CA1094053A

CA1094053A - Lubricant additive formed by neutralisation of a sulphurised alkyl phenol and a mannich base

Info

Publication number: CA1094053A
Application number: CA275,057A
Authority: CA
Inventors: John Crawford; Geoffrey A. Hill
Original assignee: Chevron Research and Technology Co
Current assignee: Chevron USA Inc
Priority date: 1976-04-08
Filing date: 1977-03-29
Publication date: 1981-01-20
Also published as: NL7703855A; DE2715774A1; JPS52123406A; FR2347437A2

Abstract

ABSTRACT OF THE DISCLOSURE

A lubricant additive is produced by neutralising with an alkaline earth metal oxide or hydroxide a sulphurised alkyl phenol containing at least 4 weight per cent sulphur in admixture with a Mannich base formed from an alkylene or polyalkylene polyamine, an alkyl phenol and formaldehyde at elevated temperature in the presence of a hydroxylic solvent, the Mannich base being pre-prepared or prepared "in situ". Neutralisation can be effected in the presence of a ca? oxylic acid, such as acetic acid. In an additional step the neutralised product is reacted with carbon dioxide in the presence of the hydroxylic solvent.

Description

lO9~0S3 ~he present invention relate~ to basic lubricsnt additive~.
Lubricating oile U8~d under the severe conditions of die~el engines are highly compounded ~o as to provide neutralisation of acids derived from the sulphur in the fuel and from o~idation of hydrocarbons, both of the fuel and oil, di~p~r~ancy 80 B~ to maintain sludge-forming precursors disperssa in the oil, improved wear protection and oiliness properties, as well ae to enhance other attributes of the oil. In addition to the requirements normally needed in a diesel lubricsting oil, tho~e oils which find use in railway diesel engines have the additional requirement of not being corro~ive or reactive to silver. Silrer besrings are u~ed in a prepondersnt number of diesel engines today.
~he desirability of having a single additive providing multifunctional properties is evident in the efficiency and economy in the manufacture and use of a single additive as compared to a plurality of additives. However, because of the severe operating conditions under which a lubricating oil performs in diesel engine~, it i9 frequently found that additive~, while effectively performing a particular function, will tend to degrade and enhance deposit form~tion. ~herefore, in designing any particular additiYe, it i9 essential not only that it fulfil~ the function(s) for which it ha3 been designed, but that it be 3table under the cQnditions of use or degr~de3310~1y to msterials which do not enhance depo3it formstion.
AIkaline earth metal pheno~ides or phen~tes ha~e been used in lubricating oils for a long per~od of ~ime. Both sulphurised aIkylphenols and Msnnich ba3e3 have been employed in lubricsting oils. U.S. Patent Nos., 2,459,114 and 2,459,116 teach the prepara-tion of Mannich product3 employing polyamines with sulphur-bridged alXyl phenols. ~.S. Patent No. ~,454,497 prepares a Mannich ba3e using methyl amine, formaldehyde and alkylphenols for use in lubricating oils.
Other patents of interest include United States Patent Nos. 2,810,697, 3,372,118, 3,429,812, 3,472,773, 2,527,279, 2,763,616, 3,368,972, 2,410,911,

2,962,442, 3,413,347 and 3,340,190.
British patent specification No. 1,352,760 describes and claims a dispersant detergent suitable for use as a lubricating oil additive, comprising the reaction product obtainable by the neutralisation with an alkaline earth metal oxide or hydroxide of a sulphurised alkylphenol containing at least 4 weight per cent sulphur and a Nannich base containing at least 2 weight per cent nitrogen and having a molecular weight of at least 600 and prepared from a Cl to C3 alkylamine, an alkylphenol and formaldehyde, the neutralisation being carried out in the presence of a hydroxylic Solvent and at an elevated : temperature so that molecular bonds are formed between the Mannich base and the sulphurised alkylphenol in addition to the bridging bonds created by the alkaline earth metal.
Our British Patent No. 1,568,959 describes a detergent dispersant phenate having a lower ash content for the same degree of alkalinity reserve : prepared by replacing the Cl to C3 alkyl amine used in the preparation of the Mannich base from which the product described in British patent specification No. 1,352,760 is obtained by an alkylene or polyalkylene polyamine having the structural formula:
H2N ( alkylene - NH t H
wherein n is an integer in the range from 1 to 10 and the alkylene group has from two to eight carbon atoms.
Our British Patent No. 1,570,489 describes a compound suitable for use as a lubricating oil additive comprising the 16~9~053 reaction product obtainable by the neutralisation with an alkaline earth metal oxide or hydroxide of a sulphurised alkylphenol and a Mannich base, the neu-tralisation being carried out at an elevated temperature, so that lecular bonds are formed between the Mannich base and the sulphurised alkylphenol in addition to the bridging bonds created by the alkaline earth metal, the reac-tion being effected in the substantial absence of a hydroxylic solvent.
It has now been found that compounds suitable for use as low-ash basic lubricant additives result when the reaction product obtainable by the neutralisation with an alkaline earth metal oxide or hydroxide of a sulphurised alkylphenol in admixture with a Mannich base is reacted with carbon dioxide.
Thus according to the present invention there is provided a compound suitable for use as a lubricating oil additive comprising the reaction product obtained by neutralising with an alkaline earth metal oxide or hydroxide a sulphurised alkylphenol containing from 4 to 20 weight percent sulphur in admixture with a Mannich base containing from 2 to 10 weight percent nitrogen and having a molecular weight of from 600 to 5,000 and prepared from an alkylphenol, formaldehyde and an alkylene or polyalkylene polyamine having the structural formula:-H2N t alkylene - NH -~ H (I) wherein n is an integer from 1 to 10 and the alkylene group has from two to eight carbon atoms, the neutralisation being carried out in the presence of a hydroxylic solvent and at an elevated temperature, and thereafter reacting the neutralised product with carbon dioxide.
It is believed that in the process of neutralising the sulphurised alkylphenol with the Mannich base molecular bonds are formed between the Mannich base and the sulphurised alkylphenol in addition to ~he bridging bonds created by the alkaline earth metal.

