AT505369A1 - METHOD FOR THE TREATMENT OF CELLULOSE-RELATED TEXTILE - Google Patents

Description

The invention relates to a process for the enzymatic treatment of cellulose-containing textile by means of a solution comprising at least one kind of cellulase.

Enzymatic processes have found wide application in the treatment of textile substrates. In recent years cellulose-splitting enzymes (cellulases) have become very important in the textile-chemical treatment of cellulose fiber-containing materials. The most commonly used "total crude" cellulases are a mixture of microbiologically produced endo-, exocellullases and cellobiohydrolases. The object of the cellulases is the hydrolytic degradation of the cellulose by selective cleavage of the β-1,4-glycosidic bond, whereby soluble fragments are removed from the polymers and taken up by the treatment solution, where a further hydrolysis to glucose takes place. It is mostly aimed at changing the feel of the materials, removing lint and improving the unwanted polishing of the materials. A particular area of application is also found in the wash of indigo-dyed denim textiles, where the enzymatic treatment is used as a replacement or supplement for the bleaching treatment. Here the enzymes enable the so-called wash-down, which leads to the used look of the jeans in washing processes of the finished textiles.

Furthermore, it is known from the prior art to treat cellulose-containing fibers with alkaline cellulase solution, since the degradation rate of cellulose in the alkaline medium is higher than in the neutral pH range. Finally, it is known to provide cotton fibers with a swelling agent prior to cellulase treatment in order to reduce enzymatic degradation in the region which houses the quellum.

The textiles are exposed to the cellulase treatment in all processes in large washing machines, which weaken the fabric by hydrolytic attack and thereby support in combination with the washing mechanism the abrasion of a possible dye, which leads to the development of a wash-down. Cellulase treatments are always associated with losses in the mechanical resistance of the fabric, which manifests itself in reduced strength and reduced abrasion resistance of the treated products compared to untreated products. This reduction in utility value is an undesirable consequence of cellulase treatment. "* * · · · · * ···· * · ♦ · ····················································································. · T # 2

Object of the present invention is therefore to provide a method of the type mentioned, in which the textile loses imperceptible to mechanical resistance.

This object is achieved by a method according to claim 1. Such a method of the type mentioned is characterized in that prior to treatment with the cellulase-containing solution, an alkaline substance, preferably an alkaline solution, is applied only in regions on the textile.

According to DIN 60 000, a textile likewise comprises textile fibers, semi-finished and finished textile products such as yarn or textile fabric and textile finished goods such as textile clothing etc. It is essential to the invention that the textile comprises cellulose (eg blended fabric) -but the textile does not have to consist of it.

In such a method it can be provided that the textile (for example the textile fiber) is pretreated on the surface with an alkaline substance such that the alkaline substance penetrates only slightly into the textile or the textile fiber. For this purpose it can be provided that before the treatment with the cellulase-containing solution, the alkaline substance, preferably alkaline solution, is applied to the surface of the textile fiber or of the textile such that it remains substantially on the surface of the textile. Under "remain essentially on the surface of the textile fiber " is meant that the alkaline substance can not penetrate to the core of the textile fiber or the textile, but under 20 to 30% of the thickness of the textile fiber, preferably penetrates below 10% of the thickness of the textile fiber in the textile fiber.

This is achieved in particular by the fact that the alkaline substance is applied by spraying and / or patting and / or doctoring and / or printing.

It is preferably provided that the textile fiber or the flat textile obtained from a textile fiber such as textile fabric is provided with patterns which on the one hand may have different color ("stone-wash effect"), on the other hand a more pleasant or modified handle. In the event that the textile fibers are present in a flat textile, preferably textile fabric, it is possible to apply individual patterns to the textile which can be predetermined, in particular by printing a predefinable printing pattern. It can be provided that the alkaline substance is applied at least partially on one side of the flat textile. Especially in the case of • ····························································· · Functional textiles is a different treatment of the two sides of the textile fabric of interest, thereby advantages in the functional properties (water transport, absorbency, smoothness etc.).

The invention is based on the fact that in the areas where an alkaline substance has been applied, an increased rate of degradation can be achieved, since the cellulase has a higher reaction rate at these points. It is favorable if the alkaline substance comprises an aqueous solution of at least one metal hydroxide, preferably an alkaline earth metal hydroxide and / or alkali metal hydroxide, wherein it is preferably provided that the metal hydroxide is NaOH.

The rate of reaction of the fiber-enzyme reaction depends on the fiber type presented (cotton, viscose fibers, lyocell fibers, etc.) as well as the concentration and activity of the enzymes used. Depending on the processing stage in the textile finishing process, the fiber changes in its reactivity. For example, it is known in the prior art that cotton textiles after treatment in concentrated caustic soda show an increased degradation rate by cellulases, which is mainly due to reduced crystallinity and increased accessibility of the fiber.

In order to select suitable conditions for the corresponding textile fiber type, so that the above-mentioned requirements are met, it may be favorable if the alkaline solution has a thickening agent. In order to promote the course of the reaction, it is further favorable if the alkaline substance has a humectant, wherein it is particularly preferred that the humectant comprises glycerol.

The treatment of cellulosic substrates in solutions of various alkaline substances has been extensively studied because of the possibility of changing the reactivity of the cellulose. Alkaline treatment solutions known in the art may contain alkali ions (Li, Na, K ions), as well as, for example, alkaline earth hydroxides and quaternary ammonium hydroxides. The treatment in solvent systems (alcoholic solutions of swelling agents) has also been described in the prior art.

The present invention is therefore based on the idea to make the activation of the fiber only localized and thus to limit the rate of hydrolytic degradation of the cellulase on certain areas of the textile structure. • t · t ················································································································································································································

This is achieved by the action of the activating alkali treatment is limited only to areas of the material. This can be done for example on the surface of the textile structure by the amount of alkali is applied so that only the outermost structure for the cellulase attack is activated. Unexpectedly, this can lead to a strong surface activation, so that there is a hydrolytic effect of the enzymes, which is mainly limited to the surface.

The application of the activating alkali solution can be carried out by spraying, paddling, knife coating, and minimal application techniques on one or both sides of the product by the usual methods, in a particularly advantageous embodiment, printing techniques (stencil printing, foam printing) are mentioned. As a result, both a one-sided surface activation of the cellulose can be carried out as well as a patterning effect can be realized.

Alkali solutions may be alkali hydroxides, alkaline earth hydroxides, quaternary ammonium bases as well as amines or other basic compounds known to those of ordinary skill in the art.

Advantageous concentrations of the application solutions are in the range from 0.5 to 10 mol / l of alkali solution, the concentration being determined by the desired activation effect, the textile substrate to be treated and an optional intermediate drying. In the intermediate drying, a concentration of the non-volatile alkali is carried out on the surface, so that higher concentrations are achieved here compared with the applied application solution. The optimum concentration range for a desired result will be easy to determine with knowledge of the invention, even for the average expert by series experiments.

In an advantageous embodiment, the applied solution beforehand admixed with humectants such as glycerin to prevent complete drying and hardening.

Textile structures can be, for example, woven fabrics, knitted fabrics, nonwovens, films, etc., with no restrictions with regard to the material form to be treated. Cellulosic substrates may preferably be made of cotton, bast fibers, viscose, modal, lyocell fibers or mixtures thereof with other fibers of cellulose or other e ················································································. · 9 · 9999 · 9 · 9 9 9 f # 9 9 ♦ · 99 19 9t 99 · 5

Fiber materials in particular synthetic materials. In a preferred form, dyed textiles of cotton or other cellulosic fibers, or their blends, are treated with synthetic fibers (such as Lycra, polyester fibers, polyamide), in a particularly preferred embodiment, indigo dyed denim webs of cellulosic fibers are treated.

Suitable cellulase treatment methods may be selected from the methods proposed in the prior art.

Local activation leads to accelerated hydrolysis of the cellulose in these areas. If the treatment is carried out on the surface, especially the surface is hydrolytically attacked by the cellulases and the strength and mechanical resistance of the material in the core of the textile structure is less affected. In a particularly preferred form of treatment, indigo-dyed denim fabric is activated, offering the advantage of faster detachment of the indigo dye from the fabric surface. As a result, the washing processes in the denim wash can be shortened in an advantageous manner, the activation takes place according to predetermined patterns, so special pattern effects and designs can be realized. Conveniently, it may further be provided that after the application of the alkaline solution and before the cellulase treatment a drying step takes place, preferably by heating the textile.

The preferred embodiment provides that the textile is at least partially dyed, preferably indigo-dyed, wherein it is particularly preferred that the textile comprises textile fibers which are woven into a fabric, preferably denim fabric, or the alkaline substance in ready-made textiles before a washing treatment.

Further details of the invention will be explained with reference to the following examples and the figure. It shows the figure a print pattern on a textile fabric in Draufeicht.

In the figure, woven textile fibers woven into a textile fabric in the form of a textile fabric 1 are shown schematically. On the textile fabric 1 is partially applied to the checkered areas 2 an alkaline substance. The white areas 3 are untreated. ····· ·····························································································. · «· · ·· ·· · 6

Application Example 1 - Denim

Desized denim fabric (indigo dyed cotton fabric) grade I (483 g / m2, warp 27 Fd / cm, weft 19 Fd / cm) grade II (466 g / m2, warp 18 Fd / cm, weft 18 Fd / cm) was used.

The activation was carried out by printing on a thickener viscous alkali solution by the screen printing method.

Prescription of printing paste: 73% w / w alkali-stable printing thickening (20 g / l Prisulon GT 1000 M, Bezema AG, Switzerland) 23% w / w NaOH 50%.

After one minute exposure time, the alkaline paste was washed with water, rinsed three times with cold water and neutralized at 40 ° C with 1% acetic acid.

The enzyme treatment was then carried out in a laboratory dyeing plant (Pretema Multicolor laboratory dyeing unit type MC 360, Caromatic, Switzerland). A "totally crude cellulose" Genencor, USA, was used at a concentration of 3.0 lU / mg tissue (30 mL / L treatment bath). The solution was adjusted to pH 4.8 by a 50 mM acetate buffer. The liquor ratio was 1 g of tissue: 25 ml of treatment bath.

Material I was treated for 1.5 hours, material II for 0.75 hours at a temperature of 55 ° C. The enzymatic hydrolysis was stopped by raising the temperature to 75 ° C. and raising the pH to 10 and treating for 10 minutes. The samples were rinsed and air dried.

The effectiveness of treatment of the activated areas quality I and quality II was compared with the non-activated surface by colorimetry.

Table 1 compares the results of the untreated and activated tissues. The increased brightness due to the increased degradation on the surface of the materials is clearly visible. The total color difference Δ E is also calculated and shown. The ΔΕ values above 6 clearly show the increased color loss on the alkaline pretreated areas. »· ············································ · · · · · · · · * Μ '·' · · 7

Table 1. Color coordinates of grades I and II after cellulase treatment with and without previous activation treatment (L * = brightness (0 = black, 100 = white) a * = red - green (-value = green, + value = red) b * = Yellow - Blue (-value = blue, + value = yellow) and AE symbolize the CIELab coordinates or the corresponding color difference The CIE-Lab system is one of the International Commission on Illumination (Commission Internationale d'Eclairage, CIE) 1976 fixed color space).

Material Treatment L * a * b * AE I Not activated 23.77 1.40 -8.70 Activated 29.21 0.32 -11.54 Difference 5.44 1.08 -2.84 6.23 II Not activated 27.76 1.34 -16.78 Activated 34.08 -0.19 -15.93 Difference 6.32 1.16 0.85 6.48

Application Example 2 - Treatment of regenerated cellulose fibers

Example 2 shows the increase in the rate of degradation by alkaline pretreatment using the example of regenerated fibers

Viscose fabric (CV) (Stapelfasergam 38 mm, 1.3 dtex) was used as a substrate. Plain weave chain 20 tex, weft, 24 tex, twist 19 rounds / inch, 143 g / m2, 37/29 fd / cm was used.

The treatment solution was prepared by diluting a 50% (w / w) sodium hydroxide solution with water (1.04, 2.20, 3.48 and 4.91 mol / L NaOH).

The fabric was pretensioned in different alkali solutions for 1 minute at a liquor ratio of 1: 3. The concentration of

Treatment solutions are given in Table 2.

After squeezing in a pad, the fabric was rinsed with distilled water and neutralized with 0.02 mol / L acetic acid. Comparative samples were treated without alkaline pretreatment. • · 8th

The enzyme treatment was then carried out in a laboratory dyeing plant (Pretema Multicolor laboratory dyeing unit type MC 360, Caromatic, Switzerland). A "total crude cellulose" Genencor, USA, was used at a concentration of 3.5 IU / mg tissue (30 mg protein per mL). The solution was adjusted to pH 4.8 by a 50 mM acetate buffer. The liquor ratio was 1 g of tissue: 25 ml of treatment bath.

The hydrolysis was carried out at 55 ° C (+/- 1 ° C). After 1 hour of treatment, the weight loss was evaluated by measuring the concentration of glucose formed in the solution. Comparative measurements were performed with non-pretreated materials.

Table 2 shows the altered degradation measured as the concentration of glucose formed per L treatment bath after one hour.

Table 2. Glucose concentration in solution on enzymatic hydrolysis of viscose with and without alkaline activation

Glucose concentration Tissue pattern [g / L] Untreated control 1.81 Activation with 1.04 mol / L NaOH, 60 sec 2.50 Activation with 2.20 mol / L NaOH, 60 sec 7.15 Activation at 3.48 mol / L NaOH, 60 sec 11.29

Fabrics made from other regenerated cellulose fibers can be treated in the same way. Table 3 shows the increase in degradation rate measured after 1 hour of hydrolysis time.

Table 3. Degradation measured as g / L glucose and activation

Concentration in g / L Glucose Treatment in control sample 3.48 mol / L NaOH% Activation Viscous 1.81 11.28 625 Modal 0.65 6.45 992 Lyocell 0.47 3.95 848 Lyocell cross-linked 0.33 5.26 1594 •·················································································································································································································

By an alkaline treatment, the degradation rate is increased by a factor of 6-15.

Innsbruck, June 4, 2007

Claims (16)

· · · · · · · · «« «« Patent Patent Patent Patent Patent Patent PatentΜ. 1. A process for the enzymatic treatment of cellulosehältigem textile by means of a solution having at least one type of cellulase, characterized in that prior to treatment with the cellulase-containing solution, an alkaline substance, preferably an alkaline solution, only partially applied to the textile. 2. The method according to claim 1, characterized in that before the treatment with the cellulase-containing solution, the alkaline substance, preferably alkaline solution, is applied to the surface of the textile, that it remains substantially on the surface of the textile. 3. The method according to 1 or claim 2, characterized in that the textile is in a flat form. 4. The method according to claim 3, characterized in that the alkaline substance is applied at least partially on one side of the sheet-like textile. 5. The method according to claim 5, characterized in that the alkaline substance is an aqueous solution of at least one metal hydroxide, preferably an alkaline earth metal hydroxide and / or alkali metal hydroxide. 6. The method according to claim 5, characterized in that the metal hydroxide from the group NaOH, KOH, LiOH or mixtures thereof is selected. 7. The method according to claim 6, characterized in that the metal hydroxide is NaOH. 8. The method according to any one of claims 1 to 7, characterized in that the alkaline substance by spraying and / or patting and / or doctoring and / or printing on the textile, is applied. 9. The method according to claim 8, characterized in that the alkaline solution has a thickening agent. 62145 38 / hn ····································································································································································································································· 9 Φ · * ·· ··· «·· · 2 10. The method according to any one of claims 1 to 9, characterized in that the alkaline substance has a humectant. 11. The method according to claim 10, characterized in that the humectant comprises glycerol. 12. The method according to any one of claims 1 to 11, characterized in that after the application of the alkaline solution and prior to the cellulase treatment, a drying step, preferably by heating the textile takes place. 13. The method according to any one of claims 1 to 12, characterized in that the textile is at least partially colored, preferably indigo-dyed. 14. The method according to claim 13, characterized in that the textile textile fibers, which are woven into a fabric, preferably denim fabric. 15. The method according to any one of claims 1 to 14, characterized in that the alkaline substance takes place on ready-made textiles before a washing treatment. 16. The method according to any one of claims 1 to 15, characterized in that prior to the cellulase treatment, the alkaline substance is washed out. Innsbruck, June 4, 2007