JP5745371B2 - Preparation of lithographic printing plate precursor and lithographic printing plate - Google Patents

Description

  The present invention relates to a lithographic printing plate precursor and a lithographic printing plate preparation method capable of direct plate making using various lasers from a digital signal of a computer or the like, and particularly a lithographic printing plate precursor and lithographic printing plate suitable for simple processing. It relates to a manufacturing method.

  Solid lasers, semiconductor lasers, and gas lasers that emit ultraviolet light, visible light, and infrared light having a wavelength of 300 nm to 1200 nm are easily available in high output and small size. It is very useful as a recording light source when making a plate directly from digital data. Various studies have been made on recording materials that are sensitive to these various laser beams. As a typical example, firstly, positive recording described in Patent Document 1 as a material that can be recorded with an infrared laser having an image recording wavelength of 760 nm or more. Materials, acid-catalyzed cross-linking negative recording materials described in Patent Document 2, and the like. Secondly, there is a radical polymerization type negative recording material described in Patent Document 3 and Patent Document 4 as a recording material for 300 nm to 700 nm ultraviolet light or visible light laser.

In addition, in a conventional lithographic printing plate precursor (hereinafter also referred to as PS plate), after image exposure, a step (development treatment) of dissolving and removing a non-image portion using a strong alkaline aqueous solution is indispensable and developed. A post-treatment step is also necessary in which the printing plate is washed with water, treated with a rinse solution containing a surfactant, or treated with a desensitizing solution containing gum arabic or starch derivatives. The point that these additional wet treatments are indispensable is a big problem for the conventional PS plate. Even if the first half (image exposure) of the plate making process is simplified by the digital processing, the effect of the simplification is insufficient in the wet processing in which the second half (development processing) is complicated.
Particularly in recent years, consideration for the global environment has become a major concern for the entire industry, and from consideration for the environment, processing with a developing solution closer to the neutral range and reduction of waste liquid have been raised as issues. Yes. In particular, it is desirable that the wet post-treatment is simplified or changed to a dry treatment.

  From such a viewpoint, as a method for simplifying the processing step, there is a one-liquid process or a one-bath process in which development and gum solution processing are performed simultaneously. That is, after image exposure of the printing plate precursor without performing the pre-water washing step, the protective layer is removed, the non-image area is removed, and the gum solution treatment is simultaneously performed in one liquid or one bath, and the post-water washing step is not performed. This is a simple development method that enters the printing process. A lithographic printing plate precursor suitable for such simple development has a photosensitive layer that is soluble in a processing solution that is not strongly alkaline, and further improves the stain resistance of non-image areas, because the post-washing step is omitted. In addition, a hydrophilic support surface is required. However, with conventional PS plates, it has been virtually impossible to achieve high printing durability and chemical resistance while satisfying such requirements.

  Therefore, in order to satisfy such a requirement, a lithographic printing plate precursor in which a layer having polyvinylphosphonic acid as a hydrophilic binder polymer is formed on the support surface has been proposed (see, for example, Patent Document 5). In making the plate, after image exposure with an ultraviolet laser, development is performed with a processing solution having a pH of 9.8.

  Therefore, a lithographic printing plate precursor in which the support is hydrophilized with polyvinylphosphonic acid has been proposed in order to satisfy such requirements (see, for example, Patent Document 5). Regarding the plate making, after image exposure with an ultraviolet laser, development is performed with a processing solution having a pH of 9.8.

However, a hydrophilic treatment such as polyvinylphosphonic acid has insufficient hydrophilicity for improving the stain resistance, and there is a problem in the stain resistance as a printing plate.
Further, a lithographic printing plate precursor in which a layer having a monomer having a sulfonic acid group and a binder polymer obtained by copolymerizing a support adsorptive group is formed on the support surface in place of polyvinylphosphonic acid has been proposed (for example, However, hydrophilicity is still insufficient to introduce a hydrophobic polymerizable group for expressing printing durability. Thus, it is extremely difficult to satisfy both printing durability and stain resistance, a simple processing type lithographic printing plate having good stain resistance and sufficient printing durability has not been known so far.

One method of simplifying the processing process is to mount the exposed lithographic printing plate precursor on the cylinder of the printing machine, and supply dampening water and ink while rotating the cylinder. There is a method called on-press development that removes non-image areas. That is, the lithographic printing plate precursor is image-exposed and then mounted on a printing machine as it is, and the development process is completed in a normal printing process.
Such a lithographic printing plate precursor suitable for on-press development has an image forming layer soluble in dampening water or an ink solvent, and is suitable for development on a printing press placed in a bright room. It is necessary to have good light room handling. However, with the conventional PS plate, it is practically impossible to sufficiently satisfy such a requirement.
Therefore, in order to satisfy such requirements, a lithographic printing plate precursor in which a photosensitive layer in which thermoplastic hydrophobic polymer fine particles are dispersed in a hydrophilic binder polymer is provided on a hydrophilic support has been proposed ( For example, see Patent Document 7). In making the plate, image exposure is performed with an infrared laser, and the thermoplastic hydrophobic polymer fine particles are combined (fused) with heat generated by photothermal conversion to form an image. On-press development is performed by supplying at least one of fountain solution and ink. This lithographic printing plate precursor has handleability in a bright room because the image recording area is an infrared region.

However, an image formed by coalescence (fusion) of thermoplastic hydrophobic polymer fine particles has insufficient strength and has a problem in printing durability as a lithographic printing plate.
In addition, a lithographic printing plate precursor including microcapsules encapsulating a polymerizable compound in place of the thermoplastic fine particles has been proposed (see, for example, Patent Documents 8 to 13). The lithographic printing plate precursor according to such a proposal has an advantage that the polymer image formed by the reaction of the polymerizable compound is superior in strength to the image formed by fusing fine particles.
In addition, since the polymerizable compound has high reactivity, many methods for isolating it using microcapsules have been proposed. It has been proposed to use a thermally decomposable polymer for the shell of the microcapsule.

  However, in the conventional lithographic printing plate precursors described in Patent Documents 7 to 13, the printing durability of images formed by laser exposure is not sufficient, and further improvements are required. That is, in these simple processing type lithographic printing plate precursors, a support having a highly hydrophilic surface is used, and as a result, the image portion is easily peeled off from the support by dampening water during printing. Printing durability was not obtained. On the contrary, if the support surface is made hydrophobic, the ink also adheres to the non-image area during printing, and printing stains occur. Thus, it is extremely difficult to achieve both printing durability and stain resistance, an on-press development type lithographic printing plate precursor having good stain resistance and sufficient printing durability has not been known so far. .

  On the other hand, there is known a lithographic printing plate precursor which is provided with a hydrophilic layer having improved adhesion to the surface of a support to improve both printing durability and stain resistance. For example, Patent Document 14 discloses a support for a lithographic printing plate having a hydrophilic layer made of a polymer compound that is chemically bonded directly to the support surface and has a hydrophilic functional group on the support. Yes. Patent Documents 15 and 16 disclose a hydrophilic polymer having a reactive group that can be chemically bonded to an aluminum support or a silicate-treated aluminum support directly or via a component having a crosslinked structure on the surface of the support. A support for a lithographic printing plate having a hydrophilic surface formed by chemically bonding is disclosed. Patent Document 17 has a photosensitive layer containing a polymerization initiator, a polymerizable compound, and a binder polymer that dissolves or swells in water or an aqueous alkali solution on a support, and the photosensitive layer or other layers have an ethylenic property. A lithographic printing plate precursor containing a copolymer comprising a repeating unit having at least one unsaturated bond and a repeating unit having at least one functional group that interacts with the support surface is disclosed. Patent Document 18 discloses, on a support, at least one of a reactive group that can be chemically bonded directly to the surface of the support and a reactive group that can be chemically bonded to the support surface via a crosslinked structure. A hydrophilic layer formed by chemically bonding a hydrophilic polymer having a reactive group and a partial structure having a positive charge and a negative charge to the surface of the support, and an image forming layer in this order. A characteristic lithographic printing plate precursor is disclosed.

  On the other hand, in recent years, in addition to improving both printing durability and stain resistance, it is also possible to improve stain resistance when printing is performed after a lapse of time since the production of a lithographic printing plate, It has been demanded from the viewpoint of easy handling of lithographic printing plates in the printing process. Therefore, in addition to the printing durability and stain resistance, it has been demanded to improve the stain resistance after aging and achieve a high level of balance.

US Pat. No. 4,708,925 JP-A-8-276558 U.S. Pat. No. 2,850,445 Japanese Patent Publication No. 44-20189 JP2009-98590 JP2009-216926 Japanese Patent No. 2938397 JP 2000-2111262 A JP 2001-277740 A JP 2002-29162 A JP 2002-46361 A JP 2002-137562 A JP 2002-326470 A JP 2001-166491 A JP 2003-63166 A JP 2004-276603 A JP 2008-213177 A JP 2007-118579 A

  Under these circumstances, the present inventors examined the lithographic printing plate precursors described in Patent Documents 14 to 18, and found that the stain resistance was still insufficient. In particular, it was found that when printing was carried out after a lapse of time since the lithographic printing plate was produced, there was a problem that particularly the stain resistance was lowered.

  As a factor that the stain resistance and printing durability have decreased, the deterioration of the coated surface after coating and drying of the hydrophilic agent (specific polymer compound) used for the intermediate layer in the conventional lithographic printing plate precursor is a factor. It turned out to be one. Furthermore, since the coated surface shape is further deteriorated when the drying speed is increased, the lithographic printing plate precursors of Patent Documents 14 to 18 are forced to decrease the drying speed and increase the line length during production, and there is a problem that the productivity deteriorates. Had.

  Accordingly, the problem to be solved by the present invention is to provide a lithographic printing plate precursor and a lithographic printing plate production method capable of providing a lithographic printing plate excellent in printing durability, stain resistance and aging resistance after aging. is there.

As a result of intensive studies, the inventors of the present invention have found that the undercoat layer has a copolymer having a molecular weight of 5000 or more having a2) support adsorbing group and (a3) a hydrophilic group, and a molecular weight of less than 5000 having a zwitterionic group. It has been found that the combined use of the components can simultaneously improve the printing durability, stain resistance and stain resistance after aging. That is, it has been found that the above-mentioned problems can be solved by using a lithographic printing plate precursor and a lithographic printing plate preparation method having the following configuration.
The present invention is as follows.

<1> A support, a photosensitive layer provided on the support, and an intermediate layer provided between the support and the photosensitive layer, wherein the intermediate layer (A) has a weight average molecular weight of 5000 or more. And (B) a component having a zwitterionic group and a molecular weight of less than 5000, and the (A) copolymer has (a2) a support adsorbing group and (a3) a hydrophilic group. A lithographic printing plate precursor.
<2> The copolymer (A) includes a repeating unit having at least one support-adsorbing group having a structure represented by the following general formulas (a2-1) to (a2-6) in a side chain. The lithographic printing plate precursor as described in 1>.
(In the general formulas (a2-1) to (a2-6), M ^{1 to} M ⁸ each represent a hydrogen atom, a metal atom contained in an alkali metal or an alkaline earth metal, or ammonium. R ^{41 to} R ⁴⁶ represents a hydrogen atom or an alkyl group, Y ²¹ to Y ²⁶ each represent a single bond, —CO—, —O—, —NH—, a divalent aliphatic group, or a divalent aromatic group. Represents a divalent linking group selected from the group consisting of group groups or combinations thereof. * Represents a site linked to the main chain of the polymer compound.)
<3> The copolymer (A) includes a repeating unit having at least one support adsorbing group having a structure represented by the following general formulas (a2-1) and (a2-2) in the side chain, 2. A lithographic printing plate precursor as described in 2>.
<4> The copolymer (A) includes a repeating unit having at least one hydrophilic group having a structure represented by the following general formulas (a3-1) to (a3-5) in a side chain. The lithographic printing plate precursor as described in any one of> to <3>.
(In General Formula (a3-1), R ³¹ and R ³² each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and R ³¹ and R ³² are linked to each other. , Which may form a ring structure, L ³¹ represents a linking group, A ⁻ represents a structure having an anion, Y ³ represents a single bond, —CO—, —O—, —NH—, 2 A divalent linking group selected from the group consisting of a valent aliphatic group, a divalent aromatic group, or a combination thereof, * represents a site linked to the main chain of the copolymer.)
(In the general formula (a3-2), L ³² represents a linking group, and E ⁺ represents a structure having a cation. Y ⁴ represents a single bond, —CO—, —O—, —NH—, divalent. A divalent linking group selected from the group consisting of an aliphatic group, a divalent aromatic group, or a combination thereof, * represents a site linked to the main chain of the copolymer.
(In General Formula (a3-3), Y ³ represents a single bond, —CO—, —O—, —NH—, a divalent aliphatic group, a divalent aromatic group, or a combination thereof. Represents a divalent linking group selected from the group consisting of: * represents a site linked to the main chain of the copolymer, M represents a hydrogen atom or a monovalent metal atom.)
(In General Formula (a3-4), R ³³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may be substituted. Y ³ represents a single bond, —CO—, —O—, — NH— represents a divalent linking group selected from the group consisting of a divalent aliphatic group, a divalent aromatic group, or a combination thereof, where * represents a site linked to the main chain of the copolymer. Represents.)
(In General Formula (a3-5), R ³³ represents a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms. Y ³ represents a single bond, —CO—, —O—, — NH— represents a divalent linking group selected from the group consisting of a divalent aliphatic group, a divalent aromatic group, or a combination thereof, where * represents a site linked to the main chain of the copolymer. A ⁻ represents a structure having an anion.)
<5> The lithographic printing according to <4>, wherein the (A) copolymer includes a repeating unit having at least one hydrophilic group having a structure represented by the following general formula (a3-1) in a side chain. Version original edition.
<6> The lithographic printing plate precursor as described in any one of <1> to <5>, wherein the (A) copolymer further has (a1) a crosslinkable group in the side chain.
<7> The component (B) having a zwitterionic group and having a molecular weight of less than 5000 has at least one structure represented by the following general formulas (b1-1) to (b1-8), <1> to <1. 6. The lithographic printing plate precursor as described in any one of 6>.
(In the general formulas (b1-1) to (b1-8), R may have a hydrogen atom or a substituent, may be saturated or unsaturated, and may be linear, cyclic or branched. 15 represents an alkyl group, L represents a divalent linking group, Q represents an n-valent linking group, n represents an integer of 2 or more, A ⁻ represents a structure having an anion, E ⁺ represents a cation Represents a structure having
<8> The lithographic plate according to <7>, wherein R may have a hydrogen atom or a substituent, may be saturated or unsaturated, and may be a linear, cyclic, or branched alkyl group having 1 to 5 carbon atoms A printing plate master.
<9> A structure in which the component (B) having a zwitterionic group and having a molecular weight of less than 5000 is represented by the general formula (b1-1), (b1-2), (b1-5) or (b1-6). The lithographic printing plate precursor as described in <7> or <8>, having at least one.
<10> Any one of <1> to <9>, wherein the copolymer (A) includes a repeating unit represented by the following general formula (A2) and a repeating unit represented by the general formula (A3). The lithographic printing plate precursor as described in the paragraph.
(In the general formula (A2), R _a ′ to R _c ′ each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom. (A2) represents the above general formulas (a2-1) to ( It represents the structure represented by a2-6), and is linked to the carbon atom at the site represented by * in general formulas (a2-1) to (a2-6).
(In the general formula (A3), R ²⁰¹ ~R ²⁰³ are respectively represented by a hydrogen atom, an alkyl group or a halogen atom having 1 to 6 carbon atoms. Formula (a3-1) ~ (a3-5) And is linked to a carbon atom at a site represented by * in the general formulas (a3-1) to (a3-5).
(In the general formulas (a2-1) to (a2-6), M ^{1 to} M ⁸ each represent a hydrogen atom, a metal atom contained in an alkali metal or an alkaline earth metal, or ammonium. R ^{41 to} R ⁴⁶ represents a hydrogen atom or an alkyl group, Y ²¹ to Y ²⁶ each represent a single bond, —CO—, —O—, —NH—, a divalent aliphatic group, or a divalent aromatic group. Represents a divalent linking group selected from the group consisting of group groups or combinations thereof. * Represents a site linked to the main chain of the polymer compound.)
(In General Formula (a3-1), R ³¹ and R ³² each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and R ³¹ and R ³² are linked to each other. , Which may form a ring structure, L ³¹ represents a linking group, A ⁻ represents a structure having an anion, Y ³ represents a single bond, —CO—, —O—, —NH—, 2 A divalent linking group selected from the group consisting of a valent aliphatic group, a divalent aromatic group, or a combination thereof, * represents a site linked to the main chain of the copolymer.)
(In the general formula (a3-2), L ³² represents a linking group, and E ⁺ represents a structure having a cation. Y ⁴ represents a single bond, —CO—, —O—, —NH—, divalent. A divalent linking group selected from the group consisting of an aliphatic group, a divalent aromatic group, or a combination thereof, * represents a site linked to the main chain of the copolymer.
(In General Formula (a3-3), Y ³ represents a single bond, —CO—, —O—, —NH—, a divalent aliphatic group, a divalent aromatic group, or a combination thereof. Represents a divalent linking group selected from the group consisting of: * represents a site linked to the main chain of the copolymer, M represents a hydrogen atom or a monovalent metal atom.)
(In General Formula (a3-4), R ³³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may be substituted. Y ³ represents a single bond, —CO—, —O—, — NH— represents a divalent linking group selected from the group consisting of a divalent aliphatic group, a divalent aromatic group, or a combination thereof, where * represents a site linked to the main chain of the copolymer. Represents.)
(In General Formula (a3-5), R ³³ represents a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms. Y ³ represents a single bond, —CO—, —O—, — NH— represents a divalent linking group selected from the group consisting of a divalent aliphatic group, a divalent aromatic group, or a combination thereof, where * represents a site linked to the main chain of the copolymer. A ⁻ represents a structure having an anion.)
<11> The lithographic printing plate precursor as described in any one of <6 to 10, wherein the crosslinkable group is represented by any one of the following general formulas (i) to (iii).
(In General Formula (i), R ^{1 to} R ³ each represents a hydrogen atom or a monovalent organic group. X represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —, and R ¹² Represents a hydrogen atom or a monovalent organic group.)
(In General Formula (ii), R ^{4 to} R ⁸ each represent a hydrogen atom or a monovalent organic group. Y represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —, and R ¹² Represents a hydrogen atom or a monovalent organic group.)
(In general formula (iii), R ^{9 to} R ¹¹ each represent a hydrogen atom or a monovalent organic group. Z has an oxygen atom, a sulfur atom, —N (R ¹³ ) — or a substituent. R ¹³ represents a hydrogen atom or an alkyl group that may have a substituent.
<12> The lithographic plate according to any one of <1> to <11>, wherein the photosensitive layer contains (C) a polymerization initiator, (D) a polymerizable compound, (E) a binder, and (F) a dye. A printing plate master.
<13> The lithographic printing plate precursor as described in <12>, wherein the (E) binder is at least one of a (meth) acrylic resin, a polyurethane resin, and a polyvinyl butyral resin.
<14> The lithographic printing plate precursor as described in <12> or <13>, wherein the polymerizable compound (D) has a urethane structure.
<15><1> to the step of exposing the lithographic printing plate precursor according to any one of <14> imagewise,
A method for producing a lithographic printing plate, comprising a step of removing the exposed lithographic printing plate precursor in the presence of a developer having a pH of 2 to 14 in the non-exposed portion of the photosensitive layer.
<16> including a step of forming a protective layer on the surface of the photosensitive layer opposite to the support;
The developing step further includes a step of removing the photosensitive layer in the non-exposed area and the protective layer at the same time in the presence of the developer containing a surfactant (but not including a washing step). <15> The manufacturing method of the lithographic printing plate as described in <15>.
<17> The method for producing a lithographic printing plate as described in <15> or <16>, comprising a step of controlling the pH of the developer to 2.0 to 10.0.
<18> The step of exposing the lithographic printing plate precursor according to any one of <1> to <14>imagewise;
A method for producing a lithographic printing plate, comprising: supplying printing ink and fountain solution on a printing machine to remove the photosensitive layer in the non-exposed portion.

  According to the configuration of the present invention, it is possible to provide a lithographic printing plate and a lithographic printing plate production method that are excellent in printing durability, stain resistance, and stain resistance after aging.

It is explanatory drawing which shows the structure of an automatic developing processor. It is explanatory drawing which shows the structure of an automatic developing processor.

Hereinafter, the contents of the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
In the present specification, regarding the notation of the group in the compound represented by the general formula, when there is no substitution or no substitution, there is no other special provision when the group can further have a substituent. As long as it includes not only an unsubstituted group but also a group having a substituent. For example, in the general formula, if there is a description that “R represents an alkyl group, an aryl group or a heterocyclic group”, “R represents an unsubstituted alkyl group, a substituted alkyl group, an unsubstituted aryl group, a substituted aryl group, an Represents a substituted heterocyclic group or a substituted heterocyclic group. Moreover, in this specification, (meth) acrylamide represents the concept containing both methacrylamide and acrylamide.

[Lithographic printing plate precursor]
Hereinafter, the lithographic printing plate precursor according to the invention will be described in detail.
The lithographic printing plate precursor according to the invention includes a support, a photosensitive layer provided on the support, and an intermediate layer provided between the support and the photosensitive layer. A copolymer having a molecular weight of 5000 or more, and (B) a component having a molecular weight of less than 5000 having a zwitterionic group, wherein the (A) copolymer comprises (a2) a support adsorbing group and (a3) a hydrophilic group. It is characterized by having. The (A2) copolymer having (a2) support adsorbing group and (a3) hydrophilic group is also referred to as a specific polymer compound hereinafter. The component (B) having a zwitterionic group and having a molecular weight of less than 5000 is also referred to as a specific low molecular compound hereinafter.

  Although not limited to any reason, the lithographic printing plate precursor according to the present invention contains (A) a copolymer and (B) a specific low molecular weight compound in the undercoat layer, so that the effects of the present invention are achieved for the following reasons. Presumed to have been expressed. Since the copolymer (A) having a hydrophilic group has high polarity, it is assumed that the polymer aggregates in a coating solution to form a string. By adding the specific low molecular weight compound (B) there, the ion concentration in the solution is increased, the stabilization by the solvation of the polymer is promoted, and the aggregation is released. Therefore, it is possible to obtain a support surface that suppresses defective coating surface conditions in which the copolymer (A) generated by coating and drying the substrate in an aggregated state coats the substrate while being a string. (A) By releasing the aggregation of the copolymer, the substrate surface can be uniformly coated without deteriorating the coated surface state even under various drying conditions. As a result, the lithographic printing plate can provide a lithographic printing plate that is very excellent in stain resistance and stability over time, which is the object of the present invention, further excellent in printing durability (preferably excellent in developability), and improved in productivity. It has become possible to provide a method for producing a printing plate precursor and a lithographic printing plate.

  The lithographic printing plate precursor according to the invention is preferably capable of so-called direct plate making, which can be directly made using various lasers from a digital signal from a computer or the like. In particular, it is preferable that development is possible even in an aqueous solution having a pH of 2.0 to 10.0 or a printing press.

Hereinafter, preferred embodiments of the lithographic printing plate precursor according to the invention will be described in detail.
The lithographic printing plate precursor according to the invention includes a support and a photosensitive layer provided on the support. Furthermore, the lithographic printing plate precursor according to the invention is provided with an undercoat layer as an intermediate layer between the support and the photosensitive layer. Furthermore, the lithographic printing plate precursor according to the invention may have other constituent layers. In the present invention, the support and the intermediate layer are preferably in contact with each other, and the support, the intermediate layer, and the photosensitive layer are more preferably in contact with each other in this order. However, an intermediate layer (undercoat layer) may be further provided between the support and the intermediate layer and between the intermediate layer and the photosensitive layer without departing from the spirit of the present invention. The lithographic printing plate precursor according to the invention preferably includes a protective layer on the surface of the photosensitive layer opposite to the support. Moreover, the lithographic printing plate precursor according to the invention can be provided with a backcoat layer on the back surface of the support, if necessary.
Hereinafter, the intermediate layer, photosensitive layer, other layers, protective layer, and backcoat layer constituting the lithographic printing plate precursor according to the invention will be described in order, and the method for forming the lithographic printing plate precursor according to the invention will be described.

<Intermediate layer>
In the lithographic printing plate precursor according to the invention, the intermediate layer includes (A) a copolymer having a molecular weight of 5000 or more and (B) a component having a zwitterionic group and a molecular weight of less than 5000, and the copolymer (A) (A2) It has a support adsorbing group and (a3) a hydrophilic group. Moreover, the said intermediate | middle layer can contain another component further as needed.
Hereinafter, for the sake of explanation, in the intermediate layer, (A) a copolymer (specific polymer compound) and (B) a component having a molecular weight of less than 5000 (specific low molecular compound) having a zwitterionic group will be described in detail.

(A) Copolymer (specific polymer compound)
The copolymer in the present invention is characterized in that it has (a2) a support adsorbing group and (a3) a hydrophilic group, 95 mol% or more of the main chain is composed of carbon-carbon bonds, and the side chain has (A2) It preferably has a support adsorbing group and (a3) a hydrophilic group.

(A2) Support Adsorbing Group The specific polymer compound is characterized by having (a2) a support adsorbing group. The support adsorbing group is a group having a function of bringing a specific polymer compound and a support into close contact with each other using van der Waals interaction force, electrostatic interaction force, covalent bond force, ionic bond force, or coordination bond force. Represents.

Depending on the type of support, suitable functional groups differ, but for metal supports generally used in lithographic printing plate precursors, acidic groups and hydroxy groups are preferred, and the structure is such that chelate coordination is possible. More preferably. In particular, it is preferably a repeating unit having at least one of structures represented by the following general formulas (a2-1) to (a2-6) in the side chain.
(In the general formulas (a2-1) to (a2-6), M ^{1 to} M ⁸ each represent a hydrogen atom, a metal atom contained in an alkali metal or an alkaline earth metal, or ammonium. R ^{41 to} R ⁴⁶ represents a hydrogen atom or an alkyl group, Y ²¹ to Y ²⁶ each represent a single bond, —CO—, —O—, —NH—, a divalent aliphatic group, or a divalent aromatic group. Represents a divalent linking group selected from the group consisting of group groups or combinations thereof. * Represents a site linked to the main chain of the polymer compound.)

In the above formula, each of R ^{41 to} R ⁴⁶ is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Examples of the alkyl group represented by R ^{41 to} R ⁴⁶ include a methyl group, an ethyl group, a propyl group, an octyl group, an isopropyl group, a tert-butyl group, an isopentyl group, a 2-ethylhexyl group, a 2-methylhexyl group, and a cyclopentyl group. Etc.

In the above formula, examples of the combination of Y ^{21 to} Y ²⁶ include the following. In the following examples, the left side is bonded to the main chain.
L1: -CO-O-2 valent aliphatic group-
L2: -CO-O-2 valent aromatic group-
L3: -CO-NH-2 valent aliphatic group-
L4: -CO-NH-2 valent aromatic group-

Here, the divalent aliphatic group means an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group, a substituted alkynylene group or a polyalkyleneoxy group. Of these, an alkylene group, a substituted alkylene group, an alkenylene group, and a substituted alkenylene group are preferable, and an alkylene group and a substituted alkylene group are more preferable.
The divalent aliphatic group preferably has a chain structure rather than a cyclic structure, and more preferably has a straight chain structure than a branched chain structure. The number of carbon atoms of the divalent aliphatic group is preferably 1 to 20, more preferably 1 to 15, further preferably 1 to 12, and further preferably 1 to 10. Preferably, it is 1-8.
Examples of the substituent of the divalent aliphatic group include a halogen atom (F, Cl, Br, I), a hydroxy group, a carboxy group, an amino group, a cyano group, an aryl group, an alkoxy group, an aryloxy group, and an acyl group. An acyloxy group, a monoalkylamino group, a dialkylamino group, an arylamino group, a diarylamino group, and the like.

The divalent aromatic group means a divalent monocyclic or polycyclic aromatic hydrocarbon group. Specific examples of the divalent aromatic group include, for example, 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, biphenyl-4,4′-diyl group, diphenylmethane-4, Examples thereof include 4′-diyl group, 3,3′-dimethylbiphenyl-4,4′-diyl group, 1,2-naphthalene group, 1,5-naphthalene group, 2,6-naphthalene group and the like.
Examples of the substituent of the divalent aromatic group include an alkyl group in addition to the examples of the substituent of the divalent aliphatic group.

Y ^{21 to} Y ²⁶ are preferably a single bond, a divalent aromatic group, L1, L2, L3 and L4, and more preferably a single bond, L1 and L2.

M ^{1 to} M ⁸ are each preferably a hydrogen atom or a metal atom contained in an alkali metal, and more preferably a hydrogen atom. As the alkali metal, sodium is preferable.

Among the structures represented by the general formulas (a2-1) to (a2-6), from the viewpoint of stain resistance and printing durability, the structure that interacts with the surface of the support is represented by the general formula (a2-1). ), (A2-2) and (a2-6) are preferable, and a structure represented by the general formula (a2-1) or (a2-2) is more preferable.
Further, in both the structure represented by the general formula (a2-1) and the structure represented by the general formula (a2-2), M ¹ and M ² and M ³ and M ⁴ are hydrogen atoms, respectively. Is preferred.
Further, from the viewpoint of stain resistance and printing durability, the functional group that interacts with the support surface is a group containing the above carboxylic acid, a sulfonic acid group, a phosphate ester group or a salt thereof, a phosphonic acid group or a salt thereof. A salt is preferred.

The repeating unit (a2) having at least one structure that interacts with the support surface is preferably a repeating unit represented by the following general formula (A2).
(In the general formula (A2), R _a ′ to R _c ′ each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom. (A2) represents the above general formulas (a2-1) to ( It represents the structure represented by a2-6), and is linked to the carbon atom at the site represented by * in general formulas (a2-1) to (a2-6).
R _a ′ to R _c ′ are each preferably a hydrogen atom or a methyl group. R _a ′ and R _b ′ are more preferably a hydrogen atom.

  In the copolymer (A), the ratio of the repeating unit (a2) having the structure represented by the general formulas (a2-1) to (a2-6) is all repeated from the viewpoint of stain resistance and developability. The range is preferably from 1 to 99% by weight of the unit, more preferably from 10 to 90% by weight, and even more preferably from 20 to 70% by weight.

  Specific examples of the structure represented by the general formulas (a2-1) to (a2-6) include the following structures, but the present invention is not limited to the following specific examples. Absent.

(A3) Repeating unit having hydrophilic group in side chain:
The copolymer (A) used in the present invention preferably has (a3) a repeating unit containing at least one hydrophilic group in the side chain in order to make the support surface of the non-image area highly hydrophilic. . The hydrophilic group refers to one that easily forms a hydrogen bond, van der Waals bond, or ionic bond with a water molecule, and is selected from monovalent or divalent or more hydrophilic groups, specifically a hydroxy group, Examples thereof include a carboxyl group, an amino group, a sulfo group, a group having a positive charge or a negative charge, a zwitterionic group or a metal salt thereof. Among them, for example, hydroxy group, sulfonic acid group, alkyleneoxy group such as ethyleneoxy group and propyleneoxy group, quaternary ammonium group, amide group, group containing ether group bond, or carboxylic acid, sulfonic acid, phosphoric acid A salt obtained by neutralizing an acid group such as a heterocyclic group containing a positively charged nitrogen atom is preferred. These hydrophilic groups may also serve as a repeating unit (a2) having in the side chain a structure that interacts with the support surface.

In the present invention, the repeating unit (a3) having a hydrophilic group in the side chain is preferably an acid group, an amino group, or a quaternary group, and is a repeating unit having a zwitterionic structure in the side chain. However, it is particularly preferable from the viewpoint of making the support surface of the non-image area highly hydrophilic.
In the lithographic printing plate precursor according to the invention, the hydrophilic group contained in the copolymer (A) is preferably represented by the following general formulas (a3-1) to (a3-5). -1) or (a3-2) is more preferable, and the general formula (a3-1) is more preferable.

(In General Formula (a3-1), R ³¹ and R ³² each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and R ³¹ and R ³² are linked to each other. , Which may form a ring structure, L ³¹ represents a linking group, A ⁻ represents a structure having an anion, Y ³ represents a single bond, —CO—, —O—, —NH—, 2 A divalent linking group selected from the group consisting of a valent aliphatic group, a divalent aromatic group, or a combination thereof, * represents a site linked to the main chain of the copolymer.)
(In the general formula (a3-2), L ³² represents a linking group, and E ⁺ represents a structure having a cation. Y ⁴ represents a single bond, —CO—, —O—, —NH—, divalent. A divalent linking group selected from the group consisting of an aliphatic group, a divalent aromatic group, or a combination thereof, * represents a site linked to the main chain of the copolymer.
(In General Formula (a3-3), Y ³ represents a single bond, —CO—, —O—, —NH—, a divalent aliphatic group, a divalent aromatic group, or a combination thereof. Represents a divalent linking group selected from the group consisting of: * represents a site linked to the main chain of the copolymer, M represents a hydrogen atom or a monovalent metal atom.)
(In General Formula (a3-4), R ³³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may be substituted. Y ³ represents a single bond, —CO—, —O—, — NH— represents a divalent linking group selected from the group consisting of a divalent aliphatic group, a divalent aromatic group, or a combination thereof, where * represents a site linked to the main chain of the copolymer. Represents.)
(In General Formula (a3-5), R ³³ represents a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms. Y ³ represents a single bond, —CO—, —O—, — NH— represents a divalent linking group selected from the group consisting of a divalent aliphatic group, a divalent aromatic group, or a combination thereof, where * represents a site linked to the main chain of the copolymer. A ⁻ represents a structure having an anion.)

In the general formula (a3-1), the ring structure formed by connecting R ³¹ and R ³² to each other may have a heteroatom such as an oxygen atom, preferably a 5- to 10-membered ring, more preferably Is a 5- or 6-membered ring.
The carbon number of R ³¹ and R ³² is preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and more preferably 1 to 15 carbon atoms, including the carbon number of the substituent which may be described later. Particularly preferred, C1-C8 is most preferred.

Examples of the alkyl group represented by R ³¹ and R ³² include methyl group, ethyl group, propyl group, octyl group, isopropyl group, tert-butyl group, isopentyl group, 2-ethylhexyl group, 2-methylhexyl group, A cyclopentyl group etc. are mentioned.
Examples of the alkenyl group represented by R ³¹ and R ³² include a vinyl group, an allyl group, a prenyl group, a geranyl group, and an oleyl group.
Examples of alkynyl groups represented by R ³¹ and R ³² include ethynyl group, propargyl group, trimethylsilylethynyl group and the like.
Examples of the aryl group represented by R ³¹ and R ³² include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group. Furthermore, examples of the heterocyclic group include a furanyl group, a thiophenyl group, and a pyridinyl group.

These groups represented by R ³¹ and R ³² may further have a substituent. Examples of the substituent include halogen atom (F, Cl, Br, I), hydroxy group, carboxy group, amino group, cyano group, aryl group, alkoxy group, aryloxy group, acyl group, alkoxycarbonyl group, aryloxy Examples include a carbonyl group, an acyloxy group, a monoalkylamino group, a dialkylamino group, a monoarylamino group, and a diarylamino group.

As R ³¹ and R ³² , from the viewpoints of effects and availability, particularly preferred examples include a hydrogen atom, a methyl group, or an ethyl group.

The divalent linking group represented by Y ³ consists of a single bond, —CO—, —O—, —NH—, a divalent aliphatic group, a divalent aromatic group, or a combination thereof. Represents a divalent linking group selected from the group;

Specific examples of Y ³ comprising the above combinations are given below. In the following examples, the left side is bonded to the main chain.
L101: -CO-O-2 valent aliphatic group-
L102: -CO-O-2 valent aromatic group-
L103: -CO-NH-2 valent aliphatic group-
L104: -CO-NH-2 valent aromatic group-
L105: -CO-2 valent aliphatic group-
L106: -CO-2 valent aromatic group-
L107: -CO-2 valent aliphatic group -CO-O-2 valent aliphatic group-
L108: -CO-2 valent aliphatic group -O-CO-2 valent aliphatic group-
L109: -CO-2 valent aromatic group -CO-O-2 valent aliphatic group-
L110: -CO-2 valent aromatic group -O-CO-2 valent aliphatic group-
L111: -CO-2 valent aliphatic group -CO-O-2 valent aromatic group-
L112: -CO-2 valent aliphatic group -O-CO-2 valent aromatic group-
L113: -CO-2 valent aromatic group -CO-O-2 valent aromatic group-
L114: -CO-2 valent aromatic group -O-CO-2 valent aromatic group-
L115: -CO-O-2 valent aromatic group -O-CO-NH-2 valent aliphatic group-
L116: -CO-O-2 valent aliphatic group -O-CO-NH-2 valent aliphatic group-

Here, the divalent aliphatic group means an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group, a substituted alkynylene group or a polyalkyleneoxy group. Of these, an alkylene group, a substituted alkylene group, an alkenylene group, and a substituted alkenylene group are preferable, and an alkylene group and a substituted alkylene group are more preferable.
The divalent aliphatic group is preferably a chain structure rather than a cyclic structure, and more preferably a linear structure than a branched chain structure. The number of carbon atoms of the divalent aliphatic group is preferably 1-20, more preferably 1-15, still more preferably 1-12, and still more preferably 1-10. Preferably, it is 1-8.
Examples of the substituent of the divalent aliphatic group include halogen atom (F, Cl, Br, I), hydroxy group, carboxy group, amino group, cyano group, aryl group, alkoxy group, aryloxy group, monoalkyl Examples thereof include an amino group, a dialkylamino group, an arylamino group, and a diarylamino group.

The divalent aromatic group means a divalent monocyclic or polycyclic aromatic hydrocarbon group. Specific examples of the divalent aromatic group include, for example, 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, biphenyl-4,4′-diyl group, diphenylmethane-4, Examples thereof include 4′-diyl group, 3,3′-dimethylbiphenyl-4,4′-diyl group, 1,2-naphthalene group, 1,5-naphthalene group, 2,6-naphthalene group and the like.
Examples of the substituent of the divalent aromatic group include an alkyl group in addition to the examples of the substituent of the divalent aliphatic group.

Among them, Y ³ is preferably a single bond, —CO—, a divalent aliphatic group, a divalent aromatic group, or L101 to L104. Further, from the viewpoint of stain resistance, Y ³ is preferably L101 or L103, and more preferably L103. Further, the divalent aliphatic group of L103 is preferably a linear alkylene group having 2 to 4 carbon atoms, and most preferably a linear alkylene group having 3 carbon atoms in terms of synthesis.

L ³¹ represents a linking group, preferably a linking group composed of —CO—, —O—, —NH—, a divalent aliphatic group, a divalent aromatic group, and a combination thereof, The carbon number is 30 or less including the carbon number of the substituent which may be described later. Specific examples thereof include an alkylene group (preferably having 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms) and an arylene group such as phenylene and xylylene (preferably having 5 to 15 carbon atoms, more preferably having a carbon number). 6 to 10). Among these, from the viewpoint of stain resistance, L ³¹ is preferably a linear alkylene group having 3 to 5 carbon atoms, more preferably a linear alkylene group having 4 or 5 carbon atoms, and most preferably a linear alkylene group having 4 carbon atoms. preferable.
Specific examples of L ³¹ include the following linking groups.

In addition, these coupling groups may further have a substituent.
Examples of the substituent include halogen atom (F, Cl, Br, I), hydroxy group, carboxy group, amino group, cyano group, aryl group, alkoxy group, aryloxy group, acyl group, alkoxycarbonyl group, aryloxy Examples include a carbonyl group, an acyloxy group, a monoalkylamino group, a dialkylamino group, a monoarylamino group, and a diarylamino group.

In the general formula (a3-1), A ⁻ preferably represents a carboxylate, a sulfonate, a phosphate, a phosphonate, or a phosphinate.
Specific examples include the following anions.

From the standpoint of stain resistance, A ^- and most preferably is sulfonate. Further, in the general formula (a1-1), L ³¹ is a linear alkylene group having 4 or 5 carbon atoms, and A ⁻ is a combination of sulfonate, and L ³¹ is a linear alkylene having 4 carbon atoms. Most preferred is a combination of the groups and A ^- is sulfonate.

Y ³ is L101 or L103, R ³¹ and R ³² are ethyl groups or methyl groups, L ³¹ is a linear alkylene group having 4 or 5 carbon atoms, and A ⁻ is a sulfonate group. preferable.
More preferably, Y ³ is L103, R ³¹ and R ³² are methyl groups, L ³¹ is a linear alkylene group having 4 carbon atoms, and A ⁻ is sulfonate.

Next, the zwitterionic structure represented by the following general formula (a3-2) will be described.
In the general formula (a3-2), L ³² represents a linking group, preferably —CO—, —O—, —NH—, a divalent aliphatic group, a divalent aromatic group, and combinations thereof. Selected from the group consisting of Specific examples and preferred examples thereof are the same as the linking group represented by L ³¹ described above.
Y ⁴ has the same meaning as Y ^{3 in} formula (a3-2), and preferred examples are also the same.
E ⁺ represents a structure having a cation, and preferably represents a structure having ammonium, phosphonium, iodonium, or sulfonium. A structure having ammonium or phosphonium is more preferable, and a structure having ammonium is particularly preferable. Examples of structures having a cation include trimethylammonio group, triethylammonio group, tributylammonio group, benzyldimethylammonio group, diethylhexylammonio group, (2-hydroxyethyl) dimethylammonio group, pyridinio group, N-methylimidazolio group, N-acridinio group, trimethylphosphonio group, triethylphosphonio group, triphenylphosphonio group and the like can be mentioned.
In the most preferable combination of L ³² , Y ⁴ and E ⁺ , L ³² is an alkylene group having 2 to 4 carbon atoms, Y ⁴ is L101 or L103, and E ⁺ is a trimethylammonio group or triethylammoni. Oh group.

In the general formula (a3-3) ~ (a3-5), Y 3 has the same meaning as Y ³ in the general formula (a3-1), the preferred range is also the same. M is preferably a hydrogen atom or a sodium atom.
R ³³ is preferably a hydrogen atom or a methyl group.

  In this invention, it is preferable to have a repeating unit represented by the following general formula (A3) as a repeating unit containing a hydrophilic group (a3).

