Patents by Inventor John A. Van Velthuijsen

John A. Van Velthuijsen 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).

  • Method of preparing lacitol monohydrate and dihydrate
    Patent number: 5726303
    Abstract: The invention relates to the new product lactitol monohydrate and to a method for the production of crystalline lactitol. The crystalline lactitol monohydrate can be obtained bij seeding an aqueous lactitol solution of a special concentration under special conditions causing the lactitol monohydrate to crystallize and recovering the product. From the mother liquor a further amount of lactitol dihydrate can be recovered. Crystalline lactitol dihydrate can be obtained using different special conditions. Lactitolmonohydrate can further be obtained by mixing one part bij weight of an aqueous lactitol solution of a suited concentration with 1 tot 3 parts bij weight of methanol or ethanol and cooling the mixture to 15.degree. tot 25.degree. C.
    Type: Grant
    Filed: October 4, 1991
    Date of Patent: March 10, 1998
    Assignee: C.V. Chemie Combinatie Amsterdam C.C.A.
    Inventors: Christiaan F. Wijnman, John A. van Velthuijsen, Hendrik van den Berg
  • Oral hygiene preparation
    Patent number: 5531983
    Abstract: The invention relates to an oral hygienic preparation for combating tartar formation, which preparation comprises a physiologically acceptable medium, containing, incorporated therein, an effective amount of a substance which inhibits the formation of tartar. The substances to be used according to the invention are calcium lactate, calcium lactophosphate and the double salts of calcium lactate like the calcium sodium lactate double salt. Preferably calcium lactate is used as the tartar formation-inhibiting substance.
    Type: Grant
    Filed: September 13, 1994
    Date of Patent: July 2, 1996
    Assignee: Purac Biochem B.V.
    Inventor: John A. Van Velthuijsen