JPH04161497A - Electroviscous liquid - Google Patents
Electroviscous liquidInfo
- Publication number
- JPH04161497A JPH04161497A JP28811390A JP28811390A JPH04161497A JP H04161497 A JPH04161497 A JP H04161497A JP 28811390 A JP28811390 A JP 28811390A JP 28811390 A JP28811390 A JP 28811390A JP H04161497 A JPH04161497 A JP H04161497A
- Authority
- JP
- Japan
- Prior art keywords
- liquid
- silica particles
- wet silica
- electrorheological
- electrically insulating
- 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.)
- Pending
Links
- 239000007788 liquid Substances 0.000 title claims abstract description 58
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 62
- 239000002245 particle Substances 0.000 claims abstract description 36
- 125000003709 fluoroalkyl group Chemical group 0.000 claims abstract description 8
- 229920005645 diorganopolysiloxane polymer Polymers 0.000 claims abstract description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- 229920002545 silicone oil Polymers 0.000 claims description 8
- GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical compound [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 claims description 3
- 239000000725 suspension Substances 0.000 abstract description 7
- 230000000694 effects Effects 0.000 description 24
- 239000000377 silicon dioxide Substances 0.000 description 14
- 150000002500 ions Chemical class 0.000 description 7
- -1 "Nip Seal AQ-8" Chemical compound 0.000 description 6
- 229910001415 sodium ion Inorganic materials 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 230000005684 electric field Effects 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 239000003921 oil Substances 0.000 description 4
- 239000004205 dimethyl polysiloxane Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 3
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 description 3
- 235000019353 potassium silicate Nutrition 0.000 description 3
- 238000004062 sedimentation Methods 0.000 description 3
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 3
- 230000008719 thickening Effects 0.000 description 3
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 229910052731 fluorine Inorganic materials 0.000 description 2
- 125000001153 fluoro group Chemical group F* 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 230000033001 locomotion Effects 0.000 description 2
- 238000006116 polymerization reaction Methods 0.000 description 2
- 229920001296 polysiloxane Polymers 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- 239000011973 solid acid Substances 0.000 description 2
- PYGXAGIECVVIOZ-UHFFFAOYSA-N Dibutyl decanedioate Chemical compound CCCCOC(=O)CCCCCCCCC(=O)OCCCC PYGXAGIECVVIOZ-UHFFFAOYSA-N 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical group [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- KPUWHANPEXNPJT-UHFFFAOYSA-N disiloxane Chemical compound [SiH3]O[SiH3] KPUWHANPEXNPJT-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000013213 extrapolation Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 239000010720 hydraulic oil Substances 0.000 description 1
- 125000001183 hydrocarbyl group Chemical group 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000002480 mineral oil Substances 0.000 description 1
- 235000010446 mineral oil Nutrition 0.000 description 1
- 239000012188 paraffin wax Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 125000001436 propyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 238000001694 spray drying Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
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
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野コ
本発明は湿式シリカ粒子が電気絶縁性液体中に分散せれ
てなる電気粘性液体に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrorheological liquid comprising wet silica particles dispersed in an electrically insulating liquid.
［従来の技術および発明が解決しようとする課題］
外部からの電圧の印加により粘度が変化する液体は、動
力伝達、衝撃吸収、バルブ効果などの作用を示すので近
年注目されている。[Prior Art and Problems to be Solved by the Invention] Liquids whose viscosity changes when an external voltage is applied have attracted attention in recent years because they exhibit functions such as power transmission, shock absorption, and valve effects.
こうした電界により増粘作用を示す液体を総称して電気
粘性液体というが、中でもクラッチ、エンジンマウント
、ショックアブソーバ−などの実用度の高い用途に耐え
るためには、低い電圧により著しく降伏値の増大する液
体が必要とされる。Liquids that exhibit a thickening effect due to electric fields are collectively called electrorheological liquids, but in order to withstand highly practical applications such as clutches, engine mounts, and shock absorbers, the breakdown value must be significantly increased by lower voltages. liquid is required.
こうした液体は現在まで種々のものが提唱されている。Various types of such liquids have been proposed up to now.
例えば、シリカ、アルミナ、タルク等の無機質多孔性粒
子を電気絶縁性液体に分散させたものが代表的である。For example, a typical example is one in which inorganic porous particles such as silica, alumina, and talc are dispersed in an electrically insulating liquid.
これらは何れも粒子表面に吸着している水による電気二
重層の形成により、外部の電界に対して粒子が配向し、
粘度が増大する（より詳しくは降伏値をもつビンガム流
体に転移する）と説明されている（以下この効果をＷｌ
ｎｓｌｏｖ効果と称す）。とりわけシリカを用いた電気
粘性液体は、使用温度が制約される（約１０℃〜８０℃
）、周辺機器への摩耗性がある、粒子の沈降性がある等
の不利もあるが、シリカの工業的供給性９品種改良性が
豊かであり、常温付近で使用され摺動運動の少ない機器
などの特定の使用分野では有用と思われる。シリカを用
いた電気粘性液体は米国特許第３．０４７．５０７号公
報、特開昭６１−４４９９８号公報に開示されているが
、これらは、何れもＩＦＩｎｓｌｏｗ効果の程度が低く
、実用上満足できるものではなかった。In all of these, particles are oriented in response to an external electric field due to the formation of an electric double layer due to water adsorbed on the particle surface.
It is explained that the viscosity increases (more specifically, it transforms into a Bingham fluid with a yield value) (hereinafter this effect will be referred to as Wl
(referred to as the nslov effect). In particular, electrorheological liquids using silica are limited in operating temperature (approximately 10°C to 80°C).
), there are disadvantages such as abrasiveness to peripheral equipment and sedimentation of particles, but silica's industrial supplyability 9 It is easy to improve varieties, and it is suitable for equipment that is used near room temperature and has little sliding movement. It may be useful in certain fields of use, such as Electrorheological liquids using silica are disclosed in U.S. Pat. It wasn't something.
本発明者は上記問題点を解消するために鋭意検討した結
果、上記のような電気粘性液体において、特定の湿式シ
リカを使用すれば上記問題点は大幅に解消されることを
見出し本発明に到達した。すなわち、本発明の目的は、
低い電圧により、著しく降伏値が増大する等電気粘性液
体として優れた特性を有する電気粘性液体を提供するに
ある。As a result of intensive studies to solve the above-mentioned problems, the present inventor found that the above-mentioned problems could be largely solved by using a specific wet silica in the electrorheological liquid as described above, and arrived at the present invention. did. That is, the purpose of the present invention is to
It is an object of the present invention to provide an electrorheological liquid having excellent properties as an electrorheological liquid, such as a yield value which increases significantly with a low voltage.
［課題の解決手段とその作用コ
かかる本発明は、
湿式シリカ粒子が電気絶縁性液体中に分散されてなる電
気粘性液体において、該湿式シリカ粒子の平均粒径が１
０〜５００μｍであり、該湿式シリカ粒子の４重量％懸
濁水のｐＨ（水素イオン濃度）が６．５以下であること
を特徴とする電気粘性液体に関する。[Means for Solving the Problems and Their Effects] The present invention provides an electrorheological liquid in which wet silica particles are dispersed in an electrically insulating liquid, wherein the average particle size of the wet silica particles is 1.
The present invention relates to an electrorheological liquid having a particle diameter of 0 to 500 μm and a pH (hydrogen ion concentration) of 4% by weight suspension of wet silica particles of 6.5 or less.
