WO2018155601A1

WO2018155601A1 - Lubricating oil additive and method for producing lubricating oil additive

Info

Publication number: WO2018155601A1
Application number: PCT/JP2018/006596
Authority: WO
Inventors: 智之園田
Original assignee: 株式会社Ｓｏｎｏｄａ
Priority date: 2017-02-22
Filing date: 2018-02-22
Publication date: 2018-08-30
Also published as: KR102345529B1; EP3587542B1; KR20190117525A; JPWO2018155601A1; CN110300796A; EP3587542C0; US20200002639A1; AU2018224752A1; AU2018224752B2; EP3587542A4; SG11201907681QA; EP3587542A1; JP6465536B2

Abstract

This lubricating oil additive is to be added to a lubricating oil, and is characterized by containing: a polyol ester synthetic base oil that is contained in an amount of 30.0-60 wt% in the lubricating oil additive; a sulfonic acid calcium salt that is contained in an amount of 5.0-30.0 wt% in the lubricating oil additive, that has calcite crystal structure, and that contains calcium carbonate; a poly-alpha-olefin oligomer; a zinc dithiophosphate antioxidant; a succinic acid imide; a thiadiazole extreme pressure agent; and a phenolic antioxidant.

Description

[Replenishment based on Rule 26 29.03.2018] Lubricating oil additive and manufacturing method of lubricating oil additive

Import by reference

This application claims the priority of Japanese Patent Application No. 2017-31602 filed on Feb. 22, 2017, and is incorporated herein by reference.

The present invention relates to a lubricant additive and a method for producing a lubricant additive.

Conventionally, lubricating oil used for smooth operation of an engine, a gear (transmission), a differential gear (differential device) and the like of a vehicle such as an automobile is known. Various additives are blended depending on the use of the lubricating oil for the purpose of enhancing and improving the lubricating performance of the lubricating oil. Examples of the additive for lubricating oil (hereinafter, also simply referred to as “lubricating oil additive”) include an antiwear agent, a friction modifier, a cleaning dispersant, a viscosity index improver, an extreme pressure agent, and an antioxidant. . And the additive suitable for the said use is selected from these several types of additives according to the use of lubricating oil, and is mix | blended. Various inventions have been made regarding such lubricating oil additives (see, for example, Patent Documents 1 and 2).

Patent Document 1 includes a high-molecular-weight lubricating part that can be dissolved in a base oil of a lubricating oil, and a pair of adsorbing parts that have a functional group that can be adsorbed to a material and are coupled to the lubricating part so as to sandwich the lubricating part. A lubricating oil additive is disclosed. According to the technique according to Patent Document 1, a pair of adsorbing portions are adsorbed on a material, and a high molecular weight lubricating portion that can be dissolved in a base oil sandwiched between the adsorbing portions remains between the materials. The lubrication part and each adsorption part between these materials play a role as an oiliness improver, whereby an excellent friction reducing effect is obtained.

Japanese Patent Document 2, a dialkyl monoether kinematic viscosity at 100 ° C. is ^{0.50 ~ 2.50mm 2 / s (A} ), and poly -α- olefin kinematic viscosity at 100 ° C. is 50 mm ² / s or more A lubricating oil composition comprising at least a base oil containing (B) and having a kinematic viscosity at 100 ° C. of 6.00 mm ² / s or less is disclosed. According to the technique according to Patent Document 2, although it is low in viscosity, it has excellent viscosity-temperature characteristics, low-temperature fluidity, and evaporation characteristics, good shear stability and oxidation stability, and organic materials such as rubber swell. The effect of being difficult is obtained.

Japanese Patent Laid-Open No. 2016-210941 JP 2016-011384 A

By the way, as described above, the lubricant additive is generated by selecting and blending an additive suitable for the use of the lubricant from a plurality of types of additives. Therefore, for example, the lubricant additive for engines and the lubricant additive for gears are different, and the lubricant additive for engines is not necessarily a lubricant additive suitable for gears. Therefore, when the user tries to apply the lubricating oil to each device of the vehicle, there is a problem that a lubricating oil additive must be prepared for each device.

On the other hand, as shown in the techniques described in Patent Documents 1 and 2 above, the conventional invention is generally an invention aimed at improving the performance of individual lubricating oil additives, and solves the above problems. I couldn't.

This invention is made | formed in view of said point, and it aims at providing the manufacturing method of the lubricating oil additive and lubricating oil additive which can be applied comprehensively with respect to the lubricating oil of various uses. .

