JP2007272134A - Negative lithographic printing original plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a negative lithographic printing original plate which is capable of laser writing, has high sensitivity and excellent printing durability, and suppresses omission of a photosensitive layer. <P>SOLUTION: The negative lithographic printing original plate is obtained by sequentially stacking a photosensitive layer containing a polymerization initiator, a polymerizable compound and a binder polymer and a protective layer on a substrate, wherein the photosensitive layer contains a first binder polymer comprising a repeating unit represented by formula (1) (wherein R<SP>1</SP>represents H or CH<SB>3</SB>; R<SP>2</SP>represents a linking group containing two or more atoms selected from C, H, O, N and S, in which the number of atoms is 2-82; A represents O or -NR<SP>3</SP>-, R<SP>3</SP>represents H or a 1-10C hydrocarbon group; and n represents 1-5) and a second binder polymer having a carboxyl group and a crosslinkable group in side chains and a polyurethane skeleton in a backbone. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a negative lithographic printing plate precursor capable of direct drawing with a laser beam.

  Conventionally, as a lithographic printing plate precursor, a PS plate having a configuration in which a lipophilic photosensitive resin layer is provided on a hydrophilic substrate has been widely used. As the plate making method, mask exposure (surface exposure) is usually performed through a lithographic film. After exposure), the desired printing plate was obtained by dissolving and removing the non-image area. In recent years, digitization techniques that electronically process, store, and output image information using a computer have become widespread. Various new image output methods corresponding to such digitization techniques have come into practical use. As a result, computer-to-plate (CTP) technology that scans highly directional light such as laser light according to digitized image information and directly produces a printing plate without going through a lithographic film is desired. Obtaining a lithographic printing plate precursor adapted to this is an important technical issue.

As a negative lithographic printing plate precursor capable of scanning exposure, a photopolymerization initiator, an addition-polymerizable ethylenically unsaturated compound, and a repeating unit having a specific structure soluble in an alkali developer are provided on a hydrophilic substrate. There has been proposed a photopolymerization type photosensitive layer containing a binder polymer having a binder polymer and an oxygen-blocking protective layer provided as necessary (see, for example, Patent Document 1).
Further, for the purpose of improving productivity in the plate making process, a negative lithographic printing plate provided with a photopolymerization type photosensitive layer and an oxygen-blocking protective layer to which an inorganic layered compound is added on a hydrophilic substrate. An original version has also been proposed (see, for example, Patent Document 2).
JP 2004-318053 A JP 11-38633 A

However, it has been found by a detailed study by the present inventors that a negative lithographic printing plate precursor sometimes has a phenomenon that the photosensitive layer is lost during the production process or long-term storage.
Here, “missing” is a phenomenon in which when the photosensitive layer is exposed and developed, a portion that is not completely cured and is removed is generated in the image portion.
The occurrence of the above-mentioned omission may not be effectively suppressed even by forming a protective layer.

  Therefore, the present invention solves the above-mentioned conventional drawbacks, that is, negative lithographic printing that can write with a laser and perform high-speed drawing, has high sensitivity and excellent printing durability, and suppresses the removal of the photosensitive layer. The purpose is to provide the original edition.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventor newly found out that the above object can be achieved by using at least two kinds of specific binder polymers in the photosensitive layer. It came.

  That is, the negative lithographic printing plate precursor according to the present invention is obtained by sequentially laminating a photosensitive layer containing a polymerization initiator, a polymerizable compound and a binder polymer on a substrate, and a protective layer. At least a first binder polymer containing a repeating unit represented by formula (I) and a second binder polymer having a carboxyl group and a crosslinkable group in the side chain and a polyurethane skeleton in the main chain It is characterized by doing.

(In General Formula (I), R ¹ represents a hydrogen atom or a methyl group, and R ² contains two or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. And A represents an oxygen atom or —NR ³ —, and R ³ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. N represents an integer of 1 to 5.)

In addition, it is preferable that the said protective layer contains an inorganic stratiform compound.
Moreover, it is preferable that the said photosensitive layer contains an infrared absorber from the viewpoint of the high sensitivity with an infrared laser, or the drawing aptitude.
In addition, from the viewpoint of increasing sensitivity, the first binder polymer preferably further includes a repeating unit having a crosslinkable group in the side chain. The crosslinkable group that the first binder polymer has in the side chain is more preferably at least one selected from the group consisting of a (meth) acryl group, an allyl group, and a styryl group.
The crosslinkable group of the second binder polymer is more preferably at least one selected from the group consisting of a (meth) acryl group and an allyl group.
Furthermore, the second binder polymer is preferably a binder polymer synthesized by polyaddition reaction of a diol compound having at least one carboxyl group and at least one diisocyanate compound.

  Here, “sequentially laminate” means that a photosensitive layer and a protective layer are provided in this order on a substrate, and an arbitrary layer other than these, such as an intermediate layer and a backcoat layer, provided according to the purpose. The existence of is not denied.

  The mechanism of occurrence of missing of the photosensitive layer described in the above problem is not clear, but it is probably a phenomenon caused by the long chain structure of the side chain of the binder polymer when a binder polymer with high mobility is used. I guess that.

Therefore, the effect | action in this invention is estimated as follows.
In the present invention, as described above, by using the first binder polymer having high mobility, the solubility discrimination between the image area and the non-image area at the time of development processing is widened, and good image forming ability is achieved. Is obtained. Furthermore, by using a second binder polymer with low motility and a specific structure, negative lithographic printing that effectively suppresses the removal of the photosensitive layer while maintaining good sensitivity and printing durability. You can provide the original version.

  Further, in order not only to suppress the removal of the photosensitive layer but also to better exhibit the performance as a lithographic printing plate such as sensitivity to an infrared laser and image forming ability, in particular, the composition of the photosensitive layer, particularly the infrared absorber. It has been found that addition, introduction of a crosslinkable group into the side chain of the second binder polymer (and the first binder polymer, if necessary), the blending balance between the binder polymer and the polymerizable compound, etc. also serve as important factors. It was. Furthermore, by adding an inorganic layered compound to the protective layer, in addition to the performance of suppressing the above-mentioned removal of the photosensitive layer and being highly sensitive to laser and excellent in image forming ability, further, a plate-making process without interleaf It has been found that it is possible to provide added value for the purpose of improving productivity.

  According to the present invention, there is provided a negative lithographic printing plate precursor capable of direct drawing by a laser, having high sensitivity, excellent image forming ability, good printing durability, and effectively suppressing loss of a photosensitive layer. can do.

Embodiments of the present invention will be described below.
The negative lithographic printing plate precursor of the present invention is a negative lithographic printing plate precursor obtained by sequentially laminating a photosensitive layer containing a polymerization initiator, a polymerizable compound and a binder polymer, and a protective layer on a substrate, The photosensitive layer includes a first binder polymer containing a repeating unit represented by the following general formula (I), and a second binder having a carboxyl group and a crosslinkable group in the side chain and a polyurethane skeleton in the main chain. And at least a polymer.

(In General Formula (I), R ¹ represents a hydrogen atom or a methyl group, and R ² contains two or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. And A represents an oxygen atom or —NR ³ —, and R ³ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. N represents an integer of 1 to 5.)

<Photosensitive layer>
First, in describing the photosensitive layer in the present invention, each component used in the photosensitive layer will be described in detail.

(First binder polymer)
The first binder polymer contained in the photosensitive layer has a repeating unit represented by the general formula (I).

R ¹ in the general formula (I) represents a hydrogen atom or a methyl group, and a methyl group is particularly preferable.

The linking group represented by R ² in the general formula (I) includes two or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. The number of atoms is 2 to 82, preferably 2 to 50, and more preferably 2 to 30. The linking group represented by R ² may have a substituent. The total number of atoms shown here refers to the number of atoms including the substituent when the linking group has a substituent. More specifically, the number of atoms constituting the main skeleton of the linking group represented by R ² is preferably 1-30, more preferably 3-25, and 4-20. More preferred is 5-10. The “main skeleton of the linking group” in the present invention refers to an atom or an atomic group used only for linking A and the terminal COOH in the general formula (I), and particularly when there are a plurality of linking paths. Refers to an atom or atomic group that constitutes a path with the least number of atoms used. Therefore, when a linking group has a ring structure, the number of atoms to be included differs depending on the linking site (for example, o-, m-, p-, etc.).

More specifically, as the linking group represented by R ² in the general formula (I), alkylene, substituted alkylene, arylene, substituted arylene, or a hydrogen atom on any carbon atom constituting these groups is excluded ( n + 1) -valent groups are exemplified, and those having a structure in which a plurality of these groups are linked by an amide bond or an ester bond are preferred.
Examples of the linking group having a chain structure include ethylene and propylene. Further, a structure in which these alkylenes are linked through an ester bond is particularly preferable.

Among these, the linking group represented by R ² in the general formula (I) is preferably an (n + 1) -valent hydrocarbon group having an aliphatic cyclic structure having 3 to 30 carbon atoms. More specifically, a compound having an aliphatic cyclic structure such as cyclopropane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, dicyclohexyl, tercyclohexyl, norbornane and the like, which may be substituted by one or more arbitrary substituents And (n + 1) valent hydrocarbon groups by removing (n + 1) hydrogen atoms on an arbitrary carbon atom constituting. R ² preferably has 3 to 30 carbon atoms including a substituent.

One or more arbitrary carbon atoms of the compound constituting the aliphatic cyclic structure may be replaced with a heteroatom selected from a nitrogen atom, an oxygen atom, or a sulfur atom. In terms of printing durability, R ² represents a condensed polycyclic aliphatic hydrocarbon, a bridged cyclic aliphatic hydrocarbon, a spiro aliphatic hydrocarbon, an aliphatic hydrocarbon ring assembly (a plurality of rings are connected by a bond or a linking group). A (n + 1) valent hydrocarbon group having an aliphatic cyclic structure which may have a substituent of 5 to 30 carbon atoms containing two or more rings. . Also in this case, the carbon number includes the carbon atom of the substituent.

As the linking group represented by R ² , those having 5 to 10 atoms constituting the main skeleton of the linking group are particularly preferred, and are structurally a chain structure, and an ester bond in the structure. And those having a cyclic structure as described above are preferred.

Examples of the substituent that can be introduced into the linking group represented by R ² include monovalent nonmetallic atomic groups other than hydrogen, such as halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups. Group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N- Diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy , Arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-aryl Ureido group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N-alkylureido group, N ′ -Alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, N'-aryl-N-alkylureido group, N ' -Aryl-N-arylureido group, N ', N'-diaryl-N-alkylureido group, N', N'-diaryl-N-arylureido group, N'-al Kill-N′-aryl-N-alkylureido group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group and its conjugate base group, Alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, Alkylsulfinyl group An arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfo group (-SO ₃ H) and its conjugated base group, alkoxy sulfonyl group, aryloxy sulfonyl group, sulfinamoyl group, N- alkylsulfinamoyl group, N, N- Dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N -Dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, N-acylsulfamoyl group and its conjugate base group, N- alkylsulfonylsulfamoyl group (-SO ₂ NHSO ₂ alkyl)) and its conjugated base group, N- aryl sulfonylsulfamoyl group _{(-SO 2 NHSO 2 (aryl)} ) and its conjugated base group, N- alkylsulfonylcarbamoyl group (-CONHSO ₂ (alkyl)) and its conjugate Base group, N-arylsulfonylcarbamoyl group (—CONHSO ₂ (aryl)) and its conjugate base group, alkoxysilyl group (—SI (Oalkyl) ₃ ), aryloxysilyl group (—SI (Oaryl) ₃ ), hydroxysilyl Group (—SI (OH) ₃ ) and its conjugate base group, phosphono group (—PO ₃ H ₂ ) and its conjugate base group, dialkylphosphono group (—PO ₃ (alkyl) ₂ ), diarylphosphono group (— PO ₃ (aryl) _2), alkyl aryl phosphono group _{(-PO 3 (alkyl) (aryl} )) , Monoalkylphosphono group (—PO ₃ H (alkyl)) and its conjugate base group, monoarylphosphono group (—PO ₃ H (aryl)) and its conjugate base group, phosphonooxy group (—OPO ₃ H ₂ ) And its conjugate base group, dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), diarylphosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylarylphosphonooxy group (—OPO ₃ (alkyl) ( aryl)), monoalkylphosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group, monoarylphosphonooxy group (—OPO ₃ H (aryl)) and its conjugate base group, cyano group, nitro group, group, ₍₂ -B (alkyl)) dialkyl boryl group, Jiariruboriru group (-B (aryl) _2), alkyl aryl boryl -B (alkyl) (aryl)) , dihydroxy boryl group (-B (OH) ₂₎ and its conjugated base group, an alkyl hydroxy boryl group (-B (alkyl) (OH) ) and its conjugated base group, an aryl hydroxy boryl And the group (—B (aryl) (OH)) and its conjugate base group, aryl group, alkenyl group and alkynyl group.

  In the lithographic printing plate precursor according to the invention, although depending on the design of the photosensitive layer, a substituent having a hydrogen atom capable of hydrogen bonding, particularly a substituent having an acid dissociation constant (pKa) smaller than that of a carboxylic acid is , Because it tends to lower the printing durability. On the other hand, hydrophobic substituents such as halogen atoms, hydrocarbon groups (alkyl groups, aryl groups, alkenyl groups, alkynyl groups), alkoxy groups, aryloxy groups and the like are more preferable because they tend to improve printing durability. When the cyclic structure is a monocyclic aliphatic hydrocarbon having 6 or less members such as cyclopentane or cyclohexane, it preferably has such a hydrophobic substituent. If possible, these substituents may be bonded to each other or with a substituted hydrocarbon group to form a ring, and the substituent may be further substituted.

When A in the general formula (I) is —NR ³ —, R ³ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ³ include an alkyl group, an aryl group, an alkenyl group, and an alkynyl group.
Specific examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, isopropyl group, isobutyl group, sec-butyl group, 1 carbon number such as tert-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclopentyl group, cyclohexyl group, 1-adamantyl group, 2-norbornyl group Up to 10 linear, branched or cyclic alkyl groups.
Specific examples of the aryl group include a phenyl group, a naphthyl group, and an indenyl group. Further, a heteroaryl group having up to 10 carbon atoms containing one heteroatom selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom can also be used. Specifically, for example, a furyl group, a thienyl group, A pyrrolyl group, a pyridyl group, a quinolyl group, etc. are mentioned.
Specific examples of the alkenyl group include those having 2 to 10 carbon atoms such as vinyl group, 1-propenyl group, 1-butenyl group, 1-methyl-1-propenyl group, 1-cyclopentenyl group, 1-cyclohexenyl group and the like. A linear, branched, or cyclic alkenyl group is mentioned.
Specific examples of the alkynyl group include alkynyl groups having 2 to 10 carbon atoms such as ethynyl group, 1-propynyl group, 1-butynyl group, and 1-octynyl group.
Here, the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ³ may further have a substituent, and examples of the substituent that can be introduced include the substituent that R ² can introduce. Same as listed. However, the carbon number of R < ³ > is 1-10 including the carbon number of a substituent.

  A in the general formula (I) is preferably an oxygen atom or —NH— because synthesis is easy.

  N in the general formula (I) represents an integer of 1 to 5, and is preferably 1 in terms of printing durability.

  Although the preferable specific example of the repeating unit represented by general formula (I) is shown below, it is not specifically limited to these.

  One type of repeating unit represented by the general formula (I) may be contained in the first binder polymer, or two or more types may be contained. The first binder polymer may be a polymer composed of only the repeating unit represented by the general formula (I), but is usually used as a copolymer in combination with other repeating units. The total content of the repeating unit represented by the general formula (I) in the copolymer is appropriately determined depending on the structure, the design of the photosensitive layer, and the like, but preferably 1 to 99 mol relative to the total molar amount of the copolymer component. % Is preferable, more preferably 5 to 40 mol%, still more preferably 5 to 20 mol%.

As other repeating units when used as a copolymer, conventionally known ones can be used without limitation as long as they are radically polymerizable monomers. Specific examples include monomers described in “Polymer Data Handbook—Basic Edition” (Edition of Polymer Society, Bafukan, 1986). Such other repeating units may be of one type or may be used in combination of two or more types.
In addition, as another repeating unit when using as said copolymer, the repeating unit which has a crosslinkable group in a side chain, and the repeating unit which has an amide group in a side chain are used preferably.

-Repeating unit having a crosslinkable group in the side chain-
Here, the crosslinkable group is a group that crosslinks the polymer binder in the process of 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, an onium salt structure etc. are mentioned, for example. By using a copolymer having a repeating unit having a crosslinkable group in the side chain together with the repeating unit represented by the general formula (I), the performance as a lithographic printing plate such as sensitivity to an infrared laser and image forming ability is further improved. It can be exhibited well.

  Although it does not specifically limit as a preferable crosslinkable group in the repeating unit which has the said crosslinkable group, The structure represented by the following general formula (A)-(C) is mentioned.

(In the general formulas (A) to (C), R ^{4 to} R ¹⁴ each independently represents a hydrogen atom or a monovalent substituent. X and Y each independently represent an oxygen atom, a sulfur atom, Or represents an organic group containing at least a group selected from the group consisting of —N—R ¹⁵ , and Z represents a group selected from the group consisting of an oxygen atom, a sulfur atom, —N—R ¹⁵ , or a phenylene group. Represents at least an organic group contained therein, wherein R ¹⁵ represents a hydrogen atom or a monovalent organic group.)

In the general formula (A), R ^{4 to} R ⁶ each independently represent a hydrogen atom or a monovalent substituent, and R ⁴ is a hydrogen atom or an alkyl group which may have a substituent. An organic group such as a hydrogen atom, a methyl group, a methylalkoxy group, or a methyl ester group is more preferable. R ⁵ and R ⁶ may each independently have a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, or a substituent. Alkyl group, aryl group which may have a substituent, alkoxy group which may have a substituent, aryloxy group which may have a substituent, alkylamino group which may have a substituent, substituted An arylamino group which may have a group, an alkylsulfonyl group which may have a substituent, and an arylsulfonyl group which may have a substituent are preferable, among which a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, a substituent An alkyl group which may have a group and an aryl group which may have a substituent are more preferable.
Here, examples of the substituent that can be introduced into these groups include a methoxycarbonyl group, an ethoxycarbonyl group, an isopropyloxycarbonyl group, a methyl group, an ethyl group, and a phenyl group.
X represents an oxygen atom, a sulfur atom or -N-R ¹⁵ organic group containing at least a group selected from the group consisting of,, that even an oxygen atom, a sulfur atom or -N-R ^15, More preferred. R ¹⁵ is preferably an alkyl group which may have a substituent.

In the general formula (B), R ^{7 to} R ¹¹ each independently represents a hydrogen atom or a monovalent substituent, and specifically, for example, a hydrogen atom, a halogen atom, an amino group, a dialkylamino group A carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, Aryloxy group which may have a substituent, alkylamino group which may have a substituent, arylamino group which may have a substituent, alkylsulfonyl group which may have a substituent, substituent An arylsulfonyl group which may have a hydrogen atom, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, an alkyl group which may have a substituent, and an aryl group which may have a substituent are more preferable. Masui.
Here, as a substituent which can be introduced into these groups, those exemplified as the substituent which can be introduced in the general formula (A) are exemplified.
Y represents an oxygen atom, a sulfur atom or -N-R ¹⁵ organic group containing at least a group selected from the group consisting of,, that even an oxygen atom, a sulfur atom or -N-R ^15, More preferred. R ¹⁵ is preferably the same as that in general formula (A).

In the general formula (C), R ^{12 to} R ¹⁴ each independently represents a hydrogen atom or a monovalent substituent. Specific examples thereof include a hydrogen atom, a halogen atom, an amino group, and a dialkylamino group. A carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, Aryloxy group which may have a substituent, alkylamino group which may have a substituent, arylamino group which may have a substituent, alkylsulfonyl group which may have a substituent, substituent An arylsulfonyl group which may have a hydrogen atom, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, an alkyl group which may have a substituent, and an aryl group which may have a substituent are more preferable. preferable.
Here, as a substituent which can be introduced into these groups, those exemplified as the substituent which can be introduced in the general formula (A) are exemplified.
Z represents an organic group containing at least a group selected from the group consisting of an oxygen atom, a sulfur atom, —N—R ¹⁵ or a phenylene group, and further represents an oxygen atom, a sulfur atom, —N—R ¹⁵ or a phenylene group. It is more preferable that R ¹⁵ is preferably the same as that in general formula (A).

Among these crosslinkable groups, α-substituted methylacrylic group [—OC (═O) —C (—CH ₂ Z) ═CH ₂ , Z = hydrocarbon group starting from heteroatom], (meth) acrylic group, An ethylenically unsaturated bond group such as an allyl group or a styryl group is preferred, and a (meth) acryl group, an allyl group or a styryl group is particularly preferred.
Specific preferred examples of the repeating unit having a crosslinkable group in the side chain of the structure represented by the general formulas (A) to (C) are shown below, but are not limited thereto.

-Repeating unit having an amide group in the side chain-
Next, a repeating unit having an amide group in the side chain, which is preferable as another repeating unit when used as a copolymer, will be described. Use of a copolymer having a repeating unit having an amide group in the side chain together with the repeating unit represented by the general formula (I) is preferable from the viewpoint of improving the film property.
Such an amide group is preferably an amide group having a structure represented by the following general formula (F).

(In the general formula (F), R ¹⁸ and R ¹⁹ are each independently a hydrogen atom, each of which may have a substituent, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, Alternatively, it represents a substituted sulfonyl group, and R ¹⁸ and R ¹⁹ may be bonded to each other to form a ring.)

Preferable examples of R ¹⁸ and R ¹⁹ will be described in detail. Examples of the alkyl group represented by R ¹⁸ and R ¹⁹ include linear, branched, and cyclic alkyl groups having 1 to 20 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, and an ethyl group. Group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group, octadecyl group, eicosyl group, isopropyl group, isobutyl group, Examples thereof include s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group and 2-norbornyl group. . Of these, linear alkyl groups having 1 to 12 carbon atoms, branched alkyl groups having 3 to 12 carbon atoms, and cyclic alkyl groups having 5 to 10 carbon atoms are more preferable.

Examples of the substituent of the substituted alkyl group represented by R ¹⁸ and R ¹⁹ include a group composed of a monovalent non-metallic atomic group excluding a hydrogen atom. Preferred examples include halogen atoms (—F, —Br, -Cl, -I), hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkyl Carbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarba Ileoxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkyl Ureido group, N′-arylureido group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N -Alkylureido group, N'-alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, N'-aryl-N -Alkylureido group, N'-aryl-N-arylureido group, N ', N'-diaryl-N-alkylureido group, N', N'-diaryl -N-arylureido group, N'-alkyl-N'-aryl-N-alkylureido group, N'-alkyl-N'-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl Group (R ⁰¹ CO—), carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group N-alkyl-N-arylcarba Yl group, alkylsulfinyl group, arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, (referred to as a sulfonato group) sulfo group (-SO ₃ H) and its conjugated base group, alkoxy sulfonyl group, aryloxy sulfonyl group, sulfinamoyl group N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, Sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group , A phosphono group (—PO ₃ H ₂ ) and its conjugate base group ( Phosphonate group), a dialkylphosphono group (—PO ₃ (alkyl) ₂ ; alkyl = alkyl group, hereinafter the same), a diarylphosphono group (—PO ₃ (aryl) ₂ ; aryl = aryl group, the same hereinafter), Alkylarylphosphono group (—PO ₃ (alkyl) (aryl)), monoalkylphosphono group (—PO ₃ H (alkyl)) and its conjugate base group (referred to as alkylphosphonato group), monoarylphosphono group (—PO ₃ H (aryl)) and its conjugated base group (referred to as arylphosphonate group), phosphonooxy group (—OPO ₃ H ₂ ) and its conjugated base group (referred to as phosphonatoxy group), dialkylphosphonooxy group ( -OPO ₃ (alkyl) _2), diaryl phosphono group _{(-OPO 3 (aryl) 2)} , alkylaryl ho Honookishi group _{(-OPO 3 (alkyl) (aryl} )), ( referred to as alkylphosphonato group) monoalkyl phosphono group (-OPO ₃ H (alkyl)) and its conjugated base group, monoarylphosphono group (—OPO ₃ H (aryl)) and its conjugate base group (referred to as arylphosphonatoxy group), cyano group, nitro group, aryl group, alkenyl group, alkynyl group, heterocyclic group, silyl group and the like.

Specific examples of the alkyl group in these substituents include those similar to the alkyl group represented by R ¹⁸ and R ¹⁹ , and specific examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. , Tolyl group, xylyl group, mesityl group, cumenyl group, chlorophenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group , Methylthiophenyl group, phenylthiophenyl group, methylaminophenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenyl Luba carbamoylphenyl group, cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl group, and a phosphate Hona preparative phenyl group.

Examples of the alkenyl group in these substituents include vinyl group, 1-propenyl group, 1-butenyl group, cinnamyl group, 2-chloro-1-ethenyl group, and the like. Examples of alkynyl groups Includes an ethynyl group, a 1-propynyl group, a 1-butynyl group, a trimethylsilylethynyl group, and the like.
Furthermore, In the substituents, R ⁰¹ in the acyl group (R ⁰¹ CO-), a hydrogen atom, and the above-described alkyl group, and an aryl group.

  Among these substituents, more preferred are halogen atoms (—F, —Br, —Cl, —I), alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, N-alkylamino groups, N, N -Dialkylamino group, acyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, acylamino group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group Group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, sulfo group, sulfonate group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfa group Moyl group, N-arylsulfur Amoyl group, N-alkyl-N-arylsulfamoyl group, phosphono group, phosphonato group, dialkylphosphono group, diarylphosphono group, monoalkylphosphono group, alkylphosphonato group, monoarylphosphono group, arylphospho Examples thereof include a nato group, a phosphonooxy group, a phosphonatooxy group, an aryl group, and an alkenyl group. In addition, examples of the heterocyclic group include a pyridyl group and a piperidinyl group. Examples of the silyl group include a trimethylsilyl group.

  On the other hand, the alkylene group constituting the substituted alkyl group includes a divalent organic residue obtained by removing any one of the hydrogen atoms on the alkyl group having 1 to 20 carbon atoms. Preferred examples include linear alkylene groups having 1 to 12 carbon atoms, branched alkylene groups having 3 to 12 carbon atoms, and cyclic alkylene groups having 5 to 10 carbon atoms. Preferable specific examples of the substituted alkyl group obtained by combining such an alkylene group and a substituent include chloromethyl group, bromomethyl group, 2-chloroethyl group, trifluoromethyl group, methoxymethyl group, isopropoxymethyl. Group, butoxymethyl group, s-butoxybutyl group, methoxyethoxyethyl group, allyloxymethyl group, phenoxymethyl group, methylthiomethyl group, tolylthiomethyl group, pyridylmethyl group, tetramethylpiperidinylmethyl group, N-acetyl Tetramethylpiperidinylmethyl group, trimethylsilylmethyl group, methoxyethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N-cyclohexylcarbamoyloxye Group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycarbonylethyl group, allyloxycarbonylbutyl group, Chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- (sulfophenyl) carbamoylmethyl group , Sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N-methyl-N- (phosphono Enyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl group, tolylphosphonohexyl group, tolylphosphonatohexyl Group, phosphonooxypropyl group, phosphonatoxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl group, 1- Examples thereof include a propenylmethyl group, a 2-butenyl group, a 2-methylallyl group, a 2-methylpropenylmethyl group, a 2-propynyl group, a 2-butynyl group, and a 3-butynyl group.

Next, the aryl group represented by R ¹⁸ and R ¹⁹ includes one consisting of one benzene ring, two or three benzene rings forming a condensed ring, benzene ring and five-membered unsaturated ring. Examples of the condensed ring can be mentioned, and specific examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthenyl group, and a fluorenyl group. Among these, a phenyl group A naphthyl group is more preferable.

Examples of the substituted aryl group represented by R ¹⁸ and R ¹⁹ include those having a group consisting of a monovalent nonmetallic atomic group excluding a hydrogen atom as a substituent on the ring-forming carbon atom of the aryl group. It is done. Examples of preferred substituents include the aforementioned alkyl groups, substituted alkyl groups, and those previously shown as substituents in the substituted alkyl group. Preferred examples of such a substituted aryl group include biphenyl group, tolyl group, xylyl group, mesityl group, cumenyl group, chlorophenyl group, bromophenyl group, fluorophenyl group, chloromethylphenyl group, trifluoromethylphenyl group. Hydroxyphenyl group, methoxyphenyl group, methoxyethoxyphenyl group, allyloxyphenyl group, phenoxyphenyl group, methylthiophenyl group, tolylthiophenyl group, ethylaminophenyl group, diethylaminophenyl group, morpholinophenyl group, acetyloxyphenyl group, Benzoyloxyphenyl group, N-cyclohexylcarbamoyloxyphenyl group, N-phenylcarbamoyloxyphenyl group, acetylaminophenyl group, N-methylbenzoylaminophenyl group, cal Xiphenyl group, methoxycarbonylphenyl group, allyloxycarbonylphenyl group, chlorophenoxycarbonylphenyl group, carbamoylphenyl group, N-methylcarbamoylphenyl group, N, N-dipropylcarbamoylphenyl group, N- (methoxyphenyl) carbamoylphenyl group N-methyl-N- (sulfophenyl) carbamoylphenyl group, sulfophenyl group, sulfonatophenyl group, sulfamoylphenyl group, N-ethylsulfamoylphenyl group, N, N-dipropylsulfamoylphenyl group, N-tolylsulfamoylphenyl group, N-methyl-N- (phosphonophenyl) sulfamoylphenyl group, phosphonophenyl group, phosphonatophenyl group, diethylphosphonophenyl group, diphenylphosphonophenyl Methylphosphonophenyl group, methylphosphonatophenyl group, tolylphosphonophenyl group, tolylphosphonophenyl group, allylphenyl group, 1-propenylmethylphenyl group, 2-butenylphenyl group, 2-methylallylphenyl group, A 2-methylpropenylphenyl group, a 2-propynylphenyl group, a 2-butynylphenyl group, a 3-butynylphenyl group, and the like can be given.

