JP2012208384A - Lithographic printing plate precursor and photosensitive composition using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lithographic printing plate precursor being excellent in chemical resistance, having high printing durability even in the case of using UV ink, and giving a lithographic printing plate without development scum adhesion in developing.SOLUTION: A lithographic printing plate precursor has a recording function layer composed of at least one layer on a substrate and has an alkali-soluble resin, an infrared absorbent and a basic compound on a layer which is the same as or different from the layer composing the recording function layer, where the basic compound has an acidic functional group with a pKa of 3 to 14 and a basic functional group forming a conjugate acid with a pKa of 11 to 18.

Description

  The present invention relates to a lithographic printing plate precursor and a photosensitive composition used therefor.

Conventionally, various photosensitive compositions have been used as visible image forming and lithographic printing plate materials. In particular, the development of technology related to laser exposure and development in lithographic printing in recent years is remarkable. In particular, a solid-state laser / semiconductor laser having a light emitting region from the near infrared to the infrared can easily be obtained with a high output and a small size. These lasers are very useful as exposure light sources when directly making a plate from digital data such as a computer, and the development of a lithographic printing plate corresponding to this laser is extremely important.
The positive type lithographic printing plate precursor for an infrared laser contains an alkali-soluble binder resin and an IR dye that absorbs light and generates heat as essential components. The IR dye or the like functions as a development inhibitor that substantially lowers the solubility of the binder resin in the developer by interaction with the binder resin in the unexposed area (image area). On the other hand, in the exposed area (non-image area), the interaction between the IR dye and the binder resin is weakened by the generated heat and dissolves in an alkaline developer to form a lithographic printing plate.

One of the important performances as a positive lithographic printing plate for infrared laser is resistance to UV ink and printing peripheral chemicals. Unlike normal ink, UV ink does not contain a solvent, has high viscosity and high tackiness, and has higher polarity than normal ink. For this reason, the image area is easily affected, and the printing durability is generally lower than that in the case of normal ink. Therefore, improvement of printing durability when using UV ink (UV ink printing durability) is a major issue.
In order to solve this problem, a photosensitive composition and a lithographic printing plate precursor using a polymer containing a structural unit having a specific functional group have been proposed (see, for example, Patent Documents 1 and 2), and have chemical resistance. Has been reported to be improved. However, a lithographic printing plate to which a photosensitive composition using these polymers is added has a problem that aggregates of the photosensitive composition adhere during development (development residue adhesion).

US Pat. No. 6,475,692 European Patent Publication No. 1738900

  An object of the present invention is to provide a lithographic printing plate precursor which gives a lithographic printing plate having excellent chemical resistance, high printing durability even when UV ink is used, and no development residue adhesion during development, and a photosensitive composition used therefor Is to provide.

（上記式（I）中、Ｌ^１〜Ｌ^４は、それぞれ独立に、炭素数１〜１０の２価のアルキレン基、あるいは炭素数６〜２０の２価のアリーレン基、酸素原子、窒素原子を含む連結基、硫黄原子、単結合、またはそれらの組合せによる連結基を表す。Ａ^１〜Ａ^４は、それぞれ独立に、酸性基、あるいは水素原子、炭素数１〜２０のアルキル基、又は炭素数６〜２０のアリール基を表し、Ａ^１〜Ａ^４の少なくとも１つの基が酸性基とする。） The above-mentioned problems of the present invention have been solved by the following means of the present invention.
(1) It has a recording functional layer comprising at least one layer on a support, and an alkali-soluble resin, an infrared absorber, a basic compound, and the like are formed on the same layer or different layers of the recording functional layer. A lithographic printing plate precursor having
The lithographic printing plate precursor, wherein the basic compound has an acidic functional group having a pKa of 3 to 14 and a basic functional group forming a conjugate acid of a pKa of 11 to 18.
(2) The lithographic printing plate precursor as described in (1), wherein the basic compound is represented by the following general formula (I):

(In the above formula (I), L ^{1 to} L ⁴ each independently represents a divalent alkylene group having 1 to 10 carbon atoms, or a divalent arylene group having 6 to 20 carbon atoms, an oxygen atom, or a nitrogen atom. A ^{1 to} A ⁴ each independently represent an acidic group, a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a carbon number. Represents an aryl group of 6 to 20, and at least one group of A ^{1 to} A ⁴ is an acidic group.)

（上記式（II）中、Ｒ^１〜Ｒ^４はそれぞれ独立に、水素原子、炭素数１〜２０のアルキル基、又は炭素数６〜２０のアリール基を表す。Ｌ^５は、炭素数１〜１０の２価のアルキレン基又は炭素数６〜２０の２価のアリーレン基、酸素原子、窒素原子を含む連結基、またはそれらの組合せによる連結基を表す。Ａ^５は、酸性基を表す。） (3) The lithographic printing plate precursor as described in (1) or (2), wherein the basic compound is represented by any one of the following general formulas (II) to (V).

(In the formula ^(II), in each of R 1 to R ⁴ independently represent a hydrogen atom, the .L ⁵ represents an alkyl group, or an aryl group having 6 to 20 carbon atoms having 1 to 20 carbon atoms, 1 to carbon atoms 10 represents a divalent alkylene group, a divalent arylene group having 6 to 20 carbon atoms, a linking group containing an oxygen atom or a nitrogen atom, or a combination thereof, and A ⁵ represents an acidic group.)

（上記式(III)中、Ｒ^５〜Ｒ^７はそれぞれ独立に、水素原子、炭素数１〜２０のアルキル基、又は炭素数６〜２０のアリール基を表す。Ｌ^６は、炭素数１〜１０の２価のアルキレン基又は炭素数６〜２０の２価のアリーレン基、またはそれらの組合せによる連結基を表す。Ａ^６は、酸性基を表す。）

(In the above formula (III), R ^{5 to} R ⁷ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L ⁶ represents 1 to 1 carbon atoms. 10 represents a linking group formed of a divalent alkylene group having 10 carbon atoms, a divalent arylene group having 6 to 20 carbon atoms, or a combination thereof, and A ⁶ represents an acidic group.)

（上記式(IV)中、Ｒ⁸〜Ｒ¹⁰はそれぞれ独立に、水素原子、炭素数１〜２０のアルキル基、又は炭素数６〜２０のアリール基を表す。Ｌ^７とＬ^８とはそれぞれ独立に、炭素数１〜１０の２価のアルキレン基、炭素数６〜２０の２価のアリーレン基、酸素原子、窒素原子を含む連結基、またはそれらの組合せによる連結基を表し、互いに環を形成してもよい。Ａ^７、Ａ^８は、酸性基を表す。）

(In the above formula (IV), R ^{8 to} R ¹⁰ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L ⁷ and L ⁸ each represent Independently, it represents a divalent alkylene group having 1 to 10 carbon atoms, a divalent arylene group having 6 to 20 carbon atoms, a linking group containing an oxygen atom or a nitrogen atom, or a linking group thereof in combination. (A ⁷ and A ⁸ may represent an acidic group.)

（上記式(V)中、Ｒ¹¹〜Ｒ¹³はそれぞれ独立に、水素原子、炭素数１〜２０のアルキル基、又は炭素数６〜２０のアリール基を表す。Ｌ^９は、炭素数１〜１０の２価のアルキレン基、炭素数６〜２０の２価のアリーレン基、酸素原子、窒素原子を含む連結基、またはそれらの組合せによる連結基を表す。Ａ^９は、酸性基を表す。）

(In the above formula (V), R ^{11 to} R ¹³ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L ⁹ represents 1 to 1 carbon atoms. 10 represents a divalent alkylene group having 10 carbon atoms, a divalent arylene group having 6 to 20 carbon atoms, a linking group containing an oxygen atom or a nitrogen atom, or a combination thereof, and A ⁹ represents an acidic group.)

（上記式（I）中、Ｌ^１〜Ｌ^４は、それぞれ独立に、炭素数１〜１０の２価のアルキレン基、あるいは炭素数６〜２０の２価のアリーレン基、酸素原子、窒素原子を含む連結基、硫黄原子、単結合、またはそれらの組合せによる連結基を表す。Ａ^１〜Ａ^４は、それぞれ独立に、酸性基、あるいは水素原子、炭素数１〜２０のアルキル基、又は炭素数６〜２０のアリール基を表し、Ａ^１〜Ａ^４の少なくとも１つの基が酸性基とする。） (4) Any of (1) to (3), wherein the acidic functional group is selected from the group consisting of a sulfonamide group, a substituted sulfonamide group, a phenolic hydroxyl group, a thiophenolic thiol group, and a carboxyl group The lithographic printing plate precursor as described in 1 above.
(5) The lithographic printing plate precursor as described in any one of (1) to (4), wherein the alkali-soluble resin is polyurethane, acrylic resin, or acetal resin.
(6) The lithographic printing plate precursor as described in any one of (1) to (5), wherein the recording functionality comprises an upper layer, a lower layer, and an undercoat layer.
(7) The lithographic printing plate precursor as described in any one of (1) to (6), wherein the upper layer contains an infrared absorber.
(8) The lithographic printing plate precursor as described in any one of (1) to (7), wherein the lower layer contains an alkali-soluble resin.
(9) A photosensitive composition forming a recording functional layer disposed on a support of a lithographic printing plate precursor,
A photosensitive composition comprising at least a basic compound, wherein the basic compound has an acidic functional group having a pKa of 3 to 14 and a basic functional group forming a conjugate acid of a pKa of 11 to 18.
(10) The photosensitive composition according to claim 9, wherein the basic compound is represented by the following general formula (I).

(In the above formula (I), L ^{1 to} L ⁴ each independently represents a divalent alkylene group having 1 to 10 carbon atoms, or a divalent arylene group having 6 to 20 carbon atoms, an oxygen atom, or a nitrogen atom. A ^{1 to} A ⁴ each independently represent an acidic group, a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a carbon number. Represents an aryl group of 6 to 20, and at least one group of A ^{1 to} A ⁴ is an acidic group.)

（上記式（II）中、Ｒ^１〜Ｒ^４はそれぞれ独立に、水素原子、炭素数１〜２０のアルキル基、又は炭素数６〜２０のアリール基を表す。Ｌ^５は、炭素数１〜１０の２価のアルキレン基又は炭素数６〜２０の２価のアリーレン基、酸素原子、窒素原子を含む連結基、またはそれらの組合せによる連結基を表す。Ａ^５は、酸性基を表す。） (11) The photosensitive composition as described in (9), wherein the basic compound is represented by any one of the following general formulas (II) to (V).

