CS236333B1 - Multigrad oil for lubrication of heavily loaded diesel engines - Google Patents

Abstract

Multigrade oil for lubrication of diesel engines subjected to high thermal loads, viscosity class SAE 20)740, stable in viscosity, performance class API CD, composed of base oil, the significant component of which is high-pressure hydrogenate, and refining additives ensuring its sufficient antioxidant, detergent-dispersant and anti-wear ability and low foaming. The oil meets the conditions of internationally recognized tests in model machines and ensures the complete startability of diesel engines according to Decree 90/75 Coll.

Description

The invention relates to a multigrade oil of constant viscosity, viscosity class SAE 207/40 with a limited max. viscosity of 9.0 Pa.s, measured in a Cold Cranking Simulator at -18°C, and performance class CD according to API for the lubrication of diesel engines subjected to high thermal loads, especially engines with positive cylinder charge, in which the temperature in the first piston groove is greater than 220°C _.

There are many requirements placed on modern oils for lubricating diesel engines under high thermal loads;

Oils must have sufficiently high thermal oxidation stability and alkaline reserve, the lowest possible ash content, low volatility and foaming, sufficiently high protective ability against rust, load-bearing capacity of the lubricating film and lubricity. All-season (multigrade) oils, which enable easy engine starting even at lower outside temperatures, should have high shear stability and thus be constant in viscosity throughout the entire period of use. They may also be required to ensure good wet clutch function.

The preparation of an oil with such complex useful properties is very complex. The balanced required properties are the result of the appropriate composition of the base oil, or rather the properties of its components, and the appropriate composition of refining additives, i.e. antioxidants, anticorrosion agents, anti-wear additives, detergents-dispersants, viscosity and viscosity index modifiers and anti-foam additives.

Each base oil, i.e. oil composed of different types of raffinates with different chemical compositions and different properties, requires a specific composition of mainly antioxidant and detergent-dispersant additives. In particular, base oils whose essential component is the so-called high-pressure hydrogenates (i.e. raffinates prepared by the hydrocracking process under high pressure), whose

-2 238 333 thermo-oxidative stability at temperatures above about 210°C is usually lower than that of high-quality selective raffinates, they require a special composition of antioxidant and mainly detergent-dispersant additives in order to achieve the lowest possible formation of deposits and varnishes. on the surface of the pistons and especially carbon in the first piston grooves. It is important that the added detergent-dispersant additives provide the oil with a sufficiently large alkaline reserve, which is necessary for neutralizing corrosive acidic products from fuel combustion and from thermo-oxidative reactions of the oil. At the same time, however, it is required that the additives create the lowest possible content of ash-forming substances in the oil, since they are also co-creators of deposits on engine parts.

From a chemical point of view, it is important to use their synergistic effect to the maximum when combining antioxidant and detergent-dispersant additives, thus achieving the desired oil performance level with the lowest possible dosage of these additives.

Good rheological properties of the oil over the entire range of engine operating temperatures, i.e. the lowest possible viscosity at low temperatures to enable good fluidity of the oil and easy engine startability and sufficiently high viscosity at high temperatures, depend on the traction composition of the base oil, the amount, type and composition of added polymer viscosity modifiers and viscosity index, which usually also act as pour point depressants, and the composition and amount of added detergent-dispersant additives. The composition of the detergent-dispersant additives must also be adapted to the type and amount of polymer viscosity modifiers and VI used.

Also, satisfactory anti-wear properties of the oil are achieved by using suitable types of antioxidants such as dialkyldithiophosphate, or alkylaryldithiophosphate, zinc, which also affect the friction coefficient of the oil, and thus also have an impact on the function of the "wet" clutch, but it also depends on the composition of detergent-dispersant additives and the fractional and chemical composition of the base oil.

The foaming of the oil is reduced by adding the correct amount of antifoaming agent.

The desired low oil evaporation is a function of the Traction composition of the base oil.

- 3,236,333

The following quality parameters and test results were determined for the oil that is the subject of this invention:

SAE viscosity grade 20W40 API Performance Class CDs Kinematic viscosity, mm^.s“^ at 100°C 14.5 - 16.3 Dynamic viscosity (measured in Cold Cranking Simulator), Pa.s at -18°C max. 9.0 Viscosity index (ČSN 65 6218) min· 125 Open cup flash point (ČSN 65 6212) min· 215 Freezing point (ČSN 65 6072) max. -30°C Evaporation (according to Noack) (DIN 51 581) max. 15% wt. Total Alkalinity (TBN) (ČSN 65 6069) min. 10 mgKOH/g ISO color (ČSN 65 6076) max 6.5 Foaming (ASTM D 892) at 24°C max. 25 ml 93°C max. 150 ml 24°C after 93°C max. 25 ml

Foam stability (ASTM D 892)

Water content (ČSN 65 6062) and mechanical impurities (ČSN 65 6219) Sulphated ash (ČSN 65 6221) Carbonation residue (ČSN 65 6210)

0/0/0 ml max. 1.7% wt. max. 2.0% wt.

Protective ability against rust at 60°C/24 h (ČSN 65 6249) complies

Shear stability after 30 cycles in Bosch injector (DIN 51 382)

decrease in viscosity by max. 12% Petter W1 Motor Test Piston ring sealing (points) 10 Piston jacket (points) min. 9.5 Connecting rod bearing loss (mg) max. 25 Motor test Petter AVB Piston ring sealing (points) 10 Settlements in the 1st piston groove (points) min. 4.0 Total points min. 80

236,333

Cam and valve lifter wear test S 720 (UVMV)

Cam wear, jma Lifter wear, jom

Volvo B 20 test

Total wear of cam and lifter, jata.

Startability test according to Decree 90/75 Coll. at -15°C in the T3-930 engine in the ŠBfl-638 engine

Caterpillar T0-2 Wet Clutch Impact Test

Extension of the time required to stop the rotating part of the transmission after 15,000 cycles max. 1.5 max. 4.0 max. 150 and no pitting passes passes max· by 15%

The essence of the invention is the composition of an engine oil that meets the stated quality parameters and is made from a base oil whose significant component is a high-pressure hydrogenate.

Example 1

An oil was prepared consisting of 81.497% by weight of base oil and 18.503% by weight of refining additives. The base oil consisted of 50% by weight of high-pressure hydrogenate with a viscosity of 6.2 mm .s“· ¹ at 100°C and a VI of 105, 35% by weight of selection raffinate with a viscosity of 7.2 mm^.s“^ at 100°C and a VI of 87 and 15% by weight of residual

-1 selection raffinate with a viscosity of 25»3 mm .s at 100°C and with a VI of 84. To this base oil were added refining additives (commercial products - oil concentrates) in the following composition and quantity (% wt):

Dialkyldithiophosphate Zn with n-alkyl Cg (Oloa 3269 A) 0.9 Dialkyldithiophosphonate Zn with n-alkyls and 0.5 (Oloa 267) Petroleum alkylaryl sulfonate Ca with TBN 10 mg KOH/g 3.5

(Petrosulfonate 30)

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Alkylphenol sulfide Ca with TBN 250 mg KOH/g 1.5 (Oloa 219) Alkyl salicylate Ca with TBN 160 mg KOH/g 3.5 (AC 600 Bissuccinimide (Oloa 3373C7 5.2 Styrene-isoprene copolymer as 100% substance (Shellvis 50) 0.4 Dispersion polymethacrylate (Plexol 956) 3.0 . Silicone oil (MS 200) 0.003 The prepared oil had the following quality parameters: Kinematic viscosity, mm ,s~ at 100°C 15.08 Dynamic viscosity (CCS), Pa.s at -18°C •8.9 Viscosity index 131 Flash point (OK), °C 222 Freezing point, °C -38 Evaporation (Noack), % 12.1 TBN, mg KOH/g 10.95 ISO color 6.5 Foaming, ml at 24°C 0 93°C 120 24°C after 93°C 0 Foam stability, ml 0/0/0 Water and mechanical impurities content 0 Sulfated ash, % wt. 1.59 Carbonation residue, wt.% 1.68 Protective ability against rust conforms Shear stability in Bosch injector after 30 cycles % viscosity decrease 6.7

This oil has been subjected to a series of tests on model machines.

Petter W1 Motor Test (points):

Piston jacket 9.9 (minimum limit 9.5 points) Piston groove area 9^7 Piston grooves 9.4 Subtotal 29.0

Clogging of wiper ring cutouts Piston bottom

Inside of piston jacket

Piston ring seizure Loss of piston bearing weight

- upper half

- lower half

- total

Increase in oil viscosity measured

9.8 (mg) (limit

236,333

10.0 points) (limit max. 25 mg)

at 100°C, by % 9.1 Motor test Petter AVB (points): First groove 4.3 First bridge 9.3 Second groove 7.1 Second bridge 9.9 Third groove ' 10.0 Piston sleeve 10.0 Piston bottom from inside 8.4 Total 59.0 Total points, 84.3 (Sum x 10/7) Cam wear tests and valve lifters: Examination Š 720 (ÚVMV method) Cam wear,yan 0.9 (limit Jack wear, jum 2.7 (limit

(limit min. 4.O points) (limit min. 80.O points) max. 1.5 jum) max. 4.0yim)

Volvo B 20 test

Total cam wear, jum 38

Total wear of the jacks^am 63

Total wear, jam 101 (limit max. 150jum)

Pitting of the lifters does not occur (limit max. 10)

Clutch impact test (Caterpillar TO-2 test)

Extension of the time required after stopping the rotating part of the transmission after 15,000 cycles, by % 11 (limit max. by 15%)

- 7 Engine startability test

236 333 at -15 °C according to Decree 90/75 Coll.

- in the T3-93O engine

- in the ŠM-638 engine it complies with it

Example 2

An oil was prepared with the same composition as in Example 1, but instead of 0.9% of the C6 alkyl Zn dialkyldithiophosphate (Oloa 3269 A), 2.6% of the C6 alkyl Zn dialkylaryl dithiophosphate (Oloa 260) was added in addition to 0.6% of the C6 alkyl Zn dialkyldithiophosphate (Oloa 267) and instead of the Ca alkyl salicylate (AC 6OC), the same amount (3.5% by weight) of the medium-basic Ca alkylphenol sulfide with a TBN of 150 mg KOH/g was added.

The quality parameters of the oil prepared in this way and the test results in model machines were similar and satisfactory as for the oil given in Example 1.

Claims (1)

SUBJECT OF THE INVENTION 236 333 Multigraded oil for lubrication of heavily loaded diesel engines, viscosity class SAE 20W40 with a viscosity limit of max. 9.0 Pa. with at -18 ° C, measured in a Cold Cranking Simulator and API CD performance class, characterized in that it consists of 75-83% hJW of the base oil whose 40-60% w / w. the proportion is a high pressure hydrogenate having a viscosity of 5.5-6.5 m ² s -1 at 100 ° C and a VI min. 100 and the remainder is a mixture of select raffinates with viscosities from 7.0 to 30.0 mm ² · s · 2 at 100 ° C and with VI min. 82, from 17 to 25% by weight of potting refining ingredients in the composition of 0.8 to 1.4% by weight; dialkylditiofosfátu Zn with ^n-C8 alkyl ^{"or C} 10 ^{and 2.2%} ^ ² * alkylarylďitiofosfátu ^IIM% Zn, 0.2 to 0.6 wt%. dialkyl dithiophosphate Zn with C 1 -C 8 alkyls, 1.0 to 5.0% w / w alkylarylsulfonate Ca with TBN 5 to 400 mgKOH / g, 1.0 to 5.0% hmetalkylphenolsulfide Ca with TBN 220 to 280 mgKOH / g, 1.0 to 5.0% Ca-alkylsalioylate Ca with TBN 120 to 185 mgKOH / g or 1.0 to 5.0% Ca-methylphenyl sulfide Ca with TBN 120 to 185 mgKOH / g, 3.0 to 6.0% hmetbissukoinimide preferably containing boron, or a mixture of bissukoinimide and monosuccinimide in a ratio of 2 to 3: 1, 0.3 to 0.8% of a styrene-diene mug copolymer, i.e. styrene-isoprene or styrene-butadiene, such as 100%, 0.5 up to 2.0 wt. % polyisobutylene, 2.5-5.0% wt polymethacrylate, preferably of the dispersion type, and 0.002-0.004% hmet. silicone oil as antifoam additives.