DE1278662B - Ester lubricating oil - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

German class:

Number:
File number:
Registration date:
Display day:

ClOm

P 12 78 662.8-43 (S 100877)

December 9, 1965

26th September 1968

It is known from US Pat. No. 2,930,758, mixtures of amines, ζ. B. from diphenylamine and Naphthylamine to add lubricating oils. However, the antioxidant effect that can be achieved has in the Practice not yet fully satisfied.

It has now been found that, in contrast, the properties of the ester lubricating oils improve further if you have an ester oil a mixture of diphenylamine and a dipyridylamine as an antioxidant admits.

This improvement compared to the combination known from US Pat. No. 2,930,758 of diphenylamine and phenyl-a-naphthylamine shown in Table I below.

The ester oil can be a reaction product of a monohydric alcohol and a monocarboxylic acid at least one monohydric alcohol and one polybasic carboxylic acid or of a polyhydric one Alcohol and at least one monocarboxylic acid. The ester base oil preferably consists of an ester, which is a reaction product of a monohydric alcohol and a polybasic carboxylic acid or a polyhydric Alcohol and a monocarboxylic acid. Furthermore, an ester base oil is preferred which is composed of a Mixture of esters consists, the ester reaction products of a polyhydric alcohol and a or more monocarboxylic acids.

The esters can be derived from aliphatic, monohydric alcohols having 1 to 20 carbon atoms or from aliphatic polyhydric alcohols having 2 to 20 carbon atoms and preferably three, four or six Derive hydroxyl groups. Furthermore, the esters of aliphatic monocarboxylic acids can with 3 to 20 carbon atoms or of aliphatic polybasic carboxylic acids having 3 to 20 carbon atoms and preferably derive from two carboxyl groups.

A preferred ester base oil consists of a mixture of bis (2,2,4-trimethylpentyl) azelate and 1,1,1-trimethylpropane triheptanoate. Ester mixtures which consist of reaction products of pentaerythritol and aliphatic C ₅ -C ₉ monocarboxylic acids or reaction products of dipentaerythritol and aliphatic C ₅ -C ₁₀ monocarboxylic acids are also preferred as ester base oils.

As monohydric alcohols are used for the production of Ester base oils e.g. B. methyl, butyl, isooctyl, dodecyl and octadecyl alcohols are suitable. Likewise, »Oxo« - Suitable alcohols obtained by reacting olefins with carbon monoxide and hydrogen. Preferably neoalcohols (i.e. alcohols which do not have hydrogen atoms on the / ^ - carbon atom) Ester lubricating oil

Applicant:

Shell International Research

Maatschappij, N.V., The Hague

Representative:

Dr. E. Jung and Dr. V. Vossius, patent attorneys,
8000 Munich 23, Siegesstr. 26th

Named as inventor:

Kenneth Terry Wendler, Alton, JIL;

Robert Cleve Spillman, Norwalk, Conn .;

Hans Low, East Alton, JIL;

James Richard Price, Alton, JlL (V. St. A.)

Claimed priority:
V. St. v. America December 11, 1964
(417 818)

used. Examples of these alcohols are 2,2,4-trimethylpentanol-1 and 2,2-dimethylpropanol.

The polyhydric alcohols suitable for preparing the ester base oils preferably contain 1 to Carbon atoms. Mixtures of alcohol can also be used. Examples of multi-valued Alcohols are dihydric alcohols, e.g. B. 2-ethyl-1,3-hexanediol, 2-propyl-3,5-heptanediol, 2-butyl-1,3-butanediol, 2,4-dimesityl-1,3, 3-butanediol and polypropylene glycol with molecular weights of about 100 to 300. However, alcohols with three, four, five, six or more hydroxyl groups are used per molecule. Examples of these polyols are pentaerythritol, Dipentaerythritol and trimethylol propane.

Aliphatic mono- and dicarboxylic acids are suitable as carboxylic acids for the production of the ester base oils (Alkane and alkane dicarboxylic acids). Examples of these acids are vinegar, propionic, butter, valerian, Capron, caprine, laurine, palmitine, oxal, malon, amber, glutar, adipine, diethyl adipine,

809 618/497

Pimeline, cork, ethyl cork, azelaic, sebacic, pentadecanedicarboxylic acid, Diglycolic and thiodiglycolic acid and mixtures thereof. Glutaric acid, adipic acid, azelaic acid and their Mixtures used. E.

