Benzothiazolemonoazo dyes

Abstract

A monoazo dye of the following formula (I): ##STR1## wherein R is phenyl, phenoxy or benzyl, and D is a group of the formula (D1), (D2), (D3) or (D4): ##STR2## wherein each of X.sup.1, X.sup.2 and X.sup.3, which are independent of one another, is hydrogen or chlorine, X.sup.4 is hydrogen, chlorine, methyl or --NHCOR.sup.1, wherein R.sup.1 is C.sub.1-4 alkyl or phenyl; ##STR3## wherein X.sup.4 is as defined above, Y.sup.1 is hydrogen, chlorine or C.sub.1-4 alkoxy; ##STR4## wherein X.sup.5 is hydrogen, halogen, methyl or --NHZ, wherein Z is C.sub.1-4 alkylsurfonyl, C.sub.1-4 alkylcarbonyl, phenylsulfonyl, phenylcarbonyl, C.sub.1-2 alkoxy C.sub.1-2 alkylcarbonyl or aminocarbonyl, Y.sup.2 is hydrogen, methyl or C.sub.1-2 alkoxy, and Q.sup.1 is cyano or C.sub.1-4 alkylcarbonyl; ##STR5## wherein P is formyl, nitro or cyano, Q.sup.2 is cyano or nitro, T is halogen, methyl, phenyl or methylsulfonyl, X.sup.5 is as defined above, and Y.sup.3 is hydrogen or C.sub.1-2 alkoxy.

Description

The present invention relates to water-insoluble monoazo dyes, particularly monoazo dyes suitable for dyeing polyester fibers. More particularly, it relates to red, blue or reddish purple monoazo dyes suitable for dyeing fine denier polyester fibers.

Recently polyester fibers have remarkably advanced toward finer fibers to provide textiles of high added values having comfortable touch or high quality, and various fine denier fibers of less than 0.3 d, so-called ultramicro fibers, have been developed and extensively used. However, when ultramicro fibers having small diameters are dyed with conventional dyes, there is a problem that the wet color fastness such as color fastness to washing substantially decreases.

The object of the present invention is to provide a red, blue or reddish purple disperse dye capable of giving dyed products having not only good color fastness to washing but also excellent color fastnesses to perspiration (alkali).

The present invention provides a monoazo dye of the following formula (I): ##STR6## wherein R is phenyl, phenoxy or benzyl, and D is a group of the formula (D1), (D2), (D3) or (D4): ##STR7## wherein each of X.sup.1, X.sup.2 and X.sup.3, which are independent of one another, is hydrogen or chlorine, X.sup.4 is hydrogen, chlorine, methyl or --NHCOR.sup.1 wherein R.sup.1 is C.sub.1-4 alkyl or phenyl; ##STR8## wherein X.sup.4 is as defined above, Y.sup.1 is hydrogen, chlorine or C.sub.1-4 alkoxy; ##STR9## wherein X.sup.5 is hydrogen, halogen, methyl or --NHZ, wherein Z is C.sub.1-4 alkylsulfonyl, C.sub.1-4 alkylcarbonyl, phenylsulfonyl, phenylcarbonyl, C.sub.1-2 alkoxy C.sub.1-2 alkylcarbonyl or aminocarbonyl, Y.sup.2 is hydrogen, methyl or C.sub.1-2 alkoxy, and Q.sup.1 is cyano or C.sub.1-4 alkylcarbonyl; ##STR10## wherein P is formyl, nitro or cyano, Q.sup.2 is cyano or nitro, T is halogen, methyl, phenyl or methylsulfonyl, X.sup.5 is as defined above, and Y.sup.3 is hydrogen or C.sub.1-2 alkoxy.

Now, the present invention will be described in detail.

