JP2002357894A - Original plate for planographic printing plate and processing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate for a planographic printing plate which does not contaminate an optical system such as an exposer because ablation is prevented as a positive type original plate for an IR laser excellent in both scuffing resistance and sensitivity and capable of direct plate making particularly from digital signals of a computer or the like and to provide a processing method for the original plate. SOLUTION: In the multilayer original plate for a planographic printing plate obtained by disposing an alkali-soluble resin-containing layer and a positive type recording layer containing an IR absorbent and having solubility in an alkaline aqueous solution increased by exposure with infrared laser light in order on a support, the positive type recording layer contains an alkali-soluble novolak resin containing xylenol in a constitutional unit. The original plate is imagewise exposed and developed with an alkaline developing solution containing an organic compound having the action of a pH buffer and a base.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate precursor and a method for processing the same, and more particularly to a positive lithographic printing plate precursor for an infrared laser for so-called direct plate making that can directly make a plate from a digital signal from a computer or the like. More particularly, the present invention relates to a lithographic printing plate precursor that has both excellent scratch resistance and sensitivity and does not contaminate an optical system such as an exposure machine by preventing ablation from occurring, and a method for processing the same.

[0002]

2. Description of the Related Art In recent years, lasers have been remarkably developed.
2. Description of the Related Art Semiconductor lasers are easily available in small size with high output. These lasers are very useful as an exposure light source when making a plate directly from digital data of a computer or the like.

[0003] Positive type lithographic printing plate materials for infrared lasers are:
An essential component is an alkaline aqueous solution-soluble binder resin and an IR dye or the like that absorbs light and generates heat. The IR dye or the like dissolves in the unexposed area (image area) by interaction with the binder resin. In the exposed area (non-image area), the interaction between the IR dye etc. and the binder resin weakens in the exposed area (non-image area) and dissolves in the alkaline developer to form a lithographic printing plate. I do.

However, in such a positive type lithographic printing plate material for an infrared laser, the solubility resistance of the unexposed portion (image portion) to the developing solution and the solubility of the exposed portion (non-image portion) under various use conditions. However, there is a problem that excessive development or poor development is likely to occur due to fluctuations in use conditions. In addition, the surface condition is liable to fluctuate, such as fine scratches, due to touching the surface during handling, etc., but even if such fine scratches or slight surface fluctuations occur, the solubility is improved. As a result, the unexposed portion (image portion) dissolves during development to form scratch marks, which causes a problem of deterioration in printing durability and poor adhesion.

[0005] Such a problem stems from an essential difference in the plate making mechanism between a positive planographic printing plate material for infrared laser and a positive planographic printing plate material made by UV exposure. That is, in a positive lithographic printing plate material made by UV exposure, a binder resin soluble in an aqueous alkaline solution and an onium salt or a quinonediazide compound are essential components. In the image area), not only does it act as a dissolution inhibitor due to the interaction with the binder resin, but in the exposed area (non-image area), it is decomposed by light to generate acid and acts as a dissolution accelerator. Things. On the other hand, the IR dye or the like in the positive type lithographic printing plate material for an infrared laser only functions as a dissolution inhibitor in an unexposed portion (image portion) and does not promote dissolution in an exposed portion (non-image portion). . Therefore, in order to obtain a difference in solubility between the unexposed portion and the exposed portion in the infrared laser positive lithographic printing plate material, a binder resin having high solubility in an alkali developing solution must be used in advance as a binder resin. Not get
There are problems that the scratch resistance is poor and the state before development becomes unstable.

As means for improving these points, Japanese Patent Laid-Open Publication No.
Japanese Patent Application Laid-Open No. 000-35662 and the like disclose that by adding an alkali-soluble novolak resin containing xylenol as a constituent unit to a recording layer, the solubility of the layer is inhibited and the scratch resistance is improved. However, when an alkali-soluble novolak resin containing a xylenol constituent unit is simply added to the recording layer, the scratch resistance is improved, but there is a problem that the sensitivity is lowered. Further, there has been a problem that ablation of the recording layer occurs and contaminates an optical system such as an exposure machine.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the drawbacks of the above-mentioned prior art and to make a plate from a digital signal of a positive type for an infrared laser, especially a computer, etc., which is excellent in both scratch resistance and sensitivity, especially in a computer. An object of the present invention is to provide a lithographic printing plate precursor that does not contaminate an optical system such as an exposure machine due to obstruction of ablation.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have made the recording layer a multilayer structure, and added an infrared absorber and an alkali-soluble novolak resin containing a xylenol constituent unit to the upper layer of the multilayer structure. In such a case, it was found that both the scratch resistance and the sensitivity could be achieved and the ablation could be prevented, and the present invention was completed.

That is, the present invention is as follows. (1) A multilayer lithographic printing plate comprising an alkali-soluble resin-containing layer provided on a support, and a positive-type recording layer containing an infrared absorber and having increased solubility in an alkaline aqueous solution upon exposure to an infrared laser. A lithographic printing plate precursor, wherein the positive recording layer contains an alkali-soluble novolak resin containing xylenol as a constituent unit.

(2) The content of the trimer or less compound in the positive recording layer is 30 to the novolak resin.
% Or less, the lithographic printing plate precursor as described in (1) above. (3) The lithographic printing plate precursor as described in (1) above, wherein the alkali-soluble resin-containing layer contains an onium salt. (4) The lithographic printing plate precursor as described in (1) above, wherein the alkali-soluble resin-containing layer contains an infrared absorber.

(5) An alkali-soluble resin-containing layer is provided on a support, and an infrared-absorbing agent and an alkali-soluble novolak resin containing xylenol as a structural unit are further provided thereon. A lithographic printing plate, characterized in that, after imagewise exposing a multilayer lithographic printing plate precursor provided with a positive recording layer having an increased positive-tone recording layer, it is developed with an alkaline developer containing a pH-buffer organic compound and a base. How to process the master plate.

In the conventional single-layer recording layer, the scratch resistance is improved, but the sensitivity may be lowered. Therefore, in the present invention, an alkali-soluble resin-containing layer is provided in a multilayer structure on a support, and an infrared-absorbing agent and an alkali-soluble novolak resin containing a xylenol constituent unit are contained in the upper layer to reduce heat generation near the surface of the plate material. It is considered that it was possible to effectively utilize and to suppress the decrease in sensitivity while improving the scratch resistance. Further, it is considered that by setting the content of the compound of trimer or less in the upper layer to 30% or less of the novolak resin, the scratch resistance was further improved and ablation was prevented.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The lithographic printing plate precursor according to the present invention comprises an alkali-soluble resin-containing layer (also referred to as a lower layer) on a support, and a positive recording layer containing an infrared absorber and having increased solubility in an alkaline aqueous solution upon exposure to an infrared laser ( Upper layer), the upper layer contains an alkali-soluble novolak resin containing a xylenol structural unit,
The content of the trimer or less compound in the layer is 30% or less based on the novolak resin.

Hereinafter, the alkali-soluble resin-containing layer (lower layer) and the positive recording layer (upper layer) of the lithographic printing plate precursor according to the present invention will be described.
Will be described. In the lithographic printing plate precursor according to the invention, the positive recording layer (upper layer) is provided at a position close to the surface (exposed surface), and the alkali-soluble resin-containing layer (lower layer) is provided at a side close to the support. It is characterized by being. Among these layers, the positive recording layer (upper layer) contains an alkali-soluble novolak resin containing an infrared absorbing dye and a xylenol constituent unit, and preferably, the content of a compound of trimer or less in the layer is such that 30% for
It is as follows.

The components of the lithographic printing plate precursor according to the present invention will be described below. The positive recording layer (upper layer) located above the lithographic printing plate precursor according to the invention contains an alkali-soluble novolak resin containing a xylenol structural unit that inhibits the solubility of the layer, in order to enhance the scratch resistance. .

[Alkali-Soluble Novolak Resin Containing Xylenol Structural Unit] The alkali-soluble novolak resin containing a xylenol constituent unit (hereinafter, appropriately referred to as a xylenol-containing novolak resin) used in the lithographic printing plate precursor according to the present invention contains phenol and phenol. Formaldehyde can be synthesized in the presence of an acidic catalyst in the usual reaction route of synthesis under normal pressure. It is characterized by.

