Diesel engine oil and preparation method thereof

Abstract

The invention provides diesel engine oil and a preparation method thereof. The diesel engine oil is prepared from base oil, a friction modifier, a viscosity index agent, a diesel engine oil complexing agent and a pour point depressant, the friction modifier comprises fatty acid amide and a supported molybdenum cerium oxide composite material; the structure of the supported molybdenum-cerium oxide composite material is as follows: polyacrylic acid is loaded on a carrier to form a polyacrylic acid supported carrier, and molybdenum-cerium composite oxide is deposited on the polyacrylic acid supported carrier. According to the diesel engine oil provided by the invention, a compound component of a supported molybdenum cerium oxide composite material and fatty acid amide is used as a friction modifier, the antifriction effect of the diesel engine oil is remarkably improved by compounding molybdenum oxide and cerium oxide, and the stability of the structure and the performance of an oil product is improved by virtue of the loading and directional adsorption of polyacrylic acid; the problems that anti-wear particles are easy to separate out and aggregate are solved, the obtained diesel engine oil is low in viscosity, and the circulating oil consumption and the long mileage stability of the diesel engine oil are remarkably reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricating oils, and in particular relates to diesel engine oil and a preparation method thereof. Background Art

[0002] With the development of the automotive industry, energy conservation and emission reduction have become the focus of global automotive technology research. This has led to new challenges in the development and improvement of diesel engine oils. Reducing mechanical losses in internal combustion engines, particularly those caused by friction, is one of the key measures to improve fuel economy and thermal efficiency.

[0003] Against this backdrop, low-viscosity diesel engine oil has garnered widespread attention as an effective solution. Low-viscosity oils can effectively reduce friction and wear between friction pairs, thereby reducing fuel consumption and improving engine efficiency. However, due to the high loads of commercial vehicles, the use of low-viscosity diesel engine oils may pose certain technical risks. The actual operating environment of different engine components, such as shear rate, temperature, and load, is complex and variable. This results in different lubrication conditions, primarily including fluid lubrication, boundary lubrication, and mixed lubrication. Each lubrication condition has different requirements, leading to different lubricant performance requirements. In particular, under boundary lubrication and mixed lubrication conditions, direct contact between engine components increases, making wear more severe. To address the wear protection issues associated with low-viscosity oils, it is necessary to optimize the lubricant's friction properties to effectively reduce fuel consumption, improve engine wear resistance, and mitigate the wear risks associated with low-viscosity oils.

[0004] CN115011402A discloses a low-viscosity, energy-saving diesel engine oil based on a cerium oxide nano-additive and its preparation method. The oil comprises the cerium oxide nano-additive, base oil, monoalkenyl succinimide, dialkenyl succinimide, low-base synthetic calcium sulfonate, overbased synthetic magnesium sulfonate, dioctyl basic zinc salt of thiophosphate, N-phenyl-α-naphthylamine, ethylene glycol oleate, an anti-foaming agent, and a viscosity modifier. The addition of the cerium oxide nano-additive improves the friction performance of the lubricating oil and increases energy efficiency.

[0005] CN116904251A discloses a diesel engine oil and its preparation method, comprising a base oil, a viscosity index modifier, a friction modifier, a functional additive, and a pour point depressant. The friction modifier comprises an organic ammonium salt and hexagonal boron nitride-supported cerium oxide. The friction modifier is compounded to improve the friction performance of the diesel engine oil.

[0006] CN115074175A discloses a low-friction diesel engine oil and its preparation method. The oil comprises a base oil, a viscosity index enhancer, a friction modifier, a compounding agent, and a pour point depressant. The friction modifier comprises organic molybdenum, an organic ester, and nanoparticles. The molybdenum forms a tribofilm, thereby improving the friction and wear performance of the lubricating oil.

[0007] Existing technologies use molybdenum salts or rare earth oxides as friction modifiers to form a protective film and improve the friction performance of diesel engine oil. However, rare earth oxides or molybdenum compounds often suffer from decreased stability at high temperatures and poor particle dispersion, which can lead to particle precipitation and affect oil stability.

[0008] Based on this, it is necessary to develop lubricants with low viscosity and better friction performance to improve the fuel economy and environmental friendliness of diesel engines. Summary of the Invention

[0009] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a diesel engine oil and a preparation method thereof, which can effectively reduce engine friction loss and reduce fuel consumption by optimizing friction modifiers and diesel engine oil components.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides a diesel engine oil, comprising:

[0012] Base oil, friction modifier, viscosity index agent, diesel engine oil additive package and pour point depressant;

[0013] The friction modifier includes a fatty acid amide and a supported molybdenum-cerium oxide composite material;

[0014] The structure of the supported molybdenum-cerium oxide composite material comprises: a carrier loaded with polyacrylic acid to form a polyacrylic acid-loaded carrier, and the molybdenum-cerium composite oxide is deposited on the polyacrylic acid-loaded carrier.

