DE1297796B - Grease - Google Patents

Description

1 2

The invention relates to lubricating greases which are used to reduce the amount of oleic acid (9-octadecenoic acid)

Lubrication of rolling bearings are suitable and a lubricant and other isomers of oleic acid, e.g. B. 12-octa-

Contain oil, which consists of a mixture of alkali decenoic acid and linoleic acid. The elaidic acid

or alkaline earth metal salts of a dicarboxylic acid, a fatty acid in the isomeric cis or syn form,

low molecular weight acid and a 5 while oleic acid has the trans or anti form

High molecular weight fatty acid is thickened. having.

There are known thickeners for lubricating grease, technical isooleic acid has about the following

those from a salt mixture of 99.5 to 75% C8-C22 characteristic values:

"Monocarboxylic acids and 0.5 to 25% sebacic acid titer *) ⁰ C 32

exist. Another thickener is made up of 10 TnHraiVi narh'w'iYs 7Ω

from a salt mixture with 20 to 80% C ₆ -Qo- '£ ^0Ü . ^zail i "f. Kj ' OV" nw "s» ~ \ οι

Monocarboxylic acid and 8 to 20% of a dicarboxylic acid (olemic acid) ^ l

acid with 4 to 6 atoms. _v . _f "'' ^ i ** {100

The lubricating greases according to the invention distinguish between verseiungszani; in the

differ from the previously known and related i ₅ ^{tarm nacn} ^ ^{araner ö}

High-temperature alkaline _{greases because the acid is less likely to cause the acid to dissolve} .

You also eat alkali and / or alkaline earth salts like an acid with a lower titer,

a monocarboxylic acid with 2 to 4 carbon- **) Contains inner esters that are easily split by saponification

contain atoms, where the equivalent ratios are

the Co-O-monocarboxylic acid to the dicarboxylic acid 20

2 to 10: 1, preferably 3 to 6: 1, and the equiva- The dicarboxylic valence ratios of the Cy-Qjo-monocarboxylic acid to the acids that can be used according to the invention include aliphatic acids with 9 to 16, dicarboxylic acids 1 to 4: 1, preferably 1 to 3: 1, preferably 10 to 12 carbon atoms, which are. can be straight or branched chain. In the case of a dicarboxylic acid, an alias for such acids are preferably azelaic acid, sebacic Cg-Cie dicarboxylic acid or an aromatic acid and dodecanedicarboxylic acid. Higher aliphatic dicarboxylic acid with 3 to 4 benzene nuclei, vertical dicarboxylic acids, ζ. B. uses so-called Kochsche, which seem to be substituted for lubricant atoms with up to 6 alkyl radicals with 1 to 8 carbon atoms. To carry greases which, in contrast to the known lubricating greases 30, have shorter lubrication times at higher temperatures, and the lubricating greases according to the invention are therefore not preferred within the scope of the invention. Apart from high temperatures as a result of phase changes in the aliphatic Cio-Cio-dicarboxylic acids mentioned, the soap thickener is neither excessively liquid nor can certain polynuclear aromatic dicarbons be excessively rubbery or fibrous. acids are used. These polynuclear acids The mixed salt thickeners according to the invention 35 can be represented by the following formulas: are best prepared so that they each have an alkali salt of 2 to 10, preferably 3 to 6 molar H COOH hydrogen equivalents of a low molecular weight C-> to Ci fatty acid molar hydrogen equivalent // \\

contain a dicarboxylic acid. In addition, 40 contain R ₀ ί— TT —H — R _h

this thickener a salt of 1 to 4, preferably \ // \

1 to 3 molar hydrogen equivalents of a highly

molecular C12 to C24 fatty acids per molar water H COOH

hydrogen equivalent of the dicarboxylic acid. To this ,

Thus, greases with a total content of 45 ^u

on these salts from 5.0 to 49.0, preferably 20 H COOH

up to 45 percent by weight based on weight

of the grease. This lubricating ^ / \

Fats can be converted into liquid or semi-R ₀ —f— | TT —fi— R ,,

liquid lubricants are diluted, which is about 50 / ^

Contains 0.1 to 5.0% mixed salt. .

