JP3437367B2 - Plate surface treatment liquid for lithographic printing plates - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention
Neutralizing solution, a surface treatment solution for lithographic printing plates used as
(Stabilizing solution) and etch solution. 2. Description of the Related Art High sensitivity and spectral sensitization
Some printing plates using silver halide emulsions
Has been put into practical use. Silver image will be accepted for ink
US Patent for Offset Printing Plate
No. 3721559, No. 3490905, Shoko 4
No. 8-30562, U.S. Pat. No. 3,385,701, U.S. Pat.
No. 3814603, JP-B-44-27242, JP-A-Showa
No. 53-21602, U.S. Pat.
Nos. 3,763,323 and 3,099,209;
No. 3-9603. [0003] These are the most common methods for producing printing plates.
Although it is roughly classified into several types,
They are common in reasoning. Lithographic printing
The plate is made of a hydrophilic and water-based image area that accepts lipophilic ink.
And a non-image portion that receives Therefore, usually
Lithographic printing supplies both water and ink to the plate,
Selectively receive colored ink and non-image areas receive water.
And transfer the ink on the object to a substrate such as paper.
It is done by letting [0004] In order to obtain a good printed matter, an image portion and
The difference between the lipophilicity and hydrophilicity of the surface of the non-image area is sufficiently large
Is required. [0005] The printing plate using the silver halide emulsion described above
The plate making method is simple, reliable and quick, and must be automated
High sensitivity, high resolution, and high image reproducibility
Organic colloid such as diazo photosensitive material
Compared to the printing plate (PS plate) etc.
Sufficient difference in lipophilicity and hydrophilicity between the image part and non-image part
It was not big. In order to overcome such a disadvantage, Japanese Patent Publication No. Sho 48
No. 29723, JP-A-58-127728, etc.
Water-insoluble compounds having a rucapto group or a thione group
Before printing, it acts on the silver image to improve ink acceptance.
Are shown. That is, the mercapto group of the compound
Or the thione group is adsorbed on the image silver and the hydrophobic part of the compound
Covers the silver image and the lipophilicity of the image area and the non-image area
It is believed that the difference in aqueous is relatively large. Generally, DT which makes image silver ink-receptive
R lithographic printing materials are used for image exposure when preparing printing plates.
After, to develop at high pH (pH 13 or more), after development,
It is necessary to neutralize and stabilize the surface of lithographic printing plates.
Neutral solution of weak to acidic (pH 5 to 7) is used
You. After the neutralization is stabilized, the silver image area is
Has a mercapto group or a thione group to make
Treated with a sensitizing solution (etch solution) containing
Was. Compounds having a mercapto group or a thione group
The substance is generally dissolved in an alkaline solution or an organic solvent
However, since it does not dissolve in neutral or weakly acidic aqueous solution,
Was dissolved in an organic solvent and added. In recent years, image silver has been used as ink acceptability.
Engraving plates on printing presses as lithographic printing plates become larger
It is possible to etch with a sensitizing liquid (etch liquid) before printing.
It is difficult to do it industrially, and it can be used for neutralizing solution after development processing.
It has a sensitizing function and saves the above sensitizing solution (etch solution).
Abbreviation or improvement of sensitization power by combined use with etchant
Attempts have been made. However, mercapto groups or thiones
Or etchant having a pH of about 5 to 7
Ethyl alcohol conventionally used to dissolve
Use of organic solvents such as alcohol and isopropyl alcohol
It is not preferable because of environmental and safety issues. Especially neutralization
In liquids, the organic solvent evaporates in the processing equipment and
Compounds having thio groups or thione groups are likely to precipitate
There is a problem. In order to solve the above problem, Japanese Patent Laid-Open Publication No.
No. 9982 and No. 7-248630 describe amine compounds.
Using a mercapto group or a thione group in the plate surface treatment solution.
