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EP-4125476-B1 - POROUS BIOCIDAL FILTER

EP4125476B1EP 4125476 B1EP4125476 B1EP 4125476B1EP-4125476-B1

Inventors

  • ZUSSMAN, EYAL

Dates

Publication Date
20260506
Application Date
20210330

Claims (13)

  1. A biocidal non-woven matrix comprising an electrospun nanofiber comprising at least one polymer selected from a cationic polymer, a non-ionic polymer and an anionic polymer or a combination thereof, wherein: a diameter of said electrospun nanofiber is between 50 to 1500 nanometers; a surface of said matrix is characterized by a water contact angle of less than 90°; the matrix comprises a plurality of pores and is characterized by a porosity suitable for capturing a microbe in a range between 50 and 400 nm; said porosity is at least 80%, and said plurality of pores is characterized by a median pore size in a range between 60 and 800 nanometers; wherein said porosity allows for air permeability, k between 10 -7 [m 2 ] and 10 -5 [m 2 ] for flow rate of 8 L/min; and wherein said matrix further comprises between 0.1 and 40% of a biocidal agent by weight of said matrix.
  2. The biocidal non-woven matrix of claim 1, wherein said biocidal agent is in contact with said electrospun nanofiber and is homogeneously dispersed within said matrix; wherein said biocidal agent comprises a bactericidal agent, a virucidal agent, or both; optionally wherein said biocidal agent is selected from the group consisting of poly(vinyl pyrrolidone iodine) (PVP-I), and Chlorhexidine digluconate, Didecyldimethylammonium chloride (DDAC), Silver and Copper ions.
  3. The biocidal non-woven matrix of claim 1 or 2, wherein said at least one polymer is selected from the group consisting of polycaprolactone (PCL), poly(vinyl pyrrolidone) (PVP), poly(vinyl alcohol) (PVA), poly(lactic-co-glycolic acid) (PLGA), polylactic acid (PLA), polyglycolic acid (PGA), poly(vinylidene fluoride-co-hexafluoropropylene) and polysulfone, or any combination thereof.
  4. The biocidal non-woven matrix of anyone of claims 1 to 3, further comprising a pH reducing agent wherein the pH reducing agent lowers the pH to less than 5 at a location within said matrix when in contact with a liquid droplet.
  5. The biocidal non-woven matrix of any one of claims 1 to 4, being in a form of a layer having a thickness of 10 to 500 micrometers; optionally wherein said biocidal non-woven matrix is further in contact with an adhesive layer; and wherein said biocidal non-woven matrix is characterized by a pressure drop of less than 5 Pa/cm 2 at a flow rate of 8 L/min.
  6. A multi-layered article comprising a first layer comprising the biocidal non-woven matrix of any one of claims 1 to 5 bound to an additional layer, wherein said additional layer comprises a non-woven matrix comprising a plurality of polymeric microfibers; and wherein said multi-layered article is characterized by air pressure drop of less than 49 Pa/cm 2 .
  7. The multi-layered article of claim 6, wherein said polymeric microfibers are spun-bond, or spun lace fibers; and wherein said polymeric microfibers comprise a polymer selected from the group consisting of: a polyolefin, a polyester, and a polyamide, optionally wherein said polymer is selected form polyethylene, polypropylene, and polyethylene terephthalate, including any combination or a copolymer thereof.
  8. The multi-layered article of claim 6 or 7, wherein any one of: the textile weight of said additional layer is between 40 to 60 g/m 2 ; a thickness of said additional layer is between 100 to 500 microns; an outer surface of said additional layer comprises an adhesive layer; and optionally wherein said adhesive layer comprises a pressure sensitive adhesive.
  9. The multi-layered article of claim 8, adhered to a substrate via said adhesive layer and is characterized by an increase of air pressure drop of about 10%, compared to air pressure drop of said substrate; and wherein the multi-layered article is a face mask.
  10. A process for manufacturing the multi-layered article of any one of claims 6 to 9, comprising (i) manufacturing a fibrous mat by electrospinning a polymeric solution, thereby obtaining said fibrous mat comprising an electrospun nanofiber comprising at least one polymer selected from a cationic polymer, a non-ionic polymer and an anionic polymer or a combination thereof; said electrospun nanofiber has a diameter between 50 to 1500 nanometers; said fibrous mat has a porosity of at least 80% and is characterized by a median pore size in a range between 60 and 800 nanometers; (ii) applying a composition comprising a biocidal agent on said fibrous mat, thereby forming the biocidal non-woven matrix of any one of claims 1 to 5; (iii) providing an additional layer comprising spun-bond, or spunlace polymeric fibers and binding said additional layer with said biocidal non-woven matrix, thereby obtaining the multi-layered article.
  11. The process of claim 10, wherein the applying is by electro-spraying or airbrush spraying; and wherein the step (i) and the step (ii) are performed simultaneously or subsequently.
  12. The process of claim 10 or 11, wherein said binding comprises applying pressure and optionally exposing to a temperature sufficient for binding of additional layer with said biocidal non-woven matrix.
  13. The process of any one of claims 10 to 12, wherein said polymeric fibers are microfibers comprising a polymer selected from the group consisting of: a polyolefin, a polyester, and a polyamide, optionally wherein said polymer is selected form polyethylene, polypropylene, and polyethylene terephthalate, including any combination or a copolymer thereof.

Description

FIELD OF INVENTION The present invention is directed to, inter alia, non-woven fibrous compositions comprising nanofibers for use as biocidal (e.g. anti-viral) filters. BACKGROUND OF THE INVENTION SARS-CoV-2 is the virus that causes COVID-19, a type of coronavirus. A subgroup of Coronaviruses is a group of viruses that cause respiratory tract infections in humans. They are enveloped viruses with a positive-sense single-stranded RNA genome. There are yet to be vaccines or antiviral drugs to prevent or treat human coronavirus infections. COVID-19 has become a major public health issue with the 2019-2020 global outbreak as it is a novel coronavirus with efficient human-to-human transmission. Those infected may be either asymptomatic or develop symptoms, including fever, cough, and shortness of breath. Cases can progress to pneumonia, multi-organ failure, and death in the most vulnerable. An airborne viral infection is commonly caused by inhalation of droplets of moisture containing virus particles. Larger virus-containing droplets are deposited in the nose, while smaller droplets or nanoparticles find their way into the human airways or alveoli. Viruses, such as from the coronavirus family, are spread by droplets produced by coughing and sneezing with the sizes around 100-500 nm although other routes of infection may also be involved, such as facial contamination (Donnelly et al. Lancet, 361, 1761-1777, (2003)). From a filtration point of view, nano-scaled viruses and particles can, therefore, theoretically penetrate through the gaps of normal facial masks. Facial masks using traditional filtration fabric materials are therefore inadequate for stopping nano-scaled viruses. The gaps among fibers on the facial mask are, on average, 10 to 30 µm (10,000-30,000 nm). Masks with smaller fiber gaps may result in breathing difficulty. D1 (Elise des Ligneris et al. "Mixed Matrix Poly(Vinyl Alcohol)-Copper Nanofibrous Anti-Microbial Air-Microfilters", MEMBRANES, vol. 9, no. 87, pages 1-14) teaches composite electrospun nanofiber webs containing PVA crosslinked with copper acetate in a polymer to metal ratio of 60:40 wt %. D2 (JP 2008188082) teaches a water-repellent non-woven microfiber fabric having a covering covering a nostril and a mounting member disposed on the covering, the covering including an inorganic porous material and having an average fiber diameter of 1 to 100 µm. Other nano-scaled airborne viruses and particles as smoke and superfine dust can enter into the human lungs and then into the blood system through respiratory membranes. The health effect is related mainly to the sub-micron sized fraction of the particles (i.e., an aerodynamic diameter, dp, less than 1 µm). The global concern about a virus epidemic is now well-identified problems in the modern world, but solutions to help prevent the spread of viral disease have lacked so far. SUMMARY OF THE INVENTION The present invention provides, in some embodiments, compositions, and kits comprising a non-woven matrix for use as anti-microbial filters. The present invention further provides methods of reduction and/or prevention of virus transmission and methods of preparation of said compositions. According to one aspect, there is provided a biocidal non-woven matrix comprising an electrospun nanofiber comprising at least one polymer selected from a cationic polymer, a non-ionic polymer and an anionic polymer or a combination thereof, wherein a diameter of the electrospun nanofiber is between 50 to 1500 nanometers; wherein an outer/ free surface of said matrix is characterized by a water contact angle of less than 90°, the matrix comprises a plurality of pores and is characterized by a porosity suitable for capturing a microbe in a range between 50 and 400 nm; wherein the porosity is at least 80%, and the plurality of pores is characterized by a median pore size in a range between 60 and 800 nanometers; wherein the porosity allows for air permeability, k between 10-7 [m2] and 10-5 [m2] for flow rate of 8 L/min; and wherein said matrix further comprises between 0.1 and 40% of a biocidal agent by weight of the matrix. According to some embodiments, the biocidal non-woven matrix has a thickness, L, wherein said porosity allows for air permeability, k, between 10-7 [m2] and 10-5 [m2] for flow rate of 8 L/min. According to some embodiments, a diameter of said nanofiber is between 50 to 1500 nanometers. According to some embodiments, the biocidal non-woven matrix further comprises a pH reducing agent. According to some embodiments, the pH reducing agent lowers the pH to less than 5 at a location when in contact with a liquid droplet. According to some embodiments, the at least one polymer is selected from the group consisting of a cationic polymer, a non-ionic polymer, and an anionic polymer or a combination thereof. According to some embodiments, the electrospun nanofiber comprises: (i) said cationic polymer, or (ii) said non-ionic polymer and at least one of sa