EP0284010B1 - Process for alkali-free dyeing and printing - Google Patents

Abstract

Process for alkali-free dyeing and printing with reactive dyes. Beforehand, the textile material is treated with a wetting agent and a reaction product of polyethyleneimine and a bifunctional alkylating agent. This is followed by dyeing with reactive dyes in a conventional manner but without the addition of alkali to fix the dyes.

Description

The dyeing of textile materials, such as fabrics, knitted fabrics or yarns and threads, consisting of or containing cellulose fibers with reactive dyes, can be carried out according to known methods in that the textile material is drawn out with a dyeing liquor containing reactive dye, usually at elevated temperature and in most commercially available reactive dye types in the presence of alkali, or continuous or discontinuous processes, such as the so-called pad-steam process, or the cold retention process can be used. In the pad-steam process, as well as in the cold dwell process, the textile material is first padded with a reactive dye liquor, the alkali required for fixation being usually applied in a separate impregnation step. In the pad-steam process, the dye fixation is then carried out by a steaming process, in the cold residence process by docking the impregnated goods and lingering for several hours at room temperature. Other fixation options, such as The treatment of the goods, which have been sealed with an alkali-free reactive dye liquor, using sodium hydroxide solution / water glass solution has become known and is practiced industrially.

In all of the reactive dyeing processes mentioned, a covalent chemical bond between the dye molecule and the cellulose molecule is produced in the course of the dyeing process. This type of dye is thus chemically anchored to the fiber.

Theoretically, reactive stains on cellulose should have very high wet fastness properties. In practice, however, it turns out that this is not the case. The reasons for this are of different types and may not yet be known in its entirety. However, it can be said that a more or less large proportion of the reactive dye used for dyeing does not react with the cellulose fiber, but with water molecules. When reacting with water, the reactive dye loses its chemical binding ability to the cellulose and is only bound to the fiber molecule by secondary valence forces.

This phenomenon in the practical implementation of the dyeings ultimately leads to the fact that dyeings of reactive dyes on cellulose fibers only have high wet fastness properties if they are subjected to thorough washing after the dyeing process. The technical effort for this aftertreatment practically reaches the actual dyeing process. In particular, large amounts of water are required for the post-wash and it is often necessary to connect not just a single but several wash cycles in succession in order to achieve the desired high wet fastness of the dyeings. The complexity and the high technical and financial expenditure associated with the washing operations have led to the fact that detailed studies have been carried out on the washing-out mechanism of residual dyes. The publication by Dipl.-Chem. F. Somm and Text.-Ing. (grad.) R. Buser "Influence of various parameters on the washout behavior of reactive dyes" in Textil-Praxis International from July 1982.

There has also been no lack of attempts and proposals to facilitate the washing out of the dye residues or to increase the wet fastness of dyeings without having to increase the washing out effort.

DE-A-29 10 583 discloses a soaping aid for dyeings and prints on textile materials, which is based on the use of an alkali aluminum silicate, optionally in combination with polyvinylpyrrolidone.

The problem of removing the portions of the hydrolyzed reactive dye which are inherently water-soluble due to their substantivity to the cellulose fiber by secondary valence forces and thus improving the wet fastness of the dyed goods is also already described in DE-A-27 47 358 and DE -A-28 43 645 has been taken up. According to the recommendation of DE-A-27 47 358, polyamines, polyamides or polyurethanes and polyureas should be used for this purpose. According to DE-A-28 43 645, alkoxylated polyamines such as e.g. alkoxylated polyethyleneimine can be used.

To solve a similar problem, namely the improvement in the wet fastness of substantive dyeings, DE-B-1 111 144, BE-A-625 711 and US Pat. No. 3,334,138 treat the dyeings with basic polyguanidine compounds and known with polymeric quaternized, nitrogen-containing compounds.

Another possibility known from the prior art for improving the wet fastness of noun dyeings consists in aftertreatment with condensation products of cyanamide, formaldehyde and salts of organic amines or ammonium salts.

Japanese patent application 53-675 relates to the aftertreatment of vat dyeings for the purpose of improving the authenticity. However, the technical problem here differs significantly from that of post-treatment of reactive dyeings.

It has now been found that cellulose material can be dyed and printed with reactive dyes without the use of alkali if it is pretreated with a wetting agent and an optionally quaternized reaction product of polyethyleneimine with a bifunctional alkylating agent, then dyed with reactive dyes by conventional methods, but without alkali and the dyeings are completed by rinsing, soaping and drying.

The auxiliary agent required for the pretreatment is known from US-A-4,588,413. The aid is used there exclusively for the aftertreatment of dyeings with reactive dyes. Pretreatment with this aid and subsequent dyeing without alkali is not described there. A method exclusively for the aftertreatment of reactive stains with compounds of a similar structure is also described in GB-A-2006279.

worin

X

ein Rest der Formel -(CH₂-CH₂-NH)_c-H ist,

a

und b unabhängig voneinander Zahlen von 0 bis 600 sind, wobei die Summe a + b eine Zahl von 50-600 ist und

c

eine Zahl von 0 bis 50 ist.

The polyethyleneimine required to produce the pretreatment agent to be used according to the invention corresponds to formula I.

wherein

X

is a radical of the formula - (CH₂-CH₂-NH) _c -H,

a

and b are independently numbers from 0 to 600, the sum a + b being a number from 50-600 and

c

is a number from 0 to 50.

This means that the polyethyleneimine used is a molecule in which -NH₂,> NH and -N <building blocks are present, which are linked together by ethylene groups are linked. In total, the polyethyleneimine contains about 50 to 600 ethyleneimine units. In conventional commercial products, primary, secondary and tertiary nitrogen functions are in a numerical ratio of approximately 1: 2: 1.

In dieser Formel bedeutet A den Rest eines alkylierenden Agens und Z entweder eine direkte Bindung oder ein zweiwertiges Brückenglied.In principle, all known bifunctional alkylating agents can be used for the reaction with the ethyleneimine of the formula I. Such known bifunctional alkylating agents correspond to formula II

$\text{A - Z - A (II)}$

In this formula, A is the residue of an alkylating agent and Z is either a direct bond or a divalent bridge member.

bedeutet und Z, sofern es keine direkte Bindung ist, für einen zweiwertigen geradkettigen oder verzweigten Rest der Formel III



        -C_nH_2n-   (III)



worin n eine Zahl von 1 bis 4 ist, einen zweiwertigen Rest der Formel IV



        -C_mH_2m-D-C_mH_2m-   (IV)



worin m die Zahlen 1 oder 2 bedeutet und D für -O-, -S-, -NH-, -CO-, -SO-, -SO₂-, oder für Phenylen steht.Those bifunctional alkylating agents of the formula II in which A is a group of the formula -CH₂-Y, in which Y is a substituent which can be split off as an anion, in particular chlorine, bromine, iodine or -OH or are particularly suitable for the reaction with the polyethyleneimines to give auxiliaries to be used according to the invention a group which can be split off as an anion, in particular the sulfato group or a sulfonyloxy group, in particular phenylsulfonyloxy or p-tolylsulfonyloxy, or the epoxy group

means and Z, if it is not a direct bond, for a divalent straight-chain or branched radical of the formula III



-C _n H _2n - (III)



wherein n is a number from 1 to 4, a divalent radical of the formula IV



-C _m H _2m -DC _m H _2m - (IV)



wherein m represents the numbers 1 or 2 and D represents -O-, -S-, -NH-, -CO-, -SO-, -SO₂-, or phenylene.

Preferred for the reaction with polyethyleneimine to be used according to the invention are those bifunctional alkylating agents in which A are groups of the formula -CH₂-Y which are linked to one another via a bridge member of the formula IV, or those in which one of the radicals A is a group of Formula is -CH₂-Y, which is bonded directly to an epoxy group.

Examples of such bifunctional alkylating agents are epichlorohydrin, glycid, 1,3-dichloropropan-2-ol, β, βʹ-dichloro-diethyl ether, β-βʹ-dichloro-diethylamine, β, βʹ-dichloro-diethyl sulfide, β, βʹ- Dichloro-diethylsulfoxide, β, βʹ-dichloro-diethylsulfone, β, βʹ-disulfatoethyl ether, β, βʹ-diphenylsulfonyloxyethyl ether, meta- or para-diepoxyethylbenzene, meta- or para-diepoxypropylbenzene, diepoxybutane, diepoxy-2-methylbutylamine, diepoxy.

To produce the pretreatment agents to be used according to the invention, the polyethyleneimine and the bifunctional alkylating agent are reacted with one another in a weight ratio of 100: 0.01 to 100: 2.0, preferably from 100: 0.1 to 100: 1.0.

It can be assumed that this reaction involves the installation of crosslinking bridging links between the polyethyleneimine chains. An external indication of this is that the viscosity of the aqueous solutions during the transition from uncrosslinked polyethyleneimine to the product crosslinked by the bifunctional alkylating agent increases significantly. In principle, the polyethyleneimine can be reacted with the bifunctional alkylating agents without a solvent. In view of the better possibility of controlling the reaction and the more favorable heat dissipation, it is expedient to carry out the reaction in the presence of an inert solvent. Both organic solvents in which the reactants are soluble, such as, for example, lower alcohols, and in particular water, are suitable for this. The reaction can be carried out in the temperature range between -10 and about 100 ° C. The implementation in the environment of normal room temperature, ie in the range between 15 and 45 ° C., is particularly advantageous. This results in a reaction process with good control options, very good product quality and the lowest possible energy consumption. The reaction is essentially completed in about 1 to 2 hours.

In order to obtain aids to be used according to the invention which have particularly narrow-tolerance specifications, i.e. In order to achieve particularly good reproducibility of the production process, it is advantageous, after the main reaction has ended, for the reaction mixture to have a defined pH between 9 and 10 for several hours, usually 2 to 6 hours, at elevated temperature, advantageously between 60 and 100 ° C afterwards.

The reaction products of polyethyleneimine used according to the invention with a bifunctional alkylating agent can optionally also be quaternized with C₁-C₄-, preferably C₁-C₃-alkyl groups. The quaternization can be carried out using alkyl halides, preferably alkyl chlorides, or dialkyl sulfates by known methods.

This aid described above is applied to the textile material to be dyed or printed together with a wetting or padding aid from an aqueous liquor which is customary in the textile industry. Alkane sulfonates, dialkyl sulfosuccinates, dialkyl phosphates or propylene oxide / ethylene oxide block polymers with a proportion of 40-80% by weight of ethylene oxide are used as such wetting or padding aids, but especially non-ionic compounds, for example oxyethylated Nonylphenol. Raw or pretreated cotton or mixed fabrics containing cotton are suitable as textile materials. The process according to the invention is particularly interesting for the pretreatment of cotton warp yarns with the aid described in the size. After weaving with untreated weft yarns and then alkali-free over-dyeing with reactive dyes, a denim effect is then achieved after washing out the fabric.

The pretreatment with the auxiliary together with a nonionic wetting agent is carried out from an aqueous liquor by customary methods by padding or in the exhaust process at temperatures of approximately 20 to 70 ° C., preferably 40 to 60 ° C., in the size from 80 ° C. to cooking temperature. The liquor is adjusted to a weakly acidic pH, preferably pH 6. The amount of auxiliary is about 3 to 10%, preferably 3 to 8%, based on the weight of the goods. The amount of wetting agent is preferably 2 to 4 g / l. The pretreatment liquor is then squeezed off and the goods are dried.

The goods pretreated in this way are then dyed with reactive dyes using customary methods and on customary dyeing units, for example using the cold dwell method or using an exhaust method. The Fleet ratio can be about 1: 3 to 1:40. However, it is important here that, in contrast to the previously customary procedure, no alkali is used in the present case. Suitable reactive dyes in this process are all known types of reactive dyes which contain groups which are reactive with the hydroxyl groups of cellulose and which, under the dyeing conditions described according to the invention, preferably react by reaction with the polymers described and fixed on the cellulose material. The reactive groups are, for example, groups with easily removable substituents which leave an electrophilic residue, such as reactive groups of the vinylsulfone type, groups of the ring systems quinoxaline, phthalazine, triazine, pyrimidine or pyridazone substituted with halogen atoms or reactive groups substituted with alkylsulfonyl groups in the case of sulfonylpyrimidothiazole or sulfonylbenzylbenzene . Specifically, dyes with the reactive groups β-sulfatoethylsulfone, β-chloroethylsulfone, β-thiosulfatoethylsulfone, β-phosphatoethylsulfone, chlorotriazinylamino, dichlorotriazinylamino, chlorotriazinyldiamino, trichloropyrimidylamino, dichloropyrimidylamino, dichloropyridylamino, dichloropyridylamino amino, 2-methylsulfonylbenzthiazol-6-yl-amino, 2,3-dichloroquinoxalin-6-yl-carbonylamino or 4-chloro-5-methyl-2-methylsulfonylpyrimid-3-yl-amino.

Suitable basic dye bodies of the reactive dyes are, for example, water-soluble azo, disazo, formazan, anthraquinone, dioxazine or phthalocyanine dyes. Water-soluble azo and disazo reactive dyes, which can also be metal complex reactive dyes, are preferably used. After dyeing, the goods are finished by rinsing, possibly soaping and drying.

The process according to the invention can be carried out not only with reactive dyes, but also in the same way with other types of dyes which contain anionic, for example sulfo groups, such as, for example, direct dyes, acid dyes and water-soluble sulfur dyes. Similar effects and fastness properties are achieved with these dyes as with the reactive dyes. In addition, pigment dyes such as vat and sulfur vat dyes can also be used in the process.

The method according to the invention is not only suitable for dyeing textile material, but also for printing. Here, the textile material is printed with a printing paste which contains a marking dye and the auxiliary agent to be used according to the invention. After drying and fixing, the textile material is then over-dyed with reactive dyes without alkali, preferably using the pad-steam process or the exhaust process. Another possibility is that the cotton chains or cotton fabrics preheated with the aid described are printed with a printing paste which contains the reactive dye but no alkali and then the dyeing, for. B. fixed by steaming at 102-105 ° C for 8 minutes. The subsequent post-treatment is carried out analogously to the dyeings.

The main advantage of the process according to the invention is that no alkali is required as a result of the pretreatment with the auxiliary described in the subsequent dyeing. When the goods are finally washed out after dyeing, no alkali then goes into the wastewater, so that the salt pollution of the wastewater in the dyeing plants is significantly reduced. In addition, the pretreatment described also partially results in a significant color deepening of the color compared to a coloration with the same amount of reactive dye in one conventional dyeing process. Among other things, water glass is used to a large extent as the alkali for fixing the reactive dyes. If this water glass is not carefully washed out after fixing, it can lead to annoying SiO₂ deposits on the goods and thus impair the grip. This disadvantage is also eliminated in the method according to the invention. This new process also makes washing out the unfixed dye residues easier by dispensing with alkali, since in the presence of alkali the cotton fiber swells and the unfixed dye is more strongly absorbed. This does not apply to the method according to the invention. The solubility of the reactive dyes, which is severely restricted by the alkali, is significantly improved and the stability of the neutral dye liquors is increased.

The dyeings produced by the process according to the invention described above show good wet fastness properties.

Surprisingly, it was found that a washing process immediately following the soaping process with detergents containing perborate significantly increases the brilliance of the dyeings and the weft thread, which has not been dyed or, depending on the color shade, is slightly soiled, so that a dyeing with high brilliance and white weft yarn is obtained. The use of optical brighteners in the wash liquor further increases the brilliance of the dyeings and the weft yarns.

These effects are achieved in particular when the washing is carried out between 20-50 ° C., preferably between 40-50 ° C. If you wash with the perborate-containing detergent at higher temperatures, for example 50 ° to 100 ° C., preferably 85 ° to 100 ° C., the denim dyeing can be lightened gradually until the fabric is completely decolorized. In this way, uneven coloring or fashionable color changes are achieved in a way that is very gentle on the fibers (stone wash effect). This effect can otherwise only be achieved with alkaline hypochlorite solutions and possibly with washing in the presence of pumice stones.

The amount of alkali perborate in the detergents is between about 4 and 25% by weight. Such detergents containing perborate, which are suitable here, are described in detail in "Tenside" 18, p. 246 (1981). Two formulations are described below as examples:
1.
anionic / nonionic surfactants 10 - 25%
Soaps, (alkali salts of fatty acids) 0 - 10%
Polyphosphates 20 - 50%
Sodium / or potassium perborate 10 - 25%
Na silicate 3 - 10%
Carboxymethyl cellulose 1 - 2%
Neutral salts and adjusting agents 5 - 20%
optical brighteners 1 - 2%
2nd
Soap 35 - 50%
Tetrapropylene benzene sulfonate
Fatty alcohol sulfate
Fatty acid ethanolamide
Na carbonate 14 - 18%
Na water glass 6 - 10%
Na diphosphate 5 - 8%
Na triphosphate
Na perborate 4 - 6%
Magnesium silicate 1 - 3%
Opt. Brightener 0.03%
Carboxymethyl cellulose
Perfume oil

example 1

Cotton warp yarns are treated as follows on a sizing machine in the trough provided:
40 g / l polyvinyl alcohol (PVA)
5 g / l polyethylene glycol
4 g / l di-2-ethylhexyl phosphate potassium salt
100 g / l polyethyleneimine condensation product according to the example in Table 1, last line of patent application EP-A-0 133 933
Fleet absorption 100-120% (high-performance crushers).

The yarn runs at a speed of 60 m / min, the liquor temperature is 80-90 ° C.
After leaving the sizing trough, the cotton chains are dried with contact heat at approx. 130 ° C. Instead of PVA, modified starch or mixtures of modified starch and PVA can also be used. The use of carboxymethyl cellulose or carboxymethyl starch as a sizing agent is not possible, since this can lead to precipitation with the cationic alkali ethylene in the condensate. Then the cotton chains are woven with the weft of cotton and the fabric obtained is padded with a solution on a cold dwelling system consisting of dyeing pad and docking device, which solution, for example
10 g / l CI Reactive Blue 19 (CI No. 61200)
and 4 g / l wetting agent (ethoxylated nonylphenol)
contains.

The goods padded in this way are wrapped in an airtight manner on the dock with a polyethylene film and left to linger for up to 24 hours with rotation.
After the aftertreatment usual for reactive dyes by rinsing, boiling soap and rinsing again even without the amount of alkali normally required for fixing the reactive dyes, the chains are colored with good fastness properties. The pretreatment of these cotton chains with the polyethylenimine condensation product also results in a much deeper shade than with normal fixation with alkali. The shot practically turns white again after rinsing and soaping. A fabric with a denim effect is thus obtained.

Example 2

After the final rinsing and soaping process, the denim fabric sized and dyed as in Example 1 is treated with 5 g / l of a conventional detergent containing perborate (content of Na perborate 20% by weight) at 50-60 ° C. for 10 to 20 minutes .

This results in a much more brilliant shade of this denim fabric while maintaining the full strength and intensity of the dyeing. In addition, the white of the weft yarn is again significantly improved compared to a denim fabric dyed in the same way, but which has not been washed with a detergent containing perborate.

Example 3

Bleached cotton twill is treated in a 1:40 liquor with 4% of the polyethyleneimine condensation product as in Example 1 and 1 g / l of di-2-oxyethylated nonylphenol as follows: Start cold, raise the temperature uniformly to 40-50 ° in 20 min C and treated for a further 10 min at this temperature.

The liquor is then drained off, the cotton twill squeezed off and over-dyed with a liquor that only
1% by weight of Reactive Blue 77
contains.

The fleet ratio is 1:30. Dyeing is started cold, the temperature is raised uniformly to 60 ° C. in 30 minutes and dyeing is continued at 60 ° C. for another hour.
After the usual post-treatment by rinsing, soaping and rinsing, a strong turquoise blue shade is also obtained, which is much deeper than a corresponding pull-out dyeing with 1% dye, 50 g / l table salt or Glauber's salt, 3 ml / l NaOH 38 ° Bé and 5 g / l soda calc. was carried out.

Example 4

A bleached cotton fabric is placed on a 2- or 3-roll pad with a solution that
60 g / l of the polyethyleneimine condensation product as in Example 1
and 2 g / l di-2-ethylhexyl phosphate potassium salt
contains, padded cold and after drying padded with a liquor which
10 g / l Reactive Red 1 (CI no.18158)
and 2 g / l of a wetting agent (oxyethylated nonylphenol)
contains.

The dyeing is lingered and treated according to Example 1. A deep red color is obtained with good fastness properties. The corresponding cold dyed dye, which was stained with the normal amount of alkali (NaOH / water glass), on the other hand, shows only a pink shade. By adding about 10 g / l of an aqueous dispersion containing 3.5% acrylamide homopolymer and 4.5% caprolactam as a padding aid to the padding liquor, a clear absorption of dye liquor is additionally achieved.

Example 5

The denim fabric sized as in Example 1 is padded with a solution on a cold dwelling system consisting of dyeing pad and docking device
25 g / l Solubilized Sulfur Red 11
and 4 g / l wetting agent (ethoxylated nonylphenol)
contains.

After the dock has lingered for 12 to 24 hours, rinsing, possibly boiling soaping and rinsing is completed. Even without the alkali and reducing agents (e.g. Na₂S or NaSH) normally required for fixing the sulfur dyes, the chains are colored with good fastness to use and good lightfastness.

Claims (7)

1. A process for alkali-free dyeing and printing with reactive dyes, direct dyes, acid dyes, water-soluble sulfur dyes or pigment dyes, which comprises pretreating the textile material to be dyed with a wetting agent and a quaternized or unquaternized reaction product of polyethyleneimine with a bifunctional alkylating agent, then dyeing by conventional methods but without the use of alkali, and finishing by rinsing and drying.
2. The process as claimed in claim 1, wherein warp yarn is pretreated with a wetting agent and a reaction product of polyethyleneimine with a bifunctional alkylating agent in a size bath together with the size.
3. The process as claimed in claim 1, wherein the reaction product is preferably used in an amount of 3 to 10% on weight of fiber.
4. The process as claimed in claims 1 to 3, wherein a reaction product of polyethyleneimine with epichlorohydrin, 1,3-dichloropropan-2-ol or mixtures thereof is used.
5. The process as claimed in claims 1 to 4, wherein a reaction product of polyethyleneimine with a bifunctional alkylating agent in a reactant weight ratio of 100:0.01 to 100:2 is used.
6. The process as claimed in claim 1, wherein a polymeric padding assistant is added to the dye-pad liquor.
7. The process as claimed in claims 1 to 6, wherein the dyeings or prints are subsequently washed with a washing agent which contains a perborate with or without a perborate activator and optical brighteners.