GB2031451A

GB2031451A - Monoazo blue disperse dye

Info

Publication number: GB2031451A
Application number: GB7925381A
Authority: GB
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 1978-07-21
Filing date: 1979-07-20
Publication date: 1980-04-23
Also published as: CH653203GA3; DE2928432A1; FR2431521A1; GB2031451B; FR2431521B1; IN151676B; IT7949825A0

Abstract

A compound of the formula, <IMAGE> in which R<1> is a methyl or ethyl group, R<2> and R<3> are each C5 to C8 alkyl, and Z is a chloro or cyano group, has an excellent stability in a dye bath and an excellent dyeability for dyeing a hydrophobic fiber blue.

Description

SPECIFICATION Monoazo blue disperse dye TECHNICAL FIELD The present invention relates to a novel monoazo disperse dye suitable for dyeing hydrophobic fibers particularly polyester fibers and cellulose ester fibers in a blue color.

PRIOR ART For dyeing of hydrophobic fibers such as polyester fibers and cellulose ester fibers, anthraquinone disperse dyes are used in many cases, irrespective of their low molar absorption coefficient, for the reasons that they are superior in stability in a dye bath, that is, they are low in pH sensitivity and superior in decomposition resistance in a dye bath, and besides that they provide dyed goods of brilliance and high fastnesses. But the anthraquinone disperse dyes are generally of high cost, which is a commercially serious problem.

While azo disperse dyes are generally of low cost and have advantages that molar absorption coefficient is large and the fastnesses of dyed goods are high as compared with the anthraquinone disperse dyes, whereas they have such serious disadvantages in that they are poor in stability in a dye bath and provide dyed goods lacking brilliance.Various azo disperse dyes are disclosed for example in Japanese Patent Publication Nos. 6910/1966 (A) and 16554/1976 (B) and British Patent No. 1,489,016 (C) as shown below:

"This compound is not disclosed explicitly in Japanese Patent Publication No. 16554/1976 but included therein conceptually.

Further, the following commercial azo blue disperse dyes are known: Known compound

Known compound

All the aforesaid azo disperse dyes, however, have the disadvantages as described above.

In order to alleviate the disadvantage that anthraquinone disperse dyes are of high cost, the development of low-cost dyes by mixing anthraquinone disperse dyes and azo ones is tried in the related field. The fact is however that practical low-cost mixed dyes are not yet obtained with ease. In general, mixed dyes of anthraquinone dyes and azo dyes lose brilliance characteristic of the anthraquinone dyes and only provide dyed goods with poor reproducibility because of the decomposition of azo dyes on dyeing.

In order to alleviate these disadvantages, the inventors extensively studied to find azo blue disperse dyes of high commercial value.

An aim of the present invention is to provide a novel azo blue disperse dye excellent in dyeing affinity, stability in a dye bath (low pH sensitivity and superior decomposition resistance), sublimation resistance and light fastness as well as brilliant and deep shade.

Another aim of the present invention is to provide a novel azo blue disperse dye which can provide a mixed dye of high commercial value comprising said azo dye and an anthraquinone blue disperse dye without damaging the characteristics of the anthraquinone dye.

A further aim of the present invention is to provide novel azo blue disperse dyes which achieve the aforesaid objects and besides have a stable, novel crystal form causing no lowering in dispersibility nor aggregation during dyeing.

STATEMENT OF INVENTION AND ADVANTAGES To these ends there is provided according to the invention a novel azo blue disperse dye of the formula (I),

in which R' is a methyl or ethyl group, R2 and R3 are each C5 to C8 alkyl and Z is a chloro or cyano group. Preferably the compound is 2-cyano-4-nitro-6-chloro-21-acetylamino-41.(N, N-di-n- pentyl)-amino-1 , 1 '-azobenzene in a crystal form showing a great relative intensity at each angle of an X-ray powder diffraction (2H;; Cu-Ka) of 14.0 , 18.5 , 21.4 and 25.6 , and a medium relative intensity at the angle of 11.2", 12.6 , 16.0 , 17.6 , 19.2", 23.5', 24.2 and 26.4 .

Further according to the invention there is provided a process for producing the dye of the formula (I), which comprises reacting a diazotized compound of the formula (II),

in which Z is as defined above, with a compound of the formula (III),

in which R', R2 and R3 are as defined above.

Preferably the process for producing the monoazo compound of the above particular preferred crystal form, comprises reacting diazotized 2-cyano-4-nitro-6-chloroaniline with 3-acetylamino-N, N-di-n-pentylaniline to obtain a monoazo compound, 2-cyano-4-nitro-6-chloro-2'-acetylamino-4' (N,N-din-pentyl)amino-1,1'-azobenzene, and then heating the resting monoazo compound in an aqueous medium or an organic solvent, if necessary, in the presence of a surfactant.Still further according to the invention there is provided a dye composition comprising 98 to 5% by weight of an anthraquinone dye of the formula,

in which one of X and Y is an amino group and the other is a hydroxyl group and n is a number satisfying the equation, 06n < 2, or

in which R is hydrogen or lower alkyl, and 2 to 95% by weight of a compound of the formula (I) including the above 2-cyano-4-nitro-6-chloro-2'-acetylam ino-4'-(N, N-di-n-pentyl)amino- 1 , 1 '- azobenzene having the particular crystal form.

