Concentrated dampening water composition, dampening water composition, method of producing printed matter using the same, and printed matter

Abstract

To provide a concentrated dampening water composition that even if a time in a state of a concentrated dampening water composition elapses, can exert sufficient antiseptic property when diluted to turn into a dampening water.SOLUTION: A content of a hydroxyl carboxylic acid and / or a salt thereof in a concentrated dampening composition needs to be less than 0.3 mass% when the concentrated dampening water composition contains a compound having an isothiazolinone skeleton as an antiseptic agent of a dampening water. If a content of a hydroxyl carboxylic acid and / or a salt thereof is 0.3 mass% or more, a compound having an isothiazolinone skeleton decomposes to materially reduce antiseptic properties.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a concentrated dampening water composition, a dampening water composition, a method for producing a printed matter using the same, and a printed matter.

[0002] Offset printing is a printing method that utilizes the water-repellent property of an oil-based ink composition for offset printing (hereinafter, abbreviated as "ink composition" or "ink"), and is characterized by using a printing plate without unevenness, unlike letterpress printing, which uses a printing plate with unevenness. This printing plate has lipophilic image areas and hydrophilic non-image areas instead of unevenness. During printing, the non-image areas of the printing plate are first moistened with dampening water to form a water film on the surface, and then the ink composition is supplied to the printing plate. At this time, the supplied ink composition repels and does not adhere to the non-image areas with the water film formed, but adheres only to the lipophilic image areas. In this way, an image is formed by the ink composition on the surface of the printing plate, and then it is transferred to the blanket and paper in sequence to perform printing.

[0003] The simplest composition of the dampening water used in this case may be water alone, but water alone often does not fully satisfy the functions required of dampening water. For example, if the amount of dampening water supplied is not appropriate, the ink composition is not transferred sufficiently to the image area, resulting in a decrease in image density, or the ink composition adheres to the non-image area, causing printing stains, which causes printing problems. However, if the dampening water is composed of only water, the range of the appropriate supply amount is narrow (this is the so-called "narrow water width" state), and it becomes difficult to obtain good printed matter even if the printing conditions change slightly. Therefore, it is common to adjust the viscosity, surface tension, pH, emulsification properties of the dampening water against the ink composition, etc., of the dampening water by blending various additives such as acids, bases and their salts, surfactants, and wettable water-soluble resins, thereby expanding the range of the appropriate supply amount of the dampening water. Incidentally, dampening water used in printing is usually sold and distributed in a concentrated state, and printing companies, which are consumers, generally prepare dampening water by diluting such concentrated dampening water composition with tap water, ion-exchanged water, etc., and use it for printing. Such concentrated dampening solution compositions are also called H liquid (etchant).

[0004] Meanwhile, in recent years, neutral dampening water has been widely adopted, especially in the field of newspaper printing. Up until now, acidic or alkaline dampening water has been adopted as dampening water for offset printing from the viewpoint of improving the surface uniformity of the dampening water, and alkaline dampening water has been widely used in the field of newspaper printing. However, alkaline dampening water does not meet the wastewater standards when it is disposed of after use, and it is necessary to neutralize the dampening water before disposal. In this background, the adoption of neutral dampening water is spreading in the field of newspaper printing as described above (see, for example, Patent Document 1). However, as described above, the dampening water is made acidic or alkaline in order to improve the surface uniformity, so that making the dampening water neutral may cause a problem that the surface uniformity is reduced. In this regard, a method of adding salts such as sodium malate to neutral dampening water to improve the surface uniformity has been used (see, for example, Patent Documents 1 to 3).

[0005] In addition, when a neutral dampening water is used, unlike when an acidic or alkaline dampening water is used, there is a problem that microorganisms such as bacteria and fungi are likely to grow in the dampening water. If such microorganisms grow in the dampening water, slime and mold will be generated in the tank or pipes for circulating the dampening water, leading to problems such as printing defects and putrid odors. In order to suppress such problems, preservatives such as methylisothiazolinone and chloromethylisothiazolinone are added to neutral dampening water compositions in particular.

[0006] In the present invention, "offset printing" refers to planographic printing using a printing plate having no unevenness and having lipophilic image areas and hydrophilic non-image areas as described above. In this specification, the dampening water is referred to as "fountain solution" or "fountain solution composition" depending on the context, but both have the same meaning. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2010-120302 A [Patent Document 2] JP 2007-021806 A [Patent Document 3] JP 2008-006694 A Summary of the Invention [Problem to be solved by the invention]

[0008] As described above, in particular in the case of neutral dampening water, in order to compensate for the surface smoothing and antiseptic properties that tend to be insufficient, surface smoothing agents such as sodium malate and isothiazolinone-based preservatives are used, and the surface smoothing and antiseptic properties are raised to a practical level. Meanwhile, dampening water is generally in the form of a concentrated dampening water composition when it is distributed in the market as described above or stored as a consumer's inventory. Then, when a consumer prints, the consumer prepares dampening water of a predetermined concentration by diluting the concentrated dampening water composition with tap water or ion-exchanged water. However, when a product that has been distributed and stored in the form of such a concentrated dampening water composition for a while is diluted and used as dampening water, there have been occasional cases where the product causes putrefaction in the tank or piping for circulating the dampening water, that is, the added preservative becomes ineffective.

[0009] The present invention has been made in consideration of the above circumstances, and has an object to provide a concentrated dampening water composition which can exhibit sufficient antiseptic properties when diluted to form dampening water, even if time has passed in this state. [Means for solving the problem]

[0010] The present inventors have conducted extensive research to solve the above problems, and have found that in a concentrated fountain solution composition containing a compound having an isothiazolinone skeleton as a preservative, when a hydroxycarboxylic acid compound such as sodium citrate or sodium malate is present, the compound having an isothiazolinone skeleton is altered, causing a significant decrease in preservative properties. The present inventors have also found that this alteration occurs significantly when the concentration of the hydroxycarboxylic acid compound in the concentrated fountain solution composition is 0.3% by mass or more. The present invention has been completed based on these findings, and provides the following:

[0011] (1) The present invention is a concentrated fountain solution composition containing a compound having an isothiazolinone skeleton, characterized in that the content of a hydroxycarboxylic acid and / or a salt thereof is 0.05 mass% or more and less than 0.3 mass%.

[0012] (2) The present invention also relates to a concentrated dampening water composition according to the above (1), wherein the hydroxycarboxylic acid is malic acid and / or citric acid.

[0013] (3) The present invention also relates to a concentrated dampening water composition according to the above item (1) or (2), in which the hydroxycarboxylic acid and / or its salt is sodium malate and / or sodium citrate.

[0014] (4) The present invention also relates to a concentrated dampening water composition according to any one of (1) to (3), in which the hydroxycarboxylic acid and / or a salt thereof is sodium malate.

[0015] (5) The present invention also relates to a concentrated dampening water composition according to any one of (1) to (4), wherein the compound having an isothiazolinone skeleton is selected from the group consisting of 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 2-octyl-4-isothiazolin-3-one, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one and 1,2-benzisothiazolin-3-one.

[0016] (6) The present invention also relates to the concentrated dampening water composition according to any one of (1) to (5), in which the compound having an isothiazolinone skeleton is 2-methyl-4-isothiazolin-3-one.

[0017] (7) The present invention also relates to a concentrated dampening water composition according to any one of (1) to (6), wherein the content of the hydroxycarboxylic acid and / or its salt is from 0.05% by mass to 0.2% by mass.

[0018] (8) The present invention also relates to a dampening water composition which is a dilution of the concentrated dampening water composition according to any one of items (1) to (7).

[0019] (9) The present invention also relates to a dampening water composition which is a dilution of the concentrated dampening water composition according to any one of (1) to (7) above, and has a pH of more than 5 and less than 9.

[0020] (10) The present invention also relates to a method for producing a printed matter, which comprises carrying out printing using the dampening water composition according to (8) or (9).

[0021] (11) The present invention also relates to a printed matter, in which an image is formed on a paper medium using an ink composition, and the paper medium contains the components of the dampening water composition described in (8) or (9) except for water. Effect of the Invention

[0022] According to the present invention, there is provided a concentrated dampening water composition which, even if time has passed in the form of the concentrated dampening water composition, can exhibit sufficient antiseptic properties when diluted to form dampening water. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] An embodiment of a concentrated dampening water composition, an embodiment of a dampening water composition, an embodiment of a method for producing a printed matter, and an embodiment of a printed matter of the present invention will be described below. Note that the present invention is not limited to the following embodiments and aspects, and can be practiced with appropriate modifications within the scope of the present invention.