The xylenol in the novolak resin is 6
It may have any structure of the two isomers, but from the viewpoint of improving stability, 3,5- has a relatively high melting point.
Xylenol, 2,3-xylenol, 2,5-xylenol, and 3,4-xylenol are preferred. The xylenol-containing novolak resin has a weight average molecular weight of 50.
It is preferably from 0 to 10,000. When the weight average molecular weight is less than 500, the effect of improving printing durability becomes insufficient, and
If it exceeds 0000, developability tends to decrease, and both are not preferred.

The content of the xylenol monomer is not particularly limited, and the effect of improving the stability over time is recognized when the content of the xylenol monomer is small, and the effect of improving the stability over time is improved as the content of the xylenol increases. When the proportion of the xylenol-containing novolak resin in the alkali-soluble resin constituting the upper layer of the lithographic printing plate precursor of the present invention is Y% by weight, and the content of the xylenol monomer in the novolak resin is X% by weight, X × Y Is preferably 500 or more (X × Y ≧ 500). That is, when all of the alkali-soluble resin is the xylenol-containing novolak resin (Y =
100% by weight), and xylenol is preferably contained in the novolak resin in an amount of 5% by weight or more from the viewpoint of the effect. In addition, as the xylenol content increases, the tendency that the developability decreases may be recognized.
By adjusting the activity of the developer, a good image can be formed, and since the printing durability tends to improve as the developability decreases, the content of xylenol is adjusted to the target lithographic printing plate. What is necessary is just to select suitably according to the characteristic of the original plate.

The xylenol-containing novolak resin is
Preferably 10 to 99% by weight, more preferably 15 to 95% by weight, of the total solid content of the upper layer of the lithographic printing plate precursor according to the invention,
Particularly preferably, it is used in an amount of 20 to 90% by weight. If the amount of the alkali-soluble polymer compound is less than 30% by weight, the durability of the recording layer deteriorates, and if it exceeds 99% by weight, both sensitivity and durability are not preferred. In addition, when the upper layer in the present invention is obtained as a binder by mixing an alkali-soluble resin other than the xylenol-containing novolak resin described below with the xylenol-containing novolak resin as a binder, the content of the entire binder in the total solid content of the upper layer is as described above. It is desirable to be within the range.

In the positive recording layer (upper layer) of the lithographic printing plate precursor according to the present invention, the content of a compound or less, which is a monomer which causes ablation and inhibits inhibition (dissolution inhibition), is as follows: It is 30% or less based on the novolak resin. It is more preferably at most 20%. More preferably, it is 10% or less. If the content is 30% or more, the optical system of the exposure machine may be contaminated by ablation. When the content is 20% or more, the risk of ablation is reduced, but the components of trimer or less promote development, and there is a concern about the image forming ability. For this reason,
It is more preferably at most 20%. In order to eliminate the above concept, 10% or less is more preferable.

[Infrared absorbing dye] The infrared absorbing dye contained in the upper layer of the lithographic printing plate precursor of the present invention is not particularly limited as long as it is a dye that absorbs infrared light and generates heat. Various known dyes can be used.

As the infrared absorbing dye according to the present invention, commercially available dyes and known dyes described in literatures (for example, "Dye Handbook" edited by The Society of Synthetic Organic Chemistry, 1970) can be used. Specifically, azo dye, metal complex salt azo dye, pyrazolone azo dye, anthraquinone dye, phthalocyanine dye, carbonium dye, quinone imine dye,
Dyes such as methine dye and cyanine dye are exemplified. In the present invention, among these dyes, those that absorb infrared light or near-infrared light are particularly preferable because they are suitable for use in lasers that emit infrared light or near-infrared light.

Examples of such a dye absorbing infrared light or near infrared light include, for example, JP-A-58-125246.
JP-A-59-84356, JP-A-59-2028
29, JP-A-60-78787, JP-A-58-173696 and JP-A-5-173696.
Methine dyes described in JP-A-8-181690 and JP-A-58-194595;
JP-A-58-224793, JP-A-59-481
No. 87, JP-A-59-73996, JP-A-60-52
No. 940, naphthoquinone dyes described in JP-A-60-63744, squarylium dyes described in JP-A-58-112792, British Patent 43
And the cyanine dyes described in U.S. Pat.

Further, as a dye, US Pat.
No. 938 is also preferably used, and substituted arylbenzo (thio) pyrylium salts described in U.S. Pat. No. 3,881,924;
No. 42645 (U.S. Pat. No. 4,327,169), a trimethinethiapyrylium salt described in JP-A-58-1810.
No. 51, No. 58-220143, No. 59-41363
Nos. 59-84248, 59-84249, 59-146063, and 59-146061 and pyrylium compounds described in JP-A-59-2161.
No. 46, a cyanine dye disclosed in U.S. Pat. No. 4,283,4.
No. 75, pentamethine thiopyrylium salt and the like, and Japanese Patent Publication Nos. 5-135514 and 5-19702, pyrylium compounds and the like, as commercial products, Epolin III-178 by Eporin, Epoli
Ght III-130, Epollight III-125 and the like are particularly preferably used. Another particularly preferred example of the dye is a near-infrared absorbing dye described as formulas (I) and (II) in US Pat. No. 4,756,993.

The amount of addition in the recording layer is 0.01 to 50% by weight, preferably 0.1 to 10% by weight, particularly preferably 0.5 to 10% by weight based on the total solid content of the recording layer. Can be added. If the amount of the dye is less than 0.01% by weight, the sensitivity is lowered, and if it exceeds 50% by weight, the uniformity of the recording layer is lost and the durability of the recording layer is deteriorated.

In the positive recording layer (upper layer) of the lithographic printing plate precursor according to the present invention, it interacts with novolak for the purpose of further increasing the inhibition (inhibition of solubility) due to the introduction of the xylenol structure. Preferably, a quaternary ammonium salt is added. The addition amount is preferably from 0.1 to 50%, more preferably from 1 to 30%, of the total solid content of the upper layer.
If it is 0.1% or less, the increase in the interaction decreases, which is not preferable. Further, when it is added in an amount of 50% or more, it may adversely affect the film forming property of the binder.

The quaternary ammonium salt is not particularly limited, but may be a tetraalkylammonium salt, a trialkylarylammonium salt, a dialkyldiarylammonium salt, an alkyltriarylammonium salt, a tetraarylammonium salt, a cyclic ammonium salt, a bicyclic ammonium salt. Is mentioned. Specifically, tetrabutylammonium bromide, tetrapentylammonium bromide, tetrahexylammonium bromide,
Tetraoctyl ammonium bromide, tetralauryl ammonium bromide, tetraphenyl ammonium bromide, tetranaphthyl ammonium bromide, tetrabutyl ammonium chloride, tetrabutyl ammonium iodide, tetrastearyl ammonium bromide,
Lauryl trimethyl ammonium bromide, stearyl trimethyl ammonium bromide, behenyl trimethyl ammonium bromide, lauryl triethyl ammonium bromide, phenyl trimethyl ammonium bromide, 3-trifluoromethyl phenyl trimethyl ammonium bromide, benzyl trimethyl ammonium bromide, dibenzyl dimethyl ammonium bromide, distearyl dimethyl ammonium Bromide, tristearylmethylammonium bromide, benzyltriethylammonium bromide, hydroxyphenyltrimethylammonium bromide, N-methylpyridinium bromide and the like.

Further, in the positive recording layer (upper layer) of the lithographic printing plate precursor according to the present invention, interaction with novolak is intended to further increase the inhibition (inhibition of solubility) due to the introduction of a xylenol structure. It is preferable to add a polyethylene glycol-based compound. The amount added is preferably from 0.1 to 50%, more preferably from 1 to 30%, of the solid content based on the total solid content of the upper layer. If it is 0.1% or less, the increase in interaction is small, which is not preferable. When added in an amount of 50% or more, the polyethylene glycol compound which cannot interact with the binder promotes the penetration of the developer and may adversely affect image forming properties.

As the polyethylene glycol compound,
Although not particularly limited, those having the following structures are exemplified.

