ETHER COMPOUNDS AND RELATED COMPOSITIONS

Abstract

In some embodiments, a compound has the formula (I) where: R.sub.1 and R.sub.2 are alkyl or, together with the carbon atom to which they are attached, cycloalkyl; R.sub.3, R.sub.4 and R.sub.5 are H or alkyl (formula II); R.sub.6 is alkyl or where: R.sub.7 and R.sub.8 are H, alkyl or, together with the carbon atom to which they are attached, cycloalkyl; R.sub.9 is H or alkyl; X is alkylene or is absent; and p is 0, 1, 2 or 3; and m and n are 0, 1, 2 or 3 provided that m is 0 when R.sub.4 and R.sub.5 are H. The compound is suitable for use as a base stock which provides low volatility for a given viscosity profile. The compound may be used in a lubricant composition for an internal combustion engine.

##STR00001##

Claims

1-33. (canceled)

34. A compound of formula (2): ##STR00068## where: R.sub.1 and R.sub.2 are alkyl or, together with the carbon atom to which they are attached, cycloalkyl; R.sub.3 and R.sub.5 are H or alkyl; R.sub.4 is alkyl; R.sub.6 is alkyl; and n is 0, 1, 2 or 3, wherein the compound contains a total number of carbon atoms of from 20 to 50.

35. The compound of claim 34, wherein the compound has the formula (3): ##STR00069## where: R.sub.1 is alkyl; R.sub.3 and R.sub.5 are H or alkyl; R.sub.4 is alkyl; R.sub.6 is alkyl; and n is 0, 1, 2 or 3.

36. The compound of claim 35, wherein the compound has the formula (4): ##STR00070## where: R.sub.1 and R.sub.4 are C.sub.1-15 alkyl; R.sub.3 and R.sub.5 are H or C.sub.1-15 alkyl.

37. The compound of claim 36, wherein: R.sub.1 is C.sub.4-12 alkyl; R.sub.3 is H; R.sub.4 is C.sub.1-10 alkyl; and R.sub.5 is H.

38. The compound of claim 34, wherein the compound has the formula (10): ##STR00071## where: R.sub.1 and R.sub.4 are alkyl; R.sub.3 and R.sub.5 are H or alkyl; R.sub.6 is alkyl.

39. The compound of claim 34, wherein R.sub.1 and R.sub.2 are C.sub.1-15 alkyl or, together with the carbon atom to which they are attached, C.sub.5-30 cycloalkyl; R.sub.3 and R.sub.5 are H or C.sub.1-15 alkyl; R.sub.4 is C.sub.1-15 alkyl; R.sub.6 is C.sub.1-15 alkyl; and n is 0, 1, or 2.

40. The compound of claim 34, wherein R.sub.1 and R.sub.2 are C.sub.2-12 alkyl or, together with the carbon atom to which they are attached, C.sub.5-25 cycloalkyl; R.sub.3 and R.sub.5 are H or C.sub.2-12 alkyl; R.sub.4 is C.sub.2-12 alkyl; R.sub.6 is C.sub.2-12 alkyl; and n is 0, 1, or 2.

41. The compound of claim 34, wherein R.sub.1 and R.sub.2 are C.sub.2-12 alkyl or, together with the carbon atom to which they are attached, C.sub.5-25 cycloalkyl; R.sub.3 is H or C.sub.2-12 alkyl; R.sub.4 is C.sub.2-12 alkyl; R.sub.5 is H; R.sub.6 is C.sub.2-12 alkyl; and n is 0 or 1.

42. The compound of claim 36, wherein: R.sub.1 is C.sub.6-10 alkyl; R.sub.3 is H; R.sub.4 is C.sub.2-8 alkyl; and R.sub.5 is H.

43. The compound of claim 34, wherein the compound is prepared from bio-derived feedstock.

44. The compound of claim 34, wherein the compound contains greater than 50% by weight of biobased carbon.

45. The compound of claim 34, wherein the compound has at least one of: a kinematic viscosity at 40 C. of less than 25 cSt; a kinematic viscosity at 100 C. of less than 7 cSt; a viscosity index of greater than 100; a viscosity at 150 C. and a shear rate of 10.sup.6 s.sup.1 of no greater than 1.7 cP; a Noack volatility of less than 26% by weight; and a pour point of less than 10 C.

46. The compound of claim 34, wherein the compound has a kinematic viscosity at 100 C. of 3 to 4 cSt and a Noack volatility of less than 20% by weight; or a kinematic viscosity at 100 C. of 2 to 3 cSt, and a Noack volatility of less than 40% by weight.

