WO2008110612A2

WO2008110612A2 - Novel compounds and lubricating compositions comprising the same

Info

Publication number: WO2008110612A2
Application number: PCT/EP2008/053041
Authority: WO
Inventors: Kiyoshi Hanyuda; Eiji Nagatomi; Noriaka Shinoda
Original assignee: Shell Internationale Research Maatschappij B.V.
Priority date: 2007-03-13
Filing date: 2008-03-13
Publication date: 2008-09-18
Also published as: JP5185549B2; WO2008110612A3; WO2008110612A8; JP2008222639A; AR065841A1; CL2008000678A1

Abstract

The present invention provides novel compounds which contain no zinc or phosphorus components for use in lubricating compositions, e.g. for replacing ZnDTP. To this end the present invention provides a compound having the general formula (1), wherein R1 and R2 are independently hydrogen and/or a linear or branched chain, saturated or unsaturated hydrocarbon moiety with from 1 to 30 carbon atoms or a substituted hydrocarbon moiety, including substitutions where one or more of these hydrocarbon moieties have been substituted with hetero-atoms; wherein the total number of carbon atoms of R1 and R2 is not more than 40; and wherein X is oxygen or sulphur.

Description

NOVEL COMPOUNDS AND LUBRICATING COMPOSITIONS COMPRISING

THE SAME

The invention provides novel compounds and lubricating compositions comprising the same.

For a long time zinc dialkyldithiophosphate (ZnDTP) has been used in a wide range of lubricating oils as an effective additive for imparting wear resistance and extreme pressure characteristics to the lubricating oil.

On the other hand, in recent years the regulations governing the exhaust gases from internal combustion engines have become tighter year by year and the provision of various types of catalysts and filters for cleaning up exhaust gas has become essential. For example, ternary catalysts are fitted to vehicles fitted with petrol engines with a view to cleaning up the hydrocarbons (HC) and nitrogen oxides (NOx). Furthermore, oxidation catalysts and DPFs (diesel particulates filters) are fitted to vehicles with diesel engines with a view to reducing particulate matter (PM) and after-treatment devices such as NOx-absorbing catalysts are fitted with a view to cleaning up the NOx. Moreover, although fuel is burned in an internal combustion engine, burning of not just the fuel but some of the lubricating oil (engine oil) which is being used as well in the combustion chamber cannot be avoided, and so the ZnDTP which has been compounded in an engine oil is also burned and zinc-based ash and sulphur and phosphorous fractions are included in the exhaust gas.

It has been reported that the clean-up performance is gradually reduced as a result of poisoning by the exhaust gas and blockage of the various types of after- treatment device which are fitted with a view to cleaning up the exhaust gas. For example, it is known that the performance of ternary catalysts is markedly reduced as a result of poisoning with sulphur or phosphorus and that the performance of oxidation catalysts and NOx-absorbing catalysts is also greatly reduced as a result of poisoning with sulphur. Moreover, blockage of DPF with ash occurs and this has an adverse effect on the running of the vehicle. Hence, reducing the amount of ZnDTP which is used in engine oil is very important in respect of the effective operation of these after-treatment devices, extending the life expectancy of the devices and protecting the environment, but in those cases where the amount of ZnDTP which is used is reduced, retention without loss of the wear resistance properties of the lubricating oil at the same time is also important.

Against this background, much effort has been directed towards obtaining additives for use in lubricating oils which do not contain zinc or phosphorus or in which at least the content of these elements is low in consideration of the weaknesses such as those indicated above with the known additives, starting with ZnDTP, which do contain zinc and phosphorus. Examples of these lubricating oil additives which are zinc-free (ashless) and phosphorus-free include the reaction products of 2, 5-dimercapto-l, 3, 4-thiadiazole and unsaturated mono-, di- and tri-glycerides (U.S. Patent 5 512 190), dialkyldithiocarbamate derivative organic ethers (U.S. Patent 5 514 189) and 5-alkyl-2- thione-1, 3, 4-thiadiazolidine compounds (Japanese Patent 2004-528475) . The demand for not including metals, such as zinc (Zn) and molybdenum (Mo), and phosphorus (P) has greatly increased not only in the case of the lubricating oils for internal combustion engines as described above, but also in connection with machine oils, hydraulic working oils, gear oils, greases and the like, with a view to reducing the burden imposed upon the environment.

The present invention is intended to provide novel compounds for replacing ZnDTP which do not include a zinc component or a phosphorus component, and lubricating compositions in which these compounds are used.

The present invention provides a compound which can be represented by the general formula (1) which is indicated below.

General Formula (1)

Ri and R₂ in the abovementioned general formula (1) are hydrogen and/or a linear chain or branched chain saturated or unsaturated hydrocarbon moiety with from 1 to 30 carbon atoms or a substituted hydrocarbon moiety which include substitutions where parts have been substituted with hetero-atoms . Furthermore, Ri and R₂ may be the same or different and the total number of carbon atoms of Ri and R₂ is not more than 40, and X is oxygen or sulphur.

Moreover, the hetero-atoms in the substituted hydrocarbon moieties of Ri or R₂ in the above-mentioned general formula (1) are preferably either oxygen, sulphur or nitrogen or a combination thereof, and these hetero-atoms are included in the form of an alcohol, ketone, ester, ether, nitrile, amine, sulphidryl, thioketone, thioester, thioether, polyether or amide for example .

These compounds can be included in lubricating compositions as additives and they are generally added in amounts of at least 0.1 wt.%, and preferably at most 20 wt.%. In accordance with this invention, the novel compounds are useful as replacements for ZnDTP as additives for lubricating compositions, and especially for lubricating compositions for use in engines, and they provide excellent wear resistance and antioxidant performance and are effective for cleaning up the exhaust gas. Furthermore, they can also be used effectively in machine oils, hydraulic working oils, gear oils, greases and the like.

In the compounds which can be represented by the abovementioned general formula (1), General Formula (1)

Ri and R₂ in formula (1) are hydrogen and/or a hydrocarbon moiety which has from 1 to 30 carbon atoms. The hydrocarbon moiety may have a linear chain or a branched chain. Furthermore, it may be a saturated or unsaturated hydrocarbon moiety.

The hydrocarbon moiety may be, for example, a saturated hydrocarbon moiety which can be represented by the general formula (2) . General Formula (2)

"C_nH_2n+I (2)

Methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, undecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, heneicosyl, docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl, heptacosyl, octacosyl, nonacosyl, triacontasyl and the like can be cited as such hydrocarbon moieties of this type. Furthermore, the abovementioned hydrocarbon moiety can be a hydrocarbon moiety which has been obtained by making parts into substituent groups which are substituted with hetero-atoms (referred to in this invention as substituted hydrocarbon moieties). Such hetero-atoms are either oxygen, sulphur or nitrogen, or a combination of these, and these hetero- atoms are generally in the form of an alcohol, ketone, ester, ether, nitrile, amine, sulphidryl, thioketone, thioester, thioether (sulphide), polyether, amide or the like.

The alcohol forms which can be represented by general formula (3), for example, are substituted hydrocarbon moieties which contain oxygen. General Formula (3) -C_nH_2nOH (3)

Hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, hydroxy- heptyl, hydroxyoctyl, hydroxynonyl, hydroxydecyl, hydroxyundecyl, hydroxydodecyl, hydroxytridecyl, hydroxytetradecyl, hydroxypentadecyl, hydroxyhexadecyl, hydroxyheptadecyl, hydroxyoctadecyl, hydroxynonadecyl, hydroxyeicosyl, hydroxyheneicosyl, hydroxydocosyl, hydroxytricosyl, hydroxytetracosyl, hydroxypentacosyl, hydroxyhexacosyl, hydroxyheptacosyl, hydroxyoctacosyl, hydroxynonacosyl, hydroxytriacontasyl and the like, for example, are hydrocarbon moieties of this type.

The ketone forms which can be represented by general formula (4), for example, are substituted hydrocarbon moieties which contain oxygen. General Formula (4)

-C_nH_2n-C (O)-C_mH_2m+1 (4)

(In formula (4) n+m < 29, n >0) -C₂H₄C(O)C₂H₅ (3-oxopentyl) , for example, is a hydrocarbon of this type. Furthermore, -C(O)C₂H₅ (propargyl), for example, can be cited as a case in which n is 0.

Furthermore, the ester forms which can be represented by general formula (5) or general formula (6) are substituted hydrocarbon moieties which contain oxygen . General Formula (5)

~C_nH_2nCOOC_mH_2m+i (5) (In formula (5) n+m < 29)

-C₂H₄COOCH₃ (3-methyoxy-3-oxopropyl) , for example, can be cited as a substituted hydrocarbon moiety of this type.

General Formula (6) -C_nH_2nOC (O)C_mH_2m+1 (6)

(In formula (6) n+m < 29)

-C₂H₄OC(O)CH₃ (2-(l-oxoethoxy)ethyl) , for example, can be cited as a substituted hydrocarbon moiety of this type. The ether forms which can be represented by general formula (7) are substituted hydrocarbon moieties which contain oxygen. General Formula (7) -C_nH_2nOC_mH_2m+i ( 7 )

(In formula (7) n+m < 30, and n > 1) -C₃H₆O-CH₃ (3-methyoxypropyl) , for example, can be cited as a substituted hydrocarbon moiety of this type. The nitrile forms which can be represented by general formula (8), for example, are substituted hydrocarbon moieties which contain nitrogen. General Formula (8)

-C_nH_2nCN (8) For example, cyanomethyl, cyan ethyl, cyanopropyl, cyanobutyl, cyanopentyl, cyanohexyl, cyanoheptyl, cyano- octyl, cyano nonyl, cyanodecyl, cyanododecyl, cyano- undecyl, cyano tridecyl, cyanotetradecyl, cyanopentadecyl, cyanohexadecyl, cyanoheptadecyl, cyano- octadecyl, cyanononadecyl, cyanoeicosyl, cyanoheneicosyl, cyanodocosyl, cyanotricosyl, cyanotetracosyl, cyanopentacosyl, cyanohexacosyl, cyanoheptacosyl, cyano-octacosyl, cyanononacosyl, cyano- triacontasyl and the like can be cited as substituted hydrocarbon moieties of this type.

The primary amine forms which can be represented by general formula (9), for example, are substituted hydrocarbon moieties which contain nitrogen. General Formula (9) -C_nH_2nNH₂ (9)

For example, aminomethyl, aminoethyl, aminopropyl, aminobutyl, aminopentyl, aminohexyl, aminoheptyl, amino- octyl, aminononyl, aminodecyl, aminododecyl, aminoundecyl, aminotridecyl, aminotetradecyl, aminopentadecyl, aminohexadecyl, aminoheptadecyl, amino- octadecyl, aminononadecyl, aminoeicosyl, aminoheneicosyl, aminodocosyl, aminotricosyl, aminotetracosyl, aminopentacosyl, aminohexacosyl, aminoheptacosyl, amino-octacosyl, aminononacosyl, amino- triacontasyl and the like are substituted hydrocarbon moieties of this type.

Furthermore, the secondary amine forms which can be represented by general formula (10) are substituted hydrocarbon moieties which contain nitrogen. General Formula (10)

-C_nH_2nNHC_1nH_2m+1 (10)

(In formula (10) n+m < 30) -C₃H₆NHCH₃ ( 3- (N-methylamino) propyl) , for example, can be cited as a substituted hydrocarbon moiety of this type.

The tertiary amine forms which can be represented by general formula (11) are substituted hydrocarbon moieties which contain nitrogen. General Formula (11)

-C_nH_2nN ( C_mH_2m+1 ) ( C_qH_2q+1 ) (11)

(In formula (11) n+m+q < 30)

-C₃H₆N(CH₃) (C₂H₅) (3-(N,N-methylethylamino)propyl) , for example, can be cited as a substituted hydrocarbon of this type.

The sulphidryl forms which can be represented by general formula (12), for example, are substituted hydrocarbon moieties which contain sulphur. General Formula (12)

-C_nH_2nSH (12)

For example sulphidrylmethyl, sulphidrylethyl, sulphidrylpropyl, sulphidrylbutyl, sulphidrylpentyl, sulphidrylhexyl, sulphidrylheptyl, sulphidryloctyl, sulphidrylnonyl, sulphidryldecyl, sulphidryldodecyl, sulphidrylundecyl, sulphidryltridecyl, sulphidryl- tetradecyl, sulphidrylpentadecyl, sulphidrylhexadecyl, sulphidrylheptadecyl, sulphidryloctadecyl, sulphidryl- nonadecyl, sulphidryleicosyl, sulphidrylheneicosyl, sulphidryldocosyl, sulphidryltricosyl, sulphidryl- tetracosyl, sulphidrylpentacosyl, sulphidrylhexacosyl, sulphidrylheptacosyl, sulphidryloctacosyl, sulphidryl- nonacosyl and sulphidryltriacontasyl .

The thioketone forms which can be represented by general formula (13) are substituted hydrocarbon moieties which contain sulphur. Formula (13) -C_nH_2nC (S) C_mH_2m+1 (13)

(In formula (13)n+m < 29, and n > 0) -C₃H₆C(S)C₂H₅ (4-thiohexyl) , for example, can be cited as a substituted hydrocarbon of this type.

The thioester forms which can be represented by general formulae (14) and (15) are substituted hydrocarbon moieties which contain sulphur. General Formula (14)

~C_nH_2nCSSC_mH_2m+i (14)

(In formula (14) n+m < 30) -C₂H₄CSSCH₃ (3-methysulphidothiopropyl) , for example, can be cited as a substituted hydrocarbon moiety of this type. General Formula (15)

"C_nH_2nSC ( S ) C_mH_2m+i (15) (In formula (15) n+m < 30)

-C₂H₄SC(S)CH₃ (2-(l-thioethylsulphido)ethyl) , for example, can be cited as a substituted hydrocarbon of this type.

Furthermore, the thioether forms which can be represented by general formula (16) are substituted hydrocarbon moieties which contain sulphur. General Formula (16)

~C_nH_2nSC_mH_2m+i ( 16 ) (In formula (16) n+m < 30, and n > 1)

-C₂H₄SCH₃ (2- (methylsulphido) ethyl) , for example, can be cited as a substituted hydrocarbon moiety of this type. The amide forms which can be represented by general formula (17) are substituted hydrocarbon moieties which contain oxygen and nitrogen. General Formula (17)

-C_nH_2nCONH₂ (17) -C₅Hi₀CONH₂ (6-amidohexyl) , for example, can be cited as a substituted hydrocarbon moiety of this type.

The polyether forms which can be represented by the general formulae (18), (19) and (20), according to the number of ether bonds, are substituted hydrocarbon moieties which have a plurality of ether bonds. General Formula (18)

-C_nH_2nOC_mH_2mOC_qH_2q+i (18)

(In formula (18) n+m+q < 30)

-CH₂OC₂H₄OCH₃ (2, 5-dioxahexyl) , for example, is a substituted hydrocarbon moiety of this type which has two ether bonds . General Formula (19)

-C_nH_2nOC_mH_2mOC_qH_2qOC_rH_2r+1 (19)

(In formula (19) n+m+q+r < 30) -CH₂OC₂H₄OC₂H₄OCH₃ (2, 5, 8-trioxanonyl ) , for example, is a substituted hydrocarbon moiety of this type which has three ether bonds . General Formula (20)

-C_nH_2nOC_mH_2mOC_qH_2qOC_rH_2rOC_tH_2t+1 (20) (In formula (20) n+m+q+r+t < 30)

-CH₂OC₂H₄OC₂H₄OC₂H₄OCH₃ (2,5, 8, 11-tetra-oxadodecyl) , for example, is a substituted hydrocarbon moiety of this type which has four ether bonds. The abovementioned Ri and R₂ may be the same or different, and in general it is best if the total number of carbon atoms of Ri and R₂ is not more than 40.

Furthermore, X in the abovementioned formula (1) comprises oxygen or sulphur.

The compound can be used by being added as a constitutional component of a lubricating composition. No particular limitation is imposed upon the amount which is added but generally the compounds are preferably used in an amount such that the content in the lubricating composition is at least 0.1 wt . % .

There are no particular limitations regarding the base oil or grease used in lubricating compositions according to the present invention, and various conventional greases, mineral oils and synthetic oils may be conveniently used.

The base oil used in the present invention may conveniently comprise mixtures of one or more mineral oils and/or one or more synthetic oils. Mineral oils include liquid petroleum oils and solvent-treated or acid-treated mineral lubricating oil of the paraffinic, naphthenic, or mixed paraffinic/naphthenic type which may be further refined by hydrofinishing processes and/or dewaxing. Suitable base oils for use in the lubricating composition of the present invention are Group I, Group II or Group III base oils, polyalphaolefins, Fischer- Tropsch derived base oils and mixtures thereof.

By "Group I" base oil, "Group II" base oil and "Group III" base oil in the present invention are meant lubricating oil base oils according to the definitions of American Petroleum Institute (API) categories I, II and III. Such API categories are defined in API Publication 1509, 15th Edition, Appendix E, April 2002.

Suitable Fischer-Tropsch derived base oils that may be conveniently used as the base oil in the lubricating composition of the present invention are those as for example disclosed in EP 0 776 959, EP 0 668 342, WO 97/21788, WO 00/15736, WO 00/14188, WO 00/14187, WO 00/14183, WO 00/14179, WO 00/08115, WO 99/41332, EP 1 029 029, WO 01/18156 and WO 01/57166.

Synthetic oils include hydrocarbon oils such as olefin oligomers (PAOs), dibasic acid esters, polyol esters, and dewaxed waxy raffinate. Synthetic hydrocarbon base oils sold by the Shell Group under the designation "XHVI" (trade mark) may be conveniently used.

A high level of performance can be achieved if the compounds are used in a lubricating composition for engine purposes in particular, and generally they can be can be used more effectively by using metal detergents, ash-free dispersing agents, antioxidants and the like indicated below conjointly.

Furthermore, the appropriate additives can be used conjointly, according to the application, when the lubricating composition is to be used as a gear oil, machine oil, hydraulic working oil or grease.

The alkaline earth metal salt-type detergents are examples of the abovementioned metal detergents and, for example, Ca salicylate, Ca sulphonate, Ca phenate, Mg salicylate, Mg sulphonate, Mg phenate and the like can be used as detergents of this type. Mono-imide-type or bis-imide-type alkenyl- succinimides or alkylsuccinimides, or boron derivatives thereof, can be used, for example, as ash-free dispersing agents. Furthermore, ash-free dispersing agents of different types may be used, as required, and examples of such dispersing agents include those of the polyalkyleneamide type, the benzylamine type and the succinic acid ester type. These dispersing agents may be boronated. One of these types of ash-free dispersing agent may be used individually, or two or more types may be used conjointly.

Additives which have dispersing properties, for example the polymeric compounds which can impart dispersing properties such as viscosity index raising agents, may be used conjointly or they can be used individually as the abovementioned ash-free dispersing agents .

The amine-based antioxidants and phenol-based antioxidants can be used for the abovementioned antioxidants .

The aromatic amine-based antioxidants can be cited as amine-based antioxidants, and actual examples include dialkyldiphenylamines such as p, p ' -dioctyldiphenylamine, monoalkyldiphenylamines such as mono-t- butyldiphenylamine, bis (dialkylphenyl) amines such as di (2, 4-diethylphenyl ) amine and di (2-ethyl-4-nonyl- phenyl) amine, alkylphenyl-1-naphthylamines such as octylphenyl-1-naphthylamine, arylnaphthylamines such as phenyl-1-naphthylamine, phenylenediamines such as

N, N ' -diisopropyl-p-phenylenediamine and phenothiazines such as 3, 7-dioctylphenothiazine . Furthermore, examples of the phenol-based antioxidants include alkylphenols such as 2-t-butyl- phenol, alkoxyphenols such as 2, 6-di-t-butyl- 4-methoxyphenol, alkyl-3- (3, 5-di-t-butyl-4-hydroxy- phenyl)propionates such benzenepropionic acid 3,5- bis (1, 1-dimethylethyl) -4-hydroxy- (C7-C9 ) side-chain alkyl esters (Irganox L135, produced by the Ciba Specialty Chemicals Co.), bisphenols such as 4, 4 ' -thiobis ( 3- methyl-6-t-butylphenol) (Antage RC, produced by the Kawaguchi Chemical Co.) and 2, 2 ' -thiobis ( 4, 6-di-t- butylresorcinol) , and polyphenols such as 2,6-bis(2'- hydroxy-3 ' -t-butyl-5 ' -methylbenzyl) -4-methylphenol . Examples Example 1 4,5-Bis (dodecathio) -1, 3-dithiole-2-thione (DTTC12), which can be represented by the chemical formula (21) below, is one compound which can be represented by the above-mentioned Chemical Formula (1) . Chemical Formula (21)

(21)

S S-D-C₁₂H₂₅

The compound with the chemical formula (21) can be produced in the following way.

[NBuⁿ ₄! _j £Zn (C₃S₅) ₂] + 4C₁₂H₂₅ I

CH₃CN

Room temperature, 8 hours

A pear-shaped flask and a stirrer were provided for the synthesis and the reaction apparatus was used in a fume cupboard.

Bis (tetra-n-butylammonium) bis (1, 3-dithiol-2-thione- 4,5-dithioate) zinc complex (20.045 g, 21.256 mmol),

25.180 g (85.004 mmol) of 1-iododecane and acetonitrile were added to the pear-shaped flask, a stirrer tip was introduced and reaction was carried out at room temperature with stirring for 8 hours under a nitrogen atmosphere.

After completing the reaction, the solvent (acetonitrile) was distilled off in an evaporator and then the impurities were separated by means of column chromatography (developing solvent: a 2:3 solvent mixture of dichloromethane : n-hexane) and, after distilling off the developing solvent, 16.830 g of the compound of chemical formula (21) were obtained as yellow plate-like crystals (yield 74%) on drying under reduced pressure. This compound was subjected to mass spectroscopy

(EI⁺ 70 eV) and identified by confirming relative intensity m/z = 534 [M+, 100%] and m/z 536 [(M+2)⁺, about 26%) . Example 2

4, 5-Bis (octadecathio) -1, 3-dithiole-2-thione (DTTC18), which can be represented by the chemical formula (22) below is also a compound which can be represented by the above-mentioned Chemical Formula (I] Chemical Formula (22)

The compound with the chemical formula (22) can be produced in the following way.

[NBu\] _j [Zn CC₃S₃) ₂3 + 4C₁₈H₃₇I

CH₃CN

Room temperature, 8 hours

A pear-shaped flask and a stirrer were provided for the synthesis and the reaction apparatus was used in a fume cupboard. Bis (tetra-n-butylammonium) bis (1, 3-dithiol-2-thione- 4, 5-dithioate) zinc complex (12.003 g, 12.728 mmol), 19.375 g (50.935 mmol) of 1-iodooctadecane and acetonitrile were added to the pear-shaped flask, a stirrer tip was introduced and reaction was carried out at room temperature with stirring for 8 hours under a nitrogen atmosphere.

