JP2005062747A - Platemaking method for lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a platemaking method for a lithographic printing plate, the method which can be employed for platemaking of a positive lithographic printing original plate for IR laser light for direct platemaking by an automatic developing apparatus, and by which the quality of a lithographic printing plate can be kept constant and a uniform image can be continuously formed. <P>SOLUTION: In the platemaking method for a lithographic printing plate, a lithographic printing original plate having a positive photosensitive layer comprising a resin soluble with an alkaline solution and a photothermal converting substance on a supporting body is exposed and then subjected to platemaking by using an automatic developing apparatus equipped with at least a developing section, a water cleaning section, a finisher section and a carrying member for the lithographic printing original plate. In the automatic developing apparatus, a rotating rubbing member is disposed in at least one of the exit of the developing section, the entrance of the water cleaning section and the exit of the water cleaning section in such a manner that the rubbing member is in contact with the photosensitive layer of the lithographic printing original plate and the rotation speed of the rotating rubbing member is different from the carrying speed of the lithographic printing original plate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for making a lithographic printing plate. More specifically, the present invention relates to a plate making method of a positive lithographic printing plate for infrared laser for so-called direct plate making which can be directly made from a digital signal of a computer or the like.

In recent years, the development of lasers has been remarkable. In particular, solid lasers and semiconductor lasers having a light emitting region from the near infrared region to the infrared region have been increasing in output and size. Therefore, these lasers are very useful as an exposure light source when making a plate directly from digital data such as a computer.
The positive lithographic printing plate precursor for infrared lasers that uses an infrared laser having a light emitting region in the infrared region as an exposure light source must have a binder resin that is soluble in an aqueous alkali solution and an IR dye that absorbs light and generates heat. A lithographic printing plate precursor as a component (hereinafter sometimes simply referred to as “PS plate”).

  When an infrared laser is exposed to a positive lithographic printing plate precursor for infrared laser, an IR dye or the like in the positive lithographic printing plate precursor for infrared laser is interacted with a binder resin in an unexposed portion (image portion). It acts as a dissolution inhibitor that substantially reduces the solubility of the binder resin. On the other hand, in the exposed portion (non-image portion), the IR dye or the like absorbs light and generates heat, so that the interaction between the IR dye and the binder resin is weakened. Therefore, at the time of development, the exposed portion (non-image portion) is dissolved in the alkaline developer, and a lithographic printing plate is formed.

  However, such positive lithographic printing plate precursors for infrared lasers have the following problems because the latitude with respect to the activity of the developer is narrower than that of positive lithographic printing plate precursors made by UV exposure. . That is, when the activity of the developer is increased, there are problems that the image area is scratched and the density and printing durability of the image area are decreased. In addition, when the activity of the developer is lowered, a development defect is easily caused and a photosensitive layer having a size of about 0.2 to 3.0 mm remains, or a photosensitive layer component is reattached in a washing portion. was there.

The above-mentioned problem is caused by the essential difference in the plate-making mechanism between a positive lithographic printing plate precursor for infrared laser and a positive lithographic printing plate precursor made by UV exposure as described below.
A positive lithographic printing plate precursor for making a plate by UV exposure comprises an alkaline aqueous solution-soluble binder resin and onium salts and quinonediazide compounds as essential components. When such a positive lithographic printing plate precursor is exposed, the onium salts and quinonediazide compounds act as dissolution inhibitors in the non-exposed portion (image portion) as in the case of the infrared laser positive lithographic printing plate precursor. However, in the exposed portion (non-image portion), unlike the case of the positive lithographic printing plate precursor for infrared laser, it is decomposed by light to generate an acid and acts as a dissolution accelerator for the binder resin. Therefore, in a positive lithographic printing plate precursor that makes a plate by UV exposure, the difference in solubility in an alkaline developer between an exposed area and an unexposed area is very large.
On the other hand, in the positive lithographic printing plate precursor for infrared laser, at the time of exposure, the interaction between the IR dye and the binder resin is weakened in the exposed area (non-image area), but the IR dye is a binder dissolution accelerator. Therefore, the difference in solubility between the non-exposed portion and the exposed portion is small.

For the above reasons, in order to continuously form stable images using a lithographic printing plate precursor having a narrow latitude with respect to the activity of the developer, such as a positive lithographic printing plate precursor for infrared laser, Process management is very difficult.
Usually, when developing a positive photosensitive lithographic printing plate precursor for an infrared laser, an automatic developing device having a replenishment mechanism that keeps the developer sensitivity as constant as possible is used. The replenishment mechanism adds a highly active replenisher in order to prevent the pH of the developer from being lowered and the developability from being lowered due to the development processing of the plate and the absorption of CO ₂ .
Specifically, in a normal PS plate processing system, i) a method of managing conductivity or AC impedance and adding a replenisher so that the impedance is constant (see, for example, Patent Documents 1 and 2). Ii) A method of periodically adding a predetermined amount of replenisher every time the number of development processing of a lithographic printing plate precursor reaches a certain number, or after a certain processing time has elapsed (for example, Patent Documents 3 and 4). See) has been proposed.

However, in the case where each of the above-described methods is applied, if the developability is increased, the image portion may be scratched. Further, there is a problem that the density of the image area is lowered and the printing durability is lowered. On the other hand, when developability deteriorates, if dust, dust, oil components, etc. adhere to the surface of the photosensitive layer at the developing tank entrance in the automatic developing device, a photosensitive layer having a size of about 0.2 to 3.0 mm is formed after development. There is a problem that the photosensitive layer components remain or remain in the water washing section in the automatic developing apparatus.
Further, i) In the method of managing by conductivity, when the number of development processing increases and a lot of the composition of the photosensitive layer is dissolved, the pH is different and the developability is different even at the same conductivity value as at the start. There is a problem of coming.

In addition, in the method of ii) periodically adding a predetermined amount of replenisher, since the replenishment amount per unit area of the plate is defined, the composition amount of the photosensitive layer that dissolves in the developer varies depending on the image area. The state of the developing solution slightly changes due to factors such as a difference in the amount of CO ₂ absorbed over time depending on the installation environment (temperature, humidity, CO ₂ concentration, etc.) of the developing device. For this reason, in the method of periodically adding a predetermined amount of replenisher, a photosensitive layer having a size of about 0.2 to 3.0 mm is likely to remain, and the photosensitive layer components are likely to be reattached in the water-washed portion. With this replenishment amount setting, it was difficult to continuously obtain a general-purpose uniform lithographic printing plate.

  Usually, in the case of a normal lithographic printing plate precursor using UV exposure, the above point is not a big problem because the latitude is wide. However, since the positive type lithographic printing plate precursor for infrared laser has a narrow latitude as described above, the image forming property greatly fluctuates due to the change in the activity of the developer, and the quality problem of the lithographic printing plate Cause easily.

However, it is a plate making method of a general-purpose positive lithographic printing plate precursor for an infrared laser, and the plate making method capable of effectively preventing the remaining of the photosensitive layer as described above and the re-adhesion of the photosensitive layer component in the water washing portion, It has not been found yet. In particular, these improvements are strongly desired for plate making of a lithographic printing plate precursor having a photosensitive layer in which the remaining of the photosensitive layer and re-adhesion of the photosensitive layer components in the water-washed portion occur remarkably during plate making. is the current situation
JP-A 64-21451 JP-B-2-35978 JP 2000-105465 A JP-A-6-43661

An object of the present invention is to solve the above problems and achieve the following object.
That is, the present invention can be applied to plate making by an automatic developing device for a positive lithographic printing plate precursor for infrared laser for direct plate making, and can maintain a constant quality of the lithographic printing plate and continuously form a uniform image. An object is to provide a printing plate making method.

  As a result of the study, the present inventors have at least provided a rotating rubbing member at a predetermined position of an automatic developing device including a developing unit, a water washing unit, a finisher unit, and a transport member for a planographic printing plate precursor. It has been found that the above-mentioned problems can be solved by controlling the rotational speed (peripheral speed) of the rotating rubbing member, which is disposed so as to be in contact with the photosensitive layer, and has completed the present invention.

That is, the plate making method of the lithographic printing plate according to the present invention comprises a lithographic printing plate precursor having a positive photosensitive layer containing an alkaline aqueous solution-soluble resin and a photothermal conversion substance on a support, after exposure. A lithographic printing plate making method using an automatic developing device comprising a developing section, a water washing section, a finisher section, and a transport member for a lithographic printing plate precursor,
In the automatic developing apparatus, a rotating rubbing member is disposed at least at one of the outlet of the developing unit, the inlet of the washing unit, and the outlet of the washing unit so as to contact the photosensitive layer of the lithographic printing plate precursor. Set up
The rotational speed of the rotating rubbing member is different from the transport speed of the planographic printing plate precursor.

  The plate making method of the lithographic printing plate of the present invention is applied to plate making by an automatic developing device of a positive lithographic printing plate precursor for infrared laser for direct plate making, suppresses the generation of a residual film of the photosensitive layer, and recycles the components of the photosensitive layer. By preventing the adhesion, the quality of the lithographic printing plate can be kept constant and a uniform image can be continuously formed.

  Hereinafter, the plate making method of the planographic printing plate of the present invention (hereinafter referred to as “plate making method” as appropriate) will be described in detail.

The lithographic printing plate making method of the present invention is a plate making method applied to plate making by an automatic developing device for a positive lithographic printing plate precursor.
An automatic developing device to which the present invention is applied is an automatic developing device including at least a developing unit, a water washing unit, a finisher unit, and a transport member for a lithographic printing plate precursor. Rotating rubbing members (hereinafter referred to as “rubbing members” as appropriate) at least at one of the three outlets, the outlet of the washing section and the outlet of the washing section, are sensitized to the lithographic printing plate precursor. The main feature is that the rotational speed (peripheral speed) of the rotating rubbing member is controlled to be different from the transport speed of the planographic printing plate precursor.
Here, the exit of the developing unit refers to a location where the lithographic printing plate precursor is discharged in the developing unit of the automatic developing device, and the entrance of the washing unit refers to a location where the lithographic printing plate precursor enters in the washing unit. The outlet of the section refers to a location where the lithographic printing plate precursor is discharged in the water washing section.
Note that the automatic developing device may include other parts than the developing unit, the water washing unit, and the finisher unit.

  In the present invention, a rotating brush roller or a Morton roller is used as the rotating rubbing member disposed at a predetermined position of the automatic developing device. The rubbing member performs a step of removing unnecessary photosensitive layer or redeposits by scraping the rotating brush roller or Molton roller with the photosensitive layer surface in contact with the surface.

  The Molton roller is a rubber roller or metal roller wrapped with a non-woven fabric such as felt having a thickness of about 2 to 5 mm, which is a rubbing member. As the nonwoven fabric used for the rubbing part, a material mainly composed of cotton is used. As the fibers constituting the nonwoven fabric, those having a thickness of about 5 to 15 μm and a length of about 1 to 3 mm are common. In the following, when referring to either or both of the rotating brush roller and the Morton roller, they may be simply referred to as “rubbing roller”.

  As the condition of the rubbing member, the material, thickness, length, flocking density, material of the non-woven fabric part used for the Molton roller, the thickness, the thickness of the fibers constituting the non-woven fabric, Conditions such as length and other characteristics of brush roller or molton roller, outer diameter, number of rubbing roller to be used, contact width between rubbing roller and photosensitive layer, rotating speed (peripheral speed) of rubbing roller, rotation condition, etc. Can be appropriately selected in consideration of the removability of the non-image area of the photosensitive layer and the influence on the image area (that is, the scratch resistance of the plate surface, etc.).

  The disposition position of the rubbing roller as the rotating rubbing member is at least one of the three positions of the developing unit outlet, the water washing unit inlet, and the water washing unit outlet in the automatic developing apparatus. Thus, at the end of the development process or before and after the washing process, the rotating rubbing member comes into contact with the photosensitive layer of the lithographic printing plate precursor, so that unnecessary photosensitive layers or re-adhered substances can be easily removed. it can.

In addition, the rotational speed (peripheral speed) of the rotating rubbing member in the present invention must be different from the transport speed of the lithographic printing plate precursor, and is preferably different in the range of 0.5 to 50%, preferably 1 It is more preferable that the difference is in the range of ˜40%, and it is further preferable that the difference is in the range of 1 to 30%.
If the rotational speed of the rotating rubbing member and the transport speed of the lithographic printing plate precursor are the same, a photosensitive layer having a size of about 0.2 to 3.0 mm remains, or the photosensitive layer components are reattached in the washing section. There are things to do.
Here, the transport speed of the lithographic printing plate precursor in the present invention refers to the transport speed of the lithographic printing plate precursor in the automatic developing device or the transport speed of the lithographic printing plate after development.

