JP4674342B2 - Lubricating oil composition - Google Patents

Description

  The present invention is directed to a lubricating oil composition comprising a Fischer-Tropsch derived base oil and one or more additives. The present invention is particularly directed to so-called SAE J300 class lubricating oil compositions.

  This type of lubricating oil composition is also referred to as a SAE xW-y composition. SAE stands for US Society of Automotive Engineers. In such a representation, the “x” number is usually associated with the maximum viscosity requirement at low temperature for the lubricating oil composition as measured under high shear by a low temperature crank rotation simulator (VdCCS). The second number “y” is related to the kinematic viscosity requirement at 100 ° C. as follows.

  Lubricating oil compositions comprising a Fischer-Tropsch derived base oil and one or more additives are described, for example, in WO-A-0157166. According to this publication, the lubricating oil may contain a so-called viscosity modifier polymer. Such additives are usually relatively high molecular weight components that exhibit significant thickening when blended with other components and base oils. Such high molecular weight materials are generally polymeric materials also known as viscosity modifier polymers, polymeric thickeners or viscosity index improvers.

WO-A-0157166 discloses a lubricating oil formulation that does not contain a viscosity modifier polymer. In particular, lubricating oil formulations that do not contain a viscosity modifier polymer are SAE “xW-y” (where x = 0, 5, 10, or 15, = 10, 20, 30 or 40, (y−x) is May be consistent with the viscosity rating (which is 25 or less).
According to the publication, in many cases, viscosity modifier polymers in combination with low viscosity basestocks are very advantageous in achieving the desired viscosity method targets, especially with multi-grade lubricants. It states that something has been found. In addition, a wide range of cross-grade lubricant formulations, such as 0W-40, 5W-50 and 10W-60 oils, can be used with narrower cross-grade lubricant formulations, such as 0W-20 and 10W-30 oils. More high molecular weight polymer thickeners are required (less or no high molecular weight polymer thickeners are required).

  Examples 11-14 of WO-A-0157166 include a non-viscosity lubricating oil formulation according to SAE 0W-20, SAE 5W-20 and SAE 10W-30 wherein a poly-α-olefin and a Fischer-Tropsch derived base oil It is shown that it can be obtained by blending. The Fischer-Tropsch derived base oil has a kinematic viscosity at 100 ° C. of 3.7, 4.0, 4.1, and 6.0 cSt, respectively. According to this specification, lubricating oil formulations without viscosity modifiers have been obtained only with formulations that also contain poly-α-olefins.

Applicants have found that when a lubricant consisting of a viscosity modifier as described above is used as an automotive engine lubricant for a gasoline direct injection engine (GDI), residue tends to accumulate behind the inlet valve edge. . These residues are very disadvantageous because they tend to harden and detach from the surface and can enter the cylinder of an automobile engine and damage the engine.
WO-A-0157166 EP-A-776959 EP-A-668342 WO-A-9721788 WO-0015736 WO-0014188 WO-0014187 WO-0014183 WO-0014179 or WO-A-0014179 WO-0008115 WO-9941332 EP-1029029 WO-0118156 WO-0157166 WO-A-9934917 AU-A-698392 EP-A-532118 EP-A-666894 US-A-4859311 WO-A-9718278 US-A-5053373 US-A-5252527 US-A-45744033 US-A-5157191 WO-A-0029511 EP-A-832171 Lubricant Base Oil and Wax Processing, Abilino Sequeia, Jr., Marcel Decker Inc. , New York, 1994, Chapter 7 Micropores and mesopores materials, Vol. 22 (1998), pp. 644-645 “Verified synthesis of zeolitic materials”

  It is an object of the present invention to provide a lubricating oil formulation that does not cause residue accumulation when used in a GDI engine.

  This object is achieved by the following lubricating oil composition. One Fischer-Tropsch derived base oil is a low viscosity component having a kinematic viscosity at 100 ° C. of less than 7 cSt, and the other Fischer-Tropsch derived base oil is a high viscosity component having a kinematic viscosity at 100 ° C. of more than 18 cSt. A lubricating oil composition comprising a mixture of at least two Fischer-Tropsch derived base oils and one or more additives.

