JP2011073193A - Dampening water composition for lithographic printing and heat-set-off rotary printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dampening water composition that improves blanket piling, suppresses a pH drop with elapsed time, achieves stable coloring of a coloring agent contained therein without causing discoloring, exerting stable performance. <P>SOLUTION: The dampening water composition for lithographic printing contains at least one kind of antioxidant and at least one kind of diol-based compound selected from 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 1,2-octanediol. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fountain solution composition for lithographic printing, and more specifically to a fountain solution composition for lithographic printing that is preferably used in an offset printing method, particularly in a heat-set-off wheel printing method.

Lithographic printing is a printing method that skillfully uses the property that water and oil do not essentially mix, and the printing plate surface consists of an area that receives water and repels oil-based ink, and an area that repels water and receives oil-based ink. The former is a non-image area, and the latter is an image area. The non-image area is moistened with the fountain solution to increase the interfacial chemical difference between the image area and the non-image area, thereby increasing the ink repellency of the non-image area and the ink receptivity of the image area. Made.
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. At this time, when continuous printing is performed for a long time, a problem of so-called “blanket piling” occurs in which the ink component and the paper component are gradually deposited on the non-image portion on the blanket. In particular, lithographic offset rotary printing (off-wheel printing) is characterized by being capable of continuous operation for a long time and high productivity. However, blanket piling is likely to occur, which is a serious problem.

Blanket piling is easy to deposit as the ink in the image area is pushed out especially on the back side of the rotation (the end of the grip), and the deposit inhibits the ink transfer from the blanket to the paper, causing the ink to deposit poorly. It becomes. In order to remove the deposits, printing must be stopped and the blanket must be cleaned. The increase in waste paper and the reduction in productivity are extremely large, and improvements have been desired.
As a technique for improving blanket piling, a fountain solution for lithographic printing containing a specific diol-based acyclic hydrocarbon compound is disclosed in Patent Documents 1 and 2, and a fountain solution for lithographic printing containing a specific cycloalkane derivative. Patent Document 3 discloses a fountain solution composition for lithographic printing containing a specific triol acyclic hydrocarbon compound. Although each of these techniques has a remarkable effect of improving blanket piling, the pH decreases with time and the colorant added to color the liquid decomposes, so these problems can be improved. It was desired. Since the purpose of coloring the liquid is to make it easy to confirm the remaining amount of the dampening water stock solution in the dampening water container from the outside, it is difficult to confirm the remaining liquid amount when the color is erased.

JP 2009-96177 A JP 2009-96178 A JP 2009-78437 A JP 2009-78438 A

  An object of the present invention is a fountain solution composition that can improve blanket piling, has a suppressed pH drop over time, and is stable in coloration by a colorant without being discolored. It is providing the fountain solution composition which can exhibit performance.

As a result of intensive studies to achieve the above-mentioned problems, the present inventors have added an antioxidant, which is a compound having antioxidant ability, in preparing a fountain solution composition. It was found that the pH decrease with time was suppressed, and the decomposition reaction of the colorant added arbitrarily was suppressed. In particular, by adding the above-mentioned antioxidant to a fountain solution composition using a specific diol-based compound, the pH drop over time is remarkably suppressed, and coloring by the colorant is stable and decolorization is prevented. It was found that the effect of suppressing the occurrence of blanket piling was sufficiently exhibited, and the present invention was completed.
Accordingly, the present invention provides at least one diol compound selected from 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 1,2-octanediol. And a fountain solution for lithographic printing, comprising at least one antioxidant.
As an embodiment of the present invention, there is the above-described fountain solution for lithographic printing, further containing at least one compound represented by the following general formula (III).
R ¹ —O— (CH ₂ CHR ² O) _m —H (III)
(In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms, R ² represents a hydrogen atom or a methyl group, and m represents an integer of 1 to 3).

As an example of the antioxidant, at least one selected from the group consisting of a mercapto group-containing compound, a thioether group-containing compound, a compound having a phosphite structure, a hindered amine compound, and a compound having a hindered phenol skeleton is used. Is mentioned.
A specific example of the antioxidant is a compound having a phenol structure in which at least one of the ortho positions is substituted with a tert-butyl group. As a further specific example, 2,6-di-t-butyl- 4-methylphenol is mentioned.
The present invention is also directed to the lithographic fountain solution composition described above, which is in the form of a fountain solution concentrate composition.
The present invention is also directed to a heatset-off-ring printing method comprising printing using a fountain solution composition obtained by diluting the lithographic fountain solution concentrate composition 10 to 200 times with water. It has been.

According to the fountain solution composition of the present invention, the pH drop over time is suppressed, and the coloring by the colorant is stable and the decolorization is suppressed, so that the performance change over time is extremely small. Stable printing performance can be demonstrated. Since the fountain solution composition of the present invention is stable in coloration by the colorant, it is easy to check the remaining amount of the fountain solution in the fountain solution container from the outside regardless of time, and it is very easy to use. Is.
The problem of pH reduction and decoloration over time is first a problem when the fountain solution composition ages in the state of the fountain solution concentrate composition. According to the present invention, the fountain solution concentrate composition is stored. Even when the printing system is equipped, or even after a lapse of time, the pH can be lowered and the deterioration of coloring can be suppressed, so that the performance can be maintained.
According to the fountain solution composition of the present invention, the occurrence of blanket piling can be suppressed, and good print quality can be stably obtained even after continuous printing for a long time.

The present invention is described in detail below.
〔Antioxidant〕
Examples of the antioxidant included in the fountain solution composition for lithographic printing of the present invention include, for example, a compound containing a mercapto group, a sulfur-containing compound such as a compound containing a thioether group, a hindered amine, a compound having a phosphite structure , Hindered phenols, compounds having a hydroquinone structure, compounds having a chroman structure, compounds having a coumaran structure, compounds having a spiroindane structure, and the like. Also effective are compounds described in JP-A No. 61-159644, hydroxamic acids (such as AI to AV described in JP-A No. 8-76311), and compounds having an epoxy group. .
As an antioxidant to be included in the fountain solution composition of the present invention, in particular, from the group consisting of a mercapto group-containing compound, a thioether group-containing compound, a compound having a phosphite structure, a hindered amine compound, and a compound having a hindered phenol skeleton. At least one selected can be preferably used.

