JP2733870B2 - Original plate for direct drawing type lithographic printing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lithographic printing plate, and more particularly, to a direct-drawing lithographic printing plate suitable for an office printing plate.

(Prior art) At present, a direct-drawing lithographic printing original plate having an image receiving layer on a support is widely used as an office printing original plate. In order to make a plate on such a printing original plate, that is, to form an image, in general, oil-based ink is drawn by hand on the image receiving layer, or
A method of printing by a typewriter, an ink jet system, a transfer type thermal system, or the like is employed. In addition, a method of transferring and fixing a toner image formed on a photoreceptor through a charging, exposing and developing process using a plain paper electrophotographic copying machine (PPC) to an image receiving layer has recently started to be used. In any case, the printing original plate after plate making is subjected to surface treatment with a desensitizing solution (so-called etchant) to desensitize the non-image portion, and then subjected to lithographic printing as a printing plate.

Conventional direct-drawing lithographic printing plates have a surface layer provided on both sides of a support such as paper via a back layer and an intermediate layer. The back layer or the intermediate layer is formed of a water-soluble resin such as PVA starch, a water-dispersible resin such as a synthetic resin emulsion, and a pigment. The surface layer is formed of a pigment, a water-soluble resin, and a waterproofing agent.

A typical example of such a lithographic printing plate precursor is U.S. Pat.
As described in No. 2532865, the image-receiving layer is mainly composed of a water-soluble resin binder such as PVA, silica, an inorganic pigment such as calcium carbonate, and a water-resistant agent such as a melamine-formaldehyde resin precondensate. It is composed.

Further, as a binder used in the image receiving layer of the direct drawing type lithographic printing plate precursor, it contains a functional group which generates a carboxyl group, a hydroxyl group or a thiol group, an amino group, a sulfo group and a phosphono group by decomposition, It contains a light-curable functional group and has been crosslinked in advance (Japanese Patent Application No. 63-54609).
And JP-A-63-117035, JP-A-1-269593), and a heat / photocurable resin in combination (JP-A-1-266546 and JP-A-1-275191).
, Japanese Patent Application No. 63-139344) and a crosslinking agent (Japanese Patent Application Laid-Open No.
No. 267093, No. 1-2271292, No. 1-309067), the improvement of the hydrophilicity of the non-image portion and the film strength of the image receiving layer, and the improvement of the printing durability have been studied. .

(Problems to be Solved by the Invention) However, in the conventional printed matter obtained in this manner, in order to improve printing durability, the amount of a water-proofing agent added is increased, or a hydrophobic resin is used. When the hydrophobicity is increased, the printing durability is improved, but the hydrophilicity is reduced, and printing smear is generated. On the other hand, when the hydrophilicity is improved, the water resistance is deteriorated and the printing durability is reduced. Was. In particular, in a high-temperature use environment of 30 ° C. or more, the surface layer was dissolved in immersion water used for offset printing, and there were major drawbacks such as reduction in printing durability and printing stains.

Further, the lithographic printing plate precursor draws an oil-based ink or the like as an image portion on the image receiving layer, and if the adhesiveness between the receiving layer and the oil-based ink is not good, even if the non-image portion has sufficient hydrophilicity, Even if such print stains do not occur, there is a problem that oily ink in the image area is lost during printing, resulting in a reduction in printing durability.

The present invention is to solve the problems of the direct drawing type lithographic printing plate precursor as described above.

SUMMARY OF THE INVENTION An object of the present invention is to provide a direct drawing type lithographic printing plate precursor which is excellent in desensitizing property and does not generate not only a uniform background stain but also a dot background stain as an offset master plate.

An object of the present invention is to improve the adhesiveness between the oil-based ink and the image-receiving layer in the image area, and to maintain the hydrophilicity of the non-image area even when the number of printed sheets is increased in printing, without causing background smear. An object of the present invention is to provide a lithographic printing original plate having high printing durability.

(Means for Solving the Problems) The above-mentioned objects are to provide a direct drawing type lithographic printing plate precursor having an image receiving layer on a support, wherein the binder of the image receiving layer is mainly composed of fluorine atoms and Containing at least one of silicon atoms, a sulfo group by decomposition,
A monofunctional monomer having a functional group generating at least one of a phosphono group, a carboxyl group and a hydroxyl group, and at least one of polymer components represented by the following general formulas (IIa) and (IIb): A monofunctional macromonomer having a weight-average molecular weight of 2 × 10 ⁴ or less which is obtained by bonding a polymerizable double bond group represented by the following general formula (I) to only one end of a main chain of a polymer containing one kind: Has been found to be solved by a direct-drawing lithographic printing plate precursor characterized in that it contains at least one type of graft copolymer consisting of

General formula (I) In the formula (I), X ₁ represents —COO—, —OCO—, CH _{2 n} OCO—,
_{CH 2 m COO -, - O} -, - SO 2 -, - CO-, -CONHCOO-, -CONHCONH- or (D ₁ represents a hydrogen atom or a hydrocarbon group; n,
m represents an integer of 1 to 4).

a ₁ and a ₂ may be the same or different from each other, and represent a hydrogen atom,
A cyano group, a hydrocarbon group, a -COO-Z ₁ or -COO-Z ₁ via a hydrocarbon (Z ₁ represents a hydrogen atom or an optionally substituted hydrocarbon group).

General formula (IIa) General formula (IIb) In formula (IIa) or (IIb), X ₂ represents the same content as X ₁ in formula (I). R ₁ represents an aliphatic group having 1 to 18 carbon atoms or an aromatic group having 6 to 12 carbon atoms. b ₁ and b ₂ may be the same or different, and represent the same contents as a ₁ and a ₂ in the formula (I).

R ₂ is -CN, -CONH ₂ or Wherein Y represents a hydrogen atom, a halogen atom, an alkoxy group or —COOZ ₂ (Z ₂ represents an alkyl group, an aralkyl group or an aryl group).

The present invention relates to a lithographic printing plate precursor comprising at least one hydrophilic group (sulfo group, phosphono group, carboxyl group) containing at least a fluorine atom and / or a silicon atom as a binder resin of the image receiving layer. And / or a hydroxyl group) is characterized by containing a graft-type copolymer comprising at least a monofunctional monomer containing at least one functional group and a monofunctional macromonomer. As a result, the direct-printing type lithographic printing plate precursor according to the present invention has good hydrophilicity in the non-image area, does not cause background fouling, has good adhesiveness between the receiving layer and the oil-based ink, and has a long press life. It has the advantage of excellent power.

