Five-component copolyester, process for preparation thereof, and shaped articles thereof

Claim 1

A laminated structure, in the stretched or non-stretched state, composed of a layer of a five-component copolyester composed of the following components (a) to (d) and having the following characteristics (e) and (f): (a) 25 to 45 mole %, based on the total moles of the components (a), (b), (c) and (d) of the copolyester, of two aromatic dicarboxylic acid components composed of 70 to 90 mole % of an isophthalic acid component and 30 to 10 mole % of an aromatic dicarboxylic acid compound other than the isophthalic acid component, each based on the total moles of the two aromatic dicarboxylic acid components, (b) 45 to 50 mole %, based on the total moles of the components (a), (b), (c) and (d) of the copolyester, of a diol component composed of 50 to 100 mole % of an ethylene glycol component and 0 to 50 mole % of a diol component other than the ethylene glycol component, each based on the total moles of the two diol components, (c) 2 to 55 mole %, based on the total moles of the components (a), (b), (c) and (d) of the copolyester, of an aromatic monohydroxy-monocarboxylic acid component having 7 to 12 carbon atoms, and (d) 0.01 to 2 mole %, based on the total moles of the components (a), (b), (c) and (d) of the copolyester, of a polyfunctional compound component having 3 to 15 carbon atoms and at least three functional groups selected from the class consisting of carboxyl and hydroxyl groups; and (e) an intrinic viscosity [η], determined at 25° C. in a mixed solvent of phenol and tetrachloroethane in a weight ratio of 1:1, of 0.5 to 1.5 dl/g, and (f) a glass transision temperature of 50° to 120° C. and a layer of poly(ethylene terephthalate) or a copolyester thereof having ethylene terephthalate as a main structural unit.