PROCESS FOR OBTAINING A POLYMERIC MATERIAL INCORPORATING METAL PARTICLES

Abstract

The present invention relates to a method for obtaining a polymeric material incorporating metallic particles, a polymeric material incorporating metallic particles and the use of said polymeric material.

Claims

1-11. (canceled)

12. A method for obtaining a polymeric material incorporating metal particles comprising steps of: acid treating the metal particles, and mixing the acid treated metal particles with at least one polymer according to a mass concentration of a mass of treated metal particles relative to a mass of the at least one polymer, comprised between 0.001% and 45%.

13. The method of claim 12, wherein an acid used in the acid treating step is a carboxylic acid.

14. The method of claim 12, wherein an acid used in the step of acid treating is an inorganic acid.

15. The method of claim 13 or claim 14, wherein the acid used in the step of acid treating is selected from a group consisting of formic acid, acetic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, citric acid, a fatty acid, sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, boric acid and hydrobromic acid.

16. The method of claim 13 or claim 14, wherein the acid used in the step of acid treating is selected from a group consisting of acetic acid, citric acid, hydrochloric acid and a fatty acid of rapeseed oil.

17. The method according to claims 12, wherein the step of acid treating is carried out with a mass ratio of an acid relative to the metal particles comprised between 0.5 and 10.

18. The method of claim 12, wherein the step of acid treating is carried out by heating the metal particles within an acid to a temperature less than or equal to a boiling temperature of the acid.

19. The method of claim 12, further comprising the steps of: washing the metal particles treated with acid using an aqueous washing solution, recovering the metal particles after the step of washing the metal particle, and a step of mixing the metal particles with the at least one polymer after the step of recovering the metal particles.

20. The method of claim 12, wherein the metallic particles are selected from a group consisting of particles of aluminum, silver, copper, titanium, palladium, stainless steel, lead, nickel, magnesium, iron, chromium, brass, copper-zinc alloy, cerium, platinum and gold.

21. A method for obtaining a polymeric material incorporating metal particles comprising steps of: acid treating the metal particles, and mixing the acid treated metal particles with at least one polymer according to a mass concentration of a mass of treated metal particles relative to a mass of the at least one prepolymer, comprised between 0.001% and 45%.

22. A polymeric material obtainable by the method of claim 12 or the method of claim 21.

23. A polymeric material incorporating metallic particles of a size greater than 200 nm, the metallic particles being incorporated into the bulk of the polymeric material.

24. A use of the polymeric material of claim 22, as an antimicrobial agent.

25. A use od the polymeric material of claim 23, as an antimicrobial agent.

Description

[0073] The present invention is illustrated, in a nonlimiting manner, by the following examples and the following figures:

[0074] FIG. 1 is a photograph (lens MAGNIFICATION: × 10 and numerical aperture: 0.25) of a make-up brush bristle obtained according to the method described in Example 2, from unpretreated spherical silver particles with a size comprised between 1 and 3 .Math.m and PBT 4000, the particle/PBT mass concentration being 1%.

[0075] FIG. 2 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of a makeup brush bristle obtained according to the method described in Example 2, from spherical silver particles of a size comprised between 1 and 3 .Math.m pretreated with acetic acid and PBT 4000, the mass concentration of particles/PBT being 1%.

[0076] FIG. 3 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of a makeup brush bristle obtained according to the method described in Example 2, from non-pretreated spherical silver particles of a size comprised between 1 and 3 .Math.m and PBT 4000, the mass concentration of particles/PBT being 0.16%.

[0077] FIG. 4 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of a make-up sponge obtained according to the process described in Example 3, from silver particles (flake) of a size comprised between 2 and 5 .Math.m pretreated with acetic acid and a polymer mixture of NBR and SBR (NBR/SBR mass ratio equal to 0.25), the mass concentration of particles/polymer mixture being 0.067 %.

[0078] FIG. 5 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of yarns obtained by the method described in Example 4 before mixing with other yarns (for example, cotton), from spherical silver particles of a size comprised between 1 and 3 .Math.m pretreated with citric acid and PET, the mass concentration of particles/PET being 0.1%.

[0079] FIG. 6 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of yarns obtained by the method described in Example 4 before mixing with other yarns (for example, cotton), from non-pretreated spherical silver particles of a size comprised between 1 and 3 .Math.m and from PET, the mass concentration of particles/PET being 1%.

[0080] FIG. 7 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of yarns obtained by the method described in Example 4 before mixing with other yarns (for example, cotton), from spherical silver particles of a size comprised between 1 and 3 .Math.m pretreated with acetic acid and PET, the mass concentration of particles/PET being 1%.

[0081] FIG. 8 is a photograph (lens magnification: X10 and numerical aperture: ) of yarns obtained by the method described in Example 4 before mixing with other yarns (for example, cotton), from spherical silver particles of a size comprised between 1 and 3 .Math.m pretreated with hydrochloric acid and PET, the particle/PET mass concentration being 0.1%.

[0082] FIG. 9 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of yarns obtained by the method described in Example 4 before mixing with other yarns (for example, cotton), from spherical silver particles of a size comprised between 1 and 3 .Math.m pretreated with rapeseed oil and PET, the particle/PET mass concentration being 0.1%.

[0083] FIG. 10 is a photograph (lens magnification: X40 and numerical aperture: 0.65) of yarns obtained by the method described in Example 4 before mixing with other yarns (for example, cotton), from ground copper sheets with a length comprised between 1 and 8 .Math.m pretreated with acetic acid and PET, the mass concentration of particles/PET being 0.1%.

[0084] FIG. 11 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of yarns obtained by the method described in Example 4 before mixing with other yarns (for example, cotton), from a ground gold leaf with a length comprised between 1 and 8 .Math.m pretreated with acetic acid and PET, the mass concentration of particles/PET being 0.1%.

[0085] FIG. 12 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of yarns obtained by the method described in Example 4 before mixing with other yarns (for example, cotton), from spherical silver particles of a size approximately equal to 200 nm pretreated with acetic acid and PET, the mass concentration of particles/PET being 0.1%.

[0086] FIG. 13 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of yarns obtained by the method described in Example 4 after braiding with cotton yarns, from non-pretreated spherical silver particles of a size comprised between 1 and 3 .Math.m and of PET, the mass concentration of particles/PET being 0.1%.

[0087] FIG. 14 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of yarns obtained by the method described in Example 4 after braiding with cotton yarns, from spherical silver particles of a size comprised between 1 and 3 .Math.m pretreated with acetic acid and of PET, the mass concentration of particles/PET being 4%.

[0088] FIG. 15 is a photograph (lens magnification: X4 and numerical aperture: 0.10) of a PET yarn comprising silver particles sold under the name X-STATIC®.

[0089] FIG. 16 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of a silicone spatula obtained by the method described in Example 5, from silver particles (flake) of a size comprised between 2 and 5 .Math.m pretreated with acetic acid and silicone, the particle/silicone mass concentration being 1%.

[0090] FIG. 17 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of a silicone spatula obtained by the method described in Example 5, from silver particles (flake) of a size comprised between 2 and 5 .Math.m pretreated with citric acid and silicone, the particle/silicone mass concentration being 1%.

[0091] FIG. 18 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of a silicone spatula obtained by the method described in Example 5, from silver particles (flake) of a size comprised between 2 and 5 .Math.m pretreated with citric acid and silicone, the particle/silicone mass concentration being 5%

[0092] FIG. 19 is photograph of a cross section (lens magnification: X10 and numerical aperture: 0.25) of a silicone spatula obtained by the method described in Example 5, from spherical silver particles of a size comprised between 1 and 3 .Math.m pretreated with citric acid and silicone, the particle/silicone mass concentration being 1%.

[0093] FIG. 20 is a photograph (lens magnification: X10 and numerical aperture: 0.25) of a cross section of a silicone spatula obtained by the method described in Example 5, from non-pretreated spherical silver particles of a size comprised between 1 and 3 .Math.m and of silicone, the mass concentration of particles/silicone being 1%.

EXAMPLE 1: METHOD FOR TREATING METAL PARTICLES

[0094] Metal particles (Atlantic Equipment Engineers, Micron Metals Inc., with a 99.99% purity) are introduced into a bath of aqueous acid solution, with a particle/acid mass ratio equal to 1, then mixed with the aid of a glass rod so that they are completely impregnated with the solution.

[0095] Alternatively, metal particles (Atlantic Equipment Engineers, Micron Metals Inc.) are introduced into a rapeseed oil bath, the particle/oil mass ratio being equal to 1, then mixed using a glass rod so that they are completely impregnated with oil.

[0096] Alternatively, the metal particles (Atlantic Equipment Engineers, Micron Metals Inc.) are mixed with a powdered acid for 10 minutes using an amalgamator-mixer at a speed of 300 revolutions per minute (rpm), the particle/acid mass ratio being equal to 1. Friction generates a temperature rise.

[0097] The bath is then heated to a temperature dependent on the used acid or on the oil used until evaporation of the solution to obtain wet particles: [0098] acetic acid: about 118° C., [0099] citric acid: about 175° C., [0100] hydrochloric acid: about 109° C., [0101] rapeseed oil: between 180 and 232° C.

[0102] The latter are then washed with distilled water and then filtered on a filter paper (pore size between 17 and 30 .Math.m) successively until a neutral pH (pH of approximately 7) is obtained.

[0103] They are then dried in an oven at 60° C. for at least 1 hour.

[0104] Once dry, these particles can be stored in open air for at least 5 days without affecting the rest of the process.

[0105] In Examples 2 to 5 below, all the analyses were carried out using a microscope (Senecope Lab Binocular compound 40 × 2500 × LED).

EXAMPLE 2: METHOD OF MANUFACTURING BRISTLES FOR MAKEUP BRUSHES

[0106] The metal particles obtained according to the method described in Example 1 (use of an aqueous acid solution) are mixed with granules of PBT 4000 (Chang Chun Chemical Ltd China) using an amalgamator-mixer at a speed of 150 revolutions per minute (rpm) for 2 to 5 minutes. The mixture is then melted at 255° C.

[0107] The molten mixture is passed through an extruder, then through a die and finally cooled in a water bath in order to obtain yarns of 0.06 mm in diameter.

[0108] The yarns are then left to air-dry and will serve as bristles for makeup brushes.

[0109] Various tests were carried out by varying the source of the metal particles as well as the quantities of metal particles and of PBT and are summarized in Table 1, the concentration by mass of particles/PBT representing the ratio by mass of metal particles/PBT before their mixing.

TABLE-US-00001 Trial Particle Source Particle mass PBT mass Particle/PBT mass concentration A Silver, spherical 1-3 .Math.m without treatment 10 g 1 kg 1% B Silver, spherical 1-3 .Math.m, acetic acid 10 g 1 kg 1% C Silver, spherical 1-3 .Math.m without treatment 8 g 5 kg 0.16%

[0110] The yarns obtained according to trials A and C were analyzed by microscope, the results being shown in FIG. 1 for trial A and in FIG. 3 for trial C. Furthermore, the results of trial B are shown in FIG. 2. The comparison of these figures highlights the incorporation of the metal particles inside the polymer yarn only if they underwent beforehand a treatment according to the method of Example 1 (FIG. 2). Indeed, the particles remain on the surface of the polymer yarn when they did not undergo the method of Example 1, which confers a granulous aspect to the yarn, shown in FIG. 1 and FIG. 3. In addition, FIG. 3 shows the presence of notches in the polymer, around the particles, that are not observed in FIG. 2.

EXAMPLE 3: METHOD FOR MANUFACTURING MAKE-UP SPONGES

[0111] Different polymers are used in this example: NBR liquid (for “Nitrile Butadiene Rubber”) and SBR liquid (for “Styrene Butadiene Rubber”), both supplied by Aero Rubber Company, or polyurethane with an additive composed of wollastonite powder, silane and water.

[0112] The metal particles obtained by the method described in Example 1 (use of an aqueous acid solution) are mixed with various polymers using an amalgamator-mixer at a speed of 300 rpm for 2 to 5 minutes. The mixture is then melted at 90° C. and then poured into molds.

[0113] The molds are then cooled to 10° C. by a water flow, which allows the formation of the sponge structure.

[0114] The sponges are then cut and polished.

[0115] The conditions of the various trials carried out are summarized in Table 2, the particle/polymer mixture mass concentration representing the metal particle/polymer mixture mass ratio before mixing.

TABLE-US-00002 Trial Particle Source Particle mass Mass of NBR Mass of SBR Polyurethane mass Additive Particle/polymer mixture mass concentration D Silver, flake 2-5 .Math.m , acetic acid 10 g 3 kg 12 kg - - 0.067% E Silver, flake 2-5 .Math.m , acetic acid 7.5 g 3 kg 12 kg - - 0.05% F Silver, spherical 1-3 .Math.m, acetic acid 10 g - - 15 kg 15 kg 0.033% G Silver, flake 2-5 .Math.m , acetic acid 30 g - - 15 kg 15 kg 0.1%

[0116] The sponges obtained according to trials D to G were analyzed by microscope. These have all a similar structure, an example of which is shown in FIG. 4. This figure shows that, for different polymer mixtures, the metal particles are incorporated inside the polymer mixture, independently of the shape of the particles.

EXAMPLE 4: METHOD FOR MANUFACTURING YARNS FOR OBTAINING A FABRIC

[0117] The metal particles obtained according to the process described in Example 1 (use of an aqueous solution of acid or oil for trial L) are mixed with polyethylene terephthalate or “PET” granules (supplier: Techmer PM) using an amalgamator-mixer at a speed of 150 rpm for 2 to 5 minutes.

[0118] The mixture is conveyed at 315° C. by a worm to a die and finally cooled by thermal shock in order to obtain transparent strands. These strands are combined into yarns of about 10 .Math.m in diameter.

[0119] The yarns are then left to dry in the open air and may then be mixed with other yarns, for example of cotton, with the aim to obtaining a fabric, for example by braiding.

[0120] Various trials were carried out by varying the source of the metal particles as well as the quantities of metal particles and of PET and are summarized in Table 3, the mass concentration of particles/PET representing the mass ratio of metal particles/PET before their mixture.

TABLE-US-00003 Trial Particle Source Particle mass Mass of PET Particle/PBT mass concentration H Silver, spherical 1-3 .Math.m without treatment 10 g 1 kg 1% I Silver, spherical 1-3 .Math.m, acetic acid 10 g 1 kg 1% J Silver, spherical 1-3 .Math.m, citric acid 1 g 1 kg 0.1% K Silver, spherical 1-3 .Math.m , hydrochloric acid 1 g 1 kg 0.1% L Silver, spherical 1-3 .Math.m , rapeseed oil 1 g 1 kg 0.1% M Ground copper sheets, length 1-8 .Math.m, acetic acid 1 g 1 kg 0.1% N Ground gold sheets, length 1-8 .Math.m, acetic acid 1 g 1 kg 0.1% O Silver, spherical 200 nm, acetic acid 1 g 1 kg 0.1% P Silver, spherical 1-3 .Math.m without treatment 1 g 1 kg 0.1% Q Silver, spherical 1-3 .Math.m, acetic acid 40 g 1 kg 4%

[0121] The yarns obtained according to trials H (comparative), I and J were analyzed by microscope, the results being shown in FIGS. 6, 7 and 5 respectively.

[0122] FIG. 6 shows the presence of notches in the polymer, around the particles, which are not observed in FIG. 7 or in FIG. 5. In addition, the surface of the polymer in FIG. 6 is irregular, unlike the polymer in FIGS. 7 or 5.

[0123] By way of comparison, a PET yarn comprising silver particles sold under the name X-STATIC ® was analyzed by microscope (FIG. 15). This FIG. 15 clearly shows that the silver particles are not incorporated inside the polymer but are located on its surface. FIGS. 8 to 12, obtained for particles pretreated according to the invention (trials K to O respectively), show results similar to FIGS. 5 and 7.

[0124] These differences demonstrate that the metal particles are incorporated inside the polymer only in the case where they have previously undergone a treatment according to the method of Example 1. The yarns obtained according to trials P and Q were then braided with cotton yarns (FIGS. 13 and 14 respectively).

[0125] The differences are significant: FIG. 13 shows that the particles are on the surface of the polymer, while they are incorporated into the polymer in FIG. 14.

EXAMPLE 5: METHOD FOR MANUFACTURING A SILICONE ARTICLE

[0126] Silicone plates (polydimethylsiloxane) are melted at a temperature comprised between 50 and 1185° C. then the metal particles obtained by the method described in Example 1 (use of an aqueous acid solution) are added and the medium is homogenized using an amalgamator-mixer at a rate of 120 rpm for 2 to 5 minutes.

[0127] The mixture is then poured into molds and allowed to cool to room temperature.

[0128] The conditions of the different trials carried out are summarized in Table 4.

TABLE-US-00004 Trial Particle Source Particle mass Silicone mass Particulate/silicone mass concentration R Silver, flake 2-5 .Math.m, acetic acid 10 g 1 kg 1% S Silver, flake 2-5 .Math.m, citric acid 10 g 1 kg 1% T Silver, flake 2-5 .Math.m, citric acid 50 g 1 kg 5% U Silver, spherical 1-3 .Math.m, citric acid 10 g 1 kg 1% V Silver, spherical 1-3 .Math.m without treatment 10 g 1 kg 1%

[0129] The articles obtained according to the R to U trials were analyzed by microscope, the results being shown in particular in FIGS. 16 to 19. These figures show that, for different particle/silicone concentrations, the metal particles are well incorporated inside the silicone, regardless of the acid used to treat the metal particles before their incorporation.

[0130] In addition, contrary to what is observed for FIG. 19 (trial U) the particles present on the surface of the silicone of FIG. 20 (trial V) disappear in 3D.

EXAMPLE 6 ASSESSMENT OF THE ANTIMICROBIAL ACTIVITY OF MAKEUP BRUSH BRISTLES ESCHERICHIA COLI

[0131] Makeup brush bristles obtained by the method described in Example 1 (silver, spherical 1-3 microns, acetic acid) and by the method described in Example 2 (mass concentration particles / PBT equal to 0.1 %), from the treated particles according to the invention, were tested to determine their antimicrobial activity according to the method described in ASTM E2149-13 (“Standard Test Method for Determining the Antimicrobial Activity of Immobilized Antimicrobial Agent Under Dynamic Contact Conditions”).

[0132] This method makes it possible to assess the resistance of samples treated with a non-leachable antimicrobial to the development of microbes under dynamic contact conditions.

[0133] Antimicrobial activity was determined by shaking 1 g of the above-mentioned bristles in a bacterial suspension inoculated with 2.48.10.sup.5 cfu/mL of Escherichia coli (ATCC 25922) for 1 hour at room temperature (23 ± 2° C.).

[0134] The results (mean values) for control broth and bristles (polymeric material) are shown in Table 5.

TABLE-US-00005 Sample Control broth Polymeric material Time 0 1 hour 1 hour E. coli (cfu*/mL) 2.61 10.sup.5 3.35 10.sup.5 1.78 10.sup.1 * Colony Forming Unit

[0135] Thus, the use of bristles obtained by the methods described in Examples 1 and 2 allows a reduction of 99.99% of the number of bacteria.

[0136] These results highlight the strong antimicrobial activity of the polymeric material obtained from the treated particles according to the invention.

EXAMPLE 7 ASSESSMENT OF THE ANTIMICROBIAL ACTIVITY OF MAKEUP BRUSH BRISTLES STAPHYLOCOCCUS AUREUS

[0137] PBT makeup brush bristles obtained from particles treated according to the methods described in Examples 1 and 2 (spherical silver particles 1-3 microns, acetic acid), with a mass concentration / PBT of 1%, were tested to determine their antimicrobial activity according to the method described in ASTM E2180 (“Standard method for Determining the Antimicrobial Activity of Incorporated Antimicrobial Agent (s) in Polymeric or Hydrophobic Material”).

[0138] This method makes it possible to assess the resistance of polymeric samples treated with an antimicrobial to the development of microbes under dynamic contact conditions. The antimicrobial activity was determined by contacting 3 × 3 cm flattened samples of the above-mentioned bristles with an agar agar gel inoculated with 1-5 × 10.sup.6 cells/mL of Staphylococcus aureus (ATCC 6538) for 24 hours in an incubator at a temperature of 35° C. under aerobic conditions.

[0139] The results (mean values) for the control sample and the bristles (polymeric material) are shown in Table 5.

TABLE-US-00006 Sample Contact time Replica cfu/ml S. aureus (Avg) Decrease percentage Control 0 h 1 1.09×10.sup.6 2 1.08×10.sup.6 1.083×10.sup.6 - 3 1.08×10.sup.6 Control 24 h 1 4.4×10.sup.6 2 6.2×10.sup.6 5.57x10.sup.6 - 3 6.1×10.sup.6 Polymeric material 24 h 1 2.6×10.sup.3 2 7.75×10.sup.3 4.23×10.sup.3 99.92% 3 2.35×10.sup.3

[0140] Thus, the use of the bristles obtained in Example 2 allows a reduction of 99.92% of the number of bacteria Staphylococcus aureus ATCC #6538.

[0141] These results highlight the strong antimicrobial activity of the polymeric material obtained from the treated particles according to the invention.

EXAMPLE 8 ASSESSMENT OF THE ANTIMICROBIAL ACTIVITY OF MAKEUP BRUSH BRISTLES PSEUDOMONAS AERUGINOSA

[0142] PBT make-up brush bristles obtained according to the methods described in Example 1 (1-3 .Math.m spherical silver particles, citric acid) and in Example 2 (particle/PBT mass concentration equal to 1%) have been tested to determine their antimicrobial activity by following the method described in ASTM E2149-13 (“Standard Test method for Determining the Antimicrobial Activity of Immobilized Antimicrobial Agents Under Dynamic Contact Conditions”).

[0143] This method makes it possible to assess the resistance of samples treated with a non-leachable antimicrobial to the development of microbes under dynamic contact conditions.

[0144] Antimicrobial activity was determined by shaking 1 g of the above-mentioned bristles in a bacterial suspension inoculated with 6.60 10.sup.5 cfu/mL of Pseudomonas aeruginosa (ATCC 15442) for 1 hour at room temperature (23 ± 2° C.).

[0145] The results (mean values) for the control broth and the bristles (polymeric material) are shown in Table 7.

TABLE-US-00007 Sample Control broth Polymeric material Time 0 1 hour 1 hour Pseudomonas aeruginosa (cfu*/mL) 6.05×10.sup.5 3.45×10.sup.5 2.24×10.sup.4 * Colony Forming Unit

[0146] Thus, the use of bristles obtained by the methods described in Examples 1 and 2 allows a reduction of 93.51% of the number of bacteria Pseudomonas aeruginosa (ATCC 15442).

[0147] These results highlight the strong antimicrobial activity of the polymeric material obtained from the treated particles according to the invention.

EXAMPLE 9: ASSESSMENT OF THE ANTIMICROBIAL ACTIVITY OF YARNS FOR THE PRODUCTION OF A FABRIC:

Escherichia Coli

[0148] Yarns for obtaining a fabric obtained from particles treated according to the invention (silver, spherical 1-3 .Math.m, acetic acid) and according to the method described in Example 4 (particle/PET mass concentration of 4%) were tested to determine their antimicrobial activity by following the method described in ASTM E2180 (“Standard method for Determining the Antimicrobial Activity of Incorporated Antimicrobial Agent(s) in Polymeric or Hydrophobic Material”).

[0149] This method makes it possible to assess the resistance of polymeric samples treated with an antimicrobial to the development of microbes under dynamic contact conditions. The antimicrobial activity was determined by contacting 3 × 3 cm flattened samples of the above-mentioned yarns with an agar agar gel inoculated with 1-5 × 10.sup.6 cells/mL of Escherichia Coli (ATCC 8739) for 24 hours in an incubator at a temperature of 35° C. under aerobic conditions.

[0150] The results (mean values) for the control sample and the yarns (polymeric material) are shown in Table 8.

TABLE-US-00008 Sample Contact time Replica cfu/ml E. coli (Avg) Decrease percentage Control 0 h 1 1.21×10.sup.6 1.66×10.sup.6 - 2 2.02×10.sup.6 3 1.88×10.sup.6 Control 24 h 1 6.20×10.sup.6 1.21×10.sup.7 - 2 1.68×10.sup.7 3 1.69×10.sup.7 Polymeric material 24 h 1 <10 <10 99.9999% 2 <10 3 <10

[0151] Thus, the use of yarns obtained by the methods described in Examples 1 and 4 allows a reduction of 99.9999% of the number of Escherichia Coli (ATCC 8739) bacteria.

[0152] These results highlight the strong antimicrobial activity of the polymeric material obtained from the treated particles according to the invention.