Patents by Inventor Daniel C. Duan

Daniel C. Duan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20240009606
    Abstract: Described herein is the use of a cyclotriphosphazene core substituted with at least three amino-cyclic carbon groups used as a charge-enhancing additive in a thermoplastic resin. Such compositions may be used in filtering applications.
    Type: Application
    Filed: November 29, 2021
    Publication date: January 11, 2024
    Inventors: Kelly A. Volp, Nathan E. Schultz, Daniel C. Duan, Seth M. Kirk, Fuming B. Li, John M. Sebastian
  • Publication number: 20230390678
    Abstract: Described herein is a thermoplastic core-sheath fiber. The thermoplastic core-sheath fiber comprises a core having a coextensive sheath layer disposed thereon, wherein the core comprises a first polymeric resin and an electrostatic charge enhancing additive, and the sheath layer comprising a second polymeric resin, with the proviso that if the second polymeric resin comprises poly(4-methyl-1-pentene), then the second polymeric resin does not comprise 100 wt % of poly(4-methyl-1-pentene). These thermoplastic core-sheath fibers can be used in filtering applications.
    Type: Application
    Filed: November 1, 2021
    Publication date: December 7, 2023
    Inventors: Nathan E. Schultz, Zackary J. Becker, Daniel C. Duan, Himanshu Jasuja, Seth M. Kirk, Fuming B. Li, John M. Sebastian, Georgiy Teverovskiy
  • Publication number: 20230233968
    Abstract: A pleated multilayer air filter assembly including a primary filtration layer and a prefilter layer that are bonded to each other and are co-pleated with each other. The primary filtration layer includes meltblown electret fibers. The prefilter layer includes meltspun, spunbonded electret fibers that comprise a radially outer surface comprising polymethylpentene. The ratio of Effective Fiber Diameter of the fibers of the primary filtration layer to Effective Fiber Diameter of the fibers of the primary filtration layer is at least 1.5.
    Type: Application
    Filed: June 30, 2021
    Publication date: July 27, 2023
    Inventors: HIMANSHU JASUJA, Nathan E. Schultz, Seth M. Kirk, Bryan L. Gerhardt, Daniel C. Duan, Michael R. Berrigan
  • Publication number: 20220372666
    Abstract: A thermoplastic core-sheath fiber comprises: a polymer fiber core having a coextensive sheath layer disposed thereon, and an electrostatic charge enhancing additive. The sheath layer may comprise poly(4-methyl-1-pentene) and the fiber core and the sheath layer have different compositions. At least one of the fiber core or the sheath layer comprises an electret charge. A nonwoven fibrous web comprising the core-sheath fibers and a respirator including the nonwoven fibrous web are also disclosed.
    Type: Application
    Filed: June 24, 2020
    Publication date: November 24, 2022
    Inventors: Nathan E. Schultz, Daniel C. Duan, Seth M. Kirk, Michael R. Berrigan, Zackary J. Becker, Fuming B. Li, John M. Sebastian
  • Publication number: 20220323890
    Abstract: A filter assembly comprises an air filter medium and a prefilter medium. The prefilter medium comprises a second nonwoven fibrous web comprising poly(4-methylpentene) and an electrostatic charging additive and has a second electret charge. The filter assembly is configured such that air passing through the prefilter is directed through the air filter medium. A respirator includes the filter assembly. A prefilter assembly comprises a third nonwoven fibrous web retained by a prefilter frame. The third nonwoven fibrous web comprises: core-sheath fiber comprising a fiber core having a poly(4-methylpentene) sheath layer disposed thereon; and an electrostatic charging additive, wherein the electrostatic charging additive is contained in at least one of the fiber core or the sheath layer. The third nonwoven fibrous web has a third electret charge.
    Type: Application
    Filed: June 12, 2020
    Publication date: October 13, 2022
    Inventors: Nathan E. Schultz, Daniel C. Duan, Seth M. Kirk, Michael R. Berrigan, Zackary J. Becker, Fuming B. Li, John M. Sebastian
  • Patent number: 9861580
    Abstract: A method of making active pharmaceutical ingredient particles with surface-modified nanoparticles deposited on the particles' surfaces, the method comprising: providing a plurality of media particles having surfaces with the surface-modified nanoparticles deposited on the surfaces; mixing the plurality of media particles with the active ingredient particles, both of which are in dry form, to provide active ingredient particles having surfaces with the surface-modified nanoparticles deposited on the surfaces; and separating the plurality of media particles from the active ingredient particles having surfaces with the surface-modified nanoparticles deposited on the surfaces is disclosed.
    Type: Grant
    Filed: June 22, 2009
    Date of Patent: January 9, 2018
    Assignee: 3M Innovative Properties Company
    Inventors: Michael W. Mueting, Daniel C. Duan, Stephen W. Stein
  • Patent number: 8554317
    Abstract: A method of treating a patient with a microneedle array having an active agent disposed on at least a portion of one or more of the microneedles, wherein the array with active agent is characterized by a first optical response when probed with a selected incident light spectrum. The array with active agent is applied to a skin surface, optionally allowed to remain on the skin surface for a specified time, and removed. The used array is probed with the selected incident light spectrum, a second optical response is sensed, and the difference between the first optical response and the second optical response is determined and compared to a predetermined threshold value.
    Type: Grant
    Filed: November 16, 2006
    Date of Patent: October 8, 2013
    Assignee: 3M Innovative Properties Company
    Inventor: Daniel C. Duan
  • Publication number: 20130253446
    Abstract: Thermotropic liquid crystalline polymer microneedles (100) are described.
    Type: Application
    Filed: May 26, 2011
    Publication date: September 26, 2013
    Applicant: 3M INNOVATIVE PROPERTIES COMPANY
    Inventors: Daniel C. Duan, Stanley Rendon
  • Publication number: 20110104362
    Abstract: A method of making active pharmaceutical ingredient particles with surface-modified nanoparticles deposited on the particles' surfaces, the method comprising: providing a plurality of media particles having surfaces with the surface-modified nanoparticles deposited on the surfaces; mixing the plurality of media particles with the active ingredient particles, both of which are in dry form, to provide active ingredient particles having surfaces with the surface-modified nanoparticles deposited on the surfaces; and separating the plurality of media particles from the active ingredient particles having surfaces with the surface-modified nanoparticles deposited on the surfaces is disclosed.
    Type: Application
    Filed: June 22, 2009
    Publication date: May 5, 2011
    Inventors: Michael W. Mueting, Daniel C. Duan, Stephen W. Stein
  • Patent number: 7846488
    Abstract: A method of coating a microneedle array comprising: providing a microneedle array having a substrate and at least one needle; providing a removable masking layer on the microneedle array such that the substrate is at least partially covered by the masking layer and the at least one needle remains at least partially exposed; and applying a coating material to at least a portion of the exposed portion of the microneedle array.
    Type: Grant
    Filed: November 18, 2005
    Date of Patent: December 7, 2010
    Assignee: 3M Innovative Properties Company
    Inventors: Peter R. Johnson, Marla R. Emery, James T. Wolter, Jennifer E. Raeder-Devens, Daniel C. Duan, Moses M. David, Hye-Ok Choi
  • Patent number: 7718162
    Abstract: The invention comprises a medicinal aerosol composition comprising a propellant, an excipient comprising a functionalized polyethyleneglycol, and a drug. The invention also comprises particulate medicinal compositions comprising particles with a mean mass aerodynamic diameter of less than about 10 microns that incorporate an excipient comprising a functionalized polyethyleneglycol.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: May 18, 2010
    Assignee: 3M Innovative Properties Company
    Inventors: James S. Stefely, Daniel C. Duan
  • Patent number: 7687054
    Abstract: Methods, compounds, and medicinal formulations utilizing biocompatible polymers for delivery of a drug, particularly for solubilizing, stabilizing and/or providing sustained release of drug from topical, implantable, and inhalation systems. Many of the methods, compounds, and medicinal formulations are particularly suitable for oral and/or nasal inhalation and use polymers of the formula —[X—R1—C(O)]— wherein each R1 is an independently selected organic group that links the —X— group to the carbonyl group, and each X is independently oxygen, sulfur, or catenary nitrogen.
    Type: Grant
    Filed: February 18, 2002
    Date of Patent: March 30, 2010
    Assignee: 3M Innovative Properties Company
    Inventors: James S. Stefely, David W. Schultz, Chester L. Leach, Daniel C. Duan
  • Publication number: 20080287858
    Abstract: A method of treating a patient with a microneedle array having an active agent disposed on at least a portion of one or more of the microneedles, wherein the array with active agent is characterized by a first optical response when probed with a selected incident light spectrum. The array with active agent is applied to a skin surface, optionally allowed to remain on the skin surface for a specified time, and removed. The used array is probed with the selected incident light spectrum, a second optical response is sensed, and the difference between the first optical response and the second optical response is determined and compared to a predetermined threshold value.
    Type: Application
    Filed: November 16, 2006
    Publication date: November 20, 2008
    Inventor: Daniel C. Duan
  • Publication number: 20080262416
    Abstract: A microneedle array having a substrate and a plurality of microneedles extending out from the substrate with a multi-phase matrix coating on at least a portion of the microneedle surface of the microneedle array. The multi-phase matrix coating comprises an active substance and has a first solid phase and a liquid phase. The first solid phase comprises a water-soluble polymer. Also, a method of providing an active substance- containing matrix coating on a microneedle array in which a water-soluble polymer is applied to the microneedle surface of the array to form a dried coating of water-soluble polymer. A coating solution comprising an active substance, a liquid capable of phase separating from the water-soluble polymer, and a carrier fluid is prepared and applied to the dried coating of water-soluble polymer. At least a portion of the carrier fluid is removed from the array.
    Type: Application
    Filed: November 17, 2006
    Publication date: October 23, 2008
    Inventors: Daniel C. Duan, Peter R. Johnson
  • Publication number: 20080102192
    Abstract: A method of coating a microneedle array comprising: providing a microneedle array having a substrate and at least one needle; providing a removable masking layer on the microneedle array such that the substrate is at least partially covered by the masking layer and the at least one needle remains at least partially exposed; and applying a coating material to at least a portion of the exposed portion of the microneedle array.
    Type: Application
    Filed: November 18, 2005
    Publication date: May 1, 2008
    Inventors: Peter R. Johnson, Maria R. Emery, James T. Wolter, Jennifer E. Raeder-Devens, Daniel c. Duan, Moses M. David, Hye-Ok Choi
  • Patent number: 7186402
    Abstract: The invention comprises a medicinal aerosol composition comprising a propellant, an excipient comprising an acid or amine end-group and at least one and no more than two amide and/or ester functional groups, and a drug. The invention also comprises particulate medicinal compositions comprising particles with a mean mass aerodynamic diameter of less than about 10 microns that incorporate an excipient containing an acid or amine end-group and at least one and no more than two amide and/or ester functional groups.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: March 6, 2007
    Assignee: 3M Innovative Properties Company
    Inventors: Daniel C. Duan, Robert A. Scherrer, James S. Stefely
  • Patent number: 7097853
    Abstract: A transdermal drug delivery device involving a macromonomer-containing acrylate or methacrylate copolymer, a softener, and a drug. Also a pressure sensitive skin adhesive involving a macromonomer containing acrylate or methacrylate copolymer and a softener.
    Type: Grant
    Filed: November 12, 1997
    Date of Patent: August 29, 2006
    Assignee: 3M Innovative Properties Company
    Inventors: James E. Garbe, Daniel C. Duan, Cheryl L. Moore, Jamieson C. Keister, Chan U. Ko
  • Patent number: 6902740
    Abstract: The present invention relates to a pressure sensitive adhesive composition comprising a copolymer comprising pyrrolidonoethyl acrylate or pyrrolidonoethyl methacrylate. This composition may be used as part of a transdermal drug delivery device.
    Type: Grant
    Filed: July 9, 2001
    Date of Patent: June 7, 2005
    Assignee: 3M Innovative Properties Company
    Inventors: Mark S. Schaberg, Daniel C. Duan, Kaveh Pournoor
  • Publication number: 20030152521
    Abstract: The invention comprises a medicinal aerosol composition comprising a propellant, an excipient comprising a functionalized polyethyleneglycol, and a drug. The invention also comprises particulate medicinal compositions comprising particles with a mean mass aerodynamic diameter of less than about 10 microns that incorporate an excipient comprising a functionalized polyethyleneglycol.
    Type: Application
    Filed: December 20, 2002
    Publication date: August 14, 2003
    Applicant: 3M Innovative Properties Company
    Inventors: James S. Stefely, Daniel C. Duan
  • Publication number: 20030138381
    Abstract: The invention comprises a medicinal aerosol composition comprising a propellant, an excipient comprising an acid or amine end-group and at least one and no more than two amide and/or ester functional groups, and a drug. The invention also comprises particulate medicinal compositions comprising particles with a mean mass aerodynamic diameter of less than about 10 microns that incorporate an excipient containing an acid or amine end-group and at least one and no more than two amide and/or ester functional groups.
    Type: Application
    Filed: December 20, 2002
    Publication date: July 24, 2003
    Applicant: 3M Innovative Properties Company
    Inventors: Daniel C. Duan, Robert A. Scherrer, James S. Stefely