JP2006272877A - Method for manufacturing substrate for lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a substrate for a lithographic printing plate capable of obtaining the lithographic printing plate excellent in plate wear and stain resistance. <P>SOLUTION: In the method for manufacturing the substrate for the lithographic printing plate for obtaining the substrate for the lithographic printing plate by at least applying an electrochemical roughened surface treatment on an aluminum plate in an acidic water solution, the acidic water solution contains 0.1-3.0 mass% Cu. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

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

A support for a lithographic printing plate used for a lithographic printing plate is formed using an aluminum plate, and this surface is excellent in hydrophilicity and water retention because it is used to carry a non-image part. Various contradictory performances are required, such as excellent adhesion to the image recording layer formed thereon.
If the surface of the lithographic printing plate support is too low in hydrophilicity, ink will adhere to the non-image area during printing, and the blanket cylinder will be soiled, and so-called background soiling will occur. That is, the stain resistance is deteriorated. In addition, if the surface water retention is too low, there will be inconveniences such as clogging of the shadow portion unless the dampening water is increased during printing. On the other hand, if the adhesion 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.

  Then, an object of this invention is to provide the manufacturing method of the support body for lithographic printing plates which can obtain the lithographic printing plate which is excellent in printing durability and stain resistance.

  As a result of intensive studies to achieve the above object, the present inventor performed an electrochemical surface roughening treatment on an aluminum plate in an acidic aqueous solution containing a predetermined amount of Cu to obtain a lithographic printing plate. The inventors have found that printing durability and stain resistance are excellent, and have completed the present invention.

That is, the present invention provides the following (1) to (4).
(1) A method for producing a lithographic printing plate support, wherein an aluminum plate is subjected to an electrochemical surface roughening treatment in an acidic aqueous solution to obtain a lithographic printing plate support,
The manufacturing method of the support body for lithographic printing plates in which the said acidic aqueous solution contains 0.1-3.0 mass% Cu.
(2) The method for producing a lithographic printing plate support according to (1), wherein the aluminum plate has a Cu content of 0.010% by mass or less.
(3) The lithographic printing plate according to (1) or (2), wherein the electrochemical surface roughening treatment is an electrochemical surface roughening treatment using an alternating current in an aqueous solution containing nitric acid. For producing a support for an automobile.
(4) At least on the aluminum plate
Etching treatment in alkaline solution,
Electrochemical roughening treatment using alternating current in an aqueous solution containing nitric acid,
Etching treatment in an alkaline aqueous solution; and
Electrochemical roughening treatment using alternating current in aqueous solution containing hydrochloric acid,
Is a method for producing a lithographic printing plate support, wherein a lithographic printing plate support is obtained in this order,
A method for producing a lithographic printing plate support, wherein the aqueous solution containing nitric acid and / or the aqueous solution containing hydrochloric acid contains 0.1 to 3.0% by mass of Cu.

  As will be described below, according to the present invention, it is possible to provide a lithographic printing plate support used for a lithographic printing plate precursor which is excellent in stain resistance and printing durability when used as a lithographic printing plate. This is particularly the case when the composition of the aluminum plate used for the lithographic printing plate support, the temperature and concentration of the acidic solution in the electrochemical surface roughening treatment, the conditions such as the power source, and the like are kept unchanged without changing them. However, it is very useful because it can provide a support for a lithographic printing plate having excellent electrolytic properties, excellent stain resistance and printing durability when used as a lithographic printing plate, and excellent balance thereof.

Hereinafter, the present invention will be described in detail.
[Support for lithographic printing plate]
<Aluminum plate (rolled aluminum)>
A known aluminum plate can be used in the method for producing a lithographic printing plate support of the present invention. The aluminum plate used in the present invention is a metal mainly composed of dimensionally stable aluminum, and is made of aluminum or an aluminum alloy. In addition to a pure aluminum plate, an alloy plate containing aluminum as a main component and a trace amount of foreign elements can also be used.

In the present specification, various substrates made of the above-described aluminum or aluminum alloy are generically used as an aluminum plate.
The foreign elements that may be contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium, etc., and the content of the foreign element in the alloy is 10% by mass or less. is there. In particular, in the present invention, the copper content is 0.010% by mass or less by performing an electrochemical surface roughening treatment in an acidic aqueous solution containing a predetermined amount of Cu in the surface treatment described later. It is preferable because the effect of the present invention is easily exhibited.

  Thus, the composition of the aluminum plate used in the present invention is not specified. For example, a conventionally known material described in the fourth edition of the Aluminum Handbook (1990, published by the Light Metal Association), for example, JIS Al-Mn based 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.

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

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

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

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

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

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

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

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

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

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

  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.

Various characteristics described below are desired for the aluminum plate thus manufactured.
As for the strength of the aluminum plate, it is preferable that the 0.2% proof stress is 140 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 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.

  In the present invention, an aluminum plate as shown above can be used with unevenness by lamination rolling, transfer, or the like in the final rolling step.

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

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

<Surface treatment>
In the method for producing a lithographic printing plate support of the present invention, the above-described aluminum plate is subjected to an electrochemical surface roughening treatment (hereinafter referred to as “specific electrolytic surface roughening treatment” in an acidic aqueous solution containing at least a predetermined amount of Cu. To obtain a lithographic printing plate support.

In the following, as a representative method for forming a suitable surface grain shape,
A method of sequentially performing mechanical surface roughening treatment, alkali etching treatment, desmutting treatment with acid, and the specific electrolytic surface roughening treatment on an aluminum plate;
The aluminum plate is subjected to mechanical roughening treatment, alkali etching treatment, desmutting treatment with acid, and electrochemical roughening treatment in different acidic aqueous solutions a plurality of times (at least one of the plurality of electrochemical roughening treatments). Times are the above-mentioned specific electrolytic surface-roughening treatment)
A method of sequentially performing an alkali etching treatment, an acid desmutting treatment and the specific electrolytic surface roughening treatment on an aluminum plate;
The aluminum plate is subjected to alkali etching treatment, desmutting treatment with acid, and electrochemical roughening treatment in different acidic aqueous solutions a plurality of times (at least one of the electrochemical roughening treatments is the specific electrolytic roughening surface). Process);
However, the present invention is not limited to these.
In these methods, after electrochemical surface roughening treatment in an acidic aqueous solution, alkali etching treatment and acid desmutting treatment may be performed, and further, anodizing treatment, sealing treatment, and hydrophilic treatment treatment may be performed. Also good.
Hereinafter, each step of the surface treatment will be described in detail.

<Mechanical roughening>
In the present invention, it is preferable to first perform a mechanical surface roughening treatment.
Examples of the mechanical surface roughening treatment include, for example, a wire brush grain method in which the aluminum surface is scratched with a metal wire, a ball grain method in which the aluminum surface is grained with a polishing ball and an abrasive, JP-A-6-135175, and Japanese Patent Publication A brush grain method in which the surface is grained with a nylon brush and an abrasive described in Japanese Patent No. 50-40047 can be used.
A transfer method in which the uneven surface is pressed against the aluminum plate can also be used. That is, in addition to the methods described in JP-A-55-74898, JP-A-60-36195, and JP-A-60-20396, transfer is performed several times. The method described in JP-A-6-24168 and JP-A-6-24168 characterized in that the surface is elastic is also applicable.

In addition, by using electric discharge machining, shot blasting, laser, plasma etching, etc., a method of repeatedly transferring using a transfer roll etched with fine irregularities, and an uneven surface coated with fine particles on an aluminum plate It is also possible to use a method in which an uneven pattern corresponding to the average diameter of the fine particles is repeatedly transferred to the aluminum plate a plurality of times by contacting the surface and applying a pressure a plurality of times from above. As a method for imparting fine irregularities to the transfer roll, known methods described in JP-A-3-8635, JP-A-3-66404, JP-A-63-65017, etc. may be used. it can. Further, a fine groove may be cut in two directions using a die, a cutting tool, a laser, or the like on the roll surface, and a square unevenness may be formed on the surface. The roll surface may be subjected to a known etching process or the like so that the formed square irregularities are rounded.
Further, in order to increase the surface hardness, quenching, hard chrome plating, or the like may be performed.
In addition, as the mechanical surface roughening treatment, methods described in JP-A Nos. 61-162351 and 63-104889 can be used.
In the present invention, the above-described methods can be used in combination in consideration of productivity and the like. These mechanical surface roughening treatments are preferably performed before the electrochemical surface roughening treatment.

Hereinafter, the brush grain method used suitably as a mechanical roughening process is demonstrated.
The brush grain method generally uses a roller-shaped brush in which a large number of brush hairs such as synthetic resin hair made of synthetic resin such as nylon (trade name), propylene, and vinyl chloride resin are implanted on the surface of a cylindrical body. This is carried out by rubbing one or both of the surfaces of the aluminum plate while spraying a slurry liquid containing an abrasive on a rotating roller brush. Instead of the roller brush and the slurry liquid, a polishing roller which is a roller having a polishing layer on the surface can be used.
When a roller brush is used, the flexural modulus is preferably 10,000 to 40,000 kg / cm ² , more preferably 15,000 to 35,000 kg / cm ² , and the bristle strength is preferably Brush hair of 500 gf or less, more preferably 400 gf or less is used. The diameter of the brush bristles is generally 0.2 to 0.9 mm. The length of the brush bristles can be appropriately determined according to the outer diameter of the roller brush and the diameter of the body, but is generally 10 to 100 mm.

A well-known thing can be used for an abrasive | polishing agent. For example, abrasives such as pumicestone, silica sand, aluminum hydroxide, alumina powder, silicon carbide, silicon nitride, volcanic ash, carborundum, and gold sand; a mixture thereof can be used. Of these, pumiston and silica sand are preferable. In particular, silica sand is preferable in terms of excellent surface roughening efficiency because it is harder and less likely to break than Pamiston.
The average particle diameter of the abrasive is preferably 3 to 50 μm, and more preferably 6 to 45 μm in terms of excellent surface roughening efficiency and a narrow graining pitch.
For example, the abrasive is suspended in water and used as a slurry. In addition to the abrasive, the slurry liquid may contain a thickener, a dispersant (for example, a surfactant), a preservative, and the like. The specific gravity of the slurry liquid is preferably 0.5-2.

  As an apparatus suitable for the mechanical surface roughening treatment, for example, an apparatus described in Japanese Patent Publication No. 50-40047 can be given.

<Electrochemical roughening treatment>
In the present invention, an electrochemical surface roughening treatment (specific electrolytic surface roughening treatment) is performed in an acidic aqueous solution containing 0.1 to 3.0% by mass of Cu. Further, as described above, in the present invention, when the electrochemical surface roughening treatment is performed a plurality of times, at least one time is the specific electrolytic surface roughening treatment.
Here, specifically, as the acidic aqueous solution, a nitric acid aqueous solution, a hydrochloric acid aqueous solution, or the like is preferably exemplified because it can be formed on the surface of the desired uneven structure. Among these, a nitric acid aqueous solution is preferable because the surface of the concavo-convex structure closer to the desired shape can be formed.
The electrochemical surface roughening treatment is preferably a treatment using an alternating current from the viewpoint of the uniformity of electrolysis (surface shape).
Hereinafter, the electrochemical surface roughening treatment including the specific electrolytic surface roughening treatment will be described in detail.

