JP6661567B2 - Positive photosensitive resin composition, positive lithographic printing plate precursor, and method of preparing lithographic printing plate - Google Patents

Description

  The present disclosure relates to a positive photosensitive resin composition, a positive planographic printing plate precursor, and a method for producing a planographic printing plate.

Conventionally, various photosensitive compositions have been used as a visible image forming material or a lithographic printing plate material. In particular, the development of lasers in recent years in the field of lithographic printing has been remarkable, and solid-state lasers or semiconductor lasers having a light emitting region from near infrared to infrared have become readily available in high-power and small-sized ones. ing. In the field of lithographic printing, these lasers are very useful as an exposure light source when directly making a plate from digital data of a computer or the like.
The positive type lithographic printing plate precursor for an infrared laser contains, as essential components, an alkali-soluble resin and an infrared absorbing agent (for example, an infrared absorbing dye (IR dye)) that absorbs light and generates heat. In the unexposed area (image area), the IR dye or the like acts as a development inhibitor that substantially lowers the solubility of the resin in a developing solution due to interaction with the resin, and in the exposed area (non-image area) The interaction between the IR dye or the like and the resin is weakened by the heat, and the resin dissolves in a developer to form a lithographic printing plate.
As conventional planographic printing plate precursors, those described in Patent Documents 1 to 3 are known.

  Patent Literature 1 discloses an image having, on a support, at least an image forming layer containing (A) a water-insoluble and alkali-soluble polymer compound, (B) a photothermal conversion agent, and (C) a specific sulfonamide compound. A forming material is described.

  Patent Document 2 contains at least (A) an infrared absorbing dye that is soluble in an organic solvent and alkaline water, and (B) a polymer compound that is insoluble in water and soluble in alkaline water. Is described.

  Patent Document 3 has a recording layer on a support which contains (A) an infrared absorbing agent in which a plurality of infrared absorbing chromophores having an acid group are connected to each other by a covalent bond, and is capable of forming an image by irradiation with infrared light. A lithographic printing plate precursor is described.

JP 2004-126048 A JP 2000-267265 A JP-A-2005-249878

The performance required of a positive type lithographic printing plate precursor includes, for example, chemical resistance to a plate cleaner or the like used during printing, inking property of an ink used for printing (hereinafter, referred to as “lithographic printing plate”). Simply referred to as “ink-injection property”).
Here, in the positive type lithographic printing plate, the chemical resistance obtained by lowering the solubility of the image area by the agent such as the plate cleaner and the ink adhesion obtained by improving the affinity for the ink as the agent. Meat is an incompatible property, and it is considered difficult to achieve both.

  The problem to be solved by the embodiment according to the present disclosure is to provide a positive photosensitive resin composition and a positive lithographic printing plate, which can provide a lithographic printing plate having excellent chemical resistance and ink inking property. An object of the present invention is to provide a method for producing an original plate and a lithographic printing plate having excellent chemical resistance and ink deposition.

Means for solving the above problems include the following aspects.
<1> A positive photosensitive resin composition containing a compound having a molecular weight of 5,000 or less represented by Formula I, Formula II or Formula III, an alkali-soluble resin, and an infrared absorber.

In Formula I, R ¹ represents a monovalent organic group, R ² represents a hydrogen atom or a monovalent organic group, and at least one of R ¹ and R ² contains an oxyalkylene group and is included in Formula I. The structure represented by SO ₂ NH— is one.
In Formula II, R ³ each independently represents a monovalent organic group, R ⁴ represents an n-valent organic group, at least one of R ³ and R ⁴ contains an oxyalkylene group, and n represents 2 to 4 And the number of structures represented by —SO ₂ NH— in Formula II is the same as n.
In Formula III, R ⁵ each independently represents a hydrogen atom or a monovalent organic group, R ⁶ represents an m-valent organic group, and at least one of R ⁵ and R ⁶ contains an oxyalkylene group; represents an integer of 2 to 4, the number of the structure represented by _-SO 2 NH- contained in the formula III is equal to the m.
<2> The positive type according to <1>, wherein the oxyalkylene group contained in the compound having a molecular weight of 5,000 or less represented by Formula I, Formula II or Formula III is a group represented by Formula IV below. Photosensitive resin composition.

In the formula IV, R ⁷ each independently represents an alkylene group having 2 to 6 carbon atoms, and n1 represents an integer of 1 or more.
<3> The positive photosensitive resin composition according to <2>, wherein the group represented by the above formula IV is a group represented by the following formula V.

In Formula V, R ^{8 to} R ¹¹ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and n1 represents an integer of 1 or more.
<4> The positive photosensitive resin composition according to any one of <1> to <3>, wherein R ¹ , R ^3, or R ⁶ contains an aromatic ring structure.
<5> A positive planographic printing plate precursor having an image recording layer containing the positive photosensitive resin composition according to any one of <1> to <4> on a support having a hydrophilic surface.
<6> An image recording layer having a lower layer and an upper layer in this order on a support having the hydrophilic surface, wherein the positive photosensitive resin composition is contained in at least one of the lower layer and the upper layer. 5> The positive-working lithographic printing plate precursor described in <5>.
<7> The positive lithographic printing plate precursor according to <5> or <6>, further comprising an undercoat layer between the support having the hydrophilic surface and the image recording layer.
<8> An exposure step of image-exposing the positive type lithographic printing plate precursor according to any one of <5> to <7>, and exposing the exposed positive type lithographic printing plate precursor to pH 8.5 to pH 13.5. A development step of developing using an alkaline aqueous solution of the above in this order.

  According to the embodiment of the present disclosure, a positive-type photosensitive resin composition and a positive-type lithographic printing plate precursor that can provide a lithographic printing plate with excellent chemical resistance and ink inking property of the resulting lithographic printing plate, and Provided is a method for producing a lithographic printing plate having excellent chemical resistance and excellent ink deposition.

Hereinafter, the content of the present disclosure will be described in detail. The description of the components described below may be made based on typical embodiments of the present disclosure, but the present disclosure is not limited to such embodiments.
In the present disclosure, “to” indicating a numerical range is used to mean that the numerical values described before and after it are included as the lower limit and the upper limit.
Further, in the notation of a group (atomic group) in the present disclosure, the notation of not indicating substituted or unsubstituted includes not only a group having no substituent but also a group having a substituent. For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
In the present disclosure, “mass%” and “wt%” have the same meaning, and “mass part” and “part by weight” have the same meaning.
In the present disclosure, the term “step” is included in the term as well as an independent step, even if it cannot be clearly distinguished from other steps as long as the intended purpose of the step is achieved.
Note that, in the present disclosure, a combination of preferred embodiments is a more preferred embodiment.

  In the present disclosure, unless otherwise specified, the molecular weight of the polymer component is defined as a weight average molecular weight (Mw) or a number in terms of polystyrene measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent. It is an average molecular weight (Mn).

(Positive photosensitive resin composition)
The positive photosensitive resin composition according to the present disclosure includes a compound having a molecular weight of 5,000 or less (hereinafter, also referred to as a “specific compound”) represented by Formula I, Formula II, or Formula III, an alkali-soluble resin, and Contains an infrared absorber.

As described above, in the lithographic printing plate, the chemical resistance and the ink deposition property are considered to be contradictory properties.
Here, as a result of intensive studies, the present inventors have found that, according to the positive photosensitive resin composition according to the present disclosure, a lithographic printing plate excellent in chemical resistance and ink adhesion can be obtained.
The detailed mechanism by which the above effect is obtained is unknown, but is presumed as follows.
A lithographic printing plate using the positive photosensitive resin composition according to the present disclosure is considered to have excellent chemical resistance due to strong interaction between a sulfonamide group contained in a specific compound and an alkali-soluble resin.
Further, it is considered that the oxyalkylene group contained in the specific compound has high affinity with the printing ink, so that the ink deposition property is improved.

Furthermore, the present inventors have found that a lithographic printing plate using the positive photosensitive resin composition according to the present disclosure is excellent in printing durability. This is presumed to be due to the strong interaction described above.
In addition, the present inventors have found that a lithographic printing plate using the positive photosensitive resin composition according to the present disclosure has excellent developability. In the image recording layer of a positive-working lithographic printing plate precursor using the positive-working photosensitive resin composition according to the present disclosure, a sulfonamide group showing high alkali solubility and a specific compound having a highly hydrophilic oxyalkylene group are developed. It is presumed that this is because the permeability of the liquid is improved.
In addition, the present inventors have found that a lithographic printing plate using the positive photosensitive resin composition according to the present disclosure is also excellent in suppressing residual colors. The residual color means that the image recording layer slightly remains on the support after the development processing. It is presumed that the suppression of the residual color is also due to the improvement in the permeability described above.
Hereinafter, details of each component contained in the positive photosensitive resin composition according to the present disclosure will be described.

<Specific compound>
The positive photosensitive resin composition according to the present disclosure contains a compound represented by Formula I, Formula II or Formula III and having a molecular weight of 5,000 or less.
From the viewpoints of developability and printing durability of the lithographic printing plate, it is preferable to contain a compound represented by Formula II or Formula III.

In Formula I, R ¹ represents a monovalent organic group, R ² represents a hydrogen atom or a monovalent organic group, and at least one of R ¹ and R ² contains an oxyalkylene group and is included in Formula I. The structure represented by SO ₂ NH— is one.
In Formula II, R ³ each independently represents a monovalent organic group, R ⁴ represents an n-valent organic group, at least one of R ³ and R ⁴ contains an oxyalkylene group, and n represents 2 to 4 And the number of structures represented by —SO ₂ NH— in Formula II is the same as n.
In Formula III, R ⁵ each independently represents a hydrogen atom or a monovalent organic group, R ⁶ represents an m-valent organic group, and at least one of R ⁵ and R ⁶ contains an oxyalkylene group; represents an integer of 2 to 4, the number of the structure represented by _-SO 2 NH- contained in the formula III is equal to the m.

  The oxyalkylene group contained in the specific compound is preferably a group represented by the following formula IV, and more preferably a group represented by the following formula V, from the viewpoints of developability and ink adhesion.

In the formula IV, R ⁷ each independently represents an alkylene group having 2 to 6 carbon atoms, and n1 represents an integer of 1 or more.
In Formula IV, R ⁷ is preferably each independently an alkylene group having 2 to 3 carbon atoms, more preferably an ethylene group or an isopropylene group.
In the formula IV, n1 is preferably an integer of 1 to 20, more preferably 1 to 10.

  The group represented by the above formula IV is preferably a group represented by the following formula V.

In Formula V, R ^{8 to} R ¹¹ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and n1 represents an integer of 1 or more.
In Formula V, R ^{8 to} R ¹¹ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and a hydrogen atom or a methyl group is preferable. Preferably, R ^{8 to} R ¹¹ are all hydrogen atoms, or one of R ^{8 to} R ¹¹ is a methyl group, and the other three are hydrogen atoms.
In Formula V, n1 has the same meaning as n1 in Formula IV, and the preferred embodiment is also the same.