47. A base oil comprising a compound as defined in claim 34.

48. The base oil of claim 47, wherein the base oil comprises greater than 10% by weight of the compound.

49. The base oil of claim 47, wherein the base oil comprises a base stock selected from Group I, Group II, Group III, Group IV and Group V base stocks and mixtures thereof.

50. A lubricant composition comprising a base oil as defined in claim 47.

51. The lubricant composition of claim 47, wherein the lubricant composition comprises greater than 50% by weight of the base oil.

52. The lubricant composition of claim 47, wherein the lubricant composition has at least one of: a kinematic viscosity at 40 C. of less than 60 cSt; a kinematic viscosity at 100 C. of less than 12 cSt; a viscosity index of greater than 100; a viscosity at 150 C. and a shear rate of 10.sup.6 s.sup.1 of no greater than 3 cP; and a Noack volatility of less than 25% by weight.

53. A method of preparing a base oil, said method comprising providing a compound as defined in claim 34, and preparing a base oil comprising said compound.

54. A method of preparing a lubricant composition, said method comprising providing a base oil as defined in claim 47, and blending the base oil with one or more lubricant additives to prepare the lubricant composition.

55. A method of improving the oxidative stability performance, fuel economy performance, and/or piston cleanliness performance of a lubricating composition, comprising the step of providing to the lubricating composition a compound according to claim 34.

56. A method of improving the oxidative stability performance, fuel economy performance, and/or piston cleanliness performance of a lubricating composition, comprising the step of providing to the lubricating composition a base oil according claim 47.

57. A method of lubricating a surface, said method comprising supplying a lubricant composition as defined in claim 50 to said surface.

Description

[0286] The invention will now be described with reference to the accompanying figures and examples, which are not limiting in nature, in which:

[0287] FIG. 1 is a graph of volatility against pour point for compounds of formula (1), other ether base stocks and conventional base stocks;

[0288] FIG. 2 is a graph of volatility against kinematic viscosity at 100 C. for compounds of formula (1), other ether base stocks and conventional base stocks;

[0289] FIG. 3 is a graph of volatility against cold-cranking simulator performance for compounds of formula (1) and conventional base stocks;

[0290] FIG. 4a is a graph of kinematic viscosity at 40 C. against time of lubricant compositions containing compounds of formula (1), a conventional hydrocarbon base stock and a farnesene-derived ether base stock during a TU-5 JP engine test;

[0291] FIG. 4b is a graph of absolute change in kinematic viscosity at 40 C. of lubricant compositions containing compounds of formula (1), a conventional hydrocarbon base stock and a farnesene-derived ether base stock during a TU-5 JP engine test; and

[0292] FIG. 5 is a graph of overall piston merit performance of lubricant compositions containing compounds of formula (1) and a conventional hydrocarbon base stock during a TU-5 JP engine test.

EXAMPLES

Example 1Properties of Ether Base Stocks

[0293] Guerbet-derived base stocks GE1-GE3, GE5 and GE7-GE9, secondary ether base stocks SE1 and SE2, and tertiary ether base stock TE1 of formula (1) were prepared. Two further Guerbet-derived base stocks, GE4 and GE6, and an experimental group V base stock of the type previously described in WO 2014/207235, i.e. a farnesene-derived ether base stock, were also prepared. The structure of these compounds is shown in Table 3.

TABLE-US-00003 TABLE 3 Molec- ular Chemical Weight Formula Structure GE1 466.87 C.sub.32H.sub.66O [00045] GE2 466.87 C.sub.32H.sub.66O [00046] GE3 522.97 C.sub.36H.sub.74O [00047] GE4 466.87 C.sub.32H.sub.66O [00048] GE5 410.76 C.sub.28H.sub.58O [00049] GE6 466.87 C.sub.32H.sub.66O [00050] GE7 522.57 C.sub.36H.sub.74O [00051] GE8 382.42 C.sub.26H.sub.54O [00052] GE9 466.51 C.sub.32H.sub.66O [00053] GE10 410.76 C.sub.28H.sub.58O [00054] GE12 382.71 C.sub.26H.sub.54O [00055] GE14 410.76 C.sub.28H.sub.58O [00056] GE15 354.65 C.sub.24H.sub.50O [00057] GE16 424.79 C.sub.29H.sub.60O [00058] GE18 438.81 C.sub.30H.sub.62O [00059] GE20 354.65 C.sub.24H.sub.50O [00060] GE21 382.71 C.sub.26H.sub.54O [00061] GE22 410.76 C.sub.28H.sub.58O [00062] GE23 382.71 C.sub.26H.sub.54O [00063] SE1 452.84 C.sub.31H.sub.64O [00064] SE2 396.43 C.sub.27H.sub.56O [00065] TE1 466.87 C.sub.32H.sub.66O [00066] Farnesene- derived ether 396.73 C.sub.27H.sub.56O [00067]

