JPH0250877B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dampening solution composition that can be used in combination with a lithographic printing ink containing a metal salt of a fatty acid to accelerate the drying of the lithographic ink without impairing its printability. .

Oxidation polymerization type inks used in lithographic printing generally contain drying oil, resin, mineral oil, etc. as a vehicle. When such lithographic printing ink dries, part of the mineral oil and drying oil penetrates into the paper, leaving a slightly viscous film on the paper (set), and then unsaturation in the drying oil The process progresses as the fatty acid ester absorbs oxygen from the air and undergoes oxidation and polymerization reactions to harden. Such drying of the ink by oxidative polymerization proceeds using a metal salt of a fatty acid contained in the ink as a catalyst. However, the problem with such lithographic printing inks is that they take a long time to dry, and especially when the printing paper is piled up, air circulation is blocked, which takes longer to dry and causes set-off. , blocking, and other extremely undesirable phenomena. Furthermore, if the oxidation drying is insufficient, the coating will be weak during post-processing such as cutting, and this will cause scratches and stains. For this reason, in normal sheet-fed printing, methods such as uneconomical slatting or dispersing spray powder (starch) at the paper discharge section of the printing machine are used. However, with the method of dispersing spray powder,
There are disadvantages in that the working environment deteriorates and the smoothness of the printed surface is lost. On the other hand, in recent years, attempts have been made to prevent set-off by applying an aqueous overcoating liquid on a wet ink coating for the purpose of complete stacking without dispersing spray powder. However, although this method has the effect of reducing set-off, the underprint wet ink film covered with the aqueous overcoating liquid is further cut off from oxygen supply, and the drying time is reduced by the aqueous overcoating liquid. It may be slower, but not faster than if it were not applied.

On the other hand, in lithographic printing, taking advantage of the mutually repellent property of water and ink, dampening water and ink are brought into contact with the plate, and ink is applied only to the image area for printing. This dampening water may be acidic, alkaline or neutral, and these dampening waters are expected to have effects similar to those of the aqueous overcoating liquid described above. In fact, alkaline dampening water has been found to have the effect of promoting dryness;
It has drawbacks such as excessive emulsification with ink and poor ink transfer, so it cannot be put to practical use except in low acid value inks such as newspaper printing inks. Another method is to add cobalt acetate to the dampening water and use the catalytic action of the cobalt ions to accelerate the drying of the ink, but this method also emulsifies the dampening water and ink, similar to when using alkaline dampening water. The disadvantage is that the fluidity and transferability are reduced.

An object of the present invention is to provide a dampening solution composition that can accelerate ink drying without causing the above-described poor ink transfer.

As a result of intensive research for the above-mentioned purpose, the present inventors found that
It has been found that it is extremely effective to include a polydentate ligand compound in the dampening solution, which has the effect of promoting drying by oxidative polymerization of a lithographic ink containing a metal salt of a fatty acid.

The dampening water composition for lithographic printing of the present invention is based on the above-mentioned knowledge, and more specifically, it is characterized by containing a polydentate ligand compound, and is characterized by containing an oxidative polymerization type ink containing a metal salt of a fatty acid. They should be used in combination.

It is known that the above-mentioned polydentate ligand compounds form a more effective catalyst system for oxidative polymerization reactions than a metal salt of a fatty acid alone. Therefore, it is conceivable to add this to the lithographic printing ink together with a metal salt of a fatty acid. However, in the present invention, the reason why the polydentate ligand compound is included in the dampening solution without taking such measures is that the polydentate ligand compound and the metal fatty acid salt are included in the ink. This is because there are recognized inconveniences.

(b) Some types of ink, such as yellow ink, undergo discoloration during long-term storage.

(b) Depending on the application, it may not be necessary to accelerate drying by oxidative polymerization to that extent, but it is uneconomical to uniformly include a polydentate ligand compound.

