JPH0680919A - Method for producing varnish for printing ink - Google Patents

Abstract

PURPOSE:To produce the title varnish which can give a printing ink with which lithographic printing can be performed quickly and stably without adversely affecting the other properties. CONSTITUTION:A process for producing a varnish for a printing ink by dissolving a hydroxylated resin, a drying oil and a petroleum-derived solvent by heating under agitation, which process comprises adding a compound selected from among aromatic and am alicyclic carboxylic acids each of which has a plurality of carboxyl groups and anhydrides thereof to the above obtained mixture to produce a varnish of an acid value of 5-100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention promotes water emulsification of ink on a printing press during lithographic printing, and prevents stable roller-peeling by forming a stable water-in-oil type emulsion to prevent printing density. The present invention relates to a method for producing a stable and high-performance printing ink varnish.

[0002]

2. Description of the Related Art A varnish for a printing ink used for a lithographic printing ink is generally composed of a rosin-modified phenolic resin, a petroleum resin or the like dissolved in a drying oil such as linseed oil or a petroleum solvent. Heretofore, these have provided good paper quality and printing workability. However, in recent years, printing machines have tended to be faster. This leads to an increase in broke until stable print density and promotion of printing problems related to water emulsification such as roller peeling, water loss, and stains. Therefore, in order to stabilize printing early by rapid initial emulsification and prevent roller peeling, a surfactant, a fatty acid, or an alkyd resin (hereinafter collectively referred to as a surface-active substance) is added,
Although a method of accelerating the emulsification has been adopted, it has a drawback that it tends to cause water rod entanglement and floating stains due to phase inversion due to deterioration of ink transfer property due to overemulsification.

[0003]

DISCLOSURE OF THE INVENTION As a result of intensive investigations by the present inventors on a method for producing a varnish for printing inks in order to solve the above problems, a viscous printing ink having a carboxyl group as a hydrophilic group has been introduced. When a specific carboxylic acid is used in the production of a varnish for varnish, the varnish is provided with an emulsifying ability capable of forming a stable water-in-oil emulsion at an early stage, and at the same time, the viscosity can be maintained or increased by the cross-linking of the resin. The inventors have found that the emulsifying ability is not excessive and that a novel high-performance printing ink varnish having sufficient practicality as a printing ink varnish can be obtained.

[0004]

The present invention relates to a method for producing a varnish for printing ink by heating and mixing and dissolving a resin having a hydroxyl group, a drying oil and a petroleum solvent, wherein an aromatic carboxylic acid having a plurality of carboxyl groups is used. It relates to a method for producing a varnish for printing ink, which comprises adding a compound selected from the group of acids, alicyclic carboxylic acids and their anhydrides so that the acid value of the varnish is 5 to 100.

At the present time when the mechanism for improving both performances at the same time is not always clear, if we infer reasonably,
A compound selected from the group of aromatic carboxylic acids having multiple carboxyl groups, alicyclic carboxylic acids and their anhydrides (hereinafter collectively referred to simply as carboxylic acids) was added during the preparation of varnishes for printing inks. When a resin having a hydroxyl group and a drying oil and a petroleum solvent are mixed and dissolved, an esterification reaction occurs between the resin having a hydroxyl group and carboxylic acids, and some carboxylic acids crosslink between the resins. It is presumed that most of the carboxylic acids are esterified with the resin at some of the carboxyl groups, and the remaining carboxyl groups impart hydrophilicity to the resin. At this time, some carboxylic acids are dispersed in the varnish in a free state, but in order to achieve the object of the present invention, as many carboxylic acids as possible are bound to the resin, and It is desirable that the remaining. That is,
The introduction of a hydrophilic group according to the present invention does not add a low molecular weight substance such as other surface-active substances, but rather imparts high viscoelasticity by polymerizing at the same time as imparting hydrophilicity, and thus physical It is presumed that overemulsification can be prevented by the inhibition of the formation of water-emulsified particles, despite the increase in the emulsification rate.

In order to bond the carboxylic acid and the resin having a hydroxyl group during the preparation of the varnish of the present invention, the carboxylic acid is required to melt at a temperature suitable for preparing the varnish and not decompose. In addition, it is desirable to have three or more carboxyl groups so that the carboxyl groups remain even if the reaction proceeds to some extent, and the temperature suitable for varnish preparation is often too low for esterification. It is desirable to use an acid anhydride to utilize the esterification reaction by ring opening addition. Examples of such carboxylic acids include trimellitic acid, trimellitic anhydride, pyromellitic anhydride, chlorendic anhydride, 4,4′-biphenyldicarboxylic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, phthalic anhydride, isophthalic acid, and terephthalic acid. ,
4-nitrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride,
Maleated methyl cyclohexene tetrabasic anhydride, 3,
Examples thereof include 3 ′, 4,4′-benzophenone tetracarboxylic acid dianhydride and benzyl succinic anhydride, and these can be used alone or in combination.

Examples of the resin having a hydroxyl group include alkyd resin, urethanized alkyd resin, polyester resin, phenol formaldehyde resin, rosin-modified phenol resin, petroleum resin, butadiene copolymer resin and bisphenol epichlorohydrin type epoxy resin. These can be used alone or in combination of two or more.

The rosin-modified phenolic resin having a hydroxyl group is produced by gum rosin, wood rosin, Indonesia rosin, tall oil rosin, polymerized rosin, and rosins such as modified products thereof; phenols such as phenol and alkylphenol; formaldehyde, paraformaldehyde, Aldehydes such as butylformcel; polyhydric alcohols such as ethylene glycol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol; and, if necessary, carboxylic acid-modified or unmodified petroleum resin, drying oil or its fatty acid, polymerization Drying oil,
It may be carried out according to a known production method (for example, disclosed in JP-B-53-38113, JP-B-61-27425, etc.) in which known raw materials such as polymerized fatty acid and maleated cyclopentadiene polymer are combined, and a special method is used. There is no limit.

Next, a varnish for a printing ink is prepared by mixing and dissolving a resin containing a hydroxyl group and a carboxylic acid with a drying oil and a petroleum solvent and reacting them.
The varnish may be prepared at a temperature of 140 ° C to 280 ° C for an appropriate period of time, but if the preparation temperature is less than 140 ° C, the resin will not be easily dissolved in the drying oil and petroleum solvent, resulting in inefficiency. On the other hand, when it exceeds 280 ° C, it becomes difficult to control the dissolved state of the resin in the drying oil and the petroleum solvent, which is not preferable.

The ratio of the resin having a hydroxyl group to the drying oil and the petroleum solvent is arbitrary, but each raw material is used so that the varnish for the printing ink finally obtained has an acid value of 5 to 100. And usually has a hydroxyl group-containing resin 100
20 to 200 parts by weight of the drying oil and 200 to 20 parts by weight of the petroleum-based solvent are used with respect to parts by weight, and the carboxylic acid is approximately 0.1 to 5 with respect to the total weight of the resin having a hydroxyl group, the drying oil and the petroleum-based solvent. It may be added by weight%.

Examples of the drying oil that can be used in the present invention include flaxseed oil, fish oil, tung oil, synthetic drying oil, dehydrated castor oil and the like. These can be used alone or in combination of two or more kinds. it can.

The petroleum solvent which can be used in the present invention is a hydrocarbon solvent mainly composed of an aliphatic hydrocarbon having a boiling point of 240 to 330 ° C., for example, No. 4 solvent (manufactured by Nippon Oil Co., Ltd.), No. 6 solvent. Solvent (same), No. 7 solvent (same), MC Oil X-06 (Idemitsu Kosan Co., Ltd.), Ink Solvent 300 (Mitsubishi Oil Co., Ltd.) can be mentioned, and these can be used alone or in combination of two or more. Can be used in combination.

The acid value of the varnish for printing ink thus obtained is adjusted to 5 to 100. When the acid value is less than 5, there is no effect of promoting water emulsification, and when the acid value exceeds 100, a large amount of unreacted carboxylic acids may remain.
Not preferable.

A known pigment, a wax compound, a gelling agent, various auxiliaries such as an ink dryer are mixed with this varnish for printing ink, and the mixture is kneaded with a kneader, a three-roll mill, a dispersion stirrer or the like to give a printing ink. obtain. The printing ink varnish of the present invention may be used in combination with a conventionally known printing ink varnish to prepare a printing ink, and the printing ink varnish contains 5 to 50% by weight, more preferably 10 to 20% by weight. It is preferred to use wt%.

The varnish for printing inks obtained by the present invention is a high-performance lithographic ink varnish having excellent high-speed printing suitability in which stable emulsion at an early stage, water bar entanglement due to roller peeling prevention and overemulsification, and stains are simultaneously improved. It is also suitable for use in newspaper printing inks, letterpress inks, and intaglio inks for securities.

[0016]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. However, all parts in the examples mean parts by weight. Ink preparation and varnish preparation were carried out according to conventional methods.

