JP4462846B2 - Planographic printing plate precursor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lithographic printing plate precursor, and in particular, to a lithographic printing plate precursor that is provided with an intermediate layer that interacts with a heat-sensitive layer and that can achieve both printing durability and stain resistance at a high level.
[0002]
[Prior art]
In recent years, with the development of solid-state lasers and semiconductor lasers having a light emitting region from near infrared to infrared, systems using these infrared lasers have attracted attention as systems for directly making plates from computer digital data.
As a positive lithographic printing plate material for infrared laser for direct plate-making, for example, a substance that absorbs light and generates heat and a positive photosensitive compound such as quinonediazide compounds are added to an alkaline aqueous solution-soluble resin. Has been proposed (see Patent Document 1). In the image formation of such a positive type lithographic printing plate precursor, in the image part, the positive photosensitive compound acts as a dissolution inhibitor that substantially lowers the solubility of the alkaline aqueous solution-soluble resin, and in the non-image part, the positive type The photosensitive compound is decomposed by heat and exhibits no dissolution inhibiting ability, so that the aqueous alkali-soluble resin can be removed by development processing.
[0003]
In addition, it is known that an onium salt or a compound capable of forming a hydrogen bond network with low alkali solubility has an alkali dissolution inhibiting action of an alkali-soluble polymer. As an image recording material for infrared laser, it is known that a composition using a cationic infrared absorbing dye as a dissolution inhibitor for an alkaline water-soluble polymer exhibits a positive action (see Patent Document 2). This positive action is an action in which the infrared absorbing dye absorbs the laser beam, and the effect of suppressing the dissolution of the polymer film at the irradiated portion is eliminated by the generated heat to form an image.
In the support used for such a lithographic printing plate precursor, studies have been actively made to make the surface of the support hydrophilic in order to prevent contamination of non-image areas. For example, when a metal support such as an aluminum plate is used as a base material, various types of treatments such as anodized aluminum substrate, or silicate treatment of the anodized aluminum substrate to further increase the hydrophilicity, etc. Technology has been proposed.
[0004]
However, the hydrophilic treatment layer formed by various treatments for improving hydrophilicity does not necessarily have excellent affinity with the image recording layer, and the hydrophilic treatment layer and the image provided thereon Adhesion with the recording layer is reduced (under severe printing conditions), and the image recording layer may be peeled off during printing. That is, various treatments for improving hydrophilicity are effective in preventing smearing of non-image areas, but there is a problem that sufficient printing durability in image areas cannot be obtained (for example, Patent Document 3). 4).
[0005]
Therefore, in order to improve the adhesion between the hydrophilic support surface and the image recording layer, a method of providing various intermediate layers between the support and the image recording layer has been proposed.
Although the lithographic printing plate precursor obtained by such a method has improved adhesion to the lithographic printing plate support in the image area and sufficient printing durability is obtained, in the non-image area, the image recording layer is developed during development. Is not removed quickly, and remains as a residual film on the surface of the lithographic printing plate support, causing ink to adhere to the surface and causing stains.
[0006]
As described above, it is known that in any of the above-described methods, it is difficult to satisfy both the stain resistance in the non-image area and the printing durability in the image area at a satisfactory level.
Therefore, it is desired to provide a lithographic printing plate precursor that is excellent in surface hydrophilicity and that can satisfy both the adhesion to the image recording layer in the image area and the image recording layer removability in the non-image area.
[0007]
[Patent Document 1]
JP-A-7-285275
[Patent Document 2]
International Publication No. 97/39894 Pamphlet
[Patent Document 3]
US Pat. No. 3,511,661
[Patent Document 4]
US Pat. No. 3,136,636
[0008]
[Problems to be solved by the invention]
In order to solve the above problems, the present inventors have proposed a lithographic printing plate precursor provided with an intermediate layer containing a polymer compound containing a specific structural unit such as p-vinylbenzoic acid (Japanese Patent Laid-Open No. Hei 10). -69092). Further, a lithographic printing plate precursor provided with an intermediate layer containing a polymer (random polymer) having a monomer having an acid group and a monomer having an onium group has been proposed (Japanese Patent Laid-Open No. 2000-108538).
Although these lithographic printing plate precursors have a certain improvement effect on the above-mentioned problems, the printing durability is further improved by improving the adhesion between the lithographic printing plate support and the image recording layer. In addition, there is a demand for further improvement that effectively suppresses the occurrence of contamination even in non-image areas.
[0009]
Accordingly, an object of the present invention is to provide a lithographic printing plate precursor that can achieve both printing durability and stain resistance at a high level.
[0010]
[Means for Solving the Problems]
As a result of diligent investigations on the above problems, the inventors of the present invention provided an image recording layer containing a water-insoluble and alkali-soluble resin on a lithographic printing plate support provided with a hydrophilic treatment layer. When an intermediate layer containing a compound having an interacting functional group is provided between them, the image-recording layer is obtained without impairing excellent stain resistance due to the hydrophilic treatment layer and the water-insoluble and alkali-soluble resin. It has been found that the adhesiveness can be improved and the printing durability can be improved.
This invention is made | formed based on the said knowledge, and provides the following (I)-(II).
[0011]
(I) A positive-type heat-sensitive layer containing an infrared absorbing dye and a water-insoluble and alkali-soluble resin on a lithographic printing plate support subjected to a hydrophilic treatment and having increased solubility in an alkaline aqueous solution by heating was provided. A lithographic printing plate precursor,
An intermediate containing a compound having a functional group capable of interacting with the water-insoluble and alkali-soluble resin (contained in the positive thermal layer) between the lithographic printing plate support and the positive thermal layer. A lithographic printing plate precursor comprising a layer.
[0012]
(II) The compound having a functional group capable of interacting with the water-insoluble and alkali-soluble resin has at least one functional group selected from the group consisting of the following general formulas (1) to (4) in the side chain. The lithographic printing plate precursor as described in (I) above, which is a polymer.
[Chemical formula 2]
(In the formula, Y represents a single bond or a linking group to a polymer main chain skeleton, Ar is a heteroaryl group containing one or more nitrogen atoms as ring-constituting atoms and may have a substituent, R ₁ ~ R _Five Are each independently a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent, and R ₂ And R _Three May combine with each other to form a ring structure, and R _Four And R _Five May combine with each other to form a ring structure, m is an integer of 1 to 100, and n is an integer of 2 or more. )
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
[Middle layer]
The intermediate layer of the present invention is a layer containing a compound having a functional group capable of interacting with a water-insoluble and alkali-soluble resin contained in a positive heat-sensitive layer described later.
Here, the interaction is not particularly limited, and may be a chemical interaction or a physical interaction, but is preferably a chemical interaction.
[0014]
The functional group capable of such interaction is not particularly limited, but may be a functional group capable of forming a complex with a part of the water-insoluble and alkali-soluble resin (particularly a substituent present in the resin). The strength of the interaction is suitable, and it is preferable in that the printing durability and stain resistance of the lithographic printing plate can be compatible.
In the present invention, it is preferable to appropriately select the functional group according to the water-insoluble and alkali-soluble resin used in the image recording layer so that the interaction with the water-insoluble and alkali-soluble resin falls within a suitable range. When the above interaction is in a suitable range, the image recording layer in the non-image area is easily removed by development processing, and no stain is generated, and the adhesive strength with the image recording layer is strong and the printing durability is improved. Great effect.
Therefore, from the above viewpoint, in the present invention, the resin and the functional group are adjusted so that the interaction is in a suitable range, and as an index thereof, for example, turbidity when these are mixed or Examples include, but are not limited to, judgment based on the ability to form a complex between the resin and the functional group, which can be confirmed by a change in viscosity or the like.
[0015]
The functional group that enables the interaction is not particularly limited because it can be appropriately selected depending on the resin as described above. Below, an example of this functional group is given.
It is preferable for the reason described later that the interaction is a moderate functional group. Examples of such a functional group include a functional group capable of hydrogen bonding with a phenolic hydroxyl group contained in an alkali-soluble resin. Specifically, a functional group containing a nitrogen atom or an oxygen atom is preferable. If such an interaction is a moderate functional group, it can be easily adjusted to an interaction range suitable for producing the effects of the present invention.
The functional group containing a nitrogen atom is not particularly limited, and examples thereof include an amino group, a nitrogen-containing aromatic ring group, a functional group having an amide bond or a urea bond, and the like, which is a phenolic group contained in an alkali-soluble resin. From the viewpoint of the strength of interaction with a hydroxyl group, availability, etc., a nitrogen-containing aromatic ring group and a functional group having an amide bond are preferred.
Moreover, it does not specifically limit as a functional group containing an oxygen atom, For example, the functional group which has an ether bond or a carbonyl bond etc. are mentioned, From a viewpoint of stability etc., the functional group which has an ether bond is preferable.
[0016]
Examples of the functional group that forms a very strong interaction with the alkali-soluble resin include a functional group having a cationic structure such as an ammonium salt, a sulfonium salt, or a phosphonium salt. In order to more effectively demonstrate the effect of the present invention to easily remove the image recording layer in the non-image area and improve the stain resistance in the development processing, the functional group includes the entire functional group such as the cationic structure. It is preferably a functional group having no charge as
[0017]
Among the functional groups described above, the functional groups represented by the following general formulas (1) to (4) are particularly preferable.
[Chemical 3]
(In the formula, Y represents a single bond or a linking group to a polymer main chain skeleton, Ar is a heteroaryl group containing one or more nitrogen atoms as ring-constituting atoms and may have a substituent, R ₁ ~ R _Five Are each independently a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent, and R ₂ And R _Three May combine with each other to form a ring structure, and R _Four And R _Five May combine with each other to form a ring structure, m is an integer of 1 to 100, and n is an integer of 2 or more. )
[0018]
Y in the general formulas (1) to (4) represents a single bond or a linking group with a polymer main chain skeleton. When Y is a single bond, a heteroaryl group, a polyalkyleneoxy group, etc. described later are directly bonded to the polymer main chain skeleton, and when Y is a linking group, a heteroaryl group, a polyalkyleneoxy group, etc. described below are The polymer main chain skeleton is bonded through the linking group Y described in (1).
Examples of the linking group represented by Y include a divalent hydrocarbon group which may have a group containing one or more heteroatoms selected from the group consisting of an oxygen atom, a nitrogen atom and a sulfur atom, The divalent hydrocarbon group may be substituted or unsubstituted.
The linking group represented by Y is preferably a divalent hydrocarbon group having 1 to 30 carbon atoms having at least one of an ester structure, an amide structure, a urea structure, a phenylene structure, an ether structure, a thioether structure, and the like. More preferably, it is a C1-C30 bivalent hydrocarbon group having at least one ester structure or amide structure.
[0019]
Ar in the general formula (1) is a heteroaryl group containing one or more nitrogen atoms as ring constituent atoms, preferably a heteroaryl group having 3 to 30 carbon atoms, and these heteroaryl groups are substituted. Or may not be substituted.
The heteroaryl group is not particularly limited, and specifically, for example, pyrrole, pyridine, pyrazole, imidazole, triazole, tetrazole, isoxazole, oxazole, isothiazole, thiazole, which may have a substituent. , Thiadiazole, indole, carbazole, azaindole, indazole, benzimidazole, benzotriazole, benzisoxazole, benzoxazole, benzothiazole, purine, pyridazine, pyrimidine, pyrazine, triazine, quinoline, isoquinoline, acridine, phthalazine, quinazoline, quinoxaline, Binds to any one of the ring member atoms (for example, carbon atom, nitrogen atom, etc.) constituting the nitrogen-containing heteroaromatic ring such as naphthyridine, phenanthroline, pteridine, etc. It can be exemplified by the dividing monovalent group one of atom.
Among these, monovalent groups having pyrrole, pyridine and imidazole as a mother skeleton are more preferable.
[0020]
R in the general formulas (2) to (4) ₁ ~ R _Five Each independently represents a hydrogen atom or an optionally substituted hydrocarbon group having 1 to 30 carbon atoms, and R in the general formula (3) ₂ And R _Three May combine with each other to form a ring structure, and R in the general formula (4) _Four And R _Five May be bonded to each other to form a ring structure.
The hydrocarbon group having 1 to 30 carbon atoms is not particularly limited, and for example, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a hetero atom selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom is 1 Heteroaryl group containing more than one is mentioned.
[0021]
Specific examples of the alkyl group include, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group. Group, hexadecyl group, octadecyl group, eicosyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl And a linear, branched or cyclic alkyl group such as a group, cyclopentyl group, cyclohexyl group, 1-adamantyl group and 2-norbornyl group.
[0022]
Specific examples of the alkenyl group include linear groups such as a vinyl group, a 1-propenyl group, a 1-butenyl group, a 1-methyl-1-propenyl group, a 1-cyclopentenyl group, and a 1-cyclohexenyl group. , Branched or cyclic alkenyl groups.
[0023]
Specific examples of the alkynyl group include alkynyl groups such as ethynyl group, 1-propynyl group, 1-butynyl group, and 1-octynyl group.
Examples of the aryl group include a phenyl group, a group in which two to four benzene rings form a condensed ring, and a group in which a benzene ring and an unsaturated five-membered ring form a condensed ring. Examples include aryl groups such as phenyl group, naphthyl group, anthryl group, phenanthryl group, indenyl group, acenaphthenyl group, fluorenyl group, and pyrenyl group.
[0024]
Examples of the heteroaryl group containing one or more heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom include one or more heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom Examples include a heteroaryl group formed by removing one hydrogen atom on a heteroaromatic ring.
Specific examples of the heteroaryl group containing one or more heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom include pyrrole, furan, thiophene, pyrazole, imidazole, triazole, oxazole and isoxazole. , Oxadiazole, thiazole, thiadiazole, indole, carbazole, benzofuran, dibenzofuran, thianaphthene, dibenzothiophene, indazolebenzimidazole, anthranyl, benzisoxazole, benzoxazole, benzothiazole, purine, pyridine, pyridazine, pyrimidine, pyrazine, triazine, 1 hydrogen atom such as quinoline, acridine, isoquinoline, phthalazine, quinazoline, quinoxaline, naphthyridine, phenanthroline, pteridine There may be mentioned those obtained by dividing.
