JP5281130B2 - Dampening solution composition for lithographic printing - Google Patents

Abstract

[Problems to be Solved] A fountain solution composition for lithographic printing, which is superior in preventing dirt at a non-image area of a lithographic plate, is provided. Especially, provided is a fountain solution composition for lithographic printing, which can attain high quality printing by mitigating dirt after a break caused by dirt at a non-image area of a plate at a restart of printing after a stop of a printing press, and further by suppressing decrease in the ink density at an image area, even when the component concentration of the fountain solution is increased. [Solution] A fountain solution composition for lithographic printing characterized by comprising a star polymer having at least one hydrophilic group; the fountain solution composition for lithographic printing, wherein the star polymer is a star polymer having 3 branches to 10 branches; the fountain solution composition for lithographic printing, wherein 3 branches to 10 branches of polymer chains are branched from a skeleton through sulfide bonds in the star polymer.; the fountain solution composition for lithographic printing, wherein the star polymer is a polymer having 3 branches to 10 branches of polymer chains branched from a skeleton through sulfide bonds, the polymer being obtained by polymerizing an ethylenic unsaturated monomer in the presence of a multifunctional thiol; the fountain solution composition for lithographic printing, wherein the star polymer further comprises at least one substrate adsorptive group; and the fountain solution composition for lithographic printing as a concentrated fountain solution composition.

Description

  The present invention relates to a fountain solution composition for lithographic printing, and more specifically to a fountain solution composition for lithographic printing used in an offset printing method.

Lithographic printing is a printing method that uses the property that water and oil do not essentially mix, and the printing plate surface is a non-image area that accepts water and repels oil-based ink, and an image area that repels water and accepts oil-based ink. Consists of. By moistening the non-image area with the fountain solution, the difference in interfacial chemistry with the image area is increased, and the ink repellency of the non-image area and the ink receptivity of the image area are increased.
A lithographic printing machine is usually an offset printing system, and ink and fountain solution are supplied onto the plate, ink is deposited on the image area, and fountain solution is deposited on the non-image area. The image on the plate is printed by transferring to a blanket and then transferring from the blanket to paper.

As a conventional fountain solution, an aqueous solution to which colloidal substances such as dichromate, phosphate, gum arabic, and carboxymethylcellulose (CMC) are added is known. However, when only these compounds are contained, the non-image area of the plate is difficult to wet uniformly, and there is a problem that the printed matter is soiled, and considerable skill is required to adjust the supply amount of dampening water. .
In order to remedy this drawback, a Dahlglen system has been proposed in which an aqueous solution containing about 20 to 25% of isopropyl alcohol is used as a fountain solution. However, since isopropyl alcohol is easy to evaporate, a special device for keeping the concentration in the dampening water constant is required. In addition, isopropyl alcohol has an unpleasant odor and is not preferable in the working environment.

In recent years, for example, a dampening solution containing a specific propylene glycol-based compound (see Patent Document 1) as a dampening solution not containing isopropyl alcohol, or a dampening solution containing a compound obtained by adding ethylene oxide and propylene oxide to ethylenediamine. A dampening solution (see Patent Document 4) containing water (see Patent Documents 2 and 3) and a compound obtained by adding ethylene oxide and propylene oxide to diethylenetriamine has been proposed. Patent Document 5 describes a printing chemical containing a water-soluble polymer having an adsorptive group and a sulfonic acid group that can be adsorbed on the surface of a lithographic printing plate support, as a printing chemical used for fountain solution or the like. ing. In Patent Document 6, a diol compound is added in order to solve the so-called blanket piling problem that ink components and paper components are gradually deposited on non-image portions on the blanket after continuous printing for a long time. It has been proposed.
On the other hand, as a problem during lithographic printing work, there is a problem that stains occur in the non-image area. Specifically, the printing machine is stopped for a while due to various reasons such as a break, and then the non-image area is slightly detected when printing is resumed. Spot-like dirt may be generated (this dirt is called stop dirt). Therefore, it is desirable to prevent the smearing of the non-image area at the time of lithographic printing (at the start of printing) or at the time of resumption, and to reduce the number of payable sheets as much as possible.
In order to prevent stains in the non-image area, it may be possible to increase the additive concentration or the like in the fountain solution. However, if the fountain solution concentration is increased, the amount of water in the image area increases, so the ink concentration decreases. As a result, the print quality may be degraded.

JP 2001-138655 A JP 2007-50665 A JP 2007-168124 A JP 2007-55182 A JP 2007-38483 A JP 2009-234247 A

Means for preventing the occurrence of stains on the plate surface of the non-image area as much as possible, and means for reducing the inconvenience caused by the stain on the plate surface of the non-image area and providing a high-quality printed matter efficiently Therefore, it is conceivable to devise from the viewpoint of the fountain solution composition as these means.
An object of the present invention is to provide a fountain solution for lithographic printing which is excellent in antifouling property for non-image areas of a lithographic printing plate. The object of the present invention is also to reduce so-called stop stains caused by non-image area stains when printing is started and after printing is stopped, and when the printing resumes, so-called stop stains caused by non-image area stains on the printing plate are effectively reduced. It is to provide a fountain solution for lithographic printing that can achieve quality printing.
A further object of the present invention is to provide a fountain solution for lithographic printing, which is less likely to cause a decrease in ink concentration in the image area and can achieve high quality printing even when the component concentration in the fountain solution is increased. Is to provide.

As a result of intensive studies, the present inventors have found that the above problems can be achieved by including a specific polymer in the fountain solution for lithographic printing, and have completed the present invention.
Accordingly, the present invention is a fountain solution for lithographic printing, comprising a star polymer having at least one hydrophilic group.
As the star polymer, those having at least one support-adsorptive group are also preferred.

The star polymer is preferably a star polymer having 3 to 10 branches.
As a specific structure of a star polymer, there is one in which a polymer chain is branched from 3 to 10 branches from a central skeleton via a sulfide bond, and more specifically, an ethylenic polymer in the presence of a polyfunctional thiol. There is a star polymer obtained by polymerizing a saturated monomer and having a polymer chain branched from 3 to 10 branches from a central skeleton via a sulfide bond.

Examples of at least one hydrophilic group in the star polymer of the present invention include a sulfonic acid group and a salt thereof, an amide group, a polyalkylene oxide group, a hydroxyl group, a sulfuric monoester group and a salt thereof, a sulfonamide group, and an amino group. , Sulfate monoamide group and salts thereof, and at least one group selected from the group consisting of betaine structures.
Examples of the support-adsorptive group in the star polymer include at least one group selected from the group consisting of a phosphonic acid group and a salt thereof, a phosphate ester group and a salt thereof, and a carboxylic acid group and a salt thereof. Can be mentioned.

A preferred embodiment of the present invention includes a fountain solution for lithographic printing containing a water-soluble polymer having no star structure. Examples of water-soluble polymers having no star structure include gum arabic, fibrin derivatives and modified products thereof, polyvinyl alcohol and derivatives thereof, polyvinyl pyrrolidone, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride Copolymer, styrene / maleic anhydride copolymer, water-soluble soybean polysaccharide, starch, starch derivative, pullulan and pullulan derivative, gelatin, and at least one water-soluble substance selected from the group consisting of hemicellulose extracted from soybean Functional polymer compounds.
The present invention is further directed to a fountain solution for lithographic printing which is in the form of a concentrated fountain solution having the above characteristics.

The fountain solution composition for lithographic printing of the present invention is excellent in the anti-staining property of the non-image area of the lithographic printing plate.
According to the fountain solution composition for lithographic printing of the present invention, after stopping the printing machine during the printing operation, the so-called stop stain caused by the stain of the non-image area is reduced when the printing is resumed, and the printed material is efficiently and high quality. Can be provided. Specifically, according to the fountain solution composition for lithographic printing of the present invention, it is possible to perform a printing operation that requires less so-called damaged paper. Here, the waste paper refers to the number of printed sheets required from the start of printing until the ink is completely removed from the non-image area in the printed matter. According to the fountain solution composition for lithographic printing of the present invention, it is possible to provide a good printed matter with a small amount of damaged paper when printing is resumed after the printing machine is stopped during the printing operation.
In addition, in order to prevent stains in the non-image area, even when the additive concentration in the fountain solution is increased, the ink density in the image area is prevented from decreasing, and as a result, a high-quality printed matter is provided. Can do.

The components of the fountain solution composition for lithographic printing according to the present invention will be described below.
[I] Star polymer The star polymer used in the present invention is a kind of branched polymer, particularly a polymer having a structure in which three or more chain polymers are bonded at one point. .
A typical example of the structure of the star polymer used in the present invention is as follows, consisting of the central skeleton A and the polymer chain Pl. That is, one end of a plurality of polymer chains Pl has a structure bonded to the central skeleton A, and a degree of branching of 3 to 10 is appropriate.

As long as the star polymer used in the present invention has the structure as described above, any star polymer can be used.
Examples of such star polymers include star polymers obtained by the coupling method and anion growth method described in “New Experimental Chemistry Course, Polymer Chemistry I”, edited by The Chemical Society of Japan, p. 208-210, and JP-A-10-279867. A star-shaped polymer obtained by a synthesis method in which a polymerization reaction is carried out under light irradiation using a compound containing a dithiocarbamate group and / or a compound containing a xanthate group described in the gazette as an initiator, or a polyfunctional thiol as a chain transfer agent And a star polymer obtained by ordinary radical polymerization.

  As the star polymer of the present invention, from the viewpoint of ease of synthesis and the performance of the obtained polymer, it is obtained from the central skeleton via a sulfide bond obtained by polymerizing an ethylenically unsaturated monomer in the presence of a polyfunctional thiol. A polymer having a branched polymer chain is preferred. That is, those having a hub portion that is a residue of a thiol having 3 or more functionalities as a central skeleton are preferable. In an idealized structure, the addition polymer backbone extends from each thio moiety in the hub. Therefore, three or more main chains extend from the thio moiety. That is, the central skeleton A preferably has a structure represented by the following general formula (1).

ここで、Ａ₁はｎ価の有機基であり、ｎは３以上の整数である。Ａ₁の具体例としては、下記の構造又はこれらの構造が複数組み合わさってｎ価の構成される有機基を挙げることができる。ｎは３〜１０の整数が好ましく、３〜８の整数がより好ましく、４〜８の整数が特に好ましい。

Here, A ₁ is an n-valent organic group, and n is an integer of 3 or more. Specific examples of A ₁ include the following structures or organic groups composed of n valences by combining a plurality of these structures. n is preferably an integer of 3 to 10, more preferably an integer of 3 to 8, and particularly preferably an integer of 4 to 8.

(Central skeleton of polymer with polymer chain branched via sulfide bond)
As the polyfunctional thiol used for the synthesis of the star polymer of the present invention, any compound having a plurality of thiol groups in one molecule can be suitably used. Thiols are preferred, thiols having 3 to 8 functions are more preferred, and thiols having 4 to 8 functions are particularly preferred.
Examples of such polyfunctional thiols include the following (Compound A) to (Compound F).

(Compound A)
Compound A is a compound obtained by a method in which an electrophile such as a halide or a sulfonic acid ester of alcohol is reacted with a sulfurizing agent such as thiourea, potassium thiocyanate, or thioacetic acid, followed by various treatments. Specific examples of compound A include the following compounds, but the present invention is not limited thereto.

(Compound B)
Compound B is a compound obtained by a dehydration condensation reaction between a polyfunctional alcohol and a carboxylic acid having a thiol group. Among them, a polyfunctional alcohol having 3 to 10 functionals and a monocarboxylic acid having one thiol group A compound obtained by a condensation reaction is preferred.

  Specific examples of the polyfunctional alcohol include cyclohexanetriol (3), glycerol (3), 2-hydroxymethyl-1,3-propanediol (3), 1,1,1-tris (hydroxymethyl) ethane (3). 1,2,4-butanetriol (3), trimethylolpropane (3), 1,2,3-trihydroxyhexane (3), 1,2,6-trihydroxyhexane (3), 1,2, 3-heptanetriol (3), pyrogallol (3), 1,2,4-benzenetriol (3), phloroglucinol (3), 1,1,1-tris (4-hydroxyphenyl) ethane (3), 1,3,5-tris (2-hydroxyethyl) isocyanurate (3), pentaerythritol (4), threitol (4), erythritol (4), xylulo (4), ribulose (4), quebrachitol (5), adonitol (5), arabitol (5), xylitol (5), catechin (5), epicatechin (5), inositol (6), sorbitol ( 6), mannitol (6), iditol (6), dulcitol (6), dipentaerythritol (6), tripentaerythritol (8). In addition, the number in () shows the number of functional groups.

  Among these polyfunctional alcohols, cyclohexanetriol, glycerol (3), 2-hydroxymethyl-1,3-propanediol (3), 1,1,1-tris (hydroxymethyl) ethane (3), trimethylolpropane (3), Phloroglucinol (3), 1,1,1-tris (4-hydroxyphenyl) ethane (3), 1,3,5-tris (2-hydroxyethyl) isocyanurate (3), pentaerythritol (4), catechin (5), epicatechin (5), inositol (6), dipentaerythritol (6), tripentaerythritol (8) are preferred, cyclohexanetriol, 2-hydroxymethyl-1,3-propanediol (3), 1,1,1-tris (hydroxymethyl) ethane (3), trimethylol Lopan (3), phloroglucinol (3), 1,1,1-tris (4-hydroxyphenyl) ethane (3), 1,3,5-tris (2-hydroxyethyl) isocyanurate (3), penta Erythritol (4), catechin (5), epicatechin (5), inositol (6), dipentaerythritol (6), tripentaerythritol (8) are more preferred, and 1,3,5-tris (2-hydroxyethyl) ) Isocyanurate (3), pentaerythritol (4), catechin (5), epicatechin (5), inositol (6), dipentaerythritol (6) and tripentaerythritol (8) are particularly preferred. In addition, the number in () shows the number of functional groups.

Specific examples of monocarboxylic acids having one thiol group include mercaptoacetic acid, 3-mercaptopropionic acid, 2-mercaptopropionic acid, 3-mercaptoisobutyric acid, N-acetylcysteine, and N- (2-mercaptopropionyl) glycine. And thiosalicylic acid.
Mercaptoacetic acid, 3-mercaptopropionic acid, 2-mercaptopropionic acid, 3-mercaptoisobutyric acid, N-acetylcysteine, N- (2-mercaptopropionyl) glycine are preferred, 3-mercaptopropionic acid, 2-mercaptopropionic acid, 3-mercaptoisobutyric acid, N-acetylcysteine, and N- (2-mercaptopropionyl) glycine are more preferable, and 3-mercaptopropionic acid, 3-mercaptoisobutyric acid, N-acetylcysteine, and N- (2-mercaptopropionyl) glycine Is particularly preferred.
Specific examples of compound B include the following compounds, but are not limited thereto.

Among the specific examples in Table 1, SB-1 to SB-34, SB-36 to SB-48, SB-50 to SB-55, SB-57 to SB-62, and SB-64 to SB- are preferable. 69, SB-71 to SB-76, SB-78 to SB-111, SB-113 to SB-118, SB-120 to SB-125, SB-127 to SB-132, SB-134 to SB-139, SB-141 to SB-146, SB-148 to SB-153, SB-155 to SB-181, SB-183 to SB-188, SB-190 to SB-195, SB-197 to SB-202, SB- 204 to SB-217, more preferably SB-1 to SB-6, SB-9 to SB-13, SB-15 to SB-20, SB-22 to SB-27, SB-36 to SB. -41, SB-78 to SB-8 SB-85-SB-90, SB-92-SB-97, SB-99-SB-104, SB-155-SB-160, SB-162-SB-167, SB-169-SB-174, SB -204 to SB-209, SB-211 to SB-216, and particularly preferable are SB-2 to SB-6, SB-16 to SB-20, SB-23 to SB-27, SB-37 to SB-41, SB-79 to SB-83, SB-86 to SB-90, SB-93 to SB-97, SB-100 to SB-104, SB-156 to SB-160, SB-163 to SB- 167, SB-170 to SB-174, SB-205 to SB-209, and SB-212 to SB-216.
Since these polyfunctional thiols have a long distance between thiol groups and a small steric hindrance, they can form a desired star structure.

(Compound C)
Compound C is a compound obtained by a dehydration condensation reaction between a polyfunctional amine and a carboxylic acid having a thiol group. Among these, a compound obtained by a condensation reaction between a polyfunctional amine having 3 to 10 functional groups and a monocarboxylic acid having one thiol group is preferable.

  Specific examples of the polyfunctional amine include diethylenetriamine (3), N- (2-aminoethyl) -1,3-propanediamine (3), N- (3-aminopropyl) -1,3-propanediamine (3). , Spermidine (3), bis (hexamethylene) triamine (3), 4- (aminomethyl) -1,8-octanediamine (3), triethylenetetramine (4), 1,4,7,11-tetraaza Undecane (4), N, N'-bis (3-aminopropyl) ethylenediamine (4), N, N'-bis (2-aminoethyl) -1,3-propanediamine (4), N, N'- Bis (3-aminopropyl) -1,3-propanediamine (4), spermine (4), tris (2-aminoethyl) amine (3), tetraethylenepentamine (5), pentaethylene Xamine (6), 1,4,7-triazacyclononane (3), 1,5,9-triazacyclododecane (3), cyclen (4), 1,4,8,11-tetraazacyclotetradecane (4), 1,4,8,12-tetraazacyclopentadecane (4), hexacyclene (6), 3,3′-diaminobenzidine (4), 1,2,4,5-benzenetetramine (4 ). In addition, the number in () shows the number of functional groups.

  Among these polyfunctional amines, 4- (aminomethyl) -1,8-octanediamine (3), triethylenetetramine (4), 1,4,7,11-tetraazaundecane (4), N, N ′ -Bis (3-aminopropyl) ethylenediamine (4), N, N'-bis (2-aminoethyl) -1,3-propanediamine (4), N, N'-bis (3-aminopropyl) -1 , 3-propanediamine (4), spermine (4), tris (2-aminoethyl) amine (3), tetraethylenepentamine (5), pentaethylenehexamine (6), cyclen (4), hexacyclene ( 6) is preferred, 4- (aminomethyl) -1,8-octanediamine (3), tris (2-aminoethyl) amine (3), tetraethylenepentamine (5), pentaethylene Hexamine (6), cyclen (4), more preferably hex Sai Clen (6), tetraethylenepentamine (5), pentaethylenehexamine (6), cyclen (4), hexa Sai Clen (6) is particularly preferred.

  Specific examples of the carboxylic acid having a thiol group include the carboxylic acids described in Compound B above. Specific examples of this compound include the following compounds. The present invention is not limited to these.

Among the specific examples in Table 2, SC-1 to SC-6, SC-8 to SC-13, SC-15 to SC-20, SC-22 to SC-27, SC-29 to SC- are preferable. 34, SC-36 to SC-111, SC-113 to SC-118, SC-120 to SC-132, SC-134 to SC-139, SC-141 to SC-147, more preferably SC- 37-SC-41, SC-44-SC-48, SC-51-SC-55, SC-58-SC-62, SC-65-SC-69, SC-72-SC-76, SC-79- SC-83, SC-86 to SC-90, SC-93 to SC-97, SC-100 to SC-104, SC-121 to SC-125, SC-142 to SC-146, and particularly preferred SC-37 to SC-41, SC-86 to S -90, an SC-93~SC-97, SC-100~SC-104, SC-121~SC-125, SC-142~SC-146.
Since these polyfunctional thiols have a long distance between thiol groups and a small steric hindrance, they can form a desired star structure.

