JP7282907B2 - Lubricating oil composition and lubricant using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a lubricating oil composition containing silicone oil and a lubricant using the same.

Lubricating oils and lubricating oil compositions are used to reduce friction and wear between moving parts and moving surfaces of various mechanical devices.

Recently, due to the expansion and harshness of the use environment of transportation equipment, the sophistication and miniaturization of mechanical devices are progressing. BACKGROUND ART With the increasing sophistication and miniaturization of mechanical devices, lubricating oils with a high viscosity index (VI) that can be used in a wide temperature range (small changes in viscosity with respect to temperature changes) are in demand. A lubricating oil with a high VI has a low viscosity at low temperatures and a small energy loss due to the viscous resistance of the lubricating oil itself. In addition, in a high-temperature environment, compared to lubricating oils with a low VI, the viscosity does not decrease excessively, so the oil film necessary for lubrication can be maintained on the lubricating surface, and an appropriate viscosity is maintained. As a result, scattering of the lubricating oil is suppressed, and the surrounding area is less polluted.

Until now, polymer compounds such as polymethacrylates and polybutenes have been used as VI improvers as a method for increasing the viscosity index of hydrocarbon-based lubricating oils (Patent Documents 1 and 2).

In recent years, a lubricating oil composition using a silicone oil (hereinafter also referred to as Si oil), which is known as a high VI lubricating oil, as a lubricating oil base has been proposed (Patent Documents 3 and 4).

However, the lubricating oil using the conventional VI improver described in Patent Document 1 has a problem that it has low resistance to shearing force and cannot maintain the viscosity characteristics at the beginning of use for a long time (viscosity index decreases). there were. In addition, Patent Document 2 shows the possibility of increasing the shear stability by using a polymethacrylate having a specific structure. An increase in resistance was unavoidable, and there remained the problem of lack of energy efficiency when used in a low-temperature environment.

On the other hand, the technique described in Patent Document 3 uses both a silicone oil and a mineral oil-based or wax isomerized base oil for the purpose of achieving both high VI and lubricity. Since dimethyl silicone with poor compatibility with is used, a large amount of silicone oil having a high VI cannot be blended. Therefore, in order to achieve a high VI, it is necessary to use a combination of silicone oil and conventional VI improvers such as polymethacrylates and polybutenes. Although the amount was able to be reduced, there remained the problem of an increase in low-temperature viscosity and the inability to maintain the viscosity characteristics at the beginning of use for a long period of time (viscosity index decreased).

In addition, in the technique described in Patent Document 4, by using a silicone oil having an aryl group that is highly compatible with hydrocarbon-based lubricating oils, the amount of silicone oil added can be increased to maintain a high VI. . However, the lubricating property of a lubricating oil composition containing a large amount of silicone oil having an aryl group is low, and in order to obtain high lubricating property, it is necessary to increase the amount of the ester oil used as the mating material. There was a problem of incompatibility.

Furthermore, recently, in order to improve energy saving, there is a demand for lower viscosity lubricating oil compositions, and they are used in high-temperature environments and high-load applications (e.g., bearings and gears used in automobile applications). In this case, even if the lubricating oil composition has a high viscosity index, the viscosity of the lubricating oil composition decreases, resulting in a decrease in oil film-forming ability, and wear due to metal-to-metal contact becomes a problem. For this purpose, a lubricating oil composition or a lubricant having excellent lubricating properties capable of further improving wear resistance is required.

An object of the present invention is to solve the above problems. That is, it is a lubricating oil composition that combines excellent lubricity and a high viscosity index (VI), can be used stably for a long time, and can be used in a wide temperature range, and provides higher lubricity (wear resistance). An object of the present invention is to provide a lubricating oil composition capable of

JP 2015-172165 A JP 2017-155193 A JP 2012-207082 A JP 2003-261892 A

As a result of intensive studies aimed at solving the above problems, the inventors of the present invention have found that the lubricating oil composition having the following structure achieves the above objects, and have completed the present invention by conducting further studies based on this finding.

That is, the lubricating oil composition according to one aspect of the present invention is (A) represented by the following formula (1), has a mass average molecular weight of 900 to 4000, and the ratio of carbon and silicon in the structure (C/Si ratio ) is 3.03 or more and a viscosity index (VI) is 50 to 80% by mass having a viscosity index (VI) of 300 or more, (B) 10 to 49% by mass of a hydrocarbon lubricating oil, and (C) a sulfur compound It is characterized by containing at least 0.5 to 15% by mass.