[0294] The following properties of the base stocks were tested:

[0295] Kinematic viscosity at 100 C. (KV100) and kinematic viscosity at 40 C. (KV40) were tested according to ASTM D7279.

[0296] Viscosity index (VI) was calculated according to ASTM D2270.

[0297] Pour point was determined according to ASTM D7346.

[0298] Differential scanning calorimetry (DSC) oxidation onset temperature was tested using a method which was based on ASTM E2009 (method B). According to the method, the base stocks were heated from 50 C. to 300 C., at a rate of 50 C./minute, under a pressure of 500 psi in an aluminium SFI pan. The temperature at which an exotherm was observed was recorded.

[0299] Noack volatility was measured using a method which was based on IP 393 and was considered similar to CEC-L-40-A-93. According to the method, reference oils of known Noack volatility were heated from 40 C. to 550 C. to determine the temperature at which the Noack volatility weight loss of each of the reference oils was reached. The base stocks were subjected to the same process as the reference oils. The Noack weight of the base stocks could be determined based on the results obtained from the reference oils.

[0300] The results of the tests are summarized in Table 4, together with results obtained from conventional base stocks (Durasyn 162, a group IV base stock; Durasyn 164, a group IV base stock; Yubase 3, a group II base stock; Yubase 4, a group III base stock; Yubase 4 Plus, a group III base stock; Nexbase 3020, a group II base stock; Nexbase 3030, a group II base stock; Nexbase 3043, a group III base stock; and Chevron 100RLV, a group II base stock). Results obtained from the farnesene-derived ether base stock are also shown for reference.

TABLE-US-00004 TABLE 4 KV100 KV40 Pour Point DSC Oxidation Noack (cSt) (cSt) VI ( C.) Onset T ( C.) (% by weight) GE1 3.3 13.0 125 42 201.26 5.9 GE2 3.5 13.7 145 36 205.74 5.1 GE3 3.9 16.0 143 42 202.89 2.4 GE4 3.3 11.9 146 27 213.37 3.9 GE5 2.5 8.2 136 60 203.87 17.9 GE6 3.8 14.6 166 12 212.71 2.0 GE7 4.0 16.5 144 36 206.26 6.8 GE8 2.3 7.7 111 66 213.95 44.9 GE9 3.8 14.9 160 15 208.17 2.5 SE1 2.7 9.6 123 18 195.37 12.9 SE2 2.5 9.0 101 45 183.21 51.8 TE1 3.6 14.9 133 212.91 6.8 Durasyn 162 1.7 5.2 92 72 223.61 99.6 Durasyn 164 4.0 17.8 126 75 221.31 18.8 Yubase 3 3.0 14.1 105 36 220.74 38.6 Yubase 4 4.2 19.2 126 12 220.00 11.7 Yubase 4 Plus 4.2 18.4 138 18 220.32 11.6 Nexbase 3020 2.2 7.6 93 51 221.66 81.9 Nexbase 3030 3.0 12.0 101 39 221.05 36.8 Nexbase 3043 4.3 19.9 124 18 222.09 13.2 Chevron 4.6 22.6 119 15 225.86 13.2 110RLV Farnesene- 3.2 11.6 152 36 222.26 14.1 derived ether

[0301] A graph of volatility against pour point for ether base stocks GE1-GE9, SE1, SE2 and TE1 and the conventional base stocks is shown in FIG. 1. It can be seen that the Guerbet-derived base stock ethers have a low volatility for a given pour point compared to conventional base oils. Moreover, the Guerbet-derived base stocks in which both sides of the ether are branched exhibit unexpected improvements in pour point as compared to Guerbet-derived base stocks of comparable carbon number in which only one side of the ether is branched, without any significant loss of volatility.

[0302] A graph of volatility against kinematic viscosity at 100 C. for ether base stocks GE1-GE9, SE1, SE2 and TE1 and the conventional base stocks is shown in FIG. 2. It can be seen that the Guerbet-derived base stocks and the secondary and tertiary ether base stocks exhibit both low volatility and low viscosity as compared to conventional base oils.

