Kevin D Lawson

US Patent:

7183234, Feb 27, 2007

Filed:

Apr 29, 2004

Appl. No.:

10/835337

Inventors:

Robert Tan Li - Houston TX, US
Kevin Wayne Lawson - Seabrook TX, US
Aspy Keki Mehta - Humble TX, US
Prasadarao Meka - Seabrook TX, US

Assignee:

ExxonMobil Chemical Patents Inc. - Houston TX

International Classification:

C08F 4/642
C08F 4/649

US Classification:

502116, 5261248

Abstract:

The present invention provides catalyst systems including a Ziegler-Natta or Ziegler-Natta-type catalyst in combination with a mixture of certain electron donors.

US Patent:

7851554, Dec 14, 2010

Filed:

Oct 27, 2008

Appl. No.:

12/258981

Inventors:

Prasadarao Meka - Seabrook TX, US
Kevin Wayne Lawson - Houston TX, US

Assignee:

ExxonMobil Chemical Patents Inc. - Houston TX

International Classification:

C08L 23/00
C08L 23/10

US Classification:

525191, 525240, 524536

Abstract:

Disclosed is a propylene impact copolymer comprising a first polypropylene having an MFRwithin the range from 15 to 40 dg/min; a second polypropylene having an MFRwithin the range from 50 to 190 dg/min; an elastomeric polymer; and wherein the propylene impact copolymer has an MFRwithin the range from 6 to 18 dg/min; a 1% Secant Flexural Modulus of greater than 150 kpsi (1030 MPa); and an Izod Impact at 25 C. of greater than 10 ft-lbs/in (530 J/m). The impact copolymer may be produced in a two or three tandem-reactor system wherein the catalyst composition used in the second reactor to produce the second polypropylene is different from the catalyst composition used in the first reactor to produce the first polypropylene.

US Patent:

8076419, Dec 13, 2011

Filed:

Nov 10, 2010

Appl. No.:

12/943364

Inventors:

Prasadarao Meka - Seabrook TX, US
Kevin Wayne Lawson - Houston TX, US

Assignee:

ExxonMobil Chemical Patents Inc. - Houston TX

International Classification:

C08F 8/00
C08L 23/04
C08L 23/10

US Classification:

525191, 525240

Abstract:

Disclosed is a propylene impact copolymer comprising a first polypropylene having an MFRwithin the range from 15 to 40 dg/min; a second polypropylene having an MFRwithin the range from 50 to 190 dg/min; an elastomeric polymer; and wherein the propylene impact copolymer has an MFRwithin the range from 6 to 18 dg/min; a 1% Secant Flexural Modulus of greater than 150 kpsi (1030 MPa); and an Izod Impact at 25 C. of greater than 10 ft-lbs/in (530 J/m). The impact copolymer may be produced in a two or three tandem-reactor system wherein the catalyst composition used in the second reactor to produce the second polypropylene is different from the catalyst composition used in the first reactor to produce the first polypropylene.

US Patent:

20130171735, Jul 4, 2013

Filed:

Jul 8, 2010

Appl. No.:

13/702861

Inventors:

Kevin W. Lawson - Houston TX, US
Lawrence C. Smith - Houston TX, US

Assignee:

ExxonMobil Chemical Patents Inc. - Law Technology - Baytown TX

International Classification:

G01N 9/36

US Classification:

436 55, 422119

Abstract:

Bubble formation is monitored in a reactor such as a loop polymerization reactor which effectively operates at pressures above or near the vapor pressure of a circulating slurry liquid. The method measures a property of the reactor composition at a first location within the reactor, and then at a second location within the reactor. The process is repeated, followed by determining if the difference in measured property varies from a reference difference, derived under bubble-free conditions. When the difference in measured physical property has changed relative to the reference difference, an effect may be implemented, e.g., increase of reactor pressure, decrease of composition vapor pressure, and decrease of reactor temperature, to an extent sufficient to reduce or eliminate bubbling.

US Patent:

20130203946, Aug 8, 2013

Filed:

Jul 16, 2010

Appl. No.:

13/702845

Inventors:

Kevin W. Lawson - Houston TX, US
John D. Hedengren - Provo UT, US
Lawrence C. Smith - Houston TX, US

International Classification:

C08F 2/01

US Classification:

526 60

Abstract:

Disclosed herein are methods for controlling bubble formation in a polymerization reactor. The method includes: (a) determining a concentration of at least one component at a location in the reactor using a mathematical model; (b) determining a vapor pressure of the composition based at least in part upon the concentration of the component; (c) determining an operating pressure of the reactor at the location; (d) determining a pressure difference as ΔP =P-P, wherein Pis the operating pressure and Pis the vapor pressure; (e) comparing the ΔP to a threshold value; and (f) implementing an effect when the ΔP is less than the threshold value.

US Patent:

20230077569, Mar 16, 2023

Filed:

Feb 12, 2021

Appl. No.:

17/759598

Inventors:

- Baytown TX, US
Ranadip GANGULY - Houston TX, US
Christopher G. BAUCH - Seabrook TX, US
Blu E. ENGLEHORN - Houston TX, US
Xiaodan ZHANG - Houston TX, US
Mark S. CHAHL - Friendswood TX, US
Kevin W. LAWSON - Houston TX, US
Xuejia YAN - Manvel TX, US

Assignee:

ExxonMobil Chemical Patents Inc. - Baytown TX

International Classification:

C08F 210/06
C08L 23/12

Abstract:

Processes for forming a polypropylene composition are provided herein comprising the steps of making a first propylene-based copolymer having a molecular weight distribution between 3 to 8.5, and making a second propylene-based polymer in the presence of the first propylene-based polymer to produce the polypropylene composition having a high molecular weight tail in the amount of between 1.0 wt. % and 10.0 wt. %. The polypropylene compositions produced have a broad molecular weight distribution and high molecular weight tail to provide improved stiffness while retaining toughness.

US Patent:

20200231710, Jul 23, 2020

Filed:

Aug 19, 2016

Appl. No.:

15/759002

Inventors:

- Baytown TX, US
Kevin W. Lawson - Houston TX, US
Peijun Jiang - katy TX, US
Gabor Kiss - Hampton NJ, US

International Classification:

C08F 2/01
C08F 2/04
C08F 10/02
C08F 10/06
C08F 210/16
C08F 2/38
B01J 8/00
C08F 4/642

Abstract:

This invention relates to a polymerization process for forming polymer comprising: contacting (typically in a solution or slurry phase), a monomer and a catalyst system in a reaction zone comprising at least one spiral heat exchanger and recovering polymer, wherein the monomer, the catalyst system and the polymer flow through the at least one spiral heat exchanger in a cross-flow direction relative to spirals of the at least one spiral heat exchanger.

US Patent:

20200231718, Jul 23, 2020

Filed:

Jun 6, 2018

Appl. No.:

16/634901

Inventors:

- Baytown TX, US
Kevin W. Lawson - Houston TX, US

International Classification:

C08F 6/00
B01J 19/06
B01J 19/24
B01D 3/06

Abstract:

Methods for separating gaseous components, such as unreacted hydrocarbon monomer and/or solvent, from polyolefin solids are provided. The methods include contacting a first stream including polyolefin solids and gaseous unreacted hydrocarbon monomer and/or solvent with a first purge gas in a gas-solid separation vessel to separate the gaseous unreacted hydrocarbon monomer and/or solvent from the polyolefin solids to produce a second stream including polyolefin solids substantially free of gaseous unreacted hydrocarbon monomer and/or solvent and a third stream including the gaseous unreacted hydrocarbon monomer and/or solvent. The first purge gas includes hydrocarbon monomer and/or solvent and has a temperature of at least about 70 C. when entering the gas-solid separation vessel. Systems for carrying out such methods are also provided.