JP5498403B2 - Lithographic printing plate support, method for producing lithographic printing plate support, and lithographic printing plate precursor - Google Patents

Description

  The present invention relates to a lithographic printing plate support, a method for producing a lithographic printing plate support, and a lithographic printing plate precursor.

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

  An aluminum support for a lithographic printing plate used for a lithographic printing plate (hereinafter simply referred to as a “support for a lithographic printing plate”) is used so that its surface bears a non-image portion, and therefore has hydrophilicity and water retention. Are required to have various performances which are contradictory to each other, for example, excellent adhesion, and excellent adhesion to an image recording layer provided thereon. If the hydrophilicity of the support is too low, ink will adhere to the non-image area during printing, and the blanket cylinder will be soiled, and so-called background soiling will occur. On the other hand, if the water holding capacity of the support is too low, the shadow portion is clogged unless dampening water is increased during printing. Therefore, the so-called water width is narrowed.

  Various studies have been made to obtain a lithographic printing plate support having good performance. For example, in Patent Document 1, after the surface of the roughened aluminum plate is anodized as the first stage, the pore diameter is smaller than the micropores of the first stage anodized film as the second stage. A method for producing a lithographic printing plate support by anodizing again is disclosed. The lithographic printing plate obtained by using the lithographic printing plate support is described to improve the adhesion with the photosensitive layer without deteriorating the ink removal, and the excellent printing durability with no highlights flying. Yes.

  On the other hand, when printing, printing may be temporarily stopped. In this case, the lithographic printing plate is left in a state where it is attached to the plate cylinder, and the non-image area becomes dirty due to the influence of contamination in the atmosphere. For this reason, when printing is paused and resumed, it becomes necessary to print several sheets until normal printing is performed, and there is a disadvantage that printing paper is wasted. This inconvenience has been found to be particularly noticeable in lithographic printing plates that have been electrochemically roughened in an acidic solution containing hydrochloric acid. In the following description, the number of damaged sheets generated when printing is paused and resumed is also referred to as neglectability, and the fact that the number of damaged sheets is small is referred to as good neglectability.

  In addition, many studies have been conducted on computer-to-plate (CTP) systems that have made remarkable progress in recent years. In particular, there is a need for a lithographic printing plate precursor that can be mounted on a printing machine as it is and printed without being subjected to development processing after exposure, in order to further streamline the process and solve the waste liquid treatment problem.

  One method of eliminating the processing step is to mount the exposed lithographic printing plate precursor on the plate cylinder of the printing press, and supply dampening water and ink while rotating the plate cylinder to remove the lithographic printing plate precursor. There is a method called on-machine development that removes the image area. That is, the lithographic printing plate precursor is exposed to light and mounted on a printing machine as it is, and development processing is completed in a normal printing process. A lithographic printing plate precursor suitable for on-press development has an image recording layer that is soluble in fountain solution or an ink solvent, and is bright when developed on a press in a bright room. It is required to have room handling properties. In the following, the number of print sheets required until the on-press development on the printing machine in the unexposed area is completed and the ink is not transferred to the non-image area is referred to as on-machine developability. It is said that the on-press developability is good when the number of sheets is small.

JP 11-291657 A

  The present inventors have examined various performances of a lithographic printing plate and a lithographic printing original plate obtained using the lithographic printing plate support specifically described in Patent Document 1, and found that It has been found that printing durability, or on-press developability and printing durability are in a trade-off relationship, and the two cannot be compatible and are not always satisfactory in practice. Furthermore, it has been found that the scratch resistance of the lithographic printing plate support needs to be improved.

  Therefore, in view of the above circumstances, the present invention can provide a lithographic printing plate precursor exhibiting excellent neglectability and printing durability when used as a lithographic printing plate, and exhibiting excellent on-press developability. An object is to provide a lithographic printing plate support excellent in scratch resistance, a method for producing a lithographic printing plate support, and a lithographic printing plate precursor.

As a result of intensive studies to achieve the above object, the present inventors have found that the above problems can be solved by controlling the shape of the micropores in the anodized film.
That is, the present invention provides the following (1) to (11).

(1) A lithographic printing plate support comprising an aluminum plate and an aluminum anodized film thereon, and having micropores extending in the depth direction from the surface opposite to the aluminum plate in the anodized film Because
The micropore communicates with a large-diameter hole extending from the surface of the anodized film to a position having a depth of 5 to 60 nm (depth A) and a bottom of the large-diameter hole, and having a depth of 900 to 2000 nm from the communication position. It consists of a small diameter hole that extends to the position,
The average diameter of the large-diameter hole portion on the surface of the anodized film is more than 60 nm and not more than 100 nm, and the average diameter and the depth A satisfy the relationship of (depth A / average diameter) = 0.05 to 0.95,
A support for a lithographic printing plate, wherein the average diameter of the small-diameter hole at the communicating position is greater than 0 and less than 15 nm.

(2) The lithographic printing plate support according to (1), wherein an average diameter of the large-diameter hole is more than 60 nm and not more than 85 nm.
(3) The lithographic printing plate support according to (1) or (2), wherein the depth A is 7 to 50 nm.
(4) The lithographic printing plate support according to any one of (1) to (3), wherein the value of (depth A / average diameter) is 0.1 or more and less than 0.8.

(5) a first anodizing treatment step for anodizing the aluminum plate;
A pore-wide treatment step in which the aluminum plate having the anodized film obtained in the first anodizing treatment step is brought into contact with an aqueous acid solution or an aqueous alkaline solution to increase the diameter of the micropores in the anodized film;
A lithographic printing plate support according to any one of (1) to (4), comprising a second anodizing treatment step of anodizing the aluminum plate obtained in the pore-wide treatment step A method for producing a support.
(6) Ratio (film) of the thickness of the anodized film (film thickness 1) obtained in the first anodizing process and the thickness of the anodized film (film thickness 2) obtained in the second anodizing process The method for producing a lithographic printing plate support according to (5), wherein the thickness 1 / thickness 2) is 0.002 to 0.15.

(7) The method for producing a lithographic printing plate support according to (5) or (6), wherein the thickness of the anodized film obtained in the first anodizing treatment step is 15 to 80 nm.
(8) The method for producing a lithographic printing plate support according to any one of (5) to (7), wherein the thickness of the anodized film obtained in the second anodizing treatment step is 900 to 2000 nm.
(9) The method for producing a lithographic printing plate support according to any one of (5) to (8), wherein the first anodizing treatment step is performed in an electrolytic solution containing phosphoric acid.

(10) A lithographic printing plate precursor comprising an image recording layer on the lithographic printing plate support according to any one of (1) to (4).
(11) The lithographic printing plate precursor as described in (10), wherein the image recording layer is an image recording layer on which an image is formed by exposure and the non-exposed portion can be removed by printing ink and / or fountain solution.

According to the present invention, a lithographic printing plate support excellent in scratch resistance, a method for producing the same, and a lithographic printing plate precursor using the same can be obtained. Can be provided.
Further, in the on-press development type lithographic printing plate, it is possible to improve the printing durability particularly while maintaining the on-press developability.

It is a typical sectional view of one embodiment of a lithographic printing plate support of the present invention. It is typical sectional drawing of the board | substrate and anodized film which show the manufacturing method of the support body for lithographic printing plates of this invention in order of a process. It is typical sectional drawing of the board | substrate and anodized film which show the suitable embodiment of the manufacturing method of the support body for lithographic printing plates of this invention in order of a process. 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 a side view which shows the concept of the process of the brush graining used for the mechanical roughening process in preparation 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 preparation of the support body for lithographic printing plates of this invention.

The lithographic printing plate support of the present invention and the production method thereof will be described below.
The lithographic printing plate support of the present invention comprises an aluminum plate and an anodized film formed thereon, and the micropores in the anodized film have large diameter holes with a large average diameter and a small average diameter. The small-diameter hole portion is configured to be connected along the depth direction (the thickness direction of the film). In particular, in the present invention, by controlling the average diameter and depth of the large-diameter hole portion having a large average diameter in the micropore, the neglectability and printing durability, which have been in a trade-off relationship, or the machine The relationship between upper developability and printing durability can be achieved at a higher level.
In addition, by using a liquid containing phosphoric acid or oxalic acid as an electrolytic solution in the first anodizing process described later, it is possible to improve the micropore occupancy ratio on the surface represented by the following general formula. Thus, a lithographic printing plate having better printing durability can be obtained.
Micropore occupation ratio = micropore density × (average diameter of large-diameter hole / 2) ² × π

FIG. 1 is a schematic cross-sectional view of an embodiment of the lithographic printing plate support of the present invention.
The planographic printing plate support 10 shown in FIG. 1 has a laminated structure in which an aluminum plate 12 and an aluminum anodic oxide film 14 are laminated in this order. The anodized film 14 has micropores 16 extending from the surface thereof toward the aluminum plate 12, and the micropores 16 are composed of a large diameter hole portion 18 and a small diameter hole portion 20.
First, the aluminum plate 12 and the anodized film 14 will be described in detail.

<Aluminum plate>
The aluminum plate 12 (aluminum support) used in the present invention is a metal whose main component is aluminum that is dimensionally stable, and is made of aluminum or an aluminum alloy. In addition to a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, or a plastic film or paper laminated or vapor-deposited with aluminum (alloy) is selected. Furthermore, a composite sheet in which an aluminum sheet is bonded to a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327 may be used.

  In the following description, the above-described plate made of aluminum or aluminum alloy is collectively referred to as an aluminum plate 12. Examples of the foreign element contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of the foreign element in the alloy is 10% by mass or less. In the present invention, a pure aluminum plate is suitable. However, since pure aluminum is difficult to manufacture in terms of smelting technology, it may contain a slightly different element. Thus, the composition of the aluminum plate 12 applied to the present invention is not specified, and conventionally known and used materials such as JIS A 1050, JIS A 1100, JIS A 3103, JIS A 3005, etc. Can be used as appropriate.

