JP5172345B2 - New azo compounds - Google Patents

Description

  The present invention relates to a novel azo compound which is used for coloring a polymer material and the like and is a clear magenta colorant having excellent solubility in an organic solvent.

In recent years, a clear magenta colorant having excellent solubility in aromatic solvents such as toluene, ketone solvents such as methyl ethyl ketone, and ester solvents such as ethyl lactate has been used for colorants of polymer materials such as color filters. It is requested.
Azo compounds are known as stable colored compounds and are used for coloring liquid crystal materials and organic polymer materials.
Non-Patent Document 1 discloses the structural formula of the following compound (A) although there is no description of physical properties and the like.

この化合物（Ａ）は、本発明者等の試験によれば、トルエン、メチルエチルケトン、乳酸エチル等の有機溶媒に対する溶解度が低い。
なお、特許文献１では溶解性等に優れたマゼンタ色色素としてアゾ化合物が開示され、実施例１７において下記化合物（Ｂ）が開示されている。

This compound (A) has a low solubility in organic solvents such as toluene, methyl ethyl ketone, and ethyl lactate, according to tests by the present inventors.
In Patent Document 1, an azo compound is disclosed as a magenta color dye having excellent solubility and the like, and in Example 17, the following compound (B) is disclosed.

しかしながら、化合物（Ｂ）の色調は実際には赤色であり、鮮明なマゼンタ色ではない。また、耐光堅牢度も十分に高いとは言えない。
また、非特許文献２において、下記化合物（Ｃ）が開示されている。

However, the color tone of the compound (B) is actually red and not a clear magenta color. Also, it cannot be said that the light fastness is sufficiently high.
In Non-Patent Document 2, the following compound (C) is disclosed.

この化合物（Ｃ）は、本発明者等の試験によれば、トルエン、メチルエチルケトン、乳酸エチル等の有機溶媒に対する溶解度が低く、耐光堅牢度も低い。
特開平５−２１２９７８号公報 ＳＴＮ ＣＨＥＭＬＩＳＴ ＦＩＬＥ ＲＮ：１７０８３１−５３−５ Ｊｏｕｎａｌ ｆｕｅｒ Ｐｒａｋｔｉｓｃｈｅ Ｃｈｅｍｉｅ （Ｌｅｉｐｚｉｇ）（１９８６），３２８（４），４９７−５１４

This compound (C) has low solubility in organic solvents such as toluene, methyl ethyl ketone, and ethyl lactate, and also has low light fastness according to the tests by the present inventors.
JP-A-5-212978 STN CHEMLIST FILE RN: 170831-53-5 Journal fuel Praktische Chemie (Leipzig) (1986), 328 (4), 497-514.

  An object of the present invention is to provide an organic solvent used for coloring and mixing various polymer materials, particularly an aromatic solvent such as toluene, a ketone solvent such as methyl ethyl ketone, and an ester solvent such as ethyl lactate. The present invention provides an excellent azo compound having high solubility in an organic solvent such as a clear magenta color and high light fastness.

As a result of intensive studies to solve the above problems, the present inventors have found that an azo compound having a specific structure is an organic solvent, particularly an aromatic solvent such as toluene, a ketone solvent such as methyl ethyl ketone, and an ester such as ethyl lactate. It has been found that it can be an excellent pigment exhibiting extremely high solubility in a system solvent, having a clear magenta color and high light fastness, and has completed the present invention.
That is, the present invention provides a novel azo compound represented by the following general formula (I).

（式中、Ｒ_１、Ｒ_２はそれぞれ独立して炭素数２以上のアルキル基を表し、Ｒ_３はアルキル基を表し、Ｘはハロゲン原子を表す。）

(In the formula, R ₁ and R ₂ each independently represents an alkyl group having 2 or more carbon atoms, R ₃ represents an alkyl group, and X represents a halogen atom.)

Detailed Description of the Invention

In the general formula (I), R ₁ and R ₂ are alkyl groups having 2 or more carbon atoms, and examples thereof include an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group. Group, linear alkyl group such as n-heptyl group, n-octyl group, iso-propyl group, iso-butyl group, sec-butyl group, tert-butyl group, 3-methylbutyl group, 2-methylbutyl group, 1- Methylbutyl group, 2,2-dimethylpropyl group, 1,2-dimethylpropyl group, 1,1-dimethylpropyl group, 4-methylpentyl group, 3-methylpentyl group, 2-methylpentyl group, 1-methylpentyl group 3,3-dimethylbutyl group, 3,2-dimethylbutyl group, 3,1-dimethylbutyl group, 2,2-dimethylbutyl group, 2,1-dimethylbutyl group, 1,1-dimethylbuty Group, 2,2,1- trimethyl-propyl group, and a branched alkyl group such as 2,1,1- trimethyl-propyl group.
The R _1, R _2, preferably a linear or branched alkyl group having 2 to 8 carbon atoms, straight-chain or branched alkyl group having 3 to 5 carbon atoms, especially branched alkyl group is particularly preferred.