[0025]
R above ₁ ~ R _Five The hydrocarbon group may contain one or more heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom. For example, in the case of the alkyl group, specific examples include an alkoxyalkyl group, an alkylthioalkyl group, and an aminoalkyl group.
[0026]
R above ₁ ~ R _Five One or more of these hydrocarbon groups may be substituted with any substituent.
Examples of the substituent include a monovalent nonmetallic atomic group excluding hydrogen. Specifically, for example, halogen atom (F, Br, Cl, I), hydroxy 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 group, arylsulfoxy group, acylthio group, An acylamino group, an N-alkylacylamino group, - aryl acyl amino group, and the like.
[0027]
Similarly, for example, ureido group, N′-alkylureido group, N ′, N′-dialkylureido 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-arylurea Id 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, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfo group SO _Three H) and its conjugate base group, alkoxysulfonyl group, aryloxysulfonyl group and the like.
[0028]
Further, similarly, for example, 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 conjugate base group, N-arylsulfonylsulfamoyl group (SO ₂ NHSO ₂ (Aryl)) and its conjugate base group, N-alkylsulfonylcarbamoyl group (CONHSO) ₂ (Alkyl)) and its conjugate base group, N-arylsulfonylcarbamoyl group (CONHSO) ₂ (Aryl)) and its conjugate base group, trialkoxysilyl group (Si (O-alkyl)) _Three ), Tris (aryloxy) silyl group (Si (O-aryl)) _Three ), Hydroxysilyl group (Si (OH) _Three ) And its conjugate base group, phosphono group (PO _Three H ₂ ) And conjugated base groups thereof, dialkylphosphono groups (PO _Three (Alkyl) ₂ ), Diarylphosphono group (PO _Three (Aryl) ₂ ), Alkylarylphosphono groups (PO _Three (Alkyl) (aryl)), monoalkylphosphono group (PO _Three H (alkyl)) and its conjugate base group, monoarylphosphono group (PO _Three H (aryl)) and its conjugate base group, phosphonooxy group (OPO) _Three H ₂ ) And its conjugate base group, dialkylphosphonooxy group (OPO) _Three (Alkyl) ₂ ), Diarylphosphonooxy group (OPO) _Three (Aryl) ₂ ), Alkylarylphosphonooxy group (OPO) _Three (Alkyl) (aryl)), monoalkylphosphonooxy group (OPO) _Three H (alkyl)) and its conjugate base group, monoarylphosphonooxy group (OPO) _Three H (aryl)) and its conjugate base group, cyano group, nitro group, aryl group, alkyl group, alkenyl group, alkynyl group and the like.
[0029]
The functional group represented by the general formula (1) is a functional group formed by arbitrarily combining each of the groups exemplified as Y (single bond or linking group) and Ar.
[0030]
The functional group represented by the general formula (2) is the above-described Y (single bond or linking group), R ₁ The functional groups formed by arbitrarily combining the groups exemplified in (1), m and n. As a particularly preferred structure, Y is a group having an ester structure, and R ₁ Is a methyl group.
Here, m is an integer of 1 to 100, preferably an integer of 4 to 90, more preferably an integer of 8 to 50. When m is an integer of 1 to 100, the molecular weight is in a suitable range, the production of the compound having the functional group is easy, the number of interaction sites is large, and the water-insoluble and alkali-soluble resin can be efficiently interacted.
Moreover, n is an integer greater than or equal to 2, Preferably it is an integer of 2-4. n may be a combination of two or more different integers. In this case, when the functional group represented by the general formula (2) is, for example, two different integers, the following general formula (5) It is represented by The same applies when n is 3 or more.
[0031]
[Formula 4]
(In General Formula (5), Y represents a single bond or a linking group to a polymer main chain skeleton, and R ₁ Is a hydrogen atom or an optionally substituted hydrocarbon group having 1 to 30 carbon atoms, q and s are each independently an integer of 1 to 99, q + s is 100 or less, p and r Are different integers of 2 or more. )
Where Y and R ₁ The same as described above. The preferred range of q + s is the same as that described for m. Each of p and r is preferably a different integer of 2-4.
[0032]
The functional group represented by the general formula (3) is the above-described Y (single bond or linking group), R ₂ And R _Three It is a functional group formed by arbitrarily combining the groups exemplified in.
R ₂ And R _Three Is preferably a hydrogen atom or an alkyl or aryl group having 1 to 30 carbon atoms which may have a substituent. ₂ And R _Three May be bonded to each other to form a ring structure.
R ₂ And R _Three The ring structure formed by bonding to each other is not particularly limited, but a structure represented by the following general formula (6) is preferable.
[0033]
[Chemical formula 5]
(In general formula (6), Z ₁ Is a hydrocarbon group containing one or more heteroatoms selected from the group consisting of oxygen atoms, nitrogen atoms and sulfur atoms. )
[0034]
The hydrocarbon group Z ₁ Is not particularly limited, and may be any hydrocarbon group as long as the above conditions are satisfied. In addition, the hydrocarbon group Z ₁ May have a substituent that is not particularly limited.
The structure represented by the general formula (6) is preferably a 4- to 8-membered ring structure, and more specifically, the ring structure which may have a substituent shown below. More preferred.
[0035]
[Chemical 6]
[0036]
The functional group represented by the general formula (4) is the above-described Y (single bond or linking group), R _Four And R _Five It is a functional group formed by arbitrarily combining the groups exemplified in.
R _Four Is preferably an alkyl group having 1 to 30 carbon atoms which may have a substituent, as described above, and R _Five Among the above, is preferably a hydrogen atom.
R _Four And R _Five The ring structure formed by bonding to each other is not particularly limited, but a structure represented by the following general formula (7) is preferable.
[0037]
[Chemical 7]
(In the general formula (7), Z ₂ Is a hydrocarbon group containing one or more heteroatoms selected from the group consisting of oxygen atoms, nitrogen atoms and sulfur atoms. )
[0038]
The hydrocarbon group Z ₂ Is not particularly limited, and may be any hydrocarbon group as long as the above conditions are satisfied. In addition, the hydrocarbon group Z ₂ May have a substituent that is not particularly limited.
The structure represented by the general formula (7) is preferably a 4- to 8-membered ring structure, and more specifically, the ring structure which may have a substituent shown below. More preferred.
[0039]
[Chemical 8]
[0040]
Specific examples of the functional groups represented by the general formulas (1) to (4) include, for example, an ethylenically unsaturated bond described later and a monomer unit having the functional group, and a water-insoluble and alkali-soluble resin described later. The functional group illustrated by the polymer which has a functional group which can interact is mentioned, However, It is not limited to these.
[0041]
The compound contained in the intermediate layer of the present invention is a compound having the functional group described above. The compound may have one type or two or more types of the functional group.
The compound is not particularly limited as long as it has the functional group, but the interaction between the functional group and the water-insoluble and alkali-soluble resin works uniformly on the entire intermediate layer, thereby improving the printing durability. A high molecular compound (polymer) is preferred.
That is, the compound is preferably a polymer having a functional group capable of interacting with the water-insoluble and alkali-soluble resin, and at least one selected from the group consisting of the general formulas (1) to (4). A polymer having a functional group in the side chain is more preferable.
[0042]
The main chain of the polymer is not particularly limited, but has an ethylenically unsaturated bond such as a styrene group, a vinyl group, an allyl group, or a (meth) acryl group from the viewpoint of ease of synthesis and availability of raw materials. The main chain is preferably obtained by a polymerization reaction of monomers.
Further, the side chain other than the functional group in the polymer is not particularly limited, but it has other substituents such as an acid group for the purpose of improving developability and adjusting the strength of the interaction. preferable.
[0043]
The method for introducing the functional group into the polymer is not particularly limited. For example, the functional group is introduced into a monomer unit having an ethylenically unsaturated bond and, if necessary, radical polymerization, cationic polymerization, anion with other monomer components. Examples thereof include polymerization such as polymerization, a method of introducing by a condensation reaction, and a method of introducing by a polymer reaction between the polymer and the compound having the functional group.
[0044]
From the viewpoint of difficulty in introducing the functional group, a method of polymerizing or condensing a monomer unit having an ethylenically unsaturated bond and the functional group is preferable.
Specific examples of the monomer unit having an ethylenically unsaturated bond and the functional group used in the method include the monomers shown below.
The monomer units are not limited to the monomer units shown below.
[0045]
[Chemical 9]
[0046]
[Chemical Formula 10]
[0047]
Embedded image
[0048]
The monomer unit having the ethylenically unsaturated bond and the functional group may have other substituents such as the following acid groups.
[0049]
For the purpose of improving developability and adjusting the strength of the interaction, the polymer is a monomer having the ethylenically unsaturated bond and the functional group together with a monomer component having other substituents such as an acid group. A polymer obtained by polymerization or condensation is more preferred.
The monomer component is not particularly limited, and examples thereof include a monomer having an acid group and an ethylenically unsaturated bond such as a vinyl group, an allyl group, or a (meth) acryl group, or other monomers.
The acid group is not particularly limited, and examples thereof include -COOH and -SO. _Three H, -OSO _Three H, -PO _Three H ₂ , -OPO _Three H ₂ , -CONHSO ₂ , -SO ₂ NHSO ₂ Among these, among these, carboxylic acid (-COO), sulfonic acid (-SO _Three H), phosphonic acid (-PO _Three H ₂ Is particularly preferred.
Specific examples of monomers having carboxylic acid, sulfonic acid, and phosphonic acid groups are shown below.
[0050]
The monomer having a carboxylic acid group is not particularly limited as long as it is a polymerizable compound having a carboxylic acid group and an ethylenically unsaturated bond in its structure.
Preferable examples of the monomer having a carboxylic acid group include compounds represented by the following general formula (8).
[0051]
Embedded image
[0052]
In general formula (8), R ¹ ~ R ^Four Each independently represents a hydrogen atom, an alkyl group, or an organic group represented by the following general formula (9); ¹ ~ R ^Four Is at least one organic group represented by the following general formula (9).
Here, from the viewpoint of copolymerization and raw material availability when producing a specific vinyl polymer, R ¹ ~ R ^Four It preferably has 1 to 2 organic groups represented by the following general formula (9), and particularly preferably 1 organic group. From the viewpoint of the flexibility of the specific vinyl polymer obtained as a result of the polymerization, R ¹ ~ R ^Four Among them, in addition to the organic group represented by the following general formula (9), an alkyl group or a hydrogen atom is preferable, and a hydrogen atom is particularly preferable.
For the same reason, R ¹ ~ R ^Four When is an alkyl group, it is preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group.
[0053]
Embedded image
[0054]
In General Formula (9), X represents a single bond, an alkylene group, an arylene group which may have a substituent, or any one of the following structural formulas (i) to (iii). From the viewpoint of polymerizability, availability, etc., a single bond, an arylene group represented by a phenylene group, or one represented by the following structural formula (i) is preferable, and an arylene group or the following structural formula (i) is preferred. More preferred are those represented by the following structural formula (i).
[0055]
Embedded image
[0056]
In the structural formulas (i) to (iii), Z represents a divalent linking group, and Ar represents an arylene group which may have a substituent. Z is preferably an alkylene group having 1 to 16 carbon atoms or a single bond. Methylene (—CH in the alkylene group) ₂ -) May be substituted with an ether bond (-O-), a thioether bond (-S-), an ester bond (-COO-), an amide bond (-CONR-; R is a hydrogen atom or an alkyl group). As the bond substituting the methylene group, an ether bond or an ester bond is particularly preferable.
Among such divalent linking groups, particularly preferred specific examples are listed below.
[0057]
Embedded image
[0058]
Particularly preferred examples of the monomer having a carboxylic acid group represented by the general formula (8) are shown below, but the present invention is not limited thereto.
[0059]
Embedded image
[0060]
The monomer having a sulfonic acid group is not particularly limited as long as it is a polymerizable compound having a sulfonic acid group and an ethylenically unsaturated bond in its structure.
[0061]
Preferable specific examples of the monomer having a sulfonic acid group include 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, and 4-styrenesulfonic acid.
[0062]
The monomer having a phosphonic acid group is not particularly limited as long as it is a polymerizable compound having a phosphonic acid group and an ethylenically unsaturated bond in its structure.
Preferable specific examples of the monomer having a phosphonic acid group include acid phosphoxyethyl methacrylate, 3-chloro-2-acid phosphooxypropyl methacrylate, and acid phosphoxypolyoxyethylene glycol monomethacrylate.
[0063]
Among the acid groups described above, the carboxylic acid group and phosphonic acid group exhibit the interaction with the surface of the lithographic printing plate support, and thus have the functions of providing adhesion to the support and developing solution solubility. Therefore, it is preferable to use the monomer having these acid groups together with the monomer having the ethylenically unsaturated bond and the functional group.
[0064]
In addition to the monomer having the ethylenically unsaturated bond and the functional group and the monomer having an acid group copolymerized as necessary, for the purpose of enhancing the interaction with the support or the recording layer, etc. Other monomers may be used.
Although it does not specifically limit as another monomer, The monomer as described in the following (1)-(12) is mentioned preferably.
[0065]
(1) o-, m- or p-hydroxystyrene, o- or m-bromo-p-hydroxysterene, o- or m-chloro-p-hydroxyquinstyrene, o-, m- or p-hydroxyphenyl Acrylic esters, methacrylic esters and hydroxystyrenes having an aromatic hydroxyl group such as acrylate or methacrylate;
(2) Unsaturated sulfonamides such as o-aminosulfonylphenyl acrylate, m-aminosulfonylphenyl acrylate, p-aminosulfonylphenyl acrylate, 1- (3-aminosulfonylphenylnaphthyl) acrylate acrylic esters, o-amino Unsaturated sulfonamides such as sulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate, methacrylic acid esters of 1- (3-aminosulfonylphenylnaphthyl) methacrylate;
(3) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group, such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate;
[0066]
(4) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate, 2-acrylate (Substituted) acrylic acid esters such as chloroethyl, 4-hydroxybutyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate;
(5) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-methacrylic acid 2- (Substituted) methacrylate esters such as chloroethyl, 4-hydroxybutyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl methacrylate;
[0067]
(6) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether;
(7) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate;
(8) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene;
(9) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone;
(10) Olefins such as ethylene, propylene, isobutylene, butadiene, isoprene;
(11) Nitrile group-containing monomers such as acrylonitrile and methacrylonitrile
(12) Lactone group-containing monomers such as pantoyl lactone (meth) acrylate, α- (meth) acryloyl-γ-butyrolactone, β- (meth) acryloyl-γ-butyrolactone
[0068]
The polymer having a functional group capable of interacting with the water-insoluble and alkali-soluble resin may be a commercially available product or may be produced.
