JP5739525B2 - Lubricant composition for automobile transmission - Google Patents

Description

  The present invention relates to a lubricant composition, in particular a lubricant composition for an automobile transmission, more particularly a lubricant composition for a manual gearbox.

  Automotive transmission parts operate at high speeds and under large loads. Therefore, transmission oils must protect the parts against wear and fatigue, in particular the gear teeth against the flaking phenomenon.

  Flaking occurs after long-term use, but degradation occurs further after the occurrence of flaking. Although the mechanism of flaking is not well known, it begins when a crack occurs at a certain depth from the surface, and such a crack grows. Then, when a normal crack is formed on the surface, suddenly flaking occurs.

  In order to prevent this phenomenon, it is necessary to reduce the contact stress by appropriately selecting the shape of the component or by reducing friction while preventing adhesion. Lubricants are involved in such prevention processes mainly by the physicochemical reactions of various additives formulated in themselves.

  In general, sulfur-based, phosphorus-based, phosphorus-sulfur-based, or borate-based antiwear / extreme pressure agents are added to transmission oils in order to impart protective properties against flaking. It should be noted that other additives in the lubricant are considered to have some influence on the growth of cracks inside the part, that is, the flaking phenomenon, for better or worse.

  In the case of a manual gearbox, the presence of a synchronizer creates additional stress. In fact, synchronizer cone and ring devices require detailed control over the friction between the cone and ring. The friction between the cone and the ring must be sufficient to synchronize the gear. At the same time, the cone-ring engagement must be releasable so that the synchronizer does not block.

  Cone and ring devices also wear when the friction level does not match the part shape.

  The friction level can be adjusted by adding a friction modifier to the gearbox oil.

  In this way, the antiwear / extreme pressure agent and the friction modifier can be blended into the manual gearbox oil. These additives can affect both the friction level and the flaking phenomenon by acting on the surface of the part.

  To formulate manual gearbox oil that provides high protection against flaking, prevents synchronizer wear and blocking, and allows easy gear changes, friction modifiers and anti-wear / extreme pressure It is necessary to select the agents, and to adjust their specific addition amounts.

  In order to improve the wear resistance of the lubricant composition (oil), an organomolybdenum friction modifier and an organophosphorus and / or organosulfur and / or organophosphorus-sulfur antiwear / extreme pressure A method of blending an agent with a lubricant composition is known.

  Patent Document 1 discloses a lubricant composition comprising a molybdenum complex, a thiadiazole compound, and optionally a phosphorodithioate. This molybdenum complex is prepared by reaction of 1 mole of oil (glyceride or fatty acid), 1 to 2.5 moles of diethanolamine, and a molybdenum source in an amount of 0.1 to 12% by weight of molybdenum in the complex. Is done. However, Patent Document 1 does not describe a specific example in which the mass content of molybdenum is 90 to 350 ppm for a composition containing molybdenum, sulfur, and phosphorus.

  Patent Document 2 discloses an internal combustion engine lubricant containing a molybdenum complex and an organic sulfur compound. This molybdenum complex is prepared by reaction of 1 mole of oil (glyceride or fatty acid), 1 to 2.5 moles of diethanolamine, and a molybdenum source in an amount of 0.1 to 12% by weight of molybdenum in the complex. Is done. The organosulfur compound is selected from dimercaptothiadiazole, bisdithiocarbamate, dithiocarbamate and phosphorodithioate.

  However, Patent Document 2 does not specify a specific combination of the molybdenum complex and one or more organic sulfur compounds, and does not specify the amount of Mo contained in the lubricant composition. . On the other hand, the Examples describe that the amount of the complex in the lubricant is 0.5 to 1.5% by weight, that is, the Mo content in the lubricant is 5 to 1,800 ppm. ing. In prescribing the gearbox lubricant, the Mo content is not appropriate if it is too much or too little. In fact, this can cause synchronizer flaking and blocking problems. The same is true for the selection of sulfur-containing additives and / or phosphorus-containing sulfur additives, and their specific addition amounts.

