JP5172229B2 - Azo compound or salt thereof - Google Patents

Description

  The present invention relates to an azo compound useful as a dye or a salt thereof.

Conventionally, dyes such as azo compounds have been used in various fields (for example, fiber materials, liquid crystal display devices, etc.) for color display using reflected light or transmitted light, and have, for example, a barbituric acid skeleton. Azo compounds are also known (Patent Document 1, etc.). More specifically, Patent Document 1 discloses a dye in which two benzenesulfonic acids and one barbituric acid are linked by two azo groups. However, this Patent Document 1 only shows λmax for the color characteristics of the dye, and does not describe any further characteristics.
European Patent Application No. 0163113

  In recent years, demands from customers have become strict regarding the color density and hue of dyed products, and in particular, a new azo compound or a salt thereof having a high color density and excellent vividness (saturation) has been demanded. Accordingly, an object of the present invention is to provide a novel azo compound or a salt thereof excellent in color density and saturation.

  As a result of intensive studies by the present inventors to further improve the color density and saturation of an azo compound or a salt thereof, barbituric acid (including thiobarbituric acid) is present at both ends of the biphenyl skeleton (biphenylene group) via an azo group. It has been found that linked compounds or salts thereof exhibit high color density and excellent saturation. From such knowledge, the azo compound of the present invention or a salt thereof that can achieve the above-mentioned object is represented by the formula (I). The azo compound represented by the formula (I) or a salt thereof may be abbreviated as “azo compound (I)” below. Similarly, a compound represented by another chemical formula or a salt thereof may be abbreviated.

In formula (I), Z ¹ and Z ² each independently represents an oxygen atom or a sulfur atom.
R ¹ to R ⁴ are each independently a hydrogen atom, C _1-10 saturated aliphatic hydrocarbon group, C _1-10 saturated aliphatic hydrocarbon radical hydroxyl group is substituted, C _1-8 alkoxyl group There substituted to have a C _1-10 saturated aliphatic hydrocarbon group, C _1-8 thioalkoxy group substituted to have a C _1-10 saturated aliphatic hydrocarbon group, an aryl group having a carbon number of 6 to 20, carbon It represents an aralkyl group having 7 to 20 carbon atoms or an acyl group having 2 to 10 carbon atoms.
R ^{5 to} R ¹² are each independently a hydrogen atom, halogen atom, C _1-10 saturated aliphatic hydrocarbon group, halogenated C _1-10 saturated aliphatic hydrocarbon group, C _1-8 alkoxyl group, carboxyl Represents a group, a sulfo group, a sulfamoyl group or an N-substituted sulfamoyl group.
In the present invention, C _ab means that the carbon number is a or more and b or less.

In formula (I), preferably at least one of R ^{5 to} R ¹² is an N-substituted sulfamoyl group. More preferably, at least one of R ^{5 to} R ⁸ and at least one of R ^{9 to} R ¹² are N-substituted sulfamoyl groups, and the N-substituted sulfamoyl groups are all carbon atoms meta to the azo group. More preferably, it is bonded to. As the N-substituted sulfamoyl group, —SO ₂ NHR ¹³ group (R ¹³ is a C _1-10 saturated aliphatic hydrocarbon substituted with a C _1-10 saturated aliphatic hydrocarbon group or a C _1-8 alkoxyl group) Group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 2 to 10 carbon atoms) is preferable. By having an N-substituted sulfamoyl group, preferably a —SO ₂ NHR ¹³ group, the azo compound of the present invention or a salt thereof can have both water solubility and oil solubility. In order to further improve the oil solubility, in formula (I), it is preferable that at least one of the carbon atoms of R ¹ to R ⁴ is 6 or more, at least one of R ¹ to R ^4,. 6 to carbon atoms More preferably, it is 20 aryl groups.
The azo compound or salt thereof of the present invention includes tautomers thereof in addition to those represented by the formula (I).

  The azo compound or a salt thereof of the present invention exhibits a high color density and excellent saturation, and is useful as a pigment used in, for example, fiber materials and liquid crystal display devices.

The azo compound of the present invention or a salt thereof, as represented by the formula (I), has barbituric acid (Z (ie, Z ¹ , Z ² ) ═O) and / or thiobarbituric acid (Z (ie, It has a skeleton having a structure of Z ¹ , Z ² ) = S) at both ends of the biphenyl skeleton. The barbituric acid and thiobarbituric acid moieties include the enol type as well as the keto type represented by the formula (I). Due to such a structure, the azo compound of the present invention or a salt thereof exhibits high color density and excellent saturation. Moreover, the azo compound or its salt of this invention is excellent in the solubility (especially oil solubility) to a solvent in the preferable aspect, and is very suitable also for the color display using transmitted light. The solvent has low volatility such as hydroxycarboxylic acid esters (such as ethyl lactate), hydroxyketones (such as diacetone alcohol), ethers (such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate). A water-soluble solvent is selected.

Hereinafter, the formula (I) will be described in detail. In formula (I), Z ¹ and Z ² each independently represents an oxygen atom or a sulfur atom. Z ¹ and Z ² may be the same or different, but are preferably the same.

In formula (I), R ^{1 to} R ⁴ are each independently a hydrogen atom, a C _1-10 saturated aliphatic hydrocarbon group (this C _1-10 saturated aliphatic hydrocarbon group is a hydroxyl group, C _{1 -8} thioalkoxyl groups and the like), an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 2 to 10 carbon atoms.

The saturated aliphatic hydrocarbon group for R ^{1 to} R ⁴ may be linear, branched or cyclic. The carbon number of the saturated aliphatic hydrocarbon group does not include the carbon number of the substituent. The carbon number is 1-10 normally, Preferably it is 2-8, More preferably, it is 3-6. Examples of the saturated aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, ethylhexyl group (2-ethylhexyl group). And the like, and the like, include a cyclopentyl group, a cyclohexyl group, a cyclohexylalkyl group, and the like. The saturated aliphatic hydrocarbon group includes, as described above, a hydroxyl group, a C _1-8 (preferably C _1-4 ) alkoxyl group, a C _1-8 (preferably C _1-4 ) thioalkoxyl group, and the like. The substituent may be substituted. Examples of the substituted saturated aliphatic hydrocarbon group include a hydroxyethyl group (such as 2-hydroxyethyl group), an ethoxyethyl group (such as 2-ethoxyethyl group), and an ethylhexyloxypropyl group (3- (2-ethylhexyloxy)). Propyl group and the like) and methylthiopropyl group (3-methylthiopropyl group and the like).

