Asbestiform crystalline calcium sodium or lithium phosphate, preparation and compositions
AssigneeMonsanto Company
InventorEdward J. Griffith
Life of this patent
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Abstract
Asbestiform crystalline calcium M phosphate, where M is sodium or lithium, having a length to average diameter ratio of at least 5:1, can be prepared by forming a melt of a source of oxygen, calcium, phosphorus and M having a mole ratio of about 15 percent to about 30 percent M.sub.2 O, about 48 percent to about 60 percent P.sub.2 O.sub.5 and about 20 percent to about 37 percent CaO, cooling the melt within the range of about 500.degree. C. to about 750.degree. C. for a sufficient time to permit blocks of calcium M phosphate to form, and fiberizing the blocks into the asbestiform crystals. Such asbestiform crystalline calcium M phosphates are useful to prepare composites of organic polymeric materials.
Claims15
Asbestiform, crystalline calcium M phosphate wherein M is sodium or lithium.
A process for preparing asbestiform crystalline calcium M phosphate wherein M is sodium or lithium which comprises:
- (a) bringing together under reaction conditions a source of oxygen, calcium, phosphorus and M wherein the mole ratios are about 15 mole percent to about 30 mole percent M.sub.2 O, about 48 mole percent to about 60 mole percent P.sub.2 O.sub.5, and about 20 mole percent to about 37 mole percent CaO to form a melt of a phosphate salt mixture;
- (b) maintaining the phosphate salt mixture at a temperature below about the melting point of the calcium M phosphate for a sufficient time to form blocks of calcium M phosphate;
- and
- (c) fiberizing the blocks into said asbestiform crystalline calcium M phosphate.
A process for preparing asbestiform cyrstalline calcium M phosphate wherein M is sodium or lithium which comprises:
- (a) bringing together under reaction conditions a source of oxygen, calcium phosphorus and M wherein the mole ratios are about 17 mole percent to about 25 mole percent M.sub.2 O, about 48 mole percent to about 53 mole percent P.sub.2 O.sub.5 and about 25 mole percent to about 32 mole percent CaO to form a melt of a phosphate salt mixture;
- (b) maintaining the phosphate salt mixture at a temperature below about the melting point of the calcium M phosphate for a sufficient time to form blocks of calcium M phosphate;
- and
- (c) fiberizing the blocks into said asbestiform crystalline calcium M phosphate wherein the source of calcium is calcium carbonate or calcium hydroxide, and the source of phosphorus is a sodium or lithium phosphate, phosphoric acid or mixtures thereof.
A composite which comprises from about 1 to about 99 percent by weight asbestiform crystalline calcium M phosphate wherein M is sodium or lithium, having an aspect ratio of at least 10:1 and from about 1 to about 99 percent by weight organic polymeric materials.
Dependencies are inferred from the claim text.