Suitable low molecular weight acids for the production of H COOH

are the mixed salt thickener according to the invention

Acetic acid and propionic acid. Acetic acid and you in which the radicals R are alkyl groups with 1 to

Anhydride are preferred. 55 mean 8 carbon atoms, α and b values of

To the high molecular weight fatty acids or ali- 0 to 4 and the sum of α and b usually

Phatic carboxylic acids for the preparation of the mixed borrowed is no greater than about 6. One special

Salt thickeners according to the invention include the preferred polynuclear aromatic dicarboxylic acid

Naturally occurring or synthetic, substituted arises in petroleum refining and can through

or unsubstituted, saturated or unsaturated, 6 ° treatment of the aromatic-rich extract, the

mixed or unmixed fatty acids with about the extraction of catalytically cleaved

12 to 24. e.g. B. 16 to 24 carbon atoms is obtained in the cycle oil, with carbon dioxide and

Molecule. Examples of such acids are myristic sodium, being a salt of the

acid, palmitic acid, stearic acid, 12 - hydroxy aromatic carboxylic acid, which

Stearic acid, arachidic acid, oleic acid, ricinol-65 then by hydrolysis with a strong acid in

acid, hydrogenated fish oleic acids, tallow fatty acids, etc. the free dicarboxylic acid is converted. the

So-called technical iso-precise nature of the dicarboxylic acid thus obtained is particularly suitable

Oleic acid, composed mainly of elaidic acid with not known with certainty; the analysis shows

however, that they are mainly composed of the two alkyl-substituted dicarboxylic acids shown above 3 and 4 aromatic rings is composed.

The metal component of the mixed salt thickener is an alkali and / or alkaline earth metal, preferably Sodium and / or lithium.

The lubricating oil used to make the lubricants of the present invention can be a mineral lubricating oil or a synthetic lubricating oil, e.g. B. esters of dicarboxylic acids, glycol esters, halo ίο gene hydrocarbon oils or mixtures thereof. If the salts in the oil are made by itself, So it is best to use a mineral oil for this implementation, as there are many synthetic oils in the Salt formation will suffer from decomposition or hydrolysis. But once the salts have formed, so they can also be used for thickening lubricants similar to those mentioned above contain synthetic oils.

The lubricating grease according to the invention can also contain further additives. This is how you win at Addition of alkali phosphates, especially trisodium orthophosphate, to the lubricating grease not only one harder fat, but the trisodium phosphate also has an anti-oxidation effect and gives it the grease a longer lubrication time. Trisodium phosphate is commonly used in large quantities from 0.1 to 6.0, preferably from 1.0 to 5.0 percent by weight. The trisodium phosphate is preferred in as finely divided form as possible, e.g. B. added in a grain size of 15 μ or less. The trisodium phosphate can also be added to the oil itself by neutralizing orthophosphoric acid Generate with sodium hydroxide or crystallize from aqueous solution in the presence of oil, which is a protective stabilizing agent, e.g. B. an imidazoline salt contains.

The imidazoline can be mixed with various acids, such as ortho-, pyro- and metaphosphoric acid, Hydrochloric acid, sulfuric acid, nitric acid and also phytic acid.

When a stabilizer is used for the alkali metal phosphate, its amount is usually about 5 to 40, e.g. B. 10 to 30 percent by weight, based on the weight of the alkali phosphate.

Various other additives can be added to the lubricants (e.g. in amounts from 0.1 to 10.0 percent by weight) be added, such as detergents, e.g. B. calcium petroleum sulfonate, antioxidants, e.g. B. Phenyl-a-naphthylamine, corrosion inhibitors, e.g. B. sorbitol monooleate, dyes or other lubricating compressors.

The lubricants according to the invention can be prepared by neutralizing all of the carboxylic acids in at least a portion of the oil with the alkali base. The mixture is then heated to approximately 150 to 288 ^° C., preferably 204 to 260 ^° C., for the purpose of removing water. The higher temperatures of 204 to 260 ° C lead to the formation of a salt with a stronger thickening effect, better load-bearing capacity and better high-pressure properties than the lower dehydration temperatures.

example 1

58.5 parts of mineral lubricating oil with a viscosity of 55 SUS at 98.9 ° C., 15 parts of technical isooleic acid (fatty acid) and 4 parts of sebacic acid are intimately mixed with one another in a directly heated fat kettle. Then, 10 parts of glacial acetic acid and immediately thereafter 11.5 parts of 100 ° / ₀ sodium sodium hydroxide in the form of an aqueous solution of 40 weight percent sodium hydroxide and 60 weight percent water is added. Heating begins and the temperature of the reaction mixture is increased in the course of 2 hours to 218 ° C., whereupon this temperature is maintained for V4 hours. The fat is then ^{cooled to 121 °} C. while mixing, and 1 part of phenyl-a-naphthylamine is added as an oxidation retarder. The fat is then further ^{cooled to 49 °} C. and homogenized in a Gaulin homogenizing device to form a uniform, smooth structure.

Example 2

A lubricating grease is prepared according to the procedure of Example 1, but with 4 parts 1,12-dodecanedicarboxylic acid instead of sebacic acid.

Comparison grease A

This fat is prepared according to Example 1, but with 4 parts of azelaic acid instead of Sebacic acid.

The fats of Examples 1 and 2 and Comparative Grease A are subjected to a number of standard tests and subjected to a temperature rise test in a ball bearing. With the latter Test is using a 204mm steel ball bearing 3.0 g of the fat to be examined and then filled with a rotation speed of 10,000 rev / Min. Run, with the temperature of the grease in the bearing continuously through Thermocouples are measured, which are located in the outermost race of the bearing.

The compositions of the above greases and their physical properties are in Table I summarized.

Table I. at
1 .game 2 10.0
15.0
4.0 Grease A 10.0
15.0
4.0 10.0
15.0 Composition, percent by weight
Glacial acetic acid Isooleic acid 4.0 Sebacic acid Dodecanedicarboxylic acid Azelaic acid

continuation

Grease A

Sodium hydroxide

Phenyl-a-naphthylamine

Mineral lubricating oil; 55 SUS at 98.9 ° C

properties

Appearance

Drop point, ⁰ C

ASTM penetration at 25 ° C, mm / 10

Resting penetration,

Walk penetration after 60 thrusts

Walk penetration after 10,000 hits

Rest penetration after treatment in the roller mixer

Beaker test at 232 ° C *)

Lubrication duration **) at 10,000 rpm.

at 121 ° C

at 149 ° C

at 177 ° C \

Temperature rise in the ball bearing begins at room temperature, ^C C

after 15 minutes of running time

after 1 hour running time

after 24 hours of running time

11.5
1.0

58.5

11.5 1.0

58.5

excellent smooth fat> 260

> 260

11.5 1.0

58.5

granular> 260

290 290 290

310 310 310

300 300 300

198 198 198

no phase change, little softening

> 2000

> 2000

500

27
60
32
29.5

> 2000

> 2000

450

27 57
35
29.5

not investigated further due to poor appearance

*) The grease is slowly heated to 232 ° C with slow stirring, with any changes in the consistency of the grease

to be observed.
**) ABEC-NLGI spindle test.

The table above shows the superiority of the greases according to Examples 1 and 2 compared to the comparison fat A.

Another comparison grease, which is produced according to Example 1, but using 4.0 percent by weight of a branched-chain so-called Koch's acid with 19 carbon atoms, gives a lubrication time of only 426 hours at 121 ^C C, which corresponds to a lubrication time of over 2000 hours for the Compare greases according to Examples 1 and 2. This results in the poor performance of greases made with too high molecular weight dicarboxylic acids.

Between the lubricating greases according to the invention and two closely related ones, commercially available for For the lubrication of mixed salt lubricating greases available from ball bearings, a number of comparative tests have been carried out. The comparative products are designated as lubricating grease B and C, respectively.