To achieve the above object, a lubricating oil additive according to the present invention is a lubricating oil additive added to a lubricating oil, and includes a polyol ester synthetic base oil and calcium carbonate having a calcite crystal structure. It includes a calcium sulfonate, a poly α-olefin oligomer, a zinc dithiophosphate antioxidant, a succinimide, a thiadiazole extreme pressure agent, and a phenol antioxidant.

In order to achieve the above object, a method for producing a lubricating oil additive according to the present invention is a method for producing a lubricating oil additive to be added to a lubricating oil, comprising a polyol ester synthetic base oil and a poly α The first step of heating and mixing the olefin oligomer at 50 ° C. or higher and 90 ° C. or lower in a predetermined container, and the product generated by mixing in the first step, zinc dithiophosphate-based antioxidant, A second step in which succinimide, a thiadiazole extreme pressure agent, and a phenolic antioxidant are mixed and dissolved in the product, and the product produced by mixing in the second step is a calcite crystal. And a third step of mixing a calcium sulfonate salt containing calcium carbonate having a structure.

According to the present invention, it is possible to provide a lubricating oil additive and a method for producing the lubricating oil additive that can be comprehensively applied to lubricating oils for various uses.

It is a flowchart which shows an example of the manufacturing method of the lubricating oil additive which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described.

[Composition of lubricating oil additive]
The lubricating oil additive according to the embodiment of the present invention is composed of the following components A to G.

[Component A]
Component A used in the lubricating oil additive according to the present embodiment is a kind of ester base oil, and has a low pour point, a high viscosity index, a high flash point, and excellent thermal stability and oxidation stability. It is a polyol ester-based synthetic base oil. Specifically, tri (caprylic acid / capric acid) trimethylolpropane which is a single substance fatty acid ester in which two kinds of fatty acids are combined.

The content of the component A in the lubricating oil additive is 25.0 wt% or more and 75.0 wt% or less, more preferably 35.0 wt% or more and 60.0 wt% or less.

Component A is not limited to the above tri (caprylic acid / capric acid) trimethylolpropane. Other fatty acids such as pelargonic acid, undecanoic acid, and laurin, which are linear saturated fatty acids having 8 to 18 carbon atoms (hereinafter, excluding caprylic acid having 8 carbon atoms and capric acid having 10 carbon atoms). Synthetic base oils with acids, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, and caproleic acid, undecylenic acid, and Lindelic acid, which are linear unsaturated fatty acids having 8 to 18 carbon atoms , Synthetic base oils such as lauroleic acid, tuzuic acid, fisetreic acid, myristoleic acid, zomarinic acid, petrothelic acid, oleic acid, and elaidic acid. Further, it may be a diester base oil that has a low friction reducing effect as compared with a polyol ester but is excellent in high-temperature oxidation stability.

[Component B]
Component B used in the lubricating oil additive according to this embodiment is called a poly α-olefin (PAO) oligomer obtained by polymerizing a known α-olefin. Alpha olefin oligomers (high viscosity PAO) are used. The known α-olefin is, for example, an α-olefin having 2 to 20 carbon atoms, and specifically includes ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1 -Nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene or 1-icosene, Polymerize alone or in combination.

Poly α-olefin oligomer has a uniform molecular structure that does not contain unsaturated double bonds or sulfur, etc., although it has a composition close to that of mineral oil, high temperature thermal stability, shear stability, low pour point (low temperature fluidity) , High viscosity index, high flash point. Specifically, a three-dimensional structure polyα-olefin oligomer produced using a metallocene catalyst is preferable, and this polyα-olefin oligomer is compared with one having a straight-chain structure produced using another catalyst. The viscosity is difficult to drop.

The content of the component B in the lubricating oil additive is 10.0% by weight or more and 50.0% by weight or less, and more preferably 10.0% by weight or more and 30.0% by weight or less.

The component B is not limited to the above-mentioned poly α-olefin oligomer having a three-dimensional structure. Other viscosity index improvers, such as polyalkyl methacrylate, ethylene / propylene copolymer, styrene / butadiene copolymer, and the like, may be blended.

[Component C]
Component C used in the lubricating oil additive according to the present embodiment is a zinc dithiophosphate antioxidant mainly composed of zinc dithiophosphate, and has a characteristic that it can exhibit performance in a relatively low temperature region. In the present embodiment, it refers to an antioxidant mainly composed of zinc dithiophosphate having a primary alkyl group. This primary alkyl group zinc dithiophosphate has very good anti-wear properties compared to secondary alkyl groups and tertiary alkyl group zinc dithiophosphates. Specifically, zinc 2-ethylhexyl dithiophosphate.