As the electrochemical surface roughening treatment, it is preferable to perform the first and second electrolytic treatments with an alternating waveform current in an acidic solution before and after the cathodic electrolysis treatment. By cathodic electrolysis, hydrogen gas is generated on the surface of the aluminum plate and smut is generated to make the surface state uniform, and uniform electrochemical roughening is possible during subsequent electrolysis with alternating waveform current It becomes.
This electrochemical surface roughening treatment can be performed according to, for example, an 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. U.S. Pat. No. 4,023,637, JP-A-56-123400, JP-A-57-59770, JP-A-53-12738, JP-A-53. -32821, JP-A 53-32822, JP-A 53-32823, JP-A 55-122896, JP-A 55-13284, JP-A 62-127500, 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- Nos. 149135 and 54-146234 can be used.

  As an acidic solution which is an electrolytic solution, in addition to nitric acid and hydrochloric acid, U.S. Pat. Nos. 4,671,859, 4,661,219, 4,618,405, 4,600, 482, 4,566,960, 4,566,958, 4,566,959, 4,416,972, 4,374,710, The electrolyte solution described in each specification of 4,336,113 and 4,184,932 can also be used.

  The concentration of the acidic solution is preferably 0.5 to 2.5% by mass, but it is particularly preferably 0.7 to 2.0% by mass in consideration of use in the smut removal treatment. Moreover, it is preferable that liquid temperature is 20-80 degreeC, and it is more preferable that it is 30-60 degreeC.

  An aqueous solution mainly composed of hydrochloric acid or nitric acid is an aqueous solution of hydrochloric acid or nitric acid having a concentration of 1 to 100 g / L, such as nitric acid compounds having nitrate ions such as aluminum nitrate, sodium nitrate, ammonium nitrate, or aluminum chloride, sodium chloride, ammonium chloride, etc. At least one of the hydrochloric acid compounds having hydrochloric acid ions can be used by adding 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 aqueous solution which has hydrochloric acid or nitric acid as a main component. Preferably, a solution obtained by adding aluminum chloride, aluminum nitrate or the like to an aqueous solution of hydrochloric acid or nitric acid having a concentration of 0.5 to 2% by mass so that aluminum ions are 3 to 50 g / L is preferably used.

Further, by adding and using a compound capable of forming a complex with Cu, uniform graining is possible even for an aluminum plate containing a large amount of Cu. Examples of the compound capable of forming a complex with Cu include ammonia; hydrogen atom of ammonia such as methylamine, ethylamine, dimethylamine, diethylamine, trimethylamine, cyclohexylamine, triethanolamine, triisopropanolamine, EDTA (ethylenediaminetetraacetic acid), etc. And amines obtained by substituting with a hydrocarbon group (aliphatic, aromatic, etc.); metal carbonates such as sodium carbonate, potassium carbonate, potassium hydrogen carbonate and the like. In addition, ammonium salts such as ammonium nitrate, ammonium chloride, ammonium sulfate, ammonium phosphate, and ammonium carbonate are also included.
The temperature is preferably 10-60 ° C, more preferably 20-50 ° C.

  The AC power supply wave used for the electrochemical surface roughening treatment is not particularly limited, and a sine wave, a rectangular wave, a trapezoidal wave, a triangular wave or the like is used, but a rectangular wave or a trapezoidal wave is preferable, and a trapezoidal wave is particularly preferable. A trapezoidal wave means what was shown in FIG. In this trapezoidal wave, the time (TP) until the current reaches a peak from zero is preferably 1 to 3 msec. If it is less than 1 msec, processing irregularities such as chatter marks that occur perpendicular to the traveling direction of the aluminum plate are likely to occur. When TP exceeds 3 msec, especially when a nitric acid electrolyte is used, it is easily affected by trace components in the electrolyte typified by ammonium ions and the like that spontaneously increase by electrolytic treatment, and uniform graining is performed. It becomes hard to be broken. As a result, the stain resistance tends to decrease when a lithographic printing plate is obtained.

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

  One or more AC power supplies can be connected to the electrolytic cell. As shown in FIG. 3, the current ratio between the AC anode and cathode applied to the aluminum plate facing the main electrode is controlled to achieve uniform graining and to dissolve the carbon of the main electrode. In addition, it is preferable to install an auxiliary anode and divert part of the alternating current. In FIG. 3, 11 is an aluminum plate, 12 is a radial drum roller, 13a and 13b are main poles, 14 is an electrolytic treatment liquid, 15 is an electrolytic solution supply port, and 16 is a slit. , 17 is an electrolyte passage, 18 is an auxiliary anode, 19a and 19b are thyristors, 20 is an AC power source, 40 is a main electrolytic cell, and 50 is an auxiliary anode cell. An anodic reaction that acts on the aluminum plate facing the main electrode by diverting a part of the current value as a direct current to an auxiliary anode provided in a tank separate from the two main electrodes via a rectifier or switching element It is possible to control the ratio between the current value for the current and the current value for the cathode reaction. On the aluminum plate facing the main electrode, the ratio of the amount of electricity involved in the anodic reaction and the cathodic reaction (the amount of electricity at the time of cathode / the amount of electricity at the time of anode) is preferably 0.3 to 0.95.

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

(Nitric acid electrolysis)
Fine irregularities (pits) can be formed on the surface by electrochemical surface roughening using an electrolytic solution mainly composed of nitric acid.
The fine irregularities have an average opening diameter of 0.1 to 5 μm and are uniformly generated on the entire surface of the aluminum plate. To obtain such a grain, the total amount of electricity furnished to anode reaction on the aluminum plate up until the electrolysis reaction is completed is preferably from ^{1~1000C / dm 2, 50~300C / dm} 2 It is more preferable that The current density at this time is preferably ²⁰ to 100 A / dm ² .

(Hydrochloric acid electrolysis)
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 finer irregularities have an average opening diameter of 0.01 to 0.2 μm and are uniformly generated on the entire surface of the aluminum plate. Such grained total amount of electricity furnished to anode reaction on the aluminum plate up until the electrolysis reaction is completed in order to obtain the, is preferably from 1~100C / dm ^2, in 20~70C / dm ² More preferably. The current density at this time is preferably ²⁰ to 50 A / dm ² .

In such an electrochemical surface roughening treatment with an electrolyte mainly composed of hydrochloric acid, a large crater-like swell is simultaneously formed by increasing the total amount of electricity involved in the anode reaction to 400 to 1000 C / dm ^2. In this case, fine irregularities having an average opening diameter of 0.01 to 0.4 μm are formed on the entire surface by being superimposed on a crater-like wave having an average opening diameter of 10 to 30 μm.

  In the present invention, as the first electrochemical surface roughening treatment, the electrochemical surface roughening treatment (nitric acid electrolysis) using the above-described electrolyte mainly composed of nitric acid is performed, and the second electrochemical surface roughening treatment is performed. As the surface treatment, it is preferable to perform the electrochemical surface roughening treatment (hydrochloric acid electrolysis) using the above-described electrolyte mainly composed of hydrochloric acid. Moreover, in this invention, when performing nitric acid electrolysis and hydrochloric acid electrolysis in such an order, it is preferable that nitric acid electrolysis is the said specific electrolytic surface roughening process. That is, as the first electrochemical surface roughening treatment, an electrochemical surface roughening treatment using an alternating current in an acidic aqueous solution containing 0.1 to 3.0% by mass of Cu is performed. As the electrochemical surface roughening treatment, the above hydrochloric acid electrolysis is preferably performed.

The aluminum plate is preferably subjected to cathodic electrolysis during the first and second electrochemical surface roughening treatments performed in an electrolytic solution such as nitric acid or hydrochloric acid. By this cathodic electrolysis treatment, smut is generated on the surface of the aluminum plate, and hydrogen gas is generated to enable a more uniform electrochemical surface roughening treatment. This cathodic electrolysis treatment is carried out in an acidic solution at a cathode electric quantity of preferably 3 to 80 C / dm ² , more preferably 5 to 30 C / dm ² . If the amount of cathodic electricity is less than 3 C / dm ² , the amount of smut adhesion may be insufficient, and if it exceeds 80 C / dm ² , the amount of smut adhesion may be excessive. Further, the electrolytic solution may be the same as or different from the solution used in the first and second electrochemical roughening treatments.

Next, the specific electrolytic surface roughening treatment will be described in detail.
In the present invention, the specific electrolytic surface roughening treatment is an electrochemical surface roughening treatment performed in an acidic aqueous solution containing 0.1 to 3.0% by mass of Cu. From the viewpoint of the concentration at which the electrolytic change effect can be obtained, that is, the concentration at which the pit uniformity can be maintained / improved and the diameter adjusting effect can be obtained, the Cu content is set to a lower limit of 0.1% by mass. It is preferable that it is at least mass%. On the other hand, from the viewpoint of pit uniformity, the upper limit is 3.0% by mass, preferably 2.5% by mass or less, and more preferably 1.5% by mass or less.

  Moreover, in this invention, the method of making Cu contain in acidic aqueous solution uses the compound containing copper, such as metallic copper or copper oxide, cuprous chloride, cupric chloride, copper sulfate, copper acetate. it can. Among these, from the viewpoint of solubility, when the acidic aqueous solution is an aqueous nitric acid solution, it is preferable to use copper nitrate, and when the acidic aqueous solution is an aqueous hydrochloric acid solution, it is preferable to use cuprous chloride and cupric chloride. .

  The size of the pits formed by performing the specific electrolytic surface roughening treatment is not particularly limited because it varies depending on the type of the acidic aqueous solution and the presence or absence of the mechanical surface roughening treatment or alkali etching treatment. For example, when a specific electrolytic surface roughening treatment using an aqueous nitric acid solution as an acidic aqueous solution is performed after the mechanical surface roughening treatment, the pit diameter of pits formed by nitric acid electrolysis not containing copper is 0.5. The pit diameter can be increased to about 2 to 3 μm while it is about ˜1 μm.

  In the present invention, by performing such a specific electrolytic surface-roughening treatment, stain resistance and printing durability when a lithographic printing plate precursor using the obtained lithographic printing plate support is used as a lithographic printing plate are obtained. Both are excellent. The reason why this stain resistance and printing durability are excellent is not clear in detail, but it is possible to form pits larger in size than pits formed by electrochemical surface roughening treatment containing no Cu, and This is probably because non-uniform and locally deep pits are not formed.

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

  Alkaline etching performed before the electrochemical surface roughening treatment, when the mechanical surface roughening treatment is not performed, rolling oil on the surface of the aluminum plate (rolled aluminum), dirt, natural oxide film, etc. For the purpose of removing the surface, and when the mechanical surface roughening treatment has already been performed, the edge portion of the unevenness generated by the mechanical surface roughening treatment is dissolved to change the surface to a surface with reduced steepness. It is done for the purpose.