Furthermore, the lithographic printing plate precursor of the present invention is characterized by being unaffected by the environment during the plate making process and having excellent storage stability before the process.

The known resin is a resin that is decomposed to generate a hydrophilic group, and when the oil-based ink or the like is drawn on the image-receiving layer as an image portion, since the oil-based ink contains a lipophilic group, the resin and the oil-based ink are used. Since the adhesion and the hydrophilicity after the decomposition are made hydrophilic, the lipophilicity of the image area and the hydrophilicity of the non-image area are distinguished, and the prevention of background stain is improved, and the printing durability is further improved.

However, it was not satisfactory in prevention of background stain and printing durability.

On the other hand, the binder resin according to the present invention is a polymer component containing a functional group that protects a hydrophilic group with a protecting group containing a fluorine atom and / or a silicon atom and decomposes to form a hydrophilic group: It is a graft copolymer comprising a segment A and a polymer component corresponding to a monofunctional macromonomer: a segment B. The resin of the present invention has a specific behavior in the image receiving layer, unlike the conventionally known random copolymer. That is, when the resin of the present invention is used alone as the main component of the image receiving layer, it is presumed that a microphase-separated structure is formed due to the difference in compatibility between the segment A and the segment B. Since there is a tendency for a large number of segments A to generate a hydrophilic group later in the portion, the effect of improving the hydrophilicity of the non-image portion is further enhanced, and the hydrophilicity of the image portion is clearly distinguished from that of the image portion. It is thought that it appears as an effect of preventing contamination.

Furthermore, the segment A which is concentrated and present on the surface portion of the image receiving layer has a strong lipophilicity to the extent that it causes a transition phenomenon to the surface when drawing oily ink or the like as an image portion on the image receiving layer. Therefore, the adhesion between the receiving layer and the oil-based ink or the like is improved, and the printing durability is improved.

Furthermore, in the resin of the present invention in which a hydrophilic group is generated by a desensitizing treatment, the hydrophilic segment A portion faces the surface side, while the lipophilic segment B portion faces the opposite side of the surface, and the like. Interacts with the binder resin and / or zinc oxide to exhibit an anchor effect, thereby suppressing elution of the resin into the etchant and / or the fountain solution during printing. And good hydrophilicity can be maintained, and a large number of prints with good image quality can be obtained.

Hereinafter, a fluorine atom and / or silicon atom-containing functional group which is decomposed to form at least one hydrophilic group (hereinafter, may be simply referred to as a hydrophilic group-forming functional group) used in the present invention. explain in detail.

Although the hydrophilic group-forming functional group of the present invention generates a hydrophilic group by decomposition, the number of hydrophilic groups generated from one functional group may be one or two or more.

According to one preferred embodiment of the present invention, the graft copolymer containing a hydrophilic group-forming functional group is a resin containing at least one functional group represented by the general formula (IV).

-COOH group as one of the preferred embodiments of the hydrophilic group-forming functional group of the present invention, the functional group which forms a -SO ₃ H group or a -PO ₃ H ₂ group will be described.

The general formula (IV) -V-O-L ₁ V is Represents

L ₁ is -CF ₃ , Or represents the _{CH 2) 2 SO 2 P 8} .

L ₁ In the case of, P ₁ is a hydrogen atom, -CN group, -CF ₃ group, C
Represents an OR ₁₁ group or a —COOR ₁₁ group. However, R ₁₁ has 1 to 1 carbon atoms.
6 alkyl groups (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, etc.), carbon number 7
To 12 optionally substituted aralkyl groups (specifically, benzyl group, phenethyl group, chlorobenzyl group, methoxybenzyl group, chlorophenethyl group, methylphenethyl group, etc.), aromatic group (for example, containing a substituent A phenyl group or a naphthyl group: specifically, a phenyl group, a chlorophenyl group, a dichlorophenyl group, a methylphenyl group,
Methoxyphenyl group, acetylphenyl group, acetamidophenyl group, methoxycarbonylphenyl group, a naphthyl group, _{etc.), CH 2 n1 CF 2 m1} CF 2 H ( wherein n ₁ is an integer and m ₁ 1 or 2 for 1-8 Represents an integer), CH _{2 n2} C
_m2 H _{2m2 + 1} (where n ₂ is 0 or the integer 2 and m ₂ represents an integer of 1-8) or [N ₃ represents an integer of 1 to 6 and m ₃ represents an integer of 1 to 4,
Represents a single bond or -O-.

R ₁₂ and R ₁₃ may be the same or different, and each is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms (specifically, a methyl group,
Ethyl group, propyl group, butyl group, etc.).

R ₁₄ , R ₁₅ and R ₁₆ may be the same or different and each represents a hydrocarbon group which may be substituted and has 1 to 12 carbon atoms or an —OR ₁₇ group (R ₁₇ represents a hydrocarbon group). Here, the specific contents of the hydrocarbon group and the hydrocarbon group of R ₁₇ represent the same contents as those of the aforementioned hydrocarbon group of R ₁₁ ].

P ₂ represents a —CF ₃ group, a —COR ₁₁ group, or a —COOR ₁₁ group (provided that R ₁₁ represents the same symbol as described above).

Furthermore, it is necessary to at least substituent fluorine atom or a silicon atom contained in either one is selected at P ₁ and P _2.

L ₁ In the formula, P ₃ , P ₄ and P ₅ represent the same contents as R ₁₄ , R ₁₅ and R ₁₆ .

L ₁ For, P ₆ and P ₇ may be the same or different, and each R ₁₁
Represents the same content as. However, either the P ₆ and P ₇ is at least a fluorine atom or a silicon atom-containing substituents are chosen.

L ₁ is - (CH ₂₎ For ₂ SO ₂ P _8, P ₈ is _{CH 2 n1 CF 2 m1 CF 2} H _{group, CH 2 2 C m2 H 2m2} + 1 group or The expressed, the contents represent the same contents as the contents respectively corresponding in R ₁₁ described above.

L ₁ In the case of V ₁ represents an organic residue forming a cyclic imide group, containing a substituent containing a fluorine atom and a silicon atom. Specifically, as the cyclic imide ring residue to be formed,
Examples include a maleic imide group, a glutaconimide group, a succinimide group, and a phthalic imide group. As the substituent containing a fluorine atom and / or silicon atoms, and the hydrocarbon group represented by P _8, and -S-P ₉ group (P ₉ represents the same content as P ₈₎ or the like .

One of the preferred embodiments of the present invention includes a hydroxyl group-forming functional group, and specifically includes the following general formulas (V) to (V).
(VII).

