DE1035833B - Lubricating oil mixture - Google Patents

Description

The invention relates to mixtures of lubricating oils with additives which give the lubricating oils better wear-reducing properties Give properties and are obtained by fluorination of organically substituted dithiophosphates.

The use of organic dithiophosphates as lubricating oil additives is known per se. These substances will to lubricating oils, such as motor oils, usually in view of their sludge-inhibiting, wear-reducing properties and corrosion-retarding properties added. They are also of value when applying in the crankcase of passenger cars, buses, trucks, etc., where high performance is required.

It has now been found that the wear-reducing properties of the organic lubricating oil additives Dithiophosphates are significantly improved by introducing a small amount of fluorine into the compound permit. As a result of the greater resistance of the fluorine-carbon bonds, this effect can only with fluorine, but not with other halogens such as chlorine. When these compounds are fluorinated so far be that they are about 0.01 to 1.0 percent by weight, preferably 0.05 to 0.5 percent by weight chemically bonded If they contain fluorine, their wear-reducing properties are considerably improved without other valuable properties are adversely affected. The fluorinated additives according to the invention can be used in all cases where the organic dithiophosphates have heretofore been used.

The dithiophosphates used in the context of the invention have the general formula Lubricating oil mixture.

R - o

P-S-

R '- O

-M

in which the radicals R and R 'can be identical or different, each contain 2 to 20 carbon atoms and are selected from the group of aryl, alkyl, aralkyl, cycloalkyl, aryloxyalkyl, acylaryl and alkoxyaryl radicals, M Is hydrogen or a salt-forming metal and η is the valence of M. This class of compounds includes, in particular, the dialkyldithiophosphates, such as dibutyldithiophosphate, dihexyldithiophosphate, di-n-octyldithiophosphate, dicapryldithiophosphate, dilauryldithiophosphate, dioctadecyldithiophosphate, dioctadecyldithiophosphate, etc. in which the dialkyldithiophosphate groups contain one, mean 5 to to ensure adequate solubility of the dithiophosphates in lubricating oils. The diaryldithiophosphates, especially those in which the aryl group is substituted by an alkyl, alkoxy group or a cycloaliphatic group, such as diphenyldithiophosphate, di- (2,4-diamylphenyl) dithiophosphate, applicant:

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

Representative: E. Maemecke, Berlin-Lichterfelde West,

and Dr. W. Kühl, Hamburg 36, Esplanade 36 a

Patent attorneys

Claimed priority:
V. St. v. America June 8, 1956

John O. Smith Jr., North Plainfield, N.J.,

and John V. Clarke Jr., Cranford, N.J. (V. St. A.),

have been named as inventors

Dikerylphenyldithiophosphate (keryl refers to the mixture of hydrocarbon residues derived from luminous oil; the product is produced by reacting chlorinated luminous oil with a phenol in the presence of aluminum chloride and further reaction of the reaction product with P ₂ S ₅ ) and the various diaryldithiophosphates, in which the aryl groups are replaced by wax hydrocarbon residues are substituted. You can also use dicycloaliphatic dithiophosphates, for example those obtained by reacting cyclopentanone, cyclohexanol, cycloheptanol, and methyl, ethyl, propyl and amyl-substituted cyclopentanone, cyclohexanol and cycloheptanol, etc. with P ₂ S ₆ . The diaryl-oxyalkyldithiophosphates, such as di- (2,4-diamylphenoxyethyl) -dithiophosphate, the diacylaryldithiophosphates, such as di- (lauroylphenyl) -dithiophosphate, and the dialkoxyaryldithiophosphates, such as di- (methoxyphenyl) -dithiophosphate, can also be used.

The dialkyl dithiophosphates are preferred because they have a higher pressure absorption capacity, better ones Are inhibitors and sludge dispersants and have a lower viscosity than other dithiophosphates. Those dialkyldithiophosphates in which each alkyl group has 3 to 6 carbon atoms are particularly preferred contains and both groups together contain an average of at least 5 carbon atoms. To these alkyl groups include isopropyl, n-propyl, isobutyl, η-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, tert-pentyl, n-hexyl and 1,4-dimethylbutyl. The two alkyl groups can be the same or different.

809 580/533

3 4

These various organically substituted dithiolent radicals, diesters of dicarboxylic acids, for example ester phosphates, are preferably used in the form of their metal salts of adipic acid or sebacic acid with monovalent ones. The various metal alcohols that can be used, such as hexyl, octyl, 2-ethylhexyl or salts, include those of the salt-forming radicals, such as higher alcohols, esters of polyethylene glycols with iron, nickel, aluminum, cadmium, tin, zinc, 5-branched chain C. ₈ - to C ^ -carboxylic acids, complex magnesium, calcium, strontium, barium, etc. Particularly esters of polybasic acids, polyhydric alcohols, iron, barium and zinc salts, monocarboxylic acids and / or monohydric alcohols are preferred because they are even in a non-fluorinated state as an effective z. B. have proven complex esters with the glycol residue or the dicarsamer. bonsäurerest as a middle piece, phosphoric acid ester or

For the production of the lubricating oil additives, for which no ία-thioester of aliphatic alcohols or mercaptans patent protection is claimed, is used as fluorination with up to 18 carbon atoms, halogenated hydrocarbon oils, medium preferably cobalt trifluoride CoF ₃ , which as for example the polymers of chlorofluoroalkylenes, such as Chlorine mild fluorinating agent works; However, you can also use trifluoroethylene, organic siloxanes, sulphurous acid esters, other mild fluorinating agents, such as silver carbonic acid esters, mercaptals, formals, etc.
difluoride AgF ₂ , manganese fluoride MnF ₃ , lead tetrafluoride 15. You can also add other Zu-PbF ₄ , cerifluoride CeF ₄ , bismuth pentafluoride BiF ₅ , thal- sets, such as viscosity index improvers, eg lium fluoride TlF ₃ , to the lubricating oil mixtures. Polymethacrylic acid esters, copolymers of fumaric

The reaction is made from acid esters and vinyl acetate, copolymers in an inert atmosphere guided. Maleic acid esters and vinyl acetate, polyalkyl styrene

To facilitate the operation, or because the 20 and the like. The viscosity index improvers can be used in quantities Commercially available dithiophosphates usually as from about 0.1 to 30 weight percent, preferably 0.1 Oil concentrates are supplied, the fluo- to 10 percent by weight, in particular 0.1 to 5 percent by weight in the presence of an oil as a diluent percentage, based on the finished lubricating oil mixture, carry out. Suitable diluent oils are paraffin-added. Mixtures of hydrocarbons can also be used, in which the exteriors to be fluorinated use types of viscosity index improvers, The raw material is soluble and its boiling point is above Also a small amount of a pour point depressant

204 ° C, the highest temperature, is at which the fluo- can be added to the finished oil mixture in order to achieve the ration is carried out. To improve the stability of the pour point and the

However, the preparation can also lower the pour point without dilution. Such pour point depressants can be carried out through an oil by making the dithio- 30 are e.g. condensation products of chlorinated wax phosphate directly with the fluorinating agent, with naphthalene or phenol, various polymers puts. and copolymers of unsaturated esters and the like

When carrying out the fluorination reaction, mixed polymer of the fumaric acid ester of coconut oil is allowed to contain about 0.1 to 2.0 mol of the mild fluorinating agent with vinyl acetate in a weight ratio of 80:20, 1 mol of the dithiophosphate is under such conditions, for example in concentrations of about 0.01 up to 5 weight react that about 0.01 to 1.0 weight percent fluorine percent, based on the oil base, effective,
be introduced into the dithiophosphate. Other suitable additives to add to the finished oil