Discloses a method of dissolving and containing a compound having
You. However, mercapto groups are not
Or a plate surface treatment solution in which a compound having a thione group is dissolved,
Dissolution stability of compounds with mercapto or thione groups
A new problem has arisen due to the poor nature. Sand
That is, during storage of the processing solution, especially when stored at a low temperature in winter.
Compound with mercapto group or thione group
Problem arises. This precipitate is
The trouble was that it did not easily redissolve. The object of the present invention is to provide an image
Plate surface treatment of lithographic printing plates using silver as ink acceptability
Liquid, such as neutralizing solution (stabilizing solution) or etch solution
No mercapto group or thione group
Is to stably contain a compound having
Has a mercapto group or a thione group during warm storage
Prevents the precipitation of the compound, and stabilizes the dissolved state of the compound.
By maintaining high ink receptivity stably.
Is Rukoto. [0015] The above objects of the present invention are as follows.
Plate surface of lithographic printing plate using image silver as ink acceptability
In the processing solution, water having a mercapto group or a thione group
At least one insoluble compound and
Achieved by containing compounds. Embedded image A is a vinyl monomer having a carboxy group
-, B is a copolymerizable ethylenically unsaturated monomer, M is
Cations such as hydrogen, alkali metal and ammonium ion
Represents l is 30 to 90 mol%, m is 10 to 50 mol
%, N is 0 to 50 mol%. By containing the compound shown in Chemical formula 2,
The ink in the processing solution without impairing the ink acceptability of the image area.
Dissolution state of compound having mercapto group or thione group
Can be kept stable, increasing the stability of the plate surface treatment solution,
Lithographic printing plates can have stable ink receptivity.
Came. The compound of formula 2 used in the present invention is shown below.
Although described, it is not limited to these. Examples of the monomer A in the above chemical formula 2 include:
Crylic acid, methacrylic acid, sorbic acid, maleic acid,
Malic acid, itaconic acid, citraconic acid (maleic anhydride
Acids, acid anhydrides such as itaconic anhydride, or
May be substituted) and the like. They are alkaline
It may be in the form of a salt with a metal atom or the like. Preferably anhydrous
Maleic acid. Examples of the monomer B in the above chemical formula 2 include
Chill, ethyl, propyl, isopropyl, n-butyl,
Acrylic acid or methacrylic acid such as 2-ethylhexyl
Alkyl esters, acrylonitrile, methacryloyl
Acrylic acid such as nitrile, acrylamide or meta
Derivatives of crylic acid, N-vinylpyrrole, N-vinylcaprol
N-vinylation of rubazole, N-vinylpyrrolidone, etc.
Compounds, etc., are used.
As the union, it is preferable that the monomer B is not contained.
Good. As a preferred example of the compound shown in Chemical formula 2,
Is the sulfonation of copolymers of styrene and maleic anhydride
Styrene / maleic anhydride ratio of 1/1 to 3/1
Having a molecular weight of 20,000 or less, preferably
1000 to 5000. This compound is known
And can be obtained as a commercial product. The content of these compounds is about 0.1%
A concentration range of about 20% (by weight) is appropriate. The method described later
About compounds containing a rucapto or thione group.
A combination of 1 to 100 times (weight ratio) is preferred. The mercapto group or thiol group used in the present invention
Compounds having an on group are described, for example, in JP-B-48-297.
No. 23, JP-A-58-127928 and the like.
You. In particular, a parent such as an alkyl group, an aryl group, and an alkenyl group
Those having an oily group are preferred. Having a mercapto group or a thione group of the present invention
As a typical example of the compound represented by the following general formula:
And the like. Embedded image (Wherein R is a hydrogen atom, having 12 or less carbon atoms,
Preferably 3 to 12 alkyl groups, aryl groups, alk
Z is a 5- to 6-membered ring together with N and C in the formula
Shows the remaining groups of bonds needed to form. Specific examples of the 5- or 6-membered ring include
Midazole, imidazoline, thiazole, thiazoline,
Oxazole, oxazoline, pyrazoline, triazoline
, Thiadiazole, oxadiazole, tetrazo
Pyridine, pyrimidine, pyridazine, pyrazine, g
Liadin, etc., and these rings are formed by condensation of two or more
And may be condensed with a benzene ring or naphthalene ring.
