Antioxidants for polyamides

Abstract

A composition comprising a polyamide, 0.01% to 5% by weight of at least one primary antioxidant based on the total mass of the polyamide, and at least one secondary antioxidant.

1 - 5 . (canceled) 
     
     
         6 . A composition comprising a polyamide, 0.01% to 5% by weight of at least one primary antioxidant based on the total mass of the polyamide, and at least one secondary antioxidant,
 wherein the at least one primary antioxidant consists of a sterically hindered phenol of formula 1:   
       
         
           
           
               
               
           
         
         wherein n is from 1 to 5, and 
         wherein the at least one secondary antioxidant is selected from the group consisting of at least one phosphite, at least one phosphonite, and combinations thereof. 
       
     
     
         7 . The composition of  claim 6 , wherein the at least one secondary antioxidant comprises the at least one phosphite. 
     
     
         8 . The composition of  claim 7 , wherein the at least phosphite is selected from the group consisting of a triphenyl phosphite, a diphenylalkyl phosphite, a phenyldialkyl phosphite, tris-(nonylphenyl)-phosphite, triauryl phosphite, trioctadecyl phosphite, distearyl-pentaerythrite diphosphite, tris-(2,4-di-tert-butylphenyl)-phosphite, diisodecylpentaerythrite-diphosphite, bis-(2,4-di-tert-butylphenyl)-pentaerythrite diphosphite, bis-(2,6-di-tert-butyl-4-methylphenyl)-pentaerythrite diphosphite, bis-isodecyloxy-pentaerythrite diphosphite, bis-(2,4-di-tert-butyl-6-methylphenyl)-pentaerythrite diphosphite, bis-(2,4,6-tri-tert-butylphenyl)-pentaerythrite diphosphite, tristearyl-sorbit-triphosphite, bis-(2,4-di-tert-butyl-6-methylphenyl)-methyl phosphite, bis-(2,4-di-tert-butyl-6-methylphenyl)-ethyl phosphite, and combinations thereof 
     
     
         9 . The composition of  claim 6 , wherein the at least one secondary antioxidant comprises the at least one phosphonite. 
     
     
         10 . The composition of  claim 9 , wherein the at least one phosphonite is selected from the group consisting of tetrakis-(2,4-di-tert-butylphenyl)-4,4′-biphenylene-diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl- 12H-dibenz[d,g]-1,3,2-dioxaphosphocine, 6-fluoro-2,4,8,10-tetra-tert-butly-12-methyl-dibenz[d,g]-1,3,2-dioxaphosphocine, and combinations thereof. 
     
     
         11 . The composition of  claim 6 , wherein the at least one secondary antioxidant comprises the at least one phosphite and the at least one phosphonite. 
     
     
         12 . The composition of  claim 11 , where the at least one phosphite is selected from the group consisting of a triphenyl phosphite, a diphenylalkyl phosphite, a phenyldialkyl phosphite, tris-(nonylphenyl)-phosphite, triauryl phosphite, trioctadecyl phosphite, distearyl-pentaerythrite diphosphite, tris-(2,4-di-tert-butylphenyl)-phosphite, diisodecylpentaerythrite-diphosphite, bis-(2,4-di-tert-butylphenyl)-pentaerythrite diphosphite, bis-(2,6-di-tert-butyl-4-methylphenyl)-pentaerythrite diphosphite, bis-isodecyloxy-pentaerythrite diphosphite, bis-(2,4-di-tert-butyl-6-methylphenyl)-pentaerythrite diphosphite, bis-(2,4,6-tri-tert-butylphenyl)-pentaerythrite diphosphite, tristearyl-sorbit-triphosphite, bis-(2,4-di-tert-butyl-6-methylphenyl)-methyl phosphite, bis-(2,4-di-tert-butyl-6-methylphenyl)-ethyl phosphite, and combinations thereof, and
 wherein the at least one phosphonite is selected from the group consisting of tetrakis-(2,4-di-tert-butylphenyl)-4,4′-biphenylene-diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz[d,g]-1,3,2-dioxaphosphocine, 6-fluoro-2,4,8,10-tetra-tert-butly-12-methyl-dibenz[d,g]-1,3,2-dioxaphosphocine, and combinations thereof.