JP2003191657A - Original plate for lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an original plate for lithographic printing plate with which image plotting can be done by heat or heat mode exposure and which has a favorable printing-out property. <P>SOLUTION: The original plate for a lithographic printing plate with which image plotting can be done by heat or heat mode exposure, has absorption maximum wavelengths in a visible light region, has no substantial absorption in oscillation wavelengths of a laser to be adopted in the heat mode exposure and has a layer containing a thermally decomposing pigment having 250°C or less of the thermally decomposing initiating temperature on a support. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate precursor capable of image drawing by heat or heat mode exposure. The present invention relates to a lithographic printing plate precursor having a printout that can be confirmed in the above.

[0002]

2. Description of the Related Art Conventionally, a lithographic printing plate has been produced by a system in which a lithographic film as an intermediate material is used to expose a printing plate precursor. However, with the rapid progress of digitization in the printing field in recent years, the process of making a printing plate is a computer-to-plate (CTP) system in which digital data input to a computer and edited is directly output to a printing plate master plate. Is changing to. The printing plate precursor for CTP is described in, for example, Non-Patent Document 1 ("Journal of the Printing Society of Japan", 1999, Vol. 36, p.
97-104, 148-163), various methods have been proposed. Among them, lithographic printing plate precursors capable of image drawing by heat or heat mode exposure have been actively studied.

Even in the lithographic printing plate precursor capable of drawing an image by such heat or heat mode exposure, whether or not the lithographic printing plate precursor has been exposed in the printing plate making operation as in the conventional lithographic printing plate precursor. It is important to identify the color of the ink, inspect the image on the printing plate, and identify the color of the ink. In particular, since a printing plate that does not require development has not been developed, the plate inspection property and the distinguishability at the time of mounting the plate on the printing machine are impaired, and a method for compensating for this is required.

As a countermeasure against this, Patent Document 1 (Japanese Patent Laid-Open No. Hei 11)
No. 277927), a photothermal conversion agent, and a compound that generates an acid, a base or a radical by light or heat, and a compound that changes color by interacting with the generated acid, a base or a radical on a support. A printing plate having an optical recording layer, capable of being exposed to an infrared laser, and having an exposure visible image property (printing out) is described.

However, the compounds that generate an acid or a radical, which are preferable for obtaining a print-out image, described in the above-mentioned publication have absorption in the visible region, so that a printing plate using these compounds is exposed before or after exposure. When left in a bright room, it generates acid or radicals, causing discoloration. As a result, there is a problem that the generation of a print-out image during image exposure is hindered, or the generated print-out image becomes unclear while the plate is left standing.

[0006] Japanese Patent Application Laid-Open No. 2001-33953 discloses a photosensitive composition having a recording layer containing an electron-accepting polymer soluble in an alkaline developer and a near infrared absorbing dye on a support. It is described that by irradiating with near-infrared rays, the optical reflection density of the recording layer in the irradiation part is lowered, and the drawn image can be visually confirmed at the end of exposure. However, the dye used in this technique is an electron-donating dye precursor, and it is possible to obtain a printout that is easily visible only in the presence of an electron-accepting polymer. Not a bakeout pigment.

[0007]

[Non-Patent Document 1] "Journal of the Printing Society of Japan", 1999, Vol. 36, p. 97-104, 148-163

[Patent Document 1] Japanese Patent Laid-Open No. 11-277927

[Patent Document 2] Japanese Patent Laid-Open No. 2001-33953

[0008]

DISCLOSURE OF THE INVENTION The present invention is a lithographic printing plate precursor capable of drawing an image by heat or heat mode exposure, which has solved the above problems and has a good printability. An original plate for a printing plate is provided. In particular, the invention provides a lithographic printing plate precursor which has good print-out properties and can be printed after image drawing without processing such as development.

[0009]

The present inventor uses a heat decomposable dye which has an absorption maximum wavelength in the visible light region and has substantially no absorption at the oscillation wavelength of a laser used for heat mode exposure. This enabled us to achieve the above goals. That is, the present invention is as follows.

1. A lithographic printing plate precursor capable of drawing an image by heat or heat mode exposure, having an absorption maximum wavelength in the visible light region and substantially absorbing at the oscillation wavelength of a laser used for heat mode exposure. A lithographic printing plate precursor having a layer containing a thermally decomposable dye having a thermal decomposition initiation temperature of 250 ° C. or lower on a support.

2. 2. The lithographic printing plate precursor as described in 1 above, wherein the lithographic printing plate precursor is a lithographic printing plate precursor that can be directly mounted on a printing machine without post-exposure development processing.

3. A dye having an absorption maximum wavelength in the visible light region, having substantially no absorption at the oscillation wavelength of a laser used for heat mode exposure, and having a thermal decomposition initiation temperature of 250 ° C. or lower is represented by the following general formula (1) or The lithographic printing plate precursor as described in 1 or 2 above, which has a structure represented by (2).

[0013]

[Chemical 2]

However, A, A ', B and B'each independently represent a substituent. Y and Z each represent an atomic group necessary for forming a carbocycle or a heterocycle. E and G each represent an atomic group that completes a conjugated double bond chain. X and X '
Each represent oxygen, NR or C (CN) ₂ , and R represents an alkyl group or an aryl group. L ³ , L ⁴ , L ⁵ , L ⁶
And L ⁷ each represent an optionally substituted methine group, M ^{k +} represents an onium ion, m and n each independently represent 0, 1 or 2, and x and y each independently represent 0 or 1. Where k represents an integer of 1 or more.

In the present invention, in order to obtain the printout, it has an absorption maximum wavelength in the visible light region, has substantially no absorption at the oscillation wavelength of the laser used for heat mode exposure, and has a thermal decomposition starting temperature. A thermally decomposable dye having a temperature of 250 ° C. or lower is used. Therefore, there is no visible light sensitivity, so there is no problem of wearing it in a bright room.
It was essential to obtain a good bakeout in the prior art,
There is no restriction on the combination of the electron-donating dye precursor and the electron-accepting polymer, and good printout can be obtained by combining any of the polymers.

