JP5913291B2 - Water-soluble azo dye, dye composition containing the same, and dyeing method using them - Google Patents

Description

  The present invention relates to a water-soluble azo dye and a dye composition containing the same. More specifically, the present invention relates to a disazo compound, a copperated disazo compound that is a copper complex thereof, or a salt thereof, and a dye composition that includes a copperated disazo compound or a salt thereof and another dye compound or a salt thereof. The present invention also relates to a dyeing method using these water-soluble azo dyes or dye compositions.

  Conventionally, as a dye for dyeing a cellulosic fiber material containing a papermaking material from a solid blue color to a purple color, C.I. I. Direct Blue 15, C.I. I. Direct Blue 200, C.I. I. Direct Blue 202, C.I. I. Direct Blue 203 and the like are well known. These dyes are frequently used in the paper industry for dyeing clothing and dyeing paper pulp as dyes for cotton and rayon. Moreover, the said dye is generally manufactured using dianisidine as a main raw material.

  In particular, in the field of dyeing papermaking materials, there is a technique for making the paper appear whiter than optically pure white by dyeing with a small amount of blue dye or purple dye. This dyeing method is called bluing or bluing, and generally a blue to purple direct dye is used. The dye for bluing is required to have characteristics such that the dye and the dye solution are stable during storage, the dyed color is clear and fastness to light is good. Conventionally, as a dye for bluing, a blue dye produced using dianisidine as a raw material has been frequently used because of its clear color.

  However, a common problem with these dyes is that dianisidine, which is used as the main raw material, is the first class of specified chemical substances in Japan's Industrial Safety and Health Act (which is highly harmful and causes severe health problems for workers. Chemical substances that may have a risk). For this reason, the production process of each dye is strongly regulated by the use of dianisidine, which is a limiting factor for improving safety and health management such as working under extremely strict protective equipment and improving production efficiency.

  Examples of blue to purple dyes or direct dyes produced from raw materials other than dianisidine include C.I. I. Direct Blue 67, C.I. I. Direct Blue 78, C.I. I. Direct Blue 106, C.I. I. Direct Blue 108, C.I. I. Direct Violet 9, C.I. I. Direct Violet 35, C.I. I. Direct Violet 51 etc. are mentioned. However, all the dyes are clearly inferior in dyeing performance such as sharpness, dyeability, fastness, heat resistance and the like as compared with the above-mentioned dianisidine dyes. Therefore, these dyes are also not suitable as dyes for dyeing a cellulosic fiber material containing papermaking materials from a solid blue color to a purple color or as a dye for bluing.

  Accordingly, vivid and fast-dyed blue to purple dyes or direct dyes other than these existing dyes have been strongly desired for many years by the dye manufacturing industry, paper industry and dyeing industry. However, excellent dyes that satisfy all these requirements have not yet been obtained.

  For example, JP-B-64-5623 (Patent Document 1) and JP-A-7-18192 (Patent Document 2) describe a dye compound represented by the following formula (5) as a blue dye not using dianisidine. Has been.

  By using this dye, it is possible to dye the papermaking material into a clear blue with good levelness. However, since the hue of this dye is greenish, no medium blue color is obtained, and its use is limited. In addition, both the dyeability and the color value are poor, and there is a disadvantage that the suitability for bluing alone is low.

  In addition, dye compositions used as direct dyes have high dye solution stability from the viewpoint of actual dyeing workability in addition to dyeing performance to a desired color, that is, a certain amount of time has elapsed during storage. However, it is required that the crystals hardly precipitate and the color tone does not change. However, a dye composition containing a direct dye that can obtain an appropriate reddish blue color for bluing and has excellent stability during storage has not been obtained so far.

  JP-A-59-140263 (Patent Document 3) describes a compound represented by the following formula (6) as a disazo compound used in a dye composition. However, this document does not describe a disazo compound having a phenyl group substituted with a carboxyl group.