(c) Since the amount added is extremely small, about 0.01% of the ink, extremely accurate measurement is required, making it difficult to mix the ink.

Also, when a polydentate ligand compound is included in the dampening solution,
There is also the advantage that polydentate ligand compounds are more effective in aqueous media and do not require additional steps such as the application of an aqueous overcoating liquid as described above.

The present invention will be explained in more detail below. In the following description, both "%" and "part" are based on weight.

Examples of the polydentate ligand compound used in the present invention include hexahydrodiazine, 1,2-diazine, 1,3-diazine, 1,4-diazine, phthalazine, bipyridine, 2,2'-dimethylbipyridine, 2,2'-diethylbipyridine, 5,5'-dimethyl-2,2'-bipyridine, 2,3-dimethyl-
1,4-diazine, 2,3-diethyl-1,4-
Diazine, terpyridine, 2,2″-dimethylterpyridine, orthophenanthroline, orthophenanthroline hydrochloride, 3-carboxy-4-hydroxy-5-methoxy-1,10-phenanthroline, triazine, 2,2 '-Piquinoline, 2-oxyazobenzene, salicylaldehyde, 8-oxyquinoline, phthalonitrile, 1,3-diphenylguanidine, dimethylglyoxime, salicylaldoxime, dithiodiogizamide, triethylenetetramine, N,N', N″,N-tetrasalicylidenetetraaminomethylethane, N,N′-
Examples include bis(salicylidene)ethylenediamine, chlorophyll, hematoporphyrin, and the like.

Add these polydentate ligand compounds to dampening water at 0.01~
The dampening water composition of the present invention can be obtained by containing it in a proportion of 1%, preferably 0.02 to 0.2%.
If it is less than 0.01%, its effectiveness is poor, and if it is added in excess of 1%, it may act rather as a drying inhibitor.

The fountain solution to which the polydentate ligand compound is added is not particularly different from those conventionally used. That is, tap water itself, or inorganic acids such as phosphoric acid including orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, and polyphosphoric acid, silicic acid including metasilicic acid, orthosilicic acid, and pyrosilicic acid, or their alkali metal salts or ammonium salts. Add water-soluble salts, viscosity-imparting agents such as gum arabic, polysaccharides such as carboxymethylcellulose, polyhydric alcohols such as glycerin and ethylene glycol, and surfactants to make the mixture acidic or alkaline as necessary.
A pH-adjusted one is used.

In order to include a polydentate ligand compound in dampening water, it is preferable to dissolve it in advance in a hydrophilic solvent of about 1 to 5 times the amount to form a solution, and then stir and mix the solution with dampening water. . Examples of hydrophilic solvents used for this purpose include methanol, ethanol, propanol, butanol, and methyl cellosolve.
Most preferred are ethanol, isopropyl alcohol and butyl cellosolve.

The lithographic printing ink which is to be printed and whose drying is to be promoted in combination with the dampening solution composition of the present invention is not particularly different from conventional inks, except that it contains a metal salt of a fatty acid. That is, a desired color tone is obtained by adding resin, mineral oil, solvent, plasticizer, surfactant, cellulose, rubber derivative, etc. as necessary to a drying oil or a modified drying oil as a curing component. It is made by adding organic or inorganic pigments, and further auxiliary agents such as color density adjusting agents and surfactants as necessary.Here, even when using only the above-mentioned vehicle as an overprint varnish, printing ink shall be included in the This is because the method of the present invention can also have a drying accelerating effect on overprint varnishes.

As the lithographic printing ink, one containing a metal salt of a fatty acid is used. Examples include cobalt, manganese, iron, calcium, vanadium, cerium,
Examples include salts of metals such as copper, zinc, lead, and zirconium, and saturated or unsaturated fatty acids such as naphthenic acid, 2-ethylhexanoic acid, oleic acid, linseed oil fatty acid, tung oil fatty acid, and tall oil acid. Any compound may be used as long as it promotes drying of the ink by oxidative polymerization reaction in combination with the above-mentioned polydentate ligand compound. These usage amounts are not particularly different from normal cases.

