WO2008003358A1

WO2008003358A1 - Combined demineralizing and de-sizing textile fiber materials

Info

Publication number: WO2008003358A1
Application number: PCT/EP2007/002356
Authority: WO
Inventors: Peter Weiler; Bernhard Seidl; Bettina Knauer
Original assignee: Dystar Textilfarben Gmbh & Co. Deutschland Kg
Priority date: 2006-07-05
Filing date: 2007-03-16
Publication date: 2008-01-10
Also published as: EP1876285A1

Abstract

The use of an aqueous, acidic medium for the combined dematerializing and de-sizing of textile fiber materials is described, the aqueous acidic medium comprising an acid-stable amylase and a complex-forming agent. Moreover, a method is described for the combined dematerializing and de-sizing of textile fiber materials, for which the aqueous, acidic medium is allowed to act on the textile fiber material.

Description

Combined demineralization and desizing of textile fiber materials

The invention relates to the use of an acidic aqueous medium comprising an acid-stable amylase and a complexing agent for the combined demineralization and desizing of textile fiber materials and a process for the combined demineralization and desizing of textile fiber materials, wherein the acidic aqueous medium is exposed to the textile fiber material leaves.

Textile fibers are provided with sizing in the course of the processing process in order to improve the machine-processability of the textile fibers. As sizing, various materials can be used, for example polyacrylates or cellulose derivatives, although for ecological reasons starch is often used for sizing. The starch may be, for example, potato, corn or rice starch.

Before further equipment, for example dyeing, it is advantageous to desize and demineralize the textile fibers. The desizing was previously carried out with dilute sulfuric acid, but the fibers have usually suffered damage, so that the enzymatic desizing with amylases has become established in the industry. Amylases are enzymes belonging to the group of hydrolases which break down starch into maltose or glucose either directly or via dextrins and occur in the digestive glands of humans and animals, in cereals, malt, bacteria and fungi. A distinction is made between .alpha.-, .beta.- and .gamma.-amylases, where .alpha.- and .beta.-amylases split 1, 4-glycosidic bonds, while .gamma.-amylases are also capable of splitting 1, 6-glycosidic bonds with the release of glucose. Industrial uses include amylases as additives in detergents, in the manufacture of beer, ethanol, confectionery and corn syrup, in screen and felt cleaning of papermaking machines, and desizing described above. Amylases are usually not stable in a strongly acidic medium (pH <5) and only in a pH range of about 6 - 9 active, so that the desizing of textile fibers so far in this pH range of about 6 - 9 was carried out.

In the demineralization of textile fibers especially alkaline earth metal ions and heavy metal ions are to be removed, to which customary Kornplexbiluner such as those based on carboxylic acids, phosphonates or phosphates are used. By contrast, these complexing agents are effective only in an acidic pH environment, so that the demineralization must take place in an acidic medium. As a result, demineralization and desizing of textile fibers has so far been carried out in two separate steps. Since the desizing is accompanied by a change in the pH and the enzymes used in the prior art for desizing have a narrow pH activity range in the vicinity of the neutral point of pH = 7, it was previously also required in the desizing larger amounts of buffer add.

Recent research has now also yielded acid-stable α-amylases, which are still stable and active at a pH below 6. Thus, US 6,100,073 describes the preparation, recovery and purification of an acid and thermostable α-amylase from Sulfolobus acidocaldarius. Seror and Antranikian describe in "Novel thermoactive glucoamylases from the thermoacidophilic Archaea Thermoplasma acidophilum, Picrophilus tordus and Picrophilus oshimae", Antonie van Leeuwenhoek, Vol. 81, No. 1-4, 2002, pp. 73-83 (11) the preparation, Recovery and purification of thermoacidophilic α-amylases from Thermoplasma acidophilum, Picrophilus torridus and Picrophilus oshimae. Schwermann et al. describe in Eur. J Biochem. 1994, 981-991 a thermoacidophilic α-amylase from Alicyclobacillus acidocaldarius. Ng, T.K. and Kenealy, WR (1986) disclose in "Industrial applications of thermostable enzymes", "Thermophiles, general, molecular and applied microbiology" (Brock, TD, ed.), pp. 197-215, John Wiley & Sons, New York, the production and recovery of fungal α-amylases from Aspergillus niger and Aspergillus orzyae. WO 2005/118800 A1 discloses an acid-stable α-amylase from Aspergillus kawachi.