After completing the reaction, the solvent (acetonitrile) was distilled off in an evaporator and then the impurities were separated by means of column chromatography (developing solvent: a 2:3 solvent mixture of dichloromethane : n-hexane) and, after distilling of the developing solvent, 11.1 g of the compound of chemical formula (22) were obtained as yellow plate-like crystals (yield 62%) on drying under reduced pressure.

This compound was subjected to mass spectroscopy (EI⁺ 70 eV) and identified by confirming relative intensity m/z = 702 [M+, 100%] and m/z 702 [(M+2)⁺, about 30%) .

Example 3

4, 5-Bis (dodecathio) -1, 3-dithiole-2-one (DTTOC12) , which can be represented by the chemical formula (23) below is also a compound which can be represented by the above-mentioned Chemical Formula (1) . Chemical Formula (23)

(23)

The compound with the chemical formula (23) can be produced in the following way.

minutes

A pear-shaped flask and a stirrer were provided and the reaction apparatus was used in a fume cupboard. The 4, 5-bis (dodecathio) -1, 3-dithiole-2-thione

(DTTC12) synthesized in Example 1 (11.0 g, 20.56 mmol), 1.638 g (5.1400 mmol) of mercury(II) acetate, 50 ml of chloroform and 65 ml of acetic acid were added to the pear-shaped flask, a stirrer tip was introduced and reaction was carried out at room temperature with stirring for 30 minutes under a nitrogen atmosphere. After completing the reaction, the solution was suction-filtered using Celite and the filtrate was washed successively with water, sodium bicarbonate and water. The washed organic layer was de-watered and dried with magnesium sulphate, the magnesium sulphate was filtered off and the solvent was distilled off in an evaporator and then 9.180 g of the compound of chemical formula (23) were obtained as peach-coloured crystals (yield 86%) on drying under reduced pressure.

This compound was subjected to mass spectroscopy (EI⁺ 70 eV) and identified by confirming relative intensity m/z = 518 [M+, 100%] and m/z 520 [(M+2)⁺, about 30%) . Examples 4 and 5: Lubricating Compositions

The following compounding materials were used to prepare the lubricating compositions of Examples 4 and 5 and Comparative Examples 1 and 2, using the compounds disclosed in Examples 1 and 3 above.

1. Base Oil:

GUI Base oil; a base oil of the API (American Petroleum Institute) base oil category GUI (group 3). (Characteristics: viscosity at 100⁰C 8.152 mmVsec, viscosity at 40⁰C 47.92 mm²/s, viscosity index 144.)

2. Additives:

2-1 Ca-based Metal Detergent: Infineum M7101 (produced by the Infineum Co.), a Ca salicylate with typical values for the base value 168 mgKOH/g and sulphuric acid ash 20%.

2-2 Ash-free Dispersing Agent: OLOA5093 (produced by the

Olonit Co.), typical values for the base value 24 mgKOH/g, bis type, nitrogen content 1.2%.

2-3 Phenol-based Antioxidant: Irganox L135 (produced by the Ciba Specialty Chemicals Co.) Benzenepropionic acid

3, 5-bis (1, 1-dimethylethyl) -4-hydroxy- (C7-C9) -side-chain

-alkyl ester. 2-4 ZnDTP (secondary type) : Lubrizol Lz 1371 (produced by the Lubrizol Co.)

The formulated compositions of the lubricating compositions for engine use of Examples 4 and 5 and

Comparative Examples 1 and 2 were as shown in Table 1. Furthermore, the property values indicated below for each of Examples 4 and 5 and Comparative Examples 1 and

2 are similarly shown in Table 1.