Applicants have blended a relatively high viscosity Fischer-Tropsch derived base oil with a low viscosity Fischer-Tropsch derived base oil to eliminate the need for the addition of a viscosity modifier and SAE “xW-y” viscosity lubricants. We have found that the properties of the formulation can be achieved. Applicants have further obtained lubricants that do not contain such viscosity modifiers without the need for the addition of a poly-α-olefin co-base oil as shown in WO-A-0157166. I found out that Therefore, a lubricating oil containing no Fischer-Tropsch derived base oil and containing a viscosity modifier completely can be advantageously blended. Applicants have also found that no residue build-up behind the inlet valve edge occurs when a lubricant containing no viscosity modifier is used as an automotive engine lubricant in a gasoline direct injection engine (GDI).
In particular, it has been found that lubricating oil formulations with SAE “xW-y” viscosities with y-x of 25 or more can be produced without the need to add viscosity modifiers. In accordance with the teachings of WO-A-0157166, it was expected that such formulations could only be produced if it required the addition of viscosity modifiers.

  The pour point of a Fischer-Tropsch derived base oil (also referred to as “low viscosity component”) having a kinematic viscosity at 100 ° C. of less than 7 cSt is preferably less than −18 ° C., more preferably less than −30 ° C. The kinematic viscosity at 100 ° C. is preferably more than 3.5 cSt, more preferably in the range of 3.5 to 6 cSt. The viscosity index (VI) is preferably greater than 120, more preferably greater than 130. VI is typically less than 160. The Noack volatilization loss (according to CEC L40 T87) is preferably less than 14% by weight. This low viscosity component is, for example, EP-A-776959, EP-A-668342, WO-A-9721788, WO-0015736, WO-0014188, WO-0014187, WO-0014183, WO-0014179, WO-0008115, WO Any Fischer-Tropsch derived base oil, as disclosed in -9941332, EP-1029029, WO-0118156 and WO-0157166.

  The other (second) Fischer-Tropsch derived base oil having a kinematic viscosity at 100 ° C. exceeding 18 cSt is also referred to as a “high viscosity component”. The kinematic viscosity at 100 ° C. of the high viscosity component is preferably in the range of 20 to 40 cSt, more preferably 20 to 30 cSt. The pour point may suitably be in the range of −50 to + 20 ° C. It has been found that the pour point of this heavy base oil is critically lower, and even base oils with a pour point above 0 ° C. do not adversely affect the temperature characteristics of the final lubricating oil formulation. The viscosity index is preferably above 150, more preferably in the range of 160-190. This class of Fischer-Tropsch derived base oil is considered novel.

The volume ratio of low viscosity component to high viscosity component in the final base oil can be determined by utilizing well-known blending rules based on the properties of the starting components and the intended desired SAE xW-y lubricating oil formulation. Preferably, the lubricating oil composition contains 65 to 95 weight percent Fischer-Tropsch derived base oil. The balance of the composition consists of one or more additives that do not contain a viscosity modifier .

The present invention is also directed to a method of generally using heavy grade base oils as described above in automotive oil formulations that do not require viscosity modifiers. The heavy base oil, because the you incorporated into the lubricating oil formulation may be combined with other Fischer-Tropsch derived base oil.
The lubricating oil composition of the present invention contains no viscosity adjusting agent. The lubricating oil composition may contain one or more other additives as described, for example, in WO-A-0157166. Types of additives that form part of the composition, such as dispersants, detergents, extreme pressure / antiwear agents, antioxidants, pour point depressants, emulsifiers, demulsifiers, corrosion inhibitors, rust inhibitors Agents, antifouling agents and friction modifiers. Specific examples of these additives are described, for example, in Kirk-Othmer Encyclopedia of Chemical Technology, Volume 3, Volume 14, pages 477-526.

  A preferred antiwear additive is zinc dialkyldithiophosphate. Suitable dispersants are ashless dispersants such as polybutylene succinimide polyamines or Mannic base type dispersants. Suitable detergents are over-based metal detergents, for example phosphonate, sulfonate, phenolate or salicylate types as described in the above general textbooks. Suitable antioxidants are hindered phenols or amine compounds, such as alkylated or styrenated diphenylamines, or ionol-derived hindered phenols. Suitable antifoaming agents are polydimethylsiloxane, and polyethylene glycol ethers and esters.

A preferred method capable of producing both a low viscosity base oil component and a high viscosity base oil component is described below.
This method includes a hydrocracking / hydroisomerization step on a relatively heavy feed obtained in a Fischer-Tropsch synthesis step. A dewaxing step is subsequently performed on the fraction of the effluent from the hydrotreating step that includes a base oil precursor fraction having a boiling point in the boiling range of the base oil. The low and heavy base oil components are then isolated from the dewaxed effluent stream.

The relatively heavy raw material for the hydrocracking / hydroisomerization step preferably has a weight ratio of a compound having 60 or more carbon atoms to a compound having 30 or more carbon atoms, preferably at least 0.2. Is at least 0.4, more preferably at least 0.55. Further, this raw material contains at least 30% by weight, preferably at least 50% by weight, more preferably at least 55% by weight, of a compound having 30 or more carbon atoms. Such a feed preferably contains a Fischer-Tropsch product. Furthermore, the Fischer-Tropsch product has an ASF-α value (Anderson-Schulz-Flory chain growth factor) of at least 0.925, preferably at least 0.935, more preferably at least 0.945, even more preferably at least Contains 0.955 C ₂₀ + fraction. It is preferable that neither a compound having 4 or less carbon atoms nor a compound having a boiling point in the range of the boiling point is present in the raw material. The feed may also contain non-standard base oil fractions such as obtained after process recycle and / or dewaxing.

Suitable Fischer-Tropsch synthesis methods that result in relatively heavy Fischer-Tropsch products are described, for example, in WO-A-9934917 and AU-A-698392.
The hydrocracking / hydroisomerization step is preferably performed in the presence of hydrogen and a catalyst known to those skilled in the art as being suitable for the reaction. Examples of these methods are described in WO-A-0014179, EP-A-532118, EP-A-666894 and EP-A-776959. A typical catalyst useful in this process is platinum (Pt) 0.8 wt% amorphous silica-alumina with a surface area of 392 m ² / g and a pore volume measured with a mercury porosimeter of 0.59 ml / g. It is a catalyst. Other catalysts useful for this hydrotreating step include nickel (Ni) 2.5-3.5 wt%, copper (Cu) 0.25-0.35 wt%, amorphous silica-alumina 65-75% by weight, an alumina binder contains 25 to 35 wt%, the surface area of the final catalyst is in 290~325m ² / g, total pore volume (Hg) is at 0.35-0.45 ml / g, compression An amorphous silica-alumina catalyst having a bulk density of 0.58 to 0.68 g / ml.

  The hydrocracking / hydroisomerization step is preferably performed at a reaction temperature in the range of 175 to 380 ° C, preferably higher than 250 ° C, more preferably in the range of 300 to 370 ° C. The pressure is usually in the range of 10 to 250 roses, preferably 20 to 80 roses. Hydrogen may be supplied at a gas hourly space velocity of 100 to 10,000 Nl / l / hr, preferably 500 to 5000 Nl / l / hr. The hydrocarbon feed is fed at an hourly space velocity of weight of 0.1-5 kg / l / hr, preferably higher than 0.5 kg / l / hr, more preferably lower than 2 kg / l / hr. It's okay. The ratio of hydrogen to hydrocarbon feedstock may be 100-5000 Nl / kg, preferably 250-2500 Nl / kg.