Japanese Patent Publication No. 64-5623 Japanese Patent Laid-Open No. 7-18192 JP 59-140263 A

One of the objects of the present invention is a dye that satisfies dyeing property, fastness, heat resistance, sharpness, etc. without using dianisidine that falls under the category 1 of the specified chemical substances in the Japanese Industrial Safety and Health Act. And a staining method using the same.
Another object of the present invention is to dye cellulosic fiber materials, especially pulp and other papermaking materials, in a robust, high concentration, more neutral blue to purple color, and in terms of safety and health, resource saving and environmental pollution. And an earth-friendly dye and a dyeing method using the same.
Still another object of the present invention is to provide a reddish blue dye composition which is suitable for bluing dyes and has good dyeing characteristics by combining a blue direct dye and a purple direct dye that do not use dianisidine as a raw material. It is to provide the staining method used.

The present inventors have found that the above-mentioned problems can be solved by using a disazo compound represented by the following formula (1) or a salt thereof.
In addition to the following formula (4), which is one form of a copper complex of a disazo compound represented by the following formula (1), or a salt thereof, the present inventors have added a compound represented by the following formula (5) (above By using a combination of two direct dyes of a salt thereof or a salt thereof, a reddish blue dye composition suitable for bluing dyes and having good dyeing characteristics can be obtained. I found out.

［式中、Ａｒ１は、アゾ基に対してオルソの位置がヒドロキシ基又はメトキシ基により置換されており、さらにカルボキシル基で置換されているフェニル基を表し、Ａｒ２は、アゾ基に対してオルソの位置がヒドロキシ基又はメトキシ基により置換されており、さらにスルホン酸基、スルホンアミド基又はカルボキシル基で置換されていてもよいフェニル基を表す。］
［２］上記［１］項に記載の式（１）で表されるジスアゾ化合物の銅錯体又はその塩。
［３］銅錯体が、下記式（２）で表される銅化ジスアゾ化合物である上記［２］項に記載の銅錯体又はその塩。

［式中、Ｘは、スルホン酸基、スルホンアミド基又はカルボキシル基を示す。］
［４］銅錯体が、下記式（３）で表される銅化ジスアゾ化合物である上記［２］又は［３］項に記載の銅錯体又はその塩。

［式中、Ｘは、スルホン酸基、スルホンアミド基又はカルボキシル基を示す。］
［５］Ｘが、スルホンアミド基又はカルボキシル基である上記［３］又は［４］項に記載の銅錯体又はその塩。
［６］下記式（４）で表される化合物若しくはその塩、及び下記式（５）で表される化合物若しくはその塩の２種の直接染料を含有する染料組成物。

［７］式（４）で表される化合物若しくはその塩と式（５）で表される化合物若しくはその塩との組成比（質量基準）が、５：９５〜９０：１０である上記［６］項に記載の染料組成物。
［８］上記［１］乃至［５］項のいずれか一項に記載の化合物又はその塩、あるいは上記［６］又は［７］項に記載の染料組成物の溶液を用いることを特徴とするセルロース系繊維の染色法。
［９］上記［８］項に記載の染色法で染色された染色物。
［１０］上記［１］乃至［５］項のいずれか一項に記載の化合物又はその塩を色素として含有するインク組成物。
［１１］さらに、水溶性有機溶剤を含有する上記［１０］項に記載のインク組成物。
［１２］上記［１０］又は［１１］項に記載のインク組成物で着色された着色体。That is, each aspect of the present invention is as follows.
[1] A disazo compound represented by the following formula (1) or a salt thereof.

[In the formula, Ar1 represents a phenyl group substituted at the ortho position with respect to the azo group by a hydroxy group or a methoxy group, and further substituted with a carboxyl group, and Ar2 represents an ortho group with respect to the azo group. The position represents a phenyl group which is substituted with a hydroxy group or a methoxy group and which may be further substituted with a sulfonic acid group, a sulfonamide group or a carboxyl group. ]
[2] A copper complex of a disazo compound represented by the formula (1) according to the above [1] or a salt thereof.
[3] The copper complex or the salt thereof according to the above [2], wherein the copper complex is a copperated disazo compound represented by the following formula (2).

[Wherein, X represents a sulfonic acid group, a sulfonamide group or a carboxyl group. ]
[4] The copper complex or the salt thereof according to the above [2] or [3], wherein the copper complex is a copperated disazo compound represented by the following formula (3).

