JP2007010907A - Method for manufacturing planographic printing plate precursor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a planographic printing plate precursor for an infrared laser photosensitive type having superior flaw resistance and chemical resistance of a recording layer, wide development latitude, and superior reproducibility of a fine image. <P>SOLUTION: In the method for manufacturing the planographic printing plate precursor having on a support a recording layer containing an alkali-soluble resin including a monomer unit having a phenyl group substituted by a substituent group expressed by formula (1) and an infrared absorbent, after applying and drying the recording layer on the support, aging treatment is performed for 5 hours or more under an environment that the temperature is ≥60°C and ≤100°C, and the humidity is ≥60% and ≤95%. In formula (1), Z<SP>1</SP>, Z<SP>2</SP>, and Z<SP>3</SP>each independently represent a hydrogen atom or a monovalent substituent group consisting of a non-metal atom. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a lithographic printing plate precursor, and more particularly to a method for producing a so-called direct plate-making infrared laser-sensitive positive lithographic printing plate precursor capable of making a plate directly from a digital signal of a computer or the like. The present invention relates to a method for producing a lithographic printing plate precursor having excellent reproducibility of fine images such as.

  As a lithographic printing plate, a lithographic printing plate capable of being made with an infrared laser has recently attracted attention. That is, with the recent development of lasers, solid lasers and semiconductor lasers having a light emitting region from the near infrared to the infrared can be easily obtained in high output and small size. Such a laser is useful as an exposure light source for making a planographic printing plate directly from digital data of a computer or the like.

The positive type lithographic printing plate material for infrared laser has an alkaline aqueous solution-soluble binder resin and an IR dye that absorbs light and generates heat as an essential component. In the non-exposed part (image part), Acts as a dissolution inhibitor that substantially lowers the solubility of the binder resin through interaction with the binder resin. In the exposed area (non-image area), the interaction between the IR dye and the binder resin is weakened by the generated heat, resulting in an alkali. A lithographic printing plate is formed by dissolving in a developer.
However, such a positive lithographic printing plate material for infrared laser has a narrow latitude at the time of development, and due to slight fluctuations in development conditions, the unexposed part (image part) is dissolved at the time of development. There is a problem that image defects such as white spots appear in the areas or stains occur in the non-image areas due to development defects in the exposed areas (non-image areas).

Such a problem originates in the essential difference in the plate making mechanism between the positive lithographic printing plate material for infrared laser and the positive lithographic printing plate material made by UV exposure.
That is, in a positive type lithographic printing plate material made by UV exposure, an alkaline aqueous solution-soluble binder resin and an onium salt or a quinonediazide compound are essential components. The onium salt or the quinonediazide compound is a non-exposed portion ( The image portion) functions as a dissolution inhibitor by interaction with the binder resin, and the exposed portion (non-image portion) functions as a dissolution accelerator by being decomposed by light and generating an acid.
In contrast, IR dyes and the like in positive lithographic printing plate materials for infrared lasers only act as dissolution inhibitors for non-exposed areas (image areas) and do not promote dissolution of exposed areas (non-image areas). Absent.

Further, since the image forming ability of such a positive lithographic printing plate precursor for infrared laser depends on the heat generated by infrared laser exposure on the surface of the recording layer, the image is formed near the support by the diffusion of heat to the support. The amount of heat used for the formation, that is, the solubilization of the recording layer is reduced, and the effect of eliminating the development inhibiting ability of the recording layer in the non-image area is not sufficiently obtained, and the difference in solubility between the image area and the non-image area is small As a result, there was a problem that the highlight reproducibility was insufficient.
In order to solve the problem of highlight reproducibility, it is conceivable to form the recording layer using a material that can be easily developed in the non-image area. The recording layer formed is not only weak but has a problem that the small area image is damaged by the developing solution, and also has a problem that it is inferior in cleaning resistance, such as being damaged by a plate cleaner used during printing. There has been a demand for a recording layer having excellent properties such as excellent cleaner resistance and durability of the film and excellent developability after the dissolution inhibiting action is released.

  In order to solve the above problems, a technique for forming a recording layer having an alkali-soluble resin having excellent cleaner resistance has been proposed (for example, see Patent Document 1). However, although this recording layer shows improved cleaner resistance, the effect of suppressing dissolution in the unexposed area is not sufficient, and the periphery of a few scratches that have entered before development dissolves during development, and white spots appear in the image area. There is a problem that a fine image such as a halftone dot or a fine line is generated from the side surface during development, and an undesired reduction in image area occurs. In particular, it was found that when an FM screen with a small halftone dot is used, a slight change in developer sensitivity leads to a reduction in halftone dot area, and the problem of a decrease in image reproducibility is significant.

In addition, attempts have been made to improve the solubility resistance against alkali developability in the vicinity of the surface by introducing a polar group such as water from the surface into the recording layer (see, for example, Patent Document 2). However, although the sensitivity is improved by the technique of Patent Document 2, it is not a satisfactory level. In particular, the resistance to the cleaner is insufficient, and the development resistance is still insufficient in the deep part near the support. There was a problem that the point reproducibility was insufficient.
JP 2005-62875 A WO99 / 21715

  An object of the present invention made in response to the above-mentioned various problems is an infrared laser photosensitive lithographic plate having good scratch resistance and chemical resistance of the recording layer, wide development latitude, and excellent reproducibility of fine images. It is to provide a method for producing a printing plate precursor.

As a result of extensive research, the present inventor has formed a recording layer containing an alkali-soluble resin containing a monomer unit having a phenyl group substituted with a substituent having a specific structure, and an infrared absorber, and then a predetermined aging As a result, it has been found that a lithographic printing plate precursor that suppresses scratching of the recording layer and is excellent in reproducibility of fine images can be obtained, thereby solving the present invention.
That is, the method for producing a lithographic printing plate precursor according to the present invention includes an alkali-soluble resin containing a monomer unit having a phenyl group substituted by a substituent represented by the following general formula (1) on a support, and infrared absorption. A lithographic printing plate precursor comprising a recording layer containing an agent, wherein the recording layer is coated on the support and dried, and then the temperature is 60 ° C. or higher and 100 ° C. or lower and the humidity is 60% or higher and 95%. Aging treatment is performed for 5 hours or more in an environment of less than 5%.

一般式（１）

General formula (1)

Z ¹ , Z ² and Z ³ each independently represent a monovalent substituent consisting of a hydrogen atom or a non-metal atom.

Although the operation of the present invention is not clear, it is presumed as follows.
In the method for producing an infrared laser photosensitive lithographic printing plate of the present invention, an alkali-soluble resin containing a monomer unit having a phenyl group substituted with a substituent represented by the general formula (1) on the support and an infrared ray After applying the recording layer containing the absorbent, by performing aging by heating and humidification, in the recording layer, the cohesive force is improved by the function of heat, and the side chain of the alkali-soluble resin contained in the recording layer is improved. In the relationship with the structural unit —CH—N <bonding portion, the water-mediated interactivity is improved due to the humidification function, and the dissolution inhibiting function of the alkali-soluble resin is enhanced, and the film properties of the recording layer are increased. Will become stronger, improving the scratch resistance and chemical resistance of the surface. Such an interaction is quickly released in the exposed portion and exhibits good solubility in the developer. For this reason, the difference in solubility between the exposed and unexposed areas is increased, the development latitude is improved, and as a result, the fluctuation of the fine image formed by the FM screen or the like is suppressed, and high image reproducibility is achieved. It is thought to have been realized.