In the general formula (V) -O-L ₂ formula (V), L ₂ is Represents P ₃ , P ₄ and P ₅ are the same as those described above.

General formula (VI) In the formula (VI), R ₃ and R ₄ may be the same or different from each other and represent a hydrogen atom or a group having the same contents as R ₁₁ . However, at least one of R ₃ and R ₄ is selected from a substituent containing a fluorine atom and / or a silicon atom.

V ₂ represents a carbon-carbon bond which may be via a hetero atom (provided that the number of atoms between oxygen atoms is within 5).

General formula (VII) In the formula (VII), V ₂ , R ₃ and R ₄ are as defined above.

Specific examples of the functional groups represented by formulas (IV) to (VII) of the present invention are described below. However, the scope of the present invention is:
It is not limited to these.

_{(14) -SO 2 -O-CF} 3 - (15) -SO 2 -OCH 2) 2 SO 2 CF 3 (16) -SO 2 -OCH 2) 2 SO 2 CH 2 CF 3 (17) -SO 2 —OCH ₂ ) ₂ SO ₂ (CH ₂ ) ₂ C ₃ F ₇ (24) -O-Si (C 2 H 5) 3 As described above, the copolymer components containing the functional groups of the general formulas (IV) to (VII) used in the method for producing a desired resin by a polymerization reaction will be more specifically described.
For example, components represented by the following general formula (VIII) can be mentioned. However, it is not limited to these copolymer components.

General formula (VIII) In the formula (VIII), X ′ represents —O—, —CO—, —COO—,
−OCO−, -CH ₂ COO-, CH ₂ OCO-, Represents an aromatic group or a heterocyclic group (provided that e ₁ , e ₂ , e ₃ ,
e ₄ represents a hydrogen atom, a hydrocarbon group, or Y′-W in formula (VIII), and f ₁ and f ₂ may be the same or different, and each represents a hydrogen atom, a hydrocarbon group, or a formula (VIII), and l represents an integer of 0 to 18].

Y ′ represents a carbon-carbon bond which connects the bonding group X ′ and the bonding group [W] and may be via a hetero atom (hetero atoms represent an oxygen atom, a sulfur atom and a nitrogen atom); For example CH = CH, -O-, -S-, -COO -, - CONH -, - SO 2 -, - SO 2 NH -, - NHCOO-,
Which has the constitution alone or in combination of coupling units such as -NHCONH- (where f _3, f _4, f ₅ is the same as each said f _1, f _2.) W has the formula (IV) ~ Represents a functional group represented by (VII).

c ₁ and c ₂ may be the same or different and include a hydrogen atom, a halogen atom (eg, a chlorine atom, a bromine atom, etc.), a cyano group, a hydrocarbon group (eg, a methyl group, an ethyl group, a propyl group, a butyl group, A methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group, hexyloxycarbonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, butoxycarbonylmethyl group, etc.
Alkyl, benzyl, aralkyl such as phenethyl, aryl such as phenyl, tolyl, silyl, chlorophenyl, etc.) or a substituent containing a -W group in formula (VIII). Which may represent an alkyl group, an alkenyl group, an aralkyl group, an alicyclic group, or an aromatic group having 1 to 18 carbon atoms.

Further, the [-X'-Y'-] bonding residue in the formula (VIII) is You may connect a part and -W directly.

W represents the symbolic content represented by the general formulas (IV) to (VII).

Next, the monofunctional macromonomer (M) constituting another copolymer component of the graft copolymer of the present invention will be described.

The monofunctional macromonomer (M) is prepared by adding a polymerizable double bond group represented by the general formula (I) to the general formulas (IIa) and (IIb).
Having a weight average molecular weight of 2 × 10 ⁴ or less which is bonded to only one end of a polymer main chain containing at least one of the polymer components represented by

In the general formula (I) of the macromonomer (M), X ₁ represents —COO—, —OCO—, CH _{2 n} OCO—, CH _{2 m} C
OO -, - O -, - SO 2 -, Represents

 Here, n and m each represent an integer of 1 to 4.

d ₁ is a hydrogen atom, as a preferred hydrocarbon group,
An alkyl group having 1 to 18 carbon atoms which may be substituted (for example,
Methyl, ethyl, propyl, butyl, heptyl, hexyl, octyl, decyl, dodecyl,
Hexadecyl group, octadecyl group, 2-chloroethyl group, 2-bromoethyl group, 2-cyanoethyl group, 2-methoxycarbonylethyl group, 2-methoxyethyl group, 3
-Bromopropyl group and the like, and an optionally substituted alkenyl group having 4 to 18 carbon atoms (eg, 2-methyl-1-propenyl group, 2-butenyl group, 2-pentenyl group, 3-methyl-2-pentenyl group) , A 1-pentenyl group, a 1-hexenyl group, a 2-hexenyl group, a 4-methyl-2-hexenyl group and the like) an aralkyl group having 7 to 12 carbon atoms which may be substituted (for example, benzyl group, phenethyl group, 3 -Phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group,
Chlorobenzyl group, bromobenzyl group, methylbenzyl group, ethylbenzyl group, methoxybenzyl group, dimethylbenzyl group, dimethoxybenzyl group, etc.), having 5 to 8 carbon atoms
An optionally substituted alicyclic group (e.g., cyclohexyl group, 2-cyclohexylethyl group, 2-cyclopentylethyl group, etc.) or an optionally substituted aromatic group having 6 to 12 carbon atoms (e.g., Phenyl, naphthyl, tolyl, xylyl, propylphenyl, butylphenyl, octylphenyl, dodecylphenyl, methoxyphenyl, ethoxyphenyl, butoxyphenyl, decyloxyphenyl, chlorophenyl, dichlorophenyl Bromophenyl group, cyanophenyl group, acetylphenyl group, methoxycarbonylphenyl group, ethoxycarbonylphenyl group, butoxycarbonylphenyl group, acetamidophenyl group, propioamidophenyl group, dodecyloylamidophenyl group, etc.).

X ₁ In the formula, the benzyl ring may have a substituent.
Examples of the substituent include a halogen atom (eg, a chlorine atom, a bromine atom, etc.), an alkyl group (eg, a methyl group, an ethyl group,
A propyl group, a butyl group, a chloromethyl group, a methoxymethyl group and the like; an alkoxy group (for example, a methoxy group, an ethoxy group, a propoxy group and a butoxy group).

a ₁ and a ₂ may be the same or different from each other, and are preferably a hydrogen atom, a halogen atom (eg, a chlorine atom or a bromine atom), a cyano group, an alkyl group having 1 to 4 carbon atoms (eg, a methyl group, An ethyl group, a propyl group, a butyl group or the like), -COO-Z ₁ or COOZ ₁ via a hydrocarbon (Z ₁ is a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, an alkenyl group,
Represents an aralkyl group, an alicyclic group or an aryl group, which may be substituted, specifically, represent represent) the same contents as those described above d _1.