(Compound D)
Compound D is a compound obtained by a dehydration condensation reaction between a compound having an alcohol and an amine and a carboxylic acid having a thiol group, and has one polyfunctional alcohol amine having 3 to 10 functional alcohols and amines and one thiol group. A compound obtained by a condensation reaction with a monocarboxylic acid is preferred.

Specific examples of the polyfunctional alcohol amine include diethanolamine (3), serinol (3), diisopropanolamine (3), 2-amino-2-ethyl-1,3-propanediol (3), and 2-amino-2. -Methyl-1,3-propanediol (3), tris (hydroxymethyl) aminomethane (4), bis-homotris (4), 1,3-diamino-2-hydroxypropane (3), 2- (2- Aminoethylamino) ethanol (3), N, N′-bis (2-hydroxyethyl) ethylenediamine (4), 1,3-bis [tris (hydroxymethyl) methylamino] propane (8), 1-amino-1 -Deoxy-D-sorbitol (6), N-methyl-D-glucamine (6), 2,3-diaminophenol (3), 4-aminoresorcinol (3), norphenylephrine (3), octopamine (3), synephrine (3), 3,4-dihydroxybenzylamine (3), 3-hydroxytyramine (3), norephinephrine (4), 5-hydroxydopamine (4), 6-hydroxydopamine (4), serinol (3), 2-amino-2-methyl-1,3-propanediol (3), tris (hydroxymethyl) aminomethane (4), bis -Homotris (4), 1,3-diamino-2-hydroxypropane (3), N, N'-bis (2-hydroxyethyl) ethylenediamine (4), 1,3-bis [tris (hydroxymethyl) methylamino Propane (8), 1-amino-1-deoxy-D-sorbitol (6), N-methyl-D-glucamine (6), Norefinefuri (4), 5-hydroxydopamine (4), and 6-hydroxydopamine (4) are preferred, and tris (hydroxymethyl) aminomethane (4), bis-homotris (4), N, N′-bis (2- Hydroxyethyl) ethylenediamine (4), 1,3-bis [tris (hydroxymethyl) methylamino] propane (8), 1-amino-1-deoxy-D-sorbitol (6), N-methyl-D-glucamine ( 6), norephinephrine (4), 5-hydroxydopamine (4), and 6-hydroxydopamine (4) are particularly preferable. In addition, the number in () shows the number of functional groups.
Specific examples of the carboxylic acid having a thiol group include the carboxylic acids described in Compound B above. Specific examples of this compound include the following compounds. The present invention is not limited to these.

Among the specific examples in Table 3, SD-1 to SD-6, SD-8 to SD-20, SD-22 to SD-27, SD-29 to SD-62, SD-64 to SD- are preferable. 97, SD-99 to SD-104, SD-106 to SD-111, SD-113 to SD-118, SD-120 to SD-125, SD-127 to SD-132, SD-134 to SD-139, SD-141 to SD-161, more preferably SD-9 to SD-13, SD-30 to SD-34, SD-37 to SD-41, SD-44 to SD-48, SD-51 SD-55, SD-65 to SD-69, SD-72 to SD-76, SD-79 to SD-83, SD-86 to SD-90, SD-142 to SD-146, SD-149 to SD- 153, SD-156 to SD-160, SD-37 to SD-41, SD-44 to SD-48, SD-65 to SD-69, SD-72 to SD-76, SD-79 to SD-83, SD-86 to SD are preferable. -90, SD-142 to SD-146, SD-149 to SD-153, SD-156 to SD-160.
Since these polyfunctional thiols have a long distance between thiol groups and a small steric hindrance, they can form a desired star structure.

(Compound E)
Compound E is a compound obtained by a dehydration condensation reaction between a polyfunctional carboxylic acid and an alcohol having a thiol group. Among them, a polyfunctional carboxylic acid having 2 to 10 functionalities and an alcohol having one or more thiol groups A compound obtained by a condensation reaction is preferred.

  Specific examples of the polyfunctional carboxylic acid include oxalic acid (2), malonic acid (2), methyl malonic acid (2), succinic acid (2), methyl succinic acid (2), glutaric acid (2), adipic acid ( 2), pimelic acid (2), suberic acid (2), azelaic acid (2), sebacic acid (2), tricarbaliphosphoric acid (3), 1,2,3,4-butanetetracarboxylic acid (4) , Aconitic acid (3), hexafluoroglutaric acid (2), malic acid (2), tartaric acid (2), citric acid (3), diglycolic acid (2), 3,6-dioxaoctanedicarboxylic acid (2 ), Tetrahydrofuran-2,3,4,5-tetracarboxylic acid (4), mercaptosuccinic acid (2), thiodiglycolic acid (2), 2,2 ′, 2 ″, 2 ′ ″-[1,2 -Ethanediylidenetetrakis (thio)] tetrakis vinegar (4), 1,3,5-cyclohexanetricarboxylic acid (3), 1,2,3,4-cyclobutanetetracarboxylic acid (4), 1,2,3,4,5,6-cyclohexanehexacarboxylic acid ( 6), 1,2-phenylenediacetic acid (2), 1,2-phenylenedioxydiacetic acid (2), homophthalic acid (2), 1,3-phenylenediacetic acid (2), 4-carboxyphenoxyacetic acid ( 2), 1,4-phenylenediacetic acid (2), 1,4-phenylenedipropionic acid (2), phthalic acid (2), isophthalic acid (2), terephthalic acid (2), 1,2,3- Benzenetricarboxylic acid (3), 1,2,4-benzenetricarboxylic acid (3), 1,3,5-benzenetricarboxylic acid (3), 1,2,4,5-benzenetetracarboxylic acid (4), melittin Acid (6), 1, 4, 5, 8 Naphthalenetetracarboxylic acid (4), tricarbaliphosphoric acid (3), 1,2,3,4-butanetetracarboxylic acid (4), aconitic acid (3), citric acid (3), tetrahydrofuran-2 , 3,4,5-tetracarboxylic acid (4), mercaptosuccinic acid (2), 2,2 ′, 2 ″, 2 ′ ″-[1,2-ethanediylidenetetrakis (thio)] tetrakisacetic acid (4 ), 1,3,5-cyclohexanetricarboxylic acid (3), 1,2,3,4-cyclobutanetetracarboxylic acid (4), 1,2,3,4,5,6-cyclohexanehexacarboxylic acid (6) 1,2-phenylenediacetic acid (2), 1,2-phenylenedioxydiacetic acid (2), 1,3-phenylenediacetic acid (2), 1,4-phenylenediacetic acid (2), 1,4 -Phenylenedipropionic acid (2) , Phthalic acid (2), isophthalic acid (2), terephthalic acid (2), 1,3,5-benzenetricarboxylic acid (3), 1,2,4,5-benzenetetracarboxylic acid (4), melittic acid (6), 1,4,5,8-naphthalenetetracarboxylic acid (4) is preferable, tricarbaliphosphoric acid (3), 1,2,3,4-butanetetracarboxylic acid (4), tetrahydrofuran-2, 3,4,5-tetracarboxylic acid (4), mercaptosuccinic acid (2), 2,2 ′, 2 ″, 2 ′ ″-[1,2-ethanediylidenetetrakis (thio)] tetrakisacetic acid (4) 1,3,5-cyclohexanetricarboxylic acid (3), 1,2,3,4-cyclobutanetetracarboxylic acid (4), 1,2,3,4,5,6-cyclohexanehexacarboxylic acid (6), 1,3,5-benzenetrical Phosphate (3), 1,2,4,5-benzene tetracarboxylic acid (4), melittin acid (6), 1,4,5,8-naphthalene tetracarboxylic acid (4) is particularly preferred. In addition, the number in () shows the number of functional groups.

Specific examples of the alcohol having a thiol group include 2-mercaptoethanol (1), 1-mercapto-2-propanol (1), 3-mercapto-1-propanol (1), 3-mercapto-2-butanol (1 ), 2,3-dimercapto-1-propanol (2), 4-hydroxythiophenol (1), 2-mercaptoethanol (1), 3-mercapto-1-propanol (1), 2,3- Dimercapto-1-propanol (2) is preferred, 2-mercaptoethanol (1) and 3-mercapto-1-propanol (1) are more preferred, and 3-mercapto-1-propanol (1) is particularly preferred. The numbers in () indicate the number of functional groups.
Examples of this compound include, but are not limited to, the compounds listed in Table 4 and Table 5 below.

Of the specific examples in Tables 4 and 5, SE-12, SE-14, SE-16, SE-18, SE-20, SE-22, SE-24, SE-26, SE-33, SE-35, SE-41, SE-43, SE-45, SE-119, SE-121, SE-47, SE-49, SE-51, SE-53, SE-55, SE-57, SE- 59, SE-61, SE-63, SE-65, SE-67, SE-69, SE-71, SE-83, SE-85, SE-89, SE-91, SE-95, SE-97, SE-99, SE-101, SE-103, SE-105, SE-107, SE-109, SE-111, SE-113, SE-115, and SE-117 are preferred, and SE-12 is more preferred. , SE-14, SE-18, SE-20, SE-4 SE-43, SE-119, SE-121, SE-49, SE-51, SE-55, SE-57, SE-61, SE-63, SE-67, SE-69, SE-95, SE -97, SE-101, SE-103, SE-107, SE-109, SE-113, and SE-115.
Since these polyfunctional thiols have a long distance between thiol groups and a small steric hindrance, they can form a desired star structure.

