`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`
`WORLD INTELLECTUAL PROPERTY ORGANIZATION
`International Bureau
`
`(51) International Patent Classification 6 :
`ClOM 141/10, 163/00 II (ClOM 141/10,
`129:95, 133:52, 135:18, 137:10) (ClOM
`163/00, 129:95, 133:52, 135:18, 137:10,
`159:18, 159:20), ClON 10:02, 10:12,
`30:06, 40:25
`
`Al
`
`(11) International Publication Number:
`
`WO 99/60080
`
`(43) International Publication Date:
`
`25 November 1999 (25.11.99)
`
`(21) International Application Number:
`
`PCT/EP99/03311
`
`(22) International Filing Date:
`
`13 May 1999 (13.05.99)
`
`(81) Designated States: CA, CN, JP, SG, European patent (AT, BE,
`CH, CY, DE, DK, ES, Fl, FR, GB, GR, IE, IT, LU, MC,
`NL, PT, SE).
`
`Published
`With international search report.
`Before the expiration of the time limit for amending the
`claims and to be republished in the event of the receipt of
`amendments.
`
`(30) Priority Data:
`9810581.0
`
`15 May 1998 (15.05.98)
`
`GB
`
`(71) Applicant: INFINEUM USA L.P. [US/US]; 1900 East Linden
`Avenue, P.O. Box 710, Linden, NJ 07036 (US).
`
`(71) Applicant (for GB only):
`INFINEUM UK LTD. [GB/GB];
`Milton Hill, P.O. Box 1, Abingdon OX13 6BB (GB).
`
`(72) Inventors: WALKER, Julia, V.; Infineum UK Ltd., Milton
`Hill, P.O. Box 1, Abingdon, Oxfordshire OX13 6BB (GB).
`GL YDE, Roger; 6 Beam Paddock, Bampton, Oxfordshire
`OX18 6BN (GB). BOYINGTON, Charles, Herbert; Ash(cid:173)
`bourne, Kings Lane, Longcot, Faringdon, Oxfordshire SN7
`7SS (GB).
`
`(74) Agents: BAWDEN, Peter, Charles et al.; Infineum UK Ltd.,
`Law Dept., Milton Hill, P.O. Box 1, Abingdon, Oxfordshire
`OX13 6BB (GB).
`
`(54) Title: LUBRICANT COMPOSITIONS FOR AND THEIR USE IN INTERNAL COMBUSTION ENGINES
`
`(57) Abstract
`
`A low phosphorus lubricant containing a metallocene-catalysed polymer-based dispersant and at least one of copper and molybdenum
`provides fuel economy with maintained wear and oxidation protection.
`
`ORONITE EXHIBIT 1007
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`Page 1 of 33
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`
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`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify St.ates party to the PCT on the front pages of pamphlets publishing international applications under the PCT.
`
`AL
`AM
`AT
`AU
`AZ
`BA
`BB
`BE
`BF
`BG
`BJ
`BR
`BY
`CA
`CF
`CG
`CH
`CI
`CM
`CN
`cu
`CZ
`DE
`DK
`EE
`
`Albania
`Armenia
`Austria
`Australia
`Azerbaijan
`Bosnia and Herzegovina
`Barbados
`Belgium
`Burkina Faso
`Bulgaria
`Benin
`Brazil
`Belarus
`Canada
`Central African Republic
`Congo
`Switzerland
`Cllte d'Ivoire
`Cameroon
`China
`Cuba
`Czech Republic
`Germany
`Denmark
`Estonia
`
`ES
`FI
`FR
`GA
`GB
`GE
`GH
`GN
`GR
`HU
`IE
`IL
`IS
`IT
`JP
`KE
`KG
`KP
`
`KR
`KZ
`LC
`LI
`LK
`LR
`
`Spain
`Finland
`France
`Gabon
`United Kingdom
`Georgia
`Ghana
`Guinea
`Greece
`Hungary
`Ireland
`Israel
`lee land
`Italy
`Japan
`Kenya
`Kyrgyzstan
`Democratic People's
`Republic of Korea
`Republic of Korea
`Kazakstan
`Saint Lucia
`Liechtenstein
`Sri Lanka
`Liberia
`
`LS
`LT
`LU
`LV
`MC
`MD
`MG
`MK
`
`ML
`MN
`MR
`MW
`MX
`NE
`NL
`NO
`NZ
`PL
`PT
`RO
`RU
`SD
`SE
`SG
`
`Lesotho
`Lithuania
`Luxembourg
`Latvia
`Monaco
`Republic of Moldova
`Madagasc,:ir
`The former Yugoslav
`Republic of Macedonia
`Mali
`Mongolia
`Mauritania
`Malawi
`Mexico
`Niger
`Netherlands
`Norway
`New Zealand
`Poland
`Portugal
`Romania
`Russian Federation
`Sudan
`Sweden
`Singapore
`
`SI
`SK
`SN
`sz
`TD
`TG
`TJ
`TM
`TR
`TT
`UA
`UG
`us
`uz
`VN
`YU
`zw
`
`Slovenia
`Slovakia
`Senegal
`Swaziland
`Chad
`Togo
`Tajikistan
`Turkmenistan
`Turkey
`Trinidad and Tobago
`Ukraine
`Uganda
`United States of America
`Uzbekistan
`Viet Nam
`Yugoslavia
`Zimbabwe
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`Page 2 of 33
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`
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`WO 99/60080
`
`PCT/EP99/03311
`
`LUBRICANT COMPOSITIONS FOR AND THEIR USE IN INTERNAL COMBUSTION ENGINES
`
`This invention relates to lubricating compositions,
`
`especially crankcase lubricants for internal combustion
`
`5 engines, more especially those for use in road vehicles.
