JP2018140618A - Lithographic printing original plate, method for manufacturing lithographic printing plate, and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lithographic printing original plate excellent in deinking ability after leaving to stand, UV ink plate wearability, and scratch resistance when made as a lithographic printing plate, to provide a method for manufacturing a lithographic printing plate, and to provide a printing method.SOLUTION: A lithographic printing original plate includes an aluminum substrate, an undercoat layer, and an image recording layer in this order. The lithographic printing original plate is such that: the undercoat layer includes a compound including a betaine structure; the aluminum substrate includes an aluminum plate and an aluminum anodic oxide film arranged on the aluminum plate; and the anodic oxide film has prescribed micro pores.SELECTED DRAWING: None

Description

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

In recent years, lithographic printing plates have been obtained by CTP (computer to plate) technology, and many studies have been made accordingly.
For example, Patent Document 1 discloses a lithographic printing plate precursor using a lithographic printing plate support including an anodized film having a predetermined micropore.

JP 2012-158022 A

On the other hand, there is a demand for further improvement in neglectability when a planographic printing plate is used. In the following, the number of damaged paper sheets generated when printing is paused and restarted is evaluated as neglectability, and the fact that the number of damaged paper sheets is small is said to be excellent in neglectability.
When the present inventors examined the characteristics of the lithographic printing plate precursor specifically described in Patent Document 1, the neglectability does not satisfy the level required recently, and further improvements have been made. I found it necessary.
In addition, the lithographic printing plate precursor is also required to have excellent scratch resistance when converted into a lithographic printing plate.
Furthermore, the lithographic printing plate precursor is also required to have excellent UV (ultraviolet) ink printing durability when formed into a lithographic printing plate.
The UV ink printing durability is printing durability when UV ink is used. Unlike normal ink, UV ink has high polarity, high viscosity, and high tack. For this reason, the UV ink tends to erode the image area, and the printing durability when UV ink is used tends to be lower than the printing durability when ordinary ink is used.

In view of the above circumstances, an object of the present invention is to provide a lithographic printing plate precursor having excellent neglectability, UV ink printing durability, and scratch resistance when used as a lithographic printing plate.
Another object of the present invention is to provide a method for producing a lithographic printing plate and a printing method.

As a result of intensive studies to achieve the above object, the present inventors have found that the above problem can be solved by using an undercoat layer containing a predetermined component.
That is, it has been found that the above object can be achieved by the following configuration.

(1) A lithographic printing plate precursor comprising an aluminum support, an undercoat layer, and an image recording layer in this order,
The undercoat layer comprises a compound having a betaine structure or polyvinylphosphonic acid,
An aluminum support comprising an aluminum plate and an anodized film of aluminum disposed on the aluminum plate;
The anodized film is located on the undercoat layer side of the aluminum plate,
The anodized film has micropores extending in the depth direction from the surface opposite to the aluminum plate,
A micropore has a large-diameter hole extending from the surface of the anodized film to a depth of 20 to 200 nm, a small-diameter hole extending from the communication position to a depth of 500 to 2000 nm, and communicating with the bottom of the large-diameter hole. Consisting of
The average diameter of the large-diameter hole portion on the anodized film surface is 15 to 60 nm,
The ratio of the depth of the large-diameter hole to the average diameter of the large-diameter hole is 0.3 to 13.3,
A lithographic printing plate precursor having an average diameter of 13 nm or less at the communication position of the small-diameter hole.
(2) The lithographic printing plate precursor as described in (1), wherein the betaine structure is a structure represented by the formula (i) described later.
(3) The polymer containing a betaine structure is a polymer containing a repeating unit having a betaine structure, a repeating unit having a structure that interacts with the surface of an aluminum support, and a repeating unit having a radical polymerizable reactive group. A lithographic printing plate precursor as described in (1) or (2).
(4) The content of the repeating unit having a betaine structure is 50 to 95% by mass with respect to all the repeating units,
The content of the repeating unit having a structure that interacts with the surface of the aluminum support is 1 to 40% by mass with respect to all the repeating units,
The lithographic printing plate precursor as described in (3), wherein the content of the repeating unit having a radically polymerizable reactive group is 1 to 30% by mass based on all repeating units.
(5) The lithographic printing plate precursor as described in any one of (1) to (4), wherein the average diameter of the large-diameter hole portion on the surface of the anodized film is 18 to 50 nm.
(6) The lithographic printing plate precursor as described in any one of (1) to (5), wherein the depth of the large-diameter hole is 40 to 180 nm.
(7) The lithographic printing plate precursor as described in any one of (1) to (6), wherein the image recording layer contains an acid color former.
(8) The lithographic printing plate precursor as described in (7), wherein the acid color former is at least one compound selected from the group consisting of spiropyran compounds, spirooxazine compounds, spirolactone compounds, and spirolactam compounds.
(9) The ratio of the depth of the large-diameter hole of the micropore to the content of the repeating unit having a betaine structure is 0.8 to 2.4, or any one of (1) to (8) Lithographic original plate.
(10) An exposure step of exposing the lithographic printing plate precursor according to any one of (1) to (9) imagewise to form an exposed portion and an unexposed portion;
And a removing step of removing an unexposed portion of the lithographic printing plate precursor that has been imagewise exposed.
(11) An exposure step of imagewise exposing the lithographic printing plate precursor according to any one of (1) to (10) to form an exposed portion and an unexposed portion;
A printing process comprising: supplying at least one of printing ink and fountain solution, removing an unexposed portion of the lithographic printing plate precursor imagewise exposed on a printing machine, and performing printing.

According to the present invention, it is possible to provide a lithographic printing plate precursor having excellent neglectability, UV ink printing durability and scratch resistance when used as a lithographic printing plate.
Moreover, according to this invention, the manufacturing method of a lithographic printing plate and the printing method can be provided.

1 is a schematic cross-sectional view of an embodiment of a lithographic printing plate precursor according to the invention. It is a typical sectional view of one embodiment of an aluminum support.

Hereinafter, the planographic printing plate precursor, the planographic printing plate production method, and the printing method of the present invention will be described.
In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In addition, in the present specification, regarding the notation of a group in the compound represented by the formula, when substitution or non-substitution is not described, if the group can further have a substituent, there are other special provisions. Unless otherwise specified, the group includes not only an unsubstituted group but also a group having a substituent. For example, in the formula, if there is a description that “R represents an alkyl group, an aryl group or a heterocyclic group”, “R is an unsubstituted alkyl group, a substituted alkyl group, an unsubstituted aryl group, a substituted aryl group, an unsubstituted group” Represents a heterocyclic group or a substituted heterocyclic group.

FIG. 1 is a schematic cross-sectional view of one embodiment of a lithographic printing plate precursor according to the present invention.
The planographic printing plate precursor 10 shown in FIG. 1 includes an aluminum support 12, an undercoat layer 14, and an image recording layer 16.
FIG. 2 is a schematic cross-sectional view of an embodiment of the aluminum support 12. The aluminum support 12 has a laminated structure in which an aluminum plate 18 and an aluminum anodized film 20 (hereinafter simply referred to as “anodized film 20”) are laminated in this order. The anodic oxide film 20 in the aluminum support 12 is located closer to the undercoat layer 14 than the aluminum plate 18. That is, the lithographic printing plate precursor 10 has the aluminum plate 18, the anodized film 20, the undercoat layer 14, and the image recording layer 16 in this order.
The anodic oxide film 20 has a micropore 22 extending from the surface thereof toward the aluminum plate 18, and the micropore 22 includes a large-diameter hole portion 24 and a small-diameter hole portion 26. Here, the term micropore is a commonly used term representing the pore in the anodized film and does not define the size of the pore.
In the following, first, the undercoat layer 14 will be described, and then the aluminum support 12 and the image recording layer 16 will be described in detail.

<Undercoat layer>
The undercoat layer 14 includes a compound having a betaine structure.
First, the betaine structure refers to a structure having at least one cation and at least one anion. Normally, the number of cations and the number of anions are equal and neutral as a whole, but in the present invention, when the number of cations and the number of anions are not equal, the amount necessary to cancel the charge It is also assumed to have a betaine structure.
The betaine structure is preferably any one of structures represented by the following formulas (1), (2), and (3).

In the formula, A ⁻ represents a structure having an anion, B ⁺ represents a structure having a cation, and L ⁰ represents a linking group. * Represents a linking site (linking position).
A ⁻ preferably represents a structure having anions such as carboxylate, sulfonate, phosphonate, and phosphinate, and B ⁺ preferably represents a structure having cations such as ammonium, phosphonium, iodonium, and sulfonium. .

L ⁰ represents a linking group. In Formula (1) and Formula (3), L ⁰ includes a divalent linking group, and includes —CO—, —O—, —NH—, a divalent aliphatic group, and a divalent aromatic group. Or a combination thereof. In the formula (2), L ⁰ includes a trivalent linking group.
The linking group is preferably a linking group having 30 or less carbon atoms, including the carbon number of the substituent that may be described later.
Specific examples of the linking group include an alkylene group (preferably having 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms), and an arylene group such as a phenylene group and a xylylene group (preferably having 5 to 15 carbon atoms, More preferably, C6-C10 is mentioned.

In addition, these coupling groups may further have a substituent.
Examples of the substituent include a halogen atom, hydroxyl group, carboxyl group, amino group, cyano group, aryl group, alkoxy group, aryloxy group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group, monoalkylamino group, Examples include a dialkylamino group, a monoarylamino group, and a diarylamino group.

  As a betaine structure, at least one of neglectability, on-press developability, UV ink printing durability, and scratch resistance is more excellent (hereinafter, also simply referred to as “the effect of the present invention is more excellent”). The structure represented by Formula (i), Formula (ii), or Formula (iii) is preferable, and the structure represented by Formula (i) is more preferable. * Represents a linking site.

In Formula (i), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and R ¹ and R ² are linked to each other. A ring structure may be formed.
The ring structure may have a hetero atom such as an oxygen atom. As the ring structure, a 5- to 10-membered ring is preferable, and a 5- or 6-membered ring is more preferable.
R ¹ and the number of carbon atoms in ^{R 2} is preferably 1 to 30, 1 to 20 is more preferable.
As R ¹ and R ² , a hydrogen atom, a methyl group, or an ethyl group is preferable in that the effect of the present invention is more excellent.

L ¹ represents a divalent linking group, —CO—, —O—, —NH—, a divalent aliphatic group (for example, an alkylene group), a divalent aromatic group (for example, a phenylene group), Or a combination thereof is preferred.
L ¹ is preferably a linear alkylene group having 3 to 5 carbon atoms.

In formula (i), A ⁻ represents a structure having an anion, and carboxylate, sulfonate, phosphonate or phosphinate is preferable.
Specifically, the following structures are mentioned.

In the formula (i), a combination in which L ¹ is a linear alkylene group having 4 or 5 carbon atoms and A ⁻ is a sulfonate, L ¹ is a linear alkylene group having 4 carbon atoms, and a ^- is more preferred combination is a sulfonate.

In the formula (ii), L ² represents a divalent linking group, —CO—, —O—, —NH—, a divalent aliphatic group (for example, an alkylene group), a divalent aromatic group ( For example, a phenylene group) or a combination thereof is preferable.
B ⁺ represents a structure having a cation, and a structure having ammonium, phosphonium, iodonium, or sulfonium is preferable. Among these, a structure having ammonium or phosphonium is preferable, and a structure having ammonium is more preferable.
Examples of the structure having a cation include trimethylammonio group, triethylammonio group, tributylammonio group, benzyldimethylammonio group, diethylhexylammonio group, (2-hydroxyethyl) dimethylammonio group, pyridinio group, Examples thereof include N-methylimidazolio group, N-acridinio group, trimethylphosphonio group, triethylphosphonio group, and triphenylphosphonio group.

In the formula (iii), L ³ represents a divalent linking group, and represents —CO—, —O—, —NH—, a divalent aliphatic group (for example, an alkylene group), a divalent aromatic group (for example, , A phenylene group) or a combination thereof.
A ⁻ represents a structure having an anion, and is preferably carboxylate, sulfonate, phosphonate, or phosphinate, and the details and preferred examples thereof are the same as A ⁻ in formula (i).
R ^{3 to} R ⁷ each independently represent a hydrogen atom or a substituent (preferably having 1 to 30 carbon atoms), and at least one of R ^{3 to} R ⁷ represents a linking site.
At least one of R ^{3 to} R ⁷ which is a linking site may be linked to another site in the compound via a substituent as at least one of R ^{3 to} R ⁷ , or in the compound by a single bond It may be directly connected to other parts.

Examples of the substituent represented by R ^{3 to} R ⁷ include a halogen atom, an alkyl group (including a cycloalkyl group and a bicycloalkyl group), an alkenyl group (including a cycloalkenyl group and a bicycloalkenyl group), an alkynyl group, and an aryl group. , Heterocyclic group, cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy, amino Group (including anilino group), acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, mercapto group, alkylthio group, ant Ruthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl and heterocyclic azo group, imido group , Phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, and silyl group.

  The above compound is preferably a polymer containing a repeating unit having a betaine structure (hereinafter, also simply referred to as “specific polymer”) in that the effect of the present invention is more excellent. The repeating unit having a betaine structure is preferably a repeating unit represented by the formula (A1).

In formula, R < ¹⁰¹ > -R < ¹⁰³ > represents a hydrogen atom, an alkyl group, or a halogen atom each independently. L represents a single bond or a divalent linking group.
Examples of the divalent linking group include —CO—, —O—, —NH—, a divalent aliphatic group, a divalent aromatic group, or a combination thereof.

Specific examples of L composed of the above combinations are given below. In the following examples, the left side is bonded to the main chain, and the right side is bonded to X.
L1: -CO-O-divalent aliphatic group-
L2: —CO—O—divalent aromatic group—
L3: -CO-NH-divalent aliphatic group-
L4: —CO—NH—divalent aromatic group—
L5: -CO-divalent aliphatic group-
L6: —CO—divalent aromatic group—
L7: -CO-divalent aliphatic group-CO-O-divalent aliphatic group-
L8: -CO-divalent aliphatic group-O-CO-divalent aliphatic group-
L9: -CO-divalent aromatic group-CO-O-divalent aliphatic group-
L10: -CO-divalent aromatic group-O-CO-divalent aliphatic group-
L11: -CO-divalent aliphatic group-CO-O-divalent aromatic group-
L12: -CO-divalent aliphatic group-O-CO-divalent aromatic group-
L13: -CO-divalent aromatic group-CO-O-divalent aromatic group-
L14: -CO-divalent aromatic group-O-CO-divalent aromatic group-
L15: -CO-O-divalent aromatic group-O-CO-NH-divalent aliphatic group-
L16: -CO-O-divalent aliphatic group-O-CO-NH-divalent aliphatic group-

Examples of the divalent aliphatic group include an alkylene group, an alkenylene group, and an alkynylene group.
Examples of the divalent aromatic group include an aryl group, and a phenylene group or a naphthylene group is preferable.

X represents a betaine structure. X is preferably a structure represented by the above formula (i), formula (ii), or formula (iii).
Particularly, in the formula (A1), L is L1 or L3, X is a structure represented by formula (i), A in formula (i) ^- the combination is a sulfonate group.

  The content of the repeating unit having a betaine structure in the specific polymer is not particularly limited, and is often 20 to 95% by mass. From the viewpoint that the effect of the present invention is more excellent, all the repeating units constituting the specific polymer are included. On the other hand, 50-95 mass% is preferable, 60-90 mass% is more preferable, and 65-85 mass% is further more preferable.

The specific polymer may contain a repeating unit other than the repeating unit having the betaine structure.
The specific polymer may include a repeating unit having a structure that interacts with the surface of the aluminum support (hereinafter, also simply referred to as “interaction structure”).
Examples of the interaction structure include a carboxylic acid structure, a carboxylate structure, a sulfonic acid structure, a sulfonate structure, a phosphonic acid structure, a phosphonate structure, a phosphate ester structure, a phosphate ester salt structure, and a β-diketone structure. And a phenolic hydroxyl group, and examples thereof include structures represented by the following formulae. Among these, a carboxylic acid structure, a carboxylate structure, a sulfonic acid structure, a sulfonate structure, a phosphonic acid structure, a phosphonate structure, a phosphate ester structure, or a phosphate ester salt structure is preferable.

In the above formula, R ^{11 to} R ¹³ each independently represent a hydrogen atom, an alkyl group, an aryl group, an alkynyl group, or an alkenyl group, and M, M ₁ and M ₂ each independently represent a hydrogen atom, a metal It represents an atom (for example, an alkali metal atom such as Na or Li) or an ammonium group. B represents a boron atom.

  The repeating unit having an interaction structure is preferably a repeating unit represented by the formula (A2).

In the formula, R ^{201 to} R ²⁰³ each independently represent a hydrogen atom, an alkyl group (preferably having a carbon number of 1 to 6), or a halogen atom.
L represents a single bond or a divalent linking group. Examples of the divalent linking group include —CO—, —O—, —NH—, a divalent aliphatic group, a divalent aromatic group, or a combination thereof.
Specific examples of L composed of a combination include the same as those in the above formula (A1) and the following L17 and L18.
L17: —CO—NH—
L18: -CO-O-
Among L1 to L18, L1 to L4, L17, or L18 is preferable.
Q represents an interaction structure, and a preferred embodiment is the same as described above.

  The content of the repeating unit having an interaction structure in the specific polymer is not particularly limited, but is 1 to 40% by mass with respect to all the repeating units constituting the specific polymer in that the effect of the present invention is more excellent. Preferably, 3-30 mass% is more preferable, and 5-20 mass% is further more preferable.

The specific polymer may contain a repeating unit having a radical polymerizable reactive group.
Radical polymerizable reactive groups include addition-polymerizable unsaturated bond groups (eg (meth) acryloyl group, (meth) acrylamide group, (meth) acrylonitrile group, allyl group, vinyl group, vinyloxy group, and alkynyl). Group) and functional groups capable of chain transfer (such as mercapto groups).
The specific polymer containing a repeating unit having a radically polymerizable reactive group can be obtained by introducing a radically polymerizable reactive group by the method described in JP-A-2001-31068. By using a specific polymer containing a repeating unit having a radically polymerizable reactive group, excellent developability is developed in the unexposed area, and the permeability of the developer is suppressed by polymerization in the exposed area. Adhesiveness and adhesion with the image recording layer are further improved.

  The content of the repeating unit having a radical polymerizable reactive group in the specific polymer is not particularly limited, but is 1 to 30 with respect to all the repeating units constituting the specific polymer in that the effect of the present invention is more excellent. % By mass is preferable, 3 to 20% by mass is more preferable, and 5 to 15% by mass is further preferable.

The content of the compound having the betaine structure in the undercoat layer 14 is not particularly limited, but is preferably 80% by mass or more and more preferably 90% by mass or more with respect to the total mass of the undercoat layer. As an upper limit, 100 mass% is mentioned.
The undercoat layer 14 may contain a compound other than the compound having a betaine structure.

<Aluminum support>
As described above, the aluminum support 12 includes the aluminum plate 18 and the aluminum anodic oxide film 20 disposed on the aluminum plate 18.

(Aluminum plate)
The aluminum plate 18 (aluminum support) is a metal whose main component is aluminum that is dimensionally stable, and is made of aluminum or an aluminum alloy. Examples of the aluminum plate 18 include 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 on which aluminum (alloy) is laminated or deposited. Further, 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.

The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium, and the content of foreign elements in the alloy is 10% by mass or less. . As the aluminum plate 18, a pure aluminum plate is suitable, but since completely pure aluminum is difficult to manufacture in terms of smelting technology, it may contain a slightly different element.
The composition of the aluminum plate 18 is not limited, and a publicly known material (for example, JIS A 1050, JIS A 1100, JIS A 3103, and JIS A 3005) can be used as appropriate.

  The width of the aluminum plate 18 is preferably about 400 to 2000 mm and the thickness is about 0.1 to 0.6 mm. This width or thickness can be appropriately changed depending on the size of the printing press, the size of the printing plate, and the user's desire.

(Anodized film)
The anodized film 20 is an anodized aluminum film that is generally produced on the surface of the aluminum plate 18 by an anodizing process and that has an extremely fine micropore 22 that is substantially perpendicular to the film surface and is uniformly distributed. Point to. The micropore 22 extends along the thickness direction (the aluminum plate 18 side) from the surface of the anodized film opposite to the aluminum plate 18.

The micropores 22 in the anodized film 20 communicate with the large-diameter hole 24 extending from the surface of the anodized film to a depth of 20 to 200 nm (depth A: see FIG. 2) and the bottom of the large-diameter hole 24. The small-diameter hole 26 extends from the communication position to a position having a depth of 500 to 2000 nm.
Below, the large diameter hole part 24 and the small diameter hole part 26 are explained in full detail.

(Large hole)
The average diameter (average opening diameter) of the large-diameter hole 24 on the surface of the anodized film is 15 to 60 nm. Especially, 18-50 nm is preferable and 25-40 nm is more preferable at the point which the effect of this invention is more excellent.
When the average diameter is less than 15 nm, the UV ink printing durability is poor. Moreover, when an average diameter exceeds 60 nm, neglectability is inferior.
The average diameter of the large-diameter hole 24 was determined by observing N = 4 on the surface of the anodic oxide film 20 with a field emission scanning electron microscope (FE-SEM) with a magnification of 150,000 times. This is a value obtained by measuring and averaging the diameters (diameters) of micropores (large-diameter holes) existing in a range of × 600 nm ² .
In addition, when the shape of the large diameter hole portion 24 is not circular, an equivalent circle 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 24 is located at a depth of 20 to 200 nm (hereinafter also referred to as depth A) from the surface of the anodized film. That is, the large diameter hole 24 is a hole extending 20 to 200 nm in the depth direction (thickness direction) from the surface of the anodized film. Especially, 40-180 nm is preferable and, as for the depth A, the point which the effect of this invention is more excellent, 70-140 nm is more preferable.
When the depth A is less than 20 nm, the UV ink printing durability is poor. When the depth A exceeds 200 nm, the neglectability is 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 20, measured the depth of 25 or more large diameter holes, and averaged it.

  Ratio of depth of large-diameter hole portion to content of repeating unit including betaine structure contained in polymer in undercoat layer (depth of large-diameter hole portion (nm) / included in polymer in undercoat layer) The content of the repeating unit containing a betaine structure (mol%) is not particularly limited, but is usually 0.2 to 4.0 in many cases, and 0.8 to 2. 4 is preferable, and 0.8 to 2.0 is more preferable.

  The relationship (depth A / average diameter) between the average diameter of the large-diameter hole portion 24 and the depth A where the bottom portion is located satisfies the relationship of 0.3 to 13.3. Especially, 1.5-9.0 are preferable at the point which the effect of this invention is more excellent.

The shape of the large-diameter hole portion 24 is not particularly limited, and examples thereof include a substantially straight tubular shape (substantially cylindrical shape) and a conical shape whose diameter decreases in the depth direction (thickness direction). preferable. Moreover, the shape of the bottom part of the large diameter hole part 24 is not specifically limited, A curved surface shape (convex shape) may be sufficient, and planar shape may be sufficient.
The inner diameter of the large-diameter hole 24 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 part 24 may have a difference of about 1-10 nm normally from the diameter of an opening part.

(Small hole)
As shown in FIG. 2, the small-diameter hole 26 is a hole that communicates with the bottom of the large-diameter hole 24 and extends further in the depth direction (thickness direction) than the communication position. Although one small diameter hole portion 26 normally communicates with one large diameter hole portion 24, two or more small diameter hole portions 26 may communicate with the bottom of one large diameter hole portion 24.
The average diameter at the communication position of the small diameter hole portion 26 is 13 nm or less. Especially, 11 nm or less is preferable and 10 nm or less is more preferable. The lower limit is not particularly limited, but is often 5 nm or more.
When the average diameter exceeds 13 nm, the neglectability is inferior.

