JP2009237332A - Original plate of planographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an original plate of a planographic printing plate having high sensitivity and making compatible both high printing durability and the suppression of the generation of a development scum. <P>SOLUTION: The original plate of the planographic printing plate comprises a photosensitive layer containing a sensitized dye, a polymerization initiator, a polymerizable compound and a binder polymer successively layered on a support, wherein the binder polymer contains a polyurethane resin having a reduced specific viscosity of 50 ml/g to 250 ml/g. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lithographic printing plate precursor. More specifically, the present invention relates to a negative type lithographic printing plate precursor capable of writing with high sensitivity by laser light.

  Conventionally, PS plates having a structure in which a lipophilic photosensitive resin layer is provided on a hydrophilic support have been widely used as photosensitive lithographic printing plate precursors. As the plate making method, a desired printing plate is usually obtained by dissolving and removing non-image parts after mask exposure (surface exposure) through a lithographic film.

  In recent years, digitization techniques that electronically process, store, and output image information using a computer have become widespread. Various new image output methods corresponding to such digitization techniques have come into practical use. As a result, computer-to-plate (CTP) technology that scans highly directional light such as laser light according to digitized image information and directly manufactures printing plates without going through a lithographic film has attracted attention. Obtaining a lithographic printing plate precursor adapted to this is an important technical issue.

  As such a lithographic printing plate precursor capable of scanning exposure, an oleophilic photosensitive resin layer containing a photosensitive compound capable of generating active species such as radicals and bronzed acids by laser exposure on a hydrophilic support (hereinafter referred to as “lithographic printing plate precursor”) , Which is also referred to as a photosensitive layer) has been proposed and is already on the market. This lithographic printing plate precursor is subjected to laser scanning exposure based on digital information to generate active species only in the laser irradiation area, which causes physical or chemical changes in the photosensitive layer and insolubilization, and subsequent development processing. A negative lithographic printing plate can be obtained. In particular, a photopolymerization type photosensitizer comprising a photopolymerization initiator excellent in photosensitive speed, a compound having a polymerizable ethylenically unsaturated double bond, and a binder polymer soluble in an alkali developer on a hydrophilic support. A lithographic printing plate precursor provided with a layer, and optionally an oxygen-blocking protective layer, is excellent in productivity, is easy to develop, and has good printing performance because of its advantages such as good resolution and thickness. A printing plate having

  The polymerizable composition that forms the photosensitive layer of such a lithographic printing plate precursor rapidly cures the energy application region to form a high-strength film, and dissolves quickly in an unexposed area with an alkali developer. The property to be removed is required.

  Conventionally, a polyurethane resin binder containing an alkali-soluble group has been used in such a photosensitive polymerizable composition for the purpose of improving the cured film strength and increasing the printing durability of an image area in a lithographic printing plate ( For example, see Patent Documents 1 and 2.) As the alkali-soluble group contained in such a polyurethane resin binder, dimethylolpropionic acid and dimethylolbutanoic acid are generally used, but the polyurethane resin binder has a high cohesiveness attributed to the urethane bond portion. Therefore, the developability is not sufficient, and there is a concern that development residue is deposited over time in the development layer and may adhere to the lithographic plate after plate making and cause stains. When used in the photosensitive layer of a lithographic printing plate precursor There is a problem that it is difficult to obtain excellent image forming properties.

  For such problems, for example, in urethane resin, for the purpose of improving alkali developability, a method such as using a carboxylic acid unit having a specific structure or using a compound that generates an acid group by hydrolysis as a raw material. Thus, a technique for introducing a unit for the purpose of assisting developer solubility in a urethane resin has been proposed (see, for example, Patent Document 3). In the polymerizable composition containing the urethane resin obtained by such a method, alkali developability is improved, and precipitation with time such as development residue in the developer is effectively suppressed. However, by improving the solubility in an alkali developer, it affects the excellent film properties inherently possessed by the polyurethane resin, and the film properties of the resulting film are reduced. When used as the photosensitive layer of a lithographic printing plate precursor, There is a concern of problems such as a decrease in printing durability.

  Further, in FM screen printing, when performing multi-channel laser recording by the cylindrical outer surface exposure method, there is a problem that recording unevenness synchronized with the scanning pitch appears in the printed matter, that is, banding occurs.

Thus, the strength of the cured film and the developability of the uncured area are generally contradictory properties, but the characteristics of the polymerizable composition used as the photosensitive layer of the lithographic printing plate precursor are the printing durability of the image area. In order to affect the soiling property of the non-image area, a lithographic printing plate precursor using a polymerizable composition capable of satisfying both of these conditions is desired.
Japanese Patent Publication No.8-12424 Japanese Patent Application Laid-Open No. 1-271741 JP 2006-225432 A

  An object of the present invention, which has been made in consideration of the problems in the prior art, is to provide a lithographic printing plate precursor that has high sensitivity and achieves both high printing durability and suppression of development residue.

  As a result of intensive studies to achieve the above object, the present inventor has found that the above object can be achieved by using a polyurethane resin having a specific reduced specific viscosity, and has achieved the present invention.

That is, the lithographic printing plate precursor of the present invention is obtained by sequentially laminating a sensitizing dye, a polymerization initiator, a polymerizable compound, and a photosensitive layer containing a binder polymer on a support,
The binder polymer contains a polyurethane resin having a reduced specific viscosity of 50 ml / g to 250 ml / g.

  In the present invention, it is preferable that the binder polymer further contains an acrylic resin, and the mass ratio of the polyurethane resin and the acrylic resin contained in the binder polymer is in the range of 1: 9 to 5: 5.

In the present invention, the photosensitive layer preferably contains an organic pigment.
In the present invention, it is preferable that a protective layer is further laminated on the photosensitive layer.

Although the mechanism of action of the present invention is not clear, it is presumed as follows.
In the lithographic printing plate precursor according to the invention, the binder polymer contained in the photosensitive layer contains a polyurethane resin having a specific reduced specific viscosity, so that the photosensitive layer is cured with high sensitivity, and development debris generation during development is suppressed. The high printing durability of the lithographic printing plate can be obtained.
The reason for this is not clear, but the polyurethane resin has a reduced specific viscosity exceeding the specified range of the present invention, so that the film has sufficient film strength and printing durability, and the reduced specific viscosity below the specified range is a polymer. It is presumed that the cohesive force between the chains is not increased more than necessary, and excellent developability is maintained.

On the other hand, in a preferred embodiment of the lithographic printing plate precursor according to the invention, the binder polymer further contains an acrylic resin, and when the mass ratio of the polyurethane resin and the acrylic resin contained in the binder polymer is in the above range, High printing durability due to excellent film strength, compatibility with polymerizable compounds, and high sensitivity due to acrylic resin with excellent polymerizability can be achieved.
The reason for this is not clear, but polyurethane resin has a very strong cohesive force between resin chains, so it is poorly compatible with polymerizable compounds. When polyurethane resin is used alone, crosslinking with the polymerizable compound is efficient for film curing. It is presumed that it may not work.

Furthermore, in a preferred embodiment of the lithographic printing plate precursor according to the invention, when the photosensitive layer contains an organic pigment, it has high sensitivity and maintains excellent developability even during long-term storage.
The reason for this is not clear, but it is presumed that organic pigments are highly sensitive because they have little polymerization inhibiting action like colored dyes, and that organic pigments form an infiltration path for a developer and exhibit excellent developability.

  According to the present invention, it is possible to provide a lithographic printing plate precursor that has high sensitivity and achieves both high printing durability and suppression of development debris generation.

  Hereinafter, the present invention will be described in detail.

The lithographic printing plate precursor according to the invention is obtained by sequentially laminating a sensitizing dye, a polymerization initiator, a polymerizable compound, and a photosensitive layer containing a binder polymer on a support, and the binder polymer has a reduced specific viscosity. Contains 50 ml / g to 250 ml / g of polyurethane resin.
When the lithographic printing plate precursor has the above-described configuration, it is cured with high sensitivity by applying energy to form a high-strength film, improving the printing ability and suppressing development debris generation in the developer after development. .

Moreover, such a lithographic printing plate precursor can be suitably applied to FM screen printing.
Here, the FM screen (Frequency Modulation Screening) is a printing method based on a halftone dot pattern using a frequency modulation technique, and expresses shading with the density of dots. Specifically, the density of the recorded image is expressed by the collection density of irregular dots having no regularity, and is composed of relatively small and small dots such as 2 × 2 total 4 dots. Gradation is expressed by dispersing the image in a two-dimensional plane.

  In FM screen printing, when multi-channel laser recording is performed by a cylindrical outer surface exposure method, a phenomenon in which recording unevenness synchronized with a scanning pitch appears on a printed matter, that is, banding may occur. This banding is considered to be caused by variations in output between channels when scanning a plurality of channels for each drum revolution, overlapping of scanning pitches in multiple channels, and the like.

On the other hand, by using the planographic printing plate precursor of the present invention for FM screen printing, the occurrence of banding is suppressed.
The reason is not clear, but is presumed as follows.
The following two are considered as generation mechanisms of FM banding. [1] Due to insufficient small dot printing durability of the lithographic printing plate, dots on the channel for which sufficient exposure energy was not given due to output variation between channels disappeared during printing, and on the printed matter. White streaks. [2] Since the developability of the lithographic printing plate is insufficient, a semi-cured portion remains in a poorly developed area around the dots cured by exposure, and this is unevenly removed during printing and becomes uneven.
In the present invention, it is considered that the banding due to the above [1] can be suppressed because the photosensitive layer contains a polyurethane resin in an appropriate range to have sufficient sensitivity and small dot printing durability. Furthermore, it is considered that by setting the reduced specific viscosity of the polyurethane resin within the range of the present invention, both good printing durability and developability can be achieved, and banding due to the above [2] can be suppressed.

  Hereinafter, each element constituting the planographic printing plate precursor will be sequentially described.

[Photosensitive layer]
As described above, the photosensitive layer contains a sensitizing dye, a polymerization initiator, a polymerizable compound, and a binder polymer, and may contain other components as necessary.
The binder polymer includes a polyurethane resin having a reduced specific viscosity of 50 to 250 ml / g.
Hereinafter, each component constituting the photosensitive layer will be sequentially described.

<Binder polymer>
―Specific polyurethane resin―
As described above, the binder polymer includes a polyurethane resin having a reduced specific viscosity of 50 to 250 ml / g (hereinafter sometimes referred to as “specific polyurethane resin”), and includes other resins as necessary.
Further, the reduced specific viscosity of the specific polyurethane resin is preferably 50 to 250 ml / g, more preferably 75 to 225 ml / g, and more preferably 100 to 200 ml / g.
The reduced specific viscosity in this specification is a value measured by the following measuring method.

(Measurement method of reduced specific viscosity)
A “sample solution” is prepared by dissolving a polyurethane resin as a sample in methyl ethyl ketone (MEK) to obtain a 15 wt (%) solution.

20.00 g of the above “sample solution” is placed in a 50 ml volumetric flask and weighed accurately and quickly to the nearest 0.0001 g. Thereafter, 15 ml of methyl ethyl ketone (MEK) is put into a volumetric flask with a whole pipette, and then stoppered and further sealed with Cylon tape.
Then, the solution and MEK used for measuring up are allowed to stand for 20 minutes in a constant temperature bath at 25 ° C., and then measured up to 50 ml using MEK adjusted to 25 ° C. to prepare a “diluted sample solution”.
Put this “diluted sample solution” into the Ubbelohde viscometer without filtration (the amount at the center of the two marked lines), and cover the viscometer with a ceilon tape for 30 minutes in a thermostatic chamber at 30 ° C. Allow to stand and measure the outflow time of the “diluted sample solution”. The measurement is carried out three times, and the average value is defined as t _s (s).
Moreover, the same measurement is performed only for methyl ethyl ketone (this is referred to as “blank liquid”), and an average value measured three times is defined as t _b (s).

The reduced specific viscosity η _red (ml / g) is obtained by the following formula.
_{Formula: η red = (t s -t} b) / (t b × c)
Here, c is the concentration (g / ml) of the polyurethane resin contained in the “diluted sample solution”. The weighed value (g) of the “sample solution” and the concentration of the polyurethane resin contained in the “sample solution” ( Mass%).

((Method for adjusting the reduced specific viscosity)
As a method for obtaining a polyurethane resin having a specific reduced specific viscosity, there are a method for adjusting the reaction temperature of the urethanization reaction, a method for adjusting the reaction time, and the like. The reaction temperature is preferably 50 to 180 ° C, more preferably 60 to 150 ° C, and particularly preferably 60 to 130 ° C. The reaction time is preferably 2 to 10 hours, more preferably 4 to 10 hours, and particularly preferably 6 to 10 hours. By performing the urethanization reaction under the above conditions, the polyurethane resin having the reduced specific viscosity of the present invention excellent in developability and printing durability can be obtained while suppressing gelation.

(Polyurethane resin)
The specific polyurethane resin is a polyurethane resin having a reduced specific viscosity within the above range. As such a polyurethane resin, a polyurethane resin composed of a diisocyanate compound and a diol compound can be used. Specifically, the specific polyurethane resin is a reaction product of at least one diisocyanate compound represented by the following general formula (1) and at least one diol compound represented by the general formula (2). The structural unit represented is the basic skeleton.
OCN-X ⁰ -NCO (1)
^HO-Y 0 -OH (2)
In the general formulas (1) and (2), X ⁰ and Y ⁰ each independently represent a divalent organic residue.

Among these, specific polyurethane resins preferably used in the present invention include the following.
Specific examples include polyurethane resins obtained by polyaddition reaction of a diisocyanate compound, a diol compound having at least one carboxyl group, and other diol compounds having no carboxyl group.
Moreover, in this invention, the polyurethane resin which has a polymeric group (crosslinkable group) in a side chain can be used. High press life can be obtained by introducing a crosslinkable group into the side chain.
Here, the crosslinkable group is a group that crosslinks the binder in the course of a radical polymerization reaction that occurs in the recording layer when the negative lithographic printing plate is exposed. Although it will not specifically limit if it is a group of such a function, For example, an ethylenically unsaturated bond group, an amino group, an epoxy group etc. are mentioned as a functional group which can be addition-polymerized. Moreover, the functional group which can become a radical by light irradiation may be sufficient, and as such a crosslinkable group, a thiol group, a halogen group, an onium salt structure etc. are mentioned, for example. Especially, an ethylenically unsaturated bond group is preferable and the functional group represented by the following general formula (41)-(43) is especially preferable.

