Conversion of organophosphonic acids into their salts using intense shear

US4851525A · kind A · utility

Assignee

• Henkel Kommanditgesellschaft auf Aktien · DE

Inventors

• Willi Wuest · Ratingen, DE
• Hubert Harth · Goldkronach, DE
• Dirk Springer · Haan, DE
• Franz Foerg · Langenfeld, DE

Key dates

• Filing date: Aug 12, 1987
• Grant date: Jul 25, 1989
• Expiry date: Aug 12, 2007

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F9/59
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Process for the conversion of an organophosphonic acid of the formula ##STR1## in which n=3-5 and R=H or C.sub.1 -C.sub.3 alkyl, into an alkali metal or ammonium salt comprising reacting the moist filter cake which accumulates during the production of organophosphonic acids by known processes (water content 10 to 40% by weight) with anhydrous or concentrated aqueous alkali metal hydroxide or ammonia and exposing the paste formed, which has a water content of from 20 to 80% by weight, to intense shear forces in mixing, dispersing, or kneading units, water being removed from the paste under reduced pressure and with application of heat until the paste changes into a free-flowing powder.