Patents by Inventor David Alan Czekai

David Alan Czekai 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: 5994041
    Abstract: An aqueous-based slurry comprising:a particulate solid substance comprising a weak acid functional group having effective pK.sub.a1 >1 and less than 1% by weight aqueous solubility at pH=pK.sub.a1 ;an aqueous continuous phase at pH<pK.sub.a1 +3;a buffering salt of a weak acid, where the weak acid associated with this buffering salt has pK.sub.a2 and wherepK.sub.a1 -2.ltoreq.pK.sub.a2 ;andwhere the incremental molar ionic strength in the continuous phase of said slurry resulting from said buffering salt is less than 0.04 mol/L is disclosed.
    Type: Grant
    Filed: February 6, 1998
    Date of Patent: November 30, 1999
    Assignee: Eastman Kodak Company
    Inventors: John Texter, Ravi Sharma, David Alan Czekai
  • Patent number: 5750321
    Abstract: A process for buffering concentrated aqueous slurries comprising the steps of:providing a particulate solid substance comprising a weak acid functional group, having effective pK.sub.a1 >1 and less than 1% by weight aqueous solubility at pH=pK.sub.a1 ;providing an aqueous solution consisting essentially of water or a mixture of water with water-miscible solvent, at pH less than the greater of 7 and pK.sub.a1 +2;providing a buffering salt of a weak acid, where the weak acid associated with this buffering salt has pK.sub.a2 and wherepK.sub.a1 -2.ltoreq.pK.sub.a2 ; andcombining said aqueous solution, said particulate solid substance, and said buffering salt to form a slurry;wherein said process is essentially devoid of any step comprising the addition of any weak acid, other than that arising from reaction between said buffering salt and said particulate solid substance, having greater than 2% by weight aqueous solubility at pH=pK.sub.a1 is disclosed.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: May 12, 1998
    Assignee: Eastman Kodak Company
    Inventors: John Texter, Ravi Sharma, David Alan Czekai
  • Patent number: 5723255
    Abstract: An aqueous solid particle dispersion of a thermal solvent, where said thermal solvent is a water-immiscible phenol derivative and has a melting point, T.sub.m, between 30.degree. C. and about 200.degree. C., wherein said dispersion contains a dispersing aid, and wherein the thermal solvent particles in said dispersion are essentially nanocrystalline is disclosed. Also disclosed is a process for forming a coating comprising the steps of:providing an aqueous solid particle dispersion of thermal solvent, where said thermal solvent is a water-immiscible phenol derivative and has a melting point, T.sub.m, between 30.degree. C. and about 200.degree. C., and where said dispersion contains a dispersing aid;combining said aqueous solid particle thermal solvent dispersion with a coating melt composition, where said coating melt composition is maintained at a temperature, T.sub.c, during the preparation and coating of said coating melt composition, and where T.sub.c <T.sub.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: March 3, 1998
    Assignee: Eastman Kodak Company
    Inventors: John Texter, David Alan Czekai
  • Patent number: 5679138
    Abstract: A process for making ink jet inks, comprising the steps of:(A) providing an organic pigment dispersion containing a pigment, a carrier for the pigment and a dispersant;(B) mixing the pigment dispersion with rigid milling media having an average particle size less than 100 .mu.m;(C) introducing the mixture of step (B) into a high speed mill;(D) milling the mixture from step (C) until a pigment particle size distribution is obtained wherein 90% by weight of the pigment particles have a size less than 100 nanometers (nm);(E) separating the milling media from the mixture milled in step (D); and(F) diluting the mixture from step (E) to obtain an ink jet ink having a pigment concentration suitable for ink jet printers.
    Type: Grant
    Filed: November 30, 1995
    Date of Patent: October 21, 1997
    Assignee: Eastman Kodak Company
    Inventors: John F. Bishop, David Alan Czekai
  • Patent number: 5662279
    Abstract: A method of preparing milled solid particles of a compound comprises the steps of forming a slurry of a liquid medium, the compound and rigid milling media in a milling chamber, contacting the compound with the milling media while in the chamber to reduce the particle size of the compound, and thereafter separating the compound from the milling media by vacuum filtration through a removable filter probe immersed in the slurry. In a preferred embodiment, the milling media is a polymeric resin having a mean particle size of less than 300 .mu.m. The method enables the use of fine milling media which provides extremely fine particles of the compound while avoiding problems, e.g., decrease yields due to separator screen plugging, associated with prior art processes.
    Type: Grant
    Filed: December 5, 1995
    Date of Patent: September 2, 1997
    Assignee: Eastman Kodak Company
    Inventors: David Alan Czekai, Larry Paul Seaman, Dennis Edward Smith