NL8003284A - Molybdenum compounds, processes for their preparation and lubricating oil compositions containing these compounds. - Google Patents

Description

ι 1 1 Ν.Ο. 29,127

Molybdenum compounds, processes for their preparation as well as lubricating oil preparations. containing these compounds.

The present invention relates to new lubricating oil preparations. More particularly, the invention relates to new lubricating oil compositions containing antioxidant molybdenum compounds.

Molybdenum disulfide has long been known as a desirable additive to lubricating oil formulations. However, one of the main drawbacks is its lack of oil solubility. Molybdenum disulfide is usually finely ground and then dispersed in the lubricating oil formulation to impart friction-modifying and anti-wear properties. Pain-milled molybdenum disulfide is not an effective oxidation inhibitor in lubricating oils.

As an alternative to the fine grinding of the molybdenum disulfide, a number of different approaches involving the preparation of salts of molybdenum compounds have been attempted. One type of compound prepared is molybdenum dithiocarbamates. Representative formulations are disclosed in U.S. Pat. described.

Another approach is the formation of dithiophosphates instead of dithiocarbamates. Representative to this type of molybdenum compound are the compositions described in U.S. Pat. No. 3,4-94,866, such as oxymolybdenum diisopropylphosphorodithioate.

In U.S. Pat. No. 3,184-4-10, certain dithiomolybdenylacetylacetonates are described for use in lubricating oils.

Braithwaite and Greene in Wear, 46 (1978), 405-432 describe various molybdenum-containing preparations for use in engine oils.

U.S. Patent 3,34-9,108 discloses a molybdenum trioxide complex with diethylene triamine for use as an additive to molten steel.

Russian Patent 533,625 discloses lubricating oil additives prepared from ammonium molybdate and alkenylated polyamines.

Another way of incorporating molybdenum compounds in oil is to prepare a colloidal complex of molybdenum disulfide or oxysulfides dispersed using known dispersants. US Patent 3 * 225,625 discloses a process involving acidic water containing solution of certain molybdenum compounds is prepared and then extracted with a hydrocarbon ether dispersion with an oil-soluble dispersant and then freed from the ether. US patent 3 * 281 * 355 describes the preparation of a dispersion of molybdenum disulfide by preparing a mixture of lubricating oil, dispersant and a molybdenum compound in water or in an aliphatic alcohol of 1 to 4 carbon atoms with a sulfide ion developing compound and then removing the solvent. Dispersants which are effective in this process include petroleum sulfonates, phenates, alkyl phenate sulfides, phosphorus sulfur olefins, and combinations thereof.

It has been found that a lubricating oil additive can be prepared by combining an ammonium tetrathiomolybdate and a basic nitrogen-containing preparation, preferably in the presence of a polar promoter to form a molybdenum and sulfur-containing complex.

Lubricating oil compositions containing the additive prepared as described herein are effective as liquid and lubricating compositions (depending on the specific additive or additives used) to inhibit oxidation, impart anti-wear and EP properties, and / or modifying the frictional properties of the oil which, when used as a crankcase lubricant, lead to improved mileage.

The exact molecular formula of the molybdenum preparations of the present invention is not known with certainty; however, they are believed to be compounds 40 in which molybdenum, the valences of which are occupied 800 32 84 3 with oxygen or sulfur atoms, has been complexed by either the salt of one or more nitrogen atoms of the basic nitrogen-containing preparation used for the preparation of these preparations.

The molybdenum compound used for the preparation of the complexes of the present invention is ammonium tetrathiomolybdate, ^ 1 Mo MoS ^.

The polar promoter, which is preferably used in the method of the present invention, is a compound which facilitates the interaction between the ammonium tetrathiomolybdate and the basic nitrogen compound. A wide variety of such promoters are known to the person skilled in the art. Common promoters are 1,3-propanediol, 1,4-butanediol, diethylene glycol, butyl-15 cellosolve, propylene glycol, 1,4-butylene glycol, methylcarbiol, ethanolamine, diethanolamine,--methyl diethanolamine, dimethylformamide, N-methyl acetamide, dimethyl acetamide, methanol, ethylene glycol hexamethylphosphoramide ,. tetrahydrofuran and water. Preferred are water and ethylene glycol. Especially preferred is water.

