公开(公告)号：GB2236761B

公开(公告)日：1993-09-15

申请号：GB9021831

申请日：1990-10-08

Applicant: BRIDGESTONE CORP

Inventor： KURACHI YASUO ,  OSAKI TOSHIYUKI ,  TANAKA MITSUYA ,  ISHINO YUICHI ,  SAITO TASKU

IPC: C10M171/00

Abstract: Electrorheological fluids display swift and reversible increase in apparent viscosity under application of an electrical potential difference to the fluid, and are composed generally of electrical insulating oily medium and dielectric fine-particles dispersed therein. At the initial stage of development, electrorheological fluids are prepared by dispersing water-carrying hydrophilic particulates in an electrical insulating oily medium. However, there are such defects as a restriction on usable temperatures so as to avoid evaporation or freezing of the water, an extreme increase in the electric current flow as the temperature raises, inferior stability caused by transfer of water etc. It is an object of the persent invention is to provide nonaqueous type electrorheological fluids having improved electrorheological property. The electrorheological fluid of the present invention is a nonaqueous type electrorheological fluid which comprises organic or inorganic particulates containing not more than 1 wt. % of water and dispersed in an oily medium superior in electrical insulation, wherein the improvement is that said fluid comprises from 0.001 wt. % to 10 wt. % of a compound having a functional group containing at least one atom selected from the group consisted of oxygen atom, nitrogen atom, sulfur atom and phosphorous atom.

公开(公告)号：GB2236761A

公开(公告)日：1991-04-17

申请号：GB9021831

申请日：1990-10-08

Applicant: BRIDGESTONE CORP

Inventor： KURACHI YASUO ,  OSAKI TOSHIYUKI ,  TANAKA MITSUYA ,  ISHINO YUICHI ,  SAITO TASKU

IPC: C10M171/00

Abstract: A nonaqueous type electrorheological fluid comprises organic or inorganic particulates containing not more than 1 wt.% of water and dispersed in an oily medium superior in electrical insulation, wherein the improvement is that said fluid comprises from 0.001 wt.% to 10 wt.% of a compound having a functional group containing at least one atom selected from the group consisted of oxygen atom, nitrogen atom, sulfur atom and phosphorous atom.

公开(公告)号：DE69009930T2

公开(公告)日：1995-01-19

申请号：DE69009930

申请日：1990-10-22

Applicant: BRIDGESTONE CORP

Inventor： KURACHI YASUO ,  TANAKA MITSUYA ,  ISHINO YUICHI ,  SAITO TASKU

IPC: C10M169/04 ,  C10M171/00 ,  C10M171/06 ,  C10N20/00 ,  C10N40/14

Abstract: Electrorheological fluids display swift and reversible increase in apparent viscosity under application of an electrical potential difference to the fluid, and are composed generally of electrical insulating oily medium and dielectric fine-particles dispersed therein. It is an object of the present invention to provide an electrorheological fluid capable of exhibiting enhanced electrorheological effect with smaller electric power consumption. Electrorheological fluid according to the present invention comprises particulates having a specific gravity of not smaller than 1.2 and water content of not larger than 4 wt.% dispersed in an electrical insulating oily medium having P=N bonds in the molecule.

公开(公告)号：DE69009930D1

公开(公告)日：1994-07-21

申请号：DE69009930

申请日：1990-10-22

Applicant: BRIDGESTONE CORP

Inventor： KURACHI YASUO ,  TANAKA MITSUYA ,  ISHINO YUICHI ,  SAITO TASKU

IPC: C10M169/04 ,  C10M171/00 ,  C10M171/06 ,  C10N20/00 ,  C10N40/14

Abstract: Electrorheological fluids display swift and reversible increase in apparent viscosity under application of an electrical potential difference to the fluid, and are composed generally of electrical insulating oily medium and dielectric fine-particles dispersed therein. It is an object of the present invention to provide an electrorheological fluid capable of exhibiting enhanced electrorheological effect with smaller electric power consumption. Electrorheological fluid according to the present invention comprises particulates having a specific gravity of not smaller than 1.2 and water content of not larger than 4 wt.% dispersed in an electrical insulating oily medium having P=N bonds in the molecule.

公开(公告)号：JPH03124794A

公开(公告)日：1991-05-28

申请号：JP26203089

申请日：1989-10-09

Applicant: BRIDGESTONE CORP

Inventor： KURACHI IKUO ,  OSAKI TOSHIYUKI ,  TANAKA MITSUYA ,  ISHINO YUICHI ,  SAITO TASUKU

IPC: F16F9/53 ,  C10M125/02 ,  C10M129/16 ,  C10M129/18 ,  C10M145/14 ,  C10M145/28 ,  C10M155/02 ,  C10M159/12 ,  C10M161/00 ,  C10M171/00 ,  C10N40/14 ,  H01B3/46

Abstract: PURPOSE:To obtain an electroviscous fluid with improved stability to an extract of rubber, resin or the like by dispersing particles with prescribed water and oxygen contents in an insulating oily medium in the presence of a compound with hydrophilic groups. CONSTITUTION:A non-aqueous electroviscous fluid containing 0.01 to 10wt.% compound with hydrophilic groups, which is obtained by dispersing organic or inorganic powder having a water content and an oxygen atom content of less than 1wt.% and less than 10wt.%, respectively, in an insulating oily medium. The compound with hydrophilic groups means a compound in which part or the whole of its molecule consists of hydrophilic functional groups. The compound is required to have an HLB value (representing the properties of a surfactant) of not less than 0.03. Examples of the group constituting a hydrophilic group include an ether bond, a carbonyl group, a hydroxy group, an amino group and a sulfone group.

公开(公告)号：JPH03157498A

公开(公告)日：1991-07-05

申请号：JP29483889

申请日：1989-11-15

Applicant: BRIDGESTONE CORP

Inventor： TANAKA MITSUYA ,  KURACHI IKUO ,  ISHINO YUICHI ,  SAITO TASUKU

IPC: C10M129/16 ,  C10M145/34 ,  C10M145/36 ,  C10M155/02 ,  C10N40/14 ,  C10N60/06

Abstract: PURPOSE:To obtain the subject fluid increasing electroviscous effect without increasing electric current in voltage-applying by dispersing O-containing organic or inorganic powder of low-water content and incorporating a specific amount an ether bond-containing compound thereinto. CONSTITUTION:0.01-10wt.% a compound having ether bond and preferably >=70 deg.C (especially >=100 deg.C) boiling point (e.g. an ethylene oxide-modified silicone, nonyl phenol or tetraethylene glycol) is contained in a non water-based electroviscous fluid composed of oily medium having excellent electrically insulating properties in which organic or inorganic powder containing

公开(公告)号：JPH03139599A

公开(公告)日：1991-06-13

申请号：JP27592689

申请日：1989-10-25

Applicant: BRIDGESTONE CORP

Inventor： KURACHI IKUO ,  TANAKA MITSUYA ,  ISHINO YUICHI ,  SAITO TASUKU

IPC: C10M169/04 ,  C10M171/00 ,  C10M171/06 ,  C10N20/00 ,  C10N40/14

Abstract: PURPOSE:To obtain an electroviscous fluid which can reveal a high electroviscous effect with less power consumption by using a phosphazene as an oily medium and a powder specified in both specific gravity and moisture content. CONSTITUTION:An electroviscous fluid comprising a dispersion of a powder in an oily medium excellent in electrical insulating properties, wherein a compound containing P=N bonds is used as the oily medium and a powder having a specific gravity of 1.2 or higher and a moisture content of 4wt.% or less is used as the powder. Compounds containing P=N bonds are a group of compounds generally called phosphazene, among which compounds selected from the following groups (1) and (2), having high chemical stability, excellent electrical insulating properties, and a melting point of below 40 deg.C are preferably used: (1) a group of compounds of a cyclic structure, having at least three P=N bonds in the molecule and (2) a group of compounds of a chain structure having continuously repeated P=N bonds. Examples of the powder include non-oxide powders, such as a carbon powder, as SiC powder, TiC powder, and a B4C powder, and oxide powders comprising zeolite, amorphous silica, barium titanate, etc.

公开(公告)号：JPH03139597A

公开(公告)日：1991-06-13

申请号：JP27592789

申请日：1989-10-25

Applicant: BRIDGESTONE CORP

Inventor： KURACHI IKUO ,  TANAKA MITSUYA ,  ISHINO YUICHI ,  SAITO TASUKU

IPC: C10M137/16 ,  C10N40/14

Abstract: PURPOSE:To stably raise the electroviscous effect without accompanied by an increase in current value by adding a specified amount of a phosphazene to an electroviscous fluid comprising a dispersion of an organic or inorganic powder in an oily medium. CONSTITUTION:An electroviscous fluid comprising a dispersion of an organic or inorganic powder in an oily medium excellent in electrical insulating properties, which has at least 0.001wt.% compound containing P=N bonds added thereto. Examples of the oily medium include a silicone oil, a mineral oil, and a paraffin oil, among which a silicone oil is preferably used because it can be used even when in direct contact with a material having rubber-like elasticity. Examples of the powder as the disperse phase include an SiC powder, a TiC powder, a B4C powder, and a carbonaceous powder. Compounds containing P=N bonds are generally called phosphazene and include the following three types: (1) a group of compounds of a cyclic structure, having at least three P=N bonds in the molecule; (2) a group of compounds of a chain structure having continuously repeated P=N bonds; and (3) a group of compounds of a three-dimensional network structure formed by P=N bonds.