`
`It
`
`relates in particular to compositions which lead to improved
`
`fuel economy, and especially to compositions that do so while
`
`maintaining the antiwear performance of the lubricating
`
`composition, its resistance to oxidation, or both.
`
`10
`
`International Application WO 96/06904 describes a
`
`lubricant comprising a molybdenum compound, a zinc
`
`dialkyldithiophosphate (hereinafter ZDDP), a sulphur
`
`compound, an ashless dispersant, and a boron compound. The
`
`ashless dispersant is advantageously a reaction product of a
`
`15 polyisobutylene succinic acid with a polyamine, and this may
`
`be borated to combine the ashless dispersant with the boron
`
`compound. An alternative backbone for the ashless dispersant
`
`is an ethylene-a-olefin copolymer. The sulphur compound may
`
`be, for example, a copper, zinc, or nickel
`
`20 dialkyldithiocarbamate. The lubricant gives sustained fuel
`
`economy.
`
`EP-A-770 668 describes a lubricant containing ZDDP, a
`
`copper carboxylate, and a molybdenum salt, optio~~::y
`
`together with an optionally borated ashless dispersant,
`
`25 alkenylsuccinimides being given as examples of the latter.
`
`The lubricant is said to retain its friction-reducing
`
`properties after long use.
`
`EP-A-353 935 describes the use in a lubricating oil
`
`composition of an ashless dispersant derived from an
`
`30 ethylene-a-olefin copolymer obtained by metalloce~e/alumoxane
`
`catalysed polymerization, the copolymer being characterized
`
`by having at least 30% terminal ethenylidene unsaturation.
`
`The dispersant is obtained by reaction with an e~hylenically
`
`unsaturated acid or anhydride, e.g., maleic anhyd~ide, and
`
`CONFIRMATION COP(
`
`Page 3 of 33
`
`
`
`WO 99/60080
`
`PCT/EP99/0331 l
`
`2
`
`the resulting acidic groups reacted with, for example, a
`
`polyamine. The composition may contain, inter aliar ZDDP and
`
`copper and molybdenum compounds.
`
`While the use of ZDDP's or other dihydrocarbyl
`
`5 dithiophosphate salts as anti-wear agents and antioxidants is
`
`common, it has been found that the phosphorus in such
`
`materials has a harmful effect on catalytic converters and
`
`for this and other reasons it is desirable to minimize the
`
`proportions of such materials so far as possible consistent
`
`10 with maintaining the desired properties of the lubricating
`
`composition.
`
`The present invention provides a lubricant composition
`
`comprising a lubricating base stock, a dispersant, a metal
`
`dihydrocarbyl dithiophosphate, and either a copper-containing
`
`15 compound or a molybdenum-containing compound, the composition
`
`comprising at most 0.1% by weight of phosphorus, and the
`
`dispersant comprising a hydrocarbon polymer carrying a
`
`functional group, the polymer comprising monomeric units
`
`derived from ethylene and from at least one a-olefin having
`
`20
`
`from 3 to 16 carbon atoms, ethylene-derived units
`
`representing from 1 to 50% by weight of the polymer, the
`
`number average molecular weight of the polymer being from
`
`1500 to 10000, and at least 30% of the polymer chains having
`
`terminal ethenylidene unsaturation before reaction to add the
`
`25 functional group.
`
`Advantageously, the phosphorus content of the
`
`composition is at most 0.08% and preferably it is at most
`
`0.06%, more preferably at most 0.05%, by weight of the
`
`composition.
