DE1282824B - Lubricating oil - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

ΐΓΪΊΐ

GERMAN #lft PATENT OFFICE Int. Cl .:

ClOm

EDITORIAL

German class: 23 c-1/01

Number: 1 282 824

File number: P 12 82 824.9-43 (B 74497)

Filing date: November 30, 1963

Display day: 1.4. November 1968

Lubricating oil

CO
CxI
CO
CnJ

It is known that certain olefin polymers are effective in improving the VI of lubricating oils, when added to them in small amounts. The best known of these additives is polyisobutylene. However, these known additives have the disadvantage that they are not very stable against shear with the lubricant suffering a decrease in both viscosity and VI. While Shear stability in modern machine oils, which must have a very high VI, is important it is even more important for gear oils. Gear oils, especially rear axle oils, are in use subject to heavy shear forces and are often used considerably longer than machine oils, so that although a very high VI is not as important for gear oils as it is for machine oils, it is very desirable that a moderately high VI gear oil not be essential in use Reduction in VI or viscosity suffers.

It has now been found that the VI and the shear instability of a lubricating oil significantly improve if a mineral or synthetic lubricating oil 0.1 to 25%, in particular 0.1 to 10%, based on the weight of the mixture, a solid or semi-solid polymer of 4-methylpentene-1 (4-MP-l) with an intrinsic viscosity of 0.1 to 1.5, in particular 0.1 to 1.0, the monomer in the presence of a Friedel-Crafts catalyst at 20 to -120 ° C, preferably 0 to -120 ° C, prepared has been contains. The limiting viscosity number (LVN) is defined as

N ~ - N lim - »0 of

N ₀ C

where N is the viscosity of the polymer dissolved in decalin at 130 ° C., N ₀ denotes the viscosity of the decalin and C denotes the concentration of the polymer in grams per liter, determined at various concentrations and extrapolated to concentration 0.

The intrinsic viscosity of a polymer can be used in a known manner to obtain a very high to provide a raw guide to the average molecular weight of the polymer. Polymers with an LVN of 0.1 have a molecular weight in the region of 6000, those with an LVN of 0.5 have a molecular weight in the region of 50,000; but it must be noted that these values are only are very approximate. The shear stability of the polymers appears to be inversely related to the LVN change, those with lower LVN are scher notifiers:

The British Petroleum Company Limited,

London

Representative:

Dr. W. Koch and Dr. R. Glawe, patent attorneys,

2000 Hamburg 52, Waitzstr. 12th

Named as inventor:

James Keith Hambling,

John Mansel Squire,

John Frederick Ford,

Sunbury-on-Thames, Middlesex (Great Britain)

Claimed priority:

Great Britain 4 December 1962 (45 787)

more stable than those with high LVN. On the other hand, the polymers with lower LVN give less improvement des VI than the polymers with higher LVN. In the case of a gear oil, one generally improves Polymer with an LVN in the range 0.1 to 1.0, especially 0.1 to 0.5, the VI of a refined one Lubricating oil and it has good shear stability. With a machine oil it may be necessary use more polymer or a polymer of higher LVN to meet a given VI setpoint, but in the latter case it must be noted that there is a certain loss of shear stability.

The LVN of the polymer additives used in the present invention depends primarily on the temperature at which the polymerization was carried out. In general, higher temperatures in the ranges given above lead to polymers of lower LVN, and vice versa. For example, lead polymerization temperatures in the range 0 to -6O ⁰ C generally for the production of polymers having LVN approximately in the range of 0.1 to. 1

The amount of polymer added to the base oil, of course, depends mainly on the grade the required improvement of the VI. Modern petroleum base oils usually become too a fairly high VI refined, say 85 to 110, and synthetic oils have good ones too VI, so that very small amounts of polymer, e.g. B. 0.5 to 7.5 percent by weight, may be sufficient to the To meet VI requirements of the final mixture. A modern multi-grade gear oil (e.g. a SAE 80/90 degrees) usually has a VI in the region of 110 to 120, and a modern multi-degree

809 637/878

Machine oil usually has a VT in the region of 120 to 145.

Friedel-Crafts catalysts suitable for carrying out the polymerization reaction are aluminum chloride, Aluminum bromides boron trifluoride, hydrogen fluoride, titanium tetrachloride, tin (IV) chloride and Boron tribromide. The catalyst concentration can usually be that in such polymerization reactions used to be. For example, in the case of "aluminum chloride is a suitable concentration range 0.1 to 2 percent by weight, preferably 0.3 to 1.5 percent by weight, based on the weight of the Monomers.

The polymerization reaction is usually carried out in a solvent. Preferred Solvents are hydrocarbon solvents (e.g. n-heptane), halogenated hydrocarbon solvents (e.g. ethyl chloride or methyl chloride) and liquid sulfur dioxide. The polymer can be manufactured by adding a dilute solution (e.g. 0.5 to 5 percent by weight) of the catalyst in a solvent is added to a mixture of 4-MP-l and solvent, the concentration of 4 MP-1 in the total mixture preferably is between 10 and 50 percent by weight. The polymerization reaction is usually in 30 seconds up to 1 hour completed, and the polymer can be recovered by passing the solvent through Steam is removed and the polymer is dried by heating under vacuum or by the Polymer is precipitated in methanol or acetone and dried by heating under vacuum.

The polymers of 4-MP-1 prepared as described are at normal temperatures solid or semi-solid. It can be difficult to find those with higher molecular weights in lubricating oils to solve; in that case it is advantageous to use them in the form of a solution in n-heptane, trichlorethylene or to add another suitable solvent, the solvent then of the Lubricating oil is evaporated. For this purpose, the solution of polymer in solvent, which in the Polymerization reaction incurred, can be used.

The mixture according to the invention can of course also contain other lubricating oil additives, as are customary are used, contain, e.g. B. antioxidants, detergents and EP additives.

For example, a number of lubricant blends have been made in accordance with the invention from the following base oils and polymers.

Base oils X and Y

These were fully refined base oils obtained from Middle East crude oils.

Polymers

The polymers were prepared by adding a 10% solution of AlCl ₃ in ethyl chloride to a mixture of 4-MP-1 and heptane. Upon completion of the reaction, methanol was added to deactivate the catalyst and the polymer was precipitated by adding acetone. The response variables are given in Table 1.

Table 1

Poly
mer Weight
percent
from
4-Mp-l
in the Reak
functional
mixture React
functional
tempe-
rature
° C Reak
ions
Time
Minutes Conversion
ment of
4-MP-l
° / o LVN 1
2
3
4th
5
6th 30th
20th
20th
20th
20th
30th 0
-20
-20
-30
-40
-25 45
45
15th
15th
15th
45 76
38
90
92
82
94 0.20
0.30
0.42
0.50
0.60
0.50

Kinematic Viscosity (KV) and VI were determined on the base oils and blends of the invention and the results are given in Table 2 below. Some results of a shear stability test are also recorded, in which the oil containing the polymer is pumped through a narrow opening at high pressure, so that a degree of shear on the order of 10 ⁷ see " ^{1 is} generated at the opening Oil is measured after 1,100 and 250 revolutions through the orifice, LG Wood gives a full description of the apparatus and procedure in the British Journal of Applied Physics, 1950, Vol. I, p. 202. Results of tests are also given using two commercially available polyisobutylene additives to improve the VT (see Table 2) for lubricating oils.

Tabel

Base oil polymer polymer KV VI Shear stability Rounds 100 Rounds 250 ° / o decrease concentration at
99 ° C _ to VI,
contribution mixture in the
mixture no no of the polymer X _ Weight cSt 103 »/ 0 loss of 99 ° C KV,
Contribution of the polymer according to - - after 250 rounds X 1 percent 6.53 118.5 4.0 6.5 _ X 2 12.4 122.0 Circulation 1 11.0 14.5 no A. X 3 6.30 12.4 124.5 13.0 17.5 - B. X 4th 4.5 12.4 125.5 no 9.5 13.3 5.1 C. X 5 3.25 12.4 126.0 - 32.5 37.5 8.4 D. X 6th 2.60 12.4 125.5 1.0 29.2 35.2 9.1 E. X PIBI * 2.35 12.4 126.5 3.0 5.2 F. X PIB2 * 2.80 12.4 126.0 3.0 18.2 M. 3.05 12.4 2.7 20.5 N 2.95 16.0 11.2

* A commercially available polyisobutylene to improve viscosity index.

5 6

It can be seen that the mixtures according to the invention motor vehicles. One of the most important requirements The very much improved VI compared with the nits of such an oil is that it is a good shear base oil, that were used in them, had stability, and to improve this characteristic and in addition, if the mixtures were essentially covered, a test on the rear axle became one borrowed unaffected by shear while the 5 Ford Zephyr ran using an oil Lubricant blends which became the commercial ones that meet the SAE 80/90 Viscosity Requirement VI improvers contained, was very sensitive to gene mixed and a commercial EP-Addi-Shear are. This sensitivity to vision contained, as this normally occurs in a hindrance is necessary from the other well-known class of terax oil. The actual coexistence commercially available VI improvers, namely the io setting (P) was:

Polymethacrylates, divided. For example, a _{base oil γ g2 showed 5 percent by weight}

2 percent by weight solution of a polymethacrylate polymer 1 10 0 percent by weight

in the form of a commercially available additive for EP additive 75 percent by weight

Lubricating oils to improve the VI in base oil X '

a loss of KV at 99 ° C on polymer 15 A 5000 mile test was run and es

is due, samples of the oil were periodically taken from 25% after one cycle and

and of 48% after 250 revolutions, if it is determined on them KV and VI, as shown in Table 3

Shear stability test was checked. will show. The base oil Y had a KV at 99 ° C

The main application of a multi-gear transmission of 8.1 cSt and a VI of just under 100. The

Oil is the one had to lubricate the hypoid gears and ao mixture of base oil Y and EP additive alone

the spiral bevel gears in the rear axles have a KV at 99 ° C of 8.5 cSt.

Table 3

0 200 400 at
600 the test
800 ng back]
1000 (laid I.
1500 share
2000 3000 4000 5000 KV at 99 ° C
VI 21.44
115 20.05
115 19.46
114 19.16
113 18.84
113 18.66
113 17.68
114 17.63
112 16.86
113 17.38
111 16.95
110 «/ Ο loss of the
Mixture of KV
at 99 ° C as a result
polymer 10.7 15.3 17.6 20.1 21.4 29.0 29.4 25.3 31.5 34.4

The above results represent the results obtained using 10 percent by weight of one VI improver, which is to be regarded as the best of the known commercially available, instead of polymer 1 er 40 will hold, favorably as there is a 51% loss of KV at 99 ° C after 5000 miles.

The load properties of Mixture P were assessed by a Shell four-ball test and were found to be satisfactory. Results of the test are compared in Table 4 indicated with a commercially available SAE-90-EP-Ö1.

Table 4

Mixture P

SAE 90 EP Ol

Medium Hertz load

2V2 second seizure delay load

Sweat load

Initial stress

65.2 kg
150 to 200 kg
340 kg
100 kg

62.4 kg 144 kg 300 kg

95 kg

Claims (1)

Claim: 55 Lubricating oil with a viscosity index of 85 to 110, containing a homopolymer of a 1-olefin, characterized in that it is a solid or semi-solid polymer of 4-methylpentene-1 with an intrinsic viscosity of 60 from 0.1 to 1.5, with the monomer in the presence of a Friedel-Crafts catalyst at -120 has been polymerized to 20 ° C, contains. References considered: British Patent Nos. 761 359, 810 210; U.S. Patent No. 2,534,095. 809 637/878 11.6S © Bundesdruckerei Berlin