JP2006289854A - Method for manufacturing lithographic printing plate support, and support - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a lithographic printing plate support by which an original plate excellent in both anti-fouling properties and printing resistance for a lithographic printing plate can be obtained. <P>SOLUTION: The method for manufacturing a lithographic printing plate support is composed so that the lithographic printing plate support is obtained by applying first electrochemical roughening processing, in which the surface is roughened by using an AC current in an aqueous solution having a liquid temperature of ≥5°C and <30°C and containing a nitric acid, and second electrochemical roughening processing for roughening the surface by using the AC current in an aqueous solution containing a hydrochloric acid to an aluminum plate 11, in which unevenness is formed to the surface by transferring an uneven pattern, in that order. <P>COPYRIGHT: (C)2007,JPO&INPIT

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.

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

  The surface of an aluminum support for a lithographic printing plate (hereinafter also referred to as “support for a lithographic printing plate”) used in a lithographic printing plate has excellent hydrophilicity and water retention because it is used to carry a non-image area. Therefore, various contradictory performances are required, such as excellent adhesion to the image recording layer formed thereon. If the hydrophilicity of the surface of the lithographic printing plate support is too low, ink will adhere to the non-image area during printing, and the blanket cylinder will be soiled, and so-called background soiling will occur. That is, the stain resistance is deteriorated. Also, if the surface water retention is too low, there will be inconveniences such as the occurrence of clogging in the shadow area unless the amount of water shown during printing is increased. On the other hand, if the adhesiveness with the image recording layer is too low, the image recording layer is easily peeled off, and the durability (printing durability) is deteriorated when the number of printed sheets is large.

Therefore, in order to improve various performances such as stain resistance and printing durability, the surface of the lithographic printing plate support is produced by subjecting it 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, the mechanical surface roughening treatment using the nylon brush and the abrasive has an advantage that it can be performed at a high speed and at a low cost. On the other hand, it is difficult to control the particle size of the abrasive. When the agent is mixed, a deep recess is likely to be generated locally. 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 the positive image recording layer to develop locally deep portions of the non-image area. Further, in a lithographic printing plate provided with a negative type image recording layer, a locally deep portion of the image portion is hardly formed as an image. That is, the developability (sensitivity) of the lithographic printing plate is deteriorated.

In order to avoid the occurrence of the problems described above, a method has been proposed that uses an aluminum plate to which a concavo-convex pattern has been transferred, for example, by pressing a rolling roll having a concavo-convex pattern formed on the surface thereof.
For example, Patent Document 1 discloses that (1) an aqueous solution of hydrochloric acid is formed by (1) electrochemical surface roughening in an aqueous nitric acid solution using an aluminum plate having an uneven surface formed by forming an uneven pattern. A method for producing a support for a lithographic printing plate is described, in which the surface is electrochemically roughened and (3) anodized.

JP 2005-7857 A

The lithographic printing plate precursor using the lithographic printing plate support produced by the production method described in Patent Document 1 as described above has good sensitivity and printing durability and durability when used as a lithographic printing plate. It is excellent in both dirtiness.
However, the present inventor has found that this conventional lithographic printing plate support has room for improving printing durability.

  Therefore, the present invention provides a support for a lithographic printing plate that can be used as a lithographic printing plate precursor having good sensitivity and excellent stain resistance and printing durability when used as a lithographic printing plate. Objective.

  In the aqueous solution containing nitric acid, the present invention provides a mechanical surface roughening treatment for forming irregularities on the surface by transferring at least an irregular pattern to an aluminum plate, and a liquid temperature of 5 ° C. or higher and lower than 30 ° C. The first electrochemical roughening treatment for roughening the surface using alternating current, and the second electrochemical roughening treatment for roughening the surface using alternating current in an aqueous solution containing hydrochloric acid. The lithographic printing plate support can be made into a lithographic printing plate precursor having good sensitivity and excellent stain resistance and printing durability when made into a lithographic printing plate. I found out that

That is, the present invention provides the following (1) to (3).
(1) Roughening of the surface using an alternating current in an aqueous solution containing nitric acid that has a liquid temperature of 5 ° C. or higher and lower than 30 ° C., on an aluminum plate having irregularities formed on the surface by transferring the uneven pattern The first electrochemical surface roughening treatment and the second electrochemical surface roughening treatment to roughen the surface using an alternating current in an aqueous solution containing hydrochloric acid are performed in this order, and are used for lithographic printing plates. A method for producing a support for a lithographic printing plate, which obtains a support.
(2) The aluminum plate subjected to the second electrochemical surface roughening treatment is further subjected to an anodizing treatment and a hydrophilic treatment for hydrophilizing the surface using an aqueous solution containing sodium silicate, The method for producing a lithographic printing plate support according to (1) above, wherein a lithographic printing plate support is obtained.
(3) The concavo-convex pattern is transferred by pressing a rolling roll onto an aluminum plate, and a surface of the rolling roll is roughened by an air blast method and in a chromium plating solution using the rolling roll as an anode. The method for producing a lithographic printing plate support according to (1) or (2) above, wherein the roughening treatment by electrolytic treatment and chromium plating are performed in this order.

  According to the present invention, a lithographic printing plate that can be used as a lithographic printing plate precursor having good sensitivity when used as a lithographic printing plate and having excellent stain resistance and printing durability when used as a lithographic printing plate. A support can be obtained.

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 mainly composed of dimensionally stable aluminum, and is made of aluminum or an aluminum alloy. In addition to a pure aluminum plate, an alloy plate containing aluminum as a main component and a trace amount of foreign elements can also be used.

