DE2221646C2 - Lubricating oil preparations - Google Patents

Description

R ¹ X ¹ -P-S-NH ₃ R ⁴ • OH
R ² X ²

or the general formula

Il θ 9

V— Ρ— S - N

NH ₃ R ⁴ OH

R ³ -X ²

contains, in which the radicals R ¹ , R ² and R ^{4 are} hydrogen and carbon-containing groups, R ^{3 is} a divalent aromatic group and X ¹ and X ^{2 are} oxygen or sulfur atoms.

2. Lubricating oil preparation according to claim 1, characterized in that it contains a salt of a primary monohydroxyamine of the above general formula in which the radicals R ¹ and R ^{2 are} both Ci to Cjs-alkyl groups.

3. Lubricating oil preparation according to claim 1, characterized in that it contains a salt of a primary monohydroxyamine of the above general formula in which the radicals R ¹ and R ^{2 are} both alkylphenyl groups, the alkyl part having 1 to 18 carbon atoms.

4. lubricating oil preparation according to claims 1 to 3, characterized in that it is a salt of a contains primary monohydroxyamine of the above general formula, which differs from a Monoalkanolamine, preferably a monopropanolamine, derived.

This invention relates to lubricating oil formulations which, in addition to the base oil, include an amine salt of a thiophosphoric acid contain.

Certain amine salts of thiophosphoric acid are already known. also as ash-free Anti-abrasion additives have found use in lubricating oils. From DE-PS 12 85 085 is already one mineral and synthetic lubricant that is a reaction product of an optionally substituted Contains dithiophosphoric acid and a primary and secondary amine, known. Hydroxyamines are used for the production of the reaction product is not used. DE-AS 12 64 661 also relates to one Mineral and synthetic lubricant containing an alkyldithiophosphoric acid salt, which is a reaction product an optionally substituted dithiophosphoric acid and a condensation product from elier di- or polycarboxylic acid, their anhydrides or a mixture thereof and an N-aliphatic dialkanolamine having 1 to 50 carbon atoms in N-aliphatic radical. Salts of dithiophosphoric acid with a hydroxyamine are not described. DE-AS 11 51 085 claims a mixture of lubricants based on lubricating oil, which contains a minor content of an oil-soluble phosphonic compound although the phosphorus atom can also be linked to up to 3 sulfur atoms, the preferred ones Compounds (column 1, lines 45 to 52) but are obviously sulfur-free. Hydroxyamine salts of these Phosphonic compounds are not mentioned. DE-OS 19 37 439 contains a method for production of S-alkenyl-O-alkyl-dithiophosphate salts and -complexes, in which a 5, -alkenyl-O, O'-dialkyl-dithiophosphate ester treated with a dealkylating agent. These are similar connections to the one below Example as a comparison mentioned prisms 8IR-SaJz.

It should also be noted that all the products of this laid-open specification, in contrast to the amine salts of the invention do not have any sulfur-nitrogen bonds. The US-PS 31 14 712 used as an oil-soluble Lubricant additive a mixture of thiophosphoric acid esters and a molybdenum-amine complex. Hydroxyamines are not mentioned and it is assumed that the two components are one form physical mixture and do not react with each other. The US-PS 31 03 492 describes lubricant preparations, contain the amine salts of thiophosphoric acids. Although after column 2, line 63 and column 3, line 48 also mentions the use of hydroxyamines for salt formation, it is at these are not primary amines, so that their behavior is similarly unsatisfactory as the behavior of the im the example below will be triethanolamine mentioned as a comparison. The US-PS 30 58 910 relates an additive concentrate for lubricating oils, which essentially consists of a hydrocarbon lubricating oil, that is a mixture of an oil-soluble addition product of the acid thiophosphate ester of nonylphenol and Phosphorus pentasulfide with an alkylenediamine, and still the oil-soluble addition product of a Contains petroleum sulfonic acid and an alkylenediamine. Amines with hydroxyl groups are not mentioned. the in US-PS 29 73 323 described lubricant preparation contains a heterocyclic polyamine salt of a phosphorodithioic acid ester, the amines not containing any hydroxyl groups. It did, however found that the use of known amine salts leads to the formation of storage discoloration, which as Corrosion phenomena are undesirable.

There was therefore a need for lubricating oil formulations which, in one of the formulations of the prior art Wear behavior comparable to the technology has a reduced corrosiveness.

The object on which this invention is based therefore consisted in producing lubricating oil preparations from a lubricating oil and 0.001 to 20 percent by weight - based on the oil - of an amine salt Thiophosphoric acid, with improved corrosion behavior, in terms of its anti-abrasion properties are no worse than the known preparations.

This object was achieved according to the invention in that the lubricating oil preparation is used as an amine salt Salt of a primary monohydroxyamine of a dithio-

phosphoric acid, a trithiophosphoric acid or a tetrathiophosphoric acid of the general formula

R ¹ X ¹ -P-S-NH ₃ R ⁴ • OH

R ² X ²

or the general formula
S.

I θ β

Χ ¹ -Ρ-S-NH ₃ R ⁴ OH

! • -A-

contains, in which the radicals R ¹ , R ² and R ^{4 are} hydrogen and carbon-containing groups, R ^{3 is} a divalent aromatic group and X ¹ and X ^{2 are} oxygen or sulfur atoms.

The radicals X ¹ and X ² are preferably the same, ie both sulfur or both oxygen atoms, although they can also be different. In practice it is preferred that both X ¹ and X ^{2 be} oxygen atoms.

R 'and R ² can be aliphatic or aromatic radicals, for example hydrocarbyl groups, such as alkyl, aryl, alkaryl or aralkyl groups.

Preferred lubricating oil formulations of this invention contain a salt of a primary monohydroxyamine of the above general formula in which the radicals R ¹ and R ^{2 are} both C1 to C2 alkyl groups.

Suitable alkyl groups are, for example, propyl, n-hexyl, sec-octyl, isodecyl, tetradecyl or eicosyl groups.

Suitable aryl groups include phenyl, naphthyl and anthranyl groups.

Furthermore, lubricating oil preparations according to the invention are preferred which contain a salt of a primary monohydroxyamine of the above general formula in which the radicals R ¹ and R ^{2 are} both alkylphenyl groups, the alkyl part having 1 to 18 carbon atoms.

Examples of such alkylphenyl groups are tolyl, xylyl, nonylphenyl, dodecylphenyl, octadecylphenyl, Called dibutylphenyl, butylpentylphenyl and dinonylphenyl groups.

Suitable aralkyl groups include benzyl, 2-phenylbutyl and 2-phenylethyl groups. The groups R ¹ and R ² are usually the same, but can also be different. The groups R ¹ and R ² can also contain oxygen atoms in addition to carbon and hydrogen, ie they can be alkoxyalkyl, for example methoxybutyl or alkoxyaryl, for example ethoxyphenyl or aryloxyalkyl, for example phenoxyethyl groups.

The group R ³ is aromatic and can be, for example, a phenylene group, bisphenylene group or an alkylated derivative of these groups, in which case the thiophosphoric acid is derived from catechol, resorcinol, bisphenol or their alkylated derivatives or thio analogs.

The radicals R ¹ , R ² and R ³ are preferably hydrocarbyl groups, ie they contain no other atoms apart from carbon and hydrogen. However, they can optionally also have polar substituents, e.g. B. chlorine or bromine atoms, or have keto, ether, aldehyde or nitro groups. Preferably these polar substituents are not present to such an extent as to significantly alter the hydrocarbon character of the group, and therefore usually no more than 10 percent by weight, based on the hydrocarbyl portion of the group, of these polar substituents.

The amine salts of thiophosphoric acids contained in the lubricating oil preparations according to the invention

ίο have a primary monohydroxyamine as the salt-forming amine the general formula

H ₂ NR ⁴ OH

in which the radical R ^{4 is} a hydrocarbyl group, and in particular a saturated, aliphatic, e.g. B. alkylene group, but also a. = Arylene, aralkylene or Alkarylcngruppe can be. Further examples of R ⁴ are cyclopentylene, cyclohexylene, phenylene, naphthylene and anthracene. Suitable monoalkanolamines are, for example, monoethanolamine, monopropanolamine, monobutanolamine, 6-amino-1-hexanol and 5-amino-8-octanol. The radical R ⁴ preferably contains 1 to 20 carbon atoms, e.g. B. 1 to 10 carbon atoms.

A particularly suitable alkanolamine salt is the isopropanolamine salt.

The amine salts contained in the lubricating oil preparations of the invention can be prepared by reacting the thiophosphoric acid with the primary monohydroxyamine, preferably the amine at elevated temperature, e.g. B. at 50 ° to 12O ⁰ C in the course of a certain period of time, for. B. in the course of about 30 minutes, to which thiophosphoric acid is added. The thiophosphoric acid can be prepared as such in situ, for which purpose, for example, P2S5 is reacted with an alcohol or the corresponding thiol. Approximately stoichiometric amounts of the reactants should be used in the reaction. Preferably, in an inert atmosphere, e.g. B. worked under nitrogen.

Suitable lubricating oils to which the amine salts are added are animal, vegetable or Mineral oils, e.g. B. Petroleum fractions from spindle oils to SAE-30, SAE-40 or SAE-50 lubricating oils, castor oil, Fish oils, oxidized mineral oil, or bright stocks. The lubricating oil can be a synthetic ester oil such as e.g. B. obtainable by esterification of carboxylic acids, such as adipic or sebacic acid, with monohydric alcohols Diester, through esterification of polyhydric alcohol,

z. B. polyglycol, with a dibasic acid, e.g. B.

Sebacic or adipic acid and a monohydric alcohol, e.g. B. 2-ethylhexanol or a Cg-oxo alcohol, available complex esters.

The amount of amine salt added to the oil to make the lubricating oil composition of the invention is, must be between 0.001 and 20 percent by weight, based on the weight of the oil, and the preferred amount added to the lubricating oil is between 0.01 and 10 weight percent, e.g. B. between

bo 0.1 and 5 percent by weight, based on weight of the lubricating oil.

As can be seen from the example below, those conferring from the primary hydroxyamines The resulting salts of thiophosphoric acids and lubricating oils have a comparable wear behavior but of considerably less corrosiveness than similar compounds that do not contain a hydroxyl group included (e.g. primers 81R) or tertiary

5 6

Amines that contain hydroxyl groups, such as triethanolamine. The following example serves to explain the invention in more detail.

example

The ethanolamine salt of isodecanol dithiophosphoric acid. was prepared according to the following reaction scheme:

2C ₁₀ H ₂₁ OH + 1 / 2P ₂ H ₅

C ₁₀ H ₂₁ OP-SH + H ₂ N-CH ₂ -CH ₂ -OH
C ^ H ₂₁ O

Jl e
C ₁₀ H ₂₁ O-P-S-NH ₃ - CH ₂ -CH ₂ -OH

C, .H ₂₁ 0

44.4 g of P2S5 were slurried in 67.0 g of mineral lubricating oil (viscosity 150 SSU at 38 ° C.) with slow stirring. 132.6 g (corresponding to an approximately 5% stoichiometric excess) of isodecanol were then added to the mixture over the course of 5 hours and the temperature was increased to 100 ° C. for 1 hour. A clear, dark liquid was obtained. Then, over 30 minutes, 24.4 g of ethanolamine were added at 100 ° C. (the maximum temperature reached being 110 ° C.) and stirring continued for an additional hour until the reaction was complete. The mixture was (576 mbar) stripped to remove excess isodecanol in vacuum at 100 ⁰ C. The reaction was carried out under nitrogen.

The monoisopropanolamine salt of isodecanol dithiophosphoric acid was prepared as follows:
63.0 g of P ₂ Ss vurden in the course of 2 hours to 189.6 g of isodecanol and 94.2 g mineral lubricating oil (viscosity: 150 SSU at 38 ° C), which was heated to 6O ⁰ C, was added. The reaction mixture was held at 100 ° C for 3 hours and vacuum stripped _{to remove H 2 S.} After cooling the liquid to 6O ⁰ C

39.0 g of monoisopropanolamine were obtained in the course of 1

Added hour and the temperature below 70 ° C

held. A clear, amber-colored,

movable liquid.

