JP4689712B2 - Planographic printing plate precursor - Google Patents

Description

The present invention relates to a lithographic printing plate precursor having a photosensitive layer writable negative infrared laser, particularly, the strength of the image portion of the recording layer is high, about the lithographic printing plate precursor having excellent printing durability.

In recent years, the development of lasers has been remarkable. In particular, solid lasers and semiconductor lasers having a light emitting region from the near infrared region to the infrared region have been increasing in output and size. Therefore, these lasers are very useful as an exposure light source when making a plate directly from digital data such as a computer.
The above-mentioned infrared laser having a light emitting region in the infrared region is used as an exposure light source. The negative lithographic printing plate material for infrared laser includes an infrared absorber, a polymerization initiator that generates radicals by light or heat, and a polymerizable compound. A lithographic printing plate material having a photosensitive layer comprising:

Usually, such a negative type image recording material uses a recording system in which a radical generated by light or heat is used as an initiator to cause a polymerization reaction, and a recording layer in an exposed portion is cured to form an image portion. Yes. Such a negative type image forming material has a lower image forming property than a positive type in which the recording layer is solubilized by the energy of infrared laser irradiation, and promotes a curing reaction by polymerization to provide a strong image portion. In order to form, it is common to heat-process before a image development process.
As a printing plate having such a light- or heat-polymerized recording layer, a photopolymerizable or heat-polymerizable composition as described in JP-A-8-108621 and JP-A-9-34110. A technique of using as a photosensitive layer is known. Although these photosensitive layers are excellent in high-sensitivity image-forming properties, when a hydrophilically treated substrate is used as a support, adhesion at the interface between the photosensitive layer and the support is low, and printing durability is poor. There was a problem.
In addition, in order to improve the sensitivity, use of a high-power infrared laser has been studied, but there is also a problem that the photosensitive layer is ablated during laser scanning and contaminates the optical system.

The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is a negative in which ablation in laser scanning during recording is suppressed, the strength of the formed image portion is high, and the printing durability is excellent. It is to provide a lithographic printing plate precursor .

As a result of intensive studies, the present inventors have found that recording with excellent image area strength is possible by using a polyurethane resin as a falling molecular compound that is insoluble in water and soluble in an alkaline aqueous solution. The present invention has been completed.
That is, heat mode corresponding negative-working lithographic printing plate precursor of the present invention comprises a support, (A) having a carboxyl group, soluble polyurethane resin insoluble and alkali aqueous solution in water, (B) a radical polymerizable compound (C) a photothermal conversion agent that is a dye having an absorption maximum at a wavelength of 760 nm to 1200 nm , (D) (C) a compound that generates radicals by heat mode exposure of light having a wavelength that can be absorbed by the photothermal conversion agent, and (E) A photosensitive layer containing a colorant different from (C) and capable of recording an image by heat mode exposure is provided .

  In the present invention, “corresponding to heat mode” means that recording by heat mode exposure is possible. The definition of the heat mode exposure in this invention is explained in full detail. Hans-Joachim Time, IS & Ts NIP 15: 1999 International Conference on Digital Printing Technologies. P. 209, a photoabsorbing substance (for example, a dye) is photoexcited in a photosensitive material, and undergoes a chemical or physical change to form an image, from the photoexcitation of the photoabsorbing substance to a chemical or physical change. It is known that there are two modes in the above process. One is that the photo-excited light-absorbing substance is deactivated by some photochemical interaction (for example, energy transfer, electron transfer) with other reactants in the photosensitive material, and as a result, the activated reactant is The so-called photon mode that causes the chemical or physical change necessary for the above-described image formation, and the other is that the photo-excited light-absorbing material generates heat and deactivates, and the reaction material is converted into the above-described using the heat. This is a so-called heat mode that causes a chemical or physical change necessary for image formation. In addition, there are special modes such as ablation that explosively scatters by the energy of light gathered locally, and multiphoton absorption in which one molecule absorbs many photons at once, but they are omitted here.

The exposure process using each of the above modes is called font mode exposure and heat mode exposure. The technical difference between the font mode exposure and the heat mode exposure is whether the energy amount of several photons to be exposed can be added to the target energy amount of the reaction. For example, consider that a certain reaction is caused by using n photons. In font mode exposure, photochemical interaction is used, so that one-photon energy cannot be added together due to the requirement of quantum energy and momentum conservation laws. That is, in order to cause some kind of reaction, a relationship of “one photon energy amount ≧ reaction energy amount” is necessary. On the other hand, in heat mode exposure, heat is generated after light excitation, and light energy is converted into heat and used, so that the amount of energy can be added. Therefore, it is sufficient that there is a relationship of “energy amount of n photons ≧ energy amount of reaction”. However, this energy amount addition is restricted by thermal diffusion. That is, if the next photoexcitation-deactivation process occurs and the heat is generated before the heat escapes from the exposed portion (reaction point) of interest now, due to thermal diffusion, the heat is surely accumulated and added, and the temperature of that portion increases. Leads to. However, when the next heat generation is slow, the heat escapes and does not accumulate. In other words, in the heat mode exposure, even when the same total exposure energy amount is used, the result is different between the case where the high energy amount light is irradiated for a short time and the case where the low energy amount light is irradiated for a long time. It becomes advantageous for accumulation.
Of course, in font mode exposure, a similar phenomenon may occur due to the diffusion of subsequent reactive species, but basically this does not happen.
That is, in terms of the characteristics of the photosensitive material, in the font mode, the intrinsic sensitivity of the photosensitive material (energy for reaction required for image formation) with respect to the exposure power density (w / cm ² ) (= energy density per unit time). In the heat mode, the intrinsic sensitivity of the photosensitive material increases with respect to the exposure power density. Therefore, if the exposure time is fixed so as to maintain the necessary productivity for practical use as an image recording material, when comparing each mode, the font mode exposure usually has a high sensitivity of about 0.1 mJ / cm ^2. However, since the reaction occurs at any small exposure dose, the problem of low exposure fogging in unexposed areas 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 level or more, and usually about 50 mJ / cm ² is necessary because of the thermal stability of the photosensitive material. Is avoided.
And, in fact heat mode exposure requires exposure power density at the plate surface of the photosensitive material is 5000 W / cm ² or more, preferably it is necessary to 10000 W / cm ² or more. However, although not described in detail here, the use of a high power density laser of 5.0 × 10 ⁵ / cm ² or more is not preferable because of problems such as ablation and contamination of the light source.

Although the action of the present invention is not clear, in the planographic printing plate precursor of the present invention, by using a specific polyurethane resin (A) as a polymer compound soluble in an alkaline aqueous solution, hydrogen bonding of the main chain urethane group When this lithographic printing plate precursor is used in the photosensitive layer of a lithographic printing plate precursor for heat mode, the ablation is suppressed during infrared laser scanning exposure, and damage to the negative image area and scanning exposure are performed. It is thought that contamination of the optical system such as the spinner mirror of the machine is suppressed.
In addition, since the polyurethane resin is excellent in film forming properties, the amount of dissolved oxygen in the film after forming the coating film is low, and further, the oxygen blocking property from the outside is high, so that inhibition of polymerization by oxygen of the radical polymerizable compound is suppressed. . Therefore, since it becomes a highly cured film by polymerization, when used in the photosensitive layer of a lithographic printing plate precursor, the formed image portion is sufficiently cured, and a printing plate with high printing durability can be formed. .
Furthermore, since the polyurethane resin used in the present invention has a urethane group, which is a polar group, in the main chain and a carboxyl group, the polyurethane resin has excellent affinity for a highly polar medium such as water. Therefore, compared to acrylic resin, which is an alkali-soluble resin usually used for image recording materials, it is superior in water dispersibility, and when used in a lithographic printing plate precursor, development residue that causes problems in running suitability is unlikely to occur. It also has the advantage of.

  According to the present invention, recording can be performed directly from digital data such as a computer by recording using a solid-state laser and a semiconductor laser that emits infrared rays, and ablation occurs when used for a photosensitive layer for a lithographic printing plate precursor. Therefore, it is possible to provide a negative image recording material that can achieve excellent printing durability.

Hereinafter, the present invention will be described in detail.
Negative planographic printing plate precursor of the present invention comprises a support, (A) having a carboxyl group, water insoluble and soluble polyurethane resin in an aqueous alkali solution, (B) a radical polymerizable compound, (C) Wavelength A photothermal conversion agent that is a dye having an absorption maximum from 760 nm to 1200 nm , (D) (C) a compound that generates radicals by heat mode exposure of light having a wavelength that can be absorbed by the photothermal conversion agent, and (E) (C And a photosensitive layer capable of recording an image by heat mode exposure. Hereinafter, each compound that can be used in the lithographic printing plate precursor according to the invention will be described in order.

(A) A polyurethane resin having a carboxyl group, insoluble in water, and soluble in an alkaline aqueous solution (hereinafter, appropriately referred to as a specific polyurethane resin)
The specific polyurethane resin used as an essential component in the photosensitive layer of the heat mode-compatible negative planographic printing plate precursor of the present invention is represented by at least one diisocyanate compound represented by the following general formula (2) and the general formula (3). It is a polyurethane resin having as a basic skeleton a structural unit represented by a reaction product with at least one diol compound represented.

OCN-X ⁰ -NCO (2)
HO-Y ⁰ -OH (3)
(In the formula, X ⁰ and Y ⁰ represent a divalent organic residue.)

Among the isocyanate compounds, a diisocyanate compound represented by the following general formula (4) is preferable.

OCN-L ¹ -NCO (4)

In the formula, L ¹ represents a divalent aliphatic or aromatic hydrocarbon group which may have a substituent. If necessary, L ¹ may have another functional group that does not react with an isocyanate group, such as an ester, urethane, amide, or ureido group.

