EP3795666B1 - Flat structure and use thereof when washing a textile material - Google Patents

Description

The present invention relates to a fabric and a method for washing a textile material as well as the use of the fabric in washing a textile material.

BACKGROUND OF THE INVENTION

The use of cloths (or similar sheet-like products) in the washing of textile materials, such as garments, is well known in the art. Such cloths are used to achieve various positive effects during the washing process.

For example, cloths with detergent substances applied to their surface are known from the prior art. Such cloths can be used as a replacement for powder or liquid ash agents or to support them.

In addition, washcloths are known to have optical brighteners applied to them. These optical brighteners are suitable for being adsorbed onto textiles and thus give the textiles a brilliant white or bright color.

Cloths are also known from the state of the art that are intended to prevent white laundry from turning grey. For example, cloths are used for this purpose whose surface is cationized, for example with a cationic compound. Due to the aforementioned surface modification, such cloths are able to catch dyes and dirt that are released during the washing process, so that they cannot be deposited on the laundry again.

Conversely, there is also the problem that black or dark items of laundry slowly become lighter after repeated washing. State-of-the-art detergents are known that are intended to counteract this lightening, for example by refreshing the dark color. However, the effect achieved with the state of the art is often inadequate and the lightening of the laundry cannot be stopped permanently or to a sufficient extent.

Other problems with known methods for washing laundry items arise from the mechanical stress during the washing process. In particular, if the laundry item to be washed contains cotton fibers, the mechanical stress during the washing process leads to fiber fibrils (fine fibers) which can then agglomerate, resulting in what is known as "pilling" (i.e. the formation of balls or lint in fabrics). These protruding fibers and balls impair the external appearance of the laundry item. Furthermore, these balls and protruding fibers cause the color of the textile to lose its luminosity due to the refraction of light and the textiles to appear washed out.

GB 2 524 319 A discloses a laundry article comprising: (i) a water-insoluble substrate; and (ii) a dried water-soluble coating on the substrate. The dried water-soluble coating comprises: (a) about 60 to about 95 wt.% of at least one surfactant; (b) about 0.5 to about 5 wt.% of at least one enzyme; (c) about 1 to about 35 wt.% of at least one binder; and (d) about 0 to about 15 wt.% residual water; the weight percentages are weight percentages of the total dried water-soluble coating.

DE 10 2015 119 949 A1 discloses a color-releasing product, in particular for dyeing or refreshing colorations in textile materials, preferably in a washing machine, comprising a flat carrier material, as well as a coating composition for a flat carrier material, a method for dyeing or refreshing colorations in textile materials as well as the use of the product.

DE 10 2014 008 586 A1 discloses a process for producing a detergent, characterized by the following steps: (a) incorporating oxygen donors and their activators into a wax matrix surrounded by an ionic polymer layer to obtain a capsule system, (b) incorporating the capsule system into a liquid detergent.

GB 2 258 655 A discloses aqueous, stable preparations containing both cellulase and protease and their use for the post-treatment of mixed fabrics.

It is therefore, based on the prior art, the object underlying the present invention to provide a cloth for a washing process which overcomes the disadvantages of the prior art, is particularly suitable for efficiently preventing a (preferably dark) item of laundry from lightening even after a large number of washing processes and at the same time preventing the occurrence of pilling during the individual washing processes.

DESCRIPTION OF THE INVENTION

This object is achieved according to the subject matter of the independent claims. Further embodiments emerge from the subclaims and the following description.

This object is achieved by a sheet-like structure comprising: a sheet-like carrier material; and at least one coating on at least one side of the sheet-like carrier material; wherein the coating comprises at least one cellulase and at least one dye; and the dye is black.

Surprisingly, the fabric according to the invention, when added to the washing solution/clothing during the washing of a dark item of clothing in a washing machine, enables the fabric to be washed even after a large number of washing processes to maintain the dark color of a washed item of laundry and at the same time prevent pilling.

It can be provided that the flat carrier material is a nonwoven fabric, a woven fabric, a scrim, a braid, a knitted fabric, a knit or a mixture thereof, preferably a nonwoven fabric or a woven fabric. Most preferably, the carrier material is a nonwoven fabric. It can preferably be provided that the flat carrier material is white or has a light color. In this context, it can preferably be provided that the flat carrier material is made of fibers that are not directly colored by the one or more dyes contained in the coating.

It can be provided that the sheet-like carrier material predominantly comprises synthetic fibers. In this context, "predominantly" means that the sheet-like carrier material comprises the synthetic fibers in an amount of at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, more preferably at least 80% by weight, more preferably at least 90% by weight, particularly preferably at least 95% by weight, most preferably consists of the synthetic fibers.

It can preferably be provided that the synthetic fibers comprise or consist of polyethersulfone fibers, polyolefin fibers, polyamide fibers, polyester fibers, fibers of degradable polymers, viscose fibers, polylactic acid fibers or mixtures thereof, preferably consist of polyethersulfone fibers.

In principle, the fiber diameter can be in a range from about 1 µm to about 0.5 mm. The fibers can be produced by any known method, for example a wet spinning process.

In one embodiment, it can be provided that the sheet-like carrier material has a basis weight of 10 to 500 g/m ² , preferably 30 to 100 g/m ² , preferably 40 to 80 g/m ² , preferably 50 to 70 g/m ² , particularly preferably 55 to 65 g/m ² .

It can be provided that the coating is applied to both sides of the flat carrier material or only to one side of the carrier material (in each case completely or partially). It can be provided that the coating is present in the flat structure in an amount of 10 g/m ² to 200 g/m ² , preferably 20 g/m ² to 100 g/m ² , particularly preferably 30 g/m ² to 50 g/m ² , based on the area of the carrier material.

In one embodiment, it can be provided that the coating further comprises at least one binder. In this case, it can be provided that the binder is selected from the group consisting of natural resins, synthetic resins and mixtures thereof.

Suitable natural resins in this context include gum arabic, guar gum, gelatin, dextrins, agar agar, alginic acid, alginates, carrageenan, egg white, gellan, locust bean gum, pectin, modified cellulose, starch, modified starch, xanthan gum or mixtures of two or more thereof.

Suitable synthetic resins in this context include polyesters, polyvinyl acetates, polyacrylates, polyglycols, polyvinyl alcohols, polyvinylpyrrolidones or mixtures of two or more thereof.

It can be provided that the binder is present in an amount of 1 wt.% to 50 wt.%, preferably 2 wt.% to 10 wt.%, based on the total weight of the coating.

It can be provided that the binder is suitable for releasing the dye and the enzyme into an aqueous solution from a temperature of 20 °C, preferably higher. It can also be provided that the binder is suitable for releasing the dye and the enzyme into an aqueous solution in a pH range of 3.5 to 10, preferably 6 to 10, particularly preferably 6 to 8.

In a preferred expression it is provided that the binder is starch and/or modified starch.

In one embodiment, it can be provided that the cellulase has a pH optimum in a range from 6 to 10, preferably 6 to 8. The cellulase to be used in the agents according to the invention can be an enzyme that can be obtained from bacteria or fungi and which has a pH optimum preferably in the almost neutral to alkaline range from 6 to 10, in particular from 6 to 8 (1% by weight solution in distilled water). Mixtures of two or more cellulases, and in particular cellulases from different organisms, can also be used in the agents according to the invention. For example, a cellulase can be provided that has a molecular weight of about 20 kDa and has at least 80% of its maximum activity at 50 °C in the pH range from 4 to 9, with almost 50% of the maximum activity still being retained at pH 10.

Cellulase is preferably contained in the coating in such amounts that it has a cellulolytic activity of 3 CMC-U to 40 CMC-U, in particular of 5 CMC-U to 25 CMC-U and particularly preferably of 6 CMC-U to 20 CMC-U, each based on 100 g of the coating. The determination of the cellulolytic activity (CMCase activity) is based on the M. Lever in Anal. Biochem. 47 (1972), 273-279 and Anal. Biochem. 81 (1977), 21-27 described procedure. 1 CMC-U corresponds to the amount of enzyme that produces 1 µmol glucose per minute under these conditions.

A suitable cellulase according to the invention is the commercially available Rucolase EPE 3120.

Preferably, the cellulase is present in the coating in an amount of from 0.1% to 1% by weight based on the total weight of the coating.

In principle, a large number of dyes can be used in the coating according to the invention. Azo dyes are particularly preferred. Azo dyes have one or more azo bridges as a chromophore. The dye is black. Examples of black dyes are the dyes Celasol Direkt Black OB 150% and Celasol Direkt Black VSF 600%. The two aforementioned black dyes are azo-direct dyes. However, other black azo dyes can also be used with preference in the coloring product according to the invention. Black azo dyes are used in particular to prevent dark-colored textiles, especially black textiles, from turning grey, or to freshen up their colors.

Preferably, the at least one dye is present in the coating in an amount ranging from about 5% to about 30%, preferably 5% to about 20%, more preferably 5% to about 15% by weight, based on the total weight of the coating.

It can be provided that the coating comprises at least one further additive selected from the group consisting of an odor absorber; preferably activated carbon or zinc ricinoleate; a fragrance; a color fixative; an optical brightener, preferably a cationic resin; a further enzyme, preferably an amylase, a protease, a lipase, a laccase, a pectinase or a mixture of two or more thereof; a complexing agent; a biocidal active ingredient; a natural substance extract; a washing-active substance, preferably a surfactant; a substance that supports a washing process, preferably carboxymethylcellulose; a substance that prevents re-soiling of textiles, a base, preferably Na ₂ CO ₃ ; a leveling agent, such as the commercially available Sarabid DLC; and mixtures of two or more thereof.

Furthermore, the object underlying the invention is achieved by a method for washing a textile material, comprising: providing the textile material together with a fabric according to the invention in water or (preferably) an aqueous solution; washing the textile material together with the fabric in the water or the aqueous solution at a temperature of at least 20 °C for at least 10 minutes.

Preferably, the method according to the invention is carried out in a washing machine, preferably at a temperature in a range of about 20 °C to about 95 °C, even more preferably at a temperature in a range of about 30 °C to about 65 °C, over a period of at least 10 minutes, preferably over a period of about 15 minutes to about 300 minutes, even more preferably over a period of about 30 minutes to about 90 minutes. Preferably, the A detergent, in particular a color detergent, is additionally added to the aqueous solution. The pH value of the aqueous solution is particularly preferably in a range from about 9 to about 13.

Preferably, the textile material is a piece of clothing, such as a shirt, T-shirt, trousers, jacket, sweater, stocking, socks, etc. It is also preferably provided that the textile material is made of cotton, natural fibres, polyester, polyamide or mixtures thereof.

Preferred embodiments which are described in connection with the sheet material according to the invention are also preferred embodiments with regard to the method according to the invention.

Finally, the object is achieved by the use of the fabric according to the invention when washing a textile material, in particular for dyeing the textile material, for refreshing a coloration of the textile material or for maintaining a coloration of the textile material as far as possible.

Preferred embodiments described in connection with the sheet material according to the invention are also preferred embodiments with regard to the use according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be described in detail below with reference to specific embodiments. This description serves primarily to illustrate the invention. The person skilled in the art is aware that not all of the features mentioned in the examples are necessarily necessary for the realization of the invention. The person skilled in the art is aware that, if necessary, individual features mentioned in the embodiments together with features listed in the general description of the invention can also contribute to the realization of the invention.

1. Production of a fabric according to the invention

A needle-punched nonwoven (60 g/m ² ) made of polyethersulfone (flat carrier material) was first printed with a pigment paste of the composition mentioned below using a rotary printing process to cover 1 - 100% of the nonwoven surface (consumption for 1% of the surface 0.6 g/m ² ), followed by drying and fixing.

Pigment paste composition (based on 1 kg paste): Bezaprint Black DW 27 g/kg Olimprint Navy RSV 13 g/kg print thickening for pigment 0.960 kg

Subsequently, a coating according to the invention was applied by surface application of a color-released coating composition of the following composition to the previously printed sheet-like carrier material using a roller doctor system.

Composition per 1 kg coating composition: Lameprint CE 0.05 kg Na ₂ CO ₃ 0.02 kg Celasol Direkt Black OB 150% (=dye) 0.035 kg Celasol Direkt Black VSF 600% (=dye) 0.035 kg Sarabid DLC 0.01 kg Rucolase EPE 3120 (=cellulase) 0.0032 kg demineralized water 0.8468 kg

A coating paste quantity of 300 g/m ² (+/-10 wt. %) was used, based on the area of the flat carrier material to be coated. After the coating composition was doctored onto the flat carrier material, the coating was dried until a solids content of the coating on the flat carrier material of 40 g/m ² (+/-10 wt. %) was obtained.

2. Comparative examples

As comparative examples, two further fabrics were produced in accordance with the instructions for producing the fabric according to the invention, whereby, in contrast to the exemplary embodiment according to the invention, in the first case only the dye, but not the cellulase, was contained in the coating, and in the second case only the cellulase, but not the dye, was contained in the coating.

3. Test results

• lediglich unter Verwendung des Colorwaschmittels (Probe 1),
• unter Verwendung des Colorwaschmittels und gleichzeitiger Verwendung der Flächengebilde gemäß den Vergleichsbeispielen (Probe 2, nur Farbstoff) und (Probe 3, nur Enzym) und
• unter Verwendung des Colorwaschmittels und gleichzeitiger Verwendung des erfindungsgemäßen Flächengebilde (Probe 4, Farbstoff + Enzym) durchgeführt.

Black items of laundry (new starting textile) were washed in a washing machine twenty times at 40°C together with a color detergent. The washing was

• using only the color detergent (sample 1),
• using the color detergent and simultaneously using the fabrics according to the comparative examples (sample 2, dye only) and (sample 3, enzyme only) and
• using the color detergent and simultaneous use of the fabric according to the invention (sample 4, dye + enzyme).

The brightness values of the washed laundry items as well as the pilling properties (product appearance) were determined and compared with the values obtained for the starting material (sample 5).

3.1 Brightness values

The brightness values L*(D65) were measured. The lower the L*(D65), the sample 1* 2* 3* 4** 5*** L*(D65) 32.8 28.0 32.2 25.8 25.6 the textile appears more colour-intensive (black). The following values were determined.
* Comparison examples
** Embodiment according to the invention
*** Original textile material

3.2 Pilling properties Evaluation of the product appearance (smoothness of the textile surface):

sample 1* 2* 3* 4** 5*** evaluation of product image 2 2-3 5 5 5

grading scale for evaluating the product image 5 smooth textile surface, no pilling 4 slight pilling 3 moderate pilling 2 noticeable pilling 1 dense, strong pilling

Surprisingly, for the laundry with the combination of black dye and enzyme (sample 4), a significant color deepening of the black laundry was observed, which corresponds to the color depth of the original fabric (sample 5) - with a simultaneously smooth fabric appearance without pilling - which goes beyond a color deepening that would have been expected for the individual coating components.

The features disclosed in the foregoing description and the appended claims may, separately or in combination, be subject to realization of the aspects of the disclosure made in the independent claims in different forms thereof.

Claims (13)

1. Sheet material, comprising:

   - a sheet-like carrier material; and

   - at least one coating on at least one side of the sheet-like carrier material;

   wherein the coating comprises at least one cellulase and at least one dye; and

   the dye is black.
2. Sheet material according to claim 1, wherein the sheet-like carrier material is a nonwoven fabric, a woven fabric, a laid web, a mesh, a knitting, a knitted fabric or a mixture thereof.
3. Sheet material according to claim 1 or 2, wherein the sheet-like carrier material comprises predominantly synthetic fibers.
4. Sheet material according to any one of the preceding claims, wherein the sheet-like carrier material has a basis weight of 10 to 500 g/m².
5. Sheet material according to any one of the preceding claims, wherein the coating further comprises at least one binder.
6. Sheet material according to claim 5, wherein the binder is selected from the group consisting of natural resins, synthetic resins and mixtures thereof.
7. Sheet material according to any one of claims 5 or 6, wherein the binder is starch and/or modified starch.
8. Sheet material according to any one of the preceding claims, wherein the cellulase has a pH optimum in a range of 6 to 10.
9. Sheet material according to any one of the preceding claims, wherein the dye is an azo dye.
10. Sheet material according to any one of the preceding claims, wherein the coating comprises at least one further additive selected from the group consisting of an odour absorber, a fragrance, a color fixative, an optical brightener, a further enzyme, a complexing agent, a biocidal active substance, a natural extract, a washing active substance, a substance supporting a washing process, a substance preventing re-soiling of textiles, a base, a levelling agent and mixtures of two or more thereof.
11. Method for washing a textile material, comprising

    - providing the textile material together with a sheet material according to any one of claims 1 to 10 in water or an aqueous solution;

    - washing the textile material together with the sheet material in the water or the aqueous solution at a temperature of at least 20°C for at least 10 minutes.
12. Method according to claim 11, wherein the aqueous solution further comprises at least one washing agent.
13. Use of the sheet material according to any one of claims 1 to 10 in washing a textile material.