Systems and compositions for color stabilization of polymer
View Patent ↗Systems and compositions have a three component antioxidant blend for extending color and clarity of a thermoplastic polymer. The antioxidant blend includes a zinc dithiocarbamate, a phenolic and a thioether with a weight ratio range of about 1-2:1-2:1-2. A loading level of the antioxidant blend is from about 0.01 wt. % to about 1 wt. % of the systems and compositions.
1. An antioxidant additive for stabilization of polymers comprising:
(a) an antioxidant fraction consisting of
tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)methane, and
distearyl thiodiproprionate, and
(b) a zinc-containing compound, comprising zinc dithiocarbamate, wherein the tetrakis:distearyl thiodiproprionate:zinc dithiocarbamate blend has a weight ratio of about 1:2:1.
2. The antioxidant additive according to claim 1 , wherein the zinc dithiocarbamate is zinc dibutyl dithiocarbamate.
3. The antioxidant additive according to claim 1 , wherein the zinc dithiocarbamate is zinc diamyldithiocarbamate or piperidinium pentamethylene dithiocarbamate.
4. A polymer composition, comprising:
a polymer package comprising a polypropylene and about 0.1% to about 1% of an additive package comprising
(a) an antioxidant fraction consisting of
tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)methane, and
distearyl thiodiproprionate, and
(b) a zinc-containing compound, comprising zinc dithiocarbamate, wherein the tetrakis:distearyl thiodiproprionate:zinc dithiocarbamate blend has a weight ratio of about 1:2:1.
5. The composition according to claim 4 , wherein the additive is present at about 0.2%.
6. The composition according to claim 4 , wherein the zinc dithiocarbamate is zinc dibutyl dithiocarbamate.
7. The composition according to claim 5 , wherein the zinc dithiocarbamate is zinc dibutyl dithiocarbamate.
8. The composition according to claim 4 , wherein the polymer package consists essentially of polypropylene.