| abstract |
Catalytic acceleration of polycondensation of polyesters (I) of aliphatic or aromatic dicarboxylic acids (cyclohexanedicarboxylic, terephthalic, isophthalic or 2,6-naphthalenedicarboxylic acid) and (cyclo)aliphatic diols (ethylene glycol, butan-1,4-diol, pentaerythritol, hexan-1,6-diol, decalin-2,6-dimethanol or cyclohexane-1,4- or -1,3-dimethanol) by direct esterification or ester exchange with methyl dicarboxylates and their copolyesters. The novelty is that special silicates (II) are added and the amt. of conventional co-catalyst based on Sb(III) and/or Ti(IV) cpds. is reduced drastically. This leads to higher intrinsic viscosities during both melt and solid phase condensation. |