JPH0715075B2 - Ink modifier - Google Patents

Description

TECHNICAL FIELD The present invention relates to a modifier for a printing ink,
More specifically, it relates to a modifier for obtaining an ink suitable for waterless planographic printing.

[Prior Art] A waterless lithographic printing method using a lithographic printing method that does not require such a dampening solution has been proposed, as opposed to the lithographic printing method that utilizes the ink repulsion property of the dampening solution, which is currently the mainstream of printing. ,
In particular, a method of printing using a lithographic printing plate provided with silicone rubber in a non-image area has been put into practical use.

In such waterless lithographic printing, it is known that printing with a conventional oil-based ink is not preferable because it causes scumming.

The phenomenon that scumming occurs in waterless lithographic printing is due to the friction of the drive unit and rollers of the printing machine during printing, the plate surface temperature rises, the cohesive force of the ink itself decreases, and it is originally ink repellent. Ink adheres to the non-image areas that should be printed.

In order to improve this, a method of using a large amount of a binder resin component to increase the cohesive force and improve the stain resistance is conceivable, but this method causes troubles such as piling on a blanket and waste of paper.

As another improvement method, there is a method using an organic clay as disclosed in JP-A-57-12077. However, this method causes problems such as a decrease in gloss and deterioration of printability when an attempt is made to improve the resistance to scumming. Further, JP-A-59-147072 and JP-B-50-11287 propose a method of adding an organosiloxane.
However, the former is used by adding it to what has already been a printing ink, and the latter is added at the stage of ink production, but both are used for the purpose of giving a strong cohesive force to the ink. Is. However, if this method is used to achieve high resistance to background stains, there is a problem in that the transferability of the ink becomes extremely poor. In addition, the organosiloxane added by the ink transfer at the time of additional printing or film laminating is added. Bleed out causes problems such as being impossible.

Polyamide molecules are used in Orotake 5040 (Dainichi Seika Co., Ltd.) as a commercially available ink additive.
Orotake 5040 has the effect of increasing the resistance to fountain solution and making it difficult for the ink to be emulsified, as an effect for plate-type ink that uses fountain solution. Therefore, features such as prevention of background stains and floating stains due to emulsification are shown.

Further, as the effect of the polyamide molecules in Orotakes 5040, it is shown that they are polymerized with moisture or dampening water molecules in the air to accelerate the setting and drying of ink and prevent the backing.

However, when this Orotics 5040 was added to a waterless lithographic ink and printed, improvement effects such as ink transferability and on-machine stability were recognized, but there was no effect on the improvement of stain resistance and addition There is a problem that the stain resistance is lower than that of the previous ink.

[Problems to be Solved by the Invention] An object of the present invention is to eliminate the above-mentioned drawbacks of conventional inks,
An object of the present invention is to provide an ink composition having excellent resistance to background smear and excellent printability.

[Means for Solving Problems] The object of the present invention is achieved by an ink modifier, which is mainly composed of an amine compound containing active hydrogen in the molecule and a cobalt compound.

Examples of the amine compound containing active hydrogen used in the present invention include ethylamine, n-propylamine, and n.
-Butylamine, hexylamine, laurylamine, stearylamine, ethanolamine, monoamines such as allylamine, ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, diamines such as hexamethylenediamine, diethylenetriamine, triethylenetetramine, bishydroxydiethylenetriamine Polyamine, amine adduct, etc. can be effectively used.

As the amide compound as an amine derivative, formic acid, acetic acid, propionic acid, itaconic acid, caprylic acid, glycolic acid, acrylic acid, lauric acid, myristic acid,
Palmitic acid, stearic acid, oleic acid, linoleic acid, monocarboxylic acids such as linoleic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, Organic dicarboxylic acids such as dimer acid, organic tricarboxylic acids such as trimellitic acid, organic carboxylic acids such as 3,9-bis (2carboxyalkyl) 2,4,8,10-tetraoxaspiroundecane and the above amines and diamines , And polyamines and the like.

The amine compound containing active hydrogen used in the present invention has the above-described structural composition, but in view of handling safety and the like, a polyamide resin is preferable, and a polyamide resin having 6 carbon atoms is preferable from the viewpoint of compatibility with the resin and the solvent. A polyamide resin composed of -60 acid and polyamine is particularly preferably used.

The molecular weight of the polyamide resin is preferably in the range of 500 to 20,000, more preferably 500 to 10,000.

Examples of the cobalt compound used in the present invention include a cobalt salt of an inorganic acid or an organic acid, and a cobalt salt with an organic acid is preferable from the viewpoint of good compatibility with inks and organic solvents.

Organic acids referred to herein include, for aliphatic carboxylic acids, formic acid, acetic acid, propionic acid, caproic acid, fluorosuccin, lactic acid, thioglycolic acid, acrylic acid, lauric acid, stearic acid, adipic acid, pimelic acid, sebacic acid. , Maleic acid, fumaric acid, naphthenic acid, camphoric acid, leuconic acid,
Examples of the aromatic carboxylic acid include benzoic acid, phenylacetic acid, cinnamic acid, phenylpropiolic acid, phthalic acid, vanillic acid, veratrumic acid, piperonic acid, orseric acid and piperic acid. Can be mentioned. In addition to these acids and cobalt salts, chelate compounds such as alkyl acetonato cobalt can also be used.

Among these cobalt compounds, cobalt naphthenate is preferable because it has a large effect of improving the resistance to background stains, has a good affinity with ink, and is easily available.

The composition of the preferred modifier is preferably 0.1 to 80% by weight, and more preferably 5 to 50% by weight, of the cobalt compound with respect to the amine compound containing active hydrogen in the molecule. When the content of the cobalt compound is less than 0.1% by weight, the effect of improving the stain resistance is reduced. On the contrary, even if the content of the cobalt compound exceeds 80% by weight, the effect of improving the stain resistance becomes small.

In the present invention, the amine compounds may be used alone or in combination of two or more.

Further, the ink modifier may be used by adding a solvent, resin or the like which is not reactive with the amine compound having active hydrogen or the cobalt compound.

To prepare the ink modifier, the amine compound may be added to the amine compound containing active hydrogen in the molecule and mixed by stirring. At this time, you may dilute with the said solvent, resin, etc.

When the ink is modified using the ink modifier thus adjusted, the amount of the modifier added is not particularly limited and is appropriately selected depending on the type of ink to be modified and printing conditions, but is preferably It is preferable to select it in the range of 0.1 to 10% by weight. The ink modifier of the present invention can generally improve the stain resistance of the ink by increasing the addition amount, but if added excessively, the ink will gel, so care must be taken. . Or, since these reactions proceed in a very short time, it is effective to appropriately add them when it is necessary to improve the stain resistance of the ink on site. Of course, the ink modifier of the present invention can be added when adjusting the varnish of the ink.

The constituents of the vehicle for ink in which the modified ink of the present invention is effectively used are known ones, for example, drying oil, rosin, rosin ester, phenol resin, rosin-modified phenol resin, alkyd resin, epoxy resin,
Epoxy acrylate, acrylic acid ester of polyhydric alcohol, urethane acrylate, polyester acrylate, polyether acrylate, acrylate alkyd, and melamine acrylate nad can be used, and rosin-modified phenol resin and epoxy resin are particularly preferable.

Further, as the colorant, those used in conventional ink compositions such as inorganic or organic pigments can be used.

Further, as other additives, for example, wax, grease, desiccant, dispersant, filler, and other known additives can be used.

The ink modifier of the present invention is used for obtaining an ink particularly suitable for waterless lithographic printing, but of course, other known inks such as UV curable ink, electron beam curable ink and fountain solution are used. It can also be used effectively as printing ink.

In addition to the printing ink, the ink modifier of the present invention can be used as a regulator for increasing molecular chain elongation and viscosity of resins and the like.

[Examples] Hereinafter, the present invention will be specifically described with reference to Examples.

Example 1 Condensation product of timer acid and diethylenetriamine (molar ratio
20% by weight of cobalt naphthenate was added to a 1: 1) polyamide compound (molecular weight 5000), and the mixture was stirred and mixed with a modifier 1
2% by weight of this in a commercially available UV-curable ink (Daini Nippon Ink Co., Ltd., "Diacure" New OL Ben)
And 6% by weight of a high boiling point petroleum solvent (“DIALENE” 168 manufactured by Mitsubishi Petroleum Co., Ltd.) as a tack-cutting agent are mixed to form an ink A.

Comparative Example 1 Condensation product of timer acid and diethylenetriamine (molar ratio
Ink B is the ink obtained in the same manner as in Example 1 except that the 1: 1) polyamide condensate (molecular weight 5000) is used instead of the modifier 1.

Comparative Example 2 Condensation product of timer acid and diethylenetriamine (molar ratio
Example 1 was repeated except that 20% by weight of manganese naphthenate was added to the polyamide condensate (molecular weight 5000) of 1: 1) and the mixture was stirred and mixed as a modifier 3, which was used instead of the deformer 1.
The ink obtained in exactly the same manner as above is designated as ink C.

Example 2 In a separable flask equipped with a stirrer, epoxy acrylate (“Lipoxy” SP-5003, manufactured by Showa High Polymer Co., Ltd.,
Viscosity 500 poise) 90% by weight, mono-t-butylhydroquinone (Katayama Chemical Co., Ltd.) 0.2% by weight, No. 5 solvent (Nippon Oil Co., Ltd. hydrocarbon solvent, boiling point 270-310)
8% by weight) and 1.8% by weight of modifier 1 were added, and well stirred in an oil bath at 60 ° C for 30 minutes. 50% by weight of the thus modified prepolymer, 18% by weight of cyanine blue, 5% by weight of calcium carbonate, 5% by weight of benzophenone, 20.98% of trimethylolpropane triacrylate
% By weight, 0.02% by weight of mono-t-butylhytroquinone,
Ink D is an ink obtained by kneading 1% by weight of polyethylene wax with a triple roll.

With respect to the inks A to D thus obtained, the tack, flow and background stain resistance index were measured, and the results in Table 1 were obtained.

Here, the tack is made by Toyo Seiki Co., Ltd.)
Also, the flow is a flow tester (manufactured by Kumagai Riki Co., Ltd.)
Further, the background stain generation index is measured by providing a plate heating element on the plate copper, attaching a waterless planographic printing plate thereon, and printing the plate surface while raising the temperature without supplying dampening water. Then, the plate surface temperature when the background smear occurred in the non-image area of the printed matter at a constant solid density was taken as the background smear occurrence index. The ink having a higher background stain generation index is less likely to cause background stain in practical printing.

From these results, the inks A and D have appropriately large values for the background stain resistance index, and other tacks and flows are printable values.
When printed with a Hamada Star Offset machine, preferable printing of 35,000 or more copies was achieved. On the other hand, the inks B and C had a low scumming index of 23 or less, and scumming was generated, so that a preferable printed material could not be obtained.

[Advantages of the Invention] Since the present invention is configured as described above, it is possible to remarkably improve the background stain resistance by appropriately adding it to the ink, and to easily use the ordinary PS ink for waterless planographic printing. It can be replaced with ink and has remarkable practical effects.

Claims (1)

[Claims] 1. An ink modifier, which is mainly composed of an amine compound containing active hydrogen in the molecule and a cobalt compound.