(In the formula ^(II), in each of R 1 to R ⁴ independently represent a hydrogen atom, the .L ⁵ represents an alkyl group, or an aryl group having 6 to 20 carbon atoms having 1 to 20 carbon atoms, 1 to carbon atoms 10 represents a divalent alkylene group, a divalent arylene group having 6 to 20 carbon atoms, a linking group containing an oxygen atom or a nitrogen atom, or a combination thereof, and A ⁵ represents an acidic group.)

（上記式(III)中、Ｒ^５〜Ｒ^７はそれぞれ独立に、水素原子、炭素数１〜２０のアルキル基、又は炭素数６〜２０のアリール基を表す。Ｌ^６は、炭素数１〜１０の２価のアルキレン基又は炭素数６〜２０の２価のアリーレン基、またはそれらの組合せによる連結基を表す。Ａ^６は、酸性基を表す。）

(In the above formula (III), R ^{5 to} R ⁷ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L ⁶ represents 1 to 1 carbon atoms. 10 represents a linking group formed of a divalent alkylene group having 10 carbon atoms, a divalent arylene group having 6 to 20 carbon atoms, or a combination thereof, and A ⁶ represents an acidic group.)

（上記式(IV)中、Ｒ⁸〜Ｒ¹⁰はそれぞれ独立に、水素原子、炭素数１〜２０のアルキル基、又は炭素数６〜２０のアリール基を表す。Ｌ^７とＬ^８とはそれぞれ独立に、炭素数１〜１０の２価のアルキレン基、炭素数６〜２０の２価のアリーレン基、酸素原子、窒素原子を含む連結基、またはそれらの組合せによる連結基を表し、互いに環を形成してもよい。Ａ^７、Ａ^８は、酸性基を表す。）

(In the above formula (IV), R ^{8 to} R ¹⁰ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L ⁷ and L ⁸ each represent Independently, it represents a divalent alkylene group having 1 to 10 carbon atoms, a divalent arylene group having 6 to 20 carbon atoms, a linking group containing an oxygen atom or a nitrogen atom, or a linking group thereof in combination. (A ⁷ and A ⁸ may represent an acidic group.)

（上記式(V)中、Ｒ¹¹〜Ｒ¹³はそれぞれ独立に、水素原子、炭素数１〜２０のアルキル基、又は炭素数６〜２０のアリール基を表す。Ｌ^９は、炭素数１〜１０の２価のアルキレン基、炭素数６〜２０の２価のアリーレン基、酸素原子、窒素原子を含む連結基、またはそれらの組合せによる連結基を表す。Ａ^９は、酸性基を表す。）

(In the above formula (V), R ^{11 to} R ¹³ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L ⁹ represents 1 to 1 carbon atoms. 10 represents a divalent alkylene group having 10 carbon atoms, a divalent arylene group having 6 to 20 carbon atoms, a linking group containing an oxygen atom or a nitrogen atom, or a combination thereof, and A ⁹ represents an acidic group.)

  In this specification, the recording function layer means an image recording layer and other layers (typically, an undercoat layer). As a specific example, the recording function layer A can be shown as including the image recording layer 1 and the undercoat layer 3 in FIG.

According to the present invention, it is possible to provide a lithographic printing plate precursor which is excellent in abrasion resistance and chemical resistance, has a large printing durability even when UV ink is used, and gives a lithographic printing plate which does not cause stains during printing. it can.

It is sectional drawing which shows typically one embodiment of the single layer structure of the lithographic printing plate precursor of this invention. It is sectional drawing which shows typically one embodiment of the multilayer structure of the lithographic printing plate precursor of this invention.

Hereinafter, the present invention will be described in detail.
The lithographic printing plate precursor of the present invention has a recording functional layer comprising at least one layer on a support, and an alkali-soluble resin and an infrared absorber in the same layer or different layers constituting the recording functional layer And a basic compound. And the said basic compound has the acidic functional group of pKa3-14, and the basic functional group which makes the conjugate acid of pKa10-18.

The present invention is characterized in that the recording functional layer contains the basic compound that has not been applied to this type of printing plate precursor. This basic compound coexists with a relatively acidic functional group and a basic functional group, and its action simultaneously satisfies wear resistance, chemical resistance, printing durability, and suppression of stains during printing. In particular, the printing durability is considered to be highly effective for UV ink. The reason is not clear, but it is as follows when including the estimation.
That is, the above basic compound having an acidic group is highly inorganic (meaning that it contains a lot of atoms other than carbon atoms), and added to an alkali-soluble resin (binder polymer). Organicity decreases. As a result, it is considered that the durability against printing peripheral chemicals containing UV ink and organic solvent was improved. Furthermore, due to the presence of acidic groups, the solubility in an alkaline developer has also been improved at the same time as compared to the application of a compound having a basic group. Conceivable. On the other hand, with respect to the durability (printing durability) of the image portion with respect to an alkaline developer, the developability is improved by application of the basic compound. However, it is possible to apply butyral resin, polyurethane and the like, and to achieve both high developability and printing durability. Hereinafter, the present invention will be described in detail based on preferred embodiments thereof.

<Basic compound having an acidic group>
The basic compound used in the present invention has an acidic functional group whose pKa is estimated to be 3 to 14, and a basic functional group whose pKa is estimated to be 11 to 18 as a conjugate acid.
The pKa of the acidic functional group is defined as pKa in a compound in which a predetermined atom or atomic group (typically a hydrogen atom) that does not substantially participate in pKa is introduced into the bond of the substituent. The pKa of the acidic functional group may be relatively determined by the relationship with the basic functional group described later, and is preferably 3-15 lower than the latter, more preferably 4-14 lower than the latter. The pKa range of the acidic functional group is 3 to 14, but is preferably 4 to 13, and more preferably 4 to 11. The pKa here is a value calculated by ACD / ChemSketch unless otherwise specified. Or you may refer to the value published in the “Chemical Handbook for Revision 5” edited by the Chemical Society of Japan.
The definition of pKa of the conjugate acid of the basic functional group is as described above, and the range of pKa is 11 to 18, but is preferably 12 to 17, and more preferably 12 to 16.

  The basic compound having an acidic group used in the present invention is preferably one represented by the following general formula (I).

In formula (I), L ^{1 to} L ⁴ are each independently a divalent alkylene group having 1 to 10 carbon atoms (preferably 1 to 8 carbon atoms, more preferably 2 to 6 carbon atoms), carbon A divalent arylene group having 6 to 20 carbon atoms (preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms), an oxygen atom, a linking group containing a nitrogen atom, a sulfur atom, a single bond, or a combination thereof Represents a linking group. Although the connecting group containing a nitrogen atom is not particularly limited, it can be represented by -NR-, and R is preferably a hydrogen atom, an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or the like. A ^{1 to} A ⁴ are each independently an acidic group, a hydrogen atom, an alkyl group having 1 to 20 carbon atoms (preferably 2 to 10 carbon atoms, more preferably 3 to 7 carbon atoms), or 6 carbon atoms. Represents an aryl group having 20 to 20 carbon atoms (preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms), and at least one group of A ^{1 to} A ⁴ is an acidic group. The acidic group includes a sulfonamide group (pKa: 10.9), an acetyl-substituted sulfonamide group (pKa: 4.8), a phenolic hydroxyl group (pKa: 10.2), and a thiophenolic thiol group (pKa: 6. 8) or a carboxyl group (pKa: 4.8). Of the acidic functional groups, a sulfonamide group and a phenolic hydroxyl group are more preferable from the viewpoint of achieving both developability and durability.
As for the acidic functional group in the compound represented by the general formula (I), A ¹ -B (B: a predetermined atom or atomic group) is defined as a compound which is a premise for the estimation of the pKa, and B is defined as a methyl group. The pKa in the specific examples described above was described above. As for the basic functional group, the guanidine skeleton is the group, and B ¹ (B ² ) —N— (C═N—B ¹ ) —N— (B ² ) B ¹ is used as a compound for estimating this pKa. is assumed. When B ¹ and B ² are H, the compound is guanidine and the conjugate acid has a pKa of 13.3. When B ¹ is CH ₃ and B ² is H, the compound is 1,2,3-trimethylguanidine and the conjugate acid has a pKa of 13.9.

  Furthermore, the basic compound having an acidic group used in the present invention is more preferably one represented by any one of the following general formulas (II) to (V).

In the above formula (II), R ^{1 to} R ⁴ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms (preferably 2 to 10 carbon atoms, more preferably 3 to 7 carbon atoms), and the carbon number. Represents an aryl group having 6 to 20 carbon atoms (preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms). Among the alkyl groups having 1 to 20 carbon atoms, a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, and a cyclohexyl group are preferable. Among the aryl groups having 6 to 20 carbon atoms, a phenyl group, a p-tolyl group, a 1-naphthyl group, and a 2-naphthyl group are preferable. R ² and R ³ are preferably hydrogen atoms (dissociable protons), and R ³ and R ⁴ are preferably organic groups (non-dissociable groups).
L ⁵ is a divalent alkylene group having 1 to 10 carbon atoms (preferably 1 to 8 carbon atoms, more preferably 2 to 6 carbon atoms), 6 to 20 carbon atoms (preferably 6 to 15 carbon atoms, carbon A divalent arylene group, an oxygen atom, a linking group containing a nitrogen atom, or a linking group thereof in combination. Of these, a methylene group, an ethylene group, and a phenylene group are preferable.
A ⁵ represents, represents an acidic group. Preferred groups are the same as the A ^1.

In the above formula (III), R ^{5 to} R ⁷ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms (preferably 2 to 10 carbon atoms, more preferably 3 to 7 carbon atoms), and the carbon number. Represents an aryl group having 6 to 20 carbon atoms (preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms). Among the alkyl groups having 1 to 20 carbon atoms, a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, and a cyclohexyl group are preferable. Among the aryl groups having 6 to 20 carbon atoms, a phenyl group, a p-tolyl group, a 1-naphthyl group, and a 2-naphthyl group are preferable. R ⁶ is preferably a hydrogen atom (dissociable proton), and R ⁵ and R ⁷ are preferably organic groups (non-dissociable groups).
L ⁶ is a divalent alkylene group having 1 to 10 carbon atoms (preferably 1 to 8 carbon atoms, more preferably 2 to 6 carbon atoms), 6 to 20 carbon atoms (preferably 6 to 15 carbon atoms, carbon The linking group is preferably a divalent arylene group or a combination thereof. Of these, a methylene group, an ethylene group, and a phenylene group are preferable.
A ⁶ represents an acidic group. Preferred groups are the same as the A ^1.
As for the basic functional group, the isourea skeleton is the group, and B ¹ -N = (C—O—B ¹ ) —N— (B ² ) B ¹ is assumed as a compound for estimating this pKa. When B ¹ and B ² are H, the compound is isourea and the pKa of the conjugate acid is 17.3. When B ¹ is CH ₃ and B ² is H, the compound is 1,2,3-trimethylisourea and the conjugate acid has a pKa of 11.7.

In the above formula (IV), R ^{8 to} R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms (preferably 2 to 10 carbon atoms, more preferably 3 to 7 carbon atoms), and carbon number. Represents an aryl group having 6 to 20 carbon atoms (preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms). Among the alkyl groups having 1 to 20 carbon atoms, a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, and a cyclohexyl group are preferable. Among the aryl groups having 6 to 20 carbon atoms, a phenyl group, a p-tolyl group, a 1-naphthyl group, and a 2-naphthyl group are preferable. R ⁹ is preferably a hydrogen atom (dissociable proton), and R ⁸ and R ¹⁰ are preferably organic groups (non-dissociable groups).
L ⁷ and L ⁸ may form a ring with each other, a divalent alkylene group having 1 to 10 carbon atoms (preferably 1 to 8 carbon atoms, more preferably 2 to 6 carbon atoms), and 6 carbon atoms. Represents a linking group having a divalent arylene group of 20 to 20 carbon atoms (preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms), a linking group containing an oxygen atom or a nitrogen atom, or a combination thereof.
A ⁷ and A ⁸ represent an acidic group. Preferred groups are the same as the A ^1.
As for the basic functional group, the guanidine skeleton corresponds to the group, and the pKa of the conjugate acid of guanidine and 1,2,3-trimethylguanidine as the compound for estimating this pKa is the same as described in the general formula (I). is there.

In the above formula (V), R ^{11 to} R ¹³ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms (preferably 2 to 10 carbon atoms, more preferably 3 to 7 carbon atoms), and carbon number. Represents an aryl group having 6 to 20 carbon atoms (preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms). Among the alkyl groups having 1 to 20 carbon atoms, a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, and a cyclohexyl group are preferable. Among the aryl groups having 6 to 20 carbon atoms, a phenyl group, a p-tolyl group, a 1-naphthyl group, and a 2-naphthyl group are preferable. R ¹³ is preferably a hydrogen atom (dissociable proton), and R ¹¹ and R ¹² are preferably organic groups (non-dissociable group).
L ⁹ is a divalent alkylene group having 1 to 10 carbon atoms (preferably 1 to 8 carbon atoms, more preferably 2 to 6 carbon atoms), 6 to 20 carbon atoms (preferably 6 to 15 carbon atoms, carbon A divalent arylene group, an oxygen atom, a linking group containing a nitrogen atom, or a linking group thereof in combination. Of these, a methylene group, an ethylene group, and a phenylene group are preferable.
A ⁹ represents an acidic group. Preferred groups are the same as the A ^1.
For the basic functional group, the iminomethylamino skeleton corresponds to the group, and B ¹ -N = (C—B ¹ ) —N— (B ² ) B ¹ is assumed as a compound for the estimation of this pKa. When B ¹ and B ² are H, the compound is amidine and the pKa of the conjugate acid is 11.3. When B ¹ is CH ₃ and B ² is H, the compound is dimethylamidinomethane, and the conjugate acid has a pKa of 12.8.

In the present specification, when an xxx group is referred to with respect to a substituent, the xxx group may have an arbitrary substituent. In addition, when there are a plurality of groups indicated by the same symbol, they may be different or the same. When a plurality of groups are connected to form a ring, all of the plurality of groups may be connected or a part thereof may be connected.
Although the preferable aspect of the basic compound represented by general formula (I)-(V) used for this invention below is shown, this invention is not limited to this.

The basic compound having an acidic group used in the present invention is preferably one represented by the general formula (I).
The addition amount of the basic compound having an acidic group is preferably 0.01 to 50% by mass and more preferably 0.1 to 40% by mass with respect to the total solid content of the recording functional layer. . By setting it to the above lower limit or higher, sufficient chemical resistance can be obtained, and by setting it to the upper limit or lower, it is possible to develop well.
From the same viewpoint, the content of the basic compound having an acidic group is preferably 0.1 to 75% by mass, and 1 to 50% by mass with respect to 100 parts by mass of the alkali-soluble resin of the entire recording functional layer. Is more preferable.
In the present specification, the *** compound is used to mean a salt thereof, an ion thereof, and the like in addition to the compound itself. Typically, it means the compound and / or its salt.
Regarding the salt of the specific basic compound, halide ions, tetrafluoroborate ions, hexafluorophosphate ions, carboxylate ions, sulfonate ions, nitrate ions, carbonate ions, etc. are preferably used as counter ions. .

(Alkali-soluble resin (binder polymer))
In the lithographic printing plate precursor according to the invention, by containing an alkali-soluble resin, an interaction is formed between the infrared absorber and the polar group of the alkali-soluble resin, and a positive photosensitive layer is formed. The
Preferred examples of the alkali-soluble resin include polyamide resins, epoxy resins, polyacetal resins, acrylic resins, methacrylic resins, polystyrene resins, and novolac phenol resins. In addition, polyurethane, polyvinyl alcohol, polyvinyl formal, polyamide, polyester, epoxy resin, and the like can be given.
As the alkali-soluble resin when coexisting with the basic compound having an acidic group, those having a carboxylic acid group that can be neutralized by the basic compound having an acidic group are more preferable. As the main skeleton of such an alkali-soluble resin, acrylic resin, polyurethane, polyvinyl alcohol, acetal resin, polyvinyl formal, polyamide, polyester, epoxy resin and the like are used. In particular, an acrylic resin, an acetal resin, and a polyurethane are preferable from the viewpoints of image formability, printing durability, and production suitability. Among these, from the viewpoint of printing durability and production suitability, an acetal resin and polyurethane are more preferable, and polyurethane is most preferable.
In the present invention, the “acrylic resin” means (meth) acrylic acid, (meth) acrylic acid ester (alkyl ester, aryl ester, allyl ester, etc.), (meth) acrylamide, and (meth) acrylamide derivatives ( A copolymer having a (meth) acrylic acid derivative as a polymerization component. Although it does not specifically limit as a monomer unit containing a carboxylic acid group, The structure as described in [0059]-[0075] of Unexamined-Japanese-Patent No. 2002-40652 and Unexamined-Japanese-Patent No. 2005-300650 is used preferably. As the monomer unit derived from (meth) acrylic acid amide, the monomer unit derived from (meth) acrylic acid amide described in [0061] to [0084] of JP-A-2007-272134 is preferably used. A copolymer containing N-phenylmaleimide and methacrylamide as monomer units described in US Pat. No. 6,358,669 is also preferably used.
Although the preferable aspect of the acrylic resin used by this invention to coexist in the same layer with the basic group which has an acidic group is shown below, this invention is not limited to this.

なお、（ ）の右下の数字はモル比である。

The number on the lower right of () is the molar ratio.

Among the above compounds, (PA-8) to (PA-10) are particularly preferable.
In the present invention, “polyurethane” refers to a polymer produced by a condensation reaction of a compound having two or more isocyanate groups and a compound having two or more hydroxyl groups.
In the present invention, the alkali-soluble resin that coexists in the same layer as the basic compound having an acidic group is not particularly limited as long as it is a polyurethane having a carboxylic acid group, but JP-A-2003-177533 and JP-A-2004-170525. Polyurethanes having a structure described in JP-A No. 2004-239951, JP-A No. 2004-157459 and JP-A No. 2005-250158 are preferably used.
Specific examples of a macromonomer that is a polyol component suitable as a raw material for polyurethane, with respect to a preferred embodiment of the polyurethane coexisting in the same layer as the basic compound having an acidic group used in the present invention [Exemplary Compound (MM-1) to (MM-24)] is exemplified by displaying the chain transfer agent used in the production, the raw material monomer, and its addition amount (mol%) and molecular weight, but the present invention is not limited thereto.

  As a preferred specific example of the polyurethane coexisting in the same layer with the basic compound having an acidic group that can be used in the present invention, the molar ratio using PU-1 to PU-42 with the raw material monomer and the obtained specific polyurethane Of course, the polyurethane resin is not limited thereto. In addition, the number described under each following monomer name represents the molar ratio of each used monomer.

  “Acetal resin” refers to a polymer synthesized by reacting polyvinyl alcohol obtained by saponifying part or all of polyvinyl acetate with an aldehyde compound under an acidic condition (acetalization reaction). A polymer having a carboxylic acid group or the like introduced by a method of reacting a compound having a remaining hydroxy group with an acid anhydride or the like is also included. As a more preferable embodiment, the polyvinyl butyral resin into which the following carboxylic acid group is introduced is used as the coexisting compound in the same layer as the basic compound having an acidic group.

In general formula (V), the preferred ratio of each repeating unit is in the range of p / q / r / s = 50-78 mol% / 1-5 mol% / 5-28 mol% / 5-20 mol%. . R _a , R _b , R _c , R _d , R _e and R _f are each independently a monovalent substituent or a single bond which may have a substituent, and m is an integer of 0 to 1. Preferred substituents for R _a , R _b , R _c , R _d , R _e , and R _f include a hydrogen atom, an alkyl group that may have a substituent, a halogen atom, and an aryl that may have a substituent. Groups. More preferably, a straight-chain alkyl group such as a hydrogen atom, a methyl group, an ethyl group or a propyl group, an alkyl group substituted with a carboxylic acid, a halogen atom, a phenyl group or a phenyl group substituted with a carboxylic acid can be mentioned. R _c and R _d , R _e and R _f can each form a ring structure. The bond between the carbon atom to which R _c and R _e are bonded and the carbon atom to which R _d and R _f are bonded is a single bond, a double bond or an aromatic double bond, and a double bond or an aromatic two bond. In the case of a double bond, R _c —R _d , R _e —R _f , R _c —R _f , or R _e —R _d are each bonded to form a single bond.
Preferable specific examples of the carboxylic acid group-containing unit include the following examples.

  Although the preferable aspect of the acetal resin made to coexist in the same layer as the basic compound which has an acidic group used for this invention below is shown, this invention is not limited to this.

なお、（ ）の右下の数字はモル比である。

The number on the lower right of () is the molar ratio.

The molecular weight (mass average molecular weight) of the alkali-soluble resin having a carboxylic acid group that can be neutralized is preferably 5,000 to 500,000 from the viewpoint of developability and printing durability, and is preferably 10,000 to 200,000. 000 is more preferable, and 15,000 to 100,000 is most preferable.
The acid value of the alkali-soluble resin having a carboxylic acid group that can be neutralized is preferably 0.30 mmol / g to 5.00 mmol / g from the viewpoint of developability and printing durability, and is 0.80 mmol / g. It is more preferably ˜4.00 mmol / g, and most preferably 1.50 mmol / g to 3.00 mmol / g.
The addition amount (neutralization amount) of the basic compound having an acidic group to the alkali-soluble resin having a carboxylic acid group is 10 mol with respect to 100 mol% of the carboxylic acid group from the viewpoint of interlayer mixing suppression, developability, and printing durability. % To 100 mol% is preferable, 15 mol% to 80 mol% is more preferable, and 20 mol% to 60 mol% is most preferable.

  The addition amount of the alkali-soluble resin is preferably 1 to 90% by mass and more preferably 5 to 85% by mass with respect to the total solid content of the recording functional layer. By setting it as the said lower limit or more, it can develop favorable, and sufficient solvent resistance can be obtained by setting it as the said upper limit or less.

In the present invention, the term “molecular weight” means a mass average molecular weight unless otherwise specified, and the molecular weight and the degree of dispersion are values measured by the following measuring methods.
[Measurement method of molecular weight and dispersity]
Unless otherwise specified, the molecular weight and the degree of dispersion are values measured using a GPC (gel filtration chromatography) method, and the molecular weight is a weight average molecular weight in terms of polystyrene. The gel packed in the column used in the GPC method is preferably a gel having an aromatic compound as a repeating unit, and examples thereof include a gel made of a styrene-divinylbenzene copolymer. It is preferable to use 2 to 6 columns connected together. Examples of the solvent used include ether solvents such as tetrahydrofuran and amide solvents such as N-methylpyrrolidinone, but amide solvents such as N-methylpyrrolidinone are preferred. The measurement is preferably performed at a solvent flow rate in the range of 0.1 to 2 mL / min, and most preferably in the range of 0.5 to 1.5 mL / min. By performing the measurement within this range, the apparatus is not loaded and the measurement can be performed more efficiently. The measurement temperature is preferably 10 to 50 ° C, most preferably 20 to 40 ° C. The column and carrier to be used can be appropriately selected according to the physical properties of the polymer compound to be measured.

(Infrared absorber)
The infrared absorber is not particularly limited as long as it is a dye that absorbs infrared light and generates heat, and various dyes known as infrared absorbers can be used.
As the infrared absorber that can be used in the present invention, commercially available dyes and known ones described in literature (for example, “Dye Handbook” edited by Organic Synthetic Chemistry Association, published in 1970) can be used. Specific examples include azo dyes, metal complex azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, and cyanine dyes. In the present invention, among these dyes, those that absorb at least infrared light or near-infrared light are preferable because they are suitable for use in lasers that emit infrared light or near-infrared light, and cyanine dyes are particularly preferred. preferable.

Examples of the dye that absorbs at least infrared light or near infrared light include, for example, JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-. Cyanine dyes described in each publication such as 78787, methine dyes described in each publication such as JP-A-58-173696, JP-A-58-181690, JP-A-58-194595, Japanese Laid-Open Patent Publication Nos. 58-112793, 58-224793, 59-48187, 59-73996, 60-52940, 60-63744, etc. Naphthoquinone dyes described in JP-A-58-112792, squarylium dyes described in JP-A-58-112792, cyanine dyes described in British Patent 434,875, etc. Can.
Further, near-infrared absorption sensitizers described in US Pat. No. 5,156,938 are also preferably used as dyes, and substituted arylbenzoates described in US Pat. No. 3,881,924 are also preferred. (Thio) pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645 (U.S. Pat. No. 4,327,169), JP-A-58-181051, JP-A-58-2220143, 59-41363, 59-84248, 59-84249, 59-146063, 59-146061, and pyrium compounds described in JP-A-59-216146. Cyanine dye, pentamethine thiopyrylium salt described in U.S. Pat. No. 4,283,475, etc., and Japanese Patent Publication Nos. 5-13514 and 5-19702 Pyrylium compounds disclosed in distribution is, as commercially available products, Epolight III-178 of Eporin Co., Epolight III-130, Epolight III-125 and the like are particularly preferably used.
Another particularly preferable example of the dye is a near-infrared absorbing dye described as formulas (I) and (II) in US Pat. No. 4,756,993.

  Particularly preferred among these dyes are cyanine dyes, phthalocyanine dyes, oxonol dyes, squarylium dyes, pyrylium salts, thiopyrylium dyes, and nickel thiolate complexes. Furthermore, the cyanine dye represented by the following general formula (a) is most preferable because it gives high polymerization activity and is excellent in stability and economy when used in the upper layer in the present invention.

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

In the above formula, Xa ^- has Za described later ^- 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 ²¹ and R ²² each independently represent a hydrocarbon group having 1 to 12 carbon atoms. In view of storage stability of the photosensitive layer coating solution, R ²¹ and R ²² are preferably hydrocarbon groups having 2 or more carbon atoms, and R ²¹ and R ²² 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 ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ 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. Furthermore, Za ^- represents a counter anion. However, Za ⁻ is not necessary when the cyanine dye represented by formula (a) has an anionic substituent in its structure and charge neutralization is not necessary. Preferred Za ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, a hexagonal salt, in view of the storage stability of the photosensitive layer coating solution. Fluorophosphate ion and aryl sulfonate ion.

Specific examples of the cyanine dye represented by the general formula (a) that can be suitably used include paragraph numbers [0017] to [0019] of JP-A No. 2001-133969 and paragraph numbers of JP-A No. 2002-40638. [0012] to [0038] and paragraphs [0012] to [0023] described in JP-A No. 2002-23360.
The cyanine dye A shown below is particularly preferable as the infrared absorber.

  The addition amount when the infrared absorber is added is preferably 0.01 to 50% by mass, more preferably 0.1 to 30% by mass, based on the total solid content of the layer. It is especially preferable that it is -30 mass%. When the addition amount is 0.01% by mass or more, high sensitivity is obtained, and when it is 50% by mass or less, the uniformity of the layer is good and the durability of the layer is excellent.

  The infrared absorber may be added to the same layer as other components or may be added to another layer. When added to a layer different from other components, it is added to the layer adjacent to the layer containing a substance that is thermally decomposable and substantially reduces the solubility of the binder resin when not decomposed. It is preferable to do this. The infrared absorber is preferably contained in the same layer as the binder resin, but may be contained in another layer.

(Other ingredients)
The image recording layer may contain other additives depending on the purpose.
As other components, the following components such as an acid generator, an acid proliferation agent, a development accelerator, and a surfactant can be used.
Acid generator The image recording layer preferably contains an acid generator from the viewpoint of improving sensitivity.
In this invention, an acid generator is a compound which generate | occur | produces an acid with light or a heat | fever, and points out the compound which decomposes | disassembles and generate | occur | produces an acid by infrared irradiation or a heating of 100 degreeC or more. The acid generated is preferably a strong acid having a pKa of 2 or less, such as sulfonic acid and hydrochloric acid. The acid generated from the acid generator functions as a catalyst, the chemical bond in the acid-decomposable group is cleaved to become an acid group, and the solubility in the upper alkaline aqueous solution is further improved.

Examples of the acid generator suitably used in the present invention include onium salts such as iodonium salts, sulfonium salts, phosphonium salts, and diazonium salts. Specific examples include compounds described in US Pat. No. 4,708,925 and JP-A-7-20629. In particular, iodonium salts, sulfonium salts, and diazonium salts having a sulfonate ion as a counter ion are preferable. Examples of the diazonium salt include diazonium compounds described in U.S. Pat. No. 3,867,147, diazonium compounds described in U.S. Pat. No. 2,632,703, and JP-A-1-102456 and JP-A-1-102457. The diazo resin described in the publication is also preferable. Also preferred are benzyl sulfonates described in US Pat. No. 5,135,838 and US Pat. No. 5,200,544. Furthermore, active sulfonic acid esters and disulfonyl compounds described in JP-A-2-100054, JP-A-2-100055 and Japanese Patent Application No. 8-9444 are also preferable. In addition, haloalkyl-substituted S-triazines described in JP-A-7-271029 are also preferable.
Further, the compound described as “acid precursor” in JP-A-8-220552 or “(a) a compound capable of generating an acid upon irradiation with active light” in JP-A-9-171254 And the like can be applied as the acid generator of the present invention.
Among these, from the viewpoint of sensitivity and stability, it is preferable to use an onium salt compound as the acid generator. Hereinafter, the onium salt compound will be described.
Examples of the onium salt compound that can be suitably used in the present invention include compounds known as compounds that generate an acid by being decomposed by thermal energy generated from an infrared absorber upon exposure to infrared light. Examples of the onium salt compound suitable for the present invention include known thermal polymerization initiators and compounds having an onium salt structure described below having a bond with small bond dissociation energy from the viewpoint of sensitivity.
Examples of the onium salt suitably used in the present invention include known diazonium salts, iodonium salts, sulfonium salts, ammonium salts, pyridinium salts, azinium salts, and the like. Among them, triarylsulfonium or diaryliodonium sulfonic acid Salt, carboxylate, BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ^{− and the} like are preferable.
In addition, compounds described as examples of radical polymerization initiators in paragraphs [0036] to [0045] of JP-A-2008-195018 can be suitably used as the acid generator in the present invention.
Specific examples of the azinium salt compound include compounds described in paragraph numbers [0047] to [0056] of JP-A-2008-195018.
The N—O bond described in JP-A-63-138345, JP-A-63-142345, JP-A-63-142346, JP-A-63-143537, and JP-B-46-42363 is also disclosed. A group of compounds having the above is also suitably used as the acid generator in the present invention.
When the acid generator is added to the upper layer, the preferable addition amount is 0.01 to 50% by mass, preferably 0.1 to 40% by mass, more preferably 0.5 to 30% by mass with respect to the total solid content of the upper layer. % Range. When the addition amount is in the above range, an improvement in sensitivity, which is an effect of addition of an acid generator, is observed, and generation of a residual film in a non-image area is suppressed.

-Acid proliferating agent As another component, an acid proliferating agent may be added.
The acid proliferating agent in the present invention is a compound substituted with a relatively strong acid residue, and is a compound that is easily eliminated in the presence of an acid catalyst to newly generate an acid. That is, it decomposes by an acid catalyst reaction and generates an acid (hereinafter referred to as ZOH in the general formula) again. One or more acids are increased in one reaction, and the sensitivity is dramatically improved by increasing the acid concentration at an accelerated rate as the reaction proceeds. The strength of the generated acid is 3 or less as an acid dissociation constant (pKa), and preferably 2 or less. If the acid is weaker than this, an acid-catalyzed elimination reaction cannot be caused.
Examples of the acid used for such an acid catalyst include dichloroacetic acid, trichloroacetic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, and phenylsulfonic acid.