An alkenyl group, a substituted alkenyl group, an alkynyl group, and a substituted alkynyl group (—C (R ⁰² ) ═C (R ⁰³ ) (R ⁰⁴ ) represented by R ¹⁸ and R ¹⁹ , and —C≡C (R ^{05 Examples of} )) include those in which R ⁰² , R ⁰³ , R ⁰⁴ and R ⁰⁵ are monovalent non-metallic atomic groups. Preferable examples of R ⁰² , R ⁰³ , R ⁰⁴ and R ⁰⁵ include a hydrogen atom, a halogen atom, an alkyl group, a substituted alkyl group, an aryl group and a substituted aryl group. Specific examples thereof include those shown as the above examples. More preferable groups of R ⁰² , R ⁰³ , R ⁰⁴ , and R ⁰⁵ include a hydrogen atom, a halogen atom, and a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. Preferable specific examples of the alkenyl group, substituted alkenyl group, alkynyl group and substituted alkynyl group represented by R ¹⁸ and R ¹⁹ include a vinyl group, 1-propenyl group, 1-butenyl group, 1-pentenyl group, 1-hexenyl group, 1-octenyl group, 1-methyl-1-propenyl group, 2-methyl-1-propenyl group, 2-methyl-1-butenyl group, 2-phenyl-1-ethenyl group, 2-chloro- Examples include 1-ethenyl group, ethynyl group, 1-propynyl group, 1-butynyl group, and phenylethynyl group.

Examples of the heterocyclic group represented by R ¹⁸ and R ¹⁹ include the pyridyl group exemplified as the substituent of the substituted alkyl group.

^{Examples of the} substituted sulfonyl group (R ⁰¹¹ —SO ₂ —) represented by R ¹⁸ and R ¹⁹ include those in which R ⁰¹¹ is a group consisting of a monovalent nonmetallic atomic group. More preferable examples include an alkylsulfonyl group and an arylsulfonyl group. Examples of the alkyl group and aryl group in these include those described above as the alkyl group, substituted alkyl group, aryl group, and substituted aryl group. Specific examples of such a substituted sulfonyl group include a butylsulfonyl group, a phenylsulfonyl group, a chlorophenylsulfonyl group, and the like.

In addition, examples of the ring formed by combining R ¹⁸ and R ¹⁹ in the general formula (F) include morpholine, piperazine, pyrrolidine, pyrrole, indoline and the like. These may be further substituted with a substituent as described above. Among them, the case where an alicyclic ring is formed is preferable.

In the general formula (F), R ¹⁸ and R ¹⁹ are preferably an alkyl group, an alkenyl group, an aryl group, or a substituted sulfonyl group. It is also preferred when R ¹⁸ and R ¹⁹ form an alicyclic ring.

  Specific examples preferable as the monomer or repeating unit having an amide group having a structure represented by the general formula (F) are shown below, but the invention is not limited thereto.

The first binder polymer used for the photosensitive layer in the lithographic printing plate precursor according to the invention includes the repeating unit represented by the general formula (I) and the above-described repeating unit having a crosslinkable group in the side chain. More preferably, it is a copolymer, and further, the repeating unit represented by the general formula (I), the above-described repeating unit having a crosslinkable group in the side chain, and the repeating unit having an amide group in the side chain; Particularly preferred is a copolymer comprising three repeating units. In the case of a copolymer composed of three repeating units, the preferred content of each repeating unit relative to the total molar amount of the copolymer component is the repeating unit represented by the general formula (I) as described above. It is -99 mol%, More preferably, it is 5-40 mol%, Most preferably, it is 5-20 mol%. Moreover, it is preferable that the repeating unit which has a crosslinkable group in a side chain is 0.5-98 mol%, More preferably, it is 20-98 mol%, Most preferably, it is 40-90 mol%. Moreover, it is preferable that the repeating unit which has an amide group in a side chain is 0.5-70 mol%, More preferably, it is 5-70 mol%, Most preferably, it is 15-40 mol%.
Hereinafter, although the preferable specific example of a 1st binder polymer is shown, it is not limited to these.

  The molecular weight of the first binder polymer is appropriately determined from the viewpoints of image formability and printing durability. Usually, when the molecular weight increases, the printing durability is excellent, but the image formability tends to deteriorate. On the other hand, when it is low, the image formability is improved, but the printing durability tends to be lowered. The molecular weight is preferably in the range of 2,000 to 1,000,000, more preferably 5,000 to 500,000, and still more preferably 10,000 to 300,000.

  The content of the crosslinkable group in the first binder polymer (content of unsaturated double bond capable of radical polymerization by iodometric titration) is preferably 0.1 per gram of the binder polymer from the viewpoint of sensitivity and storage stability. It is 1-10.0 mmol, More preferably, it is 1.0-8.0 mmol, Most preferably, it is 2.0-7.0 mmol.

  Further, the content of alkali-soluble groups in the first binder polymer (acid value by neutralization titration) is preferably 0.1 to 3.0 mmol per 1 g of the first binder polymer from the viewpoint of developability and printing durability. More preferably, it is 0.2-2.0 mmol, Most preferably, it is 0.3-1.5 mmol.

  In addition, the glass transition point (Tg) of the first binder polymer is preferably 70 to 300 ° C, more preferably 80 to 250 ° C, and most preferably 90 to 200 ° C, from the viewpoint of storage stability and sensitivity. It is a range.

(Second binder polymer)
The second binder polymer contained in the photosensitive layer in the lithographic printing plate precursor according to the invention is a binder polymer having a carboxyl group and a crosslinkable group in the side chain and a polyurethane skeleton in the main chain, It does not contain the repeating unit represented by I). By using the second binder polymer in combination with the first binder polymer as an essential component in the photosensitive layer, suppression of the removal of the photosensitive layer, higher sensitivity and improvement of the film strength of the image area, film characteristics and developability Improvement can be realized.

Further, as the second binder polymer, those having a crosslinkable group at the polymer terminal and / or main chain are more preferably used. By doing in this way, crosslinking reactivity improves further and photocured material intensity | strength increases. As a result, a lithographic printing plate having excellent printing durability can be provided.
Hereinafter, the second binder polymer will be described in detail.

First, the polyurethane basic skeleton of the second binder polymer can be obtained, for example, by polyaddition reaction of (i) at least one diisocyanate compound and (ii) a diol compound having at least one carboxyl group. In order to impart crosslinkability to the second binder polymer, a crosslinkable group such as an ethylenically unsaturated bond may be introduced into the main chain or side chain of the polymer. The crosslinkable group may be introduced by copolymerization or may be introduced by a polymer reaction.
What is preferable as the crosslinkable group is the same as the crosslinkable group described in the section “Repeating unit having a crosslinkable group in the side chain” of the first binder polymer, and the general formula (A) (B ) A functional group represented by (C) is preferred. Among these crosslinkable groups, in particular, an α-substituted methylacryl group [—OC (═O) —C (—CH ₂ Z) ═CH ₂ , Z = hydrocarbon group starting from a hetero atom], (meth) acrylic An ethylenically unsaturated bond group such as a group, an allyl group or a styryl group is preferred, and a (meth) acryl group or an allyl group is particularly preferred.

From a synthetic point of view, the second binder polymer comprises (i) at least one diisocyanate compound, (ii) a diol compound having at least one carboxyl group, (iii) a diol compound having at least one crosslinkable group and / or Or it is preferable to obtain by carrying out the polyaddition reaction of the diisocyanate compound which has at least 1 crosslinkable group, and the diol compound which does not have a carboxyl group as needed. According to such a method, it is easier to substitute a carboxyl group and a crosslinkable group in the side chain and a polyurethane skeleton in the main chain than to substitute and introduce a desired side chain after the reaction of the polyurethane resin. Two binder polymers can be produced.
Particularly preferably, the second binder polymer comprises (i) at least one diisocyanate compound, (ii) a diol compound having at least one carboxyl group, (iii) a diol compound having at least one crosslinkable group, and necessary Accordingly, (iv) a diol compound having no carboxyl group is preferably obtained by a polyaddition reaction.
Hereinafter, the diisocyanate compound and the diol compound, which are raw materials for the polyurethane resin as the second binder polymer, will be described.

(I) Diisocyanate Compound Examples of the diisocyanate compound include those represented by the following formula (4).

          OCN-L-NCO Formula (4)

In the formula, L represents a single bond or a divalent aliphatic or aromatic hydrocarbon group which may have a substituent.
If necessary, L may have other functional groups that do not react with isocyanate groups, such as carbonyl, ester, urethane, amide, ureido, and ether groups. More specifically, the substituent in L is preferably, for example, an alkyl, aralkyl, aryl, alkoxy, or halogeno group, and the divalent aliphatic or aromatic hydrocarbon group preferably has 1 to 20 carbon atoms. An alkylene group, an arylene group having 6 to 15 carbon atoms, and more preferably an alkylene group having 1 to 8 carbon atoms.

  Specific examples include the following. That is, 2,4-tolylene diisocyanate, dimer of 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate Aromatic diisocyanate compounds such as 1,5-naphthylene diisocyanate, 3,3′-dimethylbiphenyl-4,4′-diisocyanate; hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, dimer acid diisocyanate, etc. Aliphatic diisocyanate compounds; isophorone diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4 (or 2,6) diisocyanate Nitrate, cycloaliphatic diisocyanate compounds such as 1,3- (isocyanatomethyl) cyclohexane, etc .; reaction product of diol and diisocyanate such as adduct of 1 mol of 1,3-butylene glycol and 2 mol of tolylene diisocyanate The diisocyanate compound etc. which are are mentioned.

  A diisocyanate compound may be used independently and may be used in combination of 2 or more type. It is preferable to use a combination of two or more in terms of the balance between printing durability and stain resistance, and at least one aromatic diisocyanate compound (L is an aromatic group) and aliphatic diisocyanate compound (L is an aliphatic group). It is particularly preferred to use each species.

  The amount of the diisocyanate compound used is a molar ratio with respect to a diol compound (all diol compounds used in the second binder polymer) described later, preferably 0.8 to 1.2, more preferably 0.9 to 1.1. It is. If the diisocyanate compound is used in excess relative to the diol compound, and the isocyanate group remains at the polymer end, the isocyanate group finally remains by treating with an alcohol or amine after completion of the urethanization reaction. It is preferable that they are synthesized in a form that does not.

(Ii) Diol compound having at least one carboxyl group As the diol compound having at least one carboxyl group, a diol compound represented by the following formula (5), (6) or (7), or tetracarboxylic acid dianhydride And compounds obtained by ring-opening the product with a diol compound.

In the above formulas (5) to (7), R ¹ is a hydrogen atom, a substituent (for example, cyano, nitro, halogen atom (—F, —Cl, —Br, —I), —CONH ₂ , —COOR ¹¹³ , ^{-OR 113, -NHCONHR 113, -NHCOOR 113} , -NHCOR 113, -OCONHR 113 ( wherein, R ¹¹³ is. represents an alkyl group, an aralkyl group having 7 to 15 carbon atoms having 1 to 10 carbon atoms) each including An alkyl group, an aralkyl group, an aryl group, an alkoxy group, an aryloxy group, and preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, and an aryl group having 6 to 15 carbon atoms. Indicates.
L ¹⁰ , L ¹¹ and L ¹² may be the same or different, and may have a single bond or a substituent (for example, alkyl, aralkyl, aryl, alkoxy and halogeno groups are preferred). A divalent aliphatic or aromatic hydrocarbon group is shown. Preferably an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 15 carbon atoms, more preferably an alkylene group having 1 to 8 carbon atoms is shown. If necessary, L ¹⁰ , L ¹¹ , and L ¹² may have other functional groups that do not react with an isocyanate group, such as carbonyl, ester, urethane, amide, ureido, and ether groups. A ring may be formed by 2 or 3 of R ¹ , L ¹⁰ , L ¹¹ and L ¹² .
Ar represents a trivalent aromatic hydrocarbon group which may have a substituent, preferably an aromatic group having 6 to 15 carbon atoms.

Specific examples of the diol compound having a carboxyl group represented by the formula (5), (6) or (7) include those shown below.
3,5-dihydroxybenzoic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (2-hydroxyethyl) propionic acid, 2,2-bis (3-hydroxypropyl) propionic acid, Bis (hydroxymethyl) acetic acid, bis (4-hydroxyphenyl) acetic acid, 2,2-bis (hydroxymethyl) butyric acid, 4,4-bis (4-hydroxyphenyl) pentanoic acid, tartaric acid, N, N-dihydroxyethylglycine N, N-bis (2-hydroxyethyl) -3-carboxy-propionamide and the like.

  Further, as a preferable tetracarboxylic dianhydride used in the generation of the diol compound having at least one carboxyl group (generation method in which tetracarboxylic dianhydride is ring-opened with a diol compound), the following formula (8), The compound shown by (9) and (10) is mentioned.

In the above formulas (8) to (10), L ²¹ may have a single bond or a substituent (for example, alkyl, aralkyl, aryl, alkoxy, halogeno, ester or amide groups are preferred). An aliphatic or aromatic hydrocarbon group, —CO—, —SO—, —SO ₂ —, —O— or —S—. Preferred are a single bond, a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms, —CO—, —SO ₂ —, —O— or —S—.
R ² and R ³ may be the same or different and each represents a hydrogen atom, an optionally substituted alkyl, aralkyl, aryl, alkoxy, or halogeno group. Preferably, they are a hydrogen atom, a C1-C8 alkyl, a C6-C15 aryl, a C1-C8 alkoxy, or a halogeno group.
^{Two of} L ²¹ , R ² and R ³ may be bonded to form a ring.

R ⁴ and R ⁵ may be the same or different and each represents a hydrogen atom, an optionally substituted alkyl, aralkyl, aryl or halogeno group. Preferably they are a hydrogen atom, a C1-C8 alkyl, or a C6-C15 aryl group.
The L ^21, R ^4, although two may form a ring of R ^5.
L ²² and L ²³ may be the same or different and each represents a single bond, a double bond, or a divalent aliphatic hydrocarbon group which may have a substituent. A single bond, a double bond, or a methylene group is preferred.

  A represents a mononuclear or polynuclear aromatic ring which may have a substituent. Preferably it is a C6-C18 aromatic ring.

Specific examples of the compound represented by the above formula (8), (9) or (10) include those shown below.
That is, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride, 2,3,6 , 7-Naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,4′-sulfonyldiphthalic dianhydride, 2,2-bis (3,4 Dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 4,4 ′-[3,3 ′-(alkylphosphoryldiphenylene) -bis (iminocarbonyl)] diphthalic acid Aromatic tetracarboxylic dianhydrides such as dianhydrides, adducts of hydroquinone diacetate and trimetic anhydride, diacetyldiamine and trimetic anhydride; 5- (2,5-dioxote Trahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (Dainippon Ink Chemical Co., Ltd., Epicron B-4400), 1,2,3,4-cyclopentanetetracarboxylic Alicyclic tetracarboxylic dianhydrides such as acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, tetrahydrofuran tetracarboxylic dianhydride; 1,2,3,4-butanetetra Aliphatic tetracarboxylic dianhydrides such as carboxylic dianhydride and 1,2,4,5-pentanetetracarboxylic dianhydride may be mentioned.