[0024] <Concentrated fountain solution composition> First, one embodiment of the concentrated dampening water composition of the present invention will be described. The concentrated dampening water composition of the present invention is a concentrated dampening water composition containing a compound having an isothiazolinone skeleton, and is characterized in that the content of hydroxycarboxylic acid and / or its salt is less than 0.3 mass %. The concentrated dampening water composition of the present invention may also contain various other components used in concentrated dampening water compositions. Each component will be described below.

[0025] The concentrated dampening water composition of the present invention contains a compound having an isothiazolinone skeleton. The compound having an isothiazolinone skeleton is added to the concentrated dampening water composition of the present invention as a preservative, and when the concentrated dampening water composition is diluted and used for printing as dampening water, the compound suppresses the decay and slime generation associated with the proliferation of bacteria and fungi in the dampening water. The compound having an isothiazolinone skeleton is a compound having a skeleton represented by the following chemical formula (1) and having various substituents on the skeleton. The following isothiazolinone skeleton may be condensed with a ring structure such as an aromatic ring to form a condensed ring. Compounds having an isothiazolinone skeleton having such a condensed ring are also included in the compounds having an isothiazolinone skeleton of the present invention. This type of compound is widely used as a bactericide, antifungal agent, preservative, etc., as a preservative for shampoo, cosmetics, glue, various industrial products, etc., and as a disinfectant for coolants, etc., and these compounds can be used without any particular restrictions in the present invention.

[0026] [ka]

[0027] Examples of compounds having an isothiazolinone skeleton include 2-methyl-4-isothiazolin-3-one (MIT; chemical formula (A) below), 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT; chemical formula (B) below), 2-octyl-4-isothiazolin-3-one (OIT; chemical formula (C) below), 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT; chemical formula (D) below), and 1,2-benzoisothiazolin-3-one (BIT; chemical formula (E) below). Among these, MIT is preferred.

[0028] [ka]

[0029] The concentration of the compound having an isothiazolinone skeleton in the concentrated fountain solution composition is preferably about 0.01 to 6 mass%, more preferably about 0.05 to 5 mass%, and even more preferably about 0.1 to 4 mass%.

[0030] As described above, in a concentrated dampening water composition containing a compound having an isothiazolinone skeleton as a preservative, the preservative property may be inactivated in some cases, and when such a concentrated dampening water composition is diluted and used as dampening water, the dampening water may decay or slime may be generated in the dampening water supply system at the printing site. According to the study by the present inventor, it has become clear that such preservative inactivation occurs significantly when a hydroxycarboxylic acid or a salt thereof is coexisted as a component of the concentrated dampening water composition. The mechanism of such inactivation is not necessarily clear, but it is generally presumed to be as follows. That is, a compound having an isothiazolinone skeleton is said to exhibit a bactericidal effect against bacteria and fungi due to its oxidizing action, and on the other hand, it can be said that it is easily affected by compounds related to oxidation and reduction. Hydroxycarboxylic acid and its salt have a substituent related to oxidation and reduction, such as a hydroxy group or a carboxy group, and it is considered that they may have some effect on a compound having an isothiazolinone skeleton in some cases. One of such possibilities is that the hydroxy group of hydroxycarboxylic acid is oxidized by an isothiazolinone compound having an oxidizing effect and converted to a keto group, and the isothiazolinone compound itself is reduced and converted to some decomposition product, or some other chemical change occurs.In fact, when a compound having an isothiazolinone skeleton and a hydroxycarboxylic acid or its salt are allowed to coexist in a concentrated dampening water composition, the concentrated dampening water composition is colored yellow to brown over time and loses its antiseptic properties, but if the hydroxycarboxylic acid or its salt is not allowed to coexist, such coloring is not observed and the antiseptic properties are not lost.From these points, it is reasonable to consider that the above coloring occurs with the deterioration of a compound having an isothiazolinone skeleton.

[0031] The present invention was made based on the above findings, and is characterized in that the amount of hydroxycarboxylic acid and / or its salt added is suppressed in a concentrated dampening water composition using a compound having an isothiazolinone skeleton as a preservative. In this regard, according to the study by the present inventor, it has become clear that the above-mentioned deactivation can be suppressed if the content of hydroxycarboxylic acid and / or its salt in the concentrated dampening water composition is less than 0.3 mass%. For this reason, the content of hydroxycarboxylic acid and / or its salt in the concentrated dampening water composition of the present invention is less than 0.3 mass%. In addition, this content is preferably 0.2 mass% or less. It is also true that hydroxycarboxylic acid and its salt provide good surface-leveling effect to dampening water. Therefore, in the present invention, hydroxycarboxylic acid and / or its salt are used in an amount of 0.05 mass% or more. Other examples of the lower limit include about 0.06 mass%, 0.08 mass%, 0.1 mass%, and 0.13 mass%.

[0032] Hydroxycarboxylic acids are compounds having both a carboxy group and a hydroxy group. Examples of hydroxycarboxylic acids include aliphatic hydroxycarboxylic acids, and among these, malic acid, citric acid, lactic acid, tartaric acid, etc. Examples of metals that form salts with these include sodium and potassium. Typical examples of hydroxycarboxylic acids and / or their salts include malic acid, citric acid, sodium malate, sodium citrate, etc., and particularly sodium malate.

[0033] The content ratio of the hydroxycarboxylic acid and / or a salt thereof to the compound having an isothiazolin skeleton in the concentrated dampening water composition, expressed as a mass ratio of (hydroxycarboxylic acid and / or a salt thereof) / (compound having an isothiazolin skeleton), is preferably 0 or more and less than 0.75, more preferably 0.0001 to 0.7, even more preferably 0.0001 to 0.5, and particularly preferably 0.0001 to 0.3.

[0034] The concentrated dampening water composition of the present invention may be acidic, alkaline or neutral. However, as already mentioned, the problem of dampening water spoilage occurs significantly in neutral dampening water, so that it is preferable that the concentrated dampening water composition of the present invention is neutral from the viewpoint of the effect of the present invention. The pH range of the neutral dampening water composition is preferably more than 5 and less than 9, more preferably 5.8 to 8.6, and even more preferably 6.0 to 8.0. Therefore, it is preferable that the pH of the concentrated dampening water composition of the present invention is adjusted so that the pH of the dampening water composition when diluted is within such a range. When adjusting the pH, an acid or a base may be added as a pH adjuster.

[0035] The concentrated fountain solution composition of the present invention may contain compounds generally used as concentrated fountain solution compositions, in addition to the compound having an isothiazolinone skeleton and the optionally added hydroxycarboxylic acid. Such compounds include inorganic acid salts, organic acid salts, water-soluble resins, chelating agents, wetting agents, surfactants, and defoamers. Among these, inorganic acid salts and organic acid salts are components that function as surface conditioners. Note that the organic acid salts referred to here do not include the above-mentioned hydroxycarboxylic acids and their salts.

[0036] Examples of preferred inorganic acid salts include nitrates, salts of phosphoric acid compounds, borates, sulfates, and aluminum alum. Examples of preferred salts include sodium salts, potassium salts, ammonium salts, and mixtures thereof. For example, examples of preferred nitrates include sodium nitrate, potassium nitrate, ammonium nitrate, and magnesium nitrate. The amount of inorganic acid salt added in the concentrated dampening water composition is preferably 0.05 to 8% by mass, more preferably 0.1 to 5% by mass, and even more preferably 0.5 to 3% by mass, based on the total amount of the concentrated dampening water composition. By adding the amount within the above range, the printability of the dampening water composition is improved, and the stability of the concentrated dampening water composition is improved. These inorganic acid salts may be used alone or in combination.

[0037] Examples of the salts of phosphoric acid compounds include sodium salts and potassium salts of phosphoric acid, pyrophosphoric acid, hexametaphosphoric acid, orthophosphoric acid, polyphosphoric acid, tripolyphosphoric acid, etc. Among these, hexametaphosphate salts having a calcium ion sequestering effect and a surface-leveling effect are preferred, and sodium hexametaphosphate is more preferred.

[0038] As the organic acid salt, dibasic acid salts that suppress ink staining on non-image areas of a printing plate are preferred, and examples thereof include sodium salts, potassium salts, and ammonium salts of succinic acid, oxalic acid, maleic acid, malonic acid, aspartic acid, and the like. Among these, succinic acid salts that are excellent in surface preparation and calcium ion sequestering action are preferred. The amount of organic acid salt added is preferably 0.25 to 5% by mass, more preferably 1 to 4% by mass, and even more preferably 1 to 3% by mass, based on the total concentrated fountain solution composition. By adding the amount within the above range, not only is good printability obtained when the fountain solution composition is prepared, but the stability of the concentrated fountain solution composition is also good. These organic acid salts may be used alone or in combination.

[0039] Examples of the water-soluble resin include polyacrylic acid resins such as polyacrylic acid and polyacrylic acid-maleic acid copolymer resin; cellulose resins such as carboxymethyl cellulose and carboxymethyl ethyl cellulose. The carboxyl groups contained in the resin molecule form salts such as sodium salts, potassium salts, and ammonium salts, which increases the water solubility of the resin and is more preferable. Among these, sodium polyacrylate is preferable because it shows good water solubility and has excellent compatibility with other components.

[0040] A chelating agent is a compound that sequester metal ions such as calcium ions by forming a water-soluble complex through a coordinate bond with the metal ion. Preferred examples of the chelating agent include those having three or more carboxy groups, such as ethylenediaminetetraacetic acid and nitrilotriacetic acid. Examples of such chelating agents include ethylenediaminetetraacetic acid, nitrilotriacetic acid, diethylenetriaminepentaacetate, L-glutamic acid diacetate, and 3-hydroxy-2,2'-iminodisuccinate.

[0041] The wetting agent may be any of those used in concentrated dampening water compositions, without any particular limitation. Examples of such wetting agents include alcohols, glycols, glycerins, etc. These wetting agents may be used alone or in combination.

[0042] The surfactant may be any of those used in concentrated dampening water compositions to date, without any particular limitation. Examples of such water-soluble resins include glycerin fatty acid esters, polyglycerin fatty acid esters, propylene glycol fatty acid esters, pentaerythritol fatty acid esters, and polyoxyethylenes (polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyrylphenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene-polyoxypropylene block polymers, etc.). These surfactants may be used alone or in combination.

[0043] The defoaming agent may be any of those used in concentrated fountain solution compositions, without any particular limitation. An example of such a defoaming agent is a silicone-based defoaming agent. These defoaming agents may be used alone or in combination.

[0044] To prepare the concentrated fountain solution composition of the present invention, the above-mentioned silver complex and, if necessary, each of the above-mentioned components are added to water such as pure water (ion-exchanged water, demineralized water) or soft water, and then the mixture is stirred and mixed with a stirrer.

[0045] <Mountain water composition> The dampening water composition, which is a dilution of the concentrated dampening water composition of the present invention, is also one aspect of the present invention. This dampening water composition is obtained by diluting the concentrated dampening water composition of the present invention by about 100 to 250 times, and since the antiseptic properties of the compound having an isothiazolinone skeleton are not lost by the hydroxycarboxylic acid, by using this dampening water composition for printing, problems such as decay of the dampening water and clogging of in-line filters and nozzles in dampening water supply equipment due to the generation of slime and mold can be suppressed.

[0046] The dampening water composition of the present invention is preferably used as dampening water for offset printing, and preferably has a pH in the neutral range of more than 5 and less than 9. In this case, the dampening water composition of the present invention meets the pH standard for wastewater stipulated by laws and regulations (Sewage Law), and can be treated as wastewater without any special neutralization treatment. Note that, although there are examples where a pH range of 5 to 6 is treated as weakly acidic and a pH range of 8 to 9 is treated as weakly alkaline, in the present invention, a pH range of more than 5 and less than 9 is treated as neutral, with reference to the legal standards.

[0047] The dampening water composition of the present invention can be applied to offset printing in general using dampening water. Examples of such offset printing include commercial printing for printing posters, packages, books, etc., and newspaper printing for printing newspapers. The printing method is also not particularly limited, and includes sheet-fed printing, rotary printing, etc.

[0048] <Manufacturing method of printed matter> The present invention also includes a method for producing a printed matter, which is characterized by carrying out printing using the above-mentioned dampening water composition of the present invention. The dampening water composition of the present invention is supplied to a printing plate by a known means, and moistens the non-image areas of the printing plate, thereby preventing the ink composition from adhering to the non-image areas and forming an image.

[0049] <Printed material> The present invention also provides a printed matter in which an image is formed on a paper medium using an ink composition, and the paper medium contains the components of the dampening water composition excluding water. A portion of the dampening water composition used during printing is transferred to the printing paper via the printing plate and blanket, and the water contained in the dampening water composition is then evaporated and removed from the paper medium. Therefore, a printed matter printed using the dampening water composition of the present invention contains the components of the dampening water composition excluding water. EXAMPLES

[0050] The concentrated fountain solution composition and the fountain solution composition of the present invention will be described in more detail below by showing examples, but the present invention is not limited to the following examples in any way.