  According to the method for producing a lithographic printing plate precursor according to the invention, an alkali-soluble resin and an infrared absorber containing a monomer unit having a phenyl group substituted with a substituent represented by the general formula (1) on a support. By applying aging by heating and humidification after applying the recording layer containing, the recording layer is strengthened by strengthening the function of inhibiting dissolution of the alkali-soluble resin. A lithographic printing plate precursor having good chemical properties, wide development latitude, and excellent reproducibility of fine images such as highlight images can be produced.

Hereinafter, the present invention will be described in detail.
The infrared laser-sensitive lithographic printing plate precursor to which the method of the present invention is applied has a recording layer containing a special alkali-soluble resin and an infrared absorber on a support. First, each component contained in the lithographic printing plate precursor to which the production method of the present invention is applied will be described in detail sequentially.

[Alkali-soluble resin]
The alkali-soluble resin used in the present invention includes a monomer unit having a phenyl group substituted with a substituent represented by the following general formula (1).

一般式（１）

General formula (1)

In the general formula (1), Z ¹ , Z ² , and Z ³ each independently represent a monovalent substituent composed of a hydrogen atom or a nonmetallic atom.
The monovalent substituent composed of a nonmetallic atom represented by Z ¹ , Z ² , or Z ³ is preferably a substituent composed of a linking site and a terminal site. In addition, a connection site | part is used as needed, and the monovalent | monohydric substituent which consists of a nonmetallic atom may be formed only from the terminal site | part.
Moreover, the monovalent substituent consisting of a nonmetallic atom may be further substituted with an alkyl group or an aryl group.

The linking moiety, alkylene group, an alkenylene group, phenylene, arylene groups such as naphthalene, pyridyl, pyrazinyl, pyrimidyl, heterocyclic group containing a heteroatom such as _{thiazolyl, - (C 2 H 4 O} ) n - group (n = _{1~12), - (C 2 H} 4 S) n - group (n = 1~12), - Ph -NHSO 2 - group, or include a combination of these.

As the terminal portion, a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkyl group, an unsaturated cyclic hydrocarbon group, an aryl group, a heterocyclic group, an aralkyl group, -OR ^1, -SR ^1, - ^{COOR 1, -O-COR 1,} -CO-R 2, -SO 3 -R 1, -SO 2 -R 1, -CN, -NO 2, a halogen atom, a phosphate group, phosphonate group, t-amine group, Examples include an amide group, an imide group, and a sulfonamide group. Here, R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkyl group, an unsaturated cyclic hydrocarbon group, an aryl group, a heterocyclic group, or an aralkyl group. , Selected from amine groups.

  The alkali-soluble resin containing a monomer unit having a phenyl group substituted by the substituent represented by the general formula (1) is specifically represented by the following general formula (2).

一般式（２）

General formula (2)

Preferred functional groups selected as R, Z ¹ , Z ² , and Z ³ included in the alkali-soluble resin having the structure represented by the general formula (2) are shown in Tables 1 to 3 below. .

  Specific examples of the alkali-soluble resin suitably used for the lithographic printing plate precursor according to the invention are listed in Table 4 below, but the invention is not limited thereto.

  The molecular weight of the alkali-soluble resin is preferably 2000 or more in terms of weight average molecular weight, and more preferably in the range of 3000 to 500,000. Moreover, in number average molecular weight, 1000 or more are preferable and the inside of the range of 2000-400,000 is more preferable.

  The content of the (A) specific alkali-soluble resin in the composition constituting the recording layer of the lithographic printing plate precursor used in the present invention is preferably 30 to 98% by mass, more preferably 25 to 90% in terms of solid content. It is the range of mass%.

[Infrared absorber]
The recording layer of the lithographic printing plate precursor used in the present invention contains an infrared absorber. The infrared absorber that can be used here is not particularly limited as long as it is a substance that absorbs light energy radiation and generates heat, but is compatible with easily available high-power lasers. From the viewpoint of the above, preferred are various dyes or pigments known as infrared absorbing dyes or pigments having an absorption maximum at a wavelength of 700 nm to 1200 nm.

  As such an infrared absorber, known various pigments and dyes are preferably exemplified. Examples of the pigment include a commercially available pigment and color index (CI) manual, “Latest Pigment Handbook” (edited by the Japan Pigment Technical Association, published in 1977), “Latest Pigment Applied Technology” (published by CMC, published in 1986), “ Examples thereof include pigments described in "Printing Ink Technology", published by CMC Publishing, 1984).

  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, isoindolinone pigments Quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, and carbon black.

  The pigment may be used without being subjected to a surface treatment or may be used after being subjected to a surface treatment. The surface treatment method includes a method of surface coating with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (for example, silane coupling agent, epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The surface treatment method is described in “Characteristics and Application of Metal Soap” (Sachibo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). .

  The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm. When the particle size of the pigment is less than 0.01 μm, it may not be preferable in terms of the stability of the dispersion in the recording layer coating solution, whereas when it exceeds 10 μm, the recording layer is uniform. It is not preferable in terms of sex.

  As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. Dispersers such as an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three roll mill, and a pressure kneader are used for the dispersion. . Details of the dispersion method are described in "Latest Pigment Application Technology" (CMC Publishing, 1986).

  Examples of the dye include commercially available dyes and known dyes described in literature (for example, “Dye Handbook” edited by the Society of Synthetic Organic Chemistry, published in 1970), such as azo dyes, metal complex azo dyes, pyrazolone azos. And dyes such as dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, and cyanine dyes. Among the pigments and dyes, pigments and dyes that absorb infrared light or near infrared light are particularly preferable because they are suitable for use in lasers that emit infrared light or near infrared light.

  Carbon black is preferably used as the pigment that absorbs the infrared light or near infrared light. Examples of the dye that absorbs the infrared light or near infrared light include, for example, JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, and JP-A-60-78787. Methine dyes described in JP-A-58-173696, JP-A-58-181690, JP-A-58-194595, etc., JP-A-58-112793, Naphthoquinone dyes described in JP-A-58-224793, JP-A-59-48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc. Examples thereof include squarylium dyes described in Japanese Utility Model Laid-Open No. 58-112792, and cyanine dyes described in British Patent 434,875.

  Further, as the dye, a near-infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used, and substituted arylbenzo (described in US Pat. No. 3,881,924) Thio) pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, JP-A-58-2220143, JP-A 59-41363, JP-A-59-84248, JP-A-59-84249, JP-A-59-146063, and JP-A-59-146061, pyrylium compounds, JP-A-59 -216146, the pentamethine thiopyrylium salt described in U.S. Pat. No. 4,283,475, JP-B-5-13514, JP-A-5-19702 Pyrylium compounds disclosed in distribution, Epolight III-178, EpolightIII-130, Epolight III-125, EpolightV-176A or the like is used particularly preferably.

  Moreover, as said dye, as another especially preferable example, the near-infrared absorptive dye described as U.S. Pat. No. 4,756,993 as the formulas (I) and (II) can be mentioned.

  Particularly preferred among these dyes are cyanine dyes, squarylium dyes, pyrylium salts, nickel thiolate complexes, and indolenine cyanine dyes. Further, cyanine dyes and indolenine cyanine dyes are preferable, and one particularly preferable example is a cyanine dye represented by the following general formula (3).

一般式（３）

General formula (3)

In General Formula (3), 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, a nitrogen 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 1 to 1 carbon atom containing a hetero atom. 12 hydrocarbon groups are shown. In addition, a hetero atom here shows N, S, O, a halogen atom, and Se. W ¹⁻ is defined in the same manner as Xa ⁻ described later, and R ^a represents a substituent selected from a hydrogen atom, an alkyl group, an aryl group, a 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. Xa ⁻ represents a counter anion. However, when the cyanine dye represented by the general formula (3) has an anionic substituent in its structure and charge neutralization is not necessary, W ¹⁻ is not necessary. Preferred Xa ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, and 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.

  The amount of the pigment or dye used as the infrared absorber is preferably 0.01 to 50% by weight, more preferably 0.1 to 10% by weight, based on the total solid content of the composition constituting the recording layer. In the case of the dye, 0.5 to 10% by weight is particularly preferable, and in the case of a pigment, 3.1 to 10% by weight is particularly preferable. When the added amount of the pigment or dye is within the above range, preferable recording sensitivity when used as a positive recording layer, and excellent uniformity and durability of the recording layer can be obtained.

[Other additive components]
In the recording layer of the lithographic printing plate precursor according to the invention, in addition to the essential components, various known additives can be used in combination with the above-described constituent components according to the purpose, if necessary.

  For example, an alkali-soluble resin other than the alkali-soluble resin having a urea bond in the side chain can be added together. As such an alkali-soluble resin, for example, an alkaline aqueous solution-soluble resin having a phenolic hydroxyl group (hereinafter sometimes referred to as “resin having a phenolic hydroxyl group”) is preferable.

  Examples of the resin having a phenolic hydroxyl group include phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin, and phenol / cresol (m-, p-, or m). Any of-/ p-mixing may be used) and novolak resins such as mixed formaldehyde resins.

  The molecular weight of the resin having a phenolic hydroxyl group is preferably 500 to 20,000 in terms of weight average molecular weight and 200 to 10,000 in terms of number average molecular weight.

  In addition, a t-butylphenol formaldehyde resin described in US Pat. No. 4,123,279 or a condensate of phenol and formaldehyde having an alkyl group having 3 to 8 carbon atoms as a substituent, such as octylphenol formaldehyde resin, is used in combination. Also good. These resins having a phenolic hydroxyl group may be used alone or in combination of two or more.

  The blending ratio of the resin having a phenolic hydroxyl group to the aqueous alkaline resin-soluble resin (resin having a phenolic hydroxyl group: alkaline aqueous resin-soluble resin) is preferably within a range of 1:10 to 10: 1 by weight. More preferably, it is in the range of 1: 5 to 5: 1. When the blending ratio is less than the numerical range, the interaction with the resin having the phenolic hydroxyl group is not sufficient, and the development latitude may be lowered, while the blending ratio falls within the numerical range. When exceeding, the chemical-resistance improvement effect of the said recording layer may not fully be acquired.

In addition to the alkali-soluble resin having a phenolic hydroxyl group, resins having the acidic groups listed in the following (A) to (F) in the main chain and / or side chain of the polymer are also preferably used as additives. be able to.

(A) Phenol group (-Ar-OH)
(B) Sulfonamide group (—SO ₂ NH—R)
(C) Substituted sulfonamide acid group (hereinafter referred to as “active imide group”)
[—SO ₂ NHCOR, —SO ₂ NHSO ₂ R, —CONHSO ₂ R]
(D) Carboxylic acid group (—CO ₂ H)
(E) Sulfonic acid group (—SO ₃ H)
(F) phosphoric acid group (-OPO ₃ H ₂₎

  In the acidic groups (A) to (F), 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. Represents.

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

Examples of the alkali-soluble resin having an acidic group selected from the acidic groups (A) to (F) include the following.
(A) 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. A novolak resin such as a condensation polymer of mixed cresol and formaldehyde, a condensation polymer of phenol and cresol (any of m-, p-, or m- / p-mixing) and formaldehyde, and 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.

  (B) As an alkali-soluble resin which has a sulfonamide group, the polymer comprised as a main structural component the minimum structural unit derived from the compound which has a sulfonamide group can be mentioned, for example. 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).

In the general formula (i) to general formula (v), X ¹ and X ² are each independently —O— or —N.
R ⁷ is represented. 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 are each independently an alkylene group having 1 to 12 carbon atoms, a cycloalkylene group, an arylene group, or an aralkylene group that may have a substituent. To express. 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 and Y ² each independently represent a single bond or CO.

  Among the compounds represented by the general formula (i) to the general formula (v), in the resin composition used for the lithographic printing plate precursor according to the invention, in particular, m-aminosulfonylphenyl methacrylate, N- (p-aminosulfonyl) Phenyl) methacrylamide, N- (p-aminosulfonylphenyl) acrylamide and the like can be preferably used.

  (C) As an alkali-soluble resin which has an active imide group, the polymer comprised as a main structural component the minimum structural unit derived from the compound which has an active imide group can be mentioned, for example. 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.

(D) 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.
(E) As an 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.
(F) As an alkali-soluble resin having a phosphoric acid group, for example, a minimum structural unit derived from a compound having at least one phosphoric acid 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 acidic groups (A) to (F) is not particularly limited to one kind, and two or more minimum structural units having the same acidic group are used, or different acidic groups. It is also possible to use a copolymer obtained by copolymerizing two or more kinds of minimum structural units having the above.

  The copolymer preferably contains 10 mol% or more of the compound having an acidic group listed in the above (A) to (F) to be copolymerized, and is contained in an amount of 20 mol% or more. It is more preferable. 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.

  As such an alkali-soluble resin, a polymerizable monomer having a phenolic hydroxyl group or a homopolymer or copolymer of a polymerizable monomer having an active imide group is preferable, and 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. .

  Further, in order to adjust the solubility of the recording layer, an onium salt, an aromatic sulfone compound, an aromatic sulfonic acid ester compound, a polyfunctional amine compound, or the like is added to a developer of an alkaline water-soluble polymer (alkali-soluble resin). It is preferable to add a so-called dissolution inhibitor that improves the dissolution inhibiting function of the resin. Among them, the solubility of the alkali-soluble resin in the state of being thermally decomposable such as onium salt, o-quinonediazide compound, sulfonic acid alkyl ester, etc., and not decomposing. It is preferable to use in combination with a substance that substantially lowers the solubility of the image portion 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 shown by (1)-(10) in [Chemical 8] [Chemical 9] described 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) -diazide sulfonic 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% by mass to 5% by mass, more preferably 0.1% by mass to 2% by mass, and particularly preferably 0.1% by mass to 1.5% by mass. It is in the range of mass%. When the recording layer has a multilayer structure, 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 the photosensitive composition contained in the recording layer of the present invention, cyclic acid anhydrides, phenols, and organic acids can be used in combination for the purpose of improving sensitivity. Further, a surfactant, an image colorant, and a plasticizer described later can also be used in the recording layer of the present invention.
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 The ratios of the sulfonic acids, sulfinic acids, alkyl, and cyclic acid anhydrides, phenols, and organic acids described in Japanese Unexamined Patent Publication No. 60-88942 and Japanese Patent Laid-Open No. 2-96755 are as follows. 0.05 mass% to 20 mass% is preferable, more preferably 0.1 mass% to 15 mass%, and particularly preferably 0.1 mass% to 1 mass%. % 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, JP-A-53-36223, JP-A-54-74728, JP-A-60-3626, JP-A-61-143748, JP-A-61-151644, and JP-A-63-58440 Mention may be made of the combinations of the described trihalomethyl compounds and salt-forming organic dyes. 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% by mass to 10% by mass, preferably 0.1% by mass to 3% by mass, based on the total solid content of the recording layer.

