Low-ash-content high-base-number environment-friendly diesel engine oil antioxidant composition and application thereof

Abstract

The invention relates to the technical field of diesel engine oil additives, in particular to a low-ash-content high-base-number environment-friendly diesel engine oil additive composition and application thereof. The invention provides an additive composition of diesel engine oil. The additive composition comprises dialkyl diphenylamine, a phenolic ester compound and a thiophenol compound in a mass ratio of (2-8): 1: 1, the structural formula of the dialkyl diphenylamine is # imgabs0 #, wherein R1 and R2 are the same or different alkyl groups of C1-C8; the molecular weight of the phenolic ester compound is 200 to 400. The antioxidant composition is optimized, so that the oxidation resistance is remarkably improved, more importantly, the initial total base number of an oil product can be remarkably increased under the condition that the ash content of the oil product is not increased, and the service life of the oil product is remarkably prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of diesel engine oil additives, and in particular to an environmentally friendly diesel engine oil antioxidant composition with low ash content and high alkalinity value and application thereof. Background Art

[0002] In recent years, in order to solve the increasingly prominent air pollution problem, vehicle pollutant emission standards have been upgraded many times, especially for particulate matter and nitrogen oxide emissions, and diesel engine post-treatment technology has continued to develop. At present, with the innovation of engine technology and the gradual implementation of the National VI emission regulations, various OEM manufacturers have upgraded their filling oil and after-sales oil, requiring the use of diesel engine oil with low ash content and long oil change period.

[0003] At present, the engine oil of National VI commercial vehicles requires the use of API CJ-4 / CK-4 / FA-4 or ACEA E6 / E8 / E9 / E11 diesel engine oil with an ash content of no more than 1.0% (mass fraction) to protect the vehicle's aftertreatment device. The main source of ash is the detergent component that provides the alkalinity in the engine oil. The ash limit and the increase in alkalinity restrict each other. Therefore, how to effectively improve the initial alkalinity and antioxidant properties of the product while meeting the low ash limit requirements for environmentally friendly oil products, thereby enhancing the durability of the oil products and bringing longer oil change cycles to commercial vehicles has become a problem that needs to be solved urgently.

[0004] In the prior art, CN 102690714 A discloses a railway medium- and high-speed diesel engine lubricating oil composition, but it only optimizes the anti-oxidation performance of the lubricating oil in a targeted manner, and does not involve the conflicting problem between the ash content and the alkalinity value that restrict each other. It can be seen that there is still room for further improvement in current lubricating oil products. Summary of the invention

[0005] Diesel engines are mostly used under high-load and high-temperature conditions. As the engine oil oxidizes, it will continuously produce acidic substances. The initial alkalinity provided by the oil neutralizes these acidic substances and reduces the risk of acid corrosion in the engine. After the alkalinity drops to a certain level, the oil reaches the recommended oil change cycle and needs to be replaced. The alkalinity of diesel engine oil in the prior art is mainly provided by functional additives containing organic salts such as calcium, magnesium, zinc, molybdenum, and boron; although excessive addition of the above functional additives can increase the alkalinity of the product, it will also bring about excessive sulfate ash content, which may clog the vehicle's post-processing device and have an adverse impact on the environment through vehicle emissions, making it difficult for diesel engine oil to meet high standards of environmental quality requirements.

[0006] The present invention unexpectedly discovered through extensive research and practice that a specific phenolic ester antioxidant compounded with thiophenolic and amine antioxidants can effectively contribute to the base number and improve the antioxidant properties of oil products without producing sulfate ash.

[0007] Specifically, the technical solution of the present invention is as follows:

[0008] The present invention provides an additive composition for diesel engine oil, comprising dialkyl diphenylamine, phenolic ester compounds and thiophenolic compounds in a mass ratio of (2-8):1:1; the structural formula of the dialkyl diphenylamine is Wherein, R1 and R2 are the same or different C1-C8 alkyl groups;

[0009] The molecular weight of the phenol ester compound is 200-400.