The monoazo dye of the above formula (I) covers the following four types of monoazo dyes represented by the formulae (I-1), (I-2), (I-3) and (I-4): ##STR11## wherein X.sup.1, X.sup.2, X.sup.3, X.sup.4 and R are as defined above; ##STR12## wherein X.sup.4, Y.sup.1 and R are as defined above; ##STR13## wherein X.sup.5, Y.sup.2, Q.sup.1 and R are as defined above; ##STR14## wherein P, Q.sup.2, T, X.sup.5, Y.sup.3 and R are as defined above.

In the formulae (I-1) and (I-2), when X.sup.4 is --NHCOR.sup.1, C.sub.1-4 alkyl for R.sup.1 is linear or branched C.sub.1-4 alkyl such as methyl, ethyl, n-propyl, i-propyl or n-butyl.

In the formulae (I-3) and (I-4), halogen for T or X.sup.5 is chlorine or bromine, preferably chlorine. When X.sup.5 is --NHZ, C.sub.1-4 alkylsulfonyl for Z is linear or branched alkylsulfonyl such as methylsulfonyl, ethylsulfonyl, n-propylsulfonyl, i-propylsulfonyl, n-butylsulfonyl or sec-butylsulfonyl.

As C.sub.1-4 alkylcarbonyl, C.sub.1-4 linear or branched alkylcarbonyl such as methylcarbonyl, ethylcarbonyl, n-propylcarbonyl, i-propylcarbonyl, n-butylcarbonyl or i-butylcarbonyl may be mentioned.

Among them, C.sub.1-2 alkylsulfonyl and C.sub.1-2 alkylcarbonyl are particularly preferred. As C.sub.1-2 alkoxy C.sub.1-2 alkylcarbonyl for Z, methoxymethylcarbonyl, ethoxymethylcarbonyl, methoxyethylcarbonyl or ethoxyethylcarbonyl may be mentioned. Particularly preferred is methoxymethylcarbonyl. As C.sub.1-2 alkoxy for Y.sup.2 or Y.sup.3, methoxy or ethoxy may be mentioned

In the formula (I-3), as C.sub.1-4 alkylcarbonyl for Q.sup.1, methylcarbonyl, ethylcarbonyl, n-propylcarbonyl or n-butylcarbonyl may be mentioned. Particularly preferred is C.sub.1-2 alkylcarbonyl.

Among the dyes of the present invention represented by the formula (I), the following dyes (1) to (5) are preferred:

(1) a dye of the formula (I-1), wherein X.sup.1 is hydrogen, at least one of X.sup.2 and X.sup.3 is chlorine, --NHCOR.sup.1 is acetylamino or benzoylamino, and R is phenyl, which is represented by the following formula (I-1-1): ##STR15## wherein one of X.sup.2-1 and X.sup.3-1 is chlorine, the other is hydrogen, and X.sup.4-1 is acetylamino or benzoylamino; (2) a dye of the formula (I-1), wherein X.sup.1 is chlorine, X.sup.2 and X.sup.3 are hydrogen, --NHCOR.sup.1 is acetylamino, and R is phenyl, which is represented by the following formula (I-1-2); ##STR16## (3) a dye of the formula (I-2) wherein X.sup.4 is hydrogen, methyl or C.sub.1-2 alkylcarbonylamino, Y.sup.1 is hydrogen, and R is phenyl, especially a dye of the formula (I-2) wherein X.sup.4 and Y.sup.1 are hydrogen, and R is phenyl, which is represented by the following formula (I-2-1); ##STR17## (4) a dye of the formula (I-3) wherein X.sup.5 is C.sub.1-2 alkylcarbonylamino or methoxymethylcarbonylamino, Y.sup.2 is hydrogen, Q.sup.1 is cyano or methylcarbonyl, and R is phenyl; (5) a dye of the formula (I-4) wherein X.sup.5 is C.sub.1-2 alkylcarbonylamino or methoxymethylcarbonylamino, Y.sup.3 is hydrogen, R is phenyl, P is formyl, Q.sup.2 is cyano, and T is halogen.