In the general formula (41), R ^{1 to} R ³ each independently represents a hydrogen atom or a monovalent organic group, and R ¹ is preferably a hydrogen atom or an alkyl which may have a substituent. A hydrogen atom or a methyl group is preferable because of high radical reactivity. R ² and R ³ are each independently a hydrogen atom, a halogen atom, an amino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an optionally substituted alkyl group, or a substituted group. An aryl group that may have a group, an alkoxy group that may have a substituent, an aryloxy group that may have a substituent, an alkylamino group that may have a substituent, and a substituent An arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, a substituent An alkyl group which may have a substituent and an aryl group which may have a substituent are preferable because of high radical reactivity.

In the general formula (41), X represents an oxygen atom, a sulfur atom, or N (R ¹² ) —, and R ¹² represents a hydrogen atom or a monovalent organic group. Here, R ¹² includes a hydrogen atom, an alkyl group which may have a substituent, and the like, and among them, a hydrogen atom, a methyl group, an ethyl group, and an isopropyl group are preferable because of high radical reactivity.

Here, the substituent for substituting the alkyl group includes alkyl group, alkenyl group, alkynyl group, aryl group, alkoxy group, aryloxy group, halogen atom, amino group, alkylamino group, arylamino group, carboxyl group, alkoxycarbonyl. Group, sulfo group, nitro group, cyano group, amide group, alkylsulfonyl group, arylsulfonyl group and the like.
In the general formula (42), R ^{4 to} R ⁸ each independently represents a hydrogen atom or a monovalent organic group, and R ^{4 to} R ⁸ are preferably a hydrogen atom, a halogen atom, an amino group, or a dialkyl. Amino group, carboxyl group, alkoxycarbonyl group, sulfo group, nitro group, cyano group, alkyl group which may have a substituent, aryl group which may have a substituent, alkoxy which may have a substituent A group, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent, an arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, Examples include an arylsulfonyl group which may have a substituent. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, an alkyl group which may have a substituent, and an aryl which may have a substituent Groups are preferred.

In R ^{4 to} R ⁸ , the substituent further substituted is exemplified by the same substituents as those further substituted in the general formula (41). Y represents an oxygen atom, a sulfur atom, or N (R ¹² ). R ^12, when the R ¹² of the general formula (41) and are synonymous, and preferred examples are also the same.

In the general formula (43), R ⁹ preferably includes a hydrogen atom or an alkyl group which may have a substituent, and in particular, a hydrogen atom or a methyl group has high radical reactivity. To preferred. R ¹⁰ and R ¹¹ are each independently a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, or an alkyl group which may have a substituent. An aryl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent, a substituent An arylamino group that may have, an alkylsulfonyl group that may have a substituent, an arylsulfonyl group that may have a substituent, and the like, among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, An alkyl group which may have a substituent and an aryl group which may have a substituent are preferable because of high radical reactivity.

Here, in R ¹⁰ and R ¹¹ , the substituent further substituted is exemplified by the same substituents as those further substituted in the general formula (41). Z represents an oxygen atom, a sulfur atom, N (R ¹² ), or an optionally substituted phenylene group. R ^12, when the R ¹² of the general formula (41) and are synonymous, and preferred examples are also the same.
The diisocyanate compound and diol compound, which are raw materials for the polyurethane resin, will be described below.

(I) Diisocyanate Compound Examples of the diisocyanate compound include diisocyanate compounds represented by the following formula (4).

OCN-L-NCO (4)

  In formula (4), L represents a divalent aliphatic or aromatic hydrocarbon group which may have a substituent. If necessary, L may have other functional groups that do not react with isocyanate groups, such as carbonyl, ester, urethane, amide, and ureido groups. More specifically, L is a divalent aliphatic or aromatic hydrocarbon group which may have a single bond or a substituent (for example, alkyl, aralkyl, aryl, alkoxy and halogeno groups are preferred). Indicates. Preferably an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 15 carbon atoms, and more preferably an alkylene group having 1 to 8 carbon atoms is shown. If necessary, L may have another functional group that does not react with an isocyanate group, for example, carbonyl, ester, urethane, amide, ureido, or ether group.

  Specific examples include the following. That is, 2,4-tolylene diisocyanate, dimer of 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate Aromatic diisocyanate compounds such as 1,5-naphthylene diisocyanate, 3,3′-dimethylbiphenyl-4,4′-diisocyanate; hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, dimer acid diisocyanate, etc. Aliphatic diisocyanate compounds; isophorone diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4 (or 2,6) diisocyanate Nitrate, cycloaliphatic diisocyanate compounds such as 1,3- (isocyanatomethyl) cyclohexane, etc .; reaction product of diol and diisocyanate such as adduct of 1 mol of 1,3-butylene glycol and 2 mol of tolylene diisocyanate The diisocyanate compound etc. which are are mentioned.

  A diisocyanate compound may be used independently and may be used in combination of 2 or more type. It is preferable to use a combination of two or more in terms of the balance between printing durability and stain resistance, and at least one aromatic diisocyanate compound (L is an aromatic group) and aliphatic diisocyanate compound (L is an aliphatic group). It is particularly preferred to use each species.

  The amount of diisocyanate used is preferably 0.8 to 1.2, more preferably 0.9 to 1.1, when the total amount of diol compounds is 1 in terms of molar ratio. If the diisocyanate compound is used in excess relative to the diol compound, and the isocyanate group remains at the polymer end, the isocyanate group finally remains by treating with an alcohol or amine after completion of the urethanization reaction. It is preferable that they are synthesized in a form that does not.

(Ii) Diol compound having at least one carboxyl group As the diol compound having at least one carboxyl group, the diol compound of formula (5), (6), (7) and / or tetracarboxylic dianhydride is used. Examples thereof include compounds opened with a diol compound. The diol compound used to ring-open the carboxylic dianhydride can be used.

In the formulas (5) to (7), R ¹ is a hydrogen atom, a substituent (for example, cyano, nitro, halogen atom (—F, —Cl, —Br, —I), —CONH ₂ , —COOR ¹¹³ , — Each group such as OR ¹¹³ , —NHCONHR ¹¹³ , —NHCOOR ¹¹³ , —NHCOR ¹¹³ , —OCONHR ¹¹³ (wherein R ¹¹³ represents an alkyl group having 1 to 10 carbon atoms and an aralkyl group having 7 to 15 carbon atoms). An alkyl group, an aralkyl group, an aryl group, an alkoxy group, or an aryloxy group, which may have a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group having 6 to 15 carbon atoms. . L ¹⁰ , L ¹¹ and L ¹² may be the same or different, and may have a single bond or a substituent (for example, alkyl, aralkyl, aryl, alkoxy and halogeno groups are preferred). A divalent aliphatic or aromatic hydrocarbon group is shown. Preferably an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 15 carbon atoms, and more preferably an alkylene group having 1 to 8 carbon atoms is shown. If necessary, L ¹⁰ , L ¹¹ , and L ¹² may have other functional groups that do not react with isocyanate groups, such as carbonyl, ester, urethane, amide, ureido, and ether groups. A ring may be formed by 2 or 3 of R ¹ , L ¹⁰ , L ¹¹ and L ¹² . Ar represents a trivalent aromatic hydrocarbon group which may have a substituent, preferably an aromatic group having 6 to 15 carbon atoms.

  Specific examples of the diol compound having a carboxyl group represented by the formula (5), (6) or (7) include those shown below.

  3,5-dihydroxybenzoic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (2-hydroxyethyl) propionic acid, 2,2-bis (3-hydroxypropyl) propionic acid, Bis (hydroxymethyl) acetic acid, bis (4-hydroxyphenyl) acetic acid, 2,2-bis (hydroxymethyl) butyric acid, 4,4-bis (4-hydroxyphenyl) pentanoic acid, tartaric acid, N, N-dihydroxyethylglycine N, N-bis (2-hydroxyethyl) -3-carboxy-propionamide and the like.

  Moreover, as a preferable tetracarboxylic dianhydride used in the production | generation of the at least 1 sort (s) of diol compound which has an at least 1 carboxyl group, what is shown by Formula (8), (9), (10) is mentioned.

In the formulas (8) to (10), L ²¹ may have a single bond or a substituent (for example, alkyl, aralkyl, aryl, alkoxy, halogeno, ester, or amide groups are preferred). An aliphatic or aromatic hydrocarbon group, —CO—, —SO—, —SO ₂ —, —O— or —S— is shown. Preferably, it represents a single bond, a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms, —CO—, —SO ₂ —, —O— or —S—. R ² and R ³ may be the same or different and each represents a hydrogen atom, alkyl, aralkyl, aryl, alkoxy, or halogeno group. Preferably, a hydrogen atom, a C1-C8 alkyl, a C6-C15 aryl, a C1-C8 alkoxy, or a halogeno group is shown. ^{Two of} L ²¹ , R ² and R ³ may be bonded to form a ring. R ⁴ and R ⁵ may be the same or different and each represents a hydrogen atom, alkyl, aralkyl, aryl or halogeno group. Preferably a hydrogen atom, a C1-C8 alkyl, or a C6-C15 aryl group is shown. Two of L ²¹ , R ⁴ and R ⁵ may be bonded to form a ring. L ²² and L ²³ may be the same or different and each represents a single bond, a double bond, or a divalent aliphatic hydrocarbon group. Preferably a single bond, a double bond, or a methylene group is shown. A represents a mononuclear or polynuclear aromatic ring. An aromatic ring having 6 to 18 carbon atoms is preferable.

Specific examples of the compound represented by the formula (8), (9) or (10) include those shown below.
That is, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride, 2,3,
6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,4′-sulfonyldiphthalic dianhydride, 2,2-bis (3,4 -Dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 4,4 '-[3,3'-(alkylphosphoryldiphenylene) -bis (iminocarbonyl)] diphthal Aromatic tetracarboxylic dianhydrides such as acid dianhydrides, adducts of hydroquinone diacetate and trimet acid anhydride, adducts of diacetyldiamine and trimet acid anhydride; 5- (2,5-dioxotetrahydrofuryl) -3-Methyl-3-cyclohexene-1,2-dicarboxylic anhydride (Dainippon Ink and Chemicals, Epicron B-4400), 1,2,3,4 Alicyclic tetracarboxylic dianhydrides such as clopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, tetrahydrofuran tetracarboxylic dianhydride; Examples thereof include aliphatic tetracarboxylic dianhydrides such as 4-butanetetracarboxylic dianhydride and 1,2,4,5-pentanetetracarboxylic dianhydride.

  By ring-opening these tetracarboxylic dianhydrides with a diol compound, (ii) at least one diol compound having at least one carboxyl group can be synthesized. However, it is also possible to synthesize the polyurethane resin of the present invention by first reacting the diol compound with (i) the diisocyanate compound and reacting this reactant with the tetracarboxylic dianhydride. Methods are also encompassed by aspects of the present invention. That is, as a method for introducing a structural unit derived from tetracarboxylic dianhydride and a diol compound into a polyurethane resin, there are the following methods.

a) A method of reacting an alcohol-terminated compound obtained by ring-opening tetracarboxylic dianhydride with a diol compound and a diisocyanate compound.
b) A method of reacting an alcohol-terminated urethane compound obtained by reacting a diisocyanate compound under an excess of a diol compound with tetracarboxylic dianhydride.

  Of the at least one diol compound having at least one carboxyl group, the compound represented by the general formula (5) is more preferable because of high solvent solubility and easy synthesis. Further, at least one diol compound having at least one carboxyl group, the polyurethane resin binder has a carboxyl group of 0.2 to 4.0 meq / g, preferably 0.3 to 3.0 meq / g, more preferably Introduced into the polyurethane resin binder in such an amount as having a range of 0.4 to 2.0 meq / g, particularly preferably 0.5 to 1.5 meq / g, most preferably 0.6 to 1.2 meq / g. . Accordingly, the content in the polyurethane resin binder having a structure derived from at least one diol compound having at least one carboxyl group is the number of carboxyl groups, what is used as the other diol component, and the acid of the polyurethane resin binder obtained. Although it is appropriately selected depending on the value, molecular weight, developer composition, pH, etc., for example, it is 5 to 45 mol%, preferably 10 to 40 mol%, more preferably 15 to 35 mol%.

(Iii) Diisocyanate compound having a crosslinkable group As the diisocyanate compound having a crosslinkable group, for example, a triisocyanate compound and 1 equivalent of a monofunctional alcohol or monofunctional amine compound having a crosslinkable group are subjected to an addition reaction. There is a product obtained.
Examples of the triisocyanate compound include those shown below, but are not limited thereto.

  Examples of the monofunctional alcohol or monofunctional amine compound having a crosslinkable group include those shown below, but are not limited thereto.

  Here, as a method for introducing a crosslinkable group into the side chain of the polyurethane resin, a method using a diisocyanate compound containing a crosslinkable group in the side chain as a raw material for producing the polyurethane resin is suitable. Examples of the diisocyanate compound that can be obtained by addition reaction of a triisocyanate compound and one equivalent of a monofunctional alcohol having a crosslinkable group or a monofunctional amine compound having a crosslinkable group in the side chain include, for example, Although the following are mentioned, it is not limited to this.

(Iv) Other diol compound As a method for introducing an unsaturated group into the side chain of the polyurethane resin, in addition to the above-described method, a diol compound containing an unsaturated group in the side chain is used as a raw material for polyurethane resin production. A method is also suitable. Such a diol compound may be a commercially available one such as trimethylolpropane monoallyl ether, a halogenated diol compound, a triol compound, an aminodiol compound, a carboxylic acid containing an unsaturated group, and an acid. It may be a compound that is easily produced by a reaction with a chloride, isocyanate, alcohol, amine, thiol, or alkyl halide compound. Specific examples of these compounds include, but are not limited to, the compounds shown below.

Still another diol compound includes an ethylene glycol compound represented by the following general formula (A ′).
HO— (CH ₂ CH ₂ O) _n —H (A ′)
(In the formula, n represents an integer of 1 or more.)

  Moreover, the random copolymer and block copolymer of ethylene oxide and propylene oxide which have a hydroxyl group at the terminal are also mentioned.

Furthermore, ethylene oxide adducts of bisphenol A (addition number of ethylene oxide 27 to 100), ethylene oxide adducts of bisphenol F (ethylene oxide addition number of 22 to 100), ethylene oxide adducts of hydrogenated bisphenol A (addition of ethylene oxide) The ethylene oxide adduct of hydrogenated bisphenol F (the number of addition of ethylene oxide is 18 or more and 100 or less) can also be used.
More specifically, the ethylene glycol compound represented by the general formula (A ′) is preferable in terms of dirtiness, an ethylene glycol compound in which n is 2 to 50 is more preferable, and an ethylene glycol compound in which n is 3 to 30 Are more preferable, and an ethylene glycol compound in which n is 4 to 10 is particularly preferable.

