Patents Represented by Attorney D. R. Howard
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Patent number: 5089447Abstract: A powdered admixture of a metal and its boron, carbon, nitrogen or silicon derivative is, when subjected to densification conditions, partially reacted and converted to a hard, wear resistant material. Such a material, when formed from an admixture of tungsten carbide and tungsten, contains tungsten monocarbide and (di-tungsten) carbide. Other choices of metal and metal derivatives produce at least one compound having a stoichiometry which differs from that of starting metal derivative. Articles formed from this material can be useful as, for example, nozzles in abrasive or nonabrasive waterjet cutting machines and various parts of wire drawing apparatus.Type: GrantFiled: October 9, 1990Date of Patent: February 18, 1992Assignee: The Dow Chemical CompanyInventors: Edward E. Timm, Ann M. McCombs
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Patent number: 5059563Abstract: Metal boride powders can be produced with a predetermined particle size by controlling reaction conditions. The metal boride powder is produced by reacting a solid boron source, a metal source and a reductant under conditions sufficient to produce a metal boride powder with a particle size correlating to that of the solid boron source. The reaction is preferably stopped after the formation of products but before any appreciable crystal growth occurs.Type: GrantFiled: July 12, 1988Date of Patent: October 22, 1991Assignee: The Dow Chemical CompanyInventors: Bijan Khazai, William G. Moore
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Patent number: 4999338Abstract: Subject a heated, non-molten, intimate admixture of a base metal and a superconducting oxide material to pressure sufficient to form a densified article. The densified article is either superconducting as formed or capable of being rendered superconducting by annealing in the presence of oxygen. Depending upon the choice of materials the densified article is stable at temperatures up to 1000.degree. C.Type: GrantFiled: February 23, 1990Date of Patent: March 12, 1991Assignee: The Dow Chemical CompanyInventors: Sunil D. Wijeyesekera, Robert H. Heistand, II
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Patent number: 4923512Abstract: Cobalt-bound tungsten carbide metal matrix composites having a unique microstructure are produced by consolidating partially sintered greenware under high pressures, e.g., 120,000 psi, at temperatures less than those used for conventional liquid phase sintering in a relatively short time, e.g., from less than one minute to less than about one hour. The composites have a binder phase which contains less than about 80 weight percent of the tungsten found in a composite prepared from the same or similar compositions via liquid phase sintering. These composites provide cutting tools with both toughness and wear resistance which exceed that of cutting tools made from the same or similar compositions via liquid phase sintering.Type: GrantFiled: April 7, 1989Date of Patent: May 8, 1990Assignee: The Dow Chemical CompanyInventors: Ed E. Timm, Douglas B. Schwarz
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Patent number: 4919689Abstract: A process for preparing a self-reinforced silicon nitride ceramic body of high fracture toughness comprising hot-pressing a powder mixture containing silicon nitride, magnesium oxide, yttrium oxide and calcium oxide under conditions such that densification and the in situ formation of .beta.-silicon nitride whiskers having a high aspect ratio occur. A novel silicon nitride ceramic of high fracture toughness is disclosed comprising a .beta.-silicon nitride crystalline phase wherein at least about 20 volume percent of the phase is in the form of whiskers having an average aspect ratio of at least about 2.5; a glassy second phase containing magnesium oxide, yttrium oxide, calcium oxide, and silica in a total amount not greater than about 35 weight percent; and not greater than about 10 weight percent of the total weight as other phases.Type: GrantFiled: February 28, 1989Date of Patent: April 24, 1990Assignee: The Dow Chemical CompanyInventors: Aleksander J. Pyzik, Douglas B. Schwarz, William J. Dubensky, Donald R. Beaman
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Patent number: 4910245Abstract: Thermoplastic vulcanizates are prepared by curing, at least partially by dynamic vulcanization, blends of chlorinated polyethylene and crystalline thermoplastic polymers such as polypropylene. Inclusion of a plasticizing material or extender oil, e.g. trioctyl trimellitate, enhances softness and oil resistance of the blends. Vulcanizing materials include a basic material, normally added with the chlorinated polyethylene, and (1) a derivative of 2,5-dimercapto-1,3, 4-thiadiazole or (2) a combination of 2,5-dimercapto-1,3,4-thiadiazole and an activator material such as an amine having a boiling point of 110.degree. C. or higher and a pk value less than 4.5.Type: GrantFiled: April 7, 1988Date of Patent: March 20, 1990Assignee: The Dow Chemical CompanyInventors: James H. Flynn, Oliver C. Ainsworth, Robert R. Blanchard
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Patent number: 4869827Abstract: This invention relates to an improved composition and method which inhibit the corrosion of and the formation of scale on metals present in an aqueous system. The composition comprises a water soluble copolymer having moieties derived from acrylic acid and from lower alkyl hydroxy acrylates, and a combination of a manganese compound and an aminoalkylenephosphonic acid derivative or its salts.Type: GrantFiled: May 18, 1988Date of Patent: September 26, 1989Assignee: The Dow Chemical CompanyInventors: Harold A. Chagnard, Jr., Mark K. Brayden, Thomas R. LeBlanc
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Patent number: 4867759Abstract: Abrasive greenware having improved strenght is prepared using a binder comprising poly(ethyloxazoline).Type: GrantFiled: December 18, 1987Date of Patent: September 19, 1989Assignee: The Dow Chemical CompanyInventors: Lawrence W. Tiefenbach, Jr., James E. Schuetz, Thomas T. Chiu
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Patent number: 4864047Abstract: This invention relates to a process for preparing compounds of the formula,N.sub.3 P.sub.3 (R.sub.1).sub.n (R.sub.2).sub.6-nwherein R.sub.1 is an aminophenoxide; R.sub.2 has up to 6 carbon atoms and is an alkoxy, an alkenoxy, a fluoro-substituted alkoxy, a fluoro-substituted alkenoxy or an aryloxy radical; and n is a whole integer .gtoreq.1 and .ltoreq.6. The process comprises reacting a chlorocyclotriphosphazene with an R.sub.1 salt to form an R.sub.1 -chlorocyclotriphosphazene which is further reacted with an R.sub.2 salt.Novel compounds of the formula,N.sub.3 P.sub.3 (R.sub.1).sub.n Cl.sub.6-nare also disclosed.Type: GrantFiled: December 23, 1987Date of Patent: September 5, 1989Assignee: The Dow Chemical CompanyInventor: Massimo D. Bezoari
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Patent number: 4830994Abstract: Greenware having improved green strength is prepared using poly(ethyloxazoline) as a binder.Type: GrantFiled: December 18, 1987Date of Patent: May 16, 1989Assignee: The Dow Chemical CompanyInventor: James E. Schuetz
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Patent number: 4786689Abstract: A process is provided for metallating ethylene polymers which have polymerized therein a minor amount of nonconjugated diene. Metallation is accomplished with a blend of three metallating reagents: (a) an alkyllithium compound; (b) a potassium alkoxide; and (c) a chelating tertiary diamine. The metallated polymers so prepared may be reacted with one or more anionically polymerizable monomers to form graft polymers or with a reagent such as carbon dioxide to form a functionalized polymer. When the anionically polymerizable monomer has two or more polymerizable sites, the metallated polymer is reacted with a modifying compound such as alpha-methylstyrene before it is reacted with the monomer(s). Certain of the graft polymers behave as thermoplastic elastomers whereas others are thermoplastic. The blend of metallating reagents may be used with any polymer having partial or complete unsaturation.Type: GrantFiled: October 16, 1987Date of Patent: November 22, 1988Assignee: The Dow Chemical CompanyInventors: Gary K. Lund, Raymond L. Laakso, Jr., Calvin P. Esneault, Brian W. Walther
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Patent number: 4775580Abstract: A process for preparing a porous random fiber polymeric composite sheet through the addition of a cellulose ether which is selectively soluble or insoluble to a random fiber composite slurry under conditions such that the cellulose ether is insoluble, forming the slurry into a sheet, fusing the organic polymer component of the sheet and heating the sheet to solubilize the cellulose ether whereby voids are formed in the sheet. Before the sheet is treated to remove the cellulose ether, it may be combined with other sheets and densified under heat and pressure. Before removing the cellulose ether, the densified sheet may be heated under reduced pressure to expand or loft the sheet in a direciton normal to the plane of the sheet. A random fiber polymeric composite sheet, a densified sheet and a lofted sheet, each comprising a binder, fusable organic polymer, reinforcing material and a cellulose ether are also provided. The same sheets after removal of the cellulose ether are further provided.Type: GrantFiled: May 5, 1987Date of Patent: October 4, 1988Assignee: The Dow Chemical CompanyInventor: Gaylon L. Dighton
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Patent number: 4767823Abstract: Halogenated polyethylene resins and halogenated ethylene polymer resins having a reduced tendency to "block" are provided. The halogenated resins are prepared respectively from polyethylene and ethylene polymer starting materials which have a weight-based median particle size of from about 120 to about 600 microns and a weight-based particle size distribution such that more than 60 percent of the particles have a particle size of from about 130 to about 850 microns. The halogenated resins also have a weight-based median particle size of from about 200 to about 900 microns. The halogenated polyethylene resins have a chemically combined halogen content of from about 26 to about 42 weight percent whereas the halogenated ethylene polymer resins have a chemically combined halogen content of from about 15 to about 28 weight percent.Type: GrantFiled: August 1, 1986Date of Patent: August 30, 1988Assignee: The Dow Chemical CompanyInventors: Edward Jones, Larry A. Meiske, Warren L. Young
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Patent number: 4765915Abstract: A method for filtering liquid or gaseous materials where the filtration is conducted with a porous filter media prepared from an aqueous wet-laid, lofted fiber-reinforced composite sheet, the composite sheet comprising a heat fusible polymer, reinforcing fibers and a binder. The random fiber composite sheet can be selectively lofted or recompressed to form filter media having variable porosity. Also, a membrane support means prepared by applying or treating the fiber-reinforced composite sheet with a discriminating membrane layer.Type: GrantFiled: April 14, 1986Date of Patent: August 23, 1988Assignee: The Dow Chemical CompanyInventor: Charles F. Diehl
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Patent number: 4761456Abstract: A process is provided for metallating ethylene polymers which have polymerized therein a minor amount of nonconjugated diene. Metallation is accomplished with a blend of three metallating reagents: (a) an alkyllithium compound; (b) a potassium alkoxide; and (c) a chelating tertiary diamine. The metallated polymers so prepared may be reacted with one or more anionically polymerizable monomers to form graft polymers or with a reagent such as carbon dioxide to form a functionalized polymer. When the anionically polymerizable monomer has two or more polymerizable sites, the metallated polymer is reacted with a modifying compound such as alpha-methylstyrene before it is reacted with the monomer(s). Certain of the graft polymers behave as thermoplastic elastomers whereas others are thermoplastic. The blend of metallating reagents may be used with any polymer having partial or complete unsaturation.Type: GrantFiled: August 18, 1986Date of Patent: August 2, 1988Assignee: The Dow Chemical CompanyInventors: Gary K. Lund, Calvin P. Esneault
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Patent number: 4753971Abstract: Peroxide vulcanizable chlorinated polyethylene compositions can, after being press cured at a temperature of 204.degree. Centigrade for a period of ten minutes, withstand ozone-induced cracking for a period of 168 hours or more when elongated 60% and exposed to 200 parts of ozone per hundred million parts of air at a temperature of 400.degree. Centigrade.Type: GrantFiled: July 10, 1987Date of Patent: June 28, 1988Assignee: The Dow Chemical CompanyInventors: William H. Davis, Jr., Raymond L. Laakso, Jr., Michael E. Price
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Patent number: 4751147Abstract: Chlorinated polyethylene resins which are semicrystalline yet of sufficiently low viscosity to be processible on conventional extrusion equipment are provided. The resins may be used in a variety of applications such as membranes, either thermoplastic or thermoset, wire and cable jackets and the like. Plasticizers and other viscosity-reducing aids need not be used in conjunction with these resins.Type: GrantFiled: July 24, 1987Date of Patent: June 14, 1988Assignee: The Dow Chemical CompanyInventors: Keith E. Stephens, Andre J. Uzee
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Patent number: 4730035Abstract: Moist halogenated resins separated from an aqueous acid suspension of said resins are dried and stripped of residual acid with a heated inert drying gas. The resins are not washed to lower residual acid or treated with a base compound to neutralize residual acid before drying begins. Inert drying gases include nitrogen, helium, argon and the like. The dried resin has low residual acid and moisture levels. It is white and free of visually detectable areas of discoloration. It also has high thermal stability, particularly when admixed with minor amounts of a thermal stabilizer such as calcium stearate.Type: GrantFiled: September 4, 1986Date of Patent: March 8, 1988Assignee: The Dow Chemical CompanyInventors: Frank E. Mark, Charles B. Carpenter, James B. Akers, Jr.
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Patent number: 4727175Abstract: This invention relates to R.sub.1, R.sub.2 -hydroxyphenoxycyclotriphosphazenes and to a process for their preparation. R.sub.1 is a phenoxy-, halophenoxy- or an isopropoxy- group while R.sub.2 is a hydroxyphenoxy- or a bis-phenoxy A group. The process comprises reacting R.sub.1 -chlorocyclotriphosphazene with an R.sub.2 salt. The reaction takes place in the presence of an inert organic solvent and at a temperature within the range of from about 20.degree. C. to about 150.degree. C.Type: GrantFiled: September 29, 1986Date of Patent: February 23, 1988Assignee: The Dow Chemical CompanyInventor: Massimo D. Bezoari
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Patent number: 4727176Abstract: This invention relates to R.sub.1, i.e., phenoxy-, halophenoxy- and isopropoxy- hydroxymethylphenoxycyclotriphosphazenes and to a process for their preparation. The process comprises reacting R.sub.1 -chlorocyclotriphosphazene with a salt of hydroxymethylphenoxide. The reaction takes place in the presence of an inert organic solvent and at a temperature within the range of from about 20.degree. C. to about 150.degree. C. The invention also relates to R.sub.1 -hydroxymethylphenoxycyclotetraphosphazenes. Also disclosed is a process for preparing a mixture of R.sub.1 -hydroxymethylcyclotriphosphazene and R.sub.1 -hydroxymethylcyclotetraphosphazene by reacting a mixture of R.sub.1 -chlorocyclotriphosphazene and R.sub.1 -chlorocyclotetraphosphazene with a hydroxymethylphenoxide salt.Type: GrantFiled: September 29, 1986Date of Patent: February 23, 1988Assignee: The Dow Chemical CompanyInventor: Massimo D. Bezoari