EP0079302A2 - Lubricants containing thio ethers of beta-dicarbonyl or beta-cyano-carbonyl compounds - Google Patents

Abstract

Thioethers of beta -dicarbonyl and/or beta -cyanocarbonyl compounds of the general formula I <IMAGE> are outstandingly suitable as lubricant additives, especially as extreme-pressure additives and antiwear additives, and also as activators of chloroparaffins in metal processing oils. With regard to the definitions of the substituents in formula I reference is made to Claim 1.

Description

The present invention relates to the use of thioethers of β-dicarbonyl or β-cyanocarbonyl compounds for the finishing of lubricants including metal processing oils.

It has been found that thioethers of .beta.-dicarbonyl or .beta.-cyanocarbonyl compounds are outstandingly suitable as lubricant additives, in particular as "extreme pressure" and "antiwear" additives, and as activators (boosters) of chlorinated paraffins in metalworking oils.

Certain thioethers are known as lubricant additives from EP-OS 1 217. However, these are β-substituted epithio compounds and their addition products, which cannot be compared structurally with the thioethers to be used according to the invention.

oder ein Gemisch solcher Verbindungen enthalten, worin R C₁-C₁₂ Alkyl, unsubstituiertes oder durch C₁-C₄ Alkyl, C₁-C₄ Alkoxy oder Halogen substituiertes C₆-C₁₀ Aryl oder eine Gruppe -OR³ ist, R² eine Gruppe -C(O)R⁴ oder ^-CN bedeutet, ^R3 C₁-C₁₂ Alkyl ist, _R ⁴ _R ¹, -NH₂, -NH(R5), -N(R⁵)₂, eine Gruppe -O-(CH₂)_n-S(O)_m-R³, wobei n eine ganze Zahl zwischen 1 und 6 und m Null oder 1 bedeuten, oder eine Gruppe -CH -S-R bedeutet, R⁵ C₁-C₁₂ Alkyl ist und R R oder -CN bedeutet.The present invention accordingly relates to lubricants which, as an additive, are a compound of the formula I.

or contain a mixture of such compounds in which RC ₁ -C ₁₂ alkyl, unsubstituted or substituted by C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy or halogen, is C ₆ -C ₁₀ aryl or a group -OR ³ , R ² represents a group -C (O) R ⁴ or ^-CN , ^{R3 is} C ₁ -C ₁₂ alkyl, _R ⁴ _R ¹ , -NH ₂ , -NH (R5), -N (R ⁵ ) ₂ , a group -O - (CH ₂ ) _n -S (O) _m -R ³ , where n is a integer between 1 and 6 and m are zero or 1, or a group -CH -SR, R ^{5 is} C ₁ -C ₁₂ alkyl and RR or -CN is.

R ¹ , R ³ and R ⁵ are branched or unbranched alkyl as C ₁ -C ₁₂ alkyl, such as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl, α-methyl pentyl, Hexyl, 2,4-dimethylpentyl, octyl, 6-methylheptyl, decyl, dodecyl. R ¹ and R ⁵ are preferably C ₁ -C ₄ alkyl, especially methyl. R ³ is preferably ethyl, tert-butyl, 1,1,3,3-tetramethylbutyl or 1,1,3,3,5,5-hexamethylhexyl.

R ¹ is an unsubstituted C ₆ -C ₁₀ aryl, for example naphthyl or especially phenyl.

As C ₆ -C ₁₀ aryl substituted by C ₁ -C ₄ alkyl, R ^{1 is,} for example, one, two or three times, preferably once in the o- or in particular in the p-position by methyl, ethyl, n-propyl, isopropyl , n-butyl, tert-butyl substituted phenyl.

As C ₆ -C ₁₀ aryl substituted by C ₁ -C ₄ alkoxy, R ^{1 is,} for example, one, two or three times, preferably once in the o- or in particular in the p-position by methoxy, ethoxy, n-propyloxy, Isopropyloxy, n-butoxy or tert-butoxy substituted phenyl.

As a C ₆ -C ₁₀ aryl substituted by halogen, R ^{1 is,} for example, phenyl substituted once, twice or three times, preferably once, in the o- or in particular in the p-position by iodine, bromine or in particular chlorine.

Particularly noteworthy are lubricants which contain, as an additive, a compound of the formula I in which R ^{1 is} C ₁ -C ₄ alkyl, phenyl which is unsubstituted or substituted by C ₁ -C ₄ alkyl, C ₁ -C ₄ alkox or halogen or a group -OR ³ , R is a group -C (O) R ⁴ , R3 _ae t _h y _l , tert-butyl, 1,1,3,3-tetramethylbutyl or 1,1,3,3, 5,5-hexamethylhexyl and R ^{4 is} R ¹ or a group -O-CH ₂ CH ₂ -SR ³ , where R ^{3 has} the meaning already given in this preference.

Preferred are lubricants which contain an additive of a compound of formula 1, in which R ^{1 is} methyl or phenyl and R ^{2 is} a group -C (0) -OC ₂ H ₅ or -C (O) -OCH ₂ CH ₂ -SC ₂ H ₅ means.

