WO2009115217A1

WO2009115217A1 - Nonwoven fabric provided with antibacterial finishing and having conjugate fibers

Info

Publication number: WO2009115217A1
Application number: PCT/EP2009/001721
Authority: WO
Inventors: Robert Groten; Andreas Eisenhut; Ameur Abdelkader; Günter Schmitt; Judith Haller; Thomas Schindler
Original assignee: Carl Freudenberg Kg
Priority date: 2008-03-19
Filing date: 2009-03-11
Publication date: 2009-09-24

Abstract

The invention relates to a nonwoven fabric, comprising conjugate fibers having a fiber body, in which at least one doping agent is received for the antimicrobial finishing, wherein the conjugate fibers are configured as filaments, said fabric being characterized by a long-term effective reactivity of the doping agent acting in an antimicrobial manner and the ability to be washed multiple times in a cost-effective manner, characterized by conjugate fibers that are split into elementary fibers, and by a surface density of 1200 to 3250 m2 / kg.

Description

Antibacterial nonwoven fabric with bicomponent fibers

description

Technical area

The invention relates to a nonwoven fabric comprising bicomponent fibers with a fiber body, in which at least one dopant is added to the antimicrobial equipment, wherein the bicomponent fibers are configured as continuous fibers.

State of the art

From the prior art nonwovens are known which have an antimicrobial dopant. In this case, an antimicrobial substance acts antibacterial, antiviral, antifungal and / or against spores. Against this background, silver in particular has proven to be a suitable antimicrobial agent.

It is already known to equip toilet paper with silver. However, this equipment is not durable, as the silver is only superficially applied to the toilet paper. Frequently, silver is also determined by means of binders on textile materials. However, by washing processes, the applied silver is detached and can penetrate into water treatment plants. This is an extremely detrimental effect associated with high economic damage.

Presentation of the invention

The invention is therefore based on the object to provide a nonwoven, which is characterized by a long-term effective reactivity of the antimicrobial dopant and at the same time is multi-washable at low cost.

According to the invention, the above object is achieved with the features of claim 1.

Thereafter, the aforementioned nonwoven fabric is characterized by bicomponent fibers which are split into elementary fibers, and by a surface density of 1200 to 3250 m <2> / kg.

According to the invention, it has first been recognized that a nonwoven fabric which has continuous fibers has a good quality even after several washing processes. This is due to the fact that continuous fibers are entangled at a variety of locations and therefore difficult to dissolve out of the nonwoven composite. Furthermore, it has been recognized that the use of bicomponent fibers with a fibrous body in which at least one dopant is included for antimicrobial finishing allows the nonwoven to be consolidated. It is concretely conceivable to solidify the nonwoven fabric by a water jet needling process. The bicomponent fibers are split partially or completely into very fine elementary fibers. It is also conceivable to solidify the nonwoven fabric by a thermal treatment.

In concrete terms, it has been recognized that the incorporation of the antimicrobial dopant into the fiber body ensures a very long-term release of the dopant. The antimicrobial effect is limited to the nonwoven fabric by largely preventing microbial growth in the nonwoven itself. According to the invention, the antimicrobial active substance is currently not released to a considerable extent on surfaces which are treated with the nonwoven fabric. The dopant is incorporated directly into the fiber body, which creates an antimicrobial effect, especially on the surface of the continuous fibers. The release of the dopant takes place only in very small amounts, it remains largely bound in the nonwoven fabric or in the fiber body. The nonwoven fabric is therefore extremely washable while retaining a high reactivity.

The bicomponent fibers are split into endless elementary fibers. By this specific embodiment, a nonwoven fabric with very fine

Elementary fibers are created. The splitting can take place, for example, by means of a water-jet needling method, wherein the elementary fibers are additionally entwined with each other. As a result, the nonwoven fabric can be solidified. It is advantageous that the elementary fibers have a larger surface area than the unsplit

Bicomponent fibers offer the same basis weight of the nonwoven fabric. Through the surface of the dopant can interact externally.

The nonwoven fabric according to the invention has a surface area of 1200 to 3250 m 2 per kg of nonwoven fabric. This provides a very high contact area at which the growth of viruses or bacteria can be inhibited.

Consequently, the stated object is achieved. The elementary fibers can be designed particularly advantageously as microfilaments of a fineness of 0.05 to 1 dtex. Microfilaments of such fineness provide a particularly large contact surface for bacteria and spores.

The dopant could be homogeneously distributed only in one component of the fiber body. By this specific embodiment, for example, the shell of a core-sheath continuous fiber can be melted to connect with other continuous fibers, without the present in the core dopant is adversely affected. Against this background, it is conceivable that side-by-side bicomponent endless fibers are also used. It is also conceivable to use Iceland-in-the-Sea bicomponent filaments.

The dopant could be present in a concentration of at least 100 ppm in the nonwoven fabric. Surprisingly, it has been shown that even such a low concentration of the dopant can develop an antimicrobial action against viruses, spores or bacteria.

The dopant could be present in a concentration of at most 500 ppm in the nonwoven fabric. The choice of this concentration has been found to be advantageous to give a dyed nonwoven durable reactivity. Although the doping is shielded by the coloring, by the said concentration, it can still develop its effect in sufficient quantity.

The dopant could also be present in a concentration of less or at most 100 ppm in the nonwoven fabric. Surprisingly, it has been shown that even such a low concentration of the dopant can develop an antimicrobial action against viruses, spores or bacteria.

The bicomponent fiber could comprise a component of polyamide or polyethylene and a component of polyethylene terephthalate or polyester. By this specific embodiment, it is easily possible to split the bicomponent fiber by water jets in elementary fibers.

Against this background, the bicomponent fiber could comprise 30% polyamide or polyethylene. The proportion of polyethylene terephthalate or polyester is substantially 70%.

The dopant could be homogeneously distributed in the component of the fiber body comprising polyethylene terephthalate or polyester. Polyethylene terephthalate and polyesters have proven to be particularly suitable media for receiving the dopant. Due to the higher mass fraction of the component comprising polyethylene terephthalate or polyester, a more effective volume distribution of the dopant in the nonwoven fabric can be achieved.

The bicomponent fiber could be configured as PIE fiber. Through this specific embodiment, a relatively coarse bicomponent fiber can be split into very fine elementary fibers with cake-piece-like or circular segment-like cross sections. By way of example only, reference may be made at this point to DE 697 25 051 T2, which describes a method in which PIE fibers are produced and split.

The dopant could be designed as an element of a subgroup, in particular subgroup Ib of the Periodic Table of the Elements. Subgroup elements are characterized by antimicrobial activity. Against this background, it is conceivable that several subgroup elements exist together in the fiber body in order to selectively counteract different bacterial species. It has been shown in test series that there is a ranking of the substances used in terms of antimicrobial effectiveness. This can be represented as follows. Silver is the most effective substance, followed by mercury, copper, cadmium, chromium, lead, cobalt, gold, zinc, iron and finally manganese. The same applies to salts and complexes of the named elements or substances.

The dopant could be designed against this background as silver, gold or copper. These elements show a particularly reliable antimicrobial effect and are readily available commercially as fine particles.

The nonwoven fabric could have a basis weight of at least 20 g / m 2. This basis weight has proved to be particularly advantageous to

Make wipes or wipes for the cosmetics industry. Preferably, the nonwoven fabric could have a basis weight of 20 to 200 g / m 2. This basis weight is suitable for the production of bandages or layers for the wound cover.

The nonwoven fabric could be colored. Surprisingly, it has been found that an antimicrobially finished nonwoven fabric can be dyed and yet retains its antimicrobial effect.

The nonwoven web could have a water absorbency of at least 350 percent by weight of its own dry weight. Such a nonwoven fabric is characterized by a high absorbency.

The nonwoven fabric could have a water absorption capacity after a household wash according to DIN EN ISO 6330 of at least 400

Percent by weight of its own weight in the dry state. Such a nonwoven still shows after many washes still excellent absorbency for water and oils.

The nonwoven fabric described here can easily be in contact with human skin. Advantageously, the nonwoven fabric described herein has such a low concentration of a dopant that the human skin is not irritated. In particular eczema patients require a gentle nonwoven fabric, as described here. Nevertheless, the filaments also exhibit sufficient dopant concentration on the filament surface to stop or inhibit the growth or propagation of bacteria, viruses and spores.

The nonwoven fabric described herein may be used as a wipe or to make a wipe. This use surprisingly shows a combinatorial effect, which is reflected in a high reactivity of the dopant and a high resistance to washing of the wipe. A washable, permanently antimicrobially-doped wipe, for example, in milk-contaminated state no bacterial decomposition, so that almost no odor in the home can arise. Very particularly advantageous, however, is the use in commercial cleaning, since wipers are washed and dried here daily. If the wipes are equipped antimicrobial, it can be dispensed with a subsequent drying of the wipes.

Experiments have shown that with each wash an energy saving of more than 3 kWh / kg wipe can be realized.

There are now various possibilities for embodying and developing the teaching of the present invention in an advantageous manner. For this purpose, on the one hand to the subordinate claims, on the other hand, to refer to the following explanation of preferred embodiments of the inventive teaching with reference to the table and the drawings.

In connection with the explanation of the preferred embodiments with reference to the table and the drawing also generally preferred embodiments and developments of the teaching are explained.

Brief description of the drawing

In the drawing show

1 is a scanning electron micrograph of a

Nonwoven fabric comprising PIE bicomponent fibers with antimicrobial finish,

Fig. 2 is a scanning electron micrograph of PIE fibers whose polyethylene terephthalate component is doped with silver, showing the silver in bright whitish spots

3 is a scanning electron micrograph of a PIE 16th

Fiber and

Fig. 4 is a scanning electron micrograph of a split

PIE 16 fiber.

Embodiment of the invention

In the drawing, Fig. 1 shows a nonwoven fabric with bicomponent fibers, which are designed as continuous fibers. The bicomponent fibers are designed as PIE fibers and consist of 30% polyamide 6 and about 70% of polyethylene tereptalate. The polyethylene terephthalate is enriched with the dopant silver. In this case, the dopant silver is homogeneously distributed in the component of the fiber body having polyethylene terephthalate. The silver is present in a concentration of at least 200 ppm and at most 500 ppm.

FIG. 2 shows the bicomponent fibers of FIG. 1 having eight segments of polyethylene terephthalate. The segments have the dopant silver. The silver can be recognized in the form of bright spots in the scanning electron micrograph.

FIG. 3 shows an example of a scanning electron micrograph of a PIE 16 fiber and FIG. 4 shows a scanning electron micrograph of a split PIE 16 fiber.

The table shows the three embodiments 1 to 3 of the nonwoven fabric according to the invention. Embodiments 1 to 3 show different concentrations of the dopant in the polyethylene terephthalate component. The nonwovens (working examples 1 to 3) were produced on the basis of the method described in DE 697 25 051 T2 and analogously to the preparation of the comparative sample EVOLON 130 g / m 2 or EVO 130.

The polyethylene terephthalate component was prepared in each of Embodiments 1 to 3 in the following manner.

To prepare Embodiment 1, 970 g of polyethylene terephthalate were mixed with 30 g of a master batch component to obtain a 3% concentration of master batch as shown in the table. The masterbatch component contained more than 99% polyethylene terephthalate and less than 1% silver. Similarly, for embodiment 2, 960 g of polyethylene terephthalate were mixed with 40 g of the masterbatch component. For embodiment 3, 950 g of polyethylene terephthalate were mixed with 50 g of said master batch component. The dopant used was silver from Silanotex GmbH, 80687 Munich. In concrete terms, the master batch "Nano-SilverMaster-Batch" of the named company was used in the stated amounts.

The nonwoven fabrics of Working Examples 1 to 3 were evaluated for tear propagation resistance, tear resistance, extensibility, uniformity, permeability, thickness, basis weight and shrinkage. Where "N" stands for Newton, "MD" for machine direction (production direction) and "CD" for cross direction. MD and CD denote mutually orthogonal loading directions, namely in the direction of production and orthogonal thereto.

The size CV, namely the coefficient of variation of the basis weight of the nonwoven fabric, was determined by the following method and formulas:

From a nonwoven fabric with a width of 2 m, 40 specimens, 5 × 5 cm 2, are punched across the width with a punching iron (200 cm: 5 cm = 40 specimens). A sample of 5 cm x 5 cm has a surface weight of 0.0025 m <2>. Measured weight of the test piece times 400 gives basis weight in g / 1 m <2>.

The deviation from the mean value of all specimen weights is equal to the root of [(sum (xi - X) <2>) / n],

where xi: weight of each specimen X: average over all specimen weights n: number of specimens.

The coefficient of variation CV (%) is then obtained by: CV = (deviation from the mean of all specimen weights x 100): X

The comparative sample used was a nonwoven fabric of the Evolon type having a basis weight of 130 g / m 2. The comparative example is made from bicomponent fibers comprising 70% polyethylene terephthalate and 30% polyamide 6. The polyamide used in the embodiments 1 to 3 is also polyamide 6.

The table essentially states that the doping of embodiments 1 to 3 with silver has no negative effects on the mechanical properties of the exemplary embodiments in comparison with the comparative sample. The exemplary embodiments were manufactured analogously to the comparative sample except for the doping, which is commercially available under the product designation "EVOLON 130 g / m 2 or EVO 130".

The nonwoven fabrics of the embodiments 1 to 3 are made

Bicomponent fibers comprising 70% polyethylene terephthalate and 30% polyamide 6. The embodiments were made from PIE 16 bicomponent fibers that had a fineness of 2.4 dtex before the splitter. When fully spliced, the nonwoven fabrics have a surface area per mass of 1219 m 2 / kg nonwoven.

A nonwoven fabric according to a fourth embodiment 4 consists of bicomponent fibers which comprise 70% polyethylene terephthalate and 30% polyamide 6. The embodiment was made of PIE 32 bicomponent fibers that had a fineness of 1.6 dtex before splitting. When fully spliced, the nonwoven fabric has a surface area per mass of 2741 m 2 / kg of nonwoven fabric.

A surface area per mass of 3250 m 2 / kg nonwoven fabric can be achieved when using PIE 32 bicomponent fibers which are 70% polypropylene and 30% polyethylene and have a fineness of 1.6 dtex prior to complete splitting.

A nonwoven fabric according to one of the embodiments 1 to 4 shows in the new state, a water absorption of at least 350 weight percent of its own weight in the dry state.

After a one-time household cooking wash according to DIN EN ISO 6330 of the nonwoven, this shows a water absorption of 450 to 650 weight percent of its own weight in the dry state.

After a single household wash according to DIN EN ISO 6330 of the nonwoven, this shows an olive oil intake or machine oil absorption of the oil type SAE 5W40 of at least 400 percent by weight of its own weight in the dry state.

The nonwovens described herein are washable at least 400 times without forming holes in the nonwovens, wherein a washing process is designed as a household cooking wash according to DIN EN ISO 6330. A wet nonwoven fabric can be wrung manually after 400 washes according to DIN EN ISO 6330 without tearing. The nonwoven fabrics described here are therefore durable.

Furthermore, the nonwovens give off as little silver in a domestic cooking wash at 90 ° C. that only 5 g of silver per liter of wash eluate occur in the wash eluate according to DIN EN ISO 17294-2. The nonwovens described here therefore retain the silver very well and pollute the wastewater only to a very small extent.

The wash eluate is obtained by the following procedure: 0.2% of the surfactant "Tween 80" (Carl Roth GmbH & Co. KG, Karlsruhe, DE) are mixed with 0.9% NaCl in water to form a solution. In 200 ml of this solution, 4 g of the embodiments described here are given. The solution is then shaken together with the nonwoven fabric at 37 ° C. for 24 h. In this solution, a concentration of at most 5 [mu] g per l wash eluate sets.

Finally, it should be expressly understood that the embodiments described above are only for the purpose of discussion of the claimed teaching, but not limit these to these embodiments.

table

Claims

claims

1. A nonwoven fabric comprising bicomponent fibers with a fiber body, in which at least one dopant for antimicrobial equipment is added, wherein the bicomponent fibers are configured as continuous fibers, characterized by bicomponent fibers which are split into elementary fibers, and by a surface density of 1200 to 3250 m <2 > / kg.

2. Nonwoven fabric according to claim 1, characterized in that the elementary fibers have a fineness of 0.05 to 1 dtex.

3. Nonwoven fabric according to claim 1 or 2, characterized in that the dopant is homogeneously distributed only in one component of the fiber body.

4. Nonwoven fabric according to one of claims 1 to 3, characterized in that the dopant is present in a concentration of at least 100 ppm.

5. Nonwoven fabric according to one of claims 1 to 4, characterized in that the dopant is present in a concentration of at most 500 ppm, preferably of at most 100 ppm.

6. Nonwoven fabric according to one of claims 1 to 5, characterized in that the bicomponent fiber comprises a component of polyamide or polyethylene and a component of polyethylene terephthalate or polyester. 7. Nonwoven fabric according to claim 6, characterized in that the bicomponent fiber comprises 30% polyamide or polyethylene.

8. Nonwoven fabric according to claim 6 or 7, characterized in that the dopant is homogeneously distributed in the component of the fiber body, the

Polyethylene terephthalate or polyester.

9. Nonwoven fabric according to one of claims 1 to 8, characterized in that the bicomponent fiber is configured as PIE fiber.

10. Nonwoven fabric according to one of claims 1 to 9, characterized in that the dopant as an element of a subgroup, in particular the subgroup I b, is configured.

11. Nonwoven fabric according to claim 10, characterized in that the dopant is designed as silver, gold or copper.

12. Nonwoven fabric according to one of claims 1 to 11, characterized by a basis weight of at least 20 g / m <2>.

13. Nonwoven fabric according to one of claims 1 to 12, characterized by a coloring.

14. Nonwoven fabric according to one of claims 1 to 13, characterized by a water absorption capacity of at least 350 weight percent of its own weight in the dry state.

15. Nonwoven fabric according to claim 14, characterized by a water absorption capacity after a household wash according to DIN EN ISO 6330 of at least 400 percent by weight of his

Dead weight in dry condition. 16. Use of a nonwoven fabric according to one of the preceding

Claims in a wipe or for making a wipe.