R ¹ -{-O- (R ³ -O-) _m -R ² ｝ _n

[0031] (R ¹ is a polyhydric alcohol residue or a polyhydric phenol residue, R ² is a hydrogen atom, an alkyl group which may have a substituent C ₁ ~ _25, an alkenyl group, an alkynyl group, alkyloyl group, An aryl group or an aryloyl group, and R ³ represents an alkylene residue which may have a substituent; m is an integer of 10 or more, and n is an integer of 1 to 4 on average)

Examples of the polyethylene glycol compound having the above structure include polyethylene glycols, polypropylene glycols, polyethylene glycol alkyl ethers, polypropylene glycol alkyl ethers, polyethylene glycol aryl ethers, polypropylene glycol aryl ethers, and polyethylene glycol alkyl aryl. Ethers, polypropylene glycol alkylaryl ethers, polyethylene glycol glycerin esters, polypropylene glycol glycerin esters, polyethylene sorbitol esters, polypropylene glycol sorbitol esters, polyethylene glycol fatty acid esters, polypropylene glycol fatty acid esters, polyethylene glycol Ethylenediamines, polypropylene glycolated ethylenediamines, polyethylene glycolated diethylenetriamine, and polypropylene glycol diethylenetriamines.

Specific examples of these are polyethylene glycol 1000, polyethylene glycol 2000,
Polyethylene glycol 4000, polyethylene glycol 10,000, polyethylene glycol 20,000,
Polyethylene glycol 5000, polyethylene glycol 100,000, polyethylene glycol 20,000
0, polyethylene glycol 500000, polypropylene glycol 1500, polypropylene glycol 3
000, polypropylene glycol 4000, polyethylene glycol methyl ether, polyethylene glycol ethyl ether, polyethylene glycol phenyl ether, polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol diphenyl ether, polyethylene glycol lauryl ether, polyethylene glycol dilauryl ether, polyethylene glycol nonyl ether,
Polyethylene glycol cetyl ether, polyethylene glycol stearyl ether, polyethylene glycol distearyl ether, polyethylene glycol behenyl ether, polyethylene glycol dibehenyl ether, polypropylene glycol methyl ether, polypropylene glycol ethyl ether, polypropylene glycol phenyl ether, polypropylene glycol dimethyl ether, polypropylene glycol diethyl ether , Polypropylene glycol diphenyl ether, polypropylene glycol lauryl ether, polypropylene glycol dilauryl ether, polypropylene glycol nonyl ether, polyethylene glycol acetyl ester, polyethylene glycol diacetyl ester, Ethylene glycol benzoate, polyethylene glycol lauryl ester, polyethylene glycol dilauryl ester, polyethylene glycol nonylate, polyethylene glycol cetylate, polyethylene glycol stearoyl ester, polyethylene glycol distearoyl ester, polyethylene glycol behenate, polyethylene glycol dibehenate Acid ester, polypropylene glycol acetyl ester, polypropylene glycol diacetyl ester, polypropylene glycol benzoate, polypropylene glycol dibenzoate, polypropylene glycol laurate, polypropylene glycol dilaurate,
Polypropylene glycol nonylate, polyethylene glycol glycerin ether, polypropylene glycol glycerin ether, polyethylene glycol sorbitol ether, polypropylene glycol sorbitol ether, polyethylene glycolated ethylene diamine, polypropylene glycolated ethylene diamine, polyethylene glycolated diethylene triamine,
Examples include polypropylene glycolated diethylenetriamine and polyethylene glycolated pentamethylenehexamine.

Further, when a measure to increase the inhibition (inhibition of solubility) by introducing the above xylenol structure or the like is performed, the sensitivity is lowered. In this case, it is effective to add a lactone compound. When the developer penetrates into the exposed area, the lactone compound reacts with the lactone compound to generate a new carboxylic acid compound, thereby improving the sensitivity. The addition amount is preferably from 0.1 to 50%, more preferably from 1 to 30%, as a solid content based on the total solid content of the upper layer. When the content is less than 0.1%, the effect is small. When the content is more than 50%, the lactone structure cannot interact with each other, so that the image forming property is poor. Since this compound reacts with the developing solution, it is desired to selectively contact the developing solution.

The lactone compound is not particularly limited, but includes compounds represented by the following general formula (I) or general formula (II).

[0036]

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[0037]

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In the general formula (I) or the general formula (II),
X ¹ , X ² , X ³ and X ⁴ are the constituent atoms or atomic groups of the ring, which may be the same or different, may each independently have a substituent, and have the general formula (I) At least one of X ¹ , X ² and X ³ and X ¹ ,
At least one of X ² , X ³ and X ⁴ has an electron-withdrawing substituent or a substituent substituted with an electron-withdrawing group.
The ring-constituting atoms or atomic groups represented by X ¹ , X ² , X ³ and X ⁴ are non-metallic atoms having two single bonds for forming a ring or atomic groups containing the non-metallic atoms. Preferred non-metallic atoms or non-metallic atomic groups are atoms or atomic groups selected from methylene, sulfinyl, carbonyl, thiocarbonyl, sulfonyl, sulfur, oxygen and selenium atoms, more preferably It is an atomic group selected from a methylene group, a carbonyl group and a sulfonyl group.

[0039] X ¹ in at least one or the general formula X ^1, X ² and X ³ in the general formula (I) (II), X 2, X 3
And at least one of X ⁴ has an electron-withdrawing group.
In this specification, an electron-withdrawing substituent refers to a group having a positive Hammett's substituent constant σp. Regarding Hammett's substituent constant, see Journal of Medicinal Chemistry, 19
73, Vol. 16, No. 11, 1207-1216, etc. can be referred to. Examples of the electron-withdrawing group having a positive Hammett's substituent constant σp include, for example, a halogen atom (a fluorine atom (σp
Value: 0.06), chlorine atom (σp value: 0.23), bromine atom (σp value: 0.23), iodine atom (σp value: 0.
18)), a trihaloalkyl group (tribromomethyl (σ
p value: 0.29), trichloromethyl (σp value: 0.3)
3), trifluoromethyl (σp value: 0.54)), cyano group (σp value: 0.66), nitro group (σp value: 0.
78), an aliphatic / aryl or heterocyclic sulfonyl group (for example, methanesulfonyl (σp value: 0.72)),
Aliphatic / aryl or heterocyclic acyl group (for example, acetyl (σp value: 0.50), benzoyl (σp value:
0.43)), an alkynyl group (for example, C≡CH (σp
Value: 0.23)), an aliphatic / aryl or heterocyclic oxycarbonyl group (for example, methoxycarbonyl (σp
Value: 0.45), phenoxycarbonyl (σp value: 0.
44)), a carbamoyl group (σp value: 0.36), a sulfamoyl group (σp value: 0.57), a sulfoxide group,
Examples include a heterocyclic group, an oxo group, and a phosphoryl group.

Preferred electron-withdrawing groups are an amide group, an azo group, a nitro group, a C1-5 fluoroalkyl group, a nitrile group, a C1-5 alkoxycarbonyl group, and a C1-5 acyl group. An alkylsulfonyl group having 1 to 9 carbon atoms, an arylsulfonyl group having 6 to 9 carbon atoms, an alkylsulfinyl group having 1 to 9 carbon atoms, an arylsulfinyl group having 6 to 9 carbon atoms, and an arylcarbonyl group having 6 to 9 carbon atoms A thiocarbonyl group, a fluorinated alkyl group having 1 to 9 carbon atoms, a fluorinated aryl group having 6 to 9 carbon atoms, and 3 carbon atoms
To fluorinated allyl, oxo, and halogen elements. More preferably, a nitro group, a C1-5 fluoroalkyl group, a nitrile group, a C1
To 5 alkoxycarbonyl groups, 1 to 5 carbon acyl groups, 6 to 9 arylsulfonyl groups, 6 to 6 carbon atoms
9 is a group selected from the group consisting of an arylcarbonyl group, an oxo group and a halogen element. Hereinafter, specific examples of the compound represented by Formula (I) or Formula (II) are shown, but the present invention is not limited to these compounds.

[0041]

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[0042]

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The compounds represented by formula (I) or (II) may be used either alone or in combination.
Further, two or more compounds of the general formula (I) or two or more compounds of the general formula (II) may be used in combination at any ratio within the above-mentioned total addition amount.

In addition, the upper layer of the lithographic printing plate precursor according to the present invention may contain the same alkali-soluble polymer compound as that contained in the lower layer to such an extent that the action of the present invention is not impaired. The alkali-soluble polymer compound is as described below.

Next, the alkali-soluble resin-containing layer (lower layer) of the lithographic printing plate precursor according to the invention will be described. [Alkali-soluble polymer compound] The lower layer of the lithographic printing plate precursor according to the invention contains a water-insoluble and alkali-water-soluble polymer compound (hereinafter, also referred to as an alkali-soluble polymer or an alkali-soluble resin as appropriate). . The alkali-soluble polymer includes a homopolymer containing an acidic group in a main chain and / or a side chain in the polymer, a copolymer thereof, or a mixture thereof. Therefore, the lower layer according to the present invention has a property of dissolving when contacted with an alkaline developer. The alkali-soluble polymer used in the lower layer of the present invention is not particularly limited as long as it is a conventionally known one. It is preferable that the polymer is a polymer compound having the functional group in the molecule. For example, the following are exemplified, but the present invention is not limited thereto.