[0015] The diesel engine oil provided by the present invention uses a fatty acid amide and a supported molybdenum-cerium oxide composite material as a friction modifier. Polyacrylic acid is adsorbed on a carrier, and the polyacrylic acid can produce a good directional adsorption effect on molybdenum oxide and cerium oxide to form dispersed anti-wear particles. The composite structure has good stability and dispersibility, overcoming the problems of easy agglomeration and precipitation of the anti-wear particles. Molybdenum oxide and cerium oxide cooperate to form a lubricating film on the friction surface. Fatty acid amide serves as an organic friction reducer, which can further improve the dispersibility of the supported molybdenum-cerium oxide composite material in the diesel engine oil, and at the same time exerts a good friction-reducing synergistic effect with the supported molybdenum-cerium oxide composite material, thereby significantly reducing the friction effect and improving the stability of the oil product.

[0016] Preferably, in the supported molybdenum-cerium oxide composite material, the loading amount of polyacrylic acid is 0.01-15wt%, for example, it can be 0.01wt%, 0.05wt%, 0.1wt%, 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt% or 15wt%, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, preferably 1-10wt%, more preferably 4-6wt%.

[0017] Preferably, in the supported molybdenum-cerium oxide composite material, the content of the molybdenum-cerium composite oxide is 0.1-50wt%, for example, it can be 0.1wt%, 0.5wt%, 1wt%, 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt% or 50wt%, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, preferably 10-30wt%, and more preferably 18-22wt%.

[0018] Preferably, in the supported molybdenum-cerium oxide composite material, the molar ratio of molybdenum to cerium is (0.01-100):1, for example, it can be 0.01:1, 0.05:1, 0.1:1, 0.5:1, 1:1, 5:1, 10:1, 20:1, 30:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1 or 100:1, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably (1-10):1, more preferably (3-5):1.

[0019] Preferably, the molecular weight of the polyacrylic acid is in the range of 1000-4000.

[0020] Preferably, the support comprises silica.

[0021] Preferably, the particle size of the silicon dioxide is in the range of 0.3-0.45 mm, for example, 0.3 mm, 0.35 mm, 0.4 mm or 0.45 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0022] Preferably, the specific surface area of ​​the silicon dioxide is 100-300m 2 / g, for example, it can be 100m 2 / g, 150m 2 / g, 200m 2 / g, 250m 2 / g or 300m 2 / g, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0023] Preferably, the silica is calcined before use.

[0024] Preferably, the preparation method of the supported molybdenum-cerium oxide composite material comprises: mixing a carrier with a polyacrylic acid solution and impregnating the mixture to obtain a polyacrylic acid supported carrier; and mixing the polyacrylic acid supported carrier with a molybdenum source and a cerium source and calcining the mixture to obtain the supported molybdenum-cerium oxide composite material.

[0025] Preferably, the pH of the polyacrylic acid solution is 4-7, for example, 4, 4.5, 5, 5.5, 6, 6.5 or 7, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0026] Preferably, the molybdenum source comprises molybdate.

[0027] Preferably, the molybdate comprises (NH4)2MoO4.

[0028] Preferably, the cerium source comprises a cerium salt.

[0029] Preferably, the cerium salt comprises Ce(NO3)3·6H2O.

[0030] Preferably, the calcination temperature is 300-350°C, for example, 300°C, 310°C, 320°C, 330°C, 340°C or 350°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0031] Preferably, the calcination time is 2-4 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0032] Preferably, the fatty acid amide comprises oleamide.

[0033] Preferably, the friction modifier comprises, by mass percentage, 0.1-35% of the supported molybdenum-cerium oxide composite material and 65-99.99% of the fatty acid amide.

[0034] In the friction modifier, the content of the supported molybdenum-cerium oxide composite material is 0.1-35%, for example, it can be 0.1%, 1%, 5%, 10%, 15%, 20%, 25%, 30% or 35%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0035] In the friction modifier, the content of fatty acid amide is 65-99.99%, for example, it can be 65%, 70%, 75%, 80%, 85%, 90%, 95% or 99.99%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0036] Preferably, the composition of the diesel engine oil includes, by mass percentage, 65-90% base oil, 0.01-12% friction modifier, 1-15% viscosity index agent, 2-20% diesel engine oil compound, and 0.01-1% pour point depressant.

[0037] The base oil content in the diesel engine oil is 65-90%, for example, 65%, 70%, 75%, 80%, 85% or 90%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0038] The content of the friction modifier in the diesel engine oil is 0.01-12%, for example, it can be 0.01%, 0.1%, 1%, 3%, 5%, 8%, 10% or 12%, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0039] The content of the viscosity index agent in the diesel engine oil is 1-15%, for example, 1%, 3%, 5%, 8%, 10%, 12% or 15%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0040] In the diesel engine oil, the content of the diesel engine oil compound is 2-20%, for example, it can be 2%, 5%, 8%, 10%, 12%, 15%, 18% or 20%, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0041] The content of the pour point depressant in the diesel engine oil is 0.01-1%, for example, 0.01%, 0.05%, 0.1%, 0.3%, 0.5%, 0.8% or 1%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0042] Preferably, the base oil comprises Group III base oil, synthetic base oil and sebacate.

[0043] Preferably, the Group III base oil includes YUBASE 4 and / or YUBASE 6.

[0044] Preferably, the synthetic base oil comprises a polyalkylene glycol.