A) Diisocyanate Compound Specific examples of the diisocyanate compound represented by the general formula (4) include those shown below.
That is, 2,4-tolylene diisocyanate, dimer of 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate Aromatic diisocyanate compounds such as 1,5-naphthylene diisocyanate, 3,3′-dimethylbiphenyl-4,4′-diisocyanate, etc .;
Aliphatic diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, dimer acid diisocyanate and the like;
Alicyclic diisocyanate compounds such as isophorone diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4 (or 2,6) diisocyanate, 1,3- (isocyanatomethyl) cyclohexane;
And a diisocyanate compound which is a reaction product of a diol and a diisocyanate such as an adduct of 1 mol of 1,3-butylene glycol and 2 mol of tolylene diisocyanate.

B) Diol compound As the diol compound, a polyether diol compound, a polyester diol compound, a polycarbonate diol compound and the like are widely used.
Examples of the polyether diol compound include compounds represented by the following formulas (5), (6), (7), (8) and (9), and random copolymerization of ethylene oxide and propylene oxide having a hydroxyl group at the terminal. Coalesce is mentioned.

In the formula, R ¹ represents a hydrogen atom or a methyl group, and X represents the following group.

  A, b, c, d, e, f, and g each represent an integer of 2 or more, and preferably an integer of 2 to 100.

Specific examples of the polyether diol compound represented by the formulas (5) and (6) include those shown below.
That is, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, di-1,2-propylene glycol, tri-1,2-propylene glycol, tetra-1, 2-propylene glycol, hexa-1,2-propylene glycol, di-1,3-propylene glycol, tri-1,3-propylene glycol, tetra-1,3-propylene glycol, di-1,3-butylene glycol, Tri-1,3-butylene glycol, hexa-1,3-butylene glycol, polyethylene glycol having a weight average molecular weight of 1000, polyethylene glycol having a weight average molecular weight of 1500, poly having a weight average molecular weight of 2000 Tylene glycol, polyethylene glycol with a weight average molecular weight of 3000, polyethylene glycol with a weight average molecular weight of 7500, polypropylene glycol with a weight average molecular weight of 400, polypropylene glycol with a weight average molecular weight of 700, polypropylene glycol with a weight average molecular weight of 1000, polypropylene glycol with a weight average molecular weight of 2000 , Polypropylene glycol having a weight average molecular weight of 3000, polypropylene glycol having a weight average molecular weight of 4000, and the like.

Specific examples of the polyether diol compound represented by the formula (7) include the following.
Sanyo Chemical Industries, Ltd. (trade name) PTMG650, PTMG1000, PTMG2000, PTMG3000, etc.

Specific examples of the polyether diol compound represented by the formula (8) include those shown below.
Sanyo Chemical Industries, Ltd. (trade name) New Pole PE-61, New Pole PE-62, New Pole PE-64, New Pole PE-68, New Pole PE-71, New Pole PE-74, New Pole PE-75, New Pole PE-78, New Pole PE-108, New Pole PE-128, New Pole PE-61, etc.

Specific examples of the polyether diol compound represented by the formula (9) include the following.
Sanyo Chemical Industries, Ltd. (trade name) New Pole BPE-20, New Pole BPE-20F, New Pole BPE-20NK, New Pole BPE-20T, New Pole BPE-20G, New Pole BPE-40, New Pole BPE-60, New Pole BPE-100, New Pole BPE-180, New Pole BPE-2P, New Pole BPE-23P, New Pole BPE-3P, New Pole BPE-5P, etc.

Specific examples of the random copolymer of ethylene oxide and propylene oxide having a hydroxyl group at the terminal include the following.
Sanyo Chemical Industries, Ltd. (trade name) New Pole 50HB-100, New Pole 50HB-260, New Pole 50HB-400, New Pole 50HB-660, New Pole 50HB-2000, New Pole 50HB-5100, and the like.

  Examples of the polyester diol compound include compounds represented by formulas (10) and (11).

In the formula, L ² , L ³ and L ⁴ may be the same or different and each represents a divalent aliphatic or aromatic hydrocarbon group, and L ⁵ represents a divalent aliphatic hydrocarbon group. Preferably, L ² , L ³ and L ⁴ each represent an alkylene group, an alkenylene group, an alkynylene group or an arylene group, and L ⁵ represents an alkylene group. In L ² , L ³ , L ⁴ , and L ⁵ , other functional groups that do not react with the isocyanate group such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group, or halogen atom are present. May be. nl and n2 are each an integer of 2 or more, preferably an integer of 2 to 100.

  As the polycarbonate diol compound, there is a compound represented by the formula (12).

In the formula, L ⁶ may be the same or different and each represents a divalent aliphatic or aromatic hydrocarbon group. Preferably, L ⁶ represents an alkylene group, an alkenylene group, an alkynylene group or an arylene group. In addition, other functional groups that do not react with the isocyanate group, such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group or halogen atom may be present in L ⁶ . n3 is an integer of 2 or more, preferably an integer of 2 to 100.

  Specific examples of the diol compound represented by the formula (10), (11) or (12) include (Exemplary Compound No. 1) to (Exemplary Compound No. 18) shown below. N in the specific examples is an integer of 2 or more.

  The specific polyurethane resin (urethane binder) used when used as the photopolymerizable photosensitive layer of the lithographic printing plate precursor according to the invention is a polyurethane resin further having a carboxyl group. As the specific polyurethane resin suitably used, a structural unit represented by at least one diol compound of formulas (13), (14), and (15) and / or tetracarboxylic dianhydride may be used as a diol compound. Examples thereof include polyurethane resins having a structural unit derived from a ring-opened compound.

In the above formula, R ² is a hydrogen atom, a substituent (for example, a halogen atom such as a cyano group, a nitro group, —F, —Cl, —Br, —I, etc., —CONH ₂ , —COOR ³ , —OR ³ , — Each group includes NHCONHR ³ , —NHCOOR ³ , —NHCOR ³ , —OCONHR ³ (wherein R ³ represents an alkyl group having 1 to 10 carbon atoms and an aralkyl group having 7 to 15 carbon atoms). An alkyl group, an aralkyl group, an aryl group, an alkoxy group, or an aryloxy group, which may have a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, and an aryl group having 6 to 15 carbon atoms. Show. L ⁷ , L ⁸ and L ⁹ may be the same or different and may have a single bond or a substituent (for example, alkyl, aralkyl, aryl, alkoxy and halogeno groups are preferred). A divalent aliphatic or aromatic hydrocarbon group, preferably an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 15 carbon atoms, more preferably an alkylene group having 1 to 8 carbon atoms. . If necessary, L ⁷ , L ⁸ , and L ⁹ may have other functional groups that do not react with isocyanate groups, such as carbonyl, ester, urethane, amide, ureido, and ether groups. A ring may be formed by 2 or 3 of R ² , L ⁷ , L ⁸ and L ⁹ .
Ar represents a trivalent aromatic hydrocarbon group which may have a substituent, preferably an aromatic group having 6 to 15 carbon atoms.

C) Diol compound containing a carboxyl group Specific examples of the diol compound having a carboxyl group represented by the formula (13), (14) or (15) include those shown below.
3,5-dihydroxybenzoic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (2-hydroxyethyl) propionic acid, 2,2-bis (3-hydroxypropyl) propionic acid, Bis (hydroxymethyl) acetic acid, bis (4-hydroxyphenyl) acetic acid, 2,2-bis (hydroxymethyl) butyric acid, 4,4-bis (4-hydroxyphenyl) pentanoic acid, tartaric acid, N, N-dihydroxyethylglycine N, N-bis (2-hydroxyethyl) -3-carboxy-propionamide and the like.

  In the present invention, preferred tetracarboxylic dianhydrides used for the synthesis of the specific polyurethane resin include those represented by the formulas (16), (17), and (18).

In the formula, L ¹⁰ is a divalent aliphatic or aromatic hydrocarbon which may have a single bond or a substituent (eg, alkyl, aralkyl, aryl, alkoxy, halogeno, ester, amide groups are preferred). Group, —CO—, —SO—, —SO ₂ —, —O— or —S—, preferably a single bond, a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms, —CO—, —SO ₂ —, —O— or —S— is shown. R ⁴ and R ⁵ may be the same or different and each represents a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, an alkoxy group or a halogeno group, preferably a hydrogen atom or an alkyl having 1 to 8 carbon atoms. Group, an aryl group having 6 to 15 carbon atoms, an alkoxy group having 1 to 8 carbon atoms or a halogeno group. Two of L ¹⁰ , R ⁴ and R ⁵ may be bonded to form a ring.

R ⁶ and R ⁷ may be the same or different and each represents a hydrogen atom, an alkyl group, an aralkyl group, an aryl group or a halogeno group, preferably a hydrogen atom, an alkyl having 1 to 8 carbon atoms, or a carbon number 6-15 aryl groups are shown. Two of L ¹⁰ , R ⁶ and R ⁷ may combine to form a ring. L ¹¹ and L ¹² may be the same or different and each represents a single bond, a double bond or a divalent aliphatic hydrocarbon group, preferably a single bond, a double bond or a methylene group. A represents a mononuclear or polynuclear aromatic ring. An aromatic ring having 6 to 18 carbon atoms is preferable.

Specific examples of the compound represented by the formula (16), (17) or (18) include those shown below.
That is, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride, 2, 3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,4′-sulfonyldiphthalic dianhydride, 2,2-bis (3 , 4-Dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 4,4 ′-[3,3 ′-(alkylphosphoryldiphenylene) -bis (iminocarbonyl) ] Diphthalic dianhydride,

Aromatic tetracarboxylic dianhydrides such as adducts of hydroquinone diacetate and trimetic anhydride, diacetyldiamine and trimetic anhydride; 5- (2,5-dioxotetrahydrofuryl) -3-methyl- 3-cyclohexsi-1,2-dicarboxylic acid anhydride (Dainippon Ink Chemical Co., Ltd., Epicron B-4400), 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1, Alicyclic tetracarboxylic dianhydrides such as 2,4,5-cyclohexanetetracarboxylic dianhydride and tetrahydrofuran tetracarboxylic dianhydride; 1,2,3,4-butanetetracarboxylic dianhydride, 1 Aliphatic tetracarboxylic dianhydrides such as 2,4,5-pentanetetracarboxylic dianhydride.

Examples of a method for introducing a structural unit derived from a compound obtained by ring-opening these tetracarboxylic dianhydrides with a diol compound into a polyurethane resin include the following methods.
a) A method of reacting an alcohol-terminated compound obtained by ring-opening tetracarboxylic dianhydride with a diol compound and a diisocyanate compound.
b) A method of reacting an alcohol-terminated urethane compound obtained by reacting a diisocyanate compound under an excess of a diol compound with tetracarboxylic dianhydride.

Specific examples of the diol compound used at this time include the following compounds.
That is, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol, 1,3-butylene glycol, 1,6-hexanediol, 2-butene- 1,4-diol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-bis-β-hydroxyethoxycyclohexane, cyclohexanedimethanol, tricyclodecane dimethanol, hydrogenated bisphenol A, hydrogenated Bisphenol F, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, bisphenol F ethylene oxide adduct, bisphenol F pro Renoxide adduct, hydrogenated bisphenol A ethylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct, hydroquinone dihydroxyethyl ether, p-xylylene glycol, dihydroxyethyl sulfone, bis (2-hydroxyethyl) -2, Examples include 4-tolylene dicarbamate, 2,4-tolylene-bis (2-hydroxyethylcarbamide), bis (2-hydroxyethyl) -m-xylylenedicarbamate, and bis (2-hydroxyethyl) isophthalate.

D) Other diol compounds Furthermore, in the synthesis of the specific polyurethane resin, other diol compounds which do not have a carboxyl group and may have other substituents which do not react with isocyanate can be used in combination.
Examples of such diol compounds include those shown below.

^{HO-L 13 -O-CO-} L 14 -CO-O-L 13 -OH (19)
^{HO-L 14 -CO-O-} L 13 -OH (20)

In the formula, L ¹³ and L ¹⁴ may be the same or different, and each may be a substituent (for example, an alkyl group, an aralkyl group, an aryl group, an alkoxy group, an aryloxy group, -F, -Cl, -Br, -I A divalent aliphatic hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic group, which may have a group such as a halogen atom. If necessary, L ¹³ and L ¹⁴ may have another functional group that does not react with an isocyanate group, such as a carbonyl group, an ester group, a urethane group, an amide group, or a ureido group. Note that L ¹³ and L ¹⁴ may form a ring.

  Specific examples of the compound represented by the above formula (19) or (20) include (Exemplary Compound No. 19) to (Exemplary Compound No. 35) shown below.

  Also, diol compounds represented by the following formulas (21) and (22) can be preferably used.

In the formula, R ⁸ and R ⁹ may be the same or different and each is an alkyl group which may have a substituent, and c represents an integer of 2 or more, preferably an integer of 2 to 100.

Specific examples of the diol compound represented by the formulas (21) and (22) include those shown below.
That is, as the formula (21), ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1, Examples of the formula (22) such as 8-octanediol include the compounds shown below.

  Moreover, the diol compound shown by following formula (23) and Formula (24) can also be used conveniently.

^{HO-L 15 -NH-CO-} L 16 -CO-NH-L 15 -OH (23)
^{HO-L 16 -CO-NH-} L 15 -OH (24)

In the formula, L ¹⁵ and L ¹⁶ may be the same as or different from each other, and each may have a substituent (for example, alkyl, aralkyl, aryl, alkoxy, aryloxy, halogen atom (—F, —Cl, —Br, —I), A divalent aliphatic hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic group which may have a group. If necessary, L ¹⁵ and L ¹⁶ may have another functional group that does not react with an isocyanate group, for example, carbonyl, ester, urethane, amide, ureido group and the like. A ring may be formed by L ¹⁵ and L ¹⁶ .

  Specific examples of the compound represented by formula (23) or (24) include those shown below.

  Furthermore, diol compounds represented by the following formulas (25) and (26) can also be suitably used.

^{HO-Ar 2 - (L 17} -Ar 3) n-OH (25)
^{HO-Ar 2 -L 17 -OH (} 26)

In the formula, L ¹⁷ represents a divalent aliphatic hydrocarbon group which may have a substituent (eg, alkyl, aralkyl, aryl, alkoxy, aryloxy and halogeno groups are preferable). If necessary, L ¹⁷ may have another functional group that does not react with an isocyanate group, such as an ester, urethane, amide, or ureido group. Ar ² and Ar ³ may be the same or different and each represents a divalent aromatic hydrocarbon group which may have a substituent, preferably an aromatic group having 6 to 15 carbon atoms. n represents an integer of 0 to 10.

Specific examples of the diol compound represented by the above formula (25) or (26) include those shown below.
That is, catechol, resorcin, hydroquinone, 4-methylcatechol, 4-t-butylcatechol, 4-acetylcatechol, 3-methoxycatechol, 4-phenylcatechol, 4-methylresorcin, 4-ethylresorcin, 4-t-butyl Resorcin, 4-hexyl resorcin, 4-chloro resorcin, 4-benzyl resorcin, 4-acetyl resorcin, 4-carbomethoxy resorcin, 2-methyl resorcin, 5-methyl resorcin, t-butyl hydroquinone, 2,5-di- t-butylhydroquinone, 2,5-di-t-amylhydroquinone, tetramethylhydroquinone, tetrachlorohydroquinone, methylcarboaminohydroquinone, methylureidohydroquinone, methylthiohydroquinone, benzonor Runen-3,6-diol, bisphenol A,

Bisphenol S, 3,3′-dichlorobisphenol S, 4,4′-dihydroxybenzophenone, 4,4′-dihydroxybiphenyl, 4,4′-thiodiphenol, 2,2′-dihydroxydiphenylmethane, 3,4-bis (P-hydroxyphenyl) hexane, 1,4-bis (2- (p-hydroxyphenyl) propyl) benzene, bis (4-hydroxyphenyl) methylamine, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,5-dihydroxyanthraquinone, 2-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, 2-hydroxy-3,5-di-t-butylbenzyl alcohol, 4 -Hydroxy-3,5-di-t- Chill benzyl alcohol, 4-hydroxy phenethyl alcohol, 2-hydroxyethyl-4-hydroxybenzoate, 2-hydroxyethyl-4-hydroxyphenyl acetate, resorcinol mono-2-hydroxyethyl ether.
Diol compounds represented by the following formula (27), formula (28) or formula (29) can also be suitably used.

In the formula, R ¹⁰ is a hydrogen atom, a substituent (for example, cyano, nitro, halogen atom (—F, —Cl, —Br, —I), —CONH ₂ , —COOR ^ll , —OR ¹¹ , —NHCONHR ¹¹ , Each group includes —NHCOOR ^ll , —NHCOR ¹¹ , —OCONHR ¹¹ , —CONHR ¹¹ (wherein R ¹¹ represents an alkyl group having 1 to 10 carbon atoms and an aralkyl group having 7 to 15 carbon atoms). .) May be an alkyl, aralkyl, aryl, alkoxy, or aryloxy group, preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group having 6 to 15 carbon atoms. L ¹⁸ , L ¹⁹ and L ²⁰ may be the same or different from each other and may have a single bond or a substituent (for example, alkyl, aralkyl, aryl, alkoxy and halogen groups are preferred). A divalent aliphatic or aromatic hydrocarbon group, preferably an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 15 carbon atoms, more preferably an alkylene group having 1 to 8 carbon atoms. . If necessary, L ¹⁸ , L ¹⁹ , and L ²⁰ may have other functional groups that do not react with isocyanate groups, such as carbonyl, ester, urethane, amide, ureido, and ether groups. ^{Incidentally, R 10, L 18, L} 19, may form a ring, two or three of L ^20. Ar represents a trivalent aromatic hydrocarbon group which may have a substituent, preferably an aromatic group having 6 to 15 carbon atoms. Z ₀ represents the following group.

Here, R ¹² and R ¹³ may be the same or different and each represents a hydrogen atom, sodium, potassium, an alkyl group or an aryl group, preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a carbon atom 6 to 15 aryl groups are shown.

The diol compound having the phosphonic acid, phosphoric acid and / or ester group thereof represented by the formula (27), (28) or (29) is synthesized, for example, by the method shown below.
After protecting the hydroxy group of the halogen compound represented by the following general formulas (30), (31), and (32) as necessary, phosphonate esterification is performed by the Michaelis-Arbuzov reaction represented by the formula (33). If necessary, synthesis is performed by hydrolysis with hydrogen bromide or the like.

In the formula, R ¹⁴ , L ²¹ , L ²² , L ²³ and Ar are as defined in the formulas (27), (28) and (29). R ¹⁵ represents an alkyl group or an aryl group, preferably an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 15 carbon atoms. R ¹⁶ is a residue excluding X ¹ in formulas (30), (31), and (32), and X ¹ represents a halogen atom, preferably Cl, Br, or I.

  Further, synthesis is performed by a method of hydrolysis after reaction with phosphorus oxychloride represented by the formula (34).

In the formula, R ¹⁷ has the same meaning as in formula (33), and M represents a hydrogen atom, sodium or potassium.

  When the polyurethane resin of the present invention has a phosphonic acid group, a diol having a diisocyanate compound represented by the general formula (4) and a phosphonic acid ester group represented by the formula (27), (28), or (29) It may be synthesized by reacting a compound to form a polyurethane resin, followed by hydrolysis with hydrogen bromide or the like.

