An oxidizable diene rubber contains as an antiozonant a mixture of ring alkylated diphenyl - para - phenylenediamines melting below 80 DEG C. prepared by reacting in the presence of a condensation catalyst (a) a compound selected from the group consisting of hydroquinone and ring-alkylated hydroquinones, and (b) per mol. of compound from group (a) an amine mixture selected from the group consisting of 2.0 to 2.5 mols. of mixed xylidines; 1.0 to 1.25 mols. mixed toluidines and 1.0 to 1.25 mols. mixed xylidines; 1.0 to 1.25 mols. 2,4-dimethyl aniline and 1.0 to 1.25 mols. ortho-toluidine; 1.0 to 1.25 mols. mixed toluidines, 0.7 to 1.0 mol. of mixed xylidines and 0.1 to 0.5 mol. of aniline; 1.0 to 1.25 mols. of mixed xylidines and 1.0 to 1.25 mols. of ortho-ethyl aniline; 1.0 to 1.25 mols. of ortho-ethyl aniline and 1.0 to 1.25 mols. of aniline; 1.0 to 1.25 mols. of ortho toluidine and 1.0 to 1.25 mols. ortho-ethyl aniline; 2.0 to 2.5 mols. of dodecyl anilines; 1.0 to 1.25 mols. of mixed toluidines and 1.0 to 1.25 mols. of amyl anilines; 1.0 to 1.25 mols. of mixed toluidines and 1.0 to 1.25 mols. of dodecylanilines; 1.0 to 1.25 mols. of mixed toluidines, 0.5 to 0.625 mol. of aniline and 0.5 to 0.625 mol. of mixed xylidines; 1.0 to 1.25 mols. of mixed toluidines, 0.5 to 0.625 mol. of amyl anilines, and 0.5 to 0.625 mol. of 2,6-diethyl aniline; 1.0 to 1.25 mols. of mixed toluidines and 1.0 to 1.25 mols. of ortho-ethyl aniline; 1.0 to 1.25 mols. of mixed toluidines, 0.5 to 0.625 mol. of 2,6-diethyl aniline and 0.5 to 0.625 mol. of ortho-ethyl aniline; 1.0 to 1.25 mols. of mixed toluidines, 0.5 to 0.625 mol. of amyl aniline and 0.5 to 0.625 mol. of ortho-ethyl aniline; 1.0 to 1.25 mols. of mixed xylidines and 1.0 to 1.25 mols. of aniline; 1.0 to 1.25 mols. of aniline, 0.5 to 0.625 mol. of 2,6-diethyl aniline and 0.5 to 0.625 mol. of ortho-ethyl aniline; 1.0 to 1.25 mols. of mixed cumidines and 1.0 to 1.25 mols. of mixed toluidines; 2.0 to 2.5 mols. of mixed cumidines. The ring alkylated diphenyl-para-phenylene-diamine may be prepared by reacting (a) a compound selected from the group consisting of hydroquinone and ring alkylated hydroquinone and, (b) per mol. of compound from group (a) an amine mixture consisting of from 2.0 to 2.5 mols. of mixed xylidines, or (b) per mol. of compound from group (a) an amine mixture consisting of from 1.0 to 1.25 mols. of mixed toluidine, 0.7 to 1.0 mols. of mixed xylidines and 0.1 to 0.5 mols. of aniline, or (b) per mol. of compound from group (a) an amine mixture consisting of from 2.0 to 2.5 mols. of mixed cumidines, or (b) per mol. of compound from group (a) an amine mixture consisting of from 1.0 to 1.25 mols. of mixed cumidines and from 1.0 to 1.25 mols. of mixed toluidines. Specified rubbers are natural rubber polychloroprene, as 1,4-polyisoprene, as 1,4-polybutadiene, butadiene-styrene, and butyl rubber.ALSO:An antizonant comprises a mixture of ring alkylated diphenyl - para - phenylenediamines melting below 80 DEG C. prepared by reacting in the presence of a condensation catalyst (a) a compound selected from the group consisting of hydroquinone and ring-alkylated hydroquinones and (b) per mol of compound from group (a) an amine mixture selected from the group consisting of 2.0 to 2.5 mols of mixed xylidines; 1.0 to 1.25 mols mixed toluidines and 1.0 to 1.25 mols mixed xylidines; 1.0 to 1.25 mols 2,4-dimethyl aniline and 1.0 to 1.25 mols ortho-toluidine; 1.0 to 1.25 mols mixed toluidines, 0.7 to 1.0 mol of mixed xylidines and 0.1 to 0.5 mol of aniline; 1.0 to 1.25 mols of mixed xylidines and 1.0 to 1.25 mols of ortho-ethyl aniline; 1.0 to 1.25 mols of ortho-ethyl aniline and 1.0 to 1.25 mols of aniline; 1.0 to 1.25 mols of ortho toluidine and 1.0 to 1.25 mols ortho-ethyl aniline; 2.0 to 2.5 mols of dodecyl anilines; 1.0 to 1.25 mols of mixed toluidines and 1.0 to 1.25 mols of amyl anilines; 1.0 to 1.25 mols of mixed toluidines and 1.0 to 1.25 mols of dodecylanilines; 1.0 to 1.25 mols of mixed toluidines, 0.5 to 0.625 mol of aniline and 0.5 to 0.625 mol of mixed xylidines; 1.0 to 1.25 mols of mixed toluidines, 0.5 to 0.625 mol of amyl anilines, and 0.5 to 0.625 mol of 2,6-diethyl aniline; 1.0 to 1.25 mols of mixed toluidines and 1.0 to 1.25 mols of ortho-ethyl aniline; 1.0 to 1.25 mols of mixed toluidines, 0.5 to 0.625 mol of 2,6-diethyl aniline and 0.5 to 0.625 mol of ortho-ethyl aniline; 1.0 to 1.25 mols of mixed toluidines, 0.5 to 0.625 mol of amyl aniline and 0.5 to 0.625 mol of ortho-ethyl aniline; 1.0 to 1.25 mols of mixed xylidines and 1.0 to 1.25 mols of aniline; 1.0 to 1.25 mols of aniline, 0.5 to 0.625 mol of 2,6-diethyl aniline and 0.5 to 0.625 mol of ortho-ethyl aniline; 1.0 to 1.25 mols. of mixed cumidines and 1.0 to 1.25 mols of mixed toluidines; 2.0 to 2.5 mols of mixed cumidines. The ring alkylated diphenyl-paraphenylene-diamine may be prepared by reaching (a) a compound selected from the group consisting of hydroquinone and ring alkylated hydroquinone and, (b) per mol of compound from group (a) and an amine mixture consisting of from 2.0 to 2.5 mols of mixed xylidines, or (b) per mol of compound from group (a) an amine mixture consisting of from 1.0 to 1.25 mols of mixed toluidine, 0.7 to 1.0 mols of mixed xylidines and 0.1 to 0.5 mols of aniline, or (b) per mol of compound from group (a) an amine mixture consisting of from 2.0 to 2.5 mols of mixed cumidines, or (b) per mol of compound from group (a) an amine mixture consisting of from 1.0 to 1.25 mols of mixed cumidines and from 1.0 to 1.25 mols of mixed toluidines.