The average diameter of the small diameter hole portion 26, the anodized film 20 surface was observed N = 4 sheets at a magnification 150,000 × FE-SEM, the four images obtained are present in a range of 400 × 600 nm ² Micro It is a value obtained by measuring and averaging the diameter (diameter) of the pore (small-diameter hole). In addition, when the depth of the large-diameter hole is deep, the upper part of the anodic oxide film 20 (region with the large-diameter hole) is cut (for example, cut with argon gas) as necessary, and then the anodic oxide film 20 is cut. The surface may be observed with the FE-SEM to determine the average diameter of the small diameter holes.
In addition, when the shape of the small diameter hole part 26 is not circular, an equivalent circle 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 26 is located at a location extending 500 to 2000 nm in the depth direction from the communication position with the large-diameter hole 24 (corresponding to the depth A described above). In other words, the small diameter hole portion 26 is a hole portion extending further in the depth direction (thickness direction) from the communication position with the large diameter hole portion 24, and the depth of the small diameter hole portion 26 is 500 to 2000 nm. Especially, it is preferable that the small-diameter hole portion 26 extends from the communication position to a depth of 600 to 2000 nm, and the small-diameter hole portion 26 extends from the communication position to a depth of 700 to 2000 nm in that the effect of the present invention is more excellent. It is more preferable.
When the depth is less than 500 nm, the scratch resistance 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 (50,000 times) of the cross section of the anodic oxide film 20, measured the depth of 25 or more small diameter holes, and averaged it.

The shape of the small-diameter hole portion 26 is not particularly limited, and includes a substantially straight tubular shape (substantially cylindrical shape) and a conical shape whose diameter decreases in the depth direction, and a substantially straight tubular shape is preferable. Moreover, the shape of the bottom part of the small diameter hole part 26 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 portion 26 is not particularly limited, but is usually the same size as the diameter at the communication position, or may be smaller or larger than the diameter. In addition, the internal diameter of the small diameter hole part 26 may have a difference of about 1-10 nm normally from the diameter of an opening part.

<Image recording layer>
The image recording layer 16 is preferably an image recording layer that can be removed by printing ink and / or fountain solution.
Hereinafter, each component of the image recording layer 16 will be described.

(Infrared absorber)
The image recording layer 16 preferably contains an infrared absorber.
The infrared absorber preferably has a maximum absorption in a wavelength range of 750 to 1400 nm. In particular, since the on-press development type lithographic printing plate precursor may be developed on-press with a printing machine under white light, infrared absorption having a maximum absorption in a wavelength range of 750 to 1400 nm which is not easily affected by white light. By using the agent, a lithographic printing plate precursor excellent in developability can be obtained.
As the infrared absorber, a dye or a pigment is preferable.

Examples of the dye include commercially available dyes and known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970).
Specific examples of the dye include cyanine dyes, squarylium dyes, pyrylium salts, nickel thiolate complexes, and indolenine cyanine dyes. Among these, a cyanine dye or an indolenine cyanine dye is preferable, a cyanine dye is more preferable, and a cyanine dye represented by the following formula (a) is more preferable.

  Formula (a)

In 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.

R ⁹ and R ¹⁰ each independently represent an aromatic hydrocarbon group, an alkyl group, or a hydrogen atom, and R ⁹ and R ¹⁰ may be bonded to each other to form a ring. Of these, a phenyl group is preferred.
X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms which may contain a hetero atom (N, S, O, halogen atom, Se).
X _a ^- is _{Z a} which will be described below ^- has the same definition as, ^{R a} represents a hydrogen atom, an alkyl group, an aryl group, an amino group also represent a halogen atom.

R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. R ¹ and R ² may be bonded to each other to form a ring, and when forming a ring, a 5-membered ring or a 6-membered ring is preferably formed.
Ar ¹ and Ar ² each independently represent an aromatic hydrocarbon group which may have a substituent (for example, an alkyl group). As the aromatic hydrocarbon group, a benzene ring group or a naphthalene ring group is preferable.
Y ¹ and Y ² each independently represent a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms.
R ³ and R ⁴ each independently represent a hydrocarbon group having 20 or less carbon atoms, which may have a substituent (for example, an alkoxy group).
R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms.
Furthermore, Za ^- represents a counter anion. However, Za ⁻ is not necessary when the cyanine dye represented by the formula (a) has an anionic substituent in its structure and neutralization of charge is not necessary. Za ⁻ includes a halide ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, or a sulfonate ion, and a perchlorate ion, a hexafluorophosphate ion, or an aryl sulfonate ion. preferable.

  Only 1 type may be used for the said infrared absorption dye, 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 paragraphs [0072] to [0076] of JP-A-2008-195018 are preferable.

  The content of the infrared absorber is preferably 0.05 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the total solid content constituting the image recording layer.

(Polymerization initiator)
The image recording layer 16 preferably contains a polymerization initiator.
As the polymerization initiator, a compound (so-called radical polymerization initiator) that generates a radical by energy of light, heat, or both and starts polymerization of a compound having a polymerizable unsaturated group is preferable. Examples of the polymerization initiator include a photopolymerization initiator and a thermal polymerization initiator.
Specifically, polymerization initiators described in paragraphs [0115] to [0141] of JP-A-2009-255434 can be used as the polymerization initiator.
The polymerization initiator is preferably an oxime ester compound or an onium salt such as a diazonium salt, an iodonium salt, and a sulfonium salt from the viewpoint of reactivity and stability.

  The content of the polymerization initiator is preferably 0.1 to 50% by mass, and more preferably 0.5 to 30% by mass with respect to the total mass of the image recording layer.

(Polymerizable compound)
The image recording layer 16 preferably contains a polymerizable compound.
As the polymerizable compound, an addition polymerizable compound having at least one ethylenically unsaturated bond is preferable. Among these, compounds having at least one (preferably two) or more terminal ethylenically unsaturated bonds are more preferable. A so-called radical polymerizable compound is more preferable.
As the polymerizable compound, for example, polymerizable compounds exemplified in paragraphs [0142] to [0163] of JP2009-255434A can be used.

A urethane-based addition polymerizable compound produced by using an addition reaction between an isocyanate and a hydroxyl group is also suitable. As a specific example thereof, a vinyl monomer containing a hydroxyl group represented by the following formula (A) is added to a polyisocyanate compound having two or more isocyanate groups per molecule described in JP-B-48-41708. Examples thereof include a vinylurethane compound containing two or more polymerizable vinyl groups in the added molecule.
^{_{CH 2 = C (R 4)}} COOCH 2 CH (R 5) OH (A)
(However, R ⁴ and R ⁵ represent H or CH _3. )

  The content of the polymerizable compound is preferably 3 to 80% by mass and more preferably 10 to 75% by mass with respect to the total mass of the image recording layer.

(Binder polymer)
The image recording layer 16 preferably contains a binder polymer.
Examples of the binder polymer include known binder polymers. Specific examples of the binder polymer include acrylic resins, polyvinyl acetal resins, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, methacrylic resins, polystyrene resins, novolac phenolic resins, polyester resins, and synthetic rubbers. And natural rubber.
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 preferably 5 to 90% by mass and more preferably 5 to 70% by mass with respect to the total mass of the image recording layer.

(Surfactant)
The image recording layer 16 may contain 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 fluorine-based surfactants.
As the surfactant, for example, surfactants disclosed in paragraphs [0175] to [0179] of JP-A-2009-255434 can be used.

  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 mass of the image recording layer.

The image recording layer 16 may further contain other compounds than those described above, if necessary.
Examples of other compounds include colorants, bake-out agents, polymerization inhibitors, higher fatty acid derivatives, plasticizers, inorganic fine particles, and low levels disclosed in paragraphs [0181] to [0190] of JP-A-2009-255434. Examples include molecular hydrophilic compounds.
In addition, as other compounds, hydrophobized precursors disclosed in paragraphs [0191] to [0217] of JP 2012-187907 A (the image recording layer can be converted to hydrophobic when heat is applied). Fine particles), low molecular weight hydrophilic compounds, sensitizers (for example, phosphonium compounds, nitrogen-containing low molecular compounds, ammonium group-containing polymers), and chain transfer agents are also included.

<Protective layer>
The lithographic printing plate precursor according to the present invention includes a protective layer 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. You may go out.
Examples of the material used for the protective layer include materials described in paragraphs [0213] to [0227] of JP2009-255434A (water-soluble polymer compounds, inorganic layered compounds, and the like).

<Acid color former>
In the lithographic printing plate precursor according to the invention, at least one of the one or more layers of the lithographic printing plate precursor preferably contains an acid color former.
Any of the above-described undercoat layer, image recording layer, and protective layer may contain an acid color former. Of these, the image recording layer preferably contains an acid color former.

  The acid color former means a compound having a property of developing color by heating in a state of accepting an electron accepting compound (for example, proton such as acid). The acid color former has a partial skeleton such as lactone, lactam, sultone, spiropyran, ester, or amide, and is a colorless that rapidly opens or cleaves these partial skeletons when contacted with an electron accepting compound. Compounds are preferred.

  Examples of the acid color former include 3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide (referred to as “crystal violet lactone”) and 3,3-bis (4-dimethylaminophenyl) phthalide. 3- (4-dimethylaminophenyl) -3- (4-diethylamino-2-methylphenyl) -6-dimethylaminophthalide, 3- (4-dimethylaminophenyl) -3- (1,2-dimethylindole -3-yl) phthalide, 3- (4-dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide, 3,3-bis (1,2-dimethylindol-3-yl) -5 -Dimethylaminophthalide, 3,3-bis (1,2-dimethylindol-3-yl) -6-dimethylaminophthalide, 3,3-bis (9-ethyl carbonate) Basol-3-yl) -6-dimethylaminophthalide, 3,3-bis (2-phenylindol-3-yl) -6-dimethylaminophthalide, 3- (4-dimethylaminophenyl) -3- ( 1-methylpyrrol-3-yl) -6-dimethylaminophthalide, 3,3-bis [1,1-bis (4-dimethylaminophenyl) ethylene-2-yl] -4,5,6,7- Tetrachlorophthalide, 3,3-bis [1,1-bis (4-pyrrolidinophenyl) ethylene-2-yl] -4,5,6,7-tetrabromophthalide, 3,3-bis [1 -(4-Dimethylaminophenyl) -1- (4-methoxyphenyl) ethylene-2-yl] -4,5,6,7-tetrachlorophthalide, 3,3-bis [1- (4-pyrrolidino) Phenyl) -1- (4-methoxyphene) ) Ethylene-2-yl] -4,5,6,7-tetrachlorophthalide, 3- [1,1-di (1-ethyl-2-methylindol-3-yl) ethylene-2-yl] -3- (4-Diethylaminophenyl) phthalide, 3- [1,1-di (1-ethyl-2-methylindol-3-yl) ethylene-2-yl] -3- (4-N-ethyl-N -Phenylaminophenyl) phthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-n-octyl-2-methylindol-3-yl) -phthalide, 3,3-bis (1-n -Octyl-2-methylindol-3-yl) -phthalide, 3- (2-methyl-4-diethylaminophenyl) -3- (1-n-octyl-2-methylindol-3-yl) -phthalide, etc. Phthalides,

  4,4-bis-dimethylaminobenzhydrin benzyl ether, N-halophenyl-leucooramine, N-2,4,5-trichlorophenylleucooramine, rhodamine-B-anilinolactam, rhodamine- (4-nitroanilino ) Lactam, rhodamine-B- (4-chloroanilino) lactam, 3,7-bis (diethylamino) -10-benzoylphenoxazine, benzoylleucomethylene blue, 4-nitrobenzoylmethylene blue,