[Wherein, X represents a sulfonic acid group, a sulfonamide group or a carboxyl group. ]
[5] The copper complex or the salt thereof according to the above [3] or [4], wherein X is a sulfonamide group or a carboxyl group.
[6] A dye composition containing a compound represented by the following formula (4) or a salt thereof, and two direct dyes of the compound represented by the following formula (5) or a salt thereof.

[7] The above-mentioned [6], wherein the composition ratio (mass basis) of the compound represented by formula (4) or a salt thereof and the compound represented by formula (5) or a salt thereof is 5:95 to 90:10 ] The dye composition of a term.
[8] A compound or a salt thereof according to any one of [1] to [5] above, or a solution of the dye composition according to [6] or [7] above. Cellulosic fiber dyeing method.
[9] A dyed product dyed by the dyeing method according to the above [8].
[10] An ink composition containing the compound or a salt thereof according to any one of [1] to [5] above as a coloring matter.
[11] The ink composition according to item [10], further including a water-soluble organic solvent.
[12] A colored body colored with the ink composition according to the above [10] or [11].

  The disazo compound represented by the above formula (1) of the present invention, the copperated disazo compound that is a copper complex thereof, or a salt thereof does not correspond to dianisidine, which is a first class of specific chemical substances, and a production method that does not use it. It is obtained by. These compounds or their salts are useful as dyes for dyeing a cellulosic fiber material containing a papermaking material as a water-soluble azo dye from a high-brightness, high-concentration, fast, medium blue to purple. Furthermore, the disazo compound, the copperated disazo compound or the salt thereof of the present invention is highly dyeable, so that it is less colored with white water, hardly affected by the water hardness, less discoloration, and high solution stability. It also has advantages. These compounds or their salts are superior to the dyes described in JP-A-59-140263, particularly in terms of dyeability, sharpness, solution stability, and blending stability with other existing dyes. With respect to the adherence and color value, the dyes are superior to the dyes described in JP-B-64-5623 and JP-A-7-18192.

  In particular, the compound represented by the above formula (4) according to the present invention (a copper complex of a disazo compound) or a salt thereof and the compound represented by the above formula (5) (a copper complex of a disazo compound) or a salt thereof 2 The dye composition containing the direct dyes of the seeds has a well-balanced dyeing property in which crystals do not precipitate, the solution stability is good, and when the cellulose fiber material is dyed, it is clear and has strong fastness such as light resistance and water resistance. A reddish blue dyed product can be obtained.

The disazo compound represented by the above formula (1) according to the present invention will be described.
In the formula, Ar1 represents a phenyl group substituted at the ortho position with respect to the azo group by a hydroxy group or a methoxy group and further substituted with a carboxyl group, and Ar2 represents an ortho position with respect to the azo group. Represents a phenyl group which is substituted with a hydroxy group or a methoxy group and which may be further substituted with a sulfonic acid group, a sulfonamide group or a carboxyl group.

In Ar1, the substitution position of the carboxyl group is not particularly limited as long as it is a substitutable position.
Ar2 is preferably a phenyl group substituted with a sulfonamide group or a carboxyl group among a sulfonic acid group, a sulfonamide group, and a carboxyl group. These substituents further impart water solubility. In Ar2, the substitution position of the sulfonic acid group, sulfonamide group or carboxyl group is not particularly limited as long as substitution is possible, and any of ortho, meta, and para positions can be taken with respect to the hydroxy group or methoxy group.

  Although the example of the manufacturing method of the disazo compound represented by the said Formula (1) is demonstrated below, the manufacturing method of the said compound is not limited to the following method.

Aromatic amine compounds represented by the following formulas (7) and (8), which are known per se or obtained by applying known methods for producing similar compounds, are diazotized by a conventional method, and then commercially available. A dinaphthylamine derivative represented by the following formula (9) and a disazo compound represented by the above formula (1) by subjecting to an alkaline diazo coupling reaction at, for example, 5 to 40 ° C., preferably 10 to 25 ° C. Can be obtained.
Ar1-NH ₂ (7)
[Wherein Ar1 has the same meaning as Ar1. ]
Ar2-NH ₂ (8)
[Wherein Ar2 has the same meaning as Ar2. ]

  The present invention also includes a copper complex of a disazo compound represented by the above formula (1) or a salt thereof. Examples of the copper complex include a monocopper complex and a dicopper complex. Preferably, the above formula (2) [wherein X represents a sulfonic acid group, a sulfonamide group or a carboxyl group. ] The copperated disazo compound which is a dicopperation complex represented by these is mentioned. In this copper complex, the preferred substitution position of the carboxyl group in Ar1, the preferred group among the sulfonic acid group, the sulfonamide group and the carboxyl group in Ar2 are the same as those of the disazo compound represented by the above formula (1).

  This copper complex can be manufactured according to a well-known method using the disazo compound represented by the said Formula (1). As an example, this copper complex is obtained by adding a copper complex compound composed of copper sulfate and aqueous ammonia and / or alkanolamine and / or hexamethylenetetramine to the disazo compound represented by the above formula (1). It can be obtained by carrying out the copperation reaction at 100 ° C, preferably 90-100 ° C. In this reaction, the methoxy group undergoes a demethylation reaction and is copperated.

  The disazo compound represented by the above formula (1) or a copper complex thereof can be obtained from the reaction solution by an ordinary salting out method or acid precipitation method. It can also be obtained by spray drying the reaction solution as it is. Furthermore, the reaction solution can be used as a solution by adding the solubilizer and stabilizer such as urea, alkanolamine, alkylamine, and ε-caprolactam as it is or after desalting and concentrating the reaction solution.

  The disazo compound represented by the above formula (1) or the copper complex thereof thus obtained exists in the form of a free acid or a salt thereof. Of these, the salt form is preferred. Examples of the salt include alkali metal salts, alkaline earth metal salts, alkylamine salts, alkanolamine salts, and the like, and alkali metal salts such as sodium salts, potassium salts, and lithium salts are particularly preferable. These salts are obtained by a normal salt-forming reaction.

  The compound represented by the above formula (4) (a copper complex of a disazo compound) or a salt thereof, which is one form of the copper complex of the disazo compound represented by the above formula (1), is represented by the above formula (5). It can be used as a dye composition containing two kinds of direct dyes in combination with a compound (a copper complex of a disazo compound) or a salt thereof. This dye composition is a reddish blue dye composition having clear and good dyeing characteristics, and is suitably used for bluing applications.

  The compound represented by the above formula (4) can be obtained by applying a known production method for related compounds. For example, this copper complex is obtained by subjecting 3-amino-4-methoxybenzoic acid to a diazotization reaction and adding this to a solution of 7,7′-iminobis (4-hydroxynaphthalene-2-sulfonic acid) to form a disazo compound. Then, this is added to a copper complex solution prepared by adding diethanolamine and 2-methylaminoethanol to a copper sulfate aqueous solution, and then, a copperation reaction is performed.

  Examples of the salt of the compound represented by the above formula (4) include alkali metal salts, alkaline earth metal salts, alkylamine salts, alkanolamine salts, and the like. Of these, alkali metal salts such as sodium salt, potassium salt and lithium salt, or lower alkanolamine salts such as diethanolamine salt are particularly preferable. These salts are obtained by a normal salt-forming reaction.

  The compound represented by the above formula (5) or a salt thereof is C.I. I. It is a compound known as Direct Blue 273. As this copper complex or its salt, what was manufactured based on well-known literature may be used, or commercially available dye may be used.

  In the dye composition containing the compound represented by the above formula (4) or a salt thereof, and the two direct dyes of the compound represented by the above formula (5) or a salt thereof, represented by the above formula (4). The composition ratio (mass basis) of the compound represented by the above formula (5) or a salt thereof is preferably 5:95 to 90:10.

  The dye composition containing two types of direct dyes of the compound represented by the above formula (4) or a salt thereof and the compound represented by the above formula (5) or a salt thereof includes the compound (4) or a salt thereof. In addition to the salt and the compound (5) or a salt thereof, other dyes may be contained in order to adjust the color tone, or to adjust fastness, dyeing characteristics, and the like. Moreover, this dye composition may contain a pigment, a dyeing agent, etc. for the same purpose. Further, the dye composition may contain a solvent such as water, salts such as sodium chloride, oily components, and the like.

  The disazo compound, the copperated disazo compound or their salts according to the present invention can be used for dyeing cellulose fiber materials. For example, these compounds or their salts are used to sharpen paper, pulp and other dyeing methods under normal dyeing conditions, surface coating dyeing methods including size press method and coating method, or internal dyeing methods. It is possible to obtain a dyed product dyed in a more neutral blue color to purple color, which has high properties and excellent light resistance and water resistance. In addition, using these compounds or their salts, natural or artificial cellulose fibers that are cellulose fiber materials and cellulose-containing fibers, for example, dyeing methods under ordinary dyeing conditions such as cotton, rayon, etc., for example, dip dyeing, continuous dyeing or By a printing method or the like, it can be dyed blue that is fast against sunlight and washing. The dyed product here includes, in addition to the dyed cellulose fiber material, a film obtained by processing the fiber material, a building material board, a nonwoven fabric, and the like.

  In particular, a dyeing method using a solution of a dye composition containing a compound represented by the above formula (4) or a salt thereof and two direct dyes of the compound represented by the above formula (5) or a salt thereof. A dyed product can be obtained. By using this dye composition, it becomes possible to dye reddish blue. As the solution, an aqueous solution is preferable. The solution is obtained by dissolving or diluting the dye composition.

  A colored body can be obtained by using the disazo compound, the copperated disazo compound or a salt thereof of the present invention as a pigment in an ink composition for paper or fiber. The ink composition may contain a water-soluble organic solvent such as methanol, ethanol, isopropanol, hydroxyethylmethylamine, ethanolamine, diethanolamine, triethanolamine and the like. The disazo compound, the copperated disazo compound or a salt thereof of the present invention is preferable as a pigment in the ink composition for fibers. In this case, the ink composition may contain a dispersant such as a high molecular sulfonic acid, preferably a formalin condensate of aromatic sulfonic acid, a formalin condensate of lignin sulfonic acid.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.
In the examples, “parts” and “%” mean mass parts and mass%, respectively. The sulfonic acid group in each formula is represented in a free form.

Example 1
After adding 11 parts of 35% hydrochloric acid to 70 parts of water at 18-22 ° C., a solution containing 7.25 parts of 3-amino-4-methoxybenzoic acid was cooled to 5 ° C., and 3.14 parts of sodium nitrite. Was added to the diazotization reaction for 30 minutes to obtain a reaction solution. To a solution obtained by adding 10 parts of 7,7′-iminobis (4-hydroxynaphthalene-2-sulfonic acid) and 5.8 parts of sodium carbonate to 150 parts of water at 18 to 22 ° C., the above reaction solution was adjusted from pH 8.5. To maintain 9.5, sodium carbonate was added over 1 hour, and the mixture was further stirred for 3 hours, and then 25 parts of sodium chloride was added and stirred overnight. The solution was acidified by adding 17 parts of 35% hydrochloric acid, and the precipitate (compound represented by the following formula (10)) was collected by filtration.

Example 2
A solution obtained by adding 3.41 parts of 3-amino-4-methoxybenzoic acid and 4.71 parts of 35% hydrochloric acid to 100 parts of water at 18 to 22 ° C. is cooled to 5 ° C., and 1.46 parts of sodium nitrite is added. The reaction solution was obtained by diazotization reaction for 2 hours. A solution prepared by adding 12.22 parts of 7,7′-iminobis (4-hydroxynaphthalene-2-sulfonic acid) to 160 parts of water at 18 to 22 ° C., adjusted to pH 7.0 with sodium carbonate, and cooled to 5 ° C. The reaction solution was added over 2 hours while adding sodium carbonate so as to maintain pH 7.0 to 7.5, and then further stirred for 5 hours. To 80 parts of water, 3.76 parts of 3-amino-4-hydroxybenzenesulfonic acid amide and 4.88 parts of 35% hydrochloric acid are added, the solution is cooled to 0 ° C., and 1.46 parts of sodium nitrite is added for 2 hours. The reaction solution obtained by the diazotization reaction was added to the reaction solution after stirring for 5 hours in 2 hours while adding sodium carbonate so as to maintain pH 7.0 to 8.0. Further, the mixture was stirred for 2 hours while adding sodium carbonate so as to maintain pH 8.0 to 9.0. To this reaction solution, 100 parts of sodium chloride was added for salting out, and the precipitate (compound represented by the following formula (11)) was collected by filtration.

