JPS61285292A - Lubricant composition containing molybdenum - Google Patents

Abstract

PURPOSE:To provide a lubricant composition containing a specific oil-soluble molybdenum compound and a sulfur-containing compound as essential components, and having excellent oxidation resistance, abrasion resistance, lubricity and solubility in mineral oil and high corrosion resistance to metals such as copper, iron, etc. CONSTITUTION:The objective lubricant composition contains, as essential components (A) an oil-soluble molybdenum compound obtained by reacting molybdenum trioxide and/or molybdic acid (alkali metal salt) with a reducing agent and reacting the reaction product with a compound containing amino nitrogen atom (preferably 6-24C dialkylamine) and (B) a sulfur-containing compound. The component B is e.g. the compound of formula I-III (R1 and R2 are 3-24C hydrocarbon group; R3 is 7-24C hydrocarbon group; X is S or O). USE:Additive for preventing the pitting abrasion of various engine parts, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to novel oil-soluble molybdenum compounds useful as lubricating oil additives.

In particular, the present invention has antioxidant properties, anti-wear properties, friction mitigation properties,
The present invention relates to a lubricant composition containing an oil-soluble molybdenum compound that has excellent solubility in mineral oil and is particularly corrosive to metals such as copper and iron.

[Conventional technology and problems]

Conventionally, various compositions have been known as lubricant additives for engine oils, etc., but in recent years, the performance required of lubricant additives has become increasingly strict from the viewpoint of resource and energy conservation. Zinc dithiophosphate (hereinafter referred to as ZDTP) has conventionally been commonly used to improve anti-wear properties, and is Dialkylphosphorodithionate oxymolybdenum sulfide (hereinafter referred to as Mo-DTP) has also been used, as disclosed in et al.

However, both ZDTP and Mo-DTP contain phosphorus atoms, and in order to prevent the poisoning of automobile exhaust purification catalysts by phosphorus as part of air pollution prevention measures, the total amount of phosphorus that can be added is limited. There are limits to the amount of these compounds that can be used.

On the other hand, molybdenum dithiocarbamate (hereinafter Mo-DT)
Many compounds of type C) have also been reported (Special Publications No. 49-6362, No. 51-964, No. 53-Sho.
31646, Special Publication No. 56-12638, etc.).

Although these compounds pose no problem in terms of catalyst poisoning, they have major drawbacks such as unsatisfactory lubricity and poor solubility in base oils such as mineral oil.

These known ZDTP, Mo-DTP, Mo-DT
As mentioned above, C has various drawbacks, but a common drawback is that it is highly corrosive to metals.

[Means for interpreting the problem]

Conventionally, organic molybdenum compounds useful as lubricating additives have been required to contain sulfur atoms in their molecules. In other words, it was believed that the lubrication performance was achieved by the formation of molybdenum disulfide on the lubricated surface due to the molybdenum and sulfur contained within the molecule. However, the inventors
We thought that the active sulfur atoms contained in this molecule might have an adverse effect on the corrosion of metals, and conducted intensive research to resolve these two contradictory points. As a result, surprisingly, although the product of the reaction between reduced molybdic acid and amine has almost no performance as a lubricating additive when used alone, it has very good lubricating performance when combined with a sulfur-containing compound. There was found.

In other words, the lubricant composition of the present invention is a novel oil-soluble molybdenum compound produced by reducing molybdenum trioxide, molybdic acid, or an alkali salt thereof using a reducing agent and then reacting it with an amino nitrogen atom-containing compound. It contains a sulfur-containing compound as an essential component, has lubricating performance equivalent to or better than conventionally used ZDTP, Mo-DTP, and Mo-DTC, and has excellent metal corrosion resistance.

The molybdic acid used here may be an acid or an alkali salt thereof, or may be molybdenum trioxide, but it is preferable to contain an alkali salt of molybdate to the extent that the whole is uniformly dissolved in water.

Examples of the alkali salts used here include soda salts, potassium salts, ammonium salts, and the like.

