Oxidation resistant co:polyetherester compsn. - contg. phenolic antioxidant and having chemically bound hindered amine photostabiliser units

摘要

A copolyetherester, having recurring long chain ester units and short chain ester units joined head-to-tail through ester linkages, is stabilised against oxidative degradation due to exposure to heat and light by the presence of effective concns. of a phenolic antioxidant and copolymerised hindered amine photostabiliser units of formula (where A is ethylene and/or propylene; X is 2-18C divalent hydrocarbyl; and n+m = 5-40). The photostabiliser units are connected to the ester units in the copolyetherester through ester linkages. The copolyetherester contains 15-95 wt. % of short chain ester units of formula (I) and the balance long chain ester units of formula (II) (where D is the residue of a diol of mol. wt. 250; G is the residue of a polyalkylene oxide glycol of mol. wt. 400-6000 and having a C:O atomic ratio of 2.0-4.3; and R is the residue of an aromatic dicarboxylic acid of mol. wt. 300). The polymer is a thermoplastic elastomer which has outstanding resistance to degradation due to heat and light ageing. Blooming of the photostabiliser is not possible because it is chemically combined with the polymer.