  Examples of the acid proliferating agent include WO95 / 29968, WO98 / 24000, JP-A-8-305262, JP-A-9-34106, JP-A-8-248561, JP-A-8-503082, and US Pat. No. 5,445. No. 9,917, JP-A-8-503081, US Pat. No. 5,534,393, US Pat. No. 5,395,736, US Pat. No. 5,741,630, US Pat. No. 5,334,489 , U.S. Patent No. 5,582,956, U.S. Patent No. 5,578,424, U.S. Patent No. 5,453,345, U.S. Patent No. 5,445,917, European Patent No. 665,960, EP 757,628, EP 665,961, U.S. Pat. No. 5,667,943, JP-A-10-1598, etc. It is possible to have.

  Preferable specific examples of the acid proliferating agent in the present invention include, for example, compounds described in paragraph numbers [0056] to [0067] of JP-A No. 2001-66765.

  The amount of these acid proliferating agents added to the image recording layer is 0.01 to 20% by mass, preferably 0.01 to 10% by mass, more preferably 0.1 to 10% by mass in terms of solid content. It is in the range of 5% by mass. When the amount of the acid proliferating agent is within the above range, the effect of adding the acid proliferating agent is sufficiently obtained, the sensitivity is improved, the decrease in the film strength of the image area is suppressed, and the excellent film resulting from the specific polyurethane Strength is maintained.

-Development accelerator For the purpose of improving the sensitivity, acid anhydrides, phenols, and organic acids may be added to the image recording layer.
As the acid anhydrides, cyclic acid anhydrides are preferable. Specific examples of the cyclic acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, and hexahydro anhydride described in US Pat. No. 4,115,128. Phthalic acid, 3,6-endooxytetrahydrophthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be used. Examples of acyclic acid anhydrides include acetic anhydride.
Examples of phenols include bisphenol A, 2,2′-bishydroxysulfone, p-nitrophenol, p-ethoxyphenol, 2,4,4′-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4- Examples include hydroxybenzophenone, 4,4 ′, 4 ″ -trihydroxytriphenylmethane, 4,4 ′, 3 ″, 4 ″ -tetrahydroxy-3,5,3 ′, 5′-tetramethyltriphenylmethane. .
Examples of the organic acids are described in JP-A-60-88942, JP-A-2-96755, and the like. Specifically, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, Ethyl sulfuric acid, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid, p-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 4-cyclohexene Examples include -1,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, ascorbic acid and the like.
The proportion of the acid anhydride, phenols and organic acids in the total solid content of the lower or upper layer is preferably 0.05 to 20% by mass, more preferably 0.1 to 15% by mass, and 0.1 to 10%. Mass% is particularly preferred.

Surfactant The image recording layer is described in Japanese Patent Application Laid-Open No. 62-251740 and Japanese Patent Application Laid-Open No. 3-208514 in order to improve the coating property and to expand the processing stability against the development conditions. Nonionic surfactants such as those described above, amphoteric surfactants such as those described in JP-A-59-121044 and JP-A-4-13149, JP-A-62-170950, JP-A-11 A fluorine-containing monomer copolymer as described in JP-A No. 288093 and JP-A No. 2003-57820 can be added.
Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether and the like.
Specific examples of amphoteric activators include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N-tetradecyl-N, N-betaine. Type (for example, trade name “Amorgen K” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).
The proportion of the surfactant in the total solid content of the image recording layer is preferably 0.01 to 15% by mass, more preferably 0.01 to 5% by mass, and still more preferably 0.05 to 2.0% by mass.

Print-out agent / colorant A print-out agent for obtaining a visible image immediately after heating by exposure or a dye or pigment as an image colorant can be added to the image recording layer.
As a printing-out agent and a coloring agent, it describes in detail in paragraph number [0122]-[0123] of Unexamined-Japanese-Patent No. 2009-229917, for example, The compound described here is applicable also to this invention.
These dyes are preferably added at a rate of 0.01 to 10% by mass, more preferably at a rate of 0.1 to 3% by mass, based on the total solid content of the image recording layer.

-Plasticizer A plasticizer may be added to the image recording layer in order to impart flexibility and the like of the coating film. For example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid These oligomers and polymers are used.
These plasticizers are preferably added at a rate of 0.5 to 10% by mass, and more preferably at a rate of 1.0 to 5% by mass, based on the total solid content of the image recording layer.

-Wax agent A compound that lowers the static friction coefficient of the surface can be added to the image recording layer layer for the purpose of imparting resistance to scratches. Specifically, as described in US Pat. No. 6,117,913, JP-A No. 2003-149799, JP-A No. 2003-302750, or JP-A No. 2004-12770, A compound having an ester of a long-chain alkyl carboxylic acid can be exemplified.
The addition amount is preferably 0.1 to 10% by mass and more preferably 0.5 to 5% by mass in the image recording layer.

<Formation of planographic printing plate precursor>
The lithographic printing plate precursor according to the invention is formed by applying a photosensitive composition (image recording layer coating solution) prepared by dissolving the above components in a solvent onto a support described later. If necessary, an undercoat layer described later may be applied between the support and the image recording layer. In the present specification, the term “composition” is not limited to a liquid composition as long as a plurality of components are substantially uniformly mixed, and includes a paste-like composition and a powder-like composition. In a broad sense, it means to include a recording functional layer after molding or a layer constituting the recording functional layer.
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-butyrolactone, and toluene. It is not limited to. These solvents are used alone or in combination.
Among these coating liquids, a composition containing the basic compound having an acidic group is used as the photosensitive composition of the present invention. 0.01-50 mass% is preferable, as for the addition amount of the basic compound which has an acidic group with respect to solid content of the photosensitive composition of this invention, 0.01-40 mass% is more preferable, 0.05-40 mass % Is more preferable. By setting it to the lower limit value or more, sufficient chemical resistance can be obtained, and by setting the upper limit value or less, it is possible to develop well.
The concentration of each component (total solid content including additives) of the image recording layer coating solution in the solvent is preferably 1 to 50% by mass. Further, the coating amount (solid content) of the image recording layer on the support obtained after coating and drying varies depending on the application, but generally 0.5 to 5.0 g / m ² is preferable. As the coating amount decreases, the apparent sensitivity increases, but the film characteristics of the image recording layer decrease.

The lithographic printing plate precursor according to the invention may take the form of an image recording layer having not only a single layer structure but also a multilayer structure. 1 and 2 are cross-sectional views schematically showing the layer structure of a lithographic printing plate having a single layer structure and a multilayer structure. In the single-layer structure shown in FIG. 1, the image recording layer 1 is provided on a support 4 having an undercoat layer 3. On the other hand, when taking a multi-layer structure, a lower layer (lower image recording layer) 12 and an upper layer (upper image recording layer) 11 are provided in this order on a support 4 having an undercoat layer 3 as shown in FIG. As the lower layer 12, an image recording layer containing an infrared absorber and a binder resin is preferably provided, and the upper layer 11 is preferably provided on the surface thereof. The upper layer 11 may be a positive photosensitive image recording layer or a non-photosensitive layer. In the case of a positive photosensitive image recording layer, the binder may be used as an alkali-soluble resin. It is preferable to use a resin.
When the image recording layer of the lithographic printing plate precursor according to the present invention has a multi-layer structure, the coating amount is the coating amount after drying of the lower layer provided on the side close to the support at the time of securing printing durability and development. From the viewpoint of suppressing the occurrence of residual film in the layer, it is preferably in the range of 0.5 to 1.5 g / m ² , more preferably 0.7 to 1.2 g / m ² . The coating amount after the upper layer of the drying is preferably in a range of 0.05 to 1.0 g / ^{m 2,} more preferably in the range of 0.07~0.7g / ^{m 2.}

  The coating method is not particularly limited, and examples thereof include known coating methods such as bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

(Support)
As the support used in the lithographic printing plate precursor according to the present invention, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate having particularly good dimensional stability and relatively low cost is particularly preferable. A suitable aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, and may be a plastic film on which aluminum is laminated or vapor-deposited. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is preferably 10% by mass or less.
Particularly suitable aluminum in the present invention is pure aluminum, but completely pure aluminum is difficult to produce in the refining technique, and may contain slightly different elements.
Thus, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate made of a publicly known material can be appropriately used. The thickness of the aluminum plate used in the present invention is preferably 0.1 to 0.6 mm, more preferably 0.15 to 0.4 mm, and particularly preferably 0.2 to 0.3 mm. preferable.

Such an aluminum plate may be subjected to a surface treatment such as a roughening treatment or an anodizing treatment as necessary. As for the surface treatment of the aluminum support, for example, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution, or the like, as described in detail in [0167] to [0169] of JP2009-175195A, surface A surface roughening treatment, an anodizing treatment, or the like is appropriately performed.
The anodized aluminum surface is subjected to a hydrophilic treatment as necessary.
Examples of the hydrophilization treatment include an alkali metal silicate (for example, sodium silicate aqueous solution) method, a method of treating with potassium zirconate fluoride or polyvinylphosphonic acid as disclosed in [0169] of 2009-175195. Used.

(Undercoat layer)
In the present invention, an undercoat layer can be provided between the support and the image forming layer as necessary. The undercoat layer may contain a basic compound having the acidic group.
As an undercoat layer component, various organic compounds are used. For example, phosphonic acids having amino groups such as carboxymethylcellulose and dextrin, organic phosphonic acids, organic phosphoric acids, organic phosphinic acids, amino acids, and hydroxy groups. Preferred examples thereof include hydrochlorides of amines and the like. These undercoat layer components may be used singly or in combination of two or more. Details of the compounds used for the undercoat layer and the method for forming the undercoat layer are described in paragraphs [0171] to [0172] of JP2009-175195A, and these descriptions are also applied to the present invention. The
The coverage of the organic undercoat layer is preferably 2 to 200 mg / ^{m 2,} and more preferably 5 to 100 mg / ^{m 2.} When the coating amount is in the above range, sufficient printing durability can be obtained.

(Back coat layer)
A back coat layer is provided on the back surface of the support of the lithographic printing plate precursor according to the invention, if necessary. Such a back coat layer comprises a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174. A coating layer is preferably used. Among these coating layers, 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 are available at a low price. The coating layer of the metal oxide obtained therefrom is particularly preferable because of its excellent developer resistance.