Manufacture is obtained by copolymerizing the monomer having the above functional group, and optionally the monomer having an acid group and other monomers in any combination. Examples of the copolymerization method include generally known suspension polymerization methods or solution polymerization methods. Further, the constitution of the copolymer may be any of a block copolymer, a random copolymer, and a graft copolymer.
In addition, the monomer which has the said functional group, the monomer which has an acid group, and another monomer may each be used 1 type, or may be used in combination of 2 or more type.
[0069]
An example of the manufacturing method of this polymer is shown.
For example, a monomer constituting the polymer and a polymerization initiator are mixed in a nitrogen atmosphere, and the reaction is preferably performed while heating. Thereafter, the reaction mixture is recrystallized, or the reaction mixture is reprecipitated, and the precipitated polymer is collected by filtration and dried to obtain the desired polymer. More specifically, it will be described later.
[0070]
The number of functional groups capable of interacting with the alkali-soluble resin in the compound (polymer) having functional groups capable of interacting with the water-insoluble and alkali-soluble resin thus obtained is important in forming the interaction. The content of the functional group of the polymer also depends on the strength of the functional group in the interaction, and in the case of a functional group that interacts strongly, the content is preferably small and weakly interacts. In the case of a functional group, a higher content is preferred. In general, the monomer having the functional group is more preferably 10 mol% or more, particularly preferably 40 mol% or more, based on the number of moles of all monomers.
The content of the monomer having an acid group is preferably 1 to 90 mol%, more preferably 20 to 80 mol%, more preferably 30 to 60 mol%, based on the number of moles of all monomers. It is particularly preferred.
As content of said other monomer, it is preferable that it is 30 mol% or less with respect to the number-of-moles of all the monomers.
[0071]
The weight average molecular weight of the polymer having a functional group capable of interacting with a water-insoluble and alkali-soluble resin is not particularly limited, but is preferably 500 to 1,000,000, for example, 1,000. More preferably, it is ˜500,000.
[0072]
A polymer having a functional group capable of interacting with the water-insoluble and alkali-soluble resin used in the intermediate layer of the present invention. Bill Typical high molecular compound (polymer) P-1 to P-5, P-15, P-17, P-18 Is shown below. P-6 to P-14, P-16, P-19, and P-20 are reference compounds. The composition ratio of the polymer structure represents a mole percentage.
[0073]
Embedded image
[0074]
Embedded image
[0075]
Embedded image
[0076]
The compound (polymer) used in the intermediate layer of the present invention has a functional group capable of interacting with a water-insoluble and alkali-soluble resin described later.
Here, as described above, whether or not the functional group can interact is determined by the functional group (for example, groups represented by the general formulas (1) to (5)) and the resin. Since the strength of the interaction when it is provided on the lithographic printing plate support as an intermediate layer varies depending on the amount of the functional group introduced into the compound as described above, It is preferable to evaluate the compound as it is.
[0077]
The method of evaluating the state when the compound is used can be confirmed, for example, by the following test method.
That is, 5 of m, p-cresol novolak resin (m / p ratio = 8/2 to 6/4, weight average molecular weight 2,000 to 20,000) generally used as a water-insoluble and alkali-soluble resin. A mass% methanol solution A is prepared. Further, a 5% by mass methanol solution B of the compound used in the intermediate layer of the present invention (the above functional group content is 30 to 100 mol%, and in the case of a polymer, the weight average molecular weight is 5,000 to 100,000) is prepared.
[0078]
Next, at 25 ° C., 1 mL of the solution A is added to 1 mL of the solution A and mixed. After 5 minutes, the mixed solution is visually confirmed, and the mixed solution becomes cloudy (the mixed solution is more than the original solution A or B). Or the formation of a white precipitate in the mixed solution or the formation of a gel in the mixed solution (to the extent that an insoluble gel solid can be confirmed). It is determined whether or not it is formed.
A case where any one of these phenomena is recognized and a polymer complex is formed is referred to as “a compound having a functional group capable of interacting with a water-insoluble and alkali-soluble resin” in the present invention.
[0079]
In the intermediate layer of the present invention, in addition to the compound having a functional group capable of interacting with the water-insoluble and alkali-soluble resin, ultraviolet light, visible light, infrared light is used for the purpose of improving the tone reproducibility of the lithographic printing plate. A substance that absorbs the like may be contained.
[0080]
In the intermediate layer of the present invention, a lithographic printing plate support to be described later is subjected to a hydrophilic treatment to form a hydrophilic layer, and then the intermediate layer coating solution is applied onto the hydrophilic layer by various methods. Can be provided. The method for providing the intermediate layer is not particularly limited, but representative examples include the following methods.
[0081]
For example, an intermediate layer coating solution in which each component used for the intermediate layer of the present invention is dissolved in an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof, or a mixed solvent of these organic solvent and water, The method of apply | coating on the hydrophilic layer provided on the support body for printing plates, and drying is mentioned.
In this method, an intermediate layer coating solution having a concentration of 0.005 to 10% by mass in total for each component used in the intermediate layer of the present invention is applied by means such as bar coater coating, spin coating, spray coating, curtain coating, or the like. do it.
[0082]
In addition to the coating method, for example, a method of immersing a lithographic printing plate support provided with a hydrophilic layer in the intermediate layer coating solution, followed by washing with water or air, and drying.
In this method, the concentration of the intermediate layer coating solution is adjusted to 0.005 to 20% by mass (preferably 0.01 to 10% by mass), and the immersion temperature is 0 to 70 ° C. (preferably 5 to 60 ° C.). The time is preferably 0.1 second to 5 minutes (preferably 0.5 to 120 seconds).
[0083]
The intermediate layer coating solution includes basic substances such as ammonia, triethylamine and potassium hydroxide, inorganic acids such as hydrochloric acid, phosphoric acid, sulfuric acid and nitric acid, organic sulfonic acids such as nitrobenzenesulfonic acid and naphthalenesulfonic acid, and phenylphosphonic acid The pH is adjusted with various organic acidic substances such as organic phosphonic acids such as benzoic acid, benzoic acid, coumaric acid and malic acid, and organic chlorides such as naphthalene sulfonyl chloride and benzene sulfonyl chloride. It can also be used by adjusting to pH 0-6.
[0084]
The coating amount after drying of the intermediate layer of the present invention thus provided is 1 to 100 mg / m. ² Is preferred, 2 to 70 mg / m ² It is more preferable that
[0085]
The compound having a functional group capable of interacting with the water-insoluble and alkali-soluble resin forms an interaction with the water-insoluble and alkali-soluble resin contained in the image recording layer, which will be described later, and provides strong adhesion to the image recording layer. It also suppresses the penetration of dampening water into the interface between the image recording layer and the intermediate layer. Therefore, the lithographic printing plate precursor provided with the intermediate layer of the present invention containing the compound is excellent in printing durability when used as a lithographic printing plate.
In particular, when the acid group is contained in the compound, interaction with an aluminum substrate and a hydrophilic layer, which will be described later, can be formed, and stain resistance can be further improved.
[0086]
[Support for lithographic printing plate]
Next, the lithographic printing plate support used in the present invention will be described.
The lithographic printing plate support used in the present invention is a lithographic printing plate support obtained by subjecting an aluminum plate to a hydrophilic treatment.
<Aluminum plate (rolled aluminum)>
The aluminum plate used in the present invention is selected from a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, or a plastic film on which aluminum is laminated or deposited. The trace amount of foreign elements contained in the aluminum plate is one or more selected from those listed in the periodic table of elements, and the content thereof is 0.001 to 1.5% by mass.
Typical examples of the different elements contained in the aluminum alloy include silicon, iron, nickel, manganese, copper, magnesium, chromium, zinc, bismuth, titanium, and vanadium. Usually, a conventionally known material described in Aluminum Handbook 4th Edition (1990, Light Metal Association), for example, JIS A1050 material, JIS A3005 material, JIS A1100 material, JIS A3004 material, internationally registered alloy 3103A, or In order to increase the tensile strength, an alloy in which 5% by mass or less of magnesium is added is used.
[0087]
In the present invention, it is also possible to use an aluminum plate manufactured by omitting the intermediate annealing treatment and / or soaking treatment from the DC casting method, and an aluminum plate manufactured by omitting the intermediate annealing treatment from the continuous casting method.
[0088]
The thickness of the aluminum plate is preferably 0.05 to 0.8 mm, and more preferably 0.1 to 0.6 mm.
[0089]
<Roughening treatment>
In the lithographic printing plate support used in the present invention, it is preferable that the aluminum plate is subjected to a roughening treatment to form an uneven shape on the surface of the aluminum plate.
This roughening process can be performed by arbitrarily selecting a roughening process that is normally performed. In the present invention, as a roughening method suitably performed,
A method of sequentially performing mechanical surface roughening treatment, alkali etching treatment, desmutting treatment with an acid and electrochemical surface roughening treatment using an electrolytic solution on an aluminum plate,
A method of performing mechanical surface roughening treatment, alkaline etching treatment, desmutting treatment with acid and electrochemical surface roughening treatment using different electrolytes a plurality of times on an aluminum plate,
A method of sequentially performing an alkali etching treatment, an acid desmutting treatment on an aluminum plate, and an electrochemical surface roughening treatment using an electrolytic solution,
A method of subjecting an aluminum plate to alkaline etching treatment, desmutting treatment with acid, and electrochemical surface roughening treatment using different electrolytes multiple times.
However, the present invention is not limited to these. In these methods, after the electrochemical roughening treatment, an alkali etching treatment and an acid desmutting treatment may be further performed.
[0090]
The conditions for these roughening treatments and the apparatus used are not particularly limited, and general conditions and apparatuses can be selected.
[0091]
<Anodizing treatment>
In the present invention, after the roughening treatment is performed on the aluminum plate, it is preferable to further perform anodizing treatment in order to increase the wear resistance of the surface of the aluminum plate.
Any electrolyte can be used as long as it can form a porous oxide film. In general, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixture thereof is used. The concentration of the electrolyte is appropriately determined depending on the type of electrolyte. The conditions of the anodizing treatment vary considerably depending on the electrolyte, so it is difficult to specify, but in general, the concentration of the electrolyte is 1 to 80% by mass, the liquid temperature is 5 to 70 ° C., and the current density is 1 to 60 A / dm. ² The voltage may be 1 to 100 V and the electrolysis time may be 10 to 300 seconds.
[0092]
In the present invention, after the anodic oxidation treatment, sealing treatment by a conventional method such as hot water treatment, sodium silicate treatment, immersion treatment with an aqueous solution containing an acetate or a hydrophilic polymer may be performed.
[0093]
<Hydrophilic treatment>
In the present invention, the aluminum plate is subjected to a hydrophilic treatment after the roughening treatment or after the roughening treatment and the anodizing treatment.
[0094]
Examples of the hydrophilization treatment include treatment with potassium fluorozirconate described in US Pat. No. 2,946,638 and phosphomolybdate described in US Pat. No. 3,201,247. Treatment, alkyl titanate treatment described in British Patent 1,108,559, polyacrylic acid treatment described in German Patent 1,091,433, German Patent 1,134, No. 093 and British Patent No. 1,230,447, polyvinylphosphonic acid treatment, Japanese Patent Publication No. 44-6409, phosphonic acid treatment, US Pat. No. 3,307,951 Phytic acid treatment described in the specification of JP, No. 58-16893 and JP-A No. 58-18291 Treatment with a salt of a molecular compound and a divalent metal, as described in US Pat. No. 3,860,426, hydrophilic cellulose (eg, zinc acetate) containing a water-soluble metal salt (eg, zinc acetate) Carboxymethyl cellulose) is provided with a subbing layer, and a water-soluble polymer having a sulfo group described in JP-A-59-101651.
[0095]
Further, phosphates described in JP-A No. 62-019494, water-soluble epoxy compounds described in JP-A No. 62-033692, and JP-A No. 62-097892 Phosphoric acid modified starch, diamine compounds described in JP-A-63-056498, inorganic or organic acids of amino acids described in JP-A-63-130391, JP-A-63-145092 Organic phosphonic acids containing a carboxy group or hydroxy group, compounds having an amino group and a phosphonic acid group described in JP-A-63-165183, and JP-A-2-316290 Specific carboxylic acid derivatives, phosphate esters described in JP-A-3-215095, JP-A-3-261592 Compounds having one amino group and one oxygen acid group of phosphorus described in the publication, phosphoric esters described in JP-A-3-215095, and JP-A-5-246171 Aliphatic or aromatic phosphonic acids such as phenylphosphonic acid, compounds containing S atoms such as thiosalicylic acid described in JP-A-1-307745, phosphorus described in JP-A-4-282737 Examples of the treatment include undercoating using a compound having a group of oxygen acids.
Further, coloring with an acid dye described in JP-A-60-64352 can also be performed.
[0096]
Hydrophilicity can also be achieved by dipping in an aqueous solution of an alkali metal silicate such as sodium silicate or potassium silicate, or by applying a hydrophilic vinyl polymer or hydrophilic compound to form a hydrophilic subbing layer. It is preferable to carry out the treatment.
[0097]
Hydrophilization treatment with an aqueous solution of an alkali metal silicate such as sodium silicate and potassium silicate is described in US Pat. No. 2,714,066 and US Pat. No. 3,181,461. It can be performed according to methods and procedures.