In the present invention, the “contact width between the rubbing member and the photosensitive layer of the lithographic printing plate precursor (plate)” means that the rubbing member and the plate in a state where the rotation of the rubbing member is stationary and the conveyance of the plate is stationary The contact width. As a measuring method, the following methods A to C can be adopted.
A: An ultra-low pressure prescale is placed on the surface of the plate, and the rubbing member is dropped from 0.1 m above to measure the discolored width.
B: Wet the surface of the rubbing member with water, drop it from the upper 0.1 m, and measure the width of the water on the plate.
C: The rubbing member and the plate are brought into contact with each other, and the rubbing member is rotated at that position to measure the width at which the photosensitive layer of the plate has changed color.

  The contact width between the rubbing member and the lithographic printing plate precursor in the present invention is preferably in the range of 0.5 to 6.0 mm, more preferably in the range of 1.0 to 5.0 mm, and still more preferably. , 2.0 to 4.0 mm. When the contact width between the rubbing member and the lithographic printing plate precursor is within this range, the size is about 0.2 to 3.0 mm without causing a decrease in density of the image area, a decrease in printing durability, and generation of scratches on the image area. It is possible to prevent the photosensitive layer from remaining or the photosensitive layer components from re-adhering in the water-washed portion.

Hereinafter, an automatic developing apparatus to which the lithographic printing plate making method of the present invention is applied will be described with reference to FIG. Here, FIG. 1 is a schematic sectional view showing an exemplary embodiment of an automatic developing apparatus to which the lithographic printing plate making method of the present invention is applied.
The automatic developing device 10 performs development, rinsing, and finishing of the planographic printing plate precursor (plate material) 12 on which an image is recorded by an infrared laser exposure device (not shown).

First, an outline of the automatic developing apparatus 10 will be described.
The automatic developing apparatus 10 includes a developing unit 18, a water washing unit 24, a finisher unit 26 that applies a gum to the plate material 12 and performs a desensitizing treatment, and a drying unit 16 that dries the plate material 12. In addition, a pair of squeezing rollers 40 (40a and 40b) and a pair of conveying rollers which can be rotating rubbing members are provided at three locations of the outlet of the developing unit 18, the inlet of the water washing unit 24, and the outlet of the water washing unit 24. 54 (54a and 54b) and a pair of transport rollers 56 (56a and 56b) are respectively disposed.
The developing unit 18 includes a developing tank 14, the washing unit 24 includes a washing tank 28, and the finisher unit 26 includes a gum solution tank 30.

  Further, the outer panel 20 on the developing unit 18 side is provided with a slit-like insertion port 22 into which the plate material 12 is inserted. A pair of transport rollers 32 are disposed inside the insertion port 22, and the plate material 12 inserted from the insertion port 22 is nipped and transported by the transport rollers 32, and has a predetermined angle with respect to the horizontal direction. Is sent out toward the developing tank 14.

The developing tank 14 has a substantially inverted mountain shape with the upper part opened and the bottom center part protruding downward. In the developing tank 14, the upstream side is along the conveying direction of the plate material 12. In order, a pair of conveying rollers 34, rubbing roller 36, 38, and a pair of squeezing rollers 40 are disposed.
The transport roller 32, the transport roller 34, the rubbing roller 36, 38, and the squeeze roller 40 are rotated by a driving mechanism (not shown). Among these, the conveyance rollers 32 and 34 mainly have a function of determining the conveyance speed of the lithographic printing plate precursor or the developed lithographic printing plate.

Further, backup rollers 44 and 46 are disposed opposite to each other with the rubbing portion roller 36 interposed therebetween, and a backup roller 48 is disposed opposite to the rubbing portion roller 36. These backup rollers 44, 46 and 48 are rotatable without being transmitted with a driving force.
In the developing unit 18, the developing solution in the developing tank 14 is sucked through the joint pipe 50 provided on the bottom wall, and enters the developing tank 14 through a discharge port (not shown) formed in the side wall. Then, the developer is circulated and stirred.

  A pair of transport rollers 54 and 56 are disposed above the water washing tank 28 in the water washing section 24 on the downstream side of the developing section 18. These conveying rollers 54 and 56 are rotatably supported by the side plate, and form a conveying path for the plate material 12 fed from the developing unit 18 by transmitting the driving force of the driving means. Here, the conveying rollers 54 and 56 disposed in the washing unit 24 are driven separately from the conveying rollers 32 and 34 so as to be rotated by a driving mechanism that changes the rotation speed of the conveying rollers 32 and 34. It may be controlled by a mechanism.

Further, a spray pipe 58 is disposed between the transport roller 54 and the transport roller 56 so that the jet port faces the transport path. From the spray pipe 58, the washing liquid pumped up from the washing tank 28 is ejected, and the front and back surfaces of the plate 12 are covered with washing water.
The washing liquid ejected from the spray pipe 58 flows to the washing tank after washing the plate material 12.
Here, the rinsing solution in the present invention may show alkalinity when mixed with the developing solution that adheres to the plate material from the developing unit and is carried in. Further, from the viewpoint of stabilization of the plate making, it is possible to add a developer up to about 10% by volume to the washing solution, and such a mixed solution is also included in the washing solution in the present invention. .

  A pair of squeezing rollers 60 is provided above the gum solution layer 30 of the finisher section 26 which is a desensitizing treatment section on the downstream side of the water washing section 24. Then, the plate material 12 sent out by the conveying roller 56 is sent to the squeezing roller 60. On the upstream side of the squeeze roller 60, a spray pipe 62 is disposed in the up-down direction so that the jet port faces the conveyance path. From this spray pipe 62, the gum solution sucked by the pump from the gum solution tank 30 is ejected and applied to the front and back surfaces of the plate material 12.

  Thereafter, the plate material 12 on which the gum solution is uniformly applied by the squeezing roller 60 is guided to the drying unit 16 through a passage opening 66 opened and closed by a shutter 64. In the drying unit 16, the plate material 12 transported and dried by the guide roller 68 and the pair of skewer rollers 70 and 72 is discharged from the discharge port 74 to the outside of the automatic developing device 10.

  In the automatic developing device 10 according to the present invention, when the lithographic printing plate precursor to be subjected to plate making has a photosensitive layer only on one side, and the photosensitive layer faces upward in FIG. In order to prevent the redeposition of the photosensitive layer components, at least one of the squeeze roller 40a, the transport roller 54a, and the transport roller 56a needs to be a rotating rubbing member. In particular, the effect is great when the squeezing roller 40a is a rotating rubbing member, and the effect is further enhanced when the conveying roller 54a or the conveying roller 56a is a rubbing member rotating in addition to the squeezing roller 40a.

  When the lithographic printing plate precursor used in the present invention has photosensitive layers on both sides, a squeezing roller 40b that contacts the back surface of the lithographic printing plate precursor (the surface facing downward in FIG. 1), after development It is preferable that at least one of the transport roller 54b and the transport roller 56b that are in contact with the back surface of the planographic printing plate is a rotating rubbing member. When no photosensitive layer is provided on the back side of the lithographic printing plate precursor, the squeezing roller 40b, the conveying roller 54b, and the conveying roller 56b may be rotating rubbing members or rubber rollers as described later. It may be.

In the present invention, as described above, the rotating speed of the rotating rubbing member is different from the conveying speed of the planographic printing plate precursor (plate material 12).
That is, in the automatic developing device 10 according to the present invention, the automatic developing device 10 is disposed at the exit of the developing unit that functions as a rotating rubbing member as compared with the rotational speed of the transport rollers 32 and 34 that determine the transport speed of the plate material 12. The rotational speed of at least one of the pair of squeezing rollers 40, the transport roller 54 disposed at the entrance of the water washing section 24, and the transport roller 56 disposed at the exit of the water wash section 24 is controlled with a certain difference. Therefore, it is preferable to control the difference appropriately according to the activity of the developer.

  The rotation speeds are adjusted by a pair of squeezing rollers 40 disposed at the outlet of the developing unit, a pair of transport rollers 54 disposed at the inlet of the rinsing unit 24, and an outlet of the rinsing unit 24. May be performed on any one of the pair of transport rollers 56, or may be performed by a combination of the squeeze roller 40 and the transport roller 54, the squeeze roller 40 and the transport roller 56, and the transport roller 54 and the transport roller 56. You may carry out with respect to all these rollers.

  In the present invention, any conveying roller and squeeze roller that are resistant to processing chemicals when not used as a rotating rubbing member can be used. Preferably, silicone rubber, butyl rubber, ethylene / propylene rubber (EPT / EPDM), acrylonitrile / butadiene rubber (NBR), styrene / butadiene rubber (SBR), polybutadiene rubber (BR), chloropyrene rubber (CR), etc. are used. be able to.

Moreover, it is preferable to use what contained a fungicide and an antibacterial agent for such a conveyance roller and an aperture roller. As the fungicides and antibacterial agents, those generally known can be used, but preferably 2- (4-thiazolyl) -benzimidoazole (trade name: Hoxter HP, manufactured by Hokuko Chemical Co., Ltd.) ), Thiazoline of Amorden SK-950 (trade name, manufactured by Daiwa Chemical Co., Ltd.), and vinylazine (trade name: Vinyzene, manufactured by Morton Thiokol Co., Ltd.) can be used.
The addition amount of the fungicide or antibacterial agent is preferably in the range of 0.1 to 5% by mass ratio with respect to the rubber roller.

Next, the planographic printing plate precursor according to the invention will be described.
The lithographic printing plate precursor used in the present invention has a positive photosensitive layer containing an alkaline aqueous solution-soluble resin and a photothermal conversion substance on a support.
Such a positive photosensitive layer contains an alkaline aqueous solution-soluble resin and a light-to-heat conversion substance as essential components, and other commonly used additives are added to the positive photosensitive composition for infrared laser. It may be what you did.

[Alkaline aqueous solution-soluble resin]
As the alkaline aqueous solution-soluble resin in the present invention, any resin can be used as long as it is a resin having an alkaline aqueous solution-soluble property. Among these, (I) a copolymer having a monomer unit represented by the general formula (a) is used. Polymers and (II) alkaline aqueous solution-soluble compounds having a sulfonamide group are preferably used. The compounds (I) and (II) that are preferably used as the aqueous alkali-soluble resin in the present invention will be described.

[(I) Copolymer having monomer units represented by general formula (a)]
The copolymer (I) having a monomer unit represented by the following general formula (a) (hereinafter referred to as a specific copolymer as appropriate), which is preferably used as the aqueous alkaline solution-soluble resin in the present invention, will be described.

  In the general formula (a), R represents a hydrogen atom or an alkyl group. Preferably, they are a hydrogen atom or a C1-C4 alkyl group. X represents an arylene group which may have a substituent or one of the following structures.

ここで、Ａｒは置換基を有していてもよいアリーレン基を表し、Ｙは２価の連結基を表す。

Here, Ar represents an arylene group which may have a substituent, and Y represents a divalent linking group.

  Examples of the divalent linking group represented by Y include an alkylene group, an arylene group, an imide group, and an alkoxy group, which may have a substituent. Examples of these substituents include alkyl groups, hydroxyl groups, alkoxy groups, halogen atoms, phenyl groups, dimethylamino groups, ethylene oxide groups, vinyl groups, o-carboxybenzoyloxy groups, and the like.

  Specific examples of the monomer component represented by the general formula (a) are shown below, but the present invention is not limited thereto.

  As content in the specific copolymer of the monomer component represented by general formula (a), 1-90 mol% is preferable, More preferably, it is 2-50 mol%, Furthermore, it is 5-30 mol%. Within the above range, good developability and a remaining film ratio in the unexposed area can be obtained.

Examples of the copolymerizable monomer component that forms a specific copolymer by copolymerizing with the monomer unit represented by the general formula (a) include (meth) acrylic acid esters, (meth) acrylamide derivatives, and styrene derivatives. This copolymerization monomer component may be composed of one kind selected from (meth) acrylic acid esters, (meth) acrylamide derivatives and styrene derivatives, or may be composed of any two of these. You may be comprised by 3 or more types. That is, for example, a configuration of two types selected from (meth) acrylic acid esters and two types selected from styrene derivatives may be used.
In this specification, acrylic and methacryl are collectively referred to as (meth) acryl. The phrase “including (meth) acrylic acid ester as a copolymerization component” means that at least one of acrylic acid ester and methacrylic acid ester is included. The same applies to (meth) acrylamide derivatives.

