JP7371210B1 - Concentrated dampening solution composition, dampening solution composition, method for producing printed matter using the same, and printed matter - Google Patents

Abstract

[Problem] A concentrated dampening water composition that can sufficiently suppress the growth of bacteria while avoiding the use of highly irritating preservatives, a dampening water composition obtained by diluting the same, and the same. To provide a method for producing printed matter using the method and printed matter obtained thereby. A concentrated dampening solution composition is characterized in that it contains a water-soluble silver-containing complex compound in an amount of 0.002 to 0.030% by mass as silver ions. The water-soluble silver-containing complex compound may be a complex compound of silver and compound (group) A containing at least one selected from the group consisting of amino acids, mono- or dicarboxylic acids, and nitrogen atom-containing cyclic compounds. Preferably, this concentrated dampening solution composition further contains Compound B, which is a nitrogen atom-containing cyclic compound. [Selection diagram] None

Description

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

Offset printing is a printing method that takes advantage of the property of oil-based offset printing ink compositions (hereinafter abbreviated as "ink compositions" or "inks" as appropriate) that repel water. Unlike the letterpress printing method, which uses a plate, it is characterized by the use of a printing plate without unevenness. This printing plate has a lipophilic image area and a hydrophilic non-image area instead of the unevenness. During printing, first, the non-image areas of the printing plate are moistened with dampening water to form a water film on the surface thereof, and then the ink composition is supplied to the printing plate. At this time, the supplied ink composition does not repel and adhere to the non-image area where the water film is formed, but adheres only to the lipophilic image area. In this way, an image is formed by the ink composition on the surface of the printing plate, and then the image is sequentially transferred to the blanket and paper, thereby performing printing.

The simplest composition of the dampening solution used at this time may be water alone, but water alone is often unable to fully satisfy the functions required of the dampening solution. For example, if the amount of dampening water supplied is not appropriate, the ink composition may not be sufficiently transferred to the image area, resulting in a decrease in image density, or the ink composition may adhere to the non-image area, causing printing stains. However, if the dampening solution consists of only water, the range of appropriate supply amount is narrow (this is the so-called "narrow water width" condition), and even a slight change in printing conditions will result in printing problems. It becomes difficult to obtain printed materials. Therefore, various additives such as acids, bases and their salts, surfactants, and wettable water-soluble resins are usually added to improve the viscosity, surface tension, pH, and emulsifying properties of the dampening solution for the ink composition. It is common to adjust the amount of dampening water and increase the appropriate supply amount of dampening water. Furthermore, the dampening water used in printing is usually sold and distributed in a concentrated state, and printing companies who use it can dilute this concentrated dampening water with tap water, ion-exchanged water, etc. It is common to prepare dampening water and use it for printing. This concentrated dampening solution is also called H solution (etching solution).

By the way, in recent years, the use of neutral dampening solutions has become popular, especially in the field of newspaper printing. Until now, acidic or alkaline dampening water has been used for offset printing in order to improve the leveling of the dampening water, and alkaline dampening water is widely used in the newspaper printing field. has been used. However, alkaline dampening water does not satisfy drainage standards when disposing of unnecessary dampening water after use, and it becomes necessary to perform neutralization treatment or the like before disposing of the dampening water. Against this background, as mentioned above, the use of neutral dampening solutions is increasing in the field of newspaper printing (see, for example, Patent Document 1).

However, when a neutral dampening solution is used, unlike when an alkaline dampening solution is used, there is a problem in that microorganisms such as bacteria and fungi tend to breed in the dampening solution. If these microorganisms multiply in the dampening water, slime and mold will grow in the tanks and piping used to circulate the dampening water, leading to problems such as printing defects and the generation of putrid odors. To suppress such problems, preservatives such as methylisothiazoline, chloromethylisothiazolinone, and the like are usually added to neutral dampening solution compositions.

Japanese Patent Application Publication No. 2010-120302

By adding the above-mentioned preservatives, the growth of bacteria can be significantly suppressed even in neutral dampening solutions. However, on the other hand, these preservatives are highly irritating and are not necessarily good for the human body. In particular, concentrated dampening water has a higher concentration of preservatives than normal dampening water, so care may be required when handling it.

The present invention has been made in view of the above circumstances, and provides a concentrated dampening water composition that can sufficiently suppress the generation of bacteria while avoiding the use of highly irritating preservatives, and The object of the present invention is to provide a dampening solution composition obtained by diluting the same. It is also an object of the present invention to provide a method for producing a printed matter, characterized in that printing is performed using this dampening water composition, and a printed matter obtained by the method.

As a result of intensive studies to solve the above problems, the present inventor focused on the antiseptic effect of silver compounds, and among these compounds, water-soluble silver-containing complex compounds are particularly useful in dampening solution compositions. The present inventors have discovered that it exhibits a good antiseptic effect and is highly safe, leading to the completion of the present invention. The present invention was completed based on the above findings, and provides the following.

(1) The present invention is characterized in that the water-soluble silver-containing complex compound contains 0.002 to 0.030 mass% of silver ions and 1-methylimidazole , and the water-soluble silver-containing complex compound contains creatinine and 1-methylimidazole. This is a concentrated dampening solution composition that is a complex compound of fumaric acid and silver.

( 2 ) The present invention also provides a dampening solution composition that is a diluted product of the concentrated dampening solution composition described in item (1) .

( 3 ) The present invention is also a method for producing printed matter, characterized in that printing is performed using the dampening solution composition described in ( 2 ).

( 4 ) The present invention is characterized in that an image is formed by an ink composition on a paper medium, and the paper medium contains the components of the dampening solution composition described in item ( 2 ) except for water. It is also a printed matter.

According to the present invention, there is provided a concentrated dampening solution composition that can sufficiently suppress the growth of bacteria while avoiding the use of highly irritating preservatives, and a dampening solution composition obtained by diluting the same. things are provided. Further, according to the present invention, there are also provided a method for producing a printed matter, characterized in that printing is performed using this dampening water composition, and a printed matter obtained by the method.

Hereinafter, one embodiment of the concentrated dampening solution composition of the present invention, one embodiment of the dampening solution composition of the present invention, one embodiment of the method for producing printed matter of the present invention, and one embodiment of the printed matter of the present invention I will explain about it. Note that the present invention is not limited to the following embodiments, and can be implemented with appropriate changes within the scope of the present invention.

First, one embodiment of the concentrated dampening solution composition of the present invention will be described. The concentrated dampening solution composition of the present invention is characterized by containing 0.002 to 0.030% by mass of a water-soluble silver-containing complex compound as silver ions. The concentrated dampening solution composition of the present invention may also contain various other components used in concentrated dampening solution compositions. Each component will be explained below.

The concentrated dampening solution composition of the present invention contains a water-soluble silver-containing complex compound. It is widely known that silver ions originally have antibacterial activity, and it is widely practiced, for example, to incorporate silver ion-containing compounds into plastic products to impart antiseptic properties to the products. However, concentrated dampening solution compositions contain various compounds such as various salts and rust preventive agents in order to improve printability as a dampening solution. At present, it has been difficult to use silver ion-containing compounds as preservatives in concentrated dampening solution compositions because they tend to precipitate as salts in concentrated dampening solution compositions. Under these circumstances, the present inventor has found that a water-soluble silver-containing complex compound in which silver ions form a complex can be added to a concentrated dampening water composition without any problem, and is an excellent compound. It has been found that antiseptic properties can also be obtained. The concentrated dampening solution composition of the present invention was completed based on such findings. Hereinafter, the water-soluble silver-containing complex compound may be simply referred to as a "silver complex".

The silver complex used in the present invention is a complex of silver ions and a coordination compound, and exhibits water solubility. The coordination compound is not particularly limited as long as it forms a coordination bond to form a complex compound with silver ions, and the complex compound can maintain water solubility even in concentrated dampening water. Preferred examples of such coordination compounds include compounds (group) A containing at least one selected from the group consisting of amino acids, mono- or dicarboxylic acids, and nitrogen atom-containing cyclic compounds. Note that "compound (group)" refers to a compound or a group of compounds.

Preferred amino acids include nitrogen atom-containing amino acids such as histidine and arginine. In such an amino acid, a lone pair of electrons or a carboxy group (or carboxylate anion) on the nitrogen atom coordinates with a silver ion to form a silver complex.

Mono- or dicarboxylic acids are compounds containing one or two carboxy groups. The monocarboxylic acid includes a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted monovalent aromatic hydrocarbon group having 2 carbon atoms. Examples include compounds having ~18 monovalent aromatic heterocyclic groups and one carboxyl group. Note that an oxygen atom, -NH-, -(C=O)O-, -(C=O)NH - may also contain a divalent group such as -. The dicarboxylic acid includes two carboxy groups, a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and a substituted or unsubstituted divalent aromatic group having 6 to 18 carbon atoms, which connects these carboxy groups. Examples include compounds having a hydrocarbon group or a substituted or unsubstituted divalent aromatic heterocyclic group having 2 to 18 carbon atoms.

Examples of monovalent aliphatic hydrocarbon groups having 1 to 12 carbon atoms include alkyl groups such as methyl, ethyl and propyl groups, alkenyl groups such as vinyl and propenyl groups, alkynyl groups such as ethynyl and propynyl groups, Examples include cycloalkyl groups such as cyclopropyl group and cyclobutyl group. In addition, as a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom bonded to one carbon atom of the above monovalent aliphatic hydrocarbon group is lost to form a single bond. I can list things. For example, a methylene group from which one hydrogen atom has been removed from a methyl group, which is a monovalent aliphatic hydrocarbon group, becomes a divalent aliphatic hydrocarbon group.

Examples of monovalent aromatic hydrocarbon groups having 6 to 18 carbon atoms include monocyclic aromatic hydrocarbon groups such as phenyl groups, condensed ring hydrocarbon groups such as naphthyl groups, and ring-aggregated hydrocarbon groups such as biphenylyl groups. Can be mentioned. In addition, as a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, the hydrogen atom bonded to one carbon atom of the above monovalent aromatic hydrocarbon group is lost and becomes a single bond. I can list things. For example, a phenylene group in which one hydrogen atom is lost from a phenyl group, which is a monovalent aromatic hydrocarbon group, becomes a divalent aromatic hydrocarbon group.

Examples of the monovalent aromatic heterocyclic group having 2 to 18 carbon atoms include triazolyl group, furanyl group, furyl group, thienyl group, pyrrolyl group, pyridyl group, pyrazyl group, oxazolyl group, isoxazolyl group, thiazolyl group, isothiazolyl group, Examples include imidazolyl group, pyrazolyl group, quinolyl group, isoquinolyl group, quinoxalinyl group, benzofuryl group, benzothienyl group, indolyl group, carbazolyl group, acridinyl group, thiophenyl group, bipyridyl group, oxadiazolyl group and the like. In addition, as a divalent aromatic heterocyclic group having 6 to 18 carbon atoms, a hydrogen atom bonded to one carbon atom of the above monovalent aromatic heterocyclic group is lost to form a single bond. I can list things. For example, a pyrazolylene group in which one hydrogen atom has been removed from a pyrazolyl group, which is a monovalent aromatic heterocyclic group, becomes a divalent aromatic heterocyclic group.

The hydrogen atoms contained in the above aliphatic hydrocarbon group, aromatic hydrocarbon group, and aromatic heterocyclic group may be substituted with other substituents. Such substituents include halogen atoms such as fluorine atom, chlorine atom, bromine atom, and iodine atom, oxo group, aryloxy group, aryloxycarbonyl group, hydroxy group, alkoxy group, alkoxycarbonyl group, substituted amino group, Examples include imino group, nitro group, cyano group, alkylthio group, alkylsulfonyl group, arylthio group, and arylsulfonyl group.

Preferred examples of monocarboxylic acids include acetylglycine, acetoxyacetic acid, methoxyacetic acid, and the like. Further, examples of dicarboxylic acids include adipic acid, fumaric acid, succinic acid, malic acid, glutaric acid, malonic acid, maleic acid, tartaric acid, and the like.

Examples of the nitrogen atom-containing cyclic compound include cyclic compounds containing a nitrogen atom in the ring. This cyclic compound may be aromatic or aliphatic, and may be a single ring or a condensed ring. Preferred examples of such nitrogen atom-containing cyclic compounds include imidazolinone derivatives and imidazolone derivatives.

Imidazole derivatives are compounds with an imidazole skeleton. Examples of such compounds include imidazole, 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole, imidazoline, and the like. An imidazolinone derivative is a compound having a skeleton in which C═C contained in an imidazole ring is reduced to become C—C, and one C—H contained in the ring is substituted with C═O. Imidazolone derivatives are compounds having a skeleton in which one CH contained in the imidazole ring is substituted with C=O. An example of such a compound is creatinine.

Among these silver complexes, complex compounds of silver and at least one selected from the group consisting of creatinine, fumaric acid, and imidazoline are preferably exemplified, and complexes of creatinine, fumaric acid, and silver are more preferably exemplified. Examples of such silver complexes include products such as CF-01 and CF-04 manufactured by MGC Woodchem Co., Ltd.

The content of the silver complex, that is, the water-soluble silver-containing complex compound in the concentrated fountain solution is 0.002 to 0.030% by mass in terms of silver ions. Note that "as a silver ion" means "as a mass of silver ions contained in a silver complex", and when the actual concentration of the entire silver complex is C mass %, C x (atomic weight of silver 107 .9/molecular weight of silver complex) is the concentration (mass %) "as silver ions". More preferably, this content is 0.002 to 0.025% by mass in terms of silver ions.

It is preferable that the concentrated dampening solution composition of the present invention further contains Compound B, which is a nitrogen atom-containing cyclic compound, in addition to the above-mentioned silver complex. Note that this compound B is a compound similar to the nitrogen atom-containing cyclic compound in compound (group) A that has already been described, but compound (group) A is added to the concentrated dampening solution composition in a state in which it forms a silver complex. Compound B differs in that it is added to the concentrated dampening solution composition as is, whereas Compound B is added to the concentrated dampening solution composition. Compound B contributes to increasing the stability of the silver complex in the concentrated dampening solution composition. It does not need to be added to water compositions.

Examples of the nitrogen atom-containing cyclic compound as compound B include cyclic compounds containing a nitrogen atom in the ring. This cyclic compound may be aromatic or aliphatic, and may be a single ring or a condensed ring. Preferred examples of such nitrogen atom-containing cyclic compounds include imidazole derivatives, imidazolinone derivatives, and imidazolone derivatives.

Imidazole derivatives are compounds with an imidazole skeleton. Examples of such compounds include imidazole, 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole, imidazoline, and the like. An imidazolinone derivative is a compound having a skeleton in which C═C contained in an imidazole ring is reduced to become C—C, and one C—H contained in the ring is substituted with C═O. Imidazolone derivatives are compounds having a skeleton in which one CH contained in the imidazole ring is substituted with C=O. An example of such a compound is creatinine.

The amount of compound B added in the concentrated dampening solution composition is preferably about 0.01 to 1.0% by mass, more preferably about 0.03 to 0.6% by mass, and about 0.03 to 1.0% by mass. A more preferable example is about 0.4% by mass.

The concentrated dampening solution composition of the present invention may be acidic, alkaline or neutral. However, as already mentioned, the problem of spoilage of dampening solution compositions occurs more significantly with neutral dampening solutions, and therefore, from the viewpoint of the effects of the invention, the concentrated dampening solution composition of the present invention is It can be said that it is preferable that it is neutral. The pH range of the neutral dampening solution 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, the pH of the concentrated dampening solution composition of the present invention is preferably adjusted so that the pH when diluted to form a dampening solution composition falls within this range. Note that when adjusting the pH, an acid or a base may be added as a pH adjuster.

The concentrated dampening solution composition of the present invention may contain, in addition to the above-mentioned silver complex and compound B, compounds that are generally used as concentrated dampening solution compositions. Examples of such compounds include inorganic acid salts, organic acid salts, water-soluble resins, chelating agents, wetting agents, surfactants, antifoaming agents, and the like. Among these, inorganic acid salts and organic acid salts are components that function as surface-preparing agents.

Preferred examples of the inorganic acid salts include nitrates, salts of phosphoric acid compounds, borates, sulfates, aluminum alum, and the like. Preferred examples of these salts include sodium salts, potassium salts, ammonium salts, and mixed salts thereof. For example, nitrates include sodium nitrate, potassium nitrate, ammonium nitrate, magnesium nitrate, and the like. The amount of the inorganic acid salt added in the concentrated dampening solution composition is preferably 0.05 to 8% by mass, more preferably 0.1 to 5% by mass based on the entire concentrated dampening solution composition. and more preferably 0.5 to 3% by mass. When the amount added is within the above range, the printability of the dampening water composition will be good, and the stability of the concentrated dampening water composition will be good. Note that these inorganic acid salts may be used alone or in combination.

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, and the like. Among these, hexametaphosphate having a calcium ion sequestering effect and a surface-setting effect is preferably mentioned, and sodium hexametaphosphate is more preferably mentioned.

Preferred examples of organic acid salts include hydroxycarboxylic acid salts and dibasic acid salts, which act to suppress ink adhesion to non-image areas of printing plates, such as citric acid, malic acid, succinic acid, tartaric acid, Examples include sodium salts, potassium salts, and ammonium salts of gluconic acid, lactic acid, oxalic acid, maleic acid, malonic acid, aspartic acid, and the like. Among these, citrate, malate, and succinate are preferred, and sodium malate and trisodium citrate are more preferred because of their excellent surface-levelling properties and calcium ion sequestering action. The amount of the 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 entire concentrated dampening solution composition. Can be mentioned. When the amount added is within the above range, not only good printability is obtained when the dampening water composition is made, but also good stability is obtained as a concentrated dampening water composition. Note that these organic acid salts may be used alone or in combination.

Examples of water-soluble resins 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. Note that it is more preferable that the carboxyl group contained in the resin molecule forms a salt such as a sodium salt, potassium salt, or ammonium salt, since this increases the water solubility of the resin. Among these, sodium polyacrylate is preferred because it exhibits good water solubility and excellent compatibility with other components.

A chelating agent is a compound that sequesters metal ions by coordinating with metal ions such as calcium ions to form a water-soluble complex. Preferred chelating agents include those having three or more carboxyl groups, such as ethylenediaminetetraacetic acid and nitrilotriacetic acid. Examples of such chelating agents include ethylenediaminetetraacetic acid, nitrilotriacetic acid, and diethylenetriamine. Examples include pentaacetate, L-glutamic acid diacetate, and 3-hydroxy-2,2'-iminodisuccinate.

As the wetting agent, those that have been used in concentrated dampening solution compositions can be mentioned without particular limitation. Examples of such wetting agents include alcohols, glycols, and glycerin. These wetting agents may be used alone or in combination.

As the surfactant, those that have been used in concentrated dampening solution compositions can be mentioned without 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 polyoxyethylene (polyoxyethylene alkylphenyl ethers, polyoxyethylene polyesters). Styryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene-polyoxypropylene block polymers, etc.). These surfactants may be used alone or in combination.

As the antifoaming agent, those that have been used in concentrated dampening solution compositions can be mentioned without particular limitation. An example of such an antifoaming agent is a silicone antifoaming agent. These antifoaming agents may be used alone or in combination.

To prepare the concentrated dampening water composition of the present invention, the above-mentioned silver complex and the above-mentioned components are usually added to pure water (ion-exchanged water, demineralized water), soft water, etc. as necessary. Then, stir and mix using a stirrer.

A dampening solution composition that is a diluted product of the concentrated dampening solution composition of the present invention is also part of the present invention. This dampening solution composition is obtained by diluting the concentrated dampening solution composition of the present invention approximately 100 to 250 times, and has high antiseptic properties even without containing a highly irritating preservative. For this reason, printing using the dampening water composition of the present invention prevents slime and mold from forming in tanks and piping for circulating dampening water, as well as resulting printing defects and putrid odors. Problems such as occurrence of such problems are suppressed.

The present invention also includes a method for producing printed matter, characterized in that printing is performed using the dampening solution composition of the present invention. The dampening water composition of the present invention is supplied to a printing plate by a known means, and by moistening the non-image area of the printing plate, it prevents the ink composition from adhering to the non-image area and forms an image. Let it form.

The present invention also includes a printed matter in which an image is formed using an ink composition on a paper medium, and the paper medium contains the constituent components of the dampening solution composition other than water. A part of the dampening water composition used during printing is transferred to the printing paper via the printing plate and blanket, and then the water contained in the dampening water composition evaporates and is removed from the paper medium. removed. Therefore, printed matter printed using the dampening solution composition of the present invention will contain the constituent components of the dampening solution composition other than water.

EXAMPLES Hereinafter, the concentrated dampening solution composition and the dampening solution composition of the present invention will be explained in more detail by showing Examples, but the present invention is not limited to the following Examples.

[Concentrated dampening water compositions of Reference Examples, Examples 1 to 7 and Comparative Examples 1 to 4]
By mixing each material shown in Tables 1 and 2 with a stirrer, concentrated dampening water compositions of Reference Examples, Examples 1 to 7, and Comparative Examples 1 to 4 were prepared. In Tables 1 and 2, "surfactant" is polyoxyethylene polyoxypropylene alkyl ether, "surface treatment agent 1" is sodium hexametaphosphate, and "surface treatment agent 2" is nitric acid. The "preservative" is methylisothiazolinone, and the "silver-based antibacterial agent powder" is water-insoluble particles (manufactured by Toagosei Co., Ltd., product name: "Silver Complex Aqueous Solution 1" is an aqueous solution of a complex of creatinine and fumaric acid with silver (silver ion concentration 2.5% by mass, manufactured by MGC Woodchem Co., Ltd., product name: AG Alpha CF-). 01), and "Silver complex aqueous solution 2" is a complex of creatinine and fumaric acid with silver, and is an aqueous solution of a complex containing more creatinine as a ligand than the above silver complex aqueous solution 1 (silver ion concentration 0.5% by mass, manufactured by MGC Woodchem Co., Ltd., product name: AG Alpha CF-04), and "Compound B" is 1-methylimidazole. Among these, "silver complex aqueous solution 1" and "silver complex aqueous solution 2" correspond to the silver complex in the present invention.

[Microbial test]
Reference examples, Examples 1 to 7, and Comparative Examples 1 to 4 were added to the rotten neutral dampening solution composition (commercially available general product rotten, with a bacterial count of about 10,000 per mL). 0.4% by volume of any of the concentrated dampening water compositions was added, stirred, and allowed to stand at 25°C for 24 hours. 1 mL of this dampening water composition was dropped onto a Sabouraud agar medium, spread over the entire medium, and excess water was collected with a dropper. This medium was allowed to stand at 25° C. for 3 days, and then the number of viable bacteria was confirmed. Note that adding 0.4% by volume of the concentrated dampening solution corresponds to diluting the concentrated dampening solution composition 250 times, and this means diluting the concentrated dampening solution composition to change the dampening solution composition. The dilution ratio is the same as when preparing the product. The evaluation criteria were as follows, and the results are shown in the "Microbial Test" column of Tables 1 and 2. Note that this evaluation was not performed for Comparative Example 2 because precipitation of components occurred.
○: The number of viable bacteria is less than 1,000 △: The number of viable bacteria is 1,000 or more and less than 10,000 ×: The number of viable bacteria is 10,000 or more

[Printing aptitude test]
A printing test was conducted using a two-color tower rotary printing machine Model N-750 manufactured by Higashihama Seiki Co., Ltd. For the test, each of the concentrated dampening water compositions of Reference Examples, Examples 1 to 7, and Comparative Examples 1 to 4 was diluted 250 times with soft water to prepare a dampening water composition, and this was diluted with soft water. Spray dampener SD-C Ver. No. 5 was used to supply the water application roller. The printing conditions were as follows.

Printing machine: Higashihama two-color tower printing machine N-750 (manufactured by Higashihama Seiki Co., Ltd.)
Printing plate: Thermal negative CTP plate for newspaper “HN-NV” (manufactured by Fujifilm Corporation)
Dampening water device: Spray dampener “SD-C Ver.5” (manufactured by BALDWIN)
Blanket: NP90V (manufactured by Kinyosha Co., Ltd.)
Water softener: MK-6J type (manufactured by Maruyama Seisakusho Co., Ltd.)
Soft water total hardness value: 0mg/L
Ink: NEWS WEBMASTER Ecopure LUCE (manufactured by Sakata Inx Co., Ltd.)
Printing speed: 500rpm
Temperature/humidity: 25℃/50%
Printing paper: SL paper (manufactured by Iwaki Daio Paper Co., Ltd., ultra-light paper)
Number of copies printed: 3000 copies Water amount value: Confirmed the paper surface stain evaluation when lowering the standard water amount to -7 points and the density stability when increasing it to +15 points compared to the standard water amount of 0 points.

The evaluation criteria were as follows, and the results are shown in the "Printability" column of Tables 1 and 2. Note that this evaluation was not performed for Comparative Example 2 because precipitation of components occurred.
○: There was no stain on the paper surface, and when the amount of water increased, a clearly larger decrease in concentration was not observed than with the conventional dampening water composition. A clearly larger decrease in concentration was observed than

Referring to Tables 1 and 2, the dampening solution composition obtained by diluting the concentrated dampening solution composition of the present invention exhibits antiseptic properties equivalent to those of the reference example using a preservative, and has sufficient It can be understood that it has antiseptic properties. On the other hand, Comparative Example 1, which did not contain the water-soluble silver-containing complex compound specified by the present invention, and Comparative Examples 3 and 4, which did not contain this to a specified concentration, had insufficient antiseptic properties. In Comparative Example 2, which used a silver-based antibacterial agent powder that is not water-soluble, the silver-based antibacterial agent easily precipitated, making it impossible to conduct microbial tests and printability tests. From this, it can be understood that the concentrated dampening solution composition of the present invention and the dampening solution composition obtained by diluting the same exhibit sufficient antiseptic properties without containing highly irritating preservatives.

Claims (4)

The water-soluble silver-containing complex compound contains 0.002 to 0.030% by mass of silver ions and 1-methylimidazole , and the water-soluble silver-containing complex compound is a complex of creatinine and fumaric acid with silver. A concentrated dampening solution composition that is a compound. A dampening solution composition that is a diluted solution of the concentrated dampening solution composition according to claim 1 . A method for producing printed matter, comprising printing using the dampening solution composition according to claim 2 . A printed matter, wherein an image is formed on a paper medium using an ink composition, and the paper medium contains the constituent components of the dampening solution composition according to claim 2 , except for water.