While usually the polar promoter is separately added to the reaction mixture, it may also be present, especially in the case of water, as a component of non-anhydrous starting materials or as hydrate water in the acid molybdenum compound. Water can also be added as ammonium hydroxide.

The basic nitrogen compound should have a basic nitrogen content, as measured according to ASTM D-664 or 30 D-2896. The compound is preferably oil-soluble. Common formulations are succinimides, carboxylic acid amides, hydrocarbon monoamines, hydrocarbon polyamines, Mannich bases, phosphonamides, thiophosphonamides, phosphoramides, the viscosity index of a dispersant improvers, and mixtures thereof. These basic nitrogen-containing compounds are described below (with the caveat in mind that each must contain at least one basic nitrogen atom). Any of the nitrogen-containing compositions may be post-treated with, for example, boron, using art-known methods, 800 3284 as long as the compositions continue to contain basic nitrogen.

These after-treatments are particularly applicable to succinimides and Mannich base preparations.

The monogenic polysuccinimides which can be used for the preparation of the lubricating oil additives as described herein have been described in numerous places and are known in the art. Certain basic types of succinimides and related products, which are encompassed by the term "succinimide" are described in U.S. Pat. Nos. 3 * 219,666, 3,172,892 and 3 * 272.74-6. The term "succinimide" is understood to include many of the amide, imide, and amidine species also formed by this reaction. However, the predominant product is a succinimide and this term is generally accepted as meaning of the reaction product of an alkenyl-substituted succinic acid or anhydride with a nitrogen-containing compound Succinimides, which are preferred because of their commercial availability, are the succinimides prepared from a hydrocarbon succinic anhydride, wherein the hydrocarbon group is from about 24 to about 350 carbon atoms, and an ethylene amine, which ethylene amines are particularly characterized by ethylene diamine, diethylene triamine, triethylene tetramine and tetraethylene pentamine. Especially preferred are the succinimides prepared from polyisobutenyl succinic anhydride having 70 to 128 carbon atoms and tetraethylene pentamine or triethylene tetramine or mixtures thereof.

Also included by the term succinimide are the co-oligomers of a hydrocarbon succinic acid or anhydride and a poly-secondary amine containing at least one tertiary amino nitrogen having almost two or more secondary amino groups. Usually this preparation has an average molecular weight between 1500 and 50,000. A conventional compound will have been prepared by reacting polyisobutenyl succinic anhydride and ethylene dipiperazine. Preparations of this type are described in U.S. Patent Application No. 816,063, July 15, 1977 *

Carboxylic amide preparations are also suitable starting materials for the preparation of the products of the present invention. Compounds of this type are described in 8003284 <φ 5 described in U.S. Patent 3,405,064. These preparations are usually prepared by reacting a carboxylic acid or anhydride or ester with at least 12 to about 350 aliphatic carbon atoms in the aliphatic main chain and optionally with sufficient pendant aliphatic groups to make the molecule soluble in oil, with an amine or a hydrocarbon polyamine, such as an ethylene amine, to give a mono- or polycarboxylic acid amide.

Another group of compounds useful in the present invention are hydrocarbon monoamines, hydrocarbon polyamines, preferably of the type described in U.S. Pat. No. 3,574,576. The hydrocarbon radical, which is preferably alkyl or olefinic with one or two unsaturation sites, usually contains from 9 to 550, preferably 20 to 200, carbon atoms. Particularly preferred amines are the amines derived, for example, from the conversion of polyisobutyl chloride and diethylene triamine to polyalkylene polyamines such as ethylene diamine, diethylene triamine, tetraethylene pentamine and the like, or 2-aminoethylpiperazine, 1.3- propylenediamine, 1,2-propylenediamine and the like.

