CN115074175A

CN115074175A - Low-friction diesel engine oil and preparation method thereof

Info

Publication number: CN115074175A
Application number: CN202210722922.8A
Authority: CN
Inventors: 李乐; 乔小兵; 桃春生; 王清国; 许扬; 蒋惠宇; 刘茜
Original assignee: FAW Jiefang Automotive Co Ltd
Current assignee: FAW Jiefang Automotive Co Ltd
Priority date: 2022-06-24
Filing date: 2022-06-24
Publication date: 2022-09-20
Anticipated expiration: 2042-06-24
Also published as: CN115074175B

Abstract

The invention relates to low-friction diesel engine oil and a preparation method thereof. The low friction diesel engine oil comprises, by mass, 70-85% of base oil, 2-15% of viscosity index agent, 0.1-2% of friction modifier, 3-18% of complexing agent and 0.1-1% of pour point depressant. Wherein, the friction modifier comprises organic molybdenum, organic ester and nano particles accounting for 70 to 78 percent, 20 to 25 percent and 0.01 to 10 percent of the weight percentage of the friction modifier respectively. In the low-friction diesel engine oil, the friction modifier obtained by compounding the organic molybdenum, the organic ester and the nanoparticles can form a friction film on the surface of a friction pair, so that the friction and wear performance of the diesel engine oil is improved, and the friction coefficient of the diesel engine oil is reduced. Meanwhile, in the diesel engine oil, the proper viscosity grade of the diesel engine oil can be kept through the proportion of the raw materials, and the service performance of the diesel engine oil is kept.

Description

Low-friction diesel engine oil and preparation method thereof

Technical Field

The invention relates to the technical field of lubricating oil, in particular to low-friction diesel engine oil and a preparation method thereof.

Background

With the stricter diesel engine oil consumption regulation and emission regulation, the stricter requirements on energy conservation and emission reduction are required in the development of diesel engine technology. In order to reduce the fuel consumption and emission of vehicles, in addition to upgrading the engine, it is an effective means to improve the diesel engine oil. The traditional diesel oil has larger space for improvement in the aspects of maintaining viscosity grade, reducing friction and the like.

Disclosure of Invention

Based on the above, there is a need for a diesel engine oil with a low friction coefficient while maintaining a suitable viscosity grade, and a method for preparing the same.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a low-friction diesel engine oil is prepared from the following raw materials in percentage by mass:

70 to 85 percent of base oil,

2 to 15 percent of viscosity index agent,

0.1 to 2 percent of friction modifier,

3% to 18% of complexing agent, and

0.1 to 1 percent of pour point depressant;

wherein the friction modifier comprises, by mass percent, 70-78% of organic molybdenum, 20-25% of organic ester and 0.01-10% of nano particles.

In one embodiment, the organomolybdenum is molybdenum dialkyldithiocarbamate.

In one embodiment, the organic ester is a dithioalkyl borate.

In one embodiment, the nanoparticle is graphene-TiO ₂ Composite nanoparticles.

In one embodiment, the base oil comprises 80% to 95% polyalphaolefin and 5% to 20% diester base oil, as a mass percentage of the base oil.

In one embodiment, the poly alpha-olefin comprises the following components in a mass ratio of (1.5-2.5): (0.8-1.2): 1 PAO4, PAO6, and PAO 8.

In one embodiment, the diester base oil has a pour point of ≧ 60 ℃.

In one embodiment, the diester base oil has a viscosity index ≧ 160.

In one embodiment, the viscosity index agent comprises 50-60% of ethylene propylene copolymer and 40-50% of polymethacrylate in percentage by mass.

In one embodiment, the ethylene propylene copolymer has a molar ethylene content of 45% to 55%.

In one embodiment, the complexing agent comprises 18-25% of alkyl salicylate, 10-15% of sulfonate, 25-35% of boronized polyisobutylene succinimide, 15-25% of zinc dialkyl dithiophosphate, 8-13% of 2, 6-di-tert-butyl-p-cresol, 3-6% of tolyltriazole and 1-3% of dimethyl silicone oil by mass percentage of the complexing agent.

