DE1091684B - Lubricating oil - Google Patents

Description

GERMAN

It is known to use a mixture of an oil-soluble one as a rust-preventing additive mixture for petroleum hydrocarbons acidic alkyl phosphoric acid ester having 3 to 20 carbon atoms in each alkyl group and an alkyl mercaptoacetic acid with 6 to 20 carbon atoms in the alkyl radical to be used (German Patent 964 649). as For this purpose, alkyl mercaptoacetic acids are preferably straight-chain compounds, such as lauryl mercaptoacetic acid, used.

Furthermore, from US Pat. No. 2,493,483 Use of a glyoxalidine derivative mixed with an alkali or alkaline earth sulfonate and a partial ester a polyhydric alcohol and a higher fatty acid as well as a fatty oil as a rust preventive additive Known lubricating oils.

US Pat. No. 2,491,066 describes a rust inhibitor for mineral oils consisting of an alkyl mercaptoacetic acid having 10 to 30, preferably 12 to 22 carbon atoms in the alkyl group and one oil soluble petroleum sulfonate. Such additional combinations are very effective rust inhibitors, but they work in the presence of water as a strong emulsifier, which is extremely important for their use in marine turbine oils is disadvantageous.

The invention relates to a lubricating oil mixture which is a novel combination of two components contains, which gives the oil surprising rust-inhibiting properties and is different from the additional combination according to the US Pat. No. 2,491,066 characterized in that in the presence of water does not have an emulsifying effect.

The lubricating oil mixture according to the invention based on a lubricating oil which contains a small proportion of an alkyl mercaptoacetic acid and an alkaline earth metal sulfonate as a rust preventive agent is characterized in that, based on the lubricating oil base, it contains 0.005 to 1.0 percent by weight of a branched-chain C ₉ - to C ₁₇ -Alkylmercaptoacetic acid and a calcium or barium salt of a branched-chain C ₆ - to C ₁₂ -dialkylnaphthalenesulfonic acid.

The alkyl radical of the alkyl mercaptoacetic acid is preferably a strongly branched-chain radical with at least three branched groups, in particular such a radical with 13 carbon atoms. As a SuIfonat preferably a branched chain dinonyl naphthalene sulfonate is used.

The two additional ingredients can, for. B. in the lubricating oil in amounts of 0.007 to 0.50 percent by weight each, based on the lubricating oil base.

The sulfonate is preferably a calcium salt. These rust-inhibiting combination is particularly effective when used in proportions of 3.0 to 0.3 parts by weight of the branched chain alkyl mercaptoacetic acid each

Applicant:

Esso Research and Engineering Company, Elizabeth, N.J. (V. St. A.)

Representative: E. Maemecke, Berlin-Lichterfelde West,
to and Dr. W. Kühl, Hamburg 36, Esplanade 36 a,

Patent attorneys

Claimed priority:

V. St. v. America November 26, 1957
15th

Ernest V. Wilson, Cranford, N.J.,

Henry R. Ertelt, Fanwood, N.J.,

and Williard H. Keeber, Westfield, N. J. (V. St. A.),

have been named as inventors

Part by weight of the alkaline earth metal dialkylnaphthalene sulfonate is used.

According to a further embodiment of the invention, the lubricating oil mixture contains as a further component an oil-soluble zinc dialkyldithiophosphate known per se as a lubricating oil additive with alkyl groups from 2 to 18 carbon atoms in amounts from 0.05 to 2.0 percent by weight.

The mercaptoacetic acid used in the context of the invention has the formula:

RS-CH ₂ -COOH,

in which R is a branched-chain alkyl group with 9 to 17 carbon atoms. According to a preferred embodiment according to the invention, R is highly branched. "Highly branched" is understood to mean an alkyl radical which at least three branched groups or side groups and one or more carbon atoms as side chains contains.

The naphthalene sulfonates used according to the invention are characterized in that they are used in the Concentrations not stabilizing on emulsions and in some cases even as a de-emulsifying agent works. This means that they are formed according to the standardized demulsifiability test (ASTM D1401)

Resistant emulsions do not favor oils that contain this Containing naphthalene sulfonates meet the requirements of the standard MIL-L-17 331A (for ships) on marine turbine oils, namely the formation of a maximum foam sleeve

009 629/391

(lacy cuff) of 3 ecm in 30 minutes. The two alkyl groups of the alkylnaphthalene sulfonate can be in various positions on the rings and are branched-chain radicals with 6 to 12 carbon atoms each.

As lubricating oils, all known oils with lubricating oil properties including animal, vegetable, synthetic and mineral oils are used, the latter being preferred. Preferably has the Oil base has a viscosity in the range from 3.2 to 32 cSt at 98.8 ° C, a flash point of more than 188 ° C Pour point below -3.9 ° C and a specific gravity in the range from 0.8984 to 0.855.

Examples of suitable synthetic oils are diesters such as di-2-ethylhexyl sebacate, complex esters such as the reaction products of 2 parts of di-2-ethylhexanol, 2 parts of a dicarboxylic acid and 1 part of polyethylene glycol with an average molecular weight of 200, silicone oils such as polydimethylsiloxane, which is produced by hydrolytic condensation of dimethyldichlorosilane, phosphorus derivatives such as C ₈ -oxo-diphenyl phosphate and the like.

The lubricating oil mixture according to the invention can also contain normal lubricating oil additives in the usual proportions included to give it certain properties. These additives are known per se and include Viscosity index improvers, pour point depressants, extreme pressure agents, oxidation retardants, foam inhibitors and the like

example 1

The base oil comes from a mid-continent crude and is made by extraction with phenol, dewaxing refined with methyl ethyl ketone and treating with active earth.

It has the following characteristics:

Viscosity at 98.8 ° C, cSt 10.1

Viscosity at 37.8 ⁰ C, cSt 85.3

Viscosity index 107

Flash point, ⁰ C 251.7

Pour point, ⁰ C -6.7

Color (day, Robinson) 13 ¹ no ₂

Coking residue according to Conradson,

Weight percent 0.02

Neutralization number, mg K O H / g <0.01

Saponification value 0.07

Sulphated ash, weight percent ... <0.001

Sulfur, weight percent 0.22

The additives are C ₁₃ -oxo-mercaptoacetic acid and barium dinonylnaphthalene sulfonate. The alkyl radicals of mercaptoacetic acid are derived from C ₁₃ -oxo alcohol, which is produced from tetrapropylene according to the known oxo synthesis. The C ₁₃ oxo alcohol can be converted in a known manner in C ₁₃ -oxo-mercaptoacetic acid by reacting it with hydrogen bromide at 125 ⁰ C with the bromide, is washed out from the product with sulfuric acid the unreacted alcohol, washed acid-free with water, and the bromide with an alkali hydrosulfide, such as sodium or potassium hydrosulfide, converted into the corresponding C ^ -oxomercaptan, which is then further reacted with monochloroacetic acid. The alkyl radical has an average of four branched groups. If necessary, hydrogen chloride or zinc chloride can be used in place of the hydrogen bromide, in which case the corresponding chloride is obtained, which is then reacted further as described above.

The barium dinonylnaphthalene sulfonate is in a manner known per se by alkylating naphthalene with highly branched nonenes, e.g. B. tripropylene,

Sulphonating the dinonylnaphthalene in an inert organic solvent with oleum or sulfuric acid and reaction of dinonylnaphthalenesulfonic acid with barium carbonate.

Oil solutions are prepared and according to the rust test MIL-L-17331A examined. This test corresponds to the ASTM seawater rust test (test standard ASTM D 665) and is carried out after washing the oil sample at 90 ° C for 30 minutes with distilled water (as stated in the test standard MIL-L-17 33IA [for ships] is prescribed).

The results are shown in Table I.

Table I.

Heavily branched Barium salt of Rust test
according to MIL-L-17331 A chain
C ₁₃ -Mercapto-
acetic acid (C ₉ ) ₂ -nap-
thalin
sulfonic acid Weight percent Weight percent insufficient (60% rust) 0.04 0 insufficient (20% rust) 0 0.025 insufficient (20% rust) 0 0.05 sufficient (no rust) 0.015 0.0075 insufficient (3% rust) 0.01125 0.01125 insufficient (5% rust) 0.0075 0.015 sufficient (no rust) 0.025 0.0125

Table I shows that even with a surprisingly small amount of each of the two ingredients in Combination achieves an effective rust inhibition. The combination of these small amounts has an equally good one or better effect than much larger amounts of each of the two ingredients on their own. the according to the fifth and sixth example of Table I.

Oil mixtures composed according to the invention do not meet the particularly strict requirements of USA.-Army standard, but still show in comparison

a considerably improved effect with the oil mixtures of the first three examples.