（式（１）中、Ｒ_１およびＲ_２は炭素数１～１２のアルキル基またはアラルキル基であり、かつ、ｎは２～４４の整数である）

(In formula (1), R ₁ and R ₂ are alkyl groups or aralkyl groups having 1 to 12 carbon atoms, and n is an integer of 2 to 44)

As described above, the lubricating oil composition of the present invention (A) is represented by the above formula (1), has a mass average molecular weight of 900 to 4000, and has a ratio of carbon and silicon in the structure (C / Si ratio) is 3.03 or more and a viscosity index (VI) of 50 to 80% by mass having a viscosity index (VI) of 300 or more, (B) 10 to 49% by mass of a hydrocarbon lubricating oil, and (C) 0 sulfur compounds .5 to 15% by mass.

With such a configuration, a lubricating oil composition that can provide high wear resistance by having very excellent lubricity, can be used stably for a long period of time, and can be used in a wide temperature range. Become.

Embodiments of the present invention will be described in detail below, but the present invention is not limited to these.

((A) silicone oil)
The silicone oil contained in the lubricating oil composition of the present embodiment is represented by the above formula (1), has a mass average molecular weight of 900 to 4000, and has a ratio of carbon and silicon in the structure (C/Si ratio) of 3. .03 or more and a viscosity index (VI) of 300 or more. By using such a silicone oil, a lubricating oil composition having excellent low temperature fluidity and a high viscosity index can be provided.

In formula (1), R ₁ and R ₂ are alkyl or aralkyl groups having 1 to 12 carbon atoms. The structures of R ₁ and R ₂ are not particularly limited and may be linear, branched or cyclic. Specifically, for example, alkyl groups (methyl, ethyl, propyl, isopropyl, butyl, octyl, nonyl, dodecyl); cycloalkyl groups (cyclohexyl, cycloheptyl); aralkyl groups (benzyl, phenylethyl, isopropylphenyl), etc. mentioned. These functional groups may be contained singly or in combination of two or more in the structure. It is particularly preferred to have an alkyl group.

The number of carbon atoms in R ₁ and R ₂ is preferably 1 to 12, more preferably 1 to 10, and particularly preferably 1 to 8, from the viewpoint of maintaining low viscosity at low temperatures. When the number of carbon atoms in R ₁ and R ₂ exceeds 12, the low temperature properties are significantly deteriorated, making it difficult to use the lubricating oil composition in the low temperature range.

In formula (1), n is an integer of 2-44. When n is less than 2, the mass average molecular weight is less than 900, so that when it is used as a lubricating oil composition, the flash point becomes low and the application is limited.

In addition, the silicone oil of the present embodiment has a carbon-to-silicon ratio (C/Si ratio) in the structure of 3.03 or more. From the viewpoint of further improving compatibility with (B) a hydrocarbon-based lubricating oil and (C) a sulfur compound, which will be described later, the C/Si ratio is more preferably 3.05 or more.

In this embodiment, the C/Si ratio is a value determined by the following formula (1).
(Formula 1): C / Si ratio = (n × (carbon number of R ₁ + 1) + total carbon number of R ₂ + 4) ÷ (n + 2)

For example, when the silicone oil is a silicone oil having a structure represented by the following formula (2), R ₁ = C3 (n ₁ = 6) and C1 (n ₂ = 4), R ₂ = C1, so C /Si ratio is 3.16.

Further, for example, when the silicone oil is a silicone oil having a structure represented by the following formula (3), since R ₁ = C2, n = 10, and R ₂ = C1, the C/Si ratio is 3.00. be.

For example, when the silicone oil is a silicone oil having a structure represented by the following formula (4), R ₁ = C8 (n ₁ = 5) and C1 (n ₂ = 10), R ₂ = C1, so C /Si ratio is 4.18.

Further, for example, when the silicone oil is a silicone oil having a structure represented by the following formula (5), R ₁ = C6 (n ₁ = 3), C9 (n ₂ = 2), and C1 (n ₃ = 11 ), and R ₂ =C1, so the C/Si ratio is 3.83.

For example, when the silicone oil is a silicone oil having a structure represented by the following formula (6), R ₁ = C8 (n ₁ = 5) and C1 (n ₂ = 10), R ₂ = C1 and C8 , the C/Si ratio is 4.59.