The aryl group of R ^{1 to} R ⁴ may be unsubstituted or may have a substituent such as a saturated aliphatic hydrocarbon group, an alkoxyl group, a carboxyl group, a sulfo group, or an ester group. The carbon number of the aryl group is counted including the carbon number of the substituent, and is usually 6 to 20, preferably 6 to 10. Examples of these aryl groups include phenyl group, 2-, 3-, 4-methylphenyl group, 2-, 3-, 4-methoxyphenyl group, 2-, 3-, 4-sulfophenyl group, and ethoxycarbonylphenyl. Examples thereof include substituted or unsubstituted phenyl groups such as a group (such as 4- (COOC ₂ H ₅ ) Ph group).

The alkyl part of the aralkyl group (arylalkyl group) of R ^{1 to} R ⁴ may be either linear or branched. The carbon number of the aralkyl group is counted including the carbon number of the substituent, and is usually 7 to 20, preferably 7 to 10. This aralkyl is typically a phenylalkyl group such as a benzyl group.

The acyl group of R ^{1 to} R ⁴ may be unsubstituted, or a substituent such as a saturated aliphatic hydrocarbon group or an alkoxyl group may be bonded thereto. Carbon number of an acyl group is counted including carbon number of a substituent, and the number is 2-10 normally, Preferably it is 6-10. Examples of the acyl group include an acetyl group, a benzoyl group, and a methoxybenzoyl group (such as a p-methoxybenzoyl group).

In order to further increase the color density, at least one (preferably all) of R ^{1 to} R ⁴ may be a group having 5 or less (preferably 3 or less) carbon atoms (for example, a methyl group or an ethyl group) or hydrogen. It is recommended to select atoms. On the other hand, in order to increase the solubility of the azo compound (I) in the solvent, it is desirable to select a group having 6 or more carbon atoms as at least one (preferably all) of R ^{1 to} R ⁴ , An unsubstituted aryl group (preferably a phenyl group) is desirable.

In formula (I), R ^{5 to} R ¹² are each independently a hydrogen atom, a halogen atom (preferably a fluorine, chlorine or bromine atom), a C _1-10 saturated aliphatic hydrocarbon group (this C _1-10 A halogen atom bonded to a saturated aliphatic hydrocarbon group), a C _1-8 alkoxyl group, a carboxyl group, a sulfo group, a sulfamoyl group or an N-substituted sulfamoyl group.

As in the case of R ^{1 to} R ⁴ , the saturated aliphatic hydrocarbon group for R ^{5 to} R ¹² may be linear, branched or cyclic, and the carbon number is usually 1 to 10, preferably Is 2-8, more preferably 3-6. Specific examples of the saturated aliphatic hydrocarbon group for R ^{5 to} R ¹² are the same as those for R ^{1 to} R ⁴ . The saturated aliphatic hydrocarbon group of R ^{5 to} R ¹² may be substituted with a halogen atom, preferably a fluorine atom. Specific examples of the halogenated saturated aliphatic hydrocarbon group include a trifluoromethyl group.

Carbon number of the alkoxyl group of R < ⁵ > -R < ¹² > is 1-8 normally, Preferably it is 1-4. Examples of the alkoxyl group include a methoxy group, an ethoxy group, an isopropoxy group, an n-propoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, and a tert-butoxy group.

The N-substituted sulfamoyl group of R ^{5 to} R ¹² is, for example, an N-monosubstituted sulfamoyl group and can be represented by the formula —SO ₂ NHR ¹³ group. In this formula, R ¹³ represents a C _1-10 saturated aliphatic hydrocarbon group (including a C _1-10 saturated aliphatic hydrocarbon group bonded with a C _1-8 alkoxyl group), and a carbon number of 6 to A 20 aryl group, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 2 to 10 carbon atoms.

The saturated aliphatic hydrocarbon group for R ¹³ may be linear, branched or cyclic. The carbon number of the saturated aliphatic hydrocarbon group does not include the carbon number of the substituent, and the number is usually 1 to 10, preferably 6 to 10. Examples of the saturated aliphatic hydrocarbon group represented by R ¹³ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, methylbutyl group (1 , 1,3,3-tetramethylbutyl group), methylhexyl group (1-methylhexyl group, 1,5-dimethylhexyl group etc.), ethylhexyl group (2-ethylhexyl group etc.), cyclopentyl group, cyclohexyl group, A methylcyclohexyl group (such as a 2-methylcyclohexyl group) and a cyclohexylalkyl group are included. The saturated aliphatic hydrocarbon group for R ¹³ may be substituted with a substituent such as a C _1-8 (preferably C _1-4 ) alkoxyl group as described above. Examples of the substituted saturated aliphatic hydrocarbon group include a propoxypropyl group (3- (isopropoxy) propyl group and the like).

The aryl group of R ¹³ may be unsubstituted or may have a substituent such as a saturated aliphatic hydrocarbon group or a hydroxyl group. The carbon number of the aryl group is counted including the carbon number of the substituent, and is usually 6 to 20, preferably 6 to 10. Examples of these aryl groups include substituted or unsubstituted phenyl groups such as phenyl group, hydroxyphenyl group (such as 4-hydroxyphenyl group), and trifluoromethylphenyl group (such as 4-trifluoromethylphenyl group). .

The alkyl part of the aralkyl group for R ¹³ may be either linear or branched. The carbon number of the aralkyl group is usually 7 to 20, preferably 7 to 10. Typical examples of the aralkyl group include phenylalkyl groups such as benzyl group, phenylpropyl group (such as 1-methyl-3-phenylpropyl group), and phenylbutyl group (such as 3-amino-1-phenylbutyl group). .

The acyl group of R ¹³ may be unsubstituted or may be bonded to a substituent such as a saturated aliphatic hydrocarbon group or an alkoxyl group. Carbon number of an acyl group is counted including carbon number of a substituent, and the number is 2-10 normally, Preferably it is 6-10. Examples of the acyl group include an acetyl group, a benzoyl group, and a methoxybenzoyl group (such as a p-methoxybenzoyl group).