  Further, the aluminum plate 12 used in the present invention is usually processed while continuously running in a web shape, the width is about 400 mm to 2000 mm, and the thickness is about 0.1 mm to 0.6 mm. The thickness can be changed as appropriate according to the size of the printing press, the size of the printing plate, and the desire of the user.

  The aluminum plate is appropriately subjected to substrate surface treatment described later.

<Anodized film>
The anodized film 14 refers to an anodized aluminum film that is generally formed on the surface of the aluminum plate 12 by an anodizing treatment and has ultrafine micropores 16 that are perpendicular to the film surface and are uniformly distributed. . The micropores 16 extend along the thickness direction (aluminum plate 12 side) from the surface of the anodized film opposite to the aluminum plate 12.

The micropores 16 in the anodic oxide film 14 include a large-diameter hole 18 extending from the surface of the anodic oxide film to a depth of 5 to 60 nm (depth A: see FIG. 1), and a bottom of the large-diameter hole 18. The small-diameter hole 20 extends from the communication position to a position having a depth of 900 to 2000 nm.
Below, the large diameter hole part 18 and the small diameter hole part 20 are explained in full detail.

(Large hole)
The average diameter (average opening diameter) of the large-diameter hole 18 on the surface of the anodic oxide film is more than 60 nm and 100 nm or less. The average diameter is preferably more than 60 nm and not more than 85 nm in that the lithographic printing plate obtained using the lithographic printing plate support is more excellent in printing durability. Within this range, excellent printing durability and neglectability of the lithographic printing plate obtained using the lithographic printing plate support, and excellent on-board of the lithographic printing plate precursor obtained using the support. Developability is achieved. If the average diameter exceeds 100 nm, an increase in surface area cannot be expected, and an improvement in printing durability cannot be expected.
The average diameter of the large-diameter hole portion 18 is in the range of 400 × 600 nm ² in the four images obtained by observing the surface of the anodic oxide film 14 with N = 4 FE-SEM at a magnification of 150,000 times. It is the value obtained by measuring the diameter of the micropore (large-diameter hole) and averaging it.
In addition, when the shape of the opening part of the large diameter hole part 18 is not circular shape, a circle equivalent diameter is used. The “equivalent circle diameter” is a diameter of the circle when the shape of the opening is assumed to be a circle having the same projected area as the projected area of the opening.

The bottom of the large-diameter hole 18 is located at a depth of 5 to 60 nm (hereinafter also referred to as depth A) from the anodized film surface. That is, the large-diameter hole 18 is a hole extending from 5 to 60 nm in the depth direction (thickness direction) from the anodized film surface. The depth is 7 to 50 nm in that the lithographic printing plate obtained by using the lithographic printing plate support has better printing durability, neglectability, and on-press developability of the lithographic printing plate precursor. preferable.
When the depth is less than 5 nm, a sufficient anchor effect cannot be obtained and the printing durability of the lithographic printing plate is poor. When the depth exceeds 60 nm, the neglectability of the lithographic printing plate and the on-press developability of the lithographic printing plate precursor are inferior.
In addition, the said depth is the value which took the photograph (150,000 times) of the cross section of the anodic oxide film 14, measured the depth of the 25 or more large diameter hole part, and averaged it.

The relationship (depth A / average diameter) between the average diameter of the large-diameter hole portion 18 and the depth A where the bottom portion is located satisfies the relationship of 0.05 to 0.95. If it is this range, a desired effect will be acquired. In the point that the printing durability of the lithographic printing plate obtained by using the lithographic printing plate support, the neglectability, and the on-press developability of the lithographic printing plate precursor obtained by using the support are ( The depth (A / average diameter) is preferably 0.1 or more and less than 0.8.
When (depth A / average diameter) is less than 0.05, the printing durability of the planographic printing plate is poor. When (depth A / average diameter) exceeds 0.95, the neglectability of the lithographic printing plate and the on-press developability of the lithographic printing plate precursor are inferior.

The shape of the large-diameter hole 18 is not particularly limited, and includes a substantially hemispherical shape, a substantially straight tubular shape (substantially cylindrical shape), a conical shape whose diameter decreases in the depth direction, and the like, and preferably has a substantially hemispherical shape. . The shape of the bottom of the large-diameter hole 18 is not particularly limited, and may be a curved surface (convex shape) or a flat shape.
The inner diameter of the large-diameter hole 18 is not particularly limited, but is usually the same size as the diameter of the opening or smaller than the diameter of the opening. In addition, the internal diameter of the large diameter hole 18 may have a difference of about 1 to 30 nm from the diameter of the opening.

(Small hole)
As shown in FIG. 1, the small-diameter hole 20 is a hole that communicates with the bottom of the large-diameter hole 18 and extends further in the depth direction than the communication position. One small-diameter hole 20 usually communicates with one large-diameter hole 18, but two or more small-diameter holes 20 may communicate with the bottom of one large-diameter hole 18.
The average diameter at the communication position of the small-diameter hole 20 is greater than 0 and less than 15 nm. The average diameter is preferably 10 nm or less, more preferably 5 to 10 nm in terms of neglectability and on-press developability.
When the average diameter is 15 nm or more, the neglectability of the lithographic printing plate using the lithographic printing plate support of the present invention and the on-press developability of the lithographic printing plate precursor are poor.
The average diameter of the small-diameter hole 20 is such that the surface of the anodic oxide film 14 is observed with N = 4 FE-SEMs with a magnification of 150,000 times, and the obtained four images have a microscopic range of 400 × 600 nm ^2. It is the value obtained by measuring the diameter of the pore (small-diameter hole) and averaging it.
In addition, when the shape of the opening part of the small diameter hole part 20 is not circular shape, a circle equivalent diameter is used. The “equivalent circle diameter” is a diameter of the circle when the shape of the opening is assumed to be a circle having the same projected area as the projected area of the opening.

The bottom of the small-diameter hole 20 is located at a place extending 900 to 2000 nm in the depth direction from the communication position with the large-diameter hole 18 (corresponding to the depth A described above). In other words, the small-diameter hole 20 is a hole extending further in the depth direction (thickness direction) from the communication position with the large-diameter hole 18, and the length of the small-diameter hole 20 is 900 to 2000 nm. From the viewpoint of scratch resistance as a support for a lithographic printing plate, the bottom is preferably located at a location extending 900 to 1500 nm from the communicating position.
When the depth is less than 900 nm, the scratch resistance of the lithographic printing plate support is poor. When the depth exceeds 2000 nm, the treatment time is prolonged, and the productivity and economy are inferior.
In addition, the said depth is the value which took the photograph (150,000 times) of the cross section of the anodic oxide film 14, measured the depth of 25 or more small diameter holes, and averaged it.

The ratio of the average diameter at the communication position of the small-diameter hole 20 and the average diameter of the large-diameter hole 18 on the surface of the anodized film (large-diameter hole diameter / small-diameter hole diameter) is preferably more than 5.0. , More than 6.0, more preferably 7.5 to 12.5. Within the above range, the resulting lithographic printing plate has better printing durability, neglectability, and on-press developability of the lithographic printing plate precursor.
When the ratio of the average diameter is 5.0 or less, it may be difficult to achieve both printing durability and left-to-stain property / on-press development property.

The shape of the small-diameter hole 20 is not particularly limited, and includes a substantially straight tube (substantially cylindrical shape), a conical shape whose diameter decreases in the depth direction, and the like, preferably a substantially straight tube. Moreover, the shape of the bottom part of the small diameter hole part 20 is not specifically limited, A curved surface shape (convex shape) may be sufficient, and planar shape may be sufficient.
The inner diameter of the small-diameter hole 20 is not particularly limited, but is usually the same size as the diameter at the communication position or smaller than the diameter. Note that the inner diameter of the small-diameter hole 20 may have a difference of about 10 to 90 nm from the diameter of the opening.

The density of the micropores 16 in the anodic oxide film 14 is not particularly limited, but it is 50 to 4000 in that the obtained lithographic printing plate has better printing durability, neglectability and on-press developability of the lithographic printing plate precursor. it is preferably pieces / [mu] m ^2, and more preferably 100 to 3000 cells / [mu] m ^2.

The coating amount of the anodized film 14 is not particularly limited, but is preferably 2.3 to 5.5 g / m ² , preferably 2.3 to 4.0 g / m ^{2 in} that the obtained lithographic printing plate is more excellent in scratch resistance. Is more preferable.

The occupation ratio of the micropores 16 represented by the following formula is not particularly limited, but it is 2 in that the printing durability and neglectability of the obtained lithographic printing plate and the on-press developability of the lithographic printing plate precursor are more excellent. 0.0 or more is preferable, and 2.5 or more and 3.5 or less are more preferable.
Micropore occupation ratio = micropore density × (average diameter of large-diameter hole / 2) ² × π
Furthermore, the volume ratio of the micropores 16 represented by the following formula is a parameter relating to the volume of the large-diameter hole, and the printing durability and neglectability of the resulting lithographic printing plate and the on-board size of the lithographic printing plate precursor In terms of more excellent developability, 50 or more and 150 or less are preferable, and 55 or more and 140 or less are more preferable.
Pore volume ratio = micropore occupation ratio x depth of large-diameter hole

  In addition, an image recording layer described later can be provided on the surface of the above-described lithographic printing plate support so that it can be used as a lithographic printing original plate.

<Method for producing support for lithographic printing plate>
The method for producing a lithographic printing plate support of the present invention will be described below.
Although the manufacturing method of the support for lithographic printing plates of this invention is not specifically limited, The manufacturing method which implements the following processes in order is preferable.
(Roughening treatment step) A step of roughening the aluminum plate (first anodizing step) A step of anodizing the roughened aluminum plate (pore wide treatment step) In the first anodizing step The obtained aluminum plate having an anodized film was brought into contact with an aqueous acid solution or an aqueous alkali solution to increase the diameter of the micropores in the anodized film (second anodizing process step). Step of Anodizing Aluminum Plate (Hydrophilic Treatment Step) Step of Applying Hydrophilization Treatment to Aluminum Plate Obtained in Second Anodizing Treatment Step Each of the above steps will be described in detail below. Note that the roughening treatment step and the hydrophilization treatment step may be omitted if not necessary for the effect of the invention. 2 and 3 are schematic cross-sectional views of the substrate and the anodic oxide film showing the order from the first anodizing treatment step to the second anodizing treatment step.

<Roughening treatment process>
The roughening treatment step is a step of subjecting the surface of the aluminum plate to a roughening treatment including an electrochemical roughening treatment. This step is preferably performed before the first anodizing step described later, but may not be performed as long as the surface of the aluminum plate already has a preferable surface shape.

The surface roughening treatment may be performed only by electrochemical surface roughening treatment, but may be performed by combining electrochemical surface roughening treatment with mechanical surface roughening treatment and / or chemical surface roughening treatment. Also good.
When the mechanical surface roughening treatment and the electrochemical surface roughening treatment are combined, it is preferable to perform the electrochemical surface roughening treatment after the mechanical surface roughening treatment.

  In the present invention, the electrochemical surface roughening treatment is preferably performed in an aqueous solution of nitric acid or hydrochloric acid.

The mechanical surface roughening treatment is generally performed for the purpose of setting the surface of the aluminum plate to a surface roughness _Ra : 0.35 to 1.0 μm.
In the present invention, the conditions for the mechanical surface roughening treatment are not particularly limited, but for example, it can be applied according to the method described in Japanese Patent Publication No. 50-40047. The mechanical surface roughening treatment can be performed by brush grain processing using a pumiston suspension or can be performed by a transfer method.
Further, the chemical surface roughening treatment is not particularly limited, and can be performed according to a known method.

After the mechanical surface roughening treatment, the following chemical etching treatment is preferably performed.
The chemical etching process performed after the mechanical roughening process smoothes the uneven edges of the surface of the aluminum plate, prevents ink from being caught during printing, and improves the stain resistance of the lithographic printing plate At the same time, it is performed to remove unnecessary materials such as abrasive particles remaining on the surface.
As the chemical etching treatment, acid etching or alkali etching is known, but as a method that is particularly excellent in terms of etching efficiency, chemical etching treatment using an alkaline solution (hereinafter also referred to as “alkali etching treatment”). ).

The alkaline agent used in the alkaline solution is not particularly limited, and preferred examples include caustic soda, caustic potash, sodium metasilicate, sodium carbonate, sodium aluminate, and sodium gluconate.
Each alkaline agent may contain aluminum ions. The concentration of the alkaline solution is preferably 0.01% by mass or more, more preferably 3% by mass or more, more preferably 30% by mass or less, and more preferably 25% by mass or less. preferable.
Furthermore, the temperature of the alkaline solution is preferably room temperature or higher, more preferably 30 ° C. or higher, preferably 80 ° C. or lower, and more preferably 75 ° C. or lower.

The etching amount is preferably 0.1 g / m ² or more, more preferably 1 g / m ² or more, more preferably 20 g / m ² or less, and 10 g / m ² or less. Is more preferable.
The treatment time is preferably 2 seconds to 5 minutes corresponding to the etching amount, and more preferably 2 to 10 seconds from the viewpoint of improving productivity.

In the present invention, when an alkali etching treatment is performed after the mechanical surface roughening treatment, a chemical etching treatment (hereinafter referred to as “desmut treatment”) is performed using a low-temperature acidic solution in order to remove products generated by the alkali etching treatment. It is also preferable to apply.
Although the acid used for an acidic solution is not specifically limited, For example, a sulfuric acid, nitric acid, and hydrochloric acid are mentioned. The concentration of the acidic solution is preferably 1 to 50% by mass. Moreover, it is preferable that the temperature of an acidic solution is 20-80 degreeC. When the concentration and temperature of the acidic solution are within this range, the spot-like stain resistance of the lithographic printing plate using the lithographic printing plate support of the present invention is further improved.

  In the present invention, the roughening process is a process of applying an electrochemical roughening process after performing a mechanical roughening process and a chemical etching process as desired. Even when the electrochemical surface roughening treatment is performed without performing the chemical surface roughening treatment, the chemical etching treatment can be performed using an alkaline aqueous solution such as caustic soda before the electrochemical surface roughening treatment. Thereby, impurities existing in the vicinity of the surface of the aluminum plate can be removed.

The electrochemical roughening treatment is suitable for making a lithographic printing plate having excellent printability because it is easy to impart fine irregularities (pits) to the surface of the aluminum plate.
The electrochemical surface roughening treatment is performed using direct current or alternating current in an aqueous solution mainly composed of nitric acid or hydrochloric acid.

  Moreover, it is preferable to perform the following chemical etching process after an electrochemical roughening process. Smut and intermetallic compounds exist on the surface of the aluminum plate after the electrochemical roughening treatment. In the chemical etching process performed after the electrochemical surface roughening process, it is preferable to first perform a chemical etching process (alkali etching process) using an alkaline solution in order to efficiently remove smut. Regarding various conditions of the chemical etching treatment using an alkaline solution, the treatment temperature is preferably 20 to 80 ° C., and the treatment time is preferably 1 to 60 seconds. Moreover, it is preferable to contain aluminum ion in an alkaline solution.

Furthermore, after the electrochemical surface roughening treatment, a chemical etching treatment using an alkaline solution is performed, and then a chemical etching treatment (desmut treatment) is performed using a low-temperature acidic solution in order to remove the resulting products. Is preferred.
Even when the alkali etching treatment is not performed after the electrochemical surface roughening treatment, it is preferable to perform a desmut treatment in order to efficiently remove the smut.

  In the present invention, any of the above-described chemical etching treatments can be performed by a dipping method, a shower method, a coating method, or the like, and is not particularly limited.

<First anodizing process>
In the first anodizing treatment step, the aluminum plate having the micropores extending in the depth direction (thickness direction) is formed on the surface of the aluminum plate by anodizing the aluminum plate subjected to the roughening treatment. This is a step of forming a film. By the first anodic oxidation treatment, an aluminum anodic oxide film 14a having micropores 16a is formed on the surface of the aluminum plate 12, as shown in FIG.

The first anodizing treatment can be performed by a method conventionally performed in this field, but manufacturing conditions are appropriately set so that the above-described micropore 16 can be finally formed.
Specifically, the average diameter (average opening diameter) of the micropores 16a formed in the first anodizing treatment step is usually about 4 to 40 nm, preferably 7 to 30 nm. If it is in the said range, the micropore 16 which has the predetermined shape mentioned above will be easy to form, and the performance of the obtained lithographic printing plate and lithographic printing plate precursor will be more excellent.
Further, the depth of the micropore 16a is usually about 5 nm or more and less than 80 nm, and preferably 15 to 60 nm. If it is in the said range, the micropore 16 which has the predetermined shape mentioned above will be easy to form, and the performance of the obtained lithographic printing plate and lithographic printing plate precursor will be more excellent.

The pore density of the micropore 16a is not particularly limited, but the pore density is preferably 50 to 4000 / μm ² , and more preferably 100 to 3000 / μm ² . Within the above range, the lithographic printing plate using the lithographic printing plate support obtained through this step is excellent in printing durability, neglectability, and on-press developability of the lithographic printing plate precursor.

Moreover, the film thickness of the anodized film obtained by a 1st anodizing process process is 10-90 nm normally, Preferably it is 15-80 nm. Within the above range, the lithographic printing plate using the lithographic printing plate support obtained through this step is excellent in printing durability, neglectability, and on-press developability of the lithographic printing plate precursor.
Furthermore, the film amount of the anodized film obtained by the first anodizing treatment step is usually 0.03 to 0.3 g / m ² , preferably 0.12 to 0.25 g / m ² . Within the above range, the lithographic printing plate using the lithographic printing plate support obtained through this step is excellent in printing durability, neglectability, and on-press developability of the lithographic printing plate precursor.

In the first anodizing treatment step, an aqueous solution of sulfuric acid, phosphoric acid, oxalic acid, or the like can be mainly used as the electrolytic solution. Depending on the case, chromic acid, sulfamic acid, benzenesulfonic acid, etc., or an aqueous solution or a non-aqueous solution combining two or more of these may be used. When a direct current or an alternating current is passed through the aluminum plate in the above electrolytic solution, an anodized film can be formed on the surface of the aluminum plate.
Note that the electrolytic solution may contain aluminum ions. Although content of aluminum ion is not specifically limited, 1-10 g / L is preferable.

The conditions for anodizing treatment are appropriately set depending on the electrolytic solution used. In general, the concentration of the electrolytic solution is 1 to 80% by mass (preferably 5 to 20% by mass), and the liquid temperature is 5 to 70 ° C. ( Preferably 10 to 60 ° C., current density 0.01 to 120 A / dm ² (preferably 0.1 to 30 A / dm ² ), voltage 1 to 100 V (preferably 10 to 80 V), electrolysis time 0.1 to 600 A range of seconds (preferably 0.5 to 300 seconds) is appropriate.

  Among these anodizing treatments, in particular, the method of anodizing at high current density in sulfuric acid described in British Patent 1,412,768, and US Pat. No. 3,511,661. A method of anodizing phosphoric acid described in the specification as an electrolytic bath is preferable.

<Pore wide processing process>
The pore wide treatment step is a treatment (pore diameter enlargement treatment) for enlarging the diameter (pore diameter) of the micropores present in the anodized film formed by the first anodizing treatment step described above. By this pore-wide treatment, as shown in FIG. 2B, the diameter of the micropore 16a is enlarged, and an anodized film 14b having the micropore 16b having a larger average diameter is formed.
By this pore wide treatment, the average diameter of the micropores 16b is expanded to a range of more than 60 nm and less than 100 nm (preferably more than 60 nm and less than 85 nm). The micropore 16b is a portion corresponding to the large-diameter hole 18 described above.
Moreover, it is preferable to adjust so that the depth from the surface of the micropore 16b may become comparable with the depth A mentioned above by this process.

