JPH07125472A - Dampening water composition for lithographic printing plate - Google Patents

Abstract

PURPOSE:To improve printability, aging stability of liquid by incorporating a specific unit chemical structure in water soluble polymer compound in dampening water composition for a lithographic printing plate and specifying viscosity of the water soluble solution and degree of substitution of its compound carboxymethyl-containing group. CONSTITUTION:Dampening water composition for a lithographic printing plate contains water soluble high-molecular composition, and comprises a unit chemical structure represented by the general formula in the water soluble compound, wherein a particle size of water soluble solution of 10wt.% of its compound is set to a range of 5-100cps at 25 deg.C, and degree of substitution of carboxymethyl-containing group of the compound is set to a range of 1.0-3.0 or preferably 1.2-2.9. In the formula, R<1>-R<3> are hydrogen atom,-(CH2CH2O)CH2 COOM group, and at least one of the R<1>-R<3> is-(CH3CH2O)n-CH2COOM. n is integer of 0 or 1-5, M is H, Na, K, Li or NH4. Thus, a printed matter in which liquid aging stability is enhanced and which has excellent stability is obtained.

Description

Detailed Description of the Invention

The present invention relates 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 essentially immiscible. 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 widens the surface chemical difference between the image area and the non-image area by moistening the non-image area with the fountain solution containing the desensitizing agent, and the ink repulsion of the non-image area and the image area It has the effect of increasing the ink receptivity. As the fountain solution generally known in the past, an alkali metal salt or ammonium salt of dichromic acid, phosphoric acid or a salt thereof, such as an 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 drawback that it is difficult to uniformly wet the non-image area of the plate, which sometimes causes stains on the printed matter, and requires considerable skill to adjust the supply rate of the fountain solution. There was a problem such as requiring In order to improve this drawback, a Dahlgren system has been proposed in which an aqueous solution containing about 20 to 25% of isopropyl alcohol is used as fountain solution. According to this method, the non-image area is well wetted, the amount of dampening water is small, the balance of the supply amount of printing ink and water is easy to adjust, and the dampening water in the printing ink is easily adjusted. Has a number of advantages in terms of workability and accuracy of the obtained printed matter, such as a reduction in the emulsification amount of the ink and a better transfer of the printing ink to the blanket.

However, since this isopropyl alcohol easily evaporates, a special device for keeping the isopropyl alcohol concentration of the dampening water constant is required, which is expensive in terms of price. In addition, isopropyl alcohol has a peculiar unpleasant odor and is problematic in terms of toxicity, which is not preferable in the work environment. Further, even if the dampening water containing this isopropyl alcohol is applied to offset printing using a normal water bar, isopropyl alcohol evaporates on the roller and the plate surface, so that the effect cannot be exhibited. It was. Furthermore, in recent years, there has been a great increase in public interest in industrial pollution, and the regulation of chromium ion emissions in wastewater has become stricter.
Also, the use of organic solvents such as isopropyl alcohol tends to be regulated in terms of safety and hygiene. Therefore, a fountain solution that does not contain these has been desired. In order to achieve these objects, for example, Japanese Patent Publication No. 55-25075, Japanese Patent Publication No. 55-19757, and Japanese Patent Publication No. 58-57.
Japanese Patent Publication No. 97 describes compositions containing various surfactants, but when these are used as fountain solution, it is necessary to make the surfactant concentration considerably high.
Also, in actual lithographic printing, ink / printing under a high-speed rotating ink roll, printing plate, or fountain solution supply roll
Since water is moving violently, there are problems such as water adhering to the ink film and ink spreading on the surface of the water, but the combination of the surfactants proposed above is
It was not enough to completely eliminate these problems. Further, there is a drawback that the fountain solution containing these surfactants easily foams during pumping or stirring.