R ^{5 to} R ¹² may be further limited from the viewpoint of enhancing color density, water solubility, oil solubility, light resistance, and the like. For example, from the viewpoint of enhancing the color density and water solubility, one or more of R ^{5 to} R ¹² (for example, one or more from R ^{5 to} R ⁸ (especially one) and from R ^{9 to} R ¹² It is recommended that one or more (particularly one) be a sulfo group and the remaining R ^{5 to} R ¹² be a hydrogen atom or a sulfo group. By increasing the water solubility, it can be widely used as a pigment in the clothing field. As a coloring matter in the clothing field, one type of azo compound (I) may be used alone, or two or more types may be used in combination.

From the viewpoint of enhancing color density and oil solubility, one or more of R ^{5 to} R ¹² (for example, one or more (especially one) from R ^{5 to} R ⁸ ) and one from R ^{9 to} R ^12. For the above (especially one), it is recommended to employ a trifluoromethyl group or an N-substituted sulfamoyl group. In particular, the azo compound (I) in which one of R ^{5 to} R ¹² is an N-substituted sulfamoyl group exhibits high oil solubility even when the remaining one of R ^{5 to} R ¹² is a hydrophilic sulfo group. Show. By increasing the oil solubility, usefulness as a pigment in the field of liquid crystal display devices is increased. As a pigment in the field of liquid crystal display devices, one kind of azo compound (I) may be used alone, or two or more kinds may be used in combination.

When two or more azo compounds (I) are used in combination, the amount dissolved in an organic solvent (oil solubility) is greater than when one of them is used alone. Therefore, from the viewpoint of oil solubility, it is also a preferred embodiment to use a combination of two or more kinds of azo compounds (I) as the dye of the liquid crystal display device. As an example of a combination with improved oil solubility, an azo compound having two N-substituted sulfamoyl groups (disulfonamide) and an azo compound having one N-substituted sulfamoyl group and one sulfo group (monosulfonamide) Combinations are mentioned. Among such combinations, one of R ^{5 to} R ⁸ and one of R ^{9 to} R ¹² is an N-substituted sulfamoyl group, and the remainder is a hydrogen atom, and R ^{5 to} R A combination with a monosulfonamide in which one of ⁸ is an N-substituted sulfamoyl group, one of R ^{9 to} R ¹² is a sulfo group, and the remainder is a hydrogen atom is preferred.

From the viewpoint of enhancing oil solubility, one or more of R ^{5 to} R ¹² (for example, one or more (especially one) from R ^{5 to} R ⁸ and one or more from R ^{9 to} R ¹² (particularly, particularly) 1))) or a relatively bulky group from the above examples, or one or more of R ^{5 to} R ¹² (eg, one or more (especially one) from R ^{5 to} R ⁸ ), It is recommended that one or more (especially one) of R ^{9 to} R ^{12 be in} a meta position or an ortho position with respect to the azo group. By selecting a bulky group or setting the substitution position to the meta position with respect to the azo group, stacking of the biphenyl moiety can be reduced and oil solubility can be increased. Moreover, the azo group can be protected and the light resistance can be improved by selecting a bulky group or by making the substitution position ortho to the azo group. Examples of the bulky R ^{5 to} R ¹² include two or more (particularly 3) such as a branched saturated aliphatic hydrocarbon group such as a tert-butyl group (particularly a tertiary saturated aliphatic hydrocarbon group) and a trifluoromethyl group. And a saturated aliphatic hydrocarbon group to which a halogen atom is bonded) or an N-substituted sulfamoyl group.

Further, R ¹³ of the N-monosubstituted sulfamoyl group may be further limited from the viewpoint of further increasing the color density, oil solubility, and the like. Examples of such R ¹³ include a methylbutyl group (such as 1,1,3,3-tetramethylbutyl group), a methylhexyl group (such as 1,5-dimethylhexyl group), and an ethylhexyl group (2 A branched saturated aliphatic hydrocarbon group such as a methylcyclohexyl group (such as a 2-methylcyclohexyl group), a phenylbutyl group (such as a 3-amino-1-phenylbutyl group), or an aralkyl group. It is done.

Particularly preferred azo compounds (I) are one or more of R ^{5 to} R ¹² , preferably 2 or more (for example, one to one or more (especially one) from R ^{5 to} R ⁸ ), and R ^{9 to} R ¹² to 1 One or more (especially one) is an N-substituted sulfamoyl group.

Among the azo compounds (I) of the present invention having an N-substituted sulfamoyl group, as represented by the formula (II), at least one of R ^{5 to} R ⁸ and at least one of R ^{9 to} R ¹² are A compound having a —SO ₂ NHR ¹³ group and the remainder being a hydrogen atom is preferred.

  Preferred examples of formula (I) include formulas (I-1) to (I-13).

  Preferred examples of formula (II) are formulas (II-1) to (II-7).

The present invention includes not only the compound represented by formula (I) but also a salt thereof. Examples of the salt include a sulfonate when R ^{5 to} R ¹² are sulfo groups, and a carboxylate when R ^{5 to} R ¹² are carboxyl groups. The cations forming these salts are not particularly limited, but considering solubility in solvents, alkali metal salts such as lithium salts, sodium salts and potassium salts; ammonium salts; and ethanolamine salts and alkylamine salts. Organic amine salts and the like are preferred. In particular, an alkali metal salt (preferably a sodium salt) is useful when contained in a polarizing film substrate. In addition, the organic amine salt is useful when it is contained in a resin curable compound. Furthermore, since it is a non-metallic salt, it is also useful in fields where insulation is important.

The azo compound of the present invention can be produced by coupling a diazonium salt with barbituric acid or thiobarbituric acid (hereinafter referred to as “(thio) barbituric acid”), as is well known in the field of dyes. . For example, a compound of formula (b) obtained by diazotizing a benzidine compound (diazo component) represented by formula (a) with nitrous acid, nitrite or nitrite can be used as the diazonium salt (formula In (a) and (b), R ^{5 to} R ¹² represent the same meaning as described above.

