Method for producing hollow bodies having enclosed freely displaceable particles

US9181136B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Julien Courtois · Ludwigshafen, DE
• Carsten Schips · Speyer, DE
• Petra Lutz-Kahler · Weiterstadt, DE
• Willi Riegel · Waghäusel, DE
• Mohammed Abboud · Riverside, US

Key dates

• Filing date: Jan 19, 2011
• Grant date: Nov 10, 2015
• Expiry date: May 23, 2032

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C04B2111/40
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The invention relates to a method for producing hollow bodies having freely displaceable particles enclosed in the hollow body, wherein a) a gel-forming liquid in which the particles are suspended is brought into a cross-linking bath, b) the gel cores that form are isolated, c) the cores are coated with a composition comprising sinterable material and a binder, and d) the coated cores are subjected to a heat treatment wherein the gel and the binder are expunged and the sinterable material is sintered into a closed shell. The gel forming material is, for example, sodium alginate, and the cross-linking bath comprises calcium ions. The particles are selected, for example, from ZrO2, Al2O3, TiO2, and SiO2 or mixtures thereof. The sinterable material is, for example, a metal powder such as carbonyl iron powder.