JP2001343758A - Development processing method for photosensitive planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a development processing method which is capable of maintaining the development activity of a developer, regardless of the amount of the photosensitive materials to be subjected to development processing within a prescribed time. SOLUTION: This development processing method for photosensitive planographic printing plates is characterized in that the activity of the developer is maintained constant, by replenishing the developer by using a development replenishing liquid, which compensates for the degradation in the activity of the developer by the processing method of the photosensitive planographic printing plates and a development replenishing liquid which compensates for the degradation in the activity of the developer with the lapse of time, which are different in alkalinity concentration. The development processing method for the photosensitive planographic printing plates is characterized, in that the developer is replenished with the development replenishing liquid which is the same as the concentrated stock solution of the replenishing liquid for replenishing degradation in the activity by the processing and the replenishing liquid for replenishing the degradation in the activity with the lapse of time but which varies in dilution ratio in this development processing described.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for developing a light-sensitive material, and more particularly to a method for developing a light-sensitive material capable of maintaining a constant developing activity of a developing solution when developing the light-sensitive material.

[0002]

2. Description of the Related Art In the case of a positive photosensitive lithographic printing plate (PS plate), which is used in a particularly large amount among lithographic printing plates,
The exposure and development processes of the photosensitive lithographic printing plate are schematically as follows. The positive PS plate typically has a photosensitive layer made of a composition containing an o-quinonediazide compound provided on an aluminum plate, but the o-quinonediazide compound is basically irradiated with actinic rays. Decomposes into a compound having a carboxyl group. Therefore, in the case of a positive PS plate, when the photosensitive layer surface is exposed to actinic rays through a transparent positive image, the o-quinonediazide compound present in the exposed area of the photosensitive layer changes to carboxylic acid, which is then used as a developing solution in an alkaline aqueous solution. When the development is carried out, a positive image is formed on the PS plate since it is dissolved and removed in an alkaline aqueous solution. At this time, the carboxylic acid dissolved in the alkaline developer and other acidic components contained in the photosensitive layer of the PS plate, and further, carbon dioxide gas dissolved / invaded from the air is contained in the developer. Reacts with alkaline components,
You consume this. That is, the alkaline component in the developing solution is reduced by the development of the PS plate. In addition, fatigue caused by evaporation of water and carbon dioxide gas in the developer,
It is a factor that changes the developing activity of the developer.

As described above, in developing a photosensitive material, a desired and appropriate developing effect can be obtained immediately after the developer is prepared. However, the development of the photosensitive material depends on the repeated development of the photosensitive material, the time elapsed after the preparation, and other factors. The developing activity of the solution decreases. Therefore, it is usual to maintain the developing activity of the developer by replenishing such a decrease in the alkaline component of the developer or a decrease due to evaporation of water. Conventionally, as a method of replenishing the developing solution, a replenishing solution (replenishing solution) necessary for processing a printing plate having a predetermined area and preventing a decrease in the sensitivity of the printing plate in the next process caused by the processing is described. ) Is actually calculated and obtained, and is converted into a necessary amount per unit area of the printing plate to be further processed. The amount of the alkaline component in the developing solution has been replenished by adding an average required amount to the developing solution. However, in such a method, when a large number of plates are processed in a short time, replenishment work is troublesome,
As described above, the addition of a pre-calculated amount of replenisher rather increases the proportion of the alkaline component, causing an apparent increase in the sensitivity of the printing plate.
As a result, the printing plate causes poor printing durability and poor inlay, and on the other hand, when only a small amount of the plate is processed for a long time, the printing plate has an apparent decrease in sensitivity. Is a printing plate characteristic,
It was supposed to stain the printed matter.

Although it is important for those skilled in the art to always keep the developing activity of a developer at a constant level,
It was quite troublesome and technically difficult. In order to solve this problem, the present inventors have added a first replenisher having an alkali strength higher than the alkali strength thereof to the developer used for the development processing every time the photosensitive material is processed. Further, a second replenisher having an alkali strength greater than the alkali strength of the developer is continuously added at a constant rate, or a constant amount is added intermittently at regular intervals. (Japanese Patent Application Laid-Open No. 55-115039). Here, the first replenisher and the second replenisher are the same.
However, as described above, there is still an inconvenience even when the two replenishing systems are used, one using the same replenisher and the other using the consumption and consumption. That is, when the photosensitive material is developed in a relatively large amount in a predetermined time, the water is replenished beyond the evaporation of the water, so that the water becomes excessive and the alkali strength becomes insufficient. On the other hand, if only a small amount of photosensitive material is developed in a given time,
The alkali content is replenished in excess of the consumed alkali content, and the alkali strength becomes excessive and the water content becomes insufficient. Under such circumstances, there is still a need for a means for maintaining the developing activity of the developer at a constant level.

[0005]

SUMMARY OF THE INVENTION The present invention provides a developing method capable of keeping the developing activity of a developing solution constant irrespective of the amount of photosensitive material to be developed within a predetermined time. It is in.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the replenishment of the developing solution by the conventional two-time system and the system using and consuming has been described. It has been found that the developing activity of the developer can be kept constant by making the replenishers different in alkali concentration. Therefore, the present invention provides a development replenisher having a different alkali concentration between a development replenisher which compensates for the decrease in the activity of the developer due to the processing of the photosensitive lithographic printing plate and a development replenisher which compensates for the decrease in the activity of the developer over time. The present invention relates to a method for developing a photosensitive lithographic printing plate, characterized in that the activity of a developer is kept constant by replenishing with a developer. The present invention also provides the above development processing method,
A concentrated lithographic printing plate comprising replenishing a developing replenisher having the same concentration of a replenisher for replenishing the decrease in activity due to processing and the decrease in activity over time, but having a different dilution ratio. The present invention relates to a developing method.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
First, examples of the developer (developer to be initially charged in the developing bath) which can be used in the developing method of the present invention include an alkali developing solution, and there is no particular limitation. It uses an alkali developing solution and adds a predetermined amount of a surfactant. The alkali developing solution (hereinafter, also simply referred to as a developer) is an aqueous alkaline solution, and can be appropriately selected from conventionally known aqueous alkaline solutions. Examples of the aqueous alkali solution include a developing solution composed of an alkali silicate or a non-reducing sugar and a base, and those having a pH of 12.5 to 13.5 are particularly preferable. As the alkali silicate, those which show alkalinity when dissolved in water, for example, sodium silicate, potassium silicate, alkali metal silicates such as lithium silicate,
Ammonium silicate and the like. The alkali silicate may be used alone or in combination of two or more.

The aqueous alkali solution is developed by adjusting the mixing ratio and concentration of silicon oxide SiO _{2 as} a component of silicate and alkali oxide M ₂ O (M represents an alkali metal or ammonium group). Sex can be easily adjusted. Among the alkaline aqueous solutions, the mixing ratio of the silicon oxide SiO ₂ and the alkaline oxide M ₂ O (Si
O ₂ / M ₂ O: molar ratio) is preferably a 0.5 to 3.0,
Those having 1.0 to 2.0 are more preferable. The SiO ₂ / M ₂ O
If the value is less than 0.5, the alkali strength is increased, so that a harmful effect of etching a general-purpose aluminum plate or the like as a support for the lithographic printing plate precursor may occur. In some cases, the developability may decrease.

The concentration of the alkali silicate in the developer is 1 to 10% by mass based on the mass of the aqueous alkali solution.
Is preferably 3 to 8% by mass, and most preferably 4 to 7% by mass. If the concentration is less than 1% by mass, developability and processing capacity may be reduced. If the concentration is more than 10% by mass, precipitates and crystals are easily formed, and gelation tends to occur during neutralization at the time of waste liquid. In some cases, waste liquid treatment may be hindered.

[0010] In a developer comprising a non-reducing sugar and a base, the non-reducing sugar means a saccharide which does not have a reducing property because it has no free aldehyde group or ketone group. Type oligosaccharides, glycosides in which a reducing group of a saccharide is bonded to a non-saccharide, and sugar alcohols obtained by hydrogenating and reducing a saccharide are classified. In the present invention, any of these can be suitably used. Examples of trehalose-type oligosaccharides include saccharose and trehalose,
Examples of the glycoside include an alkyl glycoside, a phenol glycoside, and a mustard oil glycoside. As sugar alcohols, for example, D, L-arabit, rebit,
Xylit, D, L-sorbit, D, L-unnit, D, L-idit, D, L-tallit, zuricit, allozurcit, and the like. Furthermore, maltitol obtained by hydrogenation of a disaccharide, a reductant (reduced starch syrup) obtained by hydrogenation of an oligosaccharide, and the like can also be preferably mentioned.

Among the above, as the non-reducing sugar, sugar alcohols and saccharose are preferable, and among them, D-sorbitol, saccharose and reduced starch syrup are more preferable because they have a buffering action in an appropriate pH range. These non-reducing sugars may be used alone or in combination of two or more, and the ratio in the developer is preferably 0.1 to 30% by mass, more preferably 1 to 30% by mass.
-20 mass% is more preferable.

The alkali silicate or non-reducing sugar can be combined with an alkali agent as a base by appropriately selecting it from conventionally known ones. Examples of the alkali agent include sodium hydroxide, potassium hydroxide, lithium hydroxide, trisodium phosphate, tripotassium phosphate,
Triammonium phosphate, disodium phosphate, dipotassium phosphate, diammonium phosphate, sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogen carbonate,
Examples thereof include inorganic alkali agents such as potassium hydrogen carbonate, ammonium hydrogen carbonate, sodium borate, potassium borate, and ammonium borate, potassium citrate, tripotassium citrate, and sodium citrate.

Further, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanol Organic alkali agents such as amine, ethyleneimine, ethylenediamine, pyridine and the like can also be suitably mentioned. These alkali agents may be used alone or in combination of two or more. Among them, sodium hydroxide and potassium hydroxide are preferred. The reason is that by adjusting the amount added to the non-reducing sugar,
This is because the pH can be adjusted in the region. Also,
Trisodium phosphate, tripotassium phosphate, sodium carbonate, potassium carbonate and the like are also preferable because they have a buffering action by themselves.

It is necessary to add a surfactant to the above-mentioned alkaline aqueous solution (developer). Examples of the surfactant include a nonionic surfactant, an anionic surfactant, a cationic surfactant, and an amphoteric surfactant. Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, and sorbitan fatty acid moieties. Esters, pentaerythritol fatty acid partial esters, propylene glycol monofatty acid esters,

[0015] Sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, polyoxyethylenated castor oils,
Polyoxyethylene glycerin fatty acid partial esters,
Suitable examples include fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, and trialkylamine oxides.

Examples of the anionic surfactant include fatty acid salts, abietic acid salts, hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinates, α-olefinsulfonates, linear alkylbenzenesulfonates, and branched alkylsulfonates. Chain alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl phenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyltaurine sodium salt, N-alkyl sulfosuccinate monoamide Sodium salts, petroleum sulfonates, sulfated tallow oil,
Fatty acid alkyl ester sulfates, alkyl sulfates, polyoxyethylene alkyl ether sulfates,

Fatty acid monoglyceride sulfate salts,
Polyoxyethylene alkyl phenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, styrene / anhydrous Preferable examples include partially saponified maleic acid copolymers, partially saponified olefin / maleic anhydride copolymers, and formalin condensates of naphthalenesulfonic acid salts.

Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts such as tetrabutylammonium bromide, polyoxyethylene alkylamine salts, and polyethylenepolyamine derivatives. Examples of the amphoteric surfactant include carboxybetaines, alkylaminocarboxylic acids, sulfobetaines, aminosulfates, and imidazolines. Among the above surfactants, those referred to as `` polyoxyethylene '' can be read as polyoxyalkylenes such as polyoxymethylene, polyoxypropylene, and polyoxybutylene, which are also included in the surfactants. You. The concentration of the surfactant in the developer is preferably 0.001 to 10% by mass, and 0.000 to 10% by mass.
The content is more preferably from 5 to 1% by mass, and most preferably from 0.01 to 0.5% by mass.

The developing replenisher used in the method of the present invention is generally one in which a concentrated stock solution for the replenisher is diluted with water and supplied to a developing bath. The present invention is characterized in that the alkali concentration of the developing replenisher replenished according to the processing amount of the photosensitive lithographic printing plate is different from the alkali concentration of the developing replenisher replenished over time. That is, using one kind of concentrated stock solution for replenisher, changing the dilution ratio, one is a replenisher replenished according to the processing amount of the photosensitive lithographic printing plate, and the other is a replenisher replenished over time. It can be a liquid.

The replenisher replenished in accordance with the processing amount of the photosensitive lithographic printing plate used in the present invention and the replenisher replenished in accordance with the passage of time are both alkali developing solution charged in a developing bath at the beginning of development. It has a higher alkali strength than the liquid. Each replenisher is an aqueous solution of an alkaline substance similar to the components of the developer described above. The alkaline substance used in each replenisher may be the same as or different from the alkaline substance used in the developer. Further, the composition may be the same or different. The same is true for each replenisher. Each replenisher can be prepared by using one kind of concentrated stock solution for replenisher and changing the dilution ratio. Alternatively, each replenisher may be prepared by adjusting the alkali concentration and the mixing ratio (SiO ₂ / M ₂ O) according to a conventional method, but the two have different alkali concentrations. In the replenisher replenished according to the processing amount of the photosensitive lithographic printing plate used in the method of the present invention, the concentration of the alkaline substance is 1 to 1
0 mass% is appropriate, and preferably 3 to 8 mass%. More preferably, it is 4 to 6% by mass. On the other hand, the concentration of the alkaline substance in the replenisher replenished with the passage of time is suitably 1 to 10% by mass, and preferably 1 to 6% by mass. More preferably, it is 2 to 4% by mass.

The concentration of the surfactant in the developing replenisher must be higher than the initial concentration of the alkali developing solution, preferably 1.2 to 50 times, more preferably 2 to 50 times. 25 times, more preferably 3 to 1 times.
5 times the amount. If the concentration of the surfactant is equal to or lower than the initial concentration of the alkali developer, the effect of suppressing the dissolution of the unexposed portion is deteriorated. This surfactant concentration is 1.
When the concentration is more than 2 times, the effect of improving the concentration of the surfactant becomes remarkable, and when the concentration is increased more than 50 times, the effect is not improved, and the developability of the exposed portion may be deteriorated. Therefore, it is not preferable. By using a replenisher with a high surfactant concentration, the surfactant to maintain the balance of developability compensates for the deterioration of the function due to the effects of insolubles and elutes of the active ingredient, and always maintains a certain function. Can be developed, and plate making with good developing performance and a good balance of image areas / non-image areas can be stably performed over a long period of time.

The following additives can be added to the alkali developing solution and the developing replenisher for the purpose of further improving the developing performance. For example, neutral salts such as NaCl, KCl and KBr described in JP-A-58-75152, EDTA and NTA described in JP-A-58-90952.
Chelating agents such _{as, [Co (NH 3) 6} ] described in _{JP-A-59-121336 Cl 3, CoCl 2 · 6H} 2 O
Complexes, such as sodium alkylnaphthalenesulfonate described in JP-A-50-51324;
No. 946, a cationic polymer such as a methyl chloride quaternary compound of p-dimethylaminomethyl polystyrene, a copolymer of vinylbenzyltrimethylammonium chloride and sodium acrylate described in JP-A-56-142528, and the like. Amphoteric polymer electrolyte,
Reducing inorganic salts such as sodium sulfite described in JP-A-57-192951, inorganic lithium compounds such as lithium chloride described in JP-A-58-59444, and inorganic lithium compounds described in JP-A-59-84241. And organic boron compounds.

Various organic solvents and the like may be added to the developing solution and the developing replenisher as needed for the purpose of promoting or suppressing the developing property, dispersing the developing residue and improving the ink affinity of the printing plate image area. You can also. Benzyl alcohol and the like are preferable as such an organic solvent. If necessary, an inorganic salt-based reducing agent such as hydroquinone, resorcinol, sodium or potassium sulfite or bisulfite, an organic carboxylic acid, an antifoaming agent, and a water softener can also be added.

The method of adding a developing replenisher used in the present invention can be applied to both conventional dish development and development by an automatic developing machine. The addition of the replenisher may be performed manually, or may be performed using a machine, a device, or the like. However, in the method according to the present invention, since the addition is performed in two lines, that is, a system based on use and consumption and a system over time, in practice, manual operations involve considerable trouble and difficulty. Therefore, it is preferable to design and manufacture the addition device before use. According to this addition device, it can be preferably carried out for both dish development and automatic developing machines. The addition device itself is conventionally known. Therefore, it seems easy to design and fabricate a device having the desired function to implement the method of the present invention.

According to the present invention, as a method of adding a replenisher replenished according to the processing amount of a photosensitive lithographic printing plate, for example, when an automatic developing machine is used, a photosensitive material to be developed by the automatic developing machine is supplied. A switch for detecting insertion or running is arranged at a portion where the photosensitive material travels in the automatic developing solution, and this switch is pressed to supply a predetermined amount of the replenishing solution from the replenishing solution bath to the developing solution bath. .
This is based on the discovery by the present inventors that the necessary and sufficient amount of the replenisher can be measured from the length of one side of the light-sensitive material to be processed. Another method is to optically measure the area of the non-image area after development of the photosensitive material, electrically process the analog output by the photoelectric conversion mechanism, and electrically operate the replenisher supply mechanism. There is also a way to do this. When using a measuring cup, for example, in the case of plate development, a scale for measuring the length of one side of the photosensitive material is provided inside the plate, and a scale for the amount of addition corresponding to the scale of the length is provided. If necessary, it is possible to easily add a necessary and sufficient replenisher for each developing operation. This applies the findings of the present inventors to dish development.

On the other hand, the method of adding the replenisher replenished with the passage of time is simpler than the replenisher replenished in accordance with the processing amount of the photosensitive lithographic printing plate. This is because a constant flow rate of the replenisher may be continuously supplied, or a predetermined amount of the replenisher may be added at regular intervals. This can also be added in a measuring cup, but it is unavoidable that the operation is troublesome, and an electric or mechanical device should also be used. Precise metering and supply can be easily performed by using a chemical pump or a metering pump. The design and manufacture of the device for supplying the replenisher is easy from the prior art.

The present invention is intended to maintain the activity level of the developer by using replenishers having different alkali concentrations in two series of replenishment against the fatigue of the developer. Accordingly, the photosensitive lithographic printing plate to which the developing method of the present invention can be applied is not particularly limited, and a conventional positive / negative photosensitive lithographic printing plate, photopolymerizable photosensitive lithographic printing plate, positive / negative photosensitive lithographic printing plate can be used. Type infrared sensitive lithographic printing plate. Hereinafter, various photosensitive lithographic printing plates and supports will be described.

[0028]

[Positive- and negative-type photosensitive lithographic printing plates] Representative photosensitive materials are as follows. (A) Photosensitive layer composed of o-quinonediazide compound Examples of the photosensitive compound of the positive photosensitive composition include o-quinonediazide compounds, and representative examples thereof include o-naphthoquinonediazide compounds. The o-naphthoquinonediazide compound is preferably an ester of 1,2-diazonaphthoquinonesulfonic acid chloride and pyrogallol-acetone resin described in JP-B-43-28403. Other suitable o-quinonediazide compounds include U.S. Pat. No. 3,046,1.
There is an ester of 1,2-diazonaphthoquinonesulfonic acid chloride and a phenol-formaldehyde resin described in JP-A Nos. 20 and 3,188,210. Other useful o-naphthoquinonediazide compounds include those reported and known in numerous patents.

For example, see JP-A-47-5303 and JP-A-48-303.
-63802, 48-63803, 48-96
No. 575, No. 49-38701, No. 48-13354
No., JP-B-37-18015, 41-11222
No. 45-9610, No. 49-17481,
U.S. Pat. Nos. 2,797,213 and 3,454,4
No. 00, No. 3,544,323, No. 3,573
No. 917, No. 3,674,495, No. 3, 78
5,825, British Patent Nos. 1,227,602, 1,251,345, 1,267,005, 1,329,888, and 1,330,932. ,
Examples described in each specification such as German Patent No. 854,890 can be given.

Particularly preferred o-naphthoquinonediazide compounds are compounds obtained by reacting a polyhydroxy compound having a molecular weight of 1,000 or less with 1,2-diazonaphthoquinonesulfonic acid chloride. Specific examples of such compounds are described in JP-A-51-139402 and JP-A-58-1.
No. 50948, No. 58-203434, No. 59-16
No. 5053, No. 60-112445, No. 60-134
No. 235, No. 60-163430, No. 61-1187
No. 44, No. 62-10645, No. 62-10646
Nos. 62-153950 and 62-178562
No. 64-76047, U.S. Pat. No. 3,102,8
No. 09, No. 3,126,281, No. 3,130,
No. 047, No. 3,148,983, No. 3,18
No. 4,310, No. 3,188,210, No. 4,6
39, 406 and the like, and those described in each gazette or specification.

When synthesizing these o-naphthoquinonediazide compounds, it is preferable to react 0.2 to 1.2 equivalents of 1,2-diazonaphthoquinonesulfonic acid chloride with respect to the hydroxyl group of the polyhydroxy compound. .3
More preferably, the reaction is carried out in an amount of up to 1.0 equivalent. 1,2-diazonaphthoquinonesulfonic acid chloride includes 1,2
-Diazonaphthoquinone-5-sulfonic acid chloride or 1,2-diazonaphthoquinone-4-sulfonic acid chloride can be used. The obtained o-naphthoquinonediazide compound is a mixture of various compounds having different positions and introduced amounts of 1,2-diazonaphthoquinonesulfonic acid ester groups.
The proportion of the compound converted to the diazonaphthoquinone sulfonic acid ester in this mixture (the content of the completely esterified compound) is preferably 5 mol% or more, more preferably 20 to 99 mol%. It is.

As a photosensitive compound which acts positively without using an o-naphthoquinonediazide compound, for example, a polymer compound having an o-nitrocarbinol ester group described in JP-B-56-2696 may also be used. Can be. Further, a compound generating an acid by photolysis and a -CO-C- group or -CO-
A combination system with a compound having a Si group can also be used.
For example, a combination of a compound that generates an acid by photolysis and an acetal or an O, N-acetal compound (Japanese Patent Application Laid-Open No.
No. 8-89003), a combination with an orthoester or an amide acetal compound (JP-A-5120720).
No.), a combination with a polymer having an acetal or ketal group in the main chain (JP-A-53-133425), a combination with an enol ether compound (JP-A-55-1)
No. 2995), a combination with an N-acylimino carbon compound (JP-A-55-126236), and a combination with a polymer having an orthoester group in the main chain (JP-A-56-126).
-17345), a combination with a silyl ester compound (JP-A-60-10247) and a combination with a silyl ether compound (JP-A-60-37549, JP-A-60-112446).

The amount of these positive-acting photosensitive compounds (including the above combinations) in the photosensitive composition of the photosensitive layer is suitably from 10 to 50% by mass, more preferably from 15 to 50% by mass. 40% by mass. Although the o-quinonediazide compound alone can constitute the photosensitive layer, it is preferably used together with a resin soluble in alkaline water as a binder. Examples of such a resin soluble in alkaline water include a novolak resin having this property. Cresol (m-, p- or m
-/ P-mixing) Cresol formaldehyde resin such as mixed formaldehyde resin, phenol-modified xylene resin, polyhydroxystyrene, polyhalogenated hydroxystyrene, JP-A-51-34711
Various alkali-soluble resins such as an acrylic resin containing a phenolic hydroxyl group, an acrylic resin having a sulfonamide group described in JP-A-2-866, a urethane-based resin, and the like, as disclosed in Japanese Patent Application Laid-open No. A polymer compound can be contained. These alkali-soluble polymer compounds preferably have a mass average molecular weight of 500 to 20,000 and a number average molecular weight of 200 to 60,000.

Such an alkali-soluble polymer compound is used in an amount of not more than 70% by mass of the total composition.
Further, as described in U.S. Pat. No. 4,123,279, phenol having a C3-8 alkyl group as a substituent, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, and formaldehyde are used. It is preferred to use a condensate with the above in order to improve the oil sensitivity of the image.

To enhance the sensitivity, cyclic acid anhydrides, a printing-out agent for obtaining a visible image immediately after exposure, a dye as an image coloring agent and other fillers can be added. US Pat. No. 4,115,128 discloses cyclic acid anhydrides.
Phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-endooxy- ヒ ド ロ⁴ -tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride described in US Pat. , Α-phenyl maleic anhydride, succinic anhydride,
Pyromellitic anhydride and the like can be used. By containing these cyclic acid anhydrides in an amount of 1 to 15% by mass based on the total mass of the composition, sensitivity can be increased up to about three times. As a printing-out agent for obtaining a visible image immediately after exposure, a combination of a photosensitive compound that releases an acid upon exposure and an organic dye capable of forming a salt can be exemplified.

Specifically, JP-A-50-36209,
Combinations of o-naphthoquinonediazide-4-sulfonic acid halogenide and salt-forming organic dyes described in each publication of JP-A-53-8128, JP-A-53-36223, JP-A-54-74728, and JP-A-53-74828. No. 3626, 61-1
Nos. 43748, 61-151644 and 63-
Combinations of a trihalomethyl compound and a salt-forming organic dye described in each of JP-A-58440 can be mentioned. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent temporal stability and give clear print-out images.

As the colorant for the image, other dyes can be used in addition to the above-mentioned salt-forming organic dyes. 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 (all manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), malachite green (CI42000), methylene blue (CI5201)
5) and the like. Also, Japanese Unexamined Patent Publication No. Sho 62-2
The dyes described in JP 93247 A are particularly preferred.

The photosensitive composition of the photosensitive layer is dissolved in a solvent in which the above-mentioned components are dissolved, and coated on a support. As the solvent used here, ethylene dichloride, cyclohexanone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, 1-methoxy-
2-propanol, 1-methoxy-2-propyl acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, dimethyl sulfoxide, dimethylacetamide, dimethylformamide, water, N-methylpyrrolidone, tetrahydrofurfuryl alcohol, acetone, diacetone alcohol , Methanol, ethanol, isopropanol, diethylene glycol, dimethyl ether and the like, and these solvents are used alone or as a mixture. The concentration (solid content) of the above components in the solution is 2 to 50.
% By mass. The amount of application varies depending on the application, but for example, when it comes to photosensitive lithographic printing plates, it is generally 0.
5 to 3.0 g / m ² is preferred. As the amount of application decreases, the photosensitivity increases, but the physical properties of the photosensitive film decrease. To the photosensitive composition, a surfactant for improving coating properties, for example, a fluorine-based surfactant described in JP-A-62-170950 can be added. The preferable addition amount is 0.01 to 1 in the entire photosensitive composition.
%, More preferably 0.05 to 0.5% by mass.

(B) Photosensitive Layer Consisting of Diazo Resin and Binder A negative working photosensitive diazo compound is disclosed in US Pat.
Diphenylamine which is a reaction product of a diazonium salt described in JP-A Nos. 063,631 and 2,667,415 with an organic condensing agent having a reactive carbonyl group such as aldol or acetal. A condensation product of a p-diazonium salt and formaldehyde (a so-called photosensitive diazo resin) is preferably used. Other useful condensed diazo compounds are disclosed in JP-B-49-48001 and JP-B-49-48001.
-45322 and 49-45323. These types of photosensitive diazo compounds are usually obtained in the form of water-soluble inorganic salts and can therefore be applied from aqueous solutions. Further, these water-soluble diazo compounds are reacted with an aromatic or aliphatic compound having one or more phenolic hydroxyl groups, sulfonic acid groups or both by a method disclosed in Japanese Patent Publication No. 47-1167,
A substantially water-insoluble photosensitive diazo resin, which is the reaction product, can also be used.

As described in JP-A-56-121031, it can be used as a reaction product with a hexafluorophosphate or a tetrafluoroborate. Examples of reactants having a phenolic hydroxyl group include hydroxybenzophenone, 4,4-bis (4 '
-Hydroxyphenyl) pentanoic acid, resorcinol,
Or a diphenolic acid such as diresorcinol, which may further have a substituent. Hydroxyfenzophenone includes 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone or 2,2 ', 4,4'-tetrahydroxybenzophenone Is included. Preferred sulfonic acids include, for example, aromatic sulfonic acids such as sulfonic acids such as benzene, toluene, xylene, naphthalene, phenol, naltol and benzophenone, or soluble salts thereof, for example, ammonium and alkali metal salts.

The sulfonic acid group-containing compound may be generally substituted with a lower alkyl, a nitro group, a halo group, and / or another sulfonic acid group. Preferred examples of such a compound include benzenesulfonic acid, toluenesulfonic acid, naphthalenesulfonic acid, 2,5-dimethylbenzenesulfonic acid, sodium benzenesulfonic acid,
Naphthalene-2-sulfonic acid, 1-naphthol-2 (or 4) -sulfonic acid, 2,4-dinitro-1-naphthol-7-sulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, m -(P'-anilinophenylazo) benzenesulfonic acid sodium, alizarinsulfonic acid, o-toluidine-m-sulfonic acid and ethanesulfonic acid. Also useful are the sulfonic esters of alcohols and their salts. Such compounds are usually readily available as anionic surfactants. Examples thereof include ammonium salts or alkali metal salts such as lauryl sulfate, alkylaryl sulfate, p-nonylphenyl sulfate, 2-phenylethyl sulfate, and isooctylphenoxydiethoxyethyl sulfate.

These substantially water-insoluble photosensitive diazo resins are formed as a precipitate by mixing the water-soluble photosensitive diazo resin with the above-mentioned aqueous solution of the aromatic or aliphatic compound, preferably in substantially equivalent amounts. Isolated. Further, diazo resins described in British Patent No. 1,312,925 are also preferable. Also, a diazo resin containing an oxygen acid group of phosphorus described in JP-A-3-253857, and a diazo resin condensed with a carboxyl-containing aldehyde or an acetal compound thereof described in JP-A-04-018559. Resin, and JP-A-04-21
Also preferred are co-condensed diazo resins with carboxy group-containing aromatic compounds such as phenoxyacetic acid described in No. 1253 and JP-A-05-002273.

The content of the diazo resin is 5 to 5 in the photosensitive layer.
Suitably, it is contained at 0% by mass. When the amount of the diazo resin decreases, the photosensitivity naturally increases, but the stability with time decreases. The optimal amount of diazo resin is about 8-20% by weight. On the other hand, as the binder, various polymer compounds can be used, but hydroxy, amino, carboxylic acid,
Those containing a group such as amide, sulfonamide, active methylene, thioalcohol, epoxy and the like are desirable. Such preferred binders include British Patent 1,350,5.
No. 21,460,978 and U.S. Pat. No. 4,123,27.
6, a polymer containing a hydroxyethyl acrylate unit or a hydroxyethyl methacrylate unit as a main repeating unit, a polyamide resin described in U.S. Pat. No. 3,751,257, Phenolic and polyvinyl formal resins described in GB 1,074,392, polyvinyl acetal resins such as polyvinyl butyral resin, and US Pat. No. 3,660,097. Linear polyurethane resin, phthalated resin of polyvinyl alcohol, epoxy resin condensed from bisphenol A and epichlorohydrin, polymer containing amino group such as polyaminostyrene and polyalkylamino (meth) acrylate, cellulose acetate,
Cellulose derivatives such as cellulose alkyl ether and cellulose acetate phthalate are included. Compositions comprising a diazo resin and a binder further include a pH indicator as described in British Patent 1,041,463 and US Pat. No. 3,236,646. Additives such as phosphoric acid and dyes can be added.

(C) Photosensitive layer comprising azide compound and binder (high molecular compound) For example, British Patent Nos. 1,235,281 and 1,491
5,861 and JP-A-51-32331.
And the compositions comprising an azide compound and a water-soluble or alkali-soluble polymer compound described in JP-A Nos.
No.4302, No.50-84303, No.53-1298
A composition comprising a polymer containing an azide group and a polymer compound as a binder described in each of the publications of No. 4 and the like is included.

(D) Other photosensitive resin layers For example, polyester compounds disclosed in JP-A-52-96696, British Patent No. 1,112,277
No. 1,313,390 and 1,341,00
No. 4,377,747, etc., polyvinyl cinnamate resin described in each specification, US Pat.
Photopolymerized photopolymer compositions described in the specifications of 2,528 and 4,072,527 are included.

(E) Electrophotographic Photosensitive Layer The electrophotographic photosensitive layer mainly comprises a photoconductive compound and a binder. For the purpose of improving sensitivity and obtaining a desired photosensitive wavelength range, a known electrophotographic photosensitive layer may be used. Pigments, dyes, chemical sensitizers, other additives and the like can be used.
The photosensitive layer can be composed of a single layer or a plurality of layers having separate functions of charge generation and charge transport. A lithographic printing plate can be obtained by forming a toner image on a photosensitive layer by a known electrophotographic process, using this as a resist layer, and removing the photosensitive layer in the non-image area. Such a photosensitive layer is described, for example, in JP-B-37-17162 and JP-B-38.
-6961, JP-A-56-107246, and JP-A-60-107246.
254142, JP-B-59-36259, and 59-
No. 25217, JP-A-56-146145, and JP-A-62-146145.
No. 194257, No. 57-147656, No. 58-1
No. 00862, 57-161863, and many other publications, all of which can be suitably used.

