Cyclic pyrophosphites and compositions stabilized therewith
AssigneeCiba-Geigy Corporation
InventorsSai P. Shum, Stephen D. Pastor, Andrea R. Smith
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Abstract
Novel cyclic pyrophosphite of formula I ##STR1## are prepared from the corresponding 6-chloro and 6-oxo phosphepins or phosphocins. The cyclic pyrophosphites are effective process stabilizers for organic materials subject to thermal, oxidative or actinic induced degradation, particularly polyolefins and especially polypropylene.
Claims17
A cyclic pyrophosphites of formula I ##STR15## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are independently hydrogen, alkyl of 1 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms or phenylalkyl of 7 to 15 carbon atoms, and
- X and Y are independently a direct bond, --S-- or --CR.sub.9 R.sub.10 -- where R.sub.9 and R.sub.10 are independently hydrogen or alkyl of 1 to 18 carbon atoms, or R.sub.10 is also phenyl.
A composition stabilized against thermal, oxidative or light-induced degradation which comprises,
- (a) an organic material subject to thermal, oxidative or light-induced degradation, and
- (b) an effective stabilizing amount of a compound of formula I ##STR16## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are independently hydrogen, alkyl of 1 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms or phenylalkyl of 7 to 15 carbon atoms, and
- X and Y are independently a direct bond, --S-- or --CR.sub.9 R.sub.10 -- where R.sub.9 and R.sub.10 are independently hydrogen or alkyl of 1 to 18 carbon atoms, or R.sub.10 is also phenyl.
Dependencies are inferred from the claim text.