CA1143719A

CA1143719A - Lubricating oil composition containing a metal salt

Info

Publication number: CA1143719A
Application number: CA000337338A
Authority: CA
Inventors: Ronald J. Vaughan
Original assignee: Chevron Research and Technology Co
Current assignee: Chevron USA Inc
Priority date: 1978-12-26
Filing date: 1979-10-10
Publication date: 1983-03-29
Also published as: SE445464B; FR2445369A1; GB2113242A; FR2453890B1; BR7908403A; SE7910374L; NL185356B; NL185356C; SE8502737L; FR2453891B1; DE2950647C2; FR2445369B1; SE8502737D0; FR2453890A1; AU5251179A; AU532696B2; IT7928195A0; DE2950647A1; GB2039291B; FR2453891A1

Abstract

ABSTRACT OF THE DISCLOSURE

A lubricating oil composition having good acid-neutralizing properties and relatively low ash content contains certain dispersant metal carbamates.

Description

1143'71~3 FIELD OF THE INVENTION
This invention relates to lubricting oil compositions containing a metal salt to the metal salts themselves, and to a method for their preparation. More specifically, it relates to a lubricatlng oil composition containing a metal salt of a carbamate.
Engines are now being operated under increasingly severe conditions caused, in part, by the deteriorating quality of fuels. High-sulfur fuels produce large quantitites of acid which must be neutralized by additives in the lubricating oil.
Conventional lubricating oil additives used to neutralize acid are ordinarily metallic salts. These salts, when subjected to high engine-operating temperatures form non-volatile compounds (ash). As increasing amounts of the acid-neutralizing compo-nents are used in oil formulations, the amount of ash formed during engine operation can exceed the amount of ash for which the engine is designed.
One preparation of conventional additives which are overbased to obtain additional acid-neutralizing efficiency is taught in United States 3,126,340. The additive described in this patent is prepared by treating a lubricating oil sulfonate dispersant with an alkaline earth metal oxide and hydroxide and then introducing carbon dioxide and ammonia into the mixture followed by heating the mixture in the presence of water to convert the ammonium carbamate formed from the carbon dioxide and ammonia to an alkaline earth metal carbonate. The alkaline earth metal carbonate is the acid-neutralizing portion of the composition.
United States Patent 3,524,814 teaches the preparation of an overbased alkaline earth metal sulfonate by introducing a mixture of carbon dioxide and ammonia, in an amount sufficient to form a catalytic amount of ammonium carbamate, into a lubri-cating oil having in suspension a neutral alkaline earth metal ~1~3~19 sulfonate containing an alkaline earth oxide. Af~er the cata-lytic amount of ammonium carbamate is preformed, carbon dioxide is continuously introduced into the reaction mixture until sub-stantially all of the alkaline earth oxide is converted to alkaline earth metal carbonate. The metallic carbonate provides the reserve alkalinity in the sulfonate. As a post-treatment step, water is added to the reaction mixture. The addition of water decomposes any ammonium carbamate still present in ~he reaction mixture.
United States Patent 4,034,037 teaches the production of metal carboxylates or N-organic substituted carbamates by reaction of a carboxylic acid or carbon dioxide with an amine in the presence of a soluble metal salt. These salts are dis-closed to be useful as lubricating oil additives.
Katchalski et al, J. Am. Chem Soc. 73, 1829-1831 (1951) describe the preparation of the calcium salt of ethylene dicarbamate.
United States Patents 2,957,826 and 3,056,820 show the use of certain carbamate salts as gelling agents for greases.

2 0 SUMMARY OF THE INVENTION
It has now been found that an overbased dispersant for lubricating oil compositions having a very low ash content as compared to conventional overbased additives can be prepared in a first embodiment of this invention by combining in a solvent at a temperature suitable for reaction to occur the components (a) at least one ashless nitrogen-containing compound selected from ammonia, ammonium salts, and organic compounds containing only carbon, hydrogen, and nitrogen and having at least one -NH group, (b) a basically reacting metallic compound, (c) at least one suspending agent for component (b), and (d)

3'7~.9 a chalcogen compound selected from carbon dioxide, carbon disul-fide, carbon oxysulfide, or sulfur clioxide and mixtures thereof.
To ensure that the composition prepared by this reaction has a relatively low ash content, the ra-tio of the reactants (a), (b), (c), and (d) must be such that from about 1/3 to about 3/4 of the alkalinity value of the final product is derived from the ashless portion of these reactants.

, .

"

- 2a -~371.~

In a second embodiment, it has been folmd that a lubricant, capable of neutralizing acids formed during the operation of an engine, is prepared by dispersing therein a carbamate of the formula ( \ N-C ~ M ~I) .' X
- (H2N-C-Xty M (II) lX
R' ~N-C-X~ Ml/y ~( 2tXI i Z (III) ~: (CR'2)X
(R N-lCI-Xt Ml/y wherein M is an alkali or alkaline earth metal, X is sulfur or oxygen, R is an aliphatic hydrocarbyl group containing 1 to 50 carbon atoms, R' is hydrogen or an aliphatic hydrocarbyl group containing 1 to 50 carbon atoms, x is an integer from 1 to 10, y is 1 or 2 and is equal to the valence of M, and z is zero or an integer between 1 and 10.
The method of dispersing the carbamate is not critical.
It could, for example, be finely ground using a Manton-Gaulin*
Mill, and then be held in fine dispersion using a dispersant.
Or it can be prepared as taught in the first embodiment of this invention. Maintaining a fine dispersion of the carbamate is critical to the effectiveness of the lubricating oil.
DETAILED DESCRIPTION OF T~E INVENTION
_.
The carbamates of this invention can be prepared using conventional techniques that are well known in the art.

*Trade Mark . ~, ~1~3719 It is preferred to prepare them directly in lubricating oil using the novel process descrihed fully herein. The preferred method of preparation comprises combining an amine or ammonia, a dispersant, a group I or group II metal oxide or hydroxide, carbon dioxide or carbon disulfide and a promoter.
DESCRIPTION OF THE FIRST EMBODIMENT
Component (a) -- ashless nitrogen-containing compound The nitrogen portion of component (a) serves as a source of supply of non-ash-forming basic material in the lubri-cating oil additives of this invention. By "ashless" is meant a substance which after combustion has no non-volatile residue.
This ashless nitrogen-containing compound is ammonia, an ammonium salt, such as ammonium bicarbonate, ammonium acetate, or ammonium carbonate and the like, or an organic compound con-taining only carbon, hydrogen, and nitrogen atoms and having at least one -NH group. Mixtures of different nitrogen-containing compounds may also be used. In general, the nitrogen compounds will be selected from the readily available aliphatic amines polyamines, and ammonia.
Ashless nitrogen-containing compounds preferred for use in this reaction are ammonia, ammonium bicarbonate, aliphatic monoamines having up to 50 carbon atoms in the aliphatic portion of the molecule, and aliphatic polyamines such as methylenediamine, polymethylenepolyamines, ethylene-amines and propyleneamines. Aliphatic monoamines include methyl-amine, ethylamine, propylamine, octylamine, dicocoamine, decyl-amine, di(octyl)amine, -tallowamine, eicosylamine, and the like.
The amine may be derived from natural or synthetic sources using methods well known in the art. Preferred monoamines are Cl 20alkylamines and particularly preferred are the Cl 4 alkyl-monoamines, especially methylamine.