Further, for example, when the silicone oil is a silicone oil having a structure represented by the following formula (7), the alkyl group is R ₁ =C1, n = 9, and R ₂ =C12, so the C/Si ratio is 4 .18.

If the C/Si ratio is less than 3.03, the compatibility with the hydrocarbon-based lubricating oil of the component (B) is deteriorated, and there is a problem that stable performance as a lubricating oil composition cannot be exhibited. On the other hand, although the upper limit of the C/Si ratio is not particularly limited, it is preferably 9.0 or less from the viewpoint that if the C/Si ratio becomes too high, the viscosity index becomes low.

Specific examples of silicone oils having the above structure include methylhexylpolysiloxane and methyloctylpolysiloxane.

The mass average molecular weight of the silicone oil of this embodiment is 900-4000. If the weight average molecular weight is less than 900, the flash point of the silicone oil will be less than 200°C, and the use of the silicone oil as a lubricating oil composition will be limited. Further, when the mass average molecular weight exceeds 4000, the 40° C. kinematic viscosity exceeds 200 mm ² /s, so that the viscosity of the lubricating oil composition becomes high and the energy saving performance is lacking.

The weight average molecular weight of the silicone oil in the present embodiment is a value measured using ¹ H-NMR or ²⁹ Si-NMR, as shown in Examples below. In addition, below, a mass average molecular weight is also simply called "average molecular weight."

The viscosity index (VI) of the silicone oil in this embodiment is set to 300 or more in order to obtain a lubricating oil composition with a high VI. It is more preferably 350 or more, and particularly preferably 400 or more. In this specification, VI is a value measured and calculated based on JIS K 2283 (2000).

As the (A) silicone oil of the present embodiment, the above-described silicone oils may be used alone, or a plurality of them may be used in combination.

Although the method for synthesizing the silicone oil as described above is not particularly limited, for example, a linear polysiloxane having a SiH group in the molecular structure and a polysiloxane with a low degree of polymerization such as hexamethyldisiloxane are mixed with activated clay or the like. A polysiloxane having SiH groups with a low degree of polymerization can be obtained by carrying out the equilibration reaction in the presence of an acid catalyst. Alternatively, methyloctylpolysiloxane can be obtained by adding an olefin compound such as 1-octene to a polysiloxane having SiH groups under a nitrogen atmosphere in the presence of a hydrosilylation catalyst.

In the lubricating oil composition of the present embodiment, the content of the (A) silicone oil relative to the entire composition is 50 to 80% by mass from the viewpoint of viscosity index and lubricity. It is particularly preferably 55 to 80% by mass, more preferably 65 to 75% by mass. If the content of component (A) is less than 50% by mass, the effect of improving the viscosity index of the lubricating oil composition is poor. .

((B) Hydrocarbon-based lubricating oil)
The lubricating oil composition of this embodiment has a hydrocarbon-based lubricating oil. The hydrocarbon-based lubricating oil that can be used is not particularly limited as long as it is compatible with the above-mentioned (A) silicone oil, but specifically, for example, ester oil, ether oil, poly-alpha olefin ( PAO) oil, mineral oil, and the like.

Specific examples of the ester oils include esters of monohydric alcohols or polyhydric alcohols and monobasic acids or polybasic acids.

Examples of the monohydric alcohol or polyhydric alcohol include monohydric alcohols or polyhydric alcohols having a hydrocarbon group having 1 to 30 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 6 to 18 carbon atoms. . Specific examples of the polyhydric alcohols include trimethylolpropane, pentaerythritol, and dipentaerythritol.

Examples of the monobasic acid or polybasic acid include monobasic acids or polybasic acids having a hydrocarbon group having 1 to 30 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 6 to 18 carbon atoms. be done.

The hydrocarbon group referred to herein may be straight chain or branched chain, and includes, for example, an alkyl group, an alkenyl group, a cycloalkyl group, an alkylcycloalkyl group, an aryl group, an alkylaryl group and an arylalkyl group. and other hydrocarbon groups.

When ester oils are used as the component (B) in the present embodiment, the above ester oils may be used alone or in combination of two or more.

In a preferred embodiment, a dibasic acid ester or polyhydric alcohol fatty acid ester having a flash point of 200° C. or higher and a pour point of -40° C. or lower can be used as the ester oil. In particular, polyhydric alcohol fatty acid esters such as trimethylolpropane fatty acid esters and pentaerythritol fatty acid esters are more preferable from the viewpoint of low volatility.

