The B. F. Goodrich Company

Gencorp, Inc.

Rjf International Corporation

Tiong H Kuan

Raymond C Srail

Thomas R Szczepanski

Richard A Glover

A flexible magnetic blend composition is provided which is comprised of high energy rare earth magnetic particles in a flexible high temperature resistant and oil resistant polymer binder. The binder system preferably comprises a highly saturated nitrile rubber (HSN) or a polymer alloy of the same in which a HSN is the major polymer and also contains additives which are compatible with processing, subsequent electron beam curing, and final product performance. The binder system is high loaded, usually from about 50 to about 70 volume percent, with the high energy rare earth magnetic particles, which can produce bonded magnets with a maximum energy product of at least 2.5 megagauss-oersteds, a remenance, B.sub.r of at least 3400 gauss, a coercive force, Hc, of at least 2900 oersteds and an intrinsic coercivity, Hci, of at least 5000 oersteds. The process for production of this system involves the binder system and rare earth magnetic particles being mixed and then formed into a final geometry before being cured by high voltage electron beam radiation. The electron beam curing in the solid state fixes dimensional stability, magnetic properties, and oil, solvent and chemical resistance of the part even when exposed to subsequent hostile temperature environments of 100.degree. C. or higher. Further, the HSN binder system reduces oxidation of the rare earth magnetic particles from subsequent hot air aging when compared to conventional nitrile elastomer binder system. Any off geometry parts or trim produced in the process prior to radiation curing can be recycled through processing several times without fear of premature cure.

Flexible high energy magnetic blend compositions based on rare earth

A flexible magnetic blend composition is provided which is comprised of high energy ferrite magnetic particles in a flexible high temperature resistant and oil resistant polymer binder. The binder system is preferably a highly saturated nitrile rubber (HSN) or a polymer alloy of the same in which a HSN is the major polymer containing alloying polymers and/or additives which are compatible with processing, subsequent electron beam curing, and final product performance. The binder system is highly loaded usually from 55 to 65 volume percent with the high energy ferrite particles, i.e., barium and/or strontium ferrite particles, which can produce bonded magnets with a maximum energy product of at least 1.0 megagauss-oersteds, a remenance, Br, of at least 2000 gauss, a coercive force, H.sub.c, of at least 1800 oersteds, and an intrinsic coercivity, H.sub.ci, of at least 2000 oersteds. The process for production of this system involves the binder system and ferrite particles being mixed, the ferrite particles oriented in a preferred direction during processing, then formed into a final geometry before being cured by high voltage electron beam radiation, preferably in excess of 3,000,000 electron volts. The electron beam curing in the solid state fixes dimensional stability, magnetic properties, oil, solvent, and chemical resistance of the part even when exposed to subsequent hostile temperature environments of 125.degree. C. or higher. Any off geometry parts or trim produced in the process prior to radiation curing can be recycled through processing several times without fear of premature cure.

Flexible high energy magnetic blend compositions based on ferrite

Crystalline elastomeric network compositions are transformable from their original cured shape into an altered shape and subsequently back to their original shape. The transformation process, which is repeatable, is effected by the simultaneous application of heat and deformation forces. The amount of heat required, expressed in terms of temperature, is relatively low. The shape-transformable compositions of the present invention are single phase blends of one or more crystalline polymers and one or more elastomer polymers. The compositions generally have a single broad endotherm due probably to the co-crystallization of the different crystalline segments, a low glass transition temperature, and a low transformation temperature, that is generally less than 100.degree. C.

Single phase shape-transformable elastomeric compounds

A low rate resilient bushing suitable for automobiles and other vehicles is disclosed where in the bushing, the carbon black reinforced rubber compound has been conventionally sulfur cured using an activator system of zinc oxide and certain soluble fatty acid materials.

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Hudson, OH, United States of America

Tiong H Kuan