  Patent Document 3 discloses a lubricant composition containing an organomolybdenum compound and an antiwear agent. The organomolybdenum compound is selected from molybdenum dithiophosphate and molybdenum dithiocarbamate. The antiwear agent may be dimercaptothiadiazole. However, Patent Document 3 does not disclose a specific content of molybdenum when thiazole is used as an antiwear / extreme pressure agent.

  Also, molybdenum dithiophosphate and molybdenum dithiocarbamate can exacerbate synchronizer wear and / or blocking problems and, in some cases, flaking problems.

  However, compositions based on molybdenum and / or sulfur and / or phosphorus in the prior art relate to the field of antioxidants and antiwear agents, which are mainly formulated in internal combustion engine oils.

  In addition, the prior art composition provides a specific content of Mo element in the presence of a sufficient amount of sulfur and phosphorus in terms of protecting the synchronizer from flaking and wear and at the same time sufficiently preventing the synchronizer from blocking. Not revealed. Thus, the prior art compositions are not suitable for lubricating automotive gearboxes (particularly manual gearboxes).

  Among known manual gearbox oils, boron-containing oils (oils) achieve an excellent balance between the various properties described above. Boron-containing oils are formulated without any use of sulfur compounds, phosphorus compounds, and phosphorus-sulfur compounds. Current technology based on sulfur-containing additives, phosphorus-containing additives, and phosphorus-containing sulfur-additives cannot achieve the performance levels obtained with borates with respect to protection of synchronizers against flaking and wear.

  However, the use of borates is not desirable, despite the excellent extreme pressure performance and numerous advantages described above, because water can be mixed into the lubricant. In fact, inorganic borates are partially soluble in water, so the structure changes as the amount of water in the molecule increases. When a large amount of water is contained in the solvent, the borate structure may change and crystallize due to the large amount of water, and an edged crystal having a size exceeding 100 nm may be formed. In such cases, the borate may block the gearbox synchronization system.

  Therefore, if boron-containing oil is used, it is necessary to adopt a special design structure in which a manual gearbox is provided with a waterproof system, which leads to complexity and cost, and should be avoided if possible.

US Pat. No. 6,806,241 European Patent Application No. 0874040 International Publication No. 2005/035700 Pamphlet

  Therefore, it is an oil for automobile gearboxes (especially manual gearboxes) that protects gear teeth from flaking, limits synchronizer wear and prevents synchronizer blocking, and makes gear changes easy An automotive gearbox oil is desired that can be carried out easily and is not sensitive to water (ie, contains no borate or low borate content).

  An object of the present invention is to provide a lubricant composition in which an ester amide molybdenum complex is combined with a sulfur-containing extreme pressure agent and a phosphorus-containing extreme pressure agent and / or a phosphorus-containing-sulfur extreme pressure agent. Another object of the present invention is the use of the lubricating composition for lubricating gearboxes, in particular automobile gearboxes. Particularly effective is the use for an automobile manual gearbox.

The purpose of the present invention is to
(A) an organic molybdenum compound;
(B) one or more antiwear / extreme pressure agents selected from thia (di) azoles;
(C) one or more phosphorus-containing antiwear / extreme pressure agents and / or phosphorus-sulfur antiwear / extreme pressure agents selected from phosphites, phosphates, phosphonates, thiophosphates and thiophosphites;
And a molybdenum composition having a molybdenum mass content of 90 to 350 ppm.

  Preferably, the lubricant composition according to the present invention has a molybdenum mass content of 100 to 200 ppm, more preferably 140 to 180 ppm.

  Preferably, the lubricant composition according to the present invention has a phosphorus mass content of 500 to 700 ppm, more preferably 520 to 650 ppm.

  In one embodiment, the lubricant composition according to the present invention comprises at least one thiophosphate, preferably at least one dithiophosphate, more preferably at least one amine as the antiwear / extreme pressure agent (c). Contains dithiophosphate.

  In a preferred embodiment, the lubricant composition according to the present invention comprises at least one thiadiazole, more preferably at least one dimercaptothiadiazole, as the antiwear / extreme pressure agent (b).