The content of the component C in the lubricating oil additive is 0.5 wt% or more and 3.0 wt% or less, more preferably 1.0 wt% or more and 2.0 wt% or less.

Component C is not limited to the above zinc 2-ethylhexyl dithiophosphate. Other antioxidants, for example, dialkyl such as zinc dipropyl dithiophosphate, zinc dibutyl dithiophosphate, zinc dipentyl dithiophosphate, zinc diheptyl dithiophosphate, zinc dioctyl dithiophosphate, zinc didecyl dithiophosphate or zinc didodecyl dithiophosphate Zinc dithiophosphate (ZnDTP) may be blended alone or in combination. In particular, when a diester synthetic base oil is blended as component A, it is preferable to contain zinc dipropyldithiophosphate, zinc dibutyldithiophosphate, or zinc dioctyldithiophosphate alone or in combination.

[Component D]
Component D used in the lubricating oil additive according to the present embodiment is a dispersant called alkenyl or alkyl succinimide having a characteristic of dispersing sludge and soot at low temperatures in the oil. The alkenyl or alkyl succinimide has an effect of helping the solubility of each additive to be added and increasing the durability of the performance. In the present embodiment, it particularly refers to polyisobutenyl succinimide having a nitrogen content of 1.0 to 2.0%.

The content of the component D in the lubricating oil additive is 3.0% by weight or more and 10.0% by weight or less, more preferably 4.0% by weight or more and 6.0% by weight or less.

Component D is not limited to the above polyisobutenyl succinimide. Other alkenyl or alkyl succinimide may be blended alone or in combination.

[Component E]
Component E used in the lubricating oil additive according to this embodiment is a thiadiazole-based extreme pressure agent called a thiadiazole (benzobis) derivative, which reduces friction and wear between two metal surfaces and prevents seizure. It also has a feature as an antiwear agent. The thiadiazole derivative used in the present embodiment is a dimercaptothiadiazole derivative, specifically 2,5-dimercapto-1,3,4-thiadiazole, 4,5-dimercaptothiadiazole, 3,5-dimercapto. -1,2,4-thiadiazole or 3,4-dimercapto-1,2,5-thiadiazole is used alone or in combination.

The content of the component E in the lubricating oil additive is 1.0% by weight or more and 6.0% by weight or less, and more preferably 2.0% by weight or more and 4.0% by weight or less.

The component E is not limited to the dimercaptothiadiazole derivative described above. Other extreme pressure agents such as triazole derivatives may be blended. In particular, when blending a diester synthetic base oil as component A, from the viewpoint of simplification of product production and price reduction, a sulfur-based extreme pressure such as a sulfurized fatty acid ester containing a sulfur element instead of a thiadiazole derivative. The formulation of the agent is preferred. In this case, the content in the lubricating oil additive is 1.0% by weight or more and 9.0% by weight or less, and more preferably 4.0% by weight or more and 8.0% by weight or less.

[Component F]
Component F used in the lubricating oil additive according to the present embodiment is a phenolic antioxidant blended from the viewpoint of preventing oxidation and preventing sludge formation. Specifically, for example, it is generally used as a phenolic antioxidant. 2,6-di-tert-butyl-4-methylphenol used in

The content of the component F in the lubricating oil additive is 0.1 wt% or more and 2.0 wt% or less, more preferably 0.1 wt% or more and 1.5 wt% or less.

Component F is not limited to the above 2,6-di-tert-butyl-4-methylphenol. You may mix | blend another phenolic antioxidant. For example, 2,6-di-tert-butyl-4-ethylphenol, 4,4′-methylenebis (2,6-di-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert- Butylphenol) and the like.

[Component G]
Component G used in the lubricating oil additive according to this embodiment is a detergent called an overbased calcium sulfonate that is usually used for industrial lubricating oil and contains calcium carbonate and calcium hydroxide. Specifically, a calcium sulfonate salt containing a large amount of calcium carbonate having a calcite crystal structure is used. That is, the calcium sulfonate salt used in the present embodiment is a calcium sulfonate salt containing calcium carbonate having a calcite crystal structure and having a calcium metal content of 2.0 to 12.0% by weight. Total Basic Number) is 15 to 500. A calcium sulfonate salt containing a large amount of calcium carbonate having a calcite crystal structure is superior in lubricating performance as compared to a calcium sulfonate salt containing a large amount of calcium carbonate having an aragonite crystal structure.