In the formula (I), the alkyl represented by R2 and R3 is C5 to C8 straight alkyl, preferably C5 or C6 straight alkyl. Of the compounds of the formula (I), preferred ones are dyes wherein both of R2 and R3 are n-pentyl or n-hexyl, preferably n-pentyl, and Z is chlorine. Preferred dyes are represented by the formula,

in which R1 is as defined above, most preferably methyl.

In producing the compound of the formula (I), the compound of the formula (II) may be

Specific examples of the compound of the formula (III) include the following compounds:

These compounds (III) are obtained by dialkylating 3-acetylaminoaniline or 3-propionylaminoaniline with a corresponding alkyl halide or a corresponding alkyl ester of p-toluenesulfonic acid according to known methods, for example the method disclosed in Japanese Patent Publication No. 3712/1966.

The dyes ofthe formula (I) are obtained as follows: The compound of the formula (II) (diazo component) is diazotized, as it is or after dissolved or suspended in a mineral acid (e.g. sulfuric acid, hydrochloric acid) or organic acid (e.g. acetic acid, propionic acid), with nitrosylsulfuric acid at a low temperature, preferably at about 10 to about'l5"C for about 5 hou;s; the compound of the formula (III) (coupling component) is dissolved in a mineral acid (e.g.

hydrochloric acid, sulfuric acid), organic acid (e.g. acetic acid, propionic acid) or organic solvent (e.g. methanol, ethanol), the diazo component obtained above is added thereto preferably at a temperature of about 10"C or less, and the mixture is allowed to react at the same temperature for about 5 to about 10 hours to complete coupling, and after the reaction is finished, the deposited product is filtered, washed with water and dried.

The dyes (I) thus obtained can be finely pulverized together with a suitable dispersing agent in an aqueous medium according to methods well known to those skilled in the art, and applied, in a paste form or a powder form after spray-drying, to the dyeing of the foregoing hydrophobic fibers.

In producing 2-cyano-4-nitro-6-chloro-2 '-acetylamino-4'-(N, N-di-n-penyl)amino- 1,1 '-azoben- zene (referred to as "monoazo compound" for brevity hereinafter) of the particular crystal form, the wet cake or dry cake of the monoazo compound produced from the corresponding diazo component (2-cyano-4-nitro-6-chloroaniline) and the corresponding coupling component (3acetylamino-N,N-di-n-pentylaniline) according to the above method, is heat-treated in an aqueous medium or organic solvent (e.g. alcohols, acetice acid) in the presence of a surfactant (e.g. a dispersing agent) if necessary.

As to the amount of the aqueous medium or organic solvent used in the heat treatment, amounts larger than that required to dip the monoazo compound completely are necessary.

Generally, however, amounts larger than about ten times the weight of the monoazo compound are preferably used, because thorough stirring is desirable for avoiding non-uniform heating.

In carrying out the heat treatment, a dispersing agent (e.g. naphthalenesulfonic acid/formalin condensates, naphtholsulfonic aicd/cresol/formalin condensates) or an anionic or nonionic surfactant may be present in the system in an amount of 1 to 400 % by weight based on the weight of the monoazo compound, whereby desirable effects such as a rise in the dispersibility of the dye can be expected.

The heat-treatment temperature is preferably within a range of 80 to 100"C at atmospheric pressure. When the temperaure is lower than 80"C, the effect can not be expected, or, if it can be expected, the heat treatment requires a very long period of time. While, the treatment may also be carried out at a temperature higher than 100"C, but such temperature is not desirable operationally because pressure vessels are required.

The heat-treatment time somewhat varies depending on the temperature, the amount of aqueous medium or organic solvent and the kinds and amounts of other additives, but generally, about 1 to about 5 hours are sufficient.

The thus obtained monoazo compound having the particular X-ray powder diffraction is finely pulverized together with a suitable dispersing agent (e.g. naphthalenesulfonic acid/formalin condensates) in an aqueous medium in a manner known to those skilled in the art and used for dyeing the aforesaid hydrophobic fibers in a paste form or a powder form obtained by spray drying or the like.

In producing the dye compositions of the present invention comprising the azo disperse dyes of the formula (I) and anthraquinone dyes of the formula (IV) or (V), the anthraquinone dyes of the formula (IV) are synthesized by the method disclosed in Japanese Patent Publication No.

9089/1957. Specifically, the following dyes are given:

Further, the anthraquinone disperse dyes of the formula (V) are synthesized by the method disclosed in United States Patent No. 1,652,584. Specifically, the following dyes are given:

The dye composition of the present invention can be obtained by finely pulverizing a mixture comprising at least one member selected from monoazo blue dyes of the formula (I) (including 2-cyano-4-nitro-6-chloro-2'-acetylamino-4'-(N, N-di-n-pentyl)amino- 1 , 1 '-azobenzene of the aforesaid particular crystal form) and at least one member selected from anthraquinone dyes of the formula (IV) and (V), together with a suitable dispersing agent in an aqueous medium according to methods known to those skilled in the art.The resulting dispersion may be used in a paste form or in a powder form after spray drying.

