JP2004124095A - Lubricant composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant composition which is improved in the friction decreasing characteristics. <P>SOLUTION: The lubricant composition comprises a large amount of a lubricating viscous oil and small amounts of the following (A) and (B): (A) a mixture of an oil-soluble or oil-dispersible salt of dihydrocarbylthiophosphoric acid which can be derived from a reaction of phosphorus sulfide with the following (I) or (II), with said (I) being a compound (P) separating at least two groups selected independently from hydroxy (OH) group and sulfhydryl (SH) group by at least four atoms or with said (II) being two or more compounds containing the compound (P) described in the above (I), and of one or more compounds having at least one group selected from a hydroxy (OH) group and a sulfhydryl (SH) group; and (B) an oil-soluble or oil-dispersible molybdenum compound. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a lubricant composition comprising certain salts of dihydrocarbyl thiophosphoric acid and a molybdenum compound. It has been found that the combination of certain salts of dihydrocarbyl thiophosphoric acids with molybdenum compounds improves the friction reducing properties.

There is a need for lubricant compositions, particularly crankcase lubricant compositions, that provide improved fuel economy and fuel retention properties to internal combustion engines, thereby minimizing fuel consumption. . Molybdenum-containing components have been used in crankcase lubricant compositions to improve the fuel economy and fuel retention characteristics of engines.
Dithiophosphate salts, especially zinc salts, are also used in the lubricant composition, primarily for wear protection on the engine and oxidation control on the lubricant composition. Such salts are generally alcohols, typically mono - is reacted with an alcohol of phosphorus pentasulfide (P ₂ S _5), and thereafter, the resulting acid, typically neutralized with metal salts It is manufactured by
The use of salts of dithiophosphoric acids derived from polyols is known in the art. For example, US 4,778,906 discloses a zinc salt of a dialkyldithiophosphoric acid obtained from a mixture of an aliphatic monohydric alcohol and a polyol.
US 5,013,465 discloses metal dithiophosphates obtained from a mixture of alcohols and diols, the metals of which are zinc, molybdenum and copper.

US Pat. No. 5,919,740 discloses sodium, potassium, lithium or oil-soluble dialkyldithiophosphates prepared by reacting P ₂ S ₅ with an alcohol mixture consisting of certain polyols and certain monohydric alcohols. Amine salts are disclosed.
US 4,259,192 discloses oil-soluble dithiophosphates based on poly (oxyalkylene) alcohols as additives for lubricating oil compositions.
US 3,944,495 discloses metal salts wherein the dithiophosphate is prepared from an ether or an alcohol containing a sulfur bond.
US 3,029,268 discloses phosphorodithioic acids prepared from alcohols, wherein the aliphatic group may contain inert substituents such as ethers, esters, nitro and sulfides.
The US4,450,096 generation, the P ₂ S _5, is reacted with the hydrocarbyl vicinal Nord diol carbon atoms 12 to 20, and then the product is formed by reacting a metal oxide or a metal salt Is disclosed.

It has been found that when certain salts of dihydrocarbyl thiophosphoric acid and molybdenum compounds are used in combination, the friction reducing properties are improved.
Therefore, in a first aspect, according to the present invention,
There is provided a lubricating oil composition comprising a major amount of a lubricating viscosity oil and a minor amount of the following (A) and (B) added to or mixed therewith:
(A) Oil-soluble or oil-dispersible salts of dihydrocarbylthiophosphoric acids derivable by the reaction of phosphorus sulfide with the following (I) or (II):
(I) A compound (P) having at least two groups independently selected from hydroxyl (OH) and sulfhydryl (SH), and separating two groups, preferably any two groups, in the compound (P) And (II) two or more compounds including the compound (P) described in (I), and at least four, preferably at least five, atoms, and hydroxyl (OH) or sulfhydryl (SH) A mixture with one or more compounds having at least one group selected; and (B) an oil-soluble or oil-dispersible molybdenum compound.

In a second aspect, according to the present invention, an additive suitable for preparing a diluent fluid and a lubricant composition comprising (A) and (B) according to the first aspect added to or mixed therewith. A concentrated composition is provided.
In a third aspect, the present invention provides a method for improving the frictional properties of a lubricant composition or for improving fuel economy and / or fuel economy retention of an engine lubricated with the lubricant composition. There is provided the use of (A) and (B) according to the first aspect in a lubricant composition.
In a fourth aspect, the present invention provides a method for producing the lubricant composition according to the first aspect, comprising a large amount of a lubricating viscosity oil and a small amount of the additive concentrate composition according to the second aspect or a small amount. A method comprising blending (A) and (B) according to the first aspect of the invention.
In a fifth aspect, the present invention provides a method for lubricating a surface, comprising the step of applying a lubricant composition according to the first aspect or a lubricant composition produced by the method according to the fourth aspect to a surface. A method is provided that includes applying.

In a sixth aspect, the present invention provides an oil-soluble or oil-dispersible salt of dihydrocarbyl thiophosphoric acid derivable by reacting phosphorus sulfide with the following (I) or (II):
(I) A compound (P ′) having at least two groups independently selected from hydroxyl (OH) and sulfhydryl (SH), and two groups in the compound (P ′), preferably two arbitrary groups Is present, and at least one of the atoms separating two groups, preferably any two, in compound (P ') is oxygen, sulfur or nitrogen Or (II) two or more compounds including the compound (P ') according to (I) and one or two compounds having at least one group selected from hydroxyl (OH) or sulfhydryl (SH). Mixtures of the above compounds.

In a seventh aspect, the present invention provides an additive comprising the oil-soluble or oil-dispersible salt according to the sixth aspect, and optionally comprising a diluent fluid.
In an eighth aspect, the present invention provides an additive concentrate composition comprising a diluent fluid and an additive according to the seventh aspect and one or more co-additives added thereto or mixed therewith. You.
In a ninth aspect, according to the present invention, comprises a large amount of a lubricating viscosity oil and a small amount of the additive concentrate composition according to the eighth aspect or the additive according to the seventh aspect added to or mixed therewith. A lubricant composition is provided.
In a tenth aspect, the present invention provides a dihydrocarbyl thiophosphate according to the sixth aspect.
The features of the present invention are described in detail below.

Lubricant composition The lubricant composition according to any suitable aspect may be any composition suitable for lubricating surfaces, examples of such compositions include those for passenger cars, trucks and tractors. And crankcase lubricants for railway and other industrial engines, such as marine trunk piston engines; two-stroke engine oils; and industrial lubricants, such as gear oils, metal working and metal cutting fluids, compressor oils and cooling oils. Is mentioned. Preferably, the lubricant composition is a crankcase lubricant, more preferably a crankcase lubricant for either or both cars or trucks, operable by spark or compression ignition.
In one embodiment, the phosphorus content of the lubricant composition is at most 0.15% by weight, such as at most 0.1 or at most 0.09% by weight, preferably at most 0. 0% by weight, based on the weight of the lubricant composition. 08 or at most 0.07% by weight, preferably at most 0.06% by weight, in particular at most 0.05% by weight, for example at most 0.04 or at most 0.03% by weight. Preferably, the phosphorus content in the lubricant composition is at least 0.01% by weight.

In one embodiment, independently of the other embodiments, the lubricant composition has a sulfated ash content of less than 1.5% by weight, especially less than 1.3% by weight, measured according to ASTM D874. Advantageously less than 1.0% by weight, preferably less than 0.9% by weight, for example from 0.01 to 0.5% by weight.
Preferably, the lubricant composition is a multigrade specified by the descriptor SAE 5W-20 or SAE 5W-30, the properties of which are described in the publication SAE J300 of the Society of Automotive Engineers.
The oil of lubricating viscosity may be a synthetic or mineral oil of lubricating viscosity selected from the group consisting of any of Group I, II, III, IV and V basestocks and mixtures thereof. Definitions of Group I, II, III, IV and V basestocks can be found in the American Petroleum Institute (API) 1509 "Engine Oil Licensing and Cetification System" Fourteenth Edition, December 1996.
The base stock can be produced using a variety of different methods, including, but not limited to, distillation, solvent purification, hydrotreating, oligomerization, esterification, and re-purification.

Dihydrocarbyl thiophosphate Phosphorus- soluble or oil-dispersible salts of dihydrocarbyl thiophosphate suitable for use in the present invention typically comprise one or more oil-soluble or oil-dispersible salts of dihydrocarbyl thiophosphate. And optionally in the form of an additive which may comprise a diluent fluid, for example a lubricating viscosity oil.
Regarding the first to fifth aspects, it has been found that the combination of the following (A) and (B) can impart good friction reducing properties to the lubricant composition:
(A) Oil-soluble or oil-dispersible salts of dihydrocarbylthiophosphoric acids derivable by the reaction of phosphorus sulfide with the following (I) or (II):
(I) A compound (P) having at least two groups independently selected from hydroxyl (OH) and sulfhydryl (SH), and separating two groups, preferably any two groups, in the compound (P) And (II) two or more compounds including the compound (P) described in (I), and at least four, preferably at least five, atoms, and hydroxyl (OH) or sulfhydryl (SH) A mixture with one or more compounds having at least one group selected; and (B) an oil-soluble or oil-dispersible molybdenum compound.

With regard to the sixth to ninth aspects, a lubricant composition is provided by an oil-soluble or oil-dispersible salt of dihydrocarbyl thiophosphoric acid which is derivable, preferably derived by reacting phosphorus sulfide with (I) or (II) It has been found that performance in the interior is imparted, such as antioxidant and abrasion resistance:
(I) A compound (P ′) having at least two groups independently selected from hydroxyl (OH) and sulfhydryl (SH), and two groups in the compound (P ′), preferably two arbitrary groups Is present, and at least one of the atoms separating two groups, preferably any two, in compound (P ') is oxygen, sulfur or nitrogen Or (II) two or more compounds including the compound (P ') according to (I) and one or two compounds having at least one group selected from hydroxyl (OH) or sulfhydryl (SH). Mixtures of the above compounds.

Thus, with respect to the first to fifth aspects, compound (P) is used alone or in admixture with the compound to produce dihydrocarbyl thiophosphate, which is then reacted with a source of cation to form a salt (A ) Is formed.
Similarly, compound (P '), alone or in a mixture, forms a salt according to the sixth to ninth aspects. To avoid doubt, compound (P ') is a preferred embodiment of compound (P).
The compound used to make the dihydrocarbyl thiophosphoric acid can be represented by ROH or RSH, wherein R represents a hydrocarbyl group, or a substituted derivative thereof, which is optionally independently hydroxyl (OH) or It may contain one or more groups selected from sulfhydryl (SH); when the compound is compound (P), R is independently hydroxyl (OH) or sulfhydryl (SH) Represents a hydrocarbyl containing one or more selected groups, or a substituted derivative thereof, wherein the compound (P) has at least 4 atoms, preferably 2 atoms, separating two groups, preferably any two groups, preferably There are five.