The concentration of molybdic acid is not particularly limited, but it is preferably present in water at about 5 to 40% by weight, preferably about 10 to 20% by weight from the viewpoint of ease of reaction with amines, post-treatment, etc. Note that the reaction does not necessarily have to be completely dissolved, and the reaction proceeds even in a dispersed state.

The reaction between molybdic acid and its salts and the reducing agent is carried out in water between room temperature and 100°C. For example, when sodium hydrosulfite is used, the reaction time is 2 at 50°C.
Within 1 hour at 100°C is sufficient. When using other reducing agents, it is necessary to select the time and temperature according to the reducing power of the reducing agent.

The amount of the reducing agent used is preferably 1:0.5 to 1:5 equivalent, particularly preferably 1:1 equivalent, relative to molybdic acid and its salt.

As the reducing agent used here, any agent that can reduce hexavalent molybdenum to pentavalent or tetravalent molybdenum can be used, such as sodium sulfoxylate, sodium dithionite, sodium sulfite, sodium hydrogen sulfite, and Sodium sulfite, sodium thiosulfate, sodium dithionate, or other alkali metal or alkaline earth metal salts thereof, hydrogen sulfide, reducing sulfur compounds such as sulfur trioxide, glucose, maltose, lactose, maltotriose, malt Examples include one or more compounds selected from the group consisting of reducing sugars such as triose, aldehydes such as formaldehyde, acetaldehyde, and propionaldehyde, reducing acids such as formic acid, oxalic acid, and ascorbic acid, and their salts. It will be done.

The reaction between reduced molybdic acid and amines takes place from room temperature to 1
The temperature is between 00°C and 00°C. The reaction time is not particularly limited, but it is about 0.5 to 5 hours, usually about 1 hour. The molar ratio of molybdic acid and its salts to amines is 1:
A ratio between 1 and 1:4 is good, and a ratio of around 1:2 is particularly good. If the amount of amines is less than this, the oil solubility and yield will deteriorate,
If there is too much, unreacted amines will remain.

Thereafter, an oil-soluble molybdenum compound is obtained by neutralizing with an amount of acid corresponding to the alkali of the alkali salt of molybdic acid initially used and separating water.

The amino nitrogen atom-containing compounds used include monoamines having about 6 to 24 carbon atoms, such as methylamine,
Linear amines such as ethylamine, n-propylamine, n-butylamine, n-octylamine, laurylamine, stearylamine, branched amines such as isopropylamine, isobutylamine, 2-ethylhexylamine, branched tridecylamine. cyclohexylamine, alicyclic-class amines such as 2-methylcyclohexylamine, primary amines with aromatic ring substituents such as benzylamine and 4-methylbenzylamine, dimethylamine, diethylamine, di-n-propylamine, Linear secondary amines such as di-n-butylamine, di-n-octylamine, dilaurylamine, distearylamine, diisopropylamine, diisobutylamine, di-2-ethylhexylamine, branched di(tridecyl)amine, etc. Branched secondary amines, dicyclohexylamine, alicyclic secondary amines such as di-2-methylcyclohexylamine, secondary amines with aromatic ring substituents such as dibenzylamine and di-4-methylbenzylamine, methyl/n-butylamine,
Ethyl laurylamine, ethyl stearylamine,
Isopropyl n-octylamine, isobutyl 2-
Asymmetric secondary amines such as ethylhexylamine, cyclohexyl 2-ethylhexylamine, cyclohexyl benzylamine, stearyl benzylamine, 2-ethylhexyl benzylamine, trimethylamine,
Linear tertiary amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-octylamine, trilaurylamine, tristearylamine, triisopropylamine, triisobutylamine, tri-2-ethylhexylamine, branched tri- Branched tertiary amines such as (tridecyl)amine, alicyclic tertiary amines such as tricyclohexylamine, tertiary amines with aromatic ring substituents such as tribenzylamine, tri-4-methylbenzylamine, dimethyloctylamine, dimethino In addition, tertiary amines having a mixed hydrocarbon group such as laurylamine, dimethylsterylamine, diethyllaurylamine, dimethylbenzylamine, and dimethylcyclohexylamine, and amino Examples include dispersant-like amino compounds such as succinimide carboxylic acid amide and hydrocarbon polyamine having a nitrogen atom, or mixtures thereof.

