摘要 |
<p>A matrix resin system, for the preparation of composite parts, is comprised of a major amount of cyanate resin and an epoxy resin modified by reaction with an isocyanate. The resin system can be toughened by the addition of thermoplastic material, the toughness improvement being enhanced by the addition of a polyester rubber additive. The modified epoxy resin system is itself a resin having good modulus and Tg characteristics. The resin is cured at temperatures of 250-400°F in the presence of a metallic complex catalyst, and OH donor.</p> |