  Specifically, 1,2-propylene glycol, di-1,2-propylene glycol, tri-1,2-propylene glycol, tetra-1,2-propylene glycol, hexa-1,2-propylene glycol, 1, 3-propylene glycol, di-1,3-propylene glycol, tri-1,3-propylene glycol, tetra-1,3-propylene glycol, 1,3-butylene glycol, di-1,3-butylene glycol, tri- 1,3-butylene glycol, hexa-1,3-butylene glycol, polypropylene glycol having an average molecular weight of 400, polypropylene glycol having an average molecular weight of 700, polypropylene glycol having an average molecular weight of 1000, polypropylene glycol having an average molecular weight of 2000, and polypropylene having an average molecular weight of 3000 Glycol, average molecular weight 4000 polypropylene glycol, neopentyl glycol, 2-butene-1,4-diol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-bis-β-hydroxyethoxycyclohexane 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, cyclohexanedimethanol, tricyclodecane dimethanol, hydrogenated bisphenol A , Hydrogenated bisphenol F, ethylene oxide adduct of bisphenol A (addition number of ethylene oxide is 26 or less), ethylene oxide adduct of bisphenol F (addition number of ethylene oxide is 21 or less), ethylene oxide adduct of hydrogenated bisphenol A (ethyleneoxy ), Hydrogenated bisphenol F ethylene oxide adduct (ethylene oxide addition number 17 or less), bisphenol A propylene oxide adduct, bisphenol F propylene oxide adduct, hydrogenated bisphenol A propylene oxide Adduct, propylene oxide adduct of hydrogenated bisphenol F, hydroquinone dihydroxyethyl ether, p-xylylene glycol, dihydroxyethyl sulfone, bis (2-hydroxyethyl) -2,4-tolylene dicarbamate, 2,4-tolylene- Examples thereof include bis (2-hydroxyethylcarbamide), bis (2-hydroxyethyl) -m-xylylene dicarbamate, and bis (2-hydroxyethyl) isophthalate.

  Moreover, the polyether diol compound of the compound represented by Formula (A), (B), (C), (D), (E) can also be used suitably.

In formulas (A) to (E), R ⁶ represents a hydrogen atom or a methyl group. However, in the formula (A), R ⁶ represents a methyl group. X represents the following group.

  In formulas (A) to (E), a, b, c, d, e, f, and g each represent an integer of 2 or more. Preferably it is an integer of 2-100.

  Furthermore, the polyester diol compound represented by Formula (11), (12) can also be mentioned as a specific example.

In formulas (11) to (12), L ¹ , L ² and L ³ may be the same or different and each represents a divalent aliphatic or aromatic hydrocarbon group, and L ⁴ represents a divalent aliphatic carbonization. Indicates a hydrogen group. Preferably, L ¹ , L ² and L ³ each represents an alkylene group, an alkenylene group, an alkynylene group or an arylene group, and L ⁴ represents an alkylene group. In addition, L ¹ , L ² , L ³ , and L ⁴ contain other functional groups that do not react with isocyanate groups, such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group, or halogen atoms. May be. n1 and n2 are each an integer of 2 or more, preferably an integer of 2 to 100.

  Furthermore, the polycarbonate diol compound represented by Formula (13) can also be mentioned as a specific example.

In the formula (13), L ⁵ may be the same or different and each represents a divalent aliphatic or aromatic hydrocarbon group. Preferably, L ⁵ represents an alkylene group, an alkenylene group, an alkynylene group or an arylene group. In addition, other functional groups that do not react with the isocyanate group, such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group or halogen atom may be present in L ⁵ . n3 is an integer greater than or equal to 2, respectively, Preferably the integer of 2-100 is shown.

  Specific examples of the diol compound represented by the formula (11), (12) or (13) include those shown below. N in the specific examples is an integer of 2 or more.

  Furthermore, a diol compound that does not have a carboxyl group and may have another substituent that does not react with isocyanate can also be used.

Such diol compounds include those represented by the following formulas (14) and (15).
^{HO-L 6 -O-CO-} L 7 -CO-O-L 6 -OH (14)
^{HO-L 7 -CO-O-} L 6 -OH (15)

In the formulas (14) and (15), L ⁶ and L ⁷ may be the same or different, and each may have a substituent (for example, alkyl, aralkyl, aryl, alkoxy, aryloxy, halogen atom (—F, —Cl, -Br, -I), and the like, which may have a divalent aliphatic hydrocarbon group, aromatic hydrocarbon group or heterocyclic group. If necessary, L ⁶ and L ⁷ may have another functional group that does not react with an isocyanate group, for example, carbonyl, ester, urethane, amide, ureido group and the like. Note that L ⁶ and L ⁷ may form a ring.

  Specific examples of the compound represented by the formula (14) or (15) include those shown below.

  Moreover, the diol compound shown to following formula (16)-(18) can also be used conveniently.

In the formula (16), R ⁷ and R ⁸ may be the same or different and may have a substituent, preferably a cyano, nitro, halogen atom (—F, —Cl, —Br). _{, -I), - CONH 2,} -COOR, -OR, ( wherein, R represents may be the same or different from each other, alkyl groups having 1 to 10 carbon atoms, ants having 7 to 15 carbon atoms - Le group Represents an aralkyl group.) Represents an alkyl group having 1 to 10 carbon atoms which may have each group as a substituent.
Specific examples of the diol compound represented by the formula (16) include those shown below.

Examples of the formula (17) include 2-butyne-1,4-diol, and examples of the formula (18) include cis-2-butene-1,4-diol and trans-2-butene-1,4-diol. It is done.
Moreover, the diol compound shown to following formula (19), (20) can also be used conveniently.
^{HO-L 8 -NH-CO-} L 9 -CO-NH-L 8 -OH (19)
^{HO-L 9 -CO-NH-} L 8 -OH (20)

In formulas (19) and (20), L ⁸ and L ⁹ may be the same or different, and each may have a substituent (for example, alkyl, aralkyl, aryl, alkoxy, aryloxy, halogen atom (—F, —Cl, -Br, -I), and the like, which may have a divalent aliphatic hydrocarbon group, aromatic hydrocarbon group or heterocyclic group. If necessary, L ⁸ and L ⁹ may have other functional groups that do not react with isocyanate groups, such as carbonyl, ester, urethane, amide, ureido groups and the like. Note that L ⁸ and L ⁹ may form a ring.
Specific examples of the compound represented by the formula (19) or (20) include those shown below.

Furthermore, diol compounds represented by the following formulas (21) and (22) can also be suitably used.
^{HO-Ar 2 - (L 16} -Ar 3) n -OH (21)
^{HO-Ar 2 -L 16 -OH (} 22)
In formulas (21) to (22), L ¹⁶ is a divalent aliphatic hydrocarbon which may have a substituent (for example, alkyl, aralkyl, aryl, alkoxy, aryloxy and halogeno groups are preferred). Indicates a group. If necessary, L ¹⁶ may have another functional group that does not react with an isocyanate group, such as an ester, urethane, amide, or ureido group.
Ar ² and Ar ³ may be the same or different and each represents a divalent aromatic hydrocarbon group which may have a substituent, preferably an aromatic group having 6 to 15 carbon atoms. n represents an integer of 0 to 10.

Specific examples of the diol compound represented by the formula (21) or (22) include those shown below.
That is, catechol, resorcin, hydroquinone, 4-methylcatechol, 4-t-butylcatechol, 4-acetylcatechol, 3-methoxycatechol, 4-phenylcatechol, 4-methylresorcin, 4-ethylresorcin, 4-t-butyl Resorcin, 4-hexyl resorcin, 4-chlororesorcin, 4-benzyl resorcin, 4-acetyl resorcin, 4-carbomethoxy resorcin, 2-methyl resorcin, 5-methyl resorcin, t-butyl hydroquinone, 2,5-di-t -Butylhydroquinone, 2,5-di-t-amylhydroquinone, tetramethylhydroquinone, tetrachlorohydroquinone, methylcarboaminohydroquinone, methylureidohydroquinone, methylthiohydroquinone, benzonor Runene-3,6-diol, bisphenol A, bisphenol S, 3,3′-dichlorobisphenol S, 4,4′-dihydroxybenzophenone, 4,4′-dihydroxybiphenyl, 4,4′-thiodiphenol, 2, 2′-dihydroxydiphenylmethane, 3,4-bis (p-hydroxyphenyl) hexane, 1,4-bis (2- (p-hydroxyphenyl) propyl) benzene, bis (4-hydroxyphenyl) methylamine, 1,3 -Dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,5-dihydroxyanthraquinone, 2-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, 2-hydroxy-3, 5-di-t-butylbenzyl Alcohol, 4-hydroxy-3,5-di-t-butylbenzyl alcohol, 4-hydroxyphenethyl alcohol, 2-hydroxyethyl-4-hydroxybenzoate, 2-hydroxyethyl-4-hydroxyphenyl acetate, resorcin mono-2- And hydroxyethyl ether. The diol compound shown below can also be used conveniently.

(V) Other amino group-containing compounds In the specific polyurethane resin of the present invention, the amino group-containing compounds represented by the following formulas (31) and (32) are further combined and reacted with a diisocyanate compound to form a urea structure to form a polyurethane resin. It may be incorporated into the structure.

In formulas (31) and (32), R ^106A and R ^106B may be the same as or different from each other, and may be a hydrogen atom, a substituent (for example, alkoxy, halogen atom (—F, —Cl, —Br, —I). ), An ester, a carboxyl group, and the like. An alkyl group, an aralkyl group, and an aryl group that may have a hydrogen atom and a carbon number that may have a carboxyl group as a substituent. 1 to 8 alkyl, and an aryl group having 6 to 15 carbon atoms. L ¹⁷ has a substituent (for example, each group such as alkyl, aralkyl, aryl, alkoxy, aryloxy, halogen atom (—F, —Cl, —Br, —I), carboxyl group and the like is included). And a divalent aliphatic hydrocarbon group, aromatic hydrocarbon group or heterocyclic group. If necessary, L ¹⁷ may have another functional group that does not react with an isocyanate group, such as a carbonyl group, an ester group, a urethane group or an amide group. Two of R ^106A , L ¹⁷ and R ^106B may form a ring.

Specific examples of the compounds represented by the formulas (31) and (32) include those shown below.
That is, ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, dodecamethylenediamine, propane-1,2-diamine, bis (3-aminopropyl) methylamine, 1 , 3-bis (3-aminopropyl) tetramethylsiloxane, piperazine, 2,5-dimethylpiperazine, N- (2-aminoethyl) piperazine, 4-amino-2,2-6,6-tetramethylpiperidine, N , N-dimethylethylenediamine, lysine, L-cystine, isophoronediamine, and the like; o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-tolylenediamine, benzidine, o- Toluidine, o-dianisidine, 4-nitro-m-phenylenediamine, 2,5-dimethoxy-p-phenylenediamine, bis- (4-aminophenyl) sulfone, 4-carboxy-o-phenylenediamine, 3-carboxy-m -Aromatic diamine compounds such as phenylenediamine, 4,4'-diaminophenyl ether, 1,8-naphthalenediamine, etc .; 2-aminoimidazole, 3-aminotriazole, 5-amino-1H-tetrazole, 4-aminopyrazole 2-aminobenzimidazole, 2-amino-5-carboxy-triazole, 2,4-diamino-6-methyl-S-triazine, 2,6-diaminopyridine, L-histidine, DL-tryptophan, adenine, etc. Heterocyclic amine compounds; ethanolamine, N- Tylethanolamine, N-ethylethanolamine, 1-amino-2-propanol, 1-amino-3-propanol, 2-aminoethoxyethanol, 2-aminothioethoxyethanol, 2-amino-2-methyl-1-propanol P-aminophenol, m-aminophenol, o-aminophenol, 4-methyl-2-aminophenol, 2-chloro-4-aminophenol, 4-methoxy-3-aminophenol, 4-hydroxybenzylamine, 4 -Amino-1-naphthol, 4-aminosalicylic acid, 4-hydroxy-N-phenylglycine, 2-aminobenzyl alcohol, 4-aminophenethyl alcohol, 2-carboxy-5-amino-1-naphthol, L-tyrosine, etc. Such as amino alcohol or amino Lumpur compound.

  The specific polyurethane resin according to the present invention may be used alone or in combination of two or more. Moreover, 1-30 mass% is preferable, as for content of the specific polyurethane resin in a photosensitive layer, 3-20 mass% is more preferable, and 5-10 mass% is further more preferable.

-acrylic resin-
The binder polymer according to the present invention preferably contains an acrylic resin in addition to the specific polyurethane resin. In addition, the mass ratio of the specific polyurethane resin and the acrylic resin is preferably 1: 9 to 5: 5, more preferably 1: 9 to 4: 6, from the viewpoint of balance of sensitivity, printing durability, and developability. : 9 to 3: 7 is more preferable.

  As the acrylic resin, various known acrylic resins can be used. Among them, a preferable acrylic resin in the present invention is a polymer compound having a repeating unit represented by the following general formula (i). Hereinafter, the polymer compound having a repeating unit represented by formula (i) will be described in detail.

(In General Formula (i), R ²³ represents a hydrogen atom or a methyl group, and R ²⁴ is composed of one or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. B represents an oxygen atom or —NR ²² —, R ²² represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and m represents an integer of 1 to 5. )

R ²³ in the general formula (i) represents a hydrogen atom or a methyl group, and a methyl group is particularly preferable.
The linking group represented by R ²⁴ in the general formula (i) is composed of one or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. The number of atoms excluding substituents is preferably 2 to 82. Specifically, the number of atoms constituting the main skeleton of the linking group represented by R ²⁴ is preferably 1 to 30, more preferably 3 to 25, and further preferably 4 to 20. Preferably, it is 5-10. The “main skeleton of the linking group” in the present invention refers to an atom or an atomic group used only for linking B and the terminal COOH in the general formula (i), and in particular, when there are a plurality of linking paths. Refers to an atom or atomic group that constitutes a path with the least number of atoms used. Therefore, when a linking group has a ring structure, the number of atoms to be included differs depending on the linking site (for example, o-, m-, p-, etc.).

More specific examples include alkylene, substituted alkylene, arylene, substituted arylene, and the like, and a structure in which a plurality of these divalent groups are linked by an amide bond or an ester bond may be used.
Examples of the linking group having a chain structure include ethylene and propylene. A structure in which these alkylenes are linked via an ester bond can also be exemplified as a preferable example.