If you do not mechanical surface-roughening treatment before the alkali etching treatment, the etching amount is preferably from 0.1 to 10 g / m ^2, and more preferably 1 to 5 g / m ^2. If the etching amount is less than 0.1 g / m ² , rolling oil, dirt, natural oxide film, etc. may remain on the surface, so uniform pits cannot be generated in the subsequent electrochemical roughening treatment. Unevenness may occur. On the other hand, when the etching amount is 1 to 10 g / m ² , the surface rolling oil, dirt, natural oxide film and the like are sufficiently removed. An etching amount exceeding the above range is economically disadvantageous.

When performing mechanical surface-roughening treatment before the alkali etching treatment, the etching amount is preferably from 3 to 20 g / m ^2, and more preferably 5 to 15 g / m ^2. When the etching amount is 3 g / m ² or more, the unevenness formed by the mechanical surface roughening treatment can be appropriately smoothed, and uniform in the electrochemical chemical surface roughening treatment performed thereafter. It becomes easy to form pits, and as a result, stain resistance as a lithographic printing plate is further improved.

Alkaline etching treatment performed immediately after the electrochemical surface roughening treatment is performed by dissolving the smut formed in the acidic electrolyte and dissolving the edge portion of the pit formed by the electrochemical surface roughening treatment. The purpose is to reduce the degree.
Since the pits formed by the electrochemical surface roughening process differ depending on the type of the electrolytic solution, the optimum etching amount also varies. However, the etching amount of the alkali etching process performed after the electrochemical surface roughening process is 0.1. It is preferably ˜5 g / m ² . When a nitric acid electrolyte is used, the etching amount needs to be set larger than when a hydrochloric acid electrolyte is used.
When the electrochemical surface roughening treatment is performed a plurality of times, an alkali etching treatment can be performed as necessary after each treatment.

  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.

  Although the density | concentration of an alkaline solution can be determined according to the etching amount, it is preferable that it is 1-50 mass%, and it is more preferable that it is 10-35 mass%. When aluminum ions are dissolved in the alkaline solution, the concentration of aluminum ions is preferably 0.01 to 10% by mass, and more preferably 3 to 8% by mass. The temperature of the alkaline solution is preferably 20 to 90 ° C. The treatment time is preferably 1 to 120 seconds.

  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.

<Desmut treatment>
After the electrochemical surface roughening treatment or the alkali etching treatment, pickling (desmut treatment) is preferably performed in order to remove dirt (smut) remaining on the surface. Examples of the acid used include nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, and borohydrofluoric acid.
The desmutting treatment is performed, for example, by bringing the aluminum plate into contact with an acidic solution having a concentration of 0.5 to 30% by mass (containing 0.01 to 5% by mass of aluminum ions) such as hydrochloric acid, nitric acid, and sulfuric acid. . 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.
In the desmutting treatment, as an acidic solution, a waste solution of an aqueous solution mainly containing nitric acid or an aqueous solution mainly containing hydrochloric acid discharged in the electrochemical surface roughening treatment described above, or sulfuric acid discharged in an anodic oxidation treatment described later A waste solution of an aqueous solution mainly composed of can be used.
It is preferable that the liquid temperature of a desmut process is 25-90 degreeC. Moreover, it is preferable that processing time is 1-180 second. Aluminum and aluminum alloy components may be dissolved in the acidic solution used for the desmut treatment.

<Anodizing treatment>
In the present invention, it is preferable to further anodize the aluminum plate treated as described above. 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), and the aluminum ion concentration is 1 to 25 g / L (0.1 to 2.5% by mass). It is preferable that it is 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.

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 where continuous anodizing treatment is performed, a low current of 5 to 10 A / m ² is initially introduced so that current is concentrated on a part of the aluminum plate and so-called “burning” does not occur. It is preferable to increase the current density to 30 to 50 A / dm ² or more as the current is passed at the density and the anodization process proceeds.
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 the electrolysis apparatus used for the anodizing treatment, those described in JP-A-48-26638, JP-A-47-18739, JP-B-58-24517, and the like 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, the aluminum plate 416 is transported as indicated by arrows in FIG. In the power supply tank 412 in which the electrolytic solution 418 is stored, the aluminum plate 416 is charged to (+) by the power supply electrode 420. The aluminum plate 416 is transported upward by the roller 422 in the power supply tank 412, and the direction is changed downward by the nip roller 424, and then transported toward the electrolytic treatment tank 414 in which the electrolytic solution 426 is stored. The direction is changed horizontally. Next, the aluminum plate 416 is charged to (−) by the electrolytic electrode 430 to form an anodized film on the surface thereof, and the aluminum plate 416 exiting the electrolytic treatment tank 414 is conveyed to a subsequent process. In the anodizing apparatus 410, the roller 422, the nip roller 424, and the roller 428 constitute a direction changing means. By 428, it is conveyed into a mountain shape and an inverted U shape. The feeding electrode 420 and the electrolytic electrode 430 are connected to a DC power source 434.

  A feature of the anodizing apparatus 410 in FIG. 4 is that the feeding tank 412 and the electrolytic treatment tank 414 are partitioned by a single tank wall 432, and the aluminum plate 416 is conveyed in a mountain shape and an inverted U shape between the tanks. It is in. As a result, the length of the aluminum plate 416 in the inter-tank portion can be minimized. Therefore, the overall length of the anodizing apparatus 410 can be shortened, so that the equipment cost can be reduced. In addition, by conveying the aluminum plate 416 in a mountain shape and an inverted U shape, it is not necessary to form an opening for allowing the aluminum plate 416 to pass through the tank walls of the tanks 412 and 414. Therefore, since the liquid feeding amount required to maintain the liquid level height in each tank 412 and 414 at a required level can be suppressed, the operating cost can be reduced.

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

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

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

Hydrophilization treatment with an aqueous solution of an alkali metal silicate such as sodium silicate and potassium silicate is described in US Pat. No. 2,714,066 and US Pat. No. 3,181,461. It can be performed according to methods and procedures.
Examples of the alkali metal silicate include sodium silicate, potassium silicate, and lithium silicate. The aqueous solution of alkali metal silicate may contain an appropriate amount of sodium hydroxide, potassium hydroxide, lithium hydroxide or the like.
The aqueous solution of alkali metal silicate may contain an alkaline earth metal salt or a Group 4 (Group IVA) metal salt. Examples of the alkaline earth metal salt include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate; sulfates; hydrochlorides; phosphates; acetates; oxalates; Examples of the Group 4 (Group IVA) metal salt include titanium tetrachloride, titanium trichloride, potassium fluoride titanium, potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride. And zirconium tetrachloride. These alkaline earth metal salts and Group 4 (Group IVA) metal salts are used alone or in combination of two or more.

The amount of Si adsorbed by the alkali metal silicate treatment can be measured with a fluorescent X-ray analyzer, and the amount of adsorption is preferably about 1.0 to 15.0 mg / m ² .
By this alkali metal silicate treatment, the effect of improving the dissolution resistance to the alkaline developer on the surface of the lithographic printing plate support is obtained, the dissolution of the aluminum component into the developer is suppressed, and the developer fatigue It is possible to reduce the occurrence of development residue due to the above.

The hydrophilization treatment by forming a hydrophilic undercoat layer can also be performed according to the conditions and procedures described in JP-A Nos. 59-101651 and 60-149491.
Examples of the hydrophilic vinyl polymer used in this method include polyvinyl sulfonic acid, sulfo group-containing vinyl polymerizable compounds such as p-styrene sulfonic acid having a sulfo group, and ordinary vinyl polymerization such as (meth) acrylic acid alkyl ester. And a copolymer with a functional compound. Examples of hydrophilic compounds that may be used in this method include, -NH ₂ group, compounds having at least one selected from the group consisting of -COOH group and sulfo group.

<Washing treatment>
In the present invention, it is preferable to carry out water washing after completion of the above-described processes. For washing with water, pure water, well water, tap water, or the like can be used, and water containing Ca is preferably used. Further, a nip device may be used to prevent the processing liquid from being brought into the next process.

<Dry>
In the present invention, after obtaining the lithographic printing plate support as described above, it is preferable to dry the surface of the lithographic printing plate support before providing the image recording layer. Drying is preferably performed after the final treatment of the surface treatment, after washing with water and draining with a nip roller.
The drying temperature is preferably 70 ° C or higher, more preferably 80 ° C or higher, preferably 110 ° C or lower, more preferably 100 ° C or lower.
The drying time is preferably 1 second or longer, more preferably 2 seconds or longer, more preferably 20 seconds or shorter, and even more preferably 15 seconds.

The support for a lithographic printing plate obtained by performing such a treatment has a back surface (side on which no image recording layer is provided) so that the image recording layer is not damaged even if it is overlaid when used as a lithographic printing plate precursor. If necessary, a coating layer made of an organic polymer compound (hereinafter also referred to as “back coat layer”) may be provided on the surface.
As a main component of the back coat layer, at least one resin selected from the group consisting of a saturated copolymerized polyester resin, a phenoxy resin, a polyvinyl acetal resin, and a vinylidene chloride copolymer resin having a glass transition point of 20 ° C. or higher is used. Is preferred.

  The saturated copolyester resin is composed of a dicarboxylic acid unit and a diol unit. Examples of the dicarboxylic acid unit include aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, tetrabromophthalic acid, and tetrachlorophthalic acid; adipic acid, azelaic acid, succinic acid, oxalic acid, suberic acid, and sebacic acid , Saturated aliphatic dicarboxylic acids such as malonic acid and 1,4-cyclohexanedicarboxylic acid.

  The backcoat layer further comprises a dye or pigment for coloring, a silane coupling agent for improving the adhesion to the support, a diazo resin comprising a diazonium salt, an organic phosphonic acid, an organic phosphoric acid, a cationic polymer, Wax, higher fatty acids, higher fatty acid amides, silicone compounds composed of dimethylsiloxane, modified dimethylsiloxane, polyethylene powder and the like that are usually used as slipping agents can be appropriately contained.

  The thickness of the backcoat layer may be basically such that even if no interleaf is present, the image recording layer to be described later is hardly damaged, and is preferably 0.01 to 8 μm. When the thickness is less than 0.01 μm, it is difficult to prevent the recording layer from being scratched when the planographic printing plate precursors are handled in layers. On the other hand, when the thickness exceeds 8 μm, the backcoat layer swells due to chemicals used around the lithographic printing plate during printing, the thickness varies, and the printing pressure may change to deteriorate the printing characteristics.

  Various methods can be used as a method of providing the back coat layer on the back surface of the support. For example, a method in which the above components for the back coat layer are dissolved in an appropriate solvent and applied as a solution, or an emulsified dispersion is applied and dried; a previously formed film is supported with an adhesive or heat. The method of bonding to a body; The method of forming a molten film with a melt extruder and bonding to a support body is mentioned. The most preferable method for securing a suitable thickness is a method in which the components for the backcoat layer are dissolved in a suitable solvent, applied as a solution, and dried. In this method, an organic solvent as described in JP-A-62-251739 can be used alone or in combination as a solvent.

