Patents by Inventor Clifton L. Kehr
Clifton L. Kehr 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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Patent number: 5462536Abstract: Controlled release membranes are prepared from polyureaurethane polymer derived from prepolymer units at least 75% of which are oxyethylene-based diols or polyols having essentially all of the hydroxyl groups capped with polyisocyanate are disclosed. The membranes are characterized by their biocompatibility and resistance to nonspecific protein adsorption and are particuarly useful for delivery of proteinaceous materials in drug-delivery systems, i.e., wound dressings. Also disclosed are novel biocompatible, protein-nonadsorptive hydrated polymers and the method of producing the same.Type: GrantFiled: July 14, 1993Date of Patent: October 31, 1995Assignee: Hampshire Chemical Corp.Inventors: James A. Braatz, Clifton L. Kehr, Timothy G. Grasel, William S. Letter
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Patent number: 5296518Abstract: Hydrophilic polyurethane urea foams which are made without toxic, leachable additives are disclosed. High molecular weight, isocyanate-terminated, ethylene oxide-rich prepolymers are used in place of surfactants to make the foams.Type: GrantFiled: December 18, 1991Date of Patent: March 22, 1994Assignee: Hampshire Chemical Corp.Inventors: Timothy G. Grasel, Clifford A. Ferrin, James L. Guthrie, Clifton L. Kehr
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Patent number: 5270044Abstract: A degradable article comprising a polyurethane polymer gel or foam whose polymer structure contains hydrolytically unstable ester linkages and various additives. The article can be constructed so that some of the additives are released from the article at a sustained rate. In a preferred embodiment the additives are sensory stimulants for marine or aquatic organisms and the article is used as bait for those organisms. Such sensory stimulants can include high molecular weight thickeners, to impart a slippery texture.Type: GrantFiled: September 24, 1991Date of Patent: December 14, 1993Assignee: Hampshire Chemical Corp.Inventors: Glenn E. Fulmer, Narender P. Luthra, Clifton L. Kehr, Darwin S. Bull, James L. Guthrie
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Patent number: 5266323Abstract: A degradable article comprising a polyurethane polymer gel or foam whose polymer structure contains hydrolytically unstable ester linkages and various additives. The article can be constructed so that some of the additives are released from the article at a sustained rate. In a preferred embodiment the additives are sensory stimulants for marine or aquatic organisms and the article is used as bait for those organisms.Type: GrantFiled: May 24, 1991Date of Patent: November 30, 1993Assignee: Hampshire Chemical Corp.Inventors: James L. Guthrie, Narendar P. Luthra, Clifton L. Kehr, Darwin S. Bull
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Patent number: 5175229Abstract: A class of hydrophilic prepolymers and hydrated polymer gels are disclosed which are characterized by their transparency, biocompatibility and resistance to nonspecific protein adsorption. At least 75%, preferably at least 90%, of the prepolymers are isocyanate-capped oxyethylene-based diols or polyols having molecular weight of about 7000-30,000. Essentially all of the hydroxyl groups of the diols or polyols are capped with polyisocyanate prior to formation of the hydrated polymer.Type: GrantFiled: July 3, 1991Date of Patent: December 29, 1992Assignee: W. R. Grace & Co.-Conn.Inventors: James A. Braatz, Clifton L. Kehr
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Patent number: 5169720Abstract: Polymer-coated medical and laboratory devices are disclosed which are characterized by their biocompatibility and resistance to nonspecific protein adsorption. The polyurea-polyurethane coatings of this invention are prepared from high molecular weight isocyanate end-capped prepolymers substantially or exclusively comprised of ethylene oxide units. At least 75%, preferably at least 90%, of the prepolymer units are oxyethylene-based diols or polyols having molecular weights of about 7000-30,000, with essentially all of the hydroxyl groups capped with polyisocyanate prior to formation of the hydrated polymer coating.Type: GrantFiled: March 6, 1991Date of Patent: December 8, 1992Assignee: W. R. Grace & Co.-Conn.Inventors: James A. Braatz, Aaron H. Heifetz, Clifton L. Kehr, Richard A. Wolfe
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Patent number: 5075427Abstract: The present invention is directed to aqueous compositions of organic diazo compounds which are capable of being readily handled in commercial applications and to the surface modification of polymeric substrates utilizing the subject diazo composition.Type: GrantFiled: November 19, 1990Date of Patent: December 24, 1991Assignee: W. R. Grace & Co.-Conn.Inventors: Uan G. Kang, Joseph W. Raksis, Clifton L. Kehr, Clifford A. Ferrin, Jr.