Specifically, the treatment conditions are not particularly limited. For example, the treatment conditions are immersed in an aqueous solution of alkali metal silicate having a concentration of 0.5 to 5.0 mass% at a temperature of 20 to 100 ° C. for 1 to 100 seconds. And then washed with running water. The concentration of the aqueous solution is more preferably 1.0 to 3.0% by mass, the more preferable immersion treatment temperature is 30 to 90 ° C., the still more preferable immersion treatment temperature is 30 to 80 ° C., and the more preferable immersion time is 3 to 3%. 20 seconds.
[0098]
Examples of the alkali metal silicate include sodium silicate, potassium silicate, and lithium silicate. The aqueous solution of alkali metal silicate may contain an appropriate amount of sodium hydroxide, potassium hydroxide, lithium hydroxide or the like.
The aqueous solution of alkali metal silicate may contain an alkaline earth metal salt or a Group 4 (Group IVA) metal salt. Examples of the alkaline earth metal salt include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate; sulfates; hydrochlorides; phosphates; acetates; oxalates; Examples of Group 4 (Group IVA) metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride. And zirconium tetrachloride. These alkaline earth metal salts and Group 4 (Group IVA) metal salts are used alone or in combination of two or more.
[0099]
The amount of Si adsorbed by the alkali metal silicate treatment can be measured by a fluorescent X-ray analyzer, and the amount of adsorption is about 1.0 to 15.0 mg / m. ² Is preferred. As a result, a lithographic printing plate precursor excellent in all of sensitivity, printing durability and ink entanglement can be obtained.
By this alkali metal silicate treatment, the effect of improving the dissolution resistance to the alkaline developer on the surface of the lithographic printing plate support is obtained, the dissolution of the aluminum component into the developer is suppressed, and the developer fatigue It is possible to reduce the occurrence of development residue due to the above.
[0100]
The hydrophilic treatment by forming a hydrophilic undercoat layer can also be performed according to the conditions and procedures described in JP-A Nos. 59-101651 and 60-149491.
Examples of the hydrophilic vinyl polymer used in this method include polyvinyl sulfonic acid, sulfo group-containing vinyl polymerizable compounds such as p-styrene sulfonic acid having a sulfo group, and ordinary vinyl polymerization such as (meth) acrylic acid alkyl ester. And a copolymer with a functional compound. Moreover, as a hydrophilic compound used for this method, for example, —NH ₂ And a compound having at least one selected from the group consisting of a group, a -COOH group and a sulfo group.
[0101]
In this way, a lithographic printing plate support subjected to the hydrophilic treatment used in the present invention is obtained.
[0102]
[Lithographic printing plate precursor]
A support for a lithographic printing plate subjected to a hydrophilization treatment used in the present invention as described above is obtained. After providing the intermediate layer of the present invention, an infrared absorbing dye and a water-insoluble and alkali-soluble material are formed on the intermediate layer. A lithographic printing plate precursor according to the invention is obtained by providing a positive heat-sensitive layer containing a resin and increasing the solubility in an alkaline aqueous solution by heating.
[0103]
<Positive thermosensitive layer>
The positive thermosensitive layer may be a single layer or a multilayer thermosensitive layer composed of two or more layers. In addition to the heat-sensitive layer, a layer having functions such as surface protection and oxygen blocking can be provided.
Hereinafter, the case where the heat-sensitive layer is composed of a single layer will be described in <Thermal-sensitive layer 1>, and the case where the heat-sensitive layer is a multilayer heat-sensitive layer composed of two layers will be described in <Thermal-sensitive layer 2>.
[0104]
<Thermosensitive layer 1>
The heat-sensitive layer 1 used in the lithographic printing plate precursor according to the invention is a heat-sensitive layer composed of a single layer that is alkali-solubilized by heating. The heat-sensitive layer 1 preferably has a structure in which the alkali-solubility on the aluminum support side is higher than the solubility on the surface side, particularly after the application of a single composition coating liquid. Those having the above structure by phase separation are preferred.
The heat-sensitive layer 1 contains a positive photosensitive composition for infrared laser (hereinafter, also simply referred to as “photosensitive composition”).
The positive photosensitive composition for infrared laser contained in the heat-sensitive layer contains at least (A) a water-insoluble and alkali-soluble resin (hereinafter also referred to as “alkali-soluble resin”), and (B) a compatibility with the alkali-soluble resin. And (C) an infrared-absorbing dye (in the present invention, “photothermal conversion that absorbs infrared rays and generates heat”, while reducing the solubility of the resin in an alkaline aqueous solution and reducing the solubility-reducing action by heating. (Also referred to as “agent”) and, if necessary, (D) other components.
[0105]
(A) Alkali-soluble resin
The alkali-soluble resin used in the present invention is not particularly limited as long as it is a resin that is insoluble in water and soluble in an alkaline aqueous solution, and conventionally known resins can be used. Since the heat-sensitive layer used in the present invention contains an alkali-soluble resin, it has a property of dissolving when contacted with an alkaline developer. As the alkali-soluble resin, it is preferable to use a homopolymer, a copolymer or a mixture of monomers containing acidic groups in the main chain and / or side chain in the polymer.
Among these, those having the functional groups listed in (1) to (6) described later in the main chain and / or side chain in the polymer are preferable from the viewpoint of solubility in an alkaline solution and expression of dissolution inhibiting ability. In the present invention, the resin interacts with the functional group of the intermediate layer to form a complex. Among these preferable alkali-soluble resins, those having (1) a phenolic hydroxyl group in the main chain and / or side chain in the polymer are preferable from the viewpoint of high ability to form a complex with the functional group of the intermediate layer.
Examples of the alkali-soluble resin include the following, but the present invention is not limited to these.
[0106]
(1) Resin having phenolic hydroxyl group (—Ar—OH)
In the chemical formula (1), Ar represents a divalent aryl linking group which may have a substituent.
Examples of the alkali-soluble resin having a phenolic hydroxyl group include the following.
For example, a condensation polymer of phenol and formaldehyde, phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin, phenol / cresol (m-, p- and m- / Any of p-mixing may be used.) Novolak resins such as mixed formaldehyde resins and pyrogallol acetone resins may be mentioned.
Furthermore, the copolymer which copolymerized the compound (polymerizable monomer) which has a phenolic hydroxyl group in a side chain can also be mentioned.
Examples of the polymerizable monomer having a phenolic hydroxyl group include acrylamide, methacrylamide, acrylic acid ester, methacrylic acid ester, and hydroxystyrene having a phenolic hydroxyl group.
[0107]
In addition, as an alkali-soluble resin having a phenolic hydroxyl group, a polycondensation product of t-butylphenol and formaldehyde as described in US Pat. No. 4,123,279, octylphenol and formaldehyde A polycondensation product of phenol and formaldehyde having an alkyl group having 3 to 8 carbon atoms as a substituent, such as a polycondensation polymer, on the aromatic ring described in Japanese Patent Application Laid-Open No. 2000-241972 proposed by the present inventors Examples include alkali-soluble resins having a phenol structure having an electron-withdrawing group.
[0108]
In the present invention, among these alkali-soluble resins having a phenolic hydroxyl group, phenol, o from the viewpoint of interaction with the compound having the functional group used in the intermediate layer, film properties as a heat-sensitive layer, and the like. Preferred are polycondensates of phenols such as cresol, m-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol and resorcinol with aldehydes or ketones such as formaldehyde, acetaldehyde and propionaldehyde. In particular, the mixing ratio of m-cresol: p-cresol: 2,5-xylenol: 3,5-xylenol: resorcinol is 40 to 100: 0 to 50: 0 to 20: 0 to 20: 0 in molar ratio. 20 mixed phenols or phenol: m-cresol: p-cresol In case the ratio is the molar ratio of 0 to 100: 1 to 70: 1 to 60 and mixed phenols, polycondensate of formaldehyde is preferred.
[0109]
In the present invention, examples of the alkali-soluble resin that is preferably used other than the alkali-soluble resin having a phenolic hydroxyl group include, for example, alkali-soluble resins having a group that expresses alkali-solubility, such as the following (2) to (6). Resin.
[0110]
(2) Sulfonamide group (—SO ₂ NH-R)
(3) Substituted sulfonamide acid group (hereinafter referred to as “active imide group”)
(-SO ₂ NHCOR, -SO ₂ NHSO ₂ R, -CONHSO ₂ R)
(4) Carboxylic acid group (—CO ₂ H)
(5) Sulfonic acid group (-SO _Three H)
(6) Phosphate group (-OPO _Three H ₂ )
In the above (2) to (6), R represents a hydrocarbon group which may have a substituent.
[0111]
(2) The alkali-soluble resin having a sulfonamide group includes, for example, a resin obtained by homopolymerizing a polymerizable monomer having a sulfonamide group or copolymerizing the monomer with another polymerizable monomer. . Examples of the polymerizable monomer having a sulfonamide group include a sulfonamide group —NH—SO in which at least one hydrogen atom is bonded to a nitrogen atom in one molecule. ₂ -And a polymerizable monomer comprising a low molecular compound having at least one polymerizable unsaturated bond. Among them, a low molecular compound having an acryloyl group, an allyl group or a vinyloxy group and a mono-substituted aminosulfonyl group or a substituted sulfonylimino group is preferable. Examples of such polymerizable monomers include polymerizable monomers represented by the following general formulas (I) to (V).
[0112]
Embedded image
[0113]
Where X ¹ And X ² Are —O— or —NR, respectively. ₇ -Is shown. R ₁ And R _Four Are each a hydrogen atom or —CH _Three Represents. R ₂ , R _Five , R ₉ , R ₁₂ And R ₁₆ Represents an alkylene group having 1 to 12 carbon atoms, a cycloalkylene group, an arylene group or an aralkylene group, each of which may have a substituent. R _Three , R ₇ And R ₁₃ Each represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group, each optionally having a substituent. R ₆ And R ₁₇ Represents an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group, each optionally having a substituent. R ₈ , R _Ten And R ₁₄ Are each a hydrogen atom or —CH _Three Represents. R ₁₁ And R ₁₅ Each represents a single bond or an alkylene group having 1 to 12 carbon atoms, a cycloalkylene group, an arylene group or an aralkylene group which may have a substituent. Y ¹ And Y ² Each represents a single bond or —CO—.
[0114]
Of the compounds represented by the general formulas (I) to (V), m-aminosulfonylphenyl methacrylate, N- (p-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) acrylamide and the like are preferable. Can be used.
[0115]
(3) The alkali-soluble resin having an active imide group preferably has an active imide group represented by the following formula in the molecule, and this resin has an active imide group represented by the following formula in one molecule. And a resin obtained by homopolymerizing a polymerizable monomer composed of a low molecular compound each having one or more polymerizable unsaturated bonds, or copolymerizing the monomer with another polymerizable monomer.
[0116]
Embedded image
[0117]
As such a polymerizable monomer, specifically, N- (p-toluenesulfonyl) methacrylamide, N- (p-toluenesulfonyl) acrylamide and the like can be preferably used.
[0118]
(4) As the alkali-soluble resin having a carboxylic acid group, for example, a polymerizable monomer comprising a low molecular compound having at least one carboxylic acid group and polymerizable unsaturated bond in the molecule is homopolymerized, or A resin obtained by copolymerizing the monomer with another polymerizable monomer can be exemplified.
(5) As the alkali-soluble polymer having a sulfonic acid group, for example, a polymerizable monomer comprising a low molecular compound having at least one sulfonic acid group and a polymerizable unsaturated bond in the molecule is homopolymerized, or Examples thereof include a resin obtained by copolymerizing the monomer with another polymerizable monomer.
(6) As an alkali-soluble resin having a phosphoric acid group, for example, a polymerizable monomer consisting of a low molecular compound having at least one phosphoric acid group and a polymerizable unsaturated bond in the molecule is homopolymerized, or A resin obtained by copolymerizing the monomer with another polymerizable monomer can be exemplified.
[0119]
The alkali-soluble resin in the present invention is preferably a polymer having (1) a phenolic hydroxyl group, but is selected from the above (1) polymerizable monomer having a phenolic hydroxyl group and the above (2) to (6). It may be a copolymer obtained by copolymerizing a polymerizable monomer having an acidic group. In this case, the blending mass ratio of (1) the polymerizable monomer having a phenolic hydroxyl group and the polymerizable monomer having an acidic group selected from (2) to (6) is in the range of 99: 1 to 5:95. Some are preferable, and those in the range of 90:10 to 15:85 are more preferable.
[0120]
When the alkali-soluble resin is a copolymer of a polymerizable monomer having an acidic group selected from the above (1) and (2) to (6) and another polymerizable monomer, the above (1) and ( The polymerizable monomer having an acidic group selected from 2) to (6) is preferably contained in the copolymer in an amount of 10 mol% or more, more preferably 20 mol% or more. If it is less than 10 mol%, the solubility in an alkaline solution tends to be insufficient, such being undesirable.
[0121]
As said other polymerizable monomer, although the monomer quoted to following (1)-(12) can be used, for example, it is not limited to these.
(1) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.
(2) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, glycidyl acrylate, N-dimethylaminoethyl Alkyl acrylates such as acrylates;
(3) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl Alkyl methacrylate such as methacrylate.
[0122]
(4) Acrylamide, methacrylamide, N-methylolacrylamide, N-ethylacrylamide, N-hexylmethacrylamide, N-cyclohexylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide, N-ethyl- Acrylamide and methacrylamide such as N-phenylacrylamide.
(5) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether.
(6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate.
[0123]
(7) Styrenes such as styrene, α-methylstyrene, methylstyrene, and chloromethylstyrene.
(8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.
(9) Olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene.
(10) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile and the like.
(11) Unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide.
(12) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride and itaconic acid.
[0124]
As a copolymerization method of the alkaline water-soluble resin, a conventionally known graft copolymerization method, block copolymerization method, random copolymerization method, or the like can be used.
[0125]
In the present invention, the alkali-soluble resin preferably has a weight average molecular weight of 500 or more from the viewpoint of image forming property. More preferably, the weight average molecular weight is 1,000 to 700,000. Moreover, it is preferable that the number average molecular weight is 500 or more, and it is more preferable that it is 750-650,000.
The dispersity (weight average molecular weight / number average molecular weight) is preferably 1.1 to 10.
