DE1144865B - Turbine Lube - Google Patents

Description

GERMAN

PATENT OFFICE

E20009IVc / 23c

REGISTRATION DATE: OCTOBER 6, 1960

NOTICE DEK REGISTRATION AND ISSUE DEB EDITORIAL: MARCH 7, 1963

The invention relates to turbine lubricating oils that have low neutralization numbers as well as a high one Have pressure absorption capacity, which cadmium or lead di (sec.) - alkyldithiophosphate as Supplements included.

The use of metal thiophosphates to improve the pressure absorption capacity of Mineral lubricating oils are known. So far, however, zinc thiophosphates have been used almost exclusively for this purpose used. However, the use of zinc thiophosphates is not entirely satisfactory, because this type of metal thiophosphate gives the oil too high an acidity (neutralization number). It is known that good blends of lubricating oils, particularly turbine oils, should be nearly neutral, i.e. H., the lubricating oil mixture should have an extremely low neutralization number. Lubricating oils that something are acidic, because they often cause corrosion, while they are too basic Lubricating oils often lead to sludge formation during storage and use. Although the titratable Acidity of zinc dialkyldithiophosphates is normally not corrosive, as it interferes with the tests, which must be carried out with the lubricating oil in operation. So it is z. B. usual, the neutralization number of turbine oils at regular intervals. When the neutralization number (as a result of the formation of oxidation products) exceeds a certain value, the oil is changed, before the system can suffer damage. The fact that zinc dialkyldithiophosphates are the One reason why zinc dialkyldithiophosphates hinder implementation of this commonly established test method is containing turbine oils are not accepted commercially and are not approved for use in the navy. In view of most buyers of turbine lubricating oils require these difficulties in their standard regulations, that the maximum neutralization number of the oil is below 0.2.

There are also already known lubricating oils which contain a cadmium dialkyldithiophosphate as an additive. In these known lubricating oil additives, however, either both alkyl groups of the cadmium dialkyldithiophosphate were primary alkyl groups, or one of the two alkyl groups was an isopropyl group while the other was a primary alkyl group. Likewise, lubricating oil mixtures are known that are used as additives to increase the drainage capacity by fluorine-substituted metal dialkyldithiophosphates contain, in which the alkyl groups can be derived from secondary alcohols and as Turbine lubricating oil

Applicant:

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

Representatives: E. Maemecke and Dr. W. Cool,
Patent Attorneys, Hamburg 36, Esplanade 36 a

Claimed priority:
V. St. v. America of November 2, 1959 (No. 850 462)

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

Henry E. Ertelt, Fanwood, N.J.,

and Jack Rockett, Westfield, N.J. (V.St.A.),

have been named as inventors

a5 metals zinc, iron, barium, nickel, aluminum, Cadmium, tin, magnesium, calcium or strontium come into consideration.

It has now been found that the replacement of the previously known Metalldialkyldithiophosphate by not fluorine-substituted cadmium or lead dialkyldithiophosphates, all of which are alkyl groups derived from secondary alcohols, leads to turbine oils that have a very low neutralization number exhibit.

The turbine lubricating oils of improved pressure capacity according to the invention with a Content of a metal salt of a diakyldithiophosphoric acid with derived from secondary alcohols Alkylgrappen, in which the metal can be cadmium, are characterized by that they are a cadmium or lead salt of a dialkyldithiophosphoric acid with 9 to 24 carbon atoms in the molecule in which all the alkyl groups are derived from secondary alcohols, in amounts from 0.20 to 3.0 percent by weight, based on the total amount of the lubricating oil mixture.

