LUBRICANTS LEADING TO BETTER EQUIPMENT CLEANLINESS

Abstract

The present invention relates to the field of lubricants. In particular, the present invention is directed to the use of lubricant compositions comprising a synthetic ester having an Iodine value lower than 10 g I/100 g measured according to DGF CV 11b for the reduction of deposit formation.

Claims

1-15. (canceled)

16. Use of a lubricating composition for reducing the formation of deposits, wherein the composition comprises (i) at least one lubricating base oil, and (ii) at least one synthetic ester having an Iodine value lower than 10 g I/100 g measured according to DGF C-V 11b.

17. Use according to claim 16, wherein the synthetic ester is selected from (a) a diester of a dicarboxylic acid, (b) a polyol ester, or (c) mixtures thereof.

18. Use according to claim 16, wherein the diester of the dicarboxylic acid is selected form the group consisting of di-(isopropylheptyl)-adipate (DPHA), di-isodecyl adipate (DIDA), diisotridecyl adipate (DITA), diisononyladipate (DNA) or mixtures thereof.

19. Use according to claim 16, wherein the lubricating base oil is selected from Group I, Group II, Group III base oils according to the definition of the API, or mixtures thereof.

20. Use according to claim 16, wherein the composition further comprises one or more other additives selected from the group consisting of viscosity index improvers, polymeric thickeners, antioxidants, corrosion inhibitors, detergents, dispersants, anti-foam agents, dyes, extreme pressure additives, antiwear additives, friction modifiers, metal deactivators, pour point depressants and the like.

21. Use according to claim 16 wherein (a) the deposits are determined according to the TEOST MHT D7097 test, or (b) the deposits are measured according to ASTM D4310.

22. Use according to claim 16, wherein the oxidation stability measured according to HPDSC test is increased compared to a composition wherein the synthetic ester has been replaced by a lubricant base oil selected from Group I, Group II, Group III base oils or mixtures thereof.

23. Use according to claim 16, wherein the Noack volatility measured according to ASTM D5800 is decreased compared to a composition wherein the synthetic ester has been replaced by a lubricant base oil selected from Group I, Group II, Group III base oils or mixtures thereof, and wherein preferably the Noack volatility is below 12% weight loss, or equal or below about 10% weight loss.

24. Use according to claim 16, wherein the dynamic viscosity determined at 35 C. according to ASTM4684 is at least about 100 mPa*s lower compared to a formulation wherein the synthetic ester has been replaced by a lubricant base oil selected from Group I, Group II, Group III base oils or mixtures thereof.

25. A lubricating composition comprising (i) at least one base oil selected from a Group I oil according to the API classification, (ii) a synthetic ester having an Iodine value lower than 10 g I/100 g measured according to DGF C-V 11b, and (iii) optional further additives.

26. A lubricating composition comprising (i) at least one base oil selected from a Group I, Group II oil according to the API classification, or a mixture thereof (ii) a synthetic ester having an Iodine value lower than 10 g I/100 g measured according to DGF C-V 11b, (iii) optional further additives.

27. The lubricating composition according to claim 25, wherein the synthetic ester is a diester of a dicarboxylic acid, and wherein preferably the diester of the dicarboxylic acid is selected from the group consisting of di-(isopropylheptyl)-adipate (DPHA), di-isodecyl adipate (DIDA), diisotridecyl adipate (DITA), diisononyladipate (DNA) or mixtures thereof, and preferably is di-(isopropylheptyl)-adipate (DPHA).

28. A method for reducing deposit formation in a lubricating composition comprising a base oil comprising at least one Group I, Group II, or Group III base oil or mixtures thereof, comprising adding a synthetic ester having an Iodine value lower than 10 g I/100 g measured according to DGF C-V 11b to said lubricating composition.

29. The method according to claim 28, wherein the synthetic ester is added after the lubricating base oil is present in the equipment.

30. The method according to claim 28, wherein the synthetic ester is a diester of a dicarboxylic acid, and wherein preferably the diester of the dicarboxylic acid is selected from the group consisting of di-(isopropylheptyl)-adipate (DPHA), di-isodecyl adipate (DIDA), diisotridecyl adipate (DITA), diisononyladipate (DNA) or mixtures thereof, and preferably is di(isopropylheptyl)-adipate (DPHA).

