EP0062865B1 - Dyeing process - Google Patents

Description

The present invention relates to a new process for single-bath, single-stage dyeing of textile materials consisting of wool and cellulose fibers with highly reactive reactive dyes after an exhaust process, in which the textile material in the presence of one or more reactive dyes and one or more neutral salts slowly from alkaline to acidic falling pH and at the same time slowly rising temperature is treated.

Previous dyeing methods for dyeing textile materials consisting of wool and cellulose fibers with reactive dyes were essentially based on two principles. Either it was first stained in the acidic pH range and then neutralized by adding alkalis or switched to the weakly alkaline range or it was first stained in the alkaline range and then by adding acids or rinsing and diluting with fresh water from alkaline to slightly acidic or changed to neutral. Both methods are energy and time consuming or require large amounts of fresh water as well as manual support of the dyeing process by the dyer.

With the aid of the method according to the invention, it is possible for the first time to dye textile materials consisting of wool and cellulose fibers with a reactive dye under the same pH and temperature conditions, which results in an improved appearance, improved rinsing out of the dye hydrolyzate, improved fastness properties and a significantly simplified process Adding shading dye with dye corrections entails. Furthermore, the yields in the dyeing process according to the invention are extremely high.

• (1) Eintauchen der Fasern in das Färbebad bei einem pH-Wert, bei welchem noch keine Farbstoffixierung auf der Faser eintritt,
• (2) Einstellung des Färbebades auf eine im wesentlichen konstante Temperatur ohne pH-Änderung,
• (3) Halten des Färbebades bei dieser Temperatur und Einstellung des pH-Wertes auf einen Wert, bei welchem ein praktisch vollständiges Aufziehen des Farbstoffs geschieht. Diese pH-Einstellung geschieht durch allmähliche Zugabe bestimmter Säure- oder Basenmengen.
• (4) Halten des Färbebades bei praktisch konstanter Temperatur, um praktisch vollständige Reaktion des Farbstoffs und der Faser zu ermöglichen.

GB-A-1 458 632 describes a process for dyeing natural or synthetic fibers with dyes, the drawing of which on the fibers is pH-dependent and which are fixed at a specific pH, the following stages being carried out:

• (1) immersing the fibers in the dyebath at a pH at which no dye fixation occurs on the fibers,
• (2) adjusting the dyebath to an essentially constant temperature without changing the pH,
• (3) keeping the dyebath at this temperature and adjusting the pH to a value at which the dye is virtually completely absorbed. This pH adjustment is done by gradually adding certain amounts of acid or base.
• (4) keeping the dyebath at a practically constant temperature to allow the dye and fiber to react almost completely.

In claim 2 of GB-A-1 458 632 an alkaline starting dye bath is listed as a preferred embodiment, which is made acidic by the gradual addition of doped amounts of acid, with the dye then being virtually completely fixed in the acidic medium.

The addition of a neutral salt to the dyebath is not mentioned in the British patent in question.

The teaching of GB-A-1 458 632 clearly leads away from the subject matter of the present application.

The aim of the present invention is namely to optimally dye tone-in-tone a textile material consisting of wool and cellulose fibers in an economically justifiable time.

Dyes are used to dye wool and cellulose fibers at the same time. These are reactive dyes having a Mindesthydrolysekonstante of 0,8-10- ² min -.1 (all disclosed in the application text reactive dyes satisfy this condition). The fiber mixture sometimes begins to color even at the alkaline starting pH.

After the initial pH value and the initial temperature of the dyebath have been set and, if necessary, maintained for some time under these conditions, a synchronous lowering of the pH value and an increase in temperature of the dyebath finally occur in the presence of neutral salt. Under these conditions, the wool / cellulose blended fabric is optimally colored.

According to FR-A-1 512 665, the dyeing of cellulose fibers or of cellulose / polyester mixed fibers at temperatures above 100 ° C. is known. These temperatures can only be reached in closed dyeing machines.

This high temperature is set immediately and at this temperature hydrogen chloride is released from the halogenated organic compound contained in the dyebath, the pH shifting from the alkaline to the weakly acidic range. The aim of FR-A-1 512 665 is primarily the dyeing of cellulose / polyester mixed fibers, the dye bath containing reactive and disperse dyes. In the method according to the invention, temperatures of max. 100 ° C reached. In practice one works at final temperatures of approx. 95 ° C.

The extreme conditions of the process according to FR-A-1 512 665 would be unsuitable for dyeing wool / cellulose fiber mixtures, so a uniform coloring would not be possible.

The usable reactive dyes in the present process have a hydrolysis constant of at least 0,8.10- ² 2 min-1 at pH 11 and 40 ° C. (For the determination of the hydrolysis constant, see D. Hildebrand in: The Chemistry of Synth. Dyes, Vol. VI, 1972, 346 ff, Academic Press, Inc. New York and London).

Suitable reactive dyes are, above all, sulfo-containing, water-soluble, organic dyes from the series of anthraquinone, azo, azo metal complex, formazane, oxazine and phthalocyanine dyes.

The reactive dyes preferably contain at least one 2,3-dichloroquinoxalinyl, dichlorotriazinyl, monofluorotriazinyl, monofluoropyrimidinyl or difluoropyrimidinyl radical as the reactive group.

The reactive dyes specified in the application examples are listed as examples.

Suitable alkalis for the process according to the invention for adjusting the starting pH are those which, alone or in a mixture, give a pH of 10 to 11. Examples include sodium hydroxide solution, trisodium phosphate, soda, disodium phosphate, sodium bicarbonate and calcium hydroxide. In particular, so much alkali is added that the dye liquor assumes a pH of 9 to 11. This is the starting pH of the process according to the invention. An alkaline buffer mixture (in particular phosphate buffer) is preferably used to adjust the starting pH.

The dye liquor contains 20 to 150 g / l, preferably 50 to 100 g / l of a neutral salt such as sodium sulfate or sodium chloride, and 0.5 to 2 g / l, preferably 1 to 1.5 g / l of a leveling agent. If necessary, further dyeing aids such as wetting agents (e.g. alkyl phosphates), defoamers (e.g. mineral or silicone emulsions) or eluents (e.g. ethoxylated fatty acid amides) may be included.

Examples of suitable leveling agents are those described in DE-B-1 619 530.

Leveling agents such as those mentioned in DE-B-1 258 817 are also suitable.

The leveling agents which can preferably be used in the process according to the invention belong to the class of ethoxylated amines or amine oxides.

In the process according to the invention, the pH of the dye liquor is changed by adding an agent which eliminates acid in the alkaline dye liquor or by slowly metering in acid.

The acid can be added in the form of the free acid (e.g. acetic acid) or an acidic salt.

Possible acid releasing agents are: Water-soluble derivatives of organic or inorganic acids, which release acids when heated in an alkaline medium and thus the pH value of the dye bath, which has an alkaline reaction at the beginning of the fixing process, in the weakly acidic range up to a pH value of 6 -5 convict. This pH of 6-5 is the final pH of the process according to the invention.

• Natriumchloracetat
• Natriumdichloracetat
• Na-Salz der 3-Chlorpropionsäure
• Monochloracetamid, Butyrolacton
• Halbester der Schwefelsäure wie Laurylsulfat, Hexadecylsulfat oder Octadecylsulfat sowie vorzugsweise 2-Ethylhexylsulfat, Butylsulfat, sowie die Schwefelsäureester von oxyethylierten und oxypropylierten Alkoholen wie z. B. Butylglykolsulfat, Butyldiglykolsulfat, ferner C₁―C₄-Alkylester der Phosphorsäure oder phosphorigen Säure, C_i-C₄-Alkylester von Phosphon- und Phosphinsäuren, wie z. B. Trimethylphosphat, Triethylphosphat, Tris-(hydroxyethyl)-phosphat, Dimethylphosphat, Diethylphosphat, Dipropylphosphit, Di-isopropyl-phosphit, Diethylphosphit, Dipropylphosphit, Di-isopropylphosphit, Dibutylphosphit, Methanphosphonsäuredimethylester, Ethylphosphonsäurediethylester, Phosphonopropionsäuretrimethylester, Cyanethanphosphonsäuredimethylester, Cyanmethanphosphonsäuredimethylester, Hydroxyethan- und Hydroxymethanphosphonsäuredimethylester, 2-Chlor-ethanphosphonsäuredimethylester, 2-Chlorethanphosphonsäurediethylester und Phosphonooberbernsteinsäure-tetramethylester.

Examples of acid donors are:

• Sodium chloroacetate
• Sodium dichloroacetate
• Na salt of 3-chloropropionic acid
• Monochloroacetamide, butyrolactone
• Half esters of sulfuric acid such as lauryl sulfate, hexadecyl sulfate or octadecyl sulfate and preferably 2-ethylhexyl sulfate, butyl sulfate, and the sulfuric acid esters of oxyethylated and oxypropylated alcohols such as. B. butyl glycol sulfate, butyl diglycol sulfate, further C ₁ ―C ₄ alkyl esters of phosphoric acid or phosphorous acid, C _i -C ₄ alkyl esters of phosphonic and phosphinic acids, such as. As trimethyl phosphate, triethyl phosphate, tris (hydroxyethyl) phosphate, dimethyl phosphate, diethyl phosphate, dipropyl phosphite, di-isopropyl phosphite, diethyl phosphite, dipropyl phosphite, di-isopropyl phosphite, dibutyl phosphite, dimethyl methanephosphonate, Ethylphosphonsäurediethylester, Phosphonopropionsäuretrimethylester, Cyanethanphosphonsäuredimethylester, Cyanmethanphosphonsäuredimethylester, and hydroxyethane Hydroxymethanphosphonsäuredimethylester , Dimethyl 2-chloroethanephosphonate, Diethyl 2-chloroethanephosphonate and tetramethylphosphonosuccinate.

If the process is carried out in such a way that the acid required for changing the pH is metered in, then the addition of acidic salts (preferably monosodium phosphate or sodium bisulfate) is suitable.

• Das Textilmaterial wird mit einer Flotte behandelt, welche folgende Bestandteile enthält:
  

The process according to the invention is generally carried out as follows:

• The textile material is treated with a liquor which contains the following components:
  

If the acid is gradually added to the bath by dosing, use approximately 10% solutions of the acid salts.

The dyeing bath is preferably set at 40-60 ° C and brought to about 30-60 minutes Temperature stability within 40-50 minutes to boiling temperature, and _^1/2 to 1 hour at this temperature out (ca. 100 ° C). The liquor is then drained off, the dyed fabric is rinsed with water and soaped with an aqueous ammonia solution. In general, soaping with 2 g / l of a 25% aqueous ammonia solution on fresh bath for 150-200 minutes at 80 ° C.

The parts given in the following examples are parts by weight in all cases.

example 1

besteht.100 parts of a wool / cotton blended yarn consisting of 60 parts of wool and 40 parts of cotton are treated in the form of a cheese on a yarn dyeing machine with a 45 ° C warm liquor, which consists of

consists.

After 60 minutes, the mixture is heated to the cooking temperature at 1 ° / minute and treated at this temperature for a further 60 minutes. The liquor is then drained off and aftertreated with 2 parts of a 25% commercial ammonia solution in 1000 liquors at 80 ° for 20 minutes.

A deep scarlet dyeing with good fastness properties and a tone-like dyeing of both fiber components is obtained.

If the same parts of the dye 11 are used instead of the dye I, a deep, uniform yellow coloration is obtained.

Example 2

besteht.100 parts of a wool / cotton blended yarn, consisting of 80 parts of cotton and 20 parts of wool, are treated in the form of a package on a yarn dyeing machine with a 45 ° C warm liquor, which consists of

consists.

It is treated for 1 hour at 45 ° C. and then a solution of 3.5 parts of mono-sodium phosphate in 31.5 parts of water is slowly run in over one hour while heating to boiling temperature. After the cooking temperature has been reached, it is treated for a further hour at this temperature. Then the liquor is drained and rinsed cold and hot with fresh water.

After draining off the rinsing liquor, the mixture is soaped at the boil for 20 minutes using a liquor containing 2 parts of 25% ammonia per 1000 parts.

A level brown coloration with good fastness properties is obtained.

Example 3

besteht.100 parts of a wool / cotton blended yarn consisting of 50 parts of wool and 50 parts of cotton are treated on a tree dyeing machine at 40 ° with a liquor which consists of

consists.

Otherwise, the procedure is as described in Example 1.

You get a deep black color. If 5 parts of dye III are used instead of the mixture of dyes III, VI and VII, a uniform navy blue coloration is obtained.

Claims (8)

1. Process for dyeing textile materials consisting of wool and cellulose fibres in one bath and in one step by the exhaustion principle, characterised in that the textile material is treated in the presence of one or more reactive dyestuffs, each having a hydrolysis constant of at least 0.8 x 10-² min -¹ (hydrolysis constant at pH 11 and 40° C) and in the presence of one or more neutral salts at a pH value falling slowly from pH 9-11 to pH 5-6 and at a simultaneously slowly increasing temperature.

2. Process according to Claim 1, characterised in that the dyeing is carried out in the presence of 20 to 150 g of a neutral salt per litre of dye liquor.

3. Process according to Claim 1 or 2, characterised in that the neutral salt is sodium sulphate or sodium chloride.

4. Process according to Claim 1 to 3, characterised in that the lowering of the pH value is carried out in the presence of an acid donor.

5. Process according to Claim 1 to 4, characterised in that the amount of acid required for lowering the pH is gradually metered into the dye liquor pre-buffered at pH 9-11.

6. Process according to Claim 1 to 5, characterised in that the pH change is accompanied by a defined temperature increase starting from about 40 to 60° C to the boiling temperature of the dyebath.

7. Process according to Claim 1 to 6, characterised in that the lowering of the pH value is carried out in the presence of an acid salt.

8. Process according to Claim 1 to 6, characterised in that the dye liquor contains, per litre of dye liquor, 0.1 to 8 g of a reactive dyestuff, 0.5 to 2 g of a levelling agent, 0 to 2 g of other dyeing auxiliaries, 20 to 150 g of a neutral salt, 1 to 8 g of an alkaline buffer and 1 to 8 g of an acid donor.