  By ring-opening these tetracarboxylic dianhydrides with a diol compound, (ii) a diol compound having at least one carboxyl group can be synthesized. However, it is also possible to synthesize a polyurethane resin by first reacting the diol compound with the diisocyanate compound and reacting this reaction product with the tetracarboxylic dianhydride, and this method is also an aspect of the present invention. Is included. That is, as a method for introducing a structural unit derived from a tetracarboxylic dianhydride and a diol compound into the second binder polymer having a polyurethane skeleton in the present invention, there are the following methods.

a) A method of reacting an alcohol-terminated compound obtained by ring-opening tetracarboxylic dianhydride with a diol compound and a diisocyanate compound.
b) A method of reacting an alcohol-terminated urethane compound obtained by reacting a diisocyanate compound under an excess of a diol compound with tetracarboxylic dianhydride.

In addition, as the diol compound used for the ring-opening reaction at this time, a diol compound generally used for ring-opening carboxylic dianhydride can be used, and specifically, those shown below Is mentioned.
That is, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol, 1,3-butylene glycol, 1,6-hexanediol, 2-butene- 1,4-diol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-bis-β-hydroxyethoxycyclohexane, cyclohexanedimethanol, tricyclodecane dimethanol, hydrogenated bisphenol A, hydrogenated Bisphenol F, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, bisphenol F ethylene oxide adduct, bisphenol F pro Renoxide adduct, hydrogenated bisphenol A ethylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct, hydroquinone dihydroxyethyl ether, p-xylylene glycol, dihydroxyethyl sulfone, bis (2-hydroxyethyl) -2, Examples include 4-tolylene dicarbamate, 2,4-tolylene-bis (2-hydroxyethylcarbamide), bis (2-hydroxyethyl) -m-xylylenedicarbamate, and bis (2-hydroxyethyl) isophthalate.

Among the diol compounds having the above (ii) at least one carboxyl group, the compound represented by the general formula (5) is more preferable because of high solvent solubility and easy synthesis.
The second binder polymer in the present invention has a carboxyl group in the side chain of 0.2 to 4.0 meq / g, preferably 0.3 to 3.0 meq / g, more preferably 0.4 to 2.0 meq / g. g, particularly preferably 0.5 to 1.5 meq / g, most preferably 0.6 to 1.2 meq / g, and (ii) a diol compound having at least one carboxyl group is carboxyl It is desirable to introduce the group content so as to be the above amount.
Accordingly, the content of the structure derived from the diol compound having at least one carboxyl group in the second binder polymer is the number of carboxyl groups, the compound used as another diol component contained as required, and the obtained second binder. Although it is appropriately selected depending on the acid value and molecular weight of the polymer, the composition and pH of the developer, etc., it is preferably 5 to 45 mol%, more preferably 10 to 40 mol%, and particularly preferably 15 to 35 mol%.

(Iii)-(1) Diol compound having at least one crosslinkable group In the present invention, a diol compound having at least one crosslinkable group and / or a diisocyanate compound having at least one crosslinkable group described later are used. A crosslinkable group can be easily introduced into the side chain of the second binder polymer.
The diol compound having at least one crosslinkable group may be, for example, a commercially available one such as trimethylolpropane monoallyl ether, a halogenated diol compound, a triol compound or an aminodiol compound, and an unsaturated group. It may be a compound that is easily produced by a reaction with a contained carboxylic acid, acid chloride, isocyanate, alcohol, amine, thiol, or alkyl halide compound. Specific examples of these compounds include, but are not limited to, the compounds shown below.

  Among the diol compounds having at least one crosslinkable group, a diol having an ethylenically unsaturated bond group and having at least one secondary alcohol represented by the following general formula (G) is particularly preferable. A compound can be mentioned.

In the general formula (G), R ^{1 to} R ³ each independently represents a hydrogen atom or a monovalent organic group, A represents a divalent organic residue, and X represents an oxygen atom or a sulfur atom. or -N (R ¹²⁾ - represents, R ¹² represents a hydrogen atom or a monovalent organic group.
In addition, R < ¹ > -R < ³ > and X in this general formula (G) are synonymous with R < ⁴ > -R < ⁶ > and X in the crosslinkable group represented by general formula (A) demonstrated by the 1st binder polymer mentioned above. The preferred embodiments are also the same. R ¹² has the same meaning as R ^{1 to} R ³ (that is, the same as R ^{4 to} R ⁵ in the crosslinkable group represented by the general formula (A)).

By using the polyurethane resin derived from the diol compound represented by the general formula (G), the excessive molecular motion of the polymer main chain due to the secondary alcohol having a large steric hindrance can be effectively suppressed, and the layer coating An improvement in strength can be achieved.
Hereinafter, although the specific example of a diol compound represented by general formula (G) is shown, this invention is not limited to these.

(Iii)-(2) Disocyanate compound having at least one crosslinkable group Examples of the diisocyanate compound having at least one crosslinkable group include, but are not limited to, the following compounds. .

(Iv) Diol compound not having a carboxyl group As the diol compound not having a carboxyl group, a polyether diol compound, a polyester diol compound, a polycarbonate diol compound and the like are widely used.

Specific polyether diol compounds include those shown below.
That is, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, di-1,2-propylene glycol, tri-1,2-propylene glycol, tetra-1, 2-propylene glycol, hexa-1,2-propylene glycol, di-1,3-propylene glycol, tri-1,3-propylene glycol, tetra-1,3-propylene glycol, di-1,3-butylene glycol, Tri-1,3-butylene glycol, hexa-1,3-butylene glycol, polyethylene glycol having a weight average molecular weight of 1000, polyethylene glycol having a weight average molecular weight of 1500, poly having a weight average molecular weight of 2000 Tylene glycol, polyethylene glycol with a weight average molecular weight of 3000, polyethylene glycol with a weight average molecular weight of 7500, polypropylene glycol with a weight average molecular weight of 400, polypropylene glycol with a weight average molecular weight of 700, polypropylene glycol with a weight average molecular weight of 1000, polypropylene glycol with a weight average molecular weight of 2000 And polypropylene glycol having a weight average molecular weight of 3000, polypropylene glycol having a weight average molecular weight of 4000, and the like.
In addition, Sanyo Chemical Industries, Ltd. (trade names) PTMG650, PTMG1000, PTMG2000, PTMG3000, Sanyo Chemical Industries, Ltd. (trade names) New Pole PE-61, New Pole PE-62, New Pole PE-64, New Pole PE-68, New Pole PE-71, New Pole PE-74, New Pole PE-75, New Pole PE-78, New Pole PE-108, New Pole PE-128, Sanyo Chemical Industries ( (Trade name) New Paul BPE-20, New Pole BPE-20F, New Pole BPE-20NK, New Pole BPE-20T, New Pole BPE-20G, New Pole BPE-40, New Pole BPE-60, New Pole BPE-100, New Pole BPE-180, New Pole BPE-2P, New Pole BPE-23P, New Pole BPE-3P, New Pole BPE-5P, Sanyo Chemical Industries, Ltd., (Product Name) New Pole 50HB-100, New Pole 50HB-260, New Pole 50HB -400, New Pole 50HB-660, New Pole 50HB-2000, New Pole 50HB-5100, and the like.

  Examples of the polyester diol compound include compounds represented by the following formulas (12a), (12b), and (13).

In the formulas (12a), (12b) and (13), L ^2a , L ^2b , L ^3a , L ^3b and L ⁴ may be the same or different and may be a divalent aliphatic or aromatic hydrocarbon group. L ⁵ represents a divalent aliphatic hydrocarbon group. Preferably, L ^2a , L ^2b , L ^3a , L ^3b and L ⁴ are each an alkylene group, an alkenylene group, an alkynylene group and an arylene group, and L ⁵ is an alkylene group. Also, in L ^2a , L ^2b , L ^3a , L ^3b , L ⁴ and L ⁵ , other functional groups that do not react with isocyanate groups, such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group or halogen An atom or the like may be present.
n1a, n1b and n2 each represent an integer of 2 or more, preferably an integer of 2 to 100.

  Examples of the polycarbonate diol compound include a compound represented by the following formula (14).

In formula (14), L ⁶ may be the same or different and each represents a divalent aliphatic or aromatic hydrocarbon group. Preferably, L ⁶ is an alkylene group, an alkenylene group, an alkynylene group or an arylene group. In addition, other functional groups that do not react with the isocyanate group, such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group or halogen atom may be present in L ⁶ .
n3 represents an integer of 2 or more, preferably an integer of 2 to 100.

  Preferred specific examples of the diol compound represented by the above formula (12a), (12b), (13) or (14) include (Exemplary Compound No. 1) to (Exemplary Compound No. 18) shown below. It is done. In the specific examples, n represents an integer of 2 or more.

The second binder polymer comprises the above diisocyanate compound ((i) diisocyanate compound, (iii)-(2) diisocyanate compound having at least one crosslinkable group) and diol compound ((ii) diol compound having at least one carboxyl group) , (Iii)-(1) a diol compound having at least one crosslinkable group, and (iv) a diol compound having no carboxyl group) are known in the aprotic solvent according to their reactivity. It is synthesized by adding a catalyst and heating. The molar ratio (M _a : M _b ) of the diisocyanate compound and diol compound used in the synthesis is preferably 1: 1 to 1.2: 1, and the molecular weight or viscosity can be determined by treating with alcohols or amines. A product having the desired physical properties is synthesized in a form in which no isocyanate group remains in the end.

As an introduction amount of the crosslinkable group contained in the second binder polymer, in terms of equivalent, the side chain may contain a crosslinkable group of 0.3 meq / g or more, and further 0.35 to 1.50 meq / g. preferable.
Furthermore, as the introduction amount of the carboxyl group, as described above, the carboxyl group is 0.2 to 4.0 meq / g, preferably 0.3 to 3.0 meq / g, more preferably 0.4 to 2 in the side chain. It is desirable to have 0.0 meq / g, particularly preferably 0.5 to 1.5 meq / g, and most preferably 0.6 to 1.2 meq / g.

In order to make the introduction amount of the crosslinkable group within the above range, (iii)-(1) a diol compound having at least one crosslinkable group, and (iii)-(2) at least one crosslinkable group What is necessary is just to adjust content of the diisocyanate compound to have.
In order to set the molar ratio (M _a : M _b ) of the diisocyanate compound and the diol compound within the above range, (iii)-(1) a diol compound having at least one crosslinkable group and (iii)-(2 The content of the diisocyanate compound having at least one crosslinkable group, and (iv) the content of the diol compound having no carboxyl group may be adjusted.

  The molecular weight of the second binder polymer is preferably 10,000 or more in terms of weight average molecular weight, and more preferably in the range of 40,000 to 200,000. When the weight average molecular weight is within the above range, a photosensitive layer having particularly excellent image area strength and excellent non-image area developability with an alkaline developer can be obtained.

-Binder composition-
Here, the blending ratio (mass ratio) of the first binder polymer and the second binder polymer is not particularly limited, but a ratio of 1: 9 to 9: 1 is preferable, and 2: 8 to 8 A ratio of 1 is more preferred.
In addition to the first binder polymer and the second binder polymer, other known binder polymers may be used in combination with the photosensitive layer. In this case, the content of other known binder polymers is preferably 30% by mass or less with respect to the total amount of the binder.

  The total amount of the binder used in the photosensitive layer (the first binder polymer and the second binder polymer, and other known binder polymers used as necessary) is not particularly limited, but is usually in the photosensitive layer. It is 10-90 mass% with respect to the total mass of a non-volatile component, Preferably it is 20-80 mass%, More preferably, it is the range of 30-70 mass%.

(Polymerizable compound)
The polymerizable compound used in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and is selected from compounds having at least one ethylenically unsaturated bond, preferably two or more. Such a compound group is widely known in the industrial field, and these can be used without any particular limitation. These have chemical forms such as monomers, prepolymers, i.e. dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), and esters and amides thereof. In this case, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, or an amide of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound is used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxyl group, amino group or mercapto group with a monofunctional or polyfunctional isocyanate or epoxy, and a monofunctional or polyfunctional compound. A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an epoxy group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, a halogen group or In addition, 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. As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.

  Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol. Diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate , Tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3-methacryloxy- 2-hydroxypro ) Phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate.
Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.
Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.
Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

  Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240, JP-A-59-5241. Those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used. Furthermore, the ester monomers described above can also be used as a mixture.

  Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like. Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B-54-21726.

  In addition, urethane-based addition polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable, and specific examples thereof include, for example, one molecule described in JP-B-48-41708. A vinyl urethane compound containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxyl group represented by the following general formula to a polyisocyanate compound having two or more isocyanate groups. Can be mentioned.

CH ₂ = C (R ^a ) COOCH ₂ CH (R ^b ) OH... General formula (where R ^a and R ^b represent H or CH ₃ )

  Also, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, and JP-B-2-16765, JP-B-58-49860, JP-B-56-17654, Urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418 are also suitable. Further, by using addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238, It is possible to obtain a photopolymerizable composition excellent in the photosensitive speed.

  Other examples include polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191, JP-B-52-30490, and JP-A-52-30490. Mention may be made of polyfunctional acrylates and methacrylates such as reacted epoxy acrylates. Further, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337 and JP-B-1-40336, vinylphosphonic acid compounds described in JP-A-2-25493, and the like can also be mentioned. . In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, Journal of Japan Adhesion Association vol. 20, no. 7, pages 300 to 308 (1984), which are introduced as photocurable monomers and oligomers, can also be used.

About these polymerizable compounds, the details of usage, such as the structure, single use or combination, and addition amount can be arbitrarily set according to the final performance design. For example, the use method of the addition polymerizable compound can arbitrarily select an appropriate structure, blending, and addition amount from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface tackiness, and the like.
More specifically, the following viewpoints can be pointed out. From the viewpoint of photosensitive speed, a structure having a high unsaturated group content per molecule is preferable, and in many cases, a bifunctional or higher functionality is preferable. Further, in order to increase the strength of the image area, that is, the cured film, those having three or more functionalities are preferable, and further, by using together those having different functional numbers and different polymerizable groups, both photosensitivity and strength can be achieved. An adjustment method is also effective. A compound having a large molecular weight or a compound having high hydrophobicity is excellent in photosensitive speed and film strength, but is not preferable in terms of development speed and precipitation in a developer. In addition, the selection and use method of the addition polymerization compound is also an important factor for compatibility and dispersibility with other components in the photosensitive layer composition (for example, binder polymer, initiator, colorant, etc.). For example, the compatibility may be improved by using a low-purity compound or using two or more kinds in combination.
In the lithographic printing plate precursor according to the invention, a specific structure may be selected for the purpose of improving adhesion to a substrate and a protective layer described later. Furthermore, in the lithographic printing plate precursor according to the invention, a layer constitution / coating method such as undercoating or overcoating can be carried out.