  In the production of a lithographic printing plate precursor, any one of the back-coat layer on the back surface, the intermediate layer on the front surface, and the image recording layer may be provided on the support first, or both may be provided simultaneously.

[Lithographic printing plate precursor]
The support for a lithographic printing plate obtained according to the present invention can be provided with an image recording layer after providing an intermediate layer as desired to form a lithographic printing plate precursor.
Hereinafter, the intermediate layer and the image recording layer will be described in detail.

<Intermediate layer>
The intermediate layer provided as desired is preferably formed using a polymer compound containing a component having an acid group and a component having an onium group. The lithographic printing plate precursor obtained by forming an intermediate layer using the polymer compound on the lithographic printing plate support described above has printing durability and stain resistance (anti-stain resistance, erasure resistance). (Dirty property) becomes better.
The polymer compound is formed, for example, by polymerizing at least a monomer having an acid group and a monomer having an onium group. Hereinafter, this polymer compound will be described in detail.

The acid group is preferably an acid group having an acid dissociation index (pKa) of 7 or less, more preferably —COOH, —SO ₃ H, —OSO ₃ H, —PO ₃ H ₂ , —OPO ₃ H ₂ , —CONHSO. ₂ , —SO ₂ NHSO ₂ —, particularly preferably —COOH.
Moreover, what is preferable as an onium group is an onium group containing an atom of Group 15 (Group VA) or Group 16 (Group VIA) of the periodic table, more preferably a nitrogen atom, a phosphorus atom or a sulfur atom. Particularly preferred is an onium group containing a nitrogen atom.

The polymer compound is preferably a vinyl polymer such as an acrylic resin, a methacrylic resin or polystyrene, a urethane resin, a polyester or a polyamide, and a vinyl polymer such as an acrylic resin, a methacrylic resin or polystyrene. It is preferably a polymer compound characterized by being.
The monomer having an acid group is preferably a compound represented by the following general formula (1) or general formula (2). Similarly, the monomer having an onium group is represented by the following general formula (3), It is preferable that it is a compound represented by Formula (4) or General formula (5).

In the formula, A represents a divalent linking group. B represents an aromatic group or a substituted aromatic group. D and E each independently represent a divalent linking group. G represents a trivalent linking group. X and X ′ each independently represents an acid group having a pKa of 7 or less, or an alkali metal salt or ammonium salt thereof. R ₁ represents a hydrogen atom, an alkyl group or a halogen atom. a, b, d and e each independently represents 0 or 1; t is an integer of 1 to 3.

More preferably among the monomers having an acid group, A represents —COO— or —CONH—, B represents a phenylene group or a substituted phenylene group, and the substituent is a hydroxyl group, a halogen atom or an alkyl group. D and E each independently represent an alkylene group or a divalent linking group having a molecular formula of C _n H _2n O, C _n H _2n S or C _n H _{2n + 1} N. G represents a trivalent connecting group molecular formula is represented by _{C n H 2n-1, C} n H 2n-1 O, C n H 2n-1 S or C _n H _2n N. However, n represents the integer of 1-12 here. X and X ′ each independently represent a carboxylic acid, a sulfonic acid, a phosphonic acid, a sulfuric monoester or a phosphoric monoester. R ₁ represents a hydrogen atom or an alkyl group. a, b, d and e each independently represent 0 or 1, but a and b are not 0 at the same time. Among the monomers having an acid group, a compound represented by the general formula (1) is particularly preferable, and B represents a phenylene group or a substituted phenylene group, and the substituent is a hydroxyl group or an alkyl group having 1 to 3 carbon atoms. D and E each independently represent an alkylene group having 1 to 2 carbon atoms or an alkylene group having 1 to 2 carbon atoms linked by an oxygen atom. R ₁ represents a hydrogen atom or an alkyl group. X represents a carboxylic acid group. a is 0 and b is 1.

Specific examples of the monomer having an acid group are shown below. However, the present invention is not limited to this specific example.
(Specific examples of monomers having acid groups)
Acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, itaconic acid, maleic acid, maleic anhydride

  Next, a polymer represented by the following general formula (3), (4) or (5), which is a monomer having an onium group, will be described.

In the formula, J represents a divalent linking group. K represents an aromatic group or a substituted aromatic group. M independently represents a divalent linking group. Y ₁ represents an atom of the periodic table 15 group (Group VA), and Y ₂ represents an atom of the periodic table group 16 (Group VIA). Z ⁻ represents a counter anion. R ₂ represents a hydrogen atom, an alkyl group or a halogen atom. R ₃ , R ₄ , R ₅ and R ₇ each independently represents a hydrogen atom or, optionally, an alkyl group, aromatic group or aralkyl group to which a substituent may be bonded, and R ₆ represents an alkylidine group or a substituted group. Although it represents alkylidine, R ₃ and R ₄ or R ₆ and R ₇ may be bonded to each other to form a ring. j, k and m each independently represents 0 or 1; u represents an integer of 1 to 3.

More preferably among the monomers having an onium group, J represents —COO— or —CONH—, K represents a phenylene group or a substituted phenylene group, and the substituent is a hydroxyl group, a halogen atom or an alkyl group. M represents an alkylene group or a divalent linking group having a molecular formula of C _n H _2n O, C _n H _2n S, or C _n H _{2n + 1} N. However, n represents the integer of 1-12 here. Y ₁ represents a nitrogen atom or a phosphorus atom, and Y ₂ represents a sulfur atom. Z ⁻ represents a halogen ion, PF ₆ ⁻ , BF ₄ ⁻ or R ₈ SO ₃ ⁻ . R ₂ represents a hydrogen atom or an alkyl group. R ₃ , R ₄ , R ₅ and R ₇ each independently represent a hydrogen atom or, optionally, a C 1-10 alkyl group, aromatic group or aralkyl group to which a substituent may be bonded; ₆ represents an alkylidine group having 1 to 10 carbon atoms or a substituted alkylidine, but R ₃ and R ₄ , and R ₆ and R ₇ may be bonded to each other to form a ring. j, k and m each independently represent 0 or 1, but j and k are not 0 at the same time. R ₈ represents a C 1-10 alkyl group, aromatic group or aralkyl group to which a substituent may be bonded.

More preferably among monomers having an onium group, K represents a phenylene group or a substituted phenylene group, and the substituent is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. M represents an alkylene group having 1 to 2 carbon atoms or an alkylene group having 1 to 2 carbon atoms linked by an oxygen atom. Z ⁻ represents a chlorine ion or R ₈ SO ₃ ^— . R ₂ represents a hydrogen atom or a methyl group. j is 0 and k is 1. R ₈ represents an alkyl group having 1 to 3 carbon atoms.

Specific examples of the monomer having an onium group are shown below. However, the present invention is not limited to this specific example.
(Specific examples of monomers having an onium group)

Monomers having an acid group may be used alone or in combination of two or more, and monomers having an onium group may be used alone or in combination of two or more. Furthermore, the polymer compound may be used by mixing two or more monomers, different composition ratios or molecular weights.
The polymer compound preferably contains 60 to 80 mol%, more preferably 65 to 75 mol% of a component having an acid group. Moreover, it is preferable to contain 20-40 mol% of the structural component which has an onium group, and it is more preferable to contain 25-35 mol%.
When the polymer contains the constituent component having an acid group and the constituent component having an onium group in the above range, the obtained lithographic printing plate precursor is further improved in printing durability.

  In addition, the structural component which has an acid group may be used independently or may be used in combination of 2 or more types, and the monomer which has onium group may be used independently or may be used in combination of 2 or more types. Furthermore, the polymer compound may be used by mixing two or more monomers, different composition ratios or molecular weights.

Furthermore, these polymer compounds may contain at least one selected from the polymerizable monomers shown in the following (1) to (14) as a copolymerization component.
(1) N- (4-hydroxyphenyl) acrylamide or N- (4-hydroxyphenyl) methacrylamide, o-, m- or p-hydroxystyrene, o- or m-bromo-p-hydroxystyrene, o- or Acrylamides, methacrylamides, acrylates, methacrylates and bidroxystyrenes having an aromatic hydroxyl group such as m-chloro-p-hydroxystyrene, o-, m- or p-hydroxyphenyl acrylate or methacrylate ,
(2) unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride and its half ester, itaconic acid, itaconic anhydride and its half ester,

  (3) N- (o-aminosulfonylphenyl) acrylamide, N- (m-aminosulfonylphenyl) acrylamide, N- (p-aminosulfonylphenyl) acrylamide, N- [1- (3-aminosulfonyl) naphthyl] acrylamide Acrylamides such as N- (2-aminosulfonylethyl) acrylamide, N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) methacryl Amides, methacrylamides such as N- [1- (3-aminosulfonyl) naphthyl] methacrylamide, N- (2-aminosulfonylethyl) methacrylamide, o-aminosulfonylphenyl acrylate, m-aminosulfonylphenyl Unsaturated sulfonamides such as acrylic acid esters such as acrylate, p-aminosulfonylphenyl acrylate, 1- (3-aminosulfonylphenylnaphthyl) acrylate, o-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate, p-amino Unsaturated sulfonamides such as sulfonylphenyl methacrylate and methacrylates such as 1- (3-aminosulfonylphenylnaphthyl) methacrylate,

(4) phenylsulfonylacrylamide, which may have a substituent such as tosylacrylamide, and phenylsulfonylmethacrylamide, which may have a substituent such as tosylmethacrylamide;
(5) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group, such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate,
(6) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, (Substituted) acrylic acid esters such as 4-hydroxybutyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate,
(7) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, (Substituted) methacrylate esters such as 4-hydroxybutyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl methacrylate,

(8) Acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-ethyl acrylamide, N-ethyl methacrylamide, N-hexyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-cyclohexyl methacryl Amide, N-hydroxyethyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N-phenyl methacrylamide, N-benzyl acrylamide, N-benzyl methacrylamide, N-nitrophenyl acrylamide, N-nitrophenyl methacrylamide, N Acrylamide or methacrylamide such as ethyl-N-phenylacrylamide and N-ethyl-N-phenylmethacrylamide
(9) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether,

(10) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate,
(11) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene,
(12) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, phenyl vinyl ketone,
(13) Olefins such as ethylene, propylene, isobutylene, butadiene, isoprene,
(14) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile and the like.

  Next, typical examples of the polymer compound are shown below. The composition ratio of the polymer structure represents a mole percentage.

  The polymer compound can be generally produced by using a radical chain polymerization method (see “Textbook of Polymer Science” 3rd ed. (1984) FW Billmeyer, A Wiley-Interscience Publication).

The molecular weight of the polymer compound may be in a wide range, but when measured using a light scattering method, the weight average molecular weight (M _w ) is preferably 500 to 2,000,000, preferably 1,000 to More preferably, it is in the range of 600,000. Further, the number average molecular weight (M _n ) calculated from the integrated intensity of the terminal group and the side chain functional group in NMR measurement is preferably 300 to 500,000, and is preferably in the range of 500 to 100,000. More preferred. If the molecular weight is smaller than the above range, the adhesion to the substrate is weakened and printing durability may be deteriorated. On the other hand, when the molecular weight exceeds the above range, the adhesion to the support becomes too strong, and the photosensitive layer residue in the non-image area may not be sufficiently removed. The amount of the unreacted monomer contained in the polymer may be in a wide range, but is preferably 20% by mass or less, more preferably 10% by mass or less.

A polymer compound having a molecular weight in the above range can be obtained by using a polymerization initiator and a chain transfer agent together and adjusting the addition amount when the corresponding monomer is copolymerized. The chain transfer agent refers to a substance that moves the active site of the reaction by a chain transfer reaction in a polymerization reaction, and the ease of the transfer reaction is represented by a chain transfer constant Cs. The chain transfer constant Cs × 10 ⁴ (60 ° C.) of the chain transfer agent used in the present invention is preferably 0.01 or more, more preferably 0.1 or more, and particularly preferably 1 or more. preferable. As the polymerization initiator, peroxides, azo compounds, and redox initiators that are commonly used in radical polymerization can be used as they are. Of these, azo compounds are particularly preferred.

Specific examples of the chain transfer agent include halogen compounds such as carbon tetrachloride and carbon tetrabromide, alcohols such as isopropyl alcohol and isobutyl alcohol, 2-methyl-1-butene, 2,4-diphenyl-4-methyl- Olefins such as 1-pentene, ethanethiol, butanethiol, dodecanethiol, mercaptoethanol, mercaptopropanol, methyl mercaptopropionate, ethyl mercaptopropionate, mercaptopropionic acid, thioglycolic acid, ethyl disulfide, sec-butyl disulfide, 2 -Sulfur-containing compounds such as hydroxyethyl disulfide, thiosalicylic acid, thiophenol, thiocresol, benzyl mercaptan, phenethyl mercaptan and the like are exemplified, but not limited thereto.
More preferably, ethanethiol, butanethiol, dodecanethiol, mercaptoethanol, mercaptopropanol, methyl mercaptopropionate, ethyl mercaptopropionate, mercaptopropionic acid, thioglycolic acid, ethyl disulfide, sec-butyl disulfide, 2-hydroxyethyl disulfide Thiosalicylic acid, thiophenol, thiocresol, benzyl mercaptan, phenethyl mercaptan, particularly preferably ethanethiol, butanethiol, dodecanethiol, mercaptoethanol, mercaptopropanol, methyl mercaptopropionate, ethyl mercaptopropionate, mercaptopropionic acid Thioglycolic acid, ethyl disulfide, sec-butyl disulfide, 2-hydride Carboxymethyl ethyl disulfide.

  The amount of the unreacted monomer contained in the polymer may be in a wide range, but is preferably 20% by mass or less, and more preferably 10% by mass or less.

<Formation of intermediate layer>
The intermediate layer can be provided by applying the coating solution (intermediate layer forming coating solution) in which the above-described components of the intermediate layer are dissolved on the lithographic printing plate support described above by various methods. Although there is no restriction | limiting in particular in the method of apply | coating an intermediate | middle layer, The following method is mentioned as a typical thing. That is, (1) A solution in which the specific polymer in the present invention is dissolved in an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof, or a mixed solvent of these organic solvent and water is applied onto a support. A coating method provided by drying. Alternatively, (2) the support is immersed in a solution in which the specific polymer in the present invention is dissolved in an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof, or a mixed solvent of these organic solvents and water. Thereafter, a coating method in which the intermediate layer is formed by washing and drying with water or air or the like can be mentioned.

  In the application method (1), a solution having a concentration of 0.005 to 10% by mass in total for the above compounds may be applied by various methods. As the coating means, any means such as bar coater coating, spin coating, spray coating, curtain coating, etc. may be used. In the coating method (2), the concentration of the solution is 0.005 to 20% by mass, preferably 0.01 to 10% by mass, and the immersion temperature is 0 to 70 ° C., preferably 5 to 60 ° C. The soaking time is 0.1 to 5 minutes, preferably 0.5 to 120 seconds.

  The above intermediate layer forming coating solution includes basic substances such as ammonia, triethylamine and potassium hydroxide, inorganic acids such as hydrochloric acid, phosphoric acid, sulfuric acid and nitric acid, organic sulfonic acids such as nitrobenzenesulfonic acid and naphthalenesulfonic acid, PH is adjusted with organic phosphonic acids such as phenylphosphonic acid, organic acidic substances such as organic carboxylic acids such as benzoic acid, coumaric acid and malic acid, naphthalenesulfonyl chloride, organic chlorides such as benzenesulfonyl chloride, etc., pH 0-12, More preferably, it can also be used in the range of pH 0-6. In addition, a substance that absorbs ultraviolet light, visible light, infrared light, or the like can be added to the coating solution for forming an intermediate layer in order to improve the tone reproducibility of the lithographic printing plate.

The total coating amount of the intermediate layer in the present invention after drying is appropriately 1 to 100 mg / m ² , and preferably ² to 70 mg / m ² .
By providing the intermediate layer described above, the lithographic printing plate precursor according to the present invention is also capable of entanglement stain resistance, erasure stain resistance, neglected stain resistance, and printing durability even when an FM screen is used for halftone dots. It will be excellent.

The operation of the intermediate layer used in the present invention is not clear, but when the image recording layer is removed using an erasing liquid, the interaction between the intermediate layer and the aluminum plate is weakened, and the intermediate layer can be easily removed. it is conceivable that.
In general, an image recording layer (thermal positive type image recording layer) containing an alkali-soluble polymer compound and a photothermal conversion substance, which will be described later, is near the support surface due to thermal diffusion to the support during exposure. In some cases, the removal of the image recording layer in the non-image area may be incomplete, but in the present invention, the polymer used for the intermediate layer has good removability by the developer, When a positive type image recording layer is provided, the non-image area is treated with an aqueous solution containing an alkali metal salt having a pH of 11.5 to 13.0, and the aluminum content is 3.0 to 15.0 mg / m ² Since the plate is exposed, it is considered that the occurrence of entangled dirt is effectively suppressed.

<Image recording layer>
The support for a lithographic printing plate obtained according to the present invention can be provided with an image recording layer after providing an intermediate layer as desired to form a lithographic printing plate precursor. A photosensitive composition is used for the image recording layer.

  A photosensitive composition is used for the image recording layer. The photosensitive composition suitably used in the present invention is not particularly limited. For example, a thermal positive photosensitive composition containing an alkali-soluble polymer compound and a photothermal conversion substance (hereinafter referred to as this composition and the composition). The image recording layer was referred to as “thermal positive type”), a thermal negative photosensitive composition containing a curable compound and a photothermal conversion substance (hereinafter also referred to as “thermal negative type”), and photopolymerization type photosensitive. Composition (hereinafter also referred to as “photopolymer type”), negative photosensitive composition containing diazo resin or photocrosslinking resin (hereinafter also referred to as “conventional negative type”), positive containing quinonediazide compound Type photosensitive composition (hereinafter also referred to as "conventional positive type"), photosensitive composition that does not require a special development step (Referred to below as "non-treatment type".) And the like.

Also, as a thermal positive type, a thermal negative type, etc., the digitized image information is carried on a high-convergence radiation such as a laser beam, and the lithographic printing plate precursor is scanned and exposed with the light, via a lith film. Without any problem, it is preferably used in computer-to-plate (CTP) technology for directly producing a lithographic printing plate. Therefore, an image recording layer that can be written by infrared laser exposure and used for such applications is preferable.
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 material 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 acid group in the molecule and a mixture of two or more thereof. In particular, a phenolic hydroxy group, sulfonamide group (in -SO ₂ NH-R (wherein, R represents a hydrocarbon group.)), Active imino group _{(-SO 2 NHCOR, -SO 2 NHSO} 2 R, -CONHSO A resin having an acid group such as ₂ R (wherein R has the same meaning as described above) is preferable in terms of solubility in an alkali developer.
In particular, a resin having a phenolic hydroxy group is preferable in that it has excellent image-forming properties when exposed to light such as an infrared laser. For example, phenol-formaldehyde resin, m-cresol-formaldehyde resin, p-cresol-formaldehyde resin, 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.

  In the present invention, in addition to the alkali-soluble polymer compound and the photothermal conversion substance, (a) a monomer represented by the following formula (2) (hereinafter referred to as “monomer a”), (b) ) A monomer having an aliphatic group having 7 or more carbon atoms having a bridge-like bond (hereinafter referred to as “monomer b”), (c) a monomer having an acid group (hereinafter referred to as “monomer c”). It is preferable that a high molecular compound fluorine-based polymer (hereinafter referred to as “specific copolymer”) contained as a copolymerization component is contained.

In the formula (2), Rf is a substituent containing a fluoroalkyl group or a perfluoroalkyl group having 9 or more fluorine atoms, n is 1 or 2, and R ¹ is hydrogen or a methyl group. .
The bridge-like bond refers to a bond obtained by bonding non-adjacent atoms in one ring structure in a bridging manner. When the monomer b has two or more cycloaliphatic groups, it suffices if at least one has a bridge-like bond.

In lithographic printing, when the amount of dampening water is increased during printing, a phenomenon occurs in which ink does not adhere to the image area or the image density becomes thin. Such a phenomenon is called poor inking.
However, the inclusion of the specific copolymer in the image recording layer allows the lithographic printing plate precursor to adhere ink to the image area regardless of whether the amount of dampening water supplied during printing is large or small. Meat is good. That is, the lithographic printing plate precursor of the present invention can be used in cases where the amount of dampening water is large or small by incorporating the polymer compound fluorine-based polymer in the image recording layer of the lithographic printing plate precursor of the present invention. When the FM screen is used, the entanglement stain resistance is good, and the ink deposits on the image portion is also good. That is, it becomes easier to balance water and ink during printing.

The mechanism of action of the specific copolymer is not clear, but is presumed as follows.
The specific copolymer has a tendency to be unevenly distributed due to the function of the monomer a. At that time, the functional group of the monomer b which is the second copolymer component is also oriented on the surface. Although the partial structure containing fluorine contributes to the improvement of the development resistance, there is a concern that its high oil repellency affects the fleshing property.
However, since the aliphatic group having 7 or more carbon atoms having a bridge-like bond contained in the monomer b is sterically bulky and has a relatively low affinity with a coexisting alkali-soluble resin such as a novolak resin, it is more oriented on the surface. Since this aliphatic group has a high lipophilicity, by copolymerizing the monomer b with a specific copolymer, even if the introduction amount is small, the surface is made highly lipophilic, It is considered that the inking property is improved.

Since this specific copolymer exhibits excellent lipophilicity even if the amount of introduction of an aliphatic group having 7 or more carbon atoms having a bridge-like bond that contributes to lipophilicity is small, this specific copolymer has Can introduce sufficient acid groups to impart alkali solubility. The specific copolymer has excellent alkali solubility due to the monomer c that performs this function. Therefore, the specific copolymer unevenly distributed on the surface becomes soluble in alkali in the exposed area, so that the developability of the image recording layer is sufficient.
Therefore, when the above specific copolymer is used as an image recording layer of a lithographic printing plate precursor, it is possible to provide a lithographic printing plate precursor that is excellent in both ink depositing in the image area and developability in the non-image area. I believe.
Below, a specific copolymer is demonstrated.