  Further, the compound represented by the formula I, the formula II or the formula III preferably contains an aromatic ring structure from the viewpoint of the printing durability of the resulting lithographic printing plate, and includes a benzene ring structure, a naphthalene ring structure or a compound described later. It preferably contains a cyclic structure.

[Compound represented by Formula I]
-R ¹ a preferred embodiment -
In Formula I, R ¹ is preferably a group containing an alkyl group, an aryl group, or an oxyalkylene group, and more preferably an aryl group.
The alkyl group is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and still more preferably an alkyl group having 1 to 4 carbon atoms. Further, the alkyl group may be linear or branched, and may have a ring structure.
The alkyl group may have a substituent, and examples of the substituent include an aryl group having 6 to 20 carbon atoms, a group obtained by removing one hydrogen atom from a camphor ring, and a halogen atom.
The aryl group is preferably an aryl group having 6 to 20 carbon atoms, more preferably a phenyl group or a naphthyl group, and further preferably a phenyl group.
The alkyl group may have a substituent, and examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and a halogen atom.
The oxyalkylene group in the group containing the oxyalkylene group is preferably a group represented by the above formula IV, and more preferably a group represented by the above formula V.

  Further, the group containing the oxyalkylene group is preferably a group represented by the following formula OA-1.

In Formula OA-1, R ^x2 represents an alkylene group or an arylene group, R ⁷ each independently represents an alkylene group having 2 to 6 carbon atoms, R ^x1 represents a hydrogen atom or an alkyl group, and n is 1 or more. Represents an integer, and * represents a binding site to another structure.
In Formula OA-1, R ^x2 is preferably an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 20 carbon atoms, preferably an alkylene group having 1 to 4 carbon atoms, a phenylene group or a naphthylene group, and more preferably a methylene group. preferable. Further, in the above R ^x2 , the terminal bonded to the O atom in Formula OA-1 may have a structure represented by —C (＝ O) —.
In the formula OA-1, ^{R 7} has the same meaning as ^{R 7} in Formula IV, preferred embodiments are also the same.
In Formula OA-1, R ^x1 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom or a methyl group.
In the formula OA-1, n is preferably an integer of 1 to 20, more preferably 1 to 10.

-R ² of the preferred embodiment -
In Formula I, R ² is preferably a monovalent organic group, more preferably a group containing an alkyl group, an aryl group or an oxyalkylene group, and more preferably a group containing an oxyalkylene group.
The alkyl group and the aryl group have the same meanings as the alkyl group and the aryl group in R ¹ described above, and the preferred embodiments are also the same.
The oxyalkylene group contained in the group containing the oxyalkylene group is preferably a group represented by the above formula IV, and more preferably a group represented by the above formula V.
As the monovalent group containing the oxyalkylene group, a group represented by the above formula OA-1 is preferable.

-Preferred embodiment of the compound represented by Formula I-
The compound represented by the formula I has a molecular weight (weight average molecular weight when having a distribution) of 5,000 or less, preferably 3,000 or less, and more preferably 1,000 or less.

  The compound represented by the formula I is obtained, for example, by reacting a sulfonic acid halide compound represented by the following formula IA with a monofunctional amine compound represented by the following formula IB.

In the above formula I-A and formula I-B, ^{R 1} and ^{R 2} have the same meanings as ^{R 1} and ^{R 2} in the formula I, preferable embodiments thereof are also the same.
In the above formula IA, X represents a halogen atom, preferably a chlorine atom.

  Specific examples of the compound represented by Formula I include, but are not limited to, the following compounds. In addition, in the following specific examples, the parenthesized subscripts representing the oxyalkylene units indicate the number of repetitions of the oxyalkylene units.

[Compound represented by Formula II]
-R ³ of the preferred embodiment -
In Formula II, R ³ is independently preferably a group containing an alkyl group, an aryl group, or an oxyalkylene group, and more preferably an aryl group.
A plurality of R ³ may be different from each other, but are preferably the same from the viewpoint of synthesis suitability.
The alkyl group is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and still more preferably an alkyl group having 1 to 4 carbon atoms. Further, the alkyl group may be linear or branched, and may have a ring structure.
The alkyl group may have a substituent, and examples of the substituent include an aryl group having 6 to 20 carbon atoms, a group obtained by removing one hydrogen atom from a camphor ring, and a halogen atom.
The aryl group is preferably an aryl group having 6 to 20 carbon atoms, more preferably a phenyl group or a naphthyl group, and further preferably a phenyl group.
The alkyl group may have a substituent, and examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and a halogen atom.
The oxyalkylene group contained in the group containing the oxyalkylene group is preferably a group represented by the above formula IV, and more preferably a group represented by the above formula V.
As the monovalent group containing the oxyalkylene group, a group represented by the above formula OA-1 is preferable.

-R ⁴ of the preferred embodiment -
In Formula II, R ⁴ is preferably a group containing a hydrocarbon group, a triphenyleneamino group, or an oxyalkylene group.
As the hydrocarbon group, a group obtained by removing n hydrogen atoms from an aliphatic hydrocarbon having 2 to 10 carbon atoms, or a group obtained by removing n hydrogen atoms from an aromatic ring having 6 to 20 carbon atoms is preferable, A group obtained by removing n hydrogen atoms from an alkane having 2 to 4 carbon atoms or a group obtained by removing n hydrogen atoms from a benzene ring is more preferable.
The hydrocarbon group may have a substituent, and examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and a halogen atom.
The oxyalkylene group contained in the group containing the oxyalkylene group is preferably a group represented by the above formula IV, and more preferably a group represented by the above formula V.

  Further, the group containing the oxyalkylene group is preferably a group represented by the following formula OA-2 or OA-3.

In Formula OA-2, R ^x4 represents an (m2 + 1) -valent organic group, R ⁷ each independently represents an alkylene group having 2 to 6 carbon atoms, R ^x3 represents a hydrogen atom or an alkyl group, and n2 represents M2 represents an integer of 2 to 4, and * independently represents a binding site to another structure.
In Formula OA-3, R ^x5 represents an m3 valent organic group, R ⁷ each independently represents an alkylene group having 2 to 6 carbon atoms, n3 each independently represents an integer of 0 or more, and m3 In n3, at least one represents an integer of 1 or more, m3 represents an integer of 2 to 4, and * each independently represents a binding site to another structure.

In Formula OA-2, R ^x4 is preferably a (m2 + 1) -valent hydrocarbon group, and a group obtained by removing (m2 + 1) hydrogen atoms from an aliphatic hydrocarbon having 2 to 10 carbon atoms, or a group having 6 to 20 carbon atoms. A group obtained by removing (m2 + 1) hydrogen atoms from an aromatic ring of the above, a group obtained by removing (m2 + 1) hydrogen atoms from an aliphatic hydrocarbon having 2 to 4 carbon atoms, or (m2 + 1) from an benzene ring Is more preferably a group excluding a hydrogen atom.
In the formula OA-2, ^{R 7} has the same meaning as ^{R 7} in Formula IV, preferred embodiments are also the same.
In Formula OA-2, R ^x3 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom or a methyl group.
In Formula OA-2, n2 is preferably an integer of 1 to 20, and more preferably an integer of 1 to 10.
In the formula OA-2, m2 is preferably an integer of 2 to 3.

In Formula OA-3, R ^x5 is preferably an m3 valent hydrocarbon group, and a group obtained by removing m3 hydrogen atoms from an aliphatic hydrocarbon having 2 to 10 carbon atoms or an aromatic ring having 6 to 20 carbon atoms A group excluding m3 hydrogen atoms is preferable, and a group excluding m3 hydrogen atoms from an aliphatic hydrocarbon having 2 to 6 carbon atoms is more preferable.
In the formula OA-3, ^{R 7} has the same meaning as ^{R 7} in Formula IV, preferred embodiments are also the same.
In the formula OA-2, n3 is preferably an integer of 0 to 20, more preferably 1 to 10.
In the formula OA-2, m3 is preferably an integer of 2 to 3.

-Preferred embodiment of -n
In the formula II, n is preferably 2 or 3, and more preferably 2.

-Preferred embodiment of the compound represented by Formula II-
The compound represented by the formula II has a molecular weight (weight average molecular weight when having a distribution) of 5,000 or less, preferably 3,000 or less, more preferably 1,000 or less.

  The compound represented by the formula II is obtained, for example, by reacting a sulfonic acid halide compound represented by the following formula II-A with a polyfunctional amine compound represented by the following formula II-B.

In the above formula II-A and Formula II-B, ^{R 3} and ^{R 4} have the same meanings as ^{R 3} and ^{R 4} in Formula II, preferred embodiments are also the same.
In the above formula II-A, X represents a halogen atom, preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, more preferably a chlorine atom.
In the above formula II-B, n represents an integer of 2 to 4.

  Specific examples of the compound represented by Formula II include, but are not limited to, the following compounds. In addition, in the following specific examples, a subscript in parentheses representing an oxyalkylene unit represents the number of repetitions of the oxyalkylene unit, and Et represents an ethyl group.

[Compound represented by Formula III]
A preferred embodiment of the -R ⁵ -
In Formula III, R ⁵ is preferably independently a monovalent organic group, more preferably a group containing an alkyl group, an aryl group or an oxyalkylene group, and more preferably a group containing an oxyalkylene group.
A plurality of R ⁵ may be different from each other, but are preferably the same from the viewpoint of synthesis suitability.
The alkyl group and the aryl group have the same meanings as the alkyl group and the aryl group in R ¹ described above, and the preferred embodiments are also the same.
The oxyalkylene group contained in the group containing the oxyalkylene group is preferably a group represented by the above formula IV, and more preferably a group represented by the above formula V.
As the monovalent group containing the oxyalkylene group, a group represented by the following formula OA-4 is preferable.

In Formula OA-4, R ^x7 represents an alkylene group or an arylene group, or a structure represented by —C (＝ O) — or —NR ^N1 —R ^X8 — at a bonding site with an oxygen atom in Formula OA-4. R ^N1 represents a hydrogen atom or an alkyl group, R ^x8 represents an alkylene group, R ⁷ each independently represents an alkylene group having 2 to 6 carbon atoms, and R ^x6 represents Represents a hydrogen atom or an alkyl group, n represents an integer of 1 or more, and * represents a bonding site to another structure.

In Formula OA-4, R ^x7 is preferably an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 20 carbon atoms, preferably an alkylene group having 1 to 4 carbon atoms, a phenylene group or a naphthylene group, and more preferably a methylene group. preferable.
In Formula OA-4, ^RN1 represents a hydrogen atom or an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group.
In Formula OA-4, ^Rx8 represents an alkylene group, preferably an alkylene group having 2 to 4 carbon atoms, and more preferably a methylene group.
In the formula OA-4, ^{R 7} has the same meaning as ^{R 7} in Formula IV, preferred embodiments are also the same.
In Formula OA-4, n is preferably an integer of 1 to 20, more preferably 1 to 10.