[0010] The present invention finds that the phenolic ester compounds with the above molecular weight are compounded with thiophenol-type and amine-type antioxidants and applied to diesel engine oil, which can significantly increase the base number without increasing the ash content of the oil, while improving the antioxidant performance of the oil, thereby solving the problem of the incompatibility between the demand for increasing the life of the lubricating oil and environmental protection.

[0011] In the present invention, the phenolic ester compound is a liquid polymer phenolic ester antioxidant; preferably, when the phenolic ester compound is 3,5-di-tert-butyl-4-hydroxyphenylpropionate and / or 2,6-di-tert-butyl-4-hydroxyphenylpropionate, the effect is better.

[0012] In the present invention, those skilled in the art can apply different phenolic ester antioxidants to the additive composition as needed, including but not limited to the following product models: T512 (Beijing Xingpu Fine Chemical Technology Development Co., Ltd.), RF1135 (Xinxiang Ruifeng New Materials Co., Ltd.), etc.

[0013] Preferably, the molecular weight of the thiophenol compound is 500-1000.

[0014] Preferably, the thiophenol compound is diethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], and its structural formula is

[0015] In the present invention, those skilled in the art can apply different thiophenol-type antioxidants to the additive composition as needed, including but not limited to the following product models: T535 (Beijing Xingpu Fine Chemical Technology Development Co., Ltd.), RF1035 (Xinxiang Ruifeng New Materials Co., Ltd.), Irganox 1035 (BASF), etc.

[0016] Preferably, the molecular weight of the dialkyl diphenylamine is 300 to 500, and / or the base value of the dialkyl diphenylamine is 150 to 200 mgKOH / g.

[0017] Preferably, the dialkyl diphenylamine is butyl octyl diphenylamine.

[0018] In the present invention, those skilled in the art can apply different butyl octyl diphenylamine antioxidants to the additive composition as needed, including but not limited to the following product models: T534 (Beijing Xingpu Fine Chemical Technology Development Co., Ltd.), RF5057 (Xinxiang Ruifeng New Materials Co., Ltd.), L57 (BASF), etc.

[0019] The present invention also provides a diesel engine oil, which contains the antioxidant composition.

[0020] Preferably, based on the total mass of the diesel engine oil, the amount of the antioxidant composition is 0.2-2.0 wt %; more preferably, the amount of the antioxidant composition is 0.4-1.0 wt %.

[0021] Preferably, the base oil in the diesel engine oil is an HVI II group base oil.

[0022] Preferably, the kinematic viscosity of the base oil at 100°C is 4.0 to 11.0 mm 2 / s.

[0023] The present invention finds that when the antioxidant composition is compounded with the above-mentioned HVI II type base oil of kinematic viscosity, the comprehensive performance of the oil product can be further improved by synergistic enhancement.

[0024] In the present invention, the specification of the diesel engine oil meets API CJ-4, CK-4, FA-4, ACEA, E6, E8, E9 or E11.

[0025] Based on the above technical solution, the beneficial effects of the present invention are:

[0026] The present invention not only significantly improves the antioxidant performance by optimizing the antioxidant composition, but more importantly, can significantly increase the initial total base number of the oil product without increasing the ash content of the oil product, thereby significantly extending the service life of the oil product. Specific implementation method 1

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Unless otherwise specified, all raw materials used in the examples are commercially available conventional raw materials, and the technical means used are conventional means well known to those skilled in the art.

[0029] Unless otherwise specified, the following "%" are all mass percentages.

[0030] The base oil of the diesel engine oil described in the following examples and comparative examples is HVI II+6, and the kinematic viscosity at 100°C is 5.96 mm 2 / s.

[0031] Examples 1 to 3, Comparative Examples 1 to 2

[0032] The formula of the additive composition for diesel engine oil provided in the examples and comparative examples is shown in Table 1.

