Stabilized polyolefin compositions

A method of preventing oxidation comprising combining an oxidizable material with:

• a) an antioxidant represented by the following structural formula:
• b) at least one additive selected from the group consisting of
• i) at least one phosphorus stabilizer selected from the group consisting of triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bisisodecyloxy-pentaerythritol disphosphite, bis(2,4-di-tert-butyl-6-methylphenyl) pentaerythritol diphosphite, bis(2,4,6-tri-tert-butylphenyl) pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis (2,4-di-tert-butylphenyl) 4,4′-biphenylene-diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-dibenzo[d,f][1,3,2]dioxaphosphepin 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo[d,g][1,3,2]dioxaphosphocin, bis(2,4-di-tert-butyl-6-methylphenyl) methyl phosphite, bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite, (2,4,6-tri-tert-butylphenyl) 2-butyl-2-ethyl-1,3-propanediol phosphate, bis(2,4-di-cumylphenyl) pentaerythritol diphosphite and a compound represented by the following structural formula:
• ii) at least one acid stabilizer selected from the group consisting of zinc oxide, calcium lactate, natural and synthetic hydrotalcites, natural and synthetic hydrocalumites, and alkali metal salts and alkaline earth metal salts of higher fatty acids, calcium stearate, zinc stearate, magnesium behenate, magnesium stearate, sodium stearate, sodium ricinoleate and potassium palmitate, antimony pyrocatecholate, zinc pyrocatecholate and combinations thereof;
• and
• iii) at least one co-stabilizer selected from the group consisting of an antioxidant, a hindered amine stabilizer, an ultraviolet absorber, a metal deactivator, a peroxide scavenger, a hydroxylamine, a nitrone, an amine-N-oxide, a benzafuranone, an indolinone, a polyhydric alcohol, a basic co-stabilizer, a nucleating agent, a clarifier, a filler, a dispersing agent, a plasticizer, a lubricant, an emulsifier, a pigment, a rheology additive, a catalyst, a flow-control agent, an optical brightener, a flame retardant, an antistatic agent, an antimicrobial and blowing agents.

A method of preventing oxidation in a polyolefin or a mixture of polyolefins comprising combining the polyolefin or mixture of polyolefins with:

• a) an antioxidant represented by the following structural forumula:
• b) at least one additive selected from the group consisting of:
• i) at least one phosphorus stabilizer selected from the group consisting of triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bisisodecyloxy-pentaerythritol bis(2,4-di-tert-butyl-6-methylphenyl) pentaerythritol diphosphite, bis(2,4,6-tri-tert-butylphenyl) pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis (2,4-di-tert-butylphenyl) 4,4′-biphenylene-diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-dibenzo[d,f][1,3,2]dioxaphosphepin, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo[d,g][1,3,2]dioxaphosphocin, bis(2,4-di-tert-butyl-6-methylphenyl) methyl phosphite, bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite, (2,4,6-tri-tert-butylphenyl) 2-butyl-2-ethyl-1,3-propanediol phosphate, bis(2,4-di-cumylphenyl) pentaerythritol diphosphite and a compound repsresented by the following structural formula:
• ii) at least one acid stabilizer selected from the group consisting of zinc oxide, calcium lactate, natural and synthetic hydrotalcites, natural and synthetic hydrocalumites, and alkali metal salts and alkaline earth metal salts of higher fatty acids, calcium stearate, zinc stearate, magnesium behenate, magnesium stearate, sodium stearate, sodium ricinoleate and potassium palmitate, antimony pyrocatecholate, zinc pyrocatecholate and combinations thereof;
• and
• iii) at least one co-stabilizer selected from the group consisting of an antioxidant, a hindered amine stabilizer, an ultraviolet absorber, a metal deactivator, a peroxide scavenger, a hydroxylamine, a nitrone, an amine-N-oxide, a benzafuranone, an indolinone, a polyhydric alcohol, a basic co-stabilizer, a nucleating agent, a clarifier, a filler, a dispersing agent, a plasticizer, a lubricant, an emulsifier, a pigment, a rheology additive, a catalyst, a flow-control agent, an optical brightener, a flame retardant, an antistatic agent, an antimicrobial and blowing agents.