DE1120624B - Lubricating greases - Google Patents

Description

The invention relates to lubricating greases.

It is known that lubricating oils can be thickened to the consistency of lubricating grease by means of thickeners can. Known thickeners are, for example, fatty acid soaps and soaps made from oxy-fatty acids. These oxyfatty acid soaps are distinguished by the fact that they are attached to the hydrocarbon radical of the carboxylic acid carry free hydroxyl groups.

In contrast, the invention relates to a lubricating grease based on a fatty acid soap and / or oxy fatty acid thickened lubricating oil, which is characterized in that it Contains at least one fatty acid soap substituted by at least one metal oxy group in the acid residue is. The lubricating oil is preferably a mineral oil.

The metal oxyfatty acid soaps used according to the invention are therefore fatty acid soaps in which at least 1 carbon atom of a hydrocarbon chain of soap (R) is bonded to 1 oxygen atom, which in turn is bound to a metal again. Metals which form alcoholates are preferably used here can, in particular lithium, sodium, barium or aluminum. In the case of a polyvalent metal this can be bound to more than one hydrocarbon residue in a soap via oxygen atoms. the Hydrocarbon radicals can have one or more other substituent groups, e.g. B. a hydroxyl group, contain.

Fatty acid soaps of the formula

used, in which R is an optionally substituted metal oxyhydrocarbon radical, Me a soap-forming metal or a corresponding group, in particular an alkali, alkaline earth metal, magnesium or aluminum, χ the valence of Me and η zero or a number less than χ .

The fat consistency can be achieved by using a mixture of different metal oxy-fatty acid soaps or a mixture of metal oxy soap and other soaps, e.g. B. Hydroxy fatty acid soaps, be achieved.

The thickening agent can expediently by reaction of a hydroxy fatty acid or a soap of the same with a metal or metal alcoholate. A particularly suitable one Hydroxy acid is 12-hydroxystearic acid. The on this Products obtained in this way can be used directly for the production of fats according to known methods be e.g. B. by heating a mixture of the oil and thickener to a temperature when the complete solution takes place (usually applicant:

The British Petroleum Company Limited, London

Representative: Dr.-Ing. A. v. Kreisler, patent attorney,
Cologne 1, Deichmannhaus

Claimed priority:
Great Britain, March 5, 1958 (No. 7069)

Samuel Richard Pethrick and Aleksander Groszek, Sunbury-on-Thames, Middlesex (Great Britain),

have been named as inventors

about 200 ⁰ C) and subsequent rapid cooling to room temperature.

Another way to prepare the thickener is to use an ester of a Reacting hydroxy fatty acid with a metal or metal alcoholate to form a metal oxy fatty acid ester and the latter with a metal hydroxide e.g. B. in part or all of the amount of the too hydrolyze thickening oil. The fat is then formed in a known manner. A special one a suitable ester is hydrogenated castor oil, which consists essentially of glyceryl tri-12-hydroxystearate consists. The use of esters, e.g. B. of hydrogenated castor oil, represents the simplest and cheapest Method for the production of fats according to the invention, but the use of fatty acids or fatty acid soaps as the starting material has the advantage that the fats formed do not contain glycerine, which is present in the fats made from hydrogenated castor oils.

The amount of soap present in the fat masses according to the invention is preferably 5 to 30 percent by weight, in particular 8 to 15 percent by weight, based on the total mixture.

A number of thickeners have been used for example produced as follows, but the production of metal oxy soaps within the scope of the present Description should not be placed under protection:

109 757/541

The thickeners S1, S2, S3 and S4 (see table 1) were made from glyceryl tri-12-hydroxystearate (in the form of hydrogenated castor oil). The hydrogenated castor oil was in a stirrer and Thermometer-equipped flask and melted. The calculated amount of lithium by weight or sodium was then added and the temperature increased until the reaction started (about 190 ° C). The temperature was then maintained between 200 and 250 ° C. until the reaction was complete.

