EP2162520A1 - Power steering fluid - Google Patents

Power steering fluid

Info

Publication number
EP2162520A1
EP2162520A1 EP08771991A EP08771991A EP2162520A1 EP 2162520 A1 EP2162520 A1 EP 2162520A1 EP 08771991 A EP08771991 A EP 08771991A EP 08771991 A EP08771991 A EP 08771991A EP 2162520 A1 EP2162520 A1 EP 2162520A1
Authority
EP
European Patent Office
Prior art keywords
base oil
power steering
steering fluid
molecules
viscosity
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP08771991A
Other languages
German (de)
French (fr)
Inventor
John M. Rosenbaum
Marc De Weerdt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Chevron USA Inc
Original Assignee
Chevron USA Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Chevron USA Inc filed Critical Chevron USA Inc
Publication of EP2162520A1 publication Critical patent/EP2162520A1/en
Withdrawn legal-status Critical Current

Links

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
    • C10N2020/00—Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
    • C10N2020/01—Physico-chemical properties
    • C10N2020/02—Viscosity; 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
    • C10N2030/02—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
    • C10N2030/08—Resistance to extreme temperature
    • 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
    • C10N2030/74—Noack Volatility
    • 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
    • C10N2040/04—Oil-bath; Gear-boxes; Automatic transmissions; Traction drives
    • 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
    • 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
    • C10N2070/00—Specific manufacturing methods for lubricant compositions

