Ammoniumtriborate, an effective new flame retardant

Abstract

This application deals with the discovery of a highly effective new flame retardant, ammoniumtriborate (NH.sub.4.B.sub.3 O.sub.5.3 CH.sub.3 -OH). Tetraborate ores, when treated in a warm methanolic suspension with ammonia and sulfurdioxide (or ammoniumsulfite), undergo a three-step transformation. First, through a displacement reaction, ammoniumtetraborate [(NH.sub.4).sub.2.B.sub.4 O.sub.7.4 H.sub.2 O] and alkali metal or alkaline earth metal sulfite are obtained. As a second step, ammoniumtetraborate spontaneously loses ammonia and transforms into a new compound, ammoniumtriborate (NH.sub.4.B.sub.3 O.sub.5.3 CH.sub.3 -OH). The third step of this reaction series can be initiated by water and heat treatment of ammoniumtriborate which undergoes a molecular change to ammoniumpentaborate (NH.sub.4.B.sub.5 O.sub.8.4 H.sub.2 O).

Dependencies are inferred from the claim text.