A preferred embodiment of -R ⁶ -
In Formula III, R ⁶ is preferably a group containing a benzene ring structure, a group containing a polycyclic structure, or a group containing an oxyalkylene group.
From the viewpoint of the printing durability of the obtained lithographic printing plate, a group containing a benzene ring structure or a group containing a polycyclic structure is preferable, and a group containing an n-valent polycyclic structure is more preferable.
It is preferable that the lithographic printing plate is a group containing an oxyalkylene group from the viewpoint of the ink adhesion of the obtained lithographic printing plate.
Examples of the group containing an n-valent benzene ring structure include a group obtained by removing m hydrogen atoms from a benzene ring, or a divalent group represented by the following formula B-1.

In Formula B-1, R ^B1 represents a carbonyl group or a sulfonyl group, and * each independently represents a binding site to another structure.

  A group containing an n-valent polycyclic structure includes a naphthalene ring, an anthracene ring, a dihydroanthracene ring, a biphenyl structure, a terphenyl structure, a xanthone structure, an anthrone structure, or a group obtained by removing n hydrogen atoms from a xanthene structure. preferable.

  The group containing an n-valent oxyalkylene group is preferably a group represented by the above formula OA-3 or OA-4.

-Preferred embodiment of -n
In the formula III, n is preferably 2 or 3, and more preferably 2.

-Preferred embodiment of the compound represented by Formula III-
The compound represented by the formula III has a molecular weight (weight average molecular weight when having a distribution) of 5,000 or less, preferably 3,000 or less, and more preferably 2,000 or less.

  The compound represented by the formula III is obtained, for example, by reacting a sulfonic acid halide compound represented by the following formula III-A with a monofunctional amine compound represented by the following formula III-B.

In the formula III-A and Formula III-B, ^{R 5} and ^{R 6} have the same meanings as ^{R 5} and ^{R 6} in Formula III, preferred embodiments are also the same.
In the above formula III-A, X represents a halogen atom, preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, more preferably a chlorine atom.
In the above formula III-A, n represents an integer of 2 to 4.

  Specific examples of the compound represented by the formula III include, but are not limited to, the following compounds. In addition, in the following specific examples, the parenthesized subscripts representing the oxyalkylene units indicate the number of repetitions of the oxyalkylene units.

The positive photosensitive resin composition according to the present disclosure may contain the specific compound singly, or may contain two or more specific compounds.
The content of the specific compound is from 2% by mass to the total solid content of the positive photosensitive resin composition from the viewpoints of printing durability, chemical resistance, developability, and ink adhesion of the obtained lithographic printing plate. The content is preferably 30% by mass, more preferably 5% to 20% by mass.
In the present disclosure, the total solid content means a mass excluding a volatile component such as a solvent.

<Alkali-soluble resin>
The positive photosensitive resin composition according to the present disclosure contains an alkali-soluble resin.
In the present disclosure, “alkali-soluble” means that 0.01 g of the resin is dissolved in 5 g of an aqueous sodium hydroxide solution at 30 ° C. and pH 13.0 within 200 seconds. The term “dissolution” refers to a state in which the remaining of the dissolved substance is not visually confirmed.
Examples of the alkali-soluble resin include acrylic resin, polyurea, polyurethane, and polycarbonate.
From the viewpoints of printing durability and chemical resistance, polyurea, polyurethane or polycarbonate is preferred.
Hereinafter, preferred embodiments of the alkali-soluble resin according to the present disclosure will be described.

〔acrylic resin〕
As the alkali-soluble resin, for example, a compound known in the field of a positive-working lithographic printing plate precursor can be used without any particular limitation. However, the water-insoluble and alkali described in paragraphs 0025 to 0062 of JP-A-2008-151929 can be used. Soluble resins are preferred.
Among these, an acrylic resin having a sulfonamide group in a side chain or an acrylic resin having a phenolic hydroxy group in a side chain is preferable.

-Acrylic resin having sulfonamide group in side chain-
Examples of the acrylic resin having a sulfonamide group in a side chain include a copolymer containing a monomer unit formed by a monomer having a sulfonamide group.
The monomer having a sulfonamide group is not particularly limited, and examples thereof include a (meth) acrylamide compound having a sulfonamide group, a (meth) acrylate compound having a sulfonamide group, and a styrene compound having a sulfonamide group.
Specific examples include N- (p-toluenesulfonyl) acrylamide and N- (p-toluenesulfonyl) methacrylamide.
The copolymer may further include a monomer unit formed by another monomer. Examples of the other monomer include a known (meth) acrylate compound, a (meth) acrylamide compound, an acrylonitrile compound, and a styrene compound. And the monomers described in paragraphs 0034 to 0035 of JP-A-2008-151929 can also be suitably used.
In the present disclosure, a description such as a (meth) acrylate compound means an acrylate compound or a methacrylate compound.

-Acrylic resin having phenolic hydroxy group in side chain-
Examples of the acrylic resin having a phenolic hydroxy group in the side chain include a copolymer containing a monomer unit formed by a monomer having a phenolic hydroxy group.
The monomer having a phenolic hydroxy group is not particularly limited, and examples thereof include a (meth) acrylamide compound, a (meth) acrylate compound, and a hydroxystyrene compound having a phenolic hydroxyl group. Specifically, N- (2-hydroxyphenyl) acrylamide, N- (3-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) acrylamide, N- (2-hydroxyphenyl) methacrylamide, N- (3 -Hydroxyphenyl) methacrylamide, N- (4-hydroxyphenyl) methacrylamide, o-hydroxyphenyl acrylate, m-hydroxyphenyl acrylate, p-hydroxyphenyl acrylate, o-hydroxyphenyl methacrylate, m-hydroxyphenyl methacrylate, p- Hydroxyphenyl methacrylate, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (2-hydroxyphenyl) ethyl acrylate, 2- (3-hydroxyphenyl Preferred are ethyl acrylate, 2- (4-hydroxyphenyl) ethyl acrylate, 2- (2-hydroxyphenyl) ethyl methacrylate, 2- (3-hydroxyphenyl) ethyl methacrylate, 2- (4-hydroxyphenyl) ethyl methacrylate, and the like. Can be used.

  The copolymer in the acrylic resin having a sulfonamide group in the side chain and the acrylic resin having a phenolic hydroxy group in the side chain may further include a monomer unit formed by another monomer. And known (meth) acrylate compounds, acrylonitrile compounds, allyl cyanide compounds, styrene compounds, and the like, and the monomers described in paragraphs 0034 to 0035 of JP-A-2008-151929 can also be suitably used.

The weight average molecular weight of the acrylic resin having a sulfonamide group in the side chain or the acrylic resin having a phenolic hydroxyl group in the side chain is preferably more than 5,000 and 300,000 or less, and 10,000 to 200,000. More preferably, there is.
Specific examples of the acrylic resin having a sulfonamide group in the side chain or the acrylic resin having a phenolic hydroxyl group in the side chain are shown below, but are not limited thereto. In the following specific examples, parenthesized subscripts indicating monomer units represent the content (mol%) of each monomer unit, Me represents a methyl group, and Ph represents a phenyl group.

(Polyurea, polyurethane, polycarbonate)
Further, as the alkali-soluble resin, polyurea, polyurethane or polycarbonate can also be suitably used.
The polyurea, polyurethane or polycarbonate preferably has an acid group, and more preferably has a sulfonamide group in the main chain from the viewpoint of printing durability and developability.
The polyurea, polyurethane or polycarbonate preferably has another acid group in the side chain. As the acid group of the side chain, a phenolic hydroxyl group, a sulfonamide group, or a carboxy group is preferable.
Hereinafter, a polyurea having a sulfonamide group in the main chain, a polyurethane having a sulfonamide group in the main chain, and a polycarbonate having a sulfonamide group in the main chain are also collectively referred to as “specific polymer compound”.

-Polycyclic structure-
The specific polymer compound preferably further has a polycyclic structure in the main chain from the viewpoint of printing durability and chemical resistance.
The polycyclic structure means a condensed cyclic hydrocarbon structure, a condensed polycyclic aromatic structure, and a structure in which a plurality of aromatic hydrocarbons are bonded by a single bond, and includes a naphthalene derivative structure, an anthracene derivative structure, and a biphenyl structure. And a terphenyl structure. Among the naphthalene derivative structure and the anthracene derivative structure, a naphthalene structure, a xanthone structure, an anthrone structure, a xanthene structure, a dihydroanthracene structure, and an anthracene structure are preferable. , A biphenyl structure and a naphthalene structure are more preferable, and a xanthone structure and an anthrone structure are more preferable.

-Structural unit represented by Formula A-1-
The specific polymer compound used in the present disclosure preferably includes a structural unit represented by the following formula A-1 as the structural unit having the sulfonamide group.
Each of the two sulfonamide groups included in Formula A-1 is a sulfonamide group that the specific polymer compound has in the main chain.
Since the specific polymer compound contains the structural unit represented by the formula A-1, the acid value of the specific polymer compound is increased structurally, so that a positive lithographic printing plate precursor excellent in developability can be obtained.

In Formula A-1, R ⁴ represents a divalent linking group, and preferably represents a divalent linking group containing the above-described polycyclic structure or a divalent linking group containing a phenylene group. From the viewpoint of properties, it is more preferable to represent a divalent linking group having the above-mentioned polycyclic structure.
The specific polymer compound according to the present disclosure preferably contains 10% to 90% by mass, more preferably 30% to 80% by mass, and more preferably 50% by mass of the structural unit represented by Formula A-1. It is more preferred that the content be contained in an amount of from about 75% by mass.

-A divalent linking group containing a phenylene group-
The divalent linking group containing a phenylene group is preferably a phenylene group or a group represented by the following formula Ph-1.

In the formula Ph-1, ^{L B} is an ether bond (-O-) or sulfonyl group _{(-S (= O) 2 -} ) bond and represents the wavy line section represents a sulfur atom of the sulfonamide group in the formula A-1 Indicates a part.

When R ⁴ represents a phenylene group, the two sulfonamide groups in Formula A-1 are preferably bonded to the phenylene group so as to be in the meta position.
Further, the phenylene group may be substituted. Examples of the substituent include an alkyl group, a hydroxy group, and a halogen atom, and an alkyl group is preferable. The alkyl group is preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group.

-Structural unit represented by Formula B1-1 to Formula B1-6-
The structural unit represented by the formula A-1 preferably includes a structural unit represented by any of the following formulas B1-1 to B1-6, and is represented by the following formula B1-1 or B1-2. It is more preferable to include the structural unit.

In the formula B1-1~ formula ^{B1-6, R B11, R B12,} R B21, R B22, R B31 ~R B33, R B41, R B42, R B51, R B52, ^and, R B61 ^{to R B63} each And independently represents a hydrogen atom, a sulfonamide group, a hydroxy group, a carboxy group, an alkyl group, or a halogen atom, and ^ZB11 represents -C (R) _2- , -C (= O)-, -O-, -NR-, -S- or a single bond; ^ZB21 represents -C (R) _2- , -O-, -NR-, -S- or a single bond, and R is each independently a hydrogen atom Or an alkyl group, ^XB21 represents -C (R ') _2- , -O-, -NR'-, -S- or a single bond, and R' each independently represents a hydrogen atom, or Represents an alkyl group.