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

As described above, the composition of the aluminum plate used in the present invention is not specified. For example, a conventionally known material described in the fourth edition of the Aluminum Handbook (1990, published by Light Metal Association), for example, JIS Al-Mn aluminum plates such as A1050, JIS A1052, JIS A1100, JIS A1070, JIS A3004 containing Mn, and internationally registered alloy 3103A can be used as appropriate. 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 the UBC (Used Beverage Can) ingot which melt | dissolved the used aluminum beverage can can also be used.

The aluminum plate used in the method for producing a lithographic printing plate support of the present invention preferably contains 0.0 to 0.25% by mass of Cu, more preferably 0.0 to 0.06% by mass. preferable. When the Cu content of the aluminum plate is within this range, a relatively large and more uniform recess is formed in the first electrochemical surface roughening treatment described later. As a result, the lithographic printing plate using the obtained lithographic printing plate support is more excellent in printing durability.
The Cu content is more preferably 0.15% by mass or less, more preferably 0.12% by mass in terms of generating a uniform recess (honeycomb pit) in the first electrochemical surface roughening treatment described later. More preferably, it is more preferably 0.10% by mass or less.
Preference is given to Si: 0.07 to 0.09 mass%, Fe: 0.20 to 0.29 mass%, Mn: 0.01 mass% or less, Mg: 0.01 mass% or less, Cr: 0.0. It is an aluminum plate having a content of 01% by mass or less, Zn: 0.01% by mass or less, Ti: 0.02% by mass or less, and Al: 99.4% by mass or more.

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

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

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

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

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

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

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

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

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

Next, casting is performed using the molten metal that has been subjected to the cleaning treatment as described above. Regarding the casting method, there are a method using a solid mold typified by a DC casting method and a method using a driving mold typified by a continuous casting method.
In DC casting, solidification occurs at a cooling rate 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. Regarding the intermediate annealing condition and the cold rolling condition when using the continuous casting method, the techniques proposed by the applicant of the present application are disclosed in JP-A-6-220593, JP-A-6-210308, JP-A-7-54111, It is described in JP-A-8-92709.

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

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

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

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

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

The aluminum plate used in the present invention has irregularities on the surface. The unevenness on the surface may be formed in advance by transferring the uneven pattern, or may be formed by transferring the uneven pattern.
Although the process of forming unevenness by transferring the uneven pattern to the aluminum plate is not limited, it is preferable to use a rolling roll.
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 with unevenness on the surface is pressed against the aluminum plate to make the uneven shape A method of transferring and forming an uneven pattern on the surface of the aluminum plate 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 electrochemical roughening treatment. it can. In addition, since the unevenness of the surface of the obtained lithographic printing plate support becomes uniform and the formation of locally deep recesses is reduced, the resulting lithographic printing original plate has good sensitivity. .

  Rolling for transfer is preferably performed in 1 to 3 passes, and each rolling reduction is preferably 1 to 8%.

Examples of a method for obtaining a rolling roll having irregularities on the surface used for unevenness transfer include, for example, a method of roughening the surface of a steel roll by wet or dry shot blasting, or a rough surface by wet or dry sandblasting. A method of polishing, a method of polishing with a grindstone or paper containing abrasive grains, a method of generating a dent by irradiating a laser, a method of performing chemical roughening or electrochemical roughening, and a combination thereof The method etc. are mentioned.
In addition, when performing a chemical surface roughening process or an electrochemical surface roughening process, a resist may be apply | coated to the aluminum plate surface, a pattern may be formed by exposing and developing, and it may etch according to a pattern. .

  Among them, a method is preferable in which after the surface of the roll is roughened by an air blast method, electrolytic treatment is performed using the roll as an anode in a chromium plating solution, and then the surface of the roll is subjected to hard chromium plating.

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. When the 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 rolling 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. Since the surface roughness of a magnitude | size sufficient as a rolling roll is obtained as it is the said range, the surface roughness of the aluminum plate which provided the unevenness | corrugation using this rolling roll becomes large enough. 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).

Electrolytic processing anode rolling roll in the chromium plating solution is a plating solution used in the hard chrome plating, using a direct current, preferably carried out in an electrical quantity of 1000~20000C / dm ^2.

Hard chromium plating can be performed by electroplating using a conventionally known CrO ₃ —SO ₄ bath, CrO ₃ —SO ₄ —fluoride bath, or the like as an industrial chromium plating method.
The thickness of the hard chrome plating film is preferably 5 to 15 μm. 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.
By applying hard chrome plating, the rolling roll has improved wear resistance and a long life.

  In addition, methods for obtaining rolling rolls having irregularities on the surface include, for example, JP-A-60-36195, JP-A-2002-251005, JP-A-60-203495, JP-A-55-74898, and JP-A-5-74898. You may use the method described in each gazette of 62-1111792.

The average surface roughness (R _a ) of the surface of the rolling roll is preferably 0.4 to 1.0 μm, and more preferably 0.6 to 0.9 μm.
Number of peaks of the surface of the rolling 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 a rolling roll is not specifically limited, For example, the well-known material for rolling rolls can be used.
In the present invention, it is preferable to use a steel roll. Among these, a roll made by casting is preferable. An example of a composition of a preferable roll material is C: 0.07 to 6% by mass, Si: 0.2 to 1% by mass, Mn: 0.15 to 1% by mass, P: 0.03% by mass or less, S: 0.03% by mass or less, Cr: 2.5 to 12% by mass, Mo: 0.05 to 1.1% by mass, Cu: 0.5% by mass or less, V: 0.5% by mass or less, balance: iron And inevitable impurities.
Further, tool steel (SKD), high-speed steel (SKH), high carbon chromium bearing steel (SUJ), and forged steel containing carbon, chromium, molybdenum, and vanadium as alloy elements, which are generally used as rolling rolls, can be mentioned. It is done. In order to obtain a long roll life, a high chromium alloy cast iron containing about 10 to 20% by mass of chromium can also be used.
Among these, it is preferable to use a roll manufactured by a forging method. In this case, the hardness after quenching and tempering is preferably 80 to 100 in terms of Hs, and more preferably 95 to 100. 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.