Among these, the linking group represented by R ²⁴ in the general formula (i) is preferably an (n + 1) -valent hydrocarbon group having an aliphatic cyclic structure having 3 to 30 carbon atoms. More specifically, a compound having an aliphatic cyclic structure such as cyclopropane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, dicyclohexyl, tercyclohexyl, norbornane and the like, which may be substituted one or more by any substituent. And (n + 1) valent hydrocarbon groups by removing (n + 1) hydrogen atoms on an arbitrary carbon atom constituting. R ²⁴ preferably has 3 to 30 carbon atoms including a substituent.

One or more arbitrary carbon atoms of the compound constituting the aliphatic cyclic structure may be replaced with a heteroatom selected from a nitrogen atom, an oxygen atom, or a sulfur atom. In terms of printing durability, R ²⁴ is a condensed polycyclic aliphatic hydrocarbon, a bridged cyclic aliphatic hydrocarbon, a spiro aliphatic hydrocarbon, an aliphatic hydrocarbon ring assembly (a plurality of rings are connected by a bond or a linking group). A (n + 1) valent hydrocarbon group having an aliphatic cyclic structure which may have a substituent of 5 to 30 carbon atoms containing two or more rings. . Also in this case, the carbon number includes the carbon atom of the substituent.

As the linking group represented by R ²⁴ , those having 5 to 10 atoms constituting the main skeleton of the linking group are particularly preferable, and are structurally a chain structure, and an ester bond in the structure. And those having a cyclic structure as described above are preferred.

R ²² when B in the general formula (i) is NR ^22- represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ²² include an alkyl group, an aryl group, an alkenyl group, and an alkynyl group.
Although a specific example is given below, it is not limited to these.

  One type of repeating unit represented by the general formula (i) may be contained in the polymer compound, or two or more types may be contained. The acrylic resin that can be used in the present invention may be composed of only the repeating unit represented by the general formula (i), but is usually used as a copolymer in combination with other copolymerization components. The total content of the repeating unit represented by the general formula (i) in the copolymer is appropriately determined depending on its structure, the design of the photosensitive layer composition, etc., but preferably 1 to 99 with respect to the total molar amount of the polymer component. It is contained in the range of mol%, more preferably 5 to 40 mol%, still more preferably 5 to 20 mol%.

  As a copolymerization component in the case of using as a copolymer, a conventionally well-known thing can be used without a restriction | limiting, if it is a monomer which can be radically polymerized. Specific examples include monomers described in “Polymer Data Handbook—Basic Edition” (Edition of Polymer Society, Bafukan, 1986). One type of such copolymerization component may be used, or two or more types may be used in combination.

  The molecular weight of the acrylic resin preferably used in the present invention is appropriately determined from the viewpoint of image formability and printing durability. The molecular weight is preferably in the range of 2,000 to 1,000,000, more preferably 5,000 to 500,000, and still more preferably 10,000 to 200,000.

―Other resins―
The binder polymer according to the present invention may contain other resins in addition to the specific polyurethane resin and acrylic resin, if necessary.
Specific examples of the other resins include acetal-modified polyvinyl alcohol resins (butyral resin and the like).
0-20 mass% is preferable, as for content of the other resin in a binder polymer, 0-15 mass% is more preferable, and 0-10 mass% is further more preferable.
Moreover, 5-90 mass% is preferable, as for content of the binder polymer in a photosensitive layer, 10-70 mass% is more preferable, and 10-60 mass% is further more preferable.

<Sensitizing dye>
The photosensitive layer of the present invention contains a sensitizing dye. For example, by adding a sensitizing dye having a maximum absorption at 300 to 450 nm, a sensitizing dye having a maximum absorption at 500 to 600 nm, and an infrared absorber having a maximum absorption at 750 to 1400 nm, each is normally used in the industry. It is possible to provide a high-sensitivity lithographic printing plate corresponding to the 405 nm violet laser, 532 nm green laser, and 803 nm IR laser.

First, a sensitizing dye having a maximum absorption in the wavelength region of 350 to 450 nm will be described.
Examples of such a sensitizing dye include merocyanine dyes, benzopyrans, coumarins, aromatic ketones, anthracenes, and the like.

  Among the sensitizing dyes having an absorption maximum in the wavelength range of 350 nm to 450 nm, a dye more preferable from the viewpoint of high sensitivity is a dye represented by the following general formula (IX).

In General Formula (IX), A represents an aromatic ring group or a heterocyclic group which may have a substituent, and X represents an oxygen atom, a sulfur atom, or N— (R ₃ ). R ₁ , R ₂ and R ₃ each independently represent a monovalent nonmetallic atomic group, and A and R ₁ and R ₂ and R ₃ are bonded to each other to form an aliphatic or aromatic ring. May be formed.

General formula (IX) will be described in more detail. R ₁ , R ₂ and R ₃ are each independently a monovalent nonmetallic atomic group, preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group Represents a substituted or unsubstituted aromatic heterocyclic residue, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a hydroxyl group, or a halogen atom.

Next, A in the general formula (IX) will be described. A represents an aromatic ring group or a heterocyclic group which may have a substituent. Specific examples of the aromatic ring or heterocyclic ring which may have a substituent include R _{1 in} formula (IX). , R ₂ and R ₃ are the same.

As specific examples of such a sensitizing dye, compounds described in paragraphs 0047 to 0053 of JP-A-2007-58170 are preferably used.

  Furthermore, sensitizing dyes represented by the following general formulas (V) to (VII) can also be used.

In formula (V), R ^{1 to} R ¹⁴ each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a cyano group, or a halogen atom. However, at least one of R ^{1 to} R ¹⁰ represents an alkoxy group having 2 or more carbon atoms.
In formula (VI), R ^{15 to} R ³² each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a cyano group, or a halogen atom. However, at least one of R ^{15 to} R ²⁴ represents an alkoxy group having 2 or more carbon atoms.

In formula (VII), R ¹ , R ² and R ³ each independently represent a halogen atom, alkyl group, aryl group, aralkyl group, —NR ⁴ R ⁵ group or —OR ⁶ group, and R ⁴ , R ⁵ And R ⁶ each independently represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and k, m and n each represents an integer of 0 to 5.

Also, there are sensitizing dyes described in JP2007-171406, JP2007-206216, JP2007-206217, JP2007-225701, JP2007-225702, JP2007-316582, and JP2007-328243. It can be preferably used.
The addition amount of the sensitizing dye having the maximum absorption at 300 to 450 nm is preferably 0.05 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, most preferably 100 parts by mass of the total solid content of the photosensitive layer. Preferably it is the range of 0.2-10 mass parts.

  Similarly, the addition amount of the sensitizing dye having the maximum absorption at 500 to 600 nm is preferably 0.05 to 30 parts by mass, more preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the total solid content of the photosensitive layer. Parts, most preferably in the range of 0.2 to 10 parts by weight.

Then, the sensitizing dye (infrared absorber) which has maximum absorption in 750-1400 nm used suitably by this invention is explained in full detail.
The sensitizing dye used here is highly sensitive to infrared laser irradiation (exposure) and is in an electronically excited state. The electron transfer, energy transfer, heat generation (photothermal conversion function), etc., associated with the electronically excited state are the photosensitive layer. It is presumed that it acts on a polymerization initiator coexisting therein to cause a chemical change in the polymerization initiator to generate a radical. In any case, the addition of a sensitizing dye having a maximum absorption at 750 to 1400 nm is particularly suitable for plate making directly drawn with an infrared laser beam having a wavelength of 750 to 1400 nm, and the conventional lithographic printing plate precursor Compared with this, high image forming properties can be exhibited.

  The infrared absorber is preferably a dye or pigment having an absorption maximum at a wavelength of 750 nm to 1400 nm.

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

In general formula (a), X ¹ represents a hydrogen atom, a halogen atom, -NPh ₂ , X ² -L ¹ or a group shown below. Here, X ² represents an oxygen atom, 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 including a hetero atom. 12 hydrocarbon groups are shown. In addition, a hetero atom here shows N, S, O, a halogen atom, and Se. X _a ^- is Z _a which will be described below ^- has the same definition as, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom.

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

Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. 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.

Z _a ⁻ represents a counter anion. However, when the cyanine dye represented by formula (a) has an anionic substituent in the structure thereof, Z _a is does not require charge neutralization ^- is not necessary. Preferred Z _a ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, from the storage stability of the photosensitive layer coating solution. Hexafluorophosphate ions and aryl sulfonate ions. In addition, the thing which does not contain a halogen ion as a counter ion is especially preferable.

Specific examples of the cyanine dye represented by formula (a) that can be suitably used include those described in paragraph numbers [0017] to [0019] of JP-A No. 2001-133969.
Further, other particularly preferable examples include specific indolenine cyanine dyes described in Japanese Patent Application Nos. 2001-6326 and 2001-237840 described above.
However, those containing no halogen ion as the counter ion are particularly preferred.

  Examples of pigments include commercially available pigment and color index (CI) manuals, “Latest Pigment Handbook” (edited by the Japan Pigment Technology Association, published in 1977), “Latest Pigment Applied Technology” (published by CMC, published in 1986), “Printing” The pigments described in "Ink Technology", published by CMC Publishing, 1984) can be used.

  Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Among these pigments, carbon black is preferable.

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

  The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm. Within this preferred particle size range, excellent dispersion stability of the pigment in the photosensitive layer can be obtained, and a uniform photosensitive layer can be obtained.

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

  These infrared absorbers may be added to the same layer as other components, or another layer may be provided and added thereto.

  From the viewpoint of uniformity in the photosensitive layer and durability of the photosensitive layer, these infrared absorbers are 0.01 to 50% by mass, preferably 0.1 to 10% by mass, based on the total solid content constituting the photosensitive layer. In the case of a dye, it is particularly preferably 0.5 to 10% by mass, and in the case of a pigment, it is particularly preferably 0.1 to 10% by mass.

<Polymerization initiator>
The photosensitive layer of the present invention contains a polymerization initiator (hereinafter also referred to as an initiator compound). The initiator compound is a compound that undergoes a chemical change through the action of electron transfer, energy transfer, heat generation, etc. caused by the electronic excitation state of the sensitizing dye, and generates at least one selected from radicals, acids, and bases. is there. Hereinafter, radicals, acids, and bases generated in this way are simply referred to as active species. When the initiator compound is not present or when only the initiator compound is used alone, practically sufficient sensitivity cannot be obtained. As one mode in which a sensitizing dye and an initiator compound are used in combination, they can be used as a single compound by an appropriate chemical method (such as linking a sensitizing dye and an initiator compound through a chemical bond). It is.

  Usually, many of these initiator compounds are considered to generate active species through the initial chemical processes represented by the following (1) to (3). (1) Reductive decomposition of the initiator compound based on the electron transfer reaction from the electronically excited state of the sensitizing dye to the initiator compound, (2) Electron transfer from the initiator compound to the electronically excited state of the sensitizing dye (3) decomposition of the initiator compound from the electronically excited state based on energy transfer from the electronically excited state of the sensitizing dye to the initiator compound. Although it is often ambiguous as to which type of (1) to (3) each individual initiator compound belongs, the sensitizing dye in the present invention is extremely in combination with any of these types of initiator compounds. Shows a high sensitizing effect.

  As the initiator compound in the present invention, those known to those skilled in the art can be used without limitation, and specifically include, for example, trihalomethyl compounds, carbonyl compounds, organic peroxides, azo compounds, azide compounds, metallocene compounds. , Hexaarylbiimidazole compounds, organic boron compounds, disulfone compounds, oxime ester compounds, onium salt compounds, and iron arene complexes. Among these, at least one selected from the group consisting of hexaarylbiimidazole compounds, onium salts, trihalomethyl compounds, and metallocene compounds is preferable, and hexaarylbiimidazole compounds are particularly preferable. Two or more of the above polymerization initiators can be used in combination as appropriate.

Examples of the hexaarylbiimidazole compounds include lophine dimers described in JP-B Nos. 45-37377 and 44-86516, such as 2,2′-bis (o-chlorophenyl) -4,4 ′, 5. , 5'-tetraphenylbiimidazole, 2,2'-bis (o-bromophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o, p-dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra (m-methoxyphenyl) biimidazole, 2, 2'-bis (o, o'-dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-nitrophenyl) -4,4', 5,5 ' -Te Raphenylbiimidazole, 2,2'-bis (o-methylphenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-trifluorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole and the like.
The hexaarylbiimidazole compound is particularly preferably used in combination with a sensitizing dye having a maximum absorption at 300 to 450 nm.

  The onium salt suitably used in the present invention (in the present invention, functions as an ionic polymerization initiator, not as an acid generator) is represented by the following general formulas (RI-I) to (RI-III). Onium salt.

In the formula (RI-I), Ar ₁₁ represents an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents, and preferred substituents include an alkyl group having 1 to 12 carbon atoms and a carbon number. 1-12 alkenyl group, C1-C12 alkynyl group, C1-C12 aryl group, C1-C12 alkoxy group, C1-C12 aryloxy group, halogen atom, C1-C1 12 alkylamino groups, C1-C12 dialkylamino groups, C1-C12 alkylamide groups or arylamide groups, carbonyl groups, carboxyl groups, cyano groups, sulfonyl groups, C1-C12 thioalkyl groups And a thioaryl group having 1 to 12 carbon atoms. Z ₁₁ ⁻ represents a monovalent anion, and specific examples include halogen ions, perchlorate ions, haloborate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Of these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion and sulfinate ion are preferable from the viewpoint of stability.

In the formula (RI-II), Ar ₂₁ and Ar ₂₂ each independently represent an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents, and preferred substituents include 1 to 1 carbon atoms. 12 alkyl groups, an alkenyl group having 1 to 12 carbon atoms, an alkynyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 1 to 12 carbon atoms, Halogen atom, C1-C12 alkylamino group, C1-C12 dialkylamino group, C1-C12 alkylamide group or arylamide group, carbonyl group, carboxyl group, cyano group, sulfonyl group, carbon Examples thereof include a thioalkyl group having 1 to 12 carbon atoms and a thioaryl group having 1 to 12 carbon atoms. Z ₂₁ ⁻ represents a monovalent anion. Specific examples include halogen ions, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Among them, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, and carboxylate ion are preferable in terms of stability and reactivity.