[0045] Preferably, the base oil comprises: YUBASE4, YUBASE6, polyalkylene glycol and sebacic acid ester, and the mass ratio of YUBASE4, YUBASE6, polyalkylene glycol and sebacic acid ester is (4-6):(1-3):(0.5-1.5):1, for example, it can be 5:2:1:1, 4:2:1:1, 6:2:1:1, 5:1:1:1, 5:3:1:1, 5:2:0.5:1 or 5:2:1.5:1, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0046] In the present invention, by compounding the base oil of the components, the anti-oxidation performance and low-temperature performance of the oil product are improved, and the compatibility of various components such as the friction modifier is improved, thereby improving the stability of the oil product.

[0047] Preferably, the Noack evaporation loss of the base oil is ≤10%, for example, it can be 10%, 9%, 8%, 6%, 5% or 3%, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, wherein the Noack evaporation loss is calculated as mass fraction.

[0048] Preferably, the low-temperature dynamic viscosity of the base oil is ≤2200 mPa·s, for example, it can be 2200 mPa·s, 2000 mPa·s, 1800 mPa·s, 1500 mPa·s or 1000 mPa·s, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0049] The temperature of the "low temperature" is -25°C.

[0050] Preferably, the pour point of the base oil is ≤-45°C, for example, it can be -45°C, -48°C, -50°C, -55°C or -60°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0051] Preferably, the viscosity index of the base oil is greater than 125, for example, it may be 126, 128, 130, 135, 140 or 150, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0052] Preferably, the viscosity index agent comprises, by weight percentage, 55-80% of multi-arm spherical hydrogenated polystyrene diene polymer and 20-45% of semi-crystalline ethylene propylene copolymer.

[0053] In the viscosity index agent, the content of the multi-arm spherical hydrogenated polystyrene diene polymer is 55-80%, for example, it can be 55%, 60%, 65%, 70%, 75% or 80%, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0054] In the viscosity index agent, the content of the semi-crystalline ethylene propylene copolymer is 20-45%, for example, 20%, 25%, 30%, 35%, 40% or 45%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0055] Preferably, the diesel engine oil additive package includes at least one of a metal detergent, an ashless dispersant, an extreme pressure anti-wear agent, an antioxidant, a defoaming agent or a metal deactivator.

[0056] Preferably, the metal detergent comprises overbased sulfurized calcium alkylphenate and / or overbased magnesium alkyl salicylate.

[0057] Preferably, the ashless dispersant comprises boronated polyisobutylene succinimide.

[0058] Preferably, the extreme pressure antiwear agent comprises antimony dialkyldithiocarbamate.

[0059] Preferably, the antioxidant comprises 2,6-di-tert-butyl mixed phenol.

[0060] Preferably, the metal deactivator comprises methylbenztriazole ester and / or 2,5-dimercapto-1,3,4-thiadiazole derivative.

[0061] Preferably, the defoaming agent comprises methyl silicone oil.

[0062] Preferably, the composition of the diesel engine oil compound includes, by mass percentage: 10-14% of overbased sulfurized alkyl phenate calcium, 10-14% of overbased alkyl magnesium salicylate, 14-16% of phosphoboronated polyisobutylene succinimide, 24-28% of antimony dialkyl dithiocarbamate, 16-20% of methylbenzenetriazole ester, 14-16% of 2,6-di-tert-butyl mixed phenol, 0.5-2% of 2,5-dimercapto-1,3,4-thiadiazole derivative, and 0.5-2% of methyl silicone oil.

[0063] In the present invention, the “high base number” refers to a total base number (TBN) of the additive greater than 250 mgKOH / g.

[0064] In the diesel engine oil, the content of high base value sulfurized alkyl phenate calcium is 10-14%, for example, it can be 10%, 11%, 12%, 13% or 14%, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0065] In the diesel engine oil, the content of overbased magnesium alkyl salicylate is 10-14%, for example, 10%, 11%, 12%, 13% or 14%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0066] In the diesel engine oil, the content of boronated polyisobutylene succinimide is 14-16%, for example, 14%, 14.5%, 15%, 15.5% or 16%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0067] The content of antimony dialkyl dithiocarbamate in the diesel engine oil is 24-28%, for example, 24%, 25%, 26%, 27% or 28%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0068] The content of methylbenzyltriazole in the diesel engine oil is 16-20%, for example, 16%, 17%, 18%, 19% or 20%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0069] The content of 2,6-di-tert-butyl mixed phenol in the diesel engine oil is 14-16%, for example, 14%, 14.5%, 15%, 15.5% or 16%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0070] In the diesel engine oil, the content of 2,5-dimercapto-1,3,4-thiadiazole derivative is 0.5-2%, for example, 0.5%, 1%, 1.5% or 2%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0071] The content of methyl silicone oil in the diesel engine oil is 0.5-2%, for example, 0.5%, 1%, 1.5% or 2%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0072] Preferably, the pour point depressant comprises vinyl acetate-fumarate copolymer.

[0073] Preferably, the viscosity grade of the diesel engine oil is 0W-20.

[0074] Preferably, the high temperature and high shear viscosity of the diesel engine oil is in the range of 2.6-2.9 mPa·s, for example, it can be 2.6 mPa·s, 2.7 mPa·s, 2.8 mPa·s or 2.9 mPa·s, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0075] In the present invention, the working conditions of "high temperature and high shear viscosity" are: temperature is 150℃, shear rate is 10 6 s -1 .

[0076] Preferably, the base number of the diesel engine oil is ≥11 mgKOH / g, for example, it can be 11 mgKOH / g, 12 mgKOH / g, 15 mgKOH / g, 18 mgKOH / g, 20 mgKOH / g, 25 mgKOH / g or 30 mgKOH / g, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0077] Preferably, the oil change mileage of the diesel engine oil is 100,000-300,000 kilometers, for example, it can be 100,000 kilometers, 150,000 kilometers, 200,000 kilometers, 250,000 kilometers or 300,000 kilometers, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0078] In a second aspect, the present invention provides a method for preparing the diesel engine oil according to the second aspect, the preparation method comprising the following steps:

[0079] The base oil components are mixed to obtain base oil, the base oil is mixed with a diesel engine oil compounding agent, a viscosity index agent and a pour point depressant to obtain a mixture, the mixture is mixed with a friction modifier, and allowed to stand to obtain the diesel engine oil.

[0080] Preferably, the mixing temperature of the base oil is 60-65°C, for example, 60°C, 61°C, 62°C, 63°C, 64°C or 65°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0081] Preferably, the mixing temperature of the mixture is 60-65°C, for example, 60°C, 61°C, 62°C, 63°C, 64°C or 65°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0082] Preferably, the mixing temperature of the mixture and the friction modifier is 75-80°C, for example, 75°C, 76°C, 77°C, 78°C, 79°C or 80°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0083] Compared with the prior art, the present invention has the following beneficial effects:

[0084] The diesel engine oil provided by the present invention uses a composite material of supported molybdenum-cerium oxide and a fatty acid amide as a friction modifier. The friction reduction effect of the diesel engine oil is significantly improved by compounding molybdenum oxide and cerium oxide, and the stability of the structure and oil performance is improved by the loading and directional adsorption of polyacrylic acid. In addition, the problem of easy precipitation and aggregation of anti-wear particles is overcome by combining with the oil component design. The obtained diesel engine oil has low viscosity and significantly reduces the cyclic fuel consumption and long-mileage stability of the diesel engine oil. DETAILED DESCRIPTION

[0085] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0086] In order to clearly illustrate the technical solution of the present invention, in a specific embodiment, the parameters of the raw materials used are as follows:

[0087] Polyacrylic acid: CAS number is 9007-20-9, average molecular weight is 2000.

[0088] Dioctyl sebacate: CAS number is 2432-87-3.

[0089] Polyalkylene glycol: the brand is Polyglykol B11 / 100.

[0090] Oleamide: CAS number is 301-02-0.

[0091] Multi-arm spherical hydrogenated polystyrene diene polymer: brand name is Styrene FV260.

[0092] Semi-crystalline ethylene propylene copolymer: brand name viscosity index improver P8900E.

[0093] High base value sulfurized calcium alkyl phenate: brand is sulfurized calcium alkyl phenate T115B.

[0094] High base magnesium alkyl salicylate: brand name is magnesium alkyl salicylate RHY109M.

[0095] Phosphorus-boronated polyisobutylene succinimide: the brand is polyisobutylene succinimide T161.

[0096] Antimony dialkyl dithiocarbamate: brand name extreme pressure antiwear agent T352.

[0097] Methyltriazole: The brand name is Methyltriazole T551.

[0098] 2,6-di-tert-butyl mixed phenol: brand name antioxidant T502A.

[0099] 2,5-dimercapto-1,3,4-thiadiazole derivative: the brand is metal deactivator T561.

[0100] Dimethyl silicone oil: CAS is 63148-62-9.

[0101] Vinyl acetate-fumarate copolymer: brand name pour point depressant T818.

[0102] Preparation Example 1

[0103] This preparation example provides a supported molybdenum-cerium oxide composite material.

[0104] The structure of the supported molybdenum-cerium oxide composite material comprises: a carrier loaded with polyacrylic acid to form a polyacrylic acid-loaded carrier, and the molybdenum-cerium composite oxide is deposited on the polyacrylic acid-loaded carrier.

[0105] In the supported molybdenum-cerium oxide composite material, the content of the molybdenum-cerium composite oxide is 20 wt %, the molar ratio of molybdenum to cerium is 4:1, and the loading amount of polyacrylic acid is 5 wt %.

[0106] The preparation method of the supported molybdenum-cerium oxide composite material is as follows:

[0107] (1) SiO2 was crushed, ground, and sieved to obtain particles with a particle size of 40-60 mesh (0.3-0.45 mm), which were then calcined in a muffle furnace at 500°C for 3 h to stabilize the structure of the support and remove impurities adsorbed on the surface of the support;

[0108] (2) 100 mL of a 10 mmol / L PAA (polyacrylic acid) solution was prepared, and the pH was adjusted to 5 with 0.1 mol / L sodium hydroxide and dilute hydrochloric acid solution, respectively. The SiO2 obtained in step (1) was added, and the mixture was stirred at room temperature for 12 h for impregnation, and then filtered and dried at 110°C for 12 h to obtain polyacrylic acid-loaded silica, which was recorded as SiO2@PAA.

[0109] (3) Weigh 3 g of polyacrylic acid-loaded silica, add (NH4)2MoO4 and Ce(NO3)3·6H2O, dissolve in 100 mL of distilled water, heat in a water bath, and rapidly stir and evaporate to dryness to obtain a precursor;

[0110] (4) The precursor was calcined at 320° C. for 3 h, ground, and dried at 110° C. to obtain the supported molybdenum-cerium oxide composite material, which was designated as MoO 3 -CeO 2 / SiO 2 @PAA.

[0111] Example 1

[0112] This embodiment provides a diesel engine oil, the composition of the diesel engine oil, calculated by mass percentage, includes:

[0113] Base oil 66.5%, friction modifier 9%, viscosity index agent 12%, diesel engine oil compound 12%, pour point depressant 0.5%.

[0114] The base oil consists of YUBASE4, YUBASE6, dioctyl sebacate and polyalkylene glycol, and the mass ratio of the four is 5:2:1:1.

[0115] The base oil has a Noack evaporation loss (mass fraction) of 9%, a low-temperature dynamic viscosity (-25° C.) of 2080 mPa·s, a pour point of -48° C., and a viscosity index of 135.

[0116] The friction modifier comprises, by weight percentage, 35% of a supported molybdenum-cerium oxide composite material and 65% of oleamide.

[0117] The supported molybdenum-cerium oxide composite material is the supported molybdenum-cerium oxide composite material prepared in Preparation Example 1.

[0118] The viscosity index agent comprises, by weight percentage, 75% of multi-arm spherical hydrogenated polystyrene diene polymer and 25% of semi-crystalline ethylene propylene copolymer.

[0119] The diesel engine oil compound comprises, by weight percentage, 12% of overbased sulfurized alkyl phenate calcium, 12% of overbased alkyl magnesium salicylate, 15% of phosphoborated polyisobutylene succinimide, 26% of antimony dialkyl dithiocarbamate, 18% of methylbenzenetriazole ester, 15% of 2,6-di-tert-butyl mixed phenol, 1% of 2,5-dimercapto-1,3,4-thiadiazole derivative, and 1% of dimethyl silicone oil.

[0120] The pour point depressant is vinyl acetate-fumarate copolymer.

[0121] The preparation method of the diesel engine oil comprises the following steps:

[0122] (1) Add the components of the base oil in proportion to a blending kettle and stir for 2 hours at a stirring temperature of 62° C. to obtain the base oil;

[0123] (2) Add diesel engine oil compound, viscosity index agent and pour point depressant to the blending kettle and stir for 4 hours at a stirring temperature of 62°C;

[0124] (3) Add friction modifier to the blending kettle, stir for 6 hours at a stirring temperature of 78° C., let it stand for 2 hours, and then filter to obtain the diesel engine oil.

[0125] Example 2

[0126] This embodiment provides a diesel engine oil, the composition of the diesel engine oil, calculated by mass percentage, includes:

[0127] Base oil 69.5%, friction modifier 6%, viscosity index agent 11%, diesel engine oil compound 13%, pour point depressant 0.5%.

[0128] The base oil consists of YUBASE4, YUBASE6, dioctyl sebacate and polyalkylene glycol, and the mass ratio of the four is 5:2:1:1.

[0129] The base oil has a Noack evaporation loss (mass fraction) of 9%, a low-temperature dynamic viscosity (-25° C.) of 2080 mPa·s, a pour point of -48° C., and a viscosity index of 135.

[0130] The friction modifier comprises, by weight percentage, 30% of a supported molybdenum-cerium oxide composite material and 70% of oleamide.

[0131] The supported molybdenum-cerium oxide composite material is the supported molybdenum-cerium oxide composite material prepared in Preparation Example 1.

[0132] The viscosity index agent comprises, by weight percentage, 70% of multi-arm spherical hydrogenated polystyrene diene polymer and 30% of semi-crystalline ethylene propylene copolymer.

[0133] The diesel engine oil compound comprises, by weight percentage, 12% of overbased sulfurized alkyl phenate calcium, 12% of overbased alkyl magnesium salicylate, 15% of phosphoborated polyisobutylene succinimide, 26% of antimony dialkyl dithiocarbamate, 18% of methylbenzenetriazole ester, 15% of 2,6-di-tert-butyl mixed phenol, 1% of 2,5-dimercapto-1,3,4-thiadiazole derivative, and 1% of dimethyl silicone oil.

[0134] The pour point depressant is vinyl acetate-fumarate copolymer.

[0135] The preparation method of the diesel engine oil is the same as that in Example 1.

[0136] Example 3

[0137] This embodiment provides a diesel engine oil, the composition of the diesel engine oil, calculated by mass percentage, includes:

[0138] Base oil 72.5%, friction modifier 3%, viscosity index agent 9%, diesel engine oil compound 15%, pour point depressant 0.5%.

[0139] The base oil consists of YUBASE4, YUBASE6, dioctyl sebacate and polyalkylene glycol, and the mass ratio of the four is 5:2:1:1.

[0140] The base oil has a Noack evaporation loss (mass fraction) of 9%, a low-temperature dynamic viscosity (-25° C.) of 2080 mPa·s, a pour point of -48° C., and a viscosity index of 135.

[0141] The friction modifier comprises, by weight percentage, 20% of a supported molybdenum-cerium oxide composite material and 80% of oleamide.

[0142] The supported molybdenum-cerium oxide composite material is the supported molybdenum-cerium oxide composite material prepared in Preparation Example 1.

[0143] The viscosity index agent comprises, by weight percentage, 65% of multi-arm spherical hydrogenated polystyrene diene polymer and 35% of semi-crystalline ethylene propylene copolymer.

[0144] The diesel engine oil compound comprises, by weight percentage, 12% of overbased sulfurized alkyl phenate calcium, 12% of overbased alkyl magnesium salicylate, 15% of phosphoborated polyisobutylene succinimide, 26% of antimony dialkyl dithiocarbamate, 18% of methylbenzenetriazole ester, 15% of 2,6-di-tert-butyl mixed phenol, 1% of 2,5-dimercapto-1,3,4-thiadiazole derivative, and 1% of dimethyl silicone oil.

[0145] The pour point depressant is vinyl acetate-fumarate copolymer.

[0146] The preparation method of the diesel engine oil is the same as that in Example 1.

[0147] Example 4

[0148] This embodiment provides a diesel engine oil. Compared with Example 1, the composition of the diesel engine oil, calculated by mass percentage, includes: 79.5% base oil, 12% friction modifier, 4% viscosity index agent, 4% diesel engine oil compound, and 0.5% pour point depressant. The rest is the same as in Example 1.

[0149] Example 5

[0150] This embodiment provides a diesel engine oil. Compared with Example 1, the composition of the friction modifier is set to: in terms of mass percentage, it includes: 45% of a supported molybdenum-cerium oxide composite material and 55% of oleamide. The rest is the same as Example 1.

[0151] Example 6

[0152] This embodiment provides a diesel engine oil. Compared with Example 1, dioctyl sebacate is not added to the base oil, and the rest is the same as Example 1.

[0153] Example 7

[0154] This embodiment provides a diesel engine oil. Compared with Example 1, no polyalkylene glycol is added to the base oil, and the rest is the same as Example 1.

[0155] Comparative Example 1

[0156] This comparative example provides a diesel engine oil, which is a commercially available 0W-20 grade diesel engine oil.

[0157] Comparative Example 2

[0158] This comparative example provides a diesel engine oil. Compared with Example 1, the friction modifier is composed of only oleamide, that is, the weight of the supported molybdenum-cerium oxide composite material is replaced by oleamide, and the rest is the same as Example 1.

[0159] Comparative Example 3

[0160] This comparative example provides a diesel engine oil. Compared with Example 1, the friction modifier is composed only of a supported molybdenum-cerium oxide composite material, that is, oleic acid amide and the like are replaced by the supported molybdenum-cerium oxide composite material, and the rest are the same as Example 1.

[0161] Comparative Example 4

[0162] This comparative example provides a diesel engine oil. Compared with Example 1, in the friction modifier, the supported molybdenum-cerium oxide composite material is replaced by a silicon oxide-molybdenum-cerium oxide composite material. The rest is the same as Example 1.

[0163] The preparation method of the silicon oxide-molybdenum cerium oxide composite material comprises the following steps:

[0164] (1) SiO2 was crushed, ground, and sieved to obtain particles with a particle size of 40-60 mesh (0.3-0.45 mm), which were then calcined in a muffle furnace at 500°C for 3 h to stabilize the structure of the support and remove impurities adsorbed on the surface of the support;

[0165] (2) Weigh 3 g of silica, add (NH4)2MoO4 and Ce(NO3)3·6H2O, dissolve in 100 mL of distilled water, heat in a water bath, and evaporate to dryness with rapid stirring to obtain a precursor;

[0166] (4) calcining the precursor at 320° C. for 3 h, grinding it, and drying it at 110° C. to obtain the silicon oxide-molybdenum cerium oxide composite material.

[0167] Comparative Example 5

[0168] This comparative example provides a diesel engine oil. Compared with Example 1, in the friction modifier, the supported molybdenum-cerium oxide composite material is replaced by a supported molybdenum oxide composite material in equal mass, and the rest is the same as Example 1.

[0169] The preparation method of the supported molybdenum oxide composite material comprises the following steps:

[0170] (1) SiO2 was crushed, ground, and sieved to obtain particles with a particle size of 40-60 mesh (0.3-0.45 mm), which were then calcined in a muffle furnace at 500°C for 3 h to stabilize the structure of the support and remove impurities adsorbed on the surface of the support;

[0171] (2) 100 mL of a 10 mmol / L PAA (polyacrylic acid) solution was prepared, and the pH was adjusted to 5 with 0.1 mol / L sodium hydroxide and dilute hydrochloric acid solution, respectively. The SiO2 obtained in step (1) was added, and the mixture was stirred at room temperature for 12 h for impregnation, and then filtered and dried at 110°C for 12 h to obtain polyacrylic acid-loaded silica, which was recorded as SiO2@PAA.

[0172] (3) Weigh 3 g of polyacrylic acid-loaded silica, add (NH4)2MoO4, dissolve in 100 mL of distilled water, heat in a water bath, and rapidly stir and evaporate to dryness to obtain a precursor;

[0173] (4) calcining the precursor at 320° C. for 3 h, grinding it, and drying it at 110° C. to obtain the supported molybdenum oxide composite material.

[0174] Performance Testing

[0175] The diesel engine oils provided in the examples and comparative examples were subjected to simulation tests using a physical and chemical testing machine to demonstrate their viscosity-temperature performance, low-temperature performance, oxidation resistance, friction and wear, and energy-saving performance. The results are listed in Table 1.

[0176] The viscosity performance test method is based on the GB / T 265 standard. The friction and wear test is carried out on a US Falex four-ball friction and wear tester. The actual energy-saving performance is verified by using a Jiefang heavy-duty truck.

[0177] The low temperature of "low temperature dynamic viscosity" is -35℃; the working conditions of "high temperature high shear viscosity" are: temperature 150℃, shear rate 10 6 s -1 ; The temperature condition of the "oxidation induction period" is 210°C; the value of the vehicle fuel consumption reduction rate is based on the diesel engine oil of Comparative Example 1.

[0178] Table 1

[0179]

[0180]

[0181] “ / ” in the table indicates no data.

[0182] As can be seen from Table 1:

[0183] (1) The diesel engine oil provided by the present invention uses a loaded molybdenum-cerium oxide composite material and a fatty acid amide as a friction modifier, and is compounded with base oil, viscosity index agent, compounding agent and other components. Through the design of diesel engine oil components, the performance of diesel engine oil is effectively improved. While maintaining low viscosity performance, the friction performance and effect are effectively improved. The obtained diesel engine oil has good viscosity performance, viscosity index ≥150, low-temperature dynamic viscosity ≤6196mPa·s, high-temperature high-shear viscosity ≥2.6mPa·s; has good thermal oxidation aging stability; produces a good friction reduction effect, the four-ball average friction coefficient is maintained below 0.152, and the four-ball wear spot diameter is less than 0.60; at the same time, it has excellent energy-saving performance, and compared with commercially available diesel engine oil products, the fuel consumption rate is reduced to more than 0.54%.

[0184] (2) Comparing the results of Examples 1-3, it is found that appropriately increasing the content of the friction modifier can significantly improve the friction reduction effect of the diesel engine oil while maintaining low viscosity. The friction coefficient and wear spot diameter both decrease, effectively reducing fuel consumption and improving energy conservation on the basis of friction reduction. Comparing the results of Example 1 with Example 4, the friction reduction effect decreases slightly when the amount of friction modifier added is further increased, and the viscosity performance increases slightly when the viscosity index agent is added in a small amount. Comparing the results of Example 1 with Example 5, the friction reduction effect also decreases slightly when the amount of the supported molybdenum-cerium oxide composite material used in the friction modifier component is too large.

[0185] (3) Compared with the results of Example 1, when the base oil components lack the compound components, the viscosity performance and friction reduction performance of the diesel engine oil are slightly reduced. At the same time, the thermal oxidation stability is also slightly reduced. This shows that when the base oil adopts the compound components, it can produce an auxiliary friction reduction effect on the friction modifier and improve the stability and durability of the oil.

[0186] (4) Compared with the results of Example 1, the diesel engine oil of the present invention has significantly improved performance compared to the commercial diesel engine oil product of Comparative Example 1; in Comparative Examples 2 and 3, when the friction modifier is only a single component, the friction reduction effect brought by the component compounding is lacking, and the anti-wear particles are very easy to aggregate and precipitate, and the friction reduction effect is significantly reduced; in Comparative Example 4, when polypropylene is not loaded, the anti-wear particles are not easy to disperse and are easy to form agglomerates and precipitate. In Comparative Example 5, only a single oxide is used, and the friction reduction reinforcement of the composite oxide is lacking, resulting in a significant decline in the friction reduction effect, and it is difficult to maintain long-term friction reduction. It can be seen that the performance of the diesel engine oil is maximized by the component compounding and synergistic enhancement of the composite material and the friction modifier.

[0187] In summary, the diesel engine oil provided by the present invention uses a loaded molybdenum-cerium oxide composite material and a fatty acid amide compound as a friction modifier, significantly improves the friction reduction effect of the diesel engine oil through the composite of molybdenum oxide and cerium oxide, and improves the stability of the structure and oil performance through the loading and directional adsorption of polyacrylic acid. In addition, the problem of easy precipitation and aggregation of anti-wear particles is overcome in conjunction with the oil component design. The resulting diesel engine oil has low viscosity, significantly reducing the cyclic fuel consumption and long-mileage stability of the diesel engine oil.

[0188] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A diesel engine oil, characterized in that: The composition of the diesel engine oil comprises: Base oil, friction modifier, viscosity index agent, diesel engine oil additive package and pour point depressant; The friction modifier includes a fatty acid amide and a supported molybdenum-cerium oxide composite material; The structure of the supported molybdenum-cerium oxide composite material comprises: a carrier loaded with polyacrylic acid to form a polyacrylic acid-loaded carrier, and the molybdenum-cerium composite oxide is deposited on the polyacrylic acid-loaded carrier.

2. The diesel engine oil according to claim 1, characterized in that In the supported molybdenum-cerium oxide composite material, the loading amount of polyacrylic acid is 0.01-15wt%; Preferably, in the supported molybdenum-cerium oxide composite material, the content of the molybdenum-cerium composite oxide is 0.1-50 wt %; Preferably, in the supported molybdenum-cerium oxide composite material, the molar ratio of molybdenum to cerium is (0.01-100):1; Preferably, the support comprises silica; Preferably, the preparation method of the supported molybdenum-cerium oxide composite material comprises: mixing a carrier with a polyacrylic acid solution and impregnating the mixture to obtain a polyacrylic acid supported carrier; mixing the polyacrylic acid supported carrier with a molybdenum source and a cerium source and calcining the mixture to obtain the supported molybdenum-cerium oxide composite material; Preferably, the pH of the polyacrylic acid solution is 4-7; Preferably, the calcination temperature is 300-350°C; Preferably, the roasting time is 2-4h; Preferably, the fatty acid amide comprises oleamide.

3. The diesel engine oil according to claim 1 or 2, characterized in that The friction modifier comprises, by weight percentage, 0.1-35% of a supported molybdenum-cerium oxide composite material and 65-99.9% of a fatty acid amide; Preferably, the composition of the diesel engine oil includes, by mass percentage, 65-90% base oil, 0.01-12% friction modifier, 1-15% viscosity index agent, 2-20% diesel engine oil compound, and 0.01-1% pour point depressant.

4. The diesel engine oil according to any one of claims 1 to 3, characterized in that The base oil includes Group III base oil, synthetic base oil and sebacate; Preferably, the Group III base oil includes YUBASE4 and / or YUBASE6; Preferably, the synthetic base oil comprises polyalkylene glycol; Preferably, the base oil comprises: YUBASE4, YUBASE6, polyalkylene glycol and sebacic acid ester, and the mass ratio of YUBASE4, YUBASE6, polyalkylene glycol and sebacic acid ester is (4-6):(1-3):(0.5-1.5):1; Preferably, the Noack evaporation loss of the base oil is ≤10%; Preferably, the low-temperature dynamic viscosity of the base oil is ≤2200 mPa·s; Preferably, the pour point of the base oil is ≤-45°C; Preferably, the viscosity index of the base oil is >125.

5. The diesel engine oil according to any one of claims 1 to 4, characterized in that The viscosity index agent comprises, by weight percentage, 55-80% of multi-arm spherical hydrogenated polystyrene diene polymer and 20-45% of semi-crystalline ethylene propylene copolymer.

6. The diesel engine oil according to any one of claims 1 to 5, characterized in that The diesel engine oil compound comprises at least one of a metal detergent, an ashless dispersant, an extreme pressure anti-wear agent, an antioxidant, a defoaming agent or a metal deactivator; Preferably, the metal detergent comprises overbased sulfurized calcium alkylphenate and / or overbased magnesium alkyl salicylate; Preferably, the ashless dispersant comprises phosphoborated polyisobutylene succinimide; Preferably, the extreme pressure antiwear agent comprises antimony dialkyldithiocarbamate; Preferably, the antioxidant comprises 2,6-di-tert-butyl mixed phenol; Preferably, the metal deactivator comprises methylbenztriazole ester and / or 2,5-dimercapto-1,3,4-thiadiazole derivative; Preferably, the defoaming agent comprises methyl silicone oil; Preferably, the composition of the diesel engine oil compound includes, by mass percentage: 10-14% of overbased sulfurized alkyl phenate calcium, 10-14% of overbased alkyl magnesium salicylate, 14-16% of phosphoboronated polyisobutylene succinimide, 24-28% of antimony dialkyl dithiocarbamate, 16-20% of methylbenzenetriazole ester, 14-16% of 2,6-di-tert-butyl mixed phenol, 0.5-2% of 2,5-dimercapto-1,3,4-thiadiazole derivative, and 0.5-2% of methyl silicone oil.

7. The diesel engine oil according to any one of claims 1 to 6, characterized in that The pour point depressant includes vinyl acetate-fumarate copolymer.

8. The diesel engine oil according to any one of claims 1 to 7, characterized in that The viscosity grade of the diesel engine oil is 0W-20; Preferably, the high temperature and high shear viscosity of the diesel engine oil is in the range of 2.6-2.9 mPa·s; Preferably, the base number of the diesel engine oil is ≥11 mgKOH / g; Preferably, the oil change mileage of the diesel engine oil is 100,000-300,000 kilometers.

9. A method for preparing diesel engine oil according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: The base oil components are mixed to obtain base oil, the base oil is mixed with a diesel engine oil compounding agent, a viscosity index agent and a pour point depressant to obtain a mixture, the mixture is mixed with a friction modifier, and allowed to stand to obtain the diesel engine oil.

10. The preparation method according to claim 9, characterized in that The mixing temperature of the base oil is 60-65°C; Preferably, the mixing temperature of the mixed material is 60-65°C; Preferably, the mixing temperature of the mixed material and the friction modifier is 75-80°C.

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