JP2875911B2 - Electrorheological fluid composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to an electrorheological fluid composition. More specifically, an electrorheological fluid composition that generates a large shear stress even by applying a relatively weak electric field, has a small current density flowing at that time, and has excellent stability over time of the generated shear stress and current density. It is about.

[0002]

2. Description of the Related Art An electrorheological fluid is a fluid obtained by dispersing and suspending solid particles in an insulating dispersion medium, for example.
A fluid whose rheological or flow properties change to viscoplastic properties by applying an electric field change.In general, the viscosity increases significantly when an external electric field is applied, and the so-called Winslow effect, which induces a large shear stress. Fluid known as Since the Winslow effect has the characteristic of quick response, the electrorheological fluid is applied to actuators for torque transmission such as clutches and brakes, actuators for controlling engine mounts, dampers, valves, etc., and electrorheological fluid inkjet. Attempted.

[0003] Conventionally, as an electrorheological fluid composition, cellulose, starch, soybean casein, silica gel, polystyrene ion exchange resin, crosslinked polyacrylate, etc. in insulating oils such as silicone oil, diphenyl chloride, and trans oil. Are known in which solid particles are dispersed.

However, an electrorheological fluid composition using cellulose, starch or soybean casein as a disperse phase has a problem that the shear stress obtained when an electric field is applied is small. The electrorheological fluid composition used as the above has a problem in that a shearing stress sufficient for practical use is not induced only by applying a relatively weak electric field.

An electrorheological fluid composition using an alkali metal salt type ion exchange resin of polystyrene sulfonic acid, which is one of polystyrene ion exchange resins, as a dispersed phase has a large shear stress even when a relatively weak electric field is applied. However, there was a problem that the current density flowing at that time was large, and the generated shear stress and the current density were poor in stability over time.

On the other hand, as a result of studying an electrorheological fluid composition using a sulfonated polymer particle obtained by sulfonating a polymerized crosslinked product mainly composed of styrene and divinylbenzene with sulfuric acid as a dispersion phase, The composition can also obtain a large shear stress by applying a relatively weak electric field, but has a problem that the current density flowing at that time is large and the generated shear stress and current density are poor in stability over time.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of conventional electrorheological fluid compositions. Therefore, an object of the present invention is to provide an electrorheological fluid in which a large shear stress is generated even when a relatively weak electric field is applied, the current density flowing at that time is small, and the generated shear stress and the current density have excellent stability over time. It is to provide a composition.

[0008]

SUMMARY OF THE INVENTION The present invention provides a composition obtained by dispersing dispersed phase particles comprising a sulfonated polymer having an aromatic ring substituted with a sulfonic acid group in an insulating dispersion medium. In addition, the sulfonated polymer is a polymer crosslinked product of a monomer mixture (A) containing a vinyl aromatic compound (a) and a polyvinyl compound (b) as main components and optionally adding another vinyl compound (c) ( The present invention relates to an electrorheological fluid composition obtained by sulfonating I) in the presence of a sulfonating agent and a + 5-valent phosphorus compound.

The sulfonic acid group referred to in the present invention is a cation released in the presence of a polar solvent such as water by releasing a cation in the presence of a polar solvent such as water. There is no particular limitation.

[0010] The sulfonated polymer constituting the dispersed phase particles used in the present invention contains a vinyl aromatic compound (a) and a polyvinyl compound (b) as main components, and may further contain another vinyl compound (c) if necessary. It is obtained by sulfonating the polymerized crosslinked product (I) of the monomer mixture (A), but it is necessary to sulfonate using a sulfonating agent in the presence of a + 5-valent phosphorus compound. Conventionally used electrorheological fluid compositions using sulfonated polymer particles as dispersed phase particles, obtained by using sulfuric acid alone as a sulfonating agent, generate large shear stress by applying a relatively weak electric field. However, there is a problem that the current density flowing at that time is large, and the generated shear stress and the current density have poor stability over time. However, even when sulfuric acid is used as the sulfonating agent, when sulfonated in the presence of a + 5-valent phosphorus compound, the sulfonated polymer suitable for the dispersed phase particles which provides the above-described electrorheological fluid composition excellent in various performances Is obtained. When chlorosulfuric acid or fuming sulfuric acid having high activity is used as a sulfonating agent in combination with a + 5-valent phosphorus compound, a sulfonated polymer suitable for the electrorheological fluid composition of the present invention can be used without using a large amount of the sulfonating agent. Coalescence is easily obtained.

The amount of the + pentavalent phosphorus compound used in the present invention is preferably 1.0 part by weight or more, more preferably 10 to 500 parts by weight, based on 100 parts by weight of the polymer crosslinked product (I). If less than 1.0 part by weight,
The effect of adding a pentavalent phosphorus compound may not be observed.

The + pentavalent phosphorus compound that can be used in the present invention includes, for example, phosphorus pentoxide, phosphorus oxychloride,
Examples thereof include phosphorus pentachloride, and one or more of these can be used.

Examples of the sulfonating agent that can be used in the present invention include conventionally known sulfonating agents such as sulfuric acid, chlorosulfuric acid, fuming sulfuric acid, and sulfur trioxide. Can be used. Among them, it is preferable to use sulfuric acid from the viewpoint of easy handling.

When sulfuric acid is used as the main component of the sulfonating agent, it is preferable to use 500 parts by weight or more of sulfuric acid with respect to 100 parts by weight of the polymer crosslinked product (I).

When chlorosulfuric acid is used as the main component of the sulfonating agent, chlorosulfuric acid is used as the polymerized crosslinked product (I) 10
It is preferable to use 400 parts by weight or more with respect to 0 parts by weight.

When fuming sulfuric acid is used as the main component of the sulfonating agent, it is preferable to use fuming sulfuric acid in an amount of 120 parts by weight or more based on 100 parts by weight of the crosslinked polymer (I).

