NO864381L - HYDROGEN SULFIDE STABILIZED OIL SOLUBLE SULFURED ORGANIC COMPOUNDS. - Google Patents

Abstract

An additive concentrate for lubricating viscosity lubricating oils comprises a major amount of the oil as well as a minor amount of an oil-soluble sulfurized organic mixture consisting of an oil-soluble sulfurized organic compound and an oil-soluble hindered organic amine having a structure which provides steric hindrance. is selected from primary amines and secondary amines in which the hindered amine is present in an amount of from 0.25 to about 2% by weight, based on the weight of the sulfurized organic compound. The hindered amine is preferably a monoamine. with the formula. R'R "R '" - C-NH-R. wherein R ', R "and R" "may be the same or different and be hydrocarbyl or hydrogen ,. but collectively have together from 2 to approx. Carbon atoms, and give the amine steric hindrance, and wherein R 2 is hydrocarbyl or hydrogen. Addition of the hindered amine and optionally a carboxylic acid or an acid anhydride in effective amounts suppresses the emission of hydrogen sulfide from oil-soluble sulfurized organic compounds under conditions of use.

Description

The present invention relates to oil-soluble sulphide organic, such as olefin, compounds with a hindered

A-

amine and optionally an acid anhydride or a carboxylic acid. The preparations have a low odor and improved hydrogen sulphide stability. When a carboxylic acid, a monoester of a polycarboxylic acid or an acid anhydride is used, the preparations also have good clarity.

Until now, various organic oil-soluble sulfur compounds including olefinic organic compounds have been prepared. E.g. Chemical Reviews 65, 237 (1965) relates to sulfurized preparations prepared by reacting an olefin such as isobutene with sulfur under various conditions. The Journal of the American Chemical Society, 60, 2452 (1938), as well as US-PS 3,221,056, 3,419,614, 4,119,550, 4,191,659 and 4,344,854 relate to the reaction of olefins with hydrogen sulphide and elemental sulfur mainly to form mercaptans while sulfides, disulfides and higher polysulfides are formed as by-products.

US-Ps 4,319,614 describes a method for increasing the mercaptan yield by carrying out reactions between olefin and hydrogen sulphide and sulfur at high temperatures in the presence of various basic substances.

US-PS 4,119,550, 4,191,549 and 4,344,854 relate to the production of sulphurised compounds by reacting unsaturated olefinic compounds with a mixture of sulfur and hydrogen sulphide at superatmospheric pressure in the presence of different catalysts or according to different methods.

US-PS 4,360,438 relates to the use of sulfurized natural and synthetic oils as additives in lubricating preparations.

US-PS 3,632,566 and reissue 27,331 disclose that Diels-Alder adducts can be sulfurized to form sulfur-containing compounds that can be used as extreme pressure and anti-wear additives in various lubricating oils.

US-PS 2,999,813 relates to a lubricant composition containing a sulphurised mineral oil and a polyvalent metal dithiocarbamate, while US-PS' 2,265,851 further relates to the use of coupling agents such as alcohols, esters, ketones and other suitable stable oxygen-containing substances.

Similarly, US-PS 2,394,536 relates to lubricating oil mixtures containing a combination of organic sulphides and salts of dithiocarbamic acids.

US-PS 2,805,996 relates to the use of amine-dithiocarbamate complexes in lubricating oil mixtures and US-PS 2,947,695 relates to the use of mixtures of polyvalent metals in thiocarbamates in the manufacture of oil-soluble additive mixtures for use in the manufacture of lubricating oils.

Although the above-identified documents generally relate to the preparation of various oil-soluble sulfur compounds, they do not relate to hydrogen sulfide stabilization thereof.

US-PS 4,409,114 relates to hydrogen sulfide suppressing additives for functional fluids. However, this patent concerns the use of sulfurized amine compounds containing a metal.

Accordingly, it is an aspect of the present invention to provide an oil-soluble sulfurized organic preparation that suppresses the emission of volatile sulfur compound in additive formulations, comprising an oil-soluble sulfurized organic compound, and an inhibiting organic amine, this being soluble in the oil-soluble sulphurised organic compounds.

It is a further aspect of the invention to provide an oil-soluble sulfurized organic mixture which suppresses emission of volatile sulfur compound in additive formulations, comprising an oil-soluble sulfurized organic compound, a hindered organic amine, this being soluble in the oil-soluble sulfurized organic mixture, and at least one carboxylic acid, a monoester of a polycarboxylic acid or an acid anhydride. According to the invention, oil-soluble sulphurized organic mixtures are improved with respect to r^S emission and also often with respect to smell. When a carboxylic acid or an acid anhydride is used, the sulphurised organic mixtures also have good clarity.

The oil-soluble mixtures according to the invention comprise at least one oil-soluble sulphurous organic compound.

A wide range of sulphurised organic compounds can be used according to the invention, and these compounds can generally be represented by the formula:

where S means sulphur, x is an integer from 1 to approx. 10 and R and R^ can be the same or different organic groups. The organic groups can be hydrocarbon groups or substituted such, containing alkyl, aryl, aralkyl, alkaryl, alkanoate, thiazole, imidazole, phosphorthionate, B-ketoalkyl groups, etc. The essentially hydrocarbon groups can contain other substituents such such as halogen, amino, hydroxyl, mercapto, alkoxy, aryloxy, thio, nitro, sulfonic acid, carboxylic acid, carboxylic acid ester, etc.