lO9~0S3 ~e 8~ bL;La~ aIkYlDh~ol Sulphuri~ed alkylphenols are well known material~ for use in lubricating oils. The method of preparation of the sulphurised slkylphenols is not critical to this invention.
The sulphurised alkylphenols may comprise for the most part, and preferably comprise at least 90 percent of sulphurised alkyl-phenols having the following formula:-/ OH \ OH

~ ~ R2 (II) wherein R2 is an alkyl group containing from 8 to 36 carbon atoms, more usually from 10 to 30 carbon atoms with the average number of carbon atoms being in the range of about 10 to 26, yl is an integer in the range from 1 to 9, more usually from 1 to 5, averaging over the entire composition in the range from about 2 to 4, and n~ i~
an integer of from 1 to 5, more usually from 1 to 3. There may ; be small amounts not more than about 10 weight percent of sulphuri~ed phenol having y1 greater than 9.
The ~ulphurised alkylphenol contains at least about 4 weight percent sulphur and preferably not more than 20 weight percent sulphur, more usually from about 8 to 18 weight percent sulphur.
The aliphatic hydrocarbon groups designated ~2 in the structural formula (II) may suitably be in the ortho, or Dara-po~itions, but preferably they will be predominant~y in the ~ara-positions since ortho-~ubstituted phenols act as chain terminators in the copolymerisation of sulphur and slkylphenol. The pre~ence of branched chain alkyl ~roup~ result~ in reduced amoJ~.ts of ortho-substi~lted phenols, and branched-chain alkyl groups are ~ therefore preferred.

lU940S3 Th~ sulphurised alkylphenol may be prepared by combining alkylphenol, sulphur, calcium oside, or calcium hydro~ide and glycol at an elevated temperature, driving off the water and hydrogen ~ulphide, followed by isolation of the sulphurised alkylphenol, as disclosed for e~ample in U.S. Patent No. 2,989,466.
Sulphur monochloride may also be used to prepare sulphurised alkylphenol~, for instance, by employing a Friedel-Crsfts catalyst to aid the reaction. Variou~ methods of preparin~ sulphurised alkylphenols may be found in U.S. Patent Nos. 2,362,289, 2,451,~54, 2,744,083, and 3,367,867.
The Nannich base The Mannic~. bases which are employed may be prepared for instance by combinin~ at elevated temperatures, an alkylphenol, formaldehyde and the alkylene or polyalkylene polyamine h~ving the structural formula (I). The alkylphenol may suitably contain from 4 to 40 carbon atoms, preferably from 9 to 25, even more preferably from 10 to 14 carbon atoms in the ~lkyl group. The formaldehyde may be added in the form of an aqueous solution (formalin) or in a polymeric form e.g. paraformaldehyde. A method for preparing the Mannich bases may be found in U.X. application No. 25316/71 (Serial No. 1,345,030). U.S. Patent No. 3,454,497 describes an additional method for preparing Mannich bases employing primary amines.
The preferred alkylene polyamines having the fermula (I) are the ethylene polyamines wherein the alkylene group ha~ two carbon atoms~ A preferred ethylene polyamine is diethylene triamine.
Other polyalkylene polyamines of formula (I) which may be used include ethylene diamine, tetraethylene pent~mine snd triethylene tetramine. Further alkylene polyamines which may be used include, for e~ample, propylene polysmines and buty~ene polyamine~. The ;

