AU641291B2 - Bulk polymerization using specific metallocene catalysts for the preparation of cycloolefin polymers - Google Patents

Bulk polymerization using specific metallocene catalysts for the preparation of cycloolefin polymers

Info

Publication number
AU641291B2
AU641291B2 AU87777/91A AU8777791A AU641291B2 AU 641291 B2 AU641291 B2 AU 641291B2 AU 87777/91 A AU87777/91 A AU 87777/91A AU 8777791 A AU8777791 A AU 8777791A AU 641291 B2 AU641291 B2 AU 641291B2
Authority
AU
Australia
Prior art keywords
preparation
bulk polymerization
metallocene catalysts
cycloolefin polymers
specific metallocene
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
AU87777/91A
Other languages
English (en)
Other versions
AU8777791A (en
Inventor
Martin Antberg
Michael-Joachim Brekner
Frank Osan
Jurgen Rohrmann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hoechst AG
Original Assignee
Hoechst AG
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 Hoechst AG filed Critical Hoechst AG
Publication of AU8777791A publication Critical patent/AU8777791A/en
Application granted granted Critical
Publication of AU641291B2 publication Critical patent/AU641291B2/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F4/00—Polymerisation catalysts
    • C08F4/42—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors
    • C08F4/44—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides
    • C08F4/60—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides together with refractory metals, iron group metals, platinum group metals, manganese, rhenium technetium or compounds thereof
    • C08F4/602—Component covered by group C08F4/60 with an organo-aluminium compound
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F32/00—Homopolymers and copolymers of cyclic compounds having no unsaturated aliphatic radicals in a side chain, and having one or more carbon-to-carbon double bonds in a carbocyclic ring system
    • C08F32/08—Homopolymers and copolymers of cyclic compounds having no unsaturated aliphatic radicals in a side chain, and having one or more carbon-to-carbon double bonds in a carbocyclic ring system having two condensed rings

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
  • Polyoxymethylene Polymers And Polymers With Carbon-To-Carbon Bonds (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
AU87777/91A 1990-11-14 1991-11-13 Bulk polymerization using specific metallocene catalysts for the preparation of cycloolefin polymers Ceased AU641291B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4036264 1990-11-14
DE4036264 1990-11-14

Publications (2)

Publication Number Publication Date
AU8777791A AU8777791A (en) 1992-05-21
AU641291B2 true AU641291B2 (en) 1993-09-16

Family

ID=6418254

Family Applications (1)

Application Number Title Priority Date Filing Date
AU87777/91A Ceased AU641291B2 (en) 1990-11-14 1991-11-13 Bulk polymerization using specific metallocene catalysts for the preparation of cycloolefin polymers

Country Status (13)

Country Link
EP (1) EP0485893B1 (enrdf_load_stackoverflow)
JP (1) JP3247130B2 (enrdf_load_stackoverflow)
KR (1) KR100230915B1 (enrdf_load_stackoverflow)
AT (1) ATE165372T1 (enrdf_load_stackoverflow)
AU (1) AU641291B2 (enrdf_load_stackoverflow)
CA (1) CA2055397C (enrdf_load_stackoverflow)
CS (1) CS344291A3 (enrdf_load_stackoverflow)
DE (1) DE59108971D1 (enrdf_load_stackoverflow)
ES (1) ES2117632T3 (enrdf_load_stackoverflow)
HU (1) HUT59429A (enrdf_load_stackoverflow)
NO (1) NO914439L (enrdf_load_stackoverflow)
TW (1) TW227005B (enrdf_load_stackoverflow)
ZA (1) ZA918990B (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU649520B2 (en) * 1991-02-27 1994-05-26 Hoechst Aktiengesellschaft Cycloolefin (co)polymers with a narrow molecular weight distribution and a process for the preparation thereof

Families Citing this family (72)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5744664A (en) * 1990-07-05 1998-04-28 Hoechst Aktiengesellschaft Cycloolefin copolymers (COCS) as substrate material for liquid-crystal displays
EP0594147A1 (de) * 1992-10-24 1994-04-27 Hoechst Aktiengesellschaft Cycloolefin-Copolymerisate (COC) als Substratmaterial für Flüssigkristalldisplays
DE4304285A1 (de) * 1993-02-12 1994-08-18 Hoechst Ag Cycloolefincopolymere mit hoher Reißfestigkeit und niedriger optischer Dämpfung
DE59402624D1 (de) * 1993-02-12 1997-06-12 Hoechst Ag Verfahren zur Herstellung von Cycloolefincopolymeren
EP0610850A1 (de) * 1993-02-12 1994-08-17 Hoechst Aktiengesellschaft Verfahren zur Herstellung von Cycloolefinpolymeren
US6214951B1 (en) 1993-02-12 2001-04-10 Hoechst Aktiengesellschaft Cycloolefin copolymers having high tear strength and low optical attenuation
TW369545B (en) * 1993-02-12 1999-09-11 Hoechst Ag Process for preparing cycloolefin copolymers
EP0610843B1 (de) * 1993-02-12 1999-05-19 Ticona GmbH Verfahren zur Herstellung von Cycloolefinpolymeren
TW274100B (enrdf_load_stackoverflow) 1993-02-12 1996-04-11 Hoechst Ag
DE4304308A1 (de) * 1993-02-12 1994-08-18 Hoechst Ag Steife Cycloolefincopolymer-Folie
DE4304291A1 (de) * 1993-02-12 1994-08-18 Hoechst Ag Cycloolefincopolymere mit niedriger Schmelzeviskosität und niedriger optischer Dämpfung
DE4304309A1 (de) * 1993-02-12 1994-08-18 Hoechst Ag Biegsame Cycloolefincopolymer-Folie
DE4410559A1 (de) * 1994-03-26 1995-09-28 Hoechst Ag Orientierte Polyolefinfolie mit amorphem Polymer, Verfahren zu ihrer Herstellung und ihre Verwendung
DE4422157A1 (de) * 1994-06-24 1996-01-04 Hoechst Ag Verfahren zur Herstellung von Cycloolefincopolymeren
DE4426185A1 (de) 1994-07-23 1996-01-25 Hoechst Ag Siegelfähige orientierte Polyolefin-Mehrschichtfolie, Verfahren zu ihrer Herstellung und ihre Verwendung
DE4426184A1 (de) 1994-07-23 1996-01-25 Hoechst Ag Nicht siegelfähige orientierte Polyolefin-Mehrschichtfolie, Verfahren zu ihrer Herstellung und ihre Verwendung
DE19536043A1 (de) * 1995-09-28 1997-04-10 Hoechst Ag Polyolefinfolie mit Cycloolefinpolymer, Verfahren zu ihrer Herstellung und ihre Verwendung
DE19539093A1 (de) 1995-10-20 1997-04-24 Hoechst Ag Metallisierte Polyolefinfolie
DE19917790A1 (de) * 1999-04-20 2000-11-02 Hoechst Trespaphan Gmbh Biaxial orientierte Folie für die Herstellung von Keramikkondensatoren
DE19929809A1 (de) 1999-06-30 2001-01-04 Ticona Gmbh Kontinuierliches Verfahren zur Herstellung eines amorphen Polyolefins mit breiter Molmassenverteilung und einheitlicher Glastemperatur
DE10009646A1 (de) 2000-03-01 2001-09-13 Ticona Gmbh Neues Polymergemisch
DE10012137A1 (de) 2000-03-13 2001-09-20 Mitsubishi Polyester Film Gmbh Biaxial orientierte Polyesterfolie enthaltend ein Cycloolefincopolymer, Verfahren zu ihrer Herstellung und ihre Verwendung
DE10022942A1 (de) 2000-05-11 2001-11-15 Mitsubishi Polyester Film Gmbh Weisse, zumindest einseitig matte, biaxial orientierte Polyesterfolie mit Cycloolefincopolymer, Verfahren zu ihrer Herstellung und ihre Verwendung
DE10026177A1 (de) 2000-05-26 2001-11-29 Mitsubishi Polyester Film Gmbh Weiße, hochglänzende Polyesterfolie enthaltend Cycloolefincopolymer (COC), Verfahren zu ihrer Herstellung und ihre Verwendung
DE10035328A1 (de) 2000-07-20 2002-01-31 Mitsubishi Polyester Film Gmbh Opake Polyesterfolie enthaltend Cycloolefincopolymer (COC) mit guter Oberflächenhaftung, Verfahren zu ihrer Herstellung und ihre Verwendung
US6696524B2 (en) 2001-02-20 2004-02-24 E. I. Du Pont De Nemours And Company Low Tg ethylene-based polymer, cycloolefin polymer blends
US6670423B2 (en) 2001-02-20 2003-12-30 E. I. Du Pont De Nemours And Company Polar ethylene-based polymer, cycloolefin polymer blends
DE10137924B4 (de) 2001-08-07 2005-12-01 Ticona Gmbh Langfaserverstärkte Polyolefin-Kunststoff Struktur, Verfahren zu seiner Herstellung und daraus hergestellte Formkörper
US6713582B2 (en) 2001-12-14 2004-03-30 Uniroyal Chemical Company, Inc. Process for the oligomerization of α-olefins having low unsaturation, the resulting polymers, and lubricants containing same
WO2003055678A1 (en) * 2001-12-21 2003-07-10 E.I. Du Pont De Nemours And Company Multilayer film
DE10223663A1 (de) 2002-05-28 2003-12-11 Mitsubishi Polyester Film Gmbh Transparente Polyesterfolie mit verbesserter Wasserdampfbarriere, Verfahren zu ihrer Herstellung und ihre Verwendung
DE10223662A1 (de) 2002-05-28 2003-12-11 Mitsubishi Polyester Film Gmbh Transparente Polyesterfolie mit verbesserter Wasserdampfbarriere, Verfahren zu ihrer Herstellung und ihre Verwendung
DE10242730A1 (de) 2002-09-13 2004-03-25 Ticona Gmbh Thermoformbare Folie mit hoher Wärmeformbeständigkeit und Wasserdampfbarriere
US7223459B2 (en) 2003-04-22 2007-05-29 Mitsubishi Polyester Film Gmbh Coextruded, hot-sealable and peelable polyester film, process for its production and its use
US7442427B2 (en) 2003-04-22 2008-10-28 Mitsubishi Polyester Film Gmbh Coextruded, hot-sealable and peelable polyester film, process for its production and its use
US7288312B2 (en) 2003-04-22 2007-10-30 Mitsubishi Polyester Film Gmbh Coextruded, hot-sealable and peelable polyester film having low peeling resistance, process for its production and its use
US7144615B2 (en) 2003-04-22 2006-12-05 Mitsubishi Polyester Film Gmbh Coextruded, hot-sealable and peelable polyester film, process for its production and its use
US7141293B2 (en) 2003-04-22 2006-11-28 Mitsubishi Polyester Film Gmbh Coextruded, hot-sealable and peelable polyester film having high peeling resistance, process for its production and its use
US7186452B2 (en) 2003-04-22 2007-03-06 Mitsubishi Polyester Film Gmbh Coextruded, hot-sealable and peelable polyester film having high peeling resistance, process for its production and its use
DE10352432A1 (de) 2003-11-10 2005-06-09 Mitsubishi Polyester Film Gmbh Weiße, heißsiegelbare, peelfähige Polyesterfolie, Verfahren zu ihrer Herstellung und ihre Verwendung
DE10352444A1 (de) 2003-11-10 2005-06-09 Mitsubishi Polyester Film Gmbh Haftvermittelte, heißsiegelbare und peelfähige Polyesterfolie, Verfahren zu ihrer Herstellung und ihre Verwendung
DE10352430A1 (de) 2003-11-10 2005-06-09 Mitsubishi Polyester Film Gmbh Peelfähige Polyesterfolie mit verbesserter Sauerstoffbarriere, Verfahren zu ihrer Herstellung und ihre Verwendung
DE10352431A1 (de) 2003-11-10 2005-06-09 Mitsubishi Polyester Film Gmbh Peelfähige Polyesterfolie mit selbsttätiger Entlüftung, Verfahren zu ihrer Herstellung und ihre Verwendung
US7288316B2 (en) 2003-11-21 2007-10-30 Topas Advanced Polymers, Inc. Cycloolefin copolymer heat sealable films
JP2004195246A (ja) * 2004-02-13 2004-07-15 Mitsunobu Miyagi レーザプローブ
EP2079782B1 (de) 2006-10-05 2012-05-23 Treofan Germany GmbH & Co.KG Simultan verstreckte opake folie aus pla
DE102007006825A1 (de) 2007-02-07 2008-08-14 Evonik Röhm Gmbh Kunststoffformkörper mir anisotroper Lichtstreuung
DE102007055491A1 (de) 2007-11-21 2009-06-04 Mitsubishi Polyester Film Gmbh Niedrigsiegelnde Polyesterfolie für polare Substrate
KR101043657B1 (ko) * 2008-09-23 2011-06-22 김명호 와이어제품 성형장치
WO2010096593A2 (en) 2009-02-18 2010-08-26 Northwestern University Beam pen lithography
US8900719B2 (en) 2010-04-14 2014-12-02 Avery Dennison Corporation Blends of ethylene copolymers and propylene based plastomers in multilayer films for low noise and RF welding
US9452593B2 (en) 2010-04-15 2016-09-27 Topas Advanced Polymers, Inc. Melt blends of amorphous cycloolefin polymers and partially crystalline cycloolefin elastomers with improved toughness
DE102010030074A1 (de) 2010-06-15 2011-12-15 Evonik Degussa Gmbh Kunststoff-Photovoltaik-Modul und Verfahren zu seiner Herstellung
EP2598330A1 (en) 2010-07-27 2013-06-05 Exxonmobil Oil Corporation Film composition and method of making the same
EP2915665A1 (en) 2011-12-22 2015-09-09 Avery Dennison Corporation Flexible Barrier Films Containing Cyclic Olefins
CN108189498B (zh) 2012-01-31 2020-06-23 纳幕尔杜邦公司 包含环烯烃共聚物的多层膜
WO2017155712A1 (en) 2016-03-11 2017-09-14 Topas Advanced Polymers, Inc. Injection stretch blow-molding (isbm) enhancement for semi-crystalline polyolefin containers utilizing alicyclic polyolefins
KR102325932B1 (ko) 2016-05-12 2021-11-17 에스에이치피피 글로벌 테크놀러지스 비.브이. 고온 성능을 갖는 커패시터 필름, 이의 제조 방법 및 물품
AR109065A1 (es) 2016-07-28 2018-10-24 Dow Global Technologies Llc Estructuras multicapa, películas multicapa y envases formados a partir de ellas
US10951875B2 (en) 2018-07-03 2021-03-16 Raxium, Inc. Display processing circuitry
DE102018215422A1 (de) 2018-09-11 2020-03-12 Mitsubishi Polyester Film Gmbh Heißsiegelbare Polyesterfolie für die Herstellung von Menüschalen, Verfahren zu ihrer Herstellung und ihre Verwendung
DE102019200365A1 (de) 2019-01-14 2020-07-16 Mitsubishi Polyester Film Gmbh Packung aus Polyester mit einer thermoformbaren Unterfolie und einer siegel- und peelbaren Oberfolie, Verfahren zu ihrer Herstellung und ihre Verwendung
US11710445B2 (en) 2019-01-24 2023-07-25 Google Llc Backplane configurations and operations
US11637219B2 (en) 2019-04-12 2023-04-25 Google Llc Monolithic integration of different light emitting structures on a same substrate
US11238782B2 (en) 2019-06-28 2022-02-01 Jasper Display Corp. Backplane for an array of emissive elements
US11626062B2 (en) 2020-02-18 2023-04-11 Google Llc System and method for modulating an array of emissive elements
CN115362491B (zh) 2020-04-06 2025-04-08 谷歌有限责任公司 显示组件
US11538431B2 (en) 2020-06-29 2022-12-27 Google Llc Larger backplane suitable for high speed applications
KR20230098903A (ko) 2020-12-21 2023-07-04 구글 엘엘씨 자동시청 3d 디스플레이용 고밀도 픽셀 어레이
DE102023100507A1 (de) 2023-01-11 2024-07-11 Mitsubishi Polyester Film Gmbh Koextrudierte, heißsiegelbare und peelfähige Polyesterfolie, Verfahren zu ihrer Herstellung und ihre Verwendung
DE102023100500A1 (de) 2023-01-11 2024-07-11 Mitsubishi Polyester Film Gmbh Polyesterverpackung bestehend aus thermoformbarer Unterfolie und peelfähiger Oberfolie, Verfahren zu ihrer Herstellung und ihre Verwendung
DE102023108752A1 (de) 2023-04-05 2024-10-10 Mitsubishi Polyester Film Gmbh Mehrschichtige, coextrudierte Polyesterfolie mit verringerter Durchstossfestigkeit zur Verwendung als Blisterabdeckfolie

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3835044A1 (de) * 1988-10-14 1990-04-19 Hoechst Ag Verfahren zur herstellung von cycloolefinpolymeren
US5087677A (en) * 1989-07-08 1992-02-11 Hoechst Aktiengesellschaft Process for the preparation of cycloolefin polymers

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5003019A (en) * 1987-03-02 1991-03-26 Mitsui Petrochemical Industries, Ltd. Cyclo-olefinic random copolymer, olefinic random copolymer, and process for producing cyclo-olefinic random copolymers
DE3726325A1 (de) * 1987-08-07 1989-02-16 Hoechst Ag Verfahren zur herstellung eines olefinpolymers
DE68911435T2 (de) * 1988-09-05 1994-04-28 Idemitsu Kosan Co Verfahren zur Herstellung eines Polymers.
DE3927257A1 (de) 1989-08-18 1991-02-21 Hoechst Ag Verfahren zur herstellung eines polyolefins

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3835044A1 (de) * 1988-10-14 1990-04-19 Hoechst Ag Verfahren zur herstellung von cycloolefinpolymeren
US5087677A (en) * 1989-07-08 1992-02-11 Hoechst Aktiengesellschaft Process for the preparation of cycloolefin polymers

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU649520B2 (en) * 1991-02-27 1994-05-26 Hoechst Aktiengesellschaft Cycloolefin (co)polymers with a narrow molecular weight distribution and a process for the preparation thereof

Also Published As

Publication number Publication date
DE59108971D1 (de) 1998-05-28
HU913539D0 (en) 1992-01-28
NO914439L (no) 1992-05-15
ATE165372T1 (de) 1998-05-15
CA2055397A1 (en) 1992-05-15
ZA918990B (en) 1992-07-29
KR920009859A (ko) 1992-06-25
HUT59429A (en) 1992-05-28
TW227005B (enrdf_load_stackoverflow) 1994-07-21
NO914439D0 (no) 1991-11-13
CS344291A3 (en) 1992-09-16
EP0485893B1 (de) 1998-04-22
AU8777791A (en) 1992-05-21
EP0485893A1 (de) 1992-05-20
JP3247130B2 (ja) 2002-01-15
KR100230915B1 (ko) 1999-11-15
ES2117632T3 (es) 1998-08-16
CA2055397C (en) 2004-04-20
JPH04268312A (ja) 1992-09-24

Similar Documents

Publication Publication Date Title
AU641291B2 (en) Bulk polymerization using specific metallocene catalysts for the preparation of cycloolefin polymers
AU1121692A (en) Cycloolefin (co)polymers with a narrow molecular weight distribution and a process for the preparation thereof
CA2062201A1 (en) Process for the preparation of chemically homogeneous cycloolefin copolymers
DE69925939D1 (de) Additionspolymerisation in einer form unter benutzung von polymeren des norbornentyps mit gruppe-3-metallkomplexen
CA2024899A1 (en) Olefin polymerization catalysts
CA2020640A1 (en) Process for the preparation of cycloolefin polymers
CA2036141A1 (en) Olefin polymerization solid catalysts and process for the polymerization of olefins
AU3559893A (en) Catalyst for the polymerization of olefins, process for its preparation and its use
RU93004723A (ru) Катализатор для полимеризации олефинов, способ его получения и способ гомо- или сополимеризации олефинов
FI963759A7 (fi) Metalloseeniyhdisteitä, menetelmä niiden valmistamiseksi ja niiden käyttö olefiinien polymerointiin tarkoitetuissa katalyyteissä
FI98819B (fi) Prosessi olefiinipolymeerien valmistamiseksi ja prosessilla valmistetut tuotteet
ES2119915T3 (es) Material de un copolimero de cicloolefinas y procedimiento para su fabricacion.
CA2087181A1 (en) Group IVB, VB and VIB Metal Hydrocarbyloxides, with Alumoxane for Olefin Polymerization
CA2043075A1 (en) Dicyclopentadiene activation method and polymerization composition
DE68921647D1 (de) Katalysatorzusammensetzung zur Herstellung von Alpha-olefin-polymeren mit enger Molekulargewichtsverteilung.
EP0385556A3 (en) Polymerization of bulky norbornene derivatives and polymers obtainable therewith
AU2974089A (en) Olefin polymerization catalyst and process for the polymerization of olefins
AU1015292A (en) Metallocene (CO)polymers, process for their preparation and their use as catalysts
AU6023690A (en) Preparation of carbon monoxide/olefin polymers using two or more reactors in series
AU3194393A (en) Catalyst for the polymerization of olefins, process for the preparation thereof, and use thereof
AU2343192A (en) Polymerization process and products
EP0372600A3 (en) Copolymerization of dicyclopentadiene with norbornene derivatives and copolymers obtainable therewith
DE50005290D1 (de) Geträgerte Katalysatoren mit einer Donor-Akzeptor-Wechselwirkung
Brekner et al. Cycloolefin(Co) Polymers With a Narrow Molecular Weight Distribution and Process for Their Production
CA2051059A1 (en) Substituted acetylenes as rate moderators for ring-opening metathesis polymerization