JP2673604B2 - Fountain solution composition for lithographic printing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fountain solution composition useful in an offset printing method for a lithographic printing plate.

(Prior art)

Lithographic printing is a printing method that skillfully utilizes the property that water and oil are not essentially mixed.The printing plate surface receives water and repels oil-based ink, and repels water and receives oil-based ink. The former forms a non-image area,
The latter forms the 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. Has the effect of increasing the ink receptivity.

Conventionally known desensitizing agents include:
Alkali metal or ammonium salts of dichromic acid, phosphoric acid or salts thereof, such as ammonium salts, gum arabic,
There is an aqueous solution to which a colloidal substance such as carboxymethyl cellulose (CMC) is added.

However, a fountain solution containing these desensitizing agents is
The non-image area of the plate has a drawback that it is difficult to uniformly get wet, which causes problems such as occasional stains on the printed matter and considerable skill in adjusting the supply amount of dampening water.

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 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 in the printing ink is easy. The amount of emulsified water decreases, and the transferability of printing ink to the blanket improves.
There are numerous advantages in terms of workability and the accuracy of the resulting print.

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. 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 solution to which this isopropyl alcohol is added is applied to offset printing using a normal water rod,
Since isopropyl alcohol evaporates on the roller and on the plate surface, there is a problem that the effect cannot be exhibited.

Furthermore, social interest in industrial pollution has increased in recent years, 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 from the viewpoint of safety and health. For this reason, a desensitizing agent not containing these has been desired.

In order to achieve these purposes, for example, Japanese Examined Patent Publication No. 55-250
No. 75, JP-B-55-19757 and JP-B-58-5797 describe compositions containing various surfactants, but when these are used as fountain solutions, In order to adjust the surface tension to 35 to 50 dynes / cm, it is necessary to make the surfactant concentration in the desensitizing agent considerably high. In actual lithographic printing, since the ink / water moves violently under the ink roll that rotates at the speed of light, the printing plate, and the fountain solution supply roll, water may adhere to the ink film, However, the combination of surfactants proposed above was not sufficient to completely eliminate these problems.
Further, there is a drawback that the fountain solution containing these surfactants easily foams during pumping or stirring.

By the way, 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. 4,278,467 describes n-hexoxyethylene glycol, n-hexoxydiethylene glycol, 2-ethyl-1,3-hexanediol, n-butoxyethylene glycol acetate, n-butoxydiethylene glycol acetate, 3
-A fountain solution containing at least one butoxy-2-propanol is described. JP-A-57-199693 discloses 2-ethyl-1,3-hexanediol and completely water-soluble propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, hexylene glycol, triethylene glycol, tetraethylene glycol. , A fountain solution containing at least one of tripropane glycol and 1,5-pentadiol is described. Since these fountain solution compositions do not contain isopropyl alcohol, they are advantageous in terms of safety and health,
It is hard to say that the non-image area is completely wet during printing on the PS plate using anodized aluminum as a substrate, especially when the high-speed printing is performed, the non-image area becomes dirty, and the halftone image area has a normal shape. However, there is a problem in that so-called entanglement of a halftone dot image portion occurs, which is large and uneven. Further, 2-ethyl-1,3-hexanediol is not sufficiently soluble in water and is disadvantageous in obtaining a high-concentration dampening water concentrate or a dampening water additive. .

Further, as a problem of the proposed dampening water, it is mentioned that the water supply roll used in the printing machine has different materials and water supply systems depending on the manufacturer of the printing machine, so that the water supply amount is different. Especially when a rubber-based roll is used as a water-based roll for drawing water, it is possible to print 3000-10,000 prints without problems, but
When 30,000 sheets are continuously printed, the water-based roll is contaminated with the ink and the amount of water drawn up is likely to change, which makes printing unstable and may cause stains on the printed matter.

[Problems to be solved by the invention]

Therefore, the present invention does not have the toxicity and drawbacks of the above-mentioned conventional dampening water, and can easily adjust the supply amount without requiring specialized skill in printing work, and further, the printing plate, In addition to preventing stains or buoy lining of printing plates (PS plates), especially using an electrochemically roughened support of anodized aluminum, other advantages,
It is an object of the present invention to provide a fountain solution composition for lithographic printing, which can easily obtain a high-quality printed matter having excellent fountain solution properties, such as being suitable for high-speed printing by an off-wheel printer.