Further, the amino group-containing compounds represented by the following general formulas (35) and (36) are reacted with the diisocyanate compound represented by the general formula (4) in the same manner as the diol compound to form a urea structure to form a polyurethane resin. It may be incorporated into the structure.

In the formula, R ¹⁸ and R ¹⁹ may be the same or different, such as a hydrogen atom, a substituent (for example, alkoxy, halogen atom (—F, —Cl, —Br, —I), ester, carboxyl group, etc. Each group is included) may be an alkyl, aralkyl or aryl group which may have a hydrogen atom, preferably an alkyl or carbon having 1 to 8 carbon atoms which may have a carboxyl group as a substituent. 6 to 15 aryl groups are shown. L ²⁴ has a substituent (for example, each group such as alkyl, aralkyl, aryl, alkoxy, aryloxy, halogen atom (—F, —Cl, —Br, —I), carboxyl group, etc.). And a divalent aliphatic hydrocarbon group, aromatic hydrocarbon group or heterocyclic group. If necessary, L ²⁴ may have another functional group that does not react with an isocyanate group, for example, a carbonyl group, an ester group, a urethane group, an amide group, or the like. Two of R ¹⁸ , L ²⁴ and R ¹⁹ may form a ring.

Specific examples of the compounds represented by the general formulas (35) and (36) include those shown below.
That is, ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, dodecamethylenediamine, propane-1,2-diamine, bis (3-aminopropyl) methylamine, 1 , 3-bis (3-aminopropyl) tetramethylsiloxane, piperazine, 2,5-dimethylpiperazine, N- (2-aminoethyl) piperazine, 4-amino-2,2-6,6-tetramethylpiperidine, N Aliphatic diamine compounds such as N, dimethylethylenediamine, lysine, L-cystine, isophoronediamine;

o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-tolylenediamine, benzidine, o-ditoluidine, o-dianisidine, 4-nitro-m-phenylenediamine, 2,5-dimethoxy-p- Such as phenylenediamine, bis- (4-aminophenyl) sulfone, 4-carboxy-o-phenylenediamine, 3-carboxy-m-phenylenediamine, 4,4′-diaminophenyl ether, 1,8-naphthalenediamine, etc. Aromatic diamine compounds;
2-aminoimidazole, 3-aminotriazole, 5-amino-1H-tetrazole, 4-aminopyrazole, 2-aminobenzimidazole, 2-amino-5-carboxytriazole, 2,4-diamino-6-methyl-S -Heterocyclic amine compounds such as triazine, 2,6-diaminopyridine, L-histidine, DL-tryptophan, adenine and the like;

Ethanolamine, N-methylethanolamine, N-ethylethanolamine, 1-amino-2-propanol, 1-amino-3-propanol, 2-aminoethoxyethanol, 2-aminothioethoxyethanol, 2-amino-2- Methyl-1-propanol, p-aminophenol, m-aminophenol, o-aminophenol, 4-methyl-2-aminophenol, 2-chloro-4-aminophenol, 4-methoxy-3-aminophenol, 4- Hydroxybenzylamine, 4-amino-1-naphthol, 4-aminosalicylic acid, 4-hydroxy-N-phenylglycine, 2-aminobenzyl alcohol, 4-aminophenethyl alcohol, 2-carboxy-5-amino-1-naphthol, Aminoal such as L-tyrosine Lumpur or aminophenol compounds.

  The specific polyurethane resin that can be used in the present invention is synthesized by adding the above-mentioned isocyanate compound and diol compound in an aprotic solvent to a known catalyst having an activity corresponding to the reactivity and heating. The molar ratio of the diisocyanate and diol compound to be used is preferably 0.8: 1 to 1.2: 1. If an isocyanate group remains at the end of the polymer, it is finally treated by treatment with alcohols or amines. In the form in which no isocyanate group remains.

  As the specific polyurethane resin according to the present invention, those having an unsaturated bond at the polymer terminal, main chain, and side chain are also preferably used. By having an unsaturated bond, a crosslinking reaction occurs between the polymerizable compound or the polyurethane resin. As a result, the strength of the photocured product is increased, and when applied to a lithographic printing plate, a plate material having excellent printing durability is obtained. be able to. As the unsaturated bond, a carbon-carbon double bond is particularly preferable because of the ease of the crosslinking reaction.

  As a method for introducing an unsaturated group into the polymer terminal, there are the following methods. That is, when an isocyanate group remains at the polymer terminal in the process of synthesizing the polyurethane resin, an alcohol or amine having an unsaturated group may be used in the process of treating with an alcohol or amine. Specific examples of such compounds include the following.

As a method for introducing an unsaturated group into the main chain or side chain, there is a method of using a diol compound having an unsaturated group for the synthesis of a polyurethane resin. Specific examples of the diol compound having an unsaturated group include the following compounds.
A diol compound represented by formula (37) or (38). Specific examples include the following.

  Specific examples of the diol compound represented by the formula (37) include 2-butene-1,4-diol, and the diol compound represented by the formula (38) includes cis-2-butene-1,4. -Diol, trans-2-butene-1,4-diol, and the like.

  A diol compound having an unsaturated group in the side chain. Specific examples include the compounds shown below.

The specific polyurethane resin according to the present invention preferably contains an aromatic group in the main chain and / or side chain. More preferably, the content of the aromatic group is in the range of 10 to 80% by weight in the polyurethane resin.
Such a specific polyurethane resin is a polyurethane resin having a carboxyl group, and the content thereof is preferably such that the carboxyl group contains 0.4 meq / g or more, more preferably 0.4 to 3.5 meq / g. Range.
Moreover, as molecular weight of specific polyurethane resin, Preferably it is 1000 or more in a weight average molecular weight, More preferably, it is the range of 10,000-300,000.

  The specific polyurethane resin according to the present invention may be used alone or in combination of two or more. Moreover, as long as the effects of the present invention are not impaired, other polymer compounds can be mixed and used in addition to the (A) polyurethane resin. In this case, the other polymer compound is preferably 90% by weight or less, more preferably 70% by weight or less in the total polymer compound including (A) the polyurethane resin.

  The content of the specific polyurethane resin (A) contained in the photosensitive layer of the lithographic printing plate precursor according to the invention is about 5 to 95% by weight, preferably about 10 to 85% by weight in terms of solid content. When the addition amount is less than 5% by weight, the strength of the image portion is insufficient when an image is formed. If the addition amount exceeds 95% by weight, no image is formed.

[(B) Radical polymerizable compound]
The radically polymerizable compound used in the present invention is a radically polymerizable compound having at least one ethylenically unsaturated double bond, from a compound having at least one, preferably two or more terminal ethylenically unsaturated bonds. To be elected. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention.
These have chemical forms such as monomers, prepolymers, i.e. dimers, trimers and oligomers, or mixtures thereof and copolymers thereof.
Examples of monomers and copolymers thereof include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof. In this case, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, or an amide of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound is used. In addition, unsaturated carboxylic acid ester having a nucleophilic substituent such as hydroxyl group, amino group, mercapto group, amide and monofunctional or polyfunctional isocyanate, addition reaction product of epoxy, monofunctional or polyfunctional A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, halogen A substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a group or a tosyloxy group with a monofunctional or polyfunctional alcohol, amine or thiol is also suitable. As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene or the like instead of the unsaturated carboxylic acid.

  Specific examples of the radical polymerizable compound that is an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, and 1,3-butanediol diacrylate. , Tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4- Cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol Triacrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer, etc. is there.

  Methacrylic acid esters include 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-hydroxypro ) Phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

  Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate.

  Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.

  Examples of isocrotonic acid esters 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 aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240, JP-A-59-5241. 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.

  Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like.

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

  In addition, urethane-based addition polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable, and specific examples thereof include, for example, one molecule described in JP-B-48-41708. A vinylurethane compound containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxyl group represented by the following formula (VI) to a polyisocyanate compound having two or more isocyanate groups. Etc.

General formula (VI)
^{_{CH 2 = C (R 41)}} COOCH 2 CH (R 42) OH
(However, R ⁴¹ and R ⁴² represent H or CH _3. )

  Also, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, and JP-B-2-16765, JP-B-58-49860, JP-B-56-17654, Urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418 are also suitable.

  Furthermore, radical 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 may be used.

  Other examples include polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191, JP-B-52-30490, and JP-A-52-30490. Examples thereof include polyfunctional acrylates and methacrylates such as reacted epoxy acrylates. In addition, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337, and JP-B-1-40336, and vinylphosphonic acid compounds described in JP-A-2-25493 can also be exemplified. . In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, those introduced as photocurable monomers and oligomers in Journal of Japan Adhesion Association vol. 20, No. 7, pages 300 to 308 (1984) can also be used.

The radical polymerizable compounds may be used alone or in combination of two or more. For these radically polymerizable compounds, the details of how to use them, such as what structure to use, whether they are used alone or in combination, and how much they are added, can be selected according to the performance design of the final recording material. Can be set.
As for the compounding ratio of the radically polymerizable compound in the photosensitive layer , a larger amount is advantageous in terms of sensitivity. However, when the amount is too large, an undesirable phase separation may occur, or the production process due to the adhesiveness of the image recording layer may occur. Problems (for example, defective transfer due to transfer and adhesion of recording layer components) and precipitation from the developer may occur. From these viewpoints, the preferable blending ratio of the radical polymerizable compound is often 5 to 80% by weight, preferably 20 to 75% by weight, based on the total components of the composition.
As for the method of using the radically polymerizable compound, an appropriate structure, blending, and addition amount can be arbitrarily selected from desired properties, and in some cases, a layer configuration / coating method such as undercoating or overcoating can be carried out.

[(C) Photothermal conversion agent which is a dye having an absorption maximum from a wavelength of 760 nm to 1200 nm ]
Since the photosensitive layer of the lithographic printing plate precursor according to the invention is recorded by heat mode exposure, typically a laser emitting infrared rays, it is essential to use a photothermal conversion agent. The photothermal conversion agent has a function of absorbing light of a predetermined wavelength and converting it into heat. Due to the heat generated at this time, the component (D), that is, the compound that generates radicals by heat mode exposure of light having a wavelength that can be absorbed by the photothermal conversion agent (C) is decomposed to generate radicals. Photothermal conversion agent used in the present invention have a function of converting the absorbed light into heat, having a wavelength of infrared laser used for burning writing, i.e., an absorption maximum at 1200nm wavelength 760 nm, so-called dye fees known as infrared absorbing agent is used.

  As the dye, commercially available dyes and known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes Is mentioned.

  Preferred dyes include, for example, cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-78787, and the like. Methine dyes described in JP-A-58-173696, JP-A-58-181690, JP-A-58-194595, JP-A-58-112793, JP-A-58-224793, JP-A-59- 48187, JP-A 59-73996, JP-A 60-52940, JP-A 60-63744, etc., naphthoquinone dyes, JP-A 58-112792, etc. And cyanine dyes described in British Patent 434,875.

  Also, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) pyrylium salt described in US Pat. No. 3,881,924, Trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59-41363, 59-84248 Nos. 59-84249, 59-146063, 59-146061, pyranlium compounds, cyanine dyes described in JP-A-59-216146, US Pat. No. 4,283,475 The pentamethine thiopyrylium salts described above and the pyrylium compounds disclosed in Japanese Patent Publication Nos. 5-13514 and 5-19702 are also preferably used. .

  Another example of a preferable dye is a near-infrared absorbing dye described in US Pat. No. 4,756,993 as formulas (I) and (II).

  Among these dyes, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes. Further, a cyanine dye is preferable, and a cyanine dye represented by the following general formula (I) is most preferable.

In the general formula (I), X ¹ represents a halogen atom or X ² -L ^1,. Here, X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms. R ¹ and R ² each independently represents 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 that a 6-membered ring is formed.

Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Preferred substituents include hydrocarbon groups having 12 or less carbon atoms, halogen atoms, and alkoxy groups 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 may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxyl groups, and sulfo groups. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred. Z ¹⁻ represents a counter anion. However, Z ^1- is not necessary when any of R ^{1 to} R ⁸ is substituted with a sulfo group. Preferred Z ¹⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, in view of storage stability of the photosensitive layer coating solution. Hexafluorophosphate ions and aryl sulfonate ions.

  Specific examples of cyanine dyes represented by formula (I) that can be suitably used in the present invention are those described in paragraphs [0017] to [0019] of Japanese Patent Application No. 11-310623. Can be mentioned.

Examples of pigments that can be used in combination with the infrared absorbing dye in the present invention include commercially available pigments and the Color Index (CI) manual, “Latest Pigment Handbook” (edited by the Japan Pigment Technical Association, published in 1977), “Latest Pigment”. The pigments described in "Applied Technology" (CMC Publishing, 1986) and "Printing Ink Technology" CMC Publishing, 1984) can be used.

  Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. 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 In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Among these pigments, carbon black is preferable.

  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 with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (eg, silane coupling agent, epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The above-mentioned surface treatment methods are described in “Characteristics and Applications of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.

  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 in the range of 0.1 μm to 1 μm. When the particle diameter of the pigment is less than 0.01 μm, it is not preferable from the viewpoint of the stability of the dispersion in the image-sensitive layer coating solution, 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, or the like can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).

These (C) photothermal conversion agents and other photothermal conversion agents, which are dyes having an absorption maximum at a wavelength of 760 nm to 1200 nm, may be added to the same layer as other components, or a separate layer is provided there. added may be, but when the steel work the lithographic printing plate precursor, the optical density at absorption maximum in the wavelength range of 760nm~1200nm the photosensitive layer, is preferably between 0.1 to 3.0 . When this range is deviated, the sensitivity tends to be low. Since the optical density is determined by the amount of the photothermal conversion agent added and the thickness of the recording layer, the predetermined optical density can be obtained by controlling both conditions. The optical density of the recording layer can be measured by a conventional method. As a measuring method, for example, on a transparent or white support, a recording layer having a thickness appropriately determined in a range where the coating amount after drying is necessary as a lithographic printing plate is formed, and a transmission optical densitometer is used. Examples thereof include a measuring method, a method of forming a recording layer on a reflective support such as aluminum, and measuring a reflection density.

[(D) (C) Compound that generates radicals by heat mode exposure of light having a wavelength that can be absorbed by the photothermal conversion agent]
A compound that generates radicals by heat mode exposure (hereinafter referred to as a radical initiator as appropriate) is used in combination with the (C) photothermal conversion agent, and irradiates light having a wavelength that can be absorbed by the photothermal conversion agent, for example, an infrared laser. It refers to a compound that generates radicals by the light and / or heat energy and initiates and accelerates the polymerization of a radically polymerizable compound having a polymerizable unsaturated group (B). Here, “heat mode exposure” is in accordance with the definition in the present invention.
As the radical initiator, known photopolymerization initiators, thermal polymerization initiators and the like can be selected and used. For example, onium salts, triazine compounds having a trihalomethyl group, peroxides, azo polymerization initiators , Azide compounds, quinonediazides and the like, and onium salts are preferred because of their high sensitivity.

  An onium salt that can be suitably used as a radical initiator in the present invention will be described. Preferred onium salts include iodonium salts, diazonium salts, and sulfonium salts. In the present invention, these onium salts function not as acid generators but as radical polymerization initiators. The onium salt suitably used in the present invention is an onium salt represented by the following general formulas (III) to (V).

In formula (III), Ar ¹¹ and Ar ¹² each independently represent an aryl group having 20 or less carbon atoms, which may have a substituent. Preferred substituents when this aryl group has a substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or a group having 12 or less carbon atoms. An aryloxy group is mentioned. Z ¹¹⁻ represents a counter ion selected from the group consisting of a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, preferably a perchlorate ion, a hexafluorophosphate An ion, and an aryl sulfonate ion.

In the formula (IV), Ar ²¹ represents an aryl group having 20 or less carbon atoms which may have a substituent. Preferred examples of the substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, an aryloxy group having 12 or less carbon atoms, and 12 or less carbon atoms. Examples thereof include an alkylamino group, a dialkylamino group having 12 or less carbon atoms, an arylamino group having 12 or less carbon atoms, or a diarylamino group having 12 or less carbon atoms. Z ^21- represents a counter ion having the same ^meaning as Z ^11- .

In the formula (V), R ³¹ , R ³² and R ³³ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred examples of the substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or an aryloxy group having 12 or less carbon atoms. Z ^31- represents a counter ion having the same ^meaning as Z ^11- .

  In the present invention, specific examples of onium salts that can be suitably used as a radical generator include those described in paragraphs [0030] to [0033] of Japanese Patent Application No. 11-310623. it can.

Further, onium salts represented by general formulas (I) to (IV) described in paragraph numbers [0012] to [0050] of JP-A-9-34110, paragraph number [0016] of JP-A-8-108621. Known polymerization initiators such as the thermal polymerization initiator described in 1) are also preferably used.
The radical initiator used in the present invention preferably has a maximum absorption wavelength of 400 nm or less, and more preferably 360 nm or less. By making the absorption wavelength in the ultraviolet region in this way, the lithographic printing plate precursor can be handled under white light.

[Other ingredients]
In the photosensitive layer of the lithographic printing plate precursor according to the invention, a colorant having a large absorption in the visible light region and different from (C) is used as an image colorant. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (orientated chemistry) Kogyo Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), etc., and JP-A-62-2 And dyes described in No. 293247. In addition, pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide can also be suitably used.

  These colorants are added since it is easy to distinguish the image area from the non-image area after image formation. The amount added is 0.01 to 10% by weight based on the total solid content of the photosensitive layer coating solution.

  In the present invention, it is desirable to add a small amount of a thermal polymerization inhibitor in order to prevent unnecessary thermal polymerization of the radical polymerizable compound during preparation or storage of the image recording material. 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-nitroso-N-phenylhydroxylamine aluminum salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% by weight to about 5% by weight with respect to the weight of the total composition. If necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide may be added to prevent polymerization inhibition due to oxygen, and it may be unevenly distributed on the surface of the photosensitive layer in the course of drying after coating. . The amount of the higher fatty acid derivative added is preferably from about 0.1% to about 10% by weight of the total composition.

  The image recording material in the present invention is mainly used for forming an image recording layer of a lithographic printing plate precursor. In order to increase the processing stability of such an image recording layer with respect to development conditions, Japanese Patent Application Laid-Open No. Sho 62. Nonionic surfactants as described in JP-A Nos. 251740 and 3-208514, and amphoteric surfactants as described in JP-A-59-121044 and JP-A-4-13149 are added. can do.

  Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether and the like.

Specific examples of amphoteric surfactants include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, N-tetradecyl-N, N- Examples include betaine type (for example, trade name Amorgen K, manufactured by Dai-ichi Kogyo Co., Ltd.).
The proportion of the nonionic surfactant and the amphoteric surfactant in the photosensitive layer coating solution is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.

  Furthermore, in the photosensitive layer coating solution according to the present invention, a plasticizer is added as needed to impart flexibility of the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate and the like are used.

  In order to produce a lithographic printing plate precursor using the image recording material of the present invention, the constituent components of the image recording material are usually dissolved in a solvent together with the components necessary for the coating solution and coated on a suitable support. . Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, it is not limited to this. These solvents are used alone or in combination. The concentration of the above components (total solid content including additives) in the solvent is preferably 1 to 50% by weight.

