JP2002296764A - Photosensitive planographic printing plate and method for producing printing plate - Google Patents

Abstract

(57) [Problem] To provide a photosensitive lithographic printing plate suitable for blue-violet laser exposure. SOLUTION: In a photosensitive lithographic printing plate having a photosensitive layer and a protective layer in this order on a support, the photosensitive layer is 390.
Having a maximum spectral sensitivity peak in a wavelength range of ~ 430 nm,
At a wavelength of 410 nm, an image forming minimum exposure amount (S
410) is 100 μJ / cm ² or less, and the wavelength 4
The minimum exposure amount at which an image can be formed at 50 nm (S45
A photosensitive lithographic printing plate, wherein the ratio (S410 / S450) of the minimum exposure amount (S410) at 410 nm wavelength to which an image can be formed is 0.1 or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to 390-430n
The present invention relates to a photosensitive lithographic printing plate and a method of making a printing plate, which have high sensitivity to a laser beam of m and are suitable for direct drawing from a digital signal from a computer or the like.

[0002]

2. Description of the Related Art Conventionally, a lithographic printing plate, a printed circuit board, a color filter, a large scale integrated circuit (LSI), a thin transistor (TFT), a liquid crystal display (LCD), a plasma display (PDP), a semiconductor package (TA).
In the fine processing such as B), an image forming material in which a layer of a photosensitive composition is formed on the surface of a support is image-exposed through a mask, and a difference in solubility between an exposed portion and a non-exposed portion in a developing solution is used. Lithographic methods for forming patterns have been widely used.

For example, a combination of a hexaarylbiimidazole derivative and an aminobenzophenone derivative is known as a photopolymerization initiation system for a resist material for a color filter (Japanese Patent Application Laid-Open No. 11-327127). However, the resist material for the color filter is
Instead of using a laser for exposure, a high-pressure mercury lamp or the like is used as an exposure source through a mask.
Further, since a large amount of pigment is contained, for example, 2
A large amount of energy of 00 mJ / cm ² is required. U.S. Pat. No. 5,863,678 discloses a resist material for a color filter containing a titanocene compound and a dialkylaminobenzene compound as a photopolymerization initiation system. However, the resist material actually uses a high-pressure mercury lamp or the like as an exposure source via a mask, and has an exposure energy of 80 to 200 mJ / cm ^2.
It is. Further, the above-mentioned publication does not disclose safe light resistance under a yellow light as a photosensitive lithographic printing plate.

On the other hand, in recent years, a laser direct drawing method for forming an image directly from digital information of a computer or the like without using a mask by using a laser beam as an exposure light source has been used not only in productivity but also in resolution. The use of laser light has also been actively studied in the lithography method as well, as it is possible to improve the accuracy and position accuracy.

[0005] Various light sources from ultraviolet to infrared are known as laser light. Laser light that can be used for image exposure includes argon light in terms of output, stability, photosensitivity and cost. Ion lasers, helium neon lasers, YAG lasers, and semiconductor lasers that emit light in the visible to infrared region are considered promising. For example, for 488-nm argon ion lasers and 532-nm FD-YAG lasers Various photosensitive compositions have been proposed, and the photosensitive lithographic printing plate for laser exposure has been put to practical use.

As such a photosensitive composition, for example, a combination of a titanocene compound and a bipyrromethene complex, a combination of titanocene and a coumarin derivative, and the like are known (for example, JP-A-11-271969). However, these conventionally known photosensitive compositions for laser exposure do not pay attention to the blue-violet laser light of 390 to 430 nm.
Only the sensitivity at 532 nm corresponding to the YAG laser is shown.

In the image forming method using such a visible laser beam, a photosensitive composition having a sufficient absorption in the visible region is used, so that the sensitivity to a blue-violet laser beam of 390 to 430 nm is insufficient. In some cases, it is inferior in safelight property under yellow light (environment including light having a wavelength of about 500 to 750 nm), and it is necessary to work in a dark room environment such as red light illumination. Yes.

On the other hand, Japanese Patent Publication No. 7-60268 discloses a photosensitive lithographic printing plate excellent in suitability for safe light having a protective layer containing a specific colorant on a photopolymerizable photosensitive composition layer. A lithographic printing plate is disclosed, as well as a general-purpose light source such as a high-pressure mercury lamp and a metal halide lamp as an exposure source, an argon ion laser, a helium cadmium laser, and a krypton laser are disclosed. Are also illustrated. However, in this publication, specifically, a relative sensitivity of 480 nm when exposed with a xenon lamp, 488 nm when an argon ion laser is used, and helium-
Focusing on the irradiation energy required for image formation at 442 nm when using a cadmium laser,
No attention has been paid to a laser having an oscillation wavelength of 30 nm, especially 400 to 420 nm, and the irradiation energy required for image formation with a 442 nm helium-cadmium laser is still sufficient to be 0.6 to 1.0 mJ / cm ^2. Not something.

On the other hand, due to the remarkable progress in laser technology in recent years, lasers in the ultraviolet region, which can be operated in a bright room environment such as yellow light illumination, and among them, 390-400
Semiconductor lasers that can stably oscillate in the wavelength region of 430 nm, particularly 400 to 420 nm are becoming available. However, a photosensitive lithographic printing plate suitable for laser exposure in the blue-violet light region (laser of 390 to 430 nm) has not been found.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and accordingly, an object of the present invention is to provide a photosensitive lithographic printing plate having high sensitivity for blue-violet laser exposure. To provide. Another object of the present invention is to provide a method of making a printing plate using the photosensitive lithographic printing plate.

[0011]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, as a photosensitive composition for laser exposure of 390 to 430 nm, the maximum peak of the spectral sensitivity was set to a specific wavelength region. It has been found that a photosensitive composition having a minimum exposure amount capable of forming an image at a wavelength of 410 nm is equal to or less than a specific value can achieve the above object, thereby completing the present invention.

That is, the gist of the first invention is that in a photosensitive lithographic printing plate having a photosensitive layer and a protective layer in this order on a support, the photosensitive layer has a maximum spectral sensitivity in a wavelength range of 390 to 430 nm. The photosensitive lithographic printing plate has a minimum exposure amount at which the image can be formed at a wavelength of 410 nm (S4
10) is 100 μJ / cm ² or less, and the wavelength 45
Minimum exposure for image formation at 0 nm (S450)
And the minimum exposure amount at which the image can be formed at a wavelength of 410 nm (S410) is 0 <S410 / S450 ≦
0.1 in a photosensitive lithographic printing plate.

Further, the present inventors have found that a photosensitive composition comprising an ethylenic monomer and a specific photopolymerization initiation system can achieve the above object, and have completed the present invention. The gist of the invention is that a photosensitive lithographic printing plate having (A) an ethylenic monomer, (B) a sensitizing dye, (C) a photosensitive layer containing a radical generator and a protective layer on a support in this order. , (C) a radical generator contains a hexaarylbiimidazole compound or a titanocene compound, and (B) a lithographic printing plate containing a sensitizing dye containing a dialkylaminobenzene compound.

Further, the gist of the third invention is that the photosensitive lithographic printing plate of the first or second invention is used in a wavelength range of 390 to 430.
The present invention relates to a plate-making method for a printing plate, which comprises exposing an image with a laser beam of nm and developing with an aqueous developer.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
First, the first present invention will be described. The photosensitive lithographic printing plate of the present invention has a photosensitive layer and a protective layer in this order on a support, and the photosensitive layer has a maximum spectral sensitivity peak in a wavelength range of 390 to 430 nm, and Wavelength 410nm
The minimum exposure that can form an image is 100 μJ / cm
² or less and a wavelength of 410 nm with respect to the minimum exposure amount (S450) at which an image can be formed at a wavelength of 450 nm.
Is less than or equal to 0.1 (S410 / S450).

The maximum peak of the spectral sensitivity is 400 to 420
More preferably, it is in the wavelength range of nm. When the spectral sensitivity has a maximum peak in a wavelength range less than the above range, the photosensitive composition is inferior in sensitivity to laser light of 390 to 430 nm (hereinafter, sometimes referred to as blue-violet laser light). On the other hand, when the wavelength is in the wavelength range exceeding the above range, the safelight property under yellow light is inferior even with high sensitivity to laser light in the blue-violet region.

At a wavelength of 410 nm, the minimum exposure for forming an image is 100 μJ / cm ² or less.
It is preferably at most 50 μJ / cm ^2, more preferably at most 35 μJ / cm ² . When the minimum exposure amount is more than 100 μJ / cm ² , the exposure time becomes long, depending on the exposure intensity of the laser light source, and is not practical. Although the lower limit is preferably as small as possible, it is usually 1 μJ / cm ² or more.
2.5 μJ / cm ² or more.

In the present invention, the "maximum spectral sensitivity peak" is described in detail in, for example, "Photopolymer Technology" (Ao Yamaoka, published by Nikkan Kogyo Shimbun in 1988, p. 262). It is obtained as follows in accordance with the method described above. That is, a photosensitive image-forming material sample in which a layer (photosensitive layer) made of a photosensitive composition is formed on the surface of a support is irradiated with light that is spectrally separated from a light source such as a xenon lamp or a tungsten lamp using a spectral sensitivity measuring device. Exposure (at this time, irradiation is performed so that the exposure wavelength is linearly decreased in the horizontal axis direction and the exposure intensity is decreased logarithmically in the vertical axis direction), and the exposure is performed by developing the sample. A resist image corresponding to the wavelength is obtained, and the exposure energy at which an image can be formed is calculated from the image height. The exposure wavelength indicating the maximum peak in the spectral sensitivity curve obtained by plotting the wavelength on the horizontal axis and the reciprocal of the exposure energy on the vertical axis corresponds to the maximum peak in spectral sensitivity.