They may be combined. Specific examples of such compounds include 2-merca
Pt-4-phenylimidazole, 2-mercapto-1
-Benzylimidazole, 2-mercapto-benzimi
Dazol, 1-ethyl-2-mercapto-benzimida
Zol, 2-mercapto-1-butyl-benzimidazo
Ole, 1,3-diethyl-benzimidazoline-2-ti
On, 1,3-dibenzyl-imidazolidin-2-thio
2,2'-dimercapto-1,1'-decamethylene
-Diimidazoline, 2-mercapto-4-phenylthia
Sol, 2-mercapto-benzothiazole, 2-mer
Captonaphthothiazole, 3-ethyl-benzothiazoli
2-thione, 3-dodecyl-benzothiazoline-2
-Thione, 2-mercapto-4,5-diphenyloxa
Sol, 2-mercaptobenzoxazole, 3-pen
Tyl-benzoxazoline-2-thione, 1-phenyl
-3-Methylpyrazoline-5-thione, 3-mercapto
-4-Allyl-5-pentadecyl-1,2,4-tria
Sol, 3-mercapto-5-nonyl-1,2,4-to
Riazol, 3-mercapto-4-acetamide-5-he
Butyl-1,2,4-triazole, 3-mercapto-
4-amino-5-heptadecyl-1,2,4-triazo
, 2-mercapto-5-phenyl-1,3,4-thiol
Asiazole, 2-mercapto-5-phenyl-1,
3,4-thiadiazole, 2-mercapto-5-n-f
Butyl-oxathiazole, 2-mercapto-5-fe
Nyl-1,3,4-oxadiazole, 2-heptadeci
5-5-phenyl-1,3,4-oxadiazole, 5
-Mercapto-1-phenyl-tetrazole, 2-mer
Capto-5-nitropyridine, 1-methyl-quinoline-
2 (1H) -thione, 3-mercapto-4-methyl-6
-Phenyl-pyridazine, 2-mercapto-5,6-di
Phenyl-pyrazine, 2-mercapto-4,6-dife
Nyl-1,3,5-triazine, 2-amino-4-mer
Capto-6-benzyl-1,3,5-triazine, 1,
5-dimercapto-3,7-diphenyl-S-triazo
Reno [1,2-a] -S-triazoline and the like
However, the present invention is not limited to these. The mercapto group or thiol group used in the present invention
The amount of the compound having an ON group is per 1 liter of the plate surface treatment solution.
0.01 to 10 g, preferably 0.02 to 5 g
Add within the range. The mercapto group or thiol group used in the present invention
Neutral to weakly acidic compounds mainly containing water
For example, the method of dissolving in a plate surface treatment solution (pH 5 to 7)
For example, a method of adjusting pH by dissolving with an alkaline solution, amine
Compound-based method, quaternary ammonium salt type cation field
Although various methods such as a method using a surfactant can be considered,
A method using an amine compound, but is not limited to these
Not something. As described above, in the present invention, the organic
Solvents, especially organic solvents having a low boiling point (100 ° C. or lower), for example,
Ethyl alcohol, isopropyl alcohol, etc. are substantial
Not to be used for
20% or less, especially 1% with respect to the processing solution.
The present invention works effectively even when the amount is 0% or less. The above amine compound is, for example, monoethanol
Luamine, diethanolamine, triethanolamine
Amino alcohols such as aminoethylethanolamine
, Monoamines such as propylamine and butylamine
, Diamines such as dimethylaminoethylamine, N-
Polyamines such as aminopropylpropanediamine and
Cyclic amines such as pyridine and piperidine; Preferred
These are amino alcohols. These amine compounds
Is obtained from Nippon Emulsifier Co., Ltd., Koei Chemical Industry Co., Ltd., etc.
Rukoto can. The amine compound used in the present invention is as described above.
: 1 to 100:
1, preferably in the range of 1: 1 to 50: 1
You. Then, if necessary, other compounds and the like are added to the mixed solution.
Prepared by addition. In addition to the above-mentioned compounds, the plate surface treating solution may contain
Commonly used buffers, preservatives, preservatives, wetting agents and
Surfactants and the like can be mixed. For example, a buffer
Include inorganic acids such as phosphoric acid and sulfuric acid, succinic acid, citric acid, etc.
Organic acids can be used, but phosphoric acid is preferred.
You. Phosphoric acid includes orthophosphoric acid, metaphosphoric acid, polyphosphoric acid,
These salts may be used. Furthermore, iminodiacetic acid, d
Complexing agents such as tylenediaminetetraacetic acid can also be mixed.
You. In addition, inorganic fine particles such as colloidal silica
Mix as long as the action of the compound having
Rukoto can. A more preferred embodiment of the present invention further comprises:
(1) Number average molecular weight of about 20,000 or less having a carboxyl group
Water-soluble polymer of (2) formalin aromatic sulfonic acid
Compound, (3) anion field having polyoxyethylene group
Surfactants or (4) organic disulfide compounds
Is to have. The compounds of the above (1) to (4) are treated with
Of compounds having two or more mercapto groups in the lipophilicity
To prevent the deterioration of the force, JP-A-2-251490,
2-103185, 2-103187, 2-
No. 284,146. However,
These compounds are combined with the copolymer of the above formula (2).
Group or thione group in a solution of pH 5-7
The dissolution state of the compound having
Preventing precipitation under conditions almost completely is an unexpected finding
Met. The compound used in the above (1) is
Number having a xyl group (including its salt or acid anhydride)
It is a water-soluble polymer having an average molecular weight of about 20,000 or less. Such a water-soluble polymer is composed of a single monomer.
System Desaturation Containing Carboxyl Group as Position
Compounds, such as acrylic acid, methacrylic acid, maleic acid,
Homopolymers such as sorbic acid and itaconic acid
Olefins containing carboxyl groups as mer units
A saturated compound and a vinyl monomer copolymerizable therewith;
Can be a copolymer of The above-mentioned copolymer having a carboxy group is obtained.
Styrene as the vinyl monomer for
Alkyl-substituted styrene such as methyl and ethyl, methoxy, etc.
Halogen-substituted styrene, chloro, etc.
Styrene derivatives such as styrene, ethylene, butylene, etc.
Of ethylenically unsaturated monoolefins, vinyl chloride, etc.
Vinyl esters such as vinyl halides and vinyl acetate
Or acrylic acid or methacrylic acid such as methyl or isobutyl
Alkyl esters of luic acid, vinyl ether, vinyl na
Phthalenes and the like;
Different olefinic unsaturated compounds, including copolymer components
May be used. Lipophilic, especially styrene
It is particularly preferable to use a copolymer component containing a hydrophilic vinyl monomer.
Good. The copolymer containing a carboxyl group in the copolymer
Lefin-based unsaturated material is at least about 10% by weight, preferably
Is 20% by weight or less. This carboxyl group is
It may be in the form of a salt such as lium, potassium, etc.
It may be. The above water-soluble polymer having a carboxy group
Has a number average molecular weight of about 20,000 or less, and
Particularly, those having a range of about 1,000 to 15,000 are preferable. These water-soluble polymers can be used for solution polymerization and the like.
Can be easily manufactured by known manufacturing methods of
It can also be obtained as a commercial product. This water-soluble polymer
Content in the neutralized solution is about 0.1% to 20% (weight
Concentration) is appropriate. Mercapto group or thio
About 1 to 100 times (weight
Ratio) is preferred. Specific examples are shown below. The polymerization ratio is heavy
The amount is shown in%. Embedded image Embedded image Embedded image Embedded image The formalin aromatic sulfonic acid of the above (2)
The condensate is β-naphthalene sulfone contained in the following chemical formula 8
Sodium formalin condensate, methyl naphthalene sulfone
Sodium formalin condensate is a typical example
You. These compounds are commercially available from various manufacturers.