The hydrocarbyl group R is preferably free of unsaturation, whether acetylenically unsaturated or ethylenically unsaturated. Preferably, the number of carbon atoms of the hydrocarbyl group R is between 1 and 50, more preferably between 1 and 30, especially between 3 and 18, advantageously between 3 and 8. Examples of R include: alkyl, such as ethyl, n-propyl, i-propyl, n-butyl, i-butyl; sec-butyl, amyl, n-hexyl; i-hexyl, n- Heptyl, n-octyl, and decyl; cycloalkyl; alkyl-substituted cycloalkyl; aryl, such as phenyl and naphthyl; alkylaryl; arylalkyl; alkoxyalkyl; alkoxyaryl; and substituted derivatives thereof, such as oxygen interrupting the alkyl chain Or a compound containing a sulfur atom, such as R ³ XR ⁴ , wherein X represents an oxygen, sulfur or NR ⁵ group, and R ³ and R ⁴ independently represent a hydrocarbyl group as described above for R; , R ⁵ represent hydrogen or a hydrocarbyl group as described above for R). When the hydrocarbyl group R also represents a substituted derivative of the hydrocarbyl group, it may contain other substituents, for example carboxylic acids or derivatives thereof, N-containing groups, for example amines.

Common examples of compounds include aliphatic or aromatic alcohols, thiols, and substituted derivatives thereof.
Specific examples of the substituted compounds are disclosed in US-A-4,244,827, 5,013,465, 3,029,268, 4,259,192, 3,944,495, 4,410,434, 4,400,283 and 5,306,436.
Preferably, compound (P) has at least three, more preferably at most four, groups independently selected from hydroxyl (OH) or sulfhydryl (SH) groups.
In certain embodiments, compound (P) has at least two hydroxyl groups, and more preferably, compound (P) has only two hydroxyl groups.
In another embodiment, independently of the other embodiments, the number of atoms separating two groups, preferably any two groups, in compound (P) is at least 6, more preferably at least 6. 7, for example 8-10. To avoid doubt, the number of atoms separating any two groups is based on those atoms which form a direct connection between the two groups.
The atoms separating the groups in compound (P) can be independently selected from carbon, oxygen, nitrogen or sulfur.

Preferably, when at least one atom separating two groups, preferably any two groups in the compound (P) is selected from oxygen, sulfur or nitrogen, more preferably from oxygen or sulfur, Compound (P ') is used to produce dihydrocarbyl thiophosphoric acid.
In a preferred embodiment, compound (P ') has carbon and oxygen atoms separating two groups, preferably any two groups; more preferably, compound (P') has two groups, Preferably it has one oxygen atom between the atoms separating any two groups.
Preferably, the dihydrocarbyl thiophosphoric acid is derivable by reaction of phosphorus sulfide with a mixture of two or more compounds, provided that the mixture is a compound (M) having one group selected from hydroxyl or sulfhydryl And compound (P).
In a preferred embodiment, the dihydrocarbyl thiophosphoric acid is derivatizable by reaction of phosphorus sulfide with essentially a mixture of compound (M) and compound (P).
In some embodiments, compound (M) has one hydroxyl group.

If a mixture containing two or more compounds is used in the preparation of dihydrocarbylthiophosphoric acid, the amount of compound (P) present in the mixture based on hydroxyl and sulfhydryl groups, Of at most 50 mol%, more preferably at most 40 mol%, especially at most 30 mol%, advantageously at most 25 mol%, for example 5 to 20 mol%, for example 7 to 10 mol%, based on the total hydroxyl and sulfhydryl groups of 15 mol%. For the avoidance of doubt, the amount of compound (P) in a mixture may also be up to 50 equivalent%, more preferably up to 40 equivalent%, especially up to 40 equivalent%, based on the total equivalents of the compound in the mixture. It can be expressed as a maximum of 30 equivalent%, advantageously a maximum of 25 equivalent%, for example 5 to 20 equivalent%, for example 7 to 15 equivalent%.
The embodiments described above for compound (P) are also applicable to compound (P ').
The hydroxyl and sulfhydryl groups in compounds such as compound (M), compound (P) and compound (P ′) are independently primary, secondary or tertiary carbon atoms, or aromatic carbon atoms in compounds. , Preferably to a primary or secondary carbon atom. Preferably, each of compound (P), compound (P ') and compound (M) is selected from acrylic compounds.

Examples of compound (P) include: 1,5-pentanediol, 3-methyl-1,5-hexanediol (having 5 carbon atoms separating two hydroxyl groups), 1,6-hexanediol, products derived from the reaction of glycols, such as ethylene glycol, propylene glycol and butylene glycol, and alkylene oxides, such as ethylene oxide, propylene oxide, butylene oxide, such as diethylene glycol, dipropylene glycol and isomers thereof body. Preferably, compound (P) is selected from 1,6-hexanediol or dipropylene glycol, more preferably dipropylene glycol, such as 2,4-methyl-3-oxa-1,5-pentanediol, It is selected from oxa-2,6-heptanediol and 2-methyl-3-oxa-1,5-hexanediol.

Examples of the compound (P ′) include thioether polyols and ether polyols, for example, diethylene glycol and dipropylene glycol, for example, 2,4-methyl-3-oxa-1,5-pentanediol, 4-oxa-2,6-heptane Diols and 2-methyl-3-oxa-1,5-hexanediol.
Examples of compounds (M) are monoalcohols, ie compounds having only one OH group, which are aliphatic monoalcohols, preferably having 3 to 18 carbon atoms. Specific examples include 1-propanol, 2-propanol, 1-butanol, 2-methyl-1-propanol, 2-butanol, 5-pentanol, 4-methyl-2-pentanol, isooctanol, and 2-ethyl- Examples include 1-hexanol, 2-octanol, 2-nonanol, 1-decanol and 1-tridecanol.