The lubricating grease B consists of mineral lubricating oil, which is thickened with a sodium mixed salt thickener, which is produced by neutralizing a mixture of stearic acid and acetic acid with sodium hydroxide solution, whereupon the mass is ^{heated to 210 °} C. until dehydration and a satisfactory dispersion of the soap is achieved . Then, the fat is cooled, added with a Oxydatipnsverzögerer, further cooled to 43 ⁰ C, milled and packaged.

The lubricating grease C is produced by alkali melting of rapeseed oil. This is rapeseed oil heated in mineral oil with sodium hydroxide until the evolution of hydrogen, whereby due to alkali melt Form mixed sodium salts of high and low molecular weight carboxylic acids.

Greases B and C are both premium ball bearing greases, and the latter takes on this one Areas have been in a leading position for about 20 years.

The lubrication time of the grease according to Example 1 and the greases B and C in the ABEC-NLGI spindle test in a rotating at different temperatures with 10,000 rpm 204 mm rolling ball bearings are summarized in Table II.

Table II
Lubrication duration according to ABEC-NLGI spindle test

Grease

Grease B

Grease C

Grease according to
example 1

Lubrication time, hours 121 ° C 149 ° C 177 ^C C

1800 2000

2000

350 300

2000

50 50

500

Electric motors and other modern devices operating at high temperatures can be over considerably if the new lubricant is used with sufficient lubrication

longer periods of time and operated at higher temperatures than before.

A pressure-viscosity test was also carried out with the lubricating greases according to Examples 1 and 2 and the above-described known lubricating grease C. Here, the grease was at a rate of 3 cm ³ / min. pressed through a 0.05 mm wide capillary at different temperatures, the ^{pressure required to maintain the flow rate of 3 cm 3} / min. being measured ^{in kg / cm 2.} The results of these tests are shown in the figure, according to which the apparent viscosity of the lubricating greases according to Examples 1 and 2 increases continuously and over a long period with increasing temperatures.

sam, while the well-known grease (grease C) at temperatures below 15O ⁰ C first undergoes a thickening or viscosity increase and only starts to decrease in its viscosity.

The following example shows the superiority of the new grease over one without the addition of a lower fatty acid. It was a lubricating grease according to Example 1 and as a comparison a lubricant with no acetic acid content, instead with a correspondingly larger amount of isooleic acid and sebacic acid, prepared from the proportions listed below in otherwise the same manner. The proportions are given in the list below as percentages by weight.

Components

Lubricant according to the invention according to Example 1

Comparative lubricant

Glacial acetic acid

Isooleic acid

Sebacic acid

Sodium hydroxide (40%)

Phenyl-M-naphthylamine

Mineral lubricating oil, 55 SUS at 98.9 ° C

The lubricants showed the following properties:

10.0
15.0

4.0
11.5

1.0
58.5

10

22.9 6.1 6.5 1.0

63.5

properties Lubricant according to the invention
medium according to example 1 Comparative lubricant Appearance excellent smooth fat
260
290
310
300
198
no phase change,
slight softening
27
60
32
29.5 bad and grainy
182
205
210
315
300
becomes fibrous at 171 ^{G C.}
becomes tough at 193 ° C
27
60
79.5
79.5 Dropping point. C.
ASTM penetration at 25 ° C, mm / 10
Resting penetration
Walk penetration after 60 thrusts
Walk penetration after 10,000 hits
Rest penetration after treatment in the roller mixer
Beaker test at 232 C *)
Temperature rise in the ball bearing
Start at room temperature, C
after 15 minutes of running time
after 1 hour running time
after 24 hours of running time

*) The grease is slowly heated to 232 "C with slow stirring, with any changes in the consistency of the grease to be observed.

The lubricating greases according to the invention can be further enhanced by adding finely divided phosphate to enhance.

