JPS5943497B2 - Method for producing 4-nitro-4'-(N-cyanoethyl-N'-benzoylethyl)amino-1,1'-azobenzene with excellent high-temperature dispersion stability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides 4-nitro 4 with excellent dispersion stability at high temperatures.
The present invention relates to a method for producing '-(N-cyanoethyl-N/-benzoylethyl)aminol,1'-azovessel.

4-Nitro 4L (N-cyanoethyl-N'-benzoylethyl)-aminol,1'-azobenzene (hereinafter this compound will be abbreviated as NCBA) is an orange dye useful for hydrophobic fibers, especially polyester fibers, and Diazotize nitroaniline to form N-cyanoethyl-N/-
It is produced by coupling reaction with benzoylethylaniline, but the dye produced in this way does not have sufficient dispersion stability at high temperatures, and when high-temperature dyeing is carried out using a dye bath prepared using this cake, it often The dispersibility of the dye deteriorates, causing aggregation of the dye, resulting in problems such as poor penetration into the interior of the fiber, uneven dyeing, and decreased fastness.

As a result of extensive research by the present inventors to improve the above points, we found that NCBA has a crystal form with excellent high-temperature stability (hereinafter referred to as γ-type) and a crystal form with insufficient high-temperature stability (
NCBA produced by the coupling reaction is an α-type crystal, and α-type NCBA must be heated at a high temperature of 130°C or higher depending on the heating in water. The present invention was completed based on the knowledge that, although no crystal transition occurs in the case of crystals, the transition to the γ type can be easily carried out even at temperatures of 80 to 100°C in the presence of a specific substance.

That is, the present invention provides NCs with excellent dispersibility at high temperatures.
The purpose is to industrially advantageously produce BA, and this purpose is to diazotize paranitroaniline,
NCBA obtained by a coupling reaction with N-cyanoethyl-N'-benzoylethylaniline was added to an aqueous medium containing an aromatic compound consisting of 1 to 2 benzene nuclei which may have a substituent at a concentration of 80 to 100%. This is achieved by heat treatment at a temperature of °C.

To explain the present invention in more detail, the NC used in the present invention
BA is produced by diazotizing paranitroaniline and coupling it with N-cyanoethyl-N'-benzoylethylaniline according to known methods.

To subject this NCBA to the heat treatment of the present invention, it may be a wet cake obtained from a coupling reaction system or a powder obtained by drying this NCBA. The amount of aqueous medium used for heat treatment can be carried out as long as it is at least the amount that can sufficiently immerse the NCBA, but since it is preferable to perform stirring to avoid uneven heating, the amount of aqueous medium used should be at least the amount that can sufficiently stir. Usually, it is preferable to use the aqueous medium at least about 10 times the weight of NCBA, but the amount of the aqueous medium is not critical.

Examples of aromatic compounds consisting of 1 to 2 benzene nuclei that may have substituents present during the heat treatment of the present invention include benzene, naphthalene, and diphenyl compounds, and these substituents include Alkyl group, alkoxy group, carboxy group, alkoxycarbonyl group, hydroxyl group,
Examples include halogen atoms.

Specific examples of these aromatic compounds include benzene, toluene, xylene, phenol, chlorobenzene, dichlorobenzene, benzoic acid, methyl benzoate, butyl benzoate, methyl salicylate, dimethyl terephthalate, phthalic acid, naphthalene, α-methyl Naphthalene, β-methylnaphthalene, chlornaphthalene, diphenyl, 0-phenylphenol, p-phenylphenol, other N-
Examples include N-alkylphthalimides such as methylphthalimide. The effect is recognized when the amount of these aromatic compounds used is 0.2% by weight or more based on the aqueous medium, but it is usually about 1-10% by weight, preferably about 2-5% by weight.

1. In the aqueous medium of the present invention, a dispersant such as a formaldehyde condensate of naphthalene sulfonic acid, a formaldehyde condensate of naphthol sulfonic acid and cresol, or a surfactant may be present.
Favorable effects can be expected by helping dispersion of BA and dissolution of aromatic compounds.

The temperature of the heat treatment of the present invention is in the range of 80 to 100°C.

If it is lower than this, no effect can be expected or an extremely long treatment time will be required. Although it is possible to carry out the process at a temperature of 100° C. or higher, it requires a pressure-resistant container and is not advisable from an operational point of view. The time for the heat treatment varies slightly depending on the temperature, amount of aqueous medium, type and amount of aromatic compounds and other additives, etc., but usually about 1 to 5 hours is sufficient. After performing the heat treatment in this manner, a large amount of NCBA is removed, and if necessary, washing or hanging washing is performed with water, hot water, alcohol, or the like. Preparation of the powder dye, preparation of the dye bath and dyeing operations are carried out according to conventional methods. When using the method of the present invention, N
CBA can undergo crystal transition under industrially easy conditions of normal pressure and 80 to 100°C, and moreover, the crystal transition is more complete than that of NCBA, which has a transition of about 13'C in water, and is dispersible at high temperatures. Because of its excellent stability, its industrial value is extremely high.