  3,6-dimethoxyfluorane, 3-dimethylamino-7-methoxyfluorane, 3-diethylamino-6-methoxyfluorane, 3-diethylamino-7-methoxyfluorane, 3-diethylamino-7-chlorofluorane, 3 -Diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-6,7-dimethylfluorane, 3-N-cyclohexyl-Nn-butylamino-7-methylfluorane, 3-diethylamino-7- Dibenzylaminofluorane, 3-diethylamino-7-octylaminofluorane, 3-diethylamino-7-di-n-hexylaminofluorane, 3-diethylamino-7-anilinofluorane, 3-diethylamino-7- ( 2'-fluorophenylamino) fluorane, 3-diethylamino- -(2'-chlorophenylamino) fluorane, 3-diethylamino-7- (3'-chlorophenylamino) fluorane, 3-diethylamino-7- (2 ', 3'-dichlorophenylamino) fluorane, 3-diethylamino-7- ( 3'-trifluoromethylphenylamino) fluorane, 3-di-n-butylamino-7- (2'-fluorophenylamino) fluorane, 3-di-n-butylamino-7- (2'-chlorophenylamino) Fluorane, 3-N-isopentyl-N-ethylamino-7- (2′-chlorophenylamino) fluorane, 3-Nn-hexyl-N-ethylamino-7- (2′-chlorophenylamino) fluorane, 3- Diethylamino-6-chloro-7-anilinofluorane, 3-di-n-butylamino-6 Chloro-7-anilinofluorane, 3-diethylamino-6-methoxy-7-anilinofluorane, 3-di-n-butylamino-6-ethoxy-7-anilinofluorane, 3-pyrrolidino-6 Methyl-7-anilinofluorane, 3-piperidino-6-methyl-7-anilinofluorane, 3-morpholino-6-methyl-7-anilinofluorane, 3-dimethylamino-6-methyl-7- Anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-di-n-butylamino-6-methyl-7-anilinofluorane, 3-di-n-pentylamino-6 -Methyl-7-anilinofluorane, 3-N-ethyl-N-methylamino-6-methyl-7-anilinofluorane, 3-Nn-propyl-N-methylamino-6-methyl 7-anilinofluorane, 3-Nn-propyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-Nn-butyl-N-methylamino-6-methyl- 7-anilinofluorane, 3-Nn-butyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-isobutyl-N-methylamino-6-methyl-7-anilino Fluorane, 3-N-isobutyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-isopentyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N -N-hexyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-N -N-Pro Ruamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-butylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-hexylamino- 6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-octylamino-6-methyl-7-anilinofluorane, 3-N- (2′-methoxyethyl) -N-methyl Amino-6-methyl-7-anilinofluorane, 3-N- (2′-methoxyethyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-N- (2′-methoxy) Ethyl) -N-isobutylamino-6-methyl-7-anilinofluorane, 3-N- (2′-ethoxyethyl) -N-methylamino-6-methyl-7-anilinofluorane, 3-N -(2 -Ethoxyethyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-N- (3'-methoxypropyl) -N-methylamino-6-methyl-7-anilinofluorane, 3 -N- (3'-methoxypropyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-N- (3'-ethoxypropyl) -N-methylamino-6-methyl-7- Anilinofluorane, 3-N- (3′-ethoxypropyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-N- (2′-tetrahydrofurfuryl) -N-ethylamino -6-methyl-7-anilinofluorane, 3-N- (4'-methylphenyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-ethyl-7- Anilinofull Oran, 3-diethylamino-6-methyl-7- (3′-methylphenylamino) fluorane, 3-diethylamino-6-methyl-7- (2 ′, 6′-dimethylphenylamino) fluorane, 3-di-n -Butylamino-6-methyl-7- (2 ', 6'-dimethylphenylamino) fluorane, 3-di-n-butylamino-7- (2', 6'-dimethylphenylamino) fluorane, 2,2 -Bis [4 '-(3-N-cyclohexyl-N-methylamino-6-methylfluorane) -7-ylaminophenyl] propane, 3- [4'-(4-phenylaminophenyl) aminophenyl] amino Fluorans such as -6-methyl-7-chlorofluorane and 3- [4 '-(dimethylaminophenyl)] amino-5,7-dimethylfluorane;

  3- (2-Methyl-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-n-propoxycarbonylamino-4-di-n) -Propylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-methylamino-4-di-n-propylaminophenyl) -3- (1 -Ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-methyl-4-di-n-hexylaminophenyl) -3- (1-n-octyl-2-methylindole-3- Yl) -4,7-diazaphthalide, 3,3-bis (2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3,3-bis (1-n-octyl-2-methylindole- -Yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4) -Diethylaminophenyl) -3- (1-octyl-2-methylindol-3-yl) -4 or 7-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2- Methylindol-3-yl) -4 or 7-azaphthalide, 3- (2-hexyloxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4 or 7-azaphthalide 3- (2-Ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-phenylindol-3-yl) -4 or 7-azaphthal 3- (2-butoxy-4-diethylaminophenyl) -3- (1-ethyl-2-phenylindol-3-yl) -4 or 7-azaphthalide 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro -Dinaphthopyran, 3-phenyl-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho- (3-methoxybenzo) spiropyran, 3-propyl-spiro-dibenzopyran-3,6-bis (dimethylamino) ) Phthalides such as fluorene-9-spiro-3 ′-(6′-dimethylamino) phthalide, 3,6-bis (diethylamino) fluorene-9-spiro-3 ′-(6′-dimethylamino) phthalide,

  Others 2'-anilino-6 '-(N-ethyl-N-isopentyl) amino-3'-methylspiro [isobenzofuran-1 (3H), 9'-(9H) xanthen-3-one, 2'-anilino -6 '-(N-ethyl-N- (4-methylphenyl)) amino-3'-methylspiro [isobenzofuran-1 (3H), 9'-(9H) xanthen] -3-one, 3'-N , N-dibenzylamino-6′-N, N-diethylaminospiro [isobenzofuran-1 (3H), 9 ′-(9H) xanthen] -3-one, 2 ′-(N-methyl-N-phenyl) Examples include amino-6 ′-(N-ethyl-N- (4-methylphenyl)) aminospiro [isobenzofuran-1 (3H), 9 ′-(9H) xanthen] -3-one.

Among them, the acid color former is preferably at least one compound selected from the group consisting of spiropyran compounds, spirooxazine compounds, spirolactone compounds, and spirolactam compounds.
The hue of the dye after color development is preferably green, blue or black from the viewpoint of visibility.

  It is also possible to use commercially available products as acid color formers, such as ETAC, RED500, RED520, CVL, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, BLUE220, H -3035, BLUE203, ATP, H-1046, H-2114 (Fukui Yamada Chemical Co., Ltd.), ORANGE-DCF, Vermilion-DCF, PINK-DCF, RED-DCF, BLMB, CVL, GREEN-DCF TH-107 (above, manufactured by Hodogaya Chemical Co., Ltd.), ODB, ODB-2, ODB-4, ODB-250, ODB-BlackXV, Blue-63, Blue-502, GN-169, GN-2, Green -118, Red-40, Red-8 (manufactured by Yamamoto Chemicals Co., Ltd.), and, crystal violet lactone (manufactured by Tokyo Chemicals Industry Co., Ltd.), and the like. Among these commercial products, ETAC, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, H-3035, ATP, H-1046, H-2114, GREEN-DCF, Blue-63 , GN-169, or crystal violet lactone is preferable because the formed film has a good visible light absorption rate.

  These acid color formers may be used alone or in combination of two or more components.

<Method for producing planographic printing plate precursor>
The lithographic printing plate precursor described above can be produced by combining known methods.
First, the above-described aluminum support is preferably a manufacturing method in which the following steps are performed in order.
(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 is brought into contact with an acid aqueous solution or an alkali aqueous solution to increase the diameter of the micropores in the anodized film (second anodizing process). Step of Anodizing Plate The details of the method for producing an aluminum support including the above steps can be found in paragraphs [0044] to [0094] of JP 2012-158022.

The method for producing the undercoat layer is not particularly limited, and examples thereof include a method of applying a coating solution for forming an undercoat layer containing a compound having a betaine structure onto the anodized film of the aluminum support.
The undercoat layer forming coating solution preferably contains a solvent. Examples of the solvent include water or an organic solvent.
As a coating method of the coating liquid for forming the undercoat layer, various known methods can be mentioned. 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 ^{0.1~100mg / m 2, 1~50mg / m} 2 is more preferable.

The method for producing the image recording layer is not particularly limited. For example, an image recording layer forming coating solution containing predetermined components (the above-described infrared absorber, polymerization initiator, polymerizable compound, etc.) is applied onto the undercoat layer. A method is mentioned.
The image recording layer forming coating solution preferably contains a solvent. Examples of the solvent include water or an organic solvent.
Examples of the method for applying the image recording layer forming coating solution include the methods exemplified as the method for applying the undercoat layer forming coating solution.
The coating amount (solid content) of the image recording layer varies depending on the use, but generally 0.3 to 3.0 g / m ² is preferable.

The method for producing the protective layer is not particularly limited, and examples thereof include a method of coating a protective layer-forming coating solution containing a predetermined component on the image recording layer.
The protective layer-forming coating solution preferably contains a solvent. Examples of the solvent include water or an organic solvent.
Examples of the method for applying the image recording layer forming coating solution include the methods exemplified as the method for applying the undercoat layer forming coating solution.
The coating amount of the protective layer is a coating amount after drying is preferably ^{0.01~10g / m 2, 0.02~3g / m} 2 is more preferable.

In the above description, the embodiment in which the undercoat layer contains a compound containing a betaine structure has been described, but the undercoat layer may be combined in an embodiment containing polyvinylphosphonic acid.
The method for producing the undercoat layer containing polyvinyl phosphonic acid is not particularly limited. For example, there is a method of treating an aluminum support with an aqueous solution of an alkali metal silicate and then treating with an aqueous solution of an unsaturated acid polymer having an aqueous polyvinyl phosphonic acid solution. Can be mentioned.
By the treatment with the alkali metal silicate aqueous solution, the silicate can be modified on the anodized film of the aluminum support. Next, the polyvinylphosphonic acid can be modified by treatment with an aqueous polyvinylphosphonic acid solution.

Here, the treatment with the alkali metal silicate aqueous solution means that the aluminum support is immersed in the alkali metal silicate aqueous solution for a predetermined time. In the treatment with the alkali metal silicate aqueous solution, the preferred treatment time is 1 second to 2 minutes, more preferably 5 seconds to 40 seconds, and the preferred temperature of the alkali metal silicate aqueous solution is 40 to 90 ° C., more preferred temperature. Is 50 to 80 ° C., and the preferred alkali metal silicate aqueous solution concentration is 1 g / l to 50 g / l, more preferably 5 g / l to 30 g / l.
The treatment with the aqueous solution of polyvinylphosphonic acid refers to immersing the aluminum support in an aqueous solution of an unsaturated acid polymer of polyvinylphosphonic acid aqueous solution for a predetermined time. In the treatment with the aqueous polyvinylphosphonic acid solution, the preferred treatment time is 5 seconds to 2 minutes, more preferably 10 seconds to 1 minute, and the preferred aqueous solution temperature of the polyvinylphosphonic acid aqueous solution is 40 to 80 ° C., more preferably 50 It is -75 degreeC, and the preferable polyvinylphosphonic acid aqueous solution density | concentration is 0.1 g / l-10 g / l, More preferably, it is 0.2-5 g / l. Moreover, it is preferable that pH of the polyvinylphosphonic acid aqueous solution is adjusted to 2.0-4.5, for example by addition of acids, such as a sulfuric acid and phosphoric acid, and is adjusted to 2.5-3.5. More preferably. The pH of the aqueous solution of these polymers is preferably adjusted by adding an inorganic acid.

Examples of the alkali metal silicate used for the treatment of the aluminum support include sodium silicate, potassium silicate, and lithium silicate.
Polyvinylphosphonic acid may be a homopolymer of vinylphosphonic acid or a copolymer obtained by copolymerizing other monomers. Examples of other monomers include unsaturated acids having a carboxyl group such as (meth) acrylic acid, (meth) acrylamide, vinyl acetate, methyl (meth) acrylate, (meth) acrylonitrile, and styrene. Can be mentioned.

  As a specific manufacturing method for forming an undercoat layer containing polyvinylphosphonic acid, for example, it is immersed in an alkali metal silicate aqueous solution, treated, rinsed with warm water at 65 ° C., and then washed with water. This was then treated by immersing it in an aqueous solution of polyvinylphosphonic acid having a vinylphosphonic acid: methacrylic acid molar ratio of 2: 8, a weight average molecular weight of 50,000 to 100,000, and a pH of about 3.2. A method of washing with water is preferred.

