DE59508992D1 - In einem Rohr angeordneter Mischer - Google Patents

In einem Rohr angeordneter Mischer

Info

Publication number
DE59508992D1
DE59508992D1 DE59508992T DE59508992T DE59508992D1 DE 59508992 D1 DE59508992 D1 DE 59508992D1 DE 59508992 T DE59508992 T DE 59508992T DE 59508992 T DE59508992 T DE 59508992T DE 59508992 D1 DE59508992 D1 DE 59508992D1
Authority
DE
Germany
Prior art keywords
elements
baffle
fluid flow
mixer
along
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.)
Expired - Lifetime
Application number
DE59508992T
Other languages
English (en)
Inventor
Felix Streiff
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.)
Sulzer Chemtech AG
Original Assignee
Sulzer Chemtech 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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=8221764&utm_source=***_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=DE59508992(D1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Sulzer Chemtech AG filed Critical Sulzer Chemtech AG
Application granted granted Critical
Publication of DE59508992D1 publication Critical patent/DE59508992D1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/40—Static mixers
    • B01F25/42—Static mixers in which the mixing is affected by moving the components jointly in changing directions, e.g. in tubes provided with baffles or obstructions
    • B01F25/43—Mixing tubes, e.g. wherein the material is moved in a radial or partly reversed direction
    • B01F25/432—Mixing tubes, e.g. wherein the material is moved in a radial or partly reversed direction with means for dividing the material flow into separate sub-flows and for repositioning and recombining these sub-flows; Cross-mixing, e.g. conducting the outer layer of the material nearer to the axis of the tube or vice-versa
    • B01F25/4321—Mixing tubes, e.g. wherein the material is moved in a radial or partly reversed direction with means for dividing the material flow into separate sub-flows and for repositioning and recombining these sub-flows; Cross-mixing, e.g. conducting the outer layer of the material nearer to the axis of the tube or vice-versa the subflows consisting of at least two flat layers which are recombined, e.g. using means having restriction or expansion zones
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Dispersion Chemistry (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
  • Food-Manufacturing Devices (AREA)
  • Filling, Topping-Up Batteries (AREA)
DE59508992T 1995-06-21 1995-06-21 In einem Rohr angeordneter Mischer Expired - Lifetime DE59508992D1 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP95810418A EP0749776B1 (de) 1995-06-21 1995-06-21 In einem Rohr angeordneter Mischer

Publications (1)

Publication Number Publication Date
DE59508992D1 true DE59508992D1 (de) 2001-03-01

Family

ID=8221764

Family Applications (2)

Application Number Title Priority Date Filing Date
DE59508992T Expired - Lifetime DE59508992D1 (de) 1995-06-21 1995-06-21 In einem Rohr angeordneter Mischer
DE29522199U Expired - Lifetime DE29522199U1 (de) 1995-06-21 1995-06-21 In einem Rohr angeordneter Mischer

Family Applications After (1)

Application Number Title Priority Date Filing Date
DE29522199U Expired - Lifetime DE29522199U1 (de) 1995-06-21 1995-06-21 In einem Rohr angeordneter Mischer

Country Status (11)

Country Link
US (1) US5944419A (de)
EP (1) EP0749776B1 (de)
JP (1) JP4283901B2 (de)
KR (1) KR100420822B1 (de)
CN (1) CN1052171C (de)
AT (1) ATE198839T1 (de)
BR (1) BR9602858A (de)
CA (1) CA2178065C (de)
DE (2) DE59508992D1 (de)
ES (1) ES2155509T3 (de)
TW (1) TW315314B (de)

Families Citing this family (100)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE40407E1 (en) 1999-05-24 2008-07-01 Vortex Flow, Inc. Method and apparatus for mixing fluids
EP1125626B1 (de) * 2000-02-17 2005-11-02 Sulzer Chemtech AG Statischer Mischer
ATE308375T1 (de) * 2000-02-17 2005-11-15 Sulzer Chemtech Ag Statischer mischer
DE20002920U1 (de) 2000-02-18 2000-04-20 Schroeder & Boos Misch Und Anl Homogenisator
SI1412078T1 (sl) 2001-08-02 2009-04-30 Lg Life Sciences Ltd Lg Twin T Postopki za pripravo amino-zaščitenih derivatov 4-aminometilen-pirolidin-3-ona, gemifloksacina ali njegove soli
DE10158651B4 (de) * 2001-11-30 2016-02-04 Ritter Gmbh Statisches Mischelement
ATE242045T1 (de) * 2002-03-22 2003-06-15 Sulzer Chemtech Ag Rohrmischer mit einem longitudinalen einbaukörper
US6773156B2 (en) * 2002-07-10 2004-08-10 Tah Industries, Inc. Method and apparatus for reducing fluid streaking in a motionless mixer
PT1426099E (pt) * 2002-12-06 2007-12-04 Systems Ag Misturador estático e método
AU2004234018B2 (en) * 2003-04-28 2009-01-29 Hansom Environmental Products Pty Ltd Method and apparatus for mixing fluids for particle agglomeration
RU2005136880A (ru) * 2003-04-28 2006-03-20 Индиго Текнолоджиз Груп Пти Лтд. (Au) Способ и устройство для перемешивания текучих сред для агломерации частиц
US7198400B2 (en) * 2003-05-03 2007-04-03 Husky Injection Molding Systems Ltd. Static mixer and a method of manufacture thereof
DE10322922A1 (de) * 2003-05-21 2004-12-16 Fischerwerke Artur Fischer Gmbh & Co. Kg Statikmischer
AU2003292650A1 (en) * 2003-12-26 2005-08-12 Shinyou Technologies Inc. Static mixer
DE102004046226A1 (de) * 2004-09-22 2006-04-06 Heraeus Kulzer Gmbh Verfahren zum Mischen der Komponenten von Polyetherabformmassen
EP1720664A1 (de) * 2004-02-27 2006-11-15 Heraeus Kulzer GmbH Verfahren zur herstellung von dentalen abformmassen und vorrichtungen hierzu
DE602005021003D1 (de) * 2004-02-27 2010-06-17 Haldor Topsoe As Vorrichtung zum Mischen von Fluidströmen
TWI354577B (en) * 2004-04-22 2011-12-21 Sulzer Chemtech Ag A static mixer for a curing mixed product
KR100711352B1 (ko) * 2005-06-23 2007-04-27 삼성전자주식회사 파장 잠김된 광송신기를 이용한 파장분할다중 방식의수동형 광네트워크
AU2006332839A1 (en) * 2005-12-29 2007-07-12 3M Innovative Properties Company Dental compositions and initiator systems with polycyclic aromatic component
JP4713397B2 (ja) * 2006-01-18 2011-06-29 株式会社リコー 微小流路構造体及び微小液滴生成システム
JP2007209862A (ja) * 2006-02-07 2007-08-23 Bco:Kk 攪拌装置および浄水システム
EP2008636A1 (de) * 2007-06-29 2008-12-31 3M Innovative Properties Company Dentale Zusammensetzung mit polyfunktionalem (Meth)Acrylat mit Urethan-, Harnstoff- oder Amidgruppen, Verfahren zu deren Herstellung und Verwendung
DE202008007801U1 (de) 2007-09-19 2008-08-21 Kettenbach Gmbh & Co. Kg Behälter
EP2042486A1 (de) * 2007-09-26 2009-04-01 3M Innovative Properties Company Auf Methacrylat basierende Monomere mit einer Urethanbindung, Herstellungsverfahren und Verwendung
EP2133063A1 (de) * 2008-06-10 2009-12-16 3M Innovative Properties Company Initiatorsystem mit Biphenylen-Derivaten, Herstellungsverfahren und Verwendung dafür
EP2133064A1 (de) 2008-06-10 2009-12-16 3M Innovative Properties Company Initiatorsystem mit einem Diarylalkylamin-Derivat, härtbare Zusammensetzung und deren Verwendung
US8083397B2 (en) 2008-06-13 2011-12-27 Nordson Corporation Static mixer
SG161141A1 (en) * 2008-10-17 2010-05-27 Sulzer Mixpac Ag Static mixer
CH699958A1 (de) * 2008-11-27 2010-05-31 Medmix Systems Ag Statischer Mischer.
CA2686581C (en) 2009-02-11 2017-06-27 Sulzer Mixpac Ag Intermediate piece for the connection of a storage container to a static mixer
TWI524932B (zh) 2009-03-11 2016-03-11 素路彩米克斯派克股份有限公司 用於排出填料的設備
EP2286925B1 (de) 2009-08-20 2018-03-14 Sulzer Mixpac AG Statischer Sprühmischer
US7985020B2 (en) * 2009-09-25 2011-07-26 Nordson Corporation Cross flow inversion baffle for static mixer
DE102009054652A1 (de) 2009-12-15 2011-06-16 Hilti Aktiengesellschaft Statischer Mischer
WO2011119820A1 (en) * 2010-03-25 2011-09-29 Nordson Corporation Inline static mixer
WO2011162728A1 (en) * 2010-06-23 2011-12-29 Gluetec Gmbh & Co. Kg Static mixer with asymmetric mixing elements
EP2401998A1 (de) 2010-07-02 2012-01-04 3M Innovative Properties Company Dentale Zusammensetzung, Satz aus Teilen und Verwendung davon
EP2407249A1 (de) 2010-07-16 2012-01-18 Sulzer Mixpac AG Zwischenstück zur Verbindung einer Kartusche mit einem statischen Mischer
US9770728B2 (en) 2010-07-20 2017-09-26 Sulzer Mixpac Ag Static spray mixer
BR112012033175B8 (pt) 2010-07-20 2023-03-21 Sulzer Mixpac Ag Misturador de pulverização estático
JP5733955B2 (ja) * 2010-11-16 2015-06-10 キヤノン株式会社 撹拌装置
WO2012095178A1 (de) 2011-01-13 2012-07-19 Sulzer Mixpac Ag Vorrichtung zum ausbringen einer füllmasse
EP2481390A1 (de) 2011-01-31 2012-08-01 3M Innovative Properties Company Dentale Zusammensetzung, Satz aus Teilen und Verwendung davon
WO2012112321A2 (en) 2011-02-15 2012-08-23 3M Innovative Properties Company Dental compositions comprising mixture of isocyanurate monomer and tricyclodecane monomer
ES2699955T3 (es) 2011-05-23 2019-02-13 Sulzer Mixpac Ag Combinación de un mezclador pulverizador estático con una pieza intermedia
DE202011050465U1 (de) 2011-06-16 2011-08-17 Vosschemie Gmbh Statischer Mischer zum Mischen von mindestens zwei fließfähigen Komponenten
DE102011077645A1 (de) * 2011-06-16 2012-12-20 Bosch Emission Systems Gmbh & Co. Kg Statischer Mischer
CA2775346C (en) * 2011-07-22 2019-03-05 Sulzer Mixpac Ag Static mixer
EP2741728B1 (de) 2011-08-11 2019-06-26 3M Innovative Properties Company Dentale zusammensetzung, verfahren zur herstellung und verwendung damit
JP5166587B2 (ja) * 2011-10-17 2013-03-21 株式会社東芝 固液分離システム
CA2789725C (en) * 2011-11-29 2019-08-06 Sulzer Mixpac Ag Mixing element for a static mixer
JP6077741B2 (ja) * 2011-12-06 2017-02-08 キヤノン株式会社 温度ばらつき低減用流体撹拌装置
EP2614883B1 (de) 2012-01-11 2015-04-15 Sulzer Mixpac AG Mischelement und statischer Mischer
EP2833991B1 (de) 2012-05-14 2018-01-31 Sulzer Mixpac AG Sprühmischer zum mischen und sprühen von mindestens zwei fliessfähigen komponenten
EP2888031A1 (de) 2012-08-21 2015-07-01 Medmix Systems AG Mischvorrichtung für eine austrageinheit
KR101432185B1 (ko) * 2012-11-14 2014-08-20 주식회사 생 4각관 판나선형 라인 믹서
US9782329B2 (en) 2013-07-08 2017-10-10 3M Innovative Properties Company Hardenable dental composition containing a mixture of agglomerated and aggregated nano-particles, kit of parts and use thereof
WO2015034977A1 (en) 2013-09-09 2015-03-12 3M Innovative Properties Company Dental composition containing polyoxometalates, process of production and use thereof
WO2015126666A1 (en) 2014-02-18 2015-08-27 3M Innovative Properties Company Dental composition and use thereof
JP6599346B2 (ja) 2014-02-18 2019-10-30 スリーエム イノベイティブ プロパティズ カンパニー 歯科用組成物及びその使用
US9927064B2 (en) 2014-03-10 2018-03-27 Toyota Motor Engineering & Manufacturing North America, Inc. Flow-restricting plug and differential drive pinion having the same
RU2683315C2 (ru) 2014-07-10 2019-03-28 3М Инновейтив Пропертиз Компани Двухкомпонентный самоклеящийся стоматологический состав, способ его изготовления и применения
US9724653B2 (en) 2015-02-12 2017-08-08 Nordson Corporation Double wedge mixing baffle and associated static mixer and methods of mixing
US10548818B2 (en) 2015-07-21 2020-02-04 3M Innovative Properties Company Kit of parts for producing a glass ionomer cement, process of production and use thereof
US10245565B2 (en) 2015-08-07 2019-04-02 Nordson Corporation Double wall flow shifter baffles and associated static mixer and methods of mixing
US10363526B2 (en) 2015-08-07 2019-07-30 Nordson Corporation Entry mixing elements and related static mixers and methods of mixing
US10874594B2 (en) 2015-12-08 2020-12-29 3M Innovative Properties Company Two-component self-adhesive dental composition, storage stable initiator system, and use thereof
US10799429B2 (en) * 2016-02-25 2020-10-13 3M Innovative Properties Company Kit of parts for producing a paste type glass ionomer cement, process of production and use thereof
US10232327B2 (en) * 2016-03-03 2019-03-19 Nordson Corporation Flow inverter baffle and associated static mixer and methods of mixing
CH713229A1 (de) 2016-12-14 2018-06-15 Streiff Felix Mischelemente mit hoher Festigkeit und Mischwirkung.
WO2018169704A1 (en) 2017-03-15 2018-09-20 3M Innovative Properties Company Glass ionomer compositions and methods including inorganic fibers
US11304880B2 (en) 2017-05-18 2022-04-19 3M Innovative Properties Company Glass ionomer compositions and methods including water-miscible, silane-treated, nano-sized silica particles
US10722853B2 (en) * 2017-08-04 2020-07-28 Nordson Corporation Static mixer without mixing baffle sidewalls and associated mixing conduit
EP3479893A1 (de) 2017-11-06 2019-05-08 Sulzer Chemtech AG Verbesserter mischerkanal und verfahren zur verwendung davon
JP6942888B2 (ja) 2017-11-08 2021-09-29 スリーエム イノベイティブ プロパティズ カンパニー 高弾性率の歯科用組成物
WO2019123260A2 (en) 2017-12-19 2019-06-27 3M Innovative Properties Company Multi-part composition having staged viscosity prior to hardening
EP3727276A2 (de) 2017-12-21 2020-10-28 3M Innovative Properties Company Anorganische dentalfüller mit einer silanbehandelten oberfläche
WO2019155334A1 (en) 2018-02-06 2019-08-15 3M Innovative Properties Company Microcapsule with a porous or hollow core and ph-sensitive shell use thereof
EP3773420A1 (de) 2018-04-03 2021-02-17 3M Innovative Properties Company Lagerstabile glasionomerzusammensetzung und verwendung davon
JP6984044B2 (ja) 2018-05-02 2021-12-17 スリーエム イノベイティブ プロパティズ カンパニー 歯科用複合材料を固定するための一剤型歯科用接着剤組成物
CN112996472A (zh) 2018-11-14 2021-06-18 3M创新有限公司 储存稳定的双组分双固化牙科组合物
DE202018106654U1 (de) 2018-11-22 2019-02-06 Sulzer Mixpac Ag Statischer Mischer
CH716236A2 (de) * 2019-05-28 2020-11-30 Streiff Felix Rohrbündel-Wärmeübertrager mit Einbauelementen aus Umlenkflächen und Leitstegen.
CN113905812A (zh) 2019-06-04 2022-01-07 3M创新有限公司 具有多孔或中空的芯以及包含在与酸接触时释放气体的组分的壳的微胶囊
US11562726B2 (en) 2019-12-17 2023-01-24 Emerson Process Management Regulator Technologies, Inc. Plates and plate assemblies for noise attenuators and other devices and methods making the same
US11282491B2 (en) * 2019-12-17 2022-03-22 Emerson Process Management Regulator Technologies, Inc. Plates and plate assemblies for noise attenuators and other devices and methods making the same
WO2021165795A1 (en) 2020-02-19 2021-08-26 3M Innovative Properties Company Ascorbic acid component for use in a method of treating the surface of a prepared tooth
CH717390A2 (de) 2020-05-06 2021-11-15 Streiff Felix Baugruppen/Einbauelemente aus Umlenkflächen mit Trennstegen für den Einbau in Rohre/Kanäle oder in den Mantelraum von Rohrbündel-Wärmetauschern.
EP4164808A1 (de) 2020-11-11 2023-04-19 medmix Switzerland AG Verbesserte statische mischspitze
EP4000749A1 (de) 2020-11-11 2022-05-25 medmix Switzerland AG Verbesserte statische mischspitze
JP2023552995A (ja) 2020-12-04 2023-12-20 スリーエム イノベイティブ プロパティズ カンパニー 歯科用ｐＨ感受性マイクロカプセル
CN112892270B (zh) * 2021-02-25 2023-02-10 煜环环境科技有限公司 一种用于土壤修复的卧式双轴逆向差速高效搅拌装置
US20240189196A1 (en) 2021-04-29 2024-06-13 3M Innovative Properties Company Initiator system with polymerizable thiourea component, dental composition and use thereof
EP4329703A1 (de) 2021-04-29 2024-03-06 3M Innovative Properties Company Calcium- und fluorionen freisetzende dentalzusammensetzung
WO2023275637A1 (en) 2021-06-28 2023-01-05 3M Innovative Properties Company Dental cement composition, kit of parts and use thereof
EP4282516A1 (de) 2022-05-23 2023-11-29 Henkel AG & Co. KGaA Vorrichtung und verfahren zum sprühen eines mehrkomponenten-kunststoffs
EP4371657A1 (de) 2022-11-18 2024-05-22 medmix Switzerland AG Statischer mischer
EP4371656A1 (de) 2022-11-18 2024-05-22 medmix Switzerland AG Statischer mischer mit trennmittel
WO2024121658A1 (en) 2022-12-06 2024-06-13 Solventum Intellectual Properties Company Surface-treated filler, dental composition containing such a filler, process of production and use thereof

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL103356C (de) 1958-07-08 1900-01-01
US3195865A (en) * 1960-09-09 1965-07-20 Dow Chemical Co Interfacial surface generator
US3406947A (en) * 1966-08-19 1968-10-22 Dow Chemical Co Interfacial surface generator
US3620506A (en) * 1970-07-07 1971-11-16 Fmc Corp Fluid-mixing device
JPS5233822B2 (de) * 1972-03-18 1977-08-31
DE2343352A1 (de) * 1973-08-28 1975-03-13 Worcester Valve Co Ltd Vorrichtung zum mischen von fluden
DE2808854C2 (de) 1977-05-31 1986-05-28 Gebrüder Sulzer AG, 8401 Winterthur Mit Einbauten versehener Strömungskanal für ein an einem indirekten Austausch, insbesondere Wärmeaustausch, beteiligtes Medium
US4179222A (en) * 1978-01-11 1979-12-18 Systematix Controls, Inc. Flow turbulence generating and mixing device
CA1129303A (en) * 1978-07-19 1982-08-10 Figgie International Inc. Pressure-demand breathing apparatus with automatic air shut-off
US4255124A (en) * 1978-10-05 1981-03-10 Baranowski Jr Frank Static fluid-swirl mixing
DE3214056C2 (de) * 1982-04-16 1985-04-18 Purma Industrieanlagen GmbH, 7100 Heilbronn Statischer Mischer für flüssige und/oder pastöse Komponenten
DE3420290C1 (de) * 1984-05-30 1986-01-02 Ritter-Plastic GmbH, 8931 Untermeitingen Statisches Mischteil
DE59309826D1 (de) * 1993-11-26 1999-11-11 Sulzer Chemtech Ag Winterthur Statische Mischvorrichtung

Also Published As

Publication number Publication date
EP0749776A1 (de) 1996-12-27
EP0749776B1 (de) 2001-01-24
CN1052171C (zh) 2000-05-10
KR100420822B1 (ko) 2004-05-22
KR970000319A (ko) 1997-01-21
JP4283901B2 (ja) 2009-06-24
CA2178065A1 (en) 1996-12-22
CA2178065C (en) 2000-05-30
JPH09901A (ja) 1997-01-07
CN1148518A (zh) 1997-04-30
TW315314B (de) 1997-09-11
DE29522199U1 (de) 2000-08-17
BR9602858A (pt) 1998-04-22
ES2155509T3 (es) 2001-05-16
US5944419A (en) 1999-08-31
ATE198839T1 (de) 2001-02-15

Similar Documents

Publication Publication Date Title
DE59508992D1 (de) In einem Rohr angeordneter Mischer
PT70752A (de) Mehrkammer-photoreaktor
ATE46032T1 (de) Gas/fluessigkeit- oder gas/gas-waermeaustauscher.
DK0758917T3 (da) Statisk tvangsblander
AU4844697A (en) Electrodialysis apparatus
KR960031954A (ko) 열교환기의 핀
ES485335A1 (es) Polea para correas, con diametro de trabajo variable
GB1349817A (en) Slide dampers
DK160185D0 (da) Varmeveksler
US4159738A (en) Fan-assisted forced flow air-cooling heat exchanger system
ES267732U (es) Aparato de regulacion de caudal para grifos.
DE3670130D1 (de) Gasverdichter mit veraenderlicher foerdermenge.
KR830008132A (ko) 태양 에너지 집열기
Yoshikawa Harmonic generation mechanism in organ pipes
JPH05212259A (ja) スタティックミキサー
SU746156A1 (ru) Регулируемый дроссель
DE3671504D1 (de) Gasverdichter mit variabler durchflussmenge.
ATE133473T1 (de) Verstellbarer radialdiffusor
JPS6186594A (ja) 熱交換器
NO151799C (no) Kantprofilert plateelement til anvendelse som veggelement i et vingeformet hulromsprofil og spjeldblad til et ventilasjonsspjeld tildannet av et eller to slike plateelementer
SU1117410A1 (ru) Рабочее колесо насоса
SE405642B (sv) Plattvermevexlare for strommande media, foretredesvis luft, innefattande omvexlande plana och korrugerade folier
SU571664A2 (ru) Вихрева горелка
RU1773279C (ru) Глушитель шума газового потока
SU1366790A1 (ru) Завихритель горелочного устройства

Legal Events

Date Code Title Description
8364 No opposition during term of opposition