| 摘要 |
<p>A cocondensation polyester according to the present invention is substantially linear and is composed of mononuclear aromatic dicarboxylic acid constituent units comprising isophthalic acid constituent units as their main ingredient, (b) binuclear aromatic dicarboxylic acid constituent units comprising 2,6-naphthalenedicarboxylic acid constituent units as their main ingredient, (c) diol constituent units comprising ethylene glycol constituent units as their main ingredient, and (d) polyfunctional constituent units derived from a polyfunctional compound having 3 or more carboxyl groups and/or hydroxyl groups in total and 3 to 15 carbon atoms, said polyester having an intrinsic viscosity [ eta ] of 0.5 to 1.5 dl/g and a glass transition temperature of 70 DEG C or higher. A second cocondensation polyester according to the present invention is substantially linear and is composed of the above-mentioned (a) mononuclear aromatic dicarboxylic acid constituent units, (b) binuclear aromatic dicarboxylic acid constituent units, (c) diol constituent units, (d) polyfunctional constituent units, and additional (e) aliphatic dicarboxylic acid constituent units comprising succinic acid constituent units as their main ingredient, said polyester having an intrinsic viscosity [ eta ] of 0.5 to 1.5 dl/g. Furthermore, the present invention provides a process for preparing these cocondasation polyesters, and uses thereof by utilizing excellent gas barrier properties and transparency thereof.</p> |
