Silica sols, a process for the production of silica sols and use of the sols

US5447604A · kind A · utility

Assignee

• Eka Nobel AB · SE

Inventors

• Hans Johansson · Gothenburg, SE
• Bo V. Larsson · Partille, SE

Key dates

• Filing date: May 8, 1992
• Grant date: Sep 5, 1995
• Expiry date: May 8, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01B33/1485
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Silica sols which have a large alkali excess, i.e. a low molar ratio SiO.sub.2 to M.sub.2 O, and which contain silica particles with a high specific surface area. The silica sols can be prepared through acidification of a water glass solution and subsequent alkalization of the acid sol to the molar ratio in question. The sols are particularly suitable for use as additives, in combination with cationic polymers, in papermaking.