(In the general formula (A3), R ²⁰¹ ~R ^203, respectively, .G represents a hydrogen atom, an alkyl group or a halogen atom having 1 to 6 carbon atoms, the general formula (a3-1) ~ (a3-5) And is linked to a carbon atom at a site represented by * in the general formulas (a3-1) to (a3-5).
R ^{201 to} R ²⁰³ are each preferably a hydrogen atom or a methyl group. R ²⁰¹ and R ²⁰² are more preferably a hydrogen atom.

  In the general formula (A3), the side chain G is preferably the general formula (a3-1) or (a3-2), and more preferably the general formula (a3-1).

  In the present invention, the ratio of (a3) the repeating unit having a hydrophilic group in the side chain to the total repeating unit constituting the copolymer (A) is determined from the viewpoint of stain resistance and developability. The range is preferably 1 to 80% by weight of the unit, more preferably 5 to 60% by weight, and still more preferably 10 to 50% by weight.

  Specific examples of the hydrophilic group structure represented by the general formulas (a3-1) to (a3-5) include the following structures.

  Furthermore, the specific polymer compound in the present invention can be provided with crosslinkability in order to improve the film strength of the image area. In order to give the specific polymer compound crosslinkability, a crosslinkable functional group may be introduced into the main chain or side chain of the polymer compound. The crosslinkable functional group may be introduced by copolymerization or may be introduced by a polymer reaction.

  Here, the crosslinkable functional group is a group having a function of crosslinking the binder polymer in the process of radical polymerization reaction that occurs in the image recording layer when the lithographic printing plate precursor is exposed. Although it will not specifically limit if it is group which has such a function, For example, an ethylenically unsaturated bond group, an epoxy group, etc. are mentioned as a functional group which can be addition-polymerized. Moreover, the functional group which can become a radical by light irradiation may be sufficient, As such a crosslinkable functional group, a thiol group, a halogen group, an onium salt structure etc. are mentioned, for example. Especially, an ethylenically unsaturated bond group is preferable and the functional group represented by the following general formula (i)-(iii) is especially preferable.

(In General Formula (i), R ^{1 to} R ³ each represents a hydrogen atom or a monovalent organic group. X represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —, and R ¹² Represents a hydrogen atom or a monovalent organic group.)

R ¹ is preferably a hydrogen atom or an alkyl group which may have a substituent. Among them, a hydrogen atom or a methyl group is preferable because of high radical reactivity.
R ² and R ³ are each preferably a hydrogen atom, a halogen atom, an amino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an alkyl group which may have a substituent, or a substituent. An aryl group that may have a substituent, an alkoxy group that may have a substituent, an aryloxy group that may have a substituent, an alkylamino group that may have a substituent, and a substituent Arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, a substituent may be mentioned. An alkyl group that may have an aryl group that may have a substituent is preferable because of high radical reactivity.

Examples of the monovalent organic group include an alkyl group which may have a substituent. Since X has both hydrophilicity and crosslinkability, X is preferably —N (R ¹² ) —, particularly preferably —NH—.
R ¹² is preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group because of high radical reactivity.

  Examples of substituents that can be introduced include alkyl groups, alkenyl groups, alkynyl groups, aryl groups, alkoxy groups, aryloxy groups, halogen atoms, amino groups, alkylamino groups, arylamino groups, carboxyl groups, alkoxycarbonyl groups, sulfo groups, A nitro group, a cyano group, an amide group, an alkylsulfonyl group, an arylsulfonyl group and the like can be mentioned.

(In General Formula (ii), R ^{4 to} R ⁸ each represent a hydrogen atom or a monovalent organic group. Y represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —, and R ¹² Represents a hydrogen atom or a monovalent organic group.)

R ^{4 to} R ⁸ are each preferably a hydrogen atom, a halogen atom, an amino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an alkyl group which may have a substituent, or a substituent. An aryl group that may have a substituent, an alkoxy group that may have a substituent, an aryloxy group that may have a substituent, an alkylamino group that may have a substituent, and a substituent Arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, a substituent may be mentioned. The alkyl group which may have and the aryl group which may have a substituent are preferable.

Examples of the substituent that can be introduced include the same substituents as those described in formula (i).
Y represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —. R ¹² has the same meaning as R ^{12 in} formula (i), and preferred examples thereof are also the same.

(In general formula (iii), R ^{9 to} R ¹¹ each represent a hydrogen atom or a monovalent organic group. Z has an oxygen atom, a sulfur atom, —N (R ¹³ ) — or a substituent. R ¹³ represents a hydrogen atom or an alkyl group that may have a substituent.

R ⁹ is preferably a hydrogen atom or an alkyl group which may have a substituent. Among them, a hydrogen atom or a methyl group is preferable because of high radical reactivity.
R ¹⁰ and R ¹¹ are each preferably a hydrogen atom, a halogen atom, an amino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an alkyl group which may have a substituent, or a substituent. An aryl group that may have a substituent, an alkoxy group that may have a substituent, an aryloxy group that may have a substituent, an alkylamino group that may have a substituent, and a substituent Arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, a substituent may be mentioned. An alkyl group that may have an aryl group that may have a substituent is preferable because of high radical reactivity.

Examples of the substituent that can be introduced include the same substituents as those described in formula (i).
Z represents an oxygen atom, a sulfur atom, —N (R ¹³ ) — or a phenylene group which may have a substituent. Examples of R ¹³ include an alkyl group which may have a substituent. Among them, a methyl group, an ethyl group, and an isopropyl group are preferable because of high radical reactivity.

  As the structure of these crosslinkable groups, the general formula (i) is particularly preferable among the general formulas (i) to (iii).

  The specific polymer compound (A) having crosslinkability has, for example, a free radical (a polymerization initiation radical or a growth radical in the polymerization process of the polymerizable compound) added to the crosslinkable functional group, and is directly or polymerizable between polymers. Addition polymerization is performed through the polymerization chain of the compound, and a crosslink is formed between the polymer molecules to be cured. Alternatively, atoms in the polymer (for example, hydrogen atoms on carbon atoms adjacent to the crosslinkable functional group) are extracted by free radicals to form polymer radicals that are bonded to each other, thereby causing crosslinking between polymer molecules. Forms and cures.

  Examples of the repeating unit (a1) having a crosslinkable group in the side chain include (meth) acrylic polymers, styryl polymers, polyurethane resins, polyvinyl alcohol resins, polyvinyl formal resins, polyamide resins, polyester resins, and epoxy resins. Is mentioned. In particular, (meth) acrylic polymers and styryl polymers are preferable, and (meth) acrylic polymers are more preferable. As the repeating unit (a1) having a crosslinkable group in the side chain, a repeating unit represented by the following general formula (A1) is preferable.

(In General Formula (A1), R ^{a to} R ^c each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom. L represents a single bond or a divalent linking group. a1) represents a state in which any of the structures represented by the general formulas (i) to (iii) is bonded directly or via a divalent linking group.
R ^{a to} R ^c are each preferably a hydrogen atom or a methyl group. R ^a and R ^b are more preferably a hydrogen atom.
The bivalent substituent as L is synonymous with Y < ³ > in general formula (a3-1), and its preferable range is also synonymous.

  In the specific polymer compound of the present invention, the ratio of the repeating unit (a1) having any one of the structures represented by the general formulas (i) to (iii) is the total repeating unit from the viewpoint of stain resistance and developability. The range is preferably 1 to 99% by weight, more preferably 10 to 80% by weight, and still more preferably 10 to 70% by weight.

Specific examples of the repeating unit having a crosslinkable group represented by (a1) include the following structures.

Other repeating units:
Moreover, the (A) copolymer used by this invention may contain other repeating units (henceforth other repeating units) other than the above-mentioned repeating unit as a copolymer component. Examples of other repeating units that may be contained as such repeating units include repeating units derived from various known monomers.
Preferred examples are derived from known monomers such as acrylic esters, methacrylic esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid, acrylonitrile, maleic anhydride, maleic imide, etc. And repeating units. By introducing the other repeating units into the copolymer (A), various physical properties of the layer such as film-forming property, film strength, hydrophilicity, hydrophobicity, solubility, reactivity, and stability are appropriately improved or controlled. can do.
Among them, monomers selected from acrylic acid esters, methacrylic acid esters, N, N-2 substituted acrylamides, N, N-2 substituted methacrylamides, styrenes, acrylonitriles, methacrylonitriles and the like can be mentioned. .

  Specifically, for example, acrylic esters such as alkyl acrylate (the alkyl group preferably has 1 to 20 carbon atoms) (specifically, for example, methyl acrylate, ethyl acrylate, acrylic Propyl acrylate, butyl acrylate, amyl acrylate, ethyl hexyl acrylate, octyl acrylate, tert-octyl acrylate, chloroethyl acrylate, 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane monoacrylate , Pentaerythritol monoacrylate, glycidyl acrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, etc.), aryl acrylate (for example, Methacrylic acid esters (e.g., methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate, Cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate , Furfuryl methacrylate, tetrahydrofur Silyl methacrylate), aryl methacrylate (for example, phenyl methacrylate, cresyl methacrylate, naphthyl methacrylate, etc.), styrene such as styrene, alkyl styrene (for example, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, isopropyl styrene, Butyl styrene, hexyl styrene, cyclohexyl styrene, decyl styrene, benzyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, etc.), alkoxy styrene (eg, methoxy styrene, 4-methoxy-3-methyl styrene, Dimethoxystyrene), halogen-containing styrene (eg, chlorostyrene, dichlorostyrene, trimethyl) Low styrene, tetrachlorostyrene, pentachlorostyrene, prom styrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, 4-fluoro-3-trifluoromethylstyrene, etc. ), Acrylonitrile, methacrylonitrile, methacrylic acid, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid and the like.

  In the copolymer (A), the proportion of the other repeating units is preferably 0 to 60 mol%, more preferably 0 to 40 mol%, and still more preferably 0 to 30%.

<< Copolymer of the Present Invention >>
Among the copolymers (A) that can be used for the lithographic printing plate precursor according to the present invention, the copolymer according to the present invention is a polymer compound having the following characteristic structure.

(1) A copolymer comprising the repeating unit represented by the general formula (A2) and the repeating unit represented by the general formula (A3).
(2) The copolymer according to (1), further comprising a repeating unit represented by the general formula (A1).
(3) The copolymer according to (1) or (2), wherein (a2) in the general formula (A2) is a structure represented by the general formula (a2-1) or (a2-2).
(4) The copolymer according to any one of (1) to (3), wherein G in the general formula (A3) is a structure represented by the general formula (a3-1) or (a3-2).
(4) The copolymer according to any one of (1) to (3), wherein G in the general formula (A3) is a structure represented by the general formula (a3-1).
(5) The copolymer in which the content of the repeating unit other than the general formulas (A2), (A3), and (A1) in the above (1) to (4) is 20% by weight.
(6) The copolymer according to (1) to (4), wherein the content of repeating units other than the general formulas (A2), (A3), and (A1) is 5% by weight or less.

(Weight average molecular weight)
The weight average molecular weight (Mw) of the copolymer (A) can be arbitrarily set depending on the performance design of the lithographic printing plate precursor. From the viewpoint of printing durability and stain resistance, the weight average molecular weight is 5,000 or more, preferably 5,000 to 1,000,000, more preferably 5,000 to 500,000, Most preferably, it is from 000 to 300,000.

Although the specific example of the said copolymer (A) is shown with the weight average molecular weight below, this invention is not limited to these. In addition, the composition ratio of the polymer structure represents a mass percentage.

<(B) Specific low molecular weight compound>
The specific low molecular weight compound of the present invention can be preferably used as long as it is a compound having a weight average molecular weight of less than 5000 and having a zwitterionic group in the molecule. A compound having an isomer that forms a zwitterion can also be used. Specific examples include carbobetaines, sulfobetaines, phosphobetaines, amino acids, N-monomethyl amino acids, N, N-dimethyl amino acids, N, N, N-trimethyl amino acids, sulfamic acid and the like.

As the zwitterionic compound, compounds represented by the following general formulas (b1-1) to (b1-8) are preferable, and (b1-1), (b1-2), (b1-5), (b1- 6) is particularly preferred.
(In the general formulas (b1-1) to (b1-8), R may have a hydrogen atom or a substituent, may be saturated or unsaturated, and may be linear, cyclic or branched. 15 represents an alkyl group, L represents a divalent linking group, Q represents an n-valent linking group, n represents an integer of 2 or more, A ⁻ represents a structure having an anion, E ⁺ represents a cation Represents a structure having

  R is preferably an alkyl group having 1 to 15 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and particularly preferably an alkyl group having 1 to 5 carbon atoms.

  Q is an n-valent linking group and binds to n parenthesized groups. As the linking group represented by Q, —CO—, —O—, —NH—, a tertiary amino group as a trivalent linking group, a divalent or higher aliphatic group, a divalent or higher aromatic group, and It is preferable that it is a coupling group which consists of those combinations.

L represents a linking group, preferably a —CO—, —O—, —NH—, a divalent aliphatic group, a divalent aromatic group, or a combination thereof, preferably described later. Including the number of carbon atoms of the substituent that may have, the number of carbon atoms is 30 or less. Specific examples thereof include an alkylene group (preferably having 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms) and an arylene group such as phenylene and xylylene (preferably having 5 to 15 carbon atoms, more preferably having a carbon number). 6 to 10). Among these, from the viewpoint of stain resistance, L ³¹ is preferably a linear alkylene group having 3 to 5 carbon atoms, more preferably a linear alkylene group having 4 or 5 carbon atoms, and most preferably a linear alkylene group having 4 carbon atoms. preferable.
A ^- preferably represents a carboxylate, sulfonate, phosphate, phosphonate or phosphinate.
Specific examples include the following anions.

From the standpoint of stain resistance, A ^- and most preferably is sulfonate.

  In the present invention, a compound represented by any one of the general formulas (b1-1), (b1-2), (b1-5) and (b1-6) is more preferable.

  The addition amount of the specific low molecular weight compound is preferably 1 to 50% by weight, more preferably 1 to 40% by weight, and particularly preferably 1 to 25% by weight with respect to the weight of the specific high molecular compound because of the influence on the coating property. .

  The molecular weight of the specific low molecular compound (weight average molecular weight when there is a molecular weight distribution) is less than 5000, more preferably less than 4000, more preferably less than 3000 from the viewpoint of suppressing aggregation of the specific low molecular compound itself. Is more preferable, and it is especially preferable that it is less than 1500. The lower limit is not particularly defined, but can be set to 100 or more, for example.

Specific examples of the specific low molecular weight compound include the following structures.

<Method for forming intermediate layer>
The intermediate layer is formed by applying water on a support and drying a solution prepared by dissolving the above compound in water, an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof, or water, methanol, ethanol, methyl ethyl ketone. The above compound can be adsorbed by immersing the support in a solution obtained by dissolving the above compound in an organic solvent such as the above or a mixed solvent thereof, and then washed and dried with water or the like. In the former method, a solution of the above compound having a concentration of 0.005 to 10% by mass can be applied by various methods.
For example, any method such as bar coater coating, spin coating, spray coating, or curtain coating may be used. In the latter method, the concentration of the solution is 0.01 to 20% by mass, preferably 0.05 to 5% by mass, the immersion temperature is 20 to 90 ° C., preferably 25 to 50 ° C., and the immersion time. Is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute.
The coating amount of the intermediate layer (solid content) is preferably from 0.1-100 mg / m ^2, and more preferably 1 to 30 mg / m ^2.

<Photosensitive layer>
The photosensitive layer in the invention preferably contains (C) a polymerization initiator, (D) a polymerizable compound, (E) a binder, and (F) a dye.

(C) Polymerization initiator The photosensitive layer of the invention preferably contains a polymerization initiator (hereinafter also referred to as an initiator compound). In the present invention, a radical polymerization initiator is preferably used.

  As the initiator compound, those known to those skilled in the art can be used without limitation, and specifically include, for example, trihalomethyl compounds, carbonyl compounds, organic peroxides, azo compounds, azide compounds, metallocene compounds, hexaarynes. Examples include rubiimidazole compounds, organic boron compounds, disulfone compounds, oxime ester compounds, onium salts, and iron arene complexes. Of these, at least one selected from the group consisting of hexaarylbiimidazole compounds, onium salts, trihalomethyl compounds, and metallocene compounds is preferable, and hexaarylbiimidazole compounds and onium salts are particularly preferable. Two or more polymerization initiators may be used in combination as appropriate.

  Examples of the hexaarylbiimidazole compound include lophine dimers described in European Patent No. 24629, European Patent No. 107792, US Pat. No. 4,410,621, such as 2,2′-bis (o-chlorophenyl) -4,4. ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-bromophenyl) -4,4', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o, p -Dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra (m-methoxyphenyl) biimidazole 2,2'-bis (o, o'-dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-nitrophenyl) -4 4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-methylphenyl) -4,4', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o- Trifluoromethylphenyl) -4,4 ', 5,5'-tetraphenylbiimidazole and the like. The hexaarylbiimidazole compound is particularly preferably used in combination with a sensitizing dye having a maximum absorption in a wavelength region of 300 to 450 nm.

  Examples of the onium salt include S.I. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Bal et al, Polymer, 21, 423 (1980), diazonium salts described in JP-A-5-158230, ammonium described in US Pat. No. 4,069,055, JP-A-4-365049, and the like. Salt, phosphonium salts described in U.S. Pat. Nos. 4,069,055 and 4,069,056, EP 104,143, U.S. Patent Application Publication No. 2008/0311520 JP-A-2-150848, JP-A-2008-195018, or J.P. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), iodonium salts, European Patent Nos. 370,693, 233,567, 297,443, 297,442, US Patent 4,933,377, 4,760,013, 4,734,444, 2,833,827, German Patents 2,904,626, 3,604,580, Sulfonium salts described in each specification of JP-A-3,604,581; V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), a selenonium salt described in C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), azinium salts described in JP-A-2008-195018, and the like.

  Of these, more preferred are iodonium salts, sulfonium salts, and azinium salts. Although the specific example of these compounds is shown below, it is not limited to this.

  An example of the iodonium salt is a diphenyl iodonium salt, particularly a diphenyl iodonium salt substituted with an electron donating group such as an alkyl group or an alkoxyl group, and more preferably an asymmetric diphenyl iodonium salt. Specific examples include diphenyliodonium = hexafluorophosphate, 4-methoxyphenyl-4- (2-methylpropyl) phenyliodonium = hexafluorophosphate, 4- (2-methylpropyl) phenyl-p-tolyliodonium = hexa. Fluorophosphate, 4-hexyloxyphenyl-2,4,6-trimethoxyphenyliodonium = hexafluorophosphate, 4-hexyloxyphenyl-2,4-diethoxyphenyliodonium = tetrafluoroborate, 4-octyloxy Phenyl-2,4,6-trimethoxyphenyliodonium = 1-perfluorobutanesulfonate, 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium = hexafluorophosphate, bis ( -t- butylphenyl) iodonium tetraphenylborate and the like.

  Examples of the sulfonium salts include triphenylsulfonium = hexafluorophosphate, triphenylsulfonium = benzoylformate, bis (4-chlorophenyl) phenylsulfonium = benzoylformate, bis (4-chlorophenyl) -4-methylphenylsulfonium = Tetrafluoroborate, tris (4-chlorophenyl) sulfonium = 3,5-bis (methoxycarbonyl) benzenesulfonate, tris (4-chlorophenyl) sulfonium = hexafluorophosphate.

Examples of the azinium salts include 1-cyclohexylmethyloxypyridinium = hexafluorophosphate, 1-cyclohexyloxy-4-phenylpyridinium = hexafluorophosphate, 1-ethoxy-4-phenylpyridinium = hexafluorophosphate, 1 -(2-ethylhexyloxy) -4-phenylpyridinium = hexafluorophosphate, 4-chloro-1-cyclohexylmethyloxypyridinium = hexafluorophosphate, 1-ethoxy-4-cyanopyridinium = hexafluorophosphate, 3, 4-dichloro-1- (2-ethylhexyloxy) pyridinium = hexafluorophosphate, 1-benzyloxy-4-phenylpyridinium = hexafluorophosphate, 1-phenethyl Oxy-4-phenylpyridinium = hexafluorophosphate, 1- (2-ethylhexyloxy) -4-phenylpyridinium = p-toluenesulfonate, 1- (2-ethylhexyloxy) -4-phenylpyridinium = perfluorobutanesulfonate 1- (2-ethylhexyloxy) -4-phenylpyridinium bromide, 1- (2-ethylhexyloxy) -4-phenylpyridinium tetrafluoroborate.
The onium salt is particularly preferably used in combination with an infrared absorber having a maximum absorption in a wavelength range of 750 to 1400 nm.

  In addition, polymerization initiators described in paragraph numbers [0071] to [0129] of JP-A-2007-206217 can also be preferably used.

The polymerization initiator is suitably used alone or in combination of two or more.
The content of the polymerization initiator in the photosensitive layer is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, and still more preferably 1.0 to 0.1% by mass relative to the total solid content of the photosensitive layer. 10% by mass.

(D) Polymerizable Compound The polymerizable compound used in the photosensitive layer is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and has at least one terminal ethylenically unsaturated bond, preferably 2 It is selected from compounds having at least one. These have chemical forms such as monomers, prepolymers, ie dimers, trimers and oligomers, or mixtures thereof. Examples of monomers include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof, preferably unsaturated carboxylic acids. Esters of an acid and a polyhydric alcohol compound and amides of an unsaturated carboxylic acid and a polyamine compound are used. Further, addition reaction products of unsaturated carboxylic acid esters or amides having a nucleophilic substituent such as hydroxyl group, amino group, mercapto group and the like with monofunctional or polyfunctional isocyanates or epoxy, and monofunctional or polyfunctional A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. Further, an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group and an addition reaction product of a monofunctional or polyfunctional alcohol, amine or thiol, a halogen group, A substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a tosyloxy group and a monofunctional or polyfunctional alcohol, amine or thiol is also suitable. It is also possible to use a compound group in which the unsaturated carboxylic acid is replaced with unsaturated phosphonic acid, styrene, vinyl ether or the like. These are disclosed in JP-T-2006-508380, JP-A-2002-287344, JP-A-2008-256850, JP-A-2001-342222, JP-A-9-179296, JP-A-9-179297. JP-A-9-179298, JP-A-2004-294935, JP-A-2006-243493, JP-A-2002-275129, JP-A-2003-64130, JP-A-2003-280187, It is described in Japanese Laid-Open Patent Publication No. 10-333321.

  Specific examples of the ester monomer of the polyhydric alcohol compound and the unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, 1,3-butanediol diacrylate, tetramethylene glycol diacrylate, and propylene glycol diacrylate. , Trimethylolpropane triacrylate, hexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol tetraacrylate, sorbitol triacrylate, isocyanuric acid ethylene oxide (EO) modified triacrylate, polyester acrylate oligomer, and the like. Methacrylic acid esters include tetramethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, pentaerythritol trimethacrylate, bis [p- (3-methacryloxy-2-hydroxypropoxy) phenyl ] Dimethylmethane, bis- [p- (methacryloxyethoxy) phenyl] dimethylmethane, and the like. Specific examples of amide monomers of polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis-methacrylic. Examples include amide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, and xylylene bismethacrylamide.

Also suitable are urethane-based addition polymerizable compounds produced using an addition reaction of isocyanate and hydroxyl groups. By employing such a compound, the strength of the exposed photosensitive layer is increased while maintaining high developability of the unexposed photosensitive layer, and a printing plate having both developability and printing durability can be obtained.
Specific examples of the compound having such a urethane structure include, for example, a polyisocyanate compound having two or more isocyanate groups per molecule described in JP-B-48-41708, and the following general formula (P) And vinyl urethane compounds containing two or more polymerizable vinyl groups in one molecule to which a vinyl monomer containing a hydroxyl group represented by the formula (1) is added.

^{_{CH 2 = C (R 104)}} COOCH 2 CH (R 105) OH (P)
(However, R ¹⁰⁴ and R ¹⁰⁵ represent H or CH _3. )

  Also, urethanes described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-A-2003-344997, and JP-A-2006-65210. Acrylates, JP-B 58-49860, JP-B 56-17654, JP-B 62-39417, JP-B 62-39418, JP-A 2000-250211, JP-A 2007-94138 Urethane compounds having an ethylene oxide skeleton described in the publication, US Pat. No. 7,153,632, JP-T 8-505958, JP-A 2007-293221, and JP-A 2007-293223. Urethane compounds having the described hydrophilic group are also suitable.

  Among the above, in the case of a lithographic printing plate precursor to which on-press development is applied, tris (acryloyloxyethyl) isocyanate is excellent in that it has a good balance of hydrophilicity involved in on-press developability and polymerization ability involved in printing durability. Isocyanuric acid ethylene oxide-modified acrylates such as nurate and bis (acryloyloxyethyl) hydroxyethyl isocyanurate are particularly preferred.

  Details of the method of use such as the structure of the polymerizable compound (D), single use or combination, addition amount, etc. can be arbitrarily set in accordance with the performance design of the final lithographic printing plate precursor. The polymerizable compound (D) is preferably used in the range of 5 to 75% by mass, more preferably 25 to 70% by mass, and particularly preferably 30 to 60% by mass with respect to the total solid content of the photosensitive layer. The

(E) Binder The (E) binder contained in the photosensitive layer of the lithographic printing plate precursor according to the invention is one that can carry the photosensitive layer component on a support and can be removed by a developer. . As the (E) binder, (meth) acrylic resin, polyurethane resin, polyvinyl alcohol resin, polyvinyl butyral resin, polyvinyl formal resin, polyamide resin, polyester resin, epoxy resin and the like are used. In particular, (meth) acrylic resin, polyurethane resin, and polyvinyl butyral resin are preferably used, and (meth) acrylic resin, polyurethane resin, and polyvinyl butyral resin are more preferable. By using (meth) acrylic resin, polyurethane resin or polyvinyl butyral resin, the exposed portion photosensitive layer becomes a film resistant to abrasion and peeling, and a printing plate with high printing durability is obtained.

In the present invention, “(meth) acrylic polymer” means (meth) acrylic acid, (meth) acrylic acid ester (alkyl ester, aryl ester, allyl ester, etc.), (meth) acrylamide and (meth) acrylamide derivatives. It refers to a copolymer having a (meth) acrylic acid derivative such as “Polyurethane resin” refers to a polymer produced by a condensation reaction of a compound having two or more isocyanate groups and a compound having two or more hydroxyl groups. “Polyvinyl butyral resin” refers to a polymer synthesized by reacting polyvinyl alcohol and butyraldehyde obtained by saponifying a part or all of polyvinyl acetate under an acidic condition (acetalization reaction). A polymer having an acid group or the like introduced by a method of reacting a compound having a remaining hydroxy group and an acid group or the like is also included.
A suitable example of the (meth) acrylic polymer is a copolymer having a repeating unit containing an acid group. Examples of the acid group include a carboxylic acid group, a sulfonic acid group, a phosphonic acid group, a phosphoric acid group, and a sulfonamide group, and a carboxylic acid group is particularly preferable. As the repeating unit containing an acid group, a repeating unit derived from (meth) acrylic acid or one represented by the following general formula (I) is preferably used.

In the general formula (I), R ²¹¹ represents a hydrogen atom or a methyl group, and R ²¹² represents a single bond or an n ₂₁₁ +1 valent linking group. A ²¹¹ represents an oxygen atom or —NR ²¹³ —, and R ²¹³ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. n ₂₁₁ represents an integer of 1 to 5.

The linking group represented by R ²¹² in the general formula (I) is composed of a hydrogen atom, a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom, and the number of atoms is preferably 1 to 80. It is. Specifically, an alkylene group, a substituted alkylene group, an arylene group, a substituted arylene group, and the like can be mentioned. These divalent groups are linked in multiples by any of an amide bond, an ether bond, a urethane bond, a urea bond, and an ester bond. You may have the structure made. R ²¹² has a structure in which a single bond, an alkylene group, a substituted alkylene group, and an alkylene group and / or a substituted alkylene group are connected in plural by an amide bond, an ether bond, a urethane bond, a urea bond, or an ester bond. A single bond, an alkylene group having 1 to 5 carbon atoms, a substituted alkylene group having 1 to 5 carbon atoms and an alkylene group having 1 to 5 carbon atoms and / or a substituted alkylene group having 1 to 5 carbon atoms is an amide bond, an ether More preferably, it is a structure in which a plurality of bonds, urethane bonds, urea bonds, or ester bonds are connected, and a single bond, an alkylene group having 1 to 3 carbon atoms, a substituted alkylene group having 1 to 3 carbon atoms, and carbon. An alkylene group of 1 to 3 and / or a substituted alkylene group of 1 to 3 carbon atoms is an amide bond, ether bond, urethane bond, urea bond, It is particularly preferable that the structure is a structure in which a plurality of ter bonds are connected.
Examples of the substituent that the linking group represented by R ²¹² may have include a monovalent nonmetallic atomic group excluding a hydrogen atom, and a halogen atom (—F, —Br, —Cl, -I), hydroxyl group, cyano group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkylcarbonyl group, arylcarbonyl group, carboxyl group and its conjugate base group, alkoxycarbonyl group, aryloxycarbonyl group, A carbamoyl group, an aryl group, an alkenyl group, an alkynyl group and the like can be mentioned.

^R213 is preferably a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, and particularly preferably a hydrogen atom or a methyl group.
_n211 is preferably 1 to 3, more preferably 1 or 2, and particularly preferably 1.

The proportion (mol%) of the polymerization component having a carboxylic acid group in the total polymerization components of the (meth) acrylic polymer is preferably 1 to 70% from the viewpoint of developability. In consideration of compatibility between developability and printing durability, 1 to 50% is more preferable, and 1 to 30% is particularly preferable.
The (meth) acrylic polymer used in the present invention preferably further has a crosslinkable group. Here, the crosslinkable group is a group that crosslinks the (E) binder in the course of a radical polymerization reaction that occurs in the photosensitive layer when the lithographic printing plate precursor is exposed. Although it will not specifically limit if it is a group of such a function, For example, an ethylenically unsaturated bond group, an amino group, an epoxy group etc. are mentioned as a functional group which can be addition-polymerized. Moreover, the functional group which can become a radical by light irradiation may be sufficient, and as such a crosslinkable group, a thiol group, a halogen group, etc. are mentioned, for example. Of these, an ethylenically unsaturated bond group is preferable. As the ethylenically unsaturated bond group, a styryl group, a (meth) acryloyl group, and an allyl group are preferable.

  In the binder (E), for example, a free radical (a polymerization initiation radical or a growth radical in the polymerization process of a polymerizable compound) is added to the crosslinkable functional group, and the polymer is directly or via a polymerization chain of the polymerizable compound. Then, addition polymerization is performed, and a crosslink is formed between the polymer molecules to be cured. Alternatively, atoms in the polymer (eg, hydrogen atoms on carbon atoms adjacent to the functional bridging group) are abstracted by free radicals to form polymer radicals that are bonded to each other so that crosslinking between the polymer molecules occurs. Forms and cures.

  The content of the crosslinkable group in the (meth) acrylic polymer (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.01 to 10 per 1 g of the (E) binder. 0 mmol, more preferably 0.05 to 9.0 mmol, particularly preferably 0.1 to 8.0 mmol.

  The (meth) acrylic polymer used in the present invention includes, in addition to the above-described polymer unit having an acid group and polymer unit having a crosslinkable group, a polymer unit of (meth) acrylic acid alkyl or aralkyl ester, (meth) acrylamide. Alternatively, it may have a polymer unit of a derivative thereof, a polymer unit of α-hydroxymethyl acrylate, and a polymer unit of a styrene derivative. The alkyl group of the (meth) acrylic acid alkyl ester is preferably an alkyl group having 1 to 5 carbon atoms and an alkyl group having the aforementioned substituent having 2 to 8 carbon atoms, and a methyl group is more preferable. Examples of the (meth) acrylic acid aralkyl ester include benzyl (meth) acrylate. Examples of (meth) acrylamide derivatives include N-isopropylacrylamide, N-phenylmethacrylamide, N- (4-methoxycarbonylphenyl) methacrylamide, N, N-dimethylacrylamide, morpholinoacrylamide and the like. Examples of the α-hydroxymethyl acrylate include ethyl α-hydroxymethyl acrylate and cyclohexyl α-hydroxymethyl acrylate. Examples of styrene derivatives include styrene and 4-tertbutylstyrene.

  In the case of a lithographic printing plate precursor to which on-press development is applied, the (E) binder preferably has a hydrophilic group. The hydrophilic group contributes to imparting on-press developability to the photosensitive layer. In particular, the coexistence of the crosslinkable group and the hydrophilic group makes it possible to achieve both printing durability and on-press developability.

  Examples of the hydrophilic group that the (E) binder may have include a hydroxy group, a carboxyl group, an alkylene oxide structure, an amino group, an ammonium group, an amide group, a sulfo group, and a phosphate group. Of these, an alkylene oxide structure having 1 to 9 alkylene oxide units having 2 or 3 carbon atoms is preferred. For imparting a hydrophilic group to the binder, for example, copolymerization of a monomer having a hydrophilic group is performed.

  As preferable examples of the polyurethane resin, paragraph numbers [0099] to [0210] of JP-A No. 2007-187836, paragraph numbers [0019] to [0100] of JP-A No. 2008-276155, JP-A No. 2005-250438. And the polyurethane resins described in JP-A-2005-250158, paragraphs [0021] to [0083].

As a suitable example of the said polyvinyl butyral resin, the polyvinyl butyral resin as described in paragraph number [0006]-[0013] of Unexamined-Japanese-Patent No. 2001-75279 can be mentioned.
A part of the acid group in the (E) binder may be neutralized with a basic compound. Examples of basic compounds include compounds containing basic nitrogen, alkali metal hydroxides, and quaternary ammonium salts of alkali metals.

The (E) binder preferably has a weight average molecular weight of 5000 or more, more preferably 10,000 to 300,000, a number average molecular weight of 1,000 or more, and more preferably 2000 to 250,000. The polydispersity (weight average molecular weight / number average molecular weight) is preferably 1.1 to 10.
The (E) binder may be used alone or in combination of two or more.
The content of the binder (E) is preferably 5 to 75% by mass, more preferably 10 to 70% by mass, based on the total solid content of the photosensitive layer, from the viewpoint of good image area strength and image formability. Preferably, 10 to 60% by mass is more preferable.
The total content of the polymerizable compound (D) and the binder (E) is preferably 90% by mass or less based on the total solid content of the photosensitive layer. If it exceeds 90% by mass, the sensitivity and developability may be lowered. More preferably, it is 35-80 mass%.

(F) Dye The photosensitive layer preferably contains (F) a dye. More preferably, the dye is a sensitizing dye.
The sensitizing dye used in the photosensitive layer of the lithographic printing plate precursor according to the invention absorbs light at the time of image exposure and becomes excited, and supplies energy to the polymerization initiator by electron transfer, energy transfer, or heat generation. Any polymer that can improve the polymerization initiation function can be used without particular limitation. In particular, a sensitizing dye having a maximum absorption in a wavelength range of 300 to 450 nm or 750 to 1400 nm is preferably used.

  Examples of the sensitizing dye having maximum absorption in the wavelength range of 350 to 450 nm include merocyanines, benzopyrans, coumarins, aromatic ketones, anthracenes, styryls, oxazoles and the like.

  Among the sensitizing dyes having an absorption maximum in the wavelength range of 350 to 450 nm, a dye more preferable from the viewpoint of high sensitivity is a dye represented by the following general formula (IX).

In General Formula (IX), A ²²¹ represents an aryl group or a heteroaryl group which may have a substituent, and X ²²¹ represents an oxygen atom, a sulfur atom, or ═N (R ²²³ ). R ²²¹ , R ²²² and R ²²³ each independently represent a monovalent non-metallic atomic group, and A ²²¹ and R ²²¹ or R ²²² and R ²²³ are bonded to each other to form an aliphatic or aromatic group. The ring may be formed.

General formula (IX) will be described in more detail. The monovalent nonmetallic atomic group represented by R ²²¹ , R ²²² or R ²²³ is preferably a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group. Represents a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a hydroxyl group, or a halogen atom.

The aryl group and heteroaryl group which may have a substituent represented by A ²²¹ are the substituted or unsubstituted aryl group and substituted or unsubstituted heteroaryl group respectively represented by R ²²¹ , R ²²² and R ²²³ It is the same.

  Specific examples of such a sensitizing dye include paragraph numbers [0047] to [0053] of JP-A No. 2007-58170, paragraph numbers [0036] to [0037] of JP-A No. 2007-93866, and JP-A No. 2007-. The compounds described in paragraph Nos. [0042] to [0047] of No. 72816 are preferably used.

  JP-A-2006-189604, JP-A-2007-171406, JP-A-2007-206216, JP-A-2007-206217, JP-A-2007-225701, JP-A-2007-225702, JP-A-2007-316582 Sensitizing dyes described in JP-A-2007-328243 can also be preferably used.

  Then, it describes about the sensitizing dye (henceforth an infrared absorber) which has maximum absorption in the said 750-1400 nm wavelength range. As the infrared absorber, a dye or a pigment is preferably used.

As the dye, commercially available dyes and known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes Is mentioned.
Particularly preferred among these dyes are cyanine dyes, squarylium dyes, pyrylium salts, nickel thiolate complexes, and indolenine cyanine dyes. Further, cyanine dyes and indolenine cyanine dyes are preferred, and particularly preferred examples include cyanine dyes represented by the following general formula (a).

In the general formula (a), X ¹³¹ represents a hydrogen atom, a halogen atom, -NPh ₂ , -X ¹³² -L ¹³¹ or a group shown below. Ph represents a phenyl group.

Here, X ¹³² represents an oxygen atom, a nitrogen atom or a sulfur atom, L ¹³¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an aryl group having a hetero atom (N, S, O, halogen atom, Se), The C1-C12 hydrocarbon group containing a hetero atom is shown. X _a ^- is Z _a to be described later ^- which is synonymous with. R ¹⁴¹ represents a hydrogen atom or a substituent selected from an alkyl group, an aryl group, a substituted or unsubstituted amino group, and a halogen atom.

R ¹³¹ and R ¹³² each independently represent a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the photosensitive layer coating solution, R ¹³¹ and R ¹³² are preferably hydrocarbon groups having 2 or more carbon atoms. R ¹³¹ and R ¹³² may be connected to each other to form a ring, and when the ring is formed, it is particularly preferable to form a 5-membered ring or a 6-membered ring.

Ar ¹³¹ and Ar ¹³² may be the same or different and each represents an aryl group which may have a substituent. Preferred aryl groups include a benzene ring group and a naphthalene ring group. Moreover, as a preferable substituent, a C12 or less hydrocarbon group, a halogen atom, and a C12 or less alkoxy group are mentioned. Y ¹³¹ and Y ¹³² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ¹³³ and R ¹³⁴ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms, which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxyl groups, and sulfo groups. R ¹³⁵ , R ¹³⁶ , R ¹³⁷ and R ¹³⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. In view of easy availability of the raw material, a hydrogen atom is preferred. Z _a ^- represents a counter anion. However, when the cyanine dye represented by formula (a) has an anionic substituent in the structure thereof, Z _a is does not require charge neutralization ^- is not necessary. Preferred Z _a ⁻ is a halide ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, in view of the storage stability of the photosensitive layer coating solution. Hexafluorophosphate ion and aryl sulfonate ion.

  Specific examples of the cyanine dye represented by the general formula (a) include compounds described in JP-A No. 2001-133969, paragraph numbers [0017] to [0019], and JP-A No. 2002-023360, paragraph number [0016]. To [0021], compounds described in paragraph numbers [0012] to [0037] of JP-A No. 2002-040638, preferably paragraph numbers [0034] to [0041] of JP-A No. 2002-278057, JP-A No. 2008-195018. And the compounds described in paragraphs [0035] to [0043] of JP-A-2007-90850 are particularly preferable.

  In addition, compounds described in paragraph numbers [0008] to [0009] of JP-A No. 5-5005 and paragraph numbers [0022] to [0025] of JP-A No. 2001-222101 can also be preferably used.

  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, the compounds described in JP-A-2008-195018, paragraphs [0072] to [0076] are preferable.

  The content of the (F) dye is preferably 0.05 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and particularly preferably 0.2 to 100 parts by mass of the total solid content of the photosensitive layer. -10 parts by mass.

(G) Low molecular weight hydrophilic compound The photosensitive layer may contain a low molecular weight hydrophilic compound in order to improve the on-press developability without reducing the printing durability.
Examples of the low molecular weight hydrophilic compound include water-soluble organic compounds such as glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and ether or ester derivatives thereof, glycerin. , Polyols such as pentaerythritol and tris (2-hydroxyethyl) isocyanurate, organic amines such as triethanolamine, diethanolamine and monoethanolamine and salts thereof, and organic such as alkylsulfonic acid, toluenesulfonic acid and benzenesulfonic acid Sulfonic acids and salts thereof, organic sulfamic acids such as alkylsulfamic acid and salts thereof, organic sulfuric acids such as alkylsulfuric acid and alkylethersulfuric acid and salts thereof, phenylphosphine Organic phosphonic acids and their salts such as phosphate, tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid, organic carboxylic acids and salts thereof such as amino acids, betaines, and the like.

  Among these, in the present invention, it is preferable to contain at least one selected from polyols, organic sulfates, organic sulfonates, and betaines.

  Specific examples of the organic sulfonate include alkyl sulfonic acids such as sodium n-butyl sulfonate, sodium n-hexyl sulfonate, sodium 2-ethylhexyl sulfonate, sodium cyclohexyl sulfonate, and sodium n-octyl sulfonate. Salt; sodium 5,8,11-trioxapentadecane-1-sulfonate, sodium 5,8,11-trioxaheptadecane-1-sulfonate, 13-ethyl-5,8,11-trioxaheptadecane- Alkyl sulfonates containing ethylene oxide chains such as sodium 1-sulfonate, 5,8,11,14-tetraoxatetradecosan-1-sodium sulfonate; sodium benzenesulfonate, sodium p-toluenesulfonate, p- Hydroxybenzenes Sodium fonate, sodium p-styrenesulfonate, dimethyl-5-sulfonate sodium isophthalate, sodium 1-naphthylsulfonate, sodium 4-hydroxynaphthylsulfonate, disodium 1,5-naphthalenedisulfonate, 1,3, Aryl sulfonates such as trisodium 6-naphthalene trisulfonate, paragraph numbers [0026] to [0031] of JP-A No. 2007-276454, paragraph numbers [0020] to [0047] of JP-A No. 2009-154525 And the like. The salt may be a potassium salt or a lithium salt.

  Examples of the organic sulfate include sulfates of alkyl, alkenyl, alkynyl, aryl or heterocyclic monoethers of polyethylene oxide. The ethylene oxide unit is preferably 1 to 4, and the salt is preferably a sodium salt, potassium salt or lithium salt. Specific examples thereof include compounds described in paragraph numbers [0034] to [0038] of JP-A-2007-276454.

  As said betaines, the compound whose carbon atom number of the hydrocarbon substituent to a nitrogen atom is 1-5 is preferable, As a specific example, a trimethylammonium acetate, a dimethylpropylammonium acetate, 3-hydroxy-4- Trimethylammoniobutylate, 4- (1-pyridinio) butyrate, 1-hydroxyethyl-1-imidazolioacetate, trimethylammonium methanesulfonate, dimethylpropylammonium methanesulfonate, 3-trimethylammonio-1-propanesulfonate , 3- (1-pyridinio) -1-propanesulfonate and the like.

  Since the low molecular weight hydrophilic compound has a small hydrophobic portion structure and almost no surface-active action, the dampening solution penetrates into the exposed portion of the photosensitive layer (image portion) and decreases the hydrophobicity and film strength of the image portion. The ink acceptability and printing durability of the photosensitive layer can be maintained well.

  The content of the low molecular weight hydrophilic compound in the photosensitive layer is preferably from 0.5 to 20 mass%, more preferably from 1 to 15 mass%, more preferably from 2 to 10 mass%, based on the total solid content of the photosensitive layer. Is more preferable. In this range, good on-press developability and printing durability can be obtained. A low molecular weight hydrophilic compound may be used independently and may be used in mixture of 2 or more types.

(H) Grease Sensitizer The photosensitive layer may contain a oil sensitizer such as a phosphonium compound, a nitrogen-containing low molecular weight compound, or an ammonium group-containing polymer in order to improve the inking property. In particular, when the protective layer contains an inorganic stratiform compound, the sensitizer functions as a surface coating agent for the inorganic stratiform compound, and prevents a decrease in the inking property during printing by the inorganic stratiform compound.

  Suitable phosphonium compounds include phosphonium compounds described in JP-A-2006-297907 and JP-A-2007-50660. Specific examples include tetrabutylphosphonium iodide, butyltriphenylphosphonium bromide, tetraphenylphosphonium bromide, 1,4-bis (triphenylphosphonio) butanedi (hexafluorophosphate), 1,7-bis (tri Phenylphosphonio) heptane sulfate, 1,9-bis (triphenylphosphonio) nonane = naphthalene-2,7-disulfonate, and the like.

  Examples of the nitrogen-containing low molecular weight compound include amine salts and quaternary ammonium salts. Also included are imidazolinium salts, benzoimidazolinium salts, pyridinium salts, and quinolinium salts. Of these, quaternary ammonium salts and pyridinium salts are preferred. Specific examples include tetramethylammonium = hexafluorophosphate, tetrabutylammonium = hexafluorophosphate, dodecyltrimethylammonium = p-toluenesulfonate, benzyltriethylammonium = hexafluorophosphate, benzyldimethyloctylammonium = hexafluorophosphate. Fert, benzyldimethyldodecyl ammonium = hexafluorophosphate, compounds described in JP-A No. 2008-284858, paragraph numbers [0021] to [0037], JP-A No. 2009-90645, paragraphs [0030] to [0057], etc. Is mentioned.

  The ammonium group-containing polymer may be any polymer as long as it has an ammonium group in its structure, but a polymer containing 5 to 80 mol% of a (meth) acrylate having an ammonium group in the side chain as a copolymerization component is preferable. . Specific examples include the polymers described in paragraph numbers [0089] to [0105] of JP-A-2009-208458.

  The ammonium salt-containing polymer preferably has a reduced specific viscosity (unit: ml / g) determined by the following measurement method in the range of 5 to 120, more preferably in the range of 10 to 110, 15 Those in the range of ~ 100 are particularly preferred. When the said reduced specific viscosity is converted into a weight average molecular weight, 10,000-150,000 are preferable, 17000-140000 are more preferable, 20000-130000 are especially preferable.

<< Measurement Method of Reduced Specific Viscosity >>
Weigh 3.33 g of 30% polymer solution (1 g as solid content) into a 20 ml volumetric flask and make up with N-methylpyrrolidone. This solution is allowed to stand for 30 minutes in a thermostatic bath at 30 ° C., put in an Ubbelohde reduced viscosity tube (viscosity constant = 0.010 cSt / s), and the time for flowing down at 30 ° C. is measured. The measurement is performed twice with the same sample, and the average value is calculated. Similarly, in the case of a blank (only N-methylpyrrolidone), the reduced specific viscosity (ml / g) is calculated from the following formula.

Specific examples of the ammonium group-containing polymer are shown below.
(1) 2- (Trimethylammonio) ethyl methacrylate = p-toluenesulfonate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 10/90 weight average molecular weight 45,000)
(2) 2- (Trimethylammonio) ethyl methacrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80 weight average molecular weight 60,000)
(3) 2- (Ethyldimethylammonio) ethyl methacrylate = p-toluenesulfonate / hexyl methacrylate copolymer (molar ratio 30/70 weight average molecular weight 45,000)
(4) 2- (Trimethylammonio) ethyl methacrylate = hexafluorophosphate / 2-ethylhexyl methacrylate copolymer (molar ratio 20/80 weight average molecular weight 60,000)
(5) 2- (Trimethylammonio) ethyl methacrylate = methyl sulfate / hexyl methacrylate copolymer (molar ratio 40/60 weight average molecular weight 7 million)
(6) 2- (butyldimethylammonio) ethyl methacrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 25/75 weight average molecular weight 650,000)
(7) 2- (Butyldimethylammonio) ethyl acrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80 weight average molecular weight 650,000)
(8) 2- (butyldimethylammonio) ethyl methacrylate = 13-ethyl-5,8,11-trioxa-1-heptadecanesulfonate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80 (Weight average molecular weight 75,000)
(9) 2- (butyldimethylammonio) ethyl methacrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate / 2-hydroxy-3-methacryloyloxypropyl methacrylate copolymer (molar ratio 15/80/5 (Weight average molecular weight 65,000)

  The content of the sensitizer is preferably 0.01 to 30.0 mass%, more preferably 0.1 to 15.0 mass%, and more preferably 1 to 5 mass% with respect to the total solid content of the photosensitive layer. Further preferred.

(I) Hydrophobized precursor The photosensitive layer may contain a hydrophobized precursor in order to improve on-press developability. The hydrophobized precursor means fine particles that can convert the photosensitive layer to hydrophobic when heat is applied. The fine particles are at least one selected from hydrophobic thermoplastic polymer fine particles, heat-reactive polymer fine particles, polymer fine particles having a polymerizable group, microcapsules enclosing a hydrophobic compound, and microgel (crosslinked polymer fine particles). It is preferable. Among these, polymer fine particles and microgels having a polymerizable group are preferable.

Examples of the hydrophobic thermoplastic polymer fine particles include Research Disclosure, No. 1, January 1992. 333003, JP-A-9-123387, JP-A-9-131850, JP-A-9-171249, JP-A-9-171250, and European Patent No. 931647, etc. A fine particle can be mentioned as a suitable thing.
Specific examples of polymers constituting such polymer fine particles include ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinyl carbazole, and polyalkylene structures. Mention may be made of homopolymers or copolymers of monomers such as acrylates or methacrylates or mixtures thereof. Among them, more preferable examples include a copolymer containing polystyrene, styrene and acrylonitrile, and polymethyl methacrylate.

  The average particle diameter of the hydrophobic thermoplastic polymer fine particles used in the present invention is preferably 0.01 to 2.0 μm.

  Examples of the heat-reactive polymer fine particles used in the present invention include polymer fine particles having a heat-reactive group, and these form a hydrophobized region by cross-linking by a heat reaction and a functional group change at that time.

  The thermoreactive group in the polymer fine particles having a thermoreactive group used in the present invention may be any functional group that performs any reaction as long as a chemical bond is formed, but is preferably a polymerizable group, Examples include ethylenically unsaturated groups that undergo radical polymerization reactions (eg, acryloyl groups, methacryloyl groups, vinyl groups, allyl groups, etc.), cationic polymerizable groups (eg, vinyl groups, vinyloxy groups, epoxy groups, oxetanyl groups, etc.) ), An isocyanato group that performs an addition reaction or a block thereof, an epoxy group, a vinyloxy group, and a functional group having an active hydrogen atom that is a reaction partner thereof (for example, an amino group, a hydroxy group, a carboxy group, etc.), and a condensation reaction Carboxy group and hydroxy or amino group as reaction partner, acid anhydride and reaction to perform ring-opening addition reaction An amino group or a hydroxyl group with whom may be mentioned as suitable.

  As the microcapsules used in the present invention, for example, as described in JP-A Nos. 2001-277740 and 2001-277742, all or part of the constituent components of the photosensitive layer are encapsulated in microcapsules. It is. The constituent components of the photosensitive layer can also be contained outside the microcapsules. Furthermore, it is preferable that the photosensitive layer containing the microcapsule includes a hydrophobic constituent component in the microcapsule and a hydrophilic constituent component outside the microcapsule.

  The microgel used in the present invention can contain a part of the constituent components of the photosensitive layer in at least one of the inside and the surface thereof. In particular, an embodiment in which a reactive microgel is formed by having a radical polymerizable group on the surface thereof is particularly preferable from the viewpoint of image forming sensitivity and printing durability.

  A known method can be applied to microencapsulate or microgel the constituent components of the photosensitive layer.

  The average particle size of the microcapsule or microgel is preferably 0.01 to 3.0 μm, more preferably 0.05 to 2.0 μm, and particularly preferably 0.10 to 1.0 μm. Within this range, good resolution and stability over time can be obtained.

  The content of the hydrophobizing precursor is preferably 5 to 90% by mass of the total solid content of the photosensitive layer.

(J) Other photosensitive layer components The photosensitive layer preferably contains a chain transfer agent. The chain transfer agent is defined, for example, in Polymer Dictionary 3rd Edition (edited by Polymer Society, 2005) pages 683-684. As the chain transfer agent, for example, a compound group having SH, PH, SiH, GeH in the molecule is used. These can donate hydrogen to low-activity radical species to generate radicals, or can be oxidized and then deprotonated to generate radicals. In particular, thiol compounds (for example, 2-mercaptobenzimidazoles, 2-mercaptobenzthiazoles, 2-mercaptobenzoxazoles, 3-mercaptotriazoles, 5-mercaptotetrazoles, etc.) are preferably used for the photosensitive layer. be able to.

  The content of the chain transfer agent is preferably 0.01 to 20 parts by mass, more preferably 1 to 10 parts by mass, and particularly preferably 1 to 5 parts by mass with respect to 100 parts by mass of the total solid content of the photosensitive layer. is there.

  The photosensitive layer may further contain various additives as necessary. Additives include surfactants for promoting developability and improving the surface of the coating, hydrophilic polymers for improving developability and dispersion stability of microcapsules, and visual and non-image areas visible Colorants and print-out agents for polymerization, polymerization inhibitors for preventing unnecessary thermal polymerization of polymerizable compounds during production or storage of the photosensitive layer, higher fat derivatives for preventing polymerization inhibition by oxygen, etc. Hydrophobic low molecular weight compounds, inorganic fine particles for improving the strength of the cured film in the image area, organic fine particles, co-sensitizers for improving sensitivity, plasticizers for improving plasticity, and the like. All of these compounds are known, for example, paragraph numbers [0161] to [0215] of JP-A-2007-206217, paragraph number [0067] of JP-T-2005-509192, paragraphs of JP-A-2004-310000. The compounds described in the numbers [0023] to [0026] and [0059] to [0066] can be used. As for the surfactant, a surfactant which may be added to the developer described later can also be used.

(Formation of photosensitive layer)
The photosensitive layer in the lithographic printing plate precursor according to the invention is not particularly limited in the formation method, and can be formed by a known method. The photosensitive layer is formed by dispersing or dissolving each of the necessary photosensitive layer components in a solvent to prepare and apply a coating solution. Examples of the solvent used include methyl ethyl ketone, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, and γ-butyllactone. It is not limited. A solvent is used individually or in mixture. The solid content concentration of the coating solution is preferably 1 to 50% by mass.

The coating amount (solid content) of the photosensitive layer is preferably 0.3 to 3.0 g / m ² . Various methods can be used as a coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.
In order to contain the (A) copolymer in the photosensitive layer or the undercoat layer, the (A) copolymer can be added to the photosensitive layer coating solution or the undercoat layer coating solution. If the the (A) copolymer is contained in the photosensitive layer, wherein the copolymer (A) content of the (solid) is preferably ^{0.1~100mg / m 2, 1~30mg / m} 2 is More preferably, 5 to 24 mg / m ² is even more preferable.

<Support>
The support used for the lithographic printing plate precursor according to the invention is not particularly limited as long as it is a dimensionally stable plate-like hydrophilic support. As the support, an aluminum plate is particularly preferable. Prior to using the aluminum plate, it is preferable to perform surface treatment such as roughening treatment or anodizing treatment. The surface roughening treatment of the aluminum plate is carried out by various methods. For example, mechanical surface roughening treatment, electrochemical surface roughening treatment (surface roughening treatment to dissolve the surface electrochemically), chemical Surface roughening treatment (roughening treatment that selectively dissolves the surface chemically). For these treatments, the methods described in paragraph numbers [0241] to [0245] of JP-A-2007-206217 can be preferably used.
The support preferably has a center line average roughness of 0.10 to 1.2 μm. Within this range, good adhesion to the photosensitive layer, good printing durability and good stain resistance can be obtained.
The color density of the support is preferably 0.15 to 0.65 in terms of reflection density value. Within this range, good image formability by preventing halation during image exposure and good plate inspection after development can be obtained.
The thickness of the support is preferably from 0.1 to 0.6 mm, more preferably from 0.15 to 0.4 mm, and even more preferably from 0.2 to 0.3 mm.

<Hydrophilic treatment>
In the lithographic printing plate precursor according to the invention, it is also preferable to perform a hydrophilic treatment on the surface of the support in order to improve the hydrophilicity of the non-image area and prevent printing stains.
Examples of the hydrophilization treatment of the support surface include alkali metal silicate treatment in which the support is immersed in an aqueous solution such as sodium silicate or electrolytic treatment, a method of treatment with potassium zirconate fluoride, a method of treatment with polyvinylphosphonic acid, and the like. Although mentioned, the method of immersing in the polyvinylphosphonic acid aqueous solution is used preferably.

[Other layers optionally provided between the support and the photosensitive layer]
In the lithographic printing plate precursor according to the invention, it is also preferable to provide an undercoat layer between the support and the photosensitive layer in order to improve the hydrophilicity of the non-image area and prevent printing stains.

<Protective layer>
In the lithographic printing plate precursor according to the invention, a protective layer (oxygen blocking layer) is preferably provided on the photosensitive layer in order to block diffusion and penetration of oxygen that hinders the polymerization reaction during exposure. As the material for the protective layer, either a water-soluble polymer or a water-insoluble polymer can be appropriately selected and used, and two or more kinds can be mixed and used as necessary. Specific examples include polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl pyrrolidone, water-soluble cellulose derivatives, poly (meth) acrylonitrile, and the like. Among these, it is preferable to use a water-soluble polymer compound having relatively excellent crystallinity. Specifically, using polyvinyl alcohol as a main component gives particularly good results in terms of basic characteristics such as oxygen barrier properties and development removability.

  The polyvinyl alcohol used in the protective layer may be partially substituted with an ester, ether or acetal as long as it contains the unsubstituted vinyl alcohol units necessary for having the necessary oxygen barrier properties and water solubility. Similarly, some of them may have other copolymer components. Polyvinyl alcohol is obtained by hydrolyzing polyvinyl acetate. Specific examples of polyvinyl alcohol include those having a hydrolysis degree of 69.0 to 100 mol% and a number of polymerization repeating units in the range of 300 to 2400. Specifically, PVA-102, PVA-103, PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, manufactured by Kuraray Co., Ltd. PVA-CST, PVA-HC, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-235, PVA-217EE, PVA-217E, PVA- 220E, PVA-224E, PVA-403, PVA-405, PVA-420, PVA-424H, PVA-505, PVA-617, PVA-613, PVA-706, L-8 and the like. Polyvinyl alcohol can be used alone or in combination. Content in the protective layer of polyvinyl alcohol becomes like this. Preferably it is 20-95 mass%, More preferably, it is 30-90 mass%.

  Also, modified polyvinyl alcohol can be preferably used. In particular, acid-modified polyvinyl alcohol having a carboxylic acid group or a sulfonic acid group is preferably used. Specific examples include polyvinyl alcohols described in JP-A-2005-250216 and JP-A-2006-259137.

In the case of using a mixture of polyvinyl alcohol and other materials, the component to be mixed is preferably modified polyvinyl alcohol, polyvinyl pyrrolidone or a modified product thereof from the viewpoint of oxygen barrier properties, development removability, and the content in the protective layer. Is 3.5 to 80% by mass, preferably 10 to 60% by mass, and more preferably 15 to 30% by mass.

  The protective layer can be provided with flexibility by adding glycerin, dipropylene glycol or the like in an amount corresponding to several mass% with respect to the polymer. In addition, anionic surfactants such as sodium alkyl sulfate and sodium alkyl sulfonate, amphoteric surfactants such as alkylaminocarboxylate and alkylaminodicarboxylate, and nonionic surfactants such as polyoxyethylene alkylphenyl ether An amount corresponding to several mass% can be added to the polymer.

  Further, the protective layer preferably contains an inorganic layered compound for the purpose of improving the oxygen barrier property and the photosensitive layer surface protective property. Among inorganic layered compounds, fluorine-based swellable synthetic mica, which is a synthetic inorganic layered compound, is particularly useful. Specifically, inorganic layered compounds described in JP-A No. 2005-119273 are preferable.

The coating amount of the protective layer is preferably 0.05 to 10 g / m ^2, when the protective layer contains the inorganic stratiform compound, if still more preferably 0.1-5 g / m ^2, not containing an inorganic layered compound Is more preferably 0.5 to 5 g / m ² .

<Back coat layer>
In the lithographic printing plate precursor according to the invention, a backcoat layer can be provided on the back surface of the support, if necessary. As the back coat layer, for example, an organic polymer compound described in JP-A-5-45885, an organometallic compound or an inorganic metal compound described in JP-A-6-35174 is hydrolyzed and polymerized. Preferable examples include a coating layer made of a metal oxide obtained by condensation. Among them, it is inexpensive to use a silicon alkoxy compound such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , Si (OC ₄ H ₉ ) _4. It is preferable in terms of easy availability.

[Method for producing planographic printing plate]
A lithographic printing plate can be produced by subjecting the lithographic printing plate precursor of the present invention to image exposure and development.
The method for producing a lithographic printing plate according to the present invention comprises an exposure step of imagewise exposing the lithographic printing plate precursor according to the present invention; and developing the exposed lithographic printing plate precursor with a developer having a pH of 2 to 14 A step of removing the non-exposed portion of the photosensitive layer and the protective layer simultaneously in the presence of the developer.
The method for producing a lithographic printing plate of the present invention comprises a step of forming a protective layer on the surface of the photosensitive layer opposite to the support; the development further comprising a surfactant in the development step It is preferable to include a step of simultaneously removing the photosensitive layer in the non-exposed area and the protective layer in the presence of the liquid (however, it does not include a water washing step). Comprises a step of exposing the planographic printing plate precursor of the present invention imagewise and a step of supplying printing ink and dampening water on a printing machine to remove the photosensitive layer in the non-exposed area. And
Hereinafter, the preferable aspect of each process is demonstrated in order about the manufacturing method of the lithographic printing plate of this invention. According to the method for producing a lithographic printing plate of the present invention, the lithographic printing plate precursor of the present invention can produce a lithographic printing plate even when the development step includes a water washing step.

<Exposure process>

The method for producing a lithographic printing plate of the present invention includes an exposure step of imagewise exposing the lithographic printing plate precursor of the present invention. The planographic printing plate precursor of the present invention is imagewise exposed by laser exposure through a transparent original image having a line image, a halftone dot image or the like, or by laser beam scanning by digital data.
The wavelength of the light source is preferably 300 to 450 nm or 750 to 1400 nm. In the case of a light source of 300 to 450 nm, a lithographic printing plate precursor having a sensitizing dye having an absorption maximum in this wavelength region in the photosensitive layer is preferably used, and in the case of a light source of 750 to 1400 nm, it has absorption in this wavelength region. A lithographic printing plate precursor containing an infrared absorber as a sensitizing dye in the photosensitive layer is preferably used. As the light source of 300 to 450 nm, a semiconductor laser is suitable. As a light source of 750 to 1400 nm, a solid laser and a semiconductor laser emitting infrared rays are suitable. 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, a flat bed system, and the like.
Image exposure can be performed by a conventional method using a plate setter or the like. In the case of on-press development, the lithographic printing plate precursor may be mounted on a printing press and then image exposure may be performed on the printing press.