Among these amines, dialkylamines having 6 to 24 carbon atoms are particularly preferable in terms of oil solubility of the product; dialkylamines with a carbon number shorter than this have poor solubility in oil and are not used as lubricating oils. The types of base oil used are limited. Furthermore, if the carbon number is longer than this, the effective concentration of molybdenum contained in the product will be lower.

Additionally, primary amines generally have poor solubility in oil, and tertiary amines result in poor product yields.

When using amines that are normally used in lubricating oils as ashless dispersants, such as succinimide of polyalkylene polyamines, the composition has a particularly fast dissolution rate in the base oil and also functions as a dispersant. can get.

Although any acid can be used as the neutralizing agent, mineral acids such as hydrochloric acid and sulfuric acid are more desirable from the viewpoint of cost and separation of the aqueous layer after the reaction.

As the sulfur-containing compound, which is another essential component of the present invention, almost all sulfur-containing compounds can be used, and since the molybdenum compound of the present invention does not contain phosphorus,
A phosphorus-containing compound can also be used, and if a compound containing molybdenum and sulfur is used, a composition with low metal corrosivity can be obtained without changing the total amount of molybdenum. Examples of sulfur-containing compounds include sulfurized fatty acids, sulfurized oils and fats, sulfurized oreduin, disulfide compounds such as dibenzyl disulfide, thiocarbamates such as butylphenol disulfide thiocarbamate,
Examples include phosphorus- and sulfur-containing compounds such as tetraalkylthioperoxyphosphate, molybdenum dithiocarbamate, molybdenum dithiophosphate, and zinc dithiophosphate.

Among these, when a compound represented by the general formula (in the formula, R is a hydrocarbon group having 3 to 24 carbon atoms and may be the same or different) is used, it is possible to obtain a composition that is particularly excellent in reducing the coefficient of friction and preventing wear. Become a thing.

In addition, compounds represented by the general formula (in the formula, R2 is a hydrocarbon group having 3 to 24 carbon atoms and may be the same or different), and compounds represented by the general formula (in the formula, R4 is a hydrocarbon group having 3 to 24 carbon atoms and the same However, when a compound represented by the formula (X is S or 0) is used, the composition is particularly excellent in reducing the coefficient of friction and preventing wear.

In addition, when using a compound represented by the general formula (wherein R1 is a hydrocarbon group having 7 to 24 carbon atoms and may be the same or different, and X is S or 0), the friction coefficient lowering ability is Although the composition is slightly inferior to that of the present invention, the composition has excellent anti-wear ability.

The ratio of the molybdenum compound to the sulfur-containing compound is 0.5 or more, preferably 1.5 or more sulfur atoms per molybdenum 1 atom.
It is good that it is 5 or more. There is no particular upper limit, and sulfur-containing compounds may be added in large amounts as additives to lubricants.

However, the upper limit is usually a molybdenum/sulfur ratio of about 50.

The compounds of this invention are useful as lubricant additives. A lubricant is usually composed of a base oil or a base material, and various additives added depending on the application, and the compound of the present invention can be used in combination with these base oils, base materials, and additives as appropriate. I can do it.

As the base oil/base material, natural oils include animal oils, vegetable oils, oils obtained from petroleum, paraffinic oils, naphthenic oils, and mixtures thereof.

Synthetic lubricating oils include olefin polymers and copolymers (e.g. polybutylene, polypropylene, propylene-
Isobutylene copolymer, polybutylene chloride, poly (1
-hexene), poly(1-octene), poly(1-decene), etc. and mixtures thereof), alkylbenzenes (e.g. dodecylbenzene, tetradodecylbenzene, dinonylbenzene, di(2-ethylhexyl)hensen, etc.),
Included are hydrocarbon oils and halogen-substituted hydrocarbon oils such as polyphenyls (eg, biphenyl, terphenyl, alkyl polyphenyl, etc.), alkyl diphenyl ethers and alkyl diphenyl sulfides, and their derivatives, analogs and congeners. Mention may be made of oils obtained by polymerization of ethylene oxide or propylene oxide, alkyl and aryl ethers of these polyoxyalkylene polymers, and mono- or polyhydric carboxylic acid esters or diesters thereof. Also, dicarboxylic acids (for example, phthalic acid, succinic acid, alkylsuccinic acid and alkenylsuccinic acid, sebacic acid, adipic acid, linoleic acid dimer, etc.)
and esters of various alcohols. Useful esters also include nistelmo made from polyhydric alcohol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, and the like. or,
Silicic oils such as polyalkyl-, polyaryl-, polyalkoxy- or polyaryloxy-siloxane oils and silicate oils, liquid esters of phosphorus-containing acids (TCP
, TOP, diethyl ester of decylphosphonic acid), etc.

Various additives that are added depending on the application include, for example, ash-forming or ashless type auxiliary detergents and dispersants, corrosion and antioxidants, pour point depressants, extreme pressure agents, oil-based agents, colorants and erasers. Examples include foaming agents.

Ash-forming detergents are alkali metal or alkaline earth metal sulfuric acids, carboxylic acids, or olefin polymers such as phosphorus trichloride, phosphorus trisulfide, trichloride.

It is typified by a fat-soluble neutral or basic salt such as an organic phosphoric acid having at least one bond in which carbon and phosphorus are directly bonded, obtained by treatment with a phosphating agent such as carbon and sulfur. The most commonly used are sodium, potassium, lithium,
It is a salt of calcium, magnesium, strontium and barium.

Ashless detergents include carboxylic acid dispersants, amine dispersants, Mannin dispersants, fat-soluble monomers such as decyl methacrylate, vinyl decyl ether, and large molecular weight olefins, and polar monomers such as aminoalkyl acrylates. Examples include copolymers with monomers containing certain substituents.

Oil-based agents, extreme pressure agents, corrosion and antioxidant agents are represented by the following:

1) Chlorinated aliphatic hydrocarbons 2) Benzyl disulfide, bis(chlorobenzyl) disulfide,
Diptyl tetrasulfide, sulfurized methyl ester of olefinic acids,
organic sulfides and polysulfides of sulfurized alkylphenols, sulfurized dipentenes and sulfurized terpenes; 3) phosphorus sulfide hydrocarbons, such as reaction products of phosphorus sulfide with turpentine and methyl olefinate; 4) dibutyl, diheptyl phosphorous acids; Phosphate esters mainly containing dihydrocarbon and trihydrocarbon phosphites such as dicyclohexyl, pentylphenyl, diethyl ethyl, dioctyl, tridecyl, distearyl, dimethylnaphthyl, diisobutyl substituted phenyl, tricresyl phosphate, trioctyl phosphate, tributyl Phosphate esters such as phosphate, triphenyl phosphate, nonylphenyl phosphate, etc. 5) Zinc dioctyl carbamate, zinc diisoamyl dithiocarbamate and barium heptyl phenyl dithiocarbamate, antimony diisoamyl dithiocarbamate, oxymolybdenum ditridecyl dithiocarbamate sulfide, di-2 -Thiocarbamate metal salts such as oxymolybdenum sulfide ethylhexyldithiocarbamate, oxymolybdenum sulfide dibutyldithiocarbamate 6) Zinc dicyclohexylphosphorodithioate, zinc dioctylphosphorodithioate, barium di(heptylphenyl)phosphorodithioate, dinonyl Group II metal salts of phosphorodithioic acid, such as cadmium phosphorodithioic acid, and zinc salts of phosphorodithioic acid obtained by reaction of trivalent phosphorus with a mixture of equimolar amounts of isopropyl alcohol and n-hexyl alcohol; phosphorodithioic acid; Oxymolybdenum sulfide salts 7) Oily agents such as oleyl alcohol, stearyl alcohol, stearic acid, isostearic acid, oleic acid Among these, sulfur-containing compounds are one of the requirements of the present invention. It will also be used as a compound.