`
`30
`
`Advantageously the a-olefin from which the hydrocarbon
`
`polymer of the dispersant is derived is an alkene, preferably
`
`propene or butene (iso- or, preferably, n-). Advantageously
`
`the ethylene conte~~ is from 15 to 50%, preferably 20 to 40%,
`
`by weight of the pc~:,~er. Advantageously, the molecular
`
`Page 4 of 33
`
`
`
`WO 99/60080
`
`PCT /EP99/033 ll
`
`3
`
`weight of the polymer is from 1500 to 4500, preferably from
`
`1800 to 3500. The molecular weight may be measured by gel
`
`permeation chromatography.
`
`As used herein, the term "terminal unsaturation" is the
`
`5 unsaturation provided by the last monomer unit located in the
`
`polymer. Advantageously at least 50%, and preferably at
`
`least 60%, and most preferably from 75 to 95%, of the polymer
`
`chains contain terminal ethenylidene unsaturation. The
`
`above-mentioned EP-A-353 935 describes a process for the
`
`10 manufacture of such polymers, and processes by which they may
`
`be provided with functional groups, and its entire disclosure
`
`is incorporated by reference herein. The polymers may be
`
`by various polymerization processes using
`
`metallocene catalysts which are, for example, bulky ligand
`
`15 transition metal compounds of the formula:
`
`[L]n,M[Aln
`
`where Lis a bulky ligand; A is a leaving group, Mis a
`
`20
`
`transition metal, and m and n are such that the total ligand
`
`valency corresponds to the transition metal valency.
`
`Preferably the catalyst is four co-ordinate such that the
`
`compound is ionizable to a 1+ valency state.
`
`The ligands Land A may be bridged to each other and if
`
`25
`
`two ligands A and/or Lare present they may be bridged. The
`
`metallocene compound may be a full sandwich compound having
`
`two or more ligands L which may be cyclopentadienyl ligands
`
`or cyclopentadienyl-derived ligands, or they may be half
`
`sandwich compounds having one such ligand L. The ligand may
`
`30 be mono- or polynuclear or any other ligand capable of
`
`appropriate bonding to the transition metal, which may be one
`
`or more Group 4, 5 or 6 transition, lanthanide or antinide
`
`metals, with zirconium, titanium and hafnium being
`
`particularly preferred.
`
`Page 5 of 33
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`
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`W099/60080
`
`PCT /EP99/03311
`
`4
`
`The ligands may be substituted or unsubstituted, and
`
`mono-, di-, tri-, tetra- and penta-substitutions of the
`
`cyclopentadienyl ring are possible. Optionally the
`
`substituent(s) may act as one or more bridges between the
`
`5
`
`ligands and/or leaving groups and/or transition metal. Such
`
`bridges typically comprise one or more of a carbon,
`
`germanium, silicon, phosphorus or nitrogen atom-containing
`
`radical, and preferably the bridge places a one atom link
`
`between the entities being bridged, although that atom may
`
`10 and often does carry other substituents.
`
`The metallocene may also contain a further di
`
`aceable
`
`ligand, preferably displaced by a cocatalyst -
`
`a leaving
`
`group -
`
`that is usually selected from a wide variety of
`
`hydrocarbyl groups and halogens.
`
`15
`
`Such polymerizations, catalysts, and cocatalysts or
`
`activators are described, for example, in U.S. Patents Nos.
`
`4 530 914, 4 665 208, 4 808 561, 4 871 705, 4 897 455,
`
`4 937 299, 4 952 716, 5 017 714, 5 055 438, 5 057 475,
`
`5 064 802, 5 096 867, 5 120 867, 5 124 418, 5 153 157,
`
`20 5 198 401, 5 227 440 and 5 241 025; EP-A-129 368, 277 003,
`
`227 004, 420 436 and 520 732;
`
`and WO 91/04257, 92/00333,
`
`93/08199, 93/08221, 94/07928 and 94/13715, the disclosures of
`
`all of which are incorporated herein by reference.
`
`The oil soluble polymeric hydrocarbon backbone may be
`
`25 functionalized to incorporate a functional group into the
`
`backbone of the polymer, or as one or more groups pendant
`
`from the polymer backbone. The functional group typically
`
`will be polar and contain one or more hetero atoms such as
`
`P, O, S, N, B or Hal.
`
`It may be attached to a saturated
`
`30 hydrocarbon part of the oil soluble polymeric hydrocarbon
`
`backbone by a substitution reaction or to an olefinic portion
`
`by an addition or cycloaddition reaction. Alternatively, the
`
`functional group may be incorporated into the polymer in
`
`Page 6 of 33
`
`
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`WO 99/60080
`
`PCT/EP99/03311
`
`5
`
`conjunction with oxidation or cleavage of the polymer chain
`
`end (e.g., as in ozonolysis).