これについて説明するに、本発明に使用される湿式シリ
カ粒子は高いＨｎｓｌｏｗ効果を与えるために必要な成
分である。かかる湿式シリカ粒子は水ガラスを原料にし
て湿式下で酸を加えることによりシリカを形成させる方
法により製造されたシリカ粒子である。これらの湿式シ
リカ粒子は、粒子の表面にＷｌｎｓｌｏｖ効果発現に好
適な吸着水の層があること、および好適な粒子径を何す
ること等の理由により、電気粘性液体の分散相として好
適である。この平均粒径は１０〜５００μｍの範囲内で
あり、好ましくは５０〜２００μｍの範囲内である。こ
れは、粒子径が１０μｍ未溝であると粒子間の配向力は
大きい反面、粒子間力が小さくなり、十分な粘性が得ら
れなく、逆に５００μｍより大きくなると、配向力が鈍
り粘性効果が減少するとともに、粒子の大きさそのもの
の弊害が無視できなくなるためである。粒子の形状に関
してはなるべく真球状のものが好ましい。真球からの変
形度が大きいと、粒子間の有効接触面積が小さくなり、
凝集力が弱まるためである。粒径分布については、より
狭いほど好ましい。粒径分布が狭いほど粒子の配向力が
均一なため、効率のよい増粘効果が得られるためである
。なるべく真球状で粒径分布の狭いシリカ粒子の製造法
としては種々考えられるが、主に乾燥工程を工夫するこ
とで得られる。例えばスプレードライ法などが好適であ
る。To explain this, the wet silica particles used in the present invention are a necessary component to provide a high Hnslow effect. Such wet silica particles are silica particles manufactured by a method of forming silica by adding acid under wet conditions using water glass as a raw material. These wet silica particles are suitable as a dispersed phase of an electrorheological liquid because of the presence of an adsorbed water layer on the surface of the particles suitable for expressing the Wlnslov effect, and the suitable particle size. This average particle size is within the range of 10 to 500 μm, preferably within the range of 50 to 200 μm. This is because if the particle size is 10 μm without grooves, the orientation force between the particles is large, but on the other hand, the interparticle force becomes small and sufficient viscosity cannot be obtained.On the other hand, when the particle size is larger than 500 μm, the orientation force becomes dull and the viscosity effect is reduced. This is because as the particle size decreases, the adverse effects of the particle size itself cannot be ignored. Regarding the shape of the particles, it is preferable that the particles be truly spherical. When the degree of deformation from a true sphere is large, the effective contact area between particles becomes small,
This is because the cohesive force is weakened. Regarding the particle size distribution, the narrower the particle size distribution, the more preferable it is. This is because the narrower the particle size distribution, the more uniform the orientation force of the particles, and the more efficient the thickening effect can be obtained. Various methods can be considered for producing silica particles that are as perfectly spherical as possible and have a narrow particle size distribution, but they can be obtained mainly by devising a drying process. For example, a spray dry method is suitable.
一方、上記の性状の他に湿式シリカ粒子中のイオン量も
Ｗｉｎｓｌｏｖ効果の大小を決める重要な因子である。On the other hand, in addition to the above-mentioned properties, the amount of ions in the wet silica particles is also an important factor that determines the magnitude of the Winslov effect.
これについては定説がないが、発明者らは次のように推
測している。シリカ中に含まれるイオンの主なものはナ
トリウムイオンであるが、これは主に原料の水ガラス中
に含まれる不純物である固体酸を中和するために用いた
ナトリウムイオンの過剰分である。よってこのナトリウ
ムイオン量の大小によってシリカの液性が決定される。Although there is no established theory regarding this, the inventors speculate as follows. The main ion contained in silica is sodium ion, and this is mainly an excess of sodium ion used to neutralize solid acid, which is an impurity contained in the raw water glass. Therefore, the liquid properties of silica are determined by the amount of sodium ions.
発明者らの実験によれば、シリカ中の遊離しているイオ
ンの存在は粒子の配向の時間的遅延をもたらすと考えら
れる。端的な現象例としては、遊離イオンを含む湿式シ
リカを分散させた電気粘性液体に電界をかけ、一定ある
いは可変せん断速度でのせん断応力には不安定さが生じ
る。ランダムな状態の粒子が配向するのに要する時間が
、遊離イオンを含む粒子の場合、イオンの移動に時間が
かかるために、長くなり、その結果、動的な状況では不
安定さを生じるものと考えられる。このため、有効なＷ
ｉｎｓｌｏｗ効果を与える湿式シリカ粒子としてはナト
リウムイオン等の遊離イオン量の少ないものが好適であ
る。純粋の湿式シリカ粒子の液性は通常酸性側にある。According to the inventors' experiments, it is believed that the presence of free ions in silica causes a time delay in particle orientation. A simple example of this phenomenon is when an electric field is applied to an electrorheological liquid in which wet silica containing free ions is dispersed, and instability occurs in the shear stress at a constant or variable shear rate. The time required for random particles to orient is longer for particles containing free ions because the ions take longer to move, resulting in instability in dynamic situations. Conceivable. Therefore, the effective W
Wet silica particles that provide the inslow effect are preferably those containing a small amount of free ions, such as sodium ions. The liquid properties of pure wet silica particles are usually on the acidic side.
すなわち、酸性側のシリカが好適である。液性の基準と
しては該シリカ粒子を４重量％懸濁水の状態でｐＨを測
った場合、６．５以下であり、５．５以下であることが
より好適である。６．５を越える場合は有効なＷｌｎｓ
ｌｏｗ効果が与えられない。このような液性を有する湿
式シリカ粒子を得るためには、過剰のナトリウムイオン
を極力除去するか、原料の水ガラスに固体酸の含有量の
極めて少ない純粋なものを使用する必要がある。That is, acidic silica is preferred. As a criterion for liquid property, when the pH is measured in a state where the silica particles are suspended in water at 4% by weight, it is 6.5 or less, and more preferably 5.5 or less. Valid Wlns if over 6.5
No low effect is given. In order to obtain wet silica particles having such liquid properties, it is necessary to remove excess sodium ions as much as possible, or to use pure water glass as a raw material with an extremely low solid acid content.
本発明で使用する湿式シリカ粒子は以上のような性状を
満足するものであればよく、特に限定されるものではな
い。これらは市販の湿式シリカ粒子から選択することも
でき、例えば、日本シリカニ業株式会社製の商品である
“ニップシールＡＱ−８”等が該当する。The wet silica particles used in the present invention are not particularly limited as long as they satisfy the above properties. These can also be selected from commercially available wet silica particles, such as "Nip Seal AQ-8", a product manufactured by Nippon Silikani Gyo Co., Ltd.
さて本発明の電気粘性液体は上記のような湿式シリカ粒
子を電気絶縁性液体中に分散させてなるものであるが、
電気絶縁性液体は、常温で液状であり、電気絶縁性を示
すものであればよく、特に限定されない。かかる電気絶
縁性液体としては、鉱油、セバシン酸ジブチル、塩化パ
ラフィン、フッ素オイル、シリコーン油等が挙げられる
。Now, the electrorheological liquid of the present invention is made by dispersing wet silica particles as described above in an electrically insulating liquid.
The electrically insulating liquid is not particularly limited as long as it is liquid at room temperature and exhibits electrically insulating properties. Such electrically insulating liquids include mineral oil, dibutyl sebacate, chlorinated paraffin, fluorine oil, silicone oil, and the like.
これらの中で、電気絶縁性が大きいこと、温度による粘
度変化が小さいこと等の点でシリコーン油が好ましい。Among these, silicone oil is preferred because of its high electrical insulation properties and small change in viscosity due to temperature.
かかるシリコーン油としては以下の式で示される化学構
造を有する液状ジオルガノポリシロキサンが例示される
。An example of such a silicone oil is a liquid diorganopolysiloxane having a chemical structure represented by the following formula.
ＲＲＲ
（式中、Ｒは、メチル基、エチル基、プロピル基等のア
ルキル基、フェニル基等のアリール基で示される１価炭
化水素基である。Ｒの内の３０％以上はメチル基である
ことが好ましい。また、重合度ｎは特に限定されないが
、実用的粘度範囲の点でｎは１０００以下が好ましく、
より好ましくは１００以下である。このような構造をも
つシリコーン油は東し・ダウコーニング・シリコーン株
式会社製” ５Ｈ２００”を始めとして種々の市販品が
ある。RRR (wherein, R is a monovalent hydrocarbon group represented by an alkyl group such as a methyl group, ethyl group, or propyl group, or an aryl group such as a phenyl group. 30% or more of R is a methyl group) In addition, the degree of polymerization n is not particularly limited, but in terms of a practical viscosity range, n is preferably 1000 or less,
More preferably it is 100 or less. There are various commercially available silicone oils having such a structure, including "5H200" manufactured by Toshi Dow Corning Silicone Co., Ltd.
さらにシリコーン油の内で、より高いＷＩｎｓｌＯＷ効
果を助長し、かつ比重差による粒子の沈降を抑える効果
のある種類のものとしては、構造中にフルオロアルキル
基を含むジオルガノポリシロキサンが好ましい。具体的
には下記の構造式で示される。Among silicone oils, diorganopolysiloxanes containing fluoroalkyl groups in their structure are preferred as silicone oils that promote a higher WInslOW effect and are effective in suppressing particle sedimentation due to differences in specific gravity. Specifically, it is shown by the following structural formula.
ＲＲ２ＲＲ
ＲＲＲＲ
（式中、Ｒは前記と同じであり、Ｒ２は炭素数１０以下
のフルオロアルキル基、ｍおよびｐは１０００以下の整
数である）。RR2RR RRRR (wherein R is the same as above, R2 is a fluoroalkyl group having 10 or less carbon atoms, and m and p are integers of 1000 or less).
炭素数１０以下のフルオロアルキル基は、その構造は特
に限定されないが、合成のしやすさ等から３．３．３−
）リフルオロプロピル基が好ましい。！ｌｌｎｓｌｏｗ
効果を顕著に助長させるためには、１分子中のフルオロ
アルキル基の含有率が３０モル％以上であることが好ま
しい。また材料供給性、経済性の点ではＲの内の３０％
以上はメチル基であることが好ましい。また、重合度ｍ
は特に限定されないが、実用的粘度範囲の点でｍは１０
００以下が好ましく、より好ましくは１００以下である
。フルオロアルキル基がＷｌｎｓｌｏｗ効果の助長効果
を与える機構は明らかになっていないが、電気陰性原子
のフッ素原子と電気陽性原子のケイ素とが分子内に適当
な距離をおいて共存することから分子内に強い双極子が
生じ、この双極子が湿式シリカ粒子上の電気二重層と接
したときに二重層の分極を促進するものと推定できる。The structure of the fluoroalkyl group having 10 or less carbon atoms is not particularly limited, but 3.3.3-
) Lifluoropropyl group is preferred. ! llnslow
In order to significantly enhance the effect, it is preferable that the content of fluoroalkyl groups in one molecule is 30 mol% or more. In addition, in terms of material supplyability and economic efficiency, 30% of R
The above group is preferably a methyl group. Also, the degree of polymerization m
is not particularly limited, but m is 10 in terms of a practical viscosity range.
It is preferably 00 or less, more preferably 100 or less. The mechanism by which the fluoroalkyl group promotes the Wlnslow effect is not clear, but since the electronegative fluorine atom and the electropositive silicon atom coexist at an appropriate distance within the molecule, It can be assumed that a strong dipole is generated and that when this dipole comes into contact with the electric double layer on the wet silica particles, it promotes the polarization of the double layer.
さらにフッ素原子が含まれる液体は比重が大きくなる傾
向にあるため、シリカ粒子の沈降性を抑える効果が同時
に生まれる。このようなフルオロアルキル基を含むジオ
ルガノポリシロキサンは東し・ダウコーニング・シリコ
ーン株式会社製”ＦＳ１２６５”を始めとした市販品を
利用できる。Furthermore, since liquids containing fluorine atoms tend to have a high specific gravity, they also have the effect of suppressing the sedimentation of silica particles. As the diorganopolysiloxane containing such a fluoroalkyl group, commercially available products such as "FS1265" manufactured by Toshi Dow Corning Silicone Co., Ltd. can be used.
本発明による電気粘性液体は、上記のような湿式シリカ
粒子を上記のような電気絶縁性液体に分散させてなるも
のであるが、その分散量は０．１〜５０重量％の範囲内
であり、好ましくは１０〜４０重量％の範囲内である。The electrorheological liquid according to the present invention is obtained by dispersing wet silica particles as described above in an electrically insulating liquid as described above, and the amount of the dispersion is within the range of 0.1 to 50% by weight. , preferably within the range of 10 to 40% by weight.
これは０、１重量％未溝になると十分な増粘効果が得ら
れなく、また５０重量％を越えると電気粘性液体の粘度
が著しく増大して実用上不向きであるからである。This is because if the amount is 0.1% by weight without grooves, a sufficient thickening effect cannot be obtained, and if it exceeds 50% by weight, the viscosity of the electrorheological liquid increases significantly, making it unsuitable for practical use.
以上のような本発明の電気粘性液体は、例えば、常温付
近で使用され、摺動運動の少ない機器などの特定の機器
用作動油として有用である。The electrorheological liquid of the present invention as described above is useful, for example, as a hydraulic oil for specific equipment such as equipment that is used at around room temperature and has little sliding motion.
［実施例コ
以下、実施例、比較例にて本発明の詳細な説明する。実
施例中、部とあるのは重量部を意味し、粘度は２５℃に
おける値であり、Ｃ８はセンチストークスである。[Example] The present invention will be explained in detail below using Examples and Comparative Examples. In the examples, parts mean parts by weight, viscosity is the value at 25°C, and C8 is centistokes.
なお、電気粘性効果の測定は次の方法によった。The electrorheological effect was measured by the following method.
内径４２１嘗のアルミ製カップに被験液体を入れ、その
中に径４０１１１Ｊ 長さ６０箇嘗のアルミ製ロータ
ーを沈めた。この円筒型セルを垂直方向にセットし、カ
ップを４０秒かけてせん断速度（Ｄ）ゼロから３３０８
りまで線形に加速した。A test liquid was placed in an aluminum cup with an inner diameter of 421 mm, and an aluminum rotor with a diameter of 40111 J and a length of 60 mm was submerged therein. This cylindrical cell was set vertically, and the shear rate (D) was changed from zero to 3308 m over 40 seconds.
It accelerated linearly until the end.
この時のローターにかかるトルクをトルクセンサーで検
知し、これをせん断応力（Ｓ）に換算してＸ−Ｙレコー
ダー上にＤ対Ｓ曲線を描かせた。さらにローターを電気
的に接地し、カップ側に直流電圧を印加して同様のＤ対
Ｓ曲線を描かせ、直線部分のＳ軸への外挿点をもって、
この電界強度での降伏値とした。また、せん断応力の安
定性および湿式シリカ粒子の沈降性を調べた。The torque applied to the rotor at this time was detected by a torque sensor, converted into shear stress (S), and a D vs. S curve was drawn on an X-Y recorder. Furthermore, the rotor is electrically grounded, a DC voltage is applied to the cup side, a similar D vs. S curve is drawn, and the point of extrapolation of the straight line portion to the S axis is
The yield value was determined at this electric field strength. In addition, the stability of shear stress and the settling property of wet silica particles were investigated.
実施例１
平均粒径が１００μｍであり、４重量％の懸濁水のｐＨ
が５．５〜６．５である湿式シリカ粒子［日本シリカニ
業株式会社製、商品名ニップシールＡＱ−８３１５部を
粘度１００Ｃ８の脂肪族炭化水素系油口日本石油株式会
社製、ゴム膨潤油３号コ８５部に加えて攪拌することに
より、湿式シリカ粒子が脂肪族炭化水素系油中に分散し
た懸濁液である電気粘性液体を得た。Example 1 The average particle size was 100 μm and the pH of the suspension water was 4% by weight.
is 5.5 to 6.5 [manufactured by Nippon Silikani Gyo Co., Ltd., trade name: Nip Seal AQ-8315 parts] is an aliphatic hydrocarbon-based oil with a viscosity of 100C8, manufactured by Nippon Oil Co., Ltd., rubber swelling oil No. 3. By adding 85 parts of silica and stirring, an electrorheological liquid, which is a suspension of wet silica particles dispersed in an aliphatic hydrocarbon oil, was obtained.
次いで、この液体の電気粘性効果の測定を行った。これ
らの測定結果を後記する第１表および第１図に示した。Next, the electrorheological effect of this liquid was measured. The results of these measurements are shown in Table 1 and FIG. 1 below.
実施例２
平均粒径が１００μｍであり、４重量％の懸濁水のｐＨ
が５．５〜６．５である湿式シリカ粒子［日本シリカニ
業株式会社製、商品名ニップシールＡＱ−８］ １５部
を粘度１００Ｃ８の両末端トリメチルシロキシ基封鎖ポ
リジメチルシロキサン８５部に加えて攪拌することによ
り、湿式シリカがポリジメチルシロキサン中に均一に分
散した電気粘性液体を得た。Example 2 The average particle size was 100 μm and the pH of the suspension water was 4% by weight.
is 5.5 to 6.5 [manufactured by Nippon Silikani Gyo Co., Ltd., trade name Nip Seal AQ-8] 15 parts are added to 85 parts of polydimethylsiloxane with a viscosity of 100C8 and end-blocked with trimethylsiloxy groups at both ends, and stirred. As a result, an electrorheological liquid in which wet silica was uniformly dispersed in polydimethylsiloxane was obtained.
次いで、この液体の電気粘性効果の測定を行ったところ
後記する第１表に示す測定結果を得た。Next, the electrorheological effect of this liquid was measured, and the measurement results shown in Table 1 below were obtained.
実施例３
実施例２において、粘度１ｏｏｃｓポリジメチルシロキ
サンの替わりに粘度３００Ｃ８の両末端トリメチルシロ
キシ基封鎖ポリ（メチル・３゜３．３−）リフルオロプ
ロピル）シロキサンを使用した以外は、実施例２と同様
にして電気粘性液体を得た。この液体の特性を実施例２
と同様にして測定した。これらの測定結果を後記する第
１表に示した。Example 3 Example 2 except that poly(methyl-3°3.3-)lifluoropropyl)siloxane with a viscosity of 300C8 and end-blocked with trimethylsiloxy groups at both ends was used instead of polydimethylsiloxane with a viscosity of 1oocs. An electrorheological liquid was obtained in the same manner. Example 2 shows the characteristics of this liquid.
It was measured in the same manner. The results of these measurements are shown in Table 1 below.
比較例１
実施例２において、平均粒径が１００μｍの湿式シリカ
粒子の替わりに、平均粒径が４μｍであり、４重量％の
懸濁水のｐＨが５．ｉ５〜６．５である湿式シリカ粒子
［日本シリカニ業株式会社製、商品名ニップシールＬ−
３００１を使用した以外は実施例２と同様にして電気粘
性液体を得た。この液体の特性を実施例２と同様にして
測定した。Comparative Example 1 In Example 2, instead of wet silica particles having an average particle size of 100 μm, the average particle size was 4 μm, and the pH of the 4% by weight suspension water was 5. Wet silica particles with i5 to 6.5 [manufactured by Nippon Silikani Gyo Co., Ltd., trade name Nip Seal L-]
An electrorheological liquid was obtained in the same manner as in Example 2 except that 3001 was used. The properties of this liquid were measured in the same manner as in Example 2.
これらの測定結果を第１表に併記した。These measurement results are also listed in Table 1.
比較例２
実施例２において、平均粒径が１００μｍの湿式シリカ
の替わりに、平均粒径８５μｍであり、４重量％懸濁水
のｐＨがｉｏ、ｏ〜１１．０である湿式シリカ粒子［日
本シリカニ業株式会社製。Comparative Example 2 In Example 2, instead of wet silica particles having an average particle size of 100 μm, wet silica particles having an average particle size of 85 μm and a pH of 4% suspension water of io, o to 11.0 [Nippon Silica Manufactured by Gyo Co., Ltd.
商品名ニップシールＮＡ−Ｒ］を使用した以外は実施例
２と同様にして電気粘性液体を得た。An electrorheological liquid was obtained in the same manner as in Example 2 except that Nip Seal NA-R (trade name) was used.
次いでこの液体の電気粘性効果の測定を行ったところ、
後記する第１表および第２図に示す結果を得た。Next, we measured the electrorheological effect of this liquid, and found that
The results shown in Table 1 and FIG. 2, which will be described later, were obtained.
第１表
［発明の効果コ
本発明の電気粘性液体は、湿式シリカ粒子の平均粒径が
１０〜５００μｍであり、該湿式シリカ粒子の４重量％
懸濁水の１）Ｈ（水素イオン濃度）が６．５以下である
ので、低い電圧により著しく降伏値が増大する、せん断
安定性に優れる等優れた電気粘性効果を発現するという
特徴第１図は実施例１で得られた電気粘性液体のせん断
速度とせん断応力の関係を示したものであり、第２図は
、比較例２で得られた電気粘性液体のせん断速度とせん
断応力の関係を示したものである。Table 1 [Effects of the Invention] The electrorheological liquid of the present invention has wet silica particles having an average particle size of 10 to 500 μm, and 4% by weight of the wet silica particles.
1) Since the H (hydrogen ion concentration) of the suspended water is 6.5 or less, it exhibits excellent electrorheological effects such as a marked increase in yield value with low voltage and excellent shear stability. Figure 2 shows the relationship between the shear rate and shear stress of the electrorheological liquid obtained in Example 1, and Figure 2 shows the relationship between the shear rate and shear stress of the electrorheological liquid obtained in Comparative Example 2. It is something that
Claims (1)
る電気粘性液体において、該湿式シリカ粒子の平均粒径
が１０〜５００μｍであり、該湿式シリカ粒子の４重量
％懸濁水のｐＨ（水素イオン濃度）が６．５以下である
ことを特徴とする電気粘性液体。 ２ 電気絶縁性液体がシリコーン油である特許請求の範
囲第１項記載の電気粘性液体。 ３ シリコーン油が、フルオロアルキル基を含むジオル
ガノポリシロキサンである特許請求の範囲第２項記載の
電気粘性液体。[Scope of Claims] 1. An electrorheological liquid in which wet silica particles are dispersed in an electrically insulating liquid, wherein the wet silica particles have an average particle diameter of 10 to 500 μm, and the wet silica particles contain 4% by weight of the wet silica particles. An electrorheological liquid characterized in that the pH (hydrogen ion concentration) of turbid water is 6.5 or less. 2. The electrorheological liquid according to claim 1, wherein the electrically insulating liquid is silicone oil. 3. The electrorheological liquid according to claim 2, wherein the silicone oil is a diorganopolysiloxane containing a fluoroalkyl group.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28811390A JPH04161497A (en) | 1990-10-25 | 1990-10-25 | Electroviscous liquid |
| EP91118246A EP0482663A1 (en) | 1990-10-25 | 1991-10-25 | Electroviscous fluid |
| CA 2054267 CA2054267A1 (en) | 1990-10-25 | 1991-10-25 | Electroviscous fluid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28811390A JPH04161497A (en) | 1990-10-25 | 1990-10-25 | Electroviscous liquid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04161497A true JPH04161497A (en) | 1992-06-04 |
Family
ID=17725972
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28811390A Pending JPH04161497A (en) | 1990-10-25 | 1990-10-25 | Electroviscous liquid |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0482663A1 (en) |
| JP (1) | JPH04161497A (en) |
| CA (1) | CA2054267A1 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2210893A (en) * | 1987-10-12 | 1989-06-21 | American Cyanamid Co | Electrorheological fluids |
| DE68908469T2 (en) * | 1988-05-12 | 1993-12-09 | Toa Nenryo Kogyo Kk | Electrorheological fluids. |
-
1990
- 1990-10-25 JP JP28811390A patent/JPH04161497A/en active Pending
-
1991
- 1991-10-25 EP EP91118246A patent/EP0482663A1/en not_active Withdrawn
- 1991-10-25 CA CA 2054267 patent/CA2054267A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| EP0482663A1 (en) | 1992-04-29 |
| CA2054267A1 (en) | 1992-04-26 |
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