Example 3 Part A

10 parts of the above-described l- (2-aminoethyl-2-alkenyl-2-imidazoline) and 17.8 parts of mineral smear / oil are mixed together and with 2.2 parts of 100% phytic acid in the form of a 70% aqueous solution are added. This forms the phytate of the imidazoline derivative, which thickens the oil to a fat consistency. Then will 70 parts of hydrated trisodium orthophosphate (NagPO4 · I2H2O) in the form of a 40 weight percent added aqueous solution. The whole mixture is heated to a boil, up to about 50 percent by weight of the free water have evaporated. After cooling, the mass forms a very stable gel a total water content of 50 percent by weight, based on the total weight of the gel.

part B

A lubricating grease is made as follows: 59.5 parts of mineral lubricating oil with a viscosity

909 525/430

of 55 SUS at 98.9 ° C, 15 parts of technical isooleic acid (as in Examples 1 and 2) and 4 parts of an aliphatically substituted aromatic dicarboxylic acid obtained from the extract of a catalytic cycle oil are intimately mixed with one another in a directly heated fat kettle. 10 parts of glacial acetic acid are added to the mixture, followed immediately by 10.5 parts of sodium hydroxide in the form of an aqueous solution of 40 percent by weight sodium hydroxide and 60 percent by weight water paused for 15 minutes. then the fat is cooled to 121 ⁰ C, with 1 part of phenyl-a-naphthylamine as oxidation retarders are added and further cooled to 38 ° C. a portion of the fat and then removed from the boiler of a Gaulin homogenizer homogenized at 105 kg / cm ^2.

Part C.

20th

The remainder of the lubricating grease remaining in the kettle is ^{heated again to 204 °} C. and mixed with 4 parts of a colloidal dispersion of sodium phosphate in mineral oil stabilized with the aid of the reaction product of imidazoline and phytic acid (product according to Part A). The fat is then cooled to 38 ° C. with stirring and homogenized in a Gaulin homogenizer at 105 kg / cm ² .

The alkyl-substituted aromatic dicarboxylic acid used here is a mixture of acids with molecular weights of about 450 to 550. Their saponification number is 200 mg KOH / g. The acid is obtained from an aromatic extract by treatment with sodium, then with carbon dioxide and subsequent hydrolysis. The extract was obtained by extracting a catalytic cycle oil. This oil consists of 17 percent by weight of 3-ring aromatics, 63 percent by weight of 4-ring aromatics and the remainder mainly of naphthenes with small amounts of thiophenes, paraffins etc. The acid is produced from this oil as follows: ¹ Iz molar equivalent of the catalytic cycle oil extract is converted into 350 ml of tetrahydrofuran dissolved and the solution was added dropwise with stirring to a mixture of 1 g atom of sodium chips in 150 ml of tetrahydrofuran. In this 3 hour-long addition, the reaction mixture turns reddish and then black, and the temperature rises from 26 to 36 ° C. After completion of the addition, the reaction mixture is heated to reflux temperature (68 ⁰ C) and stirred for a further 3.75 hours at reflux temperature. Almost all of the sodium has reacted, from which it can be concluded that the disodium addition product of the reactive polynuclear aromatic hydrocarbons was formed. The disodium addition product is then poured onto several kilograms of powdered solid carbon dioxide in an inert atmosphere, the slurry stirred several times and the mixture allowed to stand until the excess carbon dioxide has evaporated. After the mixture has reached room temperature, 25 ml of methanol are added with stirring in order to destroy the excess sodium. Then 2000 ml of water are added and the mixture is allowed to stand. The organic layer (which contains the non-reactive components of the aromatic extract) is separated from the aqueous layer and the aqueous layer is washed several times in succession with pentane. Dilute hydrochloric acid (90 ml of concentrated hydrochloric acid in 250 ml of water) is then added to the aqueous layer. The acidified mixture is extracted several times with diethyl ether in order to remove the carboxylic acid. Evaporation of the ether gives a syrupy mixture of polynuclear aromatic carboxylic acids.

Examples 4 to 6

A number of lubricating greases are made as follows: Mineral lubricating oil, isooleic acid and sebacic acid are mixed together in a fat kettle. Glacial acetic acid is then added, followed immediately by sodium hydroxide in the form of an aqueous solution of 40 percent by weight sodium hydroxide. The whole is heated to 150 ⁰ C, then treated with trisodium phosphate in the form of an aqueous solution containing 50 weight percent NaaPO-i · 12 H-> 0 contains, and further heated to 232 ° C to dehydrate the grease. The mass is cooled to 121 ° C. while stirring and phenyla-naphthylamine is added as an oxidation retarder. The product is then allowed to cool to 38 ° C. and homogenized in a Gaulin homogenizer at 105 kg / cm ² .