In the formula (RI-III), R ₃₁ , R ₃₂ and R ₃₃ are each independently an aryl group, alkyl group, alkenyl group or alkynyl having 20 or less carbon atoms, which may have 1 to 6 substituents. Represents a group. Among them, an aryl group is preferable from the viewpoint of reactivity and stability. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 1 to 12 carbon atoms, an alkynyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, Aryloxy group having 1 to 12 carbon atoms, halogen atom, alkylamino group having 1 to 12 carbon atoms, dialkylamino group having 1 to 12 carbon atoms, alkylamide group or arylamide group having 1 to 12 carbon atoms, carbonyl group, carboxyl Group, a cyano group, a sulfonyl group, a thioalkyl group having 1 to 12 carbon atoms, and a thioaryl group having 1 to 12 carbon atoms. Z ₃₁ ^- represents a monovalent anion. Specific examples include halogen ions, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Among these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, and carboxylate ion are preferable from the viewpoints of stability and reactivity. More preferred are the carboxylate ions described in JP-A No. 2001-343742, and particularly preferred are the carboxylate ions described in JP-A No. 2002-148790.
The onium salt is particularly preferably used in combination with an infrared absorber having a maximum absorption at 750 to 1400 nm.

  Examples of other polymerization initiators include JP 2007-171406, JP 2007-206216, JP 2007-206217, JP 2007-225701, JP 2007-225702, JP 2007-316582, and JP 2007-328243. The polymerization initiators described can be preferably used.

The polymerization initiator in the present invention is preferably used alone or in combination of two or more.
The amount of the polymerization initiator used in the photosensitive layer in the present invention is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, based on the total solid content of the photosensitive layer. More preferably, it is 1.0 mass%-10 mass%.

<Polymerizable compound>
The polymerizable compound used for the photosensitive layer in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and is a compound having at least one terminal ethylenically unsaturated bond, preferably two or more. To be elected. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. These have chemical forms such as monomers, prepolymers, i.e. dimers, trimers and oligomers, or copolymers thereof, or mixtures thereof.

  Examples of monomers include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof, preferably unsaturated carboxylic acids. An ester of an acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyamine compound are used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxyl group, amino group or mercapto group with a monofunctional or polyfunctional isocyanate or epoxy, and monofunctional or polyfunctional A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an epoxy group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, a halogen group or In addition, a substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a tosyloxy group and a monofunctional or polyfunctional alcohol, amine or thiol is also suitable. As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.

  Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol. Diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate , Tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, isocyanuric acid ethylene oxide (EO) Examples include modified triacrylates and polyester acrylate oligomers.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3-methacryloxy- 2-hydroxypro ) Phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

  Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate. Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate. Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate. Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Examples of other esters include aliphatic alcohol esters described in JP-B-51-47334 and JP-A-57-196231, JP-A-59-5240, JP-A-59- Those having an aromatic skeleton described in JP-A No. 5241 and JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used.
Furthermore, the ester monomers described above can also be used as a mixture.

  Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like. Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B No. 54-21726.

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

_{CH 2 = C (R 4)} COOCH 2 CH (R 5) OH (Z)
(However, R ₄ and R ₅ represent H or CH _3. )

  Also, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-B-58-49860, JP-B-56- Urethane compounds having an ethylene oxide skeleton described in Japanese Patent No. 17654, Japanese Patent Publication No. 62-39417, and Japanese Patent Publication No. 62-39418 are also suitable. Furthermore, addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238 are used. Depending on the case, it is possible to obtain a photopolymerizable composition excellent in the photosensitive speed.

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

About these polymerizable compounds, the details of usage such as the structure, single use or combination, addition amount and the like can be arbitrarily set according to the performance design of the final lithographic printing plate precursor. For example, it is selected from the following viewpoints.
From the viewpoint of sensitivity, a structure having a large unsaturated group content per molecule is preferable, and in many cases, a bifunctional or higher functionality is preferable. Further, in order to increase the strength of the image area, that is, the cured film, those having three or more functionalities are preferable. A method of adjusting both sensitivity and strength by using a compound) is also effective.

  In addition, the compatibility and dispersibility with other components in the photosensitive layer (for example, binder polymer, polymerization initiator, colorant, etc.), the selection and use method of the polymerizable compound is an important factor. In some cases, the compatibility can be improved by using a low-purity compound or by using two or more kinds in combination. In addition, a specific structure may be selected for the purpose of improving adhesion to a support or a protective layer described later. In addition, the usage of the polymerizable compound can be arbitrarily selected from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging, refractive index change, surface adhesiveness, etc. The layer construction and coating method such as undercoating and overcoating can be considered.

  The polymerizable compound is preferably used in the range of 5 to 75% by mass, more preferably 25 to 70% by mass, and particularly preferably 30 to 60% by mass with respect to the total solid content of the photosensitive layer.

<Colorant>
The photosensitive layer according to the present invention preferably contains a colorant for the purpose of coloring, and among the colorants, it preferably contains a pigment.
Examples of pigments include black pigments, yellow pigments, magenta pigments, cyan pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded pigments. Can be mentioned. More specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, disazo condensed pigments, disazo pigments, phthalocyanine pigments, anthraquinone pigments, anthanthrone pigments, aminoanthraquinone pigments, diketopyrrolo Pyrrole pigments, perylene and perinone pigments, thioindigo pigments, indanthrone pigments, triarylcarbonium pigments, quinacridone pigments, quinacridone quinone pigments, dioxazine pigments, isoindoline pigments, isoindolinone pigments, Isoviolanthrone pigments, pyranthrone pigments, quinophthalone pigments, benzimidazolone pigments, thioindigo pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon bras Click, and the like.
Among the pigments, organic pigments are preferable, specifically, phthalocyanine pigments, azo pigments, dioxazine pigments, quinacrine pigments, and the like are more preferable, and phthalocyanine pigments are more preferable.

The pigment of the present invention is used for imparting visibility (plate inspection) to an original (character / picture) of a lithographic printing plate after exposure / development processing and before printing. In order to impart visibility, pigments that absorb light in a wavelength region of 500 nm or more, that is, magenta, red, cyan, blue, and green pigments are preferably used. On the contrary, for example, yellow that absorbs light only in a wavelength region of 500 nm or less is not suitable. The phthalocyanine pigment absorbs light in a wavelength region of 500 nm or more, and is suitable for imparting visibility, such as blue, green, dioxazine pigment, violet, diketopyrrolopyrrole pigment, red, and quinacridone pigment, magenta.
Examples of the method for containing the organic pigment in the photosensitive layer include a method in which an organic pigment dispersion in which an organic pigment is dispersed in a dispersion medium is added to the photosensitive layer coating solution.
The content of the organic pigment contained in the photosensitive layer is preferably 0.5% by mass to 15% by mass, more preferably 0.8% by mass to 10% by mass with respect to the total solid content of the photosensitive layer. 0 mass%-10 mass% are further more preferable.

<Other photosensitive layer components>
The photosensitive layer of the present invention can further contain various additives as required. Additives include surfactants for promoting developability and improving the surface of the coating, hydrophilic polymers for improving developability and dispersion stability of microcapsules, and visual and non-image areas visible A coloring agent and a print-out agent, a polymerization inhibitor for preventing unnecessary thermal polymerization of radically polymerizable compounds during production or storage of the photosensitive layer, a higher fat derivative for preventing polymerization inhibition by oxygen, Add inorganic fine particles to improve the strength of the cured film in the image area, hydrophilic low molecular weight compounds to improve developability, co-sensitizers and chain transfer agents to improve sensitivity, plasticizers to improve plasticity, etc. be able to.

  Any of these compounds can be used, for example, JP 2007-171406, JP 2007-206216, JP 2007-206217, JP 2007-225701, JP 2007-225702, JP 2007-316582. The compounds described in JP-A-2007-328243 can be used.

―Chain transfer agent―
As the compound that acts as a chain transfer agent, for example, a compound group having SH, PH, SiH, GeH in the molecule is used. These can donate hydrogen to low-activity radical species to generate radicals, or can be oxidized and then deprotonated to generate radicals.

  In the photosensitive layer of the present invention, in particular, a thiol compound (for example, 2-mercaptobenzimidazoles, 2-mercaptobenzthiazoles, 2-mercaptobenzoxazoles, 3-mercaptotriazoles, 5-mercaptotetrazoles, etc.) Can be preferably used as a chain transfer agent.

  Especially, the thiol compound represented by the following general formula (IV) is used especially suitably. By using this thiol compound as a chain transfer agent, the problem of odor and sensitivity reduction due to evaporation from the photosensitive layer and diffusion to other layers are avoided, and it has excellent storage stability and high sensitivity and high printing durability. A lithographic printing plate precursor is obtained.

  In general formula (IV), R represents an alkyl group which may have a substituent or an aryl group which may have a substituent, and A represents a 5-membered ring having a carbon atom together with an N = CN moiety or It represents an atomic group that forms a 6-membered heterocycle, and A may further have a substituent.

<Formation of photosensitive layer>
The photosensitive layer of the present invention is formed by preparing or applying a coating solution by dispersing or dissolving the necessary components described above in a solvent. Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, the present invention is not limited to this. These solvents are used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by mass.
The photosensitive layer of the present invention can be formed by preparing a plurality of coating solutions in which the same or different components are dispersed or dissolved in the same or different solvents, and repeatedly applying and drying a plurality of times.

Moreover, although the photosensitive layer coating amount (solid content) on the support obtained after coating and drying varies depending on the application, it is generally preferably 0.3 to 3.0 g / m ² . Within this range, good sensitivity and good film properties of the photosensitive layer can be obtained.
Various methods can be used as a coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

[Protective layer]
In the lithographic printing plate precursor according to the invention, a protective layer (oxygen blocking layer) is preferably provided on the photosensitive layer in order to block diffusion and penetration of oxygen that hinders the polymerization reaction during exposure. The protective layer used in the present invention may be a single layer or a multilayer structure. The protective layer used in the present invention preferably has an oxygen permeability A at 25 ° C. and 1 atm of 1.0 ≦ A ≦ 20 (mL / m ² · day). If the oxygen permeability A is less than 1.0 (mL / m ² · day) and extremely low, unnecessary polymerization reaction occurs during production and raw storage, and unnecessary fogging and image streaking occur during image exposure. The problem that fatness arises arises. On the contrary, when the oxygen permeability A exceeds 20 (mL / m ² · day) and is too high, the sensitivity is lowered. The oxygen permeability A is more preferably in the range of 1.5 ≦ A ≦ 12 (mL / m ² · day), more preferably 2.0 ≦ A ≦ 10.0 (mL / m ² · day). In addition to the oxygen permeability described above, the properties desired for the protective layer further do not substantially inhibit the transmission of light used for exposure, have excellent adhesion to the photosensitive layer, and are easy in the development process after exposure. It is desirable that it can be removed. The device concerning such a protective layer has been conventionally made, and is described in detail in US Pat. No. 3,458,311 and JP-B-55-49729.

  As a material that can be used for the protective layer, for example, a water-soluble polymer compound having relatively excellent crystallinity is preferably used. Specifically, polyvinyl alcohol, vinyl alcohol / vinyl phthalate copolymer, vinyl acetate / vinyl are used. Examples include water-soluble polymers such as alcohol / vinyl phthalate copolymer, vinyl acetate / crotonic acid copolymer, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, polyacrylic acid, polyacrylamide, etc. Or they can be mixed. Of these, the use of polyvinyl alcohol as the main component gives the best results in terms of basic properties such as oxygen barrier properties and development removability.

  The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether, and an acetal as long as it contains an unsubstituted vinyl alcohol unit for having necessary oxygen barrier properties and water solubility. Similarly, some of them may have other copolymer components. Specific examples of polyvinyl alcohol include those that are hydrolyzed by 71 to 100 mol% and have a polymerization repeating unit in the range of 300 to 2400. Specifically, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA- 420, PVA-613, L-8 and the like, and these can be used alone or in combination. In a preferred embodiment, the content of polyvinyl alcohol in the protective layer is 20 to 95% by mass, and more preferably 30 to 90% by mass.

  Moreover, well-known modified polyvinyl alcohol can also be used preferably. For example, various hydrophilic modification sites such as anion modification sites modified with anions such as carboxyl groups and sulfo groups, cation modification sites modified with cations such as amino groups and ammonium groups, silanol modification sites, and thiol modification sites are randomly selected. Polyvinyl alcohol having various degrees of polymerization, the anion-modified site, the cation-modified site, the silanol-modified site, the thiol-modified site, the alkoxyl-modified site, the sulfide-modified site, and the ester modification of vinyl alcohol and various organic acids. Examples thereof include polyvinyl alcohol having various polymerization degrees having various modified sites such as a site, an ester-modified site of the anion-modified site and alcohols, an epoxy-modified site, and the like.

  As a component used by mixing with polyvinyl alcohol, polyvinyl pyrrolidone or a modified product thereof is preferable from the viewpoint of oxygen barrier properties and development removability, and the content in the protective layer is 3.5 to 80% by mass, preferably 10 to 60%. It is 15 mass%, More preferably, it is 15-30 mass%.

  Components of the protective layer (selection of PVA, use of additives), coating amount, and the like are selected in consideration of fogging, adhesion, and scratch resistance in addition to oxygen barrier properties and development removability. In general, the higher the hydrolysis rate of the PVA used (the higher the content of the unsubstituted vinyl alcohol unit in the protective layer), the higher the film thickness, the higher the oxygen barrier property and the more advantageous in terms of sensitivity. The molecular weight of the (co) polymer such as polyvinyl alcohol (PVA) can be in the range of 2000 to 10 million, preferably in the range of 20,000 to 3 million.

  As another composition of the protective layer, glycerin, dipropylene glycol and the like can be added in an amount corresponding to several mass% with respect to the (co) polymer to provide flexibility. Anionic surfactants such as sodium acid salts; amphoteric surfactants such as alkylaminocarboxylates and alkylaminodicarboxylates; nonionic surfactants such as polyoxyethylene alkylphenyl ethers to the (co) polymer Mass% can be added.

  In addition, adhesion to the image area and scratch resistance are extremely important in handling the plate. That is, when a hydrophilic layer made of a water-soluble polymer is laminated on an oleophilic photosensitive layer, film peeling due to insufficient adhesion tends to occur, and the peeled part causes defects such as poor film hardening due to inhibition of oxygen polymerization. On the other hand, various proposals have been made to improve the adhesion between these two layers. For example, in U.S. Patent Application No. 292,501 and U.S. Patent Application No. 44,563, an acrylic emulsion or a water-insoluble vinyl pyrrolidone-vinyl acetate copolymer is contained in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesiveness can be obtained by mixing 20 to 60% by mass and laminating on a photosensitive layer. Any of these known techniques can be applied to the protective layer in the present invention. Such a coating method for the protective layer is described in detail in, for example, US Pat. No. 3,458,311 and Japanese Patent Publication No. 55-49729.

Furthermore, the protective layer in the lithographic printing plate precursor according to the invention preferably contains an inorganic stratiform compound for the purpose of improving oxygen barrier properties and photosensitive layer surface protection.
Here, the inorganic layered compound is a particle having a thin flat plate shape, for example, the following general formula A (B, C) ₂ -5D ₄ O ₁₀ (OH, F, O) _2.
[However, A is any one of K, Na, and Ca, B and C are any of Fe (II), Fe (III), Mn, Al, Mg, and V, and D is Si or Al. And mica groups such as natural mica and synthetic mica, talc, teniolite, montmorillonite, saponite, hectorite, zirconium phosphate and the like represented by the formula 3MgO · 4SiO · H ₂ O.

In the present invention, among the inorganic layered compounds described above, fluorine-based swellable synthetic mica that is a synthetic inorganic layered compound is particularly useful.
The aspect ratio of the inorganic layered compound of the present invention is preferably 20 or more, more preferably 100 or more, and particularly preferably 200 or more. The aspect ratio is the ratio of the thickness to the major axis of the particle, and can be measured, for example, from a projected view of the particle by a micrograph. The larger the aspect ratio, the greater the effect that can be obtained.

  As for the particle diameter of the inorganic stratiform compound used in the present invention, the average major axis is 0.3 to 20 μm, preferably 0.5 to 10 μm, particularly preferably 1 to 5 μm. The average thickness of the particles is 0.1 μm or less, preferably 0.05 μm or less, particularly preferably 0.01 μm or less. For example, among inorganic layered compounds, the size of the swellable synthetic mica that is a representative compound is about 1 to 50 nm in thickness and about 1 to 20 μm in surface size.

  When the inorganic layered compound particles having such a large aspect ratio are contained in the protective layer, the coating film strength is improved, and the permeation of oxygen and moisture can be effectively prevented. Deterioration is prevented, and even when stored for a long time under high-humidity conditions, the storage stability of the planographic printing plate precursor does not deteriorate due to changes in humidity, and the storage stability is excellent.

As a preferable embodiment of the protective layer having a multilayer structure, a protective layer containing an inorganic layered compound is provided as a lower protective layer in the vicinity of the photosensitive layer, and a protective layer containing a filler on the surface thereof is used as an upper protective layer. The aspect which laminates | stacks sequentially is mentioned.
By providing a protective layer having such a laminated structure, the uppermost protective layer has the excellent oxygen barrier properties and compatibility with the lower protective layer while fully utilizing the advantages of scratch resistance and adhesion resistance due to the filler. Thus, it is possible to effectively prevent image defects due to both the generation of scratches and undesired oxygen permeation.

  It is preferable that content of the inorganic stratiform compound in a protective layer is 5/1-1/100 by mass ratio with respect to the quantity of the binder used for a protective layer. Even when a plurality of types of inorganic layered compounds are used in combination, the total amount of these inorganic layered compounds is preferably the above-described mass ratio.

  The dispersion method of the inorganic stratiform compound used for the protective layer is disclosed in JP 2007-171406, JP 2007-206216, JP 2007-206217, JP 2007-225701, JP 2007-225702, JP 2007-316582, JP The method described in 2007-328243 etc. is used.

  The coating amount of the protective layer is preferably in the range of 0.05 to 10 g / m 2 in terms of the coating amount after drying. When the inorganic layered compound is contained, it is 0.1 to 0.5 g / m 2. In the case where the inorganic layered compound is not contained, the range of 0.5 to 5 g / m 2 is further preferable.

[Support]
The support used in the lithographic printing plate precursor according to the invention is not particularly limited as long as it is a dimensionally stable plate-like hydrophilic support. 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.), and paper or plastic films on which the above-mentioned metals are laminated or deposited. Preferable supports include a polyester film and an aluminum plate. Among these, an aluminum plate that has good dimensional stability and is relatively inexpensive is preferable.

  The aluminum plate is a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of different elements, or a plastic laminated on a thin film of aluminum or an aluminum alloy. 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 preferably 10% by mass or less. In the present invention, a pure aluminum plate is preferable, but completely pure aluminum is difficult to manufacture in terms of refining technology, and therefore may contain a slightly different element. The composition of the aluminum plate is not specified, and a publicly known material can be used as appropriate.

  The thickness of the support is preferably from 0.1 to 0.6 mm, more preferably from 0.15 to 0.4 mm, and even more preferably from 0.2 to 0.3 mm.

  Prior to using the aluminum plate, it is preferable to perform a surface treatment such as roughening treatment or anodizing treatment. By the surface treatment, it becomes easy to improve hydrophilicity and secure adhesion between the photosensitive layer and the support. Prior to the roughening treatment of the aluminum plate, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution or the like 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, mechanical surface roughening treatment, electrochemical surface roughening treatment (surface roughening treatment for dissolving the surface electrochemically), chemical treatment, etc. Surface roughening treatment (roughening treatment that chemically selectively dissolves the surface).
As a method for the mechanical surface roughening treatment, 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.
Examples of the electrochemical surface roughening treatment include a method in which an alternating current or a direct current is used in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Another example is a method using a mixed acid as described in JP-A-54-63902.

  The surface-roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide, sodium hydroxide or the like, if necessary, further neutralized, and if desired, wear resistant. In order to increase the anodic oxidation treatment.

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, hydrochloric 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 conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be specified in general. In general, however, an electrolyte concentration of 1 to 80% by mass solution, a liquid temperature of 5 to 70 ° C., a current density of 5 to 60 A / dm ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes are preferable. The amount of the anodized film formed is preferably from 1.0 to 5.0 g / ^{m 2,} and more preferably 1.5 to 4.0 g / ^{m 2.} Within this range, good printing durability and good scratch resistance of the non-image area of the lithographic printing plate can be obtained.

  As the support used in the present invention, the substrate having the above-mentioned surface treatment and having an anodized film may be used as it is, but for further improvement in adhesion to the upper layer, hydrophilicity, resistance to contamination, heat insulation and the like. If necessary, it contains a micropore enlargement treatment, a micropore sealing treatment, and a hydrophilic compound described in Japanese Patent Application Laid-Open Nos. 2001-253181 and 2001-322365. A surface hydrophilization treatment immersed in an aqueous solution can be selected as appropriate. Of course, these enlargement processing and sealing processing are not limited to those described above, and any conventionally known method can be performed.

Sealing treatment includes vapor sealing, single treatment with zirconic fluoride, treatment with an aqueous solution containing an inorganic fluorine compound such as treatment with sodium fluoride, vapor sealing with addition of lithium chloride, sealing with hot water. Hole processing is also possible.
Of these, sealing treatment with an aqueous solution containing an inorganic fluorine compound, sealing treatment with water vapor, and sealing treatment with hot water are preferable.

The hydrophilization treatment is described in the specifications of US Pat. Nos. 2,714,066, 3,181,461, 3,280,734, and 3,902,734. There are such alkali metal silicate methods. In this method, the support is immersed in an aqueous solution such as sodium silicate or electrolytically treated.
In addition, the treatment with potassium zirconate fluoride described in JP-B 36-22063, U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689, And a method of treating with polyvinylphosphonic acid as described in the specification of No. 272.

When using a support with insufficient surface hydrophilicity such as a polyester film as the support of the present invention, it is desirable to apply a hydrophilic layer to make the surface hydrophilic.
As the hydrophilic layer, at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony, and a transition metal described in JP-A-2001-199175 A hydrophilic layer obtained by coating a coating solution containing a colloid of oxide or hydroxide, or an organic hydrophilic polymer obtained by crosslinking or pseudo-crosslinking an organic hydrophilic polymer described in JP-A No. 2002-79772 A hydrophilic layer having a hydrophilic matrix, a hydrophilic layer having an inorganic hydrophilic matrix obtained by sol-gel conversion comprising hydrolysis, condensation reaction of polyalkoxysilane, titanate, zirconate or aluminate, or a metal oxide A hydrophilic layer made of an inorganic thin film having a surface is preferred. Arbitrariness. Among these, a hydrophilic layer formed by applying a coating solution containing a silicon oxide or hydroxide colloid is preferable.

  Moreover, when using a polyester film etc. as a support body of this invention, it is preferable to provide an antistatic layer in the hydrophilic layer side of a support body, the opposite side, or both sides. In the case where the antistatic layer is provided between the support and the hydrophilic layer, it also contributes to improving the adhesion with the hydrophilic layer. As the antistatic layer, a polymer layer in which metal oxide fine particles or a matting agent are dispersed as described in JP-A-2002-79772 can be used.

The support preferably has a center line average roughness of 0.10 to 1.2 μm. Within this range, good adhesion to the photosensitive layer, good printing durability and good stain resistance can be obtained.
The color density of the support is preferably 0.15 to 0.65 as the reflection density value. Within this range, good image formability by preventing halation during image exposure and good plate inspection after development can be obtained.

[Undercoat layer]
In the lithographic printing plate precursor according to the invention, it is preferable to provide an undercoat layer of a compound containing a polymerizable group on a support. When an undercoat layer is used, the photosensitive layer is provided on the undercoat layer. The undercoat layer reinforces the adhesion between the support and the photosensitive layer in the exposed area, and easily peels the photosensitive layer from the support in the unexposed area, thereby improving the developability.
As the undercoat layer, specifically, a silane coupling agent having an addition-polymerizable ethylenic double bond reactive group described in JP-A-10-282679, JP-A-2-304441. The phosphorus compound etc. which have the ethylenic double bond reactive group of description are mentioned suitably. Particularly preferable compounds include compounds having a polymerizable group such as a methacryl group or an allyl group and a support adsorbing group such as a sulfonic acid group, a phosphoric acid group, or a phosphoric acid ester. A compound having a hydrophilicity-imparting group such as an ethylene oxide group in addition to the polymerizable group and the support-adsorbing group can also be exemplified as a suitable compound.
The coating amount (solid content) of the undercoat layer is preferably from 0.1 to 100 mg / m ² , and more preferably from ¹ to 30 mg / m ² .

[Back coat layer]
After the surface treatment is performed on the support or after the undercoat layer is formed, a back coat can be provided on the back surface of the support, if necessary.
Examples of the back coat include hydrolysis and polycondensation of organic polymer compounds described in JP-A-5-45885, organometallic compounds or inorganic metal compounds described in JP-A-6-35174. A coating layer made of a metal oxide obtained in this manner is preferred. Of these, the use of silicon alkoxy compounds such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , Si (OC ₄ H ₉ ) _4, etc. is inexpensive. It is preferable in terms of easy availability.

[Plate making of lithographic printing plate precursor]
In order to make a lithographic printing plate precursor according to the present invention, at least exposure and development processes are performed.
As a light source for exposing the negative planographic printing plate precursor of the present invention, a known light source can be used without limitation. The desirable wavelength of the light source is 300 nm to 1200 nm. Specifically, it is preferable to use various lasers as the light source. Among them, an infrared laser having a wavelength of 780 nm to 1200 nm and a violet light laser having a wavelength of 350 nm to 450 nm are preferably used. .
The exposure mechanism may be any of an internal drum system, an external drum system, a flat bed system, and the like.

  In addition, as other exposure beams for the lithographic printing plate precursor of the present invention, ultra-high pressure, high pressure, medium pressure, low pressure mercury lamps, chemical lamps, carbon arc lamps, xenon lamps, metal halide lamps, various visible and ultraviolet laser lamps Fluorescent lamps, tungsten lamps, sunlight, etc. can also be used.

The lithographic printing plate precursor according to the invention is developed after being exposed. In such development processing, distilled water, an alkaline aqueous solution having a pH of 14 or less, or washing water, a surfactant and the like described in JP-A Nos. 54-8002, 55-11545, and 59-58431 are contained. Rinsing liquid, desensitizing liquid containing gum arabic or starch derivatives can be used.
As the developer, an alkaline aqueous solution having a pH of 14 or less is particularly preferable, and an alkaline aqueous solution having a pH of 8 to 12 containing an anionic surfactant is more preferably used. For example, tribasic sodium phosphate, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, ammonium, sodium borate, Examples include inorganic alkaline agents such as potassium, ammonium, sodium hydroxide, ammonium, potassium and lithium. In addition, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are also used. These alkali agents are used alone or in combination of two or more.

In the development processing of the lithographic printing plate precursor according to the invention, 1 to 20% by mass of an anionic surfactant is added to the developer, and more preferably 3 to 10% by mass. If the amount is too small, the developability deteriorates. If the amount is too large, the strength such as the abrasion resistance of the image deteriorates.
Examples of the anionic surfactant include sodium salt of lauryl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, sodium salt of octyl alcohol sulfate, such as sodium salt of isopropyl naphthalene sulfonic acid, sodium salt of isobutyl naphthalene sulfonic acid, polyoxy Higher carbon number such as sodium salt of ethylene glycol mononaphthyl ether sulfate ester, sodium salt of dodecylbenzene sulfonic acid, alkylaryl sulfonate such as sodium salt of metanitrobenzene sulfonic acid, secondary sodium alkyl sulfate, etc. Aliphatic alcohol phosphates such as alcohol sulfates, sodium salts of cetyl alcohol phosphates, eg C _{17 H 33 CON (CH 3)} CH 2 CH 2 SO 3 sulfonates of alkylamides such as Na, for example, sodium sulfosuccinate dioctyl ester, sulfonate of dibasic aliphatic esters such as sodium sulfosuccinate dihexyl ester Salts are included.

If necessary, an organic solvent such as benzyl alcohol mixed with water may be added to the developer. As the organic solvent, those having a solubility in water of about 10% by mass or less are suitable, and preferably selected from those having 5% by mass or less. For example, 1-phenylethanol, 2-phenylethanol, 3-phenylpropanol, 1,4-phenylbutanol, 2,2-phenylbutanol, 1,2-phenoxyethanol, 2-benzyloxyethanol, o-methoxybenzyl alcohol, m -Methoxybenzyl alcohol, p-methoxybenzyl alcohol, benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 4-methylcyclohexanol, 3-methylcyclohexanol and the like can be mentioned.
The content of the organic solvent is preferably 1 to 5% by mass with respect to the total mass of the developer during use. The amount used is closely related to the amount of surfactant used, and it is preferable to increase the amount of anionic surfactant as the amount of organic solvent increases. This is because when the amount of the organic solvent is large and the amount of the anionic surfactant is small, the organic solvent is not dissolved, so that it is impossible to expect good developability.

