Abstract: An electret article that includes a polymeric material that has electric charge imparted thereto, that has a CF3:CF2 ratio of at least 0.15 and that has a fluorosaturation ratio greater than about 200. The electret article may be in the form of a porous web of polymeric fibers suitable for use as a filter. The inventive electret article is resistant to charge degradation upon exposure to high temperatures for prolonged time periods.

Abstract: A method for imparting an electrostatic charge to a nonwoven fibrous web 20. The fibrous web 20 is contacted with a liquid solution that includes water and a non-aqueous water soluble component, followed by drying 31. The resulting dried product is an electret article 43 that could be used as an air filter in, for example, a respirator 50.

Abstract: A method of making electret fibers, which method comprises: extruding a polymeric material to create fibers; and imparting an electric charge to the fibers; wherein the resulting fibers have a level of extractable hydrocarbon material that is less than 3.0 weight percent, based on the weight of the fibers.

Abstract: A method for imparting an electrostatic charge to a nonwoven fibrous web 20. The fibrous web 20 is contacted with a liquid solution that includes water and a non-aqueous water soluble component, followed by drying 31. The resulting dried product is an electret article 43 that could be used as an air filter in, for example, a respirator 50.

Abstract: A method of charging fibrous webs with nonaqueous polar liquids. A web 20 that contains nonconductive fibers is wetted with a nonaqueous polar liquid 14. The web 20 is then substantially dried 22 to provide a fibrous electret web. The fibrous electret web can be used as a filter in a filtration face mask 40 that is adapted to cover the nose and mouth of the wearer. The present method has the advantage over known charging methods in that the nonaqueous liquid requires less energy for drying than is required for aqueous liquids. Additionally, many filter webs can be directly wetted with nonaqueous liquids, which cannot be easily wetted with aqueous liquids.

Abstract: A method for imparting an electrostatic charge to a nonwoven fibrous web 20. The fibrous web 20 is wetted with a wetting liquid 24, followed by being saturated with an aqueous polar liquid 30 and drying 31. The resulting dried product is an electret article 43 that could be used as an air filter in, for example, a respirator 50.

Abstract: Electret fibers that contain a polymeric material and a fluorochemical additive. The electret fibers have a low level of extractable hydrocarbon material. Electret filters that have low extractable hydrocarbon levels exhibit improved filtration performance.

Abstract: A method of making electret fibers, which method comprises the steps of: blending a polymeric material with a fluorochemical additive compound; extruding the blend at a temperature maintained below 290° C. to form extruded fibers; and annealing and charging the extruded fibers; wherein the polymeric material and extrusion conditions are selected such that the resulting fibers have a level of extractable hydrocarbon material that is less than about 3.0 weight percent based on the weight of the fibers.

Abstract: A compound comprising wherein R2 is an alkyl group which may be straight chain or branched and n is a number of from 2 to 40.

Abstract: A method of removing particulate solid or liquid aerosol from a gas, which method comprises the step of: passing a particulate solid or liquid aerosol containing gas through an electret filter that comprises a polymer and a performance enhancing additive, wherein the electret filter has a thermally stimulated discharge current (TSDC) spectrum exhibiting a peak having a width at half height of less than about 30° C., as measured by TSDC test procedure 3.

Abstract: Novel electret articles containing a polymer and a performance-enhancing additive can be identified by their thermally stimulated conductivity characteristics or their filtration properties. Electret articles such as nonwoven filter webs and respirators exhibit superior oily mist loading performance, low penetration and a small pressure drop.

Abstract: A method of predicting the performance of electret filter web involves measuring the level of extractable hydrocarbon material in the web. Electret filters that have low extractable hydrocarbon levels exhibit improved filtration performance.

Abstract: The thermally stimulated discharge current of an electret article can be used to identify electret articles that exhibit superior filtration properties. Electret filters that exhibit superior properties not achieved in similarly constructed filters contain fibers that are made from a blend of a polymer and a performance-enhancing additive. The electret filters exhibit an initial detectable DOP penetration of less than 5% and an average Min@Chl of greater than 200 mg DOP as measured by DOP Filter Web Loading Test Procedure 1. These new electrets are particularly useful in a respirator.

Abstract: Electret fibers that contain a polymeric material and a fluorochemical additive. The electret fibers have a low level of extractable hydrocarbon material. Electret filters that have low extractable hydrocarbon levels exhibit improved filtration performance.

Abstract: An electret article can be made by quenching a molten blend containing a polymer and a performance-enhancing additive. The resulting low crystallinity material can be annealed and charged to produce a material for making electret filters having superior oily mist loading performance properties.

Abstract: A compound comprising ##STR1## wherein R.sub.f is a perfluorinated moiety which may contain one or more catenary ether oxygen atoms, Q is a linking group selected from alkylene groups having 1 or 2 carbon atoms, sulfonamido groups or combinations thereof, and R.sup.1 is a perfluoroalkyl group.

Abstract: Electret filter media comprising a fibrous web of a blend of a thermoplastic resin and at least one compound or oligomer that enhances the web's electret properties.

Abstract: Fibrous webs comprising a blend of a thermoplastic resin and at least one compound or oligomer which is ##STR1## wherein R.sub.f is a perfluorinated moiety which may contain one or more catenary ether oxygen atoms, Q is a linking group selected from alkylene groups having 1 or 2 carbon atoms, sulfonamido groups or combinations thereof, R is an alkyl group, R.sup.1 is a perfluoroalkyl group, R.sup.2 is an alkyl group which may be straight chain or branched and n is a number of from 2 to 40.

Abstract: A composition comprising a blend of a thermoplastic resin and at least one compound or oligomer which is ##STR1## wherein R.sub.f is a perfluorinated moiety which may contain one or more catenary ether oxygen atoms, Q is a linking group selected from alkylene groups having 1 or 2 carbon atoms, sulfonamido groups or combinations thereof, R is an alkyl group, R.sup.1 is a perfluoroalkyl group, R.sup.2 is an alkyl group which may be straight chain or branched and n is a number of from 2 to 40.

Abstract: The present invention relates to a method of making a fibrous electret material which includes the steps of (1) forming a fibrous web of nonconductive thermoplastic fibers from a blend of nonconductive thermoplastic resin and an additive which is (a) a thermally stable organic compound or oligomer containing at least one perfluorinated moiety or (b) a thermally stable organic triazine compound or oligomer containing at least one nitrogen atom in addition to those in the triazine group or (c) a combination thereof; (2) impinging jets of water or a stream of water droplets onto the web at a pressure sufficient to provide the web with filtration enhancing electret charge; and (3) drying the web.