DE1594359C3 - Use of oil-soluble naphthalenes as additives for lubricating oils - Google Patents

Description

The invention relates to improvements in the quality of lubricating oils for hydrofinishing have been subjected.

The refining of lubricating oils obtained from petroleum distillates or deasphalted residues 'usually includes dewaxing to improve the pour point of the oil and one A bleaching earth treatment to improve color and heat and storage stability. Additionally Many lubricating oils are solvent-extracted, for example with furfural or a Treatment with sulfuric acid before the final bleaching earth treatment is subjected to the aromatics content to lower the oil and thereby improve its viscosity index.

The bleaching earth treatment has certain disadvantages, one of which is the problem of elimination of the used bleaching earth, and in recent years has to some extent been replaced by a so-called "hydrofinish treatment" has been replaced. This treatment consists in doing that oil in the presence of hydrogen with a hydrogenation catalyst at temperatures between 150 and 340 ° C and pressures between 5 and 70 atmospheres brings together. The catalyst usually consists of one or more oxides or sulfides of Chromium, molybdenum, tungsten, iron, cobalt or nickel on aluminum oxide as a carrier. One of the better known technical hydrofinishing process is the so-called »ferrofining« (ferrofining is a registered Trademark). This method is described in British patents 9 13 047, 9 13 048 and 9 17 345. The one in the ferrofining process The catalyst used consists of the oxides of molybdenum and iron and possibly cobalt on aluminum oxide as a carrier. The conditions used in the hydrofinish treatment are compared to other processes in which a treatment with hydrogen is carried out, so mild that the viscosity and the viscosity index of the oil are hardly affected.

In general, the hydrofinish treatment enables the production of good lubricating oil base oils most grades from most crude oils.

It has been found that certain types of lubricating oil which are subjected to a hydrofinish treatment if the oils have been left to stand for some time, a slight clouding due to wax forms will. This cloudiness is either visible to the naked eye or, very often, only visible when you let a bright light fall through the liquid. The cloudiness may start out as a veil and then appear in the form of faint "clouds" throughout the liquid. Appears in bottle samples usually with the wax cloud a weak foam at the oil-air-glass interface. The cloudiness deteriorates the appearance of the oil refined by the hydrofinishing treatment as such oil is almost colorless, homogeneous and transparent immediately after production. It has shown, that the haze due to wax in some brightstocks and some distillate oils that are subjected to hydrofinish treatment but not in spindle oils after hydrofinish treatment occurs.

It has now been found that wax opacity in lubricating oils from the hydrofinish treatment prevents or can be eliminated by using oil-soluble monoalkylnaphthalenes, polyalkylnaphthalenes and / or polynaphthylalkanes used in small amounts as inhibitors or distributing agents, expediently in an amount of 0.001 to 0.5 percent by volume, preferably 0.005 to 0.05 percent by volume. Preferably are mono- and / or poly-n-alkylnaphthalenes used.

Although it is already known, alkylnaphthalenes with a quaternary carbon atom on the aromatic Ring made in the presence of Friedel-Craft catalysts have been prepared by alkylation to be used as antioxidants in insulating oils, however could not be foreseen that the above-mentioned monoalkylnaphthalenes, polyalkylnaphthalenes and polynaphthylalkanes or their mixtures would be suitable for the special problem of prevention or removal of wax cloudiness in lubricating oils from the hydrofinish treatment solve.

The inhibitors or distributing agents used according to the invention prevent the formation from the outset of wax opacities or remove wax opacities that are already in the hydrofinish treatment subject lubricating oils refined by any conventional method are present. Possibly the hydrofinish treatment removes inhibitors that are present in the oil and otherwise the haze would be prevented, or by the hydrofinish treatment itself, in some oils possibly small amounts of such opacifying substances are formed. Through the distributing agents used in the present invention will divide the wax particles into a very finely divided one Form transferred.

example

The tendency of samples to become cloudy due to wax was determined by placing samples (1) in a refrigerator at 2.2 to 3.3 ° C and then (2) in a laboratory at room temperature of 10 were stored up to 15.6 ° C. The liquid was

with the naked eye in daylight and in an intense beam of light from a microscope converging lens checked. The results are given in the table below.

Table 1

Diluted lag cruim at 3.3 to 4.4 C

Wax-Haze-Tcst at
4.4 C *)

24 mercenaries 48 hours 72 hours

BG 160/95 control

BG 160/95 + 0.01 volume percent »A«

Observations

Fog formation after! Days at 3.3 ° C. Cloudiness caused by flocculants appears when left to stand at 10 ^° C

Fogging after 2 days at 3.3 ° C. No turbidity visible in normal light at 10 ^{° C}

as indicated for 0.01 volume percent

BG 160/95 + 0.05 volume percent "A"
BG 160/95 + 0.10 volume percent "A"

BG 160/95 + 0.50 volume percent "A"

1. BG 160/95 is a basic one that has been subjected to hydrofinish treatment Lubricating oil with a redwood viscosity of 160 seconds at 60 ° C and a viscosity index of 95.

2. “A” is an inhibitor according to the invention or one according to the invention Distribution agent consisting of a mixture of alkylnaphthalenes and polynaphthylalkanes.

The results in Table 2 below show the inhibitory effect of small amounts of the product "A" on freshly prepared samples of the BG 160/95 oil.

Table 2

Diluted wax haze
Test at
4.4 ° C *)

Storage at 3.3 to 4.4 ° C

24 hours

48 hours

72 hours

Sample of the
from one
Ferrofining plant
expiring product
(untreated)

lighter
veil

lighter
veil

Veil veil

Sample from clear clear clear clear

the pro

product template one
Ferrofining
Factory

(With
0.01 volume per
cent »A«
treated

delt)

*) The Diluted-Wax-Haze-Test consists in that one equal volume of a mixture of toluene and methyl ethyl ketone (50:50) to a sample of the hydrofinish treatment subjected to lubricating oil and then the oil to 60 to 65.6 ° C heated. The solvent accelerates the formation of a wax film.

The effect of the inhibitor “A” on the cloud point and pour point is shown in the table below.

Table 3

35 sample Cloudy floor Point Point PC) PC) 40 BG 160/95 control -5.6 -6.7 BG 160/95 + 0.01 volume -5.6 -6.7 percent "A" BG 160/95 + 0.05 volume -5.6 -6.7 percent "A" ⁴⁵ BG 160/95 + 0.10 volume -6.7 -9.4 percent "A" BG 160/95 + 0.50 volume -6.7 -12.2 percent "A"

The inhibitors or spreading agents used according to the invention suppress the formation of fog, which occurs with some oils after hydrofinishing. The oils remain afterwards clear and bright to the naked eye.

Claims (3)

Patent claims: 1. Use of oil-soluble monoalkylnaphthalenes, polyalkylnaphthalenes and / or polynaphthylalkanes in small amounts as an inhibitor or dispersant to prevent or eliminate of wax cloudiness in lubricating oils from hydrofinish treatment. 2. Use of oil-soluble monoalkylnaphthalenes, polyalkylnaphthalenes and / or polynaphthylalkanes in an amount of 0.001 to 0.5 percent by volume, preferably 0.005 to 0.05 percent by volume, according to claim 1 as an inhibitor or distributing agent for preventing or eliminating of wax cloudiness in lubricating oils from hydrofinish treatment. 3. Use of oil-soluble mono- and / or poly-n-alkylnaphthalenes according to Claims 1 and 2 as an inhibitor or spreading agent to prevent or eliminate wax cloudiness in Lubricating oils from the hydrofinish treatment.