The coating, the coating amount of the image recording layer on the support obtained after drying (solid content) is generally 0.5 to 5.0 g / m ² is preferred. Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating. As the coating amount decreases, the apparent sensitivity increases, but the film characteristics of the image recording layer decrease.

  In the image recording layer coating solution according to the present invention, a surfactant for improving the coating property, for example, a fluorosurfactant described in JP-A-62-170950 may be added. it can. A preferred addition amount is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight, based on the solid content of the material of the entire photosensitive layer.

(Protective layer)
Flat plate printing BanHara plate of the present invention, usually, in order to perform exposure in the air, on the image recording layer containing a photopolymerizable composition, further, it is preferable to provide a protective layer, such a protective layer Desirable properties include low permeability of low molecular weight compounds such as oxygen, good transparency of light used for exposure, excellent adhesion to the recording layer, and easy removal in the development process after exposure In general, water-soluble polymer compounds having relatively excellent crystallinity such as polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic acid are generally used.
In the image recording material of the present invention, as the film forming resin, the specific polyurethane resin having a low dissolved oxygen amount in the film after the coating film is formed and having a high oxygen barrier property from the outside is used. Such a protective layer may not necessarily be provided because it has the advantage of suppressing a decrease in image formability due to polymerization inhibition, but it further enhances the oxygen barrier property from the outside and improves image formability, particularly image strength. The protective layer may be provided for the purpose of increasing the thickness.

(Support)
The support used in the case of forming the flat plate printing plate precursor of the present invention is not particularly limited as long as it is a dimensionally stable plate-like material, e.g., paper, plastic (e.g., polyethylene, polypropylene, Paper laminated with polystyrene, etc.), 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.). These may be a single component sheet such as a resin film or a metal plate, or may be a laminate of two or more materials. For example, a paper or plastic film on which a metal as described above is laminated or vapor-deposited. And laminated sheets of different plastic films.

As the support, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate that has good dimensional stability and is relatively inexpensive is particularly preferable. A suitable aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of different elements, and may be a plastic film on which aluminum is laminated or vapor-deposited. Examples of 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. Particularly suitable aluminum in the present invention is pure aluminum, but completely pure aluminum is difficult to produce in the refining technique, and may contain slightly different elements. Thus, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate made of a publicly known material can be appropriately used.
The aluminum plate has a thickness of about 0.1 to 0.6 mm, preferably 0.15 to 0.4 mm, and particularly preferably 0.2 to 0.3 mm.

Prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution for removing rolling oil on the surface is performed as desired.
The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, and a method of selectively dissolving a surface chemically. This is done by the method of As the mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used.
The aluminum plate roughened in this way can be subjected to an anodizing treatment to enhance the water retention and wear resistance of the surface through an alkali etching treatment and a neutralization treatment, if desired. As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, 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 anodization vary depending on the electrolyte used, and thus cannot be specified in general. In general, however, the electrolyte concentration is 1 to 80% by weight solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / day. dm ² , voltage 1 to 100 V, and electrolysis time 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 anodic oxide coating is less than 1.0 g / m ² , the printing durability is insufficient, or the non-image part of the lithographic printing plate is easily scratched, so that the ink adheres to the scratched part during printing. “Scratches and dirt” are likely to occur.
Such anodizing treatment is applied to the surface used for printing the support of the lithographic printing plate, but an anodized film of 0.01 to 3 g / m ² is also formed on the back surface due to the back of the lines of electric force. It is common to form.

The hydrophilic treatment of the support surface is performed after the anodizing treatment, and conventionally known treatment methods are used. Such hydrophilization treatment is disclosed in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734 and 3,902,734. There are various alkali metal silicate methods (for example, sodium silicate aqueous solution). In this method, the support is immersed in an aqueous sodium silicate solution or electrolytically treated. In addition, disclosed in Japanese Patent Publication No. 36-22063 is potassium fluoride zirconate and U.S. Pat. Nos. 3,276,868, 4,153,461, and 4,689,272. A method of treating with polyvinylphosphonic acid as described above is used.
Among these, a particularly preferred hydrophilic treatment in the present invention is a silicate treatment. The silicate treatment will be described below.

The anodized film of the aluminum plate subjected to the treatment as described above has an alkali metal silicate content of 0.1 to 30% by weight, preferably 0.5 to 10% by weight, and a pH at 25 ° C. of 10 to 13. It is immersed in a certain aqueous solution at 15 to 80 ° C. for 0.5 to 120 seconds, for example. If the pH of the alkali metal silicate aqueous solution is lower than 10, the solution will gel, and if it is higher than 13.0, the oxide film will be dissolved. Examples of the alkali metal silicate used in the present invention include sodium silicate, potassium silicate, and lithium silicate. Examples of the hydroxide used to increase the pH of the alkali metal silicate aqueous solution include sodium hydroxide, potassium hydroxide, and lithium hydroxide. In addition, you may mix | blend alkaline-earth metal salt or a group IVB metal salt with said process liquid. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and water-soluble salts such as sulfate, hydrochloride, phosphate, acetate, oxalate, and borate. Can be mentioned. Examples of Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, potassium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, zirconium tetrachloride, etc. Can do. Alkaline earth metal salts or Group IVB metal salts can be used alone or in combination of two or more. A preferable range of these metal salts is 0.01 to 10% by weight, and a more preferable range is 0.05 to 5.0% by weight.
Since the hydrophilicity on the surface of the aluminum plate is further improved by the silicate treatment, the ink hardly adheres to the non-image area during printing, and the stain performance is improved.

A back coat is provided on the back surface of the support as necessary. As such a backcoat, a coating comprising a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174 A layer is preferably used.
Among these coating layers, silicon alkoxy compounds such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , and Si (OC ₄ H ₉ ) ₄ are available at a low price. The coating layer of the metal oxide provided therefrom is particularly preferred because of its excellent development resistance.

  As described above, a lithographic printing plate precursor can be prepared from the image recording material of the present invention. This lithographic printing plate precursor can be recorded with an infrared laser. Thermal recording with an ultraviolet lamp or a thermal head is also possible. In the present invention, image exposure is preferably performed by a solid-state laser and a semiconductor laser that emit infrared rays having a wavelength of 760 nm to 1200 nm.

  After exposure with an infrared laser, the image recording material of the present invention is preferably developed with water or an alkaline aqueous solution.

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

  Further, when developing using an automatic developing machine, the developer in the developing tank for a long time is added to the developer by adding an aqueous solution (replenisher) that is the same as the developer or higher in alkali strength than the developer. It is known that a large amount of a lithographic printing plate precursor can be processed without replacing the plate. This replenishment method is also preferably applied in the present invention.

  Various surfactants, organic solvents, and the like can be added to the developer and the replenisher as necessary for the purpose of promoting and suppressing developability, dispersing development residue, and improving the ink affinity of the printing plate image area. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Preferred organic solvents include benzyl alcohol. Moreover, addition of polyethylene glycol or a derivative thereof, or polypropylene glycol or a derivative thereof is also preferable. In addition, non-reducing sugars such as arabit, sorbit and mannitol can be added.

  In addition, the developer and replenisher may contain an inorganic salt reducing agent such as hydroquinone, resorcin, sodium sulfite or sodium bisulfite, and organic carboxylic acid, antifoaming agent and hard water softening agent as necessary. It can also be added.

  The printing plate developed using the developer and replenisher described above is post-treated with a desensitizing solution containing washing water, a rinsing solution containing a surfactant and the like, gum arabic and starch derivatives. As the post-treatment when the image recording material of the present invention is used as a printing plate, these treatments can be used in various combinations.

In recent years, automatic developing machines for printing plate materials have been widely used in the plate making and printing industries in order to rationalize and standardize plate making operations. This automatic developing machine is generally composed of a developing unit and a post-processing unit, and includes an apparatus for conveying a printing plate material, processing liquid tanks and a spray device. Each processing liquid pumped up is sprayed from a spray nozzle for development processing. In addition, recently, a method is also known in which a printing plate material is immersed and conveyed in a processing liquid tank filled with a processing liquid by a submerged guide roll or the like. In such automatic processing, each processing solution can be processed while being supplemented with a replenisher according to the processing amount, operating time, and the like. In addition, the electrical conductivity can be detected by a sensor and replenished automatically.
In addition, a so-called disposable processing method in which processing is performed with a substantially unused processing solution can also be applied.

  The lithographic printing plate obtained as described above can be subjected to a printing process after applying a desensitized gum if desired. However, if it is desired to obtain a lithographic printing plate with a higher printing durability, a burning treatment is performed. Is given.

  In the case of burning a lithographic printing plate, before burning, an adjustment as described in JP-B-61-2518, JP-A-55-28062, JP-A-62-31859, JP-A-61-159655 is used. It is preferable to treat with a surface liquid.

As its method, with a sponge or absorbent cotton soaked with the surface-adjusting liquid, it is applied onto a lithographic printing plate, or a printing plate is immersed in a vat filled with the surface-adjusting liquid and applied, Application by an automatic coater is applied. Further, it is more preferable to make the coating amount uniform with a squeegee or a squeegee roller after coating.
In general, the amount of surface-adjusting solution applied is suitably 0.03 to 0.8 g / m ² (dry weight).

  The lithographic printing plate coated with the surface-adjusting liquid is dried if necessary, and then heated to a high temperature with a burning processor (for example, burning processor BP-1300 sold by Fuji Photo Film Co., Ltd.). . In this case, the heating temperature and time are in the range of 180 to 300 ° C. and preferably in the range of 1 to 20 minutes, although depending on the type of components forming the image.

  The burned lithographic printing plate can be subjected to conventional treatments such as washing and gumming as needed, but a surface-conditioning solution containing a water-soluble polymer compound or the like is used. In such a case, a so-called desensitizing treatment such as gumming can be omitted.

