LONG SERVICE LIFE TURBINE OIL WITH ZERO VARNISH DEPOSITS

Abstract

The present invention relates to turbine oil, comprising a mixture of paraffinic oils, an antioxidant and corrosion inhibitor package, polyisobutylene bisuccinimide ashless dispersant, polymethyl methacrylate pour point depressant and an organo-modified siloxane antifoam, and a method for manufacturing a turbine oil, comprising: placing a mixture of paraffinic oils in a beaker; heating the mixture of paraffinic oils to a temperature of approximately 50 C., with moderate stirring, without forming vortex that introduce air into the oil, to give homogeneity; without suspending stirring or heating, on the mixture of hot paraffinic oils, adding the antioxidant additive; without suspending stirring or heating, on the mixture of paraffinic oils adding the dispersant additive; andcontinuing stirring until a homogeneous mixture is obtained.

Claims

1. A turbine oil, comprising a mixture of paraffinic oils, an antioxidant and corrosion inhibitor package, polyisobutylene bisuccinimide ashless dispersant, polymethyl methacrylate pour point depressant, and an organo-modified siloxane antifoam.

2. The turbine oil according to claim 1, wherein the paraffinic oil mixture comprises: a paraffinic oil of group SNI of first viscosity at a specific temperature and a paraffinic oil of group SNII of first viscosity at a specific temperature; or a paraffinic oil of group SNII of first viscosity at a specific temperature and a paraffinic oil of group SNII of second viscosity at a specific temperature; or a paraffinic oil of group SNII of first viscosity at a specific temperature and a paraffinic oil of group SNII of second viscosity at a specific temperature, and a naphthenic oil of first viscosity at a specific temperature; or a paraffinic oil of group SNI of first viscosity at a specific temperature and a paraffinic oil of group SNII of first viscosity at a specific temperature; or paraffinic oil of group SNII of first viscosity at a specific temperature and paraffinic oil of group SNII of second viscosity at a specific temperature; or paraffinic oil of group SNII of first viscosity at a specific temperature, paraffinic oil of group SNI of first viscosity at a specific temperature and naphthenic oil of first viscosity at a specific temperature.

3. The turbine oil according to claim 2, wherein the paraffinic oil of group SNI of first viscosity is 22 cSt at 40 C., and the paraffinic oil of group SNII of first viscosity is 44 cSt at 40 C.

4. The turbine oil according to claim 2, wherein the paraffinic oil of group SNII of first viscosity has a viscosity of 94 cSt at 40 C., and the paraffinic oil of group SNII of second viscosity is 44 cSt at 40 C.

5. The turbine oil according to claim 2, wherein the paraffinic oil of group SNII of first viscosity is 94 cSt at 40 C., the paraffinic oil of group SNII of second viscosity is 44 cSt at 40 C., and the naphthenic oil of first viscosity is 21 cSt at 40 C.

6. The turbine oil according to claim 2, wherein the paraffinic oil of group SNII of first viscosity is 94 cSt at 40 C., the paraffinic oil of group SNI of first viscosity is 478 cSt at 40 C., and the naphthenic oil of first viscosity is 21 cSt at 40 C.

7. The turbine oil according to claim 1, wherein the mixture of paraffinic oils comprises oils of the groups SNI, SNII and SNIII, or any combination thereof.

8. The turbine oil according to claim 1, wherein the antioxidant and corrosion inhibitor package is a combination of antioxidants, corrosion inhibitors and non-ferrous metal deactivators (Additin RC 9321).

9. The turbine oil according to claim 8, wherein the antioxidant and corrosion inhibitor package refers to a combination of antioxidants, corrosion inhibitors and non-ferrous metal deactivators comprising butylated hydroxytoluene, distillates (petroleum), hydrotreated light paraffinic fraction, 1-H benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-methyl, 9-octadecenoic acid (Z)-, reaction products with 3-(dodecenyl)dihydro-2,5-furandione and triethylenetetramine, and amines, C.sub.11-14 branched alkyl monohexyl and dihexyl phosphates.

10. The turbine oil according to claim 1, wherein the polyisobutylene bisuccinimide ashless dispersant is a high nitrogen content polyisobutylene Bi-succinimide (RF114).

11. The turbine oil according to claim 1, wherein the polymethyl methacrylate pour point depressant is a polymer dissolved in highly refined neutral oil (VISCOPLEX 1-155) and/or a solution of alkyl methacrylate polymer in mineral oil (KUSAPOUR 300).

