JPS6055558B2 - Low temperature lubricant - Google Patents

Description

[Detailed description of the invention] This invention relates to low temperature lubricants.

Conventionally, various petroleum fractions have been used as lubricants.
For example, lubricants derived from petroleum, commonly referred to as mineral oils, may be satisfactory for normal applications, but are unsatisfactory for jet engine or polar applications.
Therefore, it has been proposed to improve properties such as viscosity and pour point using synthetic lubricants such as diesters. However, these lubricants are often relatively expensive, and while diesters may be used satisfactorily as jet engine lubricants, they are unsatisfactory as crankcase lubricants. This is due to poor oxidation stability and partial hydrolysis which corrodes copper-lead bearings. Therefore, diesters are not used as low temperature crankcase lubricants. Alkaryl hydrocarbon lubricants with better properties than mineral oil are also known, for example U.S. Pat. Nos. 3,288,716 and 3,173,965
Disclosed in No.

Although these synthetic lubricants are cheaper than diester lubricants, they are more expensive than mineral oils and have lower oxidative stability than mineral oils. The purpose of this invention is to provide a lubricant that can be used satisfactorily in terms of oxidation resistance, fluidity, etc. even at low temperatures.

That is, the present invention provides a lubricant characterized by comprising an alkaryl hydrocarbon lubricant and a synergistically effective amount of mineral oil in the range of about 10 to 10 parts by weight per 10 parts by weight of the lubricant. . The inventors have succeeded in producing a suitable synergistic effect as a low temperature lubricant by appropriately mixing an alkaryl hydrocarbon lubricant with mineral oil.
1 synergistic effect in this specification. By appropriate amount is meant an amount such that when mineral oil is added to an alkaryl hydrocarbon lubricant, the mixture produces improved properties as compared to the properties of these mixtures alone. For example, 75% alkaryl hydrocarbon lubricant and 25% pale oil;
The oxidative stability of the composition is superior to that of alkaryl hydrocarbon synthetic lubricants or pale oil.
In this case, it can be said that the appropriate amount of pale oil for a synergistic effect is 1 part J of the above synthetic lubricant.
The appropriate amount for this synergistic effect varies depending on the raw materials used and the desired properties.

The present inventors have thus discovered that the combination of many mineral oils and alkaryl hydrocarbon synthetic lubricants provides a synergistic effect that is effective in reducing at least oxidation stability and pour point.

The alkaryl hydrocarbon lubricant used in this invention consists primarily of di-normal long chain alkaryl and a small amount of trialkyl-substituted tetrahydronaphthalene, which forms an important element.

Di-normal long-chain alkaryl has about 6 long-chain alkyl groups.
It has from about 10 to 18 carbon atoms, preferably from about 10 to about 14 carbon atoms, and more preferably from about 11 to 14 carbon atoms.

As the allyl group, a phenyl group, tolyl group or xyl group is suitable, and a phenyl group is particularly preferred. Preferred di-normal long-chain alkaryls are therefore di-n-alkylbenzenes in which the alkyl groups correspond to the range of long-chain alkyl groups described above. In this specification, Rn-alkylbenzene has a substantially linear alkyl group, and preferably at least 95% or more of the alkyl substituents are benzene cleaved via the second carbon atom of each alkyl group. It refers to something that is connected to. This Rn-alkylbenzene is synonymous with linear alkylbenzene or linear alkylbenzene. Trialkyl-substituted tetrahydronaphthalene is represented by the structural formula below.

wherein R1 and R2 each have 1 to about 13 carbon atoms, and R1 and R2 together have about 6 to 14 carbon atoms;
, R3 and R4 each have from 1 to about 16 carbon atoms, and the sum of R3 and R is from about 9 to 17.