Description

EXAMPLES

[0206] Methods

[0207] The various viscosities of the lubricant compositions according to the present invention have been determined following established industry standards:

[0208] The kinematic viscosity at 100 C. is determined according to the ASTM D445.

[0209] The yield stress and the low temperature viscosity at 35 C. is determined according to ASTM D4684.

[0210] HPDSC Measurements:

[0211] For the HPDSC measurements a small quantity of the lubricant composition sample to be tested is weighted into a sample pan and placed into the test cell. The test cell is adjusted to the desired temperature and then pressurized with oxygen to the desired oxygen pressure.

[0212] HPDSC ramping method: A heating rate of 5 C./min was used for this method.

[0213] HPDSC OIT method: The OIT was determined at a temperature of 210 C. at oxygen pressures of 155 psi and 200 psi, respectively.

[0214] Composition of Conventional 5W-20 Formulation (Formulation 1)

[0215] The composition of the 5W-20 formulation applied is shown in Table 1:

TABLE-US-00005 TABLE 1 Component Component type Amount (wt.-%) Irgaflo 649p Pour Point Depressant 0.300 Additive package 9.430 EHC 45 (Exxon Mobil) Base oil 67.070 EHC 60 (Exxon Mobil) Base oil 20.000 Infineum V534 Viscosity modifier 3.200

[0216] The components of the 5W-20 formulation have been combined and blended for 1 hour at 50 C. prior to use.

[0217] Composition of the Additive Package

[0218] The composition of the additive package is shown in Table 2:

TABLE-US-00006 TABLE 2 Component Component type Amount (wt.-%) Infinuem C9268 Dispersant 35.5673 Antifoam agent Antifoam 0.0530 Diluent* Diluent 11.0604 Infineum C9330 Detergent 18.8982 Infineum C9417 Anti-wear 10.5610 Irganox L135 Antioxidant 9.0138 Irganox L57 Antioxidant 14.8462

[0219] The additive package is obtained by the following procedure: To the blend of Infinuem C9268, the anti-foam agent and the diluent, Infineum C9330 is given and further blended for 1 h at 95 C. Subsequently Infineum C9417 is added and the mixture is further blended for 1 hour at 70 C. Irganox L135 and Irganox L57 are added and the resulting mixture is blended for an additional hour at 60 C.

Example 1: Determination of Deposits According to the TEOST MHT D7097 Test

[0220] To compare the deposit formation of an inventive composition and a comparative composition, conventional 5W-20 motor oil formulations (Formulation 1) have been applied. In the comparative composition, to the 5W-20 oil formulation a mixture of a Group III mineral oil and an additive package have been added (resulting in Formulation 2), while in the inventive formulation (Formulation 3), a diester of a dicarboxylic acid (DPHA) and an additive package have been applied. The formulations are listed in Table 3:

TABLE-US-00007 TABLE 3 Formulation 2 Formulation 3 Component (comparative) (wt.-%) (inventive) (wt.-%) Formulation 1 75.00 75.00 Nexbase 3030 (group 22.64 III base oil) DPHA 22.64 Additive package 2.36 2.36

[0221] The composition of the additive package used in the present example is provided above.

[0222] The test procedure is described below:

[0223] Test Protocol: Fuel economy testing on the engine dynamometer was conducted using a 5.7 L GM crate engine with a high volume oil pan. The engine was run at controlled steady state conditions simulating highway temperatures, speed and load. Fuel consumption was measured constantly with a Coriolis type fuel flow meter. After a specific aging period where oil viscosity and fuel consumption were stabilized, a measured amount of candidate was added to the crankcase. Fuel economy percent benefit was calculated from consumption values before the addition of the additive to the end of test. At end of test, Rocker Covers, Cam baffles, Oil Pan, Oil Screen and Front Cover are removed for visual inspection and photos of deposit formation. [0224] Base Oil6 quarts (corresponding to about 5678 ml) of Formulation 1 (5W20 motor oil formulation) [0225] Candidate2 quarts (corresponding to about 1893 ml) of a mixture of DPHA and additive package used in Formulation 3 (together 25 wt.-% DPHA and additive package), or 2 quarts (corresponding to about 1893 ml) mixture of Nexbase 3030 and additive package used in Formulation 2 (25 wt.-% Nexbase 3030 and additive package)

