Polyester compositions of low residual aldehyde content
AssigneeCiba Specialty Chemicals Corporation
InventorsStephen Andrews, Dario Lazzari, Paul Odorisio, Dirk Simon
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Abstract
A mixture of a polyester, such as poly(ethylene terephthalate) PET, and a second polymer which is poly(vinyl alcohol) or an ethylene/vinyl alcohol copolymer when extrusion compounded exhibits a lower residual acetaldehyde content than does PET alone when similarly treated. The invention pertains to any polyester used in the manufacture of bottles or containers which in turn are used to store consumer materials, especially food, beverages and most especially water.
Claims15
A polyester composition, stabilized against the formation of aldehydic contaminants during melt processing of said polyester, which comprises
- (a) a polyester, and
- (b) an effective stabilizing amount of a second polymer which is poly(vinyl alcohol) or an ethylene/vinyl alcohol copolymer, and
- wherein the polyester of component (a) is 99.925-99.995% by weight of the stabilized composition;
- and the second polymer of component (b) is 0.075 to 0.005% by weight of the stabilized composition.
A process for preventing the formation of aldehydic contaminants during melt processing of a polyester which comprises
- incorporating into said polyester 0.075 to 0.005% by weight of a second polymer which is poly(vinyl alcohol) or an ethylene/vinyl alcohol copolymer.
Dependencies are inferred from the claim text.