In the aluminum plate used for this invention, it is preferable that the uneven | corrugated pitch formed in the surface is 10-100 micrometers.
Moreover, it is preferable that average surface roughness _Ra is 0.4-1.5 micrometers, and it is more preferable that it is 0.4-0.8 micrometers. R _max is preferably 1 to 6 μm, and more preferably 2 to 5 μm. R _Sm is preferably 10 to 150 μm, and more preferably 20 to 100 μm.
The number of pits on the surface is preferably 200 to 20000 / mm ² .

The measuring method of the average surface roughness _Ra of the rolling roll and the aluminum plate is a two-dimensional roughness measurement with a stylus type roughness meter (for example, sufcom 575, manufactured by Tokyo Seimitsu Co., Ltd.), and is defined in ISO 4287. an arithmetic mean roughness R _a who is measured 5 times, and the average value and the average surface roughness R _a.
The conditions for the two-dimensional roughness measurement are shown below.
<Measurement conditions>
Cut-off value 0.8mm, tilt correction FLAT-ML, measurement length 3mm, vertical magnification 10,000 times, scanning speed 0.3mm / sec, stylus tip diameter 2μm
R _max and R _Sm can be measured in accordance with ISO4287.

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

  The thickness of the aluminum plate used in the present invention is about 0.1 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>
In the method for producing a lithographic printing plate support of the present invention, at least the surface of the aluminum plate described above is roughened using an alternating current in an aqueous solution having a liquid temperature of 5 ° C. or higher and lower than 30 ° C. and containing nitric acid. Electrochemical roughening treatment (hereinafter also referred to as “first electrochemical roughening treatment”) and electrochemical roughening of the surface using an alternating current in an aqueous solution containing hydrochloric acid. Surface treatment (hereinafter also referred to as “second electrochemical surface roughening treatment”) is performed in this order to obtain a lithographic printing plate support.
In addition, it is preferable that the aluminum plate subjected to the second electrochemical surface roughening treatment is further subjected to an anodizing treatment and a hydrophilizing treatment for hydrophilizing the surface using an aqueous solution containing sodium silicate. .

Moreover, in the manufacturing method of the support for lithographic printing plates of this invention, various processes other than the above may be included.
Specifically, for example, an aluminum plate is etched in an alkaline aqueous solution (hereinafter also referred to as “first etching treatment”), and a desmut treatment in an acidic aqueous solution (hereinafter also referred to as “first desmutting treatment”). ), First electrochemical surface roughening treatment, etching treatment in an alkaline aqueous solution (hereinafter also referred to as “second etching treatment”), desmutting treatment in an acidic aqueous solution (hereinafter also referred to as “second desmutting treatment”). ), Second electrochemical roughening treatment, etching treatment in an alkaline aqueous solution (hereinafter also referred to as “third etching treatment”), desmutting treatment in an acidic aqueous solution (hereinafter also referred to as “third desmutting treatment”). And a method of performing anodizing treatment in this order is preferable.
Further, a method of applying a sealing treatment after the anodizing treatment is also preferable, and a method of applying a hydrophilic treatment after the anodizing treatment or sealing treatment is more preferable.

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

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

Before the first electrochemical surface roughening, it is preferable to perform a first alkali etching treatment. The first alkaline etching treatment is to form uniform concave portions by the first electrochemical roughening treatment, and to remove rolling oil, dirt, natural oxide film, etc. on the surface of the aluminum plate (rolled aluminum). Done as a 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 the first electrochemical surface roughening process, and unevenness may occur. On the other hand, when there is too much etching amount, the usage-amount of alkaline aqueous solution will increase and it will become economically disadvantageous.

  Examples of the alkali used in the alkaline solution include caustic alkali and alkali metal salts. Specifically, examples of caustic alkali include caustic soda and caustic potash. Examples of the alkali metal salt include alkali metal silicates such as sodium metasilicate, sodium silicate, potassium metasilicate, and potassium silicate; alkali metal carbonates such as sodium carbonate and potassium carbonate; sodium aluminate and alumina. Alkali metal aluminates such as potassium acid; alkali metal aldones such as sodium gluconate and potassium gluconate; dibasic sodium phosphate, dibasic potassium phosphate, 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 alkaline 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 first alkali etching treatment is completed, it is preferable to drain the liquid with a nip roller, and further perform the water washing treatment for 1 to 10 seconds and then drain the liquid with a nip roller.
The water washing treatment is preferably carried out using an apparatus for washing with a free-falling curtain-like liquid film, and further using a spray tube.

FIG. 1 is a schematic cross-sectional view of an apparatus for washing with a free-fall curtain-like liquid film. As shown in FIG. 1, an apparatus 100 for performing water washing treatment with a free-fall curtain-like liquid film includes a water storage tank 104 that stores water 102, a water supply pipe 106 that supplies water to the water storage tank 104, and a water storage tank. And a rectifying unit 108 for supplying a free-falling curtain-like liquid film from 104 to the aluminum plate 1.
In the apparatus 100, water 102 is supplied to the water supply tank 104 from the water supply pipe 106, and when the water 102 overflows from the water supply tank 104, the water is rectified by the rectifying unit 108, and a free-falling curtain-like liquid film is applied to the aluminum plate 1. Supplied. When the apparatus 100 is used, the liquid amount is preferably 10 to 100 L / min. Moreover, it is preferable that the distance L where the water 102 between the apparatus 100 and the aluminum plate 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, it is preferable to perform pickling (first desmutting treatment) in order to remove dirt (smut) remaining on the surface. The desmut treatment is performed by bringing an aluminum plate into contact with an acidic solution.