In one embodiment, the pour point depressant is at least one of a poly-alpha olefin and a polymethacrylate.

A method for preparing a low friction diesel engine oil as described in any of the above embodiments, comprising the steps of:

mixing the base oil, the viscosity index agent, the complexing agent and the pour point depressant to prepare a mixture;

mixing the friction modifier with the compound.

In one embodiment, when the base oil, the viscosity index agent, the complexing agent and the pour point depressant are mixed, the mixing temperature is controlled to be 60-70 ℃; and when the friction modifier is mixed with the mixture, controlling the mixing temperature to be 75-80 ℃.

The raw materials of the low-friction diesel engine oil comprise, by mass, 70-85% of base oil, 2-15% of viscosity index agent, 0.1-2% of friction modifier, 3-18% of complexing agent and 0.1-1% of pour point depressant. Wherein, the friction modifier comprises organic molybdenum, organic ester and nano particles accounting for 70 to 78 percent, 20 to 25 percent and 0.01 to 10 percent of the weight percentage of the friction modifier respectively. In the low-friction diesel engine oil, the friction modifier obtained by compounding the organic molybdenum, the organic ester and the nanoparticles can form a friction film on the surface of a friction pair, so that the friction and wear performance of the diesel engine oil is improved, and the friction coefficient of the diesel engine oil is reduced. Meanwhile, in the diesel engine oil, the proper viscosity grade of the diesel engine oil can be kept through the proportion of the raw materials, and the service performance of the diesel engine oil is kept.

In the preparation method of the low-friction diesel engine oil, the base oil, the viscosity index agent, the complexing agent and the pour point depressant are mainly mixed to prepare a mixture; the friction modifier is then mixed with the mix. The preparation method is simple and feasible, and is suitable for large-scale popularization.

Detailed Description

The present invention will be described in detail with reference to the following embodiments in order to make the aforementioned objects, features and advantages of the invention more comprehensible. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

One embodiment of the invention provides a low-friction diesel engine oil. The low-friction diesel engine oil is prepared from the following raw materials in percentage by mass: 70-85% of base oil, 2-15% of viscosity index agent, 0.1-2% of friction modifier, 3-18% of complexing agent and 0.1-1% of pour point depressant. Wherein the friction modifier comprises 70-78% of organic molybdenum, 20-25% of organic ester and 0.01-10% of nano particles in percentage by mass of the friction modifier. In the low-friction diesel engine oil, the friction modifier obtained by compounding the organic molybdenum, the organic ester and the nanoparticles can form a friction film on the surface of a friction pair, so that the friction and wear performance of the diesel engine oil is improved, and the friction coefficient of the diesel engine oil is reduced. Meanwhile, in the diesel engine oil, the proper viscosity grade of the diesel engine oil can be kept through the proportion of the raw materials, and the service performance of the diesel engine oil is kept.

Furthermore, when the low-friction diesel engine oil is used, the nano particles can repair the worn position, reduce the surface scratches of the friction surface and maintain the stability of the friction pair.

Further, current OEM truck oils for diesel fuel are available in the 10W/40 and 5W/30 major viscosity grades. In the embodiment, the viscosity grade of the low-friction diesel engine oil can be 0W/20 or 5W/20 through the proportion of the raw materials, and the fuel economy is improved for consumers at lower cost.

In the present embodiment, the viscosity grade of the low friction diesel engine oil is 0W/20 or 5W/20. 150 ℃ of low-friction diesel engine oil ⁶ s ^-1 The high-temperature high-shear viscosity of the rubber is more than or equal to 2.6 mPas. The low-friction diesel engine oil has a kinematic viscosity range of 6.9mm at 100 DEG C ² /s～9.3mm ² And s. The low-friction diesel engine oil has a longer oil change period, and the oil change mileage is more than or equal to 10 kilometers.

In one specific example, the low friction diesel engine oil is prepared from the following raw materials in percentage by mass: 70-85% of base oil, 2-15% of viscosity index agent, 0.1-2% of friction modifier, 3-18% of complexing agent and 0.1-1% of pour point depressant. Wherein the friction modifier comprises 70-78% of organic molybdenum, 20-25% of organic ester and 0.01-10% of nano particles in percentage by mass of the friction modifier.