The minimum exposure amount at which an image can be formed at a wavelength of 410 nm is obtained as exposure energy calculated from the height of an image obtained using a spectral sensitivity measuring device in the same manner as described above. The minimum exposure amount at which an image can be formed is determined by, after exposing the photosensitive layer, changing the type of the developing solution such as the pH of the developing solution, the developing temperature, the developing time, etc., according to the type of the photosensitive composition. Is the minimum exposure amount at which an image can be formed by developing under optimum development conditions.
Means the minimum exposure amount at which an image can be formed by immersion in an alkaline developer at 25 ° C. for 30 seconds to 3 minutes.

Further, the photosensitive lithographic printing plate of the present invention has a minimum exposure amount S450 at which an image can be formed at a wavelength of 450 nm.
(J / cm ² ) ratio S4 of minimum exposure amount S410 (J / cm ² ) at which image formation is possible at a wavelength of 410 nm.
10 / S450 is 0.1 or less. S410 / S45
The value of 0 is preferably 0.05 or less. That is,
Minimum exposure amount S capable of forming an image at a wavelength of 450 nm
If 450 is large and the minimum exposure amount S410 capable of forming an image at a wavelength of 410 nm is small, 500
The handleability is excellent in an environment containing light having a wavelength of around nm, that is, under a yellow light, and the smaller the above ratio, the better. Note that the minimum value of S410 / S450 is 0, which means that S450 is infinite, ie, 450n
It means that it is completely insensitive to light having a wavelength of m.

In addition, from the viewpoint of handling under yellow light, 45
It is preferable that the minimum exposure amount capable of forming an image at a wavelength longer than 0 nm is larger than the minimum exposure amount capable of forming an image at 450 nm. More specifically, it is preferable that the minimum exposure amount at which an image can be formed at each wavelength exceeding 450 nm and at most 750 nm is larger than the minimum exposure amount at which an image can be formed at 450 nm (S450). It is particularly preferable that the maximum peak of the spectral sensitivity of the photosensitive layer in the wavelength range of 390 to 430 nm is the maximum peak of the spectral sensitivity in the wavelength range of 390 to 750 nm. The photosensitive lithographic printing plate is, among others, 400 to 4
It is particularly useful for laser exposure having an oscillation wavelength of 20 nm.

The constituents of the photosensitive layer in such a photosensitive lithographic printing plate are not particularly limited as long as they satisfy the above-mentioned rules. It is preferable to use a photopolymerizable composition containing an ethylenic compound and a photopolymerization initiation system (a combination of a sensitizing dye and a radical generator) because of its advantageous properties. Next, the photosensitive lithographic printing plate of the second invention will be described. The photosensitive lithographic printing plate is a photosensitive lithographic printing plate containing specific components for achieving the physical properties of the photosensitive layer of the photosensitive lithographic printing plate of the first invention.

<Ethylenic monomer> In the present invention,
(A) As the ethylenic monomer, when the photosensitive composition is irradiated with an actinic ray, it undergoes addition polymerization by the action of a photopolymerization initiation system, and in some cases, crosslinks and cures. A compound having an ethylenic double bond,
Compound having one ethylenic double bond in one molecule, specifically, for example, acrylic acid, methacrylic acid (hereinafter, “acryl” and “methacryl” are collectively referred to as “(meth) acryl”) Unsaturated carboxylic acids such as crotonic acid, isocrotonic acid, maleic acid, itaconic acid, citraconic acid, and alkyl esters thereof;
(Meth) acrylonitrile, (meth) acrylamide,
It may be styrene or the like. However, polymerizability, crosslinkability,
A compound having two or more ethylenic double bonds in one molecule is preferable from the viewpoint that the difference in solubility between the exposed part and the unexposed part in the developing solution can be enlarged.

Examples of the ethylenic monomer include (A-
1) Esters of unsaturated carboxylic acid and aliphatic polyhydroxy compound, (A-2) Phosphates containing acryloyloxy group or methacryloyloxy group, (A-3)
Examples include urethane (meth) acrylates and (A-4) epoxy (meth) acrylates.

The esters (A-1) of the unsaturated carboxylic acid and the aliphatic polyhydroxy compound include the unsaturated carboxylic acid as described above, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, With aliphatic polyhydroxy compounds such as trimethylene glycol, 1,3-butanediol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol and sorbitol There are esters, and specifically, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate Acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, neopentyl glycol di (meth)
Acrylate, hexamethylene glycol di (meth) acrylate, trimethylolethane tri (meth) acrylate, tetramethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerol di (meth) acrylate, glycerol tri (meth) Acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol di (meth) acrylate
Acrylate, dipentaerythritol tetra (meth)
Acrylate, dipentaerythritol penta (meth)
Acrylate, dipentaerythritol hexa (meth)
Acrylates, sorbitol tri (meth) acrylate, sorbitol tetra (meth) acrylate, sorbitol penta (meth) acrylate, sorbitol hexa (meth) acrylate, and similar crotonates, isocrotonates, maleates, itaconates, citracons, and the like are included.

The acryloyloxy group or methacryloyloxy group-containing phosphate (A-2) is not particularly limited as long as it is a phosphate compound having a (meth) acryloyloxy group in its structure. ) Or (Ib).

[0027]

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[In the formulas (Ia) and (Ib), R ¹ represents a hydrogen atom or a methyl group, n is an integer of 1 to 25, and m is 1, 2, or 3. Here, n is preferably 1 to 10, particularly preferably 1 to 4. Specific examples thereof include, for example, methacryloyloxyethyl phosphate, bis (methacryloyloxyethyl) phosphate, methacryloyloxyethylene glycol phosphate and the like. These may be used alone or as a mixture.

Urethane (meth) acrylates (A-
Examples of 3) include aliphatic polyisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; alicyclic polyisocyanates such as cyclohexane diisocyanate and isophorone diisocyanate; and aromatic polyisocyanates such as tolylene diisocyanate, xylylene diisocyanate, and diphenylmethane diisocyanate. Polyisocyanate compound such as isocyanate and unsaturated hydroxy such as hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, glycerol di (meth) acrylate, pentaerythritol tri (meth) acrylate, tetramethylolethane tri (meth) acrylate There are urethane (meth) acrylates with compounds, and specifically, for example, hexamethylenebi [(Meth) acryloyloxymethylurethane], hexamethylenebis [(meth) acryloyloxyethylurethane], hexamethylenebis {tris [(meth) acryloyloxymethyl] methylurethane}, hexamethylenebistris [(meth) acryloyl [Oxymethyl] ethyl urethane} and the like.

Epoxy (meth) acrylates (A-
Examples of 4) include (poly) ethylene glycol polyglycidyl ether, (poly) propylene glycol polyglycidyl ether, (poly) tetramethylene glycol polyglycidyl ether, (poly) pentamethylene glycol polyglycidyl ether, (poly) neopentyl Glycol polyglycidyl ether, (poly) hexamethylene glycol polyglycidyl ether, (poly) trimethylolpropane polyglycidyl ether,
Epoxy (meth) of a polyepoxy compound such as (poly) glycerol polyglycidyl ether or (poly) sorbitol polyglycidyl ether and a hydroxy (meth) acrylate compound such as hydroxymethyl (meth) acrylate or hydroxyethyl (meth) acrylate
Acrylates are mentioned.

The ethylenic monomers other than those described above include, for example, aromatic polyhydroxy compounds such as hydroquinone di (meth) acrylate, resorcinol di (meth) acrylate, and pyrogallol tri (meth) acrylate, and unsaturated carboxylic acids. Esters, ethylene glycol (meth) acryloyl ethylene oxide adduct,
(Meth) acryl hydroxy compounds such as (meth) acryloyl diethylene oxide adduct of 2,2-bis (4-hydroxyphenyl) propane, and condensates of ethylene glycol, (meth) acrylic acid and phthalic acid, diethylene glycol Such as condensates of (meth) acrylic acid and maleic acid, condensates of pentaerythritol, (meth) acrylic acid and terephthalic acid, and condensates of butanediol, glycerin, (meth) acrylic acid and adipic acid Condensates of a hydroxy compound, an unsaturated carboxylic acid and a polycarboxylic acid are exemplified. Further, amides of the above unsaturated carboxylic acids and aliphatic polyamine compounds such as methylene diamine, ethylene diamine, diethylene triamine, hexamethylene diamine, etc., specifically, for example, methylene bis (meth) acrylamide, ethylene bis (meth) Acrylamide, diethylenetriaminetris (meth) acrylamide, hexamethylenebis (meth) acrylamide and the like can be mentioned.

Among the above, it is preferable to contain a phosphate containing a (meth) acryloxy group, and the above-mentioned (meth) acryloyloxy group occupying the whole of the ethylenic monomer as one component of the photosensitive layer is preferable. The content of the phosphates is preferably 1 to 60% by weight, particularly preferably 2 to 40% by weight. Within this range, the exposure sensitivity and printing durability of the photosensitive layer are improved, and the developability (dirt of the non-image tip portion) is improved.