Specific examples of types of sulfurized mixtures that are usable according to the invention include aromatic, alkyl or alkenyl sulfides and polysulfides, sulfurized olefins, sulfurized carboxylic acid esters, sulfurized ester olefins, sulfurized oils and mixtures thereof. The production of such oil-soluble sulphurised mixtures is described in the known technique.

The sulphurised organic compounds used according to the invention can be aromatic and alkyl sulphides such as dibenzyl sulphide, dixyl sulphide, dicetyl sulphide, diparaffin wax sulphide and polysulphide, cracked voxoleum sulphides, etc. A method for producing the aromatic and alkyl sulphides includes the condensation of a chlorinated hydrocarbon with an inorganic sulphide whereby the chlorine atom from each of two molecules is displaced and the free valence from each molecule is combined into a divalent sulfur atom. Generally, the reaction is carried out in the presence of elemental sulphur.

Examples of dialkenyl sulfides are described in US-PS 2,446,072. These sulfides can be prepared by reacting an olefinic hydrocarbon of from 3 to 12 carbon atoms with elemental sulfur in the presence of zinc or a similar metal, generally in the form of an acid salt. Examples of sulfides of this type include 6,6'-dithiobis(5-methyl-4-nonene), 2-butenyl monosulfide and disulfide, and 2-methyl-2-butenyl monosulfide and disulfide.

The sulfurized olefins according to the present invention include sulfurized olefins produced by reacting an olefin (preferably containing 2-6 carbon atoms), or a low molecular weight polyolefin derived therefrom, with a sulfur-containing compound such as sulfur, sulfur monochloride, sulfur dichloride, hydrogen sulfide and combinations thereof.

The sulfurized organic compounds used in the mixtures according to the invention can be sulfurized oils that can be produced by treating natural or synthetic oils including mineral oil, lard oil, carboxylic acid ethers derived from aliphatic alcohols and fatty acids or aliphatic carboxylic acids (e.g. myristyl oleate and oleyl -oleate) sperm whale oil and synthetic sperm whale oil substitutes and synthetic unsaturated esters or glycerides. Stable sulphurised mineral lubricating oils can be obtained by heating a suitable mineral lubricating oil with from approx. 1 to 5% sulfur to a temperature above approx. 175°C and preferably approx. 200 to approx. 260°C for several hours to obtain a reaction product which is essentially non-corrosive to copper. The mineral lubricating oils which are sulphurised in this way can be distillate or residual oils obtained from paraffinic, naphthenic or mixed base raw materials. In the same way, sulphurised fatty oils, such as sulphurised lard, can be obtained by heating lard with approx. 10-15% sulfur to a temperature of approx. 150°C for a period of time sufficient to obtain a hemogenic product.

The sulphurised fatty acid esters which can be used in the mixtures according to the invention can be produced by reacting sulphur, sulfur monochloride and/or sulfur dichloride with an unsaturated fatty ester at elevated temperatures. Typical esters include C^_ 2q alkyl esters of Cg_24<u>saturated fatty acids, such as palmitoleic, oleic, ricinol, petrosal, vaccenic, linoleic, linolenic, oleostearic, licanic acid, etc. Sulfurized fatty acid esters are prepared from mixed unsaturated fatty acid esters as obtained from animal fats and vegetable oils such as tall oil, linseed oil, olive oil, castor oil, peanut oil, rapeseed oil, fish oil, sperm oil, etc.

can also be used. Specific examples of fatty acid esters that can be sulfurized include lauryl phthalate, methyl oleate, ethyl oleate, lauryl oleate, cetyl oleate, cetyllinoleate, lauryl ricin oleate, oleolin oleate, oleostearate, and alkyl glycerides.

Another class of organic sulfur-containing compounds includes sulfurized aliphatic esters of an olefinic mono-dicarboxylic acid. E.g. aliphatic alcohols with from 1 to 30 carbon atoms can be used to esterify monocarboxylic acids such as acrylic acid, methacrylic acid, 2,4-pentadiene acid, etc., or fumaric acid, maleic acid, muconic acid, etc. Sulfurization of these esters is carried out with elemental sulfur, sulfur monochloride and/or sulfur dichloride.

Another class of sulfurized organic compounds

which can be used in the mixtures according to the invention are diester sulphides which are characterized by the formula

Iivor x is from approx. 2 to approx. 5, y is from 1 to approx. 6, preferably 1 to approx. 3, and R is an alkyl group with from approx. 4 to approx. 20 carbon atoms. This R group can be straight-chain or branched which is large enough to maintain the solubility of the compounds of the invention in the oil. Typical diesters include butyl, amyl, hexyl, heptyl, octyl, nonyl, decyl, tridecyl, myristyl, pentadecyl, cetyl, heptadecyl, stearyl, lauryl and eicosyl diesters of thiodialkanoic acids such as propion -, butanoic, pentanoic and hexanoic acid. Of the diester sulfides, a specific example is dilauryl, 3,3<1->thiodipropionate.