The thioethers of the formula I to be used according to the invention are known compounds. If some of them are still new, they can be prepared in analogy to known processes, for example by direct action of SC1 ₂ on β-dicarbonyl compounds of the formula

where R ¹ and R ^{2 have} the meaning given above, for example according to SK Gupta, J.Org.Chem. 39, 1944 (1974) or A. Angeli, F. Magnani, Gazz. 24, 342/364 (1894). Another reaction is the reaction of metalated (for example with sodium) β-cyanocarbonyl compounds with SCl _2. Finally, 2-chloro-ß-ketocarboxylic acid esters or 3-chloro-ß-ketocarboxylic acid esters with H ₂ S in the presence of hydrogen chloride acceptors (NaOH , tertiary amines) in the compounds according to the invention.

The compounds of formula I act in very small amounts in lubricants, in particular as "extreme pressure" and "antiwear" additives and as activators (boosters) of chlorinated paraffins in metalworking oils. Mineral and synthetic lubricating oils, and mixtures thereof, which contain 0.001 to 5% by weight, based on the lubricant, and preferably 0.2-3% by weight of a compound of the formula I or a mixture of such compounds, have excellent lubricating properties especially in strong reduced wear and tear of the friction partners to be lubricated become clear.

The lubricants in question are familiar to the person skilled in the art and e.g. in the "Lubricant Pocket Book" (Hüttig Verlag, Heidelberg, (1974). Mineral oils are particularly suitable. Systems particularly suitable for metal processing ("cutting fluids") are described, for example, in JO Cookson, An introduction to cutting fluids, TRIBOLOGY INTERNATIONAL (February 1977), SS.5-11.

The lubricating oil formulation can additionally contain other additives that are added to improve certain performance properties, such as antioxidants, metal passivators, rust inhibitors, viscosity index improvers, pour point depressants, dispersants / surfactants and other wear protection additives.

Examples of antioxidants are:

• a) alkylated and non-alkylated aromatic amines and mixtures thereof, for example: dioctyldiphenylamine, (2,2,3,3-tetramethylbutyl) phenyl-α- and ß-naphthylamine, phenotriazine, dioctylphenothiazine, phenyl-a-naphthylamine, N, K'-di-sec-butyl-p-phenylenediamine.
• b) Sterically hindered phenols, for example: 2,6-di-tert-butyl-p-cresol, 4,4'-bis (2,6-diisopropylphenol), 2,4,6-triisopropylphenol, 2,2 ' -Thio-bis- (4-methyl-6-tert-butylphenol), 4,4'-methylene-bis- (2,6-di-tert-butylphenol).
• c) alkyl, aryl or alkaryl phosphites, e.g. trinonyl phosphite, triphenyl phosphite, diphenyldecyl phosphite.
• d) esters of thiopropionic acid or thiodiacetic acid, e.g. dilauryl thiodipropionate or dioctyl thiodiacetate.
• e) Salts of carbamic and dithiophosphoric acids, e.g. antimony-diamyldithiocarbamate, zinc-diamyldithiophosphate.
• f) Combination of two or more antioxidants of the above, e.g., an alkylated amine and a sterically hindered phenol.

Examples of metal passivators are: a) for copper, e.g .:

Benzotriazole, tetrahydrobenzotriazole, 2-mercaptobenzotriazole, 2,5-dimercaptothiadiazole, salicylidene-propylenediamine, salts of salicylaminoguanidine.

b) for lead, e.g .:

Sebacic acid derivatives, quinizarin, propyl gallate.

c) Combination of two or more of the above additives. Examples of rust inhibitors are: a) Organic acids, their esters, metal salts and anhydrides, e.g .:

N-oleoyl sarcosine, sorbitan mono-oleate, lead naphthenate, dodecenylsuccinic anhydride.

b) Nitrogen-containing compounds, e.g .:

• I. Primary, secondary or tertiary aliphatic or cycloaliphatic amines and amine salts of organic and inorganic acids, e.g. oil-soluble alkylammonium carboxylates.
• II. Heterocyclic compounds e.g. substituted imidazolines and oxazolines.

c) phosphorus-containing compounds, e.g .:

Amine salts of phosphoric acid partial esters.

d) Sulfur-containing compounds, e.g .:

Barium dinonylnaphthalene sulfonates, calcium petroleum sulfonates.

e) combinations of two or more of the above additives. Examples of viscosity index improvers include:

Polymethacrylates, vinyl pyrrolidone / methacrylate copolymers, polybutenes, olefin copolymers, styrene-acrylate copolymers.

Examples of pour point depressants include:

Polymethacrylates, alkylated naphthalene derivatives.

Examples of dispersants / surfactants include: polybutenylsuccinic acid imides, polybutenylphosphonic acid derivatives, basic magnesium, calcium and barium sulfonates and phenolates.

Examples of other wear protection additives include:

Compounds containing sulfur and / or phosphorus and / or halogen, such as sulfurized vegetable oils, zinc dialkylthiophosphates, tritolyl phosphate, chlorinated paraffins, alkyl and aryl disulfides.

