EP0395359B1 - Elektroisolierende elektroviskose Flüssigkeiten - Google Patents

Elektroisolierende elektroviskose Flüssigkeiten Download PDF

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Publication number
EP0395359B1
EP0395359B1 EP90304402A EP90304402A EP0395359B1 EP 0395359 B1 EP0395359 B1 EP 0395359B1 EP 90304402 A EP90304402 A EP 90304402A EP 90304402 A EP90304402 A EP 90304402A EP 0395359 B1 EP0395359 B1 EP 0395359B1
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EP
European Patent Office
Prior art keywords
electroviscous
amine
electroviscous fluid
fluid
antioxidant
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
EP90304402A
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English (en)
French (fr)
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EP0395359A1 (de
Inventor
Hirotaka C/O Tonen Corp. Res. And Dev. Tomizawa
Makoto C/O Tonen Corp. Res. And Dev. Kanbara
Masahiko C/O Tonen Corp. Res. And Dev. Hayafune
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.)
Tonen General Sekiyu KK
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Tonen Corp
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Publication date
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M171/00—Lubricating compositions characterised by purely physical criteria, e.g. containing as base-material, thickener or additive, ingredients which are characterised exclusively by their numerically specified physical properties, i.e. containing ingredients which are physically well-defined but for which the chemical nature is either unspecified or only very vaguely indicated
    • C10M171/001—Electrorheological fluids; smart fluids

Definitions

  • the present invention relates to an electroviscous fluid, the viscosity of which can be controlled by applying voltage, and in particular to an electroviscous fluid, in which the viscosity is changed rapidly and reversibly from low temperature range to high temperature range when voltage is applied and a long and stable electroviscous effect is obtained and which can be used for electrical control of mechanical devices such as a clutch, valve or shock absorber.
  • Winslow proposed an electroviscous fluid, using paraffin, silica gel powder and adding water to make the system slightly electroconductive (Winslow, W.M., J. of Applied Physics, Vol. 20 (1949) 1137). From this study by Winslow, the electroviscous (electro-rheological) effect of the electroviscous fluid is called the ER effect or Winslow effect.
  • each particle forms a bridge (cross-linkage) between electrodes and the shear-resistant force to the external stress, i.e., ER effect.
  • an electroviscous fluid having an electrically insulating fluid as a dispersion medium, and in which is dispersed by weight:
  • an antioxidant and/or corrosion inhibitor are added to such electroviscous fluid to obtain better effects in the responsiveness of viscosity change in a wide temperature range up to high temperature, reproducibility, electroviscous effect and, especially, durability.
  • a mineral oil or synthetic lubricant oil can for example be used. More specifically, there are oils such as a paraffinic oil, naphthenic oil, poly- ⁇ -olefin, polyalkylene glycol, silicone oil, diester, polyolester, phosphoric acid ester, silicon compound, fluorine compound or polyphenylether.
  • oils such as a paraffinic oil, naphthenic oil, poly- ⁇ -olefin, polyalkylene glycol, silicone oil, diester, polyolester, phosphoric acid ester, silicon compound, fluorine compound or polyphenylether.
  • An electroviscous fluid having a viscosity of 5 - 300 cP at 40°C can be used.
  • porous solid particles for example, silica gel, moisture-containing resin, diatomaceous earth, alumina, silica-alumina, zeolite, an ion exchange resin or cellulose, can be used.
  • the porous solid particles having a particle size of 10 nm - 200 ⁇ m are used in the ratio of 0.1 - 50 wt%. If it is less than 0.1 wt%. the ER effect is too low, and if it exceeds 50 wt%, the dispersing property is decreased.
  • a dispersing agent may optionally be used in the electroviscous fluid of this invention in order to disperse the porous solid particles evenly and stably.
  • Suitable dispersing agents are sulphonates, phenates, phosphonates, succinimide, amines or non-ionic dispersing agents, e. g., magnesium sulphonate, calcium sulphonate, calcium phosphonate, polybutenyl succinic acid imide, sorbitan mono-oleate or sorbitan sesqui -oleate. These are normally used at the ratio of 0.1 - 10 wt%, while they need not be used if the porous solid particles are easily dispersed.
  • polyhydric alcohol dihydric alcohols and trihydric alcohols are effective. It is preferable to use ethylene glycol, glycerin, propanediol, butanediol or hexanediol; these substances are used at a ratio of 1 - 30 wt% of the porous solid particles, preferably at 2 - 15 wt%. If the ratio is less than 1 wt%, the ER effect is too low, and if it exceeds 30 wt%, this is undesirable because electric current then flows too easily.
  • Acid, salt or base components are included to obtain a higher ER effect.
  • Polyhydric alcohol components keep the ER effect at a high temperature, while acid, salt or base components can increase the polarization effect. By using these components simultaneously, it is possible to increase the ER effect at high temperature.
  • inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, perchloric acid, chromic acid, phosphoric acid or boric acid, or inorganic acids such as acetic acid, formic acid, propionic acid, lactic acid, isolactic acid, valeric acid, oxalic acid or malonic acid can be used.
  • any compound consisting of a metal or base radical (such as NH4+, N2H5+) and acid radical can be used.
  • a substance which dissolves in a polyhydric alcohol or mixture of polyhydric alcohol and water and is dissociated, or typical ionic crystal such as a halogenated compound of an alkali metal or alkali earth metal, or the alkali salt of an organic acid; e.g., LiCl, NaCl, KCl, MgCl2, CaCl2, BaCl2, LiBr, NaBr, KBr, MgBr2, LiI, NaI, KI, AgNO3, Ca(NO3)2, NaNO2, NH4NO3, K2SO4, Na2SO4, NaHSO4, (NH4)2SO4 or an alkali salt of an acid such as formic acid, acetic acid, oxalic acid or succinic acid.
  • a base to be used can be a hydroxide of an alkali earth metal, carbonate of an alkali metal or amine . It is preferable to use a substance which is dissolved in polyhydric alcohol or in the mixture of polyhydric alcohol and water and is disassociated, e.g., NaOH, KOH, Ca(OH)2, Na2CO3, NaHCO3, K3PO4, Na3PO4, aniline, an alkylamine or ethanolamine.
  • the salt and the base as described above may be used simultaneously.
  • the acid, salt or base is be used in the ratio of 0.01 - 5 wt% to the entire electroviscous fluid. If it is less than 0.01 wt%, the ER effect is too low; and if it exceeds 5 wt%, it is not desirable because electric current flows more easily and the electric power consumption increase.
  • An essential component of the fluid is an antioxidant and/or corrosion inhibitor.
  • Antioxidant is added to prevent the oxidation of the electrically insulating liquid and polyhydric alcohol and also to stop the increase of electric conductivity due to the formation of oxidation products.
  • Corrosion inhibitor is added to prevent the increase of electrical conductivity caused by the generation of metallic ions due-to the corrosion of the electrode (such as copper) under high voltage.
  • Antioxidants which are inactive to a polarizing agent and to the porous solid particles may be used, such as phenol-type or amine-type antioxidants.
  • Suitable phenol-type antioxidants are 2,6-di- t -butyl- para -cresol, 4,4'-methylene-bis(2,6-di- t -butyl-phenol) and 2,6-di-t-butyl-phenol
  • suitable amine-type antioxidants are dioctyl-diphenyl-amine, phenyl- ⁇ -naphthyl-amine, an alkyl diphenyl amine or N-nitro-diphenyl amine.
  • 2,6-di-t-butyl-para-cresol or dioctyl-diphenyl-amine is used.
  • These substances are used in the ratio of 0.01 - 10 wt% to the entire electroviscous fluid, and preferably 0.1 - 2.0 wt%. If the ratio is less than 0.01 wt%, the antioxidant effect is too low, and if it exceeds 10 wt%, problems occurs such as color tone deterioration, increased turbidity, generation of sludge and increase of viscosity.
  • a corrosion inhibitor which is inactive to the polarizing agent and porous solid particles e.g., nitrogen compounds such as benzotriazole and its derivatives, imidazoline, pyrimidine derivatives, and compounds containing sulfur and nitrogen, such as 1,3,4-thiadiazolepolysulfide, a 1,3,4-thiadiazolil-2,5-bis-dialkyl-dithiocarbomate, a 2-(alkyldithio)-benzoimidazole, ⁇ -( o -carboxybenzylthio)propionitrile or propionic acid; more preferably, benzotriazole or its derivatives are used.
  • nitrogen compounds such as benzotriazole and its derivatives, imidazoline, pyrimidine derivatives, and compounds containing sulfur and nitrogen, such as 1,3,4-thiadiazolepolysulfide, a 1,3,4-thiadiazolil-2,5-bis-dialkyl-dithiocarbomate, a 2-(
  • These substances are used in the ratio of 0.001 - 10 wt% to the entire electroviscous fluid, and preferably 0.01 - 1.0 wt%. If the ratio is less than 0.001 wt% there is no corrosion inhibition effect, and if it exceeds 10 wt%, problems occur such as color tone deterioration, increased turbidity, generation of sludge, and increase in the viscosity of the fluid.
  • the above substances are mixed together to make a basic fluid.
  • the viscosity of the mineral oil was adjusted in such manner that all of these samples have a viscosity of 80 cP at 40°C.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Lubricants (AREA)

Claims (7)

  1. Elektroviskose Flüssigkeit mit einer elektroisolierenden Flüssigkeit als einem Dispersionsmedium, in welchem nach Gewicht dispergiert ist:
    a) 0,1 bis 50% poröser Festkörperpartikel mit einer Partikelgröße von 10nm bis 200µm;
    b) ein mehrere Hydroxylgruppen enthaltender Alkohol in einer Menge von 1 bis 30% der porösen Festkörperpartikel;
    c) ein Antioxidationsmittel in einer Menge von 0,01 bis 10% und/oder ein Korrosionsinhibitor in einer Menge von 0,001 bis 10%; und
    d) wenigstens eine Art von Substanz ausgewählt aus einer Säure, Salz oder Base in einer Menge von 0,01 bis 5 Gew.-%.
  2. Elektroviskose Flüssigkeit nach Anspruch 1, worin das Antioxidationsmittel von einer Phenolart oder einer Aminart ist.
  3. Elektroviskose Flüssigkeit nach Anspruch 1, worin das Antioxidationsmittel 2,6-Di-t-Butyl-Para-Kresol, 4,4'-Methylen-Bis (2,6-Di-t-Butyl-Phenol), 2,6-Di-t-Butyl-Phenol, Dioctyl-Diphenyl-Amin, Phenyl-α-Naphthyl-Amin, ein Alkyldiphenylamin oder N-Nitro-Diphenylamin ist.
  4. Elektroviskose Flüssigkeit nach Anspruch 1, worin das Oxidationsmittel Benzotriazol oder ein Derivat davon, Imidazolin, ein Pyrimidinderivat oder eine Schwefel oder Stickstoff enthaltende Verbindung ist.
  5. Elektroviskose Flüssigkeit nach einem der vorangehenden Ansprüche, welche ebenso ein Mittel, welches die Dispersion der Festkörperpartikel unterstützt, in einer Menge von 0,1 bis 10% beinhaltet.
  6. Elektroviskose Flüssigkeit nach Anspruch 5, worin das Mittel ein Sulfonat, Phenat, Phosphonat, Succinimid, Amin oder nichtionisches Dispersionsmittel ist.
  7. Elektroviskose Flüssigkeit nach einem der vorangehenden Ansprüche, worin die elektroisolierende Flüssigkeit ein paraffinisches Öl, naphthenisches Öl, Poly-α-Olefin, Polyalkylenglykol, Silikonöl, Diester, Polyolester, Phosphorsäureester, Siliziumverbindung, Fluor-verbindung oder Polyphenyläther ist.
EP90304402A 1989-04-26 1990-04-24 Elektroisolierende elektroviskose Flüssigkeiten Expired - Lifetime EP0395359B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP106997/89 1989-04-26
JP10699789A JPH02284992A (ja) 1989-04-26 1989-04-26 電気粘性流体

Publications (2)

Publication Number Publication Date
EP0395359A1 EP0395359A1 (de) 1990-10-31
EP0395359B1 true EP0395359B1 (de) 1993-09-22

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EP90304402A Expired - Lifetime EP0395359B1 (de) 1989-04-26 1990-04-24 Elektroisolierende elektroviskose Flüssigkeiten

Country Status (3)

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EP (1) EP0395359B1 (de)
JP (1) JPH02284992A (de)
DE (1) DE69003434T2 (de)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE69220478T2 (de) * 1991-07-24 1997-10-23 Tonen Corp Elektroviskose Flüssigkeit
AU663113B2 (en) * 1991-10-10 1995-09-28 Camp, Inc. Electrorheological fluids containing electronically conductive polymers
US5595680A (en) * 1991-10-10 1997-01-21 The Lubrizol Corporation Electrorheological fluids containing polyanilines
DE69218915D1 (de) * 1991-10-10 1997-05-15 Lubrizol Corp Polyaniline enthaltende elektrorheologische Flüssigkeiten
DE4200113A1 (de) * 1992-01-04 1993-07-08 Henkel Kgaa Elektroviskose fluessigkeiten
AU666607B2 (en) * 1993-03-12 1996-02-15 Camp, Inc. Electrorheological fluids with hydrocarbyl aromatic hydroxy compounds
US5603861A (en) * 1993-09-28 1997-02-18 Tonen Corporation Electroviscous fluid mixed with esterified silica fine particles and polyhydric alcohol
AU2002341988A1 (en) * 2001-11-29 2003-06-17 Crompton Corporation Viscosity growth inhibition in oil additive concentrates

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2751352A (en) * 1951-08-23 1956-06-19 Shell Dev Magnetic fluids

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2751351A (en) * 1952-07-05 1956-06-19 Exxon Research Engineering Co Complex ester base lubricating grease compositions
US3047507A (en) * 1960-04-04 1962-07-31 Wefco Inc Field responsive force transmitting compositions
US3367872A (en) * 1967-02-15 1968-02-06 Union Oil Co Electroviscous fluid composition

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2751352A (en) * 1951-08-23 1956-06-19 Shell Dev Magnetic fluids

Also Published As

Publication number Publication date
DE69003434D1 (de) 1993-10-28
EP0395359A1 (de) 1990-10-31
JPH02284992A (ja) 1990-11-22
DE69003434T2 (de) 1994-01-20

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