STABLE MODIFICATION OF A DISAZO DYESTUFF

MODIFICATION PERMANENTE D'UNE TEINTURE DE TYPE DISAZO

English Abstract

STABLE MODIFICATION OF A DISAZO DYESTUFF
Abstract of the disclosure:
The modification ? being stable under dyeing conditions
of the dyestuff of the formula
<IMG>
characterized by an X-ray diffraction diagram with the charac-
teristic reflexes at the following glance angles a (Figure 3):
angle 0 4.0° 5.0° 8.15° 12.7° 13.5°
intensity 0.31 0.38 1.00 0.92 0.63
said modification allowing dyeings being fast to rubbing ob-
tained on textile wound packages of synthetic and semi-synthetic
fibrous materials.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. The modification ? being stable under dyeing conditions of the dye-
stuff of the formula
<IMG>
characterized by an X-ray diffraction diagram with the characteristic reflexes
at the following glance angles .theta.
angle .theta. 4.0° 5.0° 8.15° 12.7° 13.5°
intensity 0.31 0.38 1.00 0.92 0.63
2. Process for the preparation of the modification ? being stable under
dyeing conditions of the dyestuff of the formula (1)
<IMG>
being characterized by the X-ray diffraction diagram as defined in claim 1,
wherein the dyestuff of formula (1) being unstable under dyeing conditions
(modification .alpha.) and being characterized by an X-ray diffraction diagram
with the characteristic reflexes at the following glance angles
Glance 6.5° 7.0° 7.6° 7.9° 9.1° 10.65° 11.8° 12.95°
angle
Intensity 0.80 0.50 0.40 0.82 0.45 0.35 0.39 1.00
is (a) heated in an aqueous suspension at a temperature of from 50° to 95°C,
or (b) heated in a mixture of water and an organic solvent miscible with
water at a temperature of from 50 to 95°C, or (c) converted into an alkali
metal salt, and the phenol form of the dyestuff is again set free therefrom
by adding an acid.

3. The process as claimed in claim 2a, wherein the heating is per-
formed in the presence of a surface active agent.
4. The process as claimed in claim 2b, wherein the heating is carried
out in the presence of acetic acid, methanol, ethanol, n-propanol, iso-
propanol, n-butanol, iso-butanol, glycol, methylglycol, ethylglycol, ethylene-
glycol, acetone, dioxan, N-methyl-pyrrolidone or dimethyl formamide or mix-
tures thereof as organic solvents.
11

Description

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The prcsent invelrLion relates to a modification of a dis-
azo dyestuIf which is stable under the usual dye~ng condition.s.
The known ~-modification of the dyestuff of the formula
( 1 )
OCH~
o2N ~ _ N = N ~ N - N - ~ OT~
is obtained from the dyestuff prepared according to French
Patent Specificati.on No. 1,300,806, Example 2. That modifica-
tion has the considerable disadvantage that dyeing composition
prepared therefrom in the usual manner by grinding it with
dispersing agents undergo alteration during the dyeing process.
When dyein~ textile wound packages of synthetic or semisynthe-
tic fibrous, for example cross-wound bobbins, this alteration
results in dyestuff deposits on the surface of the material to
be dyed. Such dyestuff deposits are undesirable since they im-
part a specky appearance to the material. to be dyed and the
dyestuff deposited on the surface of the material is chafed
o~f.
The same disadvantages are also inherent in the B-modi-
fication of the said dyestuff, which can be obtained, for exam-
ple by heating the ~-modification to 135C for 4 hours.
The said ~-ana B-modifications are characterized by their
X-ray diffraction spectra. The following tables show their ~-
ray counter tube diagrams (taken by means of a diffractometer
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manuLactured by ~lessrs. ~IILlPS, P~ 1050/30, using Cu-~rays).
The figure given under the heading "Intensity" refers to the
height of the signal as compared with the maximum of the spec-
trum, to which the figure 1.00 has been attributed.
The accompanying drawings show the X-ray diffraction spec-
tra of the dyestuff of formula t1):
Figure 1 - ~-modification; Figure 2 - ~-modification; Figure 3-
~-modification.
Spectrum of the CC-modification
Glance
angle 0 6.5 7.0 7.6 7.9 9.1 10.65 11.8 12.55
Intensity 0. ao o . so o . 40 0.82 0.45 0.35 0.39 1.00
Spectrum of the ~-modification
Glance
angle 0 5 7 6 4 7 4 8 35 8 85 13 0 14 5
Intensity 0.45 0.26 0.29 0.76 0.47 1.00 0.24
Spectrum of the ~-modification
Glance
angle 0 4.0 5.0 8.15 12.7 13.5
Intensity 0.31 0.38 1.00 0.92 0.63
The ~C-modification has been known and pertains to the
state of the art.
The present invention now provides a new crystal modfi-
cation ( ~-modification)of the dyestuff of the above-cited for-
mula (1), which is stable under the dyeing conditions and which
is characterized by the X-ra~ diffraction diagram as shown in
Fig. 3 with the typical reflexes at the following glance angles
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angle ~ 4.0 5.0 8.15 12.7 13.5
Intensity 0.31 0.38 1.00 0.92 0.63
as well as a process for its preparation.
The X-ray counter tube diagram of this new modification is also
disclosed in the preceding Table and has been taken by means of the same
diffractometer as have been theO~-and~-modifications.
Dyestuff compositions prepared with this new ~-modification do no
longer exhibit the above-cited tinctorial disadvantages of the ~-and~ - difi-
cations but rather allow dyeings that are fast to rubbing to be obtained on
textile would packages of synthetic and semisynthetic fibrous material, for
example of polyesters, especially polyethylene-terephthalates, cellulose-2
1/2-acetate, cellulose triacetate, polyamide, mixtures of plyester and wool,
of polyester and spun rayon and of polyester and cottom.
The new ~-modification of the disazo dyestuff in question may be
prepared as follows: the modification of the dyestuff of formula (1) which
is unstable under dyeing conditions ~o~-modification) and which is characteriz-
ed by the X-ray diffraction spectrum as shown in Figure 1, with the typical
reflexes at the following glance angles~
Glance 6.5 7.0 ~.6 7.9 9.1 10.65 11.8 12.95angle
Intensity 0.80 0.50 0.40 0.82 0.45 0.35 0.39 1.00
is (a) heated in an aqueous suspension at a temperature of from 50 to 95C,
or (b) heated in a mixture of water and an organic solvent miscible with
water at a temperature of from 50 to 95C, or (c) converted into an alkali
metal salt, preferably sodium salt, and the phenol form of the dyestuff is
again set free therefrom by adding an acid.
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Accordillg to Ihe above-said process (a), heating may ke
performeA in thc presence of surfactants. Sultable are anionic,
cationic and nonicnic surface-active compounds, for example
the sodium salt of dodecylphenyl-sulfonic acid or of diiso-
butyl-naphthalene-sulfonic acid, the addition product of 25
mols of ethylene oxide on 1 mol of stearyl alcohol, a mixture
of alkyl-dimethylbenzyl-ammonium chlorides, a fatty acid poly-
glycol ester or a tertiary organic phosphoric acid ester of the
addition product of 2 mols of ethylene oxide on 1 mol of laur
alcohol.
Of the organic solvents miscible with water, which may be
used for the said process (b), there may be used, for example,
acetic acid, alcohols, such as, for instance, methanol, etha-
nol, n-propanol, isopropanol, n-butanol, isobutanol, glycol,
methyl-glycol, ethyl-glycol, ethylene-diglycol, acetone, dioxan,
N-methyl-pyrrolidone and dimethylformamide, Mixtures of the
afore-mentioned organic solvents may also be used.
The phenol form of the dyestuff may be set free from the
- alkali metal salt according to process (c) either with inorga-
nic or with organic acids, for example with carbonic acid, ace-
tic acid, hydrochloric acid, sulfuric acid or phosphoric acid.
Process (a) may be combined with the preparation of the
disazo dyestuff of formula (1) by heating the resulting "coup-
ling liquor" after the coupling reaction
( 2 ~ N=N ~ NH2 ~3 ~ H)
is complete, without isolating the disazo dyestuff formed.
The following Examples illustrate the invention, the

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parts and percentages being by weight unless stated other-
wise.
E X A M P L E 1:
300 Parts of the ~-modification of the dyestuff of the
above-cited formula were introduced with stirring into 5,000
parts of a 1% sodium hydroxide solution of 90C. Stirring was
continued for 15 minutes at 90C, whereupon the dyestuff was
converted into its sodium salt. The dyestuff was then preci-
pitated again by introducing carbon dioxide. Stirring was con-
tinued for 30 minutes without heating further, the dyestuff
was suction-filtered and washed until free of ai~ali. The dye-
stuff was obtained in the ~-modification. Dyestuff compositions
that had been prepared therefrom by means of dispersing agents,
for example sodium salt of lignin-sulfonic acid, provided dyeing
liquors having good rheological properties.
E X A M P L E 2:
300 Parts of the ~-modification of the dyestuff of the
above-cited formula were introduced into 5,000 parts of 10%
~ acetic acid. The mixture was refluxed for 6 hours. The dye-
stuff was suction-filtered and washed until free of acid. The
dyestuff was obtained in the ~-modification. Dyestuff composi-
tions that had ~een prepared therefrom in the usual manner by
grinding it with dispersing agents provided dyeing liquors
having good rheological properties.
E X A M P L E 3:
200 Parts of the ~-modification of the dyestuff of the
above-cited formula were refluxed for 6 hours in a mixture of
2,000 parts by volume of water and 2,000 parts by volume of
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methanol. The mixture was allowed to cool, and the dyestuff was
suction-filtered ~o yield the r-modilication.
E X A M P L E 4:
230 Parts of 3-methoxy-4-amino-4'-azo benzen~ were dia-
zotized in 1,200 parts by volume of 15% hydrochloric acid with
147 parts of a 40% sodium nitrite solution. The resulting dia-
zonium salt solution was added within 30 minutes to a solution
of 90 parts of phenol and 130 parts of crystallized sodium
acetate in 4,000 parts by volume of water at about 0 to 5C.
During the addition of the diazonium salt solution, ahout ~00
parts of a 33% sodium hydroxide solution were then added so as
to maintain a pH of 5 to 6. The temperature was maintained at
S to 10C by adding ice from time to time. Stirring was con-
tinued for 1 hour, and the temperature was then raised to 85 -
90C. At this temperature, stirring was continued for 8 to 12
hours. The dyestuff was then suction-filtered in the form o
the ~-modification. The resulting filter cake was washed until
free of salt. This dyestuff was used to prepare dyestuff com-
~ positions that provided dyeing liquors having good rheological
properties.
E X A M P L E 5:
300 parts of the OC-modification of the dyestuff of the
above-cited formuIa were introduced into 5,0Q0 parts of a 1~
sodium hydroxide solution of 90C, and the mixture was stirred
for 15 mlnutes at 90C. The dyestuff was then precip.itated by
adding 50% acetic acid dropwise until a p~l of 8.7 had been rea-
ched. Stirring was continued for 30 minu~es without heating,
and the dyestuff was suction-filtered in the form o~ the ~`'

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modification. It was washed with about 4,000 parts by volume
of water and used to prepare dyestuff compositions that pro-
vided dyeing liquors having good rheological properties.
E X A M P L E 6:
300 Parts of the ~ -modification of the dyestuff of the
formula cited further above were introduced into 4,000 parts
of water of 90C. Then, 20 parts of sodium dodecyl-phenyl-
sulfonate were added. The mixture was stirred for 20 hours at
90C. Then dyestuff was then suction-filtered in the form of
- 10 the ~-modification ànd washed. The resulting dyestuff was
used to prepare dyestuff compositions that provided dyeing
liquors with good rheological properties.
E X A M P L E i:
The dyestuff was prepared as in Example 1 except that the
dyestuff was precipitated by adding hydrochloric acid dropwise
instead of introducing carbon dioxide, until the dyestuff was
again obtained in the ~-modification.
Dyestuff compositions containing the ~-modification of the
dyestuff of the above-mer.tioned formula prepared according to
Examples 1 to 7 were suitable for the unobjectionable dyeing
of wound packages, for example of polyester fibers, such as
polyethylene terephthalate fibers, polyamide fibers and mix-
tures of polyester fibers and wool or polyester fibers and
spun rayon.
E X A M P L E 8:
100 Parts of the ~-modification of the dyestuff of the
above-cited formula were stirred for 4 hours at 60C with
300 parts of water and 100 parts of lignin sulfonatc. The
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resulting Inixture was then gLound in a b~ad mi~l. The resul--
ting dyestuff composition contained the dyestuff in its ~-
modification. It provided dyeing liquors having good rheolo~i-
cal properties.
_ 9 _