(Specific copolymer)
The specific copolymer contains the monomer a represented by the above formula (2).

  Specific examples of the fluorine atom-containing substituent in Rf include the following fluoroalkyl (meth) acrylates.

CH ₂ = CRCO ₂ (CH ₂ ) _m C _n F _{2n + 1}
CH ₂ = CRCO ₂ (CH ₂ ) _m C _n F _2n H
However, m is 1 or 2, n is an integer of 4-12, R is a C1-C4 alkyl group.

Here, by using a fluoroalkyl group or a perfluoroalkyl group represented by Rf having 9 or more fluorine atoms, an image recording layer having a fluorine atom concentration distribution in the film thickness direction, specifically, An image recording layer having a concentration distribution in which the concentration of fluorine atoms near the surface of the image recording layer is high and the concentration of fluorine atoms decreases in the depth direction is formed.
Moreover, 9-30 are preferable and, as for the number of the fluorine atoms per unit in the monomer a, 13-25 are more preferable. When it is in the above range, the effect of orienting the specific copolymer on the surface is exhibited well, and the ink is excellent in the image area.
Moreover, 5-30 mmol / g is preferable and, as for content of the fluorine atom contained in a specific copolymer, 8-25 mmol / g is more preferable. If it is the said range, the oil repellency of a fluorine atom will become appropriate, and the ink deposit property to an image part will become favorable.

The specific copolymer contains the monomer b. Since the aliphatic group having a bridge-like bond contained in the monomer b is present in the vicinity of the surface of the image recording layer, high lipophilicity is imparted to the surface of the image area, and ink inking on the image area is improved. This aliphatic group is bulky compared to those having no bridge-like structure, and has a large number of carbon atoms in the structure, so that it has an affinity for a polymer having an acid group such as a coexisting alkali-soluble resin. It is considered that it can be imparted with excellent lipophilicity to the image-recording layer because it is low and does not embed in the acid group-containing polymer and becomes more easily surface-oriented.
The aliphatic group having 7 or more carbon atoms having a bridge-like bond in the specific copolymer is preferably 0.1 to 10 mmol / g, more preferably 0.2 to 8.0 mmol / g. 0.4 to 5 mmol / g is more preferable. If it is the said range, an image-recording layer will become a thing with high wall property and excellent alkali solubility.

  The monomer b is listed, for example, in Japanese Patent Application Laid-Open No. 2002-311577 filed earlier by the applicant of the present application. Hereinafter, specific examples (b-1) to (b-38) of the monomer b preferable for use in the specific copolymer are shown, but the monomer b is not limited thereto.

The specific copolymer contains the monomer c. The monomer c is not particularly limited as long as it is a compound having at least one polymerizable unsaturated group and acid group in the molecule. The monomer c is an alkali-soluble structural unit.
Among the acid groups, it is preferable to include, as a copolymerization component, monomers having acid groups listed in the following (1) to (6).

(1) Phenol group (-Ar-OH)
(2) Sulfonamide group (—SO ₂ NH—R)
(3) Substituted sulfonamide acid groups (hereinafter referred to as “active imide groups”. —SO ₂ NHCOR, —SONHSO ₂ R, —CONHSO ₂ R)
(4) Carboxylic acid group (—CO ₂ H)
(5) Sulfonic acid group (—SO ₃ H)
(6) Phosphate group (—OPO ₃ H ₂ )

Among the above (1) to (6), Ar is a divalent aryl linking group which may have a substituent, and R is a hydrogen atom or a hydrocarbon group which may have a substituent. .
Among the compounds having an acid group selected from the above (1) to (6), those having (1) a phenol group, (2) a sulfonamide group, and (4) a carboxylic acid group are preferable from the viewpoint of effects, (4) Those having a carboxylic acid group are more preferable from the viewpoint of ensuring sufficient inking properties and developability.

  Examples of the monomer (1) having a phenol group include monomers having a hydroxyaryl group in the side chain. Examples of the monomer having a hydroxyaryl group in the side chain include those containing at least one monomer represented by the following formula (a).

However, in formula (a), R ¹¹ represents a hydrogen atom or a methyl group. R ¹² represents a hydrogen atom, a halogen atom, a hydrocarbon group having 10 or less carbon atoms, an alkoxy group having 10 or less carbon atoms, or an aryloxy group having 10 or less carbon atoms. p represents an integer of 1 to 3.

  Examples of the monomer (2) having a sulfonamide group include a polymer having, as a main component, a minimum structural unit derived from a compound having a sulfonamide group. Examples of the compound as described above include compounds having at least one sulfonamide group in which at least one hydrogen atom is bonded to a nitrogen atom and one or more polymerizable unsaturated bond groups in the molecule. Among these, low molecular weight compounds having an acryloyl group, an allyl group, or a vinyloxy group, and a substituted or monosubstituted aminosulfonyl group or a substituted sulfonylimino group in the molecule are preferable. For example, they are represented by the following formulas (i) to (v). Compounds.

In formulas (i) to (v), x ¹ and x ² each independently represent —O— or —NR ⁷ . R ¹ and R ⁴ each independently represents a hydrogen atom or —CH ₃ . R ² , R ⁵ , R ⁹ , R ¹² and R ¹⁶ each independently represent a C 1-12 alkylene group, cycloalkylene group, arylene group or aralkylene group which may have a substituent. R ³ , R ⁷ and R ¹³ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group. R ⁶ and R ¹⁷ each independently represents a C 1-12 alkyl group, cycloalkyl group, aryl group or aralkyl group which may have a substituent. R ⁸ , R ¹⁰ and R ¹⁴ each independently represent a hydrogen atom or —CH ₃ . R ¹¹ and R ¹⁵ each independently represents a single bond or a C 1-12 alkylene group, cycloalkylene group, arylene group or aralkylene group which may have a substituent. Y ¹ and Y ² each independently represent a single bond or CO.

  Examples of the monomer (3) having an active imide group include a minimum structural unit derived from a compound having an active imide group. Examples of the structural unit as described above include a structural unit having at least one active imide group represented by the following structural formula and one or more polymerizable unsaturated groups.

  Examples of the monomer (4) having a carboxylic acid group include a minimum unit derived from a compound having at least one carboxylic acid group and at least one polymerizable unsaturated group in the molecule.

  Examples of the monomer (5) having a sulfonic acid group include a minimum unit derived from a compound having one or more sulfonic acid groups and polymerizable unsaturated groups in the molecule.

  Examples of the monomer (6) having a phosphate group include a minimum unit derived from a compound having at least one phosphate group and at least one polymerizable unsaturated group in the molecule.

The specific copolymer does not need to contain only one type of monomer having an acid group selected from the group consisting of the above (1) to (6), and two or more types of monomers having the same acid group are introduced. Two or more monomers having different acid groups may be introduced.
In addition, the amount of the acid group introduced into the specific copolymer is not particularly limited as long as the specific copolymer can be dissolved in an alkaline developer having a pH of 10 to 13.

  Particularly preferred as the monomer c is a monomer represented by the following formula (I).

In formula (I), R ¹ is a hydrogen atom or a methyl group, and is preferably a methyl group. The linking group represented by R ² in formula (I) is a linking group having 2 to 30 carbon atoms excluding the substituent, and specifically includes 2 such as alkylene, substituted alkylene, arylene, and substituted arylene. And a group having a structure in which a plurality of these groups are linked by an amide bond or an ester bond. For example, a preferred example of the linking group having a chain structure includes a structure in which alkylenes such as ethylene and propylene are linked through an ester bond.

The linking group represented by R ² is more preferably an (n + 1) -valent hydrocarbon group having an aliphatic cyclic structure having 3 to 30 carbon atoms. Specific examples include compounds having an aliphatic cyclic structure such as cyclopropane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, cyclohexyl, dicyclohexyl, norbornane. In addition, (n + 1) -valent hydrocarbons are similarly exemplified by removing (n + 1) hydrogen atoms on any carbon atom constituting a compound having an aliphatic chain structure having 5 to 20 atoms. Can do.

Any carbon atom of the compound constituting the aliphatic cyclic and chain structure may be substituted with a heteroatom selected from the group consisting of a nitrogen atom, an oxygen atom, or a sulfur atom. Two or more places may be substituted, and when two or more places are substituted, they may be substituted by different heteroatoms.
Examples of the substituent that can be introduced into the linking group represented by R ² include monovalent nonmetallic atomic groups other than hydrogen, such as halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups. And a group, an alkoxy group, an aryloxy group, a mercapto group, an aryl group, an alkenyl group, an alkynyl group, and the like.

When A in Formula (1) is NR ₃ —, R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R include an alkyl group, an aryl group, an alkenyl group, and an alkynyl group.
Specific examples of the alkyl group include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, isopropyl, isobutyl, sec-butyl, tert -C1-C1 such as butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclopentyl group, cyclohexyl group, 1-adamantyl group, 2-norbornyl group Examples include up to 10 linear, branched, or cyclic alkyl groups.

In formula (I), A is preferably an oxygen atom or —NH— because synthesis of the monomer represented by formula (I) is facilitated.
In the formula (I), n is an integer of 1 to 5, and 1 is preferable from the viewpoint of good inking properties. The acid group in the specific copolymer is preferably 0.2 to 10.0 mmol / g, more preferably 0.3 to 5.0 mmol / g per molecule of the specific copolymer. More preferably, it is 4 to 3.0 mmol / g.

In addition to monomer a, monomer b, and monomer c, other monomers may be used in combination with the specific copolymer to the extent that the effect of the present invention is not impaired, for the purpose of improving coatability. .
Here, examples of the monomer used in combination include known monomers such as acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylonitrile, maleic anhydride, maleic imide, and the like. The structural unit derived from is mentioned.

  Examples of the acrylic esters include methyl acrylate, ethyl acrylate, (n- or i-) propyl acrylate, (n-, i-, sec- or tert-) butyl acrylate, amyl acrylate, 2-ethylhexyl acrylate, Dodecyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 5-hydroxypentyl acrylate, cyclohexyl acrylate, allyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, glycidyl acrylate, benzyl acrylate, methoxybenzyl Acrylate, chlorobenzyl acrylate, 2- (p-hydroxyphenyl) ethyl acrylate Furfuryl acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, chlorophenyl acrylate, sulfamoylphenyl acrylate and the like.

  Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, (n- or i-) propyl methacrylate, (n-, i-, sec- or tert-) butyl methacrylate, amyl methacrylate, 2-ethylhexyl methacrylate, and dodecyl. Methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 5-hydroxypentyl methacrylate, cyclohexyl methacrylate, allyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate, methoxybenzyl methacrylate, chlorobenzyl Methacrylate, 2- (p-hydroxyphenyl) ethyl Methacrylate furfuryl methacrylate, tetrahydrofurfuryl methacrylate, phenyl methacrylate, chlorophenyl methacrylate, sulfamoylphenyl methacrylate and the like.

