Phosphoric Acid → Zinc Phosphate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of iron powder and zinc stearate and a mono, di or triester of phosphoric acid and long-chain alcohols, such as a mixture of phosphoric acid monostearyl ester and phosphoric acid distearyl ester having a melting point of 70° C., as antitack agent was pressed to form a molded article, the proportion of the antitack agents with respect to the weight of the iron powder being approximately 1.7% by weight, and the atomic ratio Zn:P being approximately 3:2. The molded article was heated in a nonreducing atmosphere, such as in nitrogen, to a maximum temperature of approximately 550° C., the antitack agents pyrolyzing to ZnO and P2O5, and the oxides reacting with each other to form zinc phosphate. As was determined, zinc phosphate has a high specific electrical resistance, adheres well to metals and protects especially iron from corrosion. The composite material obtained is suitable as a soft magnetic material for fast-acting electric valves.

Herkunft & Nachweise