After the reaction has ended, the reaction mixture can be added, oxidation can be diluted with an inert solvent such as hexane, heptane, retarders such as phenothiazine, lauryl selenide, phenyl benzene or toluene, to make the fluorine-40 a-naphthylamine, rust inhibitor such as Separating lecithin, metal product from the insoluble substances, such as CoF ₂ salts of petroleum sulphonic acids or synthetic sulphonic and unreacted CoF ₃ , whereupon the acids, sorbitan monooleate, lauryl mercaptoacetic acid, unreacted substances and impurities are filtered off with sludge inhibitors such as the barium salt of isononyl. The solvent is then evaporated, and it is phenol sulfide, and the calcium salts of petroleum sulfone leaves the purified product. 45 acids or synthetic sulfonic acids, corrosion

As a base oil for the oil-mixed protective agents according to the invention, such as di-2-ethylhexylamine, and others mineral lubricating oils of additives are preferably used.

Viscosity in the range of 1.2 to 216 cSt at 37.8 ° C. This example

Mineral lubricating oils from natural sources can

of any paraffinic or naphthenic raw 50-60 g of a mixture of 55 percent by weight zinc diols derived and refined in a manner known per se (1,4-dimethylbutyl) dithiophosphate and 45 weight percent of a solvent-extracted paraffinic However, the invention is not limited to the use of mineral oil distillates having a viscosity index of 105 and Limited to mineral oils as a base; it can also have a viscosity of 32 cSt at 37.8 ° C as various diluents synthetic oils with viscosities of 55 medium were placed in a nickel beaker, at least 1.2 cSt at 37.8 ° C as an oil base or part. Then 11 g of cobalt trifluoride in powder form were added to the same be used. Examples are used in this way. There was a nitrogen bar above the beaker Synthetic lubricating oils are ether alcohols, e.g. atmosphere, to exclude the air and an oxide one the formula to prevent dative degradation. The mixture was in

60 heated to 193 ° C in a sand bath. At this temperature

RO (C _n H _2n O) ₁ H started the implementation, resulting in the development of

Gas made noticeable from the reaction mixture. That

where R is an alkyl group, η an integer from 2 to 5 reaction mixture was then 2 hours below and χ an integer from 1 to 40, e.g. the stirring was kept at a temperature of 193 ° C, then monobutyl ether of tetradecapropylene glycol, mono- 65 left to cool, the product dissolved in 100 ecm of hexane carboxylic acid ester with 20 to 80 carbon atoms in the molecule, and filtered through filter paper. The hexane, for example the esters of aliphatic C ₄ to C ₁₈ acids, was evaporated off by heating the solution on a steam bath of aliphatic C ₄ to C ₁₈ alcohols or C ₄ to C ₁₈ until the hexane was complete aborted. Residues such as butyl, isobutyl, hexyl, octyl, isooctyl, the product thus obtained consisted of 55 percent by weight of 2-ethylhexyl, nonyl, decyl, lauryl, stearyl and ahn- 70 fluorinated zinc diaikyldithiophosphate and 45 weight percent

percent of the originally present diluent oil. The product appeared slightly darker than the original zinc dialkyldithiophosphate solution and resulted at! the analysis shows a fluorine content of 0.12 percent by weight.

Mixtures were made consisting of 2 percent by weight of this fluorinated product and 98 percent by weight of a paraffinic mineral lubricating oil distillate with a viscosity index of about 100.

Furthermore, mixtures with the non-fluorinated additive were prepared with those just described Mixtures were consistent with the exception that the zinc di (1,4-dimethylbutyl) dithiophosphate is not fluorinated was.

These mixtures were tested in a Shell 4-ball tester examined. The test is carried out as follows:

The lubricating oil to be tested is placed in the machine's cup at room temperature. In this mug there are three steel balls that are held in place by a screwed-on cap. A fourth steel ball, which is held in a chuck, is held against the three lower balls with pressed against a known force and rotated at 1800 revolutions / min. There will be trials of 1 minute each performed at increasingly higher loads, with a new set of for each load Bullets is used. This method is used to determine the maximum load that can be withstood without the metal is sloughed off or the oil film ruptures.