  The pore-wide treatment is performed by bringing the aluminum plate obtained by the above-described first anodizing treatment step into contact with an acid aqueous solution or an alkali aqueous solution. The method of making it contact is not specifically limited, For example, the immersion method and the spray method are mentioned. Of these, the dipping method is preferred.

When an alkaline aqueous solution is used in the pore wide treatment step, it is preferable to use at least one alkaline aqueous solution selected from the group consisting of sodium hydroxide, potassium hydroxide, and lithium hydroxide. The concentration of the alkaline aqueous solution is preferably 0.1 to 5% by mass.
After adjusting the pH of the alkaline aqueous solution to 11 to 13, the aluminum plate is placed in the alkaline aqueous solution for 1 to 300 seconds (preferably 1 to 50 seconds) under the conditions of 10 to 70 ° C. (preferably 20 to 50 ° C.). ) It is appropriate to contact.
At this time, the alkali treatment liquid may contain a metal salt of a polyvalent weak acid such as carbonate, borate or phosphate.

When an aqueous acid solution is used in the pore-wide treatment step, it is preferable to use an aqueous solution of an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, or a mixture thereof. The concentration of the acid aqueous solution is preferably 1 to 80% by mass, more preferably 5 to 50% by mass.
In addition, it is appropriate that the aluminum plate is brought into contact with the acid aqueous solution for 1 to 300 seconds (preferably 1 to 150 seconds) under the condition that the temperature of the aqueous acid solution is 5 to 70 ° C. (preferably 10 to 60 ° C.).
The alkaline aqueous solution or the acidic aqueous solution may contain aluminum ions. Although content of aluminum ion is not specifically limited, 1-10 g / L is preferable.

<Second anodizing process>
The second anodizing treatment step is a step of forming micropores extending in the depth direction (thickness direction) by subjecting the aluminum plate subjected to the above-described pore wide treatment to anodizing treatment. By this second anodizing treatment step, as shown in FIG. 2C, an anodized film 14c having micropores 16c extending in the depth direction (thickness direction) is formed.
By this second anodizing treatment step, the average diameter is communicated with the bottom of the micropore 16b, the average diameter is smaller than the average diameter of the micropore 16b (corresponding to the large diameter hole 18), and the depth from the communicating position. A new hole extending in the direction is formed. The hole corresponds to the small diameter hole 20 described above.

In the second anodizing treatment step, a new hole portion (small-diameter hole) in which the average diameter is greater than 0 and less than 15 nm and the depth from the communication position with the bottom of the large-diameter hole portion 18 is within the predetermined range described above. The process is carried out so that part 20) is formed. The electrolytic bath used for the treatment is the same as that in the first anodizing treatment step, and the treatment conditions are appropriately set according to the material used.
The conditions for anodizing treatment are appropriately set depending on the electrolytic solution used. In general, the concentration of the electrolytic solution is 1 to 80% by mass (preferably 5 to 20% by mass), and the liquid temperature is 5 to 70 ° C. ( Preferably 10 to 60 ° C., current density 0.5 to 60 A / dm ² (preferably 1 to 30 A / dm ² ), voltage 1 to 100 V (preferably 5 to 50 V), electrolysis time 1 to 100 seconds (preferably The range of 5 to 60 seconds is appropriate.

The film thickness of the anodized film obtained by the second anodizing treatment step is usually 900 to 2000 nm, preferably 900 to 1500 nm. Within the above range, the lithographic printing plate using the lithographic printing plate support obtained through this step is excellent in printing durability, neglectability, and on-press developability of the lithographic printing plate precursor.
Moreover, the film amount of the anodized film obtained by the second anodizing treatment step is usually 2.2 to 5.4 g / m ² , preferably 2.2 to 4.0 g / m ² . Within the above range, the lithographic printing plate using the lithographic printing plate support obtained through this step is excellent in printing durability, neglectability, and on-press developability of the lithographic printing plate precursor.

  Ratio (film thickness 1 / film thickness) of the thickness of the anodized film obtained by the first anodizing process (film thickness 1) and the thickness of the anodized film obtained by the second anodizing process (film thickness 2) 2) is preferably 0.002 to 0.05, and more preferably 0.02 to 0.05. Within the above range, the lithographic printing plate support is excellent in scratch resistance.

<Preferred embodiment of anodizing treatment>
As a preferred embodiment of the above-described first anodizing treatment, there is a method in which a solution containing phosphoric acid or oxalic acid (preferably phosphoric acid) is used as an electrolytic bath. By performing the treatment, a lithographic printing plate having excellent printing durability and a lithographic printing plate precursor having excellent on-press developability can be obtained.
A mechanism for obtaining the effect will be described in detail with reference to FIG.
By anodizing with a solution containing phosphoric acid or oxalic acid, it is possible to form an anodized film whose pore diameter increases in the film thickness direction. Further, by immersing such an anodized film in an acid / alkali bath and dissolving the anodized film, a micropore shape as shown in FIG. 3B can be formed. Compared with the anodized film in which the pore diameter does not increase in the film thickness direction, the micropore shape can increase the pore density at the same average pore diameter, and the printing durability can be increased.

  As shown in FIG. 3A, when an anodizing treatment is performed using an electrolytic bath containing phosphoric acid or oxalic acid, an aluminum anodic oxide film 14d having micropores 16d is formed on the surface of the aluminum plate 12. The The shape of the formed micropore 16d is different from the case where other electrolytic baths are used, as shown in the figure, and has a shape in which the inner diameter is wider than the opening diameter.

Next, by performing the pore wide process described above, the diameter of the micropore 16d is enlarged, and an anodized film 14e having the micropore 16e having a larger average diameter is formed (see FIG. 3B).
Furthermore, by performing the above-described second anodizing treatment, an anodized film 14f having micropores 16f extending in the depth direction (thickness direction) is formed (see FIG. 3C).

  By performing the first anodic oxidation treatment using phosphoric acid or oxalic acid in this way, printing durability, on-press development property, and neglectability compared with the case where other electrolytic baths (for example, sulfuric acid) are used. Thus, it is possible to form micropores having a suitable shape (the shape of the large diameter portion is substantially hemispherical).

That is, by using the lithographic printing plate support obtained by the mechanism shown in FIG. 3, it is possible to obtain a lithographic printing plate and a lithographic printing plate precursor exhibiting superior printing durability, on-press development property, neglectability, etc. it can.
In other words, a first anodizing treatment step in which an aluminum plate is anodized using a solution containing phosphoric acid and oxalic acid, and an aluminum plate having an anodized film obtained in the first anodizing treatment step is converted into an acid aqueous solution. Alternatively, a manufacturing method comprising a pore-wide treatment step in which the micropore diameter in the anodized film is increased by contacting with an alkaline aqueous solution, and a second anodization treatment step in which the aluminum plate obtained in the pore-wide treatment step is anodized The lithographic printing plate support obtained by the above exhibits excellent invention effects.

<Hydrophilic treatment process>
The method for producing a lithographic printing plate support of the present invention may have a hydrophilic treatment step for carrying out a hydrophilic treatment after the second anodizing treatment step described above. As the hydrophilization treatment, a known method disclosed in paragraphs [0109] to [0114] of JP-A-2005-254638 can be used.

  Hydrophilization by a method of immersing in an aqueous solution of an alkali metal silicate such as sodium silicate or potassium silicate, or a method of forming a hydrophilic undercoat layer by applying a hydrophilic vinyl polymer or hydrophilic compound. 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.

  On the other hand, the support for a lithographic printing plate of the present invention is preferably a support for a lithographic printing plate obtained by subjecting the above-described aluminum plate to the treatments shown in the following A mode in the order shown below. In addition, it is desirable to perform water washing between the following processes. However, when two steps (processes) to be performed in succession use a liquid having the same composition, washing with water may be omitted.

(A mode)
(1) Mechanical roughening treatment (2) Chemical etching treatment in alkaline aqueous solution (first alkali etching treatment)
(3) Chemical etching treatment in acidic aqueous solution (first desmutting treatment)
(4) Electrochemical roughening treatment in an aqueous solution mainly composed of nitric acid (first electrochemical roughening treatment)
(5) Chemical etching treatment in an aqueous alkali solution (second alkali etching treatment)
(6) Chemical etching treatment in acidic aqueous solution (second desmut treatment)
(7) Electrochemical roughening treatment in an aqueous solution mainly composed of hydrochloric acid (second electrochemical roughening treatment)
(8) Chemical etching treatment in an alkaline aqueous solution (third alkali etching treatment)
(9) Chemical etching treatment in acidic aqueous solution (third desmut treatment)
(10) Anodizing treatment (11) Hydrophilization treatment

  Here, the mechanical surface roughening treatment, electrochemical surface roughening treatment, chemical etching treatment, anodizing treatment and hydrophilization treatment in the above (1) to (11) are the same as the above-described treatment methods and conditions. However, the treatment is preferably performed under the treatment method and conditions described below.

The mechanical roughening treatment is preferably mechanically roughened with a rotating nylon brush roll having a bristle diameter of 0.2 to 1.61 mm and a slurry liquid supplied to the aluminum plate surface.
Although a well-known thing can be used as an abrasive | polishing agent, quartz sand, quartz, aluminum hydroxide, or a mixture thereof is preferable.
The specific gravity of the slurry liquid is preferably 1.05 to 1.3. Of course, a method of spraying a slurry liquid, a method of using a wire brush, a method of transferring the surface shape of an uneven rolling roll to an aluminum plate, or the like may be used.

The concentration of the alkaline aqueous solution used for the chemical etching treatment in the alkaline aqueous solution is preferably 1 to 30% by mass, and the alloy component contained in the aluminum alloy as well as aluminum may contain 0 to 10% by mass.
As the alkaline aqueous solution, an aqueous solution mainly composed of caustic soda is particularly preferable. The liquid temperature is preferably from room temperature to 95 ° C., and the treatment is preferably performed for 1 to 120 seconds.
After the etching process is completed, it is preferable to perform liquid draining with a nip roller and water washing with a spray so as not to bring the processing liquid into the next process.