alkylene polyamines m~v be prepared by methods well-kno~n in the art.
The Mannich bage (undiluted) contsins st least 2 weight percent nitrogen and preferably not more than about 10 ~eight percent nitrogen. The average molecular weight, as determined ; by o~mometry, i8 at least 600, more u~ually at lea~t 700, and normally not exceeding about 5,000.
The Mannich base may be in the mono- or bis-form, the ~articular form being governed by the ratio of alkylphenol to formaldehyde to amine material in the initial preparative mi~ture.
The alkaline earth metal oxide or hvdroYide The alkaline earth metal oxide or hydroside is preferably an oxide or hydroxide of calcium or barium, calcium hydroxide being mo~t preferred.
The hvdro~vlic solvent Suitable hydro~ylic solvents include ethylene glycol, pro w lene glycol, butane diols and methanol. 1,3-, 1,4-, or 1,2-butane diol may be employed. The preferred hydro~ylic solvent is ethylene glycol.
The products of the present invention are comples in nature.
Because of the variety of the possible reactions which might occur during the formation of the product any attempt to define the composition by mean~ of a general structural formula Nould be meaningless.
Neutralisation of sul~hurised alkYl~henol and Mannich base The Mannich ~a~e and the sulphuri~ed alkylphenol are advantageously mi~ed in an equivalent ratio (based on phenol) in the range of 0.2-5:1, more usually 0.3-3:1~ In addition to the above reactants are included an alkaline earth metal oxide ~0 or hydroside, preferably hydro~ide, and a hydro~ylic solvent, ~0940S3 usually ethylene glycol.
The smount of alkaline earth metal base added will depend on the method of preparation of the Qulphuri~ed alkylphenol. To the estent that an alkaline earth metal base was employed during the preparation of the sulphurised alkylphenol, the added amount of alkaline earth metal base may provide a total of up to one equivalent of alkaline earth metal present per equivalent of alkylphonol present in the final product. Alternatively an e~cess Gf the aLkaline earth metal base may be employed usually not exceeding 1.75 equivalents, and more usually not exceeding 1.5 equivalents of alkaline earth metal per equivalent of alkylphenol present in the final product.
The amount of the hydroxylic solvent will vary with the particular ~olvent employed and the optimum amount can readily be determined by trial. Since ethylene glycol i~ the preferred solvent, only its use will be discu~sed in detail. The amount of ethylene glycol employed may normally be from about 5 to 35 weight percent, preferably from about 7 to 20 weight percent, of the total reaction mi~ture.
In addition to the ethylene glycol, an inert hydrocarbon diluent may also be present. These inert diluents may be of ~ervice to aid in the handling of the reactants, lowering the vi3cosity of the reaction mi~ture, and enchancing the ease of isolation of the product.
In view of the intended use of the composition~ of the invention, mineral oils of lubricating viscosity may be used and the product isolated as a ~olution in the mineral oil. Normally the inert diluent may be present in t~e reaction mi~ture, if at all, in ~mounts of from 3 to 65 weight percent, more usually 5 to 50 weight percent of the total reaction mi~ture.
Conveniently, a small amount of an anti-foaming agent or foaming suppressant may be employed. The foam suppressant is suitably present in the reaction mi~ture in amounts of 1 Y 10 3 to 1 ~ 10-5 weight percent. Conventional foam suppressants may be employed.
Additionally a small amount of a neutral aIkaline earth metal sulphonate may suitably be included in the reaction mi~ture to facilitate the dispersal of the alkaline earth metal oside or hydroYide throughout the mi~ture and improve the neutralisation reaction rate. The neutral alkaline earth metal sulphonate may be a synthetic or naturally occurring material and is preferably calcium sulphonate. ~he amount of alkaline earth metal 3ulphonate added may suitably be in the range from 1 to 5~' by weight.
The reaction may be conveniently carried out by mi~ing the sulphurised alkylphenol, the Mannich base, the alkaline earth metal oxide or hydro~ide, the hydro~ylic solvent e.g. ethylene glycol, and optionally the inert diluent. Preferably, prior to the addition of the ethylene glycol, the mixture is heated to at least 90C, but below the temperature at which the neutralisation i~ to be carried out. After addition of the ~hylene glycol, the temperature may be raised 80 as to distil water overhead, removing the water of reaction. Uæually the temperature during removal of water will range from 125 to 160C.The time required for the removal of water will usually be from about 30 minutes to 3 hours.
Neutralisation_of sul~hurised alkvlPhenol and Precursors of Mannich base Alternatively the reaction may advantageously be carried out by first reacting the sulphurised alkylphenol with the precursors of the Mannich base to form a product containing sulphurised alkylphenol and M&nnich base and thereafter neutralising the product with the alkaline earth metal oxide or hydro~ide in the presence of the ~ hydro~ylic solvent e.g. ethylene glycol.

The sulphurised alkylphenol may suitably be reacted with the alkylphenol in an equivalent ratio (based on phenol) in the range offrom 0.2 to 10:1, preferably 0.2 to 5:1, even more preferably about 1:1. The alkylene or polyalkylene polyamine may suitably be present in an amount of from 1 to 3 moles for every 1 to 3 moles of alkyl phenol present in the reaction mixture. The formaldehyde may suitably be present in an amount of from 0.7S to 1.25 moles for every 1 to 3 moles of alkylphenol present in the reaction mixture.
The reaction between the sulphurised alkylphenol, the alkylphenol, the alkylene or polyalkylene polyamine and the formal-dehyde may be effected by mixing the reactants together and heating them to a temperature sufficient to cause the reaction to occur. The reaction is preferably carried out in the presence of a solvent. Pre-ferred s-olvents are the water-immiscible solvents including water ~nsoluble alcohols (e.g. amyl alcohol) and hydrocarbons. Hydrocarbon solYents boiling in the range 50 to 20QC, e.g. benzene, toluene and xylene are the preferred water-immiscible solvents. Of these the most preferred solvent is toluene. Suitably the solvent may be em-ployed in an amount of from 1 to about 5Q, prefera~ly from 3 to about 25, even more preferably from 5 to 10% by weight based on the total weight of the reaction mixture.
Reaction may suitably be effected at a temperature in the range 50 to 150, preferably 50 to 130C. When a solvent is em-ployed it îs preferred to conduct the reaction at the reflux temperature of the ~eaction mixture. For example when toluene is used as the solvent the condensation suitably proceeas at about 110 to 130C. At the end of the reaction the temperature may be raised to about 150C in order to remove the toluene solvent. The water formed in the reaction co-distils together with the water-immiscible solYent, permitting its removal from the reaction zone.

During this solvent removal step the pressure X~

1~40S3 may be reduced. The time required to complete the reaction depends upon the reactants employed and the reaction temperature used.
Reaction times of from 1 to 8 hourg are usually sufficient.
Neutralisation of the complex product so-obtained may be effected in the same manner as hereinbefore described for the reaction between the sulphurised alkylphenol and the pre-formed Mannich base.
Neutralisation in the ~regence of a carbo~vlic acid According to another aspect of the present invention neutrali-sation of the sulphurised alkylphenol in admi~ture with the Mannich base or the precursors thereof i9 effected in the presence of a carboxylic acid.
`llhilst any carboxylic acid may be present during neutralisation, the presence of a C1 to C~0 carbo~ylic acid is preferred. A particularly preferred carboxylic acid is acetic acid. The carboxylic acid may be present in an amount of from 0.001 to 0.5 moles, preferably from 0.02 to 0.1 moles per mole of alkylphenol present in the reaction mixture.
Rea~tion with carbon dioxide Whilst the neutralised product may be reacted with carbon dioxide at a later stage in the proceedings after the hydroxylic solvent has been removed it is preferred to react the neutralised product with carbon dioxide in the presence of the hydroxylic solvent i.e. before removal of the solvent. The carbon dio~ide may conveniently be introduced into the neutralised product mixt~re by blowing under pre~sure. Reaction with carbon dioxide is preferably effected at the temperature employed during the neutralisation reaction i.e. 140 to 150C, although higher tempera-tures may be employed if de~ired. The amount of carbon dio~ide added may suitably be in the range 1 to 15, preferably 1 to 8 percent ~0 by weight~ based on the total weight of the reaction mixture.