Preferably, the sulphurised organic compound used in the mixtures according to the invention comprises sulphurised olefins. E.g. organic polysulfides can be prepared by sulfochlorination of olefins containing four or more carbon atoms and further treatment with inorganic higher polysulfides according to US-PS 2,708,199. In one embodiment, sulfurized olefins are prepared by (1) reacting sulfur monochloride with a stoichiometric excess of a low carbon atom olefin, (2) treating the resulting product with an alkali metal sulfide in the presence of free sulfur in a molar ratio of not less than 2:1 in a alcohol-water solvent, and (3) reacting this product with an inorganic base. This procedure is described in US-PS 3,471,404 and reference is made thereto for the discussion of this procedure. In general, the olefin reactant contains from approx. 2 to 6 carbon atoms and examples include ethylene, propylene, butylene, isobutylene, amylene etc., in short, in the first step sulfur monochloride is reacted with from 1 to 2 moles of olefin per moles of sulfur monochloride, and the reaction is carried out by mixing the reactants at a temperature of approx. 20-80°C. In the second step, the product from the first step is reacted with an alkali metal, preferably sodium sulphide and sulphur. The mixture consists of up to approx. 2.2 mol of the metal sulphide per g atom of sulphur, and the molar ratio between alkali metal sulphide and products from the first step is approx. 0.8 to approx. 1.2 mol metal sulphide per moles of product from step 1. In general, the second step is carried out in the presence of an alcohol or an alcohol-water mixture under reflux conditions. The third step in the process is the reaction between the phosphosulfurized olefin which contains from approx. 1 to approx. 3% chlorine with an inorganic base in a water solution. Alkali metal hydroxide, such as sodium hydroxide can be used. The reaction is carried out until the chlorine content is reduced to below 0.5% and this reaction is carried out under reflux conditions for a period of 1-24 hours.

The sulphurised olefins which can be used in the mixtures according to the invention can also be produced by reaction under superatmospheric pressure of olefinic compounds with a mixture of sulfur and hydrogen sulphide in the presence of a catalyst, followed by the removal of low-boiling substances. This procedure for the production of sulphurised mixtures which can be used according to the invention is described in US-PS 4,191,659, to which reference is made for the preparation of usable sulphurised mixtures. An eventual final step described in the patent is the removal of active sulfur by e.g. treatment with an alkali metal sulphide.

Other methods for producing sulphurised olefinic compounds for use according to the invention are set out in US-PS 4,119,550 and 4,344,854 which generally relate to the reaction of saturated or unsaturated olefinic compounds with a mixture of sulfur and hydrogen sulphide under superatmospheric pressures, followed by removal of low-boiling substances. Reference is made to these patents.

The olefinic compounds which can be sulfurized by this method and used in the mixtures according to the invention are of different types. They may contain at least one olefinic double bond which is defined as a non-aromatic double bond; i.e. one that connects two aliphatic carbon atoms. In the most general sense, the olefin can be defined by the formula:

12 3 4

wherein each of R , R , R , and R is hydrogen or an organic group. In general, the R elements in the formula that are not hydrogen can be satisfied by groups such as -(R<5>)3, -COOR<5>,

-CON(R<5>)2, -COON(R<5>)4, -COOM, -CN, -X, -YR<5>or -Ar:

in which

each R 5 independently is hydrogen, alkyl, akenyl, aryl, substituted alkyl, substituted alkenyl or substituted aryl, provided that any two R 5 groups may be alkylene or substituted alkylene forming a ring of up to 12 carbon atoms;

M is one equivalent of a metal cation, preferably from group 1 or 2, e.g. sodium, potassium, barium, calcium;

X is halogen, e.g. chlorine, bromine or iodine;

Y is oxygen or divalent sulfur; and

Ar is an aryl or substituted aryl group with up to approx.

12 carbon atoms.

Any of R<1>, R<2>, R<3> and R<4> can also together form an alkylene or substituted alkylene group, i.e. the olefinic group must be alicyclic.

The nature of the substituents in the substituted moieties as described above is usually not critical and any such substituent is useful as long as it is or can be made compatible with the lubrication environment and does not group under the intended reaction conditions. Thus, substituted compounds which are so unstable that they decompose in a harmful manner under the reaction conditions used are not covered by this thought. However, certain substituents, such as keto or aldehyde, may undergo sulphuration in the desired manner. The choice of suitable substituents is within the scope of the expert and can be determined by routine testing. Typical of such substituents include any of the above moieties as well as hydroxy, amidine, amino, sulfonyl, sulfinyl,'sulfonate, nitro, phosphate, phosphite, alkali metal, mercapto, and the like.

The olefinic compound is usually one in which each R

which is not hydrogen independent is alkyl, alkenyl or aryl, or somewhat less commonly a similarly substituted group. Monoolefinic and diolefinic compounds, especially the former, are preferred, and especially terminal monoolefin-3 4

ical hydrocarbons, i.e. those compounds where R and R are hydrogen and R 1 and R 2 are alkyl or aryl, especially alkyl, i.e. that the olefin is aliphatic. Olefinic compounds with approx. 3 to 30 and preferably 3 to 16, preferably 9 or less, and most preferably 8 carbon atoms, are particularly desirable.

