C.) having a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L was sprayed from a spray tube for 5 seconds to perform desmut treatment. As the aqueous solution, the waste liquid of the <9> anodizing treatment step described later was used.
Thereafter, the liquid was drained with a nip roller, but no water washing treatment was performed.

<9> Anodizing treatment Anodizing treatment was performed using the anodizing treatment apparatus shown in FIG.
As the electrolytic solution, an electrolytic solution (temperature 33 ° C.) in which aluminum sulfate was dissolved in a 170 g / L sulfuric acid aqueous solution to make the aluminum ion concentration 5 g / L was used. The anodizing treatment was performed so that the average current density during the anodic reaction of the aluminum plate was 15 A / dm ² , and the final oxide film amount was 2.4 g / m ² .
The anodizing apparatus shown in FIG. 5 is obtained by connecting the two anodizing apparatuses shown in FIG. 4 described above in series. However, the number of DC power supplies differs between the first tank and the second tank. In the anodizing apparatus, the currents of the DC power supplies A to H in the first tank and the DC power supplies I to L in the second tank are 31,000 A in total, and the current distribution and the electrolysis voltage are as shown in Table 2. Met. All electrodes connected to each DC power source had the same length. During the anodizing process, the total time for the aluminum plate to participate in the anodic reaction was 16 seconds.
Thereafter, the liquid was drained with a nip roller, and further, after being washed with a spray tube having the same structure as that used in the water washing process of <1> above, the liquid was drained with a nip roller.

<10> Hydrophilization treatment The aluminum plate was immersed in a 2.5% by weight aqueous solution of sodium silicate (liquid temperature 20 ° C.) for 10 seconds. The amount of Si on the surface of the aluminum plate measured with a fluorescent X-ray analyzer was 3.5 mg / m ² .
Thereafter, the liquid was drained with a nip roller, and further, after being washed with a spray tube having the same structure as that used in the water washing process of <1> above, the liquid was drained with a nip roller.
Furthermore, 90 degreeC wind was sprayed for 10 seconds, it was made to dry, and the support body for lithographic printing plates was obtained.

1-2. Observation of the surface of a lithographic printing plate support The surface of each lithographic printing plate support obtained above was subjected to a magnification of 50000 using a scanning electron microscope (JSM-5500, manufactured by JEOL Ltd., the same shall apply hereinafter). When observed at a magnification, fine irregularities with an average opening diameter of 0.1 μm were formed uniformly and densely.
Further, when observed at a magnification of 2000 using a scanning electron microscope, irregularities having an average opening diameter of 1 to 5 μm were uniformly formed on the surface of the lithographic printing plate support of Examples 1 to 26. On the other hand, the lithographic printing plate support of Comparative Example 1 had unevenness.
In addition, the fine unevenness | corrugation with an average opening diameter of 0.1 micrometer was superimposed and produced | generated on the unevenness | corrugation with an average opening diameter of 1-5 micrometers.
Furthermore, when the surface of each lithographic printing plate support obtained above was observed with the naked eye, none of the lithographic printing plate supports were excellent in surface quality because of no streak.

1-3. 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.

An undercoat solution having the following composition was applied onto a lithographic printing plate support 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

1-4. Evaluation of planographic printing plate precursor The printing durability and stain resistance 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 alkali developer having the following composition, the solution temperature was maintained at 30 ° C. and development was performed for 20 seconds to obtain a lithographic printing plate. All the lithographic printing plate precursors had good sensitivity.

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

The resulting lithographic printing plate was printed on a Lithrone printing machine manufactured by Komori Corporation using DIC-GEOS (N) ink made 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 3. The meanings of the symbols in Table 3 are as follows.
Evaluation A: Number of printed sheets 30,000 or more A-B: Number of printed sheets less than 30,000 sheets-10,000 or more B: Number of printed sheets less than 10,000

(2) Stain resistance Using a lithographic printing plate obtained in the same manner as in the evaluation of printing durability, a DIC-GEOS (s) red ink was applied using a Mitsubishi diamond F2 printer (Mitsubishi Heavy Industries, Ltd.). The blanket was stained and visually evaluated after 10,000 sheets were printed.
The results are shown in Table 3. The meanings of the symbols in Table 3 are as follows.
Evaluation A: Not dirty A-B: Almost not dirty B: Dirty but within acceptable range C: Clearly dirty

  As is clear from Table 3, all the lithographic printing plates using the lithographic printing plate support obtained by the method for producing a lithographic printing plate support of the present invention (Examples 1 to 26) had printing durability. Also excellent in dirt resistance.

また、実施例１〜２６で得られた平版印刷版用支持体を用いた平版印刷版は、比較例１で得られた平版印刷版用支持体を用いた平版印刷版と比べて、印刷機上における湿し水の量の調整が容易であった。

In addition, the lithographic printing plate using the lithographic printing plate support obtained in Examples 1 to 26 was compared with the lithographic printing plate using the lithographic printing plate support obtained in Comparative Example 1 as a printing machine. It was easy to adjust the amount of dampening water above.

It is typical sectional drawing of the apparatus which performs a water washing process with the free-fall curtain-like liquid film used for the water washing process in the manufacturing method of the support body for lithographic printing plates of this invention. It is a graph which shows an example of the alternating waveform current waveform figure 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 the alternating current in the manufacturing method of the support body for lithographic printing plates of this invention. It is the schematic of the anodizing apparatus used for the anodizing process in the manufacturing method of the support body for lithographic printing plates of this invention. It is the schematic of the other anodizing apparatus used for the anodizing process in the manufacturing method of the support body for lithographic printing plates of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aluminum plate 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 Free Apparatus for washing with water using falling curtain-like liquid film 102 Water 104 Water storage 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 port

Claims (7)

By transferring the uneven pattern, using an aluminum plate with irregularities on the surface,
(1) Electrochemical roughening treatment in nitric acid aqueous solution,
(2) Electrochemical roughening treatment in aqueous hydrochloric acid,
(3) Anodizing,
A method for producing a support for a lithographic printing plate, comprising: By transferring the uneven pattern, using an aluminum plate with irregularities on the surface,
(1) Chemical etching treatment in alkaline aqueous solution,
(2) Desmut treatment in acidic aqueous solution
(3) Electrochemical roughening treatment in aqueous nitric acid solution,
(4) Chemical etching treatment in alkaline aqueous solution,
(5) Desmut treatment in acidic aqueous solution
(6) Electrochemical roughening treatment in aqueous hydrochloric acid,
(7) Chemical etching treatment in alkaline aqueous solution,
(8) Desmut treatment in acidic aqueous solution
(9) Anodizing,
A method for producing a support for a lithographic printing plate, comprising:   By transferring the concavo-convex pattern, pits having an average opening diameter of 0.5 to 5 μm and pits having an average opening diameter of 0.05 to 0.3 μm are further superimposed on the concavo-convex portions of the aluminum plate having unevenness formed on the surface. Then, a method for producing a support for a lithographic printing plate, which is subjected to an anodizing treatment or an anodizing treatment and a hydrophilization treatment.   The method for producing a lithographic printing plate support according to any one of claims 1 to 3, wherein the aluminum plate having irregularities formed on the surface is an aluminum plate containing 0.020 to 0.2 mass% of Cu.   The method for producing a lithographic printing plate support according to any one of claims 1 to 4, wherein the concavo-convex pattern is transferred in a final rolling step of the aluminum plate production step.   The method for producing a lithographic printing plate support according to any one of claims 1 to 5, further comprising a hydrophilic treatment after the anodizing treatment.   A lithographic printing plate precursor further comprising an image recording layer on the support obtained by the production method according to claim 1.

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