Examples of the mercapto group-containing compound include mercaptoimidazole compounds, and examples thereof include 2-mercaptobenzimidazole and 2-mercaptomethylbenzimidazole.
Examples of the thioether group-containing compound include dilauryl 3,3′-thio-dipropionic acid ester, distearyl 3,3′-thio-dipropionic acid ester, pentaerythrityl tetrakis- [3- (3,5-di -Tert-butyl-4-hydroxyphenyl) -propionate], thiodipropionic acid, phenylthioacetic acid, and the like.
The compound having a phosphite structure means a phosphite compound in which hydrogen of phosphorous acid is substituted with a hydrocarbon group. Examples of such phosphites include triphenyl phosphite, diphenylisodecyl phosphite, phenylisodecyl phosphite, triethyl phosphite, tri-n-propyl phosphite, and phosphorous acid. Examples include trimethyl, dilauryl phosphite, distearyl phosphite, dibutyl phosphite and the like.

  As the hindered amine compound, a compound having a piperidine structure in which the 2,6-position is substituted with a tetraalkyl group is preferable. For example, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2 sebacate) 2,2,6,6-pentamethyl-4-piperidyl), poly [(6-morpholino-S-triazine-2,4-diyl) [2,2,6,6-tetramethyl-4-piperidyl] imino] -Hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino] (for example, trade name CYASORB UV-3346 manufactured by Sun Chemical Co., Ltd.) and the like. Other examples include oligomer-type and polymer-type compounds having a hindered amine structure.

  As the compound having a hindered phenol skeleton, a hindered phenol compound in which at least one of ortho positions of phenol is substituted with an alkyl group having 3 or more carbon atoms is preferably used. Among them, a compound in which at least one of ortho positions of phenol is substituted with a t-butyl group is preferable, and specifically, a compound in which both positions 2 and 6 of phenol are substituted with a t-butyl group is preferable. For example, 2,6-di-t-butyl-4-methylphenol, tetrakis- [methylene-3- (3,5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, 4,4 ′ -Butylidenebis- (6-t-butyl-3-methylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 2,6-butyl-4-nonylphenol 2,6-dibutyl-4-phenylphenol and the like.

As the antioxidant to be used in the present invention, an antioxidant is described, for example, from 102 to 119 of “Market Trend of Polymer Additives” (August 31, 1993) published by CMC Co., Ltd. You can also choose the right compound.
In the fountain solution for lithographic printing according to the present invention, the preferred addition amount of the antioxidant is preferably 1 to 5000 ppm with respect to the total amount of the fountain solution concentrate before dilution to obtain a fountain solution. 10 to 3000 ppm is more preferable. If the addition amount of the antioxidant is too small, the intended effect of the present invention will not be sufficiently exerted, while if it is too much, precipitation will occur, which is not preferable.

The fountain solution composition of the present invention further contains a specific diol compound.
[Specific diol compounds]
In the fountain solution composition of the present invention, a specific diol compound, namely 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-, is used for the purpose of suppressing blanket piling. At least one diol compound selected from propanediol and 1,2-octanediol is added. In particular, the effect intended by the present invention is most noticeable with 2-butyl-2-ethyl-1,3-propanediol.

In the present invention, the addition amount of the diol compound is suitably 0.001 to 2.0 mass%, preferably 0.01 to 1.0 mass%, based on the total amount of the fountain solution composition in use. More preferably, it is 0.05-0.7 mass%, More preferably, it is 0.1-0.5 mass%.
If the amount of diol compound added is too small, the blanket piling suppression effect intended by the present invention cannot be sufficiently obtained. On the other hand, if the amount added is too large, poor dissolution is likely to occur. When a concentrated solution is prepared and diluted to prepare a working solution, precipitation of poorly water-soluble compounds is likely to occur, and uniform and stable use. It becomes difficult to obtain a liquid.

  In the fountain solution composition of the present invention, the diol compound may be used alone or in combination of two or more. As an example of the fountain solution composition of the present invention, two or more diol compounds are contained, and 2-butyl-2-ethyl-1,3-propanediol is 1% by mass or more based on the total mass of the diol compounds. Fountain solution composition. The proportion of 2-butyl-2-ethyl-1,3-propanediol is preferably 3% by mass or more, more preferably 10% by mass or more of the total mass of the diol compound. 2,4-diethyl-1,5-pentanediol as a diol compound used in combination with 2-butyl-2-ethyl-1,3-propanediol in a fountain solution composition containing two or more diol compounds Is particularly mentioned.

（式中、Ｒ³〜Ｒ⁵は各々独立に水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のヒドロキシアルキル基、ヒドロキシル基、ハロゲン原子、メルカプト基、−ＳＯ₃Ｍ¹または−ＣＯＯＭ¹を示す。Ｍ¹は水素原子、アルカリ金属、又はＮＨ₄を示す。）
Ｒ³〜Ｒ⁵は好ましくは、水素原子、メチル基またはエチル基である。一般式（Ｉ）で示される化合物及び一般式（II）で示される化合物うち、一般式（Ｉ）で示される化合物がより好ましく使用される。 The fountain solution composition of the present invention may further contain the following compounds.
[Compound having a benzenesulfonic acid skeleton and a compound having a benzenecarboxylic acid skeleton]
In using the diol compound, a compound having a benzenesulfonic acid skeleton represented by the following general formula (I) and a general formula (II) for the purpose of suppressing precipitation derived from the diol compound: And at least one selected from compounds having a benzenecarboxylic acid skeleton represented by the formula: These compounds are described in detail below.

(In the formula, R ^{3 to} R ⁵ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyl group, a halogen atom, a mercapto group, —SO ₃ M. ¹ or -COOM ^1. M ¹ represents a hydrogen atom, an alkali metal, or NH ₄ .
R ^{3 to} R ⁵ are preferably a hydrogen atom, a methyl group or an ethyl group. Of the compound represented by the general formula (I) and the compound represented by the general formula (II), the compound represented by the general formula (I) is more preferably used.

  Specific examples of the compound represented by the general formula (I) or (II) used in the present invention include benzenesulfonic acid, p-toluenesulfonic acid, cumenesulfonic acid, m-xylenesulfonic acid, p-xylenesulfonic acid, 2,4,6-trimethylsulfonic acid, 4-ethyl-benzenesulfonic acid, phenolsulfonic acid, o-cresolsulfonic acid, m-cresolsulfonic acid, 1,4-benzenedisulfonic acid, 2,5-dimethyl-1, 3-benzenedisulfonic acid, 2,5-dihydroxybenzenesulfonic acid, 4-chlorobenzenesulfonic acid, 4- (hydroxymethyl) benzenesulfonic acid, p-toluenecarboxylic acid, m-xylenecarboxylic acid, benzoic acid, salicylic acid, isophthalyl Sulfonic acid, gallic acid, thiosalicylic acid, sulfosalicylic acid, 4-chlorobenzoic acid, 2, , 5-trichlorobenzoic acid, 2,3,6-trichlorobenzoic acid, 4-methylsalicylic acid, phthalic acid, isophthalic acid, 2,4,6-trimethylbenzoic acid, 2,4,6-trihydroxybenzoic acid, etc. Can be mentioned. Moreover, these alkali metal salts (Na, K, Li salt), ammonium salt, etc. are mentioned. Among these, more preferred are p-toluenesulfonic acid, sodium p-toluenesulfonate, m-xylenesulfonic acid, sodium m-xylenesulfonate, and potassium m-xylenesulfonate, and particularly preferred is m-xylenesulfonic acid, m -Sodium xylene sulfonate and potassium m-xylene sulfonate.

The amount of at least one selected from the compounds represented by the general formula (I) or (II) is suitably 0.01 to 10 times the amount of the diol compound in the fountain solution composition at the time of use. Preferably, it is 0.1-5 mass times, More preferably, it is 0.3-2 mass times.
Even when preparing the fountain solution concentrated composition, at least one added amount selected from the compounds represented by the general formula (I) or (II) is 0. 0% relative to the content of the diol compound. An appropriate amount is 01 to 10 times, preferably 0.1 to 5 times, more preferably 0.3 to 2 times. In the fountain solution concentrated composition, by being in this ratio, it is possible to suppress precipitation originating from the diol-based compound, which is a concern when the fountain solution concentrated composition is diluted to create a working solution, and uniform Thus, it becomes easy to obtain a diluted solution having a stable composition, that is, a fountain solution.

[Alkylene glycol monoether compounds]
The fountain solution composition of the present invention can also contain a compound represented by the following general formula (III).
R ¹ —O— (CH ₂ CHR ² O) _m —H (III)
(In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms, R ² represents a hydrogen atom or a methyl group, and m represents an integer of 1 to 3).
Specifically in the compound of the general formula (III), R ¹ represents a linear or branched alkyl group having 1 to 4 carbon atoms, specifically a methyl group, an ethyl group, a propyl group, Examples include isopropyl group, n-butyl group, isobutyl group, and t-butyl group. From the viewpoint of increasing the solubility of the diol compound and suppressing blanket piling, R ¹ is particularly preferably an n-butyl group, an isobutyl group or a t-butyl group, and most preferably an isobutyl group. M represents an integer of 1 to 3, 1 or 2 is more preferable, and 1 is most preferable.

Specific examples of the compound represented by the general formula (III) include ethylene glycol mono t-butyl ether, ethylene glycol monoisobutyl ether, ethylene glycol mono n-butyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n- Propyl ether, ethylene glycol monoisopropyl ether, diethylene glycol mono t-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol mono n-butyl ether, triethylene glycol mono n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono n-propyl ether, Diethylene glycol monoisopro Ether, propylene glycol mono t-butyl ether, propylene glycol monoisobutyl ether, propylene glycol mono n-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono n-propyl ether, propylene glycol monoisopropyl ether, dipropylene glycol Mono t-butyl ether, dipropylene glycol monoisobutyl ether, dipropylene glycol mono n-butyl ether, tripropylene glycol mono n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono n-propyl ether, Dipropylene glycol monoiso Ropirueteru and the like.
These compounds can be used alone or in combination of two or more.

  Among these, ethylene glycol mono t-butyl ether, ethylene glycol mono isobutyl ether, ethylene glycol mono n-butyl ether, diethylene glycol mono t-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol mono n-butyl ether are more preferable, ethylene glycol monoisobutyl ether, diethylene glycol mono Isobutyl ether and diethylene glycol mono n-butyl ether are particularly preferred, and ethylene glycol monoisobutyl ether can be most preferably used. The addition amount of the compound represented by the general formula (III) is suitably 0.05 to 5.0% by mass with respect to the total mass of the fountain solution composition at the time of use. This is suitable because it has a sufficient effect of suppressing the occurrence of the problem and does not cause problems such as poor printing durability of the roller strip or the printing plate. The addition amount is more preferably 0.1 to 3.0% by mass.

[Compound obtained by adding ethylene oxide and propylene oxide to ethylenediamine or diethylenetriamine]
The fountain solution composition of the present invention can further contain at least one compound selected from a compound obtained by adding ethylene oxide and propylene oxide to ethylenediamine, and a compound obtained by adding ethylene oxide and propylene oxide to diethylenetriamine. . These compounds can be used as an alternative to isopropanol commonly used in fountain solutions.
These compounds are described below.
[Compound obtained by adding ethylene oxide and propylene oxide to ethylenediamine]
The compound obtained by adding ethylene oxide and propylene oxide to ethylenediamine used in the present invention has a weight average molecular weight of 500 to 20000, preferably 500 to 5000, more preferably 800 to 1500, and most suitable is weight. The average molecular weight is around 1000.

