JP2006084592A - Photosensitive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive composition useful as a recording layer of a positive lithographic printing original plate for an infrared laser having excellent chemical resistance, broad development latitude, and excellent image reproducibility. <P>SOLUTION: The photosensitive composition contains (A) a high molecular compound having a structural unit represented by formula (1) and a phenolic hydroxyl group within a molecule, (B) an acid color-forming dye represented by formula (2), and (C) an infrared absorbent. In the formula (1), R<SP>1</SP>represents H or an arbitrary substituent; X represents a divalent linking group; and R<SP>2</SP>represents a monovalent substituent having an unshared electron pair-bonded moiety and a hydrogen atom capable of hydrogen bond, and capable of forming two or more thermally reversible hydrogen bonds. In the formula (2), the rings A, B and C each represent a mono- to tri-nuclear aromatic hydrocarbon group or aromatic heterocyclic group, and at least one of the rings B and C has at least one substituent selected from the group consisting of amino, alkoxy, aryloxy, alkylthio, and arylthio. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention mainly relates to a photosensitive composition useful for forming a recording layer used in a positive planographic printing plate precursor whose solubility in an alkaline aqueous solution is changed by infrared exposure, and more specifically, based on a digital signal from a computer or the like. The present invention relates to a photosensitive composition having sensitivity to infrared rays, which is useful as a recording layer of a positive lithographic printing plate precursor capable of direct plate making by scanning with an infrared laser beam.

  In recent years, the development of lasers has been remarkable. In particular, solid-state 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.

A positive lithographic printing plate material for an infrared laser, which uses an infrared laser having a light emitting region in the above infrared region as an exposure light source, comprises an alkaline aqueous solution-soluble binder resin and an IR dye that absorbs light and generates heat. It is a lithographic printing plate material that is an essential component. When the infrared laser is exposed to the infrared laser positive lithographic printing plate material, an IR dye or the like in the infrared laser positive lithographic printing plate material is bonded to the binder resin in a non-exposed portion (image portion). The interaction acts as a dissolution inhibitor that substantially lowers the solubility of the binder resin. On the other hand, in the exposed area (non-image area), the IR dye or the like absorbs light and generates heat, so that the interaction between the IR dye or the like and the binder resin is weakened. Therefore, at the time of development, the exposed portion (non-image portion) is dissolved in the alkaline developer, and a lithographic printing plate is formed.
However, in such a positive lithographic printing plate material for infrared laser, compared to a positive lithographic printing plate material made by UV exposure, a resin having high solubility in a solvent such as an alkali developer must be used as a binder resin. Therefore, the resistance to a plate cleaner used when ink adheres during printing is low, and the photosensitive composition is eluted when the plate surface is wiped with the cleaner.

In order to improve the cleaner resistance, a photosensitive composition using a polymer containing a structural unit having a specific functional group capable of forming a hydrogen bond in the photosensitive layer has been proposed (for example, see Patent Document 1). ), It has been reported that cleaner resistance has been improved. However, in such a positive lithographic printing plate precursor for infrared laser, there is a problem that the intensity of the photosensitive layer itself is low, in particular, the influence is exerted on a small area image, and the dot printing durability of the highlight portion is inferior. there were. In addition, the polymers described here have a function of widening the difference in alkali solubilization (discrimination) between exposed and unexposed areas, but the effect is insufficient, and development due to fluctuations in use conditions A technique for further improving the stability (development latitude) of the toner has been desired.
Further, for the purpose of improving discrimination, a technique for adding a specific surfactant to a positive recording layer has been proposed (see, for example, Patent Document 2), but a hydrophilic surfactant is added to the recording layer. By containing it, the surface of the recording layer becomes hydrophilic, and there is a concern that the development resistance of the image area is lowered and the ink deposition property is lowered.
US Pat. No. 6,475,692 JP 2002-122982 A

  The object of the present invention, which has been made to overcome the above-mentioned drawbacks of the prior art, is a photosensitivity that can form a strong film excellent in chemical resistance and alkali development resistance, and can be quickly released from development resistance by infrared exposure. It is an object of the present invention to provide a photosensitive composition useful as a recording layer of a positive lithographic printing plate precursor for an infrared laser having excellent chemical resistance, wide development latitude, and good image reproducibility. .

As a result of intensive studies, the present inventor has found that the above object can be achieved by using a polymer having a specific structural unit and a specific dye together, and has completed the present invention.
That is, the photosensitive composition of the present invention comprises (A) a polymer compound having a structural unit represented by the following general formula (1) and a phenolic hydroxyl group in the molecule, and (B) the following general formula (2). It contains an acid-color-forming dye represented and (C) an infrared absorber.

In the general formula (1), R ¹ represents a hydrogen atom or an arbitrary substituent, X represents a divalent linking group, and R ² represents a hydrogen atom capable of hydrogen bonding with an unshared electron pair binding site. And a monovalent substituent capable of forming two or more thermally reversible hydrogen bonds.

In the general formula (2), ring A, ring B and ring C each independently represent an aromatic hydrocarbon group having 1 to 3 nuclei or an aromatic heterocyclic group, and at least one of ring B and ring C. And at least one substituent selected from the group consisting of an amino group, an alkoxy group, an aryloxy group, an alkylthio group, and an arylthio group. Ring B and ring C may be bonded to each other via a bonding group.
W ¹ represents a carbonyl group, a thiocarbonyl group, or —C (R ²⁵ ) ═N—, wherein R ²⁵ represents a hydrogen atom or a hydrocarbon group, and Q ¹ represents an oxygen atom, a sulfur atom or an imino group. To express. R ^{21 to} R ²⁴ each independently represents a hydrogen atom or a hydrocarbon group. m and n each independently represents 0 or 1.

Although the operation of the present invention is not clear, it is presumed as follows.
In the photosensitive composition of the present invention, not only the excellent chemical resistance of the phenolic resin itself having a hydrogen-bonding substituent in the side chain contained therein, but also hydrogen with an acid-color-forming dye. A strong interaction is formed, and a high dissolution inhibiting function forms a strong and excellent chemical-resistant film. On the other hand, such an interaction is not only easily canceled by exposure or heat, but the coexisting acid-coloring dye generates an acid by decomposition, so that it also functions as a dissolution accelerator and develops. The solubility in the liquid is remarkably improved. Therefore, when such a photosensitive composition is used as a recording layer of a lithographic printing plate precursor, the unexposed area maintains a strong film excellent in chemical resistance and development resistance, and in the exposed area. By releasing the interaction and generating acid, the solubility in the developer is remarkably improved, and the difference in solubility in the alkaline aqueous developer between the unexposed area and the exposed area (discrimination) is dramatically widened to form an image. It is considered that the reproducibility is excellent.

  The photosensitive composition of the present invention can form a strong film excellent in chemical resistance and alkali resistance, and the solubility of the exposed region in the developer is significantly improved by infrared exposure. Therefore, according to the present invention, there is provided a photosensitive composition useful as a recording layer of a positive lithographic printing plate precursor for infrared laser, having excellent chemical resistance, wide development latitude and excellent image reproducibility. Can do.

  The photosensitive composition of the present invention comprises (A) a polymer compound having a structural unit represented by the general formula (1) in the molecule and a phenolic hydroxyl group (hereinafter, appropriately referred to as a modified phenolic resin), ( B) An acid color-forming dye represented by the general formula (2) (hereinafter appropriately referred to as an acid color-forming dye) and (C) an infrared absorber. Hereinafter, each component will be sequentially described.

[(A) Modified phenolic resin]
The modified phenolic resin used in the present invention is characterized by having a structural unit represented by the following general formula (1) and a phenolic hydroxyl group.

In general formula (1), R ¹ represents a hydrogen atom or an arbitrary substituent. The arbitrary substituent referred to here may be any substituent as long as the effects of the present invention due to the structure of “—X—R ² ” described later are not impaired, and the general formula (1 And a plurality of benzene rings may be present. Specific examples include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an allyl group, and the like, but are not limited thereto. Moreover, when two or more exist, each substituent may be the same or different.
X represents a divalent linking group, and preferably represents a divalent linking group having at least one partial structure selected from the group consisting of the following formulas. Here, “having at least one partial structure” means that the linking group represented by X may consist of (1) any one of the following partial structures, and (2) the following partial structures: Or a linking group obtained by linking the linking group of (1) or (2) above with another hydrocarbon group or the like. In the above (2), each of the plurality of partial structures may be the same or different, and the order of connection is also arbitrary. Moreover, the description of the following partial structure does not prescribe | regulate the connection direction of a connection group.

More preferable examples of the linking group include amide, sulfonamide, urea, urethane, thiourea, carbonyl, carboxylic acid ester (—CO—O—), sulfonyl, sulfonic acid ester (—SO ₂ —O—) and the like. Although the structure shown below is mentioned specifically, this invention is not limited to these. Moreover, the description of the following partial structure does not prescribe | regulate the connection direction of a connection group.

R ² is a monovalent substituent which has two or more hydrogen bonds capable of forming a hydrogen bond, and has two or more hydrogen bonds that are thermally reversible, that is, thermally releasable. Represents.
Here, the lone pair binding site refers to a site capable of forming a hydrogen bond with a hydrogen atom capable of hydrogen bonding, which will be described later, specifically, = O, = N-, = S, = P-, Among them, from the viewpoint of forming a stronger hydrogen bond with a hydrogen atom, ═O and ═N— are preferable.

  The hydrogen atom capable of hydrogen bonding refers to an active hydrogen atom capable of hydrogen bonding with the above-mentioned lone pair binding site, specifically, a hydrogen atom, oxygen atom covalently bonded to a nitrogen atom, and Examples include a hydrogen atom that is covalently bonded, a hydrogen atom that is covalently bonded to a sulfur atom, a hydrogen atom that is covalently bonded to a phosphorus atom, and the like. From the viewpoint of formation, a hydrogen atom covalently bonded to a nitrogen atom and a hydrogen atom covalently bonded to an oxygen atom are preferable.

Specific examples of the structure of R ² include structures shown in the following general formulas (R-1) to (R-7). Here, R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom or a hydrocarbon group, and Y represents a hydrocarbon linking group.

  In the present invention, in the film formed using the modified phenolic resin, mainly the above-mentioned lone pair of hydrogen bonding sites and hydrogen atoms capable of hydrogen bonding form thermally reversible hydrogen bonds. Here, the hydrogen bond is not formed between the sites in the same substituent, but is formed between another specific substituent existing in the film. Hereafter, the said coupling | bonding is demonstrated concretely, taking the specific substituent of the specific example (A) of the modified phenolic resin mentioned later as an example.