In the formula B1-1~ formula ^{B1-6, R B11, R B12,} R B21, R B22, R B31 ~R B33, R B41, R B42, R B51, R B52, ^and, R B61 ^{to R B63} each Independently, it represents a hydrogen atom, a sulfonamide group, a hydroxyl group, a carboxy group, an alkyl group, or a halogen atom, and is preferably a hydrogen atom, an alkyl group, or a halogen atom, and more preferably a hydrogen atom. Further, from the viewpoint of improving developability, an acid group such as a sulfonamide group, a hydroxyl group, and a carboxy group is preferable.
In Formulas B1-1 to B1-6, Z ^B11 and Z ^B21 each independently represent —C (R) ₂ —, —O—, —NR—, —S—, or a single bond; ) It is preferably _2- , -O-, and more preferably -O-.
In Formulas B1-1 to B1-6, R represents a hydrogen atom or an alkyl group, and is preferably a hydrogen atom.
In the formula B1-1~ formula ^{B1-6, X B21} is _{-C (R ') 2 -,} - O -, - NR' -, - S- or a single bond, -C (R _{') 2} - in Preferably, there is.
In Formulas B1-1 to B1-6, R ′ represents a hydrogen atom or an alkyl group, and is preferably a hydrogen atom.

  The specific polymer compound according to the present disclosure preferably includes the structure represented by Formulas B1-1 to B1-6 in an amount of 10% by mass to 90% by mass, more preferably 30% by mass to 80% by mass. , 50% by mass to 75% by mass.

  Examples of the specific polymer compound include a polyurea having a sulfonamide group in the main chain, a polyurethane having a sulfonamide group in the main chain, and a polycarbonate having a sulfonamide group in the main chain described in WO 2016/1333072. It can be suitably used.

Further, the specific polymer compound according to the present disclosure preferably has a weight average molecular weight of 10,000 to 500,000, more preferably 10,000 to 200,000, and more preferably 20,000 to 100,000. It is even more preferred.
Hereinafter, the specific polymer compound will be described with reference to specific examples.

-Polyurea having a sulfonamide group in the main chain-
As the specific polymer compound used in the present disclosure, polyurea having a sulfonamide group in the main chain is preferable.
Polyurea having a sulfonamide group in the main chain is a polymer formed by a sequential polymerization reaction of a specific diamine compound having a sulfonamide group in the main chain and a compound having two or more isocyanate groups (a diisocyanate compound). There is no particular limitation as long as the polyurea has a sulfonamide group in the main chain.
Note that the main chain of the diamine compound refers to a carbon chain that becomes the main chain of the high molecular compound when a high molecular compound such as polyurea is formed.
Preferred specific examples of the polyurea that can be used in the present disclosure are shown below. Specific examples PU-1 to PU-20 are described in the table below with a diamine compound having a sulfonamide group in the main chain described later, a compound having two or more isocyanate groups, and optionally other diamine compounds. It means a polymer compound formed by reaction at a ratio (molar ratio).
In the table, the molar ratio used for the synthesis of polyurea and the weight average molecular weight (Mw) of the obtained polyurea having a sulfonamide group in the main chain are shown. The polyurea contained is not limited to these.

  Details of the compounds indicated by the abbreviations in the table are as follows.

-Polyurethane having sulfonamide group in main chain-
As the specific polymer compound used in the present disclosure, polyurethane having a sulfonamide group in the main chain is preferable.
As used in the present disclosure, polyurethane having a sulfonamide group in the main chain is a polymer formed by a sequential polymerization reaction of a specific diol compound having a sulfonamide group in the main chain and a compound having two or more isocyanate groups. There is no particular limitation as long as the polyurethane has a sulfonamide group in the main chain.
Note that the main chain of the diol compound refers to a carbon chain that becomes the main chain of the high molecular compound when a high molecular compound such as polyurethane is formed.
Preferred specific examples of the polyurethane that can be used in the present disclosure are shown in the table below. Specific examples PT-1 to PT-20 react a diol compound containing a sulfonamide group in the main chain described later with a compound having two or more isocyanate groups at a ratio (molar ratio) shown in the table below. Means a polymer compound prepared by the method.
Further, in the table, the molar ratio used for the synthesis of the polyurethane and the obtained weight average molecular weight (Mw) of the polyurethane having the sulfonamide group in the main chain are shown, and the sulfonamide group used in the present disclosure is used in the main chain. The polyurethane having is not limited to these.

  Details of the compounds other than the compounds described above among the compounds indicated by the abbreviations in the table are as follows.

-Polycarbonate having a sulfonamide group in the main chain-
As the polymer compound used in the present disclosure, a polycarbonate having a sulfonamide group in the main chain is preferable.
The polycarbonate having a sulfonamide group in the main chain used in the present disclosure refers to a diol compound using a compound having a carbonate group such as an alkyl carbonate (for example, diethyl carbonate or the like) and a sulfonamide group in the main chain. There is no particular limitation as long as it is a polymer produced by a sequential polymerization reaction with a diol compound and has a sulfonamide group in the main chain.

(Other alkali-soluble resins)
The other alkali-soluble resin is not particularly limited as long as it has a property of dissolving when it comes into contact with an alkaline developer, but at least one of a main chain and a side chain in the polymer has a sulfonic acid group and a phosphate group. , A sulfonamide group, an active imide group or the like having an acidic functional group is preferable, and a resin containing such a monomer having an acidic functional group imparting alkali solubility of 10 mol% or more, and 20 mol% The resin containing the above is more preferable. When the copolymerization component of the monomer imparting alkali solubility is 10 mol% or more, sufficient alkali solubility can be obtained and developability is excellent.

As another alkali-soluble resin, a novolak resin is also preferably mentioned.
Novolak resins that can be used in the positive photosensitive resin composition according to the present disclosure include phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin, phenol / cresol (Either m-, p-, or m- / p-mixture may be used.) A novolak resin such as a mixed formaldehyde resin and a pyrogallol acetone resin are preferred.
Further, as described in U.S. Pat. No. 4,123,279, a phenol having a C3-8 alkyl group as a substituent, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, is used. And condensation polymers with formaldehyde. Further, the weight average molecular weight (Mw) is preferably 500 or more, more preferably 1,000 to 700,000. Further, the number average molecular weight (Mn) is preferably 500 or more, and more preferably 750 to 650,000. The degree of dispersion (weight average molecular weight / number average molecular weight) is preferably from 1.1 to 10.

  The other alkali-soluble resin preferably has a weight average molecular weight of 2,000 or more and a number average molecular weight of 500 or more, and has a weight average molecular weight of more than 5,000 to 300,000 and a number average molecular weight of 800. More preferably, it is で 250,000. The dispersity (weight average molecular weight / number average molecular weight) of the other alkali-soluble resin is preferably 1.1 to 10.

-Content-
The alkali-soluble resin in the present disclosure may be used alone or in combination of two or more.
Further, the content of the alkali-soluble resin in the present disclosure is preferably from 10% by mass to 90% by mass, and preferably from 20% by mass to 80% by mass based on the total solid content of the positive photosensitive resin composition. Is more preferable, and it is still more preferable that it is 30 to 80 mass%.

<Infrared absorber>
The positive photosensitive resin composition according to the present disclosure contains an 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.
Examples of the infrared absorber that can be used in the present disclosure include the infrared absorbers described in paragraphs 0075 to 0085 of WO 2016/047392.

  Of these dyes, particularly preferred are cyanine dyes, phthalocyanine dyes, oxonol dyes, squarylium dyes, pyrylium salts, thiopyrylium dyes, and nickel thiolate complexes. Furthermore, when the cyanine dye represented by the following formula (a) is used in the upper layer of the positive-working lithographic printing plate precursor according to the present disclosure, the release of the dissolution inhibiting effect by exposure is good, and the stability and economy are improved. It is most preferable because of excellent properties.

In the formula (a), X ¹ represents a hydrogen atom, a halogen atom, a diarylamino group, -X ² -L ¹ or a group represented by the following formula (b). 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 containing a hetero atom. . In addition, a hetero atom here represents N, S, O, a halogen atom, or Se.

In the above formula (b), Xa ^- is Za described later ^- has the same definition as, R ^a represents a hydrogen atom, an alkyl group, an aryl group, selected substituted or unsubstituted amino group, and from the group consisting of a halogen atom Represents a substituent.

R ²¹ and R ²² each independently represent a hydrocarbon group having 1 to 12 carbon atoms. From the viewpoint of the storage stability of the positive planographic printing plate precursor, R ²¹ and R ²² are preferably a hydrocarbon group having at least 2 carbon atoms, further bound to each other and R ²¹ and R ^22, 5 It is particularly preferable to form a six-membered or six-membered ring.

Ar ¹ and Ar ² may be the same or different, and represent an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Preferred substituents include a hydrocarbon group having 1 to 12 carbon atoms, a halogen atom, and an alkoxy group having 1 to 12 carbon atoms.
Y ¹¹ and Y ¹² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 3 to 12 carbon atoms. R ²³ and R ²⁴ may be the same or different, and represent a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. Preferred substituents include an alkoxy group having 1 to 12 carbon atoms, a carboxyl group, and a sulfo group.
R ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ may be the same or different and each represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. From the viewpoint of availability of raw materials, a hydrogen atom is preferable. Furthermore, Za ^- represents a counter anion. However, it has an anionic substituent in the cyanine dye in its structure represented by formula (a), does not necessitate neutralization of the charge, Za ^- is not necessary. Preferred Za ⁻ are a halide ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion from the viewpoint of the storage stability of the positive type lithographic printing plate precursor, and particularly preferably, Chlorate ion, hexafluorophosphate ion, and arylsulfonate ion.

  Specific examples of the cyanine dye represented by the formula (a) that can be suitably used include paragraphs 0017 to 0019 of JP-A-2001-133969, paragraphs 0012 to 0038 of JP-A-2002-40638, and JP-A-2002-40638. Examples described in paragraphs 0012 to 0023 of JP-A-2002-23360 can be exemplified. Particularly preferred as the infrared absorbing agent is the following cyanine dye A.

  The content of the infrared absorber in the present disclosure is preferably 0.01% by mass to 50% by mass, and more preferably 0.1% by mass to 30% by mass based on the total solid content of the positive photosensitive resin composition. More preferably, it is particularly preferably from 1.0% by mass to 30% by mass. When the content is 0.01% by mass or more, high sensitivity is obtained, and when the content is 50% by mass or less, the obtained layer has good uniformity and excellent layer durability.

<Acid generator>
The positive photosensitive resin composition according to the present disclosure preferably contains an acid generator from the viewpoint of improving sensitivity to exposure.
In the present disclosure, the acid generator is a compound that generates an acid by light or heat, and refers to a compound that generates an acid by being decomposed by irradiation with infrared rays or heating at 100 ° C. or more. The generated acid 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 increases the permeability of the developing solution to the exposed portion, and further improves the solubility of the exposed portion in an aqueous alkaline solution.

  Examples of the acid generator suitably used in the positive photosensitive resin composition according to the present disclosure include the acid generators described in paragraphs 0116 to 0130 of WO2016 / 047392.

Among them, 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 positive photosensitive resin composition according to the present disclosure include infrared exposure, and a compound known as a compound that decomposes by thermal energy generated from an infrared absorber upon exposure to generate an acid. Can be mentioned. As the onium salt compound suitable for the positive photosensitive resin composition according to the present disclosure, from the viewpoint of sensitivity, a compound having a known thermal polymerization initiator or a bond having a small bond dissociation energy and having an onium salt structure described below. Can be mentioned.
Examples of the onium salt suitably used in the positive photosensitive resin composition according to the present disclosure include known diazonium salts, iodonium salts, sulfonium salts, ammonium salts, pyridinium salts, azinium salts and the like, among which triarylsulfonium Or a diaryliodonium sulfonate, carboxylate, BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ or the like.
Examples of the onium salt that can be used as the acid generator in the positive photosensitive resin composition according to the present disclosure include onium salts represented by the following formulas (III) to (V).

In the above formula (III), Ar ¹¹ and Ar ¹² each independently represent an optionally substituted aryl group having 6 to 20 carbon atoms. When the aryl group has a substituent, preferred substituents include a halogen atom, a nitro group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an aryloxy group having 1 to 12 carbon atoms. Is mentioned. Z ¹¹⁻ is a pair selected from the group consisting of a halide ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a sulfonate ion, and a sulfonate ion having a fluorine atom such as a perfluoroalkyl sulfonate ion. Represents an ion, preferably perchlorate ion, hexafluorophosphate ion, arylsulfonate ion, and perfluoroalkylsulfonic acid.
In the above formula (IV), Ar ²¹ represents an optionally substituted aryl group having 6 to 20 carbon atoms. Preferred substituents include a halogen atom, a nitro group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 1 to 12 carbon atoms, an alkylamino group having 1 to 12 carbon atoms, Examples thereof include a dialkylamino group having 2 to 12 carbon atoms, an arylamino group having 6 to 12 carbon atoms, and a diarylamino group (each independently having 6 to 12 carbon atoms in the aryl group). Z ^21- represents a counter ion having the same ^meaning as Z ^11- .
In the formula (V), R ³¹ , R ³² and R ³³ may be the same or different, and represent a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. Preferred substituents include a halogen atom, a nitro group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryloxy group having 1 to 12 carbon atoms. Z ^31- represents a counter ion having the same ^meaning as Z ^11- .

  Specific examples of the onium salt that can be suitably used in the positive-type photosensitive resin composition according to the present disclosure are the same as the compounds described in paragraphs 0121 to 0124 of WO2016 / 047392.

  Further, as another example of the compounds represented by the above formulas (III) to (V), compounds described as examples of a radical polymerization initiator in paragraphs 0036 to 0045 of JP-A-2008-195018 are exemplified. It can be suitably used as an acid generator in the positive photosensitive resin composition according to the present disclosure.

  More preferred examples of the acid generator that can be used in the positive photosensitive resin composition according to the present disclosure include compounds represented by the following formulas PAG-1 to PAG-5. In the formulas PAG-1 to PAG-5, Me represents a methyl group.

When these acid generators are contained in the positive photosensitive resin composition according to the present disclosure, these compounds may be used alone or in combination of two or more.
The preferred content of the acid generator is 0.01% by mass to 50% by mass, preferably 0.1% by mass to 40% by mass, more preferably 0.1% by mass, based on the total solid content of the positive photosensitive resin composition. It is in the range of 5% by mass to 30% by mass. When the content is in the above range, the sensitivity as an effect of the addition of the acid generator is improved, and the generation of a residual film in the non-image area is suppressed.

<Acid multiplying agent>
The positive photosensitive resin composition according to the present disclosure may contain an acid multiplying agent. The acid proliferating agent in the positive-type photosensitive resin composition according to the present disclosure is a compound substituted with a relatively strong acid residue, and is easily eliminated in the presence of an acid catalyst to newly form an acid. It is a compound that is generated. That is, it is decomposed by an acid-catalyzed reaction to generate an acid again. One or more acids are increased in one reaction, and the acid concentration is rapidly increased with the progress of the reaction, so that the sensitivity is dramatically improved. The strength of the generated acid is preferably 3 or less, more preferably 2 or less, as an acid dissociation constant (pKa). If the acid dissociation constant is 3 or less, an acid-catalyzed elimination reaction is likely to occur.
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.

  Acid proliferating agents that can be used are the same as those described in paragraphs 0133 to 0135 of WO 2016/047392.

  The content of these acid proliferating agents is 0.01% by mass to 20% by mass, preferably 0.01% by mass to 10% by mass, with respect to the total mass of the positive photosensitive resin composition according to the present disclosure. More preferably, it is in the range of 0.1% by mass to 5% by mass. When the content of the acid multiplying agent is in the above range, the effect of adding the acid multiplying agent is sufficiently obtained, the sensitivity to exposure is improved, and the decrease in the film strength of the image area is suppressed.

<Other additives>
The positive photosensitive resin composition according to the present disclosure may include, as other additives, a development accelerator, a surfactant, a printing-out / coloring agent, a plasticizer, a waxing agent, and the like. These can be the same as described in paragraphs 0138 to 0142 of WO 2016/047392.

<Composition ratio of each component>
The content of the specific compound is preferably from 2% by mass to 30% by mass, and the content of the alkali-soluble resin is preferably from 10% by mass to 90%, based on the total solid content of the positive photosensitive resin composition according to the present disclosure. % By mass, the content of the infrared absorber is preferably from 0.01 to 50% by mass, and the content of the acid generator is preferably from 0 to 50% by mass. The content is preferably 0 to 20% by mass, the content of the development accelerator is preferably 0 to 20% by mass, and the content of the surfactant is preferably 0 to 5% by mass. The content of the printing-out agent / colorant is preferably 0 to 10% by mass, the content of the plasticizer is preferably 0 to 10% by mass, and the content of the wax agent is 0 to 10% by mass. Preferably, there is.

<Use of positive photosensitive resin composition>
The positive photosensitive resin composition according to the present disclosure can be applied to various fields that require resin pattern formation with excellent durability, for example, various fields such as resists, displays, and lithographic printing plate precursors. .
In particular, the positive-type photosensitive resin composition according to the present disclosure is preferably applied to a positive-type lithographic printing plate precursor because it has excellent ink deposition properties and chemical resistance.
In addition, the positive photosensitive resin composition according to the present disclosure is capable of recording with high sensitivity, has excellent image forming properties, and has a good durability of the formed image area. It can be said that it is preferable to apply to the original plate.

(Positive lithographic printing plate precursor)
The positive planographic printing plate precursor according to the present disclosure has an image recording layer containing the positive photosensitive resin composition according to the present disclosure on a support having a hydrophilic surface.
Further, the image recording layer may have, on the support, an image recording layer having an upper layer and an upper layer in this order, and the positive photosensitive resin composition may be contained in at least one of the lower layer and the upper layer. Preferably, it is more preferably contained in the lower or upper layer, and even more preferably in only the lower layer.

<Image recording layer>
The image recording layer of the positive-type lithographic printing plate precursor according to the present disclosure may be formed by dissolving each component of the positive-type photosensitive resin composition according to the present disclosure in a solvent, and coating the solution on a suitable support. Can be.
As the solvent used here, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyrolactone, toluene and the like can be mentioned. However, the present invention is not limited to this. These solvents are used alone or as a mixture.

<Formation of lower layer and upper layer>
Further, the positive lithographic printing plate precursor according to the present disclosure includes a positive lithographic printing plate precursor having an image recording layer having a lower layer and an upper layer in this order on a support (hereinafter, referred to as a “positive lithographic printing plate precursor having a two-layer structure”). ).).
The lower layer and the upper layer are preferably formed in principle by separating the two layers.
As a method of forming the two layers separately, for example, a method utilizing the difference in solvent solubility between the components contained in the lower layer and the components contained in the upper layer, or a method of rapidly applying the solvent after coating the upper layer And a method of drying and removing the same. It is preferable to use the latter method in combination, since the separation between the layers can be performed more favorably.
Hereinafter, these methods will be described in detail, but the method of applying the two layers separately is not limited thereto.

  As a method utilizing the difference in solvent solubility between the components contained in the lower layer and the components contained in the upper layer, when applying the coating solution for the upper layer, use a solvent system in which none of the components contained in the lower layer is insoluble Things. Thereby, even if the two-layer coating is performed, each layer can be clearly separated into a coating film. For example, as the lower layer component, a component insoluble in a solvent such as methyl ethyl ketone or 1-methoxy-2-propanol that dissolves the alkali-soluble resin as the upper layer component is selected, and the lower layer is applied using a solvent system that dissolves the lower layer component. After drying, the upper layer mainly composed of an alkali-soluble resin is dissolved in methyl ethyl ketone, 1-methoxy-2-propanol, or the like, applied, and dried to form a two-layer structure.

  Next, as a method for drying the solvent very quickly after the application of the second layer (upper layer), high-pressure air is blown from a slit nozzle installed substantially at right angles to the running direction of the web, or steam or the like is heated. This can be achieved by applying heat energy as conduction heat from the lower surface of the web from a roll (heating roll) supplied with the medium therein, or by combining them.

  The positive photosensitive resin composition according to the present disclosure is preferably contained in at least one of the lower layer and the upper layer, and more preferably contained only in the lower layer.

Coating amount after drying of a lower layer component applied onto the support of the positive planographic printing plate precursor according to the present disclosure is preferably in the range of ^{0.5g / m 2 ~4.0g / m 2} , 0 More preferably, it is in the range of 0.6 g / m ^{2 to 2.5} g / m ² . When it is 0.5 g / m ² or more, printing durability is excellent, and when it is 4.0 g / m ² or less, image reproducibility and sensitivity are excellent.
The coating amount after drying of the upper layer component ^is preferably in the range of ^{0.05g / m 2 ~1.0g / m 2} , in the range of 0.08g / ^{m 2} ~0.7g / m 2 Is more preferable. If it is 0.05 g / ^{m 2} or more, development latitude, and excellent scratch resistance, if it is 1.0 g / ^{m 2} or less, excellent sensitivity.
The lower layer and the coating amount after drying of the combined upper layer is ^preferably in the range of ^{0.6g / m 2 ~4.0g / m 2} , the range of 0.7g / ^{m 2} ~2.5g / m 2 Is more preferable. When it is 0.6 g / m ² or more, printing durability is excellent, and when it is 4.0 g / m ² or less, image reproducibility and sensitivity are excellent.

<Upper layer>
The upper layer of the positive-working lithographic printing plate precursor having a two-layer structure in the present disclosure may be a layer containing the positive-working photosensitive resin composition according to the present disclosure, but may be a positive-working photosensitive resin composition according to the present disclosure. It is preferable that the layer contains a resin composition other than the above.
The upper layer of the positive-working lithographic printing plate precursor having a two-layer structure in the present disclosure is preferably an infrared-sensitive positive-working image-recording layer whose solubility in an aqueous alkali solution is improved by heat.
There is no particular limitation on the mechanism by which the heat in the upper layer improves the solubility in an aqueous alkali solution, and any mechanism can be used as long as it contains a binder resin and improves the solubility of the heated region. Examples of the heat used for image formation include heat generated when a lower layer containing an infrared absorbent is exposed.
As the upper layer whose solubility in an aqueous alkali solution is improved by heat, for example, a layer containing an alkali-soluble resin having a hydrogen bonding ability such as novolak or urethane, a water-insoluble and alkali-soluble resin and a compound having a dissolution inhibiting action are included. Preferred examples include a layer, a layer containing an ablatable compound, and the like.

  Further, by further adding an infrared absorber to the upper layer, heat generated in the upper layer can be used for image formation. Examples of the configuration of the upper layer containing an infrared absorber include, for example, a layer containing an infrared absorber, a water-insoluble and alkali-soluble resin and a compound having a dissolution inhibiting effect, an infrared absorber, a water-insoluble and alkali-soluble resin, and an acid generator. And the like.

(Water-insoluble and alkali-soluble resin)
The upper layer of the positive-working lithographic printing plate precursor having a two-layer structure in the present disclosure preferably contains a water-insoluble and alkali-soluble resin. By containing the water-insoluble and alkali-soluble resin, an interaction is formed between the infrared absorber and the polar group of the water-insoluble and alkali-soluble resin, and a positive photosensitive layer is formed.
The general water-insoluble and alkali-soluble resin will be described in detail below. Among them, for example, preferably, a polyamide resin, an epoxy resin, a polyacetal resin, an acrylic resin, a methacrylic resin, a polystyrene-based resin, a novolac-type phenol-based resin and the like are preferable. be able to.
The water-insoluble and alkali-soluble resin is not particularly limited as long as it has a property of dissolving when brought into contact with an alkaline developer, but a resin containing an acidic group in at least one of a main chain and a side chain in a polymer is used. It is preferably a polymer, a copolymer thereof, or a mixture thereof.
The water-insoluble and alkali-soluble resin having such an acidic group preferably has a functional group such as a phenolic hydroxyl group, a carboxy group, a sulfonic acid group, a phosphoric acid group, a sulfonamide group, and an active imide group. Therefore, such a resin can be suitably produced by copolymerizing a monomer mixture containing at least one ethylenically unsaturated monomer having the above functional group. Preferred examples of the ethylenically unsaturated monomer having the above functional group include compounds represented by the following formula and mixtures thereof in addition to acrylic acid and methacrylic acid. In the following formula, R ⁴⁰ represents a hydrogen atom or a methyl group.

  The water-insoluble and alkali-soluble resin is preferably a polymer compound obtained by copolymerizing another polymerizable monomer in addition to the polymerizable monomer. As the copolymerization ratio in this case, 10 mol of a monomer that imparts alkali solubility, such as a monomer having a functional group such as a phenolic hydroxyl group, a carboxy group, a sulfonic acid group, a phosphoric acid group, a sulfonamide group, and an active imide group, is used. %, More preferably 20 mol% or more. When the copolymerization component of the monomer imparting alkali solubility is 10 mol% or more, sufficient alkali solubility can be obtained and developability is excellent.

As other polymerizable monomers that can be used, the following compounds can be exemplified.
Alkyl acrylates and alkyl methacrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, benzyl acrylate, methyl methacrylate, ethyl methacrylate, cyclohexyl methacrylate, and benzyl methacrylate; Acrylic esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, and methacrylic esters. Acrylamide or methacrylamide such as acrylamide, methacrylamide, N-methylacrylamide, N-ethylacrylamide, and N-phenylacrylamide. Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, and vinyl benzoate. Styrenes such as styrene, α-methylstyrene, methylstyrene, and chloromethylstyrene. Other nitrogen atom-containing monomers such as N-vinylpyrrolidone, N-vinylpyridine, acrylonitrile, and methacrylonitrile. N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-butylmaleimide, N-phenylmaleimide, N-2-methylphenylmaleimide, N-2,6-diethylphenylmaleimide, N-2-chlorophenylmaleimide, Maleimides such as N-cyclohexylmaleimide, N-laurylmaleimide and N-hydroxyphenylmaleimide.
Among these other ethylenically unsaturated monomers, (meth) acrylates, (meth) acrylamides, maleimides, and (meth) acrylonitrile are preferably used.

As the alkali-soluble resin, a novolak resin mentioned as another alkali-soluble resin as an optional component of the positive photosensitive resin composition according to the present disclosure is also preferably exemplified.
Further, the above-mentioned water-insoluble and alkali-soluble resin can be used in the positive photosensitive resin composition according to the present disclosure.

Further, in the upper layer of the positive-working lithographic printing plate precursor having a two-layer structure according to the present disclosure, other resins can be used in combination within a range that does not impair the effects of the positive-working lithographic printing plate precursor according to the present disclosure. Since the upper layer itself must exhibit alkali solubility, particularly in the non-image area, it is necessary to select a resin that does not impair this property. From this viewpoint, examples of the resin that can be used in combination include a water-insoluble and alkali-soluble resin. The general water-insoluble and alkali-soluble resin will be described in detail below. Among them, for example, preferably, a polyamide resin, an epoxy resin, a polyacetal resin, an acrylic resin, a methacrylic resin, a polystyrene-based resin, a novolac-type phenol-based resin and the like are preferable. be able to.
The mixing amount is preferably 50% by mass or less based on the water-insoluble and alkali-soluble resin.

The water-insoluble and alkali-soluble resin preferably has a weight average molecular weight of 2,000 or more and a number average molecular weight of 500 or more, has a weight average molecular weight of 5,000 to 300,000, and a number average molecular weight of 800 to 800. More preferably, it is 250,000. The degree of dispersion (weight average molecular weight / number average molecular weight) of the alkali-soluble resin is preferably from 1.1 to 10.
The water-insoluble and alkali-soluble resins may be used alone or in combination of two or more.
The content of the water-insoluble and alkali-soluble resin may be 2.0% by mass to 99.5% by mass based on the total solid content of the upper layer of the positive-working lithographic printing plate precursor having a two-layer structure in the present disclosure. Preferably, it is 10.0 mass%-99.0 mass%, more preferably, 20.0 mass%-90.0 mass%. When the content of the alkali-soluble resin is 2.0% by mass or more, the durability of the image recording layer (photosensitive layer) is excellent, and when the content is 99.5% by mass or less, both the sensitivity and the durability are improved. Excellent.

(Infrared absorber)
The upper layer may include an infrared absorber.
The infrared absorber is not particularly limited as long as it is a dye that absorbs infrared light and generates heat, and the above-described infrared absorber used in the positive photosensitive resin composition according to the present disclosure may be similarly used. Can be.
Particularly preferred dyes are the cyanine dyes represented by the above formula (a).

By containing an infrared absorbing agent in the upper layer, a positive lithographic printing plate precursor excellent in image formability can be obtained.
The content of the infrared absorbent in the upper layer is preferably from 0.01% by mass to 50% by mass, more preferably from 0.1% by mass to 30% by mass, based on the total solid content of the upper layer. It is particularly preferred that the content is 0.0% by mass to 10% by mass. When the content is 0.01% by mass or more, the sensitivity is improved. When the content is 50% by mass or less, the uniformity of the layer is good, and the durability of the layer is excellent.

[Other components]
In addition, the upper layer in the positive type lithographic printing plate precursor having a two-layer structure may contain an acid generator, an acid multiplying agent, a development accelerator, a surfactant, a printing-out agent, a coloring agent, a plasticizer, a waxing agent, and the like.
As these components, the respective components used in the positive photosensitive resin composition according to the present disclosure described above can be used in the same manner, and preferred embodiments are also the same.

<Lower layer>
The lower layer of the positive-working lithographic printing plate precursor having a two-layer structure in the present disclosure is preferably a layer containing the positive-type photosensitive resin composition according to the present disclosure.
Further, the lower layer of the positive-working lithographic printing plate precursor having a two-layer structure in the present disclosure is preferably formed by applying the positive-type photosensitive resin composition according to the present disclosure.
By using the positive photosensitive resin composition according to the present disclosure for the lower layer, a printing plate excellent in image formability and printing durability can be obtained.
In addition, by using the positive photosensitive resin composition according to the present disclosure for the lower layer, printing durability is improved, particularly when low-quality materials such as ink and paper are used.
Although the detailed mechanism by which the above-described effects are obtained is unknown, it is assumed that the film durability of the resin used for the lower layer is important for the printing durability in printing. It is presumed that use of the positive photosensitive resin composition according to the present disclosure having a high film strength due to high strength as the lower layer improves the printing durability.

  When the positive photosensitive resin composition according to the present disclosure is used for the upper layer, it is preferable that the lower layer is also formed of the positive photosensitive resin composition according to the present disclosure, but the lower layer is the positive photosensitive resin composition according to the present disclosure. It may be formed using a resin composition other than the product. In this case, the preferred embodiment of the lower layer is the same as the preferred embodiment of the upper layer described above.

<Support>
The support used in the positive-working lithographic printing plate precursor according to the present disclosure is not particularly limited as long as it is a dimensionally stable plate having the necessary strength and durability. The same supports as described in paragraphs 0166 to 0169 of No. 047392 can be used.
Among the above descriptions, an aluminum support is particularly preferable, and an aluminum support subjected to a hydrophilic treatment is preferable.

<Undercoat layer>
The positive planographic printing plate precursor according to the present disclosure preferably has an undercoat layer between the support having the hydrophilic surface and the image recording layer.
As the undercoat layer component, various organic compounds are used, for example, carboxymethylcellulose, phosphonic acids having an amino group such as dextrin, organic phosphonic acid, organic phosphoric acid, organic phosphinic acid, amino acids, and a hydroxy group. Preferred examples include a hydrochloride of an amine having the same. These undercoat layer components may be used alone or in combination of two or more. The details of the compound used for the undercoat layer and the method of forming the undercoat layer are described in paragraphs 0171 to 0172 of JP-A-2009-175195, and these descriptions also apply to the present disclosure.
The coverage of the undercoat layer ^is preferably from ^{2mg / m 2 ~200mg / m 2} , and more preferably ^{5mg / m 2 ~100mg / m 2} . When the coating amount is within the above range, sufficient printing durability can be obtained.

<Back coat layer>
On the back surface of the support of the positive working lithographic printing plate precursor according to the present disclosure, a back coat layer is provided as necessary. The back coat layer comprises an organic polymer compound described in JP-A-5-45885 and a metal oxide obtained by hydrolyzing and polycondensing 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 and Si (OC ₄ H ₉ ) ₄ are available at low cost. The coating layer of a metal oxide obtained therefrom is particularly preferable because it has excellent developer resistance.

