JP2000160048A - Azo lake pigment and offset ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a brilliant carmine 6B pigment with greatly improved printability concerning dampening water in a printing ink, particularly in an offset ink by dispensing with a rosin treatment in the process of the preparation thereof. SOLUTION: This pigment is obtained by coupling a diazo component prepared by diazotizing p-toluidine-m-sulfonic acid by a conventional method with a coupler component of β-hydroxynaphthoic acid prepared by a conventional method and converting the resultant dye to a lake by calcium after the pH adjustment to 10-11, or by converting to a lake simultaneously with the coupling with the diazo component having a metal for forming a lake added previously thereto, and then aging under heat. If required, an aniline derivative different from the diazo component can be added thereto, a coupler having a different kind of structure may be added to the coupler component to attain transparency, or various kinds of treating agents may be added to an extent such that they do not deteriorate the printability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brilliant carmine 6B pigment useful for various uses, particularly for coloring an offset ink.

[0002]

2. Description of the Related Art Brilliant carmine 6B pigment is widely used for coloring printing inks, paints and plastics, and in particular, is used in large quantities as a red pigment for process inks. In order to control the particles and improve the transparency, clarity, dispersibility, etc. of this pigment, natural rosin such as gum, wood, tall oil, or hydrogenation, disproportionation, maleation, polymerization, etc. A large amount of modified rosin (usually,
(5 to 30% by weight of the pigment).

However, these rosin treatments cause disadvantages such as plate stains on a printing press due to the use of dampening water in offset printing, and decrease the fluidity and stability of ink over time in gravure printing. And other drawbacks. In order to improve such disadvantages, a method of treating the pigment surface with a surfactant or the like, a method of co-lake with a different alkaline earth metal, a method of partially substituting a diazo component or a coupler component with a different component, or There have been proposed methods of adding various resins and surfactants to inks (for example, JP-A-62-20196, JP-A-63-12076).
4, JP-A-2-202557 and JP-A-2-202557.
298559, JP-A-3-163169,
JP-A-3-197574, JP-A-3-29657
No. 1).

[0004]

However, none of these methods has sufficiently solved the above-mentioned drawbacks, and the brilliant carmine 6 having the above-mentioned drawbacks solved.
There is a need for B pigments. It is an object of the present invention to provide a brilliant carmine 6B pigment having significantly improved printability with respect to fountain solution in printing inks, especially offset inks. The present inventors have conducted intensive studies to achieve this object, and as a result, have found that the object is achieved by using a brilliant carmine 6B pigment that has not been subjected to rosin treatment in the production process. Reached.

[0005]

The above object is achieved by the present invention described below. That is, the present invention relates to a brilliant carmine 6B pigment which is not subjected to a rosin treatment in its manufacturing process, and an offset ink using the pigment as a coloring agent.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Brilliant carmine 6 of the present invention
The B pigment is characterized in that it has not been subjected to a rosin treatment in the production process, and the pigment can be produced by a conventionally known method, and the production method itself is not particularly limited. The brilliant carmine 6B pigment of the present invention comprises
For example, it is manufactured according to the following manufacturing method. That is, the pigment is obtained by coupling a diazo component prepared by diazotizing p-toluidine-m-sulfonic acid by a conventional method with a coupler component of β-hydroxynaphthoic acid prepared by a conventional method, and obtaining a dye. And, if necessary, after pH adjustment,
It can be obtained by lacking with calcium or by adding a lacking metal to the diazo component in advance, lacking at the same time as coupling, and aging at elevated temperatures. If necessary, a different aniline derivative may be added to the diazo component, or a coupler having a heterogeneous structure may be added to the coupler component to increase the transparency. And the like may be added to such an extent that printability is not reduced.

[0007] The conventional pigment is prepared by adding an alkali salt solution (rosin soap) or emulsion solution such as natural or modified rosin to the pigment during the above production process, for example, in a diazo or coupler component, or in a dye or pigment slurry. It is manufactured by a method in which rosin treatment is performed in which this is deposited on the surface of the pigment with calcium or another dissimilar metal or acid. However, in the pigment of the present invention, these rosin treatments are not performed, and therefore, in a printing ink using the pigment of the present invention as a coloring agent, particularly in an offset ink, the greatest disadvantage at the time of printing is obtained. This has made it possible to dramatically improve the printability of a dampening solution.

[0008]

The present invention will be described more specifically with reference to the following examples and comparative examples. In the following description, parts and% are based on weight unless otherwise specified.