Specific examples of the ether oils include polyoxyethers, dialkyl ethers, and aromatic ethers.

Examples of the poly-α-olefin oils include polymers of α-olefins having 2 to 15 carbon atoms such as polybutene, 1-octene oligomers and 1-decene oligomers, and hydrogenated products thereof.

Examples of the mineral oil include atmospheric residual oils obtained by atmospheric distillation of crude oils such as paraffinic, naphthenic, and intermediate base oils; distillate oils obtained by vacuum distillation of the atmospheric residual oils; Mineral oils refined by one or more of solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, etc., e.g. light neutral oil, medium neutral oil Mineral oil obtained by isomerizing wax (GTL wax (Gas To Liquids WAX)) produced by the Fischer-Tropsch process or the like, such as oil, heavy neutral oil, bright stock, and the like.

In this embodiment, the above-described hydrocarbon-based lubricating oils can be used alone as the component (B), or two or more of them can be used in combination.

The content of (B) hydrocarbon-based lubricating oil in the lubricating oil composition of the present embodiment is 10 to 49% by mass based on the entire composition from the viewpoint of lubricity and viscosity index. It is more preferably 15 to 40% by mass, and particularly preferably 15 to 25% by mass. If the content of the hydrocarbon-based lubricating oil is less than 10% by mass, it becomes difficult to obtain sufficient lubricity, and if it exceeds 49% by mass, the content of the silicone oil in the lubricating oil composition is low. This is not preferable because the viscosity index of the lubricating oil composition becomes low.

Furthermore, the lubricating oil composition of the present embodiment further improves the lubricity of the lubricating oil composition by containing 10% by mass or more of an ester oil as (B) a hydrocarbon-based lubricating oil. In other words, in a preferred embodiment, the (B) hydrocarbon lubricating oil preferably contains 10 to 49% by mass of an ester oil.

((C) sulfur compound)
Sulfur compounds of component (C) of the present embodiment include thiadiazole compounds, polysulfides, thiocarbamate compounds, sulfurized fats and oils, sulfurized olefins, sulfurized esters, sulfurized fatty acids, thiophosphates, thiophosphates, thiophosphites, dialkylthio Molybdenum carbamate, molybdenum dialkyldithiophosphate, zinc dialkylthiocarbamate, and zinc dialkylthiophosphate can be used without particular limitation. acid esters, zinc dialkylthiophosphates, and the like.

Among them, it is preferable to use at least one selected from thiophosphates, dithiocarbamates, sulfurized olefins, and dimercaptothiadiazole compounds.

By containing such a sulfur compound, the lubricating oil composition of the present embodiment has extremely high lubricating properties in addition to the properties described above, and can greatly improve wear resistance. Although the reason for this is not clear, it is speculated that a lubricating film derived from a sulfur compound is formed on the target metal surface from the initial stage of use, exhibiting high wear resistance.

The content of (C) the sulfur compound in the lubricating oil composition of the present embodiment is about 0.5 to 15% by mass with respect to the entire composition from the viewpoint of obtaining sufficient wear resistance. If the content of the sulfur compound is less than 0.5% by mass, sufficient wear resistance may not be obtained, and if it exceeds 15% by mass, the evaporation of the sulfur compound itself causes the lubricating oil composition to evaporate. An increase in the amount is less preferable than a decrease in the viscosity index of the lubricating oil composition.

The more preferable content of (C) the sulfur compound may vary depending on the composition of the base oil, the type of sulfur compound, the sulfur content, and the like. For example, for sulfurized olefins and the like, it is more preferably 0.5 to 4.5% by mass with respect to the entire composition, and for thiophosphates, dithiocarbamate, dimercaptothiadiazole compounds and the like, it is 0.5 to 10.5% by mass. It is preferably 0% by mass, more preferably about 0.5 to 5.0% by mass.

((D) antioxidant)
The lubricating oil composition of the present embodiment preferably further contains (D) an antioxidant in addition to the above components. Thereby, there is an advantage that the life of the lubricating oil composition can be extended.

As the (D) antioxidant used in the present embodiment, antioxidants generally used in lubricating oils can be used without particular limitation. Examples include phenol compounds, amine compounds, phosphorus compounds, and the like.

More specifically, for example, alkylphenols such as 2,6-di-tert-butyl-4-methylphenol, methylene-4,4-bisphenol (2,6-di-tert-butyl-4-methylphenol) bisphenols such as phenyl-α-naphthylamine, naphthylamines such as phenyl-α-naphthylamine, dialkyldiphenylamines, and phosphites.