Dissolution amount of the aluminum plate in the first alkali etching treatment is preferably from 0.5 to 30 g / m ^2, more preferably from ^{1.0~20g / m 2, 3.0~15g / m} 2 More preferably.
Dissolution amount of the aluminum plate in the second alkali etching treatment is preferably 0.001~30g / m ^2, more preferably from 0.1-4 g / m ^2, 0.2 to 1.5 g / even more preferably in the range of m ^2.
Dissolution amount of the aluminum plate in the third alkali etching treatment is preferably 0.001~30g / m ^2, more preferably from 0.01~0.8g / m ^2, 0.02~0. More preferably, it is 3 g / m ² .

In chemical etching treatment (first to third desmutting treatment) in an acidic aqueous solution, phosphoric acid, nitric acid, sulfuric acid, chromic acid, hydrochloric acid, or a mixed acid containing two or more acids thereof is preferably used.
The concentration of the acidic aqueous solution is preferably 0.5 to 60% by mass.
Further, in the acidic aqueous solution, 0 to 5% by mass of the alloy component contained in the aluminum alloy as well as aluminum may be dissolved.
The liquid temperature is from room temperature to 95 ° C., and the treatment time is preferably 1 to 120 seconds. After the desmut treatment is completed, it is preferable to carry out liquid removal by a nip roller and water washing by spraying in order not to bring the treatment liquid into the next process.

The aqueous solution used for the electrochemical surface roughening treatment will be described.
The aqueous solution mainly composed of nitric acid used in the first electrochemical surface roughening treatment can be one used for an electrochemical surface roughening treatment using ordinary direct current or alternating current, and an aqueous nitric acid solution of 1 to 100 g / L. One or more of hydrochloric acid or nitric acid compound having nitric acid ions such as aluminum nitrate, sodium nitrate and ammonium nitrate; hydrochloric acid ions such as aluminum chloride, sodium chloride and ammonium chloride; be able to.
Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, and a silica, may melt | dissolve in the aqueous solution which has nitric acid as a main component.
Specifically, it is preferable to use a solution in which aluminum chloride and aluminum nitrate are added so that aluminum ions are 3 to 50 g / L in a 0.5 to 2 mass% nitric acid aqueous solution.
The temperature is preferably 10 to 90 ° C, more preferably 40 to 80 ° C.

On the other hand, the aqueous solution mainly composed of hydrochloric acid used in the second electrochemical surface roughening treatment can be one used for an electrochemical surface roughening treatment using normal direct current or alternating current, and has an amount of 1 to 100 g / L. One or more of hydrochloric acid or nitric acid compound having nitric acid ions such as aluminum nitrate, sodium nitrate and ammonium nitrate; hydrochloric acid ions such as aluminum chloride, sodium chloride and ammonium chloride; Can be used.
Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, and a silica, may melt | dissolve in the aqueous solution which has hydrochloric acid as a main component.
Specifically, it is preferable to use a solution in which aluminum chloride and aluminum nitrate are added so that the aluminum ion is 3 to 50 g / L in an aqueous solution of 0.5 to 2% by mass of hydrochloric acid.
Moreover, 10-60 degreeC is preferable and 20-50 degreeC is more preferable. Hypochlorous acid may be added.

  A sine wave, a rectangular wave, a trapezoidal wave, a triangular wave, or the like can be used as the AC power supply waveform for the electrochemical roughening treatment. The frequency is preferably 0.1 to 250 Hz.

FIG. 4 is a graph showing an example of an alternating waveform current waveform diagram used for an electrochemical roughening treatment in the method for producing a lithographic printing plate support of the present invention.
In FIG. 4, ta is the anode reaction time, tc is the cathode reaction time, tp is the time until the current reaches the peak from 0, Ia is the peak current on the anode cycle side, and Ic is the peak current on the cathode cycle side. It is. In the trapezoidal wave, the time tp until the current reaches a peak from 0 is preferably 1 to 10 msec. Due to the influence of the impedance of the power supply circuit, if tp is less than 1, a large power supply voltage is required at the rise of the current waveform, and the equipment cost of the power supply increases. When it is longer than 10 msec, it is easily affected by a trace component in the electrolytic solution, and uniform surface roughening is difficult to be performed. The condition of one cycle of alternating current used for electrochemical surface roughening is that the ratio tc / ta of the anode reaction time ta to the cathode reaction time tc of the aluminum plate is 1 to 20, the quantity of electricity Qc when the aluminum plate is anode and the anode It is preferable that the ratio Qc / Qa of the amount of electricity Qa is 0.3 to 20 and the anode reaction time ta is 5 to 1000 msec. tc / ta is more preferably 2.5 to 15. Qc / Qa is more preferably 2.5 to 15. The current density is preferably a trapezoidal wave peak value of 10 to 200 A / dm ² for both the anode cycle side Ia and the cathode cycle side Ic of the current. Ic / Ia is preferably in the range of 0.3-20. The total amount of electricity furnished to anode reaction of the aluminum plate at the time the electrochemical graining is completed, 25~1000C / dm ² is preferred.

  In the present invention, as an electrolytic cell used for electrochemical surface roughening using alternating current, known electrolytic cells such as vertical, flat and radial types can be used. A radial electrolytic cell as described in Japanese Patent No. 195300 is particularly preferred.

The apparatus shown in FIG. 5 can be used for electrochemical surface roughening using alternating current.
FIG. 5 is a side view showing an example of a radial type cell in an electrochemical surface roughening treatment using alternating current in the method for producing a lithographic printing plate support of the present invention.
In FIG. 5, 50 is a main electrolytic cell, 51 is an AC power source, 52 is a radial drum roller, 53a and 53b are main electrodes, 54 is an electrolyte supply port, 55 is an electrolyte, 56 is a slit, 57 is an electrolyte passage, 58 is an auxiliary anode, 60 is an auxiliary anode tank, and W is an aluminum plate. When two or more electrolytic cells are used, the electrolysis conditions may be the same or different.
The aluminum plate W is wound around a radial drum roller 52 disposed so as to be immersed in the main electrolytic cell 50, and is subjected to electrolytic treatment by main electrodes 53a and 53b connected to the AC power source 51 in the course of conveyance. The electrolytic solution 55 is supplied from the electrolytic solution supply port 54 to the electrolytic solution passage 57 between the radial drum roller 52 and the main poles 53a and 53b through the slit 56. The aluminum plate W treated in the main electrolytic cell 50 is then subjected to electrolytic treatment in the auxiliary anode cell 60. An auxiliary anode 58 is disposed opposite to the aluminum plate W in the auxiliary anode tank 60, and the electrolytic solution 55 is supplied so as to flow in the space between the auxiliary anode 58 and the aluminum plate W.

  On the other hand, in the electrochemical surface roughening process (first and second electrochemical surface roughening processes), a direct current is applied between the aluminum plate and the electrode facing the aluminum plate to electrochemically roughen the surface. There may be.

<Drying process>
After obtaining the lithographic printing plate support obtained by the steps described above, it is preferable to perform a treatment (drying step) for drying the surface of the lithographic printing plate support before providing an image recording layer described later.
Drying is preferably performed after the final treatment of the surface treatment, after washing with water and draining with a nip roller. Although it does not restrict | limit especially as specific conditions, It is preferable to dry with a hot air (50-200 degreeC) or a cold-air natural drying method.

<Lithographic printing plate precursor>
The lithographic printing plate support of the present invention can be provided with an image recording layer such as a photosensitive layer or a heat-sensitive layer to form the lithographic printing plate precursor of the present invention. The image recording layer is not particularly limited. For example, the conventional positive type, the conventional negative type, the photopolymer type, the thermal positive type, and the thermal negative type described in paragraphs [0042] to [0198] of JP-A-2003-1956. A non-processing type that can be developed on the machine is preferable.
Hereinafter, a suitable image recording layer will be described in detail.

<Image recording layer>
A preferred image recording layer that can be used in the lithographic printing plate precursor according to the present invention is a layer that can be removed by printing ink and / or fountain solution. Specifically, an infrared absorber, a polymerization initiator, The image recording layer preferably has a polymerizable compound and can be recorded by infrared irradiation.
In the lithographic printing plate precursor of the present invention, the exposed portion of the image recording layer is cured by infrared irradiation to form a hydrophobic (lipophilic) region, and the unexposed portion is dampened with water, ink or ink at the start of printing. It is quickly removed from the support by an emulsion of fountain solution and ink.
Hereinafter, each component of the image recording layer will be described.

(Infrared absorber)
When forming an image of the lithographic printing plate precursor according to the present invention using a laser emitting infrared rays of 760 to 1200 nm as a light source, an infrared absorber is usually used.
The infrared absorber has a function of converting the absorbed infrared ray into heat and a function of being excited by the infrared ray and transferring electrons / energy to a polymerization initiator (radical generator) described later.
The infrared absorbent that can be used in the present invention is a dye or pigment having an absorption maximum at a wavelength of 760 to 1200 nm.

As the dye, commercially available dyes, for example, known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used.
Specifically, dyes such as 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, etc. Is mentioned. Further, cyanine dyes and indolenine cyanine dyes are preferred, and particularly preferred examples include cyanine dyes represented by the following general formula (a).

In the general formula (a), X ¹ represents a hydrogen atom, a halogen ^{atom, -N (R 9) (R} 10), - X ² -L ¹ or a group shown below. Here, R ⁹ and R ¹⁰ may be the same or different and each may have a substituent, an aryl group having 6 to 10 carbon atoms, an alkyl group having 1 to 8 carbon atoms, a hydrogen atom R ⁹ and R ¹⁰ may be bonded to each other to form a ring. Of these, a phenyl group is preferred (—NPh ₂ ). X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, a heteroaryl group, or a hydrocarbon group having 1 to 12 carbon atoms including a hetero atom. In addition, a hetero atom here shows N, S, O, a halogen atom, and Se. In the groups shown below, Xa- is defined in the same manner as Za- described later, and Ra represents a substituent selected from a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, and a halogen atom.