  The lubricant composition according to the present invention may contain 0.35 to 1% by mass of thiazole, preferably 0.35 to 1% by mass of dimercaptothiadiazole.

In a preferred embodiment, the lubricant composition according to the present invention contains at least one organic molybdenum complex as the organic molybdenum compound (a),
The organic molybdenum complex is
(I) mono-, di- or tri-glyceride or fatty acid oils;
(Ii) an amine source represented by the following formula (I);

（式中、Ｘ１およびＸ２はＯまたはＮであり、Ｘ１がＯであればｎは１であり、Ｘ２がＯであればｍは１であり、Ｘ１がＮであればｎは２であり、Ｘ２がＮであればｍは２である。）

Wherein X1 and X2 are O or N, n is 1 if X1 is O, m is 1 if X2 is O, n is 2 if X1 is N, (If X2 is N, m is 2.)

(Iii) a molybdenum source selected from molybdenum trioxide and molybdate (more preferably ammonium = molybdate) in an amount such that the molybdenum in the organomolybdenum complex is 0.1 to 20.0% by weight;
It was obtained by the reaction of

  Preferably, the amine source (ii) is diethanolamine or 2- (2-aminoethyl) aminoethanol.

  Preferably, the fat (i) is a mono-, di- or tri-glyceride of a fatty acid having 4 to 28 carbon atoms (more preferably a mono-, di- or tri-glyceride of a fatty acid having 8 to 18 carbon atoms). Or a fatty acid having 4 to 28 carbon atoms (more preferably a fatty acid having 8 to 18 carbon atoms).

In a preferred embodiment, the organomolybdenum complex (a) is
At least one compound (a1) represented by the following formula (II), and at least one compound (a2) represented by the following formula (III):
Among them, (a1) alone, (a2) alone, or a mixture of (a1) and (a2) is included.

  Wherein X1 and X2 are O or N, n is 1 if X1 is O, m is 1 if X2 is O, n is 2 if X1 is N, When X2 is N, m is 2, and R1 and R2 are aliphatic hydrocarbon chains having 3 to 27 carbon atoms, preferably aliphatic hydrocarbon chains having 7 to 17 carbon atoms.)

  In a more preferred embodiment, the organomolybdenum complex (a) includes at least one compound represented by the following formula (IV).

  (In the formula, R1 is an aliphatic hydrocarbon chain having 3 to 27 carbon atoms, preferably an aliphatic hydrocarbon chain having 7 to 27 carbon atoms.)

  In another preferred embodiment, the organomolybdenum complex (a) includes at least one compound represented by the following formula (V).

  (In the formula, R1 is an aliphatic hydrocarbon chain having 3 to 27 carbon atoms, preferably an aliphatic hydrocarbon chain having 7 to 27 carbon atoms.)

  The invention further relates to the use of the above-described lubricant composition for lubricating gearboxes, in particular automobile gearboxes.

  In a preferred embodiment, the present invention relates to the use of the above-described lubricant composition for lubricating a manual gearbox, in particular a motor vehicle manual gearbox.

[Organic molybdenum compound]:
The lubricant composition according to the present invention may contain any organic molybdenum compound as long as it is soluble in oil. Examples of such organic molybdenum compounds include, but are not necessarily limited to, molybdenum dithiophosphate, molybdenum dithiocarbamate, and various organic molybdenum complexes such as molybdenum carboxylate, molybdenum ester, molybdenum amide, and the like. The organomolybdenum complex is obtained, for example, by a reaction of molybdenum oxide or ammonium = molybdate with an oil, fat, glyceride, fatty acid or fatty acid derivative (ester, amine, amide, etc.).

  Preferably, the lubricant composition according to the present invention includes a molybdenum complex having an amide-based ligand that does not have any phosphorus and sulfur. Such a molybdenum complex mainly includes a molybdenum source (for example, molybdenum trioxide), an amine or a derivative thereof, a fatty acid [for example, a fatty acid having 4 to 28 carbon atoms, preferably a fatty acid having 8 to 18 carbon atoms ( For example, it can be prepared by reaction with a fatty acid contained in vegetable oil or animal oil) or the like] or a derivative thereof.

