Phosphazene composition

1. A phosphazene composition comprising at least one phosphazene compound, wherein the phosphazene composition has a content of volatile components originated therein of not less than 0.02% by weight and not more than 1.0% by weight based on the total weight of the phosphazene composition when it is heated at 200° C. for 2 hours, and wherein the composition has a weight retention according to TGA of not higher than 15% by weight at 500° C. when it is heated from room temperature to 600° C. at a heating rate of 10° C./min in an inert gas atmosphere.

2. A phosphazene composition according to claim 1 which has a water content of not more than 1000 ppm measured by Karl Fischer's method at 150° C.

3. A phosphazene composition according to claim 1 which has a water content of not more than 650 ppm measured by Karl Fischer's method at 150° C.

4. A phosphazene composition according to claim 1 which contains not less than 95% by weight of cyclic phosphazene compounds based on the total weight of the phosphazene composition.

5. A phosphazene composition according to claim 1 which has a content of one or more residual alkali metal elements of not more than 100 ppm, a content of compounds having a P—OH bond of not more than 1% by weight and a chlorine content of not more than 1000 ppm based on the total weight of the phosphazene composition.

6. A phosphazene composition according to claim 1 which has a content of one or more residual alkali metal elements of not more than 50 ppm, a content of compounds having a P—OH bond of not more than 1% by weight and a chlorine content of not more than 500 ppm based on the total weight of the phosphazene composition.

7. A phosphazene composition according to claim 1 , wherein the phosphaze compound has not less than 90% of phenoxy groups as the substituents based on all the substituents and the phosphazene composition has a phosphorus content of 13.0–14.5% by weight based on the total weight of the phosphazene composition.

8. A phosphazene composition according to claim 1 which has a weight retention according to TGA of not higher than 10% by weight at 500° C. when it is heated from room temperature to 600° C. at a heating rate of 10° C./min in an inert gas atmosphere.

9. A phosphazene composition according to claim 1 which has a bulk density of not lower than 0.45 g/cm 3 .

10. A flame retardant resin composition which comprises a resin and a phosphazene composition according to any one of claims 1 – 9 .

11. A flame retardant resin composition according to claim 10 , wherein the resin comprises at least one hardening resin selected from the group consisting of unsaturated polyester resins, vinyl ester resins, diallyl phthalate resins, epoxy resins, cyanate resins, xylene resins, triazine resins, phenolic resins, urea resins, melamine resins, benzoguanamine resins, urethane resins, ketone resins, alkyd resins, furan resins, styrylpyridine resins, silicone resins and synthetic rubbers.

12. A flame retardant resin composition according to claim 10 , wherein the resin comprises at least one thermoplastic resin selected from the group consisting of polycarbonates, polyphenylene ethers, polyphenylene sulfides, polypropylenes, polyethylenes, polystyrenes, ABS resins, polyalkylene terephthalates, polyamides, thermotropic liquid crystals and elastomer-containing polystyrenes.

13. A flame retardant resin composition according to claim 10 which has a concentration of phosphorus of 0.5–8.0% by weight.

14. A flame retardant resin composition according to claim 10 which is used for parts or casings of electric and electronic equipment used in a high-frequency field of not less than 1 GHz.

15. A phosphazene composition according to claim 1 , wherein said at least one phosphazerie compound contains cyclic trimer and/or tetramer compounds in an amount of not less than 80% by weight.

16. A flame retardant resin composition which comprises a resin and a phosphazene corn position according to claim 15 .