The salt of dihydrocarbyl thiophosphoric acid is preferably an amine salt, an ammonium salt, or a salt of a metal selected from alkali metals, alkaline earth metals and transition metals.
Examples of suitable metals include sodium, lithium, potassium, calcium, magnesium, molybdenum, tungsten and zinc. When (A) is a molybdenum salt, (B) is a compound different from the molybdenum salt (A).
Examples of amines are primary, secondary and tertiary aliphatic amines.
Zinc is preferred.
In general, methods for making salts of dihydrocarbyl thiophosphate are known in the art and include reacting ditiderocarbyl thiophosphate with a source of cation, such as a metal. Such a method is also applicable to the salts of dihydrocarbylthiophosphates according to the invention: see, for example, EP-A-0 516 461, WO 01/44419 and US-A-5,919,740.

A method for producing dihydrocarbyl thiophosphoric acid, in particular, a method for producing dihydrocarbyl dithiophosphoric acid is a method for producing phosphorus sulfide, for example, phosphorus pentasulfide and one or more alcohols, wherein each type of alcohol is a monoalcohol. In some cases, this involves reacting in a molar ratio of about 1: 4. Generally, the molar ratio is such that there is a slight excess of alcohol so that the phosphorus sulfide is fully utilized in the reaction.
Generally, the process for producing dihydrocarbyl thiophosphoric acid comprises reacting phosphorus sulfide with one or more compounds, such as alcohols, at 50-200 ° C for 1-10 hours. Hydrogen sulfide is liberated during the reaction. The molar ratio of phosphorus sulfide to compound depends on the phosphorus sulfide and compound used. After the dihydrocarbyl thiophosphate reaction is completed, the acid product can be stripped and cooled with an inert gas, such as nitrogen, to remove any traces of hydrogen sulfide. Unreacted compounds, P ₂ S ₅ or other solids can be removed by decantation, filtration or centrifugation.

Phosphorus _{sulfide, P 2 S 3, P 2} S 5, P 4 S 7, P 4 S 3, P 4 S can be selected from one or more of _9; is phosphorus pentasulfide (P ₂ S _5), It is a preferred phosphorus sulfide source. Although the actual structure of phosphorus pentasulfide is assumed to be P ₄ S _10, it is described in the present invention as P ₂ S ₅ .
The process for preparing a salt of dihydrocarbyl thiophosphoric acid of the present invention comprises producing dihydrocarbyl thiophosphoric acid and then neutralizing the acid with a source of cation.
The dihydrocarbyl thiophosphoric acid can be neutralized by contact with a source of cations such as metal salts such as metal oxides, hydroxides and carbonates, or ammonium cation sources such as amines and ammonia. The temperature and pressure conditions vary depending on the cation source and the acid to be neutralized.
The molar ratio of dihydrocarbyl thiophosphoric acid to cation source is typically based on one equivalent of acid to one equivalent of cation source. Such products are called "neutral" products.

When the cation source is a zinc salt, a basic thiophosphate is preferred when the cation source is in excess, ie, more than one equivalent of cation source to one equivalent of acid.
According to a method applicable to the method for producing a salt of dihydrocarbyl thiophosphoric acid of the present invention:
Using alcohols and / or carboxylic acids or their salts to reduce the proportion of precipitates in the preparation of salts of thiophosphonic acids (see, for example, US Pat. No. 5,627,294);
-Treatment of the thiophosphonic acid with further phosphorus sulphide before neutralization to obtain a metal salt with the desired metal to phosphorus ratio (see, for example, US-A-5,384,054); or-a metal with the desired surface area The oxide is used to obtain a metal salt having the desired metal to phosphorus ratio (see, for example, US Pat. No. 5,380,448).
In a preferred embodiment, the salt of dihydrocarbyl thiophosphoric acid in a suitable aspect of the present invention comprises phosphorus pentasulfide and 2-methyl-4-pentanol and either 1,6-hexanediol or dipropylene glycol. A zinc salt of dihydrocarbylthiophosphoric acid derived by reaction with a mixture, preferably a mixture comprising 2-methyl-4-pentanol and dipropylene glycol.

In a preferred embodiment of the seventh aspect, the additive comprises the oil-soluble or oil-dispersible salt of the sixth aspect and a diluent fluid.
In one embodiment, the phosphorus content of the lubricant composition is at most 0.15% by weight, such as at most 0.1 or at most 0.09% by weight, preferably at most 0. 0% by weight, based on the weight of the lubricant composition. 08 or at most 0.07% by weight, preferably at most 0.06% by weight, in particular at most 0.05% by weight, for example at most 0.04 or at most 0.03% by weight. Preferably, the phosphorus content in the lubricant composition is at least 0.01% by weight.
In the lubricant composition, the content of phosphorus derived from the salts of dihydrocarbylthiophosphates according to the invention is preferably at most 0.15% by weight, for example at most 0.1 or at most 0.09% by weight, preferably at most 0%. 0.08 or at most 0.07% by weight, advantageously at most 0.06% by weight, in particular at most 0.05% by weight, for example at most 0.04 or at most 0.03% by weight, most preferably at least 0.01% by weight %.

Molybdenum Compounds Oil-soluble or oil-dispersible molybdenum compounds suitable for use in the present invention are typically in the form of a molybdenum additive comprising one or more oil-soluble or oil-dispersible molybdenum compounds. In a preferred embodiment, the molybdenum compound is a molybdenum-sulfur compound.
Molybdenum-sulfur compounds useful in the present invention may be mononuclear or polynuclear. When the compound is polynuclear, it contains a molybdenum core consisting of non-metallic atoms, such as sulfur, oxygen and selenium, preferably consisting essentially of sulfur.
One or more ligands are attached to molybdenum atoms in the compound to ensure that the molybdenum-sulfur compound is oil-soluble or oil-dispersible. Ligand binding includes binding via covalent and electrostatic bonding forms and electrostatic interactions as in the case of counterions. Ligands within the same compound may be bound differently. For example, one ligand may be covalently bound and another ligand may be electrostatically bound.

Preferably, each ligand is a monoanion, examples of such ligands are dithiophosphate, dithiocarbamate, xanthate, carboxylate, thioxanthate, phosphate and hydrocarbyl, preferably alkyl, derivatives thereof. Preferably, the ratio of the number of molybdenum in the core, for example when the molybdenum-sulfur compound is a polynuclear compound, to the number of monoanionic ligands that allows the compound to be oil-soluble or oil-dispersible is a number greater than 1. : 1, for example at least 3: 2.
The oil solubility or dispersibility of a molybdenum-sulfur compound can be affected by the total number of carbon atoms present in the overall compound ligand. The total number of carbon atoms present in all hydrocarbyl groups of the ligand of the compound will typically be at least 21, for example 21 to 800, for example at least 25, at least 30 or at least 35. For example, the number of carbon atoms in each alkyl group will generally be from 1 to 100, preferably 1 to 40, and more preferably 3 to 20.

Examples of molybdenum-sulfur compounds include binuclear molybdenum-sulfur compounds and trinuclear molybdenum-sulfur compounds.
An example of a binuclear molybdenum-sulfur compound is represented by the following formula:

(Wherein, R _{1 to} R ₄ independently represent a linear, branched or aromatic hydrocarbyl group having 1 to 24 carbon atoms; X _{1 to} X ₄ independently represent an oxygen atom or Indicates a sulfur atom). The four hydrocarbyl groups, R _{1 to} R _4, may be the same or different from each other.
In a preferred embodiment, the molybdenum-sulfur compound is an oil-soluble or oil-dispersible trinuclear molybdenum-sulfur compound. Examples of trinuclear molybdenum-sulfur compounds are disclosed in WO 98/26030, WO 99/31113, WO 99/66013, EP-A-1 138 752, EP-A-1 138 686 and European Patent Application No. 02078011. And each of these is incorporated herein by reference, particularly with respect to the properties of the molybdenum compounds or additives disclosed therein.
Preferably, the molybdenum-sulfur compound has a core of the structure described in formula (I) or (II):

The core has a net charge of +4.
Preferably, the trinuclear molybdenum - sulfur compounds, wherein _{Mo 3 S k E x L n} A p Q z ( wherein, k is an integer of at least 1; E is non-metallic atom selected from oxygen and selenium X is 0 or an integer; and preferably, k + x is at least 4, more preferably 4-10, such as 4-7, most preferably 4-7; L is a molybdenum-sulfur compound And L is a monoanionic ligand; n is an integer from 1 to 4; and A is other than L when L is an anionic ligand. P may be 0 or an integer; Q is a neutral electron donating compound; and z is 0-5, including non-stoichiometric values. .

One skilled in the art will appreciate that formation of the trinuclear molybdenum-sulfur compound requires the appropriate ligand (L) and other anions (A), for example, depending on the number of sulfur and E atoms present in the core. It will be appreciated that a choice will need to be made, that is, the total anionic charge constituted by the sulfur atom, the E atom if present, the L and the A if present must be -12. The trinuclear molybdenum-sulfur compound may also include cations other than molybdenum, such as (alkyl) ammonium, amine or sodium, if the anionic charge is greater than -12.
Examples of Q include water, alcohol, amine, ether and phosphine. The electron donor compound Q is merely present to fill the empty coordination on the trinuclear molybdenum-sulfur compound.

Examples of A may be valency, for example monovalent and divalent, and include disulfides, hydroxides, alkoxides, amides and thiocyanates or derivatives thereof; preferably, A represents a disulfide ion.
Preferably, L is a monoanionic ligand such as dithiophosphate, dithiocarbamate, xanthate, carboxylate, thioxanthate, phosphate and hydrocarbyl, preferably alkyl, derivatives thereof. When n is 2 or higher, the ligands can be the same or different.
In certain embodiments, independent of other embodiments, k is 4-7, n is either 1 or 2, L is a monoanionic ligand, and p is the anionic charge at A. It is an integer that gives electrical neutrality to the base compound, and each of x and z is 0.
In a further embodiment, independently of the other embodiments, k is 4-7, L is a monoanionic ligand, n is 4, and each of p, x and z is 0. It is.

The molybdenum-sulfur core, for example, the structures represented by (I) and (II) above, may have one or more polydentate ligands, ie, functionalities capable of forming oligomers by binding to molybdenum atoms. It can be interconnected by ligands having more than one group. Molybdenum-sulfur additives containing such oligomers are included within the scope of the present invention.
Other examples of molybdenum compounds include molybdenum carboxylate and molybdenum-nitrogen complexes, both of which may be sulfurized.
The lubricant composition has a molybdenum element content derived from a molybdenum compound, preferably 1 to 1000 ppm by mass, more preferably 20 to 500 ppm by mass, for example 50 to 300 ppm by mass, based on the mass of the lubricant composition. It is.

Additive Concentrate Composition The salt of dihydrocarbyl thiophosphoric acid and molybdenum compound described in the first embodiment is present in the additive concentrate composition of the second embodiment together with one or more other co-additives. You may. For the avoidance of doubt, salts of dihydrocarbyl thiophosphoric acid and molybdenum compounds are each prepared and typically used in the form of an additive comprising a diluent fluid, for example, a lubricating oil.
Similarly, the salt of the dihydrocarbyl thiophosphate of the sixth aspect is also provided in an additive concentrate composition.

In the production of lubricant compositions, it is customary to introduce additives in the form of additive concentrate compositions containing the additives.
Additive concentrate compositions are a means of facilitating the handling of two or more additives prior to use and promoting dissolution or dispersion in the lubricant composition. When producing a lubricant composition containing two or more additives (sometimes referred to as “additive components”), the nucleus additives may be introduced separately. However, in many cases, it is convenient to introduce the additives as an additive concentrate composition comprising two or more additives (so-called additive "package" (also called "adpack")). Good.

Examples of co-additives include dispersants, detergents, rust inhibitors, antiwear agents (other than the salts of thiophosphoric acid described in the first embodiment), antioxidants, corrosion inhibitors, friction modifiers (No. Other than the molybdenum compound according to one embodiment), pour point depressants, defoamers, viscosity improvers (including multifunctional viscosity improvers, such as dispersant viscosity improvers) and surfactants.
The additive concentrate has an additive concentration based on the active ingredient of 1 to 90% by weight, for example 10 to 80% by weight, preferably 20 to 80% by weight, more preferably 20 to 70% by weight, with the balance being the balance. May be an oily carrier or diluent fluid. The final lubricant composition may typically have an additive concentrate concentration of 5 to 40% by weight.

Generally, the viscosity of the additive concentrate is higher than that of the lubricant composition. Typically, the kinematic viscosity at 100 ° C. of the additive concentrate is at least 50 mm ² s ⁻¹ (or cSt), for example 100 to 200 mm ² s ⁻¹ (or cSt), preferably 120 to 180 mm ² s ^{−. 1} (or cSt).
The amount of molybdenum element derived from the molybdenum compound according to the second embodiment in the additive concentrate composition is preferably 0.015 to 1.4% by mass based on the mass of the additive concentrate composition.
The amount of elemental phosphorus derived from the salt of thiophosphoric acid according to the second aspect in the additive concentrate composition is preferably 0.05 to 2.15% by mass based on the mass of the additive concentrate composition. is there.
Examples of diluent fluids include suitable oily, typically hydrocarbon, solvents, for example, lubricating oils selected from vegetable, animal, mineral or synthetic oils.

The preparation of the lubricant composition of the first aspect may be carried out by directly blending the salt of the thiophosphoric acid and the molybdenum compound according to the first aspect with a lubricating oil or by adding them in the form of an additive-enriched composition to a lubricating oil. It can be performed by blending with. The blending of the additives into the oil can be done before, simultaneously with, or after the addition of the other additives by any method known to those skilled in the art.
It will be appreciated that between two or more additives, an interaction may occur after introducing them into the additive concentrate composition or the lubricant composition. The interaction can occur either in the blending process or in a subsequent situation in which the composition is subjected, including the environment of use of the composition. Interactions can also occur when additional auxiliary additives are added to the composition or oil component of the present invention. Such interactions include those that change the chemical structure of the additive. Thus, for example, the compositions of the present invention include, for example, compositions in which there is an interaction between any of the additives therein, and no interactions between, for example, the components blended in the oil. A composition is included.

In the present specification,
The term "molybdenum-sulfur compound" means a compound having at least one molybdenum atom and at least one sulfur atom, preferably the compound is bonded to one or more molybdenum atoms and More preferably, the compound has at least one sulfur atom that is also bonded to one or more molybdenum atoms, and more preferably has at least one sulfur atom that is also bonded to non-molybdenum atoms, such as carbon. [Mo ₂ S ₄ ], [Mo ₃ S ₄ ] and [Mo ₃ S ₇ ]. An atom selected from oxygen or selenium may replace one or more sulfur atoms in such a core. Advantageously, the core consists only of molybdenum and sulfur atoms. Thus, the term "molybdenum-sulfur additive" means an additive that contains one or more molybdenum-sulfur compounds.

As used herein, the term "hydrocarbyl" means that the intended group is composed primarily of hydrogen and carbon atoms and is attached to the remainder of the molecule through the carbon atom, which means that the group Does not exclude the presence of other atoms or groups in an insufficient proportion to adversely affect the substantial hydrocarbon properties of the compound.
The term "comprising" means the presence of a stated feature, integer, step or component, but does not exclude the presence or addition of one or more other features, integers, step components or combinations thereof. is not. When the term "comprising" is used herein, the terms "consisting essentially of" and analogs thereof are within its scope, are preferred embodiments thereof, and therefore include the terms "consisting of" and Such analogues fall within the scope of "consisting essentially of" and are a preferred embodiment thereof.

The term "oil-soluble" or "oil-dispersible" does not mean that the compound, in all proportions, is soluble, soluble, miscible and suspendable in the oil. They mean, however, that the compounds are soluble or dispersible in oil, for example, to an extent sufficient to exert their intended effect in the environment in which the composition is used. Furthermore, the further introduction of other additives, such as those mentioned above, can affect the solubility or dispersibility of the compound.
By "major amount" is meant more than 50%, for example more than 70%, preferably 75-97%, especially 80-95 or 90% by weight of the composition.
By "small amount" is meant less than 50%, such as less than 30%, such as 3-25%, preferably 5 or 10-20% by weight of the composition.

The term "blend" refers to a mixing process at a temperature such that a suitable homogeneous composition is obtained.
The term "compound (P)" or "compound (P ')" means either a single compound that satisfies the corresponding definition, or a mixture of each compound that satisfies the corresponding definition.
All percentages stated are, unless otherwise stated, by weight based on the active ingredient, ie taking into account no carrier or diluent oil.
The present invention is illustrated by the following examples, but is not limited thereto.

Description of ZDDP ZDDP A is a zinc dialkyldithiophosphate derived from the reaction of phosphorus pentasulfide with a mixture of two monoalcohols having 4 and 8 carbon atoms. It has a phosphorus content of 8.0% by weight and a zinc content of 8.8% by weight.
ZDDP B is a zinc dialkyldithiophosphate derived from the reaction of phosphorus pentasulfide with a mixture of two monoalcohols having 4 and 5 carbon atoms. It has a phosphorus content of 8.0% by weight and a zinc content of 8.8% by weight.

ZDDP 1 is a molar ratio of phosphorus pentasulfide to 4-methyl-2-pentanol and 1,6-hexanediol of 3.7 to 0.25 (or 3.7 to 0.5, or equivalent, based on hydroxyl groups). Zinc dialkyldithiophosphate derived from reaction with the mixture on an (equivalent) basis at 3.7 vs. 0.5). The synthesis of component ZDDP # 1 involves making a dialkyldithiophosphoric acid and then reacting the acid with zinc oxide. Dialkyldithiophosphoric acid is obtained by adding finely divided phosphorus pentasulfide (446 g) to an alcohol mixture containing 1,6-hexanediol (59 g) and 4-methyl-2-pentanol (756 g) at 65 ° C. for 90 minutes. , Under constant nitrogen flow. The mixture was then kept at 85 ° C. for a further 120 minutes before cooling the resulting product. A portion of the dialkyldithiophosphoric acid (250 g) was added over 30 minutes to the well-mixed zinc oxide oil slurry (289 g, 50% strength) at ambient temperature. The temperature rose to about 45 ° C. due to the exothermic reaction. Thereafter, the remaining dialkyldithiophosphoric acid (750 g) was added over 75 minutes. The reaction temperature rose to 85 ° C. in 20 minutes and was held at that temperature for a further 75 minutes. The resulting water by-product was removed at 85 ° C. under reduced pressure and filtered to give a viscous liquid product. ZDDP # 1 had a phosphorus content of 8.4% by mass and a zinc content of 9.0% by mass.

ZDDP # 2 is a molar ratio of phosphorus pentasulfide to 3.7-0.25 of 4-methyl-2-pentanol and dipropylene glycol (or 3.7 to 0.5 on a hydroxyl group basis, or 3 on an equivalent weight basis). .7 vs. 0.5) derived from the reaction with the mixture. The synthesis of component ZDDP # 2 is similar to that of ZDDP # 1, except that the alcohol mixture during the preparation of the dialkyldithiophosphoric acid contains dipropylene glycol (67 g) and 4-methyl-2-pentanol (756 g). The obtained acid (1000 g) was neutralized with a zinc oxide oil slurry (283 g, 50% concentration). ZDDP # 2 had a phosphorus content of 7.8% by mass and a zinc content of 8.5% by mass.

Description of Lubricating Compositions Lubricating compositions comprising conventional additives, ZDDP components and optionally molybdenum compounds were prepared by methods known in the art (see Table 1 for details).

Oils 7 and 8 are compositions of the present invention, while Oils 1 and 6 are compositions for comparison. Each oil was blended to a phosphorus content of 500 ppm and contained the same conventional additives in the same proportions. The molybdenum component, if present, is a trinuclear molybdenum dithiocarbamate, which is the method described in Example 1 of WO 99/31113, but without the use of toluene, without a filtration step, and It was manufactured by a method of heating to about 160 ° C. for 4 hours.

Test oils 1-8 were tested in a high frequency reciprocating rig (HFRR) for 60 minute friction performance at 140 ° C (see Table 2). The HFRR provides information on boundary friction, and the rig is based on the title "The Influence of Engine Oils on Friction Reduction" by CH Bovington, at the 12th International Colloquium, January 2000: Tribology 2000 Plus, volume 1, page 393, Technische Akademie Esslingen. The average coefficient of friction by HFRR gives an index of the performance of the oil, which is interpreted as improved fuel economy in the engine.

Table 2 shows that oils 1 to 4 containing no molybdenum component exhibit comparative friction performance. Furthermore, Oils 5 and 6 containing molybdenum components also show performance comparable to Oils 1-4. In contrast, the friction performance of the oils 7 and 8 containing the ZDDP component and the molybdenum component according to the present invention is better than the oils containing the ZDDP component and A and B (oils 5 and 6 respectively) and the oils without the molybdenum component (oils). Excellent friction performance (i.e., a low friction coefficient) was shown as compared with 1) to 4).
Oils 5 and 8 were also tested in a traction rig, thereby obtaining data points for plotting a Stribeck Curve. The rig is described in the title "The Influence of Engine Oils on Friction Reduction" by CH Bovington at the 12th International Colloquium, January 2000: Tribology 2000 Plus, volume 1, page 393, Technische Akademie Esslingen. The traction coefficient was measured at 135 ° C. and was performed on fresh oil and oil treated at 135 ° C. to determine the hydroelastic “mixing” and entrainment speed under full film conditions. Obtained as a function. The test is considered to show the retention properties of the composition.