Alternatively, the base oil may be 70%, 72%, 75%, 78%, 80%, 82%, 85%, etc. in mass percent based on the low friction diesel engine oil. It is understood that the base oil may be selected from the range of 70% to 85% by weight.

Alternatively, the viscosity index agent may be 2%, 5%, 7%, 8%, 10%, 12.5%, 15%, or the like, in mass percent based on the low friction diesel engine oil. It is understood that the viscosity index agent may be selected from a range of 2% to 15% by weight.

Alternatively, the friction modifier may be present in a mass percent of 0.1%, 0.5%, 1%, 1.5%, 2%, etc. as a mass percent of the low friction diesel engine oil. It is understood that the friction modifier may be selected from the range of 0.1% to 2% by weight.

Alternatively, the mass percent of the complexing agent may be 3%, 5%, 7%, 10%, 12%, 13.5%, 15%, 18%, or the like, as a mass percent of the low friction diesel engine oil. It is understood that the mass percent of the complexing agent can be selected from 3% to 18%.

Alternatively, the pour point depressant may be 0.1, 0.2, 0.5, 0.8, 1, etc. mass percent based on the mass percent of the low friction diesel engine oil. It is understood that the mass percent of the pour point depressant can be selected from 0.1 to 1 percent.

Alternatively, the mass percent of the organo-molybdenum may be 70%, 73%, 75%, 78%, or the like, as a mass percent of the friction modifier. It is understood that the mass percent of the organic molybdenum can be selected from 70% to 78%.

Alternatively, the organic ester may be present in a mass percent of 20%, 22%, 25%, etc., based on the mass percent of the friction modifier. It is understood that the mass percent of the organic ester may be selected from the range of 20% to 25%.

Alternatively, the mass percent of the nanoparticles may be 0.01%, 1%, 3%, 5%, 8%, 10%, or the like, as a mass percent of the friction modifier. It is understood that the mass percent of the nanoparticles may be selected from 0.01% to 10%.

In one particular example, the organomolybdenum is molybdenum dialkyldithiocarbamate. The organic ester is dithioalkyl borate. The nano particles are graphene-TiO ₂ Composite nanoparticles.

Alternatively, graphene-TiO ₂ The composite nanoparticles are prepared by a hydrothermal method. In particular, graphene-TiO ₂ The preparation method of the composite nano-particle comprises the following steps: mixing TiO with ₂ Mixing the graphene and alkali liquor to obtain a first dispersion liquid; heating the first dispersion liquid to obtain a second dispersion liquid; mixing the second dispersion with an acid solution to obtain a third dispersion; and carrying out solid-liquid separation treatment on the third dispersion liquid, and roasting the obtained solid product.

Specifically, the alkali solution is sodium hydroxide solution, potassium hydroxide solution, etc. TiO 2 ₂ And the mass ratio of the graphene to the graphene is 100: 3-100: 1. The temperature of the heating treatment is 150-200 ℃. The time of the heating treatment is 40-50 h. The acid solution is concentrated hydrochloric acid. The solid-liquid separation treatment adopts filtration, centrifugation and the like. The temperature of the roasting treatment is 300-500 ℃. The time of roasting treatment is 1.5-3 h.

More specifically, the concentration of the alkali liquor is 5 mol/L-10 mol/L. TiO 2 ₂ And graphene in a mass ratio of 100: 2. The temperature of the heat treatment was 180 ℃. The time for the heat treatment was 48 hours. The heat treatment is carried out in a hydrothermal reaction kettle. The temperature of the calcination treatment was 400 ℃. The time of the roasting treatment is 2 hours. The calcination treatment is carried out in a tube furnace.

It will be appreciated that the first dispersion may be subjected to a heat treatment followed by a cooling rinse step prior to mixing the second dispersion with the acid solution.

