Process for working up dispersions of elastic-thermoplastic or thermoplastic plastics

US4113796A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Jurgen H. Bischoff · Dormagen, DE
• Friedrich Kowitz · Dormagen, DE
• Karl-Heinz Ott
• Herbert Schuster · Grafing, DE
• Harry Rohr · Frechen, DE
• Hans-Peter Weitzel · Reischach, DE

Key dates

• Filing date: Sep 26, 1973
• Grant date: Sep 12, 1978
• Expiry date: Sep 26, 1993

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F6/22
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

Isolating thermoplastic or thermoelastic polymers in the form of a powder of limited water and precipitant content and uniform grain size from their aqueous dispersions wherein PA1 (i) a polymer dispersion and a precipitant are intensively mixed at an uptake of mechanical energy of 0.2 to 0.6 KWh per m.sup.3 of dispersion thus causing high turbulence, PA1 (ii) the polymer is precipitated while in this state of high turbulence at a temperature below the sintering temperature of the polymer, PA1 (iii) the precipitated polymer particles are agglomerated and hardened while still in contact with the aqueous liquor either in one or in several stages, and PA1 (iv) the aqueous liquor and agglomerated polymer particles are separated from one another.