FIELD: polymers, chemical technology.
SUBSTANCE: invention relates to a method for preparing co-polyester of polyethylene phthalate. This co-polyester shows diminished cracking under tension and comprises terminal carboxyl groups in the amount between 25 and 55 microequivalents per gram of indicated co-polyester, and intrinsic viscosity value at least 0.65. Method involves interaction of terephthalic acid or its ester equivalent and other carboxylic acid with ethylene glycol by the esterification reaction followed by condensation, addition of about 10-100 microequivalents per gram of indicated co-polyester of anhydride taken among the group consisting of succinic, glutaric, maleic, benzoic and phthalic anhydride to obtain polyethylene terephthalate co-polyester. Also, invention relates to polyethylene terephthalate co-polyester, preliminary shaped blank, bottle and composition. Invention provides preparing polyester that elicits the enhanced resistance against cracking under tension.
EFFECT: improved preparing method, improved properties of polyester.
14 cl, 6 tbl, 5 ex
