JP2003076010A - Original plate of planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate of a planographic printing plate capable of direct recording from digital data of a computer or the like using a heat- mode laser, not requiring heating after imagewise exposure and excellent in sensitivity in recording. SOLUTION: The original plate is characterized in that it is provided with a photosensitive layer capable of recording with a heat-mode laser and comprising (A) a photothermal conversion agent, (B) a compound having a polymerizable unsaturated group and (C) an onium salt having two or more cationic moieties in one molecule on a support. The onium salt (C) functions as a high sensitivity polymerization initiator which generates a radical under light or heat energy. The exposure wavelength of the heat-mode laser used for recording is preferably 760-1,200 nm.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an infrared laser writable lithographic printing plate precursor, and more particularly to a lithographic printing plate precursor capable of producing a lithographic printing plate excellent in recording sensitivity.

[0002]

2. Description of the Related Art The development of lasers in recent years has been remarkable, and in particular, solid-state lasers and semiconductor lasers having a light emitting region from the near infrared to the infrared region have been advanced in high output and downsizing. Therefore, these lasers are very useful as an exposure light source when directly making a plate from digital data of a computer or the like. Using an infrared laser having a light emitting region in the infrared region as an exposure light source, a negative lithographic printing plate material for infrared laser, an infrared absorber, a polymerization initiator that generates radicals by light or heat,
A lithographic printing plate material having a photosensitive layer containing a polymerizable compound.

As such a negative type image recording material, for example, a recording material composed of an infrared absorber, an acid generator, a resole resin and a novolac resin is disclosed in US Pat.
699. However, such a negative-type image recording material needs a heat treatment of heating at 140 to 200 ° C. for about 50 to 120 seconds after laser exposure for image formation. It required extensive equipment and energy.

Further, Japanese Examined Patent Publication No. 7-103171 discloses a heat treatment after imagewise exposure, which comprises a cyanine dye having a specific structure, an iodonium salt and an addition-polymerizable compound having an ethylenically unsaturated double bond. Although an unnecessary recording material is described, this image recording material has a problem that sensitivity is insufficient because polymerization is inhibited by oxygen in the air during the polymerization reaction. Furthermore, JP-A-8-10
No. 8621 describes an image recording medium containing an organic oxide or an azobisnitrile compound, which is a general-purpose thermal polymerization initiator, and a thermopolymerizable resin, and the image recording sensitivity is 200 mJ / cm ^{2 in} all cases. The above is the current situation in which the practically required high sensitivity cannot be achieved, for example, preheating treatment at the time of exposure is required to improve the sensitivity. In particular, when a heat-mode polymerization-type recording layer is used, in order to improve the sensitivity, the decomposition temperature of the initiator may be lowered and the polymerization may be caused with low energy. If the one with a low value is selected, the stability is lowered, and there is a concern that the non-image portion is likely to be stained.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to record by using a solid-state laser and a semiconductor laser that emits infrared rays, so that it is possible to record directly from digital data of a computer or the like, and after imagewise exposure. It is to obtain a lithographic printing plate precursor excellent in sensitivity at the time of recording without requiring the heat treatment of.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have paid attention to the constituent components of a negative image recording material, and as a result of intensive studies, as a result, use an onium salt of a mother nucleus having a divalent cation structure as a polymerization initiator. As a result, it was found that high sensitivity at the time of recording can be achieved, and the present invention has been completed. That is, the lithographic printing plate precursor of the present invention comprises:
(B) a compound having a polymerizable unsaturated group, and (C)
It is characterized in that it contains an onium salt having two or more cation moieties in one molecule and is provided with a photosensitive layer recordable by an infrared laser. This photosensitive layer preferably further contains (D) a binder for the purpose of improving film properties.

Although the action of the present invention is not clear, since an onium salt having two or more cation moieties in one molecule is contained as a photo or thermal polymerization initiator, a mother nucleus having a divalent or higher cation structure is formed. By adopting this, the electron density on the onium salt is lowered, and thermal decomposition is likely to be promoted, so that it is considered that high sensitivity is achieved. Further, by having a divalent or higher cation portion, when a radical species is generated at the site connecting the cation portions, it also exerts a function as a cross-linking agent, further increasing the sensitivity and improving the cross-linking structure. It is possible to improve printing durability by forming. Furthermore, by using as a photothermal conversion agent in combination with a dye such as a cyanine dye having a charge, the dye and the onium salt are easily ionically localized in the photosensitive layer, and the photothermal conversion agent and the onium salt are separated. It is considered that the localization makes it possible to more efficiently decompose the onium salt by the heat generated by the photothermal conversion agent and to realize higher sensitivity.

In the present invention, "corresponding to heat mode" means that recording by heat mode exposure is possible. The definition of heat mode exposure in the present invention will be described in detail. Hans-Joachim Tim
pe, IS & Ts NIP 15: 1999 Inte
national Conference on D
digital Printing Technology
ies. P. 209, photoexcitation of a light-absorbing substance (for example, a dye) in a photosensitive material, which undergoes a chemical or physical change, resulting in a chemical or physical change from the photoexcitation of the light-absorbing substance forming an image. It is known that there are two modes in the process up to. One is that the photoexcited light-absorbing substance is deactivated by some photochemical interaction (for example, energy transfer, electron transfer) with other reactants in the photosensitive material,
As a result, the activated reaction substance is a so-called photon mode that causes the above-mentioned chemical or physical changes necessary for image formation. Is a so-called heat mode in which the reaction substance causes the chemical or physical change necessary for image formation described above. There are also special modes such as ablation in which substances explode explosively due to the energy of light locally collected, and multiphoton absorption in which one molecule absorbs many photons at a time, but they are omitted here.

The exposure process utilizing each of the above modes is called photon mode exposure and heat mode exposure. The technical difference between photon mode exposure and heat mode exposure is whether or not the energy amount of several photons to be exposed can be added to the energy amount of the desired reaction.
For example, consider using n photons to cause a certain reaction. Since photon mode exposure utilizes photochemical interaction, one photon energy cannot be added together due to the requirement of quantum energy and momentum conservation law. That is, in order to cause some kind of reaction, the relationship of “one-photon energy amount ≧ reaction energy amount” is necessary. On the other hand, in heat mode exposure, heat is generated after photoexcitation, and light energy is converted into heat and used, so that the energy amounts can be added together. Therefore, the relationship of “energy amount of n photons ≧ energy amount of reaction” is sufficient. However, the addition of this energy amount is restricted by thermal diffusion. That is, if the next photoexcitation-deactivation process occurs and heat is generated before the heat escapes from the exposed portion (reaction point) that is currently being noticed by heat diffusion, the heat is surely accumulated and added, and the temperature of that portion rises. Leads to. However, when the next generation of heat is slow, the heat escapes and is not accumulated. In other words, in heat mode exposure, even if the total exposure energy amount is the same, the results are different when high-energy light is irradiated for a short time and when low-energy light is irradiated for a long time. Will be advantageous to the accumulation of.

Of course, in the photon mode exposure, a similar phenomenon may occur due to the influence of diffusion of the subsequent reaction species, but basically, such a phenomenon does not occur. In other words, in terms of the characteristics of the light-sensitive material, in the photon mode, the intrinsic sensitivity of the light-sensitive material (energy for reaction necessary for image formation) with respect to the exposure power density (w / cm ² ) (= energy density per unit time) However, in the heat mode, the intrinsic sensitivity of the photosensitive material increases with the exposure power density. Therefore, when the exposure time is fixed so that the productivity required for practical use as an image recording material is fixed, when comparing each mode, the photon mode exposure usually has a high sensitivity of about 0.1 mJ / cm ^2. Can be achieved, but the reaction takes place at any low light exposure,
The problem of low-exposure fog in the unexposed area is likely to occur. On the other hand, in the heat mode exposure, the reaction does not occur unless the exposure amount is a certain amount or more, and about 50 mJ / cm ² is usually required in relation to the thermal stability of the photosensitive material, but the problem of low exposure fog occurs. Is avoided. In the heat mode exposure, the exposure power density on the plate surface of the photosensitive material is practically 500.
0 w / cm ² or more is required, preferably 10,000
w / cm ² or more is required. However, although not described here in detail, it is not preferable to use a high power density laser of 5.0 × 10 ⁵ w / cm ² or more because ablation occurs and the light source is contaminated.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. First, each component used in the photosensitive layer of the lithographic printing plate precursor according to the invention will be described.

[(C) Onium salt having two or more cation moieties in one molecule] As a characteristic component in the photosensitive layer of the lithographic printing plate precursor according to the invention, (C) two cation moieties in one molecule. An onium salt having the above (hereinafter, appropriately referred to as a divalent onium salt) can be given. In the present invention, an onium salt having two or more cation moieties in one molecule is 2
It refers to a compound in which one or more cation moieties are linked by a covalent bond. The divalent onium salt in the present invention is a photo- or heat-polymerizable initiator, that is, a radical is generated by the energy of light or heat energy, or both of them, and initiates the polymerization of a compound having a polymerizable unsaturated group, Has the function of promoting. Examples of onium salts having two or more cation moieties used in the present invention include diazonium salts, iodonium salts, sulfonium salts, ammonium salts, and phosphonium salts. From the aspect of sensitivity, diazonium salt,
Iodonium salts and sulfonium salts are preferable, and iodonium salts and sulfonium salts are more preferable from the viewpoint of stability. As the iodonium salt preferably used in the present invention, any divalent or higher valent iodonium salt can be arbitrarily selected and used unless there is a particular problem with other physical properties. JP-A No. 11-153870 Gazette, J. Or
g. Chem 57, 6810-6814 (1992).
Year)), and from the viewpoint of sensitivity, most preferred are those having a structure represented by the following general formula (I).

[0013]

[Chemical 1]

In the general formula (I), Ar ¹ and Ar ² each independently represent an aromatic hydrocarbon having 6 to 18 carbon atoms, or a heterocycle containing a hetero atom selected from nitrogen, oxygen and sulfur. Represent These may have a substituent, and examples of the substituent include a halogen atom, an alkoxy group, a cyano group, a carbonyl group, an amino group, an amide group, a sulfonyl group, an alkyl group, an aryl group, an alkenyl group and a hydroxyl group. To be R ^{1 to} R ⁴ are each independently a hydrogen atom, a halogen atom, an alkoxy group, a cyano group, a carbonyl group, an amino group, an amide group, a sulfonyl group, an alkyl group, an aryl group, an alkenyl group, or a hydroxyl group. Represent X ⁻ represents a monovalent anion.

Further, the sulfonium salt preferably used in the present invention is a divalent or higher valent sulfonium salt,
Although it can be used, JP-A-11-80118,
J. Org. Chem 1992, 57, 6810-6.
The sulfonium described in 814 is preferable, and the most preferable example from the viewpoint of sensitivity is that represented by the following general formula (II).

[0016]

[Chemical 2]

In the general formula (II), Ar ³ , Ar ⁴ and Ar
^5, Ar ⁶ independently of one another are C 6-18 aromatic hydrocarbon, or represents nitrogen, oxygen, a heterocyclic ring containing a heteroatom selected from sulfur. These may have a substituent, and as the substituent, a halogen atom, an alkoxy group,
Examples thereof include cyano group, carbonyl group, amino group, amide group, sulfonyl group, alkyl group, aryl group, alkenyl group and hydroxyl group. R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, an alkoxy group, a cyano group, a carbonyl group, an amino group, an amide group, a sulfonyl group, an alkyl group, an aryl group, an alkenyl group or a hydroxyl group. X ^-
Represents a monovalent anion.

The counter anion of the onium salt of the present invention can be used as long as a monovalent anion, preferably _{^{PF 6 -, BF 4 -,}} ClO 4 -, a sulfonate anion, carboxylate anion, saccharin conjugate Represents a base or a halogen anion, more preferably PF ₆ ⁻ , BF ₄ ⁻ , ClO ₄ ⁻ , a sulfonate anion, or a carboxylate anion from the viewpoint of sensitivity and stability, and most preferably a sulfonate anion or a carboxylate anion. Of these, a carboxylic acid having a COCOO ⁻ structure is preferable. Two or more counter anions X ⁻ for the divalent onium salt according to the present invention may be the same as or different from each other. From the viewpoint of ease of production, the same is preferable. In the present invention, these onium salts function not as an acid generator but as a radical polymerization initiator.

The divalent onium salt can be synthesized by a known method. For example, divalent sulfonium salts are described in Chem. Mater. 1990, 2,732-7
It can be synthesized by the method described in 37. Further, the divalent iodonium salt is described in J. Org. Chem 199
2,57,6810-6814, or J. Am. Ch
em. Soc. 1990, 112, 6438-6439
It can be synthesized by the method described in. Further, as a divalent onium salt in the present invention, JP-A-4-2306
Copolymers of iodonium salts or sulfonium salts described in Japanese Patent No. 45 can also be used.

The following (C) is preferably used in the present invention.
Preferred specific examples of the divalent onium salt are shown below, but the present invention is not limited thereto. In the following divalent onium salts, [Exemplified Compound (I-1) to Exemplified Compound (I-51)] are iodonium salt compounds, and [Exemplified Compound (S-1) to Exemplified Compound (S-40)] are It is a sulfonium salt-based compound.

[0021]

[Chemical 3]

[0022]

[Chemical 4]

[0023]

[Chemical 5]

[0024]

[Chemical 6]

[0025]

[Chemical 7]

[0026]

[Chemical 8]

[0027]

[Chemical 9]

[0028]

[Chemical 10]

[0029]

[Chemical 11]

[0030]

[Chemical 12]

[0031]

[Chemical 13]

These divalent onium salts may be used alone or in combination of two or more. The preferred addition amount of the divalent onium salt is 1 to 4 in the total solid content of the photosensitive layer.
It is 5% by weight, more preferably 3-40% by weight, most preferably 5-30% by weight. If the amount added is less than 1%,
Low sensitivity makes image formation difficult. On the other hand, when it is 45% or more, the alkali developability deteriorates.

In the photosensitive layer according to the present invention, in addition to the above-mentioned (C) divalent onium salt, a known photo- or thermal-polymerization initiator, typically a photo-initiator, as long as the effects of the present invention are not impaired. A monovalent onium salt or the like can also be used in combination. As such a polymerization initiator, paragraph number [00] of Japanese Patent Application No. 2000-132478 proposed by the present inventors has been proposed.
34] to [0040] II) onium salts described as polymerization initiators, and various polymerization initiations including the onium salts described in JP-A-9-34110, paragraphs [0063] to [0064] as initiators. Agents can be used.

The polymerization initiator used in the present invention is
The maximum absorption wavelength is preferably 400 nm or less,
Further, it is preferably 360 nm or less. By thus setting the absorption wavelength in the ultraviolet region, the image recording material can be handled under a white light.

The known (other than divalent onium salt) polymerization initiator that can be used in combination can be added in a proportion of 0 to 30% by weight based on the total solid content of the photosensitive layer. The addition amount is preferably about 0 to 50% by weight with respect to the divalent onium salt (C).

[(A) Photothermal Conversion Agent] In the present invention, the photothermal conversion agent contained in the photosensitive layer is a substance which absorbs the light energy irradiation ray used for recording and generates heat, particularly in the absorption wavelength range. It can be used without limitation. The preferred photothermal conversion agent used in the present invention has a wavelength of 760 nm from the viewpoint of compatibility with easily available high-power lasers.
To an infrared absorbing dye or pigment having an absorption maximum at 1200 nm.

As the dye, commercially available dyes and known dyes described in documents such as "Handbook of Dyes" (edited by the Society of Synthetic Organic Chemistry, published in 1970) can be used. Specifically, azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes, oxonol dyes. , Dyes such as diimonium dyes, aminium dyes, and croconium dyes.

Preferred dyes include, for example, JP-A-5
Cyanine dyes described in JP-A No. 8-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-78787, and JP-A-58-1736.
96, JP-A-58-181690, JP-A-58-1
Methine dyes described in Japanese Patent Application No. 94595, JP-A-Sho 5
8-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59-73996,
Naphthoquinone dyes described in JP-A-60-52940, JP-A-60-63744 and the like, JP-A-58-1
Squarylium dyes described in No. 12792,
Examples thereof include cyanine dyes described in British Patent 434,875.

The near-infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used, and the substituted arylbenzo (thio) described in US Pat. No. 3,881,924 is also used. Pyrylium salt, JP-A-57-142645
Trimethine thiapyrylium salt described in U.S. Pat. No. 4,327,169, JP-A Nos. 58-181051, 58-220143, 59-41363 and 59-11363.
-84248, 59-84249, 59-14
Nos. 6063 and 59-146061, pyranium compounds described in JP-A-59-216146, pentamethine thiopyrylium salts described in U.S. Pat. No. 4,283,475, and the like. Fair 5-13
The pyrylium compounds disclosed in Nos. 514 and 5-19702 are also preferably used.

Another preferred example of the dye is represented by the formula (I) in US Pat. No. 4,756,993:
The near infrared absorbing dye described as (II) can be mentioned.

Among these dyes, particularly preferred are cyanine dyes, phthalocyanine dyes, oxonol dyes, squarylium dyes, pyrylium salts, thiopyrylium dyes, and nickel thiolate complexes. Further, the dyes represented by the following general formulas (a) to (e) are preferable because they have excellent photothermal conversion efficiency, and the cyanine dye represented by the following general formula (a) particularly constitutes the photosensitive layer according to the present invention. It is most preferable because it gives high polymerization activity when used in the composition, and is excellent in stability and economy.

[0042]

[Chemical 14]

In the general formula (a), X ¹ represents a hydrogen atom, a halogen atom, —NAr ³ ₂ , X ² —L ¹ or a group shown below. Here, Ar ³ is a halogen atom, an alkoxy group, a carbonyl group, a sulfonyl group, an amide group, a hydroxyl group,
Or, represents an aromatic group which may be substituted with an alkyl group, X ² represents an oxygen atom or a sulfur atom, L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, or an aromatic group having a hetero atom. A hydrocarbon group having 1 to 12 carbon atoms including a ring and a hetero atom is shown. Here, the hetero atom means N, S,
O, a halogen atom and Se are shown.

[0044]

[Chemical 15]

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

Ar ¹ and Ar ^{2, which} may be the same or different, each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Examples of preferable substituents include a hydrocarbon group having 12 or less carbon atoms, a halogen atom, and an alkoxy group having 12 or less carbon atoms. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ^{4, which} may be the same or different, each represents a hydrocarbon group having 20 or less carbon atoms, which may have a substituent. As a preferable substituent, an alkoxy group having 12 or less carbon atoms,
Examples thereof include a carboxyl group and a sulfo group. R ⁵ , R ⁶ , R
⁷ and R ⁸ may be the same or different,
It represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, hydrogen atom is preferable. Za ^- represents a counter anion. However, when any of R ^{1 to} R ⁸ is substituted with a sulfo group, Za ⁻ is not necessary. Preferred Za ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, from the storage stability of the photosensitive layer coating solution.
And a sulfonate ion, particularly preferably a perchlorate ion, a hexafluorophosphate ion, and an arylsulfonate ion.

In the present invention, specific examples of the cyanine dye represented by the general formula (a) which can be preferably used include those shown below and Japanese Patent Application No. 11-31062.
Paragraph numbers [0017] to [0019] of the specification No. 3 and paragraph number [001] of the specification of Japanese Patent Application No. 2000-224031.
2] to [0038], and those described in paragraph Nos. [0012] to [0023] of Japanese Patent Application No. 2000-211147. Among the cyanine dyes represented by formula (a), those in which X ¹ is —NAr ³ ₂ are most preferable from the viewpoint of sensitivity.

[0048]

[Chemical 16]

[0049]

[Chemical 17]

[0050]

[Chemical 18]

[0051]

[Chemical 19]

[0052]

[Chemical 20]

In the above general formula (b), L represents a methine chain having 7 or more conjugated carbon atoms, and the methine chain may have a substituent, and the substituents are bonded to each other to form a ring structure. You may have. Zb ⁺ represents a counter cation. Preferred counter cations include ammonium, iodonium, sulfonium, phosphonium, pyridinium, alkali metal cations (Ni ⁺ , K ⁺ , Li ⁺ ) and the like. R ⁹ ~ R
¹⁴ and R ^{15 to} R ²⁰ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, a carbonyl group, a thio group, a sulfonyl group, a sulfinyl group, an oxy group, or an amino group. Represents a substituent selected from the above, or a substituent in which two or three of them are combined, and may be bonded to each other to form a ring structure. Here, in the general formula (b), L represents a methine chain having 7 conjugated carbon atoms, and R ^{9 to} R ¹⁴ and R ^{15 to} R ²⁰ all represent hydrogen atoms, which are easily available. It is preferable from the viewpoint of the effect.

In the present invention, specific examples of the dye represented by formula (b) which can be preferably used include the followings.

[0055]

[Chemical 21]

[0056]

[Chemical formula 22]

In the general formula (c), Y ³ and Y ⁴ each represent an oxygen atom, a sulfur atom, a selenium atom or a tellurium atom. M represents a methine chain having a conjugated carbon number of 5 or more.
R ^{21 to} R ²⁴ and R ^{25 to} R ²⁸ may be the same or different and each is a hydrogen atom, a halogen atom, a cyano group, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, a carbonyl group or a thiol group. Represents a group, a sulfonyl group, a sulfinyl group, an oxy group, or an amino group. Also, in the formula Z
a ^- represents a counter anion, Za in the general formula (1) ^-
Is synonymous with.

Specific examples of the dye represented by the general formula (c) which can be preferably used in the invention include the followings.

[0059]

[Chemical formula 23]

[0060]

[Chemical formula 24]

In the general formula (d), R²⁹Through R³¹Is each
Independently, a hydrogen atom, an alkyl group, or an aryl group
Show. R³³And R³⁴Are each independently an alkyl group or a substituent
An oxy group or a halogen atom is shown. n and m are
Each independently represents an integer of 0 to 4. R²⁹And R³⁰, Or
R³¹And R³²May combine with each other to form a ring, or
R²⁹And / or R³⁰Is R³³And again R³¹and/
Or R³²Is R³⁴May form a ring by combining with
And R³³Or R³⁴If there are multiple ³³One another
R is R³⁴They may combine with each other to form a ring.
X²And X³Are each independently a hydrogen atom, an alkyl group, or
Or is an aryl group, X²And X³At least one of
Represents a hydrogen atom or an alkyl group. Q has a substituent
Optionally a trimethine group or a pentamethine group
Or may form a ring structure with a divalent organic group. Z
c^-Represents a counter anion, and Za in the general formula (a) is^-
Is synonymous with.

In the present invention, specific examples of the dye represented by formula (d) which can be preferably used include the followings.

[0063]

[Chemical 25]

[0064]

[Chemical formula 26]

In the general formula (e), R ^{35 to} R ⁵⁰ are each independently a hydrogen atom which may have a substituent, a halogen atom, a cyano group, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, A hydroxyl group, a carbonyl group, a thio group, a sulfonyl group, a sulfinyl group, an oxy group, an amino group, and an onium salt structure are shown. M represents two hydrogen atoms or a metal atom, a halometal group or an oxymetal group, and the metal atom contained therein is IA, IIA or II in the periodic table.
IB, IVB group atoms, first, second and third period transition metals,
Examples of the lanthanoid element include copper, magnesium, iron, zinc, cobalt, aluminum, titanium and vanadium.

Specific examples of the dye represented by the general formula (e) which can be preferably used in the present invention include the followings.

[0067]

[Chemical 27]

Examples of the pigment used as the light-heat converting agent in the present invention include commercially available pigments and color index (CI) handbooks, "Latest pigment handbook" (edited by Japan Pigment Technology Association, 1977), "Latest Pigment". Applied Technology "(CMC
Published in 1986), "Printing Ink Technology" published by CMC, published in 1984).

The types of pigments include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments,
Blue pigment, green pigment, fluorescent pigment, metal powder pigment, etc.
Polymer bound dyes may be mentioned. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments,
Perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, dyed lake pigments,
Azine pigment, nitroso pigment, nitro pigment, natural pigment, fluorescent pigment, inorganic pigment, carbon black and the like can be used.
Preferred among these pigments is carbon black.

These pigments may be used without surface treatment or may be used after surface treatment. The surface treatment method includes a method of surface-coating a resin or wax, a method of attaching a surfactant, a method of binding a reactive substance (for example, a silane coupling agent, an epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The above surface treatment method is "property and application of metal soap" (Koushobo),
It is described in "Printing Ink Technology" (CMC Publishing, 1984) and "Latest Pigment Application Technology" (CMC Publishing, 1986).

The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably 0.1 μm to 1 μm.
It is preferably in the range of. Particle size of pigment is 0.01μ
When it is less than m, it is not preferable from the viewpoint of stability of the dispersion in the coating liquid for the image-sensitive layer, and when it exceeds 10 μm, it is not preferable from the viewpoint of uniformity of the image-sensitive layer.

As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, etc. can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill and a pressure kneader. For details, see "Latest Pigment Application Technology" (CMC Publishing, 1
986).

In the present invention, these photothermal conversion agents may be used alone or in combination of two or more, but from the viewpoint of sensitivity, the dye represented by the general formula (a) is used. It is preferable to use, especially X ¹ is —NAr ³
Those represented by ₂ are most preferable.

These photothermal conversion agents may be added to the same layer as the other components, or may be added to another layer provided, but the photosensitive layer of the negative lithographic printing plate precursor is prepared. (Film formation)
At this time, the optical density at the absorption maximum in the wavelength range of 760 nm to 1200 nm of the photosensitive layer is preferably in the range of 0.1 to 3.0. If it is out of this range, the sensitivity tends to be low. Since the optical density is determined by the amount of the infrared absorber added and the thickness of the photosensitive layer, the predetermined optical density can be obtained by controlling the conditions of both. The optical density of the photosensitive layer can be measured by a conventional method. As a measuring method, for example, a transparent or white support, a coating amount after drying to form a photosensitive layer having a thickness appropriately determined in the range necessary for a lithographic printing plate, with a transmission type optical densitometer Examples thereof include a measuring method and a method of forming a photosensitive layer on a reflective support such as aluminum and measuring the reflection density.

[(B) Compound Having Polymerizable Unsaturated Group] The compound having a polymerizable unsaturated group used in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond. And preferably selected from compounds having at least one, and preferably two or more terminal ethylenically unsaturated bonds. Such a compound group is widely known in the industrial field, and these compounds can be used in the invention without particular limitation. These are, for example, monomers, prepolymers, ie dimers,
Those having chemical forms such as trimers and oligomers, or a mixture thereof and a copolymer thereof are included. Examples of the monomers and copolymers thereof include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), and their esters and amides. As the ester, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyhydric amine compound are used. Further, a hydroxyl group, an amino group, an unsaturated carboxylic acid ester having a nucleophilic substituent such as a mercapto group, an amide and a monofunctional or polyfunctional isocyanate, an addition reaction product of an epoxy,
A dehydration condensation reaction product with a monofunctional or polyfunctional carboxylic acid is also preferably used.

Further, unsaturated carboxylic acid esters, amides and monofunctional or polyfunctional alcohols having an electrophilic substituent such as an isocyanato group or an epoxy group,
Addition reaction products with amines and thiols, halogen groups,
A substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a tosyloxy group with a monofunctional or polyfunctional alcohol, amine, or thiol is also suitable. Further, as another example, it is also possible to use a compound group in which unsaturated phosphonic acid, styrene, vinyl ether or the like is substituted for the above unsaturated carboxylic acid.

Specific examples of the monomer of the ester 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 tetraacryl chloride, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol. Tetra acrylate, so Bito one Le pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

As the methacrylic acid ester, tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol. Dimethacrylate, hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3- Methacryloxy-2-hi Rokishipuropokishi) phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

As the itaconic acid ester, ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, sorbitol tetritaconate and the like.

As the crotonic acid ester, ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate,
Examples include sorbitol tetradicrotonate. Examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate and sorbitol tetramaleate.

Examples of other esters include, for example, JP-B-46-27926, JP-B-51-47334, aliphatic alcohol esters described in JP-A-57-196231, JP-A-59-5240 and JP-A-59-5240. 59-524
1, those having an aromatic skeleton described in JP-A-2-226149, and those containing an amino group described in JP-A-1-165613 are also preferably used. Furthermore, the above-mentioned ester monomers can also be used as a mixture.

Specific examples of the amide monomer of an aliphatic polyvalent amine compound and an unsaturated carboxylic acid include methylenebis-acrylamide, methylenebis-methacrylamide, 1,6-hexamethylenebis-acrylamide, 1,6- Hexamethylene bis-methacrylamide,
Examples include diethylenetriamine tris acrylamide, xylylene bis acrylamide, and xylylene bis methacrylamide. Examples of other preferable amide-based monomers include those having a cyclohexylene structure described in JP-B No. 54-21726.

Further, urethane type addition-polymerizable compounds produced by addition reaction of isocyanate and hydroxyl group are also suitable, and specific examples thereof include, for example, Japanese Examined Patent Publication No.
Two or more in one molecule obtained by adding a vinyl monomer having a hydroxyl group represented by the following formula to a polyisocyanate compound having two or more isocyanate groups in one molecule described in JP-A-8-41708. Examples thereof include vinyl urethane compounds containing a polymerizable vinyl group.

CH ₂ ═C (R) COOCH ₂ CH (R ′) OH In the above formula, R and R ′ represent H or CH ₃ .

Further, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293 and JP-B-2-16765, and JP-B-58-
49860, Japanese Patent Publication No. 56-17654, Japanese Patent Publication No. 62
The urethane compounds having an ethylene oxide skeleton described in JP-B-39417 and JP-B-62-39418 are also suitable.

Further, by using addition-polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909 and JP-A-1-105238. Can provide a photosensitive composition having a very high exposure speed.

Another example is JP-A-48-641.
No. 83, Japanese Patent Publication No. 49-43191, Japanese Patent Publication No. 52-30
Polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid as described in Japanese Patent No. 490 and each publication can be given. Also,
JP-B-46-43946, JP-B1-40337,
Specific unsaturated compounds described in JP-B-1-40336,
The vinylphosphonic acid compounds described in JP-A-2-25493 can also be used. In some cases, the structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, the Japan Adhesive Association magazine, vol. 20, No. 7, pages 300-308 (1
Those introduced as photo-curable monomers and oligomers in (984) can also be used.

Regarding these addition-polymerizable compounds, what structure is used, whether they are used alone or in combination,
The details of the usage method, such as the addition amount, can be arbitrarily set according to the performance design of the final photosensitive material. For example, it is selected from the following viewpoints. From the viewpoint of photosensitivity, a structure having a large content of unsaturated groups per molecule is preferable, and in many cases, bifunctional or higher functional groups are preferable. Further, in order to increase the strength of the image portion, that is, the cured film, it is preferable that the functional group has three or more functional groups, and further, different functional numbers and different polymerizable groups (for example, acrylic acid ester, methacrylic acid ester, styrene-based compound, vinyl ether-based compound). A method of controlling both photosensitivity and strength by using a compound) together is also effective. A compound having a large molecular weight or a compound having a high hydrophobicity is excellent in the photosensitizing speed and the film strength, but it may not be preferable in terms of the developing speed and the precipitation in the developing solution.

In addition, the compatibility with other components (eg, binder polymer, initiator, colorant, etc.) and dispersibility in the composition constituting the photosensitive layer, the selection of addition polymerization compounds.
The usage is an important factor, and for example, the compatibility may be improved by using a low-purity compound or by using two or more kinds in combination. Further, in the case of a lithographic printing plate precursor, a specific structure may be selected for the purpose of improving the adhesion of a support, an overcoat layer and the like, which will be described later. Regarding the compounding ratio of the addition-polymerizable compound in the composition for forming a photosensitive layer (hereinafter, also appropriately referred to as a photosensitive composition), the larger the ratio, the more advantageous in terms of sensitivity. Separation may occur, problems in the manufacturing process due to the tackiness of the composition for forming the photosensitive layer (for example, transfer of the photosensitive material component, manufacturing defects due to tackiness), or when using a lithographic printing plate precursor, Can cause problems such as precipitation of From these viewpoints, the preferable compounding ratio is often 5 to 80% by weight, preferably 25 to 75% by weight, based on all the components of the composition. These may be used alone or in combination of two or more. In addition, the method of using the addition-polymerizable compound, the degree of polymerization inhibition with respect to oxygen, resolution, fogging, refractive index change, surface tackiness, etc., an appropriate structure, formulation, and addition amount can be arbitrarily selected. Depending on the case, a layer constitution / coating method such as undercoating or topcoating can be carried out.

[(D) Binder] In the lithographic printing plate precursor according to the invention, in the photosensitive layer, for the purpose of improving film property,
It is preferable to add a binder polymer to the photosensitive layer. The binder used here is preferably a linear organic high molecular polymer which is insoluble in water and soluble in an aqueous alkali solution. As such a "linear organic high molecular polymer",
Any known polymer can be selected and used, but a water-soluble or weak alkaline water-soluble or swellable linear organic polymer which enables water development or weak alkaline water development is preferable. To be selected. The linear organic high molecular polymer is not only used as a film forming agent for the composition,
It is selected and used according to the application as water, weak alkaline water or organic solvent developer. For example, when a water-soluble organic polymer is used, water development becomes possible. Examples of such a linear organic high molecular polymer include addition polymers having a carboxylic acid group in the side chain, for example, JP-A-59-44615, JP-B-54-34327, JP-B-58-12577, and JP-B-58. 54-25957, JP-A-54-92723,
Those described in JP-A-59-53836 and JP-A-59-71048, that is, methacrylic acid copolymers, acrylic acid copolymers, itaconic acid copolymers, crotonic acid copolymers, maleic acid Examples thereof include copolymers and partially esterified maleic acid copolymers. Similarly, there is an acidic cellulose derivative having a carboxylic acid group in its side chain. In addition to these, addition polymers having 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 monomer] copolymer and [allyl (meth) acrylate / (meth) acrylic acid / Other addition polymerizable vinyl monomer if necessary] copolymer is
It is suitable because it has an excellent balance of film strength, sensitivity, and developability.

Further, Japanese Patent Publication No. 7-2004, Japanese Patent Publication No. 7-2004
-120041, Japanese Patent Publication No. 7-120042, Japanese Patent Publication No. 8-12424, Japanese Patent Laid-Open No. 63-287944, Japanese Patent Laid-Open No. 63-287947, Japanese Patent Laid-Open No. 1-271741,
The urethane group binder polymer containing an acid group, which is described in Japanese Patent Application No. 10-116232 and the like, is very excellent in strength and is advantageous in terms of printing durability and suitability for low exposure.
Further, the binder having an amide group described in JP-A No. 11-171907 is suitable because it has both excellent developability and film strength.

In addition to these, polyvinylpyrrolidone and polyethylene oxide are useful as water-soluble linear organic polymers. In addition, alcohol-soluble nylon and polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin are also useful for increasing the strength of the cured film. These linear organic high molecular weight polymers can be mixed in any amount in the entire composition. However, when it exceeds 90% by weight, favorable results are not obtained in terms of the strength of the formed image. Preferably 30-85
% By weight. The weight ratio of the compound having a photopolymerizable ethylenically unsaturated double bond to the linear organic polymer is preferably in the range of 1/9 to 7/3.

As the binder polymer according to the present invention, one which is substantially insoluble in water and soluble in an alkaline aqueous solution is used. For this reason, it is possible to use no environmentally unfavorable organic solvent as the developer, or to limit the amount to be used to a very small amount. The acid value (the acid content per 1 g of the polymer is represented by a chemical equivalent number) and the molecular weight of such a binder polymer are appropriately selected from the viewpoints of image strength and developability. A preferred acid value is 0.4 to 3.0 meq / g and a preferred molecular weight is in the range of 3,000 to 500,000, and more preferably an acid value of 0.6 to 2.0 is in the range of 10,000 to 300,000. Is.

[(E) Other Components] The photosensitive layer of the lithographic printing plate precursor according to the invention may further contain other components suitable for the intended use, the production method and the like. Less than,
The preferred additives will be exemplified. (E-1) Cosensitizer The sensitivity can be further improved by using a certain additive (hereinafter referred to as a cosensitizer). Although their mechanism of action is not clear, it is thought that most of them are based on the following chemical processes. That is, the co-sensitizer reacts with various intermediate active species (radicals and cations) generated in the process of the photopolymerization initiated by the thermal polymerization initiator and the subsequent addition polymerization reaction to generate a new active radical. It is presumed to do. These are, to a large extent, (a) a substance that can be reduced to generate an active radical, (b) a substance that can be oxidized to generate an active radical, and (c) a radical having a higher activity that reacts with a less active radical. The compound can be classified into a compound that acts as a chain transfer agent or a compound that is converted into a compound, but there is often no consensus as to which of these individual compounds belong.

(A) Compound which is reduced to produce an active radical Compound having a carbon-halogen bond: It is considered that the carbon-halogen bond is reductively cleaved to generate an active radical. Specifically, for example, trihalomethyl-s-triazines and trihalomethyloxadiazoles can be preferably used. Compound having nitrogen-nitrogen bond: It is considered that the nitrogen-nitrogen bond is reductively cleaved to generate an active radical. Specifically, hexaarylbiimidazoles and the like are preferably used. Compound having oxygen-oxygen bond: It is considered that an oxygen-oxygen bond is reductively cleaved to generate an active radical. Specifically, for example, organic peroxides and the like are preferably used. Onium compound: Reductively carbon-hetero bond or oxygen-
It is considered that the nitrogen bond is cleaved to generate an active radical. Specifically, for example, diaryliodonium salts,
Triarylsulfonium salts, N-alkoxypyridinium (azinium) salts and the like are preferably used. Ferrocene, iron arene complexes: An active radical can be reductively generated.

(B) Compound that oxidizes to generate an active radical Alkylate complex: It is considered that an active radical is generated by the oxidative cleavage of a carbon-hetero bond. Specifically, for example, triarylalkyl borates are preferably used. Alkylamine compound: It is considered that the C—X bond on the carbon adjacent to the nitrogen is cleaved by oxidation to generate an active radical. As X, a hydrogen atom, a carboxyl group, a trimethylsilyl group, a benzyl group and the like are preferable.
Specific examples include ethanolamines, N-phenylglycines, N-trimethylsilylmethylanilines, and the like. Sulfur-containing and tin-containing compounds: The above amines in which the nitrogen atom is replaced with a sulfur atom or a tin atom can generate an active radical by the same action. It is also known that a compound having an S-S bond is sensitized by cleavage of S-S.

Α-Substituted methylcarbonyl compound: An active radical can be generated by the cleavage of the carbonyl-α carbon bond by oxidation. Further, the one in which carbonyl is converted to oxime ether also exhibits the same action. In particular,
2-alkyl-1- [4- (alkylthio) phenyl]
Examples thereof include -2-morpholinopronone-1 and oxime ethers obtained by reacting these with hydroxyamines and then etherifying N-OH. Sulfinates: An active radical can be reductively generated. Specific examples thereof include sodium arylsulfin and the like.

(C) Compounds that react with radicals to be converted into highly active radicals or act as chain transfer agents: For example, compounds having SH, PH, SiH, and GeH in the molecule are used. These can donate hydrogen to a radical species having low activity to generate a radical, or can generate a radical by deprotonating after being oxidized. Specific examples include 2-mercaptobenzimidazoles.

More specific examples of these co-sensitizers are described, for example, in JP-A-9-236913 as additives for the purpose of improving sensitivity, and they are used in the present invention. Can also be applied.

(E-2) Polymerization Inhibitor In the present invention, in addition to the above basic components, a compound having an ethylenically unsaturated double bond which is polymerizable during the production or storage of the photosensitive composition is unnecessary. It is desirable to add a small amount of a thermal polymerization inhibitor to prevent such thermal polymerization. Suitable thermal polymerization inhibitors include hydroquinone, p
-Methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4- Methyl-
6-t-butylphenol), N-nitrosophenylhydroxyamine primary cerium salt and the like. The amount of the thermal polymerization inhibitor added is about 0.01 based on the weight of the entire composition.
Weight percent to about 5 weight percent is preferred. If necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide is added to prevent polymerization inhibition by oxygen to prepare a lithographic printing plate precursor. It may be unevenly distributed on the surface of the photosensitive layer during the drying process. The amount of the higher fatty acid derivative added is about 0.5% by weight to about 10% by weight of the total composition.
Weight percent is preferred.

(E-3) Colorant etc. Further, a dye or a pigment may be added for the purpose of coloring the photosensitive layer. This makes it possible to improve the so-called plate inspection property such as the visibility as a printing plate after plate making and the suitability for an image density measuring machine. As a colorant, many dyes cause a decrease in the sensitivity of the photopolymerization type photosensitive layer, so that a pigment is particularly preferably used as the colorant. Specific examples include phthalocyanine pigments, azo pigments, carbon black, pigments such as titanium oxide, ethyl violet,
There are dyes such as crystal violet, azo dyes, anthraquinone dyes, and cyanine dyes. The amount of dye and pigment added is about 0.5% to about 5% by weight of the total composition.
Is preferred.

(E-4) Other Additives Further, in the photosensitive layer according to the present invention, in order to improve the physical properties of the cured film, an inorganic filler, other plasticizer, and ink receptivity on the surface of the photosensitive layer are added. You may add well-known additives, such as an oil sensitizer which can be improved.

Examples of the plasticizer include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, and triacetyl glycerin. In this case, 10% by weight or less can be added to the total weight of the compound having an ethylenically unsaturated double bond and the binder.

Further, for the purpose of improving the film strength (printing durability) described later, a UV initiator, a maturing cross-linking agent or the like may be added to enhance the effect of heating / exposure after development. In addition, it is possible to provide an additive and an intermediate layer for improving the adhesion between the photosensitive layer and the support and for enhancing the removability of the unexposed photosensitive layer by development. For example, a compound having a diazonium structure, a phosphon compound, or the like, by adding a compound having a relatively strong interaction with the substrate or by undercoating, adhesion is improved,
The printing durability can be increased, while the addition of a hydrophilic polymer such as polyacrylic acid or polysulfonic acid or undercoating improves the developability of the non-image area and improves the stain resistance.

Next, other layers optionally provided in the planographic printing plate precursor of the invention will be described. [Protective Layer] Since the lithographic printing plate precursor according to the invention is usually exposed to light in the atmosphere, it is preferable to further provide a protective layer on the photosensitive layer using the photopolymerizable composition. The protective layer is
It prevents exposure of the photosensitive layer to low-molecular compounds such as oxygen and basic substances existing in the atmosphere, which inhibit the image forming reaction caused by exposure in the photosensitive layer, from entering the photosensitive layer.
Therefore, a property desired for such a protective layer is that the low molecular weight compound such as oxygen has low transparency, and further, the transparency of light used for exposure is good, and the adhesiveness to the photosensitive layer is excellent,
Moreover, it is desirable that it can be easily removed in the developing step after exposure.

Such a device for the protective layer has been heretofore made and described in detail in US Pat. No. 3,458,311 and JP-A-55-49729. As a material that can be used for the protective layer, for example, it is preferable to use a water-soluble polymer compound having relatively excellent crystallinity. Specifically, polyvinyl alcohol, polyvinylpyrrolidone, acidic celluloses, gelatin, gum arabic, poly Although water-soluble polymers such as acrylic acid are known, the use of polyvinyl alcohol as the main component gives the best results in terms of basic characteristics such as oxygen barrier property and removability by development. The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether, and an acetal as long as it contains an unsubstituted vinyl alcohol unit for having a necessary oxygen barrier property and water solubility. Further, similarly, a part thereof may have other copolymerization component.

Specific examples of polyvinyl alcohol include 7
1-100% hydrolyzed, molecular weight 300 to 240
The range of 0 can be mentioned. Specifically, PVA-105, PVA-110, PV manufactured by Kuraray Co., Ltd.
A-117, PVA-117H, PVA-120, PV
A-124, PVA-124H, PVA-CS, PVA
-CST, PVA-1HC, PVA-203, PVA-2
04, PVA-205, PVA-210, PVA-21
7, PVA-220, PVA-224, PVA-217
EE, PVA-217E, PVA-220E, PVA-
224E, PVA-405, PVA-420, PVA-
613, L-8 and the like.

The components of the protective layer (selection of PVA, use of additives), the coating amount and the like are selected in consideration of fogging property, adhesion and scratch resistance as well as oxygen barrier property and removability by development. Generally, the higher the hydrolysis rate of PVA used (the higher the content of the unsubstituted vinyl alcohol unit in the protective layer) and the thicker the film thickness, the higher the oxygen barrier property, which is advantageous in terms of sensitivity. However, if the oxygen barrier property is extremely increased, there arises a problem that an unnecessary polymerization reaction occurs during production or raw storage, and unnecessary fog or thickening of image lines occurs during image exposure. Also, the adhesion to the image area and scratch resistance are extremely important in handling the plate. That is, when a hydrophilic layer made of a water-soluble polymer is laminated on a new oily polymer layer, film peeling is likely to occur due to insufficient adhesive force, and the peeled portion causes defects such as poor film curing due to inhibition of oxygen polymerization.

On the other hand, various proposals have been made to improve the adhesiveness between these two layers. For example, US Patent No. 2
92, 501 and U.S. Pat. No. 4,563, 20 to 60% by weight of an acrylic emulsion or a water-insoluble vinylpyrrolidone-vinyl acetate copolymer is mixed in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesion can be obtained by laminating on the polymerized layer. Any of these known techniques can be applied to the protective layer in the present invention. For the coating method of such a protective layer,
For example, U.S. Pat. No. 3,458,311 and JP-A-55-
49729 in detail.

Further, the protective layer may be provided with other functions. For example, it has excellent transmittance of light of the wavelength used for exposure,
Moreover, the addition of a colorant (such as a water-soluble dye) capable of efficiently absorbing light having a wavelength that does not contribute to image formation can further enhance the safelight suitability without lowering the sensitivity.

[Resin Intermediate Layer] In the image recording material of the present invention, if necessary, a resin intermediate layer comprising an alkali-soluble polymer may be provided between the photosensitive layer containing the photopolymerizable compound and the support. it can. A photosensitive layer containing a photopolymerizable compound, which is an infrared-sensitive layer whose solubility in an alkali developing solution is reduced by exposure, is provided on or near the exposed surface to have good sensitivity to an infrared laser and a support. This resin intermediate layer is present between the photosensitive layer and
By functioning as a heat insulating layer, the heat generated by the exposure of the infrared laser does not diffuse to the support, and it is used efficiently.
Higher sensitivity can be achieved. In the exposure section,
Since the photosensitive layer which has become impermeable to the alkaline developer functions as a protective layer for the resin intermediate layer, the development stability is improved and an image excellent in discrimination is formed, and It is considered that the stable stability is also secured, and in the unexposed area, the uncured binder component is rapidly dissolved and dispersed in the developing solution, and further, the resin intermediate layer existing adjacent to the support. Since it is composed of an alkali-soluble polymer, it has good solubility in a developing solution, for example, even when using a developing solution having a decreased activity, because it dissolves quickly without a residual film or the like, It is considered to have excellent developability.

[Support] The support used in the lithographic printing plate precursor of the invention is not particularly limited as long as it is a dimensionally stable plate-like material, and examples thereof include paper and plastic (eg, paper).
Polyethylene, polypropylene, polystyrene, etc.) laminated paper, metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, Cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.) and the like. These are single-component sheets such as resin films and metal plates,
It may be a laminate of two or more materials, and includes, for example, paper or plastic film laminated or vapor-deposited with the metal as described above, a laminated sheet of different plastic films, and the like.

As the support, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate which has good dimensional stability and is relatively inexpensive is particularly preferable. The preferred aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and a slight amount of a foreign element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel and titanium. The content of foreign elements in the alloy is at most 10% by weight
It is the following. Aluminum which is particularly preferred in the present invention is pure aluminum, but completely pure aluminum is difficult to produce in terms of refining technology, and thus may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and conventionally known and publicly known aluminum plates can be appropriately used. The thickness of the aluminum plate is
About 0.1 to 0.6 mm, preferably 0.15 to
0.4 mm, particularly preferably 0.2 to 0.3 mm.

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

The treatment conditions for anodic oxidation cannot be unconditionally specified because they vary depending on the electrolyte used, but generally, the electrolyte concentration is 1 to 80% by weight solution, the liquid temperature is 5 to 70 ° C.
A current density of 5 to 60 A / dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 seconds to 5 minutes are suitable. The amount of the anodized film is suitably 1.0 g / m ² or more, but more preferably in the range of 2.0 to 6.0 g / m ^2. When the anodized film is less than 1.0 g / m ² , printing durability is insufficient, or the non-image area of the lithographic printing plate is easily scratched, and ink adheres to the scratched portion during printing. "Scratch stains" easily occur. Such anodizing treatment is applied to the surface used for printing the support of the lithographic printing plate, but the back surface is also covered with 0.01-3 g / m ² due to the back of the lines of electric force.
It is general that the anodic oxide coating is formed.

The hydrophilic treatment of the surface of the support is carried out after the above-mentioned anodizing treatment, and a conventionally known treatment method is used. As such a hydrophilic treatment,
US Pat. Nos. 2,714,066 and 3,181,4
No. 61, No. 3,280,734 and No. 3,902,7
There is an alkali metal silicate (eg, sodium silicate aqueous solution) method as disclosed in Japanese Patent Laid-Open No. 34-34. In this method, the support is immersed in an aqueous sodium silicate solution or electrolyzed. In addition, Japanese Patent Publication No. 36-22
063 and potassium fluorozirconate disclosed in U.S. Pat. Nos. 3,276,868 and 4,15.
A method of treating with polyvinylphosphonic acid as disclosed in JP-A-3,461 and JP-A-4,689,272 is used.

A back coat is provided on the back surface of the support, if necessary. As such a back coat, a coating composed of a metal oxide obtained by hydrolyzing and polycondensing an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174. Layers are preferably used. Among these coating layers, Si (OCH ₃ ) ₄ , Si (OC)
₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , Si (OC
A silicon alkoxy compound such as ₄ H ₉ ) ₄ is inexpensive and easily available, and a coating layer of a metal oxide provided from it is excellent in development resistance and is particularly preferable.

[Exposure] The lithographic printing plate precursor of the invention can be prepared as described above. This lithographic printing plate precursor is imagewise exposed by a solid-state laser and a semiconductor laser that emit infrared rays having a wavelength of 760 nm to 1200 nm. Scanning exposure for image formation can be performed using a known device. As the exposure device, an inner drum system, an outer drum system, a flat head system, or the like can be selected and used. In the lithographic printing plate precursor according to the invention, a combination of a high-sensitivity specific polymerization initiator and a polymerization inhibitor suppresses an undesired unexposed portion of the polymerization reaction due to low-energy exposure, and thus, for example, a low extinction ratio. It is also suitable for an exposure process and the like, and when applied to such a process, its effect is remarkable.

In the present invention, the developing treatment may be carried out immediately after the laser irradiation, but it is preferable to carry out the heating treatment between the laser exposure step and the developing step. The heat treatment is preferably performed within the range of 80 ° C. to 150 ° C. for 10 seconds to 5 minutes. This heat treatment can reduce the laser energy required for recording during laser irradiation.

[Development] The lithographic printing plate precursor according to the invention is usually imagewise exposed by an infrared laser and then preferably developed with water or an alkaline aqueous solution. In the present invention, the development treatment may be carried out immediately after the laser irradiation, but a heat treatment step may be provided between the laser irradiation step and the development step. The heat treatment condition is 80 ° C to 1
It is preferable to perform the heating in the range of 50 ° C for 10 seconds to 5 minutes.
This heat treatment can reduce the laser energy required for recording during laser irradiation. The developer is preferably an alkaline aqueous solution, and a preferable pH range is pH 10.5 to 12.5. It is more preferable to perform development processing with an alkaline aqueous solution in the range of 0 to 12.5. When an alkaline aqueous solution having a pH of less than 10.5 is used, the non-image area tends to be contaminated, and when development processing is performed with an aqueous solution having a pH of more than 12.5, the strength of the image area may decrease.

When an alkaline aqueous solution is used as the developing solution, a conventionally known alkaline aqueous solution can be used as the developing solution and the replenishing solution for the image recording material of the present invention. For example,
Sodium silicate, potassium, sodium triphosphate, potassium, ammonium, dibasic sodium, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium hydrogencarbonate, potassium, ammonium, Examples thereof include inorganic alkali salts such as sodium borate, potassium borate, ammonium borate, sodium hydroxide, ammonium borate, potassium borate and lithium borate. Also, monomethylamine, dimethylamine,
Trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, ethyleneimine, ethylenediamine, pyridine, etc. Organic alkaline agents are also used. These alkaline agents may be used alone or in combination of two or more.

Further, in the case of developing using an automatic developing machine, the same developer as the developer or an aqueous solution (replenisher) having a higher alkaline strength than the developer is added to the developer so that the developer can be stored in the developer tank for a long time. It is known that a large amount of lithographic printing plate precursor can be processed without changing the developing solution. Also in the present invention, this replenishment system is preferably applied.

If necessary, various surfactants, organic solvents and the like may be added to the developing solution and the replenishing solution for the purpose of accelerating or suppressing the developing property, dispersing the development residue and enhancing the ink affinity of the printing plate image area. . The developer preferably contains 1 to 20% by weight of a surfactant, and more preferably 3 to 10% by weight. If the amount of the surfactant added is less than 1% by weight, the effect of improving the developability cannot be sufficiently obtained, and the amount is 20% by weight.
If it is added in excess, the adverse effects such as deterioration of strength such as abrasion resistance of the image are likely to occur. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Specifically, for example, sodium salt of lauryl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, sodium salt of octyl alcohol sulfate, for example, sodium salt of isopropylnaphthalenesulfonic acid, sodium salt of isobutylnaphthalenesulfonic acid, polyoxyethylene glycol. Alkyl aryl sulfonates such as sodium salt of mononaphthyl ethyl sulfate, sodium salt of dodenyl benzene sulfonic acid, sodium salt of metanitrobenzene sulfonic acid, etc., and higher alcohols having 8 to 22 carbon atoms such as secondary sodium alkyl sulfate. esters sulfate, fatty alcohol phosphoric acid ester salts such as such as sodium salt of cetyl alcohol phosphate esters, for example C ₁₇ H ₃₃ CON (C ₃₎ CH ₂ CH ₂
Sulfonates of alkyl amides such as SO ₃ Na, for example, dibasic aliphatic ester sulfonates such as sodium sulfosuccinate dioctyl ester, sodium sulfosuccinate dihexyl ester, such as lauryl trimethyl ammonium chloride, lauryl trimethyl ammonium Ammonium salts such as methosulfate, for example, amine salts such as stearamidoethyldiethylamine acetate, for example, polyhydric alcohols such as fatty acid monoester of glycerol and fatty acid monoester of pentaerythritol, for example, polyethylene glycol mononaphthylethyl, polyethylene Polyethylene glycol ethyls such as glycol mono (noelphenol) ethyl are included.

Preferred organic solvents include those having a water solubility of about 10% by weight or less, and more preferably those having a water solubility of 5% by weight or less. For example, 1-phenylethanol, 2-phenylethanol, 3-phenylpropanol, 1,4-phenylbutanol, 2,2-phenylbutanol, 1,2
-Phenoxyethanol, 2-benzyloxyethanol, o-methoxybenzyl alcohol, m-methoxybenzyl alcohol, p-methoxybenzyl alcohol,
Examples thereof include benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 4-methylcyclohexanol and 3-methylcyclohexanol. The content of the organic solvent is preferably 1 to 5% by weight based on the total weight of the developing solution at the time of use. The amount used is closely related to the amount used of the surfactant, and it is preferable to increase the amount of the surfactant as the amount of the organic solvent increases. This is because if a large amount of the organic solvent is used in a state where the amount of the surfactant is small, the organic solvent does not dissolve, so that it is difficult to expect to secure good developability.

