Patents by Inventor Dennis W. Karle

Dennis W. Karle 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: 5116685
    Abstract: Compositions for magnetic recording media comprising a nonmagnetic support and a magnetic layer adhered to the nonmagnetic support, wherein the magnetic layer comprises a ferromagnetic substance and a binder system, preferably the binder system comprises primarily a polyester polyurethane polymer and small percentage amounts of a low molecular weight polyol crosslinked with a multifunctional isocyanate. Methods of formation of the compositions are also described. Presence of the low molecular weight polyol is particularly important in attaining desired performance characteristics in wound pile stability, layer-to-layer adhesion, and durability.
    Type: Grant
    Filed: February 14, 1990
    Date of Patent: May 26, 1992
    Assignee: Memorex Telex, N.V.
    Inventors: Dennis W. Karle, Fred C. Chung, Frederic J. Sischka, II
  • Patent number: 4916021
    Abstract: A novel resinous binder composition is disclosed for a magnetic recording tape. Magnetic particles are dispersed within a resinous matrix having both a hard and soft component. The hard component is fabricated by exposing a resin capable of being cured by electron beam irradiation to set the radiation forming a semi-interpenetrating network with "soft" material.
    Type: Grant
    Filed: May 6, 1987
    Date of Patent: April 10, 1990
    Assignee: Memorex Telex N.V.
    Inventors: Dennis W. Karle, Zie A. Payne
  • Patent number: 4861655
    Abstract: A magnetic recording medium comprises a substrate coated with a magnetic layer comprising a magnetic powder and a binder comprising an urethane resin and a vinyl chloride maleic acid copolymer having no maleic acid component and at least no more than about 0.5 wt. %.
    Type: Grant
    Filed: September 8, 1986
    Date of Patent: August 29, 1989
    Assignee: Memorex Corporation
    Inventor: Dennis W. Karle
  • Patent number: 4686146
    Abstract: A novel resinous binder composition is disclosed for a magnetic recording tape or like media. Magnetic particles are dispersed within a resinous matrix having both a "hard" and a "soft" component. The "hard" component is fabricated by exposing a resin capable of being cured by electron beam irradiation.The magnetic recording media coating is very apt for use with harsh pigment like CrO.sub.2 particles and is adapted for frequent contact with a head, being adapted to exhibit good durability, abrasivity, etc. by virtue of using a lubricant system including a fluoro-silicone oil and a compatible fatty-acid-ester like butoxy ethyl stearate.
    Type: Grant
    Filed: February 18, 1986
    Date of Patent: August 11, 1987
    Assignee: Memorex Corporation
    Inventors: Dennis W. Karle, Zie A. Payne, Fred C. Chung, Ross P. Clark
  • Patent number: 4024067
    Abstract: Bis-benzoins of the formula ##STR1## wherein R is meta-phenylene or para-phenylene are prepared by first conting aldehydes of the formula ##STR2## with sodium bisulfite to form bisulfite addition products of the formula ##STR3## THEN CONTACTING THE BISULFITE ADDITION PRODUCTS WITH EITHER POTASSIUM CYANIDE OR SODIUM CYANIDE TO FORM CYANOHYDRINS OF THE FORMULA ##STR4## and finally contacting the cyanohydrins with benzaldehyde to form the bis-benzoins. The bis-benzoins can be oxidized to form the corresponding bis-benzils which are useful as starting materials for producing phenylated polyquinoxalines which in turn are useful as coatings for fibers, graphite precursors, films and laminating materials.
    Type: Grant
    Filed: January 7, 1976
    Date of Patent: May 17, 1977
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Kazimiera J. L. Paciorek, Reinhold H. Kratzer, Dennis W. Karle