JP2002187375A - Damping water composition for planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damping water composition for a planographic printing plate capable of being used in place of an isopropyl alcohol type composition, comfortable and safe from an aspect of work environment, excellent in printing stability, developing good and stable printability under the condition of a member rotating at a high speed, developing printability good in stability with respect to various inks and capable of obtaining excellent printed matter. SOLUTION: The damping water composition for the planographic printing plate contains at least one kind of a component selected from the group consisting of polyvinyl pyrrolidone, n-butyl alcohol, isobutyl alcohol, see-butyl alcohol and tert-butyl alcohol.

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 dampening solution wets the non-image area to enlarge the surface chemistry difference between the image area and the non-image area, thereby increasing the ink repellency of the non-image area and the ink receptivity of the image area. Done. Examples of the fountain solution generally known in the art include alkali metal salts or ammonium salts of dichromic acid, phosphoric acid or salts thereof, such as ammonium salts, gum arabic, and colloidal substances such as carboxymethylcellulose (CMC). There is an aqueous solution 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 this 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. . Therefore, it is safe in terms of environmental hygiene, it can easily adjust the supply amount without requiring professional skills in printing work, and it not only prevents the printing plate from being stained, but also suitable for high-speed printing Excellent fountain solution properties such as
There is a need for a fountain solution composition for lithographic printing plates that can provide high quality printed matter.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fountain solution composition which is comfortable and safe in a working environment and which is excellent in printing stability and which can be replaced with isopropyl alcohol. Also, a lithographic printing plate that exhibits good and stable printability even under the condition of a member rotating at a high speed, and exhibits good printability with stability for various inks and can obtain excellent printed matter. An object of the present invention is to provide a fountain solution composition.

[0006]

Means for Solving the Problems The inventors of the present invention have repeatedly studied on a fountain solution composition for lithographic printing plates to achieve the above object, and as a result, have found that polyvinyl pyrrolidone, n-butyl alcohol, isobutyl alcohol, sec. By using in combination with at least one selected from -butyl alcohol and tert-butyl alcohol, it has been found that an excellent fountain solution composition having good wettability on a roller and a plate surface can be obtained, and the present invention It was completed. Accordingly, the present invention provides polyvinylpyrrolidone, n-butyl alcohol,
Isobutyl alcohol, sec-butyl alcohol and tert
A fountain solution composition for a lithographic printing plate comprising at least one selected from the group consisting of -butyl alcohol.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the fountain solution composition for a lithographic printing plate of the present invention will be described in detail. In general, when a fountain solution composition is used on a commercial basis, it is generally concentrated and commercialized. When used, such a concentrated solution is appropriately diluted and used. The contents and addition amounts of the various components mentioned below in this specification are based on the total weight of the fountain solution composition at the time of use, unless otherwise specified.

The polyvinylpyrrolidone contained in the fountain solution composition of the present invention means a homopolymer of vinylpyrrolidone. Polyvinylpyrrolidone has a molecular weight of 200-3,00
000 is suitable, preferably 300-500,00
0, more preferably 300 to 100,000. Particularly preferably, it is 300 to 30,000. These polyvinylpyrrolidones can be used alone or in combination of two or more having different molecular weights. When the molecular weight exceeds 100,000, it tends to cause blinding during printing and a roller strip of an ink roller of a printing press. Therefore, use a low molecular weight polyvinylpyrrolidone, for example, a vinylpyrrolidone oligomer having a degree of polymerization of 3 to 5 in combination. Can be. Commercial products can be used as such polyvinylpyrrolidone. For example,
ISP K-15, K-30, K-60, K-9
Various grades such as 0 and K-120 can be used. The content of polyvinylpyrrolidone in the fountain solution composition of the present invention is suitably from 0.001 to 0.3% by mass, preferably from 0.0 to 0.3% by mass, based on the total mass of the fountain solution composition.
0.5 to 0.2% by mass.

The fountain solution composition of the present invention further contains at least one selected from the group consisting of n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol and tert-butyl alcohol. Of these butyl alcohols, tert-butyl alcohol can be preferably used. In the fountain solution composition of the present invention, the content of at least one selected from the group consisting of n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol and tert-butyl alcohol is based on the total weight of the fountain solution composition. The amount is suitably from 0.1 to 3.0% by mass, preferably from 0.5 to 2.0% by mass.