Definitions

  • Power steering fluids are an integral part of all power steering systems. Power steering fluid is used in about 80 to 90% of all vehicles in North America and Japan, as well as increasing numbers of vehicles in other parts of the world. Original Equipment Manufacturers have stringent specifications for power steering fluids. Requirements include high oxidation stability, high viscosity index, and compatibility with seals and hoses, In the past, power steering fluids used blends of naphthenic and solvent neutral base oils. Newer power steering fluids have been formulated with blends of naphthenic, solvent neutral, and hydrocracked base stocks. The hydrocracked base oils used in power steering fluids have had saturates contents of about 90 to about 99 mass %. Power steering fluids with improved viscosity index and lower Brooktield viscosity are needed.
  • a power steering ⁇ imd comprising greater than 50 weight
  • % base oil and viscosity index improver and having a viscosity index of greater than 2% and a Brookfield Viscosity at. -40 0 C of less than 1900 mPa-s,
  • the base oil has consecutive numbers of carbon atoms and has a viscosity index greater than a viscosity index calculated by the following equation;
  • a process for producing a power steering fluid comprising greater than 50 weight % base oil and having a viscosity index of greater than 290 and a BrookOeld Viscosity at -4O 0 C of less than 1900 raPa-s, the process comprising obtaining a base oil and blending the base oil with viscosity index improver to form the power steering fluid.
  • the base oil has consecutive numbers of carbon atoms: a kinematic viscosity at 100 0 C of kss than about 4 mm VU; and a Noack volatility less than a Noack Volatility Factor calculated by the following equation:
  • FIG. 1 is a graph of the Viscosity Index Factor calculated by the following equ ati on:
  • Viscosity hidex Factor :::' 28 x In(Ki siematic Viscosity at lOU'-Q + 10! . (1 ⁇
  • FIG. 2 is a graph of the Noaek Volatility Factor calculated by the fol lowing equations
  • Noack Volatility Factor :: 160 - 40(Kinematic Viscosity at 100' ' 'C); ( . 2)
  • Noack Volatility Factor Noack Volatility Factor :;; (90C) x (Kinematic Viscosity at I ⁇ O f -'C) *2 s ) - 1.5.
  • the base oil of the power steering fluid has a kinematic viscosity at 100 0 C between about 1 .2 mr ⁇ ⁇ /s and leas than about 4.0 mnr/s. a high viscosity index, low Cold Cranking Simulator (CCS) viscosity (less than 1500 mPa-s at -35X), and in an embodiment, cycioparaffm composition of greater than 5 weight % total molecules with cycloparaffmic functionality, and a ratio of molecules with monocycSoparaffmic functionality to molecules with rmilticyetoparaf ⁇ mic functionality of greater than 2.1 , such as greater than 5. greater than 10, greater than 15, or greater than 20.
  • CCS Cold Cranking Simulator
  • Poiyalphaolefin (PAO) oils are an oligomerization product of even carbon numbered linear alpha olefins, typically 1-dece ⁇ e,
  • the PAO oil molecules therefore., comprise a mixture of even carbon numbered hydrocarbon molecules, differing from each other in the .number of carbon atoms, by multiple* of the number of carbon atoms in the linear alpha olefin starting monomer.
  • the phrase "consecutive numbers of carbon atoms'' means that the base oii has a distribution of hydrocarbon molecules over a range of carbon numbers, with every number of carbon numbers in-between.
  • the base oil may have hydrocarbon molecules ranging from C 22 to Cj 6 or from € 3 0 to C «o with every carbon number in-between.
  • the hydrocarbon molecules of die base oil of the power steering fluid differ from each other by consecutive numbers of carbon atoms, as a consequence of the waxy feed also having sequential numbers of carbon atoms.
  • the source of carbon atoms is CO and the hydrocarbon molecules are built op one carbon atom at a time.
  • Petroleum-derived waxy feeds also have sequential numbers of carbon numbers, in contrast to an oil baaed on PAO, the molecules of the base oil of the power steering fluid disclosed herein have a more linear structure, comprising a relatively long backbone with short branches.
  • the classic textbook description of a PAO is a star-shaped molecule, and in particular tridecane, which is illustrated as three decan ⁇ molecules attached at a centra! point While a star-shaped molecule is theoretical, nevertheless PAO molecules have fewer and longer branches than the hydrocarbon molecules that make up the base oil of the power steering fluid fOOlOJ
  • the base oil of the power steering fluid comprises consecutive numbers of carbon atoms.
  • the power steering fluid comprises greater than 50 weight % base oil; and viscosity index improver in an amount less than 13 weight %, or less than 12 weight %.
  • the power steering fluid comprises between 0 and less than about 1.0 weight % pour point depressant.
  • the power steering fluid has a Brookiieid Viscosity at -40 0 C of less than 1900 mPa-s.
  • the power steering fluid in an embodiment, comprises a detergent-inhibitor additive package, tor example, 2 to 6 weight % or 5 weight % detergent- inhibitor additive package. f ⁇ Ol 1 J l ⁇ an embodiment, the power steering fluids (e g.
  • power steering fluids used in automotive power steering systems or are suitable for power steering fluid service fill replacement.
  • power steering fluid specifications are; Daimler/Chrysler MS593 LF, DamiierChrysIer MS 1872, Ford M2C138-C.L Ford M2C33-F, Ford ESW-M2C12S-C & D, GM 998501Q 5 Navistar TMS 68! ( X and Volkswagen TL-VW-S70-26.
  • power steering fluid part numbers are: Aeura/Tlonda Part Number 08206-9002 PE. Audi Part Number O002000, Mercedes Benz Part Number 00 989 8803, Saab Part Number 30 09 800, and Subaru Part Number K0Z09A0080.
  • Fischer- Tropsch derived base oils contain greater than 95 weight % or greater than 99.0 weigh! %, or greater than 99.5 weight % saturates, which in addition distinguishes them from most hydrocracked base oils used previously m power steering fluids. Because of their good properties, Fischer- Tropsch derived base oils with viscosities between about 1.2 and about 4.0 mnf/s at I Q(PC can be blended into powei steering fluids.
  • Fischer-Tropsch derived base oils have inherently good lubricant characteristics, due to their content of molecules with cycloparaffiriic functionality, and therefore have natural lubricity, wear resistance, solvency and seal compatibility. Fischer-Tropsch derived base oils also are fully compatible with naphthe ⁇ ic and solvent neutral base oils, and when combined with oilier types of base oils make a base oil blend that is further enhanced in the aforementioned lubricant characteristics, especially, in their compatibility with the elastomers in the seals and hoses of power steering systems,
  • ⁇ V ⁇ J.1 have the following meanings unless otherwise indicated.
  • the term “Fiseher-Tr ⁇ psch derived” means that the product, fraction, or feed originates liom or is produced at some stage by a Fischer-Tropseh process. [00 ⁇ 5J
  • the term “petroleum derived” means that the product., fraction, or feed originates from the vapor overhead streams from distilling petroleum crude and the residual fuels that are the non-vaporizable remaining portion.
  • a source of the petroleum derived product, fraction, or feed can be from a gas field eo.nde.rj sate.
  • Highly paraffinie wax means a wax .having a high content oi ' n- paraffi ⁇ s, generally greater than 40 weight %, but can be greater than 50 weight %, or even greater than 75 weight %.
  • the his>hiv paraffinie waxes also have very low levels of nitrogen and sulfur, generally less than 25 ppm total combined nitrogen and suiter, for example, less than 20 ppm.
  • highly paraffime waxes examples include slack waxes, deoiled slack waxes, refined foots oils, waxy lubricant raf ⁇ oat ⁇ s, n-paraff ⁇ n waxes, NAO waxes, waxes produced in chemical plant processes, deoiled petroleum derived waxes, microcrystalline waxes, Fischer- Trop.sch waxes, and mixtures thereof.
  • the pour points of the highly paraffime waxes are greater than SO 0 C or greater than 6O 0 C.
  • the term "derived from highly paraffinie wax” means that the product, fraction, or feed originates iro ⁇ i or is produced at some stage by from a highly paraffin! c wax.
  • any hydrocarbonaceous compounds thai contain at least one group of atoms that share an uninterrupted cloud of deioeaHzed electrons, where the number of deioca ⁇ zed electrons in the group of atoms corresponds to a solution to the Hneke! rule of 4a 4- 2 ⁇ e.g.. n ::: 1 for 6 electrons, etc.).
  • Representative examples include., hut are not limited to, benzene, hiphenyl. naphthalene, and the like.
  • Molecules with cycloparaffmic functionality mean any molecule that is, or contains as one or more substituents, a monocyclic or a fused muhieydie saturated hydrocarbon, group.
  • the cyeloparaffinic group can be optionally substituted with one or more, such as one to three, substiuients.
  • Representative examples include, but are no* limited to, cycl.opropyi, cydobutyL cyelohexyL. cycjope ⁇ tyl.
  • Molecules with nionocycloparafluiic functionality mean any molecule that is a monocyclic saturated hydrocarbon group of three to seven ring carbons or any molecule that is substituted with a single monocyclic saturated hydrocarbon group of three to seven ring carbons.
  • the cycloparaffhsic group CUB be optionally substituted with one or more, such as one to three, subsiituents.
  • Molecules with mnlticydoparai ' fniic functionality mean any molecule that is a fused m ⁇ lticyclic saturated hydrocarbon ring group of two or more fused rinasL anv rnolecule that is substituted with one or more fused multicvdk saturated hydrocarbon ring groups of two ⁇ i more fused rings, or any i ⁇ olecide that is substituted with more than one monocyclic saturated hydrocarbon group of three to seven ring carbons.
  • the fused nuslticyclie saturated hydrocarbon ring group often is of two fused rings.
  • the cycbparafftnic group can be optionally substituted with one or more, such as one to three, substituents.
  • Representative examples include, but are not limited to, decahydronaphthalen ⁇ , octahydyopeutaiene s 3.7,10- iricyciohexylpentadeeane, decahydro-l-(p ⁇ utadec;in-6-yl ⁇ naphtlialer ⁇ e, ai ⁇ d the like.
  • Kinematic viscosity is a measurement of the resistance to flow of a fluid under gravity. Maisy base oils, power steering fluids made from them, and the correct operation of equipment depends upon the appropriate viscosity of the fluid being used. Kinematic viscosity is determined by ASTM D445-06.
  • Piscber-Tropsc.h derived base oil has a kinematic viscosity of between about 1 .. '• mnr/s and about 4.0 mrrr/s at 100 0 C.
  • base oil derived from highly paraffu ⁇ c wax has a kinematic viscosity of between about 1.5 raaf/s and about 3.5 rnmV ' s
  • base oil derived from high paraffmk wax has a kinematic viscosity of between about 2.0 rnnrVs and about 3.5 innf/s at HK) 0 C
  • base oil derived from highly paralTiiiic wax has a kinematic viscosity of between about 2.0 nmvV's and about 3.0 r ⁇ vVs at 1OC) 0 C
  • Viscosity index (VI) is an empirical, unitk-ss number .indicating the effect of temperature change on the kinematic viscosity of the oil. Viscosity index is determined by ASTM D2270-04. in an embodiment, base oil derived from highly paraffinic wax has a viscosity index of greater than 10 L In an embodiment, base oi 1 derived from highly paraffmic wax has a viscosity index of between about 105 and about 160.
  • Viscosity Index Factor of base oil derived from highly paraffinic. wax is an empirical number derived from kinematic viscosity of the base oil.
  • the Viscosity Index Factor is calculated by the following equation:
  • Viscosity Index Factor ⁇ 28 x ln(Kinematk Viscosity at HJO 0 C) + 101 ( 1 ) wherein "In” is the logarithm function to the base f V.
  • Base oil derived from highly paraffinic wax can have a viscosity index greater than the Viscosity Index Factor.
  • F(G. 1 is a graph of the Viscosity Index Factor according to the above equation.
  • Earlier base oils derived from high] ⁇ - paraffinic wax having high viscosity indexes derived from kinematic viscosity of the base oil such as those taught in U.S. Patent No. 7,083,713, are also usefhl m power steering fluids.
  • the base oils useful in the compositions of the power steering fluid disclosed herein have viscosity indexes that are higher than the viscosity indexes of those taught in U.S. Patent No. 7,083,713.
  • the higher viscosity index of the base oil (Viscosity index Factor) of the power steering fluid disclosed herein contributes to the improved properties (high viscosity index and low Brookfieki Viscosity) of the power steering fluid.
  • pour poh.n is a measurement of the temperature at which a sample of base oil will begin to flow under carefully controlled conditions, Pour point can be determined as described in ASTM D5950-02. The results are reported in degrees Celsius. Many commercial base oils have specifications for poor point. When base oils have low pour points- the base oils are also likely to have other good low temperature properties, such as low cloud point, low cold filter plugging point, and low temperature cranking viscosity
  • Procedure B A more convenient method for calculating Noaek volatility and one which correlates well with ASTM D58G0-Q5 is by using a the ⁇ no gravimetric analyzer (TGA) test by ASTM D6375-05,
  • base oil derived from highly paraffmie wax has a Noack volatility of less than 100 weight %, Noack volatility of base oils generally increases as the kinematic viscosity decreases. The lower the Noack volatility, the lower the tendency of base oil and formulated oils to volatilize in service.
  • the "Noack Volatility Factor" of base oil is an empirical number derived from the kinematic viscosity of the base oil
  • the Noack volatility of the base oil derived from highly par ⁇ ffkdc wax is veiy low. and in an embodiment, is less than m ⁇ amount calculated by the equation:
  • Noack Volatility Factor :: 160 ⁇ 40(Kinematic Viscosity at I DO 0 C), (2s
  • Equation (2) provides Noack Volatility Factors between 0 and 100 for kinematic viscosities between 1.5 and 4.0 mm'V ⁇
  • FKl 2 is a graph of ihe Noack Volatility Factor according to Equation (2).
  • the Noack volatility of the base oil derived from highly paraffmie wax is less than an amount calculated by the equation:
  • Noack Volatility Factor ::: (900 x (Kinematic Viscosity ai 10O 0 Cp ⁇ ) ⁇ - 15.
  • Equation (3) provides Noack Volatility Factors between 0 and 100 for kinematic viscosities between 2.09 and 4,3 ⁇ M ⁇ /S, FIG, 2 also includes the Noack Volatility .Factor according to Equation (J). For kinematic viscosities in the range of 2,4 to 3.8 mnfVs, Equation (3) provides a lower Noack Volatility Factor than does Equation (2).
  • the aniline point temperature which is the lowest temperature (T or "C) at which equal volumes of aniline (C 6 HjNH 2 ) and the oil form a single phase.
  • the aniline point is determined by ASTM D6U-04.
  • the base oil of the power steering fluid derived from highly paraffioie wax, have an aniline point greater than 36 x in( Kinematic Viscosity at 100 0 C) ⁇ 200. Accordingly, base oil derived from highly paraffin ie wax exhibits good elastomer compatibility, and performs well with the seals and hoses in power steering systems.
  • the highly para ⁇ nic was. used in making the base oi 1 of the power steering fluid can be any wax having a high content of n-paraffios and having consecutive numbers of carbon atoms.
  • the highly paraffmie wax comprises greater than 40 weight % ⁇ -paraffuis, such as greater than 50 weigh!. %, or greater than 75 weight %.
  • the highly paraffmie waxes also have very low levels of nitrogen and sulfur, generally less ihan 25 ppm total combined nitrogen and sulfur, for example less than 20 ppm.
  • highly paraffinic waxes examples include slack waxes, deoiled slack wax.es, refined ibois oils, waxy lubricant ralllnates, n- paraffm waxes, NAO waxes, waxes produced in chemical plant processes, deoiled petroleum derived waxes, microcrystal ⁇ ne waxes, Fischer-Tropseh waxes, and mixtures thereof,
  • the pour points of the highly pa ⁇ iffink waxes are greater than 50 ⁇ J C or greater than 60"(I
  • the highly paraffimc wax is a Fischer-Tropsch derived wax and provides a Fischer- Tropsch derived base oil.
  • the Fischer- 1 ropsch synthesis products can be obtained by well- known processes such as, for example., the commercial SASOI.* ' Slurry Phase Fischer-Tropsch technology, the commercial SFiELL* Middle Distillate Synthesis (SMDS) Process, or by the Bon-eommerciai EXXON '?: Advanced Gas Conversion ( AOC-21 ) process, Details of these processes and others art: described in, for example, EP-A ⁇ 776959, I?:P-A-668342, EP-B- 450860; U.S. Patent Nos. 4,943.672. 5i)S9,299, 5,348,982, S S 733,839 and RE39073; U.S. Application Publication No.
  • ' ITie FLscher- ' ⁇ ' ropsch syntliesis product usually comprises hydrocarbons having 1 to 100, or even more than 100 carbon atoms, and typically includes paraffins, oieilns and oxygenated products.
  • the slurry Fischer-Tropsch process utilizes superior heat (and mass) transfer characteristics for the strongly exothermic synthesis reaction and is able to produce relatively high molecular weight, paraflhiic hydrocarbons when using a cobalt catalyst.
  • Fischer-Tropsch catalysts are known to provide relatively high chain growth probabilities, and the reaction products include a relatively low proportion of low molecular ⁇ C?,x) weight olefins aad a relatively high proportion of high molecular weight (Cso--) waxes.
  • Such catalysis are well known to those of skill in the art and can be readily obtained ami/or prepared.
  • the product from a Pischcr-Tr ⁇ psch process contains predominantly paraffins
  • the products from Fischer-Tropsch reactions generally include a light reaction product and a waxy reaction product.
  • the waxy reaction product i.e., the waxy fraction
  • hydrocarbons boiling above about 600 0 F e.g., vacuum, gas oil through heavy paraffins
  • the waxy reaction product generally comprises greater than 70 weight % normal paiaffim, and often greater than 80 weight % normal paraffins, ft is the waxy reaction product ⁇ i.e., the waxy fraction) that is used as a feedstock to the process for providing Fischer-Tropsch derived base oil in power steering fluids.
  • the Fischer-Tropsch base oil of the power steering fluid can be prepared .from the waxy fractions of the Fischer. -Tropsch syncrude by a process including hydroisomerization. !.n an embodiment, the Fischer- Tr ⁇ pseh base oils are made by a process as described in U -S, Patent Application Publication Nos, 2005/0133409 Al and 2006/028933? Al.
  • the Fischer-Tropsch base oil of the power steering fluid is often manufactured at a site different from the site at which the components of the power steering fluids are received and blended.
  • the base oil of the power steering fluid is made by a process comprising providing a highly parafiloie wax and then hydroisomerizing the highly paraffinie wax to provide the base oil.
  • the highly paraffhiie wax is hydroisomerized using a shape selective intermediate pore size molecular sieve comprising a noble metal hydrogenation component under conditions of about 600' '1 F to ?50*F.
  • the highly paraffinic wax is a f ischer-Tropsch derived wax and ptovide.s a Fiseher-Tropsch derived base oil, Fischer- 1 ropsdi derived base oil can be made by a Fischer- Tropseh synthesis process followed by hydroisome ⁇ zafion of the waxy fractions of the Fischer-Tropsch. synemde,
  • The highly paraffmk; waxes are subjected to a process comprising hydroisomer ⁇ Kation to provide the base oil of ihe power steering tUikl. Hydroisornerization is intended to improve the cold flow properties of the base oil by the selective addition of branching into the molecular structure.
  • Rydroisomerizadon ideally will achieve high eon version, levels of the highly paratfmjc wax to non-waxy iso-paraffins while at the same time rninir ⁇ mng the conversion by cracking.
  • the conditions for hydrois ⁇ merization are controlled such that the conversion of the compounds boiling, above about 700 0 F in the waxy feed to compounds boiling below about 700 "5 F is maintained between about 10 and 50 weight %, for example between 15 and 45 weight %,
  • Hydroisomerizaliors is conducted using a shape selective intermediate pore size molecular sieve.
  • the hydroisomerizarkm catalysts used comprise a shape selective intermediate pore size molecular sieve and optionally a cataiytically active metal hydrogenation component on u refractory oxide support.
  • intermediate pore size means an effective pore aperture in the range of from about 3.9 to about 7.1 A when the porous inorganic oxide is in the calcined form.
  • shape selective intermediate pore size molecular sieves used are generally 1-D 10-, 1 1 ⁇ or 12-ring molecular sieves.
  • the molecular sieves are of the 1-D i ⁇ - ⁇ ng variety, where 10* (or I S -or 12- ⁇ ring molecular sieves have 10 for 1 1 or 12) tetrahedrally-coordinated atoms (T-atoms) joined by oxygens, in the i-0 molecular sieve, the 10-ring (or larger) pores are parallel with each other, and do not interconnect.
  • T-atoms tetrahedrally-coordinated atoms
  • 1 -D lO-ring molecular sieves which meet the broader definition of the intermediate pore size molecular sieve bin include intersecting pores having 8-membered rings can also be encompassed within the definition of molecular sieve.
  • an intermediate pore size molecular sieve is characterized by selected crystallographic free diameters of the channels, selected crystallite size (corresponding to selected channel length K and selected acidity.
  • Desirable crystallographic free diameters of the channels of the molecular sieves are in the range offro.ro about 3.9 to about 7.1 A, having a maximum crystal lographic free diameter of not more than 7,1 and a minimum erystallographk free diameter of not less than 3.9 A.
  • the maximum crystal lographic free diameter i ⁇ not more than 7.1 and the minimum crystailographic free diameter is not less than 4,0 A.
  • the maximum, erystallograpliic free diameter is not more than 6.5 and the minimum crystailographic free diameter is not less than 4.0 A.
  • 5,282,958 such an intermediate pore size molecular sieve lias a crystallite size of no more than about 0.5 microns and pores with a minimum diameter of at least about 4.8 A and with a maximum diameter o ⁇ about 7.1 A.
  • the catalyst has sufficient acidity so that 0,5 grams thereof when positioned in a tube reactor converts at least 50% of hexa ⁇ eane as. 370 0 C, a pressure of 1200 psig, a hydrogen flow of 160 rnlZmin, and a feed rate of 1 mi/hr.
  • the catalyst also exhibits is ⁇ metization selectivity of 40 percent or greater (isonierizatioo selectivity is determined as follows; 100 x (weight % branched C ⁇ , i ⁇ product) / (weight % branched Cj*, in product ⁇ ! ⁇ weight % Cp. in product) when used under conditions leading to 96% conversion of normal hexadecane (n-Cu;) to other species.
  • the molecular sieve can further be characterized by pores or channels having a. crystal iographie free diameter in the range of from about 4,0 to about 7.1 A, for example, in the range of 4.0 to 6,5 A.
  • the crystaliograp.hic free diameters of the channels of molecular sieves are published in the " ⁇ tlas of Zeolite Framework Types", Fifth Revised Edition, 2001 , by CIi. Baerlocher, W. ML Meier, and DJ-f Olson, Elsevier, pp 10-15, [0046J If the erysta ⁇ lographic free diameters of the.
  • the effective pore size of the molecular sieve can be measured using standard adsorption techniques and hydrocarbonaceous compounds of known minimum kinetic diameters. See Breck, Zeolite Molecular Sieves. 1974 (especially Chapter 8); Anderson et at J. Catalysis 58» 1 14 (1979); and ⁇ .S, Patent No. 4,440,871 . In performing adsorption measurements to determine pore size, standard techniques are used. It is convenient to consider a particular molecule as excluded if does not reach at least 95% of its equilibrium adsorption value on the molecular sieve in less than about 10 minutes CpZp 0 ::: (KS at 25 0 C). Intermediate pore size molecular sieves will typically admit, molecules having kinetic diameters of ,13 to 6,5 A wills, little hindrance,
