Porous silicic acid and its production

US4006175A · kind A · utility

Assignee

• Dynamit Nobel GmbH · DE

Inventors

• Erich Termin
• Arnold Lenz · Kornwestheim, DE
• Otto Bleh

Key dates

• Filing date: Jul 24, 1974
• Grant date: Feb 1, 1977
• Expiry date: Jul 24, 1994

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01B33/163
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Porous silicic acid having a specific surface of about 50 to 1000 m.sup.2 /g and having an anion content below the chemically determinable limit of detection is made by hydrolyzing methyl or ethyl silicate or polymethyl or polyethyl silicate with about 70 to 120% of the stoichiometric amount of water with moderate stirring. Hydrolysis activators such as acids or bases may be present as well as alcoholates of oxides of transition metals which then appear in the end product. Alcohol may also be present to facilitate hydrolysis. The products are characterized by marked purity and their specific surface can be closely and reproducibly controlled.