Water-soluble blue dye mixture and dyeing method: anthraquinone reactive dye and formazan reactive dye

A water-soluble dye mixture comprising a blue anthraquinone reactive dye represented in its free acid form by the formula: ##STR1## wherein X is --CH.dbd.CH.sub.2 or --C.sub.2 H.sub.4 W wherein W is a group removable by action of alkali and from 0.2 to 5 times by weight to said anthraquinone reactive dye of a blue formazan reactive dye represented in its free acid form by the formula: ##STR2## wherein R is a hydrogen atom or a C.sub.1 -C.sub.4 alkyl group, Y is a halogen atom, --NHC.sub.2 H.sub.4 SO.sub.3 H or ##STR3## and X is --CH.dbd.CH.sub.2 or --C.sub.2 H.sub.4 W wherein W is a group removable by action of alkali.

The present invention relates to a water-soluble dye mixture and a dyeing 
method employing the dye mixture. Particularly, it relates to a clear blue 
reactive dye mixture capable of dyeing satisfactorily even at a low salt 
concentration and having excellent build up properties and a dyeing method 
employing such a mixture. 
Water-soluble reactive dyes for dyeing cellulose-containing fibers are 
required to be excellent in various dyeing properties. In the case of blue 
dyes, anthraquinone dyes are generally known to be clear and excellent in 
build up properties. However, when an anthraquinone dye is used for 
dyeing, it is usually required to maintain the salt concentration in the 
dye bath at a relatively high level, and there has been an additional 
problem that the dyeing properties vary depending upon the dyeing 
temperature. 
In order to lessen such problems of anthraquinone dyes, it is conceivable 
to use them in combination with other type of dyes which are excellent in 
the temperature dependency at the time of dyeing and which are capable of 
dyeing satisfactorily at a low salt concentration. However, if other types 
of dyes are mixed with anthraquinone dyes, the excellent properties of 
anthraquinone dyes such as clearness and build up properties tend to 
deteriorate although the above problems may be lessened. From the 
practical point of view, the clearness may be sacrificed to some extent, 
but it is untenable to sacrifice the build up properties, since the merit 
of using anthraquinone dyes will thereby be lost. 
Under these circumstances, the present inventors have conducted extensive 
researches with an object to obtain a dye mixture whereby the temperature 
dependency is improved without impairing the excellent build up properties 
of an anthraquinone dye and which is capable of dyeing satisfactorily at a 
low salt concentration. As a result, it has been found possible to 
accomplish the object by incorporating a predetermined amount of a 
formazan dye having a certain specific structure to an anthraquinone dye 
having a certain specific structure. The present invention has been 
accomplished on the basis of this discovery. 
The present invention provides a water-soluble dye mixture comprising a 
blue anthraquinone reactive dye represented in its free acid form by the 
formula: 
##STR4## 
wherein X is --CH.dbd.CH.sub.2 or --C.sub.2 H.sub.4 W wherein W is a group 
removable by action of alkali and from 0.2 to 5 times by weight to said 
anthraquinone reactive dye of a blue formazan reactive dye represented in 
its free acid form by the formula: 
##STR5## 
wherein R is a hydrogen atom or a C.sub.1 -C.sub.4 alkyl group, Y is a 
halogen atom, --NHC.sub.2 H.sub.4 SO.sub.3 H or 
##STR6## 
and X is --CH.dbd.CH.sub.2 or --C.sub.2 H.sub.4 W wherein W is a group 
removable by action of alkali. 
Further, the present invention provides a dyeing method wherein the above 
water-soluble dye mixture is employed. 
Now, the present invention will be described in detail with reference to 
the preferred embodiments. 
The dye represented by the formula (A) is known as C.I. Reactive Blue 19. 
Whereas, the dye represented by the formula (B) is disclosed either 
specifically or by a general formula in Japanese Unexamined Patent 
Publication No. 15451/1984 or Japanese Examined Patent Publication No. 
18357/1985 or No. 17457/1985. For example, Japanese Unexamined Patent 
Publication No. 15451/1984 discloses a dye represented in its free acid 
form by the formula: 
##STR7## 
Likewise, Japanese Examined Patent Publication No. 18357/1985 discloses a 
dye represented by the formula: 
##STR8## 
The present invention is characterized in that among various known blue 
reactive dyes, the specific anthraquinone reactive dye of the formula (A) 
and the specific copper formazan reactive dye of the formula (B) are 
combined. 
In the formulas (A) and (B) in the present invention, the group of W 
removable by action of alkali may usually be --OSO.sub.3 H, --SSO.sub.3 H, 
--OPO.sub.3 H.sub.2, --OCOCH.sub.3 or a halogen atom. Among them, 
--OSO.sub.3 H is most typical. 
The C.sub.1 -C.sub.4 alkyl group for R includes a methyl group, an ethyl 
group, a n-propyl group, an i-propyl group and a n-butyl group. 
Y is a halogen atom, --NHC.sub.2 H.sub.4 SO.sub.3 H or 
##STR9## 
Among them, the halogen atom or --NHC.sub.2 H.sub.4 SO.sub.3 H is 
preferred. 
In the above formulas (A) and (B), the group of the formula --SO.sub.2 X is 
preferably attached to the p- or m-position to the amino group i.e. --NH-- 
in the formula (A) or 
##STR10## 
in the formula (B). Otherwise, it is possible to employ a mixture 
comprising a dye wherein --SO.sub.2 X is attached to the p-position to the 
amino group and a dye wherein --SO.sub.2 X is attached to the m-position 
to the amino group. In such a case, the mixture preferably comprises from 
65 to 100% by weight of the dye wherein --SO.sub.2 X is attached to the 
m-position and from 0 to 35% by weight of the dye wherein --SO.sub.2 X is 
attached to the p-position. 
In the present invention, the halogen atom includes a chlorine atom, a 
fluorine atom and a bromine atom. 
Among formazan reactive dyes represented by the formula B, particularly 
preferred is a dye represented in its free acid form by the following 
formula (B-1) or (B-2): 
##STR11## 
wherein X is as above with respect to the formula (B). 
In the present invention, each of the water-soluble reactive dyes is 
available in the form of its free acid or its salt. As the salt, an alkali 
metal salt or an alkaline earth metal salt such as a lithium salt, a 
sodium salt, a potassium salt or a calcium salt is preferred. 
The water-soluble reactive dyes represented by the formulas (A) and (B) can 
be prepared by known methods, and there is no particular restriction as to 
the methods for their preparation. 
In the present invention, it is essential to incorporate the formazan 
reactive dye of the formula (B) to the anthraquinone reactive dye of the 
formula (A). The amount of the formazan reactive dye to be incorporated is 
from 0.2 to 5 times, preferably from 0.4 to 2 times, by weight relative to 
the anthraquinone reactive dye. If the amount of the formazan reactive dye 
is too small or too large, it is hardly possible to obtain the effects 
intended by the present invention. In the present invention, the two 
reactive dyes may already be mixed or may be mixed at the time of dyeing 
operation. 
As described in the foregoing, the present invention provides a 
water-soluble dye mixture of blue dyes of the formulas (A) and (B). When 
the water-soluble dye mixture of the present invention is actually used, a 
yellow component and/or a red component may be incorporated, as the case 
requires, in order to obtain a desired color. There is no particular 
restriction as to such yellow and red components. However, it is 
particularly preferred to use as the yellow component a reactive dye 
represented in its free acid form by the formula (I) or (II): 
##STR12## 
wherein Z is --CH.dbd.CH.sub.2 or --C.sub.2 H.sub.4 OSO.sub.3 H, 
##STR13## 
wherein V is --NHCONH.sub.2 or --NHCOCH.sub.3, and Z is --CH.dbd.CH.sub.2 
or --C.sub.2 H.sub.4 OSO.sub.3 H, and as the red component a reactive dye 
represented in its free acid from by the formula (III): 
##STR14## 
wherein U is a hydrogen atom, a methyl group or an ethyl group, T is a 
hydrogen atom, a chlorine atom or a bromine atom, and Z is 
--CH.dbd.CH.sub.2 or --C.sub.2 H.sub.4 OSO.sub.3 H, whereby the dyeing 
rates of the respective dyes agree to one another, and the reproducibility 
of dyeing will be good. 
Fibers which may be dyed by the dye mixture of the present invention 
include cellulose fibers such as cotton, viscose rayon, cuprammonium rayon 
and hemp, and nitrogen-containing fibers such as polyamide, wool and silk. 
Cellulose fibers are particularly preferred. These fibers may be used in 
combination with e.g. polyester, triacetate or polyacrylonitrile as mixed 
fibers. 
The dye mixture of the present invention may be applied to various 
conventional dyeing processes. It is particularly suitable for use in an 
exhaustion dyeing process. However, it is also effective when used in a 
cold pad-batch process or a pad-steam process. 
The exhaustion dyeing of cellulose-containing fibers with a water-soluble 
dye mixture of the present invention can be conducted in the presence of 
alkali such as sodium bicarbonate, sodium carbonate, lithium carbonate or 
sodium hydroxide and an inorganic salt such as Glauber's salt or sodium 
chloride. The alkali is used usually in an amount of from 10 to 30 g per 
liter of the dye bath. The inorganic salt may be used in a large amount of 
50 g or more per liter of the dye bath. However, in the present invention, 
adequate dyeing can be attained with a small amount at a level of from 5 
to 40 g/liter. The temperature for dyeing is usually from 40.degree. to 
80.degree. C., preferably from 40.degree. to 60.degree. C. 
The water-soluble dye mixture of the present invention comprising the 
specific blue anthraquinone reactive dye and the specific blue formazan 
reactive dye in the specific proportions is an excellent dye having small 
temperature dependency and salt concentration dependency and being capable 
of dyeing clearly even at a low salt concentration without impairing 
excellent build up properties of the anthraquinone reactive dye.

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 
0.2 g of a dye mixture comprising 40 parts by weight of an anthraquinone 
reactive dye represented in its free acid form by the formula: 
##STR15## 
and 60 parts by weight of formazan reactive dye represented in its free 
acid form by the formula: 
##STR16## 
was dissolved in 200 ml of water. To this solution, 10 g of Glauber's salt 
was added and dissolved to obtain a dye bath (Glauber's salt 
concentration: 50 g/liter). In this dye bath, 10 g of a non-mercerized 
cotton knitted fabric was immersed, and the bath was heated to 60.degree. 
C. over a period of 30 minutes. Then, 3 g of sodium carbonate was added 
thereto, and exhaustion dyeing was conducted at the same temperature for 
one hour. After dyeing, the dyed fabric was subjected to washing with 
water, soaping and drying in accordance with usual methods, to obtain a 
blue-dyed fabric. 
With respect to this dyed fabric, clearness was evaluated, and the degree 
of exhaustion was obtained from the surface reflectance of the dyed fabric 
as measured by a color-difference meter (manufactured by Nippon Denshoku 
Kogyo K.K.). 
Further, in order to determine the salt concentration dependency, the 
temperature dependency and the build up properties of the dye mixture of 
this Example during the dyeing operation, dyeing was conducted in the same 
manner as above by changing (1) the Glauber's salt concentration of the 
dye bath to 10 g/liter, (2) the dyeing temperature to 50.degree. C. or (3) 
the amount of the dye mixture used to 0.8 g. 
On the basis of the respective results, the salt concentration dependency 
was represented by the percentage of the dyed color density at the 
Glauber's salt concentration of 10 g/liter to the dyed color density at 
the Glauber's salt concentration of 50 g/liter. 
For the temperature dependency, the dyed color density at a dyeing 
temperature of 50.degree. C. relative to the dyed color density at a 
dyeing temperature of 60.degree. C. is obtained, and the temperature 
dependency was represented by the percentage thereof to the dyed color 
density in the case of the formazan reactive dye used alone (Comparative 
Example 2) which is excellent in the temperature dependency. 
Further, for the build up properties, the dyed color density when 0.8 g of 
the dye mixture was used relative to the dyed color density when 0.2 g of 
the dye mixture was used, was obtained and the build up properties were 
represented by the percentage thereof to the dyed color density in the 
case where the anthraquinone reactive dye was used alone (Comparative 
Example 1) which is excellent in the build up properties. 
These results are shown in Table 1. 
EXAMPLE 2 and COMATIVE EXAMPLES 1 to 2 
The tests were conducted in the same manner as in Example 1 except that the 
proportions of the dyes in the dye mixture were changed as shown in Table 
1. 
TABLE 1 
__________________________________________________________________________ 
Proportions of Salt 
dyes in the concentration 
Temperature*.sup.1 
mixture (by weight) dependency 
dependency 
dyedyequinoneFormazanAnthra- 
Clearness 
(%)exhaustionDegree of 
##STR17## 
##STR18## 
propertiesBuild 
__________________________________________________________________________ 
up*.sup.2 
Example 1 
40 60 Good 73 60 100 105 
Example 2 
50 50 Good 74 57 95 110 
Comparative 
100 0 Very good 
74 30 85 100 
Example 1 
Comparative 
0 100 Slightly 
73 80 100 80 
Example 2 inferior 
__________________________________________________________________________ 
*.sup.1 The temperature dependency was represented by a relative value 
based on the value of Comparative Example 2 being 100. 
*.sup.2 The build up properties are represented by a relative value based 
on the value of Comparative Example 1 being 100. 
EXAMPLE 3 
The test was conducted in the same manner as in Example 1 except that the 
formazan reactive dye was changed to the one represented in its free acid 
form by the following formula: 
##STR19## 
whereby clearness was very good, the degree of exhaustion was 75%, the 
salt concentration dependency was 61, the temperature dependency was 100, 
and the build up properties were 110. 
EXAMPLE 4 
The test was conducted in the same manner as in Example 1 except that the 
composition of 40 parts by weight of the anthraquinone reactive dye was 
changed to a mixture comprising 70% by weight of an anthraquinone reactive 
dye represented in its free acid form by the formula: 
##STR20## 
and 30% by weight of an anthraquinone reactive dye represented in its free 
acid form by the formula: 
##STR21## 
whereby clearness was very good, the degree of exhaustion was 70%, the 
salt concentration dependency was 58%, the temperature dependency was 98, 
and the build up properties were 103. 
EXAMPLE 5 
The tests were conducted in the same manner as in Example 1 except that the 
formazan reactive dye was changed to formazan reactive dyes disclosed in 
Table 2 (each represented by the free acid form), whereby clearness was 
very good, and the salt concentration dependency, temperature dependency 
and build up properties were good in every case. 
TABLE 2 
__________________________________________________________________________ 
##STR22## 
No. 
Y 
##STR23## 
##STR24## 
__________________________________________________________________________ 
5-1 Cl 
##STR25## 
##STR26## 
5-2 Cl " " 
5-3 F 
##STR27## 
" 
5-4 
##STR28## 
##STR29## 
" 
5-5 F 
##STR30## 
##STR31## 
5-6 Br 
##STR32## 
##STR33## 
__________________________________________________________________________ 
EXAMPLE 6 
0.2 g of a dye mixture comprising 50 parts by weight of an anthraquinone 
reactive dye represented in its free acid form by the formula: 
##STR34## 
and 50 parts by weight of a formazan reactive dye represented in its free 
acid form by the formula: 
##STR35## 
as the blue component, 0.2 g of a monoazo reactive dye represented in its 
free acid form by the formula: 
##STR36## 
as the yellow component, and 0.2 g of a monoazo reactive dye represented 
in its free acid form by the formula: 
##STR37## 
as the red component, were dissolved in 200 ml of water. To this solution, 
10 g of Glauber's salt was added and dissolved to obtain a dye bath 
(Glauber's salt concentration: 50 g/liter). In this dye bath, 10 g of a 
non-mercerized cotton knitted fabric is immersed, and the bath was heated 
to 60.degree. C. over a period of 30 minutes. Then, 3 g of sodium 
carbonate was added thereto, and exhaustion dyeing was conducted at the 
same temperature for 10 minutes, 20 minutes, 40 minutes or one hour. 
After dyeing, the dyed fabric was subjected to washing with water, soaping 
and drying in accordance with usual methods to obtain a brown-dyed fabric. 
The four brown fabrics thus obtained had similar hue, and it was found that 
the dyeing rates of the yellow reactive dye, the red reactive dye and the 
blue reactive dye were constant and uniform, and their combination is 
particularly excellent in the reproducibility. 
EXAMPLE 7 
The tests were conducted in the same manner as in Example 6 except that the 
blue component was changed to a dye mixture comprising 50 parts by weight 
of an anthraquinone reactive dye represented in its free acid form by the 
formula: 
##STR38## 
and 50 parts by weight of a formazan reactive dye represented in its free 
acid form by the formula: 
##STR39## 
the yellow component was changed to a monoazo reactive dye represented in 
its free acid form by the formula: 
##STR40## 
and the red component was changed to a monoazo reactive dye represented in 
its free acid form by the formula: 
##STR41## 
whereby the dyeing rates of the blue, yellow and red dyes were constant 
and uniform.