The uses of the lubricant using the compound of the present invention are not particularly limited, and specific uses include automobile and truck engines, two-stroke engines, aircraft piston engines, marine and locomotive diesel engines, etc. Crankcase lubricants for spark-ignition and compression-ignition internal combustion engines, lubricants for gas engines, stationary power engines and turbines, automatic transmission fluids, transaxle lubricants, gear lubricants, metalworking lubricants, hydraulic fluids. and other lubricating oils and grease compositions.

〔Example〕

Example-1 1 mol of sodium molybdate was mixed with 540 ml of water under a nitrogen stream.
Sodium hydrosulfide l-0,
17 mol was added and a distant reaction was carried out at 50 to 60°C for about 1 hour. Then 2 moles of ditridecylamine were added to 50-6
The mixture was added dropwise over 1 hour while maintaining the temperature at 0°C, and was further aged at the same temperature for 1 hour. After that, it was neutralized with 1 mol of 30% sulfuric acid water, the aqueous layer was separated and removed, and dehydration was performed under reduced pressure to produce a green oily product 81.
Obtained 0g. The molybdenum content was 11.0% and the yield for molybdenum was 92.8%.

Example-2 1 mol of sodium molybdate was mixed with 540 ml of water under a nitrogen stream.
0.1 radium hydrosulfite dissolved in m1
A far-field reaction was performed. Next, 1 mol of di(2-ethylhexyl)amine was added dropwise over 1 hour while maintaining the temperature at 50 to 60°C, and the mixture was further aged at the same temperature for 1 hour.

After that, neutralize with 1 mol of 30% sulfuric acid water, separate and remove the aqueous layer,
Dehydration was carried out under reduced pressure to obtain 475 g of a dark green oily product. The molybdenum content was 13.2% and the yield on molybdenum was 65.3%.

Example-3 1 mol of molybdenum trioxide in 540 ml of water in a nitrogen stream
After adding 0.8 mol of caustic soda to make a homogeneous solution, 0.17 mol of sodium hydrosulfite was added, and a distance reaction was carried out at 50 to 60°C for about 1 hour. Next, 2 mol of dibenzylamine was added dropwise over 1 hour while maintaining the temperature at 50 to 60°C, and the mixture was further aged at the same temperature for 1 hour. Thereafter, the mixture was neutralized with 0.8 mol of 30% hydrochloric acid, the aqueous layer was separated and removed, and dehydration was performed under reduced pressure to obtain 450 g of a green-blue oily product.

The molybdenum content was 18.8% and the yield on molybdenum was 88.1%.

Example-4 1 mol of sodium molybdate was mixed with 540 ml of water in a nitrogen stream.
n+1 and radium hydrosulfide 0.
A 1-f far field reaction was performed. Next, 2 mol of tridecylamine was added dropwise over 1 hour while maintaining the temperature at 50 to 60°C, and the mixture was further aged at the same temperature for 1 hour. Thereafter, the mixture was neutralized with 1 mol of 30% sulfuric acid water, the aqueous layer was separated and removed, and dehydration was performed under reduced pressure to obtain 505 g of a green oily product. The molybdenum content was 17.8% and the yield for molybdenum was 93.6%.

Example 5 1 mol of sodium molybdate was dissolved in 54 liters of water in a nitrogen stream, and a radium hydrosulfide 0.1 liter reaction was carried out. Next, 2 mol of dimethyl laurylamine was added dropwise over 1 hour while maintaining the temperature at 50 to 60°C, and the mixture was further aged at the same temperature for 1 hour. Thereafter, the mixture was neutralized with 1 mol of 30% sulfuric acid water, the aqueous layer was separated and removed, and dehydration was performed under reduced pressure to obtain 505 g of a greenish-brown oily product. Molybdenum content is 1
2.5% and the yield for molybdenum is 65.
It was 8%.