[0126]
These alkali-soluble resins may be used alone or in combination of two or more, and are preferably 30 to 98% by mass, more preferably 40 to 95% by mass in the total solid content of the heat-sensitive layer. Used in addition amount. When the addition amount of the alkali-soluble resin is less than 30% by mass, the durability of the heat-sensitive layer is deteriorated, and when it exceeds 98% by mass, it is not preferable in terms of both sensitivity and image formability.
[0127]
A preferred example of the alkali-soluble resin is a novolac resin.
The novolak resin is not particularly limited, and examples thereof include phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin, phenol / cresol (m-, p-, o-, Any of m- / p-mixing, m- / o-mixing, and o- / p-mixing may be used.) Mixed formaldehyde resin may be mentioned. These may be used alone or in combination of two or more.
[0128]
In the present invention, it is one of the preferred embodiments to contain the novolak resin as a binder. However, in this embodiment as well, other water-insoluble and alkali-soluble resins can be used in combination. Examples of such resins include phenol-modified xylene resins, polyhydroxystyrene, polyhalogenated hydroxystyrene, acrylic resins having a phenolic hydroxyl group as described in JP-A No. 51-34711, Examples thereof include acrylic resins and urethane resins having a sulfonamide group described in Japanese Patent No. 866. Examples of the urethane resin include, for example, JP-A-63-124047, JP-A-63-261350, JP-A-63-287742, JP-A-63-287943, JP-A-63-287944. JP, 63-287946, 63-287947, 63-287948, 63-287949, 1-134354 and 1 Preferred examples include those described in JP-A-255854. These may be used alone or in combination of two or more.
[0129]
(B) A compound that reduces the solubility of the resin in an alkaline aqueous solution by being compatible with the alkali-soluble resin and reduces the solubility-reducing action by heating.
This component (B) has good compatibility with the alkali-soluble resin (A) due to the action of the hydrogen bonding functional group present in the molecule, and can form a uniform coating solution. The compound which has a function which suppresses alkali solubility of this resin by interaction with a component is pointed out.
In addition, this compound loses its solubility-reducing action by heating, but when the component (B) is a compound that decomposes by heating, sufficient energy for decomposition is not imparted depending on conditions such as laser output and irradiation time. In addition, since the decrease in solubility suppressing action becomes insufficient and the sensitivity may be lowered, the thermal decomposition temperature of the component (B) is preferably 150 ° C. or higher.
[0130]
As a suitable (B) component used for this invention, the compound which interacts with said (A) components, such as a sulfone compound, ammonium salt, phosphonium salt, an amide compound, is mentioned, for example. As described above, the component (B) should be appropriately selected in consideration of the interaction with the component (A). Specifically, for example, when a novolak resin is used alone as the component (A) Cyanine dye A and the like exemplified later are preferably used.
[0131]
The blending ratio of the component (A) and the component (B) is usually preferably in the range of 99/1 to 75/25. Within this range, the interaction with the component (A) is sufficient, alkali solubility can be inhibited, and good image formation can be achieved. In addition, the interaction is large and the sensitivity is high.
[0132]
(C) Infrared absorbing dye (photothermal conversion agent that generates heat by absorbing infrared rays)
In the present invention, the photothermal conversion agent that absorbs infrared rays and generates heat has a light absorption region in the infrared region of 700 nm or more, preferably 750 to 1200 nm, and expresses light / heat conversion ability in light in this range of wavelengths. Refers to things. Specifically, various pigments or dyes that absorb light in this wavelength range and generate heat can be used. Examples of the pigment include a commercially available pigment or color index (CI) manual, “Latest Pigment Handbook” (edited by the Japan Pigment Technical Association, published in 1977), “Latest Pigment Applied Technology” (published by CMC, published in 1986), and “ The pigments described in “Printing Ink Technology”, published by CMC Publishing, 1984) can be used.
[0133]
Examples of the pigment include black pigment, yellow pigment, orange pigment, brown pigment, red pigment, purple pigment, blue pigment, green pigment, fluorescent pigment, metal powder pigment, and polymer-bonded dye. 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 A quinophthalone pigment, a dyed lake pigment, an azine pigment, a nitroso pigment, a nitro pigment, a natural pigment, a fluorescent pigment, an inorganic pigment, or carbon black can be used.
[0134]
These pigments may be used without surface treatment or may be used after surface treatment. Examples of the surface treatment method include a method of surface coating with a resin or wax, a method of attaching a surfactant, and a method of bonding a reactive substance (eg, silane coupling agent, epoxy compound, polyisocyanate) to the pigment surface. It is done. The above-mentioned surface treatment methods are described in “Characteristics and Applications of Metal Soap” (Yokoshobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.
[0135]
The particle size of the pigment is preferably in the range of 0.01 to 10 μm from the viewpoint of stability of the dispersion in the coating solution for the heat sensitive layer and the uniformity of the heat sensitive layer, and 0.05 to 1 μm. Is more preferably in the range of 0.1 to 1 μm.
[0136]
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).
[0137]
As the dye, commercially available dyes and known dyes described in literature (for example, “Dye Handbook” edited by the Society of Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, and cyanine dyes can be used.
[0138]
In the present invention, among these pigments or dyes, those that absorb infrared light or near infrared light are particularly preferred because they are suitable for use with lasers that emit infrared light or near infrared light.
[0139]
Carbon black is suitably used as the pigment that absorbs such infrared light or near infrared light. Examples of the dye that absorbs infrared light or near infrared light include, for example, JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, and JP-A-60. Cyanine dyes described in JP-A-78787 etc., methine dyes described in JP-A-58-173696, JP-A-58-181690, JP-A-58-194595, etc. JP 58-112793, JP 58-224793, JP 59-48187, JP 59-73996, JP 60-52940, JP 60-63744. Naphthoquinone dyes described in Japanese Laid-Open Patent Publications, etc., squarylium dyes described in Japanese Patent Laid-Open No. 58-112792, etc., and shear dyes described in British Patent No. 434,875. Emissions dye include dihydroperimidine squarylium dyes described in U.S. Patent No. 5,380,635.
[0140]
Further, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used as the dye, and a substituted dye described in US Pat. No. 3,881,924 is also used. Arylbenzo (thio) pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, JP-A-58-181051 JP 58-221433, JP 59-41363, JP 59-84248, JP 59-84249, JP 59-146063, JP 59-146061 Pyrylium compounds described in Japanese Laid-Open Patent Publications, cyanine dyes described in Japanese Patent Application Laid-Open No. 59-216146, pentamethine thiopic compounds described in US Pat. No. 4,283,475 Particularly preferred are the pyrium compounds described in JP-B-5-13514, JP-B-5-19702, Epolight III-178, Epolight III-130, Epolight III-125, Epolight IV-62A, and the like. Used.
[0141]
Another particularly preferable example of the dye is a near-infrared absorbing dye described as formula (I) or (II) in US Pat. No. 4,756,993.
[0142]
These pigments or dyes are preferably 0.01 to 50% by weight, more preferably 0.1 to 10% by weight, and particularly preferably 0.5 to 10% by weight, based on the total solid content of the heat-sensitive layer. In the case of mass% and a pigment, it can be added to the photosensitive composition particularly preferably at a ratio of 3.1 to 10 mass%. When the added amount of the pigment or dye is less than 0.01% by mass, the sensitivity is lowered, and when it exceeds 50% by mass, the uniformity of the heat sensitive layer is lost and the durability of the heat sensitive layer is deteriorated.
These dyes or pigments may be added to the same layer as other components, or a separate layer may be provided and added thereto. In the case of another layer, it is preferably added to a layer adjacent to a layer containing a substance that substantially reduces the solubility of the alkali-soluble resin in the state of being thermally decomposable and not decomposing.
Further, the dye or pigment and the alkali-soluble resin are preferably contained in the same layer, but may be in different layers.
[0143]
(B + C) component
In the present invention, (B) a compound that decreases the solubility of the resin in an aqueous alkaline solution by being compatible with the alkali-soluble resin, and (C) absorbs infrared rays. Instead of the photothermal conversion agent that generates heat, it is also possible to contain one compound having both characteristics (hereinafter also referred to as “(B + C) component”). Examples of such a compound include those represented by the following general formula (Z).
[0144]
Embedded image
[0145]
In the general formula (Z), R ₁ ~ R _Four Each independently represents a hydrogen atom or a C1-C12 alkyl group, alkenyl group, alkoxy group, cycloalkyl group or aryl group which may have a substituent, R ₁ And R ₂ , R _Three And R _Four May be bonded to each other to form a ring structure. Where R ₁ ~ R _Four Specific examples thereof include a hydrogen atom, a methyl group, an ethyl group, a phenyl group, a dodecyl group, a naphthyl group, a vinyl group, an allyl group, and a cyclohexyl group. When these groups have a substituent, examples of the substituent include a halogen atom, a carbonyl group, a nitro group, a nitrile group, a sulfonyl group, a carboxy group, a carboxylic acid ester, and a sulfonic acid ester.
R _Five ~ R _Ten Each independently represents a C 1-12 alkyl group which may have a substituent, wherein R _Five ~ R _Ten Specific examples thereof include a methyl group, an ethyl group, a phenyl group, a dodecyl group, a naphthyl group, a vinyl group, an allyl group, and a cyclohexyl group. When these groups have a substituent, examples of the substituent include a halogen atom, a carbonyl group, a nitro group, a nitrile group, a sulfonyl group, a carboxy group, a carboxylic acid ester, and a sulfonic acid ester.
[0146]
R ₁₁ ~ R ₁₃ Each independently represents a hydrogen atom, a halogen atom or an optionally substituted alkyl group having 1 to 8 carbon atoms, wherein R ₁₂ Is R ₁₁ Or R ₁₃ To form a ring structure, and when m> 2, a plurality of R ₁₂ They may be bonded to each other to form a ring structure. R ₁₁ ~ R ₁₃ Specifically, a chlorine atom, a cyclohexyl group, R ₁₂ Examples thereof include a cyclopentyl ring and a cyclohexyl ring formed by bonding each other. When these groups have a substituent, examples of the substituent include a halogen atom, a carbonyl group, a nitro group, a nitrile group, a sulfonyl group, a carboxy group, a carboxylic acid ester, and a sulfonic acid ester. Moreover, m represents the integer of 1-8, Preferably it is 1-3.
R ₁₄ And R ₁₅ Each independently represents a hydrogen atom, a halogen atom or an optionally substituted alkyl group having 1 to 8 carbon atoms, R ₁₄ Is R ₁₅ To form a ring structure, and when m> 2, a plurality of R ₁₄ They may be bonded to each other to form a ring structure. R ₁₄ And R ₁₅ Specifically, a chlorine atom, a cyclohexyl group, R ₁₄ Examples thereof include a cyclopentyl ring and a cyclohexyl ring formed by bonding each other. When these groups have a substituent, examples of the substituent include a halogen atom, a carbonyl group, a nitro group, a nitrile group, a sulfonyl group, a carboxy group, a carboxylic acid ester, and a sulfonic acid ester. Moreover, m represents the integer of 1-8, Preferably it is 1-3.
[0147]
In the general formula (Z), X ^- Represents an anion. Specific examples of the anion compound include perchloric acid, tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5 -Dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1 -Naphthol-5-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, paratoluenesulfonic acid. Of these, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, and alkyl aromatic sulfonic acids such as 2,5-dimethylbenzenesulfonic acid are particularly preferably used.
[0148]
The compound represented by the general formula (Z) is a compound generally referred to as a cyanine dye. Specifically, the following compounds are preferably used, but the present invention is not limited to these specific examples. Absent.
[0149]
Embedded image
[0150]
The component (B + C) has the property of generating heat by absorbing infrared rays (that is, the properties of the component (C)), and has an absorption region in the infrared region of 700 to 1200 nm, and further compatible with alkali-soluble resins. And is a basic dye, and has a group that interacts with an alkali-soluble resin such as an ammonium group or an iminium group in the molecule (that is, has the characteristics of the component (B)). By acting, the alkali solubility can be controlled and can be suitably used in the present invention.
[0151]
In the present invention, when a compound (B + C) component having both characteristics such as the above-mentioned cyanine dye is used in place of the component (B) and the component (C), the amount of this compound added to the component (A) On the other hand, the range of 99/1 to 70/30 is preferable from the viewpoint of sensitivity, and the range of 99/1 to 75/25 is more preferable.
[0152]
(D) Other ingredients
In addition to the above essential components, the heat-sensitive layer can contain various additives as necessary within a range not impairing the object of the present invention. Hereinafter, examples of additives will be described.
For example, it is preferable to use a substance that is thermally decomposable and substantially reduces the solubility of the alkaline water-soluble resin in a state where it is not decomposed, since it can improve the dissolution inhibition property of the image area in the developer. . Examples of such substances include onium salts, quinonediazides, aromatic sulfone compounds, and aromatic sulfonic acid ester compounds.
Examples of onium salts include diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, and arsonium salts.
[0153]
Among them, preferable examples include S.I. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Diazonium salts described in Balet al, Polymer, 21, 423 (1980) and JP-A-5-158230, US Pat. Nos. 4,069,055, 4,069,056 and An ammonium salt described in Kaihei 3-140140; C. Necker et al, Macromolecules, 17, 2468 (1984), C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p. 478, Tokyo, Oct (1988), U.S. Pat. Nos. 4,069,055 and 4,069,056, phosphonium salts described in J. Am. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), Chem. & Amp, Eng. News, Nov. 28, p31 (1988), EP 104,143, U.S. Pat. No. 339,049, 410,201, JP-A-2-150848 and JP-A-2-296514. Iodonium salts described in the publication, J. Org. V. Crivello et al, Polymer J. et al. 17, 73 (1985), J. Am. V. Crivello et al. J. et al. Org. Chem. 43, 3055 (1978); R. Watt et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 22, 1789 (1984), J. Am. V. Crivello et al, Polymer Bull. 14, 279 (1985), J. Am. V. Crivello et al, Macromolecules, 14 (5), 1141 (1981), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. 17, 2877 (1979), European Patent Nos. 370,693, 233,567, 297,443, 297,442, U.S. Pat. No. 4,933,377. No. 3,902,114, No. 410,201, No. 339,049, No. 4,760,013, No. 4,734,444, No. 2,833,827, German Patent Nos. 2,904,626, 3,604,580 and 3,604,581; J. et al. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977) and J. Am. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. 17, 1047 (1979), selenonium salts, C.I. S. Wen et al, Teh, Proc. Conf. Rad. Examples include the arsonium salts described in Curing ASIA, p478, Tokyo, Oct (1988).