The lubrication time at 149 ° C and at 177 ° C is considerable due to the addition of trisodium phosphate elevated. The lubricating grease according to Example 4 also shows a longer lubricating time at 149 ° C. during the greases according to Examples 5 and 6 show that by increasing the amount of trisodium phosphate even longer lubrication times can be achieved at high temperatures.

Table III

3-C example 5 6th 3-B-- 9.6 4th 10.0 10.0 10.0 14.4 6.82 15.0 15.0 15.0 " 3.8 10.23 - - 4.0 - - 4.0 4.0 - 10.0 2.73 11.5 11.5 10.5 4.0 **) 7.84 3.0 4.0 - 1.0 2.73 1.0 1.0 1.0 0.68

Composition, percent by weight

Glacial acetic acid

Isooleic acid

Alkyl substituted aromatic dicarboxylic acids

Sebacic acid

Sodium hydroxide

Sodium phosphate

Phenyl-rt-naphthylamine

**) Colloidal dispersion.

continuation

3-B

3-C

example

4 5

mineral oil

Molecular equivalent ratio of acetic acid to dicarboxylic

acid

Molecular equivalent ratio to isooleic acid

Dicarboxylic acid

properties
Appearance

Drop point, ⁰ C

ASTM penetration at 25 "C, mm / 10

Resting penetration

Walk penetration after 60 thrusts

Walk penetration after 10,000 hits

Lubrication duration *) at 10,000 rpm, hours

at 121 ° C

at 149 ° C

at 177 ° C

*) ABEC-NLGI spindle test.

59.5
: 1
3.3: 1

57.2
10: 1
3.3: 1

excellent
smooth fat

260

204
250

282

> 2000

728
275

260

250

282
292

> 2000

> 2000

344

68.97
4.2: 1
1.2: 1

246

248
255
312

1300

55.5

4.2: 1

1.3: 1

excellent
260

201
216

272

> 2000

> 2000

445

54.5

4.2: 1

1.3: 1

260

212
252
282

> 2000

> 2000

435

Example 7

Example 3, parts A and B, are used, but with 4 parts of an alkyl-substituted aromatic Dicarboxylic acid of the structural formula

COOH

H COOH

instead of the aromatic acid described in Example 3 and using such Amount of sodium hydroxide that a neutral product is formed.

While the above is primarily devoted to greases that are used for Suitable bearing lubrication, the invention also includes greases for use in other ways Lubrication purposes.

According to a further embodiment of the invention, when using lithium and A predominantly saturated high molecular acid lubricating grease obtained in both cold Are insoluble in water as well as in boiling water. In view of this water insolubility you can the greases are used on ships or for other purposes where the bearings or the fat itself is exposed to high levels of moisture or water vapor. This insolubility in water but requires the addition of rust inhibitors for ferrous metals for most purposes.

In the manufacture of lithium greases, there are certain molar ratios of the various acid components to prefer. In this case, azelaic acid can also be used as the dicarboxylic acid as well as a certain amount of calcium salt. The use of azelaic acid allows a more economical one due to its low cost compared to the other suitable dicarboxylic acids Manufacture of lubricating greases. The use of calcium in place of part of the Lithium enables further savings in fat production, since the calcium base is inexpensive. Furthermore, when using calcium, it is possible to use larger amounts of unsaturated fatty acids to be used without destroying the water-insolubility of the grease. One only lithium as Grease containing metal and unsaturated fatty acids only is water soluble, especially in hot one Water. A lubricating grease containing only calcium has when using the acids and the relative Amount ratios of the acids, as used in the context of the invention, without their presence poor structural stability from water or other stabilizers. The presence however, water is undesirable as it allows the effective use of the grease at high temperatures as a result of water loss at such high temperatures prevented while through the addition of stabilizers increases the cost of the lubricant and possibly its Properties are changed in an undesirable manner.