Example 2

The same base oil as in Example 1 is used. There are samples with a content of 0.35 percent by weight Zinc dialkyldithiophosphate (in which the alkyl groups are from a mixture of about 25 percent by weight isopropyl alcohol and about 75 percent by weight methyl isobutyl carbinol are derived), to test the effectiveness of the rust-inhibiting combination.

The results are given in Table II.

Table II

Heavily branched Barium salt of chain (Cj) ₂ -NaPh- Mercapto thalin acetic acid sulfonic acid (C ₁₃ -OxO - SCH ₃ COOH), Weight percent Weight percent 0 0.04 0 0.06 0.05 O 0.10 O 0.125 O 0.05 0.02

Rust test according to MIL-L-17331 A

insufficient (2% rust) insufficient (1% rust) insufficient (10% rust) insufficient (< 1% rust) is sufficient (no rust) is sufficient (no rust)

* This addition is the mercaptoacetic acid used in Example 1.
** This addition is the sulfonate used in Example 1.

Table II shows that the combination of mercaptoacetic acid and sulfonate of the present invention is equally effective The anti-rust effect also results from a content of zinc thiophosphate additives in the oils. Furthermore, one can see from the Table that the combination has a good rust-inhibiting effect at relatively low total concentrations of rust inhibitors and low free acid content. The better anti-rust effect of the Mixtures according to Examples 1, 2 and 4 of Table II in comparison with the mixtures according to Examples 5 and 6 of Table I is explained by the further addition of the zinc dialkyldithiophosphate, which in the mixtures according to Table I is not included. When comparing Examples 5 and 6 of Table II, it should be noted that that a perfect rust preventive effect in the presence of the zinc dialkyldithiophosphate with omission of the Mercaptoacetic acid requires a concentration of 0.125 percent by weight of barium sulfonate, while at simultaneous addition of barium sulfonate and mercaptoacetic acid a total concentration of these two Additions of 0.07 percent by weight are sufficient to achieve a complete anti-rust effect. If if the inhibitors are added in excess for safety reasons, the combination is advantageous Adaptability for the production of oil mixtures, so that other important requirements for the Condition, e.g. B. low ash content and low neutralization number can be met.

Example 3

Three lubricating oil mixtures are produced. The lubricating oil base corresponds to that of Example 1. Sample Number 1 contains 0.5 percent by weight of zinc dialkyldithiophosphate according to Example 2 and 0.5 percent by weight highly alkaline synthetic barium sulfonate, a commercial detergent for petroleum products by sulfonating the bottoms of an alkylation process. Sample # 2 contains 0.5 percent by weight of the same zinc dialkyldithiophosphate and 0.5 percent by weight of strongly alkaline barium dinonylnaphthalene sulfonate. Sample No. 3 contains 0.5 weight percent of the same zinc dialkyldithiophosphate and 0.5 weight percent neutral barium dinonyl naphthalene sulfonate.

Sample number 1 therefore contains a sulfonate as described in US Pat. No. 2,491,066, while samples 2 and 3 contain the dialkylnaphthalene sulfonates to be used according to the invention.

The samples are made after the above-mentioned de-emulsifiability test ASTMD-1401 examined, the following results are obtained:

Sample 1:

After 60 minutes, persistent, cream-like emulsions, Volume 50 ecm. Is not enough.

Sample 2:

After 30 minutes, foam cuff of 3 ecm; enough.

Sample 3:

No emulsion (0.0 ecm) after 5 minutes.

The data show that the petroleum sulfonates described in U.S. Patent 2,491,066 are emulsion-forming act, while the sulfonates used according to the invention have an emulsion-destroying effect. The sulfonates of the combinations known from the United States patent are therefore unsuitable for purposes in which the lowest possible emulsion formation is important.

60 In order to show the interaction between the rust-inhibiting constituents, the threshold value of effectiveness is determined experimentally using low limit concentrations. In practical use, however, it is advantageous to work with concentrations of the rust inhibitors that leave a certain margin for safety and also ensure a rust protection effect if part of the rust inhibitor has been lost through precipitation on metal surfaces or through very slow leaching from the oil with water . The following examples explain finished oil mixtures which contain the combination of rust inhibitors according to the invention in concentrations suitable for technical purposes.

Example 4

A ship sturbin en high pressure oil is made from a paraffinic one Oil made from a midcontinent crude oil by distillation, extraction with phenol, dewaxing with methyl ethyl ketone and treatment with active soil has been obtained.

This base oil has the same physical characteristics, which are given in Example 1.

