Stabilization of organic materials
Organic materials which possess outstanding stability to oxidative, thermal or light-induced degradation comprise as stabilizers at least one compound of the formula (I) wherein the general symbols are as defined in claim 1 . The compounds of formula I are especially useful as stabilizers for protecting polymers and lubricants against oxidative, thermal or light-induced degradation and as scavengers for oxidized developer in color photographic material.
1. A composition comprising
a) a natural, semisynthetic or synthetic polymer and
b) at least one compound of formula
wherein
R 10 is hydrogen or C 1 -C 25 alkyl,
R 2 and R 3 are hydrogen,
R 4 and R 5 are hydrogen,
R 6 is unsubstituted or C 1 -C 4 alkyl-substituted phenyl and
R 16 and R 18 are C 1 -C 25 alkyl and R 17 and R 19 are hydrogen.
2. A composition according to claim 1 , wherein
R 10 is hydrogen or C 1 -C 12 alkyl and
R 16 and R 18 are C 1 -C 18 alkyl.
3. A composition according to claim 1 , wherein
R 10 is hydrogen or C 1 -C 8 alkyl and
R 16 and R 18 are C 1 -C 12 alkyl.
4. A composition according to claim 1 , wherein
R 10 is hydrogen or C 1 -C 4 alkyl and
R 16 and R 18 are C 1 -C 4 alkyl.
5. A composition according to claim 1 , comprising as component (a) a thermoplastic polymer.
6. A composition according to claim 1 , comprising as component (a) a polyolefin.
7. A composition according to claim 1 , in which component (b) is present in an amount of from 0.0005 to 10% based on the weight of component (a).
8. A composition according to claim 1 , comprising further additives.
9. A composition according to claim 8 , comprising as further additives phenolic antioxidants, light-stabilizers and/or processing stabilizers.
10. A compound of formula
wherein
R 10 is hydrogen or C 1 -C 25 alkyl,
R 2 and R 3 are hydrogen,
R 4 and R 5 are hydrogen,
R 6 is unsubstituted or C 1 -C 4 alkyl-substituted phenyl and
R 16 and R 18 are C 1 -C 25 alkyl and R 17 and R 19 are hydrogen.
11. A compound according to claim 10 , wherein
R 6 is phenyl,
R 10 is hydrogen or C 1 -C 4 alkyl and
R 16 and R 18 are C 1 -C 4 alkyl.
12. A process for stabilizing a natural, semisynthetic or synthetic polymer against oxidative, thermal or light-induced degradation, which process comprises incorporating therein or applying thereto at least one compound of formula
wherein
R 10 is hydrogen or C 1 -C 25 alkyl,
R 2 and R 3 are hydrogen,
R 4 and R 5 are hydrogen,
R 6 is unsubstituted or C 1 -C 4 alkyl-substituted phenyl and
R 16 and R 18 are C 1 -C 25 alkyl and R 17 and R 19 are hydrogen.