The diazonium salt (b) and the (thio) barbituric acid (coupling component) represented by the formula (c) are usually reacted in an aqueous solvent at 20 to 60 ° C. to thereby convert the azo compound (I). (In formula (c), Z ³ represents an oxygen atom or a sulfur atom, and R ¹⁴ and R ¹⁵ represent the same as R ^{1 to} R ⁴ described above). By using both barbituric acid and thiobarbituric acid as coupling components (Z ³ = O and S), azo compounds in which Z ¹ and Z ² are different may be produced, and only one of (thio) barbituric acid (Z ³ ═O or S) may be used to produce an azo compound in which Z ¹ and Z ² are the same, but it is preferable to use only one of (thio) barbituric acid.

The target compound in which at least one of R ^{5 to} R ¹² in the formula (I) is a sulfamoyl group or an N-substituted sulfamoyl group can also be produced by using the compound (a) having a sulfamoyl group or an N-substituted sulfamoyl group. After the coupling reaction using the compound (a) having a sulfo group, it is sure to produce by sulfonamidation. For example, a compound in which at least one of R ^{5 to} R ¹² in formula (I) is a sulfo group (hereinafter referred to as “azosulfonic acid (I)”) is synthesized, and a sulfo group (—SO ₃ H) is obtained by using a thionyl halide compound. ) Can be converted to a sulfohalide (—SO ₂ X; X is a halogen atom) and then reacted with an amine to sulfonamidize the sulfo group.

  Preferred examples of the azosulfonic acid (I) include the formulas (I-1) and (I-3) to (I-13), particularly the formulas (I-1), (I-3), (I- 4), (I-5), and (I-7). Examples of the thionyl halide compound include thionyl fluoride, thionyl chloride, thionyl bromide, thionyl iodide and the like, preferably thionyl chloride, thionyl bromide and the like, particularly thionyl chloride. The amount of thionyl halide used is, for example, about 1 to 10 moles with respect to 1 mole of azosulfonic acid (I). When water is brought into the reaction system, it is preferable to use an excessive amount of the thionyl halide compound.

  The sulfonation is usually performed in a solvent. Examples of the solvent include ethers such as 1,4-dioxane (particularly cyclic ethers); chloroform, methylene chloride, carbon tetrachloride, 1,2-dichloroethane, dichloroethylene, trichloroethylene, perchloroethylene, dichloropropane, and amyl chloride. Halogenated hydrocarbons such as 1,2-dibromoethane can be used. The amount of the solvent used is, for example, about 3 parts by mass (preferably 5 parts by mass or more) and 10 parts by mass or less (preferably 8 parts by mass or less) with respect to 1 part by mass of the azo compound (I).

  In sulfonation, it is recommended to use N, N-dialkylformamide (for example, N, N-dimethylformamide, N, N-diethylformamide, etc.) in combination. When N, N-dialkylformamide is used, the amount used is, for example, about 0.05 to 1 mol with respect to 1 mol of the thionyl halide. Heat generation can be suppressed by adding thionyl halide after previously mixing azosulfonic acid (I) and N, N-dialkylformamide in a solvent.

  The reaction temperature is, for example, 0 ° C. or higher (preferably 30 ° C. or higher) and 70 ° C. or lower (preferably 60 ° C. or lower). The reaction time is, for example, about 0.5 hours or more (preferably 3 hours or more) and 8 hours or less (preferably 5 hours or less).

  The sulfone halide compound prepared as described above may be isolated and then reacted with the amine, or may be reacted with the amine in the form of a reaction mixture without isolation. In the case of isolation, for example, the reaction mixture and water may be mixed, and the precipitated crystals may be collected by filtration. The obtained sulfone halide compound crystals may be washed with water and dried as necessary before the reaction with the amine.

Examples of the amine include a primary amine, and the primary amine is represented by the formula H ₂ N—R ¹³ (R ¹³ is the same as described above). Specific examples of H ₂ N—R ¹³ include n-propylamine, n-butylamine, n-hexylamine, dimethylhexylamine (such as 1,5-dimethylhexylamine), tetramethylbutylamine (1,1,3,3). 3-tetramethylbutylamine and the like), ethylhexylamine (such as 2-ethylhexylamine), aminophenylbutane (such as 3-amino-1-phenylbutane), and isopropoxypropylamine. The amount of amine used is usually about 3 mol or more and 13 mol or less (preferably 10 mol or less) with respect to 1 mol of the sulfone halide compound. In this specification, in order to distinguish this amine from the basic catalyst described later, hereinafter, it may be referred to as a reactive amine.

  The order of addition of the sulfone halide compound and the amine is not particularly limited, but an amine is often added (dropped) to the sulfone halide compound. The reaction between the sulfone halide compound and the amine is usually performed in a solvent. As the solvent, the same solvent as that used for preparing the sulfone halide compound can be used.

  The reaction between the sulfone halide and the reactive amine is preferably carried out in the presence of a basic catalyst. Examples of the basic catalyst include tertiary amines (particularly aliphatic tertiary amines such as triethylamine and triethanolamine), pyridine bases such as pyridine and methylpyridine, and the like. Among these, tertiary amines, particularly aliphatic tertiary amines such as triethylamine are preferable. The usage-amount of a basic catalyst is about 1.1 mol or more and 3 mol or less (preferably 2 mol or less) normally with respect to a reactive amine (the said amine reacted with a sulfone halide).

  When a reactive amine and a basic catalyst are added to the sulfone halide compound, the timing of adding the basic catalyst is not particularly limited, and may be either before or after the addition of the reactive amine, and is the same as the reactive amine. It may be added at the timing. Further, it may be added after mixing with the reactive amine in advance, or may be added separately from the reactive amine.

  The reaction temperature of the sulfone halide and the reactive amine is, for example, 0 ° C. or higher and 50 ° C. or lower (preferably 30 ° C. or lower). The reaction time is usually about 1 to 5 hours.