Furthermore, these alkyl groups R1, R2, R3 and R4 are straight chain. This trialkyl-substituted tetrahydronaphthalene has a boiling point as high as that of di-n-alkylbenzene, and also has a molecular weight that is approximately the same. In addition to the di-n-long chain alkaryl and trialkyl-substituted tetrahydronaphthalenes, hydrocarbon alkaryl synthetic lubricants may contain small amounts of various alkyl aromatic compounds. The hydrocarbon alkaryl synthetic lubricant has the following composition.

A synthetic lubricant having this composition has the following properties.

Hydrocarbon alkaryl synthetic lubricants can be made in a variety of ways.

Examples include a method in which benzene and tetrahydronaphthalene are alkylated and the resulting product is then stirred and mixed, and a method in which a mixture of mono n-alkylbenzene and dialkyl-substituted tetrahydronaphthalene is alkylated using a suitable alkylating agent. . However, a particularly preferred method for producing a hydrocarbon alkaryl synthetic lubricant is to homogenize a mono-n-alkylbenzene-enriched feedstock using species-BF, aluminum bromide, or aluminum chloride as a catalyst. The method for producing a hydrocarbon synthetic lubricant by the above-mentioned disproportionation will be described in detail below, and a composition having the above-mentioned composition and physical properties can be suitably used in the present invention.

Suitable mono n-alkylbenzenes are those having about 6 to about 9 carbon atoms in the alkyl group.

More preferably, mono n-alkylbenzenes in which the alkyl group has about 10 to 15 carbon atoms are used. Suitable materials for obtaining the product by the disproportionation method described above contain a significant amount of mono n-alkylbenzenes falling within the ranges described above and are obtained by the method described in U.S. Pat. No. 3,316,294. It is something that

According to this U.S. patent, a method for making a detergent includes (a) a fraction of substantially linear q-Cl8 hydrocarbons substantially free of olefins, and a non-linear process of the above-mentioned linear hydrocarbons; a step of separating from a petroleum fraction containing chain hydrocarbons;
) chlorinating the hydrocarbon fraction separated in (a) above to substantially monochlorinate about 10 to 35 mol% of linear hydrocarbons; and (C) aromatic compounds such as benzene. in the presence of an alkylation catalyst together with the chlorinated product obtained in step (b) above, and (recovering a fraction consisting essentially of mono n-alkylbenzene by distillation from the reactant in step (d). No. 3,316,294 relates to a process using C8 to Ci8 hydrocarbons, whereas the present invention uses hydrocarbons having about 6 to 18 carbon atoms.
8 to Cl8 hydrocarbons can be obtained by modification of step (a) of the above-mentioned US patent. Other methods for obtaining C6 to Cl8 hydrocarbon fractions may be carried out as appropriate by known means. It is noted that it is preferred to use alkylbenzenes having 10 to 15 carbon atoms in the alkyl group, but this selection can be made either in the initial feedstock or during the distillation of the alkylbenzene product. Next, the conditions for the disproportionation reaction will be described.

The disproportionation reaction is preferably carried out using aluminum chloride as catalyst.

The amount of catalyst is about 0.1 to 10% by weight, more preferably about 0.5% by weight, based on the mono n-alkylbenzene starting material.
to 5% by weight. Optionally, proton donors are used as reaction promoters together with aluminum chloride catalysts.

Suitable promoters of this type include any promoter that produces protons when added to the catalyst. Particularly preferred accelerators are hydrogen chloride and water. A typical loading of this promoter is about 4% by weight of the catalyst. The need for accelerators and the amount to be added can be readily determined by those skilled in the art. The disproportionation reaction is preferably carried out at about 20°C.
It is carried out at temperatures between 130°C and 130°C. Maximum production of di-n-alkylbenzenes is obtained at temperatures between about 65 DEG and 120 DEG C., so temperatures in this range are preferred. After the reaction, the reactants are distilled to remove benzene, paraffin and unreacted mono n-alkylbenzene. The preferred product is a temperature of about 165°C to 30°C, 5wj
．． Distilled under pressure of Hf. This product has an average molecular weight ranging from about 350 to 470. The lower limit of the more preferable temperature in distillation is 185 mHf,
More preferably, the lower limit is 19'Rcl5mlH
Do this with f. In some cases, a preferred fraction is obtained by distillation from the disproportionated product to obtain a selected fraction or an overhead fraction of about 10 to 90% of the disproportionated product. As is well known, mineral lubricating oil is a substance obtained by refining crude oil.

