Lubricating oil composition and preparation method thereof

Abstract

The invention belongs to the technical field of lubricating oil, and particularly relates to a lubricating oil composition and a preparation method thereof. The lubricating oil composition provided by the invention is prepared from linear siloxane, organic modified polysiloxane and pentaerythritol ester. The lubricating oil composition has the beneficial effects that the linear siloxane and the organic modified polysiloxane in the lubricating oil composition have relatively low low-temperature viscosity and relatively high compatibility, and can be mutually dissolved with the pentaerythritol ester to improve the characteristic of relatively high viscosity at low temperature; the mixed lubricating system obtained through the preparation method has the characteristics of being simple in mixing mode, excellent in uniformity, large in mixing amount and the like, and is suitable for industrial production.

Description

Technical Field

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

[0002] Lubricating oil effectively lubricates bearings, transmission gears and other parts that frequently experience friction and wear, and removes the heat absorbed by the lubricated parts, thereby keeping the engine in a stable working state. Polar navigation is accompanied by harsh conditions such as low temperature and sea conditions. There are also low-temperature application scenarios in high-altitude extremely cold areas. For example, in the Arctic region in winter, the temperature is between -43 and -26°C, with an average temperature of -34°C; in high-altitude and cold areas such as Tibet and Qinghai, the temperature is above 4,000 meters above sea level and is -10°C, which puts higher requirements on the application of lubricating oil at low temperatures.

[0003] The viscosity of lubricating oil is one of the most important physical properties that affect heat and mass transfer. It is an important property that determines the thickness of the oil film on the bearing surface and the pressure and temperature conditions of elastic fluid dynamic lubrication. In addition, viscosity is also an important factor affecting the fatigue life of bearings and gears. For most lubricants, the viscosity increases at low temperatures (<-10°C), the torque required to start the machinery or equipment increases, and the fluidity deteriorates, resulting in insufficient lubrication and increased friction and wear. In order to improve the low-temperature viscosity of lubricating oil, researchers add antifreeze and additives to reduce the viscosity of lubricating oil at low temperatures, but due to the difference in lubrication performance between additives and lubricants, their wear resistance and anti-wear performance are weakened.

[0004] Pentaerythritol Ester (PAG or Ester for short) is a synthetic base oil with excellent thermal oxidation stability and low volatility at high temperatures. Its viscosity-temperature characteristics are as follows: under high temperature conditions, it can maintain a low viscosity change and provide a stable lubricating film; while the viscosity will not be too high under lower temperature conditions, ensuring liquid fluidity and good starting performance. These characteristics make pentaerythritol ester popular in many demanding industrial applications such as aviation, turbines, and high temperature environments. However, the viscosity of pentaerythritol ester (3,5,5-trimethylacetate) at 0°C is 10mPas@100s -1 , and its viscosity continues to decrease with the decrease in temperature, which greatly limits its application in low-temperature starting and movement.

[0005] Studies have found that adding polyisobutylene copolymers, ethylene-propylene copolymers, and polymethyl methacrylate copolymers to pentaerythritol ester lubricants can adjust the low-temperature viscosity of pentaerythritol ester lubricants, but affect their tribological characteristics in a wide temperature range. Therefore, finding a suitable method to solve the problem of poor rheological properties of pentaerythritol ester lubricants at low temperatures has a good application prospect. Summary of the invention

[0006] The present application provides a lubricating oil composition and a preparation method thereof, aiming to solve the problem that pentaerythritol ester lubricating oil has poor rheological properties at low temperatures.

[0007] In a first aspect, the present application provides a lubricating oil composition, comprising linear siloxane, organic modified polysiloxane and pentaerythritol ester.

[0008] The linear siloxane and the organic modified polysiloxane in the lubricating oil composition described in the present application have a relatively low low temperature viscosity and a relatively strong compatibility, and can be miscible with the pentaerythritol ester to improve the property of the high viscosity at low temperatures.

[0009] According to some embodiments of the lubricating oil composition described herein, the linear polysiloxane includes one or more of methyl silicone oil, ethyl silicone oil, dimethyl silicone oil, benzyl silicone oil and diethyl silicone oil.

[0010] According to some embodiments of the lubricating oil composition described in the present application, the linear polysiloxane is one or more of ethyl silicone oil, benzyl silicone oil and methyl silicone oil.

[0011] According to some embodiments of the lubricating oil composition described in the present application, the organic modified polysiloxane includes one or more of chlorophenylsiloxane, methyltetrachlorophenyl silicone oil, hydroxyfluorosilicone oil and fluorochlorosilicone oil.

[0012] According to some embodiments of the lubricating oil composition described in the present application, the organic modified polysiloxane is one or more of chlorophenylsiloxane, methyltetrachlorophenyl silicone oil and hydroxyfluorosilicone oil.

[0013] According to some embodiments of the lubricating oil composition described in the present application, the mass ratio of the linear siloxane, the organic modified polysiloxane and the pentaerythritol ester is (1-5):(0-3):(0-9).

[0014] According to some embodiments of the lubricating oil composition described in the present application, the mass ratio of the linear siloxane, the organic modified polysiloxane and the pentaerythritol ester is (0.6-1.5):1:(1-1.6).

[0015] According to some embodiments of the lubricating oil composition described in the present application, the viscosity of the lubricating oil composition at 0° C. is 0.15-0.55 Pa.s.

[0016] The second aspect of the present application provides a method for preparing the lubricating oil composition described in the first aspect of the present application, comprising the following steps: mixing linear siloxane, organic modified polysiloxane and pentaerythritol ester to obtain the lubricating oil composition.

[0017] The mixed lubrication system obtained by the preparation method of the present application has the characteristics of simple mixing method, excellent uniformity, large mixing amount, etc., and is suitable for industrial production.

[0018] According to some embodiments of the method for preparing the lubricating oil composition described in the present application, the mixing temperature is 50-80° C., and the mixing time is 10-60 min. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below. The embodiments described below are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0020] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0021] The present application provides a lubricating oil composition, comprising linear siloxane, organic modified polysiloxane and pentaerythritol ester. The linear siloxane and organic modified polysiloxane in the lubricating oil composition of the present application have low low temperature viscosity and strong compatibility, and can be miscible with pentaerythritol ester to improve its high viscosity at low temperature.

[0022] In some embodiments of the present application, the linear polysiloxane includes one or more of methyl silicone oil, ethyl silicone oil, dimethyl silicone oil, benzyl silicone oil and diethyl silicone oil.

[0023] In some embodiments of the present application, the linear polysiloxane is one or more of ethyl silicone oil, benzyl silicone oil and methyl silicone oil. Ethyl silicone oil has weak intermolecular forces due to the effect of the ethyl group, has the characteristics of being miscible with ester oil and mineral oil, and has excellent thermal stability, good dielectric properties, hydrophobicity and low surface tension, so it is used as a base oil for materials such as polishing agents and magnetorheological agents.

[0024] In some embodiments of the present application, the organic modified polysiloxane includes one or more of chlorophenylsiloxane, methyltetrachlorophenyl silicone oil, hydroxyfluorosilicone oil and fluorochlorosilicone oil.

[0025] In some embodiments of the present application, the organic modified polysiloxane is one or more of chlorophenyl siloxane, methyl tetrachlorophenyl silicone oil and hydroxy fluorosilicone oil. Chlorophenyl siloxane is obtained by introducing polychlorobenzyl groups into the chemical structure of polysiloxane, and its physical properties are colorless or light yellow transparent liquids, and the physical properties vary with the molecular weight. With the increase of phenyl content, the density and refractive index increase, the freezing point of low phenyl content is lower than -70 ° C, the thermal stability of medium and high phenyl content is improved, and it has excellent radiation resistance.

[0026] In some embodiments of the present application, the mass ratio of the linear siloxane, the organic modified polysiloxane and the pentaerythritol ester is (1-5): (0-3): (0-9).

[0027] In some embodiments of the present application, the mass ratio of the linear siloxane, the organic modified polysiloxane and the pentaerythritol ester is (0.6-1.5):1:(1-1.6), for example, 0.6:1:1, 0.8:1:1, 1:1:1, 1.2:1:1.2, 1.5:1:1.5, 1.5:1:1.6, etc. The lubricating oil composition obtained within this ratio range has the best high-temperature friction coefficient and wear amount on the ceramic / steel friction pair, showing a trend of consistency between low-temperature viscosity and high-temperature friction performance, thereby constructing a wide temperature range lubrication material system.