(1) Examples of the high molecular compound having a phenolic hydroxyl group include phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin, phenol / cresol (m
-, P-, or m- / p-mixture). Novolak resins such as mixed formaldehyde resins and pyrogallol acetone resins. As the high molecular compound having a phenolic hydroxyl group, a high molecular compound having a phenolic hydroxyl group in a side chain is preferably used. As the high molecular compound having a phenolic hydroxyl group in the side chain, a polymerizable monomer composed of a low molecular compound having at least one unsaturated bond capable of polymerizing with the phenolic hydroxyl group may be homopolymerized, or another polymerizable monomer may be used. Examples include a polymer compound obtained by copolymerizing a monomer.

Examples of the polymerizable monomer having a phenolic hydroxyl group include acrylamide, methacrylamide, acrylate, methacrylate, and hydroxystyrene having a phenolic hydroxyl group. Specifically, N- (2-hydroxyphenyl) acrylamide, N- (3-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) acrylamide, N- (2-hydroxyphenyl) methacrylamide, N- (3 -Hydroxyphenyl) methacrylamide, N- (4-hydroxyphenyl) methacrylamide, o-hydroxyphenyl acrylate, m-hydroxyphenyl acrylate, p-hydroxyphenyl acrylate, o-hydroxyphenyl methacrylate,
m-hydroxyphenyl methacrylate, p-hydroxyphenyl methacrylate, o-hydroxystyrene,
m-hydroxystyrene, p-hydroxystyrene, 2
-(2-hydroxyphenyl) ethyl acrylate, 2
-(3-hydroxyphenyl) ethyl acrylate, 2
-(4-hydroxyphenyl) ethyl acrylate, 2
-(2-hydroxyphenyl) ethyl methacrylate,
2- (3-hydroxyphenyl) ethyl methacrylate, 2- (4-hydroxyphenyl) ethyl methacrylate and the like can be suitably used. Such resins having a phenolic hydroxyl group may be used in combination of two or more. No. 4,123,279.
As described in the specification, a condensation polymer of phenol and formaldehyde having an alkyl group having 3 to 8 carbon atoms as a substituent, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, may be used in combination. Good.

(2) As the alkali-soluble polymer compound having a sulfonamide group, a polymer compound obtained by homopolymerizing a polymerizable monomer having a sulfonamide group or copolymerizing the monomer with another polymerizable monomer is used. Is mentioned. Examples of the polymerizable monomer having a sulfonamide group include a sulfonamide group having at least one hydrogen atom bonded to a nitrogen atom in one molecule, —NH—SO ₂ —.
And a polymerizable monomer composed of 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 substituted or monosubstituted aminosulfonyl group or a substituted sulfonylimino group is preferable.

(3) The alkali-soluble polymer compound having an active imide group is preferably one having an active imide group in the molecule, and the polymer compound is preferably an unsaturated polymerizable with an active imide group in one molecule. A polymer compound obtained by homopolymerizing a polymerizable monomer composed of a low-molecular compound having at least one bond, or by copolymerizing the monomer with another polymerizable monomer is exemplified.

As such a compound, specifically,
N- (p-toluenesulfonyl) methacrylamide, N
-(P-Toluenesulfonyl) acrylamide and the like can be suitably used.

Further, as the alkali-soluble polymer compound of the present invention, at least two of the above-mentioned polymerizable monomers having a phenolic hydroxyl group, polymerizable monomers having a sulfonamide group, and polymerizable monomers having an active imide group can be used. It is preferable to use a polymer compound obtained by polymerizing the above, or a polymer compound obtained by copolymerizing another polymerizable monomer with two or more polymerizable monomers. When a polymerizable monomer having a sulfonamide group and / or a polymerizable monomer having an active imide group is copolymerized with a polymerizable monomer having a phenolic hydroxyl group, the mixing weight ratio of these components is from 50:50 to 5: It is preferably in the range of 95, particularly preferably in the range of 40:60 to 10:90.

In the present invention, the alkali-soluble polymer is a copolymer of a polymerizable monomer having a phenolic hydroxyl group, a polymerizable monomer having a sulfonamide group, or a polymerizable monomer having an active imide group with another polymerizable monomer. In the case of a polymer, the content of the monomer for imparting alkali solubility is preferably at least 10 mol%, more preferably at least 20 mol%. If the monomer component imparting alkali solubility is less than 10 mol%, alkali solubility tends to be insufficient, and the effect of improving development latitude may not be sufficiently achieved.

The monomer components to be copolymerized with the above-mentioned polymerizable monomer having a phenolic hydroxyl group, a polymerizable monomer having a sulfonamide group, or a polymerizable monomer having an active imide group are listed in the following (m1) to (m12). Examples of the compound include, but are not limited to, compounds. (M1) Acrylic esters and methacrylic esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate. (M2) methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate,
Alkyl acrylates such as hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate and glycidyl acrylate; (M3) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, methacrylic acid-2-
Alkyl methacrylates such as chloroethyl and glycidyl methacrylate; (M4) acrylamide, methacrylamide, N-methylolacrylamide, N-ethylacrylamide, N
-Hexyl methacrylamide, N-cyclohexyl acrylamide, N-hydroxyethyl acrylamide, N
Acrylamide or methacrylamide such as -phenylacrylamide, N-nitrophenylacrylamide, and N-ethyl-N-phenylacrylamide.

(M5) 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. (M6) vinyl acetate, vinyl chloroacetate,
Vinyl esters such as vinyl butyrate and vinyl benzoate. (M7) Styrenes such as styrene, α-methylstyrene, methylstyrene, and chloromethylstyrene. (M8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone. (M9) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene. (M10) N-vinylpyrrolidone, acrylonitrile,
Methacrylonitrile and the like. (M11) Unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide. (M12) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride and itaconic acid.

As the alkaline water-soluble polymer compound,
It is preferable to have a phenolic hydroxyl group, for example,
Phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin,
Phenol / cresol (m-, p-, or m- / p-
Novolak resins such as mixed formaldehyde resins and pyrogallol acetone resins are preferred.

Further, as the alkali water-soluble polymer compound having a phenolic hydroxyl group, further, as described in US Pat. No. 4,123,279,
C3 to C3 such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin
And polycondensates of phenol and formaldehyde having an alkyl group of 8 as a substituent. As a method for copolymerizing the alkali water-soluble polymer compound, a conventionally known graft copolymerization method, block copolymerization method, random copolymerization method, or the like can be used.

In the present invention, the alkali-soluble polymer is
In the case of a homopolymer or copolymer of the polymerizable monomer having a phenolic hydroxyl group, the polymerizable monomer having a sulfonamide group, or the polymerizable monomer having an active imide group, the weight average molecular weight is 2,000 or more, and the number average Those having a molecular weight of 500 or more are preferred. More preferably, the weight average molecular weight is 5,000 to 300,000, the number average molecular weight is 800 to 250,000, and the degree of dispersion (weight average molecular weight / number average molecular weight) is 1.1 to 10. . In the present invention, when the alkali-soluble polymer is a resin such as a phenol formaldehyde resin and a cresol aldehyde resin, the weight average molecular weight is 500 to
20,000 and a number average molecular weight of 200 to 10,000
00 is preferred.

As the alkali-soluble polymer used in the lower layer, an acrylic resin can favorably maintain the solubility of the lower layer in an alkali developing solution containing an organic compound having a buffering action and a base as main components. It is preferable from the viewpoint of image formation during development. Further, a resin having a sulfoamide group is particularly preferable as the acrylic resin.

Each of these alkali-soluble polymer compounds may be used alone or in combination of two or more. The total solid content of the lower layer is 30 to 99% by weight, preferably 40 to 95% by weight, and particularly preferably. Is used in an amount of 50 to 90% by weight. If the addition amount of the alkali-soluble polymer is less than 30% by weight, the durability of the lower layer is deteriorated, and if it exceeds 99% by weight, it is not preferable in terms of both sensitivity and durability.