`
`As preferred examples of providing functionality, there
`
`may be mentioned more especially the "ene" reaction with
`
`5 unsaturated mono or dicarboxylic acids or anhydrides,
`
`especially maleic anhydride, followed by reaction of the
`
`carboxylic group or groups with a nucleophilic reactant, for
`
`example, an alcohol, including a polyol, aminoalcohol,
`
`reactive metal compound or, especially, an amine, preferably
`
`10 a polyamine. As polyamine, there is advantageously used an
`
`alkylene polyamine, including a polyalkylene polyamine, for
`
`example a compound of the formula
`
`NH 2 (alkylene-NA)nalkyleneNH:
`
`15
`
`wherein A represents hydrogen or an alkyl group,
`
`advantageously one with at most three carbon atoms, and n has
`
`an average value of from 1 to 10, preferably at least 3, and
`
`more preferably from 3 to 6. The alkylene group is
`
`20 advantageously ethylene.
`
`Functionality may be provided by other means, for
`
`example, by oxidation, hydroformylation, epoxidation,
`
`reaction with a hydroxyaromatic compound or by the Koch
`
`reaction. Provision of functionality by the Koch reaction is
`
`25 described in International Application No. WO 94/13709, the
`
`entire disclosure of which is incorporated herein by
`
`reference. According to the procedure described in the
`
`International Application, a terminal ethenylidene group is
`
`treated with carbon monoxide in the presence of an acid
`
`30 catalyst and a nucleophilic trapping agent, and the resulting
`
`acidic group subsequently treated, 2s described above, by a
`
`nucleophilic reactant, the preferred reactant being a
`
`polyamine, and most preferably ones~ the formula given
`
`above.
`
`Page 7 of 33
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`
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`W099/60080
`
`PCT/EP99/033I I
`
`6
`
`The resultant dispersant may be post-treated with
`
`further reactants, for example, urea, thiourea, carbon
`
`disulphide, aldehydes, ketones, carboxylic acids or
`
`anhydrides, nitrides, epoxides, phosphorus compounds or, more
`
`5 especially, boron compounds. The preferred amine-terminated
`
`ashless dispersant is preferably treated with, for example, a
`
`boron oxide, acid, or halide to provide a borated dispersant
`
`which advantageously contains from 0.05 to 2.0, preferably
`
`0.05 to 0.7, % by weight boron.
`
`10
`
`The dispersant is advantageously present in a proportion
`
`of 0.1 to 20, preferably 1 to 8, % by weight of the
`
`composition.
`
`The base stock may comprise natural or synthetic oils,
`
`or mixtures of natural and synthetic oils. As synthetic base
`
`15 stock there may be mentioned esters, especially alkyl esters
`
`of mono and polycarboxylic acids, monocarboxylic esters of
`
`polyols, and complex esters, poly a-olefins, including
`
`polybutenes, alkylbenzenes, phosphate esters and polysilicone
`
`oils. Natural base stocks, within Groups I, II, and III of
`
`20
`
`the API EOLCS 1509 definition, include mineral lubricating
`
`oils which may vary widely as to their crude source, for
`
`example, as to whether they are paraffinic, naphthenic,
`
`mixed, :~ paraffinic-naphthenic, as well as to the method
`
`used in their production, for example, their distillation
`
`25 range and whether they are straight run or cracked,
`
`hydrofined, or solvent extracted. Also used may be Group IV
`
`and Group V base stocks.
`
`The lubricating oil base stock mixture conveniently has
`
`a viscosity of 2 to 50, advantageously 2.5 to 12, est, or
`
`30 mm 2/s, and preferably 3.5 to 9 est., or mm2 /s, at 100°C, the
`
`actual value depending on the lubricant grade being
`
`manufactured.
`
`~~ metal dihydrocarbyl dithiophosphates, there may be
`
`mentic~ed more especially those where the metals are alkali
`
`Page 8 of 33
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`
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`WO 99/60080
`
`PCT/EP99/03311
`
`7
`
`metals, alkaline earth metals, magnesium, aluminium, lead,
`
`tin, molybdenum, manganese, nickel, copper and,
`
`advantageously, zinc.
`
`The compound may advantageously be employed in a
`
`5 proportion of from 0.1 to 10, preferably 0.2 to 2, wt.%,
`
`based upon the total weight of the lubricating oil
`
`composition provided the maximum phosphorus level is not
`
`exceeded. It may be prepared in accordance with known
`
`techniques by first forming a dihydrocarbyl dithiophosphoric
`
`10 acid (DDPA), usually by reaction of one or more alcohols or
`
`alkyl phenols with P2Ss and then neutralizing the DDPA formed
`with an appropriate metal, especially a zinc, compound. The
`
`dihydrocarbyl dithiophosphates may be made from mixed DDPA
`
`which in turn may be made from mixed alcohols.