[0028] In some embodiments of the present application, the viscosity of the lubricating oil composition at 0°C is 0.15-0.55 Pa.s, such as 0.15 Pa.s, 0.20 Pa.s, 0.25 Pa.s, 0.30 Pa.s, 0.36 Pa.s, 0.38 Pa.s, 0.43 Pa.s, 0.45 Pa.s, 0.5 Pa.s, 0.52 Pa.s, 0.55 Pa.s, etc. The magnitude of low-temperature dynamic viscosity is a key factor affecting the low-temperature starting performance of engine equipment, devices, etc. The smaller the low-temperature viscosity, the easier it is to start. The greater the low-temperature viscosity, the greater the difficulty of the engine at low temperature operation, the longer the time required for the lubricating oil to reach the friction part, and short-term dry friction or semi-liquid friction will occur during friction, increasing wear. The viscosity of the lubricating oil described in the present application at 0°C is 0.15-0.55 Pa.s, that is, the viscosity at low temperature is relatively small, which solves the problem of poor rheological properties of pentaerythritol ester lubricating oil at low temperature.

[0029] An embodiment of the present application also provides a method for preparing the lubricating oil composition described in the first aspect of the present application, comprising the following steps: mixing linear siloxane, organic modified polysiloxane and pentaerythritol ester to obtain the lubricating oil composition. The mixed lubrication system obtained by the preparation method of the present application has the characteristics of simple mixing method, excellent uniformity, large mixing amount, etc., and is suitable for industrial production.

[0030] In some embodiments of the present application, the mixing temperature is 50-80°C, for example, 50°C, 60°C, 70°C, 80°C, etc., and the mixing time is 10-60min, for example, 10min, 20min, 30min, 40min, 50min, 60min, etc.

[0031] The technical solution of this application is further explained below in conjunction with specific implementation cases.

[0032] Example 1

[0033] A lubricating oil composition comprises 3g of ethyl silicone oil, 3g of chlorophenyl silicone oil and 3g of pentaerythritol ester.

[0034] The method for preparing the lubricating oil composition comprises the following steps:

[0035] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0036] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0037] Step 2: Compounding the mixed oil: Weigh 3g of ethyl silicone oil, 3g of chlorophenyl silicone oil and 3g of pentaerythritol ester in a mass ratio of 1:1:1 with an accuracy of 0.001g, mix them in the beaker after drying in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0038] Example 2

[0039] The only difference between Example 2 and Example 1 is that the lubricating oil composition described in Example 2 includes 3g of ethyl silicone oil, 2g of chlorophenyl silicone oil and 5g of pentaerythritol ester.

[0040] The specific steps include:

[0041] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0042] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0043] Step 2: Compounding the mixed oil: Weigh 3g of ethyl silicone oil, 2g of chlorophenyl silicone oil and 5g of pentaerythritol ester in a mass ratio of 3:2:5 with an accuracy of 0.001g, mix them in the beaker after drying in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0044] Example 3

[0045] The only difference between Example 3 and Example 1 is that the lubricating oil composition described in Example 3 includes 3g of ethyl silicone oil, 3g of chlorophenyl silicone oil and 4g of pentaerythritol ester.

[0046] The specific steps include:

[0047] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0048] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0049] Step 2: Compounding the mixed oil: Weigh 3g of ethyl silicone oil, 3g of chlorophenyl silicone oil and 4g of pentaerythritol ester in a mass ratio of 3:3:4 with an accuracy of 0.001g, mix them in the beaker after drying as described in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0050] Example 4

[0051] The only difference between Example 4 and Example 1 is that the lubricating oil composition described in Example 4 includes 2g of ethyl silicone oil, 3g of chlorophenyl silicone oil and 5g of pentaerythritol ester.

[0052] The specific steps include:

[0053] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0054] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0055] Step 2: Compounding the mixed oil: Weigh 2g of ethyl silicone oil, 3g of chlorophenyl silicone oil and 5g of pentaerythritol ester in a mass ratio of 2:3:5 with an accuracy of 0.001g, mix them in the beaker after drying in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0056] Example 5

[0057] The only difference between Example 5 and Example 1 is that the lubricating oil composition described in Example 5 includes 3g of benzyl silicone oil, 3g of chlorophenyl silicone oil and 3g of pentaerythritol ester.

[0058] The specific steps include:

[0059] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0060] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0061] Step 2: Compounding the mixed oil: Weigh 3 g of benzyl silicone oil, 4 g of chlorophenyl silicone oil and 3 g of pentaerythritol ester in a mass ratio of 3:3:3 with an accuracy of 0.001 g, mix them in the beaker after drying in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20 kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0062] Example 6

[0063] The only difference between Example 6 and Example 1 is that the lubricating oil composition described in Example 6 includes 3g of ethyl silicone oil, 3g of chlorophenyl siloxane and 3g of pentaerythritol ester.

[0064] The specific steps include:

[0065] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0066] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0067] Step 2: Compounding the mixed oil: Weigh 3g of ethyl silicone oil, 3g of chlorophenylsiloxane and 3g of pentaerythritol ester in a mass ratio of 3:3:3 with an accuracy of 0.001g, mix them in the beaker after drying in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0068] Example 7

[0069] The only difference between Example 7 and Example 1 is that the lubricating oil composition described in Example 7 includes 3g of ethyl silicone oil, 3g of hydroxyfluorosilicone oil and 3g of pentaerythritol ester.

[0070] The specific steps include:

[0071] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0072] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0073] Step 2: Compounding the mixed oil: Weigh 3g of ethyl silicone oil, 3g of hydroxyfluorosilicone oil and 3g of pentaerythritol ester in a mass ratio of 1:1:1 with an accuracy of 0.001g, mix them in the beaker after drying in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0074] Example 8

[0075] The only difference between Example 8 and Example 1 is that the lubricating oil composition described in Example 8 includes 3g of ethyl silicone oil, 3g of methyltetrachlorophenyl silicone oil and 3g of pentaerythritol ester.

[0076] The specific steps include:

[0077] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0078] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0079] Step 2: Compounding the mixed oil: Weigh 3 g of ethyl silicone oil, 3 g of methyl tetrachlorophenyl silicone oil and 3 g of pentaerythritol ester in a mass ratio of 1:1:1 with an accuracy of 0.001 g, mix them in the beaker after drying in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20 kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0080] Example 9

[0081] The only difference between Example 9 and Example 1 is that the lubricating oil composition described in Example 9 includes 3g of methyl silicone oil, 3g of ethyl silicone oil and 3g of pentaerythritol ester.

[0082] The specific steps include:

[0083] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0084] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0085] Step 2: Compounding the mixed oil: Weigh 3g of methyl silicone oil, 3g of ethyl silicone oil and 3g of pentaerythritol ester in a mass ratio of 1:1:1 with an accuracy of 0.001g, mix them in the beaker after drying in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0086] Example 10

[0087] The only difference between Example 10 and Example 1 is that the lubricating oil composition described in Example 10 includes 2g of ethyl silicone oil, 2g of chlorophenyl silicone oil and 6g of pentaerythritol ester.

[0088] The specific steps include:

[0089] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0090] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0091] Step 2: Compounding the mixed oil: Weigh 2g of ethyl silicone oil, 2g of chlorophenyl silicone oil and 6g of pentaerythritol ester in a mass ratio of 1:1:3 with an accuracy of 0.001g, mix them in the beaker after drying in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0092] Embodiment 11

[0093] The only difference between Example 11 and Example 1 is that the lubricating oil composition described in Example 11 includes 1g of ethyl silicone oil, 2g of chlorophenyl silicone oil and 7g of pentaerythritol ester.

[0094] The specific steps include:

[0095] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0096] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0097] Step 2: Compounding the mixed oil: Weigh 1 g of ethyl silicone oil, 2 g of chlorophenyl silicone oil and 7 g of pentaerythritol ester in a mass ratio of 1:2:7 with an accuracy of 0.001 g, mix them in the beaker after drying as described in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20 kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0098] Example 12

[0099] The only difference between Example 12 and Example 1 is that the lubricating oil composition described in Example 12 includes 1 g of ethyl silicone oil, 1 g of chlorophenyl silicone oil and 8 g of pentaerythritol ester.

