| abstract |
Polyethylene 2,6-naphthalate (PEN) or a polyester contg. mainly PEN is prepd. by esterifying naphthalene 2,6-dicarboxylic acid, as crystalline particles with specific surface is not >1.2 m2/g, opt. contg. is not >10 mol. % of another dicarboxylic acid, with ethylene glycol, opt. contg. is not >10 mol. % of another hydroxy cpd. and polycondensing the monomeric or oligomeric ester. The PEN has reproducible high quality. |