`
`15 Alternatively, individual dihydrocarbyl dithiophosphates may
`
`be made and subsequently mixed.
`
`For certain uses, it may be advantageous to make the
`
`DDPA from either primary or secondary alcohols, or a mixture
`
`of primary and secondary alcohols. At least 50 mole% of the
`
`20 alcohols used to introduce hydrocarbyl groups into the
`
`dithiophosphoric acids are advantageously secondary alcohols.
`
`Thus the dihydrocarbyl dithiophosphoric acid may be made by
`
`reacting mixtures of primary and secondary alcohols.
`
`Alternatively, individual dithiophosphoric acids may be
`
`25 prepared with the hydrocarbyl groups on one secondary and the
`
`hydrocarbyl groups on the other primary. To make the metal
`
`compound any basic or neutral compound, especially a zinc
`
`compound, may be used but the oxides, hydroxides and
`
`carbonates are most generally employed. Commercial additives
`
`30 frequently contain an excess of zinc due to use of an excess
`
`of the basic zinc compound in the neutralization reaction.
`
`The preferred zinc dihydrocarbyl dithiophosphates are
`
`oil soluble salts of dihydrocarbyl dithiophosphoric acids
`
`represented by the general formula ( (RO) (RiO) P (S) SJ 2 Zn wherein
`
`Page 9 of 33
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`
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`WO 99/60080
`
`PCT/EP99/03311
`
`8
`
`Rand R1 which may be the same or different are hydrocarbyl
`
`radicals containing from 1 to 18, preferably 2 to 12, carbon
`
`atoms. Examples of such radicals are alkyl, alkenyl, aryl,
`
`aralkyl, alkaryl and cycloaliphatic radicals, optionally
`
`5 substituted, provided the essentially hydrocarbyl nature is
`
`retained. Particularly preferred as Rand R1 groups are alkyl
`
`groups of 2 to 8 carbon atoms. The radicals may accordingly
`
`be, for example, ethyl, n-propyl, i-propyl, n-butyl, i-butyl,
`
`sec-butyl, amyl, n-hexyl, i-hexy~, n-octyl, i-octyl,
`
`10 2 ethylhexyl, nonyl, decyl, dodecyl, octadecyl, phenyl,
`
`butylphenyl, methylcyclopentyl, cyclohexyl, propenyl,
`
`butenyl, and 2-hydroxy-4-methylpentyl. In order to obtain oil
`
`solubility, the total number of carbon atoms (i.e. Rand R1
`
`)
`
`in the dithiophosphoric acid is advantageously at least 5.
`
`15 The zinc dihydrocarbyl dithiophosphate is advantageously a
`
`zinc dialkyl dithiophosphate.
`
`As indicated above, it is in accordance with the present
`
`invention to employ either copper compounds or molybdenum
`
`compounds in the composition.
`
`It is preferred, however, to
`
`20 employ both molybdenum compounds and copper compounds, and it
`
`is within the scope of the invention to employ mixtures of
`
`one or more copper compounds and one or more molybdenum
`
`compounds.
`
`The copper and molybdenum are both present in oil-
`
`25 soluble form though they may be added in oil-insoluble form
`
`provided that in the final composition they are in oil(cid:173)
`
`soluble form. The term "oil-soluble form" does not require
`
`solubility in oil in all proportions; rather the component is
`
`in oil-soluble form if it is soluble or colloidally
`
`30 dispersible to an extent sufficient to have its intended
`
`effect in the environment where the lubricant is to be
`
`employed. Oil-soluble form may be achieved by resort to
`
`solubility aids. Inclusion of further additives may also
`
`promote the solution or dispersion of the com~~nent.
`
`Page 10 of 33
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`W099/60080
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`PCT/EP99/03311
`
`9
`
`The amount of added copper in the compositions of the
`
`invention is preferably at least 2 ppm by weight of elemental
`
`copper. The amount of added copper advantageously does not
`
`exceed 500 ppm, and preferably does not exceed 200 ppm.
`
`5 Especially advantageous compositions have copper in the range
`
`of from 2 to 100 ppm, preferably 50 to 100 ppm and especially
`
`about 80 ppm.
`
`The term "added copper" is intended to exclude copper
`
`present in the oil as a result of accumulation of copper in
`
`10
`
`the oil during use, for example, as the result of wear or
`
`corrosion of copper-containing parts.