  The method for obtaining the target sulfonamide compound from the reaction mixture is not particularly limited, and various known methods can be employed. For example, the reaction mixture is mixed with an acid (acetic acid) and water, and the precipitated crystals are filtered. You may take it. The acid and water are often used after an aqueous acid solution is prepared in advance, and the reaction mixture is often added to the aqueous acid solution. The addition temperature of the reaction mixture is usually 10 ° C. or higher (preferably 20 ° C. or higher) and 50 ° C. or lower (preferably 30 ° C. or lower). Moreover, after addition, it is common to stir at the same temperature for about 0.5 to 2 hours. The crystal collected by filtration is usually washed with water and then dried. Moreover, you may refine | purify further by well-known methods, such as recrystallization, as needed.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, and appropriate modifications are made within a range that can meet the above and the following purposes. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention. In the examples and comparative examples, “%” and “parts” are mass% and mass parts unless otherwise specified.

Example 1
After adding 300 parts of water to 30 parts of 2,2′-benzidinedisulfonic acid (containing 30% water) represented by the formula (a-1), the mixture was adjusted to pH 7-8 with 30% aqueous sodium hydroxide solution under ice cooling. Adjusted. The following operations were performed under ice cooling. 12.6 parts of sodium nitrite was added and stirred for 30 minutes. After adding 38.1 parts of 35% hydrochloric acid little by little to give a brown solution, the mixture was stirred for 2 hours. An aqueous solution in which 5.3 parts of amidosulfuric acid was dissolved in 57.4 parts of water was added to the reaction solution and stirred to obtain a suspension containing a diazonium salt.

  After adding 372 parts of water to 18.6 parts of N, N'-dimethylbarbituric acid represented by the formula (c-1), the pH was adjusted to 8-9 with a 30% aqueous sodium hydroxide solution under ice cooling.

  The following operations were performed under ice cooling. The aqueous barbituric acid aqueous solution was stirred to give a colorless solution, and a suspension containing a diazonium salt was added dropwise with a pump while adjusting the pH to 8 to 9 with a 30% aqueous sodium hydroxide solution. After completion of dropping, the mixture was further stirred for 3 hours to obtain a yellow suspension. The yellow solid obtained by filtration was dried at 60 ° C. under reduced pressure to obtain 14.6 parts of an azo compound represented by the formula (I-1).

The structure of the azo compound (I-1) was determined by ¹ H-NMR and ¹³ C-NMR analysis. As an analytical instrument, ECA-500 (manufactured by JEOL Ltd.) was used.
¹ H-NMR (500 MHz, δ value (ppm, TMS standard), DMSO, room temperature); 3.22 (6H, s), 3.40 (6H, s), 7.33 (4H, d, J = 8 .4 Hz), 7.48 (4H, dd, J = 8.4, 2.3 Hz), 8.13 (2H, d, J = 2.3 Hz), 14.31 (2H, s)
¹³ C-NMR (125 MHz, δ value (ppm, TMS standard), DMSO, room temperature); 27.3, 28.2, 115.3, 116.2, 117.3, 133.8, 135.8, 139 .5, 146.1, 150.6, 158.8, 160.5

0.35 g of the obtained azo compound (I-1) was dissolved in N, N-dimethylformamide to a volume of 250 cm ³ , 2 cm ^{3 of} which was diluted with water to a volume of 100 cm ³ (concentration: 0.00). 028 g / L) and a spectrophotometer (quartz cell, cell length is 1 cm), the absorption spectrum was measured. The obtained absorption spectrum is shown in FIG. This compound exhibited an absorbance of 2.49 (arbitrary unit) at λmax = 409 nm and a full width at half maximum of 68 nm.

Comparative Example 1
After adding 348 parts of water to 23.2 parts of sulfanilic acid represented by the formula (d-1), the pH was adjusted to 7 to 8 with a 30% aqueous sodium hydroxide solution under ice cooling. The following operations were performed under ice cooling. 11.1 parts of sodium nitrite was added and stirred for 30 minutes. After adding 41.9 parts of 35% hydrochloric acid in small portions to make a milky white suspension, the mixture was stirred for 2 hours. An aqueous solution in which 2.5 parts of amidosulfuric acid was dissolved in 25.2 parts of water was added to the reaction solution and stirred to obtain a suspension containing a diazonium salt.

  After adding 372 parts of water to 24.2 parts of N, N'-dimethylbarbituric acid represented by the formula (c-1), the pH was adjusted to 8-9 with a 30% aqueous sodium hydroxide solution under ice cooling. The following operations were performed under ice cooling. The aqueous barbituric acid aqueous solution was stirred to give a colorless solution, and a suspension containing a diazonium salt was added dropwise with a pump while adjusting the pH to 8 to 9 with a 30% aqueous sodium hydroxide solution. After completion of dropping, the mixture was further stirred for 3 hours to obtain a yellow suspension. The yellow solid obtained by filtration was dried at 60 ° C. under reduced pressure to obtain 36.2 parts of an azo compound represented by the formula (III-1).

  The absorption spectrum of the barbituric acid monoazo compound represented by the formula (III-1) was measured under the same conditions as in Example 1. The obtained absorption spectrum is shown in FIG. This compound showed an absorbance of 2.03 (arbitrary unit) at λmax = 387 nm and a full width at half maximum of 63 nm.

  Example 1 (Formula I-1) and Comparative Example 1 (Formula III-1) have the same number of azo groups, phenyl groups, and barbituric acids per gram (number of moles). However, the absorbance (concentration: 0.028 g / L) of Example 1 (Formula I-1) is 0.46 greater than the absorbance of Comparative Example 1 (Formula III-1) at the same concentration. This result shows that the azo compound of the present invention having a barbituric acid structure at both ends or a salt thereof has a high color density.

Comparative Example 2
120 parts of water and 120 parts of N-methylpyrrolidone were added to 20 parts of sodium 4-aminoazobenzene-4′-sulfonate represented by the formula (d-2), and then with a 30% aqueous sodium hydroxide solution under ice cooling. The pH was adjusted to 7-8. The following operations were performed under ice cooling. 9.2 parts of sodium nitrite was added and stirred for 30 minutes. A small amount of 48.7 parts of 35% hydrochloric acid was added to make a milky white suspension, followed by stirring for 2 hours. An aqueous solution in which 6.3 parts of amidosulfuric acid was dissolved in 40 parts of water was added to the reaction solution and stirred to obtain a suspension containing a diazonium salt.

