DE1075255B - Lubricating oil - Google Patents

Description

The invention relates to hydrocarbon-based lubricating oils, particularly those used for lubrication under difficult working conditions, e.g. B. under extremely high pressure and at high temperatures are suitable.

It is known that the high pressures encountered in certain types of gears and bearings lead to a Cracking of the lubricating film and thus damage to the machine. Like before has been shown, different lubricant base materials can be compared with regard to their protective properties rubbing surfaces can be improved by giving them certain substances, the so-called high-pressure additives, added, so that excessive wear and / or the knocking or seizing of the bearings - the usual consequences when the lubricating film tears - largely avoided.

According to the current state of the art, one of the most effective measures is to use lubricants against to make extreme pressures resistant by giving them a small amount of an oil-insoluble polycarboxylic acid, such as tartaric acid, citric acid, added. For stable dispersion or dissolution of high pressure additives of this kind in lubricants, such as mineral oils, a wide variety of auxiliary solvents have been proposed, z. B. nonionic substances such as polyalkylene oxides and their derivatives or partial esters of fatty acids and alkane polyols and mixtures of such materials. Usually it was found that the co-solvents the effect of the oil-insoluble polycarboxylic acids in the oils with regard to the high pressure resistance cancel or at least reduce it. Another means of solubilizing the oil-insoluble polycarboxylic acids in mineral oils consists in the esterification of these acids with long-chain aliphatic alcohols, such as Octadecanol, or in the formation of polyvalent metal salts of acids. The modification of the polycarboxylic acids in this way, however, also adversely affects the beneficial effect of the polycarboxylic acids on the The high pressure resistance of the lubricant is essential.

Additives to lubricants in the form of compounds of carboxylic acids and amines have been proposed earlier. Oil-soluble salts of this type are said to increase the initial stability of the oils or to prevent oxidation. The use of amides based on the above as a rust preventive additive or as a thickener for lubricating greases is also known. For high-pressure lubricating oils, however, such additives, which do not reveal any complex nature, are less suitable, since they generally do not have the necessary stability under extreme pressure and temperature conditions and, as in the salts or amides, similar to the esters and metal soaps, the most favorable Effect of the polycarboxylic acids is severely impaired.

In contrast, it has now been established that as a special

Applicant:

NV De Bataafsche Petroleum
Maats chappij, The Hague

Representative: Dr.-Ing. F. Wuesthoff, Dipl.-Ing. G. Pulse

and Dipl.- Chem. Dr. rer. nat. E. Frhr. v. Bad luck man,

Patent Attorneys, Munich 9, Schweigerstr. 2

Claimed priority:
V. St. v. America December 16, 1957

George Milton Calhoun, Berkeley, Calif. (V. St. Α.), Has been named as the inventor

As stable extreme pressure lubricants, those lubricating oils are suitable that are contained in a hydrocarbon-based lubricating oil a smaller proportion of an oil-soluble complex

1. an oil-insoluble aliphatic carboxylic acid,

2. a fatty acid with at least 8 carbon atoms and

3. have an aliphatic amine with at least 8 carbon atoms.

The complex is prepared in such a way that the three reaction components (polycarboxylic acid, fatty acid and Amine) at a temperature below 85 ° C (e.g. between 20 and 85 ° C) in a non-polar solvent, z. B. a hydrocarbon such as benzene, or a light mineral lubricating oil, dissolves. Preferably the reaction that begins is allowed to go so far that a homogeneous liquid is formed. Each in that The basic nitrogen atom present in the amine should preferably be about a carboxyl group of a polycarboxylic acid and about one carboxyl group of a fatty acid may be present in the mixture. Is the amine a monoamine and If the polycarboxylic acid is a dicarboxylic acid, the three components are therefore preferably in a molar ratio of about 2: 1: 2 applied. It is essential that neither water nor Amides are formed. For this purpose, the temperature is controlled during mixing in such a way that 85 ° C must not be exceeded. If the temperature rises above 85 ° C during the mixing process, e.g. B. on 100 ° C or higher, a reaction product is obtained which has poor extreme pressure properties.