  • (0047J Hydroisome ⁇ zaticn catalysts often comprise a eatalytically active hydrogenatioi) metal.
  • a caialyticaUy active hydrogenation metal leads to product improvement, especially viscosity index and stability.
  • Typical eatalytically active .hydrogmation metals include chromium, molybdenum, nickel, vanadium, cobalt, tungsten, zinc, platinum, and palladium.
  • the eaUiJyticaUy active hydrogen metals are selected from plairaum, palladium, and
  • the total amount of active hyd.rogenation metal is typically in ihe range of U.I to 5 weight percent of the total catalyst usually from 0.1 to 2 weight percent, and not to exceed 10 weight percent.
  • 0048j The refractory oxide support cars be selected from, those oxide supports, which are conventionally used for catalysts, including silica, a ⁇ u ⁇ rau silica-alumina, magnesia, litaula and combinations thereof, (01)49]
  • the conditions for hydroisorrseroation will be tailored to achieve a base oil comprising greater than 5 weight. % molecules with cydoparafilnic functionality.
  • the conditions provide a base oil comprising a ratio of weight percent of molecules with morioeycloparaffimc functionality of weight percent of molecules with m ⁇ lticyci ⁇ paraffmic functionality of greater than 5, such as greater than 10, greater than 15, or greater than 20.
  • the conditions for Iiydroisomerizaiion will depend on the properties of feed used, the catalyst used, whether or not the catalyst is sulf ⁇ ded, the desired yield, and the desired properties of the base oil.
  • Conditions under which ihe hydroisoraenxation process can be carried out include temperatures from about DOCF ' F to about ' /75'T (26(FC to about 415°C ⁇ such as 600 0 F to about 750T ⁇ 3 i 5 0 C io about 399 0 C), or 600 c F TO about 70CfF (3 l5°C to about 371"C); arid pressures from about 15 to 3000 psig, such as 100 to 2500 psig.
  • the hydroisomerizadon pressures in this context refer to the hydrogen partial pressure within the hydrotsor ⁇ erization reactor, although the hydrogen partial pressure is substantially the same (or nearly the same) as the total pressure.
  • the liquid hourly space velocity during contacting is generally from about 0,1 to 20 hx ' ⁇ : for example, from about 0.1 to about 5 h/ ! .
  • the hydrogen to hydrocarbon ratio falls within a range from about 1 0 to about 50 moles H ? per mole hydrocarbon, for example, from about 10 to about 20 moles H> per mole hydrocarbon.
  • Suitable corsdiuons for performing hydroisonierization are described in U.S. Patent Nos 5,282.958 and 5, 135.638.
  • JOOS(Jj Hydrogen is present in the reaction zone during the hydroisomerizatiori process, typically in a hydrogen to feed ratio from about 0.5 io 30 MSCP/bbi thousand standard cubic feet per barrel), such as from about 1 to about 10 MSCF/bbl.
  • the hydrogen to feed, ratio is from about 712.4 to about 3562 liter H?/Iiter oil (about 4 to about 20 MSCF/bbl , ⁇ Hydrogen will sometimes be separated from the product and recycled to the reaction zone.
  • Hydro finishing is a hydrotreaiing process that will often be used as a step following hydroisoraerizatio ⁇ . to provide base oil derived from highly paraffirue wax.
  • RydroSnishing is intended to improve oxidation stability, UV stability, and appearance of base oil by removing traces of aromatics, olefins, color bodies, and solvents.
  • UV stability refers to the stability of base oil or power steering fluids when, exposed to UV light and oxygen, instability is indicated when a visible precipitate forms, usually seen, as Doc or cloudiness, or a darker color develops upon, exposure to ultraviolet, light and air.
  • a general description of bydrofmishmg can be found m U.S. Patent Nos. 3,852,20? and 4,673,487.
  • Clay treating to remove impurities is an alternative final process step to provide base oil derived irom highly paraffinic wax.
  • the process to provide the light base oil derived from highly paraftinic wax cm include fractionating the highly paraffi ⁇ ic waxy feed prior to Uydroisomcrisation, or fractionating of base- oil obtained from the hydroisoraerization process.
  • the fractionation of the highly paraffinie waxy feed or the isomerized base oil into fractions is generally accomplished by either atmospheric or vacuum distillation, or by a com.bi.na don of atmospheric and vacuum distillation.
  • Atmospheric distillation is typically used to separate the lighter distillate fractions, such as naphtha and middle distillates, from a bottoms fraction having an initial boiling point above about 6OG 41 F to about 750"F (about 315° € to about 399*CX
  • Vacuum distillation is typically used to separate the higher boiling material.
  • base oil into different bo.ili.ng range cuts. Fractionating base oil into different boiling range cuts enables base oil manufacturing plant to produce more than one grade, or viscosity, of base oil.
  • the process to make base oil derived from highly paraffinic wax will sometimes also includes a solvent dewaxing step either before or following the hydroisomerization process.
  • Solvent dewaxing optionally can be used to remove small amounts of remaining waxy molecules from base oil after hydroisorneriza ⁇ on. Solvent dewaxing is done by dissolving base oil in a solvent, such as methyl ethyl ketone, methyl iso-butyi ketone, or toluene, or precipitating the wax molecules as discussed m Chemical Technology of Petroleum, 3rd Edition, William Gruse and Donald Stevens, McGraw-Hill Book Company, Inc.. New York. 1960, pages 566 to 570.
  • Solvent dewaxing is also described in U.S. Patent Nos. 4,477,333, 3,773,650 and 3.775,288. Ba ⁇ . OJl . Derived J ⁇ orn .. Hi£My .. Faiajllnic_Wax
  • Base oil derived from highly paraffinie wax is suitable for use in power steering fluids.
  • base oil derived from highly parafi ⁇ nie wax has a vis-c ⁇ shy of between about 12 ninvvs and about 4.0 mm'/s, such as between about 1.5 and about 3.5 mm"/s at !00" 1 C, or between about 2 nir ⁇ Vs and ⁇ about 3.5 rami's at 100 0 C, or between about 2 mra'Vs and about 3.0 m ⁇ r/s at ] 00 0 C.
  • lipase oil derived from highly paraffliric wax advantageously has a low Moaek volatility.
  • base oil derived from highly paraffinic wax has a Noack volatility between 0 and 100 weight %. and less than the Noack Volatility Factor as calculated by the following equation:
  • base oil derived .from highly paraffinie wax ha ⁇ a Noack volatility of less than 100 weight %, such as less than 50 weight % or 35 weight %. Accordingly, base oil derived from highly paraffinic wax advantageously has both high viscosity index and. low volatility,
  • base oil derived from highly paraffinic was. has a viscosity index of greater than 101.
  • base oil derived from highly paraffu ⁇ c wax has a viscosity index of between about S 05 and about 160.
  • the viscosity index of base oil derived from highly paraii ⁇ ni ⁇ wax is greater than the Viscosity index Factor a.s calculated by the fol lowing equation:
  • base oil derived from highly paraffinic wax comprises a weight % of molecules with cycloparaffinic functionality of greater than the kinematic viscosity at HMFC multiplied by three.
  • the base oil of the power steering fluid comprises less than 5 weight %. such as less than 1 weight % or (ess than 0.5 weight %, of unsaturates. In an embodiment the base oil of the power steering fluid comprises greater than 5 weight % molecules with cycloparaffinic functionality.
  • the base oil of the power steering fluid comprises a ratio of weight percent of molecules with rminocyeloparaffimc functionality to weight percent of molecules with .nmlticyeloparaffir ⁇ c functionality of greater than 5. such as greater than 10, greater than 15, or greater than 20,
  • the base oil of the power steering fluid generally comprises less than 0,30 weight percent molecules with aromatic functionality, such as less than 0.1 or less than 0.05 weight percent. (IHJ59J In.
  • the base oil of the power steering .fluid comprises greater than 5 weight percent molecules with eyc ⁇ oparaffi ⁇ ic functionality.
  • the base oil of the power steering fluid comprises a ratio of weight % of molecules with monocycloparaffmic functionality to weight % of molecules with ⁇ miticycloparaffmic functionality of greater than 5, such as greater than 10, greater than. 15, or greater than 20.
  • the base oil of the power steering fluid comprises a ratio of weight percent of molecules with cycloparaffeue functionality of greater than the kinematic viscosity at. I GO 0 C multiplied by three. JO06OJ
  • the base oil of the power steering fluid comprises less than 19 alky!
  • the base oil of the power steering fluid can also have specific alky! branching placements, In an embodiment, the base oil of the power steering fluid comprises predominantly methy! branching, and the branching is such that there are 6 to 18 alkyl branches per 100 carbons; greater than 25% of the branches are 5 or more carbon atoms apart from each oilier; and less than 4014 of the branches are within 2 io 3 carbon atoms apart from each other. Examples of these types of base oils are taught in U.S. Patent Application Publication No. 2005/0077208 Al.
  • Base oil containing desired levels of molecules with cyeioparafimic functionality exhibits good 3oh.sbii.ity for additives, including viscosity index improvers and lubricant additive packages, because molecules with cycioparaffmie functionality impart additive solubility.
  • the bass oil of the power steering fluid has an aniline point greater than 36 x In(Ki nomatic Viscosity at 100 0 C) + 200. Accordingly, the base oil exhibits good elastomer compatibility, and do not damage seals and hoses in power steering systems.
  • the base oil of the power steering Fluid contains greater than 95 weigh! % saturate ⁇ such as greater than 99 weight % or greater than 99.5 weight %, as determined by elation column chromatography, ASTM D2549- 02. Olefins are present in an amount less than detectable by long duration C l " Nuclear Magnetic Resonance Spectroscopy (NMR) 1 in an embodiment, molecules with aromatic functionality are present in amounts less than 0,3 weight percent by HPLC-UV, and confirmed by ASTM D5292-99 modified to measure low level aromaties. In an embodiment, molecules with aromatic functionality are present in amounts less than 0.10 weight percent, such as less than 0,05 weight percent, or less than 0,0.1 weight percent. Sulfur is present in amounts less than 25 ppm, such as 5 ppm. or less than 1 ppm as determined by ultraviolet fluorescence by ASTM D5453- 06.
  • Base oil derived from highly parar ⁇ ime wax does not. introduce any undesirable characteristics, including, for example, high volatility, high viscosity, and impurities such as heter ⁇ aioms, to the power steering liukl
  • the base oil is a Fiseher- ⁇ ropsch derived base oil.
  • Piseher-Tropsch derived waxes are particularly well suited for providing Fischer-Tropseh derived base oil with the above-described properties .
  • the method used to measure low levels of molecules with aromatic fuDctionalnv in the base oils uses a .Hewlett Packard 1050 Series Quaternary Gradient High Performance Liquid Chromatography (HPLC) system coupled with a MP HsSi) Diode- An ay UV -Vis detector interfaced Io an HP €hem-sta ⁇ on. Identification of the individual aromatic classes in the highly saturated base oils was made on the basis of their UY spectral pattern ami their elation time. The ami.no column used for this analysis differentiates aromatic molecules largely on the basis of their ri rag-number (or more correctly, double-bond number).
  • [006Sj H PLC-U V is used for identifying these classes of aromatic compounds even at very low levels.
  • Multi-ring aroraatics typically absorb 10 to 200 times more strongly than single-ring aromaties, AlkyL-substitutkm also affected absorption by about 20%. Therefore, it is important to use HS 5 LC to separate and identify the various species of aromaties and know how efficiently they absorb. J0069J Five classes of aromatic compounds were identified.
  • alkyl-cyclohexylbeiizene molecules in base oils exhibit a distinct peak absorbance at 272 arn that corresponds to the same ( ' forbidden) transition ihat uns ⁇ bstituted tetrahn model compounds do at 268 nm.
  • concentration of aik_yl-cyck>alkyl-i-ring aromaties m base oil samples was calculated by assuming that its molar absorptivity response factor at 272 nm was approximately equal to tettalin's molar absorptivity at 268 nm, calculated from Beer's law plots.
  • Weight percent concentration's of aromaties were calculated by assuming that the average molecular weight for each aromatic class was approximately equal to the average molecular weight for the whole base oil sample, [0071]
  • This calibration method was further improved by isolating the i-ri.og aromaties directly from the base oils via exhaustive HPLC chromatography. Calibrating directly with these aromaties eliminated the assumptions and uncertainties associated with the mode! compounds, As expected, the isolated aromatic sample had a lower response factor than the model compound because it was more highly substituted [00721 More specifically, to accurately calibrate the HPLC-UV method, the substituted benzene aromaties were separated from the bulk of the base oil using a Waters semi -preparative RPLC unit.
  • Ten grains of sample was diluted 1 :1 in n- h ⁇ xane and injected onto an ammo-bonded silica column, a 5 cm x 22,4 mm ID guard, followed by two 25 cm x 22.4 mm ID columns of S-- 12 micron aroino-bond ⁇ d silicas, panicles, manufactured by Raimn instruments, Emeryville, California, with ⁇ - hexane as the mobile phase at a flow rate of I8mk/.oim, Column ⁇ iuent was fractionated based on the detector response from a dual wavelength UV detector set at 2(SS nm and 295 nm.
  • Paraffins are considered more stable than cycloparaffins towards oxidation, and therefore, more desirable.
  • MonocycloparafOns are considered more stable than multicycloparaffins towards oxidation.
  • oils with these properties are Fischer- Tropsch oils with less than about 5% cyeloparaffios.
  • base oil derived from highly parafiinic wax and used as dielectric fluids, comprises a high weight percent of molecules with monoeycloparaffimc functionality and a low weight percent of molecules with rrmlticycloparaffinic functionality such that the base oil has high oxidation stability, low volatility, good miseibility with other oils, good additive solubility, and good elastomer compatibility,
  • the capillary tube was placed ai the tip of a solids probe for a mass spectrometer, aixi the probe was healed from about 4 ⁇ * € up to 500 0 C at a rate of 50" 1 C per minute, operating under vacuum at approximately I Cr 1 Ton * .
  • the mass spectrometer was scanned from rn/ ' z 40 to m/ ' z 1000 at a rate of 5 seconds pet decade. The acquired mass spectra were summed to generate one "averaged" spectrum. Each spectrum was °C corrected using a software package from PC-MassSpec,
  • the molecules with different numbers of ansatur atio ⁇ s can be comprised of cyeloparaf ⁇ his.. olefins, and aromatics. If aromatics were present in significant amounts in the base oil they would most likely be identified in the FlMS analysis as 4 ⁇ uri.satu ⁇ a lions. When olefins were present in significant amounts in the base oil they would most likely be identified in the FlMS analysis as 1- unsaturations.
  • base oil derived from highly paraffuiic wax lias a weight percent of molecules with cyeiopar&ffrnie functionality greater than 5.
  • base oil derived from highly paraffinic wax also has a high nnio of weight percent of molecules with monocycloparaffmic functional ity to weight percent of molecules with multicydop&raffimc functionality, generally greater than 5. greater than 10, greater than 15, or greater than 20.
  • base oil derived from highly paraffinic wax has a weight percent of molecules with cycioparaffinic functionality greater than the kinematic viscosity in rnnf ⁇ s multiplied by three, hi an embodiment, base oil derived from highly paraffinic wax has a kinematic viscosity at IQO 0 C between about 1.2 mirf/s and about 4,0 iiim'/s, for example between about 1.2 nmc/s and about 3.5 tam"/s, or between about 2.0 rami's and about 3,5
  • the additives for use in base oi Is Io provide power steering fluids include additives selected from ihe group consisting of viscosity index improvers, pour point depressants, detergents, dispersatsts, fkitdmng agents, friction modifiers, corrosion inhibitors, rust inhibitors, antioxidants, detergents, seal swell agents, antiwear additives, extreme pressure (EP) agents, thickeners, friction modifiers, colorants, dyes, color stabilizers, ami foam agents, corrosion inhibitors, rust inhibitors, seal swell agents, metal deactivators, deodorizers, de.mulsi.Oets > anti- squeal agents, and mixtures thereof.
  • additives selected from ihe group consisting of viscosity index improvers, pour point depressants, detergents, dispersatsts, fkitdmng agents, friction modifiers, corrosion inhibitors, rust inhibitors, antioxidants, detergents, seal swell agents, antiwear additives, extreme pressure (EP
  • the additives can be in the form of a lubricant additive package, which comprises several additives to provide a power steering fluid with desirable properties.
  • Lubricant additive packages for use in base oils to provide power steering fluids include lubricant additive packages selected from the group consisting of viscosity index improvers, pour point depressants, detergent-inhibitor (Dl) additive packages, and mixtures thereof ⁇ ⁇ Yi ⁇ osi 1 y ⁇ jlldex improvers
  • Viscosity index improvers modify the vLscometrie characteristics of luhrieants by reducing the rate of thinning with increasing temperature and the rate of thickening with low temperatures. Viscosity index improvers thereby provide enhanced performance at low and high temperatures. Io many applications, viscosity index improvers are used in combination with detergent -inhibitor additive packages to provide a. power steering fluid,
  • the viscosity index improvers can be selected from the- group consisting of olefin copolymers, co-polymers of ethylene and propylene, poiyalkylaerylates., potyalkylmethacryiafes, styrene esters, poiyisobutylene.
  • hydrogenated styrerse-Lsoprene copolymers star polymers, including those having tetrabiock copolymer arms of hydrogenated pojyisoprene-poiybuiadiene- poiyisoprene with a block of polystyrene, or hydrogenated asymmetric radial polymers having molecules with a core composed of the remnant of a tetravaknt silicon coupling agent, a plurality of rubbery arms comprising polymerized d ⁇ ene units and a block copolymer arm having at least one polymerized di ⁇ n ⁇ block and a polymerized monov ⁇ ny ⁇ aromatic compound block, hydroge ⁇ ated styren ⁇ - buiadienes, arsd mixtures thereof.
  • the viscosity index improver is an ethyie ⁇ e/a -olefin interpolymer as described in WO 2006/102146 A2 > wherein the ethyleue/a ⁇ oiefm interpolymer is a block copolymer having at least a hard block and at least a soft block.
  • the soft block comprises a higher amount of comon.oin.ers $ha ⁇ the hard block
  • the viscosity index .improver is an acrylic acid ester polymer comprising a copolymer derived from a first acrylic acid ester monomer having from about 1 io about 4 carbon atoms, a second acrylic acid ester monomer having from about 12 to about 14 carbon atoms, and a third acrylic acid ester monomer having from about 16 to about 20 carbon atoms, as described ⁇ U S. Patent Application Publication No, 2006/0252660 AL wherein the copolymer has weight average molecular weight of 20.OCO-I OO 5 OOO daitons and contains 1 weight % or less of u.nreacted monomer.
  • pour point depressants used in power steering fluids modify the wax crystal morphology such as to reduce interlocking of the wax crystals with consequent viscosity increase or geitechnische.
  • pour point depressants are alkylated naphthalene and phenolic polymers, polymethacrylaies, alkylated bicyclic aromatics.
  • mafeate/fumarate copolymer esters methacry late-vinyl pyrrolidone copolymers, styrene esters, polyf ⁇ merates, vinyl aeetat ⁇ -furaarale co-polymers, dialkyl esters of ' phthaiate acid, ethylene vinyl acetate e ⁇ rnpoiyers f and other m ⁇ ed hydrocarbon polymers from commercial additive suppliers such as UJ BRIZOL 5 the ETHYL Corporation, or ROMMAX, a Division of Degussa. ffi- Piiyii ⁇ >i?>l . BMudl]£ . B . klA4 iloraponent
  • pour point reducing blend component refers to an isome.rized waxy product with relatively high molecular weights and a specified degree of alky I branching in the molecule, such that it reduces the pour point of lubricating base oil blends containing it Examples of a pour point reducing blend component are disclosed in U.S. Patent Nos, 6,350,577 and 7.053.254,. and U.S. Patent. Application Publication No.
  • a pour point reducing blend component can be: I t an isor ⁇ erized Fischer- ' i ropsch derived bottoms product; 2) a bottoms product prepared from an isomerued highly waxy mineral oil, or 3) an isomerized oil having a. kinematic viscosity at 100 0 C of at least about S mnvVs made from polyethylene plastic,
  • the pour point reducing blend component is an isonierized Fischer-Tropsch derived vacuum distillation bottoms product having an average molecular weight, between 600 and 1 100 and an average degree of branching in the molecules between 6,5 and 10 alkyi branches per 100 carbon atoms.
  • the higher molecular weight, hydrocarbons are more effective as poor point reducing blend components than the lower molecular weight hydrocarbons.
  • a higher cut point in a vacuum distillation unit which results in a higher boiling bottoms material is used to prepare the pour point reducing blend component,
  • the higher cut point also has the advantage of resulting in a higher yield of the distillate base oil fractions,
  • the pour point reducing blend component is an isoraenzed .Hseher-Tropsch derived vacuum uisrillation bottoms product having a pour point that is at least 3*C higher than the pour point of the distillate base oil it is blended with.
  • the 10 percent poini of the boiling range of the pour point reducing blend component that is a vacuum distillation bottoms product is between about 850-1050'"'F (454-565 0 C).
  • the pour point reducing blend component is derived from either Fischer-Tropsch or petroleum products, having a boiling range above 950 0 F ( S I O 0 C K and contains at least 50 percent by weight of paraffins, hi yet another embodiment the pour point reducing blend component has a boiling range above 1050° F C565°C ⁇ .
  • the isomerized bottoms material is solvent dewaxed prior to being used as a pour point reducing blend component.
  • the waxy product further separated during solvent dewaxing from the pom point reducing blend component were found to display excellent improved pour point depressing properties compared to the oily product recovered after the solvent dewaxing.
  • the pour point reducing blend component is an iaomcriz ⁇ d oil having a kinematic viscosity at 100 0 C of at. least about 8 ram'/s made from polyethylene plastic.
  • the pour point reducing blend component is made -from waste plastic
  • the pour point reducing blend component is made from steps comprising pyrolysis of polyethylene plastic, separating out a heavy fraction, hydrotreati ⁇ g the heavy fraction, catalytic isomerrang the hydrotreated heavy fraction, and collecting the pour point reducing blend co.mpo.nent having a kinematic viscosity at 100 0 C of at least about 8 mm " /s
  • the pour point reducing blend component derived from polyethylene plastic and has ⁇ boiling range above K)SO 0 F (565 0 G')., or even has a boiling range above 12OD 0 F (640 0 C).