Ethylene, isobutene, propylene and oligomers thereof are particularly preferred olefinic compounds. Of these compounds, isobutylene and diisobutylene are particularly desirable, because of their availability and the particularly high-sulphur compounds that can be prepared from them.

Commercial sources of sulfur and hydrogen sulphide are usually used for the purposes of the invention and impurities which are usually associated therewith may be present without particularly unfavorable results. Thus, commercial diisobutene is believed to contain essentially two isomeric forms and this mixture is believed to be able to be used according to the invention.

The amines used according to the invention are hindered organic amines. By the term "hindered" it is meant that the organic amine has steric hindrance in it. The hindered organic amine is also soluble in the oil-soluble sulfurized organic compound. This means that based on

100 parts by weight of the oil-soluble sulfurized organic compound, the solubility of the amine is at least 0.01 parts by weight, preferably at least 5 parts by weight, preferably at least 10 parts by weight

divides up to a large excess of said amine, such as e.g. 10,000 parts by weight. Preferably, the organic amine compound is added in an effective amount to suppress the emission of volatile sulfur compounds and/or to reduce the smell. According to this, the amount of hindered organic amine used according to the invention can be from approx. 0.1 to approx. 20% by weight and preferably from approx. 0.25 to approx. 2.0% by weight, calculated on the weight of the oil-soluble sulfur compound in the mixture.

The hindered organic amine can either be a polyamine or rather a monoamine. The organic amine can also contain unsaturated hydrocarbon groups but is preferably saturated. Suitable amines include hydrcarbylamines having from 3 to about 100 carbon atoms and preferably from 3 to approx. 30 carbon atoms such as aliphatic amines, aromatic amines or combinations thereof, e.g. aliphatically substituted aromatic amines. Preferably, the hydrocarbyl group is an alkyl group.

Desired hindered hydrocarbylamines according to the invention have the formula

where R', R" and R'" can be the same or different. R',

R" and R'" can be a hydrocarbyl such as aromatic, aliphatic or combinations thereof, or hydrogen, but regardless of the arrangement or content of any particular R', R", R'" substituent, they collectively have 2 to about 30 carbon atoms. That is that at least one of the R', R" or R<1>" substituents must contain one or two carbon atoms. Preferably R', R" are

and R<1>" alkyl. A preferred total number of carbon atoms for R', R" and R'" is from about 12 to 14. R<2> and R<3> considered may be the same or different and may also be hydrocarbyl or hydrogen However, these have

collectively from 0 to approx. 30 carbon atoms. Preferably R 2 and R 1 are alkyl with a total of 0 to 4 carbon atoms, but preferably both are hydrogen. Thus, desirable amines according to the invention include t-octylamine and the like. A commercially available compound is "Primene JM-T" which is a mixture of isomeric amines having from 18 to 22 carbon atoms or "Primene 81-R" which is a mixture of isomeric amines having from 12 to 14 carbon atoms.

The oil-soluble sulfurized organic compound is often used as a metalworking additive. According to this, the sulphurised organic compounds according to the invention in connection with the hindered organic amine, generally find use in additive formulations. Production of an additive concentrate etc., containing the oil-soluble sulphurised organic compound and the hindered organic amine can use any conventional or usual mixing method, such as e.g. only adding one to the other. Normal stirring is used to mix the components.

It has unexpectedly been found that the use of at least one carboxylic acid or an acid anhydride in combination with a hindered amine,

in the oil-soluble sulfurized organic compound, generally provides good clarity as well as improved hydrogen sulfide stability and low or no odor. Although monocarboxylic acids can be used, polycarboxylic acids are preferred. The hydrocarbon part of the acid can be saturated or unsaturated. The acid contains at least 2 carbon atoms such that from approx. 2

to approx. 100 carbon atoms and preferably from approx. 3 to approx.

30 carbon atoms. Examples of saturated monocarboxylic acids include acetic, propionic, butyric, lauric, palmitic, stearic and the like. Examples of saturated dicarboxylic acids include oxalic, malonic, succinic, glutaric, adipic, pimilic and the like. Examples of suitable unsaturated acids include acrylic, maleic, fumaric and the like. A suitable acid according to the invention is a substituted succinic acid with the formula

where R is a hydrocarbyl group with at least 10 carbon atoms. In general, R has from approx. 10 to approx. 100 carbon atoms, preferably from approx. 10 to approx. 30 carbon atoms, with suitably 9 to 15 carbon atoms being preferred. The R substituent in the above formula is preferably alkenyl. Furthermore, it is often a low molecular weight olefinic hydrocarbon reactant such as tetrapropyl, triisobutylene, tetraisobutylene and the like. Such low molecular weight substituents are monoolefins and have a branched structure. A very preferred acid according to the invention is polypropenyl succinic acid. Included within the definition of the carboxylic acids are mono-esters of polycarboxylic acids. These compounds are derived from the above-mentioned polycarboxylic acids or anhydrides thereof, and can thus contain the same number of carbon atoms in the acid part as well as being saturated or unsaturated as stated above. As for the monoester group, this generally has from approx. 1 to 100, and preferably from 1 to approx. 30, preferably from 1 to approx. 10 carbon atoms. The monoester group can also contain one or more hydroxy groups with a hydroxy group as preferred. Accordingly, the monoester group is generally a hydrocarbyl or a hydroxyhydrocarbyl with an alkyl or a hydroxyalkyl group being preferred. A suitable monoester of a polycarboxylic acid has the formula

