EP0522395B1 - Use of anionic cellulose mixed ethers in textile printing - Google Patents

Description

The present invention relates to the use of anionic mixed cellulose ethers, preferably alkylsulfoalkylcellulose ethers, in particular methylsulfoethylcellulose ethers, as thickeners in textile printing.

The composition of printing pastes in the textile sector, regardless of the dye used, is determined by the type of printing, the substrate, the fixing and the application method. In addition to dyes and chemicals, all printing pastes contain thickeners. The thickenings have the task of giving the dye-containing, aqueous liquor a pumpable and printable consistency. On the one hand, it should be fluid and, on the other hand, it should be so immobile that it holds the dye in the place provided by the design and thus conveys a sharp contour. The thickener in the printing paste also takes on protective colloid and protective film functions. By regulating the moisture balance, it has a lasting influence on the color yield (P. Habereder, F. Bayerlein in: Handbuch der Textilhilhilmittel; Ed .: A. Chwala, V. Anger, Verlag Chemie, Weinheim, 1977, page 621). This results in a number of requirements for thickeners and thickeners:
Thickeners and the thickeners produced from them should have a long shelf life, with the addition of preservatives for economic and health reasons should be avoided as far as possible. In addition, thickenings must be compatible with the corresponding dyes and must not react with them. In order to avoid faulty prints, which could be caused by clogging of the stencils, gauze or rotary stencils, the thickenings must be free of fibers and gel bodies. In order to avoid poor print quality, hardening of the grip on the printed areas and time-consuming and costly post-treatment processes, thickenings must be easy to wash out. Finally, thickenings should be available in a standardized manner and be as cheap as possible, since they do not give the textile material a higher value, but are washed out again.

The majority of the thickeners used in textile printing are the alginates, which are generally used in concentrations of 3 to 4%. They are easy to wash out, compatible with a range of dyes and largely stable in the range from pH 4 to 10. Alginates are incompatible with heavy metal salts, calcium and aluminum compounds and with basic dyes. As a biopolymer, alginate is easily broken down by microorganisms.

Unprotected thickening usually lasts only 1 to 2 days, so that preservatives, preferably formaldehyde solutions, are added, but their use is extremely questionable due to their high risk potential.

When using thickeners in textile printing in warmer regions, very good temperature stability of the thickeners is required. When using alginates, quantitative decarboxylation can occur. The increasingly labor-intensive and cost-intensive process for producing the alginates obtained from seaweed is also reflected in high, significantly increased prices, so that inexpensive alternatives are sought.

Of the thickeners used in textile printing, xanthans, emulsion thickeners, synthetic polymer thickeners and carboxymethylated polysaccharides are also of importance, but all of them are a number of Have disadvantages so that the desired effects cannot be achieved with a single thickener alone. For example, printing with emulsion thickening is falling sharply for reasons of price and ecology. In addition to their high costs, xanthans have insufficient stability against microbial degradation. Polymer thickeners are extremely sensitive to electrolytes, making them susceptible to hard water, anionic dyes and leveling agent salts.

In recent years there has been no lack of attempts to use polysaccharides, in particular sodium carboxymethyl cellulose (Na-CMC), as thickeners in textile printing. The commercially available sodium carboxymethyl celluloses generally only have degrees of substitution (DS values) from 0.3 to 1.4 (GI Stelzer, ED Klug, in: Handbook of Water Soluble Gums and Resins, ed .: RL Davidson McGraw-Hill, New York, 1980, pages 4-1). Because of the low degree of substitution, their use as a thickener leads to reactions with the reactive dye, so that poor color yields and handle hardening result. In order to prevent a possible reaction between the thickener and the reactive dye, specialties with degrees of substitution (DS) of 2.0 or higher are therefore used (DE-A-3 208 430, JP-A-5 9192-786).

Carboxymethyl celluloses are soluble in cold and hot water, which, in addition to being easy to wash out, offers procedural advantages. Because of the simple viscosity settings, good prints can also be achieved at higher machine speeds (HB Bush, HB Trost, Hercules Chem., 60 , 14 [1970]). However, aqueous carboxymethyl cellulose solutions are easily broken down by microorganisms. Furthermore, their poor salt stability, in particular with respect to polyvalent cations and their ability to react with the dyes (direct dyes), is a considerable disadvantage. Attempts have therefore been made to add stability to electrolytes by adding borates during the alkalization (EP-A-0 055 820), mixed etherification or increasing the degree of substitution (DE-A-3 303 153, US Pat. No. 4,426,518) and bacteria and to improve the compatibility with dyes.

The products produced in this way, which are almost completely etherified by a multi-stage procedure, lead to a significantly improved property profile of carboxymethyl cellulose (CMC). However, such highly substituted products require a repeated repetition of the alkalization and etherification step, which, viewed over all stages, results in very poor substitution yields, which makes complex and costly production processes necessary. (K. Engelskirchen, in Houben-Weyl's "Macromolecular Substances", Vol. E20 / III, Georg Thieme Verlag, Stuttgart, 1987, pp. 2072-2076).

It was therefore an object of the present invention to provide mixed cellulose ethers as thickeners, dispersants or binders for the textile industry which have excellent qualities, ie very good solubility properties and do not have the disadvantages of the thickeners currently used in textile printing
The anionic cellulose mixed ethers which can be used in textile printing according to the present invention, preferably alkyl sulfoethyl cellulose mixed ethers, in particular methyl sulfoethyl cellulose mixed ethers, have degrees of substitution with respect to sulfoethyl of DS = 0.01 to 0.9, have an average total degree of substitution of DS> 1 and can, for example, according to DE -A-3 742 104, DE-A-4 113 892 or DE-A-3 742 106.

• 1. Ausgezeichnete Elektrolytstabilität, insbesondere gegenüber mehrwertigen Kationen, insbesondere Calciumionen.
• 2. Sehr gute Säure-, Alkali- und Temperaturstabilität.
• 3. Sehr gute Stabilität gegenüber mikrobiellem Abbau aufgrund homogener Veretherung der Cellulose.
• 4. Optimale Farbstoff-Fixierung durch sehr gute Auswaschbarkeit (Griff) des Verdickungsmittels und praktisch vollständige Abgabe des Farbstoffes an das Substrat.
• 5. Verbesserte drucktechnische Eigenschaften, wie Egalität und Standschärfe durch gel- und faserfreie Losungsqualität.
• 6. Sehr gute Verträglichkeit mit Farbstoffen und Chemikalien durch hohen Gesamtsubstitutionsgrad.
• 7. Problemlose Produktion der Celluloseether in großem Maßstab.
• 8. Einfache Technologie der Herstellung von Cellulosederivaten in Pulver- oder Granulatform.
• 9. Gute Umweltverträglichkeit der Celluloseether.

The gel and fiber-free cellulose derivatives thus produced, characterized by the measuring method described below, are distinguished by excellent solution quality and can be used as thickeners, dispersants or binders in the textile industry and show the following compared to the thickeners currently used in the textile industry Advantages:

• 1. Excellent electrolyte stability, especially with respect to polyvalent cations, especially calcium ions.
• 2. Very good acid, alkali and temperature stability.
• 3. Very good stability against microbial degradation due to homogeneous etherification of the cellulose.
• 4. Optimal dye fixation through very good washability (handle) of the thickener and practically complete release of the dye to the substrate.
• 5. Improved printing properties such as levelness and sharpness due to gel and fiber-free solution quality.
• 6. Very good compatibility with dyes and chemicals due to the high degree of total substitution.
• 7. Trouble-free production of cellulose ethers on a large scale.
• 8. Simple technology of manufacturing cellulose derivatives in powder or granule form.
• 9. Good environmental compatibility of cellulose ethers.

The anionic cellulose mixed ethers used according to the invention have excellent qualities and are soluble in water both as purified and unpurified (technical) products without gel bodies and fibers and have average overall degrees of substitution of 0.5 to 2.5, in particular> 1.

The mixed cellulose ethers used have viscosities of 5 to 80,000 mPa · s, in particular 100 to 30,000 mPa · s (measured in 2% by weight aqueous solution at a shear rate of D = 2.5 s⁻¹ at 20 ° C ) and have transmission values of more than 95%, in particular more than 96% (measured on a 2% by weight aqueous solution in a cuvette with an optical path length of 10 mm with light of the wavelength λ = 550 nm).

According to the invention, the anionic mixed cellulose ethers produced by one of the processes listed above are used as thickeners in printing pastes in textile printing.

In the examples listed below, the effect of various methylsulfoethyl celluloses used according to the invention as a thickening agent in textile printing is compared with a commercially available sodium alginate (Lamitex M 5, from Protan / Norway). Sodium alginate was compared as a 6% solution and MSEC as a 1.8, 2.1, 2.6 and 4.5% solution, whereby in the printing paste sodium alginate with 3.3 and MSEC with 1.0, 1, 3, 1.6 and 2.9% were used. The laboratory printer printed on different qualities of cotton and rayon wool with different print images (full-surface printing, contour printing, wet-on-wet printing process, nuance printing), different colors and variations of the fixing conditions. The solutions (thickener, strain, printing paste) were checked over a longer period (sometimes up to 8 weeks) with regard to their stability, their rheology and their color fastness.

In order to avoid faulty prints, the methylsulfoethyl celluloses used according to the invention are checked for their filterability prior to their application test in textile printing. The flow rate per unit time of an MSEC solution of a defined concentration produced under defined conditions is suctioned off by a polyethylene filter material with a defined mesh size and at a given negative pressure. A Kotthoff mixing siren "Model M 52" with 15 spokes and mixing head insert, a temperature bath (T = 25 ° C, Haake D 8), a vacuum pump, a suction device made of metal and an upper pan scale (accuracy: ± 1 g) were used as the device. made of metal The polyethylene gauze was of the type PE 74 (0.074 mm) (mesh size) "Estal Mono".

The MSEC sample to be tested is dispersed with the Kotthoff mixing siren at 2,800 rpm for 3 minutes without loss. The quantities of MSEC used in the air-dry state and tap water of 25 ° C are specified in Table 1 for each viscosity level. After the dispersing time is 5 minutes 1 400 rpm further stirred. The resulting solution is then stored in a temperature bath of 25 ° C (± 0.1 ° C) for 1 hour. Table 1 Amount of MSEC used depending on the viscosity level Nominal viscosity [mPa · s] Use of sample [g] / tap water [g] 2,000 30th 970 5,000 20th 980 10,000 15 985 20,000 13 987 30,000 11.5 988.5 40,000 10th 990

After the tempering time has elapsed, the test solution is stirred with the Kotthoff mixing siren - 1 minute at 1400 rpm. Then 500 ml (500 g) of the test solution are transferred to the funnel of the suction apparatus. The specified amount of test solution is drawn off through the polyethylene gauze at a vacuum of 0.67 bar.

As a test result, the measured filtration time for 500 ml of MSEC solution by the filtration apparatus described at 0.67 bar negative pressure is given. If the throughput time is more than 3 minutes, the test is terminated, stating the remaining amount of test solution in the test result. The methylsulfoethyl celluloses (examples MSEC 1-4) produced by the process according to the invention and used in textile printing have throughput times of <10 s due to their excellent solution quality.

Table 2 shows the characteristic data of the thickeners MSEC 1-4. Table 2 Characteristic data of the thickeners MSEC ¹⁾ DS-SE ²⁾ DS-Me ²⁾ Viscosity ³⁾ [mPa.s] 1 0.44 0.90 5500 2nd 0.76 0.88 900 3rd 0.50 0.80 13000 4th 0.46 1.22 20000 ¹⁾ Methylsulfoethyl cellulose ²⁾ DS-SE = Average degree of substitution by sulfoethyl groups DS-Me = Average degree of substitution by methyl groups see. also: K. Balser, M. Iseringhausen, in Ullmann's Encyclopedia of Industrial Chemistry, 4th Edition, Volume 9, Verlag Chemie, Weinheim, 1983, pp. 192-212 ³⁾ viscosity; 2% by weight aqueous solutions with a rotary viscometer (Haake), type RV 100, system M500, measuring device MV, according to DIN 53 019, at a shear rate of D = 2.5 s⁻¹ (T = 20 ° C)

The composition of the stock thickenings produced with MSEC 1-4 and Lamitex M5 is shown in Table 3, that of the printing pastes is shown in Table 4. The influence of the shear rates on the viscosity (pseudoplastic behavior) of the stock thickenings or printing pastes can also be seen from the tables.

The printing pastes used for reactive dyes consist of thickeners, urea, alkali and oxidizing agents. Mixtures of commercially available reactive dyes are used as dyes: Cibacron® yellow, Cibacron® red and Cibacron® blue (Ciba-Geigy); 90 parts of the respective stock thickenings (A, C, E, G, I) are combined with 0.577 parts of a dye mixture (for composition, see Table 4) and distilled water. Table 4 Printing pastes Printing paste composition pH Viscosities ¹⁾ [m Pa · s] at 2.5 rpm 20 rpm 100 rpm 1. 90 parts A + 10 parts Cibacron Blue 3 R liquid (40%) 10.8 6,000 4,000 3,040 2. 90 parts B + 10 parts Cibacron Blue 3 R liquid (40%) 11.1 8,800 6,200 3,880 3. 90 parts C + 10 parts Cibacron Blue 3 R liquid (40%) 11.1 5,200 3,800 2,540 4. 90 parts D + 10 parts Cibacron Blue 3 R liquid (40%) 11.1 7,600 5,500 4,020 5. 90 parts E + 10 parts Cibacron Blue 3 R liquid (40%) 11.1 4,000 3,300 2,600 6. 90 parts F + 10 parts Cibacron Blue 3 R liquid (40%) 11.1 10,400 6,100 3,220 7. 90 parts G + 10 parts Cibacron Blue 3 R liquid (40%) 11.1 6,400 3,900 2,200 8. 90 parts H + 10 parts Cibacron Blue 3 R liquid (40%) 11.1 11,200 6,700 3,340 9. 90 parts I + 10 parts Cibacron Blue 3 R liquid (40%) 11.1 7,200 4,300 2,320 1) Viscosity: Brookfield RVT, spindle 6, at variable revolutions per minute (rpm)

Table 5 shows the storage stability of the stock thickenings at room temperature using viscometric measurements (Brookfield RVT, spindle 6, 20 rpm). The pH stability and the viscosity stability of the printing pastes Brookfield RVT, spindle 6, 20 rpm) are shown in Table 6. Table 5 Storage stability of the stock thickening at room temperature Trunk thickening Viscosities ¹⁾ [mPa · s] right away after 3 days after 1 week after 2 weeks after 4 weeks A 7,000 4,300 2,700 1,900 1,100 C. 5,300 4,100 3,800 3,200 2,000 E 5,000 4,000 4,000 3,800 3,100 G 4,700 3,600 3,300 2,900 2,000 I. 5,300 4,300 4,300 3,700 2,200 1) Brookfield RVT, spindle 6, 20 rpm

e (gebleicht), Cotton-Viskose-Cretonne (gesenkt, abgekocht, gebleicht, laugiert), Cotton-Viskose-Cretonne (gesenkt, abgekocht, gebleicht) verwendet. Das Textilgut wird bei ca. 90°C getrocknet Bei der Sattdampffixierung (100 bis 102°C) beträgt die Dämpfzeit 8 Minuten (Mathis-Trockner). Das Substrat Cotton-Schussatin wird darüber hinaus durch Trockenhitze (Heißluft) fixiert (1 Minute bei 200°C, Mathis-Trockner). Der Auswaschprozeß erfolgt in drei Stufen:

• ◇ gründliches, kaltes Spülen,
• ◇ Behandlung in der Nähe der Kochtemperatur (10 Minuten),
• ◇ kaltes Spülen.

Different substrates are printed with finished printing pastes from Table 4. Since the dye-cellulose bond and the achievement of deep, brilliant and clear prints are favored by well-prepared material, the various substrates are pretreated differently. A 64 T stencil (rectangles) and a doctor blade with a diameter of 8 mm are used for the printing process (Magnetic level 6, speed level 3). Cotton, weft satin (mercerized, bleached), Cotton-Renfor are used as substrates

e (bleached), cotton-viscose cretonne (lowered, boiled, bleached, lye), cotton-viscose cretonne (lowered, boiled, bleached) used. The textile is dried at approx. 90 ° C. With steam fixation (100 to 102 ° C) the steaming time is 8 minutes (Mathis dryer). The cotton-shot satin substrate is also fixed by dry heat (hot air) (1 minute at 200 ° C, Mathis dryer). The washout process takes place in three stages:

• ◇ thorough, cold rinsing,
• ◇ treatment near the cooking temperature (10 minutes),
• ◇ cold rinse.

The results of the different printing processes are shown in Tables 7 to 10.

The superiority of the MSEC used in textile printing and claimed according to the invention can be clearly seen from the value tables listed below.

The technical terms used in the tables are known to the cellulose or textile printing specialist and do not require any further explanation. In this connection, reference is made to the chapters "textile printing" and "textile dyeing" in Ullmann's Encyclopedia of Industrial Chemistry, vol. 22, pages 565 ff and page 635 ff (Verlag Chemie, Weinheim, 1982). Table 11 Examplary comparison between a conventional thickener used in textile printing (sodium alginate, company Protan / Norway) and an anionic cellulose mixed ether (methylsulfoethyl cellulose ether [MSEC]) Alginate MSEC * 1. Preservation (formaldehyde) absolutely necessary unnecessary 2. Rheology Good Good 3. Storage stability of the thickening bad, despite formaldehyde excellent (8 weeks) 4. Storage stability stock thickening bad, despite formaldehyde excellent (8 weeks) 5. Storage stability of printing paste bad, despite formaldehyde excellent (8 weeks) 6. Nuance stability bad, despite formaldehyde excellent (8 weeks) 7. pH stability Good Good 8. NaCl stability Good Good 9. Calcium stability very bad, Calgon T required excellent, no Calgon T required 10. Acid constancy bad Good 11. Alkali resistance Good Good 12. Shear stability Good Good * MSEC = production according to DE-A-37 42 104 DS _SE = 0.44, DS _OCH3 = 0.90

Table 12 Comparison of the printing properties between sodium alginate (Protan / Norway) and a methylsulfoethyl cellulose mixed ether (MSEC) Printing properties Alginate MSEC * 1. Cotton, mercerized Good Good 2. Cotton, normal Good Good 3. Viscose, leached Good outstanding 4. Viscose, not leached Good outstanding 5. Equality (cotton, viscose) Good Good 6. Stability Good Good 7. Handle (washable) Good Good 8. Cotton penetration Good Good 9. Penetration viscose Good Good 10. Print wet / wet (cotton / viscose) Good Good 11. Nuance (cotton, viscose) Good outstanding 12. Reproducibility bad Good * = MSEC according to DE-A-37 42 104 DS _SE = 0.44, DS _OCH3 = 0.90

Claims (5)

1. Use of anionic cellulose mixed ethers as thickeners or rheology improvers in textile printing.
2. Use according to claim 1, characterised in that the anionic cellulose mixed ethers are alkylsulphoethyl celluloses, in particular methylsulphoethyl cellulose (MSEC).
3. Use according to one of claims 1 or 2, characterised in that the thickener additionally contains starch, modified starch, sodium alginate, a gum of natural origin and/or carboxymethyl cellulose or mixtures thereof.
4. Use according to one of claims 1 to 3, characterised in that union fabric, natural fibres or regenerated cellulose are used as the textile materials.
5. Use according to one of claims 1 to 4, characterised in that oxidation dyes, sulphur dyes, anionic dyes, developed dyes, wool chrome dyes, substantive dyes, copper dyes, metallic complex dyes, dispersion dyes, pigments, but in particular reactive dyes are used as the dyes.