Examples of particularly preferred mineral lubricating oils are pale oil, naphthenic oil and bright stock. When refining petroleum, crude oil is distilled to produce straight-run gasoline, kerosene, and light oil.

The remaining crude oil residue is used to make lubricating oil. Naphthenic oils and pale oils are distillates, and brightstock is a residual oil. Traditionally, veil oils and brightstocks are further processed to decolorize and reduce their wax content. Although pale oils and naphthenic oils are both distillate oils, they differ in many ways.

For example, the chemical composition and physical properties vary depending on the type of crude oil from which they are produced. Naphthenic oil contains a large amount of aromatics, has a low viscosity index, and has a lower pour point than pale oil. Pale oil and naphthenic oil can be easily distinguished by viscosity index and pour point.
As outlined above, bright stock is a highly viscous, solvent-refined product obtained from paraffinic crude oil. Dewaxing lubricant.

Naphthenic oils are suitable for the present invention.

The reason for this is that they often have a synergistic effect.
In particular, the influence of naphthenic oils on the pour point of lubricating oil mixtures is significant over a wide range of composition ratios. Regarding the mineral lubricating oil suitable for the present invention, RPetrOleun
l-PrehistOrictOPetfOchemi
cals” (author, G.A.Plxdy.COppCl
225-22 &. 231, 23
No. 4,242 and No. 37.

Hereinafter, in this invention, preferred ranges corresponding to appropriate amounts of synergistic effects with respect to various properties will be shown for various mineral lubricating oils.

In the above table, 1 part refers to 1 part of hydrocarbon synthetic lubricant.
) section.

As mentioned above, the lubricating oil composition obtained according to the present invention is suitable for obtaining a grease composition for low temperatures.

Also, although the lubricating oil composition according to the present invention provides synergistic effects with respect to various properties, certain properties (particularly viscosity index) are not improved. That is, certain properties (particularly the viscosity index) are intermediate between alkaryl hydrocarbon synthetic lubricants and mineral lubricants. Although many of the compositions within the scope of this invention have lower viscosity index than alkaryl hydrocarbon synthetic lubricants, they still have relatively good viscosity index. The lubricant according to the present invention is effective not only for producing low-temperature grease but also as crankcase lubricating oil and hydraulic fluid.

Next, the case of forming a grease composition in the present invention will be explained. That is, in this invention, conventionally known grease forming agents can be used as appropriate.
As is well known, most commercially available greases use metallic soaps obtained by saponifying fats and oils obtained from animals, plants, or marine products. Other materials suitable for saponification are rosin oil, naphthenic acids, sulfonic acids, synthetic fatty acids, montan wax, and wool grease. Grease forming agent metals include aluminum, barium, calcium, lithium, sodium, magnesium,
Lead or strontium. In addition, various chemically or physically modified clays have also been used as grease formers.

Examples of suitable clays used as such modified and grease formers include bentonite, saponite,
Attapulguide, zeolite and Fraas earth. Among the modified clays, modified bentonite is preferred as a grease former. 1 modified bentonite, which is believed to be well known to those skilled in the art, is described in R Manufac
tureandAppllcatiOnOfLnbri
No. 7 of cating Greases J (written by C.J. BOner, ReinhOld, NewYOrkl954)
Also described on pages 24 and 725.

Preferred grease formers for use in this invention are modified clays, particularly modified bentonites and lithium fatty acid soaps.