  Examples of the acrylamides include acrylamide, N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-butylacrylamide, N-benzylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, and N-tolylacrylamide. N- (p-hydroxyphenyl) acrylamide, N- (sulfamoylphenyl) acrylamide, N- (phenylsulfonyl) acrylamide, N- (tolylsulfonyl) acrylamide, N, N-dimethylacrylamide, N-methyl-N- Examples include phenylacrylamide, N-hydroxyethyl-N-methylacrylamide, and the like.

  Examples of the methacrylamides include methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-propylmethacrylamide, N-butylmethacrylamide, N-benzylmethacrylamide, N-hydroxyethylmethacrylamide, N -Phenylmethacrylamide, N-tolylmethacrylamide, N- (p-hydroxyphenyl) methacrylamide, N- (sulfamoylphenyl) methacrylamide, N- (phenylsulfonyl) methacrylamide, N- (tolylsulfonyl) methacrylamide N, N-dimethylmethacrylamide, N-methyl-N-phenylmethacrylamide, N-hydroxyethyl-N-methylmethacrylamide and the like.

  Examples of the vinyl esters include vinyl acetate, vinyl butyrate, vinyl benzoate, and the like.

  Examples of the styrenes include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, propyl styrene, cyclohexyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, methoxy styrene, and dimethoxy styrene. Chlorostyrene, dichlorostyrene, bromostyrene, iodostyrene, fluorostyrene, carboxystyrene and the like.

  Among the monomers used in combination as described above, it is preferable to use acrylic acid esters, methacrylic acid esters, vinyl esters, styrenes and acrylonitriles having 20 or less carbon atoms.

The average molecular weight of the specific copolymer is appropriately determined from the viewpoints of inking properties and developability. Usually, when the average molecular weight is high, the inking property is improved but the developing property tends to deteriorate. When the average molecular weight is low, the developing property is good but the inking property tends to be deteriorated.
The average molecular weight is preferably from 1,000 to 1,000,000, more preferably from 2,000 to 500,000, from the viewpoint of the balance between the effect of improving the coating properties and the inking property, the developability, the handling property, the solvent solubility, and the uniformity during coating. , 3000 to 300,000 are more preferable.
The specific copolymer may be linear, branched or have a block structure.

  When the specific copolymer described above is used in the image recording layer, the specific copolymer may be used alone, or other high functional groups having a fluorine-based substituent outside the scope of the present invention. One or more kinds of molecular compounds may be used in combination and used as a mixture. When used as a mixture, the content of the other polymer compound having a fluorine-based substituent is preferably 1 to 80% by mass, and 1 to 70% by mass with respect to the total weight of the specific copolymer. Is more preferable, and it is further more preferable that it is 1-60 mass%. As the other polymer compound having a fluorine-based substituent, a commercially available one can be used without limitation, and specifically, a fluorine-based surfactant widely used in the field is preferably used.

  The structures of other polymer compounds (P-1 to P-51) that can be used in combination with the specific copolymer are exemplified below together with their weight average molecular weights, but the other polymer compounds are limited to these. is not.

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.

(Other)
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 crosslinking 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.

<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.

<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.

<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.

(Overcoat layer)
In the untreated type lithographic printing plate precursor, a water-soluble overcoat layer can be provided on the image recording layer in order to prevent contamination of the surface of the heat-sensitive layer with a lipophilic substance. The water-soluble overcoat layer used in the present invention is preferably one that can be easily removed during printing, and contains a resin selected from water-soluble organic polymer compounds.
As the water-soluble organic polymer compound, a film formed by coating and drying has film-forming ability. Specifically, for example, polyvinyl acetate (however, a hydrolysis rate of 65% or more), polyacrylic Acid and its alkali metal salt or amine salt, polyacrylic acid copolymer and its alkali metal salt or amine salt, polymethacrylic acid and its alkali metal salt or amine salt, polymethacrylic acid copolymer and its alkali metal salt or amine Salt, polyacrylamide and copolymer thereof, polyhydroxyethyl acrylate, polyvinylpyrrolidone and copolymer thereof, polyvinyl methyl ether, polyvinyl methyl ether / maleic anhydride copolymer, poly-2-acrylamide-2-methyl-1- Propanesulfonic acid and its alkenyl Metal salt or amine salt, poly-2-acrylamido-2-methyl-1-propanesulfonic acid copolymer and alkali metal salt or amine salt thereof, gum arabic, fiber derivative (for example, carboxymethyl cellulose, carboxyethyl cellulose, Methyl cellulose, etc.) and modified products thereof, white dextrin, pullulan, enzymatically decomposed etherified dextrin and the like. In addition, two or more of these resins can be mixed and used depending on the purpose.

Moreover, you may add a water-soluble thing among the photothermal conversion agents mentioned above to an overcoat layer. Furthermore, for the purpose of ensuring the uniformity of coating, a nonionic surfactant such as polyoxyethylene nonylphenyl ether or polyoxyethylene dodecyl ether can be added to the overcoat layer in the case of aqueous solution coating. .
The dry coating amount of the overcoat layer is preferably 0.1 to 2.0 g / m ² . Within this range, the on-press developability is not impaired, and the surface of the heat-sensitive layer can be satisfactorily prevented from being contaminated with lipophilic substances such as fingerprints.

[Manufacture of lithographic printing plates]
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 helium-neon laser (He-Ne laser), argon laser, krypton laser, helium-cadmium laser, KrF excimer laser, semiconductor laser, YAG laser, and YAG-SHG laser.

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

When the image recording layer is an unprocessed type, the lithographic printing plate precursor according to the present invention is mounted on a printing machine without further processing after image exposure and is usually used with ink and / or fountain solution. You can print with the procedure. Further, as described in Japanese Patent No. 2938398, after being mounted on a printing machine cylinder, it is exposed with a laser mounted on the printing machine, and then ink and / or fountain solution is applied to perform on-machine development. It is also possible to do. In these cases, since the heat-sensitive layer is removed by ink and / or fountain solution on the printing press, there is no need for a separate development step, and there is no need to stop the printing press for printing after development. Printing can be continued as soon as development is completed.
Even in the case of having an untreated type heat-sensitive layer, it can be used for printing after developing with water or an appropriate aqueous solution as a developer.

  The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these.

1. Manufacture of an aluminum plate A molten metal is prepared using an aluminum alloy (aluminum 1 to 3) containing various metals in the ratio (mass%) shown in Table 1 below (the balance is made of Al and inevitable impurities), and the molten metal treatment is performed. After performing filtration, an ingot having a thickness of 500 mm and a width of 1200 mm was produced by a DC casting method. After the surface was shaved with a chamfering machine with an average thickness of 10 mm, the temperature was kept constant at 550 ° C. for about 5 hours, and when the temperature dropped to 400 ° C., rolling with a thickness of 2.7 mm using a hot rolling mill A board was used. Furthermore, after performing heat processing using a continuous annealing machine at 500 degreeC, it cold-rolled and finished to thickness 0.24mm and width 1030mm, and obtained the aluminum plates 1-3.

2. Production of lithographic printing plate support (Examples 1 to 12 and Comparative Example 1)
The aluminum plate obtained above was subjected to the following surface treatment to obtain each lithographic printing plate support shown in Table 2.

<Roughening treatment>
The roughening treatment was performed by continuously performing the following various treatments (a) to (k).
In addition, after each surface-roughening process, the water washing process was performed, and the liquid draining was performed with the nip roller after the water washing process. Moreover, when the process using the same kind of liquid was continuously performed, the water washing process was omitted between these processes.

(A) Mechanical roughening treatment Using an apparatus as shown in FIG. 1, the surface of the aluminum plate was sprayed using a slurry of slurry and water (specific gravity 1.12) as a polishing slurry. While being fed to the surface, a mechanical surface roughening treatment was performed using a rotating nylon brush.
In FIG. 1, 1 is an aluminum plate, 2 and 4 are roller brushes, 3 is a polishing slurry, and 5, 6, 7 and 8 are support rollers. As the abrasive, silica sand was used and classified so that the average particle diameter of the particles contained therein was 20 μm. The nylon brush used was a No. 3 brush with a material of 6 · 10 nylon and a hair length of 50 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller manages the load of the drive motor that rotates the brush against the load before pressing the brush roller against the aluminum plate, and the average surface roughness of the aluminum plate after roughening is 0.45 to 0.55 μm. It was pushed to become. The rotating direction of the brush was the same as the moving direction of the aluminum plate.

(B) Alkali etching treatment (first alkali etching treatment)
The aluminum plate was etched by spraying using an aqueous solution having a caustic soda concentration of 27 mass%, an aluminum ion concentration of 6.5 mass%, and 70 ° C. The surface of the aluminum plate to be subjected to electrochemical roughening treatment in a later step was dissolved by 7.0 g / m ² .

(C) Desmutting process (first desmutting process)
Next, a desmut treatment was performed in which the waste liquid of nitric acid used in the next electrochemical roughening treatment (first electrolytic roughening treatment) was sprayed at a liquid temperature of 35 ° C. for 2 seconds by spraying.

(D) Electrochemical roughening treatment (first electrolytic roughening treatment)
An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a nitric acid 10 g / L aqueous solution (containing 5 g / L of aluminum ions and copper as shown in Table 2), and a liquid temperature of 35 ° C.
The power source used was a power source that generates a trapezoidal alternating current. The time TP until the current value reached a peak from zero was 0.8 msec, and the duty (ta / T) was 0.5. The electrolytic cell used was the one shown in FIG.
The current density was 60 A / dm ² at the peak value of alternating current, and the ratio of the total amount of electricity during the anode reaction of the aluminum plate in the main electrolytic cell to the total amount of electricity during the cathode reaction was 0.95. Also. The amount of electricity applied to the aluminum plate was 110 C / dm ^{2 as} the total amount of electricity during the anode reaction.

(E) Alkali etching treatment (second alkali etching treatment)
The aluminum plate was etched by spraying using an aqueous solution having a caustic soda concentration of 27 mass%, an aluminum ion concentration of 6.5 mass%, and 45 ° C. The surface of the aluminum plate to be subjected to electrochemical roughening treatment in a later step was dissolved by 5.5 g / m ² .

(F) Desmutting process (second desmutting process)
Next, a desmut treatment was performed by spraying the waste liquid of hydrochloric acid used in the electrochemical roughening treatment (second electrolytic roughening treatment) in the next step at a liquid temperature of 30 ° C. for 2 seconds by spraying.

(G) Electrochemical roughening treatment (second electrolytic roughening treatment)
An electrochemical roughening treatment was continuously performed using an AC voltage of 50 Hz. The electrolytic solution at this time was a hydrochloric acid 10 g / L aqueous solution (containing 4.5 g / L of aluminum ions) at a temperature of 35 ° C.
The power source used was a power source that generates a trapezoidal alternating current. The time TP until the current value reached a peak from zero was 0.8 msec, and the duty (ta / T) was 0.5. The electrolytic cell used was the one shown in FIG.
The current density was 50 A / dm ² at the peak value of alternating current, and the ratio of the total amount of electricity during the anode reaction of the aluminum plate in the main electrolytic cell to the total amount of electricity during the cathode reaction was 0.95. Also. The amount of electricity applied to the aluminum plate was 63 C / dm ^{2 as} the total amount of electricity during the anode reaction.

