Self-Disinfecting Face Shield

Abstract

An article with self-disinfecting and anti-fog properties. In embodiments, the article is a face shield having a transparent substrate configured to extend facing at least a portion of a face of a wearer, and has a first surface adapted to be disposed facing the face of the wearer and second surface disposed opposite to the first surface. The face panel is protected by a sulfonated polymeric layer on the second surface, for killing at least 95% microbes within 30 minutes of contact. The sulfonated polymeric is sufficiently or selectively sulfonated to contain from 10-100 mol % sulfonic acid or sulfonate salt functional groups based on the number of monomer units, for killing at least 99% of microbes within 5 minutes of coming into contact with the face panel. The sulfonated polymeric layer has a T fog of >15 minutes.

1 . A face shield comprising:
 a transparent face panel configured to extend facing at least a portion of a face of a wearer, the transparent face panel comprising:
 a substrate having a first surface adapted to be disposed facing the face of the wearer and second surface disposed opposite to the first surface, and 
 at least one of first surface and the second surface is protected by a sulfonated polymeric layer for killing at least 90% microbes within 120 minutes of contact with the transparent face panel; and
 wherein the sulfonated polymeric layer consists essentially of a sulfonated polymer, the sulfonated polymer from the group of perfluorosulfonic acid polymers, polystyrene sulfonates, sulfonated block copolymers, sulfonated polyolefins, sulfonated polyimides, sulfonated polyamides, sulfonated polyesters, sulfonated polysulfones, sulfonated polyketones, sulfonated poly(arylene ether), and mixtures thereof, the sulfonated polymer has a degree of sulfonation of >10%; 
 wherein the sulfonated polymeric layer has a thickness of at least >1 μm. 
 
   
     
     
         2 . The face shield of  claim 1 , wherein the sulfonated polymer has an ionic exchange capacity (IEC) of >0.5 meq/g. 
     
     
         3 . The face shield of  claim 1 , wherein the sulfonated polymeric layer has a thickness of at least >5 μm to kill >95% of microbes within 120 minutes of contact after six months of protection. 
     
     
         4 . The face shield of  claim 1 , wherein the sulfonated polymer has a degree of sulfonation of 10-100 mol %. 
     
     
         5 . The face shield of  claim 1 , wherein the sulfonated polymer is a selectively sulfonated negative-charged anionic block copolymer having a general configuration of: A-B-A, (A-B) n (A), (A-B-A) n , (A-B-A) n X, (A-B) n X, A-D-B, A-B-D, A-D-B-D-A, A-B-D-B-A, (A-D-B) n A, (A-B-D) n A (A-D-B) n X, (A-B-D) n X or mixtures thereof, wherein
 n is an integer from 0 to 30,   X is a coupling agent residue,   each A and D block is a polymer block resistant to sulfonation,   each B block is susceptible to sulfonation,   the A block is selected from polymerized (i) para-substituted styrene monomers, (ii) ethylene, (iii) alpha olefins of 3 to 18 carbon atoms; (iv) 1,3-cyclodiene monomers, (v) monomers of conjugated dienes having a vinyl content less than 35 mol percent prior to hydrogenation, (vi) acrylic esters, (vii) methacrylic esters, and (viii) mixtures thereof;   the B block is a vinyl aromatic monomer, and   the D block is a hydrogenated polymer or copolymer of a conjugated diene selected from isoprene, 1,3-butadiene and mixtures thereof; and   wherein the block B is selectively sulfonated to contain from 10-100 mol % sulfonic acid or sulfonate salt functional groups based on the number of monomer units, for the coating material to kill at least 99% of microbes within 30 minutes of contact.   
     
     
         6 . The face shield of  claim 1 , wherein the sulfonated polymeric layer has a surface pH of <3.0. 
     
     
         7 . The face shield of  claim 1 , wherein the sulfonated polymer is neutralized with at least a salt selected from ammonium, phosphonium, pyridinium, and sulfonium salts. 
     
     
         8 . The face shield of  claim 1 , wherein the sulfonated polymeric layer is applied onto one of the first surface and the second surface by dip coating, spray coating, dispersion coating, solvent casting, or adhesively attached as a peel-and-stick film. 
     
     
         9 . The face shield of  claim 1 , further comprising an attachment structure coupled to the face panel and configured to secure the face panel in front of the face of the wearer. 
     
     
         10 . The face shield of  claim 9 , wherein the attachment structure is an elastic band attached to a first and second side edges of the face panel. 
     
     
         11 . The face shield of  claim 10 , wherein the attachment structure includes
 a first strap attached to a first side edge of the face panel,   a second strap attached to a second side edge of the face panel, and   a coupler having a first member attached to the first strap and a second member attached to the second strap and adapted to removably engage with the first member to facilitate the engagement of the attachment structure with the wearer's head.   
     
     
         12 . The face shield of  claim 1 , wherein the transparent face panel is removable. 
     
     
         13 . The face shield of  claim 9 , wherein the attachment structure comprises any of: a cap adapted to be worn over the wearer's head with the face panel adapted to be removably engaged with the cap; an eyeglass frame removably engaged with the face panel; a hook-and-loop fastener assembly; and a protective garment to be worn by the wearer. 
     
     
         14 . The face shield of  claim 1 , wherein the substrate forming the face panel comprises a material selected from the group of polyesters, polycarbonates, allyl diglycolcarbonates, polyacrylates, polystyrenes, cellulose acetate butyrate, glass, and combinations thereof, and wherein the substrate forming the face panel has a thickness ranging from 0.001 to 2 mm. 
     
     
         15 . The face shield of  claim 1 , wherein the first surface facing the face of the wearer is protected by a sulfonated polymeric layer having a T fog  of >15 minutes. 
     
     
         16 . An article comprising a substrate and a coating layer is provided on at least one surface of the substrate;
 wherein the coating layer comprises a sulfonated styrenic block copolymer obtained by sulfonation of a styrenic block copolymer;   wherein the styrenic block copolymer comprises a polymer block A selected from polymerized (i) para-substituted styrene monomers, (ii) ethylene, (iii) alpha olefins of 3 to 18 carbon atoms, (iv) 1,3-cyclodiene monomers, (v) monomers of conjugated dienes having a vinyl content less than 35 mole % prior to hydrogenation, (vi) acrylic esters, (vii) methacrylic esters, and (viii) mixtures thereof;
 a polymer block B of a vinyl aromatic monomer; and 
 a polymer block D of a conjugated diene monomer; 
   wherein at least one polymer block A, B, or D is sulfonated to obtain a degree of sulfonation of the sulfonated styrenic block copolymer of greater than 10 mole %, based on total weight of the sulfonated styrenic block copolymer;   wherein the article with the antifog coating layer has:
 a T fog  of greater than 8 seconds, measured at 40° C. steam test according to ANSI/ISEA Z87.1; and 
 a yellowness index (ΔYI) of less than 4, according to ASTM E313; and 
   wherein the coating layer has a thickness of at least >1 μm to kill at least 90% of microbes upon within 120 minutes of contact with the coating layer.   
     
     
         17 . The article of  claim 16 , wherein the coating layer is prepared by mixing the sulfonated styrenic block copolymer and optional additives in an organic solvent for a total solid content of sulfonated styrenic block copolymer in the organic solvent in the range of 5 to 30 wt. %, based on total weight of the organic solvent. 
     
     
         18 . The article of  claim 17 , wherein the organic solvent is selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, s-butanol, t-butanol, acetone, cyclohexanone, benzene, toluene, xylene, n-hexane, cyclohexane, n-heptane, n-octane, n-decane, and mixtures thereof. 
     
     
         19 . The article of  claim 16 , wherein the coating layer has a thickness of 1 to 100 μm. 
     
     
         20 . The article of  claim 16 , wherein the substrate is at least one selected from the group consisting of polycarbonate, acrylic, styrene, polyvinylchloride, polybisallyl carbonate, polyethylene terephthalate, bi-axially oriented polypropylene (BOPP), polyethylene naphthenate, triacetate, and cellulose acetate; wherein the substrate has a thickness of 10 μm to 10 mm.