Among the above, it is preferable to contain urethane (meth) acrylates, and among the urethane (meth) acrylates, (a3) four or more urethane bonds [-NH- ( C = O) -O-] and a urethane compound having four or more addition-polymerizable double bonds. The method for producing the urethane compound is not particularly limited, but isocyanate groups (—N
ＣC ＝ O) and a hydroxyl group can easily form a urethane bond, so that (a1) a compound having four or more active isocyanate groups in one molecule, and (a2) one or more compounds in one molecule. It is preferably obtained by reacting a hydroxyl group with a compound having two or more addition-polymerizable double bonds. The following can be considered as factors of the sensitivity improving effect by the addition of the urethane compound (a3). For example,
The generation of a urethane active radical by a chain transfer reaction or the photopolymerization of a multifunctional acrylate group of the urethane compound (a3) induces a high photocuring action, and this photocuring action causes a high molecular weight of the urethane compound (a3). And the like.

Examples of the compound (a1) having four or more active isocyanate groups in one molecule include a compound having two or more alcoholic hydroxyl groups (hereinafter, referred to as polyhydric alcohols) and an isocyanate group. And a compound having four or more active isocyanate groups introduced by reaction with a compound having two or more. Specifically, a compound containing four or more alcoholic hydroxyl groups in one molecule such as pentaerythritol and polyglycerin is reacted with a diisocyanate compound such as hexamethylene diisocyanate, toluene diisocyanate, isophorone diisocyanate, and trimethylhexamethylene diisocyanate. Compound obtained by using Asahi Kasei Kogyo Co., Ltd., a compound containing two or more alcoholic hydroxyl groups in one molecule such as ethylene glycol.
4A-100, 22A-75PX, 21S-75E, 1
Biuret type such as 8H-70B; P-301-75
Compounds obtained by reacting a compound containing at least three or more isocyanate groups in one molecule such as an adduct type such as E, E-402-90T, and E-405-80T are exemplified.

Further, a compound having an average of four or more isocyanate groups in one molecule can be obtained by copolymerizing isocyanateethyl methacrylate alone or with other components. Specific examples of the compound (a1) containing four or more isocyanate groups in one molecule include, for example, Duranate ME20-100 (trade name, manufactured by Asahi Chemical Industry Co., Ltd.).

The number of isocyanate groups in the compound (a1) is preferably 6 or more, particularly preferably 7 or more. When the number of isocyanate groups is less than 4, fluorescence is inferior in sensitivity. The upper limit is not particularly limited, but if it is too large, it is difficult to synthesize, so it is preferably 20 or less. The number of isocyanate groups can be adjusted by the number of hydroxyl groups in the polyhydric alcohol and the type and compounding ratio of the compound having two or more isocyanate groups. The molecular weight of compound (a1) is usually at least 500, preferably at least 1,000, and at most 200,000, preferably at most 150,000. If it is out of this range, the sensitivity may be reduced.

Examples of the compound (a2) constituting the urethane compound (a3) having one or more hydroxyl groups and two or more addition-polymerizable double bonds in one molecule include polyhydric alcohols. A compound having one or more alcoholic hydroxyl groups, ie, a compound obtained by an esterification reaction of a compound having a plurality of alcoholic hydroxyl groups and a compound having a carboxyl group and a (meth) acryloyl group. A reaction product obtained by reacting the carboxyl group-containing compound at such a ratio that at least one hydroxyl group remains. More specifically, acrylic acid 3
Mole of pentaerythritol, 2 moles of acrylic acid and 1 mole of pentaerythritol, 5 moles of acrylic acid and 1 mole of dipentaerythritol, 4 moles of acrylic acid and dipentane A hydroxyl-containing polyfunctional acrylate compound which is an ester of a polyhydric alcohol such as a compound obtained by reacting 1 mol of erythritol with acrylic acid and has one or more alcoholic hydroxyl groups, and a specific compound is pentaerythritol Examples include triacrylate, pentaerythritol diacrylate, dipentaerythritol diacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, and dipentaerythritol pentaacrylate.
These compounds may be used alone or in a mixture.

As another example of the compound of the component (a2), a compound containing an epoxy group such as glycidyl methyl ether may be used in combination with at least one carboxyl group and at least one addition polymerizable double bond. Reactant with a compound having a bond; or reaction of a compound having at least one or more epoxy groups and at least one or more addition-polymerizable double bonds simultaneously with a compound having at least one or more carboxyl groups Or a compound having at least one or more carboxyl groups and at least one or more addition-polymerizable double bonds, and having at least one or more epoxy groups and at least one or more addition-polymerizable double bonds Reactants with compounds; For example, a reaction product of glycidyl methacrylate and (meth) acrylic acid is given as an example.

As the compound (a2), it is particularly preferable to have three or more double bonds capable of addition polymerization in terms of sensitivity. Reaction of compound (a1) with compound (a2),
The reaction between the isocyanate group of the compound (a1) and the hydroxyl group of the compound (a2) to obtain the urethane compound (a3) can be performed according to a known method. Specifically, the isocyanate group of the compound (a1) and the compound (a
The reaction is carried out by reacting the hydroxyl groups in 2) at a ratio of 1/10 to 10; for example, after diluting them with an organic solvent such as toluene or ethyl acetate, the mixture is diluted at 10 to 150 ° C. for 5 minutes to 3 minutes.
A method of heating for about 0 hours; or a method of adding a catalytic amount of a catalyst such as n-butyltin dilaurate; first, a compound (a2) is diluted in an appropriate organic solvent, and then a compound (a1) is sequentially added dropwise thereto. Method; or the reverse method.

The molecular weight of the urethane compound (a3) is preferably at least 600. If it is less than 600, the layer (uncured film) composed of the photosensitive composition tends to be inferior in the fastness. On the other hand, the upper limit is not particularly limited, but is preferably 150,000 or less from the viewpoint of easy synthesis and availability. The molecular weight can be determined by adjusting the types of the compounds (a1) and (a2) and the esterification rate.

The urethane compound (a3) has four or more double bonds capable of addition polymerization, and preferably has six or more, particularly preferably eight or more, in terms of sensitivity of the photosensitive composition. The urethane compound (a3) may be used alone or in a mixture. In particular, when the raw material of the urethane-based compound is a mixture, the urethane-based compound (a3) uses a reactant as a mixture.

In producing the urethane compound (a3), a functional group other than a double bond capable of addition polymerization may be introduced for the purpose of controlling various properties of the photosensitive composition.
For example, a compound (a4) having a hydroxyl group and a carboxyl group in one molecule is used in combination with the compound (a2) and reacted with the compound (a1) to form four or more urethane bonds in one molecule, A compound having a polymerizable double bond and a carboxyl group can be obtained. More specifically, a compound (a1 ′) having four isocyanate groups in one molecule, a compound (a2 ′) having one hydroxyl group and two double bonds capable of addition polymerization in one molecule, When a compound (a4 ′) having one hydroxyl group and one carboxyl group in the molecule is reacted at a molar ratio of a1 ′: a2 ′: a4 ′ of 1: 3: 1, four compounds are formed in one molecule. A compound (a3 ′) having a urethane bond and having an average of six double bonds and one carboxyl group can be produced.

The compound (D) (compound having a hydroxyl group and a carboxyl group in one molecule) which can be reacted with the compound (A) in combination with the compound (B) is, for example, 2-hydroxyoctane. Preferred are aliphatic carboxylic acids having a hydroxyl group such as acids, 2-hydroxyhexanoic acid, 2-hydroxydecanoic acid, 3-hydroxyoctanoic acid, and 8-hydroxyoctanoic acid. Among them, carbons having a hydroxyl group at the α-position of the carboxylic acid are preferable. Carboxylic acids of numbers 4 to 20 are preferred.

As the urethane compound (a3), a specific urethane compound represented by the following general formula (II) is preferable.

[0045]

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[In the formula (II), x is an integer of 4 to 20, y is
Represents an integer of 0 to 15; z represents an integer of 1 to 15;
Represents an oxy group having a repeating unit derived from alkyleneoxy or aryleneoxy, and capable of bonding to Rb.
Rb and Rc each independently represent a C1-10 alkylene group; Rd represents a (meth) acryl group;
Represents an organic residue having 10 to 10, Ra, Rb, Rc,
Rd may each independently have a substituent. ]

In the formula, the alkyleneoxy group used in the repeating unit of Ra is an alkyleneoxy residue such as glycerin, pentaerythritol, and propylenetriol, and the aryleneoxy group used in the repeating unit of Ra is pyrogallol. And phenoxy residues such as 1,3,5-benzenetriol. x represents an integer of 4 to 15, y represents an integer of 1 to 10, z represents an integer of 1 to 10, Ra and Rc independently represent a C1 to 5 alkylene group, and Rd represents a (meth) acryl group of 1 Those representing an organic residue having up to 7 are preferred. More preferably, Ra is

[0048]

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(Where k is 2 to 10), and Rb, R
c is -C ₂ independently _{H 4 -, - CH 2 -C} (CH 3) -, or, -C ₃ H ₆ - and is, Rd is

[0050]

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Is as follows. The compounding ratio of the urethane compound (a3) is as follows, based on 100 parts by weight of the ethylenic monomer.
It is 0.5 to 50 parts by weight, preferably 1 to 40 parts by weight, more preferably 2 to 30 parts by weight.