Here, in JP-A-10-337962, an ultraviolet absorbing substance having an absorption maximum at 330 to 430 nm or a dye having an absorption maximum in the visible region on a support, and a dye within the range of 750 to 900 nm. A heat-sensitive recording material is described which has a recording layer containing an ultraviolet absorbing substance or an infrared absorbing substance which reduces the maximum absorption intensity of the dye upon irradiation with a laser having an oscillation wavelength. However, in this heat-sensitive recording material, the maximum absorption intensity of the ultraviolet absorbing substance or dye is reduced by laser irradiation when the infrared absorbing substance and the ultraviolet absorbing substance or the infrared absorbing substance are heated at high temperature for a short time. It is presumed that the ultraviolet absorbing substance or the dye is decomposed by the redox reaction between the dyes. Further, this heat-sensitive recording material is intended for forming a negative or a photomask used for contact exposure on a PS plate, and there is no description regarding a lithographic printing plate. Therefore, this technique does not disclose or suggest any solution to the above-mentioned problem of imparting printout to a lithographic printing plate precursor using a thermally decomposable dye that is decomposed by heat alone as in the present invention.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

The thermally decomposable dye used in the lithographic printing plate precursor of the present invention has an absorption maximum wavelength in the visible light region and does not substantially absorb at the oscillation wavelength of the laser used for heat mode exposure. It is a dye having a thermal decomposition starting temperature of 250 ° C. or lower. The dye having substantially no absorption at the oscillation wavelength of the laser used for heat mode exposure means that a print-out image is formed when the photothermal conversion agent is removed from the layer containing the heat decomposable dye or the layer adjacent to the layer. It is a dye that is impossible to do. That is, in the case of heat mode exposure, the thermally decomposable dye used in the present invention causes decomposition by absorbing the heat generated by the photothermal conversion agent.

The heat-decomposable dye used in the lithographic printing plate precursor of the present invention shows a hue different from that before the decomposition by being thermally decomposed, and due to the change of the hue, it is different from the drawing area of the image forming layer and the non-drawing area. Hue difference occurs in the area, and it is easy to confirm the drawn image. Therefore, good print-out can be obtained regardless of which polymer is used in the image forming layer.

The thermal decomposition start temperature of the thermally decomposable dye used in the present invention means the mass loss or the endothermic heat generated by thermal decomposition when measured by a TG-DTA measuring device at a temperature rising rate of 10 ° C./min. It is the temperature at which observation begins.

As the heat-decomposable dye used in the lithographic printing plate precursor of the present invention, any dye can be used as long as it satisfies the above-mentioned conditions, and is represented by the following general formula (1) or (2). Dyes are particularly preferred.

[0022]

[Chemical 3]

However, A, A ', B and B'each independently represent a substituent. Y and Z each represent an atomic group necessary for forming a carbocycle or a heterocycle. E and G each represent an atomic group that completes a conjugated double bond chain. X and X '
Each represent oxygen, NR or C (CN) ₂ , and R represents an alkyl group or an aryl group. L ³ , L ⁴ , L ⁵ , L ⁶
And L ⁷ each represent an optionally substituted methine group, M ^{k +} represents an onium ion, m and n each independently represent 0, 1 or 2, and x and y each independently represent 0 or 1. Where k represents an integer of 1 or more.

The substituent represented by A, A ', B and B'is, for example, a substituted or unsubstituted straight chain, branched chain or cyclic group having 1 to 18 carbon atoms, preferably 1 to 8 carbon atoms. Alkyl group (for example, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, cyclohexyl, methoxyethyl, ethoxycarbonylethyl, cyanoethyl, diethylaminoethyl, hydroxyethyl, chloroethyl, acetoxyethyl, etc.) , C 7-18, preferably C 7
To 12 substituted or unsubstituted aralkyl groups (eg, benzyl, carboxybenzyl, etc.), C2-C18, preferably C2-C8 alkenyl groups (eg, vinyl), C2-C18, preferably Is an alkynyl group having 2 to 8 carbon atoms (eg, ethynyl, etc.), a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, preferably 6 to 10 carbon atoms (eg, phenyl, 4-methylphenyl, 4-methoxy). Phenyl, 4-carboxyphenyl, 3,5-dicarboxyphenyl, etc.), carbon number 2
To 18, preferably a substituted or unsubstituted acyl group having 2 to 8 carbon atoms (eg, acetyl, propionyl, butanoyl, chloroacetyl, etc.), substituted or unsubstituted having 1 to 18 carbon atoms, preferably 1 to 8 carbon atoms A sulfonyl group (eg, methanesulfonyl, p-toluenesulfonyl, etc.), a sulfinyl group having 1 to 18 carbon atoms, preferably 1 to 8 carbon atoms (eg, methanesulfinyl,
Ethanesulfinyl, octansulfinyl, etc.), an alkoxycarbonyl group having 2 to 18 carbon atoms, preferably 2 to 8 carbon atoms (eg, methoxycarbonyl, ethoxycarbonyl, etc.), 7 to 18 carbon atoms, preferably 7 to 12 carbon atoms Aryloxycarbonyl group (eg, phenoxycarbonyl, 4-methylphenoxycarbonyl, 4-methoxyphenoxycarbonyl, etc.), carbon number 1
To 18, preferably a substituted or unsubstituted alkoxy group having 1 to 8 carbon atoms (eg, methoxy, ethoxy, n
-Butoxy, methoxyethoxy, etc.), 6 to 1 carbon atoms
8, preferably a substituted or unsubstituted aryloxy having 6 to 10 carbon atoms (eg, phenoxy, 4-methoxyphenoxy, etc.), an alkylthio group having 1 to 18 carbon atoms, preferably 1 to 8 carbon atoms (eg, methylthio, Ethylthio, etc.), arylthio having 6 to 10 carbon atoms (eg, phenylthio, etc.), substituted or unsubstituted acyloxy having 2 to 18 carbon atoms, preferably 2 to 8 carbon atoms (eg, acetoxy, ethylcarbonyloxy, cyclohexylcarbonyloxy, Benzoyloxy, chloroacetyloxy, etc.), a substituted or unsubstituted sulfonyloxy having 1 to 18 carbon atoms, preferably 1 to 8 carbon atoms (eg,
Methanesulfonyloxy, etc.), a carbamoyloxy group having 2 to 18 carbon atoms, preferably 2 to 8 carbon atoms (eg, methylcarbamoyloxy, diethylcarbamoyloxy, etc.), 0 to 18 carbon atoms, preferably 0 to 8 carbon atoms A substituted or unsubstituted amino group (for example, unsubstituted amino, methylamino, dimethylamino, diethylamino, anilino, methoxyphenylamino, chlorophenylamino, morpholino, piperidino, pyrrolidino, pyridylamino, methoxycarbonylamino, n-butoxycarbonylamino, Phenoxycarbonylamino, methylcarbamoylamino, phenylcarbamoylamino, ethylthiocarbamoylamino, methylsulfamoylamino, phenylsulfamoylamino, acetylamino, ethylcarbo Arylamino, ethyl thiocarbonylaminoethyl, cyclohexyl carbonylamino, benzoylamino, chloroacetylamino, methanesulfonylamino, benzenesulfonylamino, etc.), a carbon number of 1 1
8, preferably a substituted or unsubstituted carbamoyl group having 1 to 8 carbon atoms (eg, unsubstituted carbamoyl, methylcarbamoyl, ethylcarbamoyl, n-butylcarbamoyl, t-butylcarbamoyl, dimethylcarbamoyl, morpholinocarbamoyl, pyrrolidinocarbamoyl). Etc.), having 0 to 18 carbon atoms, preferably 0 to 8 carbon atoms
Substituted or unsubstituted sulfamoyl group (eg, unsubstituted sulfamoyl, methylsulfamoyl, phenylsulfamoyl, etc.), halogen atom (eg, fluorine, chlorine, bromine, etc.), hydroxyl group, nitro group, cyano group, carboxyl And a heterocyclic group (eg, oxazole, benzoxazole, thiazole, benzothiazole, imidazole, benzimidazole, indolenine, pyridine, sulfolane, furan, thiophene, pyrazole, pyrrole, chroman, coumarin, etc.) and the like.