Of the onium salts, diazonium salts are particularly preferred. Particularly preferred diazonium salts include those described in JP-A-5-158230.
[0154]
Examples of counter ions of onium salts include tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 5-sulfosalicylic acid, and 2,5-dimethylbenzenesulfone. Acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5 -Sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, paratoluenesulfonic acid. Among these, hexafluorophosphoric acid; alkyl aromatic sulfonic acids such as triisopropylnaphthalenesulfonic acid and 2,5-dimethylbenzenesulfonic acid are preferable.
[0155]
As the quinonediazides, o-quinonediazide compounds are preferable.
The o-quinonediazide compound used in the present invention is a compound having at least one o-quinonediazide group and increasing alkali solubility by thermal decomposition, and compounds having various structures can be used. The o-quinonediazide compound reduces the solubility of the binder by thermal decomposition, and the effect of changing the o-quinonediazide compound itself into an alkali-soluble substance. Improve.
Examples of the o-quinonediazide compound used in the present invention include J. "Light-sensitive systems" by John Coley (John Wiley &amp; Sons. Inc.) p. Although the compounds described in 339 to 352 can be used, sulfonic acid esters or sulfonic acid amides of o-quinonediazide compounds reacted with various aromatic polyhydroxy compounds or aromatic amino compounds are particularly preferable. Further, benzoquinone (1,2) -diazide sulfonic acid chloride or naphthoquinone- (1,2) -diazide-5-sulfonic acid chloride and pyrogallol-acetone resin as described in JP-B-43-28403 Esters of benzoquinone- (1,2) -diazide sulfonic acid chloride or naphthoquinone- (1,2) described in U.S. Pat. Nos. 3,046,120 and 3,188,210. ) -Diazide-5-sulfonic acid chloride and phenol-formaldehyde resin are also preferably used.
[0156]
Further, esters of naphthoquinone- (1,2) -diazido-4-sulfonic acid chloride with phenol formaldehyde resin or cresol-formaldehyde resin, naphthoquinone- (1,2) -diazido-4-sulfonic acid chloride and pyrogallol-acetone resin Similarly, an ester is also preferably used. In addition, useful o-quinonediazide compounds are reported and known in numerous patents. For example, JP-A-47-5303, JP-A-48-63802, JP-A-48-63803, JP-A-48-96575, JP-A-49-38701, JP-A-49-38701 No. 48-13354, Japanese Examined Patent Publication No. 41-11222, Japanese Examined Patent Publication No. 45-9610, Japanese Examined Patent Publication No. 49-17478, US Pat. No. 2,797,213, No. 3,454,400. No. 3,544,323, No. 3,573,917, No. 3,674,495, No. 3,785,825, British Patent No. No. 1,227,602, No. 1,251,345, No. 1,267,005, No. 1,329,888, No. 1,330,932 Description and German Patent No. 854,890 They include those described in the specification.
[0157]
The addition amount of each of the onium salt and the o-quinonediazide compound is preferably 1 to 50% by mass, more preferably 5 to 30% by mass, and particularly preferably 10 to 30% by mass with respect to the total solid content of the layer to be added. %. These compounds may be used alone or in a mixture of two or more.
[0158]
The addition amount of additives other than the onium salt and the o-quinonediazide compound is preferably 1 to 50% by mass, more preferably 5 to 30% by mass, and particularly preferably 10 to 10% by mass with respect to the total solid content of the layer to be added. 30% by mass. In the present invention, the additive and the alkali-soluble resin are preferably contained in the same layer.
[0159]
The heat-sensitive layer is a perfluorocarbon having 3 to 20 carbon atoms in the molecule as described in JP-A-2000-187318 for the purpose of enhancing the resistance to image discrimination and surface scratches. A polymer containing a (meth) acrylate monomer having 2 or 3 alkyl groups as a polymerization component is preferably contained.
The addition amount of such a polymer is preferably 0.1 to 10% by mass, and more preferably 0.5 to 5% by mass with respect to the total solid content of the layer to be added.
[0160]
The heat-sensitive layer can also contain a compound that reduces the surface static friction coefficient for the purpose of imparting resistance to scratches. Such compounds include, for example, esters of long chain alkyl carboxylic acids as described in US Pat. No. 6,117,913.
The amount of such a compound added is preferably 0.1 to 10% by mass, and more preferably 0.5 to 5% by mass, based on the total solid content of the layer to be added.
[0161]
Moreover, the heat sensitive layer may contain the compound which has a low molecular weight acidic group as needed. Examples of the acidic group include a sulfonic acid group, a carboxy group, and a phosphoric acid group. Among these, a compound having a sulfonic acid group is preferable. Specific examples include aromatic sulfonic acids such as p-toluenesulfonic acid and naphthalenesulfonic acid, and aliphatic sulfonic acids.
The addition amount of such a compound is preferably 0.05 to 5% by mass and more preferably 0.1 to 3% by mass with respect to the total solid content of the layer to be added. If it exceeds 5% by mass, the solubility of each layer in the developer may increase, which is not preferable.
[0162]
Moreover, the heat-sensitive layer may contain various dissolution inhibitors for the purpose of adjusting the solubility of each layer. As the dissolution inhibitor, a disulfone compound or a sulfone compound as described in JP-A-11-119418 is preferably used. Specifically, 4,4′-bishydroxyphenyl sulfone is preferably exemplified.
The addition amount of the dissolution inhibitor is preferably 0.05 to 20% by mass, and more preferably 0.5 to 10% by mass, based on the total solid content of the layer to be added.
[0163]
The heat-sensitive layer can also contain cyclic acid anhydrides, phenols, organic acids, and sulfonyl compounds for the purpose of further improving sensitivity.
Examples of cyclic acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and 3,6-endooxy-Δ4-tetrahydro described in US Pat. No. 4,115,128. Examples thereof include phthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, and pyromellitic anhydride.
Examples of phenols include bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,4,4'-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ' , 4 "-trihydroxytriphenylmethane, 4,4 ', 3", 4 "-tetrahydroxy-3,5,3', 5'-tetramethyltriphenylmethane.
[0164]
Examples of organic acids include sulfonic acids, sulfinic acids, alkyl sulfates, phosphonic acids, phosphate esters, and carboxylic acids described in, for example, JP-A-60-88942 and JP-A-2-96755. Is mentioned. Specifically, for example, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethyl sulfate, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipine Examples include acid, p-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 4-cyclohexene-1,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, and ascorbic acid.
Examples of the sulfonyl compound include bishydroxyphenylsulfone, methylphenylsulfone, and diphenyldisulfone.
The amount of the cyclic acid anhydrides, phenols, organic acids and sulfonyl compounds added is preferably 0.05 to 20% by mass with respect to the total solid content of the layer to be added. More preferably, it is -15 mass%, and it is especially preferable that it is 0.1-10 mass%.
[0165]
In addition, the heat-sensitive layer is a nonionic surfactant as described in JP-A-62-251740 and JP-A-3-208514, in order to broaden the processing stability against changes in development conditions. Amphoteric surfactants such as those described in JP-A-59-121044 and JP-A-4-13149, siloxane compounds as described in European Patent Application Publication No. 950,517, A fluorine-containing monomer copolymer as described in JP-A-11-288093 can be contained.
Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, and polyoxyethylene nonylphenyl ether.
Specific examples of amphoteric surfactants include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, N-tetradecyl-N, N- Betaine type (for example, trade name “Amorgen K”, manufactured by Daiichi Kogyo Co., Ltd.) may be mentioned.
As the siloxane compound, a block copolymer of dimethylsiloxane and polyalkylene oxide is preferable. Specific examples include DBE-224, DBE-621, DBE-712, DBP-732, DBP-534, German Tego manufactured by Chisso Corporation. Examples include polyalkylene oxide-modified silicones such as Tego Glide 100 manufactured by the company.
The addition amount of the nonionic surfactant, amphoteric surfactant and siloxane compound is preferably 0.05 to 15% by mass with respect to the total solid content of the layer to be added. More preferably, it is -5 mass%.
[0166]
The heat-sensitive layer can contain a print-out agent for obtaining a visible image immediately after heating by exposure, and a dye or pigment as an image colorant.
Examples of the printing-out agent include a combination of a compound that releases an acid by heating by exposure (photoacid releasing agent) and an organic dye that can form a salt. Specifically, a combination of o-naphthoquinonediazide-4-sulfonic acid halide and a salt-forming organic dye described in JP-A-50-36209 and JP-A-53-8128, JP 53-36223, JP 54-74728, JP 60-3626, JP 61-143748, JP 61-151644, and 63-58440 The combination of the trihalomethyl compound and salt forming organic dye which are described in the gazette is mentioned. Such trihalomethyl compounds include oxazole compounds and triazine compounds, both of which have excellent temporal stability and give clear printout images.
[0167]
As the image colorant, other dyes can be used in addition to the aforementioned salt-forming organic dyes. Examples of suitable dyes including salt-forming organic dyes include oil-soluble dyes and basic dyes. Specifically, for example, oil yellow # 101, oil yellow # 103, oil pink # 312, oil green BG, oil blue BOS, oil blue # 603, oil black BY, oil black BS, oil black T-505 (or more Orient Pure Chemical Industries), Victoria Pure Blue, Crystal Violet (C.I. 42555), Methyl Violet (C.I. 42535), Ethyl Violet, Rhodamine B (C.I. 145170B), Malachite Green (C.I. 42000) and methylene blue (C.I. 52015). The dyes described in JP-A-62-293247 and JP-A-5-313359 are particularly preferred.
The addition amount of these dyes is preferably 0.01 to 10% by mass, more preferably 0.1 to 3% by mass, based on the total solid content of the layer to be added.
Moreover, in order to provide the softness | flexibility etc. of a coating film, a heat sensitive layer can contain a plasticizer as needed. For example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid The following oligomers and polymers are used.
Furthermore, the heat-sensitive layer can contain a compound that decomposes by light, such as quinonediazides and diazo compounds, if necessary. It is preferable that the addition amount of these compounds is 1-5 mass% with respect to the total solid of the layer added.
[0168]
The heat-sensitive layer can be produced by usually dissolving the above components in a solvent and applying the solution on the lithographic printing plate support. Examples of the solvent used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate. , Dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, and toluene. It is not limited to these. These solvents are used alone or in combination.
The concentration of the above components (total solid content including additives) in the solvent is preferably 1 to 50% by mass.
[0169]
Moreover, the heat sensitive layer coating amount (solid content) on the support obtained after coating and drying is 0.5 to 5.0 g / m. ² Is preferred.
[0170]
Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.
The heat-sensitive layer can contain a surfactant for improving the coating property, for example, a fluorosurfactant as described in JP-A-62-170950. The addition amount of the surfactant for improving the coatability is preferably 0.01 to 1% by mass, and 0.05 to 0.5% by mass with respect to the total solid content of the layer to be added. More preferably.
[0171]
<Thermosensitive layer 2>
The heat-sensitive layer 2 used in the lithographic printing plate precursor according to the invention is a multilayer heat-sensitive layer composed of two layers that are alkali-solubilized by heating. Specifically, a multilayer heat-sensitive layer having two layers of a heat-sensitive layer provided at a position close to the surface (exposed surface) of the lithographic printing plate precursor and a lower layer provided on the side close to the support can be mentioned. . When such a multilayer heat-sensitive layer is provided, the alkali-soluble layer and the surface hardly-solubilized layer can be provided separately, so that a larger discrimination is obtained, that is, the developability is excellent. In addition, scratch resistance (hardness to scratches) is excellent. This is because, by providing a lower layer on an aluminum support, the uneven shape of the support is absorbed to form a relatively flat surface, and a further heat-sensitive layer is further laminated on the surface to provide a flatter heat-sensitive layer. This is because the surface is formed.
The lower layer and the heat-sensitive layer both contain a water-insoluble and alkali-soluble resin, and the heat-sensitive layer located at the upper part of the lower layer further contains a photothermal conversion agent that generates heat by absorbing infrared rays.
[0172]
In the present invention, examples of the alkali-soluble resin used for the lower layer and the heat-sensitive layer include the same resins as those used for the heat-sensitive layer 1. Since the lower layer and the heat-sensitive layer used in the present invention contain an alkali-soluble resin, they have a property of dissolving when in contact with an alkaline developer.
[0173]
As the alkali-soluble resin used for the lower layer, an acrylic resin is preferable. When the lower layer contains an acrylic resin as an alkali-soluble resin, the solubility of the lower layer can be well maintained in an alkaline developer mainly composed of an organic compound having a buffering action and a base. Will be excellent. Among them, an acrylic resin having a sulfonamide group is particularly preferable.
Moreover, as alkali-soluble resin used for a lower layer, resin which has a phenolic hydroxyl group is preferable. When the lower layer contains a resin having a phenolic hydroxyl group as an alkali-soluble resin, strong hydrogen bonding occurs in the unexposed area, while some hydrogen bonds are easily released in the exposed area. Since the difference in developability between the unexposed area and the exposed area is large with respect to the liquid, the image formability during development is excellent. Among these, novolac resin is particularly preferable.
[0174]
As the alkali-soluble resin used in the heat-sensitive layer, a resin having a phenolic hydroxyl group is preferable. When the heat-sensitive layer contains a resin having a phenolic hydroxyl group as an alkali-soluble resin, strong hydrogen bonding is caused in the unexposed area, while some hydrogen bonds are easily released in the exposed area. Since the difference in developability between the unexposed area and the exposed area is large with respect to the developer, the image formability during development is excellent. Among these, novolac resin is particularly preferable.
[0175]
These alkali-soluble resins may be used alone or in combination of two or more.
The alkali-soluble resin is preferably used in an addition amount of 30 to 99% by mass, more preferably 40 to 95% by mass, and particularly preferably 50 to 90% by mass with respect to the total solid content of the heat-sensitive layer. When the addition amount of the alkali-soluble resin is less than 30% by mass, the durability of the heat-sensitive layer is deteriorated, and when it exceeds 99% by mass, it is not preferable in terms of both sensitivity and durability.
The alkali-soluble resin is preferably used in an amount of 50 to 99% by mass, more preferably 60 to 95% by mass, and particularly preferably 70 to 95% by mass with respect to the total solid content of the lower layer. When the addition amount of the alkali-soluble resin is less than 50% by mass, the durability of the lower layer is deteriorated, and when it exceeds 99% by mass, it is not preferable in terms of both sensitivity and durability.
[0176]
In the present invention, examples of the light-to-heat conversion agent that generates heat by absorbing infrared rays used in the heat-sensitive layer include those similar to those used in the heat-sensitive layer 1.
[0177]
These photothermal conversion agents can be added not only to the heat-sensitive layer but also to the lower layer. By adding a photothermal conversion agent to the lower layer, the lower layer can also function as a heat-sensitive layer. When a photothermal conversion agent is added to the lower layer, the same material as in the upper heat-sensitive layer may be used, or a different material may be used.
Moreover, these photothermal conversion agents may be added to the same layer as other components, or another layer may be provided and added thereto. When it is set as another layer, it is desirable to add to the layer adjacent to the heat-sensitive layer. The dye and the alkali-soluble resin are preferably contained in the same layer, but may be in different layers.
As the addition amount, 0.01 to 50% by mass, preferably 0.1 to 10% by mass, particularly preferably 0.5 to 10% by mass, is added to the printing plate material with respect to the total solid content of the printing plate material. can do. When the added amount of the dye is 0.01 to 50% by mass, the sensitivity becomes high, the uniformity of the heat sensitive layer is high, and the durability of the heat sensitive layer is excellent.
[0178]
In addition to the above essential components, the lower layer and the heat-sensitive layer can contain various additives as necessary within a range not impairing the object of the present invention. The additive may be contained only in the lower layer, may be contained only in the heat-sensitive layer, or may be contained in both layers.
Specific examples of the additive and the amount of the additive are basically the same as those of the heat-sensitive layer 1, but the following points are further mentioned.
[0179]
The lower layer and the heat-sensitive layer preferably contain a polymer having a polymerization component of a (meth) acrylate monomer having 2 or 3 perfluoroalkyl groups having 3 to 20 carbon atoms in the molecule, and the surface static friction coefficient. The compound to be reduced may be contained in either the lower layer or the heat-sensitive layer, but it is more effective if it is contained in the heat-sensitive layer located in the upper part.
[0180]
After applying the lower layer, adjacent to it, when applying the upper heat-sensitive layer, if a solvent capable of dissolving the lower layer alkali-soluble resin is used as the upper layer coating solvent, mixing at the layer interface cannot be ignored, In extreme cases, it may become a uniform single layer rather than a multilayer. As described above, when mixing occurs at the interface between two adjacent layers or they are mixed with each other and behave like a uniform layer, the effect of the lithographic printing plate precursor according to the present invention by having two layers is effective. There is a risk of damage, which is not preferable. For this reason, it is preferable that the solvent used for apply | coating a thermosensitive layer is a poor solvent with respect to the alkali-soluble resin contained in a lower layer.
The concentration of the above components (total solid content including additives) in the solvent when applying each layer is preferably 1 to 50% by mass.
Moreover, although the coating amount (solid content) of the lower layer and heat-sensitive layer on the support obtained after coating and drying varies depending on the application, the heat-sensitive layer is 0.05 to 1.0 g / m. ² It is preferable that the lower layer is 0.3 to 3.0 g / m. ² Is preferred. The coating amount of the heat sensitive layer is 0.05 to 1.0 g / m. ² If it is, the image forming property is high and the sensitivity is also improved. Moreover, the coating amount of the lower layer is 0.3 to 3.0 g / m ² If it is, the image formability is improved.
Moreover, the coating amount of the lower layer and the heat sensitive layer is 0.5 to 3.0 g / m in total of the two layers. ² Is preferred. The total coating amount of the two layers is 0.5 to 3.0 g / m ² When it is, the film characteristics are improved and the sensitivity is increased. As the coating amount decreases, the apparent sensitivity increases, but the film properties of the photosensitive film deteriorate.
[0181]
<Overcoat layer>
In the lithographic printing plate precursor according to the invention, a water-soluble overcoat layer can be provided on the image recording layer in order to prevent contamination of the heat-sensitive layer surface with an oleophilic substance. The water-soluble overcoat layer used in the present invention is preferably one that can be easily removed during printing, and contains a resin selected from water-soluble organic polymer compounds.
As the water-soluble organic polymer compound, a film formed by coating and drying has film-forming ability. Specifically, for example, polyvinyl acetate (however, a hydrolysis rate of 65% or more), polyacrylic Acid and its alkali metal salt or amine salt, polyacrylic acid copolymer and its alkali metal salt or amine salt, polymethacrylic acid and its alkali metal salt or amine salt, polymethacrylic acid copolymer and its alkali metal salt or amine Salt, polyacrylamide and copolymer thereof, polyhydroxyethyl acrylate, polyvinylpyrrolidone and copolymer thereof, polyvinyl methyl ether, polyvinyl methyl ether / maleic anhydride copolymer, poly-2-acrylamide-2-methyl-1- Propanesulfonic acid and its al Li metal salt or amine salt, poly-2-acrylamido-2-methyl-1-propanesulfonic acid copolymer and its alkali metal salt or amine salt, gum arabic, fiber derivative (for example, carboxymethyl cellulose, carboxyethyl cellulose) , Methyl cellulose, etc.) and modified products thereof, white dextrin, pullulan, enzymatically-decomposed etherified dextrin, and the like. Further, two or more kinds of these resins can be mixed and used depending on the purpose.
[0182]
Moreover, you may add a water-soluble thing among the above-mentioned photothermal conversion agents to an overcoat layer. Furthermore, for the purpose of ensuring the uniformity of coating, a nonionic surfactant such as polyoxyethylene nonylphenyl ether or polyoxyethylene dodecyl ether can be added to the overcoat layer in the case of aqueous solution coating. . The dry coating amount of the overcoat layer is 0.1 to 2.0 g / m. ² Is preferred. Within this range, the on-press developability is not impaired, and the surface of the heat-sensitive layer can be satisfactorily prevented from being contaminated with lipophilic substances such as fingerprints.
[0183]
<Back coat>
In this way, if necessary, the back surface of the lithographic printing plate precursor of the present invention obtained by providing the image recording layer on the lithographic printing plate support of the present invention is scratched on the image recording layer when it is overlaid. In order to prevent sticking, a coating layer made of an organic polymer compound can be provided.
[0184]
<Method for producing planographic printing plate precursor>
Each layer such as an image recording layer can be usually produced by applying a coating solution obtained by dissolving the above components in a solvent onto the lithographic printing plate support.
Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, the present invention is not limited to these. These solvents are used alone or in combination.
The concentration of the above components (total solid content) in the solvent is preferably 1 to 50% by mass.
[0185]
Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.
[0186]
[Plate making method (lithographic printing plate production method)]
The lithographic printing plate precursor according to the invention is made into a lithographic printing plate by various processing methods according to the image recording layer.
Examples of the actinic ray light source used for image exposure include a mercury lamp, a metal halide lamp, a xenon lamp, and a chemical lamp. Examples of the laser beam include a helium-neon laser (He-Ne laser), an argon laser, a krypton laser, a helium-cadmium laser, a KrF excimer laser, a semiconductor laser, a YAG laser, and a YAG-SHG laser.
[0187]
After the exposure, it is preferable to obtain a lithographic printing plate by developing using a developer after the exposure.
The developer is preferably an alkaline developer, and more preferably an alkaline aqueous solution that does not substantially contain an organic solvent.
A developer substantially free of alkali metal silicate is also preferred. As a method of developing using this developer, a method described in detail in JP-A-11-109637 can be used.
A developer containing an alkali metal silicate can also be used.
[0188]
When using a processing method for a lithographic printing plate precursor that is developed using a developer that does not substantially contain an alkali metal silicate, it is excellent in stain resistance and developed using a developer containing an alkali metal silicate. Compared with the case of SiO ₂ It is difficult for the solid matter resulting from the precipitation, and the neutralization treatment when treating the waste solution of the developer is easy.
[0189]
In the lithographic printing plate precursor according to the invention, an intermediate layer containing a compound having a functional group capable of interacting with the resin in the image recording layer is provided on a lithographic printing plate support subjected to a hydrophilic treatment, and a water layer is further provided thereon. Since it is a lithographic printing plate precursor provided with an image recording layer containing an insoluble and alkali-soluble resin, the adhesion between the intermediate layer and the image recording layer becomes strong, and the excellent stain resistance due to the hydrophilic layer and the resin The printing durability can be improved without impairing the print quality.
[0190]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
[0191]
Example 1 , 2, 6, 7, Reference Examples 3-5 8]
1. Production of lithographic printing plate support
<Support for lithographic printing plate 1>
Using a JIS A1050 aluminum plate having a plate thickness of 0.3 mm, the following surface treatments were sequentially performed to obtain a lithographic printing plate support 1.
[0192]
(A) Mechanical roughening treatment
Using a commonly used apparatus, a suspension of abrasive (silica sand) and water (specific gravity 1.1 g / cm) ^Three ) Was supplied to the surface of the aluminum plate as a polishing slurry liquid, and a mechanical surface roughening treatment was performed with a rotating roller nylon brush.
The average particle size of the abrasive was 8 μm, and the maximum particle size was 50 μm. The material of the nylon brush was 6 · 10 nylon, the hair length was 50 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 7 kW plus with respect to the load before the brush roller was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The rotation speed of the brush was 200 rpm.
[0193]
(B) Alkali etching treatment
The aluminum plate obtained above was subjected to etching treatment by spraying at a caustic soda concentration of 26 mass%, an aluminum ion concentration of 6.5 mass%, and a temperature of 70 ° C., and the aluminum plate was 6 g / m 2. ² Dissolved. Then, water washing by spraying was performed.
[0194]
(C) Desmut treatment
A desmut treatment was performed by spraying with a 1% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 0.5% by weight of aluminum ions), and then washed with water by spraying. The aqueous nitric acid solution used for the desmutting treatment was a waste liquid from an electrochemical surface roughening treatment using alternating current in an aqueous nitric acid solution.
[0195]
(D) Electrochemical roughening treatment
An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a nitric acid 10.5 g / L aqueous solution (containing 5 g / L of aluminum ions) at a temperature of 50 ° C. The AC power source waveform was subjected to an electrochemical surface roughening process using a trapezoidal wave alternating current with a time TP of 0.8 msec until the current value reached a peak and a duty ratio of 1: 1 using a carbon electrode as a counter electrode. . Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type.
The current density is 30 A / dm at the peak current value. ² The amount of electricity is 220 C / dm in terms of the total amount of electricity when the aluminum plate is the anode. ² Met. 5% of the current flowing from the power source was shunted to the auxiliary anode.
Then, water washing by spraying was performed.
[0196]
(E) Alkali etching treatment
The aluminum plate was etched at 32 ° C. with a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass%, and the aluminum plate was 3.5 g / m. ² Dissolve and remove the smut component mainly composed of aluminum hydroxide that was generated when electrochemical roughening treatment was performed using alternating current in the previous stage, and dissolve the edge part of the generated pit to produce the edge part Made smooth. Then, water washing by spraying was performed.
[0197]
(F) Desmut treatment
The desmutting treatment was performed by spraying with a 15% by weight aqueous solution of sulfuric acid at a temperature of 30 ° C. (containing 4.5% by weight of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut was the waste liquid from the step of electrochemical surface roughening treatment using alternating current in nitric acid aqueous solution.
[0198]
(G) Electrochemical roughening treatment
An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 7.5 g / L aqueous solution (containing 5 g / L of aluminum ions) at a temperature of 35 ° C. The AC power supply waveform was a rectangular wave, and an electrochemical roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type.
The current density is 25 A / dm at the peak current value. ² The amount of electricity is 50 C / dm as the total amount of electricity when the aluminum plate is the anode. ² Met.
Then, water washing by spraying was performed.
[0199]
(H) Alkali etching treatment
The aluminum plate was etched at 32 ° C. with a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass%, and the aluminum plate was 0.10 g / m. ² Dissolves and removes the smut component mainly composed of aluminum hydroxide that was generated when the electrochemical roughening treatment was performed using the alternating current of the previous stage, and the edge part of the generated pits was dissolved to the edge The part was smoothed. Then, water washing by spraying was performed.
[0200]
(I) Desmut treatment
The desmutting treatment was performed by spraying with a 25% by weight aqueous solution of sulfuric acid having a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), and then washing with water by spraying.
[0201]
(J) Anodizing treatment
An apparatus generally used for anodizing treatment was used. A sulfuric acid solution was used as the electrolytic solution. The electrolytic solution had a sulfuric acid concentration of 170 g / L (containing 0.5% by mass of aluminum ions) and a temperature of 43 ° C. Then, water washing by spraying was performed.
Current density is about 30A / dm ² Met. The final oxide film amount is 2.7 g / m ² Met.
[0202]
(K) Hydrophilization treatment (alkali metal silicate treatment)
Alkali metal silicate treatment (silicate treatment) is performed by immersing the aluminum support obtained by anodizing treatment in a treatment layer of 1 mass% aqueous solution of sodium silicate No. 3 at a temperature of 30 ° C. for 10 seconds. It was. Then, the water washing by the spray using well water was performed. The amount of silicate adhering at that time is 3.5 mg / m ² Met.
[0203]
<Support 2 for planographic printing plate>
The steps (g), (h) and (i) are not performed, and in the step (e), the dissolution amount (etching amount) of the aluminum plate is 0.20 g / m. ² Except for the above, a lithographic printing plate support 2 was obtained in the same manner as in <lithographic printing plate support 1>.
[0204]
2. Synthesis of polymers used for intermediate layers
Example And reference examples The number given to the polymer used in is the same as the number given to the polymer exemplified above.
[0205]
<Polymer (P-8)>
Blenmer PME-400 (Nippon Yushi Co., Ltd.) 33.4 g (30.0 mmol), p-vinylbenzoic acid (Hokukogaku ( Ltd.) 2.96 g (20.0 mmol) g and 2,2′-azobis (dimethyl isobutyrate) (V601, Wako Pure Chemical Industries, Ltd.) 0.576 g (2.5 mmol) in a solution of 67.8 g of methanol Was added dropwise over 2 hours, and after the addition, the reaction was further continued for 9 hours.
Ethyl acetate is added to the reaction solution to precipitate the reaction product. The precipitate is collected by filtration and dried to give 28.6 g of polymer (P-8) (acid value 0.56 meq / g, weight average molecular weight 7.5 × 10 ^Four )
[0206]
<Polymer (P-12)>
In a 200 mL three-necked flask to which 7.35 g of dimethylacetamide (DMAc) was added, N-phenylmethacrylamide 11.3 g (70.0 mmol), p-vinylbenzoic acid (Hokukogaku Co., Ltd.) under a nitrogen atmosphere at 75 ° C. ) A mixed solution of 4.44 g (30.0 mmol), V601 1.15 g (5.0 mmol), and DMAc 29.4 g was added dropwise over 2 hours, and after the addition, the reaction was continued for another 5 hours.
Ethyl acetate is added to the reaction solution to precipitate the reaction product. The precipitate is collected by filtration and dried to give 11.8 g of polymer (P-12) (acid value 1.91 meq / g, weight average molecular weight 3.5 × 10 ^Four )
[0207]
<Polymer (P-14)>
N, N-dimethylacrylamide 7.93 g (80.0 mmol), light ester HOMS (Kyoeisha Chemical Co., Ltd.) under a nitrogen atmosphere at 75 ° C. in a 200 mL three-necked flask to which 6.0 g of dimethylacetamide (DMAc) was added A mixed solution of 4.9 g (20.0 mmol), V601 1.15 g (5.0 mmol), and DMAc 24.0 g was added dropwise over 2 hours, and after the addition, the reaction was further continued for 5 hours.
Ethyl acetate is added to the reaction solution to precipitate the reaction product. The precipitate is collected by filtration and dried to give 11.9 g of polymer (P-14) (acid value 1.52 meq / g, weight average molecular weight 6.5 × 10 ^Four )
[0208]
The weight average molecular weight of each of the above polymers was measured by gel permeation chromatography (polystyrene standard), and the acid value was 0. 0 in a polymer solution obtained by dissolving each of the above polymers in a DMSO / water mixture having a volume ratio of 54/6. Titrated with 1N aqueous sodium hydroxide solution.
[0209]
<Polymer (P-1, P-3 and P-15)>
Polymer P-1 manufactured by Tokyo Chemical Industry Co., Ltd., P-3 manufactured by Aldrich Co., Ltd., and P-15 manufactured by Sowa Kagaku Co., Ltd. were used.
[0210]
3. Evaluation of polymers used for intermediate layers
With respect to each of the polymers P-1, 3, 8, 12, 14 and 15 obtained above and the polymer compound PA-1 used for the undercoat layer described later, the water-insoluble and alkali described later is obtained by the following method. The presence or absence of interaction with the soluble resin was confirmed. The results are shown in Table 1.
[0211]
As water-insoluble and alkali-soluble resin, m, p-cresol novolak resin (m / p ratio = 6/4, weight average molecular weight 4,5000, containing 0.8 mol% of unreacted cresol) was used, and 5 mass of the resin. % Methanol solution A was prepared.
Moreover, the 5 mass% methanol solution B of the said polymer and polymer compound PA-1 was prepared, respectively.
Next, at 25 ° C., 1 mL of the solution A was added to 1 mL of the solution A and mixed. After 5 minutes, the change of the mixed solution was visually confirmed.
White turbidity of the mixed solution (to the extent that the mixed solution is more opaque than the original solution A or B), formation of a white precipitate in the mixed solution, or formation of a gel in the mixed solution ( The case where any one of the insoluble gel solids can be visually confirmed and a polymer complex is formed (has an interaction) is indicated by “○”, and none of these phenomena can be confirmed. The case where there is no or weak is indicated by “x”.
In Table 1, any polymer indicated by “◯” produced a white precipitate of the corresponding polymer.
[0212]
4). Preparation of lithographic printing plate precursor
<Formation of intermediate layer>
On the lithographic printing plate support obtained above, after applying an intermediate layer coating solution having the following composition containing the polymer used in the intermediate layer obtained above, it was dried at 80 ° C. for 15 seconds, An intermediate layer was provided. The coating amount after drying is 15 mg / m ² Met.
The combination of the lithographic printing plate support and the polymer used for the intermediate layer was performed according to the combinations shown in Table 1.
(Interlayer coating solution composition)
・ 0.3 g of polymer used for the intermediate layer
・ Methanol 100g
・ Water 1g
[0213]
<Formation of thermosensitive layer A>
On the intermediate layer provided on the lithographic printing plate support as described above, the coating amount of the heat-sensitive layer coating liquid A1 having the composition described below in the combination shown in Table 1 is 0.85 g / m. ² After coating, the temperature control coating solution A2 having the composition described below is applied in a coating amount of 0 by setting Wind Control to 7 at PERFECT OVEN PH200 manufactured by Tabai Co., Ltd. and drying at 140 ° C. for 50 seconds. .22g / m ² Then, it was dried at 140 ° C. for 1 minute to provide a heat sensitive layer A.
[0214]
(Thermosensitive layer coating solution A1 composition)
-N- (4-aminosulfonylphenyl) methacrylamide / acrylonitrile / methyl methacrylate copolymer (mass ratio 36/34/30, weight average molecular weight 50,000, acid value 2.65) 2.133 g
-Cyanine dye A represented by the following formula: 0.109 g
・ 4,4'-bishydroxyphenylsulfone 0.126g
・ Tetrahydrophthalic anhydride 0.190g
・ 0.008 g of p-toluenesulfonic acid
・ 3-Methoxy-4-diazodiphenylamine hexafluorophosphate
0.030g
・ The counter ion of ethyl violet is changed to 6-hydroxy-2-naphthalene sulfone 0.100 g
・ Fluorosurfactant (Megafac F-780, 30% solution, manufactured by Dainippon Ink & Chemicals, Inc.) 0.023 g
・ Methyl ethyl ketone 25.41g
・ 13.0 g of 1-methoxy-2-propanol
・ Γ-butyrolactone (204 ° C., 4.12 debye) 13.2 g
[0215]
Embedded image
[0216]
(Thermosensitive layer coating solution A2 composition)
M, p-cresol novolak (m / p ratio = 6/4, weight average molecular weight 45
00, containing 0.8% by mass of unreacted cresol) 0.3479 g
-Cyanine dye A represented by the above structure 0.0192 g
・ Ethyl methacrylate / mono-2- (methacryloyloxy) ethyl koha
Copolymer of succinate (molar ratio 67/32) 1-methoxy-2-propano
0.1403 g of 30% solution
-0.003 g of onium salt A shown by the following structure
-Fluorosurfactant (Megafac F-780, 30% solution, Dainippon Inn
0.015g, manufactured by Ki Chemical Industry Co., Ltd.
・ Fluorine-containing compound (Megafac F-781, manufactured by Dainippon Ink & Chemicals, Inc.) 0.0033 g
・ Methyl ethyl ketone 10.39g
・ 1-methoxy-2-propanol 20.78 g
[0217]
Embedded image
[0218]
<Formation of thermosensitive layer B>
On the intermediate layer provided on the lithographic printing plate support as described above, the coating amount of the heat-sensitive layer coating liquid B having the composition described below in the combination shown in Table 1 is 1.7 g / m. ² Then, it was dried at 150 ° C. for 1 minute to provide a heat sensitive layer B.
[0219]
(Thermosensitive layer coating solution B composition)
-M, p-cresol novolak (m / p ratio = 6/4, weight average molecular weight 7,300, containing 0.4% by mass of unreacted cresol) 0.93 g
・ 0.07 g of vinyl polymer B represented by the following structure
-Infrared absorber (cyanine dye B1) represented by the following structure 0.017 g
・ Infrared absorber (cyanine dye B2) represented by the following structure 0.023 g
・ 2,4,6-Tris (hexyloxy) benzenediazonium-2-hydroxy-4-methoxybenzophenone-5-sulfonate 0.01 g
・ 0.003 g of p-toluenesulfonic acid
・ Cyclohexane-1,2-dicarboxylic anhydride 0.06g
0.015 g of a dye in which the counter anion of Victoria Pure Blue BOH is a 1-naphthalenesulfonic acid anion
・ Fluorine-based surfactant (Megafac F-176, manufactured by Dainippon Ink & Chemicals, Inc.) 0.02g
・ Methyl ethyl ketone 15g
・ 7g of 1-methoxy-2-propanol
[0220]
Embedded image
[0221]
Thus, on the intermediate layer provided on the lithographic printing plate support 1 or 2, the heat-sensitive layer A or B was provided in the combination shown in Table 1, and Example 1 , 2, 6, 7, Reference Examples 3-5 8 lithographic printing plate precursors were obtained.
[0222]
[Comparative Examples 1 and 2]
On the lithographic printing plate support 1 obtained above, an undercoat layer coating solution having the following composition was applied and dried at 80 ° C. for 15 seconds to form a coating film. The coating amount after drying is 15 mg / m ² Met.
[0223]
(Coating solution composition for undercoat layer)
・ The following polymer compound PA-1 0.3 g
・ Methanol 100g
・ Water 1g
[0224]
Embedded image
[0225]
Thus, on the undercoat layer provided on the lithographic printing plate support 1, the above heat-sensitive layer A or B was combined in the combinations shown in Table 1 in the above examples. And reference examples The lithographic printing plate precursors of Comparative Examples 1 and 2 were obtained.
[0226]
[Manufacture of lithographic printing plates]
Each lithographic printing plate precursor obtained above is subjected to a plate surface energy amount of 140 mJ / cm using a TrendSetter 3244 manufactured by CREO. ² And imagewise exposure.
The exposed lithographic printing plate precursor was developed into a developer DT-1 substantially free from alkali metal silicate (PS plate developer from Fuji Photo Film Co., Ltd., Example 1). , 2, 6 Reference examples 3-5 And Comparative Examples 1 and 2), or developer DP-4 containing alkali metal silicate (Developer for PS plate manufactured by Fuji Photo Film Co., Ltd., Example 7) Reference example 8) was developed using an automatic processor 900NP (manufactured by Fuji Photo Film Co., Ltd.) under standard conditions of use to obtain a lithographic printing plate.
[0227]
[Evaluation of planographic printing plates]
Example obtained Reference examples The printing durability and stain resistance of each lithographic printing plate of Comparative Example were evaluated by the following methods.
The results are shown in Table 1.
1. Stain resistance
Using the above lithographic printing plate, printing with DIC-GEOS (s) Crimson ink on a Mitsubishi Diamond F2 printer (manufactured by Mitsubishi Heavy Industries, Ltd.) and visually evaluating the stain on the blanket after printing 10,000 sheets did.
The evaluation was made in five stages of ◎, ○, Δ, Δ ×, and X in order from the one with less dirt on the blanket and excellent stain resistance.
[0228]
2. Printing durability
The above lithographic printing plate was printed on a Lislon printing machine manufactured by Komori Corporation using DIC-GEOS (N) black ink manufactured by Dainippon Ink & Chemicals, Inc. Printing durability was evaluated based on the number of printed sheets at the time when it was recognized.
The case where the number of printed sheets is 90,000 or more is “「 ”, the case where it is 85,000 or more and less than 90,000 is“ ◯ ”, the case where it is 80,000 or more and less than 85,000. The case where “Δ” is less than 80,000 is indicated by “x”.
[0229]
[Table 1]
[0230]
As is clear from Table 1, a lithographic printing plate precursor (Example 1) in which the intermediate layer of the present invention is provided between the lithographic printing plate support and the heat-sensitive layer. , 2, 6, 7, Reference Examples 3-5 In the case of 8), it was possible to improve the printing durability even more than to impair the excellent stain resistance when a lithographic printing plate was used. In particular, when novolac resin is contained in the heat-sensitive layer in contact with the intermediate layer of the present invention (heat-sensitive layer B: Example 1). , 2,6,7 and Reference example 4 , 5 ), The interaction with the intermediate layer of the present invention was strong, and the effect of improving printing durability was great.
Further, the lithographic printing plate precursor of the present invention can be developed using the developer DP-4 containing an alkali metal silicate without damaging excellent stain resistance, and without being damaged. I was able to balance.
[0231]
【The invention's effect】
An image recording layer containing a water-insoluble and alkali-soluble resin is provided on a lithographic printing plate support provided with a hydrophilic treatment layer, and the intermediate layer of the invention containing a compound that interacts with the resin is further provided. The lithographic printing plate precursor according to the present invention provided between the support and the image recording layer can achieve both printing durability and stain resistance at a high level when used as a lithographic printing plate.

Claims (3)

A lithographic printing plate provided with a positive heat-sensitive layer containing an infrared absorbing dye and a water-insoluble and alkali-soluble resin on a support for a lithographic printing plate subjected to a hydrophilization treatment and increasing the solubility in an alkaline aqueous solution by heating. The original version
An intermediate layer containing a compound having a functional group capable of interacting with the water-insoluble and alkali-soluble resin is provided between the lithographic printing plate support and the positive heat-sensitive layer ,
A lithographic printing plate precursor wherein the functional group capable of interacting with the water-insoluble and alkali-soluble resin is a group represented by the following general formula (1) or (4) .
(In the formula, Y represents a single bond or a linking group, Ar is a monovalent group having pyridine as a mother skeleton, and R ₄ and R ₅ are bonded to each other to form the ring structure shown below.)
The lithographic printing plate according to claim 1, wherein the compound having a functional group capable of interacting with the water-insoluble and alkali-soluble resin is a polymer having a functional group capable of interacting with the water-insoluble and alkali-soluble resin in a side chain. Original edition. The lithographic printing plate precursor according to claim 1, wherein the positive heat-sensitive layer contains a novolac resin.