The photosensitive layer may have a thickness of 0.1 to 30 μm, more preferably 0.5 to 10 μm. The amount of the photosensitive layer provided on the support (solid content) is from about 0.1 to about 7 g / m ^2, preferably in the range of 0.5-4 g / m ^2. It is preferable to provide a mat layer on the surface of the photosensitive layer of the photosensitive lithographic printing plate in order to shorten the time of evacuation and prevent baking in the case of close contact exposure using a vacuum printing frame. Specifically, JP-A-50-125805, JP-B-57-66-1
Nos. 582 and 61-28986, a method of providing a mat layer as described in JP-B-62-623.
No. 37, a method of thermally fusing a solid powder, and the like.

Other photosensitive materials are described below.

[Photopolymerizable photosensitive lithographic printing plate] As a typical one,
(A) an addition-polymerizable compound having at least one ethylenically unsaturated double bond, a photopolymerization layer containing a photopolymerization initiator and a polymer binder, and (B) a water-soluble vinyl polymer on the polymerization layer. There is a negative photosensitive material comprising a protective layer containing a coalescence. (A) A photopolymerizable layer containing an addition-polymerizable compound having at least one ethylenically unsaturated double bond, a photopolymerization initiator, and a polymer binder. The main components of the photopolymerizable layer are an addition-polymerizable compound having at least one ethylenically unsaturated double bond, a photopolymerization initiator and a polymer binder, and if necessary, a thermal polymerization inhibitor, a coloring agent, Various compounds such as a plasticizer can be contained.

The compound capable of addition polymerization containing an ethylenically unsaturated double bond can be arbitrarily selected from compounds having at least one, and preferably two or more, terminal ethylenically unsaturated bonds. These compounds include:
For example, those having a chemical form such as a monomer, a prepolymer such as a dimer or a trimer, and an oligomer, or a mixture thereof are included. Examples of these include esters of unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) with aliphatic polyhydric alcohol compounds, these unsaturated carboxylic acids and Examples thereof include amides with aliphatic polyamine compounds.

Specific examples of the monomer of the ester of the aliphatic polyhydric alcohol compound and the unsaturated carboxylic acid include ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3
-Butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate 1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate , So Bi penta acrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomers and the like.

Examples of the methacrylic acid ester include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol. Dimethacrylate, hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3- Methacryloxy-2-hi Rokishipuropokishi) phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane, and the like.

Examples of itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
Examples thereof include 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, and sorbitol tetritaconate. The crotonic acid ester includes ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, sorbitol tetradicrotonate and the like. As isocrotonic acid esters, ethylene glycol diisocrotonate, pentaerythritol diisocrotonate,
Sorbitol tetraisocrotonate and the like.

The maleic acid ester includes ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, sorbitol tetramaleate and the like. Furthermore, a mixture of the above-mentioned ester monomers can also be mentioned. Further, specific examples of the amide monomer of the aliphatic polyamine compound and the unsaturated carboxylic acid include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis -Methacrylamide, diethylenetriaminetrisacrylamide, xylylenebisacrylamide, xylylenebismethacrylamide and the like. As another example, a polyisocyanate compound having two or more isocyanate groups in one molecule described in JP-B-48-41708 is added with a vinyl monomer having a hydroxyl group represented by the following general formula. 1 added
Examples include vinyl urethane compounds having two or more polymerizable vinyl groups in the molecule. General formula CH ₂ CC (R) COOCH ₂ CH (R ′) OH (where R and R ′ represent H or CH ₃ )

Further, urethane acrylates as described in JP-A-51-37193,
64183, JP-B-49-43191, JP-B-52
And polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid as described in JP-A-30490. In addition, Journal of the Adhesion Society of Japan vol. 20, No. 7, 300-30
Those introduced as photocurable monomers and oligomers on page 8 (1984) can also be used. The amount of these used is 5 to 70% by mass (hereinafter abbreviated as%), preferably 10 to 50%, based on the total solid content of the photopolymerizable layer.

Examples of the photopolymerization initiator include various photoinitiators known in patents and literatures depending on the wavelength of the light source used.
Alternatively, a combination system (photoinitiating system) of two or more photoinitiators can be appropriately selected and used. For example, when ultraviolet light of 400 nm or less is used as a light source, benzyl, benzoin ether, Michler's ketone, anthraquinone, acridine, phenazine, benzophenone, and the like are widely used. Also, when using visible light of 400 nm or less, an argon laser, and a YAG-SHG laser as a light source,
Various photoinitiating systems have been proposed, for example, certain photosensitive dyes and complex starting systems of dyes and amines described in U.S. Pat. No. 2,850,445 (JP-B-44-20189).
No.), a combination system of hexaarylbiimidazole, a radical generator and a dye (JP-B-45-37377), and a system of hexaarylbiimidazole and p-dialkylaminobenzylidene ketone (JP-B-47-2528; No. 54-155292), a system of a cyclic cis-α-dicarbonyl compound and a dye (JP-A-48-84183), a system of a cyclic triazine and a merocyanine dye (JP-A-54-15).
1024), a system of 3-ketocoumarin and an activator (Japanese Patent Application Laid-Open Nos. 52-112681 and 58-15503),
System of biimidazole, styrene derivative, thiol (JP-A-59-140203), system of organic peroxide and dye (JP-A-59-140203, JP-A-59-1893)
No. 40), a system of a dye having a rhodanine skeleton and a radical generator (JP-A-2-244050), a system of a titanocene and a 3-ketocoumarin dye (JP-A-63-221110), a titanocene and a xanthene dye, and an amino group or urethane Systems in which an addition-polymerizable ethylenically unsaturated compound containing a group is combined (JP-A-4-221958, JP-A-4-221958)
No. 219756) and a system of titanocene and a specific merocyanine dye (JP-A-6-295061). The amount of the photopolymerization initiator used is 0.05 to 100 parts by mass based on 100 parts by mass of the ethylenically unsaturated compound.
It can be used in an amount of from 0.1 to 70 parts by mass, more preferably from 0.2 to 50 parts by mass.

The above-mentioned photopolymerized layer usually contains a linear organic high molecular polymer as a binder. Any one may be used as long as it is a linear organic high molecular polymer having solubility. Preferably, a water- or weakly alkaline water-soluble or swellable linear organic high molecular polymer that enables water development or weakly alkaline water development is selected. The linear organic high molecular polymer is selected and used not only as a film-forming agent of the composition but also as a developer for water, weakly alkaline water or an organic solvent. For example, when a water-soluble organic high molecular polymer is used, water development becomes possible. Examples of such a linear organic high molecular polymer include addition polymers having a carboxylic acid group in a side chain, for example, JP-A-59-44615, JP-B-54-34327,
JP-B-58-12577, JP-B-54-25957
JP-A-54-92723 and JP-A-59-5383.
No. 6, JP-A-59-71048, that is, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, crotonic acid copolymer, maleic acid copolymer, There are esterified maleic acid copolymers and the like.

Similarly, there is an acidic cellulose derivative having a carboxylic acid group in the side chain. In addition, those obtained by adding a cyclic acid anhydride to an addition polymer having a hydroxyl group are useful. Particularly, among these, [benzyl (meth) acrylate / (meth) acrylic acid / optionally other addition-polymerizable vinyl monomers] copolymer and [allyl (meth) acrylate (meth) acrylic acid / optionally Other addition-polymerizable vinyl monomers] copolymers are preferred. In addition, polyvinyl pyrrolidone and polyethylene oxide are useful as the water-soluble linear organic polymer. In order to increase the strength of the cured film, an alcohol-soluble polyamide, a polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful. These linear organic high molecular polymers can be mixed in an arbitrary amount with the total solid content of the photopolymerizable layer. However, if the content exceeds 90% by mass, no favorable result is obtained in view of the strength of the formed image and the like. Preferably it is 30 to 85%.
Further, the mass ratio of the photopolymerizable ethylenically unsaturated compound and the linear organic high molecular polymer is preferably in the range of 1/9 to 7/3. A more preferred range is 2/8 to 6/4.

The photopolymerizable layer may contain a small amount of a thermal polymerization inhibitor in addition to the above basic components in order to prevent unnecessary thermal polymerization of the polymerizable ethylenically unsaturated compound during the production or storage of the photosensitive material. It is desirable to add. Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-tert-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-
Thiobis (3-methyl-6-t-butylphenol),
2,2'-methylenebis (4-methyl-6-t-butylphenol), cerium N-nitrosophenylhydroxylamine and the like. The addition amount of the thermal polymerization inhibitor is about 0.01% based on the total solid content of the photopolymerization layer.
~ 5% is preferred. Also, if necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide may be added to prevent polymerization inhibition by oxygen, and may be unevenly distributed on the surface of the photopolymerization layer in a drying process after coating. Good. The addition amount of the higher fatty acid derivative is preferably about 0.5% to about 10% of the whole composition.

Further, a coloring agent may be added for the purpose of coloring the photopolymerizable layer. Examples of the coloring agent include phthalocyanine pigments, azo pigments, pigments such as carbon black and titanium oxide, ethyl violet, crystal violet, azo dyes, anthraquinone dyes, and cyanine dyes. The amount of dyes and pigments added is preferably about 0.5% to about 5% of the total solids. In addition, additives such as an inorganic filler and a plasticizer such as dioctyl phthalate, dimethyl phthalate and tricresyl phosphate may be added in order to improve the physical properties of the cured film. The addition amount of these is preferably 10% or less of the total solid content of the photopolymerization layer.

The above photopolymerized layer is usually used after being coated on a support. When coating on a support, various organic solvents can be used. As the organic solvent used herein, acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether Acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethylene glycol monomethyl ether , Diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxypropyl acetate, N,
N-dimethylformamide, dimethyl sulfoxide, γ
-Butyrolactone, methyl lactate, ethyl lactate and the like. These solvents can be used alone or as a mixture. And the concentration of solids in the coating solution is 2
~ 50 mass% is preferred.

A surfactant can be added to the photopolymerizable layer in order to improve the coated surface quality. The coating amount of the mass range of from about 0.1 g / m ² ~ about 10 g / m ² by preferably after drying, 0.5 to 5 g / m ² is more preferable.

(B) Protective Layer Containing Soluble Vinyl Polymer Next, the protective layer containing a water-soluble vinyl polymer applied on the photopolymerizable layer will be described. Examples of the water-soluble vinyl polymer contained in the protective layer include polyvinyl alcohol, a partial ester or ether thereof, and polyvinyl acetal. Other useful polymers include polyvinylpyrrolidone, gelatin and gum arabic, and these may be used alone or in combination. Still further, a copolymer of the above polymer containing an unsubstituted vinyl alcohol unit in an amount substantially necessary for imparting water solubility may be mentioned.

As the polyvinyl alcohol, 71 to 1
Those having a hydrolysis degree of 00% and a degree of polymerization in the range of 300 to 2400 are preferred. Specifically, Kuraray Co., Ltd. PVA-
105, PVA-110, PVA-117, PVA-117H, PVA-
120, PVA-124, PVA-124H, PVA-CS, PVA-CST,
PVA-HC, PVA-203, PVA-204, PVA-205, PVA-2
10, PVA-217, PVA-220, PVA-224, PVA-21
7EE, PVA-220, PVA-224, PVA-217EE, PVA-2
17E, PVA- 220E, PVA- 224E, PVA- 405, PV
A-420, PVA-613, L-8 and the like. Examples of the above-mentioned copolymer include polyvinyl acetate chloroacetate or propionate, polyvinyl formal and polyvinyl acetal hydrolyzed by 88 to 100%, and copolymers thereof. In the light-sensitive material, the water-soluble vinyl polymer is contained in the protective layer at a ratio of 30 to 99%, preferably 50 to 99%, based on the total solid content of the protective layer.