[0226] Oil Sampling has been performed as follows: [0227] 28.25 hourstake 20 ml sample for viscosity measurements [0228] 28.50 hoursAdd 2 quarts of Candidate [0229] 28.75 hours(15 minutes after candidate addition) 1 quart sample [0230] 90.00 hoursEnd of Test, take 1 quart sample and save all drain oil

[0231] The following test cycle has been followed: [0232] 1. Run Highway Cycle (2500 rpm, 35 Nm Torque, 125c oil) for 12 to 16 hours overnight till fuel consumption is stable. [0233] 2. Run and measure fuel consumption. [0234] 3. Follow Oil Sampling procedure above [0235] 4. Continue test to 90 hours with fuel consumption measurements. [0236] 5. At 90 hours end of test (EOT), take 1 qt. sample. (save drain oil) [0237] 6. When engine is cool enough to work on, remove and display RAC's, front cover, cam baffles, oil pump and oil pan for inspection and photos. Notify test engineer.

[0238] The results of the various tests of Formulations 1, 2 and 3 are summarized in Table 4 below:

TABLE-US-00008 TABLE 4 Formulation Formulation Formulation Formulation Formulation Formulation 1 2 2 (end of test) 1 3 3 (end of test) Kin. viscosity 8.277 6.276 7.472 8.366 6.649 7.004 at 100 C. (mm.sup.2/s) MRV/yield stress (Pa) Y 35 Y 35 Y 35 Y 35 Y 35 Y 35 MRV*/viscosity 8913 6030 8386 8913 5860 6786 (mPa*s) Noack volatility** 12 8.7 7.6 7 (wt.-% loss) HPDSC.sup.# ramping ( C.) 155 psi O.sub.2 246 256.2 200 psi O.sub.2 243.8 n/a HPDSC.sup.## OIT (min) 155 psi O.sub.2 41.43 84.99 200 psi O.sub.2 37.26 79.65 Deposits*** rod (mg) 30 6.6 Deposits*** filter 2.4 2.3 (mg) Total deposits*** 32.4 8.9 Formulation (mg) *MRVMini Rotary Viscosimeter (measurements at 35 C. according to ASTM D4684) **The Noack volatility is measured according to ASTM D5800 B ***Deposits are measured according to the TEOST MHT D7097 test. The total deposits are obtained by summing up rod deposits and filter deposits. .sup.#High Pressure Differential Scanning Calorimetry (HPDSC): ramping was performed with 5 C./min. .sup.##HPDSC: oxidation induction time (OIT) measured at 210 C.

Example 2: Determination of Deposits According to ASTM D4310

[0239] Furthermore, the synthetic ester of the invention was tested in a turbine oil formulation. To a typical Group I mineral oil formulation has been added DPHA. With this formulation a turbine test according to ASTM D4310 has been performed. The composition of the formulations tested are summarized in Table 5 below:

TABLE-US-00009 TABLE 5 Component Formulation 4 (wt.-%) Formulation 5 (wt.-%) Group I oil* 99.57 89.57 DPHA** 0.0 10.00 Additive package*** 0.43 0.43 *A mixture of 65% AP/E CORE 150 and 35% AP/E CORE 600 was used as a Group I mineral oil. AP/E CORE 150 and AP/E CORE 600 are commercially available from Exxon Mobil. **Synative ES DPHA from BASF SE ***Irgalube 2030A from BASF SE

[0240] The kinematic viscosity at 100 C. of formulation 4 was 6.82 mm.sup.2/s. The kinematic viscosity at 100 C. of formulation 5 was 6.25 mm.sup.2/s.

[0241] The sludge determined according to ASTM D4310 was 65.1 mg for Formulation 4 (comparative) and 46.6 mg for Formulation 5 (inventive).

