IN2012DN02583A - - Google Patents

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Publication number
IN2012DN02583A
IN2012DN02583A IN2583DEN2012A IN2012DN02583A IN 2012DN02583 A IN2012DN02583 A IN 2012DN02583A IN 2583DEN2012 A IN2583DEN2012 A IN 2583DEN2012A IN 2012DN02583 A IN2012DN02583 A IN 2012DN02583A
Authority
IN
India
Prior art keywords
catalyst
aid agent
transition aid
alkoxylated
cocatalyst
Prior art date
Application number
Inventor
Gregory Goode Mark
Joseph Cann Kevin
David Hussein Fathi
Lynn Santana Robert
C Schutz David
Kyriacos Agapiou Agapios
Original Assignee
Univation Tech Llc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Univation Tech Llc filed Critical Univation Tech Llc
Publication of IN2012DN02583A publication Critical patent/IN2012DN02583A/en

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Classifications

    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F10/00Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
    • C08F10/02Ethene
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00Processes of polymerisation
    • C08F2/34Polymerisation in gaseous state
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F10/00Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00Processes of polymerisation
    • C08F2/38Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation
    • C08F2/42Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation using short-stopping agents
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F210/00Copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
    • C08F210/16Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2410/00Features related to the catalyst preparation, the catalyst use or to the deactivation of the catalyst
    • C08F2410/05Transitioning, i.e. transition from one catalyst to another with use of a deactivating agent
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S526/00Synthetic resins or natural rubbers -- part of the class 520 series
    • Y10S526/901Monomer polymerized in vapor state in presence of transition metal containing catalyst

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
  • Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
  • Polymerisation Methods In General (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

A method of transitioning from a first catalyst to a second catalyst in an olefin polymerization reactor, comprising: adding a transition aid agent, wherein said transition aid agent is selected from one of alkoxylated amines, alkoxylated amides, or combinations thereof, wherein said first catalyst comprises at least one Ziegler-Natta catalyst comprising said catalyst, a cocatalyst and optionally a support, and said second catalyst comprises at least one chromium based catalyst.
IN2583DEN2012 2004-12-21 2005-12-21 IN2012DN02583A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US63782904P 2004-12-21 2004-12-21
US11/312,272 US7629422B2 (en) 2004-12-21 2005-12-20 Process for transitioning between Ziegler-Natta-based and chromium-based catalysts
PCT/US2005/046498 WO2006069204A2 (en) 2004-12-21 2005-12-21 Process for transitioning between ziegler-natta-based and chromium-based catalysts

Publications (1)

Publication Number Publication Date
IN2012DN02583A true IN2012DN02583A (en) 2015-08-28

Family

ID=36190409

Family Applications (1)

Application Number Title Priority Date Filing Date
IN2583DEN2012 IN2012DN02583A (en) 2004-12-21 2005-12-21

Country Status (14)

Country Link
US (1) US7629422B2 (en)
EP (2) EP2174961B1 (en)
JP (1) JP2008524430A (en)
KR (1) KR20070093066A (en)
AT (1) ATE484526T1 (en)
AU (1) AU2005319178A1 (en)
BR (2) BR122016016170B1 (en)
CA (1) CA2587621A1 (en)
DE (1) DE602005024174D1 (en)
ES (1) ES2537339T3 (en)
IN (1) IN2012DN02583A (en)
MX (1) MX2007007454A (en)
RU (1) RU2358985C2 (en)
WO (1) WO2006069204A2 (en)

Families Citing this family (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7657923B2 (en) * 2004-07-23 2010-02-02 Microsoft Corporation Framework for a security system
WO2006130310A1 (en) * 2005-05-27 2006-12-07 Union Carbide Chemicals & Plastics Technology Corporation Process for transitioning a reactor from a ziegler-natta catalyzed polymerization to a polymerization catalyzed by another type of catalyst system
DE102005056775A1 (en) * 2005-11-28 2007-05-31 Basell Polyolefine Gmbh Procedure for catalyst change in a gas phase reactor comprises terminating the polymerization with first catalyst, rinsing the reactor with deactivating agent, providing second catalyst and continuing polymerization
CA2529920C (en) * 2005-12-13 2013-08-20 Nova Chemicals Corporation On the fly catalyst transitions
WO2008008169A2 (en) * 2006-07-07 2008-01-17 Univation Technologies, Llc Using electrical probes for detecting impurities in reactor systems
CN101965371B (en) * 2007-12-31 2015-09-23 陶氏环球技术有限责任公司 For being polymerized the method for the polymkeric substance based on alkene
PT2145923E (en) * 2008-07-16 2011-07-01 Borealis Ag Heterophasic polymer composition of high stiffness
WO2010009860A1 (en) 2008-07-23 2010-01-28 Basell Polyolefine Gmbh Method for transitioning between incompatible olefin polymerization catalyst systems
RU2510703C2 (en) * 2008-12-23 2014-04-10 Базелль Полиолефине Гмбх Method of transition between non-compatible systems of olefin polymerisation catalysts
KR101698618B1 (en) * 2009-01-08 2017-01-20 유니베이션 테크놀로지즈, 엘엘씨 Additive for polyolefin polymerization processes
BR112012014859B1 (en) * 2009-12-18 2020-04-28 Total Petrochemicals Res Feluy method to optimize the sequential use of at least two ethylene polymerization catalysts in a circulation reactor for ethylene polymerization, their use
EP2536767B1 (en) * 2010-02-18 2015-05-06 Univation Technologies, LLC Methods for operating a polymerization reactor
EP2383298A1 (en) * 2010-04-30 2011-11-02 Ineos Europe Limited Polymerization process
EP2383301A1 (en) 2010-04-30 2011-11-02 Ineos Europe Limited Polymerization process
WO2012067777A2 (en) * 2010-11-19 2012-05-24 Exxonmobil Chemical Patents Inc. Processes for making multimodal molecular weight distribution polyolefins
US8148470B1 (en) 2010-11-19 2012-04-03 Exxonmobil Chemical Patents Inc. Processes for making multimodal molecular weight distribution polyolefins
CA2740755C (en) 2011-05-25 2019-01-15 Nova Chemicals Corporation Chromium catalysts for olefin polymerization
CN103772544B (en) * 2012-10-20 2016-06-15 中国石油化工股份有限公司 Gas-phase polyethylene titanium system and chromium-based catalysts switching technique
IN2015DN02467A (en) 2012-11-01 2015-09-04 Univation Tech Llc
CN111454383A (en) * 2014-04-02 2020-07-28 尤尼威蒂恩技术有限责任公司 Catalyst composition, preparation method and use in polymerization process
US9944727B2 (en) 2014-12-22 2018-04-17 Sabic Global Technologies B.V. Process for transitioning between incompatible catalysts
KR20170109548A (en) 2014-12-22 2017-09-29 사빅 글로벌 테크놀러지스 비.브이. Method for converting between non-fusable catalysts
CN107531841B (en) 2015-03-24 2021-02-09 Sabic环球技术有限责任公司 Process for transitioning between incompatible catalysts
RU2736067C2 (en) 2016-04-20 2020-11-11 ЮНИВЕЙШН ТЕКНОЛОДЖИЗ, ЭлЭлСи Polymer fluidity index modifier
US10450392B2 (en) 2016-07-29 2019-10-22 Exxonmobil Chemical Patents Inc. Polymerization processes using high molecular weight polyhydric quenching agents
CN109937213B (en) 2016-09-08 2021-03-02 Sabic环球技术有限责任公司 Process for preparing polyolefins by discontinuous addition of thermal runaway reducers
US10023666B2 (en) 2016-12-13 2018-07-17 Chevron Phillips Chemical Company Lp Process for transitioning between low percentage chrome and high percentage chrome catalysts
CA3079148A1 (en) 2017-10-27 2019-05-02 Univation Technologies, Llc Polyethylene copolymer resins and films
EP3700946B1 (en) * 2017-10-27 2021-09-08 Univation Technologies, LLC Selectively transitioning polymerization processes
US11046793B2 (en) 2018-02-22 2021-06-29 Exxonmobil Chemical Patents Inc. Silica quenching agents for use in polymerization process
CN114621378B (en) * 2020-12-11 2023-11-28 中国石油天然气股份有限公司 Switching method between different catalysts of gas-phase polyethylene chromium series

Family Cites Families (56)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3321550A (en) 1960-07-14 1967-05-23 Union Carbide Corp Curable compositions of a vinyl chloride polymer and a polyepoxide containing at least two epoxycyclohexyl groups
US5066737A (en) 1990-10-22 1991-11-19 Shell Oil Company Olefin polymerization catalyst
US3221002A (en) 1963-09-26 1965-11-30 Cabot Corp Process for polymerization utilizing a surface treated inorganic solid catalyst
US3242090A (en) 1964-03-10 1966-03-22 Macdermid Inc Compositions for and methods of removing gold deposits by chemical action
US3487112A (en) 1967-04-27 1969-12-30 Monsanto Co Vapor phase hydroformylation process
GB1360389A (en) 1970-09-07 1974-07-17 Ici Ltd Synthetic resins derived from petroleum
US3687920A (en) 1971-01-25 1972-08-29 Union Carbide Corp Polymerization of olefins with silane modified catalyst system
US3709853A (en) 1971-04-29 1973-01-09 Union Carbide Corp Polymerization of ethylene using supported bis-(cyclopentadienyl)chromium(ii)catalysts
US4115639A (en) 1971-06-24 1978-09-19 Union Carbide Corporation Ethylene polymerization with ether modified catalyst
US4086408A (en) 1973-12-20 1978-04-25 Union Carbide Corporation Ethylene polymerization with silane modified catalyst
IT1037112B (en) 1975-03-28 1979-11-10 Montedison Spa CATALYSTS FOR THE POLYMERIZATION OF OLFINES
US4077904A (en) 1976-06-29 1978-03-07 Union Carbide Corporation Olefin polymerization process and catalyst therefor
US4101445A (en) 1976-09-22 1978-07-18 Union Carbide Corporation Preparation of modified and activated chromocene catalysts for ethylene polymerization
US4100105A (en) 1977-01-21 1978-07-11 Union Carbide Corporation Titanium-modified silyl chromate catalysts for ethylene polymerization
DE2731067C3 (en) 1977-07-09 1981-11-26 Bunawerke Hüls GmbH, 4370 Marl Process for the preparation of polybutadiene with a high content of monomer units in a cis-1,4 structure
US4302566A (en) 1978-03-31 1981-11-24 Union Carbide Corporation Preparation of ethylene copolymers in fluid bed reactor
US4302565A (en) 1978-03-31 1981-11-24 Union Carbide Corporation Impregnated polymerization catalyst, process for preparing, and use for ethylene copolymerization
FR2437225A1 (en) 1978-09-28 1980-04-25 Bekaert Sa Nv ADVANCED SKIING
US4482687A (en) 1979-10-26 1984-11-13 Union Carbide Corporation Preparation of low-density ethylene copolymers in fluid bed reactor
US4376062A (en) 1979-11-28 1983-03-08 Union Carbide Corporation Spheroidal polymerization catalyst, process for preparing, and use for ethylene polymerization
US5019633A (en) 1980-12-24 1991-05-28 Technology Corporation Catalyst composition for polymerizing ethylene
US4379758A (en) 1980-12-24 1983-04-12 Union Carbide Corporation Catalyst composition for polymerizing ethylene
CA1174800A (en) 1981-08-24 1984-09-18 Charles Cozewith Gas phase method for producing copolymers of ethylene and higher alpha-olefins
US4376191A (en) 1981-10-01 1983-03-08 Union Carbide Corporation Use of dialkylzinc compounds to initiate polymerization of ethylene with chromium oxide catalysts
CA1219994A (en) 1981-12-24 1987-03-31 Nobunori Maehara Process for producing polybutadiene rubber with enhanced mechanical strength
DE3366573D1 (en) 1982-06-24 1986-11-06 Bp Chimie Sa Process for the polymerization and copolymerization of alpha-olefins in a fluidized bed
US4460755A (en) * 1982-09-30 1984-07-17 Union Carbide Corporation Direct conversion of a polymerization reaction catalyzed by a Ziegler-type catalyst into one catalyzed by a chromium-based catalyst
JPS5964604A (en) 1982-10-06 1984-04-12 Sumitomo Chem Co Ltd Production of polyolefin
US4560671A (en) 1983-07-01 1985-12-24 Union Carbide Corporation Olefin polymerization catalysts adapted for gas phase processes
US4547555A (en) * 1983-09-01 1985-10-15 Mobil Oil Corporation Method for rapid kill gas injection to gas phase polymerization reactors during power failures
FR2555182B1 (en) 1983-11-23 1986-11-07 Bp Chimie Sa PROCESS FOR THE PREPARATION OF A SUPPORTED CATALYST FOR THE COPOLYMERIZATION OF ETHYLENE WITH SUPERIOR ALPHA-OLEFINS
US4755495A (en) 1986-02-27 1988-07-05 Union Carbide Corporation Process for activation of titanium and vanadium catalysts useful in ethylene polymerization
JPH075663B2 (en) 1986-04-01 1995-01-25 三井東圧化学株式会社 Method for polymerizing ethylene or α-olefin
US4689437A (en) 1986-07-21 1987-08-25 Union Carbide Corporation Oligomerization to alpha-olefins
US4719193A (en) 1986-09-30 1988-01-12 Union Carbide Corporation Processes for preparing polyethylene catalysts by heating catalyst precursors
FR2609036B1 (en) 1986-12-29 1989-04-14 Bp Chimie Sa POLYMERIZATION OR COPOLYMERIZATION OF ETHYLENE IN THE GASEOUS PHASE IN THE PRESENCE OF A PREPOLYMER COMPRISING A CHROMIUM OXIDE CATALYST
US5055438A (en) 1989-09-13 1991-10-08 Exxon Chemical Patents, Inc. Olefin polymerization catalysts
US5093415A (en) 1987-05-19 1992-03-03 Union Carbide Chemicals & Plastics Technology Corporation Process for producing stereoregular polymers having a narrow molecular weight distribution
FR2628110B1 (en) 1988-03-03 1994-03-25 Bp Chimie CATALYST FOR POLYMERIZATION OF ZIEGLER-NATTA-TYPE OLEFINS, SUPPORTED ON SPHERICAL MAGNESIUM CHLORIDE PARTICLES, AND PROCESS FOR PREPARING THE SAME
US5376612A (en) 1989-08-10 1994-12-27 Phillips Petroleum Company Chromium catalysts and process for making chromium catalysts
NZ235032A (en) 1989-08-31 1993-04-28 Dow Chemical Co Constrained geometry complexes of titanium, zirconium or hafnium comprising a substituted cyclopentadiene ligand; use as olefin polymerisation catalyst component
US5070055A (en) 1990-06-29 1991-12-03 Union Carbide Chemicals And Plastics Technology Corporation Novel coimpregnated vanadium-zirconium catalyst for making polyethylene with broad or bimodal MW distribution
US5317036A (en) 1992-10-16 1994-05-31 Union Carbide Chemicals & Plastics Technology Corporation Gas phase polymerization reactions utilizing soluble unsupported catalysts
US5391657A (en) * 1993-09-27 1995-02-21 Union Carbide Chemicals & Plastics Technology Corporaton Method for reducing sheeting and static charges during polymerization of ethylene polymers
US5670438A (en) 1993-10-27 1997-09-23 Phillips Petroleum Company Catalyst compositions and catalytic processes
US5442019A (en) 1994-03-25 1995-08-15 Exxon Chemical Company Process for transitioning between incompatible polymerization catalysts
IT1270125B (en) * 1994-10-05 1997-04-28 Spherilene Srl PROCESS FOR THE (CO) POLYMERIZATION OF OLEFINE
US5672666A (en) * 1995-06-05 1997-09-30 Exxon Chemical Patents Inc. Process for transitioning between incompatible polymerization catalysts
JPH0995509A (en) 1995-09-30 1997-04-08 Nippon Petrochem Co Ltd Method for changing catalyst in steady vapor phase polymerization of olefin
EP0768322A1 (en) 1995-10-16 1997-04-16 Sumitomo Chemical Company, Limited Method for preparing catalyst component for olefin polymerization, catalyst for olefin polymerization and process for producing olefin polymer with the catalyst
US5869585A (en) 1995-10-30 1999-02-09 Mobil Oil Corporation Multi-component catalyst systems for olefin polymerization
NO301331B1 (en) * 1996-03-05 1997-10-13 Borealis As Process for changing catalyst by suspension polymerization of olefins
US5849655A (en) 1996-12-20 1998-12-15 Fina Technology, Inc. Polyolefin catalyst for polymerization of propylene and a method of making and using thereof
US6187866B1 (en) 1999-06-04 2001-02-13 Union Carbide Chemicals & Plastics Technology Corporation Staged reactor process
US6858684B2 (en) * 2002-12-30 2005-02-22 Univation Technologies, Llc Processes for transitioning between various polymerization catalysts
US6949612B2 (en) * 2002-12-31 2005-09-27 Univation Technologies, Llc Processes for transitioning between metallocene and Ziegler-Natta polymerization catalysts

Also Published As

Publication number Publication date
WO2006069204A2 (en) 2006-06-29
DE602005024174D1 (en) 2010-11-25
ES2537339T3 (en) 2015-06-05
US7629422B2 (en) 2009-12-08
RU2007128006A (en) 2009-01-27
BRPI0519173B1 (en) 2016-08-30
RU2358985C2 (en) 2009-06-20
EP1833854A2 (en) 2007-09-19
EP2174961A2 (en) 2010-04-14
US20060160965A1 (en) 2006-07-20
ATE484526T1 (en) 2010-10-15
EP2174961A3 (en) 2010-07-28
JP2008524430A (en) 2008-07-10
BRPI0519173A2 (en) 2008-12-30
BR122016016170B1 (en) 2017-04-11
WO2006069204A3 (en) 2006-09-14
EP1833854B1 (en) 2010-10-13
AU2005319178A1 (en) 2006-06-29
MX2007007454A (en) 2007-11-21
KR20070093066A (en) 2007-09-17
CA2587621A1 (en) 2006-09-29
EP2174961B1 (en) 2015-03-25

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