(Compound F)
Compound F is a compound obtained by a dehydration condensation reaction between a polyfunctional carboxylic acid and an amine having a thiol group. Among them, a polyfunctional carboxylic acid having 2 to 10 functionals and an amine having one or more thiol groups A compound obtained by a condensation reaction is preferred.
Specific examples of the polyfunctional carboxylic acid include the aforementioned polyfunctional carboxylic acid. Specific examples of amines having one or more thiol groups include 2-aminoethanethiol, 2-aminothiophenol, 3-aminothiophenol, 4-aminothiophenol, 2-aminoethanethiol, 4-amino Thiophenol is preferred, and 2-aminoethanethiol is more preferred.
The following compounds are mentioned as an example of this compound. The present invention is not limited to these.

Among the specific examples in Table 6, SF-1, SF-4, SF-5, SF-8, SF-9, SF-13, SF-17, SF-20, SF-21, SF- are preferable. 24, SF-25, SF-28, SF-29, SF-32, SF-33, SF-36, SF-37, SF-40, SF-41, SF-45, SF-49, SF-52, SF-53, SF-56, SF-57, SF-60, SF-61, and SF-64 are preferable, and SF-1, SF-5, SF-17, SF-21, and SF-25 are more preferable. SF-29, SF-33, SF-37, SF-49, SF-53, SF-57, and SF-61.
Since these polyfunctional thiols have a long distance between thiol groups and a small steric hindrance, they can form a desired star structure.

  Among these polyfunctional thiols, Compound A to Compound E are preferable from the viewpoint of printing durability and developability, Compound A, Compound B, Compound C, and Compound E are more preferable, and Compound A, Compound B, and Compound C are particularly preferable. .

[Polymer chain]
Examples of the polymer chain in the star polymer used in the present invention include known vinyl polymers, (meth) acrylic acid polymers, and styrene polymers that can be produced by radical polymerization, and (meth) acrylic acid polymers are particularly preferred. preferable.

(Hydrophilic group)
The star polymer used in the present invention has at least one hydrophilic group. The polymer chain of the star polymer used in the present invention has at least one hydrophilic group in order to increase the hydrophilicity of the support surface and improve the soiling property. More preferably, the star polymer having at least one hydrophilic group contains a repeating unit having at least one hydrophilic group as a copolymerization component. The polymer chain of the star polymer used in the present invention can have one kind or two or more kinds of such hydrophilic groups.
Specific examples of the hydrophilic group are listed below.

In the above formula, M ¹ represents a hydrogen atom, a metal atom contained in an alkali metal or alkaline earth metal, or an ammonium group. X ⁺ is a group represented by -N ⁺ R ₁ R _2- , -S ⁺ R _1- , -I ⁺ -, or -P ⁺ R ₁ R _2- . R ₁ and R ₂ each independently represents a hydrogen atom, an alkyl group, an aryl group, an alkenyl group or an alkynyl group; R ₃ represents an alkylene group; and R ₄ represents a hydrogen atom, an alkyl group, an aryl group or an alkenyl group. Represents an alkynyl group. n represents an integer of 1 to 100.
L is synonymous with that defined in formula (B1) above.
More specifically, R ₁ is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group, and R ₂ is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, A hydrogen atom or a methyl group is preferable, R ₃ is an alkylene group having 2 to 5 carbon atoms, preferably ethylene or propylene, R ₄ is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and n is 2 to 90. An integer of is preferred.

  As the hydrophilic group, any functional group having high affinity with water can be suitably used. However, a sulfonic acid (salt) group, an amide group, a polyalkylene oxide group, a hydroxyl group, and a monosulfuric acid group can be used. Ester (salt) group, sulfonamide group, amino group, sulfuric monoamide (salt) group, betaine structure is preferable, sulfonic acid (salt) group, amide group, polyalkylene oxide group, hydroxyl group, sulfuric monoester (salt) group , Sulfonamido group, amino group, sulfuric monoamide (salt) group and betaine structure are more preferred, and sulfonic acid (salt) group, amide group, polyalkylene oxide group, hydroxyl group and betaine structure are particularly preferred.

  In the present invention, the repeating unit having a hydrophilic group is preferably represented by the following general formula (B2).

Wherein each R ^a to R ^c are independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom. L is as defined above. W represents a hydrophilic group, and a preferred embodiment is the same as described above.

  Specific examples of the repeating unit having a hydrophilic group in the polymer chain of the star polymer used in the present invention are shown below, but the present invention is not limited thereto.

The star polymer that can be used in the present invention may have a repeating unit having only one kind of hydrophilic group or may have a repeating unit having two or more kinds of hydrophilic groups.
The content ratio of the repeating unit having a hydrophilic group in the polymer chain of the star polymer that can be used in the present invention is preferably 30 to 98 mol% with respect to all the repeating units of the star polymer, More preferably, it is 90 mol%, and it is still more preferable that it is 50-90 mol%.

(Support adsorbing group)
The polymer chain of the star-shaped polymer used in the present invention interacts with the surface of the support and can be adsorbed on the surface of the support in order to enhance the adhesion to the support (referred to as a support adsorptive group). It is preferable to contain at least one kind. More preferably, the polymer chain of the star polymer used in the present invention preferably contains a repeating unit having at least one support-adsorptive group as a copolymerization component. Examples of functional groups that can interact and adsorb on the surface of the support include, for example, ionic bonds, hydrogen bonds, and polarities with metals, metal oxides, hydroxyl groups, etc. present on the support that has been subjected to anodization treatment or hydrophilization treatment. Examples include groups capable of interaction such as interaction. Examples of the support-adsorbing group include a phosphonic acid group or a salt thereof, a phosphate ester group or a salt thereof, and a carboxylic acid group or a salt thereof. The polymer chain of the star polymer used in the present invention can have one kind or two or more kinds of such support-adsorptive groups.
In the star polymer used in the present invention, “hydrophilic group” and “support adsorbing group” are groups different from each other. Therefore, when the star polymer has at least one hydrophilic group and at least one support-adsorptive group, it means that it has at least two functional groups.
Specific examples of the support-adsorptive group are listed below.

In the formula, M ¹ and M ² each independently represent a hydrogen atom, a metal atom contained in an alkali metal or an alkaline earth metal, or an ammonium group. From the viewpoint of dirtiness, at least one of the support-adsorptive groups is selected from a phosphonic acid group or a salt thereof (Structure 1), a phosphate ester group or a salt thereof (Structure 2), a carboxylic acid group or a salt thereof. Among them, a phosphoric acid ester group or a salt thereof, or a phosphonic acid group or a salt thereof is preferable. In the polymer chain of the star polymer used in the present invention, the repeating unit having at least one support-adsorptive group is specifically preferably represented by the following general formula (B1).

式中、Ｒ^a〜Ｒ^cはそれぞれ独立に、水素原子、炭素数１〜６のアルキル基、又はハロゲン原子を表す。Ｑは支持体吸着性基を表し、好ましい態様は上述したものと同じである。
Ｌは単結合、又は２価の連結基である。２価の連結基は、１から６０個までの炭素原子、０個から１０個までの窒素原子、０個から５０個までの酸素原子、１個から１００個までの水素原子、及び０個から２０個までの硫黄原子から成り、より具体的には、下記の構造単位が組み合わさって構成されるものを挙げることができる。

Wherein each R ^a to R ^c are independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom. Q represents a support-adsorptive group, and a preferred embodiment is the same as described above.
L is a single bond or a divalent linking group. A divalent linking group can be from 1 to 60 carbon atoms, 0 to 10 nitrogen atoms, 0 to 50 oxygen atoms, 1 to 100 hydrogen atoms, and 0 to It can be composed of up to 20 sulfur atoms, and more specifically, a combination of the following structural units.

上記構造において、Ｒ^d、Ｒ^eは水素原子、炭素数１〜２０のアルキル基、炭素数６〜２０のアリール基、又はハロゲン原子を表す。ｎは１〜４の整数を表す。

In the above structure, R ^d and R ^e represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a halogen atom. n represents an integer of 1 to 4.

  Specific examples of the repeating unit having at least one support-adsorbing group used in the present invention are shown below, but the present invention is not limited thereto.

The support adsorptive group in the star polymer of the present invention may be one type or two or more types.
The content ratio of the repeating unit having a support adsorptive group in the polymer chain of the star polymer that can be used in the present invention is preferably 2 to 80 mol% with respect to all the repeating units of the star polymer, It is more preferably 2 to 70 mol%, still more preferably 5 to 50 mol%, and particularly preferably 10 to 40 mol%.

(Other repeat units)
The polymer chain of the star polymer used in the present invention may be a copolymer having another repeating unit other than those described above (hereinafter sometimes simply referred to as “other repeating unit”). Here, examples of other repeating units include repeating units derived from various known monomers.

The polymer chain of the star polymer used in the present invention is, for example, a polymer unit of an alkyl (meth) acrylate or an aralkyl ester, in addition to the above-described repeating unit having a hydrophilic group and a repeating unit having a support-adsorbing group, It may have polymerized units of styrene derivatives.
The alkyl group of the (meth) acrylic acid alkyl ester is preferably an alkyl group having 1 to 5 carbon atoms and an alkyl group having the above-described substituent having 2 to 8 carbon atoms, and a methyl group is more preferable. Examples of (meth) acrylic acid aralkyl esters include benzyl (meth) acrylate.
(Styrene derivatives include styrene and 4-tertbutylstyrene.

  The content ratio of other repeating units in the polymer chain of the star polymer that can be used in the present invention is preferably 40 mol% or less, and preferably 30 mol%, based on all repeating units of the star polymer. Is more preferable, and it is still more preferable that it is 20 mol% or less.

  As a combination of a repeating unit having a support adsorptive group and a repeating unit having a hydrophilic group in the star polymer used in the present invention, the support adsorbing group is a phosphonic acid group or a salt thereof, a phosphate ester group or a salt thereof Or a carboxylic acid group or a salt thereof, wherein the hydrophilic group is preferably a sulfonic acid group or a salt thereof, an amide group, a polyalkylene oxide group, a hydroxyl group, or a betaine structure. Is more preferably a phosphonic acid group or a salt thereof, a phosphate ester group or a salt thereof, and the hydrophilic group is a sulfonic acid group or a salt thereof, a polyalkylene oxide group, a hydroxyl group, or a betaine structure. The body-adsorptive group is a phosphonic acid group or a salt thereof, a phosphate ester group or a salt thereof, and Aqueous group a sulfonic acid group or a salt thereof, polyalkylene oxide group, or, it is particularly preferred hydroxyl group, a.

The mass average molar mass (Mw) of the star polymer is preferably 5,000 or more, more preferably 10,000 or more, and preferably 1,000,000 or less, More preferably, it is 000 or less.
The number average molar mass (Mn) of the star polymer is preferably 1,000 or more, more preferably 2,000 or more, and preferably 500,000 or less, 300,000. The following is more preferable.
The polydispersity (Mw / Mn) of the star polymer is preferably 1.1-10.

Specific examples of the star polymer used in the present invention are shown in Tables 7 to 12 below, but the present invention is not limited thereto.
In addition, the star polymers shown in Tables 7 to 12 are polymers P _A -1, 2... Having a repeating unit (A) whose polymer chain has a hydrophilic group, and repeating polymers having a hydrophilic group. It is a polymer P _AB -1, 2,... Having a structure composed of a unit (A) and a repeating unit (B) having a support-adsorbing group.

^*1:モノマーを１００としたときのＳＨの当量

^{* 1} : SH equivalent when the monomer is 100

The fountain solution composition for lithographic printing of the present invention may contain one star polymer alone or two or more star polymers.
The content of the star polymer in the fountain solution for lithographic printing of the present invention is generally suitably 0.005 to 10% by mass in the fountain solution at the time of use. In addition, the effect of preventing smearing of the halftone image portion can be sufficiently obtained. The content is more preferably from 0.01 to 5% by mass, still more preferably from 0.1 to 3% by mass.
The fountain solution composition is preferably used after diluting the concentrated solution as appropriate during normal use, and the dilution rate is suitably about 10 to 200 times, particularly about 30 to 100 times. If the concentration rate is too high, problems such as precipitation and liquid separation in the concentrated solution are likely to occur. Hereinafter, the fountain solution composition in use is simply referred to as “fountain solution”.

[II] Other components As a solubilizing agent for preparing a concentrate, it is preferable to use a compound of the following general formula (I), and these compounds synergistically enhance the effects of the present invention.
Compounds of general formula (I) R ¹ —O— (CH ₂ CHR ² O) _m —H (I)
(In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms or an OH group, R ² represents a hydrogen atom or a methyl group, and m represents an integer of 1 to 5).
In the compound of general formula (I), specifically, in the formula, R ¹ represents an OH group or a linear or branched alkyl group having 1 to 4 carbon atoms, specifically, an OH group, a methyl group, There are an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group, and among them, an OH group, an n-butyl group, and a t-butyl group are particularly preferable. M represents an integer of 1 to 5, an integer of 1 to 3 is preferable, and 1 is particularly preferable.

Specific examples of the general formula (I) wherein R ¹ is an alkyl group include ethylene glycol mono t-butyl ether, ethylene glycol mono n-butyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol mono Ethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monoethyl ether, tetrapropylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monopropyl ether, propylene glycol monoisopropyl ether, Dipropylene glycol monoisopropyl ether, tripropylene glycol Cole monoisopropyl ether, propylene glycol mono n-butyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, propylene glycol monoisobutyl ether, dipropylene glycol monoisobutyl ether, tripropylene glycol monoisobutyl ether, propylene glycol monotertiary butyl ether Dipropylene glycol monotertiary butyl ether and tripropylene glycol monotertiary butyl ether. Of these, n-butyl or t-butyl ether of propylene glycol or ethylene glycol can be preferably used.

Specific examples of the general formula (I) wherein R ¹ is an OH group include propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol and pentapropylene glycol. Among these, in order to increase the solubility of the diol compound, propylene glycol, dipropylene glycol and tripropylene glycol are preferable, and propylene glycol is most preferable.

The compound represented by the general formula (I) is preferably used in combination of a plurality of the above-mentioned compounds. Particularly, when a compound in which R ¹ is an alkyl group and a compound in which R ¹ is an OH group are used in combination, it is highly effective in suppressing blanking. Moreover, roller stripping and the like can be prevented.

The fountain solution composition of the present invention also has, as a wetting solvent, 3-methoxy-3-methylbutanol, 3-methoxybutanol, ethylene glycol, diethylene glycol, triethylene glycol, butylene glycol, hexylene glycol, glycerin, diglycerin. Polyglycerin, trimethylolpropane and the like can be used.
These solvents may be used in the range of 0.1 to 3% by mass, preferably 0.3 to 2% by mass of dampening water.

In the fountain solution composition of the present invention, in addition to the above-mentioned star polymer, a water-soluble polymer compound that is usually added to the fountain solution composition can be included.
Examples of the water-soluble polymer compound used in the fountain solution composition of the present invention include gum arabic, starch derivatives (for example, dextrin, enzymatically degraded dextrin, hydroxypropylated enzymatically degraded dextrin, carboxymethylated starch, phosphate starch, Octenyl succinated starch), alginate, fibrin derivatives (for example, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose) and other natural products, polyethylene glycol and copolymers thereof, Polyvinyl alcohol and its derivatives, polyvinyl pyrrolidone, polyacrylamide and its copolymers, polyacrylic acid and its copolymers, vinyl methyl ether / maleic anhydride Acid copolymer, vinyl acetate / maleic anhydride copolymer include a composite of polystyrene sulfonic acid and copolymers thereof. Among the water-soluble polymer compounds, carboxymethylcellulose, polyvinylpyrrolidone, hydroxypropylcellulose, and hydroxypropylmethylcellulose can be particularly preferably used.
The molecular weight of these water-soluble polymer compounds is preferably 300 to 500,000, more preferably 300 to 100,000, and particularly preferably 500 to 30,000. The content of the water-soluble polymer compound is suitably 0.0001 to 0.1% by mass of dampening water, and more preferably 0.0005 to 0.05% by mass.

It is preferable that the fountain solution composition of the present invention is further adjusted to a preferred value by a pH adjuster. The pH value is preferably used in the acidic region in the range of 3 to 7, but can also be used in the alkaline region of pH 7 to 11. As said pH adjuster, water-soluble organic acid, inorganic acid, or those salts can be used.
Preferred organic acids include acetic acid, citric acid, succinic acid, malic acid, tartaric acid, succinic acid, lactic acid, ascorbic acid, gluconic acid, hydroxyacetic acid, malonic acid, levulinic acid, sulfanilic acid, p-toluenesulfonic acid, phytic acid, Examples include inorganic phosphonic acids, and examples of inorganic acids include phosphoric acid, nitric acid, sulfuric acid, and polyphosphoric acid, and alkali metal salts, alkaline earth metal salts or ammonium salts, and organic amine salts are also preferably used. . These may be used as a mixture of two or more. These pH adjusters generally have a content in the range of 0.001 to 0.3% by mass in the fountain solution.

  The fountain solution composition of the present invention preferably further contains a pyrrolidone derivative or acetylene glycol / acetylene alcohols as an aid for improving wettability. Examples of pyrrolidone derivatives include ethyl pyrrolidone, butyl pyrrolidone, pentapyrrolidone, hexapyrrolidone, octyl pyrrolidone, and lauryl pyrrolidone. Examples of acetylene glycol / acetylene alcohols include 3,5-dimethyl-1-hexyn-3-ol, 2 , 5-dimethyl-3-hexyne-2,5-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6- Examples thereof include diol, 2-butyne-1,4-diol, 3-methyl-1-butyn-3-ol, and ethylene oxide and / or propylene oxide adducts thereof. Of the above compounds, in particular octylpyrrolidone, 3,6-dimethyl-4-octyne-3,6-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, and 2,4 , 7,9-Tetramethyl-5-decyne-4,7-diol, preferably a compound having 4 to 10 ethylene oxides added thereto. These may be used at 0.0001 to 1.0% by mass of dampening water, and more preferably 0.001 to 0.1% by mass.

  In the fountain solution composition of the present invention, 2-ethyl-1,3 is also used to adjust the dynamic surface tension, solubilize, or suppress the mixing rate (emulsification rate) of the printing ink within an appropriate range. -Hexanediol, ethylene oxide and / or propylene oxide adduct of 2-ethyl-1,3-hexanediol, propylene oxide adduct of trimethylolpropane, propylene oxide adduct of glycerin, propylene oxide adduct of sorbitol, tetrahydrofluor It is preferable to add furyl alcohol and the like, and 2-ethyl-1,3-hexanediol is particularly preferable, and tetrahydrofurfuryl alcohol is preferable as a solubilizer. These compounds are suitably used at 0.01 to 7% by mass of dampening water, more preferably 0.05 to 5% by mass.

As other components of the fountain solution composition of the present invention, for example, a compound obtained by adding ethylene oxide and propylene oxide to ethylenediamine or diethylenetriamine can be further contained. Even when the remaining water droplets are left to evaporate and remain concentrated, the image area is not damaged. In these, the addition mole number ratio of ethylene oxide and propylene oxide is suitably in the range of 5:95 to 50:50, more preferably in the range of 20:80 to 35:65. Each copolymer chain may have a block structure or a random structure. The addition compound used in the present invention has a weight average molecular weight of preferably 500 to 5,000, more preferably 800 to 1,500, and most suitable is one having a weight average molecular weight of about 1000, and the molecular weight, ethylene oxide and propylene oxide. The ratio can be determined by, for example, measurement of hydroxyl value and amine value, NMR measurement, and the like.
By including 0.01 to 1% by mass, preferably 0.05 to 0.5% by mass of the above compound in the fountain solution composition, good printability is exhibited even if isopropyl alcohol is substituted. To do.

  In the fountain solution composition of the present invention, a surfactant can be further used as an aid for improving wettability. Among the surfactants, for example, anionic surfactants include fatty acid salts, abietic acid salts, hydroxyalkane sulfonic acid salts, alkane sulfonic acid salts, dialkyl sulfosuccinic acid salts, alkyl benzene sulfonic acid salts, alkyl naphthalene sulfonic acid salts, Alkylphenoxy polyoxyethylenepropyl sulfonates, polyoxyethylene alkylsulfenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkylsulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated castor oil, Sulfated tallow oil, sulfates of fatty acid alkyl esters, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxy Tylene alkylphenyl ether sulfate ester salt, polyoxyethylene styryl phenyl ether sulfate ester salt, alkyl phosphate ester salt, polyoxyethylene alkyl ether phosphate ester salt, polyoxyethylene alkylphenyl ether phosphate ester salt, styrene-maleic anhydride copolymer And partial saponification products of olefin-maleic anhydride copolymer, naphthalene sulfonate formalin condensates, and the like. Among these, dialkyl sulfosuccinates, alkyl sulfates and alkyl naphthalene sulfonates are particularly preferably used.

Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan Fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol mono fatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, poly Glycerin fatty acid partial esters, polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial esters, fatty acid die Noruamido acids, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, and trialkylamine oxides.
Of these, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene-polyoxypropylene block polymers, polyoxyethylene castor oil ether, and the like are preferably used.
In addition, fluorine-based surfactants and silicon-based surfactants can also be used.
In the case of using a surfactant, considering the foaming point, the content thereof is 1.0% by mass or less, preferably 0.001 to 0.5% by mass of dampening water.

The fountain solution composition of the present invention may contain saccharides. Sugars used include sugar alcohols obtained by hydrogenation.
Specific examples of preferred saccharides include D-erythrose, D-throse, D-arabinose, D-ribose, D-xylose, D-erythro-pentulose, D-allulose, D-galactose, D-glucose, D-mannose, D-talose, β-D-fructose, α-L-sorbose, 6-deoxy-D-glucose, D-glycero-D-galactose, α-D-allo-heptulose, β-D-altro-3-heptulose, Saccharose, lactose, D-maltose, isomaltose, inulobiose, hyalbiouron, maltotriose, D, L-arabit, rebit, xylit, D, L-sorbit, D, L-mannit, D, L-idit, D, L-Talit, Zulsit, Allozulsit, Maltitol, etc. And the like. These saccharides may be used alone or in combination of two or more.
The saccharide content is suitably 0.01 to 1% by mass, preferably 0.1 to 0.8% by mass, of dampening water.

In the fountain solution composition of the present invention, calcium ions or the like contained in tap water or well water for diluting the concentrated liquid at the time of use may adversely affect printing and cause the printed matter to become dirty. In such a case, the above disadvantages can be eliminated by adding a chelating agent. Preferred chelating agents include potassium salts of the following acids and sodium salts thereof. Examples of the acid include ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, hydroxyethylethylenediaminetriacetic acid, nitrilotriacetic acid, 1-hydroxyethane-1,1-diphosphonic acid, and aminotri (methylenephosphonic acid). Organic phosphonic acids or phosphonoalkanetricarboxylic acids. An organic amine salt is also effective in place of the sodium salt or potassium salt of the chelating agent.
These chelating agents are selected so that they are stably present in the fountain solution composition at the time of use and do not impair the printability. As content of the chelate compound in the dampening water composition at the time of use, 0.001-0.5 mass% is suitable, Preferably it is 0.002-0.25 mass%.

  The fountain solution composition of the present invention may contain an ester that has been conventionally used as a fragrance as an odor masking agent. Among them, preferred are n-pentyl acetate, isopentyl acetate, n-butyl butyrate, n-pentyl butyrate and isopentyl butyrate, and n-butyl butyrate, n-pentyl butyrate and isopentyl butyrate are particularly preferable.

  The fountain solution composition of the present invention may contain a preservative. Examples of the preservative include phenol or a derivative thereof, formalin, imidazole derivative, sodium dehydroacetate, 4-isothiazolin-3-one derivative, and benztriazole derivative. , Derivatives of amidine or guanidine, quaternary ammonium salts, derivatives of pyridine, quinoline or guanidine, derivatives of diazine or triazole, derivatives of oxazole or oxazine, bromonitropropanol based on bromonitroalcohol, 2,2-dibromo-2-nitro Examples include ethanol and 3-bromo-3-nitropentane-2,4-diol. A preferable addition amount is an amount that exerts a stable effect on bacteria, molds, yeast, etc., and is preferably in the range of 0.001 to 1.0% by mass of dampening water, and various molds, bacteria, It is preferable to use two or more preservatives that are effective against yeast.

In the fountain solution composition of the present invention, a food colorant or the like can be preferably used as a colorant. For example, CI No. 19140, 15985 as a yellow colorant, CI No. 16185, 45430, 16255, 45380, 45100, a purple colorant as a red colorant. CI No. 42640, CI No. 42090 and 73015 as blue dyes, CI No. 42095 as green dyes, and the like.
Examples of the rust inhibitor usable in the present invention include benzotriazole, 5-methylbenzotriazole, thiosalicylic acid, benzimidazole and derivatives thereof.
As the antifoaming agent that can be used in the present invention, a silicon antifoaming agent is preferable, and any of emulsifying dispersion type and solubilizing type can be used.

The balance is water as a component of the fountain solution composition of the present invention.
The fountain solution composition is generally concentrated and commercialized when it is usually commercialized. Therefore, a concentrated solution can be obtained as an aqueous solution in which various components described above are dissolved using water, preferably demineralized water, that is, pure water. When such a concentrated solution is used, it is diluted to about 10 to 200 times, preferably about 30 to 100 times with tap water, well water, etc. during normal use to obtain a fountain solution composition at the time of use.
The present invention is also directed to a fountain solution for lithographic printing in the form of a concentrate. In preparing the concentrate, it is possible to provide dampening water at the time of use in which each component is present at an appropriate concentration by diluting at an appropriate dilution rate so as to prevent precipitation in the concentrate and liquid separation. In addition, an appropriate concentration degree can be selected.
As a composition example of the fountain solution concentrate for lithographic printing according to the present invention, there is a fountain solution concentrate composition containing the star polymer in the range of 0.5 to 10% by mass. As a further specific example, the above star polymer is contained in the range of 0.5 to 10% by mass, and 1 to 80 parts by mass of the compound represented by the general formula (I) with respect to 1 part by mass of the star polymer. 0.5-10 parts by mass of a water-soluble polymer compound other than the star polymer, 0.5-10 parts by mass of at least one selected from organic acids, inorganic acids and salts thereof, and 0.1 of a preservative. -2.0 mass part is contained, the other component is included arbitrarily, and the composition whose remainder is water is mentioned.

The fountain solution composition of the present invention can be used for various lithographic printing plates. In particular, a photosensitive lithographic printing plate having an aluminum plate as a support and a photosensitive layer thereon is subjected to image exposure and development. Thus, it can be suitably used for the lithographic printing plate obtained.
A preferable example of such PS plate is a photosensitive layer comprising a mixture of a diazo resin (a salt of a condensate of p-diazodiphenylamine and paraformaldehyde) and a shellac as described in British Patent 1,350,521. On the aluminum plate, polymers having diazo resin and hydroxyethyl methacrylate unit or hydroxyethyl acrylate unit as main repeating units as described in British Patent Nos. 1,460,978 and 1,505,739 And a photosensitive polymer system containing a dimethylmaleimide group described in JP-A-2-236552 and JP-A-4-274429 was provided on an aluminum plate. A negative PS plate such as the one disclosed in JP-A-50-125806 It includes positive PS plate provided on an aluminum plate and a photosensitive layer comprising a mixture of O- quinonediazide photosensitive material and a novolac-type phenolic resins as described in.
It can also be used for a positive PS plate that has been burned.

In the composition forming the photosensitive layer, an alkali-soluble resin other than the alkali-soluble novolak resin can be blended as necessary.
For example, styrene-acrylic acid copolymer, methyl methacrylate-methacrylic acid copolymer, alkali-soluble polyurethane resin, alkali-soluble vinyl resin described in JP-B-52-28401, alkali-soluble polybutyral resin, and the like. it can.
Further, a PS plate having a photosensitive layer of a photopolymerizable photopolymer composition as described in US Pat. Nos. 4,072,528 and 4,072,527 on an aluminum plate, British Patent Nos. 1,235,281 and A PS plate having a photosensitive layer made of a mixture of an azide and a water-soluble polymer on an aluminum plate as described in each specification of No. 1,495,861 is also preferable.
Furthermore, it can be suitably used for a CTP plate that is directly exposed with a visible or infrared laser. Specific examples include a photopolymer type digital plate (for example, LP-NX manufactured by Fuji Film Co., Ltd.), a thermal positive type digital plate (for example, LH-PI manufactured by Fuji Film Co., Ltd.), printing performed with dampening water and ink. Examples include an on-press developing plate (for example, ET-S manufactured by Fuji Film Co., Ltd.) and a thermal negative type digital plate (for example, LH-NI manufactured by Fuji Film Co., Ltd.).

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to these examples. In the polymer compound, the molecular weight is a mass average molar mass (Mw), and the ratio of repeating units is a mole percentage, except for those specifically defined.

[Examples 1-6 and Comparative Examples 1-2]
[Creation of thermal negative type digital plate]
(Production of support)
0.30 mm thick aluminum plate (Si: 0.09 mass%, Fe: 0.30 mass%, Cu: 0.013 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn : 0.001% by mass, Ti: 0.027% by mass, the balance being aluminum and an inevitable impurity aluminum alloy), the following various surface treatments (a) to (k) were continuously performed.
In addition, after each process and water washing, the liquid was drained with the nip roller.

(A) Mechanical surface roughening treatment While supplying a suspension of a polishing agent (pumice) having a specific gravity of 1.12 and water as a polishing slurry liquid to the surface of the aluminum plate, mechanical roughening is performed by a rotating nylon brush. Surface treatment was performed.
The average particle size of the abrasive was 30 μm, and the maximum particle size was 100 μm.
The material of the nylon brush was 6 · 10 nylon, the hair length was 45 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm.
Three rotating brushes were used. The brush roller was pressed until the load of the drive motor for rotating the brush became 7 kW plus with respect to the load before the brush roller was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The rotation speed of the brush was 200 rpm.

(B) Alkali etching treatment The aluminum plate obtained above was subjected to an etching treatment by spraying using an aqueous solution having a caustic soda concentration of 2.6% by mass, an aluminum ion concentration of 6.5% by mass and a temperature of 70 ° C. / M ² dissolved. Then, water washing by spraying was performed.
(C) Desmutting treatment The desmutting treatment was performed by spraying with a 1% by mass aqueous solution of nitric acid at a temperature of 30 ° C. (containing 0.5% by mass of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut treatment was a waste liquid from a process of performing an electrochemical surface roughening treatment using alternating current in a nitric acid aqueous solution.

(D) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 10.5 g / L aqueous solution of nitric acid (containing 5 g / L of aluminum ions and 0.007% by mass of ammonium ions) at a liquid temperature of 50 ° C. The AC power supply uses electrochemical trapping with carbon electrode as the counter electrode, using a trapezoidal rectangular wave alternating current with a time TP of 0.8 msec until the current value reaches a peak from zero, a duty ratio of 1: 1. It was. Ferrite was used for the auxiliary anode.
The current density was 30 A / dm ² at the peak current value, and the amount of electricity was 220 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode. Then, water washing by spraying was performed.

(E) Alkali etching treatment The aluminum plate was subjected to etching treatment at 32 ° C. using an aqueous solution having a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass to dissolve the aluminum plate by 0.50 g / m ² . Removes the smut component mainly composed of aluminum hydroxide that was generated when electrochemical roughening treatment was performed using the alternating current of the previous stage, and also melted the edge part of the generated pit to smooth the edge part. did. Then, water washing by spraying was performed.
(F) Desmut treatment Desmut treatment was performed by spraying with a 15% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 4.5% by weight of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used in the desmut was the waste liquid from the step of electrochemical surface roughening using alternating current in the nitric acid aqueous solution.

(G) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 5.0 g / L aqueous solution (containing 5 g / L of aluminum ions) at a temperature of 35 ° C. The waveform of the AC power supply is electrochemically roughened using a trapezoidal trapezoidal wave AC with a time TP of 0.8 msec until the current value reaches a peak from zero, a duty ratio of 1: 1, and a trapezoidal trapezoidal wave AC Processed. Ferrite was used for the auxiliary anode. The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 50 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. Then, water washing by spraying was performed.

(H) Alkali etching treatment The aluminum plate was subjected to etching treatment at 32 ° C. using an aqueous solution having a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass%, and the aluminum plate was dissolved at 0.10 g / m ² . Removes the smut component mainly composed of aluminum hydroxide that was generated when electrochemical roughening treatment was performed using the alternating current of the previous stage, and also melted the edge part of the generated pit to smooth the edge part. did. Then, water washing by spraying was performed.
(I) Desmutting treatment A desmutting treatment by spraying was performed with a 25% by weight aqueous solution of sulfuric acid at a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), followed by washing with water by spraying.

(J) Anodizing treatment Anodizing treatment is carried out using an anodizing apparatus (first and second electrolysis section length 6 m, first and second feeding section length 3 m each, first and second feeding electrode section length 2.4 m each). went. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolysis units. All electrolytes had a sulfuric acid concentration of 50 g / L (containing 0.5 mass% of aluminum ions) and a temperature of 20 ° C. Then, water washing by spraying was performed.
(K) Alkali metal silicate treatment The aluminum support obtained by anodizing treatment was immersed in a treatment tank of a 1% by mass aqueous solution of sodium silicate No. 3 at a temperature of 30 ° C. for 10 seconds to immerse the alkali metal silica. Acid salt treatment (silicate treatment) was performed. Thereafter, washing with water using well water was performed to obtain a support subjected to a surface silicate hydrophilization treatment.

When the aluminum plate which performed all the said (a)-(k) process was made into the support body S-1, the centerline average roughness (Ra display by JISB0601) of each support body was measured using the needle | hook of 2 micrometers in diameter. The support S-1 was 0.50 μm.
Next, the following undercoat layer coating solution (A) was applied onto the aluminum support S-1 subjected to the above surface treatment so that the dry coating amount was 10 mg / m ² and dried.

<Undercoat layer coating solution (A)>
Polyvinylphosphonic acid (Mw 20000) 0.017 parts by mass Methanol 9.00 parts by mass Water 1.00 parts by mass

[Formation of photosensitive layer]
The following photosensitive layer coating solution (A) was prepared and applied on the undercoat layer formed as described above using a wire bar to form a photosensitive layer. Drying was performed at 125 ° C. for 34 seconds using a warm air dryer. The coating amount after drying was 1.4 g / m ² .
<Coating solution for photosensitive layer (A)>
Infrared absorber (IR-1) 0.038 parts by mass Polymerization initiator A (S-1) 0.061 parts by mass Polymerization initiator B (I-1) 0.094 parts by mass Mercapto compound (E- 1) 0.015 part by mass-Ethylenically unsaturated compound (M-1) 0.425 part by mass (trade name: A-BPE-4, Shin-Nakamura Chemical Co., Ltd.)
-Binder polymer A (B-1) (Mw: 110,000) 0.311 parts by mass-Binder polymer B (B-2) (Mw: 100,000) 0.250 parts by mass-Binder polymer C (B-3) ( Mw: 120,000) 0.062 parts by mass Additive (T-1) 0.079 parts by mass Polymerization inhibitor (Q-1) 0.0012 parts by mass Ethyl violet (EV-1) 0.021 parts by mass Fluorine-based surfactant 0.0081 parts by mass (Megafac F-780-F DIC Corporation)
Methyl isobutyl ketone (MIBK) 30% by mass solution)
・ Methyl ethyl ketone 5.886 mass parts ・ Methanol 2.733 mass parts ・ 1-methoxy-2-propanol 5.886 mass parts

In addition, the infrared absorber (IR-1), the polymerization initiator A (S-1), the polymerization initiator B (I-1), and the mercapto compound (E-1) used for the photosensitive layer coating solution (A). ), Ethylenically unsaturated compound (M-1), binder polymer A (B-1), binder polymer B (B-2), binder polymer C (B-3), additive (T-1), polymerization prohibited The structures of the agent (Q-1) and ethyl violet (EV-1) are shown below.
In the following, Me represents a methyl group, and the ratio of each monomer unit of the binder polymers A to C below is a molar ratio.

(Formation of lower protective layer)
On the formed photosensitive layer, synthetic mica (Somasif MEB-3L, 3.2 mass% aqueous dispersion, manufactured by Coop Chemical Co., Ltd.), polyvinyl alcohol (Goselan CKS-50, saponification degree 99 mol%, polymerization degree) 300, sulfonic acid-modified polyvinyl alcohol, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), surfactant A (manufactured by Nippon Emulsion Co., Ltd., Emalex 710), and surfactant B (Adeka Pluronic P-84: (stock) ) (Made by ADEKA) was applied with a wire bar and dried at 125 ° C. for 30 seconds with a hot air dryer.
The content ratio of synthetic mica (solid content) / polyvinyl alcohol / surfactant A / surfactant B in the coating solution for forming the lower protective layer is 7.5 / 89/2 / 1.5 (mass%). The coating amount (the coating amount after drying) was 0.5 g / m ² .

[Formation of upper protective layer]
On the lower protective layer, an organic filler (Art Pearl J-7P, manufactured by Negami Industrial Co., Ltd.), synthetic mica (Somasif MEB-3L, 3.2 mass% aqueous dispersion, manufactured by Coop Chemical Co., Ltd.), polyvinyl alcohol (L-3266: Saponification degree 87 mol%, polymerization degree 300, sulfonic acid-modified polyvinyl alcohol, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), thickener (Serogen FS-B, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) A mixed aqueous solution of surfactant (manufactured by Nippon Emulsion Co., Ltd., Emalex 710) is applied with a wire bar and dried at 125 ° C. for 30 seconds with a hot air dryer. I let you.
The content ratio of the organic filler / synthetic mica (solid content) / polyvinyl alcohol / thickener / surfactant in the coating solution for forming the upper protective layer is 3.2 / 2.0 / 80.5 / 11.5. /2.8 (mass%), and the coating amount (the coating amount after drying) was 1.76 g / m ² .

