| abstract |
Disclosed are polyester pellets made of a polyester which comprises dicarboxylic acid constituent units derived from dicarboxylic acids containing terephthalic acid and isophthalic acid and diol constituent units derived from diols containing ethylene glycol and 1,3-bis(2-hydroxyethoxy)benzene, and which has the properties: constituent units derived from terephthalic acid are 15 to 99.5 % by mol and constituent units derived from isophthalic acid are 0.5 to 85 % by mol, both based on the total amount of dicarboxylic acid isophthalic acid constituent units (i); constituent units derived from ethylene glycol are 25 to 99.5 % by mol and constituent units derived from 1,3-bis(2-hydroxyethoxy)benzene are 0.5 to 75 % by mol, both based on the total amount of the diol constituent units (ii); the intrinsic viscosity is in the range of 0.5 to 1.5 dl/g; and the melting point (Tm (° C.)), as measured by a differential scanning calorimeter, satisfies the formula [1/527-0.0017·ln(1-(m I +m B )/200)] −1 -273<Tm≦265; said polyester pellets having a density of not less than 1,350 kg/m 3 . Also disclosed is a process for preparing the polyester pellets. The polyester pellets are excellent in gas barrier properties, transparency and heat resistance and hardly generate acetaldehyde. |