To a mineral lubricating oil (viscosity: 150 SSU at

38 ° C, 42 SSU at 100 ° C) was based on the

Weight of the oil of the oil solutions prepared above, 1

Percentage by weight of the various alkanolamine dithio-

phosphate and the other amine salts were added.

Investigations with the Shell four-ball

Apparatus at various loads with the oil alone and with the oil carried out above contained the amounts of the various amine salts mentioned. The following results were obtained obtain:

Sweat Abrasion (mm) *) load scarce 1.00 kg kg 1.35 Base oil alone 124 30th 2.50 40 0.30 60 Base oil + monoethano) - 180 30th amine salt of isodecanol 0.95 phosphorodithioic acid 1.10 Base oil + monoiso 180 40 1.02 propanolamine salt of 60 Isodecanol dithio 60 1.80 phosphoric acid Base oil -: Triäthanoi- 140 60 amine salt of iso- decanoidithio- 1.20 phosphoric acid **) Base oil + priming 185 60 81R-S (Uz von Hexyien- glykoidithio phosphoric boric acid

*) 1 hour with various loads. **) Very low dysnosity.

Base oil *)

Storage weight loss after 36 hours at 140 ° C

(mg)

Stock color

30th

No additive 1810 Clean Base oil + 1% by weight Mono- 31 Clean

isopropanolamine salt of Isodecanol dithiophosphoric acid

Base oil + 1.4 wt% 23 Clean

MonoäUunoUminsalz of Isodecanol dithiophosphoric acid

Base oil + 1% by weight tri-102 brown

äthinoüüüinsai »from Isodecanolditbiophoapbomure

BasisöS +1% by weight Primen 53 Black

81R salt of hexyteaglycol dithiophosphoric acid.

*) The base oil contains a dispersant (polyamine) and a Vl-Vetteaercr (Athyfnmischpolyinerisat) on SAE LOW-30 for the base oil.

From the values obtained it can be seen that the monohydroxyamine salts of the invention have stress properties at least at least those of the Prior art additives (prisms 81R-SaIz) are equivalent and that they are better Have loading properties than other additives according to the prior art (triethanolamine salt).

Measurement of the Cu / Pb bearing protection

A bearing corrosion system, as described by Staudt et al (SAE 680538), was used to evaluate bearing weight loss and bearing color Petter Wl bearings are used.

The results obtained show that the monoalkanolamine salts of the invention do not discolor in storage cause, while the additives of the prior art either form tar or a high Storage weight loss (Trtfthanolaminalz) result or also the copper, lead storage (Primen 81 R-SaIz) black.

ASTM D-130 Copper Corrosion Test

15th

20th

Thiophosphoric acid amine

ASTM D-130 ·)

Isodecanol Isodecanol Isodecanol

Hexyleoglycol

(2-methylpentane

2,4-diol)

Monoethanolamine 1 b Monoisopropanolamine 1 b Triethanolamine 1 b

Priming 81R 2a

*) 1 percent by weight of amine dithiophosphoric acid in one Mineral lubricating oil with the physical properties: viscosity 150 SSU at 38 ° C, 42 SSU at 99 ° C.

As can be seen from the values obtained, the ASTM copper corrosion test is carried out on lubricating oil formulations containing the additives of this invention contain less corrosion of the copper strip than with preparations that contain an additive according to the prior art included in the technology.

Claims (1)

Patent claims: 1. Lubricating oil preparation, consisting of a lubricating oil and 0.001 to 20 percent by weight - based on the oil - an amine salt of a thiophosphoric acid, characterized in that the lubricating oil preparation as an amine salt is a salt of a primary monohydroxyamine one Dithiophosphoric acid, a trithiophosphoric acid or a tetrathiophosphoric acid of the general formula