The turbine lubricating oils improved according to the invention have a maximum neutralization number (determined according to ASTMD-974) below 0.2 and an extremely high pressure absorption capacity. It was found - and that statement forms the Basis of the invention - that the alkyl groups of

_; 30 »538/381

used to produce these lubricating oil blends Dialkyldithiophosphate all of secondary Must be derived from alcohols. To dialkyldithiophosphate of sufficient oil solubility 2x1 obtained, these secondary alcohols generally contain on average at least about 4.5, preferably 6 to 12 carbon atoms in each alkyl group. You can use secondary alcohols with 3 to use about 20, e.g. with 3 to 13 carbon atoms, the reaction being carried out in such a way that the resulting ^ dialkyldithiophosphates as a whole Contains 9 to 24 carbon atoms in the molecule. It is also important that the metal in the Metal dithiophosphate is cadmium or lead. Lubricating oils containing this type of dithiophosphate (their alkyl groups z. B. can have an average of 6 carbon atoms) in amounts up to about 3.0 percent by weight, z. B. from 0.375 to 1.5 percent by weight, have a determined according to ASTM D-974 Neutralization number less than 0.2. Lubricating oils that contain more than about 0.75 percent by weight of this Contain type of thiophosphates, show in the Ryder gear test (described in »Wright Air Development Center, Detailed Handbook on Test Procedures in Support of Turbojet and Turboprop Lubes ”, or in Army Standard Regulation MIL-L-17331A [for ships], 4.6.2.) a pressure absorption capacity of more than 536 kg / cm (3000 lbs / inch). If such a high pressure absorption capacity is not required, lower concentrations can also be used apply to dithiophosphates.

The dialkyldithiophosphates which are considered here have the general structural formula

R'O ^XX S

in which R and R 'mean secondary alkyl groups each having 3 to about 20 carbon atoms with the proviso that the sum of the carbon atoms in the radicals R and R 'is 9 to 24. The mean of R and R 'are at least about 4.5 carbon atoms. Preferably, R and R 'have an average value in the range of about 6 to 12 carbon atoms. M means cadmium or lead.

All known lubricating oils can be used as the lubricating oil base, e.g. B. animal, vegetable, synthetic and mineral oils; however, the latter are preferred. Preferably the oil base a viscosity in the range of 37 to 150 SUS at 98.9 ° C, a viscosity index in the range of 50 to 150, a flash point above 188 ° C, a stick point below -3.9 ° C and a specific one Weight from 0.8984 to 0.855. A solvent-extracted neutral oil is used for turbine oils of a viscosity index in the range of 90 to 115 are generally preferred.

Examples of suitable synthetic oils are diesters, such as di-2-ethylhexyl sebacate, complex esters, like the reaction product of 2 parts of di-2-ethylhexanol, 2 parts of a dicarboxylic acid and 1 part Polyethylene glycol with an average molecular weight of 200; Silicone oils such as polydimethylsiloxane, which produced by hydrolytic condensation of dimethyldichlorosilane, phosphorus derivatives, such as Cg oxodiphenyl phosphate.

The turbine lubricating oils according to the invention usually also contain one per se known corrosion retardants in amounts of from 0.005 to 0.5, for example from 0.01 to 0.10 percent by weight. As is well known, lubricating oils can be used in a variety of ways depending on their intended use Corrosion retardants available. For the turbine oils preferred according to the invention, the critical ones Must meet requirements have proven corrosion retardants mercaptoacetic acids of the formula

RS-CH ₂ -COOH,

in which R is a branched-chain alkyl group with 9 to 17 carbon atoms, as particularly proved suitable. Preferably, R is a branched chain alkyl group of about 13 carbon atoms. Other valuable rust inhibitors known per se for the turbine lubricating oils according to the invention are alkenylsuccinic acids with the general structural formula

R-CH - COOH

CH ₂ -COOH

in which R is an unsaturated aliphatic radical having about 10 to 22, preferably about 12 to 18 carbon atoms. Compounds in which R is a saturated radical can also be used. Rust inhibitors of this type are known per se. In practice, the radical R is generally a mixture of groups of different chain lengths with an average value of about C ₁₄ to C ₁₈ . Such mixtures are preferred as rust inhibitors for the lubricating oils of the invention. The rust inhibitors derived from succinic acid or from mercaptoacetic acid are used in concentrations in the range from 0.01 to 0.10 percent by weight, based on the total amount by weight of the lubricating oil mixture. Preferably, the concentrations of the succinic acid derived rust preventive are in the range of 0.03 to 0.05 percent by weight of the total lubricating oil mixture. Other known rust inhibitors such as dinonylnaphthalene sulfonate can also be used.

The oxidation resistance and the pressure absorption capacity, the composition according to the invention Lubricating oils given by the dithiophosphate additives are great for most Applications completely sufficient. However, it may be useful for some special purposes be to add other additives. Additional oxidation retardants are e.g. B. the per se known phenols and amines, such as 2,6-di-tert-butylp-cresol or phenyl-a-naphthylamine. As an additional High pressure agents can, for. B. halogen-containing organic compounds, such as chlorinated hydrocarbons, z. B. chlorinated wax, and chlorinated terpenes such as chlorinated camphene can be used. Even these high pressure additives are known per se. The chlorinated hydrocarbons are particularly valuable for the lubrication of certain slowly moving machine parts and can be used in concentrations in the range from about 0.20 to 5 percent by weight, based on the total amount of the lubricating oil mixture, can be applied. If such other additives are used within the meaning of the invention are added, they are added to an oil mixture, which by virtue of its lead content

or cadmium dialkyldithiophosphate has a low neutralization number and an improved pressure absorption capacity and has good resistance to oxidation and e.g. B. with regard to these properties Requirements of the test standard MIL-17331A (for Ships) dated September 27, 1955 is sufficient.

The preparation of the dialkyldithiophosphates to be used according to the invention as lubricating oil additives, for which patent protection is not claimed here, is carried out either by reacting the relevant secondary alcohols with phosphorus pentasulfide to form the free dialkyldithiophosphoric acid and then neutralizing the acid with cadmium oxide or by double conversion, ie by reacting an aqueous solution of an inorganic lead or cadmium salt with an alkali dialkyldithiophosphate. When preparing the free dialkyldithiophosphoric acid, it is advisable to observe the following measures: (1) The phosphorus content of the phosphorus pentasulfide should be below the theoretical value of 27.87 percent by weight and preferably below about 27.8 percent by weight, e.g. B. in the range of 26.0 to 27.5 percent by weight. (2) The hydrogen sulfide is removed from the acid prior to its neutralization with the aid of an inert gas, e.g. B. nitrogen, driven out. (3) Just prior to neutralization, elemental sulfur is added to the acid. The latter measure is not always necessary if the phosphorus content of the P ₂ S ₅ used for the preparation of the acid is in the vicinity of the lower limit of the range given above. Of the above precautions, the first is the most important.

The turbine lubricating oils according to the invention are produced by simply mixing the cadmium or lead dithiophosphate with the lubricating oil base in concentrations in the range from 0.20 to 3.0, e.g. B. 0.375 to 1.5 percent by weight of dithiophosphate, based on the total amount of the lubricating oil mixture. The dithiophosphate can be used without a diluent or as an oil solution which z. B. 50 to 90 ⁰ Zo dithiophosphate contains. As further additives, viscosity index improvers, pour point depressants, extreme pressure additives, oxidation retardants and anti-foaming agents can be added to the lubricating oils according to the invention. The usual sludge inhibitors are not added to the turbine oils preferred according to the invention. However, it is within the scope of the invention to add the special cadmium and lead thiophosphates described here to lubricating oils which contain sludge inhibitors.

Anti-foaming agents are not normally included in the lubricating oil blends of the present invention necessary. However, a silicone oil can optionally be used as an anti-foaming agent. If a silicone oil is added, this is done in concentrations in the range from 0.0001 to about 0.01 percent by weight of the total mixture.

The turbine lubricating oils according to the invention show an extremely high pressure absorption capacity, good ones Oxidation resistance and a low neutralization number. The combination of high pressure absorption capacity and a low neutralization number is required for most turbine oils by the army standards, z. B. from the naval regulations of the United States of America, Great Britain and Canadas, required. According to a particularly preferred embodiment of the invention the lubricating oil mixture has a neutralization number determined according to ASTM test standard D-974 of less than about 0.2.

Examples

A. Manufacture of cadmium and lead dithiophosphates

The following table explains the manufacture of the

ίο according to the invention to be used cadmium dialkyldithiophosphates (samples 1, 2, 3 and 4). The table also shows the preparation of a similar cadmium dialkyldithiophosphate from an acid having primary alkyl groups (Sample 5). A comparison of p _H values and neutralization numbers (ASTM D-974, ie, milligrams of KOH / gram of additive per) shows the products of Samples 1 to 4 with the sample 5 that one neutral according to the invention Cadmiumdialkyldithiophosphatzusätze obtained. Although the table shows considerable differences in the neutralization numbers depending on the production method, it should be noted that all of the cadmium compounds listed in the table have much lower neutralization numbers than the corresponding zinc compounds, regardless of how they are produced. A typical zinc di-C ₆ dithiophosphate corresponding to samples 2, 3 and 5, has a neutralization number of 171.8 and a _pH value of 5.4 in solution in a refined 75gewichtsprozentiger Coastal-Destinatöl from a nominal viscosity of 40 SUS at 98.9 ° C.

To further explain the improvement in the neutralization number of the cadmium dialkyldithiophosphates in the production from secondary alcohols, further samples of the C ₆ dithiophosphate prepared from methyl isobutyl carbinol according to Table I and a mixture of a secondary alcohol (30 weight percent C ₃ alcohol and 70 weight percent C ₆ alcohol ) produced C ₃ / C _e -dithiophosphate shown. The ratio of the neutralization number (ASTM D-974) to the percentage of phosphorus in the dithiophosphate is determined (i.e. milligrams of KOH per gram of additive / percent by weight of phosphorus) and compared with results obtained with cadmium dialkyldithiophosphates, which are obtained in the same way but from primary alcohols are made. These results are shown graphically in the figure. Each horizontal line in the bar graph represents a particular approach.

The effect of the phosphorus content of phosphorus pentasulphide on the composition of the dialkyldithiophosphates is shown in Table II. In particular, this table shows that the phosphorus pentasulfide of a high phosphorus content gives a dialkyldithiophosphoric acid, which according to the ratio S: P apparently has the right composition, but results in neutralized products in their Composition differ widely from the theoretical values. If, on the other hand, a phosphorus pentasulphide is used with a lower than the theoretical phosphorus content of 27.87 percent by weight, in this way, under the most varied of working conditions, products are obtained which meet the theoretical values correspond quite exactly. Also the neutralization numbers from the phosphorus pentasulphide are lower Products manufactured with phosphorus content are significantly lower.

7 8

Table I.
Production of cadmium dialkyldithiophosphates

Making the acid

sample

K ⁴ ) 2C)

3C) I 4 MIBCP) MIBC m 100 100 3 3 85 85 0.990 0.996 167 - 9.65 9.90 19.7 20.38 2.04 2.06 (6) 130 140 3 7th 85 85 2.7 8.0 10.91 11.64 6.58 6.44 13.30 13.57 1.66 1.80 2.02 2.10 2.7 7.6 7.8 3.2

alcohol

P ₂ S ₅ ,% of theory

Response time, hours

Reaction temperature ^{, 0 C}

Specific weight at 15.6 ° C .. Neutralization number (ASTM D-974)

Phosphorus, weight percent

Sulfur, weight percent

Ratio S: P (2)

Neutralization

CdO,% of theory

Response time, hours ..
Reaction temperature ^{, 0 C}
Final pH value

100 3 85 1.048
206
11.76
23.67
2.02

(β)

140 9

85 7.8

Products*

Cadmium, weight percent 13.29

Phosphorus, weight percent 7.37

Sulfur, weight percent 15;

Cd: PO ratio 1.80

Ratio S: p ( ² > 2.16

Ph 7.8

Neutralization Number (ASTM D-974) 6.0

C) P2SS with a phosphorus content of 27.5 percent by weight. ( ^e )

( ² ) Theoretical ratio S: P = 2.07. ~

( ³ ) Theoretical ratio Cd: P = 1.81. ( ⁸ )

( ⁴ ) The hot acid is blown with nitrogen for 1 hour before neutralization. *

( ⁵ ) mixture of 62.5 parts by weight of sec. Butanol and 37.5 parts by weight of methyl isobutyl carbinol.