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

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

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

  The liquid temperature of the acidic solution is preferably 20 ° C. or higher, more preferably 30 ° C. or higher, 70 ° C. or lower, more preferably 60 ° C. or lower.

  In the first desmut treatment, the treatment time is preferably 1 second or more, more preferably 3 seconds or more, and preferably 60 seconds or less, more preferably 10 seconds or less. .

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

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

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

<First electrochemical roughening treatment>
The first electrochemical surface roughening treatment is an electrochemical surface roughening treatment using an alternating current in an aqueous solution containing nitric acid (hereinafter referred to as “first electrolytic solution”). By performing the first electrochemical surface roughening treatment, a concavo-convex structure having pits having an average opening diameter of 1 to 6 μm can be formed on the surface of the aluminum plate, and a lithographic plate using the obtained lithographic printing plate support The printing plate has excellent printing durability.
If the aluminum plate contains a relatively large amount of Cu, the first electrochemical surface roughening treatment forms relatively large and uniform recesses (pits) on the surface of the aluminum plate. . As a result, the lithographic printing plate using the obtained lithographic printing plate support is more excellent in printing durability.

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

Various electrolyzers and power sources have been proposed, including US Pat. No. 4,203,637, JP-A-56-123400, JP-A-57-59770, JP-A-53-12738, JP 53-32821, JP 53-32222, JP 53-32823, JP 55-122896, JP 55-13284, JP 62-127500, JP Those described in JP-A-1-52100, JP-A-1-52098, JP-A-60-67700, JP-A-1-230800, JP-A-3-257199 and the like can be used.
Also, JP-A-52-58602, JP-A-52-152302, JP-A-53-12738, JP-A-53-12739, JP-A-53-32821, JP-A-53-32822, JP 53-32833, JP 53-32824, JP 53-32825, JP 54-85802, JP 55-122896, JP 55-13284, JP 48-28123, JP-B-51-7081, JP-A-52-13338, JP-A-52-133840, JP-A-52-133844, JP-A-52-133845, JP-A-53-149135 And those described in JP-A No. 54-146234 and the like can also be used.

The concentration of nitric acid in the first electrolytic solution is preferably 1 to 15 g / L, and more preferably 7.5 to 12.5 g / L.
Moreover, it is preferable that the aluminum ion concentration of a 1st electrolyte solution is 1-15 g / L, and it is more preferable that it is 1.5-10 g / L.
Moreover, it is preferable that the 1st electrolyte solution contains 10-150 mg / L ammonium ion.
The first electrolytic solution can be used by adding at least one of nitric acid compounds having nitrate ions such as aluminum nitrate, sodium nitrate, and ammonium nitrate in a range from 1 g / L to saturation. Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, a silica, may melt | dissolve in the 1st electrolyte solution.

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

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

The liquid temperature of the first electrolytic solution is 5 ° C. or higher and lower than 30 ° C., and preferably 20 to 25 ° C.
When it is in the above range, the printing durability is sufficient, and the cooling cost of the first electrolytic solution can be suppressed.

The waveform of the alternating current 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, in particular, when an aqueous solution containing nitric acid is used, it becomes susceptible to the influence of trace components in the first electrolytic solution typified by ammonium ions and the like that increase spontaneously by electrolytic treatment. Graining is less likely to occur. As a result, the stain resistance tends to decrease when a lithographic printing plate is obtained.
Current density, in the main electrolytic cell, the peak current density during the aluminum plate anode reaction, preferably ^{10~300A / dm 2, 15~200A / dm} 2 is more preferable.

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

One or more AC power supplies can be connected to the electrolytic cell. As shown in FIG. 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 (cathode amount of electricity / anode amount of electricity) is preferably 0.3 to 1.0. It is more preferably 9 to 0.98.

  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.

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

After the first electrochemical surface roughening treatment is completed, it is preferable to drain the liquid with a nip roller, and further perform the water washing treatment for 1 to 10 seconds and then drain the liquid with a nip roller.
The washing treatment is preferably carried out using a spray tube. As the spray tube used for the water washing treatment, for example, a spray tube having a plurality of spray tips in the width direction of the aluminum plate in which fan water spreads in a fan shape can be used. The 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.

Note that if the following pre-electrolysis is performed before the first electrochemical surface roughening treatment, deep recesses are not formed in the first electrochemical surface roughening treatment.
Pre-electrolysis is a step of forming the starting point of pit formation during the first electrochemical surface roughening treatment. By performing slight electrolysis using hydrochloric acid which is not easily affected by the material of the aluminum plate and is highly corrosive, pits can be formed uniformly on the surface.
In pre-electrolysis, the hydrochloric acid concentration is preferably 1 to 15 g / L, and the amount of electricity at the time of 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 .

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

<Second alkali etching treatment>
After the first electrochemical surface roughening treatment, a second alkali etching treatment is preferably performed. The purpose of the second alkali etching treatment is to dissolve the smut generated by the first electrochemical roughening treatment and to dissolve the edge portion of the pit formed by the first electrochemical roughening treatment. As done. 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 the first electrochemical surface roughening process will not be smooth in the non-image area of the lithographic printing plate, and the ink will be easily caught, resulting in poor stain resistance. There is a case. On the other hand, if the etching amount is too large, the unevenness generated by the first electrochemical surface roughening treatment becomes small, so that the printing durability may be deteriorated.

In the second 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 liquid 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, it is preferable to perform pickling (second desmut treatment) in order to remove dirt (smut) remaining on the surface. Since the second desmut process is basically the same as the first desmut process, only the differences will be described below.
In the second desmut treatment, nitric acid or sulfuric acid is preferably used.
In the second 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. .