  By such processing, the lithographic printing plate obtained from the image recording material of the present invention is applied to an offset printing machine or the like and used for printing a large number of sheets.

Hereinafter, the present invention will be described in more detail with reference to synthesis examples, examples and comparative examples, but the present invention is not limited thereto.
(Synthesis Example 1; polyurethane resin 1)
In a 500 ml three-necked round bottom flask equipped with a condenser and a stirrer, 8.2 g (0.05 mol) of 2,2-bis (hydroxymethyl) butanoic acid, 7.8 g of trimethylolpropane monoallyl ether (0.05 Mol) was dissolved in 100 ml of N, N-dimethylacetamide. To this, 2,4-diphenylmethane diisocyanate 20.0 g (0.08 mol), 1,6-hexamethylene diisocyanate 3.4 g (0.02 mol), dibutyltin dilaurate 0.8. 1 g was added, and the mixture was heated and stirred at 100 ° C. for 8 hours. Then, it diluted with 100 ml of N, N-dimethylformamide and 200 ml of methyl alcohol. The reaction solution was poured into 3 liters of water with stirring to precipitate a white polymer. The polymer was separated by filtration, washed with water, and dried under vacuum to obtain 32 g of polymer.
When the molecular weight was measured by gel permeation chromatography (GPC), the weight average molecular weight (polystyrene standard) was 110,000. Further, the carboxyl group content (acid value) was measured by titration to be 1.33 meq / g.

(Synthesis Example 2; polyurethane resin 21)
2,3-bis (hydroxymethyl) propionic acid 10.3 g (0.077 mol) and 23.0 g (0.023 mol) of polypropylene glycol (weight average molecular weight 1000) were dissolved in 100 ml of N, N-dimethylacetamide. To this, 20.0 g (0.08 mol) of 4,4′-diphenylmethane diisocyanate and 3.4 g (0.02 mol) of hexamethylene diisocyanate were used and reacted and worked up in the same manner as in Synthesis Example 1. 80 g of white polymer was obtained. When the molecular weight was measured by GPC, the weight average (polystyrene standard) was 100,000. Moreover, it was 1.35 meq / g when carboxyl group content (acid value) was measured by titration.

  Hereinafter, in the same manner as in Synthesis Example 1 or Synthesis Example 2, a polyurethane resin (polyurethane resin 1 to polyurethane resin 28) of the present invention was synthesized using the diisocyanate compounds and diol compounds shown in Tables 1 to 5 below. Further, the molecular weight was measured by GPC, and the acid value was measured by titration. The measured results are shown in Tables 1-5.

(Examples 1-5, Comparative Example 1)
[Create support]
A molten metal of JIS A1050 alloy containing 99.5% or more of aluminum and Fe 0.30%, Si 0.10%, Ti 0.02%, and Cu 0.013% was subjected to cleaning treatment and cast. In the cleaning process, a degassing process was performed to remove unnecessary gases such as hydrogen in the molten metal, and a ceramic tube filter process was performed. The casting method was a DC casting method. The solidified 500 mm thick ingot was chamfered 10 mm from the surface and homogenized at 550 ° C. for 10 hours so as not to coarsen the intermetallic compound. Next, after hot rolling at 400 ° C. and intermediate annealing at 500 ° C. for 60 seconds in a continuous annealing furnace, cold rolling was performed to obtain an aluminum rolled plate having a plate pressure of 0.30 mm. By controlling the roughness of the rolling roll, the centerline average surface roughness Ra after cold rolling was controlled to 0.2 μm. Then, it applied to the tension leveler in order to improve planarity.

Next, the surface treatment for making a lithographic printing plate support was performed.
First, in order to remove the rolling oil on the surface of the aluminum plate, degreasing treatment was carried out with a 10% sodium aluminate aqueous solution at 50 ° C. for 30 seconds, and neutralization and smut removal treatment were carried out with a 30% sulfuric acid aqueous solution at 50 ° C. for 30 seconds.

Next, in order to improve the adhesion between the support and the recording layer and to provide water retention to the non-image rear portion, a so-called graining treatment was performed to roughen the surface of the support. While maintaining an aqueous solution containing 1% nitric acid and 0.5% aluminum nitrate at 45 ° C. and flowing an aluminum web through the aqueous solution, an alternating waveform with a current density of 20 A / dm ² and a duty ratio of 1: 1 by an indirect power supply cell Then, electrolytic graining was performed by giving an anode side electric quantity of 240 C / dm ² . Thereafter, etching treatment was performed with a 10% sodium aluminate aqueous solution at 50 ° C. for 30 seconds, and neutralization and smut removal treatment were performed with a 30% sulfuric acid aqueous solution at 50 ° C. for 30 seconds.

Furthermore, in order to improve wear resistance, chemical resistance and water retention, an oxide film was formed on the support by anodic oxidation. An anodized film of 2.5 g / m ² by using a 20% sulfuric acid aqueous solution as an electrolyte at 35 ° C. and carrying out an electrolytic treatment with a direct current of 14 A / dm ² by an indirect power feeding cell while carrying an aluminum web into the electrolyte. It was created.

Thereafter, a silicate treatment was performed to ensure hydrophilicity as a non-image portion of the printing plate. The treatment was carried with a 1.5% aqueous solution of sodium silicate 3 maintained at 70 ° C. so that the contact time of the aluminum web was 15 seconds, and further washed with water. The adhesion amount of Si was 10 mg / m ² . Ra (center line surface roughness) of the support prepared as described above was 0.25 μm.

[Formation of photosensitive layer]
The following photosensitive layer coating solution (P-1) was prepared, applied to the aluminum support obtained as described above using a wire bar, and dried at 115 ° C. for 45 seconds using a hot air dryer. A layer was formed to obtain a lithographic printing plate precursor. The coating amount after drying was in the range of 1.2 to 1.3 g / m ² .
The alkali-soluble resin used in the examples is the specific polyurethane resin (A) obtained in the above synthesis example, and the alkali-soluble resin P-1 used in the comparative example [the following table shows “polymer (P-1)” "and described] is a benzylidene Li methacrylate / methacrylic acid copolymer (polymer compound polymerized molar ratio = 80/20, weight average molecular weight of 100,000).

<Photosensitive layer coating solution (P-1)>
・ Alkali-soluble resin (compound described in Table 6, amount described in Table 6)
・ Dipentaerythritol hexaacrylate (B) 1.00g
・ Infrared absorber "IR-6" (C) 0.08g
・ Iodonium salt “I-1” (D) 0.30 g
・ Victoria Pure Blue Naphthalenesulfonic Acid 0.04g
・ Fluorosurfactant 0.0 lg
(Megafuck F-176, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 9.0g
・ Methanol 10.0g
1-methoxy-2-propanol 8.0g

[exposure]
Each of the obtained lithographic printing plate precursors was subjected to a Trend setter 3244VFS manufactured by Creo equipped with a water-cooled 40 W infrared semiconductor laser under the conditions of an output of 6.5 W, an outer drum rotation speed of 81 rpm, a plate surface energy of 188 mJ / cm ² , and a resolution of 2400 dpi. Exposed. After exposure, the presence or absence of ablation on the plate was visually evaluated. The results are shown in Table 6 above.
As is apparent from Table 6, the planographic printing plates of the examples using the image recording material of the present invention as the photosensitive layer were able to perform recording without causing ablation upon exposure.

(Examples 6 to 10, Comparative Example 2)
The following photosensitive layer coating solution (P-2) was prepared, applied to the aluminum support using a wire bar, and dried at 115 ° C. for 45 seconds with a hot air dryer to obtain a lithographic printing plate precursor. The coating amount after drying was in the range of 1.2 to 1.3 g / m ² . The alkali-soluble resin in Comparative Example 2 is the same polymer (P-1) as that used in Comparative Example 1.
<Photosensitive layer coating solution (P-2)>
Alkali-soluble resin (compound described in Table 7, amount described in Table 7)
・ Dipentaerythritol hexaacrylate (B) 1.00g
・ Infrared absorber "IR-6" (C) 0.08g
・ Iodonium salt “I-1” (D) 0.30 g
・ Victoria Pure Blue Naphthalenesulfonic Acid 0.04g
・ Fluorine-based surfactant 0.01g
(Megafuck F-176, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 9.0g
・ Methanol 10.0g
1-methoxy-2-propanol 8.0g

[exposure]
The resulting lithographic printing plate precursor was exposed with a Trend setter 3244VFS manufactured by Creo equipped with a water-cooled 40 W infrared semiconductor laser under the conditions of an output of 9 W, an outer drum rotation speed of 210 rpm, a plate surface energy of 100 mJ / cm ² , and a resolution of 2400 dpi.
[Development processing]
After the exposure, the film was developed using an automatic processor Stablon 900N manufactured by Fuji Photo Film Co., Ltd. As the developer, a 1: 1 water dilution of DN-3C manufactured by Fuji Photo Film Co., Ltd. was used for both the charging solution and the replenisher. The developing bath temperature was 30 ° C. As the finisher, a 1: 1 water dilution of FN-6 manufactured by Fuji Photo Film Co., Ltd. was used.

[Evaluation of printing durability]
Next, printing was performed using a printing press Lislon manufactured by Komori Corporation. At this time, the number of sheets that can be printed while maintaining a sufficient ink density was measured visually to evaluate the printing durability. The results are also shown in Table 7.
From the results shown in Table 7, the lithographic printing plates of the examples using the image recording material of the present invention as the photosensitive layer have superior printing durability compared to Comparative Example 2 using a known water-insoluble and alkali-soluble resin. It can be seen that

(Examples 11 to 13)
A lithographic printing plate precursor was obtained in the same manner as in Example 1 except that the composition of the photosensitive layer coating solution was changed to the following composition. Laser scanning exposure and development were performed under the same conditions as in Example 1 to obtain a printing plate. Obtained. The printing plate was printed in the same manner as in Example 1, and the sensitivity, printing durability and stain resistance were evaluated. The obtained lithographic printing plate precursor was stored at 60 ° C. for 3 days and stored at 45 ° C. and humidity 75% RH for 3 days, followed by forced aging. Table 8 shows.

<Photosensitive layer coating solution (P-3)>
Polyurethane resin (A) (Compounds listed in Table 8 and amounts listed in Table 8)
Radical polymerizable compound (B) (Compounds listed in Table 8 and amounts listed in Table 8)
・ Infrared absorber "IR-6" (C) 0.08g
・ Iodonium salt “I-1” (D) 0.30 g
・ Victoria Pure Blue Naphthalenesulfonic Acid 0.04g
・ Fluorine-based surfactant 0.01g
(Megafuck F-176, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 9.0g
・ Methanol 10.0g
1-methoxy-2-propanol 8.0g

  From Table 8, the lithographic printing plate using the image recording material of the present invention as the photosensitive layer is free from stains in the non-image area, has excellent printing durability, and is resistant even after storage in a high temperature and high humidity environment. It was found that the printing property and the smearing property of the non-image area were not deteriorated and the stability over time was excellent.

(Examples 14 to 17, Comparative Example 3)
[Create support]
An aluminum plate having a thickness of 0.30 mm was grained using a nylon brush and a 400 mesh Pamiston water suspension wave, and then thoroughly washed with water. Etching was performed by immersing in a 10% by weight aqueous sodium hydroxide solution at 70 ° C. for 60 seconds, washing with running water, neutralizing with 20% by weight nitric acid, and then washing with water. This was subjected to an electrolytic surface roughening treatment in a 1% by weight nitric acid aqueous solution with an electric quantity at the time of anode of 160 coulomb / dm ² using a sinusoidal alternating current under the condition of V _A = 12.7V. The surface roughness measured was 0.6 μm (Ra indication). Subsequently, after dipping in a 30% by weight sulfuric acid aqueous solution and desmutting at 55 ° C. for 2 minutes, the anodized film thickness was 2.7 g / m ² in a 20% by weight sulfuric acid aqueous solution at a current density of 2 A / dm ² . Thus, anodizing treatment was performed for 2 minutes.

[Formation of undercoat layer]
Next, a SG method liquid composition (sol solution) was prepared by the following procedure.
<Sol solution composition>
・ Methanol 130g
・ Water 20g
・ 85% phosphoric acid 16g
・ Tetraethoxysilane 50g
・ 60 g of 3-methacryloxypropyltrimethoxysilane
The sol composition was mixed and stirred. An exotherm was observed in about 5 minutes. After reacting for 60 minutes, the contents were transferred to another container, and 3000 g of methanol was added to obtain a sol solution.

This sol solution was diluted with methanol / ethylene glycol = 9/1 (weight ratio), applied so that the amount of Si on the substrate was 3 mg / m ^2, and dried at 100 ° C. for 1 minute.
The photosensitive layer coating solution (P-4) having the composition shown below is applied onto the above-coated aluminum support using a wire bar on the thus-treated aluminum support, and the hot-air drying apparatus is applied. And dried at 115 ° C. for 45 seconds to obtain a lithographic printing plate precursor. The coating amount after drying was in the range of 1.2 to 1.3 g / m ² . The alkali-soluble resin [described in the following table as “polymer compound (P-2)”] used in Comparative Example 3 is a copolymer shown as “P-2” below.

<Photosensitive layer coating solution (P-4)>
Alkali-soluble resin (compounds listed in Table 9 and amounts listed in Table 9)
Radical polymerizable compound (B) (compounds listed in Table 9, amounts listed in Table 9)
・ Infrared absorber “IR-1” (C) 0.08 g
・ Iodonium salt “I-2” (D) 0.30 g
・ Victoria Pure Blue Naphthalenesulfonic Acid 0.04g
・ Fluorine-based surfactant 0.01g
(Megafuck F-176, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 9.0g
・ Methanol 10.0g
1-methoxy-2-propanol 8.0g

[exposure]
The resulting lithographic printing plate precursor was exposed with a Luxel T-9000CTP manufactured by Fuji Photo Film Co., Ltd. equipped with a multichannel laser head under the conditions of an output of 250 mW per beam, an external drum rotation speed of 800 rpm, and a resolution of 2400 dpi. did.
[Development processing]
After the exposure, the film was developed using an automatic processor Stablon 900N manufactured by Fuji Photo Film Co., Ltd. As the developer, a 1: 8 water dilution of DP-4 manufactured by Fuji Photo Film Co., Ltd. was used for both the charging solution and the replenisher. The developing bath temperature was 30 ° C. As the finisher, a 1: 2 water dilution of GU-7 manufactured by Fuji Photo Film Co., Ltd. was used.

[Evaluation of printing durability and stain resistance]
It was then printed using a Heidelberg SOR-1 KZ printing machine. At this time, the number of sheets that can be printed while maintaining a sufficient ink density was measured, and printing durability was evaluated. Moreover, the stain | pollution | contamination property of a non-image part was visually evaluated about the obtained printed matter. The results are shown in Table 9.
From Table 9, it was found that the lithographic printing plate using the image recording material of the present invention as the photosensitive layer has no stain on the non-image area and is excellent in printing durability.

(Examples 18 to 21)
[Formation of undercoat layer]
The following undercoat liquid was apply | coated to the aluminum support body used in Examples 1-5 with the wire bar, and it dried at 90 degreeC for 30 second using the warm air type dryer. The coating amount after drying was 10 mg / m ² .

[Undercoat liquid]
A molar ratio of ethyl methacrylate to 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt 75:15
Copolymer of lg
・ 2-aminoethylphosphonic acid 0.1g
・ Methanol 50g
・ Ion exchange water 50g

A photosensitive layer coating solution (P-5) having the composition shown below is applied to the aluminum plate thus treated using a wire bar on the undercoated aluminum support, and 115 is heated by a hot air dryer. A lithographic printing plate precursor was obtained by drying at 45 ° C. for 45 seconds. The coating amount after drying was in the range of 1.2 to 1.3 g / m ² .

<Photosensitive layer coating solution (P-5)>
Alkali-soluble resin (compound described in Table 10, amount described in Table 10)
Radical polymerizable compound (B) (Compounds listed in Table 10 and amounts listed in Table 10)
・ Infrared absorber “IR-1” (C) 0.08 g
・ Iodonium salt “I-1” (D) 0.30 g
・ Victoria Pure Blue Naphthalenesulfonic Acid 0.04g
・ Fluorine-based surfactant 0.01g
(Megafuck F-176, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 9.0g
・ Methanol 10.0g
1-methoxy-2-propanol 8.0g

The obtained lithographic printing plate precursor was subjected to exposure and development under the same conditions as in Examples 1 to 5 except that a 1: 4 water dilution of CA-1 manufactured by Fuji Photo Film Co., Ltd. was used as the developer. Then, printing was performed and printing durability was evaluated. The results are shown in Table 10.
From Table 10, it was found that the lithographic printing plate using the image recording material of the present invention as the photosensitive layer is excellent in printing durability.

(Examples 22 to 26)
Next, in the same manner as in Examples 6 to 10, a photosensitive layer was formed on an aluminum support, and a 3% by weight aqueous solution of polyvinyl alcohol (saponification degree: 86.5 to 89 mol%, polymerization degree: 1000) was dried. The lithographic printing plate precursor was prepared by coating at a coating weight of 2 g / m ² and drying at 100 ° C. for 2 minutes to form a protective layer on the photosensitive layer.
The obtained lithographic printing plate precursor was printed under the same conditions as in the printing plates obtained by exposing and developing under the same conditions as in Examples 6 to 10, and the printing durability was evaluated. The results are shown in Table 11.

  From Table 11, it was found that the lithographic printing plate using the image recording material of the present invention as the photosensitive layer is excellent in printing durability, and the effect of improving printing durability can be seen by forming a protective layer.

Claims (5)

On the support, (A) a polyurethane resin having a carboxyl group, insoluble in water and soluble in an alkaline aqueous solution, (B) a radical polymerizable compound, and (C) a dye having an absorption maximum at a wavelength of 760 nm to 1200 nm. A photothermal conversion agent, (D) (C) a compound that generates radicals by heat mode exposure of light having a wavelength that can be absorbed by the photothermal conversion agent, and (E) a colorant different from (C), and heat A negative lithographic printing plate precursor for heat mode, comprising a photosensitive layer capable of recording an image by mode exposure. The (A) polyurethane group having a carboxyl group, insoluble in water, and soluble in an aqueous alkali solution has a carbon-carbon double bond in a side chain. Negative type lithographic printing plate precursor. The negative lithographic printing plate precursor for heat mode according to claim 1 or 2, wherein the (C) photothermal conversion agent which is a dye having an absorption maximum at a wavelength of 760 nm to 1200 nm is a cyanine dye. The cyanine dyes, heat mode corresponding negative-working lithographic printing plate precursor as described in 請 Motomeko 3 you being a compound represented by the following general formula (I).

In the general formula (I), X ¹ represents a halogen atom or X ² -L ¹ . Here, X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms. R ¹ and R ² each independently represent a hydrocarbon group having 1 to 12 carbon atoms, and R ¹ and R ² may be bonded to each other to form a 5-membered ring or a 6-membered ring. Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. 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 may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. Z ¹⁻ represents a counter anion. However, Z ^1- is not necessary when any of R ^{1 to} R ⁸ is substituted with a sulfo group. The compound which produces | generates a radical by the heat mode exposure of the light of the wavelength which the said (D) (C) photothermal conversion agent can absorb is an onium salt, The Claims 1-4 characterized by the above-mentioned. Negative-type planographic printing plate precursor for heat mode.