Patents Assigned to Joseph Crosfield & Sons, Ltd.
  • Fine silicas
    Patent number: 3954944
    Abstract: This invention discloses a new form of wet precipitated silica which is characterised in terms of energy required to breakdown particles and a defined thickening effect. A multistage precipitation and flocculation production process is also disclosed in which primary silica particles are prepared and flocculated using an alkali metal salt solution and further silica precipitated in the presence of the salt, the pH of the mixture reduced and the silica isolated, purified carefully dried and optionally milled.
    Type: Grant
    Filed: March 8, 1973
    Date of Patent: May 4, 1976
    Assignee: Joseph Crosfield & Sons, Ltd.
    Inventors: Derek Aldcroft, Donald Barby, Anthony Leonard Lovell, James Philip Quinn