The content of the component G in the lubricating oil additive is 5% by weight to 30% by weight, and more preferably 10% by weight to 20% by weight.

[Method for producing lubricating oil additive]
Then, the manufacturing method of the lubricating oil additive which concerns on embodiment of this invention is demonstrated.

FIG. 1 is a flowchart showing an example of a method for producing a lubricating oil additive according to the present embodiment. The lubricant additive according to the embodiment of the present invention is manufactured by steps S1 to S3 (first step to third step) shown in FIG.

That is, first, in step S1 (first step), component A and component B are heated to about 50 ° C. or more and about 90 ° C. or less in a predetermined container and mixed (step S1). Next, in step S2 (second process), component C, component D, component E, and component F are mixed in this order with component A and component B mixed in step S1, and these components C to C are mixed in a predetermined container. F is dissolved (step S3). Then, after confirming the solubility in step S2, component G is further mixed in step S3 (third step) (step S3).

The lubricating oil additive according to this embodiment is manufactured through the first to third steps described above.

[Example]
Subsequently, examples of the lubricating oil additive according to the embodiment of the present invention will be described. Lubricating oil additives P1 to P4 according to this example are manufactured by blending the above components A to G in the proportions shown in Table 1 below. Note that the lubricating oil additive Sa as a reference example was prepared by blending the components A to G with the above component G being 0% by weight.

[First Comparative Example]
A first comparative example in which the lubricating oil additives P1 to P4 according to this example are added to a commercially available vehicle ATF (Automatic Transmission Fluid), CVTF (Continuous Variable Transmission Fluid), diesel engine oil, and suspension oil, These are shown in Tables 2 to 5, respectively.

In Tables 2 to 5, kinematic viscosity at 40 ° C. (unit: mm ² / s), kinematic viscosity at 100 ° C. (unit: mm ² / s), viscosity index, and known shell four-ball load resistance test The measured values are shown when the wear scar diameter (unit: mm) is measured. Hereinafter, each table will be described.

Table 2 shows conventional additives from other companies, lubricating oil additive Sa as a reference example, and lubricating oil additives P1 to P4 according to this example for ATF alone for commercial vehicles and ATF for commercial vehicles. Each shows a comparative example with the case where 7% of the total amount of ATF is added. The test conditions (rotation speed, load, time, temperature) of the shell four-ball load resistance test according to Table 2 are 1200 rpm, 294 N (30 kg), 60 minutes, and 75 ° C., respectively.

Table 3 shows the conventional additives for other companies, the lubricant additive Sa as a reference example, and the lubricant additives P1 to P4 according to the present embodiment for CVTF alone for commercial vehicles and CVTF for commercial vehicles. Each shows a comparative example with the case where 7% of the total amount of the CVTF is added. The test conditions (rotation speed, load, time, temperature) of the shell four-ball load resistance test according to Table 3 are 1200 rpm, 294 N (30 kg), 60 minutes, and 75 ° C., respectively.

In Table 4, a conventional diesel engine oil for a commercial vehicle, a conventional additive for other companies, a lubricating oil additive Sa as a reference example for the commercial diesel engine oil, and a lubricating oil addition according to this example A comparative example is shown in which each of the agents P1 to P4 is added at 10% of the total amount of the diesel engine oil. The test conditions (rotation speed, load, time, temperature) of the shell four-ball load resistance test according to Table 4 are 1200 rpm, 392 N (40 kg), 60 minutes, and 75 ° C., respectively.

In Table 5, the lubricating oil additive Sa as a reference example and the lubricating oil additives P1 to P4 according to the present embodiment are shown for the suspension oil for a commercial vehicle alone and the suspension oil for a commercial vehicle, respectively. The comparative example with the case where 10% of the total amount of suspension oil is added is shown. The test conditions (rotation speed, load, time, temperature) of the shell four-ball load resistance test according to Table 5 are 1200 rpm, 392 N (40 kg), 60 minutes, and 75 ° C., respectively.

As shown in Tables 2 to 5, when each of a plurality of types of lubricating oils having different uses is added with the lubricating oil additives P1 to P4 according to the present embodiment, conventional lubricating oils as additives and reference examples are added. It was found that the wear scar diameter when the shell four-ball load bearing test was performed was shorter than that before the addition, compared to the additive Sa. That is, it was found that excellent wear performance was achieved for each of a plurality of types of lubricating oils having different applications.

