Anhydride-cured epoxy resins, quaternary phosphonium compound

Quaternary Phosphonium Compound Latent Accelerators for Anhydride-Cured Epoxy Resins... [Pg.47]

Quaternary phosphonium compounds have been found to be extremely effective latent accelerators for anhydride-cured epoxy resins employed in electrical insulation applications. Used at very low concentrations (0.01 to 0.25% level) in these resins, they have been found to give very fast gel times at elevated temperatures combined with very good storage stability properties at room temperature. Results show that the quaternary phosphonium compounds having non-halide anions give the best compromise of gel reactivity, storage stability and electrical properties. Comparison with other types of latent accelerators reveal that the quaternary phosphonium compounds are among the most effective additives yet discovered for epoxy-anhydride resin systems. [Pg.56]

Most of the data reported here will be concerned with bisphenol A epoxy resin systems cured with the liquid anhydride, 1-methyltetrahydrophthalic anhydride (the Union Carbide commercial designation for this material is ZZLA-0334). However, these quaternary phosphonium compounds have also been shown to be effective with other anhydrides such as hexahydrophthalic anhydride (HHPA). [Pg.49]

Table IV. Electrical Properties of Cured Epoxy-Anhydride Resins Containing Various Quaternary Phosphonium Compounds ...