DE1810085B2 - Lubricating oil - Google Patents

Description

55

The present invention relates to lubricating oils, consisting of a mineral lubricating oil or a synthetic ester lubricating oil and a _b o ethylene-Z-propylene mixed polymer fraction, which have good properties in terms of viscosity, in particular viscosity index, pour point, stability to shear forces, oxidation, heat, etc. With these lubricating oils, multi-range lubricating oils of the classification SAE 10-W-50 can be achieved.

It is known that for the production of multigrade lubricating oils with a high viscosity index and three main methods were used at the low pour point:

The first is to increase the refining of the mineral oils, but in this case you can Oils with a high viscosity index can only be obtained if the viscosity remains low. It is therefore Although it is possible to achieve the SAE 5-W-20 classification, there is a restriction to the oils SAE 20-W-30, if a change to the SAE 30 classification is to be made.

The second method uses synthetic oils, but it is not in the prior art possible to achieve the classification 10-W-40 or 10-W-50 with the oils obtained from olefins and with oils of the ester type one remains restricted to the classification 5-W-20 and 10-W-20

Finally, one can still try to improve the viscosity index and the pour point of Use additives based on mineral oils or synthetic oils.

The additives previously used for this purpose are polymers or copolymers with a high Molecular weight. However, they fail under high shear stress, as is the case especially in gear drives or piston pumps occur in hydraulic systems, and are also against oxidation not stable enough. The technical development in these areas shows the tendency to always heavier mechanical loads. There are currently two types of additives available to improve the Viscosity index available. Once those of the polyisobutylene type, the shear strength of which is acceptable, because in the "sonic breakdown test" (investigation of the tearing off of the lubricating film by sonication) Provide viscosity gradients in the range of 24% for a 10% solution in a mineral oil. However they deteriorate due to oxidation. In addition, additives of the polymethacrylate type, fumarate etc. used. Although these are more stable to oxidation, they are not stable to shear, so that the waste in the Viscosity in the "sonic breakdown test" is in the range of 50%. In addition, the currently increasing known additives which improve the viscosity index, the viscosity of the oils at low temperatures very strong, so that there is a considerable discrepancy between the viscosity measured at -17.8 ° C and the viscosity extrapolated from the ASTM Viscosity Temperature Map. From the DT-AS 17 95 425 lubricants are also known that in addition to a base lubricating oil a smaller proportion of ethylene / propylene copolymer as an additive for improvement the viscosity index properties of the lubricant, the copolymer being a Has a molecular weight of 10,000 to 40,000. A disadvantage of these copolymers is that they Are solids and are therefore difficult to dissolve in the base lubricating oil. Another disadvantage of this Copolymers containing lubricants is their unsatisfactory shear stability, which is reflected in a percentage loss of viscosity at 99 ° C. of up to 2.6, as shown in Examples 3 to 6 can be found in this publication.

The present invention was based on the object of providing a lubricating oil based on a mineral lubricating oil or to create a synthetic ester lubricating oil and an ethylene / propylene copolymer fraction, this in addition to good general behavior (such as oxidation stability, pour point, etc.)

above all, an improved shear stability corresponding to the stresses occurring in practice today owns

This object is achieved according to invention by a lubricating oil from a Mineralschnüeröl or a synthetic Esterschmieröl and about 45O ⁰ C boiling at atmospheric pressure and an average molecular weight of 1000 to 3000 having Mischpolymerisatfraktion which has been obtained by copolymerizing ethylene and propylene in a molar ratio of between 6: 4 and 3: 7 catalyst of organometallic compounds at a temperature of between -40 ° C and + 8O ⁰ C in the presence of containing an inert atmosphere consists,

The possibility of producing copolymers from ethylene and propylene is known, and their Molar ratio in the presence of catalysts consisting of organometallic compounds between 6: 4 and 3: 7 The catalyst can, if desired, in a solvent containing a saturated hydrocarbon, e.g., heptane, and / or an aromatic hydrocarbon, e.g. B. Contains xylene in an amount that the weight ratio

solvent

Totally dissolved polymer. According to an advantageous embodiment of the According to the invention, the lubricating oils contain 1 to 70 percent by weight of the copolymer fraction.