The monoazo dye of the formula (I-1) is prepared, for example, by diazotizing an amine of the following formula (II): ##STR18## wherein X.sup.1, X.sup.2 and X.sup.3 are as defined above, by a conventional method, followed by coupling with an aniline of the following formula (III): ##STR19## wherein X.sup.4 and R are as defined above.

The monoazo dye of the formula (I-2) is prepared, for example, by diazotizing 2-amino-6-nitrobenzothiazole by a conventional method, followed by coupling with an aniline of the following formula (IV): ##STR20## wherein X.sup.4, Y.sup.1 and R are as defined above.

The monoazo dye of the formula (I-3) is prepared, for example, by diazotizing an amine of the following formula (V): ##STR21## wherein Q.sup.1 is as defined above, by a conventional method, followed by coupling with an aniline of the following formula (VI): ##STR22## wherein X.sup.5, Y.sup.2 and R are as defined above

The monoazo dye of the formula (I-4) is prepared, for example, by diazotizing an amine of the following formula (VII): ##STR23## wherein P, Q.sup.2 and T are as defined above, by a conventional method, followed by coupling with an aniline of the following formula (VIII): ##STR24## wherein X.sup.5, Y.sup.3 and R are as defined above

Textile materials to which the monoazo dye of the present invention is applicable, include polyester fibers made of polyethylene terephthalate, polybutylene terephthalate or a polycondensate of terephthalic acid and 1,4-bis-(hydroxymethyl)cyclohexane, polyamide fibers made of nylon and the like, and fiber blend products such as blended yarn fabrics and union cloths comprising natural fibers such as cotton, silk and wool fibers and the above mentioned polyester fibers.

Particularly, among polyester fibers, not only ordinary polyester fibers (regular denier fibers) but also microfibers (fine denier fibers, which are less than 1 d) and ultramicro fibers (which are less than 0.3 d) may be mentioned as fibers which can successfully be dyed with the monoazo dye of the present invention.

When the monoazo dye of the present invention is used in dyeing, the monoazo dye of the formula (I) is dispersed in an aqueous medium by means of a dispersing agent in the usual way to prepare a dye bath for dyeing or a printing paste for textile printing.

For example, in the case of dyeing, polyester fibers and fiber mixture products such as blended yarn fabrics of union cloth product comprising polyester fibers can be dyed with good color fastness by common dyeing methods, such as a high temperature dyeing method, a carrier dyeing method and a thermosol dyeing method. In some cases, the addition of an acidic substance to the dyeing bath may result in more successful dyeing.

Dyed products obtained by dyeing or textile printing with the monoazo dye of the present invention are excellent in not only color fastness to washing but also various color fastnesses such as color fastnesses to perspiration (alkali), to sublimation and to water. Further, even if the dyed produces are further processed, no substantial decrease in the wet color fastness occurs.

The monoazo dye of the present invention may be used in combination with similar or other types of dyes.

Now, the present invention will be described in further detail with reference to Examples. However, it should be understood that the present invention is by no means restricted by such specific Examples.

EXAMPLE 1

0.025 g of a 1:1 monoazo dye mixture of the monoazo dyes of the following formulae (I-1-3) and (I-1-4): ##STR25## which are covered by the formula (I-1) wherein X.sup.4 is --NHCOCH.sub.3 and R is phenoxy, was dispersed in 200 ml of water containing 0.025 g of a naphthalenesulfonic acid-formaldehyde condensate and 0.025 g of a sulfuric acid ester of a higher alcohol to prepare a dye bath. In the dye bath, 10 g of a union cloth comprising polyester fibers of 2d and 0.01 d was immersed for dyeing at 135.degree. C. for 30 minutes. After the dyeing, the cloth was subjected to soaping, washed with water and dried, whereby a brilliant red well-dyed cloth was obtained with the different denier polyester fibers dyed with the same color and the same color strength. The color fastness to washing of the union cloth-dyed with the dye mixture was as excellent as 4-5 grade.

The color fastness to washing was measured in accordance with the AATCC 2A method and evaluated by the degree of staining on a nylon cloth.

The dye mixture used in this Example was prepared as follows. 4.4 g of a 1:1 mixture of 5,6-dichloroaminobenzothiazole and 6,7-dichloroaminobenzothiazole was dissolved in 80 g of a 50% sulfuric acid aqueous solution at 80.degree. C. and then cooled to 0.degree. C. Then, 6.5 g of a 43% nitrosylsulfuric acid was added to the solution at 0.degree. C. and the solution was stirred for 2 hours to obtain a diazo liquid.

After 9.0 g of N,N-diphenoxycarbonyloxyethyl-m-acetylaminoaniline was dissolved in 200 ml of methanol, the diazo liquid was dropwise added thereto at 0.degree. to 5.degree. C. followed by stirring for 2 hours. The product was collected by filtration, washed with water and dried to obtain the desired dye mixture. The wavelength at the maximum absorption of the dye mixture (.lambda..sup.max : in acetone) was 530 nm.

COMPARATIVE EXAMPLE 1

The compound having the same basic chemical structure as represented by the formula (I-1) wherein X.sup.4 is --NHCOCH.sub.3 and R is ethoxy (dye used in Example 1 in Japanese Unexamined Patent Publication No.255601/1993), was synthesized in accordance with the method in Example 1, and an ultramicro fiber union cloth was dyed therewith. The dyed cloth was evaluated in the same manner as in Example 1. The color fastness to washing of the dyed cloth was as poor as 3 grade.

EXAMPLES 2 TO 25

The dyes shown in Tables 1 and 2 were synthesized, and ultramicro fiber union cloths were dyed therewith. The color fastnesses to washing of the dyed cloths were measured in the same manner as in Example 1. The results are shown in Tables 1 and 2.

TABLE 1__________________________________________________________________________The 1:1 mixture of the dyes of the formulae (I-1-5) and (I-1-6) ##STR26## (I-1-5) ##STR27## (I-1-6) .lambda..sub.max Color (nm; in fastness toExample X.sup.4 R Acetone) washing__________________________________________________________________________2 NHCOCH.sub.3 ##STR28## 543 4-53 NHCOCH.sub.3 ##STR29## 545 4-5 ##STR30## ##STR31## 542 4-55 NHCOC.sub.2 H.sub.5 ##STR32## 542 4-56 NHCOC.sub.3 H.sub.7 (n) ##STR33## 542 4-57 NHCOC.sub.4 H.sub.9 (n) ##STR34## 542 4-58 Cl ##STR35## 504 4-59 CH.sub.3 ##STR36## 526 4-510 H ##STR37## 514 4-5__________________________________________________________________________ TABLE 2__________________________________________________________________________ ##STR38## .lambda..sub.max Color (nm: in fastnessExample X.sup.1 X.sup.2 X.sup.3 X.sup.4 R Acetone) to washing__________________________________________________________________________11 Cl H H NHCOCH.sub.3 ##STR39## 546 4-512 Cl H H NHCOCH.sub.3 ##STR40## 544 4-513 Cl H H NHCOCH.sub.3 ##STR41## 547 4-514 Cl H H Cl ##STR42## 507 4-515 Cl H H H ##STR43## 517 4-516 Cl H H CH.sub.3 ##STR44## 529 4-517 H H H NHCOCH.sub.3 ##STR45## 524 418 H H H Cl ##STR46## 500 419 H H H H ##STR47## 510 420 H H H CH.sub.3 ##STR48## 521 421 H H H ##STR49## ##STR50## 523 4-522 H H H NHCOC.sub.3 H.sub.7 (n) ##STR51## 525 4-523 Cl Cl H NHCOCH.sub.3 ##STR52## 532 4-524 Cl Cl H H ##STR53## 518 4-525 Cl Cl H H ##STR54## 516 4-5__________________________________________________________________________

EXAMPLE 26

0.025 g Of the monoazo dye of the following formula (I-2-1) which corresponds to the formula (I-2) wherein X.sup.4 and Y.sup.1 are hydrogen, and R is phenyl: ##STR55## was dispersed in 200 ml of water containing 0.025 g of a naphthalenesulfonic acid-formaldehyde condensate and 0.025 g of a sulfuric acid ester of a higher alcohol to prepare a dye bath. 10 g of a union cloth comprising polyester fibers of 2 d and 0.01 d was immersed in the dye bath at 135.degree. C. for 30 minutes for dyeing, and then the cloth was subjected to soaping, washed with water and dried, whereby a brilliant red well-dyed cloth was obtained with the different denier fibers dyed with the same color and the same color strength. The color fastness to washing of the union cloth dyed with the dye was as a excellent as 4 to 5 grade.

The color fastness to washing was measured in accordance with the AATCC 2A method and evaluated by the degree of staining on a nylon cloth.

The dye used in this Example was prepared as follows.

10.0 g of 2-amino-6-nitrobenzothiazole was added to a liquid mixture of 45 g of 75% phosphoric acid, 16 g of acetic acid and 8.5 g of sulfuric acid, and 16 g of 43% nitrosylsulfuric acid was dropwise added thereto at -2.degree. C. followed by stirring for 2 hours to obtain a diazo liquid.

After 19.0 g of N,N-diphenylcarbonyloxyethylaniline was dissolved in 800 ml of methanol, the diazo liquid was dropwise added thereto at 0.degree. to 5.degree. C. The mixture was stirred for 2 hours. The product was collected by filtration, washed with water and dried to obtain the desired dye. The wavelength at the maximum absorption of the dye (.lambda..sub.max : in acetone) was 530 nm.

COMPARATIVE EXAMPLE 2

The compound of the formula (I-2) wherein each of X.sup.4 and Y.sup.1 is hydrogen and R is methyl (as disclosed in Japanese Examined Patent Publication No. 16039/1961) was synthesized in accordance with the method in Example 26, and an ultramicro fiber union cloth was dyed therewith and the dyed cloth was evaluated in the same manner as in Example 26. The color fastness to washing of the dyed cloth was as poor as 3 grade.

EXAMPLES 27 TO 41

The dyes shown in Table 3 were synthesized in the same manner as in Example 26. Ultramicro fiber union cloths were dyed therewith, and the color fastness to washing was measured in the same manner as in Example 26.

The results are shown in Table 3.

TABLE 3__________________________________________________________________________ ##STR56## .lambda..sub.max Color (nm; in fastnessExample X.sup.4 Y.sup.1 R Acetone) to washing__________________________________________________________________________27 H H ##STR57## 532 4-528 H H ##STR58## 528 4-529 CH.sub.3 H ##STR59## 542 4-530 CH.sub.3 H ##STR60## 544 4-531 CH.sub.3 H ##STR61## 540 4-532 Cl H ##STR62## 520 4-533 Cl H ##STR63## 518 4-534 H Cl ##STR64## 510 4-535 H Cl ##STR65## 508 4-536 NHCOCH.sub.3 H ##STR66## 550 4-537 NHCOCH.sub.3 H ##STR67## 548 4-538 NHCOCH.sub.3 H ##STR68## 552 4-539 NHCOC.sub.3 H.sub.7 (n) H ##STR69## 550 4-540 NHCOC.sub.3 H.sub.7 (n) OCH.sub.3 ##STR70## 570 4-541 NHCOCH.sub.3 OCH.sub.3 ##STR71## 572 4-5__________________________________________________________________________

EXAMPLE 42 ##STR72##

0.025 g of the monoazo dye of the above formula was dispersed in 200 ml of water containing 0.025 g of a naphthalenesulfuric acid-formaldehyde condensate and 0.025 g of a sulfuric acid ester of a higher alcohol to prepare a dye bath. 10 g of a union cloth comprising polyester fibers of 2 d and 0.01 d was immersed for dyeing at 135.degree. C. for 30 minutes, and then the cloth was subjected to soaping, washed with water and dried, whereby a brilliant blue well-dyed cloth with the different denier fibers dyed in the same color and with the same color strength was obtained. The color fastness to washing of the union cloth dyed with the dye was as excellent as 4.sup.+ grade.

The color fastness to washing was measured by the AATCC 2A method and evaluated by the degree of staining on a nylon cloth.

The monoazo dye used in this Example was prepared as follows.

0.76 g of sodium nitrite was added to 5 g of sulfuric acid, and the resulting mixture was heated to 70.degree. C. and then cooled to 5.degree. C. A mixture of 1.4 g of propionic acid and 8.6 g of acetic acid was gradually added thereto, and the temperature was elevated to 15.degree. C. and maintained at this level. After the solution was cooled to 0.degree. C., 1.7 g of 2-amino-3-cyano-5-nitrothiophene and then 1.4 g of propionic acid and 8.6 g of acetic acid were added to the solution, and the resulting mixture was stirred at 5.degree. C. for 75 minutes. To the mixture, the same amounts of propionic and acetic acid were added, and the mixture was further stirred at 5.degree. C. for one hour.

Urea was added to the mixture to decompose the remaining nitrous acid, and the resulting diazonium salt solution was dropwise added to a solution of 4.5 g of N,N-dibenzoyloxyethylamino-m-acetoanilide in 200 ml of methanol at 0.degree. to 5.degree. C. and the solution was stirred for 2 hours. The desired dye was separated from the solution by filtration, washed with waster and dried.

The wavelength at the maximum absorption of the dye (.lambda..sub.max : in acetone) was 606 nm.

COMPARATIVE EXAMPLE 3

The dye of the following formula: ##STR73## as disclosed in Example 80 in Japanese Examined Patent Publication No. 47214/1982, was evaluated in the same manner as in Example 42, and the color fastness to washing was as poor as 2 to 3 grade.

EXAMPLES 43 TO 74

The dyes shown in Table 4 were synthesized in accordance with the method in Example 42, and ultramicro fiber union cloths were dyed in the same manner as in Example 42.

The color fastness to washing of all the dyes were at least 4.sup.+ grade.

TABLE 4__________________________________________________________________________ ##STR74## .lambda..sub.max Hue of dyedExample Q.sup.1 X.sup.5 Y.sup.2 R (Acetone) cloth__________________________________________________________________________43 CN NHCOC.sub.2 H.sub.5 H ##STR75## 605 moderate blue44 CN NHCOC.sub.4 H.sub.9(n) H ##STR76## 601 moderate blue45 CN NHCOCH.sub.2 OCH.sub.3 H ##STR77## 604 moderate blue46 CN NHCOC.sub.2 H.sub.4 OC.sub.2 H.sub.5 H ##STR78## 604 moderate blue47 CN NHCOCH.sub.3 OCH.sub.3 ##STR79## 642 bluish green48 CN CH.sub.3 H ##STR80## 613 reddish blue49 CN CH.sub.3 H ##STR81## 610 reddish blue50 CN CH.sub.3 H ##STR82## 615 reddish blue51 CN CH.sub.3 OC.sub.2 H.sub.5 ##STR83## 645 bluish green52 CN ##STR84## H ##STR85## 601 moderate blue53 CN NHSO.sub.2 CH.sub.3 H ##STR86## 592 moderate blue54 CN NHSO.sub.2 C.sub.2 H.sub.5 H ##STR87## 589 moderate blue55 CN ##STR88## H ##STR89## 588 moderate blue56 CN NHCOC.sub.3 H.sub.7 (i) H ##STR90## 607 greenish blue57 CN NHCOC.sub.3 H.sub.7 (n) CH.sub.3 ##STR91## 585 dark blue58 CN Cl H ##STR92## 594 reddish blue59 CN Cl H ##STR93## 591 reddish blue60 CN Br H ##STR94## 590 reddish blue61 CN NHCONH.sub.2 H ##STR95## 609 greenish blue62 CN NHCONH.sub.2 H ##STR96## 606 greenish blue63 CN NHCONH.sub.2 H ##STR97## 611 greenish blue64 CN CH.sub.3 H ##STR98## 614 reddish blue65 CN CH.sub.3 CH.sub.3 ##STR99## 595 dark blue66 CN H H ##STR100## 604 reddish blue67 CN H H ##STR101## 601 reddish blue68 CN H OCH.sub.3 ##STR102## 629 moderate blue69 CN CH.sub.3 OCH.sub.3 ##STR103## 639 greenish blue70 ##STR104## CH.sub.3 H ##STR105## 630 reddish blue71 ##STR106## NHCOCH.sub.3 H ##STR107## 598 moderate blue72 ##STR108## NHCOCH.sub.2 OCH.sub.3 H ##STR109## 596 moderate blue73 ##STR110## NHSO.sub.2 C.sub.2 H.sub.5 OCH.sub.3 ##STR111## 624 bluish green74 ##STR112## ##STR113## OCH.sub.3 ##STR114## 636 bluish green__________________________________________________________________________

EXAMPLE 75 ##STR115##

0.025 g of the monoazo dye of the above formula was dispersed in 200 ml of water containing 0.025 g of a naphthalenesulfuric acid-formaldehyde condensate and 0.025 g of a sulfuric acid ester of a higher alcohol to prepare a dye bath. 10 g of a union cloth comprising polyester fibers of 2 d and 0.01 d was immersed for dyeing at 135.degree. C. for 30 minutes, and then the cloth was subjected to soaping, washed with water and dried, whereby a brilliant blue well-dyed cloth with the different denier fibers dyed in the same color and with the same color strength was obtained. The color fastness to washing of the union cloth dyed with the dye was as excellent as 4.sup.+ grade.

The color fastness to washing was measured by the AATCC 2A method and evaluated by the degree of staining on a nylon cloth.

The monoazo dye used in this Example was prepared as follows.

To a mixture of 15 g of glacial acetic acid/propionic acid (3:1) and 5.0 g of 85% sulfuric acid, 1.9 g of 2-amino-3-cyano-4-chloro-5-formylthiophene was added and then 3.2 g of nitrosylsulfuric acid (43%) was dropwise added at 0.degree.0 to 5.degree. C. The resulting solution was stirred at 0.degree. to 5.degree. C. for 4 hours.

Urea was added to the solution to decompose the residual nitrous acid, and the resulting solution was dropwise added to a solution of 4.5 g of N,N-dibenzoyloxyethylamino-m-acetoanilide in 200 ml of methanol at 0.degree. to 5.degree. C. The solution was stirred for 2 hours and filtered to collect the desired dye, and it was washed with water and dried.

The wavelength at the maximum absorption of the dye (.lambda..sub.max : in acetone) was 590 nm.

COMPARATIVE EXAMPLE 4

The dye disclosed in Example 6 in Japanese Unexamined Patent Publication No. 266466/1986 of the following formula: ##STR116## was evaluated in accordance with Example 75. As a result, the color fastness to washing was as poor as 2 to 3 grade.

EXAMPLES 76 TO 95

The dyes shown in Table 5 were synthesized in accordance with the method in Example 75, and ultramicro fiber union cloths were dyed in the same manner as in Example 75. The color fastnesses to washing were at least 4.sup.+.

TABLE 5__________________________________________________________________________ ##STR117## .lambda..sub.max nmExample P Q.sup.2 T X.sup.5 Y.sup.3 R (Acetone) Hue__________________________________________________________________________76 CHO CN Cl NHCOCH.sub.3 H ##STR118## 576 reddish blue77 CHO CN Cl NHCONH.sub.2 H ##STR119## 593 moderate blue78 CHO CN Cl NHCOC.sub.2 H.sub.4 OCH.sub.3 H ##STR120## 592 moderate blue79 CHO CN Cl H H ##STR121## 573 violet80 CHO CN Cl CH.sub.3 H ##STR122## 584 bluish violet81 CHO CN Cl Cl H ##STR123## 569 violet82 CHO CN Cl NHCOCH.sub.3 OCH.sub.3 ##STR124## 622 bluish green83 CHO NO.sub.2 Cl NHSO.sub.2 CH.sub.3 H ##STR125## 546 violet84 CHO CN ##STR126## CH.sub.3 H ##STR127## 582 bluish violet85 CHO CN ##STR128## NHCOCH.sub.3 H ##STR129## 592 moderate blue86 CHO CN Br ##STR130## H ##STR131## 572 bluish violet87 CHO CN SO.sub.2 CH.sub.3 NHCOC.sub.4 H.sub.9 H ##STR132## 601 moderate blue88 NO.sub.2 CN Cl CH.sub.3 H ##STR133## 614 reddish blue89 NO.sub.2 CN Cl NHCOCH.sub.3 H ##STR134## 618 moderate blue90 NO.sub.2 CN Cl NHSO.sub.2 C.sub.2 H.sub.5 OCH.sub.3 ##STR135## 643 bluish green91 NO.sub.2 CN Br NHCOC.sub.2 H.sub.4 OC.sub.2 H.sub.5 H ##STR136## 621 moderate blue92 CN CN Cl CH.sub.3 OC.sub.2 H.sub.5 ##STR137## 639 bluish green93 CN CN CH.sub.3 ##STR138## H ##STR139## 565 violet94 CN CN CH.sub.3 NHCOC.sub.4 H.sub.9 OCH.sub.3 ##STR140## 603 reddish blue95 CN CN CH.sub.3 Br H ##STR141## 539 reddish__________________________________________________________________________ violet

The present invention provides dyes capable of dyeing polyester fibers with excellent color fastnesses to perspiration (alkali), to sublimation and to water. The present invention provides-disperse dyes capable of dyeing polyester ultramicro fibers which are difficult to dye, with red, blue or reddish violet with excellent color fastness.

Claims

1. A monoazo dye of the following formula (I): ##STR142## wherein R is phenyl, phenoxy or benzyl, and D is a group of the formula (D1) or (D2): ##STR143## wherein each of X.sup.1, X.sup.2 and X.sup.3, which are independent of one another, is hydrogen or chlorine, X.sup.4 is hydrogen , chlorine, methyl or --NHCOR.sup.1, wherein R.sup.1 is C.sub.1-4 alkyl or phenyl; ##STR144## wherein X.sup.4 is as defined above, Y.sup.1 is hydrogen, chlorine or C.sub.1-4 alkoxy.

2. The monoazo dye according to claim 1, which is represented by the following formula (I-1): ##STR145## wherein X.sup.1, X.sup.2, X.sup.3, X.sup.4 and R are as defined above.

3. The monoazo dye according to claim 2, which is represented by the following formula (I-1-1): ##STR146## wherein one of X.sup.2-1, and X.sup.3-1 is chlorine, the other is hydrogen, and X.sup.4-1 is acetylamino or benzoylamino.

4. The monoazo dye according to claim 2, which is represented by the following formula (I-1-2): ##STR147##

5. The monoazo dye according to claim 1, which is represented by the following formula (I-2): ##STR148## wherein X.sup.4, Y.sup.1 and R are as defined above.

6. The monoazo dye according to claim 5, wherein X.sup.4 is hydrogen, methyl or C.sub.1-2 alkylcarbonylamino, Y.sup.1 is hydrogen, and R is phenyl.

7. The monoazo dye according to claim 1, which is represented by the following formula (I-2-1): ##STR149##

8. A method for dyeing polyester ultramicro fibers by applying thereto the monoazo dye of claim 1.

9. Polyester ultramicro fibers dyed with the monoazo dye of claim 1.