[Means for solving the problem]

The present inventors have conducted intensive studies to achieve the above objects, and as a result, have found that the above objects can be easily achieved by using the fountain solution composition for lithographic printing described below, and arrived at the present invention. It is a thing.

That is, the present invention is a hydrophilic polymer having a film forming ability and
In a fountain solution composition for lithographic printing containing a pH buffer substance, an acrylate or Rf containing a fluoroaliphatic group (Rf group)
Group-containing methacrylate and polyoxyalkylene /
A copolymer with acrylate or methacrylate,
A lithographic printing fountain containing a compound in which the Rf group-containing acrylate or Rf group-containing methacrylate monomer unit is 7 to 40% by weight based on the weight of the copolymer, and the copolymer has a molecular weight of 3000 to 100000. It is a water composition. The fluoroaliphatic group is a fluoroaliphatic group (Rf group) having 3 to 20 carbon atoms, containing 40% by weight or more of fluorine, and having at least three terminal carbon atoms sufficiently fluorinated. Preferably there is.

Further, the molecular weight of the polyoxyalkyl group is preferably 300 to 3000. Further, if necessary, a foaming property can be suppressed by adding a dimethylsiloxane group or the like to the terminal.

In the present invention, the copolymer of Rf group-containing acrylate or methacrylate and polyoxyalkylene acrylate or methacrylate is preferably 0.0001% by weight to 5% by weight based on the total weight of the fountain solution composition at the time of use. , More preferably 0.0005 to 3% by weight.

Examples of the film-forming hydrophilic polymer substance that is an essential component of the present invention include gum arabic, starch derivatives (for example, dextrin, enzyme-degraded dextrin, hydroxypropylated enzyme-degraded dextrin, carboxymethylated starch, phosphate starch, octenyl succinate starch). ), Alginates, fibrin derivatives (eg, carboxymethyl cellulose, carboxyethyl cellulose, hydroxyethyl cellulose,
Natural products such as methylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, their glyoxal modified products, etc., and their modified products, polyethylene glycol and its copolymers, polyvinyl alcohol and its derivatives, polyvinylpyrrolidone, polyacrylamide and its copolymers. , Polyacrylic acid and copolymers thereof, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, polystyrene sulfonic acid and copolymers thereof, and the like. These polymer compounds may be used alone or as a mixture, and the concentration range thereof is preferably 0.005 to 1% by weight in the fountain solution composition at the time of use.

As the pH buffer substance, a water-soluble organic acid and / or inorganic acid or a salt thereof can be used, and these compounds are used for pH adjustment or pH buffering of the fountain solution composition, appropriate etching of the lithographic printing plate support or Effective in preventing corrosion. Preferred organic acids include, for example, citric acid, ascorbic acid, malic acid, tartaric acid, lactic acid, acetic acid, gluconic acid, hydroxyacetic acid, oxalic acid, malonic acid, levulinic acid, sulfanilic acid, p-toluenesulfonic acid, phytic acid, organic acids Phosphonic acid and the like. As the inorganic acid, for example, phosphoric acid,
Metaphosphoric acid, nitric acid, sulfuric acid and the like can be mentioned. Further, alkali metal salts, alkaline earth metal salts or ammonium salts of these organic acids and / or inorganic acids are preferably used. These organic acids, inorganic acids and / or salts may be used alone or It may be used as a mixture of more than one species.

The addition amount of the use group of the present invention to the fountain solution composition is 0.001 to
The range of 1% by weight is preferable, and it is preferable to use it in an acidic region having a pH value of 3 to 7, but it contains an alkali metal hydroxide, an alkali metal phosphate, an alkali metal carbonate, a silicate or the like. It can also be used in the alkaline range of pH 7-11.