[0303] Cold-cranking simulator (CCS) analysis of Guerbet-derived base stocks GE2 and GE3 was also carried out according to ASTM D5293. A graph of volatility against cold-cranking simulator viscosity is shown in FIG. 3. For comparison, data obtained from conventional hydrocarbon base stocks having a KV100 of from 2.6 to 4.2 is also shown. It can be seen that the Guerbet-derived ethers exhibit excellent CCS viscosity, as well as low volatility.

Example 2: Properties of Lubricant Compositions Containing Ether Base Stocks

[0304] Guerbet-derived ether base stocks GE2 and GE3 were blended with conventional base oil additives (additive A, a commercially available additive package; additive B, a cold-flow improver; additive C, an oxidation inhibitor; and additive D, a viscosity index improver) and conventional base oils (Yubase 4, a group III base oil; and Yubase 6, a group III base oil) to form lubricant blends. A Baseline blend and a farnesene-derived ether blend were also prepared. Yubase 4 was chosen as the main component of the Baseline blend, since it exhibits a similar KV100 to Guerbet-derived ether base stock, GE3. The Baseline blend was believed to be a stringent baseline for comparison, since it is a 5W-30 formulation which meets certain specifications (ACEA A5/B5, API-SN/GF-4). The details of the blended compositions are shown in Table 5 in % by weight.

TABLE-US-00005 TABLE 5 Baseline GE2 GE3 Farnesene- blend blend blend derived blend Additive A 16.4 16.4 16.4 16.4 Additive B 0.15 0.15 0.15 0.15 Additive C 0.1 0.1 0.1 0.1 Additive D 4 4 4 4 Yubase 4 67.45 30.47 17.45 17.45 Yubase 6 11.9 11.9 11.9 11.9 GE2 0 36.98 0 0 GE3 0 0 50 0 Farnesene-derived ether 0 0 0 50

[0305] No problems with miscibility were encountered during preparation of the blended compositions.

[0306] The blended compositions were tested to see whether the advantageous properties of the base stocks would be reflected in a fully formulated lubricant composition. The following properties were tested:

[0307] Kinematic viscosity at 100 C. (KV100) and kinematic viscosity at 40 C. (KV40) were tested according to ASTM D445 (part of SAE J300).

[0308] Viscosity index (VI) was calculated according to ASTM D2270.

[0309] Cold-cranking simulator (CCS) analysis was carried out at 30 C. according to ASTM D5293 (part of SAE J300).

[0310] High temperature high shear (HTHS) analysis was carried out according to CEC-L-36-A-90.

[0311] Total base number (TBN) was determined according to ASTM D2896.

[0312] Noack volatility was tested according to CEC-L-40-A-93.

[0313] Sulphated ash content was measured according to IP 163.

[0314] The results of the tests are summarized in Table 6.

TABLE-US-00006 TABLE 6 Baseline GE2 GE3 Farnesene- blend blend blend derived blend KV40 (cSt) 53.59 48.26 44.63 38.57 KV100 (cSt) 9.542 9.105 8.688 7.877 VI 164 173 177 181 CCS 30 C. (cP) 4656 2608 2702 2010 HTHS (cP) 2.98 2.85 2.75 2.62 TBN (mg KOH/g) 11.66 11.29 11.44 10.88 NOACK (% by weight) 11.2 7.7 9.7 14.9 Sulphated ash (%) 1.22 1.26 1.27 1.20

[0315] It can be seen that the properties of the Guerbet-derived base stocks are also exhibited in the blended compositions. In particular, beneficial viscosity, volatility and cold-flow properties are observed. The Guerbet-derived base stocks also exhibited similar HTHS measurements, TBNs and sulphated ash contents to the Baseline blend.

Example 3: Engine Performance of Lubricant Compositions Containing Ether Base Stocks

[0316] The blended compositions from Example 2 were subjected to a TU-5 JP engine test run according to CEC-L-88-02 (part of ACEA A, B and C sequences) in order to determine the oxidative stability of the compositions by assessment of viscosity increases, as well as piston cleanliness and piston ring sticking. The temperature in the oil gallery was controlled to 150 C. for the duration of the test. The results of the TU-5 JP engine tests for the Baseline, GE2 and GE3 lubricant compositions are shown in Table 7.

[0317] The blended compositions from Example 2 were also subjected to MRV testing at 35 C. according to ASTM D4684 in order to gauge low-temperature viscosity characteristics of the compositions before and after use in the TU-5 JP engine test. The results of the MRV testing are also shown in Table 7.

TABLE-US-00007 TABLE 7 Baseline GE2 GE3 Limits Absolute viscosity increase 47.3 27 13.1 57.3 at 40 C. (mm.sup.2/s) Viscosity at 40 C. 53.8 45.1 48.2 None 0 hours (mm.sup.2/s) Viscosity at 40 C. 101.1 72.1 61.3 None 72 hours (mm.sup.2/s) Overall piston merit (x/10) 8.2 9.2 9.0 7.6 (5 elements, CRC rating) Ring sticking merit 1st ring 10 10 10 9 (worst) MRV pre-TU-5 (cP) 21500 7200 7500 Yield stress pre-TU-5 (Pa) <35 <35 <35 MRV post-TU-5 (cP) 56500 11700 18000 Yield stress post-TU-5 (Pa) <35 <35 <35

[0318] The lubricant compositions containing Guerbet-derived base stocks passed all aspects of the TU-5 JP engine test.

[0319] A graph of kinematic viscosity at 40 C. against time is shown in FIG. 4a, and a graph showing the absolute change in kinematic viscosity at 40 C. after 60 hours is shown in FIG. 4b. For comparison, results obtained from the Farnesene-derived blend from Example 2 are also shown. It can be seen that the increase in viscosity of the lubricant compositions containing Guerbet-derived base stocks or the Farnesene-derived blend were significantly lower than or similar to that of the Baseline composition, with the results obtained from the Guerbet-derived ether being particularly good. The results indicate that the lubricant compositions containing ether base stocks exhibit superior oxidative stability.

[0320] A graph showing the overall piston merit is shown in FIG. 5. It can be seen that the lubricant compositions containing Guerbet-derived base stocks had overall high piston merits score, indicating that these blends exhibit good piston cleanliness performance.

[0321] The MRV results further demonstrate the excellent low-temperature viscosity characteristics of lubricant compositions containing Guerbet-derived base stocks before and after their use.

Example 4: Engine Compatibility of Lubricant Compositions Containing Ether Base Stocks

[0322] The blended formulation of GE3 from Example 2 was subjected to Mercedes EAM and ACEA RE2 seal tests (test methods VDA 675301 and CEC-L-39-96, respectively) to determine the compatibility of the ether base stocks with typical seals that are found in engines. An ethylene acrylic rubber is used in the EAM test, whilst an acrylic-based rubber is used in the RE2 test. The results of the Mercedes EAM and ACEA RE2 seal tests are shown in Table 8.

TABLE-US-00008 TABLE 8 Baseline GE3 Pass Limits AEM Seal Tensile strength 9.5 3.4 > 35 Test (Mpa % variation) Elongation Rupture 18.6 26.9 > 50 (% variation) Hardness 3 5 10 to 5 (Variation, points) Relative volume change 2.5 0.3 15 to 5 (%) ACEA Tensile Strength 2 2 18 to 15 RE2 (% variation) Elongation Rupture 32 35 10 to 35 (% variation) Hardness 7 3 8 to 5 (Variation, points) Relative volume change 0.6 0.6 5 to 7 (%)

[0323] It can be seen that the lubricant composition containing a Guerbet-derived base stock passed both of the seal tests, indicating that the ether base stocks are suitable for use in engines.

Example 5: Engine Fuel Consumption Performance of Lubricant Compositions Containing Ether Base-Stocks

[0324] Another blended formulation of GE3 and the baseline blend were subjected to an M111 fuel economy test according to CEC-L-054-96 (part of the ACEA A and B sequences) in order to determine the fuel consumption performance of engines run on ether base-stocks. The results are given below in table 9 and are quoted as percentage improvement over the RL191 15W-40 baseline oil commonly used for such assessments. Accordingly, the results reported as Baseline below recite the percentage performance of the Baseline blend (5W-30 formulation mentioned above) over the RL 191 15W-40 standard.

TABLE-US-00009 TABLE 9 Baseline GE3 Pass Limits Fuel Economy 2.89% 3.19% >2.5% Improvement relative to RL191 15W-40

[0325] It can be seen that the lubricant containing a Guerbet-derived base stock passed the fuel economy test and showed an improvement over the baseline lubricant composition, indicating that the ether base stocks offer a fuel economy benefit.