The conversion in the hydrocracking / hydroisomerization step is defined as the weight percentage (%) at which a feed having a boiling point higher than 370 ° C. reacts to a fraction having a boiling point lower than 370 ° C. per pass. This conversion rate is 20% by weight or more, preferably 25% by weight or more, preferably 80% by weight or less, more preferably 70% by weight or less. The feed used in the above definition is, for example, the total hydrocarbon feed including all recycle streams.
From the hydrocracking / hydroisomerization process effluent, a high-boiling fraction having a boiling point in the base oil range is isolated by distillation.

  Preferably, two base oil precursor fractions in the boiling range corresponding to the low viscosity component and the high viscosity component are isolated. These precursor fractions are obtained by vacuum distillation of the high boiling fraction. The initial boiling point of this base oil precursor fraction is preferably in the range of 330-400 ° C. The separation is carried out at about atmospheric conditions, preferably at a pressure in the range of 1.2 to 2 roses, preferably following the base oil precursor fraction, preferably isolating gas oil, naphtha and / or kerosene fraction. .

  Next, a dewaxing step (also referred to as a pour point lowering process) is performed on the base oil precursor fraction. The dewaxing process is described, for example, in Lubricant Base Oil and Wax Processing, Avilino Sequeia, Jr., Marcel Decker Inc. , New York, 1994, Chapter 7, so-called solvent dewaxing hydrocracking / hydroisomerization step. However, the dewaxing step is preferably performed by a catalytic dewaxing step. Catalytic dewaxing is well known to those skilled in the art and is preferably performed in the presence of hydrogen and a suitable heterogeneous catalyst. This heterogeneous catalyst is a catalyst having a combination of molecular sieves and optionally a metal having a hydrogenation function such as a Group VIII metal. Molecular sieves, and more preferably intermediate pore size zeolites, showed good catalytic ability to lower the pour point of the base oil precursor fraction under catalytic dewaxing conditions. Preferred intermediate pore size zeolites have a pore diameter in the range of 0.35 to 0.8 nm. Suitable intermediate pore size zeolites are mordenite, ZSM-5, ZSM-12, ZSM-22, ZSM-23, SSZ-32, ZSM-35 and ZSM-48. Another preferred molecular sieve group is silica-alumina phosphate (SAPO) material. Of these materials, SAPO-11 is most preferred, for example, as described in US-A-4859311. ZSM-5 can optionally be used in its HSMZ-5 form if no Group VIII metal is present. Other molecular sieves are preferably used in combination with the added Group VIII metal. Preferred Group VIII metals are nickel, cobalt, platinum and palladium. Examples of possible combinations are Ni / ZSM-5, Pt / ZSM-23, Pd / ZSM-23, Pt / ZSM-48 and Pt / SAPO-11. Further details and examples of suitable molecular sieve and dewaxing conditions are given in WO-A-9718278, US-A-5053373, US-A-5252527, US-A-45744043, US-A-5157191, WO-A-. 0029511 and EP-A-832171.

  Catalytic dewaxing conditions are known in the art, and usually the operating temperature is usually in the range of 200-500 ° C, preferably 250-400 ° C, and the hydrogen pressure is 10-200 bar, preferably 40- The hourly space velocity (WHSV) in the range of 70 bar is 0.1 to 10 kg (kg / l / hr) of oil per liter of catalyst per hour, preferably 0.2 to 5 kg / l / hr. hr, more preferably in the range of 0.5 to 3 kg / l / hr, and the hydrogen to oil ratio is in the range of 100 to 2,000 liters of hydrogen per liter of oil. In the catalytic dewaxing step, the flow varies preferably from less than −60 ° C. to −10 ° C. by changing the temperature in the range of 40-70 bar, 275 ° C., more preferably in the range of 315 ° C. to 375 ° C. It is possible to produce a low viscosity base oil component having a point value.

The low boiling non-base oil fraction is preferably first removed from the dewaxing step effluent, preferably by distillation, optionally in combination with an initial flush step. After removal of these low boiling compounds, the dewaxed product is separated into at least a low viscosity base oil component and a high viscosity base oil component, preferably by distillation. The high viscosity base oil component is preferably such a distillation bottom product (in other words, the highest boiling fraction).
The invention is illustrated by the following non-limiting examples.

Example 1
The C ₅ to C 750 ° C. ⁺ fraction of the Fischer-Tropsch product obtained in Example VII with the catalyst described in Example III of WO-A-9934917 was continuously fed to the hydrocracking process. This feed contained about 60% by weight of C ₃₀ + product. The C ₆₀ + / C ₃₀ + ratio was about 0.55. In the hydrocracking step, this fraction was contacted with the hydrocracking catalyst described in Example 1 of EP-A-532118. The effluent of step (a) was continuously distilled under vacuum to obtain a light product, fuel and residue “R” having a boiling point of 370 ° C. or higher. The yield of gas oil fraction relative to fresh feed to the hydrocracking process was 43% by weight. Table 3 shows the characteristics of the gas oil fraction thus obtained.

Most of the residue “R” was recycled to the process and the remainder was sent to the catalytic dewaxing process. The conditions for the catalytic cracking process were: hourly space velocity (WHSV) = 0.8 kg / l. h, WHSV of recycle material = 0.25 kg / l. h, hydrogen gas velocity = 1000 Nl / kg, total pressure = 40 bar, and reactor temperature = 335 ° C.
In the dewaxing step, the above-mentioned fraction in the range of boiling point 370 ° C. to over 750 ° C. contains 0.7% by weight of Pt and 30% by weight of ZSM-5 as described in Example 9 of WO-A-0029511. Was contacted with a dealuminated silica bonded ZSM-5 catalyst. The dewaxing conditions were: hydrogen = 40 bar, WHSV = 1 kg / l. h and temperature = 365 ° C.

  The dewaxed oil has a base oil fraction in the boiling range of 305 to 420 ° C. (yield to the raw material to the dewaxing process is 16.1% by weight), a base oil fraction in the boiling range of 420 to 510 ° C. (to the dewaxing process) The base oil fraction was 16.1 wt%) and the base oil fraction having a boiling point higher than 510 ° C. (yield based on the feed to the dewaxing process was 27.9 wt%). Base oil fractions in the boiling range of 420-510 ° C. and heavier fractions were analyzed in more detail (see Table 1).

Production of dewaxing catalyst used in Examples 2 and 3:
Using tetraethylammonium bromide as a template, MTW-type zeolite microcrystals were produced as described in Micropores and mesopores materials, Vol. 22 (1998), pages 644-645, “Verified synthesis of zeolitic materials”. The particle size visually observed with a scanning electron microscope (SEM) showed 1-10 μm ZSM-12 particles. The average crystallite size measured with the XRD line magnification technique was 0.05 μm. The microcrystals thus obtained were extruded together with a silica binder (zeolite 10% by weight, silica binder 90% by weight). The extrudate was dried at 120 ° C. (NH ₄ ) ₂ SiF ₆ solution (45 ml of 0.019N solution per 1 g of zeolite microcrystals) was poured into the extrudate. The mixture was then heated at 100 ° C. under reflux for 17 hours with gentle stirring over the extrudate. After filtration, the extrudate was washed twice with deionized water, dried at 120 ° C. for 2 hours, and then calcined at 480 ° C. for 2 hours.

  The extrudate thus obtained was immersed in an aqueous solution of platinum hydroxide tetramine, dried (at 120 ° C. for 2 hours), and further calcined (at 300 ° C. for 2 hours). The catalyst was activated by reducing platinum at a temperature of 350 ° C. for 2 hours under a hydrogen rate of 100 l / hr. The resulting catalyst supported 0.35 wt% Pt on dealuminated silica-bound MTW zeolite.