The dry coating weight of the protective layer is usually 0.1.
5 to 10 g / m ² , preferably 1.0 to 5.0 g
/ M ² . The method of applying the protective layer is not particularly limited, and is disclosed in U.S. Pat.
The method described in 5-49729 can be applied. Water is used as a solvent at the time of coating. Known additives such as a surfactant for improving coating properties and a water-soluble plasticizer for improving physical properties of the film may be added to the protective layer. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, and sorbitol. Further, a water-soluble (meth) acrylic polymer or the like may be added.
The protective layer has good adhesion to the photopolymerizable layer, is water-soluble, and has oxygen barrier properties. It is transparent to actinic rays.

[0065]

[Infrared-sensitive lithographic printing plate] A lithographic printing plate having an image-forming layer containing an infrared absorber has an image-forming layer on a support, and further has other layers as necessary. The forming layer has (A) an infrared absorbing agent, and is further compatible with at least (B) an alkali-soluble polymer compound and (C) an alkali-soluble polymer compound to dissolve the alkali-soluble polymer compound in an aqueous alkali solution. And a compound that reduces the solubility lowering effect by heating. In the case of a negative type lithographic printing plate precursor, since the exposed portion is cured to form an image portion, the image forming layer further comprises (D) a compound which generates an acid by heat,
(E) a crosslinking agent that is crosslinked by an acid. Hereinafter, each component will be briefly described.

-(A) Infrared Absorber- An infrared absorber (hereinafter sometimes referred to as "(A)" component) has a function of converting absorbed infrared rays into heat. As the infrared absorbing agent that can be used, a dye or a pigment capable of highly efficiently absorbing infrared rays in a wavelength region of 700 nm or more, preferably in a wavelength region of 750 nm to 1200 nm, is preferable. Dyes or pigments are more preferred.

Examples of the dye material include commercially available dyes and known dyes described in literatures (for example, “Dye Handbook”, edited by The Society of Synthetic Organic Chemistry, published in 1970). Dyes such as dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, cyanine dyes, squalylium dyes, pyrylium salts, metal thiolate complexes and the like can be mentioned.

Among them, for example, Japanese Patent Application Laid-Open No. 58-12524
No. 6, JP-A-59-84356, JP-A-59-202
No. 829, JP-A-60-78787, JP-A-58-173696, JP-A-58-1.
Methine dyes described in JP-A-81690, JP-A-58-194595, JP-A-58-112793, JP-A-58-112793, and
Naphthoquinone dyes described in JP-A-224793, JP-A-59-48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, and JP-A-58-112792. The squarylium dye described in US Pat. No. 4,434,875, and the dihydroperimidine squarylium dye described in US Pat. No. 5,380,635 are preferred.

Further, a near-infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferable, and a substituted aryl benzo (thiol) described in US Pat. No. 3,881,924 is preferable. ) Pyrylium salts, JP-A-57-1426
No. 45 (U.S. Pat. No. 4,327,169), a trimethinethiapyrylium salt described in JP-A-58-1810.
No. 51, No. 58-220143, No. 59-41363
Nos. 59-84248, 59-84249, 59-146063 and 59-146061; pyrylium compounds described in JP-A-59-216146; cyanine dyes described in JP-A-59-216146; U.S. Pat. Nos. 283,475 and pentamethine thiopyrium salts, and the pyrylium compounds described in JP-B-5-13514 and 5-19702; commercially available products include Epolight III-178, E
polight III-130, Epolight III-125, Epolight
IV-62A (Eporin) and the like are also preferable.

Further, near infrared absorbing dyes represented by formulas (I) and (II) described in US Pat. No. 4,756,993 can also be mentioned as suitable ones. Among the above, a cyanine dye, a squarylium dye, a pyrylium salt, and a nickel thiolate complex are more preferable.

Examples of the pigment include commercially available pigments or Color Index (CI) Handbook, “Latest Pigment Handbook” (edited by Japan Pigment Technical Association), published in 1977, “Latest Pigment Application Technology” (CMC Publishing, 1986). And pigments described in “Printing Ink Technology” (CMC Publishing, 1984), for example, black pigment, yellow pigment, orange pigment, brown pigment, red pigment, purple pigment, blue pigment, green pigment, Examples include fluorescent pigments, metal powder pigments, and other polymer-bound dyes.

Specifically, for example, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalosinine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, Isoindolinone pigments, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments,
Examples include inorganic pigments and carbon black. Among them,
Carbon black is preferred.

The pigment may be used without being subjected to a surface treatment, or may be used after being subjected to a surface treatment. As a method of surface treatment, a method of surface coating a resin or wax,
Examples include a method of attaching a surfactant, and a method of bonding a reactive substance (for example, a silane coupling agent, an epoxy compound, or a polyisocyanate) to the pigment surface.
These surface treatment methods are described in "Properties and Applications of Metallic Soaps"
(Koshobo), "Printing ink technology" (CMC Publishing, 198)
4th year) and "Latest Pigment Application Technology" (CMC Publishing, 19
1986).

The particle size of the pigment is 0.01 μm to 1 μm.
The thickness is preferably 0 μm, more preferably 0.05 μm to 1 μm, and most preferably 0.1 μm to 1 μm. The particle size is 0.
When the thickness is less than 01 μm, the stability of the dispersion when a dispersion such as a photosensitive layer coating solution is prepared may be deteriorated.
If it exceeds μm, the uniformity of the image forming layer may be deteriorated.

The method for dispersing the pigment can be appropriately selected from known dispersing techniques such as a general-purpose dispersing machine for ink production and toner production. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser,
Examples include a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. The details are described in “Latest Pigment Application Technology” (CMC Publishing, 1986).

The content of the dye or pigment is preferably 0.01 to 50% by mass, more preferably 0.1 to 10% by mass, based on the total solid content of the image forming layer. Is most preferably 0.5 to 10% by mass, and in the case of a pigment, 3.1 to 10% by mass is most preferred. If the content is less than 0.01% by mass, the sensitivity may be lowered. If the content is more than 50% by mass, the uniformity of the image forming layer may be reduced and the durability thereof may be deteriorated.

The dye or pigment may be added to the same layer as other components, or may be added to another layer provided. In the case of forming another layer, it is preferable to add it to a layer adjacent to a layer containing the component (C) described later. The dye or pigment and the alkali-soluble polymer compound are preferably contained in the same layer, but may be contained in different layers.

-(B) Alkali-soluble polymer compound- A usable alkali-soluble polymer compound (hereinafter referred to as "
It may be referred to as “component (B)”. As), an alkali water-soluble polymer compound having the following acidic groups (1) to (3) in the structure of the main chain and / or the side chain can be used. (1) phenol group (-Ar-OH) (2) sulfonamide group _{(-SO 2 NH-R) (} 3) substituted sulfonamide-based acid group [(hereinafter, referred to as "active imide group".) - SO ₂ NHCOR , -SO ₂ NHSO
During ₂ R, -CONHSO ₂ R] wherein (1) ~ (3), Ar represents a divalent aryl connecting group which may have a substituent, R may have a substituent Represents a hydrocarbon group. Hereinafter, specific examples will be shown, but the present invention is not limited thereto.

(1) Examples of the alkali-soluble polymer compound having a phenol group include a condensation polymer of phenol and formaldehyde, a condensation polymer of m-cresol and formaldehyde, and a condensation polymer of p-cresol and formaldehyde. , A condensation polymer of m- / p-mixed cresol and formaldehyde, phenol and cresol (m
Any of-, p- or m- / p- mixture may be used. ) And formaldehyde, and a novolak resin or a condensation polymer of pyrogallol and acetone. Further, a polymer compound obtained by polymerizing a monomer having a phenol group in a side chain can also be used.

As the high molecular compound having a phenolic hydroxyl group in the side chain, a polymerizable monomer comprising a low molecular compound having at least one unsaturated bond capable of polymerizing with the phenolic hydroxyl group may be homopolymerized, or the polymerizable monomer may be used. A polymer compound obtained by copolymerizing a monomer with another polymerizable monomer is exemplified. Examples of the monomer having a phenol group in the side chain include acrylamide, methacrylamide, acrylate, methacrylate or hydroxystyrene having a phenol group in the side chain.

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) ethyl acrylate, 2- (4-hydroxyphenyl) ethyl acrylate, 2- (2-hydro Shifeniru) ethyl methacrylate, 2- (3-hydroxyphenyl) ethyl methacrylate, 2- (4-hydroxyphenyl) ethyl methacrylate can be preferably exemplified.

The weight average molecular weight of the alkali-soluble polymer compound having a phenol group is 5.0 × 10 ²
~ 2.0 × 10 ⁵ has a number average molecular weight of 2.0
Those having a size of × 10 ^{2 to} 1.0 × 10 ⁵ are preferable in view of image forming properties.

The alkali-soluble polymer having a phenol group may be used alone or in combination of two or more. When combining,
As described in U.S. Pat. No. 4,123,279, an alkyl group having 3 to 8 carbon atoms as a substituent, such as a condensation polymer of t-butylphenol and formaldehyde or a condensation polymer of octylphenol and formaldehyde. May be used together with a condensation polymer of phenol and formaldehyde. These condensed polymers also preferably have a mass average molecular weight of 5.0 × 10 ^{2 to} 2.0 × 10 ⁵ and a number average molecular weight of 2.0 × 10 ^{2 to} 1.0 × 10 ⁵ .

(2) Examples of the alkali-soluble polymer compound having a sulfonamide group include, for example, a polymer having a compound having a sulfonamide group as a main monomer constituent unit, that is, a homopolymer or other monomer-containing unit. A copolymer obtained by copolymerizing a polymerizable monomer can be used. As a polymerizable monomer having a sulfonamide group, in one molecule, a sulfonamide group —SO ₂ —NH— having at least one hydrogen atom bonded to a nitrogen atom;
Examples of the monomer include a low-molecular compound having at least one polymerizable unsaturated bond. Among them, a low molecular weight 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. Examples of the low molecular compound include compounds represented by the following general formulas (a) to (e), but are not limited thereto.

[0085]

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In the formula, X ¹ and X ² each independently represent an oxygen atom or NR ⁷ . R ¹ and R ⁴ each independently represent a hydrogen atom or CH ₃ . R ² , R ⁵ , R ⁹ , R ¹² and R ¹⁶ are
Each independently having 1 to 1 carbon atoms which may have a substituent
2 represents an alkylene group, a cycloalkylene group, an arylene group or an aralkylene group. R ³ , R ⁷ and R ¹³ each independently represent a hydrogen atom or a carbon atom 1 which may have a substituent.
To 12 alkyl groups, cycloalkyl groups, aryl groups or aralkyl groups. R ⁶ and R ¹⁷ each independently represent an optionally substituted alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group. R ⁸ , R ¹⁰ and R ¹⁴ each independently represent a hydrogen atom or CH ₃ . R ¹¹ and R ¹⁵ each independently represent a single bond or an optionally substituted alkylene group having 1 to 12 carbon atoms, a cycloalkylene group, an arylene group or an aralkylene group. Y ¹ and Y ² each independently represent a single bond or CO.

