US2308691A - Lubricating oil - Google Patents

Description

atented Jan. i9 14 LUBRICdG H3 No Drawing. Application November 25, 1940, Serial No. 367,061

Claims.

This invention relates to mineral oils; and it is among the objects of the invention to provide compositions afiording increased stability in service conditions, such as involved in contact with metals, and elevated temperatures, etc.

To the accomplishment ofthe foregoing and related ends, the invention, then, comprises the features hereinafter fully described, and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative however, of but a few of the various ways in which the principle of the invention may be employed.

With the mineral oil, which may be of desired character, for instance 45-200 sec. Saybolt Universal at 210 F., there is incorporated a small amount of an aminodiphenylamine compound. Less than 5 per cent is in general suficient, and usually 0.1 to 1 per cent. The aminodiphenylamine compound maybe an amino diphenylamine per se or derivative. The derivative may have substituents on the nitrogen atoms as well as on the rings. The substituents may be alkyl, aryl, heterocyclic radicals, cycloparafiin, alkylidene, arylidene, acyl, or substituted derivatives of such groups, ashalogen, sulphur, OH, -SH, R--O--, RCO, etc. The substituent on the ring may be any of the above as well as their derivatives. Illustrative of such compounds are t-aminodiphenylamine, Z-aminodiphenylamine,

3 aminodiphenylamine, N-acetyl 2 -'aminodiphenylamine, N-benzyl-2-aminodiphenylamine, t amlnodiphenylamine, N-acetyl 4 aminodiphenylamine, pCi'Is.CeH4.NH.CsI-I4.NH2-p, dimethyl-t-aminodiphenylamine, etc. Very advantageous are sulphur aminodiphenylamines, as for instance R or R being hydrogen, alkyl, aryl, heterocyclic, cycloparamn groups, etc., or their derivatives, illustrated for instance by 4 aminothiodiphenylamine.

As an example: With a commercial S.'A. E. 20 lubricating stock there is incorporated 0.25 per cent of 4-aminodiphenylamine. This product tested by the quick test method involving passing air at the rate of thirty liters per hour through the oil at 300 F. for sixty-five hours, showed a viscosity increase of '71 sec. Saybolt at F., sludge formation 4.4 per cent, lacquer formation 16.2 mg., copper corrosion 0.3, and appearance rating B. In contrast, the oil without the aminodiphenylamine compound, tested under the same conditions, showed a viscosity increase of 258, sludge formation 9.2, lacquer formation 54.6, copper corrosion 6.3, and appearance rating D.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

I therefore particularly point out and distinctit 1y claim as my invention:

1. A beneflciated mineral oil consisting of an oil of lubricating viscosity and a small amount of dimethyl-t-aminodiphenylamine.

2. A beneflciated mineral oil consisting of an oil of lubricating viscosity and a small amount of d-amlnodiphenylamine.

3. A beneflciated mineral oil consisting of an oil of lubricating viscosity and a small amount of 4-aminothiodiphenylamine.

4. A beneflciated mineral oil consisting of an oil of lubricating viscosity and a small amount of a sulphur mono-aminodiphenylamine.

5. A beneflciated mineral oil consisting of an oil of lubricating viscosity and a small amount of a mono-aminodiphenylamine compound.

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