[Other Components] In forming the upper layer or the lower layer, in addition to the above essential components, various additives may be further added, if necessary, as long as the effects of the present invention are not impaired. it can. The additive may be contained only in the lower layer, or may be contained only in the upper layer. Further, it may be contained in both layers. Hereinafter, an example of the additive will be described. For example, a thermally decomposable substance such as an onium salt, an o-quinonediazide compound, an aromatic sulfone compound, an aromatic sulfonic acid ester compound, and a substance that substantially lowers the solubility of an alkali water-soluble polymer compound when not decomposed is used in combination. This is preferable from the viewpoint of improving the dissolution inhibiting property of the image area in the developing solution. Examples of onium salts include diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, arsonium salts, and the like.

Preferable onium salts for use in the present invention include, for example, SI Schlesinger,
Photogr. Sci. Eng., 18, 387 (1974), TS Bal et a
1, Polymer, 21, 423 (1980), JP-A-5-158230
No. 4,069,055 diazonium salt described in U.S. Pat.
No. 4,069,056, and ammonium salts described in the specification of JP-A-3-140140, DC Necker et al, Macr.
omolecules, 17, 2468 (1984), CS Wen et al, Teh,
Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (198
8), U.S. Pat.Nos. 4,069,055 and 4,069,056, phosphonium salts described in JVCrivello et al, Macromorecule
s, 10 (6), 1307 (1977), Chem. & Eng. News, Nov. 28,
p31 (1988), EP 104,143, U.S. Patent 339,04
No. 9, 410,201, JP-A-2-150848, JP-A-2-296
No. 514, an iodonium salt, JVCrivello et al,
Polymer J. 17, 73 (1985), JV Crivello et al. J.
Org.Chem., 43, 3055 (1978), WR Watt et al, J.
Polymer Sci., PolymerChem.Ed., 22, 1789 (1984),
JV Crivello et al, Polymer Bull., 14, 279 (198
5), JV Crivello et al, Macromorecules, 14 (5)
, 1141 (1981), JV Crivello et al, J. Polymer Sc
i., Polymer Chem. Ed., 17, 2877 (1979), European Patent No.
370,693, 233,567, 297,443, 297,442
Nos., U.S. Pat.Nos. 4,933,377, 3,902,114, 410,20
No. 1, No. 339,049, No. 4,760,013, No. 4,734,444, No.
2,833,827, German Patent No. 2,904,626, 3,604,580
No. 3,604,581, JV Cri
vello et al, Macromorecules, 10 (6), 1307 (1977), J.
V. Crivello et al, J. Polymer Sci., Polymer Chem.
Ed., 17, 1047 (1979).
S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p
478 Tokyo, Oct (1988). Of the onium salts, diazonium salts are particularly preferred. Particularly preferred diazonium salts include those described in JP-A-5-158230.

As the counter ion of the onium salt, tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid,
-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 and the like can be mentioned. Among them, alkyl aromatic sulfonic acids such as hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid and 2,5-dimethylbenzenesulfonic acid are particularly preferable. The onium salt may be added to either the upper layer or the lower layer, but the lower layer is preferred from the viewpoint of image forming properties.

Suitable quinonediazides include o-quinonediazide compounds. The o-quinonediazide compound used in the present invention is a compound having at least one o-quinonediazide group, which increases alkali solubility by thermal decomposition, and can be a compound having various structures. In other words, o-quinonediazide assists the solubility of the light-sensitive material system by both the effect of losing the ability to suppress the dissolution of the binder by thermal decomposition and the fact that o-quinonediazide itself changes to an alkali-soluble substance. Examples of the o-quinonediazide compound used in the present invention include those described in J. Am. The compounds described in "Light-Sensitive Systems" by John Coleyer (John Wiley & Sons. Inc.), pages 339-352, can be used, but are particularly suitable for reacting with various aromatic polyhydroxy compounds or aromatic amino compounds. Sulfonic acid esters or amides of quinonediazides are preferred. Also, benzoquinone (1,2) -diazidesulfonic acid chloride or naphthoquinone- (1,1) described in JP-B-43-28403.
2) esters of -diazide-5-sulfonic acid chloride with pyrogallol-acetone resin, U.S. Pat. No. 3,046,12
No. 0 and 3,188,210, esters of benzoquinone- (1,2) -diazidesulfonic acid chloride or naphthoquinone- (1,2) -diazide-5-sulfonic acid chloride with phenol-formaldehyde resin. It is preferably used.

Further, esters of naphthoquinone- (1,2) -diazide-4-sulfonic acid chloride with phenol formaldehyde resin or cresol-formaldehyde resin, naphthoquinone- (1,2) -diazide-
Esters of 4-sulfonic acid chloride with pyrogallol-acetone resin are likewise preferably used. Other 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-48-965
No. 75, JP-A-49-38701, JP-A-48-13354, Japanese Patent Publication No.
41-11222, JP-B-45-9610, JP-B-49-17481,
U.S. Pat.Nos. 2,797,213, 3,454,400, 3,544,
No. 323, No. 3,573,917, No. 3,674,495, No. 3,78
No. 5,825, British Patent No. 1,227,602, No. 1,251,345,
No. 1,267,005, No. 1,329,888, No. 1,330,932
And German Patent No. 854,890.

The amount of the o-quinonediazide compound added is preferably 1 to 50% by weight, more preferably 5 to 30% by weight, particularly preferably 1 to 50% by weight, based on the total solids forming the layer.
It is in the range of 0 to 30% by weight. These compounds can be used alone, but may be used as a mixture of several kinds.

The amount of additives other than the o-quinonediazide compound is preferably 1 to 50% by weight, more preferably 5 to 30% by weight, particularly preferably 10 to 30% by weight. The additive of the present invention and the alkali-soluble polymer are preferably contained in the same layer.

For the purpose of enhancing the discrimination of the image and the resistance to the surface flaw, a perfluoro compound having 3 to 20 carbon atoms in the molecule as described in JP-A-2000-187318 is used. It is preferable to use a polymer having a (meth) acrylate monomer having two or three alkyl groups as a polymerization component. Such a compound may be contained in either the upper layer or the lower layer, but more effective is to include it in the upper layer. The amount added is preferably from 0.1 to 10% by weight, more preferably from 0.5 to 5% by weight, in the upper layer material.

In the printing plate material of the present invention, a compound which lowers the coefficient of static friction of the surface can be added for the purpose of imparting resistance to scratches. In particular,
Examples thereof include esters of long-chain alkyl carboxylic acids as used in US Pat. No. 6,117,913. Such a compound may be contained in either the lower layer or the upper layer, but more effective is to include it in the upper layer. The preferred amount of addition is from 0.1 to 10% by weight of the material forming the layer. More preferably, it is 0.5-5% by weight.

The lower layer or the upper layer in the present invention may contain a compound having a low molecular weight acidic group, if necessary. Sulfonic acid, carboxylic acid,
A phosphate group can be mentioned. Among them, compounds having a sulfonic acid group are preferred. Specific examples include aromatic sulfonic acids such as p-toluenesulfonic acid and naphthalenesulfonic acid and aliphatic sulfonic acids. Such a compound may be contained in either the lower layer or the upper layer. The addition amount is preferably 0.05 to 5% by weight in the material forming the layer, more preferably 0.1 to 5% by weight.
1 to 3% by weight. If it is more than 5%, the solubility of each layer in the developer increases, which is not preferable.

In the present invention, various dissolution inhibitors may be contained for the purpose of adjusting the solubility of the lower layer or the upper layer. Examples of the dissolution inhibitor include JP-A-11-119418.
A disulfone compound or a sulfone compound as disclosed in JP-A No. 5-2,078 is preferably used, and as a specific example, 4,4′-bishydroxyphenyl sulfone is preferably used. Such a compound may be contained in either the lower layer or the upper layer. It is preferable that the content of each layer is 0.05 to 20% by weight in the material constituting the layer.
More preferably, it is 0.5 to 10% by weight.

For the purpose of further improving the sensitivity, cyclic acid anhydrides, phenols and organic acids can be used in combination. Examples of the cyclic acid anhydride include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-endooxy-Δ4-tetrahydrophthalic anhydride, and tetrachlorophthalic anhydride described in U.S. Patent No. 4,115,128. , Maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride, and the like. As phenols, bisphenol A, p-nitrophenol, p-nitrophenol
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 and the like can be mentioned. Further, as organic acids, JP-A-60-88942 and JP-A-Hei 2
Sulfonic acids described in -96755 and the like,
There are sulfinic acids, alkyl sulfates, phosphonic acids, phosphoric esters and carboxylic acids, and specifically, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethyl sulfate, phenylphosphonic acid, Phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid, p-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 4-cyclohexene-
Examples thereof include 1,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, and ascorbic acid. The proportion of the above-mentioned cyclic acid anhydride, phenols and organic acids in the material constituting the layer is preferably 0.05 to 20% by weight, more preferably 0.1 to 15% by weight, particularly preferably 0.1 to 15% by weight. 1 to 10% by weight.

Further, in the lower layer or upper layer coating solution according to the present invention, in order to widen the stability of processing under development conditions,
JP-A-62-251740 and JP-A-3-2085
Non-ionic surfactants described in JP-A No. 14-114, JP-A No. 59-121044, JP-A No. 4-13
No. 149, an amphoteric surfactant,
A siloxane-based compound as described in EP950517 and a fluorine-containing monomer copolymer as described in JP-A-11-288093 can be added. Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, monoglyceride stearic acid, and polyoxyethylene nonyl phenyl ether. Specific examples of the amphoteric surfactant include:
Alkyl di (aminoethyl) glycine, alkyl polyaminoethyl glycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N-tetradecyl-N, N-betaine type (for example, trade name "Amogen K ": Manufactured by Daiichi Kogyo Co., Ltd.).

The siloxane-based compound is preferably a block copolymer of dimethylsiloxane and polyalkylene oxide. Specific examples include DBE- made by Chisso Corporation.
224, DBE-621, DBE-712, DBP-7
32, DBP-534, manufactured by Tego, Germany, Tego G
and polyalkylene oxide-modified silicones such as LIDE100. The ratio of the nonionic surfactant and the amphoteric surfactant in the coating liquid material is 0.1%.
It is preferably from 0.5 to 15% by weight, more preferably from 0.1 to 15% by weight.
5% by weight.

In the lower or upper layer of the present invention, a printing-out agent for obtaining a visible image immediately after heating by exposure, or a dye or pigment as an image coloring agent can be added. Representative examples of the printing-out agent include a combination of a compound that releases an acid by heating upon exposure (photoacid releasing agent) and an organic dye that can form a salt. Specifically, o-naphthoquinonediazide-4 described in JP-A-50-36209 and JP-A-53-8128 is disclosed.
A combination of a sulfonic acid halide and a salt-forming organic dye, and JP-A-53-36223 and JP-A-54-74728.
No. 60-3626, No. 61-143748, No. 61-151644 and No. 63-58440 in combination with the trihalomethyl compounds and salt-forming organic dyes. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent temporal stability and give clear print-out images.

As the colorant for the image, other dyes can be used in addition to the above-mentioned salt-forming organic dyes. Suitable dyes, including salt-forming organic dyes, include oil-soluble dyes and basic dyes. Specifically, 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 (all manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, crystal violet (CI42555), methyl Violet (CI42535), ethyl violet, rhodamine B (CI145170B), malachite green (CI42000), methylene blue (CI5201)
5) and the like. Also, Japanese Unexamined Patent Publication No. Sho 62-2
The dyes described in JP 93247 A are particularly preferred. These dyes are used in an amount of 0.1 to the total solid content of the printing plate material.
It can be added to the printing plate material in a proportion of from 01 to 10% by weight, preferably from 0.1 to 3% by weight. Further, a plasticizer is added to the printing plate material of the present invention, if necessary, in order to impart flexibility and the like to the coating film. 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 Oligomers and polymers are used.

The upper and lower layers of the lithographic printing plate precursor according to the invention can be usually formed by dissolving each of the above-mentioned components in a solvent and coating the solution on a suitable support. As the solvent used herein, 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 Ethane, methyl lactate, ethyl lactate,
Examples thereof include, but are not limited to, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyrolactone, and toluene. These solvents are used alone or as a mixture.

As the solvent used for coating, it is preferable to select a solvent having different solubility to the alkali-soluble polymer used for the upper layer and the alkali-soluble polymer used for the lower layer. In other words, when the upper layer is coated next to the lower layer after applying the lower layer, if a solvent capable of dissolving the lower layer alkali-soluble polymer is used as the uppermost layer coating solvent, mixing at the layer interface cannot be ignored, and extreme In such a case, there is a case where a uniform single layer is formed without forming a multilayer. As described above, when mixing occurs at the interface between two adjacent layers, or when the two layers are compatible with each other and behave like a uniform layer, the effect of the present invention due to having two layers may be impaired, which is not preferable. . For this reason, the solvent used for applying the upper layer is preferably a poor solvent for the alkali-soluble polymer contained in the lower layer. When applying each layer, the concentration of the above components (total solids including additives) in the solvent is preferably 1%.
５０50% by weight.

[0078] Further application, upper and lower coating weight on the support obtained after drying (solid content) may be varied depending on the use, the upper layer is 0.05 to 1.0 g / m ^2, the lower layer is 0. It is preferably from ³ to 3.0 g / m ² . If the upper layer is less than 0.05 g / m ^2, the image forming property is lowered, sensitivity exceeds 1.0 g / m ² comes out may be reduced. If the amount of the lower layer is out of the above range, the image forming property tends to be reduced when the amount is too small or too large. In addition, the total of the two layers is 0.5 to
It is preferably 3.0 g / m ² and the coating amount is 0.5 g / m ^2.
If it is less than g / m ² , the film properties will be degraded and 3.0 g / m ²
If it exceeds, the sensitivity tends to decrease. As the amount of coating decreases, the apparent sensitivity increases, but the film properties of the upper and lower layers decrease.

Various methods can be used for the application, such as bar coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, roll coating and the like. Can be. In the upper layer and the lower layer in the present invention, a surfactant for improving coating properties, for example,
A fluorine-based surfactant as described in JP-A-170950 can be added. The preferred amount is
It is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight, based on the total solid content of the lower or upper layer.

[Support] As a support for the lithographic printing plate precursor used in the present invention, a dimensionally stable plate having the necessary strength and durability can be mentioned. Plastic (eg, polyethylene, polypropylene, polystyrene, etc.) laminated paper, metal plate (eg,
Aluminum, zinc, copper, etc.), plastic films (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate)
Polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic film on which a metal as described above is laminated or vapor-deposited.

As the support of the present invention, a polyester film or an aluminum plate is preferable. Among them, an aluminum plate having good dimensional stability and relatively low cost is particularly preferable. Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and containing a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in aluminum alloys include silicon, iron, manganese,
Copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of the foreign element in the alloy is at most 10% by weight or less. Particularly preferred aluminum in the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, particularly preferably 0.2 mm to 0.3 mm.

Prior to roughening the aluminum plate, if necessary, a degreasing treatment with, for example, a surfactant, an organic solvent or an alkaline aqueous solution is performed to remove rolling oil on the surface. The surface roughening treatment of the aluminum plate
The method is performed by various methods, for example, a method of mechanically roughening the surface, a method of electrochemically dissolving and roughening the surface, and a method of chemically selectively dissolving the surface. As a mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used. In addition, as an electrochemical surface roughening method, there is a method of performing an alternating or direct current in a hydrochloric acid or nitric acid electrolyte.
Further, as disclosed in JP-A-54-63902, a method in which both are combined can be used. The aluminum plate thus surface-roughened is subjected to an alkali etching treatment and a neutralization treatment as required, and then subjected to an anodic oxidation treatment, if desired, in order to increase the water retention and abrasion resistance of the surface. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. Generally, sulfuric acid, phosphoric acid,
Oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte.

The anodizing treatment conditions vary depending on the electrolyte used and cannot be specified unconditionally. However, in general, the concentration of the electrolyte is 1 to 80% by weight, the solution temperature is 5 to 70 ° C., and the current density is 5 to 60 A. / Dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 seconds to 5 minutes are appropriate. When the amount of the anodic oxide film is less than 1.0 g / m ² , the printing durability is insufficient or the non-image portion of the lithographic printing plate is easily scratched,
So-called "scratch stains" in which ink adheres to scratches during printing are likely to occur. After the anodizing treatment, the aluminum surface is subjected to a hydrophilic treatment as necessary. U.S. Pat. Nos. 2,7,7
No. 14,066, No. 3,181,461, No. 3,2
There is an alkali metal silicate (e.g., sodium silicate aqueous solution) method as disclosed in U.S. Pat. Nos. 80,734 and 3,902,734. In this method, the support is immersed or electrolytically treated with an aqueous solution of sodium silicate. Further, potassium fluoride zirconate disclosed in JP-B-36-22063 and U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689,272 are disclosed. A method of treating with polyvinyl phosphonic acid as described above is used.

The lithographic printing plate precursor applied to the present invention comprises:
At least two layers, a positive recording layer and a lower layer, are laminated on a support, and an undercoat layer can be provided between the support and the lower layer as needed. As the undercoat layer component, various organic compounds are used, for example, carboxymethyl cellulose, dextrin, gum arabic, phosphonic acids having an amino group such as 2-aminoethylphosphonic acid, and phenylphosphonic acid optionally having a substituent , Organic phosphonic acids such as naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, phenylphosphoric acid which may have a substituent, naphthylphosphoric acid, alkylphosphoric acid and glycerophosphoric acid Organic phosphoric acid, optionally substituted phenylphosphinic acid, naphthylphosphinic acid, organic phosphinic acid such as alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and β-alanine, and hydrochloric acid of triethanolamine Has hydroxy groups such as salts -Alanine, and hydrochlorides of amines that may be used in combination of two or more.

This organic undercoat layer can be provided by the following method. That is, water or methanol, ethanol,
A method in which a solution obtained by dissolving the above organic compound in an organic solvent such as methyl ethyl ketone or a mixed solvent thereof is applied to an aluminum plate and dried, and an organic solvent such as water or methanol, ethanol, methyl ethyl ketone or a mixed solvent thereof is used. In this method, an aluminum plate is immersed in a solution in which the above-mentioned organic compound is dissolved to adsorb the above-mentioned compound, and then washed with water or the like and dried to form an organic undercoat layer. In the former method, a solution of the above organic compound having a concentration of 0.005 to 10% by weight can be applied by various methods. In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 5% by weight.
The immersion temperature is 20 to 90 ° C., preferably 25 to 5 ° C.
0 ° C., and the immersion time is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute. The solution used for this is ammonia,
The pH can be adjusted to a range of 1 to 12 with a basic substance such as triethylamine or potassium hydroxide or an acidic substance such as hydrochloric acid or phosphoric acid. Further, a yellow dye can be added for improving the tone reproducibility of the image recording material. The coating amount of the organic undercoat layer is suitably from ² to 200 mg / m ² , and preferably from 5 to 100 mg / m ² . If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. The same is true even if it is larger than 200 mg / m ² .

The positive type lithographic printing plate precursor prepared as described above is exposed imagewise and then subjected to development processing. Examples of the light source of the actinic ray used for the image exposure include a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, a carbon arc lamp, and the like.
Examples of the radiation include an electron beam, an X-ray, an ion beam, and a far-infrared ray. In addition, g-line, i-line, Deep-UV light, and high-density energy beam (laser beam) are also used. Examples of the laser beam include a helium-neon laser, an argon laser, a krypton laser, a helium-cadmium laser, and a KrF excimer laser. In the present invention, a light source having an emission wavelength in the near infrared to infrared region is preferable, and a solid-state laser and a semiconductor laser are particularly preferable.

As a developer and a replenisher thereof used for developing the lithographic printing plate precursor of the present invention, conventionally known aqueous alkali solutions can be used. For example, sodium silicate, potassium potassium, tribasic sodium phosphate, potassium potassium,
Same ammonium, dibasic sodium phosphate, same potassium,
Inorganic alkali salts such as ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium and lithium Can be Also, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine and pyridine are also used. These alkali agents are used alone or in combination of two or more.

Among these alkali agents, particularly preferred developers are aqueous solutions of silicates such as sodium silicate and potassium silicate. The reason is that the developability can be adjusted by the ratio and concentration of the silicon oxide SiO ₂ and the alkali metal oxide M ₂ O which are the components of the silicate.
JP-A-54-62004, JP-B-57-7427.
An alkali metal silicate as described in the above item is effectively used.

In the case of developing using an automatic developing machine, an aqueous solution having a higher alkali strength than the developing solution (replenisher)
It is known that a large amount of lithographic printing plate precursors can be processed without replacing the developing solution in the developing tank for a long period of time by adding to the developing solution. This replenishment system is also preferably applied in the present invention. Various surfactants and organic solvents can be added to the developing solution and the replenishing solution as needed for the purpose of accelerating or suppressing the developing property, dispersing the developing residue and improving the ink affinity of the printing plate image area. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Further, the developing solution and the replenisher may contain, if necessary, a reducing agent such as a sodium salt or a potassium salt of an inorganic acid such as hydroquinone, resorcinol, sulfurous acid, and bisulfite, and further include an organic carboxylic acid, an antifoaming agent, and a water softener. Can be added. The printing plate developed using the above developer and replenisher is post-treated with washing water, a rinsing solution containing a surfactant and the like, and a desensitizing solution containing gum arabic and a starch derivative. As the post-processing of the lithographic printing plate precursor of the present invention, these processings can be used in various combinations.

In recent years, in the plate making / printing industry, automatic developing machines for printing plates have been widely used in order to rationalize and standardize plate making operations. This automatic developing machine generally includes a developing section and a post-processing section, and includes a device for transporting a printing plate, each processing solution tank and a spray device, and transports the exposed printing plate horizontally while pumping each plate. The developing process is performed by spraying a processing liquid from a spray nozzle. Recently, a method has been known in which a printing plate is immersed and conveyed by a submerged guide roll or the like in a processing liquid tank filled with a processing liquid to perform processing. In such an automatic processing, the processing can be performed while replenishing each processing liquid with a replenisher according to the processing amount, the operating time, and the like. Further, a so-called disposable processing method in which processing is performed with a substantially unused processing liquid can also be applied.

In the lithographic printing plate precursor according to the present invention, image exposure, development, washing and / or rinsing and / or
Alternatively, if there is an unnecessary image portion (for example, a film edge mark of the original film) on the lithographic printing plate obtained by gumming, the unnecessary image portion is erased. Such erasing is performed by applying an erasing liquid as described in, for example, Japanese Patent Publication No. 2-129393 to an unnecessary image portion.
It is preferable to carry out washing by rinsing with water after leaving it for a predetermined period of time, but it is necessary to irradiate an unnecessary image area with an actinic ray guided by an optical fiber as described in JP-A-59-174842, and then develop. A method to do this is also available.

The lithographic printing plate obtained as described above can be subjected to a printing step after applying a desensitized gum if desired. Is subjected to a burning process. When burning a lithographic printing plate, before burning,
No. 2518, No. 55-28062, JP-A-62-3
It is preferable to treat with a surface-regulating liquid as described in JP-A Nos. 1859 and 61-159655. As a method, a sponge or absorbent cotton impregnated with the surface conditioning liquid is applied on a lithographic printing plate, or a method in which the printing plate is immersed in a vat filled with the surface conditioning solution and applied, Application by an automatic coater or the like is applied. Further, it is more preferable to make the application amount uniform with a squeegee or a squeegee roller after the application.

The coating amount of the surface conditioning liquid is generally 0.03 to 0.8.
g / m ² (dry weight) is appropriate. The lithographic printing plate to which the surface conditioning liquid has been applied is dried if necessary, and then burned (for example, a burning processor sold by Fuji Photo Film Co., Ltd .: "BP-130").
0 "). The heating temperature and time in this case depend on the type of the component forming the image,
The temperature is preferably in the range of 180 to 300 ° C for 1 to 20 minutes.

The burned lithographic printing plate can be subjected to conventional treatments such as washing with water and gumming if necessary. When is used, so-called desensitizing treatment such as gumming can be omitted. The lithographic printing plate obtained by such a process is set on an offset printing machine or the like and used for printing a large number of sheets.

[0095]

Hereinafter, the present invention will be described with reference to Examples.
The scope of the present invention is not limited to these examples. [Preparation of Lithographic Printing Plate Precursors 1-16] [Preparation of Substrate] 0.3 mm thick aluminum plate (material
1050) was degreased by washing with trichloroethylene.
After, nylon brush and 400 mesh pumice-water suspension
The surface was grained using a liquid and washed well with water. This
The plate in a 25% aqueous solution of sodium hydroxide at 45 ° C for 9 seconds
Etching by immersion, washing with water, and then 20% nitric acid
For 20 seconds and washed with water. At this time,
Etching amount is about 3g / m ^TwoMet. Next, this plate
% Sulfuric acid as electrolyte and current density 15A / dm^Two3g /
m^TwoAfter providing a direct current anodic oxide coating of
Furthermore, at 30 ° C. with a 2.5% by weight aqueous solution of sodium silicate.
Treat for 10 seconds, apply the following undercoat liquid, and coat the film at 80 ° C.
After drying for 15 seconds, a substrate was obtained. The coating amount of the coating film after drying is 1
5mg / m^TwoMet.

