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US 4,992,190 AGranted
Fluid responsive to a magnetic field
AssigneeTRW Inc.
InventorEmil M. Shtarkman
Life of this patent
Estimating the term…
Abstract
A rheological fluid composition which is responsive to a magnetic field. The composition comprises magnetizable particulate, silica gel as a dispersant and a vehicle. A preferred magnetizable particulate is insulated, reduced carbonyl iron.
Claims11
A rheological fluid composition which is responsive to a magnetic field, which fluid composition comprises a mixture of carbonyl iron and silica gel comprising about 0.5-10% by weight of said silica gel and about 90% to 99.5% by weight of said carbonyl iron;
- and a vehicle in the amount of about 15%-50% of the weight of said mixture.
A rheological fluid composition which is responsive to a magnetic field comprising:
- a vehicle;
- a solid magnetizable carbonyl iron particulate suspended in said vehicle;
- a silica gel dispersant, said silica gel having a surface area, as measured by the BET method, of about 100 to about 300 square meters per gram of silica gel, and an average particle size diameter wherein less than 0.030 percent by weight is retained on a 100 mesh screen;
- the ratio of silica gel to carbonyl iron being about 0.5%-10% by weight silica gel to about 90%-99.5% by weight carbonyl iron;
- said vehicle being about 15%-50% by weight of the combination of silica gel and carbonyl iron.
2 more elements
Dependencies are inferred from the claim text.