The Dow Chemical Company

Dow Global Technolgoies LLC

Richard T Fox

Aleksander Jozef Pyzik

Robert Thomas Nilsson

Chan Han

Stephen D Dunmead

Warren H Griffin

Van-Chau Vo

David W Born

Uday V Deshmukh

Susan J Babinec

Kevin E Howard

Donald J Perettie

Ing-Feng Hu

Lawrence S Hood

Michael E Hus

Kevin J Nilsen

John Gordon-Duffy

Suzanne M Guerra

Roy E Smith

Mark A Chartier

Timothy G Fawcett

Vijay Wani

Dmitry P Dinega

Todd M Clarey

Aaron M Gabelnick

Ruseell B Peters, Jr

Chau-Van Vo

Chau-V Vo

Kendra M Giza

Prepare a closed-cell alkenyl aromatic polymer foam by an extrusion process using a blowing agent composition that contains at least 30 weight-percent of the chlorine-free hydrofluorocarbon blowing agent such that the foam has a density of 48 kilograms per cubic meter or less, contains more than 50 weight-percent styrene-acrylonitrile copolymer based on total polymer weight and at least eight weight-percent of a chlorine-free hydrofluorocarbon blowing agent that has a lower solubility in polystyrene than 1,1,2,2-tetrafluoroethane (HFC-134).

Alkenyl aromatic foam with low solubility hydrofluorocarbon

Alkenyl aromatic polymer foam comprising a polymer matrix containing one or more polymer and defining a plurality of cells having an average cell size wherein: (a) the alkenyl aromatic polymer foam has: &#x2014;(i) an average cell size that is in a range of 0.02 and 5 millimeters; &#x2014;(ii) a density of 64 kilograms per cubic meter or less; &#x2014;(iii) an open cell content less than 30 percent; and &#x2014;(iv) a cell size variation of 30% or less; and wherein the foam further comprises one or more fluorinated alkene blowing agent at a concentration of 0.03 moles or more and 0.3 moles or less per 100 grams of polymer foam.

Quality polymer foam from fluorinated alkene blowing agents

Disclosed is an electrically conductive thermoplastic polymer composition comprising a thermoplastic polymer and a synergistic combination of metal fibers and metal-coated fibers, structures made therefrom, and a process to make said compositions and structures.

Electrically conductive thermoplastic polymer composition

Disclosed is an electrically conductive thermoplastic polymer composition comprising a thermoplastic polymer, an impact modifier and a combination of metal fibers and metal-coated fibers, structures made therefrom, and a process to make said compositions and structures.

A process for creating plasma polymerized deposition on a substrate by a corona discharge is described. The corona discharge is created between an electrode and a counterelectrode supporting a substrate. A mixture of a balance gas and a working gas is flowed rapidly through the electrode, plasma polymerized by corona discharge, and deposited onto the substrate as an optically clear coating or to create surface modification. The process, which is preferably carried out at or near atmospheric pressure, can be designed to create an optically clear powder-free or virtually powder free deposit of polymerized plasma that provides a substrate with properties such as surface modification, chemical resistance, and barrier to gases.

Corona-generated chemical vapor deposition on a substrate

A ceramic-metal composite that is tough and stiff has been prepared and is comprised of an inert ceramic (e.g., alumina) embedded and dispersed in a matrix comprised of a metal (e.g., aluminum), a reactive ceramic (e.g., boron carbide) and a reactive ceramic-metal reaction product (e.g., AlB , Al BC, Al B C , AlB , Al C , AlB C or mixtures thereof) wherein grains of the inert ceramic have an average grain size greater than or equal to the average grain size of grains of the reactive ceramic. The ceramic-metal composite may be prepared by forming a mixture comprised of an inert ceramic powder (e.g., alumina) and a reactive ceramic powder (e.g., boron carbide), the inert ceramic powder having an average particle size equal to or greater than the average particle size of the reactive ceramic powder, forming the mixture into a porous body and consolidating the porous body in the presence of a metal (e.g., aluminum) to form the ceramic-metal composite.

Ceramic-metal composite and method to form said composite

A ceramic-metal composite that is tough and stiff has been prepared and is comprised of an inert ceramic (e.g., alumina) embedded and dispersed in a matrix comprised of a metal (e.g., aluminum), a reactive ceramic (e.g., boron carbide) and a reactive ceramic-metal reaction product (e.g., AlB,, Al,BC, Al,B,C,, AlB,, Al,C,, AlB,C,or mixtures thereof) wherein grains of the inert ceramic have an average grain size greater than or equal to the average grain size of grains of the reactive ceramic. The ceramic-metal composite may be prepared by forming a mixture comprised of an inert ceramic powder (e.g., alumina) and a reactive ceramic powder (e.g., boron carbide), the inert ceramic powder having an average particle size equal to or greater than the average particle size of the reactive ceramic powder, forming the mixture into a porous body and consolidating the porous body in the presence of a metal (e.g., aluminum) to form the ceramic-metal composite.

A process for preparing complex-shaped, ceramic-metal composite articles, comprising: (a) contacting a non-wettable powder that is non-wetting to a metal to be used for infiltration with a shaped ceramic body to form a layer of the non-wettable powder on one or more surfaces of the shaped ceramic body, wherein the shaped ceramic body has a region where there is no layer of the non-wettable powder, and (b) infiltration the shaped ceramic body with the metal through the region or regions where there is no layer of the non-wettable powder, such that a complex-shaped ceramic-metal composite comprising one or more metal phases and one or more ceramic phases is formed, wherein the article has substantially the net shape of the shaped ceramic body and undesirable regions of excess metal on the surface and undesirable phases within the complex-shaped ceramic-metal composite article near the surface are located only in the region or regions where there is no layer of the non-wettable powder. The process of the invention allows the preparation of complex-shaped ceramic-metal composite articles with undesirable regions of excess metal and undesirable phases on the surface(s), of, or within, the article only in the regions where there is, or was, no layer of non-wettable powder. The process of the invention allows the preparation of a complex-shaped ceramic-metal composite article which requires little or no machining of the surface(s) to achieve a finished article. A complex-shaped ceramic-metal composite article is prepared which contains few undesirable regions of excess metal and undesirable phases.

Method of controlling infiltration of complex-shaped ceramic-metal composite articles and the products produced thereby

The invention is a complex-shaped article, comprising an article prepared by joining at least one multi-phase ceramic-metal part and at least one shaped part of another material, wherein the theoretical density of the at least one ceramic-metal part is greater than 80 percent. In another aspect, the invention is a process for preparing complex-shaped articles, comprising:

Method of preparing complex-shaped ceramic-metal composite articles and

A process for preparing complex-shaped, ceramic-metal composite articles, comprising:

Method of controlling infiltration of complex-shaped ceramic-metal

A tungsten carbide-containing material in which the tungsten carbide has the general formula, W.sub.x C, wherein x is greater than one and less than two and the material has less than 0.20 weight percent cobalt, a density of at least about 97% of its theoretical density, and a Vickers hardness of at least about 2400 kg/mm.sup.2.

Sintered WC-containing materials

Hard disk drive components, such as, sliders, load beams, support arms, actuators, actuator bearings, spacers, clamps, spindles, ball bearings, thrust bearings, journal bearings, base plates, housings, and covers, formed of a multi-phase ceramic-based material. One method of making the hard disk drive components includes (a) forming a porous body of ceramic; (b) infiltrating a liquid into the pores of the ceramic body; (c) solidifying the infiltrated liquid; and (d) machining the metal-infiltrated ceramic body to form the hard disk drive component.

Hard disk drive components and methods of making same

A method of forming a low level carbon high-density tungsten carbide-containing material includes sintering a preform which contains tungsten carbide powder and has a composition such that the resulting sintered material has at most 6.05 weight percent tungsten-bound carbon based on the total weight of tungsten and tungsten-bound carbon. This low level of carbon may be achieved by, prior to the sintering step, oxidizing the tungsten carbide powder sufficiently to achieve the desired substoichiometric carbon level in the sintered product or by adding a carbon-lowering material selected from the group consisting of tungsten, ditungsten carbide, and tungsten oxide. Optionally, other materials can be present in the preform such as carbon-getter metals and compounds thereof. The carbon-getter metals are those metals of which the carbides thereof are more thermodynamically stable than monotungsten carbide.

Growing community of inventors

Midland, MI, United States of America

Richard T Fox