In this compound, the ratio of the number of added moles of ethylene oxide and propylene oxide is suitably in the range of 5:95 to 50:50, more preferably 20:80 to 35:65, from the viewpoint of obtaining sufficient printability. It is a range.
As the bond structure of ethylene oxide and propylene oxide, block structure in which ethylene oxide is added first and then propylene oxide is added, block structure in which propylene oxide is added first and then ethylene oxide is added, and at the same time ethylene oxide and propylene There is a random structure to which oxide is added, but the same effect can be obtained with any structure.
The compound obtained by adding ethylene oxide and propylene oxide to ethylenediamine used in the present invention can be produced according to a conventional method. For example, ethylenediamine and / or propylene oxide are reacted with ethylenediamine in the presence of a catalyst.

（式中、Ａ及びＢはそれぞれ独立に−ＣＨ₂ＣＨ₂Ｏ−又は−ＣＨ₂ＣＨ（ＣＨ₃）Ｏ−を表し、Ａ及びＢは互いに異なる基であって、ａ〜ｈは各々０〜５０の整数を表し、但しａ、ｃ、ｅ及びｇのうち少なくとも一つは１以上であり、及びｂ、ｄ、ｆ及びｈのうち少なくとも一つは１以上である。ａ〜ｈは化合物全体の分子量が５００〜２００００となるような値である。なお、各共重合鎖はブロック構造でも、ランダム構造でもよい。）
該化合物の分子量やエチレンオキサイドとプロピレンオキサイドの比率は、例えば水酸基価及びアミン価の測定、ＮＭＲ測定などにより決定することができる。 A compound obtained by adding ethylene oxide and propylene oxide to ethylenediamine used in the present invention is specifically represented by the following formula (IV).

(In the formula, A and B each independently represent —CH ₂ CH ₂ O— or —CH ₂ CH (CH ₃ ) O—, wherein A and B are groups different from each other; Represents an integer of 50, provided that at least one of a, c, e and g is 1 or more, and at least one of b, d, f and h is 1 or more, a to h are the whole compound The molecular weight of the copolymer is 500 to 20000. Each copolymer chain may have a block structure or a random structure.)
The molecular weight of the compound and the ratio of ethylene oxide to propylene oxide can be determined by, for example, measurement of hydroxyl value and amine value, NMR measurement, and the like.

（式中、ａ、ｂ、ｃ、ｄ、ｅ、ｆ、ｇ及びｈはそれぞれ、０〜５０の整数を表し、但しａ、ｃ、ｅ及びｇのうち少なくとも一つは１以上であり、及びｂ、ｄ、ｆ及びｈのうち少なくとも一つは１以上である。） Of the formula (IV), the following formula (IV ′) is more preferable.

(Wherein a, b, c, d, e, f, g and h each represents an integer of 0 to 50, provided that at least one of a, c, e and g is 1 or more, and (At least one of b, d, f, and h is 1 or more.)

The compound represented by the formula (IV ′) has an appropriate weight average molecular weight in the range of 500 to 20000, preferably 500 to 5000, and more preferably 800 to 1500. . a to h are values such that the molecular weight of the whole compound is 500 to 20000, but 1 to 10 are preferable, and 2 to 4 are particularly preferable.
Such a compound does not damage the image area even when water droplets left on the plate when the printing press is stopped evaporates by water and are concentrated and remain. The above compound can also replace isopropyl alcohol without being used in combination with a volatile organic solvent, but tends to worsen blanket piling and water rod contamination. By using together with the diol compound used in the present invention, it becomes possible to replace isopropyl alcohol without deteriorating blanket piling and water rod contamination.
In this compound, the ratio of the number of added moles of ethylene oxide and propylene oxide is suitably in the range of 5:95 to 50:50, more preferably 20:80 to 35:65, from the viewpoint of obtaining sufficient printability. It is a range.

[Compound obtained by adding ethylene oxide and propylene oxide to diethylenetriamine]
The compound obtained by adding ethylene oxide and propylene oxide to diethylenetriamine used in the present invention has an appropriate weight average molecular weight in the range of 500 to 3,000, preferably 800 to 2,000, and most suitable is a weight average molecular weight of around 1000. Is. The above-mentioned compound having such a molecular weight does not damage the image area even when water droplets remaining on the plate when the printing press is stopped are left by evaporation of water and concentration. The above compounds can also replace isopropyl alcohol without using in combination with a volatile organic solvent.

In this compound, the ratio of the number of added moles of ethylene oxide and propylene oxide is suitably in the range of 5:95 to 50:50, more preferably 20:80 to 35:65, from the viewpoint of obtaining sufficient printability. It is a range.
As the bond structure of ethylene oxide and propylene oxide, block structure in which ethylene oxide is added first and then propylene oxide is added, block structure in which propylene oxide is added first and then ethylene oxide is added, and at the same time ethylene oxide and propylene There is a random structure to which oxide is added, but the same effect can be obtained with any structure.
The compound obtained by adding ethylene oxide and propylene oxide to diethylenetriamine used in the present invention can be produced according to a conventional method. For example, it can be produced by reacting diethylenetriamine with ethylene oxide and / or propylene oxide in the presence of a catalyst. Specifically, while cooling diethylenetriamine together with acetonitrile in an ice-water bath, propylene oxide was added dropwise to react therewith, and then ethylene oxide was further added dropwise to react, followed by filtration from this mixture and taking out the precipitate. From this, a propylene oxide / ethylene oxide adduct of diethylenetriamine can be obtained.

（式中、Ａ及びＢはそれぞれ独立に−ＣＨ₂ＣＨ₂Ｏ−又は−ＣＨ₂ＣＨ（ＣＨ₃）Ｏ−を表し、Ａ及びＢは互いに異なる基であって、ａ〜ｊは各々１以上の整数を表す。各共重合鎖はブロック構造でも、ランダム構造でもよい。）
式中、ａ〜ｊは化合物全体の分子量が５００〜３０００となるような値であることが適当であり、１〜６が好ましく、２〜３が特に好ましい。
なお、該化合物の分子量やエチレンオキサイドとプロピレンオキサイドの比率は、例えば水酸基価及びアミン価の測定、ＮＭＲ測定などにより決定することができる。 A compound obtained by adding ethylene oxide and propylene oxide to diethylenetriamine used in the present invention is specifically represented by the following formula (V).

(In the formula, A and B each independently represent —CH ₂ CH ₂ O— or —CH ₂ CH (CH ₃ ) O—, wherein A and B are groups different from each other, and a to j are each 1 or more. (Each copolymer chain may be a block structure or a random structure.)
In the formula, a to j are suitably values such that the molecular weight of the whole compound is 500 to 3000, preferably 1 to 6, and particularly preferably 2 to 3.
The molecular weight of the compound and the ratio of ethylene oxide to propylene oxide can be determined by, for example, measurement of hydroxyl value and amine value, NMR measurement, or 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. Further, after the fountain solution is applied, even if the water droplets remaining on the plate at the time of printing stop are left to evaporate and become concentrated, the image area of the plate is not affected. However, the above compounds tend to worsen blanket piling and water stick dirt, and when used together with the diol compound used in the present invention, isopropyl alcohol can be substituted without worsening blanket piling and water stick dirt. It becomes possible.

[Other additives]
As other components of the fountain solution composition of the present invention, the following can be included.
(a) Aid for improving wettability
(b) Water-soluble polymer compound
(c) pH adjuster
(d) chelating agent
(e) Odor masking agent
(f) ((f-i) antiseptic, (f-ii) colorant, (f-iii) rust inhibitor, (f-iv) antifoaming agent, etc.)

[(A) Aid for improving wettability]
(a) A surfactant or other solvent can be 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, linear alkyl benzene sulfonic acid salts, branched alkyl benzene sulfonic acid. Acid salts, alkylnaphthalene sulfonates, alkylphenoxy polyoxyethylenepropyl sulfonates, polyoxyethylene alkylsulfenyl ether salts, N-methyl-N-oleyl taurine sodium salts, N-alkylsulfosuccinic acid monoamide disodium salts, Petroleum sulfonates, sulfated castor oil, sulfated beef tallow oil, sulfate esters of fatty acid alkyl esters, alkyl sulfate esters, polyoxyethylene alkyl ether sulfate esters, fatty acids Noglyceride sulfates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkylphenyl ether phosphates, styrene -Partially saponified products of maleic anhydride copolymer, partial saponified products of olefin-maleic anhydride copolymer, naphthalene sulfonate formalin condensate 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. In addition, fluorine-based surfactants and silicon-based surfactants can also be used. Of these, polyoxyethylene alkylphenyl ethers, polyoxyethylene-polyoxypropylene block polymers and the like are preferably used. Furthermore, surfactants, such as a silicon derivative or a fluorine derivative, are also mentioned. In the case of using a surfactant, the content thereof is 1.0% by mass or less, preferably 0.001 to 0.5% by mass in the fountain solution composition at the time of use in consideration of foaming. . Two or more kinds can be used in combination.

  In addition, as other auxiliaries or wetting solvents, 3-methoxy-3-methylbutanol, 3-methoxybutanol, ethylene glycol, diethylene glycol, triethylene glycol, butylene glycol, hexylene glycol, glycerin, diglycerin, polyglycerin, triglycerin Methylolpropane or the like can be used. These solvents may be used alone or in combination of two or more. In general, these solvents are suitably used in the range of 0.1 to 3% by mass, preferably 0.3 to 2% by mass, based on the total mass of the fountain solution composition in use.

（式中、Ｒ₄は炭素原子数２〜１２のアルキル基を表す。）
上記ピロリドン誘導体の具体例として、エチルピロリドン、ブチルピロリドン、ペンタピロリドン、ヘキサピロリドン、オクチルピロリドン、ラウリルピロリドンなどが挙げられる。これらの化合物は１種又は２種以上を用いることができる。これらの化合物の中で、式中Ｒ₄が炭素原子数６以上のアルキル基であるものが好ましく、オクチルピロリドンが特に好ましい。上記一般式（VI）で示される化合物は、使用時の湿し水組成物の全質量に基づいて０．０００１〜１．０質量％で用いられるのが適当であり、より好ましくは０．００１〜０．１質量％である。 As another auxiliary agent, a pyrrolidone derivative represented by the following general formula (VI) can be used.

(In the formula, R ₄ represents an alkyl group having 2 to 12 carbon atoms.)
Specific examples of the pyrrolidone derivative include ethyl pyrrolidone, butyl pyrrolidone, pentapyrrolidone, hexapyrrolidone, octyl pyrrolidone, lauryl pyrrolidone and the like. These compounds can be used alone or in combination of two or more. Among these compounds, those in which R ₄ is an alkyl group having 6 or more carbon atoms are preferred, and octylpyrrolidone is particularly preferred. The compound represented by the general formula (VI) is suitably used in an amount of 0.0001 to 1.0% by mass, more preferably 0.001 based on the total mass of the fountain solution composition in use. It is -0.1 mass%.

  The fountain solution composition of the present invention may also contain at least one compound selected from acetylene glycols, acetylene alcohols, and ethylene oxide and / or propylene oxide adducts thereof. Specific examples of these compounds include 3,5-dimethyl-1-hexyne-3-ol, 2,5-dimethyl-3-hexyne-2,5-diol, and 2,4,7,9-tetramethyl-5. Decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 2-butyne-1,4-diol, 3-methyl-1-butyn-3-ol, and their Examples include ethylene oxide and / or propylene oxide adducts. Among them, 3,6-dimethyl-4-octyne-3,6-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,4,7,9-tetramethyl-5 Preferred is a compound in which 4 to 10 ethylene oxides of decyne-4,7-diol are added. 0.0001-1.0 mass% is suitable for the addition amount of these compounds based on the total mass of the fountain solution composition at the time of use, Preferably it is 0.001-0.1 mass%.

The fountain solution composition of the present invention also includes the following compounds as necessary for adjusting the dynamic surface tension, solubilizing, or controlling the mixing rate (emulsification rate) of the printing ink within an appropriate range. Can be added: 2-ethyl-1,3-hexanediol, ethylene oxide and / or propylene oxide adduct of 2-ethyl-1,3-hexanediol, propylene oxide adduct of trimethylolpropane, glycerin Propylene oxide adducts, sorbitol propylene oxide adducts, tetrahydrofurfuryl alcohol and the like.
Among these, 2-ethyl-1,3-hexanediol is preferable as a dynamic surface tension auxiliary agent, and tetrahydrofurfuryl alcohol is preferable as a solubilizing agent. As the ink emulsification control agent, an ethylene oxide adduct of 2-ethyl-1,3-hexanediol, a propylene oxide adduct of trimethylolpropane, or the like can be preferably used. These compounds can be used alone or in combination of two or more. These compounds are suitably used in an amount of 0.01 to 7% by mass, more preferably 0.05 to 5% by mass, based on the total mass of the fountain solution composition in use.

[(B) Water-soluble polymer compound]
Examples of the water-soluble polymer compound (b) used in the fountain solution composition of the present invention include gum arabic, starch derivatives (eg, dextrin, enzymatically degraded dextrin, hydroxypropylated enzymatically degraded dextrin, carboxymethylated starch, phosphorus Acid starch, octenyl succinylated starch), alginate, fibrin derivatives (for example, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose) and other natural products and their modified products, polyethylene glycol and co-polymers thereof Polymer, polyvinyl alcohol and its derivatives, polyvinyl pyrrolidone, polyacrylamide and its copolymer, polyacrylic acid and its copolymer, vinyl methyl ether / maleic anhydride Phosphate copolymer, vinyl acetate / maleic anhydride copolymer include a composite of polystyrene sulfonic acid and copolymers thereof. The content of the water-soluble polymer compound is suitably 0.0001 to 0.1% by mass, more preferably 0.0005 to 0.05% by mass with respect to the fountain solution composition in use. .

In the present invention, among the above water-soluble polymer compounds, polyvinyl pyrrolidone, hydroxypropyl cellulose, and hydroxypropyl methylcellulose can be particularly preferably used. The polyvinylpyrrolidone contained in the fountain solution composition means a homopolymer of vinylpyrrolidone. Polyvinylpyrrolidone having a molecular weight of 200 to 3,000,000 is appropriate, preferably having a molecular weight of 300 to 500,000, more preferably 300 to 100,000. Particularly preferred is 300 to 30,000.
These polyvinyl pyrrolidones can be used alone or in combination of two or more kinds having different molecular weights. Further, it can be combined with a low molecular weight polyvinyl pyrrolidone, for example, a vinyl pyrrolidone oligomer having a polymerization degree of 3 to 5.
As such polyvinyl pyrrolidone, a commercially available product can be used. For example, various great grades such as K-15, K-30, K-60, K-90, K-120 manufactured by ISP can be used.
0.001-0.3 mass% is suitable for content of polyvinylpyrrolidone in the fountain solution composition at the time of use, Preferably it is 0.005-0.2 mass%.

The fountain solution composition of the present invention preferably contains at least one selected from saccharides. The sugar to be used can be selected from monosaccharides, disaccharides, oligosaccharides, and the like, and includes sugar alcohols obtained by hydrogenation. Specific examples 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-alto-3-heptulose, saccharose, lactose, D -Maltose, isomaltose, inulobiose, hyalbiouron, maltotriose, D, L-arabit, rebit, xylit, D, L-sorbit, D, L-mannit, D, L-digit, D, L-talit, zulcit , Allozulcit, maltitol, reduced water candy, etc. It is. These saccharides may be used alone or in combination of two or more.
In the fountain solution composition at the time of use, the content of at least one selected from saccharides is suitably 0.01 to 1% by mass, preferably 0.1 to 0.8% by mass.

((C) pH adjuster)
As the (c) pH adjusting agent used in the fountain solution composition of the present invention, a water-soluble organic acid and / or inorganic acid or a salt thereof can be used, and these compounds are used for adjusting the pH of the fountain solution or adjusting the pH. It is effective for buffering, moderate etching of the lithographic printing plate support or anticorrosion. Preferred organic acids include, for example, citric acid, succinic acid, malic acid, tartaric acid, lactic acid, acetic acid, gluconic acid, acetic acid, hydroxyacetic acid, succinic acid, malonic acid, levulinic acid, sulfanilic acid, p-toluenesulfonic acid, phytic acid, And organic phosphonic acid. Examples of the inorganic acid include phosphoric acid, nitric acid, sulfuric acid, and polyphosphoric acid. Further, alkali metal salts, alkaline earth metal salts or ammonium salts of these organic acids and / or inorganic acids, and organic amine salts are also preferably used. These organic acids, inorganic acids and / or salts thereof can be used alone. Or you may use as a mixture of 2 or more types. The addition amount of these pH adjusters to the fountain solution composition of the present invention is preferably in the range of 0.001 to 0.3% by mass, and in the acidic region where the pH value of the fountain solution composition is in the range of 3 to 7. Although it is preferable to use it, it can also be used in an alkaline region having a pH of 7 to 11 containing alkali metal hydroxide, phosphoric acid, alkali metal salt, alkali metal carbonate, silicate and the like.

((D) chelating agent)
(D) a chelating agent can be further added to the fountain solution composition of the present invention. The fountain solution composition is usually prepared by diluting the concentrated solution by adding tap water or well water at the time of use. At this time, calcium ions contained in the diluted tap water or well water adversely affect printing. And may cause the printed material to become dirty easily. In such a case, the above disadvantages can be eliminated by adding a chelating agent. Preferred chelating agents include, for example, ethylenediaminetetraacetic acid, its potassium salt, its sodium salt; diethylenetriaminepentaacetic acid, its potassium salt, sodium salt; triethylenetetraminehexaacetic acid, its potassium salt, its sodium salt, hydroxyethylethylenediaminetriacetic acid Nitrilotriacetic acid, sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, potassium salt, sodium salt; aminotri (methylenephosphonic acid), potassium salt, sodium salt And organic phosphonic acids and 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%.

((E) Odor masking agent)
(e) Odor masking agents include esters that are conventionally known for use as perfumes. For example, there is one represented by the following general formula (VII).
R ² -COOR ³ (VII)
In the compound of general formula (VII), R ² is an alkyl group having 1 to 15 carbon atoms, an alkenyl group, an aralkyl group, or a phenyl group. In the case of an alkyl group or an alkenyl group, the number of carbon atoms is preferably 4-8. When R ² represents an alkyl group, an alkenyl group or an aralkyl group, they may be linear or branched. An alkenyl group having one double bond is particularly suitable. Examples of the aralkyl group include a benzyl group and a phenylethyl group. One or more hydrogen atoms of the alkyl group, alkenyl group, aralkyl group or phenyl group represented by R ² may be substituted with a hydroxyl group or an acetyl group. R ³ is an alkyl group having 3 to 10 carbon atoms, an aralkyl group or a phenyl group, which may be linear or branched. In the case of an alkyl group, the number of carbon atoms is preferably 3 to 9. Examples of the aralkyl group include a benzyl group and a phenylethyl group.

  Specific examples of (e) odor masking agents that can be used include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, 2-ethylbutyric acid, valeric acid, isovaleric acid, 2-methylvaleric acid, hexanoic acid (caproic acid), 4-methylpentanoic acid (isohexanoic acid), 2-hexenoic acid, 4-pentenoic acid, heptanoic acid, 2-methylheptanoic acid, octanoic acid (caprylic acid), nonanoic acid, decanoic acid (capric acid), 2-decenoic acid , Esters of lauric acid or myristic acid. In addition, there are acetoacetate esters such as benzyl phenylacetate, ethyl acetoacetate and 2-hexyl acetoacetate. 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 content of these acid esters in the fountain solution composition is suitably from 0.0001 to 10% by mass, more preferably from 0.001 to 1% by mass, based on the total mass of the fountain solution composition in use. %. By using these, the work environment can be further improved. Also. Vanillin, ethyl vanillin or the like may be used in combination.

  Examples of the (fi) preservative used in the fountain solution composition of the present invention include phenol or a derivative thereof, formalin, imidazole derivative, sodium dehydroacetate, 4-isothiazolin-3-one derivative, benztriazole derivative, amidine or guanidine. Derivatives, quaternary ammonium salts, pyridine, quinoline or guanidine derivatives, diazine or triazole derivatives, oxazole or oxazine derivatives, bromonitroalcohol-based bromonitropropanol, 2,2-dibromo-2-nitroethanol, 3-bromo -3-nitropentane-2,4-diol and the like. A preferable addition amount is an amount that exerts a stable effect on bacteria, fungi, yeast, etc., and varies depending on the type of bacteria, fungi, yeast, etc., but is 0. The range of 001 to 1.0% by mass is preferable, and it is preferable to use two or more preservatives that are effective against various molds, bacteria, and yeasts.

As the colorant (f-ii) used in the present invention, food colorants and the like can be preferably used. For example, CI No. 19140, 15985 as a yellow dye, CI No. 16185, 45430, 16255, 45380, 45100 as a red dye, CI No. 42640 as a purple dye, CI No. 42090, 73015 as a blue dye, CI No. 42095, and the like.
Examples of the (f-iii) rust preventive include benzotriazole, 5-methylbenzotriazole, thiosalicylic acid, benzimidazole and derivatives thereof. Can be used in the present invention.
(f-iv) As the antifoaming agent, 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. It is preferable from the viewpoints of transportation cost, storage space, manufacturing cost including packaging materials, and the like to appropriately dilute such a concentrated solution (concentrated composition) to prepare a fountain solution composition at the time of use. Therefore, the concentrated composition can be obtained as an aqueous solution in which various components described above are dissolved using water, preferably demineralized water, that is, pure water. The dilution ratio is preferably 10 to 200 times, more preferably 20 to 150 times, particularly preferably 30 to 100 times, and the concentration in the concentrated solution is adjusted so that the concentration becomes the concentration of the fountain solution at the time of use. Set. The higher the concentration rate, the better from the viewpoint of cost. However, if the concentration rate is too high, problems such as precipitation in the concentrated liquid and liquid separation are not preferable.

The present invention is also directed to a fountain solution composition for lithographic printing, which is in the form of a fountain solution concentrate composition containing the various components described above.
One embodiment of the fountain solution concentrate for lithographic printing includes 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 1,2- 5 to 25% by mass of at least one diol compound selected from octanediol, 1 to 5000 ppm of antioxidant, and 5 to 70% by mass of at least one compound represented by formula (III) The fountain solution concentration composition contained in
Other embodiments of lithographic fountain solution concentrate compositions include 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 1,2-octane. 5 to 25% by mass of at least one diol compound selected from diols, 1 to 5000 ppm of an antioxidant, 5 to 70% by mass of at least one compound represented by the general formula (III), and coloring A fountain solution concentrated composition containing the agent in the range of 0.00001 to 0.001% by mass is included.
Still other embodiments of the fountain solution concentrate for lithographic printing include 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 1,2- 5 to 25% by mass of at least one diol compound selected from octanediol, 1 to 5000 ppm of an antioxidant, and at least one compound represented by the above general formula (I) or (II) 0.3 to 2 times by mass with respect to the compound, 5 to 70% by mass of the compound represented by the general formula (III), and 0.00001 to 0.001% by mass of the colorant And a fountain solution concentrated composition.

  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 (previously photosensitive). The applied printing plate is called a PS plate) and can be suitably used for a lithographic printing plate obtained by image exposure and development. 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, the fountain solution composition of the present invention can also 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 development type 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.).

