By regulating the content of {TAIL ~ the polyamide resin} and {HEAD ~ the concentration} of the phosphorus compound therein so that the value of the formula 1 falls within the range of 25 or less, the polyester based resin composition having improved gas barrier properties with little darkening due to the deposition of metallic antimony can be obtained 
By regulating the content of { TAIL ~ the polyamide resin } and { HEAD ~ the concentration } of the phosphorus compound therein so that the value of the formula 1 falls within the range of 25 or less , the polyester based resin composition having improved gas barrier properties with little darkening due to the deposition of metallic antimony can be obtained
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH