CA1060603A - Stable concentrated solutions of dyestuffs containing sulfonic acid groups, process for preparing them and their use - Google Patents

Abstract

STABLE CONCENTRATED SOLUTIONS OF DYESTUFFS CONTAINING
SULFONIC ACID GROUPS, PROCESS FOR PREPARING THEM AND
THEIR USE

Abstract of the disclosure:
A stable concentrated solution of a dyestuff consisting of 10 to 80 percent by weight of a dyestuff containing 1 to 3 sulfonic acid groups, in form of the free acid of a salt, 10 to 82 percent by weight of water and 8 to 80 percent by weight of .epsilon.-caprolactame, the said solution being suitable for the preparation of dyeing liquors or printing pastes for the dye-ing or printing of native or synthetic polyamide fibre materials and for the coloring of paper.

Description

It is knOl~ that for dyeing and printing nitrogen-contain-ing fibre materials, such as wool, silk or synthetic polyamide fibres, dyestuffs are used which contain sulfonic acid groups in the form o~ finely ground powders contain~ng non-dyeing di-luents, w~ch have to be dissol~ed in the dyebath. Without re-gard to the unpleasant ~ormation of dust of the intensely dyeing dyestu~ caused by the powder form and to the risk of clogging of the dyestuff powders, the preparation of the dyebath is ren-dered difficult owing to the mostly po~r solubility of many dyestuffs.
In the dyeing of clear to medium shades from a long ba~h the dissoluti~n does not yet cause any difficulties, all the mDr~ since the dyeing proce3s is generallv carr~ed out a+ bo~l-ing temperature. When dyeing deep shades, however, it is often impossible, even at boiling temperature, to dissolve the dyestuffs completely.
A great number of dyestuffs of easy manu~acture and high general fastness properties, which, at boillng temperature, are rarely sufficient for dissolutio~, are insufficient in the dye-bath or printing pastes used at room temperature for continuous dyeing processes or te~tile printing; they are, therefore, ex- -cluded from these fields of application.
It is further known that with the aid of organic solvents in combination with other auxiliar~es concentrated dyestuff soluti~ns may be prepared.
Accordlng to German Offenlegungsschri~t ~o. 2,0499620 stable but only ac~dic solutions of azo dyestuffs containing sul~onic acid groups are obtained with the aid of a solvent 29 mix~ure that conta~ns a water-miscible carboxylic acid having ~ .

.

. .
-~,:

-~ HOE_74/F 370 to 3 carbon atoms, water and water-miscible solvents.
German Offenlegungsschrift No. 2,021,520 describes the ~reparat~on of concentrated solutions of dyestuffs containing sulfonic acid groups, which dyestuffs may only be prepared from dyestuffs in the form of the salts of determined poly-glycol ami~es, with the addition o~ optionally necessary sol-vents.
For the preparation of the concentrated dyestuff solutions described in German Offenlegungsschrift ~o. 2,020,295 both phosphorus-containi~g sol~ents an~ additives of di~persing agents and further organic solvents are optionally $ndispen-sable.
Concentrated water-s oluble stock s oluti ons of dyestuffs containing sulfonic acid groups may be prepared according to ~5 German Offenlegungsschrift No. 2,031,134, with the aid of a synergetically act~ve mixture of solvents consisting of glycol and formamide derivatives, the applicability being limited to chrome-containing dyestu~fs.
According t~ German Offenlegungsschrift ~o. 2,335,512 concentrated dyestuff solutions may be prepared with the use of synergetically active mixtures of solvents consisting of aprotic solvents and glycol or of a glycol ether; water may additionally ~erve as a solvent.
German Offenlegungsschrift No. 2,033,989 describes the preparation of ~oncentrated solutions of metal complexes of azo dyestuffs containing sulfonic acid groups, with the use of organic solvents where~at optionally al50 solid compounds, ` such as caprolactame, have to be added.
29 Subject of the present invention are stable, concentrat--- , . , , . . ~ .

. . , ' , ' , ' ', , .
' - . . ' .

HOE 74/F ~7C

ed aqueous solutions containing -caprolactame of dyestuffs containing at least one sulfonic acid group, the dyestuffs being present in the form of the free acid or as a salt con-taining 10 to 80 perce~t by weight of azo-dyestuf~ containing at least one sulfonic acid group9 10 to 82 percent by weight of water and 8 to 80 percent by weight of -caprolactame; the invention also provides the preparation of these solutions and their use for preparing dyeing liquors or printing pastes for dyeing or printing natural or synthetic polyamide fibre materials or for roloring or printing paper.
Si~ce these solutio~s do not contain any organic sol~ents, dangerous or inde~irable solvent vapors are a~oided during preparation and u~e; thus, expensive equ~pment to remG~e them and to render them harmless are not necessary.
The solutions are prepared by d~ssolYing the dyestuffs ~-.
containing sulfonic acid groups, in water with the use of ~-caprolactome.
The preparation is carried out in detail as ~ollows:
the dyestuff salts or dyestuff acids are stirred in dry ~r moist form, for example, in the form of the moist filter press-caXe, in an aqueous -caprolactame solution at room temperature or slightly elevated temperature, for example at a temperature of from 35 to 50C, until a homogenous solution is formed. 0 course, the preparation ma~ also take place at higher tempera-ture.
A further possibility of preparation consists in adding the -CaprQlaCtame to the d~estuff suspension obtained at t~e end of the dyestuff preparatlon process; thus, a technically useful 29 composition is obtained, so that the usual process steps such 1~3~ iC~;~
as salting out, filtration, drying and dust-removing are dis-pensable, and therefore, save expenses.
The percentage of the ~-caprolactame solution may vary within wide limits, It depends both on the solu~ty of the dyestuII and the am~uni to be dissolved.
It is also important to take into account the requirements of v~sc~sity met by th~ckened dyestuff solutions and printing pastes, for example for space dyeing and continous dyeing pro-cesses for carpet yarn and piece material from polyamide fibre materials.
A standardization with a liquid is particularly expedient in dyestuffs c~ntaining sulf~nic acid groups, which are not sufficiently ~oluble in water, in pri~ting pastes or in dyeing liquors. These are especially the dyestuffs that contain only one sulfonic acid group.
The dye~tuffs containing the sulfonic acid groups belong, for example, ~ the classes of the monoazo, disa~o, anthraqui-none t nitro- and triphenyl-methane dyestuffs.
As concerns the number ~f the sulfonic acid groups in the dyestuff molecule5 it generally amounts to ~ or 2, except~Dnal-ly to 3 sulfonic acid.groups.
In the following there are mentioned som dyestuffs con-taining sulfonic acid groups characteri~ed by C.I. numbers or rmul~ bioh dyestuffs ha~e a special technical importance.

. .. . , ., , . ,.~ . . , ,, ,.. , , , - . . ,, , : ~, . , :, , , ,, ~ - , :, . , .. :,. . .

... " ,. . .. . . . ..

HC)E 7~LF 3 .~3tiO~

C. ~. lo 3~5 ~o 410 14 170 14 69017 o70 18 835 19 o25 22 91o 24 80026 360 26 370 26 550 44 510 ~ 7~ . 125 62 ' ~30 NH , - ( blue H3C ~f C~l3 ~ , ' ' '~.
- C:H3 " . . .
f~NH~ ~

SO ~ Na - (blue3 3 ~ 3 S03H (yellow) - HaC . 4 CH

CH3 ~ '~ ~S~3H (red) ~, S03 . : . . . . . . ..... . . . .. . . .
.: . , . ., ,. . .,.. , . , ., ,: . . - ~, . ~

HOE 7~/F
V~

The dyestuf~s containing at least one sulfonic acid may be used in the form of the free acid or as salt, for example as Plkali metal salt or ammonium salt.
~iquid.compositions of dyestuffs are especially suitable for all continuous dyeing and printing processes, in which a rapid, easy refilling of dyestuff solutions or printing pastes from storage vessels is necessary to ensure that the dyeings and prints turn out evenly. The novel liquid compositions of dyestu~fs containing at least one sulfonic acid group are ex-10 cellently suitable to resolve problems of dissolution of com-mercial powder bra~ds of such dyestuf~s.
Thus, unpleasant dusting is avoided. Wetting problems which may arise during the rapid dissolution of dyestuf~s do not exist. Furthermore, depending on the amount of ~ -capro-15 lactame usedl the dyestuff solutions are inert towards electro-lyte additives or additives capable of reducing the solubility of the dyestuf~s used.
As compared with known compositions containing more or less volatile solvents the problem of the solvent vap~rs during 20 the dyeing process does not exist an~ longer. Surprisingly, the resistance to storing o~ the dyestuff solutions containing -caprolactame and the dyestuff absorption capacity of the aqueous -caprolactame solution are considerably superior to the usually employed solvents of the state of the art, calcu-25 lated on the ratio of their molar amount used to the dyestuff u~ed.
The fol~owing Examples illustrate the invention. Parts and percentages are b~ weight unless stated otherwise.

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E X A M P ~ E 1:

21.5 Parts of the dyestuff of the formula p NH~
SO~H
0~, .

ha~ing a content of pure dyestuff of 88% were ~ntroduced at room temperature in the form of the dyestuff powder or in form of the moist ~ilter cake into a solutior.~ of 41 part~ of ~ca-prolactame in 59 parts of water. The mixture was stirred for one hour. A stock solution resistant to storage was obtaine~
which could be diluted with water at choice, without precipl-tating the dyestuff; dyestuff solutions were obtained whlch were suitable for dyeing and printing wo~l, p~lyamide fibre materials, ~eather and paper.
Whereas only 2 parts of dyestuff were dissolved i~ 100 parts of water, 21.5 parts of dyestuff were dissolved in the abo~e-mentioned aqueous ~-caprolactame solution. In form of such a stock ~olution the dyestuff could be used for the dye-ing and printing of polyamide fibre materials ac~ording to the carpet-continuous dyei~g process and the space dyeing.
If instead o~ -caprolactame the same m~lar amount of' solvent or auxiliary aceordi~g to the state of the art wa~
usèd ~ the solvent being adjusted to 100 parts with water -only the following parts o~ dyestu~f were soluble; i.e. when -- 8 -- .
, .

- . . ., :

HOE 74/F ~70 using a) urea 4 parts b) tetramethyl urea 17 parts c) dimethylfo~mamide 10 parts d) glycol 4 parts e) diethylene glycol 13 parts dimethyl ether f) hexamethyl-phosphoric 15 parts acid triamide Carpet-continuous-d~ein~ process eparation of the d~ebath 125 Parts of the stock solution described bove were di-luted with 700 par~ of water. This so~u~.ion was poured, while stirring vigorDusly, into 150 p~rts of a 2~o aqueous solution D~
a locust bean flour thickening. To the dyebath, depending on the pH value desired, 0.8 to 4.0 parts of buffer substances were added, as for example a 60% acetic acid, sodium acetate5 mono, di or trisodium phosphate. With 21 to 24.2 parts of water the bath was completed to 100 parts, A dyebath free from specks was obtained, the viscosity of whic~ completely full-fills the conditions of the carpet - continuous-process. Poly-amide fibre material may be dyed homogeneously and ïree frc)m specks. With the use of poly~amide differential dyeing fibre types, di~ferent shadow dyeings could be obtained - dependsnt on the pH value, with the aid of the dyeing llquor described above.
S~ace-D:rein~
Preparation of the P~ g~
29 375 Parts of the stock solution descri~ed abore were di-_ 9 _ .

- . . . . . . . .

HOE ?4/F 370 O~
luted with ~63 parts of water. This solution was poured, l~ile stirring vigorously, into 350 parts of a 2~ aqueous solution of a locust bean flo~r thickening. 12 Parts of a 60% acetic acid were a~ded t~ the printing paste. 1000 Parts of a print-ing paste free from spec~s were obtained, the viscosity of which meets the requirements of the space-dyeings. With the aid of this printing paste fabrics of polyamide could be print-ed. With the aid of such an aqueous dyestuff solution contain-ing -caprolactame more than 60 parts of dyestuff were soluble in 1000 parts of pr~ntlng paste. Howe~er, when the dyestuff powder free from -caprolactame was used, a printing paste free from specks was obtained when using 10 parts of dyestuff powder at a maximum.
E X A M P ~ E 2:
~8 Parts of the dyestuff of the formula ~0 ~l035 ~ ~ ~O

having a content of pure dyestuf~ of 95% were introduced in the form o~ the dyestuff powder or in the form of the moist filter cake, at room temperature, into a solution of 30 parts of ~-c~prolactame in 70 parts of water, and stirred for one hour at room temperature. A solution resistant to storage was obtai~ed which c~uld be diluted at ch~ce with water with~
out the dyestuff being precipitated. Solutions were ~btain-ed which were suitable for dyeing and printing wool and poly-amide fibre materials. As a comparlson, without the addition of ~-caprolactame only 2 parts of dyestuff powder were dissol~-: .: - . . , . , ' 1 . ~ . .
,, .; ! . ' , ' ~ , : ~ . ,. ' ' ' ;' ~, , , ' ' ; ' . ' ` . .. : ' :

': , `, ' . '' .; . :: .,~",~ :

ed i~ 100 ~arts of water at room temperature.
If instead of ~caprolactame the same molar amou2lt of solvent or auxiliary according to the state of the art was used - the s.olvent being ad~usted to 100 parts with water -only ihe I ollowing parts OI dyesluII were soluDie; i . e . w~l~r using a) urea 4 parts b) tetramethyl urea 3 parts c) dimethylformamide 4 parts d) glycol ~ parts e) diethylene-glycol-dimethyl 3 parts ether ~) hexamethyl-phosphor~c ~cid 3 ~arts triamide E X A M P ~ E 3:, 25 Parts of the dyestuff of the formula -,~;N~I~3~NH~

- having a content of pure dyestuff of 95% were introduced int~
a solution of 30 parts o~ ~-caprolactame in 70 parts of water and stirred vigorously at room temperature. A solution fast to storing was obtai~ed, wh~ch could be diluted at choice :-with water, without the dyestuff being precipi~ated.
Solutions were obtained which were suitable for the dyeing - .. ~ .. . .
. , ~ : . :. , : ~ : ' .', . .. ..
- . -.. - , : ,.
. ~ ' . , ' HOE 74/F ~70 or printing of wool, polyamide fibre materials and paper.
As a comparison, without the addition of -caPr~lactame, o~ly 0.8 part of dyestu~f powder were dissolved in 100 parts o~
water at room temperature.
If instead o~ -caprolactame the same molar amount of . solvent or auxiliary according to the state of the art was used - the sol~ent being adjusted to 100 parts with water -only the following parts of dyestuff were soluble; i.e. when using a) urea 2 parts b) tetramethyl urea 23 parts c) dimeth~lformamide 7 parts d) glycol 3 parts e) diethyleneglycol-dimethyl 7 parts ether f) hexamethyl~phosph~ric .20 parts acid triamide E X A M P ~ E 4:
10 Parts of the dyestuff of the formu~

H3C ~
S02. 03H
N~

having a content of pure dyestuff of 80% were introduced into a solution o~ 10 parts of ~-caprolactame in 90 parts of water and stirred vigorously at room te~erature. A solution resi-stant to storage was obtained, which could be diluted with water at choice, without the dyestuf~ bei~g precipitated; dye~

- ~2 -... ~ . ~ . . .

- , , ........................... . .~ . , .

: ' -; ' ' : .: . .

HOE 74!F 370 l~ti~V~
stuff sclutions were obtained which were suitable for dyeing and printing wool, polyamide fibre materials and paper.
If instead ~f ~-caprolactame the same molar amount of solvent or auxiliary according to the state of the art is used - the solvent being adjusted to 100 parts with water - Dnly the following parts of dyestuff were soluble; i.e. when using a) urea 2 parts b) tetramethyl urea 3 parts c) dimethyl~ormamide 3 parts d) glycol 2 parts e) diethyleneglycol-dimethyl ~ parts ether f) hexamethyl-phosphoric 1 part acid triamide E X A M P ~ E 5:
17 Parts of the dyestuff o~ the formula Cl -H03$ ~-N ~ O3H
~ ~=' N Cl :
ha~lng a content of pure color of 70% were introduced into a solution of 50 parts of -caprolactame in 50 parts of water and stirred vigorously for one hour at ro~m temperature. A
solution resi~tant to storage was obtained, which could be di- -luted at ch~1ce with water without the dyestu~f being precipi-tated; solutions were obtained, which were suitable for dyeing or printing wool, polyamide fibre materials and paper.
If instead of -caprolactame tne same mola~ amount of sol~ent or auxiliary according to the state of the art was .. . .. ..
- - . ~ ; . - . , - . . - .

,, , ~ . . .

.
- , ~ . . . ,, .. ~ .

used - the solvell5 being adjusted to 100 parts with water -only the f~llowing parts of dyestuff ~ere soluble; i.e. when usin~
a) urea ~ 9 parts b) tetramethyl urea 12 parts c) dimethylformamide 10 parts d) glycol 6 parts e) diethylene-glycol- 12 parts dimethyl ether f) hexamethyl-phosphorle 9 parts acid triamide E X A M P ~ E 6:
10 Parts of the dyestuff of the formula S3~ CH3

2~ N~I~N==N~_N=~DSOz~c~3 ~ X - 6-S03NA or 7-S03NA

were introduced into a solution o~ 10 parts of -caprolactame in 90 parts of water and stirred vigorously for one hour at room temperature, A ~o~ution resistant tP storage was obtain-ed, which could be diluted with water at choice1, without t~e dyestuff being prec~pitated. Dyestuff solutions were ~btained which were suitable for dyeing or printing wool, polyamide fibre materials and paper.
If instead of ~-caprolactame the same molar amount of sol~ent or auxiliary according to the state of the art was used - the solvent being ad~usted to 103 parts with water -only the following parts of dyestuff were soluble; i.e. when :- - 14 -.. . .. . . . . .
. . . . , . .
- . , . ~ . . - . . , ,, : .. . ... ,,. .,- ~ . : ., . , .:

- , - - , .
- . - . , , . -, .

HOE 74/F ~70 using a) urea 2 parts b) tetra~ethyl urea4 parts c) dimethylformamide6 parts d) glycol 6 parts e) diethylene-glycol-3 parts dimethyl ether i~) hexamethyl-phosphoric 2 parts acid trlamide ' - 15 -- ~ - - - - . -.... . . .

., - . . . , - - -:

. . ~ ; . . . .
. . . .. . . ~

Claims (3)

We claim:

1. A stable concentrated solution of a dyestuff consisting of 10 to 80 percent by weight of a dyestuff containing 1 to 3 sulfonic acid groups, in form of the free acid of a salt, 10 to 82 percent by weight of water and 8 to 80 percent by weight of .epsilon.-caprolactame.

2. The solution as claimed in claim 1, wherein the dyestuff is a monoazo-, disazo-, anthraquinone-, nitro- or tri-phenylmethane dyestuff.

3. The solution as claimed in claim 1, wherein the dyestuff is present in form of an alkali metal or ammonium salt.