Example-6 Reduced sodium molybdate solution 1 produced in the same manner as Example 1
2 moles of succinimide (molecular weight approximately 1.00
Mineral oil solution containing 50% of succinic anhydride and tetraethylenepentamine reactant having 0 polyisobutenyl groups)
50-60 as a solution dissolved in 250ml of benzene
The mixture was added dropwise over 1 hour while maintaining the temperature at °C, and was further aged at the same temperature for 2 hours. This 11t was neutralized with 1 mol of 30% sulfuric acid water, the aqueous layer was separated and removed, dehydration was carried out under reduced pressure, and debenzene was performed to obtain 4,055 g of a greenish-brown oily product. The molybdenum content is 2.2% and the yield for molybdenum is 92.
It was 9%.

Example-7 2 moles of benzyl polyamine (mineral oil solution containing 50% of benzyl chloride and diethylene triamine 2:1 reactant) was dissolved in 200 ml of benzene in 1 mole of the reduced sodium molybdate solution produced in the same manner as in Example-1. The resulting liquid was subjected to post-reaction treatment in the same manner as in Example 6 to obtain 1,180 g of a dark green oily product. Molybdenum content is 7.2%, yield for molybdenum is 88,
It was 5%.

Example-8 Example-1 obtained in Examples 1.2, 3, 4.5.6.7
A composition obtained by blending the compounds obtained in Examples 1 to 7 with various sulfur-containing compounds was dissolved in 150 neutral oil with a molybdenum content of 0.06% by weight, and the anti-wear properties were evaluated as Shell 4.
Measured with a ball tester (oil temperature 80°C, load 40 dazzle, 1,
(Displayed as the diameter of the wear scar after 30 minutes at 800 rpm).

In addition, the friction coefficient was measured using a pendulum type oil tester (oil temperature 80
°C, load 600g, average of 50 times).

The results are shown in Table 3.

Example 11 The friction reduction effect of the compounds obtained in each example and comparative example was measured using a reciprocating vibration friction tester (oil temperature 120°C, load 2.
2kgf, 12.2kgf, 22.2kgf,
Vibration frequency: 50 Orpm, amplitude: 2.5 m, concentration: 0.04% by weight as MO, sulfur compound: 0.06% by weight as S
, test piece material 5UJ-2, test piece shape; upper 3/4 inch sphere, lower flat plate).

The results are shown in Table 4.

〔Effect of the invention〕

The effects of the present invention provide a novel molybdenum amine complex,
By using this in combination with a sulfur-containing compound,
The object of the present invention is to provide a lubricating oil additive that has superior anti-oxidation properties, anti-wear properties, and friction mitigation properties over conventionally used ZDTP- or molybdenum-containing lubricating additives, and is particularly excellent in metal corrosion resistance. . Since it has excellent metal corrosive properties, it can also be an excellent additive for pitting wear of various engine parts that occur.

Claims (1)

[Claims] 1. A compound obtained by reacting one or more compounds selected from molybdenum trioxide, molybdic acid, or an alkali salt thereof with a reducing agent and then reacting with an amino nitrogen atom-containing compound. A lubricant composition comprising an oil-soluble molybdenum compound and a sulfur-containing compound as essential components. 2. The lubricant composition according to claim 1, wherein the amino nitrogen atom-containing compound is a dialkylamine having 6 to 24 carbon atoms. 3. The lubricant composition according to claim 1, wherein the amino nitrogen atom-containing compound is an amino group-containing ashless dispersant for lubricants. 4. A patent where the compound containing sulfur is a compound represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_1 is a hydrocarbon group having 3 to 24 carbon atoms and may be the same or different) A composition according to any one of claims 1 to 3. 5. A patent claim where the sulfur-containing compound is a compound represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_2 is a hydrocarbon group having 3 to 24 carbon atoms and may be the same or different) The composition according to any one of the ranges 1 to 3. 6. Compounds containing sulfur have the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_3 is a hydrocarbon group having 7 to 24 carbon atoms and may be the same or different, and X is S or O.) The composition according to any one of claims 1 to 3, which is a compound represented by: 7. Compounds containing sulfur have the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_4 is a hydrocarbon group having 3 to 24 carbon atoms and may be the same or different, and X is S or O.) The composition according to any one of claims 1 to 3, which is a compound represented by: