| 摘要 |
New and improved thermoplastic barrier compositions exhibiting low permeability to carbon dioxide and water vapor are disclosed comprising an ultrahigh molecular weight poly(1,4-butylene terephthalate) resin having an intrinsic viscosity of above about 1.5 dl/g as measured in a <6><0>/40 mixture of a phenol/tetrachlorethane at 30 DEG C and a modifier therefor comprising an amorphous copolyester copolymer derived from a glycol portion comprising 1,4-cyclohexanedimethanol or a mixture of 1,4-cyclohexanedimethanol and ethylene glycol in molar ratios of about 1:4 to 4:1, respectively, and an acid portion comprising terephthalic acid, isophthalic acid, a mixture of the two acids, provided that when the glycol portion comprises 1,4-cyclohexanedimethanol alone, the acid portion comprises a mixture of terephthalic and isophthalic acids. The compositions are readily thermoformable, even by blow molding techniques and have high melt strength in molten form. They have excellent resistance to permeation by water vapor and carbon dioxide. New and improved single and multiwall barrier containers formed from the compositions are also disclosed. |