The substituent represented by A or A ′ is preferably one having a Hammett's substituent constant σp value of 0.2 or more. Hammett's substituent constants are described, for example, in Chem.
Rev. 91, 165 (1991).
Particularly preferable substituents are, for example, a cyano group, a nitro group, an alkoxycarbonyl group, an acyl group, a carbamoyl group, a sulfamoyl group and a sulfonyl group.

The substituent represented by B or B ′ is preferably an alkyl group, an aryl group, an alkoxy group or an amino group.

-C- (E) x-C (= X) bonded to Y
-, And -C = (G) y = C (-X ' ^- )-which is bonded to Z are in a conjugated state, respectively, and therefore, is bonded to Y and this-
Carbocycle or heterocycle represented by C- (E) x-C (= X)-, Z and -C = (G) y = C (-X
The carbocycle or the heterocycle represented by ' ^- )-is considered as one of the resonance structures. Therefore, hereinafter, for convenience, Y and Z and the carbocycle or heterocycle represented by -C-[(E) x and (G) y] -C (= X and X ')-which is bonded thereto will be described. Y and Z and -C-[(E) x and (G) y] -C (= X and X ') bound thereto.
A carbocycle or a heterocycle represented by-is 4, 5,
A 6- or 7-membered ring is preferable, and a 5- or 6-membered ring is particularly preferable. These rings may form a condensed ring with other 4-, 5-, 6-, and 7-membered rings, and these may have a substituent. Examples of the substituent include those shown as the substituents represented by A, A ′, B and B ′. Preferred as a hetero atom forming a heterocycle are B, N, O,
S, Se and Te. Particularly preferred are N, O and S. x and y each independently represent 0 or 1,
It is preferably 0.

X and X'are oxygen, NR and C (C
N) ₂ is represented, but oxygen is preferable.
Y and Z and -C-[(E) x and (G) bound to them
Examples of the carbocycle formed by y] -C (= X and X ')-include the following.

[0029]

[Chemical 4]

Preferred carbocycles are BB-1 and BB-4.

Y and Z and -C-[(E) bound to them
Examples of the heterocycle formed by [x and (G) y] -C (= X and X ')-include the followings.

[0032]

[Chemical 5]

[0033]

[Chemical 6]

Preferred heterocycles are BB-5, BB-6,
BB-7, BB-11, BB-14 and BB-39.

Ra, Rb and Rc independently represent a hydrogen atom or a substituent, and the substituent represented by Ra, Rb or Rc is the same as the substituents represented by A, A ', B and B'. They are synonymous or the substituents are joined together to form a ring. Examples of the ring include a cyclohexane ring and a benzene ring.

The methine groups represented by L ³ , L ⁴ , L ⁵ , L ⁶ and L ⁷ may be the same or different and may be unsubstituted or may have a substituent. The substituent has the same meaning as the substituent represented by A, A ′, B and B ′. Preferred substituents are an alkyl group, an aralkyl group, an aryl group, an alkoxy group, an aryloxy group,
An alkylthio group, an arylthio group, a halogen atom, an amino group, a carbamoyl group, and a heterocyclic group. Further, substituents are linked to each other to form a 5-, 6-, or 7-membered ring (for example, cyclopentene ring, 1-dimethylaminocyclopentene ring, 1-diphenylaminocyclopentene ring, cyclohexene ring, 1
-Chlorocyclohexene ring, isophorone ring, 1-morpholinocyclopentene ring, cycloheptene ring, etc.) may be formed.

Examples of onium represented by M ^{k +} include alkali metal ions such as sodium ion, potassium ion and lithium ion, ammonium ion, anilinium ion, quaternary ammonium ion, oxonium ion, sulfonium ion and phosphonium. An ion, a selenonium ion, an iodonium ion etc. are mentioned. M ^{k +} is preferably not a cyanine dye.