(H) Alkali etching treatment (third alkali etching treatment)
The aluminum plate was etched by spraying using an aqueous solution having a caustic soda concentration of 27 mass%, an aluminum ion concentration of 6.5 mass%, and 45 ° C.

(I) Desmutting process (third desmutting process)
Next, a desmut treatment was performed by spraying the waste liquid (5 g / L of aluminum ions dissolved in a 170 g / L aqueous solution of sulfuric acid) generated in the next step by spraying at a liquid temperature of 35 ° C. for 4 seconds.

(J) Anodizing treatment Next, anodizing treatment was performed.
This anodizing treatment is performed by an anodizing apparatus having a structure shown in FIG. 5 (the lengths of the first and second electrolysis units are 6 m each, the lengths of the first and second feeding units are 3 m each, and the first and second feeding units). Anodization was carried out using the electrode lengths of 2.4 m each. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolysis units. All electrolytes had a sulfuric acid concentration of 170 g / L (containing 0.5 mass% of aluminum ions) and a temperature of 33 ° C. Then, water washing by spraying was performed.

In this anodizing device, currents from the power supplies 67a and 67b flow to the first power supply electrode 65a provided in the first power supply section 62a, flow to the aluminum plate 11 through the electrolytic solution, and in the first electrolysis section 63a. An oxide film is generated on the surface of the aluminum plate 11, passes through the electrolytic electrodes 66a and 66b provided in the first electrolysis unit 63a, and returns to the power sources 67a and 67b.
On the other hand, the current from the power supplies 67c and 67d flows to the second power supply electrode 65b provided in the second power supply part 62b, dissolves the electrolyte, flows to the aluminum plate, and the surface of the aluminum plate 11 by the second electrolysis part 63b. Then, the oxide film is generated, passes through the electrolytic electrodes 66c and 66d provided in the second electrolysis unit 63b, and returns to the power sources 67c and 67d. Note that both 64a and 64b are nip rollers.

The amount of electricity fed from the power sources 67a and 67b to the first feeding unit 62a is equal to the amount of electricity fed from the power sources 67c and 67d to the second feeding unit 62b, and the first electrolysis unit 63a and the second electrolysis unit The current density of 63b was 10 mA / dm ² in all cases. The amount of the oxide film generated in the first electrolysis unit 63a was 1.35 g / m ² . In the 2nd electric power feeding part 62b, it will feed through the oxide film surface produced | generated by the 1st electrolysis part 63a, and the final oxide film amount was 2.4 g / m < ² >.

(K) Hydrophilization treatment The aluminum plate was immersed in a 1.0% by mass aqueous solution of sodium silicate (liquid temperature 50 ° C., pH 11.5) for 8 seconds. The amount of Si on the surface of the aluminum plate measured with a fluorescent X-ray analyzer was 3.5 mg / m ² . Then, after performing the water washing process by the spray using well water, it was made to dry.

3. Observation of the surface of the support for a lithographic printing plate The surface shape of the support for a lithographic printing plate obtained in Examples 1 to 12 and Comparative Example 1 is a scanning electric microscope (JSM-5500, manufactured by JEOL Ltd. The same shall apply hereinafter. ) Was used to evaluate the uniformity of pits formed on the surface. As a result, the uniformity of the unevenness on the surface of Comparative Example 1 was evaluated as △, and the level equivalent to this was evaluated as △, and the better than this was evaluated as ○. The results are shown in Table 2.
Moreover, when the surface shape of the lithographic printing plate support obtained in Examples 1 to 12 was observed with a scanning electron microscope at a magnification of 50000 times, the surface of these lithographic printing plate supports had a diameter on the surface. Fine unevenness of 0.1 to 0.3 μm was generated uniformly and densely. Further, when observed with a scanning electron microscope at a magnification of 2000 times, a concave portion having an average opening diameter of 1 to 3 μm was formed on the surface of these lithographic printing plate supports. Fine irregularities having a diameter of 0.1 to 0.3 μm were generated by being superimposed on the irregularities having a diameter of 1 to 3 μm. Moreover, the unevenness | corrugation of 1-3 micrometers in diameter was produced | generated uniformly. On the other hand, when the surface shape of the lithographic printing plate support obtained in Comparative Example 1 was observed in the same manner, irregularities were generated on the surface, but these irregularities were compared to the case of the example. The depth was shallow and the diameter was as small as 0.5 to 1.0 μm.

4). Preparation of lithographic printing plate precursor A lithographic printing plate precursor was obtained by providing each lithographic printing plate support obtained above with a thermal positive type image recording layer as follows. Before providing the image recording layer, an undercoat layer was provided as described later.
On the lithographic printing plate support, an undercoat solution having the following composition was applied and dried at 80 ° C. for 15 seconds to form a coating film of an undercoat layer. The coating amount of the coating film after drying was 15 mg / m ² .

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

Next, a wire bar is used on a lithographic printing plate support provided with an undercoat layer so that the coating amount after drying the coating liquid A1 for the image recording layer described below (heat-sensitive layer coating amount) is 0.85 g / m ^2. And then dried at 140 ° C. for 50 seconds.
Thereafter, the following image recording layer coating solution B1 was applied using a wire bar so that the coating amount after drying (the coating amount of the heat-sensitive layer) was 1.1 g / m ² , dried at 140 ° C. for 60 seconds, and the multilayer type A thermal positive type image recording layer was formed to obtain a lithographic printing plate precursor.

<Coating liquid A1 for image recording layer>
N- (4-aminosulfonylphenyl) methacrylamide / acrylonitrile / methyl methacrylate copolymer (molar ratio 36/34/30, weight average molecular weight 50,000, acid value 2.65) 1.920 g
-M, p-cresol novolak (m-cresol novolak / p-cresol novolak = 6/4, weight average molecular weight 4000) 0.213 g
-Cyanine dye A represented by the following formula 0.032 g
・ 0.008 g of p-toluenesulfonic acid
・ Tetrahydrophthalic anhydride 0.190g
・ Bis-p-hydroxyphenylsulfone 0.126 g
・ 2-methoxy-4- (N-phenylamino) benzenediazonium ・ hexafluorophosphate 0.032 g
・ Victoria Pure Blue (Dye with BO anion as 1-naphthalenesulfonic acid anion) 0.078g
・ Fluorine-based surfactant (Megafac F-780, manufactured by Dainippon Ink & Chemicals, Inc.) 0.020 g
・ Γ-Butyllactone 13.18g
・ Methyl ethyl ketone 25.41g
・ 1-methoxy-2-propanol 12.97g

<Image Recording Layer Coating Liquid B1>
-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 A represented by the above formula
-Structural polymer B / methyl ethyl ketone 30% solution represented by the following formula (Structural polymer B / methyl ethyl ketone 30% solution) 0.140 g
-Quaternary ammonium salt C shown by the following formula 0.004 g
・ Sulfonium salt D represented by the following formula: 0.065 g
-Fluorosurfactant (Megafac F-780, manufactured by Dainippon Ink & Chemicals, Inc.) 0.004g
・ Fluorosurfactant (Megafac F-782, manufactured by Dainippon Ink & Chemicals, Inc.) 0.020 g
・ Methyl ethyl ketone 10.39g
・ 1-methoxy-2-propanol 20.98g

5. Evaluation of planographic printing plate precursor The printing durability and stain resistance of the planographic printing plate were evaluated by the following methods.
(1) Printing durability The obtained lithographic printing plate precursor was imaged using a TrendSetter manufactured by Creo at a drum rotation speed of 150 rpm and a beam intensity of 10 W.
Thereafter, using a PS processor 940H manufactured by Fuji Photo Film Co., Ltd. charged with an 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: More than 30,000 sheets A-B: More than 20,000 sheets and less than 30,000 sheets

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

  As is clear from Table 2, the lithographic printing plate precursor using the lithographic printing plate support prepared in Examples 1 to 12 was compared with Comparative Example 1 in which copper was not added in the first electrolytic surface roughening treatment. In comparison, it was found that the uniformity of the pits became equal or better, and the printing durability and stain resistance and the balance between them were excellent.

It is a side view which shows the concept of the process of the mechanical roughening process in the manufacturing method of the support body for lithographic printing plates of this invention. It is a graph which shows an example of the alternating waveform current waveform figure used for the electrochemical roughening process in the manufacturing method of the support body for lithographic printing plates of this invention. It is a side view which shows an example of the radial type cell in the electrochemical roughening process using 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 anodizing apparatus of the two-step electric power feeding method used for the anodizing process in the manufacturing method of the support body for lithographic printing plates of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aluminum plate 2, 4 Roller-like brush 3 Polishing slurry liquid 5, 6, 7, 8 Support roller 11 Aluminum plate 12 Radial drum roller 13a, 13b Main electrode 14 Electrolytic process liquid 15 Electrolyte supply port 16 Slit 17 Electrolyte path 18 Auxiliary anodes 19a, 19b Thyristors 20 AC power supply 40 Main electrolytic cell 50 Auxiliary anode cell 62a First power supply unit 62b Second power supply unit 63a First electrolysis unit 63b Second electrolysis unit 64a, 64b Nip roller 65a First power supply electrode 65b Second power supply Electrodes 66a, 66b, 66c, 66d Electrolytic electrodes 67a, 67b, 67c, 67d Power supply 410 Anodizing device 412 Power supply tank 414 Electrolytic treatment tank 416 Aluminum plate 418, 426 Electrolytic solution 420 Power supply electrode 422, 428 Roller 424 Nip roller 430 Electrolytic electrode 32 tank wall 434 DC power supply

Claims (4)

A method for producing a lithographic printing plate support, wherein an aluminum plate is subjected to an electrochemical surface roughening treatment in an acidic aqueous solution to obtain a lithographic printing plate support,
The manufacturing method of the support body for lithographic printing plates in which the said acidic aqueous solution contains 0.1-3.0 mass% Cu.   The manufacturing method of the support body for lithographic printing plates of Claim 1 whose Cu content of the said aluminum plate is 0.010 mass% or less.   The method for producing a lithographic printing plate support according to claim 1 or 2, wherein the electrochemical roughening treatment is an electrochemical roughening treatment using an alternating current in an aqueous solution containing nitric acid. . At least on the aluminum plate
Etching treatment in alkaline solution,
Electrochemical roughening treatment using alternating current in an aqueous solution containing nitric acid,
Etching treatment in an alkaline aqueous solution; and
Electrochemical roughening treatment using alternating current in aqueous solution containing hydrochloric acid,
Is a method for producing a lithographic printing plate support, wherein a lithographic printing plate support is obtained in this order,
A method for producing a lithographic printing plate support, wherein the aqueous solution containing nitric acid and / or the aqueous solution containing hydrochloric acid contains 0.1 to 3.0% by mass of Cu.

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