Example 1 18.7 parts of p-toluidine-m-sulfonic acid were diazotized by a conventional method to give a diazo solution, and 17.9 parts of β-hydroxynaphthoic acid and 2-hydroxy-naphthalene-3-carboyl-anilide were used. 1.32 parts (5 mol% of under-pickling) is adjusted by a conventional method to prepare a under-pickling liquid. The diazo solution is dropped (coupling reaction) into the undercoating solution in 20 minutes to prepare a dye, and then stirred for 1 hour. Next, the pH is adjusted to 10 to 11, and 19 parts of calcium chloride dihydrate is added to form a lake. After stirring for 1 hour, the temperature was raised to 80 ° C., 2.1 parts of stearylamine (5% based on the pigment) was dissolved in acetic acid, and the mixture was filtered and washed with water to obtain a press cake, and 44.5 parts of a pigment was obtained. A part thereof was dried and pulverized to obtain a powder to obtain a brilliant carmine 6B pigment of the present invention.

Example 2 18.7 parts of p-toluidine-m-sulfonic acid were diazotized by a conventional method, and 19 parts of calcium chloride dihydrate was added to form a diazo solution. 17.9 parts of β-hydroxynaphthoic acid and 2 parts of 2
1.32 parts of -hydroxy-naphthalene-3-carboyl-anilide is prepared by a conventional method to prepare a dipstick. The diazo solution is dropped (coupling reaction) in 20 minutes into this undercoating solution to prepare a pigment, and then stirred for 1 hour. Then 80
C., 2.1 parts of stearylamine was dissolved in acetic acid, and the mixture was filtered and washed with water to form a press cake, and a part of the cake was dried and pulverized to a powder to obtain a brilliant carmine 6B pigment of the present invention. Was.

Comparative Example 1 In Example 1, the pH was adjusted after coupling, and brilliant carmine obtained by adding rosin soap (2.2 parts of gum rosin—an aqueous solution in which 5% of pigment was dissolved in sodium hydroxide) was added. 6B pigment.

Comparative Example 2 Brilliant carmine 6B pigment obtained in Example 1 by adding rosin soap (4.7 parts of gum rosin-an aqueous solution in which 10% of the pigment is dissolved in sodium hydroxide) after adjusting the pH.

Comparative Example 3 A brilliant carmine 6B pigment obtained in Example 1 by adjusting the pH and then adding rosin soap (10.6 parts of gum rosin-20% based on the pigment in an aqueous solution of sodium pigment).

The pigment presscakes and powdered pigments of the above Examples and Comparative Examples were used as lithographic inks according to the following ink production method, and various tests were conducted. (Preparation of base ink) Preparation of press cake into ink 300 parts of a lithographic ink varnish is put into a test flasher, 100 parts of a pigment press cake is added by pigment weight, and the mixture is kneaded at a temperature of 70 ° C. to remove primary separated water. Further, after removing the secondary separation water at 110 ° C. under reduced pressure, 100 parts of a varnish is added and taken out of the test flasher, and a base ink is prepared through a three-roll mill. 2. Preparation of Ink from Powder Pigment After premixing 100 parts of powder pigment and 400 parts of lithographic ink varnish, a base ink is produced through a three-roll mill. (Ink adjustment) The above inks 1 and 2 were adjusted to a tack value of 10 to 10.5 with a lithographic ink varnish and a solvent (incometer, 32 ° C, 1200 rpm, 20 rpm).
Seconds).

(Offset Printing Suitability Test) Using the adjusted ink, an offset printing machine Offset 211 manufactured by Gesettner Co., Ltd. was used to test the suitability for rising, the width of water, and the reproducibility of halftone dot reproducibility. Table 1 shows the evaluation results obtained by converting the pigment press cake into an ink by the flushing method, and Table 2 shows the evaluation results obtained by converting the powdered pigment into the ink by the three-roll mill method.

Table 1

Table 2

[0018]

According to the present invention described above, there is provided an azo lake pigment in which the printability relating to fountain solution in offset ink is dramatically improved.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshitaka Terada 1-7-6 Nihombashi Bakurocho, Chuo-ku, Tokyo Inside Dainichi Seika Kogyo Co., Ltd. (72) Inventor Hidemi Minamishin 1 Nihonbashi Bakurocho, Chuo-ku, Tokyo No. 7-6 F-term in Dainichi Seika Industry Co., Ltd. (reference) 4J039 BA30 BC40 BC54 BC65 BC73 BC75 BE01 CA07 EA15 EA44 EA48 GA02

Claims (2)

[Claims] 1. A brilliant carmine 6B that has not been subjected to a rosin treatment in its production process.
Pigment. 2. An offset ink comprising the brilliant carmine 6B pigment according to claim 1 as a coloring agent.