Patents Represented by Attorney John Y. Chen
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Patent number: 5160369Abstract: The present invention provides ballpoint pen ink compositions containing carbon black which are initially erasable and require little or no external pressure for ink delivery. The ink can be erased easily with a normal rubber eraser such as that found on pencils. The ink compositions of the present invention comprises: about 15% to about 40% of an aliphatic hydrocarbon, about 15% to about 40% of an aromatic hydrocarbon, about 1% to about 15% of a colorant, about 4% to about 40% of one or more of a preselected thermoplastic block copolymer, and about 5% to about 40% of a preselected parting agent.Type: GrantFiled: February 21, 1991Date of Patent: November 3, 1992Assignee: SRI Inc.Inventors: Dean B. Parkinson, Orton D. Bergren
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Patent number: 5028928Abstract: An inflatable target support system having a minimum radar cross section, a high mechanical strength, an ultra-high rigidity and a high load bearing capacity. The system comprises a thin, inflatable, stressed-skin membrane in the shape of a right cone which is sealed at its narrow end by a extremely rigid, plug and sealed at its wide end by a chamfer shaped base so as to provide exceptional rigidity to the system.Type: GrantFiled: June 26, 1990Date of Patent: July 2, 1991Inventors: Robert J. Vidmar, David G. Watters
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Patent number: 4943485Abstract: Protective coatings are applied to substrate metals by coating the metal surface, e.g. by dipping the substrate metal in a molten alloy of the coating metals, and then exposing the coating at an elevated temperature to an atmosphere containing a reactive gaseous species which forms a nitride, a carbide, a boride or a silicide. The coating material is a mixture of the metals M.sub.1 and M.sub.2, M.sub.1 being zirconium and/or titanium, which forms a stable nitride, carbide, boride or silicide under the prevailing conditions. The metal M.sub.2 does not form a stale nitride, carbide, boride or silicide. M.sub.2 serves to bond the carbide, etc. of M.sub.1 to the substrate metal. Mixtures of M.sub.1 and/or M.sub.2 metals may be employed. This method is much easier to carry out than prior methods and forms superior coatings. Eutectic alloys of M.sub.1 and M.sub.2 which melt substantially lower than the melting point of the substrate metal are preferred.Type: GrantFiled: July 18, 1989Date of Patent: July 24, 1990Assignee: S R I InternationalInventors: Ibrahim M. Allam, David J. Rowcliffe
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Patent number: 4935073Abstract: Protective coatings are applied to substrate metals by coating the metal surface, e.g. by dipping the substrate metal in a molten alloy of the coating metals, and then exposing the coating at an elevated temperature to an atmosphere containing a reactive gaseous species which forms an oxide, a nitride, a carbide, a boride or a silicide. The coating material is a mixture of the metals M.sub.1 and M.sub.2, M.sub.1 being zirconium and/or titanium, which forms a stable oxide, nitride, carbide, boride or silicide under the prevailing conditions. The metal M.sub.2 does not form a stable oxide, nitride, carbide, boride or silicide. M.sub.2 serves to bond the oxide, etc. of M.sub.1 to the substrate metal. Mixtures of M.sub.1 and/or M.sub.2 metals may be employed. This method is much easier to carry out than prior methods and forms superior coatings. Eutectic alloys of M.sub.1 and M.sub.2 which melt substantially lower than the melting point of the substrate metal are preferred.Type: GrantFiled: October 21, 1987Date of Patent: June 19, 1990Assignee: SRI InternationalInventors: Robert W. Bartlett, Paul J. Jorgensen, Ibrahim M. Allam, David J. Rowcliffe
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Patent number: 4913980Abstract: A method of protecting ferrous metal structures from oxidative attack in an aqueous, corrosive, oxidative environment by applying a thin, impervious coating of an oxide of titanium, zirconium, tantalum or niobium (or a mixture of two or more such oxides). The coating is applied as an alloy (preformed or form in situ) of the respective metal and a more noble metal such as nickel, cobalt, copper or iron and the alloy is preferably thermally oxidized under conditions to oxidize the titanium, zirconium and/or niobium without oxidizing the more noble metal, which serves to bind the oxide coating to the substrate. Alternatively the alloy may be applied, and then oxidized by the conditions of use.Type: GrantFiled: April 22, 1988Date of Patent: April 3, 1990Assignee: S R I InternationalInventors: David J. Rowcliffe, Ibrahim M. Allam, Paul J. Jorgensen
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Patent number: 4857116Abstract: Protective coatings are applied to substrate metals by coating the metal surface, e.g. by dipping the substrate metal in a molten alloy of the coating metals, and then exposing the coating at an elevated temperature to an atmosphere containing a reactive gaseous species which forms a nitride, a carbide, a boride or a silicide. The coating material is a mixture of the metals M.sub.1 and M.sub.2, M.sub.1 being zirconium and/or titanium, which forms a stable nitride, carbide, boride or silicide under the prevailing conditions. The metal M.sub.2 does not form a stable nitride, carbide, boride or silicide. M.sub.2 serves to bond the carbide, etc. of M.sub.1 to the substrate metal. Mixtures of M.sub.1 and/or M.sub.2 metals may be employed. This method is much easier to carry out than prior methods and forms superior coatings. Eutectic alloys of M.sub.1 and M.sub.2 which melt substantially lower than the melting point of the substrate metal are preferred.Type: GrantFiled: October 21, 1987Date of Patent: August 15, 1989Assignee: S R I InternationalInventors: Ibrahim M. Allam, David J. Rowcliffe
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Patent number: 4855132Abstract: Biodegradible polymers are provided which may contain a biologically active substance, e.g. a drug such as insulin, which is released over a period of time as the polymer erodes when in contact with a body fluid. The polymer contains an amine functionality whereby it erodes faster at low acid pH's than at higher acid pH's. As an example, the polymer may contain insulin and may contain or may have an encapsulating hydrogel containing glucose oxidase. As the blood sugar level of a diabetic person rises, e.g., after a meal, glucose diffuses into the polymer or hydrogel and is converted to gluconic acid which lowers the pH, and accelerates erosion and the release of insulin.Type: GrantFiled: July 1, 1988Date of Patent: August 8, 1989Assignee: S R I InternationalInventors: Jorge Heller, Donald W. H. Penhale, Steve Y. Ng
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Patent number: 4764364Abstract: Biodegradible polymers are provided which may contain a biologically active substance, e.g. a drug such as insulin, which is released over a period of time as the polymer erodes when in contact with a body fluid. The polymer contains an amine functionality whereby it erodes faster at low acid pH's than at higher acid pH's. As an example, the polymer may contain insulin and may contain or may have an encapsulating hydrogel containing glucose oxidase. As the blood sugar level of a diabetic person rises, e.g., afte a meal, glucose diffuses into the polymer or hydrogel and is converted to gluconic acid which lowers the pH, and accelerates erosion and the release of insulin.Type: GrantFiled: February 25, 1986Date of Patent: August 16, 1988Assignee: S R I InternationalInventors: Jorge Heller, Donald W. H. Penhale, Steve Y. Ng
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Patent number: 4715902Abstract: Process for applying a protective coating to a metal substrate which provides a thermal barrier and a barrier against oxidation of the substrate. The coating material is a mixture of (1) zirconium and/or hafnium and (2) a metal such as nickel which does not form a stable oxide at a high temperature in an atmosphere having a very low concentration of oxygen. The coating is subjected to such conditions to produce an outer oxide layer of metal zirconium and/or hafnium and an inner metal layer of the second metal alloyed with one or more components of the substrate. The oxide layer provides thermal and oxidation protection and the inner layer bonds the coating to the substrate.Type: GrantFiled: April 4, 1985Date of Patent: December 29, 1987Assignee: S R I InternationalInventors: Ibrahim M. Allam, David J. Rowcliffe
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Patent number: 4612383Abstract: Method of producing polysilazanes from precursors having Si-H, Si-N or Si-Si bonds in the presence of a catalyst effective to activate such bonds. The catalyst may be a metal complex, e.g. a carbonyl cluster, which is soluble in an organic solvent and is homogeneous or it may be a heterogeneous catalyst. Higher polymers, and/or less crosslinking and oligomer formation, and/or greater control over the product and/or faster reactions and/or greater yields result. The polymers are soluble in common organic solvents and/or are solids which can be shaped. The products can be pyrolyzed to silicon nitride or used without pyrolysis.Type: GrantFiled: April 26, 1985Date of Patent: September 16, 1986Assignee: S R I InternationalInventors: Richard M. Laine, Yigal Blum
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Patent number: 4533692Abstract: Novel compositions comprising a high concentration of one or more extended chain homopolymer, copolymer, or block polymer and certain polyphosphoric acids are prepared. Such compositions are optically anisotropic (liquid crystalline), capable of exhibiting excellent cohesive strength, and are especially suited to the production of high molecular weight ordered polymer fibers by dry-jet wet spinning. These liquid crystalline compositions are capable of being drawn through long air gap distances and spun at exceptionally high spin draw ratios. Fibers, films and other articles formed from these liquid crystalline compositions exhibit exceptionally high physical and heat resistant properties.Type: GrantFiled: September 17, 1982Date of Patent: August 6, 1985Assignee: SRI InternationalInventors: James F. Wolfe, Paul D. Sybert, Joanne R. Sybert
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Patent number: 4533724Abstract: Novel compositions comprising a high concentration of poly(2,6-benzothiazole) and certain polyphosphoric acids are prepared. Such compositions are optically anisotropic (liquid crystalline), capable of exhibiting excellent cohesive strength, and are especially suited to the production of high molecular weight ordered polymer fibers by dry-jet wet spinning. These liquid crystalline compositions are capable of being drawn through long air gap distances and spun at exceptionally high spin draw ratios. Fibers, films and other articles formed from these liquid crystalline compositions exhibit exceptionally high physical and heat resistant properties.Type: GrantFiled: September 17, 1982Date of Patent: August 6, 1985Assignee: SRI InternationalInventors: James F. Wolfe, Paul D. Sybert, Joanne R. Sybert, Blake Wilson
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Patent number: 4533693Abstract: Novel compositions comprising a high concentration of one or more extended chain homopolymer, copolymer, or block polymer and certain polyphosphoric acids are prepared. Such compositions are optically anisotropic (liquid crystalline), capable of exhibiting excellent cohesive strength, and are especially suited to the production of high molecular weight ordered polymer fibers by dry-jet wet spinning. These liquid crystalline compositions are capable of being drawn through long air gap distances and spun at exceptionally high spin draw ratios. Fibers, films and other articles formed from these liquid crystalline compositions exhibit exceptionally high physical and heat resistant properties.Type: GrantFiled: September 15, 1983Date of Patent: August 6, 1985Assignee: SRI InternationalInventors: James F. Wolfe, Paul D. Sybert, Joanne R. Sybert