The dyes and dye compositions of the present invention are suitable for dyeing hydrophobic fibers particularly polyester fibers and cellulose ester fibers in a brilliant blue color by methods well known to those skilled in the art. For example, hydrophobic fibers are dyed by dipping them in an aqueous medium containing the present dye or dye composition and treating at 105"C or higher, preferably 110 to 140"C under increased pressure. The fibers may also be dyed at a relatively high temperature, for example at the boiling point of water, in the presence of a carrier such as o-phenylphenol or trichlorobenzene.

Further, the so-called thermosol method may also be applied, that is, hydrophobic fiber cloth may be dyed by padding the cloth with a dye disperse liquor followed by dry-heat treatment at 150 to 230"C for 30 to 60 seconds.

Still further, the dyes and dye compositions of the present invention may effectively be applied to printing method which comprise printing the cloth with a color paste produced from a dye dispersion and a suitable thickening agent, followed by steaming or thermosol treatment.

Also, the dyes and dye compositions may be applied to solvent dyeing methods using an organic solvent (e.g. trichloroethylene, perchloroethylene) as a dyeing medium.

As described above, the azo disperse dyes (I) of the present invention can dye or print the foregoing hydrophobic fibers in a deep and brilliant blue color of excellent dyeing affinity, pH sensitivity (decomposition resistance), sublimation resistance and light fastness as well as of good reproducibility.

Further, by using the monoazo compound of the particular crystal form, all the troubles in dyeing, for example lowering in dispersibility and formation of aggregates, are eliminated, and brilliant, deep and uniform dyed goods can be obtained.

Also, the following advantages can be obtained by using the dye compositions of the present invention: The inherent brilliant shade of anthraquinone dyes is hardly lost; lowering in reproducibility owing to the thermal decomposition of azo dyes is negligible; fastnesses after resin finish are increased; and a buildup property and sublimation fastness in deep dyeing are largely improved.

The present invention will be illustrated in more detail with reference to the following examples and comparative examples, which are not however to be interpreted as limiting the invention thereto. All parts and percents in the examples are by weight.

Fig. 1 and Fig. 2 are schematic diagrams of the X-ray powder diffraction of the monoazo compound not heat-treated after the coupling, and that having the particular crystal form by the heat-treatment of the present invention, respectively. That is, Fig. 1 and Fig. 2 schematically show the graph of diffraction by irradiation of Cu-Ka ray, the graph being recorded by a selfrecording machine equipped with a Geiger counter. The abscissa indicates the diffraction angle (20; Cu-K,,) and the ordinate the relative intensity (R.I.) of diffracted ray. Fig. 3 shows a decomposition percentage-exhaustion percentage characteristic of each dye.Preparation of dyes of the formula (I) and dyeing of hydrophobic fibers using the same: Example 1

3-Acetylaminoaniline (15 parts) was reacted with n-amyl chloride (32 parts) at 1 20' to 1 30 C for 4 hours in the presence of anhydrous sodium carbonate (21.2 parts) to obtain 3acetylamino-N, N-di-n-pentylaniline (coupling component).

The resulting 3-acetylamino-N,N-di-n-pentylaniline was dissolved in methanol (200 parts). 2 Cyano-4-nitro-6-chloroaniline (19.8 parts) was diazotized at a low temperature (1 0 C or less) with nitrosylsulfuric acid, and the resulting diazo liquor was added dropwise to the above coupler liquor at 5"C or less.

After coupling was finished, the deposited product was filtered, washed with water and dried ato obtain 44.8 parts of a dye (1). Yield, 90 % based on the diazo component.

The dye of the formula (1) (3 parts) was finely pulverized together with a naphthalene-ss- sulfonic acid/formalin condensate (3 parts) and sodium lignosulfonate (1.5 parts) to change to a dispersible form and uniformly dispersed in water (3000 parts) together with the sulfuric ester (3 parts) of a higher alcohol to prepare a dye bath.

Tetoron spun yarn (polyester fiber produced by Toray Co.) (100 parts) was dipped in the bath and dyed at 1 30 C for 60 minutes. After dyeing, reduction clearing was applied to the dyed yarn at 85"C for 10 minutes in a liquor comprising sodium hydroxide (3 parts), hydrosulfite (3 parts), a betaine type amphoteric surfactant (3 parts) and water (3000 parts).

Thereafter, the dyed yarn was rinsed and dried to obtain dyed goods of a deep, brilliant and fast royal blue.

Example 2

3-Priopionylaminoaniline (16.4 parts) was reacted with n-amyl ptoluene sulfonate (58.1 parts) at 100"C for 5 hours in a solvent comprising methyl cellosolve (100 parts) and water (100 parts) in the presence of anhydrous sodium carbonate (12.7 parts) to obtain 3-propionylamino N,N-di-n-pentylaniline (coupling component).

In the same manner as in Example 1, 2-cyano-4-nitro-6-chloro-aniline was diazotized and coupled with the above coupling component to obtain 45.1 parts of a dye (2). Yield, 88 % based on the diazo component.

After finely pulverizing the dye (2) (3 parts) together with a naphthalene-ss-sulfonic acid/formalin condensate (3 parts) and sodium lignosulfonate (1.5 parts) to change to a dispersible form, the preparation of a dye bath and dyeing were carried out in the same manner as in Example 1 to obtain dyed goods of a deep, brilliant and fast royal blue.