As described above, the (meth) acrylic acid ester that can form the copolymerization monomer component is preferably a substituted or unsubstituted alkyl ester or aryl ester. Examples of the alkyl group in the alkyl ester include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n-hexyl group, n-heptyl group, and n-octyl. Group, 2-ethylhexyl group, and the like. In addition, examples of the aryl group in the aryl ester include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, and a benzyl group. The alkyl group or aryl group may be substituted, and examples of the substituent that can be introduced include a hydroxyl group, an alkoxy group, a halogen atom, a phenyl group, a dimethylamino group, an ethylene oxide group, a vinyl group, and an o-carboxybenzoyloxy group. Is mentioned.
Among them, as the (meth) acrylic acid ester, it is more preferable to use methyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, or n-butyl methacrylate.
Moreover, the (meth) acrylic acid ester used by this invention may be used independently, and may be used together 2 or more types.
The content of the (meth) acrylic acid ester in the specific copolymer is preferably 0 to 95 mol%, more preferably 5 to 90 mol%, and further preferably 10 to 80 mol%.

  In addition, the (meth) acrylamide derivative that can be a copolymerization monomer component is not particularly limited as long as it is a (meth) acrylamide derivative, but those represented by the following general formula (b) are preferable.

In general formula (b), R ¹ represents a hydrogen atom or an alkyl group. R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms. However, R ² and R ³ are not both hydrogen atoms.

In general formula (b), R ¹ represents a hydrogen atom or an alkyl group. Preferably they are a hydrogen atom or a C1-C4 alkyl group.
In the general formula (b), examples of the alkyl group having 1 to 10 carbon atoms represented by R ² and R ³ include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an isobutyl group, t- A butyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, etc. are mentioned. Moreover, as a C6-C10 aryl group, a phenyl group, 1-naphthyl group, 2-naphthyl group etc. are mentioned, for example. The alkyl group or aryl group may be substituted, and examples of the substituent that can be introduced include a hydroxyl group, an alkoxy group, a halogen atom, a phenyl group, a dimethylamino group, an ethylene oxide group, a vinyl group, and an o-carboxybenzoyloxy group. Is mentioned. However, R ² and R ³ are not both hydrogen atoms.
Specific examples of the (meth) acrylamide derivative are shown below, but the invention is not limited thereto.

(B-1) Nt-butylacrylamide (b-2) N- (n-butoxymethyl) acrylamide (b-3) Nt-butylmethacrylamide (b-4) N- (1,1-dimethyl) -3-Oxobutyl) acrylamide (b-5) N, N-dimethylmethacrylamide (b-6) N, N-dimethylacrylamide (b-7) N-isopropylacrylamide (b-8) N-methylmethacrylamide (b -9) N-phenylmethacrylamide (b-10) N- [3- (dimethylamino) propyl] acrylamide

In the copolymerization monomer component, the (meth) acrylamide derivatives may be used alone or in combination of two or more.
The content of the (meth) acrylamide derivative in the specific copolymer is preferably 0 to 95 mol%, more preferably 5 to 90 mol%, and further preferably 20 to 80 mol%.

  Furthermore, the styrene derivative that can be a copolymerization monomer component is not particularly limited as long as it is a styrene derivative, but those represented by the following general formula (c) are preferable.

In general formula (c), R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or a substituent. n represents an integer of 1 to 5.
In the general formula (c), the substituent represented by R ⁴ , R ⁵ and R ⁶ is not particularly limited, and examples thereof include an alkyl group, an aryl group, a hydroxyl group, a carboxyl group, and a halogen atom.
Specific examples of the styrene derivative are shown below, but the present invention is not limited thereto.

(C-1) 4-bromostyrene (c-2) β-bromostyrene (c-3) 4-chloro-α-methylstyrene (c-4) 3-chlorostyrene (c-5) 4-chlorostyrene ( c-6) 2,6-dichlorostyrene (c-7) 2-fluorostyrene (c-8) 3-fluorostyrene (c-9) 4-fluorostyrene (c-10) methylstyrene (c-11) vinyl Toluene (c-12) trans-β-methylstyrene

In addition to the above, styrene, vinyl benzoic acid, methyl vinyl benzoate, hydroxymethyl styrene, p-styrene sulfonic acid sodium salt, p-styrene sulfinic acid potassium salt, p-aminomethyl styrene, 1,4-divinylbenzene, etc. Can be mentioned. The styrene derivatives listed above may be used alone or in combination of two or more.
As for content in the specific copolymer of a styrene derivative, 0-95 mol% is preferable, More preferably, it is 5-90 mol%, Furthermore, it is 20-80 mol%.

  The monomer component represented by the above general formula (a) and the specific copolymer obtained from the copolymerization monomer component itself provide preferable physical properties, for example, preferable development tolerance. Other physical properties can be improved or modified by copolymerizing the copolymerizable monomer component. Examples of the physical properties include chemical resistance, printing durability, sensitivity, and developability. Examples of the third copolymerizable monomer component include acrylonitrile, maleimide, vinyl acetate, and N-vinylpyrrolidone.

The weight average molecular weight of the specific copolymer in the present invention is preferably 5,000 to 200,000, more preferably 10,000 to 120,000, and particularly preferably 20 from the viewpoints of film formability and developability. , 80,000.
As a copolymerization method for producing a copolymer, a conventionally known graft copolymerization method, block copolymerization method, random copolymerization method and the like can be used.

In the alkaline aqueous solution-soluble resin of the present invention, the specific copolymer may be used alone or in combination of two or more.
In addition, the specific copolymer may be used in combination with (II) an alkaline aqueous solution-soluble compound having a sulfonamide group, which will be described later, or another alkaline aqueous solution-soluble resin.

[(II) Alkaline aqueous solution-soluble compound having sulfonamide group]
Next, (II) an alkaline aqueous solution-soluble compound having a sulfonamide group (hereinafter, appropriately referred to as a sulfonamide group-containing alkali-soluble compound) will be described.
Examples of the sulfonamide group-containing alkali-soluble compound include polymer compounds obtained by homopolymerizing a polymerizable monomer having a sulfonamide group, or copolymerizing the monomer with another polymerizable monomer. As a polymerizable monomer having a sulfonamide, each molecule has at least one sulfonamide group —NH—SO ₂ — in which at least one hydrogen atom is bonded on a nitrogen atom and one or more polymerizable unsaturated bonds. Examples thereof include polymerizable monomers composed of low molecular compounds. Among them, a low molecular compound having an acryloyl group, an allyl group, or a vinyloxy group, and a substituted or monosubstituted aminosulfonyl group or a substituted sulfonylimino group is preferable.
Among these, preferable examples of the polymerizable monomer having a sulfonamide group include monomers represented by the following general formulas 1 to 5.

In General Formulas 1 to 5, X ¹ and X ² each represent —O— or —NR ¹⁷ —. R ²¹ and R ²⁴ each represent a hydrogen atom or —CH ₃ . R ²² , R ²⁵ , R ²⁹ , R ³² and R ³⁶ each represents an optionally substituted alkylene group having 1 to 12 carbon atoms, a cycloalkylene group, an arylene group or an aralkylene group. R ²³ , R ¹⁷ and R ³³ each represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group which may have a substituent. R ²⁶ and R ³⁷ each represent a C 1-12 alkyl group, cycloalkyl group, aryl group, or aralkyl group that may have a substituent. R ²⁸ , R ³⁰ and R ³⁴ represent a hydrogen atom or —CH ₃ . R ³¹ and R ³⁵ each represents a C 1-12 alkylene group, cycloalkylene group, arylene group or aralkylene group which may have a single bond or a substituent. Y ¹ and Y ² each represent a single bond or —CO—.

  Specifically, m-aminosulfonylphenyl methacrylate, N- (p-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) acrylamide and the like can be preferably used.

  Examples of other monomer components that can be copolymerized with the polymerizable monomer having a sulfonamide group include the compounds listed in the following (m1) to (m12), but are not limited thereto. .

(M1) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate.
(M2) Alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, and glycidyl acrylate.
(M3) Alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate and glycidyl methacrylate.
(M4) Acrylamide, methacrylamide, N-methylol acrylamide, N-ethyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N-nitrophenyl acrylamide, N-ethyl- Acrylamide or methacrylamide such as N-phenylacrylamide.

(M5) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether.
(M6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate.
(M7) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene.
(M8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.
(M9) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene.
(M10) N-vinylpyrrolidone, acrylonitrile, methacrylonitrile and the like.
(M11) Unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide.
(M12) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride and itaconic acid.

  In addition, as a copolymerization method of a sulfonamide group containing alkali-soluble compound, the conventionally known graft copolymerization method, block copolymerization method, random copolymerization method, etc. can be used.

  The sulfonamide group-containing alkali-soluble compound in the present invention preferably has a weight average molecular weight of 2,000 or more and a number average molecular weight of 500 or more. More preferably, the weight average molecular weight is 5,000 to 300,000, the number average molecular weight is 800 to 250,000, and the dispersity (weight average molecular weight / number average molecular weight) is 1.1 to 10. .

  In the aqueous alkali solution-soluble resin of the present invention, the sulfonamide group-containing alkali-soluble compound may be used alone or in combination of two or more.

(Other alkaline aqueous soluble resins)
As the alkali-soluble resin in the present invention, the above-mentioned copolymer (I) having the monomer component represented by the general formula (a) and (II) an alkaline aqueous solution-soluble compound having a sulfonamide group are preferably used. In addition to these, other aqueous alkali-soluble resins (hereinafter sometimes simply referred to as “alkali-soluble resins”) can be used. As other alkaline aqueous solution-soluble resins, conventionally known resins can be used without particular limitation. In particular, a polymer compound having a functional group of any one of (1) a phenolic hydroxyl group and (2) an active imide group is preferable. Specific examples are shown below, but are not limited thereto.

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

  In addition to this, a polymer compound having a phenolic hydroxyl group in the side chain is preferably used as the polymer compound having a phenolic hydroxyl group. As a polymer compound having a phenolic hydroxyl group in the side chain, a polymerizable monomer comprising a low molecular compound having at least one unsaturated bond polymerizable with the phenolic hydroxyl group is homopolymerized, or other polymerizable property is added to the monomer. Examples thereof include a polymer compound obtained by copolymerizing monomers.

Examples of the polymerizable monomer having a phenolic hydroxyl group include acrylamide, methacrylamide, acrylic acid ester, methacrylic acid ester, and hydroxystyrene 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.
Examples of the monomer that can be copolymerized with the polymerizable monomer having a phenolic hydroxyl group include the monomers exemplified as the above (m1) to (m12).

  Such a polymer compound having a phenolic hydroxyl group may be used in combination of two or more. Furthermore, the degeneracy of phenol and formaldehyde having an alkyl group having 3 to 8 carbon atoms as a substituent, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin described in US Pat. No. 4,123,279. A combination may be used in combination.

(2) As an alkali-soluble polymer compound having an active imide group, a polymerizable monomer having at least one unsaturated bond polymerizable with an active imide group in each molecule is homopolymerized, or other polymerization is performed on the monomer. And a high molecular compound obtained by copolymerizing a functional monomer.

Preferable specific examples of the polymerizable monomer having such an active imide group include N- (p-toluenesulfonyl) methacrylamide and N- (p-toluenesulfonyl) acrylamide.
Examples of the monomer that can be copolymerized with the polymerizable monomer having an active imide group include the monomers exemplified as the above (m1) to (m12).

  Further, as other alkaline aqueous solution-soluble resin, two or more of the polymerizable monomer having a sulfonamide group, the polymerizable monomer having a phenolic hydroxyl group, and the polymerizable monomer having an active imide group were polymerized. A polymer compound or a polymer compound obtained by copolymerizing other polymerizable monomers with these two or more kinds of polymerizable monomers can also be used.

