DE1271879B - Lubricating oil - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

. ClOm

German class: 23 c-1/01

Number: 1271 879

File number: P 12 71 879.5-43 (C 27169)

Filing date: June 5, 1962

Open date: 4th July 1968

It is already known to use low-lubricating oil alkylphenols

at least one sec. or tert. Alkyl radical in o-position to the hydroxyl group as an antioxidant in Use lubricating oils.

It has now been found that the antioxidant effect can be significantly improved if a lubricating oil containing an alkylphenol, an additional 0.3 to 2.0 percent by weight of benzal-cyclohexylamine admixed.

The benzal-cyclohexylamine additive not only acts as a corrosion inhibitor in the lubricating oil, but also also as a slurry dispersant. It is used with advantage in the cylinder oils of marine engines used where it is used as a dispersant and / or as an inhibitor of coating formation on pistons as well is effective as an anti-wear agent.

The alkylphenol has the general formula:

OH

20th

wherein Ri is a branched Cs-Cs-alkyl group without Hydrogen atoms on the carbon atom with the benzene nucleus, R2, R3 and R4 are hydrogen or methyl groups or Ri, and X are hydrogen or R2 or one of the two groups

R ₃ R ₄
• CH ₂ - \ ~~ V ~ ^0H

Applicant:

Castrol Limited, London

Representative:

Dipl.-Chem. Dr. W. J. Berg

and Dipl.-Ing. O. Stapf, patent attorneys, 8000 Munich 2, Hilblestr. 20th

Named as inventor:

John Scotchford Elliott, London

Claimed priority:
Great Britain dated June 8, 1961 (20 819), dated May 15, 1962

Examples

o-isopropyl-phenol,
2,4-dimethyl-6-t-butyl-phenol, 2,6-di-t-butyl-4-methyl-phenol, 2,6-di-t-butyl-phenol,

l, l-bis (3,5-di-t-butyl-4-hydroxyphenyl) methane,

3,3 ', 5,5'-tetra-t-butyl-4,4'-dihydroxydiphenyl, 3-methyl-4,6-di-t-butyl-phenol, 4-methyl-2-t-butyl-phenol ,
4,4'-bis (2,6-di-t-butyl-phenol).

OH

R ₂ R ₁

Preferred are compounds in which Ri = Ri.

The alkylphenol is used in amounts of 0.25 to 2.0, preferably 0.3 to 1.0 percent by weight

and benzal-cyclohexylamine in amounts of 0.3 to 2.0, preferably 0.5 to 1.0 percent by weight, based

each based on the weight of the lubricating oil.

A preferred mixture consists of 0.5 percent by weight Benzal-cyclohexylamine and 0.3 to 0.5 weight percent methylene-bis- (2,6-di-t-butylphenol).

809 568/504

Comparative examples

Institute of Petroleum Standard Method 114/56 T (modified)

Dry air is introduced into a reaction flask containing oil and a copper catalyst for 300 hours. The flask and its contents are immersed in a suitable oil bath, which is maintained at 110 ⁰ C. The acidity and the demulsification value of the oxidized oil were determined after cooling.

Institute of Petroleum Standard Method 19/61,

Demulsification number

20 are emulsified with steam at about 90 ⁰ C ml of the oil. The emulsion is then turned into a

The bath was brought to approximately 94 ° C and the time taken for 20 ml of oil to separate was recorded.

Institute of Petroleum Standard Method 177/62 T
Total acid number

The oil sample is in a mixture of toluene and isopropyl alcohol, which contains water, dissolved and is titrated potentiometrically with alcoholic potash to pH 11.

A mineral oil is a mixture consisting of a solvent purified mineral oil of viscosity of from about 164.6 SUS at 6O ⁰ C and 12% of a solvent-purified bright stocks viscosity of about 684 SUS at 6O ⁰ C is 88%.

Tables I and II show that there is a synergistic effect when alkylphenol is used together and benzal-cyclohexylamine occurs within the claimed additional amounts.

Table I.

Modified IP 114/56 T oxidation test, Additives present (%) Benzal-cyclohexylamine 300 hours be ι HO ⁰ C Mineral oil A Methylene-bis- (2,6-di-t-butyl-
phenol) 0.5 mixture nothing 1.0 Try on oxidized oils No. nothing 0.5 Acidity Demulsification value 1 0.2 0.25 1.39 1200+ 2 0.25 0.5 > 3.0 1200+ 3 0.25 nothing 0.24 1200+ 4th 0.3 0.1 1.12 1200 • 5 0.3 0.2 0.08 780 6th 0.3 0.5 0.73 1200 7th 0.3 0.7 0.89 1200 8th 0.3 nothing 0.67 1200 9 0.5 0.3 0.39 750, 630 10 0.5 0.5 0.34 660 11 0.5 nothing 0.86 1200 12th 1.0 0.5 0.13 540 13th 1.0 1.0 0.39 600 14th 2.0 0.45 1200 15th 0.17 840 16. 0.15 1200

Table II

Modified IP 114/56 T oxidation test, 300 hours at HO ⁰ C

Mineral oil A

mixture Existing additives Benzal-cyclohexylamine Experiments on oxidized oils Demulsification value No. Phenolic additives 1.0 Acidity 1200 1 nothing 0.5 3.0 420 2 0.5% 2,6-di-t-butyl 0.44 4-methyl-phenol nothing 1200 3- 1.0 "/ o the same. 0.5 0.55 720 4- 0.5% 4,4'-bis (2,6-di-t-butyl-
ohenoD nothing 0.48 1200 5 1.0% same .0.5 0.33 600 6th 0.5% 2,6-di-t-butyl-phenol 0.45

Claims (1)

5 6 τ,. u group, characterized in that Claim: _{it zusätz} i _I benzal-cyclohexylamine contains. Lubricating oil containing an alkylphenol with publications under consideration: at least one secondary or tertiary 5 British Patent No. 824,405; Alkyl ortho to Hydroxyl U.S. Patent No. 3,018,248. X »561/504 6.68 © Bundesdruckerei Berlin