3-1 Nitrogen content (calculated value) 3-2 Phosphorus content (calculated value] 3-3 Sulphuric acid ash (calculated value] 3-4 Viscosity (40⁰C) 3-5 Viscosity (100⁰C) 3-6 Viscosity index (VI) Te st 1

A Shell four-ball test was carried out under the conditions indicated below in accordance with ASTM D4172 in order to evaluate the performance of the lubricating compositions for engine use. (4-1) Load: 392 N (40 kgf) (4-2) Temperature: 75°C (4-3) Number of Revolutions: 1800 rpm (4-4) Testing Time: 30 minutes Test 2

A hot-tube test (HTT) was carried out under the conditions indicated below on the basis of JPI 5S-55-99 (Japanese Petroleum Institute Method) (5-1) Temperature: 280⁰C (5-2) Testing time: 16 hours

(5-3) Air feed rate: 10 ml/min (5-4) Oil feed rate: 0.3 ml/hr Results

The results of Tests 1 and 2 indicated above are shown in Table 1. Evaluation

Example 4 provided improved wear resistance as assessed by the Shell four-ball test when compared with Comparative Example 1, and in the HTT there was a rise from the score of 5.0 for Comparative Example 1 to 8.0

(in the JASO M355: 2005 specifications the pass level is 7.0 or above), and the cleanliness was improved and it was assessed that the production of oxidation degradation products had been suppressed. Furthermore, Example 5 provided improved wear resistance as assessed by the Shell four-ball test when compared with Comparative Example 1, and good results similar to those of Example 4 were seen in the HTT with a score of 8.5, and it was assessed that the cleanliness was excellent.

Furthermore, with the use of commercial ZnDTP (zinc dithiophosphate) shown as Comparative Example 2 the sulphuric acid ash was increased since there was a zinc metal fraction and, furthermore, a (P) fraction was also admixed.

Since Examples 4 and 5 gave better HTT results when compared with Comparative Example 2 it can be said that the cleanliness was improved by suppressing the formation of oxidative degradation products. Furthermore, as indicated by the Shell four-ball tests, in terms of the wear resistance Example 4 had similar performance to that of Comparative Example 2, and although Example 5 was worse than Comparative Example 2 it was better than Comparative Example 1, and it is possible to provide a reduction in the phosphorus fraction in the composition by using substitutes for the ZnDTP. Hence, both of the examples could be used instead of

Comparative Example 2 in which ZnDTP was used and the cleanliness is good, and there is also an environmental aspect in that no metal fraction or phosphorus fraction is included.

Table 1

Claims

C L A I M S

1. A compound having the general formula (1) below

wherein Ri and R₂ are independently hydrogen and/or a linear or branched chain, saturated or unsaturated hydrocarbon moiety with from 1 to 30 carbon atoms or a substituted hydrocarbon moiety, including substitutions where one or more of these hydrocarbon moieties have been substituted with hetero-atoms; wherein the total number of carbon atoms of Ri and R₂ is not more than 40; and wherein X is oxygen or sulphur.

2. A compound according to Claim 1, wherein the hetero- atoms in the substituted hydrocarbon moieties of Ri or R₂ in the abovementioned general formula (1) are either oxygen, sulphur or nitrogen or a combination thereof.

3. A compound according to Claim 2, wherein the hetero- atoms in the substituted hydrocarbon moieties of Ri or R₂ of the abovementioned general formula (1) take the form of an alcohol, ketone, ester, ether, nitrile, amine, sulphidryl, thioketone, thioester, thioether, polyether or amide .

4. A lubricating composition comprising a base oil and a compound according to any of Claims 1 to 3.

5. A lubricating composition, according to Claim 4, wherein the content of the compound according to Claim 1 is at least 0.1 wt%.

6. A lubricating composition, according to Claim 4, wherein the base oil is an individual mineral oil or synthetic oil including the poly-α-olefin, ester, ether and Fischer-Tropsch synthetic oils, or a mixture of such oils .

7. Use of the lubricating composition according to any of Claims 4 to 6 as an internal combustion engine oil, gear oil, machine oil, hydraulic oil or grease.

8. Use of the lubricating composition according to any of Claims 4 to 7 for improving one or more of wear resistance properties and extreme pressure characteristics .

9. Method of improving one or more of wear resistance properties and extreme pressure characteristics by lubricating using the lubricating composition according to any of Claims 4 to 7.