JPS5922758B2 - Base oil composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to base oil compositions, such as lubricating oils, transmission fluids or industrial oil compositions, which have improved stability to the short wavelength light typical of sunlight.

In the production of base oil, hydro-processing (hydro-pr
It is known to carry out processing steps such as hydrogenolysis and/or hydrofinishing.

A disadvantage of such hydrotreated oils, particularly hydrocracked base oils, is that they are unstable to sunlight, the short wavelength light characteristic of sunlight.

Exposure of hydrotreated base oils to sunlight usually results in one or more of the following undesirable effects: darkening, haze formation, and sludge formation.

Attempts have been made to overcome this drawback by blending the base oil with a variety of other oils, such as non-hydroprocessed oils, but these other oils are now available in very large quantities, e.g. More must be used and this affects the properties of the base oil.

Attempts have also been made to overcome this drawback by including additives in the hydrotreated base oil.

For example, U.S. Patent No. 3,702,299 discloses the use of orthohydroxybenzophenones and aliphatic primary amines, and U.S. Pat. The use of condensation products is disclosed.

Applicants have now discovered that the sunlight stability of hydrotreated base oils is significantly improved by adding certain quinones to it.

According to the invention, a large portion of the hydrotreated base oil and a small portion of the following general formula: For example, an alkyl group of 01 to C1o is shown, provided that at least three of the R1 groups are tertiary
provided that it is an alkyl group; each R2, which may be the same or different, represents H or a C1-C2o alkyl group, such as an alkyl group of 01-6; and represents an integer of 0 or 1-4. ) A base oil composition is provided, which is characterized by containing a quinone represented by the following.

Preferred compounds of general formula I are those in which each R1 group represents a tertiary alkyl group, especially a 04-C8 tertiary alkyl group, with the tertiary butyl group being the most preferred R1 group.

Also suitable are compounds in which each R2 is H, and R3 is a group of the general formula H or a group of the general formula 3, and n is 0.

The most preferred quinones of general formula I are:
5,5'-tetra-tert-butyl-4,4'-diphenoquinone and 3,3',5,5'-tetra-tert-butyl-4,4'-stilbenequinone, i.e., in general formula I, R3 is A compound of the formula (1), in which each R1 is a tertiary butyl group and each R2 is H, or in the general formula I, R3 is a group in the general formula (2), where n is 0,
each R1 is a tertiary butyl group and each R2 is H
It is a compound that is

The quinones may be prepared by any conventional technique, but are preferably prepared by reacting the 2,6-dialkylphenol or 2,6-dialkylfuresol with an organic or inorganic oxidizing agent.

Suitable oxidizing agents include air, oxygen, benzoyl peroxide, tert-butyl peroxide.

The reaction is usually carried out in a solvent such as chlorobenzene under nitrogen and at an elevated temperature such as 100 DEG to 200 DEG C.

Catalysts such as cuprous chloride and complexes of tertiary amines may be used.

The amount of compound of general formula I that may be added to the hydrotreated base oil may vary within wide limits, but is usually between 0.0001 and 2.0% by weight, based on the weight of the hydrotreated base oil, preferably 0.0001% to 2.0% by weight, based on the weight of the hydrotreated base oil. 001~0.1 weight, more preferably 0.001~
It is 0.05% by weight.

The base oil composition according to the invention may also contain antioxidants.

Suitable antioxidants have the general formula (wherein R4 represents an organic group, R3 represents H or an organic group, and each R
6 represents H or an organic group, which may be the same or different, is an aromatic amine having at least one secondary amine bonded to an aromatic nucleus.

Suitable compounds of the above angle (3) are those in which R4 is a substituted or unsubstituted aliphatic, aromatic or heterocyclic group, R5 is H or the same group as R4, and each R6 is H or an alkyl group, e.g. It is a compound that is a C1 to C6 alkyl group.

Suitably R4 is an alkyl group of 01-2o, for example 01-6
alkyl groups, with secondary alkyl groups such as sec-butyl groups being particularly preferred.

Preferably R5 is the same group as R4 and preferably each R6 is H.

A suitable compound is N,N-di-sec-butyl-p-phenylenediamine.

The amount of antioxidant that may be added to the hydrotreated base oil may vary widely, but typically ranges from 0.0001 to 2.0% by weight, preferably 0.000% by weight, based on the weight of the hydrotreated base oil.
It is 1 to 0.05% by weight.

The advantage of the quinones mentioned above is in particular that, in addition to improving the sunlight stability of the hydrotreated oils, the quinones do not have an adverse effect on the emulsifying properties of the hydrotreated oils.

The present invention is useful for improving the sunlight stability of hydrofinished and/or hydrocracked base oils, and is useful for improving the sunlight stability of hydrofinished and/or hydrocracked base oils. Particularly useful for improving the sunlight stability of base oils.

Hydrotreated oils may be derived from mixtures of hydrocarbons derived from heavy petroleum fractions obtained by pyrolysis of coal, bitumen ciere or cool sands, but are preferably derived from crude oils, e.g. De-asphal-+tea is derived from petroleum fractions or slackwax.

Petroleum fractions that boil at least partially above the boiling range of the lubricating oil are advantageously used.

In general, hydrofinishing is a mild hydrotreating process carried out under conditions that depend on the nature of the feedstock, but typically the feedstock is heated to 150 ml in the presence of a hydrogenation catalyst.
It involves contacting with hydrogen at a temperature of ~350<0>C and a pressure typically between 10 and 200 bar.

The treatment is usually carried out in addition to a conventional solvent extraction step.

Hydrofinishing typically does not increase the viscosity index of the feedstock.

Overall, hydrocracking is a more severe process carried out under conditions that depend on the nature of the feedstock, but typically the feedstock is treated with a hydrogenation catalyst (the same catalyst used in hydrofinishing or (which may be different catalysts) at a temperature of usually 350-500°C and usually 60-500°C.
including contacting with hydrogen at a pressure of 200 bar.

Hydrogenolysis is usually carried out in place of the conventional solvent extraction step.

Hydrocracking typically increases the viscosity index of the feedstock and is used to produce high, very high and exceptionally high viscosity index lubricating base oils.

Generally, when the feedstock is hydrocracking and then hydrofinishing, the conditions for image processing are similar to those described above for hydrocracking, with the exception that The hydrofinishing temperature is at least 25°C below the hydrogenolysis temperature.

The invention is particularly suitable for improving the sunlight stability of hydrotreated base oils having a viscosity index in the range 80-155.

The base oil composition according to the invention also includes a viscosity index improver,
Other additives may also be included, such as anti-wear/extreme strength additives, detergents and pour point depressants.

The invention will be illustrated by the following example.

Examples 1-4 In these experiments, approximately 1], 5cS at 210'F
A lubricating base oil was used that was a hydrocracked and hydrofinished vacuum distillate having a viscosity of 100 t and a viscosity index of about 95.

3.3',5.5'-tetra-tert-butyl-4,4'-diphenoquinone (quinone (:r)) or 3.3',5.5'-tetra-tert-butyl- 4,4'・
-Stilbenequinone (quinone (2)) alone or with N
, I'7-di-sec-butyl-p-phenylenediamine.

Next, artificial sunlight stability tests were conducted on the base oil itself and the base oil composition.

In the test, Pyrex containing oil 301 was used.
x) An ASTM pour point test tube was placed in a compartment maintained at 35±0.5°C.

Next, the test tube was exposed to two fluorescent lights (Phi-1ips TL4
0w157) and the time until any cloudiness or sludge formation was observed in the oil was measured.

The results were as shown in the table below.

Claims (1)

[Scope of Claims] 1 A large amount of hydrotreated base oil and a small amount of the following general formula [wherein R3 is the general formula or (wherein each R1 may be the same or different, H or C1 ~2o alkyl group, provided that at least three of the R1 groups are tertiary alkyl groups; each R2 may be the same or different, but H or C1~
2o alkyl group; and n is 0 or an integer of 1 to 4) A base oil composition comprising a quinone represented by the following.