In one specific example, graphene-TiO ₂ The preparation method of the composite nano-particle comprises the following steps: adding TiO into the mixture ₂ And adding graphene into 10mol/L NaOH solution, and adding TiO ₂ And the graphene is stirred until the graphene and the graphene are uniformly dispersed to obtain a first dispersion liquid, wherein the mass ratio of the graphene to the graphene is 100: 2. And adding the first dispersion into a hydrothermal reaction kettle, and keeping the temperature at 180 ℃ for 48 hours to obtain a second dispersion. And cooling and cleaning the second dispersion, and then adding concentrated hydrochloric acid and stirring for 2 hours to obtain a third dispersion. Filtering the third dispersion liquid, and roasting the obtained solid product in a tubular furnace at 400 ℃ for 2 hours to obtain graphene-TiO ₂ Composite nanoparticles.

In a particular example, the base oil comprises, in mass percent of the base oil, 80% to 95% polyalphaolefin and 5% to 20% diester base oil. The low-temperature performance of the diesel engine oil can be effectively improved by matching the poly-alpha-olefin with the diester base oil. Meanwhile, the matching of the poly-alpha-olefin and the diester base oil can improve the solubility of other raw materials in the diesel engine oil in the base oil and improve the uniformity and the comprehensive performance of the diesel engine oil.

Alternatively, the mass percent of the polyalphaolefin, as a mass percent of the base oil, can be 80%, 85%, 90%, or 95%. It is understood that the weight percent of the polyalphaolefin may be selected from the range of 80% to 95%.

Alternatively, the weight percent of the diester base oil may be 5%, 10%, 15%, or 20% as a weight percent of the base oil. It is understood that the weight percentage of the diester base oil may be selected from 5% to 20%.

In a specific example, as an example of the poly α olefin, the poly α olefin includes, in a mass ratio of (1.5 to 2.5): (0.8-1.2): 1 PAO4, PAO6, and PAO 8. Preferably, the mass ratio of the PAO4, the PAO6 and the PAO8 is 2: 2: 1. as an example of choice for the diester base oil, the diester base oil has a pour point of ≧ 60 ℃. The viscosity index of the diester base oil is more than or equal to 160.

In a specific example, the viscosity index agent comprises 50-60% of ethylene propylene copolymer and 40-50% of polymethacrylate in percentage by mass. Further, the ethylene-propylene copolymer has an ethylene molar content of 45 to 55%. Further, the ethylene propylene copolymer had an ethylene molar content of 49%. The ethylene-propylene copolymer has an ethylene molar content of 49%, and can limit the crystallization of the ethylene chain segment to a greater extent, so that the low-temperature performance of the diesel engine oil is further improved.

Alternatively, the ethylene propylene copolymer may be present in a mass percent of 50%, 52%, 55%, 58% or 60% by mass of the viscosity index agent. It will be appreciated that the mass percentage of the ethylene propylene copolymer may be suitably selected within the range of 50% to 60%.

Alternatively, the mass percentage of polymethacrylate may be 40%, 42%, 45%, 48%, or 50% as a mass percentage of the viscosity index agent. It is understood that the mass percent of polymethacrylate can be selected from the range of 40% to 50%.

In a specific example, the complexing agent comprises 18-25% of alkyl salicylate, 10-15% of sulfonate, 25-35% of boronized polyisobutylene succinimide, 15-25% of zinc dialkyl dithiophosphate, 8-13% of 2, 6-di-tert-butyl-p-cresol, 3-6% of tolyltriazole and 1-3% of dimethyl silicone oil in percentage by mass of the complexing agent.

Alternatively, the mass percentage of the alkyl salicylate can be 18%, 20%, 22%, 24% or 25% by mass of the complexing agent, and it is understood that the mass percentage of the alkyl salicylate can be selected from 18% to 25% by mass.

Alternatively, the mass percentage of the sulfonate may be 10%, 12%, 14% or 15% by mass of the complexing agent, it being understood that the mass percentage of the sulfonate may be selected from the range of 10% to 15% by mass.

Alternatively, the mass percent of the boronated polyisobutylene succinimide may be 25%, 28%, 30%, 32%, or 35% by mass of the complexing agent, it being understood that the mass percent of the boronated polyisobutylene succinimide may be in the range of 25% to 35% by mass of the complexing agent, as well as other suitable choices.

Alternatively, the zinc dialkyl dithiophosphate may be in a mass percent of 15%, 18%, 20%, 22% or 25% by mass of the complexing agent, it being understood that the mass percent of zinc dialkyl dithiophosphate may be selected to be in the range of 15% to 25% by mass.

Alternatively, the mass percent of 2, 6-di-tert-butyl-p-cresol may be 8%, 10%, 11% or 13% by mass of the complexing agent, it being understood that the mass percent of 2, 6-di-tert-butyl-p-cresol may be in the range of 8% to 13% by mass.

Alternatively, the mass percent of tolyltriazole may be 3%, 4%, 5% or 6% by mass of the complexing agent, it being understood that tolyltriazole may be suitably selected within the range of 3% to 6% by mass.

Alternatively, the mass percent of the simethicone can be 1%, 2% or 3% based on the mass percent of the complexing agent, and it is understood that the mass percent of the simethicone can be selected from 1% to 3% in other suitable manners.

In a specific example, the complexing agent comprises 24% by mass of alkyl salicylate, 12% by mass of sulfonate, 28% by mass of boronated polyisobutylene succinimide, 18% by mass of zinc dialkyldithiophosphate, 11% by mass of 2, 6-di-tert-butyl-p-cresol, 5% by mass of tolyltriazole and 2% by mass of dimethicone, respectively, based on the mass of the complexing agent.

In a particular example, the pour point depressant is at least one of a poly-alpha olefin and a polymethacrylate. Preferably, the pour point depressant is a poly-alpha olefin or a polymethacrylate.

The invention also provides a preparation method of the low-friction diesel engine oil. The preparation method of the low-friction diesel engine oil comprises the following steps: mixing base oil, a viscosity index agent, a complexing agent and a pour point depressant to prepare a mixture; the friction modifier is mixed with the mix. In the preparation method, the base oil, the viscosity index agent, the complexing agent and the pour point depressant are mixed to prepare a mixture; the friction modifier is then mixed with the mix. The preparation method is simple and feasible, and is suitable for large-scale popularization.

It can be understood that, in the preparation method of the low-friction diesel engine oil, the base oil, the viscosity index agent, the complexing agent and the pour point depressant are mixed in a blending kettle to prepare a mixture; then adding a friction modifier and mixing the friction modifier with the mixture.

In one specific example, the method further comprises the following steps after mixing the friction modifier with the mixture: the mixture obtained by mixing was subjected to filtration treatment.

Further, the method comprises the following steps after the friction modifier is mixed with the mixture and before the mixture obtained after mixing is subjected to filtration treatment: and (4) standing the mixture obtained by mixing. Optionally, the standing time is 1.5-2.5 h. Specifically, the standing time is 2 hours.

In one specific example, when the base oil, the viscosity index agent, the complexing agent, and the pour point depressant are mixed, the mixing temperature is controlled to be 60 ℃ to 70 ℃. Alternatively, the mixing temperature is 60 ℃, 62 ℃, 65 ℃, 68 ℃ or 70 ℃. It will be appreciated that the mixing temperature may be suitably selected within the range of 60 ℃ to 70 ℃.

Further, when the friction modifier is mixed with the mixture, the mixing temperature is controlled to be 75-80 ℃. For example, the mixing temperature is 75 ℃, 78 ℃ or 80 ℃. It is understood that the mixing temperature may be selected to be within the range of 75 deg.C to 80 deg.C.

Further, when the base oil, the viscosity index agent, the complexing agent and the pour point depressant are mixed, the mixing time is controlled to be 1.5-2.5 h. Specifically, the mixing time is 2 h.

Further, when the friction modifier is mixed with the mixture, the mixing time is controlled to be 3-5 h. Specifically, the mixing time is 4 h.

In one specific example, the mixing is by way of stirring.