Modified bentonite is preferred as a grease forming agent when it is desired to obtain a low viscosity grease composition at cryogenic temperatures (i.e., -50 to -65'F).

Since the lubricating oil compositions of this invention can be used as base oils for the manufacture of greases, the amount of grease formers to be added will be apparent to those skilled in the art. However, to further supplement this, the amount of the grease forming agent used in the grease according to the present invention is in the range of about 1 to 1 part, more preferably in the range of about 5 to 11 parts, per 10 CB of the lubricating oil composition. It is. As is well known, the durability of a grease product is influenced by the amount of grease forming agent added. The grease composition according to the present invention may contain various other additives such as rust inhibitors, antioxidants, lubricants,
There is no problem in adding extreme pressure agents, viscosity agents, etc.

``When obtaining the grease composition according to the present invention, the appropriate amount of pale oil or naphthenic oil for synergistic effect is 10 to 10 parts, preferably 25 to 67 parts, per 100 parts of the alkaryl hydrocarbon synthetic lubricant.

Mixtures of alkaryl hydrocarbons and naphthenic or pale oils with modified bentonite as a grease former are suitable when it is desired to obtain a grease composition with good flow properties at cryogenic temperatures (i.e. -50 to -67F).

Alternatively, when it is desired to obtain a grease composition having good flow characteristics at temperatures between -20 and -40 DEG F., a mixture of an alkaryl hydrocarbon and a naphthenic or pale oil with a lithium fatty acid soap is used. As is clear from the apparent viscosity shown in the Examples below, the grease according to the invention can be pumped even at temperatures as low as -67F.

Because of this low viscosity, it can be handled even at low temperatures without using a normal hand gun. Examples will be described below, and the following substances were used in Examples 1 and 2.

(a) Alkaryl hydrocarbon synthetic lubricant The alkaryl hydrocarbon synthetic lubricant is disclosed in the above-mentioned U.S. Patent No. 3.
obtained based on the method of No. 316294.
Obtained by disproportionation of an alkylbenzene fraction.

This mono n-alkylbenzene had primarily Cl3 alkyl groups. This product had the following composition. Frog 1'1U 1V 4-
μJv●vThe components of this composition have a molecular weight of 442 to 4.
It was in the range of 70.

The physical properties of this composition were as follows.

(1) Naphthenic oil (c) Pale oil and bright stock Example 1 Mixtures containing hydrocarbon synthetic lubricants, naphthenic lubricating oils and pale oils in various proportions were prepared, and the pour point and viscosity index of each was measured.

(1)...Hydrogenated Example 2 This example examines the effect on oxidation stability of mixing 100 pale oil, naphthenic oil A, or bright stock with a hydrocarbon synthetic lubricant. show.

This test is based on the US Federal Standards Test (FederalTest).
MethOdStandard)NO. 79l-B1 test method NO. 53O &, 6 (as of January 15th, 196th year)
It was carried out according to.

However, no metal catalyst was used. Tests were conducted on the following compositions. Table 9 (A) 100% Hydrocarbon synthetic lubricant (1) 100% 100 Pale oil (C) 100% Naphthenic oil A (D) 75% Hydrocarbon synthetic lubricant 25% 100 Pale oil (E) 75% Hydrocarbon Synthetic lubricant 25% Naphthenic oil A (H) 50% Hydrocarbon synthetic lubricant 50% 100 Pale oil (G) 50% Hydrocarbon synthetic lubricant 50% Naphthenic oil A (H) 75% Hydrocarbon synthetic lubricant 25% Bright Stock (RI) 50% Hydrocarbon Synthetic Lubricant 50% Pliner Stock test results are shown in the table below.

Arrow: slightly different, but substantially the same The following materials were used in Examples 3 and 4 described below.

(a) Alkaryl hydrocarbon synthetic lubricant The alkaryl hydrocarbon synthetic lubricant is disclosed in the above-mentioned U.S. Patent No. 3.
It was obtained by disproportionation of a mono n-alkylbenzene fraction obtained according to the method of No. 316294.

This mono n-alkylbenzene had primarily Cl3 alkyl groups. This product had the following composition. The components of this composition ranged in molecular weight from 442 to 470. The physical properties of this composition were as follows.

(B) mineral lubricant *...Generally called 80 pale oil.

Example 3 This example illustrates the effect on the low temperature viscosity of greases obtained by mixing synthetic hydrocarbons with pale or naphthenic oils.

The grease of this example used modified bentonite 66NYK0N7T (manufactured by NatiOnal Ad Co., Ltd.) as a thickening agent, and further added a small amount of sodium nitrite as a rust inhibitor. The grease further contained small amounts of conventional grease additives such as antioxidants, oil film enhancers, etc. in addition to grease formers and lubricating oils. The apparatus used in this example consisted of a 20 foot long coiled copper tube immersed in a freezing bath with an internal diameter of 0.3154 inches.

This 20 foot carp has a length of 24 feet and an inner diameter (
A precooling coil consisting of inch copper tubing was connected. A variable speed gear pump (1 gallon/hour) was attached between the grease reservoir and the pre-cooling coil. A pressure gauge was attached to the junction of the precool coil gate and the 20 foot test coil.
This gear pump enforced air pressure by applying air pressure to the grease reservoir area to prevent cavitation.
This pressure did not affect the grease flow rate of the positive displacement gear pump. The grease flow rate (1 cubic inch/min) per pressure drop per test pipe hood was obtained. Apparent viscosity was obtained using Boiseuille's law. Obtaining grease flow data in this manner is common practice and is described in detail in ASTM Test D-1092. Data on composition, penetration and viscosity of various greases are shown in the table below.

// Example 4 This example describes a grease using a lithium fatty acid soap as the thickening agent and a mixture of a synthetic hydrocarbon lubricant and naphthenic oil as the base oil.

This example shows that a grease containing up to 40% naphthenic oil has the same or slightly better viscosity characteristics than a grease containing 100% synthetic hydrocarbon lubricant. Lithium 12-oxystearate and also naphthenic oil A were used as grease formers.

As in Example 3, a small amount of grease additive was also used. Data on the composition, penetration, and viscosity of the grease are shown below.

Claims (1)

[Scope of Claims] 1. A low-temperature lubricant used at low temperatures below -40°F, comprising an alkaryl hydrocarbon lubricant and about 10 to 1 part by weight per 100 parts by weight of the alkaryl hydrocarbon lubricant.
00 parts by weight of mineral oils selected from pale oils, naphthenic oils and bright stocks; about 61 to 92% by weight of atoms having an aryl group of phenyl, tolyl, or xyl group;
and about 5 to 30 wt. A low-temperature lubricant characterized by having: 2 A low temperature lubricant used at low temperatures below -40°F, comprising an alkaryl hydrocarbon lubricant and about 10 to 1 part by weight per 100 parts by weight of the alkaryl hydrocarbon lubricant.
00 parts by weight of a mineral oil selected from pale oil, naphthenic oil and bright stock; and about 1 to 43 parts by weight of a grease former based on a total of 100 parts by weight of the alkaryl hydrocarbon lubricant oil and the mineral oil. Consisting of
The alkaryl hydrocarbon lubricant is a di-normal long chain alkaryl, in which the long chain alkyl group has about 6 to 18 carbon atoms and the aryl group is a phenyl group, tolyl group, or xylyl group. about 61 to 92% by weight of trialkyl-substituted tetrahydronaphthalene and about 5 to 30% by weight of trialkyl-substituted tetrahydronaphthalene, wherein the alkaryl hydrocarbon lubricant has the following characteristics: a viscosity index of 80 to 1;
16. A low temperature lubricant having a pour point (°F) of -40 to -60 and a molecular weight of about 350 to 526.