The following ingredients are added to the base oil: 0.35 percent by weight zinc dialkyldithiophosphate according to Example 2; 0.05 weight percent barium dinonylnaphthalene sulfonate (as a 50 ° / ₀ sodium concentrate in a Coastal oil), prepared according to Example 1; 0.03 percent by weight of C ₁₃ -oxo-mercaptoacetic acid, prepared according to Example 1; 0.0005 percent by weight silicone oil as anti-foaming agent (viscosity 350 cSt at 25 ° C).

The finished oil mixture has the following characteristics:

Viscosity at 98.9 ° C. CSt 10

Viscosity at 37.8 ° C, cSt 86.2

Viscosity index 104.5

Pour point, ⁰ C -6.7

Neutralization Number (ASTM D974) 0.81

Seawater rust test (MIL-L-

17331A) is sufficient, no

rust
Resistance to oxidation

(ASTM D943), hours 1000

Emulsion test (ASTM D 1401)

[maximum foam cuff

(lacy cuff) after 25 minutes = 3 ecm] is sufficient
Mineral acidity

(MIL-L-17331A) neutral

Corrosion of stripes (ASTM D 130)

[3 hours at 100 ^° C.] 1 (a)

Coking residue according to Conrad-

son (ASTM D 189), weight percent 0.16

Sulphated ash, percent by weight. 0.14

Color (day, Robinson) 13 ^x / ₄

Mean load according to Hertz

(VV-L-791, 6503), kg 35.2

Ryder Gear Test (MIL-L-17331A) .. 3310 lbs / inch

(591 kg / cm)
Wear test in the four-ball device

(15 kg; 8O ⁰ C; 600 rpm; 2 hours),

Scratch diameter 0.27 mm

This turbine oil is tested through practical use in a new 38 0001 - Supertanker, which with a composite steam turbine with a nominal output of 26,500 hp. The steam turbine is on articulated main drive gear unit coupled with double reduction. Proven in this test the turbine oil is excellent.

Example 5

A higher viscosity lubricating oil is made using 80 percent by weight of that in Example 1 Base oil with 20 percent by weight of a mid-continent crude oil with propane Deasphalted, dewaxed with methyl ethyl ketone, extracted with phenol and with active soil treated residual oil are mixed. The base oil obtained in this way has a viscosity of 11.6 cSt at 98.9 ° C. This base oil is made with 0.35 percent by weight zinc dialkyldithiophosphate, 0.15 percent by weight Barium dinonylnaphthalene sulfonate and 0.05 percent by weight of C ^ -oxo-mercaptoacetic acid were added. The oil satisfies the seawater rust test according to the test standard ASTM ρ 665.

Similar oils of higher viscosity containing a) 0.05 weight percent sulfonate and 0.03 weight percent Cj ₃ -OXO-SCH ₂ COOH or b) 0.10 weight percent sulfonate and 0.04 weight percent C ₁₃ -OxO-SCH ₂ COOH also meet this rust test.

Claims (5)

Patent claims: 1. Lubricating oil mixture based on a lubricating oil containing a small proportion of an alkyl mercaptoacetic acid and an alkaline earth metal sulfonate, characterized in that it, based on the lubricating oil base, each 0.005 to 1.0 percent by weight of a branched C ₉ - to C ^ -alkyl mercaptoacetic acid and contains a calcium or barium salt of a branched-chain C ₆ - to C ₁₂ -dialkylnaphthalenesulfonic acid. 2. Lubricating oil mixture according to claim 1, characterized in that the alkyl radical of the alkyl mercaptoacetic acid is a highly branched residue with at least three branched groups. 3. Lubricating oil mixture according to claim 1 or 2, characterized in that the mercaptoacetic acid is a highly branched C ₁₃ mercaptoacetic acid and the sulfonate is a branched-chain dinonylnaphthalene sulfonate. 4. lubricating oil mixture according to claim 1 to 3, characterized in that it is the alkyl mercaptoacetic acid and the sulfonate in a proportion of 3 to 0.3 parts by weight of alkyl mercaptoacetic acid contains sulfonate per part by weight. 5. lubricating oil mixture according to claim 1 to 4, characterized in that it is also a Lubricating oil additive known oil-soluble zinc dialkyldithiophosphate with alkyl groups from 2 to Contains 18 carbon atoms in amounts of 0.05 to 2.0 percent by weight. Considered publications:
German Patent No. 964,649;
U.S. Patents No. 2,491,066,2493,483, 2,659,705; 2,643,962;
French patent specification No. 974 374. 1 009 629/391 10.60