[Formation of back coat layer]
A backcoat layer similar to that of Example 1 of JP-A-6-35174 is provided on the surface of the aluminum support S-1 opposite to the side on which the photosensitive layer and the protective layer are provided, and a negative lithographic printing plate precursor (1 )

[Plate making method]
The obtained lithographic printing plate precursor was processed in the order of each step of exposure, development processing, and plate surface processing.
Light source (setter) used for exposure: Image-like exposure was performed with an infrared semiconductor laser (Trendsetter 3244VX manufactured by Creo, equipped with a water-cooled 40 W infrared semiconductor laser) under conditions of an output of 9 W, an outer drum rotating speed of 210 rpm, and a resolution of 2,400 dpi. It was. As the exposure image, an image in which drawn thin lines having a width of 5 to 100 μm (5 μm intervals) were arranged as the drawn thin line evaluation image was used. For printing durability evaluation, an image capable of solid printing durability evaluation was used.
After the exposure, pre-water washing treatment, development, water washing, and plate surface treatment for removing the overcoat layer were performed using Fujifilm Corporation automatic developing machine LP1310News. As the developer, a 1: 4 water diluted solution of a developer HN-D (former product name: DH-N) manufactured by FUJIFILM Corporation was used. The pH of the developer was 12, and the temperature of the developer bath was 30 ° C.

  Using a Lithron 26 printing machine manufactured by Komori Corporation, Toyo Ink Co., Ltd. ink: Super Leo Echo SOY Black L, Oji Paper Co., Ltd. fine coated paper: OK Topcoat +, and dampening solution composition Printing was performed using the object. The fountain solution composition used is described below.

<Dampening solution composition>
Prescription ingredients of fountain solution composition (use liquid)
Propylene glycol mono-n-butyl ether 0.5 parts by mass Propylene glycol 0.5 parts by mass Various star polymers in Table 7 or comparative B-1 polymer 0.02 parts by mass Carboxymethyl cellulose 0.01 parts by mass Ammonium nitrate 0.05 parts by mass Parts citric acid 0.01 parts by weight malic acid 0.01 parts by weight 2,2-dibromo-2-nitroethanol 0.001 parts by weight benzotriazole 0.002 parts by weight 2-methyl-5-chloro-4-isothiazoline-3 -ON 0.002 parts by mass
Add water to make 100 parts by mass

[Evaluation]
Evaluation-1: <Evaluation of ink removal during printing>
Using the Lithron 26 printing machine manufactured by Komori Corporation for each prepared dampening solution composition, Toyo Ink Co., Ltd. ink: Super Leo Echo SOY Black L, Oji Paper Co., Ltd. fine coating Paper: Printing was performed using OK Topcoat +, and the number of sheets to be printed on the non-image area at the time of printing was recorded (Table I). It can be said that the smaller the number of payments, the better.

Evaluation-2: <Stain prevention evaluation of non-image area (stop dirt prevention evaluation)>
The lithographic printing plate precursor was forcibly aged at 60 ° C. for 4 days, and then exposed and developed by the plate making method to obtain a lithographic printing plate.
This was applied to a printing machine (2N-600, manufactured by Higashihama Seiki Co., Ltd.), and printing was carried out using the additional paper, ink (Soybee Red manufactured by The Inktec Co., Ltd.), and the above fountain solution composition.
When 50,000 sheets of printing paper used for this printing were printed, the printing machine was temporarily stopped, left for 5 hours, and then printing was restarted, and another 200 sheets were printed. The number of sheets until the ink completely disappeared from the non-image area was evaluated (Table II). It can be said that the smaller the number of sheets, the smaller the amount of lost paper from the restart of printing, and the better.

Evaluation-3: <Density reduction evaluation of printed matter due to increase in concentration of all components in dampening water>
The evaluation item is a decrease in density on the printed material when the concentration of all components in the fountain solution composition is increased by 2 times, 3 times, or 4 times. The amount supplied was determined by changing the water scale of the printing press. A solid image of the 500th printed material after determining the water scale when the concentration of all the components is increased by 2 times, 3 times, and 4 times based on the component concentration in the fountain solution composition described above. Was measured using a Macbeth densitometer (Gretag Macbeth: manufactured by GMB).
The index of the printed solid density of x1 was taken as 100, and the printed solid densities of x2, x3 and x4 were expressed (Table III).
Evaluation was performed using a Lithron 26 printing machine manufactured by Komori Corporation, using Toyo Ink Co., Ltd. ink: Super Leo Echo SOY Black L, Oji Paper Co., Ltd. fine coated paper: OK Top Coat + went.

Table I: <Evaluation of ink removal during printing>

Table II: <Evaluation of anti-smudge of non-image area (evaluation of anti-smudge of stop)>

Table III: <Evaluation of decrease in print density due to increase in concentration of all components in fountain solution>

As can be seen from Tables I and II, when the star polymer having a hydrophilic group of the present invention is used, when there is no additive, or a water-soluble polymer having a conventionally known sulfonic acid in the side chain is used. Compared with the case where the printing was performed, it was found that the number of paid sheets was less than half when printing and when resuming printing after stopping for a certain period of time. It can be seen that the fountain solution composition using the star polymer of the invention has improved the occurrence of smudges in the non-image area at the time of printing and after resuming printing. Even when the density was increased to about 4 times, the density of the printed matter was hardly decreased, and an advantageous effect was obtained.

[Examples 7 to 33 and Comparative Examples 3 to 4]
A thermal negative type digital plate was prepared in the same manner as in Example 1 and was subjected to plate making.
Using a Lithron 26 printing machine manufactured by Komori Corporation, Toyo Ink Co., Ltd. ink: Super Leo Echo SOY Black L, Oji Paper Co., Ltd. fine coated paper: OK Topcoat +, and dampening solution composition Printing was performed using the object. The fountain solution composition used is described below.

<Dampening solution composition>
Prescription component of fountain solution composition (use liquid) at the time of use Propylene glycol mono-n-butyl ether 0.5 part by mass Propylene glycol 0.5 part by mass Various star polymers in Tables 8 to 12 or the following comparative PN- 1 Polymer 0.2 parts by mass Carboxymethyl cellulose 0.01 parts by mass Ammonium nitrate 0.05 parts by mass Citric acid 0.01 parts by mass Malic acid 0.01 parts by mass 2,2-Dibromo-2-nitroethanol 0.001 parts by mass Benzo Triazole 0.002 parts by mass 2-Methyl-5-chloro-4-isothiazolin-3-one 0.002 parts by mass Add water to 100 parts by mass

  In the same manner as in Example 1, Evaluation-1 to Evaluation-3 were performed for each fountain solution. The results are shown in Tables IV to VI.

Table IV: <Evaluation of ink removal during printing>

Table V: <Evaluation of anti-smudge property on non-image area (evaluation of anti-smudge of stop)>

Table VI: <Determination of decrease in print density due to increase in concentration of all components in fountain solution>

As can be seen from Tables IV and V, when the star polymer having the hydrophilic group and the support adsorbing group of the present invention is used, when there is no additive, or the conventional phosphate group and sulfonic acid side. Compared to the case of using a polymer having a chain, it was found that the number of payouts was less than half, even when printing was started and when printing was resumed after stopping for a certain period of time. It can be seen that the fountain solution composition using the star polymer of the present invention improves the occurrence of smearing in the non-image area at the start of printing and after resumption of printing.
Further, as apparent from Table VI, even when the fountain solution component concentration was increased to about 4 times, there was almost no decrease in the density of the printed matter, and an advantageous effect was achieved.

Claims (10)

  A fountain solution for lithographic printing comprising a star polymer having at least one hydrophilic group.   The fountain solution composition for lithographic printing according to claim 1, wherein the star polymer is a star polymer having 3 branches or more and 10 branches or less.   The fountain solution composition for lithographic printing according to claim 1 or 2, wherein the star polymer has a polymer chain branched from 3 to 10 branches from the central skeleton via a sulfide bond.   A star polymer is a polymer obtained by polymerizing an ethylenically unsaturated monomer in the presence of a polyfunctional thiol and having a polymer chain branched from 3 to 10 branches from the central skeleton via a sulfide bond. The fountain solution composition for lithographic printing according to claim 3.   The fountain solution composition for lithographic printing according to any one of claims 1 to 4, wherein the star polymer further has at least one support-adsorptive group.   The support adsorbing group of the star polymer is at least one group selected from the group consisting of a phosphonic acid group and a salt thereof, a phosphate ester group and a salt thereof, and a carboxylic acid group and a salt thereof. Item 6. A fountain solution for lithographic printing according to Item 5.   The hydrophilic group of the star polymer is a sulfonic acid group and a salt thereof, an amide group, a polyalkylene oxide group, a hydroxyl group, a sulfate monoester group and a salt thereof, a sulfonamide group, an amino group, a monoamide sulfate and a salt thereof, The fountain solution composition for lithographic printing according to any one of claims 1 to 6, which is at least one group selected from the group consisting of betaine structures.   The fountain solution composition for lithographic printing according to any one of claims 1 to 7, comprising a water-soluble polymer having no star structure.   Water-soluble polymers having no star structure are gum arabic, fibrin derivatives and modified products thereof, polyvinyl alcohol and derivatives thereof, polyvinyl pyrrolidone, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer. Polymer, styrene / maleic anhydride copolymer, water-soluble soybean polysaccharide, starch, starch derivative, pullulan and pullulan derivative, gelatin, and at least one water-soluble substance selected from the group consisting of hemicellulose extracted from soybean The fountain solution for lithographic printing according to claim 8, which is a polymer compound.   The fountain solution composition for lithographic printing according to any one of claims 1 to 9, which is a concentrated fountain solution composition.