GB939791A - Heat resistant materials - Google Patents

Abstract

Heat resistant material containing phosphorus oxynitride is prepared by reacting polymeric phosphonitrilic chloride with an oxide of a metal which has an anhydrous oxide in a stable valency state, which anhydrous oxide is thermally stable up to at least 350 DEG C., and which metal also has a chloride in the same valency state which is stable and nonvolatile up to at least 300 DEG C. Suitable oxides are sodium oxide, magnesium oxide, zinc oxide, calcium oxide, cuprous oxide, cupric oxide, bismuth oxide, ferric and lead monoxide. The mixture of reactants may be heated in a mould at a temperature above 150 DEG C. or may be used to impregnate glass or asbestos cloth which is then heated in a press. Powdered glass, asbestos flock, or mica flakes may be used as fillers. Products of high strength and resistant to organic solvents, water, acids, and alkalis may be formed. In Example II, layers of glass cloth are impregnated and then laminated under pressure. Example VIII yields a brittle foamed product useful as a heat insulating material. Example IX uses zinc oxide, the zinc chloride formed being extracted with ether or water.ALSO:Heat resistant material containing phosphorus oxynitride is prepared by reacting polymeric phosphoritrilic chloride with an oxide of a metal which has an anhydrous oxide in a stable valency state, which anhydrous oxide is thermally stable up to at least 350 DEG C. and which metal also has a chloride in the same valency state which is stable and non-volatile up to at least 300 DEG C. Suitable oxides are sodium oxide, magnesium oxide, zinc oxide, calcium oxide, cuprous oxide, cupric oxide, bismuth oxide, ferric oxide, and lead monoxide. The mixture of reactants may be heated in a mould at a temperature above 150 DEG C. or may be used to impregnate glass or asbestos cloth which is then heated in a press. Powdered glass, asbestos flock, or mica flakes may be used as fillers. Products of high strength and resistant to organic solvents, water, acids, and alkalis may be formed. In Example II, layers of glass cloth are impregnated and then laminated under pressure. Example VIII yields a brittle foamed product useful as a heat insulating material. Example IX uses zinc oxide, the zinc chloride formed being extracted with ether or water.