  Furthermore, a plasticizer is added to the recording layer of the present invention as needed in order to impart 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 Acid oligomers and polymers are used.

[Method for producing planographic printing plate precursor]
Hereinafter, a method for producing a lithographic printing plate precursor having the above-described recording layer will be described.

(Coating solvent and coating method)
The lithographic printing plate precursor to which the production method of the present invention is applied can be produced by dissolving the above-mentioned composition constituting the recording layer in a solvent and coating it on a suitable support. Further, depending on the purpose, a protective layer, a resin intermediate layer, a backcoat layer and the like which will be described later can be formed in the same manner.

Solvents used for dissolving and coating the recording layer of the lithographic printing plate precursor according to the invention include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2- Methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, Examples thereof include γ-butyrolactone and toluene, but are not limited thereto. These solvents are used alone or in combination.
The concentration of the above components (total solid content including additives) in the solvent is preferably in the range of 1% by mass to 50% by mass.
Coating, the coating amount on the support obtained after drying (solid content) may be varied according to the intended purpose, the amount of coating amount after drying of 0.5mg / m ² ~5.0mg / m ² is preferably , and more preferably it amounts to be ^{0.6mg / m 2 ~2.0mg / m 2} .

  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 of the photosensitive film deteriorate.

[Layer structure of recording layer]
The recording layer of the lithographic printing plate precursor according to the invention can be used in 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. Layers can be used, but are not limited to these.

[Preparation of lithographic printing plate precursor]
(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 a support that can be applied to a lithographic printing plate precursor, 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 cannot be specified. However, in general, the electrolyte concentration is 1% to 80% by weight solution, the liquid temperature is 5 ° C. to 70 ° C., and the current density is 5 A / dm. ^{2 to} 60 A / dm ² , voltage 1 V to 100 V, and electrolysis time 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 portion of the planographic printing plate is easily damaged, and the ink adheres to the damaged portion during printing. So-called “scratch stains” easily 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 US Pat. Nos. 3,276,868, 4,153,461, and 4,689,272. A method of treating with polyvinylphosphonic acid is used.

In the method for producing a lithographic printing plate precursor according to the invention, after performing the drying step of coating the recording layer on the support, the recording layer is coated and dried on the support, and then the temperature is 60 ° C. or higher. An aging treatment is performed for 5 hours or more in an environment of 100 ° C. or less and humidity of 60% or more and 95% or less.
Hereinafter, preferred embodiments of the recording layer forming step will be described, and preferable conditions for the drying step to the aging treatment will be described in detail.
The recording layer drying step and the aging treatment described later in the present invention may be carried out continuously or separately.

  The temperature in the drying step affects the glass transition temperature (Tg) of the formed recording layer. The recording layer Tg after drying is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, and particularly preferably 80 ° C. or higher. Moreover, 120 degrees C or less is preferable, 110 degrees C or less is more preferable, and 100 degrees C or less is especially preferable. In order to obtain such a Tg recording layer, the drying temperature is preferably 20 ° C. or higher, more preferably 25 ° C. or higher, and usually 100 ° C. or lower, preferably 80 ° C. or lower, more preferably 60 ° C. It is below ℃.

As a more preferred method, a method of adjusting the temperature of the drying step in two stages can be mentioned. In this case, the drying process is divided into two drying zones. In the first drying zone (first drying process), after coating, the drying temperature is set to 25 seconds or more after the constant-rate drying end point of the recording layer. Set the temperature range and drying time and dry. Here, the constant rate drying end point refers to the time from the start of drying until the internal diffusion rate control of the coating film in the evaporation step. Actually, the film thickness is measured over time, a graph showing the film thickness at the time of drying is drawn, and the time until the inflection point is reached can be obtained as the constant rate drying end point. The residual solvent at the time when the first drying process is completed is preferably within 10% by mass of the recording layer, and more preferably within 8% by mass. The drying temperature in the first drying step is, when the thickness of the recording layer is about 15mg / dm ² ~30mg / dm ² is preferably 25 ° C. or higher, with there preferably 60 ° C. or less More preferably, it is 45 ° C. or lower. The first drying step is preferably performed at (Tg + 20) ° C. or less, more preferably (Tg + 10) ° C. or less, where Tg is the glass transition temperature of the alkali-soluble polymer used in the recording layer.

  Subsequently, a second drying step is performed in the second drying zone. In this second drying step, the residual solvent is preferably 8% by mass or less, more preferably 6% by mass or less, and the film formation of the recording layer is completed. The drying temperature in the second drying step is preferably 40 ° C. or higher, more preferably 45 ° C. or higher, preferably 80 ° C. or lower, more preferably 75 ° C. or lower. When the drying temperature is changed between the first drying process and the second drying process, the temperature of the first drying process is preferably lower than the temperature of the second drying process.

[Aging process]
Next, the aging process will be described.
In the production method of the present invention, the aging step is carried out for 5 hours or more in an environment of a temperature of 60 ° C. to 100 ° C. and a humidity of 60% to 95%, following the recording layer drying step.
In the aging process, the compound having a polar group typified by water penetrates and diffuses from the surface of the formed recording layer, thereby improving the interaction with water in the recording layer and heating. Thus, the cohesive force can be improved, and the characteristics of the recording layer can be improved. The temperature condition in the aging process is desirably set so that the compound to be diffused vaporizes more than a certain amount, and water is a typical example of the substance to be permeated and diffused. Any compound having a hydroxyl group, a carboxyl group, a ketone group, an aldehyde group, an ester group, or the like can be used as well. Such a compound is preferably a compound having a boiling point of 200 ° C. or lower, more preferably a compound having a boiling point of 150 ° C. or lower, preferably a boiling point of 50 ° C. or higher, more preferably 70 ° C. or higher. It is. The molecular weight is preferably 150 or less, and more preferably 100 or less.

  The substance that penetrates into the recording layer is preferably water. As a method of infiltrating and diffusing water, a method of placing in a high humidity atmosphere is preferable, and the high humidity atmosphere in the present invention usually indicates that the humidity is 60% or more, but the humidity is 80% or more. Is preferred. In addition, the upper limit of humidity is preferably 95% or less, and more preferably 90% or less, from the viewpoint of sensitivity reduction.

The treatment time needs to be 5 hours or more, preferably 10 hours or more, more preferably 16 to 32 hours.
The treatment temperature is managed for the purpose of accurately controlling the preferable humidity atmosphere, and needs to be in the range of 60 ° C to 100 ° C, more preferably in the range of 60 ° C to 80 ° C. The

Hereinafter, the preferable aspect in this aging process is demonstrated concretely.
In a first preferred embodiment, after a recording layer is applied on a support and dried, the recording layer is superposed on a protective material having a water content of 1 to 7% by mass and kept under heating for a predetermined time under the above temperature conditions. It is an aspect to do. Accordingly, moisture that permeates and diffuses into the recording layer can be efficiently supplied from the protective material that contacts the surface of the recording layer.

  The shape of the lithographic printing plate precursor during the aging treatment is not particularly limited. For example, the aging treatment can be performed while continuously supplying a strip-like lithographic printing plate into the aging treatment apparatus. Further, the aging treatment can be performed once in a coiled form or cut into an appropriate size and deposited. Usually, a lithographic printing plate precursor is cut into a predetermined size and is put to practical use. Thus, it is possible to cut into a predetermined size and perform an aging process in a state where a plurality of sheets are laminated, thereby reducing the compactness of the aging apparatus. From the viewpoint of ease of handling such as packaging, subsequent packaging, and transportation. The lamination of the positive photosensitive lithographic printing plate precursor and the protective material is not particularly limited as long as the recording layer and the protective material can be in contact with each other, but the two are alternately laminated on the pallet. It is common. Hereinafter, a laminate of a lithographic printing plate precursor having a predetermined size or an alternating laminate of a lithographic printing plate precursor and a protective material may be referred to as a “deposition plate”.

Further, as a modification of the first aspect, the protective layer is placed on the surface of the recording layer of the positive photosensitive lithographic printing plate precursor, and the coil core is wound around the coil core material, and the aging treatment is performed in this state. The mode to do is mentioned.
In the case where the aging treatment is performed in a coiled state or a laminated state, the lithographic printing plate precursor is used in order to achieve a preferable humidity condition of 60% to 95% even with respect to the recording layer present in the unopened portion. It is preferable to hold an appropriate amount of water in the protective material arranged on the surface. The moisture retention amount of the protective material may vary depending on the material of the protective material, but when paper is used as the protective material, it is preferably 1% by mass or more, and more preferably 3% by mass or more. Moreover, 10 mass% or less is preferable, 7 mass% or less is still more preferable, and 5 mass% or less is especially preferable.
In addition, the moisture content of the protective material in this specification uses the value which calculated | required the state which dried the protective material at 105 degreeC for 2 hours as the moisture content rate 0%.

  Any protective material used to supply humidity can be used as long as it can hold a certain amount of moisture so that it can be absorbed / released. However, a sheet-like material is usually used and is excellent in moisture absorption and dehumidification. Preferably, cellulose such as pulp, semi-synthetic fibers such as cellulose acetate, natural fibers such as cotton and silk, synthetic rubber or resin such as polyester, nylon, polyvinyl alcohol, hydrochloric acid rubber, polyimide, and polyurethane can be used. These may be used in the form of a fibrous sheet or in the form of a foam sheet having open cells. Specifically, paper such as Japanese paper, western paper, synthetic paper, and mixed paper, woven fabric, non-woven fabric, foamed sheet, and the like can be used. Moreover, the laminated body of these sheets, the laminated body of these and another sheet-like material, etc. can be used.

The number of laminated lithographic printing plate precursors and the number of coil turns are not particularly limited as long as the protective material can be sandwiched between two or more, and can be easily selected based on manufacturing conditions and production plan. In view of the temperature rise of the conductive lithographic printing plate, the number of laminated layers is preferably 100 to 2000, and the coil shape is preferably in the range of 100 m to 2000 m.
As the heating method in the aging process, known heating means can be appropriately used depending on the aspect of the lithographic printing plate precursor and a desired temperature, for example, heating with hot air such as a dryer, heating with a heater in a temperature-controlled atmosphere, A far infrared heating device, a microwave heating device, or the like can be used.

  Further, as a second preferred embodiment, after a planographic printing plate precursor having a predetermined size superimposed on a protective material is laminated or wound into a coil shape, at least a laminated body or a coiled winding body is used. The aspect which coat | covers the whole side surface with a moisture-impermeable material, and hold | maintains under heating is mentioned. You may coat | cover the laminated body and the whole winding body with a moisture-impermeable material. By covering with a sheet or the like that does not allow permeation of a desired permeating substance (water in this embodiment) in this way, it is possible to prevent transpiration of water necessary for diffusion to the recording layer, and to easily obtain a desired humidity.

The moisture-impermeable material used here is not particularly limited as long as it has low moisture permeability and adheres closely. A sheet-like moisture-impermeable material is preferable because of easy handling. Furthermore, moisture ^{permeability, 7g / m 2 / 24hr /} mm25 ℃ less well, still more preferably, preferably ^{2g / m 2 / 24hr / mm25} ℃ or less. As materials, polytrifluorinated ethylene, polytetrafluoroethylene, polyethylene polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, ionomers and other non-breathable synthetic resins, aluminum foil and other metal sheets, and these And a moisture-proof sheet obtained by vapor-depositing a metal on a paper such as a synthetic resin sheet such as polyethylene terephthalate (PET) as a base material. Hereinafter, such a covering material made of a moisture permeable material is hereinafter referred to as a suitable, non-moisture permeable sheet or non-moisture permeable material sheet.
Thus, when the planographic printing plate precursor is coated with a moisture-impermeable sheet, there is a concern that the effect may be reduced if air enters between them. This sheet is used for the purpose of preventing the moisture of the protective material laminated or coiled together with the planographic printing plate from being released to the outside, but the support of the planographic printing plate precursor also serves as a moisture-impermeable material. Therefore, it is sufficient to cover at least the entire side surface (the portion not covered by the outermost lithographic printing plate), but the entire surface may be covered. When covering the whole, it is preferable from the viewpoint of the effect that the periphery of the sheet is in close contact with each other. Furthermore, from the viewpoint of not impairing the effect of heating, the thickness of the moisture-impermeable material sheet is preferably not so large, preferably in the range of 10 μm to 1000 μm, and more preferably in the range of 20 μm to 500 μm.

  The moisture-proof sheet has the purpose of dissipating the moisture of the protective material deposited or coiled together with the lithographic printing plate to the outside, but the lithographic printing plate itself also serves as a non-moisture permeable material. It is sufficient to cover at least the entire side surface of the coil winding (the portion not covered by the outermost lithographic printing plate). However, depending on convenience and the like, the entire deposit or coil winding may be covered. As an example of the use of a moisture-proof sheet, specifically, a mode in which a lithographic printing plate and a protective material are stacked on a pallet to form a laminate, and then, after lamination, the side or the whole is covered with a moisture-proof sheet or the like is used. Etc. Here, in order to effectively seal the laminated body, it is desirable to eliminate the opening by means such as fastening the end of the moisture-proof sheet covering the laminated body with a tape or the like. Moreover, as another aspect, the side surface or the whole of the rolled up body obtained by combining the positive photosensitive printing plate and the protective material and winding them around the coil core material is covered with a moisture-proof sheet or the like and sealed. An embodiment is mentioned.

  In the aging step, when heating the laminate or the wound body, the side surface of the laminate or the wound body can be covered with a heating element and kept under heating. By adopting this mode (third mode), aging can be performed easily and aging time can be shortened without preparing a special closed space for aging.

  As the heating element used in the third aspect, any shape or any heating mechanism can be used, but as the heating mechanism, nichrome wire or nichrome foil is meandered as a heater part. There are metal foil printed wiring, cotton fabric woven with braided copper wire or glass fiber fabric coated and impregnated with conductive paint, etc., and it is difficult to electrically insulate the entire surface of the heater. Those covered with a film sheet made of a synthetic resin having flame resistance and heat resistance can be preferably used. As the synthetic resin material, a resin material having low gas permeability such as vinyl chloride or tetrafluoroethylene resin [Teflon (registered trademark)] is preferable. Further, the heating element used for coating does not have to have a heating mechanism. For example, the coating material is an object that absorbs infrared rays, such as a black body, and is coated by irradiating infrared rays from outside the coating material. The material can also be configured to generate heat. When taking such an aspect, since there exists a possibility that a recording layer may be exposed by the infrared rays irradiated, it is necessary to use what does not permeate | transmit infrared rays as a coating | covering material. In addition, a bendable planar heating element is preferable because it can be applied to printing plates of various sizes.

  In the third aspect, the heating element is disposed on the side surface of the photosensitive lithographic printing plate deposit or roll-up, but from the viewpoint of heating efficiency, the heating element and the side surface of the photosensitive lithographic printing plate are in contact with each other. It is preferable to do so. Examples of the contact method include a method of winding a belt-like heating element around the side surface, and a method of attaching a sheet heating element having the same area as each side surface to each side surface. The heating element can also serve as the above-described moisture-impermeable material by making the material moisture-proof. As a method of tightly adhering the heating element and the side of the plate so that an air layer is not formed, the outside of the wound or attached sheet heating element is tightened with a plurality of resin, rubber, fiber or leather belts. Alternatively, there is a method in which a heat-shrinkable resin film is wound around a side surface and the film portion is heated and contracted by a dryer or the like.

Next, the heating conditions in this step will be described.
The heating means is not particularly limited as long as the environmental temperature in which the planographic printing plate precursor is placed can be maintained at a predetermined condition during the above-mentioned aging process, and a known heating means that is in contact or non-contact is used. Can do.
When using a planar heating element in a space heated to an arbitrary temperature to heat the deposited plate, measure the temperature of the deposited plate so that the temperature can be maintained after the temperature of the deposited plate reaches the target temperature. It is desirable to control the temperature by adjusting the voltage of the heating element. When heat treatment is performed using a planar heating element in a room temperature room, after mounting the planar heating element on the side of a plate or coiled material, surround the area with a heat insulating material and start from the heating element. It is desirable not to release the generated heat to the outside. At this time, it is desirable that the upper surface of the deposition plate and the surrounding surface of the coil wound up are also covered with a heat insulating material.

  Although a heat generating body may be used by a single layer, it can also be used in multiple layers for the purpose of increasing the amount of heat. It is desirable to install an automatic temperature adjusting circuit, a thermal fuse blown circuit, a heat sensitive wire short circuit detection circuit, a heat sensitive wire break detection circuit, an overheated surface detection circuit, etc. as a safety device on the heating element. According to this aspect, it is possible to improve the heating efficiency of the laminate wound body of the positive photosensitive lithographic printing plate precursor and shorten the heat treatment time.

As a fourth preferred embodiment, a method using a hot fluid for heating in the aging process can be mentioned. When holding the heating temperature in the aging process, the fluid temperature around the lithographic printing plate precursor may decrease over time. Therefore, by always circulating the surrounding fluid while bringing the thermal fluid into contact with the laminate of the lithographic printing plate precursor and the winding body, the heat transfer is promoted and the time to reach the target temperature for performing the aging process is shortened. be able to. As the thermal fluid, air is usually used, but any gas that is inert to the recording layer, such as nitrogen or argon, can be used. The speed at which the thermal fluid collides is preferably 0.2 m / s or more, more preferably 0.5 m / s or more, and particularly preferably 2 m / s or more. Moreover, 100 m / s or less is preferable, 50 m / s is still more preferable, and 20 m / s is especially preferable.
When a lithographic printing plate is piled up on a protective material containing moisture or wound up on a coil strip and subjected to an aging treatment, the moisture necessary for aging can be supplied from the protective material, so that the fluid must contain moisture. There is no need to include. On the other hand, when the aging process is performed without overlapping the protective material containing moisture, the required moisture can be supplied by setting the humidity of the fluid to 60% or higher.

  In this fourth aspect, as a preferable method in the case of causing the thermal fluid to collide with the lithographic printing plate, a lithographic printing plate having a predetermined size superimposed with a protective material containing moisture is deposited or coiled. The wound, deposited or coiled lithographic printing plate is placed in a chamber of a predetermined size and kept under heating while circulating the air in the chamber. Of these, it is preferable to deposit a lithographic printing plate of a predetermined size. As a method of circulating air, a blower or the like can be used. The opening area of the blower is desirably equal to or larger than the area on the deposit side, and it is desirable that the fluid having a constant temperature collides with the deposit almost perpendicularly. In the case of sediment, the blower is installed on one side, two side surfaces, three side surfaces, all side surfaces, or one wound on one side or both side surfaces in the case of being wound in a coil shape. Can collide. When the deposition plate is heat-treated using a blower in a space heated to an arbitrary temperature, it is preferable to supply a heating fluid to the blower suction port by a duct or the like. The supply of the thermal fluid may be performed by measuring the temperature of the lithographic printing plate precursor while adjusting the air volume and speed of the blower after the temperature reaches the target temperature and maintaining the temperature for a predetermined time. desirable.

In a fifth preferred embodiment, in the aging step, the laminate or the wound body is held under heat in a state where a heat insulating material is applied to almost the entire upper and lower surfaces of the laminate or the wound body. By applying a heat insulating material, heat transfer from both the top and bottom sides can be prevented, and all heat transfer is performed from the side. And the lower layer can have the same heat transfer conditions, and unevenness of the recording layer can be prevented. When heating a laminated body, it is preferable that a heat insulating material is applied to both upper and lower surfaces, and substantially the whole upper and lower surfaces are covered with a heat insulating material.
Although there is no restriction | limiting in particular as a heat insulating material, A thing with little dust generation property is preferable, and a synthetic resin foam, a woven fabric, a nonwoven fabric, a chip board, glass wool etc. can be used. As the heat insulating material, those having a heat passage rate of 2 w / m ² · hr · K or less, preferably 1 w / m ² · hr · K or less are preferable. When aging is performed in a laminated state, moisture is released from the protective material by heating, but the degree of release varies depending on the temperature of the deposited lithographic printing plate precursor and the moisture content of the protective material. If the temperature of the lithographic printing plate precursor is kept high, the protective material releases a large amount of water contained therein, the water concentration on the recording layer surface becomes high, and water diffusion from the recording layer surface can be accelerated. In this way, the moisture concentration of the coated surface can be controlled by the temperature of the lithographic printing plate. Therefore, when a heat insulating material is used, the entire deposited lithographic printing plate can be heated uniformly, and the recording layer It is thought that something that prevents aging unevenness can be made.

In addition, when the rewritable body of the lithographic printing plate precursor is subjected to an aging treatment, a mode in which the outer peripheral surface is covered by winding the heat insulating material on the wound winding body wound around a core material made of a heat insulating material. It is preferable to take. Therefore, in the present invention, when rolled, the outer peripheral surface is treated as the upper side and the core material side is treated as the lower side.
In the fifth aspect, the photosensitive lithographic printing plate precursor is preferably preheated through a heating furnace or the like before being formed into a laminate or a wound body. The preheating temperature is within ± 10 ° C., preferably within ± 5 ° C., particularly preferably within ± 3 ° C. with respect to the heat treatment temperature.
The planographic printing plate precursor sandwiched between the upper and lower sides by a heat insulating material may be accommodated in a heat treatment chamber and subjected to heat treatment.

In the production method of the present invention, preferred conditions vary depending on variations in the size of the drying device, aging device, desired lithographic printing plate precursor, type of alkali-soluble resin in the recording layer, film thickness, and the like. Yes, the preferred embodiment shown above can also vary.
The residual solvent (residual amount of the recording layer coating solvent) in the recording layer after the aging treatment is preferably 8% or less, more preferably 6% or less, and particularly preferably 5% or less. Moreover, 0.05% or more is preferable and 0.2% or more is still more preferable.

In the positive photosensitive lithographic printing plate thus obtained, the solubility of the recording layer on the surface in an alkaline developer is lowered, and the strength of the image area is improved. The reason for this is not necessarily clear, but it is assumed that the solubility in an alkaline developer changes depending on the state of physical or physicochemical bonding between adjacent resin molecules or between adjacent molecules via other coexisting compounds. It is considered that a highly polar compound such as a water molecule penetrates and diffuses into the recording layer to newly generate an interaction such as a hydrogen bond, resulting in a decrease in solubility in an alkali developer.
The interaction formed by the execution of these aging processes is easily released by the heat generated by infrared laser exposure as well as the interaction pre-existing in the positive recording layer. is not. Therefore, it is estimated that the planographic printing plate precursor of the present invention has improved development latitude and is excellent in small area image reproducibility.

  After the recording layer is formed, the lithographic printing plate precursor subjected to aging treatment is then subjected to image-wise exposure and development processes using an infrared laser in a conventional manner to form a lithographic printing plate and used for printing a large number of sheets.

(Undercoat layer)
The lithographic printing plate precursor according to the invention is provided with a recording layer as described above on a support, and an undercoat layer can be provided between the support and the lower layer, if necessary. 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 naphthyl phosphonic acid, alkyl phosphonic acid, glycero phosphonic acid, methylene diphosphonic acid and ethylene diphosphonic acid, phenyl phosphoric acid, naphthyl phosphoric acid, alkyl phosphoric acid and glycerophosphoric acid which may have a substituent 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 within the range of 0.005% by mass to 10% by mass of the organic compound can be applied by various methods. In the latter method, the concentration of the solution is in the range of 0.01% by mass to 20% by mass, preferably 0.05% by mass to 5% by mass, and the immersion temperature is 20 ° C. to 90 ° C., preferably 25 ° C. The immersion time is in the range of ˜50 ° C., and the immersion time is in the range of 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 basic substances such as ammonia, triethylamine, potassium hydroxide, and acidic substances such as hydrochloric acid and phosphoric acid. A yellow dye can also be added to improve the tone reproducibility of the image recording material. The coverage of the undercoat ^{layer, 2mg / m 2 ~200mg / m} 2 is is suitable, and preferably from ^{5mg / m 2 ~100mg / m 2} . If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. The same is true even if it is larger than 200 mg / m ² .

  The lithographic printing plate precursor obtained by the production method of 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. A semiconductor that emits infrared light having a wavelength of 700 nm 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. It is preferable that the exposure time per pixel is preferably within 20μ seconds, it is preferable energy irradiated to the recording material is ^{10mJ / cm 2 ~500mJ / cm 2} .

  The developer that can be applied to the lithographic printing plate precursor obtained by the production method of the present 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. It is. A conventionally known aqueous alkali solution can be used as the developer (hereinafter referred to as developer including the replenisher). For example, sodium silicate, potassium, tribasic sodium 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. Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are 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 the content of SiO ₂ is 1% by mass to 4% by mass of an aqueous solution of sodium silicate, or Japanese Examined Patent Publication No. 57-7427. As described in the publication, [SiO ₂ ] / [M] is 0.5 to 0.75 (ie, [SiO ₂ ] / [M ₂ O] is 1.0 to 1.5), the concentration of SiO ₂ is to 4 wt% 1 wt%, and the total alkali metal grayed the developing solution is present therein The beam atoms with respect 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 development processing of the lithographic printing plate material is performed using this developer, the surface of the recording layer is not deteriorated and the inking property of the recording layer can be maintained in a good state. In addition, the lithographic printing plate precursor obtained by the production method of the present invention has a wider development latitude than a general one, but the non-silicate developer contains a non-reducing sugar having a buffering property that suppresses pH fluctuations. Therefore, it is advantageous compared to the case of using a developing solution containing silicate. For this reason, the reproducibility of the fine area image is further improved by using the non-silicate developer for developing the lithographic printing plate precursor according to the invention. 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 more 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, or a glycoside in which a reducing group and a non-saccharide 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% by mass to 30% by mass, and more preferably 1% by mass 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 conventionally 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, published 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 image forming material developed using the developer and the replenisher is post-processed with a desensitizing solution containing washing water, a rinsing solution containing a surfactant or the like, gum arabic or a starch derivative. As the post-treatment when the image forming material is used as a printing plate, these treatments 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 salts 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 lithographic printing plate precursor according to the 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 obtained by the production method of the present invention, an image portion unnecessary for the lithographic printing plate obtained by image exposure, development, washing and / or rinsing and / or gumming (for example, an original image). If there is a film edge mark or the like of the film, unnecessary image portions are 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. As described in JP-A-59-174842, a method of developing after irradiating an unnecessary image portion with an actinic ray guided by an optical fiber 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 g / m ^{2 to} 0.8 g / m ² (dry mass). The lithographic 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 depend on the type of components forming the image, but are preferably in the range of 180 ° C. to 300 ° C. for 1 minute to 20 minutes.

  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 is used. In such a case, a so-called desensitizing treatment such as gumming can be omitted. The planographic printing plate obtained by such processing is applied to an offset printing machine or the like and used for printing a large number of sheets. Since the lithographic printing plate precursor obtained by the production method of the present invention is excellent in reproducibility of a small area image obtained by an FM screen or the like, a printed matter with high definition and excellent image quality can be obtained.

  EXAMPLES Hereinafter, although this invention is demonstrated according to an Example, the scope of the present invention is not limited to these Examples.

(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 and water as a polishing slurry liquid to a surface of an aluminum plate, it is mechanically rotated by a roller-like nylon brush. 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 has an electrochemical surface roughening treatment using a carbon electrode as a 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) 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 by 0.20 g / m ² , 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 by spraying was performed with a 15% by weight aqueous solution of sulfuric 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) Alkaline etching treatment An aluminum plate is etched by spraying at 32 ° C. with a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass, and the aluminum plate is dissolved at 0.10 g / m ² , so 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 melted 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 at 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. All electrolytes 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 for omitting the steps (g), (h), and (i) among the above steps.

<Support C>
A support C was prepared by sequentially performing the steps except that the steps (a), (g), (h), and (i) were omitted from the above steps.
<Support D>
Of the above steps, the steps (a), (d), (e), and (f) are omitted except that the steps are performed in order, and the total amount of electricity in step (g) is 450 C / dm ^2. Thus, a support D was produced.
The support A, the support B, the support C, and the support D obtained as described above were subsequently 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 / m2.

[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 to obtain a support with an undercoat layer. The coating amount after drying was 15 mg / m ² .
(Undercoat liquid)
-0.3 g of the following polymer compound (I or II)
・ 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 .
Then, after apply | coating the coating liquid B for uppermost layers of the following composition with the wire bar to the obtained support body with a lower layer, it dried at 140 degreeC for 60 second, and made the total application quantity 1.07g / m < ² >. Thereafter, the lithographic printing plate precursor was aged under the conditions shown in Table 5 below, and positive lithographic printing plate precursors of Examples 1 to 3 and Comparative Example 1 were obtained. A lithographic printing plate precursor that was not subjected to aging treatment after coating and drying was designated as Comparative Example 2.

<Coating liquid A for lower layer>
・ Alkali-soluble resin listed in Table 1. 2.13 g
・ Cyanine dye P (structure shown below) 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 (the following structure) 0.019 g
・ Methyl ethyl ketone 2.63g
・ 1-methoxy-2-propanol 5.27g

[Examples 4 to 6, Comparative Examples 3 and 4]
After applying the coating liquid C having the following composition to the support with an undercoat layer obtained by the same method as in Examples 1 to 3 with a wire bar, drying was performed at 140 ° C. for 60 seconds to obtain a total coating amount of 1.00 g. / M ² . Thereafter, the lithographic printing plate precursor was aged under the conditions shown in Table 5 below to obtain positive lithographic printing plate precursors of Examples 4 to 6 and Comparative Example 3. A lithographic printing plate precursor that was not subjected to aging treatment after coating and drying was designated as Comparative Example 4.

<Coating liquid C>
-0.75g of alkali-soluble resins listed in Table 1
-M-cresol / p-cresol novolac 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 (structure shown below) 0.017g
・ Victoria Pure Blue (Dye with BOH counter anion as 1-naphthalenesulfonic acid anion) 0.015g
・ Γ-Butyllactone 10g
・ Methyl ethyl ketone 10g
1-methoxy-2-propanol 1g

[Examples 7 to 9, Comparative Examples 5 and 6]
After applying the coating liquid D having the following composition to the support with the undercoat obtained by the same method as in Examples 1 to 3 with a wire bar, drying was performed at 140 ° C. for 60 seconds to obtain a total coating amount of 1.40 g. / M ² . Thereafter, the lithographic printing plate precursor was aged under the conditions shown in Table 6 below to obtain positive lithographic printing plate precursors of Examples 7 to 9 and Comparative Example 5. A lithographic printing plate precursor that was not subjected to aging treatment after coating and drying was designated as Comparative Example 6.

<Coating liquid D>
・ 2.072 g of alkali-soluble resin listed in Table 1
・ Cyanine dye P (structure shown below) 0.052g
・ Ethyl violet 6-naphthalenesulfonic acid 0.078g
・ Methyl ethyl ketone 25.30g

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

(Evaluation of development latitude)
The obtained positive type lithographic printing plate precursors of Examples and Comparative Examples were drawn (exposed) in a test pattern image on a Trendsetter 800 manufactured by Creo under the conditions of a beam intensity of 10.0 W and a drum rotation speed of 250 rpm. .
Next, a solution in which carbon dioxide gas was blown into the developer DT-2R manufactured by Fuji Photo Film Co., Ltd. in water (1: 9) until the electrical conductivity reached 37 mS / cm, and a finisher manufactured by Fuji Photo Film Co., Ltd. Development was carried out using a PS processor LP-940HII manufactured by Fuji Photo Film Co., Ltd., which was prepared by diluting FG-1 with water (1: 1), while maintaining the liquid temperature at 30 ° C. for 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.
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 6.

(Evaluation of chemical resistance)
A cleaner solution (manufactured by Fuji Photo Film Co., Ltd .: “Plate Cleaner CL2”) was dropped onto the positive and negative lithographic printing plate precursors of Examples and Comparative Examples, and the concentration of the dropping portion after 1 minute was added. Changes were compared visually. The case where there was no change in density was indicated as ◯, the case where the change in density was slightly observed was indicated as Δ, and the case where the change was greatly changed was indicated as x. The results are shown in Table 6.

(Halftone image reproducibility)
The obtained positive type lithographic printing plate precursor was drawn on an image of a 175 lpi / 2400 dpi / 1% dot test pattern on a Trend setter 3244 manufactured by Creo under the conditions of a beam strength of 10.0 W and a drum rotation speed of 250 rpm ( Exposure).
After exposure under the above conditions, Fuji Photo Film Co., Ltd. developer DT-2 (diluted to a conductivity of 47 mS / cm) and Fuji Photo Film Co., Ltd. Finisher-FP-2W (diluted 1: 1). The film was developed using a PS processor-LP-940H manufactured by Fuji Photo Film Co., Ltd., with a developing temperature of 12 seconds. Thereafter, it was evaluated whether or not the 1% halftone dot portion was missing with a 50 times magnifier.
In addition, the thing in which the missing part of the halftone dot part was seen was set as (circle) and the thing in which the missing part of the halftone dot part was seen as x.

  In Table 6, resin A is m / p cresol novolak resin (m / p ratio = 6/4, Mw: 5000) resin B is N- (4-aminosulfonylphenyl) methacrylamide / acrylonitrile / methyl methacrylate ( Molar ratio 36:34:30, weight average molecular weight 50,000).

  As is apparent from Table 6, the lithographic printing plate precursors shown in Examples 1 to 9 obtained by the production method of the present invention are good in comparison with Comparative Examples 1 to 6 in that there is no practical problem. Good dot image reproducibility was obtained while maintaining excellent scratch resistance, development latitude, and cleaner resistance. On the other hand, an alkali-soluble resin having the same composition as the alkali-soluble resin used in the recording layer of the lithographic printing original plate of the present invention was used, and unlike the lithographic printing original plate of the present invention, a lithographic printing original plate was produced without aging. In this case, as shown in Comparative Example 2, Comparative Example 4, and Comparative Example 6, the development latitude was insufficient, and good halftone image reproducibility could not be obtained. Further, even when a lithographic printing original plate is produced by the same production method as the lithographic printing original plate of the present invention, when Resin A and Resin B are used for the recording layer, Comparative Example 1 and Comparative Example 3 and Comparative Example 5, the development latitude is insufficient. In Comparative Examples 1 and 5, good cleaner resistance cannot be obtained. In Comparative Example 3, a good halftone image is obtained. Reproducibility could not be obtained.

Claims (1)

A lithographic printing plate comprising a recording layer containing, on a support, an alkali-soluble resin containing a monomer unit having a phenyl group substituted by a substituent represented by the following general formula (1), and an infrared absorber. A method for producing an original plate,
A lithographic printing plate precursor characterized in that after the recording layer is coated on the support and dried, it is subjected to an aging treatment for 5 hours or more in an environment of a temperature of 60 ° C. to 100 ° C. and a humidity of 60% to 95%. Production method.

General formula (1)
Z ¹ , Z ² and Z ³ each independently represent a monovalent substituent consisting of a hydrogen atom or a non-metal atom.