Another group of compounds suitable for providing basic nitrogen are the Mannich base preparations. These preparations are prepared from a phenol or an alkyl phenol of 9 to 200 carbon atoms, an aldehyde, such as formaldehyde or formaldehyde precursor, such as paraformaldehyde, and an amine compound. The amine can be a mono- or polyamine and conventional preparations are prepared from an alkylamine, such as methylamine or an ethylene amine, such as diethylene triamine or tetraethylene pentamine and the like. The phenolic product can be sulfurized or non-sulfurized. Conventional Mannich bases which can be used in the present invention are described in U.S. Patent Application No. 838,197, September 30, 1977, and U.S. Pat. Nos. 3,649,229, 3 * 368,972, and 3,539,663 * The latter application describes Mannich bases prepared by reacting an alkyl phenol of at least 50 carbon atoms, preferably 50 to 200 carbon atoms, with formaldehyde and an alkylene polyamine HH (AH10 H, wherein A 40 represents a saturated divalent alkyl hydrocarbon group with onn7 9 2 to 6 carbon atoms and η 1 to 10 and wherein the condensation product of the alkylene polyamine can be further reacted with urea or thiourea The use of these Mannich bases as starting materials for the preparation of lubricating oil additives can often be significantly improved by treating the Mannich base using conventional techniques to boron in to include the preparation.

Another preparation group suitable for preparing the additives of the present invention are the phosphoramides and phosphonamides as described in US Pat. Nos. 3 * 909,430 and 3 * 968,157 *. These preparations can be prepared by forming a phosphorus connection with at least one PN bond. For example, they can be prepared by reacting phosphorus oxychloride with a hydrocarbon diol in the presence of a monoamine or by reacting phosphorus oxychloride with a differential secondary amine and a monofunctional amine. Thio-phosphoramides can be prepared by reacting an unsaturated hydrocarbon compound containing 2 to 450 or more carbon atoms, such as polyethylene, polyisobutylene, polypropylene, ethylene, 1-hexene, 1,3-hexadiene, isobutylene, 4- methylpentene-1 and the like, with phosphorus pentasulfide and a nitrogen-containing compound as defined above, in particular an alkyl amine, alkyl diamine, alkylplyamine or an alkylene amine, such as ethylenediamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine and the like.

Another group of nitrogen-containing preparations suitable for the preparation of the molybdenum preparations of the present invention comprises the so-called viscosity index improvers with dispersing action (71 improvers). These 71 improvers are usually prepared by functionalizing a hydrocarbon polymer, in particular a polymer derived from ethylene and / or propylene, optionally containing additional units from one or more comonomers such as alicyclic or aliphatic olefins or dialkenes. The functionalization can be carried out by various methods, which enter a reactive site or reactive sites, which usually have at least one oxygen atom on the polymer. The polymer is then contacted with a nitrogen-containing source to introduce nitrogen-containing functional groups to the polymer-backbone. Nitrogen sources commonly used include basic nitrogen compounds, in particular the nitrogen-containing compounds and preparations described herein. Preferred nitrogen sources are alkylene amines, alkylamines and Mannich bases.

Preferred basic nitrogen compounds for use in the present invention are sucinimides, carboxylic acid amides and Mannich bases.

The compositions of the present invention can be prepared by reacting the ammonium tetrathiomolybate with a basic nitrogen-containing compound, preferably in the presence of a polar promoter, optionally in the presence of an inert diluent.

In the reaction mixture, the ratio of molybdenum compound to basic nitrogen compound is not critical; however, as the amount of molybdenum with respect to basic nitrogen increases, filtration of the product becomes more difficult. Since the molybdenum component is likely to oligomerize, it is expedient to add as much molybdenum as can be easily maintained in the composition. Usually, the reaction mixture will contain 0.01 to 2.00 molybdenum atoms per basic nitrogen atom. Preferably 0.4 to 1.0 and most preferably 0.4 to 0.7 molybdenum atom per basic nitrogen atom is added to the reaction mixture.

The polar promoter, which is optionally and preferably used, is usually present in a ratio of 0.1 to 50 moles of promoter per mole of molybdenum. Preferably 0.5 to 25 and most preferably 1.0 to 15 moles of promoter per mole of molybdenum is present.

This reaction is preferably carried out at a temperature slightly above the temperature, the reaction mixture solidifying to the reflux temperature. The reaction is usually carried out at atmospheric pressure; however, higher or lower pressures may be used if desired using

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methods known to the person skilled in the art. A diluent that does not react with the ammonium tetrathio molybdate is desirable. Common diluents are lubricating oil and liquid compounds containing only carbon and hydrogen. The diluent provides a minimum dilution of the reaction mixture to allow the mixture to be stirred efficiently.