  300 parts of water was added to 12.5 parts of N, N'-dimethylbarbituric acid represented by the formula (c-1), and then adjusted to pH 8-9 with a 30% aqueous sodium hydroxide solution under ice cooling. The following operations were performed under ice cooling. The aqueous barbituric acid aqueous solution was stirred to give a colorless solution, and a suspension containing a diazonium salt was added dropwise with a pump while adjusting the pH to 8 to 9 with a 30% aqueous sodium hydroxide solution. After completion of the dropwise addition, the mixture was further stirred for 3 hours to obtain a yellowish yellow suspension. The yellow-yellow solid obtained by filtration was dried at 60 ° C. under reduced pressure to obtain 26.4 parts of an azo compound represented by the formula (III-2).

  The absorption spectrum of the barbituric acid disazo compound represented by the formula (III-2) was measured under the same conditions as in Example 1. The obtained absorption spectrum is shown in FIG. This compound exhibited an absorbance of 2.75 (arbitrary unit) at λmax = 416 nm and a full width at half maximum of 84 nm.

  As shown in Comparative Example 2 (Formula III-2), as a method for increasing the absorbance of Comparative Example 1 (Formula III-1), there is a method of inserting an azophenylene group. However, in the method of inserting an azophenylene group (Comparative Example 2), the full width at half maximum is too wide and the saturation is too low. In contrast, the azo compound of the present invention or a salt thereof as shown in Example 1 (Formula I-1) can achieve both high color density and excellent saturation.

Example 2
After adding 360 parts of water to 36 parts of 2,2′-benzidinedisulfonic acid (containing 30% water) represented by the formula (a-1), the pH is adjusted to 7-8 with 30% aqueous sodium hydroxide solution under ice cooling. did. The following operations were performed under ice cooling. 25.3 parts of sodium nitrite was added and stirred for 30 minutes. After adding 68.6 parts of 35% hydrochloric acid little by little to make a brown solution, the mixture was stirred for 2 hours. An aqueous solution in which 20.7 parts of amidosulfuric acid was dissolved in 206.6 parts of water was added to the reaction solution and stirred to obtain a suspension containing a diazonium salt.

  After adding 379.8 parts of water to 25.3 parts of thiobarbituric acid represented by the formula (c-2), the mixture was adjusted to pH 8-9 with 30% aqueous sodium hydroxide solution under ice cooling.

  The following operations were performed under ice cooling. The aqueous thiobarbituric acid solution was stirred to give a colorless solution, and a suspension containing a diazonium salt was added dropwise with a pump while adjusting the pH to 8 to 9 with a 30% aqueous sodium hydroxide solution. After completion of dropping, the mixture was further stirred for 3 hours to obtain a yellow suspension. The yellow solid obtained by filtration was dried at 60 ° C. under reduced pressure to obtain 64.8 parts of an azo compound represented by the formula (I-3).

  The absorption spectrum of the azo compound (I-3) was measured under the same conditions as in Example 1. The obtained absorption spectrum is shown in FIG. This compound exhibited an absorbance of 3.41 (arbitrary unit) at λmax = 435 nm and a full width at half maximum of 61 nm. This result shows that the azo compound of the present invention having a thiobarbituric acid structure skeleton at both ends has excellent color density and saturation.

Example 3
After adding 375 parts of water to 25 parts of 2,2′-benzidinedisulfonic acid (containing 30% water) represented by the formula (a-1), the solution was adjusted to pH 7-8 with 30% aqueous sodium hydroxide solution under ice cooling. Adjusted. The following operations were performed under ice cooling. 10.2 parts of sodium nitrite was added and stirred for 30 minutes. After adding 31.8 parts of 35% hydrochloric acid little by little to give a brown solution, the mixture was stirred for 2 hours. An aqueous solution in which 4.8 parts of amidosulfuric acid was dissolved in 47.8 parts of water was added to the reaction solution and stirred to obtain a suspension containing a diazonium salt.

  After adding 295 parts of water and 295 parts of acetone to 29.5 parts of N- (n-butyl) -N ′-(4-methoxyphenyl) barbituric acid represented by the formula (c-3), The pH was adjusted to 10 with a 30% aqueous sodium hydroxide solution.

  The following operations were performed under ice cooling. The aqueous barbituric acid aqueous solution was stirred to give a colorless solution, and a suspension containing a diazonium salt was added dropwise with a pump while adjusting the pH to 10 with a 30% aqueous sodium hydroxide solution under ice cooling. After completion of dropping, the mixture was further stirred for 3 hours to obtain a yellow suspension. The yellow solid obtained by filtration was dried at 60 ° C. under reduced pressure to obtain 23.6 parts (yield 49%) of an azo compound represented by the formula (I-8).

  The absorption spectrum of the azo compound (I-8) was measured under the same conditions as in Example 1. The obtained absorption spectrum is shown in FIG. This compound exhibited an absorbance of 1.88 (arbitrary unit) at λmax = 418 nm and a full width at half maximum of 70 nm.

Example 4
A flask equipped with a condenser and a stirrer is charged with 5 parts of an azo compound (I-1), 50 parts of chloroform and 2.1 parts of N, N-dimethylformamide, and maintained at 20 ° C. or lower with stirring. 6 parts of thionyl was added dropwise. After completion of the dropwise addition, the temperature was raised to 50 ° C., the reaction was continued for 5 hours at the same temperature, and then cooled to 20 ° C. While maintaining the reaction solution after cooling at 20 ° C. or lower with stirring, a mixed solution of 4 parts of n-propylamine and 14 parts of triethylamine was added dropwise. Then, it was made to react by stirring at the same temperature for 5 hours. Next, after the solvent of the obtained reaction mixture was distilled off with a rotary evaporator, a small amount of methanol was added and stirred vigorously. This mixture was added to a mixed solution of 29 parts of acetic acid and 300 parts of ion-exchanged water with stirring to precipitate crystals. The precipitated crystals were separated by filtration, washed well with ion exchange water, and dried under reduced pressure at 60 ° C. to obtain 4.2 parts (yield 75%) of the azo compound represented by the formula (II-2).

