Fibrous magnesium oxide and process for production thereof

Abstract

A magnesium oxide having a cubic system needle-like crystal structure and a length-to-diameter ratio, determined by an electron microscope at a magnification of 10,000, of at least about 5; and a process for producing a magnesium oxide having a cubic system needle-like crystal structure, which comprises calcining a basic magnesium compound having a needle-like crystal structure expressed by the following formula Mg(OH).sub.2-nx A.sub.x.sup.n-.mH.sub.2 O wherein A.sup.n- represents a monovalent (n=1) to tetravalent (n=4) anion, x is 0.2.ltoreq.x.ltoreq.0.5, and m is 0<m.ltoreq.2, or a magnesium hydroxide having a needle-like crystal structure, at a temperature of not less than about 400.degree. C. to convert it to the magnesium oxide.

Dependencies are inferred from the claim text.