Quaternary ammonium ions are generally tertiary
Primary amines (eg, trimethylamine, triethylamine, tributylamine, triethanolamine, N-methylpyrrolidine, N-methylpiperidine, N, N-dimethylpiperazine, triethylenediamine, N, N, N
′, N′-tetramethylethylenediamine, etc.) or a nitrogen-containing heterocycle (eg, pyridine, picoline, 2, 2 ′)
-Bipyridyl, 4,4'-bipyridyl, 1,10-phenanthroline, quinoline, oxazole, thiazole,
N-alkylimidazole, N-alkylbenzimidazole, pyrazine, tetrazole, N-alkylpiperidine, N-alkylmorpholine and the like) are alkylated, alkenylated, alkynylated or arylated.

K represents an integer, preferably 1 to 10,
It is more preferably 1 to 4. Particularly preferred is 2.

The dyes represented by the above general formulas (1) and (2) are described in JP-A-10-109476 or JP-A-20-109476.
It can be synthesized by the method described in 00-52658.

Specific examples of the heat-decomposable dye used in the present invention are described below, but the present invention is not limited thereto.

[0042]

[Chemical 7]

[0043]

[Chemical 8]

The print-out element using the thermally decomposable dye of the present invention can be applied to various lithographic printing plate precursors capable of image drawing by heat or heat mode exposure. Examples of applicable lithographic printing plate precursors include the following lithographic printing plate precursors.

(1) A specific sulfonimide group, disulfone group or sulfonate group described in JP-A-10-282642, JP-A-10-2826444, JP-A-10-282646 and JP-A-10-282672 is used. A lithographic plate for CTP which contains a lipophilic polymer having a side chain, and which is provided with an image forming layer of a polarity conversion material system in which the polymer is converted to a hydrophilic polymer having a sulfonic acid by heat and / or acid Master plate for printing.

(2) Development processing using a polymer polarity conversion material having a group selected from a carboxylic acid group and a carboxylate group which cause decarboxylation, such as an α-sulfonylacetic acid structure described in JP-A-2000-122272. CTP lithographic printing plate that does not require

(3) When heat is applied to an associative polymer such as a novolac resin as described in JP-B-46-27919 and JP-A-7-285275, the solubility is improved, and the portion to which heat is not applied. A positive-type heat-sensitive lithographic printing plate precursor that utilizes the fact that a positive image is formed by developing with an alkaline aqueous solution because of the difference in solubility between the two.

(4) Infrared absorbing dyes described in JP-A-7-20629 and JP-A-7-271029 which generate heat by absorbing infrared rays, latent Bronsted acids or s-triazine compounds which are acid generators, and crosslinks. It has a resol resin which is an agent, a thermal cross-linking layer whose main component is a novolak resin which is a binder and a polymer to be cross-linked, and after exposure by an infrared laser, the entire plate is heated, and then developed with an alkaline aqueous solution to form a printing plate. Get negative type heat-sensitive lithographic printing plate.

(5) A photosensitive layer in which fine particles of a thermoplastic hydrophobic polymer are dispersed in a hydrophilic resin described in Japanese Patent No. 2938397 is provided on a hydrophilic support and exposed to infrared laser to produce a thermoplastic hydrophobicity. After the fine particles of the polymer are coalesced (fused) by heat to form an image, the plate is directly attached to the printing machine, and the fountain solution and / or the ink is supplied to remove the non-image portion on the printing machine. A lithographic printing plate precursor capable of so-called on-press development.

(6) WO94 / 18005, WO98
/ 40212, WO99 / 19143 and the like, a hydrophilic layer containing a colloid such as silica is provided on the lipophilic layer, and a printing plate-like original plate of the type in which this hydrophilic layer is ablated, or JP 2001-96936 A. And Japanese Patent Application 2000
An on-press development type heat-sensitive lithographic printing plate precursor having a water-soluble or hydrophilic overcoat layer on the hydrophilic layer in order to prevent scattering of ablation debris described in JP-A-276866.

(7) JP 2001-277740 A, JP 2002-046361 A, JP 2002-1375 A.
No. 62, etc., a photosensitive layer in which microcapsules encapsulating a reactive compound are dispersed is provided on a hydrophilic support, the microcapsules are destroyed by infrared laser exposure, and the encapsulating reactive compound is reacted. A lithographic printing plate precursor capable of so-called on-press development, in which after printing an image, the plate is attached to the printing machine as it is, and the fountain solution and / or ink is supplied to remove the non-image portion on the printing machine.

The print-out element using the thermally decomposable dye of the present invention can be suitably used for the lithographic printing plate precursor as described above.
The lithographic printing plate precursor according to any image forming method is applicable as long as it is a lithographic printing plate precursor capable of image drawing by heat or heat mode exposure, and is not limited to the above specific examples.

The heat-decomposable dye used in the present invention can be contained in the image forming layer of the lithographic printing plate precursor. In the case of a lithographic printing plate precursor having a plurality of coating layers, it can be contained in a layer other than the image forming layer such as an ink receiving layer and an overcoat layer.

The content of the heat-decomposable dye used in the present invention is preferably 1% or more, more preferably 3% or more, based on the total solid content of the layer containing the heat-decomposable dye. Good printout can be obtained within this range.

In the lithographic printing plate precursor of the present invention, it is preferable that a layer containing a heat decomposable dye or a layer adjacent to the layer contains a photothermal conversion agent in order to improve sensitivity. The photothermal conversion agent may be any substance that absorbs infrared rays, especially near infrared rays (wavelength 700 to 2000 nm), and various pigments, dyes, and metal fine particles can be used. For example, JP 2001-162960 A, JP 11-235883 A, Journal of the Japan Printing Society, 38-35
The pigments, dyes and fine metal particles described on page 40 (2001) and JP 2001-213062 A are preferably used.

Carbon black is particularly preferred as the pigment. As the metal fine particles, Si, Al, Ti, V, C
r, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr,
Mo, Ag, Au, Pt, Pd, Rh, In, Sn,
Examples thereof include fine particles of W, Te, Pb, Ge, Re and Sb alone or an alloy thereof, or oxides or sulfides thereof. Among them, Re, Sb, Te, Au, Ag, Cu, G
e, Pb and Sn are more preferable, and Ag, Au, Cu,
Sb, Ge and Pb are particularly preferred. As the dye, dyes having a water-soluble group exemplified below are particularly preferable. However, it is not limited to these.