  The synthesis of such compounds is described in, for example, US Pat. No. 4,888,647, European Patent No. 0546357, US Pat. No. 5,412,130, European Patent No. 1,770,153, and the like.

The organic molybdenum complex is
(I) mono-, di- or tri-glyceride or fatty acid oils;
(Ii) an amine source represented by the following formula (I);

Wherein X1 and X2 are O or N, n is 1 if X1 is O, m is 1 if X2 is O, n is 2 if X1 is N, (If X2 is N, m is 2.)
(Iii) a molybdenum source selected from molybdenum trioxide and molybdate (preferably ammonium = molybdate) in an amount such that the molybdenum in the organomolybdenum complex is 0.1-20.0% by weight;
It may be obtained by the reaction of

  Generally, the molybdenum in the organomolybdenum complex is 7 to 8.5% by weight.

In particular, in one embodiment, the organomolybdenum compound in the composition according to the present invention comprises:
At least one compound (a1) represented by the following formula (II), and at least one compound (a2) represented by the following formula (III):
Among them, (a1) alone, (a2) alone, or a mixture of (a1) and (a2) is included.

  Wherein X1 and X2 are O or N, n is 1 if X1 is O, m is 1 if X2 is O, n is 2 if X1 is N, When X2 is N, m is 2, and R1 and R2 are aliphatic hydrocarbon chains having 3 to 27 carbon atoms, preferably aliphatic hydrocarbon chains having 7 to 17 carbon atoms.)

In one embodiment, the organomolybdenum complex in the composition according to the invention is
(I) mono-, di- or tri-glyceride or fatty acid oils;
(Ii) diethanolamine or 2- (2-aminoethyl) aminoethanol;
(Iii) a molybdenum source selected from molybdenum trioxide and molybdate (preferably ammonium = molybdate) in an amount such that the molybdenum in the organomolybdenum complex is 0.1-20.0% by weight;
It was prepared by the reaction of

In particular, in one embodiment, the organomolybdenum compound in the composition according to the present invention comprises:
At least one compound (a1 ′) represented by the following formula (IV), and at least one compound (a2 ′) represented by the following formula (V):
Among them, (a1 ′) alone, (a2 ′) alone, or a mixture of (a1 ′) and (a2 ′) is included.

  (In the formula, R1 is an aliphatic hydrocarbon chain having 3 to 27 carbon atoms, preferably an aliphatic hydrocarbon chain having 7 to 27 carbon atoms.)

  The content of the organic molybdenum compound in the composition according to the present invention is adjusted so that the mass content of molybdenum in the composition is 90 to 350 ppm, preferably 100 to 200 ppm, more preferably 140 to 180 ppm. Yes.

  Too little molybdenum content can cause synchronizer blocking problems and potential wear of the synchronizer cone and ring device.

  If the molybdenum content is too high, flaking worsens.

[Thia (di) azole]:
Thia (di) azole is a five-membered ring compound having both sulfur and nitrogen atoms. For example, benzothiazole refers to a specific type of thia (di) azole. In this specification, the term “thia (di) azole” refers to a cyclic compound having one sulfur atom and one nitrogen atom in a five-membered ring, and one sulfur atom in a five-membered ring. Also included are thiadiazoles having two nitrogen atoms.

  The thia (di) azole may not be substituted or may be substituted with a hydrocarbon compound so as to increase the solubility in oil.

  In one embodiment, the thia (di) azole in the lubricant composition according to the present invention is unsubstituted benzothiazole, unsubstituted thiazole, unsubstituted thiadiazole.

  In a preferred embodiment, the thia (di) azole in the composition according to the invention is a dimercaptothiadiazole, such as 2,5-dimercapto-1,3,4-thiadiazole, 3,5-dimercapto-1,2 , 4-thiadiazole, 3,4-dimercapto-1,2,4-thiadiazole, 4,5-dimercapto-1,2,3-thiadiazole, 3-methylmercapto-1,2,4-thiadiazole, 5-mercapto- 1,2,4-thiadiazole.