[0100] The specific steps include:

[0101] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0102] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0103] Step 2: Compounding the mixed oil: Weigh 1g of ethyl silicone oil, 1g of chlorophenyl silicone oil and 8g of pentaerythritol ester in a mass ratio of 1:1:8 with an accuracy of 0.001g, mix them in the beaker after drying in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0104] Comparative Example 1

[0105] The only difference between Comparative Example 1 and Example 1 is that the lubricating oil composition described in Comparative Example 1 uses ethylene propylene copolymer (OCP) instead of ethyl silicone oil and chlorophenyl silicone oil.

[0106] The specific steps include:

[0107] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0108] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0109] Step 2: Compounding the mixed oil: Weigh 6 g of ethylene propylene copolymer (OCP) and 3 g of pentaerythritol ester at a mass ratio of 2:1 with an accuracy of 0.001 g, mix them in the beaker after drying as described in step 1, ultrasonically treat at a frequency of 20 kHz for 30 minutes, then place in an oil bath at 60°C for 30 minutes to fully dissolve, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0110] Comparative Example 2

[0111] The difference between Comparative Example 2 and Example 1 is that the lubricating oil composition described in Comparative Example 2 uses hydrogenated styrene-diene copolymer instead of chlorophenyl silicone oil.

[0112] The specific steps include:

[0113] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0114] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0115] Step 2: Compounding the mixed oil: Weigh 3g of ethyl silicone oil, 3g of hydrogenated styrene-diene copolymer and 3g of pentaerythritol ester in a mass ratio of 1:1:1 with an accuracy of 0.001g, mix them in the beaker after drying as described in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0116] Comparative Example 3

[0117] The difference between Comparative Example 3 and Example 1 is that the lubricating oil composition described in Comparative Example 3 uses polymethacrylate instead of ethyl silicone oil.

[0118] The specific steps include:

[0119] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0120] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0121] Step 2: Compounding the mixed oil: Weigh 3 g of polymethacrylate, 3 g of chlorophenyl silicone oil and 3 g of pentaerythritol ester in a mass ratio of 1:1:1 with an accuracy of 0.001 g, mix them in the beaker after drying as described in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20 kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0122] Comparative Example 4

[0123] The only difference between Comparative Example 4 and Example 1 is that the lubricating oil composition described in Comparative Example 4 does not contain raw material chlorophenyl silicone oil.

[0124] The specific steps include:

[0125] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0126] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0127] Step 2: Compounding the mixed oil: Weigh 3 g of ethyl silicone oil and 3 g of pentaerythritol ester in a mass ratio of 1:1 with an accuracy of 0.001 g, mix them in the beaker after drying in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20 kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0128] Comparative Example 5

[0129] The only difference between Comparative Example 5 and Example 1 is that the lubricating oil composition described in Comparative Example 5 does not contain raw materials chlorophenyl silicone oil and ethyl silicone oil.

[0130] Comparative Example 6

[0131] The only difference between Comparative Example 6 and Example 1 is that the lubricating oil composition described in Comparative Example 6 does not contain raw material ethyl silicone oil.

[0132] The specific steps include:

[0133] Step 1: Pretreatment: ultrasonically clean the beaker with deionized water, acetone, and anhydrous ethanol in sequence;

[0134] The specific operation is: first use deionized water for ultrasonic cleaning for 15 minutes, then use acetone for ultrasonic cleaning for 15 minutes, and then use anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then place the beaker in an oven at 60°C to dry for 12 hours for use.

[0135] Step 2: Compounding the mixed oil: Weigh 3 g of chlorophenyl silicone oil and 3 g of pentaerythritol ester in a mass ratio of 1:1 with an accuracy of 0.001 g, mix them in the beaker after drying in step 1, and place them in an oil bath at 60°C for 30 minutes at an ultrasonic frequency of 20 kHz for 30 minutes to fully dissolve them, and finally obtain a lubricating oil composition with excellent low-temperature viscosity.

[0136] Viscosity test of the lubricating oil composition described in Examples 1-12 and Comparative Examples 1-6 of the present application:

[0137] The test method is: using Anton Paar R301 to test the viscosity of the lubricating oil composition.

[0138] The specific operation is as follows: first, install the test rotor on the rheometer and set the shear rate to 0.001, 0.01, 0.02, 0.05, 0.01... until 1000s -1 There are 400 sampling points of shear rate in total, and the sampling time is 1s. Then the low-temperature rheological test is started. The test is carried out every 5℃, and the test temperature range is kept within ±1℃. When the shear rate suddenly increases or changes very little, the test is stopped. The test results are shown in Table 1.

