Clifton L Kehr from Frederick, MD

Novel Urethane Polythiols
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US Patent:

39819043, Sep 21, 1976
Filed:

Jul 24, 1975
Appl. No.:

5/598912
Inventors:

James Leverette Guthrie - Ashton MD
Clifton Leroy Kehr - Silver Spring MD
Assignee:

W. R. Grace & Co. - New York NY
International Classification:

C07C10144
US Classification:

260471C
Abstract:

A urethane polythiol, which can be a dithiol, is prepared by reacting a hydroxypolythiol, which can be dithiol, with an isocyanate such as a phenyl isocyanate, toluene diisocyanate, and the like.

Novel Urethane Polythiols
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US Patent:

39844560, Oct 5, 1976
Filed:

Jul 24, 1975
Appl. No.:

5/598595
Inventors:

James Leverette Guthrie - Ashton MD
Clifton Leroy Kehr - Silver Spring MD
Assignee:

W. R. Grace & Co. - New York NY
International Classification:

C07C14426
US Classification:

260468E
Abstract:

A urethane polythiol, which can be a dithiol, is prepared by reacting a hydroxypolythiol, which can be a dithiol, with an isocyanate such as phenyl isocyanate, toluene diisocyanate, and the like.

Curable Liquid Polymer Compositions
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US Patent:

40083411, Feb 15, 1977
Filed:

Jan 10, 1975
Appl. No.:

5/540057
Inventors:

Clifton L. Kehr - Silver Spring MD
Assignee:

W. R. Grace & Co. - New York NY
International Classification:

B05D 306
US Classification:

427 44
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.

High Molecular Weight Aromatic Amine Scavengers And Method Of Use
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US Patent:

44395531, Mar 27, 1984
Filed:

Jan 17, 1983
Appl. No.:

6/458434
Inventors:

James L. Guthrie - Ashton MD
Clifton L. Kehr - Silver Spring MD
Assignee:

W. R. Grace & Co. - New York NY
International Classification:

C08G 1814
US Classification:

521159
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.

Method Of Making A Hydrophilic, Biocompatible, Protein Non-Adsorptive Contact Lens
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US Patent:

50394584, Aug 13, 1991
Filed:

Nov 7, 1989
Appl. No.:

7/432833
Inventors:

James A. Braatz - Rockville MD
Clifton L. Kehr - Silver Spring MD
Assignee:

W. R. Grace & Co.-Conn. - New York NY
International Classification:

B29D 1100
US Classification:

264 26
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.

Protein Non-Adsorptive Polyurea-Urethane Polymer Coated Devices
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US Patent:

51697203, Dec 8, 1992
Filed:

Mar 6, 1991
Appl. No.:

7/665498
Inventors:

James A. Braatz - Beltsville MD
Aaron H. Heifetz - Columbia MD
Clifton L. Kehr - Silver Spring MD
Richard A. Wolfe - Ellisville MO
Assignee:

W. R. Grace & Co.-Conn. - New York NY
International Classification:

B32B 2740
US Classification:

4284231
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.

Flame Retardant Urethane And Method
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US Patent:

41654110, Aug 21, 1979
Filed:

Sep 20, 1977
Appl. No.:

5/834927
Inventors:

Nelson S. Marans - Silver Spring MD
Clifton L. Kehr - Silver Spring MD
Robert M. Murch - Ashton MD
Assignee:

W. R. Grace & Co. - New York NY
International Classification:

C08K 552
C08K 553
C08K 551
US Classification:

521107
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.

Urethane Polythiols
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US Patent:

40454720, Aug 30, 1977
Filed:

Dec 15, 1975
Appl. No.:

5/640499
Inventors:

James Leverette Guthrie - Ashton MD
Clifton Leroy Kehr - Silver Spring MD
Assignee:

W. R. Grace & Co. - New York NY
International Classification:

C07C149437
US Classification:

260471C
Abstract:

The novel urethane polythiols of this invention are prepared by reacting: (a) a mono-, di-, or trihydric polythiol with a polymeric isocyanate; or (b) a di- or trihydric polythiol with a diisocyanate.

Clifton L Kehr