| abstract |
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 DEG -200 DEG C. and then at 200 DEG -300 DEG 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. |