<Method for producing planographic printing plate>
Next, a method for producing a lithographic printing plate using a lithographic printing plate precursor will be described.
In general, a lithographic printing plate is produced by exposing the lithographic printing plate precursor imagewise (image exposure) to form an exposed portion and an unexposed portion; And a step of removing the exposed portion.
More specifically, one embodiment of the method for producing a lithographic printing plate comprises an exposure step of exposing the lithographic printing plate precursor imagewise (image exposure) to form an exposed portion and an unexposed portion, and pH 2-12. And a removing step of removing an unexposed portion of the lithographic printing plate precursor with the developer of lithographic printing plate.
Another aspect of the method for producing a lithographic printing plate is an exposure process in which a lithographic printing plate precursor is exposed imagewise (image exposure) to form an exposed area and an unexposed area, and printing ink and dampening are used. An on-press development process for supplying at least one of water and removing an unexposed portion of the lithographic printing plate precursor imagewise exposed on the printing press.
Hereinafter, these aspects will be described in detail.

The method for producing a lithographic printing plate includes a step of imagewise exposing (image exposing) the lithographic printing plate precursor. Image exposure is performed, for example, by laser exposure through a transparent original having a line image or a halftone dot image, or by laser light scanning with digital data.
The wavelength of the light source is preferably 750 to 1400 nm. In the case of a light source that emits light having a wavelength of 750 to 1400 nm, a lithographic printing plate precursor containing an infrared absorbent, which is a sensitizing dye having absorption in this wavelength region, in the image recording layer is preferably used.
Examples of the light source that emits light having a wavelength of 750 to 1400 nm include a solid-state laser and a semiconductor laser that emit infrared light. Regarding the infrared laser, the output is preferably 100 mW or more, the exposure time per pixel is preferably within 20 microseconds, and the irradiation energy amount is preferably 10 to 300 mJ / cm ² . In order to shorten the exposure time, it is preferable to use a multi-beam laser device. The exposure mechanism may be any of an internal drum system, an external drum system, and a flat bed system.
Image exposure can be performed by a conventional method using a plate setter or the like. In the case of the on-press development method described later, the lithographic printing plate precursor may be subjected to image exposure on the printing machine after the lithographic printing plate precursor is mounted on the printing machine.

  An image-exposed lithographic printing plate precursor is a non-exposed portion by removing a non-exposed portion with a developer having a pH of 2 to 12 (developer processing method) or at least one of printing ink and dampening water on a printing press. The development process is carried out by a method for removing the toner (on-machine development method).

(Developer processing method)
In the developer processing method, the image-exposed lithographic printing plate precursor is processed with a developer having a pH of 2 to 14, and the image recording layer in the non-exposed area is removed to produce a lithographic printing plate.
The developer includes a compound (specific compound) having at least one acid group selected from the group consisting of a phosphoric acid group, a phosphonic acid group, and a phosphinic acid group, and one or more carboxyl groups, and has a pH of Developers that are 5-10 are preferred.
Details of each component of the developer will be described below.

The specific compound has at least one acid group selected from the group consisting of a phosphoric acid group, a phosphonic acid group, and a phosphinic acid group that are adsorbable to a hydrophilic support, and further has a hydrophilic carboxyl group. Thus, it is considered that the surface of the lithographic printing plate is made hydrophilic to improve the stain resistance, particularly the scratch resistance.
The specific compound preferably has a phosphoric acid group or a phosphonic acid group.
Phosphoric acid group, phosphonic acid group, phosphinic acid group and carboxyl group in specific compounds are divalent metal ions such as calcium ion and magnesium ion, as well as monovalent metal ions such as potassium ion and sodium ion, or ammonium A salt may be formed with ions or the like.

The total number of phosphoric acid groups, phosphonic acid groups and phosphinic acid groups in the specific compound is preferably 1 to 4, more preferably 1 to 3, still more preferably 1 or 2, and particularly preferably 1 from the viewpoint of scratch resistance. .
The total number of carboxyl groups in the specific compound is preferably 1 to 10, more preferably 2 to 10, more preferably 3 to 6, and particularly preferably 3 or 4 from the viewpoint of scratch resistance.
The total carbon number of the specific compound is preferably from 3 to 50, more preferably from 3 to 20, still more preferably from 4 to 12, and particularly preferably from 5 to 10 from the viewpoint of scratch resistance.
Moreover, as for a specific compound, it is preferable that parts other than a phosphoric acid group, a phosphonic acid group, a phosphinic acid group, and a carboxyl group consist of a carbon atom, a hydrogen atom, and an oxygen atom as needed.

A specific compound may be used individually by 1 type, or may use 2 or more types together.
0.1-10 mass% is preferable with respect to the total mass of a developing solution, as for content of a specific compound, 0.3-8 mass% is more preferable, and 0.5-6 mass% is further more preferable. When the content is in the above range, scratch resistance is excellent, and the resulting lithographic printing plate is excellent in fleshing property.
The molecular weight of the specific compound is preferably 1,000 or less, more preferably 600 or less, and even more preferably 150 to 500. When the viscosity is within the above range, the viscosity of the developer is moderate, and when an automatic processor is used, deposition of developer components on the roller of the automatic developer can be suppressed, and roller contamination can be suppressed.

  Specific examples preferable as the specific compound include the following.

The developer may contain a surfactant such as an anionic surfactant, a nonionic surfactant, a cationic surfactant, and a betaine surfactant.
Among them, the developer preferably contains at least one selected from the group consisting of an anionic surfactant and a nonionic surfactant from the viewpoint of scratch resistance and wear resistance. It is more preferable that an agent and a nonionic surfactant are included.

As the anionic surfactant, a compound represented by the following formula (I) is preferable.
R ¹ -Y ¹ -X ¹ (I)
In Formula (I), R ¹ represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, or an aryl group, which may have a substituent.
As an alkyl group, a C1-C20 alkyl group is preferable, for example.
The cycloalkyl group may be monocyclic or polycyclic. As the monocyclic type, a monocyclic cycloalkyl group having 3 to 8 carbon atoms is preferable. As the polycyclic type, for example, an adamantyl group, a norbornyl group, an isobornyl group, a camphanyl group, a dicyclopentyl group, an α-pinel group, or a tricyclodecanyl group is preferable.
As the alkenyl group, for example, an alkenyl group having 2 to 20 carbon atoms is preferable.
As the aralkyl group, for example, an aralkyl group having 7 to 12 carbon atoms is preferable.
As the aryl group, for example, an aryl group having 6 to 15 carbon atoms is preferable.

  In addition, as the substituent, a monovalent nonmetallic atomic group excluding a hydrogen atom is used, and a halogen atom, a hydroxyl group, an alkoxy group, an aryloxy group, an acyl group, an amide group, an ester group, an acyloxy group, a carboxyl group, Examples thereof include a carboxylic acid anion group and a sulfonic acid anion group.

X ¹ represents a sulfonate group, a monoester sulfate, a carboxylate group, or a phosphate group.
Y ¹ is a single bond, —C _n H _2n —, —C _nm H _{2 (nm)} OC _m H _2m —, —O— (CH ₂ CH ₂ O) _n —, —O— (CH ₂ CH ₂ CH ₂ O) _n —, —CO—NH—, or a divalent linking group composed of a combination of two or more thereof, where n ≧ 1 and n ≧ m ≧ 0.

  The compound represented by the formula (I) is preferably a compound represented by the following formula (IA) or (IB) from the viewpoint of scratch resistance.

In formula (IA) and formula (IB), R ^{A1 to} R ^A10 each independently represents a hydrogen atom or an alkyl group, nA represents an integer of 1 to 3, and X ^A1 and X ^A2 represent Each independently represents a sulfonate group, a sulfate monoester base, a carboxylate group or a phosphate group, and Y ^A1 and Y ^A2 each independently represent a single bond, —C _n H _2n —, —C _{n-m H 2 (n-m) OC} m H 2m -, - O- (CH 2 CH 2 O) n -, - O- (CH 2 CH 2 CH 2 O) n -, - CO-NH-, or they Represents a divalent linking group in which two or more are combined, satisfying n ≧ 1 and n ≧ m ≧ 0, and the number of carbon atoms in R ^{A1 to} R ^A5 or R ^{A6 to} R ^A10 and in Y ^A1 or Y ^A2 The sum is 3 or more.

The total number of carbon atoms of R ^{A1 to} R ^A5 and Y ^1A or R ^{A6 to} R ^A10 and Y ^{A2 in} the compound represented by the above formula (IA) or (IB) is preferably 25 or less. 4-20 are more preferable. The structure of the alkyl group described above may be linear or branched.
X ^A1 and X ^A2 in the compound represented by the formula (IA) or the formula (IB) are preferably a sulfonate group or a carboxylate group. As the salt structures in X ^A1 and X ^A2 , alkali metal salts are particularly preferable because they have particularly good solubility in aqueous solvents. Among these, a sodium salt or a potassium salt is more preferable.
Moreover, as a compound represented by the said formula (IA) or a formula (IB), description of Paragraphs 0019-0037 of Unexamined-Japanese-Patent No. 2007-206348 can be referred.
Further, examples of the anionic surfactant also include compounds described in paragraphs 0023 to 0028 of JP-A-2006-65321.

Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ether, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters. , Propylene glycol monofatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid partial ester, polyoxyethylene glycerin Fatty acid partial esters, polyoxyethylene diglycerins, fatty acid diethanolamides, N, N-bis-2-hydroxyalkyl Amines, polyoxyethylene alkyl amines, triethanolamine fatty acid esters, trialkylamine oxides, polyoxyethylene alkyl phenyl ethers, and polyoxyethylene - polyoxypropylene block copolymers.
Further, acetylene glycol-based and acetylene alcohol-based oxyethylene adducts, fluorine-based surfactants, or silicone-based surfactants can also be used. Two or more of these surfactants can be used in combination.

As the nonionic surfactant, a nonionic aromatic ether surfactant represented by the following formula (N1) is preferable.
_{^{X N -Y N -O- (A 1}} ) nB - (A 2) mB -H (N1)
In the formula, X ^N represents an aromatic group which may have a substituent, Y ^N represents a single bond or an alkylene group having 1 to 10 carbon atoms, and A ¹ and A ² are groups different from each other. , —CH ₂ CH ₂ O— or —CH ₂ CH (CH ₃ ) O—, each of nB and mB independently represents an integer of 0 to 100, provided that nB and mB are not 0 at the same time, When either nB or mB is 0, nB and mB are not 1.
Wherein the aromatic group of X ^N, a phenyl group, a naphthyl group, and include anthranyl group. These aromatic groups may have a substituent. Examples of the substituent include an organic group having 1 to 100 carbon atoms. In the formula, when both A and B are present, they may be random or block copolymers.
Specific examples of the organic group having 1 to 100 carbon atoms include an aliphatic hydrocarbon group which may be saturated or unsaturated and may be linear or branched, and an aromatic hydrocarbon group.
In addition, as the nonionic surfactant, compounds described in paragraphs 0030 to 0040 of JP-A-2006-65321 can also be suitably used.

Surfactant may be used individually by 1 type, or may use 2 or more types together.
The content of the surfactant is preferably 1 to 25% by mass, more preferably 2 to 20% by mass, further preferably 3 to 15% by mass, and particularly preferably 5 to 10% by mass with respect to the total mass of the developer. . When it is within the above range, scratch resistance is excellent, development residue dispersibility is excellent, and the resulting lithographic printing plate is excellent in fleshing property.
Moreover, when using together nonionic surfactant and anionic surfactant, it is preferable that content of nonionic surfactant is larger than content of anionic surfactant. In the above embodiment, the developability is excellent, and the scratch resistance is excellent.
Further, when a nonionic surfactant and an anionic surfactant are used in combination, the content of the nonionic surfactant and the content of the anionic surfactant in the developer are from the viewpoint of developability and scratch resistance. The mass ratio (nonionic surfactant / anionic surfactant) is preferably 1.2 / 1.0 to 5.0 / 1.0, and 1.5 / 1.0 to 4.0 / 1. 0 is more preferable, and 2.0 / 1.0 to 3.0 / 1.0 is more preferable.

