Patents by Inventor Richard L. Leonard

Richard L. Leonard 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: 5667743
    Abstract: A process for wet spinning a meta-aramid polymer solutions having a salt content of at least 3 percent by weight produces a one step, fully wet drawable fiber that has desirable physical properties without subjecting the fiber to hot stretching.
    Type: Grant
    Filed: May 21, 1996
    Date of Patent: September 16, 1997
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Tsung-Ming Tai, David J. Rodini, James C. Masson, Richard L. Leonard
  • Patent number: 4220535
    Abstract: Transversely-fed permeators containing a plurality of selectively permeable hollow fibers suitable for the selective permeation of at least one fluid in a fluid mixture containing at least one other fluid, said fibers being generally parallelly oriented within an elongated shell, are provided with at least one essentially fluid impermeable partition which is substantially transverse to the orientation of the hollow fibers and intermediate a fluid ingress means and a fluid egress means, each of said fluid ingress means and fluid egress means communicating through the elongated shell to the exterior of the hollow fibers, said at least one partition defining zones in said permeator, wherein the zone into which the fluid ingress means communicates is significantly smaller in available membrane surface area to effect the fluid separation than the available membrane surface area in at least one subsequent zone, and means for fluid communication between said zones such that the fluid flow in each zone is substantial
    Type: Grant
    Filed: August 4, 1978
    Date of Patent: September 2, 1980
    Assignee: Monsanto Company
    Inventor: Richard L. Leonard
  • Patent number: 4209307
    Abstract: A method is provided for fabricating asymmetric acrylic hollow fibers for use in separatory processes as a selective membrane. The fibers are highly permeable and exhibit a high degree of selectivity in discriminating mixtures into their various components. The fibers are formed by extruding an acrylic polymer solution through an annular orifice while simultaneously injecting a coagulating fluid into the bore of the fibers extrudate as it is formed. The extrusion may be directly into a coagulating bath maintained at a temperature of from 60.degree. to 80.degree. or alternatively the freshly extruded fiber may be first passed through an air space (evaporation zone) and thence into the coagulating bath. Following coagulation, the fibers are water washed to remove residual solvent.
    Type: Grant
    Filed: March 20, 1978
    Date of Patent: June 24, 1980
    Assignee: Monsanto Company
    Inventor: Richard L. Leonard
  • Patent number: 4171001
    Abstract: A wig and a method of making a weft for use in making the wig wherein 5 to 50 weight percent of a first modacrylic fiber having a denier of 30 to 50 and a shrinkage of 5 to 20 percent at a temperature of 120.degree. C. is blended with 95 to 50 weight percent of the second modacrylic fiber having a denier of 30 to 50 and a shrinkage of at least five percent less than the shrinkage of the first fiber at a temperature of 120.degree. C. The blended fibers are assembled and sewed to form a weft and the weft is then heated to a temperature of 110.degree. to 130.degree. C. for a time period of 1 to 5 minutes to shrink the fibers. This produces an interaction of high shrinking and low shrinking fibers, thus imparting unique properties of cover, manageability and naturalness to the weft.
    Type: Grant
    Filed: November 21, 1977
    Date of Patent: October 16, 1979
    Assignee: Monsanto Company
    Inventors: Richard L. Leonard, Allan D. Chernack
  • Patent number: 4084036
    Abstract: Asymmetric acrylic hollow fibers for use in separatory processes as a selective membrane. The fibers are highly permeable and exhibit a high degree of selectivity in discriminating mixtures into their various components. The fibers are formed by extruding an acrylic polymer solution through an annular orifice while simultaneously injecting a coagulating fluid into the bore of the fiber extrudate as it is formed. The extrusion may be directly into a coagulating bath maintained at a temperature of from 60.degree. to 80.degree. C. or alternatively the freshly extruded fiber may be first passed through an air space (evaporation zone) and thence into the coagulating bath. Following coagulation, the fibers are water washed to remove residual solvent.
    Type: Grant
    Filed: August 13, 1976
    Date of Patent: April 11, 1978
    Assignee: Monsanto Company
    Inventor: Richard L. Leonard
  • Patent number: 4082658
    Abstract: Hollow fiber membranes of copolymers of ethylene with 5 to 20 weight percent of copolymerizable vinyl monomers display much superior permeabilities to organic compounds than do polyethylene hollow fibers, less loss of permeability upon storage or use and good strength. Use of such new hollow fiber membranes affords an improved process for the separation of phenols from aqueous solutions thereof through permeation.
    Type: Grant
    Filed: February 9, 1977
    Date of Patent: April 4, 1978
    Assignee: Monsanto Company
    Inventors: Alfred Keith Fritzsche, Richard L. Leonard
  • Patent number: 3975478
    Abstract: A method is provided for fabricating asymmetric acrylic hollow fibers for use in separatory processes as a selective membrane. The fibers are highly permeable and exhibit a high degree of selectivity in discriminating mixtures into their various components. The fibers are formed by extruding an acrylic polymer solution through an annular orifice while simultaneously injecting a coagulating fluid into the bore of the fiber extrudate as it is formed. The extrusion may be directly into a coagulating bath maintained at a temperature of from 60.degree. to 80.degree.C. or alternatively the freshly extruded fiber may be first passed through an air space (evaporation zone) and thence into the coagulating bath. Following coagulation, the fibers are water washed to remove residual solvent.
    Type: Grant
    Filed: August 14, 1974
    Date of Patent: August 17, 1976
    Assignee: Monsanto Company
    Inventor: Richard L. Leonard