~43~1~

The polymethylenepolyamines are prepared from ammonia and formaldehyde and have a general repeating structure H2N(CH2NH)X,H where X' is ]-20. Preferred compounds are those - where x' is 1-6.
The ethyleneamines are those well known amines such as ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, pentaethylenehexamine and the like which are usually prepared by the reaction of an alkylene dichloride and ammonia or from ethyleneimine and ammonia. This reaction yields a complex mixture of alkyleneamines including some cyclic condensation products. The products of this reaction are gen-erally known in the art as ethyleneamines, as described above.
Propyleneamines are a class of polyamines prepared by the reaction of acrylonitrile with an ethyleneamine, such as those described above and having the formula H2N(CH2CH2NH)X,,H
where x" is 1 to 5, followed by hydrogenation of the resultant intermediate. For example, the products prepared from ethylene-diamine and acrylonitrile would be H2N(CH2)3NH(CH2)2NH(CH2)3NH2.
The most preferred amines for use in this invention are methylamine, ammonia and the ethyleneamines. The most preferred amine, from the standpoint of cost, is ammonia. The most preferred amine based on performance is ethylenediamine.
Component_(b) -- metallic compound The basically reacting metallic compound component (b) is any metallic compound which reacts under basic conditions i.e., at a pH greater than 7.0, to form a salt of an organic acid. Typical of such metailic compounds are calcium oxide, hydroxide or methoxide, magnesium oxide, hydroxide or methoxide, barium oxide or hydroxide, aluminium hydroxide, sodium hydroxide, lithium hydroxide, sodium alkoxide, and the like. Useful ` alkoxides are the lower-molecular-weight alkoxides such as methoxide, ethoxide, t-butoxide, and the like. Preferably the ~1~3'~9 oxide or hydroxide of a Group II metal or a Group I metal hydrox-ide is used.
Preferred lubricating oil additives are prepared from magnesium, barium and calcium oxides or hydroxides, although sodium hydroxide is often desirable in certain applications.
Most preferred for use in lubricating oil additives are those compositions prepared from a calcium-containing, basically reacting compound, especially calcium oxide and calcium hydroxide.

- 5a ~

_omponent (c) -- suspending agent The suspending agent, component (c), which must be oil-soluble, is used to keep component (b), the basically reacting metallic component, in solution so that it can be an effective portion of the additive composition. Many of the useful suspending agents also have dispersant activity in the final lubricating oil additive composition. Typical suspending agents include alkali metal or alkaline earth metal hydrocarbyl sulfonates, hydrocarbyl succinimides, hydrocarbyl succinates, hy~rocarbyl succinic anhydrides, alkali metal or alkaline earth metal alkylphenates, alkylphenol-type Mannich bases and alkaline earth metal salts of such Mannich bases. Mixtures of suspending agents are also useful in carrying out the process of this invention.
The alkali metal and alkaline earth metal hydrocarbyl sulfonates useful in the process of this invention are well known in the art. The hydrocarbyl group must have a sufficient number of carbon atoms to render the sulfonate molecule oil soluble. Ordinarily, the hydrocarbyl portion has at least 20 carbon atoms and may be aromatic or aliphatic, but is usually alkylaromatic. Certain sulfonates are typically prepared by sulfonating a petroleum fraction having aromatic groups, usually mono- or dialkylbenzene groups, and then forming the metal salt of the sulfonic acid material. Other feedstocks used for prepar-ing these sulfonates include synthetically alkylated benzenes and aliphatic hydrocarbons prepared by po]ymerizing a mono- or diolefin, for example, a polyisobutenyl group prepared by polymerizing isobutene. The metallic salts are formed directly or by metathesis using well-known procedures.
Succinimide dispersants are also well known in the art, and a general method for their preparation is found in United States Patents 3,219,666, 3,172,892 and 3,272,746. These . .,' ;37~'~

compositions are prepared by reacting an oil-soluble alkyl or alkenyl succinic acid or anhydride with a nitrogen-containing compound. The succinimide may be of the type commonly known as a mono or bis-succinimide. Preferred nitrogen compounds used in making the succinimides are those known as the ethyleneamines, and particularly preferred are triethylenetetraamine and tetra-ethylenepentamine. The preferred alkyl or alkenyl groups contain from 50 to 300 carbon atoms, and the most preferred compositions are prepared from polyisobutylene. When this type of suspending agent is employed, the amine portion will contribute to the alkalinity value.
The oil-soluble alkyl or alkenyl succinic anhydrides used in preparing the succinimides are themselves useful as suspending agents; however, they are most preferred for use as co-suspending agents, particularly in combination with a sulfonate suspending agent. Preferably the alkyl or alkenyl portion contains from 50 to 300 carbon atoms.
The succinate esters are prepared by reacting an alcohol with an alkenyl or alkyl succinic anhydride as described above, using a procedure such as that described in United States Patents 3,381,022 and 3,522,179. Ordinarily the alkyl or alkenyl group contains from 50 to 300 carbon atoms.
Alkali metal and alkaline earth metal phenates are well known in the art and are the alkali metal or alkaline earth metal salt of an oil-soluble alkyl-substituted phenol. The composition may be sulfurized. Typical phenates are prepared by neutralizing a C8_128 alkYlp~lenol with calcium hydroxide or oxide.
Mannich bases are useful suspending agents. Mannich bases are prepared by reac-ting an oil-soluble phenolic or ~14~3~719 aleoholie material, such as alkylphenol, with an aldehyde, such as formaldehyde or acetaldehyde, and a nitrogen-containing eompound. Typieal Mannieh bases eontain from about 8 to 128 or more carbon atoms in the alkyl groupO If desired, the alkaline earth metal salt of the phenolie-type Mannieh base may be used as a suspending agent.

- 7a -, ., ,. .