The dampening solution composition of the present invention can be used in ordinary lithographic printing in combination with the above-mentioned lithographic ink. The amount of dampening water used for 100 parts of lithographic ink is 50 to 200
This is not particularly different from normal.

As mentioned above, by using the dampening solution composition containing the polydentate ligand compound of the present invention, inconveniences such as set-off and blocking due to delayed drying due to oxidative polymerization of ink, which are problems in lithographic printing, can be easily avoided. can be prevented.

The present invention will be specifically explained below using Examples.

Example 1 An oxidative polymerization type ink vehicle was prepared using the following formulation.

(1) Rosin-modified phenolic resin (Tamanol 340 manufactured by Arakawa Chemical) 38% (2) Linseed oil 19 (3) Tung oil 10 (4) 540 solvent (manufactured by Nippon Oil Corporation) ^* 33 100 * 80% paraffinic hydrocarbon 540 〓Petroleum distillate vehicle is mixed with ingredients (1) to (3) and heated to 240℃.
The mixture was kept for 30 minutes, then component (4) was added, the heating source was turned off, and the mixture was left to cool.

To the thus obtained vehicle, 1.5 parts of aluminum octylate was added to 100 parts of the vehicle, and after uniformly mixing, the temperature was raised to 140°C and kept for 15 minutes to effect gelation. Using the gel varnish thus prepared, sheet-fed printing ink was prepared with the following formulation.

Gel varnish 80.0% Carmine 6B#1 (manufactured by Dainichiseika) 18.0 Polyethylene wax 1.85 Manganese 2-ethylhexanoate 0.10 Cobalt 2-ethylhexanoate 0.05 100.00 Separately, use a dampening solution (liquid A) with the following composition. Created.

Tap water 79.0% Etsuchi stock solution NF500 (manufactured by Morohoshi Ink) 1.0 Isopropyl alcohol 20.0 100.0 Furthermore, a polydentate ligand compound solution was prepared using the following formulation.

Bipyridine 10.0% Ethanol 90.0 100.0 A printing dampening solution (Liquid B) was prepared by adding 5% of a polydentate ligand compound solution to the above-mentioned dampening solution (Liquid A). Using these A liquid and B liquid as dampening water, the above-mentioned sheet-fed printing ink was applied to Heidel.
Each sample was printed on 43.5 kg/4.6 size top coated paper (manufactured by Kanzaki Paper Industries) using a KORD offset printing machine, and the drying time was measured using a Choyokai drying tester (manufactured by Toyo Seiki Seisakusho).

As a result, the printing time was 2 hours when using liquid A, while it was 45 minutes when using liquid B, and the transferability was also good.

Example 2 A multidentate ligand compound solution was prepared using the following formulation.

2,2',2''-terpyridine 10.00% isopropyl alcohol 90.00 100.00 Add 5% of the above polydentate ligand compound solution to Solution A described in Example 1 to create a dampening solution for printing (Liquid B). Using this, a printing test was carried out in the same manner as in Example 1, and the drying time was measured.As a result, the drying time was 55 minutes, and the ink transferability was also good.

Example 3 A multidentate ligand compound solution was prepared using the following formulation.

Salicylaldoxime 20.00% Isopropyl alcohol 50.00 n-butyl cellosolve 30.00 100.00 The above polydentate ligand compound solution was added to Solution A of Example 1 at a ratio of 3% to prepare a dampening solution for printing. Using this, printing was performed in the same manner as in Example 1, and the drying time was measured. As a result, the drying time was 50 minutes, the transferability during printing was good, and there were no problems.

Claims (1)

[Claims] 1 characterized by containing a polydentate ligand compound,
A dampening solution composition for lithographic printing using an oxidative polymerization type ink containing a metal salt of a fatty acid.