or

where R is as indicated above, i.e. a hydrocarbyl group with from approx. 10 to approx. 100 carbon atoms and the like, and R is the monoester group and has ' according to this from 1 to approx. 100, preferably from 1 to approx. 30 and preferably from 1 to approx. 10 carbon atoms. As noted, R<3> can be hydrocarbyl or hydroxyhydrocarbyl and preferably alkyl or hydroxyalkyl.

In combination with or instead of such a carboxylic acid, an acid anhydride can be used. The acid anhydrides are derivatives of the above-mentioned polycarboxylic acids. Thus, the acid anhydrides will have from approx. 4 to approx. 100 carbon atoms with from 4 to approx. 30 as preferred. Inasmuch as the acid anhydrides are derivatives of the above-mentioned polycarboxylic acids, the description of these shall not be repeated, only reference shall be made to it. Examples of acid hydrides include acetic anhydride, propionic anhydride, succinic anhydride, glutaric anhydride and the like.

The relative amount of carboxylic acid or acid anhydride in relation to hindered organic amine is generally important or critical. The amount of carboxylic acid, monoester of a polycarboxylic acid, acid anhydride or combinations thereof, in relation to the amine, is generally from approx. 0.1 to approx. 20, preferably from approx. 0.25 to approx. 2.0 and preferably approx. 1:1 on a weight basis. The effective amount of the carboxylic acid or anhydride will vary somewhat depending on the type of specific acid or anhydride, type of sulfur compound, etc. Usually used from approx. 0.1 to approx. 20% by weight and preferably from approx.

0.25 to approx. 2 wt% acid and/or anhydride based on the total weight of oil-soluble sulfurized organic compound. Characteristically, an amount is used so that it is achieved

a good clarity in the oil-soluble sulphurised organic mixture. Although the carboxylic acid, monoester or anhydride in itself need not be soluble in the oil-soluble sulphurised organic compound, it should, in combination with the hindered amine, be soluble in said

organic compound.

The preparation of the oil-soluble sulfurized organic mixture containing the sulfurized organic compound, hindered organic amine and carboxylic acid and/or anhydride can be any conventional method. Often, the different components can simply be mixed at room temperature.

As indicated above, the compositions of the invention have improved hydrogen sulfide stability, low odor and good clarity. The mixtures are particularly suitable as metalworking additives, as additive concentrates and the like.

The invention shall be explained in more detail with reference to

the following examples.

Examples 1-7.

A 40% sulphurised olefin is produced by reacting sulphur, r^S and diisobutylene, i.e. 96 g (3 mol) of sulfur are charged to a jacketed high-pressure reactor which is equipped with agitators and internal cooling coils. Cooled salt solution is circulated through the coils to cool the reactor prior to introduction of gaseous reactants. After sealing the reactor, evacuation to approx. 2 torr and cooling, 224 g (2 mol) and diisobutylene and 34 g (1 mol) of hydrogen sulphide are added to the reactor. The reactor is heated using steam in the outer jacket, to a temperature of approx. 171°C

for 1.5 hours. A maximum pressure of 1350 psig is reached at approx. 168°C during the heating. Before reaching the reaction temperature, the pressure begins to drop and continues to drop as the gaseous reactants are consumed. After approx. 10 hours at a reaction temperature of approx. 171°C, the pressure is approx. 310

to approx. 340 psig and the rate of pressure change approx.

5-10 psig per hour. Unreacted hydrogen sulphide and the diisobutylene are vented to a recovery system. After the pressure in the reactor has dropped to atmospheric pressure, it is covered with sulphur-

stirred the mixture as a liquid. The mixture is blown with nitrogen and then vacuum stripped to remove low-boiling substances including unreacted•diisobutylene, mercaptans and monosulphides. The filtrate is the desired sulphurised preparation containing approx. 40% by weight of sulphur. Various amounts of "Primene 81-R" were added as indicated in Table IA. "Primene 81-R" is a commercially available tertiary alkylamine and is essentially a mixture of isomeric amines containing from 12 to 14 carbon atoms. The components were mixed for a very short time and then tested for clarity and hydrogen sulphide. Hydrogen sulfide was determined quantitatively. The results are given in Tables IA and IB.

As can be seen from Tables IA and IB, the addition of the hindered amine had a dramatic effect on the reduction of hydrogen sulfide formed over a period of 1 week or 1 month. However, the resolutions showed different degrees of blur.

Examples 8-13.

After the addition of various carboxylic acids, the degree of turbidity was greatly reduced as indicated in Table II.

As can be seen from Table II, the turbidity conditions that occur when using a hindering amine were greatly reduced. Furthermore, the amount of vapor space hydrogen sulfide in all examples except Example 8 was very low or zero.