[0139] Table 1

[0140] Viscosity at 0°C Low temperature viscosity Example 1 0.332Pa.s The low temperature viscosity at -50°C is 20.6 Pa.s Example 2 0.321Pa.s The low temperature viscosity at -40°C is 34.96 Pa.s Example 3 0.333Pa.s The low temperature viscosity at -50°C is 20.8 Pa.s Example 4 0.157Pa.s The low temperature viscosity at -45°C is 31.33 Pa.s Example 5 0.166Pa.s The low temperature viscosity at -50°C is 20.94 Pa.s Example 6 0.298Pa.s The low temperature viscosity at -55°C is 23.4 Pa.s Example 7 0.2166Pa.s The low temperature viscosity at -80°C is 10.14 Pa.s Example 8 0.53Pa.s The low temperature viscosity at -80°C is 13.4 Pa.s Example 9 0.51Pa.s The low temperature viscosity at -60°C is 19.49 Pa.s Example 10 0.451Pa.s The low temperature viscosity at -38°C is 34.17 Pa.s Embodiment 11 2.36Pa.s The low temperature viscosity at -18°C is 34.99 Pa.s Example 12 4.40Pa.s The low temperature viscosity at -15°C is 29.76 Pa.s Comparative Example 1 14.25Pa.s The low temperature viscosity at -10°C is 35.5 Pa.s Comparative Example 2 12.29Pa.s The low temperature viscosity at -5°C is 30.65 Pa.s Comparative Example 3 13.26Pa.s The low temperature viscosity at -5°C is 29.92 Pa.s Comparative Example 4 13.06Pa.s The low temperature viscosity at -5°C is 23.11 Pa.s Comparative Example 5 12.96Pa.s The low temperature viscosity at -5°C is 23.11 Pa. Comparative Example 6 13.56Pa.s The low temperature viscosity at -5°C is 22.62 Pa.s

[0141] It can be seen from Table 1 that organic modified polysiloxane can effectively improve the viscosity-temperature characteristics of high viscosity pentaerythritol ester and achieve good fluidity at a lower temperature.

[0142] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A lubricating oil composition, characterized in that: Includes linear siloxanes, organomodified polysiloxanes and pentaerythritol esters.

2. The lubricating oil composition according to claim 1, characterized in that: The linear polysiloxane includes one or more of methyl silicone oil, ethyl silicone oil, dimethyl silicone oil, benzyl silicone oil and diethyl silicone oil.

3. The lubricating oil composition according to claim 1, characterized in that: The linear polysiloxane is one or more of ethyl silicone oil, benzyl silicone oil and methyl silicone oil.

4. The lubricating oil composition according to claim 1, characterized in that: The organic modified polysiloxane includes one or more of chlorophenylsiloxane, methyltetrachlorophenyl silicone oil, hydroxyfluorosilicone oil and fluorochlorosilicone oil.

5. The lubricating oil composition according to claim 1, characterized in that: The organic modified polysiloxane is one or more of chlorophenylsiloxane, methyltetrachlorophenyl silicone oil and hydroxyfluorosilicone oil.

6. The lubricating oil composition according to any one of claims 1 to 5, characterized in that: The mass ratio of the linear siloxane, the organic modified polysiloxane and the pentaerythritol ester is (1-5):(0-3):(0-9).

7. The lubricating oil composition according to any one of claims 1 to 5, characterized in that: The mass ratio of the linear siloxane, the organic modified polysiloxane and the pentaerythritol ester is (0.6-1.5):1:(1-1.6).

8. The lubricating oil composition according to any one of claims 1 to 5, characterized in that: The viscosity of the lubricating oil composition at 0° C. is 0.15-0.55 Pa.s.

9. The method for preparing the lubricating oil composition according to any one of claims 1 to 8, characterized in that: The following steps are involved: The linear siloxane, the organic modified polysiloxane and the pentaerythritol ester are mixed to obtain the lubricating oil composition.

10. The method for preparing the lubricating oil composition according to claim 9, characterized in that: The mixing temperature is 50-80° C., and the mixing time is 10-60 min.