Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M171/00—Lubricating compositions characterised by purely physical criteria, e.g. containing as base-material, thickener or additive, ingredients which are characterised exclusively by their numerically specified physical properties, i.e. containing ingredients which are physically well-defined but for which the chemical nature is either unspecified or only very vaguely indicated
  • C10M171/02—Specified values of viscosity or viscosity index
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2205/00—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
  • C10M2205/17—Fisher Tropsch reaction products
  • C10M2205/173—Fisher Tropsch reaction products used as base material
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/02—Pour-point; Viscosity index
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/06—Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/68—Shear stability
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/08—Hydraulic fluids, e.g. brake-fluids

Definitions

• the present invention relates to a lubricating composition, and hydraulic fluids comprising the lubricating composition.
• Lubricating oil compositions are widely used as hydraulic fluids in e.g. manufacturing, construction and transportation.
• High viscosity index is required for hydraulic oils dedicated to mobile or stationary equipment that is subjected to outside temperatures or which is particularly sensitive to temperature changes. Oil that has a high VI shows less variation in viscosity with temperature, i.e. it remains viscous enough to act as an effective lubricant at the highest temperatures and fluid enough at low temperatures to be pumpable.
• a "multigrade" hydraulic fluid i.e. a fluid with a relatively high viscosity index (VI), (e.g. > 140) which can be used in equipment where operating temperatures can vary significantly
• VI viscosity index
• the formulator can obtain the desired VI by proper selection of type and amounts of the base oil and VI improver.
• API Group I mineral oils commonly have a viscosity index of 90-100.
• Other types of base oils such as poly-alpha-olefin (PAOs) and esters may have a VI about 135 and 160 respectively.
• VI improvers VI modifiers
• thickening agents such as those obtained by copolymerizing these with nitrogen-containing monomers.
• the thickening or VI adding power of a VI modifier usually increases with its molecular weight. However, with increasing molecular weight of the VI improver shear stability decreases. "Shear stability" is the tendency of the large (usually polymer) molecules to be degraded during use as they pass around the hydraulic system.
• the formulator needs to carefully select the base oil (or base oil mixture), thickening power and shear stability in order to formulate a composition that meets the desired targets.
• a lubricating composition comprising (i) a Fischer-Tropsch derived base oil, and (ii) lubricant additive at a total level of at most 2% by weight, wherein the lubricating composition has a viscosity index of at least 140 and a kinematic viscosity at 40°C of at most 100 mm 2 /s, and wherein the lubricating composition is essentially free of polymeric viscosity index improver.
• compositions of the present invention have a high viscosity index without the need for polymeric viscosity improvers. It has also surprisingly been found that the compositions of the present invention have improved shear stability and extreme pressure properties.
• a Fischer-Tropsch derived base oil for improving the anti-wear performance of a lubricating composition
• the lubricating composition comprising (i) a Fischer-Tropsch derived base oil, and (ii) lubricant additive at a total level of at most 2% by weight, wherein the lubricating composition has a viscosity index of at least 140 and a kinematic viscosity at 40°C of at most 100 mm 2 /s, and wherein the lubricating composition is essentially free of polymeric viscosity index improver.
• a Fischer-Tropsch derived base oil for improving the shear stability of a lubricating composition
• the lubricating composition comprising (i) a Fischer-Tropsch derived base oil, and (ii) lubricant additive at a total level of at most 2% by weight, wherein the lubricating composition has a viscosity index of at least 140 and a kinematic viscosity at 40°C of at most 100 mm 2 /s, and wherein the lubricating composition is essentially free of polymeric viscosity index improver.
• the lubricating composition of the present invention has a Viscosity Index (according to ASTM D2280) of at least 140. In one embodiment, the lubricating composition has a Viscosity Index of at least 160. In another embodiment the lubricating composition has a Viscosity Index of at least 180.
• the lubricating composition of the present invention has a kinematic viscosity at 40°C (according to ASTM D445) of at most 100 mm 2 /s.
• the lubricating composition has a kinematic viscosity at 40°C of 32 mm 2 /s (i.e. ISO 32).
• the lubricating composition has a kinematic viscosity at 40°C of 46 mm 2 /s (i.e. ISO 46).
• the lubricating composition has a kinematic viscosity at 40°C of 68 mm 2 /s (i.e. ISO 68).
• the lubricating composition herein has a kinematic viscosity at 40°C of 100 mm 2 /s (i.e. ISO 100).
• the lubricating composition of the present invention comprises a Fischer-Tropsch derived base oil.
• the Fischer-Tropsch derived base oil is preferably present at a level in the range of from 80% to 99.5%, more preferably at a level in the range of from 90% to 99.5%, even more preferably at a level in the range of from 98% to 99.5%, by weight of the lubricating composition.
• Fischer-Tropsch derived base oils are known in the art.
• Fischer-Tropsch derived is meant that a base oil is, or is derived from, a synthesis product of a Fischer-Tropsch process.
• a Fischer-Tropsch derived base oil may also be referred to as a GTL (Gas-To-Liquids) base oil.
• Suitable Fischer-Tropsch derived base oils that may be conveniently used as the base oil in the lubricating composition are those as for example disclosed in EP 0 776 959 , EP 0 668 342 , WO 97/21788 , WO 00/15736 , WO 00/14188 , WO 00/14187 , WO 00/14183 , WO 00/14179 , WO 00/08115 , WO 99/41332 , EP 1 029 029 , WO 01/18156 and WO 01/57166 .