<Second electrochemical roughening treatment>
The second electrochemical surface roughening treatment is an electrochemical surface roughening treatment using an alternating current in an aqueous solution containing hydrochloric acid (hereinafter referred to as “second electrolytic solution”). A pit having an average opening diameter of 0.01 to 0.5 μm is obtained by applying a first electrochemical roughening treatment to the aluminum plate to which the irregularities are transferred, and then a second electrochemical roughening treatment. A concavo-convex structure having can be formed on the surface of the aluminum plate. As a result, the lithographic printing plate using the obtained lithographic printing plate support is more excellent in printing durability.

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

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

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

Since hydrochloric acid itself has a strong ability to dissolve aluminum, it is possible to form fine irregularities on the surface with only slight electrolysis. The fine irregularities have an average opening diameter of 0.01 to 0.5 μm and are uniformly generated on the entire surface of the aluminum plate. In order to obtain such a grain, the total amount of electricity involved in the anode reaction of the aluminum plate at the time when the electrolytic reaction is completed is preferably 10 C / dm ² or more, more preferably 50 C / dm ² or more. Is more preferably 100 C / dm ² or less, and more preferably 80 C / dm ² or less. The current density at this time is preferably 10 to 300 A / dm ² , more preferably 15 to 200 A / dm ² in terms of the peak current density during the anodic reaction of the aluminum plate in the main electrolytic cell.

  The waveform of the alternating current 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. . When using a trapezoidal wave, TP is preferably 0.5 to 3 msec, and more preferably 0.6 to 1.5 msec.

When the aluminum plate is continuously subjected to electrolytic surface roughening, the concentration of aluminum ions in the alkaline solution increases, and the unevenness of the aluminum plate formed by the second electrochemical surface roughening treatment varies. To do. Therefore, the composition management of the second electrolytic solution is preferably performed as follows.
That is, a matrix of conductivity, specific gravity, and temperature, or a matrix of conductivity, ultrasonic propagation velocity, and temperature corresponding to the matrix of 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 measurement of the liquid composition are used for measurement after being controlled at a constant temperature (for example, 35 ± 0.5 ° C.) using a heat exchanger different from the electrolyte. However, it is preferable in that the accuracy of measurement is increased.

<Third alkali etching treatment>
After the second electrochemical roughening treatment, a third alkali etching treatment is preferably performed. The third alkali etching treatment is intended to dissolve the smut generated by the second electrochemical roughening treatment and to dissolve the edge portion of the pit formed by the second electrochemical roughening treatment. As done. 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 0.01 g / m ² or more, more preferably 0.05 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 the second electrochemical surface roughening process will not be smooth in the non-image area of the lithographic printing plate, and the ink will be easily caught, resulting in poor stain resistance. There is a case. On the other hand, if the etching amount is too large, the unevenness generated by the first electrochemical surface roughening treatment and the second electrochemical surface roughening treatment becomes small, so that the printing durability may deteriorate.

In the third alkali etching treatment, the concentration of the alkali solution is preferably 30 g / L or more, and in order not to make the unevenness caused by the second electrochemical roughening treatment in the previous stage too small. , 100 g / L or less is preferable, and 70 g / L or less is more preferable.
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 liquid temperature of the alkaline 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, pickling (third desmutting treatment) is preferably performed 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, which eliminates 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 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 15 seconds or shorter. .
In the third desmutting treatment, when the same type of electrolyte as that used in the subsequent anodizing treatment is used as the desmutting treatment, it is possible to omit the draining and washing with a nip roller after the desmutting treatment.

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

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

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

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

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

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

  The liquid temperature of the electrolytic solution is preferably 25 to 55 ° C., 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 anodizing treatment, so as not to cause so-called “burn” (part where the film becomes thicker than the surrounding area) due to current concentration on a part of the aluminum plate, It is preferable to increase the current density to 30 to 50 A / dm ² or higher as the anodic oxidation process proceeds with a current flowing at a low current density of 5 to 10 A / m ² .
Specifically, it is preferable that the current distribution of the DC power supply is set so that the current of the downstream DC power supply is equal to or greater than the current of the upstream DC power supply. By using such current distribution, so-called burning is less likely to occur, and as a result, high-speed anodization can be performed.

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

The amount of the anodized film is preferably 1 to 5 g / m ² . If it is less than 1 g / m ² , the plate is likely to be scratched. On the other hand, if it exceeds 5 g / m ² , a large amount of 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 carried out by the apparatus and method described in JP-B-56-12518, JP-A-4-4194, JP-A-5-20296, JP-A-5-179482, etc. Good.

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

Further, phosphates described in JP-A No. 62-019494, water-soluble epoxy compounds described in JP-A No. 62-033692, and JP-A No. 62-097892 Phosphoric acid modified starch, diamine compounds described in JP-A-63-056498, inorganic or organic acids of amino acids described in JP-A-63-130391, JP-A-63-145092 Organic phosphonic acids containing a carboxy group or hydroxy group, compounds having an amino group and a phosphonic acid group described in JP-A-63-165183, and JP-A-2-316290 Specific carboxylic acid derivatives, phosphate esters described in JP-A-3-215095, JP-A-3-261592 Compounds having one amino group and one oxygen acid group of phosphorus described in the publication, phosphoric esters described in JP-A-3-215095, and JP-A-5-246171 Aliphatic or aromatic phosphonic acids such as phenylphosphonic acid, compounds containing S atoms such as thiosalicylic acid described in JP-A-1-307745, phosphorus described in JP-A-4-282737 Examples of the treatment include undercoating using a compound having a group of oxygen acids.
Further, coloring with an acid dye described in JP-A-60-64352 can also be performed.

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

Hydrophilization treatment with an aqueous solution of an alkali metal silicate such as sodium silicate and potassium silicate is described in US Pat. No. 2,714,066 and US Pat. No. 3,181,461. It can be performed according to methods and procedures.
Examples of the alkali metal silicate include sodium silicate, potassium silicate, and lithium silicate. The aqueous solution of alkali metal silicate may contain an appropriate amount of sodium hydroxide, potassium hydroxide, lithium hydroxide or the like.
Examples of the alkali metal silicate include sodium silicate, potassium silicate, and lithium silicate. No. 1 sodium silicate or No. 3 sodium silicate is preferably used, and No. 1 sodium silicate is used. Is more preferable. By using No. 1 sodium silicate, the stain resistance of the lithographic printing plate precursor using the obtained lithographic printing plate precursor support is improved.
When No. 1 sodium silicate is used in the aqueous solution used for the hydrophilization treatment, the concentration of No. 1 sodium silicate is preferably 1 to 10% by mass, and the liquid temperature is preferably 10 to 30 ° C. The treatment time is preferably 1 to 15 seconds.
The aqueous solution of alkali metal silicate may contain an alkaline earth metal salt or a Group 4 (Group IVA) metal salt. Examples of the alkaline earth metal salt include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate; sulfates; hydrochlorides; phosphates; acetates; oxalates; Examples of the Group 4 (Group IVA) metal salt include titanium tetrachloride, titanium trichloride, potassium fluoride titanium, potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride. And zirconium tetrachloride. These alkaline earth metal salts and Group 4 (Group IVA) metal salts are used alone or in combination of two or more.

The amount of Si adsorbed by the alkali metal silicate treatment can be measured with a fluorescent X-ray analyzer, and the amount of adsorption is preferably about 1 to 10 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. Moreover, as a hydrophilic compound used for this method, the compound which has at least one chosen from the group which consists of -NH2 group, -COOH group, and a sulfo group, for example is mentioned.

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

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

[Lithographic printing plate precursor]
The lithographic printing plate support obtained by the present invention can be provided with an image recording layer to form the lithographic printing plate precursor of the present invention. A photosensitive composition is used for the image recording layer.
Examples of the photosensitive composition suitably used in the present invention include a thermal positive photosensitive composition containing an alkali-soluble polymer compound and a photothermal conversion substance (hereinafter, this composition and an image recording layer using the same). ), A thermal negative photosensitive composition containing a curable compound and a photothermal conversion substance (hereinafter also referred to as “thermal negative type”), a photopolymerizable photosensitive composition (hereinafter referred to as “thermal positive type”). , Also referred to as “photopolymer type”), a negative photosensitive composition containing a diazo resin or a photocrosslinking resin (hereinafter also referred to as “conventional negative type”), and a positive photosensitive composition containing a quinonediazide compound. Product (hereinafter also referred to as “conventional positive type”), a photosensitive composition that does not require a special development step (hereinafter referred to as “the conventional positive type”). Like 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 (—SO 2 NH—R (wherein R represents a hydrocarbon group)), an active imino group (—SO 2 NHCOR, —SO 2 NHSO 2 R, —CONHSO 2 R (wherein R is the above) The resin having an acidic group such as)) is preferable in terms of solubility in an alkali developer.
In particular, a resin having a phenolic hydroxy group is preferable in that it has excellent image-forming properties when exposed to light such as an infrared laser, and examples thereof include phenol-formaldehyde resins, m-cresol-formaldehyde resins, p-cresol-formaldehyde resins, m- / p-mixed cresol-formaldehyde resin, phenol / cresol (any of m-, p- and m- / p-mixed) mixed-formaldehyde resin (phenol-cresol-formaldehyde co-condensation resin) and other novolak resins Are preferable.
Furthermore, a polymer compound described in JP-A No. 2001-305722 (particularly [0023] to [0042]), and a 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 can contain a dissolution inhibitor. As the dissolution inhibitor, for example, a dissolution inhibitor as described in JP-A-2001-305722, [0053] to [0055] is preferably exemplified.
In addition, in the thermal positive type photosensitive composition, as a additive, a sensitivity modifier, a printing agent for obtaining a visible image immediately after heating by exposure, a compound such as a dye as an image colorant, a coating property In addition, it is preferable to include a surfactant for improving the processing stability. For these, compounds described in JP-A-2001-305722, [0056] to [0060] are preferable.
The photosensitive composition described in detail by Unexamined-Japanese-Patent No. 2001-305722 is preferably used also in respects other than the above.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  The conventional negative type photosensitive composition has, as additives, the bake-out 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 coatability.

  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, ResearchDisclosureNo. 33303 (January 1992), JP-A-9-123387, JP-A-9-131850, JP-A-9-171249, and JP-A-9-171250, and European Patent Application Publication No. 931,647. Preferred examples thereof include thermoplastic fine particle polymers. Of these, polystyrene and polymethyl methacrylate are preferred. Examples of the fine particle polymer having a hydrophilic surface include those in which the polymer itself is hydrophilic; those in which a hydrophilic compound such as polyvinyl alcohol and polyethylene glycol is adsorbed on the surface of the fine particle polymer to make the surface hydrophilic.
The fine particle polymer preferably has a reactive functional group.

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

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

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

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

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

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

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

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
1. Production of rolling roll C: 0.9 mass%, Si: 0.4 mass%, Mn: 0.3 mass%, P: 0.01 mass%, S: 0.01 mass%, Cr: 3 mass%, Mo: 0.1% by mass, balance: Iron and steel, which is an inevitable impurity, are manufactured by a forging method, and a roll having a hardness of Hs97 is sequentially subjected to the following treatments (1) to (5) and rolled. Got a roll.