Examples of specific ester base oils are ethyl palmitate, Ethyl laurate, butyl stearate, di- (2-ethylhexyl) sebacate, di- (2-ethylhexyl) azelate, ethylglygoldilaurate, Di (2-ethylhexyl) phthalate, di (1,3-methylbutyl) adipate, di (1-ethylpropyl) azelate; Diisopropyloxylate, di- ία cyclohexyl sebacate, glycerine tri-n-heptoate, di (undecyl) azelate and tetraethylene glycol di (2-ethylene caproate) and their mixtures. A preferred ester mixture consists of about 50 to 80 percent by weight bis (2,2,4-trimethylpentyl) azelate and 50 to 20 weight percent 1,1,1-trimethylyl propane triheptanoate.

Ester base oils consisting of esters of monocarboxylic acids having 3 to 20, in particular 3 to 12 carbon atoms and polyhydric alcohols such as pentaerythritol, dipentaerythritol and trimethylolpropane are also preferred. Examples of these esters are pentaerythrityl-butyrate, pentaerythrityl-tetrabutyrate, pentaerythrityl tetravalerat, pentaerythrityl tetracaproat, pentaerythrityl dibutyratdicaproat, pentaerythrityl butyratcaproatdivalerat, pentaerythrityl butyrattrivalerat, pentaerythrityl butyrattricaproat, pentaerythrityl tributyratcaproat, mixed, saturated C ₄ -C ₁₀ - fatty acid ester of pentaerythritol, Dipentaerythrityl-hexavalerat, Dipentaerythrityl-hexacaproa ^ Dipentaerythrityl-hexaheptoat, Dipentaerythrityl-hexacaprylat, Dipentaerythrityl-tributyratcaproat, Dipentaerythrityl-trivalerattrinonylat, mixed Dipentaerythrityl-hexaester of C ₄ -C ₁₀ fatty acids and Trimethylolpropanheptylat. The pentaerythrityl esters of mixtures of C ₄ -C ₁₂ fatty acids are excellent base oils.

The lubricating oil can be 0.01 to 5, preferably 0.1 to 3 weight percent of the dipyridylamine, based on the weight of the lubricant. An unsubstituted dipyridylamine is preferably used, z. B. 2,2'-dipyridylamine or 4,4'-dipyridylamine.

The lubricant mixture according to the invention can also contain other additives, e.g. B. Extreme pressure additives, viscosity improvers or anti-corrosion agents.

Weight additives percent

Diphenylamine

2,2'-dipyridylamine 0.5

Salt of mixed, primary C ₁₈ -C ₂₂ -tert. Alkylamines and monochloromethylphosphonic acid (hereinafter referred to as "M / J" salt) 0.2

100

Example 2

Composition of Example 1 + 0.0075 percent by weight Cu-dibutyldithiocarbamate + 0.02 percent by weight azelaic acid + 0.001% of a silicone oil with a viscosity of 1000 cSt

Example 3

60 weight percent bis (2,2,4-trimethylpentyl) azelate

40 percent by weight 1,1,1-trimethylpropane triheptanoate

Additives

Diphenylamine

2,2'-dipyridylamine

M / J salt of Example 1

97.8

100

Example 4

Base oil

100 percent by weight diisooctyl azelate additives

Diphenylamine

2,2'-dipyridylamine

40 percent by weight

98.5

100

example 1

Base oil

60 weight percent C ₅ -C 8 aliphatic monocarboxylic acid esters of pentaerythritol

40 percent by weight of aliphatic C ₅ -C ₁ (, monocarboxylic acid esters of di-

Weight percent

98.3

pentaerythritol

In order to show the oxidation stability of the lubricant mixtures according to the invention, samples are used the lubricants according to the invention and known lubricants carried out air oxidation tests.

The test is ^{carried out at 232 °} C. by passing an air stream at a rate of 70 ml / min through 20 g of lubricant samples. In all tests, 0.002% iron and copper in the form of octoates are used as catalysts.

The oxidation stability is determined by the length of time (the so-called induction period) that passes before the rate of oxygen absorption taking place increases significantly. The induction periods for the air oxidation tests are given in Table I below.