  In addition, the compound mentioned above may be used individually or as a mixture.

  Typically, thia (di) azole represents 0.35 to 1% by weight in the composition according to the invention.

  Preferably, the composition according to the present invention comprises 0.35 to 1% by mass of dimercaptothiazole, more preferably 0.35 to 0.45% by mass.

[Phosphorus-containing compound or phosphorus-containing sulfur compound]:
The phosphorus-containing compound in the lubricant composition according to the present invention is an antiwear / extreme pressure agent such as phosphate, phosphite and phosphonate. The term “phosphate” refers to phosphoric acid, mono-, di- and tri-esters of phosphoric acid (eg, alkyl phosphates, etc.), and salts of phosphoric acid (eg, amine phosphates, etc.). The term “phosphite” refers to phosphorous acid, mono-, di- and tri-esters of phosphorous acid (such as alkyl phosphites), and salts of phosphorous acid (such as amine phosphites). Point to. The term “phosphonate” refers to phosphonic acids, mono-, di- and tri-esters of phosphonic acids (eg, alkyl phosphonates, etc.), and salts of phosphonic acids (eg, amine phosphonates, etc.). The phosphorus-sulfur antiwear / extreme pressure agent used in the present invention is (mono or di) thiophosphate and / or (mono or di) thiophosphite. The term “thiophosphate” includes thiophosphoric acid, esters of thiophosphoric acid, salts of thiophosphoric acid, and dithiophosphate. The term “thiophosphite” includes thiophosphorous acid, esters of thiophosphorous acid, salts of thiophosphorous acid, and dithiophosphite.

  In a preferred embodiment, the phosphorus-sulfur antiwear / extreme pressure agent in the composition according to the present invention is a thiophosphate represented by the following formula (VI).

  [Wherein X3 and X4 are independently of each other S or O; at least one of X3 and X4 is S; R3 and R4 are hydrogen or an alkyl group having 1 to 22 carbon atoms; Table IIA, Group III, Group VA, Group VIA, Group IB, Group VIB, Group VIII metals where n is the valence of the metal or M is the formula : (R5) (R6) (R7) Primary amine, secondary amine or tertiary amine represented by N (wherein R5, R6 and R7 are hydrogen or an alkyl group having 1 to 18 carbon atoms. ) Derived from n). ]

  More preferred compounds are dithiophosphates (ie, X3 and X4 in the above formula (VI) are sulfur), and further preferred compounds are zinc dithiophosphates or amine dithiophosphates. Among them, amine dithiophosphate is preferable.

Sulfur-phosphorus antiwear / extreme pressure agents such as monobutyl thiophosphate, monooctyl thiophosphate, monolauryl thiophosphate, dibutyl thiophosphate, dilauryl thiophosphate, tributyl thiophosphate, trioctyl thiophosphate, triphenyl Thiophosphate, trilauryl thiophosphate, monobutyl thiophosphite, monooctyl thiophosphite, monolauryl thiophosphite, dibutyl thiophosphite, dilauryl thiophosphite, tributyl thiophosphite, trioctyl thiophosphite, triphenyl Examples include thiophosphite, trilauryl thiophosphite, and salts thereof.
Examples of thiophosphoric acid esters and thiophosphorous acid esters include those obtained by reacting nitrogen-containing compounds such as ammonia or amines, or zinc oxide or zinc chloride.

  Preferably, the amount of each additive is adjusted so that the mass content of phosphorus in the oil according to the present invention is 500 to 700 ppm, more preferably 520 to 650 ppm.

  If there is too little content of elements (sulfur and phosphorus) of antiwear and extreme pressure, the problem of flaking occurs.

  In addition, if there is too much content of elements of wear resistance / extreme pressure [and content of friction modifier (including organomolybdenum compound)], gear change will be adversely affected: the coefficient of friction of the cone ring will be low After that, gear synchronization, that is, gear change becomes difficult.