<Development process>
Development processing is (1) a method of developing with a developer having a pH of 2 to 14 (developer processing method), or (2) a method of developing while adding dampening water and / or ink on a printing press ( (On-press development system).

(Developer processing method)
In the developer processing system, the image-exposed lithographic printing plate precursor is processed with a developer having a pH of 2 to 14, and the photosensitive layer in the non-exposed area is removed to prepare a lithographic printing plate.
In the development processing using a highly alkaline developer (pH 12 or more), usually, the protective layer is removed by a pre-water washing step, then alkali development is performed, the alkali is washed away by water in the post-water washing step, gum solution treatment is performed, and drying is performed. A lithographic printing plate is produced by drying in the process.
According to a first preferred embodiment of the present invention, a developer having a pH of 2-14 is used. In this embodiment, it is preferable that a surfactant or a water-soluble polymer compound is contained in the developer, whereby the development and the gum solution treatment can be performed simultaneously. Therefore, the post-water washing step is not particularly required, and the development-gum solution treatment can be performed with one solution.
Further, the pre-water washing step is not particularly required, and the protective layer can be removed simultaneously with the development-gum solution treatment. In the method for producing a lithographic printing plate of the present invention, after the development-gum treatment, for example, it is preferable to perform drying after removing excess developer using a squeeze roller.

  The developer treatment of the lithographic printing plate precursor according to the invention is carried out in accordance with a conventional method at a temperature of 0 to 60 ° C., preferably about 15 to 40 ° C., for example, by immersing the exposed lithographic printing plate precursor in a developer and brushing It can be performed by a method of rubbing with a brush, a method of spraying a developer by spraying and rubbing with a brush.

  The development processing with the developer can be preferably performed by an automatic development processor equipped with a developer supply means and a rubbing member. An automatic developing processor using a rotating brush roll as the rubbing member is particularly preferable. Further, the automatic processor preferably includes a means for removing excess developer such as a squeeze roller and a drying means such as a warm air device after the development processing means. Furthermore, the automatic development processor may be provided with a preheating means for heat-treating the lithographic printing plate precursor after image exposure before the development processing means.

An example of an automatic developing processor used in the method for preparing a lithographic printing plate according to the present invention will be briefly described with reference to FIG.
An automatic development processor 100 shown in FIG. 1 includes a chamber having an outer shape formed by a machine frame 202, and is preheated continuously formed along the transport direction (arrow A) of the transport path 11 of the planographic printing plate precursor. It has a (preheat) unit 200, a developing unit 300, and a drying unit 400.
The preheating unit 200 includes a heating chamber 208 having a carry-in port 212 and a carry-out port 218, and a skewer roller 210, a heater 214, and a circulation fan 216 are disposed therein.

The developing unit 300 is separated from the preheating unit 200 by an outer panel 310, and the outer panel 310 is provided with a slit-shaped insertion port 312.
Inside the developing unit 300, a processing tank 306 having a developing tank 308 filled with a developer and an insertion roller pair 304 for guiding the planographic printing plate precursor into the processing tank 306 are provided. The upper part of the developing tank 308 is covered with a shielding lid 324.

Inside the developing tank 308, a guide roller 344 and a guide member 342, a submerged roller pair 316, a brush roller pair 322, a brush roller pair 326, and a carry-out roller pair 318 are arranged in parallel from the upstream side in the transport direction. The lithographic printing plate precursor conveyed into the developing tank 308 is immersed in the developer and passes between rotating brush roller pairs 322 and 326 to remove non-image portions.
A spray pipe 330 is provided below the pair of brush rollers 322 and 326. The spray pipe 330 is connected to a pump (not shown), and the developer in the developing tank 308 sucked by the pump is ejected from the spray pipe 330 into the developing tank 308.

An overflow port 51 formed at the upper end of the first circulation pipe C1 is provided on the side wall of the developing tank 308, and excess developer flows into the overflow port 51, and the first circulation pipe C1. And is discharged to an external tank 50 provided outside the developing unit 300.
A second circulation pipe C2 is connected to the external tank 50, and a filter portion 54 and a developer supply pump 55 are provided in the second circulation pipe C2. The developer is supplied from the external tank 50 to the developer tank 308 by the developer supply pump 55. In the external tank 50, an upper limit liquid level meter 52 and a lower limit liquid level meter 53 are provided.
The developing tank 308 is connected to the replenishment water tank 71 via the third circulation pipe C3. A water replenishment pump 72 is provided in the third circulation pipe C 3, and water stored in the replenishment water tank 71 is supplied to the developing tank 308 by the water replenishment pump 72.
A liquid temperature sensor 336 is installed on the upstream side of the submerged roller pair 316, and a liquid level meter 338 is installed on the upstream side of the carry-out roller pair 318.

The partition plate 332 disposed between the developing unit 300 and the drying unit 400 is provided with a slit-shaped insertion port 334. A shutter (not shown) is provided in the passage between the developing unit 300 and the drying unit 400, and when the planographic printing plate precursor 11 does not pass through the passage, the passage is closed by the shutter.
The drying unit 400 includes a support roller 402, ducts 410 and 412, a transport roller pair 406, ducts 410 and 412, and a transport roller pair 408 in this order. A slit hole 414 is provided at the tip of the ducts 410 and 412. The drying unit 400 is provided with drying means such as hot air supply means and heat generation means (not shown). The drying unit 400 is provided with a discharge port 404, and the planographic printing plate dried by the drying means is discharged from the discharge port 404.

  The developer used for the developer processing in the present invention contains an aqueous solution having a pH of 2 to 14, or a surfactant. The developer is preferably an aqueous solution containing water as a main component (containing 60% by mass or more of water), in particular, an aqueous solution containing a surfactant (anionic, nonionic, cationic, zwitterionic, etc.) An aqueous solution containing a water-soluble polymer compound is preferred. An aqueous solution containing both a surfactant and a water-soluble polymer compound is also preferred. The pH of the developer is more preferably 3.5 to 13, further preferably 6 to 13, and particularly preferably 6.5 to 10.5. In particular, in a method using a developer having a pH of 2.0 to 10.0, it is extremely difficult to satisfy both stain resistance, printing durability, and suppression of deterioration of stain resistance with time. The reason for this can be explained as follows. That is, when changing the type of the developer using the same lithographic printing plate precursor material, the developer having a pH of 2.0 to 10.0 is less than the conventionally used alkaline developer having a pH of 12 to 13. The stain resistance of the exposed part is deteriorated. Therefore, if the hydrophilicity of the material is increased in order to improve the stain resistance of the developer having a pH of 2.0 to 10.0, the printing durability tends to deteriorate. By using the lithographic printing plate precursor according to the invention, such a developer having a pH of 2.0 to 10.0 can be preferably used.

  The anionic surfactant used in the developer in the present invention is not particularly limited, but fatty acid salts, abietic acid salts, hydroxyalkanesulfonic acid salts, alkanesulfonic acid salts, dialkylsulfosuccinic acid salts, linear alkylbenzenesulfonic acid Salts, branched alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkyl diphenyl ether (di) sulfonates, alkylphenoxy polyoxyethylene alkyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-alkyl-N-oleyl Sodium taurine, disodium N-alkylsulfosuccinic acid monoamide, petroleum sulfonates, sulfated castor oil, sulfated beef oil, sulfate esters of fatty acid alkyl esters Alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkyl phenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphate esters, polyoxyethylene alkyl ethers Phosphoric acid ester salts, polyoxyethylene alkylphenyl ether phosphoric acid ester salts, partial saponification products of styrene-maleic anhydride copolymer, partial saponification products of olefin-maleic anhydride copolymer, naphthalene sulfonate formalin condensates Etc. Of these, alkylbenzene sulfonates, alkylnaphthalene sulfonates, and alkyl diphenyl ether (di) sulfonates are particularly preferably used.

  In the present invention, the cationic surfactant used in the developer is not particularly limited, and conventionally known cationic surfactants can be used. Examples thereof include alkylamine salts, quaternary ammonium salts, alkyl imidazolinium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.

  The nonionic surfactant used in the developer in the present invention is not particularly limited, but is a polyethylene glycol type higher alcohol ethylene oxide adduct, alkylphenol ethylene oxide adduct, alkyl naphthol ethylene oxide adduct, phenol ethylene oxide addition. , Naphthol ethylene oxide adduct, fatty acid ethylene oxide adduct, polyhydric alcohol fatty acid ester ethylene oxide adduct, higher alkylamine ethylene oxide adduct, fatty acid amide ethylene oxide adduct, fat ethylene oxide adduct, polypropylene glycol ethylene oxide Adduct, dimethylsiloxane-ethylene oxide block copolymer, dimethylsiloxane- (propylene oxide-ethylene Lenoxide) block copolymer, fatty acid ester of polyhydric alcohol type glycerol, fatty acid ester of pentaerythritol, fatty acid ester of sorbitol and sorbitan, fatty acid ester of sucrose, alkyl ether of polyhydric alcohol, fatty acid amide of alkanolamines, etc. Can be mentioned. Among these, those having an aromatic ring and an ethylene oxide chain are preferable, and an alkyl-substituted or unsubstituted phenol ethylene oxide adduct or an alkyl-substituted or unsubstituted naphthol ethylene oxide adduct is more preferable.

  In the present invention, the zwitterionic surfactant used in the developer is not particularly limited, and examples thereof include amine oxides such as alkyldimethylamine oxide, betaines such as alkylbetaines, and amino acids such as alkylamino fatty acid sodium. It is done. In particular, alkyldimethylamine oxide which may have a substituent, alkylcarboxybetaine which may have a substituent, and alkylsulfobetaine which may have a substituent are preferably used. Specifically, a compound represented by the formula (2) in paragraph No. [0256] of JP-A-2008-203359, a formula (I), a formula (II) in paragraph No. [0028] of JP-A-2008-276166, A compound represented by the formula (VI) or a compound represented by paragraph numbers [0022] to [0029] of JP-A-2009-47927 can be used.

  Two or more surfactants may be used in the developer. The amount of the surfactant contained in the developer is preferably 0.01 to 20% by mass, and more preferably 0.1 to 10% by mass.

  Examples of the water-soluble polymer compound used in the developer in the present invention include soybean polysaccharide, modified starch, gum arabic, dextrin, fibrin derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and modified products thereof, pullulan, Polyvinyl alcohol and its derivatives, polyvinyl pyrrolidone, polyacrylamide and acrylamide copolymer, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, styrene / maleic anhydride copolymer, polyvinyl sulfonic acid And salts thereof, polystyrenesulfonic acid and salts thereof, and the like.

  A well-known thing can be used for the said soybean polysaccharide, for example, there exists a brand name Soya Five (made by Fuji Oil Co., Ltd.) as a commercial item, and the thing of various grades can be used. What can be preferably used is one in which the viscosity of a 10% by mass aqueous solution is in the range of 10 to 100 mPa / sec.

  As the modified starch, known ones can be used. For example, starch such as corn, potato, tapioca, rice, wheat is decomposed with acid or enzyme in the range of 5 to 30 glucose residues per molecule, It can be made by a method of adding oxypropylene in the inside.

  Two or more water-soluble polymer compounds can be used in combination in the developer. The content of the water-soluble polymer compound in the developer is preferably from 0.1 to 20% by mass, and more preferably from 0.5 to 10% by mass.

  The developer used in the present invention may contain a pH buffer. The developer of the present invention can be used without particular limitation as long as it is a buffering agent that exhibits a buffering action at a pH of 2 to 14. In the present invention, weakly alkaline buffering agents are preferably used. For example, (a) carbonate ions and hydrogen carbonate ions, (b) borate ions, (c) water-soluble amine compounds and ions of the amine compounds, and their Combination use etc. are mentioned. That is, for example, a combination of (a) carbonate ion-bicarbonate ion, (b) borate ion, or (c) water-soluble amine compound-ion of the amine compound exhibits pH buffering action in the developer. Even when the developer is used for a long period of time, fluctuations in pH can be suppressed, and therefore, development loss due to fluctuations in pH, development debris generation and the like can be suppressed. In the method for producing a lithographic printing plate of the present invention, a combination of carbonate ions and hydrogen carbonate ions is particularly preferable.

  In order for carbonate ions and bicarbonate ions to be present in the developer, carbonate and bicarbonate may be added to the developer, or by adjusting the pH after adding carbonate or bicarbonate, Ions and bicarbonate ions may be generated. The carbonate and bicarbonate are not particularly limited, but are preferably alkali metal salts. Examples of the alkali metal include lithium, sodium, and potassium, and sodium is particularly preferable. Alkali metals may be used alone or in combination of two or more.

  The total amount of carbonate ions and bicarbonate ions is preferably 0.05 to 5 mol / L, more preferably 0.07 to 2 mol / L, and particularly preferably 0.1 to 1 mol / L with respect to the developer.

  In the present invention, the developer may contain an organic solvent. Examples of the organic solvent that can be contained include aliphatic hydrocarbons (hexane, heptane, Isopar E, H, G (manufactured by Esso Chemical Co., Ltd.)), aromatic hydrocarbons (toluene, xylene, etc.), halogens, and the like. Hydrocarbons (methylene dichloride, ethylene dichloride, trichlene, monochlorobenzene, etc.) and polar solvents. Examples of polar solvents include alcohols (methanol, ethanol, propanol, isopropanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, 1 -Nonanol, 1-decanol, 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 Ter, ethylene glycol monobenzyl ether, ethylene glycol monophenyl ether, propylene glycol monophenyl ether, methylphenyl carbinol, n-amyl alcohol, methyl amyl alcohol, etc.), 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 monobutyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol acetate, diethyl phthalate, butyl levulinate Etc.), others (triethyl phosphate, tricresyl phosphate, N-phenylethanolamine) , N- phenyldiethanolamine, N- methyldiethanolamine, N- ethyldiethanolamine, 4- (2-hydroxyethyl) morpholine, N, N- dimethylacetamide, N- methylpyrrolidone and the like) and the like.

  Two or more of the organic solvents contained in the developer may be used in combination. 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 organic solvent is preferably less than 40% by mass from the viewpoint of safety and flammability.

  In the present invention, in addition to the above components, the developer may contain a preservative, a chelate compound, an antifoaming agent, an organic acid, an inorganic acid, an inorganic salt, and the like. Specifically, compounds described in paragraph numbers [0266] to [0270] of JP-A-2007-206217 can be preferably used.

  In the present invention, the developer can be used as a developer and a development replenisher for the exposed lithographic printing plate precursor. Further, the present invention can be preferably applied to the automatic developing processor as described above. When developing using an automatic developing processor, the developing solution becomes fatigued according to the amount of processing, and therefore the replenishing solution or fresh developing solution may be used to restore the processing capability.

<On-press development method>
In the on-press development system, an image-exposed lithographic printing plate precursor is supplied with oil-based ink and an aqueous component on a printing machine, and the photosensitive layer in the non-image area is removed to produce a lithographic printing plate.
In other words, after image exposure of the lithographic printing plate precursor, it is mounted on the printing machine without any development processing, or after the lithographic printing plate precursor is mounted on the printing machine, image exposure is performed on the printing machine. When printing is performed by supplying an oil-based ink and an aqueous component, an uncured photosensitive layer is dissolved or dispersed by an supplied oil-based ink and / or aqueous component in a non-image area at an early stage of printing. And the hydrophilic surface is exposed in that portion. On the other hand, in the exposed portion, the photosensitive layer cured by exposure forms an oil-based ink receiving portion having a lipophilic surface. Oil-based ink or water-based component may be first supplied to the plate surface, but oil-based ink may be supplied first in order to prevent the aqueous component from being contaminated by the removed photosensitive layer component. preferable. 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. As the oil-based ink and the aqueous component, ordinary lithographic printing ink and fountain solution are preferably used.

  In the method for producing a lithographic printing plate from the lithographic printing plate precursor according to the present invention, the entire lithographic printing plate precursor is exposed before exposure, during exposure, and from exposure to development, regardless of the development method. You may heat. Such heating promotes the image forming reaction in the photosensitive layer, and may bring about advantages such as improvement in sensitivity and printing durability and stabilization of sensitivity. In the case of the developer processing method, it is also effective to perform whole surface post-heating or whole surface exposure on the image after the development processing for the purpose of improving the image strength and printing durability. Usually, heating before development is preferably performed under a mild condition of 150 ° C. or less. If the temperature is too high, problems such as curing of the non-image area may occur. Very strong conditions are used for heating after development. Usually, it is the range of 100-500 degreeC. If the temperature is low, sufficient image reinforcing action cannot be obtained. If the temperature is too high, problems such as deterioration of the support and thermal decomposition of the image area may occur.

  Hereinafter, the features of the present invention will be described more specifically with reference to examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Accordingly, the scope of the present invention should not be construed as being limited by the specific examples shown below. In this example, “part” indicating the blending amount indicates “part by mass” unless otherwise specified.

[Example A] Synthesis of copolymer <Synthesis of specific polymer compound P-48>
In a 500 ml three-necked flask, dimethyl-N-methacryloyloxyethyl-N-carboxymethyl-ammonium betaine (manufactured by Osaka Organic Chemical Industry) (12.5 g), vinylphosphonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) (22.5 g) ), 2-methacrylamidoethylamine hydrochloride (synthetic product) (12.58 g) and distilled water (150 g) were added, and the mixture was heated and stirred at 60 ° C. for 10 minutes in a nitrogen stream. Thereafter, polymerization initiator VA-046B (manufactured by Wako Pure Chemical Industries, Ltd.) (0.9 g) was dissolved in distilled water (40 g) and added dropwise over 3 hours. Thereafter, VA-046B (0.9 g) was added again, and the mixture was heated at 80 ° C. for 3 hours and cooled after the heating was completed.
NaOH was added to the resulting polymer solution to adjust the pH to 10. Thereafter, 4-OH-TEMPO (manufactured by Tokyo Chemical Industry Co., Ltd.) (0.2 g) was added and heated to 55 ° C., and methacrylic anhydride (manufactured by Aldrich) (45 g) was added dropwise over 1 hour. After completion of dropping, the temperature was maintained at 55 ° C. for 6 hours. Thereafter, ethyl acetate (500 g) was added to recover the lower layer. Amberlyst R15 (manufactured by Aldrich) (50 g) was added as an ion exchange resin to the recovered lower layer, and after stirring at room temperature for 2 hours, Amberlyst R15 was removed by filtration to obtain an aqueous solution of the specific polymer compound P-4. . It was 21,000 as a result of measuring the weight average molecular weight (Mw) of the obtained specific high molecular compound P-48 by the gel-battery chromatography method (GPC) which used polyethyleneglycol as the standard substance.
In the same manner for other specific polymer compounds of the present invention, the monomer component of the repeating unit in the above synthesis example is changed, and the type and amount of the reactive reagent used for the amino group substitution reaction are changed. Further, if necessary, it was synthesized by an existing synthesis method.

[Example B] Synthesis of specific low molecular compound <Synthesis of specific low molecular compound b-124>
Triethylamine (manufactured by Wako Pure Chemical Industries, Ltd.) (10 g), 1,4-butane sultone (manufactured by Wako Pure Chemical Industries, Ltd.) (13.46 g) and acetonitrile (100 ml) were added to a 300 ml three-necked flask and stirred at 80 ° C. for 2 hours. . Thereafter, the solvent was distilled off under reduced pressure, and the precipitated white solid was washed with methyl isobutyl ketone and dried to obtain a specific low molecular compound b-124 “(21 g). In addition, another specific polymer of the present invention. The compounds were synthesized in the same manner by changing the monomer component of the repeating unit in the above synthesis example, and if necessary, by an existing synthesis method.

<Synthesis of Specific Low Molecular Compound b-102>
Triethylamine (manufactured by Wako Pure Chemical Industries, Ltd.) (10 g), ethyl bromoacetate (manufactured by Tokyo Chemical Industry) (16.39 g) and acetonitrile (100 ml) were added to a 300 ml three-necked flask and stirred at 50 ° C. for 6 hours. Thereafter, the solvent was distilled off under reduced pressure, and the obtained yellow oil was dissolved in a mixed solution of 50 g of methanol / 50 g of water. Silver oxide (manufactured by Wako Pure Chemical Industries, Ltd.) (1 g) was added and stirred for 30 minutes, and then the solvent was distilled off under reduced pressure. The resulting brown oil was washed with acetone and dried under reduced pressure to obtain b-102 (16.4 g).

<Synthesis of Specific Low Molecular Compound b-142>
Ethanol (manufactured by Wako Pure Chemical Industries, Ltd.) (10 g), triethylamine (5 g), and dehydrated tetrahydrofuran (100 ml) were added to a 300 ml three-necked flask and cooled to −10 ° C., and then 2-chloro-2-oxo-1, 3,2-Dioxaphosphorane (manufactured by Tokyo Chemical Industry) (30.92 g) was added dropwise over 1 hour. Thereafter, the temperature was maintained at −10 ° C. for 3 hours, the deposited precipitate was filtered, and then the solvent was distilled off under reduced pressure to obtain 32 g of a yellow liquid. The obtained yellow liquid was dissolved in dehydrated acetonitrile, triethylamine (18 g) was added, and the mixture was reacted at 80 ° C. for 6 hours. The solvent was distilled off under reduced pressure and washed with ethyl acetate / dried under reduced pressure to obtain b-142 (15 g).