Furthermore, it is preferred that the invention Lubricating oil as synthetic ester lubricating oil di-2-ethylhexyl, didecyl or dinonyl adipate or contains sebacate.

A lubricating oil preferred according to the invention is also one which contains a copolymer which ίο using a nickel catalyst before Distillation has been hydrogenated to obtain the copolymer fraction.

It has been found that all of the above-described lubricating oils according to the invention are present is mainly due to their viscosity properties, their pour points, their resistance to oxidation and heat and their overall shear strength.

The following examples serve to further illustrate the invention.

example 1

I. It can be a mineral base oil A and about 450 ⁰ C boiling fraction of an ethylene-ZPropylen-copolymer as described above is used. These had the following properties.

between 10: 7 and 1: 3 can be prepared in situ. The copolymerization is carried out in an inert atmosphere, at atmospheric or higher pressure at a temperature between ⁰ -4o C and + 80 ° C. After the catalyst complex has disintegrated and removed, the polymer is filtered and the solvent is evaporated. By vacuum distillation at a pressure below 1 mm Hg, it is possible to collect, among other things about 45O ⁰ C boiling fraction (boiling point at atmospheric pressure equivalent). The average molecular weight of the ^{fraction distilled above 450 °} C. in this way is in the range from 1000 to 3000.

A preferred lubricating oil according to the invention includes an above 45O ⁰ C boiling at atmospheric pressure Mischpolymerisatfraktion which has been obtained by copolymerizing ethylene and propylene in the presence of a of a compound of a heavy metal of the subgroups B of groups IV to VII or Group VIII of the Periodic Table and a catalyst consisting of an organic compound of a metal of groups II or III of the periodic table.

The lubricating oil according to the invention preferably contains a ^{copolymer fraction boiling above 450 °} C. at normal pressure, which has been obtained by copolymerizing ethylene and propylene in the presence of a catalyst consisting of titanium tetrachloride and a trialkylaluminum in a molar ratio of 1: 1 to 10: 1.

A further preferred lubricating oil according to the invention is one which has a more than 450 ⁰ C boiling at atmospheric pressure Mischpolymerisatfraktion which has been obtained by copolymerizing ethylene and propylene in an inert atmosphere at a temperature of -10 ⁰ C to +20 ⁰ C in the presence of a catalyst containing organometallic compounds.

Table I.

(cSt) Oil A Mixed (cSt) poly merisat Viscosity at 37.8 ° C 31.66 2727 Viscosity at 98.9 ° C Crucible) (C) 5.38 158 Viscosity index 105 119 Pour point (C) -9 -9 Flash point (more open 204 306

II. The following preparations were made:

Ci: 97% oil A and 3% copolymer fraction. C ₂ : 75% oil A and 25% mixed polymer fraction. Cj: 60% oil A and 40% mixed polymer fraction.

The properties of these lubricating oils were as follows:

Table II

(cSt) C, C ₂ C ₃ Viscosity at 37.8 ° C (cSt) 37.50 114.4 235 Viscosity at 98.9 ° C 6.11 14.33 25.89 Viscosity index 119 126 126 Pour point (C) -12 -12 -15 Flash point (more open 228 228 235 Crucible) (C)

This makes it possible to use both the viscosity curves / and 98.9 ° C and the viscosity indices (V.I.) as Function of the percentage of mixed polymer fraction

tion to apply. These curves (Fig. 1) show that Table III

Improvement in terms of viscosity index very much

is obtained quickly and remains largely constant from 10% copolymer fraction upwards; the

The thickening effect is more progressive. Curve 1 is>

that of the viscosity t / 37.8 ° C., curve 2 that of the viscosity 7) 98s ° c and curve 3 that of the viscosity index as Function of the percentage of mixed polymer fraction.