  Furthermore, in consideration of the environment, it is desirable to suppress the sulfur content and phosphorus content in the lubricant composition to the required amounts.

  By the combined action of the above-described configuration and the molybdenum content in the lubricant according to the present invention, it is possible to impart good anti-flaking properties, and good wear resistance and anti-blocking properties to the synchronizer. it can.

  That is, whether or not these three characteristics can be achieved efficiently and efficiently depends on the specific amount of the friction modifier and the antiwear / extreme pressure agent, that is, the element Mo derived from these additives (compounds). , S and P content.

[Base oil (base material)]:
The composition according to the invention may comprise any kind of animal and / or vegetable and / or synthetic and / or natural mineral oil as lubricant base oil, depending on the occasional application.

  As the at least one base oil in the composition according to the present invention, a group I to V mineral-derived or synthetic-derived oil [or equivalent in the ATIEL classification] specified in the API classification shown in the following table is used alone. Alternatively, a mixture may be used.

  The mineral-derived base oil according to the present invention is processed by subjecting the crude oil to atmospheric distillation or vacuum distillation, followed by a purification step (for example, solvent extraction, deasphalting, solvent dewaxing, hydrogenation, hydrocracking / hydrogenation). All types of base oils obtained by subjecting to isomerization, hydrofinishing, etc.) are included.

  The base oil in the composition according to the present invention may be a synthetic oil (for example, a specific ester of a carboxylic acid and an alcohol, a poly α-olefin, or the like). The poly-alpha olefin used as the base oil is obtained from, for example, a monomer having 4 to 32 carbon atoms (for example, octane, decene, etc.) and has a viscosity at 100 ° C. of 1.5 to 15 cSt. Is. Typically, the polyalphaolefin has a weight average molecular weight of 250 to 3,000. A mixture of synthetic oil and mineral oil may be used.

  In preparing the composition according to the present invention, various properties (particularly viscosity, viscosity index, sulfur, etc.) suitable for use in gearboxes (especially automobile gearboxes, more particularly manual gearboxes) are used. The use of such a lubricant base oil is not particularly limited as long as it can provide a component, oxidation resistance, and the like.

  Preferably, the lubricant base oil comprises at least 50% by weight, more preferably at least 60% by weight, and even more preferably at least 70% by weight in the lubricant composition according to the present invention. Typically, the lubricant base oil accounts for 75-90% by weight in the composition according to the invention.

  Preferably, the lubricant composition according to the present invention comprises a base oil derived from Group I and / or Group III minerals in the API classification, or a base oil derived from Group IV synthesis.

[Other additives]:
The lubricant composition according to the present invention may further contain all kinds of additives depending on the occasional use. Examples of such additives include amine-based or phenol-based antioxidants (for example, diphenylamine, phenol in which at least one ortho position is substituted with an alkyl group), detergents (for example, sulfonate), and the like. It is done.

  Preferably, an additive that improves the viscosity index (VI improver) is 5 to provide viscosity characteristics suitable for use in gearboxes (especially automotive gearboxes, preferably manual gearboxes). 25% by mass is blended. Examples of the VI improver include polymethacrylate (PMA), polyisobutene (PIB), and fatty acid ester.

[Example]:
Regarding the prepared lubricant composition, Table 1 to be described later shows the mass composition and the performance related to wear of the synchronizer, blocking of the synchronizer, flaking and the like.

(Flaking test)
The flaking test was performed under the following conditions.
BCFP Sermes bench: bench oil with Renault gearbox JR5-125, differential 14x63 secondary shaft 8200280045 and 1 pair of rings 8200280134, 28x37 primary shaft 8200107846 and 3 pairs of 3-speed idler pinion 7700114048 : 2.3 liters of oil, oil temperature 110 ° C
Input torque: 148mN
Main speed: 3,000rpm
Test time: 142 times 3 times (changes primary shaft, 3-speed idler pinion and roller bearing every 142 hours)
Flaking evaluation:
After 426 hours, the final score of the pinion / differential ring pair is evaluated, and every 142 hours, a corresponding pair of 3 pairs of 28x37 primary shaft / 3 speed idler pinions is evaluated. A pass (sufficient score) or a fail (excessive flaking surface) is determined based on the score result of the part.