  • the pour point reducing blend component has an average degree of branching in. the molecules -within the range of from 6.5 to 10 aikyi branches per 100 carbon atoms, hi another embodiment, the poirr point reducing blend component has an average molecular weight between 600-1 100. (n a third embodiment it has an average molecular weight between 700- 1000, in.
  • the pour point reducing blend component has a kinematic viscosity at 100 rj C of 8-30 mm7s- with the 10% point of the boiling range of the bottoms falling between about 850-1050"F
  • the pour point reducing bien ⁇ component has a kinematic viscosity at 100°C of 1 5-20 ranrv's and a pour point of ⁇ 8 to ⁇ 12°C,
  • the pour point reducing blend component is an isoraenze ⁇ on having a kinematic viscosity at 100 0 C of at least about 8 ninrVs made from polyethylene plastic.
  • the pour point reducing bknd component is made from waste piasiie.
  • pour point reducing blond component is made from stops comprising pyrolysis of polyethylene plastic separating out a heavy fraction, ⁇ ydrotreatmg the heavy fraction, catalytic iso.rnerkd.ng the hydrotreated heavy .traction, and collecting the pour point reducing blend component having a kinematic viscosity at iOO ':' C of at least about 8 mni'/s hi a third embodiment, the pour point reducing blend component derived from polyethylene plastic has a boiling range above IUS(PP (565°C). or even a boiling range above 120(PF (649 ⁇ C).
  • Detergent-inhibitor additive packages serve to suspend oil contaminants, as well as to prevent oxidation of the power steering fluids with the resultant formation of varnish and sludge deposits.
  • the detergent-inhibitor additive package useful in power steering fluids contains one or more conventional additives selected from the group consisting of dispersants, fl ⁇ idizhig agents, friction modifiers, corrosion inhibitors, rust inhibitors, antioxidants, detergents, seal swell agents, extreme pressure additives, a ⁇ tiwear additives., deodorizers, antifoarn agents, dcmulsil ⁇ erSj colorants, and color stabilizers.
  • the detergent-inhibitor additive package is present in an amount of from 2 to 2$ weight percent, based on the total weight of the power steering fluid composition.
  • Detergent-inhibitor additive packages are readily available from additive suppliers such as 1,UBRIZOL,, ETHYL., Oronite, and ⁇ NF ⁇ NEIJM A number of detergent- inhibitor additives are described i ⁇ EP 0 978 555 Al , V . Dispersants
  • Dispersarsts are used i ⁇ power steering fluids to disperse wear debris and products of lubricant degradation within the equipment being lubricated ⁇ i.e.. power steering equipment ⁇ .
  • the ashless dispersants commonly used contain a Lipophilic hydrocarbon group and a polar functional hydrophilic group.
  • the polar functional group can be of the class of c&rboxylat ⁇ , ester, amine, amide, inline. imide. hydroxy]., ether, epoxide, phosphorus, ester carboxyl, anhydride, or nkriie
  • the lipophilic group can be ⁇ hgomeric or polymeric m nature, usually from 70 to 200 carbon atoms to ensure good oil solubility.
  • Hydrocarbon polymers treated with various reagents to introduce polar functions include products prepared by treating polyolefms such as pojyisobut ⁇ rse first, with maleic anhydride, or phosphorus sulfide or chloride, or by thermal treatment, and then with reagents such as polyamine, amine, ethylene oxide, etc.
  • the ones typically used in power steering fluids include N-substitu ⁇ ed polyisobute ⁇ yl suecrnimides and succinates, alkyl rnethacryiate- vinyl pyrrolidinone copolymers, alkyl methacrylaie-dialkylaminoethyl methacrylatc copolymers, alkylmetbacryiate-polyethylene glycol methacryiate copolymers, and polysteararrsides.
  • Some oil-based dispersants that are used in power steering fluids include dispersants from the chemical classes of alkylsuccimmide, succinate esters, high molecular weight amines, and IVfannieh base and phosphoric acid derivatives.
  • Some specific examples are polyisobute ⁇ yl succirjimide-poiyetbylencpoiyaffiine, polyisobuteny! succinic ester, polyisobutenyl hydroxybenxyl-polyethykucpolyarui ⁇ e, bis-liydtoxypropyi phosphurate.
  • C ' ornmercial dispersants suitable for power steering fluid are for example, [,UBRIZOL 890 (an ashless PlB succinimide), LUBRiZOL 6420 fa high molecular weight PlB suceimniide), and KTHYL, H(THC 646 (a ram-bor ⁇ nated PIB succinimide).
  • the dispersant can be combined with other additives used in the lubricant industry to form an additive package for power steering fluid, e.g., LUBR1ZOL 9677MX. and the whole additive package can be used as the dispersing agent.
  • a surfactant or a mixture of surfactams with low HLB value (typically less than or equal to 8).
  • nordonic or a mixture of nonkmies and ionics
  • the dispersants selected should be soluble or dispersible m the ik ⁇ d medium or additive ⁇ iiuem oil.
  • the dispersant can be in a range of up from 0.01 to 30 percent and ail sub-ranges therebetween, for example m a range of from between. 0,5 percent to 20 percent, a range of .from between ) to 1 5 percent, or in a range of from between 2 to 13 percent as active ingredient in the power steering fluid.
  • Floidizing agents are sometimes used in power steering fluids.
  • Suitable iluidizing agents include oil-soluble diesters.
  • diesters include the adipates, azelates., and sehacates ⁇ f €g4-Y ? alkanois (or mixtures thereof), and the. phtliaiates of C 4 -Cn alkanois (or mixtures thereof).
  • Mixtures of two or more different types of diesters e.g., dialkyl adipates and diaikyi azelates, etc.
  • examples of such materials include the ivoctyi, 2-ethylhexyl, isodecyi, and tridecyl diesters of adipic acid.
  • esters which are used as ilaklizing agents in power steering fluids are polyol esters such as HMHRY 2918, 2.939 and 2995 esters from the EMERY Group of Eleokel Corporation and MATCOL 2926. 2970 and 2999.
  • thickeners besides viscosity index improvers, which can be used in the power steering fluid include: acrylic polymers such a? polyacrylic acid and sodium high-rao Secular- weight polymers of ethylene oxide such as Poiyox WSR from Union Carbide, cellulose compounds such as earh ⁇ xymethylcellulose, polyvinyl alcohol (PVA), polyvinyl pyrrolido ⁇ e (PYP), xantban gums and guar gums, polysaccharides, alkanolaraides, amine salts of polyamide such as DISPARLON AQ series from King Industries, hydrophobicaiiy modified ethylene oxide urethane (e.g.
  • silicates, and fillers such as mica, silicas, cellulose, wood flour, clays (including organociays) and clays, and resin polymers such as polyvinyl butyral resins, polyuref-hane resins, acrylic resins and epoxy resins.
  • thickeners are polyis ⁇ hutyiene, high ⁇ iolecuiar weight complex ⁇ sier, butyl rubber, olefin copolymers, styrene-diene polymer, polyinethacrylate.. styr ⁇ n ⁇ -ester, ami ulira high viscosity PAO.
  • An example of a high molecular weight complex ester is Priolube* 3986.
  • an ultra high viscosity PAO can also be used in the formulation.
  • an "ultra high viscosity PAO ' ' has a kinematic viscosity between about 150 and LOOO mra'/s or higher at 100" v C. VIII , Frictj on . Modifiers
  • Friction modifiers are optionally used in power steering fluids.
  • Suitable friction modifiers include such com pounds as aliphatic amines or ethoxylated aliphatic amines, aliphatic fatty acid amides, aliphatic carboxylic acids, aliphatic carboxylic esters, aliphatic carboxylic ester-amides., aliphatic phosphonai.es, aliphatic phosphates, aliphatic thiophosphonates, aliphatic ihiophosphates, or mixtures thereof.
  • the aliphatic group typically contains at leas! about eight carbon atoms so as to render the compound, suitably oil soluble
  • aliphatic substituted succiniraid.es formed by reacting one or more aliphatic succinic acids or anhydrides with ammonia
  • One group of friction modifiers is comprised of the N-aliphatic hydrocarbyl-substiiuted diethanol amines in which the N-aliphatic hydrocarbyl- substituent is at least one straight chain aliphatic bydrocarbyi group free of acetyl eni c unsaturation and having in the range ofaboi.it 14 to about 20 carbon atoms.
  • Another group of friction modifiers is comprised of esters of fatty acids, for example C EN W AXTM TGA-185 and glycerol esters of selected fatty acids such as UNIF LEXTM 1803, both made by Arizona Chemical
  • Other fatty acids used as friction .modifiers are mono-oleates such as glycerol mono-oleate, peruaerythruo! mono-oleate. and sorbitan. mono-oleate sold under the tm ⁇ mame of RADI ASURFTM by OLEON.
  • Friction modifiers will sometimes include a combination of at least one K-aiipbauc hyd.rocarbyl-substiuued diethanoi amine ⁇ U at least one N-aliphatic h ydrocarbyl -substituted triraetbyi ⁇ ne diamine in which the N-aiiphatic hydrocarbyl- substitue ⁇ t is at least one straight chain aliphatic hydrocarbyl group tree of aeetv'lenk ui ⁇ saturation and having in the ranue of about 14 to about 20 carbon atoms. Further details concerning this friction modifier combination are set forth in U.S. Patent Nos, 5,372,735 ami 5,441,656.
  • Another example of a mixture of friction modifiers is based on the combination of (i) at bast one di(hydroxyalkyl) aliphatic tertiary amine in which the hydroxyalky! gxoups, being the same or different, each contain from 2 to about 4 carbon atoms, and irs which the aliphatic group is an acyclic hydrocarby) group containing from about 10 to about 25 carbon atoms, and (ii) at least one hydroxyaikyl aliphatic imidazoline in which the hydroxyalkyl group contains from 2 to about 4 carbon atoms, and in which the aliphatic group is an acyclic hydrocarbyl group containing from about 10 to about 25 carbon atoms.
  • Another class of friction modifiers that, is sometimes used in power steering fluids include compounds of the formula: in which Z is a group RI R.2CH-, in which R i and R2 are each independently straight- or branehed-ehain hydrocarbon groups containing from i to 34 carbon atoms and the total number of carbon atoms in the groups Rl and R2 is from i 1 to 35.
  • the radical Z is, for example, 1 - methyl pemadeeyl, 1 -propyl trideeeuyl.
  • Corrosion inhibitors are another class of additives suitable for inclusion in power steering fluids. Such compounds include thiazoies, tnazoles and thiacliazoies..
  • Examples of such compounds include benzotriazoie, tolyitriazoie, octyltrjazoie, ⁇ ecyitriazol ⁇ , dodecyltiiazole, 2 ⁇ mercapto henzothiazol ⁇ , 2,5- dimercapi53"l s 3,44hiadiazole, 2 ⁇ raercaph3--5 ⁇ hydroearbyldiio-l,3.4 ⁇ thiadu5zok-s, 2- mercapto-5- hydrocai'byidithio-l ,3v4-thiadia?.oles, 2,54>is(hydrocarbylthi ⁇ )-4 ,3,4- ⁇ thiadiazoies.
  • Corrosion inhibitors of these types that are available on the open market include Cobratec TT- 100 and HITEC* 314 additive and HFfEC* 4313 additive (ETHYL, Petroleum Additives, Inc.).
  • Rust inhibitors comprise another type of inhibitor additive. Some rust inhibitors are also corrosion inhibitors. Examples of rust inhibitors useful in power steering fluids are monocarboxylie acids and poly carboxy lie acids, Examples of suitable monocarboxylic acids are oclanoic ae ⁇ l decanoic actd and dodecanoic acid. Suitable p ⁇ iyearhoxylic acids include di.mer and trirner adds such as are produced from such acids as tail oil fatty acids, cdeie acid, lsnoleic acid, or the like. Products of this type are currently available from various commercial sources, such as.
  • rust inhibitor for use Lo power steering fluids is comprised of the alkenyl succinic acid and alkenyl succinic anhydride oo ⁇ osion inhibitors such, as, for example, tetrapropeirylsuccmie acid, tetrapropemisuceinie anhydride, teiradeeeivylsuecioie acid, tetr adeeenylsuecinic anhydride , hexadecemisuee; nic acid, hexadecenylsucclnic anhydride, and the like.
  • rust inhibitor is a msi .inhibitor comprising a solubility improver having an aniline point less than 100°C; a mixture of amine phosphates; mid an alkenyl succinic compound selected from the group consisting of an acid half ester, an anhydride, an acid, and .mixtures thereof as taught m IJ. S, Patent Application No. 11/257,900, filed on October 25, 2005.
  • Suitable rust or corrosion inhibitors include ether amines; acid phosphates; amines: poiyethoxyiated compounds such as ethoxylateci amines, ethoxylated phenols, and ethoxylated alcohols; imidazolines; amrnosuccmic acids or derivatives thereof, and She like,
  • Suitable antioxidants include phenolic antioxidants, aromatic amine antioxidants, sulfated phenolic antioxidants, hindered phenolic antioxidants, molybdenum containing compounds, zinc dialkyldltbiophosphat.es, and organic phosphites., among others. Mixtures of different types of antioxidants are often used. Examples of phenolic antioxidants include kmoi derived hindered phenols, 2.6-di- tert-butylphenoL liquid mixtures of tertiary butyiated phenols, r ⁇ ethylpheoo!
  • 4-tsopropylaminodiphenyl amine, phenyl— naphtbyl amine, phenyl-naphihyl amine, styrersated diphenylamiii ⁇ , and ⁇ ng-alkylated diphenylamines serve as examples of aromatic amine antioxidants.
  • the antioxidant is a catalytic antioxidant comprising one or more oil soluble organo metallic corapound(s) and/or orga ⁇ o metallic coordination complexes such as metal(s) or metal cation(s) having m ⁇ re than one uxiuation state above the ground state compiexed, bonded or associated with two or more anions, one or more bi ⁇ entate or tridentate ligands and/or two or more anions and ligand(s), as described in U.S. Patent Application Publication No. 2006/0258549 A l . X! 1 ⁇ [Mergents
  • seal swell agents useful in power steering fluids are described in U.S. Patent Application Publication N ⁇ s. 2003/0 I l 9682 A l and 2007/0057226 A 1 .
  • seal swell agents are aryl esters, long chain alkyi ether, alky! esters, vegetable based esters, sebacat ⁇ esters, sulfhlanes, .substituted suifoiane. other suiibia ⁇ e derivatives, pbeniues, adipates. glyceryl iri(acet ⁇ xysteaiate), epoxidized soybean oil.
  • epoxsdized linseed oil N n -butyl benzene sulfonamide, aliphatic polyuretha ⁇ e, polycsier glutarate, triethy ⁇ ene glycol caprat.e/eapry!ate s dialkyl diester glutarat ⁇ , monora ⁇ c, polymer, and ep ⁇ xy plastickers.
  • phthalate pbustieizsrs such as dioctyl phthalate, dinonly phf.ha.late or dihexylpthaiate. or oxygen-, sulfur-, or nitiOgen-coistaining polyfunctions!
  • piasticizers which can be substituted for and/or used with the above plasticims including glycerine, polyethylene glycol, dibutyl pbthalate, and 2,2,4-trime ⁇ iiy!-] niOBOisobvstyrate, and diiso ⁇ o ⁇ yi phthalate ail o.f which are soluble in a solvent carrier.
  • Other seal swelling agents such, as LUBRJZOL 730 can also be used, X S V , Aniiwear ; . and/or . Extr erne fte ⁇ s ⁇ sie Addjt i ves
  • sulfur-containing ami wear and/or extreme pressure additives can be used hi power steering fluids.
  • Examples include dihydrocarbyi polysuliides; sulfurized olefins; sulfurked fatty acid esters of both natural and synthetic origins; trithioaes; suLfurized thienyl derivatives; sulfurixed terpenes: sulfiirized oligomers of CrQ r ⁇ onoolefins, and sulfur ized Dieis-Ald ⁇ adducb huch as those disclosed in U.
  • Specific examples include ⁇ uifurized polyisobutene, suifurized isob ⁇ tylene, suifu ⁇ xed diisobutylene. sulf ⁇ rized triisobutyleue, dieyclohexyl polysulilde, diphenyl poiysuH ⁇ de, dihetrzyl polysulfide, dinonyl potysuLtkie, and mixtures of di-tert-b ⁇ cyi poiysuH ⁇ de such as mixtures of di- tert-butyl trisidfide, di-tert- butyl tetrasislfide and di4ert-butyl pe ⁇ tasufftde, among others.
  • Combinations of such categories of sulfur-containing antiwear and/or extreme pressure agents can also be used, such as a combination of sulfumed isob ⁇ tylene and di- ⁇ ert- butyl trisulfide, a co.ofbinatio ⁇ of sulforized isobutylene and dinonyl trisu ⁇ flde, a combination of sulfuri zed tall oil and dibe.azyl poiys ⁇ lfule, [00118 ⁇ hi the context of this disclosure a component which contains both phosphorus and sulfur in its chemical structure is deemed a phfxsphorus ⁇ cont.aining at ⁇ iwear and/or extreme pressme agent rather than a sulfur-containing a ⁇ tiwear aucl-'or extreme pressure agent.
  • Use can be made of a wide variety of phosphorus-containing oil- soluble an ⁇ vvear and/or extreme pressure additives such as the oil-soluble organic phosphates, organic phosphites, organic phosphorates, organic pho ⁇ phonites, etc., and their sulfur analogs.
  • phosphorus-containing antiwear and/or extreme pressure additives that can be used in power steering fluids include those compounds' that corstam both phosphorus and nitrogen
  • Phosphorus-containing oil- soluble arstiwear and/or extreme pressure additives useful in power steering fluids include those compounds taught in IKS, Patent Nos. 5,464,549, 5,500, 140, and 5,573,696.
  • One such type of phosphorus- and o ⁇ rogeiv containing ami wear and/or extreme pressure additives which can be used in power steering iiiuds are the phosphorus- and nitrogen-containing compositions of the type described in GB 1 ,009,913, GB 1 ,009,914, U.S. Patent No. 3,197,405 and/or U.S. Patent No. 3,197,496.
  • compositions are formed by forming an acidic intermediate by the reaction of a hydroxy-substituted t ⁇ ester of a phosphorotluok acid with an inorganic phosphorus acid, phosphorus oxide or phosphorus halide, and neutralizing a substantial portion of said acidic intermediate with an amine or iiydroxy-substituted amine.
  • phosphorus- and nitrogen-containing a ⁇ thvear and/or extreme pressure additive that can be used in power steering fluids include the amine salts of hydroxy-substituted phosphetanes or the amine salts of hydroxy -substituted thiophosphetanes and the amine salts of partial esters of phosphoric and thiophosphoric acids.
  • Antifoam agents work by destabilizing the liquid film that surrounds entrained air bubbles. To be effective they must spread effectively at the air/liquid interlace. According to iheory, the amifbam ageni will spread if the value of the spreading coefficient, S, is positive, S is defined by the following equation:
  • F J is the surface tension of the foamy liquid
  • P is the surface tension of the an ⁇ foaxo agent
  • P ! -" is ⁇ ie interfaciai tension between them.
  • Surface tension and mteitaeial tensions are measured using a ring type tensiomeCer by ASlM D 1331-89 (Reapproved 2001 ), "Standard Test Methods fo ⁇ Surface and hiterfacial Tension of Solutions of Surface- Active Agents".
  • P ! is the surface of the power steering fluid prior to the addition of anlifoam agent.
  • antifoam agents are antifbam agents that, when blended into the power steering fluid will exhibit spreading coefficients of at least 2 mN/ ' m at both 24 C 'C aid 93.5 0 C.
  • Various types of antifoam agents are taught in U.S. Pended No. 6,090,758.
  • the antifoam agents should not significantly increase die air release ⁇ me of the power steering fluid
  • suitable aotifoam agents are high molecular weight polydiinethyi siloxanc, a type of silicone antifoam agent, acryiate antifoam agents (as they are less likely to adversely effect air release properties compared to lower molecular weight silicone antifoarn agents), polydimethylsiioxan.es and polyethylene glycol ethers and esters, XVI, Cj ⁇ lorantg/Dygs
  • Colorants or dyes are used to impart color or to fluoresce under particular types of light. Fluorescent dyes facilitate leak detection. Colored oils help distinguish between different products. Examples of these colorants or dyes are anthraquhiones, azo compounds, ⁇ .ri phenyl- in ethane-, perylene dye, naphthalimide dye, and mixtures thereof. Particular types of iluorescent dyes are taught in U.S. Patent No, 6,165,384, XVH. Dihient OiI
  • Diluent oil is often iused in the different types of additive packages to effectively suspend or dissolve the additives in a liquid medium.
  • the maximum amount of diluent oil in all of the additive packages used to make the power steering fluid should he within 0 to 40 volume %.
  • the diluent, oil is an extra light hydrocarbon liquid derived from highly paraflinic wax, described in U.S. Patent Application Publication No. 2006/0201852 Al, wherein the diluent oil has a viscosity of beiwyen about 1.0 mnr/s and. about ⁇ .S rnm ' V ' s at I QO 0 C? and a Noack volatility of less than 50 weight %, and also having greater than 3 weight % molecules with cyc ⁇ oparaftlnic nractkmaiUy and less than 0.30 weight percent aromatics.
  • IMoack ' Volatility Factor 160 - 40(K.inematic Viscosity at 100 0 C), (2) .bxamps ⁇ 2: houation ⁇ j )
  • the three Fiseher-Tropseh derived base oils were all distillate tractions made by hydroisomeriza ⁇ on devvaxing a hydrotreated ( ⁇ o- based Fischer- Tropseh wax in a constitus of two reactors, hydro finishing die effluent in a single reactor., and vacuum distilling the product into different grades of base oil.
  • Ail three of these Fischer- Tropseh derived base oils had very low aromaties and olefm contents, and had very good oxidation stabilities. Additionally, all three of them had very low Noack volatilities. Note thai only the FT-A had a wt% Noack Volatility less than an amount defined by the equation:
  • Noack Volatility Factor Noack Volatility Factor ::;: (900 x (Kinematic Viscosity ai 100°C) 'i 8 5 - 1 5. (3) The difference between the vvi.% Noack volatility of the light base oil fraction VT-A and the Noack Volatility Factor by Equation (3) of FT-A was greater than 0.5, FT-A also had extremely good oxidation stability and a viscosity index greater than: 28 x ln(Kinematic Viscosity at I CXPC) + 95.
  • catalyst w a series of three reactors at a temperature of 600-700 11 F, about 1 LHSV feed rate, less than 800 psig pressure, and about 4 to about 20 MSCF/bbi hydrogen flow rate.
  • the product was hydrofraished over a Pd/Siiica Alumina hydroimishing catalyst in a series of two hydrof ⁇ mshing reactors at a total pressure greater than 700 psig, a temperature of about 400 to about 600 0 F, aboui 1 LFI S V feed rate, and about 4 to about 20 MSCF/bbl hydrogen flow rate.
  • Noack Volatility Factor ::: - (900 x (Kinematic Viscosity at 100' "1 C) "2 8 ) - 15. 0)
  • the difference between the wt% Noack volatilities of the light base oil fractions FT- D and FT-E and their Noack Volatility Factors by Equation (3) were greater than 5. They both had exceptionally good oxidation stabilities, low pour points, and high VIs.
  • Base Oil 1 unlike the Comparative Base OiL also has a Noack volatility less than a Noack Volatility Factor calculated by either of the foi lowing equations: 160 - 40(Kinernatic Viscosity at 10OO. (2)
  • Equation (3) provides a lower Noack Volatility Factor than does Equation (2).
  • the kinematic viscosity of Base Oil 1 is 2.18 nmrVs
  • Equation (3) does not provide a lower Noack Volatility Factor (86,52) than does Equation (2) ⁇ 72.8 ⁇ for Base Oil 1
  • die kinematic viscosity of the Comparative Base Oil is 2.981 mnr/s
  • Equation (3) does provide a lower Noack Volatility Factor (27.27) than does Equation (2) (40,76 . ) for the Comparative Base Oil.
  • the T 1 GA Noack Volatility of the Comparative Base Oil, 48 vvt% is greater than either 27,27 or 40.76, while the TG ⁇ Noack Volatility of Base Oil 1 , 67.37 wt%, is less than either 86.52 or 72.8.
  • Fonura Nexbas ⁇ 3043 is a conventional API Group I II base oil.
  • the total 1 -to 6- umatur&tions by FiMS for Fortur ⁇ Nexbase 3043 is greater than. 55 weight %, and the ratio of moie ⁇ sles with monocycloparaffmic functionality to molecules wiih ⁇ iulticycioparaf ⁇ nic functionality is less than 2.0.
  • ⁇ U of the publications, patents and patent applications cited herein are herein incorporated by reference in their entirety to the same extent as if the disclosure of each individual publication, patent application or patent was specifically and individually indicated to be incorporated by reference in its entirety, [00140] Many modifications of the exemplary embodiments disclosed herein will readily occur to those of skill in the art. Accordingly, the present disclosi ⁇ e is to be construed as including all structure and methods that fail within the scope of the appended claims.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Lubricants (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)