The results of these tests are summarized in the following table:

Table II

Lubricating oil Oxidation test (viscosity, cSt at
37.8 ° C) 12th
hours 16
hours 20th
hours Oil base
+ fluorinated
additive
Oil base
+ not fluo
rated addition .. 8th
hours 118.4
121.1 122.2
125 123.8
127.9 116
119.4

Table I.

Lubricating oil Shell-4-ball-
High pressure test
(Maximum load
in kg) Oil base
oil base + fluorinated additive ..
oil base + non-fluorinated addition
sentence 60
88
68

The mixtures containing the fluorinated and non-fluorinated additives were also tested after the corrosion test investigated for petroleum products by means of the copper strip (ASTM test standard D-130). Both mixtures showed hardly any influence on copper and did not show any noticeable discoloration on the copper strip, what the evaluation · ■ J-2 «according to the mentioned ASTM test standard.

The mixtures were also subjected to an oxidation test carried out as follows:

The oil sample is heated in a glass tube to 171 ⁰ C and subjected to the oxidation by an air current is passed. A copper-lead test bearing mounted on a shaft is rotated in the oil. After a certain period of time, the bearing is removed, polished again and put back into the oil. The viscosity of the oil is determined at the end of each test period. The first period lasts 8 hours and each subsequent 4 hours; the total test duration is 20 hours. The less the increase in viscosity, the better the oil.

The results of the oxidation test are compiled in the table below:

As can be seen from the tables above, the fluorination of the zinc dialkyldithiophosphate increases the pressure absorption capacity the compound is significantly improved without adversely affecting other beneficial properties of this additive. This result was surprising because the fluorination of other substances has no effect on their pressure absorption capacity Has. For example, the diluent oil used in the example was itself fluorinated to the extent that it contained about 0.1 weight percent fluorine. The pressure absorption capacity of this oil was in the 4-ball apparatus according to Shell, 60 kg before fluorination and 58 kg after fluorination. Also the fluorination of others Additives such as a polymerized methacrylic acid ester having a molecular weight of about 20,000, one Polybutylene having a molecular weight of about 20,000, a calcium salt of an oil-soluble sulfonate and a Barium salt of an alkylphenol sulfide had no effect on the pressure absorption capacity of these additives. From Table II it can also be seen that the increase in viscosity of the oil on oxidation by the The presence of the fluorinated dithiophosphate is remarkably reduced.

Claims (5)

Patent claims:
1. Lubricating oil mixture based on a predominant proportion of a lubricating oil, characterized in that it contains about 0.001 to 10.0 percent by weight of a fluorinated organic dithiophosphate with a content of about 0.01 to 1.0 percent by weight of chemically bound fluorine. 2. Lubricating oil mixture based on a predominant proportion of a lubricating oil, characterized in that that it is about 0.01 to 3.0 weight percent of a fluorinated organic dithiophosphate with a content of about 0.05 to 0.5 percent by weight of chemically bound fluorine. 3. Lubricating oil mixture according to claim 2, characterized in that the organic dithiophosphate the general formula R - O, R '-O —S- -M in which the radicals R and R 'each contain 2 to 20 carbon atoms and are selected from the group of aryl, alkyl, aralkyl, cycloalkyl, aryloxyalkyl, acylaryl and alkoxyaryl radicals, M is hydrogen or a salt-binding agent Means metal and η is the valence of M. 4. lubricating oil mixture according to claim 3, characterized in that the organic dithiophosphate is a Is zinc dialkyldithiophosphate. 5. lubricating oil mixture according to claim 4, characterized in that the zinc dialkyldithiophosphate Zinc di (1,4-dimethylbutyl) dithiophosphate with a fluorine content of about 0.1 percent by weight. © 809 580/533 7.58