The fountain solution composition of the present invention may contain a solvent, a wetting agent, a bactericide, an antifoaming agent, and the like, if necessary. Specific examples of the wetting agent include polyol, glycol ether,
Examples include alcohols and surfactants. For example, polyols and glycol ethers are 2-ethyl-1,3-
Hexanediol, hexyl cellosolve, hexyl carbitol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol,
Dipropylene glycol, tripropylene glycol,
Hexylene glycol, tetraethylene glycol, 1,
5-pentanediol, glycerin, diglycerin, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, propylene glycol monomethyl ether,
Dipropylene glycol monomethyl ether, ethylene glycol monopropyl ether, diethylene glycol monopropyl ether, propyllen glycol monopropyl ether, dipropyllen glycol monopropyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol mono Butyl ether, triethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, polypropylene glycol (molecular weight 200 to 10,000,
Ethylene glycol isobutyl ether, diethylene glycol monoisobutyl ether, ethylene glycol monoallyl ether, ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, ethylene oxide adduct of 2-ethyl-1,3-hexanediol, acetylene glycol and its ethylene oxide adduct, etc. Is mentioned.

As the alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, n-amyl alcohol,
Benzyl alcohol and the like.

Examples of the surfactant include anionic surfactants such as fatty acid salts, abietic acid salts, hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinates, linear alkylbenzenesulfonates,
Branched-chain alkylbenzene sulfonate, alkylnaphthalene sulfonate, alkylphenoxy polyoxyethylene propyl sulfonate, polyoxyethylene alkyl sulfophenyl ether salt, N-methyl-N-oil taurine sodium salt, N-alkyl sulfosuccinic acid monoamide Sodium salt, petroleum sulfonate, sulfated castor oil, sulfated tallow oil, sulfate ester salt of fatty acid alkyl ester, alkyl sulfate ester salt, polyoxyethylene alkyl ether sulfate ester salt, fatty acid monoglyceride sulfate ester salt, polyoxyethylene alkyl Phenyl ether sulfate ester salt, polyoxyethylene styryl phenyl ether sulfate ester salt, alkyl phosphate ester salt, polyoxyethylene alkyl ether phosphate ester salt, poly Alkoxy alkylphenyl ether phosphate ester salt, a styrene - partially saponified maleic anhydride copolymer, olefin - partially saponified maleic anhydride copolymer, naphthoquinone Allen sulfonate formalin condensates and the like.

Of these, dialkyl sulfosuccinates, alkyl sulfates and alkyl naphthalene sulfonates are particularly preferably used.

As the nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene polystyryl phenyl ether, polyoxyethylene polyoxypropyl alkyl ether, glycerin fatty acid partial ester,
Sorbitan fatty acid partial ester, pentaerythritol fatty acid partial ester, propylene glycol mono fatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid partial ester, Examples include polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial ester, fatty acid diethanolamide, N, N-bis-2-hydroxyalkylamine, polyoxyethylene alkylamine, triethanolamine fatty acid ester, trialkylamine oxide. . Among them, polyoxyethylene alkyl phenyl ether, polyoxyethylene-polyoxypropylene block polymer and the like are preferably used.

Furthermore, examples of the cationic surfactant include an alkylamine salt, a quaternary ammonium salt, a polyoxyethylene alkylamine salt, and a polyethyleneamine derivative.

These wetting agents can be used alone or in combination of two or more. The preferred range of use is 0.03 to 5% by weight, more preferably 0.05 to 3% by weight, based on the total weight of the fountain solution composition at the time of use.

Specific examples of preservatives that can be suitably used in the present invention include:
Phenol or a derivative thereof, formalin, imidazole derivative, sodium dehydroacetate, 4-isothiazolin-3-one derivative, benzotriazole derivative, amiding anidine derivative, quaternary ammonium salts, pyridine, quinoline, derivatives such as guanidine, diazine, triazole derivative, Oxazole, oxazine derivatives and the like. The preferred addition amount is, with respect to bacteria, fungi, yeast, etc., an amount that exerts a stable effect, and the amount of the fountain solution composition at the time of use varies depending on the types of bacteria, fungi, and yeast. The range of 1% by weight is preferable, and it is preferable to use two or more kinds of preservatives together so as to be effective against various molds and bacteria.

Examples of the defoaming agent that can be preferably used in the present invention include polyglycol-based and silicon-based defoaming agents that are well known. Silicon-based compounds include emulsified type and one-liquid type, and both of them are effective in a small amount, and therefore silicon-based compounds are preferable. The use amount of the antifoaming agent is suitably 0.001 to 0.3% by weight based on the total weight of the fountain solution composition at the time of use.

Further, a chelating compound may be added to the fountain solution composition of the present invention, if necessary, in addition to the above compounds. Usually, the fountain solution composition is used after being appropriately diluted by adding tap water, well water and the like. The calcium ions and the like contained in the diluted tap water or well water adversely affect the printing, and may cause the printed matter to be easily stained. . 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,
Organic salts such as aminotri (methylenephosphonic acid), potassium salt and sodium salt thereof, and phosphonoalkanetricarboxylic acids can be mentioned. Instead of the sodium salt or potassium salt of the above chelating agent, a salt of an organic amine is also organic. These chelating agents are selected from those which are stably present in the fountain solution composition and do not inhibit printability. The amount added to the fountain solution composition at the time of use is 0.001 to 5% by weight, preferably 0.005 to 1% by weight.

Further, various coloring agents, rust preventives and the like can be added to the fountain solution composition of the present invention. For example, food coloring agents and the like can be preferably used as the coloring agent. For example, CI No. 19140 and 15985 as yellow pigments and CI No. 19 as red pigments.
16185, 45430, 16255, 45380, 45100, CI No. 42640 for purple pigment, CI No. 42090, 7301 for blue pigment
5, green dyes such as CI No. 42095 can be mentioned. Benzotriazole, tolyltriazole, benzimidazole, and 2-mercaptobenzimidazole are preferably used as the rust preventive agent.

Further, an anti-oxidation stain preventing agent for non-image areas such as magnesium nitrate, zinc nitrate and sodium nitrate can be contained.

As described above, it is economical and preferable to produce the fountain solution composition of the present invention as a concentrated solution, and to dilute the fountain solution composition with tap water, well water, etc. several tens to several hundred times.

The lithographic printing plate in which the fountain solution composition of the present invention is used is a photosensitive lithographic printing plate (PS plate), a multi-layer metal plate such as planographic intaglio, bimetal, trimetal, direct drawing master, electrophotographic lithographic printing plate, etc. Various lithographic printing plates.

〔The invention's effect〕

When the fountain solution composition of the present invention is used, it is possible to perform printing without background stains, oxidative stains, roller baldness due to the excessive emulsification phenomenon of ink and water, and reduction of ink density, and excellent dot shape. It is possible to obtain excellent printed matter, improve printing efficiency, and improve productivity. Particularly when used in a continuous water supply type printing machine typified by the Dahlgren method, a good printed matter can be obtained without using isopropyl alcohol, but a small amount, for example, 1 to 15% of isopropyl alcohol is used in combination. There is no problem in print quality.

The fountain solution composition of the present invention has good wettability with respect to a lithographic printing plate and prevents stains and blinding of the non-image area of the printing plate. Moreover, the amount of waste paper is greatly reduced, which is advantageous from the economical aspect.

Further, the fountain solution composition for lithographic printing according to the present invention can be applied to all water supply systems of a printing machine, and water can be stably supplied, and a stable printer can be obtained. In addition, there is almost no concern about work environment pollution or fire, and there is no need for local exhaust equipment. Moreover, it is a dampening water with excellent continuous stability for metering stains and ink bleed.

〔Example〕

Next, the present invention will be described more specifically by way of examples.
In addition,% indicates weight% unless otherwise specified.

Example 1 Pure water 76.8% 1 ammonium citrate 2 〃 disodium phosphate 3 〃 gum arabic (14 ° Be) 18 〃 4-shisothiazolin-3-one compound 0.2〃 An aqueous solution of the above composition was prepared as a desensitizing agent. And then with water 10
After diluting 0 times, 0.3% by weight of ethylene oxide 1 to 4 mol adduct of 2-ethyl-1,3-hexanediol, 0.6% by weight of propylene glycol monoisopropyl ether and N-butylperfluorooctanesulfonamide ethyl acrylate [CH ₂ = CHCOOCH ₂ CH ₂ (C ₄ H ₉ ) NSO ₂ C ₈ F
₁₇ , monomer ratio 40% by weight] and poly (oxyethylene)
Acrylate [CH ₂ = CHCOOC ₃ H ₄ O _n H, monomer ratio 6
0% by weight] of a copolymer (molecular weight: 15000) was added by 0.03% by weight to prepare fountain solution, which was set in an offset printing machine Heidel SORM (Heidel Printing Co., Ltd.) (Calcolor water supply device).

On the other hand, as a printing plate, FPS-II (Fuji Photo Film Co., Ltd.'s anodic oxidation multi-grain type positive P plate) was exposed to light and PS automatic processor 800E II, positive developer DP-4
(Diluted 8 times with water), Positive Finisher FP (2 with water)
It was developed and gummed using (double dilution) (both manufactured by Fuji Photo Film Co., Ltd.) and mounted on the above printing machine, and the characteristics of the fountain solution were evaluated for the following items.

a. Metering roll dirt: Investigate the degree of dirt of ink adhering to the watering metering roll.

good. ○ Somewhat inferior. △ Inferior. X b. Bleedability: When the ink (Dainippon Ink & Co., Inc. Apex G Red S) was printed on 5000 and 10000 sheets, the printing machine was stopped and the ink in the image area bleeded into the non-image area. Find out how much you have.

Almost no bleeding. ○ Some bleeding. △ Many bleeds. X c. Emulsifiability: After printing 10,000 sheets, check the emulsification state of the ink on the ink kneading roll.

good. ○ Somewhat bad. △ Bad. X d. Continuous stability: Using fresh water as the dampening solution, print 10,000 sheets, find the amount of dampening solution that does not cause stains (minimum pumping volume), and apply various dampening solutions to this minimum pumping volume. Is used to perform printing, and the determination is made based on the number of printed sheets until stains on the printed matter occur.

10,000 sheets or more. ○ 10,000-3000 sheets. △ Less than 3000 sheets. × As a result of testing the suitability of the fountain solution of this example,
(A) dirt on metering roll, (b) bleeding,
Excellent prints were obtained, which were excellent in both (c) emulsifying property and (d) continuous stability (all were good).

The fountain solution of this example was able to print comfortably without feeling any odor.

Example 2 Pure water 84% Diammonium citrate 5 〃 Phosphoric acid 3 〃 Hydroxypropylcellulose 8 〃 Formalin (37%) 2 〃 Prepare an aqueous solution of the above composition as a desensitizing agent, and add 10
After diluting 0 times, ethylene glycol monobutyl ether 1% by weight, octylene glycol 0.1% by weight, N
- propyl perfluorooctane sulfonamide ethyl acrylate _{[CH 2 = CHCOOCH 2 CH 2 (} C 3 H 7) NO 2 SC 8 F 17, the monomer ratio of 30 wt%] and polyoxyethylene acrylate _{[CH 2 = CHCOOC 2 H 4 O} n H, monomer ratio 60% by weight)
Dimethyl siloxane (monomer ratio 10
Wt%) to obtain the compound (molecular weight 18000)
0.05% by weight was added to make fountain solution, and the pH was adjusted to 5.5 with NaOH.

The offset printing machine was set on a Komori Lithrone (equipped with Komori Matic) printing machine, and a test was conducted in the same manner as in Example 1. As a result, all of the evaluation items (a) to (d) were good, and a good printed matter was obtained. I was able to get it.

Claims (1)

(57) [Claims] 1. A fountain solution composition for lithographic printing, comprising a hydrophilic polymer having a film-forming ability and a pH buffer substance, wherein an acrylate containing a fluoroaliphatic group (Rf group) or
A copolymer of Rf group-containing methacrylate and polyoxyalkylene / acrylate or methacrylate, wherein the Rf group-containing acrylate or Rf group-containing methacrylate monomer unit is 7 to 40% by weight based on the weight of the copolymer. And a fountain solution composition for lithographic printing, comprising a compound having a molecular weight of 3,000 to 100,000.