MIBC P) 100
3

85

0.996 176
10.06 20.69 2.06

(6)

140
4th
85
7.8

11.74 6.16

13.81 1.90 2.24 7.8 3.3

C ₄ / C ₅ (8) 100 3 85

217 12.00 25.04 2.09

123 3

85 5.5

9.22 10.16 20.60

0.91

2.03

4.6 13.6

Addition of 0.5 percent by weight of sulfur flowers to the acid (based on the amount of acid). Methyl isobutyl carbinol.

Mixture of 65 percent by weight primary isobutyl alcohol and 35 percent by weight primary mixed amyl alcohols.

As 75 weight percent solutions of the additive in a refined coastal distillate oil of nominal viscosity of 40 SUS at 98.9 ° C.

Table II
Influence of the phosphorus content of the P ₂ S ₅

Acidic product: Produced by reacting methyl isobutylcarbinol with P ₂ S ₅ at 88 ° C for 3 hours,

Cooling and filtering the acid. Experiment C I D

«/ Ο P in P ₂ S ₅

Sulfur, weight percent.
Phosphorus, weight percent
Ratio S: Pm

Neutralization

CdO,% of theory

Response time, hours

Maximum reaction temperature, ° C 28.3 28.3 27.8 H ₂ S not by blowing out

21.39

10.20

2.10

110

99 removed with N ₂

20.74 10.27 2.02

110

99

Product ^)

Sulfur, weight percent 12.43 12.79 13.39 13.7 13.1 13.7

Phosphorus, weight percent 6.77 6.74 6.35 6.5 6.5 6.5

Cadmium, weight percent 9.66 10.30 11.80 11.7 11.8 11.8

Neutralization Number (ASTM D-974) 35.5 23.9 6.78 5.58 2.87 5.73

Ratios) 1.84 j 1.90 2.11 2.11 2.02 2.11

Ratio Cd: P (S) 1.43 j 1.53 1.86 1.80 1.82 1.82

(*) Theoretical value 2.07.

( ² ) 75 weight percent cadmium dialkyldithiophosphate in a refined coastal distillate oil with a nominal viscosity of 40 SUS at 98.9 ° C.

( ³ ) Theoretical value 1.81.

20.99 10.14 2.07

110

88

27.2 27.2 26.1 H ₂ S by blowing out with

N ₂ removed

140 5 95.5

120

77

120

4 77

To explain the applicability of lead thiophosphates In the context of the invention, a sample of Blddi-Cg-dithiophosphate (from methyl isobutylcarbinol) produced by double conversion according to the following equation:

RO.

Pb (NOa) ₂ + 2

RO

RO.

RO

* S

S-K

Pb + 2 KNO ₃

10

will. The white powder thus obtained has the following composition:

Pb 25.25 percent by weight

P 7.95 percent by weight

S 16.40 percent by weight

Ratio S: P 2.06 (theoretical

ίο value 2.07)

Ratio Pb: P ... 3.18 (theoretical

Value 3.34)

Neutralization number
according to ASTM D-974 7.42

The dialkyldithiophosphoric acid is prepared by the method described above and with Potassium hydroxide neutralized in methanol. When the neutralization is complete, the methanol is removed from the The resulting Kaliurndialkyldithiophosphat driven off and the product (a white powder) dried. The dried powder is washed by slurrying in hexane and filtered. The washed Powder results in a resinous white precipitate when mixed with aqueous lead nitrate solution, which is filtered off, washed with water and dried

B. Manufacture and properties of lubricating oil blends

Finished lubricating oil mixtures are produced which contain (a) a zinc di (sec.) - C _s / C _e -dithiophosphate, (b) the secondary cadmium di-Cg-dithiophosphate and (c) the primary di-C ₄ / C produced for comparison purposes ₅ dithiophosphate according to Table I. The composition and neutralization numbers of these lubricating oils are given in Table III. The dithiophosphate additives of the lubricating oils (b) and (c) correspond to the above samples No. 5 and No. 2, respectively.

Table III
Neutralization number of cadmium dialkyldithiophosphate-containing lubricating oil mixtures

Mineral oil: (a) Viscosity 60 SUS at 98.9 ° C; (C) 0.35 percent by weight 0.563 weight percent Zinc di-Cs / Qs-dithiophosphate ( ³ ) Viscosity index 105, containing: Cadmimndi-Ce-dithiophosphate 0.03 percent by weight (b) 0.03 percent by weight Cis-oxomercaptoacetic acid 0.563 weight percent Cis-oxomercaptoacetic acid 0.005 percent by weight Cadmium di-C ₄ / C _{5 -dithio-} 0.005 percent by weight Polydimethylsiloxane phosphate Polydimethylsiloxane 0.05 percent by weight Cis-oxomercaptoacetic acid 0.81 0.0005 percent by weight 0.11 Neutralization number Polydimethylsiloxane (ASTM D-974) W. OEP oxidation test - 0.32 0.12 Neutralization number according to of oxidation ' ² I. 0.32

C ¹ ) According to the standard regulations of the US Navy and the Canadian Navy, the upper limit of the neutralization number is 0.2.

( ² ) According to the standard of the British Navy (Admiralty OEP-90), the upper limit of the neutralization number after oxidation is 0.2.

( ³ ) 70 weight percent (secondary) methyl isobutyl carbinol and 30 weight percent (secondary) isopropyl alcohol.

The above table clearly shows that only those with the dithiophosphates to be used according to the invention (i.e. the cadmium compounds derived from secondary alcohols) Lube oils from the United States Navy, Canadian and British Navy Marine turbine lubricating oils meet the requirements with regard to the low neutralization number.

To further explain the improved properties of the lubricating oils according to the invention made the following mixtures with cadmium and lead dithiophosphates. Table IV gives the composition the lubricating oil mixture in percent by weight.

309 533/381

Table IV Lubricating Oil Blends

^ rhmifrni fli Cd-di-Ce-ditniophosphate ( ² ) Pb-di-Ce-dithiophosphate ( ³ ) Cig-oxomercaptoacetic acid Alkenyl succinic acid ( ⁴ I. OI / 1111J.JLC1.UI. I j Weight percent Weight percent Weight percent Weight percent A. 1.00 _ 0.03 B. 1.25 - 0.03 - C. 1.25 - - 0.03 D. 1.50 - - - 0.035 E. - 0.85 0.03 -

C) The oil base is a mineral oil obtained from a midcontinent crude oil (viscosity at 98.9 ° C = 60 SUS, viscosity index 104.8, specific weight 0.8751, flash point 252 ° C) with a content of 0.0005 percent by weight dimethyl silicone .

( ² ) Mixture of equal proportions of samples 2 and 3 according to Table I, concentration in the oil 75 percent by weight.

( ³ ) Made by double conversion.

(i) The alkenyl group contains an average of about 16 to 18 carbon atoms. The lubricating oil mixtures given in Table IV are tested according to Tables V and VI.

Table V Characteristics of the lubricating oils

AW BW CP) DW E ( ¹ I Requirements according to USA marine standard MIL-L-17331A Resistance to oxidation 2000+ 2000+ 2000+ 2000+ 2000+ according to ASTM D-943, hours ... 0.12 0.13 0.16 0.12 0.13 min. 1000 Neutralization number (ASTM D-974) max. 0.20 Copper strip corrosion ® enough enough enough enough enough 3 hours at 100 ° C enough enough OO
enough enough enough 1 weak start-up 3 hours at 121 ° C 0 (15) O "O
1 (15) OO
0 (15) OO
3 (15) OO
0 (10) j or discoloration allowed Emulsion test at 54.5 ° C ' ³ ) max. 3 ecm foam 131 139 149 99 147 cuff (30 minutes) Emulsification with steam ( ⁴ > three track no no more moderate - Seawater rust test® rust rust rust rust no rust stains 623 814 698 659 436 Ryder gear test, load (3490) (4560) (3910) (3690) (2720) 393 (Mean) (β) kg / cm (Ibs / inch) (2200)

0 Exam interrupted after more than 2000 hours.

(2) ASTM D-130.

( ³ ) Vy-L-791, Method No. 3201. 5 ecm emulsion (time in minutes).

( ⁴ ) ASTMD-157-51T.

( ⁵ ) ASTM D-665.

( ^e ) Wright Air Development Center, Detailed Handbook on Test Procedures in Support of Turbojet and Turboprop Lubes.

Table VI Test results for lubricating oils A and B according to laboratory test OEP-90

A. B. Requirements
according to OEP-90 193 196 min.165.5 82.62
9.76
105
-3.9
0 82.61
9.72
104
-9.5
0 82 to 92
min. 8.2
50
max. -6.7
0 number 1
number 1
weak number 1
number 1
weak No. 1 or better
no limit
no rust 0.04; 0.03
150
44.5 (98) 0.01; 0.02
195
50.8 (112) max. 0.20
max. 300
40.8 (90 *)

Flash point (closed container), ⁰ C

viscosity

at 37.8 ° C

at 98.9 ° C

Viscosity index

Pour point, ⁰ C

Acidity, inorganic

Copper streak corrosion

at 100 ^° C

at 121 ° C

Seawater rust test

Resistance to oxidation

Neutralization number after oxidation

De-emulsifiability number

IAE gear test, load, kg 0bs)

* Canadian marine regulations also require 90.

The OEP-90 standard specified in Table VI is that required by the British Admiralty Marine standard for turbine oils.

Tables V and VI clearly show the high pressure absorption capacity and the low neutralization number of the lubricating oils according to the invention and their resistance to oxidation and corrosion-inhibiting Properties. A comparison of the results of the seawater rust test in Tables V and VI shows that alkenylsuccinic acid imparts somewhat better rust inhibiting properties to lubricating oils.

Claims (4)

PATENT CLAIMS: 1. Turbine lubricating oil containing a metal salt of a dialkyldithiophosphoric acid with alkyl groups derived from secondary alcohols, characterized in that it is a cadmium or lead salt of a dialkyldithiophosphoric acid with 9 to 24 carbon atoms in the molecule, in which all alkyl groups are derived from secondary alcohols, in quantities from 0.20 to 3.0 percent by weight, based on the total amount of the lubricating oil mixture. 2. turbine lubricating oil according to claim 1, characterized in that it is also used as an known corrosion retardant is a mercaptoacetic acid with 9 to 17 carbon atoms per alkyl group or an alkenylsuccinic acid of the formula R-CH -COOH CH ₂ - COOH in which R is an unsaturated aliphatic radical with about 10 to 22 carbon atoms, in amounts of 0.005 to 0.5 percent by weight, based on the total amount of the lubricating oil mixture, contains. 3. turbine lubricating oil according to claim 2, characterized in that in the alkenylsuccinic acid R is an unsaturated aliphatic radical containing about 14 to 18 carbon atoms and this alkenylsuccinic acid in amounts of 0.01 to 0.10 percent by weight, based on on the total amount of the lubricating oil mixture contained in the lubricating oil. 4. turbine lubricating oil according to claim 1 and 2, characterized in that the corrosion retarder a branched chain alkylcaptoacetic acid with 13 carbon atoms per alkyl group is. Considered publications:
German Patent Nos. 964 649, 962 466;
German Auslegeschrift No. 1035 833;
U.S. Patent Nos. 2,838,555, 2,775,560;
British Patent No. 736,438. 1 sheet of drawings © 309 538/381 2.