| 摘要 |
Flameproof polyamide moulding batches contain, as flameproofing agent, 0.3-20wt.% powdered red P, encapsulated in microcapsules of (in)organic material having softening point >=260 degrees C. The capsule walls pref. consist of reaction prods. of aromatic bis-hydroxy cpds. and cyanuric halides, e.g., crosslinked reaction prods. of bisphenols and cyanuric halides; a melamine-HCHO resin; SiO2, silicates, alkaline earth metal oxides, Ti- or Al-oxides. Compsns. can be used for prodn. of injection-moulded articles, esp. electrical equipment. Microencapsulation prevents reaction of P and polyamide to form toxic P-H cpds. during processing. E.g., encapsulated red P can be stirred >2 hrs. in molten polyamide-6, or -6,6 at 260-290 degrees C without phosphine formation. |