Among these, from the viewpoint of further improving lubricity, it is preferable to contain phosphorus-based compounds such as phosphates, phosphites, acidic phosphates, and phosphonates.

Furthermore, it is preferable that two or more (D) antioxidants are used in combination in the lubricating oil composition of the present embodiment. For example, it is particularly preferable to use a phenol-based compound or an amine-based compound that functions as a primary antioxidant together with a secondary antioxidant such as a phosphorus-based compound.

When the lubricating oil composition of the present embodiment contains (D) an antioxidant, the content of the (D) antioxidant with respect to the entire composition is 1 to 10% by mass from the viewpoint of oxidation suppression and evaporation reduction. and More preferably, it is 2 to 7% by mass, and particularly preferably 1 to 5% by mass. If the content of the component (D) is less than 1% by mass, the evaporability of the lubricating oil composition may increase, and if it exceeds 10% by mass, the antioxidant itself may evaporate. An increase in the amount of evaporation of the lubricating oil composition and a decrease in the viscosity index of the lubricating oil composition are more undesirable.

From the viewpoint of further improving lubricity, the total amount of the (C) sulfur compound and (D) antioxidant is preferably about 2.5 to 8.0% by mass with respect to the entire composition. .

(Other additives)
For the purpose of further improving the performance of the lubricating oil composition of the present embodiment, or in order to impart further performance as necessary, within a range that does not impair the effects of the present invention, a metal deactivator, Various additives such as antifoaming agents, thickeners and colorants may be blended singly or in combination.

Examples of metal deactivators include benzotriazole-based, tolyltriazole-based, and imidazole-based compounds.

Defoamers include, for example, polysiloxanes, polyacrylates, styrene ester polymers, and the like.

Thickeners include, for example, metal soaps (eg, lithium soap), silica, expanded graphite, polyurea, clays (eg, hectorite or bentonite), and the like.

When the additive as described above is blended in the lubricating oil composition in the present embodiment, the amount added is 0.0 to 10.0% by mass, or 0 It can be used in amounts of the order of .1 to 5% by weight. Thickeners for producing greases using the lubricating oil compositions of the present embodiments may be used in amounts of 5 to 25% by weight of the total lubricant grease composition (total weight).

(Preparation method)
The method for preparing the lubricating oil composition of the present embodiment is not particularly limited, for example, (A) silicone oil and (B) hydrocarbon oil, and (C) sulfur compound, and if necessary ( D) It can be adjusted by heating an antioxidant and other additives to 100° C. and mixing them.

(Application)
Since the lubricating oil composition of the present embodiment can be used stably for a long period of time and in a wide range of temperatures, it can be used as various lubricants. For example, it is suitably used as a lubricant for bearings, a lubricant for impregnated bearings, a grease base oil, a refrigerator oil, a plasticizer, and the like. In particular, it is suitable for high-load applications because it has extremely excellent lubricity and can impart wear resistance.

As described above, this specification discloses technologies of various aspects, and the main technologies thereof are summarized below.

The lubricating oil composition according to one aspect of the present invention is (A) represented by the above formula (1), has a mass average molecular weight of 900 to 4000, and a ratio of carbon and silicon in the structure (C / Si ratio) 3.03 or more and 50 to 80% by mass of a silicone oil having a viscosity index (VI) of 300 or more, (B) 10 to 49% by mass of a hydrocarbon lubricating oil, and (C) a sulfur compound of 0. It is characterized by containing at least 5 to 15% by mass.

To provide a lubricating oil composition capable of imparting high wear resistance by having extremely excellent lubricating properties and being able to be used stably for a long period of time and usable in a wide temperature range. can be done.

Furthermore, in the lubricating oil composition, the (C) sulfur compound is preferably at least one selected from thiadiazole compounds, thiocarbamate compounds, sulfurized olefins, thiophosphates, and zinc dialkylthiophosphates. Thereby, the above effect can be obtained more reliably.

Furthermore, the lubricating oil composition preferably contains (D) an antioxidant, more preferably two or more (D) antioxidants. As a result, the above effects can be obtained more reliably, and the amount of evaporation can be reduced.

A lubricant relating to another aspect of the present invention is characterized by using the lubricating oil composition described above.

The present invention also includes greases and emulsions using the above lubricating compositions and lubricants, lubricating methods using them, and uses of the above lubricating compositions and lubricants for bearing applications.

Examples of the present invention will be described below, but the present invention is not limited to these.

First, each raw material used in this example is shown below.

[Synthesis of silicone oil]
・Silicone oil 1 (octyl silicone)
1125 g of methylhydrogenpolysiloxane (trade name: KF-99) manufactured by Shin-Etsu Chemical Co., Ltd. and 2866 g of decamethylcyclopentasiloxane (trade name: KF-995) manufactured by Shin-Etsu Chemical Co., Ltd. were placed in a 10 L separable flask. , 874 g of hexamethyldisiloxane (trade name: KF-96L-0.65CS) manufactured by Shin-Etsu Chemical Co., Ltd. and 56 g of activated clay were added and stirred at 90° C. for 4 hours. After cooling to room temperature, the activated clay was removed by filtration.

Subsequently, the filtrate is placed in a 10 L four-necked flask, heated and decompressed to remove low-molecular-weight silicone compounds, and a trimethylsiloxy group-blocked dimethylsiloxane/methylhydrogensiloxane copolymer (silicone A ) to give 3016 g. The resulting silicone A was reacted with an excess amount of aqueous sodium hydroxide solution and n-butanol, and the amount of hydrogen gas generated was measured. The amount of hydrogen gas generated was 86 mL/g. The amount of hydrogen derived from hydrosilyl groups in silicone A was calculated from the amount of hydrogen gas generated and found to be 0.39% by mass.

2319 g (2.16 mol) of the resulting silicone A was placed in a 5 L four-neck flask, and 1221 g (10.88 mol) of 1-octene (trade name: Linearene 8) manufactured by Idemitsu Kosan Co., Ltd. and N-Octene were added to the dropping funnel. 0.3 mL of Pt-CTS-toluene solution (Pt conversion: 4 ppm), which is a platinum catalyst manufactured by E-Chemcat Co., Ltd., was put into the reactor, and the reactor was replaced with nitrogen. After the silicone A was heated and the liquid temperature reached 60° C., dropwise addition of a mixture of 1-octene and a platinum catalyst was started. At this time, the dropping speed was adjusted so as to keep the liquid temperature at 80 to 110°C. After dropping all the mixture of 1-octene and platinum catalyst, it was aged at 100° C. for 2 hours. After the aging was completed, disappearance of the SiH group peak was confirmed using ¹ H-NMR. Subsequently, the reaction mixture was heated under reduced pressure to remove excess 1-octene from the reaction product to obtain 3251 g of a trimethylsiloxy group-blocked dimethylsiloxane/methyloctylsiloxane copolymer (silicone 1) at both ends of the molecular chain.

As a result of analyzing the obtained silicone 1 using ¹ H-NMR, the average molecular weight was 1741, the average number of units (n ₁ ) having the organic group R ₁ (C8) was 4.7, and the organic group R ₁ ' ( It was found that the average number of units (n ₂ ) having C1) was 10.3 and the C/Si ratio in the molecular structure was 4.05.

The NMR data for Silicone 1 were as follows.
¹ H-NMR (solvent: deuterated chloroform, reference material: TMS)
If the integrated value of δ = 0.40 to 0.60 ppm is 10.0,
The integrated value of δ = 0.01 to 0.08 ppm is 80.8
The integrated value of δ = 0.08 to 0.10 ppm is 19.1

・Silicone oil 2 (octyl silicone)
In a 2 L separable flask, 451 g of methylhydrogenpolysiloxane (trade name: KF-99) manufactured by Shin-Etsu Chemical Co., Ltd. and 1149 g of decamethylcyclopentasiloxane (trade name: KF-995) manufactured by Shin-Etsu Chemical Co., Ltd. , 57 g of hexamethyldisiloxane (product name: KF-96L-0.65CS) manufactured by Shin-Etsu Chemical Co., Ltd. and 10 g of activated clay were added and stirred at 90° C. for 4.5 hours. After cooling to room temperature, the activated clay was removed by filtration.

Subsequently, the filtrate is placed in a 2 L four-necked flask, heated and depressurized to remove low-molecular-weight silicone compounds, and a trimethylsiloxy group-blocked dimethylsiloxane/methylhydrogensiloxane copolymer (silicone B ) to give 1474 g. The resulting silicone B was reacted with an excess amount of aqueous sodium hydroxide solution and n-butanol, and the amount of hydrogen gas generated was measured. The amount of hydrogen gas generated was 96 mL/g. The amount of hydrogen derived from hydrosilyl groups in silicone B was calculated from the amount of hydrogen gas generated and found to be 0.43% by mass.

