| 摘要 |
The invention relates to a partially crystalline polyethylene terephthalate having a degree of polymerization which is greater than 80, particularly greater than 100, produced from a diol component and a dicarboxylic acid component, wherein according to the invention the DSC melting point, when measured with a heating rate of 10° C./Min during the first passage and second passage, is less than the melting temperature (Tm) of a comparable standard polyethylene terephthalate which is dependent upon the comonomer content. The inventive method for the production of a polyethylene terephthalate comprises a step for the production of a polycondensate prepolymer melt; a step for the formation of granules and the solidification of the polycondensate prepolymer melt; a step for increasing the degree of crystallization of the prepolymer granulates and a step for increasing the molecular weight of the granulates by means of solid phase polycondensation, wherein according to the invention a treatment temperature of 220° C. in step d) is not exceeded. |
