CA2081512A1

CA2081512A1 - Stable preparation of reactive dyestuffs

Info

Publication number: CA2081512A1
Application number: CA002081512A
Authority: CA
Inventors: Martin Michna
Original assignee: Individual
Current assignee: Bayer AG
Priority date: 1991-10-30
Filing date: 1992-10-27
Publication date: 1993-05-01
Also published as: EP0539825A1; EP0539825B1; JPH05247367A; DE59205396D1; DE4135741A1

Abstract

A b s t r a c t The storage life of reactive dyestuff preparations is extended by pyrophosphoric acid or water-soluble salts thereof.

Le A 28 631-Foreign countries

Description

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, Le A 28 631 - 1 --2 ~ 12 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 Le A 28 631 - 2 -29~12 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 Le A 28 631 - 3 -20~1~12 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.

Le A 28 631 - 4 -2 ~

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, Le A 28 631 - 5 -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.

Le A 28 631 - 6 -2~81~12 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 Le A 28 631 - 7 -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 ~e A 28 631 - 8 -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, Le A 28 631 - 9 -2 0 ~
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) ~ X (2) Le A 28 631 - 10 -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 Le A 28 631 - 11 -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 ~;~N I F
503H H Cl Le A 28 631 - 12 -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 ~ CH~

H ~Cl I N

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.

Le A 28 631 - 13 -Example 3 540 kg of a synthesis solution of the dyestuff of the formula o NH

N
H H

(~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 Le A 28 631 - 14 -2 ~ 2 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 Le A 28 631 - 15 -2 0 ~

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

(~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.

Le A 28 631 - 16 -

Claims

1. A reactive dyestuff preparation containing at least one ractive dystuff and at least one stabiliser, in which the stabiliser present is pyrophosphoric acid or a salt thereof in an amount of 0.1 - 20%
by weight, relative to the preparation.

2. A preparation according to claim 1, in which the stabiliser is present in an amount of 0.5 - 10%, relative to the preparation.

3. A preparation according to claim 1, in which the reactive dyestuff is an azo or anthraquinone reactive dyestuff.

4. A preparation according to claim 1 in which the dyestuff is an o,o'-dihydroxyazo metal complex, formazan or phthalocyanine dyestuff.

5. A preparation according to claim 1, in which the dyestuff contains at least one of the following groups 1-4 as fibre-reactive group (1) (2) Le A 28 631-US - 17 - (3) in which the formulae (1), (2) and (3) the following applies:
X1 = F
X2 = Cl, F, NH2, N(R2)2, OR2, CH2R2, SR2, N(CH2)n, 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, alkyl, substituted alkyl, aryl, substituted aryl, aralkyl, substituted aralkyl or -SO2-CH2-CH2-Z (4) Le A 28 631-US - 18 -in which Z represents Cl, Br, OSO3H, SSO3H, NR2, and R represents substituted or unsubstituted C1-C4-alkyl, the reactive dyestuffs being able to carry one or more identical or different reactive groups in the molecule.

6. A preparation according to claim 1, which is present as a stable aqueous preparation.

7. A preparation according to claim 1, which contains, in addition to the stabiliser, orthophosphates, metaphosphates or borates as buffer substance.

8. A preparation according to claim 6, which contains:
10 - 45% by weight of a water-soluble dyestuff 0.01 - 20, preferably 0.1 - 10, % by weight of a pyrophosphate, 0 - 85, preferably 0 - 30, % by weight of a water-soluble organic solubiliser 0 - 3% by weight of a buffer and water (to 100).

Le A 28 631-US - 19 -

9. A process for producing a preparation according to claim 1, in which before the addition of the pyro-phosphate it is subjected to pressure permeation.

10. A process for the dyeing of cellulose or polyamides with a dyestuff preparation, in which a dyestuff preparation according to claim 1 is used.

Le A 28 631-US - 20 -