In one particular example, a method of making a base oil comprises the steps of: mixing 80-95% of poly alpha-olefin and 5-20% of diester base oil at 60-70 ℃ in percentage by mass of the base oil. Optionally, the mixing time is 1.5h to 2.5 h. Specifically, the mixing time is 2 h.

The following are specific examples.

Example 1

The raw materials of the low friction diesel engine oil in the embodiment are as follows: the low-friction diesel engine oil comprises, by mass, 75% of base oil, 10% of viscosity index agent, 1% of friction modifier, 13.5% of complexing agent and 0.5% of pour point depressant. The friction modifier comprises 73 mass percent of molybdenum dialkyl dithiocarbamate, 22 mass percent of dithio alkyl borate and 5 mass percent of graphene-TiO ₂ Composite nano particles.

Wherein the base oil comprises 95% of poly alpha-olefin and 5% of diester base oil by mass percent of the base oil. The poly alpha-olefin is prepared from the following components in a mass ratio of 2: 2: 1 PAO4, PAO6, and PAO 8. The pour point of the diester base oil is more than or equal to-60 ℃, and the viscosity index of the diester base oil is more than or equal to 160. The viscosity index agent comprises 60 percent of ethylene propylene copolymer and 40 percent of polymethacrylate in percentage by mass. The ethylene propylene copolymer had a molar ethylene content of 49%. The compound agent comprises 24 percent of alkyl salicylate, 12 percent of sulfonate, 28 percent of boronized polyisobutylene succinimide, 18 percent of zinc dialkyl dithiophosphate, 11 percent of 2, 6-di-tert-butyl-p-cresol, 5 percent of tolyltriazole and 2 percent of dimethyl silicone oil by mass percent. The pour point depressant is a poly-alpha olefin.

Wherein the content of the first and second substances,graphene-TiO ₂ The preparation method of the composite nano-particle comprises the following steps: adding TiO into the mixture ₂ And adding graphene into 10mol/L NaOH solution, and adding TiO ₂ And the graphene is stirred until the graphene and the graphene are uniformly dispersed to obtain a first dispersion liquid, wherein the mass ratio of the graphene to the graphene is 100: 2. And adding the first dispersion into a hydrothermal reaction kettle, and keeping the temperature at 180 ℃ for 48 hours to obtain a second dispersion. And cooling and cleaning the second dispersion, and then adding concentrated hydrochloric acid and stirring for 2 hours to obtain a third dispersion. Filtering the third dispersion liquid, and roasting the obtained solid product in a tubular furnace at 400 ℃ for 2 hours to obtain graphene-TiO ₂ Composite nanoparticles.

The preparation method of the low-friction diesel engine oil in the embodiment comprises the following steps:

s101: adding the poly-alpha-olefin and the diester base oil into a blending kettle, and mixing for 2 hours at 65 ℃ to obtain the base oil.

S102: adding the complexing agent, the viscosity index agent and the pour point depressant into a blending kettle, and mixing for 2 hours at 65 ℃ to obtain a mixture.

S103: the friction modifier was added to the kettle and mixed at 75 ℃ for 4 h.

S104: and standing the mixture obtained in the step S103 for 2 hours, and then filtering to obtain the low-friction diesel engine oil.

Example 2

The raw materials of the low friction diesel engine oil in the embodiment are as follows: the low-friction diesel engine oil comprises, by mass, 80% of base oil, 8% of viscosity index agent, 1.5% of friction modifier, 10% of complexing agent and 0.5% of pour point depressant. The friction modifier comprises 70 percent of molybdenum dialkyl dithiocarbamate, 25 percent of dithio alkyl borate and 5 percent of graphene-TiO in percentage by mass ₂ Composite nano particles.

Wherein the base oil comprises 85% of poly alpha-olefin and 15% of diester base oil by mass percent of the base oil. The poly alpha-olefin is prepared from the following components in a mass ratio of 2: 2: 1 PAO4, PAO6, and PAO 8. The pour point of the diester base oil is more than or equal to-60 ℃, and the viscosity index of the diester base oil is more than or equal to 160. The viscosity index agent comprises 50% of ethylene propylene copolymer and 50% of polymethacrylate in percentage by mass of the viscosity index agent. The ethylene propylene copolymer had an ethylene molar content of 49%. The compound agent comprises 24 percent of alkyl salicylate, 12 percent of sulfonate, 28 percent of boronized polyisobutylene succinimide, 18 percent of zinc dialkyl dithiophosphate, 11 percent of 2, 6-di-tert-butyl-p-cresol, 5 percent of tolyltriazole and 2 percent of dimethyl silicone oil by mass percent. The pour point depressant is polymethacrylate.