[Examples 1-8 and Comparative Examples 1-11]
According to the formulation of the following fountain solution composition, various fountain solution concentrates shown in Table 1 were prepared in exactly the same manner except that the types of diol compounds and antioxidants were changed as shown in Table 1 below. did.

Prescription component of fountain solution composition (concentrated liquid) Addition amount Ethylene glycol monoisobutyl ether 200 g
Ethylene glycol monotertiary butyl ether 200g
120 g of diol compounds in Table 1
70 g of sodium m-xylene sulfonate
Antioxidant 1g
30g ammonium nitrate
Citric acid 8g
Hydroxypropylcellulose 5g
N-octylpyrrolidone 10g
Tartrazine 0.0004g
Add water to 1000g with KOH (48%) pH 4.0

  After aging at 45 ° C. for 2 weeks with respect to various fountain solution concentrates, the pH variation is measured and the color change is visually evaluated as follows, and then 2% in the fountain solution tank. As described above, printing was performed after diluting with water, and the following evaluation was performed. The printing machine uses Lithron26 manufactured by Komori Corporation, ink of Toyo Ink Co., Ltd .: Leo X Ink L, fine coated paper of Oji Paper Co., Ltd .: OK Top Coat +, Fuji Film Co., Ltd. Plate: After printing 20000 sheets with PN-V, blanket piling was evaluated as follows.

(1) pH fluctuation The pH immediately after the preparation and the pH after aging at 45 ° C. for 4 weeks were measured, and the difference between them was determined as the pH fluctuation. The larger the value, the greater the pH variation, which is not preferable.
pH fluctuation = (pH value immediately after preparation) − (pH value after aging at 45 ° C. for 4 weeks)
(2) Color change A sample stored in a refrigerator and a sample aged for 4 weeks at 45 ° C. were visually compared, and sensory evaluation was performed as follows.
○: Almost no difference △: Slightly light color but no problem ×: Clearly light color XX: Almost no color over time (3) Blanket piling evaluation End of printing Then, the blanket was removed, and the height of the deposit on the non-image area was measured with a stylus type surface roughness meter (surf coder), and an experiment with a diol compound-free fountain solution (Table 1 Evaluation was made based on relative values when Comparative Example 1) was 100. A smaller value indicates a lower height of the pile.

In Table 1, the symbols described represent the following compounds.
Diol compound (1) 2,4-diethyl-1,5-pentanediol (2) 2-butyl-2-ethyl-1,3-propanediol (3) 1,2-octanediol comparative compound (4) 2-ethyl-1,3-hexanediol comparative compound (5) 1,8-octanediol comparative compound (6) 1,9-nonanediol / antioxidant (A) 2,6-di-t-butyl-4 -Methylphenol (BHT)
(B) 2,6-dibutyl-4-phenylphenol (C) Tominox TT (manufactured by Tomen Chemical Co., Ltd., tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxy) Phenyl) propionate] methane)
(D) Dilauryl thiodipropionate (E) 2-mercaptomethylbenzimidazole (F) Sanol LS-770 (manufactured by Sankyo Lifetech Co., Ltd.)

  From the results shown in Table 1, it was found that the pH change and the color change with time were remarkably suppressed by adding the antioxidant according to the present invention. In addition, as can be seen by comparing Examples 1 to 3 and Comparative Examples 1 to 4, by using the diol compound according to the present invention, not only blanket piling can be suppressed, but also pH fluctuation with time can be further suppressed. And variations in color are also suppressed.

[Examples 9 to 12]
In the formulation of the fountain solution composition of Example 2, various fountain solutions shown in Table 2 were used in exactly the same manner except that ethylene glycol monoisobutyl ether was changed in an equal mass to another organic solvent as shown in Table 2 below. A concentrated solution was prepared. Thereafter, an experiment was performed in the same manner as described above, and the results obtained are shown in Table 2.

  From the results in Table 2, it was found that the use of ethylene glycol monoisobutyl ether further increases the desired effect of the present invention, which is preferable.

In Example 6, a printing experiment was performed in the same manner except that the ink used in the printing experiment was changed as follows, and the effect of the fountain solution composition of the present invention was confirmed.
Toyo Ink Co., Ltd. Leo X Indigo, Red, Yellow Tokyo Ink Co., Ltd. Web Actus SOY Major Ink, Indigo, Red, Yellow DIC Corporation New Advan Ink, Indigo, Red, Yellow The Ink Tech Co., Ltd. SOYBI VISTA ink, indigo, red, yellow The same results as in Example 6 were observed for all of the above heat set type off-wheel inks.
The ink in printing in which the fountain solution composition of the present invention is used is not limited to these. The fountain solution composition of the present invention is also useful for printing using fluorescent ink, matte ink, various intermediate color inks, and the like.

Claims (7)

  At least one diol compound selected from 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 1,2-octanediol, and at least 1 A fountain solution composition for lithographic printing, comprising a kind of antioxidant. The fountain solution composition for lithographic printing according to claim 1, further comprising at least one compound represented by the following general formula (III).
R ¹ —O— (CH ₂ CHR ² O) _m —H (III)
(In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms, R ² represents a hydrogen atom or a methyl group, and m represents an integer of 1 to 3).   The antioxidant is at least one selected from the group consisting of a mercapto group-containing compound, a thioether group-containing compound, a compound having a phosphite structure, a hindered amine compound, and a compound having a hindered phenol skeleton. 2. A fountain solution for lithographic printing according to 2.   The fountain solution composition for lithographic printing according to claim 3, wherein the antioxidant is a compound having a hindered phenol structure in which at least one of the ortho positions is substituted with a tert-butyl group.   The fountain solution composition for lithographic printing according to claim 4, wherein the antioxidant is 2,6-di-t-butyl-4-methylphenol.   The fountain solution composition for lithographic printing according to any one of claims 1 to 5, which is in the form of a fountain solution concentrate composition.   A printing method using a dampening solution obtained by diluting the fountain solution composition for lithographic printing according to claim 6 10 to 200 times with water.