III. The preparation C ₂ , which is a motor oil SAE 20-W-40, was subjected to tests to evaluate the shear stability.

Oil A +
Additive

Test time (minutes)
Viscosity drop (%)

25 60
0.04 0.44

25th
15th

(a) Stability, determined according to deTi

"Sonic breakdown test"

This study is that subjecting an oil shear forces that are generated by a 10 kHz oscillator at 200 watts and 98,9 ⁰ C for a> o predetermined amount of time.

The result is given by the expression

(b) Mechanical shear stability

This experiment was carried out by injection pump diesel was allowed the two preparations, namely C2 and the oil with the commercially available additive for 50 hours in a work, the products were heated to 70 ⁰ C. The relative drop in viscosity is defined as the difference between the viscosities of the initial product, measured at 98.9 ° C, and the product at the end of the experiment, based on the viscosity, measured at 98.9 ° C of the initial product. This decrease is zero for preparation C2 and is 25% for the second product.

'/ 0

100

reproduced, where ηο the viscosity at 98.9 ° C before the investigation and η, the viscosity at 98.9 ° C after the investigation.

For comparison purposes, the behavior of the same Oil A with a commercially available additive was used tested, which consists of a high molecular weight polymethacrylate, the amount of added additive, which was 5.6 percent by weight of the oil, was such that it became possible To achieve viscosities and a viscosity index that corresponds to the values of preparation C? comparable was. The following results were obtained:

^2> (c) Stability when attempting a

"Peugeot 204" vehicle

This attempt consists in submitting the oil to mechanical shear forces which are in the 3d gears of the transmission and in the differential one Vehicle »Peugeot 204«, Type XK appear. The machine is on a test stand, and the The attempt lasts 50 hours.

For comparison purposes, an oil A with 5.6% j of the above additive was also used.

The curves of FIG. 2 and 3 show as a function of

Operating time in hours for preparation C2 and for

the oil A with the commercially available additive

on the one hand the changes in the viscosity index (VI) and on the other hand the changes vo Δ

Al.

¹ K)

Viscosity at the time / - viscosity at the start time

Viscosity at the beginning

the viscosities being measured at 98.9 ° C. B ₂ with a content of 32% mixed poly-

Example 2

With the copolymer fraction specified in Example 1 and with a base oil B, the the following oils are made:

Β, with a content of 15% mixed polymer fraction,

merisate fraction,
B3 with a content of 40% copolymer fraction,

the percentages being based on the weight of the B base oil. It became the following results obtain:

Table IV

Viscosity at 37.8 C (cSt)

Viscosity at 98.9 ((cSt)

Viscosity index

Pour point (C)

Flash point (open cup) ((j

8.25 18.84 50.81 74.75 2.06 4.2 8.5 11.2 29 149 137 133 -42 -57 -54 -51 142 156 158 160

10

The curves plotted in FIG. 4 as a function of the percentages of mixed polymer fraction show the rapid improvement in the viscosity index, the thickening effect being more progressive.

Curve 4 is the curve of the viscosity 7737.8-0 curve 5 is the viscosity curve 7) 98.9 ° C and curve 6 is that Curve of the viscosity index as a function of the percentage content of copolymer fraction.

Example 3

To determine the resistance to oxidation and heat in the lubricating oils according to the invention The copolymer fraction contained therein became a product with an average molecular weight of 1500 subjected to differential thermal analysis in a nitrogen and an oxidizing atmosphere. For comparison purposes the same experiment was carried out with a commercially available additive consisting of a Polyisobutylene with an average molecular weight of 1000 existed.

The measurements were made with a commercially available device with a linear heating rate of 1 ° C per minute and a silicone oil as a reference substance.

The thermal stability is characterized by the temperature at which this occurs under a nitrogen atmosphere brought product shows a thermal effect. It shows up with polyisobutylene at 285 ° C, while with the mixed polymer fraction it only occurs at 345 ° C, i.e. a profit is achieved thermal stability of 60 ° C.

In an oxidizing atmosphere at the two comparative products of the oxidation resistance is 135 ⁰ C compared to 315 ° C, so that one thus obtains a gain of 180 ° C in favor of the present in the inventive lubricating oils Mischpolymerisatfraktion.