Wherein, the graphene-TiO ₂ The preparation method of the composite nano-particle comprises the following steps: adding TiO into the mixture ₂ And adding graphene into 10mol/L NaOH solution, and adding TiO ₂ And the graphene is stirred until the graphene and the graphene are uniformly dispersed to obtain a first dispersion liquid, wherein the mass ratio of the graphene to the graphene is 100: 2. And adding the first dispersion into a hydrothermal reaction kettle, and keeping the temperature at 180 ℃ for 48 hours to obtain a second dispersion. And cooling and cleaning the second dispersion, and then adding concentrated hydrochloric acid and stirring for 2 hours to obtain a third dispersion. Filtering the third dispersion liquid, and roasting the obtained solid product in a tubular furnace at 400 ℃ for 2 hours to obtain graphene-TiO ₂ Composite nanoparticles.

Example 3

The raw materials of the low friction diesel engine oil in the embodiment are as follows: the low-friction diesel engine oil comprises, by mass, 70% of base oil, 12.5% of viscosity index agent, 2% of friction modifier, 15% of complexing agent and 0.5% of pour point depressant. The friction modifier is composed of 70% of twoMolybdenum alkyl dithiocarbamate, 22% of dithioalkyl borate and 8% of graphene-TiO ₂ Composite nano particles.

Wherein the base oil comprises 80% of poly-alpha-olefin and 20% of diester base oil by mass percent of the base oil. The poly alpha-olefin is prepared from the following components in a mass ratio of 2: 2: 1 PAO4, PAO6, and PAO 8. The pour point of the diester base oil is more than or equal to-60 ℃, and the viscosity index of the diester base oil is more than or equal to 160. The viscosity index agent comprises 55% of ethylene propylene copolymer and 45% of polymethacrylate in percentage by mass of the viscosity index agent. The ethylene propylene copolymer had a molar ethylene content of 49%. The compound agent comprises 24 percent of alkyl salicylate, 12 percent of sulfonate, 28 percent of boronized polyisobutylene succinimide, 18 percent of zinc dialkyl dithiophosphate, 11 percent of 2, 6-di-tert-butyl-p-cresol, 5 percent of tolyltriazole and 2 percent of dimethyl silicone oil by mass percent. The pour point depressant is a poly-alpha olefin.

Example 4

The raw materials of the low friction diesel engine oil in the embodiment are as follows: calculated by mass percent of the low-friction diesel engine oil, 85 percent of base oil, 7 percent of viscosity index agent, 0.5 percent of friction improver, 7 percent of complexing agent and 0.5 percent of pour point depressant. The friction modifier comprises 77 percent of molybdenum dialkyl dithiocarbamate, 22 percent of dithio alkyl borate and 1 percent of graphene-TiO by mass percent of friction modifier ₂ Composite nano particles.

Wherein the base oil comprises 90% of poly alpha-olefin and 10% of diester base oil by mass percent of the base oil. The poly alpha-olefin is prepared from the following components in a mass ratio of 2: 2: 1 PAO4, PAO6, and PAO 8. The pour point of the diester base oil is more than or equal to minus 60 ℃, and the viscosity index of the diester base oil is more than or equal to 160. The viscosity index agent comprises 58% of ethylene propylene copolymer and 42% of polymethacrylate in percentage by mass. The ethylene propylene copolymer had a molar ethylene content of 49%. The compound agent comprises 24 percent of alkyl salicylate, 12 percent of sulfonate, 28 percent of boronized polyisobutylene succinimide, 18 percent of zinc dialkyl dithiophosphate, 11 percent of 2, 6-di-tert-butyl-p-cresol, 5 percent of tolyltriazole and 2 percent of dimethyl silicone oil by mass percent. The pour point depressant is polymethacrylate.

Test example

(1) The low friction diesel engine oils obtained in examples 1 to 4 and the diesel engine oil in the comparative example were tested for friction coefficient on an SRV4 type friction wear tester, respectively. Wherein the diesel engine oil in the comparative example was a 10W/40CK-4 grade diesel engine oil. The test results are shown in table 1.

TABLE 1

	Comparative example	Example 1	Example 2	Example 3	Example 4
						Average coefficient of friction of SRV	0.172	0.127	0.135	0.115	0.142

As can be seen from Table 1, the friction coefficients of the diesel engine oils of examples 1 to 4 were all lower than those of the comparative example.

(2) The diesel engine oils in examples 1 to 4 and comparative examples were subjected to operational verification on a liberation weight truck to examine the actual energy saving effect. The test results are shown in table 2. The oil consumption reduction rate of the whole vehicle is referred to the comparative example.

	Comparative example	Example 1	Example 2	Example 3	Example 4
						Overall fuel consumption reduction rate/%)	-	2.12	2.01	2.66	1.83

As can be seen from Table 1, the diesel engine oils of examples 1 to 4 have a good fuel saving effect.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the patent of the invention is subject to the appended claims, and the description can be used for explaining the contents of the claims.

Claims

1. The low-friction diesel engine oil is characterized by being prepared from the following raw materials in percentage by mass:

70 to 85 percent of base oil,

2 to 15 percent of viscosity index agent,

0.1 to 2 percent of friction modifier,

3% to 18% of complexing agent, and

0.1 to 1 percent of pour point depressant;

2. The low friction diesel engine oil of claim 1, wherein the organomolybdenum is molybdenum dialkyldithiocarbamate; and/or the presence of a gas in the gas,

the organic ester is dithioalkyl borate; and/or the presence of a gas in the gas,

the nano particles are graphene-TiO ₂ Composite nanoparticles.

3. The low friction diesel engine oil of claim 1, wherein the base oil comprises 80-95% polyalphaolefin and 5-20% diester base oil by mass of the base oil.

4. The low friction diesel engine oil of claim 3, wherein the poly-alpha-olefin comprises, by mass, a ratio of (1.5-2.5): (0.8-1.2): PAO4, PAO6, and PAO8 of 1; and/or the presence of a gas in the gas,

the pour point of the diester base oil is more than or equal to-60 ℃; and/or the presence of a gas in the gas,

the viscosity index of the diester base oil is more than or equal to 160.

5. The low friction diesel engine oil according to any one of claims 1 to 4, wherein the viscosity index agent comprises 50 to 60% of ethylene propylene copolymer and 40 to 50% of polymethacrylate in percentage by mass of the viscosity index agent.

6. The low friction diesel engine oil of claim 5, characterized in that the ethylene propylene copolymer has a molar content of ethylene of 45% to 55%.

7. The low friction diesel engine oil according to any one of claims 1 to 4, wherein the compounding agent comprises 18 to 25% of alkyl salicylate, 10 to 15% of sulfonate, 25 to 35% of boronated polyisobutylene succinimide, 15 to 25% of zinc dialkyl dithiophosphate, 8 to 13% of 2, 6-di-tert-butyl-p-cresol, 3 to 6% of tolyltriazole and 1 to 3% of dimethicone, in percentage by mass of the compounding agent.

8. The low friction diesel engine oil according to any one of claims 1 to 4, wherein the pour point depressant is at least one of poly-alpha olefin and polymethacrylate.

9. A method for preparing a low friction diesel engine oil according to any one of claims 1 to 8, comprising the steps of:

mixing the friction modifier with the compound.

10. The method for preparing a low-friction diesel engine oil according to claim 9, wherein the mixing temperature is controlled to be 60 ℃ to 70 ℃ when the base oil, the viscosity index agent, the complexing agent and the pour point depressant are mixed; and when the friction modifier is mixed with the mixture, controlling the mixing temperature to be 75-80 ℃.