| abstract |
Multi-layered, coinjection stretch blow molded containers are obtained by stretch-blow molding a preform prepared by coinjection-molding a polyester resin and an EVOH resin mixture. Even though not having an adhesive resin layer, the containers have good impact delamination resistance and good gas-barrier properties. Their transparency is high, and the resin melts for them are stable. The containers comprise thermoplastic polyester layers (layers a) and a resin composition layer (layer b) of a mixture of two ethylene-vinyl alcohol copolymers (b1, b2) with the layers a being kept in direct contact with the both surfaces of the layer b, wherein the dispersion morphology of the resin composition is such that the particles of the ethylene-vinyl alcohol copolymer (b2) having an ethylene content of from 35 to 48 mol% and a degree of saponification of from 92 to 99 % are dispersed in the matrix of the ethylene-vinyl alcohol copolymer (b1) having an ethylene content of from 25 to 40 mol% and a degree of saponification of at least 99 %, the resin composition gives at least two peaks for crystal fusion in its differential scanning calorimetry (DSC), the difference between b1 and b2 in the ethylene content falls between 8 and 23 mol%, the difference therebetween in the degree of saponification falls between 1 and 8 %, and the blend ratio of b1 to b2 falls between 60/40 and 90/10. |