R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. In view of storage stability of the image recording layer coating solution, R ¹ and R ² are preferably hydrocarbon groups having 2 or more carbon atoms. R ¹ and R ² may be connected to each other to form a ring. When forming a ring, it is particularly preferable that a 5-membered ring or a 6-membered ring is formed.

Ar ¹ and Ar ² may be the same or different and each represents an aryl group which may have a substituent. Preferred aryl groups include a benzene ring and a naphthalene ring. Moreover, as a preferable substituent, a C12 or less hydrocarbon group, a halogen atom, and a C12 or less alkoxy group are mentioned. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxy groups, and sulfo groups. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred. Za ⁻ represents a counter anion. However, Za- is not necessary when the cyanine dye represented by the general formula (a) has an anionic substituent in its structure and neutralization of charge is not necessary. Preferred Za ⁻ is a halide ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, in view of the storage stability of the image recording layer coating solution. , Hexafluorophosphate ions, and aryl sulfonate ions.

  Specific examples of the cyanine dye represented by formula (a) that can be suitably used include compounds described in paragraphs [0017] to [0019] of JP-A No. 2001-133969, JP-A No. 2002-023360. Paragraphs [0016] to [0021] of JP-A No. 2002-040638, paragraphs [0012] to [0037] of JP-A No. 2002-040638, preferably JP-A Nos. 2002-278057 [0034] to [0041] and JP-A No. 2008. 195018 [0080] to [0086], particularly preferably compounds described in JP-A 2007-90850 [0035] to [0043]. In addition, compounds described in paragraphs [0008] to [0009] of JP-A No. 5-5005 and paragraphs [0022] to [0025] of JP-A No. 2001-222101 can also be preferably used.

  Moreover, only 1 type may be used for these (B) infrared absorption dyes, 2 or more types may be used together, and infrared absorbers other than infrared absorption dyes, such as a pigment, may be used together. As the pigment, compounds described in JP 2008-195018 A [0072] to [0076] are preferable.

  The content of the infrared absorbing dye in the image recording layer in the present invention is preferably 0.1 to 10.0% by mass, more preferably 0.5 to 5.0% by mass of the total solid content of the image recording layer. .

(Polymerization initiator)
The polymerization initiator is a compound that generates radicals by energy of light, heat, or both, and initiates and accelerates polymerization of a compound having a polymerizable unsaturated group. In the present invention, it generates radicals by heat. It is preferable to use a compound (thermal radical generator).
As the polymerization initiator, a known thermal polymerization initiator, a compound having a bond with a small bond dissociation energy, a photopolymerization initiator, or the like can be used.
As the polymerization initiator, for example, polymerization initiators described in paragraphs [0115] to [0141] of JP-A-2009-255434 can be used.

  In addition, an onium salt etc. can be used as a polymerization initiator, and the said oxime ester compound or a diazonium salt, an iodonium salt, and a sulfonium salt are mentioned suitably from the surface of reactivity and stability.

  These polymerization initiators are added in a proportion of 0.1 to 50% by mass, preferably 0.5 to 30% by mass, particularly preferably 1 to 20% by mass, based on the total solid content constituting the image recording layer. Can do. Within this range, good sensitivity and good stain resistance of the non-image area during printing can be obtained.

(Polymerizable compound)
The polymerizable compound is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and is selected from compounds having at least one, preferably two or more terminal ethylenically unsaturated bonds. In the present invention, those compounds widely known in the technical field of the present invention can be used without any particular limitation.
As the polymerizable compound, for example, polymerizable compounds exemplified in paragraphs [0142] to [0163] of JP-A-2009-255434 can be used.

  Also suitable are urethane-based addition polymerizable compounds produced by the addition reaction of isocyanate and hydroxyl groups. Specific examples thereof include a vinyl monomer containing a hydroxyl group represented by the following general formula (A) in a polyisocyanate compound having two or more isocyanate groups per molecule described in JP-B-48-41708. And vinyl urethane compounds containing two or more polymerizable vinyl groups in one molecule to which is added.

^{_{CH 2 = C (R 4)}} COOCH 2 CH (R 5) OH (A)
(However, R ⁴ and R ⁵ represent H or CH _3. )

  The polymerizable compound is used in an amount of preferably 5 to 80% by mass, more preferably 25 to 75% by mass, based on the nonvolatile component in the image recording layer. These may be used alone or in combination of two or more.

(Binder polymer)
In the present invention, a binder polymer can be used for the image recording layer in order to improve the film forming property of the image recording layer.
Conventionally known binder polymers can be used without limitation, and polymers having film properties are preferred. Specifically, as such a binder polymer, for example, acrylic resin, polyvinyl acetal resin, polyurethane resin, polyurea resin, polyimide resin, polyamide resin, epoxy resin, methacrylic resin, polystyrene resin, novolac phenolic resin, Polyester resin, synthetic rubber, natural rubber and the like can be mentioned.
The binder polymer may have crosslinkability in order to improve the film strength of the image area. In order to impart crosslinkability to the binder polymer, a crosslinkable functional group such as an ethylenically unsaturated bond may be introduced into the main chain or side chain of the polymer. The crosslinkable functional group may be introduced by copolymerization.
As the binder polymer, for example, binder polymers disclosed in paragraphs [0165] to [0172] of JP-A-2009-255434 can be used.

The content of the binder polymer is 5 to 90% by mass, preferably 5 to 80% by mass, and more preferably 10 to 70% by mass with respect to the total solid content of the image recording layer. Within this range, good image area strength and image formability can be obtained.
Moreover, it is preferable to use a polymeric compound and a binder polymer in the quantity used as 0.5 / 1-4/1 by mass ratio.

(Surfactant)
In the image recording layer, it is preferable to use a surfactant in order to promote on-press developability at the start of printing and to improve the coated surface state.
Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and fluorosurfactants.
As the surfactant, for example, surfactants disclosed in paragraphs [0175] to [0179] of JP-A-2009-255434 can be used.

Surfactant can be used individually or in combination of 2 or more types.
The content of the surfactant is preferably 0.001 to 10% by mass and more preferably 0.01 to 5% by mass with respect to the total solid content of the image recording layer.

  In addition to these, various compounds may be added to the image recording layer as necessary. For example, colorants, print-out agents, polymerization inhibitors, higher fatty acid derivatives, plasticizers, inorganic fine particles, low molecular weight hydrophilic compounds and the like disclosed in paragraphs [0181] to [0190] of JP-A-2009-255434 are disclosed. Can be mentioned.

<Formation of image recording layer>
The image recording layer is formed by preparing a coating solution by dispersing or dissolving the necessary components described above in a solvent and then coating the coating solution on a support. Here, as a solvent to be used, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, Although water etc. can be mentioned, it is not limited to this.
These solvents are used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by mass.

Further, coating amount of the image-recording layer on the lithographic printing plate support obtained after drying (solid content) may be varied according to the intended purpose, generally 0.3 to 3.0 g / m ² is preferred. Within this range, good sensitivity and good film characteristics of the image recording layer can be obtained.
Examples of the coating method include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

<Undercoat layer>
In the lithographic printing plate precursor according to the invention, it is desirable to provide an undercoat layer between the image recording layer and the lithographic printing plate support described above.

The undercoat layer preferably contains a polymer having a substrate adsorptive group, a polymerizable group, and a hydrophilic group.
As the polymer having a substrate adsorptive group, a polymerizable group and a hydrophilic group, a monomer having an adsorptive group, a monomer having a hydrophilic group, and a monomer having a polymerizable reactive group (crosslinkable group) were copolymerized. Mention may be made of polymer resins for undercoat layers.
Examples of the monomer that can be used in the polymer resin for the undercoat layer include monomers described in paragraphs [0197] to [0210] of JP-A-2009-255434.

Various known methods can be used as a method of applying the undercoat layer coating solution containing the constituent material of the undercoat layer to the support. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.
The coating amount (solid content) of the undercoat layer is preferably from 0.1-100 mg / m ^2, and more preferably 1 to 50 mg / m ^2.

<Protective layer>
In the lithographic printing plate precursor according to the present invention, a protective layer is provided on the image recording layer as necessary in order to prevent the occurrence of scratches in the image recording layer, to block oxygen, and to prevent ablation during high-illuminance laser exposure. Can do.
The protective layer is described in detail in, for example, US Pat. No. 3,458,311 and Japanese Patent Publication No. 55-49729.
As a material used for the protective layer, for example, materials described in paragraphs [0213] to [0227] of JP-A-2009-255434 (water-soluble polymer compound, inorganic layered compound, etc.) are used. be able to.

  The prepared protective layer coating solution is applied onto the image recording layer provided on the support and dried to form a protective layer. The coating solvent can be appropriately selected in relation to the binder, but when a water-soluble polymer is used, it is preferable to use distilled water or purified water. The coating method of the protective layer is not particularly limited, and examples thereof include a blade coating method, an air knife coating method, a gravure coating method, a roll coating coating method, a spray coating method, a dip coating method, and a bar coating method.

The coating amount of the protective layer, the coating amount after drying is preferably in the range of 0.01 to 10 g / m ^2, more preferably in the range of 0.02 to 3 g / m ^2, and most preferably 0. It is in the range of 02 to 1 g / m ² .

  The lithographic printing plate precursor of the present invention having the image recording layer as described above exhibits excellent neglectability and printing durability when used as a lithographic printing plate, while in-machine development type exhibits on-machine developability. An improved lithographic printing plate precursor.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

<Manufacture of lithographic printing plate support>
The following treatments (a) to (m) were applied to an aluminum alloy plate of material 1S having a thickness of 0.3 mm to produce a planographic printing plate support. In addition, the water washing process was performed between all the process steps, and the liquid draining was performed with the nip roller after the water washing process.