Table 3 shows the area under the Stribeck curve for each oil sample; smaller areas indicate better performance. It is evident from the data that the oil 8 according to the invention comprising a ZDDP component and a molybdenum component has higher performance and can retain its performance over a long period of time. In fact, the performance of the oil 8 after 6 hours of treatment is comparable to that of the oil 5 at the start of the test, ie before the treatment.

Claims (20)

A lubricating oil composition comprising a large amount of a lubricating viscosity oil and a small amount of the following (A) and (B) added to or mixed with it:
(A) Oil-soluble or oil-dispersible salts of dihydrocarbylthiophosphoric acids derivable by the reaction of phosphorus sulfide with the following (I) or (II):
(I) A compound (P) having at least two groups independently selected from hydroxyl (OH) and sulfhydryl (SH), and separating two groups, preferably any two groups, in the compound (P) And (II) two or more compounds including the compound (P) described in (I), and at least four, preferably at least five, atoms, and hydroxyl (OH) or sulfhydryl (SH) A mixture with one or more compounds having at least one group selected; and (B) an oil-soluble or oil-dispersible molybdenum compound. The dihydrocarbyl thiophosphoric acid is derivatizable by reacting phosphorus sulfide with a mixture of two or more compounds according to claim 1, wherein the mixture is selected from hydroxyl (OH) or sulfhydryl (SH). The lubricant composition according to claim 1, comprising a compound (M) having one group and the compound (P) according to claim 1. The amount of compound (P) present in the mixture, based on hydroxyl (OH) and sulfhydryl (SH) groups, can be up to 50 mol% based on total hydroxyl (OH) and sulfhydryl (SH) groups in the mixture. The lubricant composition according to claim 1 or 2. (4) The lubricant composition according to any one of (1) to (3), wherein the compound (P) contains at least two hydroxyl groups. The lubricant composition according to any one of claims 1 to 4, wherein the compound (P) has at least six atoms separating two groups, preferably any two groups. The lubricant composition according to any one of claims 1 to 5, wherein at least one of the atoms separating the two groups, preferably any two groups, in the compound (P) is selected from oxygen, sulfur and nitrogen. . 潤滑 The lubricant composition according to any one of claims 2 to 6, wherein the compound (M) is an aliphatic monoalcohol. The lubricant composition according to any one of claims 1 to 7, wherein the compound (P) is derived from a reaction between a glycol and an alkylene oxide. The lubricant composition according to any one of claims 1 to 8, wherein the dihydrocarbyl thiophosphoric acid is an amine salt, an ammonium salt, or a salt of a metal selected from alkali metals, alkaline earth metals, and transition metals. The lubricating composition according to any one of claims 1 to 9, wherein the molybdenum compound is a trinuclear molybdenum compound. The lubricant composition according to any one of claims 1 to 10, wherein the phosphorus content of the lubricant composition is at most 0.15% by mass based on the mass of the lubricant composition. An additive concentrate composition suitable for preparing a lubricant composition comprising (A) and (B) according to claim 1, which is added to or mixed with a diluent fluid. The lubricant composition of claim 1, for improving the frictional properties of the lubricant composition or improving fuel economy and / or fuel economy retention of an engine lubricated with the lubricant composition. Use of (A) and (B) described in (1). A method for producing the lubricant composition according to any one of claims 1 to 11, wherein a large amount of the lubricating viscosity oil and a small amount of the additive-enriched composition or the small amount of the additive concentrate according to claim 12. A method comprising blending (A) and (B) according to 1 above. A method for lubricating a surface, comprising applying a lubricant composition according to any one of claims 1 to 11 or a lubricant composition produced by the method according to claim 14 to the surface. Including methods. Oil-soluble or oil-dispersible salts of dihydrocarbylthiophosphoric acids derivable by the reaction of phosphorus sulfide with (I) or (II):
(I) A compound (P ′) having at least two groups independently selected from hydroxyl (OH) and sulfhydryl (SH), and two groups in the compound (P ′), preferably two arbitrary groups Is present, and at least one of the atoms separating two groups, preferably any two, in compound (P ') is oxygen, sulfur or nitrogen Or (II) two or more compounds including the compound (P ') according to (I) and one or two compounds having at least one group selected from hydroxyl (OH) or sulfhydryl (SH). Mixtures of the above compounds. An additive comprising the oil-soluble or oil-dispersible salt of claim 16, and optionally a diluent fluid. 18. An additive concentrate composition comprising a diluent fluid and an additive according to claim 17 added or mixed therewith and one or more co-additives. A lubricant composition comprising a large amount of lubricating viscosity oil and a small amount of the additive concentrate according to claim 18 or a small amount added to or mixed with the oil. Dihydrocarbylthiophosphoric acid derivable by reaction of phosphorus sulfide with (I) or (II) below:
(I) A compound (P ′) having at least two groups independently selected from hydroxyl (OH) and sulfhydryl (SH), and two groups in the compound (P ′), preferably two arbitrary groups Is present, and at least one of the atoms separating two groups, preferably any two, in compound (P ') is oxygen, sulfur or nitrogen Or (II) two or more compounds including the compound (P ') according to (I) and one or two compounds having at least one group selected from hydroxyl (OH) or sulfhydryl (SH). Mixtures of the above compounds.