Patents by Inventor Ashok Sengupta

Ashok Sengupta 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).

  • Patent number: 7459167
    Abstract: Polymeric compositions that include polyurethane polymers derived from a polyisocyanate compound and a polyactive hydrogen compound. The polyurethane compound is at least partially endcapped with a group including at least one antimicrobial quaternary ammonium compound. The polymeric composition of the present invention is capable of forming a self-supporting film. The polymeric compositions are suitable for coating substrates to effectively kill or prevent the growth of microorganisms such as bacteria, mold, mildew, algae fungi and the like. The polymeric compositions are particularly useful for protecting construction materials used in moist, outdoor environments to prevent discoloration or decay from microorganisms and for surfaces in health care facilities to mitigate the spread of pathogens.
    Type: Grant
    Filed: July 27, 2000
    Date of Patent: December 2, 2008
    Assignee: 3M Innovative Properties Company
    Inventors: Ashok Sengupta, Jeffrey L. Jacobs, Matthew T. Scholz, Kestutis J. Tautvydas
  • Patent number: 7290960
    Abstract: A liner is the product of reaction of (a) a hydrophilic prepolymer bearing isocyanate groups; and (b) a water-borne polymer dispersion, the polymer bearing groups that are reactive to isocyanate groups; wherein the dispersion has a sufficiently high solids content, and the polymer has a sufficiently high modulus and glass transition or crystalline melting temperature, that the product of reaction exhibits a 24-hour Tensile Strength of at least about 2.5 MPa.
    Type: Grant
    Filed: December 23, 2005
    Date of Patent: November 6, 2007
    Assignee: 3M Innovative Properties Company
    Inventors: Ashok Sengupta, Jiangdong Tong
  • Publication number: 20060099034
    Abstract: A liner is the product of reaction of (a) a hydrophilic prepolymer bearing isocyanate groups; and (b) a water-borne polymer dispersion, the polymer bearing groups that are reactive to isocyanate groups; wherein the dispersion has a sufficiently high solids content, and the polymer has a sufficiently high modulus and glass transition or crystalline melting temperature, that the product of reaction exhibits a 24-hour Tensile Strength of at least about 2.5 MPa.
    Type: Application
    Filed: December 23, 2005
    Publication date: May 11, 2006
    Inventors: Ashok Sengupta, Jiangdong Tong
  • Patent number: 7011865
    Abstract: A liner is the product of reaction of (a) a hydrophilic prepolymer bearing isocyanate groups; and (b) a water-borne polymer dispersion, the polymer bearing groups that are reactive to isocyanate groups; wherein the dispersion has a sufficiently high solids content, and the polymer has a sufficiently high modulus and glass transition or crystalline melting temperature, that the product of reaction exhibits a 24-hour Tensile Strength of at least about 2.5 MPa.
    Type: Grant
    Filed: September 6, 2002
    Date of Patent: March 14, 2006
    Assignee: 3M Innovative Properties Company
    Inventors: Ashok Sengupta, Jiangdong Tong
  • Patent number: 6664414
    Abstract: The invention provides a process for reducing the amount of monomeric polyisocyanate in a composition comprising a polymer or oligomer bearing isocyanate groups, the method comprising reacting the composition with a quenching agent, the quenching agent comprising an arylalkyl alcohol and an alkoxysilane bearing a secondary amino group.
    Type: Grant
    Filed: September 11, 2001
    Date of Patent: December 16, 2003
    Assignee: 3M Innovative Properties Company
    Inventors: Jiangdong Tong, Ashok Sengupta
  • Publication number: 20030125472
    Abstract: A liner is the product of reaction of (a) a hydrophilic prepolymer bearing isocyanate groups; and (b) a water-borne polymer dispersion, the polymer bearing groups that are reactive to isocyanate groups; wherein the dispersion has a sufficiently high solids content, and the polymer has a sufficiently high modulus and glass transition or crystalline melting temperature, that the product of reaction exhibits a 24-hour Tensile Strength of at least about 2.5 MPa.
    Type: Application
    Filed: September 6, 2002
    Publication date: July 3, 2003
    Applicant: 3M Innovative Properties Company
    Inventors: Ashok Sengupta, Jiangdong Tong
  • Publication number: 20030092848
    Abstract: The invention provides a liner which is the product of reaction of a (a) hydrophilic prepolymer bearing isocyanate groups; and (b) a water-borne polyurethane dispersion, the polyurethane bearing groups that are reactive to isocyanate groups.
    Type: Application
    Filed: September 11, 2001
    Publication date: May 15, 2003
    Inventors: Ashok Sengupta, Jiangdong Tong
  • Publication number: 20030092932
    Abstract: The invention provides a process for reducing the amount of monomeric polyisocyanate in a composition comprising a polymer or oligomer bearing isocyanate groups, the method comprising reacting the composition with a quenching agent, the quenching agent comprising an arylalkyl alcohol and an alkoxysilane bearing a secondary amino group.
    Type: Application
    Filed: September 11, 2001
    Publication date: May 15, 2003
    Inventors: Jiangdong Tong, Ashok Sengupta
  • Patent number: 6432396
    Abstract: The present invention provides a method of limiting the presence of a microorganism by contacting the microorganism with polymer-bound metal-containing compositions. The compositions include metal-containing compounds that may be prepared by reacting or polymerizing metal-containing monomers. The microorganism may be present in a liquid that is contacted with the polymer-bound metal-containing composition. Alternatively, the microorganism may be present in a solid that is contacted with the polymer-bound metal-containing composition.
    Type: Grant
    Filed: July 6, 2000
    Date of Patent: August 13, 2002
    Assignee: 3M Innovative Properties Company
    Inventors: Kevin D. Landgrebe, David J. Hastings, Terrance P. Smith, Gregory D. Cuny, Ashok Sengupta, Chandrika D. Mudalige, Frank A. Brandys
  • Patent number: 6313335
    Abstract: Coatings are provided with very low surface energies provided by fluorine and/or silicone moieties. Aqueous dispersions of externally chain extended polyurethane compositions terminated by hydrolyzable and/or hydrolyzed silyl groups and containing dispersing or emulsifying groups, particularly carboxyl groups are provided. Also polyurethane dispersions which are substantially organic solvent free which cure to water and solvent resistant, tough, scratch resistant, preferably light stable polyurethane films are provided. Such films are useful as anti-fouling marine coatings. The compound RfR′fCFCOOCH2C(R)(CH2OH)2 is provided.
    Type: Grant
    Filed: November 25, 1997
    Date of Patent: November 6, 2001
    Assignee: 3M Innovative Properties
    Inventors: Gary P. Roberts, Lowell W. Holland, Richard G. Hansen, Ashok Sengupta, George G. I. Moore, Miguel A. Guerra
  • Patent number: 6248364
    Abstract: A process for encapsulating a partially water-miscible organic material within a polyurea or polyurethane shell is provided utilizing a water-soluble tertiary amine in the reaction dispersion. Microcapsules and methods of using microcapsules are also provided.
    Type: Grant
    Filed: April 7, 1997
    Date of Patent: June 19, 2001
    Assignee: 3M Innovative Properties Company
    Inventors: Ashok Sengupta, Kent E. Nielsen, Galina Barinshteyn, Kai Li
  • Patent number: 6080418
    Abstract: A composition comprising two suspensions: A) an aqueous suspension of microcapsules containing biologically active materials and B) an adhesive suspension of adhesive microspheres. The composition is useful for adhering microencapsulated biologically active material onto an intended substrate.
    Type: Grant
    Filed: April 7, 1997
    Date of Patent: June 27, 2000
    Assignee: 3M Innovative Properties Company
    Inventors: Ashok Sengupta, Kent E. Nielsen, Galina Barinshteyn, Kai Li, John P. Banovetz
  • Patent number: 6072019
    Abstract: The invention relates to novel water-soluble or water-dispersible polyurethane compounds and to compositions that contain the novel compounds and are useful, for instance, as low adhesion backsize for adhesive tapes. The invention also relates to processes for preparing the novel compounds, compositions and tapes.
    Type: Grant
    Filed: February 4, 1998
    Date of Patent: June 6, 2000
    Assignee: 3M Innovative Properties Company
    Inventor: Ashok Sengupta
  • Patent number: 6046295
    Abstract: This invention provides aqueous dispersions of externally chain extended polyurethane compositions terminated by hydrolyzable and/or hydrolyzed silyl groups and containing anionic solubilizing or emulsifying groups, particularly carboxyl groups. The invention also provides methods of making both anionically and cationically stabilized polyurethane dispersions. This invention further provides polyurethane dispersions which are substantially organic solvent free, (e.g. less than about 7 weight percent organic solvent) which cure to water and solvent resistant, tough, scratch resistant, preferably light stable (non-yellowing) polyurethane films. Such films are particularly useful as coatings for wood substrates, including wood floorings, furniture, and marine surfaces.
    Type: Grant
    Filed: August 30, 1996
    Date of Patent: April 4, 2000
    Assignee: 3M Innovative Properties Company
    Inventors: Kurt C. Frisch, Jr., Bruce H. Edwards, Ashok Sengupta, Lowell W. Holland, Richard G. Hansen, Ian R. Owen
  • Patent number: 5750630
    Abstract: The invention relates to novel water-soluble or water-dispersible polyurethane compounds and to compositions that contain the novel compounds and are useful, for instance, as low adhesion backsize for adhesive tapes. The invention also relates to processes for preparing the novel compounds, compositions and tapes.
    Type: Grant
    Filed: July 19, 1996
    Date of Patent: May 12, 1998
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Ashok Sengupta
  • Patent number: 5554686
    Abstract: This invention provides aqueous dispersions of externally chain extended polyurethane compositions terminated by hydrolyzable and/or hydrolyzed silyl groups and containing anionic solubilizing or emulsifying groups, particularly carboxyl groups. The invention also provides methods of making both anionically and cationically stabilized polyurethane dispersions. This invention further provides polyurethane dispersions which are substantially organic solvent free (e.g. less than about 7 weight percent organic solvent) which cure to water and solvent resistant, tough, scratch resistant, preferably light stable (non-yellowing) polyurethane films. Such films are particularly useful as coatings for wood substrates, including wood floorings, furniture, and marine surfaces.
    Type: Grant
    Filed: November 13, 1995
    Date of Patent: September 10, 1996
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Kurt C. Frisch, Jr., Bruce H. Edwards, Ashok Sengupta, Lowell W. Holland, Richard G. Hansen, Ian R. Owen