The lubricating oil compositions containing the additives of the present invention can be prepared by mixing the appropriate amount of molybdenum-containing composition with a lubricating oil by conventional techniques. The choice of the particular base oil depends on the intended use of the lubricant and the presence of other additives. Generally, the amount of molybdenum-containing additive will range from 0.05 to 15 wt%, and preferably from 0.2 to 10 wt%.

The lubricating oil that can be used in the present invention includes a wide variety of hydrocarbon oils, such as oils or naphthene base, paraffin base and mixed base, as well as synthetic oils, such as esters and the like. The lubricating oils can be used individually or in combination and generally have a viscosity ranging from 50 to 5 * SUS and usually from 100 to 15,000 SUS at 38 ° C.

In many cases, it may be effective to form concentrates of the molybdenum-containing additive within a carrier liquid. These concentrates provide an efficient handling and transport method of the additives before their subsequent dilution and use. The concentration of the molybdenum-containing additive in the concentrate can range from 0.25 to 90% by weight, although it is preferable to maintain a concentration between 1 and 50% by weight. The ultimate application of the lubricating oil compositions of the present invention may be in marine cylinder lubricants, such as in crosshead diesel engines, crankcase lubricants such as in automobiles and rail cars, heavy machinery lubricants, such as steel processing equipment and the like or as bearing greases and the like. Whether the lubricant is liquid or solid will usually depend on whether a thickener is present. Common thickeners include polyurea acetates, lithium stearate and 80032 84 9 the like.

If desired, other additives may be included in the lubricating oil compositions of the present invention. These additives include antioxidants or oxidation inhibitors, dispersants, rust inhibitors, anti-corrosion agents, etc. Also, anti-foaming agents, stabilizers, anti-coloring agents, adhesives, anti-vibration agents, drop point improvers, anti-grinding agents, EP agents , odor control agents and the like are present. Certain molybdenum products which can be prepared by the process of the invention can also be used in the manufacture of brake lining materials, high temperature structural materials, in iron and steel alloys, in coating materials, in electrolytic coating solutions, as components of electric discharge machine electrodes, as fuel additives, for the production of self-lubricating or wear-resistant structures as mold release agents, in preparations for phosphating steel, in soldering fluxes, in nutrient media for microorganisms, for the production of electro-sensitive recording material, in catalysts for refining of coal, oil, clay shale, tar sands and the like or as stabilizers or curing agents for natural rubber or polymers.

Example I

To a 500 ml flask, 145 S of a 45% aqueous succinimide solution prepared from polyisobutenyl succinic anhydride and tetraethylene having a number average molecular weight for the polyisobutenyl group of about 980 and 75 ml of hydrocarbon diluent was added . The mixture was heated to 75 ° C and then 0.1 mole (26 g) (HH2O4SO4) in a pulverized state was added to the reaction mixture along with 35 ml of water. A nitrogen atmosphere was maintained in the reaction mixture, which mixture was heated to 65 ° 0 for 45 minutes.

The temperature was then raised to 95 ° C and water was removed. Heavy development of hydrogen sulfide and ammonia was observed. The temperature was raised to 155 ° C at reflux and maintained for one 40 hours. Then the mixture was filtered through β Λ Λ 7 9 O k diatomaceous earth and the filtrate was stripped to 160 ° C at 2.7 kPa to yield a product containing 4.78% molybdenum, 4.00% sulfur and 1. Contained 79% oxygen.

Example II

In the Oxidator B test, the stability of the oil is measured by the time required for the consumption of 1 liter of oxygen by 100 g of the tested oil at 171 ° C. The actual test uses 25 g of oil and the results are corrected to 100 g samples.

The catalyst used in an amount of 1.38 cm 2 per 100 cm 3 oil contains a mixture of soluble salts, which provide 95 ppm copper, 80 ppm iron, 4.8 ppm manganese, 1100 ppm lead and 49 ppm tin . The results of this run are reported as hours to consuming 1 liter of oxygen and our measure of the oxidative stability of the oil.

The anti-corrosion properties of preparations can be investigated by their behavior in the CEC L-38 lower corrosion test. In this test, separate strips of copper and lead are immersed in the lubricant to be tested and the lubricant is heated to a temperature of 146 ° C for 20 hours. The copper strip is weighed and then washed with a potassium cyanide solution to remove copper compound deposits. The strip is then weighed again. The weight losses of the two strips are reported as a measure of the degree of corrosion caused by the oil.