In the reaction formula 1, the sites corresponding to the lone pair binding site are (= O) and (= N-), and the hydrogen atom corresponding to the hydrogen atom capable of hydrogen bonding is (> N-H). (-H). Since the specific substituent of Reaction Formula 1 has two unshared electron pair binding sites and two hydrogen atoms capable of hydrogen bonding, a total of four hydrogen bonds are formed. In the present invention, it is sufficient that two or more hydrogen bonds are formed. Therefore, one specific substituent has one or more lone pair of hydrogen atoms and one or more hydrogen atoms capable of hydrogen bonding. It will be good.
Thus, since the specific substituent according to the present invention forms two or more hydrogen bonds with other specific substituents, a stable interaction that does not cause a rotational movement of the molecule is formed, which is excellent. It is considered that an effect of improving chemical resistance is obtained. Since this hydrogen bond is thermally reversible, when the photosensitive composition of the present invention is used as a photosensitive layer of a lithographic printing plate precursor, it is easily released by laser exposure or the like during image formation, and developed. The exposed portion (non-image portion) is removed.

  As the modified phenolic resin according to the present invention, any one having a phenolic hydroxyl group in the molecule in addition to the structural unit represented by the general formula (1) can be used. Especially, what introduce | transduced the structural unit represented by the said General formula (1) to a novolak resin, a resole resin, polyhydroxystyrene resin, etc. is preferable.

  In the present invention, it is necessary to have a phenolic hydroxyl group in the molecule together with the general formula (1), but the phenolic hydroxyl group is introduced into the molecule as a structural unit represented by the following general formula (1-2). As the modified phenolic resin (A) of the present invention, in particular, the structural unit represented by the general formula (1) and the structure represented by the general formula (1-2) are as follows: Most preferably, the resin is composed of units.

R < ³ > in General formula (1-2) represents a hydrogen atom or arbitrary substituents each independently. Here, arbitrary substituents are synonymous with R < ¹ > in the said General formula (1), Moreover, multiple may exist with respect to one benzene ring in General formula (1-2), When two or more exist, each substituent may be the same or different.

As a copolymerization ratio of the structural unit represented by the general formula (1) (structural unit (1)) and the structural unit represented by the general formula (1-2) (structural unit (1-2)) From the viewpoint of chemical resistance and sensitivity, the structural unit (1): structural unit (1-2) is preferably in the range of 1:99 to 95: 5, and in the range of 2:98 to 90:10. Is more preferable, and the range of 3:97 to 80:20 is most preferable. The modified phenolic resin may have a copolymer component other than the structural unit (1) and the structural unit (1-2).
Although the structural unit which comprises the modified phenolic resin which concerns on this invention below is shown as a specific example [(A)-(F)] with the polymerization molar ratio, this invention is not limited to these.

(Synthesis method)
The method for synthesizing the modified phenolic resin according to the present invention is not particularly limited. For example, a phenol resin for substituting a part of a hydroxyl group with a specific substituent is used in a solvent with Sn metal as a catalyst. It can be produced by reacting with an isocyanate group (nucleophilic addition reaction) to form a urethane bond.

The nucleophilic addition reaction between the phenoxide of a novolak-type phenol resin for substituting a part of the hydroxyl group with a specific substituent and the isocyanate group-containing compound can be performed as follows. That is, the total weight of the novolak-type phenol resin for substituting a part of the hydroxyl group with a specific functional group is dissolved in a solvent so as to have a concentration of 20 to 80% by mass (preferably 30 to 70% by mass). With respect to the total number of moles of hydroxyl groups of the novolak-type phenol resin, the isocyanate group-containing compound is added so that the mole ratio thereof is a mole ratio to be substituted with a specific functional group, and further, the mole of the isocyanate group-containing compound using Sn metal as a catalyst. It is added under temperature conditions in the range of 10 ° C. to 200 ° C. so that the molar ratio to the number is 0.5 to 5.0% (preferably 1.0 to 2.5), and the number is maintained while maintaining the temperature range. This can be done by stirring for a period of time. In addition, it is preferable that reaction temperature is the range of 20 to 150 degreeC, and it is more preferable that it is the range of 20 to 100 degreeC.
In this case, examples of the solvent used in the above reaction include chloroform, dichloromethane, dimethyl sulfoxide (DMSO), N, N-dimethylformamide (DMF), dimethyl ether (DME), tetrahydrofuran (THF), and the like. Tetrahydrofuran (THF) is preferably used.
As the Sn metal, dibutyltin dilaurate is preferably used.

  The modified phenolic resin according to the present invention preferably has a weight average molecular weight of 200 or more and a number average molecular weight of 200 or more. More preferably, the weight average molecular weight is 500 to 30,000, the number average molecular weight is 500 to 250,000, and the dispersity (weight average molecular weight / number average molecular weight) is 1.1 to 10.

The content of the modified phenolic resin according to the present invention is preferably 40 to 99% by mass with respect to the total solid content of the photosensitive composition, from the viewpoints of sensitivity and durability of the formed film. More preferably, it is 45-95 mass%, and it is most preferable that it is 50-90 mass%.
In the present invention, one or more of the modified phenolic resins can be appropriately mixed and used.

[(B) Acid-coloring dye represented by formula (2)]
In addition to the (A) modified phenolic resin, the photosensitive composition of the present invention is required to contain (B) an acid coloring dye represented by the general formula (2).

In the general formula (2), ring A, ring B and ring C each independently represent an aromatic hydrocarbon group having 1 to 3 nuclei or an aromatic heterocyclic group, and at least one of ring B and ring C. And at least one substituent selected from the group consisting of an amino group, an alkoxy group, an aryloxy group, an alkylthio group, and an arylthio group. Ring B and ring C may be bonded to each other via a bonding group.
W ¹ represents a carbonyl group, a thiocarbonyl group, or —C (R ²⁵ ) ═N—, wherein R ²⁵ represents a hydrogen atom or a hydrocarbon group, and Q ¹ represents an oxygen atom, a sulfur atom or an imino group. To express. R ^{21 to} R ²⁴ each independently represents a hydrogen atom or a hydrocarbon group. m and n each independently represents 0 or 1.

In the acid color-forming dye represented by the general formula (2), as a preferable compound, Q ¹ is an oxygen atom or a sulfur atom, W ¹ is a carbonyl group or a thiocarbonyl group, and ring A is benzene. Ring, piperazine ring, thiophene ring, benzothiophene ring, furan ring, benzofuran ring, indole ring, or pyridine ring, ring B and ring C are each independently a benzene ring or naphthalene ring, and m and n are R ^{21 to} R ²⁴ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an aryl group having 6 to 8 carbon atoms, and R ²⁵ is a hydrogen atom or 1 carbon atom. An alkyl group having 15 to 15 carbon atoms and an aryl group having 6 to 15 carbon atoms. Among them, Q ¹ is an oxygen atom, W ¹ is a carbonyl group, ring A is a benzene ring, and R ^{21 to} R ²⁴ are independently a hydrogen atom, a methyl group, an ethyl group, or a phenyl group. More preferred.

  Moreover, the ring A, the ring B, and the ring C may have a substituent as long as the effects of the present invention are not impaired. Examples of the substituent that can be introduced include a hydroxyl group, a halogen atom, a cyano group, a trimethylsilyloxy group, an alkyl group having 1 to 15 carbon atoms, an acyl group having 2 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, and carbon. C1-C15 alkylthio group, C1-C15 alkylsulfinyl group, C1-C15 alkylsulfonyl group, C6-C15 aryloxy group, C6-C15 arylthio group, C2-C2 ˜15 acyloxy group, C2-C15 alkoxycarbonyl group, amino group, and the like. These substituents may further have a substituent as described above. Among these substituents, a hydroxyl group, a chlorine atom, a bromine atom, a trifluoromethyl group, an alkyl group having 1 to 10 carbon atoms, a phenyl group, a tolyl group, an acyl group having 2 to 5 carbon atoms, and an alkyl group having 2 to 5 carbon atoms. An acyloxy group, a dialkylamino group having 1 to 5 carbon atoms, an alkylamino group having 1 to 5 carbon atoms, a phenylamino group, a phenylmethylamino group, an alkoxy group having 1 to 5 carbon atoms, an alkylthio group having 1 to 5 carbon atoms, Those having a phenoxy group, a phenylthio group and the like are preferable.

Ring B and ring C may be bonded to each other via a bonding group. In this case, examples of the bonding group include an oxygen atom, a sulfur atom, a methylene group, and an ethylene group. It is an oxygen atom.
When ring B and ring C are bonded, m and n are both 0, and ring B and ring C are bonded at the o-position to form a 6-membered ring.
In general formula (2), at least one of ring B and ring C has at least one substituent selected from an amino group, an alkoxy group, an aryloxy group, an alkylthio group, and an arylthio group. Is preferably present in each of ring B and ring C, and each may have two or more. Further, those having at least one amino group in each of ring B and ring C are more preferable.
In addition, the substituent selected from the amino group, alkoxy group, aryloxy group, alkylthio group, and arylthio group mentioned here further has a substituent that can be introduced into the ring A, ring B, and ring C described above. It may be.

  As the acid color-forming dye according to the present invention, a compound having two or more acid color-forming dyes represented by the general formula (2), or a plurality of dyes bonded directly or via a bonding group may be used. . As a method of binding a plurality of acid-coloring dyes, any acid-coloring dyes can be used without particular limitation as long as they are bound directly or via a bonding group.

When the compound having a plurality of acid color-forming dyes is an organic polymer, those having a weight average molecular weight (Mw) of 1,000 to 1,000,000, preferably 1,000 to 500,000, and more preferably 1,000 to 100,000 are preferred. Such an organic polymer substance having a plurality of acid-coloring dyes has a coating property on its own, and a plurality of acid-coloring dyes are localized in the molecule. Are preferably used.
Hereinafter, specific examples of the acid-coloring dyes preferably used in the present invention will be given, but the present invention is not limited thereto.

  The content of the acid coloring dye is 1 to 50% by mass, preferably 3 to 40% by mass, and more preferably 5 to 25% by mass with respect to the total solid content of the photosensitive composition. When the acid color-forming dye is an organic polymer (usually weight average molecular weight Mw = 1000 to 100,000), it is 1 to 95% by weight, preferably 3 to 90% by weight, based on the total solid content of the photosensitive composition. Preferably it contains in the range of 5-80 mass%.

[(C) Infrared absorber]
The infrared absorber contained in the photosensitive composition according to the present invention has a light absorption region in the infrared region of 700 nm or more, preferably 750 to 1200 nm, and has a light / heat conversion ability by light in this wavelength region. Refers to the substance to be expressed. Specifically, various dyes or pigments that absorb light in the wavelength range and generate heat can be used.

  As the dye, commercially available dyes, for example, known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, 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, Examples thereof include oxonol dyes, diimonium dyes, aminium dyes, and croconium dyes.

  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.

  Further, near infrared absorption sensitizers described in US Pat. No. 5,156,938 are also preferably used, and substituted arylbenzo (thio) pyrylium salts described in US Pat. No. 3,881,924 Trimethine thiapyrylium salts described in JP-A Nos. 57-142645 (US Pat. No. 4,327,169), JP-A Nos. 58-181051, 58-220143, 59-41363, 59- 84248, 59-84249, 59-146063, 59-146061, pyrylium compounds, cyanine dyes described in JP-A-59-216146, US Pat. No. 4,283,475 And the pyrylium compounds disclosed in JP-B-5-13514 and JP-A-5-19702 are also preferably used. .

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

  Particularly preferred among these dyes are cyanine dyes, phthalocyanine dyes, oxonol dyes, squarylium dyes, pyrylium salts, thiopyrylium dyes, and nickel thiolate complexes. Furthermore, the dyes represented by the following general formulas (a) to (e) are preferable because of their excellent photothermal conversion efficiency. In this case, it is most preferable because it gives a high interaction with the alkali-soluble resin and is excellent in stability and economy.

In formula (a), X ¹ represents a hydrogen atom, a halogen atom, -NPh _2, X ² -L ¹ or a group shown below. Here, X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an aromatic ring having a hetero atom, or a carbon atom having 1 to 12 carbon atoms including a hetero atom. Indicates a hydrogen group. In addition, a hetero atom here shows N, S, O, a halogen atom, and Se.

In the above formula, Xa ^- has Za described later ^- is defined as for, Ra represents a hydrogen atom, an alkyl group, ant - represents a group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom . R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the recording 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. Moreover, as a preferable substituent, a C12 or less hydrocarbon group, a halogen atom, and a C12 or less alkoxy group are mentioned. 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. Za ⁻ represents a counter anion. However, Za ⁻ is not necessary when the cyanine dye represented by formula (a) has an anionic substituent in the structure and charge neutralization is not necessary. Preferred Za ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, a hexagonal salt, in view of the storage stability of the recording layer coating solution. Fluorophosphate ions and aryl sulfonate ions.

  Specific examples of the cyanine dye represented by formula (a) that can be suitably used in the present invention include those exemplified below, and paragraph numbers [0017] to [0019] of JP-A-2001-133969. And those described in paragraph numbers [0012] to [0038] of JP-A No. 2002-40638 and paragraph numbers [0012] to [0023] of JP-A No. 2002-23360.

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

  Specific examples of the dye represented by formula (b) that can be suitably used in the present invention include those exemplified below.

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

  In the present invention, specific examples of the dye represented by formula (c) that can be suitably used include those exemplified below.

In the general formula (d), R ²⁹ to R ³¹ each independently represents a hydrogen atom, an alkyl group, or an aryl group. R ³³ and R ³⁴ each independently represents an alkyl group, a substituted oxy group, or a halogen atom. n and m each independently represents an integer of 0 to 4. R ²⁹ and R ³⁰ , or R ³¹ and R ³² may be bonded to each other to form a ring, and R ²⁹ and / or R ³⁰ is R ³³ and R ³¹ and / or R ³² is R ³⁴ A ring may be bonded to each other, and when there are a plurality of R ³³ or R ³⁴ , R ³³ or R ³⁴ may be bonded to each other to form a ring. X ² and X ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group, and at least one of X ² and X ³ represents a hydrogen atom or an alkyl group. Q is a trimethine group or a pentamethine group which may have a substituent, and may form a ring structure together with a divalent organic group. Zc ⁻ represents a counter anion and has the same meaning as Za ⁻ in the general formula (a).

  In the present invention, specific examples of the dye represented by the general formula (d) that can be suitably used include those exemplified below.

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

  In the present invention, specific examples of the dye represented by formula (e) that can be suitably used include those exemplified below.

  Examples of the pigment include commercially available pigments or color index (CI) manuals, “Latest Pigment Handbook” (edited by the Japan Pigment Technical Association, published in 1977), “Latest Pigment Applied Technology” (published by CMC, published in 1986), and The pigments described in “Printing Ink Technology” published by CMC (published in 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 polymer-bonded pigments. 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, Indolinone pigments, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, and carbon black can be used.

  These pigments may be used without surface treatment or may be used after surface treatment. As the surface treatment method, a method of surface coating of resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (eg, silane coupling agent, epoxy compound, polyisocyanate) to the pigment surface Etc. The above-mentioned surface treatment methods are described in “Characteristics and Application of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.

  The particle diameter of the pigment is preferably in the range of 0.01 μm to 10 μm from the viewpoint of the stability of the dispersion in the coating solution and the uniformity of the film formed by the photosensitive composition, and is 0.05 μm. More preferably, it is in the range of ˜1 μm, particularly preferably in the range of 0.1 μm to 1 μm.

  As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. Dispersers include ultrasonic dispersers, sand mills, attritors, par mills, super mills, ball mills, impellers, desperzers, KD mills, colloid mills, Dynatrons, three-rollers Lumil, pressure kneader and the like. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).

  These pigments or dyes are from 0.01 to 50% by mass, preferably from 0.1 to 50% by mass, based on the total solid content constituting the photosensitive composition, from the viewpoint of the balance between sensitivity, film uniformity and durability. In the case of 10% by mass, particularly in the case of a dye, 0.5 to 10% by mass, and particularly in the case of a pigment, 0.1 to 10% by mass can be added.

[Lithographic printing plate precursor]
As described above, the photosensitive composition of the present invention is useful as a recording layer of a positive planographic printing plate precursor that can be recorded with an infrared laser. Hereinafter, the case where the photosensitive composition of this invention is used for a recording layer is demonstrated.
[Layer structure of recording layer]
The recording layer of a lithographic printing plate using the photosensitive composition of the present invention can have any of a single layer structure, a phase separation structure, and a multilayer structure.
As the single-layer recording layer, for example, a photosensitive layer described in JP-A-7-285275 and WO 97/39894, and as a phase-separated recording layer, for example, a photosensitive layer described in JP-A-11-44956, As the multi-layer type recording layer, for example, photosensitivity described in JP-A No. 11-218914, US Pat. No. 6,352,812 B1, US Pat. No. 6,352,811 B1, US Pat. No. 6,358,669 B1, US Pat. Although it can be used as a layer, it is not limited to these.
In the case of a multilayer structure, the components (A) to (C) related to the photosensitive composition of the present invention are not limited to the lower layer and the uppermost layer, and may be contained in any layer. (A), (B), a recording layer containing the component (C) in the uppermost layer, or a recording layer containing the components (A) to (C) only in the uppermost layer. From the viewpoint of the effect, it is preferable that the lower layer contains the components (A) and (B).

[Other ingredients]
When the photosensitive composition of the present invention is used for a recording layer of a lithographic printing plate precursor, various compounds are used in combination in the recording layer, if necessary, in addition to the essential components (A) to (C). be able to.

  For example, other alkaline aqueous solution-soluble resins other than (A) the modified phenolic resin can be contained in the photosensitive composition as necessary. In this case, the other alkali-soluble resin is not particularly limited, but a general-purpose novolac resin is preferable.

  Examples of the novolak resin include phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin, phenol / cresol (m-, p-, o-, m- / p -Any of mixing, m- / o-mixing and o- / p-mixing.) Mixed formaldehyde resins are mentioned. These may be used alone or in combination of two or more.

  These novolak resins preferably have a weight average molecular weight of 1,500 or more and a number average molecular weight of 300 or more. More preferably, the weight average molecular weight is 3,000 to 300,000, the number average molecular weight is 500 to 250,000, and the dispersity (weight average molecular weight / number average molecular weight) is 1.1 to 10. .

Moreover, as preferable alkali-soluble resin which can be used together, what has the acidic group mentioned to following (1)-(6) in the principal chain and / or side chain of a polymer | macromolecule is mentioned.
(1) Phenol group (-Ar-OH)
(2) Sulfonamide group (—SO ₂ NH—R)
(3) Substituted sulfonamide acid group (hereinafter referred to as “active imide group”)
[—SO ₂ NHCOR, —SO ₂ NHSO ₂ R, —CONHSO ₂ R]
(4) Carboxylic acid group (—CO ₂ H)
(5) Sulfonic acid group (—SO ₃ H)
(6) Phosphate group (—OPO ₃ H ₂ )
In the above (1) to (6), Ar represents a divalent aryl linking group which may have a substituent, and R represents a hydrogen atom or a hydrocarbon group which may have a substituent. .

  Among the alkali-soluble resins having an acidic group selected from the above (1) to (6), an alkali-soluble resin having (1) a phenol group, (2) a sulfonamide group, and (3) an active imide group is preferable, An alkali-soluble resin having (1) a phenol group or (2) a sulfonamide group is most preferred from the viewpoint of sufficiently ensuring solubility in an alkaline developer, development latitude, and film strength.

As alkali-soluble resin which has an acidic group chosen from said (1)-(6), the following can be mentioned, for example.
(1) Examples of the alkali-soluble resin having a phenol group include a condensation polymer of phenol and formaldehyde, a condensation polymer of m-cresol and formaldehyde, a condensation polymer of p-cresol and formaldehyde, m− / p. -Novolak resins mentioned above such as polycondensates of mixed cresol and formaldehyde, polycondensates of phenol and cresol (m-, p- or m- / p-mixed) and formaldehyde What is included is mentioned, The condensation polymer of pyrogallol and acetone can be mentioned. Furthermore, the copolymer which copolymerized the compound which has a phenol group in a side chain can also be mentioned. Alternatively, a copolymer obtained by copolymerizing a compound having a phenol group in the side chain can also be used.

  Examples of the compound having a phenol group include acrylamide, methacrylamide, acrylic acid ester, methacrylic acid ester, and hydroxystyrene having a phenol group.

  (2) As an alkali-soluble resin having a sulfonamide group, for example, a polymer composed of a minimum constituent unit derived from a compound having a sulfonamide group as a main constituent can be mentioned. Examples of the compound as described above include compounds having at least one sulfonamide group in which at least one hydrogen atom is bonded to a nitrogen atom and one or more polymerizable unsaturated groups in the molecule. Among them, a low molecular compound having an acryloyl group, an allyl group, or a vinyloxy group and a substituted or monosubstituted aminosulfonyl group or a substituted sulfonylimino group in the molecule is preferable. For example, the following general formula (i) to general formula ( and a compound represented by v).

[Wherein, X ¹ and X ² each independently represent —O— or —NR ⁷ . R ¹ and R ⁴ each independently represents a hydrogen atom or —CH ₃ . R ² , R ⁵ , R ⁹ , R ¹² , and R ¹⁶ each independently represent a C 1-12 alkylene group, cycloalkylene group, arylene group, or aralkylene group that may have a substituent. . R ³ , R ⁷ and R ¹³ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group. R ⁶ and R ¹⁷ each independently represents a C 1-12 alkyl group, cycloalkyl group, aryl group or aralkyl group which may have a substituent. R ⁸ , R ¹⁰ and R ¹⁴ each independently represent a hydrogen atom or —CH ₃ . R ¹¹ and R ¹⁵ each independently represent a C 1-12 alkylene group, cycloalkylene group, arylene group or aralkylene group which may have a single bond or a substituent. Y ^1, Y ² represents a single bond or CO independently. ]

  Among the compounds represented by the general formula (i) to the general formula (v), in the resin composition used for the multilayer sensitive material type printing plate precursor of the present invention, in particular, m-aminosulfonylphenyl methacrylate, N- (p -Aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) acrylamide and the like can be preferably used.

  (3) As an alkali-soluble resin having an active imide group, for example, a polymer composed of a minimum constituent unit derived from a compound having an active imide group as a main constituent can be mentioned. Examples of the compound as described above include compounds each having one or more active imide groups represented by the following structural formula and polymerizable unsaturated groups in the molecule.

  Specifically, N- (p-toluenesulfonyl) methacrylamide, N- (p-toluenesulfonyl) acrylamide and the like can be preferably used.

(4) As an alkali-soluble resin having a carboxylic acid group, for example, a minimum structural unit derived from a compound having at least one carboxylic acid group and polymerizable unsaturated group in the molecule is used as a main constituent component. A polymer can be mentioned.
(5) As the alkali-soluble polymer having a sulfonic acid group, for example, a minimum structural unit derived from a compound having at least one sulfonic acid group and a polymerizable unsaturated group in the molecule is a main structural unit. Can be mentioned.
(6) As an alkali-soluble resin having a phosphate group, for example, a minimum structural unit derived from a compound having at least one phosphate group and a polymerizable unsaturated group in the molecule is used as a main constituent component. A polymer can be mentioned.

  The minimum structural unit having an acidic group selected from the above (1) to (6) is not particularly limited to one kind, and two or more minimum structural units having the same acidic group or different acidic groups are included. What copolymerized 2 or more types of minimum structural units can also be used.

  The copolymer preferably contains 10 mol% or more of a compound having an acidic group selected from (1) to (6) to be copolymerized, and is contained in an amount of 20 mol% or more. Those are more preferred. If it is less than 10 mol%, the development latitude tends to be insufficiently improved.

  Examples of the monomer component to be copolymerized with the polymerizable monomer having a phenolic hydroxyl group, the polymerizable monomer having a sulfonamide group, or the polymerizable monomer having an active imide group include the monomers listed in (m1) to (m12) below. However, it is not limited to these.

(M1) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate.
(M2) Alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, and glycidyl acrylate.
(M3) Alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, and glycidyl methacrylate.
(M4) Acrylamide, methacrylamide, N-methylol acrylamide, N-ethyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N-nitrophenyl acrylamide, N-ethyl- Acrylamide or methacrylamide such as N-phenylacrylamide.
(M5) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether.
(M6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate.
(M7) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene.
(M8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.
(M9) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene.
(M10) N-vinylpyrrolidone, acrylonitrile, methacrylonitrile and the like.
(M11) Unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide.
(M12) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride and itaconic acid.

  The alkali-soluble resin in the present invention is preferably a polymerizable monomer having a phenolic hydroxyl group or a homopolymer or copolymer of a polymerizable monomer having an active imide group, and particularly m-aminosulfonylphenyl methacrylate, N- ( A homopolymer or copolymer of a polymerizable monomer having a sulfonamide group such as p-aminosulfonylphenyl) methacrylamide or N- (p-aminosulfonylphenyl) acrylamide is preferred. The weight average molecular weight is preferably 2,000 or more and the number average molecular weight is 500 or more. More preferably, the weight average molecular weight is 5,000 to 300,000, the number average molecular weight is 800 to 250,000, and the dispersity (weight average molecular weight / number average molecular weight) is 1.1 to 10. . In the present invention, when the alkali-soluble resin is a resin such as a phenol formaldehyde resin or a cresol aldehyde resin, the weight average molecular weight is 500 to 20,000, and the number average molecular weight is preferably 200 to 10,000. .

  These alkali-soluble resins may be used alone or in combination of two or more, and are 5 to 90% by mass, preferably 10 to 85% by mass, particularly preferably 15%, based on the total solid content of the photosensitive composition. Used in an addition amount of ˜80 mass%. If the amount of the alkali-soluble resin added is too small, the durability of the recording layer deteriorates when used as a recording layer of a lithographic printing plate precursor, and if too large, it is substantially an essential component of the present invention “(A Since the amount of addition of “) modified phenolic resin” decreases, it is difficult to obtain the effects of the present invention.

  Further, in order to adjust the solubility of the recording layer, when other onium salts, aromatic sulfone compounds, aromatic sulfonic acid ester compounds, polyfunctional amine compounds, etc. are added, development of an alkali water-soluble polymer (alkali-soluble resin) is performed. It is preferable to add a so-called dissolution inhibitor that improves the dissolution inhibiting function in the liquid. Among them, the onium salt, the o-quinonediazide compound, the sulfonic acid alkyl ester and the like are thermally decomposable, and the alkali-soluble resin is not decomposed. It is preferable to use a substance that substantially lowers the solubility in terms of improving the solubility of the image area in the developer.

Preferred examples of the onium salt used in the present invention include S.P. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Bal et al, Polymer, 21, 423 (1980), diazonium salts described in JP-A-5-158230, U.S. Pat. Nos. 4,069,055, 4,069,056, and JP-A-3-140140. Ammonium salts described in the specification of C. Necker et al, Macromolecules, 17, 2468 (1984), C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), U.S. Pat. Nos. 4,069,055 and 4,069,056; V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent No. 104,143, US Pat. Nos. 5,041,358, 4,491,628, JP-A-2-150848 and JP-A-2-296514. Iodonium salts, J.M. V. Crivello et al, Polymer J. et al. 17, 73 (1985), J. Am. V. Crivello et al. J. et al. Org. Chem. 43, 3055 (1978); R. Watt et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 22, 1789 (1984), J. Am. V. Crivello et al, Polymer Bull. 14, 279 (1985), J. Am. V. Crivello et al, Macromolecules, 14 (5), 1141 (1981), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. 17, 2877 (1979), European Patents 370,693, 233,567, 297,443, 297,442, U.S. Pat. Nos. 4,933,377, 3,902,114 No. 5,041,358, No. 4,491,628, No. 4,760,013, No. 4,734,444, No. 2,833,827, German Patent No. 2,904 No. 626, No. 3,604,580, No. 3,604,581, sulfonium salts described in J.P. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), a selenonium salt described in C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988).
Among these onium salts, diazonium salts and quaternary ammonium salts are particularly preferable from the viewpoints of dissolution inhibition ability and thermal decomposability. In particular, the diazonium salt is preferably a diazonium salt represented by the general formula (I) described in JP-A-5-158230 or a diazonium salt represented by the general formula (1) described in JP-A-11-143064. The diazonium salt represented by the general formula (1) described in JP-A-11-143064 having a small absorption wavelength in the visible light region is most preferable. Moreover, as a quaternary ammonium salt, the quaternary ammonium salt described as (1)-(10) in [Chemical 5] and [Chemical 6] in Unexamined-Japanese-Patent No. 2002-229186 is preferable.

  The counter ion of the onium salt includes tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5-sulfone Examples include acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, and paratoluenesulfonic acid. Of these, particularly preferred are alkyl aromatic sulfonic acids such as hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid and 2,5-dimethylbenzenesulfonic acid.

  Suitable quinonediazides include o-quinonediazide compounds. The o-quinonediazide compound used in the present invention is a compound having at least one o-quinonediazide group, which increases alkali solubility by thermal decomposition, and compounds having various structures can be used. That is, o-quinonediazide helps the solubility of the sensitive material system by both the effect of losing the ability to suppress the dissolution of the binder due to thermal decomposition and the change of o-quinonediazide itself into an alkali-soluble substance. Examples of the o-quinonediazide compound used in the present invention include J. The compounds described in pages 339 to 352 of “Light-sensitive systems” by John Coley (John Wiley & Sons. Inc.) can be used, and in particular, o-quinonediazide reacted with various aromatic polyhydroxy compounds or aromatic amino compounds. The sulfonic acid esters or sulfonic acid amides are preferred. Further, benzoquinone (1,2) -diazidosulfonic acid chloride or naphthoquinone- (1,2) -diazide-5-sulfonic acid chloride and pyrogallol-acetone resin as described in JP-B-43-28403 Esters of benzoquinone- (1,2) -diazide sulfonic acid chloride or naphthoquinone- (1,2) -diazide- described in US Pat. Nos. 3,046,120 and 3,188,210 Esters of 5-sulfonic acid chloride and phenol-formaldehyde resin are also preferably used.

  Further, an ester of naphthoquinone- (1,2) -diazido-4-sulfonic acid chloride and phenol formaldehyde resin or cresol-formaldehyde resin, naphthoquinone- (1,2) -diazido-4-sulfonic acid chloride and pyrogallol-acetone resin Similarly, the esters are also preferably used. Other useful o-quinonediazide compounds are reported and known in numerous patents. For example, JP-A-47-5303, JP-A-48-63802, JP-A-48-63803, JP-A-48-96575, JP-A-49-38701, JP-A-48-13354, Japanese Patent Publication Nos. 41-11222, 45-9610, 49-17474, U.S. Pat. Nos. 2,797,213, 3,454,400, 3,544,323, 3,573,917, 3,674,495, 3,785,825, British Patents 1,227,602, 1,251,345, 1,267, No. 005, No. 1,329,888, No. 1,330,932, German Patent No. 854,890, and the like.

  The amount of the onium salt and / or o-quinonediazide compound that is a degradable dissolution inhibitor is preferably 1 to 10% by mass, more preferably 1 to 5% by mass, particularly preferably the total solid content of the recording layer. Is in the range of 1-2% by weight. These compounds can be used alone, but may be used as a mixture of several kinds.

  The amount of additives other than the o-quinonediazide compound is preferably 0.1 to 5% by mass, more preferably 0.1 to 2% by mass, and particularly preferably 0.1 to 1.5% by mass. The additive and binder according to the present invention are preferably contained in the same layer.

  Further, a dissolution inhibitor having no decomposability may be used in combination, and preferred dissolution inhibitors include sulfonate esters, phosphate esters, and aromatic carboxylic acids described in detail in JP-A-10-268512. Esters, aromatic disulfones, carboxylic anhydrides, aromatic ketones, aromatic aldehydes, aromatic amines, aromatic ethers, etc., as well as lactone skeletons described in detail in JP-A-11-190903, N, N- Examples thereof include an acid color-forming dye having a diarylamide skeleton and a diarylmethylimino skeleton, which also serves as a colorant, and nonionic surfactants described in detail in JP-A No. 2000-105454.

In addition, as a preferable additive when the photosensitive composition of the present invention is used as the uppermost layer of a lithographic printing plate precursor recording layer, from the viewpoint of improving sensitivity, cyclic acid anhydrides, phenols, organic acids, etc. Can be mentioned. In addition, surfactants, image colorants, and plasticizers described later can also be used as additives in the positive recording layer.
Examples of cyclic acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, 3,6-endooxy-4-tetrahydrophthalic anhydride, tetrachlorophthalic anhydride described in US Pat. No. 4,115,128, Maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be used. As phenols, bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,4,4′-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ′, 4 “-Trihydroxytriphenylmethane, 4,4 ′, 3”, 4 ”-tetrahydroxy-3,5,3 ′, 5′-tetramethyltriphenylmethane, etc. Further, organic acids include Examples thereof include sulfonic acids, sulfinic acids, alkylsulfuric acids, phosphonic acids, phosphate esters, and carboxylic acids described in JP-A-60-88942 and JP-A-2-96755.
The proportion of the cyclic acid anhydride, phenols, and organic acids in the recording layer is preferably 0.05 to 20% by mass, more preferably 0.1 to 15% by mass, particularly preferably 0.1 to 0.1% by mass. 10% by mass.

  In addition to these, epoxy compounds, vinyl ethers, and further, phenol compounds having a hydroxymethyl group, phenol compounds having an alkoxymethyl group described in JP-A-8-276558, and the inventors previously proposed. A crosslinkable compound having an alkali dissolution inhibiting action described in JP-A-11-160860 can be appropriately added depending on the purpose.

Further, a printing-out agent for obtaining a visible image immediately after heating by exposure, or a dye or pigment as an image colorant can be added.
Typical examples of the printing-out agent include a combination of a compound that releases an acid by heating by exposure (photoacid releasing agent) and an organic dye that can form a salt. Specifically, combinations of o-naphthoquinonediazide-4-sulfonic acid halides and salt-forming organic dyes described in JP-A-50-36209 and JP-A-53-8128, 36223, 54-74728, 60-3626, 61-143748, 61-151644 and 63-58440, and trihalomethyl compounds and salt-forming organic dyes Can be mentioned. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent temporal stability and give clear printout images.

  As the image colorant, other dyes can be used in addition to the above-mentioned salt-forming organic dyes. Examples of suitable dyes including salt-forming organic dyes include oil-soluble dyes and basic dyes. 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 (oriental chemical industry) Manufactured by Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), and the like. The dyes described in JP-A-62-293247 are particularly preferred. These dyes can be added to the recording layer in a proportion of 0.01 to 10% by mass, preferably 0.1 to 3% by mass, based on the total solid content of the recording layer.

  Furthermore, a plasticizer is added to the uppermost layer of the recording layer of the lithographic printing plate precursor according to the present invention, if necessary, for imparting flexibility of the coating film. For example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid These oligomers and polymers are used.

[Manufacture of lithographic printing plate precursors]
(Coating solvent and coating method)
The recording layer of the lithographic printing plate precursor can be formed by dissolving the photosensitive composition of the present invention in a solvent and coating it on a suitable support. Further, a protective layer, a resin intermediate layer, a back coat layer, etc., which will be described later, provided on the planographic printing plate precursor according to the purpose can be formed in the same manner.
As the coating solvent used here, 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, Examples include dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, and toluene. It is not limited to. 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 mass.
Further, the recording layer coating amount (solid content) on the support obtained after coating and drying varies depending on the use, but in general, an amount such that the coating amount after drying is 0.5 to 5.0 mg / m ² is preferable. The amount of 0.6 to 2.0 mg / m ² is more preferable.

  Various methods can be used for applying the recording layer coating liquid. For example, bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, roll coating, etc. Can be mentioned. As the coating amount decreases, the apparent sensitivity increases, but the film properties decrease.

(Support)
The support used in the lithographic printing plate precursor according to the present invention is a dimensionally stable plate-like material, and is not particularly limited as long as it satisfies the required properties such as strength and flexibility. For example, 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.), paper laminated with metal as described above, vapor-deposited paper, plastic film, and the like.
As the support applicable to the present invention, 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 foreign 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 mass. 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 thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, and particularly preferably 0.2 mm 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 Japanese Patent Laid-Open No. 54-63902, a method in which both are combined can also be used. The roughened aluminum plate is subjected to alkali etching treatment and neutralization treatment as necessary, and then subjected to anodization treatment if desired in order to enhance the water retention and wear resistance of the surface. As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. 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 mass solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / dm ^2. A voltage of 1 to 100 V and an electrolysis time of 10 seconds to 5 minutes are suitable. When the amount of the anodized film is less than 1.0 g / m ² , the printing durability is insufficient, or the non-image part of the planographic printing plate is easily damaged, and ink adheres to the damaged part during printing. So-called “scratch dirt” is likely to occur. After the anodizing treatment, the aluminum surface is subjected to a hydrophilic treatment if necessary. The hydrophilization treatment used in the present invention is disclosed in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734 and 3,902,734. There are alkali metal silicate (such as aqueous sodium silicate) methods. In this method, the support is immersed in an aqueous sodium silicate solution or electrolytically treated. In addition, it is disclosed in potassium fluoride zirconate disclosed in Japanese Patent Publication No. 36-22063 and U.S. Pat. Nos. 3,276,868, 4,153,461, and 4,689,272. A method of treating with polyvinyl phosphonic acid is used.

(Undercoat layer)
The lithographic printing plate precursor according to the present invention has a recording layer made of the photosensitive composition of the present invention on a support, and an undercoat layer is provided between the support and the lower layer as necessary. be able to. By providing this undercoat layer, the undercoat layer between the support and the recording layer functions as a heat insulating layer, and the heat generated by the infrared laser exposure does not diffuse to the support and can be used efficiently. Therefore, there is an advantage that high sensitivity can be achieved. In addition, since the recording layer according to the present invention is located on the exposed surface or in the vicinity thereof even when the undercoat layer is provided, the sensitivity to the infrared laser is maintained well.
In the unexposed area, the recording layer itself that is impermeable to the alkaline developer functions as a protective layer for the undercoat layer, so that the development stability is good and the image is excellent in discrimination. In the exposed area, the components of the recording layer whose dissolution inhibiting ability has been released are quickly dissolved and dispersed in the developer. Since the undercoat layer itself, which is adjacent to the support, is made of an alkali-soluble polymer, it has good solubility in a developer, for example, even when a developer with reduced activity is used. It is considered that this undercoat layer is useful because it dissolves rapidly without the formation of a film and the like and contributes to the improvement of developability.

  Various organic compounds are used as the primer layer component. For example, phosphonic acids having an amino group such as carboxymethylcellulose, dextrin, gum arabic, 2-aminoethylphosphonic acid, and phenylphosphonic acid which may have a substituent Organic phosphonic acids such as naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, optionally substituted phenylphosphoric acid, naphthylphosphonic acid, alkylphosphoric acid and glycerophosphoric acid Organic phosphoric acid, optionally substituted phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid, glycerophosphinic acid and other organic phosphinic acids, glycine and β-alanine amino acids, and triethanolamine hydrochloric acid Has a hydroxy group such as salt -Alanine, and hydrochlorides of amines that may be used in combination of two or more.

  Furthermore, an undercoat layer containing at least one compound selected from the group of organic polymer compounds having a structural unit represented by the following formula is also preferred.

R ¹¹ represents a hydrogen atom, a halogen atom or an alkyl group, and R ¹² and R ¹³ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, —OR ^14. , -COOR ¹⁵ , -CONHR ¹⁶ , -COR ¹⁷ or -CN, or R ¹² and R ¹³ may be bonded to form a ring, and R ^{14 to} R ¹⁷ are each independently an alkyl group or Represents an aryl group, X represents a hydrogen atom, a metal atom, or NR ¹⁸ R ¹⁹ R ²⁰ R ²¹ , and R ^{18 to} R ²¹ each independently represent a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl. Represents a group, or R ¹⁸ and R ¹⁹ may combine to form a ring, and m represents an integer of 1 to 3.

Moreover, as a suitable undercoat layer component in the present invention, there can be mentioned a polymer compound having a component having an acid group and a component having an onium group, as described in JP-A No. 2000-241962. Specific examples include a copolymer of a monomer having an acid group and a monomer having an onium group. An acid group having an acid dissociation index (pKa) of 7 or more is preferred as the acid group, and more preferably —COOH, —SO ₃ H, —OSO ₃ H, —PO ₃ H ₂ , —OPO ₃ H ₂ , — CONHSO ₂ — or —SO ₂ NHSO ₂ —, particularly preferably —COOH. Specific examples of the monomer having an acid group include acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, itaconic acid, maleic acid, maleic anhydride, and styrene having the acid group. Preferred as the onium salt is an onium group composed of Group V or Group VI atoms, more preferably an onium salt composed of nitrogen, phosphorus or sulfur atoms, and particularly preferably an onium salt composed of nitrogen atoms. Salt. Specific examples of the monomer having an onium salt include styrene having a substituent containing an onium group such as a methacrylate having an ammonium group in the side chain, a methacrylamide, a substituent containing an onium group such as a quaternary ammonium group, and the like. It is done.
Furthermore, compounds described in JP-A No. 2000-108538, Japanese Patent Application No. 2002-257484, Japanese Patent Application No. 2003-78699, and the like can be used as necessary.

These undercoat layers can be provided by the following method. That is, a method in which water or an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof is dissolved and applied on an aluminum plate and dried, and water, methanol, ethanol, methyl ethyl ketone, etc. In this method, an aluminum plate is immersed in a solution in which the above organic compound is dissolved in the above organic solvent or a mixed solvent thereof to adsorb the above compound, and then washed and dried with water or the like to provide an undercoat layer. In the former method, a solution having a concentration of 0.005 to 10% by mass of the organic compound can be applied by various methods. In the latter method, the concentration of the solution is 0.01 to 20% by mass, preferably 0.05 to 5% by mass, the immersion temperature is 20 to 90 ° C., preferably 25 to 50 ° C., and the immersion time is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute. The solution used for this can be adjusted to a pH range of 1 to 12 with a basic substance such as ammonia, triethylamine or potassium hydroxide, or an acidic substance such as hydrochloric acid or phosphoric acid. A yellow dye can also be added to improve the tone reproducibility of the image recording material. The coating amount of the undercoat layer is suitably ² to 200 mg / m ² , preferably 5 to 100 mg / m ² . If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. Moreover, even if it is larger than 200 mg / m ^2, it is the same.

  The planographic printing plate precursor according to the present invention is image-formed by heat. Specifically, direct image-like recording using a thermal recording head, scanning exposure using an infrared laser, high-illuminance flash exposure such as a xenon discharge lamp, infrared lamp exposure, and the like are used, but a semiconductor that emits infrared light having a wavelength of 700 to 1200 nm. Exposure by a solid high-power infrared laser such as a laser or a YAG laser is suitable.

The laser output is preferably 100 mW or more, and a multi-beam laser device is preferably used in order to shorten the exposure time. The exposure time per pixel is preferably within 20 μsec, and the energy applied to the recording material is preferably 10 to 500 mJ / cm ² .

  The developer that can be applied to the lithographic printing plate precursor according to the invention is a developer having a pH in the range of 9.0 to 14.0, preferably in the range of 12.0 to 13.5. A known alkaline aqueous solution can be used as the developer (hereinafter referred to as a developer including a replenisher). For example, sodium silicate, potassium, trisodium phosphate, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, Examples thereof include inorganic alkali salts such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium and lithium. In addition, 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 listed. These alkaline aqueous solutions may be used individually by 1 type, and may use 2 or more types together.

  Among the above alkaline aqueous solutions, one of the developing solutions that exert the effect according to the present invention is a so-called one containing an alkali silicate as a base or containing an alkali silicate by mixing a silicon compound with a base. Another more preferable developer, which is an aqueous solution called “silicate developer” having a pH of 12 or more, does not contain an alkali silicate, and contains a non-reducing sugar (an organic compound having a buffering action) and a base. Silicate developer ".

In the former, the aqueous solution of alkali metal silicate is a ratio of silicon oxide SiO ₂ which is a component of silicate and alkali metal oxide M ₂ O (generally expressed as a molar ratio of [SiO ₂ ] / [M ₂ O]. ) And the density, the developability can be adjusted. For example, as disclosed in JP-A-54-62004, the SiO ₂ / Na ₂ O molar ratio is 1.0 to 1.5 (that is, [SiO ₂ ] / [Na ₂ O] is 1.0 to 1.5), and an aqueous solution of sodium silicate having a SiO ₂ content of 1 to 4 mass% is disclosed in JP-B-57-7427. As described, [SiO ₂ ] / [M] is 0.5 to 0.75 (ie, [SiO ₂ ] / [M ₂ O] is 1.0 to 1.5), and SiO ₂ The developer is based on gram atoms of all alkali metals present in the developer. A manner containing potassium at least 20%, aqueous solution of an alkali metal silicate is preferably used.

  Further, a so-called “non-silicate developer” which does not contain an alkali silicate and contains a non-reducing sugar and a base is more preferable for application to the development of the lithographic printing plate material of the present invention. When the lithographic printing plate material is developed using this developer, the surface of the photosensitive layer is not deteriorated and the inking property of the photosensitive layer can be maintained in a good state. In addition, the lithographic printing plate material generally has a narrow development latitude and a large change in the image line width due to the developer pH, but the non-silicate developer contains a non-reducing sugar having a buffering property that suppresses fluctuations in pH. Therefore, it is more advantageous than the case where a developing processing solution containing silicate is used. Furthermore, since non-reducing sugars are less likely to contaminate conductivity sensors, pH sensors and the like for controlling liquid activity compared to silicates, non-silicate developers are advantageous in this respect as well. Further, the effect of improving discrimination is remarkable. This is presumably because the contact (penetration) with the developer which is important in the present invention is mild, and the difference between the exposed and unexposed areas is likely to occur.

  The non-reducing sugar is a saccharide that does not have a free aldehyde group or a ketone group and does not exhibit reducibility, and is a trehalose-type oligosaccharide in which reducing groups are bonded to each other. And sugar alcohols reduced by hydrogenation of saccharides and sugars, both of which can be suitably used in the present invention. In the present invention, non-reducing sugars described in JP-A-8-305039 can be preferably used.

  Examples of the trehalose type oligosaccharides include saccharose and trehalose. Examples of the glycoside include alkyl glycosides, phenol glycosides, and mustard oil glycosides. Examples of the sugar alcohol include D, L-arabit, rebit, xylit, D, L-sorbit, D, L-mannit, D, L-exit, D, L-talit, zulsiit, allozulcit and the like. . Further, maltitol hydrogenated to disaccharide maltose, reduced form obtained by hydrogenation of oligosaccharide (reduced water candy), and the like are preferable. Among these non-reducing sugars, trehalose-type oligosaccharides and sugar alcohols are preferable, and among them, D-sorbitol, saccharose, reduced syrup, etc. are preferable in that they have a buffering action in an appropriate pH region and are inexpensive.

  These non-reducing sugars may be used alone or in combination of two or more. The content of the non-reducing sugar in the non-silicate developer is preferably 0.1 to 30% by mass, and more preferably 1 to 20% by mass. If the content is less than 0.1% by mass, a sufficient buffering effect tends to be not obtained, and if it exceeds 30% by mass, it is difficult to achieve high concentration and the cost tends to increase.

  Examples of the base used in combination with the non-reducing sugar include known alkali agents such as inorganic alkali agents and organic alkali agents. Examples of the inorganic alkaline agent include sodium hydroxide, potassium hydroxide, lithium hydroxide, trisodium phosphate, tripotassium phosphate, triammonium phosphate, disodium phosphate, dipotassium phosphate, diammonium phosphate, Examples thereof include sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate, sodium borate, potassium borate, and ammonium borate.

  Examples of the organic alkali agent include monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanol. Examples include amine, diisopropanolamine, ethyleneimine, ethylenediamine, and pyridine.

  The said base may be used individually by 1 type, and may use 2 or more types together. Among these bases, sodium hydroxide and potassium hydroxide are preferable. In the present invention, as the non-silicate developer, a non-reducing sugar alkali metal salt as a main component can be used instead of the non-reducing sugar and the base.

  In addition, an alkaline buffer composed of a weak acid other than the non-reducing sugar and a strong base can be used in combination with the non-silicate developer. The weak acid preferably has a dissociation constant (pKa) of 10.0 to 13.2, and can be selected from, for example, those described in Ionization Constants of Organic Acids Solution issued by Pergmon Press.

  Specifically, alcohols such as 2,2,3,3-tetrafluoropropanol-1, trifluoroethanol and trichloroethanol, pyridine-2-aldehyde (, aldehydes such as pyridine-4-aldehyde (and the like) , Salicylic acid, 3-hydroxy-2-naphthoic acid, catechol, gallic acid, sulfosalicylic acid, 3,4-dihydroxysulfonic acid, 3,4-dihydroxybenzoic acid, hydroquinone (11.56), pyrogallol, o-, m Compounds having a phenolic hydroxyl group such as-, p-cresol, resorsonol, oximes such as acetoxime, 2-hydroxybenzaldehyde oxime, dimethylglyoxime, ethanediamide dioxime, acetophenone oxime, adenosine, inosine, guanine, cytosine, hypoxanthine , Ki Nucleic acid-related substances such as Nchin, other, diethylaminomethyl acid, benzimidazole, and the like barbituric acid is preferably exemplified.

  To the developer and replenisher, various surfactants and organic solvents are added as necessary for the purpose of promoting and suppressing developability, dispersing development residue, or improving ink affinity of the printing plate image area. it can. As the surfactant, anionic, cationic, nonionic and amphoteric surfactants are preferable. Further, the developer and replenisher may contain a reducing agent such as sodium salt and potassium salt of inorganic acids such as hydroquinone, resorcin, sulfurous acid, and bisulfite, as well as organic carboxylic acid, antifoaming agent, hard water, if necessary. Softeners and the like can be added.

  The lithographic printing plate developed using the developer and the replenisher is post-treated with a desensitizing solution containing washing water, a rinsing solution containing a surfactant or the like, gum arabic or a starch derivative. As post-processing, these processes can be used in various combinations.

Further, when developing using an automatic developing machine, an aqueous solution (replenisher) having a higher alkali strength than that of the developer is added to the developer, so that a large amount of developer can be obtained without replacing the developer in the developer tank for a long time. It is known that PS plates can be processed. This replenishment method is also preferably applied in the present invention. Various surfactants and organic solvents can be added to the developer and replenisher as necessary for the purpose of promoting and suppressing developability, dispersing development residue, and improving ink affinity of the printing plate image area.
Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. If necessary, the developer and replenisher may contain reducing agents such as hydroquinone, resorcin, sulfurous acid, bisulfite, and other inorganic acids such as sodium and potassium salts, organic carboxylic acids, antifoaming agents, and hard water softeners. It can also be added.
The printing plate developed using the developer and the replenisher is post-treated with water-washing water, a rinsing solution containing a surfactant and the like, a desensitizing solution containing gum arabic and starch derivatives. As the post-treatment of the printing plate precursor according to the present invention, these treatments can be used in various combinations.

  In recent years, automatic developing machines for printing plates 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 transporting the printing plate, each processing liquid tank and a spray device, and each pumped up by a pump while transporting the exposed printing plate horizontally. The processing liquid is sprayed from the spray nozzle and developed. In addition, recently, a method is also known in which a printing plate is dipped and conveyed by a submerged guide roll or the like in a processing liquid tank filled with the processing liquid. 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, a so-called disposable processing method in which processing is performed with a substantially unused processing solution can also be applied.

  In the lithographic printing plate precursor according to the present invention, image portions unnecessary for the lithographic printing plate obtained by image exposure, development, washing and / or rinsing and / or gumming (for example, film edge traces of the original film). Etc.), the unnecessary image portion is erased. Such erasing is preferably performed by applying an erasing solution as described in, for example, Japanese Patent Publication No. 2-13293 to an unnecessary image portion, leaving it for a predetermined time, and then washing with water. A method of developing after irradiating an unnecessary image portion with an actinic ray guided by an optical fiber as described in JP-A-59-174842 can also be used.

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 make a lithographic printing plate with a higher printing durability, if desired, Burning process is performed.
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 method in which the printing plate is immersed and applied in a vat filled with the surface-adjusting liquid, 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 mass). The planographic printing plate coated with the surface-adjusting solution 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.). The The heating temperature and time in this case are preferably in the range of 180 to 300 ° C. and in the range of 1 to 20 minutes, although depending on the type of components forming the image.

The lithographic printing plate that has been burned 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. If so, so-called desensitizing treatment such as gumming can be omitted.
A lithographic printing plate precursor using the photosensitive composition of the present invention as a recording layer is converted into a lithographic printing plate by such treatment. This planographic printing plate is applied to an offset printing machine or the like and used for printing a large number of sheets. The lithographic printing plate precursor using the photosensitive composition of the present invention for the recording layer has the advantages of excellent chemical resistance in the image area, wide development latitude, and excellent image reproducibility.

EXAMPLES Hereinafter, although this invention is demonstrated according to an Example, the scope of the present invention is not limited to these Examples.
[Examples 1-3]
(Production of support)
The support body was produced by processing through the process shown below using a JIS-A-1050 aluminum plate with a thickness of 0.3 mm.

(A) Mechanical surface roughening treatment While supplying a suspension of abrasive (silica sand) having a specific gravity of 1.12. Roughening was performed. The average particle size of the abrasive was 8 μm, and the maximum particle size was 50 μm. The material of the nylon brush was 6 · 10 nylon, the hair length was 50 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 7 kW plus with respect to the load before the brush roller was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The rotation speed of the brush was 200 rpm.

(B) Alkali etching treatment The aluminum plate obtained above was sprayed with an aqueous NaOH solution at a temperature of 70 ° C. (concentration 26 mass%, aluminum ion concentration 6.5 mass%) to perform an etching treatment, and the aluminum plate was 6 g / m. ² dissolved. Thereafter, washing with water was performed using well water.

(C) Desmut treatment A desmut treatment was performed by spraying with a 1% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 0.5% by weight of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut was the waste liquid from the step of electrochemical surface roughening using alternating current in nitric acid aqueous solution.

(D) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a nitric acid 10.5 g / liter aqueous solution (aluminum ion 5 g / liter) at a temperature of 50 ° C. The AC power supply waveform is electrochemically roughened using a carbon electrode as the counter electrode, using a trapezoidal rectangular wave alternating current with a time TP of 0.8 msec until the current value reaches a peak from zero, a DUTY ratio of 1: 1. went. Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type.
The current density was 30 A / dm ² at the peak current value, and the amount of electricity was 220 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode.
Thereafter, washing with water was performed using well water.

(E) Alkaline etching treatment An aluminum plate is etched by spraying at a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass at 32 ° C., 0.20 g / m ^{2 of the} aluminum plate is dissolved, The smut component mainly composed of aluminum hydroxide generated when electrochemical surface roughening was used was removed, and the edge portion of the generated pit was melted to smooth the edge portion. Thereafter, washing with water was performed using well water.
(F) Desmut treatment Desmut treatment was performed by spraying with a 15% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 4.5% by weight of aluminum ions), and then washed with water using well water. The nitric acid aqueous solution used for the desmut was the waste liquid from the step of electrochemical surface roughening using alternating current in nitric acid aqueous solution.

(G) Electrochemical surface roughening treatment An electrochemical surface roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 7.5 g / liter aqueous solution (containing 5 g / liter of aluminum ions) at a temperature of 35 ° C. The AC power supply waveform was a rectangular wave, and an electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type.
The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 50 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode.
Thereafter, washing with water was performed using well water.

(H) Alkali etching treatment The aluminum plate was sprayed at a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass at 32 ° C. to dissolve the aluminum plate at 0.10 g / m ² , The smut component mainly composed of aluminum hydroxide generated during the electrochemical surface roughening treatment was removed, and the edge portion of the generated pit was dissolved to smooth the edge portion. Thereafter, washing with water was performed using well water.

(I) Desmut treatment A desmut treatment by spraying was performed with a 25% by mass aqueous solution of sulfuric acid having a temperature of 60 ° C. (containing 0.5% by mass of aluminum ions), and then water washing by spraying was performed using well water.
(J) Anodizing treatment As the electrolytic solution, sulfuric acid was used. The electrolyte solutions all had a sulfuric acid concentration of 170 g / liter (containing 0.5 mass% of aluminum ions), and the temperature was 43 ° C. Thereafter, washing with water was performed using well water.
Both current densities were about 30 A / dm ² . The final oxide film amount was 2.7 g / m ² .

<Support A>
The steps (a) to (j) were sequentially performed, and the support A was produced so that the etching amount in the step (e) was 3.4 g / m ² .
<Support B>
A support B was prepared by sequentially performing the steps except that the steps (g), (h), and (i) were omitted.

<Support C>
A support C was prepared by sequentially performing the steps except that the steps (a), (g), (h), and (i) were omitted.
<Support D>
Except for omitting the process of the above step (a) and (d) (e) (f ) performs the steps in turn, supported as total amount of electricity is 450C / dm ² in step (g) Body D was prepared.
The following supports A, B, C and D were then subjected to the following hydrophilic treatment and undercoating treatment.

(K) Alkali metal silicate treatment An aluminum support obtained by anodizing treatment was immersed in a treatment layer of a 1 mass% aqueous solution of sodium silicate No. 3 at a temperature of 30 ° C. for 10 seconds to immerse the alkali metal silica. Acid salt treatment (silicate treatment) was performed. Then, the water washing by the spray using well water was performed. The amount of silicate adhering at that time was 3.6 mg / m ² .

<Support E>
An aluminum plate having a thickness of 0.24 mm was degreased with an aqueous solution of sodium hydroxide, and this was electropolished in a 20% hydrochloric acid bath to obtain a grained plate having a center line average roughness (Ra) of 0.5 μm. . Then, this grained plate was anodized in a 20% sulfuric acid bath at a current density of 2 A / dm ² to form an oxide film of 2.7 g / m ² , washed with water and dried to provide an aluminum support. Body E was obtained.

[Undercoating]
On the aluminum support after the alkali metal silicate treatment obtained as described above, an undercoat solution having the following composition was applied and dried at 80 ° C. for 15 seconds. The coating amount after drying was 15 mg / m ² .
(Undercoat liquid)
・ The following polymer compound (I or II) 0.3 g
・ Methanol 100g
・ Water 1g

(Formation of recording layer)
Next, the lower layer coating solution A having the following composition was applied to the support with the undercoat layer obtained above with a wire bar, and then dried in a drying oven at 140 ° C. for 50 seconds to obtain a coating amount of 0.85 g. / M ² .
The uppermost layer coating liquid B having the following composition was applied to the obtained support with a lower layer with a wire bar. After coating, drying at 140 ° C. for 60 seconds to form a recording layer having a multilayer structure with a total coating amount of 1.07 g / m ² , positive lithographic printing of Examples 1 to 3 and Comparative Examples 1 and 2 I got the original version.

<Coating liquid A for lower layer>
・ (A) Modified phenolic tree described in Table 1. 2.13 g
-0.26 g of (B) acid coloring dye described in Table 1
Cyanine dye P [(C) component: the following structure] 0.134 g
・ Bis-p-hydroxyphenylsulfone 0.126 g
・ Tetrahydrophthalic anhydride 0.19g
・ 0.008 g of p-toluenesulfonic acid
2-methoxy-4- (N-phenylamino)
Benzenediazonium hexafluorophosphate 0.032 g
・ Ethyl violet 6-naphthalenesulfonic acid 0.078g
-Fluorosurfactant (Megafac F-780, manufactured by Dainippon Ink & Chemicals, Inc.) 0.023g
・ Γ-Butyrolactone 13.16g
・ Methyl ethyl ketone 25.39g
・ 1-methoxy-2-propanol 12.95 g

<Coating solution B for top layer>
-M-cresol / p-cresol novolak resin (molar ratio 60:40, weight average molecular weight 5,000) 0.341 g
Cyanine dye P [(C) component: the above structure] 0.019 g
・ The following structural polymer Q / MEK 30% solution 0.14 g
・ Quaternary ammonium salt R (the following structure) 0.004g
・ Methyl ethyl ketone 2.63g
・ 1-methoxy-2-propanol 5.27g

[Comparative Examples 1-3]
A lithographic printing plate precursor of Comparative Example 1 was obtained in the same manner as in Example 1, except that (B) the acid color-forming dye was not used in coating solution A. Similarly, in Example 1, instead of the modified phenolic resin (A) in the coating solution A, novolak resin A (phenol / m-cresol / p-cresolno resin (molar ratio: 50/30/20, weight average molecular weight) 5, 300), and (B) an acid color-forming dye was not used, in the same manner, to obtain a lithographic printing plate precursor of Comparative Example 2. Further, Table 1 was added to the coating liquid A used in Comparative Example 2. A lithographic printing plate precursor of Comparative Example 3 was obtained in the same manner except that the acid color-developing dye described in (B) was added.

[Examples 4 to 6]
A recording layer coating solution C having the following composition was applied to a support with an undercoat layer obtained by the same method as in Examples 1 to 3 with a wire bar. After coating, drying was performed at 140 ° C. for 60 seconds to obtain positive lithographic printing plate precursors of Examples 4 to 6 with a total coating amount of 1.80 g / m ² .

<Recording layer coating solution C>
-(B) Acid coloring pigment described in Table 1 0.08 g
-(A) modified phenolic resin described in Table 1 0.75 g
-M-cresol / p-cresol novolak resin (molar ratio 60:40, weight average molecular weight 5,000) 0.25 g
・ 0.003 g of p-toluenesulfonic acid
・ Tetrahydrophthalic anhydride 0.03g
-Cyanine dye P [(C) component: the above structure] 0.017 g
・ Victoria Pure Blue (Dye with BOH counter anion as 1-naphthalenesulfonic acid anion) 0.015g
・ Γ-Butyrolactone 10g
・ Methyl ethyl ketone 10g
1-methoxy-2-propanol 1g

[Comparative Examples 4 to 6]
A lithographic printing plate precursor of Comparative Example 4 was obtained in the same manner as in Example 4 except that (B) the acid coloring dye was not used in the coating solution C. Similarly, in Example 4, the novolak resin A used in Comparative Example 2 was added to the coating liquid C instead of (A) the modified phenolic resin, and (B) the acid coloring dye was not used. Thus, a planographic printing plate precursor of Comparative Example 5 was obtained. A lithographic printing plate precursor of Comparative Example 6 was obtained in the same manner except that (B) acid color-forming dye described in Table 1 was further added to the coating liquid C used in Comparative Example 5.

[Examples 7 to 9]
The coating liquid D having the following composition was applied to a support with an undercoat layer obtained by the same method as in Examples 1 to 3 using a wire bar. After coating, drying was performed at 150 ° C. for 100 seconds to obtain positive lithographic printing plate precursors of Examples 7 to 9 with a total coating amount of 1.40 g / m ² .

<Coating liquid D>
-(B) acid coloring pigment | dye of Table 1 0.25g
-(A) Modified phenolic resin described in Table 1 2.072 g
Cyanine dye P [(C) component: the above structure] 0.052 g
・ Ethyl violet 6-naphthalenesulfonic acid 0.078g
・ Methyl ethyl ketone 25.30g

[Comparative Examples 7-9]
A lithographic printing plate precursor of Comparative Example 7 was obtained in the same manner as in Example 7 except that (B) the acid coloring dye was not used in the coating solution D. Similarly, in Example 7, instead of (A) the modified phenolic resin, the novolak resin A used in Comparative Example 2 was added to the coating solution D, and (B) the acid coloring dye was not used. Thus, a planographic printing plate precursor of Comparative Example 8 was obtained. A lithographic printing plate precursor of Comparative Example 9 was obtained in the same manner except that (B) acid color-forming dye described in Table 1 was further added to the coating liquid D used in Comparative Example 8.

[Evaluation of planographic printing plate precursor]
Next, performance evaluation of the positive type lithographic printing plate precursors of Examples 1 to 9 and Comparative Examples 1 to 9 was performed. The evaluation test was conducted on the sample stored at 25 ° C. for 14 days after the photosensitive layer was applied.

(Evaluation of development latitude)
The positive type lithographic printing plate precursors of Examples 1 to 9 and Comparative Examples 1 to 9 thus obtained were drawn on the image of a test pattern on a Trend setter 800 manufactured by Creo under the conditions of a beam intensity of 10.0 W and a drum rotation speed of 250 rpm. (Exposure) was performed.
Next, for Examples 1 to 3 and 7 to 9 and Comparative Examples 1 to 3 and 7 to 9, electrical conductivity was obtained by diluting the developer DT-2R manufactured by Fuji Photo Film Co., Ltd. with water (1: 9). The PS processor LP-940HII manufactured by Fuji Photo Film Co., Ltd. was charged with a solution in which carbon dioxide gas was blown to 37 mS / cm and a water dilution (1: 1) solution of the finisher FG-1 manufactured by Fuji Photo Film Co., Ltd. The film was developed with a liquid temperature of 30 ° C. and a development time of 12 seconds. Thereafter, an appropriate amount of DT-2R diluted with water (1: 9) was added to the developer, the conductivity was adjusted to 39 mS / cm, and the lithographic printing plate precursor in which the test pattern was drawn in an image shape as before was developed. . Further, the electrical conductivity was increased by 2 mS / cm, and this operation was continued until a film loss due to image development was observed remarkably.
For Examples 4 to 6 and Comparative Examples 4 to 6, Fuji Photo Film Co., Ltd. (Fuji Photo Film Co., Ltd.) was used in which carbon dioxide gas was blown into developer LH-DRS until the conductivity reached 78 mS / cm. Using a PS processor LP940HII manufactured by Fuji Photo Film Co., Ltd., charged with a water diluted (1: 1) solution of Finisher FP-2W manufactured by Co., Ltd., development was performed at a development time of 26 seconds while maintaining the liquid temperature at 28 ° C. Thereafter, an appropriate amount of carbon dioxide gas was blown to adjust the conductivity to 76 mS / cm, and the lithographic printing plate precursor on which the test pattern was drawn in an image shape was developed as before. Further, the electrical conductivity was decreased by 2 mS / cm, and this operation was continued until the stain due to the poorly developed non-image area remaining film was observed.

In the developed plates of Examples and Comparative Examples after development, the plates developed with each conductivity were checked with a magnifier of 50 times to see whether there was any stain or coloring due to poorly developed non-image area residual film. The conductivity of the developer that could be developed was determined. Next, the conductivity at which the developed film does not decrease in the unexposed area, specifically, the image density of the solid area before development is measured with a GRETAG reflection densitometer D196 (manufactured by GretagMacbeth), and 0 is determined from this image density. The electric conductivity of the developer having a solid portion having an image density of 10 or more was determined.
The development latitude was defined as the conductivity range of the developer that was able to be developed satisfactorily and the limit of conductivity at which the decrease in the developed film was maintained. The results are shown in Table 1.

(Evaluation of chemical resistance)
To the positive type lithographic printing plate precursors of Examples 1 to 9 and Comparative Examples 1 to 9, a cleaner liquid (Fuji Photo Film Co., Ltd .: “Plate Cleaner CL2”) was dropped, The concentration change of the dripping part after 1 minute was compared visually. The case where there was no change in density was indicated as ◯, the case where there was almost no change was indicated as Δ, and the case where there was a significant change in density was indicated as x. The results are shown in Table 1.

(Image reproducibility)
The positive lithographic printing plate precursors of the obtained Examples and Comparative Examples were 175 lpi / 2400 dpi / 2% dot test pattern under the conditions of beam strength 10.0 W and drum rotation speed 250 rpm on a Trendsetter 3244 manufactured by Creo. The image was drawn (exposure).
After exposure under the above conditions, Examples 1-3, 7-9, and Comparative Examples 1-3, 7-9 have a developer DT-2 manufactured by Fuji Photo Film Co., Ltd. (diluted with a conductivity of 43 mS / cm). And Fuji Photo Film Co., Ltd. Finisher-FP-2W (diluted 1: 1) and Fuji Photo Film Co., Ltd. PS Processor-LP-940H, and the liquid temperature was adjusted to 30 ° C. Development was carried out with a keeping development time of 12 seconds.
For Examples 4 to 6 and Comparative Examples 4 to 6, the developer LH-DS (conductivity 70 mS / cm) manufactured by Fuji Photo Film Co., Ltd. and the finisher FP-2W manufactured by Fuji Photo Film Co., Ltd. were diluted with water. Using a PS processor LP940HII manufactured by Fuji Photo Film Co., Ltd. (1: 1) charged with the solution, the solution was maintained at 28 ° C. and developed for 26 seconds.
Thereafter, the printing plates of the example and the comparative example were printed with a Heidel KOR-D machine, and after printing 5000 sheets, the halftone dot portion of the obtained printed matter was observed with a magnifying glass of 50 times. The image area was checked for stains and image reproducibility was evaluated according to the following criteria. The results are shown in Table 1.
◎: Image reproducibility is very good ○: Image reproducibility is good △: Image portion is slightly chipped and non-image portion is stained, but there is no practical problem ×: Image reproducibility is poor and practical Problem level

  The (A) modified phenolic resin described in Table 1 uses the compounds listed above as exemplary compounds. Moreover, the (B) acid color-forming dyes listed in Table 1 are the compounds shown below.

As apparent from Table 1, the lithographic printing plate precursors of Examples 1 to 9 using the photosensitive composition of the present invention for the recording layer have a wide development latitude and excellent chemical resistance. all right. Moreover, the reproducibility of high-definition images was also good.
On the other hand, all the lithographic printing plate precursors of the comparative examples have narrower development latitude than the examples, and in particular, even when (A) a specific phenol resin is used, The lithographic printing plate precursors 4 and 7, (A) the lithographic printing plate precursors of Comparative Examples 2, 5, and 8 that do not use the specific phenol resin, and (B) the acid-color-forming dye (A) the specific phenol resin Instead, all of the lithographic printing plate precursors of Comparative Examples 3, 6, and 9 using a common phenolic resin were significantly inferior in development latitude, chemical resistance, and image reproducibility.
In the comparison of (Examples 1 to 3 and Comparative Examples 1 to 6), (Examples 4 to 6 and Comparative Examples 4 to 6), and (Examples 7 to 9 and Comparative Examples 7 to 9), recording was performed. It has been found that even when the composition of the layer coating solution is changed, the excellent effect of the present invention can be similarly obtained regardless of whether the structure of the recording layer is a single layer or a multilayer.

Claims (1)

(A) a polymer compound having a structural unit represented by the following general formula (1) and a phenolic hydroxyl group in the molecule, (B) an acid-coloring dye represented by the following general formula (2), and (C ) A photosensitive composition containing an infrared absorber.

In the general formula (1), R ¹ represents a hydrogen atom or an arbitrary substituent, X represents a divalent linking group, and R ² represents a hydrogen atom capable of hydrogen bonding with an unshared electron pair binding site. And a monovalent substituent capable of forming two or more thermally reversible hydrogen bonds.

In the general formula (2), ring A, ring B and ring C each independently represent an aromatic hydrocarbon group having 1 to 3 nuclei or an aromatic heterocyclic group, and at least one of ring B and ring C. And at least one substituent selected from the group consisting of an amino group, an alkoxy group, an aryloxy group, an alkylthio group, and an arylthio group. Ring B and ring C may be bonded to each other via a bonding group.
W ¹ represents a carbonyl group, a thiocarbonyl group, or —C (R ²⁵ ) ═N—, wherein R ²⁵ represents a hydrogen atom or a hydrocarbon group, and Q ¹ represents an oxygen atom, a sulfur atom or an imino group. To express. R ^{21 to} R ²⁴ each independently represents a hydrogen atom or a hydrocarbon group. m and n each independently represents 0 or 1.