Patents by Inventor Bernd Schonfeld

Bernd Schonfeld 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).

  • Process for the preparation of precipitated silica
    Patent number: 4738839
    Abstract: Crystalline precipitated silica is produced by hydrolyzing silicon tetrachloride in the presence of fluoride ions at a temperature of up to 60.degree. C.
    Type: Grant
    Filed: November 19, 1986
    Date of Patent: April 19, 1988
    Inventor: Bernd Schonfeld
  • Chlorofluoroferrate(II,III), a process for its manufacture, its use and a grinding wheel containing chlorofluoroferrate(II,III)
    Patent number: 4370148
    Abstract: Chlorofluoroferrates(II,III) are manufactured by fusing alkali metal halides or ammonium halides with an iron(III) halide and metallic iron. The starting materials used are, in particular, (a) an alkali metal chloride or ammonium chloride, (b) an alkali metal fluoride or ammonium fluoride, (c) anhydrous iron(III) chloride and (d) iron powder. The reaction is carried out a temperature of 300.degree. to 900.degree. C. The chlorofluoroferrates, which have a markedly lower hygroscopicity compared with customary chloroferrates, are particularly suitable for use as active fillers for grinding wheels.
    Type: Grant
    Filed: July 9, 1981
    Date of Patent: January 25, 1983
    Assignee: Riedel-De Haen Aktiengesellschaft
    Inventors: Rudolf Hirschberg, Bernd Schonfeld
  • Process for the preparation of a red emitting phosphor coated with red iron oxide and its application
    Patent number: 4297390
    Abstract: Filter phosphors consist of phosphor particles coated with a filter material. A phosphor which shows a red emission when excited by cathode rays may be coated with red iron oxide by producing a thin layer of pyrite on the phosphor particles and thereafter converting the said layer into hematite. Thus, the surface of the phosphor particles is evenly coated with a uniform, dense pigment layer of extreme adherence. The filter phosphors thus obtained are used in cathode ray tubes and especially in color picture tubes.
    Type: Grant
    Filed: December 31, 1979
    Date of Patent: October 27, 1981
    Assignee: Riedel-de Haen Aktiengesellschaft
    Inventors: Karl Franz, Bernd Schonfeld
  • Non-toxic, active filler for grinding disks, its use and grinding disk containing same
    Patent number: 4263016
    Abstract: In grinding disks, toxic lead chloride and antimony sulfide may be replaced by non-toxic alkali metal chloroferrates (II,III) produced by melting together alkali metal chloride, anhydrous ferric chloride and iron powder.
    Type: Grant
    Filed: August 13, 1979
    Date of Patent: April 21, 1981
    Assignee: Riedel-de Haen Aktiengesellschaft
    Inventors: Rudolf Hirschberg, Bernd Schonfeld