<Plate making method of lithographic printing plate>
The lithographic printing plate precursor produced as described above is exposed imagewise and then subjected to development treatment to produce a lithographic printing plate. That is, in a lithographic printing plate precursor exposed to a desired image quality, the solubility of an exposed area in an alkaline developer is improved, and is removed by development to form a non-image area, and the remaining unexposed area image recording layer Is the image part of a lithographic printing plate.

<Exposure process>
The plate making method of a lithographic printing plate includes an exposure step of exposing the infrared sensitive positive lithographic printing plate precursor of the present invention imagewise.
The actinic ray light source used for image exposure of the lithographic printing plate precursor according to the invention is preferably a light source having an emission wavelength in the near infrared to infrared region, and more preferably a solid laser or a semiconductor laser. Among these, it is particularly preferable that the image exposure is performed by a solid laser or a semiconductor laser that emits infrared light having a wavelength of 750 to 1,400 nm.
The laser output is preferably 100 mW or more, and a multi-beam laser device is preferably used in order to shorten the exposure time. The exposure time per pixel is preferably within 20 μsec.
The energy applied to the planographic printing plate precursor is preferably 10 to 300 mJ / cm ² . When it is in the above range, curing can proceed sufficiently, laser ablation can be suppressed, and damage to the image can be prevented.

  The exposure can be performed by overlapping the light beams of the light sources. Overlap means that the sub-scanning pitch width is smaller than the beam diameter. The overlap can be expressed quantitatively by FWHM / sub-scanning pitch width (overlap coefficient), for example, when the beam diameter is expressed by the full width at half maximum (FWHM) of the beam intensity. The overlap coefficient is preferably 0.1 or more.

  The scanning method of the light source of the exposure apparatus is not particularly limited, and a cylindrical outer surface scanning method, a cylindrical inner surface scanning method, a planar scanning method, or the like can be used. The channel of the light source may be a single channel or a multi-channel, but in the case of a cylindrical outer surface system, a multi-channel is preferably used.

<Development process>
-Developer The plate making method of a lithographic printing plate using the lithographic printing plate precursor according to the invention includes a developing step of developing using an alkaline aqueous solution. The alkaline aqueous solution (hereinafter also referred to as “developer”) used in the development step is preferably an alkaline aqueous solution having a pH of 8.5 to 10.8, and more preferably pH 9.0 to 10.0. . The developer preferably contains a surfactant, and more preferably contains at least an anionic surfactant or a nonionic surfactant. Surfactant contributes to the improvement of processability.
As the surfactant used in the developer, any of anionic, nonionic, cationic and amphoteric surfactants can be used. As described above, anionic and nonionic surfactants are used. Agents are preferred.
The anionic surfactant used in the developer of the present invention is not particularly limited, but fatty acid salts, abietic acid salts, hydroxyalkanesulfonic acid salts, alkanesulfonic acid salts, dialkylsulfosuccinic acid salts, linear alkylbenzenesulfonic acid salts. Branched alkylbenzene sulfonates, alkyl naphthalene sulfonates, alkyl diphenyl ether (di) sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine Sodium, N-alkylsulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated castor oil, sulfated beef tallow oil, sulfate esters of fatty acid alkyl esters, alkyl sulfates Ester salts, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene styrylphenyl ether sulfates, alkyl phosphate esters, polyoxyethylene alkyl ether phosphates Salt, polyoxyethylene alkylphenyl ether phosphate ester salt, styrene-maleic anhydride copolymer partial saponification products, olefin-maleic anhydride copolymer partial saponification products, naphthalene sulfonate formalin condensates, etc. Can be mentioned. Among these, alkylbenzene sulfonates, alkyl naphthalene sulfonates, and alkyl diphenyl ether (di) sulfonates are particularly preferably used.

  The cationic surfactant used in the developer is not particularly limited, and conventionally known cationic surfactants can be used. Examples thereof include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.

  The nonionic surfactant used in the developer is not particularly limited, but a polyethylene glycol type higher alcohol ethylene oxide adduct, alkylphenol ethylene oxide adduct, alkyl naphthol ethylene oxide adduct, phenol ethylene oxide adduct, naphthol ethylene Oxide adduct, fatty acid ethylene oxide adduct, polyhydric alcohol fatty acid ester ethylene oxide adduct, higher alkylamine ethylene oxide adduct, fatty acid amide ethylene oxide adduct, fat and oil ethylene oxide adduct, polypropylene glycol ethylene oxide adduct, dimethyl Siloxane-ethylene oxide block copolymer, dimethylsiloxane- (propylene oxide-ethylene oxide) Examples include lock copolymers, fatty acid esters of polyhydric alcohol glycerol, fatty acid esters of pentaerythritol, fatty acid esters of sorbitol and sorbitan, fatty acid esters of sucrose, alkyl ethers of polyhydric alcohols, fatty acid amides of alkanolamines, etc. It is done. Among these, those having an aromatic ring and an ethylene oxide chain are preferable, and an alkyl-substituted or unsubstituted phenol ethylene oxide adduct or an alkyl-substituted or unsubstituted naphthol ethylene oxide adduct is more preferable.

  The zwitterionic surfactant used in the developer is not particularly limited, and examples thereof include amine oxides such as alkyldimethylamine oxide, betaines such as alkylbetaine, and amino acids such as alkylamino fatty acid sodium. In particular, alkyldimethylamine oxide which may have a substituent, alkylcarboxybetaine which may have a substituent, and alkylsulfobetaine which may have a substituent are preferably used. Specific examples of these include those described in JP-A-2008-203359 [0255] to [0278], JP-A-2008-276166 [0028] to [0052], and the like.

  Moreover, from the viewpoint of stable solubility or turbidity in water, the HLB value is preferably 6 or more, and more preferably 8 or more.

As the surfactant used in the developer, anionic surfactants and nonionic surfactants are preferable, anionic surfactants containing sulfonic acid or sulfonates, and nonions having an aromatic ring and an ethylene oxide chain Surfactants are particularly preferred.
Surfactants can be used alone or in combination.
The content of the surfactant in the developer is preferably from 0.01 to 10% by mass, and more preferably from 0.01 to 5% by mass.

  In order to maintain the developer at pH 6 to 13.5, the presence of carbonate ions and hydrogen carbonate ions as buffering agents can suppress pH fluctuations even when the developer is used for a long period of time. It is possible to suppress development deterioration and development residue generation. In order to allow carbonate ions and hydrogen carbonate ions to be present in the developer, carbonate and hydrogen carbonate may be added to the developer, or by adjusting the pH after adding carbonate or bicarbonate, Ions and bicarbonate ions may be generated. The carbonate and bicarbonate are not particularly limited, but are preferably alkali metal salts. Examples of the alkali metal include lithium, sodium, and potassium, and sodium is particularly preferable. These may be used alone or in combination of two or more.

  The total amount of carbonate and bicarbonate is preferably 0.3 to 20% by mass, more preferably 0.5 to 10% by mass, and particularly preferably 1 to 5% by mass with respect to the total mass of the developer. When the total amount is 0.3% by mass or more, developability and processing capacity do not decrease, and when it is 20% by mass or less, it becomes difficult to form precipitates and crystals. It becomes difficult to gel and does not interfere with waste liquid treatment.

Further, for the purpose of assisting the fine adjustment of the alkali concentration and the dissolution of the non-image area photosensitive layer, another alkali agent such as an organic alkali agent may be supplementarily used together. Examples of the organic alkali agent include monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, Examples thereof include diisopropanolamine, ethyleneimine, ethylenediamine, pyridine, tetramethylammonium hydroxide and the like. These other alkaline agents are used alone or in combination of two or more.
In addition to the above, the developer may contain a wetting agent, preservative, chelate compound, antifoaming agent, organic acid, organic solvent, inorganic acid, inorganic salt, and the like. However, when a water-soluble polymer compound is added, the plate surface tends to become sticky especially when the developer is fatigued, so it is preferable not to add it.

  As the wetting agent, ethylene glycol, propylene glycol, triethylene glycol, butylene glycol, hexylene glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, diglycerin and the like are preferably used. The wetting agent may be used alone or in combination of two or more. The wetting agent is preferably used in an amount of 0.1 to 5% by mass relative to the total weight of the developer.

  Preservatives include phenol or derivatives thereof, formalin, imidazole derivatives, sodium dehydroacetate, 4-isothiazolin-3-one derivatives, benzoisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, benztriazole derivatives Amiding anidine derivatives, quaternary ammonium salts, pyridine, quinoline, guanidine and other derivatives, diazines, triazole derivatives, oxazoles, oxazine derivatives, nitrobromoalcohol-based 2-bromo-2-nitropropane-1,3diols, 1 1,1-dibromo-1-nitro-2-ethanol, 1,1-dibromo-1-nitro-2-propanol and the like can be preferably used. It is preferable to use two or more kinds of preservatives in combination so as to be effective against various molds and sterilization. The addition amount of the preservative is an amount that exhibits a stable effect on bacteria, molds, yeasts, etc., and varies depending on the types of bacteria, molds, yeasts, but is 0% relative to the total weight of the developer. The range of 0.01 to 4% by mass is preferable.

  Examples of the chelate compound include ethylenediaminetetraacetic acid, potassium salt thereof, sodium salt thereof; diethylenetriaminepentaacetic acid, potassium salt thereof, sodium salt thereof; triethylenetetraminehexaacetic acid, potassium salt thereof, sodium salt thereof, hydroxyethylethylenediaminetriacetic acid Nitrilotriacetic acid, sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, potassium salt, sodium salt; aminotri (methylenephosphonic acid), potassium salt, sodium salt And organic phosphonic acids such as phosphonoalkanetricarboxylic acids. An organic amine salt is also effective in place of the sodium salt and potassium salt of the chelating agent. A chelating agent is selected that is stably present in the developer composition and does not impair the printability. The addition amount is preferably 0.001 to 1.0% by mass with respect to the total weight of the developer.

  As the antifoaming agent, a general silicone-based self-emulsifying type, emulsifying type, or nonionic compound can be used, and a compound having an HLB value of 5 or less is preferable. Silicone defoamers are preferred. Among them, emulsification dispersion type and solubilization can be used. The content of the antifoaming agent is preferably in the range of 0.001 to 1.0% by mass with respect to the total weight of the developer.

  Examples of organic acids include citric acid, acetic acid, succinic acid, malonic acid, salicylic acid, caprylic acid, tartaric acid, malic acid, lactic acid, levulinic acid, p-toluenesulfonic acid, xylenesulfonic acid, phytic acid, and organic phosphonic acid. . The organic acid can also be used in the form of its alkali metal salt or ammonium salt. The content of the organic acid is preferably 0.01 to 0.5% by mass with respect to the total weight of the developer.