Regarding the content of the polymerizable compound in the photosensitive layer composition, the solid content in the photosensitive layer composition is selected from the viewpoint of sensitivity, occurrence of phase separation, adhesiveness of the photosensitive layer, and precipitation from the developer. On the other hand, it is preferably used in the range of 5 to 80% by mass, more preferably 10 to 75% by mass, particularly preferably 20 to 60% by mass.
In addition, from the viewpoint of suppression of loss of the photosensitive layer, and further from the viewpoints of sensitivity, image forming property, and compatibility, the mass ratio of the polymerizable compound and the total amount of the binder polymer in the photosensitive layer composition is 3: 1 to 1: 3. The range is preferable, the range of 2: 1 to 1: 2 is more preferable, and the range of 1.5: 1 to 1: 1.5 is particularly preferable.

(Polymerization initiator)
The polymerization initiator used in the present invention has a function of initiating and advancing the curing reaction of the above-described polymerizable compound, and is a thermal decomposition type radical generator that decomposes by heat to generate radicals, and excitation of an infrared absorber. An electron transfer type radical generator that accepts electrons and generates radicals, or an electron transfer type radical generator that generates electrons by transferring electrons to an excited infrared absorber, thereby generating radicals. Any compound may be used as long as it is generated. Examples include onium salts, triazine compounds having a trihalomethyl group, peroxides, azo polymerization initiators, azide compounds, quinonediazides, active halogen compounds, oxime ester compounds, triaryl monoalkylborate compounds, etc. It is not limited to.
The polymerization initiator used here is preferably an onium salt, an active halogen compound, an oxime ester compound, a borate compound, etc. from the viewpoint of high sensitivity and storage stability, and in particular, a sulfonium salt, an iodonium salt, and a diazonium. An onium salt such as a salt is more preferably used.

Particularly preferred sulfonium salts include onium salts represented by the following general formula (1).

In the general formula (1), R ¹¹ , R ¹² and R ¹³ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferable substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or an aryloxy group having 12 or less carbon atoms. (Z ¹¹ ) ⁻ represents a counter ion selected from the group consisting of halogen ion, perchlorate ion, tetrafluoroborate ion, hexafluorophosphate ion, carboxylate ion, and sulfonate ion, preferably perchloric acid Ions, hexafluorophosphate ions, carboxylate ions, and aryl sulfonate ions.

Specific examples ([OS-1] to [OS-12]) of the onium salt represented by the general formula (1) are shown below, but are not limited thereto.

  In addition to the above, specific fragrances described in JP-A-2001-133696, JP-A-2002-148790, JP-A-2002-148790, JP-A-2002-350207, JP-A-2002-6482 Group sulfonium salts are also preferably used.

  In addition, examples of iodonium salts and diazonium salts that are particularly preferably used include those represented by the following general formulas (2) and (3).

In the general formula (2), Ar ²¹ and Ar ²² each independently represent an aryl group having 20 or less carbon atoms which may have a substituent. Preferred substituents when this aryl group has a substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or a group having 12 or less carbon atoms. An aryloxy group is mentioned. (Z ²¹ ) ⁻ represents a counter ion having the same meaning as (Z ¹¹ ) ⁻ .

In General Formula (3), Ar ³¹ represents an aryl group having 20 or less carbon atoms, which may have a substituent. Preferred examples of the substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, an aryloxy group having 12 or less carbon atoms, and 12 or less carbon atoms. Examples thereof include an alkylamino group, a dialkylamino group having 12 or less carbon atoms, an arylamino group having 12 or less carbon atoms, or a diarylamino group having 12 or less carbon atoms. (Z ³¹ ) ⁻ represents a counter ion having the same meaning as (Z ¹¹ ) ⁻ .

  Specific examples of onium salts that can be suitably used in the present invention [OI-1] to [OI-10] and [ON-1] to [ON-5] (general formulas (2) and (3) The onium salt shown by ()) is included, However, It is not limited to these.

  The polymerization initiator (radical generator) used here preferably has a maximum absorption wavelength of 400 nm or less, and more preferably 360 nm or less. By making the absorption wavelength in the ultraviolet region in this way, the lithographic printing plate precursor can be handled under white light.

  The total content of the polymerization initiator is from 0.1 to 50% by mass, preferably from 0.5 to 30%, based on the total solid content constituting the photosensitive layer, from the viewpoint of sensitivity and the occurrence of stains in the non-image area during printing. % By mass, particularly preferably 1 to 20% by mass.

Moreover, only 1 type may be used for a polymerization initiator and it may use 2 or more types together. When two or more polymerization initiators are used in combination, for example, a plurality of suitably used sulfonium salt polymerization initiators may be used, or a sulfonium salt polymerization initiator and another polymerization initiator may be used in combination. Also good. When the sulfonium salt polymerization initiator and another polymerization initiator are used in combination, the content ratio (mass ratio) is preferably 100/1 to 100/50, more preferably 100/5 to 100/25.
The polymerization initiator may be added to the same layer as other components, or another layer may be provided and added thereto.

  Here, when a sulfonium salt polymerization initiator is used as the polymerization initiator, since the sensitivity is high, the radical polymerization reaction effectively proceeds and the strength of the formed image portion becomes very high. Therefore, combined with the high oxygen blocking function of the protective layer described later, a lithographic printing plate having high image area strength can be produced, and as a result, printing durability is further improved. In addition, since the sulfonium salt polymerization initiator itself is excellent in stability over time, even when the produced lithographic printing plate precursor is stored, the occurrence of an undesirable polymerization reaction is effectively suppressed. Will also have.

(Sensitizing dye)
The photosensitive layer may contain a sensitizing dye known in the art for the purpose of increasing the sensitivity. For example, by adding a sensitizing dye having a maximum absorption at 300 to 450 nm, a sensitizing dye having a maximum absorption at 500 to 600 nm, and an infrared absorber having a maximum absorption at 750 to 1400 nm, each is normally used in the industry. It is possible to provide a high-sensitivity lithographic printing plate corresponding to the 405 nm violet laser, 532 nm green laser, and 803 nm IR laser.

(Infrared absorber)
Hereinafter, an infrared absorber having a maximum absorption at 750 to 1400 nm that is preferably used in the present invention will be described in detail.
The infrared absorber used here is in an electronically excited state with high sensitivity to irradiation (exposure) of an infrared laser, and the electron transfer, energy transfer, heat generation (photothermal conversion function), etc. related to the electron excited state are photosensitive layers. It is presumed that it acts on a polymerization initiator coexisting therein to cause a chemical change in the polymerization initiator to generate a radical. In any case, the addition of an infrared absorber is particularly suitable for plate making directly drawn with an infrared laser beam having a wavelength of 750 nm to 1400 nm, and exhibits higher image forming properties than conventional lithographic printing plate precursors. can do.

  The infrared absorber is preferably a dye or pigment having an absorption maximum at a wavelength of 750 nm to 1400 nm.

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, etc. Is mentioned.
Examples of preferable dyes include cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-60-78787, JP-A-58-173696, 58-181690, JP-A-58-194595, etc., methine dyes, JP-A-58-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59- No. 73996, JP-A-60-52940, JP-A-60-63744 and the like, Naphthoquinone dyes described in JP-A-58-112792, etc., British Patent 434,875 And cyanine dyes.

  Also, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) pyrylium salt described in US Pat. No. 3,881,924, Trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59-41363, 59-84248 Nos. 59-84249, 59-146063, 59-146061, pyranlium compounds, cyanine dyes described in JP-A-59-216146, US Pat. No. 4,283,475 The pentamethine thiopyrylium salts described above and the pyrylium compounds disclosed in Japanese Patent Publication Nos. 5-13514 and 5-19702 are also preferably used. . Moreover, as another example preferable as a dye, the near-infrared absorptive dye described as the formula (I) and (II) in US Patent 4,756,993 can be 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 ¹ represents a hydrogen atom, a halogen atom, -NPh ₂ , X ² -L ¹ or a group shown below. Here, X ² represents an oxygen atom, a nitrogen atom, or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an aromatic ring having a hetero atom, or 1 to 1 carbon atom containing a hetero atom. 12 hydrocarbon groups are shown. In addition, a hetero atom here shows N, S, O, a halogen atom, and Se. X _a ^- is Z _a which will be described below ^- has the same definition as, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom.

R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. In view of storage stability of the photosensitive layer coating solution, R ¹ and R ² are preferably hydrocarbon groups having 2 or more carbon atoms, and R ¹ and R ² are bonded to each other to form a 5-membered ring or It is particularly preferable that a 6-membered ring is formed.

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

  Specific examples of the cyanine dye represented by the general formula (a) that can be suitably used include those described in paragraph numbers [0017] to [0019] of JP-A No. 2001-133969.

More particularly preferred examples include specific indolenine cyanine dyes described in JP-A-2002-278057 as exemplified below.

  Examples of pigments include commercially available pigment and color index (CI) manuals, “Latest Pigment Handbook” (edited by the Japan Pigment Technology Association, published in 1977), “Latest Pigment Applied Technology” (published by CMC, published in 1986), “Printing” The pigments described in "Ink Technology", published by CMC Publishing, 1984) can be used.

  Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Among these pigments, carbon black is preferable.

  These pigments may be used without surface treatment, or may be used after surface treatment. The surface treatment method includes a method of surface coating with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (eg, silane coupling agent, epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The above-mentioned surface treatment methods are described in “Characteristics and Application of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.

  The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm. Within this preferred particle size range, excellent dispersion stability of the pigment in the photosensitive layer can be obtained, and a uniform photosensitive layer can be obtained.

  As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).

  These infrared absorbers may be added to the same layer as other components, or another layer may be provided and added thereto.

  From the viewpoint of uniformity in the photosensitive layer and durability of the photosensitive layer, these infrared absorbers are 0.01 to 50% by mass, preferably 0.1 to 10% by mass, based on the total solid content constituting the photosensitive layer. In the case of a dye, it is particularly preferably 0.5 to 10% by mass, and in the case of a pigment, it is particularly preferably 0.1 to 10% by mass.

(Other ingredients)
In addition to the above components, other components known in the art suitable for the use, production method and the like can be appropriately added to the photosensitive layer. Hereinafter, preferred additives will be exemplified.

-Colorant-
A dye or pigment may be added for the purpose of coloring the photosensitive layer. Thereby, what is called plate inspection property, such as the visibility of the image after plate-making as a printing plate and suitability for an image density measuring machine, can be improved. Specific examples of the colorant include pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide, and dyes such as ethyl violet, crystal violet, azo dyes, anthraquinone dyes, and cyanine dyes. Among them, a cationic dye is preferable.
The addition amount of the dye and the pigment as the colorant is preferably about 0.5% by mass to about 5% by mass with respect to the non-volatile components in the total photosensitive layer composition.

-Polymerization inhibitor-
Further, it is desirable to add a small amount of a thermal polymerization inhibitor in order to prevent unnecessary thermal polymerization of a polymerizable compound having an ethylenically unsaturated double bond, that is, a polymerizable compound. Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol ), 2,2′-methylenebis (4-methyl-6-tert-butylphenol), N-nitrosophenylhydroxyamine primary cerium salt and the like.
The addition amount of the thermal polymerization inhibitor is preferably about 0.01% by mass to about 5% by mass with respect to the mass of the nonvolatile component in the photosensitive layer composition. If necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide or the like may be added to prevent polymerization inhibition by oxygen and may be unevenly distributed on the surface of the layer in the course of drying after coating. The addition amount of the higher fatty acid derivative is preferably about 0.5% by mass to about 10% by mass with respect to the nonvolatile components in the photosensitive layer composition.

-Other additives-
Further, the photosensitive layer is added with known additives such as an inorganic filler for improving the physical properties of the cured film, other plasticizers, and a sensitizing agent capable of improving the ink inking property on the surface of the photosensitive layer. Also good. Examples of plasticizers include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, triacetyl glycerin, and addition polymerization with binder polymer. Generally, it can be added in a range of 10% by mass or less based on the total mass with the compound.
In addition, for the purpose of improving the film strength (printing durability) of the resulting lithographic printing plate, or in order to enhance the effect of heating and exposure after development, addition of a UV initiator, a thermal crosslinking agent, etc. is also performed. Is also possible.

<Protective layer>
Next, the protective layer provided on the photosensitive layer will be described in detail.
It is desirable that the protective layer does not substantially inhibit the transmission of light used for exposure, has excellent adhesion to the photosensitive layer, and can be easily removed in a development process after exposure. Such a device relating to the protective layer has been conventionally made and is described in detail in US Pat. No. 3,458,311 and JP-A-55-49729.
Further, since the negative lithographic printing plate precursor in the present invention has a design of a polymerization type photosensitive layer, the negative lithographic printing plate precursor has an oxygen blocking ability that blocks oxygen in the atmosphere during exposure and exhibits a polymerization inhibiting action. Is desirable. On the other hand, it is also desirable to have an oxygen permeability that exhibits dark polymerization inhibition from the viewpoint of stability during storage or suitability for safelight, and it is desirable to provide a protective layer having a low oxygen barrier property to the extent that it has both functions. .
Furthermore, in the present invention, the protective layer preferably contains an inorganic stratiform compound such as a mica compound, and the addition of the inorganic stratiform compound allows the masters to be laminated together without requiring a slip sheet. . As a result, handling and storage stability during storage can be improved, and productivity during plate making can also be improved.

(Water-soluble polymer compound)
As a material used as a main component for the protective layer, it is preferable to use a water-soluble polymer compound having relatively excellent crystallinity. Specifically, polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic Water-soluble polymers such as polyacrylic acid are well known in the art. Of these, the use of polyvinyl alcohol as the main component gives the best results for basic properties such as oxygen barrier properties and development removability. The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether, and an acetal as long as it contains an unsubstituted vinyl alcohol unit for having the required oxygen barrier properties and water solubility. . Similarly, some of them may have other repeating units.
Specifically, PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC made by Kuraray Co., Ltd. , PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA -420, PVA-613, L-8 and the like. Examples of the copolymer include 88-100% hydrolyzed polyvinyl acetate chloroacetate or propionate, polyvinyl formal and polyvinyl acetal, and copolymers thereof. Other useful polymers include polyvinyl pyrrolidone, gelatin and gum arabic, and these may be used alone or in combination.

Examples of the polyvinyl alcohol suitably used in the present invention include those that are hydrolyzed 71 to 100% and have a molecular weight in the range of 200 to 2400. It is more preferable to use polyvinyl alcohol having a saponification degree of 91 mol% or more from the viewpoint of high oxygen barrier properties, excellent film forming properties, and a low adhesion surface.
Specifically, PVA-102, PVA-103, PVA-104, PVA-105, PVA-110, PVA-117, PVA-120, PVA-124, PVA-117H, PVA-135H made by Kuraray Co., Ltd. , PVA-HC, PVA-617, PVA-624, PVA-706, PVA-613, PVA-CS, PVA-CST, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., Gohsenol NL-05, NM-11, NM-14 , AL-06, P-610, C-500, A-300, AH-17, JF-04, JF-05, JF-10, JF-17, JF-17L, manufactured by Nihon Venture Bipoval Co., Ltd. , JM-05, JM-10, JM-17, JM-17L, JT-05, JT-13, JT-15 and the like.