`
`The added copper is advantageously in the form of an
`
`oil soluble copper compound. The copper compound may be in
`
`cuprous or, preferably, cupric form. Examples of suitable
`
`15 oil soluble copper compounds include the oil-soluble copper
`
`compounds disclosed in EP-A- Nos. 24 146, 280 579 and 280
`
`580, the disclosures of all of which are incorporated herein
`
`by reference. For example, the added copper may be blended
`
`into the oil as an oil-soluble copper salt of a synthetic or
`
`20 natural carboxylic acid. Examples of carboxylic acids from
`which suitable copper salts may be derived include C2 to
`saturated carboxyli=, especially fatty, acids (e.g., acetic,
`
`stearic and palmi::= acids), unsaturated acids (e.g., oleic
`
`acid), branched carboxylic acids (e.g., naphthenic acids of
`
`25 molecular weight of from 200 to 500, neodecanoic acid and 2
`
`ethylhexanoic acid), and alkyl-or alkenyl-substituted
`
`dicarboxylic acids (e.g., alkenyl-substituted succinic acids,
`
`for example, octadecenyl, dodecenyl and polyisobutenyl
`
`succinic acids). In some cases, suitable compounds may be
`
`30 derived from an a=id anhydride, for example, from a
`
`substituted succinic anhydride. The preferred acids are
`
`polyalkenyl succinic acids in which the alkenyl group has a
`
`number average mo~ecular weight (Mn) greater than 700. The
`
`Page 11 of 33
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`
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`WO 99/60080
`
`PCT /EP99/033 ll
`
`10
`
`alkenyl group desirably has a Mn from 900 to 1,400, and up to
`
`2,500, with a Mn of about 950 being most preferred.
`
`The added copper may be a copper dithiocarbamate of the
`general formula (RR 1NCSS)mCu or a copper dithiophosphate of
`the general formula [ (RO) (R10) P ( S) S] mCu, where "m" is 1 or 2
`and each of Rand R1
`, which may be the same or different,
`
`5
`
`represents a hydrocarbyl radical containing 1 to 18,
`
`preferably 2 to 12, carbon atoms, for example, an alkyl,
`
`alkenyl, aryl, aralkyl, alkaryl, or cycloalkyl radical. If a
`
`10 copper DDP is used, its phosphorus content must be taken into
`
`account;
`
`such compounds are accordingly not preferred.
`
`Other copper- and sulphur-containing compounds, for example,
`
`copper mercaptides, xanthates and thioxanthates, are also
`
`suitable, as are copper sulphonates, phenates (optionally
`
`15 sulphurized) and acetylacetonates.
`
`Other copper compounds which may be used are overbased
`
`materials that contain copper. Examples of such compounds,
`
`and of processes for their preparation, are given in U.S.
`
`Patent No. 4 664 822 and EP-A-425 367, the disclosures of
`
`20 both of which are incorporated herein by reference. In the
`
`preparative processes described in the U.S. specification,
`
`the copper is used in an essentially oil-insoluble form, for
`
`example as the chloride, sulphate or C1 to C6 carboxylate, but
`
`in the overbased product the copper is incorporated into a
`
`25 colloidally dispersed material in such a way that the product
`
`can act as an antioxidant for a lubricating composition. The
`European specification describes the use of copper C7 to C10
`carboxylates which are partially soluble in hydrocarbons so
`
`that in the overbased product they are situated at the
`
`30
`
`interface of the base oil and colloidally dispersed micelles.
`
`If molybdenum is present, the composition advantageously
`
`contains at least 2 ppm of elemental molybdenum by weight.
`
`The proportion is advantageously at most 500 ppm, and
`
`Page 12 of 33
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`WO 99/60080
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`PCT/EP99/03311
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`11
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`preferably at most 400 ppm. Especially preferred compositions
`
`contain from 50 to 350 ppm, especially about 250 ppm.
`
`The molybdenum may be used in any available oxidation
`
`state. The molybdenum may be present as a cation, but this is
`
`5 not essential. Thus, for example, molybdenum-containing
`
`complexes may be used.
`
`Examples of molybdenum compounds which may be used
`
`include the molybdenum salts of inorganic and organic acids
`
`(see, for example, U.S. Patent No.4 705 641), particularly
`
`10 molybdenum salts of monocarboxylic acids having from 1 to 50,
`
`preferably 8 to 18, carbon atoms, for example, molybdenum
`
`octanoate (preferably 2-ethylhexanoate), naphthenate or
`
`stearate; the reaction product of molybdenum trioxide,
`
`molybdic acid or an alkali metal salt thereof (or the
`
`15 reaction product of such a molybdenum compound and a reducing
`
`agent) and a secondary amine having hydrocarbon groups having
`
`6 to 24 carbon atoms (see EP-A-205 165); overbased
`
`molybdenum-containing complexes as disclosed in EP-A-404 650,
`
`molybdenum dithiocarbamates and, less preferred because of
`
`20
`
`their phosphorus content, molybdenum dithiophosphates; oil
`
`soluble molybdenum compounds as disclosed in U.S Patents Nos.