And can be easily obtained. Embedded image (N is an integer of 1 or more, preferably 2 to 5.
M represents a cation such as a hydrogen atom or an alkali metal atom.) These activators may be used in combination of two or more kinds.
No. The content of this activator is from about 0.1% to 2%.
A concentration range of 0% (weight) is appropriate. Mercapto group
Or about 1 to 100 for compounds containing a thione group.
A double (weight ratio) combination is preferred. Having the above polyoxyethylene group (3)
The anionic surfactant is represented by the following chemical formula 9. Embedded image R is a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms,
Represents an alkenyl group or an aryl group. Q is O, S, CO
O, -N (R ₁ )-, -N (R ₁ ) CO-, -N (R ₁ )
SO _Two − (R ₁ Is a hydrogen atom, a substituted or unsubstituted alkyl
Represents a hydroxyl group. B is an alkylene group, an arylene group, an oxypropylene group
And the like. m is 0 or an integer of 1 or more
You. n is the average degree of polymerization of ethylene oxide, 1-50,
Preferably it is 2-10. A is Chemical formula 10. Embedded image M is a hydrogen atom, an alkali metal, an alkaline earth metal,
Shows cations such as monium, lower alkylamine, etc.
You. The description of B, Q, R, m, and n has the same meaning as in Chemical formula 9. These compounds are disclosed in US Pat.
Nos. 2 and 260831, JP-A-54-98235
And Japanese Patent Publication No. 40-23747. An ani having the polyoxyethylene of the present invention
Specific examples of the on-surfactant are shown below. However, CH _Two C
H _Two O is abbreviated as EO. Embedded image Embedded image Embedded image Embedded image Embedded image The aniline containing these polyoxyethylenes
On-surfactants are available from manufacturers as anionic surfactants.
And can be easily obtained. The content of this activator
Is suitably about 0.1% to 20% (% by weight).
About compounds containing a rucapto or thione group.
A combination of 1 to 100 times (weight ratio) is preferred. The organic disulfide compound of the above (4)
Are shown below. Embedded image Embedded image Embedded image The content of this compound ranges from about 0.1% to 2%.
A range of 0% (weight) is appropriate, and a mercapto group or
About 1/10 to 10 for compounds containing a thione group
A double (weight ratio) combination ratio is preferred. Lithographic plate utilizing image silver as ink acceptability
For the printing plate, the silver halide emulsion is the printing plate itself
Or an image receiving layer by silver diffusion transfer method.
Another negative source as a silver source for the
It may be provided on a sheet. The silver halide emulsion includes silver chloride, silver bromide,
Either silver chlorobromide or those containing iodide
This binder is preferably gelatin, but
Some or all of the chin may be replaced by another colloidal substance, such as casei.
, Albumin, cellulose derivatives, etc.
No. Silver halide is 0.5-7 g / m in terms of silver nitrate
^Two , Binder is 0.5-10g / m ^Two Usually used in the range
You can do it. A method for producing a silver halide emulsion is described in a conventional photographic method.
Can be manufactured by methods known in the industry, especially for printing plates
Manufacturing methods for use are also disclosed in the above-mentioned known patent documents.
Can be used as a reference. The lithographic printing plate used in the present invention generally comprises
After exposure, it is processed with an alkali developing solution. Such a developer is
Normal photographic development including a developing agent such as idroquinone
Solution of silver diffusion transfer method containing liquid, hypo or the like
Any activator such as a high alkali developer
Anything can be used. EXAMPLES The present invention will be described below with reference to examples.
However, the present invention is not limited to this. Example 1 A flat surface of a polyester film support subjected to an undercoating treatment was
Matting layer containing silica particles having a uniform particle size of 5μ
Provide the amount of carbon on the opposite side that gives a light reflectance of 3%
Contains black, 20% by weight of photographic gelatin
Under antihalation containing silica powder with average particle size 7μ
Coating layer (adjusted to pH 4), average grain after chemical sensitization
5% by weight of silica powder with a diameter of 7μ based on photographic gelatin
Sensitivity sensitized spectrally sensitized to the green region containing
Silver emulsion (adjusted to pH 4). The gelatin of the undercoat layer was 3.5 g / m ^Two ,milk
0.8g / m2 gelatin in agent layer ^Two , Converted to silver nitrate
1.0 g / m ^Two Was applied at a rate of Under this
Formalin and gelatin are used as hardening agents
On the other hand, it contains 5.0 mg / g gelatin. After drying
After heating at 40 ° C. for 14 days, the emulsion layer was
No. 54-103104, plate No. 2 of Example 2; 31
The nucleus coating solution described above is applied and dried to produce a lithographic printing plate.
The silver halide emulsion contains 1 mole of silver halide at the time of physical ripening.
4 × 10 per ^-6 With the addition of moles of rhodium chloride
And an average particle size of 0.4 microns. The lithographic printing plate thus obtained is
Image exposure using a plate making camera with an image reversing mechanism
Developing treatment was performed at 30 ° C. for 30 seconds using the liquid (used liquid). <Developer> Sodium hydroxide 24 g Potassium hydroxide 8 g Anhydrous sodium sulfite 50 g 2-Methyl-2-amino-1-fluorophenol 30 g Mercapto compound 0.2 g Make up to 1 liter with water. The mercapto compound is 2-mercapto-5-n-heptyl
Oxadiazole. After the above development processing, neutralization as shown below
Treatment at room temperature for 20 seconds with a fresh solution (stabilizing solution)
Was. Also, put the following neutralizing solution (stabilizing solution) in a plastic container,
Perform a one-month aging test at 5 ° C.
A printing test and the presence or absence of the precipitation of the mercapto compound were examined. <Neutralized solution> Phosphoric acid 1.2 g Sodium monophosphate 25 g Ethylene glycol 5 g Mercapto compound 0.2 g Diethanolamine 5 g Compound B 0.2 g Make up to 1 l with water. (Adjusted to pH 6) Combinations of mercapto compounds and compound B are as shown in Table 1.
It is. The printing plate created by the above operation is
Set on the printing press, and put Abdick 12 on the printing press.
50 (trademark of offset printing machine manufactured by AB-Dick),
The ink is AB-Dick3-1012 black ink, moisture supply
Use OD30 (humidifying liquid manufactured by Mitsubishi Paper Mills) as the liquid,
Etching was performed and printing was performed. [Table 1] The developer and compound B in Table 1 were not
Sulfonated water maleic acid copolymer (polymerization ratio 3/1
(Styrene / maleic anhydride), molecular weight 3000),
Lcapto compound C is 2-mercapto-5-n-heptyl
-Oxadiazole, wherein D is 3-pentyl-benzooxy
Sazolin-2-thione, E is 3-mercapto-5-noni
Ru-1,2,4, -triazole. The ink acceptability was evaluated by contacting the plate surface with the ink.
Touch the paper as soon as you touch it,
Evaluated as the number of prints until a print without unevenness is obtained
did. Table 2 shows the printing results and the results of the aging test. [Table 2] According to an embodiment of the present invention, ink acceptability
, A neutralized solution having excellent aging properties was obtained. Example 2 A neutralizing solution F shown below was prepared, and was stored at 5 ° C. or lower for 5 months.
Of fresh solution and aging as in Example 1.
A treatment with a post-treatment liquid was performed, and a similar test was performed. Combination
The results are shown in Table 3 and the results are shown in Table 4. <Neutralizing solution> Phosphoric acid 1.2 g Sodium monophosphate 25 g Ethylene glycol 5 g Mercapto compound 0.2 g Diethanolamine 5 g Compound B 0.2 g Compound G 0.2 g Make up to 1 l with water. (Adjusted to pH 6) Compound B is a copolymer of styrene and maleic anhydride.
Merged sulfonate (polymerization ratio 3/1 (styrene / anhydride
Maleic acid), molecular weight 3000), mercapto compound 2
-Mercapto-5-n-heptyl-oxadiazole
is there. [Table 3] The surfactant H in the table is β-naphthalene
It is a sodium sulfonate formalin condensate. [Table 4] From the above results, it was found that styrene and maleic anhydride
5. A sulfonated product of a copolymer represented by the formula:
Can be used in more severe conditions
Prevents the precipitation of mercapto compounds, but has high ink acceptability
Was maintained stably. Example 3 After development with the developing solution of Example 1, processing was carried out with the following neutralizing solution J.
Created a new printing plate. <Neutralizing solution J> Phosphoric acid 1.2 g Sodium monophosphate 25 g Ethylene glycol 5 g Make up to 1 liter with water. (Adjusted to pH 6) The printing plate prepared as described above was
Etching is performed using the etchant K shown in FIG.
Was subjected to a printing test. In addition, a aging test of the etchant K was also performed.
Performed in the same manner as in Example 1,
A similar printing test was performed. <Etching liquid I> Monosodium phosphate 15 g Colloidal silica (20% solution) 10 g Mercapto compound 0.5 g Diethanolamine 10 g Compound B 0.5 g Make up to 1 l with water. (Adjusted to pH 6) Combinations of mercapto compounds and compound B are as shown in Table 5.
It is. [Table 5] Compound B in Table 5 is styrene and anhydrous maleic.
Sulfonate of acid copolymer (polymerization ratio 3/1 (styrene
/ Maleic anhydride), molecular weight 3000), mercapto
Compound C is 2-mercapto-5-n-heptyl-oxadi
An azole, wherein D is 3-pentyl-benzoxazoline-
2-thione, E is 3-mercapto-5-nonyl-1,
2,4, -triazole. Printing results and aging tests
The results are shown in Table 6. [Table 6] According to an embodiment of the present invention, ink acceptability
Was obtained, and an etchant having excellent aging properties was obtained. Example 4 An etching solution L shown below was prepared, and was kept at 5 ° C. or less for 5 months.
Aging test and the same treatment as in Example 3
Was tested. The combinations are shown in Table 7 and the results are shown in Table 8.
Was. <Etching liquid L> Monosodium phosphate 15 g Colloidal silica (20% solution) 10 g Mercapto compound 0.5 g Diethanolamine 10 g Compound B 0.5 g Compound G 0.3 g Make up to 1 l with water. (Adjusted to pH 6) Compound B is a copolymer of styrene and maleic anhydride.
Merged sulfonate (polymerization ratio 3/1 (styrene / anhydride
Maleic acid), molecular weight 3000), mercapto compound 2
-Mercapto-5-n-heptyl-oxadiazole
is there. [Table 7] The surfactant H in the table is β-naphthalene
It is a sodium sulfonate formalin condensate. [Table 8] From the above results, it was found that styrene and maleic anhydride
5. A sulfonated product of a copolymer represented by the formula:
Can be used in more severe conditions
Prevents the precipitation of mercapto compounds, but has high ink acceptability
Was maintained stably. According to the embodiment of the present invention, the image silver can be
For lithographic printing plates used for acceptability,
Stably containing a compound having a pt group or a thione group
To obtain stable ink receptivity
Can be.

Claims (1)

(57) [Claim 1] An image silver containing at least one water-insoluble compound having a mercapto group or a thione group, and a compound represented by the following formula 1, which has an ink receptivity: Plate surface treatment liquid for lithographic printing plates used as Embedded image (A is a vinyl monomer having a carboxy group, B is a copolymerizable ethylenically unsaturated monomer, M is a cation. L is 30 to 90 mol%, m is 10 to 50 mol%, n
Is 0 to 50 mol%. )