Furthermore, what acid-modified polyvinyl alcohol is also used suitably. Specifically, itaconic acid and maleic acid-modified carboxy-modified polyvinyl alcohol and sulfonic acid-modified polyvinyl alcohol are preferable. These acid-modified polyvinyl alcohols can also be used more preferably if the saponification degree is 91 mol% or more.
Specific examples of the acid-modified polyvinyl alcohol include KL-118, KM-618, KM-118, SK-5102, MP-102, R-2105, manufactured by Kuraray Co., Ltd., and Nippon Synthetic Chemical Industry Co., Ltd. , GOHSENAL CKS-50, T-HS-1, T-215, T-350, T-330, T-330H, AF-17, AT-17, etc. manufactured by Nihon Ventures & Poval Co., Ltd. are included.

The water-soluble polymer compound is 45 to 95% by mass with respect to the total solid content in the protective layer in consideration of the sensitivity of the obtained negative lithographic printing plate precursor and the adhesion between the laminated lithographic printing plate precursors. It is preferable to contain in the range of 50-90 mass%, and it is more preferable to contain.
As the water-soluble polymer compound, at least one kind may be used, and a plurality of kinds may be used in combination. Even when a plurality of types of water-soluble polymer compounds are used in combination, the total amount is preferably in the above-described mass range.

  On the other hand, in the protective layer, the adhesion of the photosensitive layer to the image area and the uniformity of the film are also extremely important in handling the printing plate precursor. That is, when a hydrophilic layer made of a water-soluble polymer is laminated on an oleophilic photosensitive layer, film peeling due to insufficient adhesive force is likely to occur, and the peeled part causes defects such as poor film hardening due to inhibition of oxygen polymerization. On the other hand, various proposals have been made to improve the adhesion between these two layers. For example, U.S. Patent Application No. 292,501 and U.S. Patent Application No. 44,563 disclose an acrylic emulsion or a water-insoluble vinylpyrrolidone-vinyl acetate copolymer in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesiveness can be obtained by mixing 20 to 60% by mass and the like and laminating on the photosensitive layer. Of course, any of these known techniques can be applied.

  Among these, polyvinyl alcohol and polyvinyl pyrrolidone may be used in combination in the protective layer from the viewpoints of adhesive strength with the photosensitive layer, sensitivity, and generation of unnecessary fog. The addition ratio (mass ratio) is preferably 3/1 or less of polyvinyl alcohol / polyvinylpyrrolidone. In addition to this polyvinylpyrrolidone, acidic celluloses, gelatin, gum arabic, polyacrylic acid, and copolymers thereof, which are relatively excellent in crystallinity, can be used in combination with specific polyvinyl alcohol. .

(Inorganic layered compound)
Furthermore, the protective layer preferably contains polyvinyl alcohol having a saponification degree of 91 mol% or more and an inorganic layered compound. By using an inorganic stratiform compound in combination, the oxygen barrier property is further increased, and the film strength of the protective layer is further improved to improve scratch resistance, and matte properties can be imparted to the protective layer.
As a result, the protective layer can suppress deterioration due to deformation or the like and generation of scratches in addition to the above-described barrier property against oxygen or the like. Furthermore, by providing a matte property to the protective layer, when the negative lithographic printing plate precursor is laminated, the adhesion between the protective layer surface of the lithographic printing plate precursor and the back surface of the adjacent lithographic printing plate precursor is suppressed. Is possible.

Examples of the inorganic layered compound include, for example, the general formula: A (B, C) ₂ -5D ₄ O ₁₀ (OH, F, O) ₂ [where A is any of K, Na, Ca, B and C Is any one of Fe (II), Fe (III), Mn, Al, Mg, and V, and D is Si or Al. And mica groups such as natural mica and synthetic mica.

Specific examples of mica represented by the above general formula and other mica used in the present invention include muscovite, soda mica, phlogopite, biotite, and micaceous mica. Synthetic mica includes non-swelling mica such as fluor-phlogopite mica KMg ₃ (AlSi ₃ O ₁₀ ) F ₂ , potassium tetrasilicon mica KMg _2.5 (Si ₄ O ₁₀ ) F ₂ , and Na tetrasilicic mica NaMg _2.5. (Si ₄ O ₁₀ ) F ₂ , Na or Li Teniolite (Na, Li) Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ , Montmorillonite Na or Li Hectorite (Na, Li) _1/8 Mg _2/5 Examples thereof include swelling mica such as Li _1/8 (Si ₄ O ₁₀ ) F ₂ . In addition, synthetic smectites are also useful.

Of the mica compounds, fluorine-based swellable mica is particularly useful. That is, this swellable synthetic mica has a laminated structure composed of unit crystal lattice layers with a thickness of about 10 to 15 mm, and the substitution of metal atoms in the lattice is significantly larger than other viscosity minerals. As a result, the lattice layer is deficient in positive charge, and in order to compensate for this, cations such as Li ⁺ , Na ⁺ , Ca ²⁺ and Mg ²⁺ are adsorbed between the layers. The cations present between these layers are called exchangeable cations and exchange with various cations. In particular, when the cation between the layers is Li ⁺ or Na ⁺ , since the ionic radius is small, the bond between the layered crystal lattices is weak, and the layer swells greatly with water. If shear is applied in this state, it will easily cleave and form a stable sol in water. Swellable synthetic mica has a strong tendency and is useful in the present invention. In particular, swellable synthetic mica is preferably used.

  The shape of the mica compound is preferably as small as possible from the viewpoint of diffusion control, and the plane size is preferably as long as the smoothness of the coated surface and the transmittance of actinic rays are not impaired. Accordingly, the aspect ratio is 20 or more, preferably 100 or more, particularly preferably 200 or more. The aspect ratio is the ratio of the thickness to the major axis of the particle, and can be measured from, for example, a projected view of the particle by a micrograph. The larger the aspect ratio, the greater the effect that can be obtained.

  The average major axis of the mica compound is 0.3 to 20 μm, preferably 0.5 to 10 μm, and particularly preferably 1 to 5 μm. The average thickness of the particles is 0.1 μm or less, preferably 0.05 μm or less, particularly preferably 0.01 μm or less. Specifically, for example, the swellable synthetic mica that is a representative compound has a thickness of 1 to 50 nm and a surface size (major axis) of about 1 to 20 μm.

  The amount of the mica compound contained in the protective layer is such that the protective layer is protected from the viewpoints of suppression of adhesion between the lithographic printing plate precursors and generation of scratches, reduction in sensitivity due to interruption during laser exposure, and low oxygen permeability. The range is preferably 5 to 50% by mass, particularly preferably 10 to 40% by mass, based on the total solid content. Even when a plurality of types of mica compounds are used in combination, the total amount of these mica compounds is preferably the above-described mass ratio.

Components of the protective layer (selection of polyvinyl alcohol and mica compound, use of additives), coating amount, and the like are selected in consideration of fogging, adhesion, and scratch resistance in addition to oxygen barrier properties and development removability.
Protective layer in the present invention, because the oxygen permeability at 25 ° C. -1 atm is preferably not more than 0.5ml / m ² · day or more 100ml / m ² · day, to achieve this oxygen permeability, It is preferable to use a method of adjusting the coating amount.

  The protective layer may be added with a colorant (water-soluble dye) that is excellent in light transmittance used when exposing the photosensitive layer and that can efficiently absorb light having a wavelength not related to exposure. Good. Thereby, safelight aptitude can be improved, without reducing a sensitivity.

(Formation of protective layer)
The method for applying the protective layer is not particularly limited, and the protective layer is formed by applying an aqueous protective layer coating solution containing the above water-soluble polymer onto the photosensitive layer. For example, the method described in US Pat. No. 3,458,311 or JP-A-55-49729 can also be applied.

Hereinafter, it supplements about the coating method of the protective layer containing inorganic layered compounds, such as a mica compound, and water-soluble polymer compounds, such as polyvinyl alcohol. Even in this case, similarly to the above, a dispersion liquid in which an inorganic layered compound such as a mica compound is dispersed is prepared, and the dispersion liquid and a water-soluble polymer compound such as polyvinyl alcohol (or a water-soluble compound) are prepared. An aqueous solution in which a polymer compound is dissolved) and a protective layer coating solution formed by coating on the photosensitive layer is applicable.
Further, an example of a general dispersion method of the mica compound used for the protective layer will be described. First, 5 to 10 parts by mass of the swellable mica compound mentioned above as a preferable mica compound is added to 100 parts by mass of water, and the mixture is thoroughly swelled and swollen, and then dispersed by a disperser. Examples of the disperser used here include various mills that disperse mechanically by applying a direct force, a high-speed stirring disperser having a large shearing force, and a disperser that provides high-intensity ultrasonic energy. Specifically, ball mill, sand grinder mill, visco mill, colloid mill, homogenizer, tisol bar, polytron, homomixer, homo blender, ketdy mill, jet agitator, capillary emulsifier, liquid siren, electrostrictive ultrasonic generator, An emulsifying device having a Paulman whistle can be used. In general, a 2 to 15% by mass dispersion of the mica compound dispersed by the above method is highly viscous or gelled and has very good storage stability. When preparing a coating solution for a protective layer using this dispersion, after diluting with water and stirring sufficiently, a water-soluble polymer compound such as polyvinyl alcohol (or a water-soluble polymer compound such as polyvinyl alcohol) is added. It is preferable to prepare by blending with a dissolved aqueous solution.

  Known additives such as a surfactant for improving the coating property and a water-soluble plasticizer for improving the physical properties of the resulting film can be added to the protective layer coating solution. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, sorbitol and the like. A water-soluble (meth) acrylic polymer can also be added. Furthermore, known additives for improving the adhesion to the photosensitive layer and the temporal stability of the coating solution may be added to the coating solution.

The coating amount of the protective layer is 0.1 g / m ² to 4 in terms of maintaining the film strength and scratch resistance of the protective layer obtained, maintaining the image quality, and maintaining appropriate oxygen permeability for imparting safelight suitability. 0.0 g / m ² is preferable, and 0.3 g / m ^{2 to} 3.0 g / m ² is more preferable.

〔substrate〕
As the substrate used here, a substrate subjected to a hydrophilization treatment as described later is used. Examples of such a substrate include paper, polyester film, and aluminum plate. Among them, a surface having good dimensional stability, relatively inexpensive, and excellent hydrophilicity and strength by surface treatment as required. An aluminum plate that can be provided is further preferred. A composite sheet in which an aluminum sheet is bonded on a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327 is also preferable.

  The aluminum plate here is a metal plate mainly composed of dimensionally stable aluminum. In addition to a pure aluminum plate, an aluminum plate containing aluminum as a main component and containing a trace amount of foreign elements, or aluminum (alloy) Is meant to include laminated or vapor-deposited plastic film or paper. In the following description, the above-mentioned substrates made of aluminum or an aluminum alloy are generically used as an aluminum substrate. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is 10% by mass or less. Of these, a pure aluminum plate is preferable, but completely pure aluminum is difficult to manufacture in terms of refining technology, and may contain a slightly different element. Thus, the composition of the aluminum plate is not specified, and conventionally known and used materials such as JIS A 1050, JIS A 1100, JIS A 3103, and JIS A 3005 can be appropriately used. it can.

The thickness of the aluminum substrate is about 0.1 mm to 0.6 mm. This thickness can be appropriately changed according to the size of the printing press, the size of the printing plate, and the user's desire.
Such an aluminum substrate is subjected to a surface treatment which will be described later to be hydrophilized.

(Roughening treatment)
Examples of the roughening treatment method include mechanical roughening, chemical etching, and electrolytic grain as disclosed in JP-A-56-28893. Furthermore, an electrochemical surface roughening method in which the surface of the aluminum surface is electrochemically roughened in hydrochloric acid or nitric acid electrolyte, and the aluminum surface is ground with a metal wire, and the aluminum brush surface is polished with a polishing ball and an abrasive. A mechanical graining method such as a pole grain method, a brush grain method in which the surface is roughened with a nylon brush and an abrasive, can be used, and the above roughening methods can be used alone or in combination. Among them, a method usefully used for roughening is an electrochemical method in which roughening is chemically carried out in hydrochloric acid or nitric acid electrolyte, and a suitable anodic electricity is 50 C / dm ^{2 to} 400 C / dm ² . It is a range. More specifically, in the electrolytic solution containing from 0.1 to 50% hydrochloric acid or nitric acid, the temperature 20 to 80 ° C., for 1 second to 30 minutes, alternating at a current density of 100C / dm ² ~400C / dm ² It is preferable to perform direct current electrolysis.

  The roughened aluminum substrate may be chemically etched with acid or alkali. Etching agents suitably used are caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide and the like, and preferred ranges of concentration and temperature are 1 to 50% and 20%, respectively. ~ 100 ° C. Pickling is performed to remove dirt (smut) remaining on the surface after etching. As the acid used, nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, borohydrofluoric acid and the like are used. In particular, as a method for removing smut after the electrochemical surface roughening treatment, contact with 15 to 65 mass% sulfuric acid at a temperature of 50 to 90 ° C. as described in JP-A-53-12739 is preferable. And the alkali etching method described in Japanese Patent Publication No. 48-28123. After the treatment as described above, the method and conditions are not particularly limited as long as the surface roughness Ra of the treated surface is about 0.2 to 0.5 μm.

(Anodizing treatment)
The aluminum substrate that has been processed as described above to form an oxide layer is then anodized.
In the anodizing treatment, sulfuric acid, phosphoric acid, oxalic acid, or an aqueous solution of boric acid / sodium borate is used alone or in combination as a main component of the electrolytic bath. In this case, the electrolyte solution may of course contain at least components normally contained in at least an Al alloy plate, an electrode, tap water, groundwater and the like. Further, the second and third components may be added. Here, the second and third components are, for example, metal ions such as Na, K, Mg, Li, Ca, Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn, and ammonium ions. Examples include cations, nitrate ions, carbonate ions, chloride ions, phosphate ions, fluorine ions, sulfite ions, titanate ions, silicate ions, borate ions and the like, and the concentration is 0 to 10,000 ppm. May be included. There are no particular limitations on the conditions for the anodizing treatment, but the treatment is preferably performed by direct current or alternating current electrolysis at a treatment liquid temperature of 10 to 70 ° C. and a current density of 0.1 to 40 A / m ² at 30 to 500 g / liter. . The thickness of the formed anodic oxide film is in the range of 0.5 to 1.5 μm. Preferably it is the range of 0.5-1.0 micrometer. The processing conditions are such that the substrate prepared by the above processing falls within the range of the pore diameter of the micropores present in the anodized film within the range of 5 to 10 nm and the pore density of 8 × 10 ¹⁵ to 2 × 10 ¹⁶ pieces / m ^2. Is preferably selected.

As the hydrophilic treatment of the substrate surface, widely known methods can be applied. As a particularly preferred treatment, a hydrophilic treatment with silicate or polyvinylphosphonic acid is performed. The film is formed with a Si or P element amount of ^{2 to} 40 mg / m ² , more preferably 4 to 30 mg / m ² . The coating amount can be measured by fluorescent X-ray analysis.

  The hydrophilization treatment is carried out by applying an anodized film to an aqueous solution containing 1 to 30% by weight, preferably 2 to 15% by weight of alkali metal silicate or polyvinylphosphonic acid, and having a pH of 10 to 13 at 25 ° C. This is performed by immersing the aluminum substrate on which is formed at 15 to 80 ° C. for 0.5 to 120 seconds, for example.