Example 3
The disazo compound (10) obtained in Example 1 was added to a copper complex solution prepared by adding 17.16 parts of diethanolamine and 6.09 parts of 2-methylaminoethanol to an aqueous solution of 10.08 parts of copper sulfate and 20 parts of water. 15 parts were added, and the copperation reaction was performed at 95 to 100 ° C. until no raw material was observed (about 9 hours). Thereto was added 10% of salt with respect to the liquid amount for salting out, and the precipitate was collected by filtration and dried to obtain a dye (compound represented by the following formula (4)) in the form of a free acid. The maximum absorption wavelength λmax of the aqueous dye solution (hereinafter, λmax means a measured value in the aqueous solution) was 556 nm.

Example 4
The disazo compound (11) obtained in Example 2 was added to a copper complex solution prepared by adding 17.16 parts of diethanolamine and 6.09 parts of 2-methylaminoethanol to an aqueous solution of 10.08 parts of copper sulfate and 20 parts of water. 16.05 parts were added, and a copperization reaction was performed at 95 to 100 ° C. until no raw material was observed (about 9 hours). Thereto was added 10% of salt with respect to the liquid amount for salting out, and the precipitate was collected by filtration and dried to obtain a dye (compound represented by the following formula (13)) in the form of a free acid. Λmax of this aqueous dye solution was 559 nm.

Example 5
1 part of the copperated disazo compound represented by the formula (4) obtained in Example 3 is dissolved in 1000 parts of water to prepare a dye bath. After adding 300 parts of beating kraft pulp (30 parts of absolutely dry pulp, degree of beating 35SR) to this dye bath and stirring for 15 minutes at room temperature, 1 part of rosin size (30% aqueous solution) was added, and further stirring for 10 minutes. 3 parts of crystalline aluminum sulfate was added and stirred for 20 minutes. When the dyed pulp was made, a medium and clear purple paper was obtained.

Comparative Example 1
Instead of the copperated disazo compound represented by the formula (4) obtained in Example 3, the following known dyes A, B or C were used, and the pulp was dyed and paper-made in the same manner as in Example 5. To obtain a dyed product.

Known Dye A: Purple Dye (CI Direct Violet 51) which is currently widely used

Known Dye B: Purple Dye (CI Direct Violet 35), which is currently widely used

Known Dye C: Purple Dye (CI Direct Violet 9) currently in wide use

Test example 1
The dyeings obtained in Example 5 and Comparative Example 1 were compared in terms of hue, sharpness, thermal discoloration and light fastness, and the results are shown in Table 1.
The heat discoloration of the dyed product is heat treated using a cylinder dryer at 80 to 100 ° C. for 10 minutes, and the color difference from the untreated dyed product is measured using a colorimeter (Color Eye 3000 manufactured by Macbeth Co.). evaluated.
The light fastness of the dyed product is evaluated in accordance with JIS L0842 “Testing method for fastness to dyeing with carbon arc lamp” and using the blue scale specified in JIS L0841 “Testing method for fastness to dyeing with sunlight”. did. Larger numbers indicate better light fastness.

The known purple dye A, which is widely used at present, has a medium-purple hue, but is dark and lacks vividness, has a large thermal discoloration, and has a poor light fastness of 1st grade.
The known purple dye B, which is widely used at present, has a very blue hue, strong darkness, lack of vividness, large thermal discoloration, and poor light fastness of first grade.
The known purple dye C, which is widely used at present, has a slightly blue hue, strong darkness, lack of vividness, and excellent thermal discoloration, but has a poor light fastness of 1st grade.
On the other hand, the dye of the present invention (dye of the above formula (4)) was purple with a moderate hue, excellent thermal discoloration, excellent light fastness of 3-4 grade, and higher sharpness. Further, this dye is superior to the known purple dyes A, B, and C in that it has characteristics such as being hardly affected by metal ions in dyeing water.

