JP2002196507A - Method for producing planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a planographic printing plate using an alkali developing solution of a relatively low pH favorable to the environment and safety, stably giving a non-image area having good developability and free of stain in printing and ensuring little damage to an image area in development, high image strength and stably high printing resistance. SOLUTION: A photosensitive planographic printing plate having a photosensitive layer comprising a photopolymerizable photosensitive composition containing a compound having a nitrogen atom and an ethylenically unsaturated double bond, a photopolymerization initiator and a polymer binder on an aluminum base is imagewise exposed and developed with a developing solution containing (1) an inorganic alkali agent and (2) a nonionic surfactant having a polyoxyalkylene ether group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for making a lithographic printing plate. More specifically, a lithographic plate capable of producing a printing plate free from printing stains and having excellent printing durability, improving the safety of a developing solution, stability over time on developing characteristics, and improving the effect of a waste solution on the environment. The present invention relates to a printing plate making method.

[0002]

2. Description of the Related Art Negative-working photosensitive lithographic printing plates, which have been widely used in the past, have a diazo resin provided on a hydrophilically treated aluminum plate. Inevitably, there is a concern about the treatment of the development waste liquid and its effect on the environment. In the photosensitive layer of the positive photosensitive lithographic printing plate, an orthoquinonediazide compound is used in combination with a novolak resin, and an alkaline silicate aqueous solution capable of dissolving the novolak resin is used as a developer. However, the pH at which the novolak resin can be dissolved is about 13, and such a high pH developer is highly irritating when it adheres to skin and mucous membranes, and requires sufficient care in handling.

On the other hand, conventionally, on an aluminum plate support,
Printing with a photosensitive layer of a photopolymerizable photosensitive lithographic printing plate on the surface
Examples of the plate developer include alkali metal silicates, phosphates,
Water-soluble such as carbonates, hydroxides, and organic amine compounds
Liquids have been proposed. For example, Japanese Unexamined Patent Application Publication No.
In the official gazette, at a high pH of 12 or more, alkali silicate and amphoteric
A developer containing a surfactant is disclosed in JP-A-11-65129.
According to the report, SiO _Two/ M_TwoO (M is an alkali metal) is specified
Developer containing alkaline silicate with a pH of 12 or less
It is shown. The former is not only a matter of handling, but also
Is easily damaged by development due to the high pH of the developer
In the latter case, the pH of the developer slightly decreases during use,
There was a problem that the silicate gelled and became insoluble.

Japanese Patent Application Laid-Open No. 61-109052 discloses a developer containing no alkali silicate, a developer comprising an alkali reagent, a complexing agent, an anionic surfactant, an emulsifier, an n-alkanoic acid, and the like. No. 1984605
No. 4,878,098 discloses a developer containing an alkali agent, a complexing agent, an anionic surfactant, amyl alcohol, and N-alkoxyamines.
There was a problem in that the image portion was greatly damaged and sufficient printing performance such as printing durability was obtained.

A developer having a relatively low pH (pH 12 or less) and containing no alkali silicate is disclosed in JP-A-2000-817.
No. 11 discloses a potassium hydroxide aqueous solution containing an anionic surfactant, and JP-A No. 11-65126 discloses a pH of 8.5 to 8.5.
An alkali metal carbonate aqueous solution of 11.5 is disclosed. Problems of development at such a relatively low pH include:
Basically, the photopolymerizable photosensitive layer has a low dissolving power, and thus, for example, there is a problem that the development does not proceed sufficiently with an aged plate material and a residual film is formed. In order to solve these problems, it is necessary to increase the acid value of the polymer binder in the plate photosensitive layer to increase developability, or to use a combination of monomers having an acid group. When a high acid value binder was used, printing problems such as a problem that ink did not adhere during printing (blinding) were likely to occur.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned conventional problems, that is, to use a relatively low pH alkaline developing solution which is preferable from the viewpoint of environment and safety, and to stably use the developing solution. , The non-image area has good developability, there is no stain in printing, and the image area has strong image strength with little damage in development, and more specifically, stable high printing durability. An object of the present invention is to provide a method of making a lithographic printing plate capable of realizing the lithographic printing plate.

[0007]

Means for Solving the Problems The inventor of the present invention has conducted intensive studies to achieve the above object, and as a result,
By using a developer containing a nonionic surfactant having a specific structure, the dissolution rate of the unexposed portion of the photopolymerizable photosensitive layer increases, and conversely, the crosslinked portion of the exposed portion by photopolymerization becomes It has been found that penetration is suppressed. Further, when the monomer component of the photosensitive layer component is urethane acrylate or N-
In the case of a compound having a nitrogen atom and an ethylenically unsaturated double bond in the molecule, such as a substituted acrylamide, particularly, the above-mentioned effects are remarkable, and it has been found that a lithographic printing plate having extremely high printing durability is obtained. Reached. That is, the present invention is as follows. (1) A photosensitive layer comprising a photopolymerizable photosensitive composition containing a compound having a nitrogen atom and an ethylenically unsaturated double bond, a photopolymerization initiator, and a polymer binder is formed on an aluminum support. Lithographic printing plate having a photosensitive lithographic printing plate having, after image exposure, a developing solution containing 1) an inorganic alkali agent and 2) a nonionic surfactant having a polyoxyalkylene ether group. How to make a printing plate.

According to the method of making a lithographic printing plate of the present invention,
Deterioration of the developing characteristics due to the aging or repeated use of the developer is suppressed, and good developability for non-image areas is obtained, there is no stain in printing, and image areas are less damaged in development and are strong. High image intensity can be obtained. Furthermore, according to the method for making a lithographic printing plate of the present invention, it is possible to produce a printing plate free from printing stains and excellent in printing durability, and because the pH of a developer is relatively low, it is safe and preferable. It is possible to improve the effect of liquid waste on the environment.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The method of making a lithographic printing plate according to the present invention will be described in detail below. First, the features of the method for making a lithographic printing plate of the present invention will be described, and a novel developing solution used in the plate making method of the present invention will be described. The developer of the present invention is an alkaline aqueous solution containing at least (1) an inorganic alkali agent and (2) a nonionic surfactant having a polyoxyalkylene ether group.

Examples of (1) the inorganic alkali agent of the present invention include, for example, sodium tertiary phosphate, potassium tertiary ammonium, sodium carbonate, potassium tertiary ammonium, sodium bicarbonate, potassium tertiary, ammonium tertiary, boric acid Sodium, potassium, ammonium, sodium hydroxide, potassium, ammonium, lithium and the like. Further, an organic alkali agent may be supplementarily used for the purpose of finely adjusting the alkali concentration and assisting the solubility of the photosensitive layer. Examples of the organic alkaline agent include monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, Examples thereof include diisopropanolamine, ethyleneimine, ethylenediamine, pyridine, and tetramethylammonium hydroxide.

These alkaline agents are used alone or in combination of two or more. As the amount of the alkali agent, the pH of the developer is in the range of 9 to 13.5, and the conductivity is 2 to 2.
It is used so as to be in a range of 40 mS / cm, and preferable ranges are pH 10.0 to 12.5 and conductivity 3 to 30.
mS / cm range, more preferably 5-20 mS / cm
Range. If the pH of the developing solution falls below the above range, image formation becomes impossible, and if the pH exceeds the above range, over-development occurs or damage in the development of the exposed portion increases. When the electric conductivity is lower than the above range, the elution of the photosensitive composition on the surface of the aluminum plate support is usually difficult, and the printing is contaminated. If the concentration exceeds the above range, the salt concentration is high, so that the elution rate of the photosensitive layer becomes extremely slow, and a residual film is formed in an unexposed portion.

It is essential that the developer of the present invention contains (2) a nonionic surfactant having a polyoxyalkylene ether group, and the addition of this surfactant dissolves the photosensitive layer in the unexposed area. This makes it possible to reduce the permeability of the developer to the exposed portion. As the surfactant containing a polyoxyalkylene ether group, those having the structure of the following general formula (I) are preferably used.

R ¹ -O- (R ² -O) _n H (I)

In the formula (I), R ¹ represents an alkyl group having 3 to 15 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 15 carbon atoms which may have a substituent, or A heteroaromatic ring group having 4 to 15 carbon atoms which may have a substituent (an alkyl group having 1 to 20 carbon atoms, a halogen atom such as Br, Cl, I, etc .; Aromatic hydrocarbon group,
Examples thereof include an aralkyl group having 7 to 17 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkoxy-carbonyl group having 2 to 20 carbon atoms, and an acyl group having 2 to 15 carbon atoms. And R ² is an alkylene group having 1 to 100 carbon atoms which may have a substituent (as the substituent, an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 15 carbon atoms) And n represents an integer of 1 to 100.

In the formula (I), the portion of (R ² -O) _n may be two or three groups within the above range. Specifically, a random or block-like combination of a combination of an ethyleneoxy group and a propyleneoxy group, a combination of an ethyleneoxy group and an isopropyleneoxy group, a combination of an ethyleneoxy group and a butyleneoxy group, and a combination of an ethyleneoxy group and an isobutyleneoxy group. Can be In the present invention, the surfactant having a polyoxyalkylene ether group is used alone or in a complex system,
It is effective to add 0% by weight, preferably 2 to 20% by weight. If the addition amount is small, the developing property is reduced, while if it is too large, the damage of development is increased, and the printing durability of the printing plate is reduced.

Further, other surfactants described below may be added. As other surfactants, for example, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether and the like Polyoxyethylene alkyl allyl ethers, polyoxyethylene alkyl esters such as polyoxyethylene stearate, sorbitan monolaurate, sorbitan monostearate, sorbitan distearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan triole Sorbitan alkyl esters such as ate,
Nonionic surfactants such as monoglyceride alkyl esters such as glycerol monostearate and glycerol monooleate: alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, sodium butylnaphthalenesulfonate, sodium pentylnaphthalenesulfonate, sodium hexylnaphthalenesulfonate Anionic surface activity such as alkyl naphthalene sulfonates such as sodium octyl naphthalene sulfonate, alkyl sulfates such as sodium lauryl sulfate, alkyl sulfonates such as sodium dodecyl sulfonate, sulfosuccinate salts such as sodium dilauryl sulfosuccinate; Agents: Alkyl betaines such as lauryl betaine and stearyl betaine, and amphoteric surfactants such as amino acids can be used. But particularly preferred are anionic surfactants such as alkyl naphthalene sulfonic acid salts.
These surfactants can be used alone or in combination. The content of these surfactants in the developer is 0.1 to 0.1 in terms of active ingredient (solid content).
20% by weight is preferred.

In the developer of the present invention, the following components may be used in combination with the above components, if necessary. For example, benzoic acid, phthalic acid, p-ethylbenzoic acid, pn
-Propylbenzoic acid, p-isopropylbenzoic acid, p-
n-butylbenzoic acid, pt-butylbenzoic acid, p-2
-Hydroxyethylbenzoic acid, decanoic acid, salicylic acid,
Organic carboxylic acids such as 3-hydroxy-2-naphthoic acid;
Isopropyl alcohol, hensyl alcohol, ethyl cellosolve, butyl cellosolve, phenyl cellosolve,
Organic solvents such as propylene glycol and diacetone alcohol; and other examples include chelating agents, reducing agents, dyes, pigments, water softeners, preservatives, and defoamers.

Next, the photosensitive lithographic printing plate used in the present invention will be described. The photopolymerizable photosensitive composition constituting the photosensitive layer of the photosensitive lithographic printing plate used in the present invention includes a compound having a nitrogen atom and an ethylenically unsaturated double bond, a photopolymerization initiator (hereinafter, simply referred to as a photoinitiator). ), A polymer binder as an essential component, and, if necessary, various compounds such as a coloring agent, a plasticizer, and a thermal polymerization inhibitor.

The term "ethylenically unsaturated compound" means an ethylenically unsaturated bond which, when a photopolymerizable photosensitive composition is irradiated with actinic rays, undergoes addition polymerization by the action of a photopolymerization initiator to cause crosslinking and curing. In the present invention, a compound having a nitrogen atom in the molecule is used. The compound containing an addition-polymerizable ethylenic double bond can be arbitrarily selected from compounds having at least one, and preferably two or more, terminal ethylenically unsaturated bonds. For example, those having a chemical form such as a monomer, a prepolymer, that is, a dimer, a trimer and an oligomer, or a mixture thereof and a copolymer thereof.

Examples of the ethylenically unsaturated compound having a nitrogen atom include amides of unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.). An amide of an unsaturated carboxylic acid and an aliphatic polyamine compound is used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxyl group, an amino group or a mercapto group with a monofunctional or polyfunctional isocyanate is also preferably used. Also, having an isocyanate group, an unsaturated carboxylic acid ester, an addition reaction product of an amide with a monofunctional or polyfunctional alcohol, an amine, or a thiol, or a leaving substituent such as a halogen group or a tosyloxy group. Substitution products with monofunctional or polyfunctional amines are also suitable. It is also possible to use a group of compounds in which unsaturated phosphonic acid, styrene, vinyl ether or the like is substituted for the above unsaturated carboxylic acid.

A particularly preferred addition-polymerizable compound having at least one ethylenically unsaturated double bond is a urethane-based addition-polymerizable compound produced by an addition reaction between an isocyanate and a hydroxyl group.

As a specific example, for example, a polyisocyanate compound having two or more isocyanate groups in one molecule described in JP-B-48-41708 is represented by the following general formula (2). And a vinyl urethane compound containing two or more polymerizable vinyl groups in one molecule to which a hydroxyl group-containing vinyl monomer is added. CH ₂ ＣC (R) COOCH ₂ CH (R ′) OH (2) (where R and R ′ represent H or CH ₃ )

Also, urethane (meth) acrylates described in JP-A-51-37193, JP-B-2-32293 and JP-B-2-16765, and JP-B-58-49860 and JP-B-58-49860. Examples thereof include urethane compounds having an ethylene oxide skeleton described in JP-B-56-17654, JP-B-62-39417, and JP-B-62-39418. Particularly preferred specific examples include the following compounds. It is a reaction product of a polyisocyanate compound of group (1) and an alcohol compound of group (2).

[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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More specifically, the following compounds correspond to them. Urethane acrylate M- manufactured by Toa Gosei Co., Ltd.
1100, M-1200, M-1210, M-130
0, urethane acrylate EB210, EB4827, EB6700, EB manufactured by Daicel UCB Co., Ltd.
220, UVITHANE-782, UVIT manufactured by MORTON THIOKOL Inc
HANE-783, UVITHANE-788, UVITHANE-893,
Art resin UN-9000EP manufactured by Negami Industry Co., Ltd.
Art Resin UN-9200A, Art Resin UN-9
00H, Art Resin UN-1255, Art Resin U
N-5000, Art Resin UN-2111A, Art Resin UN-2500, Art Resin UN-3320H
A, Art Resin UN-3320HB, Art Resin U
N-3320HC, Art Resin UN-3320HS,
Art Resin UN-6060P, Art Resin UN-6
060PTM, Art Resin SH-380G, Art Resin SH-500, Art Resin SH-9832, NK Oligo U-4H, NK Oligo U- manufactured by Shin-Nakamura Chemical Co., Ltd.
4HA, NK oligo U-4P, NK oligo U-4PA,
NK Oligo U-4TX, NX Oligo U-4TXA, NE
Oligo U-6LHA, NK Oligo U-6LPA-N, N
K oligo U-6LTXA, NK oligo UA-6ELP,
NK oligo UA-6ELH, NK oligo UA-6ELT
X, NK oligo UA-6PLP, NK oligo U-6EL
P, NK Oligo U-6ELH, NK Oligo U-8MD
A, NK Oligo U-8MD, NK Oligo U-12LM
A, NK oligo U-12LM, NK oligo U-6HA,
NK oligo U-108A, NK oligo U-1084A,
NK oligo U-200AX, NK oligo U-122A,
NK oligo U-340A, NK oligo U-324A, N
K-oligo UA-100, AH-6 manufactured by Kyoeisha Chemical Co., Ltd.
00, AT-600, UA-306H, AI-600,
UA-101T, UA-101I, UA-101H, U
A-306T, UA-306I, UF-8001, UF
-8003 and the like.

Specific examples of the amide monomer of the aliphatic polyamine compound and the unsaturated carboxylic acid include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6- Hexamethylene bis-methacrylamide,
Examples include diethylenetriaminetrisacrylamide, xylylenebisacrylamide, xylylenebismethacrylamide, and the like.

Examples of other preferred amide monomers include those having a cyclohexylene structure described in JP-B-54-21726.

The ethylenically unsaturated compound containing a nitrogen atom used in the present invention includes West German Patent A2064079.
The reaction products of monoisocyanates or diisocyanates and partial esters of polyhydric alcohols described in JP-A Nos. 2,610,41 and 2,822,190 are also advantageously used. In the molecular structure, a thio group, a ureido group, an amino group, a urethane group which may be a member of a heterocyclic ring, specifically, a triethanolamino group, a triphenylamino group,
Unsaturated compounds containing a photo-oxidizable group such as a thiourea group, an imidazole group, an oxazole group, a thiazole group, N-phenylglycine and an ascorbic acid group are also preferably used. Examples of such compounds include EP-A-287.
Nos. 818, 353389, and 384,735. Preferred among the compounds described therein are those containing a tertiary amino group, a ureido group and a urethane group. These unsaturated compounds containing a nitrogen atom can be used alone or in combination, and can be mixed with known unsaturated compounds such as monomers of esters of polyhydric alcohols and unsaturated carboxylic acids described below. It doesn't matter.

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

Examples of the methacrylate include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol. Dimethacrylate, hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol pentamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate , Bis [p- (3--methacryloxy-2-hydroxypropoxy) phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

Examples of itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
There are 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, sorbitol tetritaconate and the like. Crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, sorbitol tetracrotonate and the like. Examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of the maleic acid ester include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate. Polyester acrylates described in JP-A-48-64183, JP-B-49-43191 and JP-B-52-30490, epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid, etc. And polyfunctional acrylates and methacrylates. In addition, the Journal of the Adhesion Society of Japan Vol. 20, No. 7, pages 300 to 308 (198
(4 years) as photocurable monomers and oligomers can also be used. The amount of these ethylenically unsaturated compounds used is 5% of the total components of the photosensitive layer.
To 80% by weight, preferably 30 to 70% by weight.

As the photopolymerization initiator to be contained in the photosensitive layer of the photosensitive lithographic printing plate of the present invention, various photoinitiators known in patents and literatures, or two or more photoinitiators may be used depending on the wavelength of the light source used. The photoinitiator combination system (photoinitiation system) can be appropriately selected and used. Specific examples are listed below, but the present invention is not limited thereto. Various light-initiating systems have also been proposed when using visible light of 400 nm or more, an Ar laser, the second harmonic of a semiconductor laser, or an SHG-YAG laser as a light source. For example, US Pat. No. 2,850,445. Certain photoreducing dyes described in
For example, Rose Bengal, Eosin, Erythrosin, etc.
Alternatively, a system based on a combination of a dye and an initiator, for example, a complex initiation system of a dye and an amine (JP-B-44-2018)
No. 9), a combination system of hexaarylbiimidazole, a radical generator and a dye (Japanese Patent Publication No. 45-37377), and a system of hexaarylbiimidazole and p-dialkylaminobenzylidene ketone (Japanese Patent Publication No. 47-2528; 54-155292), a system of a cyclic cis-α-dicarbonyl compound and a dye (JP-A-48-84183), a system of a cyclic triazine and a merocyanine dye (JP-A-54-1).
No. 51024), a system of 3-ketocoumarin and an activator (JP-A-52-112681, JP-A-58-15503).
No.), a system of biimidazole, a styrene derivative, and a thiol (JP-A-59-140203), and a system of an organic peroxide and a dye (JP-A-59-1504, JP-A-59-1402).
03, JP-A-59-189340, JP-A-62-1
No. 74203, JP-B-62-1641, U.S. Pat.
No. 766055), a system of a dye and an active halogen compound (JP-A-63-258903, JP-A-2-63054, etc.) A system of a dye and a borate compound (JP-A-62-1430)
No. 44, JP-A-62-150242, JP-A-64-1
No. 3140, JP-A-64-13141, JP-A-64-141
No. 13142, JP-A-64-13143, JP-A-64
-13144, JP-A-64-17048, JP-A-1
JP-A-229003, JP-A-1-298348, JP-A-1-138204, etc.) A system of a dye having a rhodanine ring and a radical generator (JP-A-2-179634, JP-A-2-244050), titanocene and 3- Ketocoumarin dye systems (JP-A-63-221110), systems in which titanocene and xanthene dyes are combined with an addition-polymerizable ethylenically unsaturated compound containing an amino group or a urethane group (JP-A-4-221958, JP-A-4-221958) -21
No. 9756), a system of titanocene and a specific merocyanine dye (JP-A-6-295061), a system of titanocene and a dye having a benzopyran ring (JP-A-8-334897).
No.) and the like.

Further, a laser (violet laser) having a wavelength of 400 to 410 nm has recently been developed, and a photoinitiating system exhibiting high sensitivity to a wavelength of 450 nm or less has been developed, and these photoinitiating systems have also been used. You. For example, a cationic dye / borate system (JP-A-11-8864)
7), merocyanine dye / titanocene system (JP-A-2000
-147763), carbazole type dye / titanocene (Japanese Patent Application No. 11-22480), and the like. In the present invention, a system using a titanocene compound is particularly preferable because of its excellent sensitivity.

As the titanocene compound, various compounds can be used. For example, JP-A-59-1523
No. 96, and various titanocene compounds described in JP-A-61-151197 can be appropriately selected and used. More specifically, di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-
Ti-bis-2,3,4,5,6-pentafluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophenyl-1-yl,
Di-cyclopentadienyl-Ti-bis-2,4,6-
Trifluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2,6-di-fluorophenyl-1-
Yl, di-cyclopentadienyl-Ti-bis-2,4
-Di-fluorophenyl-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophenyl-1-yl, di-methylcyclopentadienyl-Ti- Bis-2,6-difluorophenyl-1
-Yl, di-cyclopentadienyl-Ti-bis-2,
6-difluoro-3- (pyr-1-yl) -phenyl-1
-Yl and the like. Further, if necessary for the photoinitiator, thiol compounds such as 2-mercaptobenzthiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, N-phenylglycine,
It is known that the photoinitiating ability can be further enhanced by adding a hydrogen-donating compound such as an amine compound such as N, N-dialkylamino aromatic alkyl ester. These photopolymerization initiators (systems) are used in an amount of 0.05 to 100 parts by weight, preferably 0.1 to 70 parts by weight, more preferably 0.2 to 100 parts by weight based on 100 parts by weight of the ethylenically unsaturated compound.
Used in the range of 50 parts by weight.

The polymer binder used in the photosensitive layer of the photosensitive lithographic printing plate of the present invention is not only used as a film-forming agent of the composition but also needs to be dissolved in an alkali developing solution. Organic polymers that are soluble or swellable are used. Examples of such organic high-molecular polymers include addition polymers having a carboxylic acid group in the side chain, such as JP-A-59-44615 and JP-B-54-34327.
No., JP-B-58-12577, JP-B-54-2595
7, JP-A-54-92723, JP-A-59-538.
No. 36, JP-A-59-71048, namely, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, crotonic acid copolymer, maleic acid copolymer, There are esterified maleic acid copolymers and the like.

Similarly, there are acidic cellulose derivatives having a carboxylic acid group in the side chain. In addition, those obtained by adding a cyclic acid anhydride to an addition polymer having a hydroxyl group are useful. In particular, among these, [benzyl (meth) acrylate / (meth) acrylic acid / optionally other addition-polymerizable vinyl monomers] copolymer and [allyl (meth) acrylate (meth) acrylic acid / optionally Other addition-polymerizable vinyl monomers] copolymers are preferred. In addition, polyvinyl pyrrolidone and polyethylene oxide are useful as the water-soluble organic polymer. In order to increase the strength of the cured film, alcohol-soluble polyamides and polyethers of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin are also useful.
In addition, Japanese Patent Publication No. 7-120040, Japanese Patent Publication No. 7-12004
No. 1, Tokiko 7-120042, Tokiko 8-1242
4, JP-A-63-287944, JP-A-63-28944
No. 7947, JP-A-1-271741, JP-A-11-
The polyurethane resin described in 352691 is also useful for the use of the present invention.

These polymers can improve the strength of a cured film by introducing a radical reactive group into a side chain. Functional groups capable of undergoing an addition polymerization reaction include an ethylenically unsaturated bond group, an amino group, an epoxy group, and the like, and functional groups capable of forming a radical upon irradiation with light include a mercapto group, a thiol group, a halogen atom, a triazine structure, and an onium salt structure. And a polar group such as a carboxyl group or an imide group. As the functional group capable of undergoing the addition polymerization reaction, an ethylenically unsaturated bond group such as an acryl group, a methacryl group, an allyl group, and a styryl group is particularly preferable, and an amino group, a hydroxy group, a phosphonic acid group, a phosphoric acid group, a carbamoyl group And a functional group selected from an isocyanate group, a ureido group, a ureylene group, a sulfonic acid group, and an ammonium group are also useful.

In order to maintain the developability of the composition, the polymer binder of the present invention preferably has an appropriate molecular weight and acid value, and has a weight average molecular weight of 5,000 to 300,000 and an acid value of 2,000.
A high polymer of 0 to 200 is effectively used. These organic high-molecular polymers can be mixed in an arbitrary amount in the entire composition. However, if it exceeds 90% by weight, no favorable result is obtained in view of the strength of the formed image and the like. Preferably it is 10-90%, more preferably 30-80%. Further, the weight ratio of the photopolymerizable ethylenically unsaturated compound and the organic polymer is preferably in the range of 1/9 to 9/1. A more preferred range is 2/8 to 8/2, and a still more preferred range is 3/7 to 7/3.

In the present invention, in addition to the above basic components, a small amount of thermal polymerization is prohibited in order to prevent unnecessary thermal polymerization of a polymerizable ethylenically unsaturated compound during the production or storage of the photosensitive composition. It is desirable to add an agent. Suitable thermal polymerization inhibitors include haloid quinone, p-
Methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4-methyl −
6-t-butylphenol), cerium N-nitrosophenylhydroxylamine, aluminum aluminum N-nitrosophenylhydroxylamine and the like.
The addition amount of the thermal polymerization inhibitor is preferably about 0.01% to about 5% based on the solid content of the photosensitive layer. If necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide may be added to prevent polymerization inhibition by oxygen, and may be unevenly distributed on the surface of the photosensitive layer in a drying process after coating. . The amount of the higher fatty acid derivative is preferably about 0.5% to about 10% based on the solid content of the photosensitive layer.

Further, a coloring agent may be added for the purpose of coloring the photosensitive layer. Examples of the colorant include phthalocyanine pigments (CI Pigment Blue 1).
5: 3, 15: 4, 15: 6), azo pigments, pigments such as carbon black and titanium oxide, ethyl violet, crystal violet, azo dyes, anthraquinone dyes, and cyanine dyes. The amount of dye and pigment added is preferably about 0.5% to about 20% of the total composition.
In addition, additives such as inorganic fillers and plasticizers such as dioctyl phthalate, dimethyl phthalate and tricresyl phosphate may be added to improve the physical properties of the cured film. The amount of these additives is preferably 10% or less of the total composition.

When the photosensitive layer composition of the photosensitive lithographic printing plate of the present invention is coated on a support described later, it is used after dissolving it in various organic solvents. As the solvent used here,
Acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran,
Toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol Monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-
Methoxypropanol, methoxymethoxyethanol,
Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate-3-methoxypropyl acetate, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, lactic acid Examples include methyl and ethyl lactate. These solvents can be used alone or as a mixture. The concentration of the solid content in the coating solution is suitably from 1 to 50% by weight.

A surfactant can be added to the photopolymerizable composition in the photosensitive layer of the photosensitive lithographic printing plate of the present invention in order to improve the coated surface quality. The coverage of the photosensitive layer is suitably ranges from about 0.1 g / m ² ~ about 10 g / m ² in weight after drying. More preferably, it is 0.3 to 5 g / m ² .
More preferably, it is 0.5 to 3 g / m ² .

Usually, an oxygen-blocking protective layer (overcoat layer) is provided on the photosensitive layer in order to prevent the action of inhibiting polymerization of oxygen. Examples of the water-soluble vinyl polymer contained in the oxygen-blocking protective layer include polyvinyl alcohol, and its partial esters, ethers, and acetal, or a substantial amount of unsubstituted vinyl alcohol units that have the necessary water solubility. (Polyvinyl acetal). As polyvinyl alcohol, the degree of saponification is 71 to 100 mol%
Wherein the degree of polymerization is in the range of 300 to 2400. Specifically, Kuraray's PVA-105,
PVA-110, PVA-117, PVA-117H,
PVA-120, PVA-124, PVA-124H,
PVA-CS, PVA-CST, PVA-HC, PVA
-203, PVA-204, PVA-205, PVA-
210, PVA-217, PVA-220, PVA-2
24, PVA-217EE, PVA-217E, PVA
-220E, PVA-224E, PVA-405, PV
A-420, PVA-613, L-8 and the like.
The above copolymer has a degree of saponification of 88 to 100 mol%.
And polyvinyl acetate chloroacetate or propionate, polyvinyl formal and polyvinyl acetal, and copolymers thereof. Other useful polymers include polyvinylpyrrolidone, gelatin and gum arabic, which may be used alone or in combination.

The solvent used for coating the oxygen-barrier protective layer in the photosensitive lithographic printing plate of the present invention is preferably pure water, but alcohols such as methanol and ethanol, and ketones such as acetone and methyl ethyl ketone are purified with pure water. May be mixed. The concentration of the solid content in the coating solution is suitably from 1 to 20% by weight. Known additives such as a surfactant for improving coating properties and a water-soluble plasticizer for improving physical properties of the film may be added to the oxygen-barrier protective layer of the present invention. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, and sorbitol. Further, a water-soluble (meth) acrylic polymer or the like may be added. Its garment weight of about by weight of dry 0.1 g / m ² ~ about 15 g / m ²
Is appropriate. More preferably, 1.0 g / m ² or more
It is about 5.0 g / m ² .

Next, the support of the photosensitive lithographic printing plate of the present invention will be described. The aluminum support used in the present invention is a dimensionally stable aluminum or an alloy thereof (eg, silicon, copper, manganese, magnesium, chromium,
Alloy with zinc, lead, bismuth, nickel), or a plastic film or paper on which aluminum or an aluminum alloy is laminated or vapor-deposited, and usually has a thickness of about 0.05 mm to 1 mm. Also, a composite sheet described in JP-A-48-18327 can be used.

The aluminum support of the present invention is appropriately subjected to a substrate surface treatment described later. (Graining treatment) Japanese Patent Application Laid-Open No. Sho 56-2
No. 8993, such as mechanical graining, chemical etching, electrolytic grains, and the like. Furthermore, an electrochemical graining method in which the aluminum surface is electrochemically grained in a hydrochloric acid or nitric acid electrolyte, a wire brush graining method in which the aluminum surface is scratched with a metal wire, and a ball graining method in which the aluminum surface is grained with a polishing ball and an abrasive. Alternatively, a mechanical graining method such as a brush grain method for graining the surface with a nylon brush and an abrasive can be used, and the above graining methods can be used alone or in combination. Among them, a method of producing a surface roughness usefully used in the present invention is an electrochemical method of chemically sanding in a hydrochloric acid or nitric acid electrolyte, and a suitable current density is 100 C / dm ^{2 to} 400 C. / Dm ² . More specifically, in an electrolytic solution containing 0.1 to 50% hydrochloric acid or nitric acid, the temperature is 20 to 100 ° C., and the time is 1 second to 3 hours.
0 minutes, it is preferable to perform the electrolysis at a current density of ^{100C / dm 2 ~400C / dm 2} .

The aluminum support thus grained is chemically etched with an acid or an alkali. When an acid is used as an etching agent, it takes time to destroy a fine structure, which is disadvantageous in industrially applying the present invention. However, it can be improved by using an alkali as an etching agent. Alkali agents suitably used in the present invention include caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide, and the like. The preferred ranges of concentration and temperature are 1 to 50, respectively. %, 20 to 10
It is preferable that the temperature is 0 ° C. and the amount of Al dissolved is 5 to 20 g / m ³ . After etching, pickling is performed to remove dirt (smut) remaining on the surface.
As the acid used, nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, borofluoric acid and the like are used. In particular, as a method of removing the smut after the electrochemical surface-roughening treatment, a method of contacting with 15 to 65% by weight of sulfuric acid at a temperature of 50 to 90 ° C as described in JP-A-53-12739 is preferred. And an alkali etching method described in JP-B-48-28123.
The surface roughness (Ra) of the Al support effectively used in the present invention is 0.3 to 0.7 μm.

(Anodic Oxidation Treatment) The aluminum support thus treated is further subjected to an anodic oxidation treatment. The anodizing treatment can be performed by a method conventionally performed in this field. Specifically, sulfuric acid, phosphoric acid,
Chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid or the like or a combination of two or more of them can form an anodized film on the surface of an aluminum support by flowing a direct current or an alternating current to aluminum in an aqueous solution or a non-aqueous solution. . Since the conditions of the anodizing treatment vary depending on the electrolytic solution used, they cannot be unconditionally determined,
Generally, the concentration of the electrolyte is 1 to 80%, and the temperature of the electrolyte is 5 to 70%.
° C, current density 0.5-60 amps / dm ² , voltage 1 ~
A range of 100 V and an electrolysis time of 10 to 100 seconds is appropriate.

Among these anodic oxidation treatments, those described in GB 1,412,768 are particularly useful.
The method of anodizing at a high current density in sulfuric acid and the method of anodizing phosphoric acid as an electrolytic bath described in US Pat. No. 3,511,661 are preferred. In the present invention, the anodized film is preferably from ^{1~10g / m 2, 1g / m} 2 plate to easily enter the wound is not more than, 10 g / m ² or more is great power is required for the production Is economically disadvantageous. Preferably, 1.5 to 7 g /
m ² . More preferably, it is ² to 5 g / m ² .

Further, in the present invention, after the graining treatment and the anodic oxidation, the aluminum support may be subjected to a sealing treatment. Such a sealing treatment is performed by immersing the substrate in hot water or a hot aqueous solution containing an inorganic salt or an organic salt, a steam bath, or the like. The aluminum support of the present invention may be subjected to a surface treatment such as a silicate treatment with an alkali metal silicate or a treatment other than the silicate treatment, for example, an immersion treatment in an aqueous solution of potassium fluorozirconate, phosphate or the like.

The photosensitive lithographic printing plate of the present invention is prepared by forming a photosensitive layer comprising the above-mentioned photopolymerizable composition on an aluminum support having been subjected to the surface treatment as described above. Before coating, an organic or inorganic undercoat layer may be provided as necessary.

The photosensitive layer in the photosensitive lithographic printing plate of the present invention may be formed, for example, by using a carbon arc lamp, a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, a tungsten lamp, a halogen lamp, a helium cadmium laser, an argon ion laser, or an FD.・ YAG laser, helium neon laser, semiconductor laser (3
An image can be formed on the surface of the aluminum plate support by performing image development with a conventionally known actinic ray (e.g., 50 nm to 600 nm), followed by development. After the image exposure and before the development, a heating process at a temperature of 50 ° C. to 150 ° C. for 1 second and 5 minutes may be provided for the purpose of increasing the curing rate of the photopolymerizable photosensitive layer.

On the photosensitive layer of the photosensitive lithographic printing plate of the present invention, as described above, an overcoat layer having oxygen barrier properties is usually provided. It is known to remove the overcoat layer and remove the unexposed portion of the photosensitive layer at the same time, or to remove the overcoat layer with water or hot water first, and then remove the unexposed portion of the photosensitive layer by development. I have. These waters or warm waters include preservatives described in JP-A No. 10-10754 and JP-A No. 8-2.
An organic solvent described in No. 78636 can be contained.

The development of the photosensitive lithographic printing plate according to the present invention with the above-mentioned developer is carried out at a temperature of from 0 to 60 ° C., preferably from about 15 to 40 ° C., for example, by subjecting the photosensitive lithographic printing plate to an exposure treatment. This is performed by immersing in a developer and rubbing with a brush. Further, when the developing process is performed using an automatic developing machine, the developing solution becomes fatigued in accordance with the processing amount. Therefore, the processing capability may be restored by using a replenisher or a fresh developing solution. As described in JP-A-54-8002, JP-A-55-115045, JP-A-59-58431, etc., the photosensitive lithographic printing plate thus developed is washed with water, Post-treatment with a rinsing solution containing an agent or the like, or a desensitizing solution containing gum arabic or a starch derivative. For the post-processing of the photosensitive lithographic printing plate of the present invention, these processings can be used in various combinations. The printing plate obtained by the above processing is described in JP-A-2000-89478.
The printing durability can be improved by a post-exposure treatment or a heating treatment such as burning by the method described in (1). The lithographic printing plate obtained by such a process is set on an offset printing machine and used for printing a large number of sheets.

[0060]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which, of course, are not intended to limit the scope of the present invention. [Example 1] An aluminum plate of material 1S having a thickness of 0.30 mm was grained with a No. 8 nylon brush and an aqueous suspension of 800 mesh pumistone, and the surface was grained, followed by thorough washing with water. 60% at 70 ° C in 10% sodium hydroxide
After dipping for 2 seconds and etching, washing with running water, 20%
The resultant was neutralized and washed with HNO ₃ and washed with water. V _A = 12.7V
The electrolytic surface roughening treatment was performed in a 1% nitric acid aqueous solution at an anode electricity of 300 coulomb / dm ² using a sinusoidal alternating current under the conditions described in (1). The surface roughness was measured.
It was 45 μm (Ra indication). After immersion in a 30% H ₂ SO ₄ aqueous solution and desmutting at 55 ° C. for 2 minutes, a cathode was placed on a grained surface in a 20% H ₂ SO ₄ aqueous solution at 33 ° C. When anodized at 5 A / dm ² for 50 seconds, the thickness was 2.7 g / m ² . On the thus treated aluminum plate, a high-sensitivity photopolymerizable composition 1 having the following composition having a dry coating weight of 1.
The composition was applied so as to be 5 g / m ² and dried at 100 ° C. for 1 minute to form a photosensitive layer.

(Photopolymerizable composition 1) Ethylene unsaturated bond-containing compound (A1) 1.5 parts by weight Linear organic high molecular polymer (B1) 2.0 parts by weight Sensitizer (C1) 0.15 Parts by weight Photoinitiator (D1) 0.2 parts by weight ε-phthalocyanine (F1) dispersion 0.02 parts by weight Fluorine nonionic surfactant Megafac F177 0.03 parts by weight (manufactured by Dainippon Ink and Chemicals, Inc.) ) Methyl ethyl ketone 9.0 parts by weight Propylene glycol monomethyl ether acetate 7.5 parts by weight Toluene 11.0 parts by weight

[0062]

Embedded image

On the photosensitive layer formed as described above, polyvinyl alcohol (degree of saponification: 98 mol%, degree of polymerization: 500)
Was applied so that the dry coating weight was 2.5 g / m ^2, and dried at 120 ° C. for 3 minutes to obtain a photosensitive lithographic printing plate.

The photosensitive lithographic printing plate was subjected to FD / YAG laser (CJ plate jet 4) at 100 μJ /
After scanning and exposing a solid image and a 1-99% halftone dot image (in 1% increments) at 4,000 lines / inch and 4000 dpi at an exposure dose of cm ² , developer 1 and finishing gum solution FP Standard processing was performed using an automatic developing machine (LP-850P2 manufactured by Fuji Photo Film) charged with -2W (manufactured by Fuji Photo Film). The preheating condition is that the plate surface temperature is 1
00 ° C, developer temperature is 30 ° C, and immersion time in the developer is about 1
5 seconds. The developer 1 has the following composition and the pH is 2
It was 11.5 at 5 ° C. and the conductivity was 5 mS / cm.

(Composition of Developer 1) Potassium hydroxide 0.15 g Polyoxyethylene phenyl ether (n = 13) 5.0 g Cherest 400 (chelating agent) 0.1 g Water 94.75 g

[Examples 2 to 5]
The lithographic printing plate was made in the same manner as in Example 1 except that the developing solution was changed to that shown in Example 1.

[0067]

[Table 1]

[Examples 6 to 9] The ethylenically unsaturated bond-containing compound (A1) and the linear organic high molecular polymer (B1) of Example 1 were changed as shown in Table 2 below. A lithographic printing plate was made in the same manner as in Example 1.

[0069]

[Table 2]

[Comparative Example 1] With respect to the developing solution 1 of Example 1,
A lithographic printing plate was prepared in the same manner as in Example 1 except that the composition excluding polyoxyethylene phenyl ether was used as a developer.

[Comparative Example 2] With respect to the developing solution 1 of Example 1,
As a developer containing an alkali metal silicate, a solution obtained by diluting a LP-D developer manufactured by Fuji Photo Film Co., Ltd. 10-fold with water was used as a developer, and all other steps were the same as in Example 1 for lithographic printing. The plate was made. PH of developer at this time
Was 12.8 and the conductivity was 32 mS / cm.

Comparative Example 3 A lithographic printing plate was prepared in the same manner as in Example 1 except that the compound containing an ethylenically unsaturated bond (A1) in Example 1 was changed to A2.

[0073]

Embedded image

The lithographic printing plates obtained by the plate making methods of Examples 1 to 9 and Comparative Examples 1 to 3 were evaluated for developability, printing durability, and printing smear. The developability was determined by visually observing the plate surface after the development processing, and by judging the presence or absence of the remaining photosensitive layer and the degree of the remaining film. The printing durability was evaluated by printing with a R201 type printing machine manufactured by Man Roland Co., Ltd. using GEOS G black (N) manufactured by Dainippon Ink Co., Ltd., and the number of printed sheets in which 3% of halftone dots caused plate skipping was evaluated. The print stain was printed on a diamond IF2 type printer manufactured by Mitsubishi Heavy Industries using GEOS G Beni (S) manufactured by Dainippon Ink and the ink stain in the non-image area was visually evaluated. Table 3 shows the results.

[0075]

[Table 3]

As is clear from Table 3, the planographic printing plates of the examples according to the present invention obtained satisfactory results, but the planographic printing plates of the comparative examples were not satisfactory in some evaluation results. there were.

[0077]

As described above, the method for making a lithographic printing plate according to the present invention is a method for preparing a lithographic printing plate having a photosensitive layer comprising a photopolymerizable composition, and an aqueous alkali solution having a relatively low pH. By using a developer containing a nonionic surfactant having a structure, a lithographic printing plate having good developability, no printing stains, and excellent printing durability can be produced. Further, since the developer has excellent stability over time and the pH of the developer is relatively low, it is preferable from the viewpoint of safety and has an effect of improving the influence of the waste developer on the environment.

Claims (1)

[Claims] 1. A photosensitive composition comprising a photopolymerizable photosensitive composition containing a compound having a nitrogen atom and an ethylenically unsaturated double bond, a photopolymerization initiator, and a polymer binder on an aluminum support. After the imagewise exposure of the photosensitive lithographic printing plate having a layer, developing with a developer containing (1) an inorganic alkali agent and (2) a nonionic surfactant having a polyoxyalkylene ether group. A feature of the lithographic printing plate making method.