EP0554748B1 - Utilization of anionic alkyl carboxymethyl cellulose ether mixture in textile printing - Google Patents

Description

According to the invention, the use of anionic alkyl carboxymethyl cellulose mixed ethers and in particular methyl carboxymethyl cellulose mixed ethers (MCMC) is claimed as an auxiliary in the textile industry, preferably as a thickener 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, 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. Regulating the moisture balance it has a lasting effect on the color yield (B. Habereder, F. Baierlein in: Handbuch der Textilhilfsmittel; publisher: 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, and the addition of preservatives should be avoided as far as possible for health and economic reasons. In addition, thickenings must be compatible with the corresponding dyes and must not react with them.

Reactive dyes have, for example, those reactive groups which react under the dyeing conditions with the substrate in the presence of alkalis and fix the dye via a covalent bond (H. Zollinger, Angew. Chem. 73 , 125 (1961)). Thickeners which have a similar structure to the substrate to be colored are normally unsuitable because they are able to react with the reactive dyes.

The use of cellulose, starch and locust bean flour derivatives, gum arabic, tragacanth and the like. therefore usually leads to hardening of the handle, poor color yields and sometimes insufficient fastness properties.

For faulty prints caused by clogging of the stencils, gauze or rotating stencils could, to avoid, the thickening must be completely free of fibers and gels. 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 alginates (Ciba-Rundschau, No. 1, 19-34 (1969)), which are generally used in concentrations of 3 to 4%. The alkali salts of alginic acids have the advantage that they can be washed out very well. Alginates are compatible with a range of dyes and are largely stable in the pH range from 5 to 10. At higher pH values, transeliminative depolymerizations are observed (A. Hang et al., Acta Chem. Scand. 21 , 2859 (1967)). Alkaline alginates are incompatible with heavy metal salts, calcium and aluminum compounds, which necessitates the use of complexing agents. 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 or phenols, are added, but their use is extremely unsafe due to the high risk potential.

A very good temperature stability of the thickeners is required for the use of thickenings in textile printing in warmer regions. 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 alternative options are sought.

Of the thickeners used in textile printing, xanthans, emulsion thickeners and synthetic polymer thickeners are also important, but they all have a number of disadvantages, so that the desired effects cannot be achieved with a single thickener alone. For example, the pressure with emulsion thickening declines 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 celluloses (Na-CMC), alone or as compoundings, as thickeners in textile printing (EP-A 0 106 228, DD-A-158 403). The commercially available sodium carboxymethyl celluloses usually have only degrees of substitution (DS values) from 0.3 to 1.4 (GI Stelzer, ED Klug in: Handbook of Water Soluble Gums and Resins, publisher: RL Davidson, McGraw Hill, New York, 1980, page 4-1) . Due to the low degree of substitution, their use as thickeners leads to reactions with the reactive dye. This results in poor color yields and hardened handles. The reactive dyes thus inactivated are also frequently embedded in the substrate (P. Bajaj et al. In: J. Macromol, Sci., Rev. Macromol. Chem. 1984, C 24 (3), 387 ff). These non-covalently bound dyestuff portions have to be removed by intensive washing in order to achieve good wet fastness properties. In order to prevent a possible reaction between the thickener and the reactive dye, specialties with degrees of substitution (DS) around or above 2.0 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 adjustment, good prints can be achieved, even at higher machine speeds (HB Bush, HB Trost, Hercules Chem., Volume 60, 14 (1970)). However, the commercially available carboxymethyl cellulose solutions are easily broken down by microorganisms. Furthermore, their poor salt stability, in particular with respect to polyvalent cations (calcium ions) and their ability to react with the dyes (reactive dyes) is a considerable disadvantage. Attempts have therefore been made to change etherifications by changing the alkalization (EP-A-0 055 820) (SU-A-794 098, EP-A 0-A-319 865) or increases in the degree of substitution (DE-A-3 303 153, US-A-4 426 518) the stability to electrolytes and bacteria and the compatibility with To improve dyes.

The products, which are almost completely etherified due to the 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 necessitates complex and cost-intensive production processes (K. Engelskirchen, in Houben-Weyls "Macromolecular Substances", Vol. E 20 / III, Georg Thieme Verlag, Stuttgart, 1987, pp. 2072 to 2076). Mixed etherifications lead to improved stability towards electrolytes, but coagulation cannot be definitely ruled out (W. Hansi in: Dtsch. Farben Zschr. 25 , 1971, p. 493 ff).

The object of the present invention was therefore to provide such cellulose mixed ethers as thickening, dispersing or binding agents for the textile industry which have excellent qualities, ie very good solubility properties and do not have the disadvantages of the thickening agents currently used in textile printing.

Surprisingly, it has now been found that alkyl carboxymethyl cellulose mixed ethers, in particular methyl carboxymethyl cellulose mixed ethers, do not have the salt sensitivity known for carboxymethyl cellulose, in particular towards polyvalent cations.

The anionic alkylcarboxymethyl cellulose mixed ethers which can be used in textile printing according to the present invention, in particular methyl carboxymethyl cellulose mixed ethers, have degrees of substitution with respect to carboxymethyl of DS = 0.01 to 1.9, in particular DS = 0.1 to 1.6, and have an average total degree of substitution of DS 1 , 3-2.2, in particular 1.5 to 2.0. The teaching of making these connections can e.g. from the following patents: US-A-2 476 331, GB-A-659 506, US-A-2 510 153, SU-A-384 828, DE-A-3 303 153, DD-A-140 049 or IM Timokhin et al., Izv. Vyssh., Ucheb. Zaved. Neft, Gaz, 16 (11), 31-5 (1973).

• 1. Ausgezeichnete Elektrolytstabilität durch Mischveretherung, insbesondere gegenüber mehrwertigen Kationen, insbesondere Calcium-Ionen.
• 2. Sehr gute Säure-, Alkali- und Temperaturstabilität.
• 3. Sehr gute Stabilität gegenüber mikrobiellem Abbau durch hohen Gesamtsubstitutionsgrad des Celluloseethers und ausgezeichnete Verträglichkeit mit Farbstoffen und Chemikalien.
• 4. Gute Farbstoff-Fixierung und praktisch vollständige Abgabe des Farbstoffes an das Substrat.
• 5. Verbesserte drucktechnische Eigenschaften, wie Egalität und Standschärfe durch gel- und faserfreie Lösungsqualität.
• 6. Problemlose Produktion der Celluloseether im großen Maßstab mit im Vergleich zu alginat-konstanter Qualität.
• 7. Einfache Technologie der Herstellung von Cellulosederivaten in Pulver- oder Granulatform.

The gel and fiber-free cellulose derivatives characterized by the measuring method described below are distinguished by an excellent solution quality and can be used as thickening, dispersing or binding agents in the textile industry, in particular in textile printing. They have the following advantages over the thickeners currently used in the textile industry, especially in textile printing:

• 1. Excellent electrolyte stability through mixed etherification, in particular with respect to polyvalent cations, in particular calcium ions.
• 2. Very good acid, alkali and temperature stability.
• 3. Very good stability against microbial degradation due to the high degree of total substitution of the cellulose ether and excellent compatibility with dyes and chemicals.
• 4. Good dye fixation 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. Trouble-free production of cellulose ethers on a large scale in comparison to alginate-constant quality.
• 7. Simple technology of producing cellulose derivatives in powder or granule form.

The anionic alkyl carboxymethyl cellulose mixed ethers used according to the invention have excellent qualities and are free of gel bodies and fibers in water, both as purified and unpurified (technical) products soluble. The products have average overall degrees of substitution of 1.3-2.2, in particular 1.5-2.0.

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

The alkyl carboxymethyl cellulose mixed ethers used according to the invention are notable for very good water solubility. The products have a small, insoluble fraction, determined by centrifugation (20 min at 2,500 g), which is below 1%, in particular below 0.5%.

The anionic cellulose mixed ethers prepared by one of the processes listed above are preferably used as thickeners in printing pastes in textile printing.

For example, cellulose or regenerated cellulose, polyester, wool, silk, nylon, polyamides or blended fabrics are used as substrates. It can be any materials that can be printed with the corresponding dyes.

The print paste composition can be applied by any printing and dyeing process, e.g. by manual application, block, portrait, jet, stencil, flat or rotary film printing etc. conventional printing or dyeing processes.

The printing inks are fixed in the heat after the printing paste has been applied to the substrate. The substrate is then washed, dried and optionally subjected to further treatment processes.

In the examples listed below, the effect of a methylcarboxymethylcellulose (MCMC) used according to the invention as a thickener in textile printing is compared with a commercially available sodium alginate (Lamitex® M 5, from Protan / Norway). Sodium alginate as a 6% solution and MCMC as a 3.4% solution were compared. It was printed using a laboratory printer on various cotton qualities (flat film printing) with different colors and variations of the fixing conditions.

In order to avoid faulty prints, which could result from blockage of the stencils, gauze or rotary stencils, the methylcarboxymethyl cellulose (MCMC) used according to the invention is examined for its transmission or its water-soluble fraction in textile printing according to the above-mentioned method. Table 1 shows the characteristics of the MCMC used.

In comparison to Lamitex M 5, the thickening formulation was examined for its pseudoplastic behavior (Table 2) Table 2 Thickening approaches / structural viscosity (permutite water) product Concentration (%) PH value Viscosity (Brookfield RVT, spindle 6) [mPas] 2.5 20 (rpm) 100 Lamitex M 5 ¹⁾ 4.7 6.5 12,000 10,000 6,690 MCMC 3.4 9.0 14,800 10,300 5,370 1) Lamitex-M-5 batch contains an addition of 5 g / kg Calgon T and 5 g / kg formalin (37%)

The influence of calcium ions was determined by adding a 73.9% by weight calcium chloride solution to 200 g of a 1% by weight solution of the respective thickening batch. Lamitex M 5 and carboxymethyl cellulose (CMC) coagulate even when small amounts of calcium chloride solution are added. Despite the high degree of substitution by carboxymethyl groups, the MCMC is surprisingly stable to calcium ions (Table 3). Table 3 MCMC alginate-CMC / influence of CaCl₂ Addition of CaCl₂ solution ¹) [ml] Electrolyte stability of MCMC ⁴) Alginate ²) CMC ³) 0.1 Coagulation stable stable 0.5 Coagulation stable stable 1.0 Coagulation stable stable 1.65 Coagulation Coagulation stable 2.0 Coagulation Coagulation stable 4.0 Coagulation Coagulation stable ¹) 73.9 wt .-% CaCl₂ solution. Add to 200 g of a 1% by weight solution of the thickening batch ²) Lamitex M5 ³) CMC, DS-carboxymethyl = 1.5; Viscosity of a 2% by weight aqueous solution 470 [mPa.s] (D = 2.5 s⁻¹, 20 ° C) ⁴) MCMC (see Table 1)

Table 4 and 5 show the influence of NaCl and that of changes in pH on the viscosity of the MCMC. Table 4 MCMC alginate-CMC / influence of NaCl NaCl addition per kg Viscosity change MCMC (3.4%) (%) Alginate ¹⁾ (4.7%) (%) + 1 g / kg - 1.7 + 6.4 + 5 g / kg ± 0 + 6.4 + 10 g / kg ± 0 + 6.4 1) Lamitex M 5

Table 5 MCMC alginate / pH influence pH change with pH change from pH 9 (MCMC) or pH 6.5 (alginate) Viscosity change MCMC (3.4%) (%) Alginate (4.7%) (%) Tartaric acid 6 - 6th + 2 Tartaric acid 5 - 6th + 6 Tartaric acid 4th - 9 + 7 Tartaric acid 3rd - 6th + 95 NaOH 10th - 2.4 - 7th NaOH 11 - 2.4 - 10th NaOH 12th - 2.4 - 10th

The storage stabilities of the thickeners MCMC and alginate at 20 ° C and 40 ° C were checked by appropriate viscosity measurements. The results are shown in Table 6. Table 6 Storage stability of alginate and MCMC compared Measurement Viscosities (mPa.s) MCMC¹) Alginate²) 20 ° C 40 ° C 20 ° C 40 ° C right away 10,941 10,941 10,929 10,929 after 1 week 10,643 9,926 12,183 6,343 after 2 weeks 10,320 8,122 10,284 5,626 after 4 weeks 9,854 5,303 3,261 3,583 after 8 weeks 9,245 2,616 108 Sediment; not a measurable solution 1) 3% by weight aqueous solution (rotary viscometer; D = 2.5 s⁻¹, 20 ° C) 2) 4.2% by weight aqueous solution (rotary viscometer; D = 2.55⁻¹, 20 ° C)

The composition of the stock thickenings produced with Lamitex M 5 and the MCMC is shown in Table 7, that of the printing pastes is shown in Table 8. Table 7 Compositions of the trunk thickening Thickening components Trunk thickening ¹⁾ A B C. D Lamitex M 5 (6%) 580 - - - MCMC (3.4%) - 600 675 750 Lyoprint® RG 11 11 11 11 urea 110 110 110 110 Na₂CO₃, calc. Sol., 1: 4 85 85 85 85 Permutite - water 211 191 116 41 Lyoprint AP® 3rd 3rd 3rd 3rd PH value 10.9 10.9 10.9 10.9 Viscosity ²⁾ (mPa.s) 5800 3000 4500 7100 1) Information in parts by weight 2) Brookfield RVT, spindle 6, 20 rpm

Table 8 Printing pastes Printing paste compositions pH Viscosity ¹⁾ (mPa.s) 1. 90 parts strain A + 10 parts Cibacron Blue 3 R liquid (40%) 10.9 4,100 2. 90 parts of strain B + 10 parts of Cibacron Blue 3 R liquid (40%) 10.9 2,200 3. 90 parts strain C + 10 parts Cibacron Blue 3 R liquid (40%) 10.9 3,500 4. 90 parts strain D + 10 parts Cibacron Blue 3 R liquid (40%) 10.9 5,200 (Parts = parts by weight) 1) Viscosity: Brookfield RVT, spindle 6, 20 rpm

• a) gründliches, kaltes Spülen,
• b) Behandlung in der Nähe der Kochtemperatur (10 min),
• c) kaltes Spülen.

Different substrates were printed with the finished printing pastes specified in Table 8. Since the dye / cellulose bond and the achievement of deep, brilliant and clear prints are favored by well prepared material, the different substrates were pretreated differently. A 64-T stencil (rectangles) and a squeegee with a diameter of 8 mm were used to assess strength, nuance, penetration, grip and levelness (magnetic level 6, speed level 3 and 10, respectively). A 68-T template and a Squeegee with a diameter of 6 mm used (magnetic level 6, speed level 3). Cotton weft satin (mercerized, bleached) and Cotton Renforce (bleached) were used as substrates. The textile was dried at 90 ° C. for about 5 minutes. With saturated steam fixation (100 to 102 ° C) the steaming time was approx. 8 min (interval, Mathis). The cotton-shot satin substrate was also fixed by dry heat (hot air) (approx. 1 min at 200 ° C, Mathis). The washout process was carried out in three stages:

• a) thorough, cold rinsing,
• b) treatment near the cooking temperature (10 min),
• c) cold rinse.

The results of the different printing processes are shown in Tables 9 to 11.

The superiority of the MCMC used in textile printing and claimed according to the invention can be seen from the table of values 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, volume 22, pages 565 ff and 635 ff (Verlag Chemie, Weinheim, 1982). Table 12 Exemplary comparison between a conventional thickener used in textile printing (sodium alginate, Lamitex M 5 (Protan / Norway)) and the methyl carboxymethyl cellulose (MCMC) used according to the invention Alginate MCMC ¹⁾ 1. Preservation absolutely necessary unnecessary 2. Rheology Good Good 3. Storage stability of the thickening bad, despite formaldehyde outstanding 4. Storage stability stock thickening bad, despite formaldehyde outstanding 5. Storage stability of printing paste bad, despite formaldehyde outstanding 6. Nuance stability bad, despite formaldehyde outstanding 7. pH stability Good Good 8. NaCl stability Good Good 9. Calcium stability very bad, Calgon T necessary excellent, no Calgon T required 10. Alkali resistance sufficient Good 11. Acid resistance sufficient Good 12. Shear stability Good Good 1) Degree of substitution by carboxymethyl groups: 0.97;
Degree of substitution by methyl groups: 0.96

Claims (7)

1. The use of anionic cellulose mixed ethers based on alkyl carboxymethyl cellulose as thickeners and flow promoters in textile printing.
2. The use of methyl carboxymethyl cellulose mixed ethers as thickeners and flow promoters in textile printing.
3. The use claimed in claim 1 or 2, characterized in that the alkyl carboxymethyl cellulose has transmission values of more than 95% and, more particularly, more than 96% (as measured on a 2% by weight aqueous solution in a cell with an optical path length of 10 mm with light having a wavelength λ of 550 nm) and a water-soluble component of > 99% and, more particularly, > 99.5%.
4. The use claimed in any of claims 1 to 3, characterized in that blended fabrics, natural fibres or regenerated cellulose are used as the textile materials.
5. The use claimed in any of claims 1 to 4, characterized in that oxidation dyes, sulfur dyes, anionic dyes, development dyes, wool chrome dyes, substantive dyes, but especially reactive dyes are used as the dyes.
6. Textile printing pastes, characterized in that they contain alkyl carboxymethyl cellulose as thickener and flow promoter.
7. Textile printing pastes as claimed in claim 6, characterized in that they contain methyl carboxymethyl cellulose.