Example 2
A partially isomerized Fischer-Tropsch derived wax having the properties shown in Table 2 is added to a light base oil precursor fraction having a boiling range of about 390-520 ° C and a heavy base oil precursor fraction having a boiling point higher than 520 ° C. Distilled on.

The heavy base oil precursor fraction was contacted with the dewaxing catalyst. The dewaxing conditions were: hydrogen = 40 bar, WHSV = 1 kg / l. h, temperature = 340 ° C., hydrogen gas velocity = 700 Nl / kg raw material.
The dewaxed oil was distilled into two base oil fractions having the properties shown in Table 3.

The light base oil precursor fraction was also dewaxed catalytically by contacting with the dewaxing catalyst. The dewaxing conditions were: hydrogen = 40 bar, WHSV = 1 kg / l. h, temperature = 310 ° C., hydrogen gas velocity = 700 Nl / kg raw material.
The dewaxed oil was distilled into two base oil fractions having the properties shown in Table 4.

  As mentioned above, distillation of the dewaxed effluent of the heavy base oil precursor fraction and the light base oil precursor fraction was performed separately. It will also be apparent to those skilled in the art that these effluent streams can be combined prior to distillation into various base oil products.

Example 3
Example 2 was repeated starting from a partially isomerized Fischer-Tropsch derived wax having the properties shown in Table 5. This feed was distilled into a light base oil precursor fraction having a boiling range of approximately 390-520 ° C and a heavy base oil precursor fraction having a boiling point higher than 520 ° C.

The heavy base oil precursor fraction was contacted with the dewaxing catalyst. The dewaxing conditions were: hydrogen = 40 bar, WHSV = 1 kg / l. h, temperature = 355 ° C., hydrogen gas velocity = 700 Nl / kg raw material.
The dewaxed oil was distilled into two base oil fractions having the properties shown in Table 6.

Example 4
This example shows how a heavy Fischer-Tropsch derived base oil grade can be used as part of a 5W-30 lubricating oil composition according to the so-called SAE J300 classification without the use of viscosity modifiers. The properties of the Fischer-Tropsch derived base oil and the resulting lubricating oil are shown in Table 7.

Claims (8)

One Fischer-Tropsch derived base oil is a low viscosity component having a kinematic viscosity at 100 ° C. of less than 7 cSt and a viscosity index exceeding 120 , and the other Fischer-Tropsch derived base oil has a kinematic viscosity at 100 ° C. There exceeded 18CSt, and the two Fischer-Tropsch derived base oils Ru high viscosity component der ranging viscosity index 150-190, dispersants, detergents, extreme pressure / antiwear agents, antioxidants, pour point SAE “xW-y” comprising a mixture with one or more additives selected from the group consisting of a depressant, an emulsifier, an emulsion breaker, a corrosion inhibitor, a rust inhibitor, a pollution inhibitor and a friction modifier. (However, y-x is 25 or more) A lubricating oil composition containing no viscosity modifier . The lubricating oil composition containing no viscosity modifier according to claim 1, wherein the pour point of the low viscosity component is less than -18 ° C. The lubricating oil composition containing no viscosity modifier according to claim 2 , wherein the pour point of the low viscosity component is less than -30 ° C. The lubricant kinematic viscosity at 100 ° C. of low viscosity component Ri range der of 3.5～6CSt, either One Noack volatility does not contain a viscosity modifier according to claim 2 or 3 is less than 14 wt% Oil composition . The lubricating oil composition containing no viscosity modifier according to any one of claims 1 to 4 , wherein the high viscosity component has a kinematic viscosity at 100C of 20 to 40 cSt. The lubricating oil composition containing no viscosity modifier according to claim 5 , wherein the pour point of the high viscosity component is in the range of -15 to + 20 ° C. The lubricating oil composition containing no viscosity modifier according to any one of claims 1 to 6 , wherein the content of all Fischer-Tropsch derived base oils is in the range of 65 to 95% by weight. The lubricating oil composition containing no viscosity modifier according to any one of claims 1 to 7 is used to lubricate the gasoline direct injection engine.