<Photopolymerization initiation system> The photopolymerization initiation system is usually
(C) a radical generator and (B) a sensitizing dye, and
Further, it contains a hydrogen-donating compound as a polymerization accelerator.
The (C) radical generator receives the photoexcitation energy of the sensitizing dye when the (B) sensitizing dye is irradiated with actinic light, generates an active radical by the energy, and polymerizes the ethylenic monomer. Is a compound that leads to
The photosensitive layer component of the photosensitive lithographic printing plate according to the second aspect of the present invention contains (C) a hexaarylbiimidazole compound or a titanocene compound as a radical generator, and (B) a dialkylaminobenzene compound as a sensitizing dye. I do.

Here, the hexaarylbiimidazole compound is a dimer of an imidazole compound having three aryl groups, and is exposed to a laser beam of 390 to 430 nm directly or by interaction with a coexisting sensitizer. Any compound that generates a radical may be used. Examples of the hexaarylbiimidazole-based compound include, for example,
JP-A-45-37377, JP-A-47-2528, JP-A-54-1552
No. 9, for example, hexaarylbiimidazole compounds. Specifically, for example, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimide Imidazole, 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetra (p-methoxyphenyl) biimidazole, 2,2'-bis (o-
(Chlorophenyl) -4,4 ', 5,5'-tetra (p-
Methylphenyl) biimidazole, 2,2'-bis (o
-Chlorophenyl) -4,4 ', 5,5'-tetra (p
-Ethoxycarbonylphenyl) biimidazole, 2,
2'-bis (o-chlorophenyl) -4,4 ', 5
5′-tetra (p-fluorophenyl) biimidazole, 2,2′-bis (o-bromophenyl) -4,
4 ', 5,5'-tetra (p-iodophenyl) biimidazole, 2,2'-bis (o-chlorophenyl)-
4,4 ', 5,5'-tetra (p-chloronaphthyl) biimidazole, 2,2'-bis (o-chlorophenyl)
-4,4'5,5'-tetra (p-chlorophenyl) biimidazole, 2,2'-bis (o-bromophenyl)
-4,4 ', 5,5'-tetra (p-chloro-p-methoxyphenyl) biimidazole, 2,2'-bis (o-
Chlorophenyl) -4,4 ′, 5,5′-tetra (o,
p-dichlorophenyl) biimidazole, 2,2′-bis (o-chlorophenyl) -4,4′5,5′-tetra (o, p-dibromophenyl) biimidazole,
2'-bis (o-bromophenyl) -4,4'5,5 '
-Tetra (o, p-dichlorophenyl) biimidazole, 2,2'-bis (o, p-dichlorophenyl)-
4,4'5,5'-tetra (o, p-dichlorophenyl) biimidazole and the like can be mentioned, among which a hexaphenylbiimidazole compound is preferable, and benzene at the 2,2'-position on the imidazole ring is particularly preferable. It is preferable that the ortho position of the ring is substituted with halogen, and it is further preferable that the benzene ring at the 4,4 ', 5,5' position on the imidazole ring is unsubstituted, or substituted with halogen or alkoxycarbonyl.

These hexaarylbiimidazoles can be used in combination with various kinds of biimidazoles, if necessary. Biimidazoles are, for example, Bul
l. Chem. Soc. Japan. 33,565 (1
960) and J.M. Org. Chem. 36 [16] 22
62 (1971).

As the titanocene compound, specifically,
For example, dicyclopentadienyl titanium dichloride, dicyclopentadienyl titanium bisphenyl,
Dicyclopentadienyl titanium bis (2,4-difluorophenyl), dicyclopentadienyl titanium bis (2,6-difluorophenyl), dicyclopentadienyl titanium bis (2,4,6-trifluorophenyl) , Dicyclopentadienyl titanium bis (2,3,5,6-tetrafluorophenyl), dicyclopentadienyl titanium bis (2,3,4,5,6
-Pentafluorophenyl), di (methylcyclopentadienyl) titanium bis (2,6-difluorophenyl), di (methylcyclopentadienyl) titanium bis (2,3,4,5,6-pentafluorophenyl) ,
Titanium compounds having a dicyclopentadienyl structure and a biphenyl structure, such as dicyclopentadienyltitanium bis [2,6-difluoro-3- (1-pyrrolyl) phenyl], are listed at the o-position of the biphenyl ring. Those in which a halogen atom is substituted are preferred.

Further, it is also preferable to use the above-mentioned hexaarylbiimidazole compound and titanocene compound in combination as a radical generator. Next, (B) the dialkylaminobenzene-based compound used as a sensitizing dye has a dialkylaminobenzene structure,
The compound may absorb any light having a wavelength of m, and may have any substituent as long as it is a compound that efficiently generates radicals from the radical generator by interacting with the radical generator. Aminobenzophenone compounds, dialkylaminobenzene compounds having an aromatic heterocyclic group as a substituent at the carbon atom at the p-position to the amino group on the benzene ring, and the alkyl group constituting the dialkylamino group of these compounds Are preferably bonded to each other and / or the alkyl group is bonded to a carbon atom adjacent to the carbon atom to which the amino group on the benzene ring is bonded to form a nitrogen-containing heterocyclic structure. In the above, the amino groups constituting the dialkylamino group may be the same or different, and preferably have 1 to 6 carbon atoms.

Among them, preferred dialkylaminobenzene compounds are represented by the following formulas (IIIa) and (IIIb).

[0058]

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[0059] (In the formula (IIIa), R ² ~R ⁵ are each independently an alkyl group having 1 to 6 carbon atoms, R ⁶ to R
⁹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, wherein R ² and R ³ , R ⁴ and R ⁵ , R ² and R ⁶ , R ³ and R ⁷ , R ⁴ and R ⁸ , R ⁵ And R ⁹ may be independently bonded to each other to form a ring. )

[0060]

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(In the formula (IIIb), R ¹⁰ and R ¹¹ each independently represent an alkyl group having 1 to 6 carbon atoms, and R ¹³ and R ¹⁴
Is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms,
Y is a sulfur atom, an oxygen atom, a dialkylmethylene or-
N (R ¹⁵ ) —, wherein R ¹⁵ is a hydrogen atom or carbon 1-6
Represents an alkyl group. However, R ¹⁰ and R ¹¹ , R ¹⁰ and R ¹³ or R ¹¹ and R ¹⁴ may be independently bonded to form a ring. ) The alkyl group of the dialkylmethylene has 1 to 6 carbon atoms, preferably 1. Formulas (IIIa) and (I
In the case where any one of R ^{2 to} R ¹⁴ is bonded to form a ring in IIb), the ring is preferably a 5- or 6-membered ring, and particularly preferably a 6-membered ring. Examples of the compound represented by the general formula (IIIa) include 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, and a compound having the following structure.

[0062]

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The compound represented by the general formula (IIIb) includes 2- (p-dimethylaminophenyl)
Benzoxazole, 2- (p-diethylaminophenyl) benzoxazole, 2- (p-dimethylaminophenyl) benzo [4,5] benzoxazole, 2-
(P-dimethylaminophenyl) benzo [6,7] benzoxazole, 2,5-bis (p-diethylaminophenyl) 1,3,4-oxazole, 2- (p-dimethylaminophenyl) benzothiazole, 2- ( p-diethylaminophenyl) benzothiazole, 2- (p-dimethylaminophenyl) benzimidazole, 2- (p
-Diethylaminophenyl) benzimidazole and compounds of the following structure:

[0064]

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Examples of the dialkylaminobenzene compounds other than the formulas (IIIa) and (IIIb) include 2,5-bis (p-diethylaminophenyl) 1,3,4-thiadiazole, (p-dimethylaminophenyl) pyridine,
(P-diethylaminophenyl) pyridine, 2- (p-
Dimethylaminophenyl) quinoline, 2- (p-diethylaminophenyl) quinoline, 2- (p-dimethylaminophenyl) pyrimidine, 2- (p-diethylaminophenyl) pyrimidine and the like.

Incidentally, in view of the handling property under a yellow light, in particular, in order for S410 / S450 to be 0.1 or less,
A photopolymerization initiation system which is a combination of (C) a hexaarylbiimidazole compound as a radical generator and (B) a dialkylaminobenzene compound as a sensitizing dye is preferred. In addition, the photosensitive composition for blue-violet laser light of the present invention preferably contains a hydrogen-donating compound component as a polymerization accelerator, in addition to the above components, for the purpose of improving photopolymerization initiation ability.

Specific examples of the hydrogen-donating compound include mercapto groups such as 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, and 3-mercapto-1,2,4-triazole. Compounds such as N, N-dialkylbenzoic acid alkyl ester, N-phenylglycine, N-phenylglycine salt, N-phenylglycine ethyl ester, N-phenylglycine benzyl ester and the like.
Examples thereof include N-aryl-α-amino acids such as alkyl esters of phenylglycine or salts and esters thereof, and compounds represented by the following general formula (IV).