Furthermore, additives such as an antifoaming agent and a hard water softening agent can be further contained as necessary. Examples of the hard water softener include Na ₂ P ₂ O ₇ , Na ₅ P ₃ O ₃ , Na ₃ P ₃ O ₉ , Na ₂ O ₄ P (NaO ₃ P) PO ₃ Na ₂ , and Calgon (sodium polymetaphosphate). Such as polyphosphates, aminopolycarboxylic acids (eg, ethylenediaminetetraacetic acid, its potassium salt, its sodium salt; diethylenetriaminepentaacetic acid, its potassium salt, its sodium salt; triethylenetetraminehexaacetic acid, its potassium salt, its sodium salt Hydroxyethylethylenediaminetriacetic acid, its potassium salt, its sodium salt; nitrilotriacetic acid, its potassium salt, its sodium salt; 1,2-diaminocyclohexanetetraacetic acid, its potassium salt, its sodium salt; 1,3-diamino-2 -Propanol tetraacetic acid , Its potassium salt, its sodium salt), other polycarboxylic acids (for example, 2-phosphonobutanetricarboxylic acid-1,2,4, its potassium salt, its sodium salt; 2 monophosphonobutanone tricarboxylic acid-2, 3,4, its potassium salt, its sodium salt, etc.), organic phosphonic acids (eg, 1-phosphonoethanetricarboxylic acid-1,2,2, its potassium salt, its sodium salt; 1-hydroxyethane-1,1 -Diphosphonic acid, its potassium salt, its sodium salt; aminotri (methylenephosphonic acid), its potassium salt, its sodium salt, etc.).
The optimum amount of such a hard water softener varies depending on the hardness of the hard water used and the amount used, but is generally 0.01 to 5% by weight, more preferably in the developer at the time of use. It is made to contain in 0.01-0.5 mass%.

  Further, when the lithographic printing plate precursor of the present invention is developed using an automatic developing machine, the developing solution becomes fatigued according to the processing amount, so that the replenishing solution or a fresh developing solution is used to increase the processing capacity. It may be recovered. In this case, it is preferable to replenish by the method described in US Pat. No. 4,882,246. Developers described in JP-A-50-26601, 58-54341, JP-B-56-39464, 56-42860, and 57-7427 are also preferable.

  The lithographic printing plate precursor thus developed is subjected to washing water, surface activity as described in JP-A Nos. 54-8002, 55-11545, 59-58431, and the like. It may be post-treated with a rinsing liquid containing an agent, a desensitizing liquid containing gum arabic, starch derivatives, and the like. These treatments can be used in various combinations for the post-treatment of the lithographic printing plate precursor according to the invention.

As the plate-making process of the lithographic printing plate precursor according to the invention, the entire surface may be heated before exposure, during exposure, and between exposure and development, if necessary. By such heating, the image forming reaction in the photosensitive layer is promoted, and advantages such as improvement in sensitivity and printing durability and stabilization of sensitivity may occur. Further, for the purpose of improving the image strength and printing durability, it is also effective to subject the developed image to full post heating or full exposure.
Usually, heating before development is preferably performed under mild conditions of 150 ° C. or less from the viewpoint of occurrence of an undesired curing reaction. Also, very strong conditions can be used for heating after development. Usually, the heating temperature is in the range of 200 to 500 ° C. from the viewpoint of image strengthening action and thermal decomposition of the image area.

The planographic printing plate obtained by the above processing is loaded on an offset printing machine and used for printing a large number of sheets.
The stain resistance of the lithographic printing plate subjected to printing can be removed by a plate cleaner. As plate cleaners used for removing stain resistance on printing plates, conventionally known plate cleaners for PS plates are used. For example, CL-1, CL-2, CP, CN-4, CN CG-1, PC-1, SR, IC (manufactured by Fuji Photo Film Co., Ltd.) and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.

[Synthesis of polyurethane resin]
<Synthesis Example 1: Polyurethane resin (P-1)>
"Polyurethane resin (P-1)" which is a specific polyurethane resin according to the present invention was synthesized as follows.
In a 500 ml three-necked round bottom flask equipped with a condenser and a stirrer, diphenylmethane diisocyanate (100.10 g, Wako Pure Chemical Industries, Ltd.), hexamethylene diisocyanate (16.82 g, manufactured by Wako Pure Chemical Industries, Ltd.), the following compound 1 ( 41.32 g), polypropylene glycol having an average molecular weight of 1000 (100.00 g, Wako Pure Chemical Industries, Ltd.), the following compound 2 (21.14 g), the following compound 3 (1.18 g), N, N-dimethylacetamide (800 g) , Wako Pure Chemical Industries, Ltd.) and di-n-butyltin dilaurate (5 drops, manufactured by Tokyo Chemical Industry Co., Ltd.) were heated at 100 ° C. for 8 hours. Then, it diluted with methanol (100 ml) and N, N-dimethylacetamide (800 g). The reaction solution was poured into water (4 L) with stirring to precipitate a white polymer. The polymer was filtered off, washed with water, and then vacuum dried to obtain the following polyurethane resin (P-1) (51.35 g).
The reduced specific viscosity of the obtained polyurethane resin (P-1) was measured by the method described in the specification, and found to be 180 ml / g.

<Synthesis Example 2: Polyurethane resin (P-2)>
Instead of heating at 100 ° C. for 8 hours, a polyurethane resin (P-2) was obtained in the same manner as in Synthesis Example 1, except that heating was performed at 100 ° C. for 2 hours.
It was 50 ml / g when the reduced specific viscosity of the obtained polyurethane resin (P-2) was measured by the method as described in a specification.

<Synthesis Example 3: Polyurethane resin (P-3)>
Instead of heating at 100 ° C. for 8 hours, a polyurethane resin (P-3) was obtained in the same manner as in Synthesis Example 1 except that heating was performed at 100 ° C. for 4 hours.
The reduced specific viscosity of the obtained polyurethane resin (P-3) was measured by the method described in the specification and found to be 80 ml / g.

<Synthesis Example 4: Polyurethane resin (P-4)>
Instead of heating at 100 ° C. for 8 hours, a polyurethane resin (P-4) was obtained in the same manner as in Synthesis Example 1 except that heating was performed at 100 ° C. for 10 hours.
It was 250 ml / g when the reduction | restoration specific viscosity of the obtained polyurethane resin (P-4) was measured by the method as described in a specification.

<Synthesis Example 5: Comparative polyurethane resin (CP-1)>
Instead of heating at 100 ° C. for 8 hours, a polyurethane resin (CP-1) was obtained in the same manner as in Synthesis Example 1 except that heating was performed at 100 ° C. for 1.5 hours.
The reduced specific viscosity of the obtained polyurethane resin (CP-1) was measured by the method described in the specification and found to be 30 ml / g.

<Synthesis Example 6: Comparative polyurethane resin (CP-2)>
Instead of heating at 100 ° C. for 8 hours, a polyurethane resin (CP-2) was obtained in the same manner as in Synthesis Example 1, except that heating was performed at 100 ° C. for 13 hours.
The reduced specific viscosity of the obtained polyurethane resin (CP-2) was measured by the method described in the specification and found to be 300 ml / g.

  The results are shown in Table 1.

[Preparation of lithographic printing plate precursor]
<Example 1>
A negative lithographic printing plate precursor was prepared and evaluated by the following procedure. The results are also shown in Tables 2-4.

-Production of support-
Various treatments (a) to (e) below were continuously performed using an aluminum plate (material 1050) having a thickness of 0.3 mm. In addition, after each process and water washing, the liquid was drained with the nip roller.

(Process (a))
In order to remove rolling oil on the surface of an aluminum plate (material 1050) having a thickness of 0.3 mm, a degreasing treatment was performed at 50 ° C. for 30 seconds using a 10 mass% sodium aluminate aqueous solution, and then the hair diameter was 0.3 mm. Using three bundle-planted nylon brushes and a pumice-water suspension (specific gravity 1.1 g / cm ³ ) having a median diameter of 30 μm, the aluminum surface was grained at a brush rotation speed of 250 rpm, and washed thoroughly with water.

(Process (b))
This plate was etched by being immersed in a 25% aqueous sodium hydroxide solution at 45 ° C. for 9 seconds, washed with water, further immersed in 20% nitric acid at 60 ° C. for 20 seconds, and washed with water. At this time, the etching amount of the grained surface was about 3 g / m ² .

(Process (c))
Next, an electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass nitric acid aqueous solution (containing 0.5% by mass of aluminum ions) and a liquid temperature of 50 ° C. The AC power source waveform is electrochemical roughening treatment using a trapezoidal rectangular wave alternating current with a time ratio TP of 0.8 msec until the current value reaches a peak from zero, a duty ratio of 1: 1, and a trapezoidal rectangular wave alternating current. Went. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode. The amount of electricity in nitric acid electrolysis was 175 C / dm ² when the aluminum plate was the anode. Then, water washing by spraying was performed.

(Process (d))
Next, a 0.5% by mass hydrochloric acid aqueous solution (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. and nitric acid electrolysis under the condition of an electric quantity of 50 C / dm ² when the aluminum plate is an anode. In the same manner as above, an electrochemical surface roughening treatment was performed, followed by washing with water by spraying.

(Process (e))
The plate was provided with a direct current anodic oxide coating of 2.5 g / m ² at a current density of 15 A / dm ² using 15% sulfuric acid (containing 0.5 mass% of aluminum ions) as an electrolyte, and then washed with water, dried and supported. Body A. The centerline average roughness (Ra) of this substrate was measured using a needle having a diameter of 2 μm and found to be 0.51 μm.
An aluminum support was produced as described above.

―Formation of intermediate layer―
Next, the following intermediate layer coating solution was applied to the surface of the aluminum support with a wire bar and dried at 100 ° C. for 10 seconds to form an intermediate layer. The coating amount was 5 mg / m ² .

(Coating liquid for intermediate layer)
-Polymer compound a-1 having the following structure (Mw: 35,000) 0.05 g
・ Methanol 27g
・ Ion exchange water 3g

-Formation of photosensitive layer-
On the obtained intermediate layer, a coating solution for the photosensitive layer having the following composition is prepared and applied using a wire bar so that the coating amount after drying is 1.0 g / m ^2. And dried at 115 ° C. for 34 seconds to form a photosensitive layer.

(Coating solution 1 for photosensitive layer)
・ Infrared absorber (IR-1 below) 0.040g
・ Polymerization initiator A (S-1 below) 0.104 g
・ Polymerization initiator B (I-1 below) 0.153g
・ Mercapto compound (SH-1 below) 0.038 g
-Sensitization aid (T-1 below) 0.121g
・ Polymerizable compound (M-1 below) 0.535g
・ Urethane binder polymer A
(Polyurethane resin (P-1), Mw: 100,000) 0.107 g
・ Acrylic binder polymer B
(The following acrylic resin B-1, Mw: 100,000) 0.267 g
・ Acrylic binder polymer C
(The following acrylic resin C-1, Mw: 100,000) 0.160 g
Copper phthalocyanine pigment dispersion (CI Pigment Blue 15: 6,
Dispersion solvent: MEK / MFG / MA = 2/2/1, pigment solid content 15 wt%) 0.775 g
・ Polymerization inhibitor (Q-1 below) 0.0015g
-Fluorosurfactant (Megafac F-780-F Dainippon Ink & Chemicals,
0.016 g of methyl isobutyl ketone (MIBK) 30% by mass solution)
・ Methyl ethyl ketone 6.481g
・ Methanol 2.738g
・ 5-119 g of 1-methoxy-2-propanol

―Formation of lower protective layer―
On the surface of the photosensitive layer obtained as described above, synthetic mica (Somasif MEB-3L, 3.2% aqueous dispersion, manufactured by Coop Chemical Co., Ltd.), polyvinyl alcohol (Goselan CKS-50: degree of saponification 99 mol) %, Polymerization degree 300, sulfonic acid-modified polyvinyl alcohol Nippon Synthetic Chemical Industry Co., Ltd.) Surfactant A (Nihon Emulsion Co., Emalex 710) and Surfactant B (Adeka Pluronic P-84: Asahi Denka Kogyo Co., Ltd.) Manufactured aqueous solution (coating solution for protective layer) was applied with a wire bar, and dried at 125 ° C. for 30 seconds with a hot air dryer.
The content ratio of synthetic mica (solid content) / polyvinyl alcohol / surfactant A / surfactant B in the mixed aqueous solution (coating liquid for protective layer) was 7.5 / 89/2 / 1.5 (mass). The coating amount (the coating amount after drying) was 0.5 g / m ² .

-Formation of upper protective layer-
On the surface of the lower protective layer, an organic filler (Art Pearl J-7P, manufactured by Negami Industrial Co., Ltd.), synthetic mica (Somasif MEB-3L, 3.2% aqueous dispersion, manufactured by Coop Chemical Co., Ltd.), polyvinyl alcohol ( L-3266: Saponification degree 87 mol%, polymerization degree 300, sulfonic acid-modified polyvinyl alcohol, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., thickener (Serogen FS-B, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), polymer A mixed aqueous solution (coating solution for protective layer) of Compound A (structure shown below) and a surfactant (manufactured by Nippon Emulsion Co., Ltd., Emalex 710) is applied with a wire bar, and heated at 125 ° C. for 30 seconds with a hot air dryer. Dried.
The content ratio of the organic filler / synthetic mica (solid content) / polyvinyl alcohol / thickener / polymer compound A / surfactant in the mixed aqueous solution (protective layer coating solution) is 4.7 / 2.8. /67.4/18.6/2.3/4.2 (mass%), and the coating amount (the coating amount after drying) was 1.8 g / m ² .
Thus, the planographic printing plate precursor of Example 1 was obtained.

<Example 2 to Example 4>
Except for using polyurethane resin (P-2) to polyurethane resin (P-4) instead of polyurethane resin (P-1) used in photosensitive layer coating solution 1, respectively, The planographic printing plate precursors of Examples 2 to 4 were obtained.

<Example 5 to Example 7>
Except for changing the amounts of the urethane-based binder polymer A, the acrylic-based binder polymer B, and the acrylic-based binder polymer C used in the photosensitive layer coating solution 1 as shown in Table 2 below, in the same manner as in Example 1, The planographic printing plate precursors of Examples 5 to 7 were obtained.

<Comparative Examples 1 to 2>
Instead of the polyurethane resin (P-1) used in the coating solution 1 for the photosensitive layer, the same procedure as in Example 1 was conducted except that the comparative polyurethane resin (CP-1) to the comparative polyurethane resin (CP-2) were used. Thus, lithographic printing plate precursors of Comparative Examples 1 and 2 were obtained.