(1) Mirror polishing treatment A buffing treatment was performed as a mirror polishing treatment to remove traces of the grindstone that polished the roll surface. On the polished surface, the average surface roughness _Ra was 0.2 μm, and the maximum height R _max was 1 μm. The average surface roughness R _a is stylus roughness meter (e.g., Sufcom575, manufactured by Tokyo Seimitsu Co., Ltd.) subjected to two-dimensional roughness measurement, the five arithmetic mean roughness R _a as defined in ISO4287 The average value measured. The conditions for the two-dimensional roughness measurement performed are shown below.
<Measurement conditions>
Cut-off value 0.8mm, tilt correction FLAT-ML, measurement length 3mm, vertical magnification 10,000 times, scanning speed 0.3mm / sec, stylus tip diameter 2μm
R _max was measured according to ISO 4287.

(2) Blasting treatment The surface of the roll was roughened by performing an air blasting process using # 100 mesh alumina particles as a grid material twice. The spray pressure was 2 kgf / cm ² (1.96 × 10 ⁵ Pa) for each time of the air blast method. On the surface after blasting, the average surface roughness _Ra was 0.9 μm.

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

(4) Electrolytic treatment In an electrolytic solution containing chromic acid 300 g / L, sulfuric acid 2 g / L, and iron 1 g / L at a liquid temperature of 50 ° C., a continuous DC current is applied using a roll as an anode, and electrolysis is performed at a current density of 30 A / dm ² . Processed. The amount of electricity was 17000 C / dm ² .
The current waveform used was a direct current that was rectified in three phases. The counter electrode was lead. The roll was placed vertically in the electrolyte, and a lead electrode was arranged in a cylindrical shape so as to surround the periphery. The shaft portion of the roll was masked with vinyl chloride so that no electrolytic treatment was performed.

(5) Chromium plating treatment Next, in a 50 ° C. electrolytic solution containing 300 g / L of chromic acid, 2 g / L of sulfuric acid, and 1 g / L of iron, a continuous DC current was applied using a roll as a cathode to obtain a current density of 40 A / L. a plating treatment was carried out at dm ^2. The plating treatment time was set so that the plating thickness was 6 μm.
The current waveform used was a direct current that was rectified in three phases. The counter electrode was lead. The roll was placed vertically in the electrolyte, and a lead electrode was arranged in a cylindrical shape so as to surround the periphery. The shaft portion of the roll was masked with vinyl chloride so as not to be plated.

The obtained rolling roll having irregularities on the surface had an average surface roughness _Ra of 0.8 μm, R _max of 5 μm, and R _Sm of 50 μm.

2. Preparation of planographic printing plate precursor (Examples 1-1 to 1-39 and Comparative Example 1)
(1) Preparation of aluminum plate After containing each component (mass%) shown in Table 1 and preparing the molten metal using an aluminum alloy consisting of Al and inevitable impurities, the molten metal was processed and filtered. Thus, an ingot having a thickness of 500 mm and a width of 1200 mm was produced by a DC casting method. After the surface was shaved with a chamfering machine with an average thickness of 10 mm, 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 heat treatment was performed at 500 ° C. using a continuous annealing machine, cold rolling was performed using the rolling roll obtained above, finishing to a thickness of 0.6 mm and a width of 1060 mm, and unevenness transferred to the surface Aluminum plates 1 to 6 were obtained.

(2) Production of lithographic printing plate support Next, the aluminum plate obtained above is subjected to surface treatment by continuously performing the following various treatments (b) to (k), and lithographic printing is performed. A plate support was prepared.

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

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

(D) First electrochemical surface roughening treatment Next, using the electrolytic solution having the nitric acid concentration, the aluminum ion concentration, and the liquid temperature shown in Table 2 and the ammonium ion concentration being 70 mg / L, An electrochemical roughening treatment was performed. The aluminum ion concentration was adjusted by adding aluminum nitrate.
An electrochemical surface roughening process was performed using a power source that generates an alternating current having an arbitrary waveform and that is current-controlled by PWM control using an IGBT element.
A carbon electrode was used as the counter electrode, and an iridium oxide electrode was used as the auxiliary anode. As the electrolytic cell, two radial type cells as shown in FIG. 4 were used.
The time TP until the waveform, frequency and current value of the generated alternating current reached the peak from zero is as shown in Table 2, and the duty was 0.5. The current density (average value of alternating current) and the amount of electricity (total amount of electricity during the anode reaction of the aluminum plate) were as shown in Table 2. Further, the ratio of the amount of electricity involved in the anodic reaction and the cathodic reaction on the aluminum plate in the main electrolytic cell (the amount of electricity at the time of cathode / the amount of electricity at the time of anode), that is, the current ratio shown in Table 2 is 0. 95. The current ratio was adjusted by the amount of current diverted to the auxiliary anode.
The aluminum plate was supplied into the main electrolytic cell so that the relative speed with respect to the electrolytic solution in the main electrolytic cell was 1 to 2 m / sec, and the average was 1.5 m / sec.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

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

(F) Desmut treatment in acidic aqueous solution (second desmut treatment)
Next, a desmut treatment was performed. As the acidic aqueous solution, an aqueous solution having a sulfuric acid concentration of 300 g / L and aluminum ions 1.5 g / L dissolved therein was used. The desmutting treatment was performed by spraying the acidic aqueous solution (liquid temperature 30 ° C.) from a spray tube for 10 seconds.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process of (b) above, and then the liquid was drained by a nip roller.

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

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

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

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

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

(3) Production of Image Recording Layer Each lithographic printing plate support obtained above was provided with a thermal positive type image recording layer 1 as follows to obtain a lithographic printing plate precursor.