119,3t7~_~9 Preparation The reaction of this invention is carried out by adding a reactan-t selected from carbon dioxide, carbon disulfide, carbon oxysulfide or sulfur dioxide or mixtures thereof to the reaction mixture of components (a), (b), and (c). While the reactant is ordinarily added in the gaseous form, it may be added in liquid or solid form, for example, as dry ice or liquid sulfur dioxide. Carhon dioxide is the preferred reactant.
The reaction is carried out in a suitable solvent.
Preferably the solvent is a lubricating oil so that no removal of the solvent is necessary before incorporation of the additive into the lubricating oil. Other useful solvents are lower-boiling hydrocarbon solvents such as hexanes or hydrocarbon thinner. Mixtures of lubricating oil with hexanes or hydro-carbon thinner are also very useful. After the preparation is complete, the lower-boiling hydrocarbon solvents are readily removed by heating, if desired Promoter In an preferred embodiment of the invention a promoter is added. It probably functions as a solubilizing agent for the basically reacting metal compound and to keep any water formed during the reaction in solution. The promoter is preferably an alkanol of 1 to 6 carbn atoms or alkanediol of 2 to 6 carbon atoms such as methanol, ethanol, isopropanol, buta-nol, ethylene glycol, 1,4-butanediol and the like. Most pre-ferred is ethanol.
Since the workability of the product is adversely affected by water, the process is preferably carried out under anhydrous conditions. If the basically reacting metal compound is one which generates water as a result of the reaction of this invention, sufficient promoter should be used to keep the water in solution. Water not in solution leads to gel formation 1~3~7~'~

and the irreversible formation of metal carbonate which prevents efficient filtering.
The process of this invention may be carried out at any temperature from the freezing point of the mixture to its ` boiling point. Ordinarily the reaction is conducted at a tem-perature of from 0 to 75C, preferably 20 to 75C and most pre-ferably 25 to 50C. However, when component (a) is ammonia, initial reaction temperatures as low as -10C are used. While the reaction proceeds satisfactorily at atmospheric pressure, higher or lower pressures may be used if desired.
The ratio of the suspending agent to the carbon dioxide and the nitrogen-containing material is such that from about 1/3 to 3/4 of the alkalinity value of the final composi-tion is contributed by the ashless nitrogen-containing material.
Preferably it is desirahle to have about one equivalent of the nitrogen-containing compound for each equivalent of the basic-ally reacting metallic compound. Under typical conditions and based on 1 equivalent of the basically reacting metallic compound, the reaction mixture would con-tain from 0.3 to 2.0, preferably from 0.5 to 1.5, equivalents of the nitrogen compound;
from 1 to 3, preferably 1.5 to 2.5, equivalents of chalcogen compound; and from 2 to 20, preferably 4 to 10, parts by weight of the suspending agent per part of the basically reacting metallic compound. The hydrocarbon solvent should be present in sufficient amount to enable good mixing of the reactants and is usually present as from 5 to 50 and preferably 10 to 25 milli-liters per gram of basically reacting metallic compound. From 0 to 5, preferably 1 to 2, milliliters of the promoter per gram of basically reacting metallic compound is also used.
In a preferred method for carrying out the reaction, a sodium, calcium or magnesium alkylbenzene sulfonate is used as the suspending agent. It is also preferred to use an ~1~37~9 alkenylsuccinimide or an alkenylsuccinic anhydride as a co-solubilizing agent. If this combination of solubilizing agents is used, an increased alkalinity value for the product is ob-tained when, prior to addition of component (a) the nitrogen compound, and the basicallly reacting material component (b), preferably an alkaline earth metal oxide or hydroxide, the mix-ture of components (b) and the solvent is pretreated with a small abmount of component (d) for example with from 1 to 10%, preferably about 5%, of the total amount of component (d).
Preferred carbamates are those wherein M is barium, magnesium, or calcium. Magnesium and calcium are particularly preferred.
Referring to Formulae I, II and III, R is an ali-phatic hydrocarbyl group containing 1-50 carbon atoms. For those groups having at least 3 carbon atoms, the aliphatic portion may be straight or branched-chain and may contain one or more sites of olefinic or acetylenic unsaturation. Preferred are straight or branched-chain alkyl groups of 1-20 carbons, such as methyl, ethyl, propyl, decyl, octyl, or those derived from tallow amine or cocoamine. Most preferred are alkyl of 1 to 4 carbon atoms. R' is hydrogen or an aliphatic hydrocarbyl group as defined for R. R and R' need not be identical hydro-carbyl groups. Also preferred are those carbamates wherein R' is hydrogen. Preferred compositions of Formula III are those derived from ethylene amines and propylene amines, i.e., those for which x is 2 or 3 and z is zero or 1-4. The amines for use in preparing these carbamates are well known.
Typical dispersing agents that may be used to keep the carbamate in solution include alkali metal or alkaline earth metal hydrocarbyl sulfonates, hydrocarbyl succinimides, hydro-carbyl succinates, hydrocarbyl succinic anhydrides, alkali metal or alkaline earth metal alkylphenates, alkylphenol-type 37~

Mannich bases and alkaline earth metal salts of such Mannich bases. Mixtures of suspending agents are also useful in carry-ing out the process of this invention.
If the carbamate is to be prepared in sitll, a mixture is formed of the appropriate amine or ammonia, a dispersant as described above, an alkali metal or alkaline ~arth metal oxide or hydroxide, and a Cl 6 alkanol promoter. Carbon dioxide or carbon disulfide is then added to form the carbamate or thio-carbamate. This process is preferably carried out under an-hydrous conditions. The aliphatic amine-based carbamate, when prepared as above, can be dispersed in a fluid, non-gelled lubricating oil, since the workability of the product is ad-versely affected by water, the process is preferably carried out under anhydrous conditions. If the basically reacting metal compound is one which generates water as a result of the reaction of this invention, sufficient promoter should be used to keep the water in solution. Water not in solution leads to gel formation and the irreversible formation of metal carbon-ate, which prevents efficient filtering.
The compositions preparsd by this invention provide a high alkalinity value at a lower ash content than is present in most conventional dispersants and/or acid-neutralizers used as lubricating oil additives.
Alkalinity value is one method of specifying the degree of overbasing of the lubricating oil composition. It is also a measure of the acid-neutralizing properties of the compo-sition. The method for determining the alkalinity value commonly used for a composition is set forth in ASTM Method D-2896. Briefly, the alkalinity value is the total base number given as milligrams of potassium hydroxide per gram of sample.