Example 6
After dissolving 10 parts of the copperated disazo compound represented by the formula (13) obtained in Example 4 in 1000 parts of water and adding 2 parts of an anionic surface sizing agent, the solution pH was adjusted to 8.0. A size press coating solution was obtained. When this liquid was sent to a size press machine and a weak paper with a Steecht size of 7 seconds was colored, a clear, slightly reddish purple paper with good leveling was obtained.

Comparative Example 2
Instead of the copperated disazo compound represented by the formula (13) obtained in Example 4, the above-mentioned known dye A, B or C is used, and dyeing is carried out in the same manner as in Example 6 to obtain a dyed product. It was.

Test example 2
The dyeings obtained in Example 6 and Comparative Example 2 were compared in terms of hue, sharpness, and thermal discoloration, and the results are shown in Table 2.

The known purple dye A, which is widely used at present, has a moderately purple hue, but has a large thermochromic property and low sharpness.
The known purple dye B, which is widely used at present, has a very bluish hue, a large thermochromic property, and a low sharpness.
The currently used purple dye C, which is widely used, has a slight bluish hue and excellent thermal discoloration, but has low sharpness.
On the other hand, the dye of the present invention (dye of the above formula (13)) has a neutral purple hue, excellent thermal discoloration, and is clearer than the known purple dyes A, B, and C.

Example 7
The diethanolamine salt of the compound represented by the above formula (4) obtained in Example 3 and the diethanolamine salt of the compound represented by the above formula (5) were mixed at the following ratio, water was added, and the dye concentration A 10% aqueous dye composition was prepared. Each aqueous dye composition was stored at room temperature for one week, and no crystal was observed in any of the aqueous dye compositions, and the aqueous dye compositions were stable.
<Combination ratio>
Compound (4) 5%: Compound (5) 95%
Compound (4) 10%: Compound (5) 90%
Compound (4) 20%: Compound (5) 80%
Compound (4) 40%: Compound (5) 60%
Compound (4) 60%: Compound (5) 40%
Compound (4) 90%: Compound (5) 10%

Comparative Example 3
A diethanolamine salt of a compound represented by the following formula (14) and a diethanolamine salt of a compound represented by the above formula (5) are mixed in the following ratio, water is added, and an aqueous dye composition having a dye concentration of 10% is added. It was created. Each aqueous dye composition was stored at room temperature for one week, but crystals were precipitated in any of the aqueous dye compositions.
<Combination ratio>
Compound (14) 5%: Compound (5) 95%
Compound (14) 10%: Compound (5) 90%
Compound (14) 20%: Compound (5) 80%
Compound (14) 40%: Compound (5) 60%
Compound (14) 60%: Compound (5) 40%
Compound (14) 90%: Compound (5) 10%

Comparative Example 4
The diethanolamine salt of the compound represented by the above formula (6) and the diethanolamine salt of the compound represented by the above formula (5) are mixed in the following ratio, water is added, and an aqueous dye composition having a dye concentration of 10% is added. It was created. In any aqueous dye composition, crystals were precipitated immediately after mixing.
<Combination ratio>
Compound (6) 5%: Compound (5) 95%
Compound (6) 10%: Compound (5) 90%
Compound (6) 20%: Compound (5) 80%
Compound (6) 40%: Compound (5) 60%
Compound (6) 60%: Compound (5) 40%
Compound (6) 90%: Compound (5) 10%

Comparative Example 5
The diethanolamine salt of the compound represented by the following formula (15) (CI Direct Violet 51) and the diethanolamine salt of the compound represented by the above formula (5) are mixed in the following ratio and water is added, An aqueous dye composition having a dye concentration of 10% was prepared. Each aqueous dye composition was stored at room temperature for one week, but crystals were precipitated in any of the aqueous dye compositions.
<Combination ratio>
Compound (15) 5%: Compound (5) 95%
Compound (15) 10%: Compound (5) 90%
Compound (15) 20%: Compound (5) 80%
Compound (15) 40%: Compound (5) 60%
Compound (15) 60%: Compound (5) 40%
Compound (15) 90%: Compound (5) 10%

Example 8
25 parts of the diethanolamine salt of the compound represented by the above formula (4) and 75 parts of the diethanolamine salt of the compound represented by the above formula (5) were mixed and water was added to prepare an aqueous dye composition having a dye concentration of 10%. Created.

Comparative Example 6
C. is a dianisidine blue direct dye. I. An aqueous solution of Direct Blue 201 (dye concentration 10%) was prepared.

Comparative Example 7
A disazo blue direct dye which is a non-dianisidine dye; I. An aqueous solution of Direct Blue 67 (dye concentration 10%) was prepared.

Production of dyed product 0.05 part of the dye aqueous solution of Example 8, Comparative Example 6 or Comparative Example 7 was dissolved in 1000 parts of water to prepare a dye bath. After adding 300 parts of beaten kraft pulp (30 parts of absolutely dry pulp, degree of beating 35SR) to this dye bath and stirring for 15 minutes at room temperature, 1 part of rosin size (30% aqueous solution) was added and stirred for another 10 minutes. 3 parts of crystalline aluminum sulfate was added and stirred for 20 minutes. When the dyed pulp was made, a clear reddish blue paper was obtained.

Test example 3
Each aqueous dye solution and its dyed product were tested for solution stability, color tone, and light fastness, and the evaluation results are shown below.
The solution stability of the aqueous dye solution was evaluated by visual observation of crystal precipitation while the aqueous dye solution was stored at room temperature.
The light fastness of the dyed product was evaluated in the same manner as described above.

  As is apparent from the evaluation results regarding the dye of Comparative Example 7, the blue direct dye that does not use dianisidine that is currently used has poor light fastness and solution stability as a dye for bluing in the papermaking field. . On the other hand, from the result of the dye of Example 8, the dye composition containing the two direct dyes of the present invention does not use dianisidine as a raw material, but the reddish blue color as in Comparative Example 6 using a dye using dianisidine as a raw material. It was found that the dye has good light fastness and solution stability, and is therefore excellent as a dye for paper bluing.

  The disazo compound according to the present invention, the copper complexed disazo compound, or a salt thereof, is a water-soluble azo dye that converts a cellulosic fiber material containing a papermaking material from a high-brightness, high-concentration, robust, medium blue to purple. It is useful as a dye for dyeing. Further, these copperated disazo compounds or their salts are suitably used as a dye for bluing because a reddish blue dye composition having clear and good dyeing characteristics can be obtained.

Claims (12)

The disazo compound or its salt represented by following formula (1).

[In the formula, Ar1 represents a phenyl group substituted at the ortho position with respect to the azo group by a hydroxy group or a methoxy group, and further substituted with a carboxyl group, and Ar2 represents an ortho group with respect to the azo group. The position represents a phenyl group which is substituted with a hydroxy group or a methoxy group and which may be further substituted with a sulfonic acid group, a sulfonamide group or a carboxyl group. ]   The copper complex of the disazo compound represented by Formula (1) of Claim 1, or its salt. The copper complex or a salt thereof according to claim 2, wherein the copper complex is a copperated disazo compound represented by the following formula (2).

[Wherein, X represents a sulfonic acid group, a sulfonamide group or a carboxyl group. ] The copper complex or a salt thereof according to claim 2 or 3, wherein the copper complex is a copperated disazo compound represented by the following formula (3).

[Wherein, X represents a sulfonic acid group, a sulfonamide group or a carboxyl group. ]   The copper complex or a salt thereof according to claim 3 or 4, wherein X is a sulfonamide group or a carboxyl group. A dye composition comprising a compound represented by the following formula (4) or a salt thereof, and two direct dyes of the compound represented by the following formula (5) or a salt thereof.

  The composition ratio (mass basis) of the compound represented by the formula (4) or a salt thereof and the compound represented by the formula (5) or a salt thereof is 5:95 to 90:10. Dye composition.   A method for dyeing a cellulosic fiber, comprising using the compound according to any one of claims 1 to 5 or a salt thereof, or the solution of the dye composition according to claim 6 or 7. The dyeing | staining thing of the cellulosic fiber dye | stained with the solution of the compound as described in any one of Claims 1 thru | or 5, or its salt, or the dye composition of Claim 6 or 7 .   An ink composition comprising the compound according to any one of claims 1 to 5 or a salt thereof as a pigment.   The ink composition according to claim 10, further comprising a water-soluble organic solvent. A colored body colored with the ink composition according to claim 10.