Patents by Inventor Periagaram S. Ravishankar

Periagaram S. Ravishankar 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: 10538656
    Abstract: Provided herein are polymerization processes and polymer compositions including reactor blends formed by such polymerization processes. The polymerization processes include copolymerization using two metallocene catalyst systems: the first catalyst system capable of producing polymers having 60% or more vinyl terminations, the second catalyst system capable of producing high molecular weight polymers, preferably incorporating at least some of the polymers produced by the first catalyst system into the high molecular weight polymers. The reactor blends formed thereby therefore include first and second copolymer components, which may differ in monomer content and weight-average molecular weight (Mw). Furthermore, the reactor blends may exhibit advantageous rheological properties, at least some of which are consistent with long-chain branching. Preferred reactor blends comprise ethylene-propylene-diene (EPDM) terpolymers.
    Type: Grant
    Filed: February 4, 2019
    Date of Patent: January 21, 2020
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Jo Ann M. Canich, Rainer Kolb, Periagaram S. Ravishankar, Phillip T. Matsunaga, Peijun Jiang, Rhutesh K. Shah, Narayanaswami Dharmarajan
  • Patent number: 10508179
    Abstract: A process for producing a thermoplastic vulcanizate, the process comprising: (i) charging a reactor with an oil-extended olefinic copolymer rubber, where the rubber is synthesized by a single-site catalyst, characterized by a multi-modal molecular weight distribution, and includes greater than 10 parts by weight extender oil per 100 parts by weight rubber; (ii) charging the reactor, contemporaneously or sequentially with respect to the rubber, with a thermoplastic resin, an oil, and a cure system to provide a pre-vulcanized mixture; and (iii) mixing the rubber, thermoplastic resin, oil, and cure system at a temperature above the melt temperature of the thermoplastic resin to thereby cause dynamic vulcanization of the rubber and produce the thermoplastic vulcanizate.
    Type: Grant
    Filed: January 29, 2018
    Date of Patent: December 17, 2019
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Oscar O. Chung, Periagaram S. Ravishankar, Porter C. Shannon, John P. Soisson
  • Patent number: 10457801
    Abstract: Processes are provided which include copolymerization using one or both of a metallocene catalyst capable of producing high molecular weight polymers and a metallocene catalyst capable of producing polymers having 60% or more vinyl terminations. Polymerization processes include dual catalyst polymerization in a single polymerization zone comprising both metallocene catalysts. Other processes include serial or parallel polymerizations in multiple polymerization zones, using either or both catalysts in each polymerization zone. Such polymerization processes produce reactor blends, and are particularly suited for producing copolymer compositions (such as EP or EPDM copolymer compositions) exhibiting improved melt elasticity and rheological properties.
    Type: Grant
    Filed: December 28, 2015
    Date of Patent: October 29, 2019
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Jo Ann M. Canich, Rainer Kolb, Periagaram S. Ravishankar, Phillip T. Matsunaga, Peijun Jiang, Rhutesh K. Shah, Narayanaswami Dharmarajan
  • Publication number: 20190309236
    Abstract: This application relates to copolymer compositions and copolymerization processes, as well as to lubricating oil compositions comprising such copolymer compositions as viscosity index improvers, and base oil. The copolymer compositions may be made using two different metallocene catalysts: one capable of producing high molecular weight copolymers; and one suitable for producing lower molecular weight copolymers having at least a portion of vinyl terminations, and the copolymer compositions produced thereby. Copolymer compositions may comprise (1) a first ethylene copolymer fraction having high molecular weight, exhibiting branching topology, and having relatively lower ethylene content (based on the weight of the first ethylene copolymer fraction); and (2) a second ethylene copolymer fraction having low molecular weight, exhibiting linear rheology, and having relatively higher ethylene content (based on the weight of the second ethylene copolymer fraction).
    Type: Application
    Filed: June 14, 2017
    Publication date: October 10, 2019
    Inventors: Jingwen Zhang, Rainer Kolb, Andy H. Tsou, Periagaram S. Ravishankar, Jo Ann M. Canich, Francis C. Rix
  • Patent number: 10385198
    Abstract: Provided herein are metallocene-catalyzed polymer compositions that exhibit advantageous rheological properties, at least some of which are consistent with long-chain branching, as well as polymerization processes suitable for forming such polymer compositions. The polymer compositions may have both LCB index measured at 125° C. of less than 5; and phase angle ? at complex shear modulus G*=100,000 Pa of less than about 54.5°, as determined at 125° C. The polymer compositions of particular embodiments are reactor blends, preferably of ethylene copolymers (e.g., ethylene-propylene (EP) copolymers and/or ethylene-propylene-diene (EPDM) terpolymers). The reactor blend may include first and second copolymer components, which may differ in monomer content and weight-average molecular weight (Mw).
    Type: Grant
    Filed: December 28, 2015
    Date of Patent: August 20, 2019
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Jo Ann M. Canich, Rainer Kolb, Periagaram S. Ravishankar, Phillip T. Matsunaga, Peijun Jiang, Rhutesh K. Shah, Narayanaswami Dharmarajan
  • Patent number: 10316176
    Abstract: The present disclosure is directed to polymer compositions that can be useful as viscosity modifiers, comprising (a) a first ethylene-?-olefin copolymer having an ethylene content of from about 60 to about 80 wt % and (b) a second ethylene-?-olefin copolymer having an ethylene content of from about 40 to about 60 wt %. The polymer composition comprises about 35 wt % to about 50 wt of the first ethylene-?-olefin copolymer and about 50 wt % to about 65 wt % of the second ethylene-?-olefin copolymer. The polymer compositions are made by comprising producing a first ethylene-?-olefin copolymer in a first reactor, directing the first copolymer to a second reactor, producing the second ethylene-?-olefin copolymer in the second reactor and forming the polymer composition.
    Type: Grant
    Filed: October 9, 2014
    Date of Patent: June 11, 2019
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Periagaram S. Ravishankar, Rainer Kolb
  • Publication number: 20190169322
    Abstract: Processes are provided which include copolymerization using two different metallocene catalysts, one capable of producing high Mooney-viscosity polymers and one suitable for producing lower Mooney-viscosity polymers having at least a portion of vinyl terminations. The two catalysts may be used together in polymerization to produce copolymer compositions of particularly well-tuned properties. For instance, polymerizations are contemplated to produce high-Mooney metallocene polymers that exhibit excellent processability and elasticity, notwithstanding their high Mooney viscosity. Other polymerizations are also contemplated in which lower-Mooney metallocene polymers are produced, which also exhibit excellent processability and elasticity, while furthermore having excellent cure properties suitable in curable elastomer compound applications.
    Type: Application
    Filed: June 14, 2017
    Publication date: June 6, 2019
    Inventors: Francis C. Rix, Rhutesh K. Shah, Rainer Kolb, Jo Ann M. Canich, Peijun Jiang, Periagaram S. Ravishankar, Syamal Tallury
  • Publication number: 20190169413
    Abstract: Provided herein are polymerization processes and polymer compositions including reactor blends formed by such polymerization processes. The polymerization processes include copolymerization using two metallocene catalyst systems: the first catalyst system capable of producing polymers having 60% or more vinyl terminations, the second catalyst system capable of producing high molecular weight polymers, preferably incorporating at least some of the polymers produced by the first catalyst system into the high molecular weight polymers. The reactor blends formed thereby therefore include first and second copolymer components, which may differ in monomer content and weight-average molecular weight (Mw). Furthermore, the reactor blends may exhibit advantageous rheological properties, at least some of which are consistent with long-chain branching. Preferred reactor blends comprise ethylene-propylene-diene (EPDM) terpolymers.
    Type: Application
    Filed: February 4, 2019
    Publication date: June 6, 2019
    Inventors: Jo Ann M. Canich, Rainer Kolb, Periagaram S. Ravishankar, Phillip T. Matsunaga, Peijun Jiang, Rhutesh K. Shah, Narayanaswami Dharmarajan
  • Publication number: 20190134876
    Abstract: A method of forming a blown film comprising extruding a molten composition through a die opening to form a film; wherein the molten composition comprises at least one polyethylene and within the range from 0.10 wt % to 10 wt % of a cyclic-diene terpolymer by weight of the composition; causing the film to progress in a direction away from the die opening; cooling the film at a distance from the die opening, the distance adjusted to effect the properties of the film; and isolating a blown film therefrom.
    Type: Application
    Filed: August 24, 2018
    Publication date: May 9, 2019
    Inventors: Periagaram S. Ravishankar, Jianya Cheng, Adriana S. Silva, Wen Li, Abelhadi Sahnoune, Arturo Leyva, Alexander I. Norman
  • Patent number: 10253173
    Abstract: Provided herein are polymerization processes and polymer compositions including reactor blends formed by such polymerization processes. The polymerization processes include copolymerization using two metallocene catalyst systems: the first catalyst system capable of producing polymers having 60% or more vinyl terminations, the second catalyst system capable of producing high molecular weight polymers, preferably incorporating at least some of the polymers produced by the first catalyst system into the high molecular weight polymers. The reactor blends formed thereby therefore include first and second copolymer components, which may differ in monomer content and weight-average molecular weight (Mw). Furthermore, the reactor blends may exhibit advantageous rheological properties, at least some of which are consistent with long-chain branching. Preferred reactor blends comprise ethylene-propylene-diene (EPDM) terpolymers.
    Type: Grant
    Filed: December 28, 2015
    Date of Patent: April 9, 2019
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Jo Ann M. Canich, Rainer Kolb, Periagaram S. Ravishankar, Phillip T. Matsunaga, Peijun Jiang, Rhutesh K. Shah, Narayanaswami Dharmarajan
  • Patent number: 10124528
    Abstract: A method of forming a blown film comprising extruding a molten composition through a die opening to form a film; wherein the molten composition comprises at least one polyethylene and within the range from 0.10 wt % to 10 wt % of a cyclic-diene terpolymer by weight of the composition; causing the film to progress in a direction away from the die opening; cooling the film at a distance from the die opening, the distance adjusted to effect the properties of the film; and isolating a blown film therefrom.
    Type: Grant
    Filed: May 14, 2015
    Date of Patent: November 13, 2018
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Periagaram S. Ravishankar, Jianya Cheng, Adriana S. Silva, Wen Li, Abdelhadi Sahnoune, Arturo Leyva, Alexander I. Norman
  • Patent number: 10125247
    Abstract: A polyethylene composition including the product of the combination of at least one copolymer made from units derived from at least 85 wt % ethylene and a C3 to C10 ?-olefin and from 0.10 wt % to 10 wt % of a cyclic-diene terpolymer is provided.
    Type: Grant
    Filed: March 29, 2017
    Date of Patent: November 13, 2018
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Wen Li, Adriana S. Silva, Jianya Cheng, Periagaram S. Ravishankar
  • Publication number: 20180244869
    Abstract: A process for producing a thermoplastic vulcanizate, the process comprising: (i) charging a reactor with an oil-extended olefinic copolymer rubber, where the rubber is synthesized by a single-site catalyst, characterized by a multi-modal molecular weight distribution, and includes greater than 10 parts by weight extender oil per 100 parts by weight rubber; (ii) charging the reactor, contemporaneously or sequentially with respect to the rubber, with a thermoplastic resin, an oil, and a cure system to provide a pre-vulcanized mixture; and (iii) mixing the rubber, thermoplastic resin, oil, and cure system at a temperature above the melt temperature of the thermoplastic resin to thereby cause dynamic vulcanization of the rubber and produce the thermoplastic vulcanizate.
    Type: Application
    Filed: January 29, 2018
    Publication date: August 30, 2018
    Inventors: Oscar O. Chung, Periagaram S. Ravishankar, Porter C. Shannon, John P. Soisson
  • Patent number: 10047178
    Abstract: This disclosure relates to a process for polymerization, and in particular to minimizing undesired polymerization reactions downstream of a polymerization reaction zone, for instance by use of a quenching agent that enables fast reaction rates with active polymerization catalyst in the polymerization effluent, so as to quench the catalyst quickly, thereby preventing uncontrolled polymerization reactions. A preferred quenching agent is methanol. Also provided are means for treating polymer recycle streams containing oxygenates, which may result from the use of such quench agents, particularly in polymerization processes including polyene (e.g., diene) monomers.
    Type: Grant
    Filed: February 7, 2017
    Date of Patent: August 14, 2018
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Aaron H. Reed, Periagaram S. Ravishankar, Florin Barsan
  • Publication number: 20180002517
    Abstract: Provided herein are metallocene-catalyzed polymer compositions that exhibit advantageous rheological properties, at least some of which are consistent with long-chain branching, as well as polymerization processes suitable for forming such polymer compositions. The polymer compositions may have both LCB index measured at 125° C. of less than 5; and phase angle ? at complex shear modulus G*=100,000 Pa of less than about 54.5°, as determined at 125° C. The polymer compositions of particular embodiments are reactor blends, preferably of ethylene copolymers (e.g., ethylene-propylene (EP) copolymers and/or ethylene-propylene-diene (EPDM) terpolymers). The reactor blend may include first and second copolymer components, which may differ in monomer content and weight-average molecular weight (Mw).
    Type: Application
    Filed: December 28, 2015
    Publication date: January 4, 2018
    Inventors: Jo Ann M. Canich, Rainer Kolb, Periagaram S. Ravishankar, Phillip T. Matsunaga, Peijun Jiang, Rhutesh K. Shah, Narayanaswami Dharmarajan
  • Publication number: 20180002516
    Abstract: Provided herein are polymerization processes and polymer compositions including reactor blends formed by such polymerization processes. The polymerization processes include copolymerization using two metallocene catalyst systems: the first catalyst system capable of producing polymers having 60% or more vinyl terminations, the second catalyst system capable of producing high molecular weight polymers, preferably incorporating at least some of the polymers produced by the first catalyst system into the high molecular weight polymers. The reactor blends formed thereby therefore include first and second copolymer components, which may differ in monomer content and weight-average molecular weight (Mw). Furthermore, the reactor blends may exhibit advantageous rheological properties, at least some of which are consistent with long-chain branching. Preferred reactor blends comprise ethylene-propylene-diene (EPDM) terpolymers.
    Type: Application
    Filed: December 28, 2015
    Publication date: January 4, 2018
    Inventors: Jo Ann M. Canich, Rainer Kolb, Periagaram S. Ravishankar, Phillip T. Matsunaga, Peijun Jiang, Rhutesh K. Shah, Narayanaswami Dharmarajan
  • Publication number: 20170362350
    Abstract: Processes are provided which include copolymerization using one or both of a metallocene catalyst capable of producing high molecular weight polymers and a metallocene catalyst capable of producing polymers having 60% or more vinyl terminations. Polymerization processes include dual catalyst polymerization in a single polymerization zone comprising both metallocene catalysts. Other processes include serial or parallel polymerizations in multiple polymerization zones, using either or both catalysts in each polymerization zone. Such polymerization processes produce reactor blends, and are particularly suited for producing copolymer compositions (such as EP or EPDM copolymer compositions) exhibiting improved melt elasticity and rheological properties.
    Type: Application
    Filed: December 28, 2015
    Publication date: December 21, 2017
    Inventors: Jo Ann M. Canich, Rainer Kolb, Periagaram S. Ravishankar, Phillip T. Matsunaga, Peijun Jiang, Rhutesh K. Shah, Narayanaswami Dharmarajan
  • Patent number: 9796838
    Abstract: A blended multimodal polymer product is disclosed that comprises a first polymer, wherein the first polymer is a homopolymer of propylene or a propylene copolymer having an ethylene or a C4 to C10 olefin comonomer; and a second polymer, wherein the second polymer is a propylene homopolymer and a propylene copolymer having an ethylene or a C4 to C10 olefin comonomer, and wherein the first polymer and second polymer have a difference in heat of fusion of about 25 J/g or more. Methods for making such a polymer product using at least two reactors in parallel and for separating a propylene-based polymer from a solvent using a liquid-phase separator are also disclosed.
    Type: Grant
    Filed: January 8, 2016
    Date of Patent: October 24, 2017
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Periagaram S. Ravishankar, Yu Feng Wang, Luke P. Stephens, Florin Barsan, Douglas A. Berti
  • Publication number: 20170198124
    Abstract: A polyethylene composition including the product of the combination of at least one copolymer made from units derived from at least 85 wt % ethylene and a C3 to C10 ?-olefin and from 0.10 wt % to 10 wt % of a cyclic-diene terpolymer is provided.
    Type: Application
    Filed: March 29, 2017
    Publication date: July 13, 2017
    Inventors: Wen Li, Adriana S. Silva, Jianya Cheng, Periagaram S. Ravishankar
  • Publication number: 20170145129
    Abstract: This disclosure relates to a process for polymerization, and in particular to minimizing undesired polymerization reactions downstream of a polymerization reaction zone, for instance by use of a quenching agent that enables fast reaction rates with active polymerization catalyst in the polymerization effluent, so as to quench the catalyst quickly, thereby preventing uncontrolled polymerization reactions. A preferred quenching agent is methanol. Also provided are means for treating polymer recycle streams containing oxygenates, which may result from the use of such quench agents, particularly in polymerization processes including polyene (e.g., diene) monomers.
    Type: Application
    Filed: February 7, 2017
    Publication date: May 25, 2017
    Inventors: Aaron H. Reed, Periagaram S. Ravishankar, Florin Barsan