-- 11_ iO94053 Remov~l of hvdroxYlic solvent Whilst incorporation of a hydro~ylic solvent facilitates the production of the compound its presence i8 not desirable in the lubricating compositions in which the compound is most advantag-eously employed. It is therefore preferred to remove the hydro~ylic solvent after formation of the compound. In the case of ethylene glycol as solvent this may be achieved by raising the temperature to below 200C and reducing the pressure sufficiently to allow its distillation. Usually the temperature during removal of ethylene glycol may be in the range from 140 to 200C, preferably from 1~0 to 190C. The pressure may be varied depending upon the temperature and rate of distillation required. The reduced pressure may vary from about 0.01 to 0.8 atmospheres. Ethylene glycol may be removed over a period of from 15 minutes to 9 hours. The time, whilst not a critical factor, should not be unduly prctracted, and will depend o-. the capac~ty of the equipment, the amount of reactants, the degree of foaming and the ability to control the temperature and the rate of th~ removal of distillates.
When no further ethylene glycol coms-q over, the reaction mi~ture may be cooled. At this stage it is preferred to add an inert diluent. Depending on the presence and amount of inert diluent already in the reaction mi~ture, the temperature i~
preferably maintained above about 150C prior to sufficient dilution with a convenient diluent. The miYture can become eYtremely viscous, and qolution into a diluent is difficult below a temperature of about 150C. Any convenient diluent may be u~ed, but in view of the intended ultimate use normally a hydrocarbonaceous lubricating oil will be used a~ the diluent. Depending on the end use variouR hydrocarbonaceous lubricating oils may be employed.
Whether further diluent is added or not, it i~ preferred to filter off any unde~irable insoluble compounds.

The ~roduct of the invention The product as formed (independent of any diluent) willnormally have alknlinity value (ASTM Test - ~2896) in mg. ~0 ~ g. in t~e range 100 to 450, more usually about 175 to 400. The product will normally provide in elemental analysis from about 2 to 12, more usually from about 3 to 7, weight perc~nt alkaline earth metal, at least about 0.1 to 5, more usually from about 0.5 to 4, weight percent nitrogen, and from about 0.8 to 10, more usually from about 1 to 8, weight percent sulphur. In a 100 neutral oil, (100 being the viscosity at 100F in SUS) at an alkaline earth metal concentration of 0.88 molar (3.5 weight percent for Ca), the viscosity at 210F, will normally be in the range of about 200 to 3000 SUS, more usually in the range of 200 to 1,500 S~S.
Formulation of the ~roduct~ of the invention As diluted the product i8 ready to be employed as a con^entrate for formulating fini3hed lubricating oils or may have added thereto other conventional additive compounds.
The invention therefore additionally provides a concentrate composition suitable for formulating finished lubricating oil9 comprising a minor proportion of a hydrocarbonaceous lubricating oil and a major proportion of an additive package consisting of, or containing, the hydrosylic solvent-free compound obtained as hsreinbefore described.
The additive package may consist entirely of the hydro~ylic solvent-free compound as hereinbefore described in an amount up to 95% ~/w based on the total weight of the concentrate composition.
Alternatively the additive package may contain at least 5a~0 W/W of the hydro~ylic ~olvent-free compound as hereinbefore described and up to 90~o W/N of other additives, based on the total weight of the concsntrate composition. The other additives may be, for e~ample~ VI improvers, pour-point depres~ants, anti-foam agents, o~idation inhibitors, e~treme pressure agents or any of the additives commonly used in lubricating oil formulations.
According to another aspect of the present invention there is provided a finished lubricant composition comprising a major proportion of a lubricant base oil and a minor proportion of the concentrate composition as hereinbefore described.
The lubricant base oil may be a mineral oil derived from petroleum or a synthetic oil based, for example, on esters.
Conventional lubricant additives may be incorporated into the finished lubricant compo~ition to ~upplement any already pregent in the concentrate composition.
Although the compounds of the present invention have similar alkalinity reserves to conventional additives their ash content i9 very much lower.
The invention will now be illustrated with reference to the following ~amples~
E~am~le A
Preparation of sul~hurised alkvlDhenol A mixture of 4448g of a C12 alkylphenol, prepsred by alkylating phenol with propylene tetramer, 206.6g of CaO and 1280g of sulphur were heated to 125C and then 165g of ethylene glycol were added.
The reaction temperature was raised to 150C and the pressure reduced to 210 mm Hg and held at that value for 1 hour.
The temperature was then further raised to 195C and the pressure reduced to 40 mm Hg for a period of 2 hours during which time all the ethylene glycol was removed.
The product was analysed and the following values derived for Ca content, Alkalinity Value (A.V.)* and S content:-Ca = 2~41~o w/w (theoretical - 2.5~) h.~. = 74.6 mg ~0 ~ g (theoretical - 70) S = 13.6~o' w/w ~ 14 -" 10940S3 * Throughout the specification A.V. represents the aIkalinity value as measured by the procedure described in ASTM D2896.
Esample_B
Pre~aration of Mannich base A mi~ture of 4448g of a C12-aLkylphenol, prepared by alkylsting phenol with propylene tetramer, 826g of diethylene triamine, 480g of paraformaldehyde and 2 litres of toluene ~ere hested to reflux and the wster removed via a Dean and Stark head.
1 litre of water was added to the misture and then removed together with the toluene solvent. A maximum temperature of 160C was then maintained for 1 hour at a pressure of 40 mm ~g.
~he product was analy~ed and the following value~ obtained for CB content, A.V. and S content:-A,V. = 244 mg K0 ~ g % N = 5.97 ~iscosity210 = 4.6 E~am~le 1 1066g of a Mannich base ~prepared from 1 mole of C12_alkylphenol, 0.5 mole of diethylene tetramine and 1 mole paraformaldehyde using the procedure of E~ample B), 728g of a sulphurised alkylphenol (prepared a8 described in Example ~ and having a S content - 14.7~o) and 628g of diluent oil were charged to a 5 litre flask and heated to 100C. 185g calcium hydroYide and 600g of ethylene glycol were then added. The temperature was then increased to 125C and the pressure reduced to 510 mm Hg for a period of 15 mins. The tsmperature was then increased to 150C at the same pre~ure and the reaction mi~ture held under those conditions for a period of 1 hour whilst the water formed in the reaction was removed.
95~ f C2 repre~enting 3~o by weight of the total reaction lO9AOS3 mi2ture was then blo~n into the reaction mi~ture.
Following injection of the C2 the pressure was reduced to 50 mm Hg pressure and the temperature increased to 185C for a period of 15 mins whilst ethylene glycol was removed from the product. On cooling a further 268g of diluent oil was added and the material filtered.
The product WaQ analysed and the results of the analysis are gi~en in t~e following Table 1.
Exam~le 2 The same procedure as that described in E~ample 1 was followed except that 159g C02 representing 5% by weight of the total reaction mi~ture was in~ected into the reaction misture.
Exam~le ~
The procedure of Esample 1 was followed e~cept that 87g C02 representing 3~ by weight of the total reaction mixture was blown into the product after removal of the ethylene glycol and cooling to 150C.
Comparison Teqt 1 The procedure of E~ample 1 was followed except that no carbon dio~ide was added at any stage of the reaction and subsequent work-up.

AnalYsis of Products Example No.
Determination 1 2 3 Comparison _, .

Ca (~ b.w.) 4.05 4.19 4.11 4.54 N (~ b.w. 2.18 2.09 2.16 2.13 S (% b.w. 2.55 2.49 2.87 3.21 A.Y. (mgKOH/g) 198 198 206 190 V21Q** (C9) 367 231 512 629 S04 Ash (~o b.w.) 14.04 12.75 13.85 11.1 C2 (~ b.w.) 0.97 1.88 0.63 ** V210 is the viscosity measured at 210F.

10~?4053 E~amination of the above Table sho~s that the produets of E~ample 1 and 2 wherein the neutralised product is reacted with earbon dio~ide in the presenee of ethylene glycol have considerably lower viscoQities than the product from the Comparison Testlin which no carbon dio~ide was added. Furthermore the product of E2ample 3 wherein the carbon dio~ide was reacted with the neutralised product after removal of ethylene glycol has a lo~er viscosity than the product of the Comparison Testlthough not 90 low a~ the products of Examples 1 and 2. The lower vi~cosities lG of the products of EYamples 1 and 2 are achieved at marginally higher a3h contents and marginally lower sulphur contents than the product of the Comparison Testlthough the values for these parameters are comparable with those for the product of Example

3. All other values for the contents of Ca and N and the acid value are comparable.

10~4053 Example 4 A mixture of 371g of sulphurised alkyl phenol (= 1 mole), 278g of C12 alkyl phenol (= 1 mole), 500 mls of toluene, 90g diethylene triamine and 50g paraformaldehyde was heated to remove the water of reaction. The mixture was then vacuum stripped to remoYe all the toluene solvent, the maximum temperature being 150C
and the pressure 40 mm Hg.
To the reaction product was added 275g diluent oil, llOg Ca(OH)2 and 300 ml ethylene glycol. This mixture was heated to 125C for 15 minutes and then the temperature was raised to 150C
for 1 hour.
The neutralised product was carbonated by blowing in 40g C2 and was then Yacuum stripped to remove the ethylene glycol at a $emperature up to 190C and a pressure of 30 mm Hg.
To the carbonated neutralised product was added 50g diluent oil, after which the product was cooled and filtered.
Product analysis : A.Y. = 258 mg KOH/g ~is210 _ 1063 cs %N = 2.85 ~ sulphated ash ~ 19.5 Example 5 The procedure ~f Exa~ple 4 was repeated. The initial reactipn mixture was:-371g sulphurised alkyl phenol 278g C12 alkyl phenol 110 g diethylene triamine 60 g paraformaldehyde 50Qcc toluene To the reaction product was added:-80g Ca(OH)2 150g lOOSN oil 200g ethylene glycolTo the neutralised product was added 27g C02 and 200g diluent oil was added to the carbonated neutralised product.
Product analysis:-Ca 3.52%
S 3.10%
10 Yis2lQ 26Qcs A.Y. 21Qmg KOH/g Sulphated ash 12.Q%
Example 6 The procedure of Example 4 was repeated. The initial reac-tion mixture was:-2~7g sulphurised alkyl phenol 334g C12 alkyl phenol lQag diethylene triamine 55g paraformaldehyde 5QOcc toluene To the reaction product was added:-2QQg diluent oil 8Qg Ca(OH~2 200g ethylene glycol To the neutralised product ~as added 30g C02 at 150C. Following this 160 ml diluent oil was added.

