JPS5813660A - Preparation of azo pigment - Google Patents

Abstract

PURPOSE:To obtain a disazo pigment without the deterioration of tinting strength, etc. even on application to rubber, by coupling a tetrazo compound of dicyclobenzidine with an acetanilide compound containing a specific compound as a coupling component. CONSTITUTION:A tetrazo compound of 3,3-dicyclobenzidine is coupled with an acetanilide compound, e.g. acetoaceto-o-toluidide, in which 1-50mol% is substituted by a compound of the formula, (X is carboxyl, sulfonic acid, OH or a metallic salt thereof), e.g. N,N'-bis-(2-carboxyphenyl)malonamide, as a coupling component to give the aimed disazo pigment. To obtain the compound of the formula, one mole malonic acid is reacted with two moles aniline derivative having sulfonic acid, carboxyl groups, etc. The resultant azo pigment is useful for coloring rubber, printing ink, coating materials, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a disazo pigment useful for various uses, particularly for coloring rubber and the like.

Hitherto, diazo pigments obtained from a,3-V chlorobenzidine and various acetoacedoanilide compounds have been widely used for coloring rubber, pigmentation, printing ink, etc. When used for coloring, the coloring power is significantly reduced during vulcanization of rubber, and the color tone becomes unclear.

As a result of intensive research to solve the above-mentioned drawbacks of the prior art, in addition to producing disazo pigments, it is possible to use an acetoacedoeride compound containing a specific compound as a coupling component. The present inventor discovered that the resulting disazo pigment was a pigment that solved the above-mentioned drawbacks, and that the pigment thus obtained was also a highly improved pigment for paints and printing inks. completed.

That is, the present invention provides a method for producing an azo pigment, which comprises coupling a tetrazotized product of 3,3-dichlorobenzidine to an acetoacedoeride compound,
This is a method for producing a disazo pigment, characterized in that about 1 to 50 moles of the acetoacedoanilide compound is substituted with a compound represented by the following general formula (R).

(However, X in the formula is a differential boxyl group, a sulfonic acid group, a hydroxyl group, or a metal salt thereof.) To explain the present invention in detail, the 3,3-dichlorobenzidine and carboxyl group used in the present invention, sulfonic acid group,
Alternatively, acetoacetoanilide compounds that do not have a hydroxyl group are known. Acedoanilide, 4-chloro-2,5-dimethoxyacetoacetohydride, 2,4-dimethoxyacetoacetanilide, 0-acetoacetoacetohydride, 0-acetoacetotoluidide, 2,4- Acetoacetoanilide, P-acetoacetoanidide, P-acetoacetotoluidide, 4-chloro-2-methyl-acetoacetoanilide, P-ethoxyacetoacetanilide, 4-, -)
rho 2-methylacetoacedoanilide, 4-acetoacetaminophthalide, 5-7cetoacetaminobenzimidazolone, 4-benzoylamino-2,5-diethoxy7acetoacetanilide, 4-acetylamino −
Examples include acetoacedoanilide.

The compound represented by the general formula (RI) used in combination with the above-mentioned known acetoacedoanilide compound is a combination of malonic acid or its derivative in a molar proportion and an aniline derivative having a sulfonic acid group, a carboxylic acid group, or a hydroxyl group. These compounds can be easily obtained by a method of reacting with a molar ratio, or by other methods.These compounds can also be used as a mixture.Such compounds having carboxyl, sulfonic acid, or hydroxyl groups are About 0.01 mol to about 1.0 mol per mol of the above-mentioned acetoacedoanilide compound.
It is used in a ratio of about 0 mole, preferably about 0.0 mole to about 0.3 mole. .

The method for producing a disazo pigment using raw materials as described above can be carried out in accordance with a conventionally known method for producing a disazo pigment. That is, Kame 3@-diku-Lopenzidine was tetrazotized according to a conventional method, and on the other hand.

According to the method of the present invention, a subsoaking solution is prepared according to a conventional method using a mixture consisting of a compound of the above-mentioned general formula (RI) and an acetoacedoanilide compound, and Fi Nagisa is mixed and coupled according to a conventional method. A disazo pigment with improved heat resistance can be obtained.Of course, the pigment can be treated by adding various water-soluble resins, surfactants, and other additives during or after the coupling. During or after coupling, various metal salts are added to convert the carboxyl group or sulfonic acid group of the pigment into metals such as sodium, potassium, barium, calcium, magnesium, manganese, strontium, aluminum, etc. You can also substitute salt.

Disazo noodle preparation obtained by the method of the present invention as described above,
It has the same clarity as conventional disazo pigments,
One of the conventional disazo pigments suffers from a significant decrease in coloring power and dullness of color when coloring rubber, whereas the disazo pigment according to the present invention overcomes these drawbacks. The disazo pigments according to the invention are also greatly improved for use in paints and printing inks. In other words, when disazo pigments are used in paints and printing inks, the pigment is transferred from an aqueous pigment paste to an organic phase by a flushing process, but conventional disazo pigments undergo pigment particle growth during this flushing process. This caused a significant decrease in tinting strength, but the coloring strength of the pigments according to the present invention was not corrected during flushing. Even with increasing degrees of strength, these defects do not occur at all, giving excellent printing inks and coatings.

Next, the present invention will be specifically explained with reference to Examples.

Note that the middle part of the text or the end of the text is based on weight unless otherwise specified.

Example 1 17A part of 3.31-dichlorobenzidine is tetrazotized according to a conventional method to obtain a detrazonium salt solution.

On the other hand, 26.7 parts of acetoaceto-0-toluidide,
and 2.5 parts of N,N'-bis-(2-carboxyphenyl)malonamide according to a conventional method.

Both liquids are mixed and coupled, the resulting pigment is filtered,
Washing with water, rolling, and grinding yielded 46 parts of the disazo pigment of the present invention.

1 part of the above pigment, 0.9 part of rubber, 0.1 part of stearic acid, and the following compound 100@ were rolled at a temperature of 2.
0-50℃, roll spacing 1. Knead the mixture 10 times with an 8-inch ζ kissing roll (the product thus obtained is called a dark crepe). Five parts of this dark-colored crepe and 50 parts of the following compound were kneaded 10 times in the same manner as above to prepare a light-colored crepe. This light-colored crepe was heated under the conditions of 160±1℃, 20okyAA, and 1cm of shore.
When vulcanization was carried out for 0 minutes, a vulcanized rubber sheet with a clear and deep color was obtained. For comparison, Pigment Yellow 14 (3,3'-dichlorobenzidine and acetoacetate)
When a disazo pigment synthesized from 〇-toluidide) was similarly tested in place of the pigment according to the present invention, the coloring strength was significantly lowered and a rubber sheet with a dull color tone was obtained. .

Note 8BR 1507 31.0 parts Zinc white
1.0 part stearic acid 0.4 part light calcium carbonate 31.0 mm 100 titanium
4.0 parts Vulcanization accelerator 1.2 Metropolitan sulfur Yellow 1.0 parts Soybean Example 2 N,N'-bis-(2-carboxy 7
N,N'-bis-(3
-sulfophenyl) malonamide t * a N, N”
-His-(B-hydroxyphenyl)malonand2
Using 5 parts and otherwise following the same procedure as in Example 1, a heat-resistant Arashiyohime disazo pigment similar to that in Example 1 was obtained.

Example 3 In place of acetoaceto-〇-toluidide in Example 1, 26.7 parts of acetoaceto-P-)luidide was used, and in place of N,1/-bis-)2-carboxyphenyl)malonamide, N , N'-(3-tik boxyphenyl) malonando and 25 parts of the same as in Example 1, except that a disazo glaze having good heat resistance similar to that in Example 1 was obtained.

Example 4 17.6 parts of 3.3''-dichlorobenzidine is tetrazotized according to a conventional method to obtain a □tetrazonium salt solution.

On the other hand, 24.7 parts of acetoacedoanilide and N, ♂
- bis(2-carboxyphenyl) malonamide z,
A subsoaking solution is obtained according to a conventional method. Both liquids were mixed and coupled, and the resulting pigment was filtered through a V-filter and washed with water to obtain a water-containing presscake with a solid content of 44 parts.

The above pigment press cake was added to 300 parts of an offset ink face, and flushing was carried out while mixing at a temperature of 60° C. or less in a 7 lacquer, followed by separation and removal of moisture to obtain an offset ink. When this ink was spread on black art paper and heat-treated at 200° C. for 60 seconds, no change occurred in color tone, tinting strength, transparency, etc. When this ink was measured with a spread meter (manufactured by Toyo Seiki, load (acrylic) LTSR, sample volume 0.5ee), the flow value was 27.
It was 7. On the other hand, when a disazo pigment (Pigment Yellow 12) produced from 3.3'-dichlorobenzidine and acetoacedoanilide was heat-treated in the same manner as above, the color tone became extremely opaque to the extent that it was not practical. Quality has deteriorated. Moreover, the flow value was 198.

Claims (1)

[Scope of Claims] 3. A method for producing an azo pigment comprising coupling a tetrazotized product of 31-dichlorobenzidine to an acetoacedoanilide compound, wherein about 1 to 50% of the acetoacedoanilide compound is Molch has the following general formula (
A method for producing a disazo pigment, characterized in that it contains a compound represented by 1). (However, X in humans is a carboxyl group, a sulfonic acid group, a hydroxyl group, or a metal salt thereof.