It should thus be clear that emission of volatile sulfur compounds was suppressed. The smell in examples 2-7

and 9-13 was also reduced.

The sulfurized mixtures according to the invention can be effectively used in a number of lubricating mixtures formulated for a number of purposes. These lubricating compounds are based on different oils of lubricating viscosity including natural and synthetic lubricating oils and mixtures thereof. These lubricating compositions containing the present additive concentrates are effective as crank lubricating oils for spark-ignition and compression-ignition engines including automobile and tractor engines, two-stroke engines, aircraft piston engines, marine and light-duty diesel engines, and the like. Furthermore, automatic transmission fluids, axle lubricants, gear oils, metalworking lubricants, hydraulic fluids and other lubricating oils and grease mixtures can benefit from the incorporation of the present additive concentrates.

Natural oils include animal oils and vegetable oils (eg, castor oil, lard oil) as well as mineral lubricating oils such as liquid petroleum oils and solvent-treated or acid-treated mineral lubricating oils of the paraffinic, naphthenic or mixed type. Oils of lubricant viscosity derived from coal or shale may also be used. Synthetic lubricating oils include hydrocarbon oils and halogen-substituted ones, such as polymerized and interpolymerized olefins (eg, polybutylenes, polypropylenes, propylene isobutylene copolymers, chlorinated polybutylenes, etc.), poly(1-hexenes), poly(1-octenes ) , poly(1-dekenes) etc. and mixtures thereof; alkylbenzenes (eg, dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di-(2-ethylhexyl)benzenes, etc.); polyphenyls (eg biphenyls, terphenyls, alkylated polyphenyls, etc); alkylated diphenyl ethers and alkylated diphenyl sulphides and derivatives, analogues and homologues thereof, etc.

Alkylene oxide polymers and interpolymers and derivatives thereof in which the terminal hydroxyl groups have been modified by esterification, etherification, etc., constitute another class of known synthetic lubricating oils that can be used. These are exemplified by the oils produced by polymerization of ethylene oxide or propylene oxide, alkyl and aryl ethers of these polyoxyalkylene polymers, (e.g. methylpolyisopropylene glycol ether with an average molecular weight of approx. 1000, diphenyl ether of polyethylene glycol with a molecular weight of approx. .500-1000, diethylethers of polypropylene glycol with a molecular weight of about 1000-1500, etc.) or mono- and polycarboxylic acid esters thereof, e.g. acetic acid esters, mixed C3_g fatty acid esters or the C3_oxo acid diester of tetraethyleneglyco.

Another suitable class of synthetic lubricating oils which may be used include esters of dicarboxylic acids (e.g., phthalic, succinic, alkyl succinic, alkenyl succinic, maleic, azelaic, suberyl, sebacyl, fumaric, adipic, malonic , alkylmalonic, alkylmalonic acid, linoleic acid dimer, malonic acid, alkylmalonic acid, alkenylmalonic acids etc), with a number of different alcohols (e.g. butyl alcohol, hexyl alcohol, -dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol etc) Specific examples on these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of the linoleic acid dimer, the complex ester formed by the reaction of 1 mol sebacic acid with 2 mol tetraethylene glycol and 2 mol 2-ethylenehexanoic acid, etc.

Esters that can be used as synthetic oils include

also those produced from C 1 - carboxylic acids and polyols and polyol ethers such as neopentylglycol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol etc.

Silicone-based oils such as polyalkyl, polyacrylic, poly-alkoxy, or polyaryloxy-siloxane oils and silicate oils comprise another useful class of synthetic lubricants (e.g., tetraethyl silicate, tetraisopropyl silicate, tetra-(2-ethylhexyl)silicate, tetra-(4 -methylhexyl)silicate, tetra-(p-tert-butylphenyl)silicate, hexyl-(4-methyl-2-pentoxy)-disiloxane, poly(methyl)siloxane, poly(methylphenyl)siloxane, etc. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids (e.g. tricresyl phosphate, trioctyl phosphate, the diethyl ester of decanephosphonic acid, etc.), polymeric tetrahydrofurans, etc.

Unrefined, refined and re-refined oils, either natural or synthetic (as well as mixtures of two or more of any of these) of the type described above, can be used in the concentrates according to the invention. Unrefined oils are those obtained directly from a natural or synthetic source without further purification. For example is a shale oil obtained directly from retorting, a petroleum oil obtained directly from primary distillation or ester oil obtained directly from an esterification process and used without further treatment, an unrefined oil. Refined oils are similar to unrefined oils, except that they have been further processed in one or more purification steps to improve one or more properties. Many such frontier techniques are well known to those skilled in the art such as solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, etc. Re-refined oils are obtained by processes similar to those used to obtain refined oils, applied to refined oils that have already been in use. Such overrefined oils are also known as reprocessed oils and are often further processed by techniques aimed at removing used additives and oil degradation products.

In general, the above-mentioned lubricants contain an amount of one or more oil-soluble sulfur preparations according to the invention to a sufficient extent to give them improved properties. Usually, the amount used will be a smaller amount, such as approx. 0.01 to approx. 20, preferably approx. 0.1 to approx. 10% of the total weight of the lubricating mixtures.

