Precipitated silicas

US6977065B1 · kind B1 · utility

Assignee

• Degussa AG · DE

Inventors

• Heinz Esch · Wesseling, DE
• Udo Gorl · Meckenheim, DE
• Robert Kuhlmann · Lechenich, DE
• Ralf Rausch · Alzenau, DE

Key dates

• Filing date: Jun 6, 1997
• Grant date: Dec 20, 2005
• Expiry date: Jun 6, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/2982
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A precipitated silica with the following physicochemical properties:is produced by reacting alkali silicate with mineral acids at temperatures of 60° C. to 95° C. while maintaining a pH of 7.5 to 10.5 and continuously stirring, continuing the reaction to a solids concentration in the precipitation suspension of 90 g/l to 120 g/l, adjusting the pH value to a value of less than or equal to 5, filtering out, washing, drying and optionally grinding or granulating the precipitated silica. The precipitated silica is used as a filler in vulcanizable rubber compounds and vulcanizates.