Example 4

A comparison of the viscosities at the low temperature -17.8 ° C between an im Commercially available oil containing a polyisobutylene type additive (HI) and the mineral oil A, as in Example 1 explains which, according to the invention, contained a copolymer fraction (H2), made.

These two oils were at 98.9 ° C and 37.8 ° C practically the same viscosities. The viscosities at -17.8 ° C were determined according to the method of ASTMD 445-53T, Appendix 4, measured and determined by extrapolation. It became the following results obtain:

55

60

The effective viscosity of the oil Hl at -17.8 ° C, very b5 different from the value obtained by extrapolation, is three times the viscosity of the oil H2.

Table V viscosity
98.9 C at
37.8 C -17.8 C
Measured extra
polished 16.29
16.20 121.90
129.0 30,570
11,510 5,300
6,500 II 1
H 2

Example 5

A synthetic oil was used which consists of bis-2-ethylhexyl adipate, as in Example 1 was mentioned, whereby different proportions were used. The following results were obtained:

20th

25th

30th

35

Table VI Wt% oil 56.7 100 43.3 0 66.9 % By weight copolymer 2200 33.1 1550 86.40 8.18 Viscosity at -17.8 C 64.18 14.20 2.36 extrapolated (cSt) Viscosity at 37.8 ° C 11.40 142 118 (cSt) -54 -60 Viscosity at 98.9 ° C 145 10-W-40 _ (cSt) -54 Viscosity index 10-W-30 Pour point (C) SAE classification

This clearly shows the improvement in the viscosity index; the formation of oils of the Classification SAE 10-W-30 and 10-W-40 is thus possible.

Example 6

It became a synthetic oil made from bis-2-ethylhexyl sebacate used; the copolymer fraction specified in Example 1 was added to this. It the following results were obtained:

Table VII

Wt% oil

77.5 68.5 65.5

% By weight copolymer
22.5 31.5 34.5

Viscosity at -17.8 C 1300 1900 2500 extrapolated (cSt) Viscosity at 37.8 ° C 61.6 90.2 107.2 (cSt) Viscosity at 98.9 ° C 11.5 16.0 18.0 (cSt) Viscosity index 149 146 143 Pour point (C) -57 -54 -54 Flash point (more open 235 236 236 Crucible) (C) SAE classification 10-W-30 10-W-40 10-W-50

For comparison purposes, the same oil was mixed with "Bright Stock solvent" as that Is mineral oil with the best viscosity index in relation to its viscosity. The following Results were obtained:

ίο

Table VIII

% By weight of oil
100

36

% By weight "bright stock solvent" 0 100 64

26 74

Viscosity at 37.8 C (cSt) Viscosity at 98.9 C (cSt) Viscosity index
Pour point (C)
SAE classification

12.61 3.32 154 -60 5 W 524
32.3
98
-12

90.7

11.65

121

-21

20-W-30

The thickening caused by the viscous oil causes a rapid drop in the viscosity index of the preparation and in the best case scenario it is only possible to obtain an oil with the classification SAE 20-W-30.

It was the shear stability of the preparation, which contained 69% oil and 31% copolymer fraction, in one Rosch injection pump type KD 45 SA 53/1 tested under very tough conditions:

Table IX

Oil temperature:
Injection pump inlet pressure:
Injection pump outlet pressure:
50 revolutions per hour.

139.6 15.1 114 -18 SAE 40

70 ⁰ C

250 atmospheres

1 atmosphere

20th

The results are set out in Table IX below.

Duration of the experiment in hours 5 10 20th 40 50 60 0 Oil viscosity at 92.72 92.52 92.47 92.41 92.34 92.07 37.8 C (cSt) 92.80 15.81 15.69 15.66 15.64 15.61 15.57 98.9C (cSt) 15.82 145 145 144 144 144 144 Viscosity index 145 0.26 0.26 0.26 0.26 0.29 0.29 Acid number 0.26 10-W-40 10-W-40 10-W-40 10-W-40 10-W-40 10-W-40 SAE classification 10-W-40 of the oil

The lubricating oils according to the invention with bis-2-ethyl on the part of the generally known stability of the base oils Hexyl sebacate copolymer fractions therefore have 4n of the ester type and the stability of the copolymer perfect shear strength. fraction, which was shown in Example 4.

The oxidation resistance is the result of a

Example 7

Mixtures made up of three basic materials were made, using bis-2-ethylhexyl adipate, a mineral oil D of type 100 "neutral solvent" and the copolymer fractions from Example 1 in the The following weight percentages contained:

Table X

D, D ₂ D ₃

Bis-2-ethylhexyl
Mineral oil D
Mixed polymer fraction

Table XI

0 5 15 25

100 75 65 55

0 20 20 20 A viscosity measurement was carried out at -17.8 ° C in the cold crankshaft simulator performed; this procedure quickly becomes an ASTM procedure under the designation DXXXX-67T. It is a laboratory procedure for determining the actual viscosity of a machine oil at -17.8 ° C at high shear forces. The measurements were made with the device model CCS1, manufactured by Cannon Instrument Co., Philadelphia, USA, carried out. The following results were obtained:

Viscosity at -17.8 C Viscosity at 98.9 C (cSt) Pour point (C)
SAE classification

4.12 -12 32.0
17.7
-39
20-W-50

22.5
16.0
-35
10-W-40

13.0 12.7-45 10 W-30

The unusually low pour points of the ternary mixtures deserve special mention.

Example 8

It is equally possible to produce lubricating oils for transmissions and rear axles with a viscosity that varies, but varies only to a small extent as a function of temperature, such as the mixtures Ei and E ₂ , which are made from a mineral oil G.Type 150 Neutral, and a mixed polymer fraction with the following percentages:

Table XlI

Mineral oil G 100 50 33

Copolymer fraction 0 50 67

These mixes are:

Table XIII

12th

have the following own

Viscosity at 98.9 C (cSt) Viscosity at -17.8 C extrapolated (cSt) Viscosity index pour point (C) SAE classification

5.37 25.0 50 - 21,000 - 105 120 120 -9 -12 -12 _ 80/140 250

For this purpose 2 sheets of drawings

Claims (7)

Patent claims: 1. Lubricating oil consisting of a mineral lubricating oil or a synthetic Esterschmieröl and about 450 ⁰ C boiling at atmospheric pressure and an average molecular weight of 1000 to 3000 having Mischpolymerisatfraktion which has been obtained by copolymerizing ethylene and propylene in a ι ο molar ratio range of between 6 : 4 and 3: 7 at a temperature of between in an inert atmosphere - a organometaüische compounds 40 ⁰ C and + 8O ⁰ C in the presence containing catalyst. 2. Lubricating oil according to claim 1, containing a ^{copolymer fraction boiling above 450 0} C at normal pressure, which has been obtained by copolymerizing ethylene and propylene in the presence of a compound of a heavy metal of subgroups B of groups IV to VII or group VIII of the periodic System and an organic compound of a metal of groups II or III of the periodic table existing catalyst. 3. A lubricating oil according to claim 2, containing an above 45O ⁰ C boiling at atmospheric pressure Mischpolymerisatfraktion which has been obtained by copolymerizing ethylene and propylene in the presence of titanium tetrachloride and a trialkylaluminum in a molar ratio of 1: 1 to 10: existing 1 catalyst. 4. Lubricating oil according to claims 1 to 3, containing a copolymer fraction boiling over 450 ° C at normal pressure, which has been obtained by copolymerizing ethylene and propylene in an inert atmosphere at a temperature of -10 ⁰ C to + 20 ° C in the presence a catalyst containing organometallic compounds. 5. Lubricating oil according to Claims 1 to 4, containing 1 to 70 percent by weight of the copolymer fraction. 6. Lubricating oil according to claims 1 to 5, characterized in that it is a synthetic ester lubricating oil Di-2-ethylhexyl, didecyl or dinonyl adipate or contains sebacate. 7. Lubricating oil according to claims 1 to 6, characterized in that it contains a copolymer, using a nickel catalyst prior to distillation to obtain the copolymer fraction has been hydrogenated.