When these other aqueous alkali-soluble resins are homopolymers or copolymers of the polymerizable monomers, those having a weight average molecular weight of 2,000 or more and a number average molecular weight of 500 or more are preferred. More preferably, the weight average molecular weight is 5,000 to 300,000, the number average molecular weight is 800 to 250,000, and the dispersity (weight average molecular weight / number average molecular weight) is 1.1 to 10. .
When the other aqueous alkali-soluble resin is a resin such as a phenol formaldehyde resin or a cresol aldehyde resin, a resin having a weight average molecular weight of 500 to 20,000 and a number average molecular weight of 200 to 10,000 is preferable. .

  The content of the aqueous alkali soluble resin in the photosensitive layer of the lithographic printing plate precursor is preferably from 30 to 99% by mass, more preferably from 45 to 95% by mass, based on the total solid content of the photosensitive layer. The range of -90 mass% is still more preferable. When the content of the alkali aqueous solution-soluble resin is less than 30% by mass, the durability of the photosensitive layer is deteriorated, and when it exceeds 99% by mass, it is not preferable in terms of both sensitivity and durability.

[Photothermal conversion material]
The photosensitive layer in the present invention contains a photothermal conversion substance that absorbs light and generates heat. High sensitivity can be achieved by the inclusion of the photothermal conversion substance. As this photothermal conversion substance, an infrared absorbing dye is preferred.
As the infrared absorbing dye according to the present invention, commercially available dyes and known dyes described in literature (for example, “Dye Handbook” edited by the Society of Synthetic Organic Chemistry, published in 1970) can be used. Specific examples include azo dyes, metal complex azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, and cyanine dyes. In the present invention, among these dyes, those that absorb infrared rays of 700 to 1200 nm are particularly preferred because they are suitable for use in lasers that emit infrared light or near infrared light.

  Specific examples of such infrared absorbing dyes include, for example, JP-A-58-125246, JP-A-59-84356, JP-A-60-78787, U.S. Pat. No. 4,973,572. Methine dyes described in JP-A-58-173696, JP-A-58-181690, JP-A-58-194595, etc. 112793, JP-A-58-224793, JP-A-59-48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc. Naphthoquinone dyes, squarylium dyes described in JP-A No. 58-112792, and cyanine dyes described in British Patent No. 434,875. .

Further, near-infrared absorption sensitizers described in US Pat. No. 5,156,938 are also preferably used as dyes, and substituted arylbenzoates described in US Pat. No. 3,881,924 are also preferred. (Thio) pyrylium salts, trimethine thiapyrylium salts described in JP-A-57-142645, JP-A-58-181051, 58-220143, 59-41363, 59-84248, 59 -84249, 59-146063, 59-146061, pyrylium compounds described in JP-A-59-216146, cyanine dyes described in JP-A-59-216146, US Pat. No. 4,283,475 Pentamethine thiopyrylium salts, etc. described in Japanese Patent Publication No. 5-13514 and pyrilium compounds described in JP-A-5-19702 But as the commercially available products, it can be mentioned Eporin Co. Epolight III-178, Epolight III-130, Epolight III-125 and the like.
Another preferred example is a near infrared absorbing dye described in US Pat. No. 4,756,993 as formulas (I) and (II).

  In the photosensitive lithographic printing plate according to the present invention, the infrared absorbing dye is 0.01 to 50% by weight, preferably 0.1 to 50% by weight, particularly preferably 0.1 to 30% by weight, based on the total solid content of the photosensitive layer. Can be added at a ratio of When the added amount of the dye is less than 0.01% by mass, the sensitivity tends to be low, and when it exceeds 50% by mass, the uniformity in the photosensitive layer is lost and the durability of the photosensitive layer tends to deteriorate. .

[Dissolution inhibitor compound]
For the purpose of enhancing the dissolution resistance (inhibition) of the photosensitive lithographic printing plate image area in the developer in the present invention, the photosensitive layer may contain various dissolution inhibiting compounds (inhibitors).
In the present invention, known inhibitors can be used without any particular limitation. Among these, quaternary ammonium salts, polyethylene glycol compounds and the like are preferably used.

The quaternary ammonium salt is not particularly limited, but includes tetraalkylammonium salt, trialkylarylammonium salt, dialkyldiarylammonium salt, alkyltriarylammonium salt, tetraarylammonium salt, cyclic ammonium salt, bicyclic ammonium salt, and particularly Ammonium salts described in Japanese Unexamined Patent Publication No. 2002-229186 are listed. Moreover, the ammonium salt described in Japanese Patent Application No. 2001-398047 is also preferable.
Specifically, tetrabutylammonium bromide, tetrapentylammonium bromide, tetrahexylammonium bromide, tetraoctylammonium bromide, tetralaurylammonium bromide, tetraphenylammonium bromide, tetranaphthylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium iodide , Tetrastearyl ammonium bromide, lauryl trimethyl ammonium bromide, stearyl trimethyl ammonium bromide, behenyl trimethyl ammonium bromide, lauryl triethyl ammonium bromide, phenyl trimethyl ammonium bromide, 3-trifluoromethylphenyl trimethyl ammonium bromide, benzyl trimethyl ammonium bromide , Dibenzyldimethylammonium bromide, distearyldimethylammonium bromide, tristearylmethylammonium bromide, benzyltriethylammonium bromide, benzyltributylammonium iodide, benzyltributylammonium hexafluorophosphate, hydroxyphenyltrimethylammonium bromide, N-methylpyridinium bromide, etc. Is mentioned.

  The addition amount of the quaternary ammonium salt is preferably 0.1 to 50% in terms of solid content with respect to the total solid content of the photosensitive layer, from the viewpoint of the ability to exhibit the dissolution inhibiting effect and the film formability. More preferably, it is -30%.

  Although it does not specifically limit as a polyethyleneglycol compound, The thing of the following structure is mentioned.

^{R 1 - {- O- (R} 3 -O-) m -R 2} n
(R ¹ is a polyhydric alcohol residue or polyhydric phenol residue, R ² is a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylyl group, an aryl group or an aryloyl group which may have a C1-25 substituent. Group R ³ represents an alkylene residue which may have a substituent, m is an average of 10 or more, and n is an integer of 1 to 4.

  Examples of polyalkylene glycol compounds having the above structure include polyethylene glycols, polypropylene glycols, polyethylene glycol alkyl ethers, polypropylene glycol alkyl ethers, polyethylene glycol aryl ethers, polypropylene glycol aryl ethers, polyethylene glycol alkyl aryl ethers. , Polypropylene glycol alkyl aryl ethers, polyethylene glycol glycerin esters, polypropylene glycol glycerin esters, polyethylene sorbitol esters, polypropylene glycol sorbitol esters, polyethylene glycol fatty acid esters, polypropylene glycol fatty acid esters, polyethylene glycolated ethylene Diamines, polypropylene glycolated ethylenediamines, polyethylene glycolated diethylene tri amine, and polypropylene glycol diethylenetriamines.

Specific examples thereof include polyethylene glycol 1000, polyethylene glycol 2000, polyethylene glycol 4000, polyethylene glycol 10000, polyethylene glycol 20000, polyethylene glycol 5000, polyethylene glycol 100000, polyethylene glycol 200000, polyethylene glycol 500000, polypropylene glycol 1500, polypropylene glycol. 3000, polypropylene glycol 4000, polyethylene glycol methyl ether, polyethylene glycol ethyl ether, polyethylene glycol phenyl ether, polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol diphenyl ether Polyethylene glycol lauryl ether, polyethylene glycol dilauryl ether, polyethylene glycol nonyl ether, polyethylene glycol cetyl ether, polyethylene glycol stearyl ether, polyethylene glycol distearyl ether, polyethylene glycol behenyl ether, polyethylene glycol dibehenyl ether, polypropylene glycol methyl ether, polypropylene glycol Ethyl ether, polypropylene glycol phenyl ether, polypropylene glycol dimethyl ether, polypropylene glycol diethyl ether, polypropylene glycol diphenyl ether, polypropylene glycol lauryl ether, polypropylene glycol dilauryl ether, polyethylene glycol Propylene glycol nonyl ether, polyethylene glycol acetyl ester, polyethylene glycol diacetyl ester, polyethylene glycol benzoate ester, polyethylene glycol lauryl ester, polyethylene glycol dilauryl ester, polyethylene glycol nonyl acid ester, polyethylene glycol cetylate ester, polyethylene glycol stearoyl ester, polyethylene Glycol distearoyl ester, polyethylene glycol behenate ester, polyethylene glycol dibehenate ester, polypropylene glycol acetyl ester, polypropylene glycol diacetyl ester, polypropylene glycol benzoate ester, polypropylene glycol dibenzoate ester, Ripropylene glycol laurate, polypropylene glycol dilaurate, polypropylene glycol nonyl ester, polyethylene glycol glycerol ether, polypropylene glycol glycerol ether, polyethylene glycol sorbitol ether, polypropylene glycol sorbitol ether, polyethylene glycolated ethylenediamine, polypropylene glycolated ethylenediamine, Examples include polyethylene glycolated diethylenetriamine, polypropylene glycolated diethylenetriamine, and polyethylene glycolated pentamethylenehexamine.

Further, when the above-described measures for strengthening the inhibition are performed, the sensitivity is lowered. In this case, it is effective to add a lactone compound. This lactone compound is considered to be that when the developer penetrates into the exposed area, the developer and the lactone compound react to generate a new carboxylic acid compound, contributing to dissolution of the exposed area and improving sensitivity.
Although it does not specifically limit as a lactone compound, The compound represented by the following general formula (LI) and general formula (L-II) is mentioned.

In general formula (LI) and general formula (L-II), X ¹ , X ² , X ³ and X ⁴ are ring constituent atoms or atomic groups, which may be the same or different, and are independent of each other. And may have a substituent, and at least one of X ¹ , X ² and X ^{3 in} the general formula (LI) and X ¹ , X ² , X ³ and X in the general formula (L-II) ^At least one of ⁴ has an electron-withdrawing substituent or a substituent substituted with an electron-withdrawing group.
The constituent atom or atomic group of the ring represented by X ¹ , X ² , X ³ and X ⁴ is a nonmetallic atom having two single bonds or an atomic group containing the nonmetallic atom for forming a ring.
A preferred nonmetallic atom or nonmetallic atomic group is an atom or atomic group selected from a methylene group, a sulfinyl group, a carbonyl group, a thiocarbonyl group, a sulfonyl group, a sulfur atom, an oxygen atom, and a selenium atom, and more preferably, It is an atomic group selected from a methylene group, a carbonyl group and a sulfonyl group.

At least one of X ¹ , X ² and X ^{3 in} the general formula (LI) or at least one of X ¹ , X ² , X ³ and X ^{4 in} the general formula (L-II) is an electron withdrawing group Have In the present specification, an electron-withdrawing substituent refers to a group in which Hammett's substituent constant σp takes a positive value. For Hammett's substituent constants, see Journal of Medicinal Chemistry, 1973, Vol. 16, no. 11, 1207-1216 etc. can be referred to. Examples of the electron-withdrawing group in which Hammett's substituent constant σp takes a positive valence include, for example, a halogen atom (fluorine atom (σp value: 0.06), chlorine atom (σp value: 0.23), bromine atom (σp Value: 0.23), iodine atom (σp value: 0.18)), trihaloalkyl group (tribromomethyl (σp value: 0.29), trichloromethyl (σp value: 0.33), trifluoromethyl ( σp value: 0.54)), cyano group (σp value: 0.66), nitro group (σp value: 0.78), aliphatic / aryl or heterocyclic sulfonyl group (for example, methanesulfonyl (σp value: 0) 72)), aliphatic / aryl or heterocyclic acyl groups (for example, acetyl (σp value: 0.50), benzoyl (σp value: 0.43)), alkynyl groups (for example, C≡CH (σp value: 0.23)), Aliphatic Ali Or oxycarbonyl group (for example, methoxycarbonyl (σp value: 0.45), phenoxycarbonyl (σp value: 0.44)), carbamoyl group (σp value: 0.36), sulfamoyl group (σp value) : 0.57), sulfoxide group, heterocyclic group, oxo group, phosphoryl group and the like.

Preferred electron withdrawing groups are amide groups, azo groups, nitro groups, fluoroalkyl groups having 1 to 5 carbon atoms, nitrile groups, alkoxycarbonyl groups having 1 to 5 carbon atoms, acyl groups having 1 to 5 carbon atoms, and carbon numbers. An alkylsulfonyl group having 1 to 9 carbon atoms, an arylsulfonyl group having 6 to 9 carbon atoms, an alkylsulfinyl group having 1 to 9 carbon atoms, an arylsulfinyl group having 6 to 9 carbon atoms, an arylcarbonyl group having 6 to 9 carbon atoms, and thiocarbonyl A group selected from a group, a fluorine-containing alkyl group having 1 to 9 carbon atoms, a fluorine-containing aryl group having 6 to 9 carbon atoms, a fluorine-containing allyl group having 3 to 9 carbon atoms, an oxo group, and a halogen element.
More preferably, a nitro group, a fluoroalkyl group having 1 to 5 carbon atoms, a nitrile group, an alkoxycarbonyl group having 1 to 5 carbon atoms, an acyl group having 1 to 5 carbon atoms, an arylsulfonyl group having 6 to 9 carbon atoms, carbon It is a group selected from an arylcarbonyl group of formulas 9 to 9, an oxo group and a halogen element.
Specific examples of the compounds represented by formulas (LI) and (L-II) are shown below, but the present invention is not limited to these compounds.

The addition amount of the compounds represented by the general formula (LI) and the general formula (L-II) is 0. 0 in terms of solid content with respect to the total solid content of each layer from the viewpoint of curing ability and image formation. 1 to 50% is preferable, and 1 to 30% is more preferable. In addition, since this compound reacts with a developing solution, it is desirable to contact a developing solution selectively.
These lactone compounds may be used alone or in combination. Two or more compounds of the general formula (LI) or two or more compounds of the general formula (L-II) may be used in an arbitrary ratio within the above range.

Further, the photosensitive lithographic printing plate according to the present invention further contains a substance that is thermally decomposable and substantially reduces the solubility of the alkali-soluble resin in a state where it is not thermally decomposed. This is preferable from the viewpoint of further expanding the difference.
The “substance that is thermally decomposable and substantially reduces the solubility of the alkali-soluble resin in a state where it is not thermally decomposed” is not particularly limited, and examples thereof include various onium salts and quinonediazide compounds. In particular, an onium salt is preferable from the viewpoint of thermal decomposability.

Examples of onium salts include diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, arsonium salts, and the like. Preferred examples of the onium salt used in the present invention include S.P. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Bal et al, Polymer, 21, 423 (1980), diazonium salts described in JP-A-5-158230, U.S. Pat. Nos. 4,069,055, 4,069,056, and Re27,992 Ammonium salts described in the specification, D.I. C. Necker et al, Macromolecules, 17, 2468 (1984), C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), U.S. Pat. Nos. 4,069,055 and 4,069,056. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent No. 104,143, JP-A-2-150848, JP-A-2-296514, J. Am. V. Crivello et al, Polymer J. et al. 17, 73 (1985), J. Am. V. Crivello et al. J. et al. Org. Chem. 43, 3055 (1978); R. Watt et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 22, 1789 (1984), J. Am. V. Crivello et al, Polymer Bull. 14, 279 (1985), J. Am. V. Crivello et al, Macromolecules, 14 (5), 1141 (1981), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. 17, 2877 (1979), European Patent Nos. 370,693, 3,902,114, 233,567, 297,443, and 297,442, U.S. Pat. 933,377, 4,760,013, 4,734,444, 2,833,827, German Patent 2,904,626, 3,604,580 No. 3,604,581, the sulfonium salts described in each specification, J. Org. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), a selenonium salt described in C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988).
In the photosensitive lithographic printing plate according to the invention, a diazonium salt is particularly preferable. Particularly suitable diazonium salts include those described in JP-A-5-158230.

  The counter ion of the onium salt includes tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5-sulfone Mention may be made of acids, anions from 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid and paratoluenesulfonic acid. Of these, alkyl aromatic sulfonates such as hexafluorophosphate, triisopropyl naphthalene sulfonate and 2,5-dimethylbenzene sulfonate are particularly preferable. The amount of the substance added is preferably 0.1 to 50% by mass, more preferably 0.1 to 30% by mass, and particularly preferably 0.3 to 30% by mass.

  Suitable quinonediazides include o-quinonediazide compounds. The o-quinonediazide compound used in the present invention is a compound having at least one o-quinonediazide group, which increases alkali solubility by thermal decomposition, and compounds having various structures can be used. That is, o-quinonediazide helps the solubility of the lower layer by both the effects of losing the ability to inhibit dissolution of the alkali-soluble resin by thermal decomposition and the change of o-quinonediazide itself into an alkali-soluble substance. Examples of the o-quinonediazide compound used in the present invention include J. Although compounds described in pages 339 to 352 of “Light-Sensitive Systems” by John Korser (John Wiley & Sons. Inc.) can be used, in particular, o reacted with various aromatic polyhydroxy compounds or aromatic amino compounds. -Sulfonic acid esters or sulfonic acid amides of quinonediazides are preferred. Further, benzoquinone (1,2) -diazidosulfonic acid chloride or naphthoquinone- (1,2) -diazide-5-sulfonic acid chloride and pyrogallol-acetone resin as described in JP-B-43-28403 Esters of benzoquinone- (1,2) -diazide sulfonic acid chloride or naphthoquinone- (1,2) described in US Pat. Nos. 3,046,120 and 3,188,210. -Esters of diazide-5-sulfonic acid chloride and phenol-formaldehyde resins are also preferably used.

Further, an ester of naphthoquinone- (1,2) -diazido-4-sulfonic acid chloride and phenol formaldehyde resin or cresol-formaldehyde resin, naphthoquinone- (1,2) -diazido-4-sulfonic acid chloride and pyrogallol-acetone resin The esters of are also preferably used. Other useful o-quinonediazide compounds are reported and known in numerous patents. For example, JP-A-47-5303, JP-A-48-63802, JP-A-48-63803, JP-A-48-96575, JP-A-49-38701, JP-A-48-13354, Japanese Patent Publication Nos. 41-11222, 45-9610, 49-174741, U.S. Pat. Nos. 2,797,213, 3,454,400, and 3,544,323. No. 3,573,917, No. 3,674,495, No. 3,785,825, British Patent No. 1,227,602, No. 1,251,345 No. 1,267,005, No. 1,329,888, No. 1,330,932, German Patent No. 854,890, etc. Can be mentioned. The addition amount of the o-quinonediazide compound used in the present invention is preferably 1 to 50% by mass, more preferably, based on the total solid content of the lower layer, from the viewpoints of image recording properties, image portion durability, and sensitivity. It is 5-30 mass%, Most preferably, it is the range of 10-30 mass%. These compounds can be used alone, but may be used as a mixture of several kinds.
From the viewpoint of degradability, the thermally decomposable substance is more preferably an onium salt.
By using this highly thermally decomposable onium salt, it is considered that the decomposition of the thermally decomposable substance in the exposed area is further promoted and the discrimination in the unexposed area of the exposed area is improved.

  In forming the photosensitive layer, in addition to the above components, various additives can be further added as necessary as long as the effects of the present invention are not impaired. Below, the example of an additive is given and demonstrated.

For example, in the molecule as described in JP-A-2000-187318, for the purpose of enhancing the discrimination between the image portion and the non-image portion (discrimination) and enhancing the resistance to scratches on the surface. It is preferable to use a polymer having a polymerization component of a (meth) acrylate monomer having 2 or 3 perfluoroalkyl groups having 3 to 20 carbon atoms.
The addition amount is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, based on the total solid content of the photosensitive layer.

  In the photosensitive lithographic printing plate according to the invention, a compound that lowers the coefficient of static friction of the surface may be added for the purpose of imparting scratch resistance. Specific examples include esters of long-chain alkyl carboxylic acids as used in US Pat. No. 6,117,913.

Moreover, you may contain the compound which has a low molecular-weight acidic group as needed. Examples of acidic groups include sulfonic acid, carboxylic acid, and phosphoric acid groups. Of these, compounds having a sulfonic acid group are preferred. Specific examples include aromatic sulfonic acids such as p-toluenesulfonic acid and naphthalenesulfonic acid, and aliphatic sulfonic acids.
The addition amount is preferably 0.05 to 5% by mass, more preferably 0.1 to 3% by mass in the material forming the layer from the viewpoint of solubility of the photosensitive layer in the developer.

  In the present invention, various dissolution inhibitors may be included for the purpose of adjusting the solubility. As the dissolution inhibitor, a disulfone compound or a sulfone compound as disclosed in JP-A-11-119418 is preferably used. As a specific example, it is preferable to use 4,4′-bishydroxyphenylsulfone.

Further, for the purpose of further improving sensitivity, cyclic acid anhydrides, phenols, and organic acids can be used in combination. Examples of cyclic acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-endooxy-Δ4-tetrahydrophthalic anhydride described in US Pat. No. 4,115,128, Tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be used. As phenols, bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,4,4′-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ′, 4 "-Trihydroxytriphenylmethane, 4,4 ', 3", 4 "-tetrahydroxy-3,5,3', 5'-tetramethyltriphenylmethane and the like.
Furthermore, examples of organic acids include sulfonic acids, sulfinic acids, alkyl sulfates, phosphonic acids, phosphate esters, and carboxylic acids described in JP-A-60-88942 and JP-A-2-96755. Specifically, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethyl sulfate, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, Examples include adipic acid, p-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 4-cyclohexene-1,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, ascorbic acid and the like. .

  In addition, in the photosensitive layer coating solution, a nonionic surfactant as described in JP-A-62-251740 or JP-A-3-208514, Amphoteric surfactants as described in JP-A-59-121044 and JP-A-4-13149, siloxane-based compounds as described in EP 950517, JP-A-11- A fluorine-containing monomer copolymer as described in Japanese Patent No. 288093 can be added.

  Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether and the like. Specific examples of amphoteric surfactants include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, and N-tetradecyl-N, N- Examples include betaine type (for example, trade name “Amorgen K” manufactured by Daiichi Kogyo Co., Ltd.).

  As the siloxane compound, a block copolymer of dimethylsiloxane and polyalkylene oxide is preferable. Specific examples include DBE-224, DBE-621, DBE-712, DBP-732, DBP-534, manufactured by Chisso Corporation. Polyalkylene oxide-modified silicones such as Tego Glide 100 manufactured by Tego, Germany can be mentioned.

Furthermore, a printing-out agent for obtaining a visible image immediately after heating by exposure and a dye or pigment as an image coloring agent can be added to the photosensitive layer.
Typical examples of the printing-out agent include a combination of a compound that releases an acid by heating by exposure (photoacid releasing agent) and an organic dye that can form a salt. Specifically, combinations of o-naphthoquinonediazide-4-sulfonic acid halides and salt-forming organic dyes described in JP-A-50-36209 and JP-A-53-8128, 36223, 54-74728, 60-3626, 61-143748, 61-151644, and 63-58440, and trihalomethyl compounds and salt-forming organic dyes Can be mentioned. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent temporal stability and give clear printout images.

  As the image colorant, other dyes can be used in addition to the above-mentioned salt-forming organic dyes. Examples of suitable dyes including salt-forming organic dyes include oil-soluble dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (oriental chemical industry) Manufactured by Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), and the like. The dyes described in JP-A-62-293247 are particularly preferred.

  Furthermore, a plasticizer is added to the photosensitive layer in the present invention, if necessary, in order to impart flexibility of the coating film. For example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid These oligomers and polymers are used.

[Formation of photosensitive layer]
The photosensitive layer in the present invention can be formed by dissolving the necessary components in a solvent and coating on a support. Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, and toluene. It is not limited. These solvents are used alone or in combination.
The density | concentration of the photosensitive layer coating liquid using the said solvent becomes like this. Preferably it is 1-50 mass%.

The coating amount of the photosensitive layer (solid content) may be varied according to the intended purpose, is preferably 0.5 to 3.0 g / m ^2, and decreases the film property is less than 0.5 g / m ^2, If it exceeds 3.0 g / m ² , the sensitivity tends to decrease.

Various methods can be used as a method for coating the photosensitive layer on the support. For example, bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, roll coating. Etc. can be mentioned.
In the photosensitive layer of the present invention, a surfactant for improving the coating property, for example, a fluorine-based surfactant described in JP-A-62-170950 can be added. A preferable addition amount is 0.01 to 1% by mass, more preferably 0.05 to 0.5% by mass in the total solid content of the layer to be added.

In the infrared-sensitive lithographic printing plate according to the present invention, the photosensitive layer formed as described above may be a single layer, but may have a multilayer structure composed of an upper layer and a lower layer.
In the case of a multilayer structure, the layer (lower layer) close to the support may be a layer that does not contain a photothermal conversion substance.
In the case of a multi-layer structure, the lower layer does not contain a copolymer having the monomer component represented by the general formula (a) or is used in a smaller amount than the upper layer, from the viewpoint of development latitude and scratch resistance. To preferred.

Upper and lower coating weight in the case of a multilayer structure (solid content) may be varied depending on the use, the upper layer is 0.05 to 1.0 g / m ^2, the lower layer is 0.3 to 3.0 g / m ² It is preferable that If the upper layer is less than 0.05 g / m ^2, the image forming property is lowered, sensitivity exceeds 1.0 g / m ² comes out may be reduced. The total coating amount of the two layers of is preferably 0.5 to 3.0 g / m ^2, and decreases the film property is less than ^{0.5g / m 2, 3.0g / m} 2 If it exceeds, the sensitivity tends to decrease.

[Support]
Examples of the support in the present invention include a dimensionally stable plate having necessary strength and durability. For example, paper on which paper, plastic (for example, polyethylene, polypropylene, polystyrene, etc.) is laminated. , Metal plates (eg, aluminum, zinc, copper, etc.), plastic films (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, Polycarbonate, polyvinyl acetal, and the like), paper laminated with a metal as described above, or vapor-deposited paper, or a plastic film.

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

  Prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution for removing rolling oil on the surface is performed as desired. The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, and a method of selectively dissolving a surface chemically. This is done by the method of As the mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used. The roughened aluminum plate is subjected to alkali etching treatment and neutralization treatment as necessary, and then subjected to anodization treatment if desired in order to enhance the water retention and wear resistance of the surface. As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.

The treatment conditions for anodization vary depending on the electrolyte used, and thus cannot be specified in general. In general, however, the electrolyte concentration is 1 to 80% by mass solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / dm ^2. A voltage of 1 to 100 V and an electrolysis time of 10 seconds to 5 minutes are suitable. When the amount of the anodized film is less than 1.0 g / m ² , the printing durability is insufficient, or the non-image part of the lithographic printing plate is easily damaged, and the ink adheres to the damaged part during printing. So-called “scratch dirt” is likely to occur. After the anodizing treatment, the aluminum surface is subjected to a hydrophilic treatment if necessary. Examples of the hydrophilic treatment applied to the support of the original plate according to the present invention include U.S. Pat. Nos. 2,714,066, 3,181,461, 3,280,734, and 3,902. There is an alkali metal silicate (for example, sodium silicate aqueous solution) method as disclosed in each specification of No. 734. In this method, the support is immersed in an aqueous sodium silicate solution or electrolytically treated. In addition, potassium fluoride zirconate disclosed in Japanese Patent Publication No. 36-22063 and U.S. Pat. Nos. 3,276,868, 4,153,461, and 4,689,272 For example, a method of treating with polyvinylphosphonic acid as disclosed in the literature is used.

In the lithographic printing plate precursor according to the invention, a photosensitive layer is provided on a support. If necessary, an undercoat layer can be provided between the support and the photosensitive layer.
Various organic compounds are used as the primer layer component. For example, phosphonic acids having an amino group such as carboxymethylcellulose, dextrin, gum arabic, 2-aminoethylphosphonic acid, and phenylphosphonic acid which may have a substituent Organic phosphonic acids such as naphthyl phosphonic acid, alkyl phosphonic acid, glycero phosphonic acid, methylene diphosphonic acid and ethylene diphosphonic acid, phenyl phosphoric acid, naphthyl phosphoric acid, alkyl phosphoric acid and glycerophosphoric acid which may have a substituent Organic phosphoric acid, optionally substituted phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid, glycerophosphinic acid and other organic phosphinic acids, glycine and β-alanine amino acids, and triethanolamine hydrochloric acid Has a hydroxy group such as salt -Alanine, and hydrochlorides of amines that may be used in combination of two or more.
Furthermore, an undercoat layer containing at least one compound selected from the group of organic polymer compounds having a structural unit represented by the following formula is also preferred.

Here, R ¹¹ represents a hydrogen atom, a halogen atom or an alkyl group, and R ¹² and R ¹³ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, ^{-OR 14, -COOR 15, -CONHR 16} , or represents -COR ¹⁷ or -CN, or may be R ¹² and R ¹³ combine to form a ring, R ¹⁴ to R ¹⁷ are each independently Represents an alkyl group or an aryl group, X represents a hydrogen atom, a metal atom, or NR ¹⁸ R ¹⁹ R ²⁰ R ²¹ , and R ^{18 to} R ²¹ each independently represent a hydrogen atom, an alkyl group, a substituted alkyl group, or an aryl group. Alternatively, it represents a substituted aryl group, or R ¹⁸ and R ¹⁹ may be bonded to form a ring, and m represents an integer of 1 to 3.

This undercoat layer can be provided by the following method. That is, a method in which water or an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof is dissolved and applied on an aluminum plate and dried, and water, methanol, ethanol, methyl ethyl ketone, etc. In this method, an aluminum plate is immersed in a solution obtained by dissolving the above organic compound in the above organic solvent or a mixed solvent thereof to adsorb the above compound, and then washed and dried with water or the like to provide an undercoat layer. In the former method, a solution of the organic compound having a concentration of 0.005 to 10% by mass can be applied by various methods. In the latter method, the concentration of the solution is 0.01 to 20% by mass, preferably 0.05 to 5% by mass, the immersion temperature is 20 to 90 ° C., preferably 25 to 50 ° C., and the immersion time. Is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute. The solution used for this can be adjusted to a pH range of 1 to 12 with basic substances such as ammonia, triethylamine, potassium hydroxide, and acidic substances such as hydrochloric acid and phosphoric acid. A yellow dye can also be added to improve the tone reproducibility of the photosensitive lithographic printing plate.
The coating amount of the undercoat layer is suitably ² to 200 mg / m ² , preferably 5 to 100 mg / m ² . If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. Moreover, even if it is larger than 200 mg / m ^2, it is the same.

[Plate making / printing]
The lithographic printing plate precursors produced as described above are shipped, transported and stored in the form of products stacked and packaged with interleaving paper inserted between the lithographic printing plate precursors. This is a general aspect. As a typical mode for plate making and printing, an autoloader secures a pair of overlapped paper and original plate to the autoloader, conveys them, and attaches and fixes them at the position where plate making is performed. Although it is a mode in which the paper is removed, the present invention is not limited to this.
The original plate from which the interleaving paper has been removed is subjected to image exposure and development processing.
As an actinic ray light source used for image exposure, a light source having an emission wavelength in the near infrared to infrared region is preferable, and it is not necessarily a scanning method, that is, a surface exposure method may be used. Scanning exposure using a laser or semiconductor laser is preferred. The emission wavelength is preferably 760 to 1080 nm.

  The developer that can be applied to the lithographic printing plate precursor according to the invention is a developer having a pH in the range of 9.0 to 14.0, preferably in the range of 12.0 to 13.5. A conventionally known alkaline aqueous solution can be used as the developer (hereinafter referred to as developer including the replenisher). For example, sodium silicate, potassium, tribasic sodium phosphate, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, Examples include inorganic alkali salts such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium. Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are listed. These alkaline aqueous solutions may be used individually by 1 type, and may use 2 or more types together.

  Among the above alkaline aqueous solutions, one of the developing solutions that exert the effect according to the present invention is a so-called one containing an alkali silicate as a base or containing an alkali silicate by mixing a silicon compound with a base. Another more preferable developer called an “silicate developer” having an pH of 12 or higher does not contain an alkali silicate, and contains a non-reducing sugar (an organic compound having a buffering action) and a base. Silicate developer ".

In the former, the aqueous solution of alkali metal silicate is represented by the ratio of silicon oxide SiO ₂ which is a component of silicate to alkali metal oxide M ₂ O (generally expressed as a molar ratio of [SiO ₂ ] / [M ₂ O]. ) And the density, the developing property can be adjusted. For example, as disclosed in JP-A-54-62004, the molar ratio of SiO ₂ / Na ₂ O is 1.0 to 1.5 (that is, [SiO ₂ ] / [Na ₂ O] is 1.0 to 1.5), and an aqueous solution of sodium silicate having a SiO ₂ content of 1 to 4 mass% is disclosed in JP-B-57-7427. As described, [SiO ₂ ] / [M] is 0.5 to 0.75 (ie, [SiO ₂ ] / [M ₂ O] is 1.0 to 1.5), and SiO ₂ The developer is based on gram atoms of all alkali metals present in the developer. A manner containing potassium at least 20 wt%, aqueous solution of alkali metal silicate is preferably used.

  In addition, a so-called “non-silicate developer” which does not contain an alkali silicate and contains a non-reducing sugar and a base is more preferable for application to the development of a lithographic printing plate precursor in the present invention. When this developer is used to develop the lithographic printing plate precursor, the surface of the photosensitive layer is not deteriorated and the inking property of the photosensitive layer can be maintained in a good state. In addition, the lithographic printing plate precursor generally has a narrow development latitude and a large change in the image line width due to the developer pH, but the non-silicate developer contains a non-reducing sugar having a buffering property that suppresses fluctuations in pH. Therefore, it is more advantageous than the case where a developing processing solution containing silicate is used. Furthermore, since non-reducing sugars are less likely to contaminate conductivity sensors, pH sensors and the like for controlling liquid activity compared to silicates, non-silicate developers are advantageous in this respect as well. In addition, the effect of improving discrimination between the image portion and the non-image portion (discrimination) is remarkable. This is presumed to be because the contact (penetration) with the developer, which is important for maintaining the distinguishability and film physical properties in the present invention, becomes mild, and the difference between the exposed and unexposed areas is likely to occur.

  The non-reducing sugar is a saccharide that does not have a free aldehyde group or a ketone group and does not exhibit reducibility, and is a trehalose-type oligosaccharide in which reducing groups are bonded to each other, or a glycoside in which a reducing group and a non-saccharide are bonded to each other. And sugar alcohols reduced by hydrogenation of saccharides and sugars, both of which can be suitably used in the present invention. In the present invention, non-reducing sugars described in JP-A-8-305039 can be preferably used.

  Examples of the trehalose type oligosaccharides include saccharose and trehalose. Examples of the glycoside include alkyl glycosides, phenol glycosides, and mustard oil glycosides. Examples of the sugar alcohol include D, L-arabit, rebit, xylit, D, L-sorbit, D, L-mannit, D, L-exit, D, L-talit, zulsiit, allozulcit and the like. . Further, maltitol hydrogenated to disaccharide maltose, reduced form obtained by hydrogenation of oligosaccharide (reduced water candy), and the like are preferable. Among these non-reducing sugars, trehalose-type oligosaccharides and sugar alcohols are preferable, and among them, D-sorbitol, saccharose, reduced syrup, etc. are preferable in that they have a buffering action in an appropriate pH region and are inexpensive.

  These non-reducing sugars may be used alone or in combination of two or more. The content of the non-reducing sugar in the non-silicate developer is preferably 0.1 to 30% by mass, and more preferably 1 to 20% by mass. If the content is less than 0.1% by mass, a sufficient buffering effect tends to be not obtained, and if it exceeds 30% by mass, it is difficult to achieve high concentration and the cost tends to increase.

  Moreover, as a base used in combination with the said non-reducing sugar, a conventionally well-known alkali agent, for example, an inorganic alkali agent, an organic alkali agent, etc. are mentioned. Examples of the inorganic alkaline agent include sodium hydroxide, potassium hydroxide, lithium hydroxide, trisodium phosphate, tripotassium phosphate, triammonium phosphate, disodium phosphate, dipotassium phosphate, diammonium phosphate, Examples thereof include sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate, sodium borate, potassium borate, and ammonium borate.

  Examples of the organic alkali agent include monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanol. Examples include amine, diisopropanolamine, ethyleneimine, ethylenediamine, and pyridine.

The said base may be used individually by 1 type, and may use 2 or more types together. Among these bases, sodium hydroxide and potassium hydroxide are preferable.
In the present invention, as the non-silicate developer, a non-reducing sugar alkali metal salt as a main component can be used instead of the non-reducing sugar and the base.

  In addition, an alkaline buffer composed of a weak acid other than the non-reducing sugar and a strong base can be used in combination with the non-silicate developer. The weak acid preferably has a dissociation constant (pKa) of 10.0 to 13.2, and can be selected from, for example, those described in Ionization Constants of Organic Acids Solution issued by Pergmon Press.

  Specifically, alcohols such as 2,2,3,3-tetrafluoropropanol-1, trifluoroethanol and trichloroethanol, pyridine-2-aldehyde (, aldehydes such as pyridine-4-aldehyde (and the like) , Salicylic acid, 3-hydroxy-2-naphthoic acid, catechol, gallic acid, sulfosalicylic acid, 3,4-dihydroxysulfonic acid, 3,4-dihydroxybenzoic acid, hydroquinone (11.56), pyrogallol, o-, m Compounds having a phenolic hydroxyl group such as-, p-cresol, resorsonol, oximes such as acetoxime, 2-hydroxybenzaldehyde oxime, dimethylglyoxime, ethanediamide dioxime, acetophenone oxime, adenosine, inosine, guanine, cytosine, hypoxanthine , Ki Nucleic acid-related substances such as Nchin, other, diethylaminomethyl acid, benzimidazole, and the like barbituric acid is preferably exemplified.

  In the developer and replenisher, various surfactants and organic solvents are added as necessary for the purpose of promoting and suppressing developability, dispersing development residue, or improving ink affinity of the printing plate image area. it can. As the surfactant, anionic, cationic, nonionic and amphoteric surfactants are preferable. Further, the developer and replenisher may contain a reducing agent such as sodium salt and potassium salt of inorganic acids such as hydroquinone, resorcin, sulfurous acid, and bisulfite, as well as organic carboxylic acid, antifoaming agent, hard water, if necessary. Softeners and the like can be added.

  The image forming material developed using the developer and the replenisher is post-processed with a desensitizing solution containing washing water, a rinsing solution containing a surfactant or the like, gum arabic or a starch derivative. As the post-treatment when the image forming material is used as a printing plate, these treatments can be used in various combinations.

In the plate making / printing industry, automatic developing apparatuses are widely used for stable development of exposed photosensitive lithographic printing plates. This automatic developing device generally comprises a developing unit and a post-processing unit, and comprises a printing plate conveying device, each processing liquid tank and a spray device. A developing solution is sprayed from a spray nozzle. In addition, recently, a method is also known in which a printing plate is dipped and conveyed by a submerged guide roll or the like in a processing liquid tank filled with the processing liquid. In such automatic processing, each processing solution can be processed while being supplemented with a replenisher according to the processing amount, operating time, and the like.
The plate making method of the lithographic printing plate of the present invention is applied to the processing by the automatic developing apparatus as described above.

  In the plate making operation to which the plate making method of the lithographic printing plate of the present invention is applied, an unnecessary image portion is present in the lithographic printing plate obtained by image exposure, development, washing and / or rinsing and / or gumming. In some cases, the unnecessary image portion is erased. Such erasing is preferably performed by applying an erasing solution to an unnecessary image portion as described in Japanese Patent Publication No. 2-13293, leaving it for a predetermined time, and then washing with water. A method of developing after irradiating an unnecessary image portion with an actinic ray guided by an optical fiber as described in JP-A-59-174842 can also be used.

The lithographic printing plate obtained as described above can be subjected to a printing process after applying a desensitized gum if desired. However, if it is desired to obtain a lithographic printing plate with higher printing durability, Processing is performed. In the case of burning a lithographic printing plate, before burning, an adjustment as described in JP-B-61-2518, JP-A-55-28062, JP-A-62-31859, JP-A-61-159655 is used. It is preferable to treat with a surface liquid.
As its method, with a sponge or absorbent cotton soaked with the surface-adjusting liquid, it is applied onto a lithographic printing plate, or a method in which the printing plate is immersed and applied in a vat filled with the surface-adjusting liquid, Application by an automatic coater is applied. Further, it is more preferable to make the coating amount uniform with a squeegee or a squeegee roller after coating.

In general, the amount of surface-adjusting solution applied is suitably 0.03 to 0.8 g / m ² (dry mass). The lithographic printing plate coated with the surface-adjusting liquid is dried if necessary, and then heated to a high temperature with a burning processor (for example, burning processor “BP-1300” sold by Fuji Photo Film Co., Ltd.). Is done. In this case, the heating temperature and time are in the range of 180 to 300 ° C. and preferably in the range of 1 to 20 minutes, although depending on the type of components forming the image.

  The burned lithographic printing plate can be subjected to conventional treatments such as water washing and gumming as needed, but a surface-conditioning solution containing a water-soluble polymer compound or the like was used. In some cases, so-called desensitizing treatment such as gumming can be omitted. The planographic printing plate obtained by such processing is applied to an offset printing machine or the like and used for printing a large number of sheets.

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

[Example 1]
(Production of support)
(Preparation of support 1)
0.24 mm thick aluminum plate (Si: 0.06 mass%, Fe: 0.30 mass%, Cu: 0.014 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn : 0.001% by mass, Ti: 0.03% by mass, the balance being Al and an inevitable impurity aluminum alloy), the following surface treatment was continuously performed.
While a suspension of a polishing agent (silica sand) having a specific gravity of 1.12 and water was supplied as a polishing slurry liquid to the surface of the aluminum plate, mechanical surface roughening was performed with a rotating roller-shaped nylon brush. Thereafter, etching treatment was performed by spraying at a caustic soda concentration of 2.6% by mass, an aluminum ion concentration of 6.5% by mass, and a temperature of 70 ° C., 6 g / m ^{2 of the} aluminum plate was dissolved, and water washing by spraying was performed. Further, a desmut treatment was performed by spraying with a 1% by mass aqueous solution of nitric acid having a nitric acid concentration of 30 ° C. (containing 0.5% by mass of aluminum ions) and washed with water by spraying. Thereafter, an electrochemical roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a nitric acid 10 g / l aqueous solution (containing 5 g / l of aluminum ions and 0.007% by mass of ammonium ions) at a temperature of 80 ° C. After washing with water, the aluminum plate was etched by spraying at 32 ° C. with a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass%, the aluminum plate was dissolved at 0.20 g / m ² , and washed with water. Thereafter, a desmut treatment by spraying was performed with a 25% by weight aqueous solution of sulfuric acid having a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), and washing with water by spraying was performed.
Anodization was performed using an anodizing apparatus of a two-stage power supply electrolytic treatment method. Sulfuric acid was used as the electrolytic solution supplied to the electrolysis unit. Then, water washing by spraying was performed. The final oxide film amount was 2.7 g / m ² .
The anodized aluminum plate was immersed in a 1% by mass aqueous solution of sodium silicate No. 3 having a temperature of 30 ° C. for 10 seconds to perform alkali metal silicate treatment (silicate treatment). Then, water washing by spraying was performed.
On the aluminum plate after the silicate treatment obtained as described above, an undercoat liquid having the following composition was applied and dried at 80 ° C. for 15 seconds to form an undercoat film having a dry coating amount of 15 mg / m ^2. A support 1 was prepared.

<Undercoat liquid composition>
・ The following compound 0.3g
・ Methanol 100g
・ Water 1g

(Preparation of support 2)
The same aluminum plate as used in the production of the support 1 was subjected to the following surface treatment continuously.
An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a nitric acid 10 g / l aqueous solution (containing 5 g / l of aluminum ions and 0.007% by mass of ammonium ions) at a temperature of 80 ° C. After washing with water, the aluminum plate was etched by spraying at 32 ° C. with a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass%, the aluminum plate was dissolved at 0.20 g / m ² , and washed with water. Thereafter, a desmut treatment by spraying was performed with a 25% by weight aqueous solution of sulfuric acid having a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), and washing with water by spraying was performed.
In the same manner as in the production of the support 1, an anodizing treatment, a silicate treatment, and an undercoat liquid application were performed on the aluminum plate subjected to the electrochemical surface roughening treatment as described above to produce a support 2.

(Preparation of support 3)
An aluminum plate (material: JIS A 1050) having a thickness of 0.3 mm is etched for 10 seconds at a caustic soda concentration of 30 g / l, an aluminum ion concentration of 10 g / l, a liquid temperature of 60 ° C., washed with running water, and washed with 10 g / l nitric acid. After neutralizing and washing with water. Using an alternating current of a sine wave under the condition of applied voltage Va = 20 V, an electric current of 500 C / dm ² in an aqueous solution having a hydrogen chloride concentration of 15 g / l, an aluminum ion concentration of 10 g / l, and a liquid temperature of 30 ° C. The surface was subjected to an electrochemical surface roughening treatment in an amount and washed with water, followed by an etching treatment for 10 seconds at a caustic soda concentration of 30 g / l, an aluminum ion concentration of 10 g / l and a liquid temperature of 40 ° C., and then washed with running water. Next, it was desmutted in a sulfuric acid aqueous solution having a sulfuric acid concentration of 15% by mass and a liquid temperature of 30 ° C., and washed with water. Furthermore, in a 10% by mass sulfuric acid aqueous solution at a liquid temperature of 20 ° C., an anodizing treatment was performed under a condition of a current density of 6 A / dm ² by direct current so that the amount of the anodized film was 2.5 g / m ² , and washing with water. , Dried. Then, it processed for 10 second at 30 degreeC with 2.5 mass% sodium silicate aqueous solution, and produced the support body. The center line average roughness (Ra) of the support was measured using a needle having a diameter of 2 μm and found to be 0.48 μm.
On the silicate-treated aluminum plate obtained as described above, undercoat liquid application (dry coating amount 17 mg / m ² ) was performed in the same manner as in the production of the support 1, and the support 3 was produced.

(Preparation of support 4)
The following processes (a) to (l) were performed in this order to prepare a support 4.
(A) Mechanical roughening treatment Using a JIS-A-1050 aluminum plate having a thickness of 0.3 mm, a slurry of a specific gravity 1.12 abrasive (silica sand) and water as an abrasive slurry liquid is used as aluminum. While being supplied to the surface of the plate, mechanical roughening was performed with a rotating roller-like nylon brush. The average particle size of the abrasive was 8 μm, and the maximum particle size was 50 μm. The material of the nylon brush was 6 · 10 nylon, the hair length was 50 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 7 kW plus with respect to the load before the brush roller was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The rotation speed of the brush was 200 rpm.

(B) Alkali etching treatment The aluminum plate obtained above was sprayed with an aqueous NaOH solution at a temperature of 70 ° C. (concentration 26 mass%, aluminum ion concentration 6.5 mass%) to carry out an etching treatment, and the aluminum plate was 6 g / m. ² dissolved. Thereafter, washing with water was performed using well water.

(C) Desmutting treatment The desmutting treatment was performed by spraying with a 1% by mass aqueous solution of nitric acid at a temperature of 30 ° C. (containing 0.5% by mass of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut was the waste liquid from the step of electrochemical surface roughening using alternating current in nitric acid aqueous solution.

(D) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was nitric acid 10.5 g / l aqueous solution (aluminum ion 5 g / l), and the temperature was 50 ° C. The AC power supply waveform is electrochemically roughened using a carbon electrode as the counter electrode, using a trapezoidal rectangular wave alternating current with a time TP of 0.8 msec until the current value reaches a peak from zero, a DUTY ratio of 1: 1. went. Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type.
The current density was 30 A / dm ² at the peak current value, and the amount of electricity was 220 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode.
Thereafter, washing with water was performed using well water.

(E) Alkali etching treatment The aluminum plate was sprayed at a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass at 32 ° C. to dissolve the aluminum plate by 0.20 g / m ² , The smut component mainly composed of aluminum hydroxide generated when electrochemical surface roughening was used was removed, and the edge portion of the generated pit was melted to smooth the edge portion. Thereafter, washing with water was performed using well water.

(F) Desmut treatment Desmut treatment was performed by spraying with a 15% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 4.5% by weight of aluminum ions), and then washed with water using well water. The nitric acid aqueous solution used for the desmut was the waste liquid from the step of electrochemical surface roughening using alternating current in nitric acid aqueous solution.

(G) Electrochemical surface roughening treatment An electrochemical surface roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 7.5 g / l aqueous solution (containing 5 g / l of aluminum ions) at a temperature of 35 ° C. The AC power supply waveform was a rectangular wave, and an electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type.
The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 50 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode.
Thereafter, washing with water was performed using well water.

(H) Alkaline etching treatment An aluminum plate is etched by spraying at 32 ° C. with a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass, and the aluminum plate is dissolved at 0.10 g / m ² , so The smut component mainly composed of aluminum hydroxide generated during the electrochemical surface roughening treatment was removed, and the edge portion of the generated pit was melted to smooth the edge portion. Thereafter, washing with water was performed using well water.

(A) Desmut treatment Desmut treatment was performed by spraying with a 25% by weight aqueous solution of sulfuric acid at a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), and then washed with water using well water.

(J) Anodizing treatment As the electrolytic solution, sulfuric acid was used. All electrolytes had a sulfuric acid concentration of 170 g / l (containing 0.5 mass% of aluminum ions) and a temperature of 43 ° C. Thereafter, washing with water was performed using well water.
Both current densities were about 30 A / dm ² . The final oxide film amount was 2.7 g / m ² .

(K) Silicate treatment The silicate treatment was performed in the same manner as in the production of the support 1. The amount of silicate attached was 3.5 mg / m ² .

(L) Formation of undercoat The undercoat liquid was applied in the same manner as in the production of the support 1. The coating amount after drying was 15 mg / m ² .

[Preparation of photosensitive lithographic printing plate precursors 1 to 4]
After applying the photosensitive layer lower layer coating solution 1 having the following composition to the supports 1 to 4 obtained as described above, the Wind Control is set to 7 on the PERFECT OVEN PH200 manufactured by Tabai Co., at 130 ° C. Drying was performed for 50 seconds, and a lower layer having a dry coating amount of 0.85 g / m 2 was provided. Next, the photosensitive layer upper layer coating solution 1 was coated thereon so that the dry coating amount was 0.25 g / m ² . Drying conditions were 140 ° C. and 1 minute.
As described above, photosensitive lithographic printing plate precursors (photosensitive lithographic printing plates 1 to 4) used in Example 1 were obtained.

(Coating solution 1 for photosensitive layer lower layer)
N- (4-aminosulfonylphenyl) methacrylamide /
Acrylonitrile / methyl methacrylate 2.133 g
(36/34/30% by mass, weight average molecular weight 50000, acid value 2.65)
・ Cyanine dye A (the following structure) 0.109 g
・ 4,4'-bishydroxyphenylsulfone 0.126g
・ Cis-Δ4-tetrahydrophthalic anhydride 0.190 g
・ 0.008 g of p-toluenesulfonic acid
・ 3-methoxy-4-diazodiphenylamine hexafluorophosphate 0.030 g
・ The counter ion of ethyl violet is 6-hydroxy-2-
0.100 g changed to naphthalenesulfonate
・ Megafuck F176 0.035g
(Dainippon Ink & Chemicals, Inc., coated surface modified fluorine-based surfactant)
・ Methyl ethyl ketone 25.38g
・ 13.0 g of 1-methoxy-2-propanol
・ Γ-butyrolactone 13.2 g

(Photosensitive layer upper coating solution 1)
・ M, p-cresol novolak 0.4000g
(M / p ratio = 6/4, weight average molecular weight 4500,
Contains 0.8% by mass of unreacted cresol)
・ Specific copolymer (the following structure) 0.1000g
・ Cyanine dye A (the above structure) 0.0192 g
・ Ammonium compound (the following structure) 0.0115 g
・ Megafuck F176 (20%) 0.022g
(Dai Nippon Ink Chemical Co., Ltd., surface improved surfactant)
・ 1-methoxy-2-propanol 13.07 g
・ Methyl ethyl ketone 6.79g

[Plate making]
(exposure)
For the photosensitive lithographic printing plate precursors 1 to 4 (650 mm × 550 mm × 0.3 mm thickness) obtained above, Fuji Photo Film Co., Ltd. plate setter Luxplate Plater 9000 CTP (output 216 mW, rotation speed 1000 rpm, resolution) The exposure was performed using 2438 dpi).

(developing)
The following development was performed on the photosensitive lithographic printing plate precursors 1 to 4 after exposure.
For the development, an automatic developing apparatus 10 having an immersion type developing tank shown in FIG. 1 was used. The squeezing roller 40a shown in FIG. 1 is a rotating rubbing member. As the rotating rubbing member, a Molton roller in which a nonwoven fabric having a thickness of 4 mm was wound around a rubber roller was used. Further, the rotational speed of the rotating rubbing member was controlled to be 5% slower than the transport speed of the planographic printing plate precursor. The contact width was adjusted to 2.5 mm and installed. The squeezing roller 40b that makes a pair with the squeezing roller 40a was a rubber roller.
In the developing tank (developing tank) 14 of this automatic developing apparatus 10, 27 liters of a developing solution (alkali developing solution A (pH about 13)) having the following composition was charged and kept at 30 ° C. A water washing treatment tank (water washing tank) 28 was charged with 8 liters of tap water. The finisher treatment tank (gum solution tank) 30 was charged with 8 liters of finishing gum solution diluted with FG-1 (Fuji Photo Film Co., Ltd.): Water = 1: 1.

<Composition of alkali developing solution A>
・ D sorbit 2.5% by mass
-Sodium hydroxide 0.85 mass%
・ Diethylenetriaminepenta (methylenephosphonic acid) 5Na salt 0.05% by mass
・ Water 96.6% by mass

  The development processing is performed while replenishing photosensitive lithographic printing plate precursors 1 to 4 after exposure with the first development replenishment control impedance value of the automatic developing device 10 being 45.0 mS / cm and replenishing the following development replenisher B. went.

<Composition of development replenisher B>
・ D sorbit 5.6% by mass
・ Sodium hydroxide 2.5% by mass
・ Diethylenetriaminepenta (methylenephosphonic acid) 5Na salt 0.2% by mass
・ Water 91.7 mass%

The exposure / development process was continued for 90 days.
The photosensitive lithographic printing plate precursor 1 (650 mm × 550 mm, 0.3 mm thickness) was developed by 100 plates per day. For photosensitive lithographic printing plate precursors 2 to 4 (650 mm × 550 mm, 0.3 mm thickness), 50 plates were developed per day.

  As a result, in the lithographic printing plate making method in Example 1 (lithographic printing plate making method of the present invention), any of the photosensitive lithographic printing plate precursors 1 to 4 could be stably developed for 90 days. Further, when the obtained lithographic printing plate was printed, a good printed matter was obtained in which the image was free of scratches, the image density was sufficient, and the non-image area was free of coloring and stains.

[Examples 2 to 13]
For the photosensitive lithographic printing plate precursors 1 to 4 obtained in the same manner as in Example 1, the rubbing member in the automatic developing device 10 with respect to the location of the rubbing member, the type of rubbing member, and the conveying speed of the lithographic printing plate precursor The plate making process was performed in the same manner as in Example 1 except that the difference in rotation speed and the contact width were changed as shown in Table 1 below.
In Table 1, “40a” at the position where the rubbing member is arranged indicates that the squeezing roller 40a is a rotating rubbing member. Similarly, “54a” indicates that the conveying roller 54a is a rubbing member that rotates, and “56a” indicates that the conveying roller 56a is a rotating rubbing member.

  As a result, in the lithographic printing plate making method in Examples 2 to 13 (lithographic printing plate making method of the present invention), any photosensitive lithographic printing plate precursor 1 to 4 could be stably developed for 90 days. . Further, when the obtained lithographic printing plate was printed, a good printed matter was obtained in which there was no scratch on the image, the image density was sufficient, and the non-image area was free of coloring and stains.

[Comparative Example 1]
For the photosensitive lithographic printing plate precursors 1 to 4 obtained in the same manner as in Example 1, the squeezing roller 40a of the automatic developing device 10 is composed of a mere silicone rubber roller and is not used as a rotating rubbing member. The plate making process was performed in the same manner as in Example 1.
As a result, in the lithographic printing plate making method in Comparative Example 1, a residual film having a diameter of 0.5 mm was generated on the fifth day.
Thus, if the lithographic printing plate making method of the present invention is not used, the automatic developing apparatus can only operate for 5 days under the condition that a lithographic printing plate in a preferable state can be obtained. This shows that the lithographic printing plate making method of the present invention is effective.

[Example 14]
The plate making process shown below was performed on the photosensitive lithographic printing plate precursors 1 to 4 obtained in the same manner as in Example 1.

〔exposure〕
For the obtained photosensitive lithographic printing plate precursors 1 to 4 (650 mm × 550 mm × 0.24 mm thickness), a Creo plate setter Trendsetter 3244F (output: 9.0 W, rotation speed: 150 rpm, resolution 2400 dpi) was used. Were exposed.

〔developing〕
The following development was performed on the lithographic printing plate precursors 1 to 4 after exposure.
Using an automatic developing apparatus 10 having an immersion type developing tank similar to that used in Example 1, a developing solution (alkaline developing solution C (pH of about 13)) having the following composition is used in a developing processing tank (developing tank) 14. 27 liters was charged and kept at 30 ° C.
A water washing treatment tank (water washing tank) 28 was charged with 8 liters of a water washing solution (a solution obtained by diluting the following developing solution to 1/10 with tap water) to which the following developing solution was added.
The finisher treatment tank (gum solution tank) 30 was charged with 8 liters of finishing gum solution diluted with FG-1 (Fuji Photo Film Co., Ltd.): Water = 1: 1.

<Composition of alkali developing solution C>
· Si0 ₂ · K ₂ O 4.0 mass%
(K ₂ 0 / Si 0 ₂ = 1.1 (molar ratio))
・ Citric acid 0.5% by mass
・ Polyethylene glycol 0.5% by mass
(Weight average molecular weight: 1000)
・ Water 95.0 mass%

  The development processing is carried out by applying development replenisher D having the following composition to LP-940H for each of the photosensitive lithographic printing plate precursors 1 to 4 (650 mm × 550 mm × 0.24 mm thickness) after exposure. It was performed while replenishing 35 cc at a time.

<Composition of development replenisher D>
・ SiO ₂・ K ₂ O 5.0% by mass
(K ₂ O / SiO ₂ = 1.1 (molar ratio))
・ Citric acid 0.6% by mass
・ Polyethylene glycol 0.6% by mass
(Weight average molecular weight: 1000)
・ Water 93.8% by mass

The exposure / development processing was carried out continuously for 200 days for 90 days per day.
As a result, in the lithographic printing plate making method in Example 14 (lithographic printing plate making method of the present invention), any of the photosensitive lithographic printing plate precursors 1 to 4 could be stably developed for 90 days. Moreover, when the obtained lithographic printing plate was printed, there was no flaw in the image, the image density was sufficient, and a good printed matter without coloring or smearing in the non-image area was obtained.

[Comparative Example 2]
In Example 14, the plate making process was performed in the same manner as in Example 14 except that the squeezing roller 40a of the automatic developing device 10 was composed of a simple silicone rubber roller and was not used as a rotating rubbing member.
As a result, in the lithographic printing plate making method in Comparative Example 2, a residual film having a diameter of 0.5 mm was generated on the seventh day.
Thus, if the lithographic printing plate making method of the present invention is not used, the automatic developing apparatus can only operate for 7 days under the condition that a lithographic printing plate in a preferable state can be obtained. This shows that the lithographic printing plate making method of the present invention is effective.

1 is a schematic configuration diagram showing a typical automatic developing apparatus applicable to a plate making method of a lithographic printing plate according to the present invention.

Explanation of symbols

10 Automatic development device 12 Photosensitive planographic printing plate (plate material)
16 Drying unit 18 Developing unit 24 Washing unit 26 Finisher unit 32 Plate material transport roller 36 Rotating rubbing member 38 in contact with the surface of the photosensitive layer Rotating rubbing member 40 in contact with the back surface of the photosensitive layer (40a and 40b) A pair of squeezing rollers (Rotating rubbing member)
54 (54a and 54b) A pair of conveying rollers (rotating rubbing members)
56 (56a and 56b) A pair of conveying rollers (rotating rubbing members)

Claims (1)

On the support, a lithographic printing plate precursor having a positive photosensitive layer containing an aqueous alkali solution-soluble resin and a photothermal conversion substance, after exposure, at least a developing part, a water washing part, a finisher part, A plate-making method of a lithographic printing plate for plate-making using an automatic developing device equipped with a conveying member for a lithographic printing plate precursor,
In the automatic developing apparatus, a rotating rubbing member is disposed at least at one of the outlet of the developing unit, the inlet of the washing unit, and the outlet of the washing unit so as to contact the photosensitive layer of the lithographic printing plate precursor. Set up
A lithographic printing plate making method, wherein the rotating speed of the rubbing member is different from the conveying speed of the lithographic printing plate precursor.

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