JP3292046B2 - Method for producing pigment composition, pigment composition and use thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for pulverizing a soluble azo or insoluble azo pigment, and a resin treatment method.

[0002]

2. Description of the Related Art Generally, when a pigment is used as a coloring material, its primary particles must be made fine in order to impart appropriate properties such as coloring power and sharpness. Higher pigments typically represented by quinacridone, phthalocyanine, etc.
While two processes, a pigment synthesis process and a micronization process, are performed, soluble and insoluble azo pigments take measures to make the pigment particles fine when synthesizing them. Not done.

On the other hand, as a method of developing a pigment for various uses, there are a method using a dry pigment and a method using a wet cake pigment containing water. In the case of a dry pigment, primary particles of the pigment grow due to heat during drying, and it is difficult to obtain sufficiently fine particles. Therefore, a large amount or an expensive additive must be added to prevent this. Further, since the dried pigment is strongly agglomerated, when it is developed into ink or the like, much time and energy are required for the dispersion step.

A method using a wet cake pigment is represented by a flushing method for producing an offset ink. Since this method is a method of directly inverting aqueous pigment particles into a varnish, it is possible to minimize the particle growth. However, there are problems such as poor handling, a flushing device, and drainage as compared with the dry pigment.
Therefore, a dry pigment or a pigment composition capable of producing a printing ink with the same degree of dispersion as when a wet cake pigment is used is desired.

Heretofore, as a means for improving the dispersibility of a pigment, a resin treatment represented by rosin at the time of synthesis has generally been used. However, processing of these resins in large amounts is known to adversely affect the suitability of printing inks, and the amount of processing is limited.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides an azo-based pigment which is subjected to dry pulverization to make the primary pigment particles finer, and at the same time, a resin for printing ink which is extremely excellent in dispersibility and transparency. An object of the present invention is to provide a soluble or insoluble azo pigment composition having coloring power.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a method for producing a pigment composition for a printing ink, comprising synthesizing a soluble azo pigment or an insoluble azo pigment, drying and then dry-grinding the azo pigment together with a rosin-modified phenol resin. . Furthermore, the present invention relates to the above-mentioned production method in which dry pulverization is performed in a deoxygenated atmosphere.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail. The soluble azo pigment in the present invention is a lake pigment obtained by laking an azo dye obtained by coupling a diazonium salt of an aromatic amine having a soluble group with a coupler component with a metal salt for lake.

As the aromatic amine having a soluble group,
1-amino-4-methylbenzene-2-sulfonic acid, 1
Amino 4-methyl 5-chlorobenzene 2-sulfonic acid, amino 4-chloro-5-methylbenzene
Examples of coupler components such as 2-sulfonic acid include β-oxynaphthoic acid and β-naphthol, and metal salts for lakes include calcium, barium, and manganese.

The insoluble azo pigment in the present invention is a pigment obtained by coupling a tetrazo solution of benzidine with a coupler solution containing acetoacetanilide.

As a tetrazo solution of benzidines,
3,3'-dichlorobenzidine, 2,2 ', 5,5'-
Examples of a coupler solution such as tetrachlorobenzidine include acetoacetanilide, acetoaceto─o-toluidide, acetoaceto─m-xylide, and acetoaceto─o.
-Anisidide, acetoaceto {2,5-dimethoxyanilide, acetoaceto {p-anisidide, acetoaceto}
2,5-dimethoxy {4} -chloroanilide, acetoaceto-o-chloroanilide and the like.

As means for making the soluble or insoluble azo pigment finer, a base or coupler having a different structure may be used in addition to the base or coupler which is the main component of the pigment, or an activator, resin, especially rosin may be used. It is generally added.

[0013] The present invention is a method in which a soluble azo pigment or an insoluble azo pigment is dry-pulverized together with a resin to make pigment particles fine and to strongly treat the resin. Therefore, the soluble azo pigment and the insoluble azo pigment used in the present invention may have large pigment primary particles. In other words, it is not necessary to use another diazo component or coupling component together or to perform rosin treatment or the like in order to form fine particles at the time of synthesis, but these treatments may be performed if desired.