  As the alkali metal silicate used for the hydrophilization treatment, sodium silicate, potassium silicate, lithium silicate, or the like is used. Examples of the hydroxide used for increasing the pH of the aqueous alkali metal silicate solution include sodium hydroxide, potassium hydroxide, and lithium hydroxide. In addition, you may mix | blend alkaline-earth metal salt or a group IVB metal salt with said process liquid. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and water-soluble substances such as sulfate, hydrochloride, phosphate, acetate, oxalate, and borate. Salt. Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, potassium titanium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, zirconium tetrachloride, etc. Can be mentioned.

  The alkaline earth metal salt or Group IVB metal salt can be used alone or in combination of two or more. A preferable range of these metal salts is 0.01 to 10% by mass, and a more preferable range is 0.05 to 5.0% by mass. Silicate electrodeposition as described in US Pat. No. 3,658,662 is also effective. Surface treatment combining a substrate subjected to electrolytic grain as disclosed in JP-B-46-27481, JP-A-52-58602, JP-A-52-30503, and the above-mentioned anodizing treatment and hydrophilization treatment Is also useful.

[Preparation of lithographic printing plate precursor]
In the lithographic printing plate precursor according to the invention, a photosensitive layer and a protective layer are provided in this order on a substrate, and an undercoat layer, an intermediate layer and the like may be further provided as necessary. Such a lithographic printing plate precursor can be produced by dissolving the above-described coating liquids containing the various components in an appropriate solvent and sequentially applying the solution onto a substrate.

When coating the photosensitive layer, the photosensitive layer components are dissolved in various organic solvents to form a photosensitive layer coating solution, which is applied onto the substrate or the undercoat layer.
Solvents used here include acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, Acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethylene glycol monomethyl ether, Ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxypropyl acetate, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, methyl lactate, lactic acid There are ethyl and the like. These solvents can be used alone or in combination. The solid content in the photosensitive layer coating solution is suitably 2 to 50% by mass.

The coating amount of the photosensitive layer mainly affects the sensitivity of the photosensitive layer, the strength of the exposed film, the developability, and the printing durability of the resulting printing plate, and is preferably selected as appropriate according to the application. For the lithographic printing plate precursor for scanning exposure, the coating amount is suitably in the range of about 0.1 g / m ² to about 10 g / m ² in terms of the mass after drying. More preferably from 0.5 to 5 g / m ^2.

[Intermediate layer (undercoat layer)]
The above lithographic printing plate precursor may be provided with an intermediate layer (undercoat layer) for the purpose of improving the adhesion and soiling between the photosensitive layer and the substrate. Specific examples of such an intermediate layer include JP-B-50-7481, JP-A-54-72104, JP-A-59-101651, JP-A-60-149491, JP-A-60-232998, JP-A-3-56177, JP-A-4-282737, JP-A-5-16558, JP-A-5-246171, JP-A-7-159983, JP-A-7-314937, JP-A-8-202025, Special Kaihei 8-320551, JP 9-34104, JP 9-236911, JP 9-269593, JP 10-69092, JP 10-115931, JP 10-161317, JP 10-260536, JP-A-10-282682, JP-A-11-84684, JP-A-10-69092, JP-A-10-115931, Kaihei 11-38635, JP-A-11-38629, JP-A-10-282645, JP-A-10-301262, JP-A-11-24277, JP-A-11-109641, JP-A-10-319600, JP-A-10-319600 11-84684, JP-A-11-327152, JP-A-2000-10292, JP-A-2000-235254, JP-A-2000-352854, JP-A-2001-209170, Japanese Patent Application No. 11-284091, etc. Can be mentioned.

<Plate making method>
Hereinafter, a method for making a planographic printing plate in the present invention will be described.
The plate making method of this planographic printing plate is a laminate in which a plurality of the above-described planographic printing plate precursors are laminated by directly contacting the protective layer and the back surface of the aluminum substrate, and this is set in a plate setter. After the printing plate precursor is automatically conveyed one by one, it is exposed at a wavelength of 750 nm to 1400 nm. Thereafter, it is usually subjected to a development process, the non-image area is removed, and the plate making process is completed. Even if the lithographic printing plate precursor of the present invention described above is laminated without interposing the interleaf, the adhesion between the lithographic printing plate precursors and the generation of scratches on the protective layer are suppressed. It can be applied to such a plate making method. According to this plate making method, since a laminate in which lithographic printing plate precursors are laminated without interposing the interleaving paper is used, it is not necessary to remove the interleaving paper, and productivity in the plate making process is improved.
In addition, the lithographic printing plate precursor may be laminated alternately with the interleaving paper to form a laminate.

  The photosensitive layer to which the lithographic printing plate making method of the present invention is applied has an unexposed area developing speed of 80 nm / sec or more with respect to an alkaline developer having a pH of 10 to 13.5, and exposure of the alkaline developer. It is preferable that the penetration rate in the part has a physical property of 50 nF / sec or less. The method for measuring the developing speed of the unexposed portion of the photosensitive layer and the penetration speed of the alkali developer into the cured photosensitive layer is the same as the method described in Japanese Patent Application No. 2004-248535 previously filed by the present applicant. Can be used. Control of the developing speed of the unexposed part of the photosensitive layer and the penetration speed of the alkali developer into the cured photosensitive layer can be performed by a conventional method, but as a typical method, a method using the specific binder polymer In addition, the addition of a hydrophilic compound is useful for improving the developing speed of the unexposed area, and the means for adding a hydrophobic compound is useful for suppressing the penetration of the developer into the exposed area.

〔exposure〕
The light source used for the exposure process may be any light source that can be exposed at a wavelength of 750 nm to 1400 nm, but an infrared laser is preferable. In particular, image exposure is preferably performed by a solid-state laser and a semiconductor laser that emit infrared rays having a wavelength of 750 nm to 1400 nm. The laser output is preferably 100 mW or more, and a multi-beam laser device is preferably used in order to shorten the exposure time. The exposure time per pixel is preferably within 20 μsec. The amount of energy per unit irradiated on the lithographic printing plate precursor is preferably 10 to 300 mJ / cm ² .

  In this exposure processing, exposure can be performed by overlapping the light beams of the light sources. Overlap means that exposure is performed under the condition that the sub-scanning pitch width is smaller than the beam diameter. The overlap can be expressed quantitatively by FWHM / sub-scanning pitch width (overlap coefficient), for example, when the beam diameter is expressed by the half width (FWHM) of the beam intensity. In the present invention, this overlap coefficient is preferably 0.1 or more.

  The light source scanning method of the exposure apparatus is not particularly limited, and a cylindrical outer surface scanning method, a cylindrical inner surface scanning method, a planar scanning method, and the like can be used. The channel of the light source may be a single channel or a multi-channel, but in the case of a cylindrical outer surface system, a multi-channel is preferably used.

  The lithographic printing plate of the present invention can be subjected to a development treatment without being subjected to special heat treatment and water washing treatment after the exposure treatment. By not performing this heat treatment, image non-uniformity due to the heat treatment can be suppressed. Further, by performing neither heat treatment nor water washing treatment, stable high-speed processing is possible in the development processing.

〔developing〕
Hereinafter, the developer used in the development process performed after the exposure process will be described.

<Developer>
Although the developing solution used here is not specifically limited, Usually, alkaline aqueous solution of pH 14 or less is applied.

(Alkaline agent)
Examples of the alkaline agent used in the developer include trisodium phosphate, potassium, ammonium, sodium borate, potassium, ammonium, sodium hydroxide, potassium, ammonium, and lithium. Inorganic alkaline agent and monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, di Examples include organic alkali agents such as isopanolamine, ethyleneimine, ethylenediamine, pyridine, and tetramethylammonium hydroxide. These may be used alone or in combination of two or more.

  Moreover, alkali silicate can be mentioned as alkali agents other than the above. Alkali silicates may be used in combination with a base. The alkali silicate to be used exhibits alkalinity when dissolved in water, and examples thereof include sodium silicate, potassium silicate, lithium silicate, and ammonium silicate. These alkali silicates may be used alone or in combination of two or more.

The developer is a mixture ratio of silicon oxide SiO ₂ which is a component of silicate as a hydrophilic component of the substrate and alkali oxide M ₂ O (M represents an alkali metal or ammonium group) as an alkali component, and By adjusting the concentration, it can be easily adjusted to the optimum range. The mixing ratio (SiO ₂ / M ₂ O molar ratio) of silicon oxide SiO ₂ and alkali oxide M ₂ O is an unclean stain caused by excessive dissolution (etching) of the anodic oxide film on the substrate, From the viewpoint of suppressing the generation of insoluble gas due to complex formation between dissolved aluminum and silicate, it is preferably in the range of 0.75 to 4.0, more preferably in the range of 0.75 to 3.5. used.

The concentration of alkali silicate in the developer includes the effect of suppressing dissolution (etching) of the anodic oxide film on the substrate, the developability, the effect of suppressing precipitation and crystal formation, and the prevention of gelation during neutralization in the waste liquid. From the viewpoint of effects and the like, the SiO ₂ amount is preferably 0.01 to 1 mol / L, more preferably 0.05 to 0.8 mol / L with respect to the mass of the developer.

(Aromatic anionic surfactant)
The developer preferably contains an aromatic anionic surfactant from the viewpoint of development acceleration effect, dispersion stabilization of the negative polymerizable photosensitive layer component and protective layer component in the developer, and stabilization of development processing. .
The aromatic anionic surfactant is not particularly limited, but is preferably a compound represented by the following general formula (A) or general formula (B).

In the general formula (A) or the general formula (B), R ¹ and R ³ each independently represents a linear or branched alkylene group having 1 to 5 carbon atoms, specifically, an ethylene group , Propylene group, butylene group, pentylene group, and the like, among which ethylene group and propylene group are particularly preferable.
m and n each independently represent an integer selected from 1 to 100. Among them, 1 to 30 are preferable, and 2 to 20 are more preferable. When m is 2 or more, a plurality of R ¹ may be the same or different. Similarly, when n is 2 or more, a plurality of R ³ may be the same or different.
t and u each independently represents 0 or 1.

R ² and R ⁴ each independently represents a linear or branched alkyl group having 1 to 20 carbon atoms, specifically, methyl group, ethyl group, propyl group, butyl group, hexyl group, dodecyl group Among them, a methyl group, an ethyl group, an iso-propyl group, an n-propyl group, an n-butyl group, an iso-butyl group, and a tert-butyl group are particularly preferable.
p and q each represent an integer selected from 0 to 2; Y ¹ and Y ² each represent a single bond or an alkylene group having 1 to 10 carbon atoms. Specifically, a single bond, a methylene group or an ethylene group is preferred, and a single bond is particularly preferred.
(Z ¹ ) ^{r +} and (Z ² ) ^{s +} each independently represents an alkali metal ion, an alkaline earth metal ion, or an ammonium ion that is unsubstituted or substituted with an alkyl group. Sodium ion, potassium ion, magnesium ion, calcium ion, ammonium ion, secondary to quaternary ammonium ion substituted with an alkyl group, aryl group, or aralkyl group in the range of 1 to 20 carbon atoms, etc. In particular, sodium ion is preferable. r and s each represent 1 or 2.
Specific examples are shown below, but are not particularly limited thereto.

  These aromatic anionic surfactants may be used alone or in appropriate combination of two or more. Further, the amount of the aromatic anionic surfactant added is not particularly limited, but considering the developability, the solubility of the photosensitive layer components, and the printing durability of the resulting printing plate, the aromatic anionic surfactant is added. The concentration of the anionic surfactant is preferably in the range of 1.0 to 10% by mass, and more preferably in the range of 2 to 10% by mass.

In addition to the aromatic anionic surfactant, other surfactants may be used in combination with the developer. Examples of other surfactants include polyoxyethylene naphthyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene stearyl ether, Polyoxyethylene alkyl esters such as oxyethylene stearate, sorbitan monolaurate, sorbitan monostearate, sorbitan distearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan trioleate, sorbitan alkyl esters, glycerol mono Nonionic surfactants such as monoglyceride alkyl esters such as stearate and glycerol monooleate.
The content of these other surfactants in the developer is preferably from 0.1 to 10% by mass in terms of active ingredients.

(Chelating agent for divalent metals)
Moreover, it is preferable to contain the chelating agent with respect to a bivalent metal in the said developing solution in order to suppress the influence by the calcium ion etc. which are contained in hard water, for example. Examples of the chelating agent for the divalent metal include Na ₂ P ₂ O ₇ , Na ₅ P ₃ O ₃ , Na ₃ P ₃ O ₉ , Na ₂ O ₄ P (NaO ₃ P) PO ₃ Na ₂ , Calgon (polymetaline). Polyphosphates such as ethylenediaminetetraacetic acid, its potassium salt, its sodium salt, its amine salt; diethylenetriaminepentaacetic acid, its potassium salt, sodium salt; triethylenetetraminehexaacetic acid, its potassium salt, its sodium salt Hydroxyethylethylenediaminetriacetic acid, its potassium salt, its sodium salt; nitrilotriacetic acid, its potassium salt, its sodium salt; 1,2-diaminocyclohexanetetraacetic acid, its potassium salt, its sodium salt; 1,3-diamino-2 -Propanol tetraacetic acid, its potassium salt, 2-phosphonobutanetricarboxylic acid-1,2,4, potassium salt thereof, sodium salt thereof; 2-phosphonobutanone tricarboxylic acid-2,3,4, 1-phosphonoethanetricarboxylic acid-1,2,2, potassium salt, sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, potassium salt, sodium salt; aminotri Organic phosphonic acids such as (methylenephosphonic acid), its potassium salt, its sodium salt and the like, among others, ethylenediaminetetraacetic acid, its potassium salt, its sodium salt, its amine salt; ethylenediaminetetra (methylenephosphonic acid) ), Its ammonium salt, its potassium salt; hexamethyl Emissions diamine tetra (methylene phosphonic acid), an ammonium salt, its potassium salt is preferred.
The optimum amount of such a chelating agent varies depending on the hardness of the hard water used and the amount used, but is generally 0.01 to 5% by mass, more preferably 0% in the developing solution at the time of use. It is used in the range of 0.01 to 0.5% by mass.

  In addition, an alkali metal salt of an organic acid or an alkali metal salt of an inorganic acid may be added to the developer as a development regulator. For example, sodium carbonate, potassium, ammonium, sodium citrate, potassium, ammonium and the like may be used alone or in combination of two or more.

  As a more preferred embodiment, a more preferred development replenisher in the present invention contains an oxycarboxylic acid chelating agent having an ability to form a water-soluble chelate compound with aluminum ions, an alkali metal hydroxide, and a surfactant, It is a development replenisher characterized by being an aqueous solution containing no silicate and having a pH of 11 to 13.5. By using such a development replenisher, the aluminum hydroxide has excellent developability and characteristics that do not impair the strength of the image area of the plate material, and is formed by elution of the aluminum substrate by the alkali of the developer. This effectively suppresses the deposition of dirt mainly composed of aluminum hydroxide on the surface of the developing bath roller of the automatic processor and the subsequent accumulation of aluminum hydroxide precipitate in the washing bath. It can be processed stably for a period.

  In addition to the above components, the following components can be used in the developer as necessary. For example, benzoic acid, phthalic acid, p-ethylbenzoic acid, pn-propylbenzoic acid, p-isopropylbenzoic acid, pn-butylbenzoic acid, pt-butylbenzoic acid, pt-butylbenzoic acid Acids, p-2-hydroxyethylbenzoic acid, decanoic acid, salicylic acid, organic carboxylic acids such as 3-hydroxy-2-naphthoic acid; organic solvents such as propylene glycol; other reducing agents, dyes, pigments, water softeners And preservatives.

  The pH of the developer is in the range of 10 to 12.5 at 25 ° C. from the viewpoints of developability to non-image areas and reduction of damage to the image areas during development, and handling of the developer. Is preferable, and it is more preferable that it is the range of pH 11-12.5.

  The conductivity x of the developer is preferably 2 <x <30 mS / cm, and more preferably 5 to 25 mS / cm. In order to adjust the conductivity, it is preferable to add an alkali metal salt of an organic acid, an alkali metal salt of an inorganic acid, or the like as a conductivity adjusting agent.

  The developer can be used as a developer and a development replenisher for the exposed lithographic printing plate precursor, and is preferably applied to an automatic processor. When developing using an automatic developing machine, the developing solution becomes fatigued according to the amount of processing. Therefore, the processing capability may be restored using a replenishing solution or a fresh developing solution. This replenishment method is also preferably applied to the plate making method in the present invention.

  Furthermore, it is also possible to apply replenishment by the method described in US Pat. No. 4,882,246 in order to restore the processing capacity of the developing solution using an automatic developing machine. In addition, the developers described in JP-A-50-26601, 58-54341, JP-B-56-39464, 56-42860, and 57-7427 are also applicable.

  The lithographic printing plate precursor thus developed is subjected to washing water, surface activity as described in JP-A Nos. 54-8002, 55-11545, 59-58431, and the like. A method of post-treatment with a rinsing solution containing an agent or the like, a desensitizing solution containing gum arabic, a starch derivative or the like is also applicable, and these treatments can be used in various combinations.

  Furthermore, for the purpose of improving the image strength and printing durability, it is also possible to apply whole surface post-heating or whole surface exposure to the developed image. For the heating after the development, very strong conditions can be used. Usually, the heating temperature is 200 to 500 ° C.

The planographic printing plate obtained by such processing is loaded on an offset printing machine and used for printing a large number of sheets.
As a plate cleaner used for removing stains on the plate during printing, a conventionally known plate cleaner for PS plate is used. For example, multi cleaner, CL-1, CL-2, CP, CN -4, CN, CG-1, PC-1, SR, IC (manufactured by Fuji Photo Film Co., Ltd.) and the like.

EXAMPLES Hereinafter, although an Example demonstrates this invention, it is not specifically limited to these.
[Example 1]
<Production of substrate>
The surface treatment shown below was performed using a JIS A 1050 aluminum plate having a thickness of 0.30 mm and a width of 1030 mm.

(surface treatment)
In the surface treatment, the following various treatments (a) to (f) were continuously performed. In addition, after each process and water washing, the liquid was drained with the nip roller.

(A) The aluminum plate was etched at a caustic soda concentration of 26 mass%, an aluminum ion concentration of 6.5 mass%, and a temperature of 70 ° C. to dissolve the aluminum plate at 5 g / m ² . Thereafter, it was washed with water.

(B) A desmut treatment by spraying was performed with a 1% by mass aqueous solution of nitric acid having a temperature of 30 ° C. (including 0.5% by mass of aluminum ions), and then washed with water.

(C) An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass aqueous nitric acid solution (including 0.5% by mass aluminum ions and 0.007% by mass ammonium ions) at a temperature of 30 ° C. The AC power source was subjected to an electrochemical surface roughening treatment using a carbon electrode as a counter electrode using a trapezoidal rectangular wave alternating current with a time TP of 2 msec until the current value reached a peak from zero and a duty ratio of 1: 1. Ferrite was used for the auxiliary anode. The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 250 C / cm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode. Thereafter, it was washed with water.

(D) The aluminum plate was spray-etched at 35 ° C. with a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass to dissolve the aluminum plate by 0.2 g / m ² , The removal of the smut component mainly composed of aluminum hydroxide generated during chemical roughening and the edge portion of the generated pit were dissolved to smooth the edge portion. Thereafter, it was washed with water.

(E) A desmut treatment by spraying was performed with a 25% by weight aqueous solution of sulfuric acid having a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), followed by washing with water by spraying.

(F) Anodization was performed for 50 seconds at a sulfuric acid concentration of 170 g / liter (containing 0.5 mass% of aluminum ions), a temperature of 33 ° C., and a current density of 5 (A / dm ² ). Thereafter, it was washed with water. The mass of the anodic oxide film at this time was 2.7 g / m ² .
The surface roughness Ra of the aluminum substrate thus obtained was 0.27 (measuring instrument: Surfcom, manufactured by Tokyo Seimitsu Co., Ltd., stylus tip diameter 2 μm).

<Undercoat layer>
Next, the following undercoat layer coating solution was applied to the aluminum substrate with a wire bar and dried at 90 ° C. for 30 seconds. The coating amount was 10 mg / m ² .

(Coating solution for undercoat layer)
-Polymer compound A having the following structure (weight average molecular weight: 30,000) 0.05 g
・ Methanol 27g
・ Ion exchange water 3g

<Photosensitive layer>
Next, the following photosensitive layer coating solution [P-1] was prepared and applied to the aluminum substrate using a wire bar. Drying was performed at 115 ° C. for 34 seconds with a hot air drying apparatus to form a photosensitive layer. The coating amount after drying was 1.4 g / m ² .

(Photosensitive layer coating solution [P-1])
・ Infrared absorber (IR-1) 0.074g
-Polymerization initiator (OS-12) 0.280g
・ Additive (PM-1) 0.151g
・ Polymerizable compound (AM-1) 1.00 g
-Binder polymer (BT-1) (weight average molecular weight: 100,000) 1.00 g
・ Ethyl violet (C-1) 0.04g
-Binder polymer (BT-2) 1.00g
(N = 15, weight average molecular weight: 90,000)
・ Fluorine-based surfactant 0.015g
(Megafuck F-780-F Dainippon Ink and Chemicals,
Methyl isobutyl ketone (MIBK) 30% by mass solution)
・ Methyl ethyl ketone 10.4g
・ Methanol 4.83g
・ 10.4 g of 1-methoxy-2-propanol

  In addition, the polymerization initiator (OS-12) used for the said photosensitive layer coating liquid refers to what is mentioned as a compound example of the onium salt represented by the above-mentioned general formula (1). Further, infrared absorber (IR-1), additive (PM-1), polymerizable compound (AM-1), binder polymer (BT-1), ethyl violet (C-1), and binder polymer (BT) The structure of -2) is shown below.

<Protective layer>
Synthetic mica (Somasif ME-100, 8 mass% aqueous dispersion, manufactured by Coop Chemical Co., Ltd.) and polyvinyl alcohol having a saponification degree of 91 mol% or more (Goselan CKS-50: saponification) 99 mol%, polymerization degree 300, sulfonic acid-modified polyvinyl alcohol Nippon Synthetic Chemical Industry Co., Ltd.) and a surfactant (Nihon Emulsion Co., Emalex 710) mixed aqueous solution (coating solution for protective layer) It apply | coated with the wire bar and it was made to dry with 125 degreeC 75 second with a warm air type drying apparatus.
The content ratio of mica solid content / polyvinyl alcohol / surfactant in the mixed aqueous solution (protective layer coating solution) is 16/76/2 (mass%), and the total coating amount (the coating amount after drying). ) Was 1.6 g / m ² .
As a result, a planographic printing plate precursor of Example 1 was obtained.

[Examples 2 to 6]
In the composition of the photosensitive layer coating solution of Example 1, the lithographic printing of Examples 2 to 6 was carried out in the same manner as in Example 1 except that the addition amounts of BT-1 and BT-2 were changed as shown in Table 1 below. I got the original version.

Example 7
In the composition of the photosensitive layer coating solution of Example 1, Example 7 was carried out in the same manner as in Example 1 except that the first binder polymer used was changed from BT-1 to BT-5 (weight average molecular weight: 110,000). A lithographic printing plate precursor was obtained.

[Comparative Example 1]
The lithographic plate of Comparative Example 1 was prepared in the same manner as in Example 1 except that BT-2 was not added and 2.0 g of BT-5 was added instead of BT-1 in the photosensitive layer coating solution of Example 1. A printing plate master was obtained.

[Comparative Example 2]
In Comparative Example 1, a lithographic printing plate precursor of Comparative Example 2 was obtained in the same manner as Comparative Example 1 except that the protective layer was not provided.

[Comparative Example 3]
Comparative Example 3 was the same as Comparative Example 1 except that BT-5 was changed to BT-2 (that is, 2.0 g of BT-2 alone was added as a binder) in the photosensitive layer coating solution of Comparative Example 1. A lithographic printing plate precursor was obtained.

[Comparative Example 4]
In Comparative Example 3, a lithographic printing plate precursor of Comparative Example 4 was obtained in the same manner as Comparative Example 3 except that no protective layer was provided.

[Comparative Example 5]
In the photosensitive layer coating solution of Comparative Example 1, BT-5 was replaced with BT-3 (n = average 17, weight average molecular weight: 100,000) (ie, 2.0 g of BT-3 alone was added as a binder) Produced a planographic printing plate precursor of Comparative Example 5 in the same manner as Comparative Example 1.

[Comparative Example 6]
A lithographic printing plate precursor of Comparative Example 6 was obtained in the same manner as in Example 1 except that BT-2 was replaced with BT-3 in the photosensitive layer coating solution of Example 1.

[Comparative Example 7]
A lithographic printing plate precursor of Comparative Example 7 was obtained in the same manner as in Example 1 except that BT-1 was replaced with BT-4 in the photosensitive layer coating solution of Example 1.

[Evaluation]
(1) Evaluation of Sensitivity The obtained lithographic printing plate precursor was exposed with a Trendsetter 800IIQuantum manufactured by Creo at a resolution of 2400 dpi, an outer drum rotation speed of 200 rpm, and an output of 0 to 8 W with a change of 0.15 in logE. The exposure was performed under conditions of 25 ° C. and 50% RH. After the exposure, neither heat treatment nor water washing treatment was performed, and development was performed at a conveyance speed (line speed) of 2 m / min and a development temperature of 30 ° C. using an automatic developing machine LP-1310HII manufactured by FUJIFILM Corporation. The developer used was a 1: 4 (mass ratio) water dilution of DH-N, the developer replenisher was a 1: 1.4 (mass ratio) water dilution of FCT-421, and the finisher was FUJIFILM Corporation. A 1: 1 (mass ratio) water dilution of GN-2K manufactured by KK was used.
The cyan density of the image area density of the lithographic printing plate obtained by development was measured using a Macbeth reflection densitometer RD-918 and using a red filter equipped with the densitometer. The reciprocal of the exposure necessary to obtain a measured density of 0.9 was used as an index of sensitivity. The evaluation results were based on the sensitivity of the lithographic printing plate obtained in Example 1 as a standard (100), and the sensitivity of other lithographic printing plates was a relative evaluation thereof. The larger the value, the better the sensitivity.

(2) Evaluation of printing durability The obtained lithographic printing plate was printed using a DIC-GEOS (N) black ink manufactured by Dainippon Ink & Chemicals, Inc. using a Lithlon printing machine manufactured by Komori Corporation. The number of printed sheets at the time when it was visually recognized that the image density began to fade was used as an index. In this evaluation result, the printing number of the lithographic printing plate obtained in Example 1 was used as a reference (100), and the printing durability of other lithographic printing plates was evaluated as a relative evaluation. The larger the value, the better the sensitivity.

(3) Observation of missing photosensitive layer The obtained lithographic printing plate precursor was allowed to stand for 3 days under conditions of 60 ° C. and 15% RH, and then subjected to a Trendsetter 800II Quantum manufactured by Creo, with a resolution of 2400 dpi, an outer drum rotation speed of 200 rpm, and an output of 6 W. The whole surface was completely exposed. The exposure was performed under conditions of 25 ° C. and 50% RH. After the exposure, neither heat treatment nor water washing treatment was performed, and development was performed at a conveyance speed (line speed) of 2 m / min and a development temperature of 30 ° C. using an automatic developing machine LP-1310HII manufactured by FUJIFILM Corporation. The presence or absence of the photosensitive layer missing in the solid image was visually confirmed and evaluated according to the following criteria.
○: No omission occurred.
X: Omission occurred.

As is clear from Table 1, it can be seen that the planographic printing plate precursors of the examples have good sensitivity and printing durability, and the photosensitive layer is not missing.
On the other hand, the lithographic printing plate precursor of Comparative Example 1 having only BT-5 had good sensitivity but was inferior in printing durability as compared with Examples, and the photosensitive layer was lost.
Further, Comparative Example 3 having only BT-2, Comparative Example 5 having only BT-3, BT-4 and BT not corresponding to the first binder polymer (not having the repeating structure represented by the general formula (I)) In the lithographic printing plate precursor of Comparative Example 7 used in combination with -2, the photosensitive layer was not detached, but the sensitivity and printing durability were not satisfactory.
Furthermore, the lithographic printing plate precursor of Comparative Example 6 using BT-3 which does not correspond to the second binder polymer (not having a crosslinkable group) together with BT-1 did not cause the photosensitive layer to come off. The printing durability was not satisfactory.
Further, the lithographic printing plate precursors of Comparative Examples 2 and 4 having no protective layer showed very poor results in both sensitivity and printing durability.

Claims (6)

On the substrate, a photosensitive layer containing a polymerization initiator, a polymerizable compound and a binder polymer, and a protective layer are sequentially laminated,
The photosensitive layer includes a first binder polymer containing a repeating unit represented by the following general formula (I), and a second binder having a carboxyl group and a crosslinkable group in the side chain and a polyurethane skeleton in the main chain. A negative lithographic printing plate precursor comprising at least a polymer.

(In General Formula (I), R ¹ represents a hydrogen atom or a methyl group, and R ² contains two or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. And A represents an oxygen atom or —NR ³ —, and R ³ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. N represents an integer of 1 to 5.)   The negative lithographic printing plate precursor according to claim 1, wherein the protective layer contains an inorganic stratiform compound.   The negative lithographic printing plate precursor as claimed in claim 1 or 2, wherein the photosensitive layer contains an infrared absorber.   The negative lithographic printing plate precursor as claimed in any one of claims 1 to 3, wherein the first binder polymer further comprises a repeating unit having a crosslinkable group in the side chain.   The negative lithographic printing plate according to claim 4, wherein the crosslinkable group of the first binder polymer is at least one selected from the group consisting of a (meth) acryl group, an allyl group, and a styryl group. Original edition.   The crosslinkable group of the second binder polymer is at least one selected from the group consisting of a (meth) acryl group and an allyl group. Negative type lithographic printing plate precursor.