[0057]

[Chemical 9]

[0058]

[Chemical 10]

When the photothermal conversion agent is added to the lipophilic ink-receiving layer or the fine polymer particles to be used, a more lipophilic dye is preferable, and the following dyes are preferable examples.

[0060]

[Chemical 11]

[0061]

[Chemical 12]

The content of the photothermal conversion agent of the pigment and the dye is preferably 0.1 to 50% of the solid content of the containing layer, and 3 to 40%.
Is more preferable. When the metal fine particles are used as the photothermal conversion agent, the content is preferably 5% or more, more preferably 10% or more, of the solid content of the containing layer. Good sensitivity is obtained within this range.

The support used in the present invention is a substrate having a hydrophilic surface or a substrate provided with a hydrophilic surface by coating a hydrophilic layer. Specifically, paper, paper laminated with plastic (eg, polyethylene, polypropylene, 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.), a paper or plastic film laminated or vapor-deposited with the above-mentioned metals, or a substrate on which a hydrophilic layer is applied. Particularly preferred supports include an aluminum plate and a polyester film coated with a hydrophilic layer.

The aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and a slight amount of a foreign element, and further, a thin film of aluminum or an aluminum alloy is laminated with plastic. The foreign elements contained in the aluminum alloy are silicon,
Examples include iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel and titanium. The content of foreign elements in the alloy is at most 10%. Further, the aluminum plate may be an aluminum ingot made by the DC casting method or an ingot made by the continuous casting method.
However, as the aluminum plate applied to the present invention, an aluminum plate of a publicly known and publicly known material can be appropriately used.

The thickness of the above-mentioned support used in the present invention is 0.05 mm to 0.6 mm, preferably 0.1 mm to.
0.4 mm, particularly preferably 0.15 mm to 0.3 mm
Is.

Prior to using the aluminum plate, it is preferable to perform surface treatment such as surface roughening and anodic oxidation. By the surface treatment, it is easy to improve hydrophilicity and ensure adhesiveness with the image forming layer.

The surface roughening treatment of the aluminum plate is carried out by various methods. For example, a method of mechanically roughening the surface, a method of electrochemically melting and roughening the surface and a method of chemically roughening the surface. It is carried out by a method of selective dissolution. As the mechanical method, known methods such as a ball polishing method, a brush polishing method, a blast polishing method and a buff polishing method can be used. As a chemical method, a method of immersing in a saturated aqueous solution of an aluminum salt of a mineral acid as described in JP-A-54-31187 is suitable. Further, as an electrochemical graining method, there is a method of performing alternating current or direct current in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. In addition, JP-A-54-
An electrolytic surface roughening method using a mixed acid as disclosed in No. 63902 can also be used.

The surface roughening by the method as described above is carried out when the center line average roughness (Ra) of the surface of the aluminum plate is 0.2 to 1.
It is preferably applied in the range of 0 μm.

If necessary, the roughened aluminum plate is subjected to alkali etching treatment using an aqueous solution of potassium hydroxide, sodium hydroxide or the like, and further, after being neutralized, in order to enhance abrasion resistance as desired. Is anodized.

As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes forming a porous oxide film can be used, and generally sulfuric acid, hydrochloric acid, oxalic acid, chromic acid or a mixed acid thereof is used. To be The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.

The treatment conditions for anodic oxidation cannot be unconditionally specified because they vary depending on the electrolyte used, but generally, the electrolyte concentration is 1 to 80% solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 5. 60 A / dm ² , voltage 1 to 100 V, electrolysis time 1
A range of 0 seconds to 5 minutes is suitable. The amount of oxide film formed is 1.0 to 5.0 g / m ² , particularly 1.5 to 4.
It is preferably 0 g / m ² .

The support used in the present invention may be a substrate which has been subjected to the above-mentioned surface treatment and has an anodized film as it is, but it has adhesiveness with the upper layer, hydrophilicity, stain resistance, and
To further improve heat insulation, etc.
No. 00-65219 and Japanese Patent Application No. 2000-143387, the expansion treatment of the micropores of the anodic oxide film, the pore sealing treatment of the micropores, the surface hydrophilization treatment immersed in an aqueous solution containing a hydrophilic compound, etc. It can be appropriately selected and performed.

Suitable hydrophilic compounds for the above-mentioned hydrophilic treatment include polyvinylphosphonic acid, compounds having a sulfonic acid group, sugar compounds, citric acid, alkali metal silicates, potassium zirconium fluoride, phosphates / inorganic compounds. A fluorine compound etc. can be mentioned.

When a support having insufficient surface hydrophilicity such as a polyester film is used as the support of the present invention,
It is necessary to make the surface hydrophilic by applying a hydrophilic layer or the like.
As the hydrophilic layer, beryllium, magnesium, aluminum, silicon described in Japanese Patent Application No. 2000-10810,
Titanium, boron, germanium, tin, zirconium,
A hydrophilic layer formed by coating a coating liquid containing a colloid of an oxide or hydroxide of at least one element selected from iron, vanadium, antimony and transition metals is preferable.
Above all, a hydrophilic layer formed by applying a coating liquid containing a colloid of silicon oxide or hydroxide is preferable.

In the present invention, an inorganic undercoat layer such as a water-soluble metal salt of, for example, zinc borate, described in Japanese Patent Application No. 2000-143387, may be optionally added before coating the image-forming layer. Alternatively, an organic undercoat layer containing, for example, carboxymethyl cellulose, dextrin, polyacrylic acid or the like may be provided. Further, this undercoat layer may contain the photothermal conversion agent.

The lithographic printing plate precursor of the invention is image-formed by heat or heat mode exposure. Specifically, direct image-like recording with a thermal recording head, scanning exposure with an infrared laser, high-intensity flash exposure with a xenon discharge lamp, infrared lamp exposure, or the like is used.
YAG, a semiconductor laser that emits near infrared rays of 200 nm
Exposure by a solid high-power infrared laser such as a laser is preferable.