Example 3

3-Acetylaminoaniline (15 parts) was reacted with n-hexyl chloride (36.2 parts) at 120 to 130"C for 4 hours in the presence of anhydrous sodium carbonate (21.2 parts) to obtain 3 acetylamino-N, N-di-n-hexylaniline (coupling component).

The resulting 3-acetylamino-N,N-di-n-hexylaniline was dissolved in methanol (200 parts). 2 Cyano-4-nitro-6-chloroaniline (19.8 parts) was diazotized at a low temperature (10"C or less) with nitrosylsulfuric acid, and the resulting diazo liquor was added dropwise to the above coupler liquor at 5"C or less.

After coupling was finished, the deposited product was filtered, washed with water and dried to obtain 47.4 parts of a dye (3).

Yield, 90 % based on the diazo component, Ama,, 603 nm (in DMF).

m.p. 137-139"C.

The dye of the formula (3) (3 parts) was finely pulverised together with a naphthalene-ss- sulfonic acid/formalin condensate (3 parts) and sodium lignosulfonate (1.5 parts) to change to a dispersible form and uniformly dispersed in water (3000 parts) together with the sulfuric ester (3 parts) of a higher alcohol to prepare a dye bath.

Tetoron spun yarn (polyester fiber produced by Toray Co.) (100 parts) was dipped in the bath and dyed at 130"C for 60 minutes. After dyeing, reduction clearing was applied to the dyed yarn at 85"C for 10 minutes in a liquor comprising sodium hydroxide (3 parts), hydrosulfite (3 parts), a betaine type amphoteric surfactant (3 parts) and water (3000 parts).

Example 4

3-Propionylaminoaniline (16.4 parts) was reacted with n-heptyl p-toluenesulfonate (64.8 parts) at 100"C for 5 hours in a solvent comprising methyl cellosolve (100 parts) and water (100 parts) in the presence of anhydrous sodium carbonate (12.7 parts) to obtain 3-propionylamino N,N-di-n-heptylaniline (coupling component).

In the same manner as in Example 1, 2-cyano-4-nitro-6-chloroaniline was diazotized and coupled with the above coupling component to obtain 48.8 parts of a dye (4).

Yield, 88 % based on the diazo component.

Am,,, 603 nm (in DMF).

After finely pulverizing the dye (4) (3 parts) together with a naphthalene-ss-sulfonic acid/formalin condensate (3 parts) and sodium lignosulfonate (1.5 parts) to change to a dispersible form, the preparation of a dye bath and dyeing were carried out in the same manner as in Example 3 to obtain dyed goods of a deep, brilliant and fast royal blue.

Example 5

3-Acetylaminoaniline (15 parts) was reacted with n-octyl bromide (19.3 parts) at 90 to 100"C for 4 hours in the presence of anhydrous potassium carbonate (6.9 parts) to obtain 3acetylamino-N-octylaniline. Thereafter, reaction was further continued at 120 to 130"C for 4 hours with addition of n-hexyl bromide (16.5 parts) and anhydrous potassium carbonate (6.9 parts) to obtain 3-acetylamino-N-n-octyl-N-n-hexylaniline (coupling component). In the same manner as in Example 1, 2-cyano-4-nitro-6-chloroaniline was diazotized and coupled with the above coupling component to obtain 45.9 parts of a dye (5).

Yield, 85 % based on the diazo component.

Ama,, 604 nm (in DMF).

After finely pulverizing the dye (5) (3 parts) together with a naphthalene-ss-sulfonic acidformalin condensate (3 parts) and sodium lignosulfonate (1.5 parts) to change to a dispersible form, the preparation of a dye bath and dyeing were carried out in the same manner as in Example 3 to obtain dyed goods of a deep, brilliant and fast royal blue.

Example 6

3-Acetylaminoaniline (15 parts) was reacted with n-hexyl chloride (12.1 parts) at 100" to 110"C for 4 hours in the presence of anhydrous sodium carbonate (5.3 parts) to obtain 3acetylamino-N-hexylaniline. Thereafter, reaction was further continued at 120 to 1 30 C for 4 hours with addition of n-amyl chloride (10.7 parts) and anhydrous sodium carbonate (5.3 parts) to obtain 3-acetylamino-N-n-hexyl-N-n-pentylaniline (coupling component). In the same manner as in Example 1, 2-cyano-4-nitro-6-chloroaniline was diazotized and coupled with the above coupling component to obtain 42.5 parts of a dye (6).

Yield, 83 % based on the diazo component.

Am,,, 603 nm (in DMF).

The dye of the formula (6) (3 parts) was finely pulverized together with a naphthalene-ss- sulfonic acid/formalin condensate (3 parts) and sodium lignosulfonate (1.5 parts) to change to a dispersible form and uniformly dispersed in water (3000 parts) together with the sulfuric ester (3 parts) of a higher alcohol to prepare a dye bath.

Example 7

3-Propionylaminoaniline (16.4 parts) was reacted with n-heptyl p-toluenesulfonate (27 parts) at 100"C for 4 hours in methyl cellosolve (200 parts) in the presence of anhydrous sodium carbonate (5.3 parts) to obtain 3-propionylamino-N-heptylaniline. Thereafter, reaction was further continued at 100" to 110"C for 4 hours with addition of n-amyl p-toluenesulfonate (24.2 parts) and anhydrous sodium carbonate (5.3 parts) to obtain 3-propionylamino-N-n-heptyl-N-npentylaniline (coupling component). In the same manner as in Example 1, 2-cyano-4-nitro-6chloroaniline was diazotized and coupled with the above coupling component to obtain 45.9 parts of a dye (7).