641 g of silicone B was put in a 2 L four-neck flask, and 382 g (3.41 mol) of 1-octene (trade name: Linearene 8) manufactured by Idemitsu Kosan Co., Ltd. and NE Chemcat Co., Ltd. were added to the dropping funnel. 80 μL of a platinum catalyst Pt-CTS-toluene solution (Pt conversion: 3 ppm) was put into the flask, and nitrogen substitution was performed. After the silicone B was heated and the liquid temperature reached 60° C., dropwise addition of a mixture of 1-octene and a platinum catalyst was started. At this time, the dropping speed was adjusted so as to keep the liquid temperature at 80 to 110°C. After dropping all the mixture of 1-hexene and platinum catalyst, it was aged at 100° C. for 2 hours. After the aging was completed, disappearance of the SiH group peak was confirmed using ¹ H-NMR. Subsequently, the mixture was heated and decompressed to remove excess 1-octene from the reaction product, thereby obtaining 906 g of a dimethylsiloxane/methyloctylsiloxane copolymer (silicone 2) capped with trimethylsiloxy groups at both ends of the molecular chain.

As a result of analyzing silicone 2 obtained using ¹ H-NMR, the average molecular weight was 3868, the average number of units (n ₁ ) having an organic group R ₁ (C8) was 11.1, and the organic group R ₁ '( It was found that the average number of units (n ₂ ) having C1) was 24.1 and the C/Si ratio in the molecular structure was 4.14.

The NMR data for Silicone 2 were as follows.
¹ H-NMR (solvent: deuterated chloroform, reference substance: TMS)
If the integrated value of δ = 0.40 to 0.60 ppm is 10.0,
The integrated value of δ = 0.01 to 0.08 ppm is 80.2
The integrated value of δ = 0.08 to 0.10 ppm is 8.1

(hydrocarbon lubricating oil)
Ester oil: pentaerythritol fatty acid ester manufactured by NOF Corporation, product name: Unistar HR-32 (40°C kinematic viscosity: 33.5: mm ² /s, 100°C kinematic viscosity: 5.8 mm ² /s, VI: 115, flash point: 274°C, pour point: -50°C)
Ether oil: Alkyl diphenyl ether "MORESCO Hilube LB-100" manufactured by MORESCO Corporation (40°C kinematic viscosity: 102.6 mm ² /s, 100°C kinematic viscosity: 12.6 mm ² /s, VI: 117)
- PAO oil: poly-alpha olefin manufactured by Chevron Phillips, product name: Synfluid PAO 6 cSt (40°C kinematic viscosity: 30.5 mm ² /s, 100°C kinematic viscosity: 5.9 mm ² /s, VI: 137)
・PAG (polybutylene glycol): "UCON OSP-32" manufactured by DOW Corporation (40°C kinematic viscosity: 32.0 mm ² /s, 100°C kinematic viscosity: 6.5 mm ² /s, VI: 146)
Mineral oil: Mineral oil manufactured by Cosmo Oil Lubricants Co., Ltd., product name: Cosmo Pure Spin TK (40° C. kinematic viscosity: 9.3 mm ² /s, 100° C. kinematic viscosity: 2.5 mm ² /s, VI: 94)
・Liquid paraffin: “Moresco White P-70” manufactured by MORESCO Co., Ltd. (40° C. kinematic viscosity: 12.6 mm ² /s, 100° C. kinematic viscosity: 2.9 mm ² /s, VI: 56)

(Sulfur compound)
・Sulfur compound 1: isobutene sulfide, manufactured by Rhein Chemie, “RC 2545” ・Sulfur compound 2: dithiocarbamate, manufactured by DOG DEUTSCHE OELFABRIK “DeoAdd V 300”
- Sulfur compound 3: Dimercaptothiadiazole compound, "RC 8213" manufactured by Rhein Chemie
・ Sulfur-based compound 4: thiophosphate, "LUBRIZOL IC9AW31" manufactured by LUBRIZOL
・ Sulfur-based compound 5: Zinc dialkyldithiophosphate, ADEKA's "ADEKAKI CLUB Z-112"

(Antioxidant)
- Primary antioxidant 1: BASF aromatic amine compound, "IRGANOX L-57"
- Primary antioxidant 2: Phenolic compound manufactured by BASF, "IRGANOX L-135"
・Secondary antioxidant: “JP-310”, a phosphite ester compound manufactured by Johoku Chemical Industry Co., Ltd.