Abstract

Provided are power steering fluids made from a waxy feed and with improved low temperature properties, such as, for example, a viscosity index of greater than 290 and a Brookfield Viscosity at -40°C of less than 1900 mPa s. In an embodiment, the power steering fluid comprises greater than 50 weight % base oil, viscosity index improver, and less than about 1.0 weight % pour point depressant.

Description

POWER STEERING FLUID
FIELD OF ART
[000 J J Provided are power steering fluids with improved low temperature properties and high viscosity index, and more specifically* power steering fluids made from a base oil having consecutive numbers of carbon atoms and having a very high viscosity index.
BACKGROUND
{0002 j Power steering fluids are an integral part of all power steering systems. Power steering fluid is used in about 80 to 90% of all vehicles in North America and Japan, as well as increasing numbers of vehicles in other parts of the world. Original Equipment Manufacturers have stringent specifications for power steering fluids. Requirements include high oxidation stability, high viscosity index, and compatibility with seals and hoses, In the past, power steering fluids used blends of naphthenic and solvent neutral base oils. Newer power steering fluids have been formulated with blends of naphthenic, solvent neutral, and hydrocracked base stocks. The hydrocracked base oils used in power steering fluids have had saturates contents of about 90 to about 99 mass %. Power steering fluids with improved viscosity index and lower Brooktield viscosity are needed.
S(JMMARY
{0003] Provided is a power steering ϊimd comprising greater than 50 weight
% base oil and viscosity index improver and having a viscosity index of greater than 2% and a Brookfield Viscosity at. -400C of less than 1900 mPa-s, The base oil has consecutive numbers of carbon atoms and has a viscosity index greater than a viscosity index calculated by the following equation;
28 x in(Kberoatk Viscosity at UHYT) + 101 ;
10004J Also provided is a process for producing a power steering fluid comprising greater than 50 weight % base oil and having a viscosity index of greater than 290 and a BrookOeld Viscosity at -4O0C of less than 1900 raPa-s, the process comprising obtaining a base oil and blending the base oil with viscosity index improver to form the power steering fluid. The base oil has consecutive numbers of carbon atoms: a kinematic viscosity at 1000C of kss than about 4 mm VU; and a Noack volatility less than a Noack Volatility Factor calculated by the following equation:
160 - 40(Ki.πematJc Viscosity at ϊ CO0C).
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWING
[0005 j FIG. 1 is a graph of the Viscosity Index Factor calculated by the following equ ati on:
Viscosity hidex Factor :::' 28 x In(Ki siematic Viscosity at lOU'-Q + 10! . (1 }
[0006] FIG. 2 is a graph of the Noaek Volatility Factor calculated by the fol lowing equations;
Noack Volatility Factor ::: 160 - 40(Kinematic Viscosity at 100'''C); (.2)
Noack Volatility Factor :;; (90C) x (Kinematic Viscosity at IϋOf-'C)*2 s) - 1.5. (3)
DETAILE D DESCRIPTION
C0007] In an embodiment, the base oil of the power steering fluid has a kinematic viscosity at 1000C between about 1 .2 mrø~/s and leas than about 4.0 mnr/s. a high viscosity index, low Cold Cranking Simulator (CCS) viscosity (less than 1500 mPa-s at -35X), and in an embodiment, cycioparaffm composition of greater than 5 weight % total molecules with cycloparaffmic functionality, and a ratio of molecules with monocycSoparaffmic functionality to molecules with rmilticyetoparafϊmic functionality of greater than 2.1 , such as greater than 5. greater than 10, greater than 15, or greater than 20.
[0008] Poiyalphaolefin (PAO) oils are an oligomerization product of even carbon numbered linear alpha olefins, typically 1-deceπe, The PAO oil molecules, therefore., comprise a mixture of even carbon numbered hydrocarbon molecules, differing from each other in the .number of carbon atoms, by multiple* of the number of carbon atoms in the linear alpha olefin starting monomer. Even if a .mixture of hnear alpha olefin monomers having even numbers of carbon atoms {e.g , deceiie and dodecene) were oiigornerized to form a heavy lubricant base stock oil, the number of carbon atoms hi the resulting hydrocarbon molecules would still have even numbers of carbon atoms. This is different from the mixture of consecutive numbers of carbon atoms hi the hydrocarbon molecules of the base oil of the power steering fluid disclosed herein, which comprise hydrocarbon molecules having both even and odd numbers of carbon atoms and which differ from each other by consecutive numbers of carbon atoms (e.g., L 2, 3, 4, 5, 6. 7 and more carbon atoms),
[0009 J The phrase "consecutive numbers of carbon atoms'' means that the base oii has a distribution of hydrocarbon molecules over a range of carbon numbers, with every number of carbon numbers in-between. For example, the base oil may have hydrocarbon molecules ranging from C 22 to Cj6 or from €30 to C«o with every carbon number in-between. The hydrocarbon molecules of die base oil of the power steering fluid differ from each other by consecutive numbers of carbon atoms, as a consequence of the waxy feed also having sequential numbers of carbon atoms. For example, in the Fischet-Tropsch hydrocarbon synthesis reaction the source of carbon atoms is CO and the hydrocarbon molecules are built op one carbon atom at a time. Petroleum-derived waxy feeds also have sequential numbers of carbon numbers, in contrast to an oil baaed on PAO, the molecules of the base oil of the power steering fluid disclosed herein have a more linear structure, comprising a relatively long backbone with short branches. The classic textbook description of a PAO is a star-shaped molecule, and in particular tridecane, which is illustrated as three decanε molecules attached at a centra! point While a star-shaped molecule is theoretical, nevertheless PAO molecules have fewer and longer branches than the hydrocarbon molecules that make up the base oil of the power steering fluid fOOlOJ In ail embodiment, the base oil of the power steering fluid comprises consecutive numbers of carbon atoms. The power steering fluid comprises greater than 50 weight % base oil; and viscosity index improver in an amount less than 13 weight %, or less than 12 weight %. The power steering fluid comprises between 0 and less than about 1.0 weight % pour point depressant. The power steering fluid has a Brookiieid Viscosity at -400C of less than 1900 mPa-s. The power steering fluid, in an embodiment, comprises a detergent-inhibitor additive package, tor example, 2 to 6 weight % or 5 weight % detergent- inhibitor additive package. fθOl 1 J lα an embodiment, the power steering fluids (e g. , for automobiles and light trucks) meet the requirements of a variety ul' specifications fur power steering fluids used in automotive power steering systems or are suitable for power steering fluid service fill replacement. Examples of power steering fluid specifications are; Daimler/Chrysler MS593 LF, DamiierChrysIer MS 1872, Ford M2C138-C.L Ford M2C33-F, Ford ESW-M2C12S-C & D, GM 998501Q5 Navistar TMS 68! (X and Volkswagen TL-VW-S70-26. Examples of power steering fluid part numbers are: Aeura/Tlonda Part Number 08206-9002 PE. Audi Part Number O002000, Mercedes Benz Part Number 00 989 8803, Saab Part Number 30 09 800, and Subaru Part Number K0Z09A0080.
|0012| Fischer-Tropsch derived base oils produced by catalytic
Iiydroisomerizaiioϊi have exceHent oxidatioii stability, low volatility, and high viscosity index, Fischer- Tropsch derived base oils contain greater than 95 weight % or greater than 99.0 weigh! %, or greater than 99.5 weight % saturates, which in addition distinguishes them from most hydrocracked base oils used previously m power steering fluids. Because of their good properties, Fischer- Tropsch derived base oils with viscosities between about 1.2 and about 4.0 mnf/s at I Q(PC can be blended into powei steering fluids. Fischer-Tropsch derived base oils have inherently good lubricant characteristics, due to their content of molecules with cycloparaffiriic functionality, and therefore have natural lubricity, wear resistance, solvency and seal compatibility. Fischer-Tropsch derived base oils also are fully compatible with naphtheαic and solvent neutral base oils, and when combined with oilier types of base oils make a base oil blend that is further enhanced in the aforementioned lubricant characteristics, especially, in their compatibility with the elastomers in the seals and hoses of power steering systems,
[0013 j The following terms will be used throughout the specification and
ΛVΪJ.1 have the following meanings unless otherwise indicated. (0014) The term "Fiseher-Trøpsch derived" means that the product, fraction, or feed originates liom or is produced at some stage by a Fischer-Tropseh process. [00Ϊ5J The term "petroleum derived" means that the product., fraction, or feed originates from the vapor overhead streams from distilling petroleum crude and the residual fuels that are the non-vaporizable remaining portion. A source of the petroleum derived product, fraction, or feed can be from a gas field eo.nde.rj sate. [00.16] Highly paraffinie wax means a wax .having a high content oi'n- paraffiπs, generally greater than 40 weight %, but can be greater than 50 weight %, or even greater than 75 weight %. In an. embodiment, the his>hiv paraffinie waxes also have very low levels of nitrogen and sulfur, generally less than 25 ppm total combined nitrogen and suiter, for example, less than 20 ppm. Examples of highly paraffime waxes include slack waxes, deoiled slack waxes, refined foots oils, waxy lubricant rafϋoatεs, n-paraffϊn waxes, NAO waxes, waxes produced in chemical plant processes, deoiled petroleum derived waxes, microcrystalline waxes, Fischer- Trop.sch waxes, and mixtures thereof. IB an embodiment, the pour points of the highly paraffime waxes are greater than SO0C or greater than 6O0C. [00Ϊ7] The term "derived from highly paraffinie wax" means that the product, fraction, or feed originates iroπi or is produced at some stage by from a highly paraffin! c wax.
[HiHH] Afoπiaties raeaisa any hydrocarbonaceous compounds thai contain at least one group of atoms that share an uninterrupted cloud of deioeaHzed electrons, where the number of deiocaϋzed electrons in the group of atoms corresponds to a solution to the Hneke! rule of 4a 4- 2 {e.g.. n ::: 1 for 6 electrons, etc.). Representative examples include., hut are not limited to, benzene, hiphenyl. naphthalene, and the like. (0019] Molecules with cycloparaffmic functionality mean any molecule that is, or contains as one or more substituents, a monocyclic or a fused muhieydie saturated hydrocarbon, group. The cyeloparaffinic group can be optionally substituted with one or more, such as one to three, substiuients. Representative examples include, but are no* limited to, cycl.opropyi, cydobutyL cyelohexyL. cycjopeαtyl. cycloheptyL deeahydϊonaphthaieoe, octahydropemalene, (pentadecatv 6-y 1 )cyelohexane, 3 ,7,10~trky c tahexyipentadeeane, decah ydro- 1 -(perrtadecaϊi-6- y] ^naphthalene, and the like.
{0020 j Molecules with nionocycloparafluiic functionality mean any molecule that is a monocyclic saturated hydrocarbon group of three to seven ring carbons or any molecule that is substituted with a single monocyclic saturated hydrocarbon group of three to seven ring carbons. The cycloparaffhsic group CUB be optionally substituted with one or more, such as one to three, subsiituents. Representative examples include, but are not limited to, cyclopropyL eyciobuiyi, cyciobexyl, cydoperayL cycloheptyl, {pentadecan-6-yl)cyclohexanef and the like, [W)H I Molecules with mnlticydoparai'fniic functionality mean any molecule that is a fused mυlticyclic saturated hydrocarbon ring group of two or more fused rinasL anv rnolecule that is substituted with one or more fused multicvdk saturated hydrocarbon ring groups of two υi more fused rings, or any iΩolecide that is substituted with more than one monocyclic saturated hydrocarbon group of three to seven ring carbons. The fused nuslticyclie saturated hydrocarbon ring group often is of two fused rings. The cycbparafftnic group can be optionally substituted with one or more, such as one to three, substituents. Representative examples include, but are not limited to, decahydronaphthalenε, octahydyopeutaienes 3.7,10- iricyciohexylpentadeeane, decahydro-l-(pεutadec;in-6-yl}naphtlialer\e, aiϊd the like. («0221 Brooklkid V iscosity ; ASTM D2983 -C4a is used to determine the low- shear -rate viscosity of automotive fluid lubricants at low temperatures. The iow-teroperaiare, iow~shear-raie viscosity of automatic transmission fluids, gear oils, torque and tractor fluids, and industrial and automotive hydraulic oils are frequently specified by Brook.field viscosities. [0023] Kinematic viscosity is a measurement of the resistance to flow of a fluid under gravity. Maisy base oils, power steering fluids made from them, and the correct operation of equipment depends upon the appropriate viscosity of the fluid being used. Kinematic viscosity is determined by ASTM D445-06. The results are reported in mm Vs, Iu an embodiment, Piscber-Tropsc.h derived base oil has a kinematic viscosity of between about 1 ..'• mnr/s and about 4.0 mrrr/s at 1000C. ϊn an embodiment, base oil derived from highly paraffuύc wax has a kinematic viscosity of between about 1.5 raaf/s and about 3.5 rnmV's, In an embodiment, base oil derived from high paraffmk wax has a kinematic viscosity of between about 2.0 rnnrVs and about 3.5 innf/s at HK)0C, and in ars embodiment, base oil derived from highly paralTiiiic wax has a kinematic viscosity of between about 2.0 nmvV's and about 3.0 røπvVs at 1OC)0C,
[βO24| Viscosity index (VI) is an empirical, unitk-ss number .indicating the effect of temperature change on the kinematic viscosity of the oil. Viscosity index is determined by ASTM D2270-04. in an embodiment, base oil derived from highly paraffinic wax has a viscosity index of greater than 10 L In an embodiment, base oi 1 derived from highly paraffmic wax has a viscosity index of between about 105 and about 160.
|002δ| The "Viscosity Index factor" of base oil derived from highly paraffinic. wax is an empirical number derived from kinematic viscosity of the base oil. The Viscosity Index Factor is calculated by the following equation:
Viscosity Index Factor ~ 28 x ln(Kinematk Viscosity at HJO0C) + 101 ( 1 ) wherein "In" is the logarithm function to the base fV.
Base oil derived from highly paraffinic wax can have a viscosity index greater than the Viscosity Index Factor. F(G. 1 is a graph of the Viscosity Index Factor according to the above equation. Earlier base oils derived from high]}- paraffinic wax having high viscosity indexes derived from kinematic viscosity of the base oil, such as those taught in U.S. Patent No. 7,083,713, are also usefhl m power steering fluids. However, the base oils useful in the compositions of the power steering fluid disclosed herein have viscosity indexes that are higher than the viscosity indexes of those taught in U.S. Patent No. 7,083,713. The higher viscosity index of the base oil (Viscosity index Factor) of the power steering fluid disclosed herein contributes to the improved properties (high viscosity index and low Brookfieki Viscosity) of the power steering fluid.
(0026] Pour poh.n is a measurement of the temperature at which a sample of base oil will begin to flow under carefully controlled conditions, Pour point can be determined as described in ASTM D5950-02. The results are reported in degrees Celsius. Many commercial base oils have specifications for poor point. When base oils have low pour points- the base oils are also likely to have other good low temperature properties, such as low cloud point, low cold filter plugging point, and low temperature cranking viscosity
|0027] Noack volatility is usually tested according to ASTM D58UG-Q5
Procedure B. A more convenient method for calculating Noaek volatility and one which correlates well with ASTM D58G0-Q5 is by using a theπno gravimetric analyzer (TGA) test by ASTM D6375-05, In an embodiment, base oil derived from highly paraffmie wax, has a Noack volatility of less than 100 weight %, Noack volatility of base oils generally increases as the kinematic viscosity decreases. The lower the Noack volatility, the lower the tendency of base oil and formulated oils to volatilize in service. The "Noack Volatility Factor" of base oil is an empirical number derived from the kinematic viscosity of the base oil The Noack volatility of the base oil derived from highly parøffkdc wax is veiy low. and in an embodiment, is less than m\ amount calculated by the equation:
Noack Volatility Factor ::: 160 ~ 40(Kinematic Viscosity at I DO0C), (2s
Equation (2), as provided in U.S. Patent Application Publication No. 2006/0201852 Al , provides Noack Volatility Factors between 0 and 100 for kinematic viscosities between 1.5 and 4.0 mm'Vβ, FKl 2 is a graph of ihe Noack Volatility Factor according to Equation (2). In an embodiment, the Noack volatility of the base oil derived from highly paraffmie wax is less than an amount calculated by the equation:
Noack Volatility Factor ::: (900 x (Kinematic Viscosity ai 10O0Cp^) ■- 15. (3) Equation (3), as provided in U.S. Patent Application Serial No. 1 1/613,936, provides Noack Volatility Factors between 0 and 100 for kinematic viscosities between 2.09 and 4,3 ΓMΪΓ/S, FIG, 2 also includes the Noack Volatility .Factor according to Equation (J). For kinematic viscosities in the range of 2,4 to 3.8 mnfVs, Equation (3) provides a lower Noack Volatility Factor than does Equation (2). Lower Noack Volatility Factors in the range of base oils having kinematic viscosities from 2.4 to 3.8 Bira'/s axe desired, especially if the base oils axe to be blended with other oϋs that may have higher Noack volatilities.
|00281 Tns aniline point test indicates if an oil is likely to damage elastomers
(rubber compounds) thai come in contact with the oil. The aniline point is called the "aniline point temperature", which is the lowest temperature (T or "C) at which equal volumes of aniline (C6HjNH2) and the oil form a single phase. The aniline point is determined by ASTM D6U-04. In an embodiment, the base oil of the power steering fluid, derived from highly paraffioie wax, have an aniline point greater than 36 x in( Kinematic Viscosity at 1000C) ÷ 200. Accordingly, base oil derived from highly paraffin ie wax exhibits good elastomer compatibility, and performs well with the seals and hoses in power steering systems.
BJEhjy__Pardϊmk.Wax
(0029) The highly paraϊϋnic was. used in making the base oi 1 of the power steering fluid can be any wax having a high content of n-paraffios and having consecutive numbers of carbon atoms. 'The highly paraffmie wax comprises greater than 40 weight % π-paraffuis, such as greater than 50 weigh!. %, or greater than 75 weight %. In ao embodiment, the highly paraffmie waxes also have very low levels of nitrogen and sulfur, generally less ihan 25 ppm total combined nitrogen and sulfur, for example less than 20 ppm. Examples of highly paraffinic waxes include slack waxes, deoiled slack wax.es, refined ibois oils, waxy lubricant ralllnates, n- paraffm waxes, NAO waxes, waxes produced in chemical plant processes, deoiled petroleum derived waxes, microcrystalϋne waxes, Fischer-Tropseh waxes, and mixtures thereof, In axi embodiment the pour points of the highly paπiffink waxes are greater than 50<JC or greater than 60"(I
[003Oj It has been discovered that highly parafiϊnic waxes can be processed to provide base oil having low volatility, high viscosity index, and also having good additive solubility and elastomer compatibility, In an embodiment, the highly paraffimc wax is a Fischer-Tropsch derived wax and provides a Fischer- Tropsch derived base oil.
[0031 J In P iseher-ϊropseh chemistry, hydrogen and carbon monoxide is converted io liquid and gaseous hydrocarbons by contact with a Fischer -Tropsch catalyst under reactive conditions. Examples of conditions for performing Fiseher-Tropseh type reactions are well known to those of ski)! m ihe art. |0032] The Fischer- 1 ropsch synthesis products can be obtained by well- known processes such as, for example., the commercial SASOI.*' Slurry Phase Fischer-Tropsch technology, the commercial SFiELL* Middle Distillate Synthesis (SMDS) Process, or by the Bon-eommerciai EXXON'?: Advanced Gas Conversion ( AOC-21 ) process, Details of these processes and others art: described in, for example, EP-A~776959, I?:P-A-668342, EP-B- 450860; U.S. Patent Nos. 4,943.672. 5i)S9,299, 5,348,982, SS733,839 and RE39073; U.S. Application Publication No. 2005/0227866, WO-A-99349.7, WO-A-9920720 and WOA-05107935. 'ITie FLscher-'ϊ'ropsch syntliesis product usually comprises hydrocarbons having 1 to 100, or even more than 100 carbon atoms, and typically includes paraffins, oieilns and oxygenated products.
[ 00331 The slurry Fischer-Tropsch process utilizes superior heat (and mass) transfer characteristics for the strongly exothermic synthesis reaction and is able to produce relatively high molecular weight, paraflhiic hydrocarbons when using a cobalt catalyst.
{0034) Certain Fischer-Tropsch catalysts are known to provide relatively high chain growth probabilities, and the reaction products include a relatively low proportion of low molecular {C?,x) weight olefins aad a relatively high proportion of high molecular weight (Cso--) waxes. Such catalysis are well known to those of skill in the art and can be readily obtained ami/or prepared.
|00351 The product from a Pischcr-Trαpsch process contains predominantly paraffins, The products from Fischer-Tropsch reactions generally include a light reaction product and a waxy reaction product. The waxy reaction product (i.e., the waxy fraction) includes hydrocarbons boiling above about 6000F (e.g., vacuum, gas oil through heavy paraffins), largely in the C^- range, with decreasing amounts
(0036] The waxy reaction product generally comprises greater than 70 weight % normal paiaffim, and often greater than 80 weight % normal paraffins, ft is the waxy reaction product {i.e., the waxy fraction) that is used as a feedstock to the process for providing Fischer-Tropsch derived base oil in power steering fluids. [0037] The Fischer-Tropsch base oil of the power steering fluid can be prepared .from the waxy fractions of the Fischer. -Tropsch syncrude by a process including hydroisomerization. !.n an embodiment, the Fischer- Trαpseh base oils are made by a process as described in U -S, Patent Application Publication Nos, 2005/0133409 Al and 2006/028933? Al. The Fischer-Tropsch base oil of the power steering fluid is often manufactured at a site different from the site at which the components of the power steering fluids are received and blended.
ErP-^ss ..for jjYo viding ..Base..O.i!
|0038) In an embodiment, the base oil of the power steering fluid is made by a process comprising providing a highly parafiloie wax and then hydroisomerizing the highly paraffinie wax to provide the base oil. The highly paraffhiie wax is hydroisomerized using a shape selective intermediate pore size molecular sieve comprising a noble metal hydrogenation component under conditions of about 600''1F to ?50*F.
[0039 j In ail embodiment the highly paraffinic wax is a f ischer-Tropsch derived wax and ptovide.s a Fiseher-Tropsch derived base oil, Fischer- 1 ropsdi derived base oil can be made by a Fischer- Tropseh synthesis process followed by hydroisomeπzafion of the waxy fractions of the Fischer-Tropsch. synemde,
iivάκ>i§θβ)erization
JO040| The highly paraffmk; waxes are subjected to a process comprising hydroisomerΪKation to provide the base oil of ihe power steering tUikl. Hydroisornerization is intended to improve the cold flow properties of the base oil by the selective addition of branching into the molecular structure. Rydroisomerizadon ideally will achieve high eon version, levels of the highly paratfmjc wax to non-waxy iso-paraffins while at the same time rninirømng the conversion by cracking. IB an embodiment, the conditions for hydroisβmerization are controlled such that the conversion of the compounds boiling, above about 7000F in the waxy feed to compounds boiling below about 700"5F is maintained between about 10 and 50 weight %, for example between 15 and 45 weight %, |'0041] Hydroisomerizaliors is conducted using a shape selective intermediate pore size molecular sieve. The hydroisomerizarkm catalysts used comprise a shape selective intermediate pore size molecular sieve and optionally a cataiytically active metal hydrogenation component on u refractory oxide support. The phrase "intermediate pore size", as used herein, means an effective pore aperture in the range of from about 3.9 to about 7.1 A when the porous inorganic oxide is in the calcined form. The shape selective intermediate pore size molecular sieves used are generally 1-D 10-, 1 1~ or 12-ring molecular sieves. In an embodiment, the molecular sieves are of the 1-D i ϋ-πng variety, where 10* (or I S -or 12-} ring molecular sieves have 10 for 1 1 or 12) tetrahedrally-coordinated atoms (T-atoms) joined by oxygens, in the i-0 molecular sieve, the 10-ring (or larger) pores are parallel with each other, and do not interconnect. Note, however, that 1 -D lO-ring molecular sieves which meet the broader definition of the intermediate pore size molecular sieve bin include intersecting pores having 8-membered rings can also be encompassed within the definition of molecular sieve. The classification of iϊU.razeo!ite channels as I -IX 2~D mid 3-D i≤ set forth bv R. M. Bairer in Zeolites, Science and Technology, edited by F. R, Rodrigues. L.D, Rollmao and C, Naccacbe, NA TO ASI Series, 1984 which classification is incorporated in its entirety by reference (see particularly page 75), j'0042j Other shape selective intermediate pore sk.e molecular sieves- used for hydroisαnierizatkm are based upon aluminum phosphates, such as SAPO- i L SAPO-33, and SAPO-4L SM-3 is an example of a good shape selective intermediate pore size SAPO, which has a crystalline structure falling within that of Ae SAPO-I ) molecular sieves. The preparation of SM-3 and its unique characteristics are described in U.S. Patent Nos, 4,943,424 and 5,158,665, Other shape selective intermediate pore size molecular sieves used for hydroϊ somen zaϋ on are zeolites, such as ZSM-22, ZSM-23, ZSM-35, ZSM-48, 2SM-57, SSZ-32, offVetite, and femerite, f rø43| In an embodiment, an intermediate pore size molecular sieve is characterized by selected crystallographic free diameters of the channels, selected crystallite size (corresponding to selected channel length K and selected acidity. Desirable crystallographic free diameters of the channels of the molecular sieves are in the range offro.ro about 3.9 to about 7.1 A, having a maximum crystal lographic free diameter of not more than 7,1 and a minimum erystallographk free diameter of not less than 3.9 A. In this embodiment, the maximum crystal lographic free diameter iβ not more than 7.1 and the minimum crystailographic free diameter is not less than 4,0 A. Irs an embodiment, the maximum, erystallograpliic free diameter is not more than 6.5 and the minimum crystailographic free diameter is not less than 4.0 A. The CT ystal lographic free diameters of the channels of molecular sieves are published in the "Atlas of Zeolite Framework Types", Filth Revised Edition, 20Oi, by Ch. Baerlochex, W. M. Meier, and D.B. Olson, ESsevier. pp 10-15. [0044J An example of an intermediate pore size molecular sieve is described, for example, in U.S. Patent Nos. 5.135.638 and 5.282,958. In U.S. Patent No. 5,282,958, such an intermediate pore size molecular sieve lias a crystallite size of no more than about 0.5 microns and pores with a minimum diameter of at least about 4.8 A and with a maximum diameter oϊ about 7.1 A. The catalyst has sufficient acidity so that 0,5 grams thereof when positioned in a tube reactor converts at least 50% of hexaάεeane as. 3700C, a pressure of 1200 psig, a hydrogen flow of 160 rnlZmin, and a feed rate of 1 mi/hr. The catalyst also exhibits isαmetization selectivity of 40 percent or greater (isonierizatioo selectivity is determined as follows; 100 x (weight % branched C^, iα product) / (weight % branched Cj*, in product ■!■ weight % Cp. in product) when used under conditions leading to 96% conversion of normal hexadecane (n-Cu;) to other species.
|0045l In an embodiment, the molecular sieve can further be characterized by pores or channels having a. crystal iographie free diameter in the range of from about 4,0 to about 7.1 A, for example, in the range of 4.0 to 6,5 A. The crystaliograp.hic free diameters of the channels of molecular sieves are published in the "Λtlas of Zeolite Framework Types", Fifth Revised Edition, 2001 , by CIi. Baerlocher, W. ML Meier, and DJ-f Olson, Elsevier, pp 10-15, [0046J If the erystaϊlographic free diameters of the. channels of a molecular sieve are unknown, the effective pore size of the molecular sieve can be measured using standard adsorption techniques and hydrocarbonaceous compounds of known minimum kinetic diameters. See Breck, Zeolite Molecular Sieves. 1974 (especially Chapter 8); Anderson et at J. Catalysis 58» 1 14 (1979); and ϋ.S, Patent No. 4,440,871 . In performing adsorption measurements to determine pore size, standard techniques are used. It is convenient to consider a particular molecule as excluded if does not reach at least 95% of its equilibrium adsorption value on the molecular sieve in less than about 10 minutes CpZp0 ::: (KS at 250C). Intermediate pore size molecular sieves will typically admit, molecules having kinetic diameters of ,13 to 6,5 A wills, little hindrance,
(0047J Hydroisomeπzaticn catalysts often comprise a eatalytically active hydrogenatioi) metal. The presence of a caialyticaUy active hydrogenation metal leads to product improvement, especially viscosity index and stability. Typical eatalytically active .hydrogmation metals include chromium, molybdenum, nickel, vanadium, cobalt, tungsten, zinc, platinum, and palladium. In an embodiment the eaUiJyticaUy active hydrogen metals are selected from plairaum, palladium, and
! d mixtures thereof if platinum and/or palladium is used, the total amount of active hyd.rogenation metal is typically in ihe range of U.I to 5 weight percent of the total catalyst usually from 0.1 to 2 weight percent, and not to exceed 10 weight percent. |0048j The refractory oxide support cars be selected from, those oxide supports, which are conventionally used for catalysts, including silica, aϊuπύrau silica-alumina, magnesia, litaula and combinations thereof, (01)49] The conditions for hydroisorrseroation will be tailored to achieve a base oil comprising greater than 5 weight. % molecules with cydoparafilnic functionality. In an embodiment, the conditions provide a base oil comprising a ratio of weight percent of molecules with morioeycloparaffimc functionality of weight percent of molecules with mυlticyciøparaffmic functionality of greater than 5, such as greater than 10, greater than 15, or greater than 20. The conditions for Iiydroisomerizaiion will depend on the properties of feed used, the catalyst used, whether or not the catalyst is sulfϊded, the desired yield, and the desired properties of the base oil. Conditions under which ihe hydroisoraenxation process can be carried out include temperatures from about DOCF'F to about '/75'T (26(FC to about 415°Cκ such as 6000F to about 750T {3 i 50C io about 3990C), or 600cF TO about 70CfF (3 l5°C to about 371"C); arid pressures from about 15 to 3000 psig, such as 100 to 2500 psig. The hydroisomerizadon pressures in this context refer to the hydrogen partial pressure within the hydrotsorøerization reactor, although the hydrogen partial pressure is substantially the same (or nearly the same) as the total pressure. The liquid hourly space velocity during contacting is generally from about 0,1 to 20 hx'\: for example, from about 0.1 to about 5 h/!. The hydrogen to hydrocarbon ratio falls within a range from about 1 0 to about 50 moles H? per mole hydrocarbon, for example, from about 10 to about 20 moles H> per mole hydrocarbon. Suitable corsdiuons for performing hydroisonierization are described in U.S. Patent Nos 5,282.958 and 5, 135.638.
JOOS(Jj Hydrogen is present in the reaction zone during the hydroisomerizatiori process, typically in a hydrogen to feed ratio from about 0.5 io 30 MSCP/bbi thousand standard cubic feet per barrel), such as from about 1 to about 10 MSCF/bbl. In an embodiment the hydrogen to feed, ratio is from about 712.4 to about 3562 liter H?/Iiter oil (about 4 to about 20 MSCF/bbl ,κ Hydrogen will sometimes be separated from the product and recycled to the reaction zone.
OXdrcHreairng fOflSl] The highly parafimie waxy feed to the hydroisomerization process will sometimes be hydrotreated prior to hydroisorneozation. Bydrotreatirsg refers to a catalytic process, usually carried out in the presence of free hydrogen., in which the primary purpose is the removal of various metal contaminants, such as arsenic, aluminum, and cobalt; heteroatoms, such as sulfur and nitrogen; oxygenates; or aromatics from the feed stock. Generally, in hydrotreating operations cracking of the hydrocarbon, molecules, Ie , breaking the larger hydrocarbon molecules into smaller hydrocarbon molecules, is minimized, and the unsaturated hydrocarbons are either fully or partially hydrogenated,
Liv.drofiπisiiipg
{0052] Hydro finishing is a hydrotreaiing process that will often be used as a step following hydroisoraerizatioπ. to provide base oil derived from highly paraffirue wax. RydroSnishing is intended to improve oxidation stability, UV stability, and appearance of base oil by removing traces of aromatics, olefins, color bodies, and solvents. As used herein, the term UV stability refers to the stability of base oil or power steering fluids when, exposed to UV light and oxygen, instability is indicated when a visible precipitate forms, usually seen, as Doc or cloudiness, or a darker color develops upon, exposure to ultraviolet, light and air. A general description of bydrofmishmg can be found m U.S. Patent Nos. 3,852,20? and 4,673,487. Clay treating to remove impurities is an alternative final process step to provide base oil derived irom highly paraffinic wax. Fractionation
|0053] Optionally, the process to provide the light base oil derived from highly paraftinic wax cm include fractionating the highly paraffiπic waxy feed prior to Uydroisomcrisation, or fractionating of base- oil obtained from the hydroisoraerization process. The fractionation of the highly paraffinie waxy feed or the isomerized base oil into fractions is generally accomplished by either atmospheric or vacuum distillation, or by a com.bi.na don of atmospheric and vacuum distillation. Atmospheric distillation is typically used to separate the lighter distillate fractions, such as naphtha and middle distillates, from a bottoms fraction having an initial boiling point above about 6OG41F to about 750"F (about 315°€ to about 399*CX At higher temperatures thermal cracking of die hydrocarbons can take place leading to ibuiing of the equipment and to lower yields of the heavier cuts. Vacuum distillation is typically used to separate the higher boiling material. such as base oil, into different bo.ili.ng range cuts. Fractionating base oil into different boiling range cuts enables base oil manufacturing plant to produce more than one grade, or viscosity, of base oil.
Solveni Devyaxing
{0054} The process to make base oil derived from highly paraffinic wax will sometimes also includes a solvent dewaxing step either before or following the hydroisomerization process. Solvent dewaxing optionally can be used to remove small amounts of remaining waxy molecules from base oil after hydroisornerizaϋon. Solvent dewaxing is done by dissolving base oil in a solvent, such as methyl ethyl ketone, methyl iso-butyi ketone, or toluene, or precipitating the wax molecules as discussed m Chemical Technology of Petroleum, 3rd Edition, William Gruse and Donald Stevens, McGraw-Hill Book Company, Inc.. New York. 1960, pages 566 to 570. Solvent dewaxing is also described in U.S. Patent Nos. 4,477,333, 3,773,650 and 3.775,288. Ba^ε.OJl.Derived Jτorn ..Hi£My..Faiajllnic_Wax
[MiSSj Base oil derived from highly paraffinie wax is suitable for use in power steering fluids. Iu an embodiment base oil derived from highly parafiϊnie wax has a vis-cυshy of between about 12 ninvvs and about 4.0 mm'/s, such as between about 1.5 and about 3.5 mm"/s at !00"1C, or between about 2 nirαVs and ■about 3.5 rami's at 1000C, or between about 2 mra'Vs and about 3.0 mπr/s at ] 000C. lipase oil derived from highly paraffliric wax advantageously has a low Moaek volatility. In an embodiment, base oil derived from highly paraffinic wax has a Noack volatility between 0 and 100 weight %. and less than the Noack Volatility Factor as calculated by the following equation:
Noack Volatility factor ::: 160 - 40(Kmeinaϋc Viscosity at 10Cr1C). In an embodiment, base oil derived .from highly paraffinie wax ha^ a Noack volatility of less than 100 weight %, such as less than 50 weight % or 35 weight %. Accordingly, base oil derived from highly paraffinic wax advantageously has both high viscosity index and. low volatility,
|0056j In an embodiment, base oil derived from highly paraffinic was. has a viscosity index of greater than 101. In an embodiment, base oil derived from highly paraffuύc wax has a viscosity index of between about S 05 and about 160. [0057] In an embodiment, the viscosity index of base oil derived from highly paraiiϊniε wax is greater than the Viscosity index Factor a.s calculated by the fol lowing equation:
Viscosity Index Factor ™ 28 x LnfKmernaϋc Viscosity at i00°C) 4- 101. In embodiments, base oil derived from highly paraffinic wax comprises a weight % of molecules with cycloparaffinic functionality of greater than the kinematic viscosity at HMFC multiplied by three.
[0058] In an embodiment, the base oil of the power steering fluid comprises less than 5 weight %. such as less than 1 weight % or (ess than 0.5 weight %, of unsaturates. In an embodiment the base oil of the power steering fluid comprises greater than 5 weight % molecules with cycloparaffinic functionality. Lo an embodiment, the base oil of the power steering fluid comprises a ratio of weight percent of molecules with rminocyeloparaffimc functionality to weight percent of molecules with .nmlticyeloparaffirήc functionality of greater than 5. such as greater than 10, greater than 15, or greater than 20, The base oil of the power steering fluid generally comprises less than 0,30 weight percent molecules with aromatic functionality, such as less than 0.1 or less than 0.05 weight percent. (IHJ59J In. an embodiment, the base oil of the power steering .fluid comprises greater than 5 weight percent molecules with eycϊoparaffiπic functionality. in embodiments, the base oil of the power steering fluid comprises a ratio of weight % of molecules with monocycloparaffmic functionality to weight % of molecules with πmiticycloparaffmic functionality of greater than 5, such as greater than 10, greater than. 15, or greater than 20. In an embodiment, the base oil of the power steering fluid comprises a ratio of weight percent of molecules with cycloparaffeue functionality of greater than the kinematic viscosity at. I GO0C multiplied by three. JO06OJ In some embodiments, the base oil of the power steering fluid comprises less than 19 alky! branches/100 carbons, for example, greater than 9 alky ! branches./ 100 carbons and less than 19 alky I branches/ 100 carbons. The base oil of the power steering fluid can also have specific alky! branching placements, In an embodiment, the base oil of the power steering fluid comprises predominantly methy! branching, and the branching is such that there are 6 to 18 alkyl branches per 100 carbons; greater than 25% of the branches are 5 or more carbon atoms apart from each oilier; and less than 4014 of the branches are within 2 io 3 carbon atoms apart from each other. Examples of these types of base oils are taught in U.S. Patent Application Publication No. 2005/0077208 Al.
[0061] Base oil containing desired levels of molecules with cyeioparafimic functionality exhibits good 3oh.sbii.ity for additives, including viscosity index improvers and lubricant additive packages, because molecules with cycioparaffmie functionality impart additive solubility. Base oil containing a high ratio of weight percent of molecules with nionocycloparaffmic functionality to weight percent of molecules with rnuiticycloparalTuiic functionality (or high weight percent of molecules with nionocycloparaffiuic functionality and low weight percent of
. I Q . molecules with multicycioparafiinic functionality} are also desirable because molecules with multicyclαparaffirue functionality reduce oxidation stability, lower viscosity index, and increase Noaek volatility. Accordingly, the base oil exhibits good oxidation stability and high Noack volatility. l'0062-i In an embodiment, the bass oil of the power steering fluid has an aniline point greater than 36 x In(Ki nomatic Viscosity at 1000C) + 200. Accordingly, the base oil exhibits good elastomer compatibility, and do not damage seals and hoses in power steering systems.
|00631 In an embodiment, the base oil of the power steering Fluid contains greater than 95 weigh! % saturate^ such as greater than 99 weight % or greater than 99.5 weight %, as determined by elation column chromatography, ASTM D2549- 02. Olefins are present in an amount less than detectable by long duration C l" Nuclear Magnetic Resonance Spectroscopy (NMR)1 in an embodiment, molecules with aromatic functionality are present in amounts less than 0,3 weight percent by HPLC-UV, and confirmed by ASTM D5292-99 modified to measure low level aromaties. In an embodiment, molecules with aromatic functionality are present in amounts less than 0.10 weight percent, such as less than 0,05 weight percent, or less than 0,0.1 weight percent. Sulfur is present in amounts less than 25 ppm, such as 5 ppm. or less than 1 ppm as determined by ultraviolet fluorescence by ASTM D5453- 06.
[Θ064] Base oil derived from highly pararϊime wax does not. introduce any undesirable characteristics, including, for example, high volatility, high viscosity, and impurities such as heterøaioms, to the power steering liukl In an embodiment, the base oil is a Fiseher-ϊropsch derived base oil. Piseher-Tropsch derived waxes are particularly well suited for providing Fischer-Tropseh derived base oil with the above-described properties .
Λroimmcs Measurement hy HPLC-UV.
[0065] The method used to measure low levels of molecules with aromatic fuDctionalnv in the base oils uses a .Hewlett Packard 1050 Series Quaternary Gradient High Performance Liquid Chromatography (HPLC) system coupled with a MP HsSi) Diode- An ay UV -Vis detector interfaced Io an HP €hem-staύon. Identification of the individual aromatic classes in the highly saturated base oils was made on the basis of their UY spectral pattern ami their elation time. The ami.no column used for this analysis differentiates aromatic molecules largely on the basis of their ri rag-number (or more correctly, double-bond number). Thus, the single ring aromatic containing molecules would elate first, followed by the polyeyciic aromarics in order of increasing double bond number per molecule. For aromatic s with similar double bond character, those with only alkyl substitution on the ring would ekue sooner than those with eyeloparaffimc substitution. {0066] Unequivocal identification of lhe various base oil aromatic hydrocarbons from their UV ahsorbance spectra was somewhat complicated by the fact their peak electronic transitions were all red-shifted relative to the pure model compound analogs to a degree dependent on the amount of alkyl and cycloparaffinic substitution o.n the ring system. These batbociironiic shifts are well known to be caused by alkyl-group derealization of the π-eiectrems in the aromatic ring. Since few unsubstituted aromatic compounds boil, in the lubricant range, some degree of red-shift was expected and observed for all of the principle aromatic groups identified.
[0067} Quantification of the eluting aromatic compounds was made by integrating chroniatograrns made from wavelengths optimized for each genera! class of compounds over the appropriate retention time window for that aromadc Retention time window limits for each aromatic class were determined by manually evaluating the individual absorhance spectra of eiutitig compounds ai different times and assigning them to the appropriate aromatic class based on their qualitative similarity to model compound absorption spec int. With few exceptions, only lϊs'e classes of aromatic compounds were observed in highly saturated API Group ΪI and "111 base oils. HPLC-UV Calibration:
[006Sj H PLC-U V is used for identifying these classes of aromatic compounds even at very low levels. Multi-ring aroraatics typically absorb 10 to 200 times more strongly than single-ring aromaties, AlkyL-substitutkm also affected absorption by about 20%. Therefore, it is important to use HS5LC to separate and identify the various species of aromaties and know how efficiently they absorb. J0069J Five classes of aromatic compounds were identified. With the exception of a small overlap between the most highly retained alkyl-cycloalkyi-l- ring aromaties and the least highly retained alkyl naphthalenes, all of the aromatic compound classes were baseline resolved, integration limits for the eo-eluting 1- rifig and 2-ring aromaties at 272 ran were made by the perpendicular drop method. Wavelength dependent response factors for each general aromatic class were first determined by constructing Beer's Law plots from pure model compound mixtures based on the nearest spectral peak absorbances to the substituted aromatic analogs. fi)070] For example, alkyl-cyclohexylbeiizene molecules in base oils exhibit a distinct peak absorbance at 272 arn that corresponds to the same ('forbidden) transition ihat unsυbstituted tetrahn model compounds do at 268 nm. The concentration of aik_yl-cyck>alkyl-i-ring aromaties m base oil samples was calculated by assuming that its molar absorptivity response factor at 272 nm was approximately equal to tettalin's molar absorptivity at 268 nm, calculated from Beer's law plots. Weight percent concentration's of aromaties were calculated by assuming that the average molecular weight for each aromatic class was approximately equal to the average molecular weight for the whole base oil sample, [0071] This calibration method was further improved by isolating the i-ri.og aromaties directly from the base oils via exhaustive HPLC chromatography. Calibrating directly with these aromaties eliminated the assumptions and uncertainties associated with the mode! compounds, As expected, the isolated aromatic sample had a lower response factor than the model compound because it was more highly substituted [00721 More specifically, to accurately calibrate the HPLC-UV method, the substituted benzene aromaties were separated from the bulk of the base oil using a Waters semi -preparative RPLC unit. Ten grains of sample was diluted 1 :1 in n- hεxane and injected onto an ammo-bonded silica column, a 5 cm x 22,4 mm ID guard, followed by two 25 cm x 22.4 mm ID columns of S-- 12 micron aroino-bondεd silicas, panicles, manufactured by Raimn instruments, Emeryville, California, with π- hexane as the mobile phase at a flow rate of I8mk/.oim, Column εiuent was fractionated based on the detector response from a dual wavelength UV detector set at 2(SS nm and 295 nm. Saturate tractions were collected until the 265 nm absofoance showed a change of 0,0i absorban.ee units, which signaled the onset of single ring aromatic elution. A single ring aromatic fraction was collected until the absorbance ratio between 265 ran and 295 mil decreased to 2,0, indicating the onset of two ring aromatic elution. Purification and separation of the single ring aromatic fraction was made by re-ehrornalographmg the monαaromatic fraction away from the "tailing" saturates fraction which resulted from overloading the HPLC column. |D073] This purified aromatic "standard" showed thai aϊkyi substitution decreased the molar absorptivity response factor by about 20% relative to unsubslituteU teimlirs.
Confirmation of Aromatics by NA-fR. j'0074| The weight percent of molecules with aromatic functionality in the purified mono-aromatic standard was confirmed via lo.og~dnrati.on carbon 13 NMR analysis. NMR was easier to calibrate than HPLC UV because it simply measured aromatic carbon so the response did not depend on the class of aromatics being analyzed. The NMR results were translated from % aromatic carbon lυ % aromatic molecules (to bε consistent with HPi-C-UV and D 2007 i by knowing that 95-99% of the aromatics in highly saturated base oils were single-ring aromatics.
100751 High power, long duration, and good baseline analysis were needed to accurately measure aromatics down to 0.2% aromatic molecules. |0076j More specifically, to accurately .measure low levels of all molecules with at least one aromatic function by NMR, the standard DS292-99 method was modified to give a minimum carbon sensitivity of 500: i (by ASTM standard practice E 386). A 15-hour duration ran on a 400-500 M.Hz NMR. with a 10-12 mm Nalorae probe was used. Acorn PC integration software was used to define the shape of the baseline and consistently integrate. The carrier frequency was changed once during the run to avoid artifacts from imaging the aliphatic peak into (he aromatic region. By taking spectra on either side of the carrier spectra, the resolution was improved significantly.
Cycloparaffin Distribution by FIMS:
[0077] Paraffins are considered more stable than cycloparaffins towards oxidation, and therefore, more desirable. MonocycloparafOns are considered more stable than multicycloparaffins towards oxidation. However, when the weight percent of all molecules with at least one eydoparaffinie function is very low in an oil, the additive solubility is low and the elastomer compatibility is poor. Examples of oils with these properties are Fischer- Tropsch oils with less than about 5% cyeloparaffios. To improve these properties in power steering fluids, expensive co- solvents such as esters must often be added, hi an embodiment, base oil, derived from highly parafiinic wax and used as dielectric fluids, comprises a high weight percent of molecules with monoeycloparaffimc functionality and a low weight percent of molecules with rrmlticycloparaffinic functionality such that the base oil has high oxidation stability, low volatility, good miseibility with other oils, good additive solubility, and good elastomer compatibility,
(0078) The base oils of the power steering fluid wtre characterized by field ionization .mass spectroscopy (.FIMS) into alkanes and molecules with different numbers of unsaturating. The distribution of molecules in the base oil was determined by FIMS. FlMS spectra were obtained o.n a lviieromass VG 7QVSE mass spectrometer. The samples were introduced via a solid probe into the spectrophotometer, for example., by placing a small amount (about 0.1 rng) of the base ail to be tested in a glass capillary tube. The capillary tube was placed ai the tip of a solids probe for a mass spectrometer, aixi the probe was healed from about 4ø*€ up to 5000C at a rate of 50"1C per minute, operating under vacuum at approximately I Cr1 Ton*. The mass spectrometer was scanned from rn/'z 40 to m/'z 1000 at a rate of 5 seconds pet decade. The acquired mass spectra were summed to generate one "averaged" spectrum. Each spectrum was °C corrected using a software package from PC-MassSpec,
[0079} Response factors for all compound types were assumed to be 1.0, such Chat weight percent was determined from area percent. The acquired mass spectra were summed to generate one "averaged" spectrum. The output from the FiMS analysis is the average weight percents of alkanes, 1 -unsaturations, 2- υnsaturations, 3~unsatυratioj«s. 4-unsaturations, 5-u.nsaturaiions, and 6-unsafuraϋoπs in the test sample.
[0080] The molecules with different numbers of ansatur atioπs can be comprised of cyeloparafϊhis.. olefins, and aromatics. If aromatics were present in significant amounts in the base oil they would most likely be identified in the FlMS analysis as 4~uri.satuτa lions. When olefins were present in significant amounts in the base oil they would most likely be identified in the FlMS analysis as 1- unsaturations. The total of the l -unsaiuratioos, 2~υnsatυrations, 3~υ..osatιirations, 4- unsaiuratioRSj 5-unsaturations, and 6-unsaturations from the FiMS analysis, minus the weight percent of olefins by proton NMR1 and minus the weight percent of aromatics by HPLC-UV is the total weight percent of molecules with cycJoparafftnie functionality in the bass oils of the power steering fluid. The total of the 2- Uf) saturations, 3 -uαsaturations, 4-unsaturations, SHinsainratiorw, and 6-misaturations frorn the FiMS analysis, minus the weight percent of aro.mat.ies by HPLC-UV is the weight percent of molecules with niυltkrycloparaffinic functionality in the base oils of the power steering fluid. Note thai if the aromatics content was .not measured, it was assumed to be less than 0.1 weight % and not included in the calculation for total weight percent of molecules with cycloparafiinic functionality. [008 Ij In an embodiment, base oil derived from highly paraffuiic wax lias a weight percent of molecules with cyeiopar&ffrnie functionality greater than 5. Ln an embodiment, base oil derived from highly paraffinic wax also has a high nnio of weight percent of molecules with monocycloparaffmic functional ity to weight percent of molecules with multicydop&raffimc functionality, generally greater than 5. greater than 10, greater than 15, or greater than 20.
[0582] In an embodiment, there is a relationship between the weight percent of all molecules with at least one cycloparaffinic functionality aird the kinematic viscosity of the base oils of the power steering fluid, derived from highly paraffinic wax. That is, the higher the kinematic viscosity at 100"'1C in mnf/s, the higher the amount of molecules with cycLoparaffinie functionality that are obtained, In an embodiment, base oil derived from highly paraffinic wax has a weight percent of molecules with cycioparaffinic functionality greater than the kinematic viscosity in rnnfϊs multiplied by three, hi an embodiment, base oil derived from highly paraffinic wax has a kinematic viscosity at IQO0C between about 1.2 mirf/s and about 4,0 iiim'/s, for example between about 1.2 nmc/s and about 3.5 tam"/s, or between about 2.0 rami's and about 3,5 rmrvVs, or between about 2.0 m.ra'/s and about 3.0 mrrr/s,
{0083] The modified ASTM D5292--99 and HPLC-UV lest methods used to measure low level arornatics, and the FΪMS tesi method used to characterize saturates are described m D.C. Kramer, et aL "Influence of Group H & IK Base Oil Composition on viscosity index and Oxidation Stability"., presented at the 1999 AIChE Spring National Meeting in Houston, March i{>; 1999. the contents of which is incorporated herein in its entirety.
(0084] Although the highly paraffinic waxy feeds are essentially free of olefins, base oil processing techniques can introduce olefins, especially ai high temperatures, due to 'cracking' reactions. In the presence of heat or UV light, olefins can polymerize to form higher molecular weight products thai can color the base oil or cause sediment, hi general, olefins can be removed by hydrotinishiog or by clay treatment. Addύjves
I'OOSSJ The additives for use in base oi Is Io provide power steering fluids include additives selected from ihe group consisting of viscosity index improvers, pour point depressants, detergents, dispersatsts, fkitdmng agents, friction modifiers, corrosion inhibitors, rust inhibitors, antioxidants, detergents, seal swell agents, antiwear additives, extreme pressure (EP) agents, thickeners, friction modifiers, colorants, dyes, color stabilizers, ami foam agents, corrosion inhibitors, rust inhibitors, seal swell agents, metal deactivators, deodorizers, de.mulsi.Oets> anti- squeal agents, and mixtures thereof.
\ύOM\ The additives can be in the form of a lubricant additive package, which comprises several additives to provide a power steering fluid with desirable properties. Lubricant additive packages for use in base oils to provide power steering fluids include lubricant additive packages selected from the group consisting of viscosity index improvers, pour point depressants, detergent-inhibitor (Dl) additive packages, and mixtures thereof ϊ ■ Yi^osi 1 y^ jlldex improvers
[0087J Viscosity index improvers modify the vLscometrie characteristics of luhrieants by reducing the rate of thinning with increasing temperature and the rate of thickening with low temperatures. Viscosity index improvers thereby provide enhanced performance at low and high temperatures. Io many applications, viscosity index improvers are used in combination with detergent -inhibitor additive packages to provide a. power steering fluid,
[0088 j The viscosity index improvers can be selected from the- group consisting of olefin copolymers, co-polymers of ethylene and propylene, poiyalkylaerylates., potyalkylmethacryiafes, styrene esters, poiyisobutylene. hydrogenated styrerse-Lsoprene copolymers, star polymers, including those having tetrabiock copolymer arms of hydrogenated pojyisoprene-poiybuiadiene- poiyisoprene with a block of polystyrene, or hydrogenated asymmetric radial polymers having molecules with a core composed of the remnant of a tetravaknt silicon coupling agent, a plurality of rubbery arms comprising polymerized dϊene units and a block copolymer arm having at least one polymerized diεnε block and a polymerized monovϊnyϊ aromatic compound block, hydrogeπated styrenε- buiadienes, arsd mixtures thereof. Ia an embodiment, the viscosity index improver is an ethyieπe/a -olefin interpolymer as described in WO 2006/102146 A2> wherein the ethyleue/a~oiefm interpolymer is a block copolymer having at least a hard block and at least a soft block. The soft block comprises a higher amount of comon.oin.ers $haπ the hard block, In an embodiment, the viscosity index .improver is an acrylic acid ester polymer comprising a copolymer derived from a first acrylic acid ester monomer having from about 1 io about 4 carbon atoms, a second acrylic acid ester monomer having from about 12 to about 14 carbon atoms, and a third acrylic acid ester monomer having from about 16 to about 20 carbon atoms, as described ΪΏ U S. Patent Application Publication No, 2006/0252660 AL wherein the copolymer has weight average molecular weight of 20.OCO-I OO5OOO daitons and contains 1 weight % or less of u.nreacted monomer.
|00Sl>] Pour point depressants used in power steering fluids modify the wax crystal morphology such as to reduce interlocking of the wax crystals with consequent viscosity increase or geiktion. Examples of pour point depressants are alkylated naphthalene and phenolic polymers, polymethacrylaies, alkylated bicyclic aromatics. mafeate/fumarate copolymer esters, methacry late-vinyl pyrrolidone copolymers, styrene esters, polyfυmerates, vinyl aeetatε-furaarale co-polymers, dialkyl esters of'phthaiate acid, ethylene vinyl acetate eørnpoiyersf and other mικed hydrocarbon polymers from commercial additive suppliers such as UJ BRIZOL5 the ETHYL Corporation, or ROMMAX, a Division of Degussa. ffi- Piiyii^>i?>l.BMudl]£.B.klA4 iloraponent
[0Θ90] hi some erobodiraents a base oil pour point reducing blend component cars be used. As used herein, "pour point reducing blend component" refers to an isome.rized waxy product with relatively high molecular weights and a specified degree of alky I branching in the molecule, such that it reduces the pour point of lubricating base oil blends containing it Examples of a pour point reducing blend component are disclosed in U.S. Patent Nos, 6,350,577 and 7.053.254,. and U.S. Patent. Application Publication No. US 2005-0247600 Al A pour point reducing blend component can be: I t an isorøerized Fischer- 'i ropsch derived bottoms product; 2) a bottoms product prepared from an isomerued highly waxy mineral oil, or 3) an isomerized oil having a. kinematic viscosity at 1000C of at least about S mnvVs made from polyethylene plastic,
[0091 \ \& one embodiment, the pour point reducing blend component is an isonierized Fischer-Tropsch derived vacuum distillation bottoms product having an average molecular weight, between 600 and 1 100 and an average degree of branching in the molecules between 6,5 and 10 alkyi branches per 100 carbon atoms. Generally, the higher molecular weight, hydrocarbons are more effective as poor point reducing blend components than the lower molecular weight hydrocarbons. In one embodiment, a higher cut point in a vacuum distillation unit which results in a higher boiling bottoms material is used to prepare the pour point reducing blend component, The higher cut point also has the advantage of resulting in a higher yield of the distillate base oil fractions, hi one embodiment, the pour point reducing blend component is an isoraenzed .Hseher-Tropsch derived vacuum uisrillation bottoms product having a pour point that is at least 3*C higher than the pour point of the distillate base oil it is blended with.
[0092] IB one embodiment, the 10 percent poini of the boiling range of the pour point reducing blend component that is a vacuum distillation bottoms product is between about 850-1050'"'F (454-565 0C). in another embodiment, the pour point reducing blend component is derived from either Fischer-Tropsch or petroleum products, having a boiling range above 9500F ( S I O0C K and contains at least 50 percent by weight of paraffins, hi yet another embodiment the pour point reducing blend component has a boiling range above 1050° F C565°C}. |0093J in another embodiment, the pour point reducing blend component is an isomεnzeά petroleum derived base oil containing material having a boiling range above about ! 05(PP. In one embodiment, the isomerized bottoms material is solvent dewaxed prior to being used as a pour point reducing blend component. The waxy product further separated during solvent dewaxing from the pom point reducing blend component were found to display excellent improved pour point depressing properties compared to the oily product recovered after the solvent dewaxing. |OΘ94j In another embodiment, the pour point reducing blend component is an iaomcrizεd oil having a kinematic viscosity at 1000C of at. least about 8 ram'/s made from polyethylene plastic. In one embodiment the pour point reducing blend component is made -from waste plastic, in another embodiment the pour point reducing blend component is made from steps comprising pyrolysis of polyethylene plastic, separating out a heavy fraction, hydrotreatiπg the heavy fraction, catalytic isomerrang the hydrotreated heavy fraction, and collecting the pour point reducing blend co.mpo.nent having a kinematic viscosity at 1000C of at least about 8 mm"/s, Su a third embodiment, the pour point reducing blend component derived from polyethylene plastic and has α boiling range above K)SO0F (5650G')., or even has a boiling range above 12OD0F (6400C).
[00951 1« orse embodiment, the pour point reducing blend component has an average degree of branching in. the molecules -within the range of from 6.5 to 10 aikyi branches per 100 carbon atoms, hi another embodiment, the poirr point reducing blend component has an average molecular weight between 600-1 100. (n a third embodiment it has an average molecular weight between 700- 1000, in. one embodiment, the pour point reducing blend component has a kinematic viscosity at 100rjC of 8-30 mm7s- with the 10% point of the boiling range of the bottoms falling between about 850-1050"F In yet another embodiment, the pour point reducing bienά component has a kinematic viscosity at 100°C of 1 5-20 ranrv's and a pour point of ~8 to ~12°C,
JO [0Θ96J In one embodiment, the pour point reducing blend component is an isoraenzeα on having a kinematic viscosity at 1000C of at least about 8 ninrVs made from polyethylene plastic. In one embodiment the pour point reducing bknd component is made from waste piasiie. In another embodiment ihe pour point reducing blond component is made from stops comprising pyrolysis of polyethylene plastic separating out a heavy fraction, αydrotreatmg the heavy fraction, catalytic iso.rnerkd.ng the hydrotreated heavy .traction, and collecting the pour point reducing blend component having a kinematic viscosity at iOO':'C of at least about 8 mni'/s hi a third embodiment, the pour point reducing blend component derived from polyethylene plastic has a boiling range above IUS(PP (565°C). or even a boiling range above 120(PF (649ύC).
[0097] Detergent-inhibitor additive packages serve to suspend oil contaminants, as well as to prevent oxidation of the power steering fluids with the resultant formation of varnish and sludge deposits. The detergent-inhibitor additive package useful in power steering fluids contains one or more conventional additives selected from the group consisting of dispersants, flυidizhig agents, friction modifiers, corrosion inhibitors, rust inhibitors, antioxidants, detergents, seal swell agents, extreme pressure additives, aαtiwear additives., deodorizers, antifoarn agents, dcmulsilϊerSj colorants, and color stabilizers. The detergent-inhibitor additive package is present in an amount of from 2 to 2$ weight percent, based on the total weight of the power steering fluid composition. Detergent-inhibitor additive packages are readily available from additive suppliers such as 1,UBRIZOL,, ETHYL., Oronite, and ΪNFΪNEIJM A number of detergent- inhibitor additives are described iα EP 0 978 555 Al , V . Dispersants
[0098J Dispersarsts are used iα power steering fluids to disperse wear debris and products of lubricant degradation within the equipment being lubricated {i.e.. power steering equipment}. The ashless dispersants commonly used contain a Lipophilic hydrocarbon group and a polar functional hydrophilic group. The polar functional group can be of the class of c&rboxylatε, ester, amine, amide, inline. imide. hydroxy]., ether, epoxide, phosphorus, ester carboxyl, anhydride, or nkriie The lipophilic group can be αhgomeric or polymeric m nature, usually from 70 to 200 carbon atoms to ensure good oil solubility. Hydrocarbon polymers treated with various reagents to introduce polar functions include products prepared by treating polyolefms such as pojyisobutεrse first, with maleic anhydride, or phosphorus sulfide or chloride, or by thermal treatment, and then with reagents such as polyamine, amine, ethylene oxide, etc. f0099| Of these ashless dispersants the ones typically used in power steering fluids include N-substituιed polyisobuteπyl suecrnimides and succinates, alkyl rnethacryiate- vinyl pyrrolidinone copolymers, alkyl methacrylaie-dialkylaminoethyl methacrylatc copolymers, alkylmetbacryiate-polyethylene glycol methacryiate copolymers, and polysteararrsides. Some oil-based dispersants that are used in power steering fluids include dispersants from the chemical classes of alkylsuccimmide, succinate esters, high molecular weight amines, and IVfannieh base and phosphoric acid derivatives. Some specific examples are polyisobuteπyl succirjimide-poiyetbylencpoiyaffiine, polyisobuteny! succinic ester, polyisobutenyl hydroxybenxyl-polyethykucpolyaruiπe, bis-liydtoxypropyi phosphurate. C'ornmercial dispersants suitable for power steering fluid are for example, [,UBRIZOL 890 (an ashless PlB succinimide), LUBRiZOL 6420 fa high molecular weight PlB suceimniide), and KTHYL, H(THC 646 (a ram-borαnated PIB succinimide). The dispersant can be combined with other additives used in the lubricant industry to form an additive package for power steering fluid, e.g., LUBR1ZOL 9677MX. and the whole additive package can be used as the dispersing agent.
[00100] Alternatively a surfactant or a mixture of surfactams with low HLB value (typically less than or equal to 8). for example, nordonic, or a mixture of nonkmies and ionics, can be used as the dispersants in the power steering fluid. [00101] The dispersants selected should be soluble or dispersible m the ikμύd medium or additive άiiuem oil. The dispersant can be in a range of up from 0.01 to 30 percent and ail sub-ranges therebetween, for example m a range of from between. 0,5 percent to 20 percent, a range of .from between ) to 1 5 percent, or in a range of from between 2 to 13 percent as active ingredient in the power steering fluid.
VI. Fl.mdizmg A gents
[00102] Floidizing agents are sometimes used in power steering fluids.
Suitable iluidizing agents include oil-soluble diesters. Examples of diesters include the adipates, azelates., and sehacates βf €g4-Y? alkanois (or mixtures thereof), and the. phtliaiates of C4-Cn alkanois (or mixtures thereof). Mixtures of two or more different types of diesters (e.g., dialkyl adipates and diaikyi azelates, etc.) can also be used. Examples of such materials include the ivoctyi, 2-ethylhexyl, isodecyi, and tridecyl diesters of adipic acid. asr.eiaic acid, and sebacie acid, and the α-butyi, isobuiyl, pentyl, hexyl heptyl octyL. nonyl. dccyi, undceyl, dodeeyl, and tridecyl diesters of phthalic acid. Other esters which are used as ilaklizing agents in power steering fluids are polyol esters such as HMHRY 2918, 2.939 and 2995 esters from the EMERY Group of Eleokel Corporation and MATCOL 2926. 2970 and 2999.
VI I. lilic keriers
|00103j Other thickeners, besides viscosity index improvers, which can be used in the power steering fluid include: acrylic polymers such a? polyacrylic acid and sodium high-rao Secular- weight polymers of ethylene oxide such as Poiyox WSR from Union Carbide, cellulose compounds such as earhøxymethylcellulose, polyvinyl alcohol (PVA), polyvinyl pyrrolidoπe (PYP), xantban gums and guar gums, polysaccharides, alkanolaraides, amine salts of polyamide such as DISPARLON AQ series from King Industries, hydrophobicaiiy modified ethylene oxide urethane (e.g. , ACItYSOL series frørn llohϊπax). silicates, and fillers such as mica, silicas, cellulose, wood flour, clays (including organociays) and clays, and resin polymers such as polyvinyl butyral resins, polyuref-hane resins, acrylic resins and epoxy resins.
(1)0104] Other examples of thickeners are polyisβhutyiene, high πiolecuiar weight complex εsier, butyl rubber, olefin copolymers, styrene-diene polymer, polyinethacrylate.. styrεnε-ester, ami ulira high viscosity PAO. An example of a high molecular weight complex ester is Priolube* 3986. To achieve thickening and also impart low traction coefficient properties an ultra high viscosity PAO can also be used in the formulation. As used herein, an "ultra high viscosity PAO'' has a kinematic viscosity between about 150 and LOOO mra'/s or higher at 100"vC. VIII , Frictj on .Modifiers
{003 OS] Friction modifiers are optionally used in power steering fluids.
Suitable friction modifiers include such com pounds as aliphatic amines or ethoxylated aliphatic amines, aliphatic fatty acid amides, aliphatic carboxylic acids, aliphatic carboxylic esters, aliphatic carboxylic ester-amides., aliphatic phosphonai.es, aliphatic phosphates, aliphatic thiophosphonates, aliphatic ihiophosphates, or mixtures thereof. The aliphatic group typically contains at leas! about eight carbon atoms so as to render the compound, suitably oil soluble Also suitable are aliphatic substituted succiniraid.es formed by reacting one or more aliphatic succinic acids or anhydrides with ammonia
[00106] One group of friction modifiers is comprised of the N-aliphatic hydrocarbyl-substiiuted diethanol amines in which the N-aliphatic hydrocarbyl- substituent is at least one straight chain aliphatic bydrocarbyi group free of acetyl eni c unsaturation and having in the range ofaboi.it 14 to about 20 carbon atoms. j'O0tO?j Another group of friction modifiers is comprised of esters of fatty acids, for example C EN W AX™ TGA-185 and glycerol esters of selected fatty acids such as UNIF LEX™ 1803, both made by Arizona Chemical Other fatty acids used as friction .modifiers are mono-oleates such as glycerol mono-oleate, peruaerythruo! mono-oleate. and sorbitan. mono-oleate sold under the tmάmame of RADI ASURF™ by OLEON.
(W)IOS] Friction modifiers will sometimes include a combination of at least one K-aiipbauc hyd.rocarbyl-substiuued diethanoi amine ΆΏU at least one N-aliphatic h ydrocarbyl -substituted triraetbyiεne diamine in which the N-aiiphatic hydrocarbyl- substitueπt is at least one straight chain aliphatic hydrocarbyl group tree of aeetv'lenk ui^saturation and having in the ranue of about 14 to about 20 carbon atoms. Further details concerning this friction modifier combination are set forth in U.S. Patent Nos, 5,372,735 ami 5,441,656.
(00109 j Another example of a mixture of friction modifiers is based on the combination of (i) at bast one di(hydroxyalkyl) aliphatic tertiary amine in which the hydroxyalky! gxoups, being the same or different, each contain from 2 to about 4 carbon atoms, and irs which the aliphatic group is an acyclic hydrocarby) group containing from about 10 to about 25 carbon atoms, and (ii) at least one hydroxyaikyl aliphatic imidazoline in which the hydroxyalkyl group contains from 2 to about 4 carbon atoms, and in which the aliphatic group is an acyclic hydrocarbyl group containing from about 10 to about 25 carbon atoms. Further details concerning this friction modifier system are found in U.S. Paten I No, 5344,579. [00 ϊ .10) Another class of friction modifiers that, is sometimes used in power steering fluids include compounds of the formula: in which Z is a group RI R.2CH-, in which R i and R2 are each independently straight- or branehed-ehain hydrocarbon groups containing from i to 34 carbon atoms and the total number of carbon atoms in the groups Rl and R2 is from i 1 to 35. The radical Z is, for example, 1 - methyl pemadeeyl, 1 -propyl trideeeuyl. 1-pentyUrideeenyl, 1 -iridecenylpeniadecenyl or l-tetxadecykicosenyl. These compounds are commercially available or are made by the application or adaptation of known techniques (see, for example, EP 0 020 037 Ai and LlS Patent Nos. 5,021 ,176, 5,190.680, and RE-34,459). (IHH 111 The use of friction modifiers is optional, However, in applications where friction modifiers are used., the power steering fluid will contain up to about ! .25 weight %, such as from about 0,05 to about I weight % of one or more friction modifiers.
^ X • C'oiTojiρn Jrdii bj tors fθOl 12] Corrosion inhibitors are another class of additives suitable for inclusion in power steering fluids. Such compounds include thiazoies, tnazoles and thiacliazoies.. Examples of such compounds include benzotriazoie, tolyitriazoie, octyltrjazoie, άecyitriazolε, dodecyltiiazole, 2~mercapto henzothiazolε, 2,5- dimercapi53"ls3,44hiadiazole, 2~raercaph3--5~hydroearbyldiio-l,3.4~thiadu5zok-s, 2- mercapto-5- hydrocai'byidithio-l ,3v4-thiadia?.oles, 2,54>is(hydrocarbylthiø)-4 ,3,4-< thiadiazoies. and 2,54>is(hydrocarhykiύhku- ! ,3,4~ihiadia2oies. Corrosion inhibitors of these types that are available on the open market include Cobratec TT- 100 and HITEC* 314 additive and HFfEC* 4313 additive (ETHYL, Petroleum Additives, Inc.).
X. Rust Inhibitors
{00113] Rust inhibitors comprise another type of inhibitor additive. Some rust inhibitors are also corrosion inhibitors. Examples of rust inhibitors useful in power steering fluids are monocarboxylie acids and poly carboxy lie acids, Examples of suitable monocarboxylic acids are oclanoic aeκl decanoic actd and dodecanoic acid. Suitable pυiyearhoxylic acids include di.mer and trirner adds such as are produced from such acids as tail oil fatty acids, cdeie acid, lsnoleic acid, or the like. Products of this type are currently available from various commercial sources, such as. for example, the dimer and trirner acids sold under the HYSTRENE trademark by the ϊ lurøko Chemical Division of Witco Chemical Corporation and under the EMPCJL trademark by Henkei Corporation. Another useful type of rust inhibitor for use Lo power steering fluids is comprised of the alkenyl succinic acid and alkenyl succinic anhydride ooπosion inhibitors such, as, for example, tetrapropeirylsuccmie acid, tetrapropemisuceinie anhydride, teiradeeeivylsuecioie acid, tetr adeeenylsuecinic anhydride , hexadecemisuee; nic acid, hexadecenylsucclnic anhydride, and the like. Also useful are the hall' esters of alkenyl succinic acids having 8 to 2.4 carbon atoms in the alkenyl group with alcohols such as the polyglycols. Another suitable rust inhibitor is a msi .inhibitor comprising a solubility improver having an aniline point less than 100°C; a mixture of amine phosphates; mid an alkenyl succinic compound selected from the group consisting of an acid half ester, an anhydride, an acid, and .mixtures thereof as taught m IJ. S, Patent Application No. 11/257,900, filed on October 25, 2005. Other suitable rust or corrosion inhibitors include ether amines; acid phosphates; amines: poiyethoxyiated compounds such as ethoxylateci amines, ethoxylated phenols, and ethoxylated alcohols; imidazolines; amrnosuccmic acids or derivatives thereof, and She like,
3t> - Materials of these types are available as articles of commerce. Mixtures of rust inhibitors can be used, Xi- Artfiojddams
['00I Wj Suitable antioxidants include phenolic antioxidants, aromatic amine antioxidants, sulfated phenolic antioxidants, hindered phenolic antioxidants, molybdenum containing compounds, zinc dialkyldltbiophosphat.es, and organic phosphites., among others. Mixtures of different types of antioxidants are often used. Examples of phenolic antioxidants include kmoi derived hindered phenols, 2.6-di- tert-butylphenoL liquid mixtures of tertiary butyiated phenols, røethylpheoo! , 4,4'- metby lenebis(2,6-di-tert-butylphenol), 2,2'»rneth ylenebi s(4- niethyi-6-tert-buty I phenol), mixed methylene-bridged polyalkyl phenols, 4.4'- ihIobis(2-metli)i-6-tcrt-bϋtylphenol}, and sterieaiiy hindered tertiary butyiated phenols. N,N'-di-sec-huty}-p-phenylenediami.ne.. 4-tsopropylaminodiphenyl amine, phenyl— naphtbyl amine, phenyl-naphihyl amine, styrersated diphenylamiiiε, and πng-alkylated diphenylamines serve as examples of aromatic amine antioxidants. In an embodiment, the antioxidant is a catalytic antioxidant comprising one or more oil soluble organo metallic corapound(s) and/or orgaπo metallic coordination complexes such as metal(s) or metal cation(s) having mυre than one uxiuation state above the ground state compiexed, bonded or associated with two or more anions, one or more biάentate or tridentate ligands and/or two or more anions and ligand(s), as described in U.S. Patent Application Publication No. 2006/0258549 A l . X! 1 ■ [Mergents
(001 JS) Examples of detergents that cau be used in power steering fluids are over-based metallic detergents, such as the phosphoπate, sulfonate, phenolate or salicylate types as described in Kitk-Othinet Encyclopedia of Chemical Technology, third edition, volume 14, pages 477-526. XIII. Seal Swell Agents
[001.1.6] A number of seal swell agents useful in power steering fluids are described in U.S. Patent Application Publication Nαs. 2003/0 I l 9682 A l and 2007/0057226 A 1 , Examples of seal swell agents are aryl esters, long chain alkyi ether, alky! esters, vegetable based esters, sebacatε esters, sulfhlanes, .substituted suifoiane. other suiibiaαe derivatives, pbeniues, adipates. glyceryl iri(acetαxysteaiate), epoxidized soybean oil. epoxsdized linseed oil N, n -butyl benzene sulfonamide, aliphatic polyurethaϋe, polycsier glutarate, triethyϊene glycol caprat.e/eapry!ates dialkyl diester glutaratε, monoraεπc, polymer, and epσxy plastickers. phthalate pbustieizsrs, such as dioctyl phthalate, dinonly phf.ha.late or dihexylpthaiate. or oxygen-, sulfur-, or nitiOgen-coistaining polyfunctions! mtriles, pheoates, and combinations tliereof. Other piasticizers which can be substituted for and/or used with the above plasticims including glycerine, polyethylene glycol, dibutyl pbthalate, and 2,2,4-trimeιiiy!-] niOBOisobvstyrate, and diisoαoπyi phthalate ail o.f which are soluble in a solvent carrier. Other seal swelling agents such, as LUBRJZOL 730 can also be used, X S V , Aniiwear ;. and/or .Extr erne fte^s^sie Addjt i ves
[00117] Various types of sulfur-containing ami wear and/or extreme pressure additives can be used hi power steering fluids. Examples include dihydrocarbyi polysuliides; sulfurized olefins; sulfurked fatty acid esters of both natural and synthetic origins; trithioaes; suLfurized thienyl derivatives; sulfurixed terpenes: sulfiirized oligomers of CrQ røonoolefins, and sulfur ized Dieis-Aldα adducb huch as those disclosed in U. S, Patent No, R.E-27331 , Specific examples include ϋuifurized polyisobutene, suifurized isobυtylene, suifuπxed diisobutylene. sulfυrized triisobutyleue, dieyclohexyl polysulilde, diphenyl poiysuHϊde, dihetrzyl polysulfide, dinonyl potysuLtkie, and mixtures of di-tert-bυcyi poiysuHϊde such as mixtures of di- tert-butyl trisidfide, di-tert- butyl tetrasislfide and di4ert-butyl peπtasufftde, among others. Combinations of such categories of sulfur-containing antiwear and/or extreme pressure agents can also be used, such as a combination of sulfumed isobαtylene and di-ϊert- butyl trisulfide, a co.ofbinatioπ of sulforized isobutylene and dinonyl trisuϊflde, a combination of sulfuri zed tall oil and dibe.azyl poiysυlfule, [00118} hi the context of this disclosure a component which contains both phosphorus and sulfur in its chemical structure is deemed a phfxsphorus~cont.aining atήiwear and/or extreme pressme agent rather than a sulfur-containing aπtiwear aucl-'or extreme pressure agent.
[Θ0H9] Use can be made of a wide variety of phosphorus-containing oil- soluble anήvvear and/or extreme pressure additives such as the oil-soluble organic phosphates, organic phosphites, organic phosphorates, organic pho≤phonites, etc., and their sulfur analogs. Also useful as the phosphorus-containing antiwear and/or extreme pressure additives that can be used in power steering fluids include those compounds' that corstam both phosphorus and nitrogen, Phosphorus-containing oil- soluble arstiwear and/or extreme pressure additives useful in power steering fluids include those compounds taught in IKS, Patent Nos. 5,464,549, 5,500, 140, and 5,573,696.
[00120] One such type of phosphorus- and oύrogeiv containing ami wear and/or extreme pressure additives which can be used in power steering iiiuds are the phosphorus- and nitrogen-containing compositions of the type described in GB 1 ,009,913, GB 1 ,009,914, U.S. Patent No. 3,197,405 and/or U.S. Patent No. 3,197,496. In general, these compositions are formed by forming an acidic intermediate by the reaction of a hydroxy-substituted tπester of a phosphorotluok acid with an inorganic phosphorus acid, phosphorus oxide or phosphorus halide, and neutralizing a substantial portion of said acidic intermediate with an amine or iiydroxy-substituted amine. Other types of phosphorus- and nitrogen-containing aπthvear and/or extreme pressure additive that can be used in power steering fluids include the amine salts of hydroxy-substituted phosphetanes or the amine salts of hydroxy -substituted thiophosphetanes and the amine salts of partial esters of phosphoric and thiophosphoric acids. ^V. An trfoani Agents
}0ϋI21 \ Antifoam agents work by destabilizing the liquid film that surrounds entrained air bubbles. To be effective they must spread effectively at the air/liquid interlace. According to iheory, the amifbam ageni will spread if the value of the spreading coefficient, S, is positive, S is defined by the following equation:
■^α wherein FJ" is the surface tension of the foamy liquid, P; is the surface tension of the anύfoaxo agent, and P! -" is ύie interfaciai tension between them. Surface tension and mteitaeial tensions are measured using a ring type tensiomeCer by ASlM D 1331-89 (Reapproved 2001 ), "Standard Test Methods foτ Surface and hiterfacial Tension of Solutions of Surface- Active Agents". With respect to the present disclosure, P! is the surface of the power steering fluid prior to the addition of anlifoam agent. [00122 J Examples of antifoam agents are antifbam agents that, when blended into the power steering fluid will exhibit spreading coefficients of at least 2 mN/'m at both 24C'C aid 93.50C. Various types of antifoam agents are taught in U.S. Paient No. 6,090,758. When used, the antifoam agents should not significantly increase die air release ϋme of the power steering fluid, Examples of suitable aotifoam agents are high molecular weight polydiinethyi siloxanc, a type of silicone antifoam agent, acryiate antifoam agents (as they are less likely to adversely effect air release properties compared to lower molecular weight silicone antifoarn agents), polydimethylsiioxan.es and polyethylene glycol ethers and esters, XVI, Cjαlorantg/Dygs
[00123] Colorants or dyes are used to impart color or to fluoresce under particular types of light. Fluorescent dyes facilitate leak detection. Colored oils help distinguish between different products. Examples of these colorants or dyes are anthraquhiones, azo compounds, ϊ.ri phenyl- in ethane-, perylene dye, naphthalimide dye, and mixtures thereof. Particular types of iluorescent dyes are taught in U.S. Patent No, 6,165,384, XVH. Dihient OiI
[00124] Diluent oil is often iused in the different types of additive packages to effectively suspend or dissolve the additives in a liquid medium. In general, the maximum amount of diluent oil in all of the additive packages used to make the power steering fluid should he within 0 to 40 volume %. In an embodiment, the diluent, oil is an extra light hydrocarbon liquid derived from highly paraflinic wax,, described in U.S. Patent Application Publication No. 2006/0201852 Al, wherein the diluent oil has a viscosity of beiwyen about 1.0 mnr/s and. about }.S rnm'V's at I QO0C? and a Noack volatility of less than 50 weight %, and also having greater than 3 weight % molecules with cycϊoparaftlnic nractkmaiUy and less than 0.30 weight percent aromatics.
EXAMFULS
(»0125) The following illustrative examples are intended to be non-limiting.
ExaiD£bJi..£.Q.uation .{"2) jϋϋi26] As disclosed in U.S. Patent Application Publication No,
2006/0201852 Al , a sample of commercial hydrotreated Fischer- Tϊopsch wax made using a Fe -based Fischer-Tropsch synthesis catalyst and a sample of hydxotreattxi Fischer-Tropseh wax made using a Co -based Fisches-Tropseh catalyst were analyzed and found to have the properties shown hi Table 1.
Table I
duplicate tests |0θϊ27j The Fischer-Tropsch wax feeds were hydros somen zed aver a
Pt/SAFO i i catalyst on an alumina binder. Run conditions were a temperature of between 652 and 6950F (344 and 368'"C), liquid hourly space velocity (LHSV) of 0,6 to 1.0 hr' 1, iOOO psig reactor pressure, and a once- through hydrogen rate of between 6 and 7 MSCF/bbl. The reactor effluent passed directly to a second reactor, also at 1000 psig, which contained a Pt/Pd on silica-alumina hydro finishing catalyst. Conditions in that reactor were a temperature of between 425 and 7(3O0F (218 and 3720C)5 and LHSV of LO hrΛ
[00128] The products bosiing above about. 600°F were fractionated by atmospheric or vacuum distillation to produce five fractions having viscosities between about 2,0 and 3.5 πiπrVs at K)O111C. The properties of the five fractions are shown in Table II.
Fabk
f I)Oi 29] The Noack vol aiillty of føiϊr of the fracfions, FT - i , FT~2, FT-3S and FT
5, were each less than an amount calculated by the equation:
IMoack 'Volatility Factor ::: 160 - 40(K.inematic Viscosity at 1000C), (2) .bxampsε 2: houation < j )
|001301 As disclosed in U, S, Pa lent Application Serial No. 1 1 /613,936, three samples of Fischer -Tropseh derived base oil were analyzed and determined to have the following properties:
'Table Il
[00131] The three Fiseher-Tropseh derived base oils were all distillate tractions made by hydroisomerizaϋon devvaxing a hydrotreated (^o- based Fischer- Tropseh wax in a scries of two reactors, hydro finishing die effluent in a single reactor., and vacuum distilling the product into different grades of base oil. Ail three of these Fischer- Tropseh derived base oils had very low aromaties and olefm contents, and had very good oxidation stabilities. Additionally, all three of them had very low Noack volatilities. Note thai only the FT-A had a wt% Noack Volatility less than an amount defined by the equation:
Noack Volatility Factor ::;: (900 x (Kinematic Viscosity ai 100°C)'i 85 - 1 5. (3) The difference between the vvi.% Noack volatility of the light base oil fraction VT-A and the Noack Volatility Factor by Equation (3) of FT-A was greater than 0.5, FT-A also had extremely good oxidation stability and a viscosity index greater than: 28 x ln(Kinematic Viscosity at I CXPC) + 95.
[00132 J As further disclosed in U.S. Patent Application Serial No,
1 1/613,936, hydro treated Co-based Fiseher-Tropsch wax was hydroisomerized over a Pt/SAPO-Ϊ 1 hydroisomerization. catalyst w a series of three reactors at a temperature of 600-70011F, about 1 LHSV feed rate, less than 800 psig pressure, and about 4 to about 20 MSCF/bbi hydrogen flow rate. Following hydroisomerixation, the product was hydrofraished over a Pd/Siiica Alumina hydroimishing catalyst in a series of two hydrofϊmshing reactors at a total pressure greater than 700 psig, a temperature of about 400 to about 6000F, aboui 1 LFI S V feed rate, and about 4 to about 20 MSCF/bbl hydrogen flow rate.
[00133] The products out of the hydrolliiishing reactor were vacuum disϋlled into different base oil grades, one or more fractions having a kinematic viscosity at TOOT! between 1 ,5 m\ύ 3.5 mra"/s. Two of these base oil fractions were analyzed atid determined to have the following ptoperties;
Table IV
100 J 34) Both of these base oils had a wt% Noack volatility between. 0 and
100 and additionally less than an amount defined by the equation:
Noack Volatility Factor :::- (900 x (Kinematic Viscosity at 100'"1C)"2 8) - 15. 0) The difference between the wt% Noack volatilities of the light base oil fractions FT- D and FT-E and their Noack Volatility Factors by Equation (3) were greater than 5. They both had exceptionally good oxidation stabilities, low pour points, and high VIs.
Example 4; Power Steering Fluids
(00135] Two base oils were prepared by hydroisonierization dew-axing a Co- based Fischer-Tropsch wax ami a Fe-based Fischer -Trapscli wax over a Pt/'S APO-I ! catalyst at 1000 psi, 0.5- 1.5 LHSV, and between 660~69CFC. The base oils were subsequently bydrotreεued to reduce ihe level of aromatics and olefins, then vacuum distilled into fractions.
JΘΘO6J The FlMS analysis was conducted on a Microm&ss ϊirne-of-i' light spectrophotometer. The emitter on the Micromass Tirøe-of-Fiight was a €&rbotec 5um emitter designed for FI operadon. A constant How of msu the mass i>pc> iroraotcr \ m a τhιn ..apunin fufcv 1 he probe was heavvά iiom about ^ι)v C up to 6000I." at a MtC υf KKt ( pes rimutc data or t?s.e iwo 1 ISCKT- 1 mpsdj tieπu J lαh;κ<HJi h'Λβe oiK jif , B<ϋ-e Oil U approptuαo for tm; in tlv ρjocml> claimed [H<>w& htcCiJiix fioαs, a>s Vv ell tu> α are sho^n m Table V he! OVi
Fdble. V
(00137) Base Oil L imlikt; the Comparative Base OiU5 has a kinematic viscosity at I0O*C greater than a Viscosity Index factor calculated by the following equation:
28 x Lm'Kmeoiadc Viscosity at 1 QO0C) 4 ] 0 i . (I)
Base Oil 1 , unlike the Comparative Base OiL also has a Noack volatility less than a Noack Volatility Factor calculated by either of the foi lowing equations: 160 - 40(Kinernatic Viscosity at 10OO. (2)
(900 x (Kinematic Viscosity at 100cCV3J) - 15. (3)
As noted above, for kinematic viscosities in the range of 2.4 to 3.8 rmn7s. Equation (3) provides a lower Noack Volatility Factor than does Equation (2). As the kinematic viscosity of Base Oil 1 is 2.18 nmrVs, Equation (3) does not provide a lower Noack Volatility Factor (86,52) than does Equation (2) {72.8} for Base Oil 1 , However, as die kinematic viscosity of the Comparative Base Oil is 2.981 mnr/s, Equation (3) does provide a lower Noack Volatility Factor (27.27) than does Equation (2) (40,76.) for the Comparative Base Oil. However, the T1GA Noack Volatility of the Comparative Base Oil, 48 vvt%, is greater than either 27,27 or 40.76, while the TGΛ Noack Volatility of Base Oil 1 , 67.37 wt%, is less than either 86.52 or 72.8.
1 able Vl
|00138] Fonura Nexbasε 3043 is a conventional API Group I II base oil. The total 1 -to 6- umatur&tions by FiMS for Forturπ Nexbase 3043 is greater than. 55 weight %, and the ratio of moieαsles with monocycloparaffmic functionality to molecules wiih πiulticycioparafβnic functionality is less than 2.0. [00139] ΛU of the publications, patents and patent applications cited herein are herein incorporated by reference in their entirety to the same extent as if the disclosure of each individual publication, patent application or patent was specifically and individually indicated to be incorporated by reference in its entirety, [00140] Many modifications of the exemplary embodiments disclosed herein will readily occur to those of skill in the art. Accordingly, the present disclosiπe is to be construed as including all structure and methods that fail within the scope of the appended claims.

Claims

WHAT ΪS CLAIMED IS:
1. A power steering fluid comprising: a) greater than 50 weight % base oil, wherein the base oil has consecutive numbers of carbon atoms and has a viscosity index greater than a Viscosity Index Factor calculated by the following equation:
28 x ln(Kinematic Viscosity at 1000C) -t 101; and b} viscosity index improver; wherein the power steering fluid has a viscosity index of greater thaα 290 and a Ikoαkfield Viscosity at -400C of less than 1900 oiPa-s.
2. The power steering fluid of claim 1 , further comprising less than about 1 ,0 weight % pour point depressant.
3. The power steering fluid of claim i, wherein the base oil is made from a waxy feed.
4. The power steering fluid of claim I , wherein the base oil has a kinematic viscosity at 1000C between about 1.2 and about 4.0 mnr/s.
5. The power steering fluid of claim I , wherein the base oil has a kinematic viscosity at 1000C between about 1.5 and about 3.5 mnr/s.
6. The power steering fluid of claim 1 , wherein the base oil has greater than 5.0 weight. % molecules with cyclopara.ffϊnic functionaiiry.
7 The power steering fluid of claim 1, wherein the base oil has a ratio of molecules with rnonocyclopamt'finic functionality to .molecules with πiuiticycloparaffmic functionality of greater than 5.
8. The power steering fluid of claim 1 , wherein the base oil has a ratio of molecules with moBocyelαparaffimc functionality to molecules with muitieycloparaffjoic functionality of. greater than H).
9. The power .steering fluid of claim L wherein (he base oil has a ratio of molecules with rnonocycloparallmie functionality Lo molecules with rnultkycϊoparaffϊnic functionality of greater than 15.
10, The power steering fluid of claim 1. wherein the base oil has a ratio of .molecules vviih monocycloparaffrnie functionality k> molecules with niuhicycioparaffinic ibncdonalky of greater than 20.
1 1. The power steering fluid of claim 1 , comprising greater than 70 weight. % base oil.
12, The power steering fluid of claim 1 , comprising viscosity index improver in an amount less than 13 weight %.
13, The power steering fluid of claim 1 , comprising viscosity index improver m an amount ies.s than 12 weight %.
14, The power steering fluid of claim 1 , wherein the power steering fluid comprises approximately 0 weight % pour point depressant.
15. The power steering fluid of claim 1 , wherein the Brookfield Viscosity at. - 40f'C is less than 150O mPa-S.
.16. The power steering fluid of claim K further comprising a detergent-inhibitor additive package.
17. The power steering fluid of dairø 16, comprising 2 to 6 weight 'Ks detergent- inhibitor additive package.
18. The power steering fluid of claim 16, comprising less thas 5 weight % detergent-inhibitor additive package.
19. The power steering fluid of claim 1 , wherein the base oil is Fischer-Trtηxsch derived.
20. The power sieering iiuid of claim L wherein the power steering .fluid meets the requirements of one or more power steering fluid specifications for automotive power steering systems,
2.1. A process for producing the power steering fluid of claim 1 comprising; a) obtaining a base oil Having: i ; a consecutive numbers of carbon atoms;
HjF a viscosity index greater than a Viscosity index Factor calculated by the following equation:
28 x hi{ Kinematic Viscosity at i0U°C) + 101; and b) blending the base oil with viscosity index improver to form the power steering fluid: wherein the power steering fluid co.nipr.ises greater than 50 weight % base oil and has a viscosity index of greater than 290 and a Brookfieki Viscosity at -4O0C of less than 1900 mPa-s.
22. A process for producing a power steering fluid comprising: a) obtaining a base oil having: i) a consecutive numbers of carbon atoms;
- D2 ■ ii) a kinematic viscosity at 100nC of less ihan about 4 mrn7s; and ϊύ) a Noack volatility less than a Noaek Volatility Factor calculated by the following equation:
160 - 40(Kinernatie Viscosity at 1000C).. and b) blending the base oil with viscosity index improver to form the power steering fluid; wherein the power steering fluid comprises greater than 50 weight % base oil and has a viscosity index of greater than 290 and a Broc-kfield Viscosity at -4053C of less than 1900 rnPa-s.
23. 'The process of claim 22, wherein forming a power steering fluid further comprises blending the base oil with pour point depressant, wherein the power steering fluid comprises less than about \ ,0 weight % pour point depressant.
24. The process of claim 22, wherein the base oil has a viscosity index greater than a Viscosity Index Factor calculated by the following equation:
28 x ln(Kinematic Viscosity at 100'-'C) * 101 .
25. The process of claim 22, wherein the base oil has a kinematic viscosity at. 10(FC between about 1.2 and about 4.0 mra'/s,
26. The process of claim 22, wherein the base oil has a kinematic viscosity at 100°C- between about 1.5 arid about 3.5 mrrTϊ's.
27. The process of claim 22, wherein the base oil is Fischer- Tropsch derived.
28. The process of dakrs 22. wherein the base oil has greater than 5.0 weight % nio 1 ee ulcs with eye I oparaffuuc iύπeti oπa i ity .
» \'Ϊ , 29, The process of claim 22, wherein she base oil has a ratio of molecules with rnonoeyclϋparaiϊiuie functionality to molecules with muitkyelopaiafiinie functionality of greater than S,
30, The process of claim 22, wherein the base oil has a ratio of molecules with raotiocycloparaiϊinic functionality to molecules with nuilticydoparaffinic functionaiitv of g Ssr"eater than 10.
31. The process of claim 22, wherein the base oil has a ratio of molecules with monocyeloparaiϊΪBie functionality to molecules with multicyeloparaffimc functional ity of greater than 15.
32. The process of ciairø 22, wherein the base oil has a ratio of molecules with monocycloparaffinie functionality to molecules with iTuihicycloparaffiπic functionah'iy of greater than 20.
33. The process of claim 22, whesem forming a power steering fluid further comprises blending the base oil with a detergenl-inhibitor additive package.
34. The process of eJaira 33, wherein the detergent -inhibitor additive package 5S blended in an amount of 2 to 6 weight %.
35. The process of claim 33, wherein the detergent-inhibitor additive package is blended in an amount of less than 5 weight %.
36. The process of claim 22, wherein the base oil has an aniline point greater than
36 x ln(Kinematic Viscosity at 1 GO0C) *• 200, , The process of claim 22, wherein the base oil has a Noack volatility between 0 and 100. , The process of claim 37, wherein the base oil has a Noack volatility less than a Noack Volatility Factor calculated by the following ecjuaπou:
900 x (Kinematic Viscosity at !00°C}"'2 8 - 15. , A power steering fluid produced by the process of claim 22 comprising: a) greater than 50 weight % base oil wherein the base oil has consecutive numbers of carbon atoms* a kinematic sϊseosity at 1000C' of less than about 4 mm'Vs, and a Noack volatility less than a Noack Volatility Factor calculated by the following equation;
160 - 40{Kinematic Viscosity at 10O0C); and b) viscosity index improver; wherein die power steering fluid has 3 viscosity index, of greater than 290 and a Bκκ>kikid Viscosity at -4O0C of less than 1900 mPa s,
EP08771991A 2007-06-28 2008-06-26 Power steering fluid Withdrawn EP2162520A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11/819,726 US20090005275A1 (en) 2007-06-28 2007-06-28 Power steering fluid
PCT/US2008/068282 WO2009006180A1 (en) 2007-06-28 2008-06-26 Power steering fluid

Publications (1)

Publication Number Publication Date
EP2162520A1 true EP2162520A1 (en) 2010-03-17

Family

ID=39944450

Family Applications (1)

Application Number Title Priority Date Filing Date
EP08771991A Withdrawn EP2162520A1 (en) 2007-06-28 2008-06-26 Power steering fluid

Country Status (7)

Country Link
US (1) US20090005275A1 (en)
EP (1) EP2162520A1 (en)
JP (1) JP2010531921A (en)
CN (1) CN101784647A (en)
BR (1) BRPI0813418A2 (en)
CA (1) CA2691268A1 (en)
WO (1) WO2009006180A1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5591323B2 (en) * 2009-05-01 2014-09-17 シエル・インターナシヨネイル・リサーチ・マーチヤツピイ・ベー・ウイ Functional fluid composition having improved seal swellability
CN102719298B (en) * 2012-06-27 2014-07-30 上海三一重机有限公司 Lubricating oil
CN103666682B (en) * 2013-11-22 2015-10-07 广西大学 Ship side thruster hydraulic oil
US11820952B2 (en) * 2021-01-06 2023-11-21 Vantage Santolubes Research Llc Process to produce low shear strength base oils
JP7648878B2 (en) * 2021-02-26 2025-03-19 横浜ゴム株式会社 Rubber composition for hose and hose

Family Cites Families (52)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3197496A (en) * 1961-08-09 1965-07-27 Lubrizol Corp Polyphosphorus ester derivatives of o, o-dihydrocarbyl-s-hydroxylalkyl phosphorodithioates
US3197405A (en) * 1962-07-09 1965-07-27 Lubrizol Corp Phosphorus-and nitrogen-containing compositions and process for preparing the same
GB1195749A (en) * 1966-12-19 1970-06-24 Lubrizol Corp Sulfur-Containing Cycloaliphatic Reaction Products and their use in Lubricant Compositions
US3773650A (en) * 1971-03-31 1973-11-20 Exxon Co Dewaxing process
US3775288A (en) * 1972-05-26 1973-11-27 Exxon Research Engineering Co Combination of dilution chilling with scraped surface chilling in dewaxing lubricating oils
JPS5624493A (en) * 1979-08-06 1981-03-09 Nippon Oil Co Ltd Central system fluid composition for automobile
US4440871A (en) * 1982-07-26 1984-04-03 Union Carbide Corporation Crystalline silicoaluminophosphates
US4477333A (en) * 1982-09-29 1984-10-16 Exxon Research And Engineering Co. Dewaxing by a combination centrifuge/catalytic process including solvent deoiling
US4673487A (en) * 1984-11-13 1987-06-16 Chevron Research Company Hydrogenation of a hydrocrackate using a hydrofinishing catalyst comprising palladium
US5059299A (en) * 1987-12-18 1991-10-22 Exxon Research And Engineering Company Method for isomerizing wax to lube base oils
US4943672A (en) * 1987-12-18 1990-07-24 Exxon Research And Engineering Company Process for the hydroisomerization of Fischer-Tropsch wax to produce lubricating oil (OP-3403)
US4943424A (en) * 1988-02-12 1990-07-24 Chevron Research Company Synthesis of a crystalline silicoaluminophosphate
US5158665A (en) * 1988-02-12 1992-10-27 Chevron Research And Technology Company Synthesis of a crystalline silicoaluminophosphate
AU623504B2 (en) * 1989-02-17 1992-05-14 Chevron Research And Technology Company Isomerization of waxy lube oils and petroleum waxes using a silicoaluminophosphate molecular sieve catalyst
USRE34459E (en) * 1989-03-20 1993-11-30 Ethyl Petroleum Additives, Limited Friction modifier
US5190680A (en) * 1989-03-20 1993-03-02 Ethyl Petroleum Additives Ltd. Friction modifier comprising a long chain succinimide derivative and long chain acid amide
GB8906345D0 (en) * 1989-03-20 1989-05-04 Ethyl Petroleum Additives Ltd Friction modifier
DE69109927T2 (en) * 1990-03-31 1995-09-28 Tonen Corp Hydraulic fluids for automotive suspensions.
CA2038774C (en) * 1990-04-04 2001-09-25 Eric Herbolzheimer Slurry bubble column
US5348982A (en) * 1990-04-04 1994-09-20 Exxon Research & Engineering Co. Slurry bubble column (C-2391)
US5282958A (en) * 1990-07-20 1994-02-01 Chevron Research And Technology Company Use of modified 5-7 a pore molecular sieves for isomerization of hydrocarbons
US5464549A (en) * 1991-12-12 1995-11-07 Ethyl Corporation Oil soluble dispersants suitable for use in fuels and lubricants
US5344579A (en) * 1993-08-20 1994-09-06 Ethyl Petroleum Additives, Inc. Friction modifier compositions and their use
US5372735A (en) * 1994-02-10 1994-12-13 Ethyl Petroleum Additives, Inc. Automatic transmission fluids and additives therefor
US5441656A (en) * 1994-02-10 1995-08-15 Ethyl Petroleum Additives, Inc. Automatic transmission fluids and additives therefor
WO1996027648A1 (en) * 1995-03-03 1996-09-12 Exxon Research & Engineering Company Power steering fluid with wide performance range
US5573696A (en) * 1995-03-31 1996-11-12 Ethyl Corporation Oil-soluble phosphorus- and nitrogen-containing additives
US5500140A (en) * 1995-03-31 1996-03-19 Ethyl Corporation Oil-soluble phosphorus- and nitrogen-containing additives
DZ2013A1 (en) * 1995-04-07 2002-10-23 Sastech Ltd Catalysts.
US6090758A (en) * 1997-01-07 2000-07-18 Exxon Research And Engineering Co. Method for reducing foaming of lubricating oils
JP2000109876A (en) * 1998-10-09 2000-04-18 Tonen Corp Hydraulic oil composition for shock absorber
US7214648B2 (en) * 1997-08-27 2007-05-08 Ashland Licensing And Intellectual Property, Llc Lubricant and additive formulation
US6165384A (en) * 1997-08-27 2000-12-26 Spectronics Corporation Full spectrum fluorescent dye composition for the optimization of leak detection processes
JP3844892B2 (en) * 1998-10-09 2006-11-15 東燃ゼネラル石油株式会社 Hydraulic fluid composition for shock absorber
US6150577A (en) * 1998-12-30 2000-11-21 Chevron U.S.A., Inc. Method for conversion of waste plastics to lube oil
US6806237B2 (en) * 2001-09-27 2004-10-19 Chevron U.S.A. Inc. Lube base oils with improved stability
RU2301110C2 (en) * 2001-10-25 2007-06-20 Сэсол Текнолоджи (Проприетери) Лимитед Cobalt-based catalysts activation process
US7018525B2 (en) * 2003-10-14 2006-03-28 Chevron U.S.A. Inc. Processes for producing lubricant base oils with optimized branching
US20050077208A1 (en) * 2003-10-14 2005-04-14 Miller Stephen J. Lubricant base oils with optimized branching
US7053254B2 (en) * 2003-11-07 2006-05-30 Chevron U.S.A, Inc. Process for improving the lubricating properties of base oils using a Fischer-Tropsch derived bottoms
US7282134B2 (en) * 2003-12-23 2007-10-16 Chevron Usa, Inc. Process for manufacturing lubricating base oil with high monocycloparaffins and low multicycloparaffins
US7763161B2 (en) * 2003-12-23 2010-07-27 Chevron U.S.A. Inc. Process for making lubricating base oils with high ratio of monocycloparaffins to multicycloparaffins
US7083713B2 (en) * 2003-12-23 2006-08-01 Chevron U.S.A. Inc. Composition of lubricating base oil with high monocycloparaffins and low multicycloparaffins
US7981270B2 (en) * 2005-03-11 2011-07-19 Chevron U.S.A. Inc. Extra light hydrocarbon liquids
GB2439027B (en) * 2005-03-11 2009-10-28 Chevron Usa Inc Extra light hydrocarbon liquids
US7374658B2 (en) * 2005-04-29 2008-05-20 Chevron Corporation Medium speed diesel engine oil
US20060252660A1 (en) * 2005-05-09 2006-11-09 Akhilesh Duggal Hydrolytically stable viscosity index improves
US8030257B2 (en) * 2005-05-13 2011-10-04 Exxonmobil Research And Engineering Company Catalytic antioxidants
US20100144571A1 (en) * 2005-06-29 2010-06-10 Shinichi Shirahama Base oil for hydraulic oil and composition using the same
WO2007044117A2 (en) * 2005-08-04 2007-04-19 Ashland Licensing And Intellectual Property Llc Variable transmission traction fluid composition
US7732386B2 (en) * 2005-10-25 2010-06-08 Chevron U.S.A. Inc. Rust inhibitor for highly paraffinic lubricating base oil
US7846880B2 (en) * 2006-12-20 2010-12-07 Chevron U.S.A. Inc. Light base oil fraction and lubricant having low wt% noack volatility

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2009006180A1 *

Also Published As

Publication number Publication date
US20090005275A1 (en) 2009-01-01
CA2691268A1 (en) 2009-01-08
WO2009006180A1 (en) 2009-01-08
JP2010531921A (en) 2010-09-30
BRPI0813418A2 (en) 2014-12-23
CN101784647A (en) 2010-07-21

Similar Documents

Publication Publication Date Title
US7572361B2 (en) Lubricant blends with low brookfield viscosities
US7273834B2 (en) Lubricant blends with low brookfield viscosities
US7981270B2 (en) Extra light hydrocarbon liquids
US7473345B2 (en) Processes for making lubricant blends with low Brookfield viscosities
US7384536B2 (en) Processes for making lubricant blends with low brookfield viscosities
US7282134B2 (en) Process for manufacturing lubricating base oil with high monocycloparaffins and low multicycloparaffins
US7956018B2 (en) Lubricant composition
AU2004312335B2 (en) Lubricating base oil with high monocycloparaffins and low multicycloparaffins
ZA200605617B (en) Lubricating base oil with high monocycloparaffins and low multicycloparaffins
AU2005245970B2 (en) Lubricant blends with low brookfield viscosities
EP2162520A1 (en) Power steering fluid
AU2006223391B2 (en) Extra light hydrocarbon liquids
EP2970805B1 (en) Use of a group ii oil
US9376642B2 (en) Multi-grade engine oil formulations with improved mini-rotary viscometer results
NL2000332C2 (en) Liquid for a manual transmission prepared with a base lubricating oil with a high content of monocycloparaffins and a low content of multicycloparaffins.
EP2004781A1 (en) A method for reducing deposit formation in lubricant compositions
US9290713B2 (en) Base oil blend upgrading process with a group II base oil to yield improved mini-rotary viscometer results

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20100125

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA MK RS

DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20150106

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230522