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).

  • Patent number: 5462536
    Abstract: 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: Grant
    Filed: July 14, 1993
    Date of Patent: October 31, 1995
    Assignee: Hampshire Chemical Corp.
    Inventors: James A. Braatz, Clifton L. Kehr, Timothy G. Grasel, William S. Letter
  • Patent number: 5296518
    Abstract: 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: Grant
    Filed: December 18, 1991
    Date of Patent: March 22, 1994
    Assignee: Hampshire Chemical Corp.
    Inventors: Timothy G. Grasel, Clifford A. Ferrin, James L. Guthrie, Clifton L. Kehr
  • Patent number: 5270044
    Abstract: 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: Grant
    Filed: September 24, 1991
    Date of Patent: December 14, 1993
    Assignee: Hampshire Chemical Corp.
    Inventors: Glenn E. Fulmer, Narender P. Luthra, Clifton L. Kehr, Darwin S. Bull, James L. Guthrie
  • Patent number: 5266323
    Abstract: 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: Grant
    Filed: May 24, 1991
    Date of Patent: November 30, 1993
    Assignee: Hampshire Chemical Corp.
    Inventors: James L. Guthrie, Narendar P. Luthra, Clifton L. Kehr, Darwin S. Bull
  • Patent number: 5175229
    Abstract: 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: Grant
    Filed: July 3, 1991
    Date of Patent: December 29, 1992
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: James A. Braatz, Clifton L. Kehr
  • Patent number: 5169720
    Abstract: 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: Grant
    Filed: March 6, 1991
    Date of Patent: December 8, 1992
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: James A. Braatz, Aaron H. Heifetz, Clifton L. Kehr, Richard A. Wolfe
  • Patent number: 5075427
    Abstract: 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: Grant
    Filed: November 19, 1990
    Date of Patent: December 24, 1991
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Uan G. Kang, Joseph W. Raksis, Clifton L. Kehr, Clifford A. Ferrin, Jr.
  • Patent number: 5039458
    Abstract: 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: Grant
    Filed: November 7, 1989
    Date of Patent: August 13, 1991
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: James A. Braatz, Clifton L. Kehr
  • Patent number: 4886866
    Abstract: 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: Grant
    Filed: February 16, 1989
    Date of Patent: December 12, 1989
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: James A. Braatz, Clifton L. Kehr
  • Patent number: 4510097
    Abstract: 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: Grant
    Filed: November 20, 1978
    Date of Patent: April 9, 1985
    Assignee: W. R. Grace & Co.
    Inventors: Clifton L. Kehr, Walter R. Wszolek, Nelson S. Marans
  • Patent number: 4439553
    Abstract: 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: Grant
    Filed: January 17, 1983
    Date of Patent: March 27, 1984
    Assignee: W. R. Grace & Co.
    Inventors: James L. Guthrie, Clifton L. Kehr
  • Patent number: 4403083
    Abstract: 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: Grant
    Filed: August 31, 1982
    Date of Patent: September 6, 1983
    Assignee: W. R. Grace & Co.
    Inventors: Nelson S. Marans, Clifton L. Kehr
  • Patent number: 4211847
    Abstract: 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: Grant
    Filed: November 20, 1978
    Date of Patent: July 8, 1980
    Assignee: W. R. Grace & Co.
    Inventors: Clifton L. Kehr, Louis L. Wood, James L. Guthrie
  • Patent number: 4201846
    Abstract: 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: Grant
    Filed: November 24, 1978
    Date of Patent: May 6, 1980
    Assignee: W. R. Grace & Co.
    Inventors: Clifton L. Kehr, Louis L. Wood, Nelson S. Marans, Glenn E. Fulmer
  • Patent number: 4165411
    Abstract: 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: Grant
    Filed: September 20, 1977
    Date of Patent: August 21, 1979
    Assignee: W. R. Grace & Co.
    Inventors: Nelson S. Marans, Clifton L. Kehr, Robert M. Murch
  • Patent number: 4129694
    Abstract: 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: Grant
    Filed: April 7, 1976
    Date of Patent: December 12, 1978
    Assignee: W. R. Grace & Co.
    Inventors: Joseph A. Cogliano, Clifton L. Kehr
  • Patent number: 4008341
    Abstract: 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: Grant
    Filed: January 10, 1975
    Date of Patent: February 15, 1977
    Assignee: W. R. Grace & Co.
    Inventor: Clifton L. Kehr
  • Patent number: 3959191
    Abstract: 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: Grant
    Filed: December 30, 1974
    Date of Patent: May 25, 1976
    Assignee: W. R. Grace & Co.
    Inventors: Clifton L. Kehr, Nelson S. Marans
  • Patent number: 3931287
    Abstract: 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: Grant
    Filed: August 22, 1973
    Date of Patent: January 6, 1976
    Assignee: W. R. Grace & Co.
    Inventors: Clifton L. Kehr, Walter R. Wszolek