. Table I.

test Base oil Additives, percent by weight Induction period
hours 1
2
3
4th
5
6th
7th Base "A" (a) 1.0 phenyl-a-naphthylamine (abbreviated PAN)
1.0 diphenylamine (abbreviated DPA)
0.5 2,2'-dipyridylamine (abbreviated 22 DPA)
0.2 M / J (c)
1.0 PAN + 0.5 22 DPA
1.0 DPA + 0.5 22 DPA
0.5 22 DPA + 0 _s 2 M / Y 1
3
1
0
4th
12th
4th

Table I (continued)

test Base oil Additives, percent by weight Induction period
hours 8th
9
10
11
12th
13th
14th Base "A" (a)
Base "B" (b) 1.0 PAN + 0.5 22 DPA + 0.2 M / Y
1.0 DPA + 0.5 22 DPA + 0.2 M / Y
1.0 PAN + 0.5 22 DPA
1.0 DPA + 0.5 22 DPA
1.0 PAN - + 0.2 M / y
1.0 PAN + 0.5 22 DPA + 0.2 M / Y
1.0 DPA + 0.5 22 DPA + 0.2 M / Y 7th
24
3
5
5
4th
16

( ^a ) Pentaerythritol tetraesters of mixed aliphatic C ₅ -C ₉ monocarboxylic acids (ie of mixed C ₅ -C ₉ alkanoic acids). C) 67 percent by weight of the base "A" + 33 percent by weight dipentaerythritol hexaester of mixed aliphatic C ₆ -Ci ₀ -

Monocarboxylic acids (ie of mixed Q-Cio alkanoic acids).
(°) High pressure agent, consisting of a mixed salt of monochloromethylphosphonic acid and primary Ci _e -C _aa -tert.

Alkylamines.

A comparison of experiments 1 to 4 shows that no additive in itself has a significant antioxidant effect exercises. The phosphonic acid salt also has practically no antioxidant effect. From the experiments 5, 6, 10 and 11 shows that the lubricant mixtures according to the invention, when in the presence Soluble metals tested have a far greater antioxidant effect than PAN and 2,2-dipyridylaniine exercise together. Experiments 7 to 9 and 12 to 14 show that the oxidation stability of the Lubricant mixtures according to the invention increased even further in the presence of the phosphonic acid salts and is not adversely affected as would have been expected.

Example 6

35

40

In addition to the air oxidation tests according to Example 5, the lubricant mixture according to the invention is compared with a known lubricant, the Pratt and Whitney Bearing Test II carried out.

The lubricants are identical per se, except that the lubricant according to the invention contains 1 percent by weight diphenylamine, while the known lubricant contains 1 percent by weight phenyl-a-naphthylamine. The base oil consists in each case of a mixture of 67 percent by weight of pentaerythritol tetraesters of aliphatic mixed C ₅ -C ₉ monocarboxylic acids (i.e. mixed C ₅ -C ₉ alkanoic acids) and 33 percent by weight of dipentaerythritol hexaesters of aliphatic mixed C _{6 -C 10} - Monocarboxylic acids (ie mixed C ₅ -C ₁₀ alkanoic acids).

The Pratt and Whitney Type II Bearing Test is performed as the final method of evaluating the high temperature properties of synthetic lubricants prior to testing in the jet engine. A circulating oil system and a 100 mm test bearing, which is the same as the bearings used in jet engines, are used for the test. The test lasts 100 hours, and is carried out at temperatures of 227 ⁰ C in the tank 204 ⁰ C and 26O ⁰ C in the oil in the bearing. During the test, the storage chamber is saturated with air at an amount of 0.0084 to 0.0098 m ³ / min. and flushed together with the test oil to a 9-1 test oil tank. The behavior of the oil is assessed with regard to the deposits obtained, the increase in the acid number and the viscosity.

Table II

Additives, percent by weight

PAN

2,2'-dipyridylamine

Diphenylamine

M / J

Copper dibutyldithiocarbamate ..

Silicone oil with a viscosity

from 1000 cSt,%

Type 2 bearing test results

Deposits, damage grading

camp

All in all

Filter sludge (total)

Acid number; no increase ..
Viscosity increase (37.8 ⁰ C) ° / ₀

Mixture I.

, 0 + 0.5

+ 0.2 + 0.0075

+ 0.001

42

84 3.5 6.1 215

Mixture H

+ 0.5 + 1.0 + 0.2 + 0.0075

+ 0.001

25 73 2.0 6.8 211

Table II shows that the lubricant of the present invention had significantly less sludge formation and deposits compared to the known lubricant.

Claims (1)

Claim: Ester lubricating oil containing a mixture of two amines, characterized in that that it contains a mixture of diphenylamine and a dipyridylamine. References considered: U.S. Patent No. 2,930,758. 809 618/497 9.68 © Bundesdruckerei Berlin