Patent GB-496972-A (GB)
Title: Improvements in and relating to age resisters
IPC: C08K11/00
Filed: 1937-06-29
Abstract: The resistance of rubber to deterioration with age is increased by the addition to the mix of the product obtained by the interaction of a secondary arylamine on the reaction product of a primary aromatic amine and a ketone.  The amount of ketone employed in the reaction is always in excess of one molecule for p  each molecule of primary aromatic amine.  The preferred method of reacting the ketone with the amine is to conduct the operation in an autoclave or on the water bath at a temperature of from 50-150 DEG  C. for a period of from five to forty hours.  The ketone-anil so produced is subsequently reacted at a somewhat higher temperature, e.g. 250-300 DEG  C., with the secondary amine to produce a complex mixture of unknown constitution which is the anti-oxidant.  Primary amines mentioned include aniline, toluidine, xylidine, cumidine alpha- and betanaphthylamines, anisidine and phenetidine.  Ketones mentioned include acetone, diacetone alcohol, mesityl oxide, methyl ethyl ketone, acetophenone and cyclohexanone.  Secondary aryl amines mentioned include diphenylamine, phenyl tolylamine, phenyl-alpha- and beta-naphthylamines, diphenyl-p-phenylene diamine and phenyl cumyl amine.  In examples: (1) acetone and alphanaphthylamine are refluxed in the presence of iodine to produce acetone-alpha-naphthil, which is then heated in an autoclave at 250-295 DEG  C. with diphenylamine. The product may be used directly as an antioxidant or it may be separated by distillation into two fractions, each of which possesses anti-oxidant activity.  (2) Acetone and aniline are refluxed, and the product is heated with phenyl beta-naphthylamine in the presence of iodine.  (3) Acetone-anil prepared as in example (1) is heated in the presence of iodine with diphenylamine.  (4) Acetone-anil prepared as in example (1) is heated in the presence of iodine with sym. diphenyl-p-phenylene-diamine.  (5) Acetone is refluxed with p-toluidine, and the product heated in the presence of iodine and calcium chloride with phenyl beta-naphthylamine.  Examples are given to show the efficiency of the accelerators of the invention when incorporated in a standard rubber mix.  The term rubber includes balata, synthetic rubber and reclaimed rubber.  The anti-oxidants may, in addition to being used for rubber, also be used to retard the oxidation of other unsaturated organic compounds such as gasoline and vegetable oils.ALSO:The resistance of rubber to deterioration with age is increased by the addition to the mix of the product obtained by the interaction of a secondary arylamine on the reaction product of a primary aromatic amine and a ketone.  The amount of ketone employed in the reaction is always in excess of one molecule for each molecule of primary aromatic amine.  The preferred method of reacting the ketone with the amine is to conduct the operation in an autoclave or on the water bath at a temperature of from 50-150 DEG  C., for a period of from 5-40 hours.  The ketone-anil so produced is subsequently reacted at a somewhat higher temperature, e.g. 250-300 DEG  C. with the secondary amine to produce a complex mixture of unknown constitution which is the anti-oxidant.  Primary amines mentioned include aniline, toluidine, xylidine, cumidine, alpha and beta naphthylamines, anisidine and phenetidine.  Ketones mentioned include acetone, diacetone alcohol, mesityl oxide, methyl ethyl ketone, acetophenone and cyclohexanone.  Secondary aryl amines mentioned include diphenylamine, phenyl tolylamine, phenyl alpha and beta naphthylamines, diphenyl-p-phenylene diamine, and phenyl amyl amine.  In examples: (1) acetone and alpha naphthylamines are refluxed in the presence of iodine to produce acetone alpha naphthil, which is then heated in an autoclave at 250-295 DEG  C. with diphenylamine.  The product may be used directly as an anti-oxidant, or it may be separated by distillation into two fractions each of which possess anti-oxidant activity; (2) acetone and aniline are refluxed and the product is heated with phenyl beta naphthylamine in the presence of iodine; (3) acetone-anil prepared as in example (1) is heated in the presence of iodine with diphenylamine; (4) acetone-anil prepared as in example (1) is heated in the presence of iodine with sym. diphenyl-p-phenylene diamine; (5) acetone is refluxed with p-toluidine and the product heated in the presence of iodine and calcium chloride with phenyl beta naphthylamine.  Examples are given to show the efficiency of the accelerators of the invention when incorporated in a standard rubber mix.  The term rubber includes balata, synthetic rubber and reclaimed rubber.  The anti-oxidants may, in addition to being used for rubber, also be used to retard the oxidation of other unsaturated organic compounds such as gasoline and vegetable oils.