12. The turbine oil according to claim 1, wherein the organo-modified siloxane antifoam is an organo-modified siloxane (VISCOPLEX 14-520).

13. The turbine oil according to claim 1, further comprising a demulsifier which is a copolymer of ethylene oxide/propylene in ester (FUNCTIONAL DM-240).

14. A method for manufacturing a turbine oil according to claim 1, comprising: placing a mixture of paraffinic oils in a beaker; heating the mixture of paraffinic oils to a temperature of approximately 50 C., with moderate stirring, without forming vortex that introduce air into the oil, to give homogeneity; without suspending stirring or heating, on the mixture of hot paraffinic oils, adding the antioxidant and corrosion inhibitor package; without suspending stirring or heating, on the mixture of paraffinic oils, adding the polyisobutylene bisuccinimide ashless dispersant; andcontinuing stirring until a homogeneous mixture is obtained.

15. The method according to claim 14, wherein the mixture of paraffinic oils comprises oils of the groups SNI, SNII and group SNIII, or any combination thereof.

16. The method according to claim 14, wherein the antioxidant and corrosion inhibitor package is a combination of antioxidants, corrosion inhibitors and non-ferrous metal deactivators (Additin RC 9321).

17. The method according to claim 16, wherein the antioxidant and corrosion inhibitor package refers to a combination of antioxidants, corrosion inhibitors and non-ferrous metal deactivators comprising butylated hydroxytoluene, distillates (petroleum), hydrotreated light paraffinic fraction, 1-H benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-methyl, 9-octadecenoic acid (Z)-, reaction products with 3-(dodecenyl)dihydro-2,5-furandione and triethylenetetramine, and amines, C.sub.11-14 branched alkyl monohexyl and dihexyl phosphates.

18. The method according to claim 14, wherein the polyisobutylene bisuccinimide ashless dispersant is a high nitrogen content polyisobutylene Bi-succinimide (RF114).

19. The method according to claim 14, further comprising adding a polymethyl methacrylate pour point depressant, wherein the polymethyl methacrylate pour point depressant is a polymer dissolved in highly refined neutral oil (VISCOPLEX 1-155) and/or a solution of alkyl methacrylate polymer in mineral oil (KUSAPOUR 300).

20. The method according to claim 14, further comprising adding an antifoam, wherein the antifoam is an organo-modified siloxane (VISCOPLEX 14-520).

21. The method according to claim 14, further comprising adding a demulsifier, wherein the demulsifier is what is an ethylene oxide/propylene oxide ester copolymer (FUNCTIONAL DM-240).

Description

BRIEF DESCRIPTION OF THE FIGURES

[0010] To give a better understanding of the invention, a description of it is provided below, together with the accompanying figures, in which:

[0011] FIG. 1 shows a beaker with 200 ml of turbine oil and a stainless steel catalyst immersed in it.

[0012] FIG. 2 shows a beaker containing the turbine oil with the first formulation, in which a stainless steel catalyst is immersed.

[0013] FIG. 3 shows a beaker containing the turbine oil with the second formulation, in which a stainless steel catalyst is immersed.

[0014] FIG. 4 shows a beaker containing the turbine oil with the third formulation, in which a stainless steel catalyst is immersed.

[0015] FIG. 5 shows a beaker containing the turbine oil with the fourth formulation, in which a stainless steel catalyst is immersed.

[0016] FIG. 6 shows a beaker containing the turbine oil with the fifth formulation, in which a stainless steel catalyst is immersed.

[0017] FIG. 7 shows a beaker containing the turbine oil with the sixth formulation, in which a stainless steel catalyst is immersed.

[0018] FIG. 8 shows a beaker containing the turbine oil with the seventh formulation, in which a stainless steel catalyst is immersed.

[0019] FIG. 9 shows a beaker containing the turbine oil with the eighth formulation, in which a stainless steel catalyst is immersed.

[0020] FIG. 10 shows a beaker containing the turbine oil with the ninth formulation, in which a stainless steel catalyst is immersed.

[0021] FIG. 11 shows a beaker containing the turbine oil with the tenth formulation, in which a stainless steel catalyst is immersed.

[0022] FIG. 12 shows a beaker containing a first market-standard turbine oil, in which a stainless steel catalyst is immersed.

