Synergistic mixture

A synergistic mixture, comprising:

• (A) from 50 to 95% by weight of a compound having a structural element which is
• (A2) a polycyclic phenolic compound comprising up to 20 benzene rings per molecule, obtained by reacting
• (a2-i) a tetrahydrobenzoxazine of formula (XXVI)
• wherein
• substituent R19 is a hydrocarbyl radical comprising from 1 to 3000 carbon atoms and may be interrupted by one or more heteroatoms from the group of O and S and/or by one or more NR24 moieties,
• R24 is a hydrogen atom or a C1- to C4-alkyl radical, and
• R20, R21, R22, and R23 are each independently hydrogen atoms, hydroxyl groups, or hydrocarbyl radicals comprising in each case from 1 to 3000 carbon atoms and may be interrupted by one or more heteroatoms from the group of O and S and/or by one or more NR24 moieties,
• with at least one of
• (a2-ii) one or more of the same or different phenols of formula (XXVII)
• wherein
• R25, R26, R27, and R28 are each independently hydrogen atoms, hydroxyl groups, or hydrocarbyl radicals comprising in each case from 1 to 3000 carbon atoms and may be interrupted by one or more heteroatoms from the group of O and S and/or by one or more NR24 moieties,
• and
• (a2-iii) one or more of the same or different tetrahydrobenzoxazines of formula (XXVI) wherein R22 may also be a radical of the formula (Z″) and R27 may also be a radical of the formula (Z′″)
• wherein
• R25 may also be a radical derived from a tetrahydrobenzoxazine of formula (XXVI),
• R33 is hydrogen or a radical derived from a tetrahydrobenzoxazine of formula (XXVI), and
• R29 and R30 may be the same or different and are each hydrogen or a C1- to C10-alkyl radical, and
• R20 and R21 or R21 and R22 or R22 and R23 may also form a second tetrahydrooxazine ring with the —O—CH2—NR31—CH2— substructure attatched to the benzene ring, or
• R20and R21 and R22 and R23 may also form a second and third tetrahydrooxazine ring with the —O—CH2—NR31—CH2— and —O—CH2—NR32—CH2— substructures attetched to the benzene ring, where R31 and R32 are each independently hydrocarbyl radicals comprising in each case from 1 to 3000 carbon atoms and may be interrupted by one or more heteroatoms from the group of O and S and/or by one or more NR24 moieties,
• with the proviso that at least one of R19, R20, R21, R22, R23, R25, R26, R27, R28, R31, and R32comprises from 13 to 3000 carbon atoms and the remaining substituents from the group of R19, R20, R21, R22, R23, R25, R26, R27, R28, R31, and R32, when they are hydrocarbyl radicals, comprise in each case from 1 to 20 carbon atoms;
• (B) from 5 to 50% by weight of at least one sulfur containing organic compound with antioxidant activity selected from the group consisting of 2-mercaptobenzthiazole, 2-mercaptobenzimidazole, mercaptotriazine, C4- to C30-alkanethiol, thio glycol, di-C4- to C30-alkyl sulfide, bis(aralkyl) sulfide, bis(aralkyl) disulfide, di-C4- to C30-alkyl disulfide, di(C4- to C30-alkyl) 3,3′-thiopropionate, tetrakis[methylene-2-(C4- to C30-alkylthio) propionate]methane, C4- to C30-alkylthiopropylamide, thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis(C4- to C30-alkylthiomethyl)-6-methylphenol, hydroxyl-containing diaryl sulfide, zinc salt of dialkyldithiocarbamic acid, zinc dialkyldithiophosphate, and a reaction product of terpene, resin oil or low molecular weight polybutenes with sulfur or thiophenol,
• (C) from 0.1 to 5% by weight of at least one sulfur free antioxidant that is a substituted phenol derivative, an arylamine, or a p-phenylenediamine,
• where a sum of the concentrations of the three components (A), (B), and (C) adds up to 100% by weight.