JP2946976B2 - Fountain solution concentrate for printing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fountain solution concentrate for lithographic printing, and more particularly to a fountain solution concentrate which is diluted with water and used as a fountain solution.

[0002]

2. Description of the Related Art Lithographic printing is a printing method in which printing is performed using a printing plate having a portion corresponding to an image portion as a grease-sensitive surface and a portion corresponding to a non-image portion as a hydrophilic surface. That is, the ink is attached to the oil-sensitive surface and the fountain solution is attached to the hydrophilic surface, and printing is performed using the mutual repulsion between the ink and the fountain solution. The fountain solution is applied to the plate before the ink is applied to the plate. The functions of the dampening solution are (1) preventing ink from adhering to the non-image area, (2) cleaning the printing surface, (3) preventing the change of the image area, and (4) keeping the printing plate temperature constant. . Since the fountain solution has the above functions, various compounds are added to the water. The pH of the dampening solution is acidic in a normal PS plate offset printing method, but alkaline in a newspaper offset press. The reason for making the dampening solution alkaline is that, in the printing method in which the printing ink is set by penetrating the paper, such as newspaper printing, paper powder easily mixes into the dampening solution, and aluminum sulfate contained in the paper as a sizing agent is used. This is because it is acidic in water and needs to be neutralized.

[0003] Since the dampening solution is mainly composed of water, it may rot or mold during use or storage. In particular, in a printing environment, the dampening solution tends to rot because the paper dust is mixed into the dampening solution. When the dampening solution rots, it not only gives off a bad smell, but also generates slime, which adheres to the dampening solution tank, the piping of the printing press and the watercraft, and in some cases, adheres to the plate and rolls via the water supply roll to remove dirt. turn into. In addition, discoloration, contamination, and pH change of the dampening solution are caused, and the physical properties of the dampening solution are also changed. In newspaper printing, fountain solution may be supplied by a spray nozzle method, and slime is generated, which causes a serious accident that the nozzle is clogged and fountain solution is not supplied to cause stains. Each time, the printing worker must clean or re-prepare the dampening solution, which is an obstacle to the work. The decay and mold generated in the fountain solution are caused by the growth of various fungi originally existing in the water.

Conventionally, preservatives and fungicides have been added to fountain solutions to prevent spoilage and the like.
JP-A-57-125096 discloses a fountain solution containing a 4-isothiazolin-3-one compound.
JP-A-4-16187 discloses, as preservatives added to fountain solution, other than the above compounds, phenol or its derivatives, formalin, imidazole derivatives, sodium dehydroacetate, benzotriazole derivatives, amidizing anidine derivatives, quaternary Ammonium salts, pyridine,
Derivatives such as quinoline and guanidine, diazines, triazole derivatives, oxazoles, oxazine derivatives and the like are disclosed. However, such preservatives are effective with acidic dampening solutions but not with alkaline dampening solutions. For example, 4-isothiazolin-3-one has a problem in that its preservative action is not exhibited due to poor solubility in alkaline.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a fountain solution composition for lithographic printing which does not rot even when stored or used for a long period of time and has excellent printing aptitude and can realize stable lithographic printing. Is what you do.

[0006]

The invention according to claim 1 of the present application is characterized in that it contains a 1,2-benzisothiazolin-3-one compound and a water-miscible fungicide other than those described above. The present invention relates to a fountain solution concentrate for printing, and to an alkaline printing fountain solution obtained by diluting the fountain solution concentrate with water.

The 1,2-benzisothiazoline of the present invention
The 3-one compound mainly has a function as a preservative and is a compound represented by the following general formula.

[0008]

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(Wherein, R represents a hydrogen atom or a lower alkali group, X represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, etc., and n is an integer of 0 or 4). Among the 2-benzisothiazolin-3-one compounds, the one preferably used is 1,2-benzisothiazolin-3-one of the following structural formula.

[0010]

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The 1,2-benzisothiazolin-3-one compound is contained in the fountain solution concentrate of the present invention in an amount of 0.1 to 20% by weight,
Preferably, the content is 0.5 to 10% by weight.

The water-miscible fungicide of the present invention compensates for poor mold performance when a 1,2-benzisothiazolin-3-one compound is used alone. The water-miscible fungicide is water-soluble or dispersed in water in the form of fine particles, and includes, for example, "coatside" containing a benzimidazole-based compound as an active ingredient, which is marketed by Takeda Pharmaceutical Co., Ltd. , "Courtside 55D", "Courtside D", "Courtside DX", "Courtside S"
P "," Coatside SP-68 "," Sluroff 95 "containing an organic nitrogen sulfur compound as an active ingredient," Coatside H "containing an organic iodine compound as an active ingredient, and the like. The water-miscible fungicide is contained in the concentrated fountain solution at 0.1 to 10% by weight, preferably 0.5 to 3% by weight.

The fountain solution concentrate of the present invention has a pH of 10-1.
3.5 alkaline. Examples of the compound to be added to the fountain solution to make it alkaline include a water-soluble alkali metal silicate and a water-soluble alkali metal metaphosphate. The water-soluble alkali metal silicate has a function of keeping the dampening solution alkaline and facilitating uniform attachment of the dampening solution to the image area. As the water-soluble alkali metal silicate,
So-called water glass can be used. As such a compound, sodium metasilicate (Na ₂
SiO ₃ ), sodium orthosilicate (Na ₄ Si)
O ₄ ), sodium disilicate (Na ₂ Si ₂ O ₅ ), sodium tetrasilicate (Na ₂ Si ₄ O ₉ ) and the corresponding potassium salts.

The content of the water-soluble alkali metal silicate is
It is 0.1 to 10% by weight, preferably 0.5 to 5% by weight. The water-soluble alkali metal metaphosphate salt is (HP
O ₃ ) _{n is} an alkali metal salt such as sodium trimetaphosphate, sodium tetrametaphosphate, sodium polymetaphosphate, and the corresponding potassium salt. When used, the water-soluble alkali metal metaphosphate has a function of mixing in fountain solution to supplement metal ion impurities such as calcium ions. That is, calcium ions contained in the paper are mixed into the dampening water and react with the water-soluble alkali metal silicate to form a water-insoluble calcium silicate salt, which reduces the function of the dampening water. To prevent The content of the water-soluble alkali metal metaphosphate is 0.5 to 20% by weight, preferably 1 to 5% by weight.

In addition to the above compounds, alkali metal salts such as trisodium phosphate and tripotassium phosphate, a surfactant, an antifoaming agent and the like can be added to the fountain solution concentrate of the present invention. As the surfactant, dialkyl sulfosuccinate, alkyl sulfate, hydroxyalkanesulfonic acid, alkanesulfonic acid, dialkyl sulfosuccinic acid, linear alkylbenzene sulfonate, alkylnaphthalenesulfonic acid, polyoxyethylene alkyl sulfophenylethyl salt And the like, and nonionic surfactants such as polyoxyethylene alkylphenol, polyoxyethylene alkylphenyl ether, polyoxyethylene styrylphenyl ether, and polyoxyethylene polyoxypropylene alkyl ether. As the defoaming agent, a silicone-based emulsion type or solution type can be used. The fountain solution concentrate of the present invention can be diluted 100 to 300 times with water and used as a fountain solution having a pH of 9 to 11.

[0016]

EXAMPLES 97 parts by weight of tap water, 2 parts by weight of water-soluble sodium silicate, 1 part by weight of sodium phosphate, 0.05 parts by weight of nonionic water-soluble surfactant, 0.02 parts by weight of silicone defoamer Of a fountain solution (pH 13) consisting of According to the following formulation, 1,2-benzisothiazoline-3-
A fountain solution concentrate containing the ON compound and the water-miscible fungicide is prepared. As the 1,2-benzisothiazolin-3-one compound, a commercially available product having an active ingredient of 10% was used. As the water-soluble fungicide, a commercial product of Takeda Pharmaceutical Co., Ltd. was used.

COMPARATIVE EXAMPLE 1 95 parts by weight of a stock solution of fountain solution 5 parts by weight of a 1,2-benzisothizolin-3-one compound commercially available Example 1 94 parts by weight of stock solution of fountain solution 1,2-benzisothizoline-3-one On-compound commercial product 5 parts by weight Organic nitrogen-sulfur compound Fungicide Brand name "Sluoff 95" 1 part by weight Example 2 94 parts by weight of fountain solution 1,2-benzisothizolin-3-one compound commercial product 5 parts by weight Part Organic iodine compound Fungicide Brand name "Coatside H" 1 part by weight Example 3 Dampening solution 94 parts by weight 1,2-benzisothizolin-3-one compound commercial product 5 parts by weight Benzimidazole compound prevention Molding agent Trade name “Coatside D” 1 part by weight Further, as a comparative example, a fountain solution (pH 13) containing no 1,2-benzisothiazolin-3-one compound and a water-soluble fungicide was used. To. Comparative Example 2 100 parts by weight of stock solution of fountain solution

0.5 parts by weight of the fountain solution concentrate of each of the above Examples and Comparative Examples was diluted with 99.5 parts by weight of tap water to prepare fountain solutions for the following experiments. Experiment 1. Microbial Inhibition Test 5 parts by weight of the inoculum suspension shown below (collected from a spoiled dampening solution tank) were added to 100 parts by weight of dampening solution of each composition and mixed. Make a decision. The number of viable bacteria measured by the hygiene test method was as follows. Bacteria 1.0 × 10 ⁶ (cells / milliliter) Mold 1.0 × 10 ² (cells / milliliter) Test criteria are as follows Bacteria 1. Bacteria outbreak Number of live bacteria 1.0 × 10 ⁶ / ml or more 2. 2. Bacteria generation 1.0 × 10 ^{5 to} 1.0 × 10 ⁶ / ml ^3. Bacteria generation 1.0 × 10 ^{3 to} 1.0 × 10 ⁵ cells / ml 4. Slight occurrence of bacteria 1.0 × 10 ^{2 to} 1.0 × 10 ³ cells / ml No bacteria generation 1.0 × 10 ² pieces / ml or less Mold 1. Bacteria outbreak Number of live bacteria 1.0 × 10 ³ / ml or more 2. Bacteria are generated. 1.0 × 10 ^{2 to} 1.0 × 10 ³ / ml. ^3. Bacteria generation 1.0 × 10 ^{1 to} 1.0 × 10 ² cells / ml 4. Slight outbreak of bacteria 1.0 × 10 ¹ / ml or less Table 1 shows the results of the test.

[0019]

[Table 1]

Experiment 2 Printing test and microbial control results on actual machine Diluted with 0.5 parts by weight of the fountain solution concentrate of Examples and Comparative Examples and 99.5 parts by weight of tap water, and a printing test was performed under the following conditions as a fountain solution. Table 2 shows the results after one month of use. Printing machine: T-1000 keyless rotary press manufactured by Tokyo Kikai Seisakusho Co., Ltd. Printing ink: News King KL Black GT (manufactured by Toyo Ink Mfg. Co., Ltd.) Printing speed: 120,000 copies / hour Paper: newsprint paper dampening water mechanism: RYCO GRAPHIC spray nozzle method dampening water tank: RYCO GRAPHIC tank Water temperature 25 ° C to 29 ° C Temperature, humidity: 26 ° C to 31 ° C 60 to 80% RH Number of copies: 4.5 million copies

[0021]

[Table 2]

[0022]

The fountain solution of the present invention has a high preservative effect and does not decompose due to propagation of various bacteria, molds, bacteria and microorganisms even when used for a long period of time. Therefore, by using the fountain solution composition of the present invention as a fountain solution, printing failure due to decay of the fountain solution is eliminated, and a fountain solution tank,
It is easy to clean the piping and the watercraft of the printing press, and the work efficiency of the person engaged in offset printing is improved. Therefore, an improvement in the printing work environment and a reduction in fountain solution cost are achieved.

Claims (2)

(57) [Claims] 1. A printing dampening solution concentrate having a pH of 10 to 13.5, comprising a 1,2-benzisothiazolin-3-one compound and a water-miscible fungicide other than the above. 2. A fountain solution for alkaline printing obtained by diluting the fountain solution concentrate of claim 1 with water.