(Synchronizer blocking test)
A synchronizer blocking test was performed using a pair of cone rings under the following conditions (SYNC-40 procedure).
54mm brass threaded ring (eg model number 7700 708 152, 7700 869 430, etc.) and gearbox JXX idler pinion blasted and polished carbonitrided steel cone (eg model number 7700 867 612, 7700 740 880 etc.)
Oil: 250 ml of oil, oil level between pinion and ring Adapter SAE / 2 for synchronizer of test machine SAE2 / A
I = 0.155m ² / kg
N = 300rpm
F = 60daN
T = 6 seconds (continuous time between two consecutive braking operations)
n = 10,125 gear change cycles (21 hours)

  Of the 10,125 gear change cycles, find the number of cycles where the counter-torque required to disengage the cone and ring exceeds 2 mN. If this number of cycles is less than 100, perform the blocking test of the synchronizer. Pass.

(Synchronizer wear resistance test)
Under the following conditions (SYNC-13 procedure, SAE 2-A procedure), the abrasion resistance test of the synchronizer was performed using a pair of cone rings.
54mm brass threaded ring (eg model number 7700 708 152, 7700 869 430, etc.) and gearbox JXX idler pinion blasted and polished carbonitrided steel cone (eg model number 7700 867 612, 7700 740 880 etc.)
Oil: 125 ml of oil, oil level is the lower part of the ring Adapter SAE / 2 for the synchronizer of the test machine SAE2 / A
I = 0.155m ² / kg
N = 600rpm
F = 60daN
T = 3.5 seconds (continuous time between two consecutive braking operations)
n = 20,000 gear change cycles (20 hours)

  At the end of the 20,000 cycles, the axial wear of the synchronizer ring / gear cone pair is measured in mm. If it is lower than about 0.30 mm, it is acceptable (passed). If the wear is less than 0.15 mm, it can be said that the performance is excellent. If the wear exceeds 1 mm, it is disqualified (monitoring / compensation required).

[Discussion]:
Oils A and B in the table below are oils according to the present invention. Oils C and D in the following table are boron-containing oils that are sensitive to water.
Oils A and B show performance levels comparable to boron-containing oils with respect to synchronizer wear, and pass the blocking and flaking tests as well.

  Oil E in the following table contains the same antiwear / extreme pressure agent as oil A, and further contains a phosphite / phosphate phosphorus-containing compound. However, Oil E does not contain any molybdenum-based friction modifier. The wear of the synchronizer in the case of oil E is at an unacceptable level (0.84 mm).

  Oils F, G and H in the table below contain the same sulfur-containing antiwear / extreme pressure agent and phosphorus-sulfur antiwear / extreme pressure agent as the oil according to the present invention, but are not molybdenum based friction modifiers. The point of inclusion differs from the oil according to the present invention. The wear of the synchronizer in the case of oils F, G and H is very significant.

  Oils I and L in the table below contain the same sulfur-containing antiwear / extreme pressure agent and phosphorus-sulfur antiwear / extreme pressure agent as the oil according to the present invention, and are esteramide type molybdenum-based friction modifiers. Contains agents. However, the mass content of Mo in the oil I is 400 ppm, and the oil I fails the flaking test.

  The mass content of Mo in the oil L is 80 ppm, and the oil L fails in the blocking test of the synchronizer.

  The oil J in the table described below contains the same sulfur-containing antiwear / extreme pressure agent and phosphorus-sulfur antiwear / extreme pressure agent as the oil according to the present invention, but does not contain any molybdenum. Different from oil. Oil J contains a fatty acid monoester as a friction modifier. Oil J fails the synchronizer blocking test.

