Synthetic lubricant antioxidant from monosubstituted diphenylamines
AssigneeThe B. F. Goodrich Company
InventorJohn T. Lai
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Abstract
An oligomer from diarylamines is disclosed which has desirable antioxidant properties in lubricating oils which contain synthetic ester lubricants. The oligomer is desirable for use at higher temperatures where it has less volatility than simple diarylamines. The oligomer has substantial portions of monosubstituted diphenylamine repeat units which result in linear oligomers. Di and polysubstituted diphenylamines may optionally be present as repeat units. These di and polysubstituted diphenylamines generally react as monofunctional reactants in oligomerization and tend to reduce the number of repeat units in the average oligomer.
Claims15
An oligomeric reaction product comprising repeat units from a monosubstituted diphenylamine, wherein said monosubstituted diphenylamine before coupling is one or more monosubstituted diphenylamines having the formula ##STR7## where R.sup.1 is independently an alkyl, alkenyl, or aralkyl group having from 1 to 20 carbon atoms,
- wherein said oligomeric reaction product has from about 10 to 100 mole percent of the repeat units from said one or more monosubstituted diphenylamines.
A process for making an antioxidant, comprising;
- reacting a diarylamine solution comprising from about 10 to about 100 mole percent of one or more monosubstituted diphenylamines based on the total diarylamines of said solution;
- said one or more monosubstituted diphenylamines having the formula ##STR9## where R.sup.1 is an alkyl, alkenyl, or aralkyl group having from about 1 to about 20 carbon atoms;
- in a dehydrocondensation reaction to form one or more oligomers.
Dependencies are inferred from the claim text.