The lithographic printing plate precursor of the present invention can be irradiated with a laser having a laser output of 0.1 to 300 W. When a pulsed laser is used, it is preferable to irradiate a laser having a peak output of 1000 W or higher, preferably 2000 W or higher. The exposure dose in this case is
Surface exposure intensity before modulation by printing image is 0.1 ~ 10J
/ Cm ² is preferable, and 0.3 to 1 J /
More preferably, it is in the range of cm ² . When the support is transparent, it can also be exposed through the support from the back side of the support.

[0078]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

[Production Example of Support] Aluminum of 99.5% or more, Fe 0.30%, Si 0.10%, Ti
JIS A105 containing 0.02% and Cu 0.013%
The molten alloy No. 0 was subjected to a cleaning treatment and cast. For the cleaning treatment, degassing treatment was performed to remove unnecessary gas such as hydrogen in the molten metal, and ceramic tube filter treatment was performed. The casting method was a DC casting method. The solidified ingot having a plate thickness of 500 mm was chamfered by 10 mm from the surface, and homogenized at 550 ° C. for 10 hours so as not to coarsen the intermetallic compound. Then, hot rolling at 400 ° C,
After 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. The center line average surface roughness Ra after cold rolling was controlled to 0.2 μm by controlling the roughness of the rolling roll. Then, a tension leveler was applied to improve the flatness.

Next, a surface treatment was carried out to obtain a support for a lithographic printing plate. First, in order to remove the rolling oil on the surface of the aluminum plate, a 10% sodium aluminate aqueous solution is used at 50 ° C.
Degreasing treatment was performed for 2 seconds, neutralization was performed with a 30% sulfuric acid aqueous solution at 50 ° C. for 30 seconds, and smut removal treatment was performed. Next, in order to improve the adhesion between the support and the heat-sensitive layer and to impart water retention to the non-image area, a so-called graining treatment for roughening the surface of the support was performed. An aqueous solution containing 1% nitric acid and 0.5% aluminum nitrate was kept at 45 ° C., and an aluminum web was flowed in the aqueous solution while a current density of 20 A /
Electrolytic graining was performed by applying 240 C / dm ² on the anode side with an alternating waveform of dm ² and a duty ratio of 1: 1. After that, with a 10% sodium aluminate aqueous solution at 50 ° C
Etching for 30 seconds, 5% with 30% sulfuric acid aqueous solution
Neutralization at 0 ° C. for 30 seconds and smut removal treatment were performed.

Further, in order to improve abrasion resistance, chemical resistance and water retention, an oxide film was formed on the support by anodic oxidation. Anodized film of 2.5 g / m ² is obtained by using a 20% aqueous solution of sulfuric acid 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 supply cell while carrying the aluminum web through the electrolyte. Was produced.

Thereafter, in order to secure hydrophilicity as a non-image area of the printing plate, a silicate treatment was performed. The treatment was carried out by keeping a 1.5% aqueous solution of No. 3 sodium silicate at 70 ° C. so that the contact time of the aluminum web was 15 seconds, and further washing with water.
The amount of attached Si was 10 mg / m ² . Ra (center line average roughness) of the support prepared as described above is 0.25 μm.
Met.

[Preparation of original plate (1) for lithographic printing plate] On the support obtained in the above Preparation Example, the coating solution [A] for image forming layer prepared as described below was applied, and the coating solution [A] for 3 minutes at 80 ° C. After drying, a lithographic printing plate precursor (1) was obtained. The coating weight after drying was 1.
It was 0 g / m ² .

[0084] Image forming layer coating liquid [A]   Positive type polarity conversion polymer compound (the following structural formula) 0.450 g   Infrared absorbing dye (IR-24 described in the present specification) 0.025 g   Pyrolytic dye ((1) described in the present specification) 0.025 g [Thermal decomposition start temperature: 220 ° C, absorption maximum wavelength: 553 nm (methanol)]   Methyl ethyl ketone 3,000g   Acetonitrile 3.000g

[0085]

[Chemical 13]

[Preparation of master plate (2) for lithographic printing plate] On the support obtained in the above Preparation Example, the coating solution [B] for image forming layer prepared as described below was applied, and the mixture was applied at 80 ° C. for 3 minutes. After drying, a lithographic printing plate precursor (2) was obtained. The coating weight after drying was 1.
It was ² g / m ² .

[0087] Image forming layer coating liquid [B]   m, p-cresol novolak (m / p ratio: 6/4) 1.00 g   (Mass average molecular weight 3500, containing unreacted cresol 0.5%)   Photothermal conversion agent (IR-26 described in the present specification) 0.20 g   Pyrolytic dye ((1) described in this specification) 0.05 g   Fluorine-based surfactant 0.05g   (Megafuck F-177, manufactured by Dainippon Ink and Chemicals, Inc.)   γ-butyrolactone 3.00 g   Methyl ethyl ketone 8.00 g   1-methoxy-2-propanol 7.00 g

[Preparation of original plate (3) for lithographic printing plate] On the support obtained in the above Preparation Example, the coating solution [C] for image forming layer prepared as described below was applied, and the mixture was applied at 80 ° C. for 3 minutes. After drying, a lithographic printing plate precursor (3) was obtained. The coating weight after drying was 1.
It was ² g / m ² .

[0089] Image forming layer coating liquid [C]   Negative type polarity conversion polymer compound (the following structural formula) 1.00 g   Infrared absorbing agent (IR-27 described in the present specification) 0.15 g   Pyrolytic dye ((1) described in the present specification) 0.08 g   Fluorosurfactant (MegaFac F-177) 0.05g   Methyl ethyl ketone 20.00 g   Methanol 7.00 g

[0090]

[Chemical 14]

[Preparation of lithographic printing plate precursor (4)] An image forming layer coating solution [D] prepared as described below was coated on the support obtained in the above Preparation Example, and the coating solution at 80 ° C for 3 minutes. After drying, a lithographic printing plate precursor (4) was obtained. The coating weight after drying was 1.
It was 5 g / m ² .

[0092] Image forming layer coating liquid [D]   Novolak resin obtained from phenol and formaldehyde 1.5g     (Alkaline aqueous solution soluble resin having a mass average molecular weight of 10,000)   Infrared absorbing agent (IR-24 described herein) 0.1 g   Pyrolytic dye ((1) described in the present specification) 0.1 g   Acid generator (the following structural formula (a)) 0.5 g   Crosslinking agent (the following structural formula (b)) 0.15 g   Fluorosurfactant (MegaFac F-177) 0.03g   Methyl ethyl ketone 15g   1-methoxy-2-propanol 10g   Methanol 5g

[0093]

[Chemical 15]

[Preparation of Polystyrene Fine Particle Dispersion] 6.0 g of polystyrene, an infrared absorbing agent (IR described in this specification)
-27) 1.5 g and 0.3 g of a thermally decomposable dye ((1) described in the present specification) were dissolved in 18.0 g of a solvent of ethyl acetate / MEK (4/1), and then 4% PVA (manufactured by Kuraray). Two
05) The mixture was mixed with 36 g of the aqueous solution and emulsified with a homogenizer at 10,000 rpm for 10 minutes. afterwards,
Ethyl acetate and MEK with stirring at 60 ° C for 90 minutes
Was evaporated to obtain a polystyrene fine particle dispersion liquid having an average particle diameter of 0.28 μm. The solid content concentration of this dispersion was 12%.

[Preparation of lithographic printing plate precursor (5)] The coating solution [E] for image forming layer prepared as described below was coated on the support obtained in the above-mentioned preparation example, and the coating solution was prepared at 80 ° C for 3 minutes. After drying, a lithographic printing plate precursor (5) was obtained. The coating weight after drying was 0.
It was 8 g / m ² .

[0096] Image forming layer coating liquid [E]   Polystyrene fine particle dispersion 10.0 g   Polyacrylic acid 0.12g   Distilled water 10.0g

[Preparation of lithographic printing plate precursor (6)] The support obtained in the above Preparation Example was coated with the ink receiving layer coating solution prepared as follows, and dried at 80 ° C for 3 minutes. An ink receiving layer was formed. The coating weight after drying is 0.42 g / m
^{Was 2} .

[0098] Ink receiving layer coating liquid   Epicoat 1009 (Epoxy resin, made by Japan Epoxy Resin) 1.2g   Epicoat 1001 (epoxy resin, made by Japan Epoxy Resin) 0.3 g   Infrared absorber (IR-24 described herein) 0.3 g   Pyrolytic dye ((1) described in the present specification) 0.1 g   Methyl ethyl ketone 13.5g   Propylene glycol monomethyl ether 27.0 g

Next, an image forming layer coating solution [F] prepared as described below was applied onto the ink receiving layer, and the temperature was raised to 100 ° C.
And dried for 1 minute to form an image forming layer. The dry coating amount of the image forming layer was 0.40 g / m ² .

[0100] Image forming layer coating liquid [F]   Methanol silica sol (containing 30% of silica particles of 10 to 20 nm)     Colloid consisting of methanol solution, Nissan Chemical Industries) 3.0 g   Polyacrylic acid (mass average molecular weight 250,000, manufactured by Wako Pure Chemical Industries) 0.1 g

Further, an overcoat layer coating solution prepared as described below was applied and dried at 100 ° C. for 1.5 minutes to form an overcoat layer having a dry coating amount of 0.15 g / m ² . . As described above, the lithographic printing plate precursor (6) was obtained.

[0102] Overcoat layer coating solution   Arabia gum 28% aqueous solution 1.5 g   Photothermal conversion agent (IR-10 described in the present specification) 0.042 g   Emamarex # 710 (10% aqueous solution, made by Nippon Emulsion) 0.168 g   Magnesium acetate tetrahydrate (10% aqueous solution, manufactured by Wako Pure Chemical Industries) 0.03 g   Distilled water 30.06g

[Preparation of Master Plate for Lithographic Printing Plate (7)] (Synthesis of Microcapsule Dispersion Liquid) Trimethylolpropane and xylene diisocyanate adduct (Takenate D-manufactured by Mitsui Takeda Chemical Co., Ltd.) as an oil phase component. 110
N) 6.5 g, oligomer of diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., MR-20)
0) 2 g, the following vinyloxy compound 4 g, the following infrared absorbing dye (photothermal conversion agent) 1.5 g, heat decomposable dye ((1) described in the present specification) 0.5 g, and Pionin A-41-C.
0.1 g (manufactured by Takemoto Yushi Co., Ltd.) was dissolved in 12 g of ethyl acetate and 6 g of methyl ethyl ketone. PV as water phase component
40 g of a 4 mass% aqueous solution of A205 was prepared. Mix the above oil phase component and water phase component and use a homogenizer to
Emulsified at 2000 rpm for 10 minutes. The obtained emulsion was added to 25 g of a 1.5% tetraethylenepentamine aqueous solution, and the mixture was stirred at room temperature for 30 minutes and then at 65 ° C. for 3 hours. The solid content concentration of the microcapsule liquid thus obtained was diluted with distilled water so as to be 20% by mass. The average particle size of the obtained dispersion was 0.35 μm.

[0104]

[Chemical 16]

An image forming layer coating solution [G] prepared as described below was applied onto the support obtained in the above Preparation Example and dried at 60 ° C. for 3 minutes to prepare a lithographic printing plate precursor (7). Obtained. The coating weight after drying was 1.0 g / m ² .

[0106] Image forming layer coating liquid [G]   Microcapsule dispersion 10g   0.2 g of the following acid precursor   Megafac F-171 0.05g   (Dainippon Ink and Chemicals, Inc. Fluorine-based surfactant)   Distilled water (added so that the coating solution concentration is 7% by mass)

[0107]

[Chemical 17]

[Preparation of Comparative Lithographic Printing Plate Master Plate (1 ')] A coating liquid obtained by removing the heat-decomposable dye from the image forming layer coating liquid [A] used for preparing the lithographic printing plate master plate (1). A lithographic printing plate precursor for comparison (1 ′) was produced in the same manner as the lithographic printing plate precursor (1) except that the above-mentioned components were used. The coating weight of the image forming layer after drying was 0.95 g / m ² .

[Preparation of lithographic printing plate precursor (2 ') for comparison] A coating liquid obtained by removing the heat-decomposable dye from the image forming layer coating liquid [B] used for preparing the lithographic printing plate precursor (2) was prepared. A lithographic printing plate precursor for comparison (2 ′) was produced in the same manner as the lithographic printing plate precursor (2) except that it was used. The coating weight of the image forming layer after drying was 1.1 g / m ² .

[Preparation of lithographic printing plate precursor (3 ') for comparison] A coating liquid obtained by removing the thermally decomposable dye from the image forming layer coating liquid [C] used for preparing the lithographic printing plate precursor (3) was prepared. A lithographic printing plate precursor for comparison (3 ′) was produced in the same manner as the lithographic printing plate precursor (3) except that it was used. The coating weight of the image forming layer after drying was 1.1 g / m ² .

[Preparation of lithographic printing plate precursor (4 ') for comparison] A coating liquid obtained by removing the thermally decomposable dye from the image forming layer coating liquid [D] used for preparing the lithographic printing plate precursor (4) was prepared. A lithographic printing plate precursor for comparison (4 ′) was produced in the same manner as the lithographic printing plate precursor (4) except that it was used. The coating weight of the image forming layer after drying was 1.5 g / m ² .

[Preparation of lithographic printing plate precursor for comparison (5 ')] Except for using the fine particle dispersion liquid obtained by removing the thermally decomposable dye from the polystyrene fine particle dispersion liquid used for preparing the lithographic printing plate precursor plate (5). A lithographic printing plate precursor for comparison (5 ′) was produced in the same manner as the lithographic printing plate precursor (5). The coating weight of the image forming layer after drying was 0.8 g / m ² .

[Preparation of comparative lithographic printing plate precursor (6 ')] An ink receiving layer coating liquid obtained by removing the heat-decomposable dye from the ink receiving layer coating liquid used for preparing the lithographic printing plate precursor (6) was prepared. A lithographic printing plate precursor for comparison (6 ′) was produced in the same manner as the lithographic printing plate precursor (6) except that it was used. The coating weight of the ink receiving layer after drying was 0.42 g / m ² . The dry coating amount of the image forming layer was 0.40 g / m ² , and the dry coating amount of the overcoat layer was 0.15 g / m ² .

[Preparation of Comparative Lithographic Printing Plate Master Plate (7 ')] A microcapsule dispersion liquid obtained by removing the thermally decomposable dye from the microcapsule dispersion liquid used for preparing the lithographic printing plate master plate (7) was used. A lithographic printing plate precursor for comparison (7 ′) was produced in the same manner as the lithographic printing plate precursor (7) except for the above. The coating weight of the image forming layer after drying was 1.0 g / m ² .

[Examples 1 to 7 and Comparative Examples 1 to 7] Each of the lithographic printing plate precursors prepared as described above was subjected to CreoSite.
It was attached to a trend setter 3244VX manufactured by x company and irradiated with the energy shown in Table 1 to form a latent image. These exposed lithographic printing plate precursors were visually observed, and the printout images were evaluated as good = ◯ and poor = x. Next, among the original plates on which the latent image is formed, (1), (3), (5),
(6), (7), (1 '), (3'), (5 '), (6
Regarding ′) and (7 ′), they were directly attached to a SOR-M printer manufactured by Heidelberg without processing and printed as usual. In addition, the original plate (2), (2
′) Is a developer DP manufactured by Fuji Photo Film Co., Ltd.
-4, an automatic processor equipped with a rinse liquid FR-3 (1: 7) (“PS Processor 90 manufactured by Fuji Photo Film Co., Ltd.”)
0VR "), and printing was performed in the same manner as above. The original plates (4) and (4 ′) on which the latent image was formed were heated in an oven at 140 ° C. for 1 minute and then developed and printed in the same manner as the original plates (2) and (2 ′). The respective results are shown in Table 1.

[0116]

[Table 1]

The lithographic printing plate precursors of Examples all had good print-out, and the drawn images could be clearly confirmed. On the other hand, in each of the lithographic printing plate precursors of Comparative Examples containing no heat-decomposable dye, printout was poor, and it was difficult to clearly confirm the drawn image. Further, the lithographic printing plate precursors of both Examples and Comparative Examples had the same sensitivity and printing durability, and the addition of the heat-decomposable dye did not affect other printing performances.

[0118]

According to the present invention, an image can be drawn by heat or heat mode exposure, and a lithographic printing plate precursor having good printing can be obtained.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09B 23/00 C09B 23/00 LM 69/02 69/02 69/04 69/04 (72) Inventor Naonori Makino Shizuoka 2F025 AA00 AA12 AB03 AC08 AD01 AD03 BH03 CB16 CB41 CC11 CC13 FA10 2H096 AA06 BA01 BA09 CA03 EA04 EA23 2H114 AA04 AA23 BA06 BA10 BA10 DA10 4H056 CA01 CA05 CB01 CC02 CC04 CC05 CC08 CD01 CD02 CD04 CD08 CE02 CE03 CE06 DD16 DD23 DD30

Claims (3)

[Claims] 1. A lithographic printing plate precursor capable of image drawing by heat or heat mode exposure, which has an absorption maximum wavelength in a visible light region and is substantially at an oscillation wavelength of a laser used for heat mode exposure. A lithographic printing plate precursor, which has a layer containing a heat-decomposable dye having a thermal decomposition initiation temperature of 250 ° C. or lower on the support without absorption. 2. The lithographic printing plate precursor according to claim 1, wherein the lithographic printing plate precursor is a lithographic printing plate precursor which can be directly mounted on a printing machine without post-exposure development processing. 3. The lithographic printing plate precursor as claimed in claim 1, wherein the heat decomposable dye has a structure represented by the following general formula (1) or (2). [Chemical 1] However, A, A ′, B and B ′ each independently represent a substituent. Y and Z each represent an atomic group necessary for forming a carbocycle or a heterocycle. E and G each represent an atomic group that completes a conjugated double bond chain. X and X ′ each represent oxygen, N—R or C (CN) ₂ , and R represents an alkyl group or an aryl group. L ³ , L ⁴ , L ⁵ , L ⁶ and L ⁷ each represent an optionally substituted methine group, M ^{k +} represents an onium ion, m and n each independently represent 0,
1 or 2, x and y each independently represent 0 or 1, and k represents an integer of 1 or more.