Patents by Inventor John W. Chu

John W. Chu 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: 7910679
    Abstract: Provided are bulk homogeneous polymerization processes for producing ethylene propylene random copolymers. The process includes contacting in a reactor or in a series of reactors propylene monomer, ethylene comonomer with one or more catalyst systems and optional solvent (present at less than 40 wt %), wherein the reactor train is at a temperature of between 65° C. and 180° C.
    Type: Grant
    Filed: November 14, 2008
    Date of Patent: March 22, 2011
    Assignee: ExxonMobil Research and Engineering Company
    Inventors: Gabor Kiss, Robert Patrick Reynolds, Jr., John W. Chu, Steven P. Rucker, James Richardson Lattner
  • Patent number: 7807769
    Abstract: This invention relates to an isotactic propylene homopolymer having: more than 15 and less than 100 regio defects (sum of 2,1-erythro and 2,1-threo insertions and 3,1-isomerizations) per 10,000 propylene units; an Mw of 35000 g/mol or more; a peak melting temperature of greater than 149° C.; an mmmm pentad fraction of 0.85 or more; a heat of fusion of 80 J/g or more; and a peak melting temperature minus peak crystallization temperature (Tmp?Tcp) of less than or equal to (0.907 times Tmp) minus 99.64 (Tmp?Tcp<(0.907×Tmp)?99.64), as measured in ° C. on the homopolymer having 0 wt % nucleating agent.
    Type: Grant
    Filed: December 20, 2007
    Date of Patent: October 5, 2010
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Aspy K. Mehta, Manika Varma-Nair, Gabor Kiss, Patrick Brant, Robert P. Reynolds, John W. Chu, Steven P. Rucker, Peijun Jiang
  • Patent number: 7745552
    Abstract: Reactor designs and processes for operating such reactor designs to minimize or eliminate fouling in homogeneous polymerization processes (solution and supercritical). The process includes providing a reactor with one or more feed entry ports, wherein the reactor feed components are fed through each of the one or more feed entry ports at a linear velocity of greater than or equal to 0.3 m/min. The one or more feed entry ports may also be optionally extended beyond the interior reactor wall by greater than or equal to 2% of the internal radius of the reactor to further decrease the propensity for fouling. A stirred reactor may also include a stirrer feed port for purging the stirrer with a stirrer purge stream at a linear velocity of greater than or equal to 0.3 m/min to decrease stirrer fouling.
    Type: Grant
    Filed: June 13, 2008
    Date of Patent: June 29, 2010
    Assignee: Exxonmobil Research and Engineering Company
    Inventors: Gabor Kiss, Robert P. Reynolds, Jr., Charles K. Morgan, John W. Chu, Megan Meier
  • Publication number: 20100113718
    Abstract: This invention relates to processes for producing an isotactic propylene homopolymer having more than 15 and less than 100 regio defects (sum of 2,1-erythro and 2,1-threo insertions and 3,1-isomerizations) per 10,000 propylene units; a weight-averaged molecular weight of 35000 g/mol or more; a peak melting temperature of greater than 149° C.; an mmmm pentad fraction of 0.85 or more; a heat of fusion of 80 J/g or more; and a peak melting temperature minus peak crystallization temperature (Tmp?Tcp) of less than or equal to (0.907 times Tmp) minus 99.64 (Tmp?Tcp<(0.907×Tmp)?99.64), as measured in ° C. on the homopolymer having 0 wt % nucleating agent.
    Type: Application
    Filed: November 4, 2008
    Publication date: May 6, 2010
    Inventors: Aspy K. Mehta, Manika Varma-Nair, Gabor Kiss, Robert P. Reynolds, John W. Chu, Steven P. Rucker
  • Publication number: 20100063338
    Abstract: Provided are processes for feeding ethylene into a polymerization system operating in a liquid phase or supercritical phase.
    Type: Application
    Filed: September 3, 2009
    Publication date: March 11, 2010
    Inventors: GABOR KISS, ROBERT PATRICK REYNOLDS, JR., JOHN W. CHU, JAMES RICHARDSON LATTNER, GARY MOHR
  • Publication number: 20090292085
    Abstract: Provided are methods of producing polymers with broadened molecular weight and/or composition distribution in a continuous homogeneous polymerization system utilizing reactor temperature gradients, reactor polymer concentration gradients, monomer concentration gradients, catalyst concentration gradients, and combinations thereof in the polymerization reactor. Such methods are particularly suitable when utilizing metallocene catalysts and other single-site catalysts, which generally produce polymers with narrow molecular weight and composition distribution.
    Type: Application
    Filed: May 19, 2009
    Publication date: November 26, 2009
    Inventors: Gabor Kiss, Robert Patrick Reynolds, JR., John W. Chu, Patrick Brant, James Richardson Lattner
  • Publication number: 20090163643
    Abstract: Isotactic polypropylene ethylene-propylene copolymer blends and in-line processes for producing them. The blend of polypropylene and ethylene-propylene copolymer may have between 1 and 50 wt % of isotactic polypropylene with a melt flow rate of between 0.5 and 20,000 g/10 min and a melting peak temperature of 145° C. or higher, and wherein the difference between the DSC peak melting and the peak crystallization temperatures is less than or equal to 0.5333 times the melting peak temperature minus 41.333° C., and between 50 and 99 wt % of ethylene-propylene copolymer including between 10 wt % and 20 wt % randomly distributed ethylene with a melt flow rate of between 0.5 and 20,000 g/10 min, wherein the copolymer is polymerized by a bulk homogeneous polymerization process, and wherein the total regio defects in the continuous propylene segments of the copolymer is between 40 and 150% greater than a copolymer of equivalent melt flow rate and wt % ethylene polymerized by a solution polymerization process.
    Type: Application
    Filed: December 18, 2008
    Publication date: June 25, 2009
    Inventors: Gabor Kiss, Patrick Brant, Robert Partick Reynolds, JR., Aspy K. Mehta, Manika Varma-Nair, John W. Chu, Steven P. Rucker
  • Publication number: 20090163678
    Abstract: Provided are bulk homogeneous polymerization processes for producing ethylene propylene random copolymers. The process includes contacting in a reactor or in a series of reactors propylene monomer, ethylene comonomer with one or more catalyst systems and optional solvent (present at less than 40 wt %), wherein the reactor train is at a temperature of between 65° C. and 180° C.
    Type: Application
    Filed: November 14, 2008
    Publication date: June 25, 2009
    Inventors: Gabor Kiss, Robert Patrick Reynolds, JR., John W. Chu, Steven P. Rucker, James Richardson Lattner
  • Publication number: 20090076216
    Abstract: A process for fluid phase in-line blending of plasticized polymers is provided.
    Type: Application
    Filed: September 9, 2008
    Publication date: March 19, 2009
    Inventors: Gabor Kiss, Alan Anthony Galuska, Robert Patrick Reynolds, JR., John W. Chu, Bryan R. Chapman, Patrick Brant, Sudhin Datta
  • Publication number: 20090005520
    Abstract: Reactor designs and processes for operating such reactor designs to minimize or eliminate fouling in homogeneous polymerization processes (solution and supercritical). The process includes providing a reactor with one or more feed entry ports, wherein the reactor feed components are fed through each of the one or more feed entry ports at a linear velocity of greater than or equal to 0.3 m/min. The one or more feed entry ports may also be optionally extended beyond the interior reactor wall by greater than or equal to 2% of the internal radius of the reactor to further decrease the propensity for fouling. A stirred reactor may also include a stirrer feed port for purging the stirrer with a stirrer purge stream at a linear velocity of greater than or equal to 0.3 m/min to decrease stirrer fouling.
    Type: Application
    Filed: June 13, 2008
    Publication date: January 1, 2009
    Inventors: Gabor Kiss, Robert P. Reynolds, JR., Charles K. Morgan, John W. Chu, Megan Meier
  • Publication number: 20080214767
    Abstract: This invention relates to an isotactic propylene homopolymer having: more than 15 and less than 100 regio defects (sum of 2,1-erythro and 2,1-threo insertions and 3,1-isomerizations) per 10,000 propylene units; an Mw of 35000 g/mol or more; a peak melting temperature of greater than 149° C.; an mmmm pentad fraction of 0.85 or more; a heat of fusion of 80 J/g or more; and a peak melting temperature minus peak crystallization temperature (Tmp?Tcp) of less than or equal to (0.907 times Tmp) minus 99.64 (Tmp?Tcp<(0.907×Tmp)?99.64), as measured in ° C. on the homopolymer having 0 wt % nucleating agent.
    Type: Application
    Filed: December 20, 2007
    Publication date: September 4, 2008
    Inventors: Aspy K. Mehta, Manika Varma-Nair, Gabor Kiss, Patrick Brant, Robert P. Reynolds, John W. Chu, Steven P. Rucker, Peijun Jiang
  • Patent number: 4742309
    Abstract: An improved line receiver with high common mode rejection is operable at voltages above the power supply voltage (VCC) as well as below ground. Input resistors provide high input impedence as well as means through which current summing of current mirror currents at the input transistor base nodes is translated into voltage drops which boosts the common mode rejection range of the circuit. Built-in hysteresis circuitry ensures proper detection of non-common mode signals. The high input impedence and high sensitivity allow multiple receivers of the type to be connected in parallel across a common bus for interrogation by a remote system. The preferred embodiment of the present invention is implemented in integrated circuit technology.
    Type: Grant
    Filed: December 31, 1986
    Date of Patent: May 3, 1988
    Assignee: Dual-Lite Manufacturing Inc.
    Inventor: John W. Chu
  • Patent number: 4682143
    Abstract: An improved thin film resistor material is disclosed which comprises a chromium-silicon-carbon material containing from about 25 to 35 wt. % chromium, about 45 to 55 wt. % silicon, and about 20 to 30 wt. % carbon. The resistor material is further characterized by a resistivity of greater than about 800 ohms per square to less than about 1200 ohms per square, a temperature coefficient of resistance of less than 160 ppm per degree Centigrade, and a lifetime stability of less than 0.1% change in resistivity. In the preferred embodiment, the resistor material contains 31 wt. % chromium, 46 wt. % silicon, and 24 wt. % carbon.
    Type: Grant
    Filed: October 30, 1985
    Date of Patent: July 21, 1987
    Assignee: Advanced Micro Devices, Inc.
    Inventors: John W. Chu, Bradley J. Bereznak
  • Patent number: 4608503
    Abstract: A dual bus driver including a voltage input, a current source, a single data input, a first driver transistor for driving one bus, a second driver transistor for driving the other bus, a first pair of differential transistors for turning on either the first driver transistor or the second driver transistor to couple an input signal at the data input to the one bus or the other bus, and a second pair of differential transistors for disabling both driver transistors. By providing a driver that drives both buses, reduced power consumption, fewer circuit components and less integrated circuit layout complexities are achieved.
    Type: Grant
    Filed: October 25, 1982
    Date of Patent: August 26, 1986
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Thomas H. Wong, John W. Chu