[0242] Preferred embodiments of the present invention are described in the following items: [0243] 1. Use of a lubricating composition for reducing the formation of deposits, wherein the composition comprises [0244] (i) at least one lubricating base oil, and [0245] (ii) at least one synthetic ester having an Iodine value lower than 10 g I/100 g measured according to DGF C-V 11b. [0246] 2. Use according to item 1, wherein the synthetic ester is selected from [0247] (a) a diester of a dicarboxylic acid, [0248] (b) a polyol ester, or [0249] (c) mixtures thereof. [0250] 3. Use according to items 1 or 2, wherein the dicarboxylic acid moiety of the diester of the dicarboxylic acid is selected from the group consisting of phthalic acid, succinic acid, alkyl succinic acids and alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acids, alkenyl malonic acids, glutaric acid, diglycolic acid, 1,4-cyclohexanedicarboxylic acid, 2,6-decahydronaphthalenedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid and mixtures thereof. [0251] 4. Use according to any one of the items 1 to 3, wherein the dicarboxylic acid moiety of the diester of the dicarboxylic acid is an aliphatic dicarboxylic acid and is preferably selected from the group consisting of succinic acid, alkyl succinic acids and alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acids, alkenyl malonic acids, glutaric acid, 1,4-cyclohexanedicarboxylic acid, 2,6-decahydronaphthalenedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid and mixtures thereof, and more preferably is adipic acid. [0252] 5. Use according to any one of items 1 to 4, wherein the ester moiety of the diester of the dicarboxylic acid is independently selected from the structure of formula (I)