(How to make a lithographic printing plate)
The method for producing a lithographic printing plate according to the present disclosure includes an exposure step of image-exposing the positive-type lithographic printing plate precursor according to the present disclosure, and a step of converting the exposed positive-type lithographic printing plate precursor to an alkali having a pH of 8.5 to 13.5. And a developing step of developing using an aqueous solution.
According to the method for producing a lithographic printing plate according to the present disclosure, a lithographic printing plate excellent in ink deposition property and chemical resistance can be obtained.
Hereinafter, each step of the method for producing a lithographic printing plate according to the present disclosure will be described in detail.

<Exposure process>
The method for producing a lithographic printing plate according to the present disclosure includes an exposure step of exposing the positive lithographic printing plate precursor according to the present disclosure to an image. The details are the same as those described in paragraphs 0173 to 0175 of WO 2016/047392.

<Development process>
The method for producing a lithographic printing plate according to the present disclosure includes a developing step of developing using an alkaline aqueous solution having a pH of 8.5 to 13.5 (hereinafter, also referred to as a “developer”).
The developing solution used in the developing step is an aqueous solution having a pH of 8.5 to 13.5, and an alkaline aqueous solution having a pH of 12 to 13.5 is more preferable. Surfactants contribute to improvement in processability.
Further, the developer preferably contains a surfactant, and more preferably contains at least an anionic surfactant or a nonionic surfactant. Surfactants contribute to improvement in processability.
As the surfactant used in the developer, any of anionic, nonionic, cationic, and amphoteric surfactants can be used. As described above, anionic or nonionic surfactants can be used. Agents are preferred.
The anionic, nonionic, cationic, and amphoteric surfactants used in the developer in the method for producing a lithographic printing plate according to the present disclosure include those described in paragraphs 0128 to 0131 of JP-A-2013-134341. Things can be used.

Further, from the viewpoint of stable solubility or turbidity in water, the HLB (Hydrophile-Lipophile Balance) value is preferably 6 or more, and more preferably 8 or more.
As the surfactant used in the developer, an anionic surfactant and a nonionic surfactant are preferable, and an anionic surfactant containing a sulfonic acid or a sulfonic acid salt, and having an aromatic ring and an ethylene oxide chain. Nonionic surfactants are particularly preferred.
Surfactants can be used alone or in combination.
The content of the surfactant in the developer is preferably 0.01% by mass to 10% by mass, and more preferably 0.01% by mass to 5% by mass.

  In order to maintain the developer at pH 8.5 to pH 13.5, the presence of carbonate ions and hydrogen carbonate ions as buffering agents can suppress fluctuations in pH even when the developer is used for a long period of time. It is possible to suppress a decrease in developability due to the fluctuation, generation of development scum and the like. In order for carbonate ions and bicarbonate ions to be present in the developing solution, carbonate and bicarbonate may be added to the developing solution, 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% by mass to 20% by mass, more preferably 0.5% by mass to 10% by mass, and more preferably 1% by mass to 5% by mass, based on the total mass of the developer. % Is particularly preferred. When the total amount is 0.3% by mass or more, the developability and processing capacity do not decrease, and when the total amount is 20% by mass or less, precipitation and crystals are hardly generated. It is difficult to gel and does not hinder waste liquid treatment.

After the development step, a drying step is preferably provided continuously or discontinuously. Drying is performed by hot air, infrared rays, far infrared rays, or the like.
As an automatic processor that is preferably used in the method of preparing a lithographic printing plate according to the present disclosure, an apparatus having a developing unit and a drying unit is used. After gumming, drying is performed in a drying section to obtain a lithographic printing plate.

Further, for the purpose of improving the printing durability, the printing plate after development can be heated under very strong conditions. The heating temperature is preferably in the range of 200C to 500C. If the temperature is low, a sufficient image strengthening effect cannot be obtained, and if it is too high, problems such as deterioration of the support and thermal decomposition of the image area may occur.
The lithographic printing plate thus obtained is set on an offset printing machine, and is suitably used for printing a large number of sheets.

Hereinafter, the present invention will be described in detail with reference to examples. Materials, usage amounts, ratios, processing contents, processing procedures, and the like shown in the following examples can be appropriately changed without departing from the spirit of the embodiment of the present invention. Therefore, the scope of the embodiment of the present invention is not limited to the specific examples described below. In this example, “parts” and “%” mean “parts by mass” and “% by mass” unless otherwise specified.
Hereinafter, compound PU-1 to compound PU-20, compound PT-1 to compound PT-20, compound PC-1 to compound PC-14, compound (I) -1 to compound (I) -14, and compound in the Examples. (II) -1 to compound (II) -18 and compound (III) -1 to compound (III) -20 are the compound PU-1 to compound PU-20 and compound PT-1 to compound PU-20 shown in the above specific examples, respectively. Compound PT-20, Compound PC-1 to Compound PC-14, Compound (I) -1 to Compound (I) -14, Compound (II) -1 to Compound (II) -18 and Compound (III) -1 It represents the same compound as compound (III) -20.

<Synthesis of Compound PU-1 to Compound PU-20, Compound PT-1 to Compound PT-20, Compound PC-1 to Compound PC-14>
Compound PU-1 to compound PU-20, compound PT-1 to compound PT-20, and compound PC-1 to compound PC-14 were synthesized with reference to the method described in WO 2016/1333072.

<Synthesis of Compound (I) -1 to Compound (I) -14, Compound (II) -1 to Compound (II) -18, and Compound (III) -1 to Compound (III) -20>
Compound (I) -1 to Compound (I) -14, Compound (II) -1 to Compound (II) -18 and Compound (III) -1 to Compound (III) -20 correspond to the structure of each compound. It was synthesized by the method described above using a combination of a sulfonic acid halide compound and an amine compound.

<Preparation of support>
An aluminum alloy plate of material 1S having a thickness of 0.3 mm was subjected to the following processes (Aa) to (Ak) to produce a lithographic printing plate support. Note that a water-washing treatment was performed between all the processing steps, and after the water-washing treatment, the liquid was drained with a nip roller.
(Aa) Mechanical surface roughening treatment (brush grain method)
While supplying a suspension of pumice (specific gravity 1.1 g / cm ³ ) as a polishing slurry liquid to the surface of the aluminum plate, a mechanical roughening treatment was performed with a rotating bundling brush.
The median diameter (μm) of the abrasive was 30 μm, the number of brushes was 4, and the rotation speed (rpm) of the brush was 250 rpm. The material of the bundling brush was nylon 6,10, and the brush bristles had a diameter of 0.3 mm and a bristle length of 50 mm. The brush was planted so as to be dense by making holes in a stainless steel cylinder of φ300 mm. The distance between the two support rollers (φ200 mm) below the bundling brush was 300 mm. The bundling brush was pressed until the load of the drive motor for rotating the brush became 10 kW plus the load before pressing the bundling brush against the aluminum plate. The direction of rotation of the brush was the same as the direction of movement of the aluminum plate.
(Ab) Alkali etching treatment The aluminum plate obtained above was subjected to an etching treatment by spraying a caustic soda aqueous solution having a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass at a temperature of 70 ° C with a spray tube. . Thereafter, water washing by spraying was performed. The amount of aluminum dissolved was 10 g / m ² .
(Ac) Desmutting treatment in acidic aqueous solution Next, desmutting treatment was performed in nitric acid aqueous solution. As a nitric acid aqueous solution used for the desmut treatment, a waste liquid of nitric acid used for electrochemical surface roughening in the next step was used. The liquid temperature was 35 ° C. The desmut liquid was sprayed with a spray to perform a desmut treatment for 3 seconds.
(Ad) Electrochemical surface-roughening treatment Electrochemical surface-roughening treatment was continuously performed using an alternating voltage of 60 Hz for nitric acid electrolysis. The electrolyte used at this time was an electrolyte prepared by adding aluminum nitrate to an aqueous solution of nitric acid 10.4 g / L at a temperature of 35 ° C. and adjusting the aluminum ion concentration to 4.5 g / L. As the AC power supply waveform, the time tp from the time when the current value reaches zero to the peak reaches 0.8 msec, the duty ratio is 1: 1 and the trapezoidal rectangular wave AC is used. Processing was performed. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the peak value of the current, and 5% of the current flowing from the power supply was shunted to the auxiliary anode. Amount of electricity (C / dm ²⁾ the aluminum plate was 185C / dm ² as the total quantity of electricity when the anode. Thereafter, water washing by spraying was performed.
(A-e) Alkali etching treatment The aluminum plate obtained above was subjected to etching treatment by spraying a sodium hydroxide aqueous solution having a sodium hydroxide concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass at a temperature of 50 ° C with a spray tube. . Thereafter, water washing by spraying was performed. The amount of aluminum dissolved was 0.5 g / m ² .
(Af) Desmutting treatment in acidic aqueous solution Next, desmutting treatment was performed in sulfuric acid aqueous solution. As the sulfuric acid aqueous solution used for the desmut treatment, a solution having a sulfuric acid concentration of 170 g / L and an aluminum ion concentration of 5 g / L was used. The liquid temperature was 30 ° C. The desmut liquid was sprayed with a spray to perform a desmut treatment for 3 seconds.
(Ag) Electrochemical surface-roughening treatment Electrochemical surface-roughening treatment was continuously performed using an alternating voltage of 60 Hz of hydrochloric acid electrolysis. As the electrolytic solution, an electrolytic solution was used in which aluminum chloride was added to an aqueous solution of 35 g of hydrochloric acid and 6.2 g / L of hydrochloric acid to adjust the aluminum ion concentration to 4.5 g / L. Electrochemical surface-roughening treatment was performed using a carbon electrode as a counter electrode using a trapezoidal rectangular wave alternating current with a time tp until the current value reaches a peak from zero to 0.8 msec, a duty ratio of 1: 1. Ferrite was used for the auxiliary anode.
The current density was 25A / dm ² at the peak of electric current amount of hydrochloric acid electrolysis (C / dm ²⁾ the aluminum plate was 63C / dm ² as the total quantity of electricity when the anode. Thereafter, water washing by spraying was performed.
(Ah) Alkaline Etching Treatment The aluminum plate obtained above was subjected to etching treatment by spraying a sodium hydroxide aqueous solution having a sodium hydroxide concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass at a temperature of 50 ° C. with a spray tube. . Thereafter, water washing by spraying was performed. The amount of aluminum dissolved was 0.1 g / m ² .
(Ai) Desmutting treatment in acidic aqueous solution Next, desmutting treatment was performed in sulfuric acid aqueous solution. Specifically, a desmut treatment was performed at a liquid temperature of 35 ° C. for 4 seconds using a waste liquid generated in the anodizing treatment step (5 g / L of aluminum ions dissolved in a 170 g / L aqueous solution of sulfuric acid). The desmut liquid was sprayed with a spray to perform a desmut treatment for 3 seconds.
(A-j) Anodizing treatment Anodizing apparatus of the two-stage power supply electrolytic treatment method (first and second electrolytic unit lengths 6 m each, first and second power supply unit lengths 3 m each, first and second supply electrode unit lengths 2. 4m) to perform anodizing treatment. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolytic units. Each of the electrolytes had a sulfuric acid concentration of 50 g / L (containing 0.5% by mass of aluminum ions) and a temperature of 20 ° C. Thereafter, water washing by spraying was performed.
(A-k) Silicate treatment In order to ensure the hydrophilicity of the non-image area, silicate treatment was performed by dipping for 7 seconds at 50 ° C. using a 2.5% by mass aqueous solution of No. 3 sodium silicate. The amount of Si attached was 10 mg / m ² . Thereafter, water washing by spraying was performed.

