摘要 |
A new linear polyester contains in its chain the residues of a hydroxy-bis(hydroxyalkoxy)xanth-9-one e.g. polyethylene terephthalate containing such residues which act as a UV stabilizer. Processes for the preparation of the polymers include the reaction of a dibasic acid, glycol and 1,3,6-trihydroxyxanthone whereby only two of the xanthone hydroxyl groups take part in the polyester-forming reaction. |