The developer may contain a water-soluble polymer from the viewpoint of adjusting the viscosity of the developer and protecting the plate surface of the resulting lithographic printing plate.
Examples of water-soluble polymers include soybean polysaccharide, modified starch, gum arabic, dextrin, fibrin derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and modified products thereof, pullulan, polyvinyl alcohol and derivatives thereof, polyvinylpyrrolidone, Examples include polyacrylamide and acrylamide copolymers, vinyl methyl ether / maleic anhydride copolymers, vinyl acetate / maleic anhydride copolymers, and styrene / maleic anhydride copolymers.

  As the soybean polysaccharide, those conventionally known can be used. For example, as a commercial product, there is a trade name Soya Five (manufactured by Fuji Oil Co., Ltd.), and various grades can be used. Among them, a 10% by mass aqueous solution having a viscosity in the range of 10 to 100 mPa / sec is preferable.

  As the modified starch, a starch represented by the following formula (III) is preferable. As the starch represented by the formula (III), any starch of corn, potato, tapioca, rice and wheat can be used. As a method for modifying these starches, there may be mentioned a method of decomposing in the range of 5 to 30 glucose residues per molecule with an acid or an enzyme, and further adding oxypropylene in an alkali.

  In the formula, the degree of etherification (degree of substitution) is in the range of 0.05 to 1.2 per glucose unit, n represents an integer of 3 to 30, and m represents an integer of 1 to 3.

  As the water-soluble polymer compound, soybean polysaccharide, modified starch, gum arabic, dextrin, carboxymethylcellulose, or polyvinyl alcohol is preferable.

Two or more water-soluble polymer compounds can be used in combination.
When the developer does not contain a water-soluble polymer compound or contains a water-soluble polymer compound, the content of the water-soluble polymer compound exceeds 0% by mass with respect to the total mass of the developer. The content is preferably 1% by mass or less, more preferably more than 0% by mass and 0.1% by mass or less, and further preferably more than 0% by mass and 0.05% by mass or less. Among these, the developer preferably does not contain a water-soluble polymer compound. In the above embodiment, the viscosity of the developer is moderate and it is possible to suppress the accumulation of development debris on the roller member of the automatic processor.

  In addition to the above, the developer may contain a wetting agent, an antiseptic, a chelate compound, an antifoaming agent, an organic acid, an organic solvent, an inorganic acid, and an inorganic salt.

  As the wetting agent, ethylene glycol, propylene glycol, triethylene glycol, butylene glycol, hexylene glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, or diglycerin is preferable. These wetting agents may be used alone or in combination of two or more. The content of the wetting agent is preferably 0.1 to 5% by mass with respect to the total mass of the developer.

Preservatives include phenol or derivatives thereof, formalin, imidazole derivatives, sodium dehydroacetate, 4-isothiazolin-3-one derivatives, benzoisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, benztriazole derivatives Amiding anidine derivatives, quaternary ammonium salts, derivatives such as pyridine, quinoline, guanidine, diazine, triazole derivatives, oxazole, oxazine derivatives, nitrobromoalcohol-based 2-bromo-2-nitropropane-1,3-diol, 1,1-dibromo-1-nitro-2-ethanol or 1,1-dibromo-1-nitro-2-propanol is preferred.
The content of the preservative is an amount that exerts a stable effect on bacteria, molds, and yeasts, and varies depending on the types of bacteria, molds, and yeasts. 0.01 to 4% by mass is preferable. Moreover, it is preferable to use 2 or more types of preservatives together so that it may be effective with respect to various molds and sterilization.

Examples of the chelating compound include ethylenediaminetetraacetic acid, potassium salt thereof, or sodium salt thereof; diethylenetriaminepentaacetic acid, potassium salt thereof, or sodium salt thereof; triethylenetetraminehexaacetic acid, potassium salt thereof, or sodium salt thereof. Hydroxyethylethylenediaminetriacetic acid, its potassium salt, or its sodium salt; nitrilotriacetic acid, or its sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, its potassium salt, or its sodium salt; Methylenephosphonic acid), potassium salts thereof, sodium salts thereof and the like. Instead of the sodium salt or potassium salt of the chelating agent, an organic amine salt is also effective.
These chelating agents are preferably present stably in the developer and do not impair the printability. As for content of a chelating agent, 0.001-1.0 mass% is preferable with respect to the total mass of a developing solution.

Examples of antifoaming agents include general silicone-based self-emulsifying types, emulsifying types, and nonionic HLB (Hydrophilic-Lipophilic Balance) 5 or less compounds. Among these, silicone antifoaming agents are preferable.
The content of the antifoaming agent is preferably 0.001 to 1.0% by mass with respect to the total mass of the developer.

  Examples of organic acids include citric acid, acetic acid, succinic acid, malonic acid, salicylic acid, caprylic acid, tartaric acid, malic acid, lactic acid, levulinic acid, p-toluenesulfonic acid, xylenesulfonic acid, phytic acid, and organic phosphonic acid. It is done. The organic acid can also be used in the form of its alkali metal salt or ammonium salt. The content of the organic acid is preferably 0.01 to 0.5% by mass with respect to the total mass of the developer.

  Examples of the organic solvent include aliphatic hydrocarbons (hexane, heptane, “Isopar E, H, G” (produced by Esso Chemical Co., Ltd.), gasoline, kerosene, etc.), aromatic hydrocarbons (toluene, And xylene), halogenated hydrocarbons (methylene dichloride, ethylene dichloride, trichlene, monochlorobenzene, etc.), and polar solvents.

  Polar solvents include alcohols (methanol, ethanol, propanol, isopropanol, benzyl alcohol, ethylene glycol monomethyl ether, 2-ethoxyethanol, diethylene glycol monoethyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, propylene glycol monoethyl ether , Propylene glycol monomethyl ether, polyethylene glycol monomethyl ether, polypropylene glycol, tetraethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monobenzyl ether, ethylene glycol monophenyl ether, methylphenyl carbinol, n-amyl alcohol, and methyl amyl alcohol ), Ketones (acetone, methyl ethyl ketone, ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), esters (ethyl acetate, propyl acetate, butyl acetate, amyl acetate, benzyl acetate, methyl lactate, butyl lactate, ethylene glycol mono) Butyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol acetate, diethyl phthalate, butyl levulinate, etc., and others (triethyl phosphate, tricresyl phosphate, N-phenylethanolamine, N-phenyldiethanolamine, etc.) ).

  When the organic solvent is insoluble in water, it can be used after being solubilized in water using a surfactant or the like. When the developer contains an organic solvent, the concentration of the solvent in the developer is preferably less than 40% by mass from the viewpoint of safety and flammability.

  Examples of inorganic acids and inorganic salts include phosphoric acid, metaphosphoric acid, primary ammonium phosphate, secondary ammonium phosphate, primary sodium phosphate, secondary sodium phosphate, primary potassium phosphate, secondary potassium phosphate, Examples include sodium tripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate, magnesium nitrate, sodium nitrate, potassium nitrate, ammonium nitrate, sodium sulfate, potassium sulfate, ammonium sulfate, sodium sulfite, ammonium sulfite, sodium hydrogen sulfate, nickel sulfate, and the like. The content of the inorganic salt is preferably 0.01 to 0.5% by mass with respect to the total mass of the developer.

The developer is obtained by dissolving or dispersing the above components in water as necessary. The solid content concentration of the developer is preferably 2 to 25% by mass. Further, as the developer, a concentrated solution can be prepared and diluted with water at the time of use.
The developer is preferably an aqueous developer.
The pH of the developer is preferably 5 to 10, more preferably 6 to 9, and further preferably 7 to 9.

The developer preferably contains an alcohol compound from the viewpoint of dispersibility of the development residue.
Examples of the alcohol compound include methanol, ethanol, propanol, isopropanol, and benzyl alcohol. Of these, benzyl alcohol is preferred.
As content of an alcohol compound, 0.01-5 mass% is preferable with respect to the total mass of a developing solution from the point of the dispersibility of development dregs, 0.1-2 mass% is more preferable, 0.2- 1% by mass is more preferable.

  As a method for the development processing, in the case of manual processing, for example, a method in which a developer is sufficiently contained in a sponge or absorbent cotton, the lithographic printing plate precursor is processed while being rubbed, and is sufficiently dried after the processing is completed. It is done. In the case of immersion treatment, for example, a method in which a lithographic printing plate precursor is immersed in a vat or deep tank containing a developer for about 60 seconds and stirred, and then sufficiently dried while rubbing the lithographic printing plate precursor with absorbent cotton or a sponge is suitable. It is mentioned in.

For the development process, it is preferable to use an apparatus with a simplified structure and a simplified process.
In conventional development processing, the protective layer is removed by the pre-water washing step, then development is performed with an alkaline developer, then the alkali is removed in the post-water washing step, gum treatment is performed in the gumming step, and drying is performed in the drying step. To do.
Note that development and gumming can be simultaneously performed with one liquid. As the gum, a polymer is preferable, and a water-soluble polymer compound and a surfactant are more preferable.
Furthermore, it is preferable to simultaneously perform removal of the protective layer, development, and gumming with one liquid without performing a pre-water washing step. Further, after development and gumming, it is preferable to perform drying after removing excess developer using a squeeze roller.

This treatment may be a method of immersing once in the developer, or a method of immersing twice or more. Among them, a method of immersing once or twice in the developer is preferable.
In the immersion, the exposed lithographic printing plate precursor may be passed through a developing solution tank in which the developing solution is accumulated, or the developing solution may be sprayed from a spray or the like onto the plate surface of the exposed lithographic printing plate precursor.
Even in the case of being immersed twice or more in the developer, the same developer or the developer and the developer (fatigue solution) in which the components of the image recording layer are dissolved or dispersed by the development process are used twice. When soaking is described above, it is called development processing with one liquid (one liquid processing).

In the development processing, it is preferable to use a rubbing member, and it is preferable to install a rubbing member such as a brush in the developing bath for removing the non-image portion of the image recording layer.
The development treatment is preferably performed at a temperature of 0 ° C. to 60 ° C., more preferably 15 ° C. to 40 ° C., for example, by immersing the exposed lithographic printing plate precursor in a developer and rubbing with a brush according to a conventional method, or The treatment liquid charged in the external tank can be pumped up, sprayed from a spray nozzle, and rubbed with a brush. These development processes can be carried out a plurality of times. For example, the developer charged in an external tank can be pumped up, sprayed from a spray nozzle and rubbed with a brush, and then the developer is sprayed again from the spray nozzle and rubbed with a brush. When developing using an automatic developing machine, the developing solution becomes fatigued due to an increase in the amount of processing. Therefore, it is preferable to restore the processing capability using a replenisher or a fresh developing solution.

  A gum coater and an automatic developing machine conventionally known for PS plates (Presensitized Plate) and CTP (Computer to Plate) can also be used for the development processing in the present disclosure. When using an automatic developing machine, for example, a method in which a developer charged in a developer tank or a developer charged in an external tank is pumped up and sprayed from a spray nozzle, in a tank filled with the developer. Either a method of immersing and transporting a printing plate with a guide roll in liquid, or a so-called disposable processing method of supplying and processing a substantially unused developer for each plate as required Applicable. In any system, those having a rubbing mechanism by a brush, a molton or the like are more preferable. For example, commercially available automatic processors (Clean Out Unit C85 / C125, Clean-Out Unit + C85 / 120, FCF 85V, FCF 125V, FCF News (Glunz & Jensen), and Azura CX85, Azura CX125, Azura CX125, 150 AGFA GRAPHICS Co., Ltd., or an apparatus in which a laser exposure unit and an automatic developing unit are integrated together can be used.

(On-machine development method)
In the on-press development method, the image-exposed lithographic printing plate precursor is supplied with printing ink and fountain solution on the printing machine, thereby removing the image recording layer in the non-image area and producing a lithographic printing plate. Is done.
In other words, after image exposure of the lithographic printing plate precursor, it is mounted on the printing machine without any developer treatment, or the lithographic printing plate precursor is mounted on the printing machine and image exposure is performed on the printing machine. Then, when printing is performed by supplying printing ink and fountain solution, in the initial stage of printing, in the non-image portion, image recording of the unexposed portion is performed by the supplied printing ink and / or fountain solution. The layer is removed by dissolution or dispersion, and a hydrophilic surface is exposed at that portion. On the other hand, in the exposed portion, the image recording layer cured by exposure forms an oil-based ink receiving portion having a lipophilic surface. Printing ink may be supplied to the printing plate first, or dampening water, but printing ink is supplied first in order to prevent the dampening water from being contaminated by the removed image recording layer components. It is preferable to do.
In this way, the lithographic printing plate precursor is subjected to on-press development on a printing machine and used as it is for printing a large number of sheets. That is, as one aspect of the printing method of the present invention, the lithographic printing plate precursor is exposed imagewise to form an exposed portion and an unexposed portion, and at least one of printing ink and fountain solution is supplied. In addition, there may be mentioned a printing method having a printing step in which an unexposed portion of a lithographic printing plate precursor imagewise exposed on a printing machine is removed and printing is performed.

  In the method for producing a lithographic printing plate from the lithographic printing plate precursor according to the present invention, regardless of the development method, if necessary, before image exposure, during image exposure, or from image exposure to development processing, The entire surface of the lithographic printing plate precursor may be heated.

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

<< Example A: Examples 1 to 19, 25, Comparative Examples 1 to 7 >>
<Manufacture of aluminum support>
From the (Aa) mechanical surface roughening treatment (brush grain method) described in paragraph 0126 of JP2012-158022A to the aluminum alloy plate of material 1S having a thickness of 0.3 mm, (Ai) A desmut treatment in an acidic aqueous solution was performed.
Next, each processing condition from (Aj) the first stage anodizing treatment described in paragraph 0135 of JP2012-158022A to (Am) the third stage anodizing treatment described in paragraph 0138. Were appropriately adjusted to form anodized films having predetermined shapes in Examples and Comparative Examples shown in Table 1 to be described later to obtain an aluminum support.
In addition, the water washing process was performed between all the process processes, and the liquid draining was performed with the nip roller after the water washing process.

<Formation of undercoat layer (1)>
On each aluminum support obtained above, the undercoat layer-forming coating solution A, the undercoat layer-forming coating solution B, or the undercoat layer-forming coating solution C is applied so that the dry coating amount is 20 mg / m ^2. Thus, an aluminum support having an undercoat layer was produced.
(Undercoat layer forming coating solution A)
-Polymers described below: 0.50 g
・ Water: 500.0g

(Undercoat layer forming coating solution B)
-Polymers described below: 0.50 g
・ Water: 500.0g

(Coating liquid C for undercoat layer formation)
-Polymers described below: 0.50 g
・ Water: 500.0g

  In addition, the numerical value of the lower right of the parenthesis of each structural unit in the polymer in the undercoat layer forming coating liquids A to C represents mass%.

<Formation of undercoat layer (2)>
Each aluminum support obtained above is immersed in a coating solution E for forming an undercoat layer (pH = 1.9) at 40 ° C. containing 4 g / L of polyvinylphosphonic acid for 10 seconds. It was washed with demineralized water containing for 2 seconds and dried. P amount and Ca content of the aluminum support after the treatment, were respectively 25 mg / ^{m 2} and 1.9 mg / ^{m 2.}

<Formation of image recording layer>
The image recording layer forming coating solution A or the image recording layer forming coating solution B is applied onto the undercoat layer by a bar coater and then oven-dried at 100 ° C. for 60 seconds to obtain an image having a dry coating amount of 1.0 g / m ² . A recording layer was formed.
The image recording layer forming coating solution A was obtained by mixing the following photosensitive solution (1) and microgel solution (1).

(Photosensitive solution (1))
-Binder polymer (1) [the following structure] 0.240 g
Infrared absorbing dye (1) [the following structure] 0.030 g
・ Polymerization initiator (1) [the following structure] 0.162 g
-Radical 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] 0.050 g
-Sensitizing agent Phosphonium compound (1) [the following structure] 0.055 g
・ Sensitizer Benzyl-dimethyl-octylammonium ・ PF ₆ salt 0.018g
-Sensitizing agent Ammonium group-containing polymer [the following structure, reduced specific viscosity 44 ml / g] 0.035 g
・ Fluorosurfactant (1) [The following structure] 0.008g
・ 2-butanone 1.091g
・ 1-methoxy-2-propanol 8.609g

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

  Binder polymer (1), infrared absorbing dye (1), polymerization initiator (1), phosphonium compound (1), low molecular weight hydrophilic compound (1), ammonium group-containing polymer, and fluorine-based surfactant The structure of (1) is as shown below.

  In addition, Me represents a methyl group, and the numbers on the lower right of the parentheses of the constituent units of the binder polymer (1) and the ammonium group-containing polymer represent a molar ratio.

  The number in the lower right of the parentheses of each constituent unit of the fluorosurfactant (1) represents the molar ratio, and the value in the lower right of the parentheses of the ethyleneoxy unit or propyleneoxy unit represents the number of repetitions. .

-Synthesis of microgel (1)-
4.46 g of polyfunctional isocyanate (Mitsui Chemicals, Inc .; 75% by mass ethyl acetate solution) having the following structure, trimethylolpropane (6 mol) and xylene diisocyanate (18 mol) were added, and methyl was added thereto. 10 g of adduct (manufactured by Mitsui Chemicals, Inc .; 50% by mass ethyl acetate solution) to which one-end polyoxyethylene (1 mol, the number of repeating oxyethylene units is 90) is added, pentaerythritol triacrylate (Nippon Kayaku) 3.15 g of SR444 manufactured by Co., Ltd. and 0.1 g of Pionein A-41C (manufactured by Takemoto Yushi Co., Ltd.) were dissolved in 17 g of ethyl acetate to obtain an oil phase component. Moreover, 40 g of 4 mass% aqueous solution of polyvinyl alcohol (Kuraray Co., Ltd. PVA-205) was prepared, and the water phase component was obtained.
The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12000 rpm using a homogenizer. The obtained emulsion was added to 25 g of distilled water, and the resulting solution was stirred at room temperature for 30 minutes, and further stirred at 50 ° C. for 3 hours. Distilled water was used to dilute the solid content concentration of the obtained microgel to 15% by mass, and this was designated as microgel (1). When the average particle diameter of the microgel (1) was measured by a light scattering method, the average particle diameter was 0.2 μm.

  As the image recording layer forming coating solution B, 0.029 g of the following acid color former [CL-1] was further added to the photosensitive solution (1), and the microgel solution (1) was mixed with the obtained photosensitive solution. I got it.

CL-1: S-205 (manufactured by Fukui Yamada Chemical Co., Ltd.)

<Formation of protective layer>
On the image recording layer, a protective layer coating solution (1) having the following composition was further applied by a bar coater, followed by oven drying at 120 ° C. for 60 seconds to form a protective layer having a dry coating amount of 0.15 g / m ^2. Then, a lithographic printing plate precursor was prepared.
(Protective layer coating solution (1))
・ Inorganic layered compound dispersion (1) 1.5 g
・ Polyvinyl alcohol (CKS50, Nippon Synthetic Chemical Industry Co., Ltd., sulfonic acid modification, saponification degree 99 mol% or more, polymerization degree 300) 6% by mass aqueous solution 0.55 g
Polyvinyl alcohol (PVA-405 manufactured by Kuraray Co., Ltd., saponification degree 81.5 mol%, polymerization degree 500) 6% by mass aqueous solution 0.03 g
・ Nippon Emulsion Co., Ltd. surfactant (Emalex 710) 1% by weight aqueous solution 0.86g
・ Ion-exchanged water 6.0g

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

<Evaluation of planographic printing plate precursor>
(On-press developability)
The resulting lithographic printing plate precursor was exposed with a Luxel PLASETTER T-6000III equipped with an infrared semiconductor laser under the conditions of an external 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% halftone dot chart of a 20 μm dot FM (Frequency Modulation) screen.
The obtained exposed lithographic printing plate precursor was mounted on 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.
On-press developability is the number of lost paper on the printing paper required until the on-press development on the printing machine of the unexposed area of the 50% halftone chart is completed and the ink is not transferred to the non-halftone dot image area. As measured. In order from the one having the best on-machine developability, A (10 damaged paper or less), B (11 to 15 damaged paper), C (16 to 19 damaged paper), and D (20 or more damaged paper). did. The results are shown in Table 1.

(Number of neglected payments)
After the on-press development was completed, good prints were obtained, and then printing was temporarily stopped, and printing was resumed by leaving it on the press for 4 hours in a room at a temperature of 25 ° C. and a humidity of 50%. In some cases, 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 A (75 sheets or less of damaged paper), B (76 to 200 sheets of damaged paper), C (201 to 300 sheets of damaged paper), and D (301 or more sheets of damaged paper). did. The results are shown in Table 1.

(UV ink printing durability)
The obtained lithographic printing plate precursor was subjected to an external drum rotation speed of 1,000 rpm, a laser output of 70%, and a resolution of 2,400 dpi (dot per inch) using a Luxel PLANETTER T-6000III manufactured by FUJIFILM Corporation equipped with an infrared semiconductor laser. ). The exposure image included a solid image, a 3% halftone dot of TAFFET A20 (FM screen), and a letter cut chart of 7 points tomorrow. Note that 1 inch = 25.4 mm.
The obtained exposed lithographic printing plate precursor was mounted on a plate cylinder of a Mitsubishi Dia IF2 printing machine without developing. Using IF102 (Fuji Film Co., Ltd.) / Tap water = 3/97 (volume ratio) dampening water and GE Carton ink (TOKA Ink Co., Ltd.), the standard automatic printing start method of Dia IF2 After fountain solution and ink were supplied and developed on the machine, printing was performed using Tokuhishi Art (continuous amount 76.5 kg) paper at a printing speed of 10,000 sheets per hour.

Printing was continued after the on-press development described above. As the number of printed sheets was increased, the image recording layer was gradually worn out, so that the ink density on the printed material decreased. Printing durability was evaluated using the number of printed copies when the value measured by the Gretag densitometer for the 3% halftone dot area of the FM screen 3% on the printed material was 5% lower than the measured value for the 100th printed sheet. . The results are shown in Table 1.
A: 20000 or more B: 10,000 or more and less than 20000 C: 5000 or more and less than 10,000 D: Less than 5000

(Scratch resistance)
The obtained lithographic printing plate precursor was subjected to exposure treatment and development treatment, and the lithographic printing plate obtained in an environment of a temperature of 25 ° C. and a humidity of 70% was scratched by a scratch tester. As this scratch tester, HEIDON scratching Interstitial Tester HEIDEN-18 was used, a sapphire needle having a diameter of 0.1 mm was used, and the scratch load was 50 (g). A plate after scratching was printed, and it was evaluated whether or not the scratched portion became print stains. The results are shown in Table 1.
A: Does not cause printing stains B: Slight printing stains that cannot be visually recognized are observed C: Slight printing stains are recognized by visual inspection, but is acceptable D: Scratched parts become printing stains

In Table 1, the “large diameter hole portion average diameter” column represents the average diameter of the large diameter hole portion on the anodized film surface, and the “small diameter hole portion average diameter” column represents the average diameter at the communication position of the small diameter hole portion. Represent.
Further, “large diameter hole depth / betaine ratio” represents (depth of large diameter hole / mol% of repeating unit having betaine structure contained in polymer in undercoat layer used).
In the “undercoat layer type” column, “A” means that the undercoat layer forming coating solution A is used, and “B” means that the undercoat layer forming coating solution B is used. “C” intended to use the coating liquid C for forming the undercoat layer, and “E” intended to use the coating liquid E for forming the undercoat layer.
In the “image recording layer” column, “A” means that the image recording layer forming coating solution A is used, and “B” means that the image recording layer forming coating solution B is used. .