The thickener S 5 was prepared as follows: Lithium ethoxide was added to molten hydrogenated castor oil. The mixture was ^{heated to 200 °} C. with stirring and the alcohol formed during the reaction was distilled off. The alcohol which remained in solution in the oil after the reaction had ended was removed by applying a vacuum.

The thickener S 6 was made from 12-hydroxystearic acid and lithium. The reaction was carried out under nitrogen. Small amounts of finely divided lithium of the molten acid was added, which was kept at a temperature of 22O ⁰ C. The mixture was stirred vigorously throughout the time of addition until each

ίο part was fully implemented. After adding the Last portion of lithium, the reaction was brought to completion by allowing the mixture 1.5 hours heated to 250 to 260 ° C.

The reactants used, the reaction temperature and information about the individual Products are listed in Table 1.

React
metal on participant
Hydroxy acid
or
Ester React
functional
tempe-
rature
⁰ C Table 1 Appearance of the product Remarks Ver
dik-
k-
middle lithium
1.88 g 400 g
hydrogenated
castor oil 230 Solidification
rungs
Point
of
Product
° C Greenish brown,
opaque
soft fat Reaction in 3 bis
Finished 4 hours Sl lithium
6.7 g 400 g
hydrogenated
castor oil 230 115 Light brown, impenetrable
more sighted, softer
amorphous solid Reaction after 6 hours
digem heating
incomplete S2 lithium
3.6 g 400 g
hydrogenated
castor oil 220 170 Light brown, impenetrable
more sighted, softer
Solid Reaction in 6 bis
Finished 8 hours S3 sodium
0.8 g 400 g
hydrogenated
castor oil 210 160 Light brown, impenetrable
more eye-catching waxy
Solid Reaction in 3 bis
4 hours completed S4 lithium
ethoxide
11.5 g 400 g
hydrogenated
castor oil 200 150 Straw colored, moderate
soft, waxy,
sticky Reaction in 3 bis
4 hours completely S5 lithium
2.8 g 150 g
12-hydroxy
stearic acid 220 140 hard, brittle, through
shining, light brown Reaction begins at 180 ⁰ C
a. Most of the
Lithium reacts to
220 ° C. Last lithium
traces are through
Heat to 250 bis
260 ° C away S6 190

The reaction products were then used to produce fats Gl to G 6 (see Table 2). This was done as follows:

Gl, G2 and G4. A mixture of 200 g of acid-treated mineral lubricating oils, their viscosity was measured in the Redwood viscometer # 1 at 60 ° C, 140 and 50 seconds, was heated to 75 ³ C. Then 400 g of the thickener and then 46.2 g of lithium hydroxide monohydrate, dissolved in 400 cm ^{3 of} water at 65 ° C., were added. After slowly heating the mixture to 120.degree. C., 800 g of the same oil mixture were added and the temperature increased to 137.degree. A mixture of 140 parts of an oil 160/95 (viscosity 160 seconds in Redwood viscometer No. 1 at 60 ° C., viscosity index 95) and 560 parts of a bright stock oil (620 seconds in Redwood viscometer No. 1 at 71 ° C.) was then used ° C, viscosity index 95) was added and heating continued until about 170 ° C were reached. The mixture was then cooled to 135 ° C, poured and passed through a roller mixer with a. Roll gap of 0.076 mm given. G3 and G5: The production was carried out in the same way as for Gl, G2 and G4, but the oil used had a viscosity of 150 Redwood seconds at 60 ° C.

G6: The thickener was dissolved with stirring in a lubricating oil having a viscosity of 150 Sekünden measured in the Redwood viscometer No. 1 at 6O ⁰ C.. The solution was quickly cooled to room temperature, kneaded and degassed as before.

A grease with lithium 12-hydroxystearate was used for comparison (G7) made as follows:

G7. A mixture of 200 g of acid-treated mineral lubricating oils, their viscosity, measured in the Redwood viscometer No. 1 at 6O ⁰ C, was 140 or 50 seconds, was heated to 75 ⁰ C. 400 g of hydrogenated castor oil and then 58 g of lithium hydroxide monohydrate, dissolved in 600 cm ^{3 of} water at 65 ^° C., were then added. Heating was continued and the temperature of the mixture was increased to 90 ^° C., whereupon a further 100 cm ^{3 of} water were added. After heating the mixture at 12O ⁰ C 800 of the same oil blend were added to g and the temperature was raised to 137 ⁰ C. Then a mixture of 140 parts of an oil was 160/95 (160 Redwood-l-seconds at 6O ⁰ C, viscosity index 95) and 560 parts of a bright stock oil (620 Redwood-l-seconds at 71 ⁰ C, viscosity index 95 ) and continued heating until a temperature of about 190 ⁰ C was reached. The mixture was then cooled to 135 ° C, poured and passed through a roller mixer with a roller gap of 0.076 mm.

The composition and properties of the fats are listed in Table 2. The one mentioned here

ίο Penetration (IP method 50/56) is a measure of that Consistency of a fat. The "bleeding test" (Ministry of Supply Specification DTD 825A) indicates the tendency to recognize the liquid phase (oil), to separate from the fat structure. The dropping point (IP method 31/57) indicates the temperature at which a fat becomes liquid.

Tabel

Components of fat oil
G LiOH-H ₂ O Properties of the Walkpe
60 shocks penetration
lOOOOO kicks 265 295 Fat Dropping point fat
No. Thickening
middle 2500 46.2 Penetration at 21 ^c C 217 262 276 Sweat test
(DTD 825) ⁰ C 40OgSl 2500 46.2 Unedited 163! 228 262 Oil loss
Weight percent 186 Eq 400 g of S-2 3240 33 215 214 252 i 332 0.8 191 G2 400 g S3 2500 46.2 171 225 246 0.2 185 G3 400 gS4 2500 46.2 195 219 0 187 G4 400 gS5 88 -. 220 1.9 188 G5 12gS6 2500 58 218 0.2 187 G6 400 g hy 200 1.1 190 G7 third - 2.4 castor oil

The values show that the fats according to the invention (Gl to G 6) have good dropping points and good consistency to have. They also have far more improved exudation resistance than that Grease made with lithium hydroxystearate (G 7). The fats Gl to G 6 also contain less soap than the fat G 7.

The fats Gl to G 6 all had a true texture. G 6 in particular was a very smooth fat.

The G 4 grease was subjected to a mechanical test at room temperature using a roller bearing which was 60 x 130 x 46 mm in size and rotated at 2500 rpm. The camp was radially loaded with 851 kg and the direction of rotation changed every 24 hours. The test duration was a total of 200 hours. The bearing was examined for wear on the grooves, rollers and cage and the Checked leakage of grease. No adverse phenomena were found.

The same mechanical test was carried out with G 6 grease, but for a time of 667 hours. The result was again very good.

60

Claims (5)

Patent claims: Acid radical is substituted by at least one metal oxy group. 2. Lubricating grease according to claim 1, characterized in that the soap is in the metal oxy group contains an alcoholate-forming metal, in particular lithium or sodium. 3. Lubricating grease according to Claims 1 and 2, characterized in that it is metal oxy-fatty acid soaps the general formula contains, in which R an optionally substituted metal oxyhydrocarbon radical, Me a soap-forming metal or a corresponding group, χ the valence of Me and η zero or a number less than χ . 4. Lubricating grease according to claim 3, characterized in that Me is an alkali or alkaline earth metal, Is magnesium or aluminum and preferably lithium. 5. Lubricating grease according to claim 1 to 4, characterized in that it is the metal oxy fatty acid soap in amounts of 5 to 30 percent by weight, preferably 8 to 15 percent by weight, based on the total mixture. 1. Lubricating grease based on soap. Documents considered: of fatty acids and / or oxy fatty acids German patents No. 842 108, 886 948, thickened lubricating oil, characterized in 65 947187, 947 188, 947 420, 947 728, 950 804, 961383; that it contains at least one fatty acid, which in German Auslegeschrift No. 1011 111, 1044 328. 109757/541 12.61