Lord Corporation

Dow Corning Corporation

Keith D Weiss

J David Carlson

Cecil L Frye

Donald A Nixon

Loren A Haluska

Theodore G Duclos

Ronald H Baney

Kirk J Abbey

Harold L Vincent

Lynn C Yanyo

Michael J Chrzan

Joseph E Bares

Anthony J Margida

A magnetorheological fluid that includes a carrier component and a magnetizable particle component wherein the magnetizable particle component is a mixture of at least a first particle group having an average particle diameter and a second particle group having an average particle diameter wherein the average particle diameter of said first particle group is 3 to 15 times larger than the average particle diameter of said second particle group.

Method and magnetorheological fluid formulations for increasing the

A magnetorheological fluid that includes a carrier component and a magnetizable particle component wherein the magnetizable particle component has a fractional packing density of at least 0.50 prior to formulation into the magnetorheological fluid. Use of this magnetorheological fluid can increase the force output of a magnetorheological device without increasing the viscosity of the fluid because the particle volume concentration in a working gap of the device increases when a magnetic field is applied.

A magnetorheological material containing a carrier fluid, a particle component and a thixotropic additive to provide stability against particle settling. The thixotropic additive can be a hydrogen-bonding thixotropic agent, a polymer-modified metal oxide, or a mixture thereof. The utilization of a thixotropic additive creates a thixotropic network which is unusually effective at minimizing particle settling in a magnetorheological material.

Thixotropic magnetorheological materials

A magnetorheological material containing a particle component and a carrier fluid or mixture of carrier fluids having a change in viscosity per degree temperature (.DELTA..eta./.DELTA.T ratio) less than or equal to about 16.0 centipoise/.degree.C. over the temperature range of about 25.degree. C. to -40.degree. C. The magnetorheological material exhibits a substantial magnetorheological effect and excellent lubricating properties with a minimal variation in mechanical properties with respect to changes in temperature. The magnetorheological material is advantageous in that it provides for the design of devices that are smaller, more efficient and consume less power.

Temperature independent magnetorheological materials

d A magnetorheological material containing a carrier fluid and a magnetically active particle. The particle has been modified so that the surface of the particle is substantially free of contamination products. The contamination products are removed from the surface of the particle by abrader processing, chemical treatment or a combination thereof. Magnetorheological materials prepared using the particles from which contamination products have been removed exhibit significantly enhanced magnetorheological effects.

Magnetorheological materials utilizing surface-modified particles

Controllable composite structure or structural elements enclose magnetotheological fluids as a structural component between opposing containment layers to form at least a portion of any variety of extended mechanical systems, such as plates, panels, beams and bars or structures including these elements. The control of the stiffness and damping properties of the structure or structural elements is accomplished by changing the shear and compression/tension moduli of the magnetorheological fluid by varying the applied magnetic field. The composite structures of the present invention may be incorporated into a wide variety of mechanical systems for control of vibration and other properties.

Magnetorheological fluid composite structures

Disclosed is a method of forming a coating on a substrate. The method comprises applying a silane and, optionally, a titanium catalyst, onto the substrate and allowing the silane to hydrolyze and condense with atmospheric moisture to form an insoluble coating.

Method for forming an insoluble coating on a substrate

An electrorheological material comprising a carrier fluid and an atomically, polarizable particle component. The atomically polarizable particle component has a crystalline lattice structure which allows atoms to shift position with respect to each other in response to the application of an electric field. The electrorheological materials are subjected to an alternating current electric field at a frequency of at least 500 Hz. The materials exhibit substantial electrorheological activity over a broad temperature range.

Method for activating atomically polarizable electrorheological materials

A magnetorheological material containing a carrier fluid and an iron alloy particle component. The particle component can be either an iron-cobalt alloy or an iron-nickel alloy. The iron-cobalt alloy has an iron:cobalt ratio ranging from about 30:70 to 95:5 while the iron-nickel alloy has an iron:nickel ratio ranging from about 90:10 to 99:1. The iron alloy particle components are capable of imparting high yield stress capability to magnetorheological materials.

Magnetorheological materials based on alloy particles

An electrorheological material containing a carrier fluid and an ionic dye particle component which is an ionically charged compound based on or derived from a conjugated hydrocarbon compound. A preferred ionically charged compound contains at least one aromatic nucleus that has been sulfonated and/or carboxylated to form a negatively charged system which has, in turn, been offset with a positive ion. The electrorheological material is useful for creating aesthetic visual effects and responds quickly to an electric field.

Ionic dye-based electrorheological materials

An electrorheological material comprising a carrier fluid and an atomically polarizable particle component. The atomically polarizable particle component has a crystalline lattice structure which allows atoms to shift position with respect to each other in response to the application of an electric field. The electrorheological materials are subjected to an alternating current electric field at a frequency of at least 500 Hz. The materials exhibit substantial electrorheological activity over a broad temperature range.

Atomically polarizable electrorheological material

The present invention relates to soluble perhydrosiloxane copolymers of the formula [H.sub.2 SiO].sub.x [HSiO.sub.3/2 ].sub.y wherein the mole fractions x and y total 1. In addition, the present invention relates to the use of these novel copolymers as coating materials, especially for use on electronic devices.

Perhydrosiloxane copolymers and their use as coating materials

The present invention provides a relatively simple synthesis procedure for the formation of silane hydrolyzate compositions of the formula ##STR1## where R is hydrogen or a methyl group, n is an integer greater than about 8, and x is a number between 0 and 2. The hydrolyzate compositions are metastable in solvent solution, but become insoluble after coating on a substrate. The resins are useful as planarizing coatings for substrates such as electronic devices and can be ceramified by subjecting them to an oxidizing atmosphere at a temperature of between about 100.degree. to 1000.degree. C. to form ceramic or ceramic-like coatings on such substrates.

Process for forming a coating on a substrate using a silsesquioxane resin

The present invention provides a relatively simple synthesis procedure for the formation of silane hydrolyzate compositions of the formula ##EQU1## where R is hydrogen or a methyl group, n is an integer greater than about 8, and x is a number between 0 and 2. The hydrolyzate compositions are metastable in solvent solution, but become insoluble after coating on a substrate. The resins are useful as planarizing coatings for substrates such as electronic devices and can be ceramified by subjecting them to an oxidizing atmosphere at a temperature of between about 100.degree. to 1000.degree. C. to form ceramic or ceramic-like coatings on such substrates.

Metastable silane hydrolyzates

The present invention provides a relatively simple synthesis procedure for the formation of silane hydrolyzate compositions of the formula ##EQU1## where R is hydrogen or a methyl group, n is an integer greater than about 8, and x is a number between 0 and 2. The hydrolyzate compositions are metastable in solvent solution but become insoluble after coating on a substrate. The resins are useful as planarizing coatings for substrates such as electronic devices and can be ceramified by subjecting them to an oxidizing atmosphere at a temperature of between about 100.degree. to 1000.degree. C. to form ceramic or ceramic-like coatings on such substrates.

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Cary, NC, United States of America

Keith D Weiss