##STR00005##

[0253] whereas q, r and s are defined as follows,

[0254] q+r=4 to 9,

[0255] s=0 to 5,

[0256] q=1 to 8, and

[0257] r=1 to 6. [0258] 6. Use according to any one of the items 1 to 5, wherein the diester of the dicarboxylic acid is selected form the group consisting of di-(isopropylheptyl)-adipate (DPHA), di-isodecyl adipate (DIDA), diisotridecyl adipate (DITA), diisononyladipate (DNA) or mixtures thereof, and preferably is di-(isopropylheptyl)-adipate (DPHA), diisononyladipate (DNA) or mixtures thereof. [0259] 7. Use according to any one of the items 1 to 6, wherein the amount of diester of the dicarboxylic acid is from about 5 wt.-% to about 50 wt.-%, from about 5 wt.-% to about 40 wt.-%, from about 5 wt.-% to about 30 wt.-%, from about 8 wt.-% to about 28 wt.-%, from about 9 wt.-% to about 25 wt.-%, or from about 17 wt.-% to about 25 wt.-% based on the weight of the composition. [0260] 8. Use according to any one of items 1 to 7, wherein the lubricating base oil is selected from Group I, Group II, Group III base oils according to the definition of the API, or mixtures thereof, and preferably is selected from Group I, Group II base oils, or mixtures thereof. [0261] 9. Use according to any one of items 1 to 8, wherein the composition further comprises one or more other additives selected from the group consisting of viscosity index improvers, polymeric thickeners, antioxidants, corrosion inhibitors, detergents, dispersants, anti-foam agents, dyes, extreme pressure additives, antiwear additives, friction modifiers, metal deactivators, pour point depressants and the like. [0262] 10. Use according to any one of items 1 to 9 wherein the deposits are determined according to the TEOST MHT D7097 test. [0263] 11. Use according to any one of items 1 to 10, wherein the deposits are reduced by at least about 5 mg, by at least about 7 mg, by at least about 10 mg, by at least about 15 mg measured according to the TEOST MHT D7097 test compared to a composition wherein the synthetic ester has been replaced by a lubricant base oil selected from Group I, Group II, Group III base oils or mixtures thereof. [0264] 12. Use according to any one of items 1 to 9 wherein the deposits are measured according to ASTM D4310. [0265] 13. Use according to any one of items 1 to 9 and 12, wherein the deposits measured according to ASTM D4310 are less than about 60 mg, less than about 55 mg, or less than about 50 mg. [0266] 14. Use according to any one of items 1 to 13, wherein the oxidation stability measured according to HPDSC test is increased compared to a composition wherein the synthetic ester has been replaced by a lubricant base oil selected from Group I, Group II, Group III base oils or mixtures thereof. [0267] 15. Use according to any one of items 1 to 14, wherein the Noack volatility measured according to ASTM D5800 is decreased compared to a composition wherein the synthetic ester has been replaced by a lubricant base oil selected from Group I, Group II, Group III base oils or mixtures thereof. [0268] 16. Use according to any one of items 1 to 15, wherein the Noack volatility is below 12% weight loss, or equal or below about 10% weight loss. [0269] 17. Use according to any one of items 1 to 16, wherein the dynamic viscosity determined at 35 C. according to ASTM4684 is at least about 100 mPa*s lower compared to a formulation wherein the synthetic ester has been replaced by a lubricant base oil selected from Group I, Group II, Group III base oils or mixtures thereof [0270] 18. A lubricating composition comprising [0271] (i) at least one base oil selected from a Group I oil according to the API classification, [0272] (ii) a synthetic ester having an Iodine value lower than 10 g I/100 g measured according to DGF C-V 11 b, and [0273] (iii) optional further additives. [0274] 19. A lubricating composition comprising [0275] (i) at least one base oil selected from a Group I, Group II oil according to the API classification, or a mixture thereof [0276] (ii) a synthetic ester having an Iodine value lower than 10 g I/100 g measured according to DGF C-V 11b, [0277] (iii) optional further additives. [0278] 20. The lubricating composition according to any one of items 18 and 19, wherein the synthetic ester is a diester of a dicarboxylic acid. [0279] 21. The lubricating composition according to any one of items 18 to 20, wherein the diester of the dicarboxylic acid is selected from the group consisting of di-(isopropylheptyl)-adipate (DPHA), di-isodecyl adipate (DIDA), diisotridecyl adipate (DITA), diisononyladipate (DNA) or mixtures thereof, and preferably is di-(isopropylheptyl)-adipate (DPHA), and preferably is di(isopropylheptyl)-adipate (DPHA), diisononyladipate (DNA) or mixtures thereof. [0280] 22. A method for reducing deposit formation in a lubricating composition comprising a base oil comprising at least one Group I, Group II, or Group III base oil or mixtures thereof, comprising adding a synthetic ester having an Iodine value lower than 10 g I/100 g measured according to DGF C-V 11 b to said lubricating composition. [0281] 23. The method according to item 22, wherein the synthetic ester is added in an amount from about 5 wt.-% to about 50 wt.-%, from about 10 wt.-% to about 40 wt.-%, from about 15 wt.-% to about 35 wt.-% based on the amount of the lubricating base oil. [0282] 24. The method according to item 22 or 23, wherein the synthetic ester is added after the lubricating base oil is present in the equipment. [0283] 25. The method according to any one of items 22 to 24, wherein the synthetic ester is a diester of a dicarboxylic acid. [0284] 26. The method according to any one of items 22 to 25, wherein the diester of the dicarboxylic acid is selected from the group consisting of di-(isopropylheptyl)-adipate (DPHA), di-isodecyl adipate (DIDA), diisotridecyl adipate (DITA), diisononyladipate (DNA) or mixtures thereof, and preferably is di-(isopropylheptyl)-adipate (DPHA). [0285] 27. A lubricating composition comprising [0286] (i) at least one base oil selected from a Group I oil according to the API classification, [0287] (ii) and a diester of the dicarboxylic acid is selected from the group consisting of di(isopropylheptyl)-adipate (DPHA), di-isodecyl adipate (DIDA), diisotridecyl adipate (DITA), diisononyladipate (DNA) or mixtures thereof, wherein the diester of the dicarboxylic acid is preferably di-(isopropylheptyl)-adipate (DPHA), diisononyladipate (DNA) or mixtures thereof and more preferably is di-(isopropylheptyl)-adipate (DPHA), and [0288] (iii) optional further additives. [0289] 28. A lubricating composition comprising [0290] (i) at least one base oil selected from a Group I, Group II oil according to the API classification, or a mixture thereof [0291] (ii) and a diester of the dicarboxylic acid is selected from the group consisting of di(isopropylheptyl)-adipate (DPHA), di-isodecyl adipate (DIDA), diisotridecyl adipate (DITA), diisononyladipate (DNA) or mixtures thereof, wherein the diester of the dicarboxylic acid is preferably di-(isopropylheptyl)-adipate (DPHA), diisononyladipate (DNA) or mixtures thereof and more preferably is di-(isopropylheptyl)-adipate (DPHA), and [0292] (iii) optional further additives. [0293] 29. Use of a lubricating composition for reducing the formation of deposits, wherein the composition comprises [0294] (i) at least one lubricating base oil, and [0295] (ii) at least one synthetic ester, wherein the synthetic ester is a diester of the dicarboxylic acid is selected form the group consisting of di-(isopropylheptyl)-adipate (DPHA), diisodecyl adipate (DIDA), diisotridecyl adipate (DITA), diisononyladipate (DNA) or mixtures thereof, and preferably is di-(isopropylheptyl)-adipate (DPHA), diisononyladipate (DNA) or mixtures thereof, and more preferably is di-(isopropylheptyl)-adipate (DPHA).