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

(3) Examples of the alkali-soluble polymer compound having an active imide group include a polymer having a compound having an active imide group as a main monomer constituent unit. As a polymer having a compound having an active imide group as a main monomer structural unit, in one molecule,
An active imide group represented by the following formula and a monomer composed of a low-molecular compound having at least one polymerizable unsaturated bond are homopolymerized, or obtained by copolymerizing the monomer with another polymerizable monomer. High molecular compounds can be mentioned.

[0089]

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As such a compound, specifically,
N- (p-toluenesulfonyl) methacrylamide, N
-(P-toluenesulfonyl) acrylamide and the like can be preferably mentioned.

Further, in addition to the above, a polymer compound obtained by polymerizing two or more of the above-mentioned polymerizable monomers having a phenol group, a polymerizable monomer having a sulfonamide group, and a polymerizable monomer having an active imide group. ,
Alternatively, a polymer compound obtained by copolymerizing two or more polymerizable monomers with another polymerizable monomer is also preferably used.

A polymerizable monomer having a phenol group (M
In 1), a polymerizable monomer having a sulfonamide group (M
The mixing ratio (M1: M2 and / or M3; mass ratio) when copolymerizing the polymerizable monomer (M3) having 2) and / or an active imide group is from 50:50 to 5:95.
Is preferred, and 40:60 to 10:90 is more preferred.

The alkali-soluble polymer compound is a copolymer comprising a monomer structural unit having any one of the acidic groups (1) to (3) and a structural unit of another polymerizable monomer. In this case, the copolymer preferably contains at least 10 mol% of a monomer structural unit having any one selected from the acidic groups (1) to (3).
More preferably, the content is 0 mol% or more. When the content of the monomer constitutional unit is less than 10 mol%, sufficient alkali solubility cannot be obtained, and the development latitude may be narrow.

As a method for synthesizing the copolymer, a conventionally known graft copolymerization method, block copolymerization method, random copolymerization method and the like can be used.

The copolymer is copolymerized with a polymerizable monomer having a monomer having any one of the acidic groups (1) to (3) as a constituent unit. As other polymerizable monomers, for example, the following monomers (a) to (1) can be exemplified, but the present invention is not limited thereto.

(A) Acrylic esters and methacrylic esters having an aliphatic hydroxyl group, such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate. (B) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, glycidyl acrylate, N-dimethylaminoethyl Alkyl acrylates such as acrylates; (C) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl Alkyl methacrylates such as methacrylate.

(D) Acrylamide, methacrylamide, N-methylolacrylamide, N-ethylacrylamide, N-hexylmethacrylamide, N-cyclohexylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide , Acrylamide such as N-ethyl-N-phenylacrylamide, or methacrylamide. (E) 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. (F) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, and vinyl benzoate. (G) Styrene, α-methylstyrene, methylstyrene, chloromethylstyrene and the like and styrenes.

(H) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone and phenyl vinyl ketone. (I) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene. (J) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile and the like. (K) maleimide, N-acryloylacrylamide,
Unsaturated imides such as N-acetyl methacrylamide, N-propionyl methacrylamide and N- (p-chlorobenzoyl) methacrylamide; (L) unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride and itaconic acid;

Regarding the alkali water-soluble polymer compound, irrespective of a homopolymer or a copolymer, in terms of film strength,
Mass average molecular weight of 2,000 or more, number average molecular weight of 500
The above is preferable, and the weight average molecular weight is 5000 to 3
00000, the number average molecular weight is 800 to 250,000, and the degree of dispersion (mass average molecular weight / number average molecular weight) is 1.1 to
Ten are more preferred. Further, the alkali-soluble polymer compound is a phenol-formaldehyde resin,
In the case of a cresol-aldehyde resin or the like, those having a mass average molecular weight of 500 to 20,000 and a number average molecular weight of 200 to 10,000 are preferred.

The content of the alkali water-soluble polymer compound is preferably from 30 to 30% by mass of the total solid content of the image forming layer.
99 mass% is preferable, 40-95 mass% is more preferable, and 50-90 mass% is most preferable. The content is
If the amount is less than 30% by mass, the durability of the image forming layer may decrease. If the amount exceeds 99% by mass, the sensitivity and the durability may decrease. The polymer compound may be used alone or in combination of two or more.

-(C) a compound which is compatible with the alkali-soluble polymer compound to reduce the solubility of the alkali-soluble polymer compound in an aqueous alkali solution and reduces the solubility lowering effect by heating. The component (C) has good compatibility with the alkali-soluble polymer compound (B) due to the function of a hydrogen-bonding functional group present in the molecule, and can form a uniform coating solution for an image forming layer. In addition, it refers to a compound having a function of suppressing the alkali solubility of the alkali-soluble polymer compound through interaction with the alkali-soluble polymer compound (solubility suppressing action).

Further, the above-mentioned action of suppressing the solubility of the alkali-soluble polymer compound is eliminated by heating. However, when the infrared absorbing agent itself is a compound that can be decomposed by heating, sufficient energy for the decomposition can be obtained by the laser output or the like. If it is not given by various conditions such as irradiation time, the action of suppressing the solubility of the alkali-soluble polymer compound cannot be sufficiently reduced, and the sensitivity may be lowered. For this reason,
The thermal decomposition temperature of the component (C) is preferably 150 ° C. or higher.

As the component (C), for example, in consideration of the interaction with the (B) alkali-soluble polymer compound, for example,
It can be appropriately selected from compounds that can interact with the alkali-soluble polymer compound, such as a sulfone compound, an ammonium salt, a phosphonium salt, and an amide compound.
In particular, for example, when a novolak resin is used alone as the component (B), the “(A + C) component” described below is used.
Is preferable, and the cyanine dye A exemplified below is more preferable. The (A + C) component will be described later.

The mixing ratio (C / B) of the component (C) and the alkali-soluble polymer compound (B) is generally 1 /
99 to 25/75 is preferred. The mixing ratio is 1/99
When the amount is less than the above, that is, when the amount of the component (C) is too small, the interaction with the alkali-soluble polymer compound becomes insufficient, so that the alkali-solubility cannot be reduced and the image cannot be formed well. If the ratio exceeds / 75, that is, if the component (C) is too large, the interaction becomes excessive,
Sensitivity may be significantly reduced.

-Component (A + C)-In place of the components (A) and (C), a compound having both properties ((A + C) component) can be used. The component (A + C) has a property of absorbing light to generate heat (that is, the characteristic of the component (A)),
It is a basic dye which has an absorption range in the wavelength region of 00 to 1200 nm and is further compatible with an alkali-soluble polymer compound. The component (A + C) has, in its molecule, a group that interacts with an alkali-soluble polymer compound such as an ammonium group or an iminium group (that is, the property of the component (C)). And its alkali solubility can be suppressed. Examples of the component (A + C) include compounds represented by the following general formula (Z).

[0106]

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In the general formula (Z), R ^{21 to} R ²⁴ each independently represent a hydrogen atom or an optionally substituted alkyl, alkenyl, alkoxy or cycloalkyl group having 1 to 12 carbon atoms. Represents an alkyl group or an aryl group, and R ²¹ and R ²² , and R ²³ and R ²⁴ may be bonded to each other to form a ring structure. R ^{21 to} R ²⁴ include, for example, a hydrogen atom,
Examples thereof include a methyl group, an ethyl group, a phenyl group, a dodecyl group, a naphthyl group, a vinyl group, an allyl group, and a cyclohexyl group, and these groups may further have a substituent. Here, examples of the substituent include a halogen atom,
Carbonyl group, nitro group, nitrile group, sulfonyl group,
Examples thereof include a carboxyl group, a carboxylic acid ester, and a sulfonic acid ester.

In the formula, R ^{25 to} R ³⁰ each independently represent an alkyl group having 1 to 12 carbon atoms which may have a substituent, and R ^{25 to} R ³⁰ include, for example, a methyl group, Examples include an ethyl group, a phenyl group, a dodecyl group, a naphthyl group, a vinyl group, an allyl group, and a cyclohexyl group, and these groups may further have a substituent. Here, examples of the substituent include a halogen atom, a carbonyl group,
Examples include a nitro group, a nitrile group, a sulfonyl group, a carboxyl group, a carboxylic acid ester, and a sulfonic acid ester.

[0109] In the formula, R ³¹ to R ³³ each independently represents a hydrogen atom, a halogen atom, or an optionally substituted alkyl group having 1 to 8 carbon atoms, wherein R ^32, said R ³¹ or may be bonded to R ³³ to form a ring structure, m> 2, the general may be bonded multiple R ³² together form a ring structure. Examples of R ^{31 to} R ³³ include a chlorine atom, a cyclohexyl group, and a cyclopentyl ring and a cyclohexyl ring formed by bonding R ^{32 to} each other, and these groups may further have a substituent. . Here, examples of the substituent include a halogen atom, a carbonyl group, a nitro group, a nitrile group, a sulfonyl group, a carboxyl group,
Carboxylic acid esters, sulfonic acid esters and the like can be mentioned. M represents an integer of 1 to 8, and preferably 1 to 3.

[0110] In the formula, R ³⁴ to R ³⁵ each independently represent a hydrogen atom, a halogen atom, or an optionally substituted alkyl group having 1 to 8 carbon atoms, wherein R ³⁴ is a R ³⁵ A bond may form a ring structure, and when m> 2, a plurality of R ³⁴ may bond with each other to form a ring structure. Examples of R ^{34 to} R ³⁵ include a chlorine atom, a cyclohexyl group, a cyclopentyl ring and a cyclohexyl ring formed by bonding R ^{34 to} each other, and these groups may further have a substituent. . Here, examples of the substituent include a halogen atom, a carbonyl group, a nitro group, a nitrile group, a sulfonyl group, a carboxyl group, a carboxylic acid ester, and a sulfonic acid ester. Also, m
Represents an integer of 1 to 8, and among them, 1 to 3 is preferable.

In the formula, X ⁻ represents an anion.
Perchloric acid, tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-O-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2,4,4 6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-
Chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid and para Toluenesulfonic acid and the like can be mentioned. Among them, alkyl aromatic sulfonic acids such as hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, and 2,5-dimethylbenzenesulfonic acid are preferable.

The compound represented by the general formula (Z) is a compound generally called a cyanine dye, and specifically, the following compounds are suitably used, but not limited thereto.

[0113]

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When the component (A + C) having both of these characteristics is used instead of the component (A) and the component (C), the usage ratio of the component (A + C) to the component (B) [ (A + C) / (B)] is 1/99 to 30
/ 70 is preferred, and 1/99 to 25/75 is more preferred.

The following are the components constituting the recording layer of the negative type lithographic printing plate. — (D) Compound that Generates Acid by Heat— When the image forming material is a negative type, a compound that generates an acid when heated (hereinafter, referred to as “acid generator”) is used in combination. The acid generator increases the number of compounds that decompose when heated to 100 ° C. or more to generate an acid. As the generated acid,
It is preferably a strong acid having a pKa of 2 or less, such as sulfonic acid and hydrochloric acid. Examples of the acid generator include Japanese Patent Application No. 11-66.
No. 733.

The amount of the acid generator is preferably 0.01 to 50% by mass, more preferably 0.1 to 40% by mass, and more preferably 0.5 to 30% by mass based on the total solid content of the image forming layer. % Is most preferred.

-(E) Crosslinking Agent Crosslinked by Acid-When the lithographic printing plate precursor is of a negative type, a crosslinking agent crosslinked by an acid (hereinafter sometimes simply referred to as "crosslinking agent") is used in combination. Examples of the crosslinking agent include the following. (I) an aromatic compound substituted with an alkoxymethyl group or a hydroxymethyl group (ii) a compound having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group (iii) an epoxy compound Nos. 10-53788 and phenol derivatives.

The amount of the crosslinking agent to be added is preferably from 5 to 80% by mass based on the total mass of the solid content of the image forming layer.
-75 mass% is more preferable, and 20-70 mass% is most preferable. When the phenol derivative is used as a cross-linking agent, the amount of the phenol derivative to be added is preferably 5 to 70% by mass, more preferably 10 to 50% by mass, based on the total solid content of the image forming material. Details of the above various compounds are described in Japanese Patent Application No. 11-66733.

-Other Components- Various additives can be further added to the image forming layer of the lithographic printing plate precursor suitable for applying the alkali developing solution, if necessary. For example, known additives such as cyclic acid anhydrides, phenols, organic acids, and sulfonyl compounds can be used in combination for the purpose of improving sensitivity. The amount of the other cyclic acid anhydride, phenol, organic acid or sulfonyl compound to be added is preferably 0.05 to 20% by mass, more preferably 0.1 to 15% by mass, based on the total solid content of the image forming layer. % Is more preferable, and 0.1 to 10% by mass is most preferable.

For the purpose of expanding the stability of processability under development conditions, nonionic surfactants described in JP-A Nos. 62-251740 and 3-208514, and JP-A Nos. 59-121044. No., JP-A-4-1314
An amphoteric surfactant described in JP-A No. 9 and the like can be added. The amount of the nonionic surfactant or amphoteric surfactant used is 0.0 with respect to the total solid content of the image forming layer.
It is preferably from 5 to 15% by mass, more preferably 0.1% by mass.

After heating by exposure, the image forming layer
A dye or pigment as a printing-out agent or an image coloring agent for immediately obtaining a visible image can be added. Examples of the printing-out agent include a combination of a compound that generates an acid by heating upon exposure and an organic dye that can form a salt. Specifically, a combination of o-naphthoquinonediazide-4-sulfonic acid halogenide and a salt-forming organic dye described in JP-A-50-36209 and JP-A-53-8128, 53-36223, JP-A-54
-74728, JP-A-60-3626, JP-A-61
And combinations of a trihalomethyl compound and a salt-forming organic dye described in JP-A-143748, JP-A-61-151644 and JP-A-63-58440. The trihalomethyl compound includes an oxazole-based compound and a triazine-based compound, all of which have excellent stability over time and give clear print-out images. As the image colorant, for example, other dyes can be used in addition to the salt-forming organic dye, and for example, an oil-soluble dye and a basic dye are preferable.

More specifically, oil yellow # 101, oil yellow # 103, oil pink # 312, oil green BG, oil blue BOS, oil blue # 6
03, Oil Black BY, Oil Black BS, Oil Black T-505 (all manufactured by Orient Chemical Industries, Ltd.), Victoria Pure Blue, Crystal Violet (CI. 42555), Methyl Violet (CI. 42535) , Ethyl violet, rhodamine B (CI. 145170B), malachite green (CI. 42000), methylene blue (CI.
52015) and the like. In addition, Japanese Unexamined Patent Publication
The dyes described in JP-A-2-293247 are particularly preferred. The amount of the various dyes to be added is preferably 0.01 to 10% by mass, and more preferably 0.1 to 10% by mass based on the total solid content of the image forming layer.
~ 3 mass% is more preferred.

A plasticizer may be added, if necessary, for the purpose of imparting flexibility or the like to the coating film. As the plasticizer, for example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic Examples include oligomers and polymers of acid or methacrylic acid.

Further, the following various additives can be added as required. For example, onium salts, o-quinonediazide compounds, aromatic sulfone compounds, aromatic sulfonic acid ester compounds, and other compounds that are thermally decomposable and substantially reduce the solubility of an alkali water-soluble polymer compound in an undecomposed state. Can be used together. The addition of the compound is preferred from the viewpoint of improving the ability to inhibit the dissolution of the image area in the developer. The amount of the onium salt, o-quinonediazide compound, aromatic sulfonic acid ester or the like to be added is preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass, based on the total solid content of the image forming layer. More preferably, 0.5 to 20
% By weight is most preferred.

The support in the photosensitive lithographic printing plate will be described below. The photosensitive layer is coated on a support which is a dimensionally stable plate-like material to form a photosensitive lithographic printing plate. As such a support, paper, paper laminated with plastics (for example, polyethylene, polypropylene, polystyrene, etc.), for example, a metal plate of aluminum (including aluminum alloy), zinc, iron, copper, etc., for example, cellulose diacetate , Cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene,
Plastic films such as polystyrene, polypropylene, polycarbonate, and polyvinyl acetal, and paper or plastic films and glass plates on which the above metals are laminated or deposited are used.

Basically, an aluminum plate is used as a support. Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of the foreign element in the alloy is at most 10% by mass or less. The preferred aluminum is pure aluminum, but completely pure aluminum is difficult to produce due to refining techniques and may therefore contain slightly foreign elements. The composition of the aluminum plate is not specified, and a conventionally known and used material can be appropriately used. The thickness of the aluminum plate is about 0.1 mm to 0.6 mm.

The aluminum plate is roughened in order to improve the water retention of the surface and the adhesion to the photosensitive layer. Prior to the roughening, if necessary, for example, a surfactant or organic solvent for removing the rolling oil on the surface is used. A film removal treatment using a solvent or an alkaline aqueous solution is performed. The photosensitive lithographic printing plate can be used on only one side, but when preparing a photosensitive lithographic printing plate that can be used on both sides by the same processing, the same processing may be performed on both sides. First, the surface of an aluminum plate is subjected to a surface roughening treatment, which includes a method of mechanically roughening the surface, a method of electrochemically dissolving and roughening the surface, and a method of selectively dissolving the surface chemically. There is a way.
As a mechanical method, a known method called a ball polishing method, a brush polishing method, a blast polishing method, a buff polishing method, or the like can be used. Further, as an electrochemical surface roughening method, there is a method of performing an alternating or direct current in a 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 aluminum plate thus roughened is subjected to an alkali etching treatment and a neutralization treatment, if necessary, and then subjected to an anodic oxidation treatment to increase the water retention and abrasion resistance of the surface. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, any electrolyte that forms a porous oxide film can be used, and generally, 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 the electrolyte. Anodizing treatment conditions vary depending on the electrolyte to be used, and thus cannot be specified unconditionally. In general, the concentration of the electrolyte is 1 to 80% by mass, and the solution temperature is 5 to 5.
70 ° C., current density 5 to 60 A / dm ² , voltage 1 to 100
V, the electrolysis time is suitably in the range of 10 seconds to 5 minutes.
The amount of the anodized film is suitably 1.0 g / m ² or more, but more preferably in the range of 2.0 to 6.0 g / m ^2. When the anodic oxide film is less than 1.0 g / m ² , the printing durability is insufficient, and the non-image area of the lithographic printing plate is easily damaged, and the ink adheres to the damaged area during printing, so-called “ "Scratch dirt" easily occurs.

[Hydrophilic treatment] As a treatment which is not essential but may be used for the support which has been subjected to the above treatment, there is a conventionally known hydrophilization treatment. Examples of such a hydrophilic treatment include U.S. Pat. Nos. 2,714,066 and 3,1.
No. 81,461, No. 3,280,734, No. 3,90
There is an alkali metal silicate (for example, sodium silicate aqueous solution) method as disclosed in US Pat. No. 2,734. In this method, the support is immersed or electrolytically treated in an aqueous solution of sodium silicate. Or, Tokubiko Sho36
Potassium Fluoride Zirconate as disclosed in U.S. Pat.
For example, a method of treating with polyvinyl phosphonic acid as disclosed in JP-A-53,461 and JP-A-4,689,272 is used. Among these, a particularly preferred hydrophilization treatment is a silicate treatment. The silicate treatment will be described below.

(Silica treatment) The alkali metal silicate was applied to the anodic oxide film on the aluminum plate that had been treated as described above.
0.001 to 30% by mass, preferably 0.01 to 10% by mass
In an aqueous solution having a pH of 10 to 13 at 25 ° C,
For example, immersion is performed at 15 to 80 ° C. for 0.5 to 120 seconds. If the pH of the alkali metal silicate aqueous solution is lower than 10, the solution gels, and if it is higher than 13.0, the oxide film is dissolved. As the alkali metal silicate, sodium silicate, potassium silicate, lithium silicate and the like are used. Hydroxides used to increase the pH of the aqueous alkali metal silicate solution include sodium hydroxide, potassium hydroxide and lithium hydroxide. In addition, an alkaline earth metal salt or a Group IVB metal salt may be added to the above-mentioned processing solution. Examples of the alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and water-soluble salts such as sulfate, hydrochloride, phosphate, acetate, oxalate, and borate. No. Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, potassium titanium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, zirconium tetrachloride, and the like. Can be. Alkaline earth metal salts or Group IVB metal salts can be used alone or in combination of two or more. The preferred range of these metal salts is 0.01 to 10% by mass, and the more preferred range is 0.05 to 5.0% by mass. Since the silicate treatment further improves the hydrophilicity on the aluminum plate surface, the ink hardly adheres to the non-image area during printing, and the stain performance is improved.

[Organic undercoat layer] The support is provided with an organic undercoat layer if necessary before coating the photosensitive layer. The organic compound used in such an organic undercoat layer is disclosed in
Compounds described in JP-A-82637, JP-A-8-225335, JP-A-9-89646, JP-A-9-106068 and JP-A-9-127232 are preferably used.

[Backcoat] On the back surface of the support, a backcoat is provided if necessary. Examples of the back coat include a coating comprising a metal oxide obtained by hydrolyzing and polycondensing an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174. Layers are preferably used. Among these coating layers, Si (OCH ₃ ) ₄ , Si
(OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , Si (OC
Alkoxy compounds of silicon such as ₄ H ₉ ) ₄ are inexpensive and readily available, and a coating layer of a metal oxide provided therefrom is particularly preferred because of its excellent development resistance.

[0133]

[Exposure, development and post-processing] UV / visible light-sensitive lithographic printing plates are exposed through transparent originals, for example, with a mercury lamp, metal halide lamp, xenon lamp, chemical lamp, tungsten lamp, carbon arc lamp, etc. After being developed by the developing method of the invention, it is optionally subjected to washing with water, treatment with a rinsing solution, desensitization treatment, and the like. The infrared-sensitive lithographic printing plate is exposed by a plate setter equipped with a laser having an emission wavelength in the near infrared to infrared region. As such a laser, a solid-state laser or a semiconductor laser that emits infrared light having a wavelength of 760 nm to 1200 nm is preferable. In the present invention,
Development processing may be performed immediately after laser irradiation,
Heat treatment is preferably performed between the laser irradiation step and the developing step. The heat treatment is preferably performed in a range of 80 ° C. to 150 ° C. for 10 seconds to 5 minutes. By this heat treatment, the laser energy required for recording at the time of laser irradiation can be reduced. After performing a heat treatment as needed, it is subjected to a development treatment according to the development treatment method of the present invention, and is then optionally subjected to a washing with water, a treatment with a rinsing solution, a desensitization treatment and the like. Further, the photopolymerizable photosensitive lithographic printing plate is subjected to a scanning treatment with an argon laser and a YAG laser, and then, if necessary, subjected to a heating treatment, and is developed by the developing treatment method of the present invention, and then optionally washed with water and rinsed. A treatment with a liquid, a desensitization treatment, and the like are performed.

[0134]

According to the method of the present invention, the development processing can be carried out while maintaining the developing activity of the developer constant regardless of the degree of the development processing. More specifically, a good printed matter can be provided without causing a residual film in a non-image part or a defect in an image part in a lithographic printing plate.

[0135]

The present invention will be described below in detail with reference to examples.
However, the present invention is not limited to these. In addition,
All “%” in the examples represent “% by mass”. <Preparation of a lithographic printing plate precursor> 0.3 mm thick aluminum
Wash the plate (material 1050) with trichlorethylene and remove
After grease, nylon brush and 400 mesh pumice-
Using a water suspension, grain this surface and wash it well with water
did. After washing, the aluminum plate was washed with 45% water at 45 ° C.
Etch for 9 seconds in an aqueous solution of sodium oxide
After washing with water, immerse in a 20% nitric acid aqueous solution for 20 seconds.
Pickled and washed again with water. Etching of the grained surface at this time
Approximately 3 g / m ^TwoMet.

Next, the aluminum plate was charged with 7% sulfuric acid.
As a lysate, current density 15A / dm ^Two3g with direct current
/ M^TwoAfter providing an anodic oxide film, the substrate was washed with water and dried. This
This was treated with a 2.5% aqueous solution of sodium silicate at 30 ° C for 10 seconds.
And apply the following undercoat layer coating solution,
The support was obtained by drying for 5 seconds. Drying of the undercoat layer after drying
Application amount is 15mg / m^TwoMet.

<Coating solution for undercoat layer> The following copolymer P (molecular weight: 28,000) 0.3 g methanol 100 g water 1 g

[0138]

<Synthesis of Specific Copolymer> Synthesis Example (Specific Copolymer 1) 31.0 g (0.36 mol) of methacrylic acid was placed in a 500 ml three-necked flask equipped with a stirrer, a condenser and a dropping funnel.
39.1 g (0.36 mol) of ethyl chloroformate and 200 ml of acetonitrile were added, and the mixture was stirred while cooling in an ice water bath. To this mixture was added triethylamine 36.4.
g (0.36 mol) was dropped by a dropping funnel over about 1 hour. After dropping, remove the ice-water bath and allow
The mixture was stirred for 0 minutes. To the reaction mixture was added 51.7 g (0.30 mol) of p-aminobenzenesulfonamide, and the mixture was stirred for 1 hour while warming to 70 ° C. in an oil bath. After completion of the reaction, the mixture was added to 1 liter of water while stirring the water, and the resulting mixture was stirred for 30 minutes. The mixture was filtered to remove a precipitate, which was slurried with 500 ml of water, and then the slurry was filtered.
By drying the obtained solid, a white solid of N- (p-aminosulfonylphenyl) methacrylamide was obtained (yield 46.9 g).

Next, 4.61 g of N- (p-aminosulfonylphenyl) methacrylamide, (0.0192 mol) and 2.94 g of ethyl methacrylate were placed in a 20 ml three-necked flask equipped with a stirrer, a condenser and a dropping funnel. 0.0258 mol), 0.80 g (0.015 mol) of acrylonitrile
And 20 g of N, N-dimethylacetamide, and the mixture was stirred while being heated to 65 ° C. in a hot water bath. 0.15 g of "V-65" (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the mixture, and the mixture was stirred for 2 hours under a nitrogen stream while maintaining the temperature at 65 ° C. To this reaction mixture, 4.61 g of N- (p-aminosulfonylphenyl) methacrylamide, 2.94 g of ethyl methacrylate, 0.80 g of acrylonitrile, N, N-
A mixture of dimethylacetamide and 0.15 g of “V-65” was added dropwise by a dropping funnel over 2 hours. After the addition was completed, the resulting mixture was further stirred at 65 ° C. for 2 hours. After completion of the reaction, methanol (40 g) was added to the mixture, and the mixture was cooled. The obtained mixture was poured into 2 liters of water while stirring the water. The mixture was stirred for 30 minutes, and the precipitate was removed by filtration and dried. Gave 15 g of a white solid. The weight average molecular weight (polystyrene standard) of this specific copolymer was measured to be 53,000 by gel permeation chromatography.

The following image forming layer coating solution was applied on the obtained support so that the dry coating amount was 1.8 g / m ² , to obtain a positive type lithographic printing original plate. <Coating liquid for image forming layer> Specific copolymer 1 [component (B)] 0.4 g m, p-cresol novolak [component (B)] 0.6 g (m / p ratio = 6/4, weight) Average molecular weight 8000, contains 0.5% of unreacted cresol) Cyanine dye A [(A + C) component] 0.1 g Phthalic anhydride [(D) component] 0.05 g p-Toluenesulfonic acid 0.002 g Ethyl violet 0. 02g (counter ion: 6-hydroxy-β-naphthalenesulfonic acid) Esterified product of naphthoquinone 1,2-diazide-5-sulfonyl chloride and pyrogallol-acetone resin 0.01 g Fluorine surfactant 0.05 g (trade name: Megafac F-177, manufactured by Dainippon Ink and Chemicals, Inc.) Methyl ethyl ketone 8 g 1-methoxy-2-propanol 4 g

[0142]

Example 1 Preparation of alkaline developing solution containing non-reducing sugar D-sorbite potassium salt 50 comprising D-sorbite / potassium oxide K ₂ O in combination of non-reducing sugar and base
% Aqueous solution (1 liter), 1.0% of polyethylene glycol 100 was added, and KOH was further added to adjust the pH to 13.0.
Was adjusted to a developing solution. A stock solution for developing replenisher was prepared by adding 50% of polyethylene glycol 1000 to 1 liter of a 30.0% aqueous solution of potassium D-sorbite and further adjusting the pH to 14.0 by adding KOH.

Output 5 to the lithographic printing original plate obtained above
00 mW, wavelength 830 nm, beam diameter 17 μm (1 /
e^Two) Main scanning speed of 5m / sec using semiconductor laser
And kept at 25 ° C. This lithographic printing plate is
Automatic developing machine PS900NP filled with the above developing solution
(Developed by Fuji Photo Film Co., Ltd.). [Replenishment conditions] (1) Depending on the plate processing amount,
Undiluted solution: 30 m of diluted solution obtained by diluting 1: 2 (volume) with water
l / m^TwoReplenish with. (2) Depending on the time, the above-mentioned stock solution of the developing replenisher was replaced with stock solution: water =
100 ml / hour of diluted solution obtained by diluting 1: 5 (volume)
Replenish with. Average 10m / day^TwoUnder processing conditions, 1
m^Two, 50m^Two, 100m^Two, 200m ^Two, 400m^Two, 6
00m^Two, 800m^Two, 1000m^TwoLithographic printing plate during processing
I got

<Evaluation of Balance of Image / Non-Image Area> (Evaluation of Developability of Non-Image Area)
m ² , 50 m ² , 100 m ² , 200 m ² , 400 m ² , 6
The lithographic printing plate after the processing of 00 m ² , 800 m ² , and 1000 m ^{2 was} visually observed for “the presence or absence of a residual film in a non-image portion” according to the following criteria, and was subjected to a sensory evaluation. The printed matter was also evaluated. Table 1 shows the results. -Criterion- A: sufficiently developed, no residual image-forming layer on non-image area observed. There were no stains on the prints. Δ: The image forming layer slightly remained on the non-image portion, but there was no stain on the printed matter. C: Defective development was observed, and the image forming layer remained in the non-image area. The printed matter was also stained.

(Evaluation of film thinning in image area) 1 m ² , 50 m ² , 100 m ² , 200 m ² , 400 obtained as described above
according to the following criteria to "defect image" of the planographic printing plate in ^{m 2, 600m 2, 800m 2} , at 1000 m ² treatment, it was visually observed, the sensory evaluation was conducted. The printed matter was also evaluated. Table 1 shows the results. -Criteria- A: No defect was observed in the image area. There was no whitening in the image area on the printed matter. Δ: Image density slightly decreased, and some defects were observed. There was no whitening in the image area on the printed matter. X: The density of the image portion was significantly reduced, and there were defective portions in the image portion. White spots occurred on the image area on the printed matter.

[0146]

[Example 2] Under the condition of processing 100 m ² on average per day,
1m ² , 50m ² , 100m ² , 200m ² , 400m ² ,
Except to obtain 600m ^2, 800m ^2, 1000m ² planographic printing plate during the treatment, carried out in the same manner as in plate-making process as in Example 1, was evaluated in the same manner as in Example 1. Table 1 shows the results.

[0147]

Comparative Example 1 A plate-making process was performed in the same manner as in Example 1 except that the following replenishment conditions were employed using the same stock solution of the developing replenisher, and the same evaluation as in Example 1 was performed. . [Replenishment conditions] (1) 40 ml of a diluent obtained by diluting a stock solution of development replenisher to a stock solution: water = 1: 3 (volume) according to the plate processing amount
/ M ² . (2) Depending on the time, a stock solution of the developing replenisher was prepared by adding stock solution: water = 1:
The diluted solution obtained by diluting to 3 (volume) is replenished at 60 ml / hour. Table 1 shows the results.

[0148]

Comparative Example 2 A plate making process was carried out in the same manner as in Example 2, except that the following replenishment conditions were employed using the same undiluted developing solution as in Example 1, and the same evaluation as in Example 2 was carried out. . [Replenishment conditions] (1) 40 ml of a diluent obtained by diluting a stock solution of development replenisher to a stock solution: water = 1: 3 (volume) according to the plate processing amount
/ M ² . (2) Depending on the time, a stock solution of the developing replenisher was prepared by adding stock solution: water = 1:
The diluted solution obtained by diluting to 3 (volume) is replenished at 60 ml / hour. Table 1 shows the results.

[0149]

[Table 1]

Continuation of the front page (72) Inventor Hiroyuki Sasayama 4000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture Fujisha Shin Film Co., Ltd. F-term (reference) 2H096 AA07 GA08 GA09 GA13

Claims (2)

[Claims] 1. A developing replenisher having a different alkali concentration between a developing replenisher which compensates for a decrease in the activity of a developer due to processing of a photosensitive lithographic printing plate and a developing replenisher which compensates for a decrease in the activity of the developer over time. A method for developing a photosensitive lithographic printing plate, characterized in that the activity of the developing solution is kept constant by replenishing with a lithographic printing plate. 2. The developing method according to claim 1, wherein
A concentrated lithographic printing plate comprising replenishing a developing replenisher having the same concentration of a replenisher for replenishing the decrease in activity due to processing and the decrease in activity over time, but having a different dilution ratio. Development processing method.