| 摘要 |
PURPOSE: To provide a copolyester which contains a specific triol component bearing a benzene nucleus at a specific ratio, thus has a high melt viscosity, excellent melt moldability and give monolayer molded hollow products excellent in transparency and heat resistance. CONSTITUTION: This polyester mainly comprises (A) the diol units mainly of ethylene glycol and the dicarboxylic units of terephthalic acid, contains (B) at least one of the triol units of formula I [A is -CH2 CH2 -, -CH(CH3 )CH2 -; B is a divalent hydrocarbon, carbonyl, sulfonyl, O, direct bond (-); p, q, r are each 1-8] and formula II (s, t, u are each 1-8) where the content of the triol units is 0.01-1 mole % based on the total moles of all diols and triols units. This copolyester preferably has an intrinsic viscosity of 0.6-1.5dl/g and melt viscosity of 5×10<4> -5×10<6> poise and 5×10<3> -5×10<5> poise under 0.1rad/sec and 100rad/sec shear rate at 270 deg.C.
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