DE2060750C3 - Synthetic ester lubricating oil - Google Patents

Description

organic monocarboxylic acids with 2 to
18 carbon atoms, _I0
(2) 0 3 to 5 percent by weight of an alkyl or
Alkarylphenylnaphthylamine, the alkyl radical of which has 4 to 12 carbon atoms, ^ u ₆ > »· ._ _t

"Sssrsssss -. *. Ige * rÄ» esis

lenwasserstoffphosphats whose hydrocar- _2Q "-naphthylamm, (2)" nen ^ or _Saiz

2. Synthetic ester lubricant according to claim 1, 25 ^^ c ^ Tphosphorus ester in the form of a phosphate JShtep ^ cienrSShSyli.-n'iphtiiylaiiin or or Phosphta. ^^ 3 _{414 618 we} rden contains oxy-./i-naphthylamine, antagonists to Use in synthetic

3. Synthetic ester - lubricating oil described according to _An ^{^^ ° ™ m} rölen, the additives from saying 1, characterized in that it contains 0.5 to 30 gJJ ™ ^ _lk , _pheny lna _P hthylamine {θ weight percent contains dioctyldiphenylamine. Group oer α yy _{invention is a} synthetic one

4. Synthetic ester - lubricating oil according to an <**% £ , _{consisting of}

res. ™ Ä _y i ™ i ° ^e * sr ₂ .sTs ₅ «,» * -, - s.% *

percent dioctyldiphenylamine and 2.0 wt _.- ^ Alkary i _p henylnaphthylamins, whose alkyl radical is 4

rrgäsät & ixssL * ^ _A ". ₃ . g ätssssÄ ""_{"AES ny;}

Claim 1, characterized in that it is an _amine , the alkyl radicals of which are 4 to 12 carbon atoms

SÄK SSToSÜl-SSÄS « ₄ . SSW. G ^ sprcn, a PCyhydro », - contains acids with about 5 to 10 carbon atoms. anthraquinones and κ “hl ™

Esler base oil is a product of the conversion of _muppe " _ms alkyl", aryl-alka yl ^ tycloa I

»^ Ri'aSän ^ ctr. Α "SÄ '-Ä ^^ TSeÄäe ^ and pelargonic acids are built up with an average.

Carbon chain length of 6 to 7 carbon atoms shows lubricating oil according to the invention in relation to

contains. Soiling inhibition, corrosion protection

rostSrn steel and heat and oxidation resistance Blessing progressive effects compared

The invention relates to a lubricating oil for Vcrwen- ^ Η ^ ΓΑ ^^ ^syn '

dung in gas turbine or jet engines. Turbine 60 jg ^^^ mlrölgemisches based on ester. D.e

Under extreme global conditions, engines have to _surprise and un-

work and produce during the occupation in the ^ ". ss _{an excellent} trade

Inside the engine temperatures of 204 to 260 C ^ arte ^ ais ^ ester lubricating oil obtained

and more. These operating conditions burden wie- ghchen synmei ^ ^ ^

on the other hand the lubricating oil is very strong, so that even 6 ₅ results _{each time and carefully}

best lubricating oil compositions »» f mineral oil- J ^ JJ. ^ ¹ lubricating oil composition was achieved

base not to be used for turbine engines ^ "f" ^, composition no such

can.

Contains additive that is considered essential for the production of the above-mentioned, well-established synthetic lubricating oil.
The main component of the lubricating oil according to the invention consists of a liquid ester prepared from pentaerythritol or irimethylolpropane and a mixture of hydrocarbon monocarboxylic acids. Polypentaerythrites such as B. Di-, Triiind tetrapentaerythritol can be used to produce the base oil.

r: For the production of the liquid ester you can the following hydrocarbon monocarboxylic acids are used: straight and branched chain aliphatic « Acids, cycloaliphatic acids and aromatic acids and their mixtures. The used Acids have 2 to 18, preferably 5 to 10, carbon atoms per molecule. Suitable specific acids are e.g. B. vinegar, propion, butter, valerian, isovalerian, capron, Decane, hexadecane, vinylbenzoic, dodecylbenzoic, pelargon, cyclohexane, naphthenic, benzoin, Phenyl acetic, tert-butyl acetic and 2-ethylhexanoic acids.