(A) Mechanical roughening treatment (brush grain method)
Using an apparatus as shown in FIG. 6, while supplying a suspension of pumice (specific gravity: 1.1 g / cm ³ ) as a polishing slurry liquid to the surface of the aluminum plate, a mechanical rough surface by a rotating bundle-planting brush The treatment was performed. In FIG. 6, 1 is an aluminum plate, 2 and 4 are roller-like brushes (bundling brushes in this embodiment), 3 is an abrasive slurry, and 5, 6, 7 and 8 are support rollers.
In the mechanical surface roughening treatment, the median diameter (μm) of the abrasive was 30 μm, the number of brushes was 4, and the number of rotations (rpm) of the brushes was 250 rpm. The material of the bunch planting brush was 6 · 10 nylon, with a bristle diameter of 0.3 mm and a bristle length of 50 mm. The brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. The distance between the two support rollers (φ200 mm) at the bottom of the bundle-planting brush was 300 mm. The bundle brush was pressed until the load of the drive motor for rotating the brush became 10 kW plus with respect to the load before the bundle brush was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate.

(B) Alkaline etching treatment The aluminum plate obtained above was etched by spraying a caustic soda aqueous solution having a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass% with a spray tube at a temperature of 70 ° C. Then, water washing by spraying was performed. The amount of aluminum dissolved was 10 g / m ² .

(C) Desmutting treatment in acidic aqueous solution Next, desmutting treatment was performed in an aqueous nitric acid solution. The nitric acid aqueous solution used for the desmut treatment was a nitric acid waste solution used for electrochemical roughening in the next step. The liquid temperature was 35 ° C. The desmutting liquid was sprayed and sprayed for 3 seconds.

(D) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of nitric acid electrolysis 60 Hz. As the electrolytic solution at this time, an electrolytic solution in which aluminum nitrate was adjusted to 4.5 g / L by adding aluminum nitrate to an aqueous solution having a temperature of 35 ° C. and nitric acid of 10.4 g / L was used. The AC power supply waveform is the waveform shown in FIG. 4. The time tp until the current value reaches a peak from zero is 0.8 msec, the duty ratio is 1: 1, and a trapezoidal rectangular wave AC is used with the carbon electrode as the counter electrode. An electrochemical roughening treatment was performed. Ferrite was used for the auxiliary anode. The electrolytic cell shown in FIG. 5 was used. The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode. Amount of electricity (C / dm ²⁾ the aluminum plate was 185C / dm ² as the total quantity of electricity when the anode. Then, water washing by spraying was performed.

(E) Alkaline etching treatment The aluminum plate obtained above was etched by spraying an aqueous caustic soda solution having a caustic soda concentration of 5 mass% and an aluminum ion concentration of 0.5 mass% with a spray tube at a temperature of 50C. Then, water washing by spraying was performed. The amount of dissolved aluminum was 0.5 g / m ² .

(F) Desmutting treatment in acidic aqueous solution Next, desmutting treatment was performed in an aqueous sulfuric acid solution. The sulfuric acid aqueous solution used for the desmut treatment was a solution having a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L. The liquid temperature was 60 ° C. The desmutting liquid was sprayed and sprayed for 3 seconds.

(G) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of hydrochloric acid electrolysis 60 Hz. As the electrolytic solution, an electrolytic solution in which aluminum chloride was adjusted to 4.5 g / L by adding aluminum chloride to an aqueous solution having a liquid temperature of 35 ° C. and hydrochloric acid of 6.2 g / L was used. The AC power supply waveform is the waveform shown in FIG. 4. The time tp until the current value reaches a peak from zero is 0.8 msec, the duty ratio is 1: 1, and a trapezoidal rectangular wave AC is used with the carbon electrode as the counter electrode. An electrochemical roughening treatment was performed. Ferrite was used for the auxiliary anode. The electrolytic cell shown in FIG. 5 was used.
The current density was 25A / dm ² at the peak of electric current amount of hydrochloric acid electrolysis (C / dm ²⁾ the aluminum plate was 63C / dm ² as the total quantity of electricity when the anode. Then, water washing by spraying was performed.

(H) Alkaline etching treatment The aluminum plate obtained above was etched by spraying a caustic soda aqueous solution having a caustic soda concentration of 5 mass% and an aluminum ion concentration of 0.5 mass% with a spray tube at a temperature of 50C. Then, water washing by spraying was performed. The amount of aluminum dissolved was 0.1 g / m ² .

(I) Desmutting treatment in acidic aqueous solution Next, desmutting treatment was performed in an aqueous sulfuric acid solution. Specifically, desmutting treatment was performed for 4 seconds at a liquid temperature of 35 ° C. using the waste liquid generated in the anodizing treatment step (dissolving 5 g / L of aluminum ions in a 170 g / L aqueous solution of sulfuric acid). The desmutting liquid was sprayed and sprayed for 3 seconds.

(J) First stage anodizing treatment The first stage anodizing treatment was performed using a direct current electrolysis anodizing apparatus having the structure shown in FIG. Anodization was performed under the conditions shown in Table 1 to form an anodized film having a predetermined film thickness. An aqueous solution of sulfuric acid, phosphoric acid, and oxalic acid was used as the electrolytic solution.
In the anodizing apparatus 610, the aluminum plate 616 is transported as indicated by arrows in FIG. The aluminum plate 616 is charged (+) by the power supply electrode 620 in the power supply tank 612 in which the electrolytic solution 618 is stored. Then, the aluminum plate 616 is conveyed upward by the roller 622 in the power supply tank 612, and the direction is changed downward by the nip roller 624. Then, the aluminum plate 616 is conveyed toward the electrolytic treatment tank 614 in which the electrolytic solution 626 is stored, and by the roller 628. The direction is changed horizontally. Next, the aluminum plate 616 is charged to (−) by the electrolytic electrode 630 to form an anodized film on the surface thereof, and the aluminum plate 616 exiting the electrolytic treatment tank 614 is transported to a subsequent process. In the anodizing apparatus 610, the direction changing means is constituted by the roller 622, the nip roller 624 and the roller 628, and the aluminum plate 616 is disposed between the power supply tank 612 and the electrolytic treatment tank 614 between the rollers 622, 624 and 628. Thus, it is conveyed into a mountain shape and an inverted U shape. The feeding electrode 620 and the electrolytic electrode 630 are connected to a DC power source 634.

(K) Pore-wide treatment The above-mentioned anodized aluminum plate was immersed in an aqueous caustic soda solution having a temperature of 35 ° C., a caustic soda concentration of 5 mass%, and an aluminum ion concentration of 0.5 mass%, and the pore-wide treatment was performed. It was. Then, water washing by spraying was performed.

(L) Second stage anodizing treatment The second stage anodizing treatment was performed using a direct current electrolysis anodizing apparatus having the structure shown in FIG. Anodization was performed under the conditions shown in Table 1 to form an anodized film having a predetermined film thickness. An aqueous solution of sulfuric acid was used as the electrolytic solution.

(M) Silicate treatment In order to ensure the hydrophilicity of the non-image area, a silicate treatment was performed by dipping at 50 ° C. for 7 seconds using a 2.5 mass% No. 3 sodium silicate aqueous solution. The adhesion amount of Si was 8.5 mg / m ² . Then, water washing by spraying was performed.

(L) The average diameter of the large-diameter hole portion in the anodized film having micropores after the second anodizing treatment step, the average diameter at the communication position of the small-diameter hole portion, and the depth, Table 2 summarizes the results.
The average diameter of the micropores (average diameter of the large-diameter hole portion and the small-diameter hole portion) was obtained by observing N = 4 sheets of the support surface (anodized film surface) with an FE-SEM at a magnification of 150,000 times. In these four images, the diameters of the micropores (large diameter holes and small diameter holes) existing in the range of 400 × 600 nm ² were measured and averaged.
In addition, the depth of the micropore (depth of the large-diameter hole portion and the small-diameter hole portion) is obtained by observing the cross section of the support (anodized film) with an FE-SEM at a magnification of 150,000 times. It is a value obtained by measuring and averaging the depths of 25 arbitrary micropores.

  In Examples 1 to 31, micropores having a predetermined average diameter and depth were formed in the anodized film of aluminum.

<Manufacture of lithographic printing plate precursor>
The following undercoat liquid was applied to each lithographic printing plate support produced above so that the dry coating amount was 28 mg / m ² , thereby providing an undercoat layer.

<Coating liquid for undercoat layer>
-Undercoat layer compound (1) having the following structure: 0.18 g
・ Hydroxyethyliminodiacetic acid 0.10g
・ Methanol 55.24g
・ Water 6.15g

Next, the image recording layer coating solution is bar-coated on the undercoat layer formed as described above, and then oven-dried at 100 ° C. for 60 seconds to form an image recording layer having a dry coating amount of 1.3 g / m ^2. did.
All the image recording layer coating solutions were obtained by mixing and stirring the respective photosensitive solutions and microgel solutions immediately before coating.

<Photosensitive solution>
-Binder polymer (1) [the following structure] 0.24 g
Infrared absorber (1) [the following structure] 0.030 g
-Radical polymerization initiator (1) [the following structure] 0.162 g
Polymerizable compound Tris (acryloyloxyethyl) isocyanurate (NK ester A-9300, manufactured by Shin-Nakamura Chemical Co., Ltd.) 0.192 g
・ Low molecular weight hydrophilic compound tris (2-hydroxyethyl) isocyanurate
0.062g
・ Low molecular weight hydrophilic compound (1) [the following structure] 0.052 g
-Sensitizing agent Phosphonium compound (1) [the following structure] 0.055 g
・ Sensitizer Benzyl-dimethyl-octylammonium ・ PF ₆ salt 0.018g
-Betaine derivative (C-1) 0.010 g
Fluorine-based surfactant (1) (average weight molecular weight: 10,000) [the following structure] 0.008 g
・ Methyl ethyl ketone 1.091g
・ 1-methoxy-2-propanol 8.609g

<Microgel solution>
・ Microgel (1) 2.640 g
・ Distilled water 2.425g

  The structures of the binder polymer (1), the infrared absorber (1), the radical polymerization initiator (1), the phosphonium compound (1), the low molecular weight hydrophilic compound (1) and the fluorine-based surfactant (1) are as follows: It is as shown below.

