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: 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
  • Publication number: 20170028605
    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: May 14, 2015
    Publication date: February 2, 2017
    Inventors: Periagaram S. Ravishankar, Jianya Cheng, Adriana S. Silva, Wen Li, Abdelhadi Sahnoune, Arturo Leyva, Alexander I. Norman
  • Patent number: 9382344
    Abstract: This disclosure relates to a process for polymerization comprising providing a recycle stream, wherein the recycle stream comprises one or more C6 to C12 conjugated or non-conjugated diene monomers and one or more C1 to C40 oxygenates. The recycle stream is contacted with an adsorbent bed to produce a treated recycle stream; wherein the adsorbent bed comprises at least two adsorbents to remove quenching agent and C1 to C40 oxygenates.
    Type: Grant
    Filed: June 20, 2014
    Date of Patent: July 5, 2016
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Suzzy C. Ho, Jo Ann M. Canich, Machteld M. Mertens, Periagaram S. Ravishankar, Patrick S. Byrne, Lisa B. V. Stefaniak
  • Publication number: 20160115306
    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: Application
    Filed: January 8, 2016
    Publication date: April 28, 2016
    Inventors: Periagaram S. Ravishankar, Yu Feng Wang, Luke P. Stephens, Florin Barsan, Douglas A. Berti
  • Patent number: 9260635
    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: February 28, 2013
    Date of Patent: February 16, 2016
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Periagaram S. Ravishankar, Yu Feng Wang, Luke P. Stephens, Florin Barsan, Douglas A. Berti
  • Patent number: 9234093
    Abstract: A process for preparing a thermoplastic vulcanizate, the process comprising: charging a reactor with an olefinic copolymer rubber, where the olefinic copolymer rubber is characterized by a multimodal molecular weight, an average branching index of greater than 0.8, includes less than 10 parts by weight oil per 100 parts by weight rubber, includes less than 1 parts by weight non-rubber particulate, per 100 parts by weight rubber, and is in the form of granules having a particle size less than 8 mm; charging the reactor, contemporaneously or sequentially with respect to the rubber, with a thermoplastic resin, an oil, and a cure system; melt mixing the rubber, the thermoplastic resin, the oil, and the cure system; and dynamically vulcanizing the rubber.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: January 12, 2016
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Maria Dolores Ellul, Periagaram S. Ravishankar, Paul E. McDaniel
  • Patent number: 9227886
    Abstract: The present invention relates to a polymerization process of producing ethylene-alpha-olefin polymer. The polymerization process comprises supplying at a feed temperature a feed containing ethylene, at least one alpha-olefin and optionally, a diene in a solvent, the solvent is supplied at a solvent feed rate; supplying at a catalyst feed rate a catalyst to a reactor, and contacting the feed with the catalyst to produce a reaction mixture containing the polymer. The present invention also relates to processes for improving the energy utilization of polymerization processes, wherein the process comprises decreasing the feed temperature, decreasing the solvent feed rate, and decreasing the catalyst feed rate.
    Type: Grant
    Filed: October 12, 2012
    Date of Patent: January 5, 2016
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Periagaram S. Ravishankar, Aaron H. Reed
  • Publication number: 20150290616
    Abstract: Provided are processes and apparatuses for continuous solution polymerization which can mitigate fouling during the production of propylene-based polymers.
    Type: Application
    Filed: November 13, 2014
    Publication date: October 15, 2015
    Inventors: Quintin P. Costin, Periagaram S. Ravishankar
  • Patent number: 9139794
    Abstract: Provided are processes for making polymer compositions, especially those with reduced or no gel formation in lubricating oils as identified by rheological and visual gel tests and which are useful as viscosity modifiers. The processes described herein aim to achieve this objective by adjusting the concentrations of the hydrogen feed(s) in the first and/or second polymerization reaction zones, preferably such that (a) the hydrogen feed concentration in the first polymerization reaction zone is 0.0-1.0 wt %, based on total weight of feed(s) of hydrogen, ethylene monomer, ?-olefin comonomer, and solvent into the first polymerization reaction zone, and/or (b) the hydrogen feed concentration in the second polymerization reaction zone is 0.0-0.5 wt %, based on total weight of feed(s) of hydrogen, ethylene monomer, ?-olefin comonomer, and solvent into the second polymerization reaction zone.
    Type: Grant
    Filed: February 3, 2012
    Date of Patent: September 22, 2015
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Rainer Kolb, Phillip T. Matsunaga, Periagaram S. Ravishankar, Lisa B. Stefaniak, Quintin Paul Ward Costin
  • Patent number: 8969481
    Abstract: Thermoplastic elastomer compositions and methods for making same. The elastomer composition can include at least one partially cured rubber component that is an ethylene-alpha-olefin-vinyl norbornene elastomeric polymer, and at least one thermoplastic component. The rubber component is at least partially cured using a peroxide curative in an amount effective to yield a cure level of the rubber component of at least 85%. The rubber component has a molecular weight distribution (MWD) less than 6, and a branching index greater than 0.60.
    Type: Grant
    Filed: November 5, 2009
    Date of Patent: March 3, 2015
    Assignee: ExxonMobil Chemical Patent Inc.
    Inventors: Maria D. Ellul, Periagaram S. Ravishankar
  • Patent number: 8962762
    Abstract: Provided are thermoplastic polymer compositions having a single melting point, articles made therefrom, and methods for elevating the melting point of low melting point polymers. Thermoplastic polymer compositions are composed of one or more high melting point polyolefins and a thermoplastic component that includes a low melting point polypropylene. High melting point polyolefins are composed of a stereoregular polypropylene having a tacticity similar to the low melting point polypropylene. The low melting point polypropylene includes, for example, propylene homopolymers and copolymers composed of propylene and one or more comonomers. Thermoplastic polymer compositions may also optionally contain any of the various additives commonly used in such polymer compositions, such as for example oils, etc. In one embodiment, thermoplastic polymer compositions are thermoplastic elastomer compositions that include an elastomeric component composed of an elastomer or rubber.
    Type: Grant
    Filed: April 14, 2008
    Date of Patent: February 24, 2015
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Periagaram S. Ravishankar, Maria D. Ellul
  • Publication number: 20150045513
    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: Application
    Filed: February 28, 2013
    Publication date: February 12, 2015
    Inventors: Periagaram S. Ravishankar, Yu Feng Wang, Luke P. Stephens, Florin Barsan, Douglas A. Berti
  • Publication number: 20150031831
    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: Application
    Filed: October 9, 2014
    Publication date: January 29, 2015
    Inventor: Periagaram S. Ravishankar
  • Publication number: 20140378732
    Abstract: This disclosure relates to a process for polymerization comprising providing a recycle stream, wherein the recycle stream comprises one or more C6 to C12 conjugated or non-conjugated diene monomers and one or more C1 to C40 oxygenates. The recycle stream is contacted with an adsorbent bed to produce a treated recycle stream; wherein the adsorbent bed comprises at least two adsorbents to remove quenching agent and C1 to C40 oxygenates.
    Type: Application
    Filed: June 20, 2014
    Publication date: December 25, 2014
    Inventors: Suzzy C. Ho, Jo Ann M. Canich, Machteld M. Mertens, Periagaram S. Ravishankar, Patrick S. Byrne, Lisa B. V. Stefaniak