  Examples of the organic solvent include aliphatic hydrocarbons (hexane, heptane, “Isopar E, H, G” (trade name, manufactured by Esso Chemical Co., Ltd.), gasoline, kerosene, etc.), aromatic hydrocarbons, and the like. (Toluene, xylene, etc.), halogenated hydrocarbons (methylene dichloride, ethylene dichloride, trichlene, monochlorobenzene, etc.) and polar solvents.

  Polar solvents include alcohols (methanol, ethanol, propanol, isopropanol, benzyl alcohol, ethylene glycol monomethyl ether, 2-ethoxyethanol, etc.), ketones (methyl ethyl ketone, cyclohexanone, etc.), esters (ethyl acetate, methyl lactate, propylene) Glycol monomethyl ether acetate, etc.) and others (triethyl phosphate, tricresyl phosphate, N-phenylethanolamine, N-phenyldiethanolamine, etc.).

  When the organic solvent is insoluble in water, it can be used after being solubilized in water using a surfactant or the like. When the developer contains an organic solvent, the concentration of the solvent is preferably less than 40% by mass from the viewpoint of safety and flammability.

  Examples of inorganic acids and inorganic salts include phosphoric acid, metaphosphoric acid, primary ammonium phosphate, secondary ammonium phosphate, primary sodium phosphate, secondary sodium phosphate, primary potassium phosphate, secondary potassium phosphate, Examples include sodium tripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate, magnesium nitrate, sodium nitrate, potassium nitrate, ammonium nitrate, sodium sulfate, potassium sulfate, ammonium sulfate, sodium sulfite, ammonium sulfite, sodium hydrogen sulfate, nickel sulfate and the like. The content of the inorganic salt is preferably 0.01 to 0.5% by mass with respect to the total weight of the developer.

-Development processing Although there will be no restriction | limiting in particular if the temperature of image development is developable, It is preferable that it is 60 degrees C or less, and it is more preferable that it is 15-40 degreeC. In the development processing using an automatic developing machine, the developing solution may be fatigued depending on the processing amount. Therefore, the processing capability may be restored using a replenishing solution or a fresh developing solution. An example of development and post-development processing is a method in which alkali development is performed, alkali is removed in a post-water washing step, gumming is performed in a gumming step, and drying is performed in a drying step. As another example, a method in which pre-water washing, development and gumming are simultaneously performed by using an aqueous solution containing carbonate ions, hydrogen carbonate ions and a surfactant can be preferably exemplified. Therefore, the pre-water washing step is not particularly required, and it is preferable to perform the drying step after performing pre-water washing, development and gumming in one bath only by using one liquid. After development, it is preferable to dry after removing excess developer using a squeeze roller or the like.

  The development process can be preferably carried out by an automatic processor equipped with a rubbing member. As an automatic processor, for example, an automatic processor described in JP-A-2-220061 and JP-A-60-59351, which performs a rubbing process while conveying a lithographic printing plate precursor after image exposure, or a cylinder Examples thereof include an automatic processor described in US Pat. Nos. 5,148,746 and 5,568,768 and British Patent No. 2,297,719, which rubs the lithographic printing plate precursor after image exposure set above while rotating a cylinder. Among these, an automatic processor using a rotating brush roll as the rubbing member is particularly preferable.

The rotating brush roll can be appropriately selected in consideration of the difficulty of scratching the image portion and the strength of the waist of the lithographic printing plate precursor. As the rotating brush roll, a known one formed by planting a brush material on a plastic or metal roll can be used. For example, a metal or plastic in which brush materials are implanted in a row, as described in JP-A-58-159533, JP-A-3-100554, or JP-A-62-167253 A brush roll in which the groove mold material is radially wound around a plastic or metal roll as a core without any gap can be used.
Examples of brush materials include plastic fibers (for example, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6.6 and nylon 6.10, polyacrylics such as polyacrylonitrile and poly (meth) acrylate). , Polyolefin synthetic fibers such as polypropylene and polystyrene). For example, fibers having a hair diameter of 20 to 400 μm and a hair length of 5 to 30 mm can be preferably used.
The outer diameter of the rotating brush roll is preferably 30 to 200 mm, and the peripheral speed at the tip of the brush rubbing the plate surface is preferably 0.1 to 5 m / sec. It is preferable to use a plurality of rotating brush rolls.

  The rotating direction of the rotating brush roll may be the same or opposite to the conveying direction of the lithographic printing plate precursor. However, when two or more rotating brush rolls are used, at least one rotating brush roll is used. It is preferred that the rotating brush rolls rotate in the same direction and at least one rotating brush roll rotates in the opposite direction. This further ensures the removal of the photosensitive layer in the non-image area. It is also effective to swing the rotating brush roll in the direction of the rotation axis of the brush roll.

It is preferable to provide a drying step continuously or discontinuously after the development step. Drying is performed by hot air, infrared rays, far infrared rays, or the like.
As an automatic processor suitably used in the production of a lithographic printing plate using the lithographic printing plate precursor according to the present invention, an apparatus having a developing unit and a drying unit is used. Then, development and gumming are carried out, and then dried in a drying section to obtain a lithographic printing plate.

Further, for the purpose of improving printing durability, the developed printing plate can be heated under very strong conditions. The heating temperature is usually in the range of 200 to 500 ° C. If the temperature is low, sufficient image reinforcing action cannot be obtained. If the temperature is too high, problems such as deterioration of the support and thermal decomposition of the image area may occur.
The lithographic printing plate obtained in this way is applied to an offset printing machine and is suitably used for printing a large number of sheets.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not restrict | limited to a following example.
<Synthesis of a basic compound having an acidic group>
(Synthesis Example 1: II-9)
6.31 g of diisopropylcarbodiimide was added to 13.2 g of isopropyl alcohol, and 10.0 g of 4- (2-aminoethyl) benzenesulfonamide was added over 5 minutes. The suspension was stirred at 80 ° C. for 3 hours. After cooling to room temperature, 30 g of diisopropyl ether was added, and the resulting white solid (II-9) was obtained by filtration. After vacuum drying (40 ° C., 1 hour), II-9 obtained was 15.8 g (yield 97%).
(Synthesis Example 2: II-10)
6.31 g of diisopropylcarbodiimide was added to 13.2 g of isopropyl alcohol, and 6.90 g of 2- (4-hydroxyphenyl) ethylamine was added over 5 minutes. The suspension was stirred at 80 ° C. for 3 hours. After cooling to room temperature, 30 g of diisopropyl ether was added, and the resulting white solid (II-10) was collected by filtration. After vacuum drying (40 ° C., 1 hour), II-10 obtained was 11.5 g (yield 88%).

<Example 1, comparative example 1>
(Production of support)
A JIS A 1050 aluminum plate having a thickness of 0.3 mm was grained with a rotating nylon brush using a pumice-water suspension as an abrasive. The surface roughness (centerline average roughness) at this time was 0.5 μm. After washing with water, a 10% sodium hydroxide aqueous solution was immersed in a solution warmed to 70 ° C., and etching was performed so that the amount of aluminum dissolved was 6 g / m ³ . After washing with water, it was neutralized by immersing in a 30% nitric acid aqueous solution for 1 minute and thoroughly washed with water. Then, electrolytic surface roughening was performed in a 0.7% nitric acid aqueous solution for 20 seconds using a rectangular wave alternating waveform voltage having an anode voltage of 13 volts and a cathode voltage of 6 volts. After dipping to wash the surface, it was washed with water. 20% on the roughened aluminum sheet
A porous anodized film was formed using direct current in a sulfuric acid aqueous solution. Electrolysis was performed at a current density of 5 A / dm ² , and the electrolysis time was adjusted to prepare a substrate having an anodic oxide film with a mass of 4.0 g / m ^{2 on} the surface. This substrate was treated for 10 seconds in a vapor chamber saturated at 100 ° C. and 1 atm to prepare a substrate (a) having a sealing rate of 60%. Substrate (a) is 2.5 mass% sodium silicate
After surface hydrophilization by treatment with an aqueous solution at 30 ° C. for 10 seconds, the following undercoat liquid 1 was applied, and the coating film was dried at 80 ° C. for 15 seconds to obtain a lithographic printing plate support [A]. The coating amount of the coating film after drying was 15 mg / m ² .

[Undercoat liquid 1]
-0.3 g of the following copolymer having a molecular weight of 28,000
・ Methanol 100g
・ Water 1g

[Formation of recording layer]
After applying the photosensitive solution I having the following composition to the obtained undercoated support [A] with a wire bar, it is dried in a drying oven at 150 ° C. for 40 seconds to obtain a coating amount of 1.3 g / m ^2. Thus, a lower layer was provided. After providing the lower layer, the coating liquid II having the following composition was applied with a wire bar to provide the upper layer. After coating, drying was performed at 150 ° C. for 40 seconds to obtain a photosensitive lithographic printing plate precursor for infrared laser in which the total coating amount of the lower layer and the upper layer was 1.7 g / m ² .
(Photosensitive solution I)
・ 3.5g binder polymer listed in Table 1
-Basic compound having acidic group described in Table 1 Addition amount described in Table 1-Dye with 6-hydroxy-β-naphthalenesulfonic acid as the counter anion of ethyl violet 0.15 g
・ Bisphenolsulfone 0.3g
・ Tetrahydrophthalic acid 0.4g
・ Fluorine surfactant (Megafac F-780, trade name,
Dainippon Ink & Chemicals, Inc.) 0.02g
・ Methyl ethyl ketone 30g
・ Propylene glycol monomethyl ether 15g
・ Γ-Butyrolactone 15g

(Photosensitive solution II)
・ Novolak resin 0.68g
(M-cresol / p-cresol / phenol = 3/2/5, Mw 8,000)
・ Infrared absorber (cyanine dye A) 0.045g
・ Fluorine surfactant (Megafac F-780, trade name,
Dainippon Ink & Chemicals, Inc.) 0.03g
・ Methyl ethyl ketone 15.0g
-1-methoxy-2-propanol 30.0g

[Evaluation of printing durability]
A test pattern was drawn on the lithographic printing plate precursor in the form of an image with a Trend setter (trade name) manufactured by Creo at a beam intensity of 9 w and a drum rotation speed of 150 rpm. Thereafter, a PS processor LP940H (trade name) manufactured by Fuji Film Co., Ltd. charged with a developer DT-2 (trade name) manufactured by Fuji Film Co., Ltd. (diluted to a conductivity of 43 mS / cm) was used. Development was performed at a development temperature of 30 ° C. and a development time of 12 seconds. This was continuously printed using a printing press Lislon (trade name) manufactured by Komori Corporation. At this time, the number of sheets that can be printed while maintaining a sufficient ink density was measured visually to evaluate the printing durability. The printing durability was shown as a relative value when the printing durability of the comparative example (sample 101) was 1.0. As the test pattern, a solid image (entire image portion) of 2 cm × 2 cm was used. According to the visual evaluation of the printed matter, the number of scumming or missing in the printing portion was determined as the number of finished prints.