In the dry pulverization of the present invention, a pigment is pulverized using a pulverizer containing a pulverization medium such as beads without substantially interposing a liquid substance. The pulverization is performed using a pulverizing force or a destructive force caused by collision between the pulverizing media. As the dry pulverizer, a known method such as a dry attritor, a ball mill, and a vibration mill can be used.

As the resin added in the present invention, a resin suitable for the final use, that is, a resin for printing ink is used as it is.

[0016]

On the other hand, the rosin-modified phenol resin may be degraded by oxidation depending on its type and conditions. Oxidation of the resin changes its solubility, color tone, and other physical properties, making it impossible to bring out the performance of the designed ink. Therefore, in order to prevent this, it is necessary to perform dry pulverization in a state where oxygen is cut off.

An effective means for preventing this is a method in which the inside is filled with an inert gas, the most common one being a method of flowing nitrogen. Such a method of blocking oxygen is also effective from the viewpoint of safety.

It tends to be considered that a larger amount of the resin is more advantageous. However, a larger amount of the resin increases the risk of adhesion and sticking of the resin inside the dry pulverizer. Since this is naturally affected by the softening point of the resin and the pulverization temperature, it is necessary to determine the optimum processing amount in consideration of these conditions.

When a printing ink is produced using the pigment composition of the present invention, the printing ink solvent or the solvent in the varnish may be a printing ink such as a high-boiling petroleum solvent, an aliphatic hydrocarbon solvent, or a higher alcohol solvent. Any solvent that does not contain aromatics can be used alone or in combination of two or more as long as it is a suitable solvent.

Similarly, as a resin for a printing ink varnish when producing a printing ink, a resin suitable for a printing ink such as a rosin-modified phenol resin, a rosin-modified maleic resin, a petroleum resin, an alkyd resin; A drying oil or polymerization drying oil suitable for a printing ink such as linseed oil can be used singly or in combination of two or more kinds together with other additives for a printing ink.

The dispersion of the pigment composition of the present invention in the ink varnish sufficiently proceeds with gentle stirring, and then the preparation of the base ink is completed by passing through a simple dispersing machine. It has been confirmed that the pigment composition obtained by the method of the present invention not only has a markedly improved coloring power, transparency and the like than before the treatment, and shows extremely excellent dispersibility. .

[0023]

The present invention will be specifically described below with reference to examples and comparative examples.

Example 1 A soluble azo pigment (CI Pig) obtained by coupling a diazonium salt of 1-amino-4-methylbenzene-2-sulfonic acid and β-oxynaphthoic acid and raked with calcium metal. .Red 57: 1)
And rosin-modified phenol resin having a softening point of 160 ° C. were added to a dry attritor, and pulverized at 60 ° C. for 1 hour under a nitrogen stream. Next, 28 parts by weight of the obtained milled material was added to 33 parts by weight of a varnish for printing ink and 15 parts by weight of AF Solvent 7 (manufactured by Nippon Oil Co., Ltd.), and the mixture was gently stirred at 50 ° C. for 1 hour. , 60
When the mixture was ground once with three rolls at a temperature of 7.degree.
It was dispersed to 5μ or less. Next, 22 parts by weight of a varnish and 12 parts by weight of AF Solvent 7 were added to the obtained base ink to prepare a final ink. When the ink of this example was compared with the ink produced by the flushing method from the water paste of the soluble azo pigment used in this example, the ink of this example was much more transparent, tinted, and glossy. It was excellent.

[0024]

Comparative Example 1 The same soluble azo pigment as in Example 1 (CIP
ig. Red 57: 1) was added to a dry attritor in an amount of 70 parts by weight, and pulverized at 60 ° C. for 1 hour in a nitrogen stream. Next, 16 parts by weight of the obtained milled material was added to 57 parts by weight of a varnish for printing ink and 3 parts by weight of AF Solvent No. 7, and the mixture was gently stirred at 50 ° C. for 1 hour.
The mixture was kneaded three times with this roll, but the pigment particles were 15.0 μm and the dispersion was poor. Next, 22 parts by weight of varnish and 12 parts by weight of AF Solvent 7 were added to the obtained base ink to prepare a final ink. Although the ink of this comparative example had improved transparency compared to the ink produced with the pigment before dry milling,
The coloring power, gloss, etc. were poor. Further, as compared with the ink of Example 1, it was clearly inferior in terms of transparency, coloring power, gloss and the like.

[0025]

Example 2 Of the diazonium salt components of Example 1, 1%
3 for amino {4-methylbenzene} 2-sulfonic acid
70% by weight of a soluble azo pigment obtained by coupling a diazonium salt to which 1% by weight of 1-amino-4-methylbenzene-3-sulfonic acid is added with β-oxynaphthoic acid and laked with calcium metal. 56 parts by weight of a rosin-modified phenol resin having a softening point of 160 ° C. was added to a dry attritor, and pulverized at 90 ° C. for 1 hour under a nitrogen stream. Next, 28 parts by weight of the obtained milled material were added to 33 parts by weight of a varnish for printing ink and 15 parts by weight of AF Solvent No. 7, followed by gentle stirring at 50 ° C. for 1 hour.
When the mixture was kneaded once with this roll, the pigment particles were dispersed to 7.5 μm or less. Next, 22 parts by weight of varnish and 12 parts by weight of AF Solvent 7 were added to the obtained base ink to prepare a final ink. When the ink of this example was compared with the ink prepared by the flushing method from the water paste of the soluble azo pigment used in this example, the ink of this example was much more transparent, tinting, and glossy. It was excellent.

[0026]

EXAMPLE 3 A rosin soap having a resin solid content of 10% based on the dye was added to the dye obtained by coupling the diazonium salt and β-oxynaphthoic acid of Example 1, followed by lake formation with calcium metal. 7 of the soluble azo pigment
0 parts by weight and 35 parts by weight of a rosin-modified phenol resin having a softening point of 160 ° C. were added to a dry attritor, and pulverized at 90 ° C. for 1 hour under a nitrogen stream. Next, 24 parts by weight of the obtained crushed material was mixed with 41 parts by weight of a varnish for printing ink, AF
In addition to 11 parts by weight of Solvent No. 7, the mixture was gently stirred at 50 ° C. for 1 hour and then kneaded once with three rolls at 60 ° C., whereby the pigment particles were dispersed to 7.5 μm or less. next,
To the obtained base ink, 22 parts by weight of a varnish and 12 parts by weight of AF Solvent 7 were added to prepare a final ink. When the ink of this example was compared with the ink prepared by the flushing method from the water paste of the soluble azo pigment used in this example, the ink of this example was much more transparent, tinting, and glossy. It was excellent.

[0027]

Example 4 An insoluble disazo pigment (CI Pig. Y) obtained by coupling a 3,3'-dichlorobenzidine tetrazo solution with acetoacetanilide.
70 parts by weight of ello12) and 70 parts by weight of a rosin-modified phenol resin having a softening point of 160 ° C. were added to a dry attritor, and pulverized at 50 ° C. for 1 hour under a nitrogen stream. Next, 14 parts by weight of the obtained milled material was added to 41 parts by weight of a varnish for printing ink and 10 parts by weight of AF Solvent 7, and the mixture was gently stirred at 50 ° C. for 1 hour.
When the mixture was kneaded once with this roll, the pigment particles were dispersed to 7.5 μm or less. Next, varnish 2 is applied to the obtained base ink.
4 parts by weight and 11 parts by weight of AF Solvent 7 were added to prepare a final ink. When the ink of this example was compared with the ink prepared by the flushing method from the water paste of the insoluble azo pigment used in this example, the ink of this example was much more transparent, tinting, and glossy. It was excellent.