An unsubstituted aliphatic bicarboxylic acid can be used as the oil-insoluble aliphatic polycarboxylic acid with preferably 2 to 10 carbon atoms, such as oxal,

909 729/404

Malon, amber, giar, adipine, pimeline, sebacic, Azelaic or suberic acid, or an oxypolycarboxylic acid, such as tartaric or citric acid, be present. These satires can include short-chain alkyl radicals of 1 to 4 each C atoms and together do not contain more than 6 C atoms; Examples are the mono-, di- and trimethyls as well as the mono-, di- and triethyl or monobutyl derivatives of glutaric, adipic, pimeline or Suberic acid. As special examples from this body class his mentioned: 2-methylglutaric acid, 2-methyladipic acid, 2-methylpimelic acid, 2-methyl suberic acid, 3-methylglutaric acid, 3-methyladipic acid, 3-methylpimelic acid, 3-methyl suberic acid, 2,2-dimethyl glutaric acid, 2,2-dimethyladipic acid, 2,3-dimethylglutaric acid,

2.3 - dimethyladipic acid, 3,3- dimethyladipic acid,

2.4 - dimethyladipic acid, 2,2,4 - trimethyladipic acid, 2,3,4 - trimethyl adipic acid, 2,2,4 - trimethyl suberic acid, 3-ethyl glutaric acid, 2-methyl-3-ethyl adipic acid, 2-methyl-4-butyl suberic acid and mixtures thereof. The unsubstituted dicarboxylic acids, individually or in a mixture, are preferred.

The fatty acids with at least 8 carbon atoms are oil-soluble per se, and the saturated ones are preferred or unsaturated fatty acids with 12 to 18 carbon atoms, such as lauric, palmitic, myristic, stearic, Oleic, linoleic or ricinoleic acid; if appropriate, the acids are used in a mixture.

The third component of the complex is an oil soluble one aliphatic amine with at least 8 carbon atoms, which is primary, secondary or tertiary and either saturated or can be unsaturated and its chain is straight or branched. Provide a preferred class of amines the saturated aliphatic primary amines with 12 to 24 carbon atoms in a straight or branched chain The straight-chain saturated aliphatic tertiary amines with 12 to 24 carbon atoms are also very useful, although the primary amines deserve preference.

Typical examples are monoamines, such as octyl

i> amine, dodecylamine, tetradecylamine, hexadecylamine, Octadecylamine, Octadecenylamine, Octadecadienylamine, Dioctylamine, Didocylamine, Dioctadecylamine, Dioctadecadienylamine, Lauryldirnethylamine or octadecyldimethylamine and the amines called, which differ from fats

Oils or solid fats such as cottonseed oil, soybean oil, coconut oil, pork fat or tallow. The N-alkyl polyamines, such as the N-alkyl diamines, which can be prepared by the process described in US Pat. No. 2,736,658, e.g. For example, the NC ₁₂ _ ₁₈ -Alkyltrimethylendiamine.

The primary aliphatic amines with a branched chain are commercially available as mixtures of tertiary alkyl primary amines with about 12 to 15 carbon atoms and as mixtures of tertiary alkyl primary amines with 18 to 24 carbon atoms. Atoms, the latter being derivable and obtainable from polymers of isobutylene. The amine nitrogen atom is directly bonded to a tertiary carbon atom.
The properties of bodies typical of this class are shown in Table I.

Table I.

Alkylamine »Aj«

formula

Molecular weight,

Average molecular weight

Specific weight at 25 ° C

Refractive index at 25 ° C

Boiling point or range

predominantly from

XC ₁₂ H ₂₅ NH ₂

to XC ₁₅ H ₃₁ NH ₂

predominantly from

185 to 227

191

0.812

1.423

5 to 90% at
223 to 240 ° C (760 mm)

predominantly from

XC ₁₈ H ₃₇ NH ₂ to TC ₂₄ H ₄₉ NH ₂ predominantly from 269 to 353 315 0.840 1.456

5 to 70% at 265 to 308 ° C (760 mm)

The tertiary alkyl primary amines, which are classified as tertiary alkyl radicals contain the polyisobutylene or the polypropylene radical, even in a mixture, for purposes of Invention particularly useful. So include 1,1,3,3,5,5-hexamethylhexylamine (from triisobutylene), 1,1,3,3,5,5,7,7-octamethyloctylamine (from tetraisobutylene) andl, l, 3,3,5,5,7,7,9,9-decamethyldecylamine (from Pentaisobutylene) to the particularly preferred amines.

Further suitable amines are 2,2,4,4-tetramethylpentylamine and 2,2,4,4,6,6-hexamethylheptylamine. Other Tertiary alkyl primary amines that can be used are those with 8 and more carbon atoms, such as they are described in U.S. Patents 2,160,058, 2,606,923 and 2,611,782, e.g. B. the tert-tridecylamine

C, H ₅

iso ~ C, H ₁₇ - C -NH,

C ₂ H ₅ or isoheptyldiethylcarbinylamine or isooctylethylpropylcarbinylamine.

Examples of complexes useful for purposes of the invention are as follows, those of mixtures were obtained in which the components were present in an equivalence ratio of 1: 1: 1.

Adipic acid - lauric acid - »Aj« (see Table I), adipic acid - lauric acid - · Lauryldimethylamine, d-tartaric acid - · Lauric acid - »Aj«, sebacic acid - lauric acid - »A _x «, oxalic acid - stearic acid - octadecylamine, adipic acid - oleic acid - · »A ₂ « (see Table I), citric acid - lauric acid - hexadecylamine, azelaic acid - lauric acid - octadecylamine, succinic acid - stearic acid - octadecyldimethyl

amine,
Tartaric acid - oleic acid - 1,1,3,3,5,5,7,7-octamethyl-

octylamine.

Preferred solutions of complexes according to the invention are shown in the following table:

Table la

Components percentage ownership
Weight
percent Molar
proportion of A. Adipic acid
Lauric acid 5
13.7
13.1
5
13.7
14.6
5
13.25
12.75
3.3
5
9.9
9.5 1
2
2 B. adipic acid
Lauric acid
Lauryl dimethylamine
C. d-tartaric acid
Lauric acid 1
2
2
1
2
2 2-propanol
D. Sebacic Acid
Lauric acid 1.6
1
2
2

The rest of the blends consists of a 1010 mineral oil, which is described below (see Table IV).

The complexes are expediently added to the oils in a proportion of 0.1 to 15 percent by weight, preferably from 1 to 10 percent by weight, admixed.

If necessary, you can add a small portion of the lubricant preparations, e.g. B. 0.1 to 5%, of a clarifying agent such as an alkanol, add. The function of the clarifying agent is to ensure that the complex is well distributed in the oil. Such clarifiers include aliphatic alcohols with 2 to 18 carbon atoms, such as ethanol, propanol, hexanol or the so-called "OXO" alcohols, which are derived from olefins with a branched chain, e.g. B. of the polymers of the lower alkenes with 3 to 5 carbon atoms and the copolymers from the mixtures of such alkenes. The composition of a typical C ₈ -OXO-alcohol mixture, as it is obtained from a mixture of C ₇ -olefins, which was produced by the polymerisation of a _{cracked gas fraction of C 3} - to C ₄ -hydrocarbons obtained during the refining, is given in Table II .

Table II

. ,,,, weight

^{A! Koho1} percent

3,5-dimethylhexanol 29

4,5-dimethylhexanol 25

3,4-dimethylhexanol 17

5-methylheptanol | _{1 fi}

3-methylheptanol j

5-ethylhexanol 2,3

5,5-dimethylhexanol 1,4

α-alkylalkanol 4.3

other 5.0

Synthetic hydrocarbon oils include the polymerized olefins, the alkylated aromatic ones Hydrocarbons, the isomerized waxes. Motor oils derived from petroleum are particularly useful with the following physical data:

Pour point in ° C
Flash point in ° C
Viscosity in cSt .. Tabel III (B)
SAE 30 *) IO 15 Viscosity index ... (A)
SAE 1OW *) -20.5
207
9.7 -23.3
199
5.5 60 90

*) see Zerbe, Mineralöle, Springer, 1952, pp. 840, 841.

The oil labeled (A) above is paraffinic, the oil labeled (B) is naphthenic.