(B) Planographic printing plate (1) Preparation of lithographic printing plate precursor

  An undercoat layer (intermediate layer) is formed on any of the following supports, and any of the following photosensitive layers is formed on the undercoat layer, and further, any of the following protective layers is formed. A lithographic printing plate precursor was prepared.

[Preparation of Aluminum Support 1]
In order to remove rolling oil on the surface of an aluminum plate (material: JIS A1050) having a thickness of 0.3 mm, after degreasing at 50 ° C. for 30 seconds using a 10 mass% sodium aluminate aqueous solution, the hair diameter is 0.3 mm. The aluminum surface was grained using 3 bundle-planted nylon brushes and a pumice-water suspension (specific gravity 1.1 g / cm ³ ) having a median diameter of 25 μm and washed well with water. This plate was etched by being immersed in a 25 mass% sodium hydroxide aqueous solution at 45 ° C for 9 seconds, washed with water, further immersed in a 20 mass% nitric acid aqueous solution at 60 ° C for 20 seconds, and washed with water. The etching amount of the grained surface at this time was about 3 g / m ² .

Next, an electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass nitric acid aqueous solution (containing 0.5% by mass of aluminum ions) and a liquid temperature of 50 ° C. The AC power source waveform is electrochemical roughening treatment using a trapezoidal rectangular wave alternating current with a time ratio TP of 0.8 msec until the current value reaches a peak from zero, a duty ratio of 1: 1, and a trapezoidal rectangular wave alternating current. Went. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode.
The amount of electricity in the nitric acid electrolysis was 175 C / dm ² when the aluminum plate was the anode.
Then, water washing by spraying was performed.

Next, a 0.5% by mass hydrochloric acid aqueous solution (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. and nitric acid electrolysis under the condition of an electric quantity of 50 C / dm ² when the aluminum plate is an anode. In the same manner as above, an electrochemical surface roughening treatment was performed, followed by washing with water by spraying. A DC anodized film of 2.5 g / m ² was provided on the plate aluminum using a 15% by mass sulfuric acid aqueous solution (containing 0.5% by mass of aluminum ions) as an electrolyte under a current density of 15 A / dm ² . Thereafter, it was washed with water and dried to produce an aluminum support 1.
The center line average roughness (Ra) of the support thus obtained was measured using a needle having a diameter of 2 μm and found to be 0.51 μm.

[Preparation of aluminum support 2]
The aluminum support 1 was treated with a 1% by mass aqueous solution of sodium silicate at 20 ° C. for 10 seconds to produce an aluminum support 2. When the surface roughness was measured, it was 0.54 μm (Ra display according to JIS B0601).

[Preparation of Aluminum Support 3]
An aluminum plate (material 1050, tempered H16) having a thickness of 0.24 mm was immersed in a 5% aqueous sodium hydroxide solution kept at 65 ° C., degreased for 1 minute, and then washed with water. The aluminum plate was neutralized by immersion in a 10% aqueous hydrochloric acid solution maintained at 25 ° C. for 1 minute, and then washed with water. Next, this aluminum plate was subjected to electrolytic surface roughening with an alternating current for 60 seconds under conditions of 25 ° C. and a current density of 100 A / dm ^{2 in} a 0.3 mass% hydrochloric acid aqueous solution, and then kept at 60 ° C. In addition, desmutting treatment was performed in a 5% aqueous sodium hydroxide solution for 10 seconds. This aluminum plate was anodized in a 15% sulfuric acid aqueous solution at 25 ° C., a current density of 10 A / dm ² , and a voltage of 15 V for 1 minute to produce an aluminum support. When the surface roughness was measured, it was 0.44 μm (Ra display according to JIS B0601).

[Preparation of Aluminum Support 4]
In order to remove rolling oil on the surface of an aluminum plate (material JIS A 1050) having a thickness of 0.3 mm, a degreasing treatment was performed at 50 ° C. for 30 seconds using a 10 wt% sodium aluminate aqueous solution, and then the hair diameter was adjusted to 0. The aluminum surface was grained using ^three 3 mm bundle-planted nylon brushes and a pumice-water suspension (specific gravity 1.1 g / cm ³ ) having a median diameter of 25 μm and washed well with water. This plate was etched by being immersed in a 25 wt% sodium hydroxide aqueous solution at 45 ° C. for 9 seconds, washed with water, further immersed in a 20 wt% nitric acid aqueous solution at 60 ° C. for 20 seconds, and washed with water. The etching amount of the grained surface at this time was about 3 g / m ² .

Next, an electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by weight nitric acid aqueous solution (containing 0.5% by weight of aluminum ions) and a liquid temperature of 50 ° C. The AC power source waveform is electrochemical roughening treatment using a trapezoidal rectangular wave alternating current with a time ratio TP of 0.8 msec until the current value reaches a peak from zero, a duty ratio of 1: 1, and a trapezoidal rectangular wave alternating current. Went. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode.
The amount of electricity in the nitric acid electrolysis was 175 C / dm ² when the aluminum plate was the anode.
Then, water washing by spraying was performed. Subsequently, a 2.5 M phosphoric acid was used as an electrolyte solution, and a direct current anodic oxide film having a voltage of 50 V and a maximum current density of 2 A / dm ² was provided at 1.5 g / m ² , followed by washing and drying.
Then, 100 degreeC water vapor | steam was sprayed on said anodic oxide film for 15 second with the pressure of 1.033 * 10 < ⁵ > Pa, and the sealing process was performed. Then, it was immersed in a polyvinyl phosphonic acid aqueous solution with a liquid temperature of 50 ° C. and 0.4 wt% for 10 seconds, washed with water and dried to obtain a support (4).

(Formation of undercoat layer)
An undercoat layer coating solution having the following composition was applied to each of the aluminum supports 1 to 3 with a bar coater and dried at 100 ° C. for 1 minute to form an undercoat layer. The dry coating amount of the undercoat layer was 12 mg / m ² .

<Undercoat layer coating solution>
-The specific polymer compounds listed in the table below or the following polymer compounds for comparison
0.50g
・ Specific low molecular weight compounds listed in the table below or comparative low molecular weight compounds listed below
In the table, methanol 90.0g
・ Pure water 10.0g

[Formation of photosensitive layer 1]
Photosensitive layer coating solution 1 having the following composition was bar coated on the undercoat layer and then oven-dried at 90 ° C. for 60 seconds to form photosensitive layer 1 having a dry coating amount of 1.3 g / m ² .

<Photosensitive layer coating solution 1>
-The following binder polymer (1) (weight average molecular weight: 80,000) 0.34 g
・ The following polymerizable compound (1) 0.68 g
(PLEX6661-O, manufactured by Degussa Japan)
・ The following sensitizing dye (1) 0.06 g
・ The following polymerization initiator (1) 0.18 g
・ The following chain transfer agent (1) 0.02 g
・ 0.40 g of ε-phthalocyanine pigment dispersion
(Pigment (manufactured by Toyo Ink, No. 700-10 FG CY BLUE) (15 parts by mass), dispersant (allyl methacrylate / methacrylic acid copolymer (weight average molecular weight: 60,000, copolymer molar ratio: 83/17) ) (10 parts by mass), cyclohexanone (15 parts by mass))
-Thermal polymerization inhibitor (N-nitrosophenylhydroxylamine aluminum salt) 0.01 g
-The following fluorosurfactant (1) (weight average molecular weight: 10,000)
0.001g
・ Polyoxyethylene-polyoxypropylene condensate 0.02g
(Pluronic L44, manufactured by ADEKA Corporation)
・ 3.5 g of 1-methoxy-2-propanol
・ Methyl ethyl ketone 8.0g

[Formation of photosensitive layer 2]
The photosensitive layer coating solution 2 having the following components was applied so that the dry coating mass was 1.4 g / m ² and dried at 100 ° C. for 1 minute to form the photosensitive layer 2.

<Photosensitive layer coating solution 2>
Polymerizable compound (polymerizable compound 1) 4.0 parts by mass Binder polymer (Binder B below) (weight average molecular weight: 35,000)
2.0 parts by weight Sensitizing dye (1) 0.32 parts by weight Polymerization initiator (1) 0.61 parts by weight Chain transfer agent (1) 0.57 parts by weight N-nitrosophenylhydroxylamine aluminum salt 0.020 parts by weight Part ε-phthalocyanine pigment dispersion 0.71 part by mass (pigment (15% by mass), dispersant (allyl methacrylate / methacrylic acid copolymer (weight average molecular weight: 60,000, copolymer molar ratio: 83/17) (10 Mass%), solvent (cyclohexanone / methoxypropyl acetate / 1-methoxy-2-propanol = 15 mass% / 20 mass% / 40 mass%))
Fluorine-based nonionic surfactant (Megafac F780, manufactured by DIC Corporation)
0.016 parts by mass Methyl ethyl ketone 47 parts by mass Propylene glycol monomethyl ether 45 parts by mass

[Formation of photosensitive layer 3]
A photosensitive layer coating solution 3 having the following composition was bar-coated on the undercoat layer and then oven-dried at 90 ° C. for 60 seconds to form a photosensitive layer 3 having a dry coating amount of 1.3 g / m ² .
<Photosensitive layer coating solution 3>
-Binder polymer (1) (weight average molecular weight: 50,000) 0.04 g
-The following binder polymer (2) (weight average molecular weight: 80,000) 0.30 g
・ Polymerizable compound (1) 0.17 g
-0.51 g of the following polymerizable compound (2)
・ The following sensitizing dye (2) 0.03 g
・ The following sensitizing dye (3) 0.015 g
・ The following sensitizing dye (4) 0.015 g
・ The above polymerization initiator (1) 0.13 g
・ Chain transfer agent: Mercaptobenzothiazole 0.01g
・ 0.40 g of ε-phthalocyanine pigment dispersion
(Pigment (15 parts by mass), dispersant (allyl methacrylate / methacrylic acid copolymer (weight average molecular weight: 60,000, copolymer molar ratio: 83/17)) (10 parts by mass), cyclohexanone (15 parts by mass))
・ Thermal polymerization inhibitor 0.01g
(N-nitrosophenylhydroxylamine aluminum salt)
-Fluorosurfactant (1) (weight average molecular weight: 10,000) 0.001 g
・ 3.5 g of 1-methoxy-2-propanol
・ Methyl ethyl ketone 8.0g

[Formation of photosensitive layer 4]
Photosensitive layer coating solution 4 having the following composition was bar coated on the undercoat layer and then oven-dried at 100 ° C. for 60 seconds to form photosensitive layer 4 having a dry coating amount of 1.0 g / m ² . The photosensitive layer coating solution 4 was prepared by mixing and stirring the following photosensitive solution (1) and hydrophobized precursor solution (1) immediately before coating.

<Photosensitive solution (1)>
・ The following binder polymer (3) 0.162 g
・ The following infrared absorber (1) 0.030 g
-The following polymerization initiator (3) 0.162g
・ Polymerizable compound (Aronix M215, manufactured by Toagosei Co., Ltd.) 0.385 g
・ Pionine A-20 (Takemoto Yushi Co., Ltd.) 0.055g
・ The following oil sensitizer (1) 0.044 g
・ 0.008 g of the above-mentioned fluorosurfactant (1)
・ Methyl ethyl ketone 1.091g
・ 1-methoxy-2-propanol 8.609g

<Hydrophobic precursor liquid (1)>
-Hydrophobic precursor aqueous dispersion (1) below 2.640 g
・ Distilled water 2.425g

(Production of hydrophobized precursor aqueous dispersion (1))
A 1000 ml four-necked flask is equipped with a stirrer, thermometer, dropping funnel, nitrogen inlet tube and reflux condenser, and distilled water (350 mL) is added while deoxygenating by introducing nitrogen gas, and the internal temperature is 80 ° C. Heated until Sodium dodecyl sulfate (1.5 g) was added as a dispersant, ammonium persulfide (0.45 g) was added as an initiator, and then a mixture of glycidyl methacrylate (45.0 g) and styrene (45.0 g) was added dropwise. It dropped from the funnel over about 1 hour. After the completion of the dropwise addition, the reaction was continued as it was for 5 hours, and then the unreacted monomer was removed by steam distillation. Thereafter, the mixture was cooled and adjusted to pH 6 with ammonia water, and finally purified water was added so that the nonvolatile content was 15% by mass to obtain a hydrophobized precursor aqueous dispersion (1) composed of polymer fine particles. The particle size distribution of the polymer fine particles had a maximum value at a particle size of 60 nm.

  The particle size distribution is obtained by taking an electron micrograph of polymer fine particles, measuring the total particle size of 5000 particles on the photograph, and dividing the obtained particle size measured value from 0 to 0 on a logarithmic scale by 50. Then, the frequency of appearance of each particle size was plotted and determined. For non-spherical particles, the particle size value of spherical particles having the same particle area as that on the photograph was used as the particle size.

[Formation of photosensitive layer (5)]
A photosensitive layer coating solution (5) having the following composition was coated on a bar and oven dried at 82 ° C. for 90 seconds to form a photosensitive layer having a dry coating amount of 1.2 g / m ² .

<Photosensitive layer coating solution (5)>
-Binder polymer (4) 1.75 parts-Hybridur 580 (manufactured by Air Products and Chemicals, urethane-acrylic hybrid polymer dispersion (40%)) 2.34 parts as solids-SR399 (available from Sartomer Japan, Inc.) Possible dipentaerythritol pentaacrylate) 2.66 parts NK-Ester A-DPH (dipentaerythritol hexaacrylate available from Nakamura Synthetic Chemical Co., Ltd.) 2.66 parts CD9053 (Sartomer Japan, Inc.) 0.53 parts bis-tert-butylphenyliodonium tetraphenylborate
0.96 parts · Fluor N2900 (surfactant available from Cytnix) 0.11 parts · Pigment1 0.73 parts · Infrared absorbent (2) 0.27 parts · Ion-exchanged water 13.77 parts · 1 -Methoxy-2-propanol 48.18 parts 2-butyrolactone 13.77 parts 2-butanone 1.94 parts

Binder polymer (4)

  The above Disperbyk167 is a dispersant available from Byk Chemie.

[Formation of photosensitive layer (6)]
In the photosensitive layer coating solution 2, the polymerizable compound 1 was changed to the following polymerizable compound, and others were carried out in the same manner to prepare a photosensitive layer (6).

[Formation of Protective Layer 1]
The protective layer coating solution 1 having the following composition was applied using a bar so that the dry coating amount was 0.75 g / m ^2, and then dried at 125 ° C. for 70 seconds to form the protective layer 1.

<Protective layer coating solution 1>
Polyvinyl alcohol (degree of saponification: 98 mol%, degree of polymerization: 500) 40 g
・ Polyvinylpyrrolidone (molecular weight: 50,000) 5g
・ Poly [vinyl pyrrolidone / vinyl acetate (1/1)] (molecular weight: 70,000) 0.5 g
・ Surfactant (Emalex 710, manufactured by Nippon Emulsion Co., Ltd.) 0.5g
・ 950g of water

[Formation of Protective Layer 2]
The protective layer coating solution 2 having the following composition was applied using a bar so that the dry coating amount was 0.75 g / m ^2, and then dried at 125 ° C. for 70 seconds to form the protective layer 2.

<Protective layer coating solution 2>
-1.5 g of the following inorganic layered compound dispersion (1)
・ 0.55 g of 6% by weight aqueous solution of sulfonic acid-modified polyvinyl alcohol
(Nippon Synthetic Chemical Industry Co., Ltd. CKS50, saponification degree 99 mol% or more, polymerization degree 300)
・ Polyvinyl alcohol 6 mass% aqueous solution 0.03g
(Kuraray Co., Ltd. PVA-405, saponification degree 81.5 mol%, polymerization degree 500, 6 mass% aqueous solution)
-1% by weight aqueous solution of surfactant (Emulex 710 manufactured by Nippon Emulsion Co., Ltd.) 0.86g
・ Ion-exchanged water 6.0g

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

[Formation of Protective Layer 3]
The following protective layer coating solution (3) was changed to the following protective layer coating solution (3) and bar-coated to form a protective layer having a dry coating amount of 2.1 g / m ² .
[Coating liquid for protective layer (3)]
-Polyvinyl alcohol (PVA-105 manufactured by Kuraray Co., Ltd., saponification degree of 98 mol% or more,
Degree of polymerization 500) 6% by weight aqueous solution 66.33 parts Surfactant manufactured by Nippon Emulsion Co., Ltd. (Emalex 710) 1% by weight aqueous solution 0.86 parts ion-exchanged water 12.60 parts

In Tables 1 to 4, specific polymer compounds are those shown in the specific examples of the copolymer (A) of the present invention. In addition, the high molecular compounds E-1 to E-3 for comparative examples used in the lithographic printing plate precursors H-1 to 20 are comparative compounds, and their structures are shown below.

(2) Evaluation of planographic printing plate precursor [exposure, development and printing]
Each lithographic printing plate precursor shown in the following table is attached to FUJIFILM Electronic Imaging Ltd. Image exposure was performed with a Violet semiconductor laser plate setter Vx9600 (InGaN-based semiconductor laser (with an emission wavelength of 405 nm ± 10 nm / output 30 mW) mounted) manufactured by (FFEI). Image exposure was performed at a resolution of 2,438 dpi using an FM screen (TAFFETA 20) manufactured by Fuji Film Co., Ltd., with a plate surface exposure of 0.05 mJ / cm ² so that the dot area ratio was 50%.
Next, after preheating at 100 ° C. for 30 seconds, development processing was carried out using an automatic developing processor having a structure as shown in FIG. The automatic processor has one brush roll with an outer diameter of 50 mm in which fibers made of polybutylene terephthalate (hair diameter 200 μm, hair length 17 mm) are implanted, and rotates 200 times per minute in the same direction as the conveying direction ( The peripheral speed of the brush tip was 0.52 m / sec). The temperature of the developer was 30 ° C. The planographic printing plate precursor was transported at a transport speed of 100 cm / min. After the development processing, drying was performed in a drying section. The drying temperature was 80 ° C. However, when the developer 2 was used, it was washed with water before the post-development drying step.

<Developer 1>
・ Surfactant-1 (manufactured by Kawaken Fine Chemicals Co., Ltd .: Softazoline LPB-R) 15 g
・ Surfactant-2 (Kawaken Fine Chemical Co., Ltd .: Softazoline LAO) 4g
-Chelating agent Ethylenediamine succinic acid trisodium (InnoSpec special chemicals: Octaquest E30)
0.68g
・ 2-Bromo-2-nitropropane-1,3diol 0.025g
・ 2-Methyl-4-isothiazolin-3-one 0.025g
・ Silicone-based antifoaming agent (GE Toshiba Silicones Co., Ltd .: TSA739) 0.15 g
・ Sodium gluconate 1.5g
・ Sodium carbonate 1.06g
・ Sodium bicarbonate 0.52g
・ Water 77.04g
(PH: 9.8)

<Developer 2>
・ Potassium hydroxide 0.15g
・ New Coal B13 (Nippon Emulsifier) 5.0g
・ Chillest 400 (chelating agent) (manufactured by Kirest Co., Ltd.) 0.1g
・ Distilled water 94.75g
(PH: 12.05)

<Developer 3>
・ Gum Arabic 25.0g
・ Enzyme-modified potato starch (manufactured by Nissho Chemical) 70.0 g
・ Dioctylsulfosuccinate sodium salt 5.0 g
・ Primary ammonium phosphate 1.0g
・ Citric acid 1.0g
・ 0.01 g of 2-bromo-2-nitropropane-1,3-diol
-2-methyl-4-isothiazolin-3-one 0.01 g
-70.0 g of the following amphoteric surfactant (Compound W-1)
-3.0 g of the following anionic surfactant (compound AN-1)
・ Distilled water 824.98 g
(Phosphoric acid and sodium hydroxide added to adjust pH to 4.5)

<Developer 4>
・ Water 937.2g
-23.8 g of the following anionic surfactant (Compound W-2)
・ Phosphoric acid 3g
・ Phenoxypropanol 5g
・ Triethanolamine 6g
・ Potatodextrin 25g

<Developer 5>
・ Water 88.6g
-2.4 g of the following nonionic surfactant (W-3)
-2.4 g of the following nonionic surfactant (W-4)
・ Nonionic surfactant 1.0g
(Emalex 710, manufactured by Nippon Emulsion Co., Ltd.)
・ Phenoxypropanol 1.0g
・ Octanol 0.6g
・ N- (2-hydroxyethyl) morpholine 1.0 g
・ Triethanolamine 0.5g
・ Sodium gluconate 1.0g
・ Trisodium citrate 0.5g
・ Ethylenediaminetetraacetate tetrasodium 0.05g
・ Polystyrenesulfonic acid 1.0g
(Versa TL77 (30% solution), manufactured by Alco Chemical)
(Add phosphoric acid and adjust pH to 7.0)

<Developer 6 (pH: 7.0)>
・ Water: 10,000 parts combined with other ingredients ・ Ethylene glycol mono-n-hexyl ether 80 parts (octanol / water partition coefficient = 1.86, solubility in water = 1.0 g / 100 ml water)
・ 500 parts of the following nonionic surfactant (W-5)

  The obtained lithographic printing plate is attached to a printing machine SOR-M manufactured by Heidelberg, and fountain solution (EU-3 (etch solution manufactured by FUJIFILM Corporation) / water / isopropyl alcohol = 1/89/10 (volume ratio). )) And TRANS-G (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.), printing was performed at a printing speed of 6000 sheets per hour.

[Evaluation]
Each lithographic printing plate precursor was evaluated for printing durability, stain resistance, stain resistance after aging and developability as follows. The results are shown in the table below.

<Print durability>
As the number of printed sheets increased, the photosensitive layer gradually worn out and the ink acceptance decreased, so the ink density on the printing paper decreased. In the printing plate exposed with the same exposure amount, the printing durability was evaluated by the number of printed sheets when the ink density (reflection density) was reduced by 0.1 from the start of printing. Evaluation of printing durability was carried out using Examples 1 to 52, Comparative Examples 1 to 5 as Comparative Example 3, and Examples 53 to 67 and Comparative Examples 6 to 10 as Comparative Example 8 as a reference (100). The relative printing durability is defined as follows. The larger the relative printing durability number, the higher the printing durability.
Relative printing durability = (printing durability of the target lithographic printing plate precursor) / (printing durability of the standard lithographic printing plate precursor)

<Stain resistance>
The printed material on the 20th sheet was taken out after the start of printing, and the stain resistance was evaluated based on the ink density adhered to the non-image area. Ink adhesion on the non-image area does not always occur uniformly, and thus was indicated by a visual evaluation score per 75 cm ² . The score of the visual evaluation is 10 points when the ink adhesion area ratio of the non-image area is 0%, 9 points exceeding 0% and 9 points or less, 8 points exceeding 20% and 10 points exceeding 20%, and 30 points exceeding 30%. %, 7 points below 30%, 6 points below 40% and below, 5 points above 40% and below 50%, 4 points above 50% and below 60%, 3 points above 60% and below 70%, Over 70% and 80% or less were assigned 2 points, over 80% and 90% or less were assigned 1 point, and over 90% were assigned 0 points. The higher the score, the better the stain resistance.

<Stain resistance after aging>
After preparing a lithographic printing plate, it was left for 3 days in a constant temperature and humidity chamber set at 60 ° C. and a relative humidity of 60%. Using this printing plate, the stain resistance after the elapse of time was evaluated in the same manner as the above-described stain resistance evaluation. The higher the score, the better the stain resistance after aging.

<Developability>
The development processing was performed while changing to various transport speeds, and the cyan density of the non-image portion of the obtained lithographic printing plate was measured with a Macbeth densitometer. The transport speed at which the cyan density of the non-image area was equal to the cyan density of the aluminum support was determined and used as developability. The evaluation of developability is as follows, with Examples 1 to 52, Comparative Examples 1 to 5 as Comparative Example 3 and Examples 53 to 67 and Comparative Examples 6 to 10 as Comparative Example 8 as a reference (100). It was represented by the relative developability defined in 1. The larger the value of the relative developability, the higher the developability and the better the performance.
Relative developability = (transport speed of target lithographic printing plate precursor) / (transport speed of reference lithographic printing plate precursor)

<Applied surface>
In the surface state of the lithographic printing plate precursor before exposure, which was applied to the protective layer, the surface was visually observed and evaluated under the following evaluation conditions.
○: Unevenness in cyan density is not confirmed. ○ △: Streaky cyan density unevenness has occurred. △: In addition to the occurrence of streaky cyan density unevenness, spots with a diameter of less than 5 mm with reduced cyan density have occurred. X: Circular spots with a cyan density of 5 mm or more in diameter are reduced.

As is apparent from the above table, the examples using the (A) specific high molecular compound and the (B) specific low molecular compound improve the coating surface condition, and improve the printing durability, stain resistance, and time. It was found to be excellent in stain resistance and developability.
On the other hand, even when (A) the specific high molecular compound is included in the undercoat layer, the coated surface shape is very deteriorated in Comparative Examples 3 and 8 where (B) the specific low molecular compound is not included, and the printing durability and stain resistance are deteriorated. It was found that the balance between stain resistance and developability after aging was poor.
Further, from Comparative Examples 2 and 6, when (A) the specific high molecular compound does not have a hydrophilic group having a specific structure, (B) even if a specific low molecular compound is added, the coated surface state, printing durability, and stain resistance It was found that the effect of improving the stain resistance and developability after aging could hardly be confirmed.
In Comparative Examples 4 and 9 using the polymer compound E-2 for Comparative Example, which does not have a support adsorbing group and does not satisfy the requirements of (A) the specific polymer compound, the printing durability is greatly deteriorated. Was found to be confirmed.
Further, in Comparative Examples 5 and 10 using the polymer compound E-3 for Comparative Example, which has a molecular weight of less than 5000 and does not satisfy the requirements of (A) the specific polymer compound, in addition to the performance degradation due to the low molecular weight (B) The effect of adding the specific low molecular weight compound was hardly confirmed, and it was found that the performance balance of the coated surface state, printing durability, stain resistance, stain resistance after aging and developability was low.
In the present invention, it can be said that the evaluation is particularly high when the printing durability is excellent.

[Exposure, development and printing]
Each lithographic printing plate precursor shown below was subjected to a Trendsetter 3244VX manufactured by Creo (equipped with a water-cooled 40W infrared semiconductor laser (830 nm)) under the conditions of an output of 9 W, outer drum rotation speed of 210 rpm, resolution of 2, and 400 dpi. Image exposure was performed. Next, using each developer, in an automatic development processor having the structure shown in FIG. 2, a heater setting at which the plate surface temperature at the preheating portion becomes 100 ° C., and the immersion time (development time) in the developer is 20 seconds. Development processing was carried out at a conveying speed of However, when the developer 2 was used, it was washed with water before the post-development drying step.

  The obtained lithographic printing plate is attached to a printing machine SOR-M manufactured by Heidelberg, and fountain solution (EU-3 (etch solution manufactured by FUJIFILM Corporation) / water / isopropyl alcohol = 1/89/10 (volume ratio). )) And TRANS-G (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.), printing was performed at a printing speed of 6000 sheets per hour.

  Each lithographic printing plate precursor was evaluated in the same manner as in Example 1 for the coated surface, printing durability, stain resistance, stain resistance after aging, and developability. For evaluation of printing durability and developability, Examples 68 to 85 and Comparative Examples 11 to 15 are based on Comparative Example 13, and Examples 82 to 95 and Comparative Examples 16 to 20 are based on Comparative Example 18 ( 100). The results are shown in the table below.

As is apparent from the above table, the examples using the (A) specific high molecular compound and the (B) specific low molecular compound improve the coating surface condition, and improve the printing durability, stain resistance, and time. It was found to be excellent in stain resistance and developability.
On the other hand, even when (A) the specific high molecular compound is included in the undercoat layer, the coated surface shape is very deteriorated in Comparative Examples 13 and 18 where (B) the specific low molecular compound is not included, and the printing durability and stain resistance are deteriorated. It was found that the balance between stain resistance and developability after aging was poor.
Further, from Comparative Examples 12 and 17, when (A) the specific polymer compound does not have a hydrophilic group having a specific structure, (B) even when the specific low molecular compound is added, the coated surface state, printing durability, stain resistance, It was found that the effect of improving the stain resistance and developability after time could hardly be confirmed.
Further, in Comparative Examples 14 and 19 using the polymer compound E-2 for Comparative Example, which does not have a support adsorbing group and does not satisfy the requirements of (A) the specific polymer compound, the printing durability is greatly deteriorated. Was found to be confirmed.
Further, in Comparative Examples 15 and 20 using the polymer compound E-3 for Comparative Example, which has a molecular weight of less than 5000 and does not satisfy the requirements for (A) the specific polymer compound, in addition to the performance degradation due to the low molecular weight (B) The effect of adding the specific low molecular weight compound was hardly confirmed, and it was found that the performance balance of the coated surface state, printing durability, stain resistance, stain resistance after aging and developability was low.

[Exposure, development and printing]
Each lithographic printing plate precursor shown in the following table was exposed under the conditions of an external drum rotation speed of 1000 rpm, a laser output of 70%, and a resolution of 2400 dpi with a Luxel PLANETSETTER T-6000III equipped with an infrared semiconductor laser. The exposure image includes a solid image and a 50% dot chart of a 20 μm dot FM screen.
The exposed lithographic printing plate precursor was mounted on the 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 supplying on the machine with dampening water and ink using the standard automatic printing start method of LITHRONE 26, printing was performed on Tohishi Art (76.5 kg) paper at a printing speed of 10,000 sheets per hour.

[Evaluation]
Each lithographic printing plate precursor was evaluated for on-press developability and printing durability as follows. The coated surface, stain resistance, and stain resistance after aging were evaluated in the same manner as in Example 1. The results are shown in the table below.
<On-press developability>
The number of print sheets required until the on-press development of the non-image portion of the photosensitive layer on the printing press was completed and no ink was transferred to the non-image portion was measured as on-press developability.

<Print durability>
After the on-press development property was evaluated, printing was further continued. As the number of printed sheets increased, the photosensitive layer gradually worn out, and the ink density on the printed material decreased. The printing durability is evaluated by assuming that the number of printed copies is the number of printed copies when the dot area ratio of the 50% halftone dot on the printed matter is 5% lower than the measured value of the 100th printed sheet. did. Evaluation of printing durability was expressed in terms of relative printing durability as defined below for Examples 96 to 106 and Comparative Examples 21 to 25, with Comparative Example 23 as a reference (100). The larger the relative printing durability number, the higher the printing durability.
Relative printing durability = (printing durability of the target lithographic printing plate precursor) / (printing durability of the standard lithographic printing plate precursor)

As is apparent from the above table, the examples using the (A) specific high molecular compound and the (B) specific low molecular compound improve the coating surface condition, and improve the printing durability, stain resistance, and time. It was found to be excellent in stain resistance and developability.
On the other hand, even when (A) the specific high molecular compound is included in the undercoat layer, the coated surface state is very deteriorated in Comparative Example 23 where (B) the specific low molecular compound is not included, and the printing durability, stain resistance, It turned out that the balance of later stain resistance and developability is inferior.
Further, from Comparative Example 22, when (A) the specific polymer compound does not have a hydrophilic group having a specific structure, even when (B) the specific low molecular compound is added, the coated surface state, printing durability, stain resistance, after time It was found that almost no improvement effect was observed in the stain resistance and developability.
Further, in Comparative Example 24 using the polymer compound E-2 for Comparative Example, which does not have a support adsorbing group and does not satisfy the requirements of the specific polymer compound (A), significant deterioration in printing durability was confirmed. I found out that
Moreover, in the comparative example 25 using the high molecular compound E-3 for a comparative example whose molecular weight is less than 5000 and does not satisfy the requirements of (A) specific high molecular compound, in addition to the performance fall by low molecular weight, ( B) The effect of adding the specific low molecular weight compound was hardly confirmed, and it was found that the performance balance of the coated surface state, printing durability, stain resistance, stain resistance after aging and developability was low.

An undercoat layer coating solution having the following composition was applied to the aluminum support 1 with a bar coater and dried under the conditions shown in Table 10 to form an undercoat layer. The dry coating amount of the undercoat layer was 12 mg / m ² .

<Undercoat layer coating solution>
-The specific polymer compounds listed in the table below or the following polymer compounds for comparison
0.50g
・ Specific low molecular weight compounds listed in the table below or comparative low molecular weight compounds listed below
In the table, methanol 90.0g
・ Pure water 10.0g

[Formation of photosensitive layer]
The photosensitive layer coating solution 1 was bar coated on the undercoat layer and then oven dried at 90 ° C. for 60 seconds to form a photosensitive layer having a dry coating amount of 1.3 g / m ² .

(Formation of protective layer)
The protective layer coating solution 1 was applied using a bar so that the dry coating amount was 0.75 g / m ^2, and then dried at 125 ° C. for 70 seconds to form a protective layer.

  The coated surface of the prepared lithographic printing plate was evaluated in the same manner as in Example 1. The results are shown in Table 10.

  As can be seen from the above table, the lithographic printing plate precursor in which (b) the specific low molecular weight compound is added to (a) the specific high molecular compound, the coated surface condition may deteriorate even under higher speed coating conditions. It was found that productivity could be improved.

Claims (16)

A support, a photosensitive layer provided on the support, and an intermediate layer provided between the support and the photosensitive layer, wherein the intermediate layer (A) has a weight average molecular weight of 5000 or more. And (B) a component having a zwitterionic group and having a molecular weight of less than 5000,
The (A) copolymer is a repeating unit having at least one support adsorbing group having a structure represented by the following general formulas (a2-1) to (a2-6) in a side chain and (a3) a hydrophilic group possess the door, the hydrophilic group is a zwitterionic structure,
(B) A lithographic printing plate precursor wherein the component having a zwitterionic group and having a molecular weight of less than 5000 has at least one structure represented by the following general formulas (b1-1) to (b1-8) .
(In the general formulas (a2-1) to (a2-6), M ^{1 to} M ⁸ each represent a hydrogen atom, a metal atom contained in an alkali metal or an alkaline earth metal, or ammonium. R ^{41 to} R ^46, respectively, .Y ²¹ to Y ²⁶ represents a hydrogen atom or an alkyl group, respectively, a single bond, -CO -, - O -, - NH-, 2 divalent aliphatic group or a divalent aromatic Represents a divalent linking group selected from the group consisting of group groups or combinations thereof. * Represents a site linked to the main chain of the polymer compound.)
(In General Formula (b1-1), R represents a C 1-15 alkyl group having a substituent, which may be saturated or unsaturated, and may be linear, cyclic or branched,
In general formulas (b1-2) to (b1-8), R may have a hydrogen atom or a substituent, may be saturated or unsaturated, and may be linear, cyclic or branched, and has 1 to 15 carbon atoms. Represents an alkyl group of
In general formulas (b1-1) to (b1-8), L represents a divalent linking group, Q represents an n-valent linking group, n represents an integer of 2 or more, and A ⁻ has an anion. Represents a structure , and E ⁺ represents a structure having a cation. ) Wherein (A) copolymer comprises a repeating unit having at least one support-adsorbing group having a structure represented by the following general formula (a2-1) and (a2-2) in the side chain, to claim 1 The lithographic printing plate precursor described. (A) the copolymer comprises a repeating unit having at least one hydrophilic group having a structure represented by the following general formula (a3-1) ~ (a3-5) in the side chain, according to claim 1 or 2 The lithographic printing plate precursor described in 1.
(In General Formula (a3-1), R ³¹ and R ³² each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and R ³¹ and R ³² are linked to each other. , Which may form a ring structure, L ³¹ represents a linking group, A ⁻ represents a structure having an anion, Y ³ represents a single bond, —CO—, —O—, —NH—, 2 A divalent linking group selected from the group consisting of a valent aliphatic group, a divalent aromatic group, or a combination thereof, * represents a site linked to the main chain of the copolymer.)
(In the general formula (a3-2), L ³² represents a linking group, and E ⁺ represents a structure having a cation. Y ⁴ represents a single bond, —CO—, —O—, —NH—, divalent. A divalent linking group selected from the group consisting of an aliphatic group, a divalent aromatic group, or a combination thereof, * represents a site linked to the main chain of the copolymer.
(In General Formula (a3-3), Y ³ represents a single bond, —CO—, —O—, —NH—, a divalent aliphatic group, a divalent aromatic group, or a combination thereof. Represents a divalent linking group selected from the group consisting of: * represents a site linked to the main chain of the copolymer, M represents a hydrogen atom or a monovalent metal atom.)
(In General Formula (a3-4), R ³³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may be substituted. Y ³ represents a single bond, —CO—, —O—, — NH— represents a divalent linking group selected from the group consisting of a divalent aliphatic group, a divalent aromatic group, or a combination thereof, where * represents a site linked to the main chain of the copolymer. Represents.)
(In General Formula (a3-5), R ³³ represents a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms. Y ³ represents a single bond, —CO—, —O—, — NH— represents a divalent linking group selected from the group consisting of a divalent aliphatic group, a divalent aromatic group, or a combination thereof, where * represents a site linked to the main chain of the copolymer. A ⁻ represents a structure having an anion.) The lithographic printing plate precursor according to claim 3 , wherein the copolymer (A) comprises a repeating unit having at least one hydrophilic group having a structure represented by the following general formula (a3-1) in the side chain. The lithographic printing plate precursor as claimed in any one of claims 1 to 4 , wherein the (A) copolymer further has (a1) a crosslinkable group in the side chain. The lithographic printing plate precursor according to claim 5 , wherein the crosslinkable group is represented by any one of the following general formulas (i) to (iii).
(In General Formula (i), R ^{1 to} R ³ each represents a hydrogen atom or a monovalent organic group. X represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —, and R ¹² Represents a hydrogen atom or a monovalent organic group.)
(In General Formula (ii), R ^{4 to} R ⁸ each represent a hydrogen atom or a monovalent organic group. Y represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —, and R ¹² Represents a hydrogen atom or a monovalent organic group.)
(In general formula (iii), R ^{9 to} R ¹¹ each represent a hydrogen atom or a monovalent organic group. Z has an oxygen atom, a sulfur atom, —N (R ¹³ ) — or a substituent. R ¹³ represents a hydrogen atom or an alkyl group that may have a substituent. The lithographic printing plate precursor according to any one of Claims 1 to 6 , wherein the alkyl group as R in formulas (b1-1) to (b1-8) has 1 to 5 carbon atoms . The component (B) having a zwitterionic group and having a molecular weight of less than 5000 has at least one structure represented by the general formula (b1-1), (b1-2), (b1-5) or (b1-6) The lithographic printing plate precursor as claimed in any one of claims 1 to 7, having the above. The lithographic plate according to any one of claims 1 to 8 , wherein the (A) copolymer comprises a repeating unit represented by the following general formula (A2) and a repeating unit represented by the general formula (A3). A printing plate master.
(In the general formula (A2), R _a ′ to R _c ′ each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom. (A2) represents the above general formulas (a2-1) to ( It represents the structure represented by a2-6), and is linked to the carbon atom at the site represented by * in general formulas (a2-1) to (a2-6).
(In the general formula (A3), R ²⁰¹ ~R ^203, respectively, .G represents a hydrogen atom, an alkyl group or a halogen atom having 1 to 6 carbon atoms, the general formula (a3-1) ~ (a3-5) in represents any represented by structural formula (a3-1) at a site represented by ~ (a3-5) in the * linked to carbon atoms.)
(In General Formula (a3-1), R ³¹ and R ³² each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and R ³¹ and R ³² are linked to each other. , Which may form a ring structure, L ³¹ represents a linking group, A ⁻ represents a structure having an anion, Y ³ represents a single bond, —CO—, —O—, —NH—, 2 A divalent linking group selected from the group consisting of a valent aliphatic group, a divalent aromatic group, or a combination thereof, * represents a site linked to the main chain of the copolymer.)
(In the general formula (a3-2), L ³² represents a linking group, and E ⁺ represents a structure having a cation. Y ⁴ represents a single bond, —CO—, —O—, —NH—, divalent. A divalent linking group selected from the group consisting of an aliphatic group, a divalent aromatic group, or a combination thereof, * represents a site linked to the main chain of the copolymer.
(In General Formula (a3-3), Y ³ represents a single bond, —CO—, —O—, —NH—, a divalent aliphatic group, a divalent aromatic group, or a combination thereof. Represents a divalent linking group selected from the group consisting of: * represents a site linked to the main chain of the copolymer, M represents a hydrogen atom or a monovalent metal atom.)
(In General Formula (a3-4), R ³³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may be substituted. Y ³ represents a single bond, —CO—, —O—, — NH— represents a divalent linking group selected from the group consisting of a divalent aliphatic group, a divalent aromatic group, or a combination thereof, where * represents a site linked to the main chain of the copolymer. Represents.)
(In General Formula (a3-5), R ³³ represents a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms. Y ³ represents a single bond, —CO—, —O—, — NH— represents a divalent linking group selected from the group consisting of a divalent aliphatic group, a divalent aromatic group, or a combination thereof, where * represents a site linked to the main chain of the copolymer. A ⁻ represents a structure having an anion.) The lithographic printing plate precursor as claimed in any one of claims 1 to 9 , wherein the photosensitive layer comprises (C) a polymerization initiator, (D) a polymerizable compound, (E) a binder, and (F) a dye. The lithographic printing plate precursor according to claim 10 , wherein the (E) binder is at least one of a (meth) acrylic resin, a polyurethane resin, and a polyvinyl butyral resin. The lithographic printing plate precursor according to claim 10 or 11 , wherein the polymerizable compound (D) has a urethane structure. The lithographic printing plate precursor as claimed in any one of claims 1 to 1 2, a step of exposing imagewise,
A method for producing a lithographic printing plate, comprising a step of removing the exposed lithographic printing plate precursor in the presence of a developer having a pH of 2 to 14 in the non-exposed portion of the photosensitive layer. Forming a protective layer on the surface of the photosensitive layer opposite to the support;
The developing step further includes a step of removing the photosensitive layer in the non-exposed area and the protective layer at the same time in the presence of the developer containing a surfactant (but not including a washing step). The method for producing a lithographic printing plate according to claim 13 . Process for producing a lithographic printing plate according to claim 13 or 14 wherein the pH of the developing solution, characterized in that it comprises a step of controlling the 2.0 to 10.0. A step of exposing the lithographic printing plate precursor according to any one of claims 1 to 12 imagewise,
A method for producing a lithographic printing plate, comprising: supplying printing ink and fountain solution on a printing machine to remove the photosensitive layer in the non-exposed portion.