Polyolefin compositions stabilized against degradation using hydroxylamine derivatives

A composition, stabilized against discoloration, which comprises

• (a) a saturated polyolefin or mixture thereof,
• (b) a stabilizing amount of an alkaline metal salt of a fatty acid, or mixture thereof,
• (c) a stabilizing amount of a phenolic antioxidant, or mixture thereof, selected from the group consisting of
• n-octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, neopentanetetrayl tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), di-n-octadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, thiodiethylene bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), 1,3,5-trimethyl-2,4-6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 3,6-di-oxaoctamethylene bis(3-methyl-5-tert-butyl-4-hydroxyhydrocinnamate), 2,6-di-tert-butyl-p-cr esol, 2,2'-ethylidene-bis(4,6-di-tert-butylphenol), 1,3,5-tris(2,6-dimethyl-4-tert-butyl-3-hydroxybenzyl)isocyanurate, 1,1,3-tris-(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-tris-[2-(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyloxy)-ethyl]isocyan urate, 3,5-di-(3,5-di-tert-butyl-4-hydroxybenzyl)mesitol, hexamethylene bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), 1-(3,5-di-tert-butyl-4-hydroxyanilino)-3,5-di(octylthio)-s-triazine, N,N'-hexamethylene-bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamamide), calcium bis(ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate), ethylene bis[3,3-di(3-tert-butyl-4-hydroxyphenyl)butyrate], octyl 3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate, bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazide, and N,N'-bis[2-(3,5-tert-butyl-4-hydroxyhydroxocinnamoyloxy)ethyl]oxamide, and
• (d) a stabilizing amount of a hydroxylamine derivative, or mixture thereof, of formula II to XIV ##STR14## wherein R is hydrogen or methyl,
• n is 1 or 2,
• R.sub.1 is hydroxyl,
• when n is 1,
• R.sub.2 is hydrogen, C.sub.1 -C.sub.18 alkyl optionally interrupted by one or more oxygen atoms, cyanoethyl, benzyl, glycidyl, a monovalent acyl radical of an aliphatic, cycloaliphatic, araliphatic or aromatic carboxylic acid, or of carbamic acid or of a phosphorus-containing acid, or a monovalent silyl radical, or
• when n is 2,
• R.sub.2 is C.sub.1 -C.sub.12 alkylene, C.sub.4 -C.sub.12 alkenylene, xylylene, a divalent acyl radical of an aliphatic, cycloaliphatic, araliphatic or aromatic dicarboxylic acid, of a dicarbamic acid or of a phosphorus-containing acid, or a divalent silyl radical;
• p is 1,2 or 3,
• R.sub.3 is hydrogen, C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.7 cycloalkyl, C.sub.7 -C.sub.8 aralkyl, C.sub.2 -C.sub.18 alkanoyl, C.sub.3 -C.sub.5 alkenoyl or benzoyl;
• when p is 1,
• R.sub.4 is hydrogen, C.sub.1 -C.sub.18 alkyl, C.sub.5 -C.sub.7 cycloalkyl, C.sub.2 -C.sub.8 alkenyl unsubstituted or substituted by a cyano, carbonyl or carbamide group, or it is glycidyl, a group of the formula --CH.sub.2 --CH(OH)--Z or of the formula --CONH--Z wherein Z is hydrogen, methyl or phenyl;
• or
• when p is 2,
• R.sub.4 is C.sub.2 -C.sub.12 alkylene, C.sub.6 -C.sub.12 arylene, xylylene, a --CH.sub.2 --CH(OH)--CH.sub.2 group, or a group --CH.sub.2 --CH(OH)--CH.sub.2 --O--X--O--CH.sub.2 --CH(OH)--CH.sub.2 -- wherein X is C.sub.2 -C.sub.10 alkylene, C.sub.6 -C.sub.15 arylene or C.sub.6 -C.sub.12 cycloalkylene;
• or, provided that R.sub.3 is not alkanoyl, alkenoyl or benzoyl, R.sub.4 can also be a divalent acyl radical of an aliphatic, cycloaliphatic or aromatic dicarboxylic acid or dicarbamic acid, or can be the group --CO--;
• or R.sub.3 and R.sub.4 together when p is 1 can be the cyclic acyl radical of an aliphatic or aromatic 1,2- or 1,3-dicarboxylic acid;
• or
• R.sub.4 is ##STR15## where T.sub.8 and T.sub.9 are independently hydrogen, alkyl of 1 to 18 carbon atoms, or T.sub.8 and T.sub.9 together are alkylene of 4 to 6 carbon atoms, or 3-oxapentamethylene,
• when p is 3,
• R.sub.4 is 2,4,6-triazinyl,
• when n is 1,
• R.sub.5 is C.sub.2 -C.sub.8 alkylene or hydroxylalkylene or C.sub.4 -C.sub.22 acyloxyalkylene;
• or
• when n is 2,
• R.sub.5 is (--CH.sub.2).sub.2 C(CH.sub.2 --).sub.2 ;
• R.sub.6 is hydrogen, C.sub.1 -C.sub.12 alkyl, allyl, benzyl, glycidyl or C.sub.2 -C.sub.6 alkoxyalkyl;
• when n is 1
• R.sub.7 is hydrogen, C.sub.1 -C.sub.12 alkyl, C.sub.3 -C.sub.5 alkenyl, C.sub.7 -C.sub.9 aralkyl, C.sub.5 -C.sub.7 cycloalkyl, C.sub.2 -C.sub.4 hydroxyalkyl, C.sub.2 -C.sub.6 alkoxyalkyl, C.sub.6 -C.sub.10 aryl, glycidyl, a group of the formula --(CH.sub.2).sub.m --COO--Q or of the formula --(CH.sub.2).sub.m --O--CO--Q wherein m is 1 or 2, and Q is C.sub.1 -C.sub.4 alkyl or phenyl;
• or
• when n is 2,
• R.sub.7 is C.sub.2 -C.sub.12 alkylene, C.sub.6 -C.sub.12 arylene, a group --CH.sub.2 CH(OH)--CH.sub.2 --O--X--O--CH.sub.2 --CH(OH)--CH.sub.2 -- wherein X is C.sub.2 -C.sub.10 alkylene, C.sub.6 -C.sub.15 arylene or C.sub.6 -C.sub.12 cycloalkylene, or a group --CH.sub.2 CH(OZ')CH.sub.2 --(OCH.sub.2 --CH(OZ')CH.sub.2).sub.2 -- wherein Z' is hydrogen, C.sub.1 -C.sub.18 alkyl, allyl, benzyl, C.sub.2 -C.sub.12 alkanoyl or benzoyl;
• Q.sub.1 is --N(R.sub.8)-- or --O--;
• E is C.sub.1 -C.sub.3 alkylene, the group --CH.sub.2 --CH(R.sub.9)--O-- wherein R.sub.9 is hydrogen, methyl or phenyl, the group --(CH.sub.2).sub.3 --NH-- or a direct bond;
• R.sub.10 is hydrogen or C.sub.1 -C.sub.18 alkyl, R.sub.8 is hydrogen, C.sub.1 -C.sub.18 alkyl, C.sub.5 -C.sub.7 cycloalkyl, C.sub.7 -C.sub.12 aralkyl, cyanoethyl, C.sub.6 -C.sub.10 aryl, the group --CH.sub.2 --CH(R.sub.9)--OH wherein R.sub.9 has the meaning defined above;
• a group of the formula ##STR16## or a group of the formula ##STR17## wherein G can be C.sub.2 -C.sub.6 alkylene or C.sub.6 -C.sub.12 arylene;
• or R.sub.8 is a group --E--CO--NH--CH.sub.2 --OR.sub.10 ;
• Formula VII denotes a recurring structural unit of a polymer where T.sub.3 is ethylene or 1,2-propylene, or is the repeating structural unit derived from an alpha-olefin copolymer with an alkyl acrylate or methacrylate;
• and where k is 2 to 100;
• T.sub.4 has the same meaning as R.sub.4 when p is 1 or 2,
• T.sub.5 is methyl,
• T.sub.6 is methyl or ethyl, or T.sub.5 and T.sub.6 together are tetramethylene or pentamethylene or mixture of said hydroxyamine derivatives;
• M and Y are independently methylene or carbonyl;
• L denotes straight or branched chain alkylene of 4 to 7 carbon atoms, 3-oxapentamethylene or 3-hydroxyazapentamethylene;
• T.sub.7 is the same as R.sub.7,
• T.sub.10 and T.sub.11 are independently alkylene of 2 to 12 carbon atoms, or T.sub.11 is ##STR18## T.sub.12 is ##STR19## where a, b and c are independently 2 or 3, and d is 0 or 1;
• and e is 3 or 4;
• and
• T.sub.13 is the same as R.sub.2 with the proviso that T.sub.13 cannot be hydrogen when n is 1.