  The microgel (1) described above is synthesized as follows.

<Synthesis of Microgel (1)>
As oil phase components, trimethylolpropane and xylene diisocyanate adduct (Takenate D-110N, manufactured by Mitsui Takeda Chemical Co., Ltd.) 10 g, pentaerythritol triacrylate (SR444, manufactured by Nippon Kayaku Co., Ltd.) 3.15 g, and Pionein A- 0.1 g of 41C (manufactured by Takemoto Yushi Co., Ltd.) was dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4% by mass aqueous solution of PVA-205 was prepared. The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12,000 rpm using a homogenizer. The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 50 ° C. for 3 hours. The microgel solution thus obtained was diluted with distilled water to a solid content concentration of 15% by mass, and this was used as the microgel (1). When the average particle size of the microgel was measured by a light scattering method, the average particle size was 0.2 μm.

Then, a protective layer coating solution having the following composition was further bar-coated on the image recording layer formed as described above, and then oven-dried at 120 ° C. for 60 seconds to provide a dry coating amount of 0.15 g / m ² . A layer was formed to obtain a lithographic printing plate precursor.

<Coating liquid for protective layer>
・ Inorganic layered compound dispersion (1) 1.5 g
-Polyvinyl alcohol (CKS50, sulfonic acid modification, saponification degree 99 mol% or more, polymerization degree 300, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 6% by mass aqueous solution 0.55 g
-Polyvinyl alcohol (PVA-405, saponification degree 81.5 mol%, polymerization degree 500, Kuraray Co., Ltd.) 6 mass% aqueous solution 0.03g
-1% by weight aqueous solution of surfactant (Emalex 710, manufactured by Nippon Emulsion)
8.60g
・ Ion-exchanged water 6.0g

  The inorganic layered compound dispersion (1) described above is prepared as follows.

(Preparation of inorganic layered compound dispersion (1))
6.4 g of synthetic mica Somasif ME-100 (manufactured by Coop Chemical Co., Ltd.) was added to 193.6 g of ion-exchanged water, and dispersed using an homogenizer until the average particle size (laser scattering method) became 3 μm. The aspect ratio of the obtained dispersed particles was 100 or more.

<Evaluation of planographic printing plate>
(On-press developability)
The resulting lithographic printing plate precursor was exposed with a Luxel PLASETTER T-6000III manufactured by Fuji Film Co., Ltd. equipped with an infrared semiconductor laser under the conditions of an outer drum rotation speed of 1000 rpm, a laser output of 70%, and a resolution of 2400 dpi. The exposure image includes a solid image and a 50% dot chart of a 20 μm dot FM screen.
The obtained exposed original plate was attached to a plate cylinder of a printing machine LITHRONE 26 manufactured by Komori Corporation without developing. Equality-2 (manufactured by FUJIFILM Corporation) / tap water = 2/98 (volume ratio) dampening water and Values-G (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.) After dampening water and ink were supplied by the standard automatic printing start method of LITHRONE 26 and developed on the machine, 100 sheets were printed on Tokuhishi Art (76.5 kg) paper at a printing speed of 10,000 sheets per hour.
Measures the number of print sheets required until the on-press development on the printing machine in the unexposed area of the 50% halftone chart is completed and the ink is not transferred to the halftone dot non-image area as the on-press developability. did. In order from the one having the best on-press developability, it was represented by ◎ (20 sheets or less of damaged paper), ○ (21 to 30 sheets of damaged paper), and × (31 or more sheets of damaged paper). The results are shown in Table 3.

(Number of neglected payments)
After the on-press development is completed, after a good printed matter can be obtained, the printing is temporarily stopped, and the printing is resumed after being left on the printing press for 1 hour in a room at 25 ° C. and a humidity of 50%. Then, the number of damaged sheets of printing paper required until a good print with no stain was obtained was evaluated. In order from the one with the best neglectability, it is represented by ◎ (75 sheets or less of damaged paper), ○ (76 to 300 sheets of damaged paper), and × (301 or more sheets of damaged paper). The results are shown in Table 3.

(Print life)
After on-press development using the same printing machine and method as described above, printing was further continued. The printing durability was evaluated based on the number of printed sheets when it was visually recognized that the density of the solid image started to decrease. The number of printed sheets is less than 10,000, the number of 10,000 or more and less than 20,000 is △, the number of 20,000 or more and less than 30,000 is ◯, and the number of printed sheets is 30,000 or more. The results are shown in Table 3. In addition, as an evaluation result in Table 3, it is necessary that “Δ” or “×” is not included.

(Scratch resistance)
The scratch resistance of the lithographic printing plate support was evaluated by a scratch test on the surface of the obtained lithographic printing plate support.
The scratch test was performed using a continuous load-type scratch strength tester (SB-53, manufactured by Shinto Kagaku Co., Ltd.) under the conditions of a sapphire needle of 0.4 mmφ and a needle moving speed of 10 cm / second under a load of 100 g.
As a result, the case where scratches by the needle did not reach the surface of the aluminum alloy plate (base) was evaluated as “◯” as being excellent in scratch resistance, and the case where it was reached was evaluated as “×”. The support for a lithographic printing plate having a weight value of 100 g and excellent scratch resistance can suppress the transfer of scratches to the image recording layer during winding and lamination when it is used as a lithographic printing plate precursor. Dirt can be suppressed.

  As shown in Table 3, a lithographic printing plate using a lithographic printing support provided with an aluminum anodic oxide film on which micropores having an average diameter and depth in a predetermined range are formed (Examples 1 to 31) It was confirmed that the film exhibited excellent printing durability, neglectability, on-press developability and scratch resistance. In addition, the shape of the large diameter hole part which comprises the micropore obtained in Examples 1-31 was a substantially hemispherical shape, and the shape of the small diameter hole part was a substantially straight tube shape.

  On the other hand, in Comparative Examples 1-18 that do not satisfy the relationship between the average diameter and the depth of the present invention, only inferior results were obtained as compared with Examples 1-31.

DESCRIPTION OF SYMBOLS 1,12 Aluminum plate 2, 4 Roller-like brush 3 Polishing slurry liquid 5, 6, 7, 8 Support roller ta Anode reaction time tc Cathode reaction time tp Time until current reaches peak from 0 Ia At peak time on anode cycle side Current Ic Current at the peak on the cathode cycle side 10 Lithographic printing plate support 14, 14a, 14b, 14c, 14d, 14e, 14f Aluminum anodized film 16, 16a, 16b, 16c, 16d, 16e, 16f Micropore 18 Large-diameter hole 20 Small-diameter hole 50 Main electrolytic cell 51 AC power supply 52 Radial drum roller 53a, 53b Main electrode 54 Electrolyte supply port 55 Electrolytic solution 56 Auxiliary anode 60 Auxiliary anode tank W Aluminum plate 610 Anodizing treatment device 612 Power supply Tank 614 Electrolytic treatment tank 616 Aluminum plate 6 8,626 electrolyte 620 feeding electrodes 622,628 roller 624 nip roller 630 electrolytic electrode 632 tank wall 634 a DC power source

Claims (11)

A support for a lithographic printing plate comprising an aluminum plate and an anodized film of aluminum thereon, and having micropores extending in a depth direction from the surface opposite to the aluminum plate in the anodized film. ,
The micropore communicates with a large-diameter hole extending from the surface of the anodized film to a position having a depth of 5 to 60 nm (depth A) and a bottom of the large-diameter hole, and having a depth of 900 to 2000 nm from the communication position. It consists of a small diameter hole that extends to the position,
The average diameter of the large-diameter hole portion on the surface of the anodized film is more than 60 nm and not more than 100 nm, and the average diameter and the depth A satisfy the relationship of (depth A / average diameter) = 0.05 to 0.95,
A support for a lithographic printing plate, wherein the average diameter of the small-diameter hole at the communicating position is greater than 0 and less than 15 nm.   The lithographic printing plate support according to claim 1, wherein the average diameter of the large-diameter hole is more than 60 nm and not more than 85 nm.   The lithographic printing plate support according to claim 1 or 2, wherein the depth A is 7 to 50 nm.   The support for a lithographic printing plate according to any one of claims 1 to 3, wherein the value of (depth A / average diameter) is 0.1 or more and less than 0.8. A first anodizing process for anodizing the aluminum plate;
A pore-wide treatment step in which the aluminum plate having the anodized film obtained in the first anodizing treatment step is brought into contact with an aqueous acid solution or an aqueous alkaline solution to increase the diameter of the micropores in the anodized film;
A lithographic printing plate support for producing the lithographic printing plate support according to any one of claims 1 to 4, further comprising a second anodizing treatment step for anodizing the aluminum plate obtained in the pore-wide treatment step. Body manufacturing method.   The ratio (film thickness 1 / thickness) of the thickness of the anodized film (film thickness 1) obtained in the first anodizing process and the thickness of the anodized film (film thickness 2) obtained in the second anodizing process. The manufacturing method of the support body for lithographic printing plates of Claim 5 whose film thickness 2) is 0.002-0.15.   The method for producing a lithographic printing plate support according to claim 5 or 6, wherein the thickness of the anodized film obtained in the first anodizing treatment step is 15 to 80 nm.   The method for producing a lithographic printing plate support according to any one of claims 5 to 7, wherein the thickness of the anodized film obtained in the second anodizing treatment step is 900 to 2000 nm.   The manufacturing method of the support body for lithographic printing plates in any one of Claims 5-8 which performs the said 1st anodizing process process in the electrolyte solution containing phosphoric acid.   A planographic printing plate precursor comprising an image recording layer on the planographic printing plate support according to any one of claims 1 to 4.   The lithographic printing plate precursor according to claim 10, wherein the image recording layer is an image recording layer which forms an image by exposure and the non-exposed portion can be removed by printing ink and / or fountain solution.