[0033] Table 1 Lubricating oil composition examples

[0034]

[0035]

[0036] Experimental example: Engine oil performance verification

[0037] 1. In order to further verify the performance of the diesel engine oils of the examples and comparative examples, the antioxidant performance, base number and sulfated ash content of the engine oils were verified respectively.

[0038] The physical and chemical data of each example meet the requirements of API CK-4 specification. The test results of PDSC, base value and sulfate ash during oxidation induction period are shown in Table 2.

[0039] Table 2 Laboratory formula analysis of engine oil

[0040] Element content Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 PDSC(190℃),min 132 140 144 149 120 122 Base value, mgKOH / g 9.05 9.43 9.78 10.10 8.93 8.81 Sulfated ash, % 0.91 0.90 0.91 0.91 0.90 0.91

[0041] As can be seen from Table 2, the oxidation induction period of Examples 1-4 is significantly longer than that of Comparative Examples 1-2, and the base number is also significantly increased compared with Comparative Examples 1-2, indicating that the antioxidant performance of the engine oil of Examples 1-4 is significantly improved, and the base number level is leading in the industry. In the case of increased antioxidant performance and total base number level in Examples 1-4, the sulfated ash content remains basically unchanged, indicating that the addition of the additive composition of the present invention to the oil product has no negative impact on the environmental performance of the product.

[0042] 2. In order to further verify the performance of the diesel engine oils of the examples and comparative examples, an engine bench test was used to verify the change in base value of the engine oils during use.

[0043] The physical and chemical data of the embodiments all meet the requirements of API CK-4 specifications. The total base number test results of different oil products in the bench test are shown in Table 3.

[0044] Table 3 Analysis of base value decay of lubricating oil laboratory formula

[0045]

[0046]

[0047] From the bench test performance, the total base number decay of Example 1 is significantly better than that of Comparative Examples 1-2, indicating that the oil has excellent base number retention capability. The lubricating oils of Examples 1 to 3 above have comparable base number retention capabilities to the lubricating oil of Example 4.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An antioxidant composition for diesel engine oil, characterized in that: The invention comprises dialkyl diphenylamine, phenolic ester compounds and thiophenolic compounds in a mass ratio of (2-8):1:1; the structural formula of the dialkyl diphenylamine is Wherein, R1 and R2 are the same or different C1-C8 alkyl groups; The molecular weight of the phenol ester compound is 200-400.

2. The diesel engine oil additive composition according to claim 1, characterized in that: The phenolic ester compound is 3,5-di-tert-butyl-4-hydroxyphenyl propionate and / or 2,6-di-tert-butyl-4-hydroxyphenyl propionate.

3. The antioxidant composition for diesel engine oil according to claim 1 or 2, characterized in that: The molecular weight of the thiophenol compound is 500-1000.

4. The antioxidant composition for diesel engine oil according to any one of claims 1 to 3, characterized in that The thiophenol compound is 5. The antioxidant composition for diesel engine oil according to any one of claims 1 to 4, characterized in that: The molecular weight of the dialkyl diphenylamine is 300 to 500, and / or the base value of the dialkyl diphenylamine is 150 to 200 mgKOH / g.

6. The antioxidant composition for diesel engine oil according to any one of claims 1 to 5, characterized in that: The dialkyl diphenylamine is butyl octyl diphenylamine.

7. A diesel engine oil, characterized in that: A composition comprising the antioxidant according to any one of claims 1 to 6.

8. The diesel engine oil according to claim 7, characterized in that The mass percentage of the antioxidant composition in the diesel engine oil is 0.2-2.0wt%.

9. The diesel engine oil according to claim 7 or 8, characterized in that: The base oil in the diesel engine oil is HVIII base oil.

10. The diesel engine oil according to claim 9, characterized in that The kinematic viscosity of the base oil at 100° C. is 4.0 to 11.0 mm 2 / s.

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