`
`4 995 996 and 4 966 719, particularly the molybdenum
`
`xanthates and thioxanthates described in those
`
`specifications; and oil-soluble molybdenum and sulphur-
`
`25 containing complexes. Specific examples of molybdenum- and
`
`sulphur-containing complexes are those prepared by reacting
`
`an acidic molybdenum compound with a basic nitrogen(cid:173)
`
`containing substance and then with a sulphur source (see, for
`
`example, GB-A-2 097 422), and those prepared by reacting a
`
`30
`
`triglyceride with a basic nitrogen compound to form a
`
`reaction product, reacting the reaction product with an
`
`acidic molybdenum compound to form an intermediate reaction
`
`product, and reacting the intermediate reaction product with
`
`a sulphur-containing compound (see, for example,
`
`Page 13 of 33
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`W099/60080
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`PCT/EP99/03311
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`12
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`GB-A-2 220 954). Other examples of molybdenum compounds are
`
`described in co-pending International Patent Application No.
`
`PCT/IB97/01656 and comprise a trinuclear molybdenum core,
`
`optionally containing non-metallic atoms consisting wholly or
`
`5 partly of sulphur, and bonded thereto ligands capable of
`
`rendering the compound oil-soluble or oil-dispersible. The
`
`compounds may be represented by the general formula Mo 3 SkLp.
`
`wherein
`
`L represents a ligand for example dithiocarbamate
`
`10
`
`pis in the range from 1 to 4 and
`
`k is at least 4, especially 4 to 10, preferably 4 to 7.
`
`The disclosures of all the specifications referred to in this
`
`paragraph are incorporated herein by reference.
`
`15
`
`The mass ratio of added copper to molybdenum if both are
`
`present is advantageously in the range of from 10:1 to 1:10,
`
`preferably 3:1 to 1:3; and especially 2:1 to 1:2.
`
`Further additives may be incorporated in the composition
`
`to enable it to meet particular requirements. Examples of
`
`20 additives which may be included are viscosity index
`
`improvers, corrosion inhibitors, detergents, metal rust
`
`inhibitors, pour point depressants, anti foaming agents and
`
`other dispersants, anti-wear agents, oxidation inhibitors or
`
`antioxidants, and friction modifiers.
`
`25
`
`Viscosity index improvers (or viscosity modifiers)
`
`impart high and low temperature operability to a lubricating
`
`oil and permit it to remain shear stable at elevated
`
`temperatures and also exhibit acceptable viscosity or
`
`fluidity at low temperatures. Suitable compounds for use as
`
`30 viscosity modifiers are generally high molecular weight
`
`hydrocarbon polymers, including polyesters, and viscosity
`
`index improver dispersants, which function as dispersants as
`
`well as viscosity index imprcvers. Oil-soluble viscosity
`
`modifying polymers generally ~ave weight average molecular
`
`Page 14 of 33
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`13
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`weights of from about 10,000 to 1,000,000, preferably 20,000
`
`to 500,000, as determined by gel permeation chromatography or
`
`light scattering methods.
`
`Corrosion inhibitors reduce the degradation of metallic
`
`5 parts contacted by the lubricating oil composition.
`
`Thiadiazoles, for example those disclosed in US Patents Nos.
`
`2 719 125, 2 719 126 and 3 087 932, are examples of corrosion
`
`inhibitors for lubricating oils.
`
`Oxidation inhibitors, or antioxidants, reduce the
`
`10
`
`tendency of mineral oils to deteriorate in service, evidence
`
`of such deterioration being, for example, the production of
`
`varnish-like deposits on metal surfaces and of sludge, and
`
`viscosity increase. Suitable oxidation inhibitors include
`
`sulphurized alkyl phenols and alkali or alkaline earth metal
`
`15 salts thereof; diphenylamines; phenyl-naphthylamines; and
`
`phosphosulphurized or sulphurized hydrocarbons.
`
`Friction modifiers and fuel economy agents which are
`
`compatible with the other ingredients of the final oil may
`
`also be included. Examples of such materials are glyceryl
`
`20 monoesters of higher fatty acids, esters of long chain
`
`polycarboxylic acids with diols, and oxazoline compounds.