It is the quantity of potassium hydroxide required to neutra-lize the same amount of perchloric acid that 1 gram of the '`
sample neutralizes. For example, if a composition has the same acid-neutralizing capacity per gram as 10 mg of potassium hydroxide, the composition is given an alkalinity value of 10.
The lower limit of alkalinity value is 0 for a neutral composi-tion. Values of 200 or more are especially desirable for use in lubricants which are exposed to the decomposition products of sulfur-containing diesel fuels. Typical alkalinity values for additive compositions of this invention range from about 30 to 400 or more.
Lubricant compositions containing the additives of this invention are prepared by admixing through conventional : admixing techniques the appropriate amount of the additive of this invention with a lubricating oil. The selection of a particular base oil depends on the contemplated application of the lubricant and on the presence of other additives. Gener-ally, the amount of the additive of this invention used in the lubricating oil will vary from 0.1 to 40~ by weight, and prefer-ably from 2 to 35~ by weight. The resulting lubricating oil will usually have an alkalinity value in the range of 1 to 120, preferably 2.5 to 100.
The lubricating oil which may be used in this inven-tion include a wide variety of hydrocarbon oils such as naph-thenic bases, paraffin bases and mixed-base oils. The lubri-cating oils may be used individually or in combination and gener-ally have a viscosity which ranges from 50 to 5000 SUS
(Saybolt Universal Seconds) and usually from 100 to 1500 SUS at 38C.
In many instances it may be advantageous to form con-centrates of the additives of this invention within a carrier liquid. These concentrates provide a convenient method of handling and transporting the additives of this invention before their subsequent dilution and use. The concentration of the 3'~19 additives of this invention within the concentrates may vary from 85 to 40% by weight, although it is preferred to maintain the concentration between about 50 and 70% by weight. The preferred method of obtaining concentrates is to carry out the preparation of the additive in a limited amount of the lubri-cating oil -that will be used in making the final dilute lubri-cant composition. Alternatively, the additive may be prepared in a low-boiling hydrocarbon which is removed by distillation after adding a limited amount of lubricating oil.
As desired, other additives may be included in the lubricating oil compositions of this invention. These additives include antioxidants or oxidation inhibitors, dispersants, rust inhibitors, anticorrosive agents, and so forth. Other types of -~ lubricating oil additives which may be employed include anti-foam agents, stabilizers, antistain agents, tackiness agents, antichatter agents, dropping point improvers, antisquawk agents, extreme-pressure agents, odor control agents, and the like.

-12a-~3'71~

EXAMPLES
The following examples are presented to illustrate this invention, and are not in any way to be interpreted as limiting the scope of the invention.
Example 1 To a 5-liter, 3-neck flask was charged 700 g of a 67%
concentrate of a calcium alkylated aromatic sulfonate in hydro-carbon thinner, 350 g of a polyisobutenyl succinimide prepared from polyisobuterlyl succinic anhydride having a number average molecular weight for the polyisobutenyl group of 1050, and tetraethylenepentamine as a 57% concentrate in lubricating oil and containing 2.13% nitrogen, 2100 ml of hydrocarbon thinner and 140 ml of 95% ethanol. The mixture was stirred at room tempera-ture for 10 minutes and then 9 g of carbon dioxide was added over a 35-minute period at a temperature of from 25 to 28C. Then 140 g of ethylenediamine and 180.5 g of calcium hydroxide were added to the mixture. An additional 206 g of carbon dioxide was added over a period of 2 hours, 17 minutes at a temperature of from 25 to 32C. 50 g of diatomaceous earth was added to the mixture, which was then filtered through a pad of diatomaceous earth. The filtrate was stripped at 25 inches Hg vacuum. Then 250 g of neutral lubricating oil was added, and this product was stripped to 105C at 40 mm Hg pressure. The mixture yielded 1441 g of product having an alkalinity value of 329.4, and containing 6.21% calcium and 4~47% nitrogen.
Example 2 To a 5-liter, 3-neck flask was added 440 g of the cal-cium sulfonate described in Example 1, 2000 ml of hydrocarbon thinner and 92 ml of methanol. This mixture was stirred and 73.2 g ethylenediamine and 68.4 g calcium oxide were added. To this mixture was added 101 g of carbon dioxide over a period of 1 hour,

4 minutes at a -temperature of from 35 to 50C. The product was 1~3~1C~

stripped to 115C at atmospheric pressure and 250 ml of hydro-carbon thinner and 40 g of diatomaceous earth were added. The mixture was then filtered through filter aid and -13a-1~4;~719 the filtrate was stripped after addition of 500 g of neutral lubricating oil to 100C at 20 mm of Hg pressure to yield 865 g of product as a 52% concentrate in oil having an alkalinity value of 184.6, containing 3.55% calcium and 2.43% nitrogen.
Example 3 To a l-liter, 3-neck flask was added 110 g of the cal-cium sulfonate described in Example 1, 200 ml of hydrocarbon thinner and 25 ml of methanol. This mixture was stirred and to it was added 18.3 g ethylenediamine and 17.1 g of calcium oxide.
This mixture was heated to 50C and then 26 g of carbon dioxide was introduced over a period of 1 hour. The mixture was stripped to 75C at atmospheric pressure and then 5 ml water was added.
The product set up into a gel. After addition of 15 ml of water, the gel broke. The mixture was heated to 75C and 10 g of diato-maceous earth was added. The mixture was filtered through diato-maceous earth and then stripped to 90C at 20 mm of Hg pressure to yield 63 g of product having an alkalinity value 404.3 and containing 4.76% nitrogen and 28.54, 28.75% sulfated ash.
Example 4 To a 2-liter, 3-neck flask was added 184 g of the cal-cium sulfonate described in Example 1, 420 ml of hydrocarbon thinner and 23 ml of methanol. This mixture was stirred and to it was added 9.3 g of ethylenediamine and 33.9 g of calcium hydroxide. The mixture was heated to 45C and then 29 g of carbon dioxide was added at a temperature of 45-48C. The product was stripped to 132C under atmospheric pressure. The product was then filtered through diatomaceous earth and was stripped to 160C at atmospheric pressure and then to 204C at 20 mm Hg pressure to yield 133 g of product having an alkalinity value of 30 275.1, a sulfated ash of 29.5% and containing 1.7% nitrogen.
Example 5 To a 5-liter, 3-neck flask was added 700 g of the cal-~1~3719 cium sulfonate described in Example 1, 350 g of the succinimide described in Example 1, 2100 ml of hydrocarbon thinner and -14a-~1~3719 140 ml of 95% ethanol. The reaction mixture was stirred at room temperature for 10 minutes and then 6 g of carbon dioxide was added at 25C over a 28-minute period. To the mixture was then added 140 g ethylenediamine and 180.5 g of calcium hydroxide. To this mixture was added 203 g of carbon dioxide over a period of 2 hours, 20 minutes at a temperature of 32C. The product was stripped to 110C and 50 g of diatomaceous earth was added. The product was filtered through diatomaceous earth and then 250 g of 100 neutral lubricating oil was added and the mixture was stripped to 110C at 20 mm Hg pressure to yield 1316 g of product having an alkalinity value of 299.5 and containing 3.7% nitrogen and 6.54% calcium. The alkalinity value as measured by ASTM
Method D-664 was 327.
Example 6 To a 5-liter, 3-neck flask was added 440 g of the cal-cium sulfonate described in Example 1, 2000 ml of hydrocarbon thinner and 150 ml of isopropyl alcohol. This mixture was stirred and to it was added 73.2 g ethylenediamine and 68.4 g of calcium oxide. Then, 99 g of carbon dioxide was introduced at a temperature of from 35 to 47C over a period of 1 hour, 18 minutes. The product was then stripped to 115C (bottoms) and 60 g of diatomaceous earth was added. The mixture was stirred for 20 minutes while cooling and then filtered through diatoma-ceous earth. The filtrate was treated with 40 g diatomaceous earth and filtered again through diatomaceous earth. ~ the filtrate was added 400 g of 100 neutral lubricating oil and the mixture was stripped to 95C at 20 mm Hg pressure to yield 819 g of product as a 49% concentrate in oil and having an alkalinity value of 207, and containing 3.66% calcium and 2.89% nitrogen.
Example 7 To a 5-liter, 3-neck flask was added 560 g of the cal-cium sulfonate descrihed in Fxample 1, 280 g of polyisobutenyl 371C~

succinic anhydride wherein the polyisobutenyl group had a number average molecular weight of 1050, 140 g ethylenediamine and 2100 ml of hydrocarbon thinner. The mixture was stirred -15a-1143~19 for 15 minutes at room temperature and then 140 ml of ethanol and 169 g of calcium hydroxide were added. To this mixture, 188 g of carbon dioxide was introduced at a temperature of fro~ 25 to 38C over a period of 2 hours, 12 minutes. The mixture was then stripped to 150C and 50 g of diatomaceous earth was added. The mixture was cooled with stirring to 40C and then filtered through diatomaceous earth. The product was stripped to 110C at 40 mm Hg pressure to yield 938 g of product having an alkalinity value of 374.3 and containing 4.20% nitrogen and 27.34% sulfated ash.
The alkalinity value by ASTM Method D-664 was 407.
Example 8 To a l-liter, 3-neck flask was added 150 g of the cal--cium sulfonate described in Example 1, 30 g of the succinimide described in Example 1, 350 ml of hydrocarbon thinner, 25 ml of 95% ethanol and 22.6 g of calcium hydroxide. The reaction mixture was cooled to 5C and 20 g of monomethylamine was added. A dry-ice condenser was placed on the reaction flask to avoid loss of methylamine during the addition. The reaction system was sparged with nitrogen before beginning carbonation and then 26 g of carbon dioxide was added at a temperature of 17 to 25C over a period of

5 minutes. The product was centrifuged for hour at 11,000 revolutions per minute. The solids from centrifugation were isolated by washing with mixed hexanes, centrifuging and drying in a vacuum oven. The alkalinity value of the solids was 1008.4.
Example 9 To a l-liter, 3-neck flask was added 90 g of sodium sulfonate prepared by sulfonating 60 weight percent of petroleum fraction and 40 weight percent of a synthetic alkyl-benzene, 300 ml hydrocarbon thinner, 15 ml of 100% ethanol, 9.2 g of 98%
ethylenediamine and 12.0 g of sodium hydroxide. To the reaction mixture was added 13 g of carbon dioxide at a temperature from 1~4371'~

25 to 30C over a period of 1 hour, 6 minutes. The mixture was stripped to 115C (bottoms~, cooled to room temperature and then 15 g of diatomaceous earth -16a-added. The mixture was filtered through diatomaceous earth and the filtrate was then stripped to 110C at 15 mm Hg pressure to yield 82 g of product having an alkalinity value of 30.6 and containing 2.87% sodium and 0.28% nitrogen.
Example 10 To a 5-liter, 3-neck flask was added 880 g of the cal-cium sulfonate described in Example 1, 2000 ml of hydrocarbon thinner, 140 ml of 95~ ethanol, 140 g of 98% ethylenediamine and 118.5 g of aluminum hydroxide. To this mixture was added 101 g of carbon dioxide at a temperature of from 25 to 35C
over a period of 1 hour, 15 minutes after which 84 g of calcium hydroxide was added. The mixture was stripped to 115C and the product centrifuged at 11,000 rpm for 30 minutes. The mixture was filtered through diatomaceous earth and the filtrate stripped to 115C at 20 mm Hg pressure to yield 579 g of product having an alkalinity value of 61.7 and containing 0.0002% aluminum, 0.1361% calcium and 1.88% nitrGgen.
Example 11 To a l-liter, 3-neck flask was added 1918 g sodium bicarbonate, 5 ml water, 20 ml methanol, 10.3 g magnesium oxide, 170 g of the sulfonate described in Example 1, and 400 ml of hydrocarbon thinner. This mixture was stirred and to it was added 15.3 g of ethylenediamine. To this mixture at a tempera-ture of 30-35C was added 23 g carbon dioxide over a period of 3 hours. The mixture was then stripped to 115C (bottoms).
Diatomaceous earth was added to the product which was then filtered, centrifuged for 0.5 hour at 11,000 RPM, and filtered again through diatomaceous earth. The filtrate was stripped to 115-120C at 4 mm Hg pressure to yield 159 g of product having an alkalinity value of 208.
Example 12 ~o a 2-liter, 3-neck flask was added 120 g of the cal-i 1~3719 cium sulfonate described in Example 1, 600 ml of hydrocarbonthinner, 50 ml of ethanol, 80 g of the succinimide described in Example 1 and 22.6 g of calcium hydrcxide. The reaction mixture was cooled to -5C. Ammonia gas was introduced at a -17a-~1~371~