1094~S3 Product anal,~sis:-Ca 3.86%
S 2.54%
~.V. 219 ~g ~0 ~ g V~8210 2~2.3cs Sulphated ash 13.4%
E~am~le C
Preparation of Mannich base 8896g of a C12 alkyl phenol and 31 toluene were mised together and to the mixture was added 1652g diethylene triamine and 960g paraformaldehyde. The misture was then heated to refluY and the water formed was removed by azeotropic distillation via a Dean and Stark condensation syst~m.
The product was washed with water and finally vacuum stripped to remove the toluene.
AnalYsis of ~roduct Mannich base % N = 5.69 A.V. = 253 mg E0 ~ g V210 = 439 C9.
Examnle D
Prenaration of sul~huri~ed aLkvl~henol 2224g of C12 alkylphenol, 642g sulphur and 144g calcium hydroxide were heated to 125C at which temperature 82.5g ethylene glycol was added. The temperature was increased to 150C and the pressure reduced to 210 mm Hg at which value it was held for 1 hour. The product was then vacuum stripped for 2 hours at 190C and 50 mm Hg pressure.
Anal~is of sul~hu _~ed alk~ Phenol A.V. = 79.6 mg E0 ~ g ~o ca = 2.73 % s = 14.1 -- 20 _ `` iOS 4~S3 E~a~D~,e 7 Pre~ar~tlon of lubrica~t ~dditivo 239g of the Mannieh ba~e product from Esample C,lllg of the sulphuri~ed slkyl phenol from E~ample D ant 122g lube oil were heated to 125C when 376 ealciu~ hydroside, 120g ethylene glycol and 3g aeetie seid were added.
The misture wa~ thon heat~d at 125C for 15 minutes at 500 mm ~g pressure and then for 1 hour at 150C. 25g solid carbon dioside wa~ add d before the mi~ture wa~ vaeuum stripped st 185C and 5Qmm ~g pressure for 15 minutes.
On eooling the produet was diluted with 53g lube oil and then filtered through a distomaceous earth filter pad.
The analysis of the produet is given in the following Table 2.
E~am~le 8 Esample 7 was repeated eseept that 6g acetic acid were added.
.~, Esample 7 wa~ repeated escept that 1.5g acetic acid was added.

Co~p,a,rison Test 2 Esample 7 was repeated escept that neither carbon dioxide or acetic acid were added.

Esam~le 10 Es~mple 7 was repeated elcept that no acetic acid was added.

Com~ari~on Test ~

Esample 7 was repeated escept that no carbon dioxide was added.

`` lQ~40~3 T~BL~ 2 E2ample ¦ =g-~O~ g¦ Vcl¦ ~N ¦ %

Comparison Test 2 216 594 2.49 4.11 Essmple 10 207 423 2.50 4-15 Compari~on Test 216 577 2.42 3.85 E~ample 7 205 259 2.30 3-96 E~ample 8 198 321 2.65 4.00 E~ample 9 204 256 2.46 4.06 ~amples ~ to D snd Co~parison Tosts 1 to 3 are not E~amples ac¢ording to the invention.
~am~le 11 Co~atabilit~ Tests The products of E~amples 1 to 3 and the Compari~o~ Test 1 ~ere blended ~ith BP ~V150 lubricating oil to ~n ~.VO of 110 and allo~ed to atand. ~fter 21 days the blends remained compatible.
Exam~le 12 A. Pre~aration of Sul~hurised ~lkvl Phenol 1 mole C12 - alkyl phenol, 0.25 mole Ca(OH)2 and 2.5 mole sulphur were charged to a reaction vessel and the temperature raised to 125C. Ethylene glycol r qual to 0.55 ~ weight of Ca(OH) was added and the temperature raised to 150C. Vacuum wa~ applied and the pre~ure set at 503mm Hg pressure for 1 hour. The reaction mixture wa~ then vacuum stripped at 195C (base temperature) under ma~imum vacuum for 2 houro, after which it was cooled and diluted with lube oil.
B. PreParation of Mannich Base 1 mole C12 - alkyl phenol and 0.5 mole diethylene triamine (DETA) were charged to a flask. 1 mole paraformaldehyde was 910wly las~40s3 added causing an e20thermic reaction. The temperature was slol~ly raised to 130C at which value it ~as held for 2 hours ~hilst l~ater ~as removed via a Dean and Stark trap. The reaction misture was then vacuum stripped to remove residual water and ~olvent and then diluted with oil.
C. Pre~aration of Product 0.6 moles of the Mannich Base B, 0.4 moles of the sulphurised alkyl phenol and lube oil were mised in a reaction flask which was heated to 125C. 1 mole of lime and ethylene glycol ~.25 2 weight of lim~s~7 were added. The pressure was then reduced to 500 ~ Hg pressure and the temperature maintained at 125C for 15 minutes.
The temperature was then raised to 150C for 1 hour.
55~ by weight, based on the weight of the raaction mi~cture, of solid carbon dioxide was then added whilst maintaining the reaction temperature at 150C and the pressure at atmospheric.
The reaction product was vacuum stripped to 50 mm Hg pressure at 185 C base temperature, cooled and diluted with lube oil to give 33% oil in finished product.
Finally the product was filtered.
The analysis of the product in terms of its A.V., Vis210, ~Ca, %N and ~S is given in Table 3.
EsamPle 13 Esample 12 was repeated u8ing the quantities of reactants shown in Table 3 .
E~ample 14 Esample 12 was repeated using the quantities of reactants shown in Table 3 .
Exam~le 15 Esample 12 was repeated using the quantities of reactants ghown in Table 3 .

10~0~3 E~am~le 16 Esample 12 ~as reFeated using the quantities of reactants shown in Table 3.
E~am~le 17 E~ample 12 was repeated using the quantities of reactants sho~n in Table 3.
E~am~le 18 En~ine Evaluation Solutions of the products of Examples 12 to 17 were dissolved in a lubricant base oil, as W8S a conventional prior art additive (calcium phenate) to an alkalinity value of 25 mg KOH/g. The solutions were then evaluated in the Ring Belt Merit test in a Petter AVI engine running under standard conditions but modified to run on residual fuel containing appro~imately 2.8% sulphur.
The oil containing calcium phen&te was run a~ a reference before and after the candidate oil and the candidate oil judged by a figure of merit (F.O.M.) in which 1.0 represents the value for the reference oil. Since the accuracy of the te~t is + 0.1 an F.O.M. for a candidate of 0.9 to 1.1 is taken as an indication of a comparable degree of piston cleanline~s.
The Ring Belt Merit (R.B.M.) derived from the average ratings of the four lands and three grooves on the piston was also observed.
The results of the R.B.~. and F.O.M. ob~ervations are given in Table 3.

10~053 ~ C _ ~ o o o O O 0 _~ O O O
ZU; ~ _ ~ m ~_ ~ ,~ ~D

v~ ~ ~ ~ ~o a) ~
O N N N N N N

c~, _, t- t~l a~ ~
ID ~~O ~ a~ ~1 ~

~-I N _ N_ _ _ ~ID
v~ ~a) ~_d O C~l 1 ~~i O_1 ~I,_1 ~ ~ ~1 ~4 N _ O
0 ~ 00 ,0~ O ~ O .C
~ ~ d- ~ 1~ 1<~ ~ ~1 ~ ~pqD O~ ~ O O ~, a,~, q~ ~
_ _ _ __ JN

~'~V U~ ~ ~ ~ ~ ~ _~
0~ _ ~
~ ~1 ~ ~ ~ ~1 ~ _1 ~4 ~ E~ 0_~ t~
0 ~ ~ ~ _ J
_~ O O O O O O

~ D ~ ~D ~D ~D ~D
~ ~1 O O O O o O a>
. .
~ ~_ _l O O O

:1~ ~i~ U~ U~ U~ ~ U~ U~ Po o ~ O O O O o O

_ X~ __ __ _ _ G
~1 N ~ - ~ O _l _ ~S _

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A compound suitable for use as a lubricating oil additive comprising the reaction product obtained by neutralising with an alkaline earth metal oxide or hydroxide a sulphurised alkylphenol containing from 4 to 20 weight percent sulphur in admixture with a Mannich base containing from 2 to 10 weight percent nitrogen and having a molecular weight of from 600 to 5,000 and prepared from an alkylphenol, formaldehyde and an alkylene or polyalkylene polyamine having the structural formula:-H2N ? alkylene - NH ? n H (I) wherein n is an integer from 1 to 10 and the alkylene group has from two to eight carbon atoms, the neutralisation being carried out in the presence of a hydroxylic solvent and at an elevated temperature, and thereafter reacting the neutralised product with carbon dioxide.

2. A compound according to claim 1 wherein at least 90% of the sul-phurised alkylphenol is comprised of sulphurised alkylphenols having the struc-tural formula:-(II) wherein R2 is an alkyl group containing from 8 to 36 carbon atoms, y1 is an integer in the range from 1 to 9 and n1 is an integer in the range from 1 to 5.

3. A compound according to claim 2 wherein in the sulphurised alkyl phenol of formula (II) R2 is an alkyl group containing from 10 to 30 carbon atoms with the average number of carbon atoms being in the range of about 10 to 26, y1 is an integer in the range from 1 to 5, averaging over the entire composition in the range from about 2 to 4, and n1 is an integer from 1 to 3.

4. A compound according to claim 2 wherein R2 in the sulphurised alkyl-phenol composition of formula (II) is predominantly in the para-position.

5. A compound according to claim 1, 2 or 3 wherein the alkylene poly-amine is an ethylene polyamine, a propylene polyamine or a butylene polyamine.

6. A compound according to claim 1, 2 or 3 wherein the alkylene poly-amine is diethylene triamine.

7. A compound according to claim 1, 2 or 3 wherein the polyalkylene polyamine is ethylene diamine, tetraethylene, pentamine or triethylene tetra-mine.

8. A compound according to claim 1, 2 or 3 wherein the alkaline earth metal is calcium or barium.

9. A compound according to claim 1, 2 or 3 wherein the alkaline earth metal oxide or hydroxide is calcium hydroxide.

10. A compound according to claim 1, 2 or 3 wherein the hydroxylic solvent is ethylene glycol, propylene glycol, a butane diol or methanol.

11. A compound according to claim 1, 2 or 3 wherein the reaction pro-duct is obtained by neutralising the Mannich base and the sulphurised alkyl-phenol in admixture in an equivalent ratio (based on phenol) in the range 0.2 to 5:1.

12. A compound according to claim 1, 2 or 3 wherein the reaction product is obtained by adding an amount of alkaline earth metal oxide or hydroxide which provides a total of up to one equivalent of alkaline earth metal present per equivalent of alkylphenol present in the final product.

13. A compound according to claim 1, 2 or 3 wherein the reaction product is obtained by adding an amount of alkaline earth metal oxide or hydroxide which provides a total of less than 1.75 equivalents of alkaline earth metal present per equivalent of alkylphenol present in the final product.

14. A compound according to claim 1, 2 or 3 wherein the hydroxylic solvent is ethylene glycol in an amount of from 5 to 35 weight percent of the total reaction mixture.