[0051] [Concentrated Fountain Solution Compositions of Examples 1 to 5 and Comparative Examples 1 to 10] The materials shown in Tables 1 and 2 were mixed with a stirrer to prepare concentrated dampening water compositions of Examples 1 to 5 and Comparative Examples 1 to 10. In Tables 1 and 2, "surfactant" refers to polyoxyethylene-polyoxypropylene alkyl ether, "sodium nitrate" refers to sodium nitrate, "sodium malate" refers to sodium DL-malate, "sodium citrate" refers to sodium citrate, "surface conditioner" refers to sodium phosphate, and "MIT aqueous solution" refers to an aqueous solution containing 10% by mass of 2-methyl-4-isothiazolin-3-one. Among these, "sodium malate" and "sodium citrate" correspond to salts of hydroxycarboxylic acids, and "MIT" corresponds to a compound having an isothiazolinone skeleton. The amounts of each ingredient shown in Tables 1 and 2 are in parts by mass.

[0052] [Stability test of concentrated fountain solution composition] Accelerated stability tests were carried out on the concentrated dampening water compositions of Examples 1 to 5 and Comparative Examples 1 to 10. First, each of the concentrated dampening water compositions of Examples 1 to 5 and Comparative Examples 1 to 10 was placed in a screw tube and stored for 14 days under accelerated conditions at 60°C. Thereafter, the coloration of each sample was visually observed. The evaluation criteria for this test were as follows, and the results are shown in the "Stability" column of Tables 1 and 2. The coloration of the concentrated dampening water composition is caused by the deterioration of the preservative (i.e., a compound having an isothiazolinone skeleton) contained therein, and the most decomposed one is brown, the least decomposed one is light yellow, and the intermediate one is yellow. The yellow or brown ones showed bacterial growth in the spoilage test. ○: The concentrated dampening water composition was not colored and was colorless and transparent. △: The concentrated dampening water composition was colored yellow. ×: The concentrated fountain solution composition was colored brown.

[0053] [Table 1]

[0054] [Table 2]

[0055] As can be seen from Table 1, if the content of the salt of a hydroxycarboxylic acid in the concentrated dampening water composition is less than 0.3% by mass, coloring due to decomposition of the compound having an isothiazolinone skeleton can be suppressed. On the other hand, as can be seen from Table 2, if the content of the salt of a hydroxycarboxylic acid in the concentrated dampening water composition is 0.3% by mass or more, coloring due to decomposition of the compound having an isothiazolinone skeleton is observed. Since the compound having a decomposed isothiazolinone skeleton can no longer be expected to have antiseptic properties, it is understood that when a compound having an isothiazolinone skeleton is used as an antiseptic, the content of the hydroxycarboxylic acid or its salt in the concentrated dampening water composition should be less than 0.3% by mass.

Claims

1. A concentrated fountain solution composition comprising a compound having an isothiazolinone skeleton and a hydroxycarboxylic acid and / or a salt thereof, A concentrated dampening water composition, comprising the hydroxycarboxylic acid and / or its salt in an amount of from 0.05% by mass to less than 0.3% by mass.

2. 2. The concentrated dampening solution composition according to claim 1, wherein said hydroxycarboxylic acid is malic acid and / or citric acid.

3. 2. A concentrated dampening water composition according to claim 1, wherein said hydroxycarboxylic acid and / or its salt is sodium malate and / or sodium citrate.

4. 2. A concentrated fountain solution composition according to claim 1, wherein said hydroxycarboxylic acid and / or its salt is sodium malate.

5. 2. The concentrated dampening water composition according to claim 1, wherein the compound having an isothiazolinone skeleton is selected from the group consisting of 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 2-octyl-4-isothiazolin-3-one, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one and 1,2-benzisothiazolin-3-one.

6. 2. A concentrated dampening water composition according to claim 1, wherein said compound having an isothiazolinone skeleton is 2-methyl-4-isothiazolin-3-one.

7. 2. The concentrated dampening water composition according to claim 1, wherein the content of the hydroxycarboxylic acid and / or the salt thereof is from 0.05% by mass to 0.2% by mass.

8. A fountain solution composition which is a dilution of the concentrated fountain solution composition according to any one of claims 1 to 7.

9. A dampening water composition which is a dilution of the concentrated dampening water composition according to any one of claims 1 to 7 and has a pH of more than 5 and less than 9.

10. A method for producing a printed matter, comprising carrying out printing using the dampening water composition according to claim 8.

11. 9. A printed matter comprising a paper medium on which an image is formed using an ink composition, the paper medium containing the components of the dampening water composition according to claim 8 except for water.

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