A METHOD FOR PREPARATION OF VIRUCIDAL POLYMER TEXTILE MATERIALS AND VIRUCIDAL FACE MASKS MADE FROM SAID MATERIALS

Abstract

Methods for the treatment of textiles used for facial masks assure for the inactivation of viruses captured by the textile. The aerosol droplets are absorbed by the textile, and any viruses in the water droplets react with a virucidal substance. The surface of textile fibers is first exposed to gaseous plasma to assure appropriate wettability. The textile is then soaked in a diluted water solution of a virucidal substance. The excessive water solution is optionally removed by draining, and the drained textile is then dried. The methods enable uniform coating of the textile fibers with an extremely thin film of virucidal substance. A typical concentration of the virucidal substance in the textiles treated according to the methods of the aspects of disclosed embodiments is about 10 g/kg. Such a small concentration is benign to humans but effectively inactivates the viruses that might be captured by the textile.

Claims

1. A method for preparation of virucidal polymer textile materials, comprising the following steps: a) material pre-treatment using non-equilibrium gaseous plasma at a pressure below 1000 Pa, the gaseous plasma comprising at least 5 vol % oxygen or water vapor with the fluence of reactive particles between 310.sup.22 m.sup.2 and 310.sup.25 m.sup.2; b) treatment of the pre-treated material obtained in step a) with a diluted solution of a virucidal substance, wherein the virucidal substance is a water solution with a concentration in the range from 0.05 to 15% (w/w), and c) drying the material treated in step b) at a temperature below 100 C.

2. The method for preparation of virucidal polymer textile materials according to claim 1, wherein a draining step is performed before drying in order to shorten drying times.

3. The method for preparation of virucidal polymer textile materials according to claim 1, wherein the drying step assures that the final amount of active substance is 0.05 to 3%, preferably 1%, by weight of the material.

4. The method for preparation of virucidal polymer textile materials according to claim 1, wherein material pre-treatment is achieved with a combination of non-equilibrium gaseous plasma with the fluence of reactive oxygen particles between 310.sup.21 m.sup.2 and 310.sup.24 m.sup.2 and the fluence of VUV photons, arising from the said plasma, between 110.sup.19 m.sup.2 and 310.sup.22 m.sup.2.

5. The method for preparation of virucidal polymer textile materials according to claim 1, wherein the virucidal substance may be any suitable substance, preferably selected in the group consisting of: sodium oleate, sodium laureate, sodium dodecyl sulphate (SDS), Triton X-100, quaternary ammonium, rhamnolipids, saponins, Tween, 3-[(3-Cholamidopropyl)dimethylammonio]-1-propanesulfonate hydrate (CHAPS), benzyldimethyldodecylammonium chloride (BMC), sodium octyl sulphate, ammonium dodecyl sulphate; most preferably the virucidal substance is 0.3 to 3% (w/w) SDS.

6. The method for preparation of virucidal polymer textile materials according to claim 1, wherein the mass of the virucidal substance on the dried mask textile is about 10 grams of virucidal substance per kilogram of dry textile.

7. The method for preparation of virucidal polymer textile materials according to claim 1, wherein drying in step c) is performed by dry-air blowing, infra-red and/or microwave drying, or vacuum drying.

8. The method for preparation of virucidal polymer textile materials according to claim 1, wherein the materials are preferably textiles, either woven or non-woven, preferably made from polyethylene, polypropylene, polyesters as well as biodegradable polymers like polylactic acid, most preferably polypropylene (PP) and polyethylene terephthalate (PET).

9. A method for preparation of virucidal polymer textile materials, comprising the following steps: (a) material pre-treatment by the VUV photons, arising from any source including the gaseous plasma, with the photon fluence between 310.sup.20 m.sup.2 and 310.sup.24 m.sup.2 and exposing the polymeric material to ambient air; b) treatment of the pre-treated material obtained in step a) with a diluted solution of a virucidal substance, wherein the virucidal substance is a water solution with a concentration in the range from 0.05 to 15% (w/w), and c) drying the material treated in step b) at a temperature below 100 C.

10. The method for preparation of virucidal polymer textile materials according to claim 9, wherein material treatment with virucidal substance is achieved by soaking, dipping, spraying, roll-coating and immersing, most preferably by soaking or dipping.

11. The method for preparation of virucidal polymer textile materials according to claim 9, wherein the virucidal substance may be any suitable substance, preferably selected in the group consisting of: sodium oleate, sodium laureate, sodium dodecyl sulphate (SDS), Triton X-100, quaternary ammonium, rhamnolipids, saponins, Tween, 3-[(3-Cholamidopropyl)dimethylammonio]-1-propanesulfonate hydrate (CHAPS), benzyldimethyldodecylammonium chloride (BMC), sodium octyl sulphate, ammonium dodecyl sulphate; most preferably the virucidal substance is 0.3 to 3% (w/w) SDS.

12. The method for preparation of virucidal polymer textile materials according to claim 9, wherein the mass of the virucidal substance on the dried mask textile is about 10 grams of virucidal substance per kilogram of dry textile.

13. The method for preparation of virucidal polymer textile materials according to claim 9, wherein drying in step c) is performed by dry-air blowing, infra-red and/or microwave drying, or vacuum drying.

14. The method for preparation of virucidal polymer textile materials according to claim 9, wherein the materials are preferably textiles, either woven or non-woven, preferably made from polyethylene, polypropylene, polyesters as well as biodegradable polymers like polylactic acid, most preferably polypropylene (PP) and polyethylene terephthalate (PET).

15. A device for preparation of virucidal polymer textile materials, wherein the device comprises at least the following: a suspender with a roll of suitable material or textile to be treated, a vacuum chamber next to the suspender, wherein the textile roll is led through the vacuum chamber for pre-treatment, a bath or suitable vessel filled with a suitable solution of the virucidal substance, said bath being arranged for receiving at least a part of the textile roll after pre-treatment, an optional draining unit installed downstream of the bath for removing excessive water solution of the virucidal substance, and a drying unit for drying at least a part of the textile roll; and wherein the preparation of the virucidal polymer textile material comprises: a) material pre-treatment using non-equilibrium gaseous plasma at a pressure below 1000 Pa, the gaseous plasma comprising at least 5 vol % oxygen or water vapor with the fluence of reactive particles between 310.sup.22 m.sup.2 and 310.sup.25 m.sup.2; b) treatment of the pre-treated material obtained in step a) with a diluted solution of a virucidal substance, wherein the virucidal substance is a water solution with a concentration in the range from 0.05 to 15% (w/w), and c) drying the material treated in step b) at a temperature below 100 C.

16. A medical and/or hygienic product made from materials prepared according claim 1.

17. Virucidal medical and/or hygienic products according to claim 12, wherein said products are virucidal face masks.

18. A virucidal face mask comprising a material treated with the method according to claim 1, wherein the material forms an outermost layer of the mask.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The aspects of the disclosed embodiments will be further described based on exemplary embodiments, examples, and figures, which show:

[0037] FIG. 1 a schematic of the method according to the aspects of the disclosed embodiments.

[0038] FIG. 2 a schematic of the method of the aspects of the disclosed embodiments suitable for the treatment of mask textiles in a continuous manner

[0039] FIG. 3 the concentration of infective bacteriophage phi6 virus on polypropylene textiles treated according to the methods of aspects of the disclosed embodiments versus the concentration of SDS in the water solution. The dashed line represents the concentration of virus for untreated textile (control).

[0040] FIG. 4 the concentration of the infective virus in the textile treated according to the methods of the aspects of the disclosed embodiments versus aging time of the virucidal textiles.

[0041] FIG. 5 comparison of concentrations of infective bacteriophage phi6 virus on polypropylene textiles treated according to the methods of aspects of the disclosed embodiments versus selected concentrations of SDS (1%), CHAPS (12.3, 1.23, and 0.12%), and BMC (0.68, 0.068, and 0.0068%) in the water solution. The dashed line represents the concentration of virus for untreated textile (control).

DETAILED DESCRIPTION

[0042] The method for preparation of virucidal materials according to a first embodiment is schematically shown in FIG. 1 and comprises the following main steps: [0043] material pre-treatment using oxygen plasma, to obtain a hydrophilized material; [0044] soaking the hydrophilized material in a diluted water solution of a virucidal substance (preferably SDS), the preferred concentration range of the virucidal substance being from 0.05 to 15% (w/w), for SDS from 0.3 to 3% (w/w), and [0045] drying the material by hanging at room temperature.

[0046] The as-produced textile is provided as shown in panel 1, pre-treated with plasma (panel 2), then soaked in the provided diluted water solution of the selected virucidal substance (panel 3), optionally drained (panel 4) to remove excess water, and thereafter dried (panel 5) in order to obtain the textile (panel 6) useful for products for which inactivation of viruses is required, needed or preferred.

[0047] In a preferred embodiment, the as-synthesized textile is mounted in a vacuum chamber. The chamber is evacuated to the ultimate pressure, which is, in the preferred embodiment, between 0.1 and 10 Pa. The vacuum chamber at ultimate pressure contains a residual atmosphere, i.e., gases or vapours that remain in the vacuum chamber after achieving the ultimate pressure. The residual atmosphere usually comprises water vapor, while the concentration of other gases or vapours is smaller than the concentration of water vapor. The evacuation of the vacuum chamber is realized using a vacuum pump. The type of the pump is not particularly limited. Once the ultimate pressure has been achieved, gaseous plasma is ignited in the vacuum chamber. Plasma at low pressure is ignited by any discharge, including the direct-current (DC), alternating-current (AC), radio-frequency (RF), and microwave (MW) discharges. The discharge power is not particularly limited, but the best results in terms of rapid pre-treatment of the textiles are achieved at the power density of between 1 and 10 kW per square meter of the textile.

[0048] In another embodiment, the vacuum chamber is filled with a reactive gas. The reactive gas could be oxygen, nitrogen, hydrogen, or a noble gas. The pressure of reactive gas is not particularly limited, but the best results are obtained in the range of pressures between about 0.1 and 100 Pa. This pressure range assures uniform plasma in the entire volume of the vacuum chamber. Pure oxygen or oxygen-containing gas like water vapor, hydrogen peroxide vapor, carbon dioxide, sulphur oxides, and nitric oxides were found particularly useful for the pre-treatment of textiles. The as-synthesized textile is placed into the vacuum chamber, which is filled with a reactive gas, plasma is ignited and sustained for an appreciable time to assure appropriate pre-treatment of the textile. The plasma treatment time is not particularly limited, but it is between 0.1 and 100 s in the preferred embodiment.

[0049] Once the textile is pre-treated, it is soaked in a suitably diluted virucidal agent, most preferably in 0.5% (w/w) water solution of sodium dodecyl sulphate (SD S), with sufficient volume to achieve the final concentration of 1% (w/w) of active ingredient per weight of the material, preferably below 1.3%. The soaking time is not particularly limited, but for practical reasons, it is between 1 and 100 s.

[0050] After soaking in the diluted solution of the virucidal substance, preferably in the 0.5% (w/w) water solution of SDS, the textile is drained and then dried. Draining is optional and enables the removal of excessive water solution of the virucidal substance. The method for draining is not particularly limited; it could be gentle centrifugation. The (optionally) drained textile is then dried to remove water. The virucidal substance remains on the surface of fibers in the textile after drying. The textile treated according to the methods of the aspects of the disclosed embodiments is ready for manufacturing of masks.

[0051] A method useful for mass treatment of the textiles for masks is shown schematically in FIG. 2. The as-synthesized textile is mounted on a roll 21. The textile 22 passes through a vacuum chamber 23, where it is pre-treated with gaseous plasma. The pre-treated textile then passes a bath filled with a liquid solution of the virucidal substance 24 where it is soaked. The soaked textile then passes the draining unit 25 to remove excessive water solution of the virucidal substance. The drained textile then enters a drying unit 26, where it is dried. The draining unit is optionalit is used in the preferred embodiment to shorten the drying time. Finally, the textile is re-rolled 27 and ready for use in manufacturing of products, especially face masks.

EXAMPLES

[0052] The inactivation of viruses in the textile treated according to the methods of the aspects of the disclosed embodiments was measured by ISO 18184Determination of the antiviral activity of textile products standard.

Example 1: SDS (Sodium Dodecyl Sulphate) as a Virucidal Compound

[0053] The textile was commercial material used for surgical masks, i.e., polypropylene. The textile was treated by the methods of the aspects of the disclosed embodiments and then probed for virus inactivation. The plasma treatment was performed at the following conditions: The residual atmosphere at the pressure of 4.6 Pa, the plasma treatment time of 10 s, using an electrodeless RF discharge in the E-mode, discharge power density was 10 W/cm.sup.2. In this example, the plasma was sustained in water vapour (water contains 33 at. % oxygen). The fluence of reactive oxygen species was 310.sup.23 m.sup.2 and the fluence of VUV radiation 210.sup.21 m.sup.2. The concentration of the infective virus in the textile treated according to the methods of the aspects of the disclosed embodiments, is shown in FIG. 3 versus the concentration of SDS in the water solution. The concentration of 1% (w/w) is useful for inactivation of the virus concentration for 7-log. The control samples were tested at identical conditions but without plasma pre-treatment of the textile.

Example 2: Temporal Stability of SDS as a Virucidal Compound on a Surgical Mask

[0054] The textile was commercial material used for surgical masks, i.e., polypropylene. To determine the temporal stability of the virucidal layer, several same textiles were treated by the methods of the aspects of the disclosed embodiments and then probed for virus inactivation immediately after treatment and in specific time frames after treatment. The plasma treatment was performed at the following conditions: The residual atmosphere at the pressure of 4.6 Pa, the plasma treatment time of 10 s, using an electrodeless RF discharge in the E-mode, discharge power density was 10 W/cm.sup.2. After plasma treatment, the concentration of 1% (w/w) was applied to textiles, which were dried. The concentration of the infective virus in the textile treated according to the methods of the aspects of the disclosed embodiments is shown in FIG. 4 versus aging time of the virucidal textiles. The virus was still inactivated up to 7-log even after 62 days of storage at ambient conditions.

Example 3: BMC (Benzyldimethyldodecylammonium Chloride) as a Virucidal Compound

[0055] The textile was commercial material used for surgical masks, i.e., polypropylene. The textile was treated by the methods of the aspects of the disclosed embodiments and then probed for virus inactivation. The plasma treatment was performed at the following conditions: The residual atmosphere at the pressure of 4.6 Pa, the plasma treatment time of 10 s, using an electrodeless RF discharge in the E-mode, discharge power density was 10 W/cm.sup.2. From FIG. 5, it can be seen that the concentration of 12.3% (w/w) is useful for inactivation of the virus concentration for 7-log, while lower concentrations, 1.23 and 0.12%, lower the inactivation of the virus concentration to 4-log and 2.5-log, respectively. The control samples were tested at identical conditions but without plasma pre-treatment of the textile.

Example 4: CHAPS (3-[(3-Cholamidopropyl)dimethylammonio]-1-propanesulfonate hydrate) as a Virucidal Compound

[0056] The textile was commercial material used for surgical masks, i.e., polypropylene. The textile was treated by the methods of the aspects of the disclosed embodiments and then probed for virus inactivation. The plasma treatment was performed at the following conditions: The residual atmosphere at the pressure of 4.6 Pa, the plasma treatment time of 10 s, using an electrodeless RF discharge in the E-mode, discharge power density was 10 W/cm.sup.2. The concentration of 0.68% (w/w) is useful for the inactivation of the virus concentration for 7-log, while lower concentrations, 0.068 and 0.0068%, lower the inactivation of the virus concentration to almost 6-log and 2-log, respectively. The control samples were tested at identical conditions but without plasma pre-treatment of the textile.

[0057] The absorbing capacity between different layers of a surgical mask is different. The water-diluted sodium dodecyl sulphate (SDS) cannot be absorbed into the outer and the inner layer (made of polypropylene) at below 5.7% (w/w), while SDS cannot absorb into the middle layer (made of polyethylene terephthalate) below 0.5% (w/w).