JPS5838556B2 - Dyeing method for natural and synthetic polyamide fibers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for dyeing natural and synthetic polyamide fibers with post-chromed dyes.

This process is based on the fact that after the dye has been absorbed into the fibers, the molar ratio of the dye nichrome -2:1 to 1:2, especially 2:1 to 1:1, of the chromating agent and the anion is phosphorus, sulfur and/or chlorine. It is characterized in that the fibers are treated with a water-soluble acid and/or a salt thereof that contains a chromophore and does not have a chromophore.

It is known to produce postchromed dyeings in the presence of these water-soluble compounds.

In subsequent chroming, the chromating agent is used in an amount substantially greater than that required to form a complex with the dye present on the fiber.

As a result, hexavalent chromium remains in the residual liquid, which thus enters the effluent and causes ecological damage due to its toxicity.

When the amount of chromium is reduced to an extent corresponding to the formation of a complex,
Partial chromation takes place without difficulty and the dye exhibits very poor wet fastness which cannot be compared to that obtained with excess chromating agent.

Now, according to the invention, using the method of the invention, an amount of chromating agent that is substantially less than that of the known method is required to reach a level of fastness distantly related by the known method. It was found that dyeings with fastness of .

As chromating agent it is possible to use all salts of hexavalent chromium commonly used in post-chromation processes, preferably potassium dichromate.

Suitable dyes for this novel method include all known later chromated dyes.

- It is an 0'-dihydroxy-azo dye.

These dyes are described, for example, by Ho, R. Schweiz
Monograph “KThnstliche o” by er
rganische farbstoffe un
dihre Zw i 5chenproduct
“(“Synthetic organic dyes and their intermediates”), Sp
ringer Verlag (1964), 464-4
It is listed on page 70.

Possible water-soluble acids and salts are in particular sulfuric acid, amidosulfonic acids, alkylsulfonic acids, arylsulfonic acids,
Aralkylsulfonic acids, alkylsulfuric acids, phosphoric acids, ring phosphoric acids, amidophosphonic acids, alkylphosphonic acids or alkylphosphinic acids, arylphosphonic acids or arylphosphinic acids, alkylphosphoric acids or alkylphosphorous acids and their alkali metal salts, preferably are sodium and potassium salts.

Equally preferably water-soluble addition products of these compounds with alkylene oxides can be used.

The alkyl group in these salts has, for example, 1 to 18 carbon atoms, preferably 1 to 4 carbon atoms.

Aryl is in particular understood to mean phenyl, which can be substituted by an alkyl group, preferably having 1 to 4 carbon atoms, one or two halogens, preferably chlorine or bromine.

Such water-soluble compounds include, for example, K.

L 1ndner, 'Ten5ide, Texti
lhi lfsmittel.

Waschrohstoffe” (“Surfactants, textile auxiliaries and detergent raw materials”), 2nd edition (1964)
, Volume 1, pages 636 onwards, pages 824 onwards, and pages 832 onwards.

Examples of water-soluble compounds are as follows.

Sodium, potassium or ammonium salts of methyl sulfate or ethyl sulfate, sodium inamyl sulfate,
Sodium lauryl sulfate, sodium or potassium salt of methanesulfonic acid, sodium benzenesulfonate whose benzene ring may be substituted with chlorine, nitro, methyl, amino, phenyl or phenylamino, sodium benzylsulfonate, naphthalene-1- Sodium sulfonate, sodium naphthalene-2-sulfonate,
Amidosulfonic acid or its ammonium salt.

Preference is given to using alkali metal salts of sulfuric acid or ammonium sulfate, especially sodium sulfate.

The amount of water-soluble compound used depends on the amount of dye and the fiber.

, the sum of the dye and salt equivalents should be chosen to reach or exceed the anion binding capacity of the fiber.

Is this 1oof fiber? For example, in the case of wool, it is about 0.085 gram equivalent per 100P of wool (W, Ender
and AlM (iller, “Melliand Te
xtilberichte “18 (1937), 63
3-637.732-733.809810 and 90
(See pages 6-907).

Preferably, 2 to 15% salt relative to the weight of the fibers is added to the liquor.

The preferred amount of sodium sulfonate when dyeing wool is 5-10% with respect to the weight of the wool.

Appropriate ratios can be easily determined or calculated by preliminary experiments.

The method according to the invention can be used for dyeing natural and synthetic polyamide fibers in all processing states, such as flock, top, yarn, knitted, woven or stockinette.

Preferably, this method is used for dyeing natural polyamide fibers, especially wool.

The process is carried out by treating the fibers with post-chromed dyes in a known manner, if appropriate in the presence of nonionic auxiliaries, but without the addition of the compounds used according to the invention.

After the dye has been absorbed, the pH value is corrected to 2.5-4 by optionally adding an acid, for example formic acid or acetic acid.

Further processing can then be carried out according to various methods.

(a) Add a water-soluble salt to the solution, and add about 70 to 100% of this solution.
Heat to 0°C for approximately 15-20 minutes.

The chromation is then carried out in a customary manner using the amount of chromating agent to be used according to the invention at the boiling point or at a temperature below or above the boiling point.

(b) Add to the solution the amount of chromating agent to be used according to the invention, carry out the chromation as in (a), then add the water-soluble salt and bring the temperature to about 70-100°C for 10-100°C.
Hold for 20 minutes.

(e) Add the water-soluble salt and chromating agent together to the liquor and carry out the chromation as in (a).

In this case, two parts of the salt can also be added together with a part of the chromating agent, and then the remaining part can be added after reaction with the fibers.

Chromation can be carried out in fresh liquor or in the liquor in which the dye has been applied to the fibers.

This new method has the following advantages over known methods.

As a result of the reduced amount of chromium used, the dyed fibers contain substantially no chromium that is not bound to the dye.

This greatly increases spinning yield. The physical and technical properties of the wool are also improved.

Urea-bisulfite solubility (HoZahn.

“Quantitative Chemistry P
rl! if method denft! zr Wolle
“(“Quantitative chemical test method for wool”) German Wool Research Institute at the Technical High School, Aachen 39 (1
963)) as a measure of these properties, it has been found that the rate of reduction is lower in the case of the present invention than in the case of known chromation methods.

Another advantage of this new method is that there is no detectable hexavalent chromium in the chromation residue.

Since the amount of trivalent chromium in the residual liquid is on the order of several ppm, it is ecologically harmless.

In the following examples, parts are parts by weight.

Example 1 Sooo parts water, 12 parts acetic acid (60% strength), 8 parts formic acid (85% strength) and 36 parts dye C,I,Mor
40 in a solution consisting of dant Violet (C, I, AL5670).
0 parts of wool yarn is dyed at 100° C. for 90 minutes.

After dyeing, the yarn is rinsed with hot and cold water. The chromization of this dyeing is carried out in a second liquor.

For this purpose, 40 parts of sodium sulfate and 12 parts of 85% strength formic acid are introduced into 8000 parts of water at 70°C.

After introducing the thread, the temperature of the liquid was increased to 10°C for 20 minutes.
Raise to 0°C.

Then 5.4 parts of potassium dichromate (molar ratio of dye dichromium=i, s:i) are added.

The thread remains in the boiling chromating solution for a further 60 minutes.

Along the way, the original deep red color changes to black.

The pH value at the end of the treatment is 3.8. Remove the thread from the chromating solution and rinse with hot and cold water.

At the end of the chromation process, the bath does not contain hexavalent chromium.

Wool contains a total of 0.32% chromium, and the urea-bisulfite solubility of this wool is 21.5% (initial value =
40%).

Staining and chromation corresponding to this example were carried out according to the current state of the art (W, Richter and HlRbs).
Termundt,' Die Wollfarbst
offe undihre Anwendtlng
” ('Dyeing of wool and their use'), Deu
tscher F! rberkalender78(
1974), pp. 187-221), without adding 40 parts of sodium sulfate, but increasing the amount of potassium dichromate from 5.4 parts to 10 parts according to known rules for calculating the amount of potassium dichromate. increase to %.

At the end of the chromation, the bath in this case contains 0.75 mg/
Contains 1 of hexavalent chromium.

Wool contains a total of 0.64% chromium, and the solubility of urea-bisulfite in wool is 9.5% (initial value = 4
0%).

Example 2 400 parts of wool yarn are dyed and rinsed according to Example 1.

To carry out the chromation, 5.4 parts of potassium dichromate (molar ratio of dye nichrome = 1.5:1) and 12 parts of 8
5% strength formic acid is dissolved in 8000 parts of water at 70°C.

The dyed thread is introduced into this solution and the temperature of the solution is increased to 100° C. over a period of 20 minutes and kept at this level for 20 minutes.

Now 40 parts of sodium sulfate are added and the thread is kept at 100° C. for a further 40 minutes.

The liquid OpH value at the end of the treatment is 3.8.

Remove the thread from the chromating solution and rinse with hot and cold water.

At the end of the process, the chromating solution does not contain hexavalent chromium.

Wool contains a total of 0.40% chromium, and its urea-
Bisulfite solubility is 18.2% (initial value -40
%).

A comparative staining according to the current state of the art is that described in Example 1.

Example 3 12 parts of 60% strength acetic acid, 8 parts of 85% strength formic acid and 36 parts of C, I, Mordant Viole
5oo to dissolve t5 (C,I,Al 5670 )
Dye 400 parts of wool thread in o parts of water.

At the end of 1 hour of dyeing for 90 minutes at 1000° C., 8 parts of 85% strength formic acid and 40 parts of sodium sulfate are added to the liquor and the dyeing is treated therein for a further 10 minutes, and 5.4 parts of dichromium Add potassium acid (molar ratio of dye nichrome - 1.5:1) and chromate the dyeing at 100 DEG C. for 5 minutes.

The dyed material is then rinsed with hot and cold water.

The current state of the art (see Example 1) corresponds to dyeing and chroming by a one-bath method, in which sodium sulfate is added at the beginning of the dyeing process and the amount of potassium dichromate added is increased to 10 parts.

Such a chromizing bath will contain a substantial amount of hexavalent chromium at the end of the chromating process, but in the process of the present invention, no hexavalent chromium remains in the residual chromating solution.

Example 4 36 parts of dye C0 dissolved in 500 parts of water with the addition of 12 parts of 60% strength acetic acid and 8 parts of 85% strength formic acid
Dye the top of 400 parts of wool with Mordant Black 9 (C, I, 16500).

The dyeing time is 60 minutes after reaching the boiling point, then the temperature is lowered to 70° C. and dyeing continues for 30 minutes.

Then, 3 parts of potassium dichromate (molar ratio of dye nichrome = 1.5:1) were added to the dyebath, and the solution was heated again at 100°C.
Heat to.

40 parts of sodium sulfate are added and the dyeing is boiled for 45 minutes.

This changes the color of the dye from deep red to black.

After rinsing with hot and cold water, the dyeing is changed and has a fastness comparable to that of a dyeing chromed with 8 parts of potassium dichromate in the absence of sodium sulfate.

Significant differences in urea sodium bisulfite solubility are found.

In the method according to the invention, the initial value is 45% to 33%.
However, in the state of the art method it is reduced by 5%.

Excellent results were also obtained if a mixture of 1.5 parts of potassium dichromate and 20 parts of sodium sulfate was used twice, instead of adding 3 parts of potassium dichromate and 40 parts of sodium sulfate in succession. available.

Excellent results are also obtained if, in place of 1 part of sodium sulfate, the following product of Part X is used.

Example 5 400°C at 40°C in 5ooo parts of water with 12 parts of 60% strength acetic acid and 8 parts of 85% strength formic acid.
Pre-treat the wool top for 15 minutes.

Next, part 12 of C, I, MordantBlac
kl 1 (C, ■, A14645) is added and the dye liquor is heated to 100° C. and boiled for 60 minutes.

A further 8 parts of 85% strength formic acid and 40 parts of sodium sulfate decahydrate are now added to the bath.

After a pretreatment time of 15 minutes, 1.2 parts of potassium dichromate (molar ratio of dye dichrome - 2:1) are added and chromation is carried out at 100 DEG C. for 45 minutes.

After rinsing with hot and cold water, the black dyeing can be changed and its fastness is excellent.
zurKenntnis der Nachchro
Textil-Praxis, (“Contribution to the Knowledge of Post-Chromation Staining”)
1968), A4, pages 257-261, using the same dye but with 6 parts of potassium dichromate, the fastness of the dyeing is comparable.

Significant differences between these two methods are found in the chromium content of the liquor at the end of chromation, the amount of chromium on the fibers and the urea-bisulfite solubility (initial value -45%).

If the chromation according to Example 5 is carried out at 90° C. for 60 minutes instead of 45 minutes at 100° C., an equally excellent result is obtained.

Example 6 8000 parts water, 12 parts 60% strength acetic acid, 8 parts 8
400 parts of wool flock are dyed in a dyebath prepared from 5% strength formic acid and the dyes listed in the table below in part X.

The staining time at 100°C is 60 minutes.

8 parts of 85% strength formic acid and potassium dichromate in the molar ratios listed in the table below are then added to the solution.

After 15 minutes at IoO'C, 40 parts of sodium sulfate are added and the wool is then chromed at boiling for 45 minutes.

After rinsing, the dyed fingers can be replaced with excellent fastness.

Wool is dyed at 105°C, and the dyed product is dyed at 105°C.
chroming for 20 minutes gives equally good results.

Claims (1)

[Claims] 1. A method for dyeing natural and synthetic polyamide fibers with post-chromed dyes, after the dyes have been absorbed into the fibers,
Treating the fibers with a water-soluble acid and/or its salts in which the chromating agent and the anion contain phosphorus, sulfur and/or chlorine and have no chromophore in a molar ratio of dye nichrome = 2:1 to 12. How to characterize it. 2. Process according to claim 1, in which the treatment is carried out with a total amount of dye and water-soluble acid and/or its salt corresponding to the anion binding capacity of the fiber, with respect to the weight of the fiber. 2. A method according to claim 1, wherein the method is used in an amount of 2 to 15%. 4. The method according to claim 1, wherein the treatment is carried out using a water-soluble alkali metal salt whose anion has a molecular weight of 90 or more. 5. The method according to claim 1, wherein the treatment is carried out using a water-soluble alkali metal salt or sulfuric acid, an alkylsulfonic acid, an arylsulfonic acid or an alkylsulfuric acid, or an alkylene oxide addition product thereof. 6. The method according to claim 1, wherein the treatment is carried out using sodium sulfate. 7. After the dye has been absorbed, the fiber is treated separately with a chromating agent and a water-soluble compound in any order.
The method described in section. 8. After the dye has been absorbed, the fiber is treated in one reaction step with a chromating agent and a water-soluble compound.
The method described in section.