[0023] FIG. 13 shows a beaker containing a second market-standard turbine oil, in which a stainless steel catalyst is immersed.

[0024] FIG. 14 shows a filter paper with the results of the filtration of the oil of Comparative example 1.

[0025] FIG. 15 shows a filter paper with the result of the filtration of the oil of Example 1.

[0026] FIG. 16 shows a filter paper with the results of the filtration of Comparative example 2.

[0027] FIG. 17 shows a filter paper with the result of the filtration of Example 10.

DETAILED DESCRIPTION

[0028] The turbine oil of the present invention is produced from paraffinic oils of the groups SNI, SNII and SNIII, which can be produced in different mixing proportions. For mixtures with naphthenic oils, there is a limit of up to 25% by weight.

[0029] According to the first embodiment of the invention, there is a turbine oil based on a mixture of paraffinic oil of group SNI of first viscosity at a specific temperature, paraffinic oil of group SNII of first viscosity at a specific temperature, an antioxidant and corrosion inhibitor package, polyisobutylene bisuccinimide ashless dispersant, a polymethyl methacrylate pour point depressant and an organo-modified siloxane antifoam.

[0030] In the second embodiment, there is a turbine oil based on a mixture of a paraffinic oil of group SNII of first viscosity at a specific temperature, a paraffinic oil of group SNII of second viscosity at a specific temperature, an antioxidant and corrosion inhibitor package, polyisobutylene bisuccinimide ashless dispersant, a polymethyl methacrylate pour point depressant and an organo-modified siloxane antifoam.

[0031] In the third embodiment, there is a turbine oil based on a mixture of paraffinic oil of group SNII of first viscosity at a specific temperature, a paraffinic oil of group SNII of second viscosity at a specific temperature, naphthenic oil of first viscosity at a specific temperature, an antioxidant and corrosion inhibitor package, polyisobutylene bisuccinimide ashless dispersant, a polymethyl methacrylate pour point depressant, an organo-modified siloxane antifoam and a demulsifier.

[0032] In the fourth embodiment, there is a turbine oil based on a mixture of paraffinic oil of group SNII of first viscosity at a specific temperature, paraffinic oil of group SNI of first viscosity at a specific temperature, naphthenic oil of first viscosity at a specific temperature, an antioxidant and corrosion inhibitor package, polyisobutylene bisuccinimide ashless dispersant, a polymethyl methacrylate pour point depressant, an organo-modified siloxane antifoam and a demulsifier.

[0033] In the fifth embodiment, there is a turbine oil based on a mixture of paraffinic oil of group SNI of first viscosity at a specific temperature, paraffinic oil of group SNII of first viscosity at a specific temperature, an antioxidant and corrosion inhibitor package, polyisobutylene bisuccinimide ashless dispersant, polymethyl methacrylate pour point depressant and an organo-modified siloxane antifoam.

[0034] In the sixth embodiment, there is a turbine oil based on a mixture paraffinic oil of group SNII of first viscosity at a specific temperature, paraffinic oil of group SNII of second viscosity at a specific temperature, an antioxidant and corrosion inhibitor package, polyisobutylene bisuccinimide ashless dispersant, polymethyl methacrylate pour point depressant and an organo-modified siloxane antifoam.

[0035] In the seventh embodiment, there is a turbine oil based on a mixture of paraffinic oil of group SNII of first viscosity at a specific temperature, paraffinic oil of group SNII of second viscosity at a specific temperature, naphthenic oil of first viscosity at a specific temperature, an antioxidant and corrosion inhibitor package, polyisobutylene bisuccinimide ashless dispersant, a polymethyl methacrylate pour point depressant, an organo-modified siloxane antifoam and a demulsifier.

[0036] In the eighth embodiment, there is a turbine oil based on a mixture of paraffinic oil of group SNII of first viscosity at a specific temperature, paraffinic oil of group SNI of first viscosity at a specific temperature, naphthenic oil of first viscosity at a specific temperature, an antioxidant and corrosion inhibitor package, polyisobutylene bisuccinimide ashless dispersant, a polymethyl methacrylate pour point depressant, an organo-modified siloxane antifoam and a demulsifier.

[0037] In the ninth embodiment, there is a turbine oil based on a mixture of paraffinic oil of group SNI of first viscosity at a specific temperature, paraffinic oil of group SNII of first viscosity at a specific temperature, an antioxidant and corrosion inhibitor package, polyisobutylene bisuccinimide ashless dispersant, a polymethyl methacrylate pour point depressant and an organo-modified siloxane antifoam.

[0038] In the tenth embodiment, there is a turbine oil based on a mixture of paraffinic oil of group SNII of first viscosity at a specific temperature, paraffinic oil of group SNII of second viscosity at a specific temperature, an antioxidant and corrosion inhibitor package, polyisobutylene bisuccinimide ashless dispersant, a polymethyl methacrylate pour point depressant and an organo-modified siloxane antifoam.

[0039] Within the scope of the invention, the antioxidant and corrosion inhibitor package refers to a combination of antioxidants, corrosion inhibitors and non-ferrous metal deactivators, specifically, butylated hydroxytoluene, Distillates (petroleum), hydrotreated light paraffinic, 1-H benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-methyl, 9-octadecenoic acid (Z)-, reaction products with 3-(dodecenyl)dihydro-2,5-furandione and triethylenetetramine, and amines, C.sub.11-14 branched alkyl monohexyl and dihexyl phosphates (Additin RC 9321).

[0040] Polyisobutylene bisuccinimide ashless dispersant is a high nitrogen content polyisobutylene bisuccinimide (RF114).

[0041] Polymethyl methacrylate pour point depressant is a polymer dissolved in highly refined neutral oil (VISCOPLEX 1-155) and/or a solution of alkyl methacrylate polymer in mineral oil (KUSAPOUR 300).

[0042] The antifoam is an organo-modified siloxane (VISCOPLEX 14-520).

[0043] The demulsifier is an ethylene oxide/propylene ester copolymer (FUNCTIONAL DM-240).

[0044] According to another embodiment of the invention, there is a method for turbine oil comprising the following steps: [0045] 1. Place the basic oils in a beaker. [0046] 2. Heath the base oils to a temperature of approximately 50 C., with moderate agitation, without forming vortex that introduce air into the oil, seeking homogeneity. [0047] 3. Without stopping stirring or heating, add the antioxidant and corrosion inhibitor package to the previous mixture. [0048] 4. Without stopping stirring or heating, add all the additives to the previous mixture. [0049] 5. Continue stirring until a homogeneous mixture is obtained.

EXAMPLES

[0050] Below are examples of turbine oils according to the described embodiments, which have been grouped as follows: [0051] Turbine oil type I: examples 1, 2, 3 and 4 [0052] Turbine oil type II: examples 5, 6, 7 and 8 [0053] Turbine oil type III: examples 9 and 10

Example 1

[0054] The product was prepared with the following base stock mixture: 43.085% by weight of paraffinic oil of group SNI with a viscosity of 22 cSt at 40 C., and 56.305% by weight of paraffinic oil of group SNII with a viscosity of 44 cSt at 40 C., antioxidant and corrosion inhibitor package at 0.32% by weight, polyisobutylene bisuccinimide ashless dispersant at 0.04% by weight, polymethyl methacrylate pour point depressant at 0.20% by weight, and organo-modified siloxane antifoam at 0.05% by weight.

Example 2

[0055] The product was prepared with the following base stock mixture: 5.055% by weight of paraffinic oil of group SNII with a viscosity of 94 cSt at 40 C., and 94.335% by weight of paraffinic oil of group SNII with a viscosity of 44 cSt at 40 C., antioxidant and corrosion inhibitor package at 0.32% by weight, polyisobutylene bisuccinimide ashless dispersant at 0.04% by weight, polymethyl methacrylate pour point depressant at 0.20% by weight, and organo-modified siloxane antifoam at 0.05% by weight.

Example 3

[0056] The product was prepared with the following base stock mixture: 62.533% by weight of paraffinic oil of group SNII with a viscosity of 94 cSt at 40 C., 27.712% by weight of paraffinic oil of group SNII with a viscosity of 44 cSt at 40 C., 8.995% by weight of naphthenic oil with a viscosity of 21 cSt at 40 C., antioxidant and corrosion inhibitor package at 0.32% by weight, polyisobutylene bisuccinimide ashless dispersant at 0.04% by weight, polymethyl methacrylate pour point depressant at 0.20% by weight, organo-modified siloxane antifoam at 0.05% by weight, and demulsifier at 0.15% by weight.

Example 4

[0057] The product was prepared with the following base stock mixture: 57.588% by weight of paraffinic oil of group SNII with a viscosity of 94 cSt at 40 C., 21.844% by weight of paraffinic oil of group SNI with a viscosity of 478 cSt at 40 C., 19.858% by weight of naphthenic oil with a viscosity of 21 cSt at 40 C., antioxidant and corrosion inhibitor package at 0.32% by weight, polyisobutylene bisuccinimide ashless dispersant at 0.04% by weight, polymethyl methacrylate pour point depressant at 0.20% by weight, organo-modified siloxane antifoam at 0.05% by weight, and demulsifier at 0.1% by weight.

Example 5

[0058] The product was prepared with the following base stock mixture: 42.910% by weight of paraffinic oil of group SNI with a viscosity of 22 cSt at 40 C., 56.277% by weight of paraffinic oil of group SNII with a viscosity of 44 cSt at 40 C., antioxidant and corrosion inhibitor package at 0.50% by weight, polyisobutylene bisuccinimide ashless dispersant at 0.63% by weight, polymethyl methacrylate pour point depressant at 0.20% by weight, and organo-modified siloxane antifoam at 0.05% by weight.

Example 6

[0059] The product was prepared with the following base stock mixture: 5.235% by weight of paraffinic oil of group SNII with a viscosity of 94 cSt at 40 C., 93.952% by weight of paraffinic oil of group SNII with a viscosity of 44 cSt at 40 C., antioxidant and corrosion inhibitor package at 0.50% by weight, polyisobutylene bisuccinimide ashless dispersant at 0.63% by weight, polymethyl methacrylate pour point depressant at 0.20% by weight, and organo-modified siloxane antifoam at 0.05% by weight.

Example 7

[0060] The product was prepared with the following base stock mixture: 62.442% by weight of paraffinic oil of group SNII with a viscosity of 94 cSt at 40 C., 27.627% by weight of paraffinic oil of group SNII with a viscosity of 44 cSt at 40 C., 8.968% by weight of naphthenic oil with a viscosity of 21 cSt at 40 C., antioxidant and corrosion inhibitor package at 0.50% by weight, polyisobutylene bisuccinimide ashless dispersant at 0.63% by weight, polymethyl methacrylate pour point depressant at 0.20% by weight, organo-modified siloxane antifoam at 0.05% by weight, and demulsifier at 0.15% by weight.

Example 8

[0061] The product was prepared with the following base stock mixture: 57.512% by weight of paraffinic oil of group SNII with a viscosity of 94 cSt at 40 C., 21.777% by weight of paraffinic oil of group SNI with a viscosity of 478 cSt at 40 C., 19.797% by weight of naphthenic oil with a viscosity of 21 cSt at 40 C., antioxidant and corrosion inhibitor package at 0.50% by weight, polyisobutylene bisuccinimide ashless dispersant at 0.63% by weight, polymethyl methacrylate pour point depressant at 0.20% by weight, organo-modified siloxane antifoam at 0.05% by weight, and demulsifier at 0.1% by weight.

Example 9

[0062] The product was prepared with the following base stock mixture: 42.908% by weight of paraffinic oil of group SNI with a viscosity of 22 cSt at 40 C., 55.942% by weight of paraffinic oil of group SNII with a viscosity of 44 cSt at 40 C., antioxidant and corrosion inhibitor package at 0.80% by weight, polyisobutylene bisuccinimide ashless dispersant at 0.10% by weight, polymethyl methacrylate pour point depressant at 0.20% by weight, and organo-modified siloxane antifoam at 0.05% by weight.

Example 10

[0063] The product was prepared with the following base stock mixture: 5.122% by weight of paraffinic oil of group SNII with a viscosity of 94 cSt at 40 C., 93.728% by weight of paraffinic oil of group SNII with a viscosity of 44 cSt at 40 C., antioxidant and corrosion inhibitor package at 0.80% by weight, polyisobutylene bisuccinimide ashless dispersant at 0.10% by weight, polymethyl methacrylate pour point depressant at 0.20% by weight, and organo-modified siloxane antifoam at 0.05% by weight.

[0064] The results of critical tests for the present invention are exhibited in the following Tables 1 to 3:

TABLE-US-00001 TABLE 1 Oil for type I turbines. PROPERTIES ASTM METHOD Example 1 Example 2 Example 3 Example 4 Acid number, mg KOH/g ASTM D974 0.04 0.04 0.05 0.06 Copper corrosion ASTM D130 1b 1b 1b 1b 100 C./3 h Demulsification ASTM 42-38-0 40-40-0 41-37-2 40-40-0 test, ml-ml-ml D1401 (20) (30) (25) (10) (min) Foaming ASTM D892 T/0 10/0 10/0 10/0 tendency, 1 st sec., ml/ml Oxidation ASTM 1154 1050 855 567 stability D2272 RPVOT, min

TABLE-US-00002 TABLE 2 Oil for type II turbines. PROPERTIES ASTM METHOD Example 5 Example 6 Example 7 Example 8 Acid number, mg KOH/g ASTM D974 0.05 0.04 0.07 0.06 Copper corrosion ASTM D130 1b 1b 1b 1b 100 C./3 h Demulsification ASTM D1401 40-40-0 40-40-0 42-38-0 40-40-0 test, ml-ml-ml (20) (10) (10) (10) (min) Foaming ASTM D892 T/0 10/0 10/0 10/0 tendency, 1 st sec., ml/ml Oxidation ASTM D2272 1470 1427 1319 797 stability RPVOT, min

TABLE-US-00003 TABLE 3 Oil for type III turbines. PROPERTIES ASTM METHOD Example 9 Example 10 Acid number, mg KOH/g ASTM D974 0.11 0.11 Copper corrosion 100 C./3 h ASTM D130 1b 1b Demulsification test, ml-ml-ml (min) ASTM D1401 40-40-0 (20) 40-40-0 (10) Foaming tendency, 1 st sec., ml/ml ASTM D892 T/0 T/0 Oxidation stability RPVOT, min ASTM D2272 1742 1972

[0065] To evaluate the varnish deposit potential of turbine oils, tests were performed as follows: [0066] The different oils from examples 1 to 10 are received in beakers, with 200 ml of sample, with a stainless steel catalyst at the bottom of the beaker, see FIG. 1. [0067] The samples were then placed in an oven at 162 C. for 36 hours. [0068] After this period of time, they are left to rest at room temperature for 72 hours. The oil is available for filtering with 2.5 m membranes.

[0069] Thus, FIGS. 2 to 11 show the turbine oils of Examples 1 to 10, respectively, and at the bottom of each beaker is the stainless steel catalyst.

Comparative Analysis with Turbine Oils

[0070] For the comparative analysis, two market benchmark turbine oils were selected to carry out the performance tests described above.

TABLE-US-00004 TABLE 4 Turbine oils on the market. Comparative Comparative PROPERTIES ASTM METHOD example 1 example 2 Acid number, mg KOH/g ASTM D974 0.17 0.11 Copper corrosion 100 C./ ASTM D130 1b 1b 3 h Demulsification test, ASTM D1401 40-40-0 ml-ml-ml (min) (20) 40-40-0 (15) Foaming tendency, 1 st ASTM D892 T/0 T/0 sec., ml/ml Oxidation stability ASTM D2272 641 1971 RPVOT, min

[0071] The oils of Comparative examples 1 and 2 oils, namely Mobile DTE oil light and Krasne Plus AW ISO 32 (ROSHFRANS) oil respectively, were evaluated for varnish deposit potential on an equal basis with Examples 1 to 10. The results are shown in FIGS. 12 and 13. The oils tested above show a high level of varnish deposits.

[0072] Finally, the results of the filtration of the Comparative analysis 1 and 2 oils are presented after the evaluation of the varnish deposit potential, and of the oils of Examples 1 and 10.

[0073] FIGS. 14 and 16 show the filtration residues of the oils of Comparative analyses 1 and 2, respectively.

[0074] FIGS. 15 and 17 show the filtration residues of the oils of Examples 1 and 10, respectively.

CONCLUSIONS

[0075] In view of the results shown above, its excellent results in preventing the formation of varnish deposits in the test subjects can be observed. The present invention allows the formulation of oils for turbine types I, II and III, with characteristics of zero generation of varnish deposits and long service life, without affecting any other performance characteristics, such as oxidation stability, demulsification, foaming tendency, and copper corrosion. In addition, the service life of filters and oil cleaning components is increased.

[0076] Therefore, the oil thickening, varnish deposits formation on metal surfaces and corrosive wear are prevented.

[0077] The present invention has been described in its preferred embodiment; however, it will be apparent to those skilled in the art that a multitude of changes and modifications can be made to this invention without departing from the scope of the following claims.