JPH11268442A - Moistening water composition for lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contain a component being hard to vaporize, suitable for concentration, having no problem regarding odors, and capable of lowering sufficiently dynamic surface tension, and obtain printing adaptability by employing a specific polyoxyethylene-polyoxypropylene block copolymer. SOLUTION: A moistening water composition for a lithographic printing plate contains at least one kind of compounds expressed by a formula (in the formula, R<1> shows a hydrogen atom or a 1-4C alkyl group; (b) shows integers of 8-22; (a) and (c) show respectively integers of 0, 1.5; however, it is not to be 0 at the same time, and 1<=a+c<=10). Making R<1> into an alkyl group can lower dynamic surface tension. Since dissolution to ink is small, the concentration is held constant in such a moistening water composition, and the administration of ink concentration becomes easier in printed matter. Accordingly, superior printing adaptability is performed, so that printed matter with fine stability can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fountain solution composition for a lithographic printing plate, and more particularly to a fountain solution composition useful for offset printing of a lithographic printing plate.

[0002]

2. Description of the Related Art Lithographic printing is a printing method that skillfully utilizes the property that water and oil are not essentially mixed. The printing plate surface has a region that receives water and repels oil-based ink, and a water-repellent oil-based ink. The former is a non-image area, and the latter is an image area. The desensitizing agent enlarges the surface chemical difference between the image area and the non-image area by wetting the non-image area with a fountain solution containing the same, thereby increasing the ink repellency of the non-image area and the image area. It has the effect of increasing ink receptivity. As the fountain solution generally conventionally known, alkali metal salts or ammonium salts of dichromic acid, phosphoric acid or a salt thereof, for example, ammonium salt,
Gum arabic, carboxymethyl cellulose (CMC)
There is an aqueous solution to which a colloidal substance such as is added. However, the fountain solution containing only these compounds has a disadvantage that it is difficult to uniformly wet the non-image area of the plate, so that the printed matter sometimes becomes dirty, and considerable skill is required to adjust the supply amount of the fountain solution. Required.

In order to remedy this drawback, a Dahlgren system using an aqueous solution containing about 20 to 25% of isopropyl alcohol as dampening water has been proposed. According to this method, the wetting of the non-image area is improved, the amount of dampening water is small, the balance between the supply amounts of the printing ink and water is easily adjusted, and the dampening water in the printing ink is easily adjusted. There are many advantages in terms of workability and accuracy of the printed matter obtained, such as a reduction in the amount of emulsification of the ink and an improvement in the transferability of the printing ink to the blanket. However, since isopropyl alcohol is easy to evaporate, a special device for keeping the isopropyl alcohol concentration of the dampening solution constant is required, which is expensive in terms of price. Further, isopropyl alcohol has a peculiar unpleasant odor and also has a problem in toxicity, which is not preferable in a working environment. In addition, even if this dampening solution to which isopropyl alcohol is added is applied to offset printing using a normal water rod, the effect cannot be exerted because isopropyl alcohol evaporates on the roller and the plate surface, so that the effect cannot be exhibited. Had become.

[0004] Further, in recent years, public interest in industrial pollution has become extremely high, the regulation of chromium ion emission in wastewater has become strict, and the use of organic solvents such as isopropyl alcohol tends to be regulated in terms of safety and health. . For this reason, a fountain solution not containing these has been desired. In order to achieve these objects, for example, Japanese Patent Publication No. 55-2507
No. 5, JP-B-55-19775, JP-B-58
Japanese Patent No. 5797 describes compositions containing various surfactants, but when these are used as dampening solutions, the surfactant concentration must be considerably increased. In actual lithographic printing, the ink / water moves violently under an ink roll, a printing plate, and a dampening water supply roll rotating at a high speed. However, the combination of surfactants proposed above has not been sufficient to completely eliminate these problems. Further, there has been a drawback that the dampening solution containing these surfactants easily foams during pumping or stirring.

On the other hand, US Pat. No. 3,877,372 discloses ethylene glycol monobutyl ether and at least one of hexylene glycol and ethylene glycol.
Solutions containing mixtures with seeds are described. U.S. Pat. No. 4,278,467 includes n-hexoxydiethylene glycol, n-hexoxyethylene glycol,
A fountain solution containing at least one of 2-ethyl-1,3-hexanediol, n-butoxyethylene glycol acetate, n-butoxydiethylene glycol acetate, and 3-butoxy-2-propanol is described. JP-A-57-199693 discloses 2-ethyl-1,3-hexanediol and propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, hexylene glycol, triethylene glycol and tetraethylene which are completely water-soluble. A fountain solution containing at least one of glycol, tripropane glycol and 1,5-pentanediol is described. Since these dampening solution compositions do not contain isopropyl alcohol, they are advantageous in terms of safety and hygiene. However, in the PS plate of an anodized aluminum substrate, it is hard to say that the non-image area is completely wet during printing, and particularly high speed. There has been a problem in that the non-image portion is stained during printing, and the shape of the halftone dot image portion is not normal, becomes large, and becomes uneven, that is, there is a problem that so-called tangling of the halftone dot image portion occurs. Furthermore, 2-ethyl-1,
3-Hexanediol has problems such as insufficient solubility in water, which is disadvantageous for obtaining a concentrated fountain solution composition and a fountain solution additive at a high concentration.

[0006] Propylene glycol monobutyl ether is known as a component of a fountain solution composition, having the ability to lower the dynamic surface tension at a low concentration and exhibiting an effect excellent in printability. Further, Japanese Patent Laid-Open No. 9-1
No. 23635 discloses a specific compound replacing isopropyl alcohol. However, since these compounds have low water solubility, it is difficult to concentrate them, and there is a problem that they are not suitable for use as a concentrated fountain solution composition. Therefore, there is a need for a fountain solution composition using components that do not have the above-mentioned disadvantages.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to contain a component which hardly evaporates, is suitable for concentration, has no problem with odor and the like, and can sufficiently lower the dynamic surface tension. An object of the present invention is to provide a fountain solution composition for a lithographic printing plate having excellent printability.

[0008]

Means for Solving the Problems In order to achieve the above object, the present inventors have no disadvantages of the components of the conventional fountain solution composition, and are environmentally safe and as a component of the concentrated fountain solution composition. As a result of repeated studies on suitable compounds, they have found that the above object can be achieved by employing a specific polyoxyethylene-polyoxypropylene block copolymer in a fountain solution composition for lithographic printing plates, and completed the present invention. It led to. Accordingly, the present invention relates to a fountain solution composition for a lithographic printing plate, comprising at least one compound represented by the following general formula (I).

[0009]

Embedded image

(Wherein R ¹ is a hydrogen atom or a carbon atom having 1
Represents an alkyl group of 4 to 4; b represents an integer of 8 to 22;
a and c each represent an integer of 0, 1 to 5; however, they are not 0 at the same time, and 1 ≦ a + c ≦ 10. )

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the compound represented by the general formula (I) used in the present invention, the alkyl group represented by R ¹ is methyl, ethyl, n-propyl, isopropyl, n
-Butyl, isobutyl and t-butyl groups. R
^{When 1} is an alkyl group, the dynamic surface tension can be further reduced. In the formula, b represents an integer of 8 to 22; a and c each represent an integer of 0, 1 to 5, provided that 1 ≦ a + c ≦ 10 without being simultaneously 0.
a and c each more preferably represent an integer of 0 or 1 to 3, and are not 0 at the same time, and 1 ≦ a + c ≦
4. Such a polyoxyethylene-polyoxypropylene block copolymer is prepared by adding ethylene oxide to polypropylene glycol in an amount of 5 to 1 based on the total weight.
It is obtained by charging at 5% by weight, performing an addition reaction, and optionally etherifying. In the general formula (I), the preferred range of the molecular weight of the polyoxypropylene represented by b is 50
0 to 1300, more preferably 600 to 1000
It is.

In the fountain solution composition for lithographic printing plates of the present invention, one kind of the compound represented by formula (I) may be used alone, or two or more kinds may be used. The content of these compounds in the fountain solution composition is suitably from 0.002 to 0.5% by weight, preferably from 0.005 to 0.3% by weight, based on the total weight of the fountain solution composition. is there. 0.002
If the amount is less than 10% by weight, the dynamic surface tension increases and the range of printability of the fountain solution composition becomes narrow. On the other hand, its content is 0.
If it exceeds 5% by weight, it is liable to be mixed into the ink and easily cause an emulsification phenomenon. The compound represented by the general formula (I) is commercially available, and such a commercial product can be used in the present invention. For example, Adeka (registered trademark) Pluronic L31 manufactured by Asahi Denka Co., Ltd. and Pluronic PE 3100 manufactured by Du Pont are commercially available.

The fountain solution composition for a lithographic printing plate of the present invention preferably further contains at least one compound represented by the following general formula (II).

[0014]

Embedded image

(Wherein, R ² represents an alkyl group having 3 to 4 carbon atoms, R ³ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 2). Specific examples of the compound shown include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, and diethylene glycol monoisopropyl ether. , Ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, ethylene Recol mono-t-butyl ether, diethylene glycol mono-t-butyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, propylene Glycol monobutyl ether, dipropylene glycol monobutyl ether, propylene glycol monoisobutyl ether, dipropylene glycol monoisobutyl ether, propylene glycol mono-t-butyl ether, dipropylene glycol mono-t-butyl ether, and the like.

The compounds represented by formula (II) can be used alone or in combination of two or more. Among them, compounds preferably used are ethylene glycol isopropyl ether, ethylene glycol monobutyl ether, ethylene glycol mono-t-butyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, propylene Glycol mono-t-butyl ether and dipropylene glycol mono-t-butyl ether. When these compounds are used in combination with the compound of the general formula (I), the performance of the dampening solution composition is specifically improved. The content of the compound represented by the general formula (II) in the fountain solution composition is 0.5 to 0.5 based on the total weight of the fountain solution composition.
5.0% by weight is suitable, preferably 0.8 to 4.0% by weight
It is. When the content of the compound represented by the general formula (II) exceeds 5% by weight, a function as a solvent appears, which deteriorates the image area of the lithographic printing plate and tends to cause deterioration such as reduction of printing durability. If the performance is adjusted by a combination of two or more, it can be used advantageously.

In the present invention, in addition to the above-mentioned compounds, the following compounds may be added, if necessary, in order to adjust the dynamic surface tension, improve the solubilization, or suppress the emulsification ratio of the printing ink within an appropriate range. it can. For example, a molecular weight of 200 to 10
Monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, 2-ethyl-1,3
-Hexanediol and their oxyethylene / oxypropylene adducts, acetylene alcohol, acetylene glycol and their oxyethylene / oxypropylene adducts, glycerin oxypropylene adducts, trimethylolpropane oxyethylene / oxypropylene adducts, Sorbitol oxyethylene / oxypropylene adduct, 3-methoxybutanol, 3-
Examples thereof include methyl-3-methoxybutanol, ethanol, and propylene glycol. Among these compounds, the auxiliary agent for lowering the dynamic surface tension has a molecular weight of 300 to 700.
An oxyethylene adduct of nearby polypropylene glycol and its methyl ether acetylene glycol can be effectively used. As the solubilizing agent, 3-methyl-3-
Methoxybutanol, ethanol, propylene glycol and the like can be advantageously used because they are inexpensive and have a sufficient solubilizing function. Among these compounds, an ethylene oxide adduct of 2-ethyl-1,3-hexanediol, an ethylene oxide adduct of trimethylolpropane, and the like can be suitably used as the emulsifier. These compounds may be used alone or in combination of two or more, and the range that can be suitably used is based on the total weight of the fountain solution composition.
It is 0.001 to 2% by weight, more preferably 0.003 to 1% by weight.

As the pH buffering 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. It is effective for buffering, moderate etching of the lithographic printing plate support or anticorrosion. Preferred organic acids include, for example, citric acid, ascorbic acid, malic acid, tartaric acid, lactic acid, acetic acid, gluconic acid, acetic acid, hydroxyacetic acid,
Examples include oxalic acid, malonic acid, levulinic acid, sulfanilic acid, p-toluenesulfonic acid, phytic acid, and organic phosphonic acid. As the inorganic acid, for example, phosphoric acid, nitric acid, sulfuric acid,
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 may be used alone. Or a mixture of two or more. The addition amount of these pH buffers to the fountain solution composition of the present invention is preferably in the range of 0.001 to 0.3% by weight, and the pH value of the fountain solution composition is in the acidic range of 3 to 7. Although it is preferable to use, it can also be used in an alkaline range of pH 7 to 11 containing alkali metal hydroxide, phosphoric acid, alkali metal salt, alkali metal carbonate, silicate and the like.

The fountain solution composition of the present invention further comprises (a) a water-soluble polymer compound, (b) a surfactant, (c) a chelate compound, (d) a preservative, (e) a rust inhibitor, (F) a coloring agent,
Components such as (g) fragrance and (h) defoamer can be added as needed. Examples of the (a) water-soluble polymer compound which can be used in the present invention include gum arabic and starch derivatives (eg, dextrin, enzymatically decomposed dextrin, hydroxypropylated enzymatically decomposed dextrin, carboxymethylated starch, phosphate starch, octenylsuccinated starch) ,
Natural products such as alginate, cellulose derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose) and their modified products, polyethylene glycol and its copolymer, polyvinyl alcohol and its derivative, polyvinylpyrrolidone, polyacrylamide and its copolymer , Polyacrylic acid and its copolymer, vinyl methyl ether / maleic anhydride copolymer,
Examples include a vinyl acetate / maleic anhydride copolymer, polystyrene sulfonic acid, and a synthesized product of the copolymer. The content of the water-soluble polymer is 0.000 with respect to the fountain solution composition.
1-0.1% by weight is suitable, more preferably 0.1% by weight.
0005-0.05% by weight.

The surfactant (b) which can be used in the present invention may be added as a solubilizing auxiliary wetting aid. For example, anionic surfactants include fatty acid salts, abietic acid salts, hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinates, straight-chain alkylbenzenesulfonates, branched-chain alkylbenzenesulfonates, alkylnaphthalenes Sulfonates, alkylphenoxypolyoxyethylenepropyl sulfonates, polyoxyethylene alkylsulfenyl ether salts, N-methyl-N-oleyltaurine sodium salts, N-alkylsulfosuccinic acid monoamide disodium salts, petroleum sulfonates, Sulfated castor oil, sulfated tallow oil, sulfates of fatty acid alkyl esters, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfate Ester salts, polyoxyethylene alkyl phenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, styrene-anhydride Partially saponified products of a maleic acid copolymer, partially saponified products of an olefin-maleic anhydride copolymer, and formalin condensates of naphthalenesulfonic acid salt are exemplified. Of these, dialkyl sulfosuccinates, alkyl sulfates and alkyl naphthalene sulfonates are particularly preferably used.

Examples of the nonionic surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, and glycerin fatty acid partial esters. , Sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol monofatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters Kind,
Polyglycerin fatty acid partial esters, polyoxyethylenated castor oils, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N,
Examples include N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, and trialkylamine oxides. In addition, a fluorine-based surfactant and a silicon-based surfactant can also be used. Among them, polyoxyethylene alkyl phenyl ethers and the like are preferably used.

Further, a surfactant such as a silicon derivative or a fluorine derivative may also be used. The content of these surfactants is appropriately 1.0% by weight or less, preferably 0.001 to 0.5% by weight, in view of foaming. Also, two or more kinds can be used in combination.

In the present invention, (c) a chelate compound may be added. Usually, the concentrated dampening solution composition is diluted with tap water, well water and the like before use. At this time, calcium ions and the like contained in the diluted tap water or well water may adversely affect the printing and cause the printed matter to be easily stained. In such a case, the above disadvantage can be solved by adding a chelate compound. Preferred chelating compounds include, for example, ethylenediaminetetraacetic acid, its potassium salt, its sodium salt; diethylenetriaminepentaacetic acid, its potassium salt, its sodium salt; triethylenetetraminehexaacetic acid, its potassium salt, its sodium salt; Acetic acid, its potassium salt, its sodium salt; nitrilotriacetic acid, its sodium salt; L-glutamic acid diacetate, its potassium salt, its sodium salt, N, N-bis-carboxymethyl-β-alanine trisethanolamine salt; 1-hydroxy Organic phosphonic acids such as ethane-1,1-diphosphonic acid, its potassium salt, its sodium salt; aminotri (methylene phosphonic acid), its potassium salt, its sodium salt, and phosphonoalkane trica It can be mentioned Bonn acids. Organic amine salts are also effective in place of the sodium or potassium salts of the above chelating agents. These chelating agents are selected from those which are stably present in the fountain solution composition and do not inhibit printability. The amount to be added to the dampening solution composition is 0.0001 to 1.0% by weight, preferably 0.0005 to 0.1% by weight.

(D) Preservatives which can be used in the present invention include phenol or its derivatives, formalin, imidazole derivatives, sodium dehydroacetate, 4-isothiazolin-3-one derivatives, benztriazole derivatives, amidine or guanidine derivatives, quaternary Ammonium salts, pyridine, quinoline or guanidine derivatives, diazine or triazole derivatives, oxazole or oxazine derivatives, bromonitropropanol, 1,1-dibromo-1-nitro-2-ethanol, 3-bromo-3-
Examples thereof include nitropentane and 2,4-diol. The preferred amount of addition is an amount that exerts a stable effect on bacteria, molds, yeasts, etc., and varies depending on the type of bacteria, molds, and yeasts. .0
The range of weight% is preferable, and it is preferable to use two or more preservatives which are effective against various molds, bacteria and yeasts.

Examples of the rust preventive (e) usable in the present invention include benzotriazole, 5-methylbenzotriazole, thiosalicylic acid, benzimidazole and derivatives thereof. As the coloring agent (f) that can be used in the present invention, food coloring agents and the like can be preferably used. For example, as a yellow pigment, CI No. 19140, 1598
5, red pigments are CI No. 16185, 4543
0, 16255, 45380, 45100, CI No. 42640 as a purple pigment, and CI No. 42 as a blue pigment.
42090, 73015, CI No. 4 as a green pigment
2095, and the like.

The fragrance (g) which can be used in the present invention can be suitably used for enhancing the printing environment by mixing a small amount of the fragrance. For example, a fountain odor, a lemon odor, a vanillin odor, and the like can be masked to provide a more convenient dampening solution. As the (h) antifoaming agent that can be used in the present invention, a silicone antifoaming agent is preferable, and among them, any of an emulsifying dispersion type and a solubilizing type can be used. The fountain solution of the present invention is generally concentrated and commercialized for commercial use. When using concentrate, tap water,
It is more economical and preferable to use the solution diluted 30 to 500 times with well water or the like.

[0027]

The fountain solution composition of the present invention is environmentally safe and has excellent ability to reduce dynamic surface tension. Particularly, since the wettability of the chromium roller and the rubber roller by the dampening water supply device of the continuous water supply system is good, it can be supplied as a uniform water film to the non-image portion of the printing plate surface. The components employed in the fountain solution composition of the present invention have a low solubility in the ink, so that it is easy to keep the concentration in the fountain solution composition constant, and thus the ink density of the printed matter is reduced. Management becomes easy. Therefore, it shows good printability,
It is possible to obtain a printed matter excellent in stability. Further, the foaming property, which is a problem in the surfactant system, is small, and the solvent odor becomes a refreshing odor as the environment of the printing room, thereby improving the working environment. And even if it concentrates and prepares, uniformity is maintained with a component dissolved, and it is easy to use.

[0028]

Next, the present invention will be described more specifically with reference to examples. In addition,% indicates weight% unless otherwise specified.

[0029]

Examples 1 to 5 and Comparative Examples 1 and 2 In the examples according to the present invention, as the compound represented by the general formula (I), Pluronic L-31 (trade name, manufactured by Asahi Denka Co., Ltd., polyoxypropylene molecular weight: 950) , Pluronic PE 3100 (trade name, manufactured by Du Pont, polyoxypropylene molecular weight: 850), and polymer of polyoxypropylene molecular weight: 750, manufactured by Takemoto Yushi Co., Ltd. (Referred to as (1)). In the comparative examples, Pluronic L-71 (polyoxypropylene molecular weight 2050, polyoxyethylene 10% by weight adduct) and Pluronic L6R (polyoxypropylene molecular weight 1750, polyoxyethylene 20% by weight adduct) were used, respectively. The compounds represented by the general formula (II) include compound A: propylene glycol mono-n-butyl ether, compound A: propylene glycol mono-t-butyl ether, compound C: ethylene glycol mono n-butyl ether, and compound D: ethylene glycol Thing t
-Butyl ether was used. According to the composition of Table 1, the fountain solution composition of each example was prepared. The unit is gram, and water was added to make up to 1000 ml.

[0030]

[Table 1] 成分Components of Examples Comparative Examples 1 2 3 4 5 1 2 (Compound of general formula (I)) Pluronic L-31 5--2.5 2--Pluronic PE 3100-5--3--Polymer (1)--5-------- -------------------------------------------------- ----------------- Pluronic L-71-----5-Pluronic L6R------5 ------------- -------------------------------------------------- -------- [Compound of general formula (II)] Compound A 200 200 150 150 150 200 200 Compound A----30--Compound C--100 100 65--Compound D 195 195 145 145 150 195 195 ----------------------------------------------- ------------------------ [pH buffer] ・ Primary ammonium citrate 25 25 25 25 25 25 25 ・ Phosphoric acid (85%) 10 10 10 10 10 10 10 (Nitrate) ・ Ammonium nitrate 5 5 5 5 5 5 5 ・ Magnesium nitrate 5 5 5 5 5 5 5 (High water solubility・ Hydroxypropylcellulose 1 1--0.5 11 ・ PVA / maleic anhydride copolymer--1 10.5--(Preservative) ・ 4-Isothiazoline-2 2 2 2 2 2 3-one derivative ・2,2-Dibromo-2-nitro-2 2 2 2 2 2 2 2-ethanol The total volume was adjusted to 1000 ml with pure water. ────────────────────────────────────

With respect to the fountain solution compositions of Examples 1 to 5 and Comparative Examples 1 and 2 prepared as described above, the suitability for liquid concentration was evaluated as shown in (a) below. Further, the prepared fountain solution compositions of Examples 1 to 5 and Comparative Examples 1 and 2 were diluted to a concentration of 2.5%, and the pH was adjusted to 4.8 to 5.5 with the 2.5% diluted solution. Adjusted to 2. These diluents were used with a diamond water dispenser of Mitsubishi Printing Machine Co., Ltd. as a high-purity MZ cyan ink of Toyo Ink Co., Ltd.
The following printing tests (b) to (h) were carried out using a plate made of PS under standard conditions. The results are shown in Table 2 below.

(A) Suitability for Liquid Concentration The prepared fountain solution composition was placed in a 1 ml polyethylene bottle, and the uniformity of the liquid was examined. No change even if left for one month A A small amount of sediment and suspended matter is generated. B Completely separates the layers. C (b) Metering roll stain Check the degree of ink stain on the metering roll for watering. Was. Good A Somewhat inferior B Inferior C

(C) Bleeding property After 5,000 and 10,000 sheets have been printed, the operation of the printing press is stopped, and the extent to which the ink in the image area has spread to the non-image area is examined. There is almost no bleeding A There is some bleeding B There is much bleeding C (d) Emulsifiability When 10,000 sheets are printed, the emulsified state of the ink on the ink kneading roll is examined. Good A Somewhat bad B Bad C

(E) Continuous stability Using fresh water as the dampening solution, printing was performed on 10,000 sheets, and the amount of dampening solution (minimum leveling amount) that did not cause stains was determined. Printing is performed using the above amount, and the determination is made on the basis of the water drainage of the printed matter (decrease in ink density) and the number of printed sheets until stains are generated. 10,000 sheets or more A 10,000 to 3000 sheets B (f) Suitability for rib mark (easiness of formation of rain streaks) The state of the solid portion and the flat net portion at a printing machine speed of 100,000,000 rph and 5000 rph was observed. Good A Somewhat inferior B Inferior C

(G) Environmental properties in the printing room: odor good A Slightly poor B Poor C (h) Influence of printing durability of plate (Positive plate suitability) Dampening water is dropped on the photosensitive layer of the positive plate. The effect was investigated. No change on the plate A A drop trace elutes on the plate in a ring shape B The photosensitive layer of the plate elutes C

[0036]

[Table 2] Example Comparative Example 1 2 3 4 5 1 2 . AAAAAAA (h) Positive plate suitability AAAAACC ────────────────────────────────────

The fountain solution composition of the present invention comprises (a) to (h)
It was found that all of the items were excellent, that a good printed matter was obtained, and that the suitability for fountain solution was also excellent.

Claims (3)

[Claims] 1. A fountain solution composition for a lithographic printing plate comprising at least one compound represented by the following general formula (I). Embedded image (Wherein, R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; b represents an integer of 8 to 22; a and c each represent an integer of 0, 1 to 5; And 1 ≦ a + c ≦ 10.) 2. The method according to claim 1, wherein at least one compound of the general formula (I) is present in an amount of from 0.002 to 2 based on the total weight of the fountain solution composition.
The fountain solution composition for a lithographic printing plate according to claim 1, wherein the fountain solution contains 0.5% by weight. 3. The method according to claim 1, wherein at least one compound of the general formula (I) is present in an amount of from 0.002 to
3. A lithographic printing plate according to claim 1, wherein the lithographic printing plate contains 0.5% by weight and at least one compound represented by the following general formula (II): 0.5 to 5.0% by weight. Fountain solution composition. Embedded image (Wherein, R ² represents an alkyl group having 3 to 4 carbon atoms,
R ³ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 2. )