Allied Corporation

David H Wertz

Dusan C Prevorsek

Tse C Wu

Purified aromatic dicyanates are cured with a catalyst which is an Mn(II), Ag(II), Fe(III), Bi(III), In(III) or Hf(IV) salt at 150.degree.-200.degree. C. and then at 200.degree.-300.degree. C. for a time sufficient to cure the dicyanate without causing color formations to the extent of a Yellowness Index over 30. In some forms the dicyanate is combined with the catalyst and a thermoplastic.

Low color compositions comprising a cross-linked polycyanurate polymer

A monomeric aromatic dicyanate is purified to remove color forming impurities, combined with a zinc salt catalyst and cured first below 200.degree. C. and then for a limited time at or above 200.degree. C., either alone or in admixture with or on a thermoplastic polymer. For example, purified 2,2-bis(4-cyanatophenyl)propane is purified, combined with a poly(ester carbonate) and zinc chloride, and then cured at increasing temperatures from 150.degree. C. to 250.degree. C.

Growing community of inventors

Morristown, NJ, United States of America

David H Wertz