40 parts of Beccasite F-181 (a rosin-modified phenolic resin manufactured by Dainippon Ink and Chemicals, Inc.), 20 parts of linseed oil, No. 6 solvent (manufactured by Nippon Oil Co., Ltd.) 35
And 5 parts of trimellitic anhydride were charged to a reaction vessel, and 200
The temperature was raised to 0 ° C., and the mixture was stirred for 1 hour to dissolve, and a varnish A for printing ink having an acid value of 27 was obtained.

Also, 42 parts of Beccasite F-181 (a rosin-modified phenol resin manufactured by Dainippon Ink and Chemicals, Inc.) and 20 parts of linseed oil, No. 6 solvent (manufactured by Nippon Oil Co., Ltd.)
37 parts were charged into a reaction vessel, heated to 200 ° C., stirred for 1 hour to dissolve, and then aluminum chelate EB2
1 part (manufactured by Hope Pharmaceutical Co., Ltd.) was added and stirred at 160 ° C. for 1 hour to obtain a varnish B for printing ink.

Further, 42 parts of Beccasite F-181 (a rosin-modified phenol resin manufactured by Dainippon Ink and Chemicals, Inc.), 20 parts of linseed oil, and 1 part of trimellitic anhydride were charged into a reaction vessel, and the temperature was raised to 240 ° C. to 1 After stirring for an hour, it was diluted with 35 parts of No. 6 solvent (manufactured by Nippon Oil Co., Ltd.) to obtain a varnish C for a printing ink having an acid value of 23.

Further, in the preparation of the varnish C for printing ink, the same procedure was repeated except that 3 parts of dodecenylsuccinic anhydride was used in place of 1 part of trimellitic anhydride, and the acid value was 2
A varnish D for printing ink No. 5 was obtained.

Example 1 50 parts of varnish B, 10 parts of varnish A, 20 parts of Carmine 6B (red pigment manufactured by Dainippon Ink and Chemicals Co., Ltd.), and 20 parts of No. 6 solvent were kneaded by a conventional three-roll mill to form a book. 100 parts of the inventive ink are obtained.

Example 2 60 parts of varnish C, 20 parts of Carmine 6B (a red pigment manufactured by Dainippon Ink and Chemicals, Inc.) and 20 parts of No. 6 solvent were kneaded by a conventional method with a three-roll mill to prepare ink 100 of the present invention. I got a part.

Comparative Example 1 60 parts of varnish B, 20 parts of Carmine 6B (a red pigment manufactured by Dainippon Ink and Chemicals, Inc.) and 20 parts of No. 6 solvent were kneaded by a conventional three-roll mill to obtain 100 parts of ink. It was

Comparative Example 2 99 parts of the ink of Comparative Example 1 and 1 part of oleic acid were mixed and kneaded with a three-roll mill to obtain 100 parts of ink.

Comparative Example 3 Varnish D60 was used instead of C60 part of varnish in Example 2.
The same procedure was repeated except that 100 parts of ink was used to obtain 100 parts of ink.

The initial emulsification speed of the obtained ink and the entanglement on the water bar of the printing machine were examined.

Regarding the initial emulsification rate, the same amount of ink and water was charged into a DUKE type emulsification tester, and the amount of water taken into the ink after 1 minute, 3 minutes, and 5 minutes (ink quantity is 100) was measured. did.

A small printing machine is used for the entanglement on the water rod, and a certain amount of ink is placed on this roller, and the roll is rotated for a certain time without passing the paper, and the ink is entangled on the water rod. Observe if you come. Those with a narrow entanglement width were considered good.

The results are shown in Tables 1 and 2. The water bar entangled numbers in the table are 5 grades, 5 being excellent and 1 being inferior.
Addition of oleic acid is effective in improving the initial emulsification rate of the ink, but it worsens the entanglement of water rods, and in the ink of Comparative Example 3, the improvement of the initial emulsification rate is insufficient, whereas It can be seen that in the ink of the present invention, although the initial emulsification rate is higher than that in the case of adding oleic acid, the water stick entanglement is not deteriorated.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

When the varnish for printing ink according to the present invention is used, early stabilization of printing can be achieved by rapidly emulsifying the dampening water on the printing machine.

Claims (2)

[Claims] 1. A method for producing a varnish for a printing ink by heating and mixing and dissolving a resin having a hydroxyl group, a drying oil and a petroleum solvent, wherein an aromatic carboxylic acid having a plurality of carboxyl groups, an alicyclic carboxylic acid, and A method for producing a varnish for printing ink, which comprises adding a compound selected from the group of these anhydrides so that the acid value of the varnish is 5 to 100. 2. The method for producing a varnish for printing ink according to claim 1, wherein the resin having a hydroxyl group is a rosin-modified phenol resin.