(others)
・ Phosphorus-based extreme pressure agent: amine salt of fatty acid phosphate ester, "NA-LUBE AW-64" manufactured by Kingindustries
- Metal deactivator: Benzotriazole compound "CUVAN303" manufactured by VANDERBILT

[Examples 1 to 22 and Comparative Examples 1 to 7]
Each component is blended so that the ratio (% by mass) shown in Tables 1 to 3 below is obtained, (A) silicone oil and (B) hydrocarbon oil, (C) sulfur compound, and (D) oxidation Lubricating oil compositions of Examples 1-22 and Comparative Examples 1-7 were prepared by heating the inhibitor and other additives to 100° C. and mixing.

Lubricating properties of the obtained lubricating oil compositions of Examples and Comparative Examples were evaluated by the following test methods.
(Lubricity)
Lubricity evaluation was performed with the high speed 4-ball test. Specifically, it was evaluated using a Falex lubrication tester (#6). The test conditions were rotation speed: 1200 rpm, lubricating oil composition temperature: 75°C, load: 392 N, test time: 60 minutes, and the evaluation was made by the wear scar diameter. The evaluation criteria based on the wear scar diameter were: more than 600 μm: ×, 550 to 600 μm: ◯, and less than 550 μm: ⊙.

The results are shown in Tables 1-3.

(Discussion)
Examples 1-22 demonstrate that very high lubricity (wear resistance) can be achieved with the lubricating oil composition of the present invention containing silicone oil, hydrocarbon lubricating oil, and sulfur compound. In particular, there were examples in which the wear scar diameter could be less than 550 μm, and even less than 500 μm, depending on the type and content of the sulfur compound and the combined use with the antioxidant.

On the other hand, Comparative Examples 1 to 5 did not contain a sulfur compound, and therefore were inferior in lubricity to those of the Examples. Sufficient lubricity could not be obtained in Comparative Example 6, which contained a phosphorus-based extreme pressure agent instead of a sulfur compound, and in Comparative Example 7, which contained only 0.1% by mass of a sulfur compound.

This application is based on Japanese Patent Application No. 2019-190818 filed on October 18, 2019, the contents of which are included in the present application.

In order to express the present invention, the present invention has been adequately and fully described through the embodiments with reference to specific examples and the like in the foregoing, but those skilled in the art can easily modify and/or improve the above-described embodiments. It should be recognized that it is something that can be done. Therefore, to the extent that modifications or improvements made by those skilled in the art do not deviate from the scope of the claims set forth in the claims, such modifications or modifications do not fall within the scope of the claims. is interpreted to be subsumed by

Since the lubricating oil composition of the present invention can be used as a lubricating oil having excellent lubricating properties, it can be suitably used as a lubricant for bearings, a lubricant for impregnated bearings, a grease base oil, a refrigerator oil, a plasticizer, etc. can. Especially suitable for high load applications.

Claims (9)

(A) is represented by the following formula (1), has a mass average molecular weight of 900 to 4000, has a carbon-to-silicon ratio (C/Si ratio) in the structure of 3.03 or more, and has a viscosity index (VI ) is 300 or more and 50 to 80% by mass of silicone oil,
(B) 10 to 49% by mass of hydrocarbon lubricating oil,
(C) a lubricating oil composition containing at least 0.5 to 15% by mass of sulfur compounds;

(In formula (1), R ₁ and R ₂ are alkyl groups or aralkyl groups having 1 to 12 carbon atoms, and n is an integer of 2 to 44) The lubricating oil composition according to claim 1, wherein the sulfur compound (C) is at least one selected from thiadiazole-based compounds, thiocarbamate-based compounds, sulfurized olefins, thiophosphates, and zinc dialkylthiophosphates. 3. The lubricating oil composition according to claim 1, further comprising (D) an antioxidant. 4. The lubricating oil composition of claim 3, comprising two or more (D) antioxidants. A lubricant using the lubricating oil composition according to any one of claims 1 to 4. Grease using the lubricating oil composition according to any one of claims 1 to 4 or the lubricant according to claim 5. An emulsion using the lubricating oil composition according to any one of claims 1 to 4 or the lubricant according to claim 5. A lubricating method using the lubricating oil composition according to any one of claims 1 to 4. The lubricating oil composition according to any one of claims 1 to 4, which is for bearings.