[Undercoat liquid]-The following polymer compound 0.3 g-Methanol 100 g-Water 1 g

[0097]

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[Formation of Recording Layer] The following substrate coating solution was applied to the obtained substrate so as to have a coating amount of 0.85 g / m ^2, and then PERFECT OVEN manufactured by TABAI.
Set the Wind Control to 7 at PH200 and dry at 140 ° C for 50 seconds, then apply the following upper layer coating solution so that the coating amount is 0.15 g / m ^2, and then dry at 120 ° C for 1 minute. Lithographic printing plate precursor 1
17 was obtained.

[Coating Solution for Lower Layer] N- (4-aminosulfonylphenyl) methacrylamide / acrylonitrile / methyl methacrylate (36/34/30: weight average molecular weight 50,000) 2.133 g • 3-methoxy-4-diazo Diphenylamine 0.030 g Hexafluorophosphate • Cyanine dye A (the following structure) 0.109 g • 4,4'-Bizhydroxyphenylsulfone 0.063 g • Tetrahydrophthalic anhydride 0.190 g • p-Toluenesulfonic acid 0.008 g • Ethyl The counter ion of violet was changed to 6-hydroxynaphthalene sulfone 0.05 g ・ Fluorine surfactant (MegaFac F176, manufactured by Dainippon Ink Industries, Ltd.) 0.035 g ・ Methyl ethyl ketone 26.6 g ・ 1 -Methoxy-2-p Lopanol 13.6 g ・ γ-butyrolactone 13.8 g

[0100]

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[Coating Liquid for Upper Layer] 0.237 g of novolak resin described in the following Table 1-0.047 g of cyanine dye A (the above structure)-0.060 g of dodecyl stearate-3-methoxy-4-diazodiphenylamine hexafluoro Phosphate 0.030 g ・ Fluorine-based surfactant (MegaFac F176, manufactured by Dainippon Ink and Chemicals, Inc.) 0.110 g ・ Fluorine-based surfactant [Megafac MCF-312 (30%), Dainippon Ink Industries ( 0.120 g ・ Methyl ethyl ketone 15.1 g ・ 1-methoxy-2-propanol 7.7 g ・ Additives X g shown in Table 1 below

[Evaluation of Lithographic Printing Plate Precursor] For development of the obtained lithographic printing plate precursor, developing solutions DT-1 and DT-1R manufactured by Fuji Photo Film Co., Ltd. were used in a usual manner. A scratch resistance test, sensitivity and ablation evaluation as described below were performed.

[Scratch Resistance Test] The obtained lithographic printing plate precursor was subjected to a rotary ablation tester (TOYO).
(SEIKI) and rubbed 20 times with Abrazelfelt CS5 under a load of 250 g. Thereafter, the film was developed using a PS processor 900H manufactured by Fuji Photo Film Co., Ltd., charged with the above alkali developing solution, at a liquid temperature of 30 ° C. for a developing time of 12 seconds. Observed visually. The evaluation criteria for the scratch resistance were as follows, and the evaluation results are shown in Table 1 below.

：: no change in optical density at all △: scratch marks can be visually discriminated ：: substrate is slightly exposed ×: optical density is about 1/2

[Evaluation of Sensitivity] A test pattern was drawn on the obtained lithographic printing plate precursor in the form of an image by changing the exposure energy with a Trendsetter manufactured by Creo Corporation. Thereafter, a developer DT- manufactured by Fuji Photo Film Co., Ltd.
The developer was developed at 1 (diluted to an electric conductivity of 45 mS / cm), and the exposure energy at which a non-image area could be developed with this developer was measured and defined as sensitivity. The smaller the value, the higher the sensitivity. Table 1 shows the results.

[Evaluation of ablation] The ablation was carried out with a polyethylene terephthalate film (0.10 mm, manufactured by FUJIFILM Corporation) in close contact with each of the printing master plates, using a Trendsetter manufactured by Creo Inc. at a drum rotation speed of 100 rp.
The polyethylene terephthalate film was removed, and the amount of the transferred ablation debris was visually evaluated by exposing at m and a beam intensity of 8.0 W. The evaluation criteria for ablation were as follows, and the evaluation results are shown in Table 1 below.

A: No abrasion scum is observed from the polyethylene terephthalate film. Δ: Ablation scum is slightly observed from the polyethylene terephthalate film. X: Ablation scum is observed from the polyethylene terephthalate film.

[0108]

[Table 1]

Novolak structure Novolak 1: 2,3-xylenol / m-cresol / p-cresol / phenol = 35/30/30/5 (Mw68
Novolak 2: 2,5-xylenol / m-cresol / p-cresol / phenol = 35/30/30/5 (Mw52)
Novolak 3: 3,5-xylenol / m-cresol / p-cresol / phenol = 35/30/30/5 (Mw75)
Novolak 4: 2,3-xylenol / m-cresol / p-cresol / phenol = 45/5/5/45 (Mw80)
Novolak 5: 2,5-xylenol / phenol = 40
/ 60 (Mw5500, content of compounds less than trimer: 19%)

Novolak 6: 3,5-xylenol / m
-Cresol / p-cresol = 30/35/35 (Mw6300,
Novolak 7: 2,3-xylenol / m-cresol / p-cresol / phenol = 35/50/10/5 (Mw45)
Novolak 8: 2,3-xylenol / m-cresol / phenol = 35/55/10 (Mw2800, content of compound less than trimer 25%) Novolak 9: m-cresol / p-cresol = 60 /
Novolak 10: 2,3-xylenol / m-cresol / p-cresol / phenol = 35/30/30/5 (Mw6000
3500, the content of the trimer and lower compounds is 35%)

[0111] The content of the trimer compound or less is determined by gel permeation chromatography (GP, manufactured by Tosoh Corporation).
C) Using "HLC-8020", using two 30 cm columns of "TSKgelGMHXL-N" manufactured by Tosoh Corporation as a column, using UV as a detector, tetrahydrofuran (special grade) as a mobile phase, an injection amount of 100 µl, and a flow rate of 1.0 ml / The molecular weight was measured under the conditions of minutes and separately calibrated using standard polystyrene, and the content of a compound having a molecular weight of 300 or less was defined as the content of a compound having a molecular weight of trimer or less.

From Table 1 above, it can be seen that the lithographic printing plate precursor of the present invention has excellent scratch resistance, good sensitivity, and hardly causes ablation. On the other hand, the recording layer containing no novolak resin containing the xylenol constituent unit (master 9) had low scratch resistance.

[0113]

The lithographic printing plate precursor according to the present invention has a lower layer containing an alkali-soluble resin and an upper layer containing an alkali-soluble novolak resin containing in its constituent units an infrared absorber and xylenol. By setting the content of the trimer or less compound to 30% or less based on the novolak resin, all of the scratch resistance, sensitivity, and ablation resistance could be improved.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Akio Oda 4000F, Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Pref. BA11 EA04 EA23 GA08 KA03 KA06

Claims (5)

[Claims] 1. A multilayer lithographic plate comprising an alkali-soluble resin-containing layer provided on a support, and a positive-type recording layer containing an infrared absorber and having increased solubility in an alkaline aqueous solution upon exposure to infrared laser. In the printing plate precursor,
A lithographic printing plate precursor, wherein the positive recording layer contains an alkali-soluble novolak resin containing xylenol as a constituent unit. 2. The lithographic printing plate precursor according to claim 1, wherein the content of the trimer or less compound in the positive recording layer is 30% or less based on the novolak resin. 3. The lithographic printing plate precursor according to claim 1, wherein the alkali-soluble resin-containing layer contains an onium salt. 4. The lithographic printing plate precursor according to claim 1, wherein the alkali-soluble resin-containing layer contains an infrared absorber. 5. An alkali-soluble resin-containing layer is provided on a support, and an infrared-absorbing agent and an alkali-soluble novolak resin containing xylenol as a constituent unit are provided thereon. The lithographic printing plate precursor, characterized in that, after imagewise exposing a multilayer type lithographic printing plate precursor provided with an increasing positive recording layer, it is developed with an alkaline developing solution containing a pH buffering organic compound and a base. How to process the original.