First, an undercoat solution having the following composition was first applied on 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

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

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

(Examples 1-40 to 1-42)
A support for a lithographic printing plate was obtained by performing a surface treatment in the same manner as in Examples 1-1 to 1-39, except that the treatment (l) described below was performed instead of the treatment (k). .

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

  Next, the multilayer thermal positive type image recording layer 2 was formed on the obtained lithographic printing plate support in the following manner to obtain a lithographic printing plate precursor.

First, an undercoat solution having the following composition was applied and dried at 80 ° C. for 15 seconds to form a coating film of an undercoat layer. The coating amount of the coating film after drying was 15 mg / m ² .

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

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

<Image Recording Layer Coating Liquid B1>
N- (4-aminosulfonylphenyl) methacrylamide / acrylonitrile / methyl methacrylate copolymer (molar ratio 36/34/30, weight average molecular weight 50000) 1.920 g
-M, p-cresol novolak (m-cresol novolak / p-cresol novolak ratio 6/4, weight average molecular weight 4000) 0.213 g
-0.032 g of cyanine dye B represented by the following formula
・ 0.008 g of p-toluenesulfonic acid
・ Tetrahydrophthalic anhydride 0.19g
・ Bis-p-hydroxyphenylsulfone 0.126 g
・ 2-methoxy-4- (N-phenylamino) benzenediazonium ・ hexafluorophosphate 0.032 g
-0.078 g of a dye in which the counter anion of Victoria Pure Blue BOH is a 1-naphthalenesulfonic acid anion
・ Fluorine-based surfactant (Megafac F-780, manufactured by Dainippon Ink & Chemicals, Inc.) 0.020 g
・ Γ-butyrolactone 13.18 g
・ Methyl ethyl ketone 25.41g
・ 1-methoxy-2-propanol 12.97g

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

(Example 2)
Aluminum plate 1 'produced similarly to the aluminum plate 1 except not heat-processing using a continuous annealing machine was produced. A lithographic printing plate precursor was obtained in the same manner as in Example 1-9 except that this aluminum plate 1 'was used.

(Example 3)
An aluminum plate 2 ′ produced in the same manner as the aluminum plate 2 was produced except that heat treatment using a continuous annealing machine was not performed. A lithographic printing plate precursor was obtained in the same manner as in Example 1-40 except that this aluminum plate 2 'was used.

Example 4
An aluminum plate 3 ′ produced in the same manner as the aluminum plate 3 was produced except that the heat treatment using a continuous annealing machine was not performed. A lithographic printing plate precursor was obtained in the same manner as in Example 1-41 except that this aluminum plate 3 'was used.

3. Observation of surface of lithographic printing plate support The surface of each lithographic printing plate support subjected to the hydrophilization treatment of (k) or (l) above was scanned with an electron microscope (JSM-5500, manufactured by JEOL Ltd.). , The same shall apply hereinafter) and observed with a magnification of 50000 times, fine irregularities having an average opening diameter of 0.05 to 0.3 μm were formed uniformly and densely.
Further, when observed at a magnification of 2000 using a scanning electron microscope, irregularities (honeycomb pits) having an average opening diameter of 1 to 6 μm were uniformly formed on the surface of the lithographic printing plate support of Examples 1 to 26. It was.
On the other hand, when the surface of the lithographic printing plate support of Comparative Example 1 was observed in the same manner as in Examples 1-1 to 1-42 using a scanning electron microscope, the unevenness formed on the surface was uneven. there were.

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

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

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

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

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

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

(4) Stain resistance of halftone dot non-image area The lithographic printing plate obtained above was mounted on a printing machine SOR-M manufactured by Heidelberg, and IF102 3% (manufactured by Fuji Photo Film Co., Ltd.) in fountain solution. The ink is printed with Varius (N) ink (Dainippon Ink Chemical Co., Ltd.), and the amount of dampening water is gradually reduced from the standard water scale, and the shadow area (dot rate 80%) The degree of occurrence of entanglement stains was visually evaluated. The results are shown in Table 2. In the table, the meanings of the symbols are as follows.
A: The halftone dot non-image portion is hardly stained. AB: The halftone dot non-image portion is slightly dirty. B: The halftone dot non-image portion is slightly dirty, but is within a practically acceptable range. C: Halftone dot. Non-image area is dirty and cannot be used

As is apparent from Table 2, the planographic printing plate support obtained by the method for producing a planographic printing plate support of the present invention (Examples 1-1 to 1-42, Examples 2 to 4) was used. All of the lithographic printing plates had excellent printing durability, stain resistance, cleaner resistance, and stain resistance of the non-dot image area. Among them, a lithographic printing plate having a large amount of Si adsorbed on the support surface and provided with a multilayer thermal positive type image recording layer 2 (Examples 1-40 to 1-42, Examples 3 and 4). ) Was more excellent in the stain resistance of the halftone dot non-image area.
In Examples 2 to 4 does not perform heat treatment using a continuous annealing machine, CO ₂ amount to be discharged when fabricating the aluminum plate was reduced.
On the other hand, the lithographic printing plate of Comparative Example 1 in which the liquid temperature of the first electrolytic solution was too high was inferior in printing durability and cleaner resistance.

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

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aluminum plate 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 (1)

  For an aluminum plate having irregularities formed on its surface by transferring an irregular pattern, the surface is roughened using an alternating current in an aqueous solution containing at least 5 ° C. and less than 30 ° C. and containing nitric acid. The first electrochemical roughening treatment and the second electrochemical roughening treatment in which the surface is roughened using an alternating current in an aqueous solution containing hydrochloric acid are performed in this order, and the support for the lithographic printing plate A process for producing a support for a lithographic printing plate to obtain a body.

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