Examples of the hydrocarbon in the —COO—Z ₁ group via the above hydrocarbon include a methylene group, an ethylene group, and a propylene group.

More preferably, in the general formula (I), X ₁ is -COO
-, - OCO -, - CH 2 OCO -, - CH 2 COO -, - O -, - CON
H, -SO ₂ NH- or Represents a ₁ and a ₂ may be the same or different from each other, and represent a hydrogen atom, a methyl group, -COO-Z ₁ or -CH ₂ COOZ ₁ (Z ₁ is
A hydrogen atom or an alkyl group having 1 to 6 carbon atoms (eg, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, etc.)
Represents). Even more preferably, one of a ₁ and a ₂ always represents a hydrogen atom.

That is, as the polymer double bond group represented by the general formula (I), specifically, And the like.

In the general formula (IIa), X ₂ has the same content as X ₁ in the formula (I). b ₁ and b ₂ may be the same or different, and represent the same contents as a ₁ and a ₂ in the formula (I).

R ₁ represents an aliphatic group having 1 to 18 carbon atoms or an aromatic group having 6 to 12 carbon atoms.

Specifically, an alkyl group having 1 to 18 carbon atoms which may be substituted (for example, a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, a hexyl group, an octyl group, a decyl group,
Dodecyl, tridecyl, hexadecyl, octadecyl, 2-chloroethyl, 2-bromoethyl, 2
-Hydroxylethyl group, 2-methoxyethyl group, 2-
Ethoxyethyl group, 2-cyanoethyl group, 3-chloropropyl group, 2- (trimethoxysilyl) ethyl group, 2-
Tetrahydrofuryl group, 2-thienylethyl group, 2-N,
N-dimethylaminoethyl group, 2-N, N-diethylaminoethyl group, etc., C5-C8 cycloalkyl group (for example, cycloheptyl group, cyclohexyl group, cyclooctyl group, etc.), C7-C12 substitution Aralkyl groups (eg, benzyl, phenethyl, 3-phenylpropyl, naphthylmethyl, 2-naphthylethyl,
Aliphatic groups such as chlorobenzyl group, bromobenzyl group, dichlorobenzyl group, methylbenzyl group, chloro-methyl-benzyl group, dimethylbenzyl group, trimethylbenzyl group, and methoxybenzyl group.

Further, an optionally substituted aryl group having 6 to 12 carbon atoms (eg, phenyl, tolyl, xylyl, chlorophenyl, bromophenyl, dichlorophenyl, chloro-methyl-phenyl, methoxyphenyl, methoxycarbonylphenyl) , A naphthyl group, a chloronaphthyl group, etc.). In the formula (IIa), X ₂ is preferably —COO—, —OCO—, —CH ₂ COO—, —CH ₂ OCO
-, - O -, - CO -, - CONH -, - SO 2 NH- or Represents

Preferred examples of b ₁ and b ₂ represent the same contents as those of a ₁ and a ₂ described above.

In the formula (IIb), R ₂ represents —CN, —CONH ₂ or Y represents a hydrogen atom, a halogen atom (eg, a chlorine atom, a bromine atom, etc.), an alkoxy group (eg, a methoxy group,
Ethoxy, etc.) or -COOR '(R' preferably represents an alkyl group having 1 to 8 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aryl group).

The macromonomer (M) may contain two or more polymer components represented by the formula (II).

When R ₁ is an aliphatic group in the formula (IIa), it has 6 carbon atoms.
It is preferable to use the aliphatic groups of 12 to 12 in a range not exceeding 20% by weight of the total polymer components in the macromonomer (M).

Further, when X ₂ in the general formula (IIa) is —COO—, at least 30% by weight or more of the polymer component represented by the formula (IIa) in all the polymer components in the macromonomer (M). It is preferable to be contained. In the macromonomer (M), acrylonitrile, methacrylonitrile, acrylamides, methacrylamide as monomers corresponding to the repeating unit copolymerizable with the polymer component represented by the formula (IIa) and / or (IIb). , Styrene and its derivatives (eg, vinyl toluene, chlorostyrene, dichlorostyrene, bromostyrene, hydroxymethylstyrene, N, N-dimethylaminomethylstyrene, etc.), heterocyclic vinyls (eg, vinylpyridine, vinylimidazole, vinylpyrrolidone, Vinylthiophene,
Vinylpyrazole, vinyldioxane, vinyloxazine, etc.).

The macromonomer used in the present invention is represented by the general formula (I) only at one end of the polymer main chain composed of the repeating units represented by the general formulas (IIa) and / or (IIb) as described above. The polymerizable double bond group has a chemical structure in which it is directly bonded or bonded with an arbitrary linking group. Formula (I) component and formula (IIa) or (IIb)
Examples of the group linking the components include a carbon-carbon bond (single bond or double bond) and a carbon-hetero atom bond (hetero atoms include, for example, an oxygen atom, a sulfur atom, a nitrogen atom,
Silicon atom) and any combination of heteroatom-heteroatom bond atomic groups.

Preferred among the macromonomers (M) of the present invention are those represented by the formula (IIIa) or (IIIb).

Formula (IIIa) Formula (IIIb) In the formulas (IIIa) and (IIIb), a ₁ , a ₂ , b ₁ , b ₂ , X ₁ , X ₂ ,
R ₁ and R ₂ represent the same contents as described in the formulas (I), (IIa) and (IIb), respectively.

Y ₁ is a mere bond or [D ₂ and d ₃ represent a hydrogen atom, a halogen atom (eg, a fluorine atom, a chlorine atom, a bromine atom, etc.), a cyano group, a hydroxyl group, an alkyl group (eg, a methyl group, an ethyl group, a propyl group, etc.)] , CH = CH, Represents a hydrogen atom or a hydrocarbon group having the same content as R ₁ in the formula (IIa), etc.], or a single linking group selected from an atomic group such as .

When the weight average molecular weight of the macromonomer (M) exceeds 2 × 10 ⁴ , the copolymerizability with the monomer represented by the monofunctional monomer of the present invention decreases. On the other hand, if the molecular weight is too small, the effect of improving the electrophotographic properties of the photosensitive layer becomes small.
It is preferably at least × 10 ³ .

The macromonomer (M) of the present invention can be produced by a conventionally known synthesis method. For example, a method by an ionic polymerization method in which various reagents are reacted with a terminal of a living polymer obtained by anionic polymerization or cationic polymerization to form a macromer, a carboxyl group in a molecule,
Using a polymerization initiator and / or a chain transfer agent containing a reactive group such as a hydroxy group or an amino group, an oligomer having a terminal reactive group bond obtained by radical polymerization is reacted with various reagents to form a macromer. And the like, and a method by a polyaddition condensation method in which a polymerizable double bond group is introduced into an oligomer obtained by a polyaddition or polycondensation reaction in the same manner as the above-mentioned radical polymerization method.

Specifically, P.Dreyfuss & R.P.Quirk, Encycl, Polym.S
ci.Eng., 7 , 551 (1987), PFRempp, E.Franta, Adu., Pol
ym.Sci., 58 , 1 (1984), V.Percec, Appl., Polym.Sci., 28
5 , 95 (1984), R. Asami, M. TakaRi, Makvamol. Chem. Supp
l. 12 , 163 (1985), P. Rempp. et al, Makvamol. Chem. Supp.
l, 8 , 3 (1984), Yusuke Kawakami, Chemical Industry, 38 , 56 (1987),
Yuya Yamashita, polymer, 31, 988 (1982), Shiro Kobayashi, polymer, 30, 625 (1981), Higashimura Satoshinobe, Journal of the Adhesion Society of Japan, 18, 536
(1982), Koichi Ito, polymer processing, 35, 262 (1986), AzumaTakashi Shiro, Takashi Tsuda, functional materials, according to the method described in the review, such as 1987 Nanba10,5 and it references the literature, patents, etc. Can be synthesized.

Specific examples of the macromonomer (M) of the present invention include the following compounds. However, the scope of the present invention is not limited to these.

Also a ₁ in each of the following examples represents -H or -CH _3, b ₁ represents -H, a -CH ₃ or -CH ₂ COOCH _3, b ₂ is -
Represents H or -CH _3, R ₁ is _{-C n H 2n + 1 (n} = 1~18 _{integer), - CH 2 C 6 H} 5, -C 6 H 5 or Are shown, R ₂ is _{-C n H 2n + 1, -} (CH 2) m C 6 H 5 (m = 1~3
Integer) or (Y ₁ is -CH _3, -Cl, -Br, shows a -OCH ₃₎ indicates, R ₃
Is -C _n H _{2n +} 1, shows a -CH ₂ C ₆ H ₅ or -C ₆ H _5, R ₄ is -C _n
H _{2n + 1} or indicates _{-CH 2 C 6 H 5, R} 5 is _{-C n H 2n + 1, -CH} 2 C 6
H ₅ or Shown -Cl, -Br, and shows a -CH ₃ or -OCH _3), R ₆
Indicates -C _n H _{2n + 1} is, X ₁ is -COOCH _3, -C ₆ H ₅ or -CN
Are shown, X ₂ is _{-OC n H 2n + 1, -OCOC} q H 2q + 1 (q = 1~18 _{integer), - COOCH 3, -C 6} H 5) or indicates -CN, X ₃ is −
COOCH ₃ , C ₆ H ₅ , (Y ₂ are -Cl, shows -Br or -CH ₃₎ or indicates -CN, X ₄ represents -Cl, -Br, -F, and -OH, or -CN, X ₅
The _{-OCOC n H 2n + 1, -CN} , shows a -CONH ₂ or -C ₆ H _5, X
₆ represents -CN, a -CONH ₂ or -C ₆ H _5, X ₇ is -COOCH _3,
−C ₆ H ₅ or (Y ₁ represents -Cl, -Br, -CH ₃ or -OCH ₃ ), and X ₈ represents -H, -CH ₃ , -Cl, -Br, -OCH ₃ or -COO.
CH ₃ is indicated, and P is an integer of 2 to 4.

Furthermore, the graft copolymer of the present invention contains, in addition to the above-mentioned monofunctional monomer containing a hydrophilic group-forming functional group and the above-mentioned monomer (M), other monomers other than these as a copolymerization component. May be.

For example, α-olefins, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide,
Styrene, vinyl group-containing naphthalene compounds (eg, vinyl-naphthalene, 1-isopropenylnaphthalene, etc.),
Examples include compounds such as a vinyl group-containing heterocyclic compound (for example, vinylpyridine, vinylpyrrolidone, vinylthiophene, vinyltetrahydrofuran, vinyl-1,3-dioxolan, vinylimidazole, vinylthiazole, vinyloxazoline, and the like).

The polymer component corresponding to the hydrophilic group-forming functional group-containing monomer (A) in the graft copolymer of the present invention accounts for 30 to 90% by weight, particularly 40 to 80% by weight of the whole polymer. Is preferred. The polymer component corresponding to the monofunctional macromonomer (M) in the total polymer is 10 to 70% by weight, particularly 20% by weight.
Preferably it is 6060% by weight. Further, it is preferable that other polymer components other than the above do not exceed at most 30% by weight.

The weight average molecular weight of the copolymer is 10 ³ to 10 ⁶ , especially 5
It is preferably from × 10 ^{3 to} 5 × 10 ⁵ .

When the content of the monomer (A) is 30% by weight or less or the content of the macromonomer (M) is 70% by weight or more, the effect of improving the water retention when desensitized and printed as an offset printing original plate is diminished.

On the other hand, when the content of the monomer (A) is 90% by weight or more or the content of the macromonomer (M) is 10% by weight or less, the effect of improving water retention cannot be maintained when the number of printed sheets in printing increases.

The graft copolymer of the present invention comprises a polymer component containing a fluorine atom and / or a silicon atom (segment A).
Parts) and a polymer component (:
(Segment B portion), but when the image receiving layer is formed, since the segment A portion has remarkable lipophilicity, a transition phenomenon occurs on the surface portion of the image receiving layer, and despite the small usage ratio, It is presumed that the graft copolymer of the present invention can be present in a concentrated manner on the surface portion. Furthermore,
The copolymer containing the segment A portion containing the hydrophilic group-forming functional group of the present invention is hydrolyzed, hydrolyzed, or photolyzed by a desensitizing solution or a fountain solution used for printing to produce a hydrophilic group.

Therefore, as described above, when a resin is used as a main component of the image-receiving layer of the direct-drawing lithographic printing plate precursor, the hydrophilicity of the non-image portion rendered hydrophilic by the desensitizing solution increases Since the segment A containing the hydrophilic group generated in the above is further enhanced by being concentrated on the surface portion, the lipophilicity of the image portion and the hydrophilicity of the non-image portion become clear, and the non-image Prevents printing ink from adhering to parts.