The monomer mixture (A) that can be used in the present invention has a vinyl aromatic compound (a) of 50.0 to
99.9 mol%, polyvinyl compound (b) is 0.1 to 5
The proportion is preferably in the range of 0.0 mol%. The constituent ratio of the vinyl aromatic compound (a) is less than 50.0 mol%, or the constituent ratio of the polyvinyl compound (b) is 50.
If the amount exceeds 0 mol%, the sulfonation reaction hardly proceeds, and a large shear stress cannot be obtained when an electric field is applied to an electrorheological fluid composition using the obtained sulfonated polymer particles. May occur. Also,
Constituent ratio of vinyl aromatic compound (a) is 99.9 mol%
Or the composition ratio of the polyvinyl compound (b) exceeds 0.1.
When the amount is less than 10%, there may be a problem that particles adhere to each other when the crosslinked polymer obtained by polymerization is sulfonated.

The vinyl aromatic compound (a) which can be used in the present invention includes, for example, vinyl aromatic hydrocarbons such as styrene, vinyl naphthalene, vinyl anthracene and vinyl phenanthrene; methyl styrene, ethyl styrene, propyl styrene and butyl Monoalkylstyrene compounds such as styrene, pentylstyrene and hexylstyrene; dimethylstyrene, diethylstyrene, dipropylstyrene, methylethylstyrene, methylpropylstyrene, methylhexylstyrene, ethylbutylstyrene, ethylpropylstyrene, ethylhexylstyrene, propylbutylstyrene Dialkylstyrene compounds such as; trimethylstyrene, triethylstyrene,
Tripropylstyrene, methyldiethylstyrene, dimethylethylstyrene, methylethylpropylstyrene,
Trialkylstyrene compounds such as methyldipropylstyrene, dimethylpropylstyrene, ethyldipropylstyrene and diethylpropylstyrene; vinylmonoalkylnaphthalene compounds such as vinylmethylnaphthalene, vinylethylnaphthalene and vinylpropylnaphthalene; vinyldimethylnaphthalene and vinyldiethylnaphthalene , Vinyldialkylnaphthalene compounds such as vinyldipropylnaphthalene and vinylmethylethylnaphthalene; vinyltrialkyl such as vinyltrimethylnaphthalene, vinyltriethylnaphthalene, vinyltripropylnaphthalene, vinylmethyldiethylnaphthalene, vinyldimethylethylnaphthalene and vinylmethylethylpropylnaphthalene Naphthalene compound; chlorostyrene, bromostyrene, fluoro Styrene, chloromethyl styrene, chloro ethylstyrene, chloropropyl styrene,
Halogenated vinyl aromatic compounds such as chlorodimethylstyrene, bromomethylstyrene, bromoethylstyrene, fluoromethylstyrene, fluoroethylstyrene, vinylchloronaphthalene, vinylbromonaphthalene; methoxystyrene, dimethoxystyrene, trimethoxystyrene, ethoxystyrene, Ethoxystyrene, triethoxystyrene, propyloxystyrene, dipropyloxystyrene, phenoxystyrene, methoxymethylstyrene, methoxyethylstyrene, methoxypropylstyrene, ethoxymethylstyrene, ethoxyethylstyrene, propyloxymethylstyrene, propyloxyethylstyrene, methoxy Dimethylstyrene, methoxydiethylstyrene, phenoxydimethylstyrene,
Phenoxydiethylstyrene, methoxychlorostyrene, methoxybromostyrene, vinylmethoxynaphthalene, vinyldimethoxynaphthalene, vinylethoxynaphthalene, vinyldiethoxynaphthalene, vinylmethoxymethylnaphthalene, vinylmethoxydimethylnaphthalene, vinyldimethoxymethylnaphthalene, vinylmethoxychloronaphthalene, vinyl Examples thereof include alkoxylated or aryloxylated vinyl aromatic compounds such as dimethoxychloronaphthalene, and one or more of these can be used.

Examples of the polyvinyl compound (b) that can be used in the present invention include divinylbenzene, divinyltoluene, divinylxylene, divinylethylbenzene, divinyldiethylbenzene, divinylpropylbenzene, divinylnaphthalene, trivinylbenzene, trivinyltoluene, Polyvinyl aromatic hydrocarbons such as trivinyl xylene and trivinyl naphthalene; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, N, N-methylenebisacrylamide, diallyl maleate And polyvinyl aliphatic compounds such as diallyl adipate, and one or more of these can be used.

The monomer mixture (A) in the present invention may contain, if necessary, a vinyl compound (c) other than the vinyl aromatic compound (a) or the polyvinyl compound (b). Desirably, it is at most mol%. 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, ethyl (meth) acrylate Ester compounds of unsaturated carboxylic acids such as vinyl acetate; vinyl ester compounds of monovalent carboxylic acids such as vinyl acetate and vinyl propionate; unsaturated amide compounds such as (meth) acrylamide, diacetone acrylamide, and methylolated (meth) acrylamide; Derivatives thereof; unsaturated cyanide compounds such as (meth) acrylonitrile and crotonnitrile; unsaturated alcohol compounds such as (meth) allyl alcohol and croton alcohol; unsaturated monobasic acids such as (meth) acrylic acid; and maleic acid Unsaturated dibasic acids such as fumaric acid and itaconic acid; monoester compounds of monohydric alcohols such as monomethyl maleate and monoallyl maleate with unsaturated dibasic acids; Can be used alone or in combination of two or more.

The shape of the dispersed phase particles used in the present invention is preferably spherical or elliptical spherical. When the shape of the dispersed phase particles is a shape other than spherical or elliptical spherical,
When an electric field is applied to the prepared electrorheological fluid composition, a problem that a large shear stress cannot be obtained or a problem that the temporal stability in a state where the electric field is continuously applied becomes poor may occur.