The fountain solution composition of the present invention may further contain the following. (a) Auxiliary agent for improving wettability (b) Water-soluble polymer compound other than polyvinylpyrrolidone (c) pH adjuster (d) Odor masking agent (e) Other (preservative, chelating agent, coloring agent,
Rust inhibitor, defoamer, etc.)

(A) As an auxiliary agent for improving the wettability, a surfactant or another solvent can be used. Among surfactants, for example, anionic surfactants include fatty acid salts, abietic salts, hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinates, straight-chain alkylbenzenesulfonates, and branched-chain alkylbenzenesulfones Acid salts, alkyl naphthalene sulfonates, alkyl phenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfenyl ether salts, N-methyl-N-oleyl taurine sodium salts, N-alkyl sulfosuccinic 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 acids Noglyceride sulfates, polyoxyethylene alkyl phenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, styrene -Partially saponified products of maleic anhydride copolymer, partially saponified products of olefin-maleic anhydride copolymer, and naphthalenesulfonic acid formalin condensates. Of these, dialkyl sulfosuccinates, alkyl sulfates and alkyl naphthalene sulfonates are particularly preferably used.

Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, 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, polyoxyethylene-polyoxypropylene block polymers, trialkylamine oxides, and the like. In addition, a fluorine-based surfactant and a silicon-based surfactant can also be used. Among them, polyoxyethylene alkyl phenyl ethers, polyoxyethylene-polyoxypropylene block polymers and the like are preferably used. Further, a surfactant such as a silicon derivative or a fluorine derivative may also be used. When a surfactant is used, the content thereof is 1.0% by mass or less, preferably 0.001 to 0.5% by mass in view of foaming.
Is appropriate. Also, two or more kinds can be used in combination.

Other auxiliary agents include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, and tetraethylene glycol monoethyl ether. Ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monopropyl ether, triethylene glycol monopropyl ether, tetraethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, triethylene glycol mono Isopropyl A Le, tetraethylene glycol monoisopropyl ether,

Ethylene glycol monobutyl ether,
Diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, triethylene glycol monoisobutyl ether, tetraethylene glycol monoisobutyl ether, ethylene glycol monotertiary butyl ether, diethylene glycol mono Tertiary butyl ether, triethylene glycol monotertiary butyl ether, tetraethylene glycol monotertiary butyl ether,

Propylene glycol monomethyl ether, dipropylene 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 monomethyl Propyl ether, dipropylene glycol monopropyl ether, tripropylene 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, dipropylene glycol monoisobutyl ether, tripropylene glycol monoisobutyl ether, propylene glycol monotertiary butyl ether, dipropylene glycol monotertiary butyl ether, tripropylene glycol monotertiary butyl ether, molecular weight 200 to 1000 polypropylene glycols and their monomethyl, monoethyl, monopropyl, monoisopropyl and monobutyl ethers;

Propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol and pentapropylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, butylene glycol, hexylene glycol,
Examples include 2-ethyl-1,3-hexanediol, 3-methoxy-3-methyl-butanol and 3-methoxy-butanol, glycerin, diglycerin, polyglycerin, trimethylolpropane, and the like. These solvents may be used alone or in combination of two or more. Generally, these solvents are present in amounts of 0.1 to 0.1 based on the total weight of the fountain solution composition.
It is suitable to use in the range of 3% by mass, preferably 0.3%.
~ 2% by mass.

The (b) water-soluble polymer compound used in the fountain solution composition of the present invention includes, for example, gum arabic, starch derivatives (eg, dextrin, enzymatically decomposed dextrin,
Natural products such as hydroxypropylated enzyme-decomposed dextrin, carboxymethylated starch, phosphate starch, octenylsuccinated starch), alginate, and fibrin derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose) and modified products thereof, polyethylene glycol and The copolymer, polyvinyl alcohol and its derivative, polyacrylamide and its copolymer, polyacrylic acid and its copolymer, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, polystyrene Synthetic products of sulfonic acid and copolymers thereof are mentioned. The content of the water-soluble polymer compound is 0.0001 to 0.1% by mass based on the fountain solution composition.
And more preferably 0.0005 to 0.05% by mass.

(C) p used in the fountain solution composition of the present invention
As the H regulator, water-soluble organic and / or inorganic acids or salts thereof can be used.
It is effective for H adjustment, pH 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, oxalic acid, malonic acid, levulinic acid, sulfanilic acid, p
-Toluenesulfonic acid, phytic acid, organic phosphonic acid and the like. Examples of the inorganic acid include phosphoric acid, nitric acid, sulfuric acid, and polyphosphoric acid. Further, these organic acids and / or
Or alkali metal salts of inorganic acids, alkaline earth metal salts or ammonium salts, organic amine salts are also suitably used,
These organic acids, inorganic acids and / or salts thereof may be used alone or as a mixture of two or more. The amount of these pH adjusters added to the fountain solution composition of the present invention is preferably in the range of 0.001 to 0.3% by mass, 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.

(D) Examples of the odor masking agent include esters which are conventionally known for use as fragrances. For example, there is one represented by the following general formula (I). R ¹ —COOR ² (I) In the compound of the general formula (I), R ¹ is a group having 1 carbon atom.
To 15 alkyl groups, alkenyl groups or aralkyl groups,
Alternatively, it is a phenyl group. In the case of an alkyl group or an alkenyl group, the number of carbon atoms is preferably 4 to 8.
When R ¹ represents an alkyl group, an alkenyl group or an aralkyl group, they may be linear or branched. As the alkenyl group, one having one double bond is particularly suitable. Examples of the aralkyl group include a benzyl group and a phenylethyl group. Incidentally, one or more hydrogen atoms of the alkyl group, alkenyl group or aralkyl group represented by R ¹ or phenyl group may be substituted with a hydroxyl group or an acetyl group. R ² is an alkyl group having 3 to 10 carbon atoms, an aralkyl group or a phenyl group, which may be linear or branched. In the case of an alkyl group, it preferably has 3 to 9 carbon atoms. Examples of the aralkyl group include a benzyl group and a phenylethyl group.

Specific examples of (d) odor masking agents that can be used include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid,
2-ethylbutyric acid, valeric acid, isovaleric acid, 2-methylvaleric acid, hexanoic acid (caproic acid), 4-methylpentanoic acid (isohexanoic acid), 2-hexenoic acid, 4-pentenoic acid, heptanoic acid, 2- Methylheptanoic acid, octanoic acid (caprylic acid), nonanoic acid, decanoic acid (capric acid),
Esters of 2-decenoic acid, lauric acid or myristic acid. In addition, there are acetoacetic esters such as benzyl phenylacetate, ethyl acetoacetate and 2-hexyl acetoacetate. Among them, preferred are n-pentyl acetate, isopentyl acetate, n-butyl butyrate, n-pentyl butyrate and isopentyl butyrate, with n-butyl butyrate, n-pentyl butyrate and isopentyl butyrate being particularly preferred. The content of these odor masking agents (d) in the dampening solution composition is suitably 0.0001 to 10% by mass, more preferably 0.001 to 1% by mass, based on the total mass of the dampening solution composition. %. By using these, the working environment can be further improved. Also. Vanillin, ethyl vanillin and the like may be used in combination.

The preservative (e) used in the fountain solution composition of the present invention includes phenol or a derivative thereof, formalin, an imidazole derivative, sodium dehydroacetate,
-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, bromonitro alcohol-based bromonitro Propanol, 1,1-dibromo-1
-Nitro-2-ethanol, 3-bromo-3-nitropentane-2,4-diol and the like. 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. The range is preferably 0.0% by mass, and it is preferable to use two or more preservatives which are effective against various molds, bacteria and yeasts.

The fountain solution composition of the present invention further comprises (e)
Chelating agents can be added. The fountain solution composition is usually prepared by diluting the concentrated fountain solution composition with tap water, well water and the like at the time of use.In this case, calcium ions contained in the diluted tap water or well water are used. May adversely affect printing and may cause the printed matter to be easily stained. In such a case, the above-mentioned drawback can be solved by adding a chelating agent. Preferred chelating agents 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 , Its potassium salt, its sodium salt;
Nitrilotriacetic acid, its sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, its potassium salt, its sodium salt; organic phosphonic acids such as aminotri (methylenephosphonic acid), its potassium salt, its sodium salt, etc. Noalkane tricarboxylic acids can be mentioned. Instead of the sodium or potassium salts of the above-mentioned chelating agents, salts of organic amines are also effective. These chelating agents are selected from those which are stably present in the fountain solution composition at the time of use and do not inhibit printability. The content of the chelate compound in the fountain solution composition at the time of use is suitably 0.001 to 0.1% by mass, and is preferably
It is 0.005 to 0.05% by mass.

As the (e) colorant used in the fountain solution composition of 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. As the rust preventive (e) used in the fountain solution composition of the present invention, for example, benzotriazole, 5-methylbenzotriazole, thiosalicylic acid,
Benzimidazole and its derivatives are exemplified. As the (e) antifoaming agent used in the fountain solution composition of the present invention, a silicon antifoaming agent is preferable, and among them, any of an emulsifying dispersion type and a solubilizing type can be used.

The balance of the fountain solution composition of the present invention is water. A fountain solution composition is generally concentrated and commercialized for commercial use. Therefore, a concentrated humidified water composition can be obtained as an aqueous solution in which the above-mentioned various components are dissolved using water, preferably demineralized water, that is, pure water. When such a concentrated solution is used, it is usually diluted about 10 to 200 times with tap water, well water or the like at the time of use to obtain a fountain solution composition at the time of use.

[0025]

The fountain solution composition for a lithographic printing plate of the present invention comprises:
A uniform film of dampening solution can be stably supplied to the chrome roller and rubber roller used in the dampening solution supply device of the continuous water supply system and to the plate surface of the lithographic printing plate.
In addition, the working environment is comfortable and safe. By using polyvinylpyrrolidone, the amount of other organic solvents can be reduced, so that evaporation due to the organic solvents can be reduced, leading to improvement in printing stability. The fountain solution composition of the present invention can exhibit good wettability on a roller and on a plate surface even under the condition of a member rotating at a high speed, so that a printed matter excellent in stability can be obtained. In particular, it is possible to improve printability when using a metal pigment ink or a UV ink, which is conventionally difficult to print with a fountain solution. Because it can be used stably for a long period of time, it leads to an improvement in productivity.

[0026]

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

Examples 1 to 5 and Comparative Examples 1 and 2 Various compositions were prepared according to the compositions shown in Table 1. The unit is gram and water was added to make up to 1000 ml. All are concentrated types and are diluted when used.

[0027]

[Table 1]

The compositions of Examples 1 to 5 and Comparative Examples 1 and 2 prepared as described above were each diluted 40-fold with pseudo hard water having a hardness of 400 ppm, and the pH was adjusted to 4.8 to 5.3. The composition was adjusted with NaOH / phosphoric acid (85%) so as to be close to each other, and subjected to a printing test as a fountain solution composition actually used. The printing press uses a Heidel MOV (Alcolor water supply device), a cyan ink of the name Toyo Ink Co., Ltd. Hi-Echo, and a V plate manufactured by Fuji Photo Film Co., Ltd. as a plate to be used.
The following printing test was carried out using a plate made of PS under standard conditions. The results are shown in Table 2 below.

(A) Printing Stable Width The printable width was observed on a water supply scale 1 to 100 (also a measure of the number of rotations of a water supply roller) of a printing machine. ○ ‥‥ 40 to 100 △ ‥‥ 60 to 100 × ‥‥ 80 to 100 ×× ‥‥ Cannot be printed (b) Stability of water supply roller 10,000 sheets per day were continuously printed for three days. Dirt on the water supply roller on the first day (after printing 10,000 sheets), the second day (after printing 20,000 sheets), and the third day (after printing 30,000 sheets) (whether the water film on the roller can be uniformly cleaned) Was observed). ○ ‥‥ Almost no dirt △ ‥‥ Some dirt can be seen × ‥‥ Dirt

(C) Bleeding property After printing 5,000 sheets and 10,000 sheets, the operation of the printing press was stopped, and the extent to which the ink in the image area had spread to the non-image area was examined. ○ ‥‥ Almost no bleeding △ ‥‥ Slight bleeding × ‥‥ Many bleeding (d) Metal pigment ink, UV ink printing stability Ink used: Megami Ink Co., Ltd. Gold ink (blue mouth),
Best cure red (UV ink) Toka Dye Co., Ltd. ○ ‥‥ Good for printing 5000 sheets △ ‥‥ Ink stain on blanket (washing the plate once) × ‥‥ Ink stain around 1000 sheets (on the way, plate and blanket) (Wash twice)

[0031]

[Table 2] -: Test not possible

The fountain solution composition according to the present invention was excellent in all test items, a good printed matter was obtained, and the suitability for the fountain solution was also excellent.

Claims (1)

[Claims] 1. A fountain solution for lithographic printing plates, comprising polyvinylpyrrolidone and at least one member selected from the group consisting of n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol and tert-butyl alcohol. Composition.