rate of 500 ml per minute for a period of 43 minutes. During the last 28 minutes of ammonia introduction, 28 g of carbon dioxide was simultaneously introduced. During the addition of the ammonia and the carbon dioxide, the temperature of the reaction mixture rose from -5C to 26C. The reaction mixture was then stripped to 115C (bottoms) at atmospheric pressure, cooled to 25C and then 25 g of diatomaceous earth was added.
The product was filtered through diatomaceous ear-th and the fil-trate was stripped to 110C at 20 mm ~Ig pressure to yield 116 g of product having a alkalinity value of 144.8 and containing 4.82% calcium and 1.00% nitrogen.
Example 13 A 3-liter, 3-neck flask was charged with 250 g of the calcium sulfonate used described in Example 1 and 600 ml of hydrocarbon thinner. This mixture was stirred while 50 ml li~uid ammonia and 38 g carbon dioxide were introduced at room temperature. The reaction mixture was maintained at 25C
throughout the reaction. To this mixture was added 40 ml methanol and 25.2 g calcium oxide. This mixture was stirred at room temperature, then heated to 45C and 100 ml methanol was added. The product was stripped to 130 (bottoms), centrifuged for 30 minutes at 11,000 rpm and then stripped to 95C at 20 mm Hg pressure to yield 147 g of product having an alkalinity value of 53.3 and containing 9.74% sulfated ash and 0.43%
nitrogen.
Example 14 To a 2-liter 3-neck flask was added 160 g of the calcium sulfonate described in Example 1 and 420 ml of hydro-carbon thinner. This mixture was stirred while 17 ml liquid ammonia and 28 g carbon dioxide were introduced at room tempera-ture. The reaction mixture was maintained at 25C throughout the reaction. To this mixture was added 40 ml methanol and ~: 1143~719 ':
25.2 g calcium oxide. The mixture was stirred at room tempera-ture, then heated to 45C and 100 ml methanol was added. The product was stripped to 130C (bot~oms), centrifuged for 30 minutes at 11,000 RPM and then stripped to 95C at 20 mm Hg -18a-~143719 pressure to yield 147 g of product having an alkalinity value of 185.3 and containing 6.9% calcium and 0.73% nitrogen.
Example 15 To a l~ ter 3-neck flask was added 120 g of the calcium sulfonate described in Example 1, 200 ml hexane and 25 ml methanol. The mixture was stirred and then 18.3 g ethyl-enediamine and 12.3 g magnesium oxide were added. The mixture was heated under reflux for 1 hour at 56-58C. Carbon dioxide was added at a flow rate of 100 ml/min and at a temperature of 53C over a period of 1 hour. The mixture was heated to reflux for 1/2 hour and then stripped to 75C at atmospheric pressure.
5 g of diatomaceous earth was added while cooling to 40C, the mixture was filtered through diatomaceous earth and then stripped -to 75C at 20 mm Hg pressure to yield 37 g of product having a alkalinity value of 101.6 and containing 0.0629%
magnesium, 0.4050% calcium and 3.14% nitrogen.
Example 16 To a l-liter, 3-neck flask was added 90 g of sodium sulfonate as used in Example 9, 300 ml hydrocarbon thinner, 15 ml 100% ethanol, 9.2 g ethylenediamine, and 16.2 g sodium methoxide. Then, 8 g of carbon dioxide was added at a tempera~
ture of 30C over a period of 1 hour, 8 minutes. The mixture was stripped to 150C (bottoms); then it was cooled to 40C and 10 diatomaceous earth was added. The mixture was centrifuged at 11,000 RPM for 30 minutes and then filtered through diatoma-ceous earth. The filtrate was stripped to 115C;at 20 mm Hg pressure to yield 73 g of product having an alkalinity value of 153.3 and containing 6.6% so~ium and 1.05% nitrogen.
Example 17 ; 30 To a l-liter, 3-neck flask were added 90 g of sodium sulfonate as described in Example 9, 300 ml hydrocarbon thinner, 15 ml 100~ ethanol, 9.2 g ethylenediamine and 12.0 g sodium ; ~ i 11~3719 : hydroxide. Then, 13 g of carbon dioxide were added over a period of 1 hour, 44 minutes at a temperature of from 25-30C.
The mixture was stripped to 115C (bottoms), cooled to room temperature and then 15 g of diatomaceous earth was -19a-1~3~19 added. The mixture was filtered through diatomaceous earth and then the filtrate was stripped to 110C at 15 mm Hg to yield 82 g of product having an alkalinity value of 30.6 and containing 0.28% nitrogen.
Example 18 To a 5-liter, 3-neck flask was added 880 g of the calcium sulfonate described in Example 1, 280 g of the succin-imide described in Example 1, 2100 ml hydrocarbon thinner and 140 ml ethanol. To this mixture was added 6 g of sulfur dioxide at room temperature over a period of 45 minutes. 140 g ethylenediamine and 180.5 g calcium hydroxide were added to the mixture, then 194 g carbon dioxide and 21 g of sulfur dioxide were added over a period of 2 hours, 20 minutes. The reaction mixture was then stripped to 110C (bottoms), centrifuged at 11,000 RPM for 1/2 hour and then filtered through diatomaceous earth and stripped to 110C at 20 mm Hg pressure. Then, 150 g of 100 neutral lubricating oil was added to yield 1035 g of product having an alkalinity value of 234.3 and containing 1.26~ sulfur, 2.78, 2.75% nitrogen, and 5.17% calcium.
Example 19 To a 5-liter 3-neck flask was added 880 g of the calcium sulfonate described in Example 1, 280 g of succinimide described in Example 1, 2100 ml of hydrocarbon thinner and 140 ml of 95% ethanol. Over a period of 35 minutes, 3 g of sulfur dioxide and 4 g of carbon dioxide were added to the mixture. ~hen 140 g ethylenediamine and 180.5 g calcium hydroxide were added and 186 g of carbon dioxide and 35 g of sulfur dioxide were added over a period of 2 hours, 50 minutes at a temperature from 30-42C. The reaction mixture was stripped to 115C (bott~oms), centrifuged at 11,000 RPM for 30 minutes and then filtered through diatomaceous earth. The filtrate was stripped to 115C at 20 mm Hg pressure and 150 g ~14~

of 100 neutral lubricating oil was added. The final product weighed 1288 g, had an alkalinity value of 318.3 and contained 2.10% sulfur, 6.81% calcium, and 3.75% nitrogen. The alkalin-ity value based OII the ASTM D-664 titration was 342.