  The oil K in the table described below contains the same sulfur-containing antiwear / extreme pressure agent and phosphorus-sulfur-containing antiwear / extreme pressure agent as the oil according to the present invention, but does not contain molybdenum at all. Different from oil. Furthermore, oil K does not contain any friction modifier. Oil K fails the synchronizer blocking test.

  Oils M and N in the following table do not contain any thiazole as a sulfur-containing compound. Oil M further does not contain any molybdenum. Oils M and N left very undesirable results in the flaking test. Oils M and N do not contain any dimercaptothiadiazole.

Claims (14)

A lubricant composition for lubricating a manual gearbox ,
(A) an organic molybdenum compound;
(B) one or more antiwear / extreme pressure agents selected from thia (di) azoles;
(C) one or more phosphorus-containing antiwear / extreme pressure agents and / or phosphorus-sulfur antiwear / extreme pressure agents selected from phosphites, phosphates, phosphonates, thiophosphates and thiophosphites;
And a lubricant content in which the molybdenum content in the lubricant composition is 90 to 180 ppm.   The lubricant composition according to claim 1, wherein the mass content of molybdenum in the lubricant composition is 140 to 180 ppm.   The lubricant composition according to claim 1 or 2, wherein a mass content of phosphorus in the lubricant composition is 500 to 700 ppm.   The lubricant composition according to any one of claims 1 to 3, comprising at least one thiophosphate or at least one dithiophosphate as the antiwear / extreme pressure agent (c). .   The lubricant composition according to any one of claims 1 to 4, comprising at least one thiadiazole as the antiwear / extreme pressure agent (b).   The lubricant composition according to claim 5, comprising at least one dimercaptothiadiazole as the antiwear / extreme pressure agent (b).   The lubricant composition according to any one of claims 1 to 6, wherein the lubricant composition contains 0.35 to 1% by mass of thia (di) azole.   The lubricant composition according to claim 7, comprising 0.35 to 1% by mass of dimercaptothiadiazole. The lubricant composition according to any one of claims 1 to 8, wherein the organic molybdenum compound (a) includes at least one organic molybdenum complex,
The organic molybdenum complex is
(I) mono-, di- or tri-glyceride or fatty acid oils;
(Ii) an amine source represented by the following formula (I);

Wherein X1 and X2 are O or N, n is 1 if X1 is O, m is 1 if X2 is O, n is 2 if X1 is N, (If X2 is N, m is 2.)
(Iii) a molybdenum source selected from molybdenum trioxide and molybdate in an amount such that the molybdenum in the organomolybdenum complex is 0.1 to 20.0% by weight;
A lubricant composition obtained by the reaction of   The lubricant composition according to claim 9, wherein the amine source (ii) is diethanolamine or 2- (2-aminoethyl) aminoethanol.   The lubricant composition according to claim 9 or 10, wherein the fat (i) is a mono-, di- or tri-glyceride of a fatty acid having 4 to 28 carbon atoms, or a fatty acid having 4 to 28 carbon atoms. A lubricant composition. The lubricant composition according to any one of claims 9 to 11, wherein the organic molybdenum complex (a) is
At least one compound (a1) represented by the following formula (II), and at least one compound (a2) represented by the following formula (III):
Of these, a lubricant composition comprising (a1) alone, (a2) alone, or a mixture of (a1) and (a2).

Wherein X1 and X2 are O or N, n is 1 if X1 is O, m is 1 if X2 is O, n is 2 if X1 is N, (If X2 is N, m is 2, and R1 and R2 are C3-C27 aliphatic hydrocarbon chains.) The lubricant composition according to any one of claims 9 to 11, wherein the organic molybdenum complex (a) includes at least one compound represented by the following formula (IV).

(In the formula, R1 is an aliphatic hydrocarbon chain having 3 to 27 carbon atoms.) The lubricant composition according to any one of claims 9 to 11, wherein the organomolybdenum complex (a) includes at least one compound represented by the following formula (V).

(In the formula, R1 is an aliphatic hydrocarbon chain having 3 to 27 carbon atoms.)