15. A compound according to claim 1, 2 or 3 wherein the reaction pro-duct is obtained in the presence of an inert diluent in an amount of from 3 to 65 weight percent of the total reaction mixture.

16. A compound according to claim 1, 2 or 3 wherein the reaction pro-duct is obtained in the presence of a foam suppressant in an amount of from 1 x 10 -3 to 1 x 10 -5 percent.

17. A compound according to claim 1, 2 or 3 wherein the reaction pro-duct is obtained by mixing the sulphurised alkyl phenol, the Mannich base and the alkaline earth metal oxide or hydroxide and heating to a temperature of from 90 to 140°C prior to addition of ethylene glycol as hydroxylic solvent.

18. A compound according to claim 1, 2 or 3 wherein the reaction pro-duct is obtained by mixing the sulphurised alkyl phenol, the Mannich base and the alkaline earth metal oxide or hydroxide and heating to a temperature of from 90 to 140°C prior to addition of ethylene glycol as hydroxylic sol-vent and, after addition of ethylene glycol, the temperature is raised to a value in the range from 125 to 160°C, thereby removing the water of reaction.

19. A compound according to claim 1, wherein the reaction product is obtained by reacting the sulphurised alkyl phenol with the precursors of the Mannich base to form a product containing sulphurised alkylphenol and Mannich base and thereafter neutralising the product with the alkaline earth metal oxide or hydroxide in the presence of the hydroxylic solvent.

20. A compound according to claim 19 wherein the sulphurised alkyl phenol is reacted with the alkylphenol in an equivalent ratio (based on phenol) in the range of from 0.2 to 5:1, the alkylene or polyalkylene poly-amine being present in an amount of from 1 to 3 moles and the formaldehyde being present in an amount of 0.75 to 1.25 moles for every 1 to 3 moles of alkyl-phenol present in the reaction mixture.

21. A compound according to claims 19 or 20 wherein reaction is carried out in the presence of a hydrocarbon solvent boiling within the range 50 to 200°C in an amount of from 1 to 50% by weight based on the total weight of the reaction mixture.

22. A compound according to claim 19 or 20 wherein the reaction is car-ried out in benzene, toluene or xylene in an amount of from 1 to 50% by weight based on the total weight of the reaction mixture.

23. A compound according to claim 20 wherein reaction is effected at a temperature in the range 50 to 130°C.

24. A compound according to claim 1 wherein the reaction product is obtained by neutralising the sulphurised alkylphenol in admixture with the Mannich base in the presence of a carboxylic acid.

25. A compound according to claim 24 wherein the carboxylic acid is a C1 to C10 carboxylic acid.

26. A compound according to claim 24 wherein the C1 to C10 carboxylic acid is acetic acid.

27. A compound according to claim 24, 25 or 26 wherein the carboxylic acid is present in an amount of from 0.001 to 0.5 moles per mole of alkylphenol present in the reaction mixture.

28. A compound according to claim 24, 25 or 26 wherein the carboxylic acid is present in an amount of from 0.02 to 0.1 moles per mole of alkyl phenol present in the reaction mixture.

29. A compound according to claim 1 wherein the reaction product is obtained by reacting the neutralised product with carbon dioxide in the pre-sence of the hydroxylic solvent.

30. A compound according to claim 29 wherein the carbon dioxide is blown into the neutralised product at the neutralisation reaction temperature.

31. A compound according to claim 29 or 30 wherein the amount of carbon dioxide added is in the range 1 to 15 percent by weight, based on the total weight of the reaction mixture.

32. A compound according to claim 29 or 30 wherein the amount of carbon dioxide added is in the range 1 to 8 percent by weight, based on the total weight of the reaction mixture.

33. A compound according to claim 1 wherein the reaction product is obtained by removing the hydroxylic solvent from the reaction product after reaction with carbon dioxide.

34. A compound according to claim 33 wherein the hydroxylic solvent is removed by raising the temperature to less than 200°C after removing the water of reaction and reducing the pressure sufficiently to allow its distill-ation.

35. A compound according to claim 34 wherein ethylene glycol is removed by raising the temperature to a value in the range 140 to 200°C.

36. A compound according to claim 35 wherein the ethylene glycol is removed at a pressure in the range 0.01 to 0.8 atmospheres.

37. A compound according to claim 33, 34 or 35 wherein the reaction mixture is cooled and an inert diluent added after removal of the ethylene glycol.

38. A compound according to claim 33, 34 or 35 wherein after removal of ethylene glycol the reaction mixture is cooled to a temperature above 150°C, followed by addition of an inert diluent.

39. A compound according to claim 33, 34 or 35 wherein the reaction mixture is cooled and a hydrocarbonaceous lubricating oil is added after removal of the ethylene glycol.

40. A compound according to claim 33, 34 or 35 wherein undesirable in-soluble compounds are filtered off after removal of the hydroxylic solvent.

41. A concentrate composition suitable for formulating finished lubri-cating oils comprising a minor proportion of a hydrocarbonaceous lubricating oil and a major proportion of an additive package consisting of, or containing, the hydroxylic solvent-free compound as claimed in claim 35.

42. A concentrate composition according to claim 41 wherein the additive package consists of the hydroxylic solvent-free compound in an amount up to 95% w/w based on the total weight of the composition.

43. A concentrate composition according to claim 41 wherein the additive package contains at least 5% w/w of the hydroxylic solvent-free com-pound and up to 90% w/w of other additives, based on the total weight of the composition.

44. A finished lubricant composition comprising a major proportion of a lubricant base oil and a minor proportion of the concentrate composition as claimed in claim 41.