[0028]

Comparative Example 2 The same insoluble disazo pigment as in Example 1 (C.I.
I. Pig. 70 parts by weight of Yellow 12) were added to a dry attritor, and pulverized at 50 ° C. for 1 hour under a nitrogen stream. Next, 7 parts by weight of the obtained milled material was added to 55 parts by weight of a varnish for printing ink and 3 parts by weight of AF Solvent No. 7, and the mixture was gently stirred at 50 ° C. for 1 hour.
Was milled three times with three rolls, but the pigment particles were 17.5 μm.
It was only dispersed until. Next, 22 parts by weight of varnish and 11 parts by weight of AF Solvent 7 were added to the obtained base ink to prepare a final ink. The ink of this comparative example was improved in transparency as compared with the ink prepared with the pigment before dry pulverization, but was poor in coloring power, gloss and the like. Further, as compared with the ink of Example 2, it was clearly inferior in terms of transparency, coloring power, gloss and the like.

[0029]

Example 5 The insolubility obtained in Example 4 by coupling a coupling component containing acetoacetanilide and 3.6% by weight of acetoacetom-xylide to a tetrazo solution. 7 disazo pigments
0 parts by weight and 70 parts by weight of a rosin-modified phenol resin having a softening point of 160 ° C. were added to a dry attritor, and pulverized at 90 ° C. for 1 hour under a nitrogen stream. Next, 14 parts by weight of the obtained milled material was mixed with 41 parts by weight of a varnish for printing ink,
The mixture was added to 10 parts by weight of F Solvent No. 7, stirred gently at 50 ° C. for 1 hour, and then kneaded once with three rolls at 60 ° C., whereby the pigment particles were dispersed to 7.5 μm or less. Next, 24 parts by weight of varnish and 11 parts by weight of AF Solvent No. 7 were added to the obtained base ink to prepare a final ink. When the ink of this example was compared with the ink prepared by the flushing method from the water paste of the insoluble azo pigment used in this example, the ink of this example was much more transparent, tinting, and glossy. It was excellent.

[0030]

Example 6 In Example 1, 70% by weight of an insoluble disazo pigment obtained by coupling a tetrazo solution with acetoacetanilide and then adding a rosin soap having a resin solid content of 10% to the dye was added. Part and softening point 16
56 parts by weight of a rosin-modified phenol resin at 0 ° C. was added to a dry attritor, and pulverized at 80 ° C. for 1 hour under a nitrogen stream. Next, 12.6 parts by weight of the obtained ground material was
43.8 parts by weight of varnish for printing ink, AF Solvent 7
No. 8.6 parts by weight, and after gentle stirring at 50 ° C. for 1 hour, the mixture was kneaded once with three rolls at 60 ° C., whereby the pigment particles were dispersed to 7.5 μm or less. Next, 24 parts by weight of varnish was added to the obtained base ink, AF Solvent 7
By weight, the final ink was adjusted. When the ink of this example was compared with the ink prepared by the flushing method from the water paste of the insoluble azo pigment used in this example, the ink of this example was much more transparent, tinting, and glossy. It was excellent.

Industrial Applicability The present invention provides a pigment composition having excellent dispersibility by simultaneously performing resin treatment in the step of dry-grinding soluble and insoluble azo pigments. Usually, the soluble and insoluble azo pigments are generally used to make the primary particles finer during the synthesis, but in the present invention, since the fineness is separately performed, the transparency is improved even if a pigment having a large primary particle is used. It is possible.

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Claims (2)

(57) [Claims] 1. A method for producing a pigment composition for a printing ink, comprising: synthesizing a soluble azo pigment or an insoluble azo pigment, drying and then dry-grinding the azo pigment together with a rosin-modified phenol resin. 2. The dry grinding is performed in a deoxygenated atmosphere.
The manufacturing method as described.