<Formation of undercoat layer>
The undercoat layer coating solution 1 shown below was coated on the support prepared as described above, and dried at 80 ° C. for 15 seconds to provide an undercoat layer to obtain a support. The coating amount after drying was 15 mg / m ² .
[Undercoat layer coating liquid 1]
-The following copolymer having a weight average molecular weight of 28,000: 0.3 parts-Methanol: 100 parts-Water: 1 part

  In the above chemical formulas, parenthesized subscripts indicate the content (% by mass) of each structural unit.

<Formation of recording layer>
The coating solution (I) for forming a lower layer having the following composition was applied to the obtained support with a wire bar, and then dried in a drying oven at 150 ° C. for 40 seconds to obtain an application amount of 1.0 g / m ² . And a lower layer was provided. After the lower layer was provided, the upper layer-forming coating liquid composition (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 lithographic printing plate precursor having a coating amount of the lower layer and the upper layer of 1.2 g / m ² .

[Coating liquid composition for forming lower layer (I)]
-Alkali-soluble resin described in Tables 5 to 6: 3.5 parts-Specific compound described in Tables 5 to 6: 0.2 parts-Infrared absorber (IR dye (I): the following structure): 0. 2 parts4,4'-bishydroxyphenylsulfone: 0.3 partstetrahydrophthalic acid: 0.4 partsp-toluenesulfonic acid: 0.02 parts2,4,6-tris (hexyloxy) benzene Diazonium 5-benzoyl-4-hydroxy-2-methoxybenzosulfonate: 0.12 parts-Ethyl violet counter ion changed to 6-hydroxynaphthalenesulfonic acid: 0.15 parts-Fluorinated surfactant ( Megafac F-780, Dainippon Ink and Chemicals): 0.07 part ・ Methyl ethyl ketone: 30 parts ・ 1-Methoxy-2-butyrolactone: 15 parts ・ γ-butyrolactone: 15 parts

[Coating liquid composition for forming upper layer (II)]
-Novolak resin (m-cresol / p-cresol / phenol = 3/2/5, Mw 8,000): 0.68 part-Infrared absorbing agent (IR dye (I): the above structure): 0.045 part-Fluorine -Based surfactant (MegaFac F-780, manufactured by Dainippon Ink and Chemicals, Inc.): 0.03 parts ・ Methyl ethyl ketone: 15.0 parts ・ 1-Methoxy-2-propanol: 30.0 parts ・ 1- ( 4-Methylbenzyl) -1-phenylpiperidinium 5-benzoyl-4-hydroxy-2-methoxybenzenesulfonate: 0.01 part

  The following evaluation was performed using the obtained lithographic printing plate precursors of Examples and Comparative Examples, and the results are shown in Tables 5 and 6 below.

<Evaluation of dissolution resistance of image area and development time of non-image area>
A test pattern was image-drawn on the positive type lithographic printing plate precursor in each of the examples and comparative examples at a beam intensity of 9 W and a drum rotation speed of 150 rpm using a Trendsetter VX made by Creo.
Thereafter, it is immersed in a developing bath charged with a developing solution XP-D manufactured by FUJIFILM Corporation (diluted and having an electric conductivity of 42 mS / cm), and the dissolution of the image area at a developing temperature of 28 ° C. is started. The time and the time required for developing the non-image area were measured.
The time required for the image portion to start dissolving was the time required for the measured value of the optical density (OD value) in the image portion to decrease by 0.05 from the measured value of the optical density in the image portion before the development processing. The immersion time when the difference between the measured value of the optical density in the non-image area and the measured value of the optical density of the aluminum support was 0.02 or less was defined as the non-image area development time. In each case, the optical density was measured using a spectrophotometer SpectroEye manufactured by GretagMacbeth.
The longer the time until the start of dissolution of the image portion, the better the resistance to an alkaline aqueous solution. The shorter the non-image portion development time, the better the solubility of the non-image portion in an alkaline aqueous solution, and the better the aqueous alkaline solution developability (highlight reproducibility). Therefore, in the positive type lithographic printing plate precursor, the image portion melting start time is long, the non-image portion developing time is short, and the larger the difference between the image portion melting start time and the non-image portion developing time is, the more excellent the developability is. To evaluate.
Furthermore, it can be said that the shorter the non-image portion development time is, the more excellent the suppression of the above-mentioned residual color is.
The results are shown in Tables 5 and 6.

<Evaluation of printing durability>
A test pattern was image-drawn on the positive type lithographic printing plate precursor in each of the examples and comparative examples using a Trendsetter manufactured by Creo Corporation at a beam intensity of 9 W and a drum rotation speed of 150 rpm. Thereafter, using a PS processor LP940H manufactured by Fuji Photo Film Co., Ltd. charged with a developer XP-D manufactured by Fuji Film Co., Ltd. (diluted to a conductivity of 43 mS / cm), a developing temperature of 30 ° C. and a developing time Was developed for the non-image area developing time shown in Tables 5 and 6. This was continuously printed using a printing machine Lithrone manufactured by Komori Corporation. As the ink, a Toyo special ink ink containing calcium carbonate was used as a model of a low-grade material. At this time, how many sheets can be printed while maintaining a sufficient ink density was visually measured to evaluate the printing durability. The larger the number, the better the printing durability. The results are shown in Tables 5 and 6.

<Evaluation of chemical resistance>
The positive planographic printing plate precursors in each of the examples and comparative examples were exposed, developed and printed in the same manner as in the evaluation of the printing durability. At this time, every time 5,000 sheets were printed, a step of wiping the plate surface with a cleaner (manufactured by FUJIFILM Corporation, multi-cleaner) was added, and the chemical resistance was evaluated. At this time, the printing durability was 95% or more and 100% or less of the above-mentioned number of printings: 1, 2 to 80% or more and less than 95%, and 3 to 60% or more and less than 80%. , Less than 60% was set to 4. Even when a step of wiping the plate surface with a cleaner is added, the smaller the change in the printing durability index, the better the chemical resistance. The results are shown in Tables 5 and 6 below.

<Evaluation of ink adhesion>
The positive type lithographic printing plate precursor in each of the examples and comparative examples was loaded into a plate material supply device, continuously and automatically exposed, developed using the above developer, and discharged to a stocker. The resolution at the time of exposure was 2,400 dpi (dots per inch, 1 inch = the number of dots per 2.54 cm) and 175 lines, and the halftone dot was changed in the range of 0.5 to 99.5%. The obtained lithographic printing plate was printed using an R201 type printing machine manufactured by Man Roland Co., Ltd., using Dicure Abilio manufactured by DIC Graphics Co., Ltd. as an ink. It was visually confirmed that no printing was performed, and the number of prints required up to that time was used as an index of ink adhesion. The smaller the number of prints required for ink deposition, the better the ink deposition. The evaluation was performed according to the following evaluation criteria, and the evaluation results are shown in Tables 5 and 6.
〔Evaluation criteria〕
1: The number of printed sheets required for depositing the ink was 15 or less.
2: The number of prints required for ink deposition exceeded 15 and was 30 or less.
3: The number of prints required for ink deposition exceeded 30 sheets.

  The structures of C-1, C-2, C-3 and C-4 used in Comparative Examples 1 to 3 are as follows. In the structures below, Me represents a methyl group, and the numerical value at the lower right of the parenthesis represents a molar ratio.

  From the results of Tables 5 and 6, it can be seen that the positive type lithographic printing plate obtained by using the positive type photosensitive resin composition according to the present disclosure is excellent in chemical resistance and ink adhesion.

Claims (8)

A compound having a molecular weight of 5,000 or less represented by the formula I, the formula II or the formula III,
An alkali-soluble resin, and
A positive photosensitive resin composition containing an infrared absorber.

In Formula I, R ¹ represents a monovalent organic group, R ² represents a hydrogen atom or a monovalent organic group, and at least one of R ¹ and R ² contains an oxyalkylene group and is included in Formula I. The structure represented by SO ₂ NH— is one.
In Formula II, R ³ each independently represents a monovalent organic group, R ⁴ represents an n-valent organic group, at least one of R ³ and R ⁴ contains an oxyalkylene group, and n represents 2 to 4 And the number of structures represented by —SO ₂ NH— in Formula II is the same as n.
In Formula III, R ⁵ each independently represents a hydrogen atom or a monovalent organic group, R ⁶ represents an m-valent organic group, and at least one of R ⁵ and R ⁶ contains an oxyalkylene group; represents an integer of 2 to 4, the number of the structure represented by _-SO 2 NH- contained in the formula III is equal to the m. The positive photosensitive resin according to claim 1, wherein the oxyalkylene group contained in the compound having a molecular weight of 5,000 or less represented by Formula I, Formula II or Formula III is a group represented by Formula IV below. Composition.

In the formula IV, R ⁷ each independently represents an alkylene group having 2 to 6 carbon atoms, and n1 represents an integer of 1 or more. The positive photosensitive resin composition according to claim 2, wherein the group represented by the formula IV is a group represented by the following formula V.

In Formula V, R ^{8 to} R ¹¹ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and n1 represents an integer of 1 or more.   The positive photosensitive resin composition according to any one of claims 1 to 3, wherein the compound having a molecular weight of 5,000 or less represented by Formula I, Formula II or Formula III contains an aromatic ring structure. On a support having a hydrophilic surface,
A positive planographic printing plate precursor comprising an image recording layer containing the positive photosensitive resin composition according to claim 1.   The support according to claim 5, further comprising an image recording layer having a lower layer and an upper layer in this order on the support having the hydrophilic surface, wherein the positive photosensitive resin composition is contained in at least one of the lower layer and the upper layer. The positive-working lithographic printing plate precursor described.   The positive lithographic printing plate precursor according to claim 5 or 6, further comprising an undercoat layer between the support having the hydrophilic surface and the image recording layer. An exposure step of image-exposing the positive-working lithographic printing plate precursor according to any one of claims 5 to 7, and
A method for preparing a lithographic printing plate, comprising, in this order, a developing step of developing the exposed positive-working lithographic printing plate precursor using an alkaline aqueous solution having a pH of 8.5 to 13.5.