公开(公告)号：JPH08143886A

公开(公告)日：1996-06-04

申请号：JP29102694

申请日：1994-11-25

Applicant: BRIDGESTONE CORP

Inventor： MIYANO MARI ,  SAKURAI MAKOTO ,  SHII HAWAADO ,  SAITO TASUKU

IPC: C10M169/04 ,  C10N20/02 ,  C10N30/04 ,  C10N40/14 ,  C10N60/00 ,  C10N60/06 ,  C10N70/00

Abstract: PURPOSE: To obtain the subject fluid consisting of a specific carbonaceous pow der and silicone oil, excellent in electroviscus characteristics in wide temperature area, having low initial viscosity, free from settling of disperse phase, excellent in re-dispersibility, long-term dispersibility, long-term stability and responsiveness in application of electric field and requiring a small consumed power. CONSTITUTION: This fluid comprises (A) 1-60wt.% of carbonaceous powder having dielectric (e.g. carbonaceous powder having 0.01-100μm average particle diameter and obtained by carrying out thermal polymerization of a condensed polycyclic aromatic compound consisting essentially of naphthalene as a main component in the presence of HF/BF3 catalyst, carrying out heat treatment of the resultant 100% mesophase pitch having 150-400 deg.C softening point at a temperature of 50-400 deg.C not higher than its melting point in an oxidizing atmosphere so as to give 5-25wt.% oxygen content in the pitch, then carrying out heat treatment of the pitch at 300-700 deg.C in an inert gas atmosphere to carbonize the pitch so as to give 3-20wt.% oxygen content in the pitch) and (B) a modified silicone oil (e.g. a polyether-modified, epoxy-modified, methacrylic acid-modified or carbinol-modified silicone oil) contained in an amount of 0.1-20% based on the component A and having 0.65-1000cSt viscosity at 25 deg.C.

公开(公告)号：JPH07207292A

公开(公告)日：1995-08-08

申请号：JP17038794

申请日：1994-06-30

Applicant: BRIDGESTONE CORP

Inventor： MARUYAMA TAKAYUKI ,  OGINO TAKAO ,  SAITO TASUKU ,  SHII HAWAADO ,  MIYANO MARI

IPC: C01B31/02 ,  C10C3/02 ,  C10M125/02 ,  C10M169/04 ,  C10M177/00 ,  C10N20/00 ,  C10N20/02 ,  C10N20/06 ,  C10N30/00 ,  C10N40/14 ,  C10N60/00 ,  C10N60/10 ,  C10N70/00

Abstract: PURPOSE:To obtain carbonaceous powder which can give an electroviscous fluid of reduced electric consumption when used as the disperse phase of the fluid. CONSTITUTION:This powder is prepared by adding a cross-linking agent to a thermoplastic pitch obtained by polymerizing a fused polycyclic aromatic hydrocarbon based on naphthalene in the presence of a Lewis acid, heating the mixture to render the pitch thermosetting, and optionally heat-treating the same to adjust the ratio of the number of the carbon atoms to that of the hydrogen atoms (C/H) to 1.5-3.5 and adjust the mean particle diameter to 0.01-50mum. The electroviscous fluid comprises 1-60vol.% disperse phase comprising this powder and 40-99vo.% liquid phase comprising an electrical insulating oil having a viscosity of 0.65-1000cSt at room temperature.

公开(公告)号：JPH08176584A

公开(公告)日：1996-07-09

申请号：JP32612694

申请日：1994-12-27

Applicant: BRIDGESTONE CORP

Inventor： MIYANO MARI ,  SHII HAWAADO ,  SAITO TASUKU

IPC: C10M169/04 ,  C08L83/04 ,  C10N40/14

Abstract: PURPOSE: To obtain an electroviscous fluid showing high electroviscous fluid effect with low power consumption. CONSTITUTION: A disperse phase in an amount of 1-50vol.% comprising dielectric particles is dispersed into 50-99vol.% of a liquid phase composed of an oily medium which is a siloxane polymer containing 0-90mol% dimethylsiloxane and 10-100mol% 3,3,3-trifluoropropylmethylsiloxane and has >=10 Ω.m volume resistivity and in an amount of 0.1-20wt.% based on the dielectric particles of a polyether-modified silicone. The dielectric particles are preferably carbonaceous powder obtained by heat-treating 100% mesophase pitch as a raw material in an oxidizing atmosphere and then carbonizing.