-2Oa-Example 20 To a 5-liter, 3-neck flask was added 560 g of the calcium sulfonate described in Example 1, 280 g of the succinic anhydride described in Example 7, 140 g ethylenediamine and 2100 ml of hydrocarbon thinner. The mixture stood for 15 minutes at room temperature after which 140 ml 95% ethanol and 169 g calcium hydroxide were added. Then, 183 g of carbon dioxide and 10 ml of carbon disulfide were added over a period of 2 hours, 25 minutes at a temperature of from 30-35C. The product was stripped to 115C, filtered through diatomaceous earth and then stripped to 110C at 40 mm Hg pressure to yield a product having an alkalinity value of 352.6 and containing 4.41% nitrogen, 7.72% calcium and 1.53% sulfur.
Example 21 To a 5-liter, 3-neck flask was added 600 g of the suc-cinimide described in Example 1, 2500 ml hydrocarbon thinner and 150 ml 95% ethanol. The mixture was stirred and 110 g ethylenediamine and 158 g calcium hydroxide were added. 175 g of carbon dioxide was added over a period of 2 hours, 9 minutes at a temperature of from 30-38C. The mixture was stripped to 110C (bottoms), centrifuged at 11,000 RPM for 30 minutes and then filtered through diatomaceous earth. The filtrate was treated with 50 g of diatomaceous earth and stripped to 105C
at 20 mm Hg pressure to yield 647 g of product having an alka-linity value of 385.3 and containing 5.58% nitrogen and 23.19%
sulfated ash.
Example 22 To a 2-l:Lter, 3-neck flask was added 200 g of the succinic anhydride described in Example 9, dissolved in 1000 ml of hydrocarbon thinner and 43.6 g of ethylenediamine. The mixture was heated to 100C and then cooled to room temperature and 48.5 g of calcium hydroxide and 50 ml of 95% ethanol were 437~9 added. Then, 40 g of carbon dioxide was added over a period of 41 minutes at a temperature of from 30 to 45C. The mixture was then stripped to 115C (bottoms) and filtered through diato-maceous earth. The filtrate was stripped to 105C at 20 mm Hg -21a-~:~43719 pressure to yield 214 g of product having an alkalinity value of 344.1 and containing 4.85% nitrogen and 6.76% calcium.
Example 23 To a 2-liter, 3-neck flask was added 36 g of the succinic anhydride described in Example 9, 18.4 g ethylenedi-amlne and 500 ml hydrocarbon thinner. This mixture was heated to 50C for 1/2 hour. It was then cooled to room temperature and 110 g of the calcium sulfonate described in Example 1 were added along with 25 ml of ethanol and 22.2 g of calcium hydroxide. The mixture was stirred and then 45 g sulfur dioxide was added. An additional 200 ml of hydrocarbon thinner was added and the product was then stripped to 120C (bottoms). The product was centrifuged and a portion of the precipitate was taken up in hexanes and allowed to stand. This portion was then centrifuged at 18,000 rpm for 30 minutes. The product was dried in a vacuum desiccator. Upon analysis it contained 8.4~% N and 37.0% sulfated ash.
Example 24 To a 2~1iter, 3-neck flask was added 250 g of the succinimide described in Example 1 and 1000 ml of hydrocarbon thinner. This mixture was stirred and then 50 ml of ethanol, 45.2 g of calcium hydroxide and 37 g ethylenediamine were added. This mixture was stirred at room temperature and then 50 g of carbon dioxide was added over a period of 1.2 hours.
An additional 6 g of calcium hydroxide was added and another 3 g of carbon dioxide was introduced. The temperature of the reaction mixture rose to 42C during the addition of the carbon dioxide. The mixture was stripped to 115C (bottoms). The product was centrifuged at 11,000 RPM for 1/2 hour, then filtered twice through diatomaceous earth and stripped at 105C

~--, - 22 ~ .~'. J

~3719 (bottoms) at 20 mm Hg pressure to yield 299 g of product having an alkalinity value of 297.1 and containing 5.22% calcium and 4.69, 4.73~ nitrogen.
Example 25 The compositions of the Examples noted in Table I
were tested in a Caterpillar* l-G-2 test in which a single-*Trade Mark - 22a -/ ,, ` ~14371~3 cylinder diesel engine having a 5-1/8" bore by 6-1/2" stroke is operated under the following conditions: timing, degrees BTDC, 8; brake mean effective pressure, psi 141; brake horsepower 42;
Btu's per minute 5850; speed 1800 RPM; air boost, 53" Hg absolute; air temperature in, 225 F; water temperature out, 190F; and sulfur in fuel 0.4%w. At the end of each 12 hours of operation, sufficient oil is drained from the crankcase to allow addition O F 1 quart of new oil. In the test on the lubri-cating oil compositions of this invention, the l-G test is run 10 for 60 hours. At the end of the 60-hour period, the engine is dismantled and rated for cleanliness using the Institute of Petroleum Test Number 247/69 merit rating system for engine wear and cleanliness, accepted by ASTM, API and ~AE as a rating system for engines. The over-all cleanliness of the engine is noted as WTD, which is the summation of the above numbers.
Lower values represent cleaner engines.
The base oil used in these tests is a Citcon 350 neutral oil containing the noted amount of additive. Each oil was formulated to have an alkalinity value of 10.

`:

r~ N 1--r~ ~ ~
E-~ --~ ~D C~
_ ~ ~

~, C~ ;~;XI
c a C

. ~9 ~ ~
N N N
:~
~r ~ ~ ~ n n ¢ C
E~ ~ G~
,~, ~

n o o o ~ N
V C~
--I
I I
~n n ~
U~ .C~ -a~a~ ~ o ~ ~ ~ C~
O ~ l l O o o CO
o o C~
n 'n ~
~ ~ o a ~1 ~' r~ ~
N

~) O ~ ~:~:~
O ~ O O ~ O ~

2~

Claims

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

1. A process for the preparation of a lubricating oil additive composition which comprises combining in a solvent at a temperature suitable for reaction to occur:
(a) at least one ashless nitrogen-containing compound selected from the class consisting of ammonia, ammonium salts, and organic compounds containing only carbon, hydrogen, and nitrogen and having at least one -NH group, (b) a basically reacting metallic compound, (c) at least one suspending agent for component (b), and (d) a chalcogen compound selected from carbon dioxide, carbon disulfide, carbon oxysulfide and sulfur dioxide, and mixtures thereof, the ratio of the reactants (a), (b), (c) and (d) being such that from about 1/3 to about 3/4 of the alkalinity value of the additive composition is derived from the ashless portion of said composition.

2. The process according to Claim 1 wherein component (a) is an aliphatic amine, an aliphatic polyamine, ammonia, or ammonium bicarbonate, and component (c) is an alkali metal or alkaline earth metal hydrocarbylsulfonate, a hydrocarbylsuccin-imide, a hydrocarbylsuccinate, a hydrocarbylsuccinic anhydride, an alkali metal or alkaline earth metal alkylphenate, a Mannich base or an alkaline earth metal salt of a Mannich base, or mixtures thereof.

3. The process according to Claim 2 wherein component (b) is a Group I metal hydroxide or Group II metal oxide or hydroxide.

4. The process according to Claim 3 wherein component (c) is an alkali metal or alkaline earth metal hydrocarbyl-sulfonate, a hydrocarbylsuccinimide or a hydrocarbylsuccinic anhydride, or mixtures thereof.

5. The process according to claim 4 wherein component (a) is ammonia, a C1-50 aliphatic monoamine, methylenediamine, polymethylenepolyamine, an ethyleneamine or a propyleneamine, component (d) is carbon dioxide, and the reaction is carried out in the presence of a promoter which keeps any water present in solution.

6. The process according to claim 5 wherein component (b) is an oxide or hydroxide of barium, calcium or magnesium and said promoter is a C1-6 alkanol or a C2-6 alkanediol.

7. The process according to claim 6 wherein component (c) is an alkali metal or alkaline earth metal hydrocarbylsulfonate in combination with an alkyl or alkenyl succinimide or an alkyl or alkenyl succinic anhydride, each of said alkyl or alkenyl groups containing from 50 to 300 carbon atoms.

8. The process according to claim 7 wherein component (b) is calcium oxide or calcium hydroxide and said promoter is ethanol.

9. The process according to claim 8 wherein component (a) is ammonia, methylamine or ethylenediamine.

10. The process according to claim 7 wherein component (c) and said promoter are combined with a portion of the carbon dioxide prior to the addition of components (a) and (b) and the remainder of the carbon dioxide.

11. The product prepared by the process of claims 1, 2 or 3.

12. The product prepared by the process of claim 10.

13. A lubricating oil composition comprising an oil of lubricating viscosity and from 0.1 to 40% by weight of a product prepared by the process of claims 1, 2 or 3.

14. A lubricating oil composition comprising an oil of lubricating viscosity and from 0.1 to 40% by weight of a product according to claim 12.

15. A lubricating oil concentrate which comprises from 10 to 60% by weight of an oil of lubricating viscosity and from 90 to 40% by weight of a product according to claim 11.

16. A lubricating oil concentrate which comprises from 10 to 60% by weight of an oil of lubricating viscosity and from 90 to 40% by weight of a product prepared by the process of claims 1, 2 or 3.

17. A fluid lubricating oil composition comprising oil of lubricating viscosity having dispersed therein from 0.1 to 40%
by weight of a carbamate of the formula (I) wherein M is an alkali metal or alkaline earth metal, X is sulfur or oxygen, R is an aliphatic hydrocarbyl group containing 1 to 50 carbon atoms, R' is hydrogen or an aliphatic hydrocarbyl group containing 1-50 carbon atoms, and y is 1 or 2 and is equal to the valence of M, together with a dispersant selected from the group consisting of an alkali metal or alkaline earth metal hydrocarbylsulfonate, a hydrocarbylsuccinimide, a hydrocarbyl-succinate, a hydrocarbylsuccinic anhydride, an alkali metal or alkali earth metal alkylphenate, a Mannich base or an alkaline earth metal salt of a Mannich base, or mixtures thereof.

18. The composition of claim 17 wherein M is barium, magnesium or calcium, x is oxygen, R contains 1-20 carbon atoms, and R1 is hydrogen.

19. The composition of claim 17 wherein M is magnesium or calcium, R is alkyl of 1-4 carbon atoms, and the dispersant is an alkali metal or alkaline earth metal hydrocarbylsulfonate, a hydrocarbylsuccinimide or a hydrocarbylsuccinic anhydride, or mixtures thereof.

20. A lubricating oil composition comprising an oil of lubricating viscosity having dispersed therein from 0.1 to 40% by weight of a carbamate selected from the group consisting of (II) and (III) wherein M is an alkali or alkaline earth metal, X is oxygen or sulfur, R' is hydrogen or an aliphatic hydrocarbyl group of 1 to 50 carbon atoms, x is an integer from l to 10, y is 1 or 2 and is equal to the valence of M, and z is zero or an integer from 1 and 10, together with a dispersant selected from the group consisting of an alkali metal or alkaline earth metal hydrocarbyl-sulfonate, a hydrocarbylsuccinimide, a hydrocarbylsuccinate, a hydrocarbyl-succinic anhydride, an alkali metal or alkaline earth metal alkylphenate, a Mannich base or an alkaline earth metal salt of a Mannich base, or mixtures thereof.

21. The composition of claim 20 wherein M is barium, magnesium or calcium, X is oxygen, R' is hydrogen, x is 2-3, and z is zero or 1-4.

22. The composition of claim 21 wherein the carbamate is of formula II.

23. The composition of claim 21 wherein the carbamate is of formula III.

24. The composition of claim 23 wherein M is magnesium or calcium and the dispersant is an alkali metal or alkaline earth metal hydrocarbylsulfonate, a hydrocarbylsuccinimide or a hydrocarbylsuccinic anhydride, or mixtures thereof.

25. The composition of claim 24 wherein z is zero, 1, 2, or 3 and x is 2.

26. A lubricating oil concentrate composition comprising an oil of lubricating viscosity having dispersed therein from 40 to 85% by weight of a carbamate selected from those of the formula (I) (II) (III) wherein M is an alkali or alkaline earth metal, X is sulfur or oxygen, R is an aliphatic hydrocarbyl group containing 1 to 50 carbon atoms, R' is hydrogen or an aliphatic hydrocarbyl group containing 1 to 50 carbon atoms, x is an integer from 1 to 10, y is 1 or 2 and is equal to the valence of M, and z is zero or an integer between 1 and 10 together with a dispersant selected from the group consisting of an alkali metal or alkaline earth metal hydrocarbyl-sulfonale, a hydrocarbylsuccinimide, a hydrocarbylsuccinate, a hydrocarbyl-succinic anhydride, an alkali metal or alkaline earth metal alkylphenate, a Mannich base or an alkaline earth metal salt of a Mannich base, or mixtures thereof.

27. The composition of claim 26 containing a carbamate of Formula I
wherein M is barium, magnesium, or calcium, X is oxygen, R contains 1-20 carbon atoms, and R1 is hydrogen.

28. The composition of claim 27 wherein M is magnesium or calcium, R is alkyl of 1-4 carbon atoms, and the dispersant is an alkali metal or alkaline earth metal hydrocarbylsulfonate, a hydrocarbylsuccinimide, or a hydrocarbylsuccinic anhydride, or mixtures thereof.

29. The composition of claim 26 containing a carbamate of Formula II wherein M is barium, calcium, or magnesium.

30. The composition of claim 29 wherein M is magnesium or calcium and the dispersant is an alkali metal or alkaline earth metal hydrocarbylsulfonate, a hydrocarbylsuccinimide, or a hydrocarbylsuccinic anhydride, or mixtures thereof.

31. The composition of claim 26 containing a carbamate of Formula III wherein M is barium, magnesium, or calcium, X is oxygen, R' is hydrogen, x is 2-3, and z is zero or 1-4.

32. The process according to claim 8 wherein component (c) and said promoter are combined with a portion of the carbon dioxide prior to the addition of components (a) and (b) and the remainder of the carbon dioxide.

33. The process according to claim 9 wherein component (c) and said promoter are combined with a portion of the carbon dioxide prior to the addition of components (a) and (b) and the remainder of the carbon dioxide.

34. The product prepared by the process of claims 32 or 33.