It should be noted that the effect is particularly apparent when the component G, that is, the calcium sulfonate salt containing calcium carbonate having a calcite crystal structure is 5.0 wt% or more and 30.0 wt%. This is because when the component G is larger than 5.0% by weight, the wear scar diameter of the shell four-ball wear test is remarkably small and the wear resistance performance is improved as compared with the case where the component G is 0.0% by weight. . In addition, when the component G is 10.0% by weight, the wear scar diameter of the shell four-ball wear test is shorter than when the component G is 5.0% by weight, and when the component G is 20.0% by weight. However, the wear scar diameter is the same or short. On the other hand, when the component G is 30.0% by weight, the numerical value of the wear scar diameter in the shell four-ball wear test is the same or longer when the component G is 20.0% by weight. Thus, when the lubricating oil additives P1 to P4 according to the present embodiment are added to each of a plurality of types of lubricating oils having different uses, the content of the component G is more preferably based on the results of the shell four-ball wear test. Is from 10.0% to 20.0% by weight.

In addition, when the lubricant additive according to this example was added to CVTF, the secondary effect that the judder of the vehicle clutch that had occurred before the addition was eliminated was obtained as a plurality of examples.

[Second Comparative Example]
Table 6 shows a second comparative example in which the lubricating oil additive according to this example was added to a commercially available gear oil for industrial machinery.

In Table 6, kinematic viscosity at 40 ° C. (unit: mm ² / s), kinematic viscosity at 100 ° C. (unit: mm ² / s), viscosity index, and well-known shell four-ball load resistance test The measured value when the wear scar diameter (unit: mm) is measured is shown.

In Table 6, the lubricating oil additive Sa as a reference example and the lubricating oil additives P1 to P4 according to the present example were added to the commercially available gear oil for industrial machinery and the commercially available gear oil for industrial machinery. The comparative example with the case where 10% of the total amount is added is shown. The test conditions (rotation speed, load, time, temperature) of the shell four-ball load resistance test according to Table 6 are 1200 rpm, 392 N (40 kg), 60 minutes, and 75 ° C., respectively.

As shown in Table 6, when the lubricating oil additives P1 to P4 according to this example are added to the gear oil for industrial machinery, the shell four-ball load capacity is compared with the lubricating oil additive Sa as a reference example. It was found that the wear scar diameter during the test was shorter than that before the addition. That is, it was found that excellent wear performance was achieved for gear oil for industrial machinery. The effect is particularly apparent when the component G, that is, the calcium sulfonate salt containing calcium carbonate having a calcite crystal structure is 5.0 wt% or more and 30.0 wt%.

[Third comparative example]
Table 7 shows a third comparative example in which the lubricant additive according to the present example is added to the predetermined first base oil.

In Table 7, the comparative example at the time of adding 10% of the total amount of the said 1st base oil to the lubricating oil additive P2 which concerns on a present Example with respect to a commercially available 1st base oil and a commercially available 1st base oil is shown. Yes. Specifically, a ratio of measured values of operating time La (unit: h) until bearing failure to bearing theoretical life time Lo (unit: h) when a life evaluation test of a thrust ball bearing based on the Weibull distribution is performed ( (Unit: dimensionless) and calculated values (unit: dimensionless) of La (actual measured value) / La (measured value of only the first base oil) are shown. The test conditions (thrust ball bearing, rotation speed, load) of the bearing life evaluation test according to Table 7 are # 51104, 750 rpm, and 4.4 kN, respectively.

As shown in Table 7, by adding the lubricating oil additive P2 according to the present embodiment, in addition to the improvement of the viscosity index as described above, the bearing life time is 4.67 times and a large performance improvement is realized. I understood.

[Fourth Comparative Example]
Table 8 shows a fourth comparative example in which the lubricant additive according to this example is added to the predetermined second base oil.

In Table 8, the comparative example at the time of adding 10% of the total amount of the said 2nd base oil to the lubricating oil additive P2 which concerns on a present Example with respect to a commercially available 2nd base oil and a commercially available 2nd base oil is shown. Yes. Specifically, a ratio of measured values of operating time La (unit: h) until bearing failure to bearing theoretical life time Lo (unit: h) when a life evaluation test of a thrust ball bearing based on the Weibull distribution is performed ( Unit: dimensionless), La (actual measured value) / La (measured value of the second base oil only) calculated value (unit: dimensionless), power reduction rate when using added oil relative to base oil power Show. The test conditions (thrust ball bearing, rotation speed, load) of the bearing life evaluation test according to Table 8 are # 51104, 750 rpm, and 4.4 kN, respectively.

As shown in Table 8, by adding the lubricating oil additive P2 according to this example, in addition to the improvement of the viscosity index as described above, the bearing life time is 14.50 times and the power reduction rate is 8 %, And it was found that a significant performance improvement was realized.

As described above, according to the embodiment of the present invention and the lubricating oil additive according to the examples, the lubricating oil additive can be comprehensively applied to vehicle lubricating oil and industrial lubricating oil (excluding metal processing oil). . Therefore, when the user tries to apply lubricating oil to each device of the vehicle, it solves the problem that a lubricating oil additive must be prepared for each device, and at the same time achieves both energy saving and resource saving that are currently required by society Can be aimed at improving the global environment.

Although one embodiment of the present invention has been described above, the above embodiment shows one example of application of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. is not.

Claims

A lubricating oil additive added to the lubricating oil,
A polyol ester synthetic base oil;
A sulfonic acid calcium salt containing calcium carbonate having a calcite crystal structure;
A poly α-olefin oligomer, a zinc dithiophosphate antioxidant, a succinimide, a thiadiazole extreme pressure agent, a phenol antioxidant,
A lubricating oil additive comprising:
The content of the polyol ester synthetic base oil in the lubricating oil additive is 35.0 wt% or more and 60.0 wt% or less,
The lubricating oil additive according to claim 1, wherein the content of the calcium sulfonate in the lubricating oil additive is 5.0 wt% or more and 30.0 wt% or less.
2. The lubricating oil additive according to claim 1, wherein the polyol ester-based synthetic base oil contains a linear saturated fatty acid having 8 to 18 carbon atoms.
The lubricating oil additive according to claim 1, wherein the polyol ester-based synthetic base oil contains tri (caprylic acid / capric acid) trimethylolpropane.
The lubricating oil additive according to claim 1, wherein the poly α-olefin oligomer has a three-dimensional structure produced using a metallocene catalyst.
The lubricating oil additive according to claim 1, wherein the content of the poly α-olefin oligomer in the lubricating oil additive is 10.0 wt% or more and 50.0 wt% or less.
The lubricating oil additive according to claim 1, wherein the zinc dithiophosphate antioxidant includes an antioxidant mainly composed of zinc dithiophosphate having a primary alkyl group.
The lubricating oil additive according to claim 7, wherein the zinc dithiophosphate contains zinc 2-ethylhexyl dithiophosphate.
The lubricating oil additive according to claim 1, wherein the content of the zinc dithiophosphate antioxidant in the lubricating oil additive is 0.5 wt% or more and 3.0 wt% or less.
The lubricating oil additive according to claim 1, wherein the succinimide contains polyisobutenyl succinimide.
The lubricating oil additive according to claim 1, wherein the content of the succinimide in the lubricating oil additive is 3.0 wt% or more and 10.0 wt% or less.
The thiadiazole extreme pressure agent includes 2,5-dimercapto-1,3,4-thiadiazole, 4,5-dimercaptothiadiazole, 3,5-dimercapto-1,2,4-thiadiazole, and 3,4-dimercapto The lubricating oil additive according to claim 1, comprising at least one selected from the group consisting of -1,2,5-thiadiazole.
The lubricating oil additive according to claim 1, wherein a content of the thiadiazole extreme pressure agent in the lubricating oil additive is 1.0 wt% or more and 6.0 wt% or less.
The lubricating oil additive according to claim 1, wherein the phenol-based antioxidant contains 2.6-di-tert-butyl-4-methylphenol.
The lubricating oil additive according to claim 1, wherein the content of the phenolic antioxidant in the lubricating oil additive is 0.1 wt% or more and 2.0 wt% or less.
A method for producing a lubricating oil additive to be added to a lubricating oil, comprising:
A first step of heating and mixing the polyol ester-based synthetic base oil and the polyα-olefin oligomer in a predetermined container at 50 ° C. or higher and 90 ° C. or lower;
The product produced by mixing in the first step is mixed with a zinc dithiophosphate antioxidant, a succinimide, a thiadiazole extreme pressure agent, and a phenol antioxidant, and dissolved in the product. A second step of
A third step of mixing the product produced by mixing in the second step with a calcium sulfonate salt containing calcium carbonate having a calcite crystal structure;
A method for producing a lubricating oil additive, comprising: