Patents by Inventor John E. Castle

John E. Castle 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: 5061792
    Abstract: Chitosan is converted to dry, free-flowing, water-soluble chitosan salts by heterogeneous reaction between particulate chitosan suspended in about 5 to about 50 parts by weight of a C.sub.1 to C.sub.3 monohydric alcohol containing an amount of water sufficient to raise the dielectric constant of the alcohol to at least about 30 and not more than about 40. Operable acids are slected from defined aliphatic and aromatic carboxylic, aromatic sulphonic, and inorganic acids having a first hydrogen pKa in water at room temperature of less than about 5.
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: October 29, 1991
    Assignee: University of Delaware
    Inventors: Charles J. Albisetti, John E. Castle
  • Patent number: 4931551
    Abstract: Ground chitin is rendered dispersible in aqueous medium to form stable dispersions on mild shearing, by pretreating the chitin with an aqueous oxidizing bleach solution. the dispersions, and paper-like structures prepared from them by papermaking techniques, are useful for treating and binding wounds.Operable bleaches include peroxygen bleaches and labile halogen bleaches. Peroxygen bleaches include hydrogen and alkali metal peroxide, alkaline earth and alkali metal perborate, percarbonate, peroxymonosulfate, and bromate. The labile halogen bleaches include alkali metal and alkaline earth hypohalites, and dihalo-s-triazinetriones.
    Type: Grant
    Filed: July 5, 1988
    Date of Patent: June 5, 1990
    Assignee: University of Delaware
    Inventors: Charles J. Albisetti, John E. Castle
  • Patent number: 4532321
    Abstract: A free amino microcrystalline chitin preferably in solid form is obtained. The process may involve the following steps of (1) treating particulate chitin at elevated temperature with phosphoric acid diluted with a lower aliphatic alcohol, (2) treating the resulting chitin with an alkali, (3) washing the chitin to remove the alkali from the chitin emulsion, (4) subjecting the chitin during at least one of the preceding steps to high speed shearing action to convert the processed chitin to the microcrystalline form, and (5) subjecting the resulting microcrystalline chitin emulsion from step 3 to the cycle of freezing and thawing, thereby separating the chitin as a solid from the liquid of the emulsion.
    Type: Grant
    Filed: June 14, 1982
    Date of Patent: July 30, 1985
    Assignee: University of Delaware
    Inventors: John E. Castle, Jeffrey R. Deschamps