On the other hand, as described above, since the resin of the present invention containing a hydrophilic group formed by decomposition by fountain solution during etching and printing on a printing machine is a graft copolymer, the macromonomer (M The segment B portion corresponding to the portion ()) is lipophilic and significantly interacts with other binder resins. Therefore, the segment B portion acts as an anchor to prevent dissolution and elution. Has an effect. Therefore, even if a large number of sheets are printed, the hydrophilicity of the non-image area is maintained, and high printing durability can be achieved.

As a method of decomposing a specific functional group in the resin of the present invention by light irradiation, a step of irradiating light with "chemically active light" between any of after obtaining a toner image in plate making may be included. I just need. That is, after the electrophotographic development, light irradiation may be performed also to fix the toner image at the time of fixing, or after fixing by other conventionally known fixing methods, for example, heat fixing, pressure fixing, solvent fixing, etc. Irradiation is performed.

The “chemically active light” used in the present invention may be any of visible light, ultraviolet light, far ultraviolet light, electron beam, X-ray, γ-ray, α-ray, etc., and preferably includes ultraviolet light. More preferably, it can emit light in a wavelength range of 310 nm to 500 nm, and generally a high-pressure or ultra-high-pressure mercury lamp or the like is used. The light irradiation treatment can be sufficiently carried out by irradiation from a distance of 5 cm to 50 cm for 10 seconds to 10 minutes.

A conventionally known resin can be used together with the resin provided in the present invention. For example, silicone resin, alkyd resin, vinyl acetate resin, polyester resin, styrene-butadiene resin, acrylic resin and the like as described above are mentioned, and specifically, Ryuji Kurita and Jiro Ishiwatari, Polymer, No. 17
Vol., P. 278 (1968), Harumi Miyamoto, Hidehiko Takei, Imaging, 1973 (No. 8), page 9, and the like.

As another component of the image receiving layer of the present invention, an inorganic pigment is used. As the inorganic pigment, for example, kaolin clay, calcium carbonate, silica, titanium oxide, zinc oxide,
Examples include barium sulfate and alumina.

The ratio of the binder resin / pigment in the image receiving layer differs depending on the kind of the material and the particle size in the case of the pigment, but is generally about 1 / (0.5 to 5), preferably about 1 / (0.8 to 2.5) by weight. Is appropriate.

Examples of the support used in the present invention include high-quality paper, wet-strengthened paper, plastic films such as polyester films, and metal plates such as aluminum plates.

In the present invention, an intermediate layer is provided between the support and the image receiving layer for the purpose of improving water resistance and interlayer adhesion, and a back coat layer is provided on the surface of the support opposite to the image receiving layer for the purpose of preventing curling. Can be.

Here, the intermediate layer is an emulsion resin such as an acrylic resin, a styrene-butadiene copolymer, a methacrylate-butadiene copolymer, an acrylonitrile-butadiene copolymer, an ethylene-vinyl acetate copolymer; an epoxy resin, a polyvinyl butyral , Polyvinyl chloride, polyvinyl acetate, and other solvent-based resins; composed of at least one of the above-mentioned water-soluble resins as a main component, and adding an inorganic pigment or a water-proofing agent as necessary. Can also.

 The configuration of the back coat layer is almost the same as that of the intermediate layer.

When used as a PPC plate making, in order to further reduce the background stain of the printing base plate of the present invention, as the volume resistivity of the printing plate is 10 ¹⁰ to 10 ¹³ [Omega] cm, further image-receiving layer, an intermediate layer and And / or a dielectric agent can be added to the back coat layer. The dielectric agent may be an inorganic one or an organic one. In the case of an inorganic one, Na, K, Li,
Salts of monovalent or polyvalent metals such as Mg, Zn, Co, Ni, etc., and organic cation conductive agents such as polyvinylbenzyltrimethylammonium chloride and quaternary ammonium salts modified with acrylic resin, and organic sulfonic acids Polymeric anionic conductive agents such as salts are included. The amount of these conductive agents is 3 to 40% by weight, preferably 5 to 20% by weight, based on the amount of the binder used in each layer.

In order to prepare the lithographic printing plate precursor of the present invention, an aqueous liquid containing an intermediate layer component is coated on one side of the support, if necessary, and dried to form an intermediate layer. Is applied and dried to form an image-receiving layer, and if necessary, an aqueous liquid containing a backcoat layer component is applied and dried on the other surface to form a backcoat layer. The image receiving layer,
The amount of each of the intermediate layer and the back coat layer is 1 to 30 g / m ² ,
5-20 g / m ² is suitable.

(Examples) Examples of the present invention will be described below, but the contents of the present invention are not limited thereto.

Production Example 1 of Macromonomer 1: A mixed solution of 95 g of MM-1 methyl methacrylate, 5 g of thioglycolic acid and 200 g of toluene was stirred under a nitrogen stream while stirring.
Heated to a temperature of 75 ° C. 1.0 g of 2,2'-azobisisobutyronitrile (abbreviation: AIBN) was added and reacted for 8 hours. Next, 8 g of glycidyl methacrylate and N, N-
1.0 g of dimethyldodecylamine and 0.5 g of t-butylhydroquinone were added, and the mixture was stirred at a temperature of 100 ° C. for 12 hours. After cooling, this reaction solution was reprecipitated in 2 l of methanol to obtain 82 g of a white powder. The weight average molecular weight (hereinafter, w) of the polymer is 8.3
× was 10 ^3.

Production Example 2 of Macromonomer: MM-2 A mixed solution of 95 g of methyl methacrylate, 5 g of thioglycolic acid, and 200 g of toluene was heated to 70 ° C. while stirring under a nitrogen stream. 1.5 g of AIBN was added and reacted for 8 hours. Next, glycidyl methacrylate 7.
5 g, N, N-dimethyldodecylamine 1.0 g and t-butylhydroquinone 0.8 g were added, and the mixture was stirred at a temperature of 100 ° C. for 12 hours. After cooling, the reaction solution was reprecipitated in 2 l of methanol to obtain 85 g of a colorless and transparent viscous substance. The polymer w is 4.5 ×
It was 10 ³ .

Production Example 3 of Macromonomer: A mixed solution of 94 g of MM-3 butyl methacrylate, 6 g of 2-mercaptoethanol and 200 g of toluene was heated to a temperature of 70 ° C. under a nitrogen stream. 1.2 g of AIBN was added and reacted for 8 hours.

Next, the reaction solution was cooled in a water bath to a temperature of 20 ° C.,
Triethylamine (10.2 g) was added, and methacrylic acid chloride (14.5 g) was added dropwise with stirring at a temperature of 25 ° C. or lower. After the addition, the mixture was further stirred for 1 hour. Thereafter, 0.5 g of t-butylhydroquinone was added, the mixture was heated to a temperature of 60 ° C., and stirred for 4 hours.
After cooling, the precipitate was reprecipitated in 2 l of methanol to give a colorless transparent viscous substance 79
g was obtained. w was 6.3 × 10 ³ .

Production Example 4 of Macromonomer: MM-4 A mixed solution of 95 g of ethyl methacrylate and 200 g of toluene was heated to a temperature of 70 ° C. under a nitrogen stream. 5 g of 2,2'-azobis (cyanoheptanol) was added and reacted for 8 hours.

After cooling, the temperature of the reaction solution was adjusted to 20 ° C. in a water bath, 1.0 g of triethylamine and 21 g of methacrylic anhydride were added, and the mixture was stirred for 1 hour and then at 60 ° C. for 6 hours.

The obtained reaction product was cooled and then reprecipitated in 2 l of methanol to obtain 75 g of a colorless and transparent viscous substance. w was 8.6 × 10 ³ .

Production Example 5 of Macromonomer: A mixture of 97 g of MM-5 propyl methacrylate, 3 g of 3-mercaptopropionic acid, and 200 g of toluene was heated at a temperature of 70 g under a nitrogen stream.
The solution was heated to ° C to obtain a homogeneous solution. Add 2.0 g of AIBN, 8
Reacted for hours. After cooling, the precipitate was reprecipitated in 2 l of methanol and heated under reduced pressure to a temperature of 50 ° C. to distill off the solvent. The obtained viscous substance was dissolved in 200 g of toluene, and 16 g of glycidyl methacrylate, 1.0 g of N, N-dimethyldodecyl methacrylate and 1.0 g of t-butylhydroquinone were added to the mixed solution, and the mixture was stirred at a temperature of 110 ° C. for 10 hours. This reaction solution was reprecipitated again in 21 of methanol. The w of the obtained pale yellow viscous material is
It was 6.5 × 10 ³ .

Production Example 6 of Macromonomer: MM-6 A mixed solution of 95 g of benzyl methacrylate, 5 g of thioglycolic acid and 200 g of toluene was heated to a temperature of 75 ° C. while stirring under a nitrogen stream. 1.5 g of AIBN was added and reacted for 8 hours. Next, the reaction solution was brought to a temperature of 25 ° C., and a mixed solution of 10 g of dicyclohexylcarbodiimide (abbreviated as DCC) to which 8 g of 2-hydroxyethyl methacrylate was added, 0.2 g of 4- (N, N-dimethylamino) pyridine and 50 g of methylene chloride was added. The mixture was added dropwise with stirring for 30 minutes. The reaction was further continued for 3 hours. Next, formic acid (5 ml) was added thereto, and the mixture was stirred for 1 hour. Then, the insoluble material was suction-filtered using celite, and the obtained filtrate was reprecipitated in hexane (1.5 l). The precipitated viscous matter was collected by decantation and dissolved using 200 ml of tetrahydrofuran, and a small amount of insoluble matter was filtered by suction filtration using celite in the same manner as described above. The filtrate was re-precipitated in hexane 1 again, and the deposited viscous matter was collected by decantation and dried under reduced pressure.

The w of the obtained colorless viscous substance was 4.5 × 10 ³ .

Production example 7 of macromonomer: MM-7 methyl methacrylate 40 g, ethyl acrylate 54 g,
A mixture of 6 g of 2-mercaptoethylamine, 150 g of toluene and 50 g of tetrahydrofuran was heated to a temperature of 75 ° C. while stirring under a nitrogen stream. 2.0 g of AIBN was added and reacted for 8 hours. Next, this reaction solution was brought to a temperature of 20 ° C. in a water bath, and 23 g of methacrylic anhydride was added dropwise thereto so as not to exceed a temperature of 25 ° C., followed by further stirring for 1 hour. 2,2'-
Methylenebis- (6-t-butyl-p-cresol) 0.
5 g was added, and the mixture was stirred at a temperature of 40 ° C for 3 hours. After cooling, this solution was reprecipitated in 2 l of methanol to obtain 83 g of a viscous substance. w
Was 7.5 × 10 ³ .

Production Example 8 of Macromonomer: MM-8 A mixed solution of 95 g of methyl methacrylate, 150 g of toluene and 50 g of ethanol was heated to a temperature of 75 ° C. under a nitrogen stream. 5 g of ACV was added, and the mixture was reacted for 8 hours. Next, glycidyl acrylate 15 g, N, N-dimethyldodecylamine 1.
0g and 2,2'-methylenebis- (6-t-butyl-p-
Cresol) (1.0 g) was added and the mixture was stirred at a temperature of 100 ° C. for 15 hours.
After cooling, the reaction solution was reprecipitated in 2 l of methanol to obtain 83 g of a transparent viscous substance. w was 5.3 × 10 ³ .

Macromonomer Production Examples 9 to 27: MM-9 to MM-27 In the Macromonomer Production Example 6, the same operation as in Production Example 2 was performed except that the monomers in Table 1 were used instead of propyl methacrylate. Thus, a macromonomer was produced.
The w of each macromonomer was 4 × 10 ^{3 to} 5.5 × 10 ³ .

Binder Resin Preparation Example 1: GP-1 A mixed solution of 70 g of the following compound (A-1), 30 g of macromonomer (MM-1) of Preparation Example 1 of macromonomer and 200 g of toluene was added to a temperature of 75 ° C. under a nitrogen stream. Warmed. In addition, A.
1.0 g of IBN was added and reacted for 4 hours, and 0.6 g of AIBN was further added and reacted for 4 hours.

The w of the obtained polymer was 4.5 × 10 ⁴ .

Production Example 2 of Binder Resin: GP-2 A mixed solution of 80 g of the following compound (A-2), 20 g of the macromonomer (MM-6) of Preparation Example 6 for macromonomer and 200 g of tetrahydrofuran was added to a temperature of 60 ° C. under a nitrogen stream. Warmed.
2,2'-azobisvaleronitrile (abbreviation: ABVN)
1.5 g was added and reacted for 4 hours. Further, 0.8 g of ABVN was added and reacted for 4 hours.

W of the obtained polymer was 5.0 × 10 ⁴ .

Binder Resin Production Example 3: GP-3 70 g of the following compound (A-3), Production Example 1 of macromonomer
A polymerization solution was prepared in the same manner as in Production Example 1 except that a mixed solution of 30 g of the macromonomer (MM-13) of Example 3 and 200 g of toluene was prepared. The w of the obtained polymer was 5.3 × 10 ⁴ .

Binder Resin Production Examples 4 to 10: GP-4 to GP-10 In Production Example 3, instead of 70 g of the compound (A-3) and 30 g of the macromonomer (MM-13), the respective compounds shown in Table 2 below were used. Except for using each, each polymer was produced in the same manner as in Production Example 3. W of each polymer is 4.5 × 10 ^{4 to} 6 × 10 ⁴
Met.

Example 1 Binder resin GP-1 and 10 g and [butyl methacrylate / acrylic acid (99/1) weight ratio] copolymer (weight average molecular weight 45
000) 10 g, a mixture of 100 g of zinc oxide and 300 g of toluene,
6 × 10 ³ rp in a homogenizer (manufactured by Nippon Seiki Co., Ltd.)
The mixture was dispersed at a rotation speed of m. for 10 minutes. Next, this dispersion, a back layer on one surface of woodfree paper, using a wire bar to a dry coating weight on the intermediate layer of the support an intermediate layer provided on the other side is 18 g / m ² It was applied and dried at 100 ° C. for 1 minute to prepare a lithographic printing plate precursor.

This master was immersed in a 5 mol / l monoethanolamine aqueous solution for 5 minutes, washed with water, and dried. A drop of 2 μl of distilled water was placed on this, and the contact angle with the formed water was measured with a goniometer and found to be 10 ° or less. The angle was 95 ° before the desensitization treatment. This indicates that the non-image portion of the image receiving layer of the original plate of the present invention has changed from lipophilic to hydrophilic (usually, the non-image portion does not generate printing background stain, dot stain, etc. during printing). It is necessary that the degree of conversion be 20 ° or less in contact angle with water).

Next, plate making was performed using a commercially available PPC, and the resulting plate was subjected to a desensitizing treatment under the same conditions as described above to obtain a plate for printing.

The density of the image portion of the obtained original plate was 1.0 or more, there was no background fog in the non-image portion, and the image quality of the image portion was clear.
This is an offset printing machine (Oliver manufactured by Sakurai Seisakusho Co., Ltd.)
52 type) and printed on high quality paper. Even if the number of prints exceeded 3,000, no problem was caused in the background smear of the non-image portion and the image quality of the image portion of the printed matter.

Furthermore, using the above-mentioned original plate, the environmental conditions were set to 30 ° C. and 80% pH, and the plate was made with a commercially available PPC.
The density of the image portion was 1.0 or more, there was no background fog in the non-image portion, and the image quality of the image portion was clear. When this was printed in the same manner as above, there was no problem even when 3,000 sheets were printed.

As described above, the original plate did not deteriorate the image quality by the PPC plate making even under the condition of high temperature and high humidity.

Examples 2 to 7 In Example 1, instead of the resin [1] of the present invention,
Except for using the copolymers shown in Table 3, operations were performed in the same manner as in Example 1 to prepare lithographic printing plate precursors.

This was operated in the same manner as in Example 1 to prepare an original plate. The density of the obtained master plate for offset printing is 1.2
The image quality was clear as above. Further, when the sheet was etched and printed by a printing machine, the printed matter after printing 3,000 sheets had no fog in the non-image portion and the image was clear.

Further, after the photographic material was allowed to stand under the conditions of (45 ° C., 75% RH), the same processing as described above was performed, but there was no change at all before the lapse of time.

Example 8 Binder resin GP-9,8 g, and [weight ratio of methyl methacrylate / methyl acrylate / methacrylic acid (60/29/1)]
A mixture of 32 g of a copolymer (weight average molecular weight: 55,000), 50 g of zinc oxide and 200 g of toluene was placed in a homogenizer at 6 × 10 4.
Disperse at ³ rpm for 10 minutes, then add phthalic anhydride
0.5 g was added thereto and dispersed at 1 × 10 ³ rpm for 1 minute. The dispersion thus obtained was coated on a support under the same conditions as in Example 1, dried at 100 ° C. for 30 seconds, and further heated at 110 ° C. for 1 hour to prepare a lithographic printing plate precursor.

This was made into a plate using the same apparatus as in Example 1, then subjected to an etching treatment, and printed using a printing machine. The density of the offset printing master plate obtained after plate making was 1.0 or more, and the image quality was clear. The image quality of the printed matter after printing 5,000 sheets was a clear image without background fog.

(Effects of the Invention) According to the present invention, it is possible to obtain a direct drawing type lithographic printing plate precursor having excellent suppression of generation of background stains and good printing durability.

Claims (1)

(57) [Claims] 1. A direct drawing lithographic printing plate precursor having an image receiving layer on a support, wherein the binder of the image receiving layer contains at least one of a fluorine atom and a silicon atom as a main component. A monofunctional monomer having a functional group that generates at least one of a sulfo group, a phosphono group, a carboxyl group, and a hydroxyl group by decomposition, and a compound represented by the following general formulas (IIa) and (IIb): Weight average molecular weight of 2 × 10 ^{4, wherein} a polymerizable double bond group represented by the following general formula (I) is bonded to only one terminal of a polymer main chain containing at least one of the polymer components to be obtained. A direct-printing lithographic printing plate precursor comprising at least one graft-type copolymer comprising at least the following monofunctional macromonomer. General formula (I) In the formula (I), X ₁ represents —COO—, —OCO—, CH _{2 n} OCO—,
_{CH 2 m COO -, - O} -, - SO 2 -, - CO-, -CONHCOO-, -CONHCONH- or (D ₁ represents a hydrogen atom or a hydrocarbon group; n,
m represents an integer of 1 to 4). a _1, a _2, which may be the same or different, a hydrogen atom, a cyano group, a hydrocarbon group, -COO-Z ₁ or -COO-Z ₁ via a hydrocarbon (Z ₁ are being hydrogen atom or a substituent Represents a good hydrocarbon group). General formula (IIa) General formula (IIb) In formula (IIa) or (IIb), X ₂ represents the same content as X ₁ in formula (I). R ₁ represents an aliphatic group having 1 to 18 carbon atoms or an aromatic group having 6 to 12 carbon atoms. b ₁ and b ₂ may be the same or different, and represent the same contents as a ₁ and a ₂ in the formula (I). R ₂ is -CN, -CONH ₂ or Wherein Y represents a hydrogen atom, a halogen atom, an alkoxy group or —COOZ ₂ (Z ₂ represents an alkyl group, an aralkyl group or an aryl group).