Further, the developing solution and the replenishing solution may contain additives such as an antifoaming agent and a water softening agent, if necessary. Examples of the water softener include Na ₂ P ₂ O
₇ , Na ₅ P ₃ O ₃ , Na ₃ P ₃ O ₉ , Na ₂ O ₄ P (NaO
₃ P) Ρ O ₃ Na ₂ , polyphosphonates such as calgon (sodium polymetaphosphate), for example, ethylenediaminetetraacetic acid, its potassium salt, its sodium salt; diethylenetriaminepentaacetic acid, its potassium salt, sodium salt; triethylenetetraminehexaacetic acid , Its potassium salt, its sodium salt; hydroxyethylethylenediaminetriacetic acid, its potassium salt, its sodium salt;
Nitrilotriacetic acid, its potassium salt, its sodium salt; 1,2-diaminocyclohexanetetraacetic acid, its potassium salt, its sodium salt, 1,3-diamino-2
-Aminopolycarboxylic acids such as propanoltetraacetic acid, its potassium salt, its sodium salt, etc., 2
-Phosphonobutane tricarboxylic acid-1,2,4, its potassium salt, its sodium salt; 2-phosphonobutanone tricarboxylic acid-2,3,4, its potassium salt, its sodium salt; 1-phosphonoethane tricarboxylic acid -1,
2,2, its potassium salt, its sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, its potassium salt, its sodium salt; aminotri (methylenephosphonic acid), its potassium salt, its sodium salt, etc. Organic phosphonic acids can be mentioned. The optimum amount of such a water softener varies depending on the hardness of the hard water used and the amount used, but is generally 0.01 to 5% by weight, more preferably in the developer at the time of use. Is 0.01-
It may be contained in the range of 0.5% by weight.

Further, when the lithographic printing plate is developed using an automatic processor, the developing solution becomes fatigued depending on the processing amount. Therefore, the replenishing solution or a fresh developing solution is used to improve the processing ability. You may recover. In this case, US Pat. No. 4,88
Replenishment by the method described in 2,246 is preferred.

A developing solution containing such a surfactant, an organic solvent, a reducing agent and the like is described in, for example, JP-A-51-
No. 77401, benzyl alcohol,
A developer composition consisting of an anionic surfactant, an alkaline agent and water, consisting of an aqueous solution containing benzyl alcohol, an anionic surfactant and a water-soluble sulfite described in JP-A-53-44202. Developer composition,
Examples thereof include a developer composition containing an organic solvent having a solubility in water of 10% by weight or less at room temperature, an alkaline agent, and water, which are described in JP-A-55-155355, and are also suitable for the present invention. Used for.

The printing plate developed using the above-described developing solution and replenishing solution is post-treated with washing water, a rinsing solution containing a surfactant, a desensitizing solution containing gum arabic and a starch derivative. It When the image recording material of the present invention is used as a printing plate precursor, various combinations of these treatments can be used as a post-treatment.

In recent years, automatic developing machines for printing plates have been widely used in the plate making / printing industry in order to rationalize and standardize the plate making work. This automatic developing machine is generally composed of a developing section and a post-processing section, and is composed of a device for conveying a printing plate material, each processing liquid tank, and a spray device. Each of the processing liquids pumped up is sprayed from a spray nozzle for development processing. Further, recently, a method has also been known in which a printing plate precursor is dipped and conveyed by a submerged guide roll or the like into a processing liquid tank filled with the processing liquid for processing. In such automatic processing,
It is possible to carry out the processing while supplementing the replenishing solution to each processing solution according to the processing amount, operating time and the like. Also, the electric conductivity can be detected by a sensor and automatically replenished. Further, a so-called disposable processing method of processing with a substantially unused processing liquid can be applied.

The lithographic printing plate obtained as described above can be subjected to a printing step after applying a desensitizing gum if desired, but when a lithographic printing plate having higher printing durability is desired, Is subjected to a burning process. When burning a lithographic printing plate, before printing
No. 2518, No. 55-28062, JP-A-62-3
It is preferable to treat with a surface-adjusting solution as described in JP-A-1859 and JP-A-61-159655.

As the method, a sponge or absorbent cotton soaked with the surface-adjusting solution may be applied onto the planographic printing plate, or
A method in which the printing plate is dipped in a vat filled with a surface-adjusting solution to be applied, or an application by an automatic coater is applied. Further, making the coating amount uniform with a squeegee or a squeegee roller after coating gives more preferable results. The amount of the surface conditioning solution applied is generally 0.03 to 0.8 g / m ^2.
(Dry weight) is suitable.

The planographic printing plate coated with the surface-adjusting solution is dried if necessary and then burned with a burning processor (for example,
It is heated to a high temperature with a burning processor: BP-1300) sold by Fuji Photo Film Co., Ltd. The heating temperature and the heating time in this case depend on the kinds of components forming the image, but are within the range of 180 to 300 ° C.
The range of up to 20 minutes is preferred.

The lithographic printing plate which has been subjected to the burning treatment can be subjected to conventional treatments such as washing with water and gumming, if necessary, but a surface-adjusting solution containing a water-soluble polymer compound or the like. When is used, so-called desensitizing treatment such as gumming can be omitted.

The lithographic printing plate obtained by such treatment is applied to an offset printing machine or the like and used for printing a large number of sheets.

[0137]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

[Synthesis of divalent onium salt] The sulfonium and iodonium mother skeletons used in the present invention are described in JP-A-11-1999.
-80118, JP-A-11-153870, J. O
rg. Chem 1992, 57, 6810-681.
4, Synthesi 1999 p. 1897-18
99, Tetrahedoron 1995, vol5
1. P6229-6239, and J. Org. Che
m1978, 43, 3058, and the onium salt compound was obtained by salt exchange according to need.

(Synthesis Example 1: Synthesis of Exemplified Compound I-1)
4.4 g of iodosobenzene (0.02 mol) was dissolved in 50 ml of dichloromethane, 3.4 ml (0.02 mol) of trifluoromethanesulfonic anhydride was added dropwise at room temperature, the mixture was stirred for 5 hours, and the precipitated solid was filtered, By washing with ethyl acetate and drying under reduced pressure, the exemplified compound (I-
The divalent onium salt of 1) is obtained in a yield of 45%.

(Synthesis Example 2: Synthesis of Exemplified Compound S-9) 1.58 g of Exemplified Compound (I-1) obtained in Synthesis Example 1
(2 mmol), 0.018 g of copper (II) acetate (0.
1 mmol) and 2.7 ml of diphenyl sulfide, and heated at 190 ° C. for 40 minutes. Then, the mixture was cooled to room temperature and washed with ethyl acetate and water to obtain a divalent onium salt of Exemplified Compound (S-9) in a yield of 40%.

(Examples 1 to 10) [Production of substrate] An aluminum plate (material 1050) having a thickness of 0.3 mm was washed with trichlorethylene to degrease it, and then a nylon brush and a 400 mesh pumice-water suspension were used. Etching this surface with a grained surface,
After washing with water, it was further immersed in 20% nitric acid for 20 seconds and washed with water.
At this time, the etching amount of the grained surface was about 3 g / m ² . Next, this plate was provided with a DC electrode oxide film of 3 g / m ² at a current density of 15 A / dm ² using 7% sulfuric acid as an electrolytic solution, washed with water and dried to prepare a substrate (A). Substrate (A) is treated with a 2 wt% sodium silicate aqueous solution at 25 ° C. for 15
It was treated for seconds and washed with water to prepare a substrate (B).

[Formation of Intermediate Layer] Next, S is formed by the following procedure.
A liquid composition (sol solution) of Method G was prepared. <Sol liquid composition> -Methanol 130 g-Water 20 g-85 wt% phosphoric acid 16 g-Tetraethoxysilane 50 g-3-methacryloxypropyltrimethoxysilane 60 g The above compounds were mixed and stirred. An exotherm was observed in about 5 minutes. After reacting for 60 minutes, the content was transferred to another container, and 3000 g of methanol was added to obtain a sol liquid. This sol solution is diluted with methanol / ethylene glycol = 9/1 (weight ratio) so that the amount of Si on the substrate [A] manufactured as described above becomes 3 mg / m ^2. It was applied and dried at 100 ° C. for 1 minute to obtain a substrate [C].

[Formation of Photosensitive Layer] Any one of the substrates [A] to [C] prepared as described above is used as a support, and the surface thereof is coated with a photosensitive layer coating solution having the following composition. 1
Example 1 was dried to form a photosensitive layer of 1.4 g / m ^2.
-9 planographic printing plate precursors were obtained. A substrate to be used, (A) a photothermal conversion agent, (B) a compound having a polymerizable unsaturated group,
The divalent onium salt (C) and the binder (D) are as shown in Table 1 below.

[0144] (Photosensitive layer coating liquid) -Addition polymerizable compound (compound shown in Table 1) 1.5 g -Binder (compound shown in Table 1) 2.0 g -Photothermal conversion agent (compounds listed in Table 1) 0.1 g -Polymerization initiator such as divalent onium salt (compound shown in Table 1) 0.15 g -Fluorine-based nonionic surfactant (MegaFac F-177P,                         Dainippon Ink and Chemicals Co., Ltd.) 0.02g ・ The counter anion of Victoria Pure Blue BOH is 1-naphthalene       Dyes with sulfonate anion 0.04g ・ Methyl ethyl ketone 10g ・ Methanol 7g ・ 2-Methoxy-1-propanol 10 g

[0145]

[Chemical 28]

[0146]

[Table 1]

(Additionally Polymerizable Compounds in Table 1) (M-1) Pentaerythritol Tetraacrylate (M-2) Glycerin Dimethacrylate Hexamethylene Diisocyanate Urethane Prepolymer

(Binders in Table 1) (B-1) Allyl methacrylate / methacrylic acid / N-isopropylamide copolymer (copolymerization molar ratio: 67/13/20) Acid value (measured by NaOH titration) 15 meq / g Polymerization average molecular weight 130,000 (B-2) Allyl methacrylate / methacrylic acid copolymer (copolymerization molar ratio: 83/17) Acid value (measured by NaOH titration) 1.55 meq / g Polymerization average molecular weight 12.5 Polyurethane resin (a) 4,4'-diphenylmethane diisocyanate (b) hexamethylene diisocyanate (c) polypropylene glycol (weight average molecular weight: 10)
00) (d) 2,2-bis (hydroxymethyl) propionic acid ((a) / (b) / (c) / (d) copolymerization molar ratio: 40/10/1
5/35) Acid value (measured by NaOH titration) 1.05 meq / g Polymerization average molecular weight 45,000

(Comparative Examples 1 and 2) Substrates [A] for comparison
And (C) 2 in the photosensitive layer coating liquid on the substrate [B]
A photosensitive layer was prepared by using a photosensitive layer coating solution having the composition shown in Table 1 except that a polymerization initiator (HI, HS) having a monovalent onium salt structure represented by the following formula was added in place of the valent onium salt. It was formed to obtain a lithographic printing plate precursor (Comparative Examples 1 and 2).

[0150]

[Chemical 29]

[Exposure and development] The obtained lithographic printing plate precursor was output 500 mW, wavelength 830 nm, beam diameter 17 μm.
After exposure with a (l / e ² ) semiconductor laser at a main scanning speed of 5 m / sec, DN3C developer, DP-4 developer, or D-1 developer of the following composition manufactured by Fuji Film Co., Ltd. And an automatic processor equipped with rinse liquid FR-3 (1: 7) (manufactured by Fuji Photo Film Co., Ltd .: PS processor 900V
R) was used for development, and the sensitivity was evaluated as follows. It should be noted that which developing solution was used in the development treatment is also shown in Table 1 above.

[0152] (D-1 developer) ・ Potassium hydroxide 3g ・ Sodium hydrogen carbonate 1g ・ Potassium carbonate 2g ・ Sodium sulfite 1g ・ Polyethylene glycol mononaphthyl ether 150g ・ Dibutylnaphthalenesulfonic acid sodium salt 50g ・ Ethylenediamine tetraacetic acid tetrasodium salt 8g ・ Water 785g

[Evaluation of lithographic printing plate precursor] (Evaluation of sensitivity) Immediately after preparation, the obtained lithographic printing plate precursor was exposed with a semiconductor laser emitting infrared rays having a wavelength of about 830 to 850 nm. After exposure, developer DN-3C manufactured by Fuji Photo Film Co., Ltd. (diluted with water at a ratio of 1: 2) or developer DP-4 manufactured by Fuji Photo Film Co., Ltd.
(Diluted with water at a ratio of 1: 8), the above D-1 developer (1:
And diluted with water at a ratio of 5) and washed with water. The amount of energy required for recording was calculated based on the line width of the image obtained at these times, the laser output, the loss in the optical system, and the scanning speed. The smaller the value, the higher the sensitivity. The evaluation results are also shown in Table 1.

From the results shown in Table 1, it can be seen that the lithographic printing plate precursor according to the invention has high sensitivity. On the other hand, the lithographic printing plate precursors of Comparative Examples 1 and 2 using the polymerization initiator having no divalent onium salt structure were compared with Examples 1 and 8 obtained under the same conditions except for the polymerization initiator. It turned out that the sensitivity was poor.

The lithographic printing plate precursor thus obtained was used as T
An image of the test pattern was drawn (exposure) with a redsetter under the conditions of a beam intensity of 9 w and a drum rotation speed of 150 rpm. First, the lithographic printing plate precursor exposed under the above conditions was subjected to the above-mentioned D-1 developer (diluted with water at a ratio of 1: 5) and Finisher FP2W manufactured by Fuji Photo Film Co., Ltd. (diluted with 1: 1). Using a PS processor 900H manufactured by Fuji Photo Film Co., Ltd., the liquid temperature was kept at 30 ° C. and the development time was 12 seconds.
In each of the obtained lithographic printing plates, a good image was formed without causing stains on the non-image area.

(Examples 11 to 20, Comparative Examples 3 and 4) Polyvinyl alcohol (saponification degree: 9) was formed on the photosensitive layer of the lithographic printing plate precursors obtained in Examples 1 to 10 and Comparative Examples 1 and 2.
A 3% by weight aqueous solution of 8 mol% and a degree of polymerization of 550) was applied so that the coating amount after drying was 2 g / m ^2, and dried at 100 ° C. for 1 minute to form a protective layer on the photosensitive layer. Example 10
20 and Comparative Examples 3 and 4 were obtained as planographic printing plate precursors. The lithographic printing plate precursor thus obtained was exposed and developed under the same conditions as in Examples 1 to 10 to prepare a lithographic printing plate, and the sensitivity was evaluated in the same manner. The results are also shown in Table 1 above.

From the results shown in Table 1, even when the protective layer is provided on the photosensitive layer, Examples 1 to 10 having no protective layer are shown.
Also, the same tendency as in Comparative Examples 1 and 2 was observed, and the lithographic printing plate precursor of the present invention was excellent in sensitivity, and it was observed that the performance was improved by providing the protective layer. The lithographic printing plate precursors of Comparative Examples 3 and 4 using the polymerization initiator having a salt structure were inferior in sensitivity to Examples 11 and 18 obtained under the same conditions except for the polymerization initiator.

(Examples 21 and 22) [Formation of resin intermediate layer] The substrate [A] was coated with the following resin intermediate layer forming coating solution [II] with a wire bar and dried at 140 ° C in a warm air dryer. And dried for 60 seconds to form a resin intermediate layer. The coating amount after drying was 0.6 g / m ² . (Coating liquid [II] for resin intermediate layer) Binder [BN-1] 2.0 g Copolymer molar ratio of N- (p-aminosulfonylphenyl) methacrylamide, methacrylic acid and methyl methacrylate: 50/25 / 25 copolymer, weight average molecular weight 60,000) -Fluorine-based nonionic surfactant 0.02 g (Megafuck F-177P, Dainippon Ink and Chemicals, Inc.)-Victoria Pure Blue 0.04 g-Methyl ethyl ketone 10 g- Methanol 7 g-γ-butyrolaton 10 g

[Formation of Photosensitive Layer] On the resin intermediate layer,
The following photosensitive layer forming coating solution [III] was applied with a wire bar so that the total coating amount of the resin intermediate layer and the photosensitive layer would be 1.3 g / m ^2, and was applied with a warm air dryer at 120 ° C. Fifty
A photosensitive layer was formed by drying for 2 seconds to obtain a lithographic printing plate precursor of Example 22. In addition, on the obtained photosensitive layer, Examples 11 to 11
A polyvinyl alcohol aqueous solution was applied in the same manner as in 20 to form a protective layer, whereby a lithographic printing plate precursor of Example 23 was obtained. (Coating liquid [III] for photosensitive layer) -Addition polymerizable compound [M-1] 1.5 g-Binder [B-1] 2.0 g-Photothermal conversion agent [DX-1] 0.1 g-Divalent onium salt [S-9] 0.15 g-Fluorine-based nonionic surfactant 0.02 g (Megafuck F-177P, manufactured by Dainippon Ink and Chemicals, Inc.)-Victoria Pure Blue 0.04 g-Methyl ethyl ketone 20 g-Methanol 2 g-2 -Methoxy-1-propanol 10 g

Each lithographic printing plate precursor thus obtained was used as in Example 1 above.
Under the same conditions as in No. 10-10, exposure and development were performed to prepare a lithographic printing plate, and the sensitivity was evaluated in the same manner. The developer used at this time was the D-1 developer (diluted with water at a ratio of 1: 5). As a result of the evaluation, in Example 22, the sensitivity was 75 mJ / c.
m ² , the sensitivity in Example 23 was 70 mJ / cm ² , and it was confirmed that the lithographic printing plate precursor according to the invention was excellent in sensitivity even in the mode in which the resin intermediate layer was provided.

[0161]

INDUSTRIAL APPLICABILITY The negative lithographic printing plate precursor of the present invention has the effect that it can be written by an infrared laser and is excellent in sensitivity during recording.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H025 AA01 AB03 AC08 AD01 BC32                       BC42 BC51 CA48 CC20 FA03                       FA10 FA17                 2H096 AA07 AA08 BA05 BA16 BA20                       EA04 GA08                 2H114 AA04 AA22 AA24 BA01 BA10                       DA48 DA51 DA52 EA01 EA02                       FA06 FA10

Claims (2)

[Claims] 1. A (A) photothermal conversion agent, (B) on a support.
A compound having a polymerizable unsaturated group, and (C) containing an onium salt having two or more cation moieties in one molecule,
A lithographic printing plate precursor for heat mode, comprising a photosensitive layer capable of recording with a heat mode laser. 2. The lithographic printing plate precursor for heat mode according to claim 1, wherein the exposure wavelength of the heat mode laser is 760 to 1200 nm.