| 摘要 |
PURPOSE: To obtain at low cost a polyester excellent in boiling water resistance, toughness, heat distortion temperature, etc., useful for e.g. fiber-reinforced plastics, by esterification between saturated polybasic acid(s) and a polyhydric alcohol followed by adding an unsaturated polybasic acid to the system to carry out a further esterification followed by deglycolation. CONSTITUTION: Esterification is conducted between a saturated polybasic acid (anhydride) component containing 5-40mol% of compound(s) of formula, HOOC (CH2 )n COOH ((n) is 4-10) (e.g. adipic acid, sebacic acid) and a polyhydric alcohol component to an esterification rate of >=60%, and anα,β-unsaturated polybasic acid (anhydride) component is then added to the reaction system to carry out a further esterification; and when the acid value of the reaction system comes to 90-15, the pressure is reduced to 93-7hPa to conduct a deglycolation, thus the objective polyester with a number-average molecular weight of >=3500 is obtained.
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