[Evaluation of UV ink printing durability]
A test pattern was drawn on the lithographic printing plate precursor in the form of an image with a Trend setter (trade name) manufactured by Creo at a beam intensity of 9 w and a drum rotation speed of 150 rpm. Thereafter, a PS processor LP940H (trade name) manufactured by Fuji Film Co., Ltd. charged with developer DT-2 (trade name) manufactured by Fuji Film Co., Ltd. (diluted to a conductivity of 43 mS / cm) was used. Development was performed at a development temperature of 30 ° C. and a development time of 12 seconds. This was continuously printed using a UV ink (Best Cure 161, trade name, manufactured by Toka Dye Co., Ltd.) with a printing press (Mitsubishi Dia, 1F-2 (trade name)). At this time, the UV ink printing durability was evaluated in the same manner as the printing durability evaluation described above.

[Development residue evaluation]
The lithographic printing plate obtained by exposure and development in the same manner as in the evaluation of printing durability was further immersed in a developing bath charged with distilled water for 20 seconds, and the plate surface of the lithographic printing plate was visually observed. "◎" if there is no deposit and no residue in the developing bath, "○" if there is no deposit, but if there is a fine development residue in the developing bath, there is no deposit The case where a large development residue was observed in the developing bath was evaluated as “Δ”, and the case where a colored component (development residue) was clearly attached was evaluated as “×”.

[Evaluation of chemical resistance]
The lithographic printing plate precursors of the examples were exposed, developed and printed in the same manner as in the evaluation of printing durability. At this time, every time 5,000 sheets were printed, a process of wiping the printing plate with a cleaner (manufactured by Fujifilm, multi-cleaner) was added to evaluate chemical resistance. When the printing durability at this time is 95% to 100% of the above-mentioned printing number, 枚 数 is 80% to 95%, △ is 60 to 80%, and 60% or less. X. Even when a process of wiping the printing plate with a cleaner is added, the smaller the change in the number of printing sheets, the better the chemical resistance.
The results are shown in Table 1 below.

The comparative basic compound used in the samples c104 to c113 of the comparative examples is a compound having the following structure, and has an acidic functional group and basic functional group of pKa shown in Table 2.

As is apparent from the results of Table 1, in the examples according to the present invention using the basic compound having an acidic group, UV ink printing durability, development residue, and chemical resistance are improved at the same time. I understand.

<Example 2, comparative example 2>
(Production of support)
In the same manner as in Example 1, the undercoat liquid 2 was used instead of the undercoat liquid 1 to prepare a support [C].
[Undercoat liquid 2]
-0.3 g of the following copolymer having a molecular weight of 28,000
-Basic compounds having acidic groups listed in Table 3 Addition amounts listed in Table 3-Methanol 100 g
・ Water 1g

[Formation of recording layer]
Using the obtained undercoated support [C], a photosensitive lithographic printing plate precursor for infrared laser was obtained using the following photosensitizers I and II in the same manner as in Example 1.

(Photosensitive solution I)
・ 3.5g binder polymer listed in Table 3
0.15 g of a dye in which the counter anion of ethyl violet is 6-hydroxy-β-naphthalenesulfonic acid
・ Bisphenolsulfone 0.3g
・ Tetrahydrophthalic acid 0.4g
・ Fluorine surfactant (Megafac F-780, trade name,
Dainippon Ink & Chemicals, Inc.) 0.02g
・ Methyl ethyl ketone 30g
・ Propylene glycol monomethyl ether 15g
・ Γ-Butyrolactone 15g

(Photosensitive solution II)
・ Novolak resin 0.68g
(M-cresol / p-cresol / phenol = 3/2/5, Mw 8,000)
・ Infrared absorber (cyanine dye A) 0.045g
・ Fluorine surfactant (Megafac F-780, trade name,
Dainippon Ink & Chemicals, Inc.) 0.03g
・ Methyl ethyl ketone 15.0g
-1-methoxy-2-propanol 30.0g

  Table 3 below shows the results obtained by evaluating the obtained lithographic printing plate precursors under the same conditions as in Example 1.

As is apparent from the results in Table 3, UV ink printing durability, development residue, and chemical resistance are also improved in an embodiment according to the present invention in which a basic compound having an acidic group is added to the undercoat layer. I understand that

DESCRIPTION OF SYMBOLS 1 Image recording layer 3 Undercoat layer 4 Support body 11 Upper layer 12 Lower layer 10, 20 Planographic printing plate precursor A Recording functional layer

Claims (11)

A lithographic plate having a recording functional layer comprising at least one layer on a support, and having an alkali-soluble resin, an infrared absorber, and a basic compound in the same layer or different layers of the recording functional layer A printing plate precursor,
The lithographic printing plate precursor, wherein the basic compound has an acidic functional group having a pKa of 3 to 14 and a basic functional group forming a conjugate acid of a pKa of 11 to 18. The lithographic printing plate precursor according to claim 1, wherein the basic compound is represented by the following general formula (I).

(In the above formula (I), L ^{1 to} L ⁴ each independently represents a divalent alkylene group having 1 to 10 carbon atoms, or a divalent arylene group having 6 to 20 carbon atoms, an oxygen atom, or a nitrogen atom. A ^{1 to} A ⁴ each independently represent an acidic group, a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a carbon number. Represents an aryl group of 6 to 20, and at least one group of A ^{1 to} A ⁴ is an acidic group.) The lithographic printing plate precursor as claimed in claim 1 or 2, wherein the basic compound is represented by any one of the following formulas (II) to (V).

(In the formula ^(II), in each of R 1 to R ⁴ independently represent a hydrogen atom, the .L ⁵ represents an alkyl group, or an aryl group having 6 to 20 carbon atoms having 1 to 20 carbon atoms, 1 to carbon atoms 10 represents a divalent alkylene group, a divalent arylene group having 6 to 20 carbon atoms, a linking group containing an oxygen atom or a nitrogen atom, or a combination thereof, and A ⁵ represents an acidic group.)

(In the above formula (III), R ^{5 to} R ⁷ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L ⁶ represents 1 to 1 carbon atoms. 10 represents a linking group formed of a divalent alkylene group having 10 carbon atoms, a divalent arylene group having 6 to 20 carbon atoms, or a combination thereof, and A ⁶ represents an acidic group.)

(In the above formula (IV), R ^{8 to} R ¹⁰ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L ⁷ and L ⁸ each represent Independently, it represents a divalent alkylene group having 1 to 10 carbon atoms, a divalent arylene group having 6 to 20 carbon atoms, a linking group containing an oxygen atom or a nitrogen atom, or a linking group thereof in combination. (A ⁷ and A ⁸ may represent an acidic group.)

(In the above formula (V), R ^{11 to} R ¹³ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L ⁹ represents 1 to 1 carbon atoms. 10 represents a divalent alkylene group having 10 carbon atoms, a divalent arylene group having 6 to 20 carbon atoms, a linking group containing an oxygen atom or a nitrogen atom, or a combination thereof, and A ⁹ represents an acidic group.)   The acidic functional group is selected from the group consisting of a sulfonamido group, a substituted sulfonamido group, a phenolic hydroxyl group, a thiophenolic thiol group, and a carboxyl group. Lithographic printing plate precursor.   The lithographic printing plate precursor as claimed in any one of claims 1 to 4, wherein the alkali-soluble resin is polyurethane, acrylic resin, or acetal resin.   6. The lithographic printing plate precursor as claimed in claim 1, wherein the recording functionality comprises an upper layer, a lower layer, and an undercoat layer.   The lithographic printing plate precursor as claimed in any one of claims 1 to 6, wherein the upper layer contains an infrared absorber.   The lithographic printing plate precursor as claimed in any one of claims 1 to 7, wherein the lower layer contains an alkali-soluble resin. A photosensitive composition forming a recording functional layer disposed on a lithographic printing plate precursor support,
A photosensitive composition comprising at least a basic compound, wherein the basic compound has an acidic functional group having a pKa of 3 to 14 and a basic functional group forming a conjugate acid of a pKa of 11 to 18. The photosensitive composition according to claim 9, wherein the basic compound is represented by the following general formula (I).

(In the above formula (I), L ^{1 to} L ⁴ each independently represents a divalent alkylene group having 1 to 10 carbon atoms, or a divalent arylene group having 6 to 20 carbon atoms, an oxygen atom, or a nitrogen atom. A ^{1 to} A ⁴ each independently represent an acidic group, a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a carbon number. Represents an aryl group of 6 to 20, and at least one group of A ^{1 to} A ⁴ is an acidic group.) The photosensitive composition according to claim 9, wherein the basic compound is represented by any one of the following general formulas (II) to (V).

(In the formula ^(II), in each of R 1 to R ⁴ independently represent a hydrogen atom, the .L ⁵ represents an alkyl group, or an aryl group having 6 to 20 carbon atoms having 1 to 20 carbon atoms, 1 to carbon atoms 10 represents a divalent alkylene group, a divalent arylene group having 6 to 20 carbon atoms, a linking group containing an oxygen atom or a nitrogen atom, or a combination thereof, and A ⁵ represents an acidic group.)

(In the above formula (III), R ^{5 to} R ⁷ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L ⁶ represents 1 to 1 carbon atoms. 10 represents a linking group formed of a divalent alkylene group having 10 carbon atoms, a divalent arylene group having 6 to 20 carbon atoms, or a combination thereof, and A ⁶ represents an acidic group.)

(In the above formula (IV), R ^{8 to} R ¹⁰ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L ⁷ and L ⁸ each represent Independently, it represents a divalent alkylene group having 1 to 10 carbon atoms, a divalent arylene group having 6 to 20 carbon atoms, a linking group containing an oxygen atom or a nitrogen atom, or a linking group thereof in combination. (A ⁷ and A ⁸ may represent an acidic group.)

(In the above formula (V), R ^{11 to} R ¹³ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L ⁹ represents 1 to 1 carbon atoms. 10 represents a divalent alkylene group having 10 carbon atoms, a divalent arylene group having 6 to 20 carbon atoms, a linking group containing an oxygen atom or a nitrogen atom, a single bond, or a combination thereof, and A ⁹ represents an acidic group. To express.)

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