  The absorption spectrum of the azo compound (II-2) was measured under the same conditions as in Example 1. The obtained absorption spectrum is shown in FIG. This compound exhibited an absorbance (arbitrary unit) of 2.37 at λmax = 404 nm and a full width at half maximum of 64 nm.

Comparative Example 3
A flask equipped with a condenser and a stirrer is charged with 5 parts of an azo compound (III-1), 50 parts of chloroform and 2.1 parts of N, N-dimethylformamide and maintained at 20 ° C. or lower with stirring. 6 parts of thionyl was added dropwise. After completion of the dropwise addition, the temperature was raised to 50 ° C., the reaction was continued for 5 hours at the same temperature, and then cooled to 20 ° C. While maintaining the reaction solution after cooling at 20 ° C. or lower with stirring, a mixed liquid of 4 parts of 1,1,3,3-tetramethylbutylamine and 14 parts of triethylamine was added dropwise. Then, it was made to react by stirring at the same temperature for 5 hours. Next, after the solvent of the obtained reaction mixture was distilled off with a rotary evaporator, a small amount of methanol was added and stirred vigorously. This mixture was added to a mixed solution of 29 parts of acetic acid and 300 parts of ion-exchanged water with stirring to precipitate crystals. The precipitated crystals were separated by filtration, washed well with ion-exchanged water, and dried under reduced pressure at 60 ° C. to obtain 4.1 parts (yield 62%) of an azo compound represented by the formula (III-3).

  The absorption spectrum of the azo compound represented by the formula (III-3) was measured under the same conditions as in Example 1. The obtained absorption spectrum is shown in FIG. This compound exhibited an absorbance (arbitrary unit) of 2.05 at λmax = 387 nm and a full width at half maximum of 64 nm.

  The absorbance at λmax of Example 4 (Formula II-2) is 0.32 greater than the value of Comparative Example 3 (Formula III-3). This result shows that the azo compound of the present invention has an excellent color density.

Comparative Example 4
A flask equipped with a condenser and a stirrer is charged with 5 parts of an azo compound (III-2), 50 parts of chloroform and 2.1 parts of N, N-dimethylformamide and maintained at 20 ° C. or lower with stirring. 6 parts of thionyl was added dropwise. After completion of the dropwise addition, the temperature was raised to 50 ° C., the reaction was continued for 5 hours at the same temperature, and then cooled to 20 ° C. While maintaining the reaction solution after cooling at 20 ° C. or lower with stirring, a mixed liquid of 4 parts of 1,1,3,3-tetramethylbutylamine and 14 parts of triethylamine was added dropwise. Then, it was made to react by stirring at the same temperature for 5 hours. Next, after the solvent of the obtained reaction mixture was distilled off with a rotary evaporator, a small amount of methanol was added and stirred vigorously. This mixture was added to a mixed solution of 29 parts of acetic acid and 300 parts of ion-exchanged water with stirring to precipitate crystals. The precipitated crystals were separated by filtration, washed well with ion exchange water, and dried under reduced pressure at 60 ° C. to obtain 3.6 parts (yield 58%) of an azo compound represented by the formula (III-4).

  The absorption spectrum of the azo compound represented by the formula (III-4) was measured under the same conditions as in Example 1. The obtained absorption spectrum is shown in FIG. This compound exhibited an absorbance (arbitrary unit) of 2.74 at λmax = 420 nm and a full width at half maximum of 77 nm. In Comparative Example 4 (Formula III-4), the full width at half maximum is too wide and the saturation is poor.

Example 5
Oil of azo compound (I-1) having sulfo group, azo compound (I-8) having 4-methoxyphenyl group as R ^{1 to} R ⁴ , and azo compound (II-1) having N-substituted sulfamoyl group The solubility (solubility in ethyl lactate) was examined.

  The azo compound represented by the formula (II-1) was produced as follows. A flask equipped with a condenser and a stirrer was charged with 10 parts of azo compound (I-1), 100 parts of chloroform and 4.2 parts of N, N-dimethylformamide, and maintained at 20 ° C. or lower with stirring. 7 parts of thionyl was added dropwise. After completion of the dropwise addition, the temperature was raised to 50 ° C., the reaction was continued for 5 hours at the same temperature, and then cooled to 20 ° C. While maintaining the reaction solution after cooling at 20 ° C. or lower with stirring, a mixed solution of 5 parts of 1,5-dimethylhexylamine and 15 parts of triethylamine was added dropwise. Then, it was made to react by stirring at the same temperature for 5 hours. Next, after the solvent of the obtained reaction mixture was distilled off with a rotary evaporator, a small amount of methanol was added and stirred vigorously. This mixture was added to a mixed solution of 58 parts of acetic acid and 600 parts of ion-exchanged water with stirring to precipitate crystals. The precipitated crystals were separated by filtration, washed well with ion-exchanged water, and dried under reduced pressure at 60 ° C. to obtain 10.9 parts (yield 82%) of azo compound (II-1).

The oil solubility of azo compounds (I-1), (I-8) and (II-1) was examined as follows: 1 g of azo compound and 9 g of ethyl lactate were placed in a vial and stirred for a whole day and night. The remaining solid was removed by filtration (if the azo compound was completely dissolved, the filtrate concentration was 10% by weight). The absorption spectrum of the filtrate thus obtained was measured in the same manner as in Example 1 except that 3.5 g of the filtrate was used, and the absorbance (Int (a)) at λmax of each azo compound was determined. . Further, using 0.35 g of each azo compound, the absorbance (Int (r)) at λmax of each azo compound was determined in the same manner as in Example 1. And the following formula:
Solubility (mass%) = (Int (a) × 10) / Int (r)
From this, the solubility of each azo compound was calculated. The results are shown in Table 1.

From the results shown in Table 1, the oil solubility of the azo compound of the present invention is improved by introducing an aryl group into R ^{1 to} R ⁴ or introducing an N-substituted sulfamoyl group into R ^{5 to} R ^12. I understand.

  The azo compound or salt thereof of the present invention exhibits a very high color density. Therefore, even with a small amount of use, a dyed product having the same quality as the conventional one can be obtained from the azo compound of the present invention or a salt thereof, which is advantageous in terms of cost. In addition, when the azo compound of the present invention or a salt thereof is used in a curable resin composition for producing a liquid crystal display component, the amount used is reduced, and thus a component excellent in performance such as solvent resistance and heat resistance is produced. it can. Furthermore, the azo compound or a salt thereof of the present invention exhibits excellent saturation and may be used alone as a dye, or may be used in combination with other dyes as a toning dye. Thus, the azo compound or salt thereof of the present invention showing a high color density and excellent saturation can be used for various purposes other than producing dyed products and liquid crystal display parts.

It is a figure which shows the absorption spectrum of the azo compound (Example 1) represented by a formula (I-1). It is a figure which shows the absorption spectrum of the azo compound (Comparative Example 1) represented by Formula (III-1). It is a figure which shows the absorption spectrum of the azo compound (comparative example 2) represented by Formula (III-2). It is a figure which shows the absorption spectrum of the azo compound (Example 2) represented by a formula (I-3). It is a figure which shows the absorption spectrum of the azo compound (Example 3) represented by Formula (I-8). It is a figure which shows the absorption spectrum of the azo compound (Example 4) represented by Formula (II-2). It is a figure which shows the absorption spectrum of the azo compound (Comparative Example 3) represented by Formula (III-3). It is a figure which shows the absorption spectrum of the azo compound (comparative example 4) represented by Formula (III-4).

Claims (10)

An azo compound represented by the formula (I) or a salt thereof.

[In formula (I), Z < ¹ > and Z < ² > represent an oxygen atom or a sulfur atom each independently.
R ¹ to R ⁴ are each independently a hydrogen atom, C _1-10 saturated aliphatic hydrocarbon group, C _1-10 saturated aliphatic hydrocarbon radical hydroxyl group is substituted, C _1-8 alkoxyl group There substituted to have a C _1-10 saturated aliphatic hydrocarbon group, C _1-8 thioalkoxy group substituted to have a C _1-10 saturated aliphatic hydrocarbon group, an aryl group having a carbon number of 6 to 20, carbon an aralkyl group having 7 to 20, or carbon atoms to display the acyl group having 2 to 10, at least one of the carbon atoms of R ¹ to R ⁴ is 6 or more.
R ^{5 to} R ¹² are each independently a hydrogen atom, halogen atom, C _1-10 saturated aliphatic hydrocarbon group, halogenated C _1-10 saturated aliphatic hydrocarbon group, C _1-8 alkoxyl group, carboxyl Represents a group, a sulfo group, a sulfamoyl group or an N-substituted sulfamoyl group. ] An azo compound represented by the formula (I) or a salt thereof.

[In formula (I), Z ¹ And Z ² Each independently represents an oxygen atom or a sulfur atom.
R ¹ ~ R ^Four Each independently represents a hydrogen atom, C _1-10 C substituted with a saturated aliphatic hydrocarbon group or hydroxyl group _1-10 Saturated aliphatic hydrocarbon group, C _1-8 C substituted with an alkoxyl group _1-10 Saturated aliphatic hydrocarbon group, C _1-8 C substituted with a thioalkoxyl group _1-10 A saturated aliphatic hydrocarbon group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 2 to 10 carbon atoms; ¹ ~ R ^Four At least one of is an aryl group having 6 to 20 carbon atoms.
R ^Five ~ R ¹² Each independently represents a hydrogen atom, a halogen atom, or C _1-10 Saturated aliphatic hydrocarbon group, halogenated C _1-10 Saturated aliphatic hydrocarbon group, C _1-8 Represents an alkoxyl group, a carboxyl group, a sulfo group, a sulfamoyl group or an N-substituted sulfamoyl group; ] At least one of R ⁵ to R ¹² is an azo compound or a salt thereof according to claim 1 or 2 which is N- substituted sulfamoyl group. The azo compound or a salt thereof according to claim 3 , wherein at least one of R ^{5 to} R ⁸ and at least one of R ^{9 to} R ¹² is an N-substituted sulfamoyl group. The azo compound or a salt thereof according to claim 4 , wherein at least one of R ⁵ and R ⁸ and at least one of R ⁹ and R ¹² is an N-substituted sulfamoyl group. The N-substituted sulfamoyl group is a —SO ₂ NHR ¹³ group, and R ¹³ is a C _1-10 saturated aliphatic group substituted with a C _1-10 saturated aliphatic hydrocarbon group or a C _1-8 alkoxyl group. The azo compound according to any one of claims 1 to 5 , which represents a hydrocarbon group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 2 to 10 carbon atoms. Or a salt thereof. An azo compound represented by the formula (I) or a salt thereof.

[In formula (I), Z ¹ And Z ² Each independently represents an oxygen atom or a sulfur atom.
R ¹ ~ R ^Four Each independently represents a hydrogen atom, C _1-10 C substituted with a saturated aliphatic hydrocarbon group or hydroxyl group _1-10 Saturated aliphatic hydrocarbon group, C _1-8 C substituted with an alkoxyl group _1-10 Saturated aliphatic hydrocarbon group, C _1-8 C substituted with a thioalkoxyl group _1-10 A saturated aliphatic hydrocarbon group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 2 to 10 carbon atoms is represented.
R ^Five ~ R ¹² Each independently represents a hydrogen atom, a halogen atom, or C _1-10 Saturated aliphatic hydrocarbon group, halogenated C _1-10 Saturated aliphatic hydrocarbon group, C _1-8 Represents an alkoxyl group, carboxyl group, sulfo group, sulfamoyl group or N-substituted sulfamoyl group, R ^Five ~ R ¹² At least one of is an N-substituted sulfamoyl group. ] R ^Five ~ R ⁸ At least one of R and R ⁹ ~ R ¹² The azo compound or a salt thereof according to claim 7, wherein at least one of is an N-substituted sulfamoyl group. R ^Five And R ⁸ At least one of R and R ⁹ And R ¹² The azo compound or a salt thereof according to claim 8, wherein at least one of is an N-substituted sulfamoyl group. The N-substituted sulfamoyl group is -SO. ₂ NHR ¹³ R and R ¹³ Is C _1-10 Saturated aliphatic hydrocarbon group, C _1-8 C substituted with an alkoxyl group _1-10 The saturated aliphatic hydrocarbon group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 2 to 10 carbon atoms, according to any one of claims 7 to 9. Or an azo compound thereof.