Elastomer coated fillers and composites thereof comprising at least 60 by wt. of a hydrated filler and an elastomer containing an acid substituent

摘要

The impact resistance of flame retardant composites, especially thermoplastic molding compounds containing over 60% hydrated mineral filler such as Al(OH).sub.3 or Mg(OH).sub.2 is improved by coating the filler with 1 to 20% of an elastomer. The composite will fail by crazing or shearing rather than by brittle fracture. A well bonded elastomeric interphase results by utilizing acidic substituted resins such as ethyl- hexyl acrylate-acrylic acid copolymers which bond to and are cross-linked by the basic filler particles. Further improvement in impact resistance is provided by incorporating 1 to 10% of a resin fiber reinforcement such as polyvinyl alcohol fibers that decompose to yield at least 30% water when heated to decomposition temperature.