The two-step process of demineralization and desizing and the use of large amounts of buffer to maintain the pH range of amylases in the desizing is generally very energy, resource and time consuming, requires the use of two separate liquors and large amounts of water, which in turn associated with appropriate amounts of wastewater, which must be disposed of in a time-consuming and costly manner.

The object of the present invention is therefore to provide a composition for the simplified demineralization and desizing of textile fiber materials without the disadvantages of Prior art and to provide a simplified process for the demineralization and desizing of textile fiber materials.

This object is achieved by using an acidic aqueous medium for combined, i. single-stage demineralization and desizing of texas fiber materials, wherein the acidic aqueous medium comprises an acid-stable amylase and a complexing agent. Further, this object is achieved by a process for the combined demineralization and desizing of textile fiber materials, in which an acidic aqueous medium is allowed to act on the textile fiber material, the acidic aqueous medium comprising an acid-stable amylase and a complexing agent.

Surprisingly, acid-stable amylases can be used in an aqueous medium together with complexing agents for combined demineralization and desizing. In particular, it was surprising that in combined, i. In a one-step demineralization and desizing step in an acidic aqueous medium using acid-stable amylases and complexing agents, the same degree of desizing could be achieved as in the conventional two-stage process of demineralization and desizing. Furthermore, it was surprising that the whiteness of the textile fiber materials is increased after the bleaching process carried out following the process according to the invention compared with the two-stage process of the prior art.

The use according to the invention of the acidic aqueous medium and the process according to the invention for the combined demineralization and desizing of textile fiber materials are distinguished by a high degree of desizing of the textile fiber materials after the treatment which is comparable to the degree of desizing of the two-stage process of the prior art and the use according to the invention and the invention Methods also have the advantage that a second energy, resource and time consuming step is saved. In addition, the whiteness of the textile fiber materials is increased after bleaching compared to the two-stage process of the prior art, which in turn brings with it the advantage that white textile fiber materials need not be re-bleached again and the dyeing, especially the color of light colors succeeds particularly well.

Acid-stable or acid-resistant amylases are understood in the context of the invention to be amylases which are stable in an aqueous medium at a pH of about 0-6, preferably 1-5, more preferably 1.5-4.8, ie within the Duration of use according to the invention or the duration of the method according to the invention of approximately 1 minute to 48 hours in the aqueous medium, so that the activity does not decrease below 50%, preferably not below 75%, more preferably below 90% of the initial activity at the same pH.

During the use according to the invention and the process according to the invention, the pH of the acidic aqueous medium acting on the textile fiber material increases. It is believed that this is due to the complexation of the alkaline earth metal ions and the heavy metal ions, which release hydroxides bound to the metal ions. The demineralization takes place in the use according to the invention and the process according to the invention primarily in the initial low pH range and the enzymatic desizing takes place primarily in the later higher but still acidic pH range. This is due to the fact that the acid-resistant amylases in the initially particularly low pH range are usually not sufficiently active in order to significantly advance the desizing. The amylases must therefore be stable in the initial low pH range, in which the complexation is particularly effective, while they can already partially develop their activity, and in the later higher, but still acidic pH range, the amylases must have sufficient Develop activity to facilitate the desizing within the exposure time. The demineralization and desizing are therefore controlled in the inventive use of an acidic aqueous medium by changing the pH controlled in a process step, d. H. single stage. Demineralization and desizing are thus carried out in concert, but usually staggered, with the activity profiles of the complexing agents and the amylases more or less overlapping, i. the maximums of the activity profiles are reached in succession, but the activity of the amylases can already increase in the region of the decaying activity curve of the complexing agents, so that in a transitional pH range the demineralization and the desizing run at speeds below the maximum more or less parallel.

According to the invention, the acidic aqueous medium is applied to the textile fiber material at a pH of 0-2.5, preferably 1-2, more preferably 1.5-1.9, for example the textile fiber material is impregnated in the acidic aqueous medium. After squeezing, a portion of the acidic aqueous medium remains on the textile fiber material and acts on it. As a rule, this results in a pH of 2.5-6, preferably 3-5, more preferably 3.5-4.8. The acidic aqueous medium used according to the invention therefore has a total pH of about 0-6 over the contact time. This pH of the acidic aqueous medium is preferably in the range from 1 to 5, more preferably in the range from 1.5 to 4.8, over the entire reaction time. As acid-stable amylases, acid-stable natural amylases from the digestive glands of humans and animals, from cereals, malt, bacteria, fungi or acid-stable amylases obtained or prepared by microbiological processes can be used. Preference is given to bacterial or fungal, ie derived from fungi amylases are used, in particular α- and ß-amylases, depending on the application, mixtures of several amylases can be used with advantage, for example if the sizings are composed inconsistently or to synergistic effects of the amylases use.

Particularly preferred are bacterial amylases, in particular bacterial α-amylases from the bacterial strains Bacillus licheniformis, Bacillus subtilis, Bacillus stearothermophilus, Sulfolobus acidocaldarius, Alicyclobacillus acidocaldarius, Thermoplasma acidophilum, Picrophilus torridus or Picrophilus oshimae and fungal amylases, especially fungal α-amylases from Aspergillus niger, Aspergillus oryzae, Aspergillus kawachi or Aspergillus sp. or a mixture of several of these amylases used and used in the inventive method. Mixtures of bacterial and fungal amylases can also be used. Particularly preferred are acid-stable bacterial α-amylases from Alicyclobacillus acidocaldarius and acid-stable fungal α-amylases from Aspergillus niger, Aspergillus oryzae and Aspergillus sp. used.

By complexing agents are meant all chemical compounds that can bind metal ions to form complexes. Suitable complexing agents which comprise the acidic aqueous medium used according to the invention are all inorganic and organic complexing agents which are capable of binding alkaline earth metal ions and / or heavy metal ions in an aqueous medium. An aqueous medium or medium in the sense of the present invention is understood to mean a liquid medium which is at least 50% by weight, preferably at least 75% by weight, more preferably at least 90% by weight and even more preferably at least 95% by weight. Contains% water.

Suitable complexing agents are in particular compounds which bind alkaline earth metal ions and heavy metal ions to form cyclic complexes (chelating agents). In this case, di-, tri-, tetra-, penta-, hexa- and multi-functional compounds come into consideration, in each case two functionalities equipped with lone pairs of electrons in 1, 2, 1, 3 or 1.4 position are. 1, 2-difunctional compounds form 5-rings in the complexation or chelation, whereas 1, 3-difunctional compounds form 6-rings and 1,4-difunctional compounds 7-rings. For example, compounds which are 1, 2 and 1, 3-diamino, 1, 2 and 1, 3-dicarbonyl, 1, 2 and 1, 3-dihydroxy, 1,2 and 1, 3 are suitable Hydroxycarbonyl, 1, 2 and 1, 3-hydroxyamino and 1,2 and 1, 3-aminocarbonyl groups contain. Furthermore, even cyclic compounds such as bipyrroles, bipyrrolidines, bipyridines and similar chelating agents can be used.

Preferred complexing agents are aminocarboxylic acids, phosphonates and polyacrylic acids and their copolymers, for example copolymers with maleic acid, or mixtures thereof.

Particularly preferred among the aminocarboxylic acids nitrilotriacetic acid,

Ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, methylglycinediacetic acid and modified anionic polyamines and among the phosphonates are 1-hydroxyethane- (1,1-diphosphonic acid) (HEDP) and its salts, amino-tris (methylenephosphonic acid) (ATMP) and its salts, diethylenetriamine penta (methylenephosphonic acid) (DTPMP) and its salts, ethylenediaminetetra (methylenephosphonic acid) (EDTMP) and its salts, hydroxyethylamino-di (methylenephosphonic acid) (HEMPA) and its salts, hexamethylenediaminetetra (methylenephosphonic acid) (HDTMP) and their salts and phosphonobutane-1,2,4-tricarboxylic acid (PBTC) and salts thereof are particularly preferred.

In order to optimize the aqueous acidic medium with regard to the complexing agent used and the acid-stable amylase used, the medium may additionally contain solubilizers, wetting agents, surface-active substances and / or organic solvents. For example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycols, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycols, ethylene-propylene glycols and alcohol polyglycol ethers, in particular fatty alcohol polyglycol ethers, as well as commercially available surfactants and detergents may be added. According to the invention, preference is given to using alcohol polyglycol ethers in which the saturated or unsaturated, branched or unbranched alcohol radical has 6 to 20, more preferably 12 to 18

Having carbon atoms, for example alcohol polyglycol ethers of lauryl alcohol,

Isotridecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol or mixtures of C _12-18

, Alcohols. The gycol ether radical of the alcohol polyglycol ethers is preferably composed of ethylene glycols and / or propylene glycols.

Particular preference is given to using alcohol polyglycol ethers of the formula nC _m H _{2m + 1} - (OCH ₂ CH ₂ ) _p - (OCH ₂ CHCH ₃ ) _q -OH individually or as mixtures in which m is 12, 13, 14, 15, 16, 17 or Is 18 and p and q can independently be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. Preferably, p and q are not both 0. Particularly preferred is the sum of p and q 4 to 16, in particular 6 to 14. Examples of particularly preferred alcohol polyglycol ethers are π-C _m H _{2m + 1} - (OCH ₂ CH ₂ ) - ( OCH ₂ CHCH ₃ ) -OH, n-CJH 2 H 2 O 2 H ₂ O ₃ M ₂ OCH ₂ OH

/ 7-C _m H _{2m + 1} - (OCH ₂ CH ₂ ) ₂ - (OCH ₂ CHCH ₃ ) ₂ -OH, nC _m H _{2m + 1} - (OCH ₂ CH ₂ ) - (OCH ₂ CHCH ₃ ) ₃ - OH, nC _m H _{2m + 1} - (OCH ₂ CH ₂ ) ₂ - (OCH ₂ CHCH ₃ ) ₃ -OH,

/ 1-CmH ₂ ^ i- (OCH ₂ CH ₂ HIGH ₂ CHCH ₃ ) _S -OH, nC _m H _2m , ₁ - (OCH ₂ CH ₂ ) ₂ - (OCH ₂ CHCH ₃ ) ₆ -OH. nC _m Hz _π ^ f-tOCHzCHzMOCHzCHCHaJβ-OH, where m = 12, 13, 14, 15, 16, 17 or 18. It can also be used mixtures of alcohol polyglycol ethers, for example a mixture of C ₁₂ H ₂₅ - (OCH ₂ CH ₂ ) ₁₂ - (OCH ₂ CHCH ₃ ) ₂ -OH and C ₁₀ H ₂ i- {OCH ₂ CH ₂ ) ₆ -OH.

For the preparation of the acidic aqueous medium used in the invention, the acid-resistant amylase and the complexing agent are placed under tubes in water or in a dilute aqueous salt solution, for example saline solution, optionally with the addition of further components that support demineralization and / or desizing. In order to ensure a sufficiently high efficiency of the acidic aqueous medium, the enzyme is added in an amount such that the enzyme activity concentration about 200,000 to 6,000,000 ISU (lodine-Starch-Activity Units) / ml at about 20 ⁰ C and a pH from about 3 to 4.5. Enzyme activity concentrations of 400,000 to 5,000,000 ISU / ml are preferred and enzyme activity concentrations of 600,000 to 4,000,000 ISU / ml are particularly preferred. The complexing agent should be present in order to ensure a sufficient effectiveness of the acid-resistant aqueous medium in a concentration of 0.1 to 100 mmol / l. The complexing agent is preferably present in a concentration of 0.1-75 mmol / l and more preferably in an amount of 0.1-50 mmol / l. Even more preferred are concentrations of 0.1-25 mmol / l.

Additionally, the aqueous acidic medium may contain conventional demineralization or desizing aids. Preferably, the aqueous acidic medium additionally contains one or more acids and / or one or more buffers as adjuvants to adjust and control the pH of the acidic aqueous medium so that demineralization and / or desizing proceeds effectively. For this purpose, a buffer can be used which allows the maintenance of a low pH value over a certain period of time in order to support the demineralization and / or a buffer can be used which ensures the retention of a later, higher pH in the acidic area over a period of time to assist in the desizing. In this way, the pH gradient of the acidic aqueous medium can be influenced and adapted to the desired use. The one or more buffers are advantageously designed to set a pH in the range of 0-6, preferably in the range of 1-5, more preferably in the range of 1.5-4.8. Suitable buffers for these pH ranges are, for example, phosphate buffers. For the purposes of the present invention, textile fiber materials are understood to mean all natural and synthetic fiber materials and their mixtures which can be processed textile. For example, the acidic aqueous medium comprising an acid-stable amylase and a complexing agent can be used according to the invention for the combined demineralization and desizing of acetate (CA), alginate (ALG) ₅ aramid (AR), asbestos (AS), cotton (CO), cupro ( CUP), Elastane (EL), Flax, Linen (LI), Guanaco (WU), Hemp (HA), Henequen (HE), Jute (JU), Kanin (WN), Kapok (KP), Kenaf (KE), Coco (CC), modacrylic (MAC), modal (CMD), polyacrylic (PAN), polyamide (PA), polyester (PES), polyethylene (PE), polypropylene (PP), polyvinyl alcohol (PVAL), ramie (RA), Rosella (JS), Silk (SE), Sisal (SI), Sunn (SN), Triacetate (CTA), Urena (JR), Vikunja (WG), Viscose (CV) and similar textile fibers. Preference is given to cellulose-containing fiber materials, in particular cotton and cotton blended fabrics.

In the use according to the invention and the method according to the invention, the textile fiber material may be in the form of a thread which has not yet been woven or the textile fiber material may be in the form of a woven product. The textile fiber material is preferably in the form of a woven product. It is particularly preferable to use cotton fabric and cotton blend fabric.

The process according to the invention can be carried out at a pH of the aqueous medium of 0-6, preferably 1-5, particularly preferably 1.5-4.8.

The suitable exposure time of the acidic aqueous medium to the textile desiccant for combined desizing and demineralization is determined by the thickness and structure of the sizings, the amount of alkaline earth metal ions and heavy metal ions to be complexed, the nature, texture and texture of the textile fiber material, the pH and the temperature of the fabric acidic aqueous medium, the complexing agent used and the amylase used and can be determined by the expert without difficulty in some orienting experiments. Usually, the exposure time is 1 minute to 48 hours. At lower temperatures, longer exposure times are generally selected, while shorter exposure times are sufficient at higher temperatures. In the cold-dwelling process, the exposure time is usually 8-48 h, in the warm-residence process 1-16 h and in the pad-steam process 1-10 min. Preferably, the above parameters are adjusted to the effect that the exposure time is in the range of 1 minute to 16 hours.

With respect to the other possible or preferred embodiments of the method according to the invention, reference is made to the above statements on the embodiments of the inventive use which are possible in the same way in the method according to the invention or preferred. In particular, it is also preferable in the method of the present invention that the acidic aqueous medium comprises 600,000 to 4,000,000 ISU / ml of acid-stable α-amylase and 0.1 to 75 mmol / liter of complexing agent. It is further preferred that the complexing agent is selected from the group consisting of aminocarboxylic acids, phosphonates, polyacrylic acids and polyacrylic acid copolymers and / or the textile fiber material is a cellulose-containing fiber material, in particular cotton.

The acidic aqueous medium can act on the textile fiber material at a temperature of 0-120 ⁰ C, wherein the temperature is advantageously chosen so that the activities of complexing agent and amylase are as high as possible and the amylase is not destroyed by the selected elevated temperature. Preferably a temperature in the range of 10 - 9O ⁰ C. More preferably, the exposure temperature is 20 - 40 ⁰ C. To maximize the activity and stability of complexing agents and amylases, a temperature profile or a temperature gradient can also be set with advantage optionally in combination with a pH gradient.

The process according to the invention can be carried out batchwise or continuously. In the batchwise process, the textile fiber material is impregnated in a liquor in the acidic aqueous medium, then squeezed off and the remaining acidic aqueous medium then acts on the textile fiber material at the selected reaction temperature. The process according to the invention can also be carried out continuously by drawing the textile fiber material for impregnation through a liquor with the acidic aqueous medium, then squeezing it in continuous process control and then acting on the textile fiber material.

The following examples serve to illustrate the invention.

definitions

Formal definition of iodine starch activity units (ISU)

The iodine-starch test does not give an absolute measure of the converted starch in moles per minute. However, the change in absorbance at 700 nm (A700) per minute is a relative indicator of the starch hydrolysis rate, all comparisons being made according to the same protocol. In the protocol used here, the amylase reaction is carried out in the presence of 0.1% strength with a suitable buffer at a predetermined pH and temperature in a volume of 1 ml. (The enzyme source is normally added as 0.1 ml of the total reaction volume of 1 ml.) At predetermined times becomes 100 μl supernatant of the reaction mixture withdrawn, mixed with 900 .mu.l of deionized water and 50 .mu.l of iodine reagent and the A700 determined against deionized water as a blank.

The activity is reducing the A700 over time during the consumption of the starch. An iodine-starch unit (ISU) of activity is defined as a reduction of 0.001 absorbance units at 700 nm (A700) per minute at a given pH and temperature during the amylase reaction being measured.

TEGEW A method for determining the degree of desizing

Violet scale for assessing the degree of desizing of starchy tissues (Issue

October 1996, Verband der Textilhilfsmittel-, Lederhilfsmittel-, Gerbstoff- und

Washing raw materials industry e. V.) Preparation of the iodine solution

Dissolve 10 g of potassium iodide in 100 ml of water, add 0.65 g of iodine and allow to complete

Shake solution. Make up to 800 ml with water, then make up to 1 liter with ethanol.

Application of the iodine solution

Place tissue sample in the iodine solution for 1 minute, rinse briefly with cold water, dab with filter paper and compare immediately with the violet scale.

BERGER-WG

The Berger whiteness is a standard value for whiteness (Claudio Puebla, Whiteness Assessment: A Primer, Axiphos, page 26). Berger's whiteness was measured with the Minolta Spectrophotometer CM-3600d.

example 1

A liquor containing 25 g / l OPTIAMYLASE (thermocacidophilic α-amylase from Alicyclobacillus acidocaldarius strain ATCC 27009, according to Schwermann et al., Eur. J. Biochem., 1994, 981-991, concentration of enzyme activity 773,000 ISU / ml at 70 ⁰ C pH = 3), 3 g / l PRODUCT A (mixture of concentrated sulfuric acid, 1-hydroxyethane- (1,1-diphosphonic acid) and diethylenetriamine penta (methylenephosphonic acid)) and 3 g / l PRODUCT B (mixture of a Ci ₂ polyglycol ethers with 12 ethylene oxide and 2 propylene oxide units, a C ₁₀ - polyglycol ether with 6 ethylene oxide units and a lsononansäure 2-ethylhexylamid) and a cotton fabric (100% cotton) is soaked in this liquor. The Fleet intake is 80%. After squeezing the liquid in a pad, the cotton fabric is treated at 70 ^° C. for 4 hours.

To improve the degree of desizing a pad-steam bleaching is performed. The cotton fabric is treated for 5 minutes at 100 ⁰ C and 100% steam. The degree of purification is determined by the TEGPΛ'A method.

Example 2

A liquor containing 25 g / l OPTIAMYLASE (thermoacidophilic α-amylase from Alicyclobacillus acidocaldaήus strain ATCC 27009, according to Schwermann et al., Eur. J. Biochem., 1994, 981-991, concentration of enzyme activity 773,000 ISU / ml at 70 ° C pH = 3). 5 g / l of product A (mixture of concentrated sulfuric acid, 1-hydroxyethane- (1, 1-diphosphonic acid) and diethylenetriamine-penta (methylenephosphonic acid)) and 2 g / l of product B (mixture of a C ₁₂ -polyglycol ether with 12 ethylene oxide and 2 propylene oxide units, C ₁₀ - polyglycol ether with 6 ethylene oxide units and a isononanoic acid 2-ethylhexylamide) set and a cotton fabric (100% cotton) is soaked in this liquor. The fleet intake is 80%. After squeezing the liquid in a padder, the cotton fabric is treated at 70 ° C for 4 hours. To improve the degree of desizing a pad-steam bleaching is performed. The cotton fabric is treated for 5 minutes at 100 ⁰ C and 100% steam. The degree of desizing is determined by the TEGEW A method.

Example 3

A liquor containing 5 g / l LAVISTA-ZYM R & D (dilution of a fungal α-amylase from Aspergillus sp. In an aqueous saline solution, concentration of enzyme activity 3.278.000 ISU / ml at 70 ° C. pH = 3.5) , 5 g / l of product A (mixture of concentrated sulfuric acid, 1-hydroxyethane- (1,1-diphosphonic acid) and diethylenetriamine penta (methylenephosphonic acid)) and 2 g / l of product B (mixture of a C ₁₂ polyglycol ether with 12 ethylene oxide - and 2 propylene oxide units, a C ₁₀ polyglycol ether with 6 ethylene oxide units and a lsononansäure-2-ethylhexylamide) and a cotton fabric (100% cotton) is soaked in this liquor. The fleet intake is 80%. After squeezing the liquid in a pad, the cotton fabric is treated at 70 ^° C. for 4 hours.

To improve the degree of desizing a pad-steam bleaching is performed. The cotton fabric is treated for 5 minutes at 100 ° C and 100% steam. The degree of desizing is determined by the TEGEW A method. Comparative example

For the desizing, a liquor containing 5 g / l LAVISTA-ZYM GEP (commercial product of Dr. Th. Böhme KG Chem. Fabrik GmbH & Co .. commercially available non-acid-stable α-amylase diluted in aqueous common salt solution, concentration of enzyme activity 3.865.000 U / ml (at 70 ⁰ C pH = 7) and 3 g / l Product B mixture of a C ₁₂ -Polyglykolether with 12 ethylene oxide and 2 propylene oxide units, C ₁₀ -Polyglykolether with 6 ethylene oxide units and a lsononansäure- 2-ethylhexylamide) and a cotton fabric (100% cotton) is soaked in this liquor. The fleet intake is 80%. After squeezing the liquid in a pad, the cotton fabric is treated at 70 ^° C. for 4 hours. After intensive washing, the cotton fabric (100% cotton) is demineralized with a liquor of 3 g / l of product A (mixture of concentrated sulfuric acid, 1-hydroxyethane- (1,1-diphosphonic acid) and diethylenetriamine penta (methylenephosphonic acid)) and 3 g / l PRODUCT B (mixture of a C ₁₂ - polyglycol ether with 12 ethylene oxide and 2 propylene oxide units, a C ₁₀ polyglycol ether with 6 ethylene oxide units and a lsononansäure 2-ethylhexylamid) soaked, squeezed and 1 hour at 70 ° C treated. To improve the degree of desizing, a pad-steam treatment is carried out. The cotton fabric is treated for 5 minutes at 100 ⁰ C and 100% steam. The degree of desizing is determined by the TEGEW A method.

The results are summarized in the table below. It is the Entschlichtungsgrade and the Berger whiteness (Berger-WG) after treatment with the standard amylase LAVIST A ^® -ZYM GEP (comparative examples) and after treatment with acid-resistant amylases (Examples 1 to 3) listed.

The results show that after the pad-steam bleaching with the single-stage process according to the invention similar desizing degrees as with the two-stage process of the prior art (Comparative Examples) can be achieved and, moreover, the degree of whiteness of the product could be increased. Furthermore, in Examples 1 to 3, compared to the comparative experiments, the total hardness of the product was significantly reduced. Material 100% CO 100% CO

Päd Roll (Soaking and Squeezing): Fleet Recording 80% Ped Steam: Fleet Recording 80%

Retention temperature 7O ⁰ C Retention temperature 100 ⁰ C

Residence time 4 h. Residence time 5 min

Claims

claims

1. Use of an acidic aqueous medium for the combined demineralization and desizing of textile fiber materials, characterized in that the acidic aqueous

Medium comprises an acid-stable amylase and a complexing agent.

2. Use according to claim 1, characterized in that the acidic aqueous medium has a pH of 1-5, preferably from 1, 5-4.8.

3. Use according to claim 1 or claim 2, characterized in that the amylase is a bacterial amylase, in particular a bacterial α-amylase from Bacillus licheniformis, Bacillus subtilis, Bacillus stearothermophilus, Sulfolobus acidocaldarius, Alicyclobacillus acidocaldarius, Thermoplasma acidophilum, Picrophilus torridus or Picrophilus oshimae or a fungal amylase, in particular a fungal α-amylase from Aspergillus niger, Aspergillus oryzae, Aspergillus kawachi or Aspergillus sp. or a mixture of several of these amylases.

4. Use according to any one of claims 1 to 3, characterized in that the acidic aqueous medium comprises 600,000 to 4,000,000 ISU / ml acid-stable amylase and 0.1 to 75 mmol / l complexing agent.

5. Use according to any one of claims 1 to 4, characterized in that the complexing agent from the group aminocarboxylic acids, phosphonates, polyacrylic acids and polyacrylic acid copolymers is selected.

6. Use according to any one of claims 1 to 5, characterized in that the acidic aqueous medium additionally an alcohol polyglycol ether of the formula

(OCH ₂ CH ₂ ) _P - (OCH ₂ CHCH ₃ VOH wherein m = 12-18 and p and q are independently 0-10.

7. Use according to any one of claims 1 to 6, characterized in that the acidic aqueous medium additionally contains one or more buffers.

8. Use according to one of claims 1 to 7, characterized in that the textile fiber material is a cellulose-containing fiber material, in particular cotton.

9. A process for the combined demineralization and desizing of textile fiber materials, which comprises allowing an acidic aqueous medium to act on the textile fiber material, characterized in that the acidic aqueous medium comprises an acid-stable amylase and a complexing agent.

10. The method according to claim 9, characterized in that the acidic aqueous medium has a pH of 1-5, preferably from 1, 5-4.8

11. The method according to claim 9 or claim 10, characterized in that the amylase is a bacterial amylase, in particular a bacterial α-amylase from Bacillus licheniformis, Bacillus subtilis, Bacillus stearothermophilus, Sulfolobus acidocaldarius, Alicyclobacillus acidocaldarius, Thermoplasma acidophilum, Picrophilus torridus or Picrophilus oshimae or a fungal amylase, in particular a fungal α-amylase from Aspergillus niger, Aspergillus oryzae, Aspergillus kawachi or Aspergillus sp. or a mixture of several of these amylases.

12. The method according to any one of claims 9 to 11, characterized in that the acidic aqueous medium additionally an alcohol polyglycol ether of the formula nC _m H _2m + i-

(OCH ₂ CH ₂ ) _p - (OCH ₂ CHCH ₃ ) _q -OH, wherein m = 12-18 and p and q are independently 0-10.

13. The method according to any one of claims 9 to 12, characterized in that the acidic aqueous medium at a temperature of 0 - 120 ⁰ C, preferably 10 - 90 ⁰ C, particularly preferably 20 - 40 ⁰ C act on the textile fiber material.