The invention also aims at the use of other additives

in combination with the sulphurised mixtures according to the invention. Such additives include e.g. detergents and dispersants of the ash-producing or ash-free type, corrosion and oxidation inhibiting agents, pour point depressants, extreme pressure agents, antiwear agents, color stabilizers and antifoam agents.

The ash-producing detergents are exemplified by oil-soluble, neutral and basic salts of alkali or alkaline earth metals with sulphonic acids, carboxylic acids or organic phosphoric acids which are characterized by at least one direct carbon-phosphorus bond such as those produced by treating an olefin polymer (e.g. polyisobutene with a molecular weight of 1000) with a phosphorizing agent such as phosphorus trichloride, phosphorus heptasulfide, phosphorus pentasulfide, phosphorus trichloride and sulfur, white phosphorus and a sulfur halide, or phosphorus thiochloride. The most frequently used salts of such acids are sodium, potassium, lithium, calcium, magnesium, strontium and barium.

The term "basic salt" is used to denote metal salts

where metal is present in stoichiometrically greater amounts than the organic acid residue. The commonly used methods of preparing the basic salts involve heating a mineral oil solution of an acid with a stoichiometric excess of a metal neutralizing agent, such as the metal oxide, hydroxide, carbonate, bicarbonate or sulfide to a temperature of about 50°C and then to filter the resulting mass. The use of a "promoter" in the neutralization step to support the incorporation of a large excess of metal is likewise known. Examples of compounds useful as promoters include phenolic substances, such as phenol, naphthol, alkylphenol, thiophenol, sulfurized alkylphenol and condensation products of formaldehyde with a phenolic substance; alcohols such as methanol, 2-propanol, octyl alcohol, cellosolve, carbitol, ethylene glycol, stearyl alcohol and cyclohexyl alcohol, and amines such as aniline, phenylenediamine, phenothiazine, phenyl-B-naphthylamine and dodecylamine. A particularly effective method for preparing the basic salts comprises mixing an acid with an excess of a basic alkaline earth neutralizing agent and at least one alcohol promoter, and carbonating the mixture at an elevated temperature, such as 60-200°C.

A- A- '--J rie detergents and dispersants are called this in spite of the fact that, depending on the constitution, the dispersant may on combustion yield a non-volatile material such as boron oxide or phosphorus pentoxide; however, it usually does not contain metal and therefore does not produce metal-containing ash when burned. Many types are known in the art, any of which are suitable for use in the lubricating compositions of the invention. The following are illustrative: (1) reaction products of carboxylic acids (or derivatives thereof) containing at least approx. 34 and preferably at least approx. 54 carbon atoms with nitrogen-containing compounds such as amine, organic hydroxy compounds such as phenols and alcohols, and/or basic inorganic substances. Examples of these "carboxylic dispersants" are described in BG-PS 1,306,529 and in many US-PS including the following: (2) Reaction products of relatively high molecular weight aliphatic and alicyclic halides with amines, preferably polyalkylene polyamines. These can be characterized as "amine dispersants" and examples are described e.g.

in US-PS:

3,275,554, 3,428,757, 3,454,555, 3,565,804.

(3) Reaction products of alkylphenols in which the alkyl group contains at least approx. 30 carbon atoms with aldehydes (esp

formaldehyde) and amines (especially polyalkylene polyamines),

which can be characterized as "Mannich dispersants". The substances described in the following US patents are illustrative:

(4) Products obtained by post-treatment of the carboxylic amine or Mannich dispersants with such agents as urea, thiourea, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, nitriles, epoxides, boron compounds, phosphorus compounds, etc. Examples of substances of this type are described in the following US-PS: (5) Interpolymers of oil-solubilizing monomers such as decyl methacrylate, vinyl decyl ether and high molecular weight olefins, with monomers containing polar substituents, e.g. aminoalkyl acrylates or acrylamides and polyoxyethylene substituted acrylates. These can be characterized as "polymeric dispersants" and examples of these are described in the following US-PS:

Reference should be made to the above-mentioned patents due to the description of ashless dispersants.

Extreme pressure agents and corrosion and oxidation inhibiting agents which can be incorporated into the lubricants according to the invention are exemplified by chlorinated alidate hydrocarbons such as chlorinated wax; organic sulfides and polysulfides such as benzyl disulfide, bis(chlorobenzyl) disulfide, dibutyl tetrasulfide, sulfurized methyl ester of oleic acid, sulfurized alkylphenol, sulfurized dipentene and sulfurized terpene; phosphosulphured hydrocarbons such as the reaction product of a phosphorus sulphide with turpentine or methyl oleate, phosphorous esters including principally dihydrocarbon and trihydrocarbon phosphites such as dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentyl phenyl phosphite, dipentyl phenyl phosphite, tridecyl phosphite, distearyl phosphite, dimethyl naphthyl phosphite, oleyl 4-pentyl phenyl phosphite, polypropylene (mol. wt. 500) substituted phenyl phosphite, diisobutyl substituted phenyl phosphite, metal thiocarbamates such as zinc dioctyl dithiocarbamate and barium heptyl phenyl dithiocarbamate, group II metal phosphorodithioates such as zinc dicyclohexyl phosphorodithioate, zinc dioctyl phosphorodithioate, barium di(heptylphenyl) phosphordithioate, cadmium dionyl phosphordithioate, and zinc salt of a phosphorodithioate prepared by the reaction of phosphorus pentasulphide with an equimolar mixture of isopropyl alcohol and n-hexyl alcohol.

Many of the above-mentioned additional extreme pressure agents and corrosion oxidation inhibitors also serve as antiwear agents. Zinc dialkyl phosphorodithioates are a well-known example.

Pour point depressors are a particularly useful type of additive that is often incorporated into lubricating oils as described here. The use of such pour point depressants in oil based compositions to improve the low temperature properties of oil based compositions is well known in the art, see e.g. page 8 of "Lubricant Additives", by C.V.Smalheer and R.Kennedy Smith (Lezius-Hiles Co. publishers, Cleveland, Ohio, 1967). Examples of useful pour point depressants are polymethacrylates; polyacrylates; polyacrylamides; condensation products of halogenated paraffin waxes and aromatic compounds; vinyl carboxylate polymers; and terpolymers of di-alkyl fumarates, vinyl esters of fatty acids and alkyl vinyl ethers. Pouring point depressors that can be used for the purpose of the invention, their manufacture and use, are described in US-PS 2,387,501, 2,015,748, 2,655,479, 1,815,022, 2,191,498, 2,666,746, 2,721,877, 2,721,878 and 3,250,715 to which reference is made.

Anti-foaming agents are used to reduce or prevent the formation of stable foam. Typical antifoam agents include silicones or organic polymers. Additional anti-foam compositions are described in "Foam Control Agents", by Henry T. Kerner (Noyes Data Corporation, 1976), pages 125-162.

The quantity of oil-soluble sulphurised organic mixture according to the invention is used when used as a concentrate generally in an amount of from 50 to 100% by weight and is often available as a pure mixture.

While the invention is described in detail, it is the attached claims that determine the scope and scope of the invention.

Claims (10)

1. Additive concentrate, characterized by. that they include: a bulk of an oil of lubricant viscosity; and a smaller amount of an oil-soluble sulfurized organic compound that suppressed the emission of volatile sulfur compound, the mixture consisting of an oil-soluble sulfurized organic compound and an oil-soluble hindered organic amine having a structure that provides steric hindrance, the hindered organic amine being selected from among primary amines and secondary amines, wherein the hindered amine is present in an amount of from 0.25 to about 2% by weight, calculated on the weight of the sulphurised organic compound. 2. Additive concentrate according to claim 1, characterized in that the hindered amine is a monoamine with the formula where R', R" and R<1>" can be the same or different and be hydrocarbyl or hydrogen, but collectively have from 2 to about 30 carbon atoms, and give the amine steric hindrance, and where R 2 is hydrocarbyl or hydrogen. 3. Additive concentrate according to claim 2, characterized in that the R'-, R"- and R'" hydrocarbyl group is an alkyl group and R 2 is an alkyl group. 4. Additive concentrate according to claim 2, characterized in that R<1>, R" and R<1>" are an alkyl group which collectively has from approx. 12 to approx. 14 carbon atoms and 2 where R is hydrogen. 5. Lubricating oil mixture, characterized in that it includes: a bulk of an oil of lubricant viscosity; and a minor property-enhancing amount of the additive according to any one of claims 1-5. 6. Additive concentrate according to claim 2, characterized in that the hindered organic amine is soluble in an amount of approx. 5.0 to 10,000 parts by weight per 100 parts by weight oil-soluble sulphurous organic compound. 7. Method for producing an oil additive concentrate, characterized in that it comprises dissolving in a main quantity of an oil of lubricant partial viscosity, a smaller quantity of an oil-soluble sulphurised organic mixture, as this consists of an oil-soluble sulphurised organic compound and an oil-soluble hindered organic amine with a structure that provides steric hindrance whereby the organic amine is selected from among primary and secondary amines, the hindered amine being added to the oil in an amount of 0.25% to approx. 2% by weight, calculated on the weight of the sulphurised organic compound. 8. Method according to claim 7, characterized in that the hindered organic amine is soluble in an amount of approx. 5.0 to 10,000 parts by weight per 100 parts by weight oil-soluble sulphurous organic compound. 9. Procedure for suppressing the emission of volatile sulfur compounds, characterized in that it includes: adding to a major amount of an oil of lubricant viscosity, a portion of an oil-soluble sulfurized organic compound and a minor amount of an oil-soluble hindered organic amine having a structure which provides steric hindrance, the amine being selected from among primary and secondary amines in which hindered amine is added to the oil in an amount of 0.25 to approx. 2% by weight, calculated on the weight of the sulphurised organic compound. 10. Method according to claim 9, characterized in that the hindered amine is a monoamine with the formula: where R<1> , R" and R'" can be the same or different and be hydrocarbyl or hydrogen, but collectively have from 2 to about 30 carbon atoms, and give the amine steric hindrance, where R 2 is hydrocarbyl or hydrogen.