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to the following examples unless it exceeds the gist thereof.

In addition, "part" in an Example shows a weight part. Example 1 8.5 parts of paranitroaniline was diazotized and coupled with 19.3 parts of N-cyanoethyl-N'-benzoylethylaniline, filtered and washed to form NCBA wet cake 5.
0 parts (25 parts in terms of solids) were obtained.

(This α-type NCBAO) X-ray diffraction was as shown in FIG. ) 50 parts of this wet cake was suspended in 200 parts of an aqueous medium containing 5 parts of methylnaphthalene, and stirred and heated at 95° C. for 5 hours.

After cooling, 40 parts of NCBA cake (solid equivalent: 2
3 copies) was taken out. When this γ-type NCBAOX X-ray diffraction was performed, the results shown in FIG. 2 were obtained. To this cake, 38 parts of a formalin condensate of naphthalene sulfonic acid, 39 parts of a dispersant mainly composed of sodium ligninsulfonate, and 200 parts of water were added to make a fine colloidal liquid in a sand mill, and then spray-dried to make a dye. (Quantity: 75 copies)
.

30 parts of the above dye, 5 parts of the dyeing aid Dispa-VG (manufactured by Meisei Kagaku Co., Ltd.) and 10 parts of ammonium sulfate were dispersed in water, and acetic acid was added to prepare 5,000 parts of a dye bath with a pH of 5.0 and 1 corn cheese dyeing. 900 parts polyester/cotton (65
/35) cone was dyed at 130°C for 30 minutes. In the obtained dyed product, both the inner layer and the outer layer were uniformly dyed orange, and no aggregates were observed at all.

Comparative Example 1 Example 1 was carried out using the NCBA wet cake obtained by coupling reaction without performing the heat treatment of Example 1.
When the dye and dye bath were prepared in the same manner as in , and dyeing was carried out in the same manner, the dyed product obtained had a significant difference in concentration between the inner and outer layers, and aggregates were formed.

Comparative Example 2 Instead of the heat treatment in Example 1, 50 parts of the NCBA wet cake obtained by the coupling reaction was suspended in 200 parts of water, and heat treated with stirring at 95°C for 20 hours to obtain NCBA (
X-ray diffraction was as shown in Figure 3.

Other operations were carried out in the same manner as in Example 1.
The obtained dyed product had a remarkable difference in concentration between the inner and outer layers, and aggregates were formed, and there was no difference from that of Comparative Example 1. Comparative Example 3 Instead of the heat treatment in Example 1, 50 parts of the NCBA wet cake obtained from the coupling reaction was placed in an autoclave with 200 parts of water and heat-treated at 130°C for 1 hour to obtain NCBA (X edge cycle). The analysis was as shown in Figure 4.

) Other operations were carried out in the same manner as in Example 1, and although a favorable trend was observed compared to Comparative Examples 1 and 2, satisfactory results were not obtained in terms of aggregate formation. Example
2 In place of methylnaphthalene in Example 1, 5 parts of an equal weight mixture of heptanochlorobenzene, o-dichlorobenzene and p-dichlorobenzene was used, and the same procedure was repeated except that Example 1 was obtained. A dye similar to that in was obtained.

As can be seen from the figure, NCBA obtained by heat treatment in water at 95°C for 5 hours according to the method of Comparative Example 2 (although the figure in Figure 3 has changed from the α-type crystal of the coupling reaction (Figure 1), No improvement in dispersion stability was observed at high temperatures.

In addition, NCBA obtained by heat treatment in water at 130°C under pressure according to the method of Comparative Example 3 (Fig. 4) has changed to a γ-type crystal type, but the crystal growth is insufficient and it cannot be used at high temperatures. Although an improvement in dispersion stability is observed, it is not sufficient for practical use.

[Brief explanation of drawings]

Figure 1 shows α-type crystal NCB obtained by coupling reaction.
Figure 2 shows the X-ray diffraction diagram of γ-type crystal obtained by heat-treating the above-mentioned NCBA by the method of Example 1 of the method of the present invention.
The X-ray diffraction diagram of BA, FIG. 3 is NCBAOX obtained by heat-treating the above α-type crystal NCBA by the method of Comparative Example 2.
Line diffraction diagram, Figure 4 shows NCBA of the above α-type crystal in Comparative Example 3.
It is an NCBAO) X-ray diffraction diagram obtained by heat treatment according to the method described above.

Claims (1)

[Claims] 1 4-nitro-4'-(N-cyanoethyl-N'-benzoylethyl)amino-1, obtained by diazotizing paranitroaniline and coupling it with N-cyanoethyl-N'-benzoylethylaniline. 1
'-azobenzene in an aqueous medium (containing at least 0.2% by weight of a benzene or naphthalene compound optionally substituted with a lower alkyl group or a halogen atom, based on the aqueous medium) at a temperature of 80 to 100 °C. A method for producing 4-nitro-4'-(N-cyanoethyl-N'-benzoylethyl)amino-1,1'-azobenzene, which has excellent high-temperature dispersion stability, characterized by carrying out a heat treatment for at least 1 hour.