| abstract |
UV stable linear polyesters, e.g. PET, contain in their chain copolymerized bis(hydroxyalkoxy)xanth-9-ones, preferably 3,6-bis-(2-hydroxyethoxy)xanth -9-ones. The polymers are obtained by polymerization in the presence of a tetrahydroxy benzophenone, preferably the 2,2',4,4'- isomer. The method of polymerizing in the presence of dihydric phenols to obtain ethoxyaryloxy polyesters is also described. |