The average particle size of the dispersed phase particles used in the present invention is preferably in the range of 0.1 to 100 μm.
In the electrorheological fluid composition of the present invention, the shear stress obtained when an electric field is applied to the prepared electrorheological fluid composition tends to decrease as the particle size of the dispersed phase decreases, When the average particle diameter is less than 0.1 μm, a problem may occur that a large shear stress cannot be obtained when an electric field is applied to the prepared electrorheological fluid composition. Further, the average particle size of the dispersed phase particles is 1
If it exceeds 00 μm, the shear stress value obtained when a certain electric field is applied to the prepared electrorheological fluid composition may be irregular, which may cause a problem that stability is difficult.

In the present invention, the method for producing the polymerized crosslinked product (I) used as an intermediate for obtaining the sulfonated polymer is not particularly limited, and may be a known polymerization method such as a suspension polymerization method, an emulsion polymerization method, or the like. Examples of the method include a dispersion polymerization method, a solution polymerization method, and a bulk polymerization method. Among them, a suspension polymerization method and an emulsion polymerization method are preferable as a method for easily obtaining a spherical or oval spherical polymer crosslinked product (I).

When a suspension polymerization method is used as the polymerization method for producing the polymer crosslinked product (I) used in the present invention, the conditions for the polymerization are not particularly limited.

As a dispersion medium for suspension polymerization, water or the like is usually used.

Examples of the dispersant for suspension polymerization include polyvinyl alcohol, carboxymethyl cellulose, ammonium salts of styrene-maleic anhydride copolymer, bentonite, sodium poly (meth) acrylate, poly (diallylmethylammonium chloride) and the like. Known ones can be used.

Examples of the polymerization initiator for suspension polymerization include benzoyl peroxide, tertiary butyl hydroxy peroxide, cumene peroxide, lauroyl peroxide, methyl ethyl ketone peroxide, tertiary butyl perphthalate, caproyl peroxide. Peroxides such as azobisisobutyronitrile, azobisisobutylamide, 2,2′-azobis (2,4-dimethylmaleronitrile), azobis (α
-Dimethylvaleronitrile), azo compounds such as azobis (α-methylbutyronitrile) and the like, and one or more of these can be used.

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

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

In the suspension polymerization, for example, water and a dispersant are charged, a mixture of monomers in which a polymerization initiator is dissolved is added thereto, and the particle size is regulated using a disperser or a stirrer. The reaction is carried out at a predetermined temperature in a suspended state.

When an emulsion polymerization method is used for producing the polymer crosslinked product (I) used in the present invention, the conditions for polymerization are not particularly limited.

As the solvent for the emulsion polymerization, water or the like is usually used.

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

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

The 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 a seed polymerization method, a batch charging polymerization method, a monomer addition polymerization method and an emulsion addition polymerization method can be used.

In order to carry out the seed polymerization method, usually, first, seed particles, water, an emulsifier and the like are charged into a reaction vessel, and the mixture is uniformly dispersed under stirring, and then a part or all of the monomer mixture is optionally added. Added. Next, after heating to a predetermined temperature, a polymerization initiator is added to start the reaction. Further, the rest of the monomer mixture is added continuously or intermittently,
The emulsification is performed at a predetermined temperature.

The crosslinked polymer (I) used in the present invention comprises:
A substantially non-porous polymer cross-linked product called a gel type may be used, or a known porous forming agent that imparts porosity to the polymer cross-linked product obtained during polymerization, for example, a swellable organic solvent,
It may be a porous polymer crosslinked product obtained by polymerizing a monomer mixture in the presence of a non-swellable organic solvent, a linear polymer soluble in a monomer, or a mixture thereof.

The particles of the sulfonated polymer constituting the dispersed phase particles used in the present invention are obtained by sulfonating the crosslinked polymer (I) obtained by the above-mentioned polymerization method in the presence of the above-mentioned + pentavalent phosphorus compound. It is obtained by pulverizing or granulating to an appropriate particle size as required. When the polymer crosslinked product (I) used is a particulate product obtained by a suspension polymerization method or an emulsion polymerization method, the sulfonated polymer particles suitable as the dispersed phase particles in the present invention can be easily formed by sulfonation. Obtainable.

The sulfonation reaction is carried out without a solvent, in the presence of a solvent that does not swell with respect to the polymerized crosslinked product (I), or in the presence of a solvent that is swellable with respect to the polymerized crosslinked product (I). Can be.

The solvent which does not swell with respect to the crosslinked polymer (I) may be any solvent which does not swell the crosslinked polymer (I) and is inert to the sulfonating agent. Examples thereof include aliphatic hydrocarbons such as cyclohexane and ligroin.

The solvent capable of swelling with respect to the crosslinked polymer (I) may be any solvent which swells the crosslinked polymer (I) and is inert to the sulfonating agent, such as ethylene dichloride and trichloroethylene. , Tetrachloroethane, nitrobenzene, propylene chloride, carbon tetrachloride and the like.

The use amount of these solvents is preferably within a range of 1000 parts by weight or less based on 100 parts by weight of the polymer crosslinked product (I).

The conditions for the sulfonation reaction may be appropriately determined according to the type and amount of the sulfonating agent and the + 5-valent phosphorus compound to be used. For example, the sulfonation reaction is carried out at a temperature within the range of -20 to 250 ° C. Sulfonation is performed by holding for about 3 to 100 hours. Preferable reaction conditions for sulfonation include a method in which the crosslinked polymer (I) is maintained at a temperature of 60 ° C. or higher for 30 minutes or more in the presence of a sulfonating agent and a + 5-valent phosphorus compound, or 20 ° C or higher 60
After holding for 0.3 to 30 hours in a temperature range of less than ° C, a method of holding for 30 minutes or more at a temperature of 60 ° C or more can also be mentioned. Above all, a method considering the ease of controlling the sulfonation reaction is preferable.

The particles of the sulfonated polymer obtained by sulfonating the polymerized crosslinked product (I) are separated from the sulfonating agent, and then a large amount of water is used to remove the acid and the like remaining in the particles. It is good to wash thoroughly. Then, if necessary, the cation of the sulfonic acid group can be changed from a proton to an appropriate cation species by a method such as neutralization or ion exchange.

The neutralized or ion-exchanged particles of the sulfonated polymer are used as dispersed phase particles by removing unnecessary water. Conditions for removing unnecessary water are as follows: under an inert gas atmosphere or under reduced pressure;
It is preferably performed at 80 ° C. In removing unnecessary water, it is preferable to pre-treat with a hydrophilic organic solvent such as methanol, isopropanol, or acetone before heating in order to easily obtain dispersed phase particles.

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 is, for example, hydrogen; an alkali metal such as lithium, sodium and potassium; , Calcium, etc., alkaline earth metals; aluminum, etc., Group IIIA metals; tin, lead, etc., Group IVA metals; zinc,
Cationic species such as transition metals such as iron, copper, cobalt and nickel, or ammonium, organic quaternary ammonium,
Examples thereof include pyridinium and guadinium, and one or more of these can be used.

The dispersed phase particles used in the present invention are preferably those containing a small amount of water in the aforementioned sulfonated polymer particles. In the electrorheological fluid composition of the present invention, since a small amount of water is contained in the dispersed phase particles, a large shear stress is induced when an electric field is applied. The water in the dispersed phase particles is preferably 20 parts by weight or less based on 100 parts by weight of the sulfonated polymer constituting the particles. When water exceeds 20 parts by weight, the dispersed phase particles adhere to each other, or the prepared electrorheological fluid composition has a reduced insulating property, so that a large current flows when an electric field is applied, which is not preferable. .

The insulating dispersion medium that can be used in the present invention is not particularly limited. For example, silicone oils such as polydimethylsiloxane and polyphenylmethylsiloxane; liquid paraffin, decane, dodecane, methylnaphthalene, dimethylnaphthalene, ethyl Hydrocarbons such as naphthalene, biphenyl, decalin and partially hydrogenated triphenyl; ether compounds such as diphenyl ether;
Chlorobenzene, dichlorobenzene, trichlorobenzene, bromobenzene, dibromobenzene, chloronaphthalene, dichloronaphthalene, bromonaphthalene, chlorobiphenyl, dichlorobiphenyl, trichlorobiphenyl, bromobiphenyl, chlorodiphenylmethane, dichlorodiphenylmethane, trichlorodiphenylmethane,
Halogenated hydrocarbons such as bromodiphenylmethane, chlorodecane, dichlorodecane, trichlorodecane, bromodecane, chlorododecane, dichlorododecane, and bromododecane; halogenated diphenyl ether compounds such as chlorodiphenyl ether, dichlorodiphenyl ether, trichlorodiphenyl ether, and bromodiphenyl ether; Co., Ltd.),
Fluoride such as Demnum (manufactured by Daikin Industries, Ltd.); ester compounds such as dioctyl phthalate, trioctyl trimellitate, and dibutyl sebacate; and the like, and one or more of these can be used. . Among them, silicone oil and hydrocarbon are preferred.

The electrorheological fluid composition of the present invention is obtained by dispersing the above-mentioned dispersed phase particles in an insulating dispersion medium. The ratio of the dispersed phase particles to the insulating dispersion medium in the composition is 10%.
The latter is preferably in the range of 50 to 500 parts by weight with respect to 0 parts by weight. When the amount of the dispersion medium exceeds 500 parts by weight, the shear stress obtained when an electric field is applied to the prepared electrorheological fluid composition may not be sufficiently large. In addition, when the amount of the dispersion medium is less than 50 parts by weight, the fluidity of the prepared composition itself is reduced, and it may be difficult to use the composition as an electrorheological fluid.

In the present invention, for example, a surfactant, a polymer dispersant, or a polymer thickener may be used to improve the dispersibility of the dispersed phase particles in the dispersion medium, adjust the viscosity of the electrorheological fluid composition, or increase the shear stress. Various additives such as agents can be added to the composition.

[0052]

According to the electrorheological fluid composition of the present invention, a large shear stress can be obtained even when a relatively weak external electric field is applied, and the current density at that time is small. It is extremely excellent in stability over time to maintain stable stress and current density over a long period of time, so actuators for transmitting torque such as clutches and brakes, control actuators for engine mounts, dampers, valves, etc., and electrorheological fluid inkjet Etc. can be used effectively.

[0053]

EXAMPLES The present invention will be described below with reference to examples, but the scope of the present invention is not limited only to these examples.

[0054]

Example 1 2.4 liters of water was charged into a 5 liter four-neck separable flask equipped with a stirrer, a reflux condenser and a thermometer, and charged with Kuraray Povar PVA-205 (trade name).
Add 32.0 g of Kuraray's polyvinyl alcohol)
After dissolution, 500 g of styrene and industrial divinylbenzene (a mixture of 55 wt% divinylbenzene, 35 wt% ethylstyrene, etc., manufactured by Wako Pure Chemical Industries, Ltd.) 1
A mixture consisting of 00 g and 8 g of azobisisobutyronitrile was added. Thereafter, the contents in the flask were dispersed at a stirring speed of 600 rpm, and polymerized at 80 ° C. for 8 hours. The obtained solid was separated by filtration, sufficiently washed with water, and then dried at 80 ° C. for 12 hours using a hot air drier to obtain a spherical polymer crosslinked product (hereinafter referred to as polymer crosslinked product (1)). $ 573
g was obtained.

A 2-liter four-neck separable flask equipped with a stirrer, a thermometer and a dropping funnel was charged with 500 g of 98% by weight concentrated sulfuric acid, cooled to 0 ° C. using an ice bath, and stirred with phosphorus pentoxide. 100 g was added over 30 minutes to form a uniform dispersion. Next, the ice bath was removed, 50 g of the crosslinked polymer (1) was charged, the temperature of the reaction mixture was raised to 80 ° C., and the mixture was heated and stirred at the same temperature for 12 hours to carry out a sulfonation reaction. Thereafter, the reaction mixture was poured into water at 0 ° C., filtered, and washed with water / acetone. The obtained solid was neutralized with 270 ml of a 10% by weight aqueous sodium hydroxide solution, and then sufficiently washed with water. Next, it is dried at 80 ° C. for 10 hours using a vacuum dryer, and the dispersed phase particles composed of 110 g of a spherical sulfonated polymer are hereinafter referred to as dispersed phase particles (1). I got｝.

The average particle diameter of the obtained dispersed phase particles (1) was measured using a particle size distribution analyzer (manufactured by Shimadzu Corporation, SALD-1).
000) was 50 μm.
The ion exchange capacity of the dispersed phase particles (1) was determined by neutralization titration and elemental analysis.
It was 6 mg equivalent / g and 5.7 mg equivalent / g by elemental analysis. When the water content in the dispersed phase particles (1) was measured using a Karl Fischer moisture meter (MPS-3P, manufactured by Kyoto Electronics Industry Co., Ltd.), it was 2.5 parts by weight. (Measurement of the average particle diameter, ion exchange capacity, and water content in the following Examples and Comparative Examples was performed in the same manner as in this Example.) 30 g of the obtained dispersed phase particles (1) were added to THERMS 300 (Nippon Steel Chemical Co., Ltd.). (Mixture of biphenyl and diphenyl ether manufactured by K.K.) is mixed and dispersed in 70 g of the electrorheological fluid composition of the present invention (hereinafter referred to as fluid composition (1)). ｝
I got

[0057]

Example 2 300 g of tetrachloroethane and 300 g of 98% by weight concentrated sulfuric acid were charged into a 2-liter four-neck separable flask equipped with a stirrer, a thermometer and a dropping funnel.
Cool to 0 ° C. using an ice bath and add 50 g of phosphorus pentoxide for stirring.
Was added over 30 minutes to form a uniform dispersion. Next, the ice bath was removed, and the crosslinked polymer (1) 5 obtained in Example 1 was removed.
0 g, and the temperature of the reaction mixture was raised to 60 ° C.
The mixture was heated and stirred at the same temperature for 8 hours to carry out a sulfonation reaction. Thereafter, the reaction mixture was poured into water at 0 ° C., filtered, and washed with water / acetone. The obtained solid was neutralized with 340 ml of a 10% by weight aqueous solution of potassium hydroxide, and then sufficiently washed with water. Next, it is dried at 80 ° C. for 10 hours using a vacuum drier, and the dispersed phase particles composed of 103 g of a spherical sulfonated polymer are hereinafter referred to as dispersed phase particles (2). I got｝.

When the average particle size of the obtained dispersed phase particles (2) was measured using a particle size distribution analyzer, it was 50 μm. When the ion exchange capacity of the dispersed phase particles (2) was quantified by neutralization titration and elemental analysis, it was 4.4 mg equivalent / g by neutralization titration and 4.5 mg equivalent / g by elemental analysis. The water content in the dispersed phase particles (2) was measured using a Karl Fischer moisture meter, and was 2.9 parts by weight.

30 g of the obtained dispersed phase particles (2) were mixed with 70 g of Shin-Etsu silicone oil KF96-20CS (dimethyl silicone oil manufactured by Shin-Etsu Chemical Co., Ltd.).
Dispersed, the electrorheological fluid composition of the present invention (hereinafter referred to as fluid composition (2)). I got｝.

[0060]

Example 3 1.2 liters of water was charged into a 3 liter four-neck separable flask equipped with a stirrer, a reflux condenser and a thermometer, and charged with Kuraray Povar PVA-205 (trade name).
Add 16.0 g of Kuraray's polyvinyl alcohol)
After dissolution, a mixture of 200 g of styrene, 70 g of chlorostyrene, 30 g of industrial divinylbenzene used in Example 1 and 5 g of benzoyl peroxide was further added. Thereafter, the contents in the flask were dispersed at a stirring speed of 400 rpm, and polymerized at 80 ° C. for 8 hours. The obtained solid was separated by filtration, sufficiently washed with water, and then dried at 80 ° C. for 12 hours using a hot air drier to obtain a spherical polymer crosslinked product (hereinafter referred to as polymer crosslinked product (2)). ｝ 285 g was obtained.

A 2-liter four-neck separable flask equipped with a stirrer, a thermometer and a dropping funnel was charged with chlorosulfuric acid.
The mixture was cooled to 0 ° C. using an ice bath, and 50 g of phosphorus pentoxide was added thereto over 30 minutes for stirring to obtain a uniform dispersion. Further, 50 g of the crosslinked polymer (2) was charged and then removed from the ice bath and stirred at room temperature (20 ° C.) for 12 hours. Then, the temperature of the reaction mixture was further raised to 80 ° C., and the mixture was heated at the same temperature for 2 hours. The sulfonation reaction was performed with stirring.
Thereafter, the reaction mixture was poured into water at 0 ° C., filtered,
Washed with water / acetone. 10% by weight of the obtained solid
After neutralization with 350 ml of an aqueous potassium hydroxide solution, the resultant was sufficiently washed with water. Then, at 80 ° C. for 10
After drying for 112 hours, the dispersed phase particles composed of 112 g of a spherical sulfonated polymer (hereinafter referred to as dispersed phase particles (3)). I got｝.

The average particle size of the obtained dispersed phase particles (3) was measured using a particle size distribution analyzer and found to be 66 μm. When the ion exchange capacity of the dispersed phase particles (3) was quantified by neutralization titration and elemental analysis, it was 5.3 mg equivalent / g by neutralization titration and 5.2 mg equivalent / g by elemental analysis. When the water content in the dispersed phase particles (3) was measured using a Karl Fischer moisture meter, it was 2.3 parts by weight.

30 g of the obtained dispersed phase particles (3) were mixed with 70 g of Shin-Etsu silicone oil KF96-20CS (dimethyl silicon oil manufactured by Shin-Etsu Chemical Co., Ltd.).
Dispersed, the electrorheological fluid composition of the present invention (hereinafter referred to as fluid composition (3)). I got｝.

[0064]

Example 4 A 2-liter four-neck separable flask equipped with a stirrer, a thermometer and a dropping funnel was charged with 500 g of 98% by weight concentrated sulfuric acid, cooled to 0 ° C. using an ice bath, and stirred for 5 minutes. 50 g of phosphorus oxide was added over 30 minutes to obtain a uniform dispersion. Next, the ice bath was removed, 50 g of the crosslinked polymer (2) obtained in Example 3 was charged, the temperature of the reaction mixture was raised to 70 ° C., and the mixture was heated and stirred at the same temperature for 12 hours to carry out a sulfonation reaction. Was. Thereafter, the reaction mixture was
The mixture was poured into water at ℃, filtered, and washed with water / acetone. The obtained solid was neutralized with 150 ml of a 10% by weight aqueous solution of lithium hydroxide, and then sufficiently washed with water. Next, it is dried at 80 ° C. for 10 hours using a vacuum drier, and the dispersed phase particles composed of 90 g of a spherical sulfonated polymer are hereinafter referred to as dispersed phase particles (4). I got｝.

The average particle size of the obtained dispersed phase particles (4) was measured using a particle size distribution analyzer to be 66 μm. When the ion exchange capacity of the dispersed phase particles (4) was determined by a neutralization titration method and an elemental analysis method, it was 5.2 mg equivalent / g by the neutralization titration method and 5.3 mg equivalent / g by the elemental analysis method. When the water content in the dispersed phase particles (4) was measured using a Karl Fischer moisture meter, it was 2.5 parts by weight.

30 g of the obtained dispersed phase particles (4) are mixed and dispersed in 70 g of bromobenzene, and the electrorheological fluid composition of the present invention (hereinafter referred to as fluid composition (4)). ｝
I got

[0067]

Example 5 1.2 liters of water was charged into a 3 liter four-neck separable flask equipped with a stirrer, a reflux condenser and a thermometer, and charged with Kuraray Povar PVA-205 (trade name).
Add 16.0 g of Kuraray's polyvinyl alcohol)
After dissolving, 140 g of styrene, 130 g of methoxystyrene, 30 g of industrial divinylbenzene used in Example 1 and azobisisobutyronitrile 5
g of the mixture was added. Then, the dispersing machine (rotation speed:
The content in the flask was dispersed using 5,000 rpm), and polymerized at 80 ° C. for 12 hours. The obtained solid was separated by filtration, sufficiently washed with water, and then heated at 80 ° C. for 1 hour using a hot air drier.
After drying for 2 hours, a spherical crosslinked polymer (hereinafter referred to as "polymerized crosslinked polymer (3)"). ｝ 291 g were obtained.

A 2-liter four-neck separable flask equipped with a stirrer, a thermometer and a dropping funnel was charged with 500 g of 98% by weight concentrated sulfuric acid and cooled to 0 ° C. using an ice bath. 50 g was added over 30 minutes to form a uniform dispersion. Next, the ice bath was removed, 50 g of the crosslinked polymer (3) was charged, the temperature of the reaction mixture was raised to 60 ° C., and the mixture was heated and stirred at the same temperature for 12 hours to carry out a sulfonation reaction. Thereafter, the reaction mixture was poured into water at 0 ° C., filtered, and washed with water / acetone. The obtained solid was neutralized with 50 g of pyridine, and then sufficiently washed with water. Next, the dispersion was dried at 80 ° C. for 10 hours using a vacuum dryer, and the dispersed phase particles composed of 124 g of a spherical sulfonated polymer (hereinafter referred to as dispersed phase particles (5)). I got｝.

When the average particle size of the obtained dispersed phase particles (5) was measured using a particle size distribution analyzer, it was 12 μm. When the ion exchange capacity of the dispersed phase particles (5) was quantified by neutralization titration and elemental analysis, it was 3.9 mg equivalent / g by neutralization titration and 4.0 mg equivalent / g by elemental analysis. The water content in the dispersed phase particles (5) was measured using a Karl Fischer moisture meter, and was 2.8 parts by weight.

30 g of the obtained dispersed phase particles (5) were mixed and dispersed in 70 g of THERM S900 (partially hydrogenated triphenyl manufactured by Nippon Steel Chemical Co., Ltd.) to obtain an electrorheological fluid composition of the present invention. ｛Hereinafter, this is referred to as a fluid composition (5). I got｝.

[0071]

Example 6 500 g of 98% by weight concentrated sulfuric acid was charged into a 2-liter four-neck separable flask equipped with a stirrer, a thermometer and a dropping funnel, cooled to 0 ° C. using an ice bath, and stirred for 5 minutes. 25 g of phosphorus oxide was added over 30 minutes to obtain a uniform dispersion. Next, the ice bath was removed, 50 g of the crosslinked polymer (3) obtained in Example 5 was charged, the temperature of the reaction mixture was raised to 80 ° C., and the mixture was heated and stirred at the same temperature for 12 hours to carry out a sulfonation reaction. Was. Thereafter, the reaction mixture was
The mixture was poured into water at ℃, filtered, and washed with water / acetone. The obtained solid was neutralized with 250 ml of a 10% by weight aqueous sodium hydroxide solution, and then sufficiently washed with water. Next, it was dried at 80 ° C. for 10 hours using a vacuum drier,
g of dispersed phase particles composed of a spherical sulfonated polymer, hereinafter referred to as dispersed phase particles (6). I got｝.

When the average particle diameter of the obtained dispersed phase particles (6) was measured by using a particle size distribution analyzer, it was 12 μm. When the ion exchange capacity of the dispersed phase particles (6) was quantified by neutralization titration and elemental analysis, it was 5.2 mg equivalent / g by neutralization titration and 5.3 mg equivalent / g by elemental analysis. The water content in the dispersed phase particles (6) was measured using a Karl Fischer moisture meter, and was 2.4 parts by weight.

30 g of the obtained dispersed phase particles (6) were mixed and dispersed in 70 g of THERM S300 (a mixture of biphenyl and diphenyl ether manufactured by Nippon Steel Chemical Co., Ltd.), and the electrorheological fluid composition of the present invention was used below. This is called a fluid composition (6). I got｝.

[0074]

Example 7 A 300 ml four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a dropping funnel was charged with 50 m of water.
1, 0.4 g of sodium lauryl sulfonate and 1.0 g of dodecane were charged, and the mixture was emulsified using a disperser. Further, 50 ml of water, 0.2% of sodium persulfate
g, 30 g of styrene, 15 g of methylstyrene and 15 g of the same industrial divinylbenzene as used in Example 1, and then heated at 50 ° C. for 8 hours with stirring to carry out polymerization to obtain 160 ml of an emulsion of seed particles. I got

Then, 1.2 liters of water was charged into a 3 liter four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a dropping funnel, and 160 ml of an emulsion of seed particles prepared above and sodium lauryl sulfonate were added. 2.8
After adding g, the mixture was uniformly dispersed with stirring. Thereafter, the mixture was heated to 70 ° C. while keeping the number of revolutions of the stirrer at 250, and 2 g of sodium persulfate dissolved in 10 ml of water was added. Then 120 g of styrene and 6 of methylstyrene
A mixture of 0 g and 60 g of industrial-use divinylbenzene used in Example 1 was added dropwise over 18 hours. Further, after reacting at the same temperature for 5 hours, the temperature was raised to 90 ° C., and the reaction was terminated after 3 hours. The solid content of the obtained dispersion was separated by filtration, and dried at 80 ° C. for 12 hours using a hot air drier to obtain a spherical polymer crosslinked product (hereinafter referred to as “polymerized crosslinked product (4)).
That. ｝ 267 g was obtained.

A 2-liter four-neck separable flask equipped with a stirrer, a thermometer and a dropping funnel was charged with 500 g of 98% by weight concentrated sulfuric acid, cooled to 0 ° C. using an ice bath, and stirred for phosphorus pentoxide. 100 g was added over 30 minutes to form a uniform dispersion. Next, the ice bath was removed, 50 g of the crosslinked polymer (4) was charged, the temperature of the reaction mixture was raised to 80 ° C., and the mixture was heated and stirred at the same temperature for 12 hours to carry out a sulfonation reaction. Thereafter, the reaction mixture was poured into water at 0 ° C., filtered, and washed with water / acetone. The obtained solid was neutralized with 240 ml of a 10% by weight aqueous sodium hydroxide solution, and then sufficiently washed with water. Next, it is dried at 80 ° C. for 10 hours using a vacuum dryer, and 106 g of dispersed phase particles composed of a spherical sulfonated polymer is hereinafter referred to as dispersed phase particles (7). I got｝.

The average particle size of the obtained dispersed phase particles (7) was measured using a particle size distribution analyzer, and was 5 μm. When the ion exchange capacity of the dispersed phase particles (7) was quantified by a neutralization titration method and an elemental analysis method, it was 5.4 mg equivalent / g by the neutralization titration method and 5.5 mg equivalent / g by the elemental analysis method. The water content in the dispersed phase particles (7) was measured using a Karl Fischer moisture meter, and was 2.7 parts by weight.

30 g of the obtained dispersed phase particles (7) were mixed with 70 g of Shin-Etsu silicone oil KF96-100CS (dimethyl silicone oil manufactured by Shin-Etsu Chemical Co., Ltd.).
Dispersed, the electrorheological fluid composition of the present invention (hereinafter referred to as fluid composition (7)). I got｝.

[0079]

Comparative Example 1 A 2-liter four-neck separable flask equipped with a stirrer, a thermometer and a dropping funnel was charged with 50 g of the crosslinked polymer (1) obtained in Example 1, and then 500 g of 98% by weight concentrated sulfuric acid. Was added to obtain a uniform dispersion. After raising the temperature of the reaction mixture to 80 ° C., the mixture was heated and stirred at the same temperature for 12 hours to carry out a sulfonation reaction. Thereafter, the reaction mixture was poured into water at 0 ° C., filtered, and washed with water / acetone. The obtained solid was neutralized with 200 ml of a 10% by weight aqueous sodium hydroxide solution, and then sufficiently washed with water. Next, the dispersion was dried at 80 ° C. for 10 hours using a vacuum drier, and this was referred to as Comparative Disperse Phase Particle (1), comprising 63 g of spherical sulfonated polymer for comparison. I got｝.

When the average particle size of the obtained comparative dispersed phase particles (1) was measured using a particle size distribution analyzer, it was found that the average particle size was 50 μm.
m. When the ion exchange capacity of the comparative dispersed phase particles (1) was quantified by a neutralization titration method and an elemental analysis method, the neutralization titration method was 3.3 mg equivalent / g, and the elemental analysis method was 3.
It was 2 mg equivalent / g. The water content in the comparative dispersed phase particles (1) was measured using a Karl Fischer moisture meter, and was 2.7 parts by weight.

30 g of the obtained comparative dispersed phase particles (1) were mixed and dispersed in 70 g of THERM S300 (a mixture of biphenyl and diphenyl ether manufactured by Nippon Steel Chemical Co., Ltd.) to prepare an electrorheological fluid composition for comparison. Hereinafter, this is referred to as comparative fluid composition (1). I got｝.

[0082]

Comparative Example 2 A 2-liter four-neck separable flask equipped with a stirrer, a thermometer and a dropping funnel was charged with 50 g of the polymerized crosslinked product (1) obtained in Example 1, and then 300 g of tetrachloroethane and 98 wt. 500 g of concentrated sulfuric acid was added to obtain a uniform dispersion. After raising the temperature of the reaction mixture to 60 ° C., the mixture was heated and stirred at the same temperature for 8 hours to carry out a sulfonation reaction. Thereafter, the reaction mixture was poured into water at 0 ° C.
After filtering off, it was washed with water / acetone. The obtained solid was neutralized with 210 ml of a 10% by weight aqueous solution of potassium hydroxide, and then sufficiently washed with water. Next, the dispersion was dried at 80 ° C. for 10 hours using a vacuum dryer, and comparative dispersed phase particles composed of 65 g of a spherical sulfonated polymer (hereinafter referred to as comparative dispersed phase particles (2)). I got｝.

When the average particle size of the obtained comparative dispersed phase particles (2) was measured using a particle size distribution analyzer, the average particle size was 50 μm.
m. The ion exchange capacity of the comparative dispersed phase particles (2) was determined by neutralization titration and elemental analysis. The neutralization titration was 2.6 mg equivalent / g, and the elemental analysis was 2.7.
mg equivalent / g. When the water content in the comparative dispersed phase particles (2) was measured using a Karl Fischer moisture meter,
It was 2.8 parts by weight.

30 g of the obtained comparative dispersed phase particles (2) were mixed with 70 g of Shin-Etsu silicone oil KF96-20CS (dimethyl silicone oil manufactured by Shin-Etsu Chemical Co., Ltd.).
An electrorheological fluid composition for comparison, which is hereinafter referred to as a comparative fluid composition (2). I got｝.

[0085]

Comparative Example 3 Amberlite IR-124, a sodium polystyrene sulfonate ion-type ion exchange resin
(Tokyo Organic Chemical Industry Co., Ltd.) using hot air dryer
After drying at 50 ° C. for 3 hours, the mixture is pulverized and classified to obtain amorphous comparative dispersed phase particles (hereinafter referred to as comparative dispersed phase particles (3)). I got｝.

The average particle size of the comparative dispersed phase particles (3) was measured using a particle size distribution analyzer and found to be 50 μm. When the ion exchange capacity of the comparative dispersed phase particles (3) was quantified by neutralization titration and elemental analysis, it was 4.4 mg equivalent / g by neutralization titration and 4.4 mg equivalent / g by elemental analysis. . The water content in the comparative dispersed phase particles (3) was measured using a Karl Fischer moisture meter.
Parts by weight.

30 g of the obtained comparative dispersed phase particles (3) were mixed with 70 g of Shin-Etsu silicone oil KF96-20CS (dimethyl silicon oil manufactured by Shin-Etsu Chemical Co., Ltd.).
An electrorheological fluid composition for comparison, which is hereinafter referred to as a comparative fluid composition (3). I got｝.

[0088]

Example 8 Each of the fluid compositions (1) to (7) and the comparative fluid compositions (1) to (3) obtained in Examples 1 to 7 and Comparative Examples 1 to 3 was rotated with a coaxial electric field. Put in the viscometer,
Shear stress value (initial value) when an external AC electric field of 4000 V / mm (frequency: 60 Hz) is applied under the conditions of an inner / outer cylinder gap of 1.0 mm, a shear rate of 400 s- ¹ and a temperature of 25 ° C.
The current density (initial value) flowing at that time was measured.

Further, the shear stress value (value after 7 days) and the 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 / mm applied were measured. The fluid composition was measured to determine the stability over time.

The results are shown in Table 1.

[0091]

[Table 1]

The electrorheological fluid has a higher shear stress value obtained when a relatively weak electric field is applied, and has a higher shear stress value. It is particularly preferable that both the shear stress characteristic and the current characteristic are excellent. Therefore, as a parameter for judging superiority by simultaneously evaluating the shear stress characteristic and the current characteristic, a ratio of a shear stress value obtained when a constant electric field is applied to a current density flowing at that time, that is, (shear stress value) / ( Current density) ｛
This value is called a Z value. ｝ Is effective. That is, an electrorheological fluid composition having both excellent shear stress characteristics and current characteristics has a large Z value. Table 1 also shows the calculation results of the Z value.

As is clear from Table 1, the fluid compositions (1) to (7) of the present invention can obtain a large shear stress even when a relatively weak electric field is applied, and the current density flowing at that time is small. The current characteristics were excellent, and the generated shear stress and current density were very excellent in stability over time. In addition, the fluid compositions (1) to (7) obtained in the present invention have an initial Z value of 1.6 or more, and are also excellent in stability over time of the balance between shear stress characteristics and current characteristics. It was found to be a viscous fluid composition.

On the other hand, comparative fluid compositions (1) and (2)
No large shear stress was obtained as compared with the fluid compositions (1) and (2) of the present invention, and the current density flowing at that time was large. Further, the stability of the generated shear stress and current density over time was poor, and measurement became impossible after 3 days. Moreover, the Z value was 0.7 even in the initial stage, and the balance between the shear stress characteristics and the current characteristics was worse than that of the fluid composition of the present invention.

In the comparative fluid composition (3), a large shear stress was not obtained, the current density flowing at that time was large, and the stability over time was poor, so that measurement was impossible after 3 hours. The Z value of the comparative fluid composition (3) was 0.2 at the initial stage, and the balance between the shear stress characteristics and the current characteristics was worse than that of the fluid composition of the present invention.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10N 40:04 40:08 40:14 60:10 70:00 Examiner Eriko Suzuki (58) Investigated field (Int.Cl. ⁶ C10M 151/02 B01J 13/00 C08L 25/18 C10M 107/46 C10N 20:06 C10N 40:04-40:14 C10N 60:10 C10N 70:00 WPI / L (QUESTEL)

Claims (1)

(57) [Claims] 1. A composition comprising a dispersed phase particle comprising a sulfonated polymer having an aromatic ring substituted by a sulfonic acid group, dispersed in an insulating dispersion medium, wherein the sulfonated polymer is vinyl. A polymerized crosslinked product (I) of a monomer mixture (A) containing an aromatic compound (a) and a polyvinyl compound (b) as main components and further adding another vinyl compound (c) as necessary, is prepared by adding a sulfonating agent and a pentavalent An electrorheological fluid composition obtained by sulfonating in the presence of a phosphorus compound of formula (I).