Yield, 85 % based on the diazo component.

Am,,, 602 nm (in DMF).

After finely pulverizing the dye (7) (3 parts) together with a naphthalene-ss-sulfonic acid/formalin condensate (3 parts) and sodium lignosulfonate (1.5 parts) to change to a dispersible form, the preparation of a dye bath and dyeing were carried out in the same manner as in Example 1 to obtain dyed goods of a deep, brilliant and fast royal blue.

Example 8

3-Acetylaminoaniline (15 parts) was reacted with n-octyl bromide (19.3 parts) at 1 00'C for 4 hours in the presence of anhydrous sodium carbonate (5.3 parts) to obtain 3-acetylamino-N-noctylaniline. Thereafter, reaction was further continued at 120 to 130"C for 4 hours with addition of n-amyl bromide (15.1 parts) and anhydrous sodium carbonate (5.3 parts) to obtain 3-acetylamino-N-n-octyl-N-n-pentylaniline (coupling component). In the same manner as in Example 1, 2-cyano-4-nitro-6-chloroaniline was diazotized and coupled with the above coupling component to obtan 43.8 parts of a dye (8).

Yield, 81 % based on the diazo component.

Am,,, 601 nm (in DMF).

After finely pulverizing the dye (8) (3 parts) together with a naphthalene-ss-sulfonic acid/formalin condensate (3 parts) and sodium lignosulfonate (1.5 parts) to change to a dispersible form, the preparation of a dye bath and dyeing were carried out in the same manner as in Example 1 to obtain dyed goods of a deep, brilliant and fast royal blue.

Example 9

3-Acetylamino-N,N-di-n-pentylaniline was synthesized in the same manner as in Example 1, and this product (29.0 parts) was dissolved in methanol (200 parts) to obtain a coupler liquor.

2-Cyano-4-nitro-6-bromoaniline (24.2 parts) was diazotized at a low temperature (1 0'C or less) with nitrosylsulfuric acid, and resulting diazo liquor was added dropwise to the above coupler liquor at 5"C or less. After coupling was finished, the deposited product was filtered, washed with water and dried to obtaon 48.9 parts of 2-cyano-4-nitro-6-bromo-2'-acetylamino-4'-(N,N-din-pentyl)-amino-1,1 '-azobenzene.

The whole amount of the resulting product was dissolved in DMF (250 parts), and cuprous cyanide (10 parts) was added thereto at room temperature over about 2 hours. Thereafter, stirring was continued at room temperature for 1 8 hours to complete the reaction. Insoluble inorganic substances produced were removed by filtration, and the filtrate was poured into methanol (1000 parts). The deposited crystals were filtered, washed with water and dried to obtain 40.0 parts of a dye (9).

Overall yield, 81.8 % Am,,, 647 nm (in DMF).

Example 10

3-Propionylamino-N,N-di-n-penthylaniline was synthesized in the same manner as in Example 2, and this product (30.4 parts) was dissolved in methanol (200 parts) to obtain a coupler liquor. In the same manner as in Example 9, 2-cyano-4-nitro-6-bromoaniline was diazotized and coupled with the above coupler to obtain 2-cyano-4-nitro-6-bromo-2'-propionylamino-4'-(N,N-di- n-pentyl)-amino-1,1'-azobenzene. The resulting product was dried and changed to a cyano compound with cuprous cyanide in the same manner as in Example 9 to obtain 40.2 parts of a dye (10).

Overall yield, 80 % Am,,, 645 nm (in DMF).

Comparative Examples The decomposition resistance and dyeability of the present compounds were compared with those of the foregoing well-known dyes. The results are shown in Table 1.

Table 1 Decomposition Dyeability resistance (1) (2) Example 1 18 96 Example 2 20 93 Example 3 17 95 Example 4 15 91 Present Example 5 14 90 dyes Example 6 19 96 Example 7 18 95 Example 8 16 91 Example 9 28 91 Example 10 30 93 A-1 92 97 A-2 86 96 A-3 78 95 A-4 65 85 B-1 56 72 B-2 20 15 B-3 10 10 or less Comparative B-4 75 90 dyes B-5 20 10 or less B-6 10 10 or less C-1 63 95 C-2 18 37 C-3 57 80 C-4 70 94 C-S 60 93 C-6 10 15 Well-known dye 1 95 98 Well-known dye 11 97 99 Well-known dye Ill 89 96 Note (1) Decomposition resistance (decomposition percentage) Weight of a dye in a dye Decomposition bath after treatment percentage (%) = 100 X (1 - I Weight of a dye used Treatment conditions:: 140"C X 30 minutes, pH 7 Composition of dye bath: Dye conc. cake 3 parts Napthalene-ss-sulfonic acid type dispersing agent 3 parts Lignosulfonic acid type dispersing agent 1.5 parts Sulfuric ester of higher alcohol 3 parts Water 3000 parts Decomposition percentage is a numerical illustration of pH sensitivity, and smaller values are desirable because they mean less decomposition.

Note (2) Dyeability (exhaustion percentage) Weight of a dye in a Exhaustion residual bath after dyeing percentage (%) =100X(1 - ~~~~~~~~~~~~~~~~~~~~~~ Weight of a dye used Dyeing conditions: 130"C X 60 minutes, pH 5 Composition of dye bath: Dye conc. cake 3 parts Naphthalene-ss-sulfonic acid type dispersing agent 3 parts Lignosulfonic acid type dispersing agent 1.5 parts Sulfuric ester of higher alcohol 3 parts Water 3000 parts Fig. 3 is a diagram obtained by plotting the data in Table 1 with decomposition percentage as ordinate and exhaustion percentage as abscissa. Dyes having a smaller decomposition percentage and a larger exhaustion percentage, that is, those present in the top right-hand region in Fig. 3 have a practical value.The dyes alone of the present invention are present in the top right-hand region, which means that they have an excellent practical value.

Preparation of the dye having the particular crystal form and dyeing of hydrophobic fibers using the same: Example 11 2-Cyano-4-nitro-6-chloroaniline (19.8 parts) was diazontized with nitrosylsulfuric acid to obtain a diazo liquor. 3-Acetylamino-N,N-di-n-pentylaniline (29 parts) was dissolved in methanol (150 parts), and the above diazo liquor was added thereto at 0 to 5"C to carry out coupling while adding ice to the methanol solution. After reaction was finished, the deposited product was filtered, and washed with water to obtain 1 50 parts of 2-cyano-4-nitro-6-chloro-2'-acetylamino 4'-(N,N-di-n-pentyl)amino-1 , 1 '-azobenzene wet cake (corresponding to 43.8 parts converted to a dry basis). The X-ray powder diffraction of this product is schematically shown in Fig. 1.

This wet cake (150 parts) was suspended in water (1500 parts) and heat-treated at 95"C for 3 hours with stirring. After cooling, the cake was filtered and washed with water to obtain 1 35 parts of a dye wet cake (corresponding to 43.8 parts converted to a dry basis). The X-ray powder diffraction of the dye is schematically shown in Fig. 2.

2-Cyano-4-nitro-6-chloro-2'-acetylamino-4'-(N, N-di-n-pentyl)amino- 1 , 1 '-azobenzene having the above particular crystal form (3 parts) was finely pulverized together with a naphthalene-fl- sulfonic acid/formalin condensate (3 parts) and sodium lignosulfonate (1.5 parts) to change to a dispersible form, and uniformly dispersed in water (3000 parts) together with the sulfuric ester (3 parts) of a higher alcohol to prepare a dye bath.

Tetoron spun yarn (polyester fiber produced by Toray Co.) (100 parts) was dipped in the bath and dyed at 130"C for 60 minutes. After dyeing, reduction clearing was applied to the dyed yan at 85"C for 10 minutes in a liquor comprising sodium hydroxide (3 parts), hydrosulfite (3 parts), a betaine type amphoteric surfactant (3 parts) and water (3000 parts). Thereafter, the dyed yarn was rinsed and dried to obtain dyed goods of a deep, brilliant and fast royal blue.

This dyed product was uniform in depth and showed no specks owing to dye aggregation at all.

Example 1 2 2-Cyano-4-nitro-6-chloro-21-acetylamino-4'-(N, N-di-n-pentyl)amino- 1,1 '-azobenzene wet cake (150 parts; corresponding to 43.9 parts converetd to a dry basis) obtained by diazotization and coupling in the same manner as in Example 11, was suspended in water (1500 parts), and acetic acid (100 parts) was added thereto, followed by heat treatment at 90"C for 3 hours with stirring. After cooling, the product was filtered and washed with water to obtain 140 parts of a dye wet cake (corresponding to 43.5 parts converted to a dye basis). The X-ray powder diffraction of the dye was the same as that in Fig. 2.

Dyeing was carried out in the same manner as in Example 11 using the dye thus obtained. As a result, the same good dyeing results as in Example 11 were obtained.

Example 1 3 2-Cyano-4-nitro-6-chloro-2'-acetyla m ino-4'-(N, N-d i-n-pentyl )ami no- 1 , 1 '-azobenzene wet cake (150 parts; corresponding to 43.9 parts converted to a dry basis) obtained by diazotization and coupling in the same manner as in Example 11, was suspended in water (1500 parts), and a naphthalenesulfonic acid/formalin condensate (50 parts) was added thereto, followed by heat treatment at 90"C for 2 hours with stirring. After cooling, the product was filtered and washed with water to obtain 1 36 parts of a dye wet cake (corresponding to 43.6 parts converted to a dry basis). The X-ray powder diffraction of the dye was the same as that in Fig. 2.

Dyeing of hydrophobic fibers using particular dye compositions: Example 14 A mixed dye comprising a dye of the formula (IV-1) (1.5 parts),

and a dye of the formula (1-1) (1.5 parts),

was finely pulverized together with a naphthalenesulfonic acid/formaldehyde condensate (3.0 parts) to change to a dispersible form and uniformly dispersed in an aqueous solution (3000 parts) containing the sulfuric ester (3.0 parts) of a higher alcohol to prepare a dye bath. Tetoron spun yarn (polyester fiber produced by Toray Co.) (100 parts) was dipped in the dye bath and dyed at 130"C for 60 minutes in a pressure vessel with stirring.After dyeing, reduction clearing was applied to the dyed yarn at 85"C for 10 minutes in an aqueous solution (3000 parts) containing sodium hydroxide (3 parts), hydrosulfite (3 parts) and a betaine type amphoteric surfactant (3 parts). Thereafter, the yarn was rinsed and dried to obtain dyed goods of a deep, brilliant and fast blue. The fastness and brilliance of shade are shown in Table 2.

Example 15 A mixed dye comprising the above dye of the formula (IV-1) (1.5 parts) and a dye of the formula (1-2) (1.5 parts),

was finely pulverized together with a naphthalene-ss-sulfonic acid/formaldehyde condensate (3.0 parts) to change to a dispersible form. Thereafter, dyeing was carried out in the same manner as in Example 14 to obtain dyed goods of a deep, brilliant and fast blue. The fastness and brilliance of shade are shown in Table 2.

Dyeing was carried out in the same manner using the mixed dyes described below to obtain dyed goods of a deep, brilliant and fast blue.

Anthraquinone dyes Azo dyes Example 16 IV-1 0.75 part 1-1 2.25 parts Example 17 IV-1 0.75 part 1-2 2.25 parts Example 18 A mixed dye comprising a dye of the formula (IV-2) (1.5 parts),

and the above dye of the formula (1-1) (1.5 parts) was finely pulverized together with a naphthalene-fl-sulfonic acid/formaldehyde condensate (3.0 parts) to chang to a dispersible form.

Thereafter, dyeing was carried out in the same manner as in Example 14 to obtained dyed goods of a deep, brilliant and fast blue. The fastness and brilliance of shade are shown in Table 2.

Anthraquinone dyes Azo dyes Example 1 9 IV-2 1.5 parts 1-2 1.5 parts Example 20 IV-2 0.75 part 1-1 2.25 parts Example 21 IV-2 0.75 part 1-2 2.25 parts Example 22 A mixed dye comprising a dye of the formula (V-1) (1.5 parts),

and the above dye of the formula (1-1) (1.5 parts) was finely pulverized together with a naphthalanesulfonic acid/formaldhyde condensate (3.0 parts) to change to a dispersible form and uniformly dispersed in an aqueous solution (3000 parts) containing the sulfuric ester (3.0 parts) of a higher alcohol to prepare a dye bath. Tetoron spun yarn (polyester fiber produced by Toray Co.) (100 parts) was dipped in the dye bath and dyed at 130"C for 60 minutes in a pressure vessel with stirring.After dyeing, reduction clearing was applied to the dyed yarn at 85"C for 10 minutes in an aqueous solution (3000 parts) containing sodium hydroxide (3 parts), hydrosulfite (3 parts) and a betaine type amphoteric surfactant (3 parts). Thereafter, the yarn was rinsed and dried to obtain dyed goods of a deep, brilliant and fast blue. The fastness and brilliance of shade are shown in Table 2.

Example 23 A mixed dyd comprising the above dyes of the formulae (V-1) and (1-2) (1.5 parts for each dye) was finely pulverized together with a naphthalene-ss-sulfonic acid/formaldehyde condensate (3.0 parts) to change to a dispersible form. Thereafter, dyeing was carried out in the same manner as in Example 1 4 to obtain dyed goods of a deep, brilliant and fast blue. The fastness and brilliance of shade are shown in Table 2.

Anthraquinone dyes Azo dyes Example 24 V-1 0.75 part 1-1 2.25 parts Example 25 V-1 0.75 part 1-2 2.25 parts The results of Examples 1 4 to 25 are shown in Table 2 together with those of comparative experiments which were carried out in the same manner as in Examples 14 to 15 using the well-known compounds I, II and Ill.

Table 2 Mixing ratio of dyes Stability Sublimation Anthraquinone in a dye resistance Brilliance dyes Azo dyes bath (rating) of shade (IV-1) 100% - 100% 2 10.2 (IV-2) 100 % - 100 2 10.2 (IV-1) 50% (1-1) 50% 93 3 10.1 (IV-1) 50 % (1-2) 50 % 95 3 10.0 (IV-1) 50 % Known compound 1 50 % 60 2-3 8.0 (IV-1) 50 % Known compound 11 50 % 55 2-3 10.0 (IV-1) 25 % (1-1) 75 % 91 3 10.0 (IV-1) 25 % (1-2) 75 % 92 3-4 10.0 (Vl-1) 25 % Known compound 1 75 % 45 2-3 7.7 (IV-1) 25 % Known compound 11 75 % 35 2-3 10.0 (IV-2) 50 % (1-1) 50 % 92 3 10.1 (IV-2) 50 % (1-2) 50 % 96 3 10.1 (IV-2) 50 % Known compound 1 50 % 63 2-3 7.9 (IV-2) 50 % Known compound 11 50 % 56 2-3 10.1 (IV-2) 25 % (1-1) 75 % 90 3 10.0 (IV-2) 25 % (1-2) 75 % 93 3-4 10.0 (IV-2) 25 % Known compound 1 75 % 50 2-3 7.5 (IV-2) 25 % Known compound 11 75 % 34 2-3 10.0 (V-1) 100% 100 3-4 9.0 (V-1) 50 % (1-1) 50 % 92 3-4 9.5 (V-1) 50 % (1-2) 50 % 94 3-4 9.4 (V-1) 50 % Known compound Ill 50 % 65 3 8.1 (V-1) 25 % (1-1) 75 % 90 3-4 9.6 (V-1) 25 % (1-2) 75 % 92 3-4 9.5 (V-l) 25 % Known compound Ill 75 % 55 3 7.9 Note: (1) Stability in a dye bath A dye bath was treated under the conditions: Dye concentration 0.3 g/l, pH 7, and 140C x 30 min. The absorbance of the bath before and after the treatment was measured and the ratio of the both values was calculated.

