Patents by Inventor Ray F. Stewart
Ray F. Stewart has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20110048314Abstract: Devices are described that include a component comprised of a material having a structure of R1—C(O)—NX—R2, wherein each of R1 and R2 is independently a saturated alkyl having between 7-22 carbon atoms or an aryl, X is H or C(O)—Y, Y together with R1 forms a ring. The material is characterized by a single, sharp melting point, thus making it suitable for use, for example, in thermo-mechanical actuating devices or in temperature-indicating devices. Also described are compositions comprising two or more materials each having a structure of Rn1—C(O)—NH—Rn2 wherein, n is an identifying integer corresponding to a material in the composition; wherein for each material n in the composition, Rn1 and Rn2 are a saturated alkyl having between 7-22 carbon atoms, wherein for each material n Rn1 and Rn2 differ by one carbon atom, arid wherein the number of carbon atoms in Rn2 of each material n differs by four or less.Type: ApplicationFiled: November 2, 2010Publication date: March 3, 2011Inventor: Ray F. Stewart
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Patent number: 7875207Abstract: Devices are described that include a component comprised of a material having a structure of R1—C(O)—NX—R2, wherein each of R1 and R2 is independently a saturated alkyl having between 7-22 carbon atoms or an aryl, X is H or C(O)—Y, Y together with R1 forms a ring. The material is characterized by a single, sharp melting point, thus making it suitable for use, for example, in thermomechanical actuating devices or in temperature-indicating devices. Also described are compositions comprising two or more materials each having a structure of Rn1—C(O)—NH—R2 wherein, n is an identifying integer corresponding to a material in the composition; wherein for each material n in the composition, Rn1 and Rn2 are a saturated alkyl having between 7-22 carbon atoms, wherein for each material n Rn1 and Rn2 differ by one carbon atom, and wherein the number of carbon atoms in Rn2 of each material n differs by four or less.Type: GrantFiled: December 23, 2005Date of Patent: January 25, 2011Assignee: Bay Materials, LLCInventor: Ray F. Stewart
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Patent number: 7794657Abstract: A device is disclosed which is a highly sensitive and selective sensor. The device is comprised of a sensor material secured into a fixed position on substrate, a deformable arm and a signaling component which creates a detectable signal in response to movement of the arm. The sensitivity of the device is enhanced by using a sensor material which undergoes a dramatic change in volume which may be accompanied by a phase change in response contact with a target such a molecule of interest. The selectivity of the device is enhanced by incorporating highly specific binding receptors (e.g. antibodies) into the sensor material which receptors bind to specific targets (e.g. peptide epitopes). The binding of the target molecule to the receptor causes the sensor material to change dramatically in volume thereby moving the arm causing the signaling component (e.g. a piezoresistor) to create a detectable signal (e.g. change in resistance) thereby indicating the present of the target.Type: GrantFiled: May 28, 2004Date of Patent: September 14, 2010Assignee: Cantimer, Inc.Inventor: Ray F. Stewart
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Publication number: 20090306327Abstract: A method of improving the mechanical properties of polymers is described. The method involves heat treating the polymer at a temperature below the glass transition temperature in a wet or in a dry environment. Polymer articles capable of moisture uptake in humid environments, as well as polymer articles less susceptible to moisture uptake, have improved mechanical properties, particularly improved stress relaxation behavior and set properties, when treated in accord with the heat treatment method.Type: ApplicationFiled: July 29, 2005Publication date: December 10, 2009Inventors: Ray F. Stewart, John G. Lahlouh
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Publication number: 20090217864Abstract: A thermally sensitive device having a thermochromic indicating member is described. The device is prepared from a thermally conductive material and has at one end an indicating member that is formed from a thermochromic material.Type: ApplicationFiled: March 22, 2006Publication date: September 3, 2009Inventors: Ray F. Stewart, Kathryn Morton
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Publication number: 20090108230Abstract: Devices are described that include a component comprised of a material having a structure of R1—C(O)—NX—R2, wherein each of R1 and R2 is independently a saturated alkyl having between 7-22 carbon atoms or an aryl, X is H or C(O)—Y, Y together with R1 forms a ring. The material is characterized by a single, sharp melting point, thus making it suitable for use, for example, in thermomechanical actuating devices or in temperature-indicating devices. Also described are compositions comprising two or more materials each having a structure of Rn1—C(O)—NH—R2 wherein, n is an identifying integer corresponding to a material in the composition; wherein for each material n in the composition, Rn1 and Rn2 are a saturated alkyl having between 7-22 carbon atoms, wherein for each material n Rn1 and Rn2 differ by one carbon atom, and wherein the number of carbon atoms in Rn2 of each material ndiffers by four or less.Type: ApplicationFiled: December 23, 2005Publication date: April 30, 2009Inventor: Ray F. Stewart
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Publication number: 20090092519Abstract: The subject matter described herein relates to thermoresponsive switching materials that undergo a thermal transition over a narrow temperature range and to devices, such as actuators, indicators, and sensors, prepared from such compositionsType: ApplicationFiled: October 1, 2008Publication date: April 9, 2009Applicant: Bay Materials, LLCInventors: Ray F. Stewart, Debra L. Dunson
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Patent number: 7182951Abstract: A new vigor test is used to select seeds which, after appropriate polymeric coating, will perform well under adverse planting and growing conditions. For example, suitably coated hybrid corn seeds can be planted earlier than seeds now available, while still obtaining comparable or better yields. Particularly good results are obtained when seeds are coated with compositions comprising a side chain crystalline polymer and an amorphous polymer.Type: GrantFiled: January 29, 2003Date of Patent: February 27, 2007Assignee: Landec CorporationInventors: Natarajan Balachander, Julian E. Schafer, Ray F. Stewart, David D. Taft
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Patent number: 7175832Abstract: Aqueous dispersions of crystalline polymers based on hydrophobic monomers, preferably on a mixture of hydrophobic and hydrophilic monomers which contains a crosslinking monomer, particularly side chain crystalline (SCC) polymers. The dispersions are useful for providing coatings on substrates, particularly on seeds (whose dormancy is thus extended) and on fibrous substrates, particularly human hair (which thus becomes heat-settable).Type: GrantFiled: December 17, 2002Date of Patent: February 13, 2007Assignee: Landec CorporationInventors: Ray F. Stewart, Natarajan Balachander, Steven P. Bitler, Loc Phan, Valentine Y. Yoon
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Patent number: 7169451Abstract: Novel gas-permeable membranes which are particularly useful in the packaging of fresh cut fruit and vegetables, and other respiring biological materials. The membranes have an O2 permeability of at least 775,000 ml/m2.atm.24 hrs, a P10 ratio of at least 1.3, and a ratio of CO2 permeability to O2 permeability (R) of at least 1.5, and are made by forming thin polymeric coatings on microporous polymeric films. Preferred coating polymers are side chain crystalline polymers. Preferred microporous films contain inorganic fillers, particularly such films based on ultrahigh molecular weight polyethylene or polypropylene. FIG. 1 illustrates how O2 permeability and R ratio vary for different coating polymers and microporous films.Type: GrantFiled: October 12, 2001Date of Patent: January 30, 2007Assignee: Landec CorporationInventors: Raymond Clarke, Ray F. Stewart, Valentine Y. Yoon, Donald A. Schultz, Bradley McClary
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Patent number: 6831116Abstract: Novel modifying agents contain a sharply-melting crystalline polymer ingredient, preferably a side chain crystalline (SCC) ingredient, and an active chemical ingredient. Such modifying agents, especially when in the form of particles, can be placed in contact with a matrix, will not modify the matrix below the crystalline melting point Tp, but will rapidly modify the matrix above Tp. The active chemical ingredient can react with the matrix, catalyze a reaction of the matrix, or inhibit a reaction of the matrix. Particularly useful compositions are polymer precursors which are storage-stable at low temperatures but which are rapidly converted to crosslinked resins when heated to temperatures above Tp, optionally in the presence of light.Type: GrantFiled: December 8, 2000Date of Patent: December 14, 2004Assignee: Landec CorporationInventors: Steven P. Bitler, Ray F. Stewart, Mark A. Wanthal, David A. Kamp, Paul A. Meyers, David D. Taft, Donald A. Schultz
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Publication number: 20030147946Abstract: Aqueous dispersions of crystalline polymers based on hydrophobic monomers, preferably on a mixture of hydrophobic and hydrophilic monomers which contains a crosslinking monomer, particularly side chain crystalline (SCC) polymers. The dispersions are useful for providing coatings on substrates, particularly on seeds (whose dormancy is thus extended) and on fibrous substrates, particularly human hair (which thus becomes heat-settable).Type: ApplicationFiled: December 17, 2002Publication date: August 7, 2003Inventors: Ray F. Stewart, Natarajan Balachander, Steven P. Bitler, Loc Phan, Valentine Y. Yoon
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Patent number: 6540984Abstract: Aqueous dispersions of crystalline polymers based on hydrophobic monomers, preferably on a mixture of hydrophobic and hydrophilic monomers which contains a crosslinking monomer, particularly side chain crystalline (SCC) polymers. The dispersions are useful for providing coatings on substrates, particularly on seeds (whose dormancy is thus extended) and on fibrous substrates, particularly human hair (which thus becomes heat-settable).Type: GrantFiled: January 18, 2001Date of Patent: April 1, 2003Assignee: Landec CorporationInventors: Ray F. Stewart, Natarajan Balachander, Steven P. Bitler, Loc Phan, Valentine Y. Yoon
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Patent number: 6492462Abstract: The rheological properties of a crosslinkable resin system are modified by the presence of a side chain crystalline (SCC) polymer (or a similar crystalline polymer which melts over a narrow temperature range). The polymer dissolves in the curable system at temperatures above the melting point of the crystalline polymer (Tp), but when the system is then cooled to a temperature below Tp, at least partially forms a separate phase in the curable system. Below Tp, this separate phase substantially increases the viscosity of the curable system (i.e. makes it thicker than the same system without the crystalline polymer). This is particularly valuable for sheet molding composites (SMCs) in which the increase in viscosity makes the composites less tacky, and for dry film resists (DFRs). Above Tp, the curable system containing the dissolved crystalline polymer has a viscosity which is substantially less than its viscosity below Tp.Type: GrantFiled: December 19, 2000Date of Patent: December 10, 2002Assignee: Landec CorporationInventors: Steven P. Bitler, David D. Taft, Ray F. Stewart
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Publication number: 20020054969Abstract: Novel gas-permeable membranes which are particularly useful in the packaging of fresh cut fruit and vegetables, and other respiring biological materials. The membranes have an O2 permeability of at least 775,000 ml/m2.atm.24 hrs, a P10 ratio of at least 1.3, and a ratio of CO2 permeability to O2 permeability (R) of at least 1.5, and are made by forming thin polymeric coatings on microporous polymeric films. Preferred coating polymers are side chain crystalline polymers. Preferred microporous films contain inorganic fillers, particularly such films based on ultrahigh molecular weight polyethylene or polypropylene. FIG. 1 illustrates how O2 permeability and R ratio vary for different coating polymers and microporous films.Type: ApplicationFiled: October 12, 2001Publication date: May 9, 2002Inventors: Raymond Clarke, Ray F. Stewart, Valentine Y. Yoon, Donald A. Schultz, Bradley McClary
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Patent number: 6376032Abstract: Novel gas-permeable membranes which are particularly useful in the packaging of fresh cut fruit and vegetables, and other respiring biological materials. The membranes have an O2 permeability of at least 775,000 ml/m2.atm.24 hrs, a P10 ratio of at least 1.3, and a ratio of CO2 permeability to O2 permeability (R) of at least 1.5, and are made by forming thin polymeric coatings on microporous polymeric films. Preferred coating polymers are side chain crystalline polymers. Preferred microporous films contain inorganic fillers, particularly such films based on ultrahigh molecular weight polyetheylene or polypropylene. FIG. 1 illustrates how O2 permeability an R ratio vary for different coating polymers and microporous films.Type: GrantFiled: December 5, 1996Date of Patent: April 23, 2002Assignee: Landec CorporationInventors: Raymond Clarke, Ray F. Stewart, Valentine Y. Yoon, Donald A. Schultz, Bradley McClary
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Publication number: 20010014310Abstract: Aqueous dispersions of crystalline polymers based on hydrophobic monomers, preferably on a mixture of hydrophobic and hydrophilic monomers which contains a crosslinking monomer, particularly side chain crystalline (SCC) polymers. The dispersions are useful for providing coatings on substrates, particularly on seeds (whose dormancy is thus extended) and on fibrous substrates, particularly human hair (which thus becomes heat-settable).Type: ApplicationFiled: January 18, 2001Publication date: August 16, 2001Inventors: Ray F. Stewart, Natarajan Balachander, Steven P. Bitler, Loc Phan, Valentine Y. Yoon
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Publication number: 20010007881Abstract: Novel modifying agents contain a sharply-melting crystalline polymer ingredient, preferably a side chain crystalline (SCC) ingredient, and an active chemical ingredient. Such modifying agents, especially when in the form of particles, can be placed in contact with a matrix, will not modify the matrix below the crystalline melting point Tp, but will rapidly modify the matrix above Tp. The active chemical ingredient can react with the matrix, catalyze a reaction of the matrix, or inhibit a reaction of the matrix. Particularly useful compositions are polymer precursors which are storage-stable at low temperatures but which are rapidly converted to crosslinked resins when heated to temperatures above Tp, optionally in the presence of light.Type: ApplicationFiled: December 8, 2000Publication date: July 12, 2001Inventors: Steven P. Bitler, Ray F. Stewart, Mark A. Wanthal, David A. Kamp, Paul A. Meyers, David D. Taft, Donald A. Schultz
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Patent number: 6255367Abstract: Novel modifying agents contain a sharply-melting crystalline polymer ingredient, preferably a side chain crystalline (SCC) ingredient, and an active chemical ingredient. Such modifying agents, especially when in the form of particles, can be placed in contact with a matrix, will not modify the mix below the crystalline melting point Tp, but will rapidly modify the matrix above Tp. The active chemical ingredient can react with the matrix, catalyze a reaction of the matrix, or inhibit a reaction of the matrix. Particularly useful compositions are polymer precursors which are storage-stable at low temperatures but which are rapidly converted to crosslinked resins when heated to temperatures above Tp, optionally in the presence of light.Type: GrantFiled: December 16, 1998Date of Patent: July 3, 2001Assignee: Landec CorporationInventors: Steven P. Bitler, Ray F. Stewart
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Publication number: 20010002414Abstract: The rheological properties of a crosslinkable resin system can be substantially improved by the presence of an SCC polymer (or a similar crystalline polymer which melts over a narrow temperature range). The polymer dissolves in the curable system at temperatures above the melting point of the crystalline polymer (Tp), but when the system is then cooled to a temperature below Tp, at least partially forms a separate phase in the curable system. Below Tp, this separate phase substantially increases the viscosity of the curable system (i.e. makes it thicker than the same system without the crystalline polymer). This is particularly valuable for sheet molding composites (SMCs), in which the increase in viscosity makes the composites less tacky, and for dry film resists (DFRs). Above Tp, the curable system containing the dissolved crystalline polymer has a viscosity which is substantially less than its viscosity below Tp.Type: ApplicationFiled: December 19, 2000Publication date: May 31, 2001Inventors: Steven P. Bitler, David D. Taft, Ray F. Stewart