• the Fischer-Tropsch derived base oil for use herein preferably has a kinematic viscosity (according to ASTM D445) at 100°C in the range of from 4 mm 2 /s to 20 mm 2 /s, more preferably in the range of from 4 mm 2 /s to 10 mm 2 /s. Mixtures of two or more Fischer-Tropsch derived base oils may also be used herein.
• the Fischer-Tropsch derived base oil for use herein has a kinematic viscosity at 100°C in the range of from 4 to 6 mm 2 /s .
• the Fischer-Tropsch derived base oil for use herein has a kinematic viscosity at 100°C in the range of from 7 to 9 mm 2 /s.
• the Fischer-Tropsch derived base oil is a mixture of two Fischer-Tropsch derived base oils, one having a kinematic viscosity at 100°C in the range of from 4 to 6 mm 2 /s and the other having a kinematic viscosity at 100°C in the range of from 7 to 9 mm 2 /s.
• the lubricating composition of the present invention eliminates the need for high levels of polymeric viscosity improvers and are essentially free of polymeric viscosity improvers.
• polymeric viscosity index improvers include non-dispersant-type viscosity index improvers such as polymethacrylates and olefin copolymers such as ethylene/propylene copolymer and styrene/diene copolymer, and dispersion-type viscosity index improvers such as those obtained by copolymerizing these with nitrogen-containing monomers.
• the lubricating composition of the present invention is free of polymeric viscosity improvers, i.e. the lubricating composition comprises 0% by weight of polymeric viscosity improvers.
• the lubricating composition of the present invention may also contain one or more further base oils in addition to the Fischer-Tropsch derived base oil.
• the one or more further base oils may be selected from Group I-V base oils which, together with the Fischer-Tropsch derived base oil and the lubricant additive, provides a Viscosity Index for the lubricating composition of at least 140.
• Group I-V base oils in the present invention are meant lubricating oil base oils according to the definitions of American Petroleum Institute (API) categories I-V. Such API categories are defined in API Publication 1509, 15th Edition, Appendix E, April 2002 .
• API American Petroleum Institute
• Suitable base oils which may be used herein in addition to the Fischer-Tropsch derived base oil include Group IV base oils such as heavier PAO's (e.g. PAO 8 and upwards) and Group III wax isomerates such as those base oils commercially available from Shell under the tradename "XHVI".
• Group IV base oils such as heavier PAO's (e.g. PAO 8 and upwards)
• Group III wax isomerates such as those base oils commercially available from Shell under the tradename "XHVI”.
• the lubricating composition does not contain further base oils in addition to the Fischer-Tropsch derived base oil.
• the lubricating oil composition of the present invention further comprises one or more additives such as anti-wear additives, anti-oxidants, corrosion inhibitors, anti-foam agents, demulsifiers, pour point depressants, and mixtures thereof.
• the amount of said additives present in the lubricating composition depends on the specific compounds used. As the above-mentioned and other additives are well known in the art, they are not described herein in full detail.
• the total amount added of the additives is at most 2 wt%, preferably at most 1 wt%, more preferably at most 0.75 wt%, by weight of the lubricating composition.
• the total amount of additives present in the lubricating composition is preferably at least 0.5 wt%, more preferably at least 0.6 wt%, relative to the weight of the lubricating composition.
• anti-wear additives are zinc-based or zinc-free or ashless anti-wear additives.
• corrosion inhibitors are N-alkylsarcosinic acids, alkylate phenoxy acetates, imidazolines, the alkaline earth metal salts of phosphate esters disclosed in EP 0 801 116 and alkenyl succinate ester-based corrosion inhibitors.
• anti-oxidants examples include amine-based, sulphur based, phenol-based and phosphorus-based anti-oxidants. These antioxidants can be used individually, or a plurality can be used in combination.
• foam inhibitors are organo-silicates such as dimethylpolysiloxane, diethyl silicate and fluorosilicone, and non-silicone foam inhibitors such as polyalkyl acrylates.
• demulsifiers are polyalkylene glycol-based nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers and polyoxyethylene alkyl naphthyl ethers.
• pour-point depressants are polymethacrylate-based polymers.
• the lubricating oil composition according to the present invention can be conveniently prepared by blending together one or more base oils, and one or more lubricant additives.
• the lubricating composition is especially useful for formulating hydraulic fluid compositions.
• a hydraulic fluid composition comprising the lubricating composition described herein.
• the present invention also relates to the use of a Fischer-Tropsch derived base oil for improving the extreme pressure properties of a lubricating composition.
• the present invention further relates to the use of a Fischer-Tropsch derived base oil for improving the shear stability properties of a lubricating composition.
• Lubricating oil compositions were prepared by blending base oil and additives in the amounts as shown in Table 2 below.
• the base oil in Comparative Example 1 was mineral oil.
• the base oil in Example 1 was a mixture two GTL base oils having kinematic viscosities of 5.1 cSt (GTL 5.1) and 7.7 cSt (GTL 7.7) at 100°c.
• the physical characteristics of the two GTL base oils are displayed in Table 1 below.
• the GTL base oils can be prepared according to the method described in WO2004/07647 .
• API Group I Mineral Oil commercially available from Shell Netherlands B.V. (ex. Pernis refinery) having a Vk100 of 4.4-4.9 mm2/s 2.
• API Group I Mineral Oil commercially available from Shell Netherlands B.V. (ex. Pernis refinery) having a Vk100 of 10.7-11.8 cSt) 3.
• Performance Additive Package containing anti-wear additive, anti-oxidant, corrosion inhibitor and demulsifier

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Lubricants (AREA)

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Citations (19)

• 2010
  • 2010-05-03 EP EP10161712A patent/EP2385097A1/en not_active Withdrawn
• 2011
  • 2011-03-22 JP JP2011062058A patent/JP2011236407A/ja not_active Withdrawn

Patent Citations (19)

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