The copper strip test is a measure of corrosion against nonferrous metals and is described as ASTM Method D-130. Anti-wear properties are measured according to the 4-ball wear and 4-ball weld tests.

The 4-ball wear test is described in ASTM D-2266 and the 4-ball weld test in ASTM D-2783. The data for some of these experiments performed on compositions of the present invention are listed in the following table.

The coefficient of friction of an additive-containing lubricating oil of the present invention was examined with the Kinetic Oiliness Testing Machine (KOTM) of G.M.Heely 40 of Berkeley, California. The method used in this test is described by G-1.1. Neely, Proceeding of Mid-Year Meeting, American Petroleum Institute 1932, biz. 60-74 and in ASLE Transactions, 8, 1-11 (1965) and ASLE Transactions, 2 (1964) 24-31 # The coefficient of friction was measured under 5 boundary conditions at 150 ° C and 204 ° C using a load of 1 kg and a molybdenum-filled ring on a cast iron disc.

The formulation tested was a neutral oil containing 5.5% of a 50 percent solution of succinimide in 10 oil, 22mmol / kg of the product of Example I, 20mmol / kg of sulfurized calcium phenate, 50mmol / kg of basic magnesium sulfo contains 5.5% of a viscosity index improver and, if necessary, additional succinimide to bring the total nitrogen content of the final oil to 2.14%.

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Claims (13)

13 * -. 1. A process for preparing a sulfurized molybdenum-containing preparation, characterized in that ammonium tetrathiomolybdate and a basic nitrogen compound are combined to form a sulfur and molybdenum-containing preparation, 2. Process according to claim 1, characterized in that the basic nitrogen compound is a succinimide, carboxylic acid amide, hydrocarbon monoamine, hydrocarbon polyamine, Mannich base, phosphonamide, thiophosphonamide, phosphoramide or viscosity index improvers with dispersing action or using mixtures thereof, 3. Process according to claim 2, characterized in that as basic nitrogen compound a hydrocarbon succinimide with 24 to 350 carbon atoms in the hydrocarbon group, Carboxylic acid amide or a Mannich base * is prepared from an alkyl phenol with 9 to 200 carbon atoms in the alkyl group, formaldehyde and using an amine. 4. Process according to claim 3, characterized in that the basic nitrogen compound used is a polyisobutenyl succinimide prepared from polyisobutenyl succinic anhydride and tetraethylene pentamine or triethylene tetramine or mixtures thereof, 5. Process according to claim 3, characterized in that the basic nitrogen compound used is a carboxylic acid amide prepared from one or more carboxylic acids 2 of the formula R -C00H, wherein R represents an alkyl or alkenyl group with 12 to 350 carbon atoms and a hydrocarbon polyamine. 6. Process according to claim 5, characterized in that as the carboxylic acid amide a compound 2 is derived from a carboxylic acid of the formula R -C00H, wherein 2R represents an alkyl or alkenyl group with 12 to 20 carbon atoms and as hydrocarbon polyamine tetraethylene-35 apply pentamine or triethylenetetramine, Process according to claim 2, characterized in that the basic nitrogen compound is a hydrocarbon polyamine prepared from polyisobutenyl chloride and ethylenediamine, diethylene triamine, triethylene tetra-40 mine or tetraethylene pentamine or mixtures thereof. 800 3284 8. Process according to claim 3, characterized in that the basic nitrogen compound used is the Mannich base prepared from dodecylphenol, formaldehyde and methylamine, 9. Process according to claim 3, characterized in that the basic nitrogen compound used is a Mannich base prepared from an alkyl phenol with 80 to 100 carbon atoms in the alkyl part, formaldehyde and triethylene tetramine or tetraethylpentamine or mixtures thereof, 10. Process according to claims 1 to 9, characterized in that the reaction is carried out in the presence of a polar promoter. 11. A method according to claim 10, characterized in that water is used as the polar promoter, 12. Lubricating oil preparation characterized by the presence of an oil of lubricating viscosity and 0.05 to 13% by weight of one or more preparations obtained by one or more of the methods of one or more of the preceding claims, Lube oil concentrate, characterized by the presence of an oil of lubricating viscosity and 15 to 90% by weight of a composition obtained by one or more of the methods of any one of the preceding claims. ****** 800 3 2 84