Patents by Inventor James C. Stevens

James C. Stevens 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: 5460818
    Abstract: A polymer blend composition comprising:(a) from 0.5 to 99 percent by weight, based on the total weight of (a), (b), and (c), of an aliphatic .alpha.-olefin homopolymer or interpolymer, or an interpolymer of an .alpha.-olefin and a non-aromatic monomer interpolymerizable therewith;(b) from 0.5 to 99 percent by weight, based on the total weight of (a), (b), and (c), of a homopolymer or interpolymer of monovinylidene aromatic monomers, or an interpolymer of monovinylidene aromatic monomer and a monomer interpolymerizable therewith other than an aliphatic .alpha.-olefin; and(c) from 0.5 to 99 percent by weight, based on the total weight of (a), (b), and (c), of a substantially random interpolymer comprising an .alpha.-olefin and a vinylidene aromatic monomer.
    Type: Grant
    Filed: April 12, 1994
    Date of Patent: October 24, 1995
    Assignee: The Dow Chemical Company
    Inventors: Chung P. Park, George P. Clingerman, Francis J. Timmers, James C. Stevens, David E. Henton
  • Patent number: 5431159
    Abstract: Non-invasive oximetry wherein red and infrared light from light sources energized at different frequencies is applied to arterial blood-containing tissue of a living subject. The red and infrared light coming from this tissue is sensed in order to obtain frequency-muliplexed information as to the absorption of said light by said tissue, the information being processed in order to derive therefrom a measure of percent oxygen saturation of said blood. The processing includes filtering for separating information represented by red light absorption from information represented by infrared light absorption. In particular, both notch and bandpass filters are used, and AM detectors provide for further separating such information into DC and AC components.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: July 11, 1995
    Assignee: Sentinel Monitoring, Inc.
    Inventors: William Baker, James C. Stevens
  • Patent number: 5425872
    Abstract: Group 4 metal complexes useful as addition polymerization catalysts are prepared by electrolysis of cyclopentadienyl metal complexes under inert electrolysis conditions.
    Type: Grant
    Filed: July 15, 1994
    Date of Patent: June 20, 1995
    Assignee: The Dow Chemical Company
    Inventors: David D. Devore, Robert D. Mussell, James C. Stevens, Francis J. Timmers
  • Patent number: 5399635
    Abstract: Cationic Group 4 or Lanthanide metal catalysts containing a single, delocalized .pi.-bonded group are prepared by contacting a metal complex with a carbonium salt of a compatible, non-coordinating anion.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: March 21, 1995
    Assignee: The Dow Chemical Company
    Inventors: David R. Neithamer, James C. Stevens
  • Patent number: 5380810
    Abstract: Substantially linear olefin polymers having a melt flow ratio, I.sub.10 /I.sub.2, .gtoreq.5.63, a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation: M.sub.w /M.sub.n .ltoreq.(I.sub.10 /I.sub.2)-4.63, and a critical shear stress at onset of gross melt fracture of greater than about 4.times.10.sup.6 dyne/cm.sup.2 and their method of manufacture are disclosed. The substantially linear olefin polymers preferably have at least about 0.01 long chain branches/1000 carbons and a molecular weight distribution from about 1.5 to about 2.5. The new polymers have improved processability over conventional olefin polymers and are useful in producing fabricated articles such as fibers, films, and molded parts.
    Type: Grant
    Filed: April 7, 1993
    Date of Patent: January 10, 1995
    Assignee: The Dow Chemical Company
    Inventors: Shih-Yaw Lai, John R. Wilson, George W. Knight, James C. Stevens
  • Patent number: 5374696
    Abstract: Complexes useful as addition polymerization catalysts, a process for their manufacture and addition polymerization processes wherein the complex comprises a Group 4 metal in the .sup.+ 3 oxidation state, a delocalized .pi.-bonding moiety, and at least one stabilizing ligand.
    Type: Grant
    Filed: January 21, 1993
    Date of Patent: December 20, 1994
    Assignee: The Dow Chemical Company
    Inventors: Robert K. Rosen, Peter N. Nickias, David D. Devore, James C. Stevens, Francis J. Timmers
  • Patent number: 5372682
    Abstract: Group 4 metal complexes useful as addition polymerization catalysts are prepared by electrolysis of cyclopentadienyl metal complexes under inert electrolysis conditions.
    Type: Grant
    Filed: June 24, 1993
    Date of Patent: December 13, 1994
    Assignee: The Dow Chemical Company
    Inventors: David D. Devore, Robert D. Mussell, James C. Stevens, Francis J. Timmers
  • Patent number: 5369136
    Abstract: Disclosed is an ethylenic polymer foam structure comprising an ethylenic polymer material. The ethylenic polymer material contains a substantially linear ethylenic polymer having: a) a melt flow ratio, I.sub.10 /I.sub.2, .gtoreq.5.63; b) a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation M.sub.w /M.sub.n .gtoreq.(I.sub.10 /I.sub.2)-4.63; and c) a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear olefin polymer having about the same I.sub.2 and M.sub.w /M.sub.n. The foam structures have toughness and elasticity similar to those formed from conventional LLDPE without the poor dimensional stability and foam quality associated with those structures. The foam structures have foam quality similar to those made with conventional LDPE but with enhanced toughness and elasticity. Further disclosed is a process for making the above foam structure and making it in a foam bead form.
    Type: Grant
    Filed: April 11, 1994
    Date of Patent: November 29, 1994
    Assignee: The Dow Chemical Company
    Inventors: Chung P. Park, James C. Stevens, George W. Knight
  • Patent number: 5350723
    Abstract: Cationic Group 4 or Lanthanide metal catalysts containing a single, delocalized n-bonded group are prepared by contacting a metal complex with a carbonium salt of a compatible, non-coordinating anion.
    Type: Grant
    Filed: May 15, 1992
    Date of Patent: September 27, 1994
    Assignee: The Dow Chemical Company
    Inventors: David R. Neithamer, James C. Stevens
  • Patent number: 5340840
    Abstract: Disclosed is an ethylenic polymer foam structure comprising an ethylenic polymer material. The ethylenic polymer material contains a substantially linear ethylenic polymer having: a) a melt flow ratio, I.sub.10 I.sub.2, .gtoreq.5.63; b) a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation M.sub.w /M.sub.n .ltoreq.(I.sub.10 /I.sub.2)-4.63; and c) a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear olefin polymer having about the same I.sub.2 and M.sub.w /M.sub.n. The foam structures have toughness and elasticity similar to those formed from conventional LLDPE without the poor dimensional stability and foam quality associated with those structures. The foam structures have foam quality similar to those made with conventional LDPE but with enhanced toughness and elasticity. Further disclosed is a process for making the above foam structure and making it in a foam bead form.
    Type: Grant
    Filed: April 28, 1993
    Date of Patent: August 23, 1994
    Assignee: The Dow Chemical Company
    Inventors: Chung P. Park, James C. Stevens, George W. Knight
  • Patent number: 5278272
    Abstract: Elastic substantially linear olefin polymers are disclosed which have very good processability, including processing indices (PI's) less than or equal to 70 percent of those of a comparative linear olefin polymer and a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a traditional linear olefin polymer at about the same I.sub.2 and M.sub.w /M.sub.n. The novel polymers have higher low/zero shear viscosity and lower high shear viscosity than comparative linear olefin polymers.
    Type: Grant
    Filed: September 2, 1992
    Date of Patent: January 11, 1994
    Assignee: The Dow Chemical Company
    Inventors: Shih-Yaw Lai, John R. Wilson, George W. Knight, James C. Stevens
  • Patent number: 5272236
    Abstract: Substantially linear olefin polymers having a melt flow ratio, I.sub.10 /I.sub.2, .gtoreq.5.63, a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation: M.sub.w /M.sub.n .ltoreq.(I.sub.10 /I.sub.2)-4.63, and a critical shear stress at onset of gross melt fracture of greater than about 4.times.10.sup.6 dyne/cm.sup.2 and their method of manufacture are disclosed. The substantially linear olefin polymers preferably have at least about 0.01 long chain branches/1000 carbons and a molecular weight distribution from about 1.5 to about 2.5. The new polymers have improved processability over conventional olefin polymers and are useful in producing fabricated articles such as fibers, films, and molded parts.
    Type: Grant
    Filed: October 15, 1991
    Date of Patent: December 21, 1993
    Assignee: The Dow Chemical Company
    Inventors: Shih-Yaw Lai, John R. Wilson, George W. Knight, James C. Stevens, Pak-Wing S. Chum
  • Patent number: 5132380
    Abstract: A monocyclopentadienyl or substituted monocyclopentadienyl metal complex containing compound useful as a polymerization catalyst corresponding to the formula:CpMX.sub.n.sup.+ A.sup.-wherein:Cp is a single .eta..sup.5 -cyclopentadienyl or .eta..sup.5 -substituted cyclopentadienyl group optionally covalently bonded to M through a substituent;M is a metal of Group 3-10 or the Lanthanide Series of the Periodic Table bound in an .eta..sup.5 bonding mode to the cyclopentadienyl or substituted cyclopentadienyl group;X each occurrence independently is selected from the group consisting of hydride, halo, alkyl, aryl, silyl, germyl, aryloxy, alkoxy, amide, siloxy, neutral Lewis base ligands and combinations thereof having up to 20 non-hydrogen atoms, and optionally one X together with Cp forms a metallocycle with M;R is alkyl or aryl of up to 10 carbons;n is one or two depending on the valence of M; andA is a noncoordinating, compatible anion of a Bronsted acid salt.
    Type: Grant
    Filed: September 12, 1991
    Date of Patent: July 21, 1992
    Assignee: The Dow Chemical Company
    Inventors: James C. Stevens, David R. Neithamer
  • Patent number: 5081231
    Abstract: Novel di(poly-substituted cyclopentadienyl)-allylic uranium complexes can be employed to catalyze the dimerization of propylene to form 4-methyl-1-pentene selectively. The novel catalyst complexes can be prepared from novel di(poly-substituted cyclopentadienyl)-U(IV) monohalo monoallylic complexes.
    Type: Grant
    Filed: January 16, 1990
    Date of Patent: January 14, 1992
    Assignee: The Dow Chemical Company
    Inventors: James C. Stevens, William A. Fordyce
  • Patent number: 5064802
    Abstract: A monocyclopentadienyl or substituted monocyclopentadienyl metal complex containing compound useful as a polymerization catalyst corresponding to the formula:CpMX.sub.n.sup.+ A.sup.-wherein:Cp is a single .eta..sup.5 -cyclopentadienyl or .eta..sup.5 -substituted cyclopentadienyl group optionally covalently bonded to M through a substituent;M is a metal of Group 3-10 or the Lanthanide Series of the Periodic Table bound in the .eta..sup.5 bonding mode to the cyclopentadienyl or substituted cyclopentadienyl group;X each occurrence independently is selected from the group consisting of hydride, halo, alkyl, aryl, silyl, germyl, aryloxy, alkoxy, amide, siloxy, neutral Lewis base ligands and combinations thereof having up to 20 non-hydrogen atoms, and optionally one X together with Cp forms a metallocycle with M;R is alkyl or aryl of up to 10 carbons;n is one or two depending on the valence of M; andA is a noncoordinating, compatible anion of a Bronsted acid salt.
    Type: Grant
    Filed: July 3, 1990
    Date of Patent: November 12, 1991
    Assignee: The Dow Chemical Company
    Inventors: James C. Stevens, David R. Neithamer
  • Patent number: 5050093
    Abstract: An improved method and apparatus for inspecting electrical wire (10) is provided. A wire respooling machine (22) advances the electrical wire (10) from a take-off spool (12) to a take-up spool (14). An encoder (24) senses the rotation of the calibrated wheel (15) that is rotated by the electrical wire (10) and produces encoded wire length data. A splice detector (20) senses splices and insulation flaws in the wire (10) and produces a pulse for each detected splice and flaw. A controller (26) receives the encoded wire length data and detected splice and flaw pulses and produces splice and flaw location data representing the locations of the detected splices and flaws relative to the leading end of the wire (10). The controller (26) generates report data that includes said wire length data and said splice and flaw location data. A printer (28) prints the report data in a hard copy format.
    Type: Grant
    Filed: October 19, 1989
    Date of Patent: September 17, 1991
    Assignee: The Boeing Company
    Inventors: Mahender Reddy, Douglas M. Sargent, Jerome D. Johnson, James C. Stevens
  • Patent number: 4960869
    Abstract: Novel di(poly-substituted cyclopentadienyl)-allylic uranium complexes can be employed to catalyze the dimerization of propylene to form 4-methyl-1-pentene selectively. The novel catalyst complexes can be prepared from novel di(poly-substituted cyclopentadienyl)-U-(IV) monohalo monoallylic complexes.
    Type: Grant
    Filed: August 1, 1988
    Date of Patent: October 2, 1990
    Assignee: The Dow Chemical Company
    Inventors: James C. Stevens, William A. Fordyce
  • Patent number: 4935906
    Abstract: Images of underwater features, animate and inanimate, are produced from substantial distances in any direction around a boat, using small and easily mountable sonar devices, including three sonar transducers, two being stationary and the third being directable, the transducers being operable at various ultrasonic frequencies. Under keyboard control and using completely integrated electronic circuitry, images and echo sounding reports are generated on a graphic video display. The images include a sector-shaped image from a sector scan which covers a selected range of azimuth angles at a selected down angle.
    Type: Grant
    Filed: January 4, 1988
    Date of Patent: June 19, 1990
    Assignee: Span, Inc.
    Inventors: William Baker, Kevin E. Nortrup, James C. Stevens
  • Patent number: 4929699
    Abstract: Ethylenically unsaturated polymers are hydrogenated by use of a bis(alkyl substituted cyclopentadienyl) lanthanide catalyst.
    Type: Grant
    Filed: May 9, 1989
    Date of Patent: May 29, 1990
    Assignee: The Dow Chemical Company
    Inventors: David R. Wilson, James C. Stevens
  • Patent number: 4918368
    Abstract: A battering charging system is controlled by a microprocessor to charge and discharge batteries while periodically effecting monitoring and control operations in which battery current data are registered to accumulate capacity data in a memory and to thereafter display such data which includes both charge and discharge capacity data. The system has different modes of operation which may be selected by a user, including a charge mode, a discharge mode and an autocycle mode. In the autocycle mode, efficiency rate data is computed and displayed.
    Type: Grant
    Filed: February 29, 1988
    Date of Patent: April 17, 1990
    Assignee: Span, Inc.
    Inventors: William Baker, James C. Stevens, Phong B. Chau