Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
The present invention relates to preparations of reactive
dyestuffs.
Reactive dyestuffs contain a grouping which i~ capable of
forming a covalent bond with the OH groups of cellulose
or the N~2 or SH groups of natural and synthetic poly-
amides. This results in particularly good wetfastnes~
properties.
However, these grouping can also react with water, which
diminishes the ability of the dyestuffs to react with the
fibre material even before the actual dyeing process, for
example in the synthesis qolution. This result~ in a
decreased dyestuff yield and a higher dyestuff content in
the waste waters of the production or dyeing process.
However, thi~ undesirable reaction can take place not
only in the synthesis solution but also, for example,
during work-up by means of ~pray-dryin~, in water-
containing liquid formulations or in ~he solid s~a~e
wi~h the unavoidable residual moisture. Significan~
losses may occur especially at eleva~ed ~empera~ures and
on extended s~orage periods.
It i8 alrea~y known from EP-A-114,031 and JP-A-55/135,170
to improve the stability of reactive dyestuffs by certain
pho~phate buffers. However, the results obtained are
unsatisfactory. Granulated dyestuff preparations which,
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in addition to a soluble dyestuff, also contain at most
50 % of a salt dissociating in water, such as, for
example, pyrophosphate, are already known from
DE-A-1,794,173. The dissociating salt is obviously
contained in the preparation in order to allow granula-
tion and thus increase wettability and solubility in
water.
The present invention relates to preparations of reactive
dyestuffs, in particular for cellulose and natural or
synthetic polyamides, which contain at least one reactive
dyestuff and one stabiliser, characterised in that the
stabiliser present is pyrophosphoric acid or a salt
thereof in an amount of 0.1 - 20 % by weight, relative to
the preparation.
Preference is given to the alkali metal salts or the
alkali metal hydrogen salts, and particular preference is
given to the sodium salts or the sodium hydrogen salts,
such as, for example
ONa ONa OH fH OH
O=f-ONa O=f-ONa O=f-ONa O=f-OH O=f-OH
o o I f O (I)
O=f-ONa O=f-ONa O=f-ONa O=f-OH O=f-OH
ONa - OH OH ONa OH
It is also possible first to use any desired neutrali-
sation ~tage of pyrophosphoric acid and then to produce
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a salt other than that added originally by addition of an
acid or base to the mixture.
The pyrophosphates are used in amounts of, preferably,
0.5 - 10 %, relative to the weight of the preparation.
It is also possible to add conventional buffer sub-
stances, such as, for example, orthophosphates, meta-
phosphates and borates to the preparations according to
the invention.
The stabilising effect of the pyrophosphates goes sub-
stantially beyond the conventional buffer~ showing pure
pH stabilisation. The preparations according to the
invention can be solid or liquid.
The solid preparations can be present as powders or
granules. Apart from pyrophosphate, they can contain
further additives such as are customary for reactive
dyestuffs.
Suitable water-soluble additives for the solid prepar-
ations accordin~ to the invention are inorganic salts,
such as NaCl, Na2SO4, ~N~4)2SO4, polyphosphates, but
preferably non-electrolytes, such as dextrin, sugar,
polyvinylpyrrolidone, polyvinyl alcohol, urea, and
anionic dispersants, ~uch as sulphated primary or secon-
dary aliphatic alcohols having 10 to 18 carbon atoms,
sulphated fatty amide~, sulphated alkyleneoxy adducts,
sulphated, partially esterified polyhydric alcohols, and
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in particular sulphonates, such as long-chain
alkylsulphonates, for example laurylsulphonate, cetyl-
sulphonate, stearylsulphonate, mersolates, sodium dialkyl
sulphosuccinates, such as sodium dioctyl sulphosuccinate,
such as taurides, for example oleylmethyltauride (sodium
salt), alkylarylsulphonates, such as alkylbenzene-
sulphonates having a straight-chain or branched alkyl
chain of 7 to 20 carbon atoms, and mono- and dialkyl-
naphthalenesulphonates, such as nonylbenzenesulphonate,
dodecylbenzenesulphonate and hexadecylbenzenesulphonate,
and 1-iæopropyl-naphthalene-2-sulphonate, diiso-
propylnaphthalenesulphonate, di-n-butyl-naphthalene-
sulphonate,diisobutylnaphthalenesulphonate:condensation
products of naphthalenesulphonic acids with formaldehyde,
such as dinaphthylmethanedisulphonate; then ligno-
sulphonates and oxylignosulphonates.
In addition, oils, such as, for example, mineral oils or
phthalic esters or commercially available dustproofing
agents can be added for dust-binding.
~xamples of further additives which can be present are
preservatives and antifoams.
In order to produce the solid dyestuff preparations
according to the invention, the components are mixed
while dry and milled or the milled components are mixed.
Milling can take place, for example, in a mixer, in a
ball mill, a pinned-disc mill, hammer mill or in an air-
jet mill.
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Another method of production consists in drying an
aqueous dispersion or preferably an aqueous solution of
the components and then, if desired, milling the product
to give a powder. Drying can take place, for example, in
a through-circulation cabinet, by means of a paddle
drier, drum drier, but preferably by spray-drying using
a one- or two-component nozzle or spray disc.
The liquid dyestuff preparations according to the inven-
tion are preferably dyestuff solutions containing the
following components:
10 - 45 % by weight of a water-soluble dyestuff
0.1 - 20, preferably 0.5 - 10, % by weight of a
pyrophosphate
0 - ~5, preferably 0 - 30, % by weight of a water-soluble
organic solvent
0 - 3 % by weight of a buffer and water (to 100).
Suitable water-soluble organic solubilisers for reactive
dyestuffs are only those which are incapable of reacting
with the fibre-reactive group. Examples are:
~-caprolactam, N-methylcaprolactam, N-methylpyrrolidone,
~-butyrolactone, dimethylformamide, ethylene carbonate,
polyvinylpyrrolidone, urea, thiourea, dicyandiamide,
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2 ~
dimethyl sulphone, sulpholane and dimethyl sulphoxide.
The liquid dyestuff preparations according to the
invention are produced such that the dyestuff i8 ~tirred
in dry or moist form, for example as a moist press cake,
in water or a mixture of water and water-miscible organic
solubilisers, if necessary dissolved, at slightly
elevated temperature, with the addition of pyrophosphate
and possibly other additives and, if necessary, freed
from undissolved components by filtration. Instead of the
press cake or the dry dyestuff powder, a low-salt con-
centrate, prepared by pres6ure permeation, or mixtureC of
these forms may preferably also be used.
A further method of production for the concentrated
dyestuff solutions according to the invention consists in
adding the pyrophosphates to the solution or suspen~ion
present at the conclusion of the dyestuff synthesis, if
necessary with the addition of water-soluble organic
solubilisers. The solution or suspension obtained after
the synthesis can also be subjected to pressure per-
meation before the addition of pyrophosphate.
If pressure permeation is carried out, it takes placeeither as reverse osmosis, ultra- or nanofiltration or by
a combination of two or more of these methods using
semipermeable membranes.
In reverse 03mosis, membranes are used which are per-
meable only to water molecules but retain salts.
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Ultraf iltration operates with membranes which are per-
meable to molecules having a molecular weight below about
20, 000, but preferably less than 1, 000 Dalton, and to
inorganic salts.
Membranes which can be used for nanofiltration are
permeable to molecules having a molecular weight below
1, 000 Dalton, preferably below about 150 Dalton, and to
monovalent ions; ions of higher valency are largely
retained by these membranes.
For this purpose, it is in principle possible to use
symmetrical, asymmetric and composite membranes having
semipermeable properties. They can be made of organic or
inorganic materials.
Organic material~ are preferred: polyvinylidene fluoride,
cellulose acetate, polytetrafluoroethane, poly-
acrylonitrile, polyethyleneamine, poly-
acrylonitrile/vinylpyrrolidone copolymers, polysulphone,
polyamide, polyhydantoin or else hydrophilised poly
olefins, for example based on polypropylene. Physico-
chemically or chemically modified membranes, such as, for
example , modif ied polyacrylonitrile membranes , ( cf ., f or
example, EP-A-25,973~, which are obtained, for example,
by reacting the base polymer with hydroxylamine, a
polyfunctional, low-molecular-weight compound, a polymer
containing reactive groups and an ionic compound which
can form a chemical bond with the polymer, followed by
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2081 ~12
treatment with active chlorine, for example in the form
of a hypochlorite solution, are also suitable.
Inorganic membranes are those made of porous metal or
metal alloys (so-called metal-sintered membranes, for
example made of porous steel) or those made of porous
carbon, whose surface can be coated, for example, with a
thin zircon dioxide, silica or alumina film, or further-
more those made of porous glass or ceramic.
The process according to the invention is preferably
carried out by subjecting the solutions to pressure
permeation using asymmetric membranes or composite
membranes which are unmodified or modified with ionic
groups, in which, depending on the particular pore size
of the membrane used, salt-containing or salt-free
permeate is discharged.
For pressure permeation in accordance with the process
according to the invention, any commercially available
pressure permeation plants can be used. If some of the
dyestuff has already precipitated or precipitates during
concentration, the plant merely has to be suitable for
pressure permeation of suspensions. Apparatuses of this
type can be designed, for example, as plate, frame,
tubular, wound, hollow fibre or fine hollow fibre modules
in which the membranes described above can be
incorporated.
The reactive dyestuffs according to the invention
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2~81~2
contain, as the water-solubilising group, one or more
COOH or COOe groups, but preferably one or more SO3~ or
SO3~ groups, suitable counterions being Na~, Li~, K~ or
HNR3 where R is subs~i~u~ed or unsubs~i~uted C1-C4-
alkyl.
These reactive dyestuffs are 1:1 or 1:2 metal complex
dyestuffs, such as 1:1 nickel complexes, 1:1 cobalt
complexes, 1:1 copper complexes, 1:1 chromium complexes
or symmetrical or asymmetric 1:2 cobalt complexes or
1:2 chromium complexes or mono-, dis- or polyazo or
azomethine dyestuffs which, as metal-complexing groups,
have o,o'-dioxy-, o-oxy-o'-aminoazo or -azomethine
groups, including tho~e without SO3H groups.
The anionic dyestuffs can belong, for example, to the
phthalocyanine, nitro, di- or triphenylmethane, oxazine,
thiazine, dioxazine, xanthene, but in particular to the
anthraquinone and azo series, such as the monoazo, disazo
or polyazo ~eries. They are deæcribed, for example, in
"Colour Index", 3rd Ed., Vol. 1, p. 1001 to 1562.
Examples of suitable reactive groups are those containing
at least one detachable substituent bound to a hetero-
cyclic radical, including those containing at least one
reactive substituent bound to a 5- or 6-membered hetero-
cyclic ring, such as to a monoazine, diazine, triazine,
for example-pyridine, pyrimidine, pyridazine, thiazine,
oxazine or asymmetric or symmetrical triazine ring or to
a ring system of this type which contains one or more
fu~ed-on rings, such as a quinoline, phthalazine,
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cinnoline, quinazoline, quinoxaline, acridine, phenazine
and phenanthridine ring system; the 5- or 6-membered
heterocyclic rings which contain at least one reactive
substituent are thus preferably those which can contain
one or more nitrogen atoms and fused-on 5- or preferably
6-membered carbocyclic rings.
Of the reactive substituents on the heterocycle, the
following examples may be mentioned: halogen (Cl, Br or
F), azido (N3), thiocyanato, thio, thioether and oxy-
ether.
In the case of the present invention, preference is givento reactive dyestuffs containing reactive groups based on
the following systems: mono- or dihalogeno-symmetrical
triazinyl radicals, mono-, di- or trihalogenopyrimidinyl
radicals or halogen-substituted quinoxalinyicarbonyl
radicals.
Particular preference is given to the following reactive
groups of the formulae (1), (2) and (3)
Xl
NJ~N
~X2 (1)
- IX3
~ X (2)
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2 0 ~ 2
o
Il
-c ~ 4
in which in the formulae (1), (2) and (3) the following
applies:
Xl = F
X2 = Cl, F, NH2, N(R2)2, oR2, CH2R2, SR2, N(CH2)n,
,,(CH2)m
N Q
~(CH2) ~
n = 4, 5, 6
m - 2, 3
Q = NH, NR2, O, S
X3 = Cl, F, CH3
X4 - Cl, F
X5 - Cl, F, H
and in which
R2 is H or alkyl (in particular unsubstituted or O~-,
SO3H- or COOH qubstituted Cl-C4-alkyl), aryl (in par-
ticular unsubstituted or SO3H-, C1-C4-alkyl- or
C1-C4-alkoxy-suhstituted phenyl), aralkyl (in particular
unsubstituted or SO3H-, C1-C4-alkyl- or C1-C4-alkoxy-
substituted benzyl).
Examples of further suitable fibre-reactive groups are
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2 ~ 1 2
those having the formula (4)
-SO2-CH2-CH2-Z ( )
in which
~ represen~s Cl, Br, 0503H, SS03H, NR2,
and
R represents substituted or unsubstituted C1-C4-alkyl.
The reactive dyestuffs can carry one or more identical or
different reactive groups in the molecule.
Both the solid and liquid dyestuff preparations are
suitable for the dyeing and printing of textile sub-
strates and other sheet-like structures. They are distin-
guished by exceptional durability under various storage
conditions and by exceptional stability in the dye bath.
Example 1
96.36 kg of a paste of the dyestuff
503H OH
~;~N I F
503H H Cl
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2 ~
(~maX=490 nm dry content 55~/.) are stirred with 220 kg
of water, 6 kg of sodium pyrophosphate, 39 kg of a
condensation product of naphthalenesulphonic acid with
formaldehyde and 2 kg of mineral oil and dried in a
spray drier to give a dyestuff powder. 94 kg of an
orange powder. 94 kg of an orange powder which has
excellent stabili~y and produces prints and dyeings of
exceptional colour strength are obtainzd.
Example 2
34 kg of a dry powder of the dyestuff of the formula
O NH2
~ CH~
H ~Cl I N
503H F
t~maX = 590 nm) having a pure dyestuff content of 65~/.
are intimately mixed wi~h 37 kg of a lignosulphona~e,
3.1 kg of sodium pyrophosphate and 2 kg of dimethyl
phthalate in a mill, giving a dark dysstuff powder which
is highly suitable for the dyeing and printing of
~extile substrates and, at ~he same time, has
excep~ional stability.
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Example 3
540 kg of a synthesis solution of the dyestuff of the
formula
o NH
S03H 503H
N
H H
S03H
(~max = 635 nm) having a dyestuff content of llX. are
concentrated to a solids content of 26% by mean~ of
pressure permeation using a semipermeable membrane
having a separation limit of 3000 Dalton, and 40 kg of
a condensation product of naphthalenesulphonic acid with
formaldehyde, 3 kg of sodium pyrophosphate and 1 kg of
mineral oil are then added. The mixture is brought to
a pH of 7.9 and converted into a powdery by spray-
drying.
Example 4
160 kg of a moist paste of the dyestuff of the formula
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2 ~ 2
O NH2
S03H
O HN~S02 - CH2 - CH2 - oso3H
~max = 590 nm) having a dry conten~ sf 41% are stirred
in 100 kg of water, and 51.2 kg of a condensa~ion pro-
duct of naphthalenesulphonic acid wi~h formaldehyde,
6 kg of sodium pyrophospha~e and Z kg of butyl phthalate
are added. The suspension is brought ~o a pH of 5.8 and
dried in a commercially available spray drier, giving
about 115 kg of a dark dyes~uff powder which dyes
tex~ile subs~ra~es in blue hues having good fas~ness
proper~ies.
Exam~le 5
220 kg of the synthesis ~olution of the dyestuff
N ~ N
O Nl--N~
ll I ~N-H
50~C~u~ 3~SO ~H
N ~N
[~3
(~max = 610 nm) having a dry conten~ of 9.5X. are first
desal~ed using a
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semipermeable membrane and concentrated to 45 kg.
The pH i8 brought to 7.7, 9.7 kg of a condensation
product of naphthalenesulphonic acid with formaldehyde
and 3.3 kg of sodium pyrophosphate are added, and the
S mixture is dried in a commercially available spray drier
to give a powder having a residual moisture of 4.5 %.
Example 6
200 kg of a paste of the dye~tuff of the formula
o-Cu O SO3H F
HO3S ~ ~ N=W ~ Cl~_~ ~N
~ ~ OH ~ N 1~N~_~F
503H SO3H
(~max = 592 nm) (dry content 41%) are dried with
addi~ion of 2 kg of mineral oil~ 27 kg of a condensa~ion
product of naphthalenesulphonic acid wi~h formaldehyde
ard 4 kg of sodium pyrophosphate in a Paddle-Dryer.
115 kg of a dark powder which dyes cellulose in blue
hues having good fastness properties and which has very
good s~ability are obtained.
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