As the alkyl group for R _3, a linear alkyl group such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group, iso-propyl group, iso-butyl group, sec-butyl group, tert-butyl group, 3-methylbutyl group, 2-methylbutyl group, 1-methylbutyl group, 2,2-dimethylpropyl group, 1,2-dimethylpropyl group 1,1-dimethylpropyl group, 4-methylpentyl group, 3-methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, 3,3-dimethylbutyl group, 3,2-dimethylbutyl group, 3 , 1-dimethylbutyl group, 2,2-dimethylbutyl group, 2,1-dimethylbutyl group, 1,1-dimethylbutyl group, 2,2,1-trimethylpropyl group, 2,1,1 -Branched alkyl groups such as trimethylpropyl group. R ₃ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and particularly preferably a linear or branched alkyl group having 1 to 3 carbon atoms.

  Examples of the halogen atom for X include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. X is preferably a chlorine atom or a bromine atom, particularly preferably a chlorine atom.

(Method for producing azo compound)
The example of the manufacturing method of the azo compound represented by general formula (I) of this invention is demonstrated below.
The following general formula (II)

（式中、Ｘは前記定義に同じ）で示されるアニリン類を酸溶媒に溶解した後、ニトロシル硫酸を滴下し、ジアゾ化を行いジアゾ液を得る。
酸溶媒としては、硫酸、リン酸、塩酸、酢酸、プロピオン酸またはこれらの酸の混合物等が使用される。酸溶媒の使用量は、アニリン類に対し同量〜１０倍重量、好ましくは同量〜５倍重量である。

(Wherein X is the same as defined above) is dissolved in an acid solvent, nitrosylsulfuric acid is added dropwise, and diazotization is performed to obtain a diazo solution.
As the acid solvent, sulfuric acid, phosphoric acid, hydrochloric acid, acetic acid, propionic acid or a mixture of these acids is used. The amount of the acid solvent used is the same amount to 10 times the weight, preferably the same amount to 5 times the weight of the aniline.

The amount of nitrosylsulfuric acid used is 0.8 to 1.2 times mol, preferably 0.95 to 1.1 times mol with respect to the anilines represented by the general formula (II). -10 to 30 ° C, preferably -5 to 10 ° C, and the reaction time is 0.5 to 10 hours, preferably 1 to 5 hours.
Next, the obtained diazo liquid is converted into the following general formula (III)

(式中、Ｒ_１、Ｒ_２、Ｒ_３は前記定義に同じ)で示される化合物とカップリング反応させる。
カップリング反応は通常、酸性条件下、水性溶媒中で行われる。例えば、硫酸、リン酸、塩酸、酢酸、プロピオン酸またはこれらの酸の混合物等の水性溶媒中、前記一般式（III）で示される化合物を溶解または分散し、上記ジアゾ液を混合することにより実施される。
前記一般式（III）で示される化合物の使用量は、前記一般式（II）で示されるアニリン類に対し０．９〜１．３倍モル、好ましくは１．０〜１．２倍モルである。
上記ジアゾ液の滴下温度及び反応温度は、−１０〜３０℃、好ましくは−５〜１０℃であり、反応時間は０．５〜１０時間、好ましくは１〜５時間である。
カップリング反応液にアルカリ水溶液、例えば、酢酸ナトリウム、酢酸カリウム、水酸化ナトリウム、水酸化カリウム等の水溶液を加え、析出物を濾取、水洗、乾燥し、下記一般式（ＩＶ）

(Wherein R ₁ , R ₂ and R ₃ are the same as defined above) and a coupling reaction is carried out.
The coupling reaction is usually performed in an aqueous solvent under acidic conditions. For example, it is carried out by dissolving or dispersing the compound represented by the general formula (III) in an aqueous solvent such as sulfuric acid, phosphoric acid, hydrochloric acid, acetic acid, propionic acid or a mixture of these acids and mixing the diazo solution. Is done.
The amount of the compound represented by the general formula (III) used is 0.9 to 1.3 times mol, preferably 1.0 to 1.2 times mol for the anilines represented by the general formula (II). is there.
The dropping temperature and reaction temperature of the diazo liquid are −10 to 30 ° C., preferably −5 to 10 ° C., and the reaction time is 0.5 to 10 hours, preferably 1 to 5 hours.
An alkaline aqueous solution, for example, an aqueous solution of sodium acetate, potassium acetate, sodium hydroxide, potassium hydroxide, or the like is added to the coupling reaction solution, and the precipitate is collected by filtration, washed with water, dried, and the following general formula (IV)

（式中、Ｒ_１、Ｒ_２、Ｒ_３、Ｘは前記定義に同じ）で示されるアゾ化合物を得る。
最後に、上記一般式（ＩＶ）のアゾ化合物の臭素原子をシアノ化することにより、目的とする一般式（Ｉ）のアゾ化合物を得ることができる。このシアノ化反応は、極性溶媒中、シアン化銅（Ｉ）を反応させて行う。

(Wherein R ₁ , R ₂ , R ₃ and X are the same as defined above).
Finally, the intended azo compound of the general formula (I) can be obtained by cyanating the bromine atom of the azo compound of the general formula (IV). This cyanation reaction is performed by reacting copper (I) cyanide in a polar solvent.

As the polar solvent, dimethylformamide, dimethyl sulfoxide, dimethylacetamide, N-methylpyrrolidone, sulfolane and the like can be used.
The amount of copper (I) cyanide used is 2.0 to 2.5 times the mole of the azo compound represented by the general formula (IV), and the reaction temperature is 50 to 150 ° C., preferably 70 to 90. The reaction time is 1 to 5 hours.
The cyanation reaction solution is discharged into water, and the precipitate is collected by filtration, washed with water, extracted with an organic solvent such as toluene, and the extract is filtered to remove the metal component, and the organic layer is concentrated to give n-heptane. The desired novel azo compound represented by the general formula (I) is obtained by subjecting it to a dispersion treatment with an aliphatic hydrocarbon such as
Specific examples of the novel azo compound represented by the general formula (I) of the present invention are shown in Table 1. These specific examples do not limit the scope of the present invention.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Example 1]
(Synthesis of Compound of Specific Example No. 10)
4-Chloro-2,6-dibromoaniline (28.5 g, 0.1 mol) was dissolved in 98% sulfuric acid (110 g) and cooled to 5 ° C or lower. Diazotization was performed by dropping 33.4 g (0.105 mol) of 40% nitrosylsulfuric acid at 0 to 5 ° C. and reacting for 1 hour. On the other hand, after dissolving 41.6 g (0.11 mol) of 3- [N, N-bis (isobutyryloxyethyl) amino] acetanilide in 50 g of acetic acid, 200 g of water was added and the solution was cooled to 5 ° C. or lower. After adding the diazotized solution dropwise, the reaction was carried out at 0-5 ° C. for 2 hours. 400 g of 15% aqueous sodium acetate solution was added to the reaction solution, and the precipitate was filtered, washed with water and dried to give 2- (4-chloro-2,6-dibromophenylazo) -5- [N, N-bis (isobutyrate). 55.2 g of (ryloxyethyl) amino] acetanilide were obtained.
Next, 9.6 g (0.12 mol) of copper (I) cyanide was added to 120 g of DMF to 80 ° C., and then 2- (4-chloro-2,6-dibromophenylazo) -5-5 obtained above was used. A solution prepared by dissolving 33.7 g (0.05 mol) of [N, N-bis (isobutyryloxyethyl) amino] acetanilide in 220 g of DMF was added dropwise and reacted at the same temperature for 1 hour. The reaction solution was discharged into 2 kg of water, 23.8 g (0.12 mol) of ferrous chloride / tetrahydrate was added, and the mixture was stirred at 70 ° C. for 1 hour, and then the precipitate was filtered and washed with water to obtain a crude product. . The crude product was extracted with 1.1 kg of toluene and filtered to remove the metal, and then washed with water until neutrality. After concentrating the toluene layer, 600 g of n-heptane was added, and the precipitated crystals were filtered, washed with n-heptane and dried to give 2- (4-chloro-2,6-dicyanophenylazo) -5- [N, 24.1 g of N-bis (isobutyryloxyethyl) amino] acetanilide (the compound of the specific example number 10) was obtained.

The analysis results of this azo compound are shown below.
MS (m / z): 566 (M ⁺ )
Elemental analysis _{(C 28 H 31 ClN 6 O} 5)
C H N
Actual value (%) 59.31 5.51 14.82
Theoretical value (%) 59.26 5.55 14.77
Melting point: 139-140 ° C
Λmax of this azo compound in an acetone solution was 536 nm.
The FT-IR (ATR) spectrum is shown in FIG.

[Example 2]
(Synthesis of Compound of Specific Example No. 11)
Example 1 except that 33.0 g (0.1 mol) of 2,4,6-tribromoaniline was used instead of 28.5 g (0.1 mol) of 4-chloro-2,6-dibromoaniline of Example 1. 2- (4-Bromo-2,6-dicyanophenylazo) -5- [N, N-bis (isobutyryloxyethyl) amino] acetanilide (compound of specific example No. 11) 26.5 g was obtained.

The analysis results of this azo compound are shown below.
MS (m / z): 610 (M ⁺ )
Elemental analysis _{(C 28 H 31 BrN 6 O} 5)
C H N
Actual value (%) 55.00 5.11 13.74
Theoretical value (%) 54.91 5.15 13.79
Melting point: 141-142 ° C
Λmax in an acetone solution of this azo compound was 536.5 nm.
The FT-IR (ATR) spectrum is shown in FIG.

[Example 3]
(Synthesis of Compound of Specific Example No. 14)
3- [N, N-bis (isobutyryloxyethyl) amino] in place of 41.6 g (0.11 mol) of 3- [N, N-bis (isobutyryloxyethyl) amino] acetanilide of Example 1 2- (4-Chloro-2,6-dicyanophenylazo) -5- [N, N was prepared in the same manner as in Example 1 except that 44.7 g (0.11 mol) of isobutyrylanilide was used. -Bis (isobutyryloxyethyl) amino] isobutyrylanilide (the compound of the specific example number 14) 24.9g was obtained.

The analysis results of this azo compound are shown below.
MS (m / z): 594 (M ⁺ )
Elemental analysis _{(C 30 H 35 ClN 6 O} 5)
C H N
Actual value (%) 60.55 5.93 14.12
Theoretical value (%) 60.64 5.90 14.04
Melting point: 159-160 ° C
Λmax of this azo compound in an acetone solution was 534 nm.
The FT-IR (ATR) spectrum is shown in FIG.

[Example 4]
(Synthesis of the compound of the specific example No. 37)
3- [N, N-bis (2-methylpentanoyloxyethyl) instead of 41.6 g (0.11 mol) of 3- [N, N-bis (isobutyryloxyethyl) amino] acetanilide of Example 1 2- (4-Chloro-2,6-dicyanophenylazo) -5- [N, N-bis] was prepared in the same manner as in Example 1 except that 47.8 g (0.11 mol) of amino] acetanilide was used. 24.9 g of (2-methylpentanoyloxyethyl) amino] acetanilide (compound of specific example number 37) was obtained.

The analysis results of this azo compound are shown below.
MS (m / z): 622 (M ⁺ )
Elemental analysis _{(C 32 H 39 ClN 6 O} 5)
C H N
Actual value (%) 61.68 6.31 13.49
Theoretical value (%) 61.61 6.35 13.52
Λmax of this azo compound in an acetone solution was 537 nm.

[Comparative Compound 1]
4-Chloro-2,6-dibromoaniline (28.5 g, 0.1 mol) was dissolved in 98% sulfuric acid (110 g) and cooled to 5 ° C or lower. Diazotization was performed by dropping 33.4 g (0.105 mol) of 40% nitrosylsulfuric acid at 0 to 5 ° C. and reacting for 1 hour. On the other hand, after 35.5 g (0.11 mol) of 3- [N, N-bis (acetoxyethyl) amino] acetanilide was dissolved in 50 g of acetic acid, 200 g of water was added and the solution was cooled to 5 ° C. or lower to the above diazotization solution. Was added at 0-5 ° C. for 2 hours. 400 g of 15% aqueous sodium acetate solution was added to the reaction solution, and the precipitate was filtered, washed with water and dried to give 2- (4-chloro-2,6-dibromophenylazo) -5- [N, N-bis (acetoxyethyl). ) Amino] acetanilide 48.9 g was obtained.
Next, 9.6 g (0.12 mol) of copper (I) cyanide was added to 120 g of DMF to 80 ° C., and then 2- (4-chloro-2,6-dibromophenylazo) -5-5 obtained above was used. A solution prepared by dissolving 30.9 g (0.05 mol) of [N, N-bis (acetoxyethyl) amino] acetanilide in 220 g of DMF was added dropwise and reacted at the same temperature for 1 hour. The reaction solution was discharged into 2 kg of water, 23.8 g (0.12 mol) of ferrous chloride / tetrahydrate was added and stirred at 70 ° C. for 1 hour, and then the precipitate was filtered and washed with water to obtain a crude product. . The crude product was extracted with 1.1 kg of toluene and filtered to remove the metal, and then washed with water until neutrality. After concentrating the toluene layer, 600 g of n-heptane was added, and the precipitated crystals were filtered, washed with n-heptane and dried to give 2- (4-chloro-2,6-dicyanophenylazo) -5- [N, 20.9 g of N-bis (acetoxyethyl) amino] acetanilide (previously known compound (A)) was obtained.

この化合物のアセトン溶液におけるλｍａｘは、５３２ｎｍであった。

Λmax of this compound in an acetone solution was 532 nm.

[Comparative Compound 2]
A compound of the following structural formula (previously known compound (B)) synthesized by the procedure of Example 17 of JP-A-5-212978, page 9.

この化合物のアセトン溶液におけるλｍａｘは、５１８ｎｍであった。

Λmax of this compound in an acetone solution was 518 nm.

[Comparative Compound 3]
A compound having the following structural formula (previously known compound (C)) synthesized by the method described in Journal fuel Praktische Chemie (Leipzig) (1986), 328 (4), 497-514.

この化合物のアセトン溶液におけるλｍａｘは、５３５ｎｍであった。

Λmax of this compound in an acetone solution was 535 nm.

[Solubility measurement]
The solubility of each azo compound synthesized in Examples 1 to 4 and Comparative Compounds 1 to 3 in toluene, methyl ethyl ketone (MEK), toluene: MEK (= 1: 1) mixed solvent and ethyl lactate was measured by the following method.
2 w / v%, 5 w / v% and 10 w / v% dispersions of each compound and each solvent were prepared in a 50 ml screw tube and stirred for 12 hours with a mix rotor. Then, the presence or absence of the residue of dissolution was judged visually and the solubility was determined. The results are shown in Table 2.

[Color tone and light resistance test]
A colored film of each azo compound synthesized in Examples 1 to 4 and Comparative compounds 1 to 3 was prepared by the following method.
Each compound was dissolved in a toluene: MEK (= 1: 1) mixed solvent so as to have a concentration of 1000 ppm to obtain a dyed diluent for an acrylic adhesive. Acrylic pressure-sensitive adhesive and pigmented diluent were mixed at 80: 20% by weight, and coated on a polyethylene terephthalate film [manufactured by Teijin Limited, thickness 75 μm] with a batch type die coater, and dried to prepare a colored film. . Table 2 shows the color tone of each colored film.
Each prepared colored film was irradiated for 24 hours using a xenon fade meter (manufactured by Suga Test Instruments Co., Ltd.), and the light resistance was compared by the following method.
The transmission spectrum before irradiation with the xenon lamp and the transmission spectrum after irradiation were measured using a self-recording spectrophotometer (U-3500 type: manufactured by Hitachi, Ltd.). The light transmittance was calculated by the following formula.

Light resistance (%) = (100−transmittance after irradiation / 100−transmittance before irradiation) × 100

The results are shown in Table 2.

  As is apparent from Table 2, the product of the present invention exhibits high solubility in toluene, MEK, toluene: MEK (= 1: 1) mixed solvent and ethyl lactate. Furthermore, the product of the present invention has a bright magenta color and exhibits high light resistance.

  The novel azo compound of the present invention has a clear magenta color and has good solubility in organic solvents such as aromatic solvents such as toluene, ketone solvents such as methyl ethyl ketone, and ester solvents such as ethyl lactate. And has excellent compatibility with resins and high light fastness, it can be suitably used as a colorant for liquid crystal materials and polymer materials, particularly color filters.

2 is an FT-IR (ATR) spectrum of the azo compound synthesized in Example 1 (the compound of the specific example number 10). 2 is an FT-IR (ATR) spectrum of the azo compound synthesized in Example 2 (the compound of the specific example No. 11). 3 is an FT-IR (ATR) spectrum of the azo compound synthesized in Example 3 (the compound of the specific example number 14).

Claims (3)

An azo compound represented by the following general formula (I).

(In the formula, R ₁ and R ₂ each independently represent an alkyl group having 2 to 8 carbon atoms, R ₃ represents an alkyl group having 1 to 5 carbon atoms , and X represents a chlorine atom or a bromine atom .) The azo compound according to claim ₁ , wherein R ₁ and R ₂ are branched alkyl groups having 3 to 5 carbon atoms, and R ₃ is a linear or branched alkyl group having 1 to 3 carbon atoms. A magenta dye for polymer coloring comprising the azo compound according to claim 1.

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