In general, the acids in such Relation to each other implemented that the end product is a fully esterified pentaerythritol or trimethylolpropane in which the pentaerythritol tetraesters form the preferred ester bases. One in the trade available tetraester is z. B. pentaerythritol tetracapronate, that of purified pentaerythritol and an untreated, still other monobasic acids with 5 to IOC atoms containing caproic acid is produced. A tetraester is also suitable, the one from a technical pentaerythritol and a 38% valerian, 13% 2-methylpentane, 32% Octane and 17% pelargonic acid containing mixture is produced. Further suitable ester bases are 3s Trimethylolpropane - triheptanate, trimethylolpropane pentanate, and trimethylolpropane hexanate.

The ester constitutes the major part of the ready-to-use synthetic lubricating oil. In general this liquid ester is present in the lubricating oil in 90 to 98% concentration.

The alkyl or alkarylphenylnaphthylamine component of the lubricating oil of the invention is represented by the following general formula:

Compounds of these ari are by the formula H

45

50

In this formula, R denotes an alkyl or alkaryl radical having 4 to ^ C atoms. This radical can be a straight-chain or branched-chain alkyl radical, preference being given to the tert-alkyl structure, or it can be an alkaryl radical. The naphthylamine can be either u- or / i-naphthylamine. Specific suitable compounds from this group are, for. B. Npt.-octylphenyl-fi-naphthylamine, N- (p - «- cumylphenyO-o-ii-cumyl-ß-naphthylamine, NpL-octylphenyl- β -naphthylamine and the corresponding pt-dodecylphenyl-, pt-butylphenyl - as well as p-dodecylphenyl - «- and - ^ - naphthylamines This component is preferably used in a concentration of about 0.5 to 2.5 percent by weight.

Another important component of the inventive Lubricating oil is the dialkyldiphynylamine.

^ O)

characterized in which R is an alkyl radical with about 4 to 12 carbon atoms. To the suitable alkylamines include dioctylphenylamine, didecyldiphenylamine, didodecyldiphenylamine. Dihexyldiphenylamine and similar other compounds. Dioctyldiphenylamine is preferred, and preferably in a concentration of 0.5 to 2.0 percent by weight.

A polyhydroxyanthraquinone is used as the essential metal inactivating agent in the lubricating oil according to the invention used. Suitable compounds from the group of polyhydroxyanthraquinones are dihydroxyanthraquinone such as 1,4-dihydroxyanthraquinone, also known as quinizarin, 1,5-dihydroxyanthraquinone and 1,8-dihydroxyanthraquinone as well as the higher polyhydroxyanthraquinones. This component is preferred used in a concentration of about 0.01 to 0.5 percent by weight.

The last specific component of the lubricating oil according to the invention is a hydrocarbyl phosphate ester, to be more precise, a trihydrocarbyl phosphate, in which the hydrocarbyl radical is an alkyl, Aryl, alkaryl, cycloalkyl or aralkyl radical or a mixture thereof with 2 to 12, preferably 4 to 8 carbon atoms. Appropriate specific compounds are tricresyl phosphate, cresyl diphenyl phosphate Triphenyl phosphate, tributyl phosphate, tri - (2 - ethylhexyl) phosphate and tricyclohexyl phosphate. These compounds are preferably used in the lubricating oil composition in one concentration used from about 0.5 to 5 percent by weight. The lubricating oil according to the invention was now after the 1.5 Erdco-Bearing-Test described below and the Erdco-Screening-Test, of which the first information about its resistance to oxidation and corrosion and the latter about the Should give anti-pollution as well as heat resistance.

The oxidation and corrosion tests, apart from the deviations specified under MIL-L-23 699 B, are carried out in accordance with method No. 5308.4 of the Federal Test Method and Standard No. 791a (US Test and standard regulations) for 72 hours at 204 ⁰ C or for 72 hours at 218.3 ° C. The bath temperature is maintained at 204 and 218.3 ° C ± 0.55 ° C, instead of 121.1 ° C, and the tests last 72 hours instead of the originally prescribed 168 hours.

In the Erdco screening test used to test lubricating oil, an oil sample is checked under controlled conditions Conditions for a prescribed period of time in one ventilated and one heated Test chamber containing aluminum tube circulated. After completing the test, three larger ones are made Parties of the aluminum tube checked for contamination, and any buildup or staining is recorded and graded with a numerical value, so that afterwards you can get an overall grade the lack is maddening.

