JPH0428793A - Electric viscous fluid composition - Google Patents

Abstract

PURPOSE:To obtain the title composition giving large shear stress even by application of a relatively weak electric field with low current density by dispersing disperse phase particles consisting of a specific sulfonated polymer having sulfonate group-substituted aromatic ring in an electrical insulating dispersion medium. CONSTITUTION:The objective composition can be obtained by dispersing (I) disperse phase particles consisting of a sulfonated polymer prepared by sulfonating (A) 100 pts.wt. of a crosslinked polymer from a monomer mixture comprising an aromatic vinyl compound and polyvinyl compound and, if needed, a minor amount of other vinyl compound using (B) >=500 pts.wt. of acid in an electrical insulating dispersion medium. The present composition is excellent in the stability with time of both shear stress and current density produced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to electrorheological fluid compositions. More specifically, it is an electrorheological property that generates a large shear force even when a relatively weak electric field is applied, and that the current density that flows at that time is small and does not occur and has excellent stability over time of the shear force and current density. The present invention relates to fluid compositions.

(Prior Art) An electrorheological fluid is a fluid obtained by dispersing or suspending solid particles in an insulating dispersion medium, and its rheological or flow properties can be changed to viscoplastic type by applying an electric field change. It is a fluid whose properties change, and its viscosity generally increases significantly when an external electric field is applied, inducing a large shear force. It is known as a fluid that exhibits the so-called Winslow effect. Since the Winslow effect is characterized by quick response, attempts have been made to apply electrorheological fluids to clutches, dampers, brakes, shock absorbers, actuators, and the like.

Conventionally, electrorheological fluid compositions include silicone oil,
It is known that solid particles such as cellulose, starch, soybean casein, silica gel, polystyrene ion exchange resin, cross-linked polyacrylate, etc. are dispersed in insulating oil such as diphenyl chloride or trans oil.

However, electrorheological fluid compositions using cellulose, starch, or soybean casein as a dispersed phase have the problem that the shear force obtained when an electric field is applied is small, and polyacrylate crosslinked products are used as a dispersed phase. The problem with electrorheological fluid compositions was that a practically sufficient shear force could not be induced by simply applying a relatively weak electric field.

In addition, an electrorheological fluid composition using an alkali metal salt type ion exchange resin of polystyrene sulfonic acid, which is one of the polystyrene-based ion exchange resins, as a dispersed phase has a large shear force even when a relatively weak electric field is applied. However, there were problems in that the current density flowing at that time was large, and the shear force and current density, which were not generated, were poor in stability over time.

On the other hand, it is also possible to use particles of a sulfonated polymer obtained by sulfonating a crosslinked polymer mainly composed of styrene and divinylbenzene using sulfuric acid as a sulfonating agent as a dispersed phase of an electrorheological fluid composition. , such an electrorheological fluid composition has a high current density even if a large shear force is generated by applying a relatively weak electric field, and the shear force and current density are stable over time without being generated. The problem was that it lacked sex.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned problems that conventional electrorheological fluid compositions have.

Therefore, it is an object of the present invention to generate a large shearing force even when a relatively weak electric field is applied, and to reduce the current density flowing at that time, and also to maintain stability over time of the shearing force and the current density. An object of the present invention is to provide an excellent electrorheological fluid composition.

(Means and effects for solving the problems) The present invention provides a composition in which dispersed phase particles made of a sulfonated polymer having an aromatic ring substituted with a sulfonic acid group are dispersed in an insulating dispersion medium. The sulfonated polymer is a polymerized crosslinked product (I ) to polymerize crosslinked product (
The present invention relates to an electrorheological fluid composition obtained by sulfonating 100 parts by weight of I.) with 500 parts by weight or more of chloroKfa.

The average particle diameter of the dispersed phase particles used in the present invention is 0.1 to
It is preferably in the range of 100 μm.

In the electrorheological fluid composition of the present invention, as the particle size of the dispersed phase becomes smaller, the shear force obtained when an electric field is applied to the prepared electrorheological fluid composition tends to become smaller. If the average particle diameter of the electrorheological fluid composition is less than 0.1 μm, a problem may occur in that a large shear force cannot be obtained when an electric field is applied to the prepared electrorheological fluid composition. Also, the average particle diameter of the dispersed phase particles is 1
If it exceeds 00 μm, the shear path force value obtained when a certain electric field is applied to the prepared electrorheological fluid composition becomes irregular and may be difficult to stabilize.

The sulfonic acid group referred to in the present invention refers to a group that liberates a cation in the presence of a polar solvent such as water and becomes a sulfonic acid ion itself. There are no restrictions.

The sulfonated polymer constituting the dispersed phase particles used in the present invention is a monomer mixture containing a vinyl aromatic compound (a) and a polyvinyl compound (b) as main components, with other vinyl compounds (c) added as necessary. Polymerized crosslinked product (I) of (A)
), but it is necessary to use a specific amount of chlorosulfuric acid as the sulfonating agent. By using chlorosulfuric acid as a sulfonating agent, it is possible to obtain a sulfonated polymer suitable for dispersed phase particles that provides electrorheological fluid compositions with excellent various performances as described above.9 When a sulfonating agent is used alone, the prepared electrorheological fluid composition generates a large shear path force by applying a relatively weak electric field, but the current density flowing at that time is large and the generated A problem arises in that the shear path force and current density are poor in stability over time. In addition, licorosulfuric acid is polymerized crosslinked #(I)1
001! It is necessary to use it in a proportion of 500 parts by weight or more, and it is particularly preferable to use it in a proportion of 650 parts by weight or more. If the amount of chlorogB used is small, less than 500 parts by weight, the reactivity of the sulfonating agent in the reaction mixture decreases as sulfonation progresses, and the dispersed phase yields an electrorheological fluid composition with excellent various performances as described above. Sulfonated polymers suitable for particles are not available.

In addition, when sulfonating the crosslinked polymer (I) in the present invention, as long as chlorosulfuric acid is used as a sulfonating agent in a ratio of 500 parts by weight or more to 100 parts by weight of the crosslinked polymer (I), sulfuric acid Other sulfonating agents such as chlorosulfuric acid may be used in combination with chlorosulfuric acid.

When using other sulfonating agents in combination, the proportion of chlorosulfuric acid based on the total amount of sulfonating agents is preferably 50% by weight or more. When the proportion of chlorosulfuric acid to the total amount of sulfonate is less than 50% by weight, the prepared electrorheological fluid composition generates a large shear path force by applying a relatively weak electric field; Problems may arise in that the flowing current density is large and the shear path force is not generated and the stability of the current density is poor over time.

Other sulfonating agents that can be used in the present invention may be selected from conventionally known sulfonating agents, such as sulfuric acid, sulfur dioxide, fuming sulfuric acid, etc.
One or more types of these inner shells can be used.

The monomer mixture (A) that can be used in the present invention has a vinyl aromatic compound (a) of 50.0 to 9
9.9 mol%, polyvinyl compound (b) or 0.1 to 50
．． It is preferably in the range of 0 mol%. The composition ratio of the vinyl aromatic compound (a) is less than 50.0 mol%, and the composition ratio of the polyvinyl compound (b) is 50.0 mol%.
If it exceeds 20%, it may be difficult for sulfonation to proceed, or there may be problems such as not being able to obtain a large shear path force when an electric field is applied to the electrorheological fluid composition using the obtained particles6. , when the constituent proportion of the vinyl aromatic compound Th (a) exceeds 99.9 mol% and the constituent proportion of the polyvinyl compound (b) is less than 0.1 mol%, the polymer crosslinked product obtained by polymerization is sulfonated. When doing so, there may be a problem that particles may stick to each other.

Vinyl aromatic compound eI (
Examples of a) include vinyl aromatic hydrocarbons such as styrene, vinylnaphthalene, vinylanthracene, vinylphenanthrene; methylstyrene, ethylstyrene, propylstyrene, butylstyrene, pentylstyrene;
Monoalkylstyrene compounds such as hexylstyrene, dimethylstyrene, diethylstyrene, dipropylstyrene, methylethylstyrene, methyl-10pylstyrene, methylhexylstyrene, ethylbutylstyrene, ethylpropylstyrene, ethylhexylstyrene, propylbutylstyrene, etc. Dialkylstyrene compounds Trialkylstyrene compounds such as nitrimethylstyrene, triethylstyrene, tripropylstyrene, methyldiethylstyrene, dimethylethylstyrene, methylethyl-10pylstyrene, methyldipropylstyrene, dimethylpropylstyrene, ethyldipropylstyrene, diethylpropylstyrene ; Vinyl methylnaphthalene,
Vinyl monoalkylnaphthalene compounds such as vinyl ethylnaphthalene and vinylpropylnaphthalene; vinyldialkylnaphthalene compounds such as vinyldimethylnaphthalene, vinyldiethylnaphthalene, vinyldipropylnaphthalene, and vinylmethylethylnaphthalene; vinyltrimethylnaphthalene, and vinyltriethylnaphthalene, vinyl triethylnaphthalene, Vinyltrialkylnaphthalene compounds such as propylnaphthalene, vinylmethyldiethylnaphthalene, vinyldimethylethylnaphthalene, vinylmethylethylpropylnaphthalene; chlorostyrene, bromostyrene, fluorostyrene, chloromethylstyrene, chloroethylstyrene, chloropropylstyrene, chlorodimethylstyrene , bromomethylstyrene, bromoethylstyrene, fluoromethylstyrene, fluoroethylstyrene,
Halogenated vinyl aromatic compounds such as vinyl chloronaphthalene and vinyl bromonaphthalene; methoxystyrene,
Dimethoxystyrene, trimethoxystyrene, ethoxystyrene, jetoxystyrene, triethoxystyrene, propyloxystyrene, dipropyloxystyrene, tripropyloxystyrene, phenoxystyrene,
Methoxymethylstyrene, methoxyethylstyrene, methoxypropylstyrene, ethoxymethylstyrene, ethoxyethylstyrene, pro-oxymethylstyrene, propyloxyethylstyrene, phenoxymethylstyrene, phenoxyethylstyrene, methoxydimethylstyrene, methoxydiethylstyrene, phenoxydimethyl Styrene, phenoxydiethylstyrene, methoxychlorostyrene, methoxybromostyrene, vinylmethoxynaphthalene, vinyldimethoxynaphthalene, vinylethoxynaphthalene, vinyljethoxynaphthalene, vinylmethoxymethylnaphthalene, vinylmethoxydimethylnaphthalene, vinyldimethoxymethylnaphthalene, vinylmethoxyethylnaphthalene , vinylmethoxydiethylnaphthalene, vinyldimethoxyethylnaphthalene, vinylmethoxychloronaphthalene, vinyldimethoxychloronaphthalene, and other alkoxylated or aryloxylated vinyl aromatic compounds, among which one or two or more types are used. be able to.

Polyvinyl compound (b) that can be used in the present invention
Examples include polyvinyl aromatic hydrocarbons such as divinylbenzene, divinyltoluene, divinylxylene, divinylethylbenzene, divinyldiethylbenzene, divinylpropylbenzene, divinylnaphthalene, trivinylbenzene, trivinyltoluene, trivinylxylene, trivinylnaphthalene; ethylene; glycoldi (
meth)acrylate, diethylene glycol di(meth)
Acrylate, trimethylolpropane tri(meth)acrylate, N,N'-methylenebisacrylamide,
Polyvinyl aliphatic compounds such as diallyl maleate and diallyl adipate can be mentioned, and one or more types thereof can be used.6 The monomer mixture (A> in the present invention may include vinyl aliphatic compounds such as diallyl maleate and diallyl adipate). Aromatic compounds (a) and polyvinyl compounds (b)
A vinyl compound (c) other than the above may be blended, and its composition ratio is preferably in the range of 50 mol% or less. Examples of such other vinyl compounds (C) include olefinic hydrocarbons such as ethylene, propylene, isoprene, butadiene, vinyl chloride, and chloroprene, or halogen-substituted products thereof; methyl (meth)acrylate;
Ester compounds of unsaturated carboxylic acids such as ethyl (meth)acrylate: Vinyl ester compounds of monovalent carboxylic acids such as vinyl acetate and vinyl propionate; (meth)
Unsaturated amide compounds or their derivatives such as acrylamide, diacetone acrylamide, and methylolated (meth)acrylamide; Unsaturated cyanide compounds such as (meth)acrylonitrile and crotonitrile; Unsaturated alcohol compounds such as (meth)allyl alcohol and croton alcohol. ; Unsaturated-basic acids such as (meth)acrylic acid;
Unsaturated dibasic acids such as maleic acid, fumaric acid, and itaconic acid; monoester compounds of monohydric alcohols and unsaturated dibasic acids such as monomethyl maleate and monoallyl maleate; One or more of these can be used.

The shape of the dispersed phase particles used in the present invention is preferably spherical or ellipsoidal. If the shape of the dispersed phase particles is other than spherical or ellipsoidal, there may be problems such as not being able to obtain a large shear path force when applying an electric field to the prepared electrorheological fluid composition, or if the electric field continues to be applied. A problem may arise in that the stability over time becomes poor in a stained state.

There is no particular restriction on the method for producing the polymerization crosslink #(I) used as an intermediate for obtaining the sulfonated polymer in the present invention, and any known polymerization method may be employed.

Examples of polymerization methods include suspension polymerization, emulsion polymerization, dispersion polymerization, solution polymerization, and bulk polymerization, but spherical or ellipsoidal particles are suitable as dispersed phase particles. Suspension polymerization and emulsion polymerization are preferred because they can be easily obtained.

When a suspension polymerization method is used to produce the crosslinked polymer (I) used in the present invention, there are no particular limitations on the polymerization conditions.

Water or the like is usually used as a dispersion medium for suspension polymerization.

Dispersants for suspension polymerization are usually known such as polyvinyl alcohol, carboxymethylcellulose, ammonium salt of styrene-maleic anhydride copolymer, bentonite, sodium poly(meth)acrylate, and poly(diallylmethylammonium chloride). Things can be used.

Examples of polymerization initiators for suspension polymerization include benzoyl peroxide, tertiary butyl hydroxy peroxide, cumene peroxide, lauroyl peroxide, methyl ethyl getone peroxide,
Peroxides such as tertiary butyl perphthalate and caproyl peroxide: azobisisobutyronitrile, azobisisobutyramide, 2,2'-azobis(2,4-
Examples include azo compounds such as dimethylmaleronitrile), azobis(α-dimethylvaleronitrile), and azobis(α-methylbutyronitrile), and one or more of these may be used.

During suspension polymerization, if necessary, a known emulsion polymerization inhibitor can be used to suppress the generation of fine particles.

Suspension polymerization is usually carried out at a temperature in the range of 50 to 100°C for about 2 to 30 hours.

For suspension polymerization, for example, water and a dispersant are charged, a mixture of monomers in which a polymerization initiator is dissolved is added to the mixture under stirring, and the particle size is controlled using a disperser or stirring device. , carried out at a predetermined temperature under suspension conditions.

When emulsion polymerization is used to produce the crosslinked polymer (I) used in the present invention, there are no particular limitations on the polymerization conditions.

Water or the like is usually used as a solvent for emulsion polymerization.

As the emulsifier for emulsion polymerization, known ones such as surfactants such as sodium lauryl sulfonate and polyoxyethylene stearate can be used.

As the polymerization initiator for emulsion polymerization, commonly known initiators such as sodium persulfate and ammonium persulfate can be used.

Emulsion polymerization is usually carried out at a temperature in the range of 50 to 100°C for about 2 to 40 hours.

As the operation of emulsion polymerization, known methods such as seed polymerization method, -time charge polymerization method, monomer addition polymerization method, and emulsion addition polymerization method can be used.

To carry out the seed polymerization method, seed particles, water, an emulsifier, etc. are usually first introduced into a reaction vessel, and the mixture is uniformly dispersed with stirring, after which a part or, if necessary, all of the monomer mixture is added. Next, after heating to a predetermined temperature, a polymerization initiator is added to start the reaction. Furthermore, the remainder of the monomer mixture is added continuously or intermittently, and the process is carried out at a predetermined temperature under an emulsified state.

The polymerized crosslinked product (I) in the present invention may be a substantially non-porous polymeric crosslinked product called a gel type, and may also be a known porosity-forming agent that imparts porosity to the polymerized crosslinked product, such as a swelling agent. It may also be a porous crosslinked polymer obtained by polymerizing a monomer mixture in the coexistence of an organic solvent, a non-swelling organic solvent, a linear polymer soluble in the monomer, or a mixture thereof.

The sulfonated polymer constituting the dispersed phase particles used in the present invention is obtained by sulfonating the polymer crosslinked product (I) with the above-mentioned specific sulfonating agent and pulverizing or granulating it to an appropriate particle size. Furthermore, if particulates obtained by suspension polymerization or emulsion polymerization are used as the polymerized crosslinked product (I), sulfonated polymer particles suitable as dispersed phase particles in the present invention can be obtained by sulfonation. This is preferable because it can be done.

The sulfonation reaction can be carried out in the presence of a solvent that does not swell or swell the crosslinked polymer (I>), or can be carried out without a solvent.

The non-swelling solvent for the crosslinked polymer (I) may be any solvent that does not swell the crosslinked polymer (I) and is inert to the sulfonating agent, such as hexane, heptane, cyclohexane, Examples include aliphatic hydrocarbons such as ligroin.

The swelling solvent for the crosslinked polymer (I) may be any solvent that swells the crosslinked polymer (I) and is inert to the sulfonating agent, such as dichloroethane, trichloroethylene, tetrachloroethane, propylene. Examples include halogenated hydrocarbons such as dichloride and carbon tetrachloride; aromatic hydrocarbons such as nitrobenzene and xylene.

The amount of these solvents to be used is preferably selected within the range of 1000 parts by weight or less based on 100 parts by weight of the polymeric crosslinked product (I).

Further, in the sulfonation reaction, a sulfonation reaction catalyst such as mercury sulfate or silver sulfate, or a dehydrating agent such as phosphorus pentoxide can be used in combination with the sulfonation agent.

The sulfonation reaction is carried out at a temperature in the range of -20 to 250°C for about 0.3 to 100 hours, but the preferable conditions for sulfonation are: (1) Holding the polymerized crosslinked product (I) at a temperature of 70°C or higher for 30 minutes or more;
Examples include those that are held at a temperature of 0°C or more and less than 70°C for 0.3 to 30 hours, and then held at a temperature of 70°C or more for 30 minutes or more. Among these, method (2) is preferred in view of ease of control of the sulfonation reaction.

After the particles of the sulfonated polymer obtained by sulfonating the polymer crosslinked product (I) are separated from the sulfonating agent, they are thoroughly treated with a large amount of water to remove the acid etc. remaining in the particles. It is better to wash it.

Next, if necessary, the cation of the sulfonic acid group can be converted from a proton to a suitable cation species by a method such as neutralization or ion exchange.

The cation of the sulfonic acid group present in the sulfonated polymer constituting the dispersed phase particles used in the present invention is not particularly limited, and includes, for example, hydrogen: alkali metals such as lithium, sodium, and potassium; magnesium, calcium, etc. HA group metals such as the alkaline earth metal Nialuminum; A group metals such as tin and lead; cationic species such as transition metals such as zinc and iron, or ammonium, 814-grade ammonium, pyridinium, guadinium, etc. can be used, and one or more of these can be used.

The dispersed phase particles used in the present invention preferably contain 10 parts by weight or less of water based on 100 parts by weight of the sulfonated polymer constituting the particles.

In the electrorheological fluid composition of the present invention, a small amount of water is contained in the dispersed phase particles, so that a large shear path force is induced when an electric field is applied. However, if the water content in the sulfonated polymer particles exceeds 10 parts by weight, the dispersed phase particles may adhere to each other, or the insulation properties of the prepared electrorheological fluid composition may decrease, so that when an electric field is applied, This is undesirable because a large current may flow through it.

Insulating dispersion media that can be used in the present invention include:
There are no particular restrictions, and examples include silicone oils such as polydimethylsiloxane and polyphenylmethylsiloxane; hydrocarbons such as liquid paraffin, decane, dodecane, methylnaphthalene, dimethylnaphthalene, ethylnaphthalene, biphenyl, decalin, and partially hydrogenated triphenyl. ;
Ether compounds such as diphenyl ether: chlorobenzene, dichlorobenzene, trichlorobenzene, bromobenzene, dibromobenzene, talolonaphthalene, dichloronaphthalene, bromonaphthalene, chlorobiphenyl, dichlorobiphenyl, trichlorobiphenyl, bromobiphenyl, chlorodiphenylmethane, dichlorodiphenylmethane, trichlorodiphenylmethane , halogenated hydrocarbons such as bromodiphenylmethane, talolobucan, dichlorodecane, trichlorodecane, bromodecane, chlorododecane, dichlorododecane, bromododecane;
Halogenated diphenyl ether compounds such as chlorodiphenyl ether, dichlorodiphenyl ether, trichlorodiphenyl ether, bromodiphenyl ether;
Fluorides such as Tyfloil (manufactured by Daikin Industries) and Demnam (manufactured by Daikin Industries); ester compounds such as dioctyl phthalate, trioctyl trimellitate, and dibutyl sebacate; Or two or more types can be used.

The electrorheological fluid composition of the present invention is made by dispersing the above-mentioned dispersed phase particles in an insulating dispersion medium, and the ratio of the dispersed phase particles to the insulating dispersion medium in the composition is set to 100 parts by weight of the former. The latter is preferably in the range of 50 to 500 parts by weight. If the amount of the dispersion medium exceeds 500 parts by weight, the shear path force obtained when an electric field is applied to the prepared electrorheological fluid composition may not be sufficiently large. Furthermore, if the amount of the dispersion medium is less than 50 parts by weight, the fluidity of the prepared composition itself may be reduced, making it difficult to use it as an electrorheological fluid.

In the present invention, for example, surfactants, polymer dispersants, polymer thickeners, etc. Various additives can be added to the composition.

(Effects of the Invention) The electrorheological fluid composition of the present invention generates a large shear path force even when a relatively weak electric field is applied, and has excellent current characteristics in that the current density flowing at that time is small, and Because it has excellent stability over time in shear road force and current density, it can be effectively used in clutches, dampers, brakes, shock absorber actuators, etc.

(Examples) The present invention will be explained below with reference to Examples, but the scope of the present invention is not limited only to these Examples.

Example 1 1.2j of water was charged into a 3-hole, 4-piece rosetteable flask equipped with a stirrer, a reflux condenser, and a thermometer, and 16.0g of Kuraray Bobal PVA-205 (polyvinyl alcohol manufactured by Kuraray) was added.・After dissolving, add 250g of styrene, industrial divinylbenzene (Wako Pure Chemical Industries, Ltd.)
Co., Ltd., divinylbenzene 55% by weight, ethylstyrene 35%
A mixture consisting of 50 g (% by weight, etc.) and 4 g of azobisisobutyronitrile was added. After that, 6o o
The contents in the flask were dispersed at a stirring speed of rp+t and polymerized at 80° C. for 8 hours. The obtained solid substance was separated by P,
After thoroughly washing with water, it was dried at 80° C. for 12 hours using a hot air dryer to obtain 286 g of a spherical crosslinked polymer (hereinafter referred to as crosslinked polymer (I)).

50 g of the polymeric crosslinked product (I) and 200 g of tetrachloroethane were placed in a 2.1-liter four-separable flask equipped with a stirrer, a thermometer, and a dropping funnel, and the mixture was cooled to 0° C. using a water bath while stirring.

Next, 350 g of chlorosulfuric acid was added from the dropping funnel over 2 hours to obtain a uniform dispersion.9 Next, the reaction mixture was removed from the water bath and stirred at room temperature (20°C) for 24 hours, and then the temperature of the reaction mixture was raised to 80°C. Raise the temperature and heat for 2 hours at the same temperature.
The mixture was stirred to perform a sulfonation reaction. Thereafter, the reaction mixture was poured into water at 0°C, separated in a furnace, and washed with water and acetone.

The obtained solid was dissolved in a 10% by weight aqueous sodium hydroxide solution 2
After neutralizing with 00 ml, the solution was thoroughly washed with water. Next, it was dried at 80°C for 10 hours using a vacuum dryer, and 94g
Dispersed phase particles (hereinafter referred to as
These are called dispersed phase particles (I). ) was obtained.

Measure the average particle diameter of the obtained dispersed phase particles (I) using a particle size distribution measuring device! (■ Shimadzu Corporation, 5ALD-1000) When measured using 0 dispersed phase particles (I), the diameter was 50 μm.
The ion exchange capacity of the dispersed phase particles (4) was determined by neutralization titration and elemental analysis. When the water content in I) was measured using a Karl Fischer moisture meter (manufactured by Kyoto Denshi Kogyo ■, MPS-3P), it was found that 2
．． It was 5 parts by weight. (The average particle diameter, ion exchange capacity, and water content in the following examples and comparative examples were measured in the same manner as in this example.) Obtained dispersed phase particles (I)
30g of Shin-Etsu silicone oil KF96-20C3 (
The mixture was mixed and dispersed in 70 g of dimethyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd.) to obtain an electrorheological fluid composition of the present invention (hereinafter referred to as fluid composition (I)).

Example 2 The polymerized crosslinked product obtained in Example 1 (
50 g of I) was charged and cooled to 0° C. using a water bath while stirring. Next, 500 g of chloroVi acid was added from the dropping funnel over 2 hours to form a uniform dispersion. Next, the reaction mixture was removed from the water bath and stirred at room temperature (20°C) for 12 hours, and then the temperature of the reaction mixture was further raised to 90°C and heated and stirred at the same temperature for 3 hours to perform a sulfonation reaction. Thereafter, the reaction mixture was poured into water at 0° C., P was removed, and then washed with water and acetone.

The obtained solid was dissolved in a 10% by weight potassium hydroxide aqueous solution 33
After neutralizing with 0 ml of water, the mixture was thoroughly washed with water and then dried for 10 hours at 80°C using a vacuum dryer. Particles (referred to as particles (2)) were obtained.

The average particle diameter of the obtained dispersed phase particles (2) was measured using a particle size distribution analyzer and found to be 50 μm.The ion exchange capacity of the dispersed phase particles (2) was determined by neutralization titration and elemental analysis. When quantitatively determined, it was 5゜2■ by neutralization titration method.
Equivalent/g + 5 for elemental analysis. It was OK equivalent/g. The water content in the dispersed phase particles (2) was measured using a Karl Fischer moisture meter and was found to be 2.4 parts by weight.

The obtained dispersed phase particles (2>30g) were
(Partially hydrogenated triphenyl manufactured by Nippon Steel Chemical) 70
The electrorheological fluid composition of the present invention (
Hereinafter, this will be referred to as fluid composition (2). ) was obtained.

Example 3 1.2 Jl of water was charged into a 31-meter four-piece removable flask equipped with a stirrer, a reflux condenser, and a thermometer, and 16.0 g of Kurarayhohar PVA-205 (Lm9 polyvinyl alcohol manufactured by Rare) was added. After dissolution, a further mixture of 200 g of styrene, 70 g of chlorostyrene, 30 g of the same technical grade divinylbenzene used in Example 1 and 5 g of benzoyl peroxide was added. then 40
The contents in the flask were dispersed at a stirring speed of 0 rpm and polymerized at 80° C. for 9 hours. The obtained solid material is separated by furnace,
After thorough washing with water, it was dried at 80° C. for 12 hours using a hot air dryer to obtain 290 g of a spherical crosslinked polymer (hereinafter referred to as crosslinked polymer (2)).

Polymerized crosslinked product (2) 50t and 9 were placed in a 2J four-piece separable flask equipped with a stirrer, thermometer and dropping funnel.
250 tr of 8% by weight concentrated VA acid was charged, and the mixture was cooled to O'C using a water bath while stirring. Then chlorosulfuric acid 35
0 g was added from the dropping funnel over 2 hours to form a uniform dispersion. It is then removed from the water bath and brought to room temperature <20'C.
) After stirring for 5 hours, the temperature of the reaction mixture was further increased to 80°C.
The reaction mixture was heated to 100°C and heated and stirred at the same temperature for 13 hours to perform a sulfonation reaction.6Then, the reaction mixture was poured into water at 0°C.
After separation, it was washed with water and acetone.

The obtained solid was dissolved in a 10% by weight lithium hydroxide aqueous solution 12
After neutralizing with 0ml, the solution was thoroughly washed with water.

Next, it was dried at 80°C for 10 hours using a vacuum dryer,
Dispersed phase particles consisting of 84 g of spherical sulfonated polymer (
Hereinafter, these will be referred to as dispersed phase particles (3). ).

The average particle diameter of the obtained dispersed phase particles (3) was measured using a particle size distribution analyzer and was found to be 66 μm. When the ion exchange capacity of the dispersed phase particles (3) was determined by neutralization titration and elemental analysis, it was found to be 5.3
equivalent/g, which was 5.3 equivalent/g by elemental analysis.

The water content in the dispersed phase particles (3) was measured using a Karl Fischer moisture meter and was found to be 2.8 parts by weight.

30 g of the obtained dispersed phase particles <3) were added to 70 g of bromobenzene.
The electrorheological fluid composition of the present invention (
Hereinafter, this will be referred to as fluid composition (3). ) was obtained.

Example 4 1.2j water in a 3j four separable flask equipped with a stirrer, reflux condenser and thermometer! After adding and dissolving 16.0 g of Kuraray Bobal PVA-205 (polyvinyl alcohol manufactured by Kuraray), 140 g of styrene, 130 g of methoxystyrene, 30 g of the same industrial divinylbenzene used in Example 1, and A mixture consisting of 5 g of azobisisobutyronitrile was added. Thereafter, the contents in the flask were dispersed using a disperser (rotation speed: 5000 rpm) and polymerized at 80° C. for 12 hours. The obtained solid was separated, thoroughly washed with water, and then dried at 80°C for 12 hours using a hot air dryer to form a spherical crosslinked polymer (hereinafter referred to as a crosslinked polymer (3)).1291
I got g.

50 g of the polymer crosslinked product (3) and 200 g of dichloroethane were placed in 21 four-piece removable flasks equipped with a stirrer, a thermometer, and a dropping funnel, and the mixture was cooled to 0° C. using a water bath while stirring. Next, 400 g of chlorosulfuric acid was added from the dropping funnel over 2 hours to form a uniform dispersion. Next, the reaction mixture was removed from the water bath and stirred at room temperature (20°C) for 6 hours, and then the temperature of the reaction mixture was further raised to 80°C and heated and stirred at the same temperature for 7 hours to perform a sulfonation reaction.

After that, the reaction mixture was poured into water at 0°C, and after being separated,
Washed with water and acetone.

The obtained solid was dissolved in a 10% by weight aqueous sodium hydroxide solution 2
After neutralizing with 50ml and thoroughly washing with water,
Dry at 80℃ for 10 hours using a vacuum dryer, weighing 109g.
Dispersed phase particles (hereinafter referred to as
These are called dispersed phase particles (4). ) was obtained.

The average particle diameter of the obtained dispersed phase particles (4) was measured using a particle size distribution analyzer and found to be 12 μm. When the ion exchange capacity of the dispersed phase particles (4) was determined by neutralization titration and elemental analysis, it was found to be 5.51 by neutralization titration.
It was found to be 1 Ir equivalent/lr, and 5.6 Ir equivalent/l by elemental analysis. The water content in the dispersed phase particles (4) was measured using a Karl Fischer moisture meter and was found to be 2.6 parts by weight.

The obtained dispersed phase particles (4) 30+r were mixed and dispersed in 70 g of 12.4 tetrachlorobenzene to obtain an electrorheological fluid composition of the present invention (hereinafter referred to as fluid composition (4)). .

Example 5 50 g of the polymerized crosslinked product (3) obtained in Example 4 was charged into a 2Jl four-separable flask equipped with a stirrer, a thermometer, and a dropping funnel, and heated to 0°C using a water bath while stirring.
It was cooled to Next, 500 g of chlorosulfuric acid was added from the dropping funnel over 2 hours to obtain a uniform dispersion.4 Next, the mixture was removed from the water bath, stirred at room temperature (20°C) for 24 hours, and the temperature of the reaction mixture was further increased to 90°C. The mixture was heated and stirred at the same temperature for 45 minutes to carry out a sulfonation reaction.

After that, the reaction mixture was poured into water at 0 °C, and after being distributed from house to house,
Washed with water and acetone.

The obtained solid was dissolved in a 10% by weight aqueous sodium hydroxide solution 2
After neutralizing with 60 ml and thoroughly washing with water,
Dry at 80℃ for 10 hours using a vacuum dryer, weighing 108g
Dispersed phase particles (hereinafter referred to as
This gave dispersed phase particles (referred to as 5).

When the average particle diameter of the obtained dispersed phase particles (5) was measured using a particle size distribution analyzer, it was 12 μm.The ion exchange capacity of the dispersed phase particles (5) was determined by neutralization titration method and elemental analysis method. When quantitatively determined, it was 5.6■ by neutralization titration method.
equivalent/g, which was 5.6 equivalent/g by elemental analysis.

The water content in the dispersed phase particles (5) was measured using a Karl Fischer moisture meter and was found to be 2.51 t parts.

30g of the obtained dispersed phase particles (5) was
(A mixture of biphenyl and diphenyl ether manufactured by Nippon Steel Chemical ■) was mixed and dispersed in 70 g to form the electrorheological fluid composition of the present invention (hereinafter referred to as fluid composition (5)).
I got it.

Example 6 In a 300011 four-necked flask equipped with a stirrer, reflux condenser, thermometer and addition funnel, 50 ml of water, 0.4 g of sodium lauryl sulfonate and 1.5 g of dodecane are added. O
After adding g, the mixture was emulsified using a disperser.

Furthermore, after adding 50 ml of water, 0.2 t of sodium persulfate, 30 g of styrene, 15+r of methylstyrene, and 15 g of the same industrial divinylbenzene used in Example 1, the mixture was polymerized by heating at 50° C. for 8 hours with stirring. , 160 ml of an emulsion of seed particles was obtained.

Next, 1°2 J of water was charged into a 3J fourth flask equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel.
After adding 160 ml of the seed particle emulsion prepared previously and 2.8 g of sodium lauryl sulfonate, they were uniformly dispersed while stirring. Then, increase the rotation speed of the stirrer to 250 rpm.
A mixture consisting of 120 g of styrene, 60 g of methylstyrene and 60 g of the same technical grade divinylbenzene as used in Example 1 was then heated to 70° C. while maintaining the temperature at m and 2 g of sodium persulfate dissolved in 10 ml of water was added. was added dropwise over 18 hours. Furthermore, after reacting at the same temperature for 5 hours, the temperature was raised to 90°C and the reaction was completed after 3 hours. The solid content of the obtained dispersion was separated from each other and dried at 80° C. for 12 hours using a hot air dryer to obtain 7267 g of a spherical crosslinked polymer (hereinafter referred to as crosslinked polymer (4)).

50 t of polymerized crosslinked product (4), 170 g of 98% by weight concentrated sulfuric acid, and 200 g of dichloroethane were placed in a 2J four-piece rose valve flask equipped with a stirrer, a thermometer, and a dropping funnel, and the mixture was heated to 0°C using a water bath while stirring. After cooling, 330 f of chlorosulfuric acid was added from the dropping funnel over 2 hours to form a uniform dispersion. Next, the reaction mixture was removed from the water bath and stirred at room temperature (20°C) for 24 hours, and then the temperature of the reaction mixture was further raised to 90°C and heated and stirred at the same temperature for 1 hour to perform a sulfonation reaction. Then the reaction mixture was reduced to 0
Pour into water at ℃ and wash with water and acetone after going door to door.

The obtained solid was dissolved in a 10% by weight aqueous sodium hydroxide solution 2
After neutralizing with 00 ml, wash thoroughly with water. Next, it was dried at 80°C for 10 hours using a vacuum dryer, and 93g
Dispersed phase particles (hereinafter referred to as
These are called dispersed phase particles (6). ) was obtained.

The average particle diameter of the obtained dispersed phase particles (6) was measured using a particle size distribution analyzer and found to be 5 μm.The ion exchange capacity of the dispersed phase particles (6) was determined by neutralization titration and elemental analysis. The water content in the dispersed phase particles (6) was determined to be 5.0 eq/l by neutralization titration and 4.9 eq/l by elemental analysis using a Karl Fischer moisture meter. When measured, it was 2.7 parts by weight.

30 g of the obtained dispersed phase particles (6) were mixed with Shin-Etsu silicone oil K F 96 100 CS (C5t4 + Chemical I
The electrorheological fluid composition of the present invention (hereinafter referred to as fluid composition (6)) was obtained.

Example 7 A 3J four-piece removable flask equipped with a stirrer, a reflux condenser, and a thermometer was charged with 1.2J of water, and 1.2J of water was added to it. After dissolving, further add 130 g of styrene, 60 g of methoxystyrene, 3 g of chlorostyrene.
A mixture consisting of 0 g, 80 g of the same technical grade divinylbenzene used in Example 1 and 5 g of azobisisobutyronitrile was added. After that, disperser (number of revolutions: 10,000
Disperse the contents in the flask using
Polymerization was carried out at ℃ for 14 hours. The obtained solid was separated, thoroughly washed with water, and then dried at 80°C for 12 hours using a hot air dryer to form a spherical crosslinked polymer (hereinafter referred to as a crosslinked polymer).
), 287 g was obtained.

50 g of the polymer crosslinked product (5) and 250 t of nitrobenzene were charged into a 2J four-piece separable flask equipped with a stirrer, a thermometer, and a dropping funnel, and the mixture was cooled to 0°C using a water bath while stirring. 500 g of acid was added from the dropping funnel over 2 hours to form a uniform dispersion. It was then removed from the water bath and incubated at room temperature (20°C) for 24 hours.
After stirring for an hour, the temperature of the reaction mixture was further raised to 100° C. and heated and stirred at the same temperature for 2 hours to perform a sulfonation reaction. Thereafter, the reaction mixture was poured into water at 0°C, separated, and washed with water and acetone.

The resulting solid was neutralized with pyridine 4'zr, thoroughly washed with water, and then dried in a vacuum dryer at 80°C for 10 hours to form a dispersion consisting of 128 g of spherical sulfonated polymer. Phase particles (hereinafter referred to as dispersed phase particles (7)) were obtained.

The average particle diameter of the obtained dispersed phase particles (7) was measured using a particle size distribution analyzer and was found to be 6 μm. When the ion exchange capacity of the dispersed phase particles (7) was determined by neutralization titration and elemental analysis, it was 3.9 equivalents/g by neutralization titration and 4.0 equivalents/g by elemental analysis. The water content in the dispersed phase particles (7) was measured using a Karl Fischer moisture meter and found to be 2.6 parts by weight.

30g of the obtained dispersed phase particles (7) was
(Partially hydrogenated triphenyl manufactured by Nippon Steel Chemical) 70
The electrorheological fluid composition of the present invention (
Hereinafter, this will be referred to as fluid composition (7). ) was obtained.

Comparative Example 1 50 g of the polymerized crosslinked product (I) obtained in Example 1 and 200 g of tetrachloroethane were charged into a 2JL four-separable flask equipped with a stirrer, a thermometer, and a dropping funnel, and a water bath was used while stirring. and cooled to 0°C. Next, 98% by weight concentrated fa #! 350 g of i was added from the dropping funnel over 2 hours to make a uniform dispersion.9 Then,
After removing from the water bath and stirring at room temperature (20°C) for 24 hours, the temperature of the reaction mixture was further raised to 80°C and
The mixture was heated and stirred for hours to carry out a sulfonation reaction. after that,
Pour the reaction mixture into 0°C water, separate and wash with water and acetone.

The obtained solid was dissolved in a 10% by weight aqueous sodium hydroxide solution.
After neutralizing with 0ml, the solution was thoroughly washed with water.

Next, it was dried at 80°C for 10 hours using a vacuum dryer,
Comparative dispersed phase particles made of a 63f spherical sulfonated polymer (hereinafter referred to as comparative dispersed phase particles (I))
I got it.

The average particle diameter of the obtained comparative dispersed phase particles <1) was measured using a particle size distribution analyzer and was found to be 50 μm.

When the ion exchange capacity of the comparative dispersed phase particles (I) was determined by neutralization titration and elemental analysis, it was 2.7 equivalents/g by neutralization titration and 2.7 equivalents/g by elemental analysis. there were. The water content in the comparative dispersed phase particles (I) was measured using a Karl Fischer moisture meter and was found to be 2.7 parts by weight.

30 g of the obtained comparative dispersed phase particles (I) were mixed and dispersed in 70 g of Shin-Etsu silicone oil ■KF96-20C3 (dimethyl silicone oil manufactured by Shin-Etsu Chemical I-Gyo ■), and a comparative electrorheological flow composition (hereinafter referred to as , which was referred to as comparative fluid composition (I)) was obtained.

Comparative Example 2 The polymerized crosslinked product obtained in Example 1 was placed in a 2J four-day separable flask equipped with a stirrer, a thermometer, and a dropping funnel.
1) 50 g and 200 g of tetrachloroethane were charged, and the mixture was cooled to 0° C. using a water bath while stirring. Then,
350 g of 98% by weight concentrated sulfuric acid was added from the dropping funnel over 2 hours to form a uniform dispersion. Next, the reaction mixture was removed from the water bath and stirred at room temperature (20°C) for 24 hours, and then the temperature of the reaction mixture was raised to 80°C and heated at the same temperature for 24 hours.
The mixture was stirred to perform a sulfonation reaction. Thereafter, the reaction mixture was poured into water at 0° C., P was removed, and then washed with water and acetone.

The obtained solid was dissolved in a 10% by weight aqueous sodium hydroxide solution.
After neutralizing with 70 all, thoroughly washed with water, it was then dried at 80°C for 10 hours using a vacuum dryer, and 87
Comparative dispersed phase particles 1 or less consisting of a spherical sulfonated polymer of g, which will be referred to as comparative dispersed phase particles (2), were obtained.

The average particle diameter of the comparative dispersed phase particles (2) obtained was measured using a particle size distribution analyzer and was found to be 50 μm.

When the ion exchange capacity of the comparative dispersed phase particles (2) was determined by neutralization titration and elemental analysis, it was 4.6 equivalents/g by neutralization titration and 4.5 equivalents/g by elemental analysis. there were. The water content in the comparative dispersed phase particles (2) was measured using a Karl Fischer moisture meter and was found to be 2.8 parts by weight.

30 g of the obtained comparative dispersed phase particles (2) were mixed and dispersed in 70 g of Shin-Etsu silicone oil KF96-20C3 (dimethyl silicone oil manufactured by Shin-Etsu Chemical Co., Ltd.), and a comparative electrorheological fluid composition (hereinafter referred to as this) was mixed and dispersed. A comparative fluid composition (2) was obtained.

Comparative Example 3 50 g of polymeric crosslinked product (I) and 350 g of tetrachloroethane were charged into a 2J four-piece separable flask equipped with a stirrer, a thermometer, and a dropping funnel, and cooled to 0° C. using a water bath while stirring.

Next, 240 g of chlorosulfuric acid was added from the dropping funnel over 2 hours to form a uniform dispersion. Next, the reaction mixture was removed from the water bath and stirred at room temperature (20°C) for 24 hours, and then the temperature of the reaction mixture was raised to 80°C and heated at the same temperature for 2 hours.
The mixture was stirred to perform a sulfonation reaction. Thereafter, the reaction mixture was poured into water at 0°C, separated, and washed with water and acetone.

The obtained solid was dissolved in a 10% by weight aqueous sodium hydroxide solution.
After neutralizing with 70 ml and thoroughly washing with water,
Comparative dispersed phase particles consisting of 88 g of spherical sulfonated polymer were dried at 80° C. for 10 hours using a vacuum dryer.
Hereinafter, these were referred to as comparative dispersed phase particles (3)).

The average particle diameter of the comparative dispersed phase particles (3) obtained was measured using a particle size distribution analyzer and was found to be 50 μm.

When the ion exchange capacity of the comparative dispersed phase particles (3) was determined by neutralization titration and elemental analysis, it was 4.6 equivalent/g by neutralization titration and 4.6 equivalent/g by elemental analysis. Met. The water content in the comparative dispersed phase particles (3) was measured using a Karl Fischer moisture meter and was found to be 2.6 parts by weight.

30 g of the comparative dispersed phase particles (3) obtained were mixed and dispersed in 70 g of Shin-Etsu silicone oil KF96-20C3 (dimethyl silicone oil manufactured by Shin-Etsu Chemical Co., Ltd.), and a comparative electrorheological fluid composition (hereinafter referred to as this) was mixed and dispersed. A comparative fluid composition (referred to as (3)) was obtained.

Example 8 Each of the fluid compositions (I) to (7) and comparative fluid compositions (I) to (3) obtained in Examples 1 to 7 and Comparative Examples 1 to 3 was placed in a double cylinder with a coaxial electric field. Place in a rotational viscometer, inner/outer cylinder gap 1.0, shear rate 400S, temperature 25℃.
AC external electric field 4000V/m (frequency: 60
The shear road force value (initial value) when a voltage (Hz) was applied and the current density (initial value) flowing at that time were measured.

In addition, the shear road force value (value after 7 days) and current density (value after 7 days) after continuous operation of the viscometer at 25°C for 7 days with an external electric field of 4000 V/Iff+ applied. The stability of the fluid composition over time was investigated.

The results are shown in Table 1. Note that the fluid composition (I
- Average particles of dispersed phase particles (I) to (7) and comparative dispersed phase particles (I) to (3) contained in each of ) to (7) and comparative fluid compositions (I) to <3) Also show the diameter in Table 1.

The more excellent the electrorheological fluid is in shear path force characteristics, such as a large shear path force value obtained when a relatively weak electric field is applied, and the better the current characteristics, in which the current density flowing at that time is small, the better. It is particularly preferable to have excellent shear path force characteristics and current characteristics. Therefore, a constant electric field was applied as a parameter for simultaneously evaluating the shear path force characteristics and current characteristics to judge the superiority of the electrorheological fluid composition. The ratio of the shear road force value obtained at that time to the current density flowing at that time, that is, (shear road force value)/(current density) (hereinafter, this value is referred to as a binary value) is effective. In other words, an electrorheological fluid composition that is excellent in both shear path force characteristics and current characteristics has a large Z value.

Fluid compositions (I) to (7) and comparative fluid composition (I)
The initial value and the value after 7 days of the Z value of each fluid composition determined from the shear path force value and current density observed when an electric field of 4000 V/m+ was applied to each of (3)
Shown in the table.

As is clear from Table 1, the fluid compositions (I) to (7) obtained in the present invention have shear path force characteristics in that they generate a large shear path force even when a relatively weak electric field is applied. It had excellent current characteristics in that the current density flowing at that time was small, and it was very excellent in shear path force that did not occur and the stability of the current density over time. In addition, the fluid compositions (I) to (7) obtained in the present invention have a Z value of 1°5 or more at the initial stage, and are electrorheological fluid compositions with well-balanced shear path force characteristics and current characteristics. I found out something. Furthermore, the fluid compositions (I) to (7) obtained in the present invention have a Z value of 1.5 or more even after 7 days, and have excellent stability over time in the balance between shear road force characteristics and current characteristics. It turned out to be an electrorheological fluid composition.

On the other hand, in the comparative fluid composition (I), a large shear path force cannot be obtained by applying a relatively weak electric field, the current density flowing at that time is greater than that of the fluid composition of the present invention, and no shear path is generated. The stability of the force and current density over time was poor, and it became impossible to measure them after 3 days. Also, comparative fluid composition (I)
The Z value was 0.6 even at the initial stage, and the balance between shear path force characteristics and current characteristics was worse than that of the fluid composition of the present invention.

Comparative fluid composition (2) and comparative fluid composition (3) are fluid compositions of the present invention obtained by sulfonation of the same polymeric crosslinked product (I) and composed of dispersed phase particles having the same average particle diameter. Compared to material (I) and fluid composition (2), the obtained shear path force is small, the current density is large, and the stability of the generated shear path force and current density is poor over time.
It became impossible to measure after a few days. In addition, comparative fluid composition (2
) and comparative fluid composition (3) both had a Z value of 0.7 even at the initial stage, and the balance between shear path force characteristics and current characteristics was worse than that of the fluid composition of the present invention.

Claims (1)

[Scope of Claims] 1. A composition comprising dispersed phase particles made of a sulfonated polymer having an aromatic ring substituted with a sulfonic acid group in an insulating dispersion medium, the composition comprising: However, a polymerized crosslinked product (I) of a monomer mixture (A) containing a vinyl aromatic compound (a) and a polyvinyl compound (b) as main components, and other vinyl compounds (c) added as necessary, is used as a polymerized crosslinked product (I). I) An electrorheological fluid composition obtained by sulfonation with 500 parts by weight or more of chlorosulfuric acid per 100 parts by weight. 2. The electrorheological fluid composition according to claim 1, wherein the sulfonation is carried out by maintaining the crosslinked polymer (I) at a temperature of 70° C. or higher for 30 minutes or more in the presence of chlorosulfuric acid. 3. Sulfonation is performed by sulfonating the polymerized crosslinked product (I) in the presence of chlorosulfuric acid in a temperature range of -20°C or higher and lower than 70°C.
The electrorheological fluid composition according to claim 1, wherein the electrorheological fluid composition is further held at a temperature of 70°C or higher for 30 minutes or more after being held for 30 hours. 4. The constituent components of the monomer mixture (A) are 5000 to 99
．． 9 mol% vinyl aromatic compound (a) and 0.1-50
．． The electrorheological fluid composition according to any one of claims 1 to 3, comprising 0 mol % of the polyvinyl compound (b). 5. The electrorheological fluid composition according to any one of claims 1 to 4, wherein the dispersed phase particles contain 10 parts by weight or less of water based on 100 parts by weight of the sulfonated polymer. 6. The electrorheological fluid composition according to any one of claims 1 to 5, wherein the average particle diameter of the dispersed phase particles is in the range of 0.1 to 100 μm. 7. The electrorheological fluid composition according to any one of claims 1 to 6, wherein the ratio of the dispersed phase particles to the insulating dispersion medium is in the range of 50 to 500 parts by weight to 100 parts by weight of the former.