DE1072338B - Process for the preparation of monoazo dyes and their metal complex compounds - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

kl. 22a

INTEBNAT. KL. C 09 b

PATENT OFFICE

EXPLAINING PUBLICATION 1072 338

S 56729 IVb / 22 a

REGISTRATION DATE: JANUARY 28, 1958

NOTICE THE REGISTRATION AND ISSUE OF THE ACSLE WRITING: DECEMBER 31, 1959

The present invention relates to a process for the preparation of monoazo dyes and their Metal complex compounds, which in the metal-free Form of the general formula

Method of manufacture

of monoazo dyes
and their metal complex compounds

-N = N-B

- N-SO ₉ -N

R,

Applicant:
Sandoz AG _r Basel (Switzerland)

where χ is a substituent capable of metal complication, y is a phenolic or enolic hydroxyl group or a primary or secondary amino group in the ortho position to the - N = N group, η is the number 1 or 2, B is the remainder of an azo component, R is hydrogen or a low molecular weight alkyl or hydroxyalkyl _{radical, R 1} a low molecular weight unsubstituted alkyl radical and R ₃ a low molecular weight unsubstituted alkyl radical or, together with N and R _1, the radical of a saturated heterocyclic amine and in which B and the nucleus A can carry further substituents.

The process for the preparation of the monoazo dyes and their metal complex compounds consists in that one mole of the diazo compound from one in the o-position to the amino group to form a metal complex aminobenzene carrying enabling substituents with 1 mole of a position adjacent to a phenolic or enolic hydroxyl group or coupling to a primary or secondary amino group Azo component combined and the dye obtained, which at least once and at most twice the grouping

-N-SO ₂ -N; '

R ₁

R,

Representative: Dr. W. Schalk, Dipl.-Ing. P. Wirth,

Dipl.-Ing. G. E. M. Dannenberg

and Dr. V. Schmied-Kowarzik, patent attorneys,

Frankfurt / M., Große Eschenheimer Str. 39

Claimed priority:
Switzerland from February 1 and February 22, 1957

Dr. Hans Ruckstuhl, Basel,

and Dr. Walter Wehrli, Riehen (Switzerland),

have been named as inventors

Substituents which the nucleus A by definition can carry, are z. B. to mention: halogen atoms (chlorine,

Bromine), nitro, Acctylamino-, Bcnzoylamino-, carboxy, carbomethoxyamino-Xarbäthoxyamino-.Methyl ^ ethyl, tert-butyl, Metboxy-, sulfonic acid, sulfonamide, Sulfonsäuremethylamid-, Sulfonsäuredimethylamid-, sulfonic acid (Z-hydroxy ) - ethylamide, sulfonic acid di - (2'- hy-

hydroxyethyl) amide, sulfonic acid hydroxypropyl amide, sulfonic acid inethoxypropyl amide, Sulfonic acid phenylamide, sulfonic acid (2'-carboxy) phenylamide, methyl sulfonyl groups as well as a

must have, in which R, R ₁ \ md R _{2 have} the above meanings, treated in substance or on the fiber with a metal donor in such a way that a metal-containing azo dye is formed which contains essentially 1 metal atom complexed to 2 molecules of monoazo compound .

The substituent χ of the diazo component which enables metal complex formation is preferably a hydroxyl, methoxy or carboxy group. Of the R ₁

-N-SO ₉ -N:

-Group,

where R, R ₁ and R _{2 have} the meanings given above.

909 707/282

The azo components are ζ. B. into consideration: hydroxybenzenes, hydroxynaphthalenes, aminonaphthalenes, alkylamino, cycloalkylamino, aralkylamines and Arylaminonaphtlialine, 1 - aryl - 3 - methyl - 5 - pyrazolone, Acylacetylaminoalkanes, acylacetylaminobenzenes and acylacetylaminonaphthalenes. These azo components can carry the same substituents as the diazo components, where as a preferred substituent

- Ν — SO ₂ -N group,

in which R, R ₁ and R _{2 have} the abovementioned meanings, can be used.

The diazotic structure of the aminobenzenes according to the invention is carried out in the usual way at 0 to 5 ° C. the

-N-SO ₂ -Nf group

R,

is resistant to acids and alkalis in the cold.

The coupling of the diazo compounds obtained with those containing a phenolic or enolic hydroxyl group Azo components are advantageously carried out at 0 to 10 ° C. in weakly acidic to weakly alkaline or strongly alkaline medium, optionally in the presence of pyridine, while the coupling with the one primary or secondary amino group-containing azo components at 10 to 20 ° C in a weakly acidic, preferably acetic acid medium is carried out. The resulting monoazo compounds are if necessary, deposited with salt and filtered off.

The conversion of the monoazo dyes into their metal complex compounds preferably takes place with compounds of chromium and cobalt. The metallization is advantageous in aqueous solution or in organic medium, for example in formamide, or in the concentrated aqueous solution of an alkali metal salt of a low molecular weight aliphatic monocarboxylic acid executed. It is advantageous to leave one less than 2 or at least 2 molecules of monoazo dye but an amount of a metal donor containing 1 atom of metal act.

Suitable compounds of chromium are, for. B. Chromifluorid, Chromisulfat, Chromiformiat, Chromiacetat, Potassium chromisulfate or ammonium cliromisulfate. The chromates, e.g. B. sodium or potassium chromate or -bichromate, are ideally suited for the metallization of monoazo dyes. One works here advantageously in a strongly caustic medium, with reducing substances being added if necessary can.

As cobalt compounds z. B. cobalt formate, cobaltoacetate and cobaltosulfate. Will the metallization in the concentrated aqueous solution of an alkali metal salt of a low molecular weight aliphatic monocarboxylic acid made, water-insoluble metal compounds can also be used, for example Cobalt hydroxide and cobalt carbonate.

The metallization is particularly advantageously carried out in an aqueous or alkaline medium, the metal compounds being added in the presence of compounds which keep the metals in a complex bond in a caustic alkaline medium, such as tartaric acid, citric acid and lactic acid.
The metal complex compounds are, if appropriate, after the organic metallization solutions have been poured into water, precipitated from an aqueous medium by adding salt, filtered off, optionally washed and then dried.

The metal-containing azo dyes obtained are uniform metal complex compounds in which 2 molecules of the monoazo compound are essentially bound to 1 atom of metal. The metal complex compounds are so-called 1 ^ complex compounds, in which IMoIekül Monoazo compound with about 0.3 to 0.7 atoms of metal is linked.

The monoazo dyes dye wool, silk, leather and synthetic polyamide fibers after the post-chrome plating or single bath chrome plating process in red, yellow, green, blue, violet, gray or brown shades of good washing, milled and lightfastness.

The metal-containing azo dyes dye wool, silk, leather and synthetic polyamide fibers from neutral or weakly acidic dye bath in red, yellow, green, blue, violet, gray or brown real tones.

If their solubility in organic solvents is sufficiently high, they are also suitable for dyeing of masses dissolved in organic solvents and of paints and plastics for spinning all kinds.

Compared to the next-comparable chromium complexing agents known from US Pat. No. 2,623,871 The chromium complex dyes obtainable according to the invention are distinguished by their excellent acidity Flexing fastness.

In the following examples, the parts are parts by weight, the percentages are percentages by weight, and the Temperatures are given in degrees Celsius.

example 1

18.8 parts of 2-amino-1-hydroxybenzene-4-sulfonic acid amide are diazotized in 100 parts of water with 17 parts of 3O ⁰ Z ₀ IgCr hydrochloric acid and 6.9 parts of sodium nitrite at 5 °.

The diazo compound is neutralized with sodium carbonate and added to a suspension, cooled to 5 °, of 27 parts of 1- (dimethylaminosulfonylamino) -7-hydroxynaphthalene, 200 parts of water and 30 parts of calcium hydroxide. The suspension is stirred overnight, made ^{strongly Congo acidic with 30 0} Z ₀ IgCr hydrochloric acid and the monoazo dye is nitrated. The dye is washed acid-free with water and dried.

The procedure for dyeing is as follows: 2 parts of the above-described monoazo dye and 10 parts of anhydrous sodium sulfate are dissolved in 6000 parts of water at 40 °. 100 parts of wool are added to the dye liquor prepared in this way and the bath is heated to 100 ° in the course of about 30 minutes. After addition of 20 parts of 10 ° / ₀ acetic acid is dyed for 30 minutes at boiling temperature, the bath are 20 parts of 10 ° / ₀ formic acid to and holds it for 30 minutes at 100 °, one from time to time the water evaporated replaced. Then it is 1 part of sodium dichromate as a 10 ° / ₀ aqueous solution to the dye bath and holds the temperature for 30 minutes at 100 °. The re-chromed wool dye is

removed from the dye bath, rinsed with water and dried. It is in an even shade of gray of very good wash, milled and lightfastness dyed.

Example 2

46.5 parts of the monazo dye from Example 1 are dissolved in 450 parts of formamide. This solution is then heated to 90 ° to 100 °, 35 parts of ammonium chromisulfate and 40 parts of crystallized sodium acetate are added over the course of 30 minutes and it is kept at 95 ° for 8 hours. Now, the solution is allowed to cool to room temperature and then diluted with 1000 parts of a 10 ° / ₀ igcn aqueous sodium chloride solution. It is filtered off the precipitated chromium-containing azo dye and wash the filter cake with 10 ° / ₀ sodium chloride solution good. The dried and ground dye is a blue-black powder that dissolves in concentrated sulfuric acid with violet, in hot water with gray-blue color and dyes wool, silk and synthetic polyamide fibers from neutral to slightly acidic baths in wash-, mill- and lightfast bluish-gray tones.

2 parts of the chromium-containing azo dye thus obtained are dissolved in 4000 parts of water at 40 to 50 °. 100 parts of pre-wetted wool are added to this solution and 2 parts of 100 ° / _c acetic acid are added dropwise, whereupon the dyebath is heated to boiling within 30 minutes and held at this temperature for a further 45 minutes. The dyed wool is then removed from the liquor, rinsed with water and dried. A gray dyeing is obtained which has very good fastness to light, washing and milling.

Example 3

23.1 parts of 2-amino-1-hydroxy-4-dimethylaminosulfonylaminobenzene are diazotized with 6.9 parts of sodium nitrite at 0 ° to 5 ° with stirring. The gelbgcfärbte diazo solution is pulverized with 14.6 parts of 2-hydroxynaphthalene and then with as much 30 ° / ₀ sodium hydroxide solution are added, the suspension phenolphthaleinalkalische reaction shows. The mixture is stirred until completion of the coupling reaction, then add sodium chloride are added and by the addition of 30 ° / ₀ hydrochloric acid to a p _H -Wcrt 8.5 to 9 a. The precipitated monoazo compound was filtered off, washed with 20 ° / ₀ sodium chloride solution and dried in vacuo at 80 to 85 °.

For metallization, 39 parts of this monoazo compound are dissolved in 350 parts of formamide. At 95 to 100 ° one puts this solution 8.2 parts Chromiacetat containing 17.5% chromium, and 5.2 parts Chromiformiat containing 27.8 ° / ₀ chromium to and stirred for 3 hours, ie until the metallization terminated , at 95 to 100 °. The cooled solution is diluted with water at 20 ° while stirring; the chromium complex compound which has precipitated out is filtered off, dried in vacuo at 70 ° and ground. A black powder is obtained which dissolves in a hot, dilute sodium carbonate solution with gray-violet color and in concentrated sulfuric acid with a violet color and dyes wool, silk and synthetic polyamide fibers in a neutral to slightly acidic bath in real gray tones.

The 2 - amino -1 - hydroxy - 4 - dimethylaminosulfonylaminobenzene can e.g. B. from 4-acetylamino-1-hydroxybenzene by riveting, cleavage of the acetyl group, acylation with dimethylamidosulfonic acid chloride and Reduction of the nitro group can be produced.

Example 4

30 parts of the monoazo compound metallfreicn of Example 3 are suspended in 900 parts of water at 70 ° and dissolved strength with the required amount of 30 ⁰ / _o sodium hydroxide solution. A cobalt acetate solution of 11 parts of crystallized cobalt acetate is added to this solution at 70 ° to 75 °

[Co (CH ₃ COO) ₂ + 4 H ₂ O]

in 70 parts of water and heated with stirring for 30 minutes at 70 °. The metallization compound is acidified at 50 ° with dilute acetic acid, its sodium dichloride sets to, the precipitated cobalt complex compound is filtered off and dried in vacuo at 70 °. A dark violet-brown powder is obtained, which is dissolved in dilute hot sodium carbonate solution violet color dissolves and wool, silk and synthetic

ao dyes polyamide fibers from weakly acidic bath in real bordeaux tones.

Example 5

24.5 parts of 2-amino-1-hydroxy-4- (N-dimethylaminosulfonyl-N-methyl) aminobenzene are dissolved in ISO parts of water with 20 parts of concentrated hydrochloric acid and diazotized in the usual way at 0 to 5 ° with a concentrated aqueous solution of 6.9 parts of sodium nitrite.

After neutralization with sodium bicarbonate, the diazo compound is converted into a solution cooled to 5 ° 18 parts of 1-phenyl-S-methyl-S-pyrazolone, 4.2 parts of sodium hydroxide and poured 200 parts of water. The precipitated dye becomes after the coupling has ended filtered off and dried.

The isolated monoazo dye is converted into the chromium complex compound as described in Example 2.
The dried and powdered chromium-containing dye is a brown powder that dyes wool from neutral to slightly acidic baths in red-orange tones. The dyeings are lightfast and show very good wet fastness properties.

Example 6

18.8 parts of 2-amino-1-hydroxybenzene-4-sulfonic acid amide are diazotized as described in Example 1. The diazo compound is then treated with a solution of 28 parts of l- [N-dimethylaminosulfonyl-N-methyl] -amino-7-hydroxynaphthalene, 40 parts of 30% sodium hydroxide solution, 20 parts of soda and 300 parts of water are combined.

The isolated dye is converted into the chromium complex according to the instructions in Example 2.

This dissolves in water with a violet-brown color and dyes wool from a neutral bath in light- and wet-fast corinth tones.

The following table contains further monoazo dyes and metal-containing azo dyes, which according to the details of Examples 1 to 6 are available. In the table they are through the diazo component - column. (I) -, the azo component - column (II) -, the type of use - Column (III) - and the color of the metal complex compound on wool or the spin dye - Column (IV) - marked. In the column (III) the abbreviations mean

Post chrome. = Post-chroming dye,

Cr-K = chromium complex compound,

Co-K = cobalt complex compound.

7th Azo component 8th Hue of (Π) Metal complex
link· example Diazo component Usage type on wool or No. 0) 1 -acetyl amino-7-hydroxyn aph- (Hl) the spin dyeing
(IV) thalin Blue-gray 7th 2-amino-1-hydroxy-4- (N-dimethyl - Cr-K aminosulfonyl-N-methyl) -amino- Acctoacetylamino-benzene benzene 2-ammonaphthalene yellow 8th the same l-Hydroxy-2-acetylamino-4-methyl- Cr-K Gray 9 the same benzene Co-K Brown 10 2-amino-1-hydroxy-4-dimethyl- Cr-K aminosullonylamino-6-nitro- 2-hydroxynaphthalene benzene 2-hydroxynaphthalene-3,6-disulfone- Gray 11 the same sow Cr-K Navy blue 12th the same 1 -Pb enyl-3-m ethyl-5-pyrazolone- Post chrome. 3'-sulfonic acid Red-brown 13th 2-amino-1-hydroxy-4-cüäthyl- Post chrome. aminosulfonylamino-S-chloro- Acetoacetylamino-2-ethylhexane benzene 2-hydroxynaphthalene orange 14th the same Cr-K Gray 15th 2-amino-1-hydroxy-4-dipropyl- 1-Hydroxy-4-methoxynaphthalene Cr-K aminosulfonylaminobenzene blue 16 2-amino-1-hydroxy-4-methyl- Cr-K 6- (N-diethylaminosulfonyl-N- the same at hyi) -aminobenzene Gray 17th 2-amino-1-hydroxy-6-acctylamino- Cr-K 4-dimethylaminosulfonylamino- 2-phenylaxninonaphthalene benzene Greenish gray 18th 2-amino-1-hydroxy-4- [N-dimethyl- Post chrome. aminosulfonyl-N-methyl] -amino- 1-phenyl-3-methy] -5-pyr azolone - benzene-6-sulfonic acid 3'-sulfonic acid methylamide Red 19th the same 1 -Hydroxynaphtb aline-4-sulfonic acid Post chrome. 2-acetoacetylaminonaphthalene- Navy blue 20th the same 6-sulfonic acid Post chrome. Brownish yellow 21 the same l-acetoacetylaminobenzene ^ -sulfone- Post chrome. acid phenyl arid yellow 22nd 2-amino-1-hydroxy-4-dimethyl Co-K am t η osulf onylaminobenzene- l- (3'-chloro) -phenyl-3-methyl- 6-sulfonic acid amide 5-pyrazolone Brownish red 23 2-amino-1-hydroxy-4-di-isopropyl- Cr-K aminosul fonylamiri topzol - 2-Hydroxynaphthalene 6-sulfonic acid methylamide violet 24 2-amino-1-hydroxy-4-dibutyl- Co-K aminosulf onj'laminobcn zol- 6-sulfonic acid (2'-hydroxy) - 2-Hyrlroxynaphthalin-6-sulfone- ethylamide acid Brownish gray 25th 2-amino-1-hydroxy-4-morpholyl- l- (2 ', 3'-tetramethylene) -phenyl- Post chrome. aminosulfonylaminobenzene 3-n-ethyl-5-pyrazolone-4'-sulfone- Brownish red 26th 2-amino-l-hydroxy-4-pipcridyl- acid methylamine Cr-K aminosulf onyl aminobenzene the same Brown orange 27 2-Amjno-S-dimethylaniinosulfonyl- l-acetoacetylaminobenzene-4-sulfone Post chrome. amine obenzol-l -carbon acid acid (2'-methoxy) phenylamide yellow 28 the same 1-hydroxy-4-ynethoxynaphthalene Cr-K Blue violet 29 2-amino-5- [N-dimethylamivio- Cr-K sulfonyl-N-meth} d] -aminobenzene- 1-carboxylic acid

9 Azo composites 10 Hue of αϊ) Metal complex
link example Diazo component Usage type on wool or No. (D (III) the spin dyeing 2-hydroxynapbthalene (IV) violet 30th 2-amino-5- [N-diethylamino- Cr-K sulfonyl-N-methyl] -aminobenzene- 1-dimethylaminosulfonylamino- 1 -carboxylic acid 7-hydroxynaphthabn Purple gray 31 the same the same Cr-K Gray 32 2-amino-1-hydroxy-4-nitro-6- [N- Cr-K dimethylaminosulfonyl-N-ethyl] - l- (4'-dimethylaminosulfonyl- aminobenzene amino) -phenyl-3-methyl-5-pyr-
azolone Red-brown 33 the same 2- (4'-DiethylaTninosulfonylamino) - Cr-K phenylaminonaphthalene Gray 34 the same 1 -acetoacetylamino-4-diethyl- Co-K aminosulfonylaminobenzene yellow 35 2-amino-1-hydroxy-4- [N-dimethyl- 2-hydroxynaphthalene Co-K arninosurfonyl-N-methyl] -ainino-
benzene 1 - [N-dimethylaminosulfonyl- violet 36 the same N-methyl] -amino-7-hydroxy- Cr-K Brown purple 37 2-amino-1-hydroxy-4-nitrobenzene naphthalene Cr-K 1 -Dimethylaminosulfonylamino- 7-hydroxynaphthalene Greenish gray 38 2-amino-1-hydroxy-5-nitrobenzene the same Cr-K the same Greenish gray 39 2-amino-1-hydroxy-4-chloro-6-nitro-
benzene the same Cr-K Greenish gray 40 2-Ammo-l-hydroxy-6-chloro-4-nitro-
benzene 1 - (4'-dimethylaminosulfonyl- Cr-K Greenish gray 41 2-amino-1-hydroxy ^ .o-dinitro-
benzene ammo) -phenyl-3-metbyl- Cr-K Yellow-brown 42 2-amino-1-hydroxy-4-acetylamino- 5-pyrazolone Co-K benzene the same orange 43 2-amino-1 -h.ydroxy-4-methyl- 1 -dipropylaminosulfonylamino- Cr-K sulfonylbenzene 7-hydroxynaphthalene Gray purple 44 the same l- [N-dimethylaminosulfonyl-N-me- Co-K Gray thyl] amino-7-hydroxynaphtha] in Cr-K Corinth 45 2-amino-l-hydΓoxybenzene-4-sulfone- the same Cr-K acid ethylamide Gray 46 2-amino-1-hydroxybenzene-5-sulfone 1 - [N-dimethylaminosulfonyl-N- Cr-K acid amide methyll -amino-7-hydroxynaph-
thalin Gray 47 the same l-morpholylsvdfonylaniino- Cr-K 7-hydroxynaphthalene Gray 48 2-amino-1-hydroxy-4-chlorobenzene the same Cr-K Gray 49 2-amino-1-hydroxybenzene-4-sulf on- 1-dimethylaniinosulfonylamino- Cr-K Gray purple acid amide 7-hydroxynaphthalene Co-K Gray purple 50 2-amino-1-hydroxybenzene-4-sulfone 1-piperidylsulfonylamino Co-K Gray acid methyl amide 7-hydroxynaphthalene Cr-K Gray 51 2-amino-1-hydroxybenzene-4-sulfone l- [N-morpholylsulfonyl-N-methyl] - Cr-JK Gray purple acid (2'-hydroxy) ethylamide amino-7-hydroxynaphthalene Co-K Corinth 52 2-amino-1-hydroxybenzene-4-sulfone- 1 -dibutylaminosulfonylamino- Cr-K acid (3'-methoxy) propylamide 7-hydroxynaphthalene Gray 53 2-amino-1-hydroxybenzene-4-sulfone Cr-K acid amide

U Azo component 12th Hue of (II) Metal complex
link Example) Diazo component Usage type on wool or No. (I) (ΙΠ) the spinning coloring 1 - (4'-dimethylaminosulfonyl- (IV) amino) -phenyl-3-methyl- orange 54 2- amino -1 - hydroxybenzene-4-sulfone- 5-pyrazolone Cr-K acid amide 1 -acetoacetylamino-i-dimethyl- aminosulfonylaminobenzene yellow 55 the same 1 -Diethylaminosulfonylamino- Co-K 7-hydroxynaphthalene Gray 56 the same 1- [N-diethylaminosulfonyl-N- Cr-K ethyl] -amino-7-hydroxynaph- Corinth 57 the same thalin Cr-K 1 - [N-dimethylaminosulfonyl-N- methyl] -amino-7-hydroxy- Brown purple 58 2-amino-1-hydroxy-4-chlorobenzene naphthalene Cr-K 1 - [N-diethylaminosulfonyl-N- methyl] -amino-7-hydroxy- Brown purple 59 2-amino-1-hydroxy-4-chlorobenzene naphthalene Cr-K l- [4 '- (N-dimethylaminosulfonyJ- N-methyl) -amino] -phenyl- Yellowish brown 60 the same 3-m ethyl-5-pyrazolone Cr-K the same the same yellow 61 2-amine above-zol-1-carboxylic acid Cr-K orange 62 2-amino-1-methoxybenzene- 1 - Acetoacetylamine 4- [N-dimethyl- Cr-K 4-sulfonic acid phenylamide aminosulfonyl-N-methyl] - yellow 63 2-aminobenzene-1-carboxylic acid aminobenzene Co-K 1 -Dimethylaminosulfonylamino- 7-hydroxynaphthali η Gray 64 2-amino-1-hydroxy-4-methyl- the same Cr-K sulfonyl benzene Gray 65 2-amino-1-hydroxybenzene-4-sulfone the same Cr-K acid (2'-hydroxy) ethylamide olive green 66 2-amino-1-hydroxy-4-nitro- Cr-K 6-acetylaminobenzene

Claims (4)

PATENT CLAIMS: 45 1. Process for the preparation of monoazo dyes and their metal complex compounds, characterized in that 1 mol of the diazo compound from one in the o-position to the amino group a substitute capable of forming metal complexes carrying aminobenzene with 1 mole of a position adjacent to a phenolic or enohscheii Hydroxy group or to a primary or secondary Amino group coupling azo component combined and the resulting dye, which is at least once and at most twice the grouping R ₁ - N —SO _a - must have, in which R is hydrogen or a low molecular weight alkyl or hydroxyalkyl radical, R _{1 is} a low molecular weight unsubstituted alkyl radical and R _{2 is} a low molecular weight unsubstituted alkyl radical or together with N and R _{1 is} the radical of a saturated heterocyclic amine, treated in substance or on the fiber with a metal donor in such a way that a metal-containing azo dye is formed which has essentially 1 metal atom on 2 molecules Contains monoazo compound bound in complex. 2. The method according to claim 1, characterized in that there are 2 molecules of monoazo dye an amount of a metal donor containing less than 2 but at least 1 metal atom can act. 3. Process according to Claims 1 and 2, characterized in that the metal donor is used a chromium donating agent is used. 4. Process according to Claims 1 and 2, characterized in that the metal donating agent is used a cobalt donor used. Considered publications:
French Patent No. 1,095,561;
U.S. Patent No. 2,623,871. When the application was announced, 1 staining table and explanation as well as 3 priority documents were displayed. Qt 909 707/282 12.5 »