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Patent number: 5039458Abstract: A method of preparing a hydrophilic, biocompatible contact lens characterized by a surface which resists nonspecific protein adsorption. The method involves forming a prepolymer, at least 75% of which are oxyethylene-based diols and polyols having molecular weights of about 7000 to about 30,000. The prepolymer is subsequently gelled and hydrated to produce a hydrated polyurea-polyurethane polymer gel. The hydrated polymer gel is used to obtain a contact lens which resists nonspecific protein adsorption. Preferably, the contact lens are prepared by molding the prepolymer into a contact lens mold, prior to polymerization, to achieve the desired lens shape.Type: GrantFiled: November 7, 1989Date of Patent: August 13, 1991Assignee: W. R. Grace & Co.-Conn.Inventors: James A. Braatz, Clifton L. Kehr
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Patent number: 4886866Abstract: Hydrophilic polymeric soft contact lenses which are characterized by their biocompatibility and resistance to nonspecific protein adsorption. At least 75%, preferably at least 80%, of the prepolymers from which the lenses are prepared are isocyanate-capped oxyethylene-based diols or polyols having molecular weight of about 7000-30,000. Essentially all of the hydroxyl groups of the diols or polyols are capped with polyisocyanate prior to formation of the hydrated polymer of which the contact lenses are made.Type: GrantFiled: February 16, 1989Date of Patent: December 12, 1989Assignee: W. R. Grace & Co.-Conn.Inventors: James A. Braatz, Clifton L. Kehr
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Patent number: 4510097Abstract: This invention relates to novel hindered cycloaliphatic monoisocyanates of the general formula: ##STR1## wherein R.sub.1 -R.sub.7 are members of the group consisting of H, alkyl, cycloalkyl, aryl, alkaryl, aralkyl or mixtures thereof wherein the alkyl groups contain 1-18 carbon atoms, the cycloalkyl groups contain 4-8 carbon atoms and the aryl groups contain 6-14 carbon atoms with the proviso that where R.sub.3 is a group member other than H, R.sub.1, R.sub.2, R.sub.4 and R.sub.5 can be H and with the further proviso that where R.sub.3 is H at least two of R.sub.1, R.sub.2, R.sub.4 and R.sub.5 are group members other than H and x is 1 to 7. Other novel dihindered intermediate compositions include aliphatic monoamines.Type: GrantFiled: November 20, 1978Date of Patent: April 9, 1985Assignee: W. R. Grace & Co.Inventors: Clifton L. Kehr, Walter R. Wszolek, Nelson S. Marans
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Patent number: 4439553Abstract: This invention relates to hydrophilic, urethane-forming compositions and a method of forming polyurethanes having low residual, potentially carcinogenic, aromatic amines by adding scavengers comprising polyols end-capped with aliphatic polyisocyanates.Type: GrantFiled: January 17, 1983Date of Patent: March 27, 1984Assignee: W. R. Grace & Co.Inventors: James L. Guthrie, Clifton L. Kehr
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Patent number: 4403083Abstract: This invention relates to novel hydrophilic, crosslinked, polyurea-urethane, solid, discrete particles formed by adding in droplet form a hydrophilic prepolymer comprising an isocyanate-capped polyol or mixtures thereof wherein said polyol or mixture of polyols has a reaction functionality greater than two, the total of said polyol present having an ethylene oxide content of at least 40 weight percent, before capping to a large excess of a stirred aqueous reactant. The resultant solid particles can be molded into various shapes as desired or used for coating or adhesive applications.Type: GrantFiled: August 31, 1982Date of Patent: September 6, 1983Assignee: W. R. Grace & Co.Inventors: Nelson S. Marans, Clifton L. Kehr
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Patent number: 4211847Abstract: This invention relates to urethane forming compositions and a method of forming polyurethanes having low residual potentially carcinogenic aromatic amines by adding scavengers from the group comprising cyclohexyl monoisothiocyanate and hindered aliphatic monoisocyanates of the general formula: ##STR1## wherein R.sub.1 - R.sub.7 are H, alkyl, cycloalkyl, aryl, alkaryl, aralkyl or mixtures thereof and x is 1 to 7.Type: GrantFiled: November 20, 1978Date of Patent: July 8, 1980Assignee: W. R. Grace & Co.Inventors: Clifton L. Kehr, Louis L. Wood, James L. Guthrie
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Patent number: 4201846Abstract: The invention disclosed relates to hydrophilic polyurethane foam which exhibits improved tensile and tear properties and reduced shrinkage upon drying as a result of incorporation of substantially hydrophilic reinforcing fibers formed from homopolymers and copolymers of polyvinyl alcohol. The reinforced foams also exhibit reduced swelling upon contact with water.Type: GrantFiled: November 24, 1978Date of Patent: May 6, 1980Assignee: W. R. Grace & Co.Inventors: Clifton L. Kehr, Louis L. Wood, Nelson S. Marans, Glenn E. Fulmer
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Patent number: 4165411Abstract: The invention disclosed relates to a new polyurethane composition having improved flame retardance and to a method for preparing same. The present composition includes a hydrophilic polyurethane having alumina hydrate and a phosphorus containing compound disposed therein.Type: GrantFiled: September 20, 1977Date of Patent: August 21, 1979Assignee: W. R. Grace & Co.Inventors: Nelson S. Marans, Clifton L. Kehr, Robert M. Murch
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Patent number: 4129694Abstract: The invention disclosed relates to a new fabric softener foam having improved utility for softening textile fabrics in either a standard or automatic clothes dryer as well as in an automatic washer.Type: GrantFiled: April 7, 1976Date of Patent: December 12, 1978Assignee: W. R. Grace & Co.Inventors: Joseph A. Cogliano, Clifton L. Kehr
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Patent number: 4008341Abstract: This invention relates to a new curable composition which includes a liquid unsaturated component having at least two vinyl addition polymerizable groupings per average molecule and a polythiol component having a multiplicity of --SH functional groups per average molecule which cures to a solid polythioether in the presence of a free radical generator. When the free radical generator is actinic radiation, e.g. U. V. light, a photocuring rate accelerator, e.g. benzophenone is added to the composition. The cured product can be used as a coating, sealant, adhesive or molded article.Type: GrantFiled: January 10, 1975Date of Patent: February 15, 1977Assignee: W. R. Grace & Co.Inventor: Clifton L. Kehr
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Patent number: 3959191Abstract: The invention disclosed is for new improved hydrophobic polyurethane foams prepared by reacting a hydrophobic polyisocyanate reactant with large amounts of an aqueous reactant in the presence of an emulsifying agent. The resultant foams may be characterized with a broad spectrum of improved properties including load-bearing characteristics, hydrophobic properties, textural characteristics and the like.Type: GrantFiled: December 30, 1974Date of Patent: May 25, 1976Assignee: W. R. Grace & Co.Inventors: Clifton L. Kehr, Nelson S. Marans
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Patent number: 3931287Abstract: The invention disclosed is for a new and novel class of liquid polyene compositions formed of a molecule containing at least two unsaturated carbon-to-carbon bonds disposed at terminal positions on a main chain backbone of the molecule. The molecule includes unsaturated carbon-to-carbon bonds connected by a divalent chemically compatible derivative to a stable, organic, polyvalent, and polymeric member free of reactive carbon-to-carbon unsaturation and free of highly water-sensitive members. The new class of liquid polyene compositions which have a molecular weight in the range 300 to 20,000, and a viscosity in the range from essentially 0 to 20 million centipoises at 70.degree.C., may usefully form a component of a system which upon curing in the presence of a free radical generator and a polythiol, forms odorless, solid, elastomeric products. The cured products may be used as sealants, coatings, adhesives and molded articles.Type: GrantFiled: August 22, 1973Date of Patent: January 6, 1976Assignee: W. R. Grace & Co.Inventors: Clifton L. Kehr, Walter R. Wszolek