The use and effect of the lubricant compositions according to the invention are described in more detail in the following examples.

• 1) I.S.L.: Initial Seizure Load: das ist die Last, bei der der Oelfilm innerhalb einer Belastungsdauer von 10 Sekunden zusammenbricht.
• 2) W.L.: Welding Load: das ist die Last, bei der die 4 Kugeln innerhalb von 10 Sekunden zusammenschweissen.
• 3) W.S.D.: Wear Scar Diameter in mm: das ist der mittlere Verschleissdurchmesser bei einer Belastung von 70 kg bzw. 40 kg während einer Stunde.

Example 1: The following values are determined with the Shell four-ball apparatus (Method IP 239/79, Extreme Pressure Properties: Friction and Wear Tests for Lubricants: Four-Ball-Machine):

• 1) ISL: Initial Seizure Load: this is the load at which the oil film breaks down within a load period of 10 seconds.
• 2) WL: Welding Load: this is the load at which the 4 balls weld together within 10 seconds.
• 3) WSD: Wear Scar Diameter in mm: this is the average wear diameter at a load of 70 kg or 40 kg over an hour.

A 150 VG32 oil containing 5.0% by weight of a commercially available chlorinated paraffin hydrocarbon with 50% chlorine content, 1.0% by weight of a wear protection additive of the triaryl phosphate type and 0.5% by weight of N-oleyl sarcosine (rust Inhibitor), based on the entire oil formulation.

The results are shown in the table below.

Example 2: The procedure is as in Example 1, with the difference that a 150 VG 100 oil without costabilizers is used as the base oil. The results are shown in Table II below.

Example 3: Reichert test

The wear-inhibiting effect of the lubricant composition according to the invention is determined using a conventional lubricant measuring machine (H. Reichert, Maschinen- und Apparatebau). A test cylinder 2 cm long and 1 cm in diameter is pressed with a force p against a rotating grinding wheel, which rotates in an oil bath at a constant sliding speed of 1.7 m / sec (900 rpm). The test criterion is the wear cap that forms as a function of the friction path.

Test preparations:

The wheel and test specimen are ultrasonically cleaned in mineral spirits and acetone. The wheel is then run in four times with pure base oil (friction path 100 m). With this defined roughened slip ring, a wear cap of 36-40 mm ^{2 is} obtained under standard conditions (100 m friction path, p = 14.7 N) with pure base oil. This value is checked four times before the actual test.

Test execution:

The lubricant composition to be tested (basic formulation and additive) is tested under standard conditions (100 m friction path, p = 14.7 N). If the composition is effective, there is a marked reduction in the wear cap.

The basic formulation consists of a 150VG32 oil as the base oil, 5.0% by weight of a commercially available chlorinated paraffin hydrocarbon with 50% chlorine content, 1.0% by weight of a wear protection additive of the triaryl phosphate type and 0.5% by weight N-oleyl sarcosine (rust Inhibitor), based on the entire oil formulation.

The results are shown in the table below:

Claims (7)

1. Lubricant containing as an additive a compound of formula I.

or a mixture of such compounds in which R ^{1 is} C ₁ -C ₁₂ alkyl, unsubstituted or substituted by C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy or halogen, C ₆ C ₁₀ aryl or a group -OR ³ , R ² represents a group -C (O) R ⁴ or -CN, R ^{3 is} C ₁ -C ₁₂ alkyl, R ⁴ R ¹ , -NH ₂ , KH (R ⁵ ), -N (R ⁵ ) ₂ , a group - O- (CH ₂ ) _n -S (O) _m -R ³ , where n is an integer between 1 and 6 and m is zero or 1, or a group -CH ₂ -SR ⁶ is R ⁵ C ₁ -C _{12 is} alkyl and R ^{6 is} R ³ or -CN. 2. Lubricant according to claim 1, characterized in that they contain, as an additive, a compound of the formula I in which R ^{1 is} C ₁ -C ₄ alkyl, unsubstituted or substituted by C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy or halogen Is phenyl or a group -OR ³ , R ^{2 is} a group -C (O) R ⁴ , R ^{3 is} ethyl, tert-butyl, 1,1,3,3-tetramethylbutyl or 1,1,3,3,5 , 5-hexamethylhexyl and R ^{4 is} R ¹ or a group -O-CH ₂ CH ₂ -SR ³ , where R ^{3 has} the meaning already given in this claim. 3. Lubricant according to claim 1, characterized in that they contain as an additive a compound of formula I, wherein R ^{1 is} methyl or phenyl and R2 is a group -C (O) -OC ₂ H ₅ or -C (O) -OCH ₂ -CH ₂ -SC ₂ H ₅ means. 4. Lubricant according to claim 1, characterized in that they contain 0.001 to 5% by weight, based on the lubricant, of a compound of the formula I as an additive. 5. Use of compounds of formula I as additives to lubricants according to claim 1. 6. Use of compounds of formula I as "extreme pressure" and "antiwear" additives of lubricants according to claim 1. 7. Use of compounds of formula I as activators of chlorinated paraffins in metal processing oils according to claim 1.