The mixed salt thickeners according to this embodiment of the invention contain most advantageously the metal salt from 0.5 to 3.0, preferably from 1 to 2 molar hydrogen equivalents of a low molecular weight C2 to Q fatty acids per molar hydrogen equivalent of a dicarboxylic acid. Also included these thickeners preferably contain the metal salt of 0.5 to 3.0, preferably 1 to 2 molar hydrogen equivalents a high molecular weight fatty acid with 12 to 24 carbon atoms per molar water

equivalent of the dicarboxylic acid. In this way, lubricating greases with a total content are obtained such metal salts from 5.0 to 49.0 percent by weight, preferably from 15 to 35 percent by weight, based on the total weight of the grease. This grease can in turn can be diluted with further oil to form liquid or semi-liquid lubricants that make up the mixed salt contained in concentrations of about 0.1 to 5.0 percent by weight.

Only lithium or a mixture of lithium and calcium in a ratio can be used as the metal from 1 to 4: 1 parts by weight can be used.

Example 8

68.3 parts of mineral lubricating oil having a viscosity of 60 SUS at 98.9 ° C, 15 parts of hydrogenated fish oil acids and higher fatty acid and 3 parts of azelaic acid are mixed together in a directly heated fat vessel under stirring at 52 ⁰ C. Then 3 parts of glacial acetic acid and then 5.7 parts of lithium hydroxide monohydrate in the form of an aqueous solution containing 10 percent by weight of lithium hydroxide monohydrate are added. The contents of the kettle are ^{heated to 218 C} C with stirring in order to dehydrate the mass. The temperature of 218 ° C. is maintained for 15 minutes, after which the heating is switched off and the boiler is cooled by passing water through the boiler jacket. The contents of the kettle have cooled to 120 ° C. in 60 minutes while stirring continuously. Then 1 part of phenyl-a-naphthylamine is added as an oxidation retarder, the temperature is continued to 49 ° C and 2 parts of finely divided sodium nitrite (about 1.0 to 35 μ) are then added as a mixture of equal parts by weight of sodium nitrite and mineral lubricating oil with a viscosity of 50 SUS at 98.9 ⁰ C added. After the sodium nitrite has been added, the product is homogenized in a Morehouse mill to form a finished grease.

The hydrogenated fish oil acids are a technical product with an average chain length of 18 carbon atoms and a similar content of unsaturated bonds, such as technical stearic acid, with an iodine number according to Wij s of a maximum of 3. They are obtained by hydrogenating the fish oleic acids of the Menhadenfish won.

Example 9

A lubricating grease is prepared according to Example 8, but with the higher fatty acid from a mixture from a) hydrogenated fish oleic acids and b) tallow fatty acids with a saponification number of 203 and an iodine number according to Wijs of 55. There will also be slightly different amounts of Mineral oil and lithium hydroxide are used.

Example 10

A grease is prepared according to the method of Example 8, except that part of the Lithium hydroxide monohydrates is replaced by hydrated lime and the reactants in something different amounts can be applied.

The following table shows the compositions of the lubricating greases according to Examples 8 to 10 and its main properties in comparison with one made from lithium hydroxystearate Premium ball bearing grease of a known type compiled.

The beaker test at 204 ^° C. is carried out by slowly heating the lubricating grease in a beaker with stirring in order to determine whether a change in structure is taking place.

The wheel bearing test is carried out in accordance with ASTM test standard D-1263-53 T with the difference that that the test is carried out in the present case at an angle of 45 ° to a possible Expedite speed up.

The temperature rise test in the ball bearing is carried out as follows: A 204 mm steel ball bearing is filled with 3.0 g of the lubricating grease to be tested and then at 10,000 rpm, circulated, with the temperature of the grease in the bearing constantly with the help of Thermocouples located in the outermost race of the bearing.

The CRC-L-41 test is performed by chemically pure Timken bearings (lids and bearings) coated with a thin layer of grease and then under such a load at 1600 rpm. be allowed to circulate so that the grease spreads in a thin layer. Then that will Unit consisting of lid and bearing immersed in water and in a closed glass container for 14 days with a small amount of water to create a humid atmosphere. After 14 days, the bearing is checked for rust.

Table IV

example - 1.0 10 3.0 Lithium hydroxy 8th 9 2.0 3.0 4.1 stearate grease 3.0 3.0 67.9 15.0 2.0 15.0 10.0 - 1.0 11.0 5.0 2.0 - 3.0 3.0 67.9 - 5.7 1.0 1.8 - 1.0 1.0 2.0 2.0 68.3 82.2

Composition, percent by weight

Glacial acetic acid

Hydrogenated fish oleic acids

Tallow fatty acids

Azelaic acid

Lithium hydroxide monohydrate

Hydrated lime

Phenyl-a-naphthylamine

NaNO ₂

Mineral lubricating oil, 60 SUS at 98.9 C

continuation

example 9

Lithium hydroxystearate grease

Mineral lubricating oil, 50 SUS at 98.9 ⁰ C

Molar hydrogen equivalent ratio

Acetic acid to azelaic acid

Molar hydrogen equivalent ratio

higher fatty acid to azelaic acid

properties

Appearance

Drop point, ⁰ C

ASTM penetration at 25 ° C, mm / 10

Resting penetration

Walk penetration after 60 thrusts

Walk penetration after 10,000 hits

Beaker test at 204 ⁰ C

Solubility in boiling water

Oxidation test according to Norma Hoffman,
Hours until the pressure drops by 0.35 kg / cm ² ...

Accelerated wheel bearing test at 104 ⁰ C, 1 hour,

45 ° angle

Slump

Run out, g

Lubrication duration *) at 10,000 rpm, hours

at 121 ° C

at 149 ° C

Temperature rise in the ball bearing at

10,000 rpm, ⁰ ° C

Initial temperature rise

Steady state at ⁰ C

Rust test CRC L-41

*) ABEC-NLGI spindle test.
**) Examination canceled after 2000 hours.

Example 8 illustrates a lubricating grease according to the invention containing only lithium 40 as the metal base,
which is made from a saturated technical fatty acid
is made. Example 9 shows that greases are good
using a predominantly (i.e. to more
than 50%) saturated high molecular weight fatty acid 50 can be produced. Example 10 explained
the replacement of part of the lithium by calcium.

2.0

1.57

1.66

> 232

205
210

225

2.0

1.57

1.66

excellent
> 232

220
225
230

2.0

1.57

1.66

> 232

240
245
285

2.0

no phase change except
low softening

insoluble

0.6

> 2000
400

5.5
27

enough
none
0.2

> 2000
625

8.3
27
enough

1.0

> 2000
740

8.3 27

excellent 180

260 265 280

Phase change at 163 ^° C., melts at

Insoluble at 177 ° C

25th

enough

none

5.0

1120 120

36 80 is sufficient

Example 11

The procedure is as in Example 8, but using 3 parts of an alkyl-substituted aromatic Dicarboxylic acid of the structural formula

COOH

instead of the azelaic acid of Example 8 and with such an amount of lithium hydroxide monohydrate, that a neutral product is created.

Claims (2)

Patent claims: 1. Lubricating grease, consisting of a lubricating oil and a thickener of alkali and / or alkaline earth salts of a C? - to C3o-monocarboxylic acid and a dicarboxylic acid, characterized in that it also has alkali and / or alkaline earth salts of a monocarboxylic acid with 2 to Contains 4 carbon atoms, the equivalent ratios of the C2 to Q monocarboxylic acid to the dicarboxylic acid being 2 to 10: 1 and the equivalent ratios of the Ct to Cso monocarboxylic acid to the dicarboxylic acid being 1 to 4: 1. 2. Lubricating grease according to claim 1, characterized in that that it is an aliphatic Cg to Cie dicarboxylic acid or a dicarboxylic acid aromatic dicarboxylic acid with 3 to 4 benzene nuclei, which have up to 6 alkyl radicals with 1 to 8 carbon atoms can be substituted contains. 909 525/430