# US 5,706,804 A · Liquid resistant face mask having surface energy reducing agent on an intermediate layer therein > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,706,804 A - Document ID: US5706804A - Status: Granted - Kind: A - Application number: 08/791,918 - Filed: 1997-01-31 - Granted: 1998-01-13 - Earliest claimed: 1996-10-01 - Assignees: Minnesota Mining and Manufacturing Company - Inventors: Nicholas R. Baumann; John M. Brandner; John A. Temperante; Shannon Dowdell; Michael D. Romano; Scott J. Tuman; Matthew T. Scholz - Web page: https://patentgrep.com/patent/US5706804A ## CPC - A41D 13/1115: {with a horizontal pleated pocket} - A41D: OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES ## Abstract A face mask including a face-contacting layer, an outer cover layer, a polymeric microfiber mat disposed between the face-contacting layer and the outer cover layer, and a non-woven fibrous mat disposed between the face-contacting layer and the outer cover layer. The non-woven fibrous mat includes polymeric fibers and a surface energy reducing agent. The face-contacting layer, the cover layer, the polymeric microfiber mat, and the non-woven fibrous mat cooperate with each other to allow gas to pass through the mask while inhibiting the passage of liquid through the mask. ## Claims ### Claim 1 A face mask comprising: a face-contacting layer; an outer cover layer; a polymeric microfiber mat disposed between said face-contacting layer and said outer cover layer; and a non-woven fibrous mat disposed between said face-contacting layer and said outer cover layer, said non-woven fibrous mat comprising polymeric fibers and a surface energy reducing agent, said face-contacting layer, said cover layer, said polymeric microfiber mat, and said non-woven fibrous mat cooperating with each other to allow gas to pass through said mask while inhibiting the passage of liquid through said mask. ### Claim 2 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat is disposed between said polymeric microfiber mat and said cover layer. ### Claim 3 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat is disposed between said face-contacting layer and said polymeric microfiber mat. ### Claim 4 (depends on 1) The face mask of claim 1, wherein said surface energy reducing agent comprises a fluorochemical, a wax, a silicone, or a combination thereof. ### Claim 5 (depends on 1) The face mask of claim 1, wherein said surface energy reducing agent comprises a fluorochemical. ### Claim 6 (depends on 1) The face mask of claim 1, wherein said surface energy reducing agent comprises a fluorochemical oxazolidinone, a fluorochemical piperazine, a fluoroaliphatic radical-containing compound, or a combination thereof. ### Claim 7 (depends on 1) The face mask of claim 1, wherein said surface energy reducing agent comprises a fluorochemical oxazolidinone. ### Claim 8 (depends on 1) The face mask of claim 1, wherein the amount of said surface energy reducing agent is no greater than about 4.0% by weight based upon the total weight of said mat. ### Claim 9 (depends on 1) The face mask of claim 1, wherein the amount of said surface energy reducing agent is no greater than about 2.0% by weight based upon the total weight of said mat. ### Claim 10 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat comprises a surface energy reducing agent incorporated into said fibers. ### Claim 11 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat comprises a surface energy reducing agent on the surface of said fibers. ### Claim 12 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat comprises polymeric microfibers, staple fibers, continuous filament fibers, or a combination thereof. ### Claim 13 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat comprises polymeric microfibers. ### Claim 14 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat has an effective fiber diameter no greater than about 20 micrometers. ### Claim 15 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat has an effective fiber diameter between about 1 and 10 micrometers. ### Claim 16 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat has a solidity no greater than about 10%. ### Claim 17 (depends on 1) The face mask of claim 1, wherein the pressure drop across said non-woven fibrous mat ranges from between about 0.1 to about 2.70 mm H.sub.2 O at a flow rate of 32 lpm and a face velocity of 3.82 cm/s. ### Claim 18 (depends on 1) The face mask of claim 1, wherein the pressure drop across said non-woven fibrous mat ranges from between about 0.1 to about 2.50 mm H.sub.2 O at a flow rate of 32 lpm and a face velocity of 3.82 cm/s. ### Claim 19 (depends on 1) The face mask of claim 1, wherein the pressure drop across said non-woven fibrous mat ranges from between about 0.1 to about 1.50 mm H.sub.2 O at a flow rate of 32 lpm and a face velocity of 3.82 cm/s. ### Claim 20 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat has a basis weight ranging between about 10 and about 50 g/m.sup.2. ### Claim 21 (depends on 1) The face mask of claim 1, wherein the area of said non-woven fibrous mat, measured by multiplying the length of said mat by the width of said mat prior to pleating, is at least about 2% greater than the corresponding area of any one of said face-contacting layer, said polymeric microfiber mat and said outer cover layer. ### Claim 22 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat comprises an electret. ### Claim 23 (depends on 1) The face mask of claim 1, wherein said polymeric microfiber mat comprises a fluorochemical incorporated into said microfibers. ### Claim 24 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat comprises polyolefin, polyamide, polyester, or polyvinylchloride microfibers, or a combination thereof. ### Claim 25 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat comprises polyethylene, polypropylene, polybutylene, or poly-4-methylpentene microfibers, or a combination thereof. ### Claim 26 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat comprises a blend of polypropylene and polybutylene microfibers. ### Claim 27 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat comprises a blend of up to about 50% by weight polypropylene microfibers and up to about 50% by weight polybutylene microfibers. ### Claim 28 (depends on 1) The face mask of claim 1, wherein said non-woven fibrous mat comprises a blend of up to about 50% by weight polypropylene microfibers, up to about 50% by weight polybutylene microfibers, and about 0.5% by weight of a surface energy reducing agent comprising a fluorochemical. ### Claim 29 (depends on 1) The face mask of claim 1, wherein the basis weight of said mask is no greater than about 95 g/m.sup.2. ### Claim 30 (depends on 1) The face mask of claim 1, wherein the pressure drop across said mask is no greater than about 2.70 mm H.sub.2 O at a flow rate of 32 lpm and a face velocity of 3.82 cm/s. ### Claim 31 (depends on 1) The face mask of claim 1, further comprising an air impervious element secured to said mask to inhibit the flow of air to the eyes of the wearer of said mask. ### Claim 32 (depends on 1) The face mask of claim 1, further comprising a shield affixed to said mask to extend over and protect the eyes of the wearer of said mask. ### Claim 33 (depends on 1) The face mask of claim 1, further comprising a pair of flaps affixed to opposite sides of said mask to protect the face of the wearer from liquid. ### Claim 34 (depends on 1) The face mask of claim 1, wherein said mask assumes an off-the-face configuration. ### Claim 35 A face mask comprising: a face-contacting layer; an outer cover layer; a first mat comprising polymeric microfibers disposed between said face-contacting layer and said outer cover layer; and a second mat comprising polymeric microfibers disposed between said face-contacting layer and said outer cover layer, said second mat further comprising a fluorochemical incorporated into said microfibers, said face-contacting layer, said cover layer, and said first and second mats cooperating with each other to allow gas to pass through said mask while inhibiting the passage of liquid through said mask.