Process for the hydrophobization of pyrogenically produced silica

US4503092A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Hans Klebe · Rheinfelden (Baden), DE
• Detlev Koth · Bocholt, DE
• Dieter Kerner · Midland Park, US
• Josef Schmid · Hohenems, AT
• Manfred Schmid · Neutraubling, DE

Key dates

• Filing date: Mar 23, 1983
• Grant date: Mar 5, 1985
• Expiry date: Mar 23, 2003

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2004/84
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Pyrogenically produced silica after separation of the hydrogen halide is mixed with nitrogen and conveyed into a cyclone. After separation of the gases, which are returned into the cooling stretch of the production apparatus, the silica is first mixed with organohalosilane and nitrogen and subsequently with steam and nitrogen. Subsequently the hydrophobization reaction is carried out in known manner in a fluidized bed reactor. The reaction waste gases are returned into the cyclone.