On the other hand, US Pat. No. 3,877,372 describes a solution containing a mixture of ethylene glycol monobutyl ether and at least one of hexylene glycol and ethylene glycol. U.S. Pat.No. 4,27
No. 8,467 includes n-hexoxydiethylene glycol,
n-hexoxyethylene glycol, 2-ethyl-1,
A fountain solution containing at least one of 3-hexanediol, n-butoxyethylene glycol acetate, n-butoxydiethylene glycol acetate, 3-butoxy-2-propanol is described. JP-A-57-
In 199693, 2-ethyl-1,3-hexanediol and completely water-soluble propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, hexylene glycol, triethylene glycol, tetraethylene glycol, tripropane glycol, A fountain solution containing at least one 1,5-pentanediol is described. Since these fountain solution compositions do not contain isopropyl alcohol, they are advantageous in terms of safety and hygiene, but it is difficult to say that the non-image area during printing is completely wet on the PS plate of anodized aluminum substrate, especially at high speed. There is a problem in that the non-image area is smeared during printing, or the shape of the halftone dot image area is not normal, and becomes large and uneven, so-called entanglement of the halftone dot image area occurs. Further, 2-ethyl-1,3-hexanediol is not sufficiently soluble in water, which is disadvantageous in obtaining a concentrated concentrated fountain solution composition and a fountain solution additive. It was

By the way, it is usual that the dampening water contains a water-soluble polymer compound as a stain preventing component.
This water-soluble polymer compound has the effect of preventing stains in the non-image area of the printing plate and stains on the water supply roll of the printing machine, thus providing stable printing. At present, gum arabic, which is a natural product, is widely used as such a water-soluble polymer compound from the viewpoint of performance. However, because gum arabic is mainly produced in Sudan in the Arabian gum belt of the African continent, it has become unstable in recent years due to natural phenomena such as drought or political instability. Therefore, the development of an alternative hydrophilic polymer has been desired. As its substitutes, fibrin and its derivatives (eg carboxymethylcellulose, carboxyethylcellulose, methylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, ethylcellulose etc.), starch derivatives (eg dextrin, enzymatically decomposed dextrin, hydroxypropylated starch, carboxymethyl) Starch, phosphorylated starch, octenylsuccinate starch, etc.), alginic acid and its derivatives (eg hydroxypropylated alginic acid,
(Hydroxyethylated alginic acid, etc.), polyethylene glycol and its copolymers, polyvinyl alcohol and its copolymers, polyvinylpyrrolidone, polyacrylamide and its copolymers, polyacrylic acid and its copolymers, polystyrene sulfonic acid Also, synthetic hydrophilic polymers such as copolymers thereof and vinyl acetate / maleic anhydride copolymers have been proposed as gum arabic substitutes. Among these alternatives, carboxymethyl cellulose, in particular, has the same antifouling ability as gum arabic, but also has the following defects.

The fountain solution is generally concentrated when it is commercialized for economic reasons, and is generally diluted with water when used for printing. The fountain solution is usually used in the acidic pH range. Carboxymethyl cellulose generally has a carboxymethyl substitution degree of 0.6 to 0 in order to be water-soluble.
8. Add this to an alkali metal salt (eg Na, K, Li)
To improve the solubility in water. When these compounds are used in dampening water, their solubility is greatly lowered in the acidic region, making it difficult to concentrate them. In addition, if a running process is performed using an automatic pH controller, the dropping nozzle may be easily clogged. Further, there is a problem that the ability to prevent stains on prints is reduced. As an even bigger problem, due to the health problems of isopropyl alcohol in recent years, other alcohols have been used as alternative compounds,
Solvents such as glycol and glycol ether are proposed,
Some have been put to practical use. When these isopropyl alcohol alternative solvents are concentrated, the dissolution ability further decreases, and phenomena such as liquid separation occur, resulting in a problem that the commercial value is extremely poor. Further, when dissolved in cold water or warm water, swollen particles aggregate to form a viscous mass called "Mamako", which makes it difficult to dissolve easily, which affects workability and is difficult to put into practical use. Was considered. That is, it has a big defect that it does not satisfy all the properties required as a dampening water alternative to gum arabic for lithographic printing plates.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fountain solution composition for a lithographic printing plate which solves the above-mentioned drawbacks. Another object of the present invention is to provide a fountain solution composition for a lithographic printing plate which does not have the above-mentioned drawbacks and uses a water-soluble polymer instead of gum arabic.

[0008]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to achieve the above object, it was found that the above object can be easily solved by using the following fountain solution composition for a lithographic printing plate. The present invention has been found out. That is, the present invention provides a fountain solution composition for a lithographic printing plate containing a water-soluble polymer compound, wherein the water-soluble polymer compound has a unit chemical structure represented by the following general formula (I): 1
Particle size of 0% by weight aqueous solution is 5 to 100 cp at 25 ° C.
and the degree of substitution of the carboxymethyl-containing group of the compound is 1.0 to 3.0, more preferably 1.2 to 2.9. It is a thing. General formula (I)

[0009]

[Chemical 2]

In the general formula (I), R ^{1 to} R ³ may be the same or different from each other, and each is a hydrogen atom or-(CH ₂
Show CH ₂ O) _n -CH ₂ COOM group, at least one of R ¹ to R ³ is - shows the _{(CH 2 CH 2 O) n} -CH 2 COOM. n is 0 or 1
Represents an integer of 5 and M represents H, Na, K, Li or NH ₄ . Here, the “degree of substitution of the carboxymethyl-containing group” means
Included in the unit chemical structure represented by general formula (I) is-(CH ₂
CH ₂ O) _{n —} The number of CH ₂ COOM groups (average value). The compound represented by the above general formula, as described in "Large Organic Chemistry" No. 19, dissolves cellulose in a solvent and caustic soda, and then adds monochloroacetic acid to sufficiently carry out the carboxymethylation reaction. Can be synthesized by neutralizing and purifying after the reaction. Alternatively, ethylene oxide may be allowed to act in the presence of cellulose and caustic soda, or ethylene chlorohydrin may be reacted, followed by carboxymethylation using monochloroacetic acid, followed by neutralization purification. Then, by treating with an oxidizing agent such as hydrogen peroxide or sodium persulfate, a 10% by weight aqueous solution at 25 ° C.
Has an intrinsic viscosity of 5 to 100 cps, more preferably 1
Adjust the molecular weight to be 0 to 50 cps.

The content of the above compound in the fountain solution composition for lithographic printing plates of the present invention is 0.0001 to 0.1 with respect to the composition at the time of use (hereinafter simply referred to as "fountain solution composition"). The range of weight% is preferable, and more preferably 0.0003 to 0.
It is in the range of 05% by weight. In the present invention, the above compound may be used as a mixture with other water-soluble polymer. For example, gum arabic, starch derivatives (for example, dextrin, enzyme-degraded dextrin, hydroxypropylated enzyme-degraded dextrin, carboxymethylated starch, phosphate starch, octenylsuccinic starch), alginates, fibrin derivatives (for example, carboxymethyl cellulose, carboxy). Natural products such as ethyl cellulose and methyl cellulose and modified products thereof, polyethylene glycol and copolymers thereof,
Polyvinyl alcohol and its derivatives, polyvinylpyrrolidone, polyacrylamide and its copolymers, polyacrylic acid and its copolymers, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, polystyrene sulfonic acid And synthetic compounds thereof. The content of the water-soluble polymer is preferably 0.0001 to 0.1% by weight, more preferably 0.0005 to 0.05% by weight, based on the fountain solution composition.

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 as a pH buffering agent, and these compounds are used for pH adjustment of the fountain solution or pH buffering, planographic printing. It is effective for proper etching or corrosion prevention of the printing plate support. Preferred organic acids include, for example, citric acid, ascorbic acid, malic acid, tartaric acid, lactic acid, acetic acid,
Gluconic acid, acetic acid, hydroxyacetic acid, oxalic acid, malonic acid,
Examples thereof include levulinic acid, sulfanilic acid, p-toluenesulfonic acid, phytic acid, and organic phosphonic acid. Examples of the inorganic acid include phosphoric acid, nitric acid, sulfuric acid, and polyphosphoric acid. Further, alkali metal salts, alkaline earth metal salts or ammonium salts of these organic acids and / or inorganic acids, and organic amine salts are also preferably used.
The inorganic acid and / or the salt thereof may be used alone or as a mixture of two or more kinds. The amount of these compounds added to the fountain solution composition of the present invention is 0.001-
A preferable range is 0.3% by weight, and the pH value of the fountain solution composition is 3
It is preferably used in an acidic range of 7 to 7, but can also be used in an alkaline range of pH 7 to 11 containing an alkali metal hydroxide, phosphoric acid, an alkali metal salt, an alkali metal carbonate, a silicate or the like. .

In order to control the dynamic surface tension and / or to suppress the mixing ratio (emulsification ratio) of the printing ink within an appropriate range, the fountain solution composition of the present invention may further contain 2-ethyl as necessary. At least one compound consisting of ethylene oxide and / or propylene oxide adduct of -1,3-hexanediol and ethylene oxide and / or propylene oxide adduct of acetylene alcohol or acetylene glycol can be contained. Examples of the acetylene alcohol or acetylene glycol include 2,4,7,9
-Tetramethyl-5-decyne-4,7-diol, 2,
5-dimethyl-3-hexyne-2,5-diol, 3-
Ethylene oxide and / or propylene oxide adducts such as methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, and 3,6-dimethyl-4-octyne-3,6-diol are preferable. used. In the fountain solution composition of the present invention, the above compound is 0.0001 to 1% by weight.
It can be used in the range of.

Further, the fountain solution composition of the present invention contains a surfactant for the purpose of imparting the ability to rapidly spread the fountain solution to the non-image area when the fountain solution is applied to the lithographic printing plate. You may add. For example, as anionic surfactants, fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinates, linear alkylbenzene sulfonates, branched alkylbenzene sulfonates, alkylnaphthalene Sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkylsulfenyl ether salts, N-methyl-N-oleyl taurine sodium salts, N-alkylsulfosuccinic acid monoamide disodium salts, petroleum sulfonates, Sulfated castor oil, sulfated beef tallow oil, fatty acid alkyl ester sulfate ester salts, alkyl sulfate ester salts, polyoxyethylene alkyl ether sulfate ester salts, fatty acid monoglyceride sulfate Ester salts, polyoxyethylene alkyl phenyl ether sulfate ester salts, polyoxyethylene styryl phenyl ether sulfate ester salts, alkyl phosphate ester salts, polyoxyethylene alkyl ether phosphate ester salts, polyoxyethylene alkylphenyl ether phosphate ester salts, styrene-anhydrous Examples thereof include partially saponified products of maleic acid copolymers, partially saponified products of olefin-maleic anhydride copolymers, and naphthalenesulfonate formalin condensates. Among these, dialkyl sulfosuccinates, alkyl sulfate ester salts and alkyl naphthalene sulfonates are particularly preferably used.

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

Further, a surface active agent such as a silicon derivative or a fluorine derivative may also be mentioned. Considering foaming, the content of these surfactants is 1.0% by weight or less, preferably 0.001 to 0.5% by weight. Further, the dampening water composition of the present invention may contain a wetting agent in order to prevent early evaporation of the dampening water applied to the non-image area of the lithographic printing plate. For example, ethylene glycol, triethylene glycol, butylene glycol, hexylene glycol, diethylene glycol, glycerin, trimethylolpropane, diglycerin and the like are preferably used. These wetting agents may be used alone,
You may use 2 or more types together. Generally, the wetting agent is 0.00
It is preferably used in an amount of 1 to 0.1% by weight.

Further, a chelate compound may be added to the concentrated dampening water composition of the present invention. Usually, a concentrated dampening water composition is diluted with tap water, well water, etc. before use. At this time, the calcium ions contained in the tap water or well water diluted may adversely affect the printing and cause the printed matter to be easily soiled. In such a case, a chelate compound can be added to eliminate the above drawbacks. Preferred chelate 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; hydroxyethylethylenediaminetriacetic acid. Acetic acid, its potassium salt, its sodium salt; nitrilotriacetic acid, its sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, its potassium salt, its sodium salt; aminotri (methylenephosphonic acid), its potassium salt, its sodium Examples thereof include organic phosphonic acids such as salts and phosphonoalkane tricarboxylic acids. Instead of the sodium salt or potassium salt of the above chelating agents, salts of organic amines are also effective. As these chelating agents, those which are stably present in the fountain solution composition and which do not impair the printability are selected. The amount added to the fountain solution composition is 0.0001 to 1.0% by weight, preferably 0.0005 to 0.1% by weight.

Furthermore, if necessary, the fountain solution composition of the present invention may contain the following compounds. These compounds are added for various purposes such as imparting suitability to various dampening water supply systems such as direct water supply system and indirect water supply system, or improving wettability to various water supply rollers. As a concrete example,
Ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, ethylene glycol monoethyl ether,
Diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, triethylene glycol monoisobutyl ether, ethylene glycol monopropyl ether , Diethylene glycol monopropyl ether, triethylene glycol monopropyl ether, ethylene glycol monotertiary butyl ether, diethylene glycol monotertiary butyl ether, triethylene glycol monotertiary butyl ether, ethylene glycol monohexyl ether, diethylene glycol Rumonohexyl ether, triethylene glycol monohexyl ether, ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, triethylene glycol monophenyl ether, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, propylene glycol monomethyl ether, di Propylene glycol monomethyl ether,

Tripropylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monoethyl ether, tetrapropylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, tri Propylene glycol monopropyl ether, propylene glycol monoisopropyl ether, dipropylene glycol monoisopropyl ether, tripropylene glycol monoisopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, propylene glycol monoisobutyl ether Ter, dipropylene glycol monoisobutyl ether, tripropylene glycol monoisobutyl ether, propylene glycol monotertiary butyl ether, dipropylene glycol monotertiary butyl ether, tripropylene glycol monotertiary butyl ether, polypropylene glycol having a molecular weight of 200 to 1000, and compounds thereof. Monomethyl ether, monoethyl ether, monopropyl ether, isopropyl ether, monobutyl ether and the like. Among these, ethylene glycol monobutyl ether, polypropylene glycol having a molecular weight of 200 to 1000, propylene glycol monopropyl ether, and monoalkyl (C ₁ -C ₄ ) ether of polypropylene glycol having an average number of added moles of 2 to 7 are preferable.
These compounds may be used alone or in combination of two or more kinds, and the range that can be suitably used is 0.1 to 5% by weight, and the more preferable range is 0.5 to 3% by weight.

Further, a rust preventive, various coloring agents, antifoaming agents, preservatives and the like can be added to the fountain solution composition of the present invention. Examples of rust preventives include benzotriazole, 5-methylbenzotriazole, thiosalicylic acid, benzimidazole and derivatives thereof. As the colorant, a food dye or the like can be preferably used. For example, as yellow pigments, CI No. 19140 and 15985, and as red pigments, CI No. 19140 and 15985. 16185, 45430, 1625
5, 45380, 45100, CIN as purple pigment
o. 42640, CI No. 4209 as a blue dye
0,73015, CI No. 4209 as green pigment
5, etc. As the defoaming agent, a silicon defoaming agent is preferable, and among them, an emulsion dispersion type or a solubilizing type can be used. Further, as a preservative, phenol or its derivative, formalin, imidazole derivative, sodium dehydroacetate, 4-isothiazolin-3-one derivative, benztriazole derivative, amidine or guanidine derivative, quaternary ammonium salt, pyridine, quinoline or guanidine. And derivatives of diazine or triazole, derivatives of oxazole or oxazine, and the like. The preferable addition amount is an amount that stably exerts an effect on bacteria, molds, yeasts, etc., and varies depending on the types of bacteria, molds, yeasts, but relative to the fountain solution composition, 0.001- The range of 1.0% by weight is preferable, and it is preferable to use two or more kinds of preservatives which are effective against various molds, bacteria and yeasts in combination. When the above-mentioned components are usually used on a commercial basis, they are generally concentrated, commercialized and put on the market. When the concentrated solution is used, it is economical and preferable to use it by diluting it with tap water, well water, etc. 30 to 500 times.

[0021]

INDUSTRIAL APPLICABILITY The fountain solution composition of the present invention has extremely good printability, and is excellent in the stability of the liquid over time, so that a stable printed matter can be obtained.

[0022]

EXAMPLES Next, the present invention will be described more specifically by way of examples. Unless otherwise specified,% means% by weight. As dampening water compositions, 1 to 5 in Table 1 were prepared, and as dampening water compositions, the dampening water compositions shown in 6 to 7 were prepared. The unit is gram, and water was added to make 1000 ml. The test results are summarized in Table 2.

[Table 1] Table 1 ────────────────────────────────── A B C ──────── ─────────────────────────── Viscosity (cps) 5-8 8-12 20-25 (10 wt% aqueous solution 25 ° C) ── ──────────────────────────────── Substitution degree 1.2 1.6 2.6 2.6 ──────── ────────────────────────────

[0023]

[Table 2] Table 2 ──────────────────────────────────── Actual example ───── ───────────────── 1 2 3 4 5 ───────────────────────────── ──────── Water A 30 − − 6 − ────────────────────────────────── Melt B − 30 − − − ─────────────────────────────────────────────────────────── ─────────────────────────────── Tree hydroxypropyl cellulose − − − − − (HPC manufactured by Shin-Etsu Chemical Co., Ltd.) Fat ────────────────────────────────── Carboxymethyl cellulose − − − − − CMC Serogen 5A Daiichi Kogyo Co., Ltd., substitution degree of carboxymethyl group: about 0.7) ─────────────────────────── ──────── Gum arabic − − − − − ──────────────────────────────────── ─ PH Phosphoric acid 12 12 12 3 3 Slow phosphoric acid 2nd ammon 6 6 6 6 6 Citrate 2nd ammon 20 20 20 12 12 Agent ────────────────── ────────────────── Nitrate Magnesium nitrate 30 30 30 − − Acid Potassium nitrate 10 10 10 8 8 Salt ──────────────── ──────────────────── Interface Oxyethyleneoxypro 2 2 2 2 2 Pyrene block copolymer Activator (Pluronic L62 (Asahi Denka Co., Ltd.) ── ──────────────────── ────────────── Anti-isothiazoline compound-containing 10 10 10 4 4 Hui (Bio-Hope) Keiai Kasei Co., Ltd. ──────────────── ───────────────────── ethylene glycol monobutyl − − − 380 − soluble ether propylene glycol monopropyl − − − − 380 ether propylene glycol monobutyl − − − 20 20 Ate agent ────────────────────────────────── Add pure water 1000 ml ─────── ────────────────────────────── (diluted with INNaOH to adjust the pH to 5.3-5.5)

[Table 3] Continuation of Table 2 ──────────────────────────────────── Comparison Comparison ─── ─────────────────── 6 7 8 9 10 ────────────────────────── ────────── Water A − − − − − ────────────────────────────────── ─Solution B − − − − − ────────────────────────────────────────── ───────────────────────────────── Tree hydroxypropyl cellulose − − − − 6 (manufactured by HPC Shin-Etsu Chemical Co., Ltd.) ) Fat ────────────────────────────────── Carboxymethyl cellulose − − 30 6 − (CMC Serogen 5A Daiichi Kogyo Co., Ltd.) ─────────────────────────────────── Gum arabic 30 6 − − − ──────────────────────────────────── pH Phosphoric acid 12 3 12 3 3 Mild phosphate second ammonium 6 6 6 6 6 Citrate second ammonium citrate 20 12 20 12 12 Agent ──────────────────────────── ────────── Magnesium nitrate 30 − 30 − − Acid potassium nitrate 10 8 10 8 8 Salt ──────────────────────── ──────────── Interface Oxyethyleneoxypro 2 2 2 2 2 Pyrene block copolymer Activator (Pluronic L62 (Asahi Denka Co., Ltd.) ────────── ────────────────────────── Containing isothiazoline compounds 10 4 10 4 4 Hui (Bio-Hope) Kai Kasei Co., Ltd. ─────────────────────────────── ────── Ethylene glycol monobutyl − 380 − − 380 Solvent ether Propylene glycol monopropyl − − − 380 − Ether propylene glycol monobutyl − 20 − 20 20 Ether agent ───────────── ───────────────────── Add pure water 1000 ml ─────────────────────── ───────────── (Diluted with INNaOH to adjust the pH to 5.3-5.5)

Preparation Method and Conditions and Solubility of Water-Soluble Resin Each water-soluble resin was dissolved at 400 rpm with a stirrer Three One Motor (manufactured by Shinto Kagaku Co., Ltd.), and after dissolution,
Add additives sequentially and dissolve. Since Comparative Examples 6 and 7 have poor solubility in cold water, they are dissolved by heating at 50 to 60 ° C. The water-soluble resins A, B and C of the present invention have excellent solubility.

[0025]

[Table 4] Comparison of solubility in water ──────────────────────────── Examples Comparative examples Dissolution time Conditions ───── ─────────────────────── 1 4 to 7 minutes Cold water 2 〃 〃 3 〃 〃 6 3:20 Heating (50 to 60 ° C) 8 1 30 minutes cold water ─────────────────────────────

Examples 1 to 3 and comparative examples 6 and 8 in which the respective liquids were prepared
The fountain solution was diluted 200 times, and 5% of isopropyl alcohol was added to the solution to examine the printability. The fountain solutions of Examples 4 and 5 and Comparative Examples 7 and 9 were diluted 1:40,
About printability with the same solution Using Heidelspeed Master (equipped with Alcolor water supply), MK-V cyan ink from Toyo Ink Co., Ltd. and FPS-III from Fuji Photo Film Co., Ltd. as a plate to be used were made under standard conditions. A printing test was carried out using the above. The evaluation results of printability at that time are shown in Table 5.

A. Metering roll stains: Check the degree of ink stains on the water metering roll. good. A A little inferior. B Inferior C b. Bleedability: The operation of the printing machine is stopped after printing 5000 and 10000 sheets, and the extent to which the ink in the image area is bleeding into the non-image area is examined. Almost no bleeding. A There is some blurring. B There is a lot of bleeding. C c. Emulsification: When 10000 sheets are printed, the emulsified state of the ink on the ink kneading roll is examined. good. A A little bad. B Bad. C d. Continuous stability: 1000 using fresh water as dampening water
Printing 0 sheets, obtaining the amount of dampening water that does not cause stains (minimum amount of water), printing using various types of dampening water at this minimum amount of water, and printing until stains on the printed matter occur. Judge by the number of sheets. 10000 sheets or more A 1000-3000 sheets Be) Stability of concentrated stock solution: put in a polyethylene bottle and examined stability with time at room temperature (indoor), 40 ° C / 80% RH condition and -5 ° C condition. No change A Slight change B Change C C liquid separation D f) Drip stability of automatic replenisher: Nozzle clogging was investigated. Good A There is solid content at the edge of the nozzle B Easy to clog C The fountain solution of the present invention is excellent in all of the items (a) to (f), and good printed matter is obtained, and the fountain solution is also good. It was found that the suitability was also excellent.

[Table 5] Table 5 ──────────────────────────────────── Actual Example Ratio Comparative Example ── ─────────────────────── 1 2 3 4 5 6 7 8 9 10 ────────────────── ─────────────────── Metering roll A A A A A A A A A A A to B B Dirt ──────────────── ───────────────────── Ink A A A A A A A A A A A A to B Bleedability ────────────── ────────────────────── Emulsifying ability A A A A A A A A A B B B C ──────────────── ──────────────────── Continuous stability A A A A A A A A A B B B C ────────────── ───────────────────── Stock solution stability A A A A A B A D B B D D A ──────────────── ──────────────────── Dropping stability A A A A A A B B-C C A ───────────────── ────────────────────

Claims (1)

[Claims] 1. A fountain solution composition for a lithographic printing plate containing a water-soluble polymer compound, wherein the water-soluble polymer compound has a unit chemical structure represented by the following general formula (I): The viscosity of a 10% by weight aqueous solution of
A fountain solution composition for a lithographic printing plate, wherein the carboxymethyl-containing group has a degree of substitution of 1.0 to 3.0 in the range of 00 cps. General formula (I) In formula (I), R ^{1 to} R ³ may be the same as or different from each other, and each is a hydrogen atom or — (CH ₂ CH ₂ O) _n.
A —CH ₂ COOM group is shown, but at least one of R ^{1 to} R ³ is — (CH ₂ CH ₂ O) _n —CH ₂ COOM. n represents 0 or an integer of 1 to 5, and M represents H, Na, K, Li or NH ₄ .