As shown in Table 1 above, the lithographic printing plate precursor according to the present invention provided desired effects.
Especially, it was confirmed from the comparison of Examples 1-6 that an effect is more excellent when the average diameter of a large diameter hole part is 18-50 (preferably 20-40 nm).
Moreover, from the comparison of Example 1 and 7-11, when the depth of the large diameter hole part was 40-180 nm (preferably 70-140 nm), it was confirmed that an effect is more excellent.
Moreover, from the comparison of Examples 1, 7 to 11, and 18, the ratio of the depth of the large pore portion of the micropore to the content of the repeating unit having a betaine structure is 0.8 to 2.4. In some cases, it was confirmed that the effect was more excellent.
Moreover, from the comparison of Example 1 and 14-17, when the depth of the small diameter hole part was 600-2000 nm (preferably 700-2000 nm), it was confirmed that an effect is more excellent.
On the other hand, in the comparative example not satisfying the predetermined requirements, the desired effect was not obtained.

<< Example B: Examples 20-24, Comparative Examples 8-12 >>
From the preparation of the aluminum plate described in paragraph 0537 of JP-A-2003-211859 to the desmut treatment described in paragraph 0546 was performed.
Next, each processing condition from (Aj) the first stage anodizing treatment described in paragraph 0135 of JP2012-158022A to (Am) the third stage anodizing treatment described in paragraph 0138. Were appropriately adjusted to form anodized films having predetermined shapes of Examples and Comparative Examples shown in Table 2 to be described later to obtain an aluminum support.

<Formation of undercoat layer>
On each of the aluminum supports obtained above, the undercoat layer-forming coating solution D was applied so that the dry coating amount was 15 mg / m ² to prepare an aluminum support having an undercoat layer.

(Coating liquid D for undercoat layer formation)
-0.18 parts by mass of the polymer described below (Mw: 100,000)-0.10 parts by mass of tetrasodium ethylenediaminetetraacetate-0.03 parts by mass of polyoxyethylene lauryl ether-61.39 parts by mass of water

  The numerical value at the lower right of the parenthesis of each structural unit in the polymer in the coating liquid D for forming the undercoat layer represents mass%, and the numerical value at the lower right of the parenthesis of the ethyleneoxy unit represents the number of repetitions. .

<Formation of image recording layer>
The image recording layer forming coating solution C was applied onto the undercoat layer by bar coating, and then oven-dried at 100 ° C. for 60 seconds to form an image recording layer having a dry coating amount of 1.0 g / m ² .
The image recording layer forming coating solution C was obtained by mixing the following photosensitive solution (2) and microgel solution (2).

(Photosensitive solution (2))
-Binder polymer (1) [the following structure, Mw: 50,000, n: the number of ethylene oxide (EO) units = 4]): 0.480 parts by mass-Infrared absorber (1) [the following structure]: 0.030 Part by mass / borate compound [sodium tetraphenylborate]: 0.014 part by mass / radical polymerization initiator (1) [following structure]: 0.234 part by mass / radical polymerizable compound [tris (acryloyloxyethyl) isocyanurate , NK ester A-9300, manufactured by Shin-Nakamura Chemical Co., Ltd.]: 0.192 parts by mass Low molecular weight hydrophilic compound (1) [Tris (2-hydroxyethyl) isocyanurate]: 0.052 parts by mass Surfactant 1 [following structure]: 0.099 parts by mass / sensitizing agent Phosphonium compound (1) [following structure]: 0.12 parts by weight / sensitizing agent Ammo Um group-containing polymer [structure shown below, reduced specific viscosity 44 ml / g]: 0.035 parts by mass Sensitizer benzyl dimethyl octyl ammonium-PF ₆ salt: 0.032 parts by mass Colorant Ethyl Violet [following structure: 0.030 parts by mass-Fluorosurfactant (1) [Structure below]: 0.02 parts by mass-2-butanone: 1.091 parts by mass-1-methoxy-2-propanol: 8.609 parts by mass

(Microgel solution (2))
-Microgel (2): 1.580 parts by mass-Distilled water: 1.455 parts by mass

  In addition, Me represents a methyl group, and the numbers on the lower right of the parentheses of the constituent units of the binder polymer (1) and the ammonium group-containing polymer represent a molar ratio.

  The number in the lower right of the parentheses of each constituent unit of the fluorosurfactant (1) represents the molar ratio, and the value in the lower right of the parentheses of the ethyleneoxy unit or propyleneoxy unit represents the number of repetitions. .

The method for synthesizing the microgel (2) is as follows.
-Synthesis of microgel (2)-
10 parts by mass of an adduct of trimethylolpropane and xylene diisocyanate (Mitsui Chemical Polyurethane Co., Ltd., Takenate D-110N), dipentaerythritol pentaacrylate (Sartomer Japan Co., Ltd., SR399) 5.54 mass Part and 0.1 part by mass of Pionein A-41C (manufactured by Takemoto Yushi Co., Ltd.) were dissolved in 17 parts by mass of ethyl acetate to prepare an oil phase component. Moreover, 40 mass parts of 4 mass% aqueous solution of PVA-205 was prepared, and the water phase component was obtained.
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 parts by mass of distilled water, stirred at room temperature (25 ° C.) for 30 minutes, and then stirred at 50 ° C. for 3 hours. The microgel thus obtained was diluted with distilled water to a solid content concentration of 15% by mass, and this was used as the microgel (2). When the average particle diameter of the microgel (2) was measured by a light scattering method, the average particle diameter was 0.2 μm.

<Formation of protective layer>
A protective layer coating solution (2) having the following composition was further applied onto the image recording layer by a bar coater, followed by oven drying at 120 ° C. for 60 seconds to form a protective layer having a dry coating amount of 0.15 g / m ^2. Then, a lithographic printing plate precursor was prepared.
(Protective layer coating solution (2))
Inorganic layered compound dispersion (1) (obtained above): 1.5 parts by mass Hydrophilic polymer (1) (solid content) [the following structure, Mw: 30,000]: 0.55 parts by mass Alcohol (Nippon Synthetic Chemical Co., Ltd. CKS50, sulfonic acid modification | denaturation, saponification degree 99 mol% or more, polymerization degree 300) 6 mass% aqueous solution: 0.10 mass part * polyvinyl alcohol (Kuraray Co., Ltd. PVA-405, Degree of saponification 81.5 mol%, degree of polymerization 500) 6% by mass aqueous solution: 0.03 parts by mass / surfactant (Lapisol A-80, trade name: NOF Corporation)
80% by mass aqueous solution 0.011 part by mass / ion exchange water: 6.0 parts by mass

  In addition, the number on the lower right of the parenthesis of each structural unit of the hydrophilic polymer (1) represents a molar ratio.

<Image exposure>
The lithographic printing plate precursor was exposed with a Luxel PLANETSETTER T-6000III equipped with an infrared semiconductor laser under the conditions of an external drum rotation speed of 1000 rpm, a laser output of 70%, and a resolution of 2400 dpi. The exposed image included a solid image and a 50% halftone dot chart.

<Development processing>
The planographic printing plate precursor was subjected to development processing using the development processing apparatus illustrated in FIG. 2 of JP-A-2009-237162 to obtain a planographic printing plate.
A developer having the following composition was used as the developer used in the development treatment.

(Developer)
・ Anionic surfactant (Perex NBL) 2% by mass
-Nonionic surfactant (New Coal B13) 5% by mass
2-phosphonobutane-1,2,4-tricarboxylic acid (Baihibit AM ™) 2% by mass
・ Benzyl alcohol 0.8% by mass
Antifoaming agent (polydimethylsiloxane, SILCOLAPSE432 manufactured by Bluester Silicones) 0.02% by mass
・ Water 90.18% by mass

Using the lithographic printing plate precursor and the lithographic printing plate obtained in each of Examples 20 to 24 and Comparative Examples 8 to 12, the above UV ink printing durability, neglectability, and scratch resistance were evaluated. Table 2 shows the results.
In the “undercoat layer type” column, “D” meant that the undercoat layer forming coating solution D was used.
In the evaluation of UV ink printing durability, the lithographic printing plate was attached to the plate cylinder of a Mitsubishi Dia IF 2 printing machine by the above development process, and the evaluation was carried out.
In the evaluation of neglectability, the lithographic printing plate was allowed to stand by the above development process under the same conditions as in the above-described neglectability evaluation.
In the “image recording layer” column, “C” means that the image recording layer forming coating solution C is used.

  As shown in Table 2, with the planographic printing plate precursor of the present invention, the desired effect was obtained even if the development format was changed.

DESCRIPTION OF SYMBOLS 10 Planographic printing plate precursor 12 Aluminum support body 14 Undercoat layer 16 Image recording layer 18 Aluminum plate 20 Anodized film 22 Micropore 24 Large diameter hole part 26 Small diameter hole part

Claims (11)

A lithographic printing plate precursor comprising an aluminum support, an undercoat layer, and an image recording layer in this order,
The undercoat layer comprises a compound having a betaine structure or polyvinylphosphonic acid,
The aluminum support includes an aluminum plate and an anodized aluminum film disposed on the aluminum plate;
The anodized film is located on the undercoat layer side of the aluminum plate,
The anodized film has micropores extending in the depth direction from the surface opposite to the aluminum plate,
The micropore communicates with the large-diameter hole extending from the surface of the anodic oxide film to a depth of 20 to 200 nm and the bottom of the large-diameter hole, and the small diameter extending from the communicating position to a depth of 500 to 2000 nm. It consists of a hole and
The average diameter of the large-diameter hole portion on the surface of the anodized film is 15 to 60 nm,
The ratio of the depth of the large-diameter hole to the average diameter of the large-diameter hole is 0.3 to 13.3,
A lithographic printing plate precursor having an average diameter of 13 nm or less at the communication position of the small-diameter hole. The lithographic printing plate precursor according to claim 1, wherein the betaine structure is a structure represented by the formula (i).
R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and R ¹ and R ² are linked to each other to form a ring structure Also good. L ¹ represents a linking group. A ⁻ represents a structure having an anion. * Represents a binding position.   The compound containing a betaine structure is a polymer containing a repeating unit having a betaine structure, a repeating unit having a structure that interacts with the surface of the aluminum support, and a repeating unit having a radical polymerizable reactive group. The lithographic printing plate precursor as claimed in claim 1 or 2. The content of the repeating unit having the betaine structure is 50 to 95% by mass with respect to all the repeating units,
The content of the repeating unit having a structure that interacts with the surface of the aluminum support is 1 to 40% by mass based on all repeating units,
The lithographic printing plate precursor according to claim 3, wherein the content of the repeating unit having a radical polymerizable reactive group is 1 to 30% by mass based on all repeating units.   The planographic printing plate precursor according to any one of claims 1 to 4, wherein an average diameter of the large-diameter hole portion on the surface of the anodic oxide film is 18 to 50 nm.   The lithographic printing plate precursor according to any one of Claims 1 to 5, wherein the large-diameter hole has a depth of 40 to 180 nm.   The lithographic printing plate precursor according to any one of Claims 1 to 6, wherein the image recording layer comprises an acid color former.   The lithographic printing plate precursor as claimed in claim 7, wherein the acid color former is at least one compound selected from the group consisting of a spiropyran compound, a spirooxazine compound, a spirolactone compound, and a spirolactam compound.   The ratio of the depth of the large-diameter hole portion of the micropore to the content of the repeating unit having the betaine structure is 0.8 to 2.4, according to any one of claims 1 to 8. Planographic printing plate. An exposure step of imagewise exposing the lithographic printing plate precursor according to any one of claims 1 to 9 to form an exposed portion and an unexposed portion;
And a removal step of removing an unexposed portion of the lithographic printing plate precursor that has been imagewise exposed. An exposure step of exposing the lithographic printing plate precursor according to any one of claims 1 to 10 imagewise to form an exposed portion and an unexposed portion;
A printing process comprising: supplying at least one of printing ink and fountain solution, removing an unexposed portion of the lithographic printing plate precursor imagewise exposed on a printing machine, and performing printing.