IO

This experiment is based primarily on that under No. 5003 of the US Standard Requirements for Test Procedures described Wright Air Development Center Deposition Test Rig (test facility for Testing of contamination), although the system is modified as follows:

1. An aluminum tube 88.9 cm long and 0.477 cm in diameter was used in place of the filter used

2. Ah place of the filling bottle was one with graduation marks provided replacement container used.

3. The oil cooler was only used to cool the oil after the end of the experiment.

4. The oil temperature controller was not used.

5. The filter pressure meter has been switched off.

The sleeve-shaped heated end of the coking tube is mounted on by means of a clamping device and rotates at a speed of 1700 to 1800 rpm. All debris on the pipe are removed with # 400 silicon carbide paper, and then the tube is still with wiped with a soft, clean cloth. The air flow is adjusted so that at normal pressure and at a temperature of 48.9 ± 2.8 ° C, 300 ml of saturated air flow in per minute; the heat regulator is adjusted to 273.9 ° C.

After the apparatus has been rinsed with oil for 10 minutes, the container filled up to the 100 ml graduation with fresh oil. The oil level in the coking vessel is approximate Held 12.7 mm above the bottom of the glass.

The experiment is carried out as follows: The coking pipe is heated up and the regulator is open 149 ° C set. This temperature becomes over 5 minutes and then set the controller to 204 ° C. After the same dwell time at At this temperature the controller is then set to 316 ° C. According to the warming and expansion of the oil must be drained of the latter so much that the oil level is between 5.08 and 1.27 cm above the bottom of the glass coking vessel is cooled. By the oven temperature and the above-mentioned correct level of the oil that covers the coking pipe become uniform Maintain thermal conditions. New oil is fed in according to the evaporation, to maintain the correct oil level. After a test duration of 6 hours, the coking stirrer heating is activated turned off, the water cooler switched on and the oil to a temperature of 121.1 ° C let cool down. All switches as well as the water and air supply are switched off.

After about an 18 hour break, the experiment is restarted and left exactly as the first time under the normal test conditions run a further 6 hours. (Possible you have to refill 5 to 10 ml of new oil to bring the oil level back to about 12.7 mm above the Bring the bottom of the glass coking vessel.) After this second heating period is over The heating is turned off again, the oil is allowed to cool and the air supply is stopped. The feed oil is drained and the coking tube is removed from the coking hood. One dodges it in n-pentane until all visible traces of oil have disappeared; then the pipe is then air dried.

The coking tube is just like it was in the coking vessel was taken on the side facing the vent. For determination a template with lines at a distance of 12.7 mm over the main areas is used to determine the deficiency marks with the lines corresponding to the values 25.4 and 12.7 mm at the interface between Steam and oil are applied.

For each 12.7 mm segment, the type and Thickness of the deposits on the inspected areas graded with a numerical value If the deposits vary within a segment, take the highest number. For each of the three main areas graded a weighted factor is determined to take into account the relative importance of the individual areas. The total deposit rating is obtained by summarizing the deposits on the major surfaces and multiplied by the weighted factor. The sum of three area defects, divided by 2, gives the overall deposition grade.

The following table shows the standard grades for the coking tube:

coating or stain ...

money

smooth

rippling

blistered

scaly

Type of deposit

Easy

12th
15th
18th

middle

10
13th
1.6
19th

Strong

11th
14th
17th
20th

It turned out that the test results could be reproduced well and also with the data that obtained with the 1.5 Erdco-Bearing test for coating and carbon formation, agree well.

The base oil A contained in the lubricating oils tested below was a technical grade pentaerythritol with a small amount of dipentaerythritol, which contains (in mol%) about 38% valerian, 13% 2-methylpentane, 32% n-octene and 17% pelargonic acid containing fatty acid mixture was esterified, the average carbon chain length was about 6.5. This base oil had the following properties:

Viscosity,

cSt at 98.9 ° C 4.93

cSt at 37.8 ° C 25.6

cSt at -40 ° C 7023

Viscosity index 131

Flash point, ° C 254

Ryder Gear, kg / cm 364.63

Base oil B was a technical grade pentaerythritol, which with a (in mole percent) approximately Containing 12% isovaleric, 27% valerian, 8% caproic, 14% heptylic, 19% caprylic and 13% pelargonic acid Fatty acid mixture was esterified.

The base oil C was a technical pentaerythritol, which with a (in mol percent) about 8% isovalerian-, 23% Valerian, 20% Capron, 27% Heptyl, 7%

Caprylic and 16% pelargonic acid containing fatty acid mixture was esterified.

The composition of the lubricating oils according to the invention and the comparison oils and the results the oxidation and corrosion tests are given in Table 1 below. The lubricating oils E, G, H and I have been made according to the invention.

The base oil D was a technical pentaerythritol, which with a (in mol percent) about 18% isovalerian, 39% valerian, 2% caprylic and 40% pelargonic acid containing fatty acid mixture was esterified.

• Table I Synthetic lubricating oil Oil Β ¹ '

oil C ¹ :

Basic fluid

A.

B.

C.

D.

N-phenyl-a-naphthylamine

N- (p, t-octylphenyl) -a-naphthylamine

p, p'-di-t.-octyldiphenylamine

Tricresyl phosphate

Quinizarin

N- (p-t-octylphenyl) - /? - naphthylamine Oxidation / corrosion (temperature,

° C / time)

Corrosion (mg / cm ² )

Cu

Fe

Al

Mg

Ag

Ti

Ti

Increase in kin. Viscosity,% (at

37.8 ° C)

Increase in the total acid number of sludge (g / 100 ml)

96.9

1.50 1.00

0.10

204 /
72 hours

-0.06
0

-0Λ3
-0.03
-0.02

20th
0.63
0.0092

218.3 / 72 hours

0 0

0 0

103 9.77 0.0033

oil D ¹ )

Synthetic lubricating oil

oil E ¹ ]

oil F ² ) (commercially available ester oil)

Basic fluid

A.

B.

C.

D.

N-phenyl-a-naphthylamine

N- (p, t-octylphenyl) -a-naphthylamine

ρ, ρ'-di-t.-octyidiphenylamine

Tricresyl phosphate

Quinizarin

95.0 94.9

1.50 1.00 2.00 1.50
1.00
2.00
0.10

') These oils contained, among other things, an addition of 50 ppm of dimethyl silicone to prevent foam formation and 0.50 percent by weight of bis (2,2,4-trimethylpentyl) ester of a commercially available linoleic acid dimer.

^a ) A commercially available oil with an additional component consisting of 0.10% aliphatic! Carboxylic acid salt of 1-salicylalaminoeuanidihs with 14 to 18 carbon atoms.

continuation

ίο

Synlhelic lubricating oil

Ol D ¹ !

Ol E ¹ )

Ol F ² ) (commercially available ester oil)

N- (p-t-octylphenyl) - / 3-naphthylamine Oxidation / corrosion (temperature, ° C / time)

Corrosion (mg / cm ² )

Cu

Fe

Al

Mg

Ag

Ti

Ti

Increase in kin. Viscosity,% (at

37.8 ⁰ C)

Increase in total acid number .... sludge (g / 100 ml)

204 / 72h

-0.46

0 -0.03

24.2 1.26 0.0036

204/72 hours

0.

19 1.67 0.0041

218.3 / hour

0 +0.04

-0.02

40 4.5 0.0096

204 / hour

-0.06 0 0 0 0

21.0 0.98 0.009

218.3 / 72 hours

+0.06 0

+0.03 +0.04

52.0 5.03 0.024

Table I (continued)

Ol G

Synthetic lubricating oil

Ol H

Ol Γ)

Basic fluid

A.

B.

C.

N-phenyl-a-naphthylamine

N- (p, t-octylphenyl) -a-naphthylamine.

ρ, ρ'-di-t.-octyldiphenylamine

Tricresyl phosphate

Quinizarin

N- (p-t-octylphenyl) -0-naphthylamine. Oxidation / corrosion (temperature,

° C / time)

Corrosion (mg / cm ² )

Cu

Fe

Al

Mg

Ag

Ti

Ti

Increase in kin. Viscosity,% (at

37.8 ° C)

Increase in the total acid number

Sludge (g / 100 ml)

95.4

1.50 1.00 2.00 0.10

204/72 hours

-0.07 +0.02

0 +0.02

19.0 0.88 0.001

95.4

1.50 1.00 2.00 0.10

204/72 hours

-0.04 +0.04

21.0 0.89 0.001

94.9

1.00 2.00 0.10 1.50

204 / hour

+0.08 +0.06 +0.05 +0.04 +0.06

20 0.74 0.0034

MIL-L-23 699B regulation

204 / hour

± 0.4 ± 0.2 ± 0.2 ± 0.2 ± 0.2

-5 to + 25

max. 0.050 max.

218.3 / 72 hours

± 0.2 ± 0.2

± 0.2 ± 0.2

-5 to +51

6 max. 0.050 max

■) These oils contained, inter alia, an addition of 50 ppm dimethylsilicon to prevent Schanmhildnp at 0 50 C percent by weight bis (2,2,4-trimethylpentyl) ester of a commercially available linoleic acid dimer. ^{mnaerune of} foaming and 0.501

² ) A commercially available oil with an additional component consisting of 0.10% aliphatic carboxylic acid salt of l-salicylalamir • uanidine with 14 to 18 carbon atoms. · '

The military requirements for the oxidation and corrosion tests are determined by the Lubricating oils A, B, C and D mainly due to their very low viscosity and lack of stability against acid formation not met, oil A also does not meet the requirements with regard to corrosion with copper and magnesium. These oils represent the critical benchmark for the four additional components of the oil according to the invention. The lubricating oils E, G, H and I are examples of those according to the invention Lubricating oils and are an excellent commercial synthetic ester lubricating oil in their performance either the same or superior:

The anti-soiling features were on the one hand in the ester lubricating oil according to the invention and a commercially available synthetic ester lubricating oil in the aforementioned Erdco-Screening-Test as well as comparatively tested in the 1.5 Erdco-Bearing-Test. The results are in the following Table II reproduced:

Table II Soil Inhibition

Erdco screening test
Deposit note ..

Erdco-Bearing-Test, Art 1.5
Deposit note

Viscosity increase in percent.
Total Acid Number Increase,%

THE DlF DlG DlH DlI 19th 40 21 29 31 17th 62 23 23 41 21 28 21 23 18th 1.1 1.4 1.1 1.3 1.3

MIL-L-23 699B regulation

80 max.

-5 to +30

2 max.

All lubricating oils composed according to this invention meet the aforementioned military requirements. They even received better marks than a commercially available ester lubricating oil, namely lubricating oil F.

The lubricating oils C and E and a commercially available ester lubricating oil were tested and compared according to the so-called "410 Stainless Steel Corrosion Test", a corrosion test on stainless steel. For this test, 25.4 152.4 χ 0.318 mm plates were made from stainless steel sheet; the steel sheet corresponded to standard 410 from specification no. 5504 for missile material and had a Brinell hardness of about B 76 and a surface quality of 2 D. Two of the test plates were weighed to the nearest 0.1 mg and then weighed together with 65 ml of the oil to be tested introduced into a nickel autoclave. The oil in the autoclave was heated to 260 ° C. and this temperature was maintained for 72 hours. The oil was then allowed to cool to room temperature and 5 ml were withdrawn to determine the total acid number. The autoclave was then heated again to 260 ° C. and this temperature was maintained for a further 72 hours. The autoclave was then allowed to cool again, the plates were cleaned and weighed to the nearest 0.1 mg. The viscosity of the oil at 37.8 ° C. and the total acid number were determined. The results are given in Table III below. Table III
Corrosion protection with stainless steel, standard 410

1. Weight loss, weight loss, mg

2. Weight loss, weight loss, mg

Total acid number, increase in percent ...

260 ° ΟΊ44 hours

Lubricating oil

15th
19th
9.55

Lubricating oil

171
97
32.91

Commercially available ester oil F

This test shows that the lubricating oil according to the invention in terms of corrosion resistance Stainless steel of the standard 410, a commercially available oil and a similar oil without tricresyl phosphate is substantially superior.

From the tests described it can be seen that the lubricating oil according to the invention has excellent resistance to oxidation, Has anti-corrosion and anti-pollution properties. The lubricating oil E meets the requirements of military regulations U.S. Navy MIL-L-23 699 B and those too Pratt / Whitney Aircraft 521B. There: the same applies to oils G and H.

Claims (1)

¹ c, are used to lubricate turbine engines u t cvnSedsche ester lubricating oils with good success Claims: ready, _see balanced mixture used cue _{n These ester} oils remain within 1 Synthetic ester lubricating oil comprising from ^to ^ f ⁿ _Rossen temperature range operable (1) eLm reaction product of pentaerythritol * * SÄ ^^ aSÄi