Absorbance of a bath after treatment x 1 00 (%) Absorbance of a bath before treatment (2) Sublimation resistance Sublimation resistance was evaluated on the basis of the degreero.f staining on polyester cloth according to JIS L0879. Depth of dyed goods to be tested: medium depth specified in JIS Test condition: 185C x 30 seconds (3) Brilliance of shade The spectral reflectance of dyed goods to be tested was measured, and saturation (C) was calculated from the three primaries X, Y and Z of the goods using the reflectance according to JIS Z 8721. The saturation was taken as the measure of brilliance.

Claims

1. A compound of the formula,

in which R1 is a methyl or ethyl group, R2 and R3 are each C5 to C8 alkyl, and Z is a chloro or cyano group.

2. A compound as claimed in Claim 1, in which either of R2 and R3 is C5 or C6 alkyl and Z is a chloro group.

3. A compound as claimed in Claim 1 or Claim 2, in which R2 and R3 are each straight C5 or C6 alkyl, and Z is a chloro group.

4. A compound as claimed in any one of Claims 1 to 3, in which the compound is 2-cyano 4-nitro-6-chloro-2'-acetylamino-4'-(N, N-di-n-pentyl)amino- 1 , 1 '-azobenzene.

5. A compound as claimed in Claim 4, in which 2-cyano-4-nitro-6-chloro-2'-acetylamino-4' (N,N-di-n-pentyl)amino-1 , 1 '-azobenzene is of a crystal form showing a great relative intensity at each angle of an X-ray powder diffraction (28; Cu-Ka) of 14.0 , 18.5 , 21.4 and 25.6', and a medium relative intensity at the angle of 11.2", 12.6 , 16.0 , 17.6 , 19.2", 23.5 , 24.2 and 26.4".

6. A dye composition comprising 98 to 5% by weight of an anthraquinone dye of the formula,

in which one of X and Y is an amino group and the other is a hydroxy group, and n is a number satisfying the equation O < n < 2, or

in which R is hydrogen or a lower alkyl group and 2 to 95% by weight of a compound of the formula (I),

in which R' is a methyl or an ethyl group, R2 and R3 are each C5 to C8 alkyl, and Z is a chloro or cyano group.

7. The dye composition as claimed in Claim 6, wherein the compound of the formula (I) is 2-cyano-4-nitro-6-chloro-2'-acetylamino-4'-(N,N-di-n-pentyl)amino-1,1'-azobenzene of a crystal form showing a great relative intensity at each angle of an X-ray powder diffration (28; Cu-Ka) of 14.0 , 18.5 , 21.4 and 25.6 , and a medium relative intensity at the angle of 11.2", 12.6 , 16.0 , 17.6 , 19.2", 23.5 , 24.2 and 26.4 .

8. A process for producing a compound of the formula (I),

in which R' is a methyl or ethyl group, R2 and R3 are each C5 to C8 alkyl, and Z is a chloro or cyano group which comprises reacting a diazotized compound of the formula (II),

in which Z is as defined above, with a compound of the formula (III),

in which R', R2 and R3 are as defined above.

9. A process as claimed in Claim 8, in which the reaction is effected by dissolving the compound of the formula (III) in a mineral acid or an organic solvent and then adding to the resulting solution the diazotized compound of the formula (II) at a temperature of about 10"C or below.

10. A process for producing 2-cyano-4-nitro-6-chloro-2'-acetylamino-4'-(N, N-di-n-pentyl)am- ino-i , 1 '-azobenzene of a crystal form showing a great relative intensity at each angle of an X-ray powder diffraction (20; Cu-Ka) of 14.0 , 18.5 , 21.4 and 25.6 , and a medium relative intensity at the angle of 11.2", 12.6 , 16.0 , 17.6 , 19.2", 23.5 , 24.2 and 26.4", which comprises reacting diazotized 2-cyano-4-nitro-6-chloroaniline with 3-acetylamino-N, N-di-n-penty- laniline to obtain a monoazo compound, 2-cyano-4-nitro-6-chloro-2'-acetylamino-41-(N, N-di-n- pentyl)amino-1 , 1 '-azobenzene, and then heating the resulting monoazo compound in an aqueous medium or an organic solvent, if desired, in the presence of a surfactant.

11. A process as claimed in Claim 10, wherein the heating is effected at a temperature of 80 to 100 C.

12. A process substantially as herein described with reference to any one of Examples 1 to 25.

13. A process for dyeing a hydrophobic fiber which comprises contacting a hydrophobic fiber with a compound as claimed in any one of Claims 1 to 7 and 1 2.

14. A dye composition substantially as herein described with reference to any one of Examples 1 to 25.

1 5. Any novel integer or feature or combination of item, integer and/or feature, or any novel compound, composition or process substantially as herein described.