`
`A viscosity index improver dispersant functions both as
`
`a viscosity index improver and as a dispersant. Examples of
`
`viscosity index improver dispersants suitable for use in
`
`25
`
`lubricating compositions include reaction products of amines,
`
`for example polyamines, with a hydrocarbyl-substituted mono(cid:173)
`
`or dicarboxylic acid in which the hydrocarbyl substituent
`
`comprises a chain of sufficient length to impart viscosity
`
`index improving properties to the compounds.
`
`30
`
`Detergents and metal rust inhibitors include the metal
`
`salts, which may be overbased, of sulphonic acids, alkyl
`
`phenols, sulphurized alkyl phenols, alkyl salicylic acids,
`
`thiophosphonic acids, naphthenic acids, and other oil-soluble
`
`~ono- and dicarboxylic acids. Representative examples of
`
`Page 15 of 33
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`WO 99/60080
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`PCT/EP99/03311
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`14
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`detergents/rust inhibitors, and their methods of preparation,
`
`are given in EP-A-20S 560.
`
`Pour point depressants, otherwise known as lube oil flow
`
`improvers, lower the minimum temperature at which the fluid
`
`5 will flow or can be poured. Such additives are well known.
`
`Foam control may be provided by an antifoamant of the
`
`polysiloxane type, for example, silicone oil or polydimethyl
`
`siloxane.
`
`Some of the above-mentioned additives may provide a
`
`10 multiplicity of effects; thus for example, a single additive
`
`may act as a dispersant-oxidation inhibitor. This approach
`
`is well known and need not be further elaborated herein.
`
`When lubricating compositions contain one or more of the
`
`above-mentioned additives, each additive is typically blended
`
`15
`
`into the base stock in an amount which enables the additive
`
`to provide its desired function. Representative effective
`
`amounts of additives, including those essential to the
`
`invention, when used in crankcase lubricants, are as follows:
`
`Additive
`
`Viscosity Modifier
`
`Corrosion Inhibitor
`
`Oxidation Inhibitor
`
`Friction Modifier
`
`Dispersant
`
`Detergents/rust inhibitors
`
`Anti-wear Agent
`
`Pour Point Depressant
`
`Anti-Foaming Agent
`
`Mineral or Synthetic
`
`Base Stock
`
`20
`
`* Mass % a. i. *
`Mass % a.i.
`(Preferred)
`
`(Broad)
`
`0.01-6
`
`0.01 5
`
`0.01-5
`
`0.01-5
`
`0.1 20
`
`0.01-6
`
`0.01-6
`
`0.01-5
`
`0.001-3
`
`Balance
`
`0.01-4
`
`0.01 1. 5
`
`0.01-1.5
`
`0.01-1.5
`
`0.1
`
`8
`
`0.01-3
`
`0.01-4
`
`0.01-1.5
`
`0.001-0.15
`
`Balance
`
`* Mass% active ingredient based on the final oil.
`
`Page 16 of 33
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`WO 99/60080
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`PCT /EP99/03311
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`15
`
`It will be understood that the various components o'f the
`
`composition, the essential components as well as the optional
`
`and customary components, may react under the conditions of
`
`formulation, storage, or use, and that the invention also
`
`5 provides the product obtainable or obtained as a result of
`
`any such reaction.
`
`The invention also provides the use, in a crankcase
`
`lubricant, of a dispersant comprising a hydrocarbon polymer
`
`carrying a functional group, the polymer comprising monomeric
`
`10 units derived from ethylene and from at least one a-olefin
`
`having from 3 to 16 carbon atoms, ethylene-derived units
`
`representing from 1 to 50% by weight of the polymer, the
`
`number average molecular weight being from 1500 to 10000, and
`
`at least 30% of the polymer chains having terminal
`
`15 ethenylidene unsaturation before reaction to add the
`
`functional group, to improve fuel economy.
`
`The invention further provides the use, in a crankcase
`
`lubricant containing at most 0.1% by weight of phosphorus, of
`
`a dispersant as defined above, a copper-containing compound
`
`20 or a molybdenum-containing compound, to improve fuel economy
`
`while maintaining wear and oxidation resistance.
`
`Advantageously, the lubricant comprises both copper and
`
`molybdenum compounds.
`
`The invention further provides an additive concentrate
`
`25 comprising a dispersant as defined above, a copper-containing
`
`compound and/or a molybdenum-containing compound and a metal
`
`dihydrocarbyl dithiophosphate, and an oil or a solvent
`
`miscible with an oil, the proportions of the components being
`
`such that when the concentrate is incorporated in a lubricant
`
`30 composition at a treat rate sufficient for the specified
`
`active components to carry out their functions effectively
`
`the proportion of phosphorus is at most 0.1% by weight of the
`
`lubricant compositio