[0068]

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In the formula (IV), R ¹⁶ represents a hydrogen atom or an alkyl group which may have a substituent, R ¹⁷ represents a hydrogen atom,
An alkyl group which may have a substituent, a vinyl group which may have a substituent, an allyl group which may have a substituent, a (meth) acryloyl group which may have a substituent, An aryl group which may have a substituent or an aromatic heterocyclic group which may have a substituent, wherein the benzene ring may have a substituent;
Is an integer of 2 to 10.

The photosensitive lithographic printing plate of the present invention contains a polymer binder in addition to the above components in the photosensitive layer for the purpose of improving the coating properties and the developability when the photosensitive layer is coated. Is preferred. Specific examples of the polymer binder include (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylamide, maleic acid, (meth) acrylonitrile, styrene, vinyl acetate, vinylidene chloride, and maleimide. Alternatively, copolymers, other materials, such as polyethylene oxide, polyvinylpyrrolidone, polyamide, polyurethane, polyester, polyether, polyethylene terephthalate, acetylcellulose, and polyvinyl butyral are exemplified.

Among them, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
Butyl (meth) acrylate, (meth) acrylic acid-2-
It contains at least one (meth) acrylic acid ester which may be substituted, such as ethylhexyl, hydroxyethyl (meth) acrylate or benzyl (meth) acrylate, and (meth) acrylic acid as a copolymer component. (Hereinafter, referred to as a “carboxyl group-containing copolymer”) is preferred.

The preferred acid value of the carboxyl group-containing polymer binder is 10 to 250 KOH.mg/g, and the preferred polystyrene equivalent weight average molecular weight (hereinafter abbreviated as Mw) is 5,000 to 1,000,000. is there. More preferably, it is 10,000 to 500,000. These polymer binders desirably have an unsaturated bond in a side chain, and include a resin obtained by reacting a compound having both an epoxy group and an unsaturated group with a carboxyl group-containing copolymer as described above.

Compounds having both an epoxy group and an unsaturated group include, for example, allyl glycidyl ether, glycidyl (meth) acrylate, α-ethyl glycidyl (meth) acrylate, glycidyl crotonate, glycidyl isocrotonate, crotonyl glycidyl ether ,
Examples thereof include aliphatic epoxy group-containing unsaturated compounds such as monoalkyl monoglycidyl itaconate, monoalkyl monoglycidyl fumarate, and monoalkyl monoglycidyl maleate, and 3,4-epoxycyclohexylmethyl (meth) acrylate. be able to.

Among them, allyl glycidyl ether, glycidyl (meth) acrylate and 3,4-epoxycyclohexylmethyl (meth) acrylate are preferred, and 3,4-epoxycyclohexylmethyl (meth) acrylate is more preferred. More preferably, those having a structural unit (monomer unit) represented by the following formula (V) are preferable.

[0075]

Embedded image (In the formula (V), Re represents a hydrogen atom or a methyl group.)

The preferred molecular weight of the above-mentioned resin having both a carboxyl group and a side chain double bond is 10,000 in Mw.
１０００1,000,000, preferably 20,000 to 5,000
00 range. Further, the side chain double bond is 1 to 50, preferably 5 to 4 per 100 main chain monomer units.
Those having 0 units introduced are preferred.

Further, the photosensitive lithographic printing plate of the present invention comprises 39
In order to improve sensitivity to laser light in a wavelength range of 0 to 430 nm, an amine compound having a pKb (dissociation constant) of 7 or less at 25 ° C. or an atomic group [N—CH ₂ ] in a molecule is contained in the photosensitive layer. It is preferred to contain an amine compound. More preferably, the pKb at 25 ° C. in the photosensitive layer is 7 or less, and the atomic group [N—C
[H ₂ ]. As the amine,
Any of aliphatic, alicyclic, and aromatic amines may be used as long as the above conditions are satisfied, and the hydrocarbon group in the amine may have a substituent. Also, it is not limited to monoamines,
Polyamines such as diamines and triamines may be used,
Further, any of primary amine, secondary amine and tertiary amine may be used. However, it is substantially selected from aliphatic amines having an optionally substituted hydrocarbon group from the viewpoint of pKb, and among them, tertiary amines are preferable. Amine p
Kb is preferably 5 or less. Further, the lower limit of pKb is preferably 3 or more. Further, the amine having the atoms in the molecule [CH ₂ -N-CH _2] is more preferred.

Specifically, butylamine, dibutylamine, tributylamine, amylamine, diamylamine, triamylamine, hexylamine, dihexylamine, trihexylamine benzylamine, dibenzylamine, tribenzylamine, triethanolamine, allylamine, Examples thereof include aliphatic amines such as diallylamine and triallylamine which may be substituted with a hydroxyl group or a phenyl group.

On the other hand, the amine compound used in the present invention is required to remain in the photosensitive layer when the photosensitive layer is coated and dried in practice, and to have no problem in handling properties such as odor. The boiling point under normal pressure is preferably 80 ° C. or higher, and the boiling point is 150 ° C. or higher and normal temperature (25 ° C.).
C) is particularly preferred. Further, triaralkylamine is preferable because it does not decrease the dispersibility of the color pigment. With that in mind, considering the availability,
For example, tribenzylamine is a particularly preferred example.

The reason for the sensitivity improvement by the addition of the amine is as follows.
It is considered as follows. (1) Generation of a radical generated by a photopolymerization initiation mechanism, or an active amino radical generated by a chain transfer reaction between an amine and a polyacrylate radical generated by photopolymerization of an acrylate monomer by the action of the radical. (2) Usually, a sensitizing dye cation and a radical generator anion generated by a sensitization process by electron transfer from a photoexcited sensitizing dye to a radical generator are deactivated by reverse electron transfer to the dye cation. From the sensitization, the amine performs electron transfer to the sensitizing dye cation to convert this cation into a neutral sensitizing dye, thereby suppressing reverse electron transfer and decomposing efficiency of the radical generator anion. To improve the radical generation effect. (3) A non-image area or an insufficiently cured photosensitive layer in an alkaline development is largely improved in the elution rate of the photosensitive layer in an alkaline developer, thereby preventing the photocurable photosensitive layer from being reduced in film thickness and improving sensitivity. Let it.

In the photosensitive layer of the photosensitive lithographic printing plate according to the second aspect of the present invention, the above-mentioned ethylenic monomer and a hexaarylbiimidazole compound (radical generator) as a photopolymerization initiation system are used.
Or dialkylaminobenzene compound (sensitizing dye) or titanocene compound (radical generator) and dialkylaminobenzene compound (sensitizing dye)
Is an essential component, but the ethylenic monomer 1
The mixing ratio of each component with respect to 00 parts by weight is preferably a hexaarylbiimidazole compound of 5 to 60 parts by weight,
More preferably, 15 to 40 parts by weight, a titanocene compound is preferably 1 to 30 parts by weight, more preferably 5 to 20 parts by weight, and a dialkylaminobenzene compound is preferably 1 to 30 parts by weight.
-30 parts by weight, more preferably 5-20 parts by weight.
The composition ratio of the radical generator to the sensitizing dye is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 3 parts by weight, based on 1 part by weight of the hexaarylbiimidazole compound. The dialkylaminobenzene compound is used in an amount of from 0.5 to 6 parts by weight, more preferably from 0.5 to 1.8 parts by weight, based on 1 part by weight of the titanocene compound.
Parts by weight.

When a polymerization accelerator (hydrogen donating compound) is contained for the purpose of improving the photopolymerization initiation ability, it is contained in an amount of 1 to 50 parts by weight based on 100 parts by weight of the ethylenic monomer component. And more preferably in the range of 10 to 40 parts by weight. When the polymer binder is contained, it is preferably contained in an amount of 50 to 500 parts by weight, more preferably 70 to 200 parts by weight, based on 100 parts by weight of the ethylenic monomer. Is more preferred. Further, in the photosensitive layer used in the present invention,
Other substances can be further contained depending on the purpose. For example, coatability improvers such as nonionic, anionic, cationic and fluorine-based surfactants; prevention of thermal polymerization of hydroquinone, p-methoxyphenol, 2,6-di-t-butyl-p-cresol and the like Colorant consisting of organic or inorganic dye / pigment (however, it is distinguished from the above-mentioned sensitizing dyes and usually has almost no compatibility with coating solvents and photosensitive layer components and has no sensitizing function) Plasticizers such as dioctyl phthalate, didodecyl phthalate, and tricresyl phosphate; sensitivity property improvers such as tertiary amines and thiols; other dye precursor defoamers, visible image-imparting agents, adhesion improvers, and development Additives such as a property improver and an ultraviolet absorber may be added.

The preferable addition amount of the above-mentioned additives is 2 parts by weight or less of a thermal polymerization inhibitor, 20 parts by weight or less of a coloring pigment, 40 parts by weight or less of a plasticizer, and 100 parts by weight of an ethylenic monomer. The range is 30 parts by weight or less of the body and 10 parts by weight or less of the surfactant. In particular, if the content of the color pigment is too large, the performance of the present invention may not be sufficiently exhibited, so that the content of the color pigment is preferably 20% by weight or less in the photosensitive composition.

The photosensitive composition described above is diluted with an appropriate solvent, applied on a support and dried to form a photosensitive layer. As the support used in the present invention, any of those conventionally used for photosensitive lithographic printing plates can be used. For example, a metal plate made of aluminum, zinc, iron, copper or an alloy thereof; chromium, Metal plate, paper, plastic film and glass plate plated or deposited with zinc, copper, nickel, aluminum, iron, etc .; paper coated with resin; paper covered with metal foil such as aluminum foil;
Examples include a plastic film subjected to a hydrophilic treatment.
Above all, a plate made of aluminum or an aluminum alloy (hereinafter sometimes referred to as an aluminum support)
Is preferably used.

The thickness of the aluminum support is usually 0.0
It is about 1 to 10 mm, preferably about 0.05 to 1 mm. The aluminum support is subjected to an anodic oxidation treatment after a surface roughening treatment at least on the photosensitive layer composition side. In addition, if necessary, a degreasing treatment, a sealing treatment, an undercoating treatment and the like may be performed. Degreasing is usually performed before the surface roughening treatment, but the degreasing treatment is a method of wiping using a solvent, dipping or steam cleaning, dipping using an alkaline aqueous solution, or neutralizing with an acid aqueous solution after spraying. It is carried out according to a conventional method such as a method, a method of dipping or spraying using a surfactant. Examples of the surface roughening method include generally known methods such as a brush polishing method, a ball polishing method, electrolytic etching, chemical etching, liquid honing, a sand blasting method, and a combination thereof, and preferably a brush polishing method and a ball polishing method. , Electrolytic etching, chemical etching,
Liquid honing.

Further, the aluminum plate subjected to the surface roughening treatment is desmutted with an acid or alkali aqueous solution as required. The desmut treatment is performed by using an acid such as sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, or chromic acid, or an aqueous solution of an alkali such as sodium hydroxide, potassium hydroxide, sodium metasilicate, sodium phosphate, sodium pyrophosphate, potassium phosphate, or sodium aluminate. It is performed according to a conventional method such as immersion or spraying. The aluminum plate thus obtained is usually subjected to anodizing treatment, and particularly preferably a method of treating with an electrolytic solution containing sulfuric acid. The method of anodizing with an electrolytic solution containing sulfuric acid is performed according to a conventionally known method, for example, a method described in JP-A-58-21894. Specifically, for example, sulfuric acid 5 to 50% by weight, preferably 15 to 30% by weight is used, and the temperature is 5 to 5% by weight.
The heating is performed at a current density of 1 to 60 A / dm ² for about 5 to 60 seconds. Further, if necessary, the surface is treated with an alkali silicate such as sodium silicate treatment or hot water, or immersed in an aqueous solution containing an aqueous polymer compound such as a resin having a cationic quaternary ammonium group or polyvinylphosphonic acid. Processing can be performed. The thickness of the aluminum support is
Usually 0.01 to 10 mm, preferably 0.05 to 1 mm
And the surface roughness is usually about 0.3 to 1.0 μm, preferably about 0.4 to 0.8 μm in terms of average roughness Ra specified in JIS B0601.

The photosensitive lithographic printing plate used in the present invention is:
Since exposure is performed by laser light at a relatively low exposure, it is also effective to leave the smut and improve the adhesiveness of the photosensitive composition as long as adverse effects such as developability and contamination during printing are not caused. The residual amount of the smut is preferably 0.3 or more, more preferably 0.3 to 0.5, and particularly preferably 0.32 to 0.45, when expressed as the reflection density of the photosensitive composition side surface. It is. When the reflectance is within the above range, printing durability is improved.

When the desmutting treatment is performed, the reflection density on the photosensitive composition side surface immediately after the surface roughening treatment step is D, and the reflection density on the photosensitive composition side surface after the anodic oxidation treatment step is E. In this case, it is preferable to control the desmutting condition so that D−E ≦ 0.1. A more preferable desmutting condition is D−E ≦ 0.08.

The reflection density is measured in a visual mode using a reflection densitometer without using a filter. The desmutting treatment, which is a condition of the present invention, depends on the alkaline aqueous solution to be used and the state of the surface roughening treatment, but is preferably 0.1 to 4% by weight and NaO having a liquid temperature of about 5 to 30 ° C.
Conditions such as immersion in an H aqueous solution for about 1 to 10 seconds are exemplified.

The photosensitive composition can be applied by a well-known method such as dip coating, coating rod, spinner coating, spray coating, roll coating and the like. The amount applied varies according to the application, the range of 0.5 to 100 g / m ² is preferable as dry coating film thickness preferably 0.5 to 5 g / m ² in the planographic printing plate. The drying temperature is, for example, about 30 to 150 ° C.
Preferably at about 40 to 110 ° C. for about 5 seconds to about 60 minutes,
Preferably, it is about 10 seconds to 30 minutes.

Further, a protective layer (oxygen blocking layer) is provided on the above-mentioned photosensitive layer in order to prevent a polymerization inhibiting action by oxygen. Specific examples thereof include polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide,
Examples include water-soluble polymers such as cellulose. Among them, those containing polyvinyl alcohol having particularly high oxygen gas barrier properties are preferable. Further, a combination of polyvinyl alcohol and polyvinyl pyrrolidone is also preferable. In this case, polyvinyl pyrrolidone is preferably used in an amount of 1 to 20 parts by weight, more preferably 3 to 15 parts by weight, based on 100 parts by weight of the polyvinyl alcohol.

The photosensitive lithographic printing plate of the present invention has a composition of 400 to 4
After forming a photosensitive layer composed of a photosensitive composition having a spectral sensitivity maximum peak other than the wavelength region of 40 nm, by providing a protective layer having a function of adjusting light transmittance on the photosensitive layer, for example, After forming a layer composed of a photosensitive composition having a spectral sensitivity maximum peak at 430 to 460 nm, a protective layer having absorption in the 430 to 500 nm region is provided on the photosensitive layer, and as a result, a wavelength of 400 to 420 nm is obtained. Has a maximum spectral sensitivity peak in the region and a wavelength of 410
You may make it satisfy | fill that the absolute sensitivity in nm is 100 microJ / cm < ² > or less.

In this case, the photosensitive composition constituting the photosensitive layer may be a composition obtained by changing the polymerization initiation system in the above photosensitive composition, specifically, a combination of the titanocene compound and the coumarin compound as described above. And the like. Coumarin compounds include, for example, those described in JP-A-6-3012.
08, JP-A-8-146605, JP-A-8-2
Coumarin dyes described in JP-A-11605, JP-A-8-129258, JP-A-8-129259 and the like can be mentioned. The coumarin-based dye is a dye having the following skeleton in its structure.

[0094]

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When a photosensitive layer is formed by using a photosensitive composition utilizing photoradical polymerization, as described above, oxygen is blocked on the photosensitive layer in order to prevent a radical polymerization inhibition effect by oxygen. Although it is preferable to provide a layer, such an oxygen blocking layer is used as a protective layer, and by adjusting the components of the protective layer, the maximum peak of the spectral sensitivity as a photosensitive lithographic printing plate is in a wavelength range of 400 to 440 nm. It is possible to adjust. As a main component of the protective layer, the same water-soluble polymer as in the above-described oxygen barrier layer may be mentioned, and it is sufficient that the protective layer contains a compound that absorbs light having the desired wavelength.

Next, a plate making method of a printing plate according to a third invention using the photosensitive composition of the present invention will be described. In the method of making a printing plate of the present invention, an image is formed by exposing the above-described photosensitive lithographic printing plate with a laser having a wavelength of 390 to 430 nm and then developing it to remove an unexposed portion.

The exposure light source applicable to the plate making method of the present invention is not particularly limited as long as it has a laser having an oscillation wavelength of 390 to 430 nm.
It is a laser having an oscillation wavelength of about 420 nm, and a wavelength near 410 nm of an indium gallium nitride semiconductor laser is particularly advantageous. The exposure is performed using a laser beam having a laser output light intensity of 1 to 100 mW, preferably 3 to 70 mW, and an oscillation wavelength of 390 to 430 nm, preferably 400 to 420 nm, for 2 to 30 μm, preferably 4 to 20 μm.
This is performed by moving the beam spot at a scanning speed of 50 to 500 m / s, preferably 100 to 400 m / s. The amount of laser light exposure (plate surface exposure) on the printing plate is 100 μJ / cm ² or less,
Preferably, image exposure is performed so as to be 50 μJ / cm ² or less. The lower limit is preferably as small as possible, but usually 1 μJ / c.
m ² or more, and practically 5 μJ / cm ² or more. The higher the scanning density of the exposure is, the higher the scanning density is, the more advantageous it is in forming a high-definition image. Therefore, the scanning density is preferably 2000 dpi or more, more preferably 4000 dpi or more.

The photosensitive lithographic printing plate of the present invention is prepared by subjecting the photosensitive composition to an aqueous developer, preferably a surfactant and an alkali component, which are mainly made of water after image exposure with such a light source. An image can be formed on a support by developing using an aqueous solution containing The aqueous solution may further contain an organic solvent and a buffer. Preferred alkali components include inorganic alkalis such as sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, sodium carbonate, potassium carbonate and sodium bicarbonate. And organic amine compounds such as trimethylamine, diethylamine, isopropylamine, n-butylamine, monoethanolamine, diethanolamine, and triethanolamine. These can be used alone or in combination. The pH of the alkali developer is usually about 9 to 14, preferably 11 to 14.
It is.

Examples of the surfactant include nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, and monoglyceride alkyl esters;
Anionic surfactants such as alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfates, alkyl sulfonates, sulfosuccinate salts and the like; amphoteric surfactants such as alkyl betaines and amino acids can be used. Further, as the organic solvent, for example, isopropyl alcohol, benzyl alcohol, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, propylene glycol, diacetone alcohol and the like can be contained as necessary.

The developing method is not particularly limited, but includes a method of immersing and oscillating in a developing solution, a method of removing a non-image portion which has been almost dissolved by a developing solution with a brush or the like, and a method of spraying the developing solution in a spray form. To remove the non-image area. The development time may be selected from the range of 5 seconds to 10 minutes as long as an unexposed portion can be sufficiently removed according to the development method.

After the development, the film may be placed on a printing plate and subjected to a hydrophilic treatment such as gum arabic as needed. If necessary, the oxygen barrier layer may be washed with water before development.

[0102]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. <Production of Aluminum Support-1> An aluminum plate having a thickness of 0.3 mm was degreased with 3% sodium hydroxide, and this was degreased in a 11.5 g / l hydrochloric acid bath at 25 ° C. and a current density of 80 A / dm ^2. Electrolytic etching for 11 seconds, washing with water, anodizing for 15 seconds in a 30% sulfuric acid bath at 30 ° C. and 11.5 A / dm ² , washing with water, and drying, followed by aluminum plate for lithographic printing plate (hereinafter referred to as “support-1”). ").).

<Production of Aluminum Support-2> An aluminum plate (thickness 0.24 mm) was degreased with a 3% by weight aqueous sodium hydroxide solution, and was then placed in a 18.0 g / liter nitric acid bath at 25 ° C. and 90 A / dm. 11 seconds at a current density of ²
Electrolytic etching was performed. Next, after desmutting with a 4.5% by weight aqueous solution of sodium hydroxide at 30 ° C. for 2 seconds,
Neutralize for 5 seconds with 10% by weight nitric acid aqueous solution at 5 ° C, wash with water,
The support was anodized in a 30% by weight sulfuric acid bath at 30 ° C. at a current density of 10 A / dm ² for 16 seconds, washed with water and dried to obtain a support. The reflection density of the support (measured with a reflection densitometer RD-918 manufactured by Macbeth) was 0.32. In this manufacturing process, AB = 0.08 (however, the reflection density of the photosensitive composition side surface immediately after the surface roughening step is A, and the reflection density of the photosensitive composition side surface immediately before the anodizing step is A). The density is B). The support thus obtained is hereinafter referred to as “support-
2 ".

Examples 1 to 14 and Comparative Examples 1 to 5 The following photosensitive composition coating solution was applied on the above-mentioned support 1 using a bar coater to a dry film thickness of 2 g / m ² and dried. (Drying condition: 170 ° C., 2 minutes). Further, the following protective layer coating solution-1 was coated and dried using a bar coater to a dry film thickness of 3 g / m ² (drying conditions: 170 ° C., 2 minutes) to produce a photosensitive lithographic printing plate. did.

[0105]

<Table 1> Protective layer coating liquid-1> 90 parts by weight of polyvinyl alcohol (GL-03 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 5 parts by weight of polyvinyl pyrrolidone (Mw = 4000) 1000 parts by weight of water

[0106]

[Table 2] Radical generator for coating solution of photosensitive composition (compounds listed in Table 1) Blended amount described in Table 1 Sensitizer (compounds described in Table 1) Blended amount described in Table 1 Polymer binder (the following compound: P-1) 45 parts by weight Ethylenic monomer 1 (the following compound: E-1) Amount shown in Table 1 Ethylenic monomer 2 (the following compound: E-2) ) 22 parts by weight Ethylenic monomer 3 (the following compound: E-3) Compounding amount shown in Table 1 Ethylenic monomer 4 (the following compound: E-4) Compounding amount shown in Table 1 2- 5 parts by weight of mercaptobenzothiazole N-phenylglycine benzyl ester The amount shown in Table 1 Tribenzylamine The amount shown in Table 1 Copper phthalocyanine pigment (visible paint) 4 parts by weight Emulgen 104P (Kao Corporation) Surfactant) 2 parts by weight S-381 ( Glass Co., Ltd. Fluorine-based surfactant) 0.3 parts by weight Disperbyk 161 (manufactured by BYK Chemie dispersant) 2 parts by weight of propylene glycol monomethyl ether acetate 400 parts by weight Cyclohexanone 740 parts by weight

The structures of the radical generator, sensitizer, polymer binder and ethylenic monomer among the components of the photosensitive composition are as follows. <Radical generator>

[0108]

Embedded image

<Sensitizer>

[0110]

Embedded image

<Polymer binder>

[0112]

Embedded image

<Ethylenic monomer>

[0114]

Embedded image

[0115]

Embedded image

The resulting photosensitive lithographic printing plate for blue-violet laser exposure was evaluated for the following items. The results are shown in Table 1. <Sensitivity evaluation> The obtained photosensitive lithographic printing plate was 50 × 60 m
m, and the light-sensitive material sample was irradiated with a xenon lamp (U1-501C, 1 kW) manufactured by Ushio Inc. as a light source, and the horizontal axis was the wavelength and the vertical axis was the vertical axis by a diffraction spectral irradiation device (RM-23 manufactured by Narumi). Irradiation was performed for 10 seconds so that the light intensity became logarithmically weak. The exposure sample was composed of 0.7% by weight of sodium carbonate and an anionic surfactant (Perex NB manufactured by Kao Corporation).
L) Development was performed by immersion in an aqueous solution containing 0.5% by weight at 28 ° C. for 30 seconds. After the development, the minimum exposure energy required for photocuring with a light beam of 410 nm was calculated from the height of the obtained cured image. The smaller the energy amount, the higher the sensitivity.

<S410 / S450> In the same manner as in the sensitivity evaluation, the minimum exposure energy S410 (μm) at a wavelength of 410 nm when the photosensitive material sample was exposed and developed.
J / cm ² ) and the minimum exposure energy S450 (μJ / cm ² ) at a wavelength of 450 nm, respectively.
The ratio (S410 / S450) was calculated. The first
The symbols A to D in the column of minimum exposure energy in the table mean the following. A: S410 / S450 is 0.03 or less B: S410 / S450 is more than 0.03 and 0.1 or less C: S410 / S450 is more than 0.1 and 0.5 or less D: S410 / S450 is 0.1 or less. Exceeding 1 The smaller the ratio, the better the safelight property under yellow light.

<Maximum Peak of Spectral Sensitivity> In the same manner as in the sensitivity evaluation, the photosensitive material sample was exposed and developed. The horizontal axis represents the exposure wavelength, and the vertical axis represents the reciprocal (sensitivity) of the minimum exposure energy at that wavelength. From the obtained spectral sensitivity curve, the wavelength showing the maximum peak of the spectral sensitivity was determined. The exposure wavelength is 3
It was changed from 50 nm to 650 nm. <Safe light under yellow light>
Cut to a size of 0 × 30 mm, and under yellow lamp illumination (under the condition of blocking light having a wavelength of about 470 nm or less) for 1 minute, 2 minutes, 5 minutes, 10 minutes, 20 minutes, 30 minutes,
After leaving for 40 minutes, development was carried out in the same manner as above, and the longest time for which the photosensitive composition did not cure when left under a yellow light was determined (evaluation up to 40 minutes).

In Table 1, A in the safelight property column
The symbols ~ D mean the following. A: 20 minutes or more B: 10 minutes or more and less than 20 minutes C: 1 minute or more and less than 10 minutes D: less than 1 minute

Example 15 In Example 12, Support-2 was used instead of Support-1.
Except for using, a photosensitive lithographic printing plate was prepared by applying and drying a photosensitive composition coating solution and a protective layer coating solution sequentially in the same manner as in Example 12, and similarly evaluated. The results are shown in Table 1.

[0121]

[Table 3]

[0122]

[Table 4]

* 1 "None" indicates that the composition is cured after standing for 1 minute. * 2 indicates that an image could not be formed at about 2000 μJ / cm ² in the exposure at 450 nm under the above conditions. * 3 “F” indicates that an image could not be formed at about 2000 μJ / cm ² in the exposure at 410 nm under the above conditions.

Incidentally, from the evaluation of the spectral sensitivity, Examples 1 to 5 were obtained.
The minimum image-forming exposure amount of the 15 photosensitive agent samples is 45
At a wavelength longer than 0 nm, a value larger than the value at 450 nm was satisfied. On the other hand, the minimum exposure amount capable of forming an image of the photosensitive agent sample of Comparative Example 1 was a value larger than the value at 450 nm at a wavelength longer than 450 nm. Further, the photosensitive layers of Examples 1 to 15 had a thickness of 350 to
In the range of 650 nm, all showed the maximum peak at 410 nm.

Example 16 A photosensitive lithographic printing plate prepared in the same manner as in Example 1 was irradiated with a laser beam output of 0.5 mW and a laser beam spot using a 410 nm blue-violet laser printing plate exposure apparatus (Cobalt 8) manufactured by Escher Grad. Image exposure was performed at a diameter of 12 μm, a scanning density of 5080 dpi, and a scanning speed of 167 m / s. Example 5 A photosensitive lithographic printing plate subjected to image exposure was prepared in Example 5.
As a result, printing in which a high quality image was formed was obtained. The plate exposure energy at this time is 30 μJ
/ Cm ² . The photosensitive lithographic printing plate manufactured in the same manner as in Examples 2 to 15 was subjected to laser light output using a 410 nm blue-violet laser printing plate exposure apparatus (Cobalt 8) manufactured by Escher Glad in the same manner as in Example 1. An image can be formed by performing image exposure at 0.5 mW, laser beam spot diameter of 12 μm, scanning density of 5080 dpi, scanning speed of 167 m / s, and developing.

[0126]

According to the present invention, the photosensitive lithographic printing plate of the present invention has 390-4
It is highly sensitive for 30 nm laser exposure, so that images and printing plates can be efficiently formed using a 390 to 430 nm laser. Furthermore, in a preferred embodiment, the safelight property under yellow light is good,
Excellent handleability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/004 503 G03F 7/004 503Z 7/027 513 7/027 513 7/028 7/028 7/029 7/029 7/038 501 7/038 501 7/11 501 7/11 501 7/20 505 7/20 505 511 511 (31) Priority claim number Japanese Patent Application No. 2000-364310 (P2000-364310) (32) Priority Date November 30, 2000 (Nov. 30, 2000) (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 2000-368412 (P2000-368412) (32) Priority date 2000 December 4, 2000 (2000.12.4) (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 2000-369415 (P2000-369415) (32) Priority date December 2000 5th (2000.12.2.5) (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 2001-16537 (P2 (001-16537) (32) Priority date January 25, 2001 (2001.1.25) (33) Priority country Japan (JP) (72) Inventor Hideaki Okamoto 1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Address Mitsubishi Chemical Corporation Yokohama Research Laboratory F-term (reference) 2H025 AA01 AB03 AC08 AD01 BC13 BC42 BC45 BC65 BC83 BC84 CA27 CA28 CA39 CA41 CC04 CC20 DA02 FA17 2H084 AA14 AA30 AA40 AE05 BB02 BB13 CC05 2H096 AA11 GA05 EA04 BA06 BB01 BB02 CA17 JA03 LA03 2H114 AA04 AA11 AA14 AA22 AA23 BA01 BA10 DA04 EA01 EA02 EA08 FA06 FA10 FA16 FA18 GA08 GA09

Claims (33)

[Claims] 1. A photosensitive lithographic printing plate having a photosensitive layer and a protective layer in this order on a support, wherein the photosensitive layer is 390
Having a maximum spectral sensitivity peak in a wavelength range of ~ 430 nm,
The photosensitive lithographic printing plate has a minimum exposure amount capable of forming an image at a wavelength of 410 nm (S410) of 100 μJ / cm ² or less, and a minimum exposure amount capable of forming an image at a wavelength of 450 nm (S450). The relationship with the minimum possible exposure amount (S410) is 0 <
S410 / S450 ≦ 0.1, wherein the photosensitive lithographic printing plate is characterized in that: 2. The image forming apparatus according to claim 1, wherein the minimum exposure amount capable of forming an image at each wavelength exceeding 450 nm and equal to or less than 650 nm is larger than the minimum exposure amount capable of forming an image at 450 nm (S450). Photosensitive lithographic printing plate. 3. A method comprising: (A) an ethylenic monomer on a support;
In a photosensitive lithographic printing plate having (B) a sensitizing dye, (C) a photosensitive layer containing a radical generator and a protective layer in this order, the photosensitive layer has a maximum spectral sensitivity peak in a wavelength range of 390 to 430 nm. Wavelength of the photosensitive lithographic printing plate
The minimum exposure for image formation (S410) at 100 nm is 100 μJ / cm ² or less, and the minimum exposure for image formation at 450 nm (S450) and the minimum exposure for image formation at 410 nm (S41).
A photosensitive lithographic printing plate wherein the relationship with 0) is 0 <S410 / S450 ≦ 0.1. 4. On a support, (A) an ethylenic monomer,
In a photosensitive lithographic printing plate having (B) a sensitizing dye, (C) a photosensitive layer containing a radical generator and a protective layer in this order, the (C) radical generator contains a hexaarylbiimidazole compound or a titanocene compound. And (B) a photosensitive lithographic printing plate wherein the sensitizing dye contains a dialkylaminobenzene compound. 5. The photosensitive lithographic printing plate according to claim 4, wherein a minimum exposure amount capable of forming an image at a wavelength of 410 nm (S410) is 100 μJ / cm ² or less. 6. The photosensitive lithographic printing plate according to claim 3, wherein (C) the radical generator contains a hexaarylbiimidazole compound, and (B) the sensitizing dye contains a dialkylaminobenzene compound. 7. The photosensitive lithographic printing plate according to claim 3, wherein (C) the radical generator contains a titanocene compound, and (B) the sensitizing dye contains a dialkylaminobenzene compound. 8. The content of the coloring pigment in the photosensitive layer is from 0 to 20.
The photosensitive lithographic printing plate according to claim 1, which is a weight. 9. The photosensitive lithographic printing plate according to claim 6, which comprises 15 to 40 parts by weight of the hexaarylbiimidazole compound based on 100 parts by weight of the ethylenic monomer. 10. The photosensitive lithographic printing plate according to claim 1, further comprising a polymer binder in the photosensitive layer. 11. The photosensitive lithographic printing plate according to claim 9, wherein the polymer binder contains a structural unit represented by the following formula (V). Embedded image (In the formula (V), Re represents a hydrogen atom or a methyl group.) 12. The photosensitive lithographic printing plate according to claim 1, further comprising a hydrogen-donating compound in the photosensitive layer. 13. The photosensitive layer further comprises a pK at 25 ° C.
5. The photosensitive lithographic printing plate according to claim 1, comprising an amine compound wherein b is 7 or less. 14. The photosensitive layer further comprises an atomic group [N—CH ₂ ].
The photosensitive lithographic printing plate according to claim 1, further comprising an amine compound having the following formula: 15. The photosensitive layer contains, as an ethylenic monomer, a urethane compound (a3) having four or more urethane bonds and four or more addition-polymerizable double bonds in one molecule. Item 6. The photosensitive lithographic printing plate according to item 1 or 4. 16. The photosensitive lithographic printing plate according to claim 15, wherein the urethane compound (a3) has a molecular weight of 600 to 200,000. 17. The photosensitive lithographic printing plate according to claim 15, wherein the urethane compound (a3) is represented by the following general formula (II). Embedded image [In the formula (II), x represents an integer of 4 to 20, y represents an integer of 0 to 15, z represents an integer of 1 to 15, Ra has a repeating unit derived from alkyleneoxy or aryleneoxy, and Rb Rb and Rc each independently represent a C1-10 alkylene group; Rd represents an organic residue having 1-10 (meth) acrylic groups; , Rb, Rc, and Rd may each independently have a substituent. ] 18. The method according to claim 18, wherein the urethane compound (a3) is (A)
As an ethylenic monomer, (a1) a compound having four or more active isocyanate groups in one molecule, and (a2) one or more hydroxyl groups and two or more addition-polymerizable double bonds in one molecule. The photosensitive lithographic printing plate according to claim 15, which is obtained by reacting a compound having the following formula: 19. The photosensitive lithographic printing plate according to claim 18, wherein (a1) the compound having four or more active isocyanate groups in one molecule has a molecular weight of 500 or more. 20. The photosensitive layer contains a phosphate compound having an acryloyloxy group or a methacryloyloxy group as the ethylenic monomer (A).
Or the photosensitive lithographic printing plate according to 4. 21. The photosensitive lithographic printing plate according to claim 3, wherein the photosensitive layer further contains a surfactant. 22. The photosensitive lithographic printing plate according to claim 1, wherein the protective layer contains polyvinyl alcohol. 23. The photosensitive lithographic printing plate according to claim 1, wherein the protective layer contains polyvinylpyrrolidone. 24. The photosensitive lithographic printing plate according to claim 2, wherein the maximum peak of the spectral sensitivity in the wavelength range of 390 to 430 nm is the maximum peak of the spectral sensitivity in the range of 350 to 650 nm. 25. The method according to claim 1, wherein the support is made by roughening a plate made of aluminum or an aluminum alloy, and the reflection density of the support is 0.3 or more. The photosensitive lithographic printing plate described in the above. 26. A support comprising a plate made of aluminum or an aluminum alloy, which is subjected to anodic oxidation treatment after roughening the plate, wherein the reflection density immediately after the roughening step is D, When the reflection density is E, D-
A photosensitive lithographic printing plate wherein E ≦ 0.1. 27. A method of making a printing plate, comprising: exposing the photosensitive lithographic printing plate according to claim 1 to an image with a laser beam having a wavelength of 390 to 430 nm, followed by developing with an aqueous developer. 28. The wavelength of the laser light is 400 to 420 n
28. The method of making a printing plate according to claim 27, wherein the range is m. 29. The scanning density of a laser beam is 4000 dp.
28. The method of making a printing plate according to claim 27, wherein i is at least i. 30. A scanning speed of a laser beam is 50 to 500.
28. The method of making a printing plate according to claim 27, wherein the printing plate speed is m / s. 31. The method of making a printing plate according to claim 27, wherein the plate surface exposure energy in the image exposure is 50 μJ / cm ² or less. 32. The method of making a printing plate according to claim 27, wherein the aqueous developer contains an alkali component. 33. The method of making a printing plate according to claim 27, wherein the aqueous developer contains a surfactant.