Other useful oils are e.g. B. Gas turbine lubricating oils with the following properties:

Tabel IV drawing
1065 25th Technical E
1010 -17.8
240.5
114.7
0.01 Pour point in ° C
Flash point in ⁰ C
3 ° viscosity in cSt .. -23.3
149
10.4
0.02 Neutralization number
ash

example

A 1010 mineral oil (see Table IV) added 5 percent by weight from one of the solutions A, B, C or D, resulted in load values of in the transmission testing machine 393 to 446 kg / cm, while the same oil without additives

+0 mixture only withstood a load of 107 kg / cm. Mixtures of polycarboxylic acids such as adipic acid, sebacic acid or tartaric acid with amines such as "Aj" (see table I), or lauryldimethylamine led to oil-soluble products that were used as additives for mineral oils on the gearbox testing machine could not be examined. Also the reaction product between amines, like "Aj", and only one fatty acid at a time, e.g. B. lauric acid, when added to mineral oil, gave a gel.

The complexes according to the invention are also useful for improving the exercise capacity of Lubricating oils that contain small amounts of other additives, such as silicone-based antifoams, antioxidants based on alkylphenol, agents for improving the viscosity index based on polyacrylate esters.

55

Other examples of useful alkanols are 6-methyl -1 - heptanol, 2 - η - propyl -1 - pentanol, 3 - η - propyl-1 - hexanol, 2,2 - dimethyl -1 - octanol, 10,10 - dimethyl-1-undecanol, 3-isopropyl-1-heptanol and mixtures thereof.

The lubricating oils useful in forming the extreme pressure lubricants of the invention are the synthetic ones or natural hydrocarbon oils with a viscosity range of 2.2 to 54 cSt; SAE viscosity numbers (see Zerbe, Mineralöle, Springer, 1952, pp. 840, 841) from SAE 50 to SAE 90.

The natural hydrocarbon oils can be made from paraffinic, naphthenic, asphaltic or mixed Raw or basic materials are obtained.

Claims (9)

Patent claims: 1. Hydrocarbon-based lubricating oil, characterized by an additive in the form of an oil-soluble one Complexes, formed from the at temperatures below 85 ° C in a non-polar solvent, preferably a hydrocarbon, carried out reaction between an aliphatic Amine with at least 8 carbon atoms and about 1 equivalent of one per basic nitrogen atom of the amine oil-insoluble aliphatic polycarboxylic acid with at least 8 carbon atoms and about 1 equivalent of one Fatty acid with at least 8 carbon atoms. 2. Lubricating oil according to claim 1, dadxirch characterized, that the aliphatic polycarboxylic acid is a is unsubstituted dicarboxylic acid with 2 to 10 carbon atoms, preferably adipic or sebacic acid. 3. Lubricating oil according to claim 1, characterized in that the aliphatic polycarboxylic acid is a alkyl-substituted dicarboxylic acid in which the alkyl radicals each have 1 to 4 carbon atoms and not more together than 6 carbon atoms. 4. Lubricating oil according to claim 1, characterized in that that the aliphatic polycarboxylic acid is an oxypolycarboxylic acid, preferably tartaric acid. 5. Lubricating oil according to claim 1 to 4, characterized in that the fatty acid is one with 12 up to 18 carbon atoms, preferably lauric acid. 6. Lubricating oil according to claim 1 to 5, characterized in that the aliphatic amine is a saturated one is a primary amine with a straight or branched chain and 12 to 24 carbon atoms. 7. Lubricating oil according to claim 1 to 5, characterized in that the aliphatic amine is a saturated one straight chain tertiary amine and 12 up to 24 carbon atoms, preferably lauryldimethylamine. 8. Lubricating oil according to claim 1 to 7, characterized by a content of the oil-soluble complex in Amounts from 0.1 to 15 percent by weight, preferably from 1 to 10 percent by weight, based on the total weight of the lubricating oil. 9. Lubricating oil according to claim 1 to 8, characterized by an additional content of an aliphatic alcohol having 2 to 18 carbon atoms, for. Example in amounts of 0.1 to 5 ° / _0, based on the total weight of the lubricating oil. Considered publications:
U.S. Patent Nos. 2,580,881, 2,693,448;
British Patent No. 774085;
Journal of Physical Chemistry (1952), pp. 604 to 610. Legacy Patents Considered:
German Patent No. 1 042 808. © 909 729/404 2.