<Comparative Example 3 to Comparative Example 4>
A comparative polyurethane resin (CP-1) is used in place of the polyurethane resin (P-1) used in the photosensitive layer coating solution 1, and the urethane binder polymer A and acrylic binder polymer B used in the photosensitive layer coating solution 1 are used. The lithographic printing plate precursors of Comparative Examples 3 to 4 were obtained in the same manner as in Example 1 except that the amount of the acrylic binder polymer C was changed as shown in Table 3 below.

<Comparative Example 5 to Comparative Example 6>
A comparative polyurethane resin (CP-2) is used in place of the polyurethane resin (P-1) used in the photosensitive layer coating solution 1, and the urethane binder polymer A and the acrylic binder polymer B used in the photosensitive layer coating solution 1 are used. The lithographic printing plate precursors of Comparative Examples 5 to 6 were obtained in the same manner as in Example 1 except that the amount of the acrylic binder polymer C was changed as shown in Table 3 below.

<Comparative Example 7>
Except for changing the amounts of the acrylic binder polymer B and the acrylic binder polymer C used in the photosensitive layer coating solution 1 as shown in Table 3 below without using the urethane binder polymer A in the photosensitive layer coating solution 1. In the same manner as in Example 1, a planographic printing plate precursor of Comparative Example 7 was obtained.

<Example 8>
Except for changing the amounts of the urethane-based binder polymer A, the acrylic-based binder polymer B, and the acrylic-based binder polymer C used in the photosensitive layer coating solution 1 as shown in Table 3 below, in the same manner as in Example 1, The planographic printing plate precursor of Example 8 was obtained.

<Example 9>
The lithographic printing plate precursor of Example 9 was prepared in the same manner as in Example 1 except that 0.021 g of the following (EV-1) was used instead of the copper phthalocyanine pigment dispersion used in the coating solution 1 for photosensitive layer. Obtained.

[Evaluation of lithographic printing plate precursor]
<Example 1 to Example 9, Comparative Example 1 to Comparative Example 7>
―Evaluation of development residue―
The resulting lithographic printing plate precursor was exposed to an FM 50% flat screen at a resolution of 1200 dpi, an outer drum rotation speed of 360 rpm, and an output of 19.5 W using an Amzetter manufactured by NEC. The exposure was performed under conditions of 25 ° C. and 50% RH. After the exposure, neither heat treatment nor water washing treatment is performed, and the developer is DH-N 1: 4 (mass) at a conveyance speed (line speed) of 2 m / min using an automatic developing machine LP-1310HII manufactured by FUJIFILM Corporation. Ratio). In order to perform evaluation under the compulsory conditions, the developing temperature was 25 ° C., and the developer pH was processed with carbon dioxide gas until the charged solution standard was −0.5.
In the lithographic printing plate obtained by development, a non-image portion having no development residue adhered was evaluated as “◯”, and a development residue adhering occurrence was evaluated as “×”.

―Evaluation of sensitivity (Evaluation of developability) ―
The resulting lithographic printing plate precursor was exposed on an Amzisetter manufactured by NEC Corporation with a resolution of 1200 dpi, an outer drum rotation speed of 360 rpm, and an output of 0 to 21 W with a log E of 0.15. The exposure was performed under conditions of 25 ° C. and 50% RH. After the exposure, neither heat treatment nor water washing treatment was performed, and development processing was performed at a conveyance speed (line speed) of 2 m / min and a development temperature of 30 ° C. using an automatic developing machine LP-1310HII manufactured by FUJIFILM Corporation. The developer used was a 1: 4 (mass ratio) water dilution of DH-N, the developer replenisher was a 1: 1.4 (mass ratio) water dilution of FCT-421, and the finisher was FUJIFILM Corporation. A 1: 1 (mass ratio) water dilution of GN-2K manufactured by KK was used.

  The density of the image portion of the lithographic printing plate obtained by development was measured using a Macbeth reflection densitometer RD-918, and the cyan density using a red filter equipped in the densitometer. The reciprocal of the exposure necessary to obtain a measured density of 0.9 was used as an index of sensitivity. The evaluation results were based on the sensitivity of the lithographic printing plate obtained in Example 1 as a standard (100), and the sensitivity of other lithographic printing plates was a relative evaluation thereof. The larger the value, the better the sensitivity.

―Evaluation of printing durability―
The obtained lithographic printing plate precursor was exposed at an resolution of 1200 dpi, an outer drum rotation speed of 360 rpm, and an output of 19.5 W using an Amzetter manufactured by NEC. The exposure was performed under conditions of 25 ° C. and 50% RH. After the exposure, neither heat treatment nor water washing treatment was performed, and development processing was performed at a conveyance speed (line speed) of 2 m / min and a development temperature of 30 ° C. using an automatic developing machine LP-1310HII manufactured by FUJIFILM Corporation. The developer used was a 1: 4 (mass ratio) water dilution of DH-N, the developer replenisher was a 1: 1.4 (mass ratio) water dilution of FCT-421, and the finisher was FUJIFILM Corporation. A 1: 1 (mass ratio) water dilution of GN-2K manufactured by KK was used.

  The resulting lithographic printing plate was printed on a Lithrone printing machine manufactured by Komori Corporation using DIC-GEOS (N) black ink manufactured by Dainippon Ink & Chemicals, Inc. The number of printed sheets when visually recognized was used as an index. In this evaluation result, the printing number of the lithographic printing plate obtained in Example 1 was used as a reference (100), and the printing durability of other lithographic printing plates was evaluated as a relative evaluation. The larger the value, the better the printing durability.

-Evaluation of banding (FM banding) in FM screen printing-
FM banding is a case where multi-channel laser recording using the cylindrical outer surface exposure method scans a plurality of channels for each drum revolution, but when there is variation in the output between channels or when the multi-channel scanning pitch overlaps. This is a phenomenon in which recording unevenness synchronized with the scanning pitch appears on the printed matter. Therefore, to evaluate the difficulty of occurrence of FM banding in a lithographic printing plate, the parameter “slope value” is intentionally shaken during setter exposure to incline the output between channels, print the obtained plate, and print Visually evaluate the degree of banding.

  The obtained lithographic printing plate precursor was standardized with a resolution of 1200 dpi, outer drum rotation speed of 360 rpm, and output of 19.5 W on an Amzisetter manufactured by NEC (in a state adjusted so that multi-channel output is uniform) ± The exposure was shaken by 3% within a range of 12%. The exposure was performed under conditions of 25 ° C. and 50% RH. After the exposure, neither heat treatment nor water washing treatment was performed, and development processing was performed at a conveyance speed (line speed) of 2 m / min and a development temperature of 30 ° C. using an automatic developing machine LP-1310HII manufactured by FUJIFILM Corporation. The developer used was a 1: 4 (mass ratio) water dilution of DH-N, the developer replenisher was a 1: 1.4 (mass ratio) water dilution of FCT-421, and the finisher was FUJIFILM Corporation. A 1: 1 (mass ratio) water dilution of GN-2K manufactured by KK was used.

The obtained lithographic printing plate is printed on a sprint printing machine made by Komori Corporation using DIC-Fusion-G (N) ink made by Dainippon Ink Chemical Co., Ltd. Was rated on a five-point scale.
5: Banding is not seen in the range of standard slope value ± 12% 4: Banding is not seen in the range of standard slope value ± 6% 3: Banding is not seen in the range of standard slope value ± 3% Upper / lower permissible level)
2: Banding is not seen with standard slope value 1: Banding occurs with standard slope value

[Preparation of lithographic printing plate precursor]
<Example 10>
A lithographic printing plate precursor of Example 10 was obtained in the same manner as in Example 1 except that the following photosensitive layer coating liquid 2 was used instead of the photosensitive layer coating liquid 1.

(Photosensitive layer coating solution 2)
-Ethylenically unsaturated bond-containing compound (M-2 below) 0.535 g
-Urethane binder polymer A (the polyurethane resin (P-1)) 0.228 g
・ Acrylic binder polymer B (above acrylic resin B-1) 0.228 g
・ Sensitizer (S-2 below) 0.040g
・ Polymerization initiator (I-2 below) 0.088g
・ Chain transfer agent (T-1) 0.052g
Copper phthalocyanine pigment dispersion (CI Pigment Blue 15: 6,
Dispersion solvent: MEK / MFG / MA = 2/2/1, pigment solid content 15 wt%) 0.38 g
・ Polymerization inhibitor (Q-1 above) 0.0015g
・ Fluorine-based nonionic surfactant Megafac F780 0.0062g
(Dainippon Ink Chemical Co., Ltd.)
・ Methyl ethyl ketone 7.718g
・ Propylene glycol monomethyl ether acetate 7.192 g

<Example 11 to Example 12>
Except for using polyurethane resin (P-2) and polyurethane resin (P-4), respectively, instead of polyurethane resin (P-1) used in photosensitive layer coating solution 2, in the same manner as in Example 10, The planographic printing plate precursors of Examples 11 to 12 were obtained.

<Comparative Example 8 to Comparative Example 9>
Instead of the polyurethane resin (P-1) used in the coating solution 2 for the photosensitive layer, the same procedure as in Example 10 was conducted, except that comparative polyurethane resin (CP-1) to comparative polyurethane resin (CP-2) were used. Thus, lithographic printing plate precursors of Comparative Examples 8 to 9 were obtained.

<Comparative Example 10>
The same as in Example 10 except that the urethane binder polymer A was not used in the photosensitive layer coating solution 2 and the amount of the acrylic binder polymer B used in the photosensitive layer coating solution 2 was changed as shown in Table 4 below. Thus, a planographic printing plate precursor of Comparative Example 10 was obtained.

<Example 13>
The planographic printing plate of Example 13 was the same as Example 1 except that the amounts of the urethane binder polymer A and the acrylic binder polymer B used in the photosensitive layer coating solution 2 were changed as shown in Table 4 below. I got the original version.

[Evaluation of lithographic printing plate precursor]
<Example 10 to Example 13, Comparative Example 8 to Comparative Example 10>
―Evaluation of development residue―
The resulting lithographic printing plate precursor was subjected to a flat screen exposure using Vx9600CTP (light source wavelength: 405 nm) manufactured by Fuji Photo Film Co., Ltd. The exposure was performed under conditions of 25 ° C. and 50% RH. After the exposure, heat treatment and washing with water were not performed, and the developer was DH-N 1: 4 (mass) at a conveyance speed (line speed) of 2 m / min using an automatic developing machine LP-1310HII manufactured by FUJIFILM Corporation. Ratio). In order to perform evaluation under the compulsory conditions, the developing temperature was 25 ° C., and the developer pH was processed with carbon dioxide gas until the charged solution standard was −0.5.
In the lithographic printing plate obtained by development, a non-image portion having no development residue adhered was evaluated as “◯”, and a development residue adhering occurrence was evaluated as “×”.

―Evaluation of sensitivity (Evaluation of developability) ―
Fuji Photo Film Co., Ltd. Fuji step guide (gray scale whose transmission optical density changes discontinuously at ΔD = 0.15) was brought into intimate contact with the obtained photosensitive lithographic printing plate, and Fuji Photo Film Co., Ltd. Exposure was performed with Vx9600CTP (light source wavelength: 405 nm).

  Thereafter, the plate was heated to 115 ° C. using a G & J PS processor IP850HD charged with an alkali developer having the following composition, and then developed with a developer at 25 ° C. for 20 seconds. The maximum number of steps at which the image was completely removed was read, the amount of exposure energy was obtained, and the sensitivity was calculated. The evaluation results were based on the sensitivity of the lithographic printing plate obtained in Example 10 as a reference (100), and the sensitivity of other lithographic printing plates was a relative evaluation thereof. The larger the value, the better the sensitivity.

(Alkali developer composition)
Potassium hydroxide 0.15g
Polyoxyethylene naphthyl ether (n = 13) 5.0 g
Kirest 400 (chelating agent) 0.1g
94.75 g of water

―Evaluation of printing durability―
The resulting lithographic printing plate precursor was image-exposed with an exposure amount of 50 μJ / cm 2 using Vx9600CTP (light source wavelength: 405 nm) manufactured by Fuji Photo Film Co., Ltd. The exposure was performed under conditions of 25 ° C. and 50% RH. After the exposure, neither heat treatment nor water washing treatment was performed, and development processing was performed at a conveyance speed (line speed) of 2 m / min and a development temperature of 30 ° C. using an automatic developing machine LP-1310HII manufactured by FUJIFILM Corporation. The developer used was a 1: 4 (mass ratio) water dilution of DH-N, the developer replenisher was a 1: 1.4 (mass ratio) water dilution of FCT-421, and the finisher was FUJIFILM Corporation. A 1: 1 (mass ratio) water dilution of GN-2K manufactured by KK was used.

  The resulting lithographic printing plate was printed on a Lithrone printing machine manufactured by Komori Corporation using DIC-GEOS (N) black ink manufactured by Dainippon Ink & Chemicals, Inc. The number of printed sheets when visually recognized was used as an index. This evaluation result was based on the number of printed lithographic printing plates obtained in Example 10 as a reference (100), and the printing durability of other lithographic printing plates was a relative evaluation thereof. The larger the value, the better the printing durability.

As is clear from Tables 2 and 4, it can be seen that the planographic printing plate precursors of the examples have a good balance in all of the difficulty of developing residue, sensitivity, printing durability, and difficulty of FM banding.
On the other hand, from Tables 3 and 4, when the reduced specific viscosity of the urethane binder was low, the printing durability was inferior and FM banding occurred. When the reduced specific viscosity was high, development residue was generated under forced conditions. When the urethane binder ratio was more than 50%, the sensitivity was low and the FM banding was poor as compared with the urethane binder ratio in the above range. When a dye was used instead of the organic pigment, the sensitivity and printing durability were lower and the FM banding was worse than when an organic pigment was used.

Claims (4)

A sensitizing dye, a polymerization initiator, a polymerizable compound, and a photosensitive layer containing a binder polymer are sequentially laminated on the support,
The lithographic printing plate precursor, wherein the binder polymer contains a polyurethane resin having a reduced specific viscosity of 50 ml / g to 250 ml / g. The binder polymer further includes an acrylic resin,
The lithographic printing plate precursor as claimed in claim 1, wherein a mass ratio of the polyurethane resin to the acrylic resin is in the range of